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Sample records for inns

  1. 15. LOOKING WEST TOWARD OLD FAITHFUL INN. THE INN'S NAMESAKE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. LOOKING WEST TOWARD OLD FAITHFUL INN. THE INN'S NAMESAKE, OLD FAITHFUL GEYSER IS AT LEFT. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  2. Obstacles to the universal application of INNs.

    PubMed

    2014-10-01

    Anomalies in the international non-proprietary name (INN) nomenclature show that the international harmonisation of nonproprietary drug names has not been achieved. When pharmaceutical companies request a new INN, they try to obtain an INN that serves their interests, and then use it for promotional or anticompetitive purposes. Drug regulatory agencies are not fulfilling their duty to protect existing INNs, particularly with regard to biosimilars (copies of biotechnology-derived drugs), giving rise in particular to anomalous names. The independence of the World Health Organization INN programme must be safeguarded to ensure that the universal terminology it is responsible for developing is applied worldwide. PMID:25964979

  3. How INNs are created. Making drug names safer by contributing to INN selection.

    PubMed

    2015-06-01

    The international nonproprietary names (INNs) of drugs proposed by the World Health Organization (WHO) are released for public consultation. These consultations provide an opportunity to identify any risks associated with INNs that could lead to confusion. Prescrire has submitted numerous comments since it began participating in the WHO's public consultations on proposed INNs in 2007. The WHO INN programme has occasionally taken our objections into account. It is easier to replace a proposed INN when a risk of confusion is identified early, before the drug is introduced to the market and the INN enters into use. Regular analysis of the INNs proposed by the WHO reveals some of the challenges of naming drugs and the influence exerted by pharmaceutical companies and the US drug nomenclature committee (USANC) in particular. The lack of an identifiable common stem in certain INNs, sometimes perceived as an obstacle to INN comprehensibility, is a consequence of the procedure for assigning INNs, because the INN programme wants to ensure that new common stems are not created prematurely. Critical analysis of proposed INNs during WHO public consultations offers an insight into the challenges involved in devising common stems. This analysis is useful for improving the quality and safety of INNs. PMID:26436175

  4. Colloids in the River Inn

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2015-04-01

    In the light of an increasing number of technical applications using nanoparticles and reports of adverse effects of engineered nanoparticles, research on the occurrence and stability of particles in all compartments has to be intensified. Colloids in river water represent the geologic setting, environmental conditions, and the anthropogenic use in its catchment. The river not only acts as a sink for nanoparticles but also as the source term due to exchange in the hyporheic zone and in bank filtration setups. The concentration, size distribution and elemental composition of particles in the River Inn were studied from the source in the Swiss Alps to the river mouth at Passau from 2008 to 2014. Samples were collected after each tributary from a sub-catchment and filtered on site using a new filtration device for gentle filtration. The elemental composition was determined after acid digestion with ICP/MS. SEM/EDX analysis provided morphological and elemental information for single particles. A complementary chemical analysis of the river water was performed to assess the geochemical stability of individual particles. As presented at EGU 2014, particles in the upper, rural parts mainly reveal changes in the geological setting of the tributary catchments. Not unexpectedly, particles originating from crystalline rocks, were more stable than particles originating from calcareous rocks. Anthropogenic and industrial influences increase in the lower parts. This went together with a change of the size distribution, an increase of the number of organic particles, and a decrease of the microfauna. Interestingly, specific leisure activities in a sub-catchment, like extensive downhill skiing, manifest itself in the particle composition. This general setting was validated in last year's sampling campaigns. An interesting change in on site parameters and hydrochemical composition was seen during all sampling campaigns at an inflow from the valley Kaunertal, Austria. Therefore

  5. Konocti Harbon Inn, Kelseyville, California

    SciTech Connect

    Not Available

    1982-04-01

    Konocti Harbor is a large resort complex, located on the shore of Clear Lake, in Kelseyville, California. A number of buildings on the property, including a 25,000 square foot lodge, 101 motel units and 48 apartment units are heated by the large water-to-water heat pumps, using water from the lake as a heat source. Due to low winter occupancy rates, these machines are run at very low capacity. In addition, a number of buildings are operated on electric resistance and propane backup boilers. This mode of operation results in a relatively high cost compared to the actual heating requirements. Since these systems were originally designed for low temperature water (125/sup 0/F supply 10/sup 0/..delta..t), a low temperature geothermal resource could potentially displace some of the conventional fuel currently used. The potential for geothermal use at the Konocti Harbor Inn is explored.

  6. Colloids in the River Inn

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Baumann, Thomas

    2014-05-01

    In the light of an increasing number of technical applications using nanoparticles and reports of adverse effects of engineered nanoparticles, research on the occurrence and stability of particles in all compartments has to be intensified. Colloids in river water represent the geologic setting, environmental conditions, and the anthropogenic use in its catchment. The river not only acts as a sink for nanoparticles but also as the source term due to exchange in the hyporheic zone and in bank filtration setups. The concentration, size distribution and elemental composition of particles in the River Inn were studied from the source in the Swiss Alps to the river mouth at Passau. Samples were collected after each tributary from a sub-catchment and filtered on-site. The elemental composition was determined after acid digestion with ICP/MS. SEM/EDX analyses provided morphological and elemental information for single particles. A complementary chemical analysis of the river water was performed to assess the geochemical stability of indvidual particles. Particles in the upper, rural parts mainly reveal changes in the geological setting of the tributary catchments. Not unexpectedly, particles originating from crystalline rocks, were more stable than particles originating from calcareous rocks. Anthropogenic and industrial influences increase in the lower parts. This went together with a change of the size distribution, an increase of the number of organic particles, and a decrease of the microfauna. Interestingly, specific leisure activities in a sub-catchment, like extensive downhill skiing, manifest itself in the particle composition.

  7. Growth of InN hexagonal microdisks

    NASA Astrophysics Data System (ADS)

    Yang, Chen-Chi; Lo, Ikai; Hu, Chia-Hsuan; Huang, Hui-Chun; Chou, Mitch M. C.

    2016-08-01

    InN hexagonal thin wurtzite disks were grown on γ-LiAlO2 by plasma-assisted molecular-beam epitaxy at low temperature (470oC). The ( 000 1 ¯ ) InN thin disk was established with the capture of N atoms by the β ¯ -dangling bonds of most-outside In atoms, and then the lateral over-growth of the In atoms were caught by the β ¯ -dangling bonds of the N atoms. From the analyses of high-resolution transmission electron microscopy, the lateral over-grown width was extended to three unit cells at [ 1 1 ¯ 00 ]InN direction for a unit step-layer, resulting in an oblique surface with 73o off c-axis.

  8. 16. LOOKING WEST AT OLD FAITHFUL INN, MOST OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. LOOKING WEST AT OLD FAITHFUL INN, MOST OF THE EAST WING IS VISIBLE TO THE LEFT. THE EAST WING ADDITION WAS BUILT BY THE INN'S ORIGINAL ARCHITECT, ROBERT C. REAMER IN 1913-14. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  9. 3. View to southeast from hillside behind Inn. Roof of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View to southeast from hillside behind Inn. Roof of 'Big Sur Inn' Building (HABS-CA-2611-A) at lower center, State Highway 1 bridge across Castro Creek Canyon at upper center. - Deetjen's Big Sur Inn, East Side of State Highway 1, Big Sur, Monterey County, CA

  10. Taming transport in InN

    SciTech Connect

    Ager III, Joel W.; Miller, Nate R.

    2011-05-29

    The large electron affinity of InN, close to 6 eV and the largest of any III-V semiconductor, creates a strong driving force for native donor formation, both in the bulk and at surfaces and interfaces. Moreover, all InN surfaces, regardless of crystal orientation or doping, have been observed to have a surface accumulation layer of electrons, which interferes with standard electrical measurements. For these reasons, until recently, it was uncertain whether or not compensation by donor defects would prevent “real” p-type activity (i.e. existence of sufficiently shallow acceptors and mobile holes). A coordinated experimental approach using a combination of electrical (Hall effect) and electrothermal (Seebeck coefficient) measurements will be described that allows definitive evaluation of carrier transport in InN. In Mg-doped InN films, the sensitivity of thermopower to bulk hole conduction, combined with modeling of the parallel conducting layers (surface/bulk/interface), enables quantitative measurement of the free hole concentration and mobility. In undoped (n-type) material, combined Hall and thermopower measurements, along with a considering of the scattering mechanisms, leads to a quantitative understanding of the crucial role of charged line defects in limiting electron transport.

  11. Mg doped InN and confirmation of free holes in InN

    SciTech Connect

    Wang, K.; Yamaguchi, T.; Miller, N.; Mayer, M. A.; Haller, E. E.; Iwamoto, R.; Araki, T.; Nanishi, Y.; Yu, K. M.; Walukiewicz, W.; Ager, J. W. III

    2011-01-24

    We report a systematic investigation on Mg doped InN epilayers grown by radio-frequency plasma-assisted molecular beam epitaxy. Electrolyte capacitance voltage (ECV) combined with thermopower measurements find p-type conduction over an Mg concentration range. For InN:Mg in this p-type 'window' the Seebeck coefficients dramatically change their signs from negative to positive when the thickness of undoped InN interlayer decreases to zero. This notable sign change of Seebeck coefficient explains the previous inconsistency between ECV and thermopower results and confirms the existence of mobile holes in the InN:Mg. Taking into account the undoped InN interlayer, the hole density and mobility are extracted.

  12. 1. View north from across State Highway 1 toward Inn. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View north from across State Highway 1 toward Inn. 'Big Sur Inn' Building (HABS-CA-2611-A) visible at left, 'Hayloft' Building (HABS-CA-2611-B at right center, and 'Antique' Building (HABS-CA-2611-C) and 'Champagne' Building (HABS-CA-2611-D) out of sight behind trees at right. - Deetjen's Big Sur Inn, East Side of State Highway 1, Big Sur, Monterey County, CA

  13. Investigation of gas sensing properties of InN nanoparticles

    SciTech Connect

    Madapu, Kishore K. E-mail: dhara@igcar.gov.in; Prasad, A. K.; Tyagi, A. K.; Dhara, S. E-mail: dhara@igcar.gov.in

    2015-06-24

    InN nanoparticles were grown by chemical vapor deposition technique using In{sub 2}O{sub 3} as precursor material. Raman spectroscopic studies show the presence of the wurtzite phase of as-grown InN. Size of the nanoparticles were in range from quantum dot (<8 nm) to larger sized particles (100 nm). We studied the gas sensing properties of InN nanoparticles with CH{sub 4} gas. Sensors substrates were fabricated with interdigitated Au electrodes. InN nanoparticles show high response towards CH{sub 4} with minimum detectable concentration of 50 ppm at 200 °C.

  14. 21. REAR OF OLD FAITHFUL INN, LOOKING NORTH. SEMICIRCULAR SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. REAR OF OLD FAITHFUL INN, LOOKING NORTH. SEMI-CIRCULAR SIDE DINING ROOM, NOW CALLED THE BEAR PIT WAS ADDED IN 1927. (TAKEN FROM CHERRY-PICKER) - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  15. Solar Hot Water for Motor Inn--Texas City, Texas

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Final report describes solar domestic-hot-water heater installation at LaQuinta Motor Inn, Texas City, Texas which furnished 63% of total hot-water load of new 98-unit inn. Report presents a description of system, drawings and photographs of collectors, operations and maintenance instructions, manufacturers' specifications for pumps, and an engineer's report on performance.

  16. The INNs and outs of antibody nonproprietary names

    PubMed Central

    Jones, Tim D.; Carter, Paul J.; Plückthun, Andreas; Vásquez, Max; Holgate, Robert G.E.; Hötzel, Isidro; Popplewell, Andrew G.; Parren, Paul W.H.I.; Enzelberger, Markus; Rademaker, Hendrik J.; Clark, Michael R.; Lowe, David C.; Dahiyat, Bassil I.; Smith, Victoria; Lambert, John M.; Wu, Herren; Reilly, Mary; Haurum, John S.; Dübel, Stefan; Huston, James S.; Schirrmann, Thomas; Janssen, Richard A.J.; Steegmaier, Martin; Gross, Jane A.; Bradbury, Andrew R.M.; Burton, Dennis R.; Dimitrov, Dimiter S.; Chester, Kerry A.; Glennie, Martin J.; Davies, Julian; Walker, Adam; Martin, Steve; McCafferty, John; Baker, Matthew P.

    2016-01-01

    An important step in drug development is the assignment of an International Nonproprietary Name (INN) by the World Health Organization (WHO) that provides healthcare professionals with a unique and universally available designated name to identify each pharmaceutical substance. Monoclonal antibody INNs comprise a –mab suffix preceded by a substem indicating the antibody type, e.g., chimeric (-xi-), humanized (-zu-), or human (-u-). The WHO publishes INN definitions that specify how new monoclonal antibody therapeutics are categorized and adapts the definitions to new technologies. However, rapid progress in antibody technologies has blurred the boundaries between existing antibody categories and created a burgeoning array of new antibody formats. Thus, revising the INN system for antibodies is akin to aiming for a rapidly moving target. The WHO recently revised INN definitions for antibodies now to be based on amino acid sequence identity. These new definitions, however, are critically flawed as they are ambiguous and go against decades of scientific literature. A key concern is the imposition of an arbitrary threshold for identity against human germline antibody variable region sequences. This leads to inconsistent classification of somatically mutated human antibodies, humanized antibodies as well as antibodies derived from semi-synthetic/synthetic libraries and transgenic animals. Such sequence-based classification implies clear functional distinction between categories (e.g., immunogenicity). However, there is no scientific evidence to support this. Dialog between the WHO INN Expert Group and key stakeholders is needed to develop a new INN system for antibodies and to avoid confusion and miscommunication between researchers and clinicians prescribing antibodies. PMID:26716992

  17. Nanogenerators based on vertically aligned InN nanowires.

    PubMed

    Liu, Guocheng; Zhao, Songrui; Henderson, Robert D E; Leonenko, Zoya; Abdel-Rahman, Eihab; Mi, Zetian; Ban, Dayan

    2016-01-28

    Piezoelectric nanogenerators (NGs) based on vertically aligned InN nanowires (NWs) are fabricated, characterized, and evaluated. In these NGs, arrays of p-type and intrinsic InN NWs prepared by plasma-assisted molecular beam epitaxy (MBE) demonstrate similar piezoelectric properties. The p-type NGs show 160% more output current and 70% more output power product than the intrinsic NGs. The features driving performance enhancement are reduced electrostatic losses due to better NW array morphology, improved electromechanical energy conversion efficiency due to smaller NW diameters, and the higher impedance of intrinsic NGs due to elevated NW surface charge levels. These findings highlight the potential of InN based NGs as a power source for self-powered systems and the importance of NW morphology and surface state in overall NG performance. PMID:26700694

  18. InN Quantum Dot Based Infra-Red Photodetectors.

    PubMed

    Shetty, Arjun; Kumar, Mahesh; Roull, Basanta; Vinoy, K J; Krupanidhj, S B

    2016-01-01

    Self-assembled InN quantum dots (QDs) were grown on Si(111) substrate using plasma assisted molecular beam epitaxy (PA-MBE). Single-crystalline wurtzite structure of InN QDs was confirmed by X-ray diffraction. The dot densities were varied by varying the indium flux. Variation of dot density was confirmed by FESEM images. Interdigitated electrodes were fabricated using standard lithog- raphy steps to form metal-semiconductor-metal (MSM) photodetector devices. The devices show strong infrared response. It was found that the samples with higher density of InN QDs showed lower dark current and higher photo current. An explanation was provided for the observations and the experimental results were validated using Silvaco Atlas device simulator. PMID:27398511

  19. The Children's Inn at NIH turns 25 | NIH MedlinePlus the Magazine

    MedlinePlus

    ... a supportive environment, including therapeutic, educational, and recreational programming. Dalvin plays board games at The Inn's Woodmont ... Clinical Center. The Inn has a playroom, kids' computer room, bistro, game room, learning center, business center, ...

  20. The Children's Inn at NIH Anniversary Key Messages | NIH MedlinePlus the Magazine

    MedlinePlus

    ... 37 sleeping rooms. The Inn opened a major expansion in May 2004, adding a new wing with ... Merck donated another $3.7 million for the expansion project. fast facts 1 The Children's Inn, located ...

  1. Optical properties of InN related to surface plasmons

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Leymarie, J.; Jmerik, V. N.; Toropov, A. A.; Vasson, A.; Amano, H.; Schaff, W. J.; Monemar, B.; Ivanov, S. V.

    2005-11-01

    We report on the complex nature of infrared luminescence and absorption in InN films, which cannot be entirely explained by the concept of a conventional narrow-gap semiconductor. In particular, it concerns the detection of peaks near absorption edges by both thermally detected optical absorption and photoluminescence excitation spectroscopy and the observation of extraordinarily strong resonant enhancement of emission. To describe the experimental data a model is proposed, which takes into account surface plasmons in metal-like inclusions, modifying the optical properties of InN.

  2. Hot Water for Motor Inn--Garland, Texas

    NASA Technical Reports Server (NTRS)

    1982-01-01

    35-page report describes solar collector system and its operation and presents projected system performance. Details calibration and maintenance procedures and lists and describes equipment that makes up system. System provides hot water for laundry, for showers and sinks in inn rooms.

  3. Solar Hot Water for a Motor Inn -- Las Vegas, Nevada

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar hot-water installation at motor inn in Las Vegas, Nevada is described in report containing descriptions of design, philosophy, operation of system and problems and solutions. Provides drawings of solar roof plan, operator's instructions, manufacturers' brochures and copy of acceptance report.

  4. Temperature switching of cavity modes in InN microcrystals

    SciTech Connect

    Kazanov, D. R. Kaibyshev, V. H.; Davydov, V. Yu.; Smirnov, A. N.; Jmerik, V. N.; Kuznetsova, N. V.; Kopiev, P. S.; Ivanov, S. V.; Shubina, T. V.

    2015-11-15

    InN optical cavities supporting low-order whispering-gallery modes up to room temperature are formed by molecular-beam epitaxy on patterned substrates. The observed switching of the mode type with increasing temperature is explained in terms of changes in the optical parameters due to a shift of the absorption edge and modification of its shape. Modeling taking into account a variation in the refractive index reproduces the typical distributions of the electromagnetic-field intensity in the cavities.

  5. Self-compensation in highly n-type InN

    SciTech Connect

    Rauch, C.; Tuomisto, F.; King, P. D. C.; Veal, T. D.; Lu, H.; Schaff, W. J.

    2012-07-02

    Acceptor-type defects in highly n-type InN are probed using positron annihilation spectroscopy. Results are compared to Hall effect measurements and calculated electron mobilities. Based on this, self-compensation in n-type InN is studied, and the microscopic origin of compensating and scattering centers in irradiated and Si-doped InN is discussed. We find significant compensation through negatively charged indium vacancy complexes as well as additional acceptor-type defects with no or small effective open volume, which act as scattering centers in highly n-type InN samples.

  6. Convergence of valence bands for high thermoelectric performance for p-type InN

    NASA Astrophysics Data System (ADS)

    Li, Hai-Zhu; Li, Ruo-Ping; Liu, Jun-Hui; Huang, Ming-Ju

    2015-12-01

    Band engineering to converge the bands to achieve high valley degeneracy is one of effective approaches for designing ideal thermoelectric materials. Convergence of many valleys in the valence band may lead to a high Seebeck coefficient, and induce promising thermoelectric performance of p-type InN. In the current work, we have systematically investigated the electronic structure and thermoelectric performance of wurtzite InN by using the density functional theory combined with semiclassical Boltzmann transport theory. Form the results, it can be found that intrinsic InN has a large Seebeck coefficient (254 μV/K) and the largest value of ZeT is 0.77. The transport properties of p-type InN are better than that of n-type one at the optimum carrier concentration, which mainly due to the large Seebeck coefficient for p-type InN, although the electrical conductivity of n-type InN is larger than that of p-type one. We found that the larger Seebeck coefficient for p-type InN may originate from the large valley degeneracy in the valence band. Moreover, the low minimum lattice thermal conductivity for InN is one key factor to become a good thermoelectric material. Therefore, p-type InN could be a potential material for further applications in the thermoelectric area.

  7. The Little Inn at the Crossroads: A Spiritual Approach to the Design of a Leadership Course.

    ERIC Educational Resources Information Center

    Bento, Regina F.

    2000-01-01

    A course on spiritual dimensions of leadership was designed using the metaphor of an inn at a crossroads. The inn included a virtual library of Web-based texts and studio space for creativity and self-expression. Seven workshops explored the following themes: language of leadership and change, personal leadership qualities, vision and mission,…

  8. The Children's Inn at NIH - Three Stories | NIH MedlinePlus the Magazine

    MedlinePlus

    ... and her family have come to consider The Children's Inn their "home away from home." "Staying at The Inn helps ... I love being a school nurse and helping children be successful in the school ... Dr. Brian Brooks uses a puppet during a young patient's eye exam ...

  9. Geothermal heating facilities for Frontier Inn, Susanville, California

    NASA Astrophysics Data System (ADS)

    1982-03-01

    A 38 unit motel composed of six major sections (coffee shop, A frame units, apartments, back units, two story units and office) was built over a number of years and exhibits widely varying types of construction. Space heating is provided by primarily electric resistance equipment with some propane use. Domestic hot water is provided primarily by propane with some electric resistance. The coffee shop uses fuel oil for both space and domestic hot water heating. A geothermal district heating system is being installed. Although the motel site is not located in the area of construction activity, it is expected that the pipeline will be extended. The potential of retrofitting the existing heating facilities at the inn to geothermal is studied.

  10. Photoluminescence properties of Mg-doped InN nanowires

    SciTech Connect

    Zhao, Songrui; Liu, Xuedong; Mi, Zetian

    2013-11-11

    In this work, photoluminescence (PL) properties of nearly defect-free Mg-doped InN nanowires were investigated in detail. The low-doped sample exhibits two PL emission peaks up to 152 K, which can be ascribed to the band-to-band recombination and the Mg-acceptor energy level related recombination, respectively. For the high-doped sample, the Mg-acceptor energy level related transition dominates. Detailed power dependent PL studies further indicate that the Mg-acceptor energy level related PL emission is due to the donor-acceptor pair recombination process, which subsequently evolves into the free-to-acceptor recombination with increasing temperature.

  11. Highly efficient potentiometric glucose biosensor based on functionalized InN quantum dots

    NASA Astrophysics Data System (ADS)

    Alvi, N. H.; Soto Rodriguez, P. E. D.; Gómez, V. J.; Kumar, Praveen; Amin, G.; Nur, O.; Willander, M.; Nötzel, R.

    2012-10-01

    We present a fast, highly sensitive, and efficient potentiometric glucose biosensor based on functionalized InN quantum-dots (QDs). The InN QDs are grown by molecular beam epitaxy. The InN QDs are bio-chemically functionalized through physical adsorption of glucose oxidase (GOD). GOD enzyme-coated InN QDs based biosensor exhibits excellent linear glucose concentration dependent electrochemical response against an Ag/AgCl reference electrode over a wide logarithmic glucose concentration range (1 × 10-5 M to 1 × 10-2 M) with a high sensitivity of 80 mV/decade. It exhibits a fast response time of less than 2 s with good stability and reusability and shows negligible response to common interferents such as ascorbic acid and uric acid. The fabricated biosensor has full potential to be an attractive candidate for blood sugar concentration detection in clinical diagnoses.

  12. Highly Sensitive and Fast Anion-Selective InN Quantum Dot Electrochemical Sensors

    NASA Astrophysics Data System (ADS)

    Hassan Alvi, Naveed ul; Rodriguez, Paul E. D. Soto; Gómez, Victor J.; Kumar, Praveen; Willander, Magnus; Nötzel, Richard

    2013-11-01

    Epitaxial InN quantum dots (QDs) are demonstrated as ion-selective electrode for potentiometric anion concentration measurements. The sensor reveals high sensitivity above 90 mV/decade for the detection of chlorine and hydroxyl ions in sodium chloride (NaCl), calcium chloride (CaCl2), and sodium hydroxide (NaOH) solutions. The response time is less than two seconds after which the signal is very stable and repeatable. The sensitivity for the InN QDs is about two times that for a reference InN thin film and the response time is about five times shorter. In pH buffer solutions the sensor reveals no clear response to cations. A model is presented for the high sensitivity, fast response, and ion selectivity based on the unique electronic properties of the InN surface together with the zero-dimensional nature of the QDs.

  13. InN Based Water Condensation Sensors on Glass and Flexible Plastic Substrates

    PubMed Central

    Dumitru, Viorel; Costea, Stefan; Brezeanu, Mihai; Stan, George E.; Besleaga, Cristina; Galca, Aurelian C.; Ionescu, Gabriela; Ionescu, Octavian

    2013-01-01

    In this paper, we report the realization and characterization of a condensation sensor based on indium nitride (InN) layers deposited by magnetron sputtering on glass and flexible plastic substrates, having fast response and using potentially low cost fabrication technology. The InN devices work as open gate thin film sensitive transistors. Condensed water droplets, formed on the open gate region of the sensors, deplete the electron accumulation layer on the surface of InN film, thus decreasing the current of the sensor. The current increases back to its initial value when water droplets evaporate from the exposed InN film surface. The response time is as low as 2 s.

  14. Two-dimensional electron gas in monolayer InN quantum wells

    SciTech Connect

    Pan, W. E-mail: e.dimakis@hzdr.de; Wang, G. T.; Dimakis, E. E-mail: e.dimakis@hzdr.de; Moustakas, T. D.; Tsui, D. C.

    2014-11-24

    We report in this letter experimental results that confirm the two-dimensional nature of the electron systems in a superlattice structure of 40 InN quantum wells consisting of one monolayer of InN embedded between 10 nm GaN barriers. The electron density and mobility of the two-dimensional electron system (2DES) in these InN quantum wells are 5 × 10{sup 15 }cm{sup −2} (or 1.25 × 10{sup 14 }cm{sup −2} per InN quantum well, assuming all the quantum wells are connected by diffused indium contacts) and 420 cm{sup 2}/Vs, respectively. Moreover, the diagonal resistance of the 2DES shows virtually no temperature dependence in a wide temperature range, indicating the topological nature of the 2DES.

  15. Polarity and microstructure in InN thin layers grown by MOVPE

    NASA Astrophysics Data System (ADS)

    Kuwano, N.; Nakahara, Y.; Amano, H.

    2006-06-01

    Microstructures in InN grown on sapphire (0001) and yttria-stabilized zirconia (YSZ) (111) by metal-organic vapor phase epitaxy (MOVPE) were analyzed by means of transmission electron microscopy (TEM) in order to clarify the growth process. Special attention was paid to the selectivity of the crystal polarity of InN. The InN thin films grown on sapphire after nitridation has a flat surface while those grown on YSZ has hillocks on the surface. The crystal polarity was determined by comparing the experimentally observed intensity distribution in convergent beam electron diffraction (CBED) disks with those simulated by the Broch-wave method. It was found that the InN grown on the sapphire has a nitrogen-polarity and the one on YSZ has a mixture of In- and N-polarities. The effect of surface-nitridation of sapphire on the growth process is also discussed

  16. Accommodation mechanism of InN nanocolumns grown on Si(111) substrates by molecular beam epitaxy

    SciTech Connect

    Grandal, J.; Sanchez-Garcia, M. A.; Calleja, E.; Luna, E.; Trampert, A.

    2007-07-09

    High quality InN nanocolumns have been grown by molecular beam epitaxy on bare and AlN-buffered Si(111) substrates. The accommodation mechanism of the InN nanocolumns to the substrate was studied by transmission electron microscopy. Samples grown on AlN-buffered Si(111) show abrupt interfaces between the nanocolumns and the buffer layer, where an array of periodically spaced misfit dislocations develops. Samples grown on bare Si(111) exhibit a thin Si{sub x}N{sub y} at the InN nanocolumn/substrate interface because of Si nitridation. The Si{sub x}N{sub y} thickness and roughness may affect the nanocolumn relative alignment to the substrate. In all cases, InN nanocolumns grow strain- and defect-free.

  17. Mie Resonant Absorption and Infrared Emission in InN Related to Metallic Indium Clusters

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Ivanov, S. V.; Jmerik, V. N.; Solnyshkov, D. D.; Kop'ev, P. S.; Vasson, A.; Leymarie, J.; Kavokin, A.; Amano, H.; Kamiyama, S.; Iwaya, M.; Akasaki, I.; Lu, H.; Schaff, W. J.; Kasic, A.; Monemar, B.

    2005-06-01

    We demonstrate that resonant optical losses related to metallic In clusters can significantly modify absorption spectra of InN with any optical gap. Thermally detected absorption spectra with a pronounced Mie resonance are successfully simulated using a dielectric function of InN corresponding to the 1.2-1.4 eV optical gap. The resonance is observed in spectra of conventional absorption at low temperatures being smoothed out at room temperature.

  18. Growth of hexagonal and cubic InN nanowires using MOCVD with different growth temperatures

    NASA Astrophysics Data System (ADS)

    Yun, Seok-Hyo; Ra, Yong-Ho; Lee, Young-Min; Song, Ki-Young; Cha, Jun-Ho; Lim, Hong-Chul; Kim, Dong-Wook; Suthan Kissinger, N. J.; Lee, Cheul-Ro

    2010-07-01

    We have performed a detailed investigation of the metal-organic chemical vapor deposition (MOCVD) growth and characterization of InN nanowires formed on Si(1 1 1) substrates under nitrogen rich conditions. The growth of InN nanowires has been demonstrated by using an ion beam sputtered (˜10 nm) Au seeding layer prior to the initiation of growth. We tried to vary the growth temperature and pressure in order to obtain an optimum growth condition for InN nanowires. The InN nanowires were grown on the Au+In solid solution droplets caused by annealing in a nitrogen ambient at 700 °C. By applying this technique, we have achieved the formation of InN nanowires that are relatively free of dislocations and stacking faults. Scanning electron microscopy (SEM) showed wires with diameters of 90-200 nm and lengths varying between 3 and 5 μm. Hexagonal and cubic structure is verified by high resolution X-ray diffraction (HR-XRD) spectrum. Raman measurements show that these wurtzite InN nanowires have sharp peaks E2 (high) at 491 cm -1 and A 1 (LO) at 591 cm -1.

  19. Characterization of InN nanoparticles prepared by laser as photodetector

    NASA Astrophysics Data System (ADS)

    Khashan, Khawla S.; Abbas, Sarah F.

    2016-05-01

    Indium nitride (InN) nanoparticles (NPs) are a potentially important material for optoelectronic and high speed electronic devices. Using 1064 nm Nd:YAG laser, InN NPs suspension has been prepared by laser ablation of indium target submerged under ammonium hydroxide. FTIR determined the presence of In=N at 1114.8 cm‑1 symmetric stretching mode, and In-N bending vibration mode appears at 445.5 cm‑1. X-ray diffraction (XRD) observed the peaks (101), (110), and (220) as a reflection formation cubic InN, with an average size of 2 nm. Scanning electron microscope (SEM) image shows that the NPs have a spherical shape with particle size in the range 2-20 nm. The transmission spectra of InN NPs suspension have the maximum optical transmission edge at 1378 nm with the band gap energy of 1.2 eV. The current-voltage characteristics of InN/Si heterojunction have a good rectifying property with a spectral responsivity of about 0.797 A/W at 750 nm wavelength.

  20. Growth of very large InN microcrystals by molecular beam epitaxy using epitaxial lateral overgrowth

    SciTech Connect

    Kamimura, J.; Kishino, K.; Kikuchi, A.

    2015-02-28

    Very thick InN (∼40 μm) was grown by molecular beam epitaxy using the epitaxial lateral overgrowth (ELO) technique. In some regions, the ELO of InN was observed as expected, indicating an important step toward fabricating quasi-bulk InN substrates. Interestingly, most parts of the sample consist of large flat-topped microcrystals and well-faceted microstructures. This is likely due to local growth condition variations during ELO, which is supported by an experiment where ELO of InN was performed on a substrate with various stripe mask patterns. TEM characterization of a flat top InN microcrystal revealed few stacking faults and only related threading dislocations. Defect-free small faceted microcrystals were also observed. The thick InN crystals show a narrow photoluminescence spectrum with a peak at 0.679 eV and linewidth of 16.8 meV at 4 K.

  1. First-principles study of optical properties of InN nanosheet

    NASA Astrophysics Data System (ADS)

    Sarmazdeh, Masoud Majidiyan; Mendi, Roohallah Taghavi; Zelati, Amir; Boochani, Arash; Nofeli, Fariba

    2016-05-01

    Based on density functional theory (DFT), some optical properties of InN nanosheet, such as dielectric function, energy loss function, refractive index, reflectivity and absorption coefficient, have been calculated using the modified Becke-Johnson (mBJ) exchange-correlation potential and full potential-linearized augmented plane waves (FP-LAPW) method. The study of dielectric function show that optical properties of InN nanosheet are anisotropic and important energy range in the optical process is between low energies to 20 eV. The results indicate the plasmon energy of InN nanosheet occurs in the lower energy than bulk InN and in addition the plasmon energy in the in-plane direction is different from that perpendicular to the in-plane direction. The obtained optical gaps are 1.2 eV and 3.6 eV in perpendicular and parallel to c-axis, respectively. Study of refractive index and optical reflectivity shows that the superluminal phenomena occur in the several energy ranges for the InN nanosheet and this nanosheet has high transparency in a wide energy range. The results propose that the InN nanosheet is a good candidate for the optical communications applications, optoelectronics devices and transparent coatings.

  2. Investigation of the 1987 Indianapolis Airport Ramada Inn incident.

    PubMed

    Clark, M A; Hawley, D A; McClain, J L; Pless, J E; Marlin, D C; Standish, S M

    1994-05-01

    On October 20, 1987, a military reserve aircraft lost power during a transcontinental flight and attempted an emergency landing at The Indianapolis International Airport. The pilot ejected and the disabled and pilotless aircraft struck a bank building. It then skidded across the street and entered the lobby of The Airport Ramada Inn where it exploded. This incident was unusual in that the fatal injuries occurred in individuals on the ground and not in the occupant of the aircraft. Seven people were killed in the lobby area and two were trapped in a laundry where they died of smoke inhalation. A tenth person died of burns ten days later. Minor injuries were reported among four hotel guests, two firefighters and the Air Force pilot. A multiagency mass disaster-plan had been formulated and rehearsed in preparation for the Panamerican Games, which had been held in Indianapolis in August 1987. A number of volunteers arrived before a security perimeter was established. They began an undocumented removal of the bodies from the scene and were about to remove valuables for "safekeeping" when stopped by coroners' office personnel. Fatalities resulted from smoke inhalation, burns or a combination. Bodies were identified by a combination of dental records, personal effects and visual means within 24 hours. The problems encountered in managing this disaster scene will also be compared with previously reported incidents. PMID:8006612

  3. Heteroepitaxial growth of InN on GaN intermediate layer by PA-MOMBE

    NASA Astrophysics Data System (ADS)

    Lai, Fang-I.; Kuo, Shou-Yi; Chen, Wei-Chun; Lin, Woei-Tyng; Wang, Wei-Lin; Chang, Li; Hsiao, Chien-Nan; Chiang, Chung-Hao

    2011-07-01

    In this paper, high-quality wurtzite indium nitride was epi-grown on sapphire substrates by plasma-assisted metal-organic molecule beam epitaxy system (PA-MOMBE). Structural and electrical properties of the InN films were significantly improved by employing a GaN buffer layer. In addition, high-resolution X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM), Hall Effect, Raman and photoluminescence spectroscopy were carried out to characterize the effect of the growth temperature on structural and optoelectronic properties. It was found that highly c-axis oriented InN epilayer can be obtained by optimizing growth conditions. TEM images reveal that the epitaxially grown InN/GaN interface is sharp, and the spacing of the InN(0 0 0 2) lattice plane is about 0.57 nm. Raman spectra also show a sharp peak at 491 cm -1 attributed to the E 2(high) mode of wurtzite InN. These results indicate that the improvement of InN material quality can be achieved using heteroepitaxy on GaN/sapphire templates.

  4. Optical and structural properties of InN grown by HPCVD

    NASA Astrophysics Data System (ADS)

    Buegler, M.; Alevli, M.; Atalay, R.; Durkaya, G.; Senevirathna, I.; Jamil, M.; Ferguson, I.; Dietz, N.

    2009-08-01

    The optical and structural properties of InN layers grown by 'High Pressure Chemical Vapor Deposition' (HPCVD) using a pulsed precursor approach have been studied. The study focuses on the effect of ammonia precursor exposure time and magnitude on the InN layer quality. The samples have been analyzed by X-ray diffraction, Raman scattering, infra red reflectance spectroscopy and photoluminescence spectroscopy. Raman measurements and X-ray diffraction showed the grown layers to be single phase InN of high crystalline quality. The E2(high) Raman mode showed FWHM's as small as 9.2 cm-1. The FWHM's of the InN(0002) X-ray Bragg reflex in the 2Θ-Ω- scans were around 350 arcsec, with rocking curve values as low as 1152 arcsec Photoluminescence features have been observed down to 0.7 eV, where the low energy cutoff might be due to the detector limitation. The analysis of the IR reflectance spectra shows that the free carrier concentrations are as low as as 3.3•1018 cm-3 for InN layers grown on sapphire substrates.

  5. Large area InN terahertz emitters based on the lateral photo-Dember effect

    SciTech Connect

    Wallauer, Jan Grumber, Christian; Walther, Markus; Polyakov, Vladimir; Iannucci, Robert; Cimalla, Volker; Ambacher, Oliver

    2015-09-14

    Large area terahertz emitters based on the lateral photo-Dember effect in InN (indium nitride) are presented. The formation of lateral photo-Dember currents is induced by laser-illumination through a microstructured metal cover processed onto the InN substrate, causing an asymmetry in the lateral photogenerated charge carrier distribution. Our design uses simple metal structures, which are produced by conventional two-dimensional micro-structuring techniques. Having favoring properties as a photo-Dember material InN is particularly well-suited as a substrate for our emitters. We demonstrate that the emission intensity of the emitters can be significantly influenced by the structure of the metal cover leaving room for improvement by optimizing the masking structures.

  6. Formation and Temperature Effect of InN Nanodots by PA-MBE via Droplet Epitaxy Technique

    NASA Astrophysics Data System (ADS)

    Chen, Hugo Juin-Yu; Yang, Dian-Long; Huang, Tseh-Wet; Yu, Ing-Song

    2016-05-01

    In this report, self-organized indium nitride nanodots have been grown on Si (111) by droplet epitaxy method and their density can reach as high as 2.83 × 1011 cm-2 for the growth at low temperature of 250 °C. Based on the in situ reflection high-energy electron diffraction, the surface condition, indium droplets, and the formation of InN nanodots are identified during the epitaxy. The X-ray photoelectron spectroscopy and photoluminescence measurements have shown the formation of InN nanodots as well. The growth mechanism of InN nanodots could be described via the characterizations of indium droplets and InN nanodots using scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The density of the InN nanodots was less than that of the In droplets due to the surface diffusion and desorption of atoms during the nitridation and annealing process. The average size and density of InN nanodots can be controlled by the substrate temperatures during the growth. For the growth at lower temperature, we obtained the higher density and smaller average size of InN nanodots. To minimize the total surface energy, the coarsening and some preferred orientations of InN nanodots were observed for the growth at high temperature.

  7. CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES: Tetragonal Distortion of InN Thin Films by RBS/Channeling

    NASA Astrophysics Data System (ADS)

    Ding, Zhi-Bo; Wu, Wei; Wang, Kun; Fa, Tao; Yao, Shu-De

    2009-08-01

    Rutherford backscattering and channeling spectrometry (RBS/C) are used to identify the crystalline quality (χ min = 4.87%) of an InN thin film as a function of depth, and make a non-destructive quantitative analysis of the structure, in order to analyze the tetragonal distortion of the InN thin film at the depth determined.

  8. Microstructures of InN film on 4H-SiC (0001) substrate grown by RF-MBE

    NASA Astrophysics Data System (ADS)

    Jantawongrit, P.; Sanorpim, S.; Yaguchi, H.; Orihara, M.; Limsuwan, P.

    2015-08-01

    InN film was grown on 4H-SiC (0001) substrate by RF plasma-assisted molecular beam epitaxy (RF-MBE). Prior to the growth of InN film, an InN buffer layer with a thickness of ∼5.5 nm was grown on the substrate. Surface morphology, microstructure and structural quality of InN film were investigated. Micro-structural defects, such as stacking faults and anti-phase domain in InN film were carefully investigated using transmission electron microscopy (TEM). The results show that a high density of line contrasts, parallel to the growth direction (c-axis), was clearly observed in the grown InN film. Dark field TEM images recorded with diffraction vectors g=11\\bar{2}0 and g = 0002 revealed that such line contrasts evolved from a coalescence of the adjacent misoriented islands during the initial stage of the InN nucleation on the substrate surface. This InN nucleation also led to a generation of anti-phase domains. Project supported by the Thailand Center of Excellence in Physics (ThEP) and the King Mongkut's University of Technology Thonburi under The National Research University Project. One of the authors (S. Sanorpim) was supported by the National Research Council of Thailand (NRCT) and the Thai Government Stimulus Package 2 (TKK2555), under the Project for Establishment of Comprehensive Center for Innovative Food, Health Products and Agriculture.

  9. Electrical and electrothermal transport in InN: The roles of defects

    NASA Astrophysics Data System (ADS)

    Miller, N.; Ager, J. W.; Jones, R. E.; Smith, H. M.; Mayer, M. A.; Yu, K. M.; Hawkridge, M. E.; Liliental-Weber, Z.; Haller, E. E.; Walukiewicz, W.; Schaff, W. J.; Gallinat, C.; Koblmüller, G.; Speck, J. S.

    2009-12-01

    The transport properties of Mg doped and undoped InN films are studied with capacitance-voltage, thermopower, and Hall mobility measurements. A positive Seebeck coefficient is observed for Mg doped InN confirming p-type conductivity, though high doping and structural defect density can lead to n-type films. Transport measurements of undoped films are analyzed employing Rode's iterative Boltzmann equation method. Observed thermopower, Hall mobility, and dislocation density data for undoped films are consistent with calculations including the effects of charged line defect (donor-type dislocation) scattering.

  10. Electrical and optical properties of p-type InN

    SciTech Connect

    Mayer, Marie A.; Choi, Soojeong; Bierwagen, Oliver; Smith, Holland M.; Haller, Eugene E.; Speck, James S.; Walukiewicz, Wladek

    2011-01-01

    We have performed comprehensive studies of optical, thermoelectric and electrical properties of Mg doped InN with varying Mg doping levels and sample thicknesses. Room temperature photoluminescence spectra show a Mg acceptor related emission and the thermopower provides clear evidence for the presence of mobile holes. Although the effects of the hole transport are clearly observed in the temperature dependent electrical properties, the sign of the apparent Hall coefficient remains negative in all samples. We show that the standard model of two electrically well connected layers (n-type surface electron accumulation and p-type bulk) does not properly describe Hall effect in p-type InN.

  11. Two-dimensional electron gas in monolayer InN quantum wells

    SciTech Connect

    Pan, Wei; Dimakis, Emmanouil; Wang, George T.; Moustakas, Theodore D.; Tsui, Daniel C.

    2014-11-24

    We report in this letter experimental results that confirm the two-dimensional nature of the electron systems in monolayer InN quantum wells embedded in GaN barriers. The electron density and mobility of the two-dimensional electron system (2DES) in these InN quantum wells are 5×1015 cm-2 and 420 cm2 /Vs, respectively. Moreover, the diagonal resistance of the 2DES shows virtually no temperature dependence in a wide temperature range, indicating the topological nature of the 2DES.

  12. Two-dimensional electron gas in monolayer InN quantum wells

    DOE PAGES

    Pan, Wei; Dimakis, Emmanouil; Wang, George T.; Moustakas, Theodore D.; Tsui, Daniel C.

    2014-11-24

    We report in this letter experimental results that confirm the two-dimensional nature of the electron systems in monolayer InN quantum wells embedded in GaN barriers. The electron density and mobility of the two-dimensional electron system (2DES) in these InN quantum wells are 5×1015 cm-2 and 420 cm2 /Vs, respectively. Moreover, the diagonal resistance of the 2DES shows virtually no temperature dependence in a wide temperature range, indicating the topological nature of the 2DES.

  13. Growth mechanism and microstructure of low defect density InN (0001) In-face thin films on Si (111) substrates

    SciTech Connect

    Kehagias, Th.; Dimitrakopulos, G. P.; Koukoula, T.; Komninou, Ph.; Ajagunna, A. O.; Georgakilas, A.; Tsagaraki, K.; Adikimenakis, A.

    2013-10-28

    Transmission electron microscopy has been employed to analyze the direct nucleation and growth, by plasma-assisted molecular beam epitaxy, of high quality InN (0001) In-face thin films on (111) Si substrates. Critical steps of the heteroepitaxial growth process are InN nucleation at low substrate temperature under excessively high N-flux conditions and subsequent growth of the main InN epilayer at the optimum conditions, namely, substrate temperature 400–450 °C and In/N flux ratio close to 1. InN nucleation occurs in the form of a very high density of three dimensional (3D) islands, which coalesce very fast into a low surface roughness InN film. The reduced reactivity of Si at low temperature and its fast coverage by InN limit the amount of unintentional Si nitridation by the excessively high nitrogen flux and good bonding/adhesion of the InN film directly on the Si substrate is achieved. The subsequent overgrowth of the main InN epilayer, in a layer-by-layer growth mode that enhances the lateral growth of InN, reduces significantly the crystal mosaicity and the density of threading dislocations is about an order of magnitude less compared to InN films grown using an AlN/GaN intermediate nucleation/buffer layer on Si. The InN films exhibit the In-face polarity and very smooth atomically stepped surfaces.

  14. Golf Tournament Drives in a Win for the Children’s Inn | Poster

    Cancer.gov

    By Carolynne Keenan, Contributing Writer On September 23, golfers took to the Clustered Spires golf course in Frederick, Md., for a cause. The R&W Club Frederick hosted its inaugural golf tournament, with proceeds benefiting the National Institutes of Health (NIH) Children’s Inn.

  15. Effect of interfacial lattice mismatch on bulk carrier concentration and band gap of InN

    SciTech Connect

    Kuyyalil, Jithesh; Tangi, Malleswararao; Shivaprasad, S. M.

    2012-10-15

    The issue of ambiguous values of the band gap (0.6 to 2 eV) of InN thin film in literature has been addressed by a careful experiment. We have grown wurtzite InN films by PA-MBE simultaneously on differently modified c-plane sapphire substrates and characterized by complementary structural and chemical probes. Our studies discount Mie resonances caused by metallic In segregation at grain boundaries as the reason for low band gap values ( Almost-Equal-To 0.6 eV) and also the formation of Indium oxides and oxynitrides as the cause for high band gap value ( Almost-Equal-To 2.0 eV). It is observed that polycrystallinity arising from azimuthal miss-orientation of c-oriented wurtzite InN crystals increases the carrier concentration and the band gap values. We have reviewed the band gap, carrier concentration, and effective mass of InN in literature and our own measurements, which show that the Moss-Burstein relation with a non-parabolic conduction band accounts for the observed variation of band gap with carrier concentration.

  16. Self-assembled InN micro-mushrooms by upside-down pendeoepitaxy

    NASA Astrophysics Data System (ADS)

    Sarwar, A. T. M. Golam; Yang, Fan; Esser, Bryan D.; Kent, Thomas F.; McComb, David W.; Myers, Roberto C.

    2016-06-01

    Self-assembly of hexagonal InN micro-mushrooms on Si (111) substrates by molecular beam epitaxy is reported. Scanning electron microscopy (SEM) reveals hexagonal mushroom caps with smooth top surfaces and a step-like morphology at the bottom surface. A detailed growth study along with SEM measurements reveals that an upside-down pendeoepitaxy mechanism underlies the formation of these structures. Cryogenic temperature photoluminescence measurements on the InN disks show a dominant band-to-acceptor recombination peak at 0.68 eV. Cross-section annular bright field (ABF-) scanning transmission electron microscopy (STEM) reveals that the growth of these structures occurs along the [ 000 1 bar ] crystallographic orientation (N-face). Plan-view high angle annular dark field (HAADF) STEM in the center of the micro-disks reveals a hexagonal lattice indicative of stacking faults. However, at the outskirt of the micro-disk, surprisingly, a honeycomb lattice is observed in plan view STEM indicating a perfect freestanding Wurtzite InN disk that is free of stacking faults. This result opens a pathway for realizing strain-free, freestanding InN substrates.

  17. Pressure-Induced Metallization and Superconductivity in InP and InN

    NASA Astrophysics Data System (ADS)

    Iyakutti, K.; Rejila, V.; Rajarajeswari, M.; Nirmala Louis, C.; Mahalakshmi, S.

    The electronic band structure, structural phase transition, metallization and superconducting transition of cubic zinc blende-type indium phosphide (InP) and indium nitride (InN), under pressure, are studied using TB-LMTO method. These indium compounds become metals and superconductors under high pressure but before that they undergo structural phase transition from ZnS to NaCl structure. The ground-state properties and band gap values are compared with the experimental and previous theoretical results. From our analysis, it is found that the metallization pressure increases with increase of lattice constant. The superconducting transition temperatures (Tc) of InP and InN are obtained as a function of pressure for both the ZnS and NaCl structures and these compounds are identified as pressure-induced superconductors. When pressure is increased Tc increases in both the normal (ZnS) and high pressure (NaCl) structures. The dependence of Tc on electron-phonon mass enhancement factor λ shows that InP and InN are electron-phonon mediated superconductors. The non-occurrence of metallization, phase transition and onset of superconductivity simultaneously in InP and InN are confirmed.

  18. Nanostructural and electronic properties of polytypes in InN nanocolumns

    SciTech Connect

    Kioseoglou, J.; Koukoula, T.; Komninou, Ph.; Kehagias, Th.; Georgakilas, A.; Androulidaki, M.

    2013-08-21

    Transmission electron microscopy techniques and density functional theory calculations were employed to investigate the nanostructural and electronic properties of InN polytypes observed in InN nanocolumns, grown on Si(111) by molecular beam epitaxy. Moiré fringes and alternating hexagonal and cubic lattice stacking sequences along the c-axis, observed among the wurtzite layers, implied the presence of different structures embedded in the basic 2H structure of the nanocolumns. Quantitative electron diffraction analysis and high-resolution image simulations verified the coexistence of the wurtzite structure with the 4H, 6H, and the 3C zinc-blende structural polytypes. Total energies calculations established the 2H wurtzite structure as the most stable polytype. The band gap of all polytypes was found direct with the energies and the band gaps of the 4H (E{sub g} = 0.64 eV) and 6H (E{sub g} = 0.60 eV) structures calculated between the corresponding values of the 2H (E{sub g} = 0.75 eV) and 3C (E{sub g} = 0.49 eV) basic structures. Theoretical and experimental analysis showed that at the initial stages of growth InN nanocolumns were under tensile strain along both the basal plane and growth direction. Structural polytypes were then introduced in the form of embedded inclusions to accommodate the excess tensile strain along the growth direction, allowing the entire process of polymorphism to be the dominant strain relaxation mechanism of InN nanocolumns. Moreover, the lattice and energetic properties and band gap values of InN polytypes showed a linear dependence on hexagonality, while the presence of polytypes led to a characteristic broadening of the photoluminescence emission peak toward lower emission energies.

  19. Epitaxial growth of InN on nearly lattice-matched (Mn,Zn)Fe 2O 4

    NASA Astrophysics Data System (ADS)

    Ohta, J.; Mitamura, K.; Kobayashi, A.; Honke, T.; Fujioka, H.; Oshima, M.

    2006-01-01

    We have grown InN films on nearly lattice-matched (Mn,Zn)Fe 2O 4 (111) substrates at low temperatures by pulsed laser deposition (PLD) and investigated their structural properties. InN films grown at substrate temperatures above 400 °C show poor crystallinity, and their in-plane epitaxial relationship is [10-10]InN//[11-2](Mn,Zn)Fe 2O 4, which means that their lattice mismatch is quite large (11%). By contrast, high quality InN films with flat surfaces can be grown at growth temperatures lower than 150 °C with the ideal in-plane epitaxial relationship of [11-20]InN//[11-2](Mn,Zn)Fe 2O 4, which produces lattice mismatches of as low as 2.0%. X-ray reflectivity measurements have revealed that the thickness of the interfacial layer between the InN and the substrates is reduced from 14 to 8.4 nm when the growth temperature is decreased from 400 °C to room temperature. This suppression of the interface reactions by reducing the growth temperature is probably responsible for the improvement in crystalline quality. These results indicate that the use of (Mn,Zn)Fe 2O 4 (111) substrates at low growth temperatures allows us to achieve nearly lattice matched epitaxial growth of InN.

  20. Large-scale cubic InN nanocrystals by a combined solution- and vapor-phase method under silica confinement.

    PubMed

    Chen, Zhuo; Li, Yanan; Cao, Chuanbao; Zhao, Songrui; Fathololoumi, Saeed; Mi, Zetian; Xu, Xingyan

    2012-01-18

    Large-scale cubic InN nanocrystals were synthesized by a combined solution- and vapor-phase method under silica confinement. Nearly monodisperse cubic InN nanocrystals with uniform spherical shape were dispersed stably in various organic solvents after removal of the silica shells. The average size of InN nanocrystals is 5.7 ± 0.6 nm. Powder X-ray diffraction results indicate that the InN nanocrystals are of high crystallinity with a cubic phase. X-ray photoelectron spectroscopy and energy-dispersive spectroscopy confirm that the nanocrystals are composed of In and N elements. The InN nanocrystals exhibit infrared photoluminescence at room temperature, with a peak energy of ~0.62 eV, which is smaller than that of high-quality wurtzite InN (~0.65-0.7 eV) and is in agreement with theoretical calculations. The small emission peak energy of InN nanocrystals, as compared to other low-cost solution or vapor methods, reveals the superior crystalline quality of our samples, with low or negligible defect density. This work will significantly promote InN-based applications in IR optoelectronic device and biology. PMID:22224725

  1. InN thin-film transistors fabricated on polymer sheets using pulsed sputtering deposition at room temperature

    NASA Astrophysics Data System (ADS)

    Lye, Khe Shin; Kobayashi, Atsushi; Ueno, Kohei; Ohta, Jitsuo; Fujioka, Hiroshi

    2016-07-01

    Indium nitride (InN) is potentially suitable for the fabrication of high performance thin-film transistors (TFTs) because of its high electron mobility and peak electron velocity. However, InN is usually grown using a high temperature growth process, which is incompatible with large-area and lightweight TFT substrates. In this study, we report on the room temperature growth of InN films on flexible polyimide sheets using pulsed sputtering deposition. In addition, we report on the fabrication of InN-based TFTs on flexible polyimide sheets and the operation of these devices.

  2. Electrically injected near-infrared light emission from single InN nanowire p-i-n diode

    SciTech Connect

    Le, Binh Huy; Zhao, Songrui; Tran, Nhung Hong; Mi, Zetian

    2014-12-08

    We report on the achievement of electroluminescence emission of single InN p-i-n nanowire devices. InN p-i-n nanowire structures were grown directly on Si substrate by plasma-assisted molecular beam epitaxy and subsequently transferred to foreign substrate for the fabrication of single nanowire light emitting diodes. Electroluminescence emission with a peak energy of 0.71 eV (1.75 μm) was observed at 77 K. The measurement of near-bandgap electroluminescence provides unambiguous evidence for the achievement of p-type conduction of InN.

  3. Growth of InN nanorods prepared by plasma-assisted molecular beam epitaxy with varying Cr thicknesses

    NASA Astrophysics Data System (ADS)

    Liu, K. W.; Young, S. J.; Chang, S. J.; Hsueh, T. H.; Chen, Y. Z.; Chen, K. J.; Hung, H.; Wang, S. M.; Wu, Y. L.

    2012-05-01

    This study investigates how the thickness of Cr deposited on the Si substrate after the nitridation process influences the AIN buffer layer and the InN nanorods. Atomic force microscopy results reveal that different thicknesses of Cr form varying sizes of CrN nanoislands. The results of scanning electron microscopy and X-ray diffraction show that a Cr deposition thickness of 10 nm results in CrN nanoislands after the nitridation process, improving the quality and density of InN nanorods. A Cr layer that was too thick led to polycrystalline InN growth. The results of transmission electron microscopy indicate a baseball bat-like InN nanorod growth mechanism.

  4. R&W Club Frederick Raises $1,500 for The Children’s Inn at Annual Golf Tournament | Poster

    Cancer.gov

    Forty-four government and contractor employees, along with their friends and family members, took to the Maryland National Golf Club course this fall for a cause. The R&W Club Frederick held its third annual golf tournament at the Middletown, Md., golf course on Sept. 14 to raise funds for The Children’s Inn at NIH, which celebrated its 25th anniversary this year. The Inn provides support and a home away from home for seriously ill children and their families receiving treatment at the NIH Clinical Center. Through the tournament, the club raised approximately $1,500 for The Children’s Inn, according to Tanya Ransom, biologist, NCI Center for Cancer Research, and secretary of the R&W Club Frederick. She also coordinated the golf tournament. After the tournament, a silent auction of sports memorabilia and collectibles, sponsored by Great Moments, Frederick, was held, and a portion of the proceeds also went to the Inn.

  5. Study of InN nanorods growth mechanism using ultrathin Au layer by plasma-assisted MBE on Si(111)

    NASA Astrophysics Data System (ADS)

    Kumar, Mahesh; Rajpalke, Mohana K.; Roul, Basanta; Bhat, Thirumaleshwara N.; Krupanidhi, S. B.

    2014-01-01

    InN nanorods (NRs) were grown on Si(111) substrate by plasma-assisted molecular beam epitaxy. The growth of InN NRs has been demonstrated using an electron-beam evaporated (~2 nm) Au layer prior to the initiation of growth. The structure and morphology of as deposited Au film, annealed at 600 °C, and InN NRs were investigated using X-ray photoelectron spectroscopy and scanning electron microscopy. Chemical characterization was performed with energy dispersive X-ray analysis. Single-crystalline wurtzite structure of InN NRs is verified by transmission electron microscopy. The formation process of NRs is investigated and a qualitative mechanism is proposed.

  6. Epitaxial relationship of semipolar s-plane (1101) InN grown on r-plane sapphire

    SciTech Connect

    Dimitrakopulos, G. P.

    2012-07-02

    The heteroepitaxy of semipolar s-plane (1101) InN grown directly on r-plane sapphire by plasma-assisted molecular beam epitaxy is studied using transmission electron microscopy techniques. The epitaxial relationship is determined to be (1101){sub InN} Parallel-To (1102){sub Al{sub 2O{sub 3}}}, [1120]{sub InN} Parallel-To [2021]{sub Al{sub 2O{sub 3}}}, [1102]{sub InN}{approx} Parallel-To [0221]{sub Al{sub 2O{sub 3}}}, which ensures a 0.7% misfit along [1120]{sub InN}. Two orientation variants are identified. Proposed geometrical factors contributing to the high density of basal stacking faults, partial dislocations, and sphalerite cubic pockets include the misfit accommodation and reduction, as well as the accommodation of lattice twist.

  7. Sulfur passivation of surface electrons in highly Mg-doped InN

    SciTech Connect

    Linhart, W. M.; Veal, T. D.; Chai, J.; McConville, C. F.; Durbin, S. M.

    2013-09-14

    Electron accumulation with a sheet density greater than 10{sup 13} cm{sup −2} usually occurs at InN surfaces. Here, the effects of treatment with ammonium sulfide ((NH{sub 4}){sub 2}S{sub x}) on the surface electronic properties of highly Mg-doped InN (>4×10{sup 18} cm{sup −3}) have been investigated with high resolution x-ray photoemission spectroscopy. The valence band photoemission spectra show that the surface Fermi level decreases by approximately 0.08 eV with (NH{sub 4}){sub 2}S{sub x} treatment, resulting in a decrease of the downward band bending and up to a 70% reduction in the surface electron sheet density.

  8. Epitaxial growth, electrical and optical properties of a-plane InN on r-plane sapphire

    SciTech Connect

    Ajagunna, A. O.; Iliopoulos, E.; Tsiakatouras, G.; Tsagaraki, K.; Androulidaki, M.; Georgakilas, A.

    2010-01-15

    The heteroepitaxy of a-plane (1120) InN films on r-plane (1102) sapphire substrates, by nitrogen radio frequency plasma-assisted molecular beam epitaxy, has been investigated and compared to that of c-plane (0001) InN. The epitaxial growth of a-plane InN proceeded through the nucleation, growth, and coalescence of three-dimensional islands, resulting in surface roughness that increased monotonically with epilayer thickness. The full width at half maximum of (1120) x-ray diffraction rocking curves decreased significantly with increasing InN thickness, characteristic of structural improvement, and it reached the value of 24 arcmin for a 1 {mu}m thick film. Hall-effect measurements exhibited a similar dependence of electron concentration and mobility on thickness for both the a- and c-plane InN films. The analysis of the Hall-effect measurements, by considering the contribution of two conducting layers, indicates a similar accumulation of low mobility electrons with N{sub s}>10{sup 14} cm{sup -2} at the films' surface/interfacial region for both the a- and c-plane InN films. From optical transmittance measurements, the absorption edge of 0.768 eV was determined for the 1 {mu}m a-plane film, consistent with the expected Burstein-Moss effect. Photoluminescence spectra exhibited a lower energy peak at 0.631 eV, suggesting defect-related transitions.

  9. Crystallinity, Surface Morphology, and Photoelectrochemical Effects in Conical InP and InN Nanowires Grown on Silicon.

    PubMed

    Parameshwaran, Vijay; Xu, Xiaoqing; Clemens, Bruce

    2016-08-24

    The growth conditions of two types of indium-based III-V nanowires, InP and InN, are tailored such that instead of yielding conventional wire-type morphologies, single-crystal conical structures are formed with an enlarged diameter either near the base or near the tip. By using indium droplets as a growth catalyst, combined with an excess indium supply during growth, "ice cream cone" type structures are formed with a nanowire "cone" and an indium-based "ice cream" droplet on top for both InP and InN. Surface polycrystallinity and annihilation of the catalyst tip of the conical InP nanowires are observed when the indium supply is turned off during the growth process. This growth design technique is extended to create single-crystal InN nanowires with the same morphology. Conical InN nanowires with an enlarged base are obtained through the use of an excess combined Au-In growth catalyst. Electrochemical studies of the InP nanowires on silicon demonstrate a reduction photocurrent as a proof of photovolatic behavior and provide insight as to how the observed surface polycrystallinity and the resulting interface affect these device-level properties. Additionally, a photovoltage is induced in both types of conical InN nanowires on silicon, which is not replicated in epitaxial InN thin films. PMID:27455379

  10. Stability of Mg-incorporated InN surfaces: first-principles study

    NASA Astrophysics Data System (ADS)

    Akiyama, T.; Nakamura, K.; Ito, T.; Song, J.-H.; Freeman, A. J.

    2009-03-01

    InN films are attractive materials for electronic and optelectronic applications. The growth of InN eptitaxial films with n-type and p-type conductivity has traditionally been performed along the polar <0001> directionootnotetextR.E. Jones et al., Phys. Rev. Lett, 96, 125505 (2006), which may result in large polarization fields along the growth direction, reducing the radiative efficiency of quantum-well light emitters. To overcome this drawback, the growth along nonpolar orientation such as (1010) and (1120) planes and its p-type doping have been recently carried out. We have addressed this issue by performing first-principles pseudopotential calculations for Mg-incorporated InN surfaces in various orientations, including (1010) and (1120) as well as (0001) and (0001) surfacesootnotetextJ.-H. Song et al., Phys. Rev. Lett. 101, 106803 (2008). The calculated surface energies demonstrate that qualitative trends in the stability of Mg-incorporated surfaces agree with those on GaN surfaces ootnotetextJ.E. Northrup, Appl. Phys. Lett. 86, 122108 (2005), although several surface reconstructions different from those on GaN surfaces are obtained. The effects of growth conditions on p-type doping are also discussed.

  11. Photoelectrochemical properties of InN nanowire photoelectrodes for solar water splitting

    NASA Astrophysics Data System (ADS)

    Kamimura, J.; Bogdanoff, P.; Ramsteiner, M.; Geelhaar, L.; Riechert, H.

    2016-07-01

    InN nanowires were grown on Si(111) substrates by plasma-assisted molecular beam epitaxy. Raman spectroscopy showed that the nanowires were strain-free and allowed the deduction of a free carrier concentration of 1–2 × 1018 cm‑3. This value was confirmed by a Mott–Schottky analysis of electrolyte-based capacitance-voltage measurements. In addition, these measurements directly revealed the existence of a surface accumulation layer in the InN nanowires. In cyclic voltammetry measurements under irradiation from a Xe lamp with about 100 mW cm‑2, high photocurrents of about 4 and 11 mA cm‑2 were observed at 1.23 and 1.63 V bias potential versus reversible hydrogen electrode, respectively, using H2O2 as a hole scavenger. By comparing the photocurrent with and without H2O2, the main limiting factor in the performance of InN nanowire photoanodes was identified to be the poor catalytic efficiency for water oxidation at the surface, followed by parasitic bulk recombination.

  12. Photoelectrochemical properties of InN nanowire photoelectrodes for solar water splitting

    NASA Astrophysics Data System (ADS)

    Kamimura, J.; Bogdanoff, P.; Ramsteiner, M.; Geelhaar, L.; Riechert, H.

    2016-07-01

    InN nanowires were grown on Si(111) substrates by plasma-assisted molecular beam epitaxy. Raman spectroscopy showed that the nanowires were strain-free and allowed the deduction of a free carrier concentration of 1-2 × 1018 cm-3. This value was confirmed by a Mott-Schottky analysis of electrolyte-based capacitance-voltage measurements. In addition, these measurements directly revealed the existence of a surface accumulation layer in the InN nanowires. In cyclic voltammetry measurements under irradiation from a Xe lamp with about 100 mW cm-2, high photocurrents of about 4 and 11 mA cm-2 were observed at 1.23 and 1.63 V bias potential versus reversible hydrogen electrode, respectively, using H2O2 as a hole scavenger. By comparing the photocurrent with and without H2O2, the main limiting factor in the performance of InN nanowire photoanodes was identified to be the poor catalytic efficiency for water oxidation at the surface, followed by parasitic bulk recombination.

  13. InN nanorods prepared with CrN nanoislands by plasma-assisted molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Liu, Kuang-Wei; Chang, Shoou-Jinn; Young, Sheng-Joue; Hsueh, Tao-Hung; Hung, Hung; Mai, Yu-Chun; Wang, Shih-Ming; Chen, Kuan-Jen; Wu, Ya-Ling; Chen, Yue-Zhang

    2011-07-01

    The authors report the influence of CrN nanoisland inserted on growth of baseball-bat InN nanorods by plasma-assisted molecular beam epitaxy under In-rich conditions. By inserting CrN nanoislands between AlN nucleation layer and the Si (111) substrate, it was found that we could reduce strain form Si by inserting CrN nanoisland, FWHM of the x-ray rocking curve measured from InN nanorods from 3,299 reduced to 2,115 arcsec. It is due to the larger strain from lattice miss-match of the film-like InN structure; however, the strain from lattice miss-match was obvious reduced owing to CrN nanoisland inserted. The TEM images confirmed the CrN structures and In droplets dissociation from InN, by these results, we can speculate the growth mechanism of baseball-bat-like InN nanorods.

  14. Self-Catalyzed Growth of Vertically Aligned InN Nanorods by Metal-Organic Vapor Phase Epitaxy.

    PubMed

    Tessarek, C; Fladischer, S; Dieker, C; Sarau, G; Hoffmann, B; Bashouti, M; Göbelt, M; Heilmann, M; Latzel, M; Butzen, E; Figge, S; Gust, A; Höflich, K; Feichtner, T; Büchele, M; Schwarzburg, K; Spiecker, E; Christiansen, S

    2016-06-01

    Vertically aligned hexagonal InN nanorods were grown mask-free by conventional metal-organic vapor phase epitaxy without any foreign catalyst. The In droplets on top of the nanorods indicate a self-catalytic vapor-liquid-solid growth mode. A systematic study on important growth parameters has been carried out for the optimization of nanorod morphology. The nanorod N-polarity, induced by high temperature nitridation of the sapphire substrate, is necessary to achieve vertical growth. Hydrogen, usually inapplicable during InN growth due to formation of metallic indium, and silane are needed to enhance the aspect ratio and to reduce parasitic deposition beside the nanorods on the sapphire surface. The results reveal many similarities between InN and GaN nanorod growth showing that the process despite the large difference in growth temperature is similar. Transmission electron microscopy, spatially resolved energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been performed to analyze the structural properties. Spatially resolved cathodoluminescence investigations are carried out to verify the optical activity of the InN nanorods. The InN nanorods are expected to be the material of choice for high-efficiency hot carrier solar cells. PMID:27187840

  15. In-situ SiNx/InN structures for InN field-effect transistors

    NASA Astrophysics Data System (ADS)

    Zervos, Ch.; Adikimenakis, A.; Beleniotis, P.; Kostopoulos, A.; Kayambaki, M.; Tsagaraki, K.; Konstantinidis, G.; Georgakilas, A.

    2016-04-01

    Critical aspects of InN channel field-effect transistors (FETs) have been investigated. SiNx dielectric layers were deposited in-situ, in the molecular beam epitaxy system, on the surface of 2 nm InN layers grown on GaN (0001) buffer layers. Metal-insulator-semiconductor Ni/SiNx/InN capacitors were analyzed by capacitance-voltage (C-V) and current-voltage measurements and were used as gates in InN FET transistors (MISFETs). Comparison of the experimental C-V results with self-consistent Schrödinger-Poisson calculations indicates the presence of a positive charge at the SiNx/InN interface of Qif ≈ 4.4 - 4.8 × 1013 cm-2, assuming complete InN strain relaxation. Operation of InN MISFETs was demonstrated, but their performance was limited by a catastrophic breakdown at drain-source voltages above 2.5-3.0 V, the low electron mobility, and high series resistances of the structures.

  16. InN nanorods prepared with CrN nanoislands by plasma-assisted molecular beam epitaxy.

    PubMed

    Liu, Kuang-Wei; Chang, Shoou-Jinn; Young, Sheng-Joue; Hsueh, Tao-Hung; Hung, Hung; Mai, Yu-Chun; Wang, Shih-Ming; Chen, Kuan-Jen; Wu, Ya-Ling; Chen, Yue-Zhang

    2011-01-01

    The authors report the influence of CrN nanoisland inserted on growth of baseball-bat InN nanorods by plasma-assisted molecular beam epitaxy under In-rich conditions. By inserting CrN nanoislands between AlN nucleation layer and the Si (111) substrate, it was found that we could reduce strain form Si by inserting CrN nanoisland, FWHM of the x-ray rocking curve measured from InN nanorods from 3,299 reduced to 2,115 arcsec. It is due to the larger strain from lattice miss-match of the film-like InN structure; however, the strain from lattice miss-match was obvious reduced owing to CrN nanoisland inserted. The TEM images confirmed the CrN structures and In droplets dissociation from InN, by these results, we can speculate the growth mechanism of baseball-bat-like InN nanorods. PMID:21736722

  17. InN nanorods prepared with CrN nanoislands by plasma-assisted molecular beam epitaxy

    PubMed Central

    2011-01-01

    The authors report the influence of CrN nanoisland inserted on growth of baseball-bat InN nanorods by plasma-assisted molecular beam epitaxy under In-rich conditions. By inserting CrN nanoislands between AlN nucleation layer and the Si (111) substrate, it was found that we could reduce strain form Si by inserting CrN nanoisland, FWHM of the x-ray rocking curve measured from InN nanorods from 3,299 reduced to 2,115 arcsec. It is due to the larger strain from lattice miss-match of the film-like InN structure; however, the strain from lattice miss-match was obvious reduced owing to CrN nanoisland inserted. The TEM images confirmed the CrN structures and In droplets dissociation from InN, by these results, we can speculate the growth mechanism of baseball-bat-like InN nanorods. PMID:21736722

  18. InN nanorods prepared with CrN nanoislands by plasma-assisted molecular beam epitaxy.

    PubMed

    Liu, Kuang-Wei; Chang, Shoou-Jinn; Young, Sheng-Joue; Hsueh, Tao-Hung; Hung, Hung; Mai, Yu-Chun; Wang, Shih-Ming; Chen, Kuan-Jen; Wu, Ya-Ling; Chen, Yue-Zhang

    2011-01-01

    The authors report the influence of CrN nanoisland inserted on growth of baseball-bat InN nanorods by plasma-assisted molecular beam epitaxy under In-rich conditions. By inserting CrN nanoislands between AlN nucleation layer and the Si (111) substrate, it was found that we could reduce strain form Si by inserting CrN nanoisland, FWHM of the x-ray rocking curve measured from InN nanorods from 3,299 reduced to 2,115 arcsec. It is due to the larger strain from lattice miss-match of the film-like InN structure; however, the strain from lattice miss-match was obvious reduced owing to CrN nanoisland inserted. The TEM images confirmed the CrN structures and In droplets dissociation from InN, by these results, we can speculate the growth mechanism of baseball-bat-like InN nanorods.

  19. Mie Resonances, Infrared Emission, and the Band Gap of InN

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Ivanov, S. V.; Jmerik, V. N.; Solnyshkov, D. D.; Vekshin, V. A.; Kop'ev, P. S.; Vasson, A.; Leymarie, J.; Kavokin, A.; Amano, H.; Shimono, K.; Kasic, A.; Monemar, B.

    2004-03-01

    Mie resonances due to scattering or absorption of light in InN-containing clusters of metallic In may have been erroneously interpreted as the infrared band gap absorption in tens of papers. Here we show by direct thermally detected optical absorption measurements that the true band gap of InN is markedly wider than the currently accepted 0.7eV. Microcathodoluminescence studies complemented by the imaging of metallic In have shown that bright infrared emission at 0.7 0.8eV arises in a close vicinity of In inclusions and is likely associated with surface states at the metal/InN interfaces.

  20. Growth of Well-Aligned InN Nanorods on Amorphous Glass Substrates.

    PubMed

    Li, Huijie; Zhao, Guijuan; Wei, Hongyuan; Wang, Lianshan; Chen, Zhen; Yang, Shaoyan

    2016-12-01

    The growth of well-aligned nanorods on amorphous substrates can pave the way to fabricate large-scale and low-cost devices. In this work, we successfully prepared vertically well-aligned c-axis InN nanorods on amorphous glass substrate by metal-organic chemical vapor deposition. The products formed directly on bare glass are randomly oriented without preferential growth direction. By inserting a GaN/Ti interlayer, the nanowire alignment can be greatly improved as indicated by scanning electron microscopy and X-ray diffraction. PMID:27229517

  1. Near-infrared InN quantum dots on high-In composition InGaN

    SciTech Connect

    Soto Rodriguez, Paul E. D.; Gomez, Victor J.; Kumar, Praveen; Calleja, Enrique; Noetzel, Richard

    2013-04-01

    We report the growth of InN quantum dots (QDs) on thick InGaN layers with high In composition (>50%) by molecular beam epitaxy. Optimized growth conditions are identified for the InGaN layers at reduced growth temperature and increased active N flux resulting in minimized phase separation and defect generation. The InN QDs grown on top of the optimized InGaN layer exhibit small size, high density, and photoluminescence up to room temperature. The InN/InGaN QDs reveal excellent potential for intermediate band solar cells with the InGaN and InN QD bandgap energies tuned to the best match of absorption to the solar spectrum.

  2. Different evolutionary pathways from B4 to B1 phase in AlN and InN: metadynamics investigations.

    PubMed

    Duan, Yifeng; Qin, Lixia; Liu, Hanyu

    2016-05-25

    Pressure-induced B4-B1 phase transitions of AlN and InN at ambient temperature are systematically investigated using density functional-based metadynamics simulations. A homogeneous deformation path, which is energetically favorable, is through a hexagonal structure for AlN, and through a tetragonal structure for InN. Furthermore, the dynamical stability, instead of the mechanical stability, is crucial to determining the phase-transition paths: the intermediate hexagonal structure can remain stable, whereas the tetragonal structure is always unstable. The B4 phase always shows the direct band gap before the occurrence of structure transition, while the band gap of stable intermediate hexagonal phase is indirect for AlN. Finally, the band gap of the ultimate cubic phase is direct for AlN and indirect for InN, due to the strong p-d repulsion at the R point. PMID:27120439

  3. Low-temperature (≥400 °C) growth of InN by metalorganic vapor phase epitaxy using an NH3 decomposition catalyst

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akio; Kodama, Kazuki; Shigekawa, Naoteru; Matsuoka, Takashi; Kuzuhara, Masaaki

    2016-05-01

    In this paper, we report the metalorganic vapor phase epitaxial (MOVPE) growth of InN using a NiO-based pellet-type NH3 decomposition catalyst. The use of the catalyst significantly changes the growth behavior of InN, which is dependent on the growth temperature (T g). Continuous InN films without the incorporation of metallic In and a cubic phase are grown at T g = 400–480 °C. An InN film grown at T g ≈ 450 °C has a full-width at half maximum (FWHM) of 376 arcsec in the X-ray rocking curve for InN(0002) reflection. At T g ≥ 500 °C, the deposition rate of InN rapidly decreases and the deposited films become discontinuous with large (ca. 1 µm) pyramidal grains of InN. Depositions are scarcely obtained at T g ≥ 600 °C. Such changes in the growth behavior of InN are governed by the NH3 decomposition.

  4. A Dance Class, a Drag King, & the Pedagogical Possibilities of Performative Hip-Hop: An Interview with Carmen Morrison & Alex U. Inn

    ERIC Educational Resources Information Center

    Schönfeldt-Aultman, Scott M.; Morrison, Carmen

    2015-01-01

    Alex U. Inn is the co-founder and one of the two MCs of the hip-hop drag king group, Momma's Boyz. Momma's Boyz celebrated their tenth anniversary in 2014. Carmen Morrison is the offstage name of Alex U. Inn, though "Carmen" now goes by Alex offstage, as well. Within this interview, the names "Carmen" and "Alex" are…

  5. Growth of wurtzite InN on bulk In{sub 2}O{sub 3}(111) wafers

    SciTech Connect

    Sadofev, Sergey; Cho, Yong Jin; Brandt, Oliver; Ramsteiner, Manfred; Calarco, Raffaella; Riechert, Henning; Erwin, Steven C.; Galazka, Zbigniew; Korytov, Maxym; Albrecht, Martin; Uecker, Reinhard; Fornari, Roberto

    2012-10-22

    A single phase InN epitaxial film is grown on a bulk In{sub 2}O{sub 3}(111) wafer by plasma-assisted molecular beam epitaxy. The InN/In{sub 2}O{sub 3} orientation relationship is found to be (0001) parallel (111) and [1100] parallel [112]. High quality of the layer is confirmed by the small widths of the x-ray rocking curves, the sharp interfaces revealed by transmission electron microscopy, the narrow spectral width of the Raman E{sub 2}{sup h} vibrational mode, and the position of the photoluminescence band close to the fundamental band gap of InN.

  6. Resonant raman scattering and dispersion of polar optical and acoustic phonons in hexagonal inn

    SciTech Connect

    Davydov, V. Yu. Klochikhin, A. A.; Smirnov, A. N.; Strashkova, I. Yu.; Krylov, A. S.; Lu Hai; Schaff, William J.; Lee, H.-M.; Hong, Y.-L.; Gwo, S.

    2010-02-15

    It is shown that a study of the dependence of impurity-related resonant first-order Raman scattering on the frequency of excitation light makes it possible to observe the dispersion of polar optical and acoustic branches of vibrational spectrum in hexagonal InN within a wide range of wave vectors. It is established that the wave vectors of excited phonons are uniquely related to the energy of excitation photon. Frequencies of longitudinal optical phonons E{sub 1}(LO) and A{sub 1}(LO) in hexagonal InN were measured in the range of excitation-photon energies from 2.81 to 1.17 eV and the frequencies of longitudinal acoustic phonons were measured in the range 2.81-1.83 eV of excitation-photon energies. The obtained dependences made it possible to extrapolate the dispersion of phonons A{sub 1}(LO) and E{sub 1}(LO) to as far as the point {Gamma} in the Brillouin zone and estimate the center-band energies of these phonons (these energies have not been uniquely determined so far).

  7. From Amateur Astronomer to Observatory Director: The Curious Case of R. T. A. Innes

    NASA Astrophysics Data System (ADS)

    Orchiston, Wayne

    Robert Innes was one of a select band of amateur astronomers who made the transition to professional ranks towards the end of the nineteenth century. Initially he had a passion for mathematical astronomy, but after settling in Sydney he developed a taste for observational astronomy, specialising in the search for new double stars. He quickly became known for his success in this field and for his publications on solar system perturbations, and with John Tebbutt's patronage managed to secure a clerical position at the Royal Observatory, Cape of Good Hope. Once there he continued to observe in his spare time and to publish, and, with strong support from Sir David Gill, was appointed founding Director of the Transvaal Observatory. By the time he died in 1933, Innes had received an honorary D.Sc. from Leiden University, and had established an international reputation as a positional astronomer. This paper provides an interesting case study of a well-known `amateur-turned-professional', and an example of the ways in which patronage played a key role in nineteenth and early twentieth century Australian and South African astronomy.

  8. ATOMIC AND MOLECULAR PHYSICS: First-Principles Study on Native Defect Complexes in InN

    NASA Astrophysics Data System (ADS)

    Zhao, Feng-Qi; Shi, Jun-Jie; Yang, Mao

    2010-01-01

    We present first-principles calculations of the formation energy of different native defects and their complexes in wurtzite InN using density-functional theory and the pseudopotential plane-wave method. Our calculations are aimed in the three cases: N/In = 1, N/In > 1 (N-rich), and N/In < 1 (In-rich). Our results indicate that the antisite defect has the lowest formation energy under N/In = 1. The formation energy of nitrogen interstitial (nitrogen vacancy) defect is significantly low under the N-rich (In-rich) condition. Thus the antisite defect is an important defect if N/In = 1, and the nitrogen interstitial (nitrogen vacancy) defect is a vital defect under the N-rich (In-rich) condition. The atomic site relaxation around the nitrogen interstitial and vacancy is investigated. Our calculations show that the nitrogen vacancy cannot be observed although it is one of the most important defects in InN. Our results are confirmed by experiments.

  9. Initial exploration of growth of InN by electrochemical solution growth.

    SciTech Connect

    Waldrip, Karen Elizabeth

    2010-02-01

    This report summarizes a brief and unsuccessful attempt to grow indium nitride via the electrochemical solution growth method and a modification thereof. Described in this report is a brief effort using a $50,000 LDRD award to explore the possibilities of applying the Electrochemical Solution Growth (ESG) technique to the growth of indium nitride (InN). The ability to grow bulk InN would be exciting from a scientific perspective, and a commercial incentive lies in the potential of extending the ESG technique to grow homogeneous, bulk alloys of In{sub x}Ga{sub 1-x}N for light emitting diodes (LEDs) operating in the green region of the spectrum. Indium nitride is the most difficult of the III-nitrides to grow due to its very high equilibrium vapor pressure of nitrogen1. It is several orders of magnitude higher than for gallium nitride or aluminum nitride. InN has a bandgap energy of 0.7eV, and achieving its growth in bulk for large area, high quality substrates would permit the fabrication of LEDs operating in the infrared. By alloying with GaN and AlN, the bulk material used as substrates would enable high efficiency emission wavelengths that could be tailored all the way through the deep ultraviolet. In addition, InN has been shown to have very high electronic mobilities (2700 cm{sup 2}/V s), making it a promising material for transistors and even terahertz emitters. Several attempts at synthesizing InN have been made by several groups. It was shown that metallic indium does not interact with unactivated nitrogen even at very high temperatures. Thus sets up an incompatibility between the precursors in all growth methods: a tradeoff between thermally activating the nitrogen-containing precursor and the low decomposition temperature of solid InN. We have been working to develop a novel growth technique that circumvents the difficulties of other bulk growth techniques by precipitating the column III nitrides from a solvent, such as a molten chloride salt, that

  10. Elimination of surface band bending on N-polar InN with thin GaN capping

    SciTech Connect

    Kuzmík, J. Haščík, Š.; Kučera, M.; Kúdela, R.; Dobročka, E.; Adikimenakis, A.; Mičušík, M.; Gregor, M.; Plecenik, A.; Georgakilas, A.

    2015-11-09

    0.5–1 μm thick InN (0001) films grown by molecular-beam epitaxy with N- or In-polarity are investigated for the presence of native oxide, surface energy band bending, and effects introduced by 2 to 4 monolayers of GaN capping. Ex situ angle-resolved x-ray photo-electron spectroscopy is used to construct near-surface (GaN)/InN energy profiles, which is combined with deconvolution of In3d signal to trace the presence of InN native oxide for different types of polarity and capping. Downwards surface energy band bending was observed on bare samples with native oxide, regardless of the polarity. It was found that the In-polar InN surface is most readily oxidized, however, with only slightly less band bending if compared with the N-polar sample. On the other hand, InN surface oxidation was effectively mitigated by GaN capping. Still, as confirmed by ultra-violet photo-electron spectroscopy and by energy band diagram calculations, thin GaN cap layer may provide negative piezoelectric polarization charge at the GaN/InN hetero-interface of the N-polar sample, in addition to the passivation effect. These effects raised the band diagram up by about 0.65 eV, reaching a flat-band profile.

  11. MBE Growth of InN/GaN(0001) and Shape Transitions of InN islands

    NASA Astrophysics Data System (ADS)

    Cao, Yongge; Xie, Maohai; Liu, Ying; Ng, Y. F.

    2003-03-01

    Plasma-assisted molecular-beam epitaxial growth of InN on GaN(0001) is investigated. Both layer-by-layer and Stranski-Krastanov (SK) growth modes are observed under different growth windows. Strain relaxation is studied by real-time recording of the in-plane lattice spacing evolutions on RHEED pattern, which suggest a gradual relaxation of the strain in InN film commenced during the first bilayer (BL) deposition and almost completed after 2-4 BLs. For SK growth, 3D islanding initiates after the strain has mostly been relieved, presumably by dislocations. Based on statistical analysis, the shape transitions of 3D islands are firstly observed in the III-nitrides system. The InN islands transform gradually from pyramids to platelets with increasing of In flux. Under In-rich growth condition, the reverse trend of island shape evolution dependence on volume size, compared with Equilibrium Crystal Shape (ECS) theory, is induced by the Indium self-surfactant effects, in which Indium adlayer on the top surface of InN islands will depress the thermodynamic driving force for the vertical growth of 3D islands. Lateral growth of 3D islands is not only the result of kinetic process but also favored by thermodynamics while Indium self-surfactant exist.

  12. Effect of Mg doping on the structural and free-charge carrier properties of InN films

    SciTech Connect

    Xie, M.-Y.; Ben Sedrine, N.; Hung, L.; Monemar, B.; Darakchieva, V.; Schöche, S.; Hofmann, T.; Schubert, M.; Wang, X.; Yoshikawa, A.; Wang, K.; Araki, T.; Nanishi, Y.

    2014-04-28

    We present a comprehensive study of free-charge carrier and structural properties of two sets of InN films grown by molecular beam epitaxy and systematically doped with Mg from 1.0 × 10{sup 18} cm{sup −3} to 3.9 × 10{sup 21} cm{sup −3}. The free electron and hole concentration, mobility, and plasmon broadening parameters are determined by infrared spectroscopic ellipsometry. The lattice parameters, microstructure, and surface morphology are determined by high-resolution X-ray diffraction and atomic force microscopy. Consistent results on the free-charge carrier type are found in the two sets of InN films and it is inferred that p-type conductivity could be achieved for 1.0 × 10{sup 18} cm{sup −3} ≲ [Mg] ≲ 9.0 × 10{sup 19} cm{sup −3}. The systematic change of free-charge carrier properties with Mg concentration is discussed in relation to the evolution of extended defect density and growth mode. A comparison between the structural characteristics and free electron concentrations in the films provides insights in the role of extended and point defects for the n-type conductivity in InN. It further allows to suggest pathways for achieving compensated InN material with relatively high electron mobility and low defect densities. The critical values of Mg concentration for which polarity inversion and formation of zinc-blende InN occurred are determined. Finally, the effect of Mg doping on the lattice parameters is established and different contributions to the strain in the films are discussed.

  13. Strain Relief Analysis of InN Quantum Dots Grown on GaN

    PubMed Central

    2007-01-01

    We present a study by transmission electron microscopy (TEM) of the strain state of individual InN quantum dots (QDs) grown on GaN substrates. Moiré fringe and high resolution TEM analyses showed that the QDs are almost fully relaxed due to the generation of a 60° misfit dislocation network at the InN/GaN interface. By applying the Geometric Phase Algorithm to plan-view high-resolution micrographs, we show that this network consists of three essentially non-interacting sets of misfit dislocations lying along the directions. Close to the edge of the QD, the dislocations curve to meet the surface and form a network of threading dislocations surrounding the system. PMID:21794190

  14. Inhomogeneous InGaN and InN with In-enriched Nanostructures

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Ivanov, S. V.; Jmerik, V. N.; Mizerov, A. M.; Leymarie, J.; Vasson, A.; Monemar, B.; Kop'ev, P. S.

    2007-04-01

    We present optical evidences for formation of In-enriched nanostructures in InxGa1-xN alloys (x=0.2-1.0) grown by MBE. Two-band photoluminescence (PL) has been recorded in several InxGa1-xN films (x⩾0.4), with the lowest line being in the infrared range. An additional absorption band has been revealed below the principal edge by thermally detected optical absorption studies even in perfect layers exhibiting exciton-like features in PL excitation spectra. A significant PL intensity increase along an InN layer is consistent with with the appearance of distinct In precipitates. These findings are discussed as related to extra optical losses and plasmon-induced PL enhancement.

  15. Solar hot water system installed at Quality Inn, Key West, Florida

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar energy hot water system installed in the Quality Inn, Key West, Florida, which consists of four buildings is described. Three buildings are low-rise, two-story buildings containing 100 rooms. The fourth is a four-story building with 48 rooms. The solar system was designed to provide approximately 50 percent of the energy required for the domestic hot water system. The solar system consists of approximately 1400 square feet of flat plate collector, two 500 gallon storage tanks, a circulating pump, and a controller. Operation of the system was begun in April 1978, and has continued to date with only three minor interruptions for pump repair. In the first year of operation, it was determined that the use of the solar facility resulted in forty percent fuel savings.

  16. Temperature dependences of the contact resistivity in ohmic contacts to n{sup +}-InN

    SciTech Connect

    Sachenko, A. V.; Belyaev, A. E.; Boltovets, N. S.; Brunkov, P. N.; Jmerik, V. N.; Ivanov, S. V.; Kapitanchuk, L. M.; Konakova, R. V. Klad’ko, V. P.; Romanets, P. N.; Saja, P. O.; Safryuk, N. V.; Sheremet, V. N.

    2015-04-15

    The temperature dependences of the contact resistivity (ρ{sub c}) of ohmic contacts based on the Au-Ti-Pd-InN system are measured at an InN doping level of 2 × 10{sup 18} cm{sup −3} in the temperature range of 4.2–300 K. At temperatures T > 150 K, linearly increasing dependences ρ{sub c}(T) are obtained. The dependences are explained within the mechanism of thermionic current flow through metal shunts associated with dislocations. Good agreement between theoretical and experimental dependences is achieved assuming that the flowing current is limited by the total resistance of the metal shunts, and the density of conductive dislocations is ∼5 × 10{sup 9} cm{sup −2}. Using the X-ray diffraction method, the density of screw and edge dislocations in the structure under study is measured: their total density exceeds 10{sup 10} cm{sup −2}.

  17. Electron Accumulation Layers in InN Nanocolumns Studied by Raman Scattering

    SciTech Connect

    Gallardo, E.; Lazic, S.; Calleja, J. M.; Agullo-Rueda, F.; Grandal, J.; Sanchez-Garcia, M. A.; Calleja, E.

    2010-01-04

    Inelastic light scattering measurements on single crystal InN nanocolumns grown by plasma-assisted molecular beam epitaxy on both Si(001) and Si(111) substrates reveal the existence of a surface electron accumulation layer in the lateral non-polar sidewalls of the nanocolumns. Small and reversible electron density variations of this surface layer has been induced by chemical treatments of the nanocolumns, which can be accurately determined from the frequency of the LO phonon-plasmon coupled mode L{sub -}. The L{sub -} to E{sub 1}(LO) phonon intensity ratio dependence on the column diameter and the excitation wavelength is interpreted in terms of the inhomogeneous electron distribution in the nanocolumns volume and the presence of strong elastic light scattering by the nanocolumns. The TO modes fail to obey conventional selection rules, a fact that is also observed in GaN nanocolumns.

  18. Angular-dependent Raman study of a- and s-plane InN

    SciTech Connect

    Filintoglou, K.; Katsikini, M. Arvanitidis, J.; Lotsari, A.; Dimitrakopulos, G. P.; Vouroutzis, N.; Ves, S.; Christofilos, D.; Kourouklis, G. A.; Ajagunna, A. O.; Georgakilas, A.; Zoumakis, N.

    2015-02-21

    Angular-dependent polarized Raman spectroscopy was utilized to study nonpolar a-plane (11{sup ¯}20) and semipolar s-plane (101{sup ¯}1) InN epilayers. The intensity dependence of the Raman peaks assigned to the vibrational modes A{sub 1}(TO), E{sub 1}(TO), and E{sub 2}{sup h} on the angle ψ that corresponds to rotation around the growth axis, is very well reproduced by using expressions taking into account the corresponding Raman tensors and the experimental geometry, providing thus a reliable technique towards assessing the sample quality. The s- and a-plane InN epilayers grown on nitridated r-plane sapphire (Al{sub 2}O{sub 3}) exhibit good crystalline quality as deduced from the excellent fitting of the experimental angle-dependent peak intensities to the theoretical expressions as well as from the small width of the Raman peaks. On the contrary, in the case of the s-plane epilayer grown on non-nitridated r-plane sapphire, fitting of the angular dependence is much worse and can be modeled only by considering the presence of two structural modifications, rotated so as their c-axes are almost perpendicular to each other. Although the presence of the second variant is verified by transmission electron and atomic force microscopies, angular dependent Raman spectroscopy offers a non-destructive and quick way for its quantification. Rapid thermal annealing of this sample did not affect the angular dependence of the peak intensities. The shift of the E{sub 1}(TO) and E{sub 2}{sup h} Raman peaks was used for the estimation of the strain state of the samples.

  19. Investigation of the near-surface structures of polar InN films by chemical-state-discriminated hard X-ray photoelectron diffraction

    SciTech Connect

    Yang, A. L.; Yamashita, Y.; Kobata, M.; Yoshikawa, H.; Sakata, O.; Kobayashi, K.; Matsushita, T.; Pis, I.; Imura, M.; Yamaguchi, T.; Nanishi, Y.

    2013-01-21

    Near-surface structures of polar InN films were investigated by laboratory-based hard X-ray photoelectron diffraction (HXPD) with chemical-state-discrimination. HXPD patterns from In 3d{sub 5/2} and N 1s core levels of the In-polar and N-polar InN films were different from each other and compared with the simulation results using a multiple-scattering cluster model. It was found that the near-surface structure of the In-polar InN film was close to the ideal wurtzite structure. On the other hand, on the N-polar InN film, defects-rich surface was formed. In addition, the existence of the In-polar domains was observed in the HXPD patterns.

  20. Structural properties of InN films grown on O-face ZnO(0001) by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Cho, Yong Jin; Brandt, Oliver; Kaganer, Vladimir M.; Ramsteiner, Manfred; Riechert, Henning; Korytov, Maxim; Albrecht, Martin

    2012-04-09

    We study the impact of substrate temperature and layer thickness on the morphological and structural properties of InN films directly grown on O-face ZnO(0001) substrates by plasma-assisted molecular beam epitaxy. With increasing substrate temperature, an interfacial reaction between InN and ZnO takes place that eventually results in the formation of cubic In{sub 2}O{sub 3} and voids. The properties of the InN films, however, are found to be unaffected by this reaction for substrate temperatures less than 550 deg. C. In fact, both the morphological and the structural quality of InN improve with increasing substrate temperature in the range from 350 to 500 deg. C. High quality films with low threading dislocation densities are demonstrated.

  1. Correlation between switching to n-type conductivity and structural defects in highly Mg-doped InN

    SciTech Connect

    Khromov, S.; Persson, P. O. Å.; Monemar, B.; Rosen, J.; Janzén, E.; Darakchieva, V.; Wang, X.; Yoshikawa, A.

    2015-06-08

    The effect of Mg doping on the microstructure of InN epitaxial films in relation to their free-charge carrier properties has been investigated by transmission electron microscopy (TEM) and aberration corrected scanning TEM. We observe a direct correlation between Mg concentration and the formation of stacking faults. The threading dislocation density is found to be independent of Mg concentration. The critical Mg concentration for the on-set of stacking faults formation is determined and found to correlate with the switch from p- to n-type conductivity in InN. Potential mechanisms involving stacking faults and point defect complexes are invoked in order to explain the observed conductivity reversal. Finally, the stacking faults are structurally determined and their role in the reduction of the free electron mobility in highly doped InN:Mg is discussed.

  2. Optical properties of ultra-thin InN layer embedded in InGaN matrix for light emitters

    NASA Astrophysics Data System (ADS)

    Yang, Wei; Wu, Yi-Yang; Liu, Ning-Yang; Liu, Lei; Chen, Zhao; Hu, Xiao-Dong

    2013-04-01

    We theoretically investigate the optical properties of an ultra-thin InN layer embedded in InGaN matrix for light emitters. The peak emission wavelength extends from ultraviolet (374 nm) to green (536 nm) with InN quantum well thickness increasing from 1 monolayer to 2 monolayers, while the overlap of electron-hole wave function remains at a high level (larger than 90%). Increase of In content in InGaN matrix provides a better approach to longer wavelength emission, which only reduces the spontaneous emission rate slightly compared with the case of increasing In content of the conventional InGaN quantum well. Also, the transparency carrier density derived from gain spectrum is of the same order as that in the conventional blue laser diode. Our study provides skillful design on the development of novel structure InN-based light emitting diodes as well as laser diodes.

  3. Surface structure and surface kinetics of InN grown by plasma-assisted atomic layer epitaxy: A HREELS study

    SciTech Connect

    Acharya, Ananta R. E-mail: anantaach@gmail.com; Thoms, Brian D.; Nepal, Neeraj; Eddy, Charles R.

    2015-03-15

    The surface bonding configuration and kinetics of hydrogen desorption from InN grown by plasma-assisted atomic layer epitaxy have been investigated. High resolution electron energy loss spectra exhibited loss peaks assigned to a Fuchs–Kliewer surface phonon, N-N and N-H surface species. The surface N-N vibrations are attributed to surface defects. The observation of N-H but no In-H surface species suggested N-terminated InN. Isothermal desorption data were best fit by the first-order desorption kinetics with an activation energy of (0.88 ± 0.06) eV and pre-exponential factor of (1.5 ± 0.5) × 10{sup 5 }s{sup −1}.

  4. Polarity control and transport properties of Mg-doped (0001) InN by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Choi, Soojeong; Wu Feng; Bierwagen, Oliver; Speck, James S.

    2013-05-15

    The authors report on the plasma-assisted molecular beam epitaxy growth and carrier transport of Mg-doped In-face (0001) InN. The 1.2 {mu}m thick InN films were grown on GaN:Fe templates under metal rich conditions with Mg concentration from 1 Multiplication-Sign 10{sup 17}/cm{sup 3} to 3 Multiplication-Sign 10{sup 20}/cm{sup 3}. A morphological transition, associated with the formation of V-shape polarity inversion domains, was observed at Mg concentration over 7 Multiplication-Sign 10{sup 19}/cm{sup 3} by atomic force microscopy and transmission electron microscopy. Seebeck measurements indicated p-type conductivity for Mg-concentrations from 9 Multiplication-Sign 10{sup 17}/cm{sup 3} to 7 Multiplication-Sign 10{sup 19}/cm{sup 3}, i.e., as it exceeded the compensating (unintentional) donor concentration.

  5. First-principles calculations for AlN, GaN, and InN: Bulk and alloy properties

    SciTech Connect

    Wright, A.F.; Nelson, J.S.

    1995-02-01

    First-principles density-functional calculations utilizing ab initio pseudopotentials and plane-wave expansions are used to determine lattice parameters, bulk moduli, and band structures for AlN, GaN and InN. It is found that large numbers of plane waves are necessary to resolve the nitrogen 2p wave functions and that explicit treatment of the gallium 3d and indium 4d electrons is important for an accurate description of GaN and InN. Several properties of ternary zinc-blende alloys are determined including their bond-length and bond-angle relaxation and their energy-gap bowing parameters. The similarity of the calculated zinc-blende and wurtzite direct gaps also allows estimates to be made of the energy gap versus composition for wurtzite alloys.

  6. Time-integrated photoluminescence and pump-probe reflection spectroscopy of Si doped InN thin films

    SciTech Connect

    Mohanta, Antaryami; Jang, Der-Jun Wang, Ming-Sung; Tu, L. W.

    2014-01-28

    Temperature and excitation power dependent time-integrated photoluminescence of Si doped InN thin films are investigated. Photoluminescence (PL) spectra at low temperatures are described by single emission peak ensued due to “free-to-bound” recombination; whereas PL spectra at higher temperatures above 150 K are characterized by both “band-to-band” and “free-to-bound” transition. Carrier dynamics of Si doped InN thin films is studied using pump-probe reflection spectroscopy at room temperature. The hot electron cooling process is well described by electron-electron scattering. The dependence of the hot electron cooling rate on total electron density shows sublinear to linear behavior with increase of background electron density. The variation of the carrier recombination lifetime with total electron density implicates the dominance of the defect-related nonradiative recombination channel over other recombination processes.

  7. X-ray diffraction study of A- plane non-polar InN epilayer grown by MOCVD

    NASA Astrophysics Data System (ADS)

    Moret, Matthieu; Briot, Olivier; Gil, Bernard

    2015-03-01

    Strong polarisation-induced electric fields in C-plane oriented nitrides semiconductor layers reduce the performance of devices. Eliminating the polarization fields can be achieved by growing nitrides along non polar direction. We have grown non polar A-plane oriented InN on R-plane (1‾102) nitridated sapphire substrate by MOCVD. We have studied the structural anisotropy observed in these layers by analyzing High Resolution XRay Diffraction rocking curve (RC) experiments as a function of the in-plane beam orientation. A-plane InN epilayer have a unique epitaxial relationship on R-Plane sapphire and show a strong structural anisotropy. Full width at half maximum (FWHM) of the InN(11‾20) XRD RC values are contained between 44 and 81 Arcmin. FWHM is smaller when the diffraction occurs along the [0001] and the largest FWHM values, of the (11‾20) RC, are obtained when the diffraction occurs along the [1‾100] in-plane direction. Atomic Force Microscopy imaging revealed morphologies with well organized crystallites. The grains are structured along a unique crystallographic orientation of InN, leading to larger domains in this direction. This structural anisotropy can be, in first approximation, attributed to the difference in the domain sizes observed. XRD reciprocal space mappings (RSM) were performed in asymmetrical configuration on (13‾40) and (2‾202) diffraction plane. RSM are measured with a beam orientation corresponding to a maximal and a minimal width of the (11‾20) Rocking curves, respectively. A simple theoretical model is exposed to interpret the RSM. We concluded that the dominant contribution to the anisotropy is due to the scattering coherence length anisotropy present in our samples.

  8. R&W Club Frederick Hosts 4th Annual Golf Tournament Benefiting The Children’s Inn at NIH | Poster

    Cancer.gov

    The R&W Club Frederick’s 4th Annual Golf Tournament to benefit the Children’s Inn at NIH teed off on time despite cloudy weather and scattered showers. Employees from NCI at Frederick, the main NIH campus, and Leidos Biomed, along with family and friends, came to enjoy an afternoon at the beautiful Maryland National Golf Club in Middletown and to support a wonderful charity.

  9. R&W Club Frederick Hosts Second Annual Golf Tourney for The Children’s Inn | Poster

    Cancer.gov

    By Carolynne Keenan, Contributing Writer On Sept. 8, more than 40 NCI at Frederick and Leidos Biomedical Research employees, along with family and friends, swapped work clothes for golf gear at Maryland National Golf Club in Middletown. The golfers didn’t just play for fun; they participated in the second annual R&W Club Frederick Golf Tournament to support The Children’s Inn at NIH.

  10. Vertically integrated (Ga, In)N nanostructures for future single photon emitters operating in the telecommunication wavelength range

    NASA Astrophysics Data System (ADS)

    Winden, A.; Mikulics, M.; Grützmacher, D.; Hardtdegen, H.

    2013-10-01

    Important technological steps are discussed and realized for future room-temperature operation of III-nitride single photon emitters. First, the growth technology of positioned single pyramidal InN nanostructures capped by Mg-doped GaN is presented. The optimization of their optical characteristics towards narrowband emission in the telecommunication wavelength range is demonstrated. In addition, a device concept and technology was developed so that the nanostructures became singularly addressable. It was found that the nanopyramids emit in the telecommunication wavelength range if their size is chosen appropriately. A p-GaN contacting layer was successfully produced as a cap to the InN pyramids and the top p-contact was achievable using an intrinsically conductive polymer PEDOT:PSS, allowing a 25% increase in light transmittance compared to standard Ni/Au contact technology. Single nanopyramids were successfully integrated into a high-frequency device layout. These decisive technology steps provide a promising route to electrically driven and room-temperature operating InN based single photon emitters in the telecommunication wavelength range.

  11. Superconductivity of Ca2 InN with a layered structure embedding an anionic indium chain array

    NASA Astrophysics Data System (ADS)

    Jeong, Sehoon; Matsuishi, Satoru; Lee, Kimoon; Toda, Yoshitake; Wng Kim, Sung; Hosono, Hideo

    2014-05-01

    We report the emergence of superconductivity in Ca2InN consisting of a two-dimensional (2D) array of zigzag indium chains embedded between Ca2N layers. A sudden drop of resistivity and a specific heat (Cp) jump attributed to the superconducting transition were observed at 0.6 K. The Sommerfeld coefficient γ = 4.24 mJ mol-1K-2 and Debye temperature ΘD = 322 K were determined from the Cp of the normal conducting state and the superconducting volume fraction was estimated to be ˜80% from the Cp jump, assuming a BCS-type weak coupling. Density functional theory calculations demonstrated that the electronic bands near the Fermi level (EF) are mainly derived from In 5p orbitals with π and σ bonding states and the Fermi surface is composed of cylindrical parts, corresponding to the quasi-2D electronic state of the In-chain array. By integrating the projected density of states of the In-p component up to EF, a valence electron population of ˜1.6 electrons/In was calculated, indicating that partially anionic state of In. The In 3d binding energies observed in Ca2InN by x-ray photoemission spectroscopy were negatively shifted from that in In metal. The superconductivity of Ca2InN is associated with the p-p bonding states of the anionic In layer.

  12. Current transport in W and WSI{sub x} ohmic contacts to InGaN and InN

    SciTech Connect

    Vartuli, C.B.; Pearton, S.J.; Abernathy, C.R.

    1997-10-01

    The temperature dependence of the specific contact resistance of W and WSi{sub 0.44} contacts on n{sup +} In{sub 0.65}Ga{sub 0.35}N and InN was measured in the range -50 {degrees}C to 125 {degrees}C. The results were compared to theoretical values for different conduction mechanisms, to further elucidate the conduction mechanism in these contact schemes for all but as-deposited metal to InN where thermionic emission appears to be the dominant mechanism. The contacts were found to produce low specific resistance ohmic contacts to InGaN at room temperature, e{sup c} {approximately} 10{sup -7} {Omega} {center_dot} cm{sup 2} for W and e{sub c} of 4x 10{sup -7} {Omega} {center_dot} cm{sup 2} for WSi{sub x}. InN metallized with W produced ohmic contacts with e{sub c} {approximately} 10{sup -7} {Omega} {center_dot} cm{sup 2} and e{sub c} {approximately} 10{sup -6} {Omega} {center_dot} cm{sup 2} for WSi{sub x} at room temperature.

  13. Vertically integrated (Ga, In)N nanostructures for future single photon emitters operating in the telecommunication wavelength range.

    PubMed

    Winden, A; Mikulics, M; Grützmacher, D; Hardtdegen, H

    2013-10-11

    Important technological steps are discussed and realized for future room-temperature operation of III-nitride single photon emitters. First, the growth technology of positioned single pyramidal InN nanostructures capped by Mg-doped GaN is presented. The optimization of their optical characteristics towards narrowband emission in the telecommunication wavelength range is demonstrated. In addition, a device concept and technology was developed so that the nanostructures became singularly addressable. It was found that the nanopyramids emit in the telecommunication wavelength range if their size is chosen appropriately. A p-GaN contacting layer was successfully produced as a cap to the InN pyramids and the top p-contact was achievable using an intrinsically conductive polymer PEDOT:PSS, allowing a 25% increase in light transmittance compared to standard Ni/Au contact technology. Single nanopyramids were successfully integrated into a high-frequency device layout. These decisive technology steps provide a promising route to electrically driven and room-temperature operating InN based single photon emitters in the telecommunication wavelength range.

  14. High-quality cubic and hexagonal InN crystals studied by micro-Raman scattering and electron backscatter diffraction

    NASA Astrophysics Data System (ADS)

    Kamimura, Jumpei; Ramsteiner, Manfred; Jahn, Uwe; Lu, Cheng-Ying James; Kikuchi, Akihiko; Kishino, Katsumi; Riechert, Henning

    2016-04-01

    Large InN microcrystals grown by molecular beam epitaxy are investigated by micro-Raman spectroscopy and electron backscatter diffraction (EBSD). High-quality (phonon linewidths between 1.5 and 2 cm-1) cubic and hexagonal crystals are identified with Raman mapping by the observation of the respective characteristic phonon modes. The unexpected occurrence of metastable cubic InN crystals is confirmed by EBSD measurements. The cubic microcrystals are revealed by EBSD to be single-crystalline and to exhibit  <1 1 1>  orientation. The transverse (TO) and longitudinal-optical (LO) zone-center phonon frequencies of cubic InN are found to be 463 and 584 cm-1, respectively. The bulk carrier density in the microcrystals lies in the range of 2-3  ×  1017 cm-3 as determined by the analysis of LO phonon-plasmon-coupled modes in the Raman spectra.

  15. Elucidating the optical properties of MoTe2/InN heterostructures for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Rocha, Alexandre; Villegas, Cesar E. P.

    2015-03-01

    Recently, two-dimensional (2D) atom-thick hexagonal crystals have drawn both experimental and theoretical interest due to their fundamental properties and potential applicability in electronics and optoelectronics. While most studies are focused on 2D crystals with gap in the visible electromagnetic spectrum, the ones with gaps in the near infrared region have not been explored yet. Motivated by this and considering the individual properties of transition metal dichalcogenides and group III-V compounds, we carry out density functional theory (DFT) calculations combine with the GW-Bethe-Salpeter (GW-BSE) methodology to study the optical properties and the power conversion efficiency of MoTe2/InN heterostructures. First, we study the geometric and electronic structure of three heterostructures based on different stacking. Secondly, we use the GW-BSE methodology to study the optical spectrum and estimate the power conversion efficiency of the device. Our results indicates that the photoexcited exciton are originated in the range of 1.12 to 1.5 eV. In addition, we estimate the exciton recombination time finding values in the nanosecond range. Finally, we estimated the short-circuit current and power conversion efficiency of the 2 nm thick device. The Authors thank FAPESP for financial support.

  16. Hole transport and photoluminescence in Mg-doped InN

    SciTech Connect

    Miller, N.; Ager III, J. W.; Smith III, H. M.; Mayer, M. A.; Yu, K. M.; Haller, E. E.; Walukiewicz, W.; Schaff, W. J.; Gallinat, C.; Koblmuller, G.; Speck, J. S.

    2010-03-24

    Hole conductivity and photoluminescence were studied in Mg-doped InN films grown by molecular beam epitaxy. Because surface electron accumulation interferes with carrier type determination by electrical measurements, the nature of the majority carriers in the bulk of the films was determined using thermopower measurements. Mg concentrations in a"window" from ca. 3 x 1017 to 1 x 1019 cm-3 produce hole-conducting, p-type films as evidenced by a positive Seebeck coecient. This conclusion is supported by electrolyte-based capacitance voltage measurements and by changes in the overall mobility observed by Hall effect, both of which are consistent with a change from surface accumulation on an n-type film to surface inversion on a p-type film. The observed Seebeck coefficients are understood in terms of a parallel conduction model with contributions from surface and bulk regions. In partially compensated films with Mg concentrations below the window region, two peaks are observed in photoluminescence at 672 meV and at 603 meV. They are attributed to band-to-band and band-to-acceptor transitions, respectively, and an acceptor binding energy of ~;;70 meV is deduced. In hole-conducting films with Mg concentrations in the window region, no photoluminescence is observed; this is attributed to electron trapping by deep states which are empty for Fermi levels close to the valence band edge.

  17. Electrical transport properties of single undoped and n-type doped InN nanowires.

    PubMed

    Richter, T; Lüth, H; Schäpers, Th; Meijers, R; Jeganathan, K; Estévez Hernández, S; Calarco, R; Marso, M

    2009-10-01

    Electrical transport properties of undoped and n-type doped InN nanowires grown by molecular beam epitaxy were studied by current-voltage and back-gate field-effect transistor measurements. The current-voltage characteristics show ohmic behavior in the temperature range between 4 and 300 K. Down to about 120 K a linear decrease in resistance with temperature is observed. The investigation of a large number of nanowires revealed for undoped as well as doped wires an approximately linear relation between the normalized conductance and diameter for wires with a diameter below 100 nm. This shows that the main conduction takes place in the tubular surface accumulation layer of the wires. In contrast, for doped wires with a diameter larger than 100 nm a quadratic dependence of conduction on the diameter was found, which is attributed to bulk conductance as the main contribution. The successful doping of the wires is confirmed by an enhanced conduction and by the results of the back-gate field-effect transistor measurements. PMID:19738304

  18. Evaluation of testing strategies for the radiation tolerant ATLAS n +-in-n pixel sensor

    NASA Astrophysics Data System (ADS)

    Klaiber-Lodewigs, Jonas M.; Atlas Pixel Collaboration

    2003-10-01

    The development of particle tracker systems for high fluence environments in new high-energy physics experiments raises new challenges for the development, manufacturing and reliable testing of radiation tolerant components. The ATLAS pixel detector for use at the LHC, CERN, is designed to cover an active sensor area of 1.8 m2 with 1.1×10 8 read-out channels usable for a particle fluence up to 10 15 cm-2 ( 1 MeV neutron equivalent) and an ionization dose up to 500 kGy of mainly charged hadron radiation. To cope with such a harsh environment the ATLAS Pixel Collaboration has developed a radiation hard n +-in-n silicon pixel cell design with a standard cell size of 50×400 μm2. Using this design on an oxygenated silicon substrate, sensor production has started in 2001. This contribution describes results gained during the development of testing procedures of the ATLAS pixel sensor and evaluates quality assurance procedures regarding their relevance for detector operation in the ATLAS experiment. The specific set of tests discussed in detail measures sensor depletion, interface generation velocity, p-spray dose and biasing by punch-through mechanism and is designed to give insights into effects of irradiation with ionizing particles.

  19. Molten salt-based growth of bulk GaN and InN for substrates.

    SciTech Connect

    Waldrip, Karen Elizabeth

    2007-08-01

    An atmospheric pressure approach to growth of bulk group III-nitrides is outlined. Native III-nitride substrates for optoelectronic and high power, high frequency electronics are desirable to enhance performance and reliability of these devices; currently, these materials are available in research quantities only for GaN, and are unavailable in the case of InN. The thermodynamics and kinetics of the reactions associated with traditional crystal growth techniques place these activities on the extreme edges of experimental physics. The novel techniques described herein rely on the production of the nitride precursor (N{sup 3-}) by chemical and/or electrochemical methods in a molten halide salt. This nitride ion is then reacted with group III metals in such a manner as to form the bulk nitride material. The work performed during the period of funding (February 2006-September 2006) focused on establishing that mass transport of GaN occurs in molten LiCl, the construction of a larger diameter electrochemical cell, the design, modification, and installation of a made-to-order glove box (required for handling very hygroscopic LiCl), and the feasibility of using room temperature molten salts to perform nitride chemistry experiments.

  20. Molten Salt-Based Growth of Bulk GaN and InN for Substrates

    SciTech Connect

    Waldrip, Karen Elizabeth; Tsao, Jeffrey Yeenien; Kerley, Thomas M.

    2006-09-01

    An atmospheric pressure approach to growth of bulk group III-nitrides is outlined. Native III-nitride substrates for optoelectronic and high power, high frequency electronics are desirable to enhance performance and reliability of these devices; currently, these materials are available in research quantities only for GaN, and are unavailable in the case of InN. The thermodynamics and kinetics of the reactions associated with traditional crystal growth techniques place these activities on the extreme edges of experimental physics. The technique described herein relies on the production of the nitride precursor (N3-) by chemical and/or electrochemical methods in a molten halide salt. This nitride ion is then reacted with group III metals in such a manner as to form the bulk nitride material. The work performed during the period of funding (July 2004-September 2005) focused on the initial measurement of the solubility of GaN in molten LiCl as a function of temperature, the construction of electrochemical cells, the modification of a commercial glove box (required for handling very hygroscopic LiCl), and on securing intellectual property for the technique.

  1. risk factor Inn (INNrisk) - transdisciplinary analysis of the 2005 flood in the province of Tyrol, Austria

    NASA Astrophysics Data System (ADS)

    Kleewein, Klaus; Pfurtscheller, Clemens; Borsdorf, Axel

    2010-05-01

    The transdisciplinary project INNrisk, in collaboration with public risk and disaster management, investigates the severe floods of 22nd and 23rd of August, 2005, and their effects within the federal province of Tyrol. The inundation and accompanying processes (e.g. debris flows, log jams, underwashing of infrastructure) caused by the river Inn and its tributaries created a dangerous situation for Tyrol. The overall economic loss of direct assets is said to amount to ca. 500 million Euros. Climate change has basically been causing a statistical increase of damaging floods within the Alpine Space in recent decades while increasing vulnerability at the same time. The expansion of settlements is one factor in the threat to large numbers of people and growing economic losses. However, the disasters of the last decade provide an opportunity for analysing the flood process in terms of natural-science and geographical aspects as well as in terms of economic and statistical ones. This should lead to a better understanding of triggers and effects in those areas where humans are active and form the basis for mitigation and adaptation strategies. The results of such analyses represent valuable information for public risk and disaster management, particularly in presenting the effects on public and private households. The INNrisk project primarily aims to assess the framework conditions in systemic-legal terms and to analyse human actions during the floods in relation to various plans and the damage potentials resulting from them. The assessed losses depend to a great extent on the actions taken during the emergency and on flood operations by the public emergency management and local fire departments, which are in charge of floods and related processes in the case of Austria. Assessment will be carried out by analysing a database of series of human actions for the duration of the emergeny and increased risk. The project also strives to arrive at a macro- and mesoeconomic

  2. Beaulieu-Boycott-Innes syndrome: an intellectual disability syndrome with characteristic facies.

    PubMed

    Casey, Jillian; Jenkinson, Allan; Magee, Alex; Ennis, Sean; Monavari, Ahmad; Green, Andrew; Lynch, Sally A; Crushell, Ellen; Hughes, Joanne

    2016-10-01

    We report a female child from an Irish Traveller family presenting with severe intellectual disability, dysmorphic features, renal anomalies, dental caries and cyclical vomiting. Current health issues include global developmental delay, mild concentric left ventricular hypertrophy, dental malocclusion and caries and a single duplex left kidney. The proband and her mother also have multiple epiphyseal dysplasia. Whole-exome sequencing was performed to identify the underlying genetic cause. DNA from the proband was enriched with the Agilent Sure Select v5 Exon array and sequenced on an Illumina HiSeq. Rare homozygous variants were prioritized. Whole-exome sequencing identified three linked homozygous missense variants in THOC6 (c.298T>A, p.Trp100Arg; c.700G>C, p.Val234Leu; c.824G>A, p.Gly275Asp) as the likely cause of this child's intellectual disability syndrome, resulting in a molecular diagnosis of Beaulieu-Boycott-Innes syndrome (BBIS). This is the first report of BBIS in Europe. BBIS has been reported previously in two Hutterite families and one Saudi family. A review of all patients to date shows a relatively homogenous phenotype. Core clinical features include low birth weight with subsequent growth failure, short stature, intellectual disability with language delay, characteristic facies, renal anomalies and dental malocclusion with caries. Some patients also have cardiac defects. All patients show characteristic dysmorphic facial features including a tall forehead with high anterior hairline and deep-set eyes with upslanting palpebral fissures. The coexistence of intellectual disability together with these characteristic facies should provide a diagnostic clue for BBIS during patient evaluation. PMID:27295358

  3. Beaulieu-Boycott-Innes syndrome: an intellectual disability syndrome with characteristic facies.

    PubMed

    Casey, Jillian; Jenkinson, Allan; Magee, Alex; Ennis, Sean; Monavari, Ahmad; Green, Andrew; Lynch, Sally A; Crushell, Ellen; Hughes, Joanne

    2016-10-01

    We report a female child from an Irish Traveller family presenting with severe intellectual disability, dysmorphic features, renal anomalies, dental caries and cyclical vomiting. Current health issues include global developmental delay, mild concentric left ventricular hypertrophy, dental malocclusion and caries and a single duplex left kidney. The proband and her mother also have multiple epiphyseal dysplasia. Whole-exome sequencing was performed to identify the underlying genetic cause. DNA from the proband was enriched with the Agilent Sure Select v5 Exon array and sequenced on an Illumina HiSeq. Rare homozygous variants were prioritized. Whole-exome sequencing identified three linked homozygous missense variants in THOC6 (c.298T>A, p.Trp100Arg; c.700G>C, p.Val234Leu; c.824G>A, p.Gly275Asp) as the likely cause of this child's intellectual disability syndrome, resulting in a molecular diagnosis of Beaulieu-Boycott-Innes syndrome (BBIS). This is the first report of BBIS in Europe. BBIS has been reported previously in two Hutterite families and one Saudi family. A review of all patients to date shows a relatively homogenous phenotype. Core clinical features include low birth weight with subsequent growth failure, short stature, intellectual disability with language delay, characteristic facies, renal anomalies and dental malocclusion with caries. Some patients also have cardiac defects. All patients show characteristic dysmorphic facial features including a tall forehead with high anterior hairline and deep-set eyes with upslanting palpebral fissures. The coexistence of intellectual disability together with these characteristic facies should provide a diagnostic clue for BBIS during patient evaluation.

  4. Formation of InN atomic-size wires by simple N adsorption on the In/Si(111)-(4 × 1) surface

    NASA Astrophysics Data System (ADS)

    Guerrero-Sánchez, J.; Takeuchi, Noboru

    2016-11-01

    We have carried out first principles total energy calculations to study the formation of InN atomic-size wires on the In/Si(111)-(4 × 1) surface. In its most favorable adsorption site, a single N atom forms InN arrangements. The deposit of 0.25 monolayers (MLs) of N atoms, result in the breaking of one of the original In chains and the formation of an InN atomic size wire. Increasing the coverage up to 0.5 ML of N atoms results in the formation of two of those wires. Calculated surface formation energies show that for N-poor conditions the most stable configuration is the original In/Si(111)-(4 × 1) surface with no N atoms. Increasing the N content, and in a reduced range of chemical potential, the formation of an InN wire is energetically favorable. Instead, from intermediate to N-rich conditions, two InN atomic wires are more stable. Projected density of states calculations have shown a trend to form covalent bonds between the Insbnd p and Nsbnd p orbitals in these stable models.

  5. Enhancing structural transition by carrier and quantum confinement: Stabilization of cubic InN quantum dots by Mn incorporation

    SciTech Connect

    Meng, Xiuqing; Wu, Fengmin; Chen, Zhanghui; Li, Shu-Shen; Chen, Zhuo; Li, Jingbo E-mail: swei@nrel.gov; Wu, Junqiao; Wei, Su-Huai E-mail: swei@nrel.gov

    2013-12-16

    We demonstrate in this work controllable synthesis of cubic InN nanocrystals through Mn doping. We show that the pristine nanocrystal has the wurtzite structure, but can be converted into the zinc-blende (ZB) structure when it is doped with Mn. Our first-principles calculations show that the phase transition is caused by the stronger p-d coupling between the host p valence state and the impurity d level in the ZB structure, which makes the hole generation in the ZB structure easier. Quantum confinement in the nanocrystals further enhanced this effect. This observation lays an important foundation for defects control of crystal phases.

  6. Reduction of electron accumulation at InN(0001) surfaces via saturation of surface states by potassium and oxygen as donor- or acceptor-type adsorbates

    SciTech Connect

    Eisenhardt, A.; Reiß, S.; Krischok, S. Himmerlich, M.

    2014-01-28

    The influence of selected donor- and acceptor-type adsorbates on the electronic properties of InN(0001) surfaces is investigated implementing in-situ photoelectron spectroscopy. The changes in work function, surface band alignment, and chemical bond configurations are characterized during deposition of potassium and exposure to oxygen. Although an expected opponent charge transfer characteristic is observed with potassium donating its free electron to InN, while dissociated oxygen species extract partial charge from the substrate, a reduction of the surface electron accumulation occurs in both cases. This observation can be explained by adsorbate-induced saturation of free dangling bonds at the InN resulting in the disappearance of surface states, which initially pin the Fermi level and induce downward band bending.

  7. InGaN nanowires with high InN molar fraction: growth, structural and optical properties.

    PubMed

    Zhang, Xin; Lourenço-Martins, Hugo; Meuret, Sophie; Kociak, Mathieu; Haas, Benedikt; Rouvière, Jean-Luc; Jouneau, Pierre-Henri; Bougerol, Catherine; Auzelle, T; Jalabert, D; Biquard, Xavier; Gayral, Bruno; Daudin, Bruno

    2016-05-13

    The structural and optical properties of axial GaN/InGaN/GaN nanowire heterostructures with high InN molar fractions grown by molecular beam epitaxy have been studied at the nanoscale by a combination of electron microscopy, extended x-ray absorption fine structure and nano-cathodoluminescence techniques. InN molar fractions up to 50% have been successfully incorporated without extended defects, as evidence of nanowire potentialities for practical device realisation in such a composition range. Taking advantage of the N-polarity of the self-nucleated GaN NWs grown by molecular beam epitaxy on Si(111), the N-polar InGaN stability temperature diagram has been experimentally determined and found to extend to a higher temperature than its metal-polar counterpart. Furthermore, annealing of GaN-capped InGaN NWs up to 800 °C has been found to result in a 20 times increase of photoluminescence intensity, which is assigned to point defect curing.

  8. Wine Valley Inn: A mineral water spa in Calistoga, California. Geothermal-energy-system conceptual design and economic feasibility

    SciTech Connect

    Not Available

    1981-10-26

    The purpose of this study is to determine the engineering and economic feasibility for utilizing geothermal energy for air conditioning and service water heating at the Wine Valley Inn, a mineral water spa in Calistoga, California. The study evaluates heating, ventilating, air conditioning and water heating systems suitable for direct heat geothermal application. Due to the excellent geothermal temperatures available at this site, the mechanics and economics of a geothermally powered chilled water cooling system are evaluated. The Wine Valley Inn has the resource potential to have one of the few totally geothermal powered air conditioning and water heating systems in the world. This total concept is completely developed. A water plan was prepared to determine the quantity of water required for fresh water well development based on the special requirements of the project. An economic evaluation of the system is included to justify the added capital investment needed to build the geothermally powered mineral spa. Energy payback calculations are presented. A thermal cascade system is proposed to direct the geothermal water through the energy system to first power the chiller, then the space heating system, domestic hot water, the two spas and finally to heat the swimming pool. The Energy Management strategy required to automatically control this cascade process using industrial quality micro-processor equipment is described. Energy Management controls are selected to keep equipment sizing at a minimum, pump only the amount of geothermal water needed and be self balancing.

  9. The daytime boundary layer in the Inn Valley - A model evaluation study with high-quality turbulence measurements

    NASA Astrophysics Data System (ADS)

    Goger, Brigitta; Rotach, Mathias W.; Gohm, Alexander; Fuhrer, Oliver; Stiperski, Ivana

    2016-04-01

    Atmospheric processes associated with complex terrain include various phenomena on the meso- and microscale, which contribute significantly to the local weather in mountainous areas of the Earth. One of the most prominent and well-known boundary-layer phenomena in mountainous terrain is the daytime valley wind circulation, which is very pronounced on clear-sky days with weak synoptic forcing. We use several chosen "valley wind days" in the Inn Valley, Austria, as case studies for the evaluation of the performance of the NWP model COSMO on a horizontal resolution of 1.1 km with a focus on boundary-layer processes and turbulent exchange. The overall goal is to evaluate the model setup and to investigate whether the model's physics schemes (initially developed for horizontally homogeneous and flat surroundings) are suitable for truly complex terrain. We evaluate the model by using measurements from the so-called "i-Box" located in the Inn Valley. The i-Box consists of six core sites that are located at representative locations in the Inn Valley, and two remote sensing systems (wind Lidar and HATPRO passive T/RH profiler) in the city of Innsbruck. The long-term data set provides a data pool of high-resolution velocity variances, turbulence variables, radiation, soil moisture, and vertical profiles of temperature, humidity, and wind in the lower troposphere, which allows a process-oriented analysis. A special focus is laid on the daytime valley boundary layer and its interaction with the developing up-valley wind. Vertical cross-sections show that the valley wind has an asymmetric structure, hence, the i-Box stations show a high spatial variability. While the station on the valley bottom and on the south-facing slope are clearly under the strong influence of the valley wind, the two stations on the north-facing slope are rather dominated by slope flows. We find that the valley wind has a strong (indirect) influence on the development of the local turbulence kinetic

  10. Study of structural properties of cubic InN films on GaAs(001) substrates by molecular beam epitaxy and migration enhanced epitaxy

    SciTech Connect

    Casallas-Moreno, Y. L.; Perez-Caro, M.; Gallardo-Hernandez, S.; Ramirez-Lopez, M.; Martinez-Velis, I.; Lopez-Lopez, M.; Escobosa-Echavarria, A.

    2013-06-07

    InN epitaxial films with cubic phase were grown by rf-plasma-assisted molecular beam epitaxy (RF-MBE) on GaAs(001) substrates employing two methods: migration-enhanced epitaxy (MEE) and conventional MBE technique. The films were synthesized at different growth temperatures ranging from 490 to 550 Degree-Sign C, and different In beam fluxes (BEP{sub In}) ranging from 5.9 Multiplication-Sign 10{sup -7} to 9.7 Multiplication-Sign 10{sup -7} Torr. We found the optimum conditions for the nucleation of the cubic phase of the InN using a buffer composed of several thin layers, according to reflection high-energy electron diffraction (RHEED) patterns. Crystallographic analysis by high resolution X-ray diffraction (HR-XRD) and RHEED confirmed the growth of c-InN by the two methods. We achieved with the MEE method a higher crystal quality and higher cubic phase purity. The ratio of cubic to hexagonal components in InN films was estimated from the ratio of the integrated X-ray diffraction intensities of the cubic (002) and hexagonal (1011) planes measured by X-ray reciprocal space mapping (RSM). For MEE samples, the cubic phase of InN increases employing higher In beam fluxes and higher growth temperatures. We have obtained a cubic purity phase of 96.4% for a film grown at 510 Degree-Sign C by MEE.

  11. Influence of In-N Clusters on Band Gap Energy of Dilute Nitride In x Ga1-x N y As1-y

    NASA Astrophysics Data System (ADS)

    Zhao, Chuan-Zhen; Guo, Heng-Fei; Chen, Li-Ying; Tang, Chun-Xiao; Lu, Ke-Qing

    2016-05-01

    The In-N clusters form in the dilute nitride InxGa1-xNyAs1-y alloys after annealing. It is found that the formation of the In-N clusters not only raises the N levels lying above the conduction band minimum (CBM) of InGaAs, but also raises the N levels below the CBM of InGaAs, leading to the variation of the impurity-host interaction. The blueshift of the band gap energy is relative to the variation of the impurity-host interaction. In order to describe the blueshift of the band gap energy due to the formation of the In-N clusters, a model is developed. It is found that the model can describe the blueshift of the band gap energy well. In addition, it is found the blueshift of the band gap energy due to the atom interdiffusion at the interface can be larger than that due to the formation of the In-N clusters. Supported by the National Natural Science Foundation of China under Grant No. 61504094, Tinjin Research Program of Application Foundation and Advanced Technology under No. 15JCYBJC16300, and Tianjin City High School Science and Technology Fund Planning Project No. 20120609

  12. Influence of In-N Clusters on Band Gap Energy of Dilute Nitride In x Ga1‑x N y As1‑y

    NASA Astrophysics Data System (ADS)

    Zhao, Chuan-Zhen; Guo, Heng-Fei; Chen, Li-Ying; Tang, Chun-Xiao; Lu, Ke-Qing

    2016-05-01

    The In-N clusters form in the dilute nitride InxGa1‑xNyAs1‑y alloys after annealing. It is found that the formation of the In-N clusters not only raises the N levels lying above the conduction band minimum (CBM) of InGaAs, but also raises the N levels below the CBM of InGaAs, leading to the variation of the impurity-host interaction. The blueshift of the band gap energy is relative to the variation of the impurity-host interaction. In order to describe the blueshift of the band gap energy due to the formation of the In-N clusters, a model is developed. It is found that the model can describe the blueshift of the band gap energy well. In addition, it is found the blueshift of the band gap energy due to the atom interdiffusion at the interface can be larger than that due to the formation of the In-N clusters. Supported by the National Natural Science Foundation of China under Grant No. 61504094, Tinjin Research Program of Application Foundation and Advanced Technology under No. 15JCYBJC16300, and Tianjin City High School Science and Technology Fund Planning Project No. 20120609

  13. Electronic and thermoelectric properties of InN studied using ab initio density functional theory and Boltzmann transport calculations

    NASA Astrophysics Data System (ADS)

    Borges, P. D.; Scolfaro, L.

    2014-12-01

    The thermoelectric properties of indium nitride in the most stable wurtzite phase (w-InN) as a function of electron and hole concentrations and temperature were studied by solving the semiclassical Boltzmann transport equations in conjunction with ab initio electronic structure calculations, within Density Functional Theory. Based on maximally localized Wannier function basis set and the ab initio band energies, results for the Seebeck coefficient are presented and compared with available experimental data for n-type as well as p-type systems. Also, theoretical results for electric conductivity and power factor are presented. Most cases showed good agreement between the calculated properties and experimental data for w-InN unintentionally and p-type doped with magnesium. Our predictions for temperature and concentration dependences of electrical conductivity and power factor revealed a promising use of InN for intermediate and high temperature thermoelectric applications. The rigid band approach and constant scattering time approximation were utilized in the calculations.

  14. Comparison of dry-etch techniques for GaN, InN, and AlN

    SciTech Connect

    Shul, R.J.; Vawter, G.A.; Willison, C.G.; Bridges, M.M.; Lee, J.W.; Pearton, S.J.; Abernathy, C.R.

    1997-12-01

    FABRICATION OF GROUP III NITRIDE DEVICES RELIES ON THE ABILITY TO PATTERN FEATURES TO DEPTHS RANGING FROM 1000 A TO {gt} 5 MICRONS WITH ANISOTROPIC PROFILES, SMOOTH MORPHOLOGIES, SELECTIVE ETCHING OF ONE MATERIAL OVER ANOTHER, AND A LOW DEGREE OF PLASMA INDUCED DAMAGE. IN THIS STUDY, GAN ETCH RATES AND ETCH PROFILES ARE COMPARED USING REACTIVE ION ETCH (RIE), REACTIVE ION BEAM ETCHING (RIBE), ELECTRON CYCLOTRON RESONANCE (ECR), AND INDUCTIVELY COUPLED PLASMA (ICP) ETCH SYSTEMS. RIE YIELDED THE SLOWEST ETCH RATES AND SLOPED ETCH PROFILES DESPITE DC-BIASES {gt} -900 V. ECR and ICP etching yielded the highest rates with anisotropic profiles due to their high plasma flux and the ability to control ion energies independently of plasma density. RIBE etch results also showed anisotropic profiles with slower etch rates than either ECR or ICP possibly due to lower ion flux. InN and AlN etch characteristics are also compared using ICP and RIBE.

  15. Electronic and thermoelectric properties of InN studied using ab initio density functional theory and Boltzmann transport calculations

    SciTech Connect

    Borges, P. D. E-mail: lscolfaro@txstate.edu; Scolfaro, L. E-mail: lscolfaro@txstate.edu

    2014-12-14

    The thermoelectric properties of indium nitride in the most stable wurtzite phase (w-InN) as a function of electron and hole concentrations and temperature were studied by solving the semiclassical Boltzmann transport equations in conjunction with ab initio electronic structure calculations, within Density Functional Theory. Based on maximally localized Wannier function basis set and the ab initio band energies, results for the Seebeck coefficient are presented and compared with available experimental data for n-type as well as p-type systems. Also, theoretical results for electric conductivity and power factor are presented. Most cases showed good agreement between the calculated properties and experimental data for w-InN unintentionally and p-type doped with magnesium. Our predictions for temperature and concentration dependences of electrical conductivity and power factor revealed a promising use of InN for intermediate and high temperature thermoelectric applications. The rigid band approach and constant scattering time approximation were utilized in the calculations.

  16. Individual electron and hole localization in submonolayer InN quantum sheets embedded in GaN

    NASA Astrophysics Data System (ADS)

    Feix, F.; Flissikowski, T.; Chèze, C.; Calarco, R.; Grahn, H. T.; Brandt, O.

    2016-07-01

    We investigate sub-monolayer InN quantum sheets embedded in GaN(0001) by temperature-dependent photoluminescence spectroscopy under both continuous-wave and pulsed excitation. Both the peak energy and the linewidth of the emission band associated with the quantum sheets exhibit an anomalous dependence on temperature indicative of carrier localization. Photoluminescence transients reveal a power law decay at low temperatures reflecting that the recombining electrons and holes occupy spatially separate, individual potential minima reminiscent of conventional (In,Ga)N(0001) quantum wells exhibiting the characteristic disorder of a random alloy. At elevated temperatures, carrier delocalization sets in and is accompanied by a thermally activated quenching of the emission. We ascribe the strong nonradiative recombination to extended states in the GaN barriers and confirm our assumption by a simple rate-equation model.

  17. Structural and electronic properties of InN nanowire network grown by vapor-liquid-solid method

    SciTech Connect

    Barick, B. K. E-mail: subho-dh@yahoo.co.in; Dhar, S. E-mail: subho-dh@yahoo.co.in; Rodríguez-Fernández, Carlos; Cantarero, Andres

    2015-05-15

    Growth of InN nanowires have been carried out on quartz substrates at different temperatures by vapor-liquid-solid (VLS) technique using different thicknesses of Au catalyst layer. It has been found that a narrow window of Au layer thickness and growth temperature leads to multi-nucleation, in which each site acts as the origin of several nanowires. In this multi-nucleation regime, several tens of micrometer long wires with diameter as small as 20 nm are found to grow along [112{sup -}0] direction (a-plane) to form a dense network. Structural and electronic properties of these wires are studied. As grown nanowires show degenerate n-type behavior. Furthermore, x-ray photoemission study reveals an accumulation of electrons on the surface of these nanowires. Interestingly, the wire network shows persistence of photoconductivity for several hours after switching off the photoexcitation.

  18. Pressure based first-principles study of the electronic, elastic, optic and phonon properties of zincblende InN

    NASA Astrophysics Data System (ADS)

    Usman, Zahid; Cao, Chuanbao; Mahmood, Tariq

    2013-12-01

    Generalized gradient approximation proposed by Perdew-Burke-Ernzerhof (GGA-PBE) is used to determine the effect of pressure on electronic, elastic, acoustic, optical and vibrational properties of zincblende InN along with the Ultra soft pseudopotential method. The structural properties show good consistency and stability at elevated pressures. The zincblende InN displays zero band gap and its metallicity maintains even at high pressures. The density of states appear in a quarterly divided region, where the contribution of different states have been discussed, and it is found that the peak positions are consistent with experimental L1, L3, K absorption and emission edges. The effect of pressure appears in strong hybridization due to which DOS above and below the Fermi level are shifting to the corresponding higher and lower energies due to p-d hybridization. The calculated elastic constants agree well with the literature. Except C44 and Cs, all others show an increasing trend with the pressure. Acoustic wave speeds have been calculated in [100], [110] and [111] directions with the help of elastic constants for the first time. For the optical properties, the main peaks of the imaginary part of dielectric function lie in close vicinity of experiment and shift to higher energies with a reduction in peak intensities when the pressure effects come into play. Similarly the absorption peaks are red shifted with respect to hydro-static pressure. The refractive index is maximum at lower energies and its magnitude reduces with pressure and the maximum value of energy loss function is obtained corresponding to minimum dielectric function. Phonon frequencies in high symmetry directions agree well with the only available first principle study. Except XTA, WTA, and LTA, all the other modes show an increase in phonon frequencies when pressure is exerted, this is further confirmed by Gruneisen parameters calculated for the first time.

  19. Characterization of high quality InN grown on production-style plasma assisted molecular beam epitaxy system

    SciTech Connect

    Gherasoiu, I.; O'Steen, M.; Bird, T.; Gotthold, D.; Chandolu, A.; Song, D. Y.; Xu, S. X.; Holtz, M.; Nikishin, S. A.; Schaff, W. J.

    2008-05-15

    In this work, the authors report step-flow growth mode of InN on [0001] oriented GaN templates, using a production-style molecular beam epitaxy system, Veeco GEN200 registered , equipped with a plasma source. Using adaptive growth conditions, they have obtained a surface morphology that exhibits the step-flow features. The root mean squared roughness over an area of 5x5 {mu}m{sup 2} is 1.4 nm with monolayer height terrace steps (0.281 nm), based on atomic force microscopy. It has been found that the presence of In droplets leads to defective surface morphology. From x-ray diffraction, they estimate edge and screw dislocation densities. The former is dominant over the latter. Micro-Raman spectra reveal narrow E{sub 2}{sup 2} phonon lines consistent with excellent crystalline quality of the epitaxial layers. The Hall mobility of 1 {mu}m thick InN layers, grown in step-flow mode, is slightly higher than 1400 cm{sup 2}/V s, while for other growth conditions yielding a smooth surface with no well-defined steps, mobility as high as 1904 cm{sup 2}/V s at room temperature has been measured. The samples exhibit high intensity photoluminescence (PL) with a corresponding band edge that shifts with free carrier concentration. For the lowest carrier concentration of 5.6x10{sup 17} cm{sup -3}, they observe PL emission at {approx}0.64 eV.

  20. Growth kinetics and structural perfection of (InN)1/(GaN)1-20 short-period superlattices on +c-GaN template in dynamic atomic layer epitaxy

    NASA Astrophysics Data System (ADS)

    Kusakabe, Kazuhide; Hashimoto, Naoki; Itoi, Takaomi; Wang, Ke; Imai, Daichi; Yoshikawa, Akihiko

    2016-04-01

    The growth kinetics and structural perfection of (InN)1/(GaN)1-20 short-period superlattices (SPSs) were investigated with their application to ordered alloys in mind. The SPSs were grown on +c-GaN template at 650 °C by dynamic atomic layer epitaxy in conventional plasma-assisted molecular beam epitaxy. It was found that coherent structured InN/GaN SPSs could be fabricated when the thickness of the GaN barrier was 4 ML or above. Below 3 ML, the formation of SPSs was quite difficult owing to the increased strain in the SPS structure caused by the use of GaN as a template. The effective or average In composition of the (InN)1/(GaN)4 SPSs was around 10%, and the corresponding InN coverage in the ˜1 ML-thick InN wells was 50%. It was found that the effective InN coverage in ˜1 ML-thick InN wells could be varied with the growth conditions. In fact, the effective In composition could be increased up to 13.5%, i.e., the corresponding effective InN coverage was about 68%, by improving the capping/freezing speed by increasing the growth rate of the GaN barrier layer.

  1. Extraordinary N atom tunneling in formation of InN shell layer on GaN nanorod m-plane sidewall.

    PubMed

    Cai, Duanjun; Lin, Na; Xu, Hongmei; Liao, Che-Hao; Yang, C C

    2014-12-12

    We report the extraordinary tunneling process that finds the lower cohesive energy route for stablizing InN shell layer on m-plane sidewall of GaN nanorod. The [0001] orientated GaN nanorod array is grown on sapphire substrate patterned with Ga nanoparticle by metal-organic vapor deposition method, based on which the simulation structures of c-plane top surface and m-plane sidewall surface is constructed for the first-principles calculations. The results show that the introduction of In wetting monolayer could effectively lower the cohesive energy of adalayers on non-polar GaN surfaces. Most importantly, it is revealed that there exists an extraordinary tunneling process in which the N atoms will drag out the In wetting atoms and tunnel through to form stable InN shell layer on the nanorod sidewall. PMID:25412649

  2. Effects of Ga on the growth of InN on O-face ZnO(0001) by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Cho, Yong Jin; Riechert, Henning; Brandt, Oliver; Korytov, Maxim; Albrecht, Martin

    2012-07-30

    We compare the structural properties of InN and In{sub 0.95}Ga{sub 0.05}N films grown on O-face ZnO(0001) substrates at different temperatures. The small amount of Ga results in dramatic changes in the morphology and structural properties of InN. In particular, inversion domains start to appear at higher temperatures in the In{sub 0.95}Ga{sub 0.05}N film. This process is a consequence of the chemical reaction of ZnO with Ga which can be prevented by choosing the substrate temperature to be 450{sup Degree-Sign }C or below.

  3. Real-Time Optical Monitoring and Simulations of Gas Phase Kinetics in InN Vapor Phase Epitaxy at High Pressure

    NASA Technical Reports Server (NTRS)

    Dietz, Nikolaus; Woods, Vincent; McCall, Sonya D.; Bachmann, Klaus J.

    2003-01-01

    Understanding the kinetics of nucleation and coalescence of heteroepitaxial thin films is a crucial step in controlling a chemical vapor deposition process, since it defines the perfection of the heteroepitaxial film both in terms of extended defect formation and chemical integrity of the interface. The initial nucleation process also defines the film quality during the later stages of film growth. The growth of emerging new materials heterostructures such as InN or In-rich Ga(x)In(1-x)N require deposition methods operating at higher vapor densities due to the high thermal decomposition pressure in these materials. High nitrogen pressure has been demonstrated to suppress thermal decomposition of InN, but has not been applied yet in chemical vapor deposition or etching experiments. Because of the difficulty with maintaining stochiometry at elevated temperature, current knowledge regarding thermodynamic data for InN, e.g., its melting point, temperature-dependent heat capacity, heat and entropy of formation are known with far less accuracy than for InP, InAs and InSb. Also, no information exists regarding the partial pressures of nitrogen and phosphorus along the liquidus surfaces of mixed-anion alloys of InN, of which the InN(x)P(1-x) system is the most interesting option. A miscibility gap is expected for InN(x)P(1-x) pseudobinary solidus compositions, but its extent is not established at this point by experimental studies under near equilibrium conditions. The extension of chemical vapor deposition to elevated pressure is also necessary for retaining stoichiometric single phase surface composition for materials that are characterized by large thermal decomposition pressures at optimum processing temperatures.

  4. High-quality InN films on MgO (100) substrates: The key role of 30° in-plane rotation

    SciTech Connect

    Compeán García, V. D.; López Luna, E.; Rodríguez, A. G.; Vidal, M. A.; Orozco Hinostroza, I. E.; Escobosa Echavarría, A.

    2014-05-12

    High crystalline layers of InN were grown on MgO(100) substrates by gas source molecular beam epitaxy. Good quality films were obtained by means of an in-plane rotation process induced by the annealing of an InN buffer layer to minimize the misfit between InN and MgO. In situ reflection high-energy electron diffraction showed linear streaky patterns along the [011{sup ¯}0] azimuth and a superimposed diffraction along the [112{sup ¯}0] azimuth, which correspond to a 30° α-InN film rotation. This rotation reduces the mismatch at the MgO/InN interface from 19.5% to less than 3.5%, increasing the structural quality, which was analyzed by high-resolution X-ray diffraction and Raman spectroscopy. Only the (0002) c plane diffraction of α-InN was observed and was centered at 2θ = 31.4°. Raman spectroscopy showed two modes corresponding to the hexagonal phase: E1(LO) at 591 cm{sup −1} and E2(high) at 488 cm{sup −1}. Hall effect measurements showed a carrier density of 9 × 10{sup 18} cm{sup −3} and an electron Hall mobility of 340 cm{sup 2}/(V s) for a film thickness of 140 nm.

  5. Reduced threading dislocation densities in high-T/N-rich grown InN films by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Loitsch, Bernhard; Schuster, Fabian; Stutzmann, Martin; Koblmueller, Gregor

    2013-02-04

    We explore the effect of growth kinetics on the structural properties of In-polar InN films on GaN templates grown near the thermal dissociation limit by plasma-assisted molecular beam epitaxy. Unlike the common growth temperature limit (T Almost-Equal-To 500 Degree-Sign C) for In-polar InN grown under In-rich conditions, slightly N-rich conditions are demonstrated to shift the available growth temperature window to much higher temperatures (by >50 Degree-Sign C). InN films grown in this high-T/N-rich regime show significantly reduced off-axis X-ray diffraction rocking curve peak widths and record low threading dislocation densities (TDD {approx} 4 Multiplication-Sign 10{sup 9} cm{sup -2}) even for film thicknesses <1 {mu}m, as compared to state of the art In-rich growth. The reduction of TDD is attributed to more effective TD inclination and annihilation under N-rich growth, delineating prospective routes for improved InN-based materials.

  6. Electron mobility of self-assembled and dislocation free InN nanorods grown on GaN nano wall network template

    NASA Astrophysics Data System (ADS)

    Tangi, Malleswararao; De, Arpan; Ghatak, Jay; Shivaprasad, S. M.

    2016-05-01

    A kinetically controlled two-step growth process for the formation of an array of dislocation free high mobility InN nanorods (NRs) on GaN nanowall network (NWN) by Molecular Beam Epitaxy is demonstrated here. The epitaxial GaN NWN is formed on c-sapphire under nitrogen rich conditions, and then changing the source from Ga to In at appropriate substrate temperature yields the nucleation of a self assembled spontaneous m-plane side faceted-InN NR. By HRTEM, the NRs are shown to be dislocation-free and have a low band gap value of 0.65 eV. Hall measurements are carried out on a single InN NR along with J-V measurements that yield mobility values as high as ≈4453 cm2/V s and the carrier concentration of ≈1.1 × 1017 cm-3, which are unprecedented in the literature for comparable InN NR diameters.

  7. Ultrahigh polarimetric image contrast enhancement for skin cancer diagnosis using InN plasmonic nanoparticles in the terahertz range

    NASA Astrophysics Data System (ADS)

    Ney, Michael; Abdulhalim, Ibrahim

    2015-12-01

    Mueller matrix imaging sensitivity, to delicate water content changes in tissue associated with early stages of skin cancer, is demonstrated by numerical modeling to be enhanced by localized surface plasmon resonance (LSPR) effects at the terahertz (THz) range when InN nanoparticles (NPs) coated with Parylene-C are introduced into the skin. A skin tissue model tailored for THz wavelengths is established for a Monte Carlo simulation of polarized light propagation and scattering, and a comparative study based on simulated Mueller matrices is presented considering different NPs' parameters and insertion into the skin methods. The insertion of NPs presenting LSPR in the THz is demonstrated to enable the application of polarization-based sample characterization techniques adopted from the scattering dominated visible wavelengths domain for the, otherwise, relatively low scattering THz domain, where such approach is irrelevant without the NPs. Through these Mueller polarimetry techniques, the detection of water content variations in the tissue is made possible and with high sensitivity. This study yields a limit of detection down to 0.0018% for relative changes in the water content based on linear degree of polarization-an improvement of an order of magnitude relative to the limit of detection without NPs calculated in a previous ellipsometric study.

  8. Ultrahigh polarimetric image contrast enhancement for skin cancer diagnosis using InN plasmonic nanoparticles in the terahertz range.

    PubMed

    Ney, Michael; Abdulhalim, Ibrahim

    2015-01-01

    Mueller matrix imaging sensitivity, to delicate water content changes in tissue associated with early stages of skin cancer, is demonstrated by numerical modeling to be enhanced by localized surface plasmon resonance (LSPR) effects at the terahertz (THz) range when InN nanoparticles (NPs) coated with Parylene-C are introduced into the skin. A skin tissue model tailored for THz wavelengths is established for a Monte Carlo simulation of polarized light propagation and scattering, and a comparative study based on simulated Mueller matrices is presented considering different NPs’ parameters and insertion into the skin methods. The insertion of NPs presenting LSPR in the THz is demonstrated to enable the application of polarization-based sample characterization techniques adopted from the scattering dominated visible wavelengths domain for the, otherwise, relatively low scattering THz domain, where such approach is irrelevant without the NPs. Through these Mueller polarimetry techniques, the detection of water content variations in the tissue is made possible and with high sensitivity. This study yields a limit of detection down to 0.0018% for relative changes in the water content based on linear degree of polarization--an improvement of an order of magnitude relative to the limit of detection without NPs calculated in a previous ellipsometric study.

  9. Validation of a simple distributed sediment delivery approach in selected sub-basins of the River Inn catchment area

    NASA Astrophysics Data System (ADS)

    Reid, Lucas; Kittlaus, Steffen; Scherer, Ulrike

    2015-04-01

    For large areas without highly detailed data the empirical Universal Soil Loss Equation (USLE) is widely used to quantify soil loss. The problem though is usually the quantification of actual sediment influx into the rivers. As the USLE provides long-term mean soil loss rates, it is often combined with spatially lumped models to estimate the sediment delivery ratio (SDR). But it gets difficult with spatially lumped approaches in large catchment areas where the geographical properties have a wide variance. In this study we developed a simple but spatially distributed approach to quantify the sediment delivery ratio by considering the characteristics of the flow paths in the catchments. The sediment delivery ratio was determined using an empirical approach considering the slope, morphology and land use properties along the flow path as an estimation of travel time of the eroded particles. The model was tested against suspended solids measurements in selected sub-basins of the River Inn catchment area in Germany and Austria, ranging from the high alpine south to the Molasse basin in the northern part.

  10. A new perspective on soil erosion: exploring a thermodynamic approach in a small area of the River Inn catchment

    NASA Astrophysics Data System (ADS)

    Reid, Lucas; Scherer, Ulrike; Zehe, Erwin

    2016-04-01

    Soil erosion modeling has always struggled with compensating for the difference in time and spatial scale between model, data and the actual processes involved. This is especially the case with non-event based long-term models based on the Universal Soil Loss Equation (USLE), yet USLE based soil erosion models are among the most common and widely used for they have rather low data requirements and can be applied to large areas. But the majority of mass from soil erosion is eroded within short periods of times during heavy rain events, often within minutes or hours. Advancements of the USLE (eg. the Modified Universal Soil Loss Equation, MUSLE) allow for a daily time step, but still apply the same empirical methods derived from the USLE. And to improve the actual quantification of sediment input into rivers soil erosion models are often combined with a Sediment Delivery Ratio (SDR) to get results within the range of measurements. This is still a viable approach for many applications, yet it leaves much to be desired in terms of understanding and reproducing the processes behind soil erosion and sediment input into rivers. That's why, instead of refining and retuning the existing methods, we explore a more comprehensive, physically consistent description on soil erosion. The idea is to describe soil erosion as a dissipative process (Kleidon et al., 2013) and test it in a small sub-basin of the River Inn catchment area in the pre-Alpine foothills. We then compare the results to sediment load measurements from the sub-basin and discuss the advantages and issues with the application of such an approach.

  11. Effects of the group V/III ratio and a gan inter-layer on the crystal quality of InN grown by using the hydride vapor-phase epitaxy method

    NASA Astrophysics Data System (ADS)

    Ha, Ju-Hyung; Wang, Juan; Lee, Won-Jae; Choi, Young-Jun; Lee, Hae-Yong; Kim, Jung-Gon; Harima, Hiroshi

    2015-03-01

    The hydride vapor-phase epitaxy (HVPE) method was used to deposit high-quality InN layers on GaN inter-layer/sapphire (0001) structures that had been fabricated by using either the HVPE method or the metal-organic chemical-phase deposition (MOCVD) method. The effects of the group V/III ratio and different GaN inter-layers on the crystal quality of the InN layers were systemically investigated. The InN layer grown at a low Group V/III ratio revealed a high crystal quality with a two-dimensional (2D) growth mode. Also, the 110.7-nm-thick InN layer grown by using HVPE on a GaN inter-layer/sapphire (0001) substrate structure that had been fabricated by using MOCVD had a high crystal quality, with the full width at half maximum (FWHM) of the InN X-ray diffraction (XRD) peak being about 844 arcsec, and a smooth surface with an atomic force microscopy (AFM) roughness of about 0.07 nm. On the other hand, the 145.7-nm-thick InN layer grown by using HVPE on a GaN inter-layer/sapphire (0001) substrate structure that had been fabricated by using the HVPE method had a lower crystal quality, a FWHM value for the InN (0002) peak of about 2772 arcsec, and a surface roughness of about 3.73 nm. In addition, the peak of the E2 (high) phonon mode for the 110.7-nm-thick InN layer grown by using HVPE on a GaN inter-layer/sapphire (0001) structure that had been fabricated by using MOCVD was detected at 491 cm -1 and had a FWHM of 9.9 cm-1. As a result, InN layers grown by using HVPE on GaN inter-layer/sapphire (0001) substrate structures fabricated by using MOCVD have a high crystal quality and a reduced Raman value, which agrees well with the results of the XRD analysis.

  12. Structural and electrical properties of reactively sputtered InN thin films on AlN-buffered (00.1) sapphire substrates: Dependence on buffer and film growth temperatures and thicknesses

    NASA Astrophysics Data System (ADS)

    Kistenmacher, T. J.; Ecelberger, S. A.; Bryden, W. A.

    1993-08-01

    An extensive investigation of InN overlayers on AlN-buffered (00.1) sapphire by reactive magnetron sputtering has been undertaken and the dependencies of several basic materials properties (film thickness, development and quality of heteroepitaxy, film morphology, and electrical transport) on such key deposition parameters such as the growth temperatures of the insulating AlN buffer layer and the InN overlayer and their thicknesses have been determined. Three prominent effects of the AlN buffer layer are (1) the stabilization of heteroepitaxial growth over a broad range of film and buffer layer growth temperatures; (2) the attainment of a higher Hall mobility (up to 60 cm2/V s) over much of the same range; and, (3) the retention of heteroepitaxial growth, higher Hall mobility, and pseudo-two-dimensional growth even in the limit of an InN layer of ˜40 Å. In the context of a structure-zone model, the AlN buffer layer is projected to effectively raise the growth temperature of the InN thin film. The increase in effective growth temperature is, however, insufficient to overcome low atomic and cluster mobility and to achieve single-crystal InN thin film growth.

  13. The effect of McInnes solution on enamel and the effect of Tooth mousse on bleached enamel: An in vitro study

    PubMed Central

    Darshan, H E; Shashikiran, N D

    2008-01-01

    Aims: To evaluate the effect of McInnes bleaching agent on the micro hardness of enamel before and after bleaching and to evaluate the effect of G C Tooth Mousse on the bleached enamel surface for its microhardness. Materials and Methods: McInnes bleaching solution, Casein phosphopeptide-amorphous calcium phosphate CCP-ACP (G C Tooth mousse) artificial saliva (Dept of Oral Pathology, College of Dental Sciences, Davengere), deionized water, Vickers Micro Hardness tester (Zwick/ZHV, Germany), freshly extracted teeth, cold cure acrylic, Diamond disc (Horico - PFINGST New jersey USA, KAVO- Germany), straight handpiece (kavo peca reta) and plastic moulds (6.5 × 2 mm). The purpose of this study was to evaluate and compare microhardness of the sound enamel surface by Vickers Hardness Number before and after bleaching with McInnes solution, and to evaluate the effect of casein phosphopeptide amorphous calcium phosphate (G C Tooth Mousse) on the bleached enamel surface for its microhardness. Statistical analysis: The data obtained from the test were subjected for statistical analysis and are presented as range, mean and standard deviation. P value of 0.05 or less was considered for statistical significance. The changes in microhardness at different times of assessment were analyzed using the paired ‘t’ test Results: All the samples showed decrease in the microhardness after two cycles of bleaching, though immediately after bleaching the decrease in the microhardness was not significant (P = 0.34). However, after the second cycles, it showed a significant decrease (P<0.01) in the microhardness. After application of remineralization solution (GC Tooth mousse), the samples showed a marginal increase in the microhardness (P<0.05) after seven days and a marked increase after fourteen days (P<0.001). Conclusion: McInnes bleaching agent does decrease the microhardness of enamel by causing enamel demineralization and GC Tooth mousse used in the study causes an increase in the

  14. Growth of high-quality InN thin films on InGaN buffer layer by plasma-assisted molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Yang, Chen-Chi; Lo, Ikai; Shih, Cheng-Hung; Hu, Chia-Hsuan; Wang, Ying-Chieh; Lin, Yu-Chiao; Tasi, Cheng-Da; You, Shuo-Ting

    2015-03-01

    Four samples were grown on 2 inch c-plane (0001) sapphire substrates with 4 μm-thick GaN template. The InN thin films were grown on InGaN buffer layer by low-temperature plasma-assisted molecular beam epitaxy (PAMBE) system. These samples were grown under a varied temperature of InGaN buffer layers: 500°C, 540°C, 570°C, and 600°C. The structure properties of these samples were analyzed by X-ray diffraction (XRD). The interference fringes of InN grown on the sample 1 (the growth temperature of InGaN buffer layer at 500°C) exhibit prominent oscillations, which indicates that the sample has a high quality and layer by layer epitaxial structure. The surface morphology and microstructure of samples were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). We confirmed the smooth surface and high quality crystalline for the sample.

  15. SpaceInn hare-and-hounds exercise: Estimation of stellar properties using space-based asteroseismic data

    NASA Astrophysics Data System (ADS)

    Reese, D. R.; Chaplin, W. J.; Davies, G. R.; Miglio, A.; Antia, H. M.; Ball, W. H.; Basu, S.; Buldgen, G.; Christensen-Dalsgaard, J.; Coelho, H. R.; Hekker, S.; Houdek, G.; Lebreton, Y.; Mazumdar, A.; Metcalfe, T. S.; Silva Aguirre, V.; Stello, D.; Verma, K.

    2016-07-01

    Context. Detailed oscillation spectra comprising individual frequencies for numerous solar-type stars and red giants are either currently available, e.g. courtesy of the CoRoT, Kepler, and K2 missions, or will become available with the upcoming NASA TESS and ESA PLATO 2.0 missions. The data can lead to a precise characterisation of these stars thereby improving our understanding of stellar evolution, exoplanetary systems, and the history of our galaxy. Aims: Our goal is to test and compare different methods for obtaining stellar properties from oscillation frequencies and spectroscopic constraints. Specifically, we would like to evaluate the accuracy of the results and reliability of the associated error bars, and to see where there is room for improvement. Methods: In the context of the SpaceInn network, we carried out a hare-and-hounds exercise in which one group, the hares, simulated observations of oscillation spectra for a set of ten artificial solar-type stars, and a number of hounds applied various methods for characterising these stars based on the data produced by the hares. Most of the hounds fell into two main groups. The first group used forward modelling (i.e. applied various search/optimisation algorithms in a stellar parameter space) whereas the second group relied on acoustic glitch signatures. Results: Results based on the forward modelling approach were accurate to 1.5% (radius), 3.9% (mass), 23% (age), 1.5% (surface gravity), and 1.8% (mean density), as based on the root mean square difference. Individual hounds reached different degrees of accuracy, some of which were substantially better than the above average values. For the two 1M⊙ stellar targets, the accuracy on the age is better than 10% thereby satisfying the requirements for the PLATO 2.0 mission. High stellar masses and atomic diffusion (which in our models does not include the effects of radiative accelerations) proved to be sources of difficulty. The average accuracies for the

  16. Annual Review of BPA-Funded Projects in Natural and Artificial Propagation of Salmonids, March 27-29, 1985, Holiday Inn Airport, Portland, Oregon.

    SciTech Connect

    United States. Bonneville Power Administration.

    1985-04-01

    The Fish and Wildlife Division of Bonneville Power Administration (BPA) hosted a meeting for contractors to present the results of fiscal year 1984 research conducted to implement the Northwest Power Planning Council's Fish and Wildlife Program. The meeting focused on those projects specifically related to natural and artificial propagation of salmonids. The presentations were held at the Holiday Inn Airport in Portland, Oregon, on March 27-29, 1985. This document contains abstracts of the presentations from that meeting. Section 1 contains abstracts on artificial propagation, fish health, and downstream migration, and Section 2 contains abstracts on natural propagation and habitat improvement. The abstracts are indexed by BPA Project Number and by Fish and Wildlife Program Measure. The registered attendees at the meeting are listed alphabetically in Appendix A and by affiliation in Appendix B.

  17. Impact of Mg concentration on energy-band-depth profile of Mg-doped InN epilayers analyzed by hard X-ray photoelectron spectroscopy

    SciTech Connect

    Imura, M.; Tsuda, S.; Nagata, T.; Takeda, H.; Liao, M. Y.; Koide, Y.; Yang, A. L.; Yamashita, Y.; Yoshikawa, H.; Kobayashi, K.; Kaneko, M.; Uematsu, N.; Wang, K.; Araki, T.; Nanishi, Y.

    2013-10-14

    The electronic structures of Mg-doped InN (Mg-InN) epilayers with the Mg concentration, [Mg], ranging from 1 × 10{sup 19} to 5 × 10{sup 19} cm{sup −3} were systematically investigated by soft and hard X-ray photoelectron spectroscopies. The angle-resolved results on the core-level and valence band photoelectron spectra as a function of [Mg] revealed that the energy band of Mg-InN showed downward bending due to the n{sup +} surface electron accumulation and p type layers formed in the bulk. With an increase in [Mg], the energy-band changed from monotonic to two-step n{sup +}p homojunction structures. The oxygen concentration rapidly increased at the middle-bulk region (∼4.5 to ∼7.5 nm) from the surface, which was one of the reasons of the transformation of two-step energy band.

  18. High rate dry etching of GaN, AlN and InN in ECR Cl{sub 2}/CH{sub 4}/H{sub 2}/Ar plasmas

    SciTech Connect

    Vartuli, C.B.; Pearton, S.J.; Abernathy, C.R.; Shul, R.J.; Kilcoyne, S.P.; Crawford, M.H.; Howard, A.J.; Parmeter, J.E.

    1995-05-01

    Etch rates for binary nitrides in ECR Cl{sub 2}/CH{sub 4}/H{sub 2}/Ar are reported as a function of temperature, rf-bias, microwave power, pressure and relative gas proportions. GaN etch rates remain relatively constant from 30 to 125{degrees}C and then increase to a maximum of 2340 {angstrom}-min{sup {minus}1} at 170{degrees}C. The AlN etch rate decreases throughout the temperature range studied with a maximum of 960 {angstrom}-min{sup {minus}1} at 30{degrees}C. When CH{sub 4} is removed from the plasma chemistry, the GaN and InN etch rates are slightly lower, with less dramatic changes with temperature. The surface composition of the III-V nitrides remains unchanged over the temperatures studied. The GaN and InN rates increase significantly with rf power, and the fastest rates for all three binaries are obtained at 2 mTorr. Surface morphology is smooth for GaN over a wide range of conditions, whereas InN surfaces are more sensitive to plasma parameters.

  19. Point defects introduced by InN alloying into In{sub x}Ga{sub 1-x}N probed using a monoenergetic positron beam

    SciTech Connect

    Uedono, A.; Tsutsui, T.; Watanabe, T.; Kimura, S.; Zhang, Y.; Lozac'h, M.; Sang, L. W.; Sumiya, M.; Ishibashi, S.

    2013-03-28

    Native defects in In{sub x}Ga{sub 1-x}N (x = 0.06-0.14) grown by metal organic chemical vapor deposition were studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation as a function of incident positron energy for In{sub x}Ga{sub 1-x}N showed that vacancy-type defects were introduced with increasing InN composition, and the major defect species was identified as complexes between a cation vacancy and a nitrogen vacancy. The concentration of the divacancy, however, was found to be suppressed by Mg doping. The momentum distribution of electrons at the In{sub x}Ga{sub 1-x}N/GaN interface was close to that in defect-free GaN or In{sub x}Ga{sub 1-x}N, which was attributed to localization of positrons at the interface due to the built-in electric field, and to suppression of positron trapping by vacancy-type defects. We have also shown that the diffusion property of positrons is sensitive to an electric field near the In{sub x}Ga{sub 1-x}N/GaN interface.

  20. InGaN/GaN multiple-quantum-well light-emitting diodes with a grading InN composition suppressing the Auger recombination

    SciTech Connect

    Zhang, Zi-Hui; Liu, Wei; Ju, Zhengang; Tan, Swee Tiam; Ji, Yun; Kyaw, Zabu; Zhang, Xueliang; Wang, Liancheng; Sun, Xiao Wei E-mail: VOLKAN@stanfordalumni.org; Demir, Hilmi Volkan E-mail: VOLKAN@stanfordalumni.org

    2014-07-21

    In conventional InGaN/GaN light-emitting diodes (LEDs), thin InGaN quantum wells are usually adopted to mitigate the quantum confined Stark effect (QCSE), caused due to strong polarization induced electric field, through spatially confining electrons and holes in small recombination volumes. However, this inevitably increases the carrier density in quantum wells, which in turn aggravates the Auger recombination, since the Auger recombination scales with the third power of the carrier density. As a result, the efficiency droop of the Auger recombination severely limits the LED performance. Here, we proposed and showed wide InGaN quantum wells with the InN composition linearly grading along the growth orientation in LED structures suppressing the Auger recombination and the QCSE simultaneously. Theoretically, the physical mechanisms behind the Auger recombination suppression are also revealed. The proposed LED structure has experimentally demonstrated significant improvement in optical output power and efficiency droop, proving to be an effective solution to this important problem of Auger recombination.

  1. The effect of electrical properties for InGaN and InN by high-energy particle irradiation (notice of removal)

    NASA Astrophysics Data System (ADS)

    Dong, Shao-guang; Fan, Guang-han

    2008-03-01

    This paper (SPIE Paper 68411H) was removed from the SPIE Digital Library on 8 August 2008 upon discovery that the paper has substantially plagiarized the following two papers: R.E. Jones, S.X. Li, L. Hsu, K.M. Yu, W. Walukiewicz, Z. Liliental-Weber, J.W. Ager III, E.E. Haller, H. Lu, and W.J. Schaff, "Native-defect-controlled n-type conductivity in InN," Physica B 376-377 (2006) 436-439 and S.X. Li, K.M. Yu, J. Wu, R.E. Jones, W. Walukiewicz, J.W. Ager III, W. Shan, E.E. Haller, Hai Lu, and William J. Schaff, "Native defects in InxGa1-xN alloys," Physica B 376-377 (2006) 432-435. As stated in the SPIE Publication Ethics Guidelines, "SPIE defines plagiarism as the reuse of someone else's prior ideas, processes, results, or words without explicit attribution of the original author and source, or falsely representing someone else's work as one's own. Unauthorized use of another researcher's unpublished data or findings without permission is considered to be a form of plagiarism even if the source is attributed. SPIE considers plagiarism in any form, at any level, to be unacceptable and a serious breach of professional conduct." It is SPIE policy to remove such papers and to provide citations to original sources so that interested readers can obtain the information directly from those sources. One of the authors, Shao-guang Dong, accepts full responsibility and apologizes for this plagiarism and has absolved the second author, Guang-han Fan, of any prior knowledge of or professional misconduct in this matter. Guang-han Fan also states that he had not previously seen the paper or given permission to include his name as an author.

  2. Low Temperature Growth of In2O3and InN Nanocrystals on Si(111) via Chemical Vapour Deposition Based on the Sublimation of NH4Cl in In

    PubMed Central

    2009-01-01

    Indium oxide (In2O3) nanocrystals (NCs) have been obtained via atmospheric pressure, chemical vapour deposition (APCVD) on Si(111) via the direct oxidation of In with Ar:10% O2at 1000 °C but also at temperatures as low as 500 °C by the sublimation of ammonium chloride (NH4Cl) which is incorporated into the In under a gas flow of nitrogen (N2). Similarly InN NCs have also been obtained using sublimation of NH4Cl in a gas flow of NH3. During oxidation of In under a flow of O2the transfer of In into the gas stream is inhibited by the formation of In2O3around the In powder which breaks up only at high temperatures, i.e.T > 900 °C, thereby releasing In into the gas stream which can then react with O2leading to a high yield formation of isolated 500 nm In2O3octahedrons but also chains of these nanostructures. No such NCs were obtained by direct oxidation forTG < 900 °C. The incorporation of NH4Cl in the In leads to the sublimation of NH4Cl into NH3and HCl at around 338 °C which in turn produces an efficient dispersion and transfer of the whole In into the gas stream of N2where it reacts with HCl forming primarily InCl. The latter adsorbs onto the Si(111) where it reacts with H2O and O2leading to the formation of In2O3nanopyramids on Si(111). The rest of the InCl is carried downstream, where it solidifies at lower temperatures, and rapidly breaks down into metallic In upon exposure to H2O in the air. Upon carrying out the reaction of In with NH4Cl at 600 °C under NH3as opposed to N2, we obtain InN nanoparticles on Si(111) with an average diameter of 300 nm. PMID:20596336

  3. High resolution meteorological modellingof the Inn Valley atmosphere, Part I

    NASA Astrophysics Data System (ADS)

    Schicker, I.; Arnold, D.; Seibert, P.

    2009-09-01

    Orography and local meteorology play a major role in Alpine valleys, as they are linked with valley and slope wind systems, stagnation and recirculation, temperature inversions and turbulence. Thus, they have a strong influence of transport and dilution of pollutants in the valley, affecting human health, and sound propagation. Shallow stable layers at the valley floor and low wind speed conditions, especially in autumn and winter, trap pollutants and thus cause unfavourable dispersion conditions , possibly leading to exceedances of air pollution limits. Moreover, under certain synoptic conditions such as persistent high-pressure systems inversion conditions prevail for days. Emissions may accumulate in the valley from day to day and thus critical levels of pollutants may be reached. With the current computer capabilities, numerical meteorological models and particle dispersion models are powerful tools to investigate such situations and their impact on emission-side measures. However, alpine valleys and other complex topographical areas require very high resolutions to ensure accurate representation of the physical processes. Typically, the highest resolutions used nowadays in episodic simulations with models such as, e.g., RAMS, WRF, or MM5, are around 1 km. This still smooths the orography, cutting the peaks and raising the valley bottoms. In this work a comparison of the simulation of the valley atmosphere with two meteorological models, MM5 and WRF, with high horizontal (0.6 km to 0.2 km) and vertical resolutions (35 to 39 half-s levels) is carried out for selected scenarios in which levels of pollutants exceeded air pollution limits. For a better representation of the orography SRTM 3" topography data is used in MM5 for resolutions below 1 km (~ resolution of SRTM 30" data), WRF will be tested only with SRTM 30" due to computational time constraints. The evolution of the valley atmosphere is studied using different PBL schemes available in the models as well as land-use representations. Rawinsonde data of the Innsbruck airport station and observation data of Innsbruck University and Patscherkofel will be used for comparison. These high-resolution simulations are very demanding in computational terms. Therefore, an evaluation of the computer demands of each of the simulations is also carried out. In order to asses the influence of this high resolution meteorological modelling on air quality conditions, further work with a dispersion model/chemistry model will be carried out and compared to observations (see contribution by Arnold et al., this session).

  4. [SwapINN: analytic study about prescription swaps at pharmacies].

    PubMed

    Moutinho, Ana; Alexandra, Denise; Rodrigues, Renata

    2014-01-01

    Introdução: A prescrição obrigatória por DCI foi imposta em 2012, para redução de custos do SNS e motivou discussão entre as partes envolvidas. Estudámos, numa população real, a dinâmica prescrição-dispensa de medicamentos.Objetivos: Determinar a percentagem de prescrições substituídas; avaliar os fatores associados à substituição; identificar as respetivas justificações; quantificar os diferenciais dos custos para utente e Serviço Nacional de Saúde.Material e Métodos: Estudo analítico. Amostra de conveniência constituída pelos medicamentos prescritos de uma unidade de saúde, de 19 a 23 de Dezembro de 2011. Três dias depois, os utentes foram entrevistados telefonicamente. Software: Excel® e SPSS®. Testes: Qui-quadrado e Mann-Whitney; n.s. = 0,05.Resultados: Total de 255 prescrições. A maioria foi efetuada a mulheres (62%), idade média 52 anos, 4 anos de escolaridade (33%) e para situações agudas (53%). Foram substituídas 31% das prescrições, sem relação com idade, sexo ou escolaridade, nem com o médico prescritor ou farmácia. Os medicamentos prescritos para situações crónicas foram menos substituídos (p < 0,001), assim como as prescrições de marca (p < 0,001). Os anti-infeciosos e anti-alérgicos foram os grupos com mais substituições (p = 0,009). Os utentes não se aperceberam da substituição em 72% dos casos. Nos casos de substituição, o utente pagou, em média, mais 79% que o prescrito e o Serviço Nacional de Saúde 5%.Discussão/Conclusão: Verificou-se substituição de 31% das prescrições, com mais custos para utente e Serviço Nacional de Saúde. Consideramos possível viés de seleção, informação e registo. Sendo agora obrigatória a prescrição por DCI, sugerimos a análise regular, a nível nacional, com base nas aplicações informáticas em uso, da prescrição e respetiva dispensa.

  5. Places in Time: The Inns and Outhouses of Rhetoric

    ERIC Educational Resources Information Center

    Mailloux, Steven

    2006-01-01

    Rhetoric is often about "good guys" and "bad guys." Even more basically, it concerns who is in and who is out, what is included and what is excluded, who is placed inside and who outside a cultural community, a political movement, a professional organization. These ins and outs concern both the commonplaces of rhetoric and the rhetoric of …

  6. No room at the inn: pregnancy and overcrowding.

    PubMed

    Nelson, Julianne

    2010-01-01

    The effects of poor housing conditions such as overcrowding cause pregnant women stress and are associated with adverse outcomes for the mother and risks to the child which may be long term for the child. The legal definition of overcrowding in England is complex. It dates from 1934 and needs modernising to take account of current standards and expectations. Approximately 3% of the population live in overcrowded conditions, with higher rates in rented accommodation and in London. Midwives' public health remit means that they need to be aware of housing needs among their clients and to seek solutions. Specialist midwives focusing on public health may be one solution to a challenging problem. The Family Nurse Partnership scheme and innovative public health assessment tools may also have a part to play in improving outcomes. So too will awareness of the organisations throughout the U.K. that assist people in housing need and campaign for better housing. Overall, it is a Government responsibility to ensure that as far as possible the needs of vulnerable families are met in all areas of the U.K. PMID:21053657

  7. No room at the inn: a snapshot of an American emergency room.

    PubMed

    Olson, E J

    1994-01-01

    The emergency rooms of American hospitals have frequently become the principal suppliers of nonurgent primary care to the under- and uninsured. Canvassing published reports and using original data obtained from a representative urban hospital, Erik Olson examines the demographics of the American emergency room and analyzes its finances. The costs of providing primary care are shifted, to the extent possible, to those who can pay. The result is escalating health care costs and a deterioration of quality of care due to overcrowding, leading some hospitals to close their emergency rooms and others to turn away ambulances or "dump" patients who still require critical care. Mr. Olson explains that state antidumping laws and the federal COBRA statute have been ineffective at stemming these practices in the face of severe economic pressure to continue them. Pointing out that emergency rooms are an excessively expensive method of treating uninsured nonemergency patients, he proposes a system of primary care clinics created through a public/private partnership between municipalities and existing private health care providers. The partnership is designed to maintain a high standard of care at the clinics. As an incentive to stimulate the appearance of such clinics, a tax would be imposed on private health care providers; the tax on a given provider would be reduced to the extent that provider subsidizes a local primary care clinic that offers universal coverage, regardless of insurance status. Because the existence of such clinics would reduce inefficient use of hospital emergency rooms, in the long run hospitals should find it less expensive to finance local primary care clinics than to continue to sustain unreimbursed expenses due to improper use of their emergency departments.

  8. Antioxidant potential of commercially available cumin (Cuminum cyminuml inn) in Pakistan.

    PubMed

    Bukhari, S Birjees; Iqbal, Shahid; Bhanger, M I

    2009-05-01

    Owing to increased safety concerns about synthetic antioxidants, exploitation of safer antioxidants based on natural origin is the focus of research nowadays. Cumin is a common spice and is used as a routine supportive cooking agent. Extracts of cumin were prepared in methanol, ethanol, dichloromethane and hexane by employing Soxhlet extraction apparatus. Determination of the total phenolic content, chelating activity, reducing power and free radical scavenging activity were taken as parameters for the assessment of antioxidant properties. The findings of this study suggest cumin to be a potent source of antioxidants. Results from the different parameters were in agreement with one another.

  9. Project EXCEL: Holiday Inn at Fisherman's Wharf, Housekeeping Department: Improving Customer Service, Module 3.

    ERIC Educational Resources Information Center

    Career Resources Development Center, Inc., San Francisco, CA.

    Project EXCEL is a federally-funded workplace literacy program involving hotel enterprises in the San Francisco (California) Bay area. Its focus is on identification and instruction of literacy skills essential to job success for limited-English-proficient (LEP) workers. Training is intended to enable employees to understand written work orders,…

  10. Solar hot water system installed at Days Inn Motel, Dallas, Texas (Forrest Lane)

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar system was designed to provide 65 percent of the total Domestic Hot Water (DHW) demand. The liquid flat plate (water) collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank located in the mechanical room when the pump is not running. Heat is transferred from the storage tank to DHW tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and the heat exchanger enables solar heated water to help make DHW tank standby losses. All pumps are controlled by differential temperature.

  11. Solar hot water system installed at Days Inn Motel, Dallas, Texas (Forrest Lane)

    NASA Astrophysics Data System (ADS)

    1980-09-01

    The solar system was designed to provide 65 percent of the total Domestic Hot Water (DHW) demand. The liquid flat plate (water) collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank located in the mechanical room when the pump is not running. Heat is transferred from the storage tank to DHW tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and the heat exchanger enables solar heated water to help make DHW tank standby losses. All pumps are controlled by differential temperature.

  12. Solar hot water system installed at Day's Inn Motel, Dallas, Texas (Valley View)

    NASA Astrophysics Data System (ADS)

    1980-09-01

    The solar system was designed to provide 65 percent of the total domestic hot water (DHW) demand. A liquid (water) flat plate collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank when the solar pump is not running. Heat is transferred from the DHW tanks through a shell and tube heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up standby losses. All pumps are controlled by differential temperature controllers.

  13. Solar hot water system installed at Day's Inn Motel, Dallas, Texas (Valley View)

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar system was designed to provide 65 percent of the total domestic hot water (DHW) demand. A liquid (water) flat plate collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank when the solar pump is not running. Heat is transferred from the DHW tanks through a shell and tube heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up standby losses. All pumps are controlled by differential temperature controllers.

  14. Long-term oxidization and phase transition of InN nanotextures

    PubMed Central

    2011-01-01

    The long-term (6 months) oxidization of hcp-InN (wurtzite, InN-w) nanostructures (crystalline/amorphous) synthesized on Si [100] substrates is analyzed. The densely packed layers of InN-w nanostructures (5-40 nm) are shown to be oxidized by atmospheric oxygen via the formation of an intermediate amorphous In-Ox-Ny (indium oxynitride) phase to a final bi-phase hcp-InN/bcc-In2O3 nanotexture. High-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and selected area electron diffraction are used to identify amorphous In-Ox-Ny oxynitride phase. When the oxidized area exceeds the critical size of 5 nm, the amorphous In-Ox-Ny phase eventually undergoes phase transition via a slow chemical reaction of atomic oxygen with the indium atoms, forming a single bcc In2O3 phase. PMID:21711908

  15. The Place Where Hope Lives: The Children's Inn Comforts Kids and Their Families

    MedlinePlus

    ... pointing to the name of NIH researcher Dr. William Gahl, a leader in the treatment of cystinosis. ... ll have her checkup. With Dr.Gahl: Dr. William Gahl (right) of the National Human Genome Research ...

  16. Conference on New Processes for Braille Manufacture (Ramada Inn, Boston, Massachusetts, May 18-19, 1967).

    ERIC Educational Resources Information Center

    Massachusetts Inst. of Tech., Cambridge. Sensory Aids Evaluation and Development Center.

    Proceedings from a conference on braille production and services are summarized. Only equipment which is ready for use is considered. Specific methods of producing braille discussed include the following: use of plates from a stereograph, computer line printer, braille embossers or braille writers, continuous strip embossed tape from a teletype…

  17. Solar hot water system installed at Day's Inn Motel, Savannah, Georgia

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The Solar System was designed to provide 50 percent of the total Domestic Hot Water (DHW) demand. Liquid Flat Plate Collectors (900 square feet) are used for the collector subsystem. The collector subsystem is closed loop, using 50 percent Ethylene Glycol solution antifreeze for freeze protection. The 1,000 gallon fiber glass storage tank contains two heat exchangers. One of the heat exchangers heats the storage tank with the collector solar energy. The other heat exchanger preheats the cold supply water as it passes through on the way to the Domestic Hot Water (DHW) tank heaters. Electrical energy supplements the solar energy for the DHW. The Collector Mounting System utilizes guy wires to structurally tie the collector array to the building.

  18. Sport Psychology Training in Counseling Psychology Programs: Is There Room at the Inn?

    ERIC Educational Resources Information Center

    Petrie, Trent A.; Watkins, C. Edward, Jr.

    1994-01-01

    Surveyed 53 counseling psychology programs about sport psychology training. Found that most respondents had students who were interested in sport psychology; counseling faculty were perceived to be receptive to their colleagues and graduate students having interests and pursuing research in sport psychology; and most program directors thought best…

  19. Solar hot water system installed at Days Inn Motel, Jacksonville, Florida

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar system was designed to provide 65 percent of the hot water demand. Water in the liquid flat plate collector (900 square feet) system automatically drains into the 1000 gallon lined and vented steel storage tank when the pump is not running. Heat is transferred from storage to Domestic Hot Water (DHW) tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up DHW standby losses. All pumps are controlled by differential temperature.

  20. Annual Review of BPA-Funded Anadromous Fish Projects, March 18-20, 1986, Holiday Inn Airport, Portland, Oregon.

    SciTech Connect

    United States. Bonneville Power Administration.

    1986-02-01

    This report contains descriptions of projects specifically related to anadromous salmonids. They include projects in the following categories: (1) fish and wildlife projects in western Montana; (2) fish health and physiology; (3) habitat enhancement and passage improvement - Oregon I; (4) passage improvement and natural propagation - Washington; (5) habitat enhancement and passage improvements - Oregon II; (6) future hydroelectric assessments; (7) habitat enhancement and passage improvement - Idaho; (8) downstream migration: flows and monitoring; (9) downstream migration: reservoir impacts; and (10) habitat evaluation and monitoring. (ACR)

  1. "Jus Fasque Esse in Rempublicam Litterariam Foeminas Adscribi" Gelehrt(inn) en-Enzyuklopadien Des 17 und 18 Janrhunderts.

    ERIC Educational Resources Information Center

    Rang, Brita

    1992-01-01

    Discusses contributions to the sciences by women. Contends that, even though women were excluded from higher education in the nineteenth century, they participated in noninstitutional forms of higher learning. Describes encyclopedias developed by women during this period that indicate a high level of science understanding. (CFR)

  2. Making Room at the Inn: Implications of "Christian Legal Society v. Martinez" for Public College and University Housing Professionals

    ERIC Educational Resources Information Center

    Waggoner, Michael D.; Russo, Charles J.

    2014-01-01

    The supreme court's ruling in "Christian Legal Society v. Martinez", its most important case to date on student associational activities, upheld a policy at a public law school in California that required recognized student organizations (or clubs) to admit "all-comers" even if they disagreed with organizational goals and…

  3. Enhanced memory effect via quantum confinement in 16 nm InN nanoparticles embedded in ZnO charge trapping layer

    SciTech Connect

    El-Atab, Nazek; Nayfeh, Ammar; Cimen, Furkan; Alkis, Sabri; Ortaç, Bülend; Alevli, Mustafa; Dietz, Nikolaus; Okyay, Ali K.

    2014-06-23

    In this work, the fabrication of charge trapping memory cells with laser-synthesized indium-nitride nanoparticles (InN-NPs) embedded in ZnO charge trapping layer is demonstrated. Atomic layer deposited Al{sub 2}O{sub 3} layers are used as tunnel and blocking oxides. The gate contacts are sputtered using a shadow mask which eliminates the need for any lithography steps. High frequency C-V{sub gate} measurements show that a memory effect is observed, due to the charging of the InN-NPs. With a low operating voltage of 4 V, the memory shows a noticeable threshold voltage (V{sub t}) shift of 2 V, which indicates that InN-NPs act as charge trapping centers. Without InN-NPs, the observed memory hysteresis is negligible. At higher programming voltages of 10 V, a memory window of 5 V is achieved and the V{sub t} shift direction indicates that electrons tunnel from channel to charge storage layer.

  4. Evaluation of interpolations of InN, AlN and GaN lattice and elastic constants for their ternary and quaternary alloys

    NASA Astrophysics Data System (ADS)

    Morales, F. M.; Mánuel, J. M.; García, R.; Reuters, B.; Kalisch, H.; Vescan, A.

    2013-06-01

    Structural and compositional data were collected for several high-quality strained InGaN, InAlN, AlGaN and InAlGaN layers with various compositions. Based on these results, the InN/AlN/GaN molar fractions of every film were indirectly estimated by the application of Vegard's law (Vegard 1921 Z. Phys. 5 17) to lattice and elastic constants of the binaries and by an alternative approach proposed by (Williams et al 1978 J. Electron. Mater. 7 639) (even considering possible mistakes in its application). True compositions were independently assessed by x-ray spectroscopy or Rutherford backscattering spectrometry. The results of both interpolation models are highlighted in utilizable contour and surface ternary plots of lattice constants and biaxial strain relaxation coefficients calculated for the whole compositional range. Calculated compositions from Vegard's law best fit the measured values. Finally, it is geometrically demonstrated that there are wrong assumptions in the Williams et al model, so that Vegard's law should only be used to successfully determine the compositions of ternary and quaternary III-N nitrides.

  5. No Room for the Inn. A Report on Local Opposition to Housing and Social Services Facilities for Homeless People in 36 United States Cities.

    ERIC Educational Resources Information Center

    National Law Center on Homelessness and Poverty, Washington, DC.

    In December 1994 the National Law Center on Homelessness and Poverty published an analysis of antihomeless laws and policies in 42 American cities. This report draws on those findings to focus on attempts to shut down or exclude service providers. Searches of the media, telephone interviews with service providers and public interest groups and…

  6. 39. DINING ROOM, LOOKING (NORTH) BACK TOWARD ENTRANCE. BEFORE 1907, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. DINING ROOM, LOOKING (NORTH) BACK TOWARD ENTRANCE. BEFORE 1907, GUESTS AT THE INN ATE FAMILY-STYLE AT LONG RECTANGULAR TABLES. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  7. 1. GENERAL VIEW OF ROUTE 209 LOOKING NORTH SHOWING SLEEPING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. GENERAL VIEW OF ROUTE 209 LOOKING NORTH SHOWING SLEEPING BEAR INN, SLEEPING BEAR INN GARAGE AND DORMITORY, D.H. DAY STORE, RESTROOM, AND GARAGE - Glen Haven Historic District, Route 209, Glen Arbor, Leelanau County, MI

  8. 77 FR 68764 - Parker Knoll Hydro, LLC; Notice of Intent To Prepare An Environmental Impact Statement and Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-16

    ...: Agency Scoping Meeting Date: December 11, 2012. Time: 10:00 a.m. (MST). Place: Holiday Inn Express....m. (MST). Place: Holiday Inn Express. Address: 20 West 1400 North, Richfield, Utah. Copies of...

  9. 18. Dining room at southwest corner of building, view to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Dining room at southwest corner of building, view to west. Scale stick visible against west wall, next to woman. - Deetjen's Big Sur Inn, Big Sur Inn Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  10. Multicenter Phase II Study Evaluating Two Cycles of Docetaxel, Cisplatin and Cetuximab as Induction Regimen Prior to Surgery in Chemotherapy-Naive Patients with NSCLC Stage IB-IIIA (INN06-Study)

    PubMed Central

    Hilbe, Wolfgang; Pall, Georg; Kocher, Florian; Pircher, Andreas; Zabernigg, August; Schmid, Thomas; Schumacher, Michael; Jamnig, Herbert; Fiegl, Michael; Gächter, Anne; Freund, Martin; Kendler, Dorota; Manzl, Claudia; Zelger, Bettina; Popper, Helmut; Wöll, Ewald

    2015-01-01

    Background Different strategies for neoadjuvant chemotherapy in patients with early stage NSCLC have already been evaluated. The aim of this study was to evaluate the tolerability and efficacy of a chemoimmunotherapy when limited to two cycles. Methods Between 01/2007 and 03/2010 41 patients with primarily resectable NSCLC stage IB to IIIA were included. Treatment consisted of two cycles cisplatin (40 mg/m2 d1+2) and docetaxel (75 mg/m2 d1) q3 weeks, accompanied by the administration of cetuximab (400 mg/m2 d1, then 250 mg weekly). The primary endpoint was radiological response according to RECIST. Results 40 patients were evaluable for toxicity, 39 for response. The main grade 3/4 toxicities were: neutropenia 25%, leucopenia 11%, febrile neutropenia 6%, nausea 8% and rash 8%. 20 patients achieved a partial response, 17 a stable disease, 2 were not evaluable. 37 patients (95%) underwent surgery and in three of them a complete pathological response was achieved. At a median follow-up of 44.2 months, 41% of the patients had died, median progression-free survival was 22.5 months. Conclusions Two cycles of cisplatin/ docetaxel/ cetuximab showed promising efficacy in the neoadjuvant treatment of early-stage NSCLC and rapid operation was possible in 95% of patients. Toxicities were manageable and as expected. Trial Registration EU Clinical Trials Register; Eudract-Nr: 2006-004639-31 PMID:26020783

  11. Satellite Instrument Calibration for Measuring Global Climate Change. Report of a Workshop at the University of Maryland Inn and Conference Center, College Park, MD. , November 12-14, 2002

    NASA Technical Reports Server (NTRS)

    Ohring, G.; Wielicki, B.; Spencer, R.; Emery, B.; Datla, R.

    2004-01-01

    Measuring the small changes associated with long-term global climate change from space is a daunting task. To address these problems and recommend directions for improvements in satellite instrument calibration some 75 scientists, including researchers who develop and analyze long-term data sets from satellites, experts in the field of satellite instrument calibration, and physicists working on state of the art calibration sources and standards met November 12 - 14, 2002 and discussed the issues. The workshop defined the absolute accuracies and long-term stabilities of global climate data sets that are needed to detect expected trends, translated these data set accuracies and stabilities to required satellite instrument accuracies and stabilities, and evaluated the ability of current observing systems to meet these requirements. The workshop's recommendations include a set of basic axioms or overarching principles that must guide high quality climate observations in general, and a roadmap for improving satellite instrument characterization, calibration, inter-calibration, and associated activities to meet the challenge of measuring global climate change. It is also recommended that a follow-up workshop be conducted to discuss implementation of the roadmap developed at this workshop.

  12. Growth, nitrogen vacancy reduction and solid solution formation in cubic GaN thin films and the subsequent fabrication of superlattice structures using AlN and inn. Final report, 1 June 1986-31 December 1992

    SciTech Connect

    Davis, R.F.

    1992-12-01

    An atomic layer epitaxy deposition system configured for the growth of thin films of the III-V nitrides of A1, Ga and In has been designed, constructed and commissioned. The system allows the introduction of up to 16 gases without mixing. Self-terminating growth of crystalline GaN films has been achieved on single crystal wafers of (0001) alpha(6H)-SiC. Results of analyses via Auger spectroscopy, electron microscopy and electron diffraction are described. Deposition of AIN and GaN via gas-source MBE was also continued during this period. The principal emphasis concerned the initial stages of growth of both compounds on the substrates of (00001) alpha(6H)-SiC and (0001) sapphire, as determined using X-ray photoelectron spectroscopy. An initial layer of silicon nitride formed on the surface of SiC prior to the deposition of either nitride. The deposition of GaN on sapphire followed the Stranski-Krastanov mode of nucleation and growth, while on SiC, characteristics of three-dimensional growth were evident. By contrast, AlN grew initially in a layer-by-layer mode. Deposition of GaN on vicinal (100) Beta-SiC during UV irradiation resulted in the formation of a new 4H polytype of this material. Deposition of BN via gas-source MBE on Cu(110) resulted in nanocrystalline cBN; films grown on (111) Cu resulted in h-BN (graphitic phase). Similar studies using Si(100) substrates also resulted in the occurrence of cBN. The occurrence of the cubic polytype was enhanced while that of h-BN was discouraged with the use of the UV light at 400-500 deg C.

  13. III-Nitride Dry Etching - Comparison of Inductively Coupled Plasma Chemistries

    SciTech Connect

    Abernathy, C.R.; Cho, H.; Donovan, S.M.; Hahn, Y-B.; Han, J.; Hays, D.C.; MacKenzie, J.D.; Pearton, S.J.; Shul, R.J.

    1998-11-10

    A systematic study of the etch characteristics of GaN, AlN and InN has been performed with boron halides- (BI{sub 3} and BBr{sub 3}) and interhalogen- (ICl and IBr) based Inductively Coupled Plasmas. Maximum etch selectivities of -100:1 were achieved for InN over both GaN and AlN in the BI{sub 3} mixtures due to the relatively high volatility of the InN etch products and the lower bond strength of InN. Maximum selectivies of- 14 for InN over GaN and >25 for InN over AlN were obtained with ICl and IBr chemistries. The etched surface morphologies of GaN in these four mixtures are similar or better than those of the control sample.

  14. 77 FR 74675 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... with the grant applications, the disclosure of which would constitute a clearly unwarranted invasion of... Inn, 3001 Cameron Blvd., Durham, NC 27705. Contact Person: Ruth Grossman, DDS, Scientific...

  15. 18. LOOKING SOUTH AT STEEPLY PITCHED, GABLED ROOF. THE UPPER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. LOOKING SOUTH AT STEEPLY PITCHED, GABLED ROOF. THE UPPER DORMERS PROVIDE LIGHT IN THE LOBBY AND THE LOWER DORMERS OPEN INTO SOME OF THE ORIGINAL GUEST ROOMS IN THE INN. (TAKEN FROM CHERRY- PICKER) - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  16. 2. Contextual view of building in setting, view to southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Contextual view of building in setting, view to southwest from slope above "Hayloft" Building (HABS-CA-2611-B), showing east side and north rear of building, State Highway 1 visible at left center. Scale stick visible on roof of building. - Deetjen's Big Sur Inn, Big Sur Inn Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  17. Making everyday tasks easier - arthritis

    MedlinePlus

    ... Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of Rheumatology . 9th ed. Philadelphia, PA: Elsevier ... Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of Rheumatology . 9th ed. Philadelphia, PA: Elsevier ...

  18. 17. Dining area of lobby/dining room, view to southsoutheast. Scale ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Dining area of lobby/dining room, view to south-southeast. Scale stick visible at left against corner of pillar; 5'10" figure for additional scale reference. - Deetjen's Big Sur Inn, Big Sur Inn Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  19. Clopidogrel Protects Endothelium by Hindering TNFα-Induced VCAM-1 Expression through CaMKKβ/AMPK/Nrf2 Pathway

    PubMed Central

    Yang, Huabing; Zhao, Pengjun; Tian, Shiliu

    2016-01-01

    Clopidogrel (INN), an oral antiplatelet drug, has been revealed to have a number of biological properties, for instance, anti-inflammation and antioxidation. Oxidative stress plays an imperative role in inflammation, diabetes mellitus, atherosclerosis, and cancer. In the present study, human aortic endothelial cells (HAECs) were employed to explore the anti-inflammatory activity of INN. INN reduced TNFα-induced reactive oxygen species (ROS) generation and time-dependently prompted the expression and activity of heme oxygenase 1 (HO-1). Cellular glutathione (GSH) levels were augmented by INN. shHO-1 blocked the INN suppression of TNFα-induced HL-60 cell adhesion. The CaMKKβ/AMPK pathway and Nrf2 transcriptional factor were implicated in the induction of HO-1 by INN. Additionally, TNFα dramatically augmented VCAM-1 expression at protein and mRNA levels. INN treatment strikingly repressed TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Compound C, an AMPK inhibitor, and shNrf2 abolished TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Our data suggest that INN diminishes TNFα-stimulated VCAM-1 expression at least in part via HO-1 induction, which is CaMKKβ/AMPK pathway-dependent. PMID:26824050

  20. 26. LOBBY, LOOKING NORTH TOWARD MAIN ENTRANCE FROM SECOND FLOOR. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. LOBBY, LOOKING NORTH TOWARD MAIN ENTRANCE FROM SECOND FLOOR. LOCAL LODGEPOLE PINE WHICH WAS VALUED FOR ITS INVARIABLE DIAMETER WAS USED TO CONSTRUCT THE COLUMNS AND BEAMS OF THE INN WHILE GNARLED OR DISEASED LOGS WERE SELECTED FOR THE BRACES AND BALUSTERS. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  1. 1. Historic American Buildings Survey, Copy of an eary photograph, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey, Copy of an eary photograph, courtesy of Montgomery County Historical Society, Norristown, Pa., THE KING OF PRUSSIA INN, c.1860-1870. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  2. 2. Historic American Buildings Survey, Copy of an eary photograph, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey, Copy of an eary photograph, courtesy of Montgomery County Historical Society, Norristown, Pa., THE KING OF PRUSSIA INN, c.1880. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  3. Clopidogrel Protects Endothelium by Hindering TNFα-Induced VCAM-1 Expression through CaMKKβ/AMPK/Nrf2 Pathway.

    PubMed

    Yang, Huabing; Zhao, Pengjun; Tian, Shiliu

    2016-01-01

    Clopidogrel (INN), an oral antiplatelet drug, has been revealed to have a number of biological properties, for instance, anti-inflammation and antioxidation. Oxidative stress plays an imperative role in inflammation, diabetes mellitus, atherosclerosis, and cancer. In the present study, human aortic endothelial cells (HAECs) were employed to explore the anti-inflammatory activity of INN. INN reduced TNFα-induced reactive oxygen species (ROS) generation and time-dependently prompted the expression and activity of heme oxygenase 1 (HO-1). Cellular glutathione (GSH) levels were augmented by INN. shHO-1 blocked the INN suppression of TNFα-induced HL-60 cell adhesion. The CaMKKβ/AMPK pathway and Nrf2 transcriptional factor were implicated in the induction of HO-1 by INN. Additionally, TNFα dramatically augmented VCAM-1 expression at protein and mRNA levels. INN treatment strikingly repressed TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Compound C, an AMPK inhibitor, and shNrf2 abolished TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Our data suggest that INN diminishes TNFα-stimulated VCAM-1 expression at least in part via HO-1 induction, which is CaMKKβ/AMPK pathway-dependent. PMID:26824050

  4. Something of Value: How Franchise Sellers Make Training Pay

    ERIC Educational Resources Information Center

    Berger, Gladys

    1975-01-01

    Training can be the most important benefit included in the purchase of a franchise. Several of these training programs used by franchise sellers (Castro Convertibles, Roto-Rooter, H and R Block, Dunhill Personnel Systems Inc., Carvel, Holiday Inns, Sheraton Inns Inc., McDonald's) are discussed. (Author/BP)

  5. Generic drug names and social welfare.

    PubMed

    Lobo, Félix; Feldman, Roger

    2013-06-01

    This article studies how well International Nonproprietary Names (INNs), the "generic" names for pharmaceuticals, address the problems of imperfect information. Left in private hands, the identification of medicines leads to confusion and errors. Developed in the 1950s by the World Health Organization, INNs are a common, global, scientific nomenclature designed to overcome this failure. Taking stock after sixty years, we argue that the contribution of INNs to social welfare is paramount. They enhance public health by reducing errors and improving patient safety. They also contribute to economic efficiency by creating transparency as the foundation of competitive generic drug markets, reducing transaction costs, and favoring trade. The law in most countries requires manufacturers to designate pharmaceuticals with INNs in labeling and advertising. Generic substitution is also permitted or mandatory in many countries. But not all the benefits of INNs are fully realized because prescribers may not use them. We advocate strong incentives or even legally binding provisions to extend the use of INNs by prescribing physicians and dispensing pharmacists, but we do not recommend replacing brand names entirely with INNs. Instead, we propose dual use of brand names and INNs in prescribing, as in drug labeling.

  6. 34. THE CROW'S NEST. IN THE EARLY YEARS OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. THE CROW'S NEST. IN THE EARLY YEARS OF THE INN MUSICIANS SAT AND PLAYED FOR THE GUESTS IN THE LOBBY BELOW. THE EARTHQUAKE IN 1959 CAUSED SOME STRUCTURAL DAMAGE AND NOW THE CROW'S NEST IS NOT ACCESSIBLE TO THE PUBLIC. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  7. Inductively Coupled Plasma Etching of III-Nitrides in Cl(2)/Xe,Cl(2)/Ar and Cl(2)/He

    SciTech Connect

    Abernathy, C.R.; Cho, H.; Donovan, S.M.; Hahn, Y.B.; Hays, D.C.; Jung, K.B.; Pearton, S.J.; Shul, R.J.

    1999-01-05

    The role of additive noble gases He, Ar and Xe to C&based Inductively Coupled Plasmas for etching of GaN, AIN and InN were examined. The etch rates were a strong function of chlorine concentration, rf chuck power and ICP source power. The highest etch rates for InN were obtained with C12/Xe, while the highest rates for AIN and GaN were obtained with C12/He. Efficient breaking of the 111-nitrogen bond is crucial for attaining high etch rates. The InN etching was dominated by physical sputtering, in contrast to GaN and AIN. In the latter cases, the etch rates were limited by initial breaking of the III-nitrogen bond. Maximum selectivities of -80 for InN to GaN and InN to AIN were obtained.

  8. Mechanisms of 1D crystal growth in reactive vapor transport: indium nitride nanowires.

    PubMed

    Vaddiraju, Sreeram; Mohite, Aditya; Chin, Alan; Meyyappan, M; Sumanasekera, Gamini; Alphenaar, Bruce W; Sunkara, Mahendra K

    2005-08-01

    Indium nitride (InN) nanowire synthesis using indium (In) vapor transport in a dissociated ammonia environment (reactive vapor transport) is studied in detail to understand the nucleation and growth mechanisms involved with the so-called "self-catalysis" schemes. The results show that the nucleation of InN crystal occurs first on the substrate. Later, In droplets are formed on top of the InN crystals because of selective wetting of In onto InN crystals. Further growth via liquid-phase epitaxy through In droplets leads the growth in one dimension (1D), resulting in the formation of InN nanowires. The details about the nucleation and growth aspects within these self-catalysis schemes are rationalized further by demonstrating the growth of heteroepitaxially oriented nanowire arrays on single-crystal substrates and "tree-like" morphologies on a variety of substrates. However, the direct nitridation of In droplets using dissociated ammonia results in the spontaneous nucleation and basal growth of nanowires directly from the In melt surface, which is quite different from the above-mentioned nucleation mechanism with the reactive vapor transport case. The InN nanowires exhibit a band gap of 0.8 eV, whereas the mixed phase of InN and In(2)O(3) nanowires exhibit a peak at approximately 1.9 eV in addition to that at 0.8 eV.

  9. An InN/InGaN Quantum Dot Electrochemical Biosensor for Clinical Diagnosis

    PubMed Central

    Alvi, Naveed ul Hassan; Gómez, Victor J.; Rodriguez, Paul E.D. Soto; Kumar, Praveen; Zaman, Saima; Willander, Magnus; Nötzel, Richard

    2013-01-01

    Low-dimensional InN/InGaN quantum dots (QDs) are demonstrated for realizing highly sensitive and efficient potentiometric biosensors owing to their unique electronic properties. The InN QDs are biochemically functionalized. The fabricated biosensor exhibits high sensitivity of 97 mV/decade with fast output response within two seconds for the detection of cholesterol in the logarithmic concentration range of 1 × 10−6 M to 1 × 10−3 M. The selectivity and reusability of the biosensor are excellent and it shows negligible response to common interferents such as uric acid and ascorbic acid. We also compare the biosensing properties of the InN QDs with those of an InN thin film having the same surface properties, i.e., high density of surface donor states, but different morphology and electronic properties. The sensitivity of the InN QDs-based biosensor is twice that of the InN thin film-based biosensor, the EMF is three times larger, and the response time is five times shorter. A bare InGaN layer does not produce a stable response. Hence, the superior biosensing properties of the InN QDs are governed by their unique surface properties together with the zero-dimensional electronic properties. Altogether, the InN QDs-based biosensor reveals great potential for clinical diagnosis applications. PMID:24132228

  10. Closely Spaced MEG Source Localization and Functional Connectivity Analysis Using a New Prewhitening Invariance of Noise Space Algorithm.

    PubMed

    Zhang, Junpeng; Cui, Yuan; Deng, Lihua; He, Ling; Zhang, Junran; Zhang, Jing; Zhou, Qun; Liu, Qi; Zhang, Zhiguo

    2016-01-01

    This paper proposed a prewhitening invariance of noise space (PW-INN) as a new magnetoencephalography (MEG) source analysis method, which is particularly suitable for localizing closely spaced and highly correlated cortical sources under real MEG noise. Conventional source localization methods, such as sLORETA and beamformer, cannot distinguish closely spaced cortical sources, especially under strong intersource correlation. Our previous work proposed an invariance of noise space (INN) method to resolve closely spaced sources, but its performance is seriously degraded under correlated noise between MEG sensors. The proposed PW-INN method largely mitigates the adverse influence of correlated MEG noise by projecting MEG data to a new space defined by the orthogonal complement of dominant eigenvectors of correlated MEG noise. Simulation results showed that PW-INN is superior to INN, sLORETA, and beamformer in terms of localization accuracy for closely spaced and highly correlated sources. Lastly, source connectivity between closely spaced sources can be satisfactorily constructed from source time courses estimated by PW-INN but not from results of other conventional methods. Therefore, the proposed PW-INN method is a promising MEG source analysis to provide a high spatial-temporal characterization of cortical activity and connectivity, which is crucial for basic and clinical research of neural plasticity.

  11. Attitudes of physicians and pharmacists towards International Non-proprietary Name prescribing in Belgium.

    PubMed

    Van Bever, Elien; Elseviers, Monique; Plovie, Marijke; Vandeputte, Lieselot; Van Bortel, Luc; Vander Stichele, Robert

    2015-03-01

    International Non-proprietary Name (INN) prescribing is the use of the name of the active ingredient(s) instead of the brand name for prescribing. In Belgium, INN prescribing began in 2005 and a major policy change occurred in 2012. The aim was to explore the opinions of Dutch-speaking general practitioners (GPs) and pharmacists. An electronic questionnaire with 39 five-point Likert scale statements and one open question was administered in 2013. Multivariate analysis was performed with multiple linear regression on a sum score for benefit statements and for drawback statements. Answers to the open question were qualitatively analysed. We received 745 valid responses with a representable sample for both subgroups. Participants perceived the motives to introduce INN prescribing as purely economic (to reduce pharmaceutical expenditures for the government and the patient). Participants accepted the concept of INN prescribing, but 88% stressed the importance of guaranteed treatment continuity, especially in older, chronic patients, to prevent patient confusion, medication non-adherence and erroneous drug use. In conclusion, the current way in which INN prescribing is applied in Belgium leads to many concerns among primary health professionals about patient confusion and medication adherence. Slightly adapting the current concept of INN prescribing to these concerns can turn INN prescribing into one of the major policies in Belgium to reduce pharmaceutical expenditures and to stimulate rational drug prescribing. PMID:25155133

  12. Closely Spaced MEG Source Localization and Functional Connectivity Analysis Using a New Prewhitening Invariance of Noise Space Algorithm

    PubMed Central

    Zhang, Junpeng; Cui, Yuan; Deng, Lihua; He, Ling; Zhang, Junran; Zhang, Jing; Zhou, Qun; Liu, Qi; Zhang, Zhiguo

    2016-01-01

    This paper proposed a prewhitening invariance of noise space (PW-INN) as a new magnetoencephalography (MEG) source analysis method, which is particularly suitable for localizing closely spaced and highly correlated cortical sources under real MEG noise. Conventional source localization methods, such as sLORETA and beamformer, cannot distinguish closely spaced cortical sources, especially under strong intersource correlation. Our previous work proposed an invariance of noise space (INN) method to resolve closely spaced sources, but its performance is seriously degraded under correlated noise between MEG sensors. The proposed PW-INN method largely mitigates the adverse influence of correlated MEG noise by projecting MEG data to a new space defined by the orthogonal complement of dominant eigenvectors of correlated MEG noise. Simulation results showed that PW-INN is superior to INN, sLORETA, and beamformer in terms of localization accuracy for closely spaced and highly correlated sources. Lastly, source connectivity between closely spaced sources can be satisfactorily constructed from source time courses estimated by PW-INN but not from results of other conventional methods. Therefore, the proposed PW-INN method is a promising MEG source analysis to provide a high spatial-temporal characterization of cortical activity and connectivity, which is crucial for basic and clinical research of neural plasticity. PMID:26819768

  13. Thermally detected optical absorption in sophisticated nitride structures

    NASA Astrophysics Data System (ADS)

    Vasson, A.; Shubina, T. V.; Leymarie, J.

    2005-02-01

    The thermally detected optical absorption (TDOA) is applied to elucidate peculiarities of absorption in nitride structures of unusual morphology like GaN nanocolumns or InN layers with various imperfections. A study of GaN structures permits us to establish position of an absorption edge in TDOA spectra. We demonstrate that the absorption edge is different in GaN regions of opposite polarities. In InN with metallic In inclusions, this technique enable separation of InN interband absorption and extinction related to the Mie resonances, if the latter are below the principal absorption edge.

  14. 28. LOBBY, LOOKING EAST FROM THE THIRD FLOOR. THE OBELISK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. LOBBY, LOOKING EAST FROM THE THIRD FLOOR. THE OBELISK SHAPED FIREPLACE IS FULLY VISIBLE AT THE RIGHT. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  15. 78 FR 52505 - Mid-Atlantic Fishery Management Council; Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ... will be held at the Inn at Henderson's Wharf, 1000 Fell Street, Baltimore, MD 21231; telephone: (410..., scup, and black sea bass fisheries. Multi-year ACTs and management measures, applicable to...

  16. Chemical Reactions at Surfaces. Final Progress Report

    SciTech Connect

    2003-02-21

    The Gordon Research Conference (GRC) on Chemical Reactions at Surfaces was held at Holiday Inn, Ventura, California, 2/16-21/03. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  17. 6. Historic American Buildings Survey (Fed.) Stanley P. Mixon, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Historic American Buildings Survey (Fed.) Stanley P. Mixon, Photographer Sept 16, 1940 (F) EXTERIOR, DETAIL OF OLD TAVERN SIGN (AMERICAN SIDE) EAGLE - Captain Arah Phelphs Inn, Colebrook, Litchfield County, CT

  18. Burn Institute

    MedlinePlus

    ... 3 & 15, 2016 RB Inn Golf Course & Del Mar Fairgrounds Firefighter Boot Drive March 2017 Across San ... Banquet May 2017 Demolition Derby June 2017 Del Mar Fairgrounds News Survivor Stories 2016 Firework Safety ALL ...

  19. 6. Historic American Buildings Survey Robert W. Kerrigan, Photographer August ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Historic American Buildings Survey Robert W. Kerrigan, Photographer August 24, 1936 INTERIOR DETAIL WEST WALL OF SOCIAL HALL - Trocadero Inn, Sigmund Stern Grove, San Francisco, San Francisco County, CA

  20. 4. Historic American Buildings Survey (Fed.) Stanley P. Mixon, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey (Fed.) Stanley P. Mixon, Photographer Sept 16, 1940 (D) INTERIOR, PANELED WALL IN OLD TAP ROOM, SHOWING BAR IN FURTHER CORNER - Captain Arah Phelphs Inn, Colebrook, Litchfield County, CT

  1. 76 FR 4895 - Workshop To Discuss Issues Related to the Potential Development of Multipollutant Science and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-27

    ... Inn, 211 Pittsboro Street, Chapel Hill, NC 27516. The EPA contractor, ICF International, Inc., is... information, registration, and logistics for the workshop should be directed to Courtney Skuce at...

  2. Synovial fluid analysis

    MedlinePlus

    Joint fluid analysis; Joint fluid aspiration ... El-Gabalawy HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of ...

  3. 7. Historic American Buildings Survey (Fed.) Stanley P. Mixon, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey (Fed.) Stanley P. Mixon, Photographer Sept 16, 1940 (G) EXTERIOR, DETAIL OF OLD TAVERN SIGN (ENGLISH SIDE) WITH PAINTED LION - Captain Arah Phelphs Inn, Colebrook, Litchfield County, CT

  4. 76 FR 30176 - Dermatologic and Ophthalmic Drugs Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-24

    ... Marriott Inn and Conference Center, University of Maryland University College (UMUC), 3501 University Blvd... attendance of the public at its advisory committee meetings and will make every effort to accommodate...

  5. 7. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 SOUTH (FRONT) ELEVATION. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  6. 14. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 INTERIOR DETAIL, SOUTHEAST BEDROOM. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  7. 4. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 SOUTHWEST ELEVATION. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  8. 3. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 NORTHEAST ELEVATION. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  9. 10. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 MANTEL (NOT ORIGINAL) SOUTHEAST PARLOR. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  10. 38. DINING ROOM, THE CHIMNEY WAS SEVERELY DAMAGED BY AN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. DINING ROOM, THE CHIMNEY WAS SEVERELY DAMAGED BY AN EARTHQUAKE IN 1959 AND HAD TO BE RECONSTRUCTED. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  11. 77 FR 41192 - Eunice Kennedy Shriver National Institute of Child Health & Human Development; Notice of Closed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ..., (Formerly Holiday inn Select), 8120 Wisconsin Avenue, Bethesda, MD 20814. Contact Person: David H. Weinberg..., 301-435-6973, David.Weinberg@nih.gov . (Catalogue of Federal Domestic Assistance Program Nos....

  12. 77 FR 69638 - Eunice Kennedy Shriver National Institute of Child Health & Human Development; Notice of Closed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ...: The Holiday Inn Express, 1775 Rockville Pike, Rockville, MD 20852. Contact Person: David H. Weinberg..., 301-435-6973, David.Weinberg@nih.gov . (Catalogue of Federal Domestic Assistance Program Nos....

  13. 7. Historic American Buildings Survey, Arthur C. Haskell, Photographer. Oct. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey, Arthur C. Haskell, Photographer. Oct. 1937. (h) Int- Old Bar in Basement Tap Room - Old Tavern Inn, Wareham Street (State Route 28), Middleboro, Plymouth County, MA

  14. View southwest of "New Room" taken from doorway; windows overlook ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View southwest of "New Room" taken from doorway; windows overlook Castro Creek Canyon. Scale visible against end wall - Deetjen's Big Sur Inn, Antique Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  15. 78 FR 58547 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-24

    ... applications. Place: Holiday Inn Inner Harbor, 301 W. Lombard Street, Baltimore, MD 21201. Contact Person...-93.878, 93.892, 93.893, National Institutes of Health, HHS) Dated: September 18, 2013. David...

  16. 10. GENERAL VIEW OF 'BIG RAILWAY' SHOWING CRADLE AND WINCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. GENERAL VIEW OF 'BIG RAILWAY' SHOWING CRADLE AND WINCH MANUFACTURED BY MEAD-MORRISON MANUFACTURING COMPANY, HAVING A 450 TON CAPACITY - Anderson-Christofani Shipyard, Innes Avenue & Griffith Street, San Francisco, San Francisco County, CA

  17. 18. Photocopy of photograph (original print at Riverside Library, Local ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Photocopy of photograph (original print at Riverside Library, Local History Collection), photographer and date unknown. VIEW OF MISSION INN, SEVENTH STREET ENTRANCE - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  18. 75 FR 23288 - Notice of Public Meeting, Southwest Colorado Resource Advisory Council Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ... will be held on June 4, 2010, in Dolores, Colorado; August 13, 2010, in Gunnison, Colorado; and October... 184, Dolores, Colorado 81323; August 13, 2010, at the Holiday Inn Express at 910 E. Tomichi,...

  19. 75 FR 54598 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ...: Need for Correction In the Federal Register of May 28, 2010, in FR Doc. 2010-12919, on page 29992, in..., 2010, to be held at the same time and location, 9 a.m. to 5 p.m., Comfort Inn (UNC Wilmington), 151... 3. September 9, 2010, from 9 a.m. - 5 p.m., Comfort Inn (UNC- Wilmington), 151 South College...

  20. Brief History of Moot Court: Britain and U.S.

    ERIC Educational Resources Information Center

    Rachid, Mohamed; Knerr, Charles R.

    This document presents a history of moot court, defined as a mock court where hypothetical cases are tried for the training of law students. The first recorded reference to a moot court was in the year 997, and moots were common at the Inns of Court and Chancery in 14th century England. In 18th century England there were 4 greater Inns of Court…

  1. Solar hot water system installed at Las Vegas, Nevada

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A solar energy hot water system installed in a motor inn at Las Vegas, Nevada is described. The inn is a three story building with a flat roof for installation of the solar panels. The system consists of 1,200 square feet of liquid flat plate collectors, a 2,500 gallon insulated vertical steel storage tank, two heat exchangers, and pumps and controls. The system was designed to supply approximately 74 percent of the total hot water load.

  2. Crystallographic analysis of human hemoglobin elucidates the structural basis of the potent and dual antisickling activity of pyridyl derivatives of vanillin

    SciTech Connect

    Abdulmalik, Osheiza; Ghatge, Mohini S.; Musayev, Faik N.; Parikh, Apurvasena; Chen, Qiukan; Yang, Jisheng; Nnamani, Ijeoma; Danso-Danquah, Richmond; Eseonu, Dorothy N.; Asakura, Toshio; Abraham, Donald J.; Venitz, Jurgen; Safo, Martin K.

    2011-11-01

    Pyridyl derivatives of vanillin increase the fraction of the more soluble oxygenated sickle hemoglobin and/or directly increase the solubility of deoxygenated sickle hemoglobin. Crystallographic analysis reveals the structural basis of the potent and dual antisickling activity of these derivatives. Vanillin has previously been studied clinically as an antisickling agent to treat sickle-cell disease. In vitro investigations with pyridyl derivatives of vanillin, including INN-312 and INN-298, showed as much as a 90-fold increase in antisickling activity compared with vanillin. The compounds preferentially bind to and modify sickle hemoglobin (Hb S) to increase the affinity of Hb for oxygen. INN-312 also led to a considerable increase in the solubility of deoxygenated Hb S under completely deoxygenated conditions. Crystallographic studies of normal human Hb with INN-312 and INN-298 showed that the compounds form Schiff-base adducts with the N-terminus of the α-subunits to constrain the liganded (or relaxed-state) Hb conformation relative to the unliganded (or tense-state) Hb conformation. Interestingly, while INN-298 binds and directs its meta-positioned pyridine-methoxy moiety (relative to the aldehyde moiety) further down the central water cavity of the protein, that of INN-312, which is ortho to the aldehyde, extends towards the surface of the protein. These studies suggest that these compounds may act to prevent sickling of SS cells by increasing the fraction of the soluble high-affinity Hb S and/or by stereospecific inhibition of deoxygenated Hb S polymerization.

  3. Field-effect transistors based on cubic indium nitride

    PubMed Central

    Oseki, Masaaki; Okubo, Kana; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2014-01-01

    Although the demand for high-speed telecommunications has increased in recent years, the performance of transistors fabricated with traditional semiconductors such as silicon, gallium arsenide, and gallium nitride have reached their physical performance limits. Therefore, new materials with high carrier velocities should be sought for the fabrication of next-generation, ultra-high-speed transistors. Indium nitride (InN) has attracted much attention for this purpose because of its high electron drift velocity under a high electric field. Thick InN films have been applied to the fabrication of field-effect transistors (FETs), but the performance of the thick InN transistors was discouraging, with no clear linear-saturation output characteristics and poor on/off current ratios. Here, we report the epitaxial deposition of ultrathin cubic InN on insulating oxide yttria-stabilized zirconia substrates and the first demonstration of ultrathin-InN-based FETs. The devices exhibit high on/off ratios and low off-current densities because of the high quality top and bottom interfaces between the ultrathin cubic InN and oxide insulators. This first demonstration of FETs using a ultrathin cubic indium nitride semiconductor will thus pave the way for the development of next-generation high-speed electronics. PMID:24492240

  4. Field-effect transistors based on cubic indium nitride.

    PubMed

    Oseki, Masaaki; Okubo, Kana; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2014-02-04

    Although the demand for high-speed telecommunications has increased in recent years, the performance of transistors fabricated with traditional semiconductors such as silicon, gallium arsenide, and gallium nitride have reached their physical performance limits. Therefore, new materials with high carrier velocities should be sought for the fabrication of next-generation, ultra-high-speed transistors. Indium nitride (InN) has attracted much attention for this purpose because of its high electron drift velocity under a high electric field. Thick InN films have been applied to the fabrication of field-effect transistors (FETs), but the performance of the thick InN transistors was discouraging, with no clear linear-saturation output characteristics and poor on/off current ratios. Here, we report the epitaxial deposition of ultrathin cubic InN on insulating oxide yttria-stabilized zirconia substrates and the first demonstration of ultrathin-InN-based FETs. The devices exhibit high on/off ratios and low off-current densities because of the high quality top and bottom interfaces between the ultrathin cubic InN and oxide insulators. This first demonstration of FETs using a ultrathin cubic indium nitride semiconductor will thus pave the way for the development of next-generation high-speed electronics.

  5. III-V nitrides and performance of graphene on copper plasmonic biosensor

    NASA Astrophysics Data System (ADS)

    Mohanty, Goutam; Sahoo, Bijaya Kumar

    2016-05-01

    In the present study, the influence of iii-v nitrides as well as Ge and Si on the sensitivity and performance of a graphene protected copper plasmonic biosensor has been investigated. These semiconductors have been used between copper (Cu) and graphene layers on a SF 10 glass prism. The sensitivity and performance of the biosensor has been computed for with and without semiconductors. III-V nitrides demonstrated high sensitivity and high figure of merit (FOM) in comparison to Si and Ge due to their superior electronic and optical properties. The enhancement of evanescent electric field due to Si, Ge, AlN, GaN and InN have been computed and found highest enhancement for InN. This happens due to high refractive index of InN than other semiconductors. Analysis shows that for a high sensitive imaging biosensor the required optimal thickness of copper, InN and graphene are respectively 32 nm, 13 nm and 0.34 nm for light of wavelength λ = 633 nm (red Hesbnd Ne laser). This study suggests that InN would be a better choice for fabrication of new imaging plasmonic biosensors for chemical and biological sensing.

  6. Growth mechanism, structure and IR photoluminescence studies of indium nitride nanorods

    NASA Astrophysics Data System (ADS)

    Lan, Z. H.; Wang, W. M.; Sun, C. L.; Shi, S. C.; Hsu, C. W.; Chen, T. T.; Chen, K. H.; Chen, C. C.; Chen, Y. F.; Chen, L. C.

    2004-08-01

    High-quality single crystal indium nitride nanorods were grown on Si substrates by catalytic chemical vapor deposition. Both Raman and high resolution transmission electron microscopic analyses suggested that even a minute amount of oxygen, from the residual oxygen in the growth environment and/or native oxide on the Si, would effectively help the growth of InN nanorods. The In 2O 3 formed on Au nanoparticles helped dissolve nitrogen as a catalyst with the subsequent growth of InN nanorods. Variations in the apparent color and photoluminescence (PL) spectra of the InN nanorods were observed. For the optically brown InN nanorods that exhibited diameters in the range of 30-50 nm, the PL study showed a peak at 1.9 eV, the possible origins of which are discussed. In contrast, for the optically black InN nanorods that exhibited diameters in the range of 50-100 nm, the PL peak at approximately 0.766 eV measured at 20 K was attributed to band edge emission.

  7. Indium nitride: A narrow gap semiconductor

    SciTech Connect

    Wu, J.; Walukiewicz, W.; Yu, K.M.; Ager III, J.W.; Haller, E.E.; Lu, H.; Schaff, W.J.

    2002-08-14

    The optical properties of wurtzite InN grown on sapphire substrates by molecular-beam epitaxy have been characterized by optical absorption, photoluminescence, and photomodulated reflectance techniques. All these three characterization techniques show an energy gap for InN between 0.7 and 0.8 eV, much lower than the commonly accepted value of 1.9 eV. The photoluminescence peak energy is found to be sensitive to the free electron concentration of the sample. The peak energy exhibits a very weak hydrostatic pressure dependence and a small, anomalous blueshift with increasing temperature. The bandgap energies of In-rich InGaN alloys were found to be consistent with the narrow gap of InN. The bandgap bowing parameter was determined to be 1.43 eV in InGaN.

  8. Surface-plasmon resonances in indium nitride with metal-enriched nano-particles

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Plotnikov, D. S.; Vasson, A.; Leymarie, J.; Larsson, M.; Holtz, P. O.; Monemar, B.; Lu, Hai; Schaff, W. J.; Kop'ev, P. S.

    2006-03-01

    Plasmonic resonances in In-enriched nano-particles, spontaneously formed during growth, can dramatically modify optical properties of InN. Experimental support for this is provided from detailed studies of absorption and infrared emission in InN. In particular, thermally detected optical absorption and photoluminescence excitation spectroscopy reveal a peak below the region of strong absorption in InN. A higher-energy part of the infrared emission having a noticeable p-polarization is markedly enhanced with excitation along the surface. These peculiarities are discussed in terms of the Mie resonances, arising in metallic spheroids with different aspect ratio, and their coupling with recombining states, whose strength depends on energy separation between the states and the resonances.

  9. Advanced Computational Modeling of Vapor Deposition in a High-Pressure Reactor

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.; Moore, Craig E.; McCall, Sonya D.; Cardelino, Carlos A.; Dietz, Nikolaus; Bachmann, Klaus

    2004-01-01

    In search of novel approaches to produce new materials for electro-optic technologies, advances have been achieved in the development of computer models for vapor deposition reactors in space. Numerical simulations are invaluable tools for costly and difficult processes, such as those experiments designed for high pressures and microgravity conditions. Indium nitride is a candidate compound for high-speed laser and photo diodes for optical communication system, as well as for semiconductor lasers operating into the blue and ultraviolet regions. But InN and other nitride compounds exhibit large thermal decomposition at its optimum growth temperature. In addition, epitaxy at lower temperatures and subatmospheric pressures incorporates indium droplets into the InN films. However, surface stabilization data indicate that InN could be grown at 900 K in high nitrogen pressures, and microgravity could provide laminar flow conditions. Numerical models for chemical vapor deposition have been developed, coupling complex chemical kinetics with fluid dynamic properties.

  10. Advanced Computational Modeling of Vapor Deposition in a High-pressure Reactor

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.; Moore, Craig E.; McCall, Sonya D.; Cardelino, Carlos A.; Dietz, Nikolaus; Bachmann, Klaus

    2004-01-01

    In search of novel approaches to produce new materials for electro-optic technologies, advances have been achieved in the development of computer models for vapor deposition reactors in space. Numerical simulations are invaluable tools for costly and difficult processes, such as those experiments designed for high pressures and microgravity conditions. Indium nitride is a candidate compound for high-speed laser and photo diodes for optical communication system, as well as for semiconductor lasers operating into the blue and ultraviolet regions. But InN and other nitride compounds exhibit large thermal decomposition at its optimum growth temperature. In addition, epitaxy at lower temperatures and subatmospheric pressures incorporates indium droplets into the InN films. However, surface stabilization data indicate that InN could be grown at 900 K in high nitrogen pressures, and microgravity could provide laminar flow conditions. Numerical models for chemical vapor deposition have been developed, coupling complex chemical kinetics with fluid dynamic properties.

  11. Pressure dependence of the refractive index in wurtzite and rocksalt indium nitride

    SciTech Connect

    Oliva, R.; Yamaguchi, T.; Nanishi, Y.

    2014-12-08

    We have performed high-pressure Fourier transform infrared reflectance measurements on a freestanding InN thin film to determine the refractive index of wurtzite InN and its high-pressure rocksalt phase as a function of hydrostatic pressure. From a fit to the experimental refractive-index curves including the effect of the high-energy optical gaps, phonons, free carriers, and the direct (fundamental) band-gap in the case of wurtzite InN, we obtain pressure coefficients for the low-frequency (electronic) dielectric constant ε{sub ∞}. Negative pressure coefficients of −8.8 × 10{sup −2 }GPa{sup −1} and −14.8 × 10{sup −2 }GPa{sup −1} are obtained for the wurtzite and rocksalt phases, respectively. The results are discussed in terms of the electronic band structure and the compressibility of both phases.

  12. [Development of the database on nonproprietary names of drugs].

    PubMed

    Hashiba, S; Takenaka, Y; Nakadate, M

    1989-01-01

    This paper describes the outline of the database of nonproprietary names of drugs and the characteristics of its online search system. The database includes the records of officially authorized names by WHO, International Nonproprietary Names (INN), and those by Japanese Government, Japanese Accepted Names (JAN). The INN file is merged with the JAN file. The online retrieval system is designed to enable search for drugs by generic names adopted on an international level and a national level in both English and Japanese. It is operated with INQ (DBMS) in the NEC ACOS-6 computer. Data from INN are updated once a year, and those from JAN are added whenever the official announcement of newly approved drugs are published in Yakumu-Koho (official pharmaceutical gazette). PMID:2636918

  13. An analytical model of anisotropic low-field electron mobility in wurtzite indium nitride

    NASA Astrophysics Data System (ADS)

    Wang, Shulong; Liu, Hongxia; Song, Xin; Guo, Yulong; Yang, Zhaonian

    2014-03-01

    This paper presents a theoretical analysis of anisotropic transport properties and develops an anisotropic low-field electron analytical mobility model for wurtzite indium nitride (InN). For the different effective masses in the Γ-A and Γ-M directions of the lowest valley, both the transient and steady state transport behaviors of wurtzite InN show different transport characteristics in the two directions. From the relationship between velocity and electric field, the difference is more obvious when the electric field is low in the two directions. To make an accurate description of the anisotropic transport properties under low field, for the first time, we present an analytical model of anisotropic low-field electron mobility in wurtzite InN. The effects of different ionized impurity scattering models on the low-field mobility calculated by Monte Carlo method (Conwell-Weisskopf and Brooks-Herring method) are also considered.

  14. Self-annihilation of inversion domains by high energy defects in III-Nitrides

    SciTech Connect

    Koukoula, T.; Kioseoglou, J. Kehagias, Th.; Komninou, Ph.; Ajagunna, A. O.; Georgakilas, A.

    2014-04-07

    Low-defect density InN films were grown on Si(111) by molecular beam epitaxy over an ∼1 μm thick GaN/AlN buffer/nucleation layer. Electron microscopy observations revealed the presence of inverse polarity domains propagating across the GaN layer and terminating at the sharp GaN/InN (0001{sup ¯}) interface, whereas no inversion domains were detected in InN. The systematic annihilation of GaN inversion domains at the GaN/InN interface is explained in terms of indium incorporation on the Ga-terminated inversion domains forming a metal bonded In-Ga bilayer, a structural instability known as the basal inversion domain boundary, during the initial stages of InN growth on GaN.

  15. The Discovery of the Nearest Star

    NASA Astrophysics Data System (ADS)

    Glass, I. S.

    2007-07-01

    Proxima Centauri, the closest star to us after the Sun, is part of a triple system whose other two members constitute the double ? Centauri. In the 1830s, the latter was the subject of the first successful stellar parallax measure ments made in Cape Town by Thomas Henderson. Proxima was found in 1915, at the Union Observatory in Johannesburg by R T A Innes, as a faint star with a high proper motion similar to that of ? Cen. Its parallax was measured independently over the following two years by J G E G Vote at the Cape and by Innes himself, unknown to each other. Innes, on the basis of his rather rough result, declared it to be closer than ? and named it 'Proxima Centauri', but the truth of its proximity was only established rigorously in 1928 by H A Alden, based on observations at the Yale Southern Station in Johannesburg.

  16. Nanobranched porous palladium-tin intermetallics: One-step synthesis and their superior electrocatalysis towards formic acid oxidation

    NASA Astrophysics Data System (ADS)

    Sun, Dandan; Si, Ling; Fu, Gengtao; Liu, Chang; Sun, Dongmei; Chen, Yu; Tang, Yawen; Lu, Tianhong

    2015-04-01

    Nanocrystalline intermetallics in bulk with high surface area hold enormous promise as an efficient catalyst for real fuel cell applications due to their unique electrocatalytic properties. In this work, a novel three-dimensional (3D) porous Pd-Sn intermetallics in network nanostructures (Pd-Sn-INNs) has been fabricated at relatively low temperature for the first time by one-step ethylene glycol-assisted hydrothermal reduction method. The structure characteristics of the Pd-Sn-INNs are confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), selected-area electron diffraction (SAED), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The as-prepared 3D Pd-Sn-INNs exhibit remarkably improved electrocatalytic activity and stability towards formic acid oxidation reaction (FAOR) over commercially available Pd black.

  17. Patient Safety in Medication Nomenclature: Orthographic and Semantic Properties of International Nonproprietary Names

    PubMed Central

    Bryan, Rachel; Aronson, Jeffrey K.; ten Hacken, Pius; Williams, Alison; Jordan, Sue

    2015-01-01

    Background Confusion between look-alike and sound-alike (LASA) medication names (such as mercaptamine and mercaptopurine) accounts for up to one in four medication errors, threatening patient safety. Error reduction strategies include computerized physician order entry interventions, and ‘Tall Man’ lettering. The purpose of this study is to explore the medication name designation process, to elucidate properties that may prime the risk of confusion. Methods and Findings We analysed the formal and semantic properties of 7,987 International Non-proprietary Names (INNs), in relation to naming guidelines of the World Health Organization (WHO) INN programme, and have identified potential for errors. We explored: their linguistic properties, the underlying taxonomy of stems to indicate pharmacological interrelationships, and similarities between INNs. We used Microsoft Excel for analysis, including calculation of Levenshtein edit distance (LED). Compliance with WHO naming guidelines was inconsistent. Since the 1970s there has been a trend towards compliance in formal properties, such as word length, but longer names published in the 1950s and 1960s are still in use. The stems used to show pharmacological interrelationships are not spelled consistently and the guidelines do not impose an unequivocal order on them, making the meanings of INNs difficult to understand. Pairs of INNs sharing a stem (appropriately or not) often have high levels of similarity (<5 LED), and thus have greater potential for confusion. Conclusions We have revealed a tension between WHO guidelines stipulating use of stems to denote meaning, and the aim of reducing similarities in nomenclature. To mitigate this tension and reduce the risk of confusion, the stem system should be made clear and well ordered, so as to avoid compounding the risk of confusion at the clinical level. The interplay between the different WHO INN naming principles should be further examined, to better understand their

  18. Solar domestic hot water system installed at Texas City, Texas

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This is the final technical report of the solar energy system located at LaQuinta Motor Inn, Texas City, Texas. The system was designed to supply 63 percent of the total hot water load for a new 98 unit motor inn. The solar energy system consists of a 2100 square feet Raypack liquid flat plate collector subsystem and a 2500 gallon storage subsystem circulating hot water producing 3.67 x 10 to the 8th power Btu/year. Abstracts from the site files, specification references, drawings, installation, operation, and maintenance instructions are included.

  19. Solar domestic hot water system installed at Texas City, Texas

    NASA Astrophysics Data System (ADS)

    1980-12-01

    This is the final technical report of the solar energy system located at LaQuinta Motor Inn, Texas City, Texas. The system was designed to supply 63 percent of the total hot water load for a new 98 unit motor inn. The solar energy system consists of a 2100 square feet Raypack liquid flat plate collector subsystem and a 2500 gallon storage subsystem circulating hot water producing 3.67 x 10 to the 8th power Btu/year. Abstracts from the site files, specification references, drawings, installation, operation, and maintenance instructions are included.

  20. Near infrared electroluminescence from n-InN/p-NiO/GaN light-emitting diode fabricated by PAMBE

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Wang, Hui; Zhuang, Shiwei; Wu, Guoguang; Leng, Jiyan; Li, Wancheng; Gao, Fubin; Zhang, Baolin; Du, Guotong

    2016-07-01

    The n-InN/p-NiO/GaN heterojunction was fabricated by using plasma-assisted molecular beam epitaxy (PAMBE) combined with radio frequency magnetron sputtering. The device exhibited typical rectification characteristic with a turn-on voltage of ~1.5 V. Under forward bias, a dominant near infrared emission (NIR) peaked around 1565 nm was detected at room temperature. The NIR emission was attributed to the band-edge emission of InN film according to the photoluminescence spectrum of InN layer. Furthermore, the mechanism of the current transport and light emission was tentatively discussed in terms of the band diagrams of the heterojunction.

  1. 2009 Analysis Platform Review Report

    SciTech Connect

    Ferrell, John

    2009-12-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the U.S. Department of Energy Biomass Program’s Analysis platform review meeting, held on February 18, 2009, at the Marriott Residence Inn, National Harbor, Maryland.

  2. 37. DINING ROOM FROM BALCONY. THE DINING ROOM ROOF IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. DINING ROOM FROM BALCONY. THE DINING ROOM ROOF IS SUPPORTED BY A SCISSOR TRUSS SYSTEM REINFORCED WITH TURNBUCKLE IRON RODS AND GUSSET PLATES (NOTE: THIS SYSTEM DIFFERS FROM THE LOBBY). - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  3. Highly Accurate Antibody Assays for Early and Rapid Detection of Tuberculosis in African and Asian Elephants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tuberculosis (TB) in elephants is a re-emerging zoonotic disease caused primarily by Mycobacterium tuberculosis. Current methods for screening and diagnosis rely on trunk wash culture, which has serious limitations due to low test sensitivity, slow turn-around time, and variable sample quality. Inn...

  4. Guiding Users to Unmediated Interlibrary Loan

    ERIC Educational Resources Information Center

    Adams, Carolyn; Ressel, Margret J.; Silva, Erin S.

    2009-01-01

    This article provides a practitioner's guide to marketing user-initiated borrowing at the point of need. By reviewing interlibrary loan book requests and manually transferring them to an INN-Reach consortial system, Link+, the University of Nevada, Reno Libraries were able to successfully market the service, deliver materials faster, and save…

  5. Canadian Association for the Study of Adult Education. Proceedings of the Annual Conference (11th, Saskatoon, Saskatchewan, Canada, May 1992).

    ERIC Educational Resources Information Center

    Taylor, Maurice, Ed.; Bedard, Rene, Ed.

    Among 8 French and 54 English papers in this report are the following: "Marks on Paper" (Andruske); "A Multifaceted Approach to Program Evaluation" (Barabash-Pope et al.); "Marine Incidents and their Prevention through Education" (Boshier); "Exploring Needs of Adult Students in Postsecondary Institutions" (Bradley, Cleveland-Innes); "Emancipation…

  6. The River Talks: An Ecocritical "Korero" about Ecological Performance, Community Activism and "Slow Violence"

    ERIC Educational Resources Information Center

    Matthewman, Sasha; Mullen, Molly; Patuwai, Tamati

    2015-01-01

    On 27 February 2013, Mad Ave staged "The River Talks," a collation of linked performances in and on the banks of the Omaru River in Glen Innes, Auckland, New Zealand. The event brought together artistic and discursive works that challenged a view of this local river as always and forever degraded. An example of committed ecological…

  7. Interpreting Letters and Reading Script: Evidence for Female Education and Literacy in Tudor England

    ERIC Educational Resources Information Center

    Daybell, James

    2005-01-01

    Attempts to write the history of female education are hampered by the relative informality of teaching provision for women in early modern England. Since most women were excluded from male centres of learning--the grammar schools, universities and Inns of Court--historians are deprived of institutional records, which so well elucidate the…

  8. 12. Oblique view northeast of south elevation at southwest corner ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Oblique view northeast of south elevation at southwest corner of building. Door at center accesses storage area. Pedimented 'niche' at left center holds mosaic shown in HABS-CA-2611-B-14. Scale visible at left edge of open door. - Deetjen's Big Sur Inn, Hayloft Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  9. Back to the Future: The Brownstone and FutureLink After-School Programs for Homeless Children.

    ERIC Educational Resources Information Center

    Homes for the Homeless, Inc., New York, NY.

    Homes for the Homeless initiated a family and community approach to learning at its American Family Inns (homeless shelters) via a customized, shelter-based, accelerated after-school program, Brownstone/FutureLink. The program helps improve students' grades, self-confidence, and academic potential. It requires parents, shelter staff, and public…

  10. 75 FR 28592 - Notice of Public Scoping Meetings for the Missouri River Authorized Purposes Study, Missouri...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... Rd., Billings, MT 59101. 29. Thursday, Aug. 19: Thermopolis, Wyoming, Days Inn Thermopolis Hot..., 225 North Roberts, Helena, MT 59620-1201. 10. Wednesday, August 18: Billings, Montana State University Billings, 1500 University Drive, Billings, MT 57101. 11. Thursday, August 19: Central Wyoming College,...

  11. 77 FR 13338 - Tribal Consultation Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-06

    ... Avenue Phoenix, AZ 85021; Tuesday, April 3, 2012--Billings, Montana--Holiday Inn Grand Montana 5500 Midland Road, Billings, MT 59101. FOR FURTHER INFORMATION CONTACT: Camille Loya, Acting Regional Program..., Arizona, and Billings, Montana, are being held in conjunction with the HHS 2012 Regional...

  12. 76 FR 41808 - Regional Tribal Consultations on Implementation of Indian Land Consolidation Program Under Cobell...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ........ Holiday Inn Grand Montana Hotel & Convention Center 5500 Midland Road Billings, MT 59101, (406) 248-7701... Settlement. The initial regional consultation meeting in Billings, Montana, was announced by a previous... consultation meeting will take place on Friday, July 15, 2011, in Billings, Montana. Additional...

  13. 76 FR 46217 - Implementation of the Amendments to the International Convention on Standards of Training...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ..., 1201 NW Le Jeune Road, Building A, Miami, FL 33126. Wednesday, August 24, 2011, Hilton Garden Inn Hotel..., Seattle, WA 98121. Wednesday, September 7, 2011 at United States Coast Guard Headquarters Building, Room... photo identification (for example, a driver's license) will be required for entrance to the...

  14. 2012 BATTERIES GORDON RESEARCH CONFERENCE, MARCH 4-9, 2012

    SciTech Connect

    Stephen Harris

    2012-03-09

    The Gordon Research Conference on BATTERIES was held at Four Points Sheraton / Holiday Inn Express, Ventura, California, March 4-9, 2012. The Conference was well-attended with 176 participants. Gordon Research Conferences does not permit publication of meeting proceedings.

  15. 76 FR 11762 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... each business listed under the shark dealer permit which first receives Atlantic sharks (71 FR 58057... permit (71 FR 58057; October 2, 2006). These certificate(s) are valid for 3 years. As such, vessel owners... Orange, FL 32127. 3. May 5, 2011, 12 p.m.-4 p.m., Comfort Inn, 4 Fisher Street, Foxborough, MA 02035....

  16. 75 FR 2467 - Hours of Service

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-15

    ... Act Statement for the FDMS published in the Federal Register on January 17, 2008 (73 FR 3316), or you... (75 FR 285). FMCSA announces a fourth public listening session to solicit written and/or oral comments...: The January 28 meeting will be held in Davenport, Iowa, at the Comfort Inn Hotel and Suites,...

  17. The Great Libraries of Dublin: A Scholar's Delight.

    ERIC Educational Resources Information Center

    Chepesiuk, Ronald

    1983-01-01

    Provides descriptions of prominent libraries in Dublin, Ireland, including Trinity College Library, National Library of Ireland, Chester Beatty Library, Marsh's Library (first public library), Kings Inn Law School Library, Steevens Hospital Library, Royal Irish Academy Library, Royal Dublin Society Library, religious libraries (Franciscan,,…

  18. Fulfilling Dreams: Transitions into an ECE Online Preservice Teacher Education Degree

    ERIC Educational Resources Information Center

    Taylor, Pauline

    2009-01-01

    There is increased attention on the first year experience at universities generally as a result of the Australian federal government's focus on increased accountability for universities and widening participation in further education (DEST, 2003; Jardine & Krause, 2005; Kift, 2005; Krause, Hartley, James & McInnes, 2005). However, these studies do…

  19. Gay Aging

    ERIC Educational Resources Information Center

    Haber, David

    2009-01-01

    The oldest of the baby boomers (boomers) were age 63 in 2009 and on the verge of retirement. This cohort has had a history of making societal changes throughout its life cycle, and it is unlikely that retirement, as we know it, will remain unscathed. This article highlights two events--the Stonewall Inn riots and two prominent professional…

  20. 75 FR 33629 - Developing Guidance on Naming, Labeling, and Packaging Practices to Reduce Medication Errors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND... day. ADDRESSES: The public workshop will be held at the Holiday Inn College Park, 10000 Baltimore Ave., College Park, MD 20740. FOR FURTHER INFORMATION CONTACT: Colleen O'Malley, Center for Drug Evaluation...

  1. Columbine Author Speaks at Conference

    ERIC Educational Resources Information Center

    Cook, Andrea J.

    2004-01-01

    Brooks Brown, the author of No Easy Answers: The Truth Behind Death at Columbine High School, spoke at the 11th annual Reclaiming Youth International No Disposable Kids conference at Rushmore Plaza Holiday Inn. Brown, who worked with Michael Moore on his Academy Award winning documentary, "Bowling for Columbine," said the letters he received from…

  2. 76 FR 40717 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    .... Hughesville Volunteer Fire Company, Social Hall, 10 South Railroad Street, Hughesville, PA 07456. Tuesday...), Bartonsville, PA 18321. Wednesday, July 20, 2011, 6 p.m. Holiday Inn Select, Regina Room, 111 EDT. West Main... gas to be moved through the system. ] Palmerton Loop--Installation of 3.2 miles of...

  3. 76 FR 52596 - Proposed Establishment of Class C Airspace for Long Beach, CA; Public Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Federal Aviation Administration 14 CFR Part 71 Proposed Establishment of Class C Airspace for Long Beach... airspace users and others, concerning a proposal to establish Class C airspace at Long Beach, CA. The... on or before December 12, 2011. ADDRESSES: The meetings will be held at the Holiday Inn Long...

  4. 1. Historic American Buildings Survey, August, 1971 SOUTH (FRONT) ELEVATIONS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey, August, 1971 SOUTH (FRONT) ELEVATIONS OF CORNER OF UNITED STATES HOTEL (FAR LEFT), JUDGE AND NUNAN'S SADDLERY, P.J. RYAN'S FIRST BRICK STORE BUILDING (JACKSONVILLE INN). - P. J. Ryan's First Brick Store Building, 175 East California Street, Jacksonville, Jackson County, OR

  5. NIH Clinical Center: There’s No Other Hospital Like It | NIH MedlinePlus the Magazine

    MedlinePlus

    ... research to test a new drug, device, or intervention. There are many programs in place to ease the clinical research process for both patients and their families. Pediatric patients and their families stay at The Children’s Inn, a 24-hours-a-day, seven-days- ...

  6. Connect the Book. The Midnight Ride of Paul Revere

    ERIC Educational Resources Information Center

    Brodie, Carolyn S.

    2005-01-01

    The famous poem "The Midnight Ride of Paul Revere" by Henry Wadsworth Longfellow (originally included in "Tales of a Wayside Inn" as "The Landlord's Tale") has been illustrated by a number of children's book artists over the years. One particular version of note was graved and painted by Christopher Bing and published by Handprint Books in 2001.…

  7. 1. Historic American Buildings Survey, August, 1979 SOUTH (FRONT) ELEVATIONS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey, August, 1979 SOUTH (FRONT) ELEVATIONS OF CORNER OF UNITED STATES HOTEL (FAR LEFT), JUDGE AND NUNAN'S SADDLERY, P.J. RYAN'S FIRST BRICK STORE BUILDING (JACKSONVILLE INN). - Judge & Nunan's Saddlery, 165 East California Street, Jacksonville, Jackson County, OR

  8. 76 FR 18540 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... Environmental Management Site-Specific Advisory Board, Northern New Mexico AGENCY: Department of Energy. ACTION...-Specific Advisory Board (EM SSAB), Northern New Mexico (known locally as the Northern New Mexico Citizens....m.-4 p.m. ADDRESSES: Holiday Inn Express and Suites, 60 Entrada Drive, Los Alamos, New Mexico...

  9. Technology in the Classroom.

    ERIC Educational Resources Information Center

    Speidel, Gisela E., Ed.

    1995-01-01

    This theme issue contains 20 articles dealing with technology in the classroom. The articles are: (1) "Distance Learning and the Future of Kamehameha Schools Bishop Estate" (Henry E. Meyer); (2) "Technology and Multiple Intelligences" (Bette Savini); (3) "Technology Brings Voyagers into Classrooms" (Kristina Inn and others); (4) "Technologies Old…

  10. 13. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 STAIR DETAIL, SECOND FLOOR LEVEL (INSPECTION OF STAIR REVEALS PRESENCE OF A STRING OPPOSITE BANNISTER ORIGINALLY). - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  11. 12. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 CLOSE-UP DETAIL OF CORNER FIREPLACE. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  12. 11. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 SOUTHWEST ROOM SHOWING ORIGINAL CORNER FIREPLACE, OPENING BEHIND BAR. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  13. 9. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 CLOSE-UP OF SMALL FRONT FIREPLACE, SOUTHWEST ROOM. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  14. 8. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 REEDING DETAIL OF MANTEL IN NORTHEAST PARLOR. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  15. 6. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 NORTHWEST ROOM SHOWING COOK FIREPLACE, ORIGINAL MANTEL, CRANE AND OPENING FOR BAKE OVEN. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  16. 5. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 INTERIOR DETAIL, NORTHEAST AND SOUTHEAST PARLORS, ORIGINAL MANTEL (LEFT - RADIATOR COVERED). - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  17. 7. Oblique view southeast of north end of building. Scale ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Oblique view southeast of north end of building. Scale visible adjacent to door at lower right. Compare to HABS-CA-2611-B-4. - Deetjen's Big Sur Inn, Hayloft Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  18. Novel compound semiconductor devices based on III-V nitrides

    SciTech Connect

    Pearton, S.J.; Abernathy, C.R.; Ren, F.

    1995-10-01

    New developments in dry and wet etching, ohmic contacts and epitaxial growth of Ill-V nitrides are reported. These make possible devices such as microdisk laser structures and GaAs/AlGaAs heterojunction bipolar transistors with improved InN ohmic contacts.

  19. 76 FR 8351 - Meeting of the Defense Department Advisory Committee on Women in the Services (DACOWITS)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... availability of space. DATES: March 4, 2011, from 8 a.m.-4 p.m. ADDRESSES: Residence Inn Marriott, 550 Army Navy Dr, Arlington, VA 22202. FOR FURTHER INFORMATION CONTACT: MSgt Robert Bowling, USAF, or DACOWITS, 4000 Defense Pentagon, Room 2C548A, Washington, DC 20301- 4000, E-mail:...

  20. 76 FR 24463 - Caribbean Fishery Management Council; Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA406 Caribbean Fishery Management Council; Public... held on May 24-25, 2011. ADDRESSES: The meeting will be held at the Hampton Inn Hotel, 6530 Isla...

  1. 78 FR 43860 - Caribbean Fishery Management Council; Scoping Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... plans (Spiny Lobster, Reef Fish, Coral and Queen Conch). The goal is to create management plans tailored... federal waters. Dates and Addresses: Due to the tropical storm Chantel the scoping meetings in these..., Mayag ez 00680, Puerto Rico. August 6, 2013--7 p.m.-10 p.m.--at the Holiday Inn Ponce & Tropical...

  2. 25. LOBBY FIREPLACE. NOTE THE GEYSER DECORATING THE FIREPLACE SCREEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. LOBBY FIREPLACE. NOTE THE GEYSER DECORATING THE FIREPLACE SCREEN AND THE WEIGHTS AND PENDULUM HANGING FROM THE CLOCK DESIGNED BY ARCHITECT ROBERT C. REAMER. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  3. Final Report

    SciTech Connect

    Ananda M. Chakrabarty

    2009-06-18

    This is the front matter for the 7th Biennial Symposium, International Society for Environmental Biotechnology, held at the Holiday Inn Chicago Mart Plaza, Chicago, Illinois on the dates of June 18-21, 2004. It contains a list of the symposium organizers, acknowledgements and the symposium overview.

  4. Another Look at the Wine Butler

    ERIC Educational Resources Information Center

    DeWeerd, Alan J.

    2007-01-01

    In a recent article, Iain MacInnes analyzed the static equilibrium of a system consisting of a wine bottle and a wine butler. After discussing that composite system, students can be asked to consider only the bottle (and its contents) as the system. An interesting challenge for them is to describe the forces on the bottle in static equilibrium.

  5. The Fashion Police: Never out of Fashion

    ERIC Educational Resources Information Center

    Barlow, Dudley

    2004-01-01

    Some readers will recall Newhart, Bob Newhart's television series from 1982 to 1990. In it, he played Dick Ludon, a New Yorker who moved to Vermont with his wife to run an inn. Stephanie Vanderkellen, a snotty, rich, young woman, worked there as a maid to appease her parents. Her boyfriend, Michael, was not rich but was as snobbish as she was.…

  6. 5. View to east of west elevation. Second story deck ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View to east of west elevation. Second story deck at right opens off 'Fireside' guest room; Helmuth Deetjen hand-carved the balusters. Scale just visible against first story wall at lower right. - Deetjen's Big Sur Inn, Hayloft Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  7. The New Poverty: Homeless Families in America.

    ERIC Educational Resources Information Center

    Nunez, Ralph da Costa

    This book discusses homeless families in the United States and advocates the efforts of residential educational and employment training centers--American Family Inns--which provide comprehensive services education, job training, and parenting and life skills to address the poverty-related conditions that contribute to homelessness. Chapters of the…

  8. View northeast of southwest end at south corner of building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northeast of southwest end at south corner of building. Castro Creek Canyon drops off sharply at right of picture, precluding photography of southeast side of building (see HABS-CA-2611-4 for reference.) - Deetjen's Big Sur Inn, Antique Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  9. 7. View southwest of 'Chalet' room from doorway. Windows beyond ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View southwest of 'Chalet' room from doorway. Windows beyond bed are in southwest end of building, while those at left overlook Castro Creek Canyon. Scale visible against door frame near head of bed. - Deetjen's Big Sur Inn, Champagne Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  10. 27. LOBBY, LOOKING NORTHEAST FROM SECOND FLOOR. THE STRUCTURE IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. LOBBY, LOOKING NORTHEAST FROM SECOND FLOOR. THE STRUCTURE IN UPPER LEFT HAND SIDE OF PHOTOGRAPH, A MUSICIANS' PLATFORM CALLED 'THE CROW'S NEST' WAS BUILT IN THE GABLE. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  11. "Building the Natural Society of the Future": The Peckham Experiment (1943) as an Anarchist Account of Childhood and Education

    ERIC Educational Resources Information Center

    Charkin, Emily

    2014-01-01

    "The Peckham Experiment" (Innes H. Pearse and Lucy H. Crocker, Edinburgh: Scottish Academic Press, 1985) is a book about the Peckham Health Centre (1935-1950), which was a scientific experiment and community centre set up to identify and foster conditions of good health for local working-class families in South London. The book was…

  12. 2009 Infrastructure Platform Review Report

    SciTech Connect

    Ferrell, John

    2009-12-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the U.S. Department of Energy Biomass program‘s Infrastructure platform review meeting, held on February 19, 2009, at the Marriott Residence Inn, National Harbor, Maryland.

  13. 78 FR 46578 - Caribbean Fishery Management Council; Scoping Meetings Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    .... SUPPLEMENTARY INFORMATION: The original notice published in the Federal Register on July 22, 2013 (78 FR 43860....-10 p.m.--Mayaguez Resort & Casino, Route 104, Km 0.3, Mayag ez 00680, Puerto Rico August 6, 2013--7 p.m.-10 p.m.--at the Holiday Inn Ponce & Tropical Casino, 3315 Ponce By Pass, Ponce, Puerto Rico....

  14. 77 FR 76011 - Defense Legal Policy Board; Notice of Federal Advisory Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... of the Secretary Defense Legal Policy Board; Notice of Federal Advisory Committee Meeting AGENCY... committee meeting of the Defense Legal Policy Board. ADDRESSES: Holiday Inn Ballston, 4610 N. Fairfax Drive, Arlington, Virginia 22203. DATES: A meeting of the Defense Legal Policy Board (hereafter referred to...

  15. Possibilities and Potential Barriers: Learning to Plan for Differentiated Instruction in Elementary Science

    ERIC Educational Resources Information Center

    Tobin, Ruthanne; Tippett, Christine D.

    2014-01-01

    Research indicates that differentiated practices enhance the likelihood of meeting the needs of students who find literacy learning challenging (Tobin & McInnes, 2008; Tomlinson, 2003). The aim of the professional development project described here was to leverage these findings and to build the foundation for future research exploring if…

  16. Diverse Pathways in Children's Learning.

    ERIC Educational Resources Information Center

    Lambert, Beverley

    1996-01-01

    Used a Partially Ordered Scaling of Items method to analyze block construction play in a replication of Innes and King-Shaw's 1985 study. Found several developmental pathways for block play, illustrating the web-like nature of conceptual development. Results suggest a contextual developmental approach to better acknowledge individual diversity in…

  17. 75 FR 81642 - Long-Term North to South Water Transfer Program, Sacramento County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ..., Bureau of Reclamation (Reclamation) and the San Luis & Delta-Mendota Water Authority propose to prepare a... water agencies south of the Sacramento-San Joaquin Delta (Delta) and in the San Francisco Bay Area. The.... Sacramento at the Best Western Expo Inn & Suites, 1413 Howe Avenue. Los Banos at the San Luis &...

  18. Calling All Golfers | Poster

    Cancer.gov

    Teams are forming for the third annual R&W Club Frederick Golf Tournament on Sept. 14. Last year’s tournament hosted more than 40 players and raised nearly $1,000 for the NIH Children’s Inn, Bethesda, Md.  The tournament will be held at Maryland National Golf Club in Middletown, Md. 

  19. 78 FR 16260 - Environmental Management Site-Specific Advisory Board, Savannah River Site

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-14

    ...-Specific Advisory Board, Savannah River Site (78 FR 14088). This document makes a correction to that notice... Federal Register of March 4, 2013, in FR Doc. 2013-04875, on page 14088, please make the following... address is Hilton Garden Inn, 1065 Stevens Creek Road, Augusta, GA 30907. The reason for this change...

  20. Optical, structural, and transport properties of indium nitride, indium gallium nitride alloys grown by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Khan, Neelam

    InGaN based, blue and green light emitting diodes (LEDs) have been successfully produced over the past decade. But the progress of these LEDs is often limited by the fundamental problems of InGaN such as differences in lattice constants, thermal expansion coefficients and physical properties between InN and GaN. This difficulty could be addressed by studying pure InN and InxGa 1-xN alloys. In this context Ga-rich InxGa1-xN (x ≤ 0.4) epilayers were grown by metal organic chemical vapor deposition (MOCVD). X-ray diffraction (XRD) measurements showed InxGa1-xN films with x= 0.37 had single phase. Phase separation occurred for x ˜ 0.4. To understand the issue of phase separation in Ga-rich InxGa 1-xN, studies on growth of pure InN and In-rich InxGa 1-xN alloys were carried out. InN and In-rich InxGa1-xN (x ˜ 0.97-0.40) epilayers were grown on AlN/Al2O3 templates. A Hall mobility of 1400 cm2/Vs with a carrier concentration of 7x1018cm -3 was observed for InN epilayers grown on AlN templates. Photoluminescence (PL) emission spectra revealed a band to band emission peak at ˜0.75 eV for InN. This peak shifted to 1.15 eV when In content was varied from 1.0 to 0.63 in In-rich InxGa1-xN epilayers. After growth parameter optimization of In-rich InxGa1-xN alloys with (x = 0.97-0.40) were successfully grown without phase separation. Effects of Mg doping on the PL properties of InN epilayers grown on GaN/Al 2O3 templates were investigated. An emission line at ˜ 0.76 eV, which was absent in undoped InN epilayers and was about 60 meV below the band edge emission peak at ˜ 0.82 eV, was observed to be the dominant emission in Mg-doped InN epilayers. PL peak position and the temperature dependent emission intensity corroborated each other and suggested that Mg acceptor level in InN is about 60 meV above the valance band maximum. Strain effects on the emission properties of InGaN/GaN multiple quantum wells (MQWs) were studied using a single blue LED wafer possessing a continuous

  1. Development of a Computational Chemical Vapor Deposition Model: Applications to Indium Nitride and Dicyanovinylaniline

    NASA Technical Reports Server (NTRS)

    Cardelino, Carlos

    1999-01-01

    A computational chemical vapor deposition (CVD) model is presented, that couples chemical reaction mechanisms with fluid dynamic simulations for vapor deposition experiments. The chemical properties of the systems under investigation are evaluated using quantum, molecular and statistical mechanics models. The fluid dynamic computations are performed using the CFD-ACE program, which can simulate multispecies transport, heat and mass transfer, gas phase chemistry, chemistry of adsorbed species, pulsed reactant flow and variable gravity conditions. Two experimental setups are being studied, in order to fabricate films of: (a) indium nitride (InN) from the gas or surface phase reaction of trimethylindium and ammonia; and (b) 4-(1,1)dicyanovinyl-dimethylaminoaniline (DCVA) by vapor deposition. Modeling of these setups requires knowledge of three groups of properties: thermodynamic properties (heat capacity), transport properties (diffusion, viscosity, and thermal conductivity), and kinetic properties (rate constants for all possible elementary chemical reactions). These properties are evaluated using computational methods whenever experimental data is not available for the species or for the elementary reactions. The chemical vapor deposition model is applied to InN and DCVA. Several possible InN mechanisms are proposed and analyzed. The CVD model simulations of InN show that the deposition rate of InN is more efficient when pulsing chemistry is used under conditions of high pressure and microgravity. An analysis of the chemical properties of DCVA show that DCVA dimers may form under certain conditions of physical vapor transport. CVD simulations of the DCVA system suggest that deposition of the DCVA dimer may play a small role in the film and crystal growth processes.

  2. Biosecurity and Vector Behaviour: Evaluating the Potential Threat Posed by Anglers and Canoeists as Pathways for the Spread of Invasive Non-Native Species and Pathogens

    PubMed Central

    Anderson, Lucy G.; White, Piran C. L.; Stebbing, Paul D.; Stentiford, Grant D.; Dunn, Alison M.

    2014-01-01

    Invasive non-native species (INNS) endanger native biodiversity and are a major economic problem. The management of pathways to prevent their introduction and establishment is a key target in the Convention on Biological Diversity's Aichi biodiversity targets for 2020. Freshwater environments are particularly susceptible to invasions as they are exposed to multiple introduction pathways, including non-native fish stocking and the release of boat ballast water. Since many freshwater INNS and aquatic pathogens can survive for several days in damp environments, there is potential for transport between water catchments on the equipment used by recreational anglers and canoeists. To quantify this biosecurity risk, we conducted an online questionnaire with 960 anglers and 599 canoeists to investigate their locations of activity, equipment used, and how frequently equipment was cleaned and/or dried after use. Anglers were also asked about their use and disposal of live bait. Our results indicate that 64% of anglers and 78.5% of canoeists use their equipment/boat in more than one catchment within a fortnight, the survival time of many of the INNS and pathogens considered in this study and that 12% of anglers and 50% of canoeists do so without either cleaning or drying their kit between uses. Furthermore, 8% of anglers and 28% of canoeists had used their equipment overseas without cleaning or drying it after each use which could facilitate both the introduction and secondary spread of INNS in the UK. Our results provide a baseline against which to evaluate the effectiveness of future biosecurity awareness campaigns, and identify groups to target with biosecurity awareness information. Our results also indicate that the biosecurity practices of these groups must improve to reduce the likelihood of inadvertently spreading INNS and pathogens through these activities. PMID:24717714

  3. Raman scattering and cathodoluminescence characterization of near lattice-matched InxAl1-xN epilayers

    NASA Astrophysics Data System (ADS)

    Cuscó, R.; Pastor, D.; Hernández, S.; Artús, L.; Martínez, O.; Jiménez, J.; Martin, R. W.; O'Donnell, K. P.; Watson, I. M.

    2008-10-01

    We present a Raman scattering and cathodoluminescence study of a set of InxAl1-xN/GaN epilayers with InN fractions around the lattice-matched composition. We observed the A1(LO) and InN-like E2 modes of the alloy, whose frequencies are in good agreement with theoretical predictions, but we were unable to detect the AlN-like E2 mode. The InN-like E2 mode did not exhibit noticeable frequency shifts in the studied samples. This is explained by the presence of residual strain in the pseudomorphic InxAl1-xN films. A luminescence peak that shifts to lower energies with an increasing InN fraction was observed at energies above the band edge of the GaN substrate. The cathodoluminescence peak energy is lower than expected, indicating a large band-gap bowing in these alloy layers.

  4. Auger recombination as the dominant recombination process in indium nitride at low temperatures during steady-state photoluminescence

    SciTech Connect

    Seetoh, I. P.; Soh, C. B.; Fitzgerald, E. A.; Chua, S. J.

    2013-03-11

    Auger recombination in InN films grown by metal-organic chemical vapor deposition was studied by steady-state photoluminescence at different laser excitation powers and sample temperatures. It was dominant over radiative recombination and Shockley-Read-Hall recombination at low temperatures, contributing to the sub-linear relationship between the integrated photoluminescence intensity and laser excitation power. Auger recombination rates increased gradually with temperature with an activation energy of 10-17 meV, in good agreement with values from transient photoluminescence reported in literature. As the Auger recombination rates were independent of material quality, they may form an upper limit to the luminous efficiency of InN.

  5. Decoupling single nanowire mobilities limited by surface scattering and bulk impurity scattering

    SciTech Connect

    Khanal, D. R.; Levander, A. X.; Wu, J.; Yu, K. M.; Liliental-Weber, Z.; Walukiewicz, W.; Grandal, J.; Sanchez-Garcia, M. A.; Calleja, E.

    2011-08-01

    We demonstrate the isolation of two free carrier scattering mechanisms as a function of radial band bending in InN nanowires via universal mobility analysis, where effective carrier mobility is measured as a function of effective electric field in a nanowire field-effect transistor. Our results show that Coulomb scattering limits effective mobility at most effective fields, while surface roughness scattering only limits mobility under very high internal electric fields. High-energy {alpha} particle irradiation is used to vary the ionized donor concentration, and the observed decrease in mobility and increase in donor concentration are compared to Hall effect results of high-quality InN thin films. Our results show that for nanowires with relatively high doping and large diameters, controlling Coulomb scattering from ionized dopants should be given precedence over surface engineering when seeking to maximize nanowire mobility.

  6. Shared-savings cuts hotel's losses from EMS removal

    SciTech Connect

    Galvin, C.

    1982-11-08

    A shared-savings contract will minimize the Myrtle Beach, SC Downtown Holiday Inn's losses of replacing a poorly performing Energy Master energy-management system with Scientific Atlanta equipment. The contract with Energy Master Inc. (EMI), which saved Holiday Inn the $80,000 to $90,000 purchase price, also permitted removal (a year after installation) of the equipment when it failed to generate energy savings. A dispute between Associated Energy Consultants (AEC), which was to receive half the savings in exchange for arranging the equipment financing, is described. At $51,745, the 262-point Scientific Atlanta system should have a 1.7-year payback. The hotel's electric bills were $2000 a month lower during the first three months of operation. (DCK)

  7. III-Nitride nanowire optoelectronics

    NASA Astrophysics Data System (ADS)

    Zhao, Songrui; Nguyen, Hieu P. T.; Kibria, Md. G.; Mi, Zetian

    2015-11-01

    Group-III nitride nanowire structures, including GaN, InN, AlN and their alloys, have been intensively studied in the past decade. Unique to this material system is that its energy bandgap can be tuned from the deep ultraviolet (~6.2 eV for AlN) to the near infrared (~0.65 eV for InN). In this article, we provide an overview on the recent progress made in III-nitride nanowire optoelectronic devices, including light emitting diodes, lasers, photodetectors, single photon sources, intraband devices, solar cells, and artificial photosynthesis. The present challenges and future prospects of III-nitride nanowire optoelectronic devices are also discussed.

  8. Stranski-Krastanov InN/InGaN quantum dots grown directly on Si(111)

    SciTech Connect

    Soto Rodriguez, Paul E. D. Aseev, Pavel; Gómez, Victor J.; Kumar, Praveen; Ul Hassan Alvi, Naveed; Calleja, Enrique; Morales, Francisco M.; Senichev, Alexander; Lienau, Christoph; Nötzel, Richard

    2015-01-12

    The authors discuss and demonstrate the growth of InN surface quantum dots on a high-In-content In{sub 0.73}Ga{sub 0.27}N layer, directly on a Si(111) substrate by plasma-assisted molecular beam epitaxy. Atomic force microscopy and transmission electron microscopy reveal uniformly distributed quantum dots with diameters of 10–40 nm, heights of 2–4 nm, and a relatively low density of ∼7 × 10{sup 9} cm{sup −2}. A thin InN wetting layer below the quantum dots proves the Stranski-Krastanov growth mode. Near-field scanning optical microscopy shows distinct and spatially well localized near-infrared emission from single surface quantum dots. This holds promise for future telecommunication and sensing devices.

  9. Cl{sub 2}-based dry etching of the AlGaInN system in inductively coupled plasmas

    SciTech Connect

    Cho, Hyun; Vartuli, C.B.; Abernathy, C.R.; Donovan, S.M.; Pearton, S.J.; Shul, R.J.; Han, J.

    1997-12-01

    Cl{sub 2}-based Inductively Coupled Plasmas with low additional dc self- biases(-100V) produce convenient etch rates(500-1500 A /min) for GaN, AlN, InN, InAlN and InGaN. A systematic study of the effects of additive gas(Ar, N{sub 2}, H{sub 2}), discharge composition and ICP source power and chuck power on etch rate and surface morphology has been performed. The general trends are to go through a maximum in etch rate with percent Cl{sub 2} in the discharge for all three mixtures, and to have an increase(decrease) in etch rate with source power(pressure). Since the etching is strongly ion-assisted, anisotropic pattern transfer is readily achieved. Maximum etch selectivities of approximately 6 for InN over the other nitrides were obtained.

  10. The Discovery of the Nearest Star

    NASA Astrophysics Data System (ADS)

    Glass, I. S.

    2007-12-01

    In the 1830s, the double star α Centauri was the subject of the first successful stellar parallax measurement. For almost eighty years it remained the nearest star known. However, in 1915 at the Union Observatory in Johannesburg, R.T.A. Innes found a faint object near α Cen with a similar proper motion. Its parallax was measured over the following two years by J.G.E.G. Voûte at the Cape and by Innes himself. The latter, on the basis of inadequate data, declared it to be closer than α and named it 'Proxima Centaurus'. The first statistically significant data that implied it truly is the nearest star were published in 1928 by H.L. Alden, based on observations at the Yale Southern Station in Johannesburg. Discordant results continued however to appear until 1966. The measurements made by the Hipparcos astrometric satellite appear to have established its proximity beyond question.

  11. Solar hot water system installed at Anderson, South Carolina

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A description is given of the solar energy hot water system installed in the Days Inns of America, Inc., at Anderson, South Carolina. The building is a low-rise, two-story 114-room motel. The solar system was designed to provide 40 percent of the total hot water demand. The collector is a flat plate, liquid with an area of 750 square feet. Operation of this system was begun in November 1977, and has performed flawlessly for one year.

  12. Growth of gallium nitride and indium nitride nanowires on conductive and flexible carbon cloth substrates

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Ling, Yichuan; Wang, Gongming; Lu, Xihong; Tong, Yexiang; Li, Yat

    2013-02-01

    We report a general strategy for synthesis of gallium nitride (GaN) and indium nitride (InN) nanowires on conductive and flexible carbon cloth substrates. GaN and InN nanowires were prepared via a nanocluster-mediated growth method using a home built chemical vapor deposition (CVD) system with Ga and In metals as group III precursors and ammonia as a group V precursor. Electron microscopy studies reveal that the group III-nitride nanowires are single crystalline wurtzite structures. The morphology, density and growth mechanism of these nanowires are determined by the growth temperature. Importantly, a photoelectrode fabricated by contacting the GaN nanowires through a carbon cloth substrate shows pronounced photoactivity for photoelectrochemical water oxidation. The ability to synthesize group III-nitride nanowires on conductive and flexible substrates should open up new opportunities for nanoscale photonic, electronic and electrochemical devices.We report a general strategy for synthesis of gallium nitride (GaN) and indium nitride (InN) nanowires on conductive and flexible carbon cloth substrates. GaN and InN nanowires were prepared via a nanocluster-mediated growth method using a home built chemical vapor deposition (CVD) system with Ga and In metals as group III precursors and ammonia as a group V precursor. Electron microscopy studies reveal that the group III-nitride nanowires are single crystalline wurtzite structures. The morphology, density and growth mechanism of these nanowires are determined by the growth temperature. Importantly, a photoelectrode fabricated by contacting the GaN nanowires through a carbon cloth substrate shows pronounced photoactivity for photoelectrochemical water oxidation. The ability to synthesize group III-nitride nanowires on conductive and flexible substrates should open up new opportunities for nanoscale photonic, electronic and electrochemical devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr

  13. International Workshop on Vibration Isolation Technology for Microgravity Science Applications

    NASA Technical Reports Server (NTRS)

    Lubomski, Joseph F. (Editor)

    1992-01-01

    The International Workshop on Vibration Isolation Technology for Microgravity Science Applications was held on April 23-25, 1991 at the Holiday Inn in Middleburg Heights, Ohio. The main objective of the conference was to explore vibration isolation requirements of space experiments and what level of vibration isolation could be provided both by present and planned systems on the Space Shuttle and Space Station Freedom and by state of the art vibration isolation technology.

  14. 4. Contextual oblique view southeast showing building in landscaped and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Contextual oblique view southeast showing building in landscaped and natural setting. Scale visible adjacent to storage area door at lower right center. Stairs to second floor guest rooms out of sight at center, next to small sign. Open door at lower left center is small, one-story storage building on north side of 'Hayloft' stairs. - Deetjen's Big Sur Inn, Hayloft Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  15. A Novel Quantitative Approach to Concept Analysis: The Internomological Network

    PubMed Central

    Cook, Paul F.; Larsen, Kai R.; Sakraida, Teresa J.; Pedro, Leli

    2012-01-01

    Background When a construct such as patients’ transition to self-management of chronic illness is studied by researchers across multiple disciplines, the meaning of key terms can become confused. This results from inherent problems in language where a term can have multiple meanings (polysemy) and different words can mean the same thing (synonymy). Objectives To test a novel quantitative method for clarifying the meaning of constructs by examining the similarity of published contexts in which they are used. Method Published terms related to the concept transition to self-management of chronic illness were analyzed using the internomological network (INN), a type of latent semantic analysis to calculate the mathematical relationships between constructs based on the contexts in which researchers use each term. This novel approach was tested by comparing results to those from concept analysis, a best-practice qualitative approach to clarifying meanings of terms. By comparing results of the two methods, the best synonyms of transition to self-management, as well as key antecedent, attribute, and consequence terms, were identified. Results Results from INN analysis were consistent with those from concept analysis. The potential synonyms self-management, transition, and adaptation had the greatest utility. Adaptation was the clearest overall synonym, but had lower cross-disciplinary use. The terms coping and readiness had more circumscribed meanings. The INN analysis confirmed key features of transition to self-management, and suggested related concepts not found by the previous review. Discussion The INN analysis is a promising novel methodology that allows researchers to quantify the semantic relationships between constructs. The method works across disciplinary boundaries, and may help to integrate the diverse literature on self-management of chronic illness. PMID:22592387

  16. Structure-based rational design of peptide hydroxamic acid inhibitors to target tumor necrosis factor-α converting enzyme as potential therapeutics for hepatitis.

    PubMed

    Wu, Dan; Gu, Qiuhong; Zhao, Ning; Xia, Fei; Li, Zhiwei

    2015-12-01

    The human tumor necrosis factor-α converting enzyme (TACE) has recently been raised as a new and promising therapeutic target of hepatitis and other inflammatory diseases. Here, we reported a successful application of the solved crystal structure of TACE complex with a peptide-like ligand INN for rational design of novel peptide hydroxamic acid inhibitors with high potency and selectivity to target and inhibit TACE. First, the intermolecular interactions between TACE catalytic domain and INN were characterized through an integrated bioinformatics approach, with which the key substructures of INN that dominate ligand binding were identified. Subsequently, the INN molecular structure was simplified to a chemical sketch of peptide hydroxamic acid compound, which can be regarded as a linear tripeptide capped by a N-terminal carboxybenzyl group (chemically protective group) and a C-terminal hydroxamate moiety (coordinated to the Zn(2+) at TACE active site). Based on the sketch, a virtual combinatorial library containing 180 peptide hydroxamic acids was generated, from which seven samples were identified as promising candidates by using a knowledge-based protein-peptide affinity predictor and were then tested in vitro with a standard TACE activity assay protocol. Consequently, three designed peptide hydroxamic acids, i.e. Cbz-Pro-Ile-Gln-hydroxamic acid, Cbz-Leu-Ile-Val-hydroxamic acid and Cbz-Phe-Val-Met-hydroxamic acid, exhibited moderate or high inhibitory activity against TACE, with inhibition constants Ki of 36 ± 5, 510 ± 46 and 320 ± 26 nM, respectively. We also examined the structural basis and non-bonded profile of TACE interaction with a designed peptide hydroxamic acid inhibitor, and found that the inhibitor ligand is tightly buried in the active pocket of TACE, forming a number of hydrogen bonds, hydrophobic forces and van der Waals contacts at the interaction interface, conferring both stability and specificity for TACE-inhibitor complex

  17. 33 CFR 110.72aa - Elizabeth River Spectator Vessel Anchorage Areas, between Norfolk and Portsmouth, Virginia.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... line drawn between Hospital Point at latitude Latitude 36°50′50.5″ North, longitude 76°18′09.0″ West, and the tip of the channelside pier at the Holiday Inn Marina at latitude 36°50′29.5″ North, longitude... the Elizabeth River, bounded by the shore and a line drawn between Hospital Point at latitude...

  18. 33 CFR 110.72aa - Elizabeth River Spectator Vessel Anchorage Areas, between Norfolk and Portsmouth, Virginia.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... line drawn between Hospital Point at latitude Latitude 36°50′50.5″ North, longitude 76°18′09.0″ West, and the tip of the channelside pier at the Holiday Inn Marina at latitude 36°50′29.5″ North, longitude... the Elizabeth River, bounded by the shore and a line drawn between Hospital Point at latitude...

  19. 33 CFR 110.72aa - Elizabeth River Spectator Vessel Anchorage Areas, between Norfolk and Portsmouth, Virginia.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... line drawn between Hospital Point at latitude Latitude 36°50′50.5″ North, longitude 76°18′09.0″ West, and the tip of the channelside pier at the Holiday Inn Marina at latitude 36°50′29.5″ North, longitude... the Elizabeth River, bounded by the shore and a line drawn between Hospital Point at latitude...

  20. Powder-XRD and (14) N magic angle-spinning solid-state NMR spectroscopy of some metal nitrides.

    PubMed

    Kempgens, Pierre; Britton, Jonathan

    2016-05-01

    Some metal nitrides (TiN, ZrN, InN, GaN, Ca3 N2 , Mg3 N2 , and Ge3 N4 ) have been studied by powder X-ray diffraction (XRD) and (14) N magic angle-spinning (MAS) solid-state NMR spectroscopy. For Ca3 N2 , Mg3 N2 , and Ge3 N4 , no (14) N NMR signal was observed. Low speed (νr  = 2 kHz for TiN, ZrN, and GaN; νr  = 1 kHz for InN) and 'high speed' (νr  = 15 kHz for TiN; νr  = 5 kHz for ZrN; νr  = 10 kHz for InN and GaN) MAS NMR experiments were performed. For TiN, ZrN, InN, and GaN, powder-XRD was used to identify the phases present in each sample. The number of peaks observed for each sample in their (14) N MAS solid-state NMR spectrum matches perfectly well with the number of nitrogen-containing phases identified by powder-XRD. The (14) N MAS solid-state NMR spectra are symmetric and dominated by the quadrupolar interaction. The envelopes of the spinning sidebands manifold are Lorentzian, and it is concluded that there is a distribution of the quadrupolar coupling constants Qcc 's arising from structural defects in the compounds studied.

  1. RocKeTeria restaurant

    NASA Technical Reports Server (NTRS)

    2000-01-01

    When StenniSphere at John C. Stennis Space Center in Hancock County, Miss., opened in May 2000, it introduced the RocKeTeria, a new 1960s-style, space-themed restaurant located in the newly expanded visitor center. The restaurant, operated by the owners of Mary's Drive Inn of Biloxi, features an extensive collection of space-related photos from that era, as well as a full menu of home-style cooking.

  2. 4. View to northwest from within Castro Creek Canyon, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View to northwest from within Castro Creek Canyon, looking up at 'Antique' Building (HABS-CA-2611-C) at left and center, 'Champagne' Building (HABS-CA-2611-D) at right behind redwood trees. View gives indication of steepness of canyon, siting of these two buildings at canyon's edge. - Deetjen's Big Sur Inn, East Side of State Highway 1, Big Sur, Monterey County, CA

  3. Solar heating and hot water system installed at Cherry Hill, New Jersey

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  4. An interview with Enrico Coen.

    PubMed

    Vicente, Catarina

    2016-07-15

    Enrico Coen CBE FRS is a Project Leader at the John Innes Centre in Norwich, UK, who uses a variety of approaches to study patterning and morphogenesis in plants. We met with Enrico at the Spring Meeting of the British Society for Developmental Biology, where he was awarded the Waddington Medal, to ask him more about his career and his passion for art and book-writing. PMID:27436037

  5. Solar-Heated Water at a Motel--Mobile, Alabama

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar-assisted hot-water system for a new 122-unit motor inn in Mobile, Alabama, generates more than half the energy needed for hot-water heating at motel each year. System consists of 93 flat-plate collectors, 2,500 gallon (9,500 1) insulated storage tank located outdoors, heat exchangers and controls. Electronic thermometers, measuring the temperatures at 22 locations monitor system performance.

  6. The immiscibility of InAlN ternary alloy

    PubMed Central

    Zhao, Guijuan; Xu, Xiaoqing; Li, Huijie; Wei, Hongyuan; Han, Dongyue; Ji, Zesheng; Meng, Yulin; Wang, Lianshan; Yang, Shaoyan

    2016-01-01

    We have used two models based on the valence force field and the regular solution model to study the immiscibility of InAlN ternary alloy, and have got the spinodal and binodal curves of InAlN. Analyzing the spinodal decomposition curves, we obtain the appropriate concentration region for the epitaxial growth of the InN-AlN pseudobinary alloy. At a temperature most common for the epitaxial growth of InAlN (1000 K), the solubility of InN is about 10%. Then we introduce the mismatch strain item into the Gibbs free energy, and the effect of different substrates is taken into consideration. Considering Si, Al2O3, InN, GaN, AlN as a substrate respectively, it is found that all the five systems are stabilized with the upper critical solution temperature largely reduced. Finally, InN and GaN are potential substrates for In-rich InAlN, while AlN and GaN substrates are recommended in the Al-rich region. Si and Al2O3 may be ideal substrates for thin InAlN film. PMID:27221345

  7. Lattice-Polarity-Driven Epitaxy of Hexagonal Semiconductor Nanowires.

    PubMed

    Wang, Ping; Yuan, Ying; Zhao, Chao; Wang, Xinqiang; Zheng, Xiantong; Rong, Xin; Wang, Tao; Sheng, Bowen; Wang, Qingxiao; Zhang, Yongqiang; Bian, Lifeng; Yang, Xuelin; Xu, Fujun; Qin, Zhixin; Li, Xinzheng; Zhang, Xixiang; Shen, Bo

    2016-02-10

    Lattice-polarity-driven epitaxy of hexagonal semiconductor nanowires (NWs) is demonstrated on InN NWs. In-polarity InN NWs form typical hexagonal structure with pyramidal growth front, whereas N-polarity InN NWs slowly turn to the shape of hexagonal pyramid and then convert to an inverted pyramid growth, forming diagonal pyramids with flat surfaces and finally coalescence with each other. This contrary growth behavior driven by lattice-polarity is most likely due to the relatively lower growth rate of the (0001̅) plane, which results from the fact that the diffusion barriers of In and N adatoms on the (0001) plane (0.18 and 1.0 eV, respectively) are about 2-fold larger in magnitude than those on the (0001̅) plane (0.07 and 0.52 eV), as calculated by first-principles density functional theory (DFT). The formation of diagonal pyramids for the N-polarity hexagonal NWs affords a novel way to locate quantum dot in the kink position, suggesting a new recipe for the fabrication of dot-based devices.

  8. The macroscopic polarization effect on thermal conductivity of binary nitrides

    NASA Astrophysics Data System (ADS)

    Sahoo, S. K.; Sahoo, B. K.; Sahoo, S.

    2013-10-01

    We theoretically investigate the effect of macroscopic polarization on phonon thermal conductivity of wurtzite (WZ) binary nitrides (AlN, GaN and InN). Our results show that macroscopic polarization contributes to the effective elastic constant of the wurtzite nitrides and modifies the phonon group velocity, Debye frequency, and Debye temperature. Using revised phonon velocity and Debye temperature, different phonon scattering rates and combined scattering rate are calculated as functions of the phonon frequency at room temperature. We estimate phonon thermal conductivity of binary nitrides using these modified parameters. The theoretical analysis shows that up to a certain temperature (different for AlN, GaN, and InN) the polarization effect acts as ill effect and reduces the thermal conductivity. However, after this temperature, the thermal conductivity is significantly enhanced by the polarization effect. The revised thermal conductivity at room temperature is found to be increased by 12% in GaN, 18% in InN and 20% in case of AlN due to macroscopic polarization, i.e., maximum polarization effect is observed in AlN and minimum in GaN. The method we have developed can be used for calculation of thermal energy in the active region of nitride optoelectronic devices.

  9. InN/InGaN multiple quantum wells emitting at 1.5 {mu}m grown by molecular beam epitaxy

    SciTech Connect

    Grandal, J.; Pereiro, J.; Bengoechea-Encabo, A.; Fernandez-Garrido, S.; Sanchez-Garcia, M. A.; Munoz, E.; Calleja, E.

    2011-02-07

    This work reports on the growth by molecular beam epitaxy and characterization of InN/InGaN multiple quantum wells (MQWs) emitting at 1.5 {mu}m. X-ray diffraction (XRD) spectra show satellite peaks up to the second order. Estimated values of well (3 nm) and barrier (9 nm) thicknesses were derived from transmission electron microscopy and the fit between experimental data and simulated XRD spectra. Transmission electron microscopy and XRD simulations also confirmed that the InGaN barriers are relaxed with respect to the GaN template, while the InN MQWs grew under biaxial compression on the InGaN barriers. Low temperature (14 K) photoluminescence measurements reveal an emission from the InN MQWs at 1.5 {mu}m. Measurements as a function of temperature indicate the existence of localized states, probably due to InN quantum wells' thickness fluctuations as observed by transmission electron microscopy.

  10. [What are the reasons for patient dropout in nursing home residents in an intervention study. An analysis of unit nonresponders in 12 German nursing homes].

    PubMed

    Budnick, Andrea; Jordan, Laura-Maria; Könner, Franziska; Hannemann, Bianca; Wulff, Ines; Kalinowski, Sonja; Kreutz, Reinhold; Dräger, Dagmar

    2015-02-01

    Hintergrund: Nonresponse verursacht zweifelsohne ein Bias in Studienergebnissen. Ausfallursachen in Studien mit Pflegeheimbewohner(inne)n sind bisher unzureichend untersucht. Ziel und Methode: Ziel dieser Studie war es, nach dem Prozessmodell induktiver Kategorienbildung nach Mayring (2010) reliable und valide Kategorien zu entwickeln, welche detailliert Ausfallgründe von Pflegeheimbewohner(inne)n abbilden. Zudem wurden Charakteristika der Unit-Nonresponder und der Responder verglichen. Ergebnisse: Die Kategorisierung der Ausfallgründe erfolgte im Längsschnitt mit insgesamt 522 Pflegeheimbewohner(inne)n. Identifiziert wurden vier Oberkategorien («generelle Ablehnung», «gesundheitliche Aspekte», «Erreichbarkeit», «Überforderung») sowie 17 Subkategorien. Unit-Nonresponder und Responder unterscheiden sich hinsichtlich Alter und Geschlecht nicht; jedoch zeigten sich Unterschiede im Follow-up bei Familienstand, Berufsabschluss und kognitivem Status. Schlussfolgerungen: Das vorgelegte Kategorienschema kann zukünftig zur Erfassung von Ausfallgründen im Setting Pflegeheim verwendet werden. Die detaillierte Erfassung der Ausfallursachen kann zur Optimierung der Responserate beitragen.

  11. Near surface characteristics of foehn winds

    NASA Astrophysics Data System (ADS)

    Stiperski, Ivana

    2015-04-01

    Downslope windstorms occur commonly in mountainous regions around the world. Their importance is particularly great for air traffic, as well as wind energy, air pollution but also for ice shelf stability in the Antarctica, or deep water formation of the mountainous coasts. In this work we will focus on the foehn type of downslope windstorms and examine it's near surface turbulence characteristics in the Inn Valley, Austria. The foehn in the Inn Valley has been extensively studied throughout the past century, especially in several intensive campaigns. However, the smaller scale turbulence characteristics have only received limited attention. Here we present results from foehn episodes spanning over a year of data. The turbulence measurements at 5 stations within the Inn Valley, Austria as part of the i-Box project are used for the analysis. The general near surface turbulence characteristics of these events are examined and the characteristic scales of dominant transport are determined. Their dependence to horizontal heterogeneity is investigated both on the mesoscale and sub-mesoscale. Special focus is places on the question of energy balance closure during foehn episodes and the influence of advection.

  12. Infrared study of the absorption edge of {beta}-InN films grown on GaN/MgO structures

    SciTech Connect

    Perez-Caro, M.; Rodriguez, A. G.; Vidal, M. A.; Navarro-Contreras, H.

    2010-07-15

    Infrared optical studies were carried out in a group of cubic InN samples grown by gas source molecular beam epitaxy on MgO (001) substrates. Room temperature (RT) reflectance and low-temperature (LT) transmittance measurements were performed by using fast Fourier transform infrared spectrometry. Reflectance fittings allowed to establish that {beta}-InN films have large free-carrier concentrations present (>10{sup 19} cm{sup -3}), a result that is corroborated by Hall effect measurements. Each sample explored exhibited a different optical absorption edge. The Varshni parameters that describe adequately the optical absorption edge responses with temperature are obtained for the set of samples studied. The observed temperatures changes, from LT to RT, are the lowest reported for III-V semiconductor binary compounds. The temperature coefficient of the conduction band depends on the strength of the electron-phonon interaction (e-ph-i), as well as on the thermal expansion. It has been predicted that cubic InN has one of the smallest e-ph-i of all III-V compounds, which is corroborated by these results. The variation in values of absorption edges is clearly consistent with the Burstein-Moss and band renormalization effects, produced by high free electron concentrations. It is shown that the conduction band in {beta}-InN, analogous to wurtzite InN, follows a nonparabolic behavior.

  13. Indium nitride and gallium nitride grown from the melt at subatmospheric pressures

    NASA Astrophysics Data System (ADS)

    Dyck, Jeffrey Scott

    The wide-band-gap, group III nitride semiconductors (Al,Ga,In)N are a promising system for visible/near-UV optoelectronic devices. Despite significant technological advances, improvement in material quality is required. Moreover, pure InN has received little attention due to unavailability of high quality crystals, and uncertainty on the fundamental properties of InN exist in the literature. In this work, bulk, polycrystalline gallium nitride and indium nitride were synthesized without a substrate by saturating gallium or indium metal with atomic nitrogen from both ECR and ball plasma microwave sources. The results show that atomic nitrogen is an attractive alternative to high pressure N2 for the synthesis of the bulk nitrides. The GaN and InN crystals were confirmed to be wurtzitic by x-ray and electron diffraction. Weak yellow-band photoluminescence intensity and near-band-edge linewidths of 4 meV for some GaN crystals indicated high optical quality. The high crystalline quality of the InN crystals allowed for the most precise measurement of the lattice parameters currently possible: a = 3.5366 A, c = 5.7009 A. Raman spectra of InN were taken from both randomly oriented polycrystals and groups of oriented, faceted platelets. Phonon modes were assigned as ETO1=445cm -1,ATO1 =472cm-1, E22=448 cm-1, and ALO1=558 cm-1 , and previous disagreement in the literature is explained. The E22 and ALO1 linewidths of were 2.5 and 19 cm-1 are the narrowest ever reported. The measured TO phonon frequencies and lattice parameters were compared to those calculated from first principles and excellent agreement was found. Preliminary experiments on the growth of GaN from Ga/In alloys were performed. Addition of inert, soluble third elements to the Ga/N melt depresses the liquidus temperature, which is equivalent to increasing the solubility of GaN at constant temperature. Upon introduction of an (0001) sapphire substrate into the melt, oriented thin films of the solid nitride formed

  14. Band anticrossing effects in highly mismatched semiconductor alloys

    SciTech Connect

    Wu, Junqiao

    2002-09-09

    localized states and the valence band states. Soft x-ray fluorescence experiments provide direct evidence of the BAC interaction in these systems. In the final chapter of the thesis, I describe and summarize my studies of optical properties of wurtzite InN and related alloys. Early studies performed on InN films grown by sputtering techniques suggested a direct bandgap of {approx}1.9 eV for this semiconductor. Very recently, high-quality InN films with much higher mobility have become available by using the molecular beam epitaxy growth method. Optical experiments carried out on these samples reveal a narrow bandgap for InN of 0.77 eV, much lower than the previously accepted value. Optical properties of InGaN and InAlN ternaries on the In rich side have also been characterized and are found to be consistent with the narrow bandgap of InN. The bandgap bowing parameters in these alloys were determined. In the context of these findings, the bandgap energies of InGaN and InAlN were found to cover a wide spectral range from the infrared for InN to the ultraviolet for GaN and deep ultraviolet for AlN. The significance of this work is rooted in many important applications of nitride semiconductors in optoelectronics and solar energy conversion devices.

  15. Morphology and composition controlled growth of polar c-axis and nonpolar m-axis well-aligned ternary III-nitride nanotube arrays

    NASA Astrophysics Data System (ADS)

    Li, Huijie; Zhao, Guijuan; Kong, Susu; Han, Dongyue; Wei, Hongyuan; Wang, Lianshan; Chen, Zhen; Yang, Shaoyan

    2015-10-01

    Control over the nanostructure morphology and growth orientation is in high demand for fundamental research and technological applications. Herein we report a general strategy to fabricate polar c-axis and nonpolar m-axis well-aligned III-nitride ternary nanotube arrays with controllable morphologies and compositions. By depositing AlN on the InN nanorod array templates and thermally removing the InN templates, InAlN nanotubes can be obtained. Polar c-axis and nonpolar m-axis nanotubes were formed on the c- and r-plane sapphire substrates, respectively. The nanotubes are single crystalline and highly ordered on the substrates, as revealed by X-ray diffraction, electron microscopy, and selected area electron microscopy characterization. It was found that the In droplets on top of the InN nanorods play a critical role in controlling the morphology of the nanotubes. By keeping or removing the In droplets, the obtained nanotubes exhibited both ends open or only one end open. And by varying the AlN deposition temperature, the In composition in the nanotubes can be changed from 0 to 0.29. The nanotube synthesis method is simple and can be applied to the formation of other III-nitride ternary (InGaN, and AlGaN) or quaternary (InAlGaN) alloy nanotube arrays.Control over the nanostructure morphology and growth orientation is in high demand for fundamental research and technological applications. Herein we report a general strategy to fabricate polar c-axis and nonpolar m-axis well-aligned III-nitride ternary nanotube arrays with controllable morphologies and compositions. By depositing AlN on the InN nanorod array templates and thermally removing the InN templates, InAlN nanotubes can be obtained. Polar c-axis and nonpolar m-axis nanotubes were formed on the c- and r-plane sapphire substrates, respectively. The nanotubes are single crystalline and highly ordered on the substrates, as revealed by X-ray diffraction, electron microscopy, and selected area electron microscopy

  16. Bias-free lateral terahertz emitters—A simulation study

    SciTech Connect

    Granzner, R. Schwierz, F.; Polyakov, V. M.; Cimalla, V.; Ambacher, O.

    2015-07-28

    The design and performance of bias-free InN-based THz emitters that exploit lateral photocurrents is studied by means of numerical simulations. We use a drift-diffusion model with adjusted carrier temperatures and mobilities. The applicability of this approach is demonstrated by a comparison with results from Monte-Carlo simulations. We consider a simple but robust lateral emitter concept using metal stripes with two different thicknesses with one of them being thin enough to be transparent for THz radiation. This arrangement can be easily multiplexed and the efficiency of this concept has already been demonstrated by experiment for GaAs substrates. In the present study, we consider InN, which is known to be an efficient photo-Dember emitter because of its superior transport properties. Our main focus is on the impact of the emitter design on the emission efficiency assuming different operation principles. Both the lateral photo-Dember (LPD) effect and built-in lateral field effects are considered. The appropriate choice of the metal stripe and window geometry as well as the impact of surface Fermi level pinning are investigated in detail, and design guidelines for efficient large area emitters using multiplexed structures are provided. We find that InN LPD emitters do not suffer from Fermi level pinning at the InN surface. The optimum emission efficiency is found for LPD emitter structures having 200 nm wide illumination windows and mask stripes. Emitter structures in which lateral electric fields are induced by the metal mask contacts can have a considerably higher efficiency than pure LPD emitters. In the best case, the THz emission of such structures is increased by one order of magnitude. Their optimum window size is 1 μm without the necessity of a partially transparent set of mask stripes.

  17. 41. THE BEAR PIT (OLD SIDE DINING ROOM). THE ETCHINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. THE BEAR PIT (OLD SIDE DINING ROOM). THE ETCHINGS ON THE CEILING BEAMS AND COLUMNS OF PARK WILDLIFE ARE ORIGINAL TO THE OLD SIDE DINING ROOM. THE SIDE DINING ROOM WAS DESIGNED AND BUILT BY ROBERT REAMER IN 1927. IN 1962 WHEN IT WAS CONVERTED INTO THE BEAR PIT A WALL WAS ADDED BETWEEN THE THREE COLUMNS THAT SEPARATE THIS ROOM FROM THE MAIN DINING ROOM. THE ORIGINAL BEAR PIT ETCHINGS DEPICTING BEARS TENDING BAR AND PLAYING THE PIANO WERE MOUNTED ON THE WALL BETWEEN THE COLUMNS. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  18. Proceedings of the Annual Solar Thermal Technology Research and Development Conference

    NASA Astrophysics Data System (ADS)

    Couch, W. A.

    1989-02-01

    The Annual Solar Thermal Technology Research and Development Conference is being held at the Holiday Inn Crowne Plaza in Arlington, Virgina, March 8 and 9, 1989. This year the conference is meeting in conjunction with SOLTECH '89. SOLTECH '89 is a jointly sponsored meeting of the Solar Energy Industries Association, Interstate Solar Coordination Council, Sandia National Laboratories and the Solar Energy Research Institute. This report contains the agenda, extended abstracts and most significant visual aids used by the speakers during the Solar Thermal Technology research and development sessions. The program is divided into three sessions: Solar Electric Technology, Non-Electric Research and Development and Applications, and Concentrators.

  19. International Atomic Energy Agency specialists meeting on experience in ageing, maintenance, and modernization of instrumentation and control systems for improving nuclear power plant availability

    SciTech Connect

    Not Available

    1993-10-01

    This report presents the proceedings of the Specialist`s Meeting on Experience in Aging, Maintenance and Modernization of Instrumentation and Control Systems for Improving Nuclear Power Plant Availability that was held at the Ramada Inn in Rockville, Maryland on May 5--7, 1993. The Meeting was presented in cooperation with the Electric Power Research Institute, Oak Ridge National Laboratory and the International Atomic Energy Agency. There were approximately 65 participants from 13 countries at the Meeting. Individual reports have been cataloged separately.

  20. Proceedings of the 2011 Space Cryogenics Workshop: "Poised for the Future, Reflecting on the Past"

    NASA Technical Reports Server (NTRS)

    Johnson, W. L. (Editor); Schnell, A. R. (Editor); Huget, L. (Editor)

    2013-01-01

    The 24th Space Cryogenics Workshop was held at the Best Western Coeur d Alene Inn and Conference Center, Coeur d Alene, Idaho, June 8-10, 2011. The workshop was organized and sponsored by NASA Kennedy Space Center and NASA Marshall Space Flight Center, with a theme of "Poised for the Future, Reflecting on the Past." Over 100 scientists and engineers from around the world came together to discuss space applications for cryogenics, renew old acquaintances, and meet new practitioners in the field of space cryogenics.

  1. Improved conversion efficiency of InN/p-GaN heterostructure solar cells with embedded InON quantum dots

    NASA Astrophysics Data System (ADS)

    Ke, Wen-Cheng; Liang, Zhong-Yi; Yang, Cheng-Yi; Chan, Yu-Teng; Jiang, Chi-Yung

    2016-02-01

    An indium oxynitride (InON) quantum dot (QD) layer was inserted between the indium nitride (InN) and p-type gallium nitride (GaN) films for improving the conversion efficiency of the heterostructure solar cells. The InN/InON QD/p-GaN heterostructure solar cells exhibited a high open-circuit voltage of 2.29 V, short-circuit current density of 1.64 mA/cm2, and conversion efficiency of 1.12% under AM 1.5G illumination. Compared with samples without InON QDs, the power conversion efficiency of sample with InON QDs increased twofold; this increase was attributed to the increase in short-current density. The external quantum efficiency of 250-nm-thick InN/p-GaN heterostructure solar cells has a highest value of 6.5% in the wavelength range of 700-1100 nm. The photogenerated holes separated in the depletion region of InN thin films is difficult to transport across the energy barrier between the InN and p-GaN layers. The oxygen vacancy assisted carrier transport in the InN/InON QD/p-GaN sample, which was evidenced in its current-voltage (I-V) and capacitance-voltage (C-V) characteristics. The dark I-V characteristic curves in the bias range of -2 to 2 V exhibited ohmic behavior, which indicated the absence of a transport barrier between the InN and p-GaN layers. In addition, a shoulder peak at -0.08 V was observed in the high-frequency (60-100 kHz) C-V characteristic curves corresponding to carrier capture and emission in the shallow defect state of oxygen vacancy in the InON QDs. The oxygen vacancy exists inside the InON QDs and generates the interface states in the InON QD/p-GaN interface to form a carrier transport path. Thus, more photogenerated holes can transport via the InON QDs into the p-GaN layer, contributing to the photocurrent and resulting in high conversion efficiency for the InN/InON QD/p-GaN heterostructure solar cells.

  2. Third International Symposium on Magnetic Suspension Technology. Part 2

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1996-01-01

    In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Third International Symposium on Magnetic Suspension Technology was held at the Holiday Inn Capital Plaza in Tallahassee, Florida on 13-15 Dec. 1995. The symposium included 19 sessions in which a total of 55 papers were presented. The technical sessions covered the areas of bearings, superconductivity, vibration isolation, maglev, controls, space applications, general applications, bearing/actuator design, modeling, precision applications, electromagnetic launch and hypersonic maglev, applications of superconductivity, and sensors.

  3. An interview with Caroline Dean.

    PubMed

    Dean, Caroline; Vicente, Catarina

    2015-08-15

    Caroline Dean is a plant biologist based at the John Innes Centre in Norwich, UK. She helped to establish Arabidopsis as a model plant organism, and has worked for many years on the epigenetic mechanisms that regulate vernalisation, the process by which plants accelerate their flowering after periods of prolonged cold. We met Caroline at the recent Spring Meeting of the British Society for Developmental Biology. We asked her about her career, her thoughts on the plant field and being awarded this year's FEBS EMBO Women in Science Award. PMID:26286939

  4. CO quantum yield in the photolysis of CO2 at wavelength 1470 and wavelengths 1500-1670.

    NASA Technical Reports Server (NTRS)

    Inn, E. C. Y.

    1972-01-01

    The results of carbon monoxide quantum yield measurements of carbon dioxide photolysis by radiation at 1470 A and in the region from 1500 to 1670 A are presented in tabular form. The experimental technique and equipment developed by Inn and Heimerl (1971) were used. These measurements, together with some previously reported ones for a longer wavelength region, are intended to provide a uniform set of values based on the same experimental technique for the entire spectral region that is relevant to the carbon-dioxide photochemistry in the atmospheres of Mars and Venus.

  5. Summary of proceedings: Oklahoma and Texas wind energy forum, April 2-3, 1981

    SciTech Connect

    Nelson, S. C.; Ball, D. E.

    1981-06-01

    The Wind Energy Forum for Oklahoma and Texas was held at the Amarillo Quality Inn in Amarillo, Texas on April 2-3, 1981. Its purpose was to bring together the diverse groups involved in wind energy development in the Oklahoma and Texas region to explore the future commercial potential and current barriers to achieving this potential. Major topics of discussion included utility interconnection of wind machines and the buy-back rate for excess power, wind system reliability and maintenance concerns, machine performance standards, and state governmental incentives. A short summary of each presentation is included.

  6. Ernest Orlando Lawrence Awards Ceremony for 2011 Award Winners (Presentations, including remarks by Energy Secretary, Dr. Steven Chu)

    SciTech Connect

    Chu, Steven

    2012-05-21

    The winners for 2011 of the Department of Energy's Ernest Orlando Lawrence Award were recognized in a ceremony held May 21, 2012. Dr. Steven Chu and others spoke of the importance of the accomplishments and the prestigious history of the award. The recipients of the Ernest Orlando Lawrence Award for 2011 are: Riccardo Betti (University of Rochester); Paul C. Canfield (Ames Laboratory); Mark B. Chadwick (Los Alamos National Laboratory); David E. Chavez (Los Alamos National Laboratory); Amit Goyal (Oak Ridge National Laboratory); Thomas P. Guilderson (Lawrence Livermore National Laboratory); Lois Curfman McInnes (Argonne National Laboratory); Bernard Matthew Poelker (Thomas Jeffereson National Accelerator Facility); and Barry F. Smith (Argonne National Laboratory).

  7. Wet Chemical Etching Survey of III-Nitrides

    SciTech Connect

    Abernathy, C.R.; Cho, H.; Hays, D.C.; MacKenzie, J.D.; Pearton, S.J.; Ren, F.; Shul, R.J.; Vartuli, C.B.; Zolper, J.C.

    1999-02-04

    Wet chemical etching of GaN, InN, AlN, InAlN and InGaN was investigated in various acid and base solutions at temperatures up to 75 C. Only KOH-based solutions were found to etch AlN and InAlN. No etchants were found for the other nitrides, emphasizing their extreme lack of chemical reactivity. The native oxide on most of the nitrides could be removed in potassium tetraborate at 75 C, or HCl/H{sub 2}O at 25 C.

  8. Prescribing generic drugs using a generic name: Are we teaching it right?

    PubMed

    Kamath, Ashwin

    2016-01-01

    The Indian Medical Council (Professional conduct, Etiquette and Ethics) Regulations, 2002, state that "Every physician should, as far as possible, prescribe drugs with generic names and he/she shall ensure that there is a rational prescription and use of drugs.". Undergraduate medical students are introduced to drug nomenclature early on during their pharmacology course. They are told that generic name or, more appropriately, non-proprietary name (usually international non-proprietary name INN), is to be used while writing prescriptions. PMID:27474700

  9. Ernest Orlando Lawrence Awards Ceremony for 2011 Award Winners (Presentations, including remarks by Energy Secretary, Dr. Steven Chu)

    ScienceCinema

    Chu, Steven (U.S. Energy Secretary)

    2016-07-12

    The winners for 2011 of the Department of Energy's Ernest Orlando Lawrence Award were recognized in a ceremony held May 21, 2012. Dr. Steven Chu and others spoke of the importance of the accomplishments and the prestigious history of the award. The recipients of the Ernest Orlando Lawrence Award for 2011 are: Riccardo Betti (University of Rochester); Paul C. Canfield (Ames Laboratory); Mark B. Chadwick (Los Alamos National Laboratory); David E. Chavez (Los Alamos National Laboratory); Amit Goyal (Oak Ridge National Laboratory); Thomas P. Guilderson (Lawrence Livermore National Laboratory); Lois Curfman McInnes (Argonne National Laboratory); Bernard Matthew Poelker (Thomas Jeffereson National Accelerator Facility); and Barry F. Smith (Argonne National Laboratory).

  10. Photoelectrochemical Etching of In(x)Ga(1-x)N

    SciTech Connect

    Cho, H.; Donovan, S.M.; Abernathy, C.R.; Pearton, S.J.; Ren, F.; Han, J.; Shul, R.J.

    1999-01-20

    A comparison of KOH, NaOH and AZ400K solutions for UV photo-assisted etching of undoped and n{sup +} GaN is discussed. The etching is diffusion-limited (E{sub a} < 6kCal {center_dot} mol{sup {minus}1} ) under all conditions and is significantly faster with bias applied to the sample during light exposure. No etching of InN was observed, due to the very high n-type background doping (> 10{sup 20} cm{sup {minus}3}) in the material.

  11. Competition in prescription drug markets: the roles of trademarks, advertising, and generic names.

    PubMed

    Feldman, Roger; Lobo, Félix

    2013-08-01

    We take on two subjects of controversy among economists-advertising and trademarks-in the context of the market for generic drugs. We outline a model in which trademarks for drug names reduce search costs but increase product differentiation. In this particular framework, trademarks may not benefit consumers. In contrast, the generic names of drugs or "International Nonproprietary Names" (INN) have unquestionable benefits in both economic theory and empirical studies. We offer a second model where advertising of a brand-name drug creates recognition for the generic name. The monopoly patent-holder advertises less than in the absence of a competitive spillover. PMID:22815099

  12. Proceedings of the 2013 MidSouth Computational Biology and Bioinformatics Society (MCBIOS) Conference.

    PubMed

    Wren, Jonathan D; Dozmorov, Mikhail G; Burian, Dennis; Kaundal, Rakesh; Perkins, Andy; Perkins, Ed; Kupfer, Doris M; Springer, Gordon K

    2013-01-01

    The tenth annual conference of the MidSouth Computational Biology and Bioinformatics Society (MCBIOS 2013), "The 10th Anniversary in a Decade of Change: Discovery in a Sea of Data", took place at the Stoney Creek Inn & Conference Center in Columbia, Missouri on April 5-6, 2013. This year's Conference Chairs were Gordon Springer and Chi-Ren Shyu from the University of Missouri and Edward Perkins from the US Army Corps of Engineers Engineering Research and Development Center, who is also the current MCBIOS President (2012-3). There were 151 registrants and a total of 111 abstracts (51 oral presentations and 60 poster session abstracts).

  13. An interview with Caroline Dean.

    PubMed

    Dean, Caroline; Vicente, Catarina

    2015-08-15

    Caroline Dean is a plant biologist based at the John Innes Centre in Norwich, UK. She helped to establish Arabidopsis as a model plant organism, and has worked for many years on the epigenetic mechanisms that regulate vernalisation, the process by which plants accelerate their flowering after periods of prolonged cold. We met Caroline at the recent Spring Meeting of the British Society for Developmental Biology. We asked her about her career, her thoughts on the plant field and being awarded this year's FEBS EMBO Women in Science Award.

  14. A Stellar Highway

    NASA Astrophysics Data System (ADS)

    Rijsdijk, Case

    2015-10-01

    Thomas Henderson, at the Royal Observatory of the Cape, was the first person to measure the distance to a star in 1834. Robert Innes, at the Union Observatory in Johannesburg, discovered that Proxima Centauri was the nearest star to the Sun in 1915. The idea of marking the 100th anniversary of the discovery of Proxima Centauri in 2015 led to the development of a Stellar Highway, similar to the well-known scale models of the Solar System or Planetary Highways, but showing the scaled distance between stars.

  15. Aviation Safety/Automation Program Conference

    NASA Technical Reports Server (NTRS)

    Morello, Samuel A. (Compiler)

    1990-01-01

    The Aviation Safety/Automation Program Conference - 1989 was sponsored by the NASA Langley Research Center on 11 to 12 October 1989. The conference, held at the Sheraton Beach Inn and Conference Center, Virginia Beach, Virginia, was chaired by Samuel A. Morello. The primary objective of the conference was to ensure effective communication and technology transfer by providing a forum for technical interchange of current operational problems and program results to date. The Aviation Safety/Automation Program has as its primary goal to improve the safety of the national airspace system through the development and integration of human-centered automation technologies for aircraft crews and air traffic controllers.

  16. Third International Symposium on Magnetic Suspension Technology

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1996-01-01

    In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Third International Symposium on Magnetic Suspension Technology was held at the Holiday Inn Capital Plaza in Tallahassee, Florida on 13-15 Dec. 1995. The symposium included 19 sessions in which a total of 55 papers were presented. The technical sessions covered the areas of bearings, superconductivity, vibration isolation, maglev, controls, space applications, general applications, bearing/actuator design, modeling, precision applications, electromagnetic launch and hypersonic maglev, applications of superconductivity, and sensors.

  17. Solar hot water system installed at Mobile, Alabama. Final report

    SciTech Connect

    1980-10-01

    This final report describes the solar energy hot water system installed at LaQuinta Motor Inn Inc., at Mobile, Alabama. The building is a 122 unit motel. The system consists of six rows of ten collectors and three rows of eleven collectors (1990 square feet) mounted on the roof. Griswald flow control valves were installed to regulate the flow to each row. Two Heliotrope electronic thermometers with a combined capability of measuring the temperatures of 22 different locations were installed for monitoring purposes. Engineering drawings, component specifications, and operator instructions are included.

  18. Orthogonal and Non-Orthogonal Tight Binding Parameters for III-V Semiconductors Nitrides

    NASA Astrophysics Data System (ADS)

    Martins, A. S.; Fellows, C. E.

    2016-08-01

    A simulated annealing (SA) approach is employed in the determination of different tight binding (TB) sets of parameters for the nitride semiconductors AlN, GaN and InN, as well their limitations and potentialities are also discussed. Two kinds of atomic basis set are considered: (i) the orthogonal sp 3 s∗ with interaction up to second neighbors and (ii) a spd non-orthogonal set, with the Hamiltonian matrix elements calculated within the Extended Hückel Theory (EHT) prescriptions. For the non-orthogonal method, TB parameters are given for both zincblend and wurtzite crystalline structures.

  19. Searching for inhibition of return in visual search: a review.

    PubMed

    Wang, Zhiguo; Klein, Raymond M

    2010-01-01

    Studies that followed the covert and overt probe-following-search paradigms of Klein (1988) and Klein and MacInnes (1999) to explore inhibition of return (IOR) in search are analyzed and evaluated. An IOR effect is consistently observed when the search display (or scene) remains visible when probing and lasts for at least 1000ms or about four previous inspected items (or locations). These findings support the idea that IOR facilitates foraging by discouraging orienting toward previously examined regions and items. Methodological and conceptual issues are discussed leading to methodological recommendations and suggestions for experimentation.

  20. Anisotropy of the nitrogen conduction states in the group III nitrides studied by polarized x-ray absorption

    SciTech Connect

    Lawniczak-Jablonska, K. |; Liliental-Weber, Z.; Gullikson, E.M.

    1997-04-01

    Group III nitrides (AlN, GaN, and InN) consist of the semiconductors which appear recently as a basic materials for optoelectronic devices active in the visible/ultraviolet spectrum as well as high-temperature and high-power microelectronic devices. However, understanding of the basic physical properties leading to application is still not satisfactory. One of the reasons consists in unsufficient knowledge of the band structure of the considered semiconductors. Several theoretical studies of III-nitrides band structure have been published but relatively few experimental studies have been carried out, particularly with respect to their conduction band structure. This motivated the authors to examine the conduction band structure projected onto p-states of the nitrogen atoms for AlN, GaN and InN. An additional advantage of their studies is the availability of the studied nitrides in two structures, hexagonal (wurtzite) and cubic (zincblende). This offers an opportunity to gain information about the role of the anisotropy of electronic band states in determining various physical properties.

  1. Thermodynamic theory of epitaxial alloys: first-principles mixed-basis cluster expansion of (In, Ga)N alloy film.

    PubMed

    Liu, Jefferson Zhe; Zunger, Alex

    2009-07-22

    Epitaxial growth of semiconductor alloys onto a fixed substrate has become the method of choice to make high quality crystals. In the coherent epitaxial growth, the lattice mismatch between the alloy film and the substrate induces a particular form of strain, adding a strain energy term into the free energy of the alloy system. Such epitaxial strain energy can alter the thermodynamics of the alloy, leading to a different phase diagram and different atomic microstructures. In this paper, we present a general-purpose mixed-basis cluster expansion method to describe the thermodynamics of an epitaxial alloy, where the formation energy of a structure is expressed in terms of pair and many-body interactions. With a finite number of first-principles calculation inputs, our method can predict the energies of various atomic structures with an accuracy comparable to that of first-principles calculations themselves. Epitaxial (In, Ga)N zinc-blende alloy grown on GaN(001) substrate is taken as an example to demonstrate the details of the method. Two (210) superlattice structures, (InN)(2)/(GaN)(2) (at x = 0.50) and (InN)(4)/(GaN)(1) (at x = 0.80), are identified as the ground state structures, in contrast to the phase-separation behavior of the bulk alloy. PMID:21828531

  2. Hydrological modeling in alpine catchments: sensing the critical parameters towards an efficient model calibration.

    PubMed

    Achleitner, S; Rinderer, M; Kirnbauer, R

    2009-01-01

    For the Tyrolean part of the river Inn, a hybrid model for flood forecast has been set up and is currently in its test phase. The system is a hybrid system which comprises of a hydraulic 1D model for the river Inn, and the hydrological models HQsim (Rainfall-runoff-discharge model) and the snow and ice melt model SES for modeling the rainfall runoff form non-glaciated and glaciated tributary catchment respectively. Within this paper the focus is put on the hydrological modeling of the totally 49 connected non-glaciated catchments realized with the software HQsim. In the course of model calibration, the identification of the most sensitive parameters is important aiming at an efficient calibration procedure. The indicators used for explaining the parameter sensitivities were chosen specifically for the purpose of flood forecasting. Finally five model parameters could be identified as being sensitive for model calibration when aiming for a well calibrated model for flood conditions. In addition two parameters were identified which are sensitive in situations where the snow line plays an important role.

  3. Hydrological modeling in alpine catchments: sensing the critical parameters towards an efficient model calibration.

    PubMed

    Achleitner, S; Rinderer, M; Kirnbauer, R

    2009-01-01

    For the Tyrolean part of the river Inn, a hybrid model for flood forecast has been set up and is currently in its test phase. The system is a hybrid system which comprises of a hydraulic 1D model for the river Inn, and the hydrological models HQsim (Rainfall-runoff-discharge model) and the snow and ice melt model SES for modeling the rainfall runoff form non-glaciated and glaciated tributary catchment respectively. Within this paper the focus is put on the hydrological modeling of the totally 49 connected non-glaciated catchments realized with the software HQsim. In the course of model calibration, the identification of the most sensitive parameters is important aiming at an efficient calibration procedure. The indicators used for explaining the parameter sensitivities were chosen specifically for the purpose of flood forecasting. Finally five model parameters could be identified as being sensitive for model calibration when aiming for a well calibrated model for flood conditions. In addition two parameters were identified which are sensitive in situations where the snow line plays an important role. PMID:19759453

  4. Spectroscopic studies of In2O3 nanostructures; photovoltaic demonstration of In2O3/p-Si heterojunction.

    PubMed

    Bhat, Thirumaleshwara N; Roul, Basanta; Rajpalke, Mohana K; Kumar, Mahesh; Krupanidhi, S B

    2013-01-01

    The thermal oxidation process of the indium nitride (InN) nanorods (NRs) was studied. The SEM studies reveal that the cracked and burst mechanism for the formation of indium oxide (In2O3) nanostructures by oxidizing the InN NRs at higher temperatures. XRD results confirm the bcc crystal structure of the as prepared In2O3 nanostructures. Strong and broad photoluminescence spectrum located at the green to red region with maximum intensity at 566 nm along with a weak ultraviolet emission at 338 nm were observed due to oxygen vacancy levels and free excitonic transitions, respectively. The valence band onset energy of 2.1 eV was observed from the XPS valence band spectrum, clearly justifies the alignment of Fermi level to the donor level created due to the presence of oxygen vacancies which were observed in the PL spectrum. The elemental ratio In:O in as prepared In2O3 was found to be 42:58 which is in close agreement with the stoichiometric value of 40:60. A downward shift was observed in the Raman peak positions due to a possible phonon confinement effect in the nanoparticles formed in bursting mechanism. Such single junction devices exhibit promising photovoltaic performance with fill factor and conversion efficiency of 21% and 0.2%, respectively, under concentrated AM1.5 illumination.

  5. Rare earth ion implantation and optical activation in nitride semiconductors for multicolor emission

    NASA Astrophysics Data System (ADS)

    Ruterana, Pierre; Chauvat, Marie-Pierre; Lorenz, Katharina

    2015-04-01

    In order to understand the behavior of nitride semiconductors when submitted to ion implantation, we have used 300 keV europium at fluences from 1012 to above 1017 ions cm-2. Subsequently, Rutherford backscattering (RBS), x-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to investigate the evolution of damage. The optical properties were investigated prior to and after annealing. It was found that the behavior of the three compounds (AlN, GaN InN) under ion implantation is rather different: whereas InN breaks down at very low fluences (˜1012 ions cm-2), the damage formation mechanisms are similar in AlN and GaN. In both compounds, extended defects such as stacking faults play a critical role. However, they exhibit different stability, as a consequence, GaN transforms to nanocrystalline state from the surface at a fluence of around 2.5 × 1015 ions cm-2, whereas AlN undergoes a chemical amorphization starting at the projected range (Rp), when implanted to extremely high Eu fluences >1017 ionscm-2. As for the optical activation, the formation of highly stable extended defects in these compounds constitutes a real challenge for the annealing of heavily doped layers, and it was noticed that for a substantial optical activation, the implantation fluences should be kept low (<1015 Eu at cm-2).

  6. Vacancy-type defects in In{sub x}Ga{sub 1−x}N grown on GaN templates probed using monoenergetic positron beams

    SciTech Connect

    Uedono, Akira; Watanabe, Tomohito; Kimura, Shogo; Zhang, Yang; Lozac'h, Mickael; Sang, Liwen; Sumiya, Masatomo; Ishibashi, Shoji; Oshima, Nagayasu; Suzuki, Ryoichi

    2013-11-14

    Native defects in In{sub x}Ga{sub 1−x}N layers grown by metalorganic chemical vapor deposition were studied using monoenergetic positron beams. Measurements of Doppler broadening spectra of the annihilation radiation and lifetime spectra of positrons for a 200-nm-thick In{sub 0.13}Ga{sub 0.87}N layer showed that vacancy-type defects were introduced by InN alloying, and the major species of such defects was identified as complexes between a cation vacancy and nitrogen vacancies. The presence of the defects correlated with lattice relaxation of the In{sub 0.13}Ga{sub 0.87}N layer and the increase in photon emissions from donor-acceptor-pair recombination. The species of native defects in In{sub 0.06}Ga{sub 0.94}N layers was the same but its concentration was decreased by decreasing the InN composition. With the layer thickness increased from 120 nm to 360 nm, a defect-rich region was introduced in the subsurface region (<160 nm), which can be associated with layer growth with the relaxation of compressive stress.

  7. Mesoporous InN/In2O3 heterojunction with improved sensitivity and selectivity for room temperature NO2 gas sensing

    NASA Astrophysics Data System (ADS)

    Qu, Fengdong; Liu, Honghong; Guarecuco, Rohiverth; Jiao, Yutong; Yang, Minghui

    2016-09-01

    Establishing heterostructures is a good strategy to improve gas sensing performance, and has been studied extensively. In this work, mesoporous InN/In2O3 composite (InNOCs) heterostructures were prepared through a simple two-step strategy involving hydrothermal synthesis of In2O3 and subsequent nitriding into InN-composite In2O3 heterostructures. We found that the InN content has great influence on the resistance of InNOCs, and thus, the gas sensing performance. In particular, InNOC-36.9 (with InN content of 36.9% in the composites) shows an excellent sensing response towards different concentrations of NO2, as well as good stability after one week of exposure to 200 ppb NO2 at room temperature. The highest sensing response (ΔR/R0 ) is up to 1.8 for the low NO2 concentration of 5 ppb. Even more significantly, the theoretical limit of detection (LOD) of the InNOC-36.9 sensor is 31.7 ppt based on a signal-to-noise ratio of 3 (the measured LOD is 5 ppb), which is far below the US NAAQS value (NO2: 53 ppb). In addition, a rational band structure model combined with a surface reaction model is proposed to explain the sensing mechanism.

  8. Indium tin oxide nanowires grown by one-step thermal evaporation-deposition process at low temperature.

    PubMed

    Dong, Haibo; Zhang, Xiaoxian; Niu, Zhiqiang; Zhao, Duan; Li, Jinzhu; Cai, Le; Zhou, Weiya; Xie, Sishen

    2013-02-01

    Indium tin oxide (ITO), as one of the most important transparent conducting oxide, is widely used in electro-optical field. We have developed a simple one-step method to synthesize ITO nanowires at low temperature of 600 degrees C. In detail, mixtures of InN nanowires and SnO powder, with the molar ratio of 10:1, have been used as precursors for the thermal evaporation-deposition of ITO nanowires on silicon/quartz slices. During the growth process, the evaporation temperature is maintained at 600 degrees C, which favors the decomposition of InN and oxidation of In, with a limited incorporation of Sn in the resulting compound (In:Sn approximately 11:1 in atomic ratio). As far as we know, this is the lowest growth temperature reported on the thermal deposition of ITO nanowires. The diameters of the nanowires are about 120 nm and the lengths are up to tens of micrometers. XRD characterization indicates the high crystallization of the nanowires. HRTEM results show the nanowires grow along the [200] direction. The transmittance of the nanowire film on quartz slice is more than 75% in the visible region. Based on photolithography and lift-off techniques, four-terminal measurement was utilized to test the resistivity of individual nanowire (6.11 x 10(-4) omega x cm). The high crystallization quality, good transmittance and low resistivity make as-grown ITO nanowires a promising candidate as transparent electrodes of nanoscale devices. PMID:23646624

  9. High spatial uniformity of photoluminescence spectra in semipolar (202{sup ¯}1) plane InGaN/GaN quantum wells

    SciTech Connect

    Gelžinytė, K.; Ivanov, R.; Marcinkevičius, S.; Zhao, Y.; Becerra, D. L.; Nakamura, S.; DenBaars, S. P.; Speck, J. S.

    2015-01-14

    Scanning near-field optical spectroscopy was applied to study spatial variations of emission spectra at room temperature in semipolar (202{sup ¯}1) In{sub x}Ga{sub 1−x}N/GaN single quantum wells (QWs) for 0.11≤x≤0.36. Photoluminescence (PL) was found to be highly uniform, with peak wavelength deviations and peak intensity deviations divided by average values in the range of 6–12 meV and 0.03–0.07, respectively. Near-field maps of PL parameters showed large, ∼5 to 10 μm size areas of similar values, as opposed to 100 nm scale variations, often reported for InGaN QWs. The near-field PL spectra were found to broaden with increasing InN molar fraction. In the low In content QWs, the broadening is primarily determined by the random cation distribution, while for larger InN molar fractions 10 nm scale localization sites with increasingly deeper band potentials are suggested as the linewidth broadening cause.

  10. First-principles LDA+U study of magnetism in CuxIn1-xN

    NASA Astrophysics Data System (ADS)

    González-García, Alvaro; López-Pérez, William; González-Hernández, Rafael

    2013-03-01

    We have carried out First-principles spin-polarized calculations in order to study the electronic structure and magnetism in Cu-doped InN using the LDA+U and LDA formalisms within density functional theory (DFT) with a plane-wave ultrasoft pseudopotential scheme. We found a stable ferromagnetic state in Cu0.0625In0.9375N with a total magnetization of 1.98μB per supercell, indicating Cu orders ferromagnetically in InN. The results indicate that the ferromagnetic ground state originates from the hybridized Cu(3d)-N(2p)-In(5p)-N(2p) chain formed through p-d coupling. Formation energy and ground state calculations have been performed for ferromagnetic and antiferromagnetic states of CuxIn1-xN (x=0,0625 and 0,125) by LDA+U and LDA formalisms. A weak ferromagnetic behavior for CuxIn1-xN (x=0,125) was found. The results predicted an AFM ground state for cases where the Cu atoms are closer. For longer Cu-Cu distances a stable FM ground state was found. This ferromagnetic behavior in CuxIn1-xN (x=0,125) could be tuned with In or N vacancies.

  11. Composition and luminescence of AlInGaN layers grown by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Bejtka, K.; Edwards, P. R.; Martin, R. W.; Fernandez-Garrido, S.; Calleja, E.

    2008-10-01

    A study of AlInGaN epilayers, grown by plasma-assisted molecular beam epitaxy, was performed using spatially resolved x-ray microanalysis and luminescence spectroscopy in order to investigate competition between the incorporation of In, Al, and Ga as a function of the growth temperature in the 565-660 deg. C range and the nominal AlN mole fraction. The samples studied have AlN and InN mole fractions in the ranges of 4%-30% and 0%-16%, respectively. Composition measurements show the effect of decreasing temperature to be an increase in the incorporation of InN, accompanied by a small but discernible decrease in the ratio of GaN to AlN mole fractions. The incorporation of In is also shown to be significantly increased by decreasing the Al mole fraction. Optical emission peaks, observed by cathodoluminescence mapping and by photoluminescence, provide further information on the epilayer compositions as a function of substrate temperature, and the dependencies of peak energy and linewidth are plotted.

  12. Fluorescence competition assay measurements of free energy changes for RNA pseudoknots.

    PubMed

    Liu, Biao; Shankar, Neelaabh; Turner, Douglas H

    2010-01-26

    RNA pseudoknots have important functions, and thermodynamic stability is a key to predicting pseudoknots in RNA sequences and to understanding their functions. Traditional methods, such as UV melting and differential scanning calorimetry, for measuring RNA thermodynamics are restricted to temperature ranges around the melting temperature for a pseudoknot. Here, we report RNA pseudoknot free energy changes at 37 degrees C measured by fluorescence competition assays. Sequence-dependent studies for the loop 1-stem 2 region reveal (1) the individual nearest-neighbor hydrogen bonding (INN-HB) model provides a reasonable estimate for the free energy change when a Watson-Crick base pair in stem 2 is changed, (2) the loop entropy can be estimated by a statistical polymer model, although some penalty for certain loop sequences is necessary, and (3) tertiary interactions can significantly stabilize pseudoknots and extending the length of stem 2 may alter tertiary interactions such that the INN-HB model does not predict the net effect of adding a base pair. The results can inform writing of algorithms for predicting and/or designing RNA secondary structures.

  13. Nucleus and spiral growth mechanisms of nitride semiconductors in metalorganic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Akasaka, Tetsuya; Yamamoto, Hideki

    2014-10-01

    Nucleus and spiral growth mechanisms of GaN and InN are investigated using the selective-area metalorganic vapor phase epitaxy (SA-MOVPE) technique on GaN bulk substrates. Nucleus growth of GaN occurs within selective areas having no screw-type dislocations, while spiral growth occurs within selective areas having screw-type dislocations. These growth modes are simultaneously observed on a single substrate in a single growth run. The nucleus and spiral growths of GaN result in the formation of step-free surfaces and growth spirals, respectively, wherein the interstep distance of growth spirals enables us to estimate the degree of surface supersaturation (σ). The σ dependences of nucleus and spiral growth rates of GaN are experimentally investigated. We found that these dependences are well explained by the classical crystal growth theories advocated by Burton, Cabrera, and Frank. We also investigate nucleation of InN using step-free GaN surfaces as an ideal platform.

  14. Electro-optic and magneto-dielectric properties of multifunctional nitride and oxide materials

    NASA Astrophysics Data System (ADS)

    Dixit, Ambesh

    Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties. Thin films of InN nitride compound semiconductors and closely related alloys have been investigated to understand the effects of intrinsic defects on the materials properties while considering possible applications of highly degenerate InN thin films. As grown rf sputtered InN films on c-axis (0001) sapphire exhibit highly degenerate n-type behaviour due to oxygen defects introduced during growth. The effect of oxygen in InN matrix has been further investigated by intentionally adding oxygen into the films. These studies confirm that oxygen is one of the main sources of donor electrons in degenerate InN. Above some critical concentration of oxygen, secondary phases of In 2O3 and In-O-N complexes were formed. It was also possible to tune the carrier concentration to produce changes in the plasmon frequency, which varied from 0.45 eV to 0.8 eV. This characteristic energy scale suggests that these highly degenerate InN thin films could be used for thermophotovoltaic cells, optical filters, and other IR electro-optic applications. To probe the magnetism in transition metal doped InN system, In 0.98Cr0.02N and In0.95Cr0.05N thin films were fabricated. Our results suggest that these films develop ferromagnetic order above room temperature

  15. Structural and optical characterization of group III-nitride compound semiconductors

    NASA Astrophysics Data System (ADS)

    Senawiratne, Jayantha

    The structural properties of the group III-nitrides including AlN, Ga 1-xMnxN, GaN:Cu, and InN were investigated by Raman spectroscopy. Absorption and photoluminescence spectroscopy were utilized to study the optical properties in these materials. The analysis of physical vapor transport grown AlN single crystals showed that oxygen, carbon, silicon, and boron are the major impurities in the bulk AlN. The Raman analysis revealed high crystalline quality and well oriented AlN single crystals. The absorption coefficient of AlN single crystals were assessed in the spectral range from deep UV to the FIR. The absorption and photoluminescence analysis indicate that, in addition to oxygen, carbon, boron, and silicon, contribute to the optical properties of bulk AlN crystals. In situ Cu-doped GaN epilayers with Cu concentrations in the range of 2x1016 cm-3 - 5x10 17 cm-3, grown on sapphire substrate by metal organic chemical vapor deposition, were investigated by Raman and photoluminescence (PL) spectroscopy. The Raman study revealed high crystalline GaN:Cu layers with minimal damage to the hexagonal lattice structure due to the Cu incorporation. A strong Cu related emission band at 2.4 eV was assigned to Cu induced optical transitions between deep Cu states and shallow residual donor states. Compensation of Cu states by residual donors and poor activation probability of deep Cu states are responsible for semi-insulating electrical conductivity. Ferromagnetic Ga1-xMnxN epilayers, grown by MOCVD with Mn concentration from x = 0 to x = 1.5, were optically investigated by Raman, PL, and transmission spectroscopy. The Raman studies revealed Mn-related Raman peaks at 300 cm-1, 609 cm-1, and 669 cm -1. Mn-related absorption and emission bands in Ga1-xMn xN were observed at 1.5 eV and 3.0 eV, respectively. The structural properties of InN layers, grown by high pressure-CVD with different free carrier concentrations, were analyzed by Raman spectroscopy. The Raman results show that

  16. Rapid thermal processing of III-nitrides

    SciTech Connect

    Hong, J.; Lee, J.W.; Vartuli, C.B.; Abernathy, C.R.; MacKenzie, J.D.; Donovan, S.M.; Pearton, S.J.; Zolper, J.C.

    1997-05-01

    High-temperature annealing is necessary in a number of applications for III-nitrides, including activation of Si{sup +} or Mg{sup +} implants for doping, maximization of implant-isolated regions, and Ohmic contact sintering. We have compared two methods for protection against surface dissociation of GaN, AlN, InN, In{sub x}Ga{sub 1{minus}x}N, and In{sub x}Al{sub 1{minus}x}N during rapid thermal processing in N{sub 2} ambients. In the first method, AlN or InN powder is placed in the reservoirs of a SiC-coated graphite susceptor and provides a N{sub 2} overpressure for the nitride samples within the susceptor. In the second method, the nitrides are placed face down on other III{endash}V substrates during annealing. In both techniques N loss from the nitride surface is found to occur at {ge}1050{degree}C for GaN and {ge}1100{degree}C for AlN and {ge}InN, as measured by Auger electron spectroscopy. Real surface roughening is generally significant only for the In-containing materials, with GaN and AlN retaining smooth morphologies even up to 1150{degree}C unless H{sub 2} is present in the annealing ambient. When InN powder is used in the susceptor, there is In droplet condensation on the surfaces of all samples above {approximately}750{degree}C leading to higher root-mean-square surface roughness measured by atomic force microscopy. The N{sub 2}-deficient surfaces of the binary nitrides become strongly n type, while those of ternaries become less conducting. At temperature of 850{endash}900{degree}C, the In droplets on thermally degraded ternaries also begin to evaporate, leading to an apparent improvement in morphology. The presence of H{sub 2} or O{sub 2} in the annealing ambient lowers the dissociation temperature of each of the nitrides by 100{endash}200{degree}C, due to an enhancement in N{sub 2} removal. {copyright} {ital 1997 American Vacuum Society.}

  17. Compositional analysis of dilute nitride doped indium antimonide bulk crystal by VDS technique

    NASA Astrophysics Data System (ADS)

    Deshpande, Manisha; Maske, Dilip; Choudhari, Rashmi; Arora, Brij Mohan; Gadkari, Dattatray

    2016-05-01

    Dilute nitrides are suitable materials for fabrication of devices in detection of long wavelength infrared region. Dilute nitride doped Indium antimonide bulk crystals were grown using vertical directional solidification technique. The compositional characteristics of the crystals were carried out using EDS. The analysis was simulated and compared with observations using DTSA II software for accuracy. The ingots have uniform composition of Indium and Antimony. The actual nitrogen composition measured using EDS was 0.136% for doped nitrogen composition 0.1% except near conical end where it was 0.1%. The study of bonding between nitrogen, Indium and antimony was carried out using SIMS. The analysis shows strong presence of In-N bonding along with In-Sb bonds which indicates nitrogen has replaced antimony atoms in crystal lattice.

  18. Ultralow nonalloyed Ohmic contact resistance to self aligned N-polar GaN high electron mobility transistors by In(Ga)N regrowth

    SciTech Connect

    Dasgupta, Sansaptak; Nidhi,; Brown, David F.; Wu, Feng; Keller, Stacia; Speck, James S.; Mishra, Umesh K.

    2010-04-05

    Ultralow Ohmic contact resistance and a self-aligned device structure are necessary to reduce the effect of parasitic elements and obtain higher f{sub t} and f{sub max} in high electron mobility transistors (HEMTs). N-polar (0001) GaN HEMTs, offer a natural advantage over Ga-polar HEMTs, in terms of contact resistance since the contact is not made through a high band gap material [Al(Ga)N]. In this work, we extend the advantage by making use of polarization induced three-dimensional electron-gas through regrowth of graded InGaN and thin InN cap in the contact regions by plasma (molecular beam epitaxy), to obtain an ultralow Ohmic contact resistance of 27 OMEGA mum to a GaN 2DEG.

  19. Idealised Simulations of Daytime Pollution Transport in a Steep Valley and its Sensitivity to Thermal Stratification and Surface Albedo

    NASA Astrophysics Data System (ADS)

    Lehner, M.; Gohm, A.

    2010-02-01

    Numerical simulations of tracer transport in an idealised, east-west aligned valley are performed with the Regional Atmospheric Modeling System (RAMS), both two-dimensional and three-dimensional. The results are qualitatively consistent with wintertime observations in the Austrian Inn Valley. The simulations show an asymmetry in wind circulation and tracer distribution between the valley sidewalls according to the orientation of the slope with respect to the sun. Two-dimensional sensitivity experiments are run to investigate the influence of vertical inhomogeneities in thermal stratification and vegetation coverage on the slope-wind circulation and therewith the tracer transport. It is shown that a transition to a layer of higher stability or to a region with higher surface albedo causes a reduction of the mass flux in the upslope-wind layer and due to mass continuity a quasi-horizontal transport out of the slope-wind layer.

  20. Overview of Probabilistic Methods for SAE G-11 Meeting for Reliability and Uncertainty Quantification for DoD TACOM Initiative with SAE G-11 Division

    NASA Technical Reports Server (NTRS)

    Singhal, Surendra N.

    2003-01-01

    The SAE G-11 RMSL Division and Probabilistic Methods Committee meeting during October 6-8 at the Best Western Sterling Inn, Sterling Heights (Detroit), Michigan is co-sponsored by US Army Tank-automotive & Armaments Command (TACOM). The meeting will provide an industry/government/academia forum to review RMSL technology; reliability and probabilistic technology; reliability-based design methods; software reliability; and maintainability standards. With over 100 members including members with national/international standing, the mission of the G-11's Probabilistic Methods Committee is to "enable/facilitate rapid deployment of probabilistic technology to enhance the competitiveness of our industries by better, faster, greener, smarter, affordable and reliable product development."

  1. Correct Implementation of Polarization Constants in Wurtzite Materials and Impact on III-Nitrides

    NASA Astrophysics Data System (ADS)

    Dreyer, Cyrus E.; Janotti, Anderson; Van de Walle, Chris G.; Vanderbilt, David

    2016-04-01

    Accurate values for polarization discontinuities between pyroelectric materials are critical for understanding and designing the electronic properties of heterostructures. For wurtzite materials, the zincblende structure has been used in the literature as a reference to determine the effective spontaneous polarization constants. We show that, because the zincblende structure has a nonzero formal polarization, this method results in a spurious contribution to the spontaneous polarization differences between materials. In addition, we address the correct choice of "improper" versus "proper" piezoelectric constants. For the technologically important III-nitride materials GaN, AlN, and InN, we determine polarization discontinuities using a consistent reference based on the layered hexagonal structure and the correct choice of piezoelectric constants, and discuss the results in light of available experimental data.

  2. Effects of hole localization on limiting p-type conductivity in oxide and nitride semiconductors

    SciTech Connect

    Lyons, J. L.; Janotti, A.; Van de Walle, C. G.

    2014-01-07

    We examine how hole localization limits the effectiveness of substitutional acceptors in oxide and nitride semiconductors and explain why p-type doping of these materials has proven so difficult. Using hybrid density functional calculations, we find that anion-site substitutional impurities in AlN, GaN, InN, and ZnO lead to atomic-like states that localize on the impurity atom itself. Substitution with cation-site impurities, on the other hand, triggers the formation of polarons that become trapped on nearest-neighbor anions, generally leading to large ionization energies for these acceptors. Unlike shallow effective-mass acceptors, these two types of deep acceptors couple strongly with the lattice, significantly affecting the optical properties and severely limiting prospects for achieving p-type conductivity in these wide-band-gap materials.

  3. Dilute antimonide nitride for long wavelength infrared photodetection

    SciTech Connect

    Chen, X. Z.; Jin, Y. J.; Zhang, D. H.

    2014-05-15

    InSb{sub 1−x}N{sub x} materials were fabricated by direct nitrogen implantation into InSb wafer and they are characterized by X-ray diffraction, Hall measurement, X-ray photoelectron spectroscopy. In-N bonds are clearly demonstrated and other forms of nitrogen, such as antisites (N{sub In}), interstitial N{sub 2}, also exist in the grown films. The ratio to the total nitrogen bonds formed in the materials varies with preparation conditions. The optical bandgap data confirmed bandgap narrowing due to the incorporation of nitrogen. Photoconductive and photovoltaic photodetectors are fabricated and the cut-off frequencies of up to 11.5 μm are demonstrated.

  4. Assessment of tritium in the Savannah River Site environment

    SciTech Connect

    Carlton, W.H.; Murphy, C.E. Jr.; Bauer, L.R.

    1993-10-01

    This report is the first revision to a series of reports on radionuclides inn the SRS environment. Tritium was chosen as the first radionuclide in the series because the calculations used to assess the dose to the offsite population from SRS releases indicate that the dose due to tritium, through of small consequence, is one of the most important the radionuclides. This was recognized early in the site operation, and extensive measurements of tritium in the atmosphere, surface water, and ground water exist due to the effort of the Environmental Monitoring Section. In addition, research into the transport and fate of tritium in the environment has been supported at the SRS by both the local Department of Energy (DOE) Office and DOE`s Office of Health and Environmental Research.

  5. Deformation in the continental lithosphere

    NASA Astrophysics Data System (ADS)

    The Physical Properties of Earth Materials Committee, a technical committee of AGU's Tectonophysics Section, is organizing a dinner/colloquium as part of the Fall Meeting in San Francisco, Calif. This event will be held Monday, December 3rd, in the Gold Rush Room of the Holiday Inn Golden Gateway Hotel at 1500 Van Ness St. There will be a no-host bar from 6:30 to 7:30 P.M., followed by dinner from 7:30 to 8:30 P.M. Paul Tapponnier will deliver the after-dinner talk, “Large-Scale Deformation Mechanisms in the Continental Lithosphere: Where Do We Stand?” It will start at 8:30 P.M. and a business meeting will follow at 9:30 P.M.

  6. Thirty-five years after Stonewall: an exploratory study of satisfaction with police among gay, lesbian, and bisexual persons at the 34th Annual Atlanta Pride Festival.

    PubMed

    Gillespie, Wayne

    2008-01-01

    The gay rights movement began in the summer of 1969 when gay men rioted against police for raiding a bar known as the Stonewall Inn. In the succeeding 35 years, very little research has explored the relationship between police organizations and gay, lesbian, bisexual, and transgendered (GLBT) communities. The purpose of this study is to describe the attitudes that GLBT persons currently hold toward police. Subjects were sampled from the 34th Annual Atlanta Pride Festival and asked to complete a self-administered questionnaire. Of the 179 GLBT participants, the vast majority reported high satisfaction with community policing practices at this event. Moreover, age, household income, victimization, security presence, and identification with gay-themed media significantly predicted attitudes toward police.

  7. Nearly lattice-matched n, i, and p layers for InGaN p-i-n photodiodes in the 365-500 nm spectral range

    NASA Astrophysics Data System (ADS)

    Berkman, E. A.; El-Masry, N. A.; Emara, A.; Bedair, S. M.

    2008-03-01

    We report on nearly lattice-matched grown InGaN based p-i-n photodiodes detecting in the 365-500nm range with tunable peak responsivity tailored by the i-layer properties. The growth of lattice matched i- and n-InGaN layer leads to improvement in the device performance. This approach produced photodiodes with zero-bias responsivities up to 0.037A /W at 426nm, corresponding to 15.5% internal quantum efficiency. The peak responsivity wavelength ranged between 416 and 466nm, the longest reported for III-N photodiodes. The effects of InN content and i-layer thickness on photodiode properties and performance are discussed.

  8. InAlN/InGaN/GaN double heterostructure with improved carrier confinement and high-temperature transport performance grown by metal-organic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; Shuai Xue, Jun; Zhang, Jin Cheng; Zhou, Xiao Wei; Chao Zhang, Ya; Hao, Yue

    2015-07-01

    A nearly lattice-matched InAlN/InGaN/GaN double heterostructure (DH) and traditional InAlN/GaN single heterostructure (SH) were grown by metal-organic chemical vapor deposition. The InN mole fraction of InGaN channel was deduced by XRD and photoluminescence. The electrical properties were characterized by capacitance-voltage and temperature-dependent Hall measurements. Both results revealed that the InAlN/InGaN/GaN DH possessed superior carrier confinement over traditional InAlN/GaN SH owing to the back barrier formed at the InGaN/GaN interface, which prevents the spilling over of carriers and thus remarkably improves the transport performance at high temperature. Furthermore, a thin InGaN layer was preferable for carrier channel applications to a thick one.

  9. Compositional variation of nearly lattice-matched InAlGaN alloys for high electron mobility transistors

    NASA Astrophysics Data System (ADS)

    Lim, T.; Aidam, R.; Kirste, L.; Waltereit, P.; Quay, R.; Müller, S.; Ambacher, O.

    2010-06-01

    Quaternary InAlGaN semiconductors with AlN mole fractions between 40% and 81% and respective InN contents of 7% and 19% including InAlN as a ternary border case have been grown by plasma-assisted molecular beam epitaxy. The electron mobility in InAlGaN-based heterostructures increases with Ga concentration in the barrier up to 1460 cm2/V s at a sheet electron density of 1.9×1013 cm-2. An advanced spacer comprising an AlN/GaN/AlN triple-layer sequence is inserted between the GaN-buffer and the InAlGaN-barrier. Transistors with thin quaternary barrier show a large current density of 2.3 A/mm and an excellent transconductance of 675 mS/mm.

  10. The CDF-II silicon tracking system

    SciTech Connect

    Timothy K. Nelson

    2001-12-07

    The CDF silicon tracking system for Run II of the Fermilab Tevatron consists of eight layers arranged in cylinders spanning radii from 1.35cm to 28cm, and lengths from 90cm to nearly two meters for a total of six square meters of silicon and 722,000 readout channels. With an innermost layer (Layer 00) utilizing radiation tolerant p{sup +}-in-n silicon and low-mass readout cables between the sensors and readout electronics, double-sided vertexing layers (SVXII) designed for use with a deadtimeless secondary-vertex trigger, and outermost layers (ISL) utilizing mass-producible modules attached to a carbon fiber spaceframe, this system is a starting point for the next generation of silicon trackers for the LHC and Tevatron.

  11. Determination of InN/Diamond Heterojunction Band Offset by X-ray Photoelectron Spectroscopy

    PubMed Central

    2011-01-01

    Diamond is not only a free standing highly transparent window but also a promising carrier confinement layer for InN based devices, yet little is known of the band offsets in InN/diamond system. X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band offset (VBO) of InN/diamond heterostructure. The value of VBO was determined to be 0.39 ± 0.08 eV and a type-I heterojunction with a conduction band offset (CBO) of 4.42 ± 0.08 eV was obtained. The accurate determination of VBO and CBO is important for the application of III-N alloys based electronic devices. PMID:27502672

  12. GaInN-based tunnel junctions with graded layers

    NASA Astrophysics Data System (ADS)

    Takasuka, Daiki; Akatsuka, Yasuto; Ino, Masataka; Koide, Norikatsu; Takeuchi, Tetsuya; Iwaya, Motoaki; Kamiyama, Satoshi; Akasaki, Isamu

    2016-08-01

    We demonstrated low-resistivity GaInN-based tunnel junctions using graded GaInN layers. A systematic investigation of the samples grown by metalorganic vapor phase epitaxy revealed that a tunnel junction consisting of a 4 nm both-sides graded GaInN layer (Mg: 1 × 1020 cm-3) and a 2 nm GaN layer (Si: 7 × 1020 cm-3) showed the lowest specific series resistance of 2.3 × 10-4 Ω cm2 at 3 kA/cm2 in our experiment. The InN mole fraction in the 4 nm both-sides graded GaInN layer was changed from 0 through 0.4 to 0. The obtained resistance is comparable to those of standard p-contacts with Ni/Au and MBE-grown tunnel junctions.

  13. Strong enhancement of piezoelectric constants in ScxAl1-xN: First-principles calculations

    NASA Astrophysics Data System (ADS)

    Momida, Hiroyoshi; Teshigahara, Akihiko; Oguchi, Tamio

    2016-06-01

    We theoretically investigate the piezoelectricity of ScxAl1-xN in the entire range of x by first-principles calculations. We find that the piezoelectric constants of wurtzite-type ScxAl1-xN significantly enhance as x increases from 0 to 0.75. However, the energy stability analyses between structure phases show that the cubic-type phases become more stable than the wurtzite-type phases at x of approximately 0.5 and higher, interfering with the ability of wurtzite-type ScxAl1-xN to realize the maximum piezoelectricity. Moreover, our study on element combination dependences on piezoelectricity in A0.5B0.5N (A = Sc, Y, La and B = Al, Ga, In) indicates that Sc, Y, and La have the strongest effect on the enhancement of piezoelectric constants in AlN, GaN, and InN, respectively.

  14. Electron and hole accumulations at GaN/AlInN/GaN interfaces and conductive n-type AlInN/GaN distributed Bragg reflectors

    NASA Astrophysics Data System (ADS)

    Yoshida, Shotaro; Ikeyama, Kazuki; Yasuda, Toshiki; Furuta, Takashi; Takeuchi, Tetsuya; Iwaya, Motoaki; Kamiyama, Satoshi; Akasaki, Isamu

    2016-05-01

    We investigated electron and hole accumulations at GaN/AlInN/GaN interfaces by Hall effect measurement. The InN mole fraction and temperature dependences on the sheet carrier densities at the interfaces reveal that electrons and holes were induced by large positive and negative polarization charges to satisfy the charge neutrality conditions, respectively. On the basis of the above results, we then designed and demonstrated a low-resistity 10-pair Si-doped n-type AlInN/GaN distributed Bragg reflector (DBR) by using high Si doped and graded layers at the GaN/AlInN interfaces. The low-resistity n-type AlInN/GaN DBR will reduce the resistance and the internal loss in blue vertical-cavity surface emitting lasers.

  15. The assembly, collapse and restoration of food webs

    USGS Publications Warehouse

    Dobson, Andy; Allesina, Stefano; Lafferty, Kevin; Pascual, Mercedes

    2009-01-01

    Darwin chose the metaphor of a 'tangled bank' to conclude the 'Origin of species'. Two centuries after Darwin's birth, we are still untangling the complex ecological networks he has pondered. In particular, studies of food webs provide important insights into how natural ecosystems function (Pascual & Dunne 2005). Although the nonlinear interactions between many species creates challenges of scale, resolution of data and significant computational constraints, the last 10 years have seen significant advances built on the earlier classic studies of Cohen, May, Pimm, Polis, Lawton and Yodzis (May 1974; Cohen 1978; Pimm 1982; Briand & Cohen 1984, 1987; Yodzis 1989; Cohen et al. 1990; Pimm et al. 1991; Yodzis & Innes 1992; Yodzis 1998). These gains stem from advances in computing power and the collation of more comprehensive data from a broader array of empirical food webs.

  16. Electronic and Optical Properties of Energetic Particle-IrradiatedIn-rich InGaN

    SciTech Connect

    Li, S.X.; Yu, K.M.; Jones, R.E.; Wu, J.; Walukiewicz, W.; AgerIII, J.W.; Shan, W.; Haller, E.E.; Lu, Hai; Schaff, William J.; Kemp, W.

    2005-04-13

    We have carried out a systematic study of the effects of irradiation on the electronic and optical properties of InGaN alloys over the entire composition range. High energy electrons, protons, and {sup 4}He{sup +} were used to produce displacement damage doses (D{sub d}) spanning over five orders of magnitude. The free electron concentrations in InN and In-rich InGaN increase with D{sub d} and finally saturate after a sufficiently high D{sub d}. The saturation of carrier density is attributed to the formation of native donors and the Fermi level pinning at the Fermi Stabilization Energy (E{sub FS}), as predicted by the amphoteric native defect model. Electrochemical capacitance-voltage (ECV) measurements reveal a surface electron accumulation whose concentration is determined by pinning at E{sub FS}.

  17. Tempo of gulf activity brightens outlook

    SciTech Connect

    Hagar, R. )

    1989-12-01

    Operators, mainly on the basis of oil and natural gas price expectations, plan to steadily boost their exploration and development work in the Gulf of Mexico. The increase in activity, however, isn't yet reflected in the gulf's rig count. An active rig tally shows the October average to be the second lowest for all the Octobers in the 1980s. Only during October 1986 were there fewer rigs working in the gulf during that month this decade. On an annual basis, however, the monthly active rig count in 1989 is higher than in 1986 and 1987, but short of 1988's average and less than one half the level recorded inn the peak year of 1981. The author discusses signs that activity is rebounding.

  18. Current trends in food web theory report on a food web workshop. Environmental Sciences Division Publication No. 2224

    SciTech Connect

    DeAngelis, D.L.; Post, W.M.; Sugihara, G.

    1983-10-01

    This report summarizes the Food Web Workshop, held at Fontana Village Inn, October 25-27, 1982. The objective of the workshop was to review and assess recent progress in the understanding of ecological food webs. The workshop focused on three main areas: (1) what has been observed of food web patterns (food chain length, intervality, predator-prey ratios, etc.), (2) processes involved in food chains (energy flow and nutrient cycles), and (3) the dynamic behavior of food webs (Lyapunov stability, resilience, etc.). The introduction reviews some of the important contributions to food web theory during the past decade. The synopses of the presentations by invited speakers address many of the specific themes in current thought on food webs.

  19. Numerical Modeling of Supra-Arcade Downflows

    NASA Astrophysics Data System (ADS)

    Huang, Y. M.; Bhattacharjee, A.; Guo, L.; Innes, D.

    2015-12-01

    Abstract Supra-arcade downflows (SADs) are elongated features usually observed above post-eruption flare arcades, with low emission, low density, and high temperature. Although SADs have been observed and studied extensively, their physical interpretation and mechanism remain not well understood and controversial. In our recent numerical and observational studies, we suggest that SADs may be due to Rayleigh-Taylor type instabilities occurring at the front of reconnection outflow jets as they encounter the underlying arcades (Innes et al. Astrophys. J. 796, 27; Guo et al. Astrophys. J. Lett., 796, L29). In this work, we further improve our three-dimensional magnetohydrodynamic model of SADs by incorporating viscous and resistive heating, anisotropic heat conduction, as well as line-tied lower boundary conditions. Synthetic SDO AIA emission measure profiles are calculated from simulation data and compared with observations.

  20. Evaluation of the indium gallium nitride/silicon broken-gap heterojunction and its potential application for solar cells

    NASA Astrophysics Data System (ADS)

    Yao, Yuan

    InGaN (especially In-rich alloy) has been actively studied for decades since the band gap of InN was revised downward from ˜2.0 eV to 0.64 eV. The potential applications for alloys of In-rich InGaN hence became apparent. Despite the promising potential, photovoltaic devices based on InGaN have struggled due to a number of key limitations and fundamental physical problems. Firstly, due to the deep excursion of the InN conduction band at the gamma point, defects in InN are almost universally n-type leading to unintentional degenerate doping. This also leads to the problem of electron accumulation at all surfaces and interfaces of InN. Secondly, p-type doping is problematic, partially due to the degenerate doping effect of defects, but it has also been observed that Mg-doping, while leading to a p-type layer, dramatically reduces the quantum efficiency. This thesis explores an alternative approach using n-type InGaN to form a heterojunction with a p-type Si substrate. One potential benefit to using p-type Si as a substrate material for InGaN is that the valence band of Si possibly lines up with the conduction band of InGaN for a specific mole fraction of indium. Such a band alignment is known as a broken gap heterojunction, an example of which is the interface between InAs and AlxGa 1--xSb. The benefits of this broken-gap junction include a low series resistance, high electron mobility, and mobility only weakly dependent on temperature. These properties enable new approach to photovoltaic devices. The InGaN/Si heterojunctions were fabricated by plasma-assisted molecular beam epitaxy under stoichiometric flux conditions. An ultra-thin SiN interface layer was introduced, by Si nitridation process, to passivate the substrate surface and prevent In-Si and Ga-Si eutectic problems. InGaN films with a variety of indium mole fractions were grown by calibrating the In/Ga flux ratio during the deposition. The chemical composition of as-grown films was characterized by x

  1. Temperature Dependence of Surface Acoustic Wave Propagation Velocity in InxGa1-xN Films Obtained by High-Resolution Brillouin Spectroscopy: Determination of Temperature Coefficient of Frequency

    NASA Astrophysics Data System (ADS)

    Riobóo, Rafael J. Jiménez; Prieto, Carlos; Cuscó, Ramón; Artús, Lluís; Boney, Chris; Bensaoula, Abdelhak; Yamaguchi, Tomohiro; Nanishi, Yasushi

    2013-05-01

    Temperature-dependent surface acoustic wave (SAW) propagation velocity and temperature coefficient of frequency (TCF) have been determined for the first time in InxGa1-xN alloys by means of high-resolution Brillouin spectroscopy (HRBS). HRBS offers an alternative way of determining TCF. The obtained TCF values present a non-linear behavior with the In concentration. TCF of pure InN (-13.75 ppm/K) is similar to those of AlN and GaN (-19 and -17.7 ppm/K, respectively). InxGa1-xN samples exhibit frequency values that are very stable against temperature changes, which makes InxGa1-xN a good candidate for current SAW-based technological applications.

  2. Mercury Sample Return using Solar Sails

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E.; Young, Roy M.; Adams, Charles L.

    2006-01-01

    A conventional Mercury sample return mission requires significant launch mass due to the large deltav required for the outbound and return trips, and the large mass of a planetary lander and ascent vehicle. Solar sailing can be used to reduce lander mass allocation by delivering the lander to a low, thermally safe orbit close to the terminator. Propellant mass is not an issue for solar sails so a sample can be returned relatively easily, without resorting to lengthy, multiple gravity assists. The initial Mercury sample return studies reported here were conducted under ESA contract ESTEC/16534/02/NL/NR, PI Colin McInnes, Technical Officer Peter Falkner. Updated solar sail capabilities were developed under the Ground System Demonstration program, funded by the NASA's In-Space Propulsion Technology (ISPT) Program.

  3. Proliferation Risks of Magneetic Fusion Energy: Clandestine Production, Covert Production and Breakout

    SciTech Connect

    A. Glaser and R.J. Goldston

    2012-03-13

    Nuclear proliferation risks from magnetic fusion energy associated with access to weapon-usable materials can be divided into three main categories: (1) clandestine production of weapon-usable material in an undeclared facility, (2) covert production of such material inn a declared facility, and (3) use of a declared facility in a breakout scenario, in which a state begins production of fissile material without concealing the effort. In this paper we address each of these categories of risks from fusion. For each case, we find that the proliferation risk from fusion systems can be much lower than the equivalent risk from fission systems, if the fusion system is designed to accommodate appropriate safeguards.

  4. Reginald Crundall Punnett: First Arthur Balfour Professor of Genetics, Cambridge, 1912

    PubMed Central

    Edwards, A. W. F.

    2012-01-01

    R. C. Punnett, the codiscoverer of linkage with W. Bateson in 1904, had the good fortune to be invited to be the first Arthur Balfour Professor of Genetics at Cambridge University, United Kingdom, in 1912 when Bateson, for whom it had been intended, declined to leave his new appointment as first Director of the John Innes Horticultural Institute. We here celebrate the centenary of the first professorship dedicated to genetics, outlining Punnett’s career and his scientific contributions, with special reference to the discovery of “partial coupling” in the sweet pea (later “linkage”) and to the diagram known as Punnett’s square. His seeming reluctance as coauthor with Bateson to promote the reduplication hypothesis to explain the statistical evidence for linkage is stressed, as is his relationship with his successor as Arthur Balfour Professor, R. A. Fisher. The background to the establishment of the Professorship is also described. PMID:22964834

  5. Data-mining for sulfur and fluorine: an evaluation of pharmaceuticals to reveal opportunities for drug design and discovery.

    PubMed

    Ilardi, Elizabeth A; Vitaku, Edon; Njardarson, Jon T

    2014-04-10

    Among carbon, hydrogen, oxygen, and nitrogen, sulfur and fluorine are both leading constituents of the pharmaceuticals that comprise our medicinal history. In efforts to stimulate the minds of both the general public and expert scientist, statistics were collected from the trends associated with therapeutics spanning 12 disease categories (a total of 1969 drugs) from our new graphical montage compilation: disease focused pharmaceuticals posters. Each poster is a vibrant display of a collection of pharmaceuticals (including structural image, Food and Drug Administration (FDA) approval date, international nonproprietary name (INN), initial market name, and a color-coded subclass of function) organized chronologically and classified according to an association with a particular clinical indication. Specifically, the evolution and structural diversity of sulfur and the popular integration of fluorine into drugs introduced over the past 50 years are evaluated. The presented qualitative conclusions in this article aim to promote innovative insights into drug development. PMID:24102067

  6. Human laryngitis caused by Clinostomum complanatum.

    PubMed

    Hara, Hirotaka; Miyauchi, Yuji; Tahara, Shinsaku; Yamashita, Hiroshi

    2014-02-01

    A 64-year-old Japanese man visited our outpatient department complaining of an irritable sensation in the throat, occurring two days after eating raw freshwater fish (carp sashimi) at a Japanese-style inn. During laryngeal endoscopy, a slow-moving worm (fluke) was found attached to the surface of the right aryepiglottic fold. After inhalation of 4% lidocaine, the fluke was removed using endoscopic forceps. Patient's throat symptoms immediately improved. The worm was microscopically identified as Clinostomum complanatum. C. complanatum is a digenetic trematode that usually infects fish-eating water birds. Clinostomum infections in humans are rare, and only 21 cases have been described in Japan and Korea. C. complanatum infection is known to occur after eating raw freshwater fish, which is a secondary intermediate host. In humans, the metacercariae are released into the stomach and migrate through the esophagus before lodging in the throat. Primary therapy involves endoscopic removal of the worm.

  7. Hot electrons in group-III nitrides at moderate electric fields

    NASA Astrophysics Data System (ADS)

    Barry, E. A.; Kim, K. W.; Kochelap, V. A.

    2002-04-01

    By the use of the Monte Carlo method, we studied the distribution function and the basic characteristics of hot electrons in InN, GaN, and AlN under moderate electric fields. We found that in relatively low fields (of the order of kV/cm) the optical phonon emission dominates in the electron kinetics. This strongly inelastic process gives rise to a spindle-shaped distribution function and an extended portion of a quasisaturation of the current-voltage (I-V) characteristics (the streaming-like regime). Formation of this regime is induced by a suppression of the electron spreading over the momenta perpendicular to the electric field. We prove that this is a universal character of the hot electron behavior for all three nitrides. The effects can be detected by the measurement of the I-V characteristics, or the thermopower of hot electrons in the transverse direction.

  8. Electron scattering by native defects in III-V nitrides and their alloys

    SciTech Connect

    Hsu, L.; Walukiewicz, W.

    1996-03-01

    We have calculated the electron mobilities in GaN and InN taking into consideration scattering by short range potentials, in addition to all standard scattering mechanisms. These potentials are produced by the native defects which are responsible for the high electron concentrations in nominally undoped nitrides. Comparison of the calculated mobilities with experimental data shows that scattering by short range potentials is the dominant mechanism limiting the electron mobilities in unintentionally doped nitrides with large electron concentrations. In the case of Al{sub x}Ga{sub 1-x}N alloys, the reduction in the electron concentration due to the upward shift of the conduction band relative to the native defect level can account for the experimentally measured mobilities. Resonant scattering is shown to be important when the defect and Fermi levels are close in energy.

  9. Plasma etching of the Group-III nitrides

    SciTech Connect

    Shul, R.; Pearton, S.J.; Abernathy, C.R.

    1996-01-01

    In reactive ion etching (RIE) of GaN, the ion bombardment can damage the material, so it is necessary to develop plasma etch processes. This paper reports etching of GaN in an ECR (electron cyclotron resonance) etch system using both the ECR/RIE mode and the RIE-only mode. Group III (Ga, In, Al) nitride ECR etching is reviewed as a function of plasma chemistry, power, temperature, and pressure; as the ECR microwave power increased, the ion density and etch rates increased, with the etch rate increasing the most for InN. GaN etch rates > 6500 {angstrom}/min have been observed in the ECR/RIE mode. 2 figs, 6 refs.

  10. Human granulocytic anaplasmosis in Austria: epidemiological, clinical, and laboratory findings in five consecutive patients from Tyrol, Austria.

    PubMed

    Walder, Gernot; Fuchs, Dietmar; Sarcletti, Mario; Berek, Klaus; Falkensammer, Barbara; Huber, Klaus; Petrovec, Miro; Dierich, Manfred P; Würzner, Reinhard

    2006-05-01

    We report five consecutive cases of Anaplasma (A.) phagocytophilum infection (the causative agent of human granulocytic anaplasmosis (HGA)) from western Austria. All infections were acquired between June and August in 2003 and 2004 in the Inn valley (Tyrol, Austria). Four patients required hospitalisation, one patient was treated as an outpatient. During the acute stage of illness, laboratory findings included thrombocytopenia (5/5), elevated C-reactive protein (5/5), elevated neopterin (5/5), elevated lactate dehydrogenase (4/5), and elevation of liver enzymes (4/5). Leukopenia (3/5) and elevated procalcitonin (2/5) were less frequently observed. All patients were treated with tetracyclines, which led to prompt improvement of the clinical conditions. Anti-platelet antibodies were observed in one of four patients, but remained unchanged after complete covalescence.

  11. Computational Chemistry Study on Crystal Growth of InGaN/GaN

    NASA Astrophysics Data System (ADS)

    Inaba, Yusaku; Onozu, Takayuki; Takami, Seiichi; Kubo, Momoji; Miyamoto, Akira; Imamura, Akira

    2001-04-01

    We carried out density functional theory (DFT) calculations and tight-binding quantum chemical molecular dynamics simulations to investigate the crystal growth of InGaN layers on a GaN(0001) surface under periodic boundary conditions. The periodic DFT calculations indicate that the formation of the uniform InGaN thin films is difficult, which leads to the segregation of In atoms in the InGaN thin films. The tight-binding quantum chemical molecular dynamics simulations suggest that the Ga polarity surface of the GaN(0001) is preferable for the construction of the smooth GaN thin films than the N polarity surface of the GaN(0001). Moreover, the formation of the smooth InN thin films was found to be difficult on the GaN(0001) surface.

  12. Reginald Crundall Punnett: first Arthur Balfour Professor of Genetics, Cambridge, 1912.

    PubMed

    Edwards, A W F

    2012-09-01

    R. C. Punnett, the codiscoverer of linkage with W. Bateson in 1904, had the good fortune to be invited to be the first Arthur Balfour Professor of Genetics at Cambridge University, United Kingdom, in 1912 when Bateson, for whom it had been intended, declined to leave his new appointment as first Director of the John Innes Horticultural Institute. We here celebrate the centenary of the first professorship dedicated to genetics, outlining Punnett's career and his scientific contributions, with special reference to the discovery of "partial coupling" in the sweet pea (later "linkage") and to the diagram known as Punnett's square. His seeming reluctance as coauthor with Bateson to promote the reduplication hypothesis to explain the statistical evidence for linkage is stressed, as is his relationship with his successor as Arthur Balfour Professor, R. A. Fisher. The background to the establishment of the Professorship is also described.

  13. Sixth Goddard Conference on Mass Storage Systems and Technologies Held in Cooperation with the Fifteenth IEEE Symposium on Mass Storage Systems

    NASA Technical Reports Server (NTRS)

    Kobler, Benjamin (Editor); Hariharan, P. C. (Editor)

    1998-01-01

    This document contains copies of those technical papers received in time for publication prior to the Sixth Goddard Conference on Mass Storage Systems and Technologies which is being held in cooperation with the Fifteenth IEEE Symposium on Mass Storage Systems at the University of Maryland-University College Inn and Conference Center March 23-26, 1998. As one of an ongoing series, this Conference continues to provide a forum for discussion of issues relevant to the management of large volumes of data. The Conference encourages all interested organizations to discuss long term mass storage requirements and experiences in fielding solutions. Emphasis is on current and future practical solutions addressing issues in data management, storage systems and media, data acquisition, long term retention of data, and data distribution. This year's discussion topics include architecture, tape optimization, new technology, performance, standards, site reports, vendor solutions. Tutorials will be available on shared file systems, file system backups, data mining, and the dynamics of obsolescence.

  14. The Visual Double Star Catalogs

    NASA Astrophysics Data System (ADS)

    Mason, Brian D.

    2015-08-01

    In visual double star work, production of the first comprehensive attempt to list all discovered pairs in his accessible sky was prepared by S.W. Burnham in 1906. A double star catalog for the southern hemisphere was prepared by R.T.A. Innes et al. in 1927 and the northern hemisphere catalog was updated by R.G. Aitken and E. Doolittle in 1932. Eventually, this led to Lick Observatory maintaining what became known as the Index Catalogue, an all-sky visual double star database.In 1964, under the aegis of Commission 26, the Lick double star database was transferred to the U.S. Naval Observatory where it was redesignated the Washington Double Star Catalog where it and it's ancillary catalogs, have been maintained for over half a century. The current statistics of the catalog and it's supplements are presented as are the enhancements currently under consideration.

  15. A critique of contact charge spectroscopy: A response

    NASA Astrophysics Data System (ADS)

    Fabish, T. J.; Duke, C. B.

    1988-08-01

    Comparison of the experimental parameters used in a recent set of contact charge exchange measurements by Lowell, Rose-Innes, and El-Kazzaz with those used earlier by Fabish, Saltsburg, and Hair reveals that the former correspond to the shallow injection (d˜1 nm) of small amounts of charge and the latter to the deeper (d˜2 μm) injection of larger amounts of charge. These differences suggest that the former results should be interpreted in terms of rapid charge sharing after injection (i.e., nonadditive transfer) whereas the latter should yield results characteristic of noncommunicating, nonequilibrium injected charges (i.e., additive transfer under certain conditions). They also reveal the importance of a careful analysis of the noise inherent in contact charge exchange measurements.

  16. Thirty-five years after Stonewall: an exploratory study of satisfaction with police among gay, lesbian, and bisexual persons at the 34th Annual Atlanta Pride Festival.

    PubMed

    Gillespie, Wayne

    2008-01-01

    The gay rights movement began in the summer of 1969 when gay men rioted against police for raiding a bar known as the Stonewall Inn. In the succeeding 35 years, very little research has explored the relationship between police organizations and gay, lesbian, bisexual, and transgendered (GLBT) communities. The purpose of this study is to describe the attitudes that GLBT persons currently hold toward police. Subjects were sampled from the 34th Annual Atlanta Pride Festival and asked to complete a self-administered questionnaire. Of the 179 GLBT participants, the vast majority reported high satisfaction with community policing practices at this event. Moreover, age, household income, victimization, security presence, and identification with gay-themed media significantly predicted attitudes toward police. PMID:19064482

  17. A Fusion Algorithm for GFP Image and Phase Contrast Image of Arabidopsis Cell Based on SFL-Contourlet Transform

    PubMed Central

    Feng, Peng; Wang, Jing; Wei, Biao; Mi, Deling

    2013-01-01

    A hybrid multiscale and multilevel image fusion algorithm for green fluorescent protein (GFP) image and phase contrast image of Arabidopsis cell is proposed in this paper. Combining intensity-hue-saturation (IHS) transform and sharp frequency localization Contourlet transform (SFL-CT), this algorithm uses different fusion strategies for different detailed subbands, which include neighborhood consistency measurement (NCM) that can adaptively find balance between color background and gray structure. Also two kinds of neighborhood classes based on empirical model are taken into consideration. Visual information fidelity (VIF) as an objective criterion is introduced to evaluate the fusion image. The experimental results of 117 groups of Arabidopsis cell image from John Innes Center show that the new algorithm cannot only make the details of original images well preserved but also improve the visibility of the fusion image, which shows the superiority of the novel method to traditional ones. PMID:23476716

  18. GaInN-based tunnel junctions with graded layers

    NASA Astrophysics Data System (ADS)

    Takasuka, Daiki; Akatsuka, Yasuto; Ino, Masataka; Koide, Norikatsu; Takeuchi, Tetsuya; Iwaya, Motoaki; Kamiyama, Satoshi; Akasaki, Isamu

    2016-08-01

    We demonstrated low-resistivity GaInN-based tunnel junctions using graded GaInN layers. A systematic investigation of the samples grown by metalorganic vapor phase epitaxy revealed that a tunnel junction consisting of a 4 nm both-sides graded GaInN layer (Mg: 1 × 1020 cm‑3) and a 2 nm GaN layer (Si: 7 × 1020 cm‑3) showed the lowest specific series resistance of 2.3 × 10‑4 Ω cm2 at 3 kA/cm2 in our experiment. The InN mole fraction in the 4 nm both-sides graded GaInN layer was changed from 0 through 0.4 to 0. The obtained resistance is comparable to those of standard p-contacts with Ni/Au and MBE-grown tunnel junctions.

  19. A comprehensive diagram to grow InAlN alloys by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Fernandez-Garrido, S.; Gacevic, Z.; Calleja, E.

    2008-11-10

    Indium incorporation and surface morphology of InAlN layers grown on (0001) GaN by plasma-assisted molecular beam epitaxy were investigated as a function of the impinging In flux and the substrate temperature in the 450-610 deg. C range. In incorporation was found to decrease with substrate temperature due to thermal decomposition of the growing layer, while for a given temperature it increased with the impinging In flux until stoichiometry was reached at the growth front. The InN losses during growth followed an Arrhenius behavior characterized by an activation energy of 2.0 eV. A growth diagram highly instrumental to identify optimum growth conditions was established.

  20. Stability of the ternary perovskites Sc3EN (E=B,Al,Ga,In) from first principles

    NASA Astrophysics Data System (ADS)

    Mikhaylushkin, A. S.; Höglund, C.; Birch, J.; Czigány, Zs.; Hultman, L.; Simak, S. I.; Alling, B.; Tasnádi, F.; Abrikosov, I. A.

    2009-04-01

    Mechanical and thermodynamic stability of the isoelectronic ternary inverse perovskites Sc3EN (E=B,Al,Ga,In) has been studied from first principles. We confirm stability of recently synthesized cubic phases Sc3AlN and Sc3InN , and predict the stability of cubic Sc3GaN and a triclinic phase aP20- Sc3BN . Substantial phonon softening in Sc3AlN and Sc3GaN is observed indicating a possibility that structural defects could form readily. In accord, our experiments show that magnetron sputter deposited films contain regions with high density of nonperiodic stacking faults along the ⟨111⟩ growth direction. We suggest that defect-free crystals may exhibit anomalies in the carrier properties, promising for electronic applications.

  1. Development of an Advanced Computational Model for OMCVD of Indium Nitride

    NASA Technical Reports Server (NTRS)

    Cardelino, Carlos A.; Moore, Craig E.; Cardelino, Beatriz H.; Zhou, Ning; Lowry, Sam; Krishnan, Anantha; Frazier, Donald O.; Bachmann, Klaus J.

    1999-01-01

    An advanced computational model is being developed to predict the formation of indium nitride (InN) film from the reaction of trimethylindium (In(CH3)3) with ammonia (NH3). The components are introduced into the reactor in the gas phase within a background of molecular nitrogen (N2). Organometallic chemical vapor deposition occurs on a heated sapphire surface. The model simulates heat and mass transport with gas and surface chemistry under steady state and pulsed conditions. The development and validation of an accurate model for the interactions between the diffusion of gas phase species and surface kinetics is essential to enable the regulation of the process in order to produce a low defect material. The validation of the model will be performed in concert with a NASA-North Carolina State University project.

  2. Human laryngitis caused by Clinostomum complanatum.

    PubMed

    Hara, Hirotaka; Miyauchi, Yuji; Tahara, Shinsaku; Yamashita, Hiroshi

    2014-02-01

    A 64-year-old Japanese man visited our outpatient department complaining of an irritable sensation in the throat, occurring two days after eating raw freshwater fish (carp sashimi) at a Japanese-style inn. During laryngeal endoscopy, a slow-moving worm (fluke) was found attached to the surface of the right aryepiglottic fold. After inhalation of 4% lidocaine, the fluke was removed using endoscopic forceps. Patient's throat symptoms immediately improved. The worm was microscopically identified as Clinostomum complanatum. C. complanatum is a digenetic trematode that usually infects fish-eating water birds. Clinostomum infections in humans are rare, and only 21 cases have been described in Japan and Korea. C. complanatum infection is known to occur after eating raw freshwater fish, which is a secondary intermediate host. In humans, the metacercariae are released into the stomach and migrate through the esophagus before lodging in the throat. Primary therapy involves endoscopic removal of the worm. PMID:25130004

  3. Solar hot water system installed at Day's Lodge, Atlanta, Georgia

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar energy hot water system installed in the Days Inns of America, Inc., Atlanta, Georgia is described. This system provides for 81 percent of the total hot water demand. There are two separate systems, each serving one building of the lodge (total of 65 suites). The entire system contains only potable city water. The 1024 square feet of Grumman Sunstream Model 332 liquid flat plate collectors and the outside piping drain whenever the collector plates approach freezing or when power is interrupted. Solar heated water from the two above ground cement lined steel tanks (1000 gallon tank) is drawn into the electric Domestic Hot Water (DHW) tanks as hot water is drawn. Electric resistance units in the DHW tanks top off the solar heated water, if needed, to reach thermostat setting.

  4. Optically- and Electrically-Stimulated Terahertz Radiation Emission from Indium Nitride

    NASA Astrophysics Data System (ADS)

    Wilke, Ingrid; Ding, Yujie J.; Shubina, Tatiana V.

    2012-06-01

    Indium nitride is a novel narrow band gap semiconductor. The material is a potential strong source of terahertz frequency electromagnetic radiation with applications in time-domain terahertz spectroscopy and imaging systems. This article reviews recent experimental research on terahertz emission from the binary compound semiconductor indium nitride excited by near-infrared laser beams or microseconds electrical pulses. Advantages of indium nitride as terahertz radiation source material are discussed. It is demonstrated that different mechanisms contribute to the emission of terahertz radiation from indium nitride. The emission of up to 2.4 μW of THz radiation power is observed when InN is excited with near-infrared femtosecond laser pulses at an average power of 1 W.

  5. Leakage Current Mechanism of InN-Based Metal-Insulator-Semiconductor Structures with Al2O3 as Dielectric Layers

    NASA Astrophysics Data System (ADS)

    Wang, X.; Zhang, G. Z.; Xu, Y.; Gan, X. W.; Chen, C.; Wang, Z.; Wang, Y.; Wang, J. L.; Wang, T.; Wu, H.; Liu, C.

    2016-01-01

    InN-based metal-insulator-semiconductor (MIS) structures were prepared with Al2O3 as the gate oxides. Surface morphologies of InN films are improved with increasing Mg doping concentrations. At high frequencies, the measured capacitance densities deviate from the real ones with turning frequencies inversely proportional to series resistances. An ultralow leakage current density of 1.35 × 10-9 A/cm2 at 1 V is obtained. Fowler-Nordheim tunneling is the main mechanism of the leakage current at high fields, while Schottky emission dominates at low fields. Capacitance densities shift with different biases, indicating that the InN-based MIS structures can serve as potential candidates for MIS field-effect transistors.

  6. Workshop on Program for Elimination of Requirements Marginal to Safety: Proceedings

    SciTech Connect

    Dey, M.; Arsenault, F.; Patterson, M.; Gaal, M.

    1993-09-01

    These are the proceedings of the Public Workshop on the US Nuclear Regulatory Commission`s Program for Elimination of Requirements Marginal to Safety. The workshop was held at the Holiday Inn, Bethesda, on April 27 and 28, 1993. The purpose of the workshop was to provide an opportunity for public and industry input to the program. The workshop addressed the institutionalization of the program to review regulations with the purpose of eliminating those that are marginal. The objective is to avoid the dilution of safety efforts. One session was devoted to discussion of the framework for a performance-based regulatory approach. In addition, panelists and attendees discussed scope, schedules and status of specific regulatory items: containment leakage testing requirements, fire protection requirements, requirements for environmental qualification of electrical equipment, requests for information under 10CFR50.54(f), requirements for combustible gas control systems, and quality assurance requirements.

  7. Immanuel Halton, the astronomer

    NASA Astrophysics Data System (ADS)

    Barber, P. M.

    1996-02-01

    Immanuel Halton was born in Cumberland, studied at Grays Inn, London during the later stages of the English Civil War and, during the Commonwealth, entered the service of Henry Howard, later 6th Duke of Norfolk. He pursued his mathematical and astronomical interests while auditor to the Duke of Norfolk. He met with John Flamsteed, encouraged the latter's interest in mathematics and astronomy and became his first patron, as well as contributing observations to Flamsteed's published works. Immanuel ended his days at Wingfield Manor, Derbyshire. A short biographical piece on Immanuel Halton appeared in the Journal in the early 1950s, consisting mostly of quotations from Flamsteed's 'Self Inspections' and Baily's 'Life of Flamsteed'. 1996 is the 350th anniversary of Flamsteed's birth, and it is hoped that this fuller account will flesh out the bones of his first patron.

  8. Dental, oral and facial limericks of yesterday and today.

    PubMed

    Christen, Arden G; Christen, Joan A

    2004-11-01

    The limerick is a popular form of light and poetic verse which was originally recited and sung in the local inns and taverns of Ireland and England. It may be anecdotal, nonsensical and/or ribald in nature. As a form of satire, it confronts society's "sacred cows" and/or foibles. During the mid-1800s, Edward Lear popularized this mode of expression in England. From there it spread throughout the entire world. By 1900, two branches of limerick writing were formed--the decent and the "smutty." In reviewing 7,000 traditional limericks, the authors have located about 50 significant dental, oral and/or facial limericks which are socially acceptable. In addition, we have produced 50 original poems of this nature. This article offers 33 traditional and new limerick "gems" for your reading pleasure.

  9. Physical properties and applications of In{sub x}Ga{sub 1−x}N nanowires

    SciTech Connect

    Segura-Ruiz, J.; Gómez-Gómez, M.; Garro, N.; Cantarero, A.; Martínez-Criado, G.; Denker, C.; Malindretos, J.; Rizzi, A.

    2014-05-15

    We have successfully grown In{sub x}Ga{sub 1−x}N nanowires by plasma-assisted molecular beam epitaxy on silicon substrates. The alloy composition and crystal quality have been analyzed by Raman scattering, photoluminescence spectroscopy and x-ray fluorescence nanoprobe techniques. In{sub x}Ga{sub 1−x}N is an one-mode alloy, where the different optical modes have an intermediate frequency of that of pure InN and GaN. The sample composition can be derived from the Raman data. On the other hand, by using the optical gap provided by the emission spectra, we conclude that the samples have a lower Ga content than that provided by the Raman analysis. X-ray fluorescence maps and photoluminescence measured in single nanowires help to explain this contradictory result.

  10. Infrared reflectivity spectra of gas-source molecular beam epitaxy grown dilute InN{sub x}As{sub 1-x}/InP (001)

    SciTech Connect

    Talwar, Devki N.; Yang, Tzuen-Rong; Hsiung Lin, Hao; Chuan Feng, Zhe

    2013-02-04

    Vibrational spectra of gas-source molecular beam epitaxy grown dilute InN{sub x}As{sub 1-x}/InP (001) alloys are obtained using a Fourier-transform infrared (IR) spectroscopy. A triply degenerate N{sub As} local vibrational mode of T{sub d}-symmetry is observed near 438 cm{sup -1} corresponding to the In-N bond energy. The analysis of composition dependent infrared reflectivity spectra in InNAs has predicted a two-phonon-mode behavior. In In(Ga)-rich GaInNAs alloys the observed splitting of the N{sub As} local mode into a doublet for the N{sub As}-Ga{sub 1}(In{sub 1})In{sub 3}(Ga{sub 3}) pair-defect of C{sub 3v}-symmetry is consistent with our simulated results based on a sophisticated Green's function theory.

  11. The assessment of the rice cultivars/lines resistance to blast disease in Mazandaran province, Iran.

    PubMed

    Amanzadeh, M; Okhovvat, S M; Moumeni, A; Javan-Nikkhah, M; Khosravi, V

    2004-01-01

    Blast, caused by Magnaporthe grisea, is one of the most important diseases in rice production regions of the world including Iran. To determine progress of rice blast disease on the selective cultivars and lines also to assay some components of partial resistance, a set of Iranian rice cultivars (Local and breeding) along with near-isogenic lines (NILs) and breeding lines from International Rice Research Institute (IRRI) were tested with some field races of the fungus in blast nursery and five of selective races in greenhouse. These experiments were conducted in a Randomized complete Block Design (RCBD) with three replications (except greenhouse experiment on the leaves). Traits in this study consisted of Infection Neck Number (INN), Neck Lesion Size (NLS), Infection Type (IT), percent Diseased Leaf Area (DLA) and Area Under Disease Progress Curve (AUDPC); also IT, Sporulation Lesion Number (SLN), Sporulating Region Diameter (SRD) and percent DLA were measured in leaf blast in greenhouse (one replication). The Iranian local cultivars and NILs i.e. Co-39 and C104-PKT located as susceptible group for AUDPC, IT, INN and NLS. Iranian breeding cultivars, breeding lines from IRRI and NILs (except Co-39 and C104-PKT) were resistant or indicated hypersensivity reaction (HR). Some cultivars (Fujiminori, Onda, and Hassan Saraii) were semi susceptible to leaf blast in nursery. The main point is correlation in 1% (a = 0.0001) between the traits in greenhouse and blast nursery. Neck node infection of Haraz cultivar in greenhouse experiment to IA-89 race is very important, because Haraz is a resistant cultivar to blast disease in Iran. PMID:15756856

  12. For nanowire growth, vapor-solid-solid (vapor-solid) mechanism is actually vapor-quasisolid-solid (vapor-quasiliquid-solid) mechanism.

    PubMed

    Noor Mohammad, S

    2009-12-14

    Vapor-phase mechanisms [e.g., vapor-liquid-solid (VLS), vapor-solid-solid, oxide-assisted growth, and the self-catalytic growth mechanisms] for the unidirectional nanowire (NW) growth are not yet well understood. For this understanding, growths of GaN and InN NWs in our laboratory, without and with the assistance of foreign element catalytic agents (FECAs), such as Au and In, were performed. GaN NW growth, in the presence of FECA identical withNi, was possible at temperatures below the Ni/Ga eutectic temperature. InN NWs were grown, in the presence of Au, and at temperatures in the vicinity of Au/In eutectic temperature. They were found to have Au at the NW tip, NW base, and NW sidewalls. Extensive investigation of the fundamentals underlying these anomalies has been carried out. The temperature dependence of the VLS mechanism has also been elucidated. A large number of available elemental and compound semiconductor NWs exhibiting similar characteristics have been considered for the investigation. Based on this investigation, a chemicophysical mechanism called the vapor-quasisolid-solid (VQS) (or vapor-semisolid-solid, or vapor-quasiliquid-solid, or vapor-semiliquid-solid) mechanism has been proposed. The cause of temperature dependence of the VLS growth under different growth conditions and growth environments, and the possible relationship between the VLS and the VQS mechanisms has been presented. To better describe the vapor-phase mechanisms, including the VQS mechanism, a unified definition of droplets has been proposed. A series of experimental evidences has been set forth to substantiate the validity of the proposed mechanism, and to justify the definition of the unified droplet model. They together appear to explain the fundamental basis of the NW growth by various mechanisms, including the VQS mechanisms. They also provide solutions of many known problems, conflicts, confusions, and controversies involving NW growth.

  13. For nanowire growth, vapor-solid-solid (vapor-solid) mechanism is actually vapor-quasisolid-solid (vapor-quasiliquid-solid) mechanism

    NASA Astrophysics Data System (ADS)

    Noor Mohammad, S.

    2009-12-01

    Vapor-phase mechanisms [e.g., vapor-liquid-solid (VLS), vapor-solid-solid, oxide-assisted growth, and the self-catalytic growth mechanisms] for the unidirectional nanowire (NW) growth are not yet well understood. For this understanding, growths of GaN and InN NWs in our laboratory, without and with the assistance of foreign element catalytic agents (FECAs), such as Au and In, were performed. GaN NW growth, in the presence of FECA≡Ni, was possible at temperatures below the Ni/Ga eutectic temperature. InN NWs were grown, in the presence of Au, and at temperatures in the vicinity of Au/In eutectic temperature. They were found to have Au at the NW tip, NW base, and NW sidewalls. Extensive investigation of the fundamentals underlying these anomalies has been carried out. The temperature dependence of the VLS mechanism has also been elucidated. A large number of available elemental and compound semiconductor NWs exhibiting similar characteristics have been considered for the investigation. Based on this investigation, a chemicophysical mechanism called the vapor-quasisolid-solid (VQS) (or vapor-semisolid-solid, or vapor-quasiliquid-solid, or vapor-semiliquid-solid) mechanism has been proposed. The cause of temperature dependence of the VLS growth under different growth conditions and growth environments, and the possible relationship between the VLS and the VQS mechanisms has been presented. To better describe the vapor-phase mechanisms, including the VQS mechanism, a unified definition of droplets has been proposed. A series of experimental evidences has been set forth to substantiate the validity of the proposed mechanism, and to justify the definition of the unified droplet model. They together appear to explain the fundamental basis of the NW growth by various mechanisms, including the VQS mechanisms. They also provide solutions of many known problems, conflicts, confusions, and controversies involving NW growth.

  14. Brittle deformation and hoodoo development in Bryce Canyon National Park

    NASA Astrophysics Data System (ADS)

    Haddon, E. K.; Webb, C.; McNitt, J.; Pollock, G. L.; Davis, L.; MacLean, J. S.

    2015-12-01

    Bryce Canyon is a dramatic southeast-facing escarpment located in the transition zone between the Basin and Range Province and the Colorado Plateau. Stream erosion of the Paleocene-to-Eocene Claron Formation generates vast amphitheaters and alcoves replete with elaborate fins, windowed walls, and hoodoos from Fairyland to Bryce Point. Geomorphic models of hoodoo development describe the influence of differential weathering and ice wedging along systematic vertical fractures formed during uplift of the Colorado Plateau. Conjugate shear fractures in the footwall of the south-vergent Rubys Inn thrust fault may provide additional preexisting weaknesses intersecting the predominantly flat-lying strata. During a summer 2015 GeoCorpsTM America internship, we investigated the contribution of joint sets to focused erosion of exposed fins and hoodoo development in Bryce Canyon National Park. Our field mapping documents the nature and spatial distribution of known fractures as well as a previously undocumented third generation characterized by steeply-dipping conjugates and zones of distributed deformation. Evidence for normal reactivation of contractional structures in the Sevier River drainage (MacLean, 2014) suggests that distributed deformation evolved during Basin and Range extension, possibly associated with the nearby Paunsaugunt fault. Cross-cutting relations among fracture sets suggest modest uplift and vertical jointing prior to collapse of the Marysvale volcanic complex (~22-20 Ma) and more recent Basin and Range extension. Spatial trends in fracture density illustrate a systematic increase in vertical, shear fractures, and reactivated zones to the north, proximal to thrust faulting. The increase in fracture density leads to accelerated weathering and erosion, with a corresponding increase in windows, hoodoos, and gentle slopes. While erosional windows commonly develop along vertical fractures intersecting relatively weak lithologies, approximately 60% of the 130

  15. High temperature surface degradation of III-V nitrides

    SciTech Connect

    Vartuli, C.B.; Pearton, S.J.; Abernathy, C.R.; MacKenzie, J.D.; Lambers, E.S.; Zolper, J.C.

    1996-05-01

    The surface stoichiometry, surface morphology and electrical conductivity of AlN, GaN, InN, InGaN and InAlN was examined at rapid thermal annealing temperatures up to 1,150 C. The sheet resistance of the AlN dropped steadily with annealing, but the surface showed signs of roughening only above 1,000 C. Auger Electronic Spectroscopy (AES) analysis showed little change in the surface stoichiometry even at 1,150 C. GaN root mean square (RMS) surface roughness showed an overall improvement with annealing, but the surface became pitted at 1,000 C, at which point the sheet resistance also dropped by several orders of magnitude, and AES confirmed a loss of N from the surface. The InN surface had roughened considerably even at 650 C, and scanning electron microscopy (SEM) showed significant degradation. In contrast to the binary nitrides the sheet resistance of InAlN was found to increase by {approximately} 10{sup 2} from the as grown value after annealing at 800 C and then remain constant up to 1,000 C, while that of InGaN increased rapidly above 700 C. The RMS roughness increased above 800 C and 700 C respectively for InAlN and InGaN samples. In droplets began to form on the surface at 900 C for InAlN and at 800 C for InGaN, and then evaporate at 1,000 C leaving pits. AES analysis showed a decrease in the N concentration in the top 500 {angstrom} of the sample for annealing {ge} 800 C in both materials.

  16. On the enantioselectivity of aziridination of styrene catalysed by copper triflate and copper-exchanged zeolite Y: consequences of the phase behaviour of enantiomeric mixtures of N-arene-sulfonyl-2-phenylaziridines.

    PubMed

    Jeffs, Laura; Arquier, Damien; Kariuki, Benson; Bethell, Donald; Page, Philip C Bulman; Hutchings, Graham J

    2011-02-21

    By synthesising S-2-phenyl-N-(4-nitrophenyl)aziridine from S-phenylglycinol, it has been demonstrated that the aziridination of styrene by [N-(4-nitrobenzenesulfonyl)imino]phenyliodinane (nosyliminophenyliodinane, PhINNs) in the presence of S,S-2,2'-isopropylidene-bis(4-phenyl-2-oxazoline), catalysed by copper(II) triflate in CH(3)CN solution or heterogeneously by CuHY, has predominantly an R-configuration. The enantioselectivity of the aziridination of styrene by [N-arenesulfonylimino]-phenyliodinanes catalysed by copper-exchanged zeolite Y (CuHY), in conjunction with a chiral bis-oxazoline ligand, has been re-examined. In the case of PhINNs, it is shown that the product mixture of enantiomeric aziridines, on treatment with hexane, gives rise to a solid phase of low enantiomeric excess (ee) and a solution phase of high ee. Separation of the solid phase and recrystallisation afforded a true racemate (racemic compound), which has been confirmed by X-ray crystallography. The aziridine obtained from the solution phase could be recrystallised to produce the pure enantiomer originally in excess. A consequence of the new findings is that previous reports on the enantioselectivity of copper-catalysed aziridination, both in heterogeneous and homogeneous conditions, should be regarded with caution if the analytical procedure involved HPLC with injection of the enantiomeric mixture in a hexane-rich solvent. Such a method has been used in previous work from this laboratory, but has also been used elsewhere, following the procedure developed by Evans and co-workers when the (homogeneous) copper-catalysed aziridination by PhINTs was first discovered. Evidently, the change of substituent in the benzenesulfonyl group reduces the solubility in hexane, affording a solution phase of enhanced ee. PMID:21186395

  17. Physicians’ perception of generic and electronic prescribing: A descriptive study from Jordan

    PubMed Central

    2014-01-01

    Objectives The aim of this study was to investigate Jordanian physicians’ perception and attitudes toward generic medicines and generic substitution. It also aimed to examine factors that affect physicians’ pattern of prescribing, and to evaluate their opinion regarding future introduction of Electronic Prescribing (EP) in Jordan. Methods A cross-sectional descriptive study involving Jordanian physicians working in both public and private sectors was undertaken, using a self-administrated anonymous questionnaire. Frequency tables, cross-tabulation and chi square tests were used for data analysis. The response rate was 75.2% (n = 376/500). Results Cost was claimed to be an important factor in the prescribing decision for 69.1% of the Jordanian physicians. The majority of physicians (77.4%) claimed that they often prescribe generic medicines. Jordanian physicians predominantly welcomed the implementation of an EP and International Nonproprietary Name (INN) prescribing systems with 92%, and 80.1% respectively. More than two thirds of the physicians (69.4%) accepted generic substitution by pharmacists, with a significant association with their employment sector; physicians who work in the private sector tended to oppose generic substitution compared with physicians who work in the public sector. Physicians mostly (72.1%) opposed that generic substitution should only be allowed upon patient request. Conclusions Jordanian physicians have a positive attitude towards generic medications and high willingness and acceptance of strategies that encourage generic utilisation such as EP, INN prescribing and generic substitution. All these strategies would help reduce the high expenditure on medicines in Jordan. These findings would provide baseline data to policy makers to develop a robust generic policy to achieve greater clinical effectiveness and economic efficiency from medicines prescribing. PMID:25848547

  18. Marine Isotope Stage 3 recorded in palaeolake sediments in the Eastern Alps

    NASA Astrophysics Data System (ADS)

    Starnberger, Reinhard; Rodnight, Helena; Reitner, Jürgen M.; Reimer, Paula J.; Spötl, Christoph

    2010-05-01

    Greenland ice core data indicate that the last glaciation in the Northern Hemisphere was characterized by relatively short and rapid warmings followed by gradual coolings (Greenland Interstadials or Dansgaard-Oeschger (D/O) cycles). While the Last Glacial Maximum (LGM) and the following Late Glacial are well documented in the Eastern Alps, continuous records of the time period preceding the LGM are only known from stalagmites. Although most of sediment which filled the Alpine valleys before the LGM was eroded and redeposited during the LGM, thick successions have been locally preserved along the sides of margins of longitudinal valley-forming distinct terraces. The Inn valley in Tyrol (Austria) offers the most striking examples of such river terraces which are known to be mostly composed of Upper Pleistocene sediments in the Eastern Alps. During the past 15 years a large number of continuously-cored drill cores was obtained during a tunnelling project in the lower Inn valley, offering the unique possibility to study these sediments in great detail. This study focuses on the Unterangerberg terrace near Wörgl, where drill cores penetrated lacustrine sediments underlying LGM gravel and till. Radiocarbon and infrared stimulated luminescence (IRSL) dating show that these sediments were deposited during Marine Isotope Stage (MIS) 3 and reach back into MIS 4. The sediments show cyclic changes in grain size coinciding with the abundance of biogenic material (charophyta, plant macro-remains, mollusc shells, etc.). In some cores 1-2 m organic-rich (lignite) layers are also present. Ongoing work aims at establishing a reliable internal chronostratigraphy using radiocarbon and luminescence in order to link proxy data series (grain size, loss on ignition, pollen data) to the pattern of D/O events known from Greenland and other regional archives.

  19. Effect of GOES-R Image Navigation and Registration Errors on Atmospheric Motion Vectors

    NASA Technical Reports Server (NTRS)

    Jedlovec, Gary

    2008-01-01

    High temporal frequency imagery from geostationary satellites allows for the continuous monitoring of rapidly changing atmospheric constituents such as smoke, dust, water vapor and clouds. The image sequences are often used to quantify the displacement of image features such as water vapor and clouds to produce atmospheric motion vectors (AMVs) which are used as diagnostic tools and also assimilated into numerical weather forecast models. The basic principle behind the determination of AMVs is the calculation of the physical displacement of features from one image (time) to the next. This process assumes that the features being tracked do not change as a function of time, usually requiring the use of short time interval imagery to minimize substantial change in size and shape of the features being tracked. High spatial resolution imagery also is required for reliable feature identification. While these image resolution and temporal sampling requirements often provide major drivers for space-based instrument design requirements, accurate image navigation and registration, INn (between a sequence of images), is also critical to the derivation of useful AMVs. In this paper and poster to be presented at the conference, the image navigation and registration (INR) accuracy expected for the Advanced Baseline Imager (ABI) on the GOES-R series of satellites will be discussed in light of its impact on AMV accuracy. Significant satellite platform and modeling enhancements are planned which should significantly improve INn performance of the GOES-R instruments. Some of these improvements have been demonstrated for the GOES-13 satellite which was launched in summer of 2006. An analysis of GOES-13 INR data, from the special satellite check out period, will be used in the assessment.

  20. Results from the 2010 Feb 14 and July 4 Pluto Occultations

    NASA Astrophysics Data System (ADS)

    Young, Leslie; Sicardy, B.; Widemann, T.; Brucker, M. J.; Buie, M. W.; Fraser, B.; Van Heerden, H.; Howell, R. R.; Lonergan, K.; Olkin, C. B.; Reitsema, H. J.; Richter, A.; Sepersky, T.; Wasserman, L. H.; Young, E. F.

    2010-10-01

    The Portable High-speed Occultation Telescope (PHOT) group observed two occultations by Pluto in 2010. The first, of a I=9.3 magnitudue star on 2010 Feb 14, was organized by the Meudon occultation group, with the PHOT group as collaborators. For this bright but low-elevation event, we deployed to three sites in Europe: Obs. Haute Provence, France (0.8-m; L. Young, H. Reitsema), Leopold Figl, Austria (1.5-m; E. Young), and Apline Astrovillage, Lu, Switzerland (0.36-m; C. Olkin, L. Wasserman). We obtained a lightcurve at Lu under clear conditions, which will be combined with two other lightcurves from the Meudon group, from Sisteron and Pic du Midi, France. We observed the second Pluto occultation, of a I=13.2 star on 2010 July 4 UT, from four sites in South Africa: with our portable telescope near Upington (0.36-m; M. Buie, L. Wasserman), the Boyden telescope in Bloemfontein (1.5-m; L. Young, M. Brucker), the Innes telescope in Johannesburg (0.67-m; T. Sepersky, B. Fraser), and the telescope at Aloe Ridge north of Johannesburg (0.62-m; R. Howell, K. Lonergan, A. Richter). Upington was cloudy, Boyden had heavy scattered clouds, and Innes suffered from haze and telescope mechanical problems. A lightcurve was obtained from Aloe Ridge under clear conditions. Data was also obtained by Karl-Ludwig Bath & Thomas Sauer at Hakos, Namibia and by Berto Monard of ASSA near Pretoria, South Africa. The length of the Aloe Ridge chord suggests it is nearly central. These observations give us four contiguous years in which we observed one or more Pluto occultations, providing constraints on the seasonal evolution of Pluto's atmosphere. Thanks are due to Marcelo Assafin and Jim Elliot for sharing predictions prior to the July event. This work was supported, in part, by NASA PAST NNX08A062G.

  1. Strain induced variations in band offsets and built-in electric fields in InGaN/GaN multiple quantum wells

    NASA Astrophysics Data System (ADS)

    Dong, L.; Mantese, J. V.; Avrutin, V.; Özgür, Ü.; Morkoç, H.; Alpay, S. P.

    2013-07-01

    The band structure, quantum confinement of charge carriers, and their localization affect the optoelectronic properties of compound semiconductor heterostructures and multiple quantum wells (MQWs). We present here the results of a systematic first-principles based density functional theory (DFT) investigation of the dependence of the valence band offsets and band bending in polar and non-polar strain-free and in-plane strained heteroepitaxial InxGa1-xN(InGaN)/GaN multilayers on the In composition and misfit strain. The results indicate that for non-polar m-plane configurations with [12¯10]InGaN//[12¯10]GaN and [0001]InGaN//[0001]GaN epitaxial alignments, the valence band offset changes linearly from 0 to 0.57 eV as the In composition is varied from 0 (GaN) to 1 (InN). These offsets are relatively insensitive to the misfit strain between InGaN and GaN. On the other hand, for polar c-plane strain-free heterostructures with [101¯0]InGaN//[101¯0]GaN and [12¯10]InGaN//[12¯10]GaN epitaxial alignments, the valence band offset increases nonlinearly from 0 eV (GaN) to 0.90 eV (InN). This is significantly reduced beyond x ≥ 0.5 by the effect of the equi-biaxial misfit strain. Thus, our results affirm that a combination of mechanical boundary conditions, epitaxial orientation, and variation in In concentration can be used as design parameters to rapidly tailor the band offsets in InGaN/GaN MQWs. Typically, calculations of the built-in electric field in complex semiconductor structures often must rely upon sequential optimization via repeated ab initio simulations. Here, we develop a formalism that augments such first-principles computations by including an electrostatic analysis (ESA) using Maxwell and Poisson's relations, thereby converting laborious DFT calculations into finite difference equations that can be rapidly solved. We use these tools to determine the bound sheet charges and built-in electric fields in polar epitaxial InGaN/GaN MQWs on c-plane Ga

  2. Molecular beam epitaxial growth and characterization of InSb{sub 1-x}N{sub x} on GaAs for long wavelength infrared applications

    SciTech Connect

    Patra, Nimai C.; Bharatan, Sudhakar; Li, Jia; Iyer, Shanthi; Tilton, Michael

    2012-04-15

    Recent research progress and findings in InSbN have attracted great attention due to its use in long wavelength infrared applications. A large bandgap reduction in InSb resulting from high N incorporation with minimal crystal defects is challenging due to relatively small atomic size of N. Hence optimization of growth conditions plays an important role in the growth of high-quality InSbN epilayers for device purposes. In this paper, we report on the correlation of structural, vibrational, electrical, and optical properties of molecular beam epitaxially grown InSbN epilayers grown on GaAs substrates, as a function of varying growth temperatures. Two dimensional growths of InSb and InSbN were confirmed from dynamic reflection high energy electron diffraction patterns and growth parameters were optimized. High crystalline quality of the epilayers is attested to by a low full width at half maximum of 200 arcsec from high resolution x-ray diffraction (HRXRD) scans and by the high intensity and well-resolved InSb longitudinal optical (LO) and 2{sup nd} order InSb LO mode observed from micro-Raman spectroscopy. The N incorporation in these InSbN epilayers is estimated to be 1.4% based on HRXRD simulation. X-ray photoelectron spectroscopy (XPS) studies reveal that most of the N present in the layers are in the form of In-N bonding. Variation of the lattice disorder with growth temperature is correlated with the types of N bonding present, the carrier concentration and mobility, observed in the corresponding XPS spectra and Hall measurements, respectively. XPS analysis, HRXRD scans, and Raman spectral analysis indicate that lower growth temperature favors In-N bonding which dictates N incorporation in the substitutional sites and lattice disorder, whereas, high growth temperature promotes the formation of In-N-Sb bonding. The best room temperature and 77 K electrical transport parameters and maximum redshift in the absorption edge have been achieved in the InSbN epilayer

  3. Chronostratigraphical investigations on Pleistocene fluvioglacial terraces of NW-Austria

    NASA Astrophysics Data System (ADS)

    Terhorst, B.

    2009-04-01

    Investigations on paleopedology and Quaternary stratigraphy were carried out in the area of fluvioglacial terraces of the rivers Inn and Traun/Enns. Research projects have been financed by the German Research Foundation (DFG) and the ICSU Grant Programme. Detailed studies were carried out on paleosols and loess sequences of different ages. The investigations of the research group were focused on loess/paleosol sequences located on top of Riss terraces (OIS 6 and older) as well as in areas with Mindel and Günz terraces. Loess records of the last glacial/interglacial cycle can be well observed in the study areas. Generally, the Eemian soil (O/S 5e) is developed as a reddish Bt-horizon in fluvioglacial gravels. U/Th-datings of calcites in the fluvioglacial sediments are indicating that soil formation took place in the catchment area about 113.000 ± 4.400 ka (Terhorst et al., 2002). The interglacial paleosol was truncated and a redeposited colluvial layer was deposited on top of the Bt-horizons containing charcaol with characteristic relicts of coniferous trees. After this land surface destabilisation phase, sedimentation of loess became the predominant process. Pedogenesis in form of a brown paleosol occurred, which partly has been redeposited. The pedocomplex is characterized by intense bioturbation of steppe animals. OSL-datings show that this part of the sequence belong to the Middle Würmian stage. The pedocomplex is overlain by a Cambisol corresponding to the youngest Middle Würmian interstadial. The paleosol is covered by thick loess deposits of the Upper Pleniglacial. Well-developed Tundragleysols subdivide the loess deposits. The uppermost soil corresponds to the Holocene Luvisol that includes hydromorphic properties. Older fluvioglacial terraces of Mindel and Günz age (in the classical stratigraphy) show a completely different structure of the covering layers (c.f. Kohl, 1999). In this case, several thick interglacial paleosols are embedded within records

  4. Effects of strain on the band structure of group-III nitrides

    NASA Astrophysics Data System (ADS)

    Yan, Qimin; Rinke, Patrick; Janotti, Anderson; Scheffler, Matthias; Van de Walle, Chris G.

    2014-09-01

    We present a systematic study of strain effects on the electronic band structure of the group-III-nitrides (AlN, GaN and InN) in the wurtzite phase. The calculations are based on density functional theory with band-gap-corrected approaches including the Heyd-Scuseria-Ernzerhof hybrid functional (HSE) and quasiparticle G0W0 methods. We study strain effects under realistic strain conditions, hydrostatic pressure, and biaxial stress. The strain-induced modification of the band structures is found to be nonlinear; transition energies and crystal-field splittings show a strong nonlinear behavior under biaxial stress. For the linear regime around the experimental lattice parameters, we present a complete set of deformation potentials (acz, act, D1, D2, D3, D4, D5, D6) that allows us to predict the band positions of group-III nitrides and their alloys (InGaN and AlGaN) under realistic strain conditions. The benchmarking G0W0 results for GaN agree well with the HSE data and indicate that HSE provides an appropriate description for the band structures of nitrides. We present a systematic study of strain effects on the electronic band structure of the group-III nitrides (AlN, GaN, and InN). We quantify the nonlinearity of strain effects by introducing a set of bowing parameters. We apply the calculated deformation potentials to the prediction of strain effects on transition energies and valence-band structures of InGaN alloys and quantum wells (QWs) grown on GaN, in various orientations (including c-plane, m-plane, and semipolar). The calculated band gap bowing parameters, including the strain effect for c-plane InGaN, agree well with the results obtained by hybrid functional alloy calculations. For semipolar InGaN QWs grown in (202¯1), (303¯1), and (303¯1¯) orientations, our calculated deformation potentials have provided results for polarization ratios in good agreement with the experimental observations, providing further confidence in the accuracy of our values.

  5. Growth and characterization of metalorganic chemical vapor deposition InGaN

    NASA Astrophysics Data System (ADS)

    Piner, Edwin Lanier

    1998-11-01

    The growth of InGaN with up to 53% InN content by the metalorganic chemical vapor deposition (MOCVD) technique has been conducted. The purpose of this study was to develop an understanding of the complex behavior of In incorporation on growth conditions. MOCVD growth of the nitrides requires higher temperatures than is typically experienced during the deposition of other III-V materials. This requirement was factored into the design and construction of an MOCVD system built specifically for the growth of III-nitrides. High quality heteroepitaxy nitride deposition also requires an adequate nucleation layer to enhance the properties of these wide band gap semiconductors. Two new methods for nucleation layer growth, atomic layer epitaxy (ALE) and molecular stream epitaxy were investigated and proven to adequately enhance GaN deposition. The ALE nucleation layer was utilized for the growth of the MOCVD InGaN films studied in this work. InN incorporation in InGaN has been observed to increase with decreasing growth temperature, increasing In and/or Ga flux, and first increase and then plateau with increasing V/III ratio. Additionally, metallic In droplets can form on the nitride film surface under non-optimized growth conditions. These results were explained by considering the possible reaction pathways available to the In species: Incorporation, desorption, and In metal formation. A dependence of the In incorporation rate on very low flow rates of hydrogen was discovered and explained by a site blocking effect of the hydrogen at the surface hindering the incorporation of the In. This hydrogen adsorbed on the surface was also responsible for the observed decrease in the hydrogen, carbon, and oxygen impurity concentrations in the film. These InGaN epitaxial films were also analyzed to determine the occurrence of phase separation in the InGaN material system. A transition from single phase to multiphase InGaN was observed to occur between 21 and 28% In content and was

  6. Relating rock avalanche morphology to emplacement processes

    NASA Astrophysics Data System (ADS)

    Dufresne, Anja; Prager, Christoph; Bösmeier, Annette

    2015-04-01

    The morphology, structure and sedimentological characteristics of rock avalanche deposits reflect both internal emplacement processes and external influences, such as runout path characteristics. The latter is mainly predisposed by topography, substrate types, and hydrogeological conditions. Additionally, the geological setting at the source slope controls, e.g. the spatial distribution of accumulated lithologies and hence material property-related changes in morphology, or the maximum clast size and amount of fines of different lithological units. The Holocene Tschirgant rock avalanche (Tyrol, Austria) resulted from failure of an intensely deformed carbonate rock mass on the southeast face of a 2,370-m-high mountain ridge. The initially sliding rock mass rapidly fragmented as it moved towards the floor of the Inn River valley. Part of the 200-250 x 106 m3 (Patzelt 2012) rock avalanche debris collided with and moved around an opposing bedrock ridge and flowed into the Ötz valley, reaching up to 6.3 km from source. Where the Tschirgant rock avalanche spread freely it formed longitudinal ridges aligned along motion direction as well as smaller hummocks. Encountering high topography, it left runup ridges, fallback patterns (i.e. secondary collapse), and compressional morphology (successively elevated, transverse ridges). Further evidence for the mechanical landslide behaviour is given by large volumes of mobilized valley-fill sediments (polymict gravels and sands). These sediments indicate both shearing and compressional faulting within the rock avalanche mass (forming their own morphological units through, e.g. in situ bulldozing or as distinctly different hummocky terrain), but also indicate extension of the spreading landslide mass (i.e. intercalated/injected gravels encountered mainly in morphological depressions between hummocks). Further influences on its morphology are given by the different lithological units. E.g. the transition from massive dolomite

  7. A conceptual, distributed snow redistribution model

    NASA Astrophysics Data System (ADS)

    Frey, S.; Holzmann, H.

    2015-11-01

    When applying conceptual hydrological models using a temperature index approach for snowmelt to high alpine areas often accumulation of snow during several years can be observed. Some of the reasons why these "snow towers" do not exist in nature are vertical and lateral transport processes. While snow transport models have been developed using grid cell sizes of tens to hundreds of square metres and have been applied in several catchments, no model exists using coarser cell sizes of 1 km2, which is a common resolution for meso- and large-scale hydrologic modelling (hundreds to thousands of square kilometres). In this paper we present an approach that uses only gravity and snow density as a proxy for the age of the snow cover and land-use information to redistribute snow in alpine basins. The results are based on the hydrological modelling of the Austrian Inn Basin in Tyrol, Austria, more specifically the Ötztaler Ache catchment, but the findings hold for other tributaries of the river Inn. This transport model is implemented in the distributed rainfall-runoff model COSERO (Continuous Semi-distributed Runoff). The results of both model concepts with and without consideration of lateral snow redistribution are compared against observed discharge and snow-covered areas derived from MODIS satellite images. By means of the snow redistribution concept, snow accumulation over several years can be prevented and the snow depletion curve compared with MODIS (Moderate Resolution Imaging Spectroradiometer) data could be improved, too. In a 7-year period the standard model would lead to snow accumulation of approximately 2900 mm SWE (snow water equivalent) in high elevated regions whereas the updated version of the model does not show accumulation and does also predict discharge with more accuracy leading to a Kling-Gupta efficiency of 0.93 instead of 0.9. A further improvement can be shown in the comparison of MODIS snow cover data and the calculated depletion curve, where

  8. Outbreak of cryptosporidiosis after contamination of the public water supply in Saitama Prefecture, Japan, in 1996.

    PubMed

    Yamamoto, N; Urabe, K; Takaoka, M; Nakazawa, K; Gotoh, A; Haga, M; Fuchigami, H; Kimata, I; Iseki, M

    2000-06-01

    An outbreak of cryptosporidiosis occurred in Ogose Town, Saitama Prefecture. Japan, in June 1996. Of 12,345 respondents to a questionnaire sent to households in the town (population; 13,809), 8,812 (71.4%) reported an acute gastrointestinal illness some time between May and July. In addition, 274 traceable visitors at local inns, golf courses, and the like during this period and 54 employees from out of town were infected. Cases of cryptosporidiosis were estimated to 9,140. Of these, 2,856 subjects were treated at outpatient clinics and 24 subjects were hospitalized (some subjects counted twice). No deaths were attributed to the outbreak. Among the visitors to Ogose who were traced, 7 persons who stayed only one day during the outbreak and drank half a glass to 2 glasses (100 to 360 ml) of tap water had cryptosporidiosis confirmed by laboratory tests. The median incubation period for the 14 persons for whom this calculation was possible was 6.4 days (range, 5 to 8 days). Of 469 pupils reporting details of their fever and diarrhea, abdominal cramps, or these combined signs and symptoms, the median maximum body temperature was 37.8 degrees C (range, 36.7 to 40.3 degrees C). The duration of illness, reported by 608 of the pupils, was 5.2 days (range, 1 to 15 days), and that reported by 187 employees was 4.8 days (range, 1 to 18 days). The longest known time for discharge of oocysts after onset was 44 days. Blood was not found in the 609 stool specimens examined. The outbreak was caused by contamination of the town's potable water by Cryptosporidium parvum oocysts. The town's water treatment plant treated river water by coagulation, sedimentation, sand filtration, and chlorination. Contamination arose because of various natural and artificial factors: one was that the monthly precipitation in May was much lower than average, causing the river water level to drop. Another factor was heavy rainfall one night in May that increased water turbidity. The amounts of the

  9. The isotropic-nematic and nematic-nematic phase transition of binary mixtures of tangent hard-sphere chain fluids: An analytical equation of state

    NASA Astrophysics Data System (ADS)

    van Westen, Thijs; Vlugt, Thijs J. H.; Gross, Joachim

    2014-01-01

    An analytical equation of state (EoS) is derived to describe the isotropic (I) and nematic (N) phase of linear- and partially flexible tangent hard-sphere chain fluids and their mixtures. The EoS is based on an extension of Onsager's second virial theory that was developed in our previous work [T. van Westen, B. Oyarzún, T. J. H. Vlugt, and J. Gross, J. Chem. Phys. 139, 034505 (2013)]. Higher virial coefficients are calculated using a Vega-Lago rescaling procedure, which is hereby generalized to mixtures. The EoS is used to study (1) the effect of length bidispersity on the I-N and N-N phase behavior of binary linear tangent hard-sphere chain fluid mixtures, (2) the effect of partial molecular flexibility on the binary phase diagram, and (3) the solubility of hard-sphere solutes in I- and N tangent hard-sphere chain fluids. By changing the length bidispersity, two types of phase diagrams were found. The first type is characterized by an I-N region at low pressure and a N-N demixed region at higher pressure that starts from an I-N-N triphase equilibrium. The second type does not show the I-N-N equilibrium. Instead, the N-N region starts from a lower critical point at a pressure above the I-N region. The results for the I-N region are in excellent agreement with the results from molecular simulations. It is shown that the N-N demixing is driven both by orientational and configurational/excluded volume entropy. By making the chains partially flexible, it is shown that the driving force resulting from the configurational entropy is reduced (due to a less anisotropic pair-excluded volume), resulting in a shift of the N-N demixed region to higher pressure. Compared to linear chains, no topological differences in the phase diagram were found. We show that the solubility of hard-sphere solutes decreases across the I-N phase transition. Furthermore, it is shown that by using a liquid crystal mixture as the solvent, the solubility difference can by maximized by tuning the

  10. Influence of Internal Electric Field on the Recombination Dynamics of Localized Excitons in an InGaN Double-Quantum-Well Laser Diode Wafer Operated at 450 nm

    NASA Astrophysics Data System (ADS)

    Onuma, Takeyoshi; Chichibu, Shigefusa F.; Aoyama, Toyomi; Nakajima, Kiyomi; Ahmet, Parhat; Azuhata, Takashi; Chikyow, Toyohiro; Sota, Takayuki; Nagahama, Shin-ichi; Mukai, Takashi

    2003-12-01

    Optical and structural properties of an InGaN double-quantum-well (DQW) laser diode (LD) wafer that lased at 450 nm were investigated to discuss an enormous impact of a polarization-induced electric field on the recombination dynamics in InGaN quantum structures. The quantum-well (QW) structure was shown to have the well thickness as thin as approximately 1 nm and InN molar fraction x of approximately 14%. The gross effective electric field in the QW (FQW) was estimated to be 490 kV/cm from the Franz-Keldysh oscillation (FKO) period in the electroreflectance (ER) spectrum, implying that an internal piezoelectric field (Fpiz) of approximately 1.4 MV/cm was cancelled by the pn junction built-in field (Fbi) and Coulomb screening due to carriers in the DQW. The magnitude of FQW can be further weakened by applying reverse bias (VR) on the junction; the decrease in the photoluminescence (PL) lifetime at low temperature measured under VR was explained to be due to a recovery of electron-hole wavefunction overlap for small VR (|VR|<4 V), and due mainly to the tunneling escape of carriers through the barriers for larger VR. By applying an appropriate VR smaller than 4 V, electron-hole wavefunction overlap, which had been separated vertically along the c-axis due to quantum-confined Stark effect, could be partially recovered, and then the time-resolved PL signals exhibited a less-pronounced stretched exponential decay, giving a scaling parameter (β) of 0.85 and effective in-plane localization depth (E0) of 40-50 meV for the spontaneous emission. These values were closer to those of much homogeneous QWs compared to those reported previously for InGaN QWs having similar InN molar fractions. The use of very thin QWs is considered to bring easier Coulomb screening of FQW and population inversion under high excitation conditions.

  11. Solution secondary structure of a bacterially expressed peptide from the receptor binding domain of Pseudomonas aeruginosa pili strain PAK: A heteronuclear multidimensional NMR study.

    PubMed

    Campbell, A P; Bautista, D L; Tripet, B; Wong, W Y; Irvin, R T; Hodges, R S; Sykes, B D

    1997-10-21

    The C-terminal receptor binding region of Pseudomonas aeruginosa pilin protein strain PAK (residues 128-144) has recently been the target for the design of a synthetic peptide vaccine effective against multiple strains of P. aeruginosa infection. We have successfully cloned and bacterially expressed a 15N-labeled PAK pilin peptide spanning residues 128-144 of the intact PAK pilin protein, PAK 128-144(Hs145), and have determined the solution secondary structure of this peptide using heteronuclear multidimensional NMR spectroscopy. The oxidized recombinant peptide exists as a major (trans) and minor (cis) species in solution, arising from isomerization around the Ile138-Pro139 peptide bond. The pattern of NOEs, temperature coefficients, and coupling constants observed for the trans isomer demonstrate the presence of a type I beta-turn and a type II beta-turn spanning Asp134-Glu-Gln-Phe137 and Pro139-Lys-Gly-Cys142, respectively. This is in agreement with the NMR solution structure of the trans isomer of a synthetic PAK 128-144 peptide which showed a type I and a type II beta-turn in these same regions of the sequence [McInnes, C., Sönnichsen, F. D., Kay, C. M., Hodges, R. S., and Sykes, B. D. (1993) Biochemistry 32, 13432-13440; Campbell, A. P., McInnes, C., Hodges, R. S., and Sykes, B. D. (1995) Biochemistry 34, 16255-16268]. The pattern of NOEs, temperature coefficients, and coupling constants observed for the cis isomer also demonstrate a type II beta-turn spanning Pro139-Lys-Gly-Cys142, but suggest a second beta-turn spanning Asp132-Gln-Asp-Glu135. Thus, the cis isomer may also possess a double-turn motif (like the trans isomer), but with different spacing between the turns and a different placement of the first turn in the sequence. The discovery of a double-turn motif in the trans (and cis) recombinant PAK pilin peptide is an extremely important result since the double turn has been implicated as a structural requirement for the recognition of both receptor

  12. Electronic structure calculations of group III nitride clusters

    NASA Astrophysics Data System (ADS)

    Kandalam, Anil Kumar

    2002-04-01

    Group III nitrides have become materials of choice in the manufacturing of devices used in opto-electronic and high-temperature high-power electronic industries. Hence, these materials received wide attention and have become the focus of several theoretical and experimental studies. Though these materials are studied in bulk and thin film forms, research at the cluster level is still lacking. Hence, a first principles calculation, based on the Generalized Gradient Approximation (GGA) to Density Functional Theory (DFT) was initiated to study the structural and electronic properties of AlnN n, GanNn, and InnNn, (n = 1--6) clusters. The calculated results show that the small polyatomic nitride clusters (monomer, triatomic and dimer) have a strong tendency to form N-N multiple bonds leading to the weakening of any existent metal-N or metal-metal bonds. In the absence of the N-N bonds, the metal-nitrogen bond dominates, forming short bond-lengths and large force constants. However, the strength of these heteronuclear bonds decreases in going from Al to Ga and In, whereas the weak metal-metal bond increases its strength from Al to Ga to In in the nitride clusters. Starting from the trimers M3N3, a distinct structural difference between the lowest energy configurations of AlnNn and that of GanNn, and In nNn, clusters has been observed. For AlnNn, clusters, the metal-nitrogen bond is found to dominate the lowest energy configurations. As the cluster size is increased from Al3N3 to Al 6N6, a transition from planar ring structures towards a bulk-like three dimensional configurations is seen. However, in GanN n, and InnNn clusters, no such trend is observed and the lowest energy configurations are dominated either by N2 or (N3)- sub-units. The segregation of N atoms within the stoichiometric clusters indicates the possibility of N2 and N3 based defects in the thin-film deposition process which may affect the quality of the thin-film devices based on Group III nitrides.

  13. Magnesium sulfate protects fetal skin from intrauterine ischemia reperfusion injury.

    PubMed

    Kaptanoglu, Asli F; Arca, Turkan; Kilinc, Kamer

    2012-09-01

    Intrauterine ischemia-reperfusion (I/R) injury in fetus occurs with multifactorial pathogenesis and results with multiorgan injury including skin. Magnesium has widespread use in obstetric practice. Inn addition to magnesium's tocolytic and neuroprotective properties, it also has free radical reducing effects. The aim of the present study was to demonstrate whether magnesium sulfate could have protective effect on fetal rat skin in intrauterine ischemia-reperfusion (I/R) injury. Fetal skin ischemia was induced by clamping the utero-ovarian arteries bilaterally for 30 min, and reperfusion was achieved by removing the clamps for 60 min in 19-day pregnant rats. Magnesium Sulfate (MgSO(4)) was given to pregnant rats 20 min before I/R injury at the dose of 600 mg/kg in magnesium treatment group. No ischemia reperfusion was applied to control and sham-operated groups. Lipid peroxidation from the skin tissues was determined as thiobarbituric acid reactive substances (TBARS). Myeloperoxidase (MPO) activity was determined for neutrophil activation. The results showed that the levels of TBARS and MPO increased significantly in the fetal rat skin after I/R injury compared to control group. Levels of TBARS and MPO were significantly lower than those of I/R group in Magnesium-treated group. In conclusion, intrauterine ischemia-reperfusion may produce considerable fetal skin injury. Increased TBARS and MPO activity can be inhibited by magnesium treatment. This suggests that magnesium treatment may have protective effect on fetal rat skin in intrauterine I/R injury.

  14. FOREWORD: The physics of III-V nitrides The physics of III-V nitrides

    NASA Astrophysics Data System (ADS)

    Ridley, B. K.

    2009-04-01

    The evolution of semiconductor physics is driven by the increasing sophistication of the art of crystal growing and fabrication techniques. From Ge at the birth of the transistor, possibly the purest material ever grown, through Si, the work-horse of the crystal revolution, to the III-Vs, whose optical properties opened up a second front, namely, optoelectronics. Crystal growth with monolayer control gave us quantum wells, superlattices, quantum wires and quantum dots, along with the quantum Hall effect and quantized resistance. The potential for high-power devices triggered interest in the III-V nitrides with their large bandgaps. The nitrides mostly crystallize in the hexagonal form, and this has introduced the phenomenon of spontaneous polarization into mainstream semiconductor physics. Its effect manifests itself in huge electric fields in heterostructures like AlGaN/GaN which, in turn, causes the induction of substantial electron populations in the channel of a HFET without the need for doping. High-power microwave transistors have been successfully fabricated, even though there are features associated with spontaneous polarization that still needs clarifying. Another strange effect is the large electron population on the surface of InN. The lack of a suitable substrate for growing GaN has meant that the dislocation density is higher than we would wish, but that situation is expected to steadily improve. Given the current interest in the physics of nitrides, it is natural to come across a special issue devoted to this topic. The difficulty presented by the surface layer in InN in the attempt to measure transport properties is discussed in the paper by King et al. A property that can affect transport is the lifetime of optical phonons and its dependence on electron density. Measurements of phonon lifetime in InN are reported by Tsen and Ferry, and in GaN channels, via the measure of hot-electron fluctuations, by Matulionis. The dependence on electron density is

  15. The Role of Tourism and Recreation in the Spread of Non-Native Species: A Systematic Review and Meta-Analysis.

    PubMed

    Anderson, Lucy G; Rocliffe, Steve; Haddaway, Neal R; Dunn, Alison M

    2015-01-01

    Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor recreation involve the frequent congregation of people, vehicles and vessels from geographically diverse areas. They are therefore perceived to be major pathways for the movement of non-native species, and ones that will become increasingly important with the continued growth of these sectors. However, a global assessment of the relationship between tourism activities and the introduction of non-native species-particularly in freshwater and marine environments-is lacking. We conducted a systematic review and meta-analysis to determine the impact of tourism and outdoor recreation on non-native species in terrestrial, marine and freshwater environments. Our results provide quantitative evidence that the abundance and richness of non-native species are significantly higher in sites where tourist activities take place than in control sites. The pattern was consistent across terrestrial, freshwater and marine environments; across a variety of vectors (e.g. horses, hikers, yachts); and across a range of taxonomic groups. These results highlight the need for widespread biosecurity interventions to prevent the inadvertent introduction of invasive non-native species (INNS) as the tourism and outdoor recreation sectors grow. PMID:26485300

  16. Influences of updated land-use datasets on WRF simulations for two Austrian regions

    NASA Astrophysics Data System (ADS)

    Schicker, Irene; Arnold Arias, Dèlia; Seibert, Petra

    2016-06-01

    Numerical simulations were carried out with the weather research and forecasting model to study the influence of different land-use datasets for two Austrian regions, the high-alpine Inn Valley area and the hilly Vienna Basin area. The three land-use datasets used were USGS, MODIS and a reclassified European dataset based on the CORINE CLC06 data. Simulations covered an episode in July 2007 applying a resolution of 0.8 km. Results were compared with surface observation data, radiosoundings, and satellite data. It was found that land-use both in the original CLC06 and the version where it had been reclassified to USGS classes for use in WRF was significantly more realistic than the built-in land-use datasets (USGS and MODIS). Synoptic processes during the episode considered were reproduced well by all simulations, where CLC06 and MODIS improved the model performance in both regions in terms of the surface temperatures and other meteorological parameters.

  17. Progress in piezo-phototronic effect modulated photovoltaics.

    PubMed

    Que, Miaoling; Zhou, Ranran; Wang, Xiandi; Yuan, Zuqing; Hu, Guofeng; Pan, Caofeng

    2016-11-01

    Wurtzite structured materials, like ZnO, GaN, CdS, and InN, simultaneously possess semiconductor and piezoelectric properties. The inner-crystal piezopotential induced by external strain can effectively tune/control the carrier generation, transport and separation/combination processes at the metal-semiconductor contact or p-n junction, which is called the piezo-phototronic effect. This effect can efficiently enhance the performance of photovoltaic devices based on piezoelectric semiconductor materials by utilizing the piezo-polarization charges at the junction induced by straining, which can modulate the energy band of the piezoelectric material and then accelerate or prevent the separation process of the photon-generated electrons and vacancies. This paper introduces the fundamental physics principles of the piezo-phototronic effect, and reviews recent progress in piezo-phototronic effect enhanced solar cells, including solar cells based on semiconductor nanowire, organic/inorganic materials, quantum dots, and perovskite. The piezo-phototronic effect is suggested as a suitable basis for the development of an innovative method to enhance the performance of solar cells based on piezoelectric semiconductors by applied extrinsic strains, which might be appropriate for fundamental research and potential applications in various areas of optoelectronics. PMID:27603785

  18. Density Functional Theory Calculation of the Band Alignment of (101̅0) In(x)Ga(1-x)N/Water Interfaces.

    PubMed

    Meng, Andrew C; Cheng, Jun; Sprik, Michiel

    2016-03-01

    Conduction band edge (CBE) and valence band edge (VBE) positions of InxGa1-xN photoelectrodes were computed using density functional theory methods. The band edges of fully solvated GaN and InN model systems were aligned with respect to the standard hydrogen electrode using a molecular dynamics hydrogen electrode scheme applied earlier to TiO2/water interfaces. Similar to the findings for TiO2, we found that the Purdew-Burke-Ernzerhof (PBE) functional gives a VBE potential which is too negative by 1 V. This cathodic bias is largely corrected by application of the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional containing a fraction of Hartree-Fock exchange. The effect of a change of composition was investigated using simplified model systems consisting of vacuum slabs covered on both sides by one monolayer of H2O. The CBE was found to vary linearly with In content. The VBE, in comparison, is much less sensitive to composition. The data show that the band edges straddle the hydrogen and oxygen evolution potentials for In fractions less than 47%. The band gap was found to exceed 2 eV for an In fraction less than 54%.

  19. Quantitation of human immunodeficiency virus type 1 infection kinetics.

    PubMed Central

    Dimitrov, D S; Willey, R L; Sato, H; Chang, L J; Blumenthal, R; Martin, M A

    1993-01-01

    Tissue culture infections of CD4-positive human T cells by human immunodeficiency virus type 1 (HIV-1) proceed in three stages: (i) a period following the initiation of an infection during which no detectable virus is produced; (ii) a phase in which a sharp increase followed by a peak of released progeny virions can be measured; and (iii) a final period when virus production declines. In this study, we have derived equations describing the kinetics of HIV-1 accumulation in cell culture supernatants during multiple rounds of infection. Our analyses indicated that the critical parameter affecting the kinetics of HIV-1 infection is the infection rate constant k = Inn/ti, where n is the number of infectious virions produced by one cell (about 10(2)) and ti is the time required for one complete cycle of virus infection (typically 3 to 4 days). Of particular note was our finding that the infectivity of HIV-1 during cell-to-cell transmission is 10(2) to 10(3) times greater than the infectivity of cell-free virus stocks, the inocula commonly used to initiate tissue culture infections. We also demonstrated that the slow infection kinetics of an HIV-1 tat mutant is not due to a longer replication time but reflects the small number of infectious particles produced per cycle. PMID:8445728

  20. Hot-pressed silicon nitride with various lanthanide oxides as sintering additives

    NASA Technical Reports Server (NTRS)

    Ueno, K.; Toibana, Y.

    1984-01-01

    The effects of addition of various lanthanide oxides and their mixture with Y2O3 on the sintering of Si3N4 were investigated. The addition of simple and mixed lanthanide oxides promoted the densification of Si3N4 in hot-pressing at 1800 C under 300-400kg/ centimeters squared for 60 min. The crystallization of yttrium and lanthanide-silicon oxynitrides which was observed inn the sintered body containing yttrium-lanthanide mixed oxides as additives led to the formation of a highly refractory Si3N4 ceramic having a bending strength of 82 and 84 kg/millimeters squared at room temperature and 1300 C respectively. In a Y2O3+La2O3 system, a higher molar ratio of La2O3 to Y2O3 gave a higher hardness and strength at high temperatures. It was found that 90 min was an optimum sintering time for the highest strength.

  1. Effects of misfit dislocations and AlN buffer layer on the GaInN/GaN phase diagram of the growth mode

    NASA Astrophysics Data System (ADS)

    Nakajima, Kazuo; Ujihara, Toru; Miyashita, Satoru; Sazaki, Gen

    2001-01-01

    The thickness-composition phase diagrams of the growth modes were determined for the GaInN-on-GaN (GaInN/GaN) and the GaInN-on-AlN-on-GaN (GaInN/AlN/GaN) structures. For this determination, the strain energy was calculated by considering the stress relaxation due to introduction of misfit dislocations, the surface energy was estimated from bonding enthalpy of the nearest-neighbor bonds on the surface, and the interface energy was estimated by considering both effects of the dangling bonds due to lattice misfit and the abrupt transition of bonding species at the heterointerface. From these phase diagrams, it was found that the layer-by-layer growth such as the Frank-van der Merwe mode was very difficult to obtain for the epitaxial growth of GaInN on GaN when the InN fraction is large. The Volmer-Weber mode is dominant in the phase diagram of the GaInN/GaN structures. The influence of an AlN buffer layer with a larger surface energy was studied by introducing an AlN layer between the GaInN layer and the GaN substrate. It was known that the layer-by-layer growth could be more easily obtained if misfit dislocations were introduced and an AlN layer was used as a buffer.

  2. Low-resistivity and transparent indium-oxide-doped ZnO ohmic contact to p-type GaN

    SciTech Connect

    Lim, Jae-Hong; Hwang, Dae-Kue; Kim, Hyun-Sik; Oh, Jin-Yong; Yang, Jin-Ho; Navamathavan, R.; Park, Seong-Ju

    2004-12-20

    We report on the indium-oxide-doped ZnO (IZO) transparent ohmic contact to the p-GaN. The IZO transparent ohmic contact layer was deposited on p-GaN by e-beam evaporation. The transmittance of an IZO film with a thickness of 250 nm was 84%-92% for the light in the wavelength range of 400 and 600 nm. In addition, the IZO contact film yielded a low specific contact resistance of 3.4x10{sup -4} {omega} cm{sup 2} on p-GaN when annealed at 600 deg. C for 5 min under a nitrogen ambient. Auger electron spectroscopy and x-ray photoemission spectroscopy analyses of the IZO and p-GaN interface indicated that Ga atoms had out-diffused and an InN phase was formed at the interface region after the thermal annealing process, resulting in a decrease in contact resistance. The light output power of a light-emitting diode (LED) with an IZO ohmic contact layer was increased by 34% at 83 mW of electrical input power compared to that of a LED with a Ni/Au ohmic contact layer.

  3. Drug packaging in 2015: risky industry choices and lax regulation.

    PubMed

    2016-06-01

    Prescrire examined the packaging quality of 240 drugs in 2015. No new advances were identified, but drug packaging continues to expose patients to a variety of dangers. Some past advances persist: for example, INNs are often more legible, and recent patient leaflets tend to be clearer and more informative. But these measures are not applied to all drugs, and are rarely applied retroactively to older drugs. The overall picture in 2015 is that many drugs are difficult to identify, risky or downright dangerous to prepare, or supplied with patient leaflets that fail to correctly inform patients about their medication. And measures to prevent drug poisoning in children need to be completely rethought. It is high time for regulators and policy makers to take the issue of drug packaging seriously, so blatant are the signs of their failure to do so: the increasing use of bulk bottles for new drugs; failure to implement guidelines on safe drug packaging (unit-dose presentations, appropriate dosing devices, etc.); and expanding umbrella brands which, given the dangers they pose to patients, should be banned instead. All things considered, healthcare professionals and patients must remain vigilant and report any dangers they identify. A major European initiative on drug packaging is becoming increasingly necessary.

  4. Proceedings of the second conference on radiation protection and dosimetry

    SciTech Connect

    Swaja, R. E.; Sims, C. S.

    1988-11-01

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base.

  5. Status of ion implantation doping and isolation of III-V nitrides

    SciTech Connect

    Zolper, J.C.; Pearton, S.J.; Abernathy, C.R.

    1995-09-01

    Ion implantation doping and isolation has played a critical role in the realization of high performance photonic and electronic devices in all mature semiconductor material systems. This is also expected to be the case for the binary III-V nitrides (InN, GaN, and AlN) and their alloys as the epitaxial material quality improves and more advanced device structures are fabricated. With this in mind, we review the status of implant doping and isolation of GaN and the ternary alloys AlGaN, InGaN, and InAlN. In particular, we reported on the successful n- and p-type doping of GaN by ion implantation of Mg+P and Si, respectively, and subsequent high temperature rapid thermal anneals in excess of 1000{degrees}C. In the area of implant isolation, N-implantation has been shown to compensate both n- and p-type GaN, N and O-implantation effectively compensates InAlN, and InGaN shows limited compensation with either N or F implantation.

  6. Self-screening of the quantum confined Stark effect by the polarization induced bulk charges in the quantum barriers

    SciTech Connect

    Zhang, Zi-Hui; Liu, Wei; Ju, Zhengang; Tiam Tan, Swee; Ji, Yun; Kyaw, Zabu; Zhang, Xueliang; Wang, Liancheng; Wei Sun, Xiao E-mail: volkan@stanfordalumni.org; Volkan Demir, Hilmi E-mail: volkan@stanfordalumni.org

    2014-06-16

    InGaN/GaN light-emitting diodes (LEDs) grown along the polar orientations significantly suffer from the quantum confined Stark effect (QCSE) caused by the strong polarization induced electric field in the quantum wells, which is a fundamental problem intrinsic to the III-nitrides. Here, we show that the QCSE is self-screened by the polarization induced bulk charges enabled by designing quantum barriers. The InN composition of the InGaN quantum barrier graded along the growth orientation opportunely generates the polarization induced bulk charges in the quantum barrier, which well compensate the polarization induced interface charges, thus avoiding the electric field in the quantum wells. Consequently, the optical output power and the external quantum efficiency are substantially improved for the LEDs. The ability to self-screen the QCSE using polarization induced bulk charges opens up new possibilities for device engineering of III-nitrides not only in LEDs but also in other optoelectronic devices.

  7. Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants.

    PubMed

    Hehle, Verena K; Paul, Matthew J; Roberts, Victoria A; van Dolleweerd, Craig J; Ma, Julian K-C

    2016-04-01

    This study examined the degradation pattern of a murine IgG1κ monoclonal antibody expressed in and extracted from transformedNicotiana tabacum Gel electrophoresis of leaf extracts revealed a consistent pattern of recombinant immunoglobulin bands, including intact and full-length antibody, as well as smaller antibody fragments. N-terminal sequencing revealed these smaller fragments to be proteolytic cleavage products and identified a limited number of protease-sensitive sites in the antibody light and heavy chain sequences. No strictly conserved target sequence was evident, although the peptide bonds that were susceptible to proteolysis were predominantly and consistently located within or near to the interdomain or solvent-exposed regions in the antibody structure. Amino acids surrounding identified cleavage sites were mutated in an attempt to increase resistance. Different Guy's 13 antibody heavy and light chain mutant combinations were expressed transiently inN. tabacumand demonstrated intensity shifts in the fragmentation pattern, resulting in alterations to the full-length antibody-to-fragment ratio. The work strengthens the understanding of proteolytic cleavage of antibodies expressed in plants and presents a novel approach to stabilize full-length antibody by site-directed mutagenesis.-Hehle, V. K., Paul, M. J., Roberts, V. A., van Dolleweerd, C. J., Ma, J. K.-C. Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants. PMID:26712217

  8. Strength of the Lewis-Brønsted Superacids Containing In, Sn, and Sb and the Electron Binding Energies of Their Corresponding Superhalogen Anions.

    PubMed

    Czapla, Marcin; Skurski, Piotr

    2015-12-24

    The HInnF3n+1, HSnnF4n+1, and HSbnF5n+1 (n = 1-3) compounds and their corresponding InnF3n+1(-), SnnF4n+1(-), SbnF5n+1(-) (n = 1-3) anions were investigated by employing the B3LYP, QCISD, and OVGF quantum chemistry methods and the LANL2DZ/6-311++G(d,p) basis sets. Our calculations revealed very strong acidity of all examined neutral compounds and large electronic stabilities (in the range 9.9-13.3 eV) of their corresponding anions. The gas phase acidities (manifested by small Gibbs free energies of deprotonation, ΔGacid) predicted for the HSn3F13 and HSb3F16 (ΔGacid of 243.5 and 230.3 kcal/mol at T = 298.15 K, respectively) suggest that these systems should actually act as even stronger acids than the F(SO3)4H and HSbF6 compounds (recognized thus far as the strongest superacids). PMID:26637507

  9. Workshop on rock mechanics issues in repository design and performance assessment

    SciTech Connect

    1996-04-01

    The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ``Rock Mechanics Issues in Repository Design and Performance Assessment`` on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions. Selected papers have been indexed separately for inclusion the Energy Science and Technology Database.

  10. Functional exercise of Kingsley Dam emergency action plan

    SciTech Connect

    Boyd, K.M.

    1995-12-31

    At the request of the Federal Energy Regulatory Commission (F.E.R.C.), the Central Nebraska Public Power and Irrigation District (Central) performed a Functional Test of the Kingsley Dam Emergency Action Plan (E.A.P.) on October 27, 1992. The purpose of the exercise was to evaluate the Emergency Action Plan under a stress-induced environment with time constraints that exercised skills which are required for emergency management. This exercise was unique as it took place simultaneously at three different sites: North Platte Holiday Inn, Lincoln County Civil Defense Headquarters and the Keith County Civil Defense Office. Fifty miles separated the two Civil Defense Headquarters. There was a mobile command post that allowed radio communications between the different Civil Defenses offices. During the exercise, both levels of the E.A.P. (hazardous situation developing and failure has occurred) were tested. Both Keith and Lincoln County Civil Defense offices were able to test their own preparedness plans and communications. Besides the successful tests of the plans, a cooperative spirit was strengthened among the agencies as well as an exchange of knowledge and resources.

  11. A review of the electrical properties of semiconductor nanowires: insights gained from terahertz conductivity spectroscopy

    NASA Astrophysics Data System (ADS)

    Joyce, Hannah J.; Boland, Jessica L.; Davies, Christopher L.; Baig, Sarwat A.; Johnston, Michael B.

    2016-10-01

    Accurately measuring and controlling the electrical properties of semiconductor nanowires is of paramount importance in the development of novel nanowire-based devices. In light of this, terahertz (THz) conductivity spectroscopy has emerged as an ideal non-contact technique for probing nanowire electrical conductivity and is showing tremendous value in the targeted development of nanowire devices. THz spectroscopic measurements of nanowires enable charge carrier lifetimes, mobilities, dopant concentrations and surface recombination velocities to be measured with high accuracy and high throughput in a contact-free fashion. This review spans seminal and recent studies of the electronic properties of nanowires using THz spectroscopy. A didactic description of THz time-domain spectroscopy, optical pump-THz probe spectroscopy, and their application to nanowires is included. We review a variety of technologically important nanowire materials, including GaAs, InAs, InP, GaN and InN nanowires, Si and Ge nanowires, ZnO nanowires, nanowire heterostructures, doped nanowires and modulation-doped nanowires. Finally, we discuss how THz measurements are guiding the development of nanowire-based devices, with the example of single-nanowire photoconductive THz receivers.

  12. Progress in piezo-phototronic effect modulated photovoltaics

    NASA Astrophysics Data System (ADS)

    Que, Miaoling; Zhou, Ranran; Wang, Xiandi; Yuan, Zuqing; Hu, Guofeng; Pan, Caofeng

    2016-11-01

    Wurtzite structured materials, like ZnO, GaN, CdS, and InN, simultaneously possess semiconductor and piezoelectric properties. The inner-crystal piezopotential induced by external strain can effectively tune/control the carrier generation, transport and separation/combination processes at the metal-semiconductor contact or p-n junction, which is called the piezo-phototronic effect. This effect can efficiently enhance the performance of photovoltaic devices based on piezoelectric semiconductor materials by utilizing the piezo-polarization charges at the junction induced by straining, which can modulate the energy band of the piezoelectric material and then accelerate or prevent the separation process of the photon-generated electrons and vacancies. This paper introduces the fundamental physics principles of the piezo-phototronic effect, and reviews recent progress in piezo-phototronic effect enhanced solar cells, including solar cells based on semiconductor nanowire, organic/inorganic materials, quantum dots, and perovskite. The piezo-phototronic effect is suggested as a suitable basis for the development of an innovative method to enhance the performance of solar cells based on piezoelectric semiconductors by applied extrinsic strains, which might be appropriate for fundamental research and potential applications in various areas of optoelectronics.

  13. Group-III Nitride Etch Selectivity in BCl(3)/Cl(2) ICP Plasmas

    SciTech Connect

    Abernathy, C.R.; Han, J.; Hong, J.; Lester, L.F.; Pearton, S.J.; Shul, R.J.; Willison, C.G.; Zhang, L.

    1998-12-09

    Patterning the group-IH nitrides has been challenging due to their strong bond energies and relatively inert chemical nature as compared to other compound semiconductors. Plasma etch processes have been used almost exclusively to pattern these films. The use of high-density plasma etch systems, including inductively coupled plasmas (ICP), has resulted in relatively high etch rates (often greater than 1.0 pmhnin) with anisotropic profiles and smooth etch morphologies. However, the etch mechanism is often dominated by high ion bombardment energies which can minimize etch selectivity. The use of an ICP-generated BCl~/C12 pkyma has yielded a highly versatile GaN etch process with rates ranging from 100 to 8000 A/rnin making this plasma chemistry a prime candidate for optimization of etch selectivity. In this study, we will report ICP etch rates and selectivities for GaN, AIN, and InN as a function of BCl~/Clz flow ratios, cathode rf-power, and ICP-source power. GaN:InN and GaN:AIN etch selectivities were typically less than 7:1 and showed the strongest dependence on flow ratio. This trend maybe attributed to faster GaN etch rates observed at higher concentrations of atomic Cl which was monitored using optical emission spectroscopy (OES). ~E~~~~f:~ INTRODUCTION DEC j 4898 Etch selectivi

  14. Stability and electronic structures of isoelectronic impurity complexes in Si: First-principles study

    NASA Astrophysics Data System (ADS)

    Iizuka, Shota; Nakayama, Takashi

    2016-10-01

    The stability and electronic structures of various isoelectronic cation+anion pairs in Si were studied by first-principles calculations. It was shown that the nearest-neighboring substitutional configuration is the most stable structure for most cation+anion pairs, while B+N, Mg+O, and Be+O pairs preferentially occupy a single Si site owing to the small atomic radii of B, N, and O atoms. We found that only Al+N, Ga+N, and In+N pairs produce electron-unoccupied weakly localized states in the band gap of Si, reflecting the large negativity of N atoms. We also showed that single N doping produces N+N pairs and that such pairs induce no electronic states in the band gap of Si. Therefore, the codoping of Al and N atoms is essential to produce an electronic state in the Si band gap and increase the tunneling current in Si tunneling field-effect transistors.

  15. Improved Strain-Free GaN Growth with a Nearly Lattice-Matched AlInN Interlayer by Metalorganic Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Oh, Tae Su; Jeong, Hyun; Seo, Tae Hoon; Lee, Yong Seok; Park, Ah Hyun; Kim, Hun; Jea Lee, Kang; Suh, Eun-Kyung

    2010-11-01

    Using metalorganic chemical vapor deposition, a strain-free GaN layer has been successfully grown by employing a 40-nm-thick nearly lattice-matched (NLM) Al1-xInxN as an interlayer. The Al1-xInxN interlayers having an InN molar fraction of x˜0.11 and 0.13 led to crack-networking at the GaN surface due to excessive tensile strain by lattice-mismatching. In the case of the GaN layer with a NLM Al1-xInxN interlayer (x˜0.18), however, strain-free GaN structure with improved structural and optical properties was demonstrated from the results of atomic force microscopy, Raman scattering and photoluminescence. By using transmission electron microscopy (TEM), the origin on strain-free state and improved properties of the GaN layer with the NLM AlInN interlayer was investigated. Based on TEM observations, we suggest that the faulted zone-like growth mechanism on roughed AlInN surface and partial compensation of tensile thermal stress are major factors on the improved strain-free GaN film.

  16. Enhancement in photoluminescence from 1 eV GaInNAs epilayers subject to 7 MeV electron irradiation

    NASA Astrophysics Data System (ADS)

    Pavelescu, E.-M.; Kudrawiec, R.; Bălţăţeanu, N.; Spânulescu, S.; Dumitrescu, M.; Guina, M.

    2013-02-01

    We have investigated the influence of 7 MeV electron irradiation (1014-1015 cm-2 range) and subsequent rapid thermal annealing (RTA) on luminescence efficiency of nearly lattice-matched 1 eV GaInNAs-on-GaAs epilayers, grown by molecular beam epitaxy. The study has been done by means of 9 K photoluminescence (PL) and 300 K photoreflectance (PR) spectroscopy. Electron irradiation was found to directly promote a notable increase in PL intensity. A further PL enhancement, remarkable at the higher annealing temperature, has been seen upon two RTA stages (at 800 and 900 °C) applied to irradiated samples as compared to a non-irradiated sample. This irradiation-promoted PL enhancement upon annealing occurred with a small additional blue-shift of PL for the lower temperature-annealed samples but no additional shift in PL was noted for the higher temperature-annealed sample. The additional annealing-induced PL blue-shift was mainly due to an irradiation-promoted enhancement in In-N bonds formation, whose magnitude does not appear to depend on dose within the studied range.

  17. Understanding and eliminating artifact signals from diffusely scattered pump beam in measurements of rough samples by time-domain thermoreflectance (TDTR).

    PubMed

    Sun, Bo; Koh, Yee Kan

    2016-06-01

    Time-domain thermoreflectance (TDTR) is a pump-probe technique frequently applied to measure the thermal transport properties of bulk materials, nanostructures, and interfaces. One of the limitations of TDTR is that it can only be employed to samples with a fairly smooth surface. For rough samples, artifact signals are collected when the pump beam in TDTR measurements is diffusely scattered by the rough surface into the photodetector, rendering the TDTR measurements invalid. In this paper, we systemically studied the factors affecting the artifact signals due to the pump beam leaked into the photodetector and thus established the origin of the artifact signals. We find that signals from the leaked pump beam are modulated by the probe beam due to the phase rotation induced in the photodetector by the illumination of the probe beam. As a result of the modulation, artifact signals due to the leaked pump beam are registered in TDTR measurements as the out-of-phase signals. We then developed a simple approach to eliminate the artifact signals due to the leaked pump beam. We verify our leak-pump correction approach by measuring the thermal conductivity of a rough InN sample, when the signals from the leaked pump beam are significant. We also discuss the advantages of our new method over the two-tint approach and its limitations. Our new approach enables measurements of the thermal conductivity of rough samples using TDTR.

  18. Ab Initio Prediction of Piezoelectricity in Two-Dimensional Materials.

    PubMed

    Blonsky, Michael N; Zhuang, Houlong L; Singh, Arunima K; Hennig, Richard G

    2015-10-27

    Two-dimensional (2D) materials present many unique materials concepts, including material properties that sometimes differ dramatically from those of their bulk counterparts. One of these properties, piezoelectricity, is important for micro- and nanoelectromechanical systems applications. Using symmetry analysis, we determine the independent piezoelectric coefficients for four groups of predicted and synthesized 2D materials. We calculate with density-functional perturbation theory the stiffness and piezoelectric tensors of these materials. We determine the in-plane piezoelectric coefficient d11 for 37 materials within the families of 2D metal dichalcogenides, metal oxides, and III-V semiconductor materials. A majority of the structures, including CrSe2, CrTe2, CaO, CdO, ZnO, and InN, have d11 coefficients greater than 5 pm/V, a typical value for bulk piezoelectric materials. Our symmetry analysis shows that buckled 2D materials exhibit an out-of-plane coefficient d31. We find that d31 for 8 III-V semiconductors ranges from 0.02 to 0.6 pm/V. From statistical analysis, we identify correlations between the piezoelectric coefficients and the electronic and structural properties of the 2D materials that elucidate the origin of the piezoelectricity. Among the 37 2D materials, CdO, ZnO, and CrTe2 stand out for their combination of large piezoelectric coefficient and low formation energy and are recommended for experimental exploration. PMID:26312745

  19. INSPECTION MEANS FOR INDUCTION MOTORS

    DOEpatents

    Williams, A.W.

    1959-03-10

    an appartus is descripbe for inspcting electric motors and more expecially an appartus for detecting falty end rings inn suqirrel cage inductio motors while the motor is running. In its broua aspects, the mer would around ce of reference tedtor means also itons in the phase ition of the An electronic circuit for conversion of excess-3 binary coded serial decimal numbers to straight binary coded serial decimal numbers is reported. The converter of the invention in its basic form generally coded pulse words of a type having an algebraic sign digit followed serially by a plurality of decimal digits in order of decreasing significance preceding a y algebraic sign digit followed serially by a plurality of decimal digits in order of decreasing significance. A switching martix is coupled to said input circuit and is internally connected to produce serial straight binary coded pulse groups indicative of the excess-3 coded input. A stepping circuit is coupled to the switching matrix and to a synchronous counter having a plurality of x decimal digit and plurality of y decimal digit indicator terminals. The stepping circuit steps the counter in synchornism with the serial binary pulse group output from the switching matrix to successively produce pulses at corresponding ones of the x and y decimal digit indicator terminals. The combinations of straight binary coded pulse groups and corresponding decimal digit indicator signals so produced comprise a basic output suitable for application to a variety of output apparatus.

  20. Exposure to ultrafine particles in hospitality venues with partial smoking bans.

    PubMed

    Neuberger, Manfred; Moshammer, Hanns; Schietz, Armin

    2013-01-01

    Fine particles in hospitality venues with insufficient smoking bans indicate health risks from passive smoking. In a random sample of Viennese inns (restaurants, cafes, bars, pubs and discotheques) effects of partial smoking bans on indoor air quality were examined by measurement of count, size and chargeable surface of ultrafine particles (UFPs) sized 10-300 nm, simultaneously with mass of particles sized 300-2500 nm (PM2.5). Air samples were taken in 134 rooms unannounced during busy hours and analyzed by a diffusion size classifier and an optical particle counter. Highest number concentrations of particles were found in smoking venues and smoking rooms (median 66,011 pt/cm(3)). Even non-smoking rooms adjacent to smoking rooms were highly contaminated (median 25,973 pt/cm(3)), compared with non-smoking venues (median 7408 pt/cm(3)). The particle number concentration was significantly correlated with the fine particle mass (P<0.001). We conclude that the existing tobacco law in Austria is ineffective to protect customers in non-smoking rooms of hospitality premises. Health protection of non-smoking guests and employees from risky UFP concentration is insufficient, even in rooms labeled "non-smoking". Partial smoking bans with separation of smoking rooms failed.