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Sample records for inns

  1. Think INN, prescribe INN, dispense INN: good professional practice.

    PubMed

    2000-12-01

    (1) International nonproprietary names (INN) for drugs were invented about fifty years ago, under the aegis of the World Health Organisation, to provide a common language for health professionals and patients worldwide. (2) No country forbids INN prescriptions. Some countries actively recommend using INNs. (3) INN prescription empowers prescribers and pharmacists in their choice of treatment. (4) The choice between a prescription based on the INN or the brand name will depend on the type of treatment (short term or chronic), the nature of the drug (especially its therapeutic margin) and any specific risks related to the patient (age, disease condition, allergy, and adherence). (5) A pharmacist's decision to dispense a brand name drug from an INN prescription must be based on usual dispensing precautions. (6) Adopting INN prescribing means having to reflect on one's knowledge of drugs, and to challenge the quality of one's initial and continuing education in pharmacology and therapeutics. The INN system is a means of improving prescribing and dispensing practices: it involves paying more attention to the patient, explaining the treatment in greater detail, and respecting his/her choice. PMID:11475502

  2. 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

  3. My working week: John Innes.

    PubMed

    Innes, John

    2016-07-23

    In the first of a new series of features for Vet Record Careers, John Innes describes a recent working week as referrals director for CVS and a RCVS specialist in small animal orthopaedics. PMID:27450857

  4. 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

  5. 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

  6. 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

  7. Defect Doping of InN

    SciTech Connect

    Jones, R.E.; van Genuchten, H.C.M.; Yu, K.M.; Walukiewicz, W.; Li, S.X.; A ger III, J.W.; Liliental-Weber, Z.; Haller, E.E.; Lu, H.; Schaff, W.J.

    2007-07-22

    InN films grown by molecular beam epitaxy have been subjected to 2 MeV He{sup +} irradiation followed by thermal annealing. Theoretical analysis of the electron mobilities shows that thermal annealing removes triply charged donor defects, creating films with electron mobilities approaching those predicted for uncompensated, singly charged donors. Optimum thermal annealing of irradiated InN can be used to produce samples with electron mobilities higher than those of as grown films.

  8. 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.

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

    MedlinePlus

    ... of this page please turn JavaScript on. Feature: The Children's Inn The Children's Inn at NIH turns 25 Past Issues / ... home …" for all families! What to Expect at The Children's Inn The Children's Inn enhances opportunities for ...

  10. 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

  11. 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.

  12. Inhomogeneities in MOVPE InN

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akio; Miwa, Hiroshi; Wang, Wen Jun; Hashimoto, Akihiro

    2006-01-01

    This paper reports the in-depth and in-plane inhomogeneities in InN films. Samples of InN are grown on sapphire substrates without or with a buffer using the atmospheric-pressure MOVPE. For the in-depth inhomogeneity analysis, the conventional PL measurement using an excitation source with a different wavelength is made from both the front surface and the film/substrate interface sides of samples. The measurement reveals that samples grown for a long time without buffer contain a deteriorated layer, which shows a higher PL peak energy, near the film/substrate interface. Such a layer is never found on the surface side. The deterioration is markedly enhanced when the sample is annealed in an NH3 flow. Since the coexistence of TMI and NH3 (growth environment) suppresses the deterioration and the InN samples used in this experiment have an In-polarity, such a deterioration is hydrogen-related degradation on the N-face of InN film. In-plane inhomogeneity of InN grown with a different buffer is studied by analyzing PL and absorption data. A wider PL spectrum and a larger discrepancy between PL peak energy and absorption edge, those are observed for films grown without buffer, are well explained by taking account of a large in-plane inhomogeneity in the samples. The existence of the large in-plane inhomogeneity is confirmed by the near-field PL mapping obtained by the SNOM. The SNOM analysis also shows that, although the use of the buffer improves the apparent in-plane uniformity, such a film has a fine inhomogeneity due to small grains of the buffer.

  13. Growth and characterizations of semipolar (1122) InN

    SciTech Connect

    Dinh, Duc V.; Skuridina, D.; Solopow, S.; Frentrup, M.; Pristovsek, M.; Vogt, P.; Kneissl, M.; Ivaldi, F.; Kret, S.; Szczepanska, A.

    2012-07-01

    We report on metal-organic vapor phase epitaxial growth of (1122) InN on (1122) GaN templates on m-plane (1010) sapphire substrates. The in-plane relationship of the (1122) InN samples is [1123]{sub InN} Double-Vertical-Line Double-Vertical-Line [0001]{sub sapphire} and [1100]{sub InN} Double-Vertical-Line Double-Vertical-Line [1210]{sub sapphire}, replicating the in-plane relationship of the (1122) GaN templates. The surface of the (1122) InN samples and the (1122) GaN templates shows an undulation along [1100]{sub InN,GaN}, which is attributed to anisotropic diffusion of indium/gallium atoms on the (1122) surfaces. The growth rate of the (1122) InN layers was 3-4 times lower compared to c-plane (0001) InN. High resolution transmission electron microscopy showed a relaxed interface between the (1122) InN layers and the (1122) GaN templates, consistent with x-ray diffraction results. Basal plane stacking faults were found in the (1122) GaN templates but they were terminated at the InN/(1122) GaN interface due to the presence of misfit dislocations along the entire InN/GaN interface. The misfit dislocations were contributed to the fully relaxation and the tilts of the (1122) InN layers. X-ray photoelectron spectroscopy was used to determine the polarity of the grown (1122) InN sample, indicating an In-polar (1122) InN. The valence band maximum was determined to be at (1.7 {+-} 0.1) eV for the (1122) InN sample, comparable to In-polar c-plane InN.

  14. 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.

  15. 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.

  16. Investigation of gas sensing properties of InN nanoparticles

    NASA Astrophysics Data System (ADS)

    Madapu, Kishore K.; Prasad, A. K.; Tyagi, A. K.; Dhara, S.

    2015-06-01

    InN nanoparticles were grown by chemical vapor deposition technique using In2O3 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 CH4 gas. Sensors substrates were fabricated with interdigitated Au electrodes. InN nanoparticles show high response towards CH4 with minimum detectable concentration of 50 ppm at 200 °C.

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

    MedlinePlus

    ... of this page please turn JavaScript on. Feature: The Children's Inn The Children's Inn at NIH Past Issues / Summer 2014 ... Contents Anniversary Key Messages Playground and Park at The Children's Inn at NIH. Photo courtesy of Mahan ...

  18. 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

  19. 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.

  20. The InN epitaxy via controlling In bilayer

    PubMed Central

    2014-01-01

    The method of In bilayer pre-deposition and penetrated nitridation had been proposed, which had been proven to have many advantages theoretically. To study the growth behavior of this method experimentally, various pulse times of trimethylindium supply were used to get the optimal indium bilayer controlling by metalorganic vapour phase epitaxy. The results revealed that the InN film quality became better as the thickness of the top indium atomic layers was close to bilayer. A following tuning of nitridation process enhanced the quality of InN film further, which means that a moderate, stable, and slow nitridation process by NH3 flow also plays the key role in growing better-quality InN film. Meanwhile, the biaxial strain of InN film was gradually relaxing when the flatness was increasingly improved. PMID:24393422

  1. Observation of Room Temperature Ferromagnetism in InN Nanostructures.

    PubMed

    Roul, Basanta; Kumar, Mahesh; Bhat, Thirumaleshwara N; Rajpalke, Mohana K; Krupanidhi, S B; Kumar, Nitesh; Sundaresan, A

    2015-06-01

    The room temperature ferromagnetic behavior of InN nanostructures grown by molecular beam epitaxy (MBE) is explored by means of magnetization measurements. The saturation magnetization and remanent magnetization are found to be strongly dependent on the size of the nanostructures. This suggests that the ferromagnetism is essentially confined to the surface of the nanostructures due to the possible defects. Raman spectroscopy shows the existence of indium vacancies which could be the source of ferromagnetic ordering in InN nanostructures. PMID:26369060

  2. Electrochromic reaction of InN thin films

    SciTech Connect

    Asai, Nobuaki; Inoue, Yasushi; Sugimura, Hiroyuki; Takai, Osamu

    1999-06-01

    Electrochromic (EC) reaction of indium nitride (InN) films prepared by radio frequency (rf) ion plating was studied through their chemical bonding states and crystalline structures as measured by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. In addition, the pH dependence of the EC reaction was characterized. Color of the InN films became darker or lighter when the InN films were polarized anodically or cathodically, respectively, in a Na{sub 2}SO{sub 4} solution. Similar color changes were observed when pH of the Na{sub 2}SO{sub 43} solution was changed from 4.0 to 11.6. The color change at one unit of pH difference corresponded to the EC color change at a potential difference of 59 mV. From these results, H{sup +} and OH{sup {minus}} were confirmed to be active reactants in the EC reaction of the InN films. On the other hand, it was revealed from XPS and XRD results that the amount of hydroxides formed at the grain boundaries and the surface of the anodically polarized InN films was greater than that of the film polarized cathodically. Therefore, the electrochromism of the InN films was concluded to be governed by chemisorption of H{sup +} and OH{sup {minus}} at grain boundaries.

  3. 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

  4. The INNs and outs of antibody nonproprietary names.

    PubMed

    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

  5. 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

  6. 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

  7. 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, ...

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

    MedlinePlus

    ... through mutual support including therapeutic, recreational, and educational programming. Establishment of The Inn took hard work, dedication ... 7 million for the expansion project. fast facts 1 The Children's Inn, located on the NIH campus ...

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

    MedlinePlus

    ... of this page please turn JavaScript on. Feature: The Children's Inn The Children's Inn at NIH - Three Stories Past Issues / Summer 2014 Table of Contents Kristal Nemeroff—The Patient Kristal Nemeroff, age 2, at the Children's ...

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

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues The Place Where Hope Lives: The Children's Inn Comforts Kids and Their Families Past ... Story by Melanie Modlin Photography by Veronika Lukasova The Children's Inn at NIH is a unique homeaway- ...

  11. 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.

  12. No Vacancy: Inn Provides Revenue Source for Financially Troubled Institute.

    ERIC Educational Resources Information Center

    Bridges, Jerry G.; Brant, Joseph F.

    1994-01-01

    The Peabody Institute of Baltimore (Maryland), the Johns Hopkins University's music school, addressed its financial problems by converting four campus buildings into an inn used to house Elderhostel participants. Annual program revenues cover all costs and yield a financial reserve for the school. (MSE)

  13. Growth of Mg-doped InN by Metal Organic Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Khan, N.; Nepal, N.; Lin, J. Y.; Jiang, H. X.

    2007-03-01

    InN with an energy gap of ˜ 0.7 eV, has recently attracted extensive attention due to its potential applications in semiconductor devices such as light emitting diodes, lasers, and high efficiency solar cells. However the ability to grow both p-type and n-type InN is essential to realize these devices. All as grown unintentionally doped InN are n-type. The tendency of native defects in InN to form donors manifests itself severely at surfaces where high levels of electron accumulation are observed. The highly n-type conductive layer at the surface of InN films creates difficulties in the demonstration of p-type InN. Nevertheless it is important to investigate the optical and structural properties of Mg-doped InN. We report here on the growth of Mg-doped InN epilayers by metal organic chemical vapor deposition. Photoluminescence (PL) was employed to study the effects of different growth conditions of Mg-doped InN. PL studies revealed that in addition to emission peak at ˜ 0.82 eV in undoped InN layers, Mg-doped InN layers exhibit an emission peak at ˜ 0.75 eV. The peak at ˜ 0.75eV for Mg-doped InN could be related to defects generated by Mg doping in InN. Various other measurements such as Hall effect measurement, X-ray diffraction and atomic force microscopy were carried out to provide further understanding.

  14. 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.

  15. Identification of Raman-active phonon modes in oriented platelets of InN and polycrystalline InN

    NASA Astrophysics Data System (ADS)

    Dyck, J. S.; Kim, K.; Limpijumnong, S.; Lambrecht, W. R. L.; Kash, K.; Angus, J. C.

    2000-04-01

    We report on micro-Raman studies on both randomly oriented polycrystals and groups of oriented, faceted platelets of indium nitride grown from the melt at subatmospheric pressures. Phonon modes were assigned as A1TO=445, E1TO=472, E2(2)=488, and A1LO=588 cm-1. The FWHM of the E2(2) peak of 2.5 cm -1 is the narrowest reported to date for InN. The measured TO phonon frequencies were compared to those calculated from first principles and excellent agreement was found. The results are discussed in the context of previously reported Raman experiments on heteroepitaxial, and hence strained, layers of InN.

  16. 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.

  17. Transmission Electron Microscopy Study of InN Nanorods

    SciTech Connect

    Liliental-Weber, Z.; Li, X.; Kryliouk, Olga; Park, H.J.; Mangum,J.; Anderson, T.

    2006-07-13

    InN nanorods were grown on a, c-, and r-plane of sapphire and also on Si (111) and GaN (0001) by non-catalytic, template-free hydride metal-organic vapor phase epitaxy and studied by transmission electron microscopy, electron energy loss (EELS) and photoluminescence (PL) at room temperature. These nanocrystals have different shapes and different faceting depending on the substrate used and their crystallographic orientation. EELS measurements have confirmed the high purity of these crystals. The observed PL peak was in the range of 0.9-0.95 eV. The strongest PL intensity was observed for the nanocrystals with the larger diameters.

  18. Evaluation of threading dislocation densities in In- and N-face InN

    SciTech Connect

    Gallinat, C. S.; Koblmueller, G.; Wu, Feng; Speck, J. S.

    2010-03-15

    The threading dislocation (TD) structure and density has been studied in In- and N-face InN films grown on GaN by plasma-assisted molecular beam epitaxy. The TD densities were determined by nondestructive x-ray diffraction rocking curve measurements in on-axis symmetric and off-axis skew symmetric geometries and calibrated by transmission electron microscopy measurements. TD densities were dominated by edge-type TDs with screw-component TDs accounting for less than 10% of the total TD density. A significant decrease in edge-type TD density was observed for In-face InN films grown at increasingly higher substrate temperatures. In-face InN films grown with excess In exhibited lower TD densities compared to films grown under N-rich conditions. The edge-type TD density of N-face InN films was independent of substrate temperature due to the higher allowable growth temperatures for N-face InN compared to In-face InN. TD densities in In-face InN also showed a strong dependence on film thickness. Films grown at a thickness of less than 1 {mu}m had higher TD densities compared with films grown thicker than 1 {mu}m. The lowest measured TD density for an In-face InN film was {approx}1.5x10{sup 10}/cm{sup 2} for 1 {mu}m thick films.

  19. Donor and acceptor concentrations in degenerate InN

    SciTech Connect

    Look, D.C.; Lu, H.; Schaff, W.J.; Jasinski, J.; Liliental-Weber, Z.

    2002-01-28

    A formalism is presented to determine donor (N{sub D}) and acceptor (N{sub A}) concentrations in wurtzitic InN characterized by degenerate carrier concentration (n) and mobility ({mu}). The theory includes scattering not only by charged point defects and impurities, but also by charged threading dislocations, of concentration N{sub dis}. For an 0.45-{micro}m-thick InN layer grown on Al{sub 2}O{sub 3} by molecular beam epitaxy, having N{sub dis} = 5 x 10{sup 10} cm{sup -2}, determined by transmission electron microscopy, n(20 K) = 3.5 x 10{sup 18} cm{sup -3}, and {mu}(20 K) = 1055 cm{sup 2}/V-s, determined by Hall-effect measurements, the fitted values are N{sub D} = 4.7 x 10{sup 18} cm{sup -3} and N{sub A} = 1.2 x 10{sup 18} cm{sup -3}. The identities of the donors and acceptors are not known, although a comparison of N{sub D} with analytical data, and also with calculations of defect formation energies, suggests that a potential candidate for the dominant donor is H.

  20. Auger recombination in InN from first principles

    NASA Astrophysics Data System (ADS)

    McAllister, Andrew; Kioupakis, Emmanouil

    Group-III Nitride materials are used in numerous electronic and optoelectronic devices including solid-state lighting, energy conversion, sensor technologies, and high-power electronics. Indium nitride in particular is interesting for fast electronics and optoelectronics in the infrared. Auger recombination is a non-radiative carrier recombination process that would limit the efficiency of these devices. The small band gap (0.7 eV) and the high intrinsic free-electron concentrations in InN possibly make Auger recombination particularly important in this material. We used first-principles computational methods to determine the Auger recombination rates in InN. Our results suggest that direct Auger recombination is dominant in this material and that phonon-assisted Auger processes are not as important as in wider-gap nitrides such as GaN. This research was supported by the National Science Foundation CAREER award through Grant No. DMR-1254314. Computational resources were provided by the DOE NERSC facility.

  1. 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.

  2. V-shaped inversion domains in InN grown on c-plane sapphire

    SciTech Connect

    Jasinski, J.; Liliental-Weber, Z.; Lu, H.; Schaff, W.J.

    2004-04-27

    Inversion domains with a V-shape were found to nucleate inside a Mg-doped InN heteroepitaxial layer. They resemble Al-polarity domains, observed recently, in N-polarity AlN films. However, the angle between the side-walls of the V-shaped domain and the c-axis differs in these two cases. In InN, this angle is almost two times bigger than that reported for AlN. The origin of V-shaped inversion domains in InN film is not yet clear.

  3. 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.

  4. Improvement of structural and electrical properties of Cu2O films with InN epilayers

    NASA Astrophysics Data System (ADS)

    Pan, Yang; Wang, Zheng; Peng, Ting; Wu, Kemin; Wu, Hao; Liu, Chang

    2011-11-01

    Epitaxial single crystalline Cu2O thin films were synthesized by thermal oxidation of Cu films, which were deposited on InN/sapphire using electron beam evaporation. Cu2O on InN shows a better crystalline quality than that on GaN due to a 30° in-plane rotation between Cu2O and InN, which results in a smaller lattice mismatch. As-oxidized Cu2O on GaN or on InN shows an n-type conducting behavior, however, as-oxidized Cu2O on InN presents a higher resistance and a lower electron concentration. A transition from n- to p-type is found after the Cu2O thin films are annealed at 500 °C in vacuum. A less Cu2+ absorption of the Cu2O/InN plays an important role to determine the conductive type.

  5. Mg acceptor level in InN epilayers probed by photoluminescence

    NASA Astrophysics Data System (ADS)

    Khan, N.; Nepal, N.; Sedhain, A.; Lin, J. Y.; Jiang, H. X.

    2007-07-01

    Mg-doped InN epilayers were grown on sapphire substrates by metal organic chemical vapor deposition. Effects of Mg concentration on the photoluminescence (PL) emission properties have been investigated. An emission line at ˜0.76eV, which was absent in undoped InN epilayers and was about 60meV below the band-to-band emission peak at ˜0.82eV, was observed to be the dominant emission in Mg-doped InN epilayers. The PL spectral peak position and the temperature dependent emission intensity corroborated each other and suggested that the Mg acceptor level in InN is about 60meV above the valance band maximum.

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

    MedlinePlus

    ... Lives: The Children's Inn Comforts Kids and Their Families Past Issues / Fall 2006 Table of Contents For ... home for children with serious illnesses and their families. Meet Channing O'Halloran. Before she was 1 ...

  7. Anomalous phase transition of InN nanowires under high pressure

    NASA Astrophysics Data System (ADS)

    Tang, Shun-Xi; Zhu, Hong-Yang; Jiang, Jun-Ru; Wu, Xiao-Xin; Dong, Yun-Xuan; Zhang, Jian; Yang, Da-Peng; Cui, Qi-Liang

    2015-09-01

    Uniform InN nanowires were studied under pressures up to 35.5 GPa by using in situ synchrotron radiation x-ray diffraction technique at room temperature. An anomalous phase transition behavior has been discovered. Contrary to the results in the literature, which indicated that InN undergoes a fully reversible phase transition from the wurtzite structure to the rocksalt type structure, the InN nanowires in this study unusually showed a partially irreversible phase transition. The released sample contained the metastable rocksalt phase as well as the starting wurtzite one. The experimental findings of this study also reveal the potentiality of high pressure techniques to synthesize InN nanomaterials with the metastable rocksalt type structure, in addition to the generally obtained zincblende type one. Project supported by the National Natural Science Foundation of China (Grant Nos. 50772043, 51172087, and 11074089).

  8. Growth and depth dependence of visible luminescence in wurtzite InN epilayers

    SciTech Connect

    Pu, X.D.; Shen, W.Z.; Zhang, Z.Q.; Ogawa, H.; Guo, Q.X.

    2006-04-10

    We present detailed investigation of growth and depth dependence of visible ({approx}1.9 eV) photoluminescence (PL) in wurtzite InN epilayers grown by magnetron sputtering. For normal surface incidence, PL peak was found to redshift with increasing growth temperatures. Cross-sectional PL measurements were able to separate contributions from the InN epilayers and sapphire substrates, which not only demonstrated the visible luminescence in InN but also revealed the blueshift of the PL peak with laser spot focusing from epilayer surface toward the interface. The results have been well explained by the growth mechanism and residual strain along growth direction of InN epilayers.

  9. Growth of a-Plane InN Film and Its THz Emission

    NASA Astrophysics Data System (ADS)

    Wang, Guang-Bing; Zhao, Guo-Zhong; Zheng, Xian-Tong; Wang, Ping; Chen, Guang; Rong, Xin; Wang, Xin-Qiang

    2014-07-01

    We report the growth of a-plane InN on an r-plane sapphire substrate by plasma-assisted molecular-beam epitaxy. It is found that the a-plane InN is successfully grown by using a GaN buffer layer, which has been confirmed by reflection high-energy electron diffraction, x-ray diffraction and Raman scattering measurements. The Hall effect measurement shows that the electron mobility of the as-grown a-plane InN is about 406 cm2 /V·s with a residual electron concentration of 5.7 × 10 cm-3. THz emission from the a-plane InN film is also studied, where it is found that the emission amplitude is inversely proportional to the conductivity.

  10. p-type conduction in Zn-ion implanted InN films

    NASA Astrophysics Data System (ADS)

    Xie, W. M.; Y Xie, Q.; Zhu, H. P.; Wang, W.; Cai, H. L.; Zhang, F. M.; Wu, X. S.

    2015-06-01

    We report p-type conductivity in wurtzite indium nitride (InN) experimentally and theoretically. The as-deposited InN films are implanted with various doses of Zn ions. The Hall coefficient is positive for samples with doses of 2.5 ~ 10   ×   1014 ions cm-2 at low temperature and turns negative as the temperature increases. This notable sign change of the Hall coefficient confirms the existence of mobile holes in Zn-implanted InN. Moreover, first principle calculations indicate that Zn may be a more stable p-type dopant in InN than that of Mg and Ba because of its low ionization energy.

  11. 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.

  12. 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.

  13. Transport and infrared photoresponse properties of InN nanorods/Si heterojunction

    PubMed Central

    2011-01-01

    The present work explores the electrical transport and infrared (IR) photoresponse properties of InN nanorods (NRs)/n-Si heterojunction grown by plasma-assisted molecular beam epitaxy. Single-crystalline wurtzite structure of InN NRs is verified by the X-ray diffraction and transmission electron microscopy. Raman measurements show that these wurtzite InN NRs have sharp peaks E2(high) at 490.2 cm-1 and A1(LO) at 591 cm-1. The current transport mechanism of the NRs is limited by three types of mechanisms depending on applied bias voltages. The electrical transport properties of the device were studied in the range of 80 to 450 K. The faster rise and decay time indicate that the InN NRs/n-Si heterojunction is highly sensitive to IR light. PMID:22122843

  14. Dynamic atomic layer epitaxy of InN on/in +c-GaN matrix: Effect of "In+N" coverage and capping timing by GaN layer on effective InN thickness

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Akihiko; Kusakabe, Kazuhide; Hashimoto, Naoki; Hwang, Eun-Sook; Itoi, Takaomi

    2016-01-01

    The growth front in the self-organizing and self-limiting epitaxy of ˜1 monolayer (ML)-thick InN wells on/in +c-GaN matrix by molecular beam epitaxy (MBE) has been studied in detail, with special attention given to the behavior and role of the N atoms. The growth temperatures of interest are above 600 °C, far higher than the typical upper critical temperature of 500 °C in MBE. It was confirmed that 2 ML-thick InN wells can be frozen/inserted in GaN matrix at 620 °C, but it was found that N atoms at the growth front tend to selectively re-evaporate more quickly than In atoms at temperatures higher than 650 °C. As a result, the effective thickness of inserted InN wells in the GaN matrix at 660-670 °C were basically 1 ML or sub-ML, even though they were capped by a GaN barrier at the time of 2 ML "In+N" coverage. Furthermore, it was found that the N atoms located below In atoms in the dynamic atomic layer epitaxy growth front had remarkably weaker bonding to the +c-GaN surface.

  15. 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.

  16. Drift current dominated terahertz radiation from InN at low-density excitation

    NASA Astrophysics Data System (ADS)

    Lin, K. I.; Tsai, J. T.; Wang, T. S.; Hwang, J. S.; Chen, M. C.; Chi, G. C.

    2008-12-01

    This letter investigates the polarity of terahertz radiation from indium nitride (InN) excited by femtosecond optical pulses wherein a central wavelength of around 790nm is measured. The InN epilayers are grown by metalorganic chemical vapor deposition on sapphire and silicon substrates. The polarity of the terahertz radiation field from InN is opposite to that from p-InAs whose radiation mechanism is dominated by the photo-Dember effect indicating that the dominant radiation mechanism in InN is the drift current induced by the internal electric field at low-density excitation below 590nJ /cm2. The internal electric field consists of the surface accumulation field and the spontaneous polarization-induced electric field. In addition, since no azimuthal angle dependence of the terahertz radiation is observed, the optical rectification effect is ruled out. By comparing the wave forms of terahertz radiation from the front and the back of the InN sample grown on sapphire in reflection geometry, the N polarity of the InN sample is confirmed.

  17. 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.

  18. 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

  19. MOVPE growth of InN films using 1,1-dimethylhydrazine as a nitrogen precursor

    NASA Astrophysics Data System (ADS)

    Thieu, Quang Tu; Seki, Yuki; Kuboya, Shigeyuki; Katayama, Ryuji; Onabe, Kentaro

    2009-05-01

    InN films have been successfully grown on sapphire substrates by MOVPE using trimethylindium (TMIn) and 1,1-dimethylhydrazine (DMHy) with N 2 carrier. DMHy is an advantageous precursor of N as it decomposes efficiently at relatively low temperature ( T50=420 °C) compatible with the InN growth. The reactor is specially designed so as to avoid parasitic reaction between TMIn and DMHy occurring at room temperature. The growth feature was studied by varying growth temperature, V/III ratio, TMIn flow and reactor pressure. The InN films were obtained at 500-570 °C and 60-200 Torr with a V/III ratio optimized to 100-200. The In droplets are seen on the grown surfaces, indicating an excess supply of TMIn. It is demonstrated that the InN films grows on the sapphire substrate in a single domain with an epitaxial relationship, [1 01¯ 0] InN//[1 1 2¯ 0] sapphire.

  20. Fe-doped InN layers grown by molecular beam epitaxy

    SciTech Connect

    Wang Xinqiang; Liu Shitao; Ma Dingyu; Zheng Xiantong; Chen Guang; Xu Fujun; Tang Ning; Shen Bo; Zhang Peng; Cao Xingzhong; Wang Baoyi; Huang Sen; Chen, Kevin J.; Zhou Shengqiang; Yoshikawa, Akihiko

    2012-10-22

    Iron(Fe)-doped InN (InN:Fe) layers have been grown by molecular beam epitaxy. It is found that Fe-doping leads to drastic increase of residual electron concentration, which is different from the semi-insulating property of Fe-doped GaN. However, this heavy n-type doping cannot be fully explained by doped Fe-concentration ([Fe]). Further analysis shows that more unintentionally doped impurities such as hydrogen and oxygen are incorporated with increasing [Fe] and the surface is degraded with high density pits, which probably are the main reasons for electron generation and mobility reduction. Photoluminescence of InN is gradually quenched by Fe-doping. This work shows that Fe-doping is one of good choices to control electron density in InN.

  1. High mobility InN epilayers grown on AlN epilayer templates

    NASA Astrophysics Data System (ADS)

    Khan, N.; Sedhain, A.; Li, J.; Lin, J. Y.; Jiang, H. X.

    2008-04-01

    We report on the growth of InN epilayers on AlN/sapphire templates by metal organic chemical vapor deposition. Compared to InN epilayers grown on GaN templates, significant improvements in the electrical and optical properties of InN epilayers on AlN templates were observed. An increase in electron mobility, a decrease in background electron concentration, and a redshift of photoluminescence emission peak position with increasing the growth temperature and V/III ratio were observed and a room temperature Hall mobility of 1400cm2/Vs with a free electron concentration of about 7×1018cm-3 was obtained. The improvements were partly attributed to the use of AlN templates, which allows for higher growth temperatures leading to an enhanced supply of nitrogen atoms and a possible reduction in the incorporation of unintentional impurities and nitrogen vacancy related defects.

  2. Spectral dependence of third-order nonlinear optical properties in InN

    NASA Astrophysics Data System (ADS)

    Ahn, H.; Lee, M.-T.; Chang, Y.-M.

    2014-05-01

    We report on the nonlinear optical properties of InN measured in a wide near-infrared spectral range with the femtosecond Z-scan technique. The above-bandgap nonlinear absorption in InN is found to originate from the saturation of absorption by the band-state-filling and its cross-section increases drastically near the bandgap energy. With below-bandgap excitation, the nonlinear absorption undergoes a transition from saturation absorption (SA) to reverse-SA (RSA), attributed to the competition between SA of band-tail states and two-photon-related RSA. The measured large nonlinear refractive index of the order of 10-10 cm2/W indicates InN as a potential material for all-optical switching and related applications.

  3. Spectral dependence of third-order nonlinear optical properties in InN

    SciTech Connect

    Ahn, H. Lee, M.-T.; Chang, Y.-M.

    2014-05-19

    We report on the nonlinear optical properties of InN measured in a wide near-infrared spectral range with the femtosecond Z-scan technique. The above-bandgap nonlinear absorption in InN is found to originate from the saturation of absorption by the band-state-filling and its cross-section increases drastically near the bandgap energy. With below-bandgap excitation, the nonlinear absorption undergoes a transition from saturation absorption (SA) to reverse-SA (RSA), attributed to the competition between SA of band-tail states and two-photon-related RSA. The measured large nonlinear refractive index of the order of 10{sup −10} cm{sup 2}/W indicates InN as a potential material for all-optical switching and related applications.

  4. Terahertz detectors arrays based on orderly aligned InN nanowires

    PubMed Central

    Chen, Xuechen; Liu, Huiqiang; Li, Qiuguo; Chen, Hao; Peng, Rufang; Chu, Sheng; Cheng, Binbin

    2015-01-01

    Nanostructured terahertz detectors employing a single semiconducting nanowire or graphene sheet have recently generated considerable interest as an alternative to existing THz technologies, for their merit on the ease of fabrication and above-room-temperature operation. However, the lack of alignment in nanostructure device hindered their potential toward practical applications. The present work reports ordered terahertz detectors arrays based on neatly aligned InN nanowires. The InN nanostructures (nanowires and nano-necklaces) were achieved by chemical vapor deposition growth, and then InN nanowires were successfully transferred and aligned into micrometer-sized groups by a “transfer-printing” method. Field effect transistors on aligned nanowires were fabricated and tested for terahertz detection purpose. The detector showed good photoresponse as well as low noise level. Besides, dense arrays of such detectors were also fabricated, which rendered a peak responsivity of 1.1 V/W from 7 detectors connected in series. PMID:26289498

  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. Electronic and optical properties of InN nanowires from first principles

    NASA Astrophysics Data System (ADS)

    Bayerl, Dylan; Kioupakis, Emmanouil

    2013-03-01

    Group-III-nitride nanowires are promising materials for photovoltaic and solid-state-lighting applications. We use first-principles calculations to investigate the electronic and optical properties of InN nanowires. Density functional theory provides the ground-state properties to which we subsequently apply quasiparticle corrections with the GW method. We thereby accurately predict the electronic band gaps, effective masses, and band dispersions of these nanostructured materials. We further solve the Bethe-Salpeter equation to predict the optical absorption spectra of InN nanowires as a function of cross-sectional dimension and geometry. We demonstrate that quantum confinement can increase the fundamental gap in InN nanowires as high as near-ultraviolet energies. This research was supported as part of CSTEC, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Computational resources were provided by the DOE NERSC facility.

  7. Hydrogen adsorbed at N-polar InN: Significant changes in the surface electronic properties

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    The interaction of atomic hydrogen and ammonia with as-grown N-polar InN surfaces is investigated using in situ photoelectron spectroscopy. Changes in the surface electronic properties, including the band alignment and work function, as well as the chemical bonding states of the substrate and adsorbates are characterized. Ammonia molecules are dissociating at the InN surface, resulting in adsorption of hydrogen species. Consequently, the considerable changes of the chemical and electronic properties of the InN surface during ammonia interaction are almost identical to those found for adsorption of atomic hydrogen. In both cases, hydrogen atoms preferentially bond to surface nitrogen atoms, resulting in the disappearance of the nitrogen dangling-bond-related occupied surface state close to the valence band edge at ˜1.6 eV binding energy and the formation of new occupied electron states at the conduction band edge. Furthermore, a decrease in work function during adsorption from 4.7 to 3.7-3.8 eV, as well as an increase in the surface downward band bending by 0.3 eV, confirm that hydrogen is acting as electron donor at InN surfaces and therefore has to be considered as one main reason for the surface electron accumulation observed at N-polar InN samples exposed to ambient conditions, for example as the dissociation product of molecules. The measured formation and occupation of electronic states above the conduction band minimum occur in conjunction with the observed increase in surface electron concentration and underline the relationship between the energy position of occupied electron states and surface band alignment for InN as a small-band-gap semiconductor.

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

    PubMed

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

    2016-12-01

    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 × 10(11) 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. PMID:27142879

  9. 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.

  10. 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.

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

    DOE PAGESBeta

    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

    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.

  13. 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.

  14. 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.

  15. Polycrystalline InN thin films prepared by ion-beam-assisted filtered cathodic vacuum arc technique

    NASA Astrophysics Data System (ADS)

    Ji, X. H.; Lau, S. P.

    2005-09-01

    We report on the fabrication of indium nitride (InN) thin films on silicon (1 0 0) substrates by radio frequency ion-beam-assisted filtered cathodic vacuum arc technique at low temperature. The effects of nitrogen ion energy on the structural properties of InN films have been investigated by X-ray diffraction and Raman spectroscopy. The InN films exhibit polycrystalline wurtzite structure. At nitrogen ion energy of 100 eV, the film shows preferred (0 0 0 2) orientation. The preferred orientation is changed to ( 1 0 1¯ 1) when the nitrogen ion energy is more than 100 eV. Three Raman-active optical phonons have been clearly identified and assigned to A 1(LO) at ˜588 cm -1, E22 at ˜490 cm -1 and A 1(TO) at ˜449 cm -1 of InN films, which confirmed the hexagonal structure of InN.

  16. Surface states and electronic structure of polar and nonpolar InN - An in situ photoelectron spectroscopy study

    SciTech Connect

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

    2013-06-10

    Valence band structure and surface states of InN with (0001), (000-1), (1-100), and (11-20) orientation were investigated in situ after growth using photoelectron spectroscopy. Depending on surface orientation, different occupied surface states are identified and differentiated from bulk contributions. For N-polar, m-plane, and a-plane InN, the surface states are located at the valence band maximum, while In-polar InN features surface states close to the Fermi level. The surface band alignment correlates with the position of surface states. For InN(0001), a much larger surface downward band bending is observed compared to N-polar, m-plane, and a-plane InN, where almost flat band conditions occur.

  17. 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.

  18. 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.

  19. Enhancement in c-Si solar cells using 16 nm InN nanoparticles

    NASA Astrophysics Data System (ADS)

    Imtiaz Chowdhury, Farsad; Alnuaimi, Aaesha; Alkis, Sabri; Ortaç, Bülend; Aktürk, Selçuk; Alevli, Mustafa; Dietz, Nikolaus; Kemal Okyay, Ali; Nayfeh, Ammar

    2016-05-01

    In this work, 16 nm indium nitride (InN) nanoparticles (NPs) are used to increase the performance of thin-film c-Si HIT solar cells. InN NPs were spin-coated on top of an ITO layer of c-Si HIT solar cells. The c-Si HIT cell is a stack of 2 μm p type c-Si, 4–5 nm n type a-Si, 15 nm n+ type a-Si and 80 nm ITO grown on a p+ type Si substrate. On average, short circuit current density (Jsc) increases from 19.64 mA cm‑2 to 21.54 mA cm‑2 with a relative improvement of 9.67% and efficiency increases from 6.09% to 7.09% with a relative improvement of 16.42% due to the presence of InN NPs. Reflectance and internal/external quantum efficiency (IQE/EQE) of the devices were also measured. Peak EQE was found to increase from 74.1% to 81.3% and peak IQE increased from 93% to 98.6% for InN NPs coated c-Si HIT cells. Lower reflection of light due to light scattering is responsible for performance enhancement between 400–620 nm while downshifted photons are responsible for performance enhancement from 620 nm onwards.

  20. 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.

  1. 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.

  2. Dopants and Defects in InN and InGaN Alloys

    SciTech Connect

    Walukiewicz, W.; Jones, R.E.; Li, S.X.; Yu, K.M.; Ager III, J.W.; Haller, E.E.; Lu, H.; Schaff, W.J.

    2005-04-01

    We have performed systematic studies of the effects of high-energy particle irradiation on the properties of InGaN alloys. In agreement with the amphoteric defect model, irradiation of InN produces donor-like defects. The electron concentration increases with increasing radiation dose and saturates at 4 x 10{sup 20} cm{sup -3} at very high doses. We find that the increase of the electron concentration causes a large blue-shift of the absorption edge, which is well-explained by the Burstein-Moss effect. The maximum electron concentration decreases with increasing Ga fraction in irradiated In{sub 1-x}Ga{sub x}N alloys as the conduction band edge approaches the Fermi level stabilization energy (E{sub FS}). For x > 0.66 the conduction band edge moves above E{sub FS} and the irradiation of n-type films produces acceptor-like defects, resulting in a reduced free electron concentration. An analysis of the concentration dependence of the electron mobility in InN indicates that the dominant defects in irradiated InN are triply-charged donors. Finally, we show that InN films doped with Mg acceptors behave like undoped films above a threshold radiation dose.

  3. 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.

  4. 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

  5. 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.

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  8. Strain distribution of thin InN epilayers grown on (0001) GaN templates by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Delimitis, A.; Komninou, Ph.; Dimitrakopulos, G. P.; Kehagias, Th.; Kioseoglou, J.; Karakostas, Th.; Nouet, G.

    2007-02-01

    A structural characterization of thin InN films is performed to determine the post-growth strain distribution, using electron microscopy techniques. A 60° misfit dislocation network at the InN /GaN interface effectively accommodates the lattice mismatch. The InN in-plane lattice parameter, which remained practically constant throughout the epilayer thickness, was precisely determined by electron diffraction analysis, and cross-section and plan-view lattice images. Image analysis using the geometric phase and projection methods revealed a uniform distribution of the residual tensile strain along the growth and lateral directions. The in-plane strain is primarily attributed to InN island coalescence during the initial stages of growth.

  9. 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.

  10. 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.

  11. High-quality InN films on GaN using graded InGaN buffers by MBE

    NASA Astrophysics Data System (ADS)

    Islam, SM; Protasenko, Vladimir; Rouvimov, Sergei; (Grace Xing, Huili; Jena, Debdeep

    2016-05-01

    The growth of high-quality thick InN films is challenging because of the lack of native substrates. In this work, we demonstrate the use of a linearly graded InGaN buffer layer for the growth of InN films on GaN substrates. A 500 nm InN film with <0.1 nm RMS roughness is obtained with a peak mobility of 1410 cm2/(V·s) at 300 K. A strong room temperature photoluminescence showing a bandgap of 0.65 eV with 79 meV linewidth is observed. A graded InGaN buffer is found to lead to extremely smooth and high-quality InN films.

  12. 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.

  13. 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.

  14. InN Nanorods and Epi-layers: Similarities and Differences

    SciTech Connect

    Liliental-Weber, Z.; Kryliouk, O.; Park, H.J.; Mangum, J.; Anderson, T.; Schaff, W.

    2007-03-30

    Transmission electron microscopy was applied to study InN nanorods grown on the a-, c-and r-plane of Al{sub 2}O{sub 3}, and (111) Si substrates by non-catalytic, template-free hydride metal-organic vapor phase epitaxy (H-MOVPE). Single crystal nanorod growth was obtained on all substrates. However, the shape of the nanorods varied depending on the substrate used. For example, nanorods grown on r-plane sapphire and (111) Si have sharp tips. In contrast, growth on a- and c- planes of Al{sub 2}O{sub 3} results in flat tips with clear facets on their sides. The structural quality of these nanorods and their growth polarity are compared to crystalline quality, surface roughness, defects and growth polarity of InN layers grown by MBE on the same planes of Al{sub 2}O{sub 3}.

  15. Metastable nature of InN and In-rich InGaN alloys

    NASA Astrophysics Data System (ADS)

    Ivanov, S. V.; Shubina, T. V.; Komissarova, T. A.; Jmerik, V. N.

    2014-10-01

    The paper provides a thermodynamic insight into the metastable nature of InN and In-rich InGaN alloys, based on experimental studies of their plasma-assisted MBE growth and high-temperature decomposition, as well as on theoretical modeling of nitrogen vacancy behavior. This instability may easily result in occurrence of metallic In nanoparticles in the bulk of In(Ga)N films and in the vicinity of extended defects at high enough In content, which makes us consider this material as a metal-semiconductor composite. An overview of a wide set of experimental studies performed by us on the epitaxial films grown in many laboratories all around the world is given which proves an existence of such In nanoparticles in the films and shows how they affect optical and electrical properties of the epilayers. Possible applications of epitaxial InN layers for THz emitters and magnetic field sensors are discussed.

  16. Solar hot water system installed at Days Inn Motel, Dallas, Texas (Valley View)

    SciTech Connect

    1980-09-01

    The solar hot water system installed in the Days Inns of America, Inc., Days Inn Motel (120 rooms), I-35/2276 Valley View Lane, Dallas, Texas is described. The solar system was designed by ILI Incorporated to provide 65 percent of the total domestic hot water (DHW) demand. The Solar Energy Products, model CU-30WW liquid (water) flat plate collector (1000 square feet) system automatically drains into the 1000 gallon steel storage tank when the solar pump is not running. This system is one of eleven systems planned. 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. The operation of this system was begun March 11, 1980. The solar components were partly funded ($15,000 of 30,000 cost) by a Department of Energy grant.

  17. Growth modes of InN (000-1) on GaN buffer layers on sapphire

    SciTech Connect

    Liu Bing; Kitajima, Takeshi; Chen Dongxue; Leone, Stephen R.

    2005-03-01

    In this work, using atomic force microscopy and scanning tunneling microscopy, we study the surface morphologies of epitaxial InN films grown by plasma-assisted molecular beam epitaxy with intervening GaN buffer layers on sapphire substrates. On smooth GaN buffer layers, nucleation and evolution of three-dimensional InN islands at various coverages and growth temperatures are investigated. The shapes of the InN islands are observed to be predominantly mesalike with large flat (000-1) tops, which suggests a possible role of indium as a surfactant. Rough GaN buffer layers composed of dense small GaN islands are found to significantly improve uniform InN wetting of the substrates, on which atomically smooth InN films are obtained that show the characteristics of step-flow growth. Scanning tunneling microscopy imaging reveals the defect-mediated surface morphology of smooth InN films, including surface terminations of screw dislocations and a high density of shallow surface pits with depths less than 0.3 nm. The mechanisms of the three-dimensional island size and shape evolution and formation of defects on smooth surfaces are considered.

  18. Growth modes of InN(000-1) on GaN buffer layers on sapphire

    SciTech Connect

    Liu, Bing; Kitajima, Takeshi; Chen, Dongxue; Leone, Stephen R.

    2005-01-24

    In this work, using atomic force microscopy and scanning tunneling microscopy, we study the surface morphologies of epitaxial InN films grown by plasma-assisted molecular beam epitaxy with intervening GaN buffer layers on sapphire substrates. On smooth GaN buffer layers, nucleation and evolution of three-dimensional InN islands at various coverages and growth temperatures are investigated. The shapes of the InN islands are observed to be predominantly mesa-like with large flat (000-1) tops, which suggests a possible role of indium as a surfactant. Rough GaN buffer layers composed of dense small GaN islands are found to significantly improve uniform InN wetting of the substrates, on which atomically smooth InN films are obtained that show the characteristics of step-flow growth. Scanning tunneling microscopy imaging reveals the defect-mediated surface morphology of smooth InN films, including surface terminations of screw dislocations and a high density of shallow surface pits with depths less than 0.3 nm. The mechanisms of the three-dimensional island size and shape evolution and formation of defects on smooth surfaces are considered.

  19. 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

  20. Chemical vapor deposition of m-plane and c-plane InN nanowires on Si (100) substrate

    NASA Astrophysics Data System (ADS)

    Rafique, Subrina; Han, Lu; Zhao, Hongping

    2015-04-01

    In this paper, synthesis of indium nitride (InN) nanowires (NWs) by chemical vapor deposition (CVD) is studied. InN NWs were synthesized via a vapor-liquid-solid (VLS) growth mechanism using high purity indium foil and ammonia as the source materials, and nitrogen as carrier gas. The mixture of nonpolar m-plane oriented and polar c-plane oriented tapered InN NWs is observed grown on top of Si (100) substrate. Energy dispersive spectroscopy (EDS) showed that the tips of the NWs are primarily consisted of Au and the rest of the NWs are consisted of indium (In) and nitrogen (N). High resolution scanning electron microscopy (HRSEM) revealed that the InN NWs have both triangular and hexagonal cross sections. Transmission electron microscopy (TEM) diffraction pattern showed that the NWs are high quality single crystals having wurtzite crystal structure. High resolution transmission electron microscopy (HRTEM) showed the growth directions of the InN NWs with triangular cross section are along <10-10> nonpolar m-plane orientation and the InN NWs with hexagonal cross section are along <0001> polar c-plane orientation.

  1. On the crystalline structure, stoichiometry and band gap of InN thin films

    SciTech Connect

    Yu, K.M.; Liliental-Weber, Z.; Walukiewicz, W.; Li, S.X.; Jones, R.E.; Shan, W.; Ager III, J.W.; Haller, E.E.; Lu, Hai; Schaff, William J.

    2004-09-23

    Detailed transmission electron microscopy (TEM), x-ray diffraction (XRD), and optical characterization of a variety of InN thin films grown by molecular beam epitaxy under both optimized and non-optimized conditions is reported. Optical characterization by absorption and photoluminescence confirms that the band gap of single crystalline and polycrystalline wurtzite InN is 0.70 {+-} 0.05 eV. Films grown under optimized conditions with a AlN nucleation layer and a GaN buffer layer are stoichiometric, single crystalline wurtzite structure with dislocation densities not exceeding mid-10{sup 10} cm{sup -2}. Non-optimal films can be poly-crystalline and display an XRD diffraction feature at 2{theta} {approx} 33{sup o}; this feature has been attributed by others to the presence of metallic In clusters. Careful indexing of wide angle XRD scans and selected area diffraction patterns shows that this peak is in fact due to the presence of polycrystalline InN grains; no evidence of metallic In clusters was found in any of the studied samples.

  2. 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.

  3. Low-temperature self-limiting atomic layer deposition of wurtzite InN on Si(100)

    NASA Astrophysics Data System (ADS)

    Haider, Ali; Kizir, Seda; Biyikli, Necmi

    2016-04-01

    In this work, we report on self-limiting growth of InN thin films at substrate temperatures as low as 200 °C by hollow-cathode plasma-assisted atomic layer deposition (HCPA-ALD). The precursors used in growth experiments were trimethylindium (TMI) and N2 plasma. Process parameters including TMI pulse time, N2 plasma exposure time, purge time, and deposition temperature have been optimized for self-limiting growth of InN with in ALD window. With the increase in exposure time of N2 plasma from 40 s to 100 s at 200 °C, growth rate showed a significant decrease from 1.60 to 0.64 Å/cycle. At 200 °C, growth rate saturated as 0.64 Å/cycle for TMI dose starting from 0.07 s. Structural, optical, and morphological characterization of InN were carried out in detail. X-ray diffraction measurements revealed the hexagonal wurtzite crystalline structure of the grown InN films. Refractive index of the InN film deposited at 200 °C was found to be 2.66 at 650 nm. 48 nm-thick InN films exhibited relatively smooth surfaces with Rms surface roughness values of 0.98 nm, while the film density was extracted as 6.30 g/cm3. X-ray photoelectron spectroscopy (XPS) measurements depicted the peaks of indium, nitrogen, carbon, and oxygen on the film surface and quantitative information revealed that films are nearly stoichiometric with rather low impurity content. In3d and N1s high-resolution scans confirmed the presence of InN with peaks located at 443.5 and 396.8 eV, respectively. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) further confirmed the polycrystalline structure of InN thin films and elemental mapping revealed uniform distribution of indium and nitrogen along the scanned area of the InN film. Spectral absorption measurements exhibited an optical band edge around 1.9 eV. Our findings demonstrate that HCPA-ALD might be a promising technique to grow crystalline wurtzite InN thin films at low substrate temperatures.

  4. High Cubic-Phase Purity InN on MgO (001) Using Cubic-Phase GaN as a Buffer Layer

    SciTech Connect

    Sanorpim, S.; Kuntharin, S.; Parinyataramas, J.; Yaguchi, H.; Iwahashi, Y.; Orihara, M.; Hijikata, Y.; Yoshida, S.

    2011-12-23

    High cubic-phase purity InN films were grown on MgO (001) substrates by molecular beam epitaxy with a cubic-phase GaN buffer layer. The cubic phase purity of the InN grown layers has been analyzed by high resolution X-ray diffraction, {mu}-Raman scattering and transmission electron microscopy. It is evidenced that the hexagonal-phase content in the InN overlayer much depends on hexagonal-phase content in the cubic-phase GaN buffer layer and increases with increasing the hexagonal-phase GaN content. From Raman scattering measurements, in addition, the InN layer with lowest hexagonal component (6%), only Raman characteristics of cubic TO{sub InN} and LO{sub InN} modes were observed, indicating a formation of a small amount of stacking faults, which does not affect on vibrational property.

  5. 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

  6. 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.

  7. 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

  8. A growth diagram for plasma-assisted molecular beam epitaxy of In-face InN

    SciTech Connect

    Gallinat, C. S.; Koblmueller, G.; Brown, J. S.; Speck, J. S.

    2007-09-15

    We investigated the role of temperature and In/N flux ratios to determine suitable growth windows for the plasma-assisted molecular beam epitaxy of In-face (0001) InN. Under vacuum, InN starts decomposing at 435 deg. C as defined by the release of N{sub 2} from the InN crystal and a buildup of an In adlayer and liquid In droplets on the sample surface. At temperatures greater than 470 deg. C, InN decomposition was characterized by a release of both In vapor and N{sub 2} in the absence of a significant accumulation of an In adlayer. No growth was observed at substrate temperatures above 500 deg. C or at temperatures in which the decomposition rates were higher than the growth rates. A growth diagram was then constructed consisting of two growth regimes: the 'In-droplet regime' characterized by step-flow growth and relatively flat surfaces and the ''N-rich regime'' characterized by rough, three-dimensional surfaces. The growth diagram can then be used to predict the surface structure of films grown at varying substrate temperatures and In fluxes. A 2.5 monolayer In adlayer was observed during In-droplet growth, suggesting that an In wetting layer was necessary for step-flow growth.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  11. 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

  12. Excitation-induced energy shifts in the optical gain spectra of InN quantum dots

    NASA Astrophysics Data System (ADS)

    Lorke, M.; Seebeck, J.; Gartner, P.; Jahnke, F.; Schulz, S.

    2009-08-01

    A microscopic theory for the optical absorption and gain spectra of InN quantum-dot systems is used to study the combined influence of material properties and interaction-induced effects. Atomistic tight-binding calculations for the single-particle properties of the self-assembled quantum-dot and wetting-layer system are used in conjunction with a many-body description of Coulomb interaction and carrier phonon interaction. We analyze the carrier-density and temperature dependence of strong excitation-induced energy shifts of the dipole-allowed quantum-dot transitions.

  13. 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.

  14. Defect reduction in (11-22) semipolar GaN with embedded InN islands on m-plane sapphire

    NASA Astrophysics Data System (ADS)

    Jung, Chilsung; Jang, Jongjin; Hwang, Junghwan; Jeong, Joocheol; Kim, Jinwan; Lee, kyungjae; Nam, Okhyun

    2013-05-01

    This paper reports on the improved properties of semipolar (11-22) GaN with embedded InN islands on m-plane sapphire substrate. The crystal quality of GaN grown over embedded InN islands was improved by the defect blocking mechanism that the InN islands stop from propagating of dislocations. The full width at half maximum (FWHM) of X-ray rocking curves for the on- and off-axes planes of GaN with embedded InN islands significantly narrowed. The photoluminescence (PL) intensity of GaN with embedded InN islands increased by 28% compared with that of GaN without InN islands (reference GaN). The n-type GaN carrier mobility was analyzed by using temperature-dependent Hall effect measurement. The increase in peak mobility at 350 K from 104 to 113 cm2/Vs with embedded islands also suggested the effectiveness of embedded InN islands in GaN. LEDs fabricated on (11-22) GaN with embedded InN islands showed approximately 2.7 times higher optical output power than the reference LED at 100 mA.

  15. 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…

  16. 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.

  17. 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.

  18. 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).

  19. Growth kinetics and island evolution during double-pulsed molecular beam epitaxy of InN

    NASA Astrophysics Data System (ADS)

    Kraus, A.; Hein, C.; Bremers, H.; Rossow, U.; Hangleiter, A.

    2016-06-01

    The kinetic processes of InN growth using alternating source fluxes with sub-monolayer In pulses in plasma-assisted molecular beam epitaxy have been investigated. Growth at various temperatures reveals the existence of two growth regimes. While growth at low temperatures is solely governed by surface diffusion, a combination of decomposition, desorption, and diffusion becomes decisive at growth temperatures of 470 °C and above. At this critical temperature, the surface morphology changes from a grainy structure to a structure made of huge islands. The formation of those islands is attributed to the development of an indium adlayer, which can be observed via reflection high energy electron diffraction monitoring. Based on the growth experiments conducted at temperatures below TGrowth = 470 °C, an activation energy for diffusion of 0.54 ± 0.02 eV has been determined from the decreasing InN island density. A comparison between growth on metalorganic vapor phase epitaxy GaN templates and pseudo bulk GaN indicates that step edges and dislocations are favorable nucleation sites. Based on the results, we developed a growth model, which describes the main mechanisms of the growth.

  20. Surface and bulk electronic properties of low temperature synthesized InN microcrystals

    NASA Astrophysics Data System (ADS)

    Barick, B. K.; Dhar, S.

    2015-04-01

    Structural and electronic properties of InN microcrystals, which are synthesized by nitridation of LiInO2 with NaNH2 in a Teflon-lined autoclave at temperatures ranging between 170 and 240 °C, are studied as a function of the growth temperature using x-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), photo-absorption, Raman spectroscopy and x-ray photo-emission spectroscopy (XPS) techniques. Our study shows the formation of wurtzite InN crystals with an average size of 100 nm even at 170 °C. The study, furthermore, suggests an enhancement of electron concentration and a reduction of electron mobility in the crystal as the synthesis temperature (TS) decreases. The density of certain defects lying very close to the band edge is also found to increase with the reduction of TS. These defects are expected to act as donors, which can explain the enhancement of carrier concentration as the growth temperature decreases.

  1. 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.

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

    SciTech Connect

    1980-09-01

    The solar energy hot water system installed in the Days Inns of America, Inc., Days Inn Motel (120 rooms) I-95 and Cagle Road, Jacksonville, Florida, is described. The solar system was designed by ILI, Incorporated to provide 65 percent of the hot water demand. The system is one of eleven systems planned under this grant. Water (in the Solar Energy Products, Model CU-30ww 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. This system was turned on June 19, 1979. The solar components were partly funded ($15,823 of $31,823 cost) by the Department of Energy.

  3. Solar hot water system installed at Days Inn Motel, Dallas, Texas

    SciTech Connect

    Not Available

    1980-09-01

    The solar energy hot water system installed in the Days Inn of America, Inc., Days Inn Motel (100 rooms), I-635/2753 Forrest Lane, Dallas, Texas is described. The solar system was designed by ILI, Inc., to provide 65% of the total Domestic Hot Water (DHW) demand. The liquid flat plate (water) collector is 1000 square feet of solar energy products, Model CU-30W array. Water in the collector system automatically drains into the 1000 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 up DHW tank standby losses. All pumps are controlled by differential temperature. Operation of this system was begun March 11, 1980. The solar components were partly funded ($15,000 of $30,000 cost) by the Department of Energy Grant.

  4. Solar domestic hot water system manual for Day's Inn, Garland, Texas

    SciTech Connect

    Not Available

    1981-05-01

    The solar domestic hot water system installed at Day's Inn, I-30 and 6222 Beltline, Garland, Texas is described. The system is a solar collector array used to provide from 39.9% in December, to 84.7% in August, of the domestic hot water usage of the Day's Inn in Garland, Texas. The system is an automatic draindown design employing an atmospheric vented storage tank for storing the hot water collected by the 998 sq. ft. collector array. The system's major components and features are: 44 Daystar 1400 collectors, gross square footage of 998 sq. ft.; 1000 gallon vented storage tank; 3 B and G pumps: one for the collection loop, one for transfer of energy from the thermal storage tank to the shell side of the B and G heat exchanger; the third to circulate water from the three existing DHW tanks through the tube side of the heat exchanger; 3 one-inch Taco automatic valves to control the heating of water through existing DHW tanks; vacuum breakers to ensure draindown when main circulator pump stops running; pressure gauges installed across each pump so that system flow rates can be set and read periodically as a preventive maintenance check; collector angle of 30/sup 0/.

  5. Impact of substrate nitridation on the growth of InN on In2O3(111) by plasma-assisted molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Cho, YongJin; Sadofev, Sergey; Fernández-Garrido, Sergio; Calarco, Raffaella; Riechert, Henning; Galazka, Zbigniew; Uecker, Reinhard; Brandt, Oliver

    2016-04-01

    We study the growth of InN films on In2O3(111) substrates by plasma-assisted molecular beam epitaxy under N excess. InN films deposited directly on In2O3(111) exhibit a strongly faceted morphology. A nitridation step prior to growth is found to convert the In2O3(111) surface to InN{0001}. The morphology of InN films deposited on such nitridated In2O3(111) substrates is characteristic for growth by instable step-flow and is thus drastically different from the three-dimensional growth obtained without nitridation. We show that this change originates from the different polarity of the films: while InN films deposited directly on In2O3(111) are In-polar, they are N-polar when grown on the nitridated substrate.

  6. 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

  7. 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.

  8. 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.

  9. 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}.

  10. 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.

  11. Unifying description of the optical properties of InN from first principles

    NASA Astrophysics Data System (ADS)

    Zaoui, A.; Ferhat, M.

    2009-02-01

    The optical properties of hexagonal InN have been studied using the all-electron approach based on density functional theory (DFT). The full-potential augmented plane wave method is employed with two different exchange-correlation potentials, the Perdew-Wang (PW) and the Engel-Vosko (EV) approximations. In addition, both non-relativistic and relativistic approximations are considered. We found that the PW and relativistic approximations give a metallic ground state; whereas using the EV and non-relativistic approximations a semiconductor phase is obtained, opening the gap up to 0.83 eV. Besides, the calculated interband transitions of the complex dielectric function up to 13 eV show favourable agreement with the recent spectroscopic ellipsometry results.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Role of native defects in nitrogen flux dependent carrier concentration of InN films grown by molecular beam epitaxy

    SciTech Connect

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

    2012-10-01

    We address the carrier concentration, strain, and bandgap issue of InN films grown on c-sapphire at different N-flux by molecular beam epitaxy using x-ray diffraction and x-ray photoelectron spectroscopy. We demonstrate that the strain in InN films arises due to point defects like nitrogen interstitials and nitrogen antisites. We report minimal biaxial strain due to relaxed growth morphology and a minimal hydrostatic strain arising due to interstitial nitrogen atoms being partially compensated by nitrogen antisites. We find that the variation in absorption edge can be attributed to defect induced carrier concentration and that nitrogen interstitials and nitrogen antisites act as donors that yield the respective absorption edge and Moss-Burstein shift. Our studies are a step towards the ability to form low carrier concentration strain-relaxed films and to determine the intrinsic band gap value for this technologically important material.

  17. 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.

  18. 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}.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Mass transport and alloying during InN growth on GaN by molecular-beam epitaxy

    SciTech Connect

    Liu, Y.; Xie, M.H.; Wu, H.S.; Tong, S.Y.

    2006-05-29

    During Stranski-Krastanov (SK) growth of InN on GaN by molecular-beam epitaxy, a mass transport is noted from the two-dimensional wetting layer and/or the surface excess metal adlayers to the SK islands when the excess nitrogen flux is used for deposition. The extent of mass transport depends on the material coverage. For growth under the excess indium flux condition, no such mass transport is observed.

  4. 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.

  5. Excitation dependent Raman studies of self-seeded grown InN nanoparticles with different carrier concentration.

    PubMed

    Madapu, Kishore K; Polaki, S R; Dhara, Sandip

    2016-07-21

    High quality InN nanoparticles are grown using an atmospheric chemical vapour deposition technique via a self-seeded catalytic approach in the temperature range of 580-650 °C. In this temperature region, the nucleation barrier of InN is overcome by seeding low density In nanoparticles prior to introduction of reactive NH3. Samples with increasing carrier densities are grown, with the help of increasing growth temperature, to understand the role of carrier density in the optical phonon structure. Near-resonance Raman spectra show completely different phonon pictures compared to those for the off-resonance spectra. A Raman forbidden mode of B1(high), because of the possible breakdown of selection rules in the near-resonance conditions, is invoked for the first time. The intensity and frequency of this mode strongly depend on the carrier concentration in the sample. In off-resonance conditions, the A1(LO) mode for the sample with higher carrier concentration is dominated by Fano interference rather than plasmon-phonon coupling. Variation of the intensity of the B1(high) mode is correlated with a band filling effect, which is substantiated by the luminescence studies of the InN samples with different carrier concentrations. PMID:27345503

  6. 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.

  7. A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs

    PubMed Central

    Kao, Kun-Wei; Hsu, Ming-Che; Chang, Yuh-Hwa; Gwo, Shangjr; Yeh, J. Andrew

    2012-01-01

    An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensitivity due to its strong electron accumulation on roughly 5–10 nm deep layers from the surface. Platinum as catalyst can increase output current signals by 2.5-fold (94 vs. 37.5 μA) as well as reduce response time by 8.4-fold (150 vs. 1,260 s) in comparison with bare InN. More, the effect of 3% oxygen consumption due to breath inhalation and exhalation on 2.4 ppm acetone gas detection was investigated, indicating that such an acetone concentration can be analyzed in air. PMID:22969342

  8. Morphology and arrangement of InN nanocolumns deposited by radio-frequency sputtering: Effect of the buffer layer

    NASA Astrophysics Data System (ADS)

    Monteagudo-Lerma, L.; Valdueza-Felip, S.; Núñez-Cascajero, A.; Ruiz, A.; González-Herráez, M.; Monroy, E.; Naranjo, F. B.

    2016-01-01

    We present the structural and optical properties of (0001)-oriented nanocolumnar films of InN deposited on c-sapphire substrates by radio-frequency reactive sputtering. It is observed that the column density and dimensions are highly dependent on the growth parameters of the buffer layer. We investigate four buffer layers consisting of (i) 30 nm of low-growth-rate InN, (ii) 30 nm of AlN deposited on the unbiased substrate (us), (iii) 30 nm of AlN deposited on the reverse-biased substrate (bs), and (iv) a 60-nm-thick bilayer consisting of 30-nm-thick bs-AlN deposited on top of 30-nm-thick us-AlN. Differences in the layer nucleation process due to the buffer layer induce variations of the column density in the range of (2.5-16)×109 cm-2, and of the column diameter in the range of 87-176 nm. Best results in terms of mosaicity are obtained using the bs-AlN buffer layer, which leads to a full width at half-maximum of the InN(0002) rocking curve of 1.2°. A residual compressive strain is still present in the nanocolumns. All samples exhibit room temperature photoluminescence emission at ~1.6 eV, and an apparent optical band gap at ~1.7 eV estimated from linear optical transmittance measurements.

  9. 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.

  10. 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.

  11. An investigation into the conversion of In2O3 into InN nanowires

    PubMed Central

    2011-01-01

    Straight In2O3 nanowires (NWs) with diameters of 50 nm and lengths ≥2 μm have been grown on Si(001) via the wet oxidation of In at 850°C using Au as a catalyst. These exhibited clear peaks in the X-ray diffraction corresponding to the body centred cubic crystal structure of In2O3 while the photoluminescence (PL) spectrum at 300 K consisted of two broad peaks, centred around 400 and 550 nm. The post-growth nitridation of In2O3 NWs was systematically investigated by varying the nitridation temperature between 500 and 900°C, flow of NH3 and nitridation times between 1 and 6 h. The NWs are eliminated above 600°C while long nitridation times at 500 and 600°C did not result into the efficient conversion of In2O3 to InN. We find that the nitridation of In2O3 is effective by using NH3 and H2 or a two-step temperature nitridation process using just NH3 and slower ramp rates. We discuss the nitridation mechanism and its effect on the PL. PMID:21711836

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Superfund record of decision (EPA Region 4): Beaunit Circular Knit and Dyeing, Greenville County, Fountain Inn, SC, September 29, 1995

    SciTech Connect

    1996-03-01

    This decision document presents the selected remedial action for the Beaunit Circular Knit and Dying Superfund Site (the Site) in Fountain Inn, South Carolina. The major components of the selected remedy include: containment of soils and sediments contaminated with volatile organic compounds (VOCs) and metals by capping of the lagoon area; and additional monitoring of groundwater and soils on a regular schedule to determine effects of construction of lagoon cap, and to insure effectiveness of cap after construction. Modifications to the frequency or termination of continued monitoring will be determined during the Remedial Action and the Five Year Review.

  18. Raman and transmission electron microscopy characterization of InN samples grown on GaN/Al2O3 by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Arvanitidis, J.; Katsikini, M.; Ves, S.; Delimitis, A.; Kehagias, Th.; Komninou, Ph.; Dimakis, E.; Iliopoulos, E.; Georgakilas, A.

    Raman spectroscopy and transmission electron microscopy were employed to study the vibrational properties and the microstructure of epitaxially grown InN films on GaN/Al2O3 templates. The variations of the InN lattice constants, as deduced by electron diffraction analysis, along with the red-shifted E22 mode frequency reveal that InN films exhibit residual tensile stress, strongly dependent on the epilayer growth temperature. Threading dislocations are the dominant structural defects in the films, having a density in the order of 109-1010 cm-2. Profile analysis of the E22 Raman peak by means of the Spatial Correlation Model provides useful information concerning the effective mean length for free phonon propagation (L), which is a measure of the structural quality of the samples. In all the studied samples, L monotonically increases with decreasing threading dislocation density of pure screw and mixed type character.

  19. 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.

  20. High-rate growth of InN films on fianite and sapphire substrates by metalorganic vapor phase epitaxy with plasma-assisted nitrogen activation

    NASA Astrophysics Data System (ADS)

    Buzynin, Yu. N.; Vodop'yanov, A. V.; Golubev, S. V.; Drozdov, M. N.; Drozdov, Yu. N.; Luk'yanov, A. Yu.; Mansfeld, D. A.; Khrykin, O. I.; Shashkin, V. I.; Yunin, P. A.

    2015-03-01

    Hexagonal single-crystalline indium nitride (InN) films on (0001)-oriented sapphire (Al2O3) and (111)-oriented fianite (yttria-stabilized zirconia, YSZ) substrates and on (0001)-oriented GaN/Al2O3 templates have been grown at a record high rate of 10 μm/h by the method of metalorganic vapor phase epitaxy with nitrogen activation in plasma of electron cyclotron resonance discharge generated by gyrotron radiation. It is established that the use of fianite substrates significantly improves the structural perfection and photoluminescent properties of InN films as compared to those grown on sapphire and templates. Undoped InN films exhibit n-type conductivity with electron concentrations within n = 8.0 × 1019-4.9 × 1020 cm-3 and room-temperature mobilities up to 180 cm2/(V s).

  1. Optical and structural characterization of nitrogen-rich InN: Transition from nearly intrinsic to strongly n-type degenerate with temperature

    SciTech Connect

    Hong Tran, Nhung; Huy Le, Binh; Fan, Shizhao; Zhao, Songrui; Mi, Zetian; Schmidt, Benjamin A.; Savard, Michel; Gervais, Guillaume; Butcher, Kenneth Scott A.

    2013-12-23

    We report on a detailed study of the structural and optical properties of nonstoichiometric nitrogen-rich InN grown on sapphire substrates, by migration enhanced afterglow deposition. The samples were polycrystalline, with the presence of InN dots. Unusually strong photoluminescence emission was measured at cryogenic temperatures, with the peak energy at ∼0.68 eV. Detailed analysis further shows that the sample has very low residual electron density in the range of ∼10{sup 16} cm{sup −3} at temperatures below 20 K.

  2. Phase mapping of aging process in InN nanostructures: oxygen incorporation and the role of the zinc blende phase

    NASA Astrophysics Data System (ADS)

    González, D.; Lozano, J. G.; Herrera, M.; Morales, F. M.; Ruffenach, S.; Briot, O.; García, R.

    2010-05-01

    Uncapped InN nanostructures undergo a deleterious natural aging process at ambient conditions by oxygen incorporation. The phases involved in this process and their localization is mapped by transmission electron microscopy (TEM)-related techniques. The parent wurtzite InN (InN-w) phase disappears from the surface and gradually forms a highly textured cubic layer that completely wraps up a InN-w nucleus which still remains from the original single-crystalline quantum dots. The good reticular relationships between the different crystals generate low misfit strains and explain the apparent easiness for phase transformations at room temperature and pressure conditions, but also disable the classical methods to identify phases and grains from TEM images. The application of the geometrical phase algorithm in order to form numerical moiré mappings and RGB multilayered image reconstructions allows us to discern among the different phases and grains formed inside these nanostructures. Samples aged for shorter times reveal the presence of metastable InN:O zinc blende (zb) volumes, which act as the intermediate phase between the initial InN-w and the most stable cubic In2O3 end phase. These cubic phases are highly twinned with a proportion of 50:50 between both orientations. We suggest that the existence of the intermediate InN:O-zb phase should be seriously considered to understand the reason for the widely scattered reported fundamental properties of thought to be InN-w, as its bandgap or superconductivity.

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

    NASA Astrophysics Data System (ADS)

    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

    2016-05-01

    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.

  4. 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. PMID:27041669

  5. 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.

  6. Doping effects of C, Si and Ge in wurtzite [0001] GaN, AlN, and InN nanowires

    NASA Astrophysics Data System (ADS)

    Colussi, M. L.; Baierle, R. J.; Miwa, R. H.

    2011-08-01

    We have performed an ab initio investigation, within the spin-polarized density functional theory, of the energetic stability and electronic properties of substitutional Si, Ge, and C impurities in [0001] GaN, AlN, and InN nanowires (NWs). Our total energy results show that C impurities in the cation site (CGa, CAl, and CIn) present lower formation energies at the surface of the NWs as compared to their counterparts in the core of the NW or the bulk system. In these position donor likely properties are obtained for GaN and InN NWs, whereas for the AlN NW deep levels are observed inside the bandgap. In contrast, CN must be distributed uniformly along the NW diameter and gives rise to a deep electronic level inside the NW bandgap. Si in GaN and InN and Ge in InN are most stable at the cation site in the core of the NWs, and lead the systems to show a n-type semiconductor properties. For the AlN NW we obtain that Si and Ge are most likely in a N site at the surface of the NW and introduce deep levels inside the NW bandgap. Meanwhile, C and Ge impurities are amphoteric impurities in GaN NWs.

  7. 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.

  8. 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

  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. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  18. 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.

  19. 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.

  20. Enhanced Light Scattering of the Forbidden longitudinal Optical Phonon Mode Studied by Micro-Raman Spectroscopy on Single InN nanowires

    SciTech Connect

    Sutter, E.; Schafer-Nolte, E.O.; Stoica T.; Gotschke, T.; Limbach, F.A.; Sutter, P.; Grutzmacher, D.; Calarco, R.

    2010-08-06

    In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E2 phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

  1. 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.

  2. 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.

  3. 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.

  4. An Overview of the Geological and Geotechnical Aspects of the New Railway Line in the Lower Inn Valley

    NASA Astrophysics Data System (ADS)

    Eder, Stefan; Poscher, Gerhard; Sedlacek, Christoph

    The new railway line in the lower Inn-valley is part of the Brenner railway axis from Munich to Verona (feeder north). The first section between the villages of Kundl and Radfeld, west of Wörgl, and the village of Baumkirchen, east of Innsbruck, will become one of the biggest infrastructure projects ever built in Austria, with a length of approx. 43 km and an underground portion of approx. 80%. The article gives an overview of the various geologic formations - hard rock sections in the valley slopes, different water-saturated gravel and sand formations in the valley floor and geotechnically difficult conditions in sediments of Quaternary terraces. It also describes the methodology of the soil reconnaissance using groundwater models for hydrogeologic estimations, core drillings for evaluating geologic models and describes the experiences gained from the five approx. 7.5 km long reconnaissance tunnels for geotechnical and hydrogeological testing. The results of the soil reconnaissance were used to plan different construction methods, such as excavation in soft rock under a jet grouting roof and compressed-air, as well as mechanised shield with fluid support.

  5. Post-growth thermal oxidation of wurtzite InN thin films into body-center cubic In{sub 2}O{sub 3} for chemical/gas sensing applications

    SciTech Connect

    Liu, H.F.; Yakovlev, N.L.; Chi, D.Z.; Liu, W.

    2014-06-01

    Post-growth thermal oxidations of InN have been studied using high-resolution x-ray diffraction (HRXRD) and secondary ion-mass spectroscopy (SIMS). The InN thin films, having relative high crystal quality, were grown by metal–organic chemical vapor deposition (MOCVD) on c-sapphire substrates using InGaN/GaN buffer layers. HRXRD reveals that oxidation of wurtzite InN into body-center cubic In{sub 2}O{sub 3} occurred at elevated temperatures. A Si{sub 3}N{sub 4} encapsulation improves the crystal quality of In{sub 2}O{sub 3} oxidized by using conventional rapid thermal annealing (RTA) but it results in the presence of undesired metallic indium. Cycle-RTA not only improves the crystal quality but also avoids the byproduct of metallic indium. SIMS depth profile, using contaminate elements as the ‘interface markers,’ provide evidence that the oxidation of InN is dominated by oxygen inward diffusion mechanism. Together with the HRXRD results, we conclude that the crystal quality of the resultant In{sub 2}O{sub 3}/InN heterostructure is mainly controlled by the balance between the speeds of oxygen diffusion and InN thermal dissociation, which can be effectively tuned by cycle-RTA. The obtained In{sub 2}O{sub 3}/InN heterostructures can be fundamental materials for studying high speed chemical/gas sensing devices. - Graphical abstract: Oxidation of h-InN into bcc-In{sub 2}O{sub 3} has been realized at elevated temperatures. A Si{sub 3}N{sub 4} cap improves the crystal quality of In{sub 2}O{sub 3} oxidized by conventional RTA but it results in the presence of undesired metallic indium. Cycle-RTA not only improves the crystal quality but also avoids the byproduct of metallic indium. SIMS depth profiles provide evidence that the oxidation of InN is dominated by oxygen inward diffusion mechanism. The crystal quality of the resultant In{sub 2}O{sub 3}/InN heterostructure is mainly controlled by the balance between the speeds of oxygen diffusion and InN thermal

  6. A model for the spectral blueshift caused by the In-N clusters in InxGa1-xNyAs1-y (x<0.4 and y≤0.04) after annealing

    NASA Astrophysics Data System (ADS)

    Zhao, Chuan-Zhen; Li, Na-Na; Wei, Tong; Wang, Sha-Sha; Lu, Ke-Qing

    2013-07-01

    A model describing the spectral blueshift of the quaternary alloy InxGa1-xNyAs1-y (x<0.4 and y≤0.04) caused by the In-N clusters after annealing is developed by modifying the band-anticrossing (BAC) model. In the modified BAC model, we consider the effect of the added In-N clusters after annealing on the parameters in the band anticrossing model. It is found that the variation of the N level can be considered to be proportional to the variation of the average number of the nearest-neighbor In atoms per N atom, and the variation of the coupling interaction between the N level and the Γ conduction band is determined by the added In-N bonds and the In content. The obtained results are in agreement well with the experimental data. It is very helpful to explain the essence of the blueshift caused by annealing.

  7. Dislocation and Elastic Strain in an InN Film Characterized by Synchrotron Radiation X-Ray Diffraction and Rutherford Backscattering/Channeling

    NASA Astrophysics Data System (ADS)

    Cheng, Feng-Feng; Fa, Tao; Wang, Xin-Qiang; Yao, Shu-De

    2012-02-01

    Dislocation information and strain-related tetragonal distortion as well as crystalline qualities of a 2-μm-thick InN film grown by molecular beam epitaxy (MBE) are characterized by Rutherford backscattering/channeling (RBS/C) and synchrotron radiation x-ray diffraction (SR-XRD). The minimum yield χmin = 2.5% deduced from the RBS/C results indicates a fairly good crystalline quality. From the SR-XRD results, we obtain the values of the screw and edge densities to be ρscrew = 7.0027 × 109 and ρedge = 8.6115 × 109 cm-2, respectively. The tetragonal distortion of the sample is found to be -0.27% by angular scans, which is close to the -0.28% derived by SR-XRD. The value of |e⊥/e∥| = 0.6742 implies that the InN layer is much stiffer along the a axis than that along the c axis, where e∥ is the parallel elastic strain, and e⊥ is the perpendicular elastic strain. Photoluminescence results reveal a main peak of 0.653 eV with the linewidth of 60 meV, additional shoulder band could be due to impurities and related defects.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Hybrid functional investigations of band gaps and band alignments for AlN, GaN, InN, and InGaN.

    PubMed

    Moses, Poul Georg; Miao, Maosheng; Yan, Qimin; Van de Walle, Chris G

    2011-02-28

    Band gaps and band alignments for AlN, GaN, InN, and InGaN alloys are investigated using density functional theory with the with the Heyd-Scuseria-Ernzerhof {HSE06 [J. Heyd, G. E. Scuseria, and M. Ernzerhof, J. Chem. Phys. 134, 8207 (2003); 124, 219906 (2006)]} XC functional. The band gap of InGaN alloys as a function of In content is calculated and a strong bowing at low In content is found, described by bowing parameters 2.29 eV at 6.25% and 1.79 eV at 12.5%, indicating the band gap cannot be described by a single composition-independent bowing parameter. Valence-band maxima (VBM) and conduction-band minima (CBM) are aligned by combining bulk calculations with surface calculations for nonpolar surfaces. The influence of surface termination [(1100) m-plane or (1120) a-plane] is thoroughly investigated. We find that for the relaxed surfaces of the binary nitrides the difference in electron affinities between m- and a-plane is less than 0.1 eV. The absolute electron affinities are found to strongly depend on the choice of XC functional. However, we find that relative alignments are less sensitive to the choice of XC functional. In particular, we find that relative alignments may be calculated based on Perdew-Becke-Ernzerhof [J. P. Perdew, K. Burke, and M. Ernzerhof, Phys. Rev. Lett. 134, 3865 (1996)] surface calculations with the HSE06 lattice parameters. For InGaN we find that the VBM is a linear function of In content and that the majority of the band-gap bowing is located in the CBM. Based on the calculated electron affinities we predict that InGaN will be suited for water splitting up to 50% In content. PMID:21361552

  13. Hybrid functional investigations of band gaps and band alignments for AIN, GaN, InN, and InGaN

    SciTech Connect

    Moses, Poul George; Miao, M. S.; Yan, Qimin; Van de Walle, Chris G.

    2011-01-01

    Band gaps and band alignments for AlN,GaN, InN, and InGaN alloys are investigated using density functional theory with the with the Heyd–Scuseria–Ernzerhof {HSE06 [J. Heyd, G. E. Scuseria, and M. Ernzerhof, J. Chem. Phys.134, 8207 (2003)10.1063/1.3548872; 124, 219906 (2006)]} XC functional. The band gap of InGaN alloys as a function of In content is calculated and a strong bowing at low In content is found, described by bowing parameters 2.29 eV at 6.25% and 1.79 eV at 12.5%, indicating the band gap cannot be described by a single composition-independent bowing parameter. Valence-band maxima (VBM) and conduction-band minima (CBM) are aligned by combining bulk calculations with surface calculations for nonpolar surfaces. The influence of surface termination [(1{bar 1}00) m-plane or (11{bar 20) a-plane] is thoroughly investigated. We find that for the relaxed surfaces of the binary nitrides the difference in electron affinities between m- and a-plane is less than 0.1 eV. The absolute electron affinities are found to strongly depend on the choice of XC functional. However, we find that relative alignments are less sensitive to the choice of XC functional. In particular, we find that relative alignments may be calculated based on Perdew–Becke–Ernzerhof [J. P. Perdew, K. Burke, and M. Ernzerhof, Phys. Rev. Lett.134, 3865 (1996)] surface calculations with the HSE06 lattice parameters. For InGaN we find that the VBM is a linear function of In content and that the majority of the band-gap bowing is located in the CBM. Based on the calculated electron affinities we predict that InGaN will be suited for water splitting up to 50% In content.

  14. Nature and origin of V-defects present in metalorganic vapor phase epitaxy-grown (InxAl1-x)N layers as a function of InN content, layer thickness and growth parameters

    NASA Astrophysics Data System (ADS)

    Vennéguès, P.; Diaby, B. S.; Kim-Chauveau, H.; Bodiou, L.; Schenk, H. P. D.; Frayssinet, E.; Martin, R. W.; Watson, I. M.

    2012-08-01

    Our study of samples grown in different metalorganic chemical vapor deposition reactors and with different growth conditions reveals that V-pits are always present in (InxAl1-x)N films whatever the layer thickness and the InN content. V-pits are empty inverted pyramids terminating threading dislocations. InN-rich triangular regions are present around the threading dislocations terminated by pits with a hexagonal 6-fold symmetry distribution in {11-20} planes. The nature of the facets of the V-pits depends on the growth conditions: pits with either {11-2l}, l being between 1 and 3, or {1-101} facets have been observed. Moreover, the nature of the threading dislocations terminated by pits also depends on the growth conditions. Our observations suggest that with a high V/III ratio only edge a+c-type dislocations are terminated by pits whereas with a low V/III ratio both edge a-type and mixed a+c-type dislocations are terminated by pits.

  15. 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 …

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

    MedlinePlus

    ... Kristal is currently studying to become a certified school nurse. "I identify with others who must overcome adversity," ... with their own adversities. I love being a school nurse and helping children be successful in the school ...

  17. 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…

  18. High pressure structural, electronic and vibrational properties of InN and InP

    NASA Astrophysics Data System (ADS)

    Panchal, J. M.; Joshi, Mitesh; Gajjar, P. N.

    2016-03-01

    A first-principles plane wave self-consistent method with the Ultrasoftpseudopotential scheme in the framework of density functional theory is performed to study the high pressure structural, electronic and vibrational properties of InX (X = N, P) for the zinc-blende (ZnS/B3), rock-salt (NaCl/B1) and cesium-chloride (CsCl/B2) phases. We also calculate the phase transition pressures among these different phases. Conclusions based on electronic energy band structure, phonon dispersion and phonon density of states at high pressure phases along phase transition regions are outlined.

  19. Materials Data on InN (SG:186) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. 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,…

  1. INN: An Intelligent Negotiating Neural Network for Information Systems: A Design Model.

    ERIC Educational Resources Information Center

    Meghabghab, George V.; Meghabghab, Dania B.

    1994-01-01

    Presents an Intelligent Negotiating Neural Network Design Model for solving the problem of poor information retrieval in subject searches of online catalogs. The purpose of the network, its architecture, and three different sessions of the user interface are described. Nineteen figures showing screens of the three sessions are appended. (Contains…

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Project EXCEL: Holiday Inn at Union Square, Housekeeping Department. Safety and Security, Module 2.

    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,…

  7. 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…

  8. 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.

  9. 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.

  10. Materials Data on Ti3InN (SG:221) by Materials Project

    SciTech Connect

    Kristin Persson

    2015-02-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Formal collaboration between John Innes Pisum collection and USDA-ARS collection over Pisum genetic stocks.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA genetic stock collection is incomplete, only 101 genes (mutations) are represented with no alleles from another 246 published pea genes represented in the collection. This germplasm is desired for pea breeding programs for crop improvement through fundamental studies on pea functional geno...

  12. 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…

  13. 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)

  14. 75 FR 59276 - National Heart, Lung, and Blood Institute; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-27

    ... grant applications. Place: Doubletree Hotel Bethesda (Formerly Holiday Inn Select), 8120 Wisconsin... Holiday Inn Select), 8120 Wisconsin Avenue, Bethesda, MD 20814. Contact Person: Holly K. Krull,...

  15. 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.

  16. 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

  17. American Headache Society

    MedlinePlus

    ... Marriott Camelback Inn READ MORE Jan 20 2017 International Headache Academy Los Angeles, CA , UCLA Meyer & Renee ... Symposium JW Marriott Camelback Inn Jan 20 2017 International Headache Academy UCLA Meyer & Renee Luskin Conference Center ...

  18. 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

  19. 78 FR 29757 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ...: Hilton Garden Inn Washington DC/Bethesda, 7301 Waverly Street, Bethesda, MD 20814. Contact Person.... Place: Hilton Garden Inn Washington DC/Bethesda, 7301 Waverly Street, Bethesda, MD 20814. Contact...

  20. 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...

  1. Ionic nanoparticle networks: development and perspectives in the landscape of ionic liquid based materials.

    PubMed

    Neouze, Marie-Alexandra; Kronstein, Martin; Tielens, Frederik

    2014-09-28

    This feature article gives an overview of the research performed on ionic nanoparticle networks (INNs). These INNs are hybrid materials consisting of inorganic nanoparticles and ionic linkers, such as imidazolium, bisimidazolium or pyridinium. The synthesis and properties of INNs, for catalysis or sensorics, are presented. At each step INN materials are compared to other hybrid materials of similar composition such as ionogels or suspensions of imidazolium modified nanoparticles. PMID:24968952

  2. 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.

  3. 75 FR 54386 - Southeast Oregon Resource Advisory Council; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-07

    ... Holiday Inn Express, 212 SE 10th St. Ontario, OR 97914 at the above time. The business meeting will meet at the Holiday Inn Express Conference Room, 212 SE 10th St. Ontario, OR 97914. FOR FURTHER... the Holiday Inn Express Conference Room, 212 SE. 10th St., Ontario, OR 97914 from 8 a.m. to 4 p.m....

  4. 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.

  5. 75 FR 39546 - National Cancer Institute; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-09

    ... applications. Place: Bethesda North Marriott Hotel, 5701 Marinelli Road, North Bethesda, MD 20852. Contact...: Doubletree Hotel Bethesda, (Formerly Holiday Inn Select) 8120 Wisconsin Avenue, Bethesda, MD 20814....

  6. 78 FR 29374 - National Institute of Environmental Health Sciences Amended; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ...., Hilton Garden Inn Durham Southpoint Hotel, 7007 Fayetteville Road, Durham, NC 27713 which was published in the Federal Register on May 8, 2013, 78 FR 89. The meeting notice is amended to change the date of... Garden Inn Durham Southpoint Hotel to the DoubleTree by Hilton Hotel. The meeting is closed to the...

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 76 FR 28846 - Requested Administrative Waiver of the Coastwise Trade Laws

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ....S.C. 12121 and MARAD's regulations at 46 CFR part 388 (68 FR 23084, April 30, 2003), that the... for our Old Manse Inn guest in conjunction with staying at our 1801 Sea Captains Manor 12 room facility. The intent is increasing our Inn occupancy rates and exposure. Berthed at Chatham's Stage...

  13. Irreversible thermochromism in copper chloride Imidazolium Nanoparticle Networks.

    PubMed

    Kronstein, Martin; Kriechbaum, Konstantin; Akbarzadeh, Johanna; Peterlik, Herwig; Neouze, Marie-Alexandra

    2013-08-14

    In this work Imidazolium Nanoparticle Networks (INNs) with chloride counter-ions were used to complex copper dichloride. This complexation reaction leads to the formation of a green material. The properties of the copper INN material were compared to: first, copper imidazolium complexes, without the presence of silica nanoparticles, which are not thermochromic; second, chloride-containing INN material. The copper INN material showed irreversible thermochromic behaviour, with a clear colour change from green to yellow at 180 °C, which is due to a configuration change of the copper complex from planar to tetragonal. This structural change was studied using DSC and in situ SAXS measurements during heat treatment. The thermochromic material is stable under air up to 250 °C. This preliminary study opens the door of optical sensors for INN materials. PMID:23793383

  14. 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

  15. 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

  16. 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

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

    PubMed Central

    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.

    2011-01-01

    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. PMID:22101818

  18. 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

  19. 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

  20. 1994 UPDATE OF U.S. EPA'S SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION (SITE) EMERGING TECHNOLOGY PROGRAM

    EPA Science Inventory

    The U.S. Environmental Protection Agency's (EPA) Superfund Innovative Technology Evaluation (SITE), Emerging Technology Partnership (ETP) has initiated actions since 1987 that support the Clinton Administration's policy to foster and accelerate the research and development of inn...

  1. Carrier multiplication in bulk indium nitride

    NASA Astrophysics Data System (ADS)

    Jensen, S. A.; Versluis, J.; Cánovas, E.; Pijpers, J. J. H.; Sellers, I. R.; Bonn, M.

    2012-11-01

    Carrier multiplication (CM) is the process of generating multiple electron-hole pairs from one absorbed photon. Narrow-gap InN is a material that has been proposed for achieving efficient CM. We quantify the CM efficiency in bulk InN using terahertz time-domain spectroscopy. While the CM onset occurs at relatively low photon energies in InN (1.7 ± 0.2 eV), corresponding to 2.7 ± 0.3 times its bandgap, the excitation efficiency above the onset increases linearly with a slope of only ˜13%/Eg. Based on these numbers, the efficiency increase of an InN based photovoltaic device owing to CM is limited to maximum 1% point.

  2. 77 FR 28612 - National Cancer Institute; Amended Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ..., Alexandria, VA 22314 which was published in the Federal Register on March 29, 2012, 77 FR 19024. This notice is being amended to change the location to ``The Residence Inn Old Town Alexandria, 1456 Duke...

  3. MEG source localization using invariance of noise space.

    PubMed

    Zhang, Junpeng; Raij, Tommi; Hämäläinen, Matti; Yao, Dezhong

    2013-01-01

    We propose INvariance of Noise (INN) space as a novel method for source localization of magnetoencephalography (MEG) data. The method is based on the fact that modulations of source strengths across time change the energy in signal subspace but leave the noise subspace invariant. We compare INN with classical MUSIC, RAP-MUSIC, and beamformer approaches using simulated data while varying signal-to-noise ratios as well as distance and temporal correlation between two sources. We also demonstrate the utility of INN with actual auditory evoked MEG responses in eight subjects. In all cases, INN performed well, especially when the sources were closely spaced, highly correlated, or one source was considerably stronger than the other. PMID:23505502

  4. 78 FR 5468 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-25

    ... grant applications. Place: Holiday Inn Inner Harbor, 301 W. Lombard Street, Baltimore, MD 21201. Contact... Drake Hotel, 450 Powell Street at Sutter, San Francisco, CA 94102. Contact Person: Yi-Hsin Liu,...

  5. 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

  6. 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 ...

  7. 75 FR 77901 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ... Mercer County Delaware Inn, 1030 Lamberton St, Trenton, 10001109 NORTH CAROLINA Franklin County Perry... Carolina, 1945-1965), Bounded roughly by King Charles Rd, Poole Rd, Donald Ross Dr, Albemarle Ave,...

  8. 18. 'Petite Cuisine' room, view east. Window at left also ...

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

    18. 'Petite Cuisine' room, view east. Window at left also shown in exterior photo HABS-CA-26121-B-8. - Deetjen's Big Sur Inn, Hayloft Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  9. 78 FR 66028 - Center for Scientific Review; Amended Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ..., (Formerly Holiday Inn Select), 8120 Wisconsin Avenue, Bethesda, MD, 20814 which was published in the Federal Register on September 10, 2013, 78 FR 55267. The meeting will be held at the National Institutes of...

  10. 78 FR 64516 - Center for Scientific Review; Amended Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ..., (Formerly Holiday Inn Select), 8120 Wisconsin Avenue, Bethesda, MD, 20814 which was published in the Federal Register on September 17, 2013, 78 FR Pgs. 57168-57169. The meeting will start on November 19, 2013 at...

  11. 75 FR 69451 - National Institute of Dental & Craniofacial Research; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... and performance, and the competence of individual investigators, the disclosure of which would..., and competence of individual investigators. Place: Doubletree Hotel Bethesda (Formerly Holiday Inn... review and evaluate personal qualifications and performance, and competence of individual...

  12. 75 FR 17897 - Siskiyou County Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-08

    ... of meeting. SUMMARY: The Siskiyou County Resource Advisory Committee (RAC) will meet in Yreka... meeting will be held at the Yreka Holiday Inn Express Conference Center, 707 Montague Road, Yreka,...

  13. 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

  14. 1. GENERAL VIEW, LOOKING SOUTHWEST. AT RIGHT IS A REPUTED ...

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

    1. GENERAL VIEW, LOOKING SOUTHWEST. AT RIGHT IS A REPUTED LOCK TENDER'S HOUSE AND INN, UNDERGOING RESTORATION AS PART OF THE CUYAHOGA VALLEY NATIONAL RECREATION AREA - Ohio & Erie Canal, Lock No. 38, Canal & Hillside Roads, Valley View, Cuyahoga County, OH

  15. 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.

  16. 76 FR 14685 - Notice of Meetings, Front Range Resource Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... available at: http://www.blm.gov/rac/co/frrac/co_fr.htm . Dated: March 9, 2011. Helen M. Hankins, State..., 3028 East Main Street, Canon City, CO. ] 2. July 20, 2011; Hampton Inn, 710 Mariposa St., Alamosa,...

  17. 76 FR 24481 - National Advisory Council for Environmental Policy and Technology

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ..., industry, non-governmental organizations, and local, State, and tribal governments. The purpose of this.... ADDRESSES: The meeting will be held at the Hilton Garden Inn Washington Hotel, 815 14th Street...

  18. Felty syndrome

    MedlinePlus

    ... www.ncbi.nlm.nih.gov/pubmed/9209836 . Sweeney SE, Harris ED, Firestein GS. Clinical features of rheumatoid arthritis. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelley's Textbook ...

  19. Making everyday tasks easier - arthritis

    MedlinePlus

    ... of osteoarthritis. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook ... Philadelphia, PA: Elsevier Saunders; 2013:chap 99. Sweeney SE, Harris ED, Firestein GS. Clinical features of rheumatoid ...

  20. 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

  1. 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

  2. 78 FR 735 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-04

    ... evaluate grant applications. Place: Courtyard Long Beach, 500 East First Street, Long Beach, CA 90802...: Admiral Fell Inn, 888 South Broadway, Baltimore, MD 21231. Contact Person: George M Barnas,...

  3. Solar hot water system installed at Las Vegas, Nevada. Final report

    SciTech Connect

    1981-01-01

    The solar hot water system installed at LaQuinta Motor Inn Inc., 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 1200 square feet of liquid flat plate collectors, a 2500 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  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. 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.

  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. Observation of visible luminescence from indium nitride at room temperature

    SciTech Connect

    Guo, Q.X.; Tanaka, T.; Nishio, M.; Ogawa, H.; Pu, X.D.; Shen, W.Z.

    2005-06-06

    InN films were grown on sapphire substrates with AlN buffer layers by reactive sputtering. C-axis-oriented crystalline InN films with a wurtzite structure were confirmed by x-ray diffraction and Raman scattering. Strong photoluminescence (PL) at 1.87 eV, together with a clear absorption edge at 1.97 eV, was observed at room temperature, which clearly demonstrates that it is not accurate in the previous assignment of an {approx}0.7 eV fundamental band gap for intrinsic InN simply from PL and absorption data. The possible origin of the present large band gap was discussed in terms of the effects of oxygen and the Burstein-Moss shift.

  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. 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.

  16. 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.

  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. 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.

  20. 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…

  1. THE NOVEL, THE ONE-ACT PLAY, NONSTORIED FORMS--LITERATURE CURRICULUM II, STUDENT VERSION.

    ERIC Educational Resources Information Center

    KITZHABER, ALBERT

    A GUIDE FOR STUDENT USE WAS PREPARED FOR AN EIGHTH-GRADE LANGUAGE CURRICULUM. THE GUIDE INCLUDED STUDIES OF CHAPTERS FROM, "THE CALL OF THE WILD," AND "THE PEARL," AND THE STUDY OF ONE-ACT PLAYS ("A NIGHT AT AN INN," AND "TRIFLES,") IN ADDITION TO UNITS OF STUDY ON LITERATURE FORM INVOLVING EITHER DEFINITION, EXAMPLE, COMPARISON, OR CONTRAST.…

  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. 78 FR 66372 - Center for Scientific Review; Amended Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    ... Register on September 12, 2013, 78 FR 56239. The meeting will be held at the Residence Inn Capital View... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Center for Scientific Review; Amended Notice of...

  4. 50 CFR 32.39 - Maryland.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Migratory Game Bird Hunting. We allow hunting of goose and duck on designated areas of the refuge in... Boxes Point and Duck Inn Trails only during daylight hours. 4. We require you to possess a valid... Refuge A. Migratory Game Bird Hunting. We allow hunting of goose, duck, and dove on the North Tract...

  5. 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…

  6. 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.

  7. 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…

  8. 75 FR 6435 - Sunshine Act Meeting Notice

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... From the Federal Register Online via the Government Publishing Office TENNESSEE VALLEY AUTHORITY Sunshine Act Meeting Notice The TVA Board of Directors will hold a public meeting on February 11, 2010, at the Holiday Inn Hotel and Suites, Bristol Convention Center, Ballrooms B/C, 3005 Linden Drive,...

  9. 78 FR 68134 - Sunshine Act Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ... From the Federal Register Online via the Government Publishing Office TENNESSEE VALLEY AUTHORITY Sunshine Act Meeting The TVA Board of Directors will hold a public meeting on November 14, 2013, at The Inn at Ole Miss, Oxford, Mississippi. The public may comment on any agenda item or subject at a...

  10. 77 FR 24555 - Sunshine Act Meeting Notice

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-24

    ... From the Federal Register Online via the Government Publishing Office TENNESSEE VALLEY AUTHORITY Sunshine Act Meeting Notice Meeting No. 12-02 April 26, 2012 The TVA Board of Directors will hold a public meeting on April 26, 2012, in the Grand Ballroom at the General Morgan Inn, 111 North Main...

  11. 75 FR 68719 - Endangered and Threatened Wildlife and Plants; Emergency Rule To Establish a Manatee Refuge in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-09

    ... manatees have increased since 1998 when the last sanctuary was designated in Kings Bay (63 FR 55553... public meetings will be held at the Plantation Inn and Golf Resort, 9301 W. Fort Island Trail, Crystal... informational public meetings is to provide the public with an opportunity to learn more about the...

  12. 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...

  13. 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.

  14. 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.…

  15. 76 FR 127 - The Central Valley Project, the California-Oregon Transmission Project, the Pacific Alternating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ... the proposed rate adjustments. \\1\\ See Rate Order No. WAPA-139, 73 FR 48381 (August 19, 2008). DATES... comments to Mr. Thomas R. Boyko, Regional Manager, or Mr. Charles J. Faust, Rates Manager, Sierra Nevada... host both the public information and public comment forums at: Lake Natoma Inn, 702 Gold Lake...

  16. 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

  17. 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

  18. 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,,…

  19. 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.

  20. 36 CFR 1005.8 - Discrimination in employment practices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Discrimination in employment practices. 1005.8 Section 1005.8 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.8 Discrimination in employment practices. (a) The proprietor, owner, or operator of any hotel, inn, lodge or other...

  1. ISSUES ASSOCIATED WITH DEPLOYMENT OF A TYPE OF PLANT-INCORPORATED PROTECTANT (PIP), SPECIFICALLY THOSE BASED ON PLANT VIRAL COAT PROTEINS

    EPA Science Inventory

    FIFRA Scientific Adivsory Panel Meeting, October 13-15,2004 held at the Holiday Inn-National Airport, Arlington, Virginia on: Issues Associated with Deployment of a Type of Plant-Incorporated Protectant (PIP), Specifically those based on Plant Viral Coat Proteins

  2. Simulating the Law: Experiential "Teachniques" in the Modern Law Curricula

    ERIC Educational Resources Information Center

    Daly, Yvonne; Higgins, Noelle

    2010-01-01

    The concept of arguing aspects of legal scenarios in order to facilitate student learning within the law curriculum originated in the vocational Inns of Court in fourteenth-century England. Nowadays, simulations of court proceedings, such as moot courts and mock trials, are widely employed as educational tools in law modules in third-level…

  3. 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. 

  4. 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.

  5. "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…

  6. 78 FR 4871 - Notice of Public Meeting: Northwest California Resource Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    ... Bureau of Land Management Notice of Public Meeting: Northwest California Resource Advisory Council AGENCY... (FACA), the U.S. Department of the Interior, Bureau of Land Management (BLM) Northwest California..., Feb. 21-22, 2013, at the Inn of the Lost Coast, 205 Wave Rd., Shelter Cove, California. On Feb....

  7. 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

  8. 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…

  9. 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…

  10. Synthesis of long indium nitride nanowires with uniform diameters in large quantities.

    PubMed

    Luo, Shudong; Zhou, Weiya; Zhang, Zengxing; Liu, Lifeng; Dou, Xinyuan; Wang, Jianxiong; Zhao, Xiaowei; Liu, Dongfang; Gao, Yan; Song, Li; Xiang, Yanjuan; Zhou, Jianjun; Xie, Sishen

    2005-10-01

    Large quantities of indium nitride (InN) nanowires are synthesized by the in situ nitriding of indium oxide (In(2)O(3)) powders in an ammonia (NH(3)) flux. Tens of milligrams of nanowires are obtained in one batch. Every 100 mg of In(2)O(3) starting powder can produce up to 65 mg of InN nanowires under the optimized conditions. The synthesized nanowires grow along the [001] direction with excellent crystallinity. They are of high purity and are 30-50 microm in length with an almost uniform diameter of about 100 nm. Photoluminescence measurements of the nanowires exhibit a strong peak at 707 nm. An optical bandgap of about 1.7 eV is estimated based on the absorption spectrum. The experimental results also demonstrate that the approach of nitriding In(2)O(3) powders in situ is feasible for the synthesis of high-purity InN nanowires in large quantities, with good reproducibility and without catalyst materials. The synthesis of InN nanowires in large quantities would be of benefit to the further study and understanding of their intrinsic properties, as well as being advantageous for their potential application in nanodevices. PMID:17193386

  11. 8. View south of north elevation at northeast corner of ...

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

    8. View south of north elevation at northeast corner of building. Window opens into 'Petite Cuisine' room (see HABS-CA-2611-B-18). - Deetjen's Big Sur Inn, Hayloft Building, East Side of State Highway 1, Big Sur, Monterey County, CA

  12. 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…

  13. 40 CFR Appendix D to Part 50 - Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... check: Check the photometer system for integrity, leaks, cleanliness, proper flowrates, etc. Service or..., as follows ER31AU93.030 where: E = linearity error, percent A1 = assay of the original concentration... generator, liter/min FD = diluent air flowrate, liter/min References 1. E.C.Y. Inn and Y....

  14. 77 FR 1941 - Center For Scientific Review; Amended Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-12

    ... Section, February 2, 2012, 8 a.m. to February 2, 2012, 7 p.m., George Washington University Inn, 824 New Hampshire Avenue NW., Washington, DC 20037 which was published in the Federal Register on January 4, 2012, 77 FR 296. The meeting will be held February 2, 2012, from 9 a.m. to 6 p.m. at The Westin...

  15. 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…

  16. 76 FR 46320 - Notice of Public Meeting, Southeast Oregon Resource Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... Bureau of Land Management Notice of Public Meeting, Southeast Oregon Resource Advisory Council AGENCY... Interior, Bureau of Land Management (BLM) Southeast Oregon Resource Advisory Council (RAC) will meet as... meetings will take place at the Sunridge Inn, 1 Sunridge Lane, Baker City, Oregon 97814. FOR...

  17. ISSUES AND APPLICATIONS IN TOXICOLOGY AND RISK ASSESSMENT (TOXICOLOGY CONFERENCE, APRIL 3-26, 2001)

    EPA Science Inventory

    Issues and Applications

    in

    Toxicology and Risk Assessment


    April 23-26, 2001

    Holiday Inn Conference Center

    2800 Presidential Drive

    <...

  18. Getting Down to Business: Innkeeping, Module 13. [Student Guide]. Entrepreneurship Training Components.

    ERIC Educational Resources Information Center

    Rassen, Rachel L.

    This module on owning and operating an inn is one of 36 in a series on entrepreneurship. The introduction tells the student what topics will be covered and suggests other modules to read in related occupations. Each unit includes student goals, a case study, and a discussion of the unit subject matter. Learning activities are divided into…

  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. 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

  1. The Place Where Hope Lives

    MedlinePlus

    ... and their families. Children need the comfort and security of their families—especially when they are being treated for a life-threatening illness far from home. The Children's Inn is a private, non-profit, family-centered residence at the National ...

  2. 75 FR 61860 - Advisory Committee on Women Veterans; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ... of women Veterans with respect to health care, rehabilitation, compensation, outreach, and other... AFFAIRS Advisory Committee on Women Veterans; Notice of Meeting The Department of Veterans Affairs (VA... Women Veterans will meet October 26-28, 2010, at the Hilton Garden Inn, in the Georgetown Ballroom,...

  3. 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

  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. 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

  6. 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.…

  7. 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…

  8. Mahlzeit! (Enjoy Your Meal!) German Table Manners, Menus, and Eating Establishments.

    ERIC Educational Resources Information Center

    Singer, Debbie

    A series of short texts focus on German eating habits and types of eating establishments. Vocabulary is glossed in the margin and each text is followed by comprehension questions. Menus from a restaurant, an inn, and a fast-food restaurant; vocabulary exercises; a word search puzzle and its solution; and directions in English for conversational…

  9. 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…

  10. 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.

  11. Allergic vasculitis

    MedlinePlus

    ... Cutaneous vasculitis Images Vasculitis on the palm Vasculitis Vasculitis, urticarial on the hand References Stone JH. The systemic vasculitides. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. ... small vessel vasculitis. In: Firestein GS, Budd RC, Gabriel SE, McInnes ...

  12. 77 FR 58526 - Pacific Fishery Management Council; Public Meeting; Work Session To Review Proposed Salmon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... Meeting; Work Session To Review Proposed Salmon Methodology Changes AGENCY: National Marine Fisheries... proposed salmon methodology changes in a joint work session, which is open to the public. DATES: The work..., 2012 from 9 a.m. to 3 p.m. ADDRESSES: The work session will be held at the Shilo Inns Suites...

  13. 77 FR 42486 - Intent To Prepare an Integrated Water Supply Storage Reallocation Report; Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-19

    ... the headwaters of Fort Peck Reservoir, Ft. Peck, MT to St. Louis, MO. Project Scope. The demand for M...: Holiday Inn, 701 Gordon Drive. August 27, 2012--Pierre, SD: Best Western Ramkota, 920 W. Sioux Avenue... Avenue. August 29, 2012--Glasgow, MT: Fort Peck Visitor Center, Highway 24 South 17 miles to Fort...

  14. 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.

  15. 75 FR 35009 - York Haven Power Company, LLC; Notice of Cancellation of Dispute Resolution Panel Meeting and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... Panel Meeting and Technical Conference June 11, 2010. The technical conference scheduled for Monday, June 14, 2010, from 1 p.m. to 5 p.m. at the Holiday Inn and Conference Center in New Cumberland, PA is... study dispute filed on April 29, 2010. The technical meeting is cancelled in response to the...

  16. 75 FR 27776 - City of Seattle, Public Utility District No. 1 of Pend Orielle County; Notice of Technical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... conference will be held on Thursday, June 10, 2010, beginning at 9 a.m. (PST) at Quality Inn Oakwood, 7919... should meet at the Boundary powerhouse gate at 10:15 a.m. (PST). For those persons only interested in...

  17. 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...

  18. 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...

  19. 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

  20. 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.

  1. 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

  2. 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)

  3. Revealing of the transition from n- to p-type conduction of InN:Mg by photoconductivity effect measurement

    PubMed Central

    Guo, L.; Wang, X. Q.; Zheng, X. T.; Yang, X. L.; Xu, F. J.; Tang, N.; Lu, L. W.; Ge, W. K.; Shen, B.; Dmowski, L. H.; Suski, T.

    2014-01-01

    We report evidence of the transition from n- to p-type conduction of InN with increasing Mg dopant concentration by using photoconductivity (PC) measurement at room temperature. This transition is depicted as a conversion from negative to positive PC under above-bandgap optical excitation. The n- to p-type transition in InN:Mg is further confirmed by thermopower measurements. PC detection method is a bulk effect since the optical absorption of the surface electron accumulation is negligibly low due to its rather small thickness, and thus shows advantage to detect p-type conduction. This technique is certainly helpful to study p-type doping of InN, which is still a subject of discussions. PMID:24621830

  4. Synchrotron x-ray scattering study on the evolution of surface morphology of the InN/Al2O3)(0001 system

    NASA Astrophysics Data System (ADS)

    Lee, Ik Jae; Kim, Jin Woo; Hur, Tae-Bong; Hwang, Yoon-Hwae; Kim, Hyung-Kook

    2002-07-01

    Dynamic scaling behavior was studied for InN films grown on sapphire(0001) substrates using high-resolution synchrotron x-ray reflectivity and atomic force microscopy measurements. In the early stage of growth, highly strained planar InN films were grown. As the film thickness approaches an effective critical thickness, the growth gradually crosses over to the island growth. Concurrently, the relaxation of the lattice strain begins and the growth front becomes rougher. The roughness increases mostly during the intermediate crossover regime where the strain is relieved. In this regime, the dynamic scaling exponent, beta, is estimated as 1.754plus-or-minus0.071. The evolution of the surface roughness in the final-stage growth can be described by the dynamic scaling exponent of 0.236plus-or-minus0.022.

  5. 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.

  6. Quantized Electron Accumulation States in Indium Nitride Studied by Angle-Resolved Photoemission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Colakerol, Leyla; Veal, T. D.; Jeong, Hae-Kyung; Plucinski, Lukasz; Demasi, Alex; Learmonth, Timothy; Glans, Per-Anders; Wang, Shancai; Zhang, Yufeng; Piper, L. F. J.; Jefferson, P. H.; Fedorov, Alexei; Chen, Tai-Chou; Moustakas, T. D.; McConville, C. F.; Smith, Kevin E.

    2006-12-01

    Electron accumulation states in InN have been measured using high resolution angle-resolved photoemission spectroscopy (ARPES). The electrons in the accumulation layer have been discovered to reside in quantum well states. ARPES was also used to measure the Fermi surface of these quantum well states, as well as their constant binding energy contours below the Fermi level EF. The energy of the Fermi level and the size of the Fermi surface for these quantum well states could be controlled by varying the method of surface preparation. This is the first unambiguous observation that electrons in the InN accumulation layer are quantized and the first time the Fermi surface associated with such states has been measured.

  7. Geographically predominant genotypes of Aspergillus terreus species complex in Austria: s microsatellite typing study.

    PubMed

    Lackner, M; Coassin, S; Haun, M; Binder, U; Kronenberg, F; Haas, H; Jank, M; Maurer, E; Meis, J F; Hagen, F; Lass-Flörl, C

    2016-03-01

    Aspergillus terreus species complex is recognized as a frequent agent of invasive aspergillosis in Tyrol. The reason for this specific epidemiological situation is unclear. Aspergillus terreus strains isolated from environmental and clinical sources were genotyped using a novel panel of short tandem repeats and were evaluated for virulence. Three major endemic genotypes collected from the Inn region and its side valleys were found to cause the majority of invasive A. terreus infections. All of these genotypes were of the same mating type, which suggests that a mating barrier is present between these geographically well-adapted strains which is found to persist for at least 11 years. The three major genotypes were prevalent in both human infections and the environment. No major differences in virulence were observed using Galleria mellonella as model. Our data suggest a specific environmental exposure being responsible for the high incidence of A. terreus infections in Innsbruck, the Inn valley and side valleys (Tyrol, Austria). PMID:26577144

  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. 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.

  10. Photoluminescence and pressure effects in short period InN/nGaN superlattices

    NASA Astrophysics Data System (ADS)

    Staszczak, G.; Gorczyca, I.; Suski, T.; Wang, X. Q.; Christensen, N. E.; Svane, A.; Dimakis, E.; Moustakas, T. D.

    2013-03-01

    Measurements of photoluminescence and its dependence on hydrostatic pressure are performed on a set of InN/nGaN superlattices with one InN monolayer and with different numbers of GaN monolayers. The emission energies, EPL, measured at ambient pressure, are close to the value of the band gap, Eg, in bulk GaN, in agreement with other experimental findings. The pressure dependence of the emission energies, dEPL/dp, however, resembles that of the InN energy gap. Further, the magnitudes of both EPL and dEPL/dp are significantly higher than those obtained from ab-initio calculations for 1InN/nGaN superlattices. Some causes of these discrepancies are suggested.

  11. Epitaxial InN/InGaN quantum dots on Si: Cl‑ anion selectivity and pseudocapacitor behavior

    NASA Astrophysics Data System (ADS)

    Rodriguez, Paul E. D. Soto; Mari, Claudio Maria; Sanguinetti, Stefano; Ruffo, Riccardo; Nötzel, Richard

    2016-08-01

    Epitaxial InN quantum dots (QDs) on In-rich InGaN, applied as an electrochemical electrode, activate Cl‑-anion-selective surface attachment, bringing forth faradaic/pseudocapacitor-like behavior. In contrast to traditional pseudocapacitance, here, no chemical reaction of the electrode material occurs. The anion attachment is explained by the unique combination of the surface and quantum properties of the InN QDs. A high areal capacitance is obtained for this planar electrode together with rapid and reversible charge/discharge cycles. With the growth on cheap Si substrates, the InN/InGaN QD electrochemical electrode has great potential, opening up new application fields for III–nitride semiconductors.

  12. 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.

  13. Auger recombination as the dominant recombination process in indium nitride at low temperatures during steady-state photoluminescence

    NASA Astrophysics Data System (ADS)

    Seetoh, I. P.; Soh, C. B.; Fitzgerald, E. A.; Chua, S. J.

    2013-03-01

    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.

  14. 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

  15. 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

  16. 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.

  17. 33 CFR 110.72aa - Elizabeth River Spectator Vessel Anchorage Areas, between Norfolk and Portsmouth, Virginia.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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, 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...

  19. 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...

  20. 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...

  1. 33 CFR 110.72aa - Elizabeth River Spectator Vessel Anchorage Areas, between Norfolk and Portsmouth, Virginia.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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...

  2. 78 FR 66033 - Center for Scientific Review; Amended Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Section, October 3, 2013, 08:00 a.m. to October 3, 2013, 05:00 p.m., George Washington University Inn, 824 New Hampshire Avenue NW., Washington, DC 20037, which was published in the Federal Register on September 9, 2013, 78 FR 55086. The meeting will be held on November 22, 2013 from 10:00 a.m. to 4:00...

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26687421

  8. Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111) substrate

    SciTech Connect

    Sangeetha, P.; Ramakrishnan, V.; Jeganathan, K.

    2013-06-15

    The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE) on Si (111) substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E{sub 2} (high) and A{sub 1} (LO) phonon mode of InN core at 490 and 590 cm{sup -1} respectively and E{sub 2} (high) phonon mode of GaN shell at 573 cm{sup -1}. The free carrier concentration of InN core is found to be low in the order {approx} 10{sup 16} cm{sup -3} due to the screening of charge carriers by thin GaN shell. Diameter of InN core evaluated using the spatial correlation model is consistent with the transmission electron microscopic measurement of {approx}15 nm. The phonon-life time of core-shell nanowire structure is estimated to be {approx}0.4 ps. The micro-Raman mapping and its corresponding localised spectra for 325 nm excitation exhibit intense E{sub 2} (high) phonon mode of GaN shell at 573 cm{sup -1} as the decrease of laser interaction length and the signal intensity is quenched at the voids due to high spacing of NWs.

  9. The immiscibility of InAlN ternary alloy.

    PubMed

    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

  10. Ingression Progression Complexes Control Extracellular Matrix Remodelling during Cytokinesis in Budding Yeast.

    PubMed

    Foltman, Magdalena; Molist, Iago; Arcones, Irene; Sacristan, Carlos; Filali-Mouncef, Yasmina; Roncero, Cesar; Sanchez-Diaz, Alberto

    2016-02-01

    Eukaryotic cells must coordinate contraction of the actomyosin ring at the division site together with ingression of the plasma membrane and remodelling of the extracellular matrix (ECM) to support cytokinesis, but the underlying mechanisms are still poorly understood. In eukaryotes, glycosyltransferases that synthesise ECM polysaccharides are emerging as key factors during cytokinesis. The budding yeast chitin synthase Chs2 makes the primary septum, a special layer of the ECM, which is an essential process during cell division. Here we isolated a group of actomyosin ring components that form complexes together with Chs2 at the cleavage site at the end of the cell cycle, which we named 'ingression progression complexes' (IPCs). In addition to type II myosin, the IQGAP protein Iqg1 and Chs2, IPCs contain the F-BAR protein Hof1, and the cytokinesis regulators Inn1 and Cyk3. We describe the molecular mechanism by which chitin synthase is activated by direct association of the C2 domain of Inn1, and the transglutaminase-like domain of Cyk3, with the catalytic domain of Chs2. We used an experimental system to find a previously unanticipated role for the C-terminus of Inn1 in preventing the untimely activation of Chs2 at the cleavage site until Cyk3 releases the block on Chs2 activity during late mitosis. These findings support a model for the co-ordinated regulation of cell division in budding yeast, in which IPCs play a central role. PMID:26891268

  11. Ingression Progression Complexes Control Extracellular Matrix Remodelling during Cytokinesis in Budding Yeast

    PubMed Central

    Foltman, Magdalena; Molist, Iago; Arcones, Irene; Sacristan, Carlos; Filali-Mouncef, Yasmina; Roncero, Cesar; Sanchez-Diaz, Alberto

    2016-01-01

    Eukaryotic cells must coordinate contraction of the actomyosin ring at the division site together with ingression of the plasma membrane and remodelling of the extracellular matrix (ECM) to support cytokinesis, but the underlying mechanisms are still poorly understood. In eukaryotes, glycosyltransferases that synthesise ECM polysaccharides are emerging as key factors during cytokinesis. The budding yeast chitin synthase Chs2 makes the primary septum, a special layer of the ECM, which is an essential process during cell division. Here we isolated a group of actomyosin ring components that form complexes together with Chs2 at the cleavage site at the end of the cell cycle, which we named ‘ingression progression complexes’ (IPCs). In addition to type II myosin, the IQGAP protein Iqg1 and Chs2, IPCs contain the F-BAR protein Hof1, and the cytokinesis regulators Inn1 and Cyk3. We describe the molecular mechanism by which chitin synthase is activated by direct association of the C2 domain of Inn1, and the transglutaminase-like domain of Cyk3, with the catalytic domain of Chs2. We used an experimental system to find a previously unanticipated role for the C-terminus of Inn1 in preventing the untimely activation of Chs2 at the cleavage site until Cyk3 releases the block on Chs2 activity during late mitosis. These findings support a model for the co-ordinated regulation of cell division in budding yeast, in which IPCs play a central role. PMID:26891268

  12. 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

  13. Short period InN/nGaN superlattices: experiment versus theory

    NASA Astrophysics Data System (ADS)

    Suski, T.; Gorczyca, I.; Staszczak, G.; Wang, X. Q.; Christensen, N. E.; Svane, A.; Dimakis, E.; Moustakas, T. D.

    2013-03-01

    Measurements of photoluminescence and its dependence on hydrostatic pressure are performed on a set of InN/nGaN superlattices with one InN monolayer, and with different numbers of GaN monolayers (n from 1 to 40). The emission energies, EPL, measured at ambient pressure, are close to the value of the band gap, Eg, in bulk GaN, in agreement with other experimental findings. The pressure dependence of the emission energies, dEPL/dp, however, resembles that of the InN energy gap. Further, the magnitudes of both EPL and dEPL/dp are significantly higher than those obtained from abinitio calculations for 1InN/nGaN superlattices. Some causes of these discrepancies are suggested...Detailed analysis of the electronic band structure of 1InN/5GaN superlattice is performed showing that the built-in electric field plays an important role in the mInN/nGaN structures. It strongly influences the valence- and conduction-band profiles and thus determines the effective band gap.

  14. Composition and luminescence studies of InGaN epilayers grown at different hydrogen flow rates

    NASA Astrophysics Data System (ADS)

    Taylor, E.; Fang, F.; Oehler, F.; Edwards, P. R.; Kappers, M. J.; Lorenz, K.; Alves, E.; McAleese, C.; Humphreys, C. J.; Martin, R. W.

    2013-06-01

    Indium gallium nitride (InxGa1 - xN) is a technologically important material for many optoelectronic devices, including LEDs and solar cells, but it remains a challenge to incorporate high levels of InN into the alloy while maintaining sample quality. A series of InGaN epilayers was grown with different hydrogen flow rates (0-200 sccm) and growth temperatures (680-750 °C) to obtain various InN fractions and bright emission in the range 390-480 nm. These 160-nm thick epilayers were characterized through several compositional techniques (wavelength dispersive x-ray spectroscopy, x-ray diffraction, Rutherford backscattering spectrometry) and cathodoluminescence hyperspectral imaging. The compositional analysis with the different techniques shows good agreement when taking into account compositional gradients evidenced in these layers. The addition of small amounts of hydrogen to the gas flow at lower growth temperatures is shown to maintain a high surface quality and luminescence homogeneity. This allowed InN fractions of up to ˜16% to be incorporated with minimal peak energy variations over a mapped area while keeping a high material quality.

  15. Microvascular decompression of the posterior inferior cerebellar artery for intermediate nerve neuralgia

    PubMed Central

    Schroeder, Humberto Kluge; Neville, Iuri Santana; de Andrade, Daniel Ciampi; Lepski, Guilherme Alves; Teixeira, Manoel Jacobsen; Duarte, Kleber Paiva

    2015-01-01

    Background: Intermediate nerve neuralgia (INN) is an extremely rare craniofacial pain disorder mainly caused by neurovascular compression. Case Description: We present the case of a 48-year-old female with a 20-month history of intractable paroxysmal INN on the right side. The patient described feeling paroxysmal pain in her auditory canal, pinna, deep in the jaw, and adjacent retromastoid area on the right side. She described the pain as being like a burning sensation. Magnetic resonance imaging showed the right posterior cerebellar artery crossing the cerebellopontine cistern in close contact with the right VII and VIII nerves. Surgical exploration via retromastoid craniotomy revealed vascular compression of the intermediate nerve by the posterior cerebellar artery. We therefore performed microvascular nerve decompression to relieve pain, and the patient remained pain-free at the 6-month follow-up visit. Conclusion: INN should be considered as a differential diagnosis in cases with atypical facial neuralgia, and microvascular decompression is an effective treatment option that can provide optimal pain relief. PMID:25883844

  16. 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.

  17. The immiscibility of InAlN ternary alloy

    NASA Astrophysics Data System (ADS)

    Zhao, Guijuan; Xu, Xiaoqing; Li, Huijie; Wei, Hongyuan; Han, Dongyue; Ji, Zesheng; Meng, Yulin; Wang, Lianshan; Yang, Shaoyan

    2016-05-01

    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.

  18. Morphology and composition controlled growth of polar c-axis and nonpolar m-axis well-aligned ternary III-nitride nanotube arrays.

    PubMed

    Li, Huijie; Zhao, Guijuan; Kong, Susu; Han, Dongyue; Wei, Hongyuan; Wang, Lianshan; Chen, Zhen; Yang, Shaoyan

    2015-10-21

    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. PMID:26395389

  19. 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. PMID:26694227

  20. Growth and characterization of group iiinitrides by migration-enhanced afterglow epitaxy

    NASA Astrophysics Data System (ADS)

    Gergova, Rositsa

    The work presented in this thesis investigates the growth and properties of group III- nitride semiconductors that were grown using the Migration Enhanced Afterglow Epitaxy (MEAglow) method. This work was to enhance the understanding of the MEAglow growth process towards the improvement of quality of the layers grown using this technique. The MEAglow technique applies the migration enhanced epitaxy method in a low pressure plasma-based CVD reactor, which has a potential of producing high quality epitaxial group III-nitride layers at relatively low growth temperatures on large deposition areas. The low temperature pulse growth in metal-rich regime, comprising the MME method was employed under growth pressures between 500 mTorr and 3000 mTorr. As the MME method up to this point has been used only for MBE systems, study of the impact of the growth pressure on the materials properties was necessary. In this work the pressure dependence was mapped to an existing surface phase diagram for MBE systems by calculating the number of nitrogen gas phase collisions and the metalorganic bombardment rate, for the specific to the prototype reactor parameters, to a first approximation. This was done in order to achieve an intermediate regime free of metal droplets for growth in metal-rich regime. High quality epitaxial InN layers were accomplished on extremely thin and smooth Ga2O3 buffer layers. These results indicate a potential for the application of Ga2O3 buffers in InN growth. The MEAglow InN layers were further optimized for growth on commercially available GaN buffer layers and excellent two-dimensional growth was achieved for layers grown under metal-rich conditions at 512 °C. Post-growth annealing studies were carried out for InN layers grown at temperatures below 400 °C to study the limiting processes of the removal of excess nitrogen, believed to be a dominant defect in InN films grown in plasma-based systems at very low temperatures. Variations in GaN stoichiometry

  1. Simulated recruitment of medial rectus motoneurons by abducens internuclear neurons: synaptic specificity vs. intrinsic motoneuron properties.

    PubMed

    Dean, P

    1997-09-01

    Ocular motoneuron firing rate is linearly related to conjugate eye position with slope K above recruitment threshold theta. Within the population of ocular motoneurons K increases as theta increases. These differences in firing rate between motoneurons might be determined either by the intrinsic properties of the motoneurons, or by differences in synaptic input to them, or by a combination of the two. This question was investigated by simulating the input signal to medial rectus motoneurons (MR-MNs) from internuclear neurons of the abducens nucleus (INNs). INNs were represented as input nodes in a two-layer neural net, each with weighted connections to every output node representing an MR-MN. Individual simulated MR-MNs were assigned parameters corresponding to an intrinsic current threshold I(R) and an intrinsic frequency-current (f-I) slope gamma. Their firing rates were calculated from these parameters, together with the effective synaptic current produced by their synaptically weighted INN inputs, with the use of assumptions employed in computer simulations of spinal motoneuron pools. The experimentally observed firing rates of MR-MNs served as training data for the net. The following two training conditions were used: 1) synaptic weights were fixed and the intrinsic parameters of the MR-MNs were allowed to vary, corresponding to the situation in which each MR-MN receives a common synaptic drive and 2) intrinsic MR-MN properties were fixed and synaptic weights were allowed to vary. In each case, the varying quantities were trained with a form of gradient descent error reduction. The simulations revealed the following three problems with the common-drive model: 1) the recruitment of INNs produced nonlinear responses in MR-MNs with low thetas; 2) the range of I(R)s required to reproduce the observed range of theta were generally larger than those measured experimentally for cat ocular motoneurons; and 3) the intrinsic f-I slope gamma increased with I

  2. Drug Susceptibility and Viral Fitness of HIV-1 with Integrase Strand Transfer Inhibitor Resistance Substitution Q148R or N155H in Combination with Nucleoside/Nucleotide Reverse Transcriptase Inhibitor Resistance Substitutions

    PubMed Central

    Miller, Michael D.; White, Kirsten L.

    2015-01-01

    In clinical trials of coformulated elvitegravir (EVG), cobicistat (COBI), emtricitabine (FTC), and tenofovir disoproxil fumarate (TDF), emergent drug resistance predominantly involved the FTC resistance substitution M184V/I in reverse transcriptase (RT), with or without the tenofovir (TFV) resistance substitution K65R, accompanied by a primary EVG resistance substitution (E92Q, N155H, or Q148R) in integrase (IN). We previously reported that the RT-K65R, RT-M184V, and IN-E92Q substitutions lacked cross-class phenotypic resistance and replicative fitness compensation. As a follow-up, the in vitro characteristics of mutant HIV-1 containing RT-K65R and/or RT-M184V with IN-Q148R or IN-N155H were also evaluated, alone and in combination, for potential interactions. Single mutants displayed reduced susceptibility to their corresponding inhibitor classes, with no cross-class resistance. Viruses with IN-Q148R or IN-N155H exhibited reduced susceptibility to EVG (137- and 40-fold, respectively) that was not affected by the addition of RT-M184V or RT-K65R/M184V. All viruses containing RT-M184V were resistant to FTC (>1,000-fold). Mutants with RT-K65R had reduced susceptibility to TFV (3.3- to 3.6-fold). Without drugs present, the viral fitness of RT and/or IN mutants was diminished relative to that of the wild type in the following genotypic order: wild type > RT-M184V ≥ IN-N155H ≈ IN-Q148R ≥ RT-M184V + IN-N155H ≥ RT-M184V + IN-Q148R ≥ RT-K65R/M184V + IN-Q148R ≈ RT-K65R/M184V + IN-N155H. In the presence of drug concentrations approaching physiologic levels, drug resistance counteracted replication defects, allowing single mutants to outcompete the wild type with one drug present and double mutants to outcompete single mutants with two drugs present. These results suggest that during antiretroviral treatment with multiple drugs, the development of viruses with combinations of resistance substitutions may be favored despite diminished viral fitness. PMID:26574015

  3. Band anticrossing effects in highly mismatched semiconductor alloys

    NASA Astrophysics Data System (ADS)

    Wu, Junqiao

    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 ˜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 InAIN 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 InAIN were found to cover a wide spectral range from the infrared for InN to the ultraviolet for GaN and deep ultraviolet for AIN. The significance of this work is rooted in many important applications of nitride semiconductors in optoelectronics and solar energy conversion devices.

  4. 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.

  5. 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

  6. Near infrared electroluminescence of ZnMgO/InN core-shell nanorod heterostructures grown on Si substrate.

    PubMed

    Wu, Guoguang; Zheng, Weitao; Gao, Fubin; Yang, Hang; Zhao, Yang; Yin, Jingzhi; Zheng, Wei; Li, Wancheng; Zhang, Baolin; Du, Guotong

    2016-07-27

    This paper presents a systematic investigation of a ZnMgO/InN core-shell nanorods heterojunction device on a p-Si substrate. Here we demonstrated the heteroepitaxial growth of the well-aligned ZnMgO/InN core-shell nanorods structure, which enabled an increased heterojunction area to improve the carrier injection efficiency of nanodevices by plasma-assisted molecular beam epitaxy combined with metal-organic chemical vapor deposition. In situ X-ray photoelectron spectroscopy measurements were performed on the ZnMgO nanorods, the interface of ZnMgO/InN and the InN core-shell nanorods to fully understand the structure and working mechanism of the heterojunction device. The current transport mechanism has been discussed in terms of the characteristics of current-voltage and the energy band diagram of the n-InN/ZnMgO/p-Si heterojunction. At a low forward voltage, the current transport followed the dependence of I ∼ V(1.47), which was attributed to the deep-level assisted tunneling. When the forward voltage was larger than 10 V, the current followed the relation of I ∼ V(2) because of the radiative recombination process. In accordance with the above conclusion, the near-infrared electroluminescence of the diode could be observed after the forward bias voltage up to 11.6 V at room temperature. In addition, the size quantization effect and the intrinsic electron accumulation of the InN core-shell nanorods were investigated to explain the blueshift and broadened bandwidth. Furthermore, the light output power of about 0.6 microwatt at a fixed wavelength of 1500 nm indicated that our study will further provide a useful route for realizing the near-infrared electroluminescence of InN on Si substrate. PMID:27418413

  7. High efficiency, radiation-hard solar cells

    SciTech Connect

    Ager III, J.W.; Walukiewicz, W.

    2004-10-22

    The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is a less significant effect at large x. Evidence of p-type activity below the surface in Mg-doped InN was obtained; this is a significant step toward achieving photovoltaic action and, ultimately, a solar cell using this material.

  8. 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.

  9. Bias-free lateral terahertz emitters—A simulation study

    NASA Astrophysics Data System (ADS)

    Granzner, R.; Polyakov, V. M.; Cimalla, V.; Ambacher, O.; Schwierz, F.

    2015-07-01

    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.

  10. Report on the technical workshop on WTI incinerator risk issues. Held in Washington, DC on December 8-9, 1993

    SciTech Connect

    Not Available

    1993-12-01

    The report includes information and materials from a peer review workshop organized by EPA's Risk Assessment Forum (RAF) for the Office of Solid Waste and Emergency Response and Region 5. The meeting was held in Washington, DC, at the Holiday Inn Capitol on December 8-9, 1993. The subject of the peer review was a draft project plan prepared by EPA Region 5 for assessing risk at an incinerator operated by Waste Technologies Industries (WTI) in East Liverpool, Ohio. The peer review panel was convened to evaluate the project plan as the scientific foundation for a risk assessment, which will be used in setting final permit conditions for the WTI facility.

  11. Workshop on seedling physiology and growth problems in oak plantings (5th) (abstracts). Held in Ames, Iowa on March 4-5, 1992. Forest Service general technical report

    SciTech Connect

    Thompson, J.R.; Schultz, R.C.; Van Sambeek, J.W.

    1993-01-01

    The fifth workshop on seedling physiology and growth problems in oak plantings was held at the Holiday Inn Gateway Center in Ames, Iowa on March 4 and 5, 1992 with more than 45 participants. The workshop continues to serve as an informal forum for researchers to exchange ideas and research results. Papers were divided into four general subject areas: (1) field performance of planted oaks, (2) seedling propagation and production, (3) oak physiology and genetics, and (4) natural and acorn germination regeneration. All abstracts prepared for the workshop are included in the technical report.

  12. Speculations on the spatial setting and temporal evolution of a fjord-style lake

    NASA Astrophysics Data System (ADS)

    Sarnthein, M.; Spötl, C.

    2012-04-01

    The Inn Valley, a classical region of Quaternary research in the Alps, is bordered by terraces that extend over almost 70 km and record an ancient lake with a lake level near 750-830 m above sea level (a.s.l.), about 250-300 m above the modern valley floor. Over large distances, the terrace sediments consist mainly of laminated "Banded Clays", above ~750 m a.s.l. overlain by glaciofluvial gravel and finally, by tills that record the Upper Würmian ice advance of Marine Isotope Stage (MIS) 2. In the (former) clay pit of Baumkirchen this boundary forms the Alpine type locality for the onset of the Upper Würmian, well supported by 14C-based age control first established by Fliri (1971). On the basis of a recently cored sediment section at Baumkirchen, the >200 m thick "Banded Clays" store a continuous, largely undisturbed, highly resolved, and widely varved climatic archive of MIS 3. Major unknowns concern the location and origin of dams that may have barred the vast and deep Inn Valley lake. We discuss potential linkages to the pattern of moraines and ice advance of MIS 4 glaciers, which was less prominent than during MIS 2, thus leading to a distinct east-west segment¬ation of the run-off systems in Tyrol. East of Imst, for example, the lake was possibly barred by both a rock sill reaching up to 830 m a.s.l. and a lateral moraine deposited by an Ötz Valley glacier. 80 km further east, a lateral moraine of a glacier advancing from the Ziller Valley may have barred the ancient Inn Valley lake to the east. The final rapid coarsening of clastic lake sediments at the end of MIS 3 is widely ascribed to major climatic deter¬ioration. However, the MIS 3-2 boundary was linked to an only modest change of global climates and accordingly, different forcings may be considered. In turn, the rapid coarsening may document a date, when the Central Alpine glaciers had already filled the basin of Imst to the west of the Inn Valley lake. This ice mass may have forced the melt

  13. 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.

  14. 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)

    2012-06-28

    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).

  15. 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.

  16. The parameters in the band-anticrossing model for In x Ga1- x N y P1- y before and after annealing

    NASA Astrophysics Data System (ADS)

    Zhao, Chuanzhen; Zhang, Rong; Liu, Bin; Yu, Liyuan; Tang, Chunxiao; Xie, Zili; Xiu, Xiangqian; Zheng, Youdou

    2011-12-01

    We investigate the parameters in the band-anticrossing (BAC) model for GaNP and InGaPN in this work. The parameters in the BAC model for GaNP and InGaNP are obtained by fitting experimental data. It is found that the band gap bowing of In-GaNP is stronger than that of InGaNAs. The effects of annealing on the parameters in the BAC model for InGaNP are also discussed in this work. In addition, the origins for improving luminescence efficiency by annealing are explained. It is relative to the forming of more In-N clusters.

  17. Optical control of internal electric fields in band gap-graded InGaN nanowires.

    PubMed

    Erhard, N; Sarwar, A T M Golam; Yang, F; McComb, D W; Myers, R C; Holleitner, A W

    2015-01-14

    InGaN nanowires are suitable building blocks for many future optoelectronic devices. We show that a linear grading of the indium content along the nanowire axis from GaN to InN introduces an internal electric field evoking a photocurrent. Consistent with quantitative band structure simulations we observe a sign change in the measured photocurrent as a function of photon flux. This negative differential photocurrent opens the path to a new type of nanowire-based photodetector. We demonstrate that the photocurrent response of the nanowires is as fast as 1.5 ps. PMID:25487601

  18. Optical Control of Internal Electric Fields in Band Gap-Graded InGaN Nanowires

    NASA Astrophysics Data System (ADS)

    Erhard, N.; Sarwar, A. T. M. Golam; Yang, F.; McComb, D. W.; Myers, R. C.; Holleitner, A. W.

    2015-01-01

    InGaN nanowires are suitable building blocks for many future optoelectronic devices. We show that a linear grading of the indium content along the nanowire axis from GaN to InN introduces an internal electric field evoking a photocurrent. Consistent with quantitative band structure simulations we observe a sign change in the measured photocurrent as a function of photon flux. This negative differential photocurrent opens the path to a new type of nanowire-based photodetector. We demonstrate that the photocurrent response of the nanowires is as fast as 1.5 ps.

  19. 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.

  20. 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

  1. Meeting report: GARNet/OpenPlant CRISPR-Cas workshop.

    PubMed

    Parry, Geraint; Patron, Nicola; Bastow, Ruth; Matthewman, Colette

    2016-01-01

    Targeted genome engineering has been described as a "game-changing technology" for fields as diverse as human genetics and plant biotechnology. One technique used for precise gene editing utilises the CRISPR-Cas system and is an effective method for genetic engineering in a wide variety of plants. However, many researchers remain unaware of both the technical challenges that emerge when using this technique or of its potential benefits. Therefore in September 2015, GARNet and OpenPlant organized a two-day workshop at the John Innes Centre that provided both background information and hands-on training for this important technology. PMID:26823675

  2. 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

  3. 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.

  4. Polarization-Driven Topological Insulator Transition in a GaN/InN/GaN Quantum Well

    SciTech Connect

    Miao, M. S.; Yan, Q.; Van de Walle, C. G.; Lou, W. K.; Li, L. L.; Chang, K.

    2012-11-02

    Topological insulator (TI) states have been demonstrated in materials with a narrow gap and large spin-orbit interactions (SOI). Here we demonstrate that nanoscale engineering can also give rise to a TI state, even in conventional semiconductors with a sizable gap and small SOI. Based on advanced first-principles calculations combined with an effective low-energy k∙p Hamiltonian, we show that the intrinsic polarization of materials can be utilized to simultaneously reduce the energy gap and enhance the SOI, driving the system to a TI state. The proposed system consists of ultrathin InN layers embedded into GaN, a layer structure that is experimentally achievable.

  5. Reactive nitrogen source based on ECR discharge sustained by 24 GHz radiation

    NASA Astrophysics Data System (ADS)

    Vodopyanov, Alexander; Mansfeld, Dmitry

    2015-04-01

    One of the key problems in the synthesis of group III nitrides is the development of an effective source of reactive nitrogen, which is necessary for incorporation into the crystal lattice. In this paper, we describe a source of reactive nitrogen based on ECR discharge plasma, which is sustained by technological gyrotron radiation. Measurements of atomic nitrogen flux were conducted by mass-spectrometric analysis of the products of the reaction of nitrogen monoxide with atomic nitrogen. The maximal atomic nitrogen flow was 5 × 1018 atoms/s (12 sccm). The atomic source was used to grow InN films.

  6. 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.

  7. Initial testing of the tritium systems at the Tokamak Fusion Test Reactor

    SciTech Connect

    Anderson, J.L.; Sissingh, R.A.P.; Gentile, C.A.; Rossmassler, R.L.; Walters, R.T.; Voorhees, D.R.

    1993-11-01

    The Tokamak Fusion Test Reactor (TFTR) at Princeton will start its D-T experiments in late 1993, introducing and operating the tokamak with tritium in order to begin the study of burning plasma physics in D-T. Trace tritium injection experiments, using small amounts of tritium will begin in the fall of 1993. In preparation for these experiments, a series of tests with low concentrations of tritium inn deuterium have been performed as an initial qualification of the tritium systems. These tests began in April 1993. This paper describes the initial testing of the equipment in the TFTR tritium facility.

  8. 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.

  9. Development of group III/nitride core/shell heterostructures by atomic layer deposition on nanorods

    NASA Astrophysics Data System (ADS)

    Revelli, Joseph C.

    A nanostructured LED design has been proposed in which a p-GaN/i-InyGa1- yN/n-GaN double heterostructure is deposited on p-GaN nanorods that are grown on a Si substrate. The design advantages include: 1) a ten-fold increase in active area for photo-generative recombination resulting in an increase in brightness, 2) increase in photon extraction efficiency, and 3) growth on Si wafers that eliminates the need for topside contacts and possible integration with other Si-based technologies. The feasibility of using atomic layer deposition (ALD) was studied both experimentally and theoretically as a means of fabricating the proposed nano-structure LED. The ALD process window for growing thin films of GaN on Si substrates from GaCl3 and NH3 was determined. Optimum ALD growth was obtained with a GaCl3 exposure time of 2-8 sec followed by a 30 sec nitrogen purge, a 10 sec NH3 pulse, and another 30 sec nitrogen purge. One cycle resulted in 2.56 A of growth over the entire ALD process window and ALD films obtained with these conditions were found to be extremely uniform in thickness with many samples having roughness as low as 0.3 to 0.5 nm. These ALD conditions were then applied to growth of GaN on InN nanorods. Randomly-oriented polycrystalline structures were observed for samples grown in the temperature range 565 to 580°C. For growth at a temperature of 595°C the GaN shells were more crystalline but at a cost of decomposition of the underlying InN nanorod. For growth at any temperature in the range 565 to 595°C the InN and GaN domains tended to delaminate and show two separate sets of diffraction spots as shell thickness increased. Analytical models were developed to predict the mechanical stability of core/shell heterostructures fabricated from materials with dissimilar lattice constants. The models predict that there is no thickness of pure InN core and pure GaN shell that yields stable, defect-free shells. However, with alloyed shells, the model predicts a range of

  10. 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.

  11. 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).

  12. 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.

  13. 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

  14. A small simple thing. Interview by Barbara Sibbald.

    PubMed

    Tulloch, L

    1998-11-01

    Lori Tulloch caters to the migrating men of the morning who rove from one dumpster to the next searching for bottles, food, whatever. Her Whitehorse, Yukon clinic is deliberately on their route, in a cramped room of an aging downtown hotel, and they stop by for a little snack, warm socks, needle exchange, advice or maybe just a kind word. Other clients on social assistance wander down the hall of the Chilkoot Trail Inn to her clinic, or they come in off the street. Word is out and Tulloch is busy. PMID:10025283

  15. 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.

  16. Phase separation and atomic ordering in indium gallium nitride epitaxial layers

    NASA Astrophysics Data System (ADS)

    Rao, Manu

    Phase separation and atomic ordering were investigated in InGaN layers grown by metalorganic chemical vapor deposition on (0001) sapphire substrates. Transmission electron microscopy (TEM) of InGaN layers during their early stages of growth reveal 2-D quantum rings that form spontaneously. In thick layers at InN contents of 3%, planview TEM images show a random distribution of atomic species and selected area diffraction (SAD) patterns do not exhibit satellite spots continuous to Bragg reflections. InN contents of 12% result in a speckled microstructure and satellites are present in SAD patterns. No satellites are observed along the [0001] direction, implying that phase separation is two-dimensional in nature and may occur on the surface while the layer is growing. These results are indicative of composition modulations lying in the (0001) growth plane. Samples containing InN fractions of between 22 and 34% exhibit microstructures having stronger contrast variations and SAD patterns with satellites further spaced from fundamental reflections. In cross-sectional TEM images, contrast striations oriented along [0001] are present except near the InGaN/GaN interface. The spacing of these striations is comparable to the composition modulation wavelengths calculated from SADPs and decreases with increasing InN content. Similarly, plan view TEM images taken from very thin specimens exhibit a domain structure with well aligned stripes within the domains. Increasing the growth rate from 400nm/h to 900nm/h results in a reduction in the intensity of satellite spots, indicating that the amplitude of composition modulations is reduced. The absence of contrast near the InGaN/GaN interface suggest reduced In incorporation, resulting in the absence of phase separation. Reduced In incorporation is confirmed by high angle angular dark field (HAADF) imaging and energy dispersive x-ray spectroscopy (EDS). X-ray diffraction and photoluminescence data are consistent with the occurrence

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Mesoporous InN/In2O3 heterojunction with improved sensitivity and selectivity for room temperature NO2 gas sensing.

    PubMed

    Qu, Fengdong; Liu, Honghong; Guarecuco, Rohiverth; Jiao, Yutong; Yang, Minghui

    2016-09-23

    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. PMID:27514080

  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. 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

  5. Thermodynamic theory of epitaxial alloys: first-principles mixed-basis cluster expansion of (In, Ga)N alloy film

    NASA Astrophysics Data System (ADS)

    Liu, Jefferson Zhe; Zunger, Alex

    2009-07-01

    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.

  6. Investigation of indium gallium nitride facet-dependent nonpolar growth rates and composition for core-shell light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Gîrgel, Ionut; Edwards, Paul R.; Le Boulbar, Emmanuel; Coulon, Pierre-Marie; Sahonta, Suman-Lata; Allsopp, Duncan W. E.; Martin, Robert W.; Humphreys, Colin J.; Shields, Philip A.

    2016-01-01

    Core-shell indium gallium nitride (InGaN)/gallium nitride (GaN) structures are attractive as light emitters due to the large nonpolar surface of rod-like cores with their longitudinal axis aligned along the c-direction. These facets do not suffer from the quantum-confined Stark effect that limits the thickness of quantum wells and efficiency in conventional light-emitting devices. Understanding InGaN growth on these submicron three-dimensional structures is important to optimize optoelectronic device performance. In this work, the influence of reactor parameters was determined and compared. GaN nanorods (NRs) with both {11-20} a-plane and {10-10} m-plane nonpolar facets were prepared to investigate the impact of metalorganic vapor phase epitaxy reactor parameters on the characteristics of a thick (38 to 85 nm) overgrown InGaN shell. The morphology and optical emission properties of the InGaN layers were investigated by scanning electron microscopy, transmission electron microscopy, and cathodoluminescence hyperspectral imaging. The study reveals that reactor pressure has an important impact on the InN mole fraction on the {10-10} m-plane facets, even at a reduced growth rate. The sample grown at 750°C and 100 mbar had an InN mole fraction of 25% on the {10-10} facets of the NRs.

  7. Theoretical study of InN/GaN short period superlattices to mimic disordered alloys

    SciTech Connect

    Ribeiro, M. Marques, M.

    2014-06-14

    We carried out ab initio calculations of the (InN){sub n}∕(GaN){sub m} short period superlattices using the LDA-1/2 method in order to obtain approximate quasiparticle electronic structures. We performed calculations for several short period superlattices respecting the concentrations of 33%, 50%, 66%, and 80% of InN, considering different straining possibilities due to lattice mismatches. For the majority of configurations, we find relevant changes on the valence and conduction profiles around bandgap with position plane-by-plane along the superlattices growth direction, with the presence of intrinsic electric fields in the materials, in the case, when strain is applied. Our results show that for small numbers n and m of layers, the band edge states extend over the entire superlattice. For larger n and/or m, the edge states tend to localise on particular subtype layers (InN or GaN). For the former cases, the bandgaps are very close to the random alloys with the same concentrations, providing potential good materials for optoelectronic devices based on nitrides.

  8. Investigation of facet-dependent InGaN growth for core-shell LEDs

    NASA Astrophysics Data System (ADS)

    Girgel, Ionut; Edwards, Paul R.; Le Boulbar, Emmanuel; Allsopp, Duncan W.; Martin, Robert W.; Shields, Philip A.

    2015-03-01

    In this work we used vertically aligned GaN nanowires with well-defined crystal facets, i.e. the {11-20} a-plane, {10-10} m-plane, (0001) c-plane and {1-101} semi-polar planes, to investigate the impact of MOVPE reactor parameters on the characteristics of an InGaN layer. The morphology and optical characteristics of the InGaN layers grown of each facet were investigated by cathodoluminescence (CL) hyperspectral imaging and scanning electron microscopy (SEM). The influence of reactor parameters on growth rate and alloy fraction were determined and compared. The study revealed that pressure can have an important impact on the incorporation of InN on the {10-10} m-plane facets. The growth performed at 750°C and 100mbar led to a homogeneous high InN fraction of 25% on the {10-10} facets of the nanowires. This work suggests homogeneous good quality GaN/InGaN core-shell structure could be grown in the near future.

  9. Structural and optical characterization of nonpolar (10-10) m-InN/m-GaN epilayers grown by PAMBE

    NASA Astrophysics Data System (ADS)

    Mukundan, Shruti; Chandan, Greeshma; Mohan, Lokesh; Roul, Basanta; Krupanidhi, S. B.

    2016-01-01

    Plasma-assisted molecular beam epitaxy growth of (10-10) m-InN/(10-10) m-GaN was carried out on bare (10-10) m-sapphire substrate. The high resolution X-ray diffraction studies confirmed the orientation of the as-grown films. Nonpolar InN layer was grown at different growth temperatures ranging from 390 °C to 440 °C and the FWHM of rocking curve revealed good quality film at low temperatures. An in-plane relationship was established for the hetrostructures using phi-scan and a perfect alignment was found for the epilayers. Change of morphology of the films grown at different temperatures was observed using an atomic force microscopy technique showing the smoothest film grown at 400 °C. InN optical band gap was found to be vary from 0.79-0.83 eV from absorption spectra. The blue-shift of absorption edge was found to be induced by excess background electron concentration.

  10. The effects of V/III gas ratios on the catalyst-assisted growths of InGaN nanowires

    NASA Astrophysics Data System (ADS)

    Tang, Wei-Che; Hong, Franklin Chau-Nan

    2015-11-01

    Single crystalline InGaN nanowires were grown on Si(1 0 0) using Au catalysts at 700 °C in a plasma-assisted chemical vapor deposition system. Under the low V/III (nitrogen radicals/(Ga + In vapor)) ratio in the gas phase, poor quality InGaN nanowires were grown along [0 0 0 1] orientation (c-axis) containing a high concentration of stacking faults and a low indium content of 12%. However, under the high V/III gas ratio, very high quality InGaN nanowires could be grown along [ 1 0 1 bar 0 ] orientation (m-axis) free of stacking faults containing a high indium content of 24%. The transformation of nanowire orientation was likely due to the decrease of indium and gallium compositions in gold catalysts from >85% to <60% with increasing the V/III gas ratios. Besides, the increase of V/III gas ratios enhanced the incorporation efficiency of indium into the nanowires and significantly improved the crystal quality of nanowires by stabilizing the formation of InN under a high concentration of nitrogen radicals for reversing the fast thermal decomposition reaction of InN at 700 °C.

  11. Fermi level stabilization energy in group III-nitrides

    SciTech Connect

    Li, S.X.; Yu, K.M.; Wu, J.; Jones, R.E.; Walukiewicz, W.; AgerIII, J.W.; Shan, W.; Haller, E.E.; Lu, Hai; Schaff, William J.

    2005-01-07

    Energetic particle irradiation is used to systematically introduce point defects into In{sub 1-x}Ga{sub x}N alloys over the entire composition range. Three types of energetic particles (electrons, protons, and {sup 4}He{sup +}) are used to produce a displacement damage dose spanning five decades. In InN and In-rich InGaN the free electron concentration increases with increasing irradiation dose but saturates at a sufficiently high dose. The saturation is due to Fermi level pinning at the Fermi Stabilization Energy (E{sub FS}), which is located at 4.9 eV below the vacuum level. Electrochemical capacitance-voltage (ECV) measurements show that the pinning of the surface Fermi energy at E{sub FS} is also responsible for the surface electron accumulation in as-grown InN and In-rich InGaN alloys. The results are in agreement with the amphoteric defect model that predicts that the same type of native defects are responsible for the Fermi level pinning in both cases.

  12. Fermi-level stabilization energy in group III nitrides

    SciTech Connect

    Li, S.X.; Jones, R.E.; Haller, E.E.; Yu, K.M.; Wu, J.; Walukiewicz, W.; Ager, J.W. III; Shan, W.; Lu Hai; Schaff, William J.

    2005-04-15

    Energetic particle irradiation is used to systematically introduce point defects into In{sub 1-x}Ga{sub x}N alloys over the entire composition range. Three types of energetic particles (electrons, protons, and {sup 4}He{sup +}) are used to produce a displacement damage dose spanning five decades. In InN and In-rich InGaN the free electron concentration increases with increasing irradiation dose but saturates at a sufficiently high dose. The saturation is due to Fermi level pinning at the Fermi stabilization energy (E{sub FS}), which is located at 4.9 eV below the vacuum level. Electrochemical capacitance-voltage (ECV) measurements show that the pinning of the surface Fermi energy at E{sub FS} is also responsible for the surface electron accumulation in as-grown InN and In-rich InGaN alloys. The results are in agreement with the amphoteric defect model that predicts that the same type of native defects are responsible for the Fermi level pinning in both cases.

  13. Investigation of NH3 input partial pressure for N-polarity InGaN growth on GaN substrates by tri-halide vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Hirasaki, Takahide; Hasegawa, Tomoyasu; Meguro, Misaki; Thieu, Quang Tu; Murakami, Hisashi; Kumagai, Yoshinao; Monemar, Bo; Koukitu, Akinori

    2016-05-01

    The influence of NH3 input partial pressure on N-polarity InGaN grown by tri-halide vapor phase epitaxy was investigated. It was found that surface morphology, solid composition and optical properties were affected by NH3 input partial pressure. As shown in thermodynamic analyses, the indium content increased due to an increase in the driving force for InN deposition caused by increased NH3 input partial pressure. In addition, the deep level emission around 2.1 eV in photoluminescence measurements drastically decreased at higher NH3 input partial pressures. Ab initio calculations and subsequent secondary ion mass spectrometry measurements suggested the reduction of metal-vacancies and/or carbon impurity incorporation in the InGaN layers.

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. Effects of gamma radiation on snake venoms

    NASA Astrophysics Data System (ADS)

    Nascimento, N.; Spencer, P. J.; Andrade, H. F.; Guarnieri, M. C.; Rogero, J. R.

    1998-06-01

    Ionizing radiation is able to detoxify several venoms, including snake venoms, without affecting significantly their immunogenic properties. Inn order to elucidate this phenomena, we conceived a comparative pharmacological study between native and irradiated (2,000 Gy) crotoxin, the main toxin of the South American rattlesnake Crotalus durissus terrificus. Crotoxin was isolated and purified by molecular exclusion chromatography, pI precipitation and, susbequentely submitted to irradiaiton. Gel filtration of the irradiated toxin resulted in some high molecular weight aggregates formation. Crotoxin toxicity decreased two folds after irradiation, as determined by LD 50 in mice. Native and irradiated crotoxin biodistribution ocured in the same general manner, with renal elimination. However, in contrast to irradiated crotoxin, the native form was initially retained in kidneys. A later concentration (2-3 hr) appeared in phagocytic mononuclear cells rich organs (liver and spleen) and neural junction rich organs (muscle and brain).

  1. 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.

  2. Growth of III-Nitrides by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Tang, Liang

    Nitride compound materials are highly desirable for optoelectronic and power device applications due to their unique combinations of material properties. However due to the large lattice mismatches between AlN and GaN(2.5%), and between InN and GaN(11%), growth of nitride devices which contains lattice mismatched multiple quantum well (MQW) structures remains a challenge. In this work the growth of III-Nitride by the MBE method is investigated, covering the growth of AlGaN/GaN Resonant tunneling Diode, the growth of In0.18 Al0.82N that is lattice matched to GaN, and the fabrication of free standing GaN nanomembranes

  3. Time, Energy, and Spatially Resolved TEM Investigations of Defectsin InGaN

    SciTech Connect

    Jinschek, J.R.; Kisielowski, C.

    2005-10-01

    A novel sample preparation technique is reported to fabricate electron transparent samples from devices utilizing a FIB process with a successive wet etching step. The high quality of the obtained samples allows for band gap--and chemical composition measurements of In{sub x}Ga{sub 1-x}N quantum wells where electron beam induced damage can be controlled and shown to be negligible. The results reveal indium enrichment in nanoclusters and defects that cause fluctuations of the band gap energy and can be measured by low loss Electron Energy Spectroscopy with nm resolution. Comparing our time, energy, and spatially resolved measurements of band gap energies, chemical composition, and their related fluctuations with literature data, we find quantitative agreement if the band gap energy of InN is 1.5-2 eV.

  4. 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. PMID:15666504

  5. 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.

  6. Density Functional Theory of Structural and Electronic Properties of III-N Semiconductors

    SciTech Connect

    Guerel, H. Hakan; Akinci, Oezden; Uenlue, Hilmi

    2010-11-01

    In this wok, we present the density functional theory (DFT) calculations of cubic III-N based semiconductors by using the full potential linear augmented plane-wave method plus local orbitals as implemented in the WIEN2k code. Our aim is to predict the pressure effect on structural and electronic properties of III-N binaries and ternaries. Results are given for structural properties (e.g., lattice constant, elastic constants, bulk modulus, and its pressure derivative) and electronic properties (e.g., band structure, density of states, band gaps and band widths) of GaAs, GaN, AlN, and InN binaries and GaAsN ternaries. The proposed model uses GGA exchange-correlation potential to determine band gaps of semiconductors at {Gamma}, L and X high symmetry points of Brillouin zone. The results are found in good agreement with available experimental data for structural and electronic properties of these semiconductors.

  7. Semi-physical neural modeling for linear signal restoration.

    PubMed

    Bourgois, Laurent; Roussel, Gilles; Benjelloun, Mohammed

    2013-02-01

    This paper deals with the design methodology of an Inverse Neural Network (INN) model. The basic idea is to carry out a semi-physical model gathering two types of information: the a priori knowledge of the deterministic rules which govern the studied system and the observation of the actual conduct of this system obtained from experimental data. This hybrid model is elaborated by being inspired by the mechanisms of a neuromimetic network whose structure is constrained by the discrete reverse-time state-space equations. In order to validate the approach, some tests are performed on two dynamic models. The first suggested model is a dynamic system characterized by an unspecified r-order Ordinary Differential Equation (ODE). The second one concerns in particular the mass balance equation for a dispersion phenomenon governed by a Partial Differential Equation (PDE) discretized on a basic mesh. The performances are numerically analyzed in terms of generalization, regularization and training effort. PMID:23275139

  8. Students in the community: an interprofessional student-run free clinic.

    PubMed

    Moskowitz, David; Glasco, Jennifer; Johnson, Brian; Wang, Grace

    2006-06-01

    Students in the Community (SITC) is an interprofessional collaboration of health science students at the University of Washington. SITC runs a weekly free clinic at the Aloha Inn, a transitional housing facility for 70 homeless men and women in downtown Seattle. The focus of this clinic is on health education, chronic disease management, and re-integration of patients into the healthcare infrastructure. SITC serves as a valuable service learning opportunity for students. In addition to direct clinical services, students gain experience in planning health education strategies, community collaboration, and evaluating intervention outcomes. SITC also oversees a lecture and discussion-based elective course at the University of Washington focused on health issues of the homeless community and provides formal teaching which complements the service-learning component of the endeavor. PMID:16777793

  9. 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

  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. 26th JANNAF Airbreathing Propulsion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Fry, Ronald S. (Editor); Gannaway, Mary T. (Editor)

    2002-01-01

    This volume, the first of four volumes, is a collection of 28 unclassified/unlimited-distribution papers which were presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 26th Airbreathing Propulsion Subcommittee (APS) was held jointly with the 38th Combustion Subcommittee (CS), 20th Propulsion Systems Hazards Subcommittee (PSHS), and 2nd Modeling and Simulation Subcommittee. The meeting was held 8-12 April 2002 at the Bayside Inn at The Sandestin Golf & Beach Resort and Eglin Air Force Base, Destin, Florida. Topics covered include: scramjet and ramjet R&D program overviews; tactical propulsion; space access; NASA GTX status; PDE technology; actively cooled engine structures; modeling and simulation of complex hydrocarbon fuels and unsteady processes; and component modeling and simulation.

  12. 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.

  13. 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.

  14. 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.

  15. Leakage Current Mechanism of InN-Based Metal-Insulator-Semiconductor Structures with Al2O3 as Dielectric Layers.

    PubMed

    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

    2016-12-01

    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/cm(2) 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. PMID:26759357

  16. Development of green, yellow, and amber light emitting diodes using InGaN multiple quantum well structures

    NASA Astrophysics Data System (ADS)

    Barletta, Philip T.; Acar Berkman, E.; Moody, Baxter F.; El-Masry, Nadia A.; Emara, Ahmed M.; Reed, Mason J.; Bedair, S. M.

    2007-04-01

    The authors present optical and electrical data for long wavelength (573-601nm) InGaN /GaN multiple quantum well light emitting diodes (LEDs) grown by metal organic chemical vapor deposition. These results are achieved by optimizing the active layer growth temperature and the quantum well width. Also, the p-GaN is grown at low temperature to avoid the disintegration of the InGaN quantum wells with high InN content. A redshift is observed for both the green and yellow LEDs upon decreasing the injection current at low current regime. In the case of the yellow LED, this shift is enough to push emission into the amber (601nm ).

  17. Prospects and challenges of InN-based nanowire heterostructures and devices integrated on Si

    NASA Astrophysics Data System (ADS)

    Mi, Z.; Nguyen, H. P. T.; Cui, K.; Han, X.; Zhang, S.; Chang, Y.-L.

    2010-10-01

    We report on the molecular beam epitaxial growth and characterization of In(Ga)N nanowires on Si(111) substrates. We also describe the growth and optical properties of InGaN/GaN dot-in-a-wire heterostructures on Si(111) substrates with emission in the green, yellow, and red wavelength range. The design, fabrication, and characterization of In(Ga)N nanowire solar cells and LEDs are discussed. InN p-i-n axial nanowire homojunction solar cells exhibit a promising short-circuit current density of ~ 14.4 mA/cm2 and an energy conversion efficiency of ~ 0.68% under 1-sun, AM1.5G illumination. Strong green, yellow, and amber emission has also been achieved from InGaN/GaN dot-in-a-wire LEDs at room temperature.

  18. Effect of polarization field on mean free path of phonons in indium nitride

    NASA Astrophysics Data System (ADS)

    Sahoo, Sushant Kumar

    2016-05-01

    The effect of built-in-polarization field on mean free path of acoustic phonons in bulk wurtzite indium nitride (InN) has been theoretically investigated. The elastic constant of the material gets modified due to the existence of polarization field. As a result velocity and Debye frequency of phonons get enhanced. The various scattering rates of phonons are suppressed by the effect of polarization field, which implies an enhanced combined relaxation time. Thus phonons travel freely for a longer distance between two successive scatterings. This would enhance the thermal transport properties of the material when built-in-polarization field taken into account. Hence by the application of electric field the transport properties of such materials can be controlled as and when desired.

  19. The role of neuropeptide F in a transition to parental care.

    PubMed

    Cunningham, Christopher B; VanDenHeuvel, Kathryn; Khana, Daven B; McKinney, Elizabeth C; Moore, Allen J

    2016-04-01

    The genetics of complex social behaviour can be dissected by examining the genetic influences of component pathways, which can be predicted based on expected evolutionary precursors. Here, we examine how gene expression in a pathway that influences the motivation to eat is altered during parental care that involves direct feeding of larvae. We examine the expression ofneuropeptide F, and its receptor, in the burying beetleNicrophorus vespilloides, which feeds pre-digested carrion to its begging larvae. We found that thenpfreceptorwas greatly reduced during active care. Our research provides evidence that feeding behaviour was a likely target during the evolution of parental care inN. vespilloides Moreover, dissecting complex behaviours into ethologically distinct sub-behaviours is a productive way to begin to target the genetic mechanisms involved in the evolution of complex behaviours. PMID:27095268

  20. Indium Incorporation in InxGa1-xN/GaN Nanowire Heterostructures Investigated by Line-of-Sight Quadrupole Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Wölz, M.; Fernández-Garrido, S.; Hauswald, C.; Brandt, O.; Limbach, F.; Geelhaar, L.; Riechert, H.

    2012-10-01

    We investigate the formation of the ternary alloy InxGa1-xN in the growth of self-induced nanowires by plasma-assisted molecular beam epitaxy. A series of samples grown at different temperatures were analyzed in situ by line-of-sight quadrupole mass spectrometry, and the predicted composition was verified by X-ray diffraction on as-grown nanowire ensembles. The InxGa1-xN composition is determined by the thermally activated loss of In due to InN decomposition and In desorption, similar to the composition of planar layers. The convolution of decomposition, reincorporation, and desorption is described by an apparent activation energy of about 2.5 eV. We show the feasibility of in situ control of the InxGa1-xN nanowire composition by line-of-sight quadrupole mass spectrometry.

  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. 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.

  3. Optical properties of plasma-assisted molecular beam epitaxy grown InN/sapphire

    NASA Astrophysics Data System (ADS)

    Talwar, Devki N.; Liao, Ying Chieh; Chen, Li Chyong; Chen, Kuei Hsien; Feng, Zhe Chuan

    2014-11-01

    The optical properties of as-grown InN/sapphire films prepared by plasma assisted molecular beam epitaxy (PA-MBE) are characterized by photoluminescence (PL), Raman scattering (RS) and infrared (IR) reflectance techniques. The PL measurements have consistently exhibited lower values of InN band gaps providing clear indications of electron concentration dependent peak energy shifts and widths. The phonon modes identified by RS are found to be in good agreement with the grazing inelastic X-ray scattering measurements and ab initio lattice dynamical calculations. An effective medium theory used to analyze IR reflectance spectra of InN/sapphire films has provided reasonable estimates of free charge carrier concentrations.

  4. 6th COSTAM/SFRR (ASEAN/Malaysia) International Workshop on Micronutrients, Oxidative Stress, and the Environment.

    PubMed

    Nesaretnam, Kalanithi; Sies, Helmut

    2006-01-01

    The 6(th) COSTAM/SFRR (ASEAN/Malaysia) workshop, "Micronutrients, Oxidative Stress, and the Environment," was held from June 29 to July 2 at Holiday Inn Damai Beach Resort in Kuching, Sarawak. Two hundred twenty participants from 17 countries presented recent advances on natural antioxidants in the area of oxidative stress and molecular aspects of nutrition. Natural products and research are an important program in academic institutions and are experiencing unprecedented interest and growth by the scientific community and public health authorities. Progress is being driven by better understanding of the molecular mechanisms of the relation between oxidative stress and micronutrient action. The gathering of scientists from around the world was fruitful, and we hope that future work will be developed by the formal and informal interactions that took place in this beautiful tropical setting. PMID:17034360

  5. 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.

  6. 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.

  7. Occupancy sensors for HVAC gaining in hotel industry

    SciTech Connect

    Ladd, C.

    1985-12-02

    The hotel industry is overcoming its skepticism as occupancy sensors with built-in thermistors to control heating, ventilating, and air conditioning (HVAC) units demonstrate their ability to cut energy costs as much as 30%. Despite the successful demonstrations and acceptance by Holiday Inn, some hotel managers of other chains continue to resist. Occupancy sensors have either ultrasonic or infrared signals, but differ from lighting control devices by also having internal thermistors and remote door switches. This allows the rooms to reach comfort levels only when the guest is present since occupants are only minimally affected if temperatures are modified during unoccupied periods. The system works best for roadside-type motels rather than convention hotels, where occupants are in and out of their rooms.

  8. 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.

  9. 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.

  10. Chemistry and physics of coal utilization - 1980

    SciTech Connect

    Cooper, B.R.; Petrakis, L.

    1981-01-01

    The Conference on the Chemistry and Physics of Coal Utilization was designed as an interdisciplinary conference centered on the physics and chemistry phenomena involved in coal utilization, including the chemistry and physics of coal itself. The Conference was designated as a Topical Conference of the American Physical Society, and was held on June 2-4, 1980, at the Lakeview Inn in Morgantown, West Virginia. It was primarily intended as a working conference for those already engaged in, or at least technically informed on, coal conversion and utilization research. The program consisted of lectures by 23 invited speakers and two panel discussions by invited experts. In addition there were two sessions at which a total of 49 poster contributions were presented. This volume contains the invited papers (with one exception), reports of the panel discussions, and abstracts for the poster contributions. The individual papers are entered individually into EDB from a tape prepared by the American Institute of Physics. (LTN)

  11. 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

  12. 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.

  13. 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."

  14. 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.

  15. 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.

  16. 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.

  17. Carolinas HealthCare attends to patients, amenities; builds business.

    PubMed

    Rees, T

    2000-01-01

    Carolinas HealthCare System has grown into a nearly two billion dollar entity by focusing on patient needs and amenities in its health care facilities. Growth of the system, the largest in North and South Carolina, is due in large part to Harry A. Nurkin, president and CEO, who started out with a run-down hospital for indigents. With the approval of the hospital board, Nurkin launched a marketing effort that included taking a lesson from the founders of the Holiday Inn hotel chain. He remodeled and developed facilities that are pleasing to patients and visitors, moved patient parking closer to the hospitals' front doors, taught key hospital personnel the basics about marketing, aligned the system with ABA and NFL teams and conducted an aggressive advertising program. PMID:11143133

  18. 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.

  19. Court lets hotel guest keep $250,000 award for needlestick.

    PubMed

    1998-08-01

    [Name removed], a guest at the Dollar Inn in September 1988, was stabbed in the thumb by a hypodermic needle hidden in a roll of toilet paper. Told by a hotel employee that the needle was probably left by an injection-drug user on staff, [name removed] went to a hospital for blood tests. Hospital staff erroneously informed [name removed] that she would need testing for HIV for the next 10 years. In 1990, [name removed] sued the hotel and in 1997 was awarded $250,000. The Indiana Court of Appeals upheld the award, refusing to accept the "actual exposure" test defense, which requires a plaintiff to prove that the needle was contaminated by HIV or that the person who had used the needle is HIV-positive. PMID:11365664

  20. Surging as a potential response of ice sheets to CO/sub 2/-induced changes in the polar environment (SPICAE). Progress report, January 1-August 31, 1984

    SciTech Connect

    Radok, U.

    1984-08-01

    This progress report covers the work accomplished during the first eight months of Project SPICAE. The project has two major parts, concerned respectively with basic and surging dynamics of ice sheets. In the first part, preliminary estimates of important physical characteristics have been obtained for the West Antarctic Ross Ice Shelf Basin (WARISB), assuming it to be in steady-state balance. Flowline calculations have been carried out for a cross section through West Antarctica to establish the equilibrium states of two major ice streams for their current mass balances as well as for drastically altered regimes. Work on surging dynamics in the second part of the project has involved the delineation of parameter regions in the Budd-McInnes model which correspond to cyclic surging and steady-state fast sliding, respectively, of the two ice streams mentioned earlier. 12 references, 8 figures.

  1. Composition control of InN/WO3 nanocomposite by in-situ reactive plasma annealing

    NASA Astrophysics Data System (ADS)

    Saroni, Azianty; Goh, Boon Tong; Alizadeh, Mahdi; Rahman, Saadah Abdul

    2016-05-01

    A composition control and formation of InN/WO3 nanocomposite on the as-grown In2O3 by in-situ reactive plasma annealing was investigated. The reactive plasma annealing changes the facets crystalline In2O3 structure to nanograin structure of InN/WO3 nanocomposite with the grain size of 100-200 nm. X-ray photoelectron spectroscopy (XPS) reveals the formation of In2O3, InN and WO3 nanostructures in the nanocomposite. In-situ reactive plasma annealing enhances the removing of In2O3 and facilitates the formation of InN/WO3 nanocomposite. Furthermore, the reduction of oxygen in In2O3 leads to a decreasing in optical energy gap from 2.91 to 2.63 eV.

  2. Characterization of MBE-grown InAlN/GaN heterostructure valence band offsets with varying In composition

    NASA Astrophysics Data System (ADS)

    Jiao, Wenyuan; Kong, Wei; Li, Jincheng; Collar, Kristen; Kim, Tong-Ho; Losurdo, Maria; Brown, April S.

    2016-03-01

    Angle-resolved X-ray photoelectron spectroscopy (XPS) is used in this work to experimentally determine the valence band offsets of molecular beam epitaxy (MBE)-grown InAlN/GaN heterostructures with varying indium composition. We find that the internal electric field resulting from polarization must be taken into account when analyzing the XPS data. Valence band offsets of 0.12 eV for In0.18Al0.82N, 0.15 eV for In0.17Al0.83N, and 0.23 eV for In0.098Al0.902N with GaN are obtained. The results show that a compositional-depended bowing parameter is needed in order to estimate the valence band energies of InAlN as a function of composition in relation to those of the binary endpoints, AlN and InN.

  3. Overlap population diagram for ELNES and XANES: peak assignment and interpretation

    NASA Astrophysics Data System (ADS)

    Mizoguchi, Teruyasu

    2009-03-01

    This article reviews overlap population (OP) diagrams for electron energy loss near-edge structure (ELNES) and x-ray absorption near-edge structure (XANES). By using the OP diagrams, peaks in ELNES and XANES of MgO, ZnO, AlN, GaN, InN, and YBa2Cu3O7-x are interpreted in terms of cation-anion and cation-cation interactions. Common features are found in the OP diagrams for different edges. A reconstruction of the unoccupied electronic structure is demonstrated by aligning the different edges with the common features in the OP diagrams. The OP diagram is also applied to the Cu/Al2O3 hetero-interface to find the relationships among ELNES, atomic and electronic structures, and properties.

  4. 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}.

  5. Optoelectronic and structural properties of InGaN nanostructures grown by plasma-assisted MOCVD

    NASA Astrophysics Data System (ADS)

    Seidlitz, Daniel; Senevirathna, M. K. I.; Abate, Y.; Hoffmann, A.; Dietz, N.

    2015-09-01

    This paper presents optoelectronic and structural layer properties of InN and InGaN epilayers grown on sapphire templates by Migration-Enhanced Plasma Assisted Metal Organic Chemical Vapor Deposition (MEPA-MOCVD). Real-time characterization techniques have been applied during the growth process to gain insight of the plasma-assisted decomposition of the nitrogen precursor and associated growth surface processes. Analyzed Plasma Emission Spectroscopy (PES) and UV Absorption Spectroscopy (UVAS) provide detection and concentrations of plasma generated active species (N*/NH*/NHx*). Various precursors have been used to assess the nitrogen-active fragments that are directed from the hollow cathode plasma tube to the growth surface. The in-situ diagnostics results are supplemented with ex-situ materials structures investigation results of nanoscale structures using Scanning Near-field Optical Microscopy (SNOM). The structural properties have been analyzed by Raman spectroscopy and Fourier transform infrared (FTIR) reflectance. The Optoelectronic and optical properties were extracted by modeling the FTIR reflectance (e.g. free carrier concentration, high frequency dielectric constant, mobility) and optical absorption spectroscopy. The correlation and comparison between the in-situ metrology results with the ex-situ nano-structural and optoelectronic layer properties provides insides into the growth mechanism on how plasma-activated nitrogen-fragments can be utilized as nitrogen precursor for group III-nitride growth. The here assessed growth process parameter focus on the temporal precursor exposure of the growth surface, the reactor pressure, substrate temperature and their effects of the properties of the InN and InGaN epilayers.

  6. MBE Grown In x Ga1- x N Thin Films with Bright Visible Emission Centered at 550 nm

    NASA Astrophysics Data System (ADS)

    Dasari, K.; Thapa, B.; Wang, J.; Wright, J.; Kaya, S.; Jadwisienczak, W. M.; Palai, R.

    2016-04-01

    The In x Ga1- x N thin films with indium content of x = 14-18 at.% were successfully grown by using molecular beam epitaxy (MBE) at high growth temperatures from 650°C to 800°C. In situ reflection high-energy electron diffraction (RHEED) of the In x Ga1- x N films confirmed the Stranski-Krastanov growth mode. X-ray diffraction (XRD) of the films confirmed their highly crystalline nature having c-axis orientation with a small fraction of secondary InN phase admixture. High-resolution cross-sectional scanning electron microscopy images showed two-dimensional epilayers growth with thickness of about ˜260 nm. The high growth temperature of In x Ga1- x N epilayers is found to be favorable to facilitate more GaN phase than InN phase. All the fundamental electronic states of In, Ga, and N were identified by x-ray photoelectron spectroscopy (XPS) and the indium composition has been calculated from the obtained XPS spectra with CASAXPS software. The composition calculations from XRD, XPS and photoluminescence closely match each other. The biaxial strain has been calculated and found to be increasing with the In content. Growing In x Ga1- x N at high temperatures resulted in the reduction in stress/strain which affects the radiative electron-hole pair recombination. The In x Ga1- x N film with lesser strain showed a brighter and stronger green emission than films with the larger built-in strain. A weak S-shaped near band edge emission profile confirms the relatively homogeneous distribution of indium.

  7. 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

  8. 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.

  9. 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

  10. Ab initio electronic transport model with explicit solution to the linearized Boltzmann transport equation

    NASA Astrophysics Data System (ADS)

    Faghaninia, Alireza; Ager, Joel W.; Lo, Cynthia S.

    2015-06-01

    Accurate models of carrier transport are essential for describing the electronic properties of semiconductor materials. To the best of our knowledge, the current models following the framework of the Boltzmann transport equation (BTE) either rely heavily on experimental data (i.e., semiempirical), or utilize simplifying assumptions, such as the constant relaxation time approximation (BTE-cRTA). While these models offer valuable physical insights and accurate calculations of transport properties in some cases, they often lack sufficient accuracy—particularly in capturing the correct trends with temperature and carrier concentration. We present here a transport model for calculating low-field electrical drift mobility and Seebeck coefficient of n -type semiconductors, by explicitly considering relevant physical phenomena (i.e., elastic and inelastic scattering mechanisms). We first rewrite expressions for the rates of elastic scattering mechanisms, in terms of ab initio properties, such as the band structure, density of states, and polar optical phonon frequency. We then solve the linear BTE to obtain the perturbation to the electron distribution—resulting from the dominant scattering mechanisms—and use this to calculate the overall mobility and Seebeck coefficient. Therefore, we have developed an ab initio model for calculating mobility and Seebeck coefficient using the Boltzmann transport (aMoBT) equation. Using aMoBT, we accurately calculate electrical transport properties of the compound n -type semiconductors, GaAs and InN, over various ranges of temperature and carrier concentration. aMoBT is fully predictive and provides high accuracy when compared to experimental measurements on both GaAs and InN, and vastly outperforms both semiempirical models and the BTE-cRTA. Therefore, we assert that this approach represents a first step towards a fully ab initio carrier transport model that is valid in all compound semiconductors.

  11. 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.

  12. 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

  13. 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.

  14. Is the pharmaceutical market in Bulgaria innovative?

    PubMed

    Stoimenova, A; Stankova, M; Samev, K; Petrova, G

    2003-09-01

    After the turn to market oriented economy a lot of drugs were authorized for sale in the East European countries. Because of the limited resources of these countries, mainly generic or brand generic products were licensed. The number of the patented drugs on the market could be used as measure of the market attractiveness to the R&D producers. The study shows the analysis of the innovativeness of the Bulgarian drug market comparing the registration and the patient activity of the producers. The number of the authorized products for five years period (1990-2000) and share of the patented products were investigated. During the observed period the number of newly authorized pharmaceuticals increased almost seven times from 800 (650 INN) to 6000 (2000 INN) dosage forms. The prevailing part of the newly registered drugs was found to be brand generics and possess only trade name protection. The share of drugs that are patented is less than five percent of all newly registered medicines, and among the fifty most commonly prescribed and sold medicines between 1996-2000, only 0.5 percent of drugs were patented. Obviously the Bulgarian pharmaceutical market is very competitive but not that attractive for most of the R&D producers. In general the registration of the patent protected products is increasing during the years and especially after harmonization of the related legislation with the EU requirements. The patent activity of the pharmaceutical companies regarding newly authorized drugs is influenced by the structure of morbidity and population. During the last two years the patent activity is increasing and is oriented mainly towards the protection of newly authorized drugs or pharmaceutical forms and obligatory registration of trademarks for the privatized Bulgarian pharmaceutical manufacturers. PMID:14677267

  15. 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.

  16. Dolutegravir-Selected HIV-1 Containing the N155H and R263K Resistance Substitutions Does Not Acquire Additional Compensatory Mutations under Drug Pressure That Lead to Higher-Level Resistance and Increased Replicative Capacity

    PubMed Central

    Anstett, Kaitlin; Fusco, Robert; Cutillas, Vincent; Mesplède, Thibault

    2015-01-01

    ABSTRACT We have previously shown that the addition of the raltegravir/elvitegavir (RAL/EVG) primary resistance mutation N155H to the R263K dolutegravir (DTG) resistance mutation partially compensated for the fitness cost imposed by R263K while also slightly increasing DTG resistance in vitro (K. Anstett, T. Mesplede, M. Oliveira, V. Cutillas, and M. A. Wainberg, J Virol 89:4681–4684, 2015, doi:10.1128/JVI.03485-14). Since many patients failing RAL/EVG are given DTG as part of rescue therapy, and given that the N155H substitution often is found in combination with other compensatory resistance mutations in such individuals, we investigated the effects of multiple such substitutions within integrase (IN) on each of integrase function, HIV-1 infectivity, and levels of drug resistance. To this end, each of the L74M, E92Q, T97A, E157Q, and G163R substitutions were introduced into NL4.3 subtype B HIV-1 vectors harboring N155H and R263K in tandem [termed NL4.3IN(N155H/R263K)]. Relevant recombinant integrase enzymes also were expressed, and purified and biochemical assays of strand transfer efficiency as well as viral infectivity and drug resistance studies were performed. We found that the addition of T97A, E157Q, or G163R somewhat improved the affinity of INN155H/R263K for its target DNA substrate, while the presence of L74M or E92Q had a negative effect on this process. However, viral infectivity was significantly decreased from that of NL4.3IN(N155H/R263K) after the addition of each tertiary mutation, and no increases in levels of DTG resistance were observed. This work shows that the compensatory mutations that evolve after N155H under continued DTG or RAL/EVG pressure in patients are unable to improve either enzyme efficiency or viral infectivity in an N155H/R263K background. IMPORTANCE In contrast to other drugs, dolutegravir has not selected for resistance in HIV-positive individuals when used in first-line therapy. We had previously shown that HIV containing

  17. Molecular beam epitaxy growth of indium nitride and indium gallium nitride materials for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Trybus, Elaissa

    The objective of the proposed research is to establish the technology for material growth by molecular beam epitaxy (MBE) and fabrication of indium gallium nitride/gallium nitride (InxGa1-xN/GaN) heterojunction solar cells. InxGa1-xN solar cells have the potential to span 90% of the solar spectrum, however there has been no success with high indium (In) incorporation and only limited success with low In incorporation InxGa1-xN. Therefore, this present work focuses on 15--30% In incorporation leading to a bandgap value of 2.3--2.8 eV. This work will exploit the revision of the indium nitride (InN) bandgap value of 0.68 eV, which expands the range of the optical emission of nitride-based devices from ultraviolet to near infrared regions, by developing transparent In xGa1-xN solar cells outside the visible spectrum. Photovoltaic devices with a bandgap greater than 2.0 eV are attractive because over half the available power in the solar spectrum is above the photon energy of 2.0 eV. The ability of InxGa1-xN materials to optimally span the solar spectrum offers a tantalizing solution for high-efficiency photovoltaics. This work presents results confirming the revised bandgap of InN grown on germanium (Ge) substrates and the effects of oxygen contamination on the bandgap. This research adds to the historical discussion of the bandgap value of InN. Using the metal modulated epitaxy (MME) technique in a new, ultra-clean refurbished MBE system, an innovative growth regime is established where In and Ga phase separation is diminished by increasing the growth rate for In xGa1-xN. The MME technique modulates the metal shutters with a fixed duty cycle while maintaining a constant nitrogen flux and proves effective for improving crystal quality and p-type doping. InxGa 1-xN/GaN heterojunction solar cells require p-type doping to create the p-n subcell collecting junction, which facilitates current collection through the electrostatic field created by spatially separated ionized

  18. 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

  19. 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

  20. 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