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Sample records for ramada inn clemson

  1. 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

  2. Clemson University Balances Growth with Focus

    ERIC Educational Resources Information Center

    Fain, Paul

    2008-01-01

    Colleges are fond of issuing proclamations filled with ambitious goals. So Clemson University was hardly charting new territory in 2001 when its Board of Trustees endorsed 27 goals to make it a top-20 public research university. Less than two years later, Clemson achieved one of those benchmarks by exceeding $100-million per year in research…

  3. 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

  4. 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…

  5. Electronic Proposal Processing at Clemson University.

    ERIC Educational Resources Information Center

    Latimer, Dewitt A.; McCracken, Alden L.

    1988-01-01

    Office automation technology is being used to process proposals at Clemson University. The Electronic Proposal Submittal project is a process by which the Principal Investigator can create a proposal at his or her local station and electronically submit it for processing. (Author/MLW)

  6. 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

  7. Proceedings of the Clemson Conference on Language and International Trade (Clemson, South Carolina, March 9-11, 1989).

    ERIC Educational Resources Information Center

    King, S. Carl, Ed.; Torres, Sixto E., Ed.

    Eleven papers cover the Language and International Trade Program at Clemson University, similar foreign language programs at other universities, and the role of government funding in the development of such programs. The papers include the following: (1) "The Language and International Trade Program at Clemson University: Remarks on Program Impact…

  8. Implementing a Peer Mentoring Model in the Clemson Eportfolio Program

    ERIC Educational Resources Information Center

    Ring, Gail L.

    2015-01-01

    Since the implementation of the ePortfolio Program in 2006, Clemson University has incorporated peer review for the formative feedback process. One of the challenges with this large-scale implementation has been ensuring that all work is reviewed and constructive feedback is provided in a timely manner. In this article, I discuss the strategies…

  9. The Language & International Trade Program at Clemson University.

    ERIC Educational Resources Information Center

    Suarez, Jose I.

    Clemson University (South Carolina) has developed an undergraduate Language and International Trade program designed to train students to meet the needs of American firms doing business overseas. Program aims are that graduates know one foreign language, be attuned to cultural differences, have a business training foundation, and have experience…

  10. 76 FR 54690 - Amendment of Class E Airspace; Clemson, SC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... E airspace at Clemson, SC (76 FR 38582) Docket No. FAA-2011-0394. Interested parties were invited to... Executive Order 12866; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR.... 106(g); 40103, 40113, 40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec. 71.1 0...

  11. 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

  12. 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

  13. 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

  14. 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

  15. Gonadal disorder in the thinlip grey mullet (Liza ramada, Risso 1827) as a biomarker of environmental stress in surface waters.

    PubMed

    Tancioni, Lorenzo; Caprioli, Riccardo; Al-Khafaji, Ayad Hantoosh Dawood; Mancini, Laura; Boglione, Clara; Ciccotti, Eleonora; Cataudella, Stefano

    2015-02-01

    The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas. PMID:25664693

  16. Gonadal Disorder in the Thinlip Grey Mullet (Liza ramada, Risso 1827) as a Biomarker of Environmental Stress in Surface Waters

    PubMed Central

    Tancioni, Lorenzo; Caprioli, Riccardo; Dawood Al-Khafaji, Ayad Hantoosh; Mancini, Laura; Boglione, Clara; Ciccotti, Eleonora; Cataudella, Stefano

    2015-01-01

    The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas. PMID:25664693

  17. Metal partitioning and availability in estuarine surface sediments: Changes promoted by feeding activity of Scrobicularia plana and Liza ramada

    NASA Astrophysics Data System (ADS)

    Pedro, Sílvia; Duarte, Bernardo; Reis, Givaldo; Pereira, Eduarda; Duarte, Armando C.; Costa, José Lino; Caçador, Isabel; Almeida, Pedro Raposo de

    2015-12-01

    Several works have evidenced in the past the importance and influence of plants and terrestrial invertebrates in metal availability in soils and sediments through changes in metal speciation. In contrast, the impact of estuarine invertebrates and fishes in this process has been poorly explored. The partition of metals in estuarine surface sediments was studied in a controlled environment according to four operationally defined fractions. Sediments were analyzed before and after the passage through the gut of two detritivorous species. Scrobicularia plana feeds on the bottom and suspended sediment particles through the inhalant siphon. Liza ramada is an interface feeder, filtering the superficial layer of the sediment and suspended particles in the water column. Cd, Cu and Ni bound to carbonates increased in the pellets of S. plana, compared with the ingested sediment, as did exchangeable Zn. Similarly, Cd and Zn bound to carbonates have also increased in the pellets of L. ramada; on the contrary, a decrease of Ni was observable in the pellets of this fish. The outcome of the controlled experiments pointed to a potential increase in some metals' availability in the estuarine environment, as a result of the more mobile metal forms in the excreted fecal pellets. This draws the attention to a relevant impact of the trophic activity of both species, alongside with the potential enhancement brought to it by the bioturbation promoted by them, in the role that the estuary itself has as a contaminants' buffer.

  18. Feeding ecology of Liza ramada (Risso, 1810) (Pisces, Mugilidae) in a south-western estuary of Portugal

    NASA Astrophysics Data System (ADS)

    Almeida, P. R.

    2003-05-01

    The feeding activity of the Liza ramada population inhabiting the Mira estuary (Portugal) is reduced during the winter and summer months. At the beginning of the spawning migration (i.e. November) an increase in the amount of food ingested was noticed. In the upper estuary, the feeding behaviour is independent of the tidal cycle, although there is some evidence of a daily rhythm in the food consumption rate, with a reduction during the night. No significant correlation was found between the quantity of particulate organic matter and the concentration of microalgae present in the stomach contents, and it seems that the bulk of the organic matter ingested by the thin-lipped grey mullets comes from a different origin than planktonic or benthic microalgae. The L. ramada population showed a positive selection for sediment particles between 55 and 250 μm in diameter. In general, the diet composition of this species showed a low diversity of food items. A total of 52 food items were identified in the stomach contents, the Bacillariophyceae being the dominant group. The genera Melosira and Ciclotella were the most common and abundant food items, although the genera Navicula, Nitzschia and Surirella were also classified as preferential food items. It was found that the volume of ploughed sediment that resulted from the feeding activity of the thin-lipped grey mullets, and the correspondent disturbed area increased exponentially with the length of the fish.

  19. 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.

  20. Investigating the Use of Design Methods by Capstone Design Students at Clemson University

    ERIC Educational Resources Information Center

    Miller, W. Stuart; Summers, Joshua D.

    2013-01-01

    The authors describe a preliminary study to understand the attitude of engineering students regarding the use of design methods in projects to identify the factors either affecting or influencing the use of these methods by novice engineers. A senior undergraduate capstone design course at Clemson University, consisting of approximately fifty…

  1. Astronaut Joins Clemson to Promote the Value of Integrative STEM Education

    ERIC Educational Resources Information Center

    Technology and Engineering Teacher, 2013

    2013-01-01

    NASA and astronaut Patrick Forrester recently teamed up with Clemson University's College of Health Education and Human Development (HEHD) to promote STEM teaching and learning in the Upstate (SC) community. A goal of HEHD is to extend integrative STEM education opportunities to all teachers and their students in South Carolina. NASA space…

  2. Prospects for the Faculty Labor Market in the 1990s: A Clemson University Perspective.

    ERIC Educational Resources Information Center

    Ulbrich, Holley

    Through a faculty retirement survey and a review of the literature, Clemson University, South Carolina, studied the future labor market for college faculty. The survey was administered to 1,250 faculty at the university in Fall, 1991. Fifty-six responded with data indicating that the College of Sciences, and the College of Agricultural Sciences…

  3. 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.

  4. 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 ...

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Kudoa unicapsula n. sp. (Myxosporea: Kudoidae) a parasite of the Mediterranean mullets Liza ramada and L. aurata (Teleostei: Mugilidae).

    PubMed

    Yurakhno, V M; Ovcharenko, M O; Holzer, A S; Sarabeev, V L; Balbuena, J A

    2007-11-01

    A new multivalvulid myxozoan parasite, Kudoa unicapsula n. sp., is described from the intestinal mesentery, intestine and pyloric caeca of the thin-lipped grey mullet Liza ramada (Risso 1826) and the golden grey mullet L. aurata (Risso, 1810) from the Mediterranean coastal waters of Spain. It is characterized by the presence of elongated, rice corn-like white cysts of 0.47-0.56 x 0.18-0.38 mm, filled with tetracapsulate, slightly asymmetric spores, rectangular in apical view and tear-shaped in lateral view with four polar capsules of considerably different size and slightly unequal spore valves with rounded edges, overlapping each other on the apex of the spore. One large polar capsule includes a polar filament coiled in two to three turns, and the other three polar capsules, which are very small, posses only a rudimental filament. Both light and electron microscopy data showed that this species differs from all previously described Kudoa spp. with unequal polar capsules. The molecular analysis based on 18S and 28S ribosomal deoxyribonucleic acid DNA sequence data of K. unicapsula n. sp. indicates a close relationship and thus phylogenetic clustering together with K. trifolia, a myxozoan from the same host and the same geographical location. PMID:17846792

  10. 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.

  11. Research and education on fiber-based materials for nanofluidics at Clemson University

    NASA Astrophysics Data System (ADS)

    Kornev, Konstantin G.

    2007-11-01

    Advanced materials and the science and engineering related to their design, process, test and manufacture represents one of the fast growing sectors of the Materials Science and Engineering field. Awareness of existing process, performance, manufacturing or recycle-ability issues and limitations, often dictates the next generation of advances needed to improve existing or create new materials. To compete in this growing science and technology area, trained experts must possess strong academic skills in their discipline as well as advanced communication, networking and cultural teamwork experience. Clemson's School of Materials Science and Engineering (MSE), is continuing to expand our program to focus on unique capabilities which support local, regional and national needs in advanced materials. Specifically, MSE at Clemson is evolving to highlight intrinsic strengths in research and education areas related to optical materials, advanced fibers and composites (based on inorganic, organic and natural fibers), biomaterials and devices, and architectural and restoration material science (including the conservation and preservation of maritime structures). Additionally, we continue to invest in our expertise in materials design and fabrication, which has historically supported our well known programs in ceramics and textiles. In addition to a brief review of the School's forward-looking challenges to remain competitive among strong southeast regional materials science programs, this presentation will also highlight recent technical advances in fiber-based materials for nanofluidic applications. Specifically we will present recent results on design of fiber-based nanofluidics for sensor applications and we will discuss some physical phenomena associated with liquid transport at nanoscale.

  12. 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.

  13. 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.

  14. 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 ...

  15. Stabilize ash using Clemson`s sintering process (Part 1 -- Phase 1 results): Mixed waste fly ash stabilization. Innovative technology summary report

    SciTech Connect

    Not Available

    1998-12-01

    Incineration of applicable Department of Energy (DOE) mixed wastes has produced a secondary waste stream of radioactive and Resource Conservation and Recovery Act (RCRA) hazardous fly ash that also requires treatment before land disposal. Unlike bottom ash, fly ash usually contains constituents making efficient stabilization difficult. For example, fly ash from the DOE Waste Experimental Reduction Facility (WERF) incinerator at the Idaho National Engineering and Environmental Laboratory (INEEL) contains volatile metals, metal salts, high concentrations of zinc, and unburned organic residues. All of these constituents can effect the stabilization process. The Department of Energy, and in particular the Mixed Waste Focus Area (MWFA) of EM-50, has stated the need for improved stabilization methods would accept a higher ash waste loading while meeting waste form disposal criteria. These alternative stabilization technologies should include delivery systems to minimize worker exposure and minimize secondary waste generation, while maximizing operational flexibility and radionuclide containment. Currently, the standard practice for stabilizing ash is mixing with Portland cement at room temperature. This standard practice produces a significant increase of waste material volume or has difficulty in adequately stabilizing the components in the fly ash to ensure regulatory requirements are consistently satisfied. To address these fly ash stabilization shortcomings, the MWFA, a DOE/EM-50 program, invested in the development of several fly ash stabilization alternatives, including the Clemson University sintering method.

  16. Genetic detection and multilocus sequence typing of vanA-containing Enterococcus strains from mullets fish (Liza ramada).

    PubMed

    Araújo, Carlos; Torres, Carmen; Gonçalves, Alexandre; Carneiro, Catarina; López, Maria; Radhouani, Hajer; Pardal, Miguel; Igrejas, Gilberto; Poeta, Patrícia

    2011-09-01

    Enterococci have emerged as important nosocomial and community-acquired pathogens in humans. The presence of vanA-enterococci was investigated in 103 fecal samples recovered from mullets fish (Liza ramada). All fecal samples were inoculated in Slanetz-Bartley agar plates supplemented with 4 mg/L of vancomycin for vancomycin-resistant enterococci (VRE) recovery and two isolates/sample were characterized. Antibiotic susceptibility was tested for 11 antibiotics by disk diffusion and agar dilution methods. VRE identification was performed by biochemical and molecular methods. Additionally, the mechanisms of resistance to glycopeptides (vanA, vanB, vanC1, vanC2, and vanD) and other antibiotics [erm(A), erm(B), tet(L), tet(M), aph(2'')-aac(6'), aph(3')-IIIa, ant(6'), vat(D), vat(E)] as well as the presence of enterococcal surface protein (esp) and hyl virulence factors were investigated. vanA-Enterococcus faecium isolates were recovered from 4 of 103 tested samples, and they showed glycopeptide and erythromycin resistances. Three of them were also ampicillin resistant, two showed resistance to tetracycline, ciprofloxacin, and kanamycin, and one showed resistance to gentamicin. The tet(M) and erm(B) genes were found in all tetracycline- and erythromycin-resistant strains, respectively. The aph(3')-III and aph(2'')-aac(6') genes were identified in the kanamycin- and gentamicin-resistant isolates, respectively. The IS1216 element was identified within vanX-vanY region of Tn1546 in two vanA isolates. The hyl and esp virulence genes were found in four and two isolates, respectively. vanA-strains were ascribed to sequence types ST280 (two isolates) and ST273 (two isolates), including both lineages into the clonal complex CC17. Mullets fish can excrete VRE in their feces and may be a reservoir for such resistant bacteria that can be transmitted to other animals including humans. PMID:21563953

  17. 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

  18. 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.

  19. Nuclear Astrophysics Animations from the Nuclear Astrophysics Group at Clemson University

    DOE Data Explorer

    Meyer, Bradley; The, Lih-Sin

    The nuclear astrophysics group at Clemson University in South Carolina develops on-line tools and computer programs for astronomy, nuclear physics, and nuclear astrophysics. They have also done short animations that illustrate results from research with some of their tools. The animations are organized into three sections. The r-Process Movies demonstrate r-Process network calculations from the paper "Neutrino Capture and the R-Process" Meyer, McLaughlin, and Fuller, Phys. Rev. C, 58, 3696-3710 (1998). The Alpha-Rich Freezeout Movies are related to the reference: Standard alpha-rich freezeout calculation from The, Clayton, Jin, and Meyer 1998, Astrophysical Journal, "Reaction Rates Governing the Synthesis of 44Ti" At the current writing, the category for Low Metallicity s-Process Movies has only one item called n, p, 13C, 14N, 54Fe, and 88Sr Time evolution in convective zone.

  20. Savannah River Site sample and analysis plan for Clemson Technical Center waste

    SciTech Connect

    Hagstrom, T.

    1998-04-01

    The purpose of this sampling and analysis plan is to determine the chemical, physical and radiological properties of the SRS radioactive Polychlorinated Biphenyl (PCB) liquid waste stream, to verify that it conforms to Waste Acceptance Criteria of the Department of Energy (DOE) East Tennessee Technology Park (ETTP) Toxic Substance Control Act (TSCA) Incineration Facility. Waste being sent to the ETTP TSCA Incinerator for treatment must be sufficiently characterized to ensure that the waste stream meets the waste acceptance criteria to ensure proper handling, classification, and processing of incoming waste to meet the Waste Storage and Treatment Facility`s Operating Permits. This sampling and analysis plan is limited to WSRC container(s) of homogeneous or multiphasic radioactive PCB contaminated liquids generated in association with a treatability study at Clemson Technical Center (CTC) and currently stored at the WSRC Solid Waste Division Mixed Waste Storage Facility (MWSF).

  1. First multicharged ion irradiation results from the CUEBIT facility at Clemson University

    SciTech Connect

    Shyam, R.; Kulkarni, D. D.; Field, D. A.; Srinadhu, E. S.; Harriss, J. E.; Cutshall, D. B.; Harrell, W. R.; Sosolik, C. E.

    2015-01-09

    A new electron beam ion trap (EBIT) based ion source and beamline were recently commissioned at Clemson University to produce decelerated beams of multi- to highly-charged ions for surface and materials physics research. This user facility is the first installation of a DREEBIT-designed superconducting trap and ion source (EBIS-SC) in the U.S. and includes custom-designed target preparation and irradiation setups. An overview of the source, beamline, and other facilities as well as results from first measurements on irradiated targets are discussed here. Results include extracted charge state distributions and first data on a series of irradiated metal-oxide-semiconductor (MOS) device targets. For the MOS devices, we show that voltage-dependent capacitance can serve as a record of the electronic component of ion stopping power for an irradiated, encapsulated oxide target.

  2. 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

  3. 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

  4. Assessment of biological effects of environmental pollution in Mersin Bay (Turkey, northeastern Mediterranean Sea) using Mullus barbatus and Liza ramada as target organisms.

    PubMed

    Yılmaz, Doruk; Kalay, Mustafa; Dönmez, Erdem; Yılmaz, Nejat

    2016-01-01

    The increasing emphasis on the assessment and monitoring of marine ecosystems has revealed the need to use appropriate biological indicators for these areas. Enzyme activities and histopathology are increasingly being used as indicators of environmental stress since they provide a definite biological end-point of pollutant exposure. As part of an ecotoxicological assessment of Mersin Bay, EROD enzyme activity and histopathological response in selected organs and tissues of two species of fish, Mullus barbatus (red mullet) and Liza ramada (thinlip grey mullet), captured from area were examined. Pollutant (Organochlorines (OC), alkylphenols (APs) and BPA) levels and biomarker responses in tissue samples were evaluated together for their potential to alter the metabolism and cellular aspects in liver and gonad. Elevated induction of EROD activity and histopathological alterations in contaminated samples from Mersin Bay was observed compared to reference site indicating the exposure to potential pollutants. PMID:26552534

  5. 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.

  6. 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

  7. 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

  8. Clemson University Science Master's Program in Sustainable and Resilient Infrastructure: A program evaluation

    NASA Astrophysics Data System (ADS)

    O'Sell, Elizabeth Eberhart

    The Clemson University Science Master's Program (SMP) in Sustainable and Resilient Infrastructure is a program which aims to link engineering, materials, construction, environment, architecture, business, and public policy to produce graduates with unique holistic perspective and expertise to immediately contribute to the workforce in the area of sustainable and resilient infrastructure. A program evaluation of the SMP has been performed to study the effectiveness of the SMP and identify areas where the goals and vision of the SMP are achieved and areas where improvements can be made. This was completed by analysis of trends within survey responses, review of Master's thesis reports, and review of courses taken. It was found that the SMP has facilitated new interdisciplinary research collaborations of faculty in different concentration areas within the Glenn Department of Civil Engineering, as well as collaboration with faculty in other departments. It is recommended that a course which provides instruction in all eight competency areas be required for all SMP students to provide a comprehensive overview and ensure all students are exposed to concepts of all competency areas. While all stakeholders are satisfied with the program and believe it has been successful thus far, efforts do need to be made as the program moves forward to address and improve some items that have been mentioned as needing improvement. The concerns about concentration courses, internship planning, and advising should be addressed. This evaluation provides benefits to prospective students, current SMP participants, and outside program supporters. The goal of this evaluation is to provide support that the SMP is an effective and worthwhile program for participating students, while attempting to identify any necessary program improvements and provide recommendations for achieving these improvements. This goal has been accomplished.

  9. 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

  10. 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

  11. 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, ...

  12. 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 ...

  13. 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 ...

  14. 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- ...

  15. Melter performance during surrogate vitrification campaigns at the DOE/Industrial Center for Vitrification Research at Clemson University

    SciTech Connect

    Marra, J.C.; Overcamp, T.J.

    1995-10-05

    This report summarizes the results from seven melter campaigns performed at the DOE/Industrial Center for Vitrification Research at Clemson University. A brief description of the EnVitco EV-16 Joule heated glass melter and the Stir-Melter WV-0.25 stirred melter are included for reference. The report discusses each waste stream examined, glass formulations developed and utilized, specifics relating to melter operation, and a synopsis of the results from the campaigns. A `lessons learned` section is included for each melter to emphasize repeated processing problems and identify parameters which are considered extremely important to successful melter operation

  16. Genesis and Eruptive Dynamics of the Garnet-Bearing Rhyolites from the Ramadas Volcanic Centre (Altiplano-Puna Plateau, Central Andes, Argentina).

    NASA Astrophysics Data System (ADS)

    De Astis, G.; Baez, W.; Bardelli, L.; Becchio, R.; Giordano, G.; Lucci, F.; Rossetti, F.; Viramonte, J. G.

    2015-12-01

    Ramadas volcanic centre (6.6 Ma) is a monogenetic calderic depression, now largely obliterated, almost coeval with the Late Miocene outbreak of highly explosive silicic activity in the Altiplano-Puna plateau. Ramadas erupted a rather complex suite of garnet-bearing, rhyolitic pyroclastic rocks, dominated by a >35 km3 fall deposit and preceded by the emplacement of a lag breccia containing abundant metasedimentary lithics and garnet-tourmaline leucogranites. During the waning stage of the eruption, small volume phreatomagmatic deposits formed a small tuff-ring, followed by a lava coulée emplacement. Volcanological data together with textural features of typical tube pumice evidence a volatiles-rich, plinian eruption. Petrographic and textural studies on juveniles confirm the presence of euhedral garnet as dominant phase and identify micrometric metaigneous fragments (Qtz+Bt+Kfs+Mt+Tur). BSE imaging and microprobe analyses on glasses, garnets and accessory mineral phases (zircon and monazite) provide further data to understand the genesis and eruptive conditions of these atypical rhyolites, geochemically different from those outcropping in the same region. Garnets display a homogeneous, unzoned almandine-spessartine composition (Alm72-71Sps24-23Pyr0-1Grs4-3) and are contained in a glassy rhyolitic magma with peraluminous character, HREE depleted and relative LREE enriched. It's known that primary igneous garnets are rare and can only develop under restricted conditions. Additionally, the presence of Zr and Mnz is associated with both magmatic and high-T metamorphic processes. Although more data need to be collected, our study and preliminary modelling point to the occurrence of thermal metamorphism shifting to partial melting of Fe-MnO-rich metapelitic rocks (or even re-melting of older acid volcanics), with final extraction of volatiles-rich rhyolitic melts, able to produce a plinian eruption. Here, Alm-Sps garnet could represent the peritectic product of the

  17. 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)

  18. 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.

  19. 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.

  20. 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.

  1. The origin of an unusual tuff ring of perlitic rhyolite pyroclasts: The last explosive phase of the Ramadas Volcanic Centre, Andean Puna, Salta, NW Argentina

    NASA Astrophysics Data System (ADS)

    Tait, M. A.; Cas, R. A. F.; Viramonte, J. G.

    2009-05-01

    A thick sequence of bedded pyroclastic deposits, comprised largely of crystal poor, partially flow-banded perlite fragments defines the remains of a tuff ring around the eastern margin of the Miocene Ramadas Volcanic Centre (RVC), Central Andes, NW Argentina. In numerous quarry exposures, planar bed-forms dominate, but low-angle cross-stratification, lensoidal truncations and lateral pinching and swelling of cm-dm scale bed-forms occur, consistent with pyroclastic surge as the dominant transport and depositional mechanism. Intercalated are mantling, very fine grained, well-sorted, mm-cm scale planar ash layers that represent deposition from pyroclastic fall out and are most likely the products of co-surge ash clouds. Also observed are thick m-scale, laterally continuous, poorly-sorted horizons that are interpreted as pyroclastic flow deposits. Grainsize variations within the > 70 m thick succession range from fine ash to coarse lapilli, with occasional large blocks reaching 20 cm. Clast vesicularities are typically very low. The sequence constitutes a rhyolitic tuff ring around the proximal margins of the RVC. Stratigraphic relationships indicate that the tuff ring was developed following cessation of the major plinian eruption phase of the RVC. A series of pyroclastic density currents and associated ash clouds is inferred to have resulted in the construction of the rhyolitic tuff ring, with deposition focussed on the eastern and southern margins of the central vent. The fine-grained nature of the deposits and low clast vesicularity are consistent with some degree of magma:water interaction during fragmentation. Pervasive perlitic fracturing of clasts found within the tuff deposits also indicates hydration and an extended, post-depositional hydration of the pyroclastic sequence, due to the influence of meteoric water, is likely to have occurred, with deposit permeability, clast specific surface and climate influential in facilitating additional textural

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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 ...

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Trials at Clemson University, SC of method for continuous casting of non-ferrous strips: Final report, June 28--August 6, 1987

    SciTech Connect

    Palmer, F.M.

    1987-09-16

    This project was an attempt to prove a process using a metered flow of molten metal onto two counter-rotating drums, near their apexes, which when semi-solidified and carried over to the gap between the two drums would form a thin continuous strip. Such a strip could be fortified with filaments or whiskers to manufacture metal matrix composites at lowered cost. Preliminary work with lead had demonstrated that relatively simple equipment and procedures would produce strip on one drum with an adequate surface on the side contacting the drum. It was, therefore, expected that two drum casting could be used to produce strip with an adequate surface on both sides and that the process could be adapted for aluminum using the same equipment. The original plan had been to carry out the work in the foundry facility at Pennsylvania State University during 1986. However, various delays occurred, and when the sponsoring professor, Dr. Alan B. Draper, died, it was decided to move the project to Clemson University, SC, which had aluminum melting facilities, and to carry out the work during the summer of 1987. 4 figs.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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}.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  4. 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.

  5. 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.

  6. 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.

  7. 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).

  8. 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.

  9. 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.

  10. 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/.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

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

    SciTech Connect

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

    2015-04-15

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

  17. 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.

  18. 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.

  19. 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.

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

    SciTech Connect

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

    2012-04-09

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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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}.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

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

    PubMed

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

    2016-10-01

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

  4. 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.

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  1. 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.

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

    SciTech Connect

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

    2012-07-30

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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

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

    SciTech Connect

    United States. Bonneville Power Administration.

    1985-04-01

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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Career Orientations of Female Students Enrolling in Agricultural Curricula at Clemson University.

    ERIC Educational Resources Information Center

    Pettigrew, Nancy J.; Boyd, Virlyn A.

    The study determined the occupational values of 166 female home economics freshmen and 33 female agricultural freshmen at Winthrop College by asking the question: "In picking the job you would most like to have, how important are the following things about the job?" The freshmen rated by importance seven items: (1) high salary, (2) steady…

  4. 1. Historic American Buildings Survey Frederick A. Eastman, Photographer January ...

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

    1. Historic American Buildings Survey Frederick A. Eastman, Photographer January 1938 GENERAL VIEW (RAMADA IN FOREGROUND) - Indian Wattle-and-Daub Farmhouse (with Ramada), Gila River Vicinity, Poston, La Paz County, AZ

  5. A PHYSICAL, CHEMICAL, AND BIOLOGICAL ASSESSMENT OF MONITORED NATURAL RECOVERY OF PCB-CONTAMINATED SEDIMENTS IN LAKE HARTWELL, CLEMSON, NC

    EPA Science Inventory

    Management of contaminated sediments poses significant challenges due to varied contaminants and volumes of sediments to manage. Dredging, capping, and monitored natural recovery (MNR) are the primary approaches for managing the contaminated sediment risks. Understanding how eff...

  6. PHYSICAL, CHEMICAL AND BIOLOGICAL TOOLS FOR EVALUATING, MONITORED NATURAL RECOVERY OF PCB CONTAMINATED SEDIMENTS IN LAKE HARTWELL, CLEMSON, SC

    EPA Science Inventory

    Management of contaminated sediments poses significant challenges due to varied contaminants and volumes of sediments to
    manage. Dredging, capping, and monitored natural recovery (MNR) are the primary approaches for managing the contaminated sediment risks.
    Understanding ho...

  7. TTP SR1-6-WT-31, Milestone C.3-2 Annual Report on Clemson/INEEL Melter Work

    SciTech Connect

    Bickford, D.F.

    1999-10-20

    This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements.

  8. 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 …

  9. RESEARCH NEEDS FOR AUTOMATION OF WASTEWATER TREATMENT SYSTEMS. PROCEEDINGS OF A WORKSHOP HELD AT CLEMSON, S.C. ON SEPTEMBER 23-25, 1974

    EPA Science Inventory

    This report summarizes the discussions of the workshop. The primary purpose of the workshop was to define and establish priorities for research needed to automate wastewater treatment plants. Also, addressed is the effect of automation on the design and operation of wastewater re...

  10. A MULTI-ORD LAB AND REGIONAL ASSESSMENT OF MONITORED NATURAL RECOVERY OF PCB-CONTAMINATED SEDIMENTS IN LAKE HARTWELL, CLEMSON, SC

    EPA Science Inventory

    Management of contaminated sediments poses many challenges due to varied contaminants and volumes of sediments to manage. Dredging, capping, and monitored natural recovery (MNR) are the primary approaches for managing the contaminated sediment risks. Understanding how well the ...

  11. TTP SR1-6-WT-31, Milestone C.3-2 annual report on Clemson/INEEL melter work. Revision 1

    SciTech Connect

    Bickford, D.F.

    1999-12-17

    This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements.

  12. Post-impact fatigue of cross-plied, through-the-thickness reinforced carbon/epoxy composites. M.S. Thesis - Clemson Univ.

    NASA Technical Reports Server (NTRS)

    Serdinak, Thomas E.

    1994-01-01

    An experimental investigation of the post-impact fatigue response of integrally woven carbon/epoxy composites was conducted. Five different through-the-thickness (TTT) reinforcing fibers were used in an experimental textile process that produced an integrally woven (0/90/0/90/0/90/0/90/0)(sub T) ply layup with 21K AS4 carbon tow fiber. The resin was Hercules 3501-6, and the five TTT reinforcing fibers were Kevlar, Toray carbon, AS4 carbon, glass, and IM6 carbon. The purpose of this investigation was to study the post-impact fatigue response of these material systems and to identify the optimum TTT fiber. Samples were impacted with one half inch diameter aluminum balls with an average velocity of 543 ft/sec. Post-impact static compression and constant amplitude tension-compression fatigue tests were conducted. Fatigue tests were conducted with a loading ratio of R=-5, and frequency of 4 Hz. Damage growth was monitored using x-radiographic and sectioning techniques and by examining the stress-strain response (across the impact site) throughout the fatigue tests. The static compressive stress versus far-field strain response was nearly linear for all material groups. All the samples had a transverse shear failure mode. The average compressive modulus (from far-field strain) was about 10 Msi. The average post-impact static compressive strength was about 35.5 Ksi. The IM6 carbon sample had a strength of over 40 Ksi, more than 16 percent stronger than average. There was considerable scatter in the S-N data. However, the IM6 carbon samples clearly had the best fatigue response. The response of the other materials, while worse than IM6 carbon, could not be ranked definitively. The initial damage zones caused by the impact loading and damage growth from fatigue loading were similar for all five TTT reinforcing materials. The initial damage zones were circular and consisted of delaminations, matrix cracks and ply cracks. Post-impact fatigue loading caused delamination growth, ply cracking and fiber bundle failures, typically 45 deg from impact load direction. During the initial 97 percent of fatigue life, delaminations, ply cracks and fiber bundle failures primarily grew at and near the impact site. During the final 3 percent of life, damage grew rapidly transverse to the loading direction as a through-the-thickness transverse shear failure. The stress-strain response was typically linear during the initial 50 percent of life, and stiffness dropped about 20 percent during this period. During the next 47 percent of life, stiffness dropped about 34 percent, and the stress-strain response was no longer linear. The stiffness decreased about 23 percent during the final 3 percent of life. These trends were typical of all the materials tested. Therefore, by monitoring stiffness loss, fatigue failure could be accurately anticipated.

  13. 78 FR 55071 - PacifiCorp Energy; Notice of Intent To File License Application, Filing of Pre-Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... Scoping Meeting Date and Time: Tuesday, September 24, 2013, 9:00 a.m. (PST). Location: Ramada Medford... Time: Tuesday, September 24, 2013, 7:00 p.m. (PST). Location: Ramada Medford, 2250 Biddle Road, Medford... Environmental Site Review of the project on Tuesday, September 24, 2013, starting at 1:00 p.m. (PST)....

  14. 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,…

  15. 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.

  16. 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

  17. 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,…

  18. 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…

  19. 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

  20. 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 ...

  1. 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…

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. Tested Studies for Laboratory Teaching. Proceedings of the Workshop/Conference of the Association for Biology Laboratory Education (ABLE) (5th, Clemson, South Carolina, June 13-17, 1983).

    ERIC Educational Resources Information Center

    Goldman, Corey A., Ed.; And Others

    The focus of the Association for Biology Laboratory Education (ABLE) is to improve the undergraduate biology laboratory experience by promoting the development and dissemination of interesting, innovative, and reliable laboratory exercises. This proceedings volume contains eight papers: "Bacterial Transformation" (M. J. Ernest & N. J. Rosenbaum);…

  10. Interior view, detail view in the northeast bedroom to show ...

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

    Interior view, detail view in the northeast bedroom to show window south of the fireplace, with scale; note water damage visible on wallpaper - Fort Hill, Clemson University Campus, Clemson, Pickens County, SC