Sample records for high-k pair-broken bands

  1. Direct transitions from high-K isomers to low-K bands -- {gamma} softness or coriolis coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R.; Narimatsu, Kanako; Ohtsubo, Shin-Ichi [Kyushu Univ., Fukuoka (Japan)] [and others


    Recent measurements of direct transitions from high-K isomers to low-K bands reveal severe break-down of the K-selection rule and pose the problem of how to understand the mechanism of such K-violation. The authors recent systematic calculations by using a simple {gamma}-tunneling model reproduced many of the observed hindrances, indicating the importance of the {gamma} softness. However, there are some data which cannot be explained in terms of the {gamma}-degree of freedom. In this talk, the authors also discuss the results of conventional Coriolis coupling calculations, which is considered to be another important mechanism.

  2. Compact K-band bandpass filter on high- k LiNbO 3 substrate (United States)

    Wu, Chia-Sung; Liu, Hsing-Chung; Liu, Zhi-Ping; Chiu, Hsien-Chin


    A novel miniaturized microstrip-line filter with a pair of meandering resonators on lithium niobate LiNbO 3 substrate with a high dielectric constant is proposed. A stepped-impedance structure is integrated into this new filter simultaneously to reduce dimensions and suppress the spurious responses. A substrate with a high dielectric constant is also effective in reducing the filter size because it has a high coupling efficiency. The cross-coupling effect can be achieved in this designed filter. A copper (Cu) interconnection was also used in this investigation to improve further the quality factor and the insertion loss of this filter. The filter has two transmission zeros one on each side of the passband. The experimental results in the K-band verify the design.

  3. Description of multi-quasiparticle bands by the tilted axis cranking model 21.60.-n; High K rotational bands; Tilted axis cranking; Multi-quasiparticle configurations

    CERN Document Server

    Frauendorf, S


    The selfconsistent cranking approach is extended to the case of rotation about an axis which is tilted with respect to the principal axes of the deformed potential (Tilted Axis Cranking). Expressions for the energies and the intra bands electro-magnetic transition probabilities are given. The mean field solutions are interpreted in terms of quantal rotational states. The construction of the quasiparticle configurations and the elimination of spurious states is discussed. The application of the theory to high spin data is demonstrated by analyzing the multi-quasiparticle bands in the nuclides with N=102,103 and Z=71,72,73.

  4. Band alignment of atomic layer deposited high-k Al{sub 2}O{sub 3}/multilayer MoS{sub 2} interface determined by X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinke; He, Jiazhu; Tang, Dan [College of Materials Science and Engineering, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen University, 3688 Nanhai Ave, Shenzhen, 518060 (China); Liu, Qiang; Wen, Jiao [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, 865 Chang Ning Road, Shanghai, 200050 (China); Yu, Wenjie, E-mail: [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, 865 Chang Ning Road, Shanghai, 200050 (China); Lu, Youming; Zhu, Deliang; Liu, Wenjun; Cao, Peijiang; Han, Sun [College of Materials Science and Engineering, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen University, 3688 Nanhai Ave, Shenzhen, 518060 (China); Pan, Jisheng [Institute of Materials Research and Engineering, Agency for Science Technology and Research, 117602 (Singapore); Liu, Wenjun [Department of Microelectronics, Fudan University, 220 Handan Road, Shanghai, 200433 (China); Ang, Kah Wee [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 (Singapore); He, Zhubing [Department of Materials Science and Engineering, South University of Science and Technology of China, 1088 Xueyuan Road, Shenzhen, 518055 (China)


    The energy band alignment between Al{sub 2}O{sub 3}/multilayer (ML)-MoS{sub 2} was characterized using high-resolution x-ray photoelectron spectroscopy (XPS). The Al{sub 2}O{sub 3} was deposited using an atomic layer deposition (ALD) tool. A valence band offset of 4.10 eV and a conduction band offset of 3.41 eV were obtained across the ALD-Al{sub 2}O{sub 3}/ML-MoS{sub 2} interface. For comparison, the valence band offset and a conduction band offset were also obtained for ALD-SiO{sub 2}/ML-MoS{sub 2} interface. It was found out that ALD-Al{sub 2}O{sub 3}/ML-MoS{sub 2} interface has a larger conduction band offset, compared to that of ALD-SiO{sub 2}/ML-MoS{sub 2} interface, which indicate ALD-Al{sub 2}O{sub 3} served as the gate dielectric for n-type ML-MoS{sub 2} based field effect transistors has advantage over ALD-SiO{sub 2} in term of suppressing the gate leakage current. - Highlights: • The band alignment of ALD-Al{sub 2}O{sub 3}/ML-MoS{sub 2} was characterized using XPS. • The ΔE{sub V} and ΔE{sub C} of ALD-Al{sub 2}O{sub 3}/ML-MoS{sub 2} is found to be 4.10 eV and 3.41 eV, respectively. • ALD-Al{sub 2}O{sub 3} served as the gate dielectric for n-type ML-MoS{sub 2} based FETs has advantage of ALD-SiO{sub 2}.

  5. Tunneling in high-K isomeric decays

    CERN Document Server

    Shizuma, T; Shimizu, Y R


    We have systematically investigated highly-K-forbidden transitions observed in the Hf, W and Os region, using the gamma-tunneling model in which low-K and high-k states interact through a process of quantum tunneling. The measured hindrance factors are compared with the values calculated using the gamma-tunneling model. Isotope dependences of gamma-tunneling probabilities particularly for neutron-rich nuclei and the relation to stimulated decays of isomers are discussed. (author)

  6. Volatiles in High-K Lunar Basalts (United States)

    Barnes, Jessica J.; McCubbin, Francis M.; Messenger, Scott R.; Nguyen, Ann; Boyce, Jeremy


    Chlorine is an unusual isotopic system, being essentially unfractionated ((delta)Cl-37 approximately 0 per mille ) between bulk terrestrial samples and chondritic meteorites and yet showing large variations in lunar (approximately -4 to +81 per mille), martian, and vestan (HED) samples. Among lunar samples, the volatile-bearing mineral apatite (Ca5(PO4)3[F,Cl,OH]) has been studied for volatiles in K-, REE-, and P (KREEP), very high potassium (VHK), low-Ti and high-Ti basalts, as well as samples from the lunar highlands. These studies revealed a positive correlation between in-situ (delta)Cl-37 measurements and bulk incompatible trace elements (ITEs) and ratios. Such trends were interpreted to originate from Cl isotopic fractionation during the degassing of metal chlorides during or shortly after the differentiation of the Moon via a magma ocean. In this study, we investigate the volatile inventories of a group of samples for which new-era volatile data have yet to be reported - the high-K (greater than 2000 ppm bulk K2O), high-Ti, trace element-rich mare basalts. We used isotope imaging on the Cameca NanoSIMS 50L at JSC to obtain the Cl isotopic composition [((Cl-37/(35)Clsample/C-37l/(35)Clstandard)-1)×1000, to get a value in per thousand (per mille)] which ranges from approximately -2.7 +/- 2 per mille to +16.1 +/- 2 per mille (2sigma), as well as volatile abundances (F & Cl) of apatite in samples 10017, 10024 & 10049. Simply following prior models, as lunar rocks with high bulk-rock abundances of ITEs we might expect the high-K, high-Ti basalts to contain apatite characterized by heavily fractionated (delta)Cl-37 values, i.e., Cl obtained from mixing between unfractionated mantle Cl (approximately 0 per mille) and the urKREEP reservoir (possibly fractionated to greater than +25 per mille.). However, the data obtained for the studied samples do not conform to either the early degassing or mixing models. Existing petrogentic models for the origin of the high-K

  7. Projected shell model analysis of multi-quasiparticle high-K isomers in sup 1 sup 7 sup 4 Hf

    CERN Document Server

    Zhou Xian Rong; Sun Yang; Long Gui Lu


    Multi-quasiparticle high-K states in sup 1 sup 7 sup 4 Hf are studied in the framework of the projected shell model. The calculation reproduces well the observed ground-state band as well as most of the two- and four-quasiparticle rotational bands. Some as yet unobserved high-K isomeric states in sup 1 sup 7 sup 4 Hf are predicted. Possible reasons for the existing discrepancies between calculation and experiment are discussed. It is suggested that the projected shell model may be a useful method for studying multi-quasiparticle high-K isomers and the K-mixing phenomenon in heavy deformed nuclei

  8. High-K Strategy Scale: A Measure of the High-K Independent Criterion of Fitness

    Directory of Open Access Journals (Sweden)

    Cezar Giosan


    Full Text Available The present study aimed at testing whether factors documented in the literature as being indicators of a high-K reproductive strategy have effects on fitness in extant humans. A 26-item High-K Strategy Scale comprising these factors was developed and tested on 250 respondents. Items tapping into health and attractiveness, upward mobility, social capital and risks consideration, were included in the scale. As expected, the scale showed a significant correlation with perceived offspring quality and a weak, but significant association with actual number of children. The scale had a high reliability coefficient (Cronbach's Alpha = .92. Expected correlations were found between the scale and number of medical diagnoses, education, perceived social support, and number of previous marriages, strengthening the scale's construct validity. Implications of the results are discussed.

  9. Engineering the Propagation of High-k Bulk Plasmonic Waves in Multilayer Hyperbolic Metamaterials by Multiscale Structuring

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Lavrinenko, Andrei; Sipe, John E.

    layers. These high-k waves can have anomalously short wavelength, which underlies the concept of far-field subwavelength imaging (hyperlensing) in HMMs. In this work, we show that propagation of these high-k bulk plasmons can be controlled by modulating, or superstructuring, the filling fraction of metal...... in a subwavelength metal-dielectric stack on a longer, wavelength scale. The basic superstructure geometry is a hybrid multiscale HMM where the modulation itself is periodic, forming a photonic band gap (PBG) for the high-k waves according to the same principles as in conventional photonic crystals. As a result...

  10. Investigation of capacitance characteristics in metal/high-k ...

    Indian Academy of Sciences (India)

    Keywords. C − V characteristic; high-k dielectric; interface state density; MIS structure; nanotechnology; TCAD simulation. Abstract. Capacitance vs. voltage ( C − V ) curves at AC high frequency of a metal–insulator–semiconductor (MIS) capacitorare investigated in this paper. Bi-dimensional simulations with Silvaco TCAD ...

  11. Interface Study on Amorphous Indium Gallium Zinc Oxide Thin Film Transistors Using High-k Gate Dielectric Materials

    Directory of Open Access Journals (Sweden)

    Yu-Hsien Lin


    Full Text Available We investigated amorphous indium gallium zinc oxide (a-IGZO thin film transistors (TFTs using different high-k gate dielectric materials such as silicon nitride (Si3N4 and aluminum oxide (Al2O3 at low temperature process (<300°C and compared them with low temperature silicon dioxide (SiO2. The IGZO device with high-k gate dielectric material will expect to get high gate capacitance density to induce large amount of channel carrier and generate the higher drive current. In addition, for the integrating process of integrating IGZO device, postannealing treatment is an essential process for completing the process. The chemical reaction of the high-k/IGZO interface due to heat formation in high-k/IGZO materials results in reliability issue. We also used the voltage stress for testing the reliability for the device with different high-k gate dielectric materials and explained the interface effect by charge band diagram.

  12. Alternative high-k dielectrics for semiconductor applications


    Van Elshocht, S.; Adelmann, C.; Clima, S.; Pourtois, G.; Conard, T.; Delabie, A.; Franquet, A.; Lehnen, P.; Meersschaut, J.; Menou, N.; Popovici, M.; Richard, O.; Schram, T.; Wang, X. P.; HARDY, An


    Although the next generation high-k gate dielectrics has been defined for the 45 nm complementary metal oxide semiconductor technology node, threshold voltage control and equivalent oxide thickness (EOT) scaling remain concerns for future devices. Therefore, the authors explored the effect of incorporating dysprosium in the gate stack. Results suggest that improved EOT-leakage scaling is possible by adding Dy to the interfacial SiO2 layer in a 1:1 ratio or by adding 10% Dy to bulk HfO2. The d...

  13. Mechanical Design of the NSTX High-k Scattering Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Feder, R.; Mazzucato, E.; Munsat, T.; Park, H,; Smith, D. R.; Ellis, R.; Labik, G.; Priniski, C.


    The NSTX High-k Scattering Diagnostic measures small-scale density fluctuations by the heterodyne detection of waves scattered from a millimeter wave probe beam at 280 GHz and {lambda}=1.07 mm. To enable this measurement, major alterations were made to the NSTX vacuum vessel and Neutral Beam armor. Close collaboration between the PPPL physics and engineering staff resulted in a flexible system with steerable launch and detection optics that can position the scattering volume either near the magnetic axis ({rho} {approx} .1) or near the edge ({rho} {approx} .8). 150 feet of carefully aligned corrugated waveguide was installed for injection of the probe beam and collection of the scattered signal in to the detection electronics.

  14. Modeling of leakage currents in high-k dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Jegert, Gunther Christian


    Leakage currents are one of the major bottlenecks impeding the downscaling efforts of the semiconductor industry. Two core devices of integrated circuits, the transistor and, especially, the DRAM storage capacitor, suffer from the increasing loss currents. In this perspective a fundamental understanding of the physical origin of these leakage currents is highly desirable. However, the complexity of the involved transport phenomena so far has prevented the development of microscopic models. Instead, the analysis of transport through the ultra-thin layers of high-permittivity (high-k) dielectrics, which are employed as insulating layers, was carried out at an empirical level using simple compact models. Unfortunately, these offer only limited insight into the physics involved on the microscale. In this context the present work was initialized in order to establish a framework of microscopic physical models that allow a fundamental description of the transport processes relevant in high-k thin films. A simulation tool that makes use of kinetic Monte Carlo techniques was developed for this purpose embedding the above models in an environment that allows qualitative and quantitative analyses of the electronic transport in such films. Existing continuum approaches, which tend to conceal the important physics behind phenomenological fitting parameters, were replaced by three-dimensional transport simulations at the level of single charge carriers. Spatially localized phenomena, such as percolation of charge carriers across pointlike defects, being subject to structural relaxation processes, or electrode roughness effects, could be investigated in this simulation scheme. Stepwise a self-consistent, closed transport model for the TiN/ZrO{sub 2} material system, which is of outmost importance for the semiconductor industry, was developed. Based on this model viable strategies for the optimization of TiN/ZrO{sub 2}/TiN capacitor structures were suggested and problem areas

  15. Structural and optical properties of germanium nanostructures on Si(100 and embedded in high-k oxides

    Directory of Open Access Journals (Sweden)

    Ray Samit


    Full Text Available Abstract The structural and optical properties of Ge quantum dots (QDs grown on Si(001 for mid-infrared photodetector and Ge nanocrystals embedded in oxide matrices for floating gate memory devices are presented. The infrared photoluminescence (PL signal from Ge islands has been studied at a low temperature. The temperature- and bias-dependent photocurrent spectra of a capped Si/SiGe/Si(001 QDs infrared photodetector device are presented. The properties of Ge nanocrystals of different size and density embedded in high-k matrices grown using radio frequency magnetron sputtering have been studied. Transmission electron micrographs have revealed the formation of isolated spherical Ge nanocrystals in high-k oxide matrix of sizes ranging from 4 to 18 nm. Embedded nanocrystals in high band gap oxides have been found to act as discrete trapping sites for exchanging charge carriers with the conduction channel by direct tunneling that is desired for applications in floating gate memory devices.

  16. Investigation of 6T SRAM memory circuit using high-k dielectrics based nano scale junctionless transistor (United States)

    Charles Pravin, J.; Nirmal, D.; Prajoon, P.; Mohan Kumar, N.; Ajayan, J.


    In this paper the Dual Metal Surround Gate Junctionless Transistor (DMSGJLT) has been implemented with various high-k dielectric. The leakage current in the device is analysed in detail by obtaining the band structure for different high-k dielectric material. It is noticed that with increasing dielectric constant the device provides more resistance for the direct tunnelling of electron in off state. The gate oxide capacitance also shows 0.1 μF improvement with Hafnium Oxide (HfO2) than Silicon Oxide (SiO2). This paved the way for a better memory application when high-k dielectric is used. The Six Transistor (6T) Static Random Access Memory (SRAM) circuit implemented shows 41.4% improvement in read noise margin for HfO2 than SiO2. It also shows 37.49% improvement in write noise margin and 30.16% improvement in hold noise margin for HfO2 than SiO2.

  17. Physical origin investigation of the flatband voltage roll off for metal-oxide-semiconductor device with high-k/metal gate structure (United States)

    Kai, Han; Xiaolei, Wang; Wenwu, Wang


    The physical origin of the flatband voltage (VFB) roll off for a metal-oxide-semiconductor device with high-k/metal gate structure is studied from the viewpoint of energy band alignment at the high-k/Si interface because the thickness of SiO2 interlayer is thin enough to be ignored. The VFB roll off phenomenon is assigned to associate with the direct electron transfer between high-k and Si substrate. Quantitatively calculated simulation results based on this model are given considering different conditions. Project supported by the National Natural Science Foundation of China (Nos. 61404093, 50932001) and the Doctoral Scientific Research Foundation of Weifang University (No. 014BS02).

  18. Extraction and dielectric properties of curcuminoid films grown on Si substrate for high-k dielectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Dakhel, A.A.; Jasim, Khalil E. [Department of Physics, College of Science, University of Bahrain, P.O. Box 32038 (Bahrain); Cassidy, S. [Department of Basic Medical Sciences, Royal College of Surgeons in Ireland, Medical University of Bahrain, P.O. Box 15503 (Bahrain); Henari, F.Z., E-mail: [Department of Basic Medical Sciences, Royal College of Surgeons in Ireland, Medical University of Bahrain, P.O. Box 15503 (Bahrain)


    Highlights: • The unknown insulating properties of curcuminoid extract are systematically studied. • Optical study gives a bandgap of 3.15 eV and a refractive index of 1.92 at 505 nm. • Turmeric is a high-k environmental friendly material for use in microelectronics. • Curcuminoid extract can be used as insulator of MIS devices with ε{sup ′}{sub ∞}≈54.2. -- Abstract: Curcuminoids were extracted from turmeric powder and evaporated in vacuum to prepare thin films on p-Si and glass substrates for dielectric and optical investigations. The optical absorption spectrum of the prepared amorphous film was not identical to that of the molecular one, which was identified by a strong wide absorption band in between ∼220 and 540 nm. The onset energy of the optical absorption of the film was calculated by using Hamberg et al. method. The dielectric properties of this material were systematically studied for future eco friendly applications in metal–insulator–semiconductor MIS field of applications. The complex dielectric properties were studied in the frequency range of 1–1000 kHz and was analysed in-terms of dielectric impedance Z{sup *}(ω) and modulus M{sup *}(ω). Generally, the curcuminoid complex can be considered as a high-k material and can be used in the environmental friendly production of microelectronic devices.

  19. Engineering the propagation of high-k bulk plasmonic waves in multilayer hyperbolic metamaterials by multiscale structuring

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Lavrinenko, Andrei; Sipe, J. E.


    Propagation of large-wavevector bulk plasmonic waves in multilayer hyperbolic metamaterials (HMMs) with two levels of structuring is theoretically studied. It is shown that when the parameters of a subwavelength metal-dielectric multilayer (substructure) are modulated (superstructured) on a larger......, wavelength scale, the propagation of bulk plasmon polaritons in the resulting multiscale HMM is subject to photonic band gap phenomena. A great degree of control over such plasmons can be exerted by varying the superstructure geometry. As an example, Bragg reflection and Fabry-Pérot resonances...... to be a promising platform for using high-k bulk plasmonic waves as a new kind of information carriers, which can be used in far-field subwavelength imaging and plasmonic communication....

  20. High performance trench MOS barrier Schottky diode with high-k gate oxide (United States)

    Zhai, Dong-Yuan; Zhu, Jun; Zhao, Yi; Cai, Yin-Fei; Shi, Yi; Zheng, You-Liao


    A novel trench MOS barrier Schottky diode (TMBS) device with a high-k material introduced into the gate insulator is reported, which is named high-k TMBS. By simulation with Medici, it is found that the high-k TMBS can have 19.8% lower leakage current while maintaining the same breakdown voltage and forward turn-on voltage compared with the conventional regular trench TMBS. Project supported by the National Basic Research Program of China (Grant No. 2011CBA00607), the National Natural Science Foundation of China (Grant Nos. 61106089 and 61376097), and the Zhejiang Provincial Natural Science Foundation of China (Grant No. LR14F040001).

  1. Is a Successful High-K Fitness Strategy Associated with Better Mental Health?

    Directory of Open Access Journals (Sweden)

    Cezar Giosan


    Full Text Available This study examined the associations between a high-K fitness strategy and mental health. These associations were tested on a sample of 1400 disaster workers who had exposure to a singular traumatic event and who underwent psychological evaluations. The results showed that high-K was an important negative predictor of psychopathology, accounting for significant variance in PTSD, general psychopathology, functional disability, anger, and sleep disturbances. Implications of the results are discussed.

  2. High-K isomers as probes of octupole collectivity in heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Walker, P.M., E-mail: [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Minkov, N. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784 Sofia (Bulgaria)


    The influence of the octupole deformation on the structure of high-K isomeric states in the region of heavy even-even actinide nuclei is studied through a reflection asymmetric deformed shell model (DSM). Two-quasiparticle states with high-K values are constructed by taking into account the pairing effect through a DSM + BCS procedure with constant pairing interaction. The behaviour of two-quasiparticle energies and magnetic dipole moments of K{sup {pi}=}6{sup +}, 6{sup -} and 8{sup -} configurations, applicable to mass numbers in the range A=234-252, was examined over a wide range of quadrupole and octupole deformations. A pronounced sensitivity of the magnetic moments to the octupole deformation is found. The result suggests a possibly important role for high-K isomers in determining the degree of octupole deformation in heavy actinide nuclei.

  3. Bilayer Polymer Metacomposites Containing Negative Permittivity Layer for New High-k Materials. (United States)

    Wang, Jing; Shi, Zhicheng; Mao, Fan; Chen, Shougang; Wang, Xin


    Polymer matrix high-k composites are of considerable interest in various electronic devices, such as capacitors, antennas, actuators, etc. However, how to enhance the permittivity without elevating the loss remains a challenge for us. Here we present a novel design of bilayer high-k metacomposites consisting of two stacked single layers with positive permittivity and negative permittivity. Interestingly, the bilayer system shows an obvious permittivity boost effect with a permittivity improved by a 40-fold increase compared with the polymer matrix, while maintaining a loss tangent as low as 0.06. Further calculation results indicate that the permittivity of the bilayer composites could be enhanced by 4000-fold or even a greater increase as compared with the polymer matrix via balancing the dielectric properties of single layers. Insights into how the thickness ratios and dielectric properties of single layers interfere with the dielectric performances of bilayer composites were discussed. This study provides a new route for the design of high-k materials, and it will have great significance on the development of dielectric materials. Hopefully, multilayer high-k metacomposites with fascinating dielectric performances could be achieved via balancing the dielectric properties of single layers.

  4. Comprehensive capacitance-voltage analysis including quantum effects for high-k interfaces on germanium and other alternative channel materials (United States)

    Anwar, Sarkar R. M.

    High mobility alternative channel materials to silicon are critical to the continued scaling of metal oxide semiconductor (MOS) devices. However, before they can be incorporated into advanced devices, some major issues need to be solved. The high mobility materials suffer from lower allowable thermal budgets compared to Si (before desorption and defect formation becomes an issue) and the absence of a good quality native oxide has further increased the interest in the use of high-k dielectrics. However, the high interface state density and high electric fields at these semiconductor/high-k interfaces can significantly impact the capacitance-voltage (C-V) profile, and current C-V modeling software cannot account for these effects. This in turn affects the parameters extracted from the C-V data of the high mobility semiconductor/high-k interface, which are crucial to fully understand the interface properties and expedite process development. To address this issue, we developed a model which takes into account quantum corrections which can be applied to a number of these alternative channel materials including SixGe1-x, Ge, InGaAs, and GaAs. The C-V simulation using this QM correction model is orders of magnitude faster compared to a full band Schrodinger-Poisson solver. The simulated C-V is directly benchmarked to a self consistent Schrodinger-Poisson solution for each bulk semiconductor material, and from the benchmarking process the QM correction parameters are extracted. The full program, C-V Alternative Channel Extraction (CV ACE), incorporates a quantum mechanical correction model, along with the interface state density model, and can extract device parameters such as equivalent oxide thickness (EOT), doping density and flat band voltage (Vfb) as well as the interface state density profile using multiple measurements performed at different frequencies and temperatures, simultaneously. The program was used to analyze experimentally measured C-V profiles and the

  5. Capacitance–voltage analysis of electrical properties for WSe2 field effect transistors with high-k encapsulation layer (United States)

    Ko, Seung-Pil; Shin, Jong Mok; Jang, Ho Kyun; You, Min Youl; Jin, Jun-Eon; Choi, Miri; Cho, Jiung; Kim, Gyu-Tae


    Doping effects in devices based on two-dimensional (2D) materials have been widely studied. However, detailed analysis and the mechanism of the doping effect caused by encapsulation layers has not been sufficiently explored. In this work, we present experimental studies on the n-doping effect in WSe2 field effect transistors (FETs) with a high-k encapsulation layer (Al2O3) grown by atomic layer deposition. In addition, we demonstrate the mechanism and origin of the doping effect. After encapsulation of the Al2O3 layer, the threshold voltage of the WSe2 FET negatively shifted with the increase of the on-current. The capacitance–voltage measurements of the metal insulator semiconductor (MIS) structure proved the presence of the positive fixed charges within the Al2O3 layer. The flat-band voltage of the MIS structure of Au/Al2O3/SiO2/Si was shifted toward the negative direction on account of the positive fixed charges in the Al2O3 layer. Our results clearly revealed that the fixed charges in the Al2O3 encapsulation layer modulated the Fermi energy level via the field effect. Moreover, these results possibly provide fundamental ideas and guidelines to design 2D materials FETs with high-performance and reliability.

  6. High-K isomers in transactinide nuclei close to N = 162

    Energy Technology Data Exchange (ETDEWEB)

    Prassa, V., E-mail:; Nikšić, T.; Vretenar, D. [Physics Department, Faculty of science, University of Zagreb, 10000 Zagreb (Croatia); Lu, Bing-Nan [Institut fur Kernphysik, Institute for Advanced Simulation, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Ackermann, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany)


    Transactinide nuclei around neutron number N = 162 display axially deformed equilibrium shapes, as shown in our previous analysis [1] of constrained mean-field energy surfaces and collective excitation spectra. In the present study we are particularly interested in the occurrence of high-K isomers in the axially deformed isotopes of Rf (Z = 104), Sg (Z = 106), Hs (Z = 108), and Ds (Z = 110), with neutron number N = 160 − 166 and the effect of the N=162 closure on the structure and distribution of two-quasiparticle (2qp) states. The evolution of high-K isomers is analysed in a self-consistent axially-symmetric relativistic Hartree-Bogoliubov calculation using the blocking approximation with time-reversal symmetry breaking.

  7. High-k Dielectric Passivation for GaN Diode with a Field Plate Termination

    Directory of Open Access Journals (Sweden)

    Michitaka Yoshino


    Full Text Available Vertical structured Gallium nitride (GaN p-n junction diodes with improved breakdown properties have been demonstrated using high-k dielectric passivation underneath the field plate. Simulation results at a reverse voltage of 1 kV showed that the maximum electric field near the mesa-etched p-n junction edges covered with film of dielectric constant k = 10 was reduced to 2.0 MV/cm from 3.0 MV/cm (SiO2 (k = 3.9. The diodes were fabricated using the high-k mixed oxide of SiO2 and CeO2 with k = 12.3. I–V characteristics of the diode with a field plate showed a breakdown voltage above 2 kV with an increased avalanche resistance. This means that the electric field reduces at the periphery of the mesa-etched p-n junction and is uniformly formed across the whole p-n junction. It is clear that high-k dielectric film passivation and filed plate termination are essential techniques for GaN power devices.

  8. High-k dielectrics as bioelectronic interface for field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Borstlap, D.


    Ion-sensitive field-effect transistors (ISFETs) are employed as bioelectronic sensors for the cell-transistor coupling and for the detection of DNA sequences. For these applications, thermally grown SiO{sub 2} films are used as standard gate dielectric. In the first part of this dissertation, the suitability of high-k dielectrics was studied to increase the gate capacitance and hence the signal-to-noise ratio of bioelectronic ISFETs: Upon culturing primary rat neurons on the corresponding high-k dielectrics, Al{sub 2}O{sub 3}, yttria stabilised zirkonia (YSZ), DyScO{sub 3}, CeO{sub 2}, LaAlO{sub 3}, GdScO{sub 3} and LaScO{sub 3} proved to be biocompatible substrates. Comprehensive electrical and electrochemical current-voltage measurements and capacitance-voltage measurements were performed for the determination of the dielectric properties of the high-k dielectrics. In the second part of the dissertation, standard SiO{sub 2} ISFETs with lower input capacitance and high-k dielectric Al{sub 2}O{sub 3}, YSZ und DyScO{sub 3} ISFETs were comprehensively characterised and compared with each other regarding their signal-to-noise ratio, their ion sensitivity and their drift behaviour. The ion sensitivity measurements showed that the YSZ ISFETs were considerably more sensitive to K{sup +} and Na{sup +} ions than the SiO{sub 2}, Al{sub 2}O{sub 3} und DyScO{sub 3} ISFETs. In the final third part of the dissertation, bioelectronic experiments were performed with the high-k ISFETs. The shape of the signals, which were measured from HL-1 cells with YSZ ISFETs, differed considerably from the corresponding measurements with SiO{sub 2} and DyScO{sub 3} ISFETs: After the onset of the K{sup +} current, the action potentials measured with YSZ ISFETs showed a strong drift in the direction opposite to the K{sup +} current signal. First coupling experiments between HEK 293 cells, which were transfected with a K{sup +} ion channel, and YSZ ISFETs affirmed the assumption from the HL-1

  9. Simulation of Double-Gate Silicon Tunnel FETs with a High-k Gate Dielectric


    Boucart, Katherine


    The down-scaling of conventional MOSFETs has led to an impending power crisis, in which static power consumption is becoming too high. In order to improve the energy-efficiency of electronic circuits, small swing switches are interesting candidates to replace or complement the MOSFETs used today. Tunnel FETs, which are gated p-i-n diodes whose on-current arises from band-to-band tunneling, are attractive new devices for low-power applications due to t...

  10. Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

    KAUST Repository

    Rojas, Jhonathan Prieto


    Can we build a flexible and transparent truly high performance computer? High-k/metal gate stack based metal-oxide-semiconductor capacitor devices are monolithically fabricated on industry\\'s most widely used low-cost bulk single-crystalline silicon (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree of freedom to fabricate nanoelectronics devices using state-of-the-art CMOS compatible processes and then to utilize them in an unprecedented way for wide deployment over nearly any kind of shape and architecture surfaces. Electrical characterization shows uncompromising performance of post release devices. Mechanical characterization shows extra-ordinary flexibility (minimum bending radius of 1 cm) making this generic process attractive to extend the horizon of flexible electronics for truly high performance computers. Schematic and photograph of flexible high-k/metal gate MOSCAPs showing high flexibility and C-V plot showing uncompromised performance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Characterization of High-k Nanolayers by Grazing Incidence X-ray Spectrometry

    Directory of Open Access Journals (Sweden)

    Matthias Müller


    Full Text Available The accurate characterization of nanolayered systems is an essential topic for today’s developments in many fields of material research. Thin high-k layers and gate stacks are technologically required for the design of current and future electronic devices and can be deposited, e.g., by Atomic Layer Deposition (ALD. However, the metrological challenges to characterize such systems demand further development of analytical techniques. Reference-free Grazing Incidence X-ray Fluorescence (GIXRF based on synchrotron radiation can significantly contribute to the characterization of such nanolayered systems. GIXRF takes advantage of the incident angle dependence of XRF, in particular below the substrate’s critical angle where changes in the X-ray Standing Wave field (XSW intensity influence the angular intensity profile. The reliable modeling of the XSW in conjunction with the radiometrically calibrated instrumentation at the PTB allows for reference-free, fundamental parameter-based quantitative analysis. This approach is very well suited for the characterization of nanoscaled materials, especially when no reference samples with sufficient quality are available. The capabilities of this method are demonstrated by means of two systems for transistor gate stacks, i.e., Al2O3 high-k layers grown on Si or Si/SiO2 and Sc2O3 layers on InGaAs/InP substrates.

  12. Analysis of high-k spacer on symmetric underlap DG-MOSFET with Gate Stack architecture (United States)

    Das, Rahul; Chakraborty, Shramana; Dasgupta, Arpan; Dutta, Arka; Kundu, Atanu; Sarkar, Chandan K.


    This paper shows the systematic study of underlap double gate (U-DG) NMOSFETs with Gate Stack (GS) under the influence of high-k spacers. In highly scaled devices, underlap is used at the Source and Drain side so as to reduce the short channel effects (SCE's), however, it significantly reduces the on current due to the increased channel resistance. To overcome these drawbacks, the use of high-k spacers is projected as one of the remedies. In this paper, the analog performance of the devices is studied on the basis of parameters like transconductance (gm), transconductance generation factor (gm/Id) and intrinsic gain (gmro). The RF performance is analyzed on the merits of intrinsic capacitance (Cgd, Cgs), resistance (Rgd, Rgs), transport delay (τm), inductance (Lsd), cutoff frequency (fT), and the maximum frequency of oscillation (fmax). The circuit performance of the devices are studied by implementing the device as the driver MOSFET in a Single Stage Common Source Amplifier. The Gain Bandwidth Product (GBW) has been analyzed from the frequency response of the circuit.

  13. Structural and electrical characteristics of high-k/metal gate metal oxide semiconductor capacitors fabricated on flexible, semi-transparent silicon (100) fabric

    KAUST Repository

    Rojas, Jhonathan Prieto


    In pursuit of flexible computers with high performance devices, we demonstrate a generic process to fabricate 10 000 metal-oxide-semiconductor capacitors (MOSCAPs) with semiconductor industry\\'s most advanced high-k/metal gate stacks on widely used, inexpensive bulk silicon (100) wafers and then using a combination of iso-/anisotropic etching to release the top portion of the silicon with the already fabricated devices as a mechanically flexible (bending curvature of 133 m−1), optically semi-transparent silicon fabric (1.5 cm × 3 cm × 25 μm). The electrical characteristics show 3.7 nm effective oxide thickness, −0.2 V flat band voltage, and no hysteresis from the fabricated MOSCAPs.

  14. Multi-parameter sensing using high-k oxide of barium strontium titanate

    Energy Technology Data Exchange (ETDEWEB)

    Huck, Christina; Poghossian, Arshak; Baecker, Matthias; Schoening, Michael J. [Institute of Nano- and Biotechnologies (INB), FH Aachen, 52428, Juelich (Germany); Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich GmbH, 52525, Juelich (Germany); Reisert, Steffen; Kramer, Friederike [Institute of Nano- and Biotechnologies (INB), FH Aachen, 52428, Juelich (Germany); Begoyan, Vardges K.; Buniatyan, Vahe V. [Department of Microelectronics and Biomedical Devices, State Engineering University of Armenia, 0009, Yerevan (Armenia)


    High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors. In this work, a Si-based sensor chip containing Pt interdigitated electrodes covered with a thin BST layer (485 nm) has been developed for multi-parameter chemical sensing. The chip has been applied for the contactless measurement of the electrolyte conductivity, the detection of adsorbed charged macromolecules (positively charged polyelectrolytes of polyethylenimine) and the concentration of hydrogen peroxide (H{sub 2}O{sub 2}) vapor. The experimental results of functional testing of individual sensors are presented. The mechanism of the BST sensitivity to charged polyelectrolytes and H{sub 2}O{sub 2} vapor has been proposed and discussed. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Characterization of high-k dielectrics using MeV elastic scattering of He ions

    Energy Technology Data Exchange (ETDEWEB)

    Zoller, C.J. [Dept. of Physics and Astronomy, Ion Physics, Uppsala University, P.O. Box 516, SE 751 20 Uppsala (Sweden); Dentoni Litta, E. [KTH Royal Institute of Technology, School of ICT, Isafjordsgatan 22, SE 164 40 Kista (Sweden); Primetzhofer, D., E-mail: [Dept. of Physics and Astronomy, Ion Physics, Uppsala University, P.O. Box 516, SE 751 20 Uppsala (Sweden)


    We present a systematic comparison of two distinct ion-beam based methods for composition analysis of nanometer oxide films: ion-beam channeling and elastic scattering using nuclear resonances, both at MeV energies. Thin films of the technologically highly relevant high-k dielectrics HfO{sub 2} and HfAlO are characterized in the present study, with the additional aim of obtaining a better quantification of the Al content for the latter system. We show that both employed ion scattering methods enable a quantitative determination of the oxygen concentrations with typical uncertainties of about 5–10% in the oxygen fraction. The influence of various kinds of systematic inaccuracies in the evaluation procedure are discussed.

  16. Evaluation of Synthesis & Processing Routes for the High K- Boron Nitride Nano Tubes (BNNTS) for Thermal Management Applications Project (United States)

    National Aeronautics and Space Administration — The purpose of this proposal is to develop and demonstrate the feasibility of processing the High Thermal Conductivity Boron Nitride Nano Tubes (High-K BNNTs) that...

  17. Electronic structure of layered ferroelectric high-k titanate La2Ti2O7

    DEFF Research Database (Denmark)

    Atuchin, V. V.; Gavrilova, T. A.; Grivel, Jean-Claude


    The electronic structure of binary titanate La2Ti2O7 has been studied by x-ray photoelectron spectroscopy. Spectral features of valence band and all constituent element core levels have been considered. The Auger parameters of titanium and oxygen in La2Ti2O7 are determined as alpha(Ti) = 872...

  18. The Meaning of High K2O Volcanism In the U.S. Cordillera (United States)

    Putirka, K. D.; Busby, C.


    K2O contents provide a highly effective discriminant between volcanic rocks erupted in the Cascades and Basin-and Range-provinces, with Cascades volcanics having lower K2O contents at a given SiO2. To differentiate these suites, we use a K-index, where K-index = K2Oobserved - 0.12[SiO2] + 5.1 (oxides in wt. %). In the Sierra Nevada, regional K2O contents are not controlled by wall-rock assimilation. In addition, none are candidates for K-metasomatism, and none are likely to be derived by partial melting of a K-metasomatized source. As to the latter issue, even volcanic rocks with the highest K2O in the Sierra Nevada have K2O/Na2O 5, and as high as 30-40 (Brooks and Snee (1996). Also, Sierra-wide K2O variations are not connected to indices of subduction-related mantle enrichments (such as La/Nb, Ba/Nb or Sr/P2O5), and so K2O is unconnected to regional variations in source composition. K2O contents are instead controlled by the degree of partial melting (F) in the mantle source and fractional crystallization. Putirka and Busby (2007) show that maximum K2O in the Sierra increases with increasing crust thickness, and this relationship also holds across the U.S. the Cordillera (at 39oN latitude). This relationship implies that low F magmas more easily transit thick, low-density upper crust (Putirka and Busby, 2007), which is a consequence of the fact that low F melts are enriched not just in K2O, but also in H2O, which greatly lowers magma density (Ochs and Lange, 1999). This model can explain the contrast in Cascade and Basin-and-Range K2O contents: the modern Cascades are built on the thinner crust of accreted terranes, while typical Basin-and-Range volcanics are erupted on older, and thicker, cratonized crust. Mean crust density, however, cannot be the only explanation of high K2O. In the central Sierra Nevada, the Colorado River Extensional Corridor, and at the Lunar Crater/Nevada Test site area of NV, eruptions of high K2O magmas (K-index>1.65) coincide in time and

  19. Gradient and vorticity banding

    NARCIS (Netherlands)

    Dhont, Jan K.G.; Briels, Willem J.


    "Banded structures" of macroscopic dimensions can be induced by simple shear flow in many different types of soft matter systems. Depending on whether these bands extend along the gradient or vorticity direction, the banding transition is referred to as "gradient banding" or "vorticity banding,"

  20. Full Polymer Dielectric Elastomeric Actuators (DEA Functionalised with Carbon Nanotubes and High-K Ceramics

    Directory of Open Access Journals (Sweden)

    Tilo Köckritz


    Full Text Available Dielectric elastomer actuators (DEA are special devices which have a simple working and construction principle and outstanding actuation properties. The DEAs consist of a combination of different materials for the dielectric and electrode layers. The combination of these layers causes incompatibilities in their interconnections. Dramatic differences in the mechanical properties and bad adhesion of the layers are the principal causes for the reduction of the actuation displacement and strong reduction of lifetime. Common DEAs achieve actuation displacements of 2% and a durability of some million cycles. The following investigations represent a new approach to solving the problems of common systems. The investigated DEA consists of only one basic raw polymer, which was modified according to the required demands of each layer. The basic raw polymer was modified with single-walled carbon nanotubes or high-k ceramics, for example, lead magnesium niobate-lead titanate. The development of the full polymer DEA comprised the development of materials and technologies to realise a reproducible layer composition. It was proven that the full polymer actuator worked according to the theoretical rules. The investigated system achieved actuation displacements above 20% regarding thickness, outstanding interconnections at each layer without any failures, and durability above 3 million cycles without any indication of an impending malfunction.

  1. High-k Scattering and FIReTIP Diagnostic Upgrades for NSTX-U (United States)

    Barchfeld, Robert; Scott, Evan; Domier, Calvin; Muscatello, Christopher; Riemenschneider, Paul; Sohrabi, Mohammad; Luhmann, Neville; Ren, Yang; Kaita, Robert


    A major upgrade to the High-k Scattering system is underway on NSTX-U, which is being transformed from a primarily toroidal detection geometry (for kr measurements) to a poloidal detection geometry (for kθ measurements) in which a probe beam is launched from Bay G and collected on Bay L. Combined with an increase in probing frequency to 693 GHz, the poloidal wavenumber sensitivity has been extended from kθ = 7 cm-1 up to 40 cm-1. The system will be installed and commissioned in 2016 with an initial 4-channel receiver, with plans to eventually upgrade to an 8x2 configuration, which can probe the plasma from the core out to the edge of the pedestal region. The Far Infrared Tangential Interferometer/Polarimeter (FIReTIP) system is being upgraded with field programmable gate array (FPGA) electronics to support real time feedback density control, and will be installed on Bay G this fall. Design and implementation details regarding both diagnostics will be presented. Work supported in part by U.S. DOE Grant DE-FG02-99ER54518 and DE-AC02-09CH1146.

  2. Psychometrics and life history strategy: the structure and validity of the High K Strategy Scale. (United States)

    Copping, Lee T; Campbell, Anne; Muncer, Steven


    In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006) was distributed to a large British sample (n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

  3. Psychometrics and Life History Strategy: The Structure and Validity of the High K Strategy Scale

    Directory of Open Access Journals (Sweden)

    Lee T. Copping


    Full Text Available In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006 was distributed to a large British sample (n = 809 with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital. Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

  4. Backside versus frontside advanced chemical analysis of high-k/metal gate stacks

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E., E-mail: [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Saidi, B. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Veillerot, M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Caubet, P. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Fabbri, J-M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Piallat, F. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Gassilloud, R. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Schamm-Chardon, S. [CEMES-CNRS et Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France)


    Highlights: • The backside approach is a promising solution for advanced chemical characterization of future MOSFETs. • Frontside ToF-SIMS and Auger depth profiles are affected by cumulative mixing effects and thus not relevant for analyzing ultra-thin layers. • Higher in-depth resolution is possible in the backside approach for Auger and ToF-SIMS depth profiling. • Backside depth profiling allows revealing ultra-thin layers and elemental in-depth redistribution inside high-k/metal gate stacks. • Backside XPS allows preserving the full metal gate, thus enabling the analysis of real technological samples. - Abstract: Downscaling of transistors beyond the 14 nm technological node requires the implementation of new architectures and materials. Advanced characterization methods are needed to gain information about the chemical composition of buried layers and interfaces. An effective approach based on backside analysis is presented here. X-ray photoelectron spectroscopy, Auger depth profiling and time-of-flight secondary ions mass spectrometry are combined to investigate inter-diffusion phenomena. To highlight improvements related to the backside method, backside and frontside analyses are compared. Critical information regarding nitrogen, oxygen and aluminium redistribution inside the gate stacks is obtained only in the backside configuration.

  5. Diet after gastric banding (United States)

    Gastric banding surgery - your diet; Obesity - diet after banding; Weight loss - diet after banding ... about any problems you are having with your diet, or about other issues related to your surgery ...

  6. Ca dependence of Na influx during treatment of rabbit aorta with NE and high K solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aaronson, P.I.; Jones, A.W. (St. George' s Hospital Medical School, London (England) Univ. of Missouri School of Medicine, Columbia (USA))


    Cellular influx of {sup 24}Na was measured in isolated rabbit aorta during stimulation with 10 {mu}M norepinephrine (NE) or depolarization with 80 mM K solution, using a pulse-labeling, cold-wash technique. NE caused a two- to threefold increase in Na influx; a smaller but significant increase was also observed in depolarized tissues. Basal and Ne-induced fluxes at 1 min were significantly increased by a 20-min preincubation in a Ca-free solution containing 2 mM EGTA; elevation of (Mg) in this solution reduced these effects. The high K-induced influx was prevented by a combination of low Ca (30 {mu}m) and elevated Mg (10 mM). The Ca agonist, BAY-K 8644, increased {sup 24}Na influx. The Ca antagonist, diltiazem, inhibited the depolarization-stimulated {sup 24}Na influx in a concentration-dependent manner, but was less effective in blocking the response to NE. Extension of the preincubation in NE plus Ca-free medium from 30 s to 15 min decreased the influx response and contraction. After exposure to NE in Ca-free solution, {sup 24}Na influx remained elevated 10 min after washing out NE in the continued absence of Ca. A second exposure to NE at that time did not increase influx. The authors propose that a component of {sup 24}Na influx during excitation depends directly on a rise in intracellular (Ca). The role of an indirect effect of (Ca) on metabolic H{sup +} production with subsequent stimulation of the Na{sup +}-H{sup +} exchange may also be a factor.

  7. Advanced Composite High-k Gate Stack for Mixed Anion Arsenide-Antimonide Quantum Well Transistors (United States)


    and interface defect scattering5 dominate. Shubnikov-de Haas ( SdH ) oscillations (Fig. 8a) are observed at low temperature (2- 15K) and high magnetic...the amplitude of SdH oscillations, which is lower than 0.05m0 reported for InAs QW due to quantization and band non-parabolicity6. FFT of SdH ...ρ 0 1/B [T-1] 2K 4K 6K 10K 15K Δ(1/B) = 0.024 T -1 m*=.043m0 (b) Fig. 8 (a) Shubnikov-de Haas ( SdH ) oscillations in the sheet resistance

  8. Hetero-gate-dielectric double gate junctionless transistor (HGJLT) with reduced band-to-band tunnelling effects in subthreshold regime (United States)

    Ghosh, Bahniman; Mondal, Partha; Akram, M. W.; Bal, Punyasloka; Salimath, Akshay Kumar


    We propose a hetero-gate-dielectric double gate junctionless transistor (HGJLT), taking high-k gate insulator at source side and low-k gate insulator at drain side, which reduces the effects of band-to-band tunnelling (BTBT) in the sub-threshold region. A junctionless transistor (JLT) is turned off by the depletion of carriers in the highly doped thin channel (device layer) which results in a significant band overlap between the valence band of the channel region and the conduction band of the drain region, due to off-state drain bias, that triggers electrons to tunnel from the valence band of the channel region to the conduction band of the drain region leaving behind holes in the channel. These effects of band-to-band tunnelling increase the sub-threshold leakage current, and the accumulation of holes in the channel forms a parasitic bipolar junction transistor (n-p-n BJT for channel JLT) in the lateral direction by the source (emitter), channel (base) and drain (collector) regions in JLT structure in off-state. The proposed HGJLT reduces the subthreshold leakage current and suppresses the parasitic BJT action in off-state by reducing the band-to-band tunnelling probability.

  9. Physical understanding of different drain-induced-barrier-lowering variations in high-k/metal gate n-channel metal-oxide-semiconductor-field-effect-transistors induced by charge trapping under normal and reverse channel hot carrier stresses (United States)

    Luo, Weichun; Yang, Hong; Wang, Wenwu; Zhao, Lichuan; Xu, Hao; Ren, Shangqing; Tang, Bo; Tang, Zhaoyun; Xu, Yefeng; Xu, Jing; Yan, Jiang; Zhao, Chao; Chen, Dapeng; Ye, Tianchun


    In this paper, the drain induced barrier lowering (DIBL) variations in High-k/Metal gate n-channel metal-oxide-semiconductor field effect transistor under the normal and reverse channel hot carrier (CHC) stress are studied. It is found that DIBL decreases under normal CHC stress mode while increases under reverse CHC mode. The different DIBL variation under normal and reverse CHC stresses is proposed to be attributed to stress-induced charge trapping by cold carriers from the channel rather than hot carriers from the pinch off region, which can be explained by energy band bending theory.

  10. Experimental Determination of Major Element Diffusivity in Natural High-K Calc-alkaline Melts (United States)

    González-García, D.; Behrens, H.; Vetere, F. P.; Petrelli, M.; Zezza, A.; Morgavi, D.; Perugini, D.


    Chemical diffusion is of major importance in several magmatic processes and, as a time dependent process, can be used as a timescale indicator. In particular, the study of diffusive exchange in magma mixing events leading to explosive volcanic eruptions has the potential shed light on timescales involved in such processes. To achieve this, a basic knowledge of diffusion rates in different natural silicate melts with a variety of conditions is mandatory. We use a set of diffusion couple experiments to quantify the influence of dissolved water content in the interdiffusion of major elements between two natural high-K calc-alkaline end-members: a shoshonite and a rhyolite from Vulcano island (Aeolian archipelago, Italy). Experiments are run using AuPd alloy capsules at 1200 °C and pressures of 0.5, 1 and 3 kbar, with variable added water content (`nominally dry', 1wt. % and 2 wt.% H2O), and finished by a rapid quench in order to avoid crystal formation. Run products are analyzed by FTIR spectroscopy and electron microprobe, and final diffusion coefficients are obtained from the evaluation of composition-distance profiles by a modified Boltzmann-Matano analysis. Among measured major elements (Si, Ti, Al, Fe, Mg, Ca, K), dissolved H2O content in the melt has the highest influence in diffusivity in our experimental setup: a difference of up to 1.4 orders of magnitude is observed between 0.3 and 2 wt. % H2O bearing glasses. In the investigated range, enhancement of diffusion is higher in the lower water contents and slightly diminishes to 2 wt. %. Compositional gradients result in a 0.4 to 0.8 log units increase of diffusivity in the mafic terms relative to the silicic ones. Si and Ti are the slowest diffusing components. Al is also a slow diffusing component and displays uphill diffusion. The diffusivities of the other elements follow similar behavior, suggesting a strong influence of crossed diffusion and coupling.

  11. Probing/Manipulating the Interfacial Atomic Bonding between High k Dielectrics and InGaAs for Ultimate CMOS (United States)


    10.1039/C4CE00734D 2014 3. “III-V Compound Semiconductor Transistors – From Planar to Nanowire Structures”, H. Riel, L.-E. Wernersson, M. Hong, J...extract interface state densities at atomic-layer-deposited high-k dielectric/III-V heterostructures ”, Y. T. Fanchiang, Y. K. Su, K. S. Chen, Y. C

  12. Study of 6T SRAM cell using High-K gate dielectric based junctionless silicon nanotube FET (United States)

    Tayal, Shubham; Nandi, Ashutosh


    This paper investigates the performance of 6 T SRAM cell using high-K gate dielectric based junctionless silicon nanotube FET (JLSiNTFET). It is observed that the use of high-K gate dielectric enhances the delay performance of the JLSiNTFET based 6 T SRAM cell. Read access time (RAT) and write access time (WAT) improves by ∼18% and ∼20% when TiO2 is used as gate dielectric instead of SiO2. The hold, read, and write SNMs (static noise margin) of the 6 T SRAM cell also improves marginally by the use of high-K gate dielectric. Furthermore, it is also observed that the improvement in hold SNM (HSNM), read SNM (RSNM), and write SNM (WSNM) can be boosted by using higher interfacial layer thickness (TI). However, the improvement in read access times (RAT) & write access time (WAT) degrades at higher TI. Thus, high-K gate dielectrics with high interfacial layer thickness are more suitable for JLSiNT-FET based 6 T SRAM cell.

  13. Implementation of nanoscale circuits using dual metal gate engineered nanowire MOSFET with high-k dielectrics for low power applications (United States)

    Charles Pravin, J.; Nirmal, D.; Prajoon, P.; Ajayan, J.


    This work covers the impact of dual metal gate engineered Junctionless MOSFET with various high-k dielectric in Nanoscale circuits for low power applications. Due to gate engineering in junctionless MOSFET, graded potential is obtained and results in higher electron velocity of about 31% for HfO2 than SiO2 in the channel region, which in turn improves the carrier transport efficiency. The simulation is done using sentaurus TCAD, ON current, OFF current, ION/IOFF ratio, DIBL, gain, transconductance and transconductance generation factor parameters are analysed. When using HfO2, DIBL shows a reduction of 61.5% over SiO2. The transconductance and transconductance generation factor shows an improvement of 44% and 35% respectively. The gain and output resistance also shows considerable improvement with high-k dielectrics. Using this device, inverter circuit is implemented with different high-k dielectric material and delay have been decreased by 4% with HfO2 when compared to SiO2. In addition, a significant reduction in power dissipation of the inverter circuit is obtained with high-k dielectric Dual Metal Surround Gate Junctionless Transistor than SiO2 based device. From the analysis, it is found that HfO2 will be a better alternative for the future nanoscale device.

  14. Band structure of semiconductors

    CERN Document Server

    Tsidilkovski, I M


    Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

  15. Interface characterization of atomic layer deposited high-k on non-polar GaN (United States)

    Jia, Ye; Zeng, Ke; Singisetti, Uttam


    The interface properties between dielectrics and semiconductors are crucial for electronic devices. In this work, we report the electrical characterization of the interface properties between atomic layer deposited Al2O3 and HfO2 on non-polar a-plane ( 11 2 ¯ 0 ) and m-plane ( 1 1 ¯ 00 ) GaN grown by hybrid vapor phase epitaxy. A metal oxide semiconductor capacitor (MOSCAP) structure was used to evaluate the interface properties. The impact of annealing on the interface properties was also investigated. The border trap in the oxide, characterized by the capacitance-voltage (C-V) hysteresis loop, was low. The interface state density (Dit), extracted using the ac conductance method, is in the range of 0.5 × 1012/cm2 eV to 7.5 × 1011/cm2 eV within an energy range from 0.2 eV to 0.5 eV below the conduction band minimum. The m-plane GaN MOSCAPs exhibited better interface properties than the a-plane GaN MOSCAPs after annealing. Without annealing, Al2O3 dielectrics had higher border trap density and interface state density compared to HfO2 dielectrics. However, the annealing had different impacts on Al2O3 dielectrics as compared to HfO2. Our results showed that the annealing degraded the quality of the interface in HfO2, but it improved the quality of the interface in Al2O3 devices. The annealing also reduced the positive trapped oxide charge, resulting in a shift of C-V curves towards the positive bias region.

  16. Band parameters of phosphorene

    DEFF Research Database (Denmark)

    Lew Yan Voon, L. C.; Wang, J.; Zhang, Y.


    Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory...

  17. A new method of dielectric characterization in the microwave range for high-k ferroelectric thin films


    Nadaud, Kevin; Gundel, Hartmut,; Borderon, Caroline; Gillard, Raphaël; Fourn, Erwan


    International audience; In this paper we propose a new method of dielectric characterization of high-k thin films based on the measurement of coplanar capacitor inserts between two coplanar waveguide transmission lines. The measurement geometry is deposed on the thin film which is elaborate on an insulating substrate. The thin film permittivity is extracted with the help of a mathematical model describing the capacitance between two conductor plates deposed on a 2-layers substrate. A simple c...

  18. A Review on Resistive Switching in High-k Dielectrics: A Nanoscale Point of View Using Conductive Atomic Force Microscope

    Directory of Open Access Journals (Sweden)

    Mario Lanza


    Full Text Available Metal-Insulator-Metal (MIM structures have raised as the most promising configuration for next generation information storage, leading to great performance and fabrication-friendly Resistive Random Access Memories (RRAM. In these cells, the memory concept is no more based on the charge storage, but on tuning the electrical resistance of the insulating layer by applying electrical stresses to reach a high resistive state (HRS or “0” and a low resistive state (LRS or “1”, which makes the memory point. Some high-k dielectrics show this unusual property and in the last years high-k based RRAM have been extensively analyzed, especially at the device level. However, as resistance switching (in the most promising cells is a local phenomenon that takes place in areas of ~100 nm2, the use of characterization tools with high lateral spatial resolution is necessary. In this paper the status of resistive switching in high-k materials is reviewed from a nanoscale point of view by means of conductive atomic force microscope analyses.

  19. Integration of atomic layer deposited high-k dielectrics on GaSb via hydrogen plasma exposure

    Directory of Open Access Journals (Sweden)

    Laura B. Ruppalt


    Full Text Available In this letter we report the efficacy of a hydrogen plasma pretreatment for integrating atomic layer deposited (ALD high-k dielectric stacks with device-quality p-type GaSb(001 epitaxial layers. Molecular beam eptiaxy-grown GaSb surfaces were subjected to a 30 minute H2/Ar plasma treatment and subsequently removed to air. High-k HfO2 and Al2O3/HfO2 bilayer insulating films were then deposited via ALD and samples were processed into standard metal-oxide-semiconductor (MOS capacitors. The quality of the semiconductor/dielectric interface was probed by current-voltage and variable-frequency admittance measurements. Measurement results indicate that the H2-plamsa pretreatment leads to a low density of interface states nearly independent of the deposited dielectric material, suggesting that pre-deposition H2-plasma exposure, coupled with ALD of high-k dielectrics, may provide an effective means for achieving high-quality GaSb MOS structures for advanced Sb-based digital and analog electronics.

  20. Application of an empirical saturation rule to TGLF to unify low-k and high-k turbulence dominated regimes (United States)

    Jian, Xiang; Chan, Vincent S.; Chen, Jiale; Li, Zeyu; Garofalo, Andrea M.; Zhuang, Ge; the CFETR Physics team


    We propose a phenomenological turbulence saturation model and apply it to the TGLF turbulence transport model (Staebler et al 2007 Phys. Plasmas 14 055909), which captures the physics of interaction between low-k and high-k turbulence consistent with the multi-scale gyro-kinetic simulation result reported by Howard (2016 Nucl. Fusion. 23 056109). The new model, TGLF-Vx is tested with three discharges from DIII-D and EAST tokamak, which cover both low-k and high-k turbulence dominated regimes. It is found that the profile match can be substantially improved over previous models when evolving T e, T i and n e simultaneously. Good agreement for all three discharges is obtained with one fixed parameter in the model when taking experimental uncertainties into consideration. Lastly, TGLF-Vx is applied to explore the sensitivity of the predicted CFETR steady-state performance to different transport models. Our result shows that a scenario using only RF auxiliary heating could be significantly affected.

  1. Towards low-voltage organic thin film transistors (OTFTs with solution-processed high-k dielectric and interface engineering

    Directory of Open Access Journals (Sweden)

    Yaorong Su


    Full Text Available Although impressive progress has been made in improving the performance of organic thin film transistors (OTFTs, the high operation voltage resulting from the low gate capacitance density of traditional SiO2 remains a severe limitation that hinders OTFTs'development in practical applications. In this regard, developing new materials with high-k characteristics at low cost is of great scientific and technological importance in the area of both academia and industry. Here, we introduce a simple solution-based technique to fabricate high-k metal oxide dielectric system (ATO at low-temperature, which can be used effectively to realize low-voltage operation of OTFTs. On the other hand, it is well known that the properties of the dielectric/semiconductor and electrode/semiconductor interfaces are crucial in controlling the electrical properties of OTFTs. By optimizing the above two interfaces with octadecylphosphonic acid (ODPA self-assembled monolayer (SAM and properly modified low-cost Cu, obviously improved device performance is attained in our low-voltage OTFTs. Further more, organic electronic devices on flexible substrates have attracted much attention due to their low-cost, rollability, large-area processability, and so on. Basing on the above results, outstanding electrical performance is achieved in flexible devices. Our studies demonstrate an effective way to realize low-voltage, high-performance OTFTs at low-cost.

  2. Low-voltage Organic Thin Film Transistors (OTFTs) with Solution-processed High-k Dielectric cum Interface Engineering (United States)

    Su, Yaorong

    Although impressive progress has been made in improving the performance of organic thin film transistors (OTFTs), the high operation voltage resulting from the low gate areal capacitance of traditional SiO 2 remains a severe limitation that hinders OTFTs' development in practical applications. In this regard, developing new materials with high- k characteristics at low cost is of great scientific and technological importance in the area of both academia and industry. In this thesis, we first describe a simple solution-based method to fabricate a high-k bilayer Al2Oy/TiOx (ATO) dielectric system at low temperature. Then the dielectric properties of the ATO are characterized and discussed in detail. Furthermore, by employing the high-k ATO as gate dielectric, low-voltage copper phthalocyanine (CuPc) based OTFTs are successfully developed. Interestingly, the obtained low-voltage CuPc TFT exhibits outstanding electrical performance, which is even higher than the device fabricated on traditional low-k SiO2. The above results seem to be contradictory to the reported results due to the fact that high-k usually shows adverse effect on the device performance. This abnormal phenomenon is then studied in detail. Characterization on the initial growth shows that the CuPc molecules assemble in a "rod-like" nano crystal with interconnected network on ATO, which probably promotes the charge carrier transport, whereas, they form isolated small islands with amorphous structure on SiO2. In addition, a better metal/organic contact is observed on ATO, which benefits the charge carrier injection. Our studies suggest that the low-temperature, solution-processed high-k ATO is a promising candidate for fabrication of high-performance, low-voltage OTFTs. Furthermore, it is well known that the properties of the dielectric/semiconductor and electrode/semiconductor interfaces are crucial in controlling the electrical properties of OTFTs. Hence, investigation the effects of interfaces

  3. Singing with the Band (United States)

    Altman, Timothy Meyer; Wright, Gary K.


    Usually band, orchestra, and choir directors work independently. However, the authors--one a choral director, the other a band director--have learned that making music together makes friends. Not only can ensemble directors get along, but joint concerts may be just the way to help students see how music can reach the heart. Combined instrumental…


    NARCIS (Netherlands)



    Banding techniques were carried out on metaphase chromosomes of zebrafish (Danio rerio) embryos. The karyotypes with the longest chromosomes consist of 12 metacentrics, 26 submetacentrics, and 12 subtelocentrics (2n = 50). All centromeres are C-band positive. Eight chromosomes have a pericentric

  5. Infrared diffuse interstellar bands (United States)

    Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.


    We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

  6. Investigation of Dependence between Time-zero and Time-dependent Variability in High-k NMOS Transistors

    CERN Document Server

    Hassan, Mohammad Khaled


    Bias Temperature Instability (BTI) is a major reliability concern in CMOS technology, especially with High dielectric constant (High-\\k{appa}/HK) metal gate (MG) transistors. In addition, the time independent process induced variation has also increased because of the aggressive scaling down of devices. As a result, the faster devices at the lower threshold voltage distribution tail experience higher stress, leading to additional skewness in the BTI degradation. Since time dependent dielectric breakdown (TDDB) and stress-induced leakage current (SILC) in NMOS devices are correlated to BTI, it is necessary to investigate the effect of time zero variability on all these effects simultaneously. To that effect, we propose a simulation framework to model and analyze the impact of time-zero variability (in particular, random dopant fluctuations) on different aging effects. For small area devices (~1000 nm2) in 30nm technology, we observe significant effect of Random Dopant Fluctuation (RDF) on BTI induced variabili...

  7. Net K+ secretion in the thick ascending limb of mice on a low-Na, high-K diet. (United States)

    Wang, Bangchen; Wen, Donghai; Li, Huaqing; Wang-France, Jun; Sansom, Steven C


    Because of its cardio-protective effects, a low-Na, high-K diet (LNaHK) is often warranted in conjunction with diuretics to treat hypertensive patients. However, it is necessary to understand the renal handling of such diets in order to choose the best diuretic. Wild-type (WT) or Renal Outer Medullary K channel (ROMK) knockout mice (KO) were given a regular (CTRL), LNaHK, or high-K diet (HK) for 4-7 days. On LNaHK, mice treated with either IP furosemide for 12 hrs, or given furosemide in drinking water for 7 days, exhibited decreased K clearance. We used free-flow micropuncture to measure the [K+] in the early distal tubule (EDT [K+]) before and after furosemide treatment. Furosemide increased the EDT [K+] in WT on CTRL but decreased that in WT on LNaHK. Furosemide did not affect the EDT [K+] of KO on LNaHK or WT on HK. Furosemide-sensitive Na+ excretion was significantly greater in mice on LNaHK than those on CTRL or HK. Patch clamp analysis of split-open TALs revealed that 70-pS ROMK exhibited a higher open probability (Po) but similar density in mice on LNaHK, compared with CTRL. No difference was found in the density or Po of the 30 pS K channels between the two groups. These results indicate mice on LNaHK exhibited furosemide-sensitive net K+ secretion in the TAL that is dependent on increased NKCC2 activity and mediated by ROMK. We conclude that furosemide is a K-sparing diuretic by decreasing the TAL net K+ secretion in subjects on LNaHK. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  8. Laparoscopic gastric banding - discharge (United States)

    ... heart disease Gastric bypass surgery Laparoscopic gastric banding Obesity Obstructive sleep apnea - adults Type 2 diabetes Patient Instructions Weight-loss surgery - after - what to ask your doctor Weight- ...

  9. Restrictive techniques: gastric banding

    Directory of Open Access Journals (Sweden)

    Katia Cristina da Cunha


    Full Text Available Surgery for the treatment of severe obesity has a definite role onthe therapeutic armamentarium all over the world. Initiated 40years ago, bariatric surgery has already a long way thanks tohundred of surgeons, who had constantly searched for the besttechnique for the adequate control of severe obesity. Among theimportant breakthroughs in obesity surgery there is theadjustable gastric band. It is a sylastic band, inflatable andadjustable, which is placed on the top of the stomach in order tocreate a 15-20 cc pouch, with an outlet of 1.3cm. The adjustablegastric band has also a subcutaneous reservoir through whichadjustments can be made, according to the patient evolution.The main feature of the adjustable gastric band is the fact thatis minimal invasive, reversible, adjustable and placedlaparoscopically. Then greatly diminishing the surgical traumato the severe obese patient. Belachew and Favretti’s techniqueof laparoscopic application of the adjustable gastric band isdescribed and the evolution of the technique during this years,as we has been practiced since 1998. The perioperative care ofthe patient is also described, as well as the follow-up and shortand long term controls.

  10. Hole mobility modulation of solution-processed nickel oxide thin-film transistor based on high-k dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ao; Liu, Guoxia, E-mail:, E-mail:; Zhu, Huihui; Shan, Fukai, E-mail:, E-mail: [College of Physics, Qingdao University, Qingdao 266071 (China); College of Electronics and Information Engineering, Qingdao University, Qingdao 266071 (China); Lab of New Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Shin, Byoungchul [Electronic Ceramics Center, DongEui University, Busan 614-714 (Korea, Republic of); Fortunato, Elvira; Martins, Rodrigo [Department of Materials Science/CENIMAT-I3N, Faculty of Sciences and Technology, New University of Lisbon and CEMOP-UNINOVA, Campus de Caparica, 2829-516 Caparica (Portugal)


    Solution-processed p-type oxide semiconductors have recently attracted increasing interests for the applications in low-cost optoelectronic devices and low-power consumption complementary metal-oxide-semiconductor circuits. In this work, p-type nickel oxide (NiO{sub x}) thin films were prepared using low-temperature solution process and integrated as the channel layer in thin-film transistors (TFTs). The electrical properties of NiO{sub x} TFTs, together with the characteristics of NiO{sub x} thin films, were systematically investigated as a function of annealing temperature. By introducing aqueous high-k aluminum oxide (Al{sub 2}O{sub 3}) gate dielectric, the electrical performance of NiO{sub x} TFT was improved significantly compared with those based on SiO{sub 2} dielectric. Particularly, the hole mobility was found to be 60 times enhancement, quantitatively from 0.07 to 4.4 cm{sup 2}/V s, which is mainly beneficial from the high areal capacitance of the Al{sub 2}O{sub 3} dielectric and high-quality NiO{sub x}/Al{sub 2}O{sub 3} interface. This simple solution-based method for producing p-type oxide TFTs is promising for next-generation oxide-based electronic applications.

  11. Comprehensive study and design of scaled metal/high-k/Ge gate stacks with ultrathin aluminum oxide interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Asahara, Ryohei; Hideshima, Iori; Oka, Hiroshi; Minoura, Yuya; Hosoi, Takuji, E-mail:; Shimura, Takayoshi; Watanabe, Heiji [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ogawa, Shingo [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Toray Research Center Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567 (Japan); Yoshigoe, Akitaka; Teraoka, Yuden [Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)


    Advanced metal/high-k/Ge gate stacks with a sub-nm equivalent oxide thickness (EOT) and improved interface properties were demonstrated by controlling interface reactions using ultrathin aluminum oxide (AlO{sub x}) interlayers. A step-by-step in situ procedure by deposition of AlO{sub x} and hafnium oxide (HfO{sub x}) layers on Ge and subsequent plasma oxidation was conducted to fabricate Pt/HfO{sub 2}/AlO{sub x}/GeO{sub x}/Ge stacked structures. Comprehensive study by means of physical and electrical characterizations revealed distinct impacts of AlO{sub x} interlayers, plasma oxidation, and metal electrodes serving as capping layers on EOT scaling, improved interface quality, and thermal stability of the stacks. Aggressive EOT scaling down to 0.56 nm and very low interface state density of 2.4 × 10{sup 11 }cm{sup −2}eV{sup −1} with a sub-nm EOT and sufficient thermal stability were achieved by systematic process optimization.

  12. Two methods of tuning threshold voltage of bulk FinFETs with replacement high-k metal-gate stacks (United States)

    Xu, Miao; Zhu, Huilong; Zhang, Yanbo; Xu, Qiuxia; Zhang, Yongkui; Qin, Changliang; Zhang, Qingzhu; Yin, Huaxiang; Xu, Hao; Chen, Shuai; Luo, Jun; Li, Chunlong; Zhao, Chao; Ye, Tianchun


    In this work, we propose two threshold voltage (VTH) tuning methods for bulk FinFETs with replacement high-k metal gate. The first method is to perform a vertical implantation into fin structure after dummy gate removal, self-aligned forming halo & punch through stop pocket (halo & PTSP) doping profile. The second method is to execute P+/BF2+ ion implantations into the single common work function (WF) layer in N-/P-FinFETs, respectively. These two methods have been investigated by TCAD simulations and MOS-capacitor experiments respectively, and then integrated into FinFET fabrication successfully. Experimental results show that the halo & PTSP doping profile can reduce VTH roll off and total variation. With P+/BF2+ doped WF layer, the VTH-sat shift -0.43 V/+1.26 V for N-FinFETs and -0.75 V/+0.11 V for P-FinFETs, respectively, with gate length of 500 nm. The proposed two methods are simple and effective for FinFET VTH tuning, and have potential for future application of massive production.

  13. The fabrication and the reliability of poly-Si MOSFETs using ultra-thin high-K/metal-gate stack (United States)

    Lee, M. H.; Chen, K.-J.


    Poly-Si MOSFETs using a gate stack composed of ultra-thin HfSiOx and TiN are shown, and they are compatible with a monolithic three-dimensional integrated circuit (3D-ICs) process with the highest thermal budget of 700 °C. The poly-Si MOSFETs were studied for fabrication process temperatures with parasitic resistance, effective gate length, and grain boundary trap density. The short-channel effect with VT (threshold voltage), subthreshold swing (SS), and drain-induced barrier lowering (DIBL) was also compared at 650 °C and 700 °C. For stress reliability of both hot carrier and PBTI, the short-channel devices showed more stability in VT than the long-channel devices due to less grain boundary scattering. This study promotes the ultra-thin high-K/metal gate poly-Si MOSFET as a candidate for future monolithic 3D-ICs and silicon-on-glass (SOG) applications.

  14. Ultra wide band antennas

    CERN Document Server

    Begaud, Xavier


    Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

  15. Amniotic band syndrome. (United States)

    Shetty, Prathvi; Menezes, Leo Theobald; Tauro, Leo Francis; Diddigi, Kumar Arun


    Amniotic band syndrome is an uncommon congenital disorder without any genetic or hereditary disposition. It involves fetal entrapment in strands of amniotic tissue and causes an array of deletions and deformations. Primary treatment is plastic and reconstructive surgery after birth with in utero fetal surgery also coming in vogue.

  16. Amniotic Band Syndrome


    Shetty, Prathvi; Menezes, Leo Theobald; Tauro, Leo Francis; Diddigi, Kumar Arun


    Amniotic band syndrome is an uncommon congenital disorder without any genetic or hereditary disposition. It involves fetal entrapment in strands of amniotic tissue and causes an array of deletions and deformations. Primary treatment is plastic and reconstructive surgery after birth with in utero fetal surgery also coming in vogue.

  17. Colloquium: Topological band theory (United States)

    Bansil, A.; Lin, Hsin; Das, Tanmoy


    The first-principles band theory paradigm has been a key player not only in the process of discovering new classes of topologically interesting materials, but also for identifying salient characteristics of topological states, enabling direct and sharpened confrontation between theory and experiment. This review begins by discussing underpinnings of the topological band theory, which involve a layer of analysis and interpretation for assessing topological properties of band structures beyond the standard band theory construct. Methods for evaluating topological invariants are delineated, including crystals without inversion symmetry and interacting systems. The extent to which theoretically predicted properties and protections of topological states have been verified experimentally is discussed, including work on topological crystalline insulators, disorder and interaction driven topological insulators (TIs), topological superconductors, Weyl semimetal phases, and topological phase transitions. Successful strategies for new materials discovery process are outlined. A comprehensive survey of currently predicted 2D and 3D topological materials is provided. This includes binary, ternary, and quaternary compounds, transition metal and f -electron materials, Weyl and 3D Dirac semimetals, complex oxides, organometallics, skutterudites, and antiperovskites. Also included is the emerging area of 2D atomically thin films beyond graphene of various elements and their alloys, functional thin films, multilayer systems, and ultrathin films of 3D TIs, all of which hold exciting promise of wide-ranging applications. This Colloquium concludes by giving a perspective on research directions where further work will broadly benefit the topological materials field.

  18. Silicon nanowires with high-k hafnium oxide dielectrics for sensitive detection of small nucleic acid oligomers. (United States)

    Dorvel, Brian R; Reddy, Bobby; Go, Jonghyun; Duarte Guevara, Carlos; Salm, Eric; Alam, Muhammad Ashraful; Bashir, Rashid


    Nanobiosensors based on silicon nanowire field effect transistors offer advantages of low cost, label-free detection, and potential for massive parallelization. As a result, these sensors have often been suggested as an attractive option for applications in point-of-care (POC) medical diagnostics. Unfortunately, a number of performance issues, such as gate leakage and current instability due to fluid contact, have prevented widespread adoption of the technology for routine use. High-k dielectrics, such as hafnium oxide (HfO(2)), have the known ability to address these challenges by passivating the exposed surfaces against destabilizing concerns of ion transport. With these fundamental stability issues addressed, a promising target for POC diagnostics and SiNWFETs has been small oligonucleotides, more specifically, microRNA (miRNA). MicroRNAs are small RNA oligonucleotides which bind to mRNAs, causing translational repression of proteins, gene silencing, and expressions are typically altered in several forms of cancer. In this paper, we describe a process for fabricating stable HfO(2) dielectric-based silicon nanowires for biosensing applications. Here we demonstrate sensing of single-stranded DNA analogues to their microRNA cousins using miR-10b and miR-21 as templates, both known to be upregulated in breast cancer. We characterize the effect of surface functionalization on device performance using the miR-10b DNA analogue as the target sequence and different molecular weight poly-l-lysine as the functionalization layer. By optimizing the surface functionalization and fabrication protocol, we were able to achieve <100 fM detection levels of the miR-10b DNA analogue, with a theoretical limit of detection of 1 fM. Moreover, the noncomplementary DNA target strand, based on miR-21, showed very little response, indicating a highly sensitive and highly selective biosensing platform.

  19. Solution-processed polymer-sorted semiconducting carbon nanotube network transistors with low-k /high-k bilayer polymer dielectrics (United States)

    Lee, Seung-Hoon; Kim, Dong-Yu; Noh, Yong-Young


    Solution-processed semiconducting carbon nanotube transistors with a high mobility and an ON/OFF ratio are the most promising for use in flexible electronics. In this paper, we report low-k/high-k bilayer polymer dielectrics for solution-processed semiconducting single-walled carbon nanotube (s-SWNT) field-effect transistors (s-SWNT-FETs) with efficient charge transport and operation at low voltage. Thin low-k polystyrene (10 nm) is used for the first contact insulator with a channel in order to passivate the dipolar disorder induced by high-k insulators. The second gate insulator for low voltage operation is cyanoethyl pullulan (CEP), which is an environmentally friendly high-k insulator based on cellulose. Moreover, poly[(vinylidenefluoride-co-trifluoroethylene) is chosen as a single layer dielectric for comparison. A reasonably low operational voltage (insulator is of critical importance for efficient charge transport.

  20. A simulation-based proposed high-k heterostructure AlGaAs/Si junctionless n-type tunnel FET (United States)

    Balmukund Rahi, Shiromani; Ghosh, Bahniman; Asthana, Pranav


    We propose a heterostructure junctionless tunnel field effect transistor (HJL-TFET) using AlGaAs/Si. In the proposed HJL-TFET, low band gap silicon is used in the source side and higher band gap AlGaAs in the drain side. The whole AlGaAs/Si region is heavily doped n-type. The proposed HJL-TFET uses two isolated gates (named gate, gate1) with two different work functions (gate = 4.2 eV, gate1 = 5.2 eV respectively). The 2-D nature of HJL-TFET current flow is studied. The proposed structure is simulated in Silvaco with different gate dielectric materials. This structure exhibits a high on current in the range of 1.4 × 10-6 A/μm, the off current remains as low as 9.1 × 10-14 A/μm. So ION/IOFF ratio of ≃ 108 is achieved. Point subthreshold swing has also been reduced to a value of ≃ 41 mV/decade for TiO2 gate material.

  1. The hierarchically organized splitting of chromosome bands into sub-bands analyzed by multicolor banding (MCB). (United States)

    Lehrer, H; Weise, A; Michel, S; Starke, H; Mrasek, K; Heller, A; Kuechler, A; Claussen, U; Liehr, T


    To clarify the nature of chromosome sub-bands in more detail, the multicolor banding (MCB) probe-set for chromosome 5 was hybridized to normal metaphase spreads of GTG band levels at approximately 850, approximately 550, approximately 400 and approximately 300. It could be observed that as the chromosomes became shorter, more of the initial 39 MCB pseudo-colors disappeared, ending with 18 MCB pseudo-colored bands at the approximately 300-band level. The hierarchically organized splitting of bands into sub-bands was analyzed by comparing the disappearance or appearance of pseudo-color bands of the four different band levels. The regions to split first are telomere-near, centromere-near and in 5q23-->q31, followed by 5p15, 5p14, and all GTG dark bands in 5q apart from 5q12 and 5q32 and finalized by sub-band building in 5p15.2, 5q21.2-->q21.3, 5q23.1 and 5q34. The direction of band splitting towards the centromere or the telomere could be assigned to each band separately. Pseudo-colors assigned to GTG-light bands were resistant to band splitting. These observations are in concordance with the recently proposed concept of chromosome region-specific protein swelling. Copyright 2003 S. Karger AG, Basel


    Directory of Open Access Journals (Sweden)

    Jovana Đorđević


    Full Text Available Amniotic band syndrome (ABS is a set of congenital malformations attributed to amniotic bands that entangle fetal parts during intrauterine life, which results in a broad spectrum of anatomic disturbances - ranging from minor constriction rings and lymphedema of the digits to complex, bizarre multiple congenital anomalies incompatible with life. ABS is not very often, but should be considered in every newborn with congenital anomalies, especially defects of extremities and/or body walls. ABS can be diagnosed prenatally by ultrasound; otherwise, the defects are seen after birth. Child's karyotyping is of great importance, in order to avoid misdiagnosis and incorrect information of recurrence risk. A team of specialists should be included in the treatment and follow-up of children with ABS, according to individual needs of every single patient.The aim of this paper is to point out diagnostic and therapeutic approaches in newborns with ABS trough the report of two cases.

  3. Simulation design of high reverse blocking high-K/low-K compound passivation AlGaN/GaN Schottky barrier diode with gated edge termination (United States)

    Bai, Zhiyuan; Du, Jiangfeng; Xin, Qi; Li, Ruonan; Yu, Qi


    In this paper, a novel high-K/low-K compound passivation AlGaN/GaN Schottky Barrier Diode (CPG-SBD) is proposed to improve the off-state characteristics of AlGaN/GaN schottky barrier diode with gated edge termination (GET-SBD) by adding low-K blocks in to the high-K passivation layer. The reverse leakage current of CPG-SBD can be reduced to 1.6 nA/mm by reducing the thickness of high-K dielectric under GET region to 5 nm, while the forward voltage and on-state resistance keep 1 V and 3.8 Ω mm, respectively. Breakdown voltage of CPG-SBDs can be improved by inducing discontinuity of the electric field at the high-K/low-K interface. The breakdown voltage of the optimized CPG-SBD with 4 blocks of low-K can reach 1084 V with anode to cathode distance of 5 μm yielding a high FOM of 5.9 GW/cm2. From the C-V simulation results, CPG-SBDs induce no parasitic capacitance by comparison of the GET-SBDs.

  4. Noise exposure in marching bands (United States)

    Keefe, Joseph


    Previous studies involving orchestras have shown that music ensembles can produce hazardous noise levels. There are no similar data for marching bands and pep bands. In order to evaluate the noise levels produced by marching and pep bands, 1/3-octave-band sound-pressure levels were measured while these groups rehearsed and performed. Data were collected while marching with the bands to ensure a realistic environment. Comparing these data to OSHA and NIOSH criteria, marching and pep band exposures often exceed safe values. For typical exposures, OSHA doses range from 11% to 295%, while NIOSH doses range from 35% to 3055%. Exposures that would be considered hazardous in the workplace are common in marching and pep bands; students and band directors should take steps to recognize the risk posed by various instruments and various locations, and should implement hearing conservation efforts.

  5. A multitude of rotational bands in {sup 163}Er and their mutual interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bosetti, P.; Leoni, S.; Bracco, A. [Univ. of Milan (Italy)] [and others


    Using the {sup 150}Nd({sup 18}O, 5n){sup 163}Er reaction a multitude of rotational bands have been established with firm spin and parity assignments in {sup 163}Er. In 16 out of {approximately} 23 band crossings E2 cross-band transitions have been observed. The interaction strength varies between {approximately} 1 and {approximately} 50 keV. These interactions sample a variety of the lowest (multi)-quasiparticle configurations. Some of the band configurations, in particular those with high K-values, can be rather well established. Quite complicated changes in the wavefunctions must occur at these crossings, and, to explain the observed interaction strengths, one may have to invoke coupling to various vibrational degrees of freedom, in addition to possible residual neutron-proton interactions.

  6. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are ...

  7. Semiconductors bonds and bands

    CERN Document Server

    Ferry, David K


    As we settle into this second decade of the twenty-first century, it is evident that the advances in micro-electronics have truly revolutionized our day-to-day lifestyle. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors. It describes how quantum mechanics gives semiconductors unique properties that enabled the micro-electronics revolution, and sustain the ever-growing importance of this revolution.

  8. Morphologies of omega band auroras (United States)

    Sato, Natsuo; Yukimatu, Akira Sessai; Tanaka, Yoshimasa; Hori, Tomoaki


    We examined the morphological signatures of 315 omega band aurora events observed using the Time History of Events and Macroscale Interactions during Substorm ground-based all-sky imager network over a period of 8 years. We find that omega bands can be classified into the following three subtypes: (1) classical (O-type) omega bands, (2) torch or tongue (T-type) omega bands, and (3) combinations of classical and torch or tongue (O/T-type) omega bands. The statistical results show that T-type bands occur the most frequently (45%), followed by O/T-type bands (35%) and O-type bands (18%). We also examined the morphologies of the omega bands during their formation, from the growth period to the declining period through the maximum period. Interestingly, the omega bands are not stable, but rather exhibit dynamic changes in shape, intensity, and motion. They grow from small-scale bumps (seeds) at the poleward boundary of preexisting east-west-aligned auroras, rather than via the rotation or shear motion of preexisting east-west-aligned auroras, and do not exhibit any shear motion during the periods of auroral activity growth. Furthermore, the auroral luminosity is observed to increase during the declining period, and the total time from the start of the growth period to the end of the declining period is found to be about 20 min. Such dynamical signatures may be important in determining the mechanism responsible for omega band formation.

  9. Wide Band Artificial Pulsar (United States)

    Parsons, Zackary


    The Wide Band Artificial Pulsar (WBAP) is an instrument verification device designed and built by the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virgina. The site currently operates the Green Bank Ultimate Pulsar Processing Instrument (GUPPI) and the Versatile Green Bank Astronomical Spectrometer (VEGAS) digital backends for their radio telescopes. The commissioning and continued support for these sophisticated backends has demonstrated a need for a device capable of producing an accurate artificial pulsar signal. The WBAP is designed to provide a very close approximation to an actual pulsar signal. This presentation is intended to provide an overview of the current hardware and software implementations and to also share the current results from testing using the WBAP.

  10. Dark Bands on Europa (United States)


    Dark crisscrossing bands on Jupiter's moon Europa represent widespread disruption from fracturing and the possible eruption of gases and rocky material from the moon's interior in this four-frame mosaic of images from NASA's Galileo spacecraft. These and other features suggest that soft ice or liquid water was present below the ice crust at the time of disruption. The data do not rule out the possibility that such conditions exist on Europa today. The pictures were taken from a distance of 156,000 kilometers (about 96,300 miles) on June 27, 1996. Many of the dark bands are more than 1,600 kilometers (1,000 miles) long, exceeding the length of the San Andreas fault of California. Some of the features seen on the mosaic resulted from meteoritic impact, including a 30- kilometer (18.5 mile) diameter crater visible as a bright scar in the lower third of the picture. In addition, dozens of shallow craters seen in some terrains along the sunset terminator zone (upper right shadowed area of the image) are probably impact craters. Other areas along the terminator lack craters, indicating relatively youthful surfaces, suggestive of recent eruptions of icy slush from the interior. The lower quarter of the mosaic includes highly fractured terrain where the icy crust has been broken into slabs as large as 30 kilometers (18.5 miles) across. The mosaic covers a large part of the northern hemisphere and includes the north pole at the top of the image. The sun illuminates the surface from the left. The area shown is centered on 20 degrees north latitude and 220 degrees west longitude and is about as wide as the United States west of the Mississippi River. The Galileo mission is managed by NASA's Jet Propulsion Laboratory.

  11. A threshold-voltage model for small-scaled GaAs nMOSFET with stacked high-k gate dielectric (United States)

    Chaowen, Liu; Jingping, Xu; Lu, Liu; Hanhan, Lu; Yuan, Huang


    A threshold-voltage model for a stacked high-k gate dielectric GaAs MOSFET is established by solving a two-dimensional Poisson's equation in channel and considering the short-channel, DIBL and quantum effects. The simulated results are in good agreement with the Silvaco TCAD data, confirming the correctness and validity of the model. Using the model, impacts of structural and physical parameters of the stack high-k gate dielectric on the threshold-voltage shift and the temperature characteristics of the threshold voltage are investigated. The results show that the stacked gate dielectric structure can effectively suppress the fringing-field and DIBL effects and improve the threshold and temperature characteristics, and on the other hand, the influence of temperature on the threshold voltage is overestimated if the quantum effect is ignored. Project supported by the National Natural Science Foundation of China (No. 61176100).

  12. From surface to volume plasmons in hyperbolic metamaterials: General existence conditions for bulk high-k waves in metal-dielectric and graphene-dielectric multilayers

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Andryieuski, Andrei; Sipe, John E.


    -dielectric and recently introduced graphene-dielectric stacks. We confirm that short-range surface plasmons in thin metal layers can give rise to hyperbolic metamaterial properties and demonstrate that long-range surface plasmons cannot. We also show that graphene-dielectric multilayers tend to support high- k waves...... and explore the range of parameteres for which this is possible, confirming the prospects of using graphene for materials with hyperbolic dispersion. The approach is applicable to a large variety of structures, such as continuous or structured microwave, terahertz, and optical metamaterials.......We theoretically investigate general existence conditions for broadband bulk large-wave-vector (high- k ) propagating waves (such as volume plasmon polaritons in hyperbolic metamaterials) in subwavelength periodic multilayer structures. Describing the elementary excitation in the unit cell...

  13. Pentacene based thin film transistors with high-k dielectric Nd{sub 2}O{sub 3} as a gate insulator

    Energy Technology Data Exchange (ETDEWEB)

    Sarma, R.; Saikia, D. [J B College, Jorhat, Assam (India). Dept. of Physics. Thin Film Lab.; Saikia, Puja; Saikia, P.K.; Baishya, B., E-mail: [Dibrugarh University, Dibrugarh, Assam (India)


    We have investigated the pentacene based Organic Thin Film Transistors (OTFTs) with high-k dielectric Nd{sub 2}O{sub 3}. Use of high dielectric constant (high-k) gate insulator Nd{sub 2}O{sub 3} reduces the threshold voltage and sub threshold swing of the OTFTs. The calculated threshold voltage -2.2V and sub-threshold swing 1V/decade, current ON-OFF ratio is 1.7 X 10{sup 4} and mobility is 0.13cm{sup 2}/V.s. Pentacene film is deposited on Nd{sub 2}O{sub 3} surface using two step deposition method. Deposited pentacene film is found poly crystalline in nature. (author)

  14. Design of high breakdown voltage vertical GaN p-n diodes with high-K/low-K compound dielectric structure for power electronics applications (United States)

    Du, Jiangfeng; Li, Zhenchao; Liu, Dong; Bai, Zhiyuan; Liu, Yang; Yu, Qi


    In this work, a vertical GaN p-n diode with a high-K/low-K compound dielectric structure (GaN CD-VGD) is proposed and designed to achieve a record high breakdown voltage (BV) with a low specific on-resistance (Ron,sp). By introducing compound dielectric structure, the electric field near the p-n junction interface is suppressed due to the effects of high-K passivation layer, and a new electric field peak is induced into the n-type drift region, because of a discontinuity of electrical field at the interface of high-K and low-K layer. Therefore the distribution of electric field in GaN p-n diode becomes more uniform and an enhancement of breakdown voltage can be achieved. Numerical simulations demonstrate that GaN CD-VGD with a BV of 10650 V and a Ron,sp of 14.3 mΩ cm2, resulting in a record high figure-of-merit of 8 GW/cm2.

  15. Improved Band-to-Band Registration Characterization for VIIRS Reflective Solar Bands Based on Lunar Observations

    Directory of Open Access Journals (Sweden)

    Zhipeng Wang


    Full Text Available Spectral bands of the Visible Infrared Imaging Radiometer Suite (VIIRS instrument aboard the Suomi National Polar-orbiting Partnership (S-NPP satellite are spatially co-registered. The accuracy of the band-to-band registration (BBR is one of the key spatial parameters that must be characterized. Unlike its predecessor, the Moderate Resolution Imaging Spectroradiometer (MODIS, VIIRS has no on-board calibrator specifically designed to perform on-orbit BBR characterization. To circumvent this problem, a BBR characterization method for VIIRS reflective solar bands (RSB based on regularly-acquired lunar images has been developed. While its results can satisfactorily demonstrate that the long-term stability of the BBR is well within ±0.1 moderate resolution band pixels, undesired seasonal oscillations have been observed in the trending. The oscillations are most obvious between the visible/near-infrared bands and short-/middle wave infrared bands. This paper investigates the oscillations and identifies their cause as the band/spectral dependence of the centroid position and the seasonal rotation of the lunar images over calibration events. Accordingly, an improved algorithm is proposed to quantify the rotation and compensate for its impact. After the correction, the seasonal oscillation in the resulting BBR is reduced from up to 0.05 moderate resolution band pixels to around 0.01 moderate resolution band pixels. After removing this spurious seasonal oscillation, the BBR, as well as its long-term drift are well determined.

  16. Band calculation of lonsdaleite Ge (United States)

    Chen, Pin-Shiang; Fan, Sheng-Ting; Lan, Huang-Siang; Liu, Chee Wee


    The band structure of Ge in the lonsdaleite phase is calculated using first principles. Lonsdaleite Ge has a direct band gap at the Γ point. For the conduction band, the Γ valley is anisotropic with the low transverse effective mass on the hexagonal plane and the large longitudinal effective mass along the c axis. For the valence band, both heavy-hole and light-hole effective masses are anisotropic at the Γ point. The in-plane electron effective mass also becomes anisotropic under uniaxial tensile strain. The strain response of the heavy-hole mass is opposite to the light hole.

  17. Photonic band structure

    Energy Technology Data Exchange (ETDEWEB)

    Yablonovitch, E. [Univ. of California, Los Angeles, CA (United States)


    We learned how to create 3-dimensionally periodic dielectric structures which are to photon waves, as semiconductor crystals are to electron waves. That is, these photonic crystals have a photonic bandgap, a band of frequencies in which electromagnetic waves are forbidden, irrespective of propagation direction in space. Photonic bandgaps provide for spontaneous emission inhibition and allow for a new class of electromagnetic micro-cavities. If the perfect 3-dimensional periodicity is broken by a local defect, then local electromagnetic modes can occur within the forbidden bandgap. The addition of extra dielectric material locally, inside the photonic crystal, produces {open_quotes}donor{close_quotes} modes. Conversely, the local removal of dielectric material from the photonic crystal produces {open_quotes}acceptor{close_quotes} modes. Therefore, it will now be possible to make high-Q electromagnetic cavities of volume {approx_lt}1 cubic wavelength, for short wavelengths at which metallic cavities are useless. These new dielectric micro-resonators can cover the range all the way from millimeter waves, down to ultraviolet wavelengths.

  18. Report from the banding lab (United States)

    Tautin, J.


    Mr. Tautin reported on the seemingly everchanging structure of biological science units within the Interior Department. Current Congressional proposals would either change the name of the Bird Banding Lab's parent agency or make it part of the Geological Survey. The current Congress has not looked favorably on science budgets within the Interior Department, and the Banding Lab's budget is being squeezed ever tighter.

  19. Long Lake banding project, 1965 (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the results of a banding project on Long Lake in 1965. The dates at the banding site were July 27th through August 8th. As in the past, the...

  20. The Moral Ends of Band (United States)

    Allsup, Randall Everett


    This article provides a theoretical framework through which to reimagine and revitalize contemporary music education practices, using the large ensemble paradigm called "band" as the primary unit of analysis. Literature suggests that band places too much emphasis on teacher control and external measures of validation. Critics propose replacing…

  1. Gate-first integration of tunable work function metal gates of different thicknesses into high-k metal gates CMOS FinFETs for multi- VTh engineering

    KAUST Repository

    Hussain, Muhammad Mustafa


    Gate-first integration of tunable work function metal gates of different thicknesses (320 nm) into high-k/metal gates CMOS FinFETs was demonstrated to achieve multiple threshold voltages (VTh) for 32-nm technology and beyond logic, memory, input/output, and system-on-a-chip applications. The fabricated devices showed excellent short-channel effect immunity (drain-induced barrier lowering ∼ 40 mV/V), nearly symmetric VTh, low T inv(∼ 1.4 nm), and high Ion(∼780μAμm) for N/PMOS without any intentional strain enhancement. © 2006 IEEE.

  2. Band-notched ultrawide band antenna loaded with ferrite slab (United States)

    Wang, Hao; Zong, Weihua; Sun, Nian X.; Lin, Hwaider; Li, Shandong


    In this paper, a novel technique to design a band-notched UWB antenna by using Yttrium Iron Garnet (YIG) ferrite is proposed. A printed slot UWB antenna with size of 21mm×26 mm×0.8 mm is adopted as a basic antenna. A piece of ferrite slab with size of 5 mm×10 mm×2 mm is attached on the feeding layer of the antenna to achieve band-notched characteristics. The measured -10 dB bandwidth of the antenna without ferrite slab is 2.91-10.98 GHz. With loading of ferrite slab, the bandwidth turns to 2.73-5.12 and 5.87-10.78 GHz. A band notch of 5.12- 5.87 GHz is achieved to filter WLAN 5 GHz (5.15-5.825 GHz) band. The proposed technique has virtue of easy fabrication and keeping antenna miniaturization.

  3. Multi-quasiparticle isomers and rotational bands in sup 1 sup 8 sup 1 Re

    CERN Document Server

    Pearson, C J; Purry, C S; Dracoulis, G D; Bayer, S; Byrne, A P; Kibedi, T; Kondev, F G


    High-spin states in sup 1 sup 8 sup 1 Re have been populated using the sup 1 sup 7 sup 6 Yb( sup 1 sup 1 B, 6n) reaction and their decays studied using the CAESAR gamma -ray spectrometer. Thirteen bands of rotational states have been observed based on 1-, 3- and 5-quasiparticle structures, including two new 5-quasiparticle isomers, with half-lives of 1.2 mu s and 22 ns. Angular correlation and distribution coefficients were obtained and gamma -ray intensity ratios were used to extract |g sub K -g sub R |/Q sub 0 ratios. Three K -forbidden decays were observed and their reduced hindrance factors were obtained and found to be consistent with known systematic behaviour. Band crossings were observed between 1- and 3-quasiparticle bands. These rotation-aligned 3-quasiparticle bands appear to have high K , and are identified as t -bands. Band mixing calculations support the assigned K -values. A unique degeneracy was observed for two I suppi=23/2 sup - states at 1883 keV.

  4. Conductive Bands Diminish Electrostatic Discharges (United States)

    Leung, Philip L.; Whittlesey, Albert


    Electrostatic discharges on surfaces covered with electrically insulating paints reduced by connecting edges of painted surfaces to electrical grounds with band of conductive material. Prevents charge build up on paint which eventually arcs to conductive surface, damaging structures and equipment.

  5. Intensity formulas for triplet bands (United States)

    Budo, A.


    Previous work in this area is surveyed and the mathematics involved in determining the quantitative intensity measurements in triplet bands is presented. Explicit expressions for the intensity distribution in the branches of the 3 Sigma-3 Pi and 1 Sigma-3Pi bands valid for all values of the coupling constant Y of the 3 Pi terms are given. The intensity distribution calculated according to the formulas given is compared with measurements of PH, 3 Pi-3 Sigma. Good quantitative agreement is obtained.

  6. Single-Band and Dual-Band Infrared Detectors (United States)

    Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor); Soibel, Alexander (Inventor); Nguyen, Jean (Inventor); Khoshakhlagh, Arezou (Inventor)


    Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.

  7. Adhesives for fixed orthodontic bands. (United States)

    Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A


    Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

  8. Voltage and oxide thickness dependent tunneling current density and tunnel resistivity model: Application to high-k material HfO2 based MOS devices (United States)

    Maity, N. P.; Maity, Reshmi; Baishya, Srimanta


    In this paper presents a straightforward efficient investigation of tunneling current density for ultra thin oxide layer based metal-oxide-semiconductor (MOS) devices to realization the gate current as a function of applied potential and oxide thickness. Solutions to the Schrödinger's wave equation are evolved for the different potential energy regions of the MOS device considering appropriate effective mass for each region. For finding approximate mathematical solutions to linear differential equations using spatially changeable coefficients the Wentzel-Kramers-Brillouin (WKB) approximation technique is considered. A p-substrate based n-channel MOS device has been analyzed consisting of SiO2 material as the oxide dielectric along with high-k material HfO2. The tunnel resistivity is correspondingly assessed employing this tunneling current density model. Synopsys Technology Computer Aided Design (TCAD) tool results are employed to validate the analytical model. Tremendous agreements among the results are observed.

  9. Extremely scaled high-k/In₀.₅₃Ga₀.₄₇As gate stacks with low leakage and low interface trap densities

    Energy Technology Data Exchange (ETDEWEB)

    Chobpattana, Varistha; Mikheev, Evgeny; Zhang, Jack Y.; Mates, Thomas E.; Stemmer, Susanne [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)


    Highly scaled gate dielectric stacks with low leakage and low interface trap densities are required for complementary metal-oxide-semiconductor technology with III-V semiconductor channels. Here, we show that a novel pre-deposition technique, consisting of alternating cycles of nitrogen plasma and tetrakis(dimethylamino)titanium, allows for HfO₂ and ZrO₂ gate stacks with extremely high accumulation capacitance densities of more than 5 μF/cm₂ at 1 MHz, low leakage current, low frequency dispersion, and low midgap interface trap densities (10¹²cm⁻²eV⁻¹range). Using x-ray photoelectron spectroscopy, we show that the interface contains TiO₂ and small quantities of In₂O₃, but no detectable Ga- or As-oxides, or As-As bonding. The results allow for insights into the microscopic mechanisms that control leakage and frequency dispersion in high-k/III-V gate stacks.

  10. Remote N2 plasma treatment to deposit ultrathin high-k dielectric as tunneling contact layer for single-layer MoS2 MOSFET (United States)

    Qian, Qingkai; Zhang, Zhaofu; Hua, Mengyuan; Wei, Jin; Lei, Jiacheng; Chen, Kevin J.


    Remote N2 plasma treatment is explored as a surface functionalization technique to deposit ultrathin high-k dielectric on single-layer MoS2. The ultrathin dielectric is used as a tunneling contact layer, which also serves as an interfacial layer below the gate region for fabricating top-gate MoS2 metal–oxide–semiconductor field-effect transistors (MOSFETs). The fabricated devices exhibited small hysteresis and mobility as high as 14 cm2·V‑1·s‑1. The contact resistance was significantly reduced, which resulted in the increase of drain current from 20 to 56 µA/µm. The contact resistance reduction can be attributed to the alleviated metal–MoS2 interface reaction and the preserved conductivity of MoS2 below the source/drain metal contact.

  11. Flexible, Low-Power Thin-Film Transistors Made of Vapor-Phase Synthesized High-k, Ultrathin Polymer Gate Dielectrics. (United States)

    Choi, Junhwan; Joo, Munkyu; Seong, Hyejeong; Pak, Kwanyong; Park, Hongkeun; Park, Chan Woo; Im, Sung Gap


    A series of high-k, ultrathin copolymer gate dielectrics were synthesized from 2-cyanoethyl acrylate (CEA) and di(ethylene glycol) divinyl ether (DEGDVE) monomers by a free radical polymerization via a one-step, vapor-phase, initiated chemical vapor deposition (iCVD) method. The chemical composition of the copolymers was systematically optimized by tuning the input ratio of the vaporized CEA and DEGDVE monomers to achieve a high dielectric constant (k) as well as excellent dielectric strength. Interestingly, DEGDVE was nonhomopolymerizable but it was able to form a copolymer with other kinds of monomers. Utilizing this interesting property of the DEGDVE cross-linker, the dielectric constant of the copolymer film could be maximized with minimum incorporation of the cross-linker moiety. To our knowledge, this is the first report on the synthesis of a cyanide-containing polymer in the vapor phase, where a high-purity polymer film with a maximized dielectric constant was achieved. The dielectric film with the optimized composition showed a dielectric constant greater than 6 and extremely low leakage current densities (thin-film transistors (OTFTs) and oxide TFTs were fabricated, which showed hysteresis-free transfer characteristics with an operating voltage of less than 3 V. Furthermore, the flexible OTFTs retained their low gate leakage current and ideal TFT characteristics even under 2% applied tensile strain, which makes them some of the most flexible OTFTs reported to date. We believe that these ultrathin, high-k organic dielectric films with excellent mechanical flexibility will play a crucial role in future soft electronics.

  12. The influence of carbon doping on the performance of Gd{sub 2}O{sub 3} as high-k gate dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Shekhter, P.; Yehezkel, S.; Shriki, A.; Eizenberg, M. [Department of Materials Science and Engineering, Technion–Israel Institute of Technology, Haifa 32000 (Israel); Chaudhuri, A. R.; Osten, H. J. [Institute of Electronic Materials and Devices, Leibniz University of Hannover, Schneiderberg 32, 30167 Hannover (Germany); Laha, A. [Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai (India)


    One of the approaches for overcoming the issue of leakage current in modern metal-oxide-semiconductor devices is utilizing the high dielectric constants of lanthanide based oxides. We investigated the effect of carbon doping directly into Gd{sub 2}O{sub 3} layers on the performance of such devices. It was found that the amount of carbon introduced into the dielectric is above the solubility limit; carbon atoms enrich the oxide-semiconductor interface and cause a significant shift in the flat band voltage of the stack. Although the carbon atoms slightly degrade this interface, this method has a potential for tuning the flat band voltage of such structures.

  13. X-Band PLL Synthesizer

    Directory of Open Access Journals (Sweden)

    P. Kutin


    Full Text Available This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal from the frequency doubler is filtered by a band-pass filter and finally amplified by a single stage amplifier.

  14. Engineering of optical and electronic band gaps in transition metal dichalcogenide monolayers through external dielectric screening (United States)

    Borghardt, Sven; Tu, Jhih-Sian; Winkler, Florian; Schubert, Jürgen; Zander, Willi; Leosson, Kristjan; Kardynał, Beata E.


    Heterojunctions are the backbone of established semiconductor technology. The highly desirable reliable creation of dielectrically defined heterojunctions in transition metal dichalcogenide monolayers (TMD-MLs) requires an in-depth understanding of dielectric screening effects induced by the ML's environment. Here we report on the modulations of excitonic transitions in TMD-MLs through the effect of dielectric environments including low-k and high-k dielectric materials. We present absolute tuning ranges as large as 37 meV for the optical band gaps of WSe2 and MoSe2 MLs and relative tuning ranges on the order of 15% for the binding energies of charged excitons. Additionally, we measure relative changes of 30% in the energy splittings of exciton Rydberg states of WSe2. The findings enable us to estimate changes in the exciton binding energies and the electronic band gaps of the studied materials.

  15. Linear methods in band theory

    DEFF Research Database (Denmark)

    Andersen, O. Krogh


    -independent augmented plane waves (APW) and muffin-tin orbitals (MTO), respectively. The secular equations are therefore eigenvalue equations, linear in energy. The trial functions are defined with respect to a muffin-tin (MT) potential and the energy bands depend on the potential in the spheres through potential...

  16. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    band characteristics. The controlling of the electromagnetic radiation was possible by employing two frequency selective switches. Use of such MBG structures for the non-destructive evaluation of material properties was demonstrated by replacing the substrate with silicon. Pramana – J. Phys., Vol. 70, No. 4, April 2008. 745 ...

  17. Metaphyseal bands in osteogenesis imperfecta

    Directory of Open Access Journals (Sweden)

    Suresh S


    Full Text Available An increasing number of patients with osteogenesis imperfecta are undergoing pamidronate therapy to prevent the incidence of fragility fractures. The authors herein report a child aged 3 years who received five cycles of pamidronate, resulting in metaphyseal bands, known as "zebra lines."

  18. Symptomatic mesodiverticular bands in children

    African Journals Online (AJOL)

    Pediatr Surg 14:21–23 c 2018 Annals of Pediatric. Surgery. Annals of Pediatric Surgery 2018, 14:21–23. Keywords: internal hernia, laparoscopy, Meckel's diverticulum, mesodiverticular band, small bowel obstruction. aS.C. di Clinica Chirurgica Pediatrica, University of Perugia, S. Maria della. Misericordia Hospital, Perugia ...


    African Journals Online (AJOL)

    answers or solutions, religious people need charismatic persons to interpret the divine mind. Hence, contemporary ..... if the person is found worthy, the person is sent back to his/her branch as a recognized member of the band of ... Prophetic work in the ACPPB makes it a prayer house with a difference. Apart from Madam.

  20. Non-Hermiticity Induced Flat Band


    Ramezani, Hamidreza


    We demonstrate the emergence of an entire flat band embedded in dispersive bands at the exceptional point of a PT symmetric photonic lattice. For this to occur, the gain and loss parameter effectively alters the size of the partial flat band windows and band gap of the photonic lattice simultaneously. The mode associated with the entire flat band is robust against changes in the system size and survives even at the edge of the lattice. Our proposal offers a route for controllable localization...

  1. Compact Dual Band Antenna Design for Ku / Ka Band Applications

    Directory of Open Access Journals (Sweden)

    A. Kandwal


    Full Text Available This communication proposes a compact 16 GHz / 30 GHz dual band antenna design for Ku / Ka band applications. The antenna consists of two layers with lower layer having the fed patch and the upper layer having non-periodic element array. The antenna has been designed to operate at two different frequencies with compact dimensions of (8mm x 8mm using Rogers RT 5880. The compact size of this proposed antenna also makes it suitable for integration with the microwave and millimeter wave circuits. The proposed antenna provides high radiation efficiency and a peak gain of about 8 dB at the resonant frequencies with reduced side lobe levels.

  2. High-k materials in the electrolyte/insulator/silicon configuration. Characterization and application in bio-electronics; Hoch-k-Materialien in der Elektrolyt/Isolator/Silizium-Konfiguration. Charakterisierung und Anwendung in der Bioelektronik

    Energy Technology Data Exchange (ETDEWEB)

    Wallrapp, F.


    In order to elicit action potentials in nerve cells adhered on electrodes, a certain current is required across the electrode. Electrochemical reactions may cause damage to cells and electrodes. This is evaded by using silicon electrodes which are insulated by a dielectric. In doing so, only capacitive current is flowing, and electrochemical are avoided. The aim of this work was to fabricate novel stimulation chips exhibiting an enhanced capacitance which render new biological applications possible. These chips were to be characterized and used for the stimulation of cells. The formerly used dielectric SiO{sub 2} was replaced by HfO{sub 2} and TiO{sub 2}, with both of them featuring a higher dielectric constant. They were deposited on the silicon substrate by ALD (atomic layer deposition). The chips were characterized in the electrolyte/insulator/semiconductor (EIS) configuration. Owing to the low leakage current of the EIS configuration, the characterization of the high-k materials was possible in more detail as compared to using a metallic top contact (MIS configuration). The voltage-dependent capacitances of the HfO{sub 2} films could be interpreted by means of a common metal/SiO{sub 2}/silicon system. In contrast, the TiO{sub 2} films exhibited interesting properties which could only be rationalized with the help of numerical calculations assuming free electrons in the TiO{sub 2}. The low-lying conduction band of TiO{sub 2} caused accumulation of electrons within the TiO{sub 2} for certain voltages, which led to an enhanced capacitance. The effects of high voltages, frequency, film thickness and interlayer composition were examined and brought into compliance with the model. The novel TiO{sub 2} stimulation devices featured a five-fold capacitance increase as compared to former SiO{sub 2} chips. Using them, two fundamental stimulation mechanisms were induced in HEK293 cells expressing the recombinant potassium channel Kv1.3: Opening of ion channels and

  3. Electrical properties of nano-resistors made from the Zr-doped HfO2 high-k dielectric film (United States)

    Zhang, Shumao; Kuo, Yue


    Electrical properties of nano-sized resistors made from the breakdown of the metal-oxide-semiconductor capacitor composed of the amorphous high-k gate dielectric have been investigated under different stress voltages and temperatures. The effective resistance of nano-resistors in the device was estimated from the I–V curve in the high voltage range. It decreased with the increase of the number of resistors. The resistance showed complicated temperature dependence, i.e. it neither behaves like a conductor nor a semiconductor. In the low voltage operation range, the charge transfer was controlled by the Schottky barrier at the nano-resistor/Si interface. The barrier height decreased with the increase of stress voltage, which was probably caused by the change of the nano-resistor composition. Separately, it was observed that the barrier height was dependent on the temperature, which was probably due to the dynamic nano-resistor formation process and the inhomogeneous barrier height distribution. The unique electrical characteristics of this new type of nano-resistors are important for many electronic and optoelectronic applications.

  4. The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins

    Directory of Open Access Journals (Sweden)

    Sommer Carlos A.


    Full Text Available The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and calc-alkaline to shoshonitic and ended with a silica-saturated sodic alkaline magmatism, and its evolution were developed during at least 60 Ma. The compositional variation and evolution of post-collisional magmatism in southern Brazil are interpreted as the result mainly of melting of a heterogeneous mantle source, which includes garnet-phlogopite-bearing peridotites, veined-peridotites with abundant hydrated phases, such as amphibole, apatite and phlogopite, and eventually with the addition of an asthenospheric component. The subduction-related metasomatic character of post-collisional magmatism mantle sources in southern Brazil is put in evidence by Nb-negative anomalies and isotope features typical of EM1 sources.

  5. GaN-Based High-k Praseodymium Oxide Gate MISFETs with P2S5/(NH42SX + UV Interface Treatment Technology

    Directory of Open Access Journals (Sweden)

    Chao-Wei Lin


    Full Text Available This study examines the praseodymium-oxide- (Pr2O3- passivated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs with high dielectric constant in which the AlGaN Schottky layers are treated with P2S5/(NH42SX + ultraviolet (UV illumination. An electron-beam evaporated Pr2O3 insulator is used instead of traditional plasma-assisted chemical vapor deposition (PECVD, in order to prevent plasma-induced damage to the AlGaN. In this work, the HEMTs are pretreated with P2S5/(NH42SX solution and UV illumination before the gate insulator (Pr2O3 is deposited. Since stable sulfur that is bound to the Ga species can be obtained easily and surface oxygen atoms are reduced by the P2S5/(NH42SX pretreatment, the lowest leakage current is observed in MIS-HEMT. Additionally, a low flicker noise and a low surface roughness (0.38 nm are also obtained using this novel process, which demonstrates its ability to reduce the surface states. Low gate leakage current Pr2O3 and high-k AlGaN/GaN MIS-HEMTs, with P2S5/(NH42SX + UV illumination treatment, are suited to low-noise applications, because of the electron-beam-evaporated insulator and the new chemical pretreatment.

  6. The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins. (United States)

    Sommer, Carlos A; Lima, Evandro F; Nardi, Lauro V S; Liz, Joaquim D; Waichel, Breno L


    The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and calc-alkaline to shoshonitic and ended with a silica-saturated sodic alkaline magmatism, and its evolution were developed during at least 60 Ma. The compositional variation and evolution of post-collisional magmatism in southern Brazil are interpreted as the result mainly of melting of a heterogeneous mantle source, which includes garnet-phlogopite-bearing peridotites, veined-peridotites with abundant hydrated phases, such as amphibole, apatite and phlogopite, and eventually with the addition of an asthenospheric component. The subduction-related metasomatic character of post-collisional magmatism mantle sources in southern Brazil is put in evidence by Nb-negative anomalies and isotope features typical of EM1 sources.

  7. Transmission Enhancement of High-$k$ Waves through Metal-InGaAsP Multilayers Calculated via Scattering Matrix Method with Semi-Classical Optical Gain

    CERN Document Server

    Smalley, Joseph S T; Shahin, Shiva; Kanté, Boubacar; Fainman, Yeshaiahu


    We analyze the steady-state transmission of high-momentum (high-$k$) electromagnetic waves through metal-semiconductor multilayer systems with loss and gain in the near-infrared (NIR). Using a semi-classical optical gain model in conjunction with the scattering matrix method (SMM), we study indium gallium arsenide phosphide (InGaAsP) quantum wells as the active semiconductor, in combination with the metals, aluminum-doped zinc oxide (AZO) and silver (Ag). Under moderate external pumping levels, we find that NIR transmission through Ag/InGaAsP systems may be enhanced by several orders of magnitude relative to the unpumped case, over a large angular and frequency bandwidth. Conversely, transmission enhancement through AZO/InGaAsP systems is orders of magnitude smaller, and has a strong frequency dependence. We discuss the relative importance of Purcell enhancement on our results and validate analytical calculations based on the SMM with numerical finite-difference time domain simulations.

  8. Effects of Gate Stack Structural and Process Defectivity on High-k Dielectric Dependence of NBTI Reliability in 32 nm Technology Node PMOSFETs

    Directory of Open Access Journals (Sweden)

    H. Hussin


    Full Text Available We present a simulation study on negative bias temperature instability (NBTI induced hole trapping in E′ center defects, which leads to depassivation of interface trap precursor in different geometrical structures of high-k PMOSFET gate stacks using the two-stage NBTI model. The resulting degradation is characterized based on the time evolution of the interface and hole trap densities, as well as the resulting threshold voltage shift. By varying the physical thicknesses of the interface silicon dioxide (SiO2 and hafnium oxide (HfO2 layers, we investigate how the variation in thickness affects hole trapping/detrapping at different stress temperatures. The results suggest that the degradations are highly dependent on the physical gate stack parameters for a given stress voltage and temperature. The degradation is more pronounced by 5% when the thicknesses of HfO2 are increased but is reduced by 11% when the SiO2 interface layer thickness is increased during lower stress voltage. However, at higher stress voltage, greater degradation is observed for a thicker SiO2 interface layer. In addition, the existence of different stress temperatures at which the degradation behavior differs implies that the hole trapping/detrapping event is thermally activated.

  9. High-performance III-V MOSFET with nano-stacked high-k gate dielectric and 3D fin-shaped structure. (United States)

    Chen, Szu-Hung; Liao, Wen-Shiang; Yang, Hsin-Chia; Wang, Shea-Jue; Liaw, Yue-Gie; Wang, Hao; Gu, Haoshuang; Wang, Mu-Chun


    A three-dimensional (3D) fin-shaped field-effect transistor structure based on III-V metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication has been demonstrated using a submicron GaAs fin as the high-mobility channel. The fin-shaped channel has a thickness-to-width ratio (TFin/WFin) equal to 1. The nano-stacked high-k Al2O3 dielectric was adopted as a gate insulator in forming a metal-oxide-semiconductor structure to suppress gate leakage. The 3D III-V MOSFET exhibits outstanding gate controllability and shows a high Ion/Ioff ratio > 105 and a low subthreshold swing of 80 mV/decade. Compared to a conventional Schottky gate metal-semiconductor field-effect transistor or planar III-V MOSFETs, the III-V MOSFET in this work exhibits a significant performance improvement and is promising for future development of high-performance n-channel devices based on III-V materials.

  10. MIRA: Dual wavelength band instrument

    Directory of Open Access Journals (Sweden)

    Robert Georgii


    Full Text Available MIRA is a dual wavelength band instrument operated by Technische Universität München TUM, which provides neutrons over a wide range of wavelengths 3.5 Å < λ < 20 Å combining the two beam ports of MIRA-1 and MIRA-2. The instrument´s setup is modular and allows for various different cold neutron experiments such as diffraction, spectroscopy or reflectometry.

  11. [Gastric band erosion: Alternative management]. (United States)

    Echaverry-Navarrete, Denis José; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Cabrera-Jardines, Ricardo; Mondragón-Pinzón, Erwin Eduardo; Castillo-González, Federico Armando


    Obesity is a public health problem, for which the prevalence has increased worldwide at an alarming rate, affecting 1.7 billion people in the world. To describe the technique employed in incomplete penetration of gastric band where endoscopic management and/or primary closure is not feasible. Laparoscopic removal of gastric band was performed in five patients with incomplete penetrance using Foley catheterization in the perforation site that could lead to the development of a gastro-cutaneous fistula. The cases presented include a leak that required surgical lavage with satisfactory outcome, and one patient developed stenosis 3 years after surgical management, which was resolved endoscopically. In all cases, the penetration site closed spontaneously. Gastric band erosion has been reported in 3.4% of cases. The reason for inserting a catheter is to create a controlled gastro-cutaneous fistula, allowing spontaneous closure. Various techniques have been described: the totally endoscopic, hybrid techniques (endoscopic/laparoscopic) and completely laparoscopic. A technique is described here that is useful and successful in cases where the above-described treatments are not viable. Copyright © 2015. Published by Masson Doyma México S.A.

  12. Influence of Design and Process Parameters of 32-nm Advanced-Process High- k p-MOSFETs on Negative-Bias Temperature Instability and Study of Defects (United States)

    Alimin, A. F. Muhammad; Radzi, A. A. Mohd; Sazali, N. A. F.; Hatta, S. F. Wan Muhamad; Soin, N.; Hussin, H.


    Negative-bias temperature instability (NBTI) has become a prominent factor limiting scaling of complementary metal-oxide-semiconductor technology. This work presents a comprehensive simulation study on the effects of critical design parameters of 32-nm advanced-process high- k p-channel metal-oxide-semiconductor field-effect transistors on NBTI. The NBTI mechanism and defects were explored for various geometric and process design parameters over a wide range of values. The NBTI simulation method applied in this work follows the on-the-fly method to capture the mechanisms of fast and slow traps. This work illustrates the dependence of the threshold voltage ( V th) degradation on the stress oxide field and stress temperature as well as investigation of the Arrhenius plot for the devices. The temperature insensitivity during short stress time of 1 ms indicates absence of generated defects and presence of preexisting defects. It is also observed that significant defects are generated in the gate stack subsequent to NBTI. The slope obtained from the V th degradation analysis at 1 ks and 375°C shows that changing the SiO2 interfacial layer thickness affects the V th degradation by 96.16% more than changing the HfO2 thickness and by 80.67% more than changing the metal gate thickness. It is also found that the NBTI effect depends on process design considerations, specifically the boron concentration in the highly doped drain, the metal gate work function, and the halo doping concentration; it was observed that higher boron dose and high metal work function may lead to higher V th degradation. However, the halo doping concentration in the advanced 32-nm structure has an insignificant effect on NBTI.

  13. Trap state passivation improved hot-carrier instability by zirconium-doping in hafnium oxide in a nanoscale n-metal-oxide semiconductor-field effect transistors with high-k/metal gate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hsi-Wen; Tsai, Jyun-Yu; Liu, Kuan-Ju; Lu, Ying-Hsin [Department of Physics, National Sun Yat-sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Chang, Ting-Chang, E-mail: [Department of Physics, National Sun Yat-sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Tainan 701, Taiwan (China); Chen, Ching-En; Tseng, Tseung-Yuen [Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Lin, Chien-Yu [Department of Photonics, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Cheng, Osbert; Huang, Cheng-Tung; Ye, Yi-Han [Device Department, United Microelectronics Corporation, Tainan Science Park, Tainan 701, Taiwan (China)


    This work investigates the effect on hot carrier degradation (HCD) of doping zirconium into the hafnium oxide high-k layer in the nanoscale high-k/metal gate n-channel metal-oxide-semiconductor field-effect-transistors. Previous n-metal-oxide semiconductor-field effect transistor studies demonstrated that zirconium-doped hafnium oxide reduces charge trapping and improves positive bias temperature instability. In this work, a clear reduction in HCD is observed with zirconium-doped hafnium oxide because channel hot electron (CHE) trapping in pre-existing high-k bulk defects is the main degradation mechanism. However, this reduced HCD became ineffective at ultra-low temperature, since CHE traps in the deeper bulk defects at ultra-low temperature, while zirconium-doping only passivates shallow bulk defects.

  14. Prenatal diagnosis of amniotic band syndrome

    Directory of Open Access Journals (Sweden)

    Laxmi Devi Padmanabhan


    Full Text Available Amniotic band can cause a broad spectrum of anomalies ranging from simple band constrictions to major craniofacial and visceral defects. It can cause significant neonatal morbidity. Accurate diagnosis will help in the management of the present pregnancy and in counseling with regard to future pregnancies. Here we report three cases of amniotic band syndrome detected in the prenatal period.

  15. High-energy band structure of gold

    DEFF Research Database (Denmark)

    Christensen, N. Egede


    The band structure of gold for energies far above the Fermi level has been calculated using the relativistic augmented-plane-wave method. The calculated f-band edge (Γ6-) lies 15.6 eV above the Fermi level is agreement with recent photoemission work. The band model is applied to interpret...


    DEFF Research Database (Denmark)


    An optical fibre having a periodicidal cladding structure provididing a photonic band gap structure with superior qualities. The periodical structure being one wherein high index areas are defined and wherein these are separated using a number of methods. One such method is the introduction...... of additional low index elements, another method is providing elongated elements deformed in relation to a circular cross section. Also described is a cladding structure comprising elongated elements of a material having an index of refraction higher than that of the material adjacent thereto. Using...

  17. The geometric structure of the Landau bands

    CERN Document Server

    Brüning, J; Geyler, V


    We have proposed a semiclassical explanation of the geometric structure of the spectrum for the two-dimensional Landau Hamiltonian with a two-periodic electric field without any additional assumptions on the potential. Applying an iterative averaging procedure we approximately, with any degree of accuracy, separate variables and describe a given Landau band as the spectrum of a Harper-like operator. The quantized Reeb graph for such an operator is used to obtain the following structure of the Landau band: localized states on the band wings and extended states near the middle of the band. Our approach also shows that different Landau bands have different geometric structure.

  18. Ta{sub 2}O{sub 5}-based high-K dielectric thin films from solution processed at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Frunză, Raluca C., E-mail: [Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana (Slovenia); Kmet, Brigita [Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Jankovec, Marko; Topič, Marko [Faculty of Electrical Engineering, University of Ljubljana, Tržaška cesta 25, 1000 Ljubljana (Slovenia); Malič, Barbara [Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia)


    Highlights: • Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} (Ta:Al:Si = 8:1:1 atomic ratio) and Ta{sub 2}O{sub 5} films were processed from solutions. • The XRD-amorphous films, heated at or below 400 °C, are smooth (RMS < 0.5 nm). • The dielectric permittivity of the single- and mixed-oxide films heated at 400 °C is 27 and 22, respectively. • The current–voltage characteristics of the mixed-oxide films reveal the Poole–Frenkel behaviour. - Abstract: Ta{sub 2}O{sub 5}-based thin films were prepared by chemical solution deposition at temperatures not exceeding 400 °C. The aim of the work was to investigate the properties of high-K dielectric films of the ternary composition Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} with the Ta:Al:Si = 8:1:1 atomic ratio. Pure Ta{sub 2}O{sub 5} samples were also prepared. All thin films were amorphous, and had smooth and flat surfaces with the average roughness of below 0.5 nm. The mixed oxide samples heated between 300 °C and 400 °C showed little difference in the dielectric permittivity with the values ranging from about 19 to 22. The Ta{sub 2}O{sub 5} film heated at 400 °C exhibited the highest permittivity of about 27. The current–voltage measurements revealed considerably improved characteristics of the Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} samples within the investigated heating temperature range, with a significant overall decrease of the leakage currents in contrast to that of the pure Ta{sub 2}O{sub 5} thin films.

  19. A Novel Ku-Band/Ka-Band and Ka-Band/E-Band Multimode Waveguide Couplers for Power Measurement of Traveling-Wave Tube Amplifier Harmonic Frequencies (United States)

    Wintucky, Edwin G.; Simons, Rainee N.


    This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler, fabricated from two dissimilar frequency band waveguides, is capable of isolating power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT) amplifier. Test results from proof-of-concept demonstrations are presented for a Ku-band/Ka-band MDC and a Ka-band/E-band MDC. In addition to power measurements at harmonic frequencies, a potential application of the MDC is in the design of a satellite borne beacon source for atmospheric propagation studies at millimeter-wave (mm-wave) frequencies (Ka-band and E-band).

  20. Chiral flat bands: Existence, engineering, and stability (United States)

    Ramachandran, Ajith; Andreanov, Alexei; Flach, Sergej


    We study flat bands in bipartite tight-binding networks with discrete translational invariance. Chiral flat bands with chiral symmetry eigenenergy E =0 and host compact localized eigenstates for finite range hopping. For a bipartite network with a majority sublattice chiral flat bands emerge. We present a simple generating principle of chiral flat-band networks and as a showcase add to the previously observed cases a number of new potentially realizable chiral flat bands in various lattice dimensions. Chiral symmetry respecting network perturbations—including disorder and synthetic magnetic fields—preserve both the flat band and the modified compact localized states. Chiral flat bands are spectrally protected by gaps and pseudogaps in the presence of disorder due to Griffiths effects.

  1. Giemsa C-banding of Barley Chromosomes. I: Banding Pattern Polymorphism

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib


    Twenty barley (Hordeum vulgare) lines studied had a common basic chromosome banding pattern. Most bands ranged from medium to very small in size. The most conspicuous banding occurred at or near the centromeres, in the proximal, intercalary parts of most chromosome arms and beside the secondary c...... 7. Seventeen differently banded karyotypes were found. Some banding pattern polymorphisms can be used in cytological and cytogenetic studies....

  2. Rat gastric banding model for bariatric surgery. (United States)

    Kanno, Hitoshi; Kiyama, Teruo; Fujita, Itsuo; Kato, Shunji; Yoshiyuki, Toshiro; Tajiri, Takashi


    Adjustable gastric banding is a surgical approach to weight reduction. In this study we created a gastric banding model in rats to better understand the mechanism of body weight loss. Male Sprague-Dawley rats weighing 260 to 280 g were subjected to gastric banding (band group) (n=8) or to a sham operation (control group) (n=8). Body weights were monitored for 14 days, and daily food and water intake and nitrogen balance were monitored for 7 days. Two rats in the band group died of malnutrition due to gastric stomal stenosis and obstruction caused by the gastric banding. Body weight gain during the 14 days after the operation was less in the band group than in the control group (pwater intake during the 7 days after the operation was significantly less in the band group than in the control group (pbalance was significantly less in the band group than in the control group (p<0.01). Gastric banding decreased the body weight gain of rats by decreasing the amount of food intake because of the creation of a small gastric pouch.

  3. Characterization of chromosomal rearrangements using multicolor-banding (MCB/m-band). (United States)

    Liehr, Thomas; Weise, Anja; Hinreiner, Sophie; Mkrtchyan, Hasmik; Mrasek, Kristin; Kosyakova, Nadezda


    Molecular cytogenetics and especially fluorescence in situ hybridization (FISH) banding approaches are nowadays standard for the exact characterization of simple, complex, and cryptic chromosomal aberrations within the human genome. FISH-banding techniques are any kind of FISH techniques, which provide the possibility to characterize simultaneously several chromosomal subregions smaller than a chromosome arm. FISH banding methods fitting that definition may have quite different characteristics, but share the ability to produce a DNA-specific chromosomal banding. While the standard techniques such as G-bands by Trypsin using Giemsa banding lead to a protein-related black and white banding pattern, FISH-banding techniques are DNA-specific, more colorful, and thus, more informative. At present, the most frequently applied FISH banding technique is the multicolor banding (MCB/m-band) approach. MCB/m-band is based on region-specific microdissection libraries, producing changing fluorescence intensity ratios along the chromosomes. Here we describe the FISH-banding technique MCB/m-band and illustrate how to apply it for characterization of chromosomal breakpoints with a minimal number of FISH experiments.

  4. Multi-band slow light metamaterial. (United States)

    Zhu, Lei; Meng, Fan-Yi; Fu, Jia-Hui; Wu, Qun; Hua, Jun


    In this paper, a multi-band slow light metamaterial is presented and investigated. The metamaterial unit cell is composed of three cut wires of different sizes and parallel to each other. Two transparency windows induced by two-two overlaps of absorption bands of three cut wires are observed. The multi-band transmission characteristics and the slow light properties of metamaterial are verified by numerical simulation, which is in a good agreement with theoretical predictions. The impacts of structure parameters on transparency windows are also investigated. Simulation results show the spectral properties can be tuned by adjusting structure parameters of metamaterial. The equivalent circuit model and the synthesis method of the multi-band slow light metamaterial are presented. It is seen from simulation results that the synthesis method accurately predicts the center frequency of the multi-band metamaterial, which opens a door to a quick and accurate construction for multi-band slow light metamaterial.

  5. Topology of two-band superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Y., E-mail: y.tanaka@aist.go.j [National Institute of Advanced Industrial Science and Technology (AIST), AIST-Tsukuba Central-2-32918, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Iyo, A. [National Institute of Advanced Industrial Science and Technology (AIST), AIST-Tsukuba Central-2-32918, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Tokiwa, K.; Watanabe, T. [Department of Applied Electronics, Faculty of Industrial Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Crisan, A. [National Institute for Materials Physics, P.O. Box MG-7, Bucharest 077125 (Romania); Department of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Sundaresan, A. [Chemistry and Physics of Materials Unit (CPMU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bangalore 560 064 (India); Terada, N. [Department of Electrical and Electronics Engineering, Faculty of of Engineering, Kagoshima University, 1-21-40 Koromoto, Kagoshima, Kagoshima 890-0065 (Japan)


    Two-band superconductivity has a topology different from that in single-band superconductivity. The topology is not always stabilized in an infinitely homogeneous sample. The morphology, grain shape, and pattern of the device (topology of the superconducting materials) is effective in stabilizing the topology. In this report, we discuss a vortex having a small magnetic flux but a large winding number as one plausible topology in a two-band superconductor.

  6. Fluctuation Diamagnetism in Two-Band Superconductors


    Adachi, Kyosuke; Ikeda, Ryusuke


    Anomalously large fluctuation diamagnetism around the superconducting critical temperature has been recently observed on iron selenide (FeSe) [S. Kasahara et al., unpublished]. This indicates that superconducting fluctuations (SCFs) play a more significant role in FeSe, which supposedly has two-band structure, than in the familiar single-band superconductors. Motivated by the data in FeSe, SCF-induced diamagnetism is examined in a two-band system, on the basis of a phenomenological approach w...

  7. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsen, Rasmus


    the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...... to lighting conditions. Results show that localisation accuracy of facial features is considerably increased using this appearance representation under normal and abnormal lighting and at multiple scales....

  8. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsen, Rasmus


    the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...... to lighting conditions. Results show that the localisation accuracy of facial features is considerably increased using this appearance representation under diffuse and directional lighting and at multiple scales....

  9. Band-limited power flow into enclosures (United States)

    Pope, L. D.; Wilby, J. F.


    Equations for the band-limited power flow to a cavity in the low-frequency regime are derived. The total power to cavity is obtained by summing separate calculations of the power from structural modes resonant in the band and power from structural modes resonant below the band. High-frequency relations compatible with the usual statistical energy analysis and generalized to include other excitations in addition to diffuse fields are also provided.

  10. On Rabi oscillations between Bloch bands


    Plötz, Patrick


    We study Rabi oscillations between the bands of an arbitrary biased superlattice in a tight-binding model. We reduce the problem to an equation of Whittaker--Hill type and, in absence of any known solutions in closed form, discuss different approximations to describe the oscillations between the Bloch bands. We identify regimes of weak and strong inter-band coupling and compare predictions for these Rabi oscillations to numerical results.

  11. A dual band terahertz metamaterial absorber

    Energy Technology Data Exchange (ETDEWEB)

    Tao Hu; Fan Kebin; Zhang Xin [Department of Mechanical Engineering, Boston University, Boston, MA 02215 (United States); Bingham, C M; Shrekenhamer, D; Padilla, W J [Department of Physics, Boston College, Chestnut Hill, MA 02467 (United States); Pilon, D; Strikwerda, A C; Averitt, R D, E-mail: xinz@bu.ed, E-mail: raveritt@physics.bu.ed [Department of Physics, Boston University, Boston, MA 02215 (United States)


    We present the design, fabrication and characterization of a dual band metamaterial absorber which experimentally shows two distinct absorption peaks of 0.85 at 1.4 THz and 0.94 at 3.0 THz. The dual band absorber consists of a dual band electric-field-coupled (ELC) resonator and a metallic ground plane, separated by an 8 {mu}m dielectric spacer. Fine tuning of the two absorption resonances is achieved by individually adjusting each ELC resonator geometry.


    Energy Technology Data Exchange (ETDEWEB)

    Vlieks, Arnold E.; /SLAC


    The development of X-band klystrons at SLAC originated with the idea of building an X-band Linear Collider in the late 1980's. Since then much effort has been expended in developing a reliable X-band Power source capable of delivering >50 MW RF power in pulse widths >1.5 {micro}s. I will report on some of the technical issues and design strategies which have led to the current SLAC klystron designs.

  13. Triaxial superdeformed bands in {sup 86}Zr

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.; LaFosse, D.R.; Devlin, M.; Lerma, F. [Chemistry Department, Washington University, St. Louis, Missouri 63130 (United States); Wood, V.Q.; Saladin, J.X.; Winchell, D.F. [Physics Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Baktash, C.; Yu, C. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Fallon, P.; Lee, I.Y.; Macchiavelli, A.O.; MacLeod, R.W. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Afanasjev, A.V.; Ragnarsson, I. [Department of Mathematical Physics, Lund Institute of Technology, Box 118, S-22100 Lund (Sweden)


    Four new superdeformed bands have been found in the nucleus {sup 86}Zr. The good agreement between experiment and configuration-dependent shell correction calculations suggests that three of the bands have triaxial superdeformed shapes. Such unique features in mass A{approximately}80 superdeformed bands have been predicted, but not observed experimentally until now. A fourth band in {sup 86}Zr is interesting due to a fairly constant and unusually high dynamic moment of inertia. Possible interpretations of this structure are discussed. {copyright} {ital 1998} {ital The American Physical Society}

  14. Band engineering of thermoelectric materials. (United States)

    Pei, Yanzhong; Wang, Heng; Snyder, G J


    Lead chalcogenides have long been used for space-based and thermoelectric remote power generation applications, but recent discoveries have revealed a much greater potential for these materials. This renaissance of interest combined with the need for increased energy efficiency has led to active consideration of thermoelectrics for practical waste heat recovery systems-such as the conversion of car exhaust heat into electricity. The simple high symmetry NaCl-type cubic structure, leads to several properties desirable for thermoelectricity, such as high valley degeneracy for high electrical conductivity and phonon anharmonicity for low thermal conductivity. The rich capabilities for both band structure and microstructure engineering enable a variety of approaches for achieving high thermoelectric performance in lead chalcogenides. This Review focuses on manipulation of the electronic and atomic structural features which makes up the thermoelectric quality factor. While these strategies are well demonstrated in lead chalcogenides, the principles used are equally applicable to most good thermoelectric materials that could enable improvement of thermoelectric devices from niche applications into the mainstream of energy technologies. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Solid State KA-Band, Solid State W-Band and TWT Amplifiers Project (United States)

    National Aeronautics and Space Administration — Phase I of the proposal describes plans to develop a state of the art transmitter for the W-Band and KA -Band Cloud Radar system. Our focus will be concentrated in...

  16. Atomic-Monolayer MoS2 Band-to-Band Tunneling Field-Effect Transistor

    KAUST Repository

    Lan, Yann Wen


    The experimental observation of band-to-band tunneling in novel tunneling field-effect transistors utilizing a monolayer of MoS2 as the conducting channel is demonstrated. Our results indicate that the strong gate-coupling efficiency enabled by two-dimensional materials, such as monolayer MoS2, results in the direct manifestation of a band-to-band tunneling current and an ambipolar transport.

  17. Error Analysis of Band Matrix Method


    Taniguchi, Takeo; Soga, Akira


    Numerical error in the solution of the band matrix method based on the elimination method in single precision is investigated theoretically and experimentally, and the behaviour of the truncation error and the roundoff error is clarified. Some important suggestions for the useful application of the band solver are proposed by using the results of above error analysis.

  18. Low-Noise Band-Pass Amplifier (United States)

    Kleinberg, L.


    Circuit uses standard components to overcome common limitation of JFET amplifiers. Low-noise band-pass amplifier employs JFET and operational amplifier. High gain and band-pass characteristics are achieved with suitable choice of resistances and capacitances. Circuit should find use as low-noise amplifier, for example as first stage instrumentation systems.

  19. Low band gap polymers for organic photovoltaics

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Krebs, Frederik C


    Low band gap polymer materials and their application in organic photovoltaics (OPV) are reviewed. We detail the synthetic approaches to low band gap polymer materials starting from the early methodologies employing quinoid homopolymer structures to the current state of the art that relies...

  20. Getting Elementary Students Involved in Band (United States)

    Moore, Patience


    The author discusses getting elementary students involved in a band. The goals of an elementary band instructor should include introduction of good practice habits, working within an ensemble, and rehearsal procedures, along with the focusing on the essentials of music. Instructors should let students use the basic instruments: flute, clarinet,…

  1. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)


    Mar 20, 2014 ... the deformed solution C (band D2). The intrinsic configurations of various excited bands are determined by the orbits near the Fermi surfaces. In figure 2, we show the orbits near the Fermi surfaces for the uncon- strained and constrained HF solutions of 82Ge. For the 'almost' spherical solution, the.

  2. Physical and electrical properties of induced high-k ZrHfO crystallization with ZrN cap by high power impulse magnetron sputtering for metal-gate metal-insulator-semiconductor structures (United States)

    Tsai, Jung-Ruey; Juan, Pi-Chun; Lin, Cheng-Li; Lin, Guo-Cheng


    Metal-gate TiN/ZrN/ZrHfO/p-Si metal-insulator-semiconductor (MIS) structures have been fabricated in this work. The physical and electrical properties were characterized. The crystallization of high-k ZrHfO thin-film is induced by high power impulse magnetron sputtering (HIPIMS) during the deposition of ZrN capping layer. The binding energies and depth profiles were investigated by X-ray photoelectron spectroscopy (XPS). It is found that Zr and Hf out-diffusion from high-k dielectric in samples with HIPIMS is lesser than those in samples with the conventional DC magnetron sputtering (DCMS). The dielectric constant which strongly relates to the tetragonal phase becomes higher and the flatband voltage shift shows smaller by using the HIPIMS method than by the conventional DCMS. The cation and anion vacancies have been investigated by the defect reaction model.

  3. Fluctuation diamagnetism in two-band superconductors (United States)

    Adachi, Kyosuke; Ikeda, Ryusuke


    Anomalously large fluctuation diamagnetism around the superconducting critical temperature has been recently observed in iron selenide (FeSe) [Kasahara et al. (unpublished)]. This indicates that superconducting fluctuations (SCFs) play a more significant role in FeSe, which supposedly has a two-band structure, than in the familiar single-band superconductors. Motivated by the data on FeSe, SCF-induced diamagnetism is examined in a two-band system, on the basis of a phenomenological approach with a Ginzburg-Landau functional. The obtained results indicate that the SCF-induced diamagnetism may be more enhanced than that in a single-band system due to the existence of two distinct fluctuation modes. Such enhancement of diamagnetism unique to a two-band system seems consistent with the large diamagnetism observed in FeSe, though still far from a quantitative agreement.

  4. Decorating TiO2Nanowires with BaTiO3Nanoparticles: A New Approach Leading to Substantially Enhanced Energy Storage Capability of High-k Polymer Nanocomposites. (United States)

    Kang, Da; Wang, Guanyao; Huang, Yanhui; Jiang, Pingkai; Huang, Xingyi


    The urgent demand of high energy density and high power density devices has triggered significant interest in high dielectric constant (high-k) flexible nanocomposites comprising dielectric polymer and high-k inorganic nanofiller. However, the large electrical mismatch between polymer and nanofiller usually leads to earlier electric failure of the nanocomposites, resulting in an undesirable decrease of electrical energy storage capability. A few studies show that the introduction of moderate-k shell onto a high-k nanofiller surface can decrease the dielectric constant mismatch, and thus, the corresponding nanocomposites can withstand high electric field. Unfortunately, the low apparent dielectric enhancement of the nanocomposites and high electrical conductivity mismatch between matrix and nanofiller still result in low energy density and low efficiency. In this study, it is demonstrated that encapsulating moderate-k nanofiller with high-k but low electrical conductivity shell is effective to significantly enhance the energy storage capability of dielectric polymer nanocomposites. Specifically, using BaTiO 3 nanoparticles encapsulated TiO 2 (BaTiO 3 @TiO 2 ) core-shell nanowires as filler, the corresponding poly(vinylidene fluoride-co-hexafluoropylene) nanocomposites exhibit superior energy storage capability in comparison with the nanocomposites filled by either BaTiO 3 or TiO 2 nanowires. The nanocomposite film with 5 wt % BaTiO 3 @TiO 2 nanowires possesses an ultrahigh discharged energy density of 9.95 J cm -3 at 500 MV m -1 , much higher than that of commercial biaxial-oriented polypropylene (BOPP) (3.56 J cm -3 at 600 MV m -1 ). This new strategy and corresponding results presented here provide new insights into the design of dielectric polymer nanocomposites with high electrical energy storage capability.

  5. Band-type microelectrodes for amperometric immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ga-Yeon; Chang, Young Wook; Ko, Hyuk [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Kang, Min-Jung [Korea Institute of Science and Technology (KIST), Seoul (Korea, Republic of); Pyun, Jae-Chul, E-mail: [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of)


    A band-type microelectrode was made using a parylene-N film as a passivation layer. A circular-type, mm-scale electrode with the same diameter as the band-type microelectrode was also made with an electrode area that was 5000 times larger than the band-type microelectrode. By comparing the amperometric signals of 3,5,3′,5′-tetramethylbenzidine (TMB) samples at different optical density (OD) values, the band-type microelectrode was determined to be 9 times more sensitive than the circular-type electrode. The properties of the circular-type and the band-type electrodes (e.g., the shape of their cyclic voltammograms, the type of diffusion layer used, and the diffusion layer thickness per unit electrode area) were characterized according to their electrode area using the COMSOL Multiphysics software. From these simulations, the band-type electrode was estimated to have the conventional microelectrode properties, even when the electrode area was 100 times larger than a conventional circular-type electrode. These results show that both the geometry and the area of an electrode can influence the properties of the electrode. Finally, amperometric analysis based on a band-type electrode was applied to commercial ELISA kits to analyze human hepatitis B surface antigen (hHBsAg) and human immunodeficiency virus (HIV) antibodies. - Highlights: • A band-type microelectrode was made using a parylene-N film as a passivation layer. • The band-type microelectrode was 14-times more sensitive than circular-type electrode. • The influence of geometry on microelectrode properties was simulated using COMSOL. • The band-type electrode was applied to ELISA kits for hHBsAg and hHIV-antibodies.

  6. Endoscopic Management of Eroded Bands Following Banded-Gastric Bypass (with Video). (United States)

    Shehab, Hany; Gawdat, Khaled


    Banded-gastric bypass is a highly effective bariatric procedure, yet the possibility of band erosion remains a significant drawback. Surgical removal of eroded bands may be associated with significant morbidity. In this study, we assess the efficacy and safety of a solely peroral endoscopic approach for the management of eroded bands in patients with a banded-gastric bypass. Starting January 2012, all patients with banded-gastric bypass and an eroded band were subjected to an attempt at peroral endoscopic removal using endoscopic scissors and/or argon plasma coagulation (APC), regardless of the circumference of band eroding inside the lumen. Sixteen patients presented with eroded bands, 2 were deemed not amenable to endoscopic removal as only part of the thickness was eroded. Of the 14 patients where endoscopic attempts were performed, 12 (86%) were completely removed successfully, while 2 (14%) were cut but could not be extracted and only the intraluminal portion was trimmed. Complete resolution of symptoms occurred in 13 (93%) while in 1 patient (7%) there was partial improvement. Only one endoscopic session was performed per patient with a median time of 37.5 min per session (22-55 min). No complications were encountered. Endoscopic removal of eroded gastric bands in patients with banded-gastric bypass is effective and safe in the majority of patients. When bands are adherent to the gastric wall, removal of the intraluminal portion of the band may lead to full or partial improvement of symptoms. Endoscopic band removal can be attempted even when a small part of band circumference has eroded.

  7. Light-induced gaps in semiconductor band-to-band transitions. (United States)

    Vu, Q T; Haug, H; Mücke, O D; Tritschler, T; Wegener, M; Khitrova, G; Gibbs, H M


    We observe a triplet around the third harmonic of the semiconductor band gap when exciting 50-100 nm thin GaAs films with 5 fs pulses at 3 x 10(12) W/cm(2). The comparison with solutions of the semiconductor Bloch equations allows us to interpret the observed peak structure as being due to a two-band Mollow triplet. This triplet in the optical spectrum is a result of light-induced gaps in the band structure, which arise from coherent band mixing. The theory is formulated for full tight-binding bands and uses no rotating-wave approximation.

  8. Electronic band structure of beryllium oxide

    CERN Document Server

    Sashin, V A; Kheifets, A S; Ford, M J


    The energy-momentum resolved valence band structure of beryllium oxide has been measured by electron momentum spectroscopy (EMS). Band dispersions, bandwidths and intervalence bandgap, electron momentum density (EMD) and density of occupied states have been extracted from the EMS data. The experimental results are compared with band structure calculations performed within the full potential linear muffin-tin orbital approximation. Our experimental bandwidths of 2.1 +- 0.2 and 4.8 +- 0.3 eV for the oxygen s and p bands, respectively, are in accord with theoretical predictions, as is the s-band EMD after background subtraction. Contrary to the calculations, however, the measured p-band EMD shows large intensity at the GAMMA point. The measured full valence bandwidth of 19.4 +- 0.3 eV is at least 1.4 eV larger than the theory. The experiment also finds a significantly higher value for the p-to-s-band EMD ratio in a broad momentum range compared to the theory.

  9. Interface dynamics and banding in rapid solidification

    Energy Technology Data Exchange (ETDEWEB)

    Karma, A.; Sarkissian, A. (Physics Department, Northeastern University, Boston, Massachusetts 02115 (United States))


    Rapid-solidification experiments on metallic alloys in the last decade have provided widespread observations of a novel banded structure.'' We report the results of numerical and analytical studies of the interface dynamics underlying the formation of this structure in a model of directional solidification which includes both solute and heat diffusion and nonequilibrium effects. The thrust of these studies is on the unsteady dynamics of the planar interface and thermal effects. The main conclusion is that the origin of banding can be related to relaxation oscillations of the solidification front, characterized by large variations of the interface velocity, which are dramatically affected by latent-heat diffusion. Without the latter, the oscillations are found to be reasonably well approximated by the phenomenological model of Carrard [ital et] [ital al]. [Acta Metall. 40, 983 (1992)], and the band spacing is inversely proportional to the temperature gradient. In contrast, with latent-heat diffusion the band spacing is insensitive to the temperature gradient, but is controlled instead by the interplay of solute and heat diffusion. The smallness of the solutal diffusivity to thermal diffusivity ratio is exploited to explain analytically this effect and to derive considerably simpler equations of interface motion that provide an efficient numerical means to study the nonplanar interface dynamics expected to cause dark bands. A reasonable agreement with experiment is found for the spacing of banded structures dominated by light-band microsegregation-free regions in Al-Fe alloys.

  10. Energy bands and gaps near an impurity

    Energy Technology Data Exchange (ETDEWEB)

    Mihóková, E., E-mail: [Institute of Physics, Acad. of Sciences of the Czech Rep., Cukrovarnická 10, 162 53 Prague 6 (Czech Republic); Schulman, L.S., E-mail: [Physics Department, Clarkson University, Potsdam, NY 13699-5820 (United States)


    It has been suggested that in the neighborhood of a certain kind of defect in a crystal there is a bend in the electronic band. We confirm that this is indeed possible using the Kronig–Penney model. Our calculations also have implications for photonic crystals. - Highlights: • Energy bands can bend near an impurity in the host lattice. • We confirm possibility of energy band bending by using Kronig–Penney model. • The impurity can have profound effect on wave function structure.

  11. A Dynamical Theory for Hurricane Spiral Bands (United States)


    dynamical fields from Hurricane Josephine (1984) ........... 4 1.2 Cross-band dynamical fields from Tropical Depression Irma (1987) .......... 5 1.3...FUNDING NUMBERS A Dynamical Theory for Hurricane Spii’al Bands 6. AUTHOR(S) Thomas A. Guinn, Captain 7. PERFORMING ORGANIZATION NAME(S) AND ADuRESS...S*nrdard Form 298 (R&v 2-89) 1 " I 0n, T ! ’’r." Author: Captain Thomas A. Guinn, USAF Title: A dynamical theory for hurricane spiral bands. Date

  12. Superdeformed bands in [sup 191]Tl

    Energy Technology Data Exchange (ETDEWEB)

    Pilotte, S.; Yu, C.; Jin, H.Q.; Lewis, J.M.; Riedinger, L.L. (Department of Physics, University of Tennessee, Knoxville, Tennessee 37996 (United States)); Liang, Y.; Janssens, R.V.F.; Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.; Soramel, F. (Argonne National Laboratory, Argonne, Illinois 60439 (United States)); Bearden, I.G. (Purdue University, West Lafayette, Indiana 47907 (United States)); Baktash, C.; Garrett, J.D.; Johnson, N.R.; Lee, I.Y.; McGowan, F.K. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States))


    High spin states in the [sup 191]Tl nucleus have been populated via the [sup 159]Tb ([sup 36]S,4[ital n]) reaction at 165 MeV. Two weakly populated rotational bands have been observed with properties (energy spacings and dynamic moments of inertia) very similar to those of other superdeformed bands in the [ital A][similar to]190 region. The two bands can be interpreted as signature partners which exhibit some signature splitting for rotational frequencies [h bar][omega][ge]0.2 MeV. They are interpreted within the framework of cranked Woods-Saxon calculations as being based on the proton [ital i][sub 13/2]([Omega]=5/2) intruder orbital, in agreement with pairs of superdeformed bands seen in neighboring odd Tl nuclei.

  13. The Novel Microwave Stop-Band Filter

    Directory of Open Access Journals (Sweden)

    R. E. Chernobrovkin


    Full Text Available The stop-band filter with the new band-rejection element is proposed. The element is a coaxial waveguide with the slot in the centre conductor. In the frame of this research, the numerical and experimental investigations of the amplitude-frequency characteristics of the filter are carried out. It is noted that according to the slot parameters the two typical resonances (half-wave and quarter-wave can be excited. The rejection band of the single element is defined by the width, depth, and dielectric filling of the slot. Fifth-order Chebyshev filter utilizing the aforementioned element is also synthesized, manufactured, and tested. The measured and simulated results are in good agreement. The experimental filter prototype exhibits the rejection band 0.86 GHz at the level −40 dB.

  14. Microbiological processes in banded iron formation deposition

    DEFF Research Database (Denmark)

    Posth, Nicole R.; Konhauser, Kurt O.; Kappler, Andreas


    Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals......, remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

  15. Simulating Precambrian banded iron formation diagenesis

    DEFF Research Database (Denmark)

    Posth, Nicole R.; K??hler, Inga; D. Swanner, Elizabeth


    Post-depositional diagenetic alteration makes the accurate interpretation of key precipitation processes in ancient sediments, such as Precambrian banded iron formations (BIFs), difficult. While microorganisms are proposed as key contributors to BIF deposition, the diagenetic transformation...

  16. C-band Scatterometers and Their Applications


    Naeimi, Vahid; Wagner, Wolfgang


    C-band scatterometers have demonstrated to be valuable sensors for large-scale observation of the Earth's surface in a variety of disciplines. High temporal sampling in all weather conditions, multi-viewing capability and availability of long-term measurements make the European C-band scatterometers excellent Earth observation tools. Scatterometer data are used to extract geophysical parameters such as wind speed and direction, surface soil moisture, seasonal dynamics of vegetation, spatial a...

  17. Intermediate bands and non radiative recombination


    Tablero Crespo, César; Martí Vega, Antonio; Fuertes Marrón, David; Antolín Fernández, Elisa; Luque López, Antonio


    The use of half-filled intermediate band materials has been proposed as a means to implement solar cells with efficiency exceeding that of single gap solar cells. An intermediate band can be regarded, at first, as a mere collection of energy levels within the semiconductor bandgap. However, its recombination properties are expected to be different from those traditionally attributed to deep levels. Hence, while deep centers behave mainly as non-radiative recombination centers, the IB is ...

  18. Optimal Band Allocation for Cognitive Cellular Networks


    Liu,Tingting; Jiang, Chengling


    FCC new regulation for cognitive use of the TV white space spectrum provides a new means for improving traditional cellular network performance. But it also introduces a number of technical challenges. This letter studies one of the challenges, that is, given the significant differences in the propagation property and the transmit power limitations between the cellular band and the TV white space, how to jointly utilize both bands such that the benefit from the TV white space for improving ce...

  19. Control Banding and Nanotechnology Synergist

    Energy Technology Data Exchange (ETDEWEB)

    Zalk, D; Paik, S


    The average Industrial Hygienist (IH) loves a challenge, right? Okay, well here is one with more than a few twists. We start by going through the basics of a risk assessment. You have some chemical agents, a few workers, and the makings of your basic exposure characterization. However, you have no occupational exposure limit (OEL), essentially no toxicological basis, and no epidemiology. Now the real handicap is that you cannot use sampling pumps, cassettes, tubes, or any of the media in your toolbox, and the whole concept of mass-to-dose is out the window, even at high exposure levels. Of course, by the title, you knew we were talking about nanomaterials (NM). However, we wonder how many IHs know that this topic takes everything you know about your profession and turns it upside down. It takes the very foundations that you worked so hard in college and in the field to master and pulls it out from underneath you. It even takes the gold standard of our profession, the quantitative science of exposure assessment, and makes it look pretty darn rusty. Now with NM there is the potential to get some aspect of quantitative measurements, but the instruments are generally very expensive and getting an appropriate workplace personal exposure measurement can be very difficult if not impossible. The potential for workers getting exposures, however, is very real, as evidenced by a recent publication reporting worker exposures to polyacrylate nanoparticles in a Chinese factory (Song et al. 2009). With something this complex and challenging, how does a concept as simple as Control Banding (CB) save the day? Although many IHs have heard of CB, most of their knowledge comes from its application in the COSHH Essentials toolkit. While there is conflicting published research on COSHH Essentials and its value for risk assessments, almost all of the experts agree that it can be useful when no OELs are available (Zalk and Nelson 2008). It is this aspect of CB, its utility with

  20. Rotational bands in {sup 169}Re

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.H.; Zhang, Y.H.; Zheng, Y. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Oshima, M.; Toh, Y.; Koizumi, M.; Osa, A.; Hayakawa, T.; Hatsukawa, Y.; Shizuma, T. [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Sugawara, M. [Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan)


    High-spin states in {sup 169}Re have been investigated by means of in-beam {gamma}-ray spectroscopy techniques with the {sup 144}Sm({sup 28}Si,1p2n{gamma}){sup 169}Re reaction. X-{gamma} and {gamma}-{gamma}-t coincidences, {gamma}-ray anisotropies, and DCO ratios were measured. A strongly coupled band based on the 9/2{sup -}[514] Nilsson state and a decoupled band built on the h{sub 9/2} intruder proton orbital (nominally 1/2{sup -}[541]) have been established. The AB neutron crossings are observed at {Dirac_h}{omega} = 0.23 and 0.27 MeV for the 9/2{sup -}[514] and 1/2{sup -}[541] bands, respectively. The 9/2{sup -}[514] band in {sup 169}Re shows the largest signature splitting at low spin among the odd-mass Re isotopes. Band properties of the AB neutron crossing frequencies, alignment gains, and signature splittings are discussed, and compared with those in the heavier odd-A Re isotopes. Additionally, a three-quasipariticle band is observed, and the {pi}9/2{sup -}[514] x {nu}AE configuration is proposed tentatively. (orig.)

  1. Rotational band structure in sup 75 Se

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, T.D.; Glasmacher, T.; Holcomb, J.W.; Womble, P.C.; Tabor, S.L. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)); Nazarewicz, W. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States) Joint Institute for Heavy Ion Research, Holifield Heavy Ion Research Facility, Oak Ridge, Tennessee 37831 (United States))


    The high-spin states of {sup 75}Se have been investigated using the {sup 59}Co ({sup 19}F, 2{ital pn}) reaction at 55 MeV. The positive-parity band has been extended to {ital I}{sup {pi}}=29/2{sup +} and the unfavored signature has been identified. The negative-parity band has been extended to {ital I}{sup {pi}}=19/2{sup {minus}} and band crossings were observed for the first time in both bands. Eleven new lifetimes were measured using the Doppler-shift attenuation method which allowed for extraction of transition strengths and transition quadrupole moments. The {ital B}({ital M}1) strengths exhibit a staggering dependent on the signature splitting. Calculations based on the Woods-Saxon-Bogolyubov cranking model explain the signature-dependent alignment process in the {ital g}{sub 9/2} bands and predict signature inversion in all bands at high rotational frequencies. It is argued that the data are consistent with the transition from triaxial shapes with {gamma}{similar to}{minus}30{degree}, characteristic of one-quasiparticle configurations, to triaxial shapes with {gamma}{similar to}30{degree}, characteristic of a three-quasiparticle configuration containing one aligned pair of {ital g}{sub 9/2} protons.

  2. Multicolor Karyotyping and Fluorescence In Situ Hybridization-Banding (MCB/mBAND). (United States)

    Liehr, Thomas; Othman, Moneeb A K; Rittscher, Katharina


    Multicolor fluorescence in situ hybridization (mFISH) approaches are routine applications in tumor as well as clinical cytogenetics nowadays. The first approach when thinking about mFISH is multicolor karyotyping using human whole chromosome paints as probes; this can be achieved by narrow-band filter-based multiplex-FISH (M-FISH) or interferometer/spectroscopy-based spectral karyotyping (SKY). Besides, various FISH-based banding approaches were reported in the literature, including multicolor banding (MCB/mBAND) the latter being evaluated by narrow-band filters, and using specific software. Here, we describe the combined application of multicolor karyotyping and MCB/mBAND for the characterization of simple and complex acquired chromosomal changes in cancer cytogenetics.

  3. Deformation bands evolving from dilation to cementation bands in a hydrocarbon reservoir (Vienna Basin, Austria) (United States)

    Exner, Ulrike; Kaiser, Jasmin; Gier, Susanne


    In this study we analyzed five core samples from a hydrocarbon reservoir, the Matzen Field in the Vienna Basin (Austria). Deformation bands occur as single bands or as strands of several bands. In contrast to most published examples of deformation bands in terrigeneous sandstones, the reduction of porosity is predominantly caused by the precipitation of Fe-rich dolomite cement within the bands, and only subordinately by cataclasis of detrital grains. The chemical composition of this dolomite cement (10–12 wt% FeO) differs from detrital dolomite grains in the host rock (<2 wt% FeO). This observation in combination with stable isotope data suggests that the cement is not derived from the detrital grains, but precipitated from a fluid from an external, non-meteoric source. After an initial increase of porosity by dilation, disaggregation and fragmentation of detrital grains, a Fe-rich carbonate fluid crystallized within the bands, thereby reducing the porosity relative to the host sediment. The retention of pyrite cement by these cementation bands as well as the different degree of oil staining on either side of the bands demonstrate that these cementation bands act as effective barriers to the migration of fluids and should be considered in reservoir models. PMID:26321782

  4. Topological structure of the inter-band phase difference soliton in two-band superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Y., E-mail: y.tanaka@aist.go.j [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Iyo, A. [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Tokiwa, K.; Watanabe, T. [Tokyo University of Science, Noda (Japan); Crisan, A. [University of Birmingham, Birmingham (United Kingdom); National Institute of Materials Physics, Bucharest (Romania); Sundaresan, A. [Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore (India); Terada, N. [Kagoshima University, Kagoshima (Japan)


    Two-component superconductivity based on the two-band superconductor has a functional topology such as an inter-band phase difference soliton (i-soliton) to realize topological electronics (topolonics). Many gauge field theories are applied to investigate the topology of two-band superconductivity. To ease experimental and electronics applications, these theories should be refined. Weinberg-Salam theory and SU(2) (two-dimensional special unitary symmetry) gauge field theory are proper starting points. An effective extra force field because of the crystal structure and inter-band Josephson interaction, rather than spontaneous symmetry breaking, simplifies the conventional gauge field theory.

  5. Percutaneous tension band wiring for patellar fractures. (United States)

    Rathi, Akhilesh; Swamy, M K S; Prasantha, I; Consul, Ashu; Bansal, Abhishek; Bahl, Vibhu


    To evaluate outcome of percutaneous tension band wiring for transverse fractures of the patella. 16 men and 7 women aged 27 to 65 (mean, 40) years underwent percutaneous tension band wiring for transverse fractures of the patella with a displacement of >3 mm. Pain, operating time, mobility, functional score, and complications were evaluated. 20 patients underwent successful percutaneous tension band wiring. The remaining 3 patients in whom closed reduction failed underwent open reduction and tension band wiring. The mean operating time was 46 (range, 28-62) minutes. The mean follow-up period was 20 (range, 15-30) months. At the latest follow-up, all patients had regained full extension. The objective score was excellent in 20 patients and good in 3, whereas the subjective score was excellent in 17, good in 5, and fair in one. All patients had radiological union at week 8. One patient had patellofemoral arthritis (secondary to a postoperative articular step). Two patients developed superficial infections, which resolved after antibiotic therapy. Mean thigh muscle wasting was 0.7 (range, 0.4-1) cm. Three patients encountered hardware problems (impingement/irritation of the skin over the knee) necessitating implant removal. Percutaneous tension band wiring is a viable option for transverse fractures of the patella.

  6. Automated coregistration of MTI spectral bands.

    Energy Technology Data Exchange (ETDEWEB)

    Theiler, J. P. (James P.); Galbraith, A. E. (Amy E.); Pope, P. A. (Paul A.); Ramsey, K. A. (Keri A.); Szymanski, J. J. (John J.)


    In the focal plane of a pushbroom imager, a linear array of pixels is scanned across the scene, building up the image one row at a time. For the Multispectral Thermal Imager (MTI), each of fifteen different spectral bands has its own linear array. These arrays are pushed across the scene together, but since each band's array is at a different position on the focal plane, a separate image is produced for each band. The standard MTI data products resample these separate images to a common grid and produce coregistered multispectral image cubes. The coregistration software employs a direct 'dead reckoning' approach. Every pixel in the calibrated image is mapped to an absolute position on the surface of the earth, and these are resampled to produce an undistorted coregistered image of the scene. To do this requires extensive information regarding the satellite position and pointing as a function of time, the precise configuration of the focal plane, and the distortion due to the optics. These must be combined with knowledge about the position and altitude of the target on the rotating ellipsoidal earth. We will discuss the direct approach to MTI coregistration, as well as more recent attempts to 'tweak' the precision of the band-to-band registration using correlations in the imagery itself.

  7. Band warping, band non-parabolicity, and Dirac points in electronic and lattice structures (United States)

    Resca, Lorenzo; Mecholsky, Nicholas A.; Pegg, Ian L.


    We illustrate at a fundamental level the physical and mathematical origins of band warping and band non-parabolicity in electronic and vibrational structures. We point out a robust presence of pairs of topologically induced Dirac points in a primitive-rectangular lattice using a p-type tight-binding approximation. We analyze two-dimensional primitive-rectangular and square Bravais lattices with implications that are expected to generalize to more complex structures. Band warping is shown to arise at the onset of a singular transition to a crystal lattice with a larger symmetry group, which allows the possibility of irreducible representations of higher dimensions, hence band degeneracy, at special symmetry points in reciprocal space. Band warping is incompatible with a multi-dimensional Taylor series expansion, whereas band non-parabolicities are associated with multi-dimensional Taylor series expansions to all orders. Still band non-parabolicities may merge into band warping at the onset of a larger symmetry group. Remarkably, while still maintaining a clear connection with that merging, band non-parabolicities may produce pairs of conical intersections at relatively low-symmetry points. Apparently, such conical intersections are robustly maintained by global topology requirements, rather than any local symmetry protection. For two p-type tight-binding bands, we find such pairs of conical intersections drifting along the edges of restricted Brillouin zones of primitive-rectangular Bravais lattices as lattice constants vary relatively to each other, until these conical intersections merge into degenerate warped bands at high-symmetry points at the onset of a square lattice. The conical intersections that we found appear to have similar topological characteristics as Dirac points extensively studied in graphene and other topological insulators, even though our conical intersections have none of the symmetry complexity and protection afforded by the latter more

  8. Band structure engineering in organic semiconductors (United States)

    Schwarze, Martin; Tress, Wolfgang; Beyer, Beatrice; Gao, Feng; Scholz, Reinhard; Poelking, Carl; Ortstein, Katrin; Günther, Alrun A.; Kasemann, Daniel; Andrienko, Denis; Leo, Karl


    A key breakthrough in modern electronics was the introduction of band structure engineering, the design of almost arbitrary electronic potential structures by alloying different semiconductors to continuously tune the band gap and band-edge energies. Implementation of this approach in organic semiconductors has been hindered by strong localization of the electronic states in these materials. We show that the influence of so far largely ignored long-range Coulomb interactions provides a workaround. Photoelectron spectroscopy confirms that the ionization energies of crystalline organic semiconductors can be continuously tuned over a wide range by blending them with their halogenated derivatives. Correspondingly, the photovoltaic gap and open-circuit voltage of organic solar cells can be continuously tuned by the blending ratio of these donors.

  9. Obituary: David L. Band (1957-2009) (United States)

    Cominsky, Lynn


    David L. Band, of Potomac Maryland, died on March 16, 2009 succumbing to a long battle with spinal cord cancer. His death at the age of 52 came as a shock to his many friends and colleagues in the physics and astronomy community. Band showed an early interest and exceptional aptitude for physics, leading to his acceptance at the Massachusetts Institute of Technology as an undergraduate student in 1975. After graduating from MIT with an undergraduate degree in Physics, Band continued as a graduate student in Physics at Harvard University. His emerging interest in Astrophysics led him to the Astronomy Department at the Harvard Smithsonian Center for Astrophysics (CfA), where he did his dissertation work with Jonathan Grindlay. His dissertation (1985) entitled "Non-thermal Radiation Mechanisms and Processes in SS433 and Active Galactic Nuclei" was "pioneering work on the physics of jets arising from black holes and models for their emission, including self-absorption, which previewed much to come, and even David's own later work on Gamma-ray Bursts," according to Grindlay who remained a personal friend and colleague of Band's. Following graduate school, Band held postdoctoral positions at the Lawrence Livermore Laboratory, the University of California at Berkeley and the Center for Astronomy and Space Sciences at the University of California San Diego where he worked on the BATSE experiment that was part of the Compton Gamma Ray Observatory (CGRO), launched in 1991. BATSE had as its main objective the study of cosmic gamma-ray bursts (GRBs) and made significant advances in this area of research. Band became a world-renowned figure in the emerging field of GRB studies. He is best known for his widely-used analytic form of gamma-ray burst spectra known as the "Band Function." After the CGRO mission ended, Band moved to the Los Alamos National Laboratory where he worked mainly on classified research but continued to work on GRB energetics and spectra. When NASA planned

  10. Simplicial band depth for multivariate functional data

    KAUST Repository

    López-Pintado, Sara


    We propose notions of simplicial band depth for multivariate functional data that extend the univariate functional band depth. The proposed simplicial band depths provide simple and natural criteria to measure the centrality of a trajectory within a sample of curves. Based on these depths, a sample of multivariate curves can be ordered from the center outward and order statistics can be defined. Properties of the proposed depths, such as invariance and consistency, can be established. A simulation study shows the robustness of this new definition of depth and the advantages of using a multivariate depth versus the marginal depths for detecting outliers. Real data examples from growth curves and signature data are used to illustrate the performance and usefulness of the proposed depths. © 2014 Springer-Verlag Berlin Heidelberg.

  11. Hubbard-U band-structure methods

    DEFF Research Database (Denmark)

    Albers, R.C.; Christensen, Niels Egede; Svane, Axel


    The last decade has seen a large increase in the number of electronic-structure calculations that involve adding a Hubbard term to the local-density approximation band-structure Hamiltonian. The Hubbard term is then determined either at the mean-field level or with sophisticated many-body techniq......-structure theory. Alternatively, it may also be considered that they are just based on a Hubbard model that is more complex than the simple one- or few-band models traditionally used in many-body theories of solids....... are inconsistent with what the calculations actually do. Although many of these calculations are often treated as essentially first-principles calculations, in fact, we argue that they should be viewed from an entirely different point of view, namely, as based on phenomenological many-body corrections to band...

  12. Plasmonic band structures in doped graphene tubes. (United States)

    Zhou, Yu; Zhu, Ying-Ying; Zhang, Kun; Wu, Hong-Wei; Peng, Ru-Wen; Fan, Ren-Hao; Wang, Mu


    We present theoretically the transport of plasmonic waves in doped graphene tube, which is made by rolling planar graphene sheet into a cylinder and periodic doping is applied on it. It is shown that periodic modulation of the Fermi level along the tube can open gaps in the dispersion relations of graphene plasmons and eventually create plasmonic band structures. The propagation of graphene plasmons is forbidden within the bandgaps; while within the band, the plasmonic waves present axially-extended field distributions and propagate along the tubes, yet well confined around the curved graphene surface. Furthermore, the bandgaps, propagation constants and propagation lengths of the modes in plasmonic band structures are significantly tuned by varying the Fermi level of graphene, which provides active controls over the plasmonic waves. Our proposed structures here may provide an approach to dynamically control the plasmonic waves in graphene-based subwavelength waveguides.

  13. What band rocks the MTB? (Invited) (United States)

    Kind, J.; García-Rubio, I.; Gehring, A. U.


    Magnetotactic bacteria (MTB) are a polyphyletic group of bacteria that have been found in marine and lacustrine environments and soils [e.g. 1]. The hallmark of MTB is their intracellular formation of magnetosomes, single-domain ferrimagnetic particles that are aligned in chains. The chain configuration generates a strong magnetic dipole, which is used as magnetic compass to move the MTB into their favorable habit. The term band corresponds to a frequency window of microwaves in the gigahertz (GHz) range. Ferromagnetic resonance (FMR) spectroscopy uses the microwave absorption in a magnetic field to analyze the anisotropy properties and the domain state of magnetic materials. Specific microwave frequency causes absorption in a characteristic magnetic field range. For the investigation of MTB we use S-band (4.02 GHz), X-band (9.47 GHz), and Q-band (34.16 GHz). Experiments on cultured MTB and on sediment samples of Holocene age showed that absorption in X- and Q-band occurs when the sample is in a saturated or nearly saturated state [2, 3]. By contrast, absorption in the S-band appears in lower magnetic fields, where the sample is far from saturation. All FMR spectra show two distinct low-field features that can be assigned to magnetite particles in chains, aligned parallel and perpendicular to the external magnetic field. The detailed separation of the parallel and perpendicular components in the bulk samples is hampered, because of the random orientation of the chains in the sample. The comparison of S-, X-, and Q-band shows that the lower the frequency the better the separation of the components. In the S-band FMR spectroscopy, the separation of chains parallel to the external magnetic field is supported by the internal field of the sample. This field is caused by the remanence that contributes to the external magnetic field to fulfill the resonance condition [3,4]. Considering the different FMR responses, it can be postulated that a lower microwave frequency

  14. [Intragastric migration of adjustable gastroplasty bands]. (United States)

    Maziere, C; Rault, A; Sa Cunha, A; Collet, D


    The incidence of morbid obesity is increasing in France; adjustable gastric banding has become the most common surgical treatment. We report seven cases of patients who presented with gastric erosion as a complication of gastric banding; this occurred at a mean interval of 4 years following the initial bariatric procedure. In six cases, repair was performed laparoscopically; one case required conversion to an open laparotomy approach. There was no mortality but morbidity occurred in 57% of cases: pleural effusion (two) and wound abscess (two). Gastric erosion and migration of adjustable gastric rings can occur at a long interval after laparoscopic gastric banding. Long-term follow-up is necessary in all such patients.

  15. S-band active array filtenna with enhanced X-band spurious interference suppression

    NARCIS (Netherlands)

    Cifola, L.; Gerini, G.; Berg, S. van den; Water, F. van de


    In the present work, the design of an S-band active array antenna with inherent frequency selectivity properties is described. The radiating element, based on a stacked-patch configuration, is characterized by an operational bandwidth of [2.8-3.4] GHz. In-band frequency selectivity is performed by a

  16. Fuzzy Riesz subspaces, fuzzy ideals, fuzzy bands and fuzzy band projections


    Hong Liang


    Fuzzy ordered linear spaces, Riesz spaces, fuzzy Archimedean spaces and $\\sigma$-complete fuzzy Riesz spaces were defined and studied in several works. Following the efforts along this line, we define fuzzy Riesz subspaces, fuzzy ideals, fuzzy bands and fuzzy band projections and establish their fundamental properties.

  17. Lap-band: outcomes and results. (United States)

    O'Brien, Paul E; Dixon, John B


    Laparoscopic adjustable gastric banding was first introduced in the early 1990s as a potentially safe, controllable, and reversible method for achieving significant weight loss in the severely obese. The Bioenterics Lap-Band system (Inamed Health, Santa Barbara, California) is the device most commonly used. After 10 years of experience in treating more than 100000 patients with the Lap-Band, it is timely for us to review the outcomes. Data for the review are derived from the experience of our unit in the treatment of 1250 patients to date, from an independent systematic review of the published literature up to September 2001, and from major studies published after the date of closure of the systematic review. Lap-Band placement has proved to be a very safe procedure with a mortality rate in the published reports of 1 in 2000, only 10% of the published mortality rate of gastric bypass. The early complication rate has been very low, but late complications of prolapse or erosions have been more frequent, particularly during the early experience. Weight is lost during the first 2 to 3 years after surgery. The systematic review reports 56% excess weight loss (EWL) at 5 years (three reports). In comparison, Roux-en-Y gastric bypass (RYGB) is reported to have achieved 59% EWL at 5 years (four reports). Major improvements in comorbid conditions have been reported in association with weight loss after Lap-Band placement. Most importantly, type 2 diabetes is usually cured, and insulin resistance and reduced pancreatic beta-cell function are reversed. Gastroesophageal reflux, obstructive sleep apnea, and depression are other diseases in which marked improvement is noted. Quality-of-life scores return to normal values. Lap-Band placement is proving to be safe and effective. In view of the attributes of adjustability, safe laparoscopic placement, and reversibility, it should be considered the optimal initial approach for the control of obesity and its comorbid conditions.

  18. Nanoscale Studies of Energy Band Gaps and Band Offsets in Compound Semiconductor Heterostructures (United States)

    Chang, Alexander S.

    The identification of the precise band offsets at semiconductor interfaces is crucially important for the successful development of electronic and optoelectronic devices. However, issues at the interfaces, such as strain or defects, needs to be investigated for precise band tuning of semiconductor heterostructures. In this dissertation, the nanometer-scale structural and electronic properties of InGaAs(Sb)N/GaAs interfaces, InGaN/GaN QDs, and GaSb/GaAs QDs are investigated using a combination of XSTM and STS. The influence of Sb incorporation on the InGaAs(Sb)N/GaAs band alignment is investigated. At the InGaAsN/GaAs (InGaAsSbN/GaAs) interfaces, type II (type I) band offsets are observed, due to strain-induced splitting of the valence band and the incorporation of Sb. Band tuning of both conduction and valence band edges with the incorporation of Sb can be used to engineer the band structure with strong confinement of electrons and holes in the InGaAsSbN quantum well layer, which is promising for light emitting applications. The influence of the growth substrate on InGaN/GaN QD formation and properties is examined. The QD density, dimension, and band gaps are compared for different InGaN QDs on free-standing GaN or GaN/AlN/sapphire substrates. We present different sources using nucleation on different substrates, and discuss their influences on the electronic band structure. Our work suggests that a wide variety of InGaN QD dimension, density, and band structure can be achieved by using different starting substrate and number of layers of InGaN QD stacks. Furthermore, the influence of strain and dislocation on the GaSb/GaAs QD band alignment is investigated using both experimental and computational tools. A combination of cross-sectional transmission electron microscopy (XTEM), XSTM, and STS reveals the formation of misfit dislocations and both coherent and semi-coherent clustered QDs, independent of Sb- vs. As-termination of the GaAs surface. Furthermore, finite

  19. Planar Tri-Band Antenna Design

    Directory of Open Access Journals (Sweden)

    M. Pokorny


    Full Text Available The paper briefly uncovers techniques used for a design of compact planar antennas in order to achieve the wideband and the multi-band capability. The main topic is aimed to the multi-objective optimization using genetic algorithms. A quarter-wavelength planar inverted-F antenna (PIFA using a slot and shorted parasitic patches is chosen to cover GSM900, GSM1800 and ISM2400 bands. A global multi-objective optimization uses a binary genetic algorithm with a composite objective function to tune this antenna. The impedance match and the direction of maximum gain are desired parameters to improve.

  20. Ka-band waveguide rotary joint

    KAUST Repository

    Yevdokymov, Anatoliy


    The authors present a design of a waveguide rotary joint operating in Ka-band with central frequency of 33 GHz, which also acts as an antenna mount. The main unit consists of two flanges with a clearance between them; one of the flanges has three circular choke grooves. Utilisation of three choke grooves allows larger operating clearance. Two prototypes of the rotary joint have been manufactured and experimentally studied. The observed loss is from 0.4 to 0.8 dB in 1.5 GHz band.

  1. Band coupling and crossing in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nojarov, R. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika; Sofia Univ. (Bulgaria). Fizicheski Fakultet); Nadjakov, E. (Joint Inst. for Nuclear Research, Dubna (USSR))


    A model of coupled rotational bands, including three types of phonons, ..beta.., ..gamma.. and S(Ksup(..pi..) = 1/sup +/ or O/sup +/), is proposed and applied to a number of even-even rare earth back-bending nuclei. It reproduces the most complicated experimentally known multiple-band crossings in /sup 154/Gd, /sup 156/Dy, /sup 164/Er and the clockwise circling of the yrast B(E2) values (versus 2/) in back-bending nuclei. The direct coupling strengths, derived from a fit to experimental data, are discussed in detail.

  2. Maximizing band gaps in plate structures

    DEFF Research Database (Denmark)

    Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard


    periodic plate using Bloch theory, which conveniently reduces the maximization problem to that of a single base cell. Secondly, we construct a finite periodic plate using a number of the optimized base cells in a postprocessed version. The dynamic properties of the finite plate are investigated......Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...

  3. Band theory of metals the elements

    CERN Document Server

    Altmann, Simon L


    Band Theory of Metals: The Elements focuses on the band theory of solids. The book first discusses revision of quantum mechanics. Topics include Heisenberg's uncertainty principle, normalization, stationary states, wave and group velocities, mean values, and variational method. The text takes a look at the free-electron theory of metals, including heat capacities, density of states, Fermi energy, core and metal electrons, and eigenfunctions in three dimensions. The book also reviews the effects of crystal fields in one dimension. The eigenfunctions of the translations; symmetry operations of t

  4. Three Magnetic Rotation Bands in 84^Rb


    Shen, Shuifa; Zhao, Xin; Han, Guangbing; Wen, Shuxian; Yan, Yupeng; Wu, Xiaoguang; Zhu, Lihua; He, Chuangye; Li,Guangsheng


    High-spin states in $^{84}$Rb are studied by using the $^{70}$Zn($^{18}$O, p3n)$^{84}$Rb reaction at beam energy of 75 MeV. Three high-lying negative-parity bands are established, whose level spacings are very regular, i.e., there don't exist signature splitting. The dipole character of the transitions of these three bands is assigned by the $\\gamma$-$\\gamma$ directional correlations of oriented states (DCO) intensity ratios and the multipolarity M1 is suggested by the analogy to multiparticl...

  5. Calcific band keratopathy in an alpaca. (United States)

    Pucket, Jonathan D; Boileau, Melanie J; Sula, Mee Ja M


    A 4-year-old female Suri alpaca was presented for evaluation of acute onset weakness, lethargy, and recent development of opacities in both eyes. On ophthalmic examination, bilaterally symmetrical corneal opacities were noted along the interpalpebral fissures with a few corneal blood vessels intermingled. A presumed diagnosis of calcific band keratopathy was made based on location and appearance. The patient was euthanized a short while after diagnosis due to reasons unrelated to the eyes and histologic examination of the corneas revealed subepithelial calcium and vascularization, consistent with calcific band keratopathy. This case report is the first to document this ocular condition in an alpaca. © 2013 American College of Veterinary Ophthalmologists.

  6. Inversion of band patterns in spherical tumblers. (United States)

    Chen, Pengfei; Lochman, Bryan J; Ottino, Julio M; Lueptow, Richard M


    Bidisperse granular mixtures in spherical tumblers segregate into three bands: one at each pole and one at the equator. For low fill levels, large particles are at the equator; for high fill levels, the opposite occurs. Segregation is robust, though the transition depends on fill level, particle size, and rotational speed. Discrete element method simulations reproduce surface patterns and reveal internal structures. Particle trajectories show that small particles flow farther toward the poles than large particles in the upstream portion of the flowing layer for low fill levels leading to a band of small particles at each pole. The opposite occurs for high fill levels, though more slowly.

  7. Proximal iliotibial band syndrome: case report

    Directory of Open Access Journals (Sweden)

    Guilherme Guadagnini Falotico


    Full Text Available OBJECTIVE: The overuse injuries in the hip joint occur commonly in sports practitioners and currently due to technical advances in diagnostic imaging, especially magnetic resonance imaging (MRI, are often misdiagnosed. Recently, a group of people were reported, all female, with pain and swelling in the pelvic region.T2-weighted MRI showed increased signal in the enthesis of the iliotibial band (ITB along the lower border of the iliac tubercle. We report a case of a 34 year old woman, non-professional runner, with pain at the iliac crest with no history of trauma and whose MRI was compatible with the proximal iliotibial band syndrome.

  8. Absorption bands in the spectrum of Io (United States)

    Cruikshank, D. P.; Jones, T. J.; Pilcher, C. B.


    Near-infrared spectra of Io in the region from 2.8 to 4.2 microns are reported which show distinct absorption features, the most notable at 4.1 microns. Frozen volatiles or atmospheric gases cannot account for these absorptions, nor do they resemble those seen in common silicate rocks. Several candidate substances, most notably nitrate and carbonate salts, show absorption features in this spectral region; the deepest band in the spectrum may be a nitrate absorption. The satellite surface is shown to be anhydrous, as indicated by the absence of the 3-micron bound water band.

  9. Measurement of the Band-to-Band Registration of the SNPP VIIRS Imaging System from On-Orbit Data (United States)

    Tilton, James C.; Lin, Guoqing; Tan, Bin


    The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched 28 October 2011 onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite. The VIIRS instrument is a whiskbroom system with 22 spectral and thermal bands split between 16 moderate resolution bands (M-bands), five imagery resolution bands (I-bands) and a day-night band. In this study we measure the along-scan and along-track band-to-band registration between the I-bands and M-bands from on-orbit data. This measurement is performed by computing the Normalized Mutual Information (NMI) between shifted image band pairs and finding the amount of shift required (if any) to produce the peak in NMI value. Subpixel accuracy is obtained by utilizing bicubic interpolation. Registration shifts are found to be similar to pre-launch measurements and stable (within measurement error) over the instruments first four years in orbit.


    Directory of Open Access Journals (Sweden)

    Atang Riyan Isnandar


    Full Text Available Abstrak Forgotten merupakan band asal kota Bandung yang beraliran death metal. Band ini telah memiliki beberapa album yang cukup sukses. Salah satu faktor yang turut berperan penting dalam album-album Forgotten adalah desain sampul album. Sampul album merupakan identitas dan pesan dari musik yang dibawakan oleh Forgotten. Dalam sampul album, terdapat salah satu elemen visual yaitu Tipografi. Salah satu peran tipografi dalam sampul album Forgotten adalah sebagai logotype dari band. Yang menarik, dari lima album yang telah dirilis Forgotten yaitu “Future Syndrome” (1997, “Obsesi Mati” (2000, “Tuhan Telah Mati” (2001, “Tiga Angka Enam” (2003 dan “Laras Perlaya” (2011 adalah tampilan logotype band yang selalu berbeda. Perubahan logotype Forgotten disebabkan oleh beberapa faktor seperti adanya perubahan selera, transformasi musik dan pergantian personil yang dialami oleh band Forgotten. Perubahan ini berakibat pada munculnya kesan visual yang berbeda-beda dari masing-masing logotype di setiap sampul albumnya. Apalagi logotype band dengan genre death metal memiliki kecendrungan yang unik, dekoratif, bahkan sulit untuk dibaca. Oleh karena itu untuk mengetahui kesan visual yang dimunculkan oleh setiap logotype akan dilakukan penelitian dengan pendekatan tipografi. Tujuan dari penelitian ini adalah selain untuk mengetahui perubahan logotype dari kelima sampul album yang telah dirilis oleh Forgotten juga ingin mengetahui kesan visual terhadap tipografi terkait dengan prinsip kejelasan (legibility, keterbacaan (readability dan kemampuannya untuk dilihat pada jarak tertentu (visibility. Kata Kunci: Sampul Album, Tipografi, Logotype, Forgotten Abstract Forgotten is a band from Bandung, the death metal genre. The band has had some fairly successful album. One of important factor in albums Forgotten is the album cover design. The album cover are the identity and the message of the music performed by the Forgotten. In the cover of the album

  11. 47 CFR 15.714 - TV bands database administration fees. (United States)


    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administration fees. 15.714 Section 15.714 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Television Band Devices § 15.714 TV bands database administration fees. (a) A TV bands database administrator...

  12. 47 CFR 15.715 - TV bands database administrator. (United States)


    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administrator. 15.715 Section... Band Devices § 15.715 TV bands database administrator. The Commission will designate one or more entities to administer a TV bands database. Each database administrator shall: (a) Maintain a database that...

  13. Decreasing patient identification band errors by standardizing processes. (United States)

    Walley, Susan Chu; Berger, Stephanie; Harris, Yolanda; Gallizzi, Gina; Hayes, Leslie


    Patient identification (ID) bands are an essential component in patient ID. Quality improvement methodology has been applied as a model to reduce ID band errors although previous studies have not addressed standardization of ID bands. Our specific aim was to decrease ID band errors by 50% in a 12-month period. The Six Sigma DMAIC (define, measure, analyze, improve, and control) quality improvement model was the framework for this study. ID bands at a tertiary care pediatric hospital were audited from January 2011 to January 2012 with continued audits to June 2012 to confirm the new process was in control. After analysis, the major improvement strategy implemented was standardization of styles of ID bands and labels. Additional interventions included educational initiatives regarding the new ID band processes and disseminating institutional and nursing unit data. A total of 4556 ID bands were audited with a preimprovement ID band error average rate of 9.2%. Significant variation in the ID band process was observed, including styles of ID bands. Interventions were focused on standardization of the ID band and labels. The ID band error rate improved to 5.2% in 9 months (95% confidence interval: 2.5-5.5; P < .001) and was maintained for 8 months. Standardization of ID bands and labels in conjunction with other interventions resulted in a statistical decrease in ID band error rates. This decrease in ID band error rates was maintained over the subsequent 8 months.

  14. 47 CFR 15.713 - TV bands database. (United States)


    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database. 15.713 Section 15.713... TV bands database. (a) Purpose. The TV bands database serves the following functions: (1) To... databases. (b) Information in the TV bands database. (1) Facilities already recorded in Commission databases...

  15. High spin rotational bands in Zn

    Indian Academy of Sciences (India)

    July 2001 physics pp. 181–184. High spin rotational bands in. 65. Zn. B MUKHERJEE, S MURALITHAR, R P SINGH, R KUMAR, K RANI and. R K BHOWMIK. Nuclear Science Centre, Aruna Asaf Ali Marg, P.B. No. .... resolved due to poor resolution of the detectors used. The measured DCO ratios for the 835,. 988, 1074 ...

  16. Statistical study of auroral omega bands (United States)

    Partamies, Noora; Weygand, James M.; Juusola, Liisa


    The presence of very few statistical studies on auroral omega bands motivated us to test-use a semi-automatic method for identifying large-scale undulations of the diffuse aurora boundary and to investigate their occurrence. Five identical all-sky cameras with overlapping fields of view provided data for 438 auroral omega-like structures over Fennoscandian Lapland from 1996 to 2007. The results from this set of omega band events agree remarkably well with previous observations of omega band occurrence in magnetic local time (MLT), lifetime, location between the region 1 and 2 field-aligned currents, as well as current density estimates. The average peak emission height of omega forms corresponds to the estimated precipitation energies of a few keV, which experienced no significant change during the events. Analysis of both local and global magnetic indices demonstrates that omega bands are observed during substorm expansion and recovery phases that are more intense than average substorm expansion and recovery phases in the same region. The omega occurrence with respect to the substorm expansion and recovery phases is in a very good agreement with an earlier observed distribution of fast earthward flows in the plasma sheet during expansion and recovery phases. These findings support the theory that omegas are produced by fast earthward flows and auroral streamers, despite the rarity of good conjugate observations.

  17. Photon side-bands in mesoscopics

    DEFF Research Database (Denmark)

    Jauho, Antti-Pekka


    This paper reviews several applications of photonic side bands, used by Buttiker and Landauer (Phys. Rev. Lett. 49, 1739 (1982)) in their theory of traversal time in tunneling, in transport and optics of mesoscopic systems. Topics include generalizations of the transmission theory of transport...

  18. X/Ka-band Global Astrometric Results (United States)

    Jacobs, Christopher S.; Sovers, O. J.


    In order to extend the International Celestial Reference Frame from its S/X- band (2.3/8.4 GHz) basis to a complementary frame at X/Ka-band (8.4/32 GHz), a series of X/Ka observations were acquired from 2005 to 2009 using NASA's Deep Space Network radio telescopes. We report global astrometric results from the first 41 sessions which covered right ascension over the full 24 hours and declination down to a southern limit of ∼-45 deg. We detected 328 sources. Of these, 313 sources had at least 2 group delay measurements which were used to produce a nearly full sky catalog with median formal position uncertainties of 200 and 340 μas in α cos(δ) and δ, respectively. An external comparison of our X/Ka-band frame to a sucessor of the S/X-band ICRF shows 313 common sources with median absolute differences of 184 μas in Δα cos(δ) and 240 μas in Δδ. These differences include zonal errors the largest of which are trends vs. declination. Systematic errors are due in part to the geometric weakness of using just two baselines and in part to mismodelling of troposphere and uncalibrated instrumental effects. Prospects for the future improvements are very positive with demonstrated technologies showing potential for a factor of three improvement in measurement precision.

  19. Assessing Individual Performance in the College Band (United States)

    Reimer, Mark U.


    Semester assessment of college wind band members is an issue that conductors would probably agree falls within their academic freedom. Institutions may award as little as no credit or even a percentage of a credit for ensemble participation, although the time and effort required of the students and their conductor is undoubtedly equivalent to, or…

  20. Tension band fixation of medial malleolus fractures. (United States)

    Ostrum, R F; Litsky, A S


    A prospective study on tension band fixation of medial malleolus fractures was performed on 30 consecutive patients with 31 fractures from October 1987 until December 1990. All patients had at least a displaced medial malleolus fracture unreduced by closed methods. The fractures were classified into small, medium and large using a modified Lauge-Hansen classification. There were no nonunions or movements of wires postoperatively and only two patients had subjective complaints with reference to the wires that required hardware removal. There was one 2-mm malreduction and one patient with a wound slough and subsequent osteomyelitis. One fragment had 2 mm of displacement after fixation but went on to union. A biomechanical study was undertaken to compare fixation of the medial malleolus with K wires alone, K wires plus a tension band, and two cancellous screws. The tension band fixation provided the greatest resistance to pronation forces: for times stiffer than the two screws and 62% of the intact specimen. Tension band fixation of the medial malleolus is a biomechanically strong and clinically acceptable method of treatment for displaced medial malleolus fractures. This method of fixation may be especially useful for small fragments and in osteoporotic bone.

  1. Superconducting transitions in flat-band systems (United States)

    Iglovikov, V. I.; Hébert, F.; Grémaud, B.; Batrouni, G. G.; Scalettar, R. T.


    The physics of strongly correlated quantum particles within a flat band was originally explored as a route to itinerant ferromagnetism and, indeed, a celebrated theorem by Lieb rigorously establishes that the ground state of the repulsive Hubbard model on a bipartite lattice with an unequal number of sites in each sublattice must have nonzero spin S at half filling. Recently, there has been interest in Lieb geometries due to the possibility of topological insulator, nematic, and Bose-Einstein condensed (BEC) phases. In this paper, we extend the understanding of the attractive Hubbard model on the Lieb lattice by using determinant quantum Monte Carlo to study real space charge and pair correlation functions not addressed by the Lieb theorems. Specifically, our results show unusual charge and charge transfer signatures within the flat band, and a reduction in pairing order at ρ =2/3 and ρ =4/3, the points at which the flat band is first occupied and then completely filled. We compare our results to the case of flat bands in the Kagome lattice and demonstrate that the behavior observed in the two cases is rather different.

  2. Piecewise planar Möbius bands

    DEFF Research Database (Denmark)

    Gravesen, Jens


    t is shown that a closed polygon with an odd number of vertices is the median of exactly one piecewise planar cylinder and one piecewise planar Möbius band, intersecting each other orthogonally. A closed polygon with an even number of vertices is in the generic case neither the median...

  3. Radio Band Observations of Blazar Variability

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... Outbursts in total flux density and linear polarization in the optical-to-radio bands are attributed to shocks propagating within the jet spine, in part, based on limited modelling invoking transverse shocks; new radiative transfer simulations allowing for shocks at arbitrary angle to the flow direction confirm this ...

  4. The Band around a Convex Body (United States)

    Swanson, David


    We give elementary proofs of formulas for the area and perimeter of a planar convex body surrounded by a band of uniform thickness. The primary tool is a integral formula for the perimeter of a convex body which describes the perimeter in terms of the projections of the body onto lines in the plane.

  5. Atmospheric Solar Heating in Minor Absorption Bands (United States)

    Chou, Ming-Dah


    Solar radiation is the primary source of energy driving atmospheric and oceanic circulations. Concerned with the huge computing time required for computing radiative transfer in weather and climate models, solar heating in minor absorption bands has often been neglected. The individual contributions of these minor bands to the atmospheric heating is small, but collectively they are not negligible. The solar heating in minor bands includes the absorption due to water vapor in the photosynthetically active radiation (PAR) spectral region from 14284/cm to 25000/cm, the ozone absorption and Rayleigh scattering in the near infrared, as well as the O2 and CO2 absorption in a number of weak bands. Detailed high spectral- and angular-resolution calculations show that the total effect of these minor absorption is to enhance the atmospheric solar heating by approximately 10%. Depending upon the strength of the absorption and the overlapping among gaseous absorption, different approaches are applied to parameterize these minor absorption. The parameterizations are accurate and require little extra time for computing radiative fluxes. They have been efficiently implemented in the various atmospheric models at NASA/Goddard Space Flight Center, including cloud ensemble, mesoscale, and climate models.

  6. Ultrafast carotenoid band shifts: Experiment and theory

    NARCIS (Netherlands)

    Herek, J.L.; Wendling, M.; He, Z.; Polivka, T.; Garcia-Asua, G.; Cogdell, R.J.; Hunter, C.N.; van Grondelle, R.; Sundstrom, V.; Pullerits, T.


    The ultrafast carotenoid band shift upon excitation of nearby bacteriochlorophyll molecules was studied in three different light harvesting complexes from purple bacteria. The results were analyzed in terms of changes in local electric field of the carotenoids. Time dependent density functional

  7. Multi-Frequency Band Pyroelectric Sensors

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao


    Full Text Available A methodology is proposed for designing a multi-frequency band pyroelectric sensor which can detect subjects with various frequencies or velocities. A structure with dual pyroelectric layers, consisting of a thinner sputtered ZnO layer and a thicker aerosol ZnO layer, proved helpful in the development of the proposed sensor. The thinner sputtered ZnO layer with a small thermal capacity and a rapid response accomplishes a high-frequency sensing task, while the thicker aerosol ZnO layer with a large thermal capacity and a tardy response is responsible for low-frequency sensing tasks. A multi-frequency band pyroelectric sensor is successfully designed, analyzed and fabricated in the present study. The range of the multi-frequency sensing can be estimated by means of the proposed design and analysis to match the thicknesses of the sputtered and the aerosol ZnO layers. The fabricated multi-frequency band pyroelectric sensor with a 1 μm thick sputtered ZnO layer and a 20 μm thick aerosol ZnO layer can sense a frequency band from 4000 to 40,000 Hz without tardy response and low voltage responsivity.

  8. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)


    Mar 20, 2014 ... Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 4. Deformed ... Deformed structure; constrained Hartree–Fock; shell closure; rotational band; electromagnetic properties. ... Department of Physics, IIT Ropar, Rupnagar 140 001, India; Institute of Physics, Bhubaneswar 751 005, India ...

  9. S-Band Doppler Wave Radar System

    Directory of Open Access Journals (Sweden)

    Zezong Chen


    Full Text Available In this paper, a novel shore-based S-band microwave Doppler coherent wave radar (Microwave Ocean Remote SEnsor (MORSE is designed to improve wave measurements. Marine radars, which operate in the X band, have been widely used for ocean monitoring because of their low cost, small size and flexibility. However, because of the non-coherent measurements and strong absorption of X-band radio waves by rain, these radar systems suffer considerable performance loss in moist weather. Furthermore, frequent calibrations to modify the modulation transfer function are required. To overcome these shortcomings, MORSE, which operates in the S band, was developed by Wuhan University. Because of the coherent measurements of this sensor, it is able to measure the radial velocity of water particles via the Doppler effect. Then the relation between the velocity spectrum and wave height spectrum can be used to obtain the wave height spectra. Finally, wave parameters are estimated from the wave height spectra by the spectrum moment method. Comparisons between MORSE and Waverider MKIII are conducted in this study, and the results, including the non-directional wave height spectra, significant wave height and average wave period, are calculated and displayed. The correlation coefficient of the significant wave height is larger than 0.9, whereas that of the average wave period is approximately 0.4, demonstrating the effectiveness of MORSE for the continuous monitoring of ocean areas with high accuracy.

  10. Faraday Rotation and L Band Oceanographic Measurements

    DEFF Research Database (Denmark)

    Skou, Niels


    Spaceborne radiometric measurements of the L band brightness temperature over the oceans make it possible to estimate sea surface salinity. However, Faraday rotation in the ionosphere disturbs the signals and must be corrected. Two different ways of assessing the disturbance directly from the rad...

  11. 5 CFR 9701.212 - Bands. (United States)



  12. Development of X band antenna for ADEOS (United States)

    Ougi, Hirokazu; Kaneko, Kazuhisa; Enomoto, Hideaki

    In recent years use of space for earth observation has focused on environmental problems of the planet Earth, such as forest destruction, green house effects on climate, etc. Resource assessment from space has also fostered interest. For these purposes, Japan launched JERS-1 (Japanese Earth Resources Satellite-1) in early 1992 and is developing the ADEOS (Advanced Earth Observing Satellite) for launch in 1996. ADEOS is expected to contribute global observation data to help the international community characterize environmental changes. This paper describes an X band antenna designed for ADEOS. The radiation pattern of this antenna has been optimized for transmission of Earth observation data. This X band antenna consists of a primary radiator and a main reflector. The waveguide structure is fitted directly to the primary radiator for high power RF transmission, and the aluminum honeycomb sandwich CFRP (Carbon Fiber Reinforced Plastic) main reflector reduces weight. Thermal and structural design is based on the technological heritage of the JERS-1 X band antenna, and the beam shaping method is improved over the JERS-1 X band design.

  13. Managing varices: drugs, bands, and shunts. (United States)

    Opio, Christopher Kenneth; Garcia-Tsao, Guadalupe


    Drugs, bands, and shunts have all been used in the treatment of varices and variceal hemorrhage and have resulted in improved outcomes. However, the specific use of each of these therapies depends on the setting (primary or secondary prophylaxis, treatment of AVH) and on patient characteristics. The indications for each are summarized in Table 4.


    The development of a C band, all solid state radar front end utilizing high quality state-of-the-art ferrite devices, completely passive in nature... development of the circulator and limiter are discussed in detail. The circulator consists of ferrimagnetic disks placed at the center of a coplanar 90

  15. Statistical study of auroral omega bands

    Directory of Open Access Journals (Sweden)

    N. Partamies


    Full Text Available The presence of very few statistical studies on auroral omega bands motivated us to test-use a semi-automatic method for identifying large-scale undulations of the diffuse aurora boundary and to investigate their occurrence. Five identical all-sky cameras with overlapping fields of view provided data for 438 auroral omega-like structures over Fennoscandian Lapland from 1996 to 2007. The results from this set of omega band events agree remarkably well with previous observations of omega band occurrence in magnetic local time (MLT, lifetime, location between the region 1 and 2 field-aligned currents, as well as current density estimates. The average peak emission height of omega forms corresponds to the estimated precipitation energies of a few keV, which experienced no significant change during the events. Analysis of both local and global magnetic indices demonstrates that omega bands are observed during substorm expansion and recovery phases that are more intense than average substorm expansion and recovery phases in the same region. The omega occurrence with respect to the substorm expansion and recovery phases is in a very good agreement with an earlier observed distribution of fast earthward flows in the plasma sheet during expansion and recovery phases. These findings support the theory that omegas are produced by fast earthward flows and auroral streamers, despite the rarity of good conjugate observations.

  16. First Results of the TOPSAR C-Band / L-Band Interferometer: Calibration and Differential Penetration (United States)

    Rosen, Paul A.; Hensley, Scott


    The NASA/JPL TOPSAR instrument recently was extended from a single wavelength C-band dual aperture synthetic aperture radar (SAR) interferometer to include a second wavelength at the L-band. Adding the second wavelength invites comparison of wavelength-diverse effects in topographic mapping of surfaces, with the principal goal of understanding the penetration of the radar signals in vegetation canopies, and determining the inferred topographic height. A first analysis of these data was conducted at two sites. Elkhorn Slough near Monterey, California presented flat, vegetation free terrain required for calibrating the radar interferometer parameters. A second site stretching from San Jose to Santa Cruz, California, which is heavily vegetated, provided the first test case for wavelength diverse penetration studies. Preliminary results show that: (a) the interferometer calibration determined at Elkhorn Slough is extenable to Laurel Quad and gives confidence in the C- and L-band height measurements; (b) Clear differences were observed between the C- and L-band heights associated with vegetation, with the C-band derived topographic heights generally higher than those from L-band. The noise level in the L-band interferometer is presently the limiting factor in penetration studies.

  17. Band gaps induced by vacuum photons in closed semiconductor cavities


    Kibis, O. V.; Arnardottir, K. B.; Shelykh, I. A.


    We consider theoretically a closed (zero-dimensional) semiconductor microcavity where confined vacuum photonic mode is coupled to electrons in valence band of the semiconductor. It is shown that vacuum-induced virtual electron transitions between valence and conduction bands result in renormalization of electron energy spectrum. As a consequence, vacuum-induced band gaps appear within the valence band. Calculated values of the band gaps are of sub-meV scale, that makes this QED effect to be m...

  18. Investigation of trap properties in high-k/metal gate p-type metal-oxide-semiconductor field-effect-transistors with aluminum ion implantation using random telegraph noise analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Tsung-Hsien; Chang, Shoou-Jinn, E-mail:; Fang, Yean-Kuen; Huang, Po-Chin [Institute of Microelectronics and Department of Electrical Engineering, Advanced Optoelectronic Technology Center, Center for Micro/Nano Science and Technology, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (China); Lai, Chien-Ming; Hsu, Chia-Wei; Chen, Yi-Wen; Cheng, Osbert [Central R and D Division, United Microelectronics Corporation, Ltd., Tainan Science-Based Industrial Park, Tainan 74145, Taiwan (China); Wu, Chung-Yi; Wu, San-Lein [Department of Electronic Engineering, Cheng Shiu University, 840 Chengcing Road, Niaosong, Kaohsiung 833, Taiwan (China)


    In this study, the impact of aluminum ion implantation (Al I/I) on random telegraph noise (RTN) in high-k/metal gate (HK/MG) p-type metal-oxide-semiconductor field-effect-transistors (pMOSFETs) was investigated. The trap parameters of HK/MG pMOSFETs with Al I/I, such as trap energy level, capture time and emission time, activation energies for capture and emission, and trap location in the gate dielectric, were determined. The configuration coordinate diagram was also established. It was observed that the implanted Al could fill defects and form a thin Al{sub 2}O{sub 3} layer and thus increase the tunneling barrier height for holes. It was also observed that the trap position in the Al I/I samples was lower due to the Al I/I-induced dipole at the HfO{sub 2}/SiO{sub 2} interface.

  19. Generation of Palaeoproterozoic tonalites and associated high-K granites in southwestern Tanzania by partial melting of underplated mafic crust in an intracontinental setting: Constraints from geochemical and isotopic data (United States)

    Manya, Shukrani; Maboko, Makenya A. H.


    The southwestern part of the 2.0-1.8 Ga Palaeoproterozoic Usagaran Belt in the Njombe area of SW Tanzania is intruded by two types of synchronous granitic rocks with different chemical and petrological characteristics. The first type consists of hornblende-rich tonalites that have major element compositions similar to those of Archaean TTG but differ significantly in their trace element composition. The tonalites are spatially and closely associated with felsic, high-K, I-type granites, some of which are gneissic and/or aplitic. U-Pb zircon geochronology shows that the emplacement of tonalites at 1887 ± 11 Ma was largely contemporaneous with emplacement of high-K granitic gneisses at 1877 ± 15 Ma and aplitic granites at 1857 ± 19 Ma. The data also reveal the presence of Archaean crust of 2648 ± 25 Ma in the zircon cores of some samples in the otherwise Palaeoproterozoic terrane. The tonalites are characterized by MgO contents of 1.60-4.11 wt.% at a SiO2 range of 58.1-67.9 wt.%, the Mg# of 34-55, lower Sr contents (220-462 ppm) and less fractionated REE patterns (La/YbCN = 3.55-12.9) compared to Archaean TTG (Sr > 500 ppm, La/YbCN > 20). These features, coupled with the εNd (1887 Ma) values of + 0.37 to - 0.66 as well as the associated mafic enclaves are suggestive of derivation of the tonalites by low pressure (below the garnet stability) partial melting of a mantle-derived mafic underplate that was subsequently contaminated with small amounts of pre-existing igneous crustal rocks. The evolved nature of the high-K granites (MgO = 0.20-1.30 wt.%, SiO2 = 65.5-73.9 wt.%, Mg# = 25-42, εNd = - 3.20 to - 4.75) coupled with old TDM ages which are 200-1000 Ma older than their emplacement age requires a higher degree of assimilation of older crustal material by the magma derived from partial melting of the underplated mafic crust which was subsequently followed by crystal fractionation involving plagioclase, pyroxene and amphibole. The close spatial and temporal

  20. Band connectivity for topological quantum chemistry: Band structures as a graph theory problem (United States)

    Bradlyn, Barry; Elcoro, L.; Vergniory, M. G.; Cano, Jennifer; Wang, Zhijun; Felser, C.; Aroyo, M. I.; Bernevig, B. Andrei


    The conventional theory of solids is well suited to describing band structures locally near isolated points in momentum space, but struggles to capture the full, global picture necessary for understanding topological phenomena. In part of a recent paper [B. Bradlyn et al., Nature (London) 547, 298 (2017), 10.1038/nature23268], we have introduced the way to overcome this difficulty by formulating the problem of sewing together many disconnected local k .p band structures across the Brillouin zone in terms of graph theory. In this paper, we give the details of our full theoretical construction. We show that crystal symmetries strongly constrain the allowed connectivities of energy bands, and we employ graph theoretic techniques such as graph connectivity to enumerate all the solutions to these constraints. The tools of graph theory allow us to identify disconnected groups of bands in these solutions, and so identify topologically distinct insulating phases.

  1. Ku-band HTS filters with narrow and wide bands for space communications

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Kazunori [Fujitsu Laboratories Ltd., 4-1-1, Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa 211-8588 (Japan)]. E-mail:; Shigaki, Masafumi [Fujitsu Ltd., 4-1-1, Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa 211-8588 (Japan); Taira, Shin-ichi [Kashima Space Research Center, National Institute of Information and Communications Technology, 893-1, Hirai, Kashima-shi, Ibaraki 314-8501 (Japan)


    We report the designing and simulation results of the HTS band-pass filters for Ku band with different bandwidths of 0.08 and 0.5 GHz, in comparison with the same shape filters using normal conductors as the circuit conductors of the filter resonator. The examination results of the fabricated filter samples are compared with the filtering characteristics of S parameters. In the case of the narrower band, the simulation results of the planer-circuit-type filter which consists of resonators showed the filtering characteristics that strongly depend on the coupling coefficients and the resonant frequency of each resonator mutually. It is confirmed that the HTS planer circuit filters for Ku band exhibited unloaded Q with the volume of about 10 cm{sup 3} greater than that of the normal conductor with the same structure.

  2. Diagnosis and management of early gastric band slip after laparoscopic adjustable gastric banding

    Directory of Open Access Journals (Sweden)

    Mehmet Sertkaya


    Full Text Available Laparoscopic adjustable gastric banding (LAGB used to be a very popular bariatric procedure at a certain time for the treatment of obesity as it has many advantages and is associated with low morbidity and mortality rates. Complications are often late and are rarely seen by general surgeons due to the limited number of patients, and physicians should be aware of the symptoms. We present a case of a 40-year-old female patient who underwent LAGB and was admitted for a huge gastric pouch dilatation on postoperative day 5. She had a history of food consumption on the fourth day after surgery. She was diagnosed with early gastric band slippage (EGBS. The band was repositioned and gastrogastric sutures were placed to prevent reprolapse of the band. The EGBS is an immediate postoperative complication. Diagnosis of EGBS can be made with oral contrast X-ray studies, and surgical intervention is necessary.

  3. Design of Dual-Band Two-Branch-Line Couplers with Arbitrary Coupling Coefficients in Bands

    Directory of Open Access Journals (Sweden)

    I. Prudyus


    Full Text Available A new approach to design dual-band two-branch couplers with arbitrary coupling coefficients at two operating frequency bands is proposed in this article. The method is based on the usage of equivalent subcircuits input reactances of the even-mode and odd-mode excitations. The exact design formulas for three options of the dual-band coupler with different location and number of stubs are received. These formulas permit to obtain the different variants for each structure in order to select the physically realizable solution and can be used in broad range of frequency ratio and power division ratio. For verification, three different dual-band couplers, which are operating at 2.4/3.9 GHz with different coupling coefficients (one with 3/6 dB, and 10/3 dB two others are designed, simulated, fabricated and tested. The measured results are in good agreement with the simulated ones.

  4. First Principles Study of Band Structure and Band Gap Engineering in Graphene for Device Applications (United States)


    successfully to realise the full applications of graphene? What is the current status of the graphene based devices or Electronics ? How the graphene...adsorption of foreign molecules . The vacant sites are like trapping centers such that they have a high tendency to adsorb the atoms/ molecules such that...thermodynamically favorable. In this case there is no band gap opening, only bands shifting , for the doping of N and B individually [29]. We then tried co

  5. Microleakage of orthodontic band cement at the cement-enamel and cement-band interfaces. (United States)

    Uysal, Tancan; Ramoglu, Sabri Ilhan; Ertas, Huseyin; Ulker, Mustafa


    Our objective was to determine and compare microleakage patterns of conventional glass ionomer cement (GIC), resin modified GIC (RMGIC), and polyacid-modified composite for band cementation. Sixty freshly extracted third molars were randomly divided into 3 groups of 20 teeth each. Microetched molar bands in the 3 groups were cemented to enamel with one of three orthodontic cements: Ketac-Cem (3M ESPE, Gmbh, Seefeld, Germany), Multi-Cure (3M Unitek, Monrovia, Calif), and Transbond Plus (3M Unitek). A dye penetration method was used for microleakage evaluation. Microleakage was determined by a stereomicroscope for the cement-band and cement-enamel interfaces from both the buccal and lingual margins. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney U tests. The buccal sides had similar microleakage values compared with the lingual sides for the cement-enamel and cement-band interfaces with all cements. Statistical comparisons showed statistically significant differences among the band cements between both interfaces (P <0.001). When the cement systems were compared, conventional GIC showed the highest leakage scores between cement-band (median, 3.50 mm) and cement-enamel (median, 2.88 mm) interfaces. Teeth banded with RMGIC and modified composite showed similar microleakage scores, and both had less leakage (<1 mm) than conventional GIC. Conventional GIC is associated with more microleakage than RMGIC and modified composite at both the cement-band and cement-enamel interfaces. Copyright (c) 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  6. Strain effects on valence bands of wurtzite ZnO (United States)

    Qiao, LiPing; Chai, ChangChun; Jin, Zhao; Yang, YinTang; Ma, ZhenYang


    Based on the k.p theory of Luttinger-Kohn and Bir-Pikus, analytical E-k solutions for the valence band of strained wurtzite ZnO materials are obtained. Strain effects on valence band edges and hole effective masses in strained wurtzite ZnO materials are also discussed. In comparison with unstrained ZnO materials, apparent movement of valence band edges such as "light hole band", "heavy hole band" and "crystal splitting band" at Γ point is found in strained wurtzite ZnO materials. Moreover, effective masses of "light hole band", "heavy hole band" and "crystal splitting band" for strained wurtzite ZnO materials as the function of stress are given. The analytical results can provide a theoretical foundation for the understanding of physics of strained ZnO materials and its applications with the framework for an effective mass theory.

  7. Hardening of shear band in metallic glass. (United States)

    Wang, J G; Hu, Y C; Guan, P F; Song, K K; Wang, L; Wang, G; Pan, Y; Sarac, B; Eckert, J


    Strain hardening, originating from defects such as the dislocation, avails conventional metals of high engineering reliability in applications. However, the hardenability of metallic glass is a long-standing concern due to the lack of similar defects. In this work, we carefully examine the stress-strain relationship in three bulk monolithic metallic glasses. The results show that hardening is surely available in metallic glasses if the effective load-bearing area is considered instantly. The hardening is proposed to result from the remelting and ensuing solidification of the shear-band material under a hydrostatic pressure imposed by the normal stress during the shear banding event. This applied-pressure quenching densifies the metallic glass by discharging the free volume. On the other hand, as validated by molecular dynamics simulations, the pressure promotes the icosahedral short-range order. The densification and icosahedral clusters both contribute to the increase of the shear strength and therefore the hardening in metallic glasses.

  8. Analysis of Signal Attenuation in UHF Band

    Directory of Open Access Journals (Sweden)

    Libor Michalek


    Full Text Available This paper deals with signal attenuation in ultra-high-frequency bands caused by rain. We focus mainly on the effect of the rain on the radio waves propagation in the frequency band 2.1 GHz. Two exact approaches for investigating this dependency are used. In the first approach, we use the fitting probability density function for determination Rician distribution K-factor. In the second approach, we want to find more concrete rain-rate dependency with using linear regression. The results achieved in our long-term investigation clearly indicate that the strong impact of rain itself is a minor. So-called secondary rain impacts such as scattering of reflections from wet surfaces cause the main attenuation contribution.

  9. Design of an Electronic Chest-Band (United States)

    Atakan, R.; Acikgoz Tufan, H.; Baskan, H.; Eryuruk, S. H.; Akalin, N.; Kose, H.; Li, Y.; Kursun Bahadir, S.; Kalaoglu, F.


    In this study, an electronic chest strap prototype was designed for measuring fitness level, performance optimization, mobility and fall detection. Knitting technology is used for production by using highly elastic nylon yarn. In order to evaluate comfort performance of the garment, yarn strength and elongation, air permeability, moisture management and FAST tests (Fabric Assurance Fabric Testing) were carried out, respectively. After testing of textile part of the chest band, IMU sensors were integrated onto the garment by means of conductive yarns. Electrical conductivity of the circuit was also assessed at the end. Results indicated that the weight and the thickness of the product are relatively high for sports uses and it has a negative impact on comfort properties. However, it is highly stretchable and moisture management properties are still in acceptable values. From the perspective of possible application areas, developed smart chest band in this research could be used in sports facilities as well as health care applications for elderly and disabled people.

  10. Verification of L-band SAR calibration (United States)

    Larson, R. W.; Jackson, P. L.; Kasischke, E.


    Absolute calibration of a digital L-band SAR system to an accuracy of better than 3 dB has been verified. This was accomplished with a calibration signal generator that produces the phase history of a point target. This signal relates calibration values to various SAR data sets. Values of radar cross-section (RCS) of reference reflectors were obtained using a derived calibration relationship for the L-band channel on the ERIM/CCRS X-C-L SAR system. Calibrated RCS values were compared to known RCS values of each reference reflector for verification and to obtain an error estimate. The calibration was based on the radar response to 21 calibrated reference reflectors.

  11. High resolution color band pyrometer ratioing (United States)

    Bickler, Donald B. (Inventor); Henry, Paul K. (Inventor); LoGiurato, D. Daniel (Inventor)


    The sensing head of a two-color band ratioing pyrometer of a known type using a fiber optic cable to couple radiation to dual detector photodiodes is improved to have high spatial resolution by focusing the radiation received through an objective lens (i.e., by focusing the image of a target area) onto an opaque sheet spaced in front of the input end of the fiber optic cable. A two-mil hole in that sheet then passes radiation to the input end of the cable. The detector has two channels, one for each color band, with an electronic-chopper stabilized current amplifier as the input stage followed by an electronic-chopper stabilized voltage amplifier.

  12. Ictal EEG patterns in band heterotopia. (United States)

    Grant, Arthur C; Rho, Jong M


    Band heterotopia (BH) or "double cortex" syndrome is a neuronal migration disorder resulting in a diffuse band of subcortical grey matter and variable abnormality of the overlying cortex. Patients with BH have a spectrum of psychomotor delay and seizures. Associated epileptic syndromes and interictal EEG findings have been described, but ictal EEG patterns are lacking. We describe the clinical, interictal, and ictal EEG findings in two girls with BH and intractable seizures. Ictal EEG patterns correlated well with clinical seizure types, and did not have features unique to BH. Similarly, seizure behaviors and interictal EEG findings were typical of those seen in symptomatic generalized epilepsies. Despite evidence implicating the ectopic grey matter in seizure discharges, we conclude that seizure semiology and associated ictal EEG patterns in BH are no different from those seen in other causes of symptomatic generalized epilepsies.

  13. Ku band low noise parametric amplifier (United States)


    A low noise, K sub u-band, parametric amplifier (paramp) was developed. The unit is a spacecraft-qualifiable, prototype, parametric amplifier for eventual application in the shuttle orbiter. The amplifier was required to have a noise temperature of less than 150 K. A noise temperature of less than 120 K at a gain level of 17 db was achieved. A 3-db bandwidth in excess of 350 MHz was attained, while deviation from phase linearity of about + or - 1 degree over 50 MHz was achieved. The paramp operates within specification over an ambient temperature range of -5 C to +50 C. The performance requirements and the operation of the K sub u-band parametric amplifier system are described. The final test results are also given.

  14. Comparison of eigensolvers for symmetric band matrices. (United States)

    Moldaschl, Michael; Gansterer, Wilfried N


    We compare different algorithms for computing eigenvalues and eigenvectors of a symmetric band matrix across a wide range of synthetic test problems. Of particular interest is a comparison of state-of-the-art tridiagonalization-based methods as implemented in Lapack or Plasma on the one hand, and the block divide-and-conquer (BD&C) algorithm as well as the block twisted factorization (BTF) method on the other hand. The BD&C algorithm does not require tridiagonalization of the original band matrix at all, and the current version of the BTF method tridiagonalizes the original band matrix only for computing the eigenvalues. Avoiding the tridiagonalization process sidesteps the cost of backtransformation of the eigenvectors. Beyond that, we discovered another disadvantage of the backtransformation process for band matrices: In several scenarios, a lot of gradual underflow is observed in the (optional) accumulation of the transformation matrix and in the (obligatory) backtransformation step. According to the IEEE 754 standard for floating-point arithmetic, this implies many operations with subnormal (denormalized) numbers, which causes severe slowdowns compared to the other algorithms without backtransformation of the eigenvectors. We illustrate that in these cases the performance of existing methods from Lapack and Plasma reaches a competitive level only if subnormal numbers are disabled (and thus the IEEE standard is violated). Overall, our performance studies illustrate that if the problem size is large enough relative to the bandwidth, BD&C tends to achieve the highest performance of all methods if the spectrum to be computed is clustered. For test problems with well separated eigenvalues, the BTF method tends to become the fastest algorithm with growing problem size.

  15. First DENIS I-band extragalactic catalog


    Vauglin, I.; Paturel, G.; Borsenberger, J.; Fouqué, P.; Epchtein, N.; Kimeswenger, S.; Tiphène, D.; Lanoix, P.; Courtois, H. Di-Nella


    This paper presents the first I-band photometric catalog of the brightest galaxies extracted from the Deep Near Infrared Survey of the Southern Sky (DENIS) An automatic galaxy recognition program has been developed to build this provisional catalog. The method is based on a discriminating analysis. The most discriminant parameter to separate galaxies from stars is proved to be the peak intensity of an object divided by its array. Its efficiency is better than 99%. The nominal accuracy for gal...

  16. Large Aperture, Scanning, L-Band SAR (United States)

    Moussessian, Alina; DelCastillo, Linda; Bach, Vinh; Grando, Maurio; Quijano, Ubaldo; Smith, Phil; Zawadzki, Mark


    We have developed the first L-band membrane-based active phased array. The antenna is a 16x16 element patch array with dimensions of 2.3mx2.6m. The array uses membrane-compatible Transmit/Receive (T/R) modules for electronic beam steering. We will discuss the antenna design, the fabrication of this large array, the T/R module development, the signal distribution approach and the measured results of the array


    Energy Technology Data Exchange (ETDEWEB)



    The Sub-Picosecond Accelerator (SPA) at the Los Alamos National Laboratory is an L-band photoinjector. Using magnetic compression, the SPA routinely compresses 8 MeV, 1 nC per bunch electron beams from an initial temporal FWHM bunch length of 20 ps to less than 1 ps. In recent plasma wakefield accelerator experiments, we have compressed a 2 nC per bunch electron beam to an approximate temporal length of 1 ps.

  18. Cluster rotational bands in 11B

    Directory of Open Access Journals (Sweden)

    Danilov A.N.


    Full Text Available Differential cross-sections of 11B+α inelastic scattering at E(α =65 MeV leading to most of the known 11B states at excitation energies up to 14 MeV were measured [1]. The data analysis was done using Modified diffraction model (MDM [2] allowing determining radii of excited states. Radii of the states with excitation energies less than ∼ 7 MeV coincide with the radius of the ground state with an accuracy not less than 0.1 - 0.15 fm. This result is consistent with traditional view on shell structure of low-lying states in 11B. Most of the observed high-energy excited states are distributed among four rotational bands. Moments of inertia of band states are close to the moment of inertia of the Hoyle state of 12C. The calculated radii, related to these bands, are 0.7 - 1.0 fm larger than the radius of the ground state, and are close to the Hoyle state radius. These results are in agreement with existing predictions about various cluster structure of 11B at high excitation energies.

  19. On the persistence of adiabatic shear bands (United States)

    Boakye-Yiadom, S.; Bassim, M. N.; Al-Ameeri, S.


    It is generally agreed that the initiation and development of adiabatic shear bands (ASBs) are manifestations of damage in metallic materials subjected to high strain rates and large strains as those due to impact in a Hopkinson Bar system. Models for evolution of these bands have been described in the literature. One question that has not received attention is how persistent these bands are and whether their presence and effect can be reversed or eliminated by using a process of thermal (heat treatment) or thermo-mechanical treatment that would relieve the material from the high strain associated with ASBs and their role as precursors to crack initiation and subsequent failure. Since ASBs are more prevalent and more defined in BCC metals including steels, a study was conducted to investigate the best conditions of generating ASBs in a heat treatable steel, followed by determining the best conditions for heat treatment of specimens already damaged by the presence of ASBs in order to relieve the strains due to ASBs and restore the material to an apparent microstructure without the "scars" due to the previous presence of ASBs. It was found that heat treatment achieves the curing from ASBs. This presentation documents the process undertaken to achieve this objective.

  20. Topological transitions in multi-band superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Continentino, Mucio A., E-mail: [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150, Urca 22290-180, Rio de Janeiro, RJ (Brazil); Deus, Fernanda, E-mail: [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150, Urca 22290-180, Rio de Janeiro, RJ (Brazil); Padilha, Igor T., E-mail: [Universidade Federal do Amazonas, Campus Capital, 69077-070, Manaus, AM (Brazil); Caldas, Heron, E-mail: [Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, 36301-000, São João Del Rei, MG (Brazil)


    The search for Majorana fermions has been concentrated in topological insulators or superconductors. In general, the existence of these modes requires the presence of spin–orbit interactions and of an external magnetic field. The former implies in having systems with broken inversion symmetry, while the latter breaks time reversal invariance. In a recent paper, we have shown that a two-band metal with an attractive inter-band interaction has non-trivial superconducting properties, if the k-dependent hybridization is anti-symmetric in the wave-vector. This is the case, if the crystalline potential mixes states with different parities as for orbitals with angular momentum l and l+1. In this paper we take into account the effect of an external magnetic field, not considered in the previous investigation, in a two-band metal and show how it modifies the topological properties of its superconducting state. We also discuss the conditions for the appearance of Majorana fermions in this system.

  1. On the persistence of adiabatic shear bands

    Directory of Open Access Journals (Sweden)

    Bassim M.N.


    Full Text Available It is generally agreed that the initiation and development of adiabatic shear bands (ASBs are manifestations of damage in metallic materials subjected to high strain rates and large strains as those due to impact in a Hopkinson Bar system. Models for evolution of these bands have been described in the literature. One question that has not received attention is how persistent these bands are and whether their presence and effect can be reversed or eliminated by using a process of thermal (heat treatment or thermo-mechanical treatment that would relieve the material from the high strain associated with ASBs and their role as precursors to crack initiation and subsequent failure. Since ASBs are more prevalent and more defined in BCC metals including steels, a study was conducted to investigate the best conditions of generating ASBs in a heat treatable steel, followed by determining the best conditions for heat treatment of specimens already damaged by the presence of ASBs in order to relieve the strains due to ASBs and restore the material to an apparent microstructure without the “scars” due to the previous presence of ASBs. It was found that heat treatment achieves the curing from ASBs. This presentation documents the process undertaken to achieve this objective.

  2. Frequency Arrangement For 700 MHz Band

    Directory of Open Access Journals (Sweden)

    Ancans G.


    Full Text Available The 694-790 MHz (700 MHz band was allocated by the 2012 World Radiocommunication Conference (WRC-12 in ITU Region 1 (Europe included, to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT. At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15. In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.

  3. Spectral band selection for classification of soil organic matter content (United States)

    Henderson, Tracey L.; Szilagyi, Andrea; Baumgardner, Marion F.; Chen, Chih-Chien Thomas; Landgrebe, David A.


    This paper describes the spectral-band-selection (SBS) algorithm of Chen and Landgrebe (1987, 1988, and 1989) and uses the algorithm to classify the organic matter content in the earth's surface soil. The effectiveness of the algorithm was evaluated comparing the results of classification of the soil organic matter using SBS bands with those obtained using Landsat MSS bands and TM bands, showing that the algorithm was successful in finding important spectral bands for classification of organic matter content. Using the calculated bands, the probabilities of correct classification for climate-stratified data were found to range from 0.910 to 0.980.

  4. Dual band metamaterial perfect absorber based on artificial dielectric "molecules". (United States)

    Liu, Xiaoming; Lan, Chuwen; Li, Bo; Zhao, Qian; Zhou, Ji


    Dual band metamaterial perfect absorbers with two absorption bands are highly desirable because of their potential application areas such as detectors, transceiver system, and spectroscopic imagers. However, most of these dual band metamaterial absorbers proposed were based on resonances of metal patterns. Here, we numerically and experimentally demonstrate a dual band metamaterial perfect absorber composed of artificial dielectric "molecules" with high symmetry. The artificial dielectric "molecule" consists of four "atoms" of two different sizes corresponding to two absorption bands with near unity absorptivity. Numerical and experimental absorptivity verify that the dual-band metamaterial absorber is polarization insensitive and can operate in wide-angle incidence.

  5. The 450-band resolution G- and R-banded standard karyotype of the donkey (Equus asinus, 2n = 62). (United States)

    Di Meo, G P; Perucatti, A; Peretti, V; Incarnato, D; Ciotola, F; Liotta, L; Raudsepp, T; Di Berardino, D; Chowdhary, B; Iannuzzi, L


    Donkey chromosomes were earlier characterized separately by C-, G- and R-banding techniques. However, direct comparisons between G- and R-banding patterns have still not been carried out in this species. The present study reports this comparison at the 450-band level by using replication G- and R-banding patterns. Two sets of synchronized lymphocyte cultures were set up to obtain early (GBA+CBA-banding) and late (RBA-banding) BrdU incorporation. Slides were stained with acridine orange and observed under a fluorescence microscope. Reverse GBA+CBA- and RBA-banded karyotypes at the 450-band level were constructed. To verify G- and R-banding patterns in some acrocentric chromosomes, sequential GBA+CBA/Ag-NORs and RBA/Ag-NORs were also performed. The results of CBA-banding patterns obtained in 12 animals from 2 breeds showed a pronounced polymorphism of heterochromatin, especially in EAS1q-prox. Ideogrammatic representations of G- and R-banded karyotypes were constructed using only one common G- and R-banding nomenclature. In the present study both G- and R-banding patterns and relative ideograms are presented as standard karyotype for this species at the 450-band level. (c) 2009 S. Karger AG, Basel.

  6. Comparing fungal band formulations for Asian longhorned beetle biological control. (United States)

    Ugine, Todd A; Jenkins, Nina E; Gardescu, Sana; Hajek, Ann E


    Experiments were conducted with the fungal entomopathogen Metarhizium brunneum to determine the feasibility of using agar-based fungal bands versus two new types of oil-formulated fungal bands for Asian longhorned beetle management. We investigated conidial retention and survival on three types of bands attached to trees in New York and Pennsylvania: standard polyester fiber agar-based bands containing fungal cultures, and two types of bands made by soaking either polyester fiber or jute burlap with oil-conidia suspensions. Fungal band formulation did not affect the number or viability of conidia on bands over the 2-month test period, although percentage conidial viability decreased significantly with time for all band types. In a laboratory experiment testing the effect of the three band formulations on conidial acquisition and beetle survival, traditional agar-based fungal bands delivered the most conidia to adult beetles and killed higher percentages of beetles significantly faster (median survival time of 27d) than the two oil-formulated materials (36-37d). We also tested the effect of band formulation on conidial acquisition by adult beetles kept individually in cages with a single band for 24h, and significantly more conidia (3-7times) were acquired by beetles from agar-based bands compared to the two oil formulations. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Jorge A. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Kinoshita, Angela [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Leonor, Sergio J. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Belmonte, Gustavo C. [Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Baffa, Oswaldo, E-mail: [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)


    In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

  8. Relating the defect band gap and the density functional band gap (United States)

    Schultz, Peter; Edwards, Arthur


    Density functional theory (DFT) is an important tool to probe the physics of materials. The Kohn-Sham (KS) gap in DFT is typically (much) smaller than the observed band gap for materials in nature, the infamous ``band gap problem.'' Accurate prediction of defect energy levels is often claimed to be a casualty--the band gap defines the energy scale for defect levels. By applying rigorous control of boundary conditions in size-converged supercell calculations, however, we compute defect levels in Si and GaAs with accuracies of ~0.1 eV, across the full gap, unhampered by a band gap problem. Using GaAs as a theoretical laboratory, we show that the defect band gap--the span of computed defect levels--is insensitive to variations in the KS gap (with functional and pseudopotential), these KS gaps ranging from 0.1 to 1.1 eV. The defect gap matches the experimental 1.52 eV gap. The computed defect gaps for several other III-V, II-VI, I-VII, and other compounds also agree with the experimental gap, and show no correlation with the KS gap. Where, then, is the band gap problem? This talk presents these results, discusses why the defect gap and the KS gap are distinct, implying that current understanding of what the ``band gap problem'' means--and how to ``fix'' it--need to be rethought. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  9. On Optimizing an Archibald Rubber-Band Heat Engine. (United States)

    Mullen, J. G.; And Others


    Discusses the criteria and procedure for optimizing the performance of Archibald rubber-band heat engines by using the appropriate choice of dimensions, minimizing frictional torque, maximizing torque and balancing the rubber band system. (GA)

  10. Central Flyway Duck Banding project : Annual progress report 2000 (United States)

    US Fish and Wildlife Service, Department of the Interior — The Central Flyway Council (CFC) initiated a six year duck banding program in 1996 with emphasis on mallard banding in North Dakota, South Dakota, Montana, and...

  11. Living with a Gastric Band: A Qualitative Study

    National Research Council Canada - National Science Library

    Pfeil, Michael; Crozier, Kenda; Pulford, Amanda; Ferguson, Yasmin; Mahon, David; Lewis, Michael


    Gastric banding is an established and effective form of weightloss surgery. Semi-structured interviews explored the experiences of gastric banding of twenty purposively recruited patients one year after surgery...

  12. Ninigret National Wildlife Refuge 2009 Fall Banding Summary (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bird banding results at Ninigret National Wildlife Refuge during the fall of 2009. The Ninigret banding station opened nets on 21 August and...

  13. Ninigret National Wildlife Refuge 2012 Fall Banding Summary (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bird banding results at Ninigret National Wildlife Refuge during the fall of 2012. The Ninigret banding station opened nets on 4 September and...

  14. Ninigret National Wildlife Refuge 2010 Fall Banding Summary (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bird banding results at Ninigret National Wildlife Refuge during the fall of 2010. The Ninigret banding station opened nets on 26 August and...

  15. Ninigret National Wildlife Refuge 2011 Fall Banding Summary (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bird banding results at Ninigret National Wildlife Refuge during the fall of 2011. The Ninigret banding station opened nets on 19 August and...

  16. Ninigret National Wildlife Refuge 2008 Fall Banding Summary (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bird banding results at Ninigret National Wildlife Refuge during the fall of 2008. The Ninigret banding station opened nets on 29 August and...

  17. Fitness band accuracy in older community dwelling adults. (United States)

    Madigan, Elizabeth A


    Fitness bands are widely available and assist with tracking the number of steps taken. However, for older people with slow gaits, shorter step widths and/or use of ambulatory devices, the accuracy of fitness bands for step counting has not been well studied. Using four commercially available fitness bands (Garmin Vivofit2™, Fitbit Flex™, Up3™ and Microsoft Band™), we studied 30 older people with varying ambulatory abilities. We videotaped participants walking and compared the videotaped step count with the fitness band counts. Only 5 of the 30 participants had accurate readings within a ±20 percent accuracy for all four bands. There was no relationship between the step speed and accuracy of the fitness bands. Participants using walkers and walking sticks had none of the bands that met the ±20 percent accuracy. Canes were more variable with accuracy. Fitness band manufacturers may need to tune their algorithms for use by older people.

  18. Vascular Adaptations to Transverse Aortic Banding in Mice

    National Research Council Canada - National Science Library

    Hartley, Craig


    .... Results showed that mean aortic, mitral, and carotid velocities were similar in sham and banded mice, but peak RCA/LCA velocities were much higher in banded mice and were highly correlated to HW...

  19. Modeling direct band-to-band tunneling: From bulk to quantum-confined semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Nuñez, H.; Ziegler, A.; Luisier, M.; Schenk, A. [Integrated Systems Laboratory ETH Zürich, Gloriastrasse 35, 8092 Zürich (Switzerland)


    A rigorous framework to study direct band-to-band tunneling (BTBT) in homo- and hetero-junction semiconductor nanodevices is introduced. An interaction Hamiltonian coupling conduction and valence bands (CVBs) is derived using a multiband envelope method. A general form of the BTBT probability is then obtained from the linear response to the “CVBs interaction” that drives the system out of equilibrium. Simple expressions in terms of the one-electron spectral function are developed to compute the BTBT current in two- and three-dimensional semiconductor structures. Additionally, a two-band envelope equation based on the Flietner model of imaginary dispersion is proposed for the same purpose. In order to characterize their accuracy and differences, both approaches are compared with full-band, atomistic quantum transport simulations of Ge, InAs, and InAs-Si Esaki diodes. As another numerical application, the BTBT current in InAs-Si nanowire tunnel field-effect transistors is computed. It is found that both approaches agree with high accuracy. The first one is considerably easier to conceive and could be implemented straightforwardly in existing quantum transport tools based on the effective mass approximation to account for BTBT in nanodevices.

  20. Precipitation estimation using L-band and C-band soil moisture retrievals (United States)

    Koster, Randal D.; Brocca, Luca; Crow, Wade T.; Burgin, Mariko S.; De Lannoy, Gabrielle J. M.


    An established methodology for estimating precipitation amounts from satellite-based soil moisture retrievals is applied to L-band products from the Soil Moisture Active Passive (SMAP) and Soil Moisture and Ocean Salinity (SMOS) satellite missions and to a C-band product from the Advanced Scatterometer (ASCAT) mission. The precipitation estimates so obtained are evaluated against in situ (gauge-based) precipitation observations from across the globe. The precipitation estimation skill achieved using the L-band SMAP and SMOS data sets is higher than that obtained with the C-band product, as might be expected given that L-band is sensitive to a thicker layer of soil and thereby provides more information on the response of soil moisture to precipitation. The square of the correlation coefficient between the SMAP-based precipitation estimates and the observations (for aggregations to ˜100 km and 5 days) is on average about 0.6 in areas of high rain gauge density. Satellite missions specifically designed to monitor soil moisture thus do provide significant information on precipitation variability, information that could contribute to efforts in global precipitation estimation.

  1. Inter-band optoelectronic properties in quantum dot structure of low band gap III-V semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Anup, E-mail: [Electronics and Communication Engineering Department, Kalyani Government Engineering College, Kalyani 741235 (India); Maiti, Biswajit [Physics Department, Kalyani Government Engineering College, Kalyani 741235 (India); Chanda, Debasree [Department of Engineering and Technological Studies, Kalyani University, Kalyani 741235 (India)


    A generalized theory is developed to study inter-band optical absorption coefficient (IOAC) and material gain (MG) in quantum dot structures of narrow gap III-V compound semiconductor considering the wave-vector (k{sup →}) dependence of the optical transition matrix element. The band structures of these low band gap semiconducting materials with sufficiently separated split-off valance band are frequently described by the three energy band model of Kane. This has been adopted for analysis of the IOAC and MG taking InAs, InSb, Hg{sub 1−x}Cd{sub x}Te, and In{sub 1−x}Ga{sub x}As{sub y}P{sub 1−y} lattice matched to InP, as example of III–V compound semiconductors, having varied split-off energy band compared to their bulk band gap energy. It has been found that magnitude of the IOAC for quantum dots increases with increasing incident photon energy and the lines of absorption are more closely spaced in the three band model of Kane than those with parabolic energy band approximations reflecting the direct the influence of energy band parameters. The results show a significant deviation to the MG spectrum of narrow-gap materials having band nonparabolicity compared to the parabolic band model approximations. The results reflect the important role of valence band split-off energies in these narrow gap semiconductors.

  2. Water Quality Models with Different Functions of Exotech Radiometer Bands


    Rao, K. R.; Krishnan, R.; Chakraborty, A. K.; Deekshatulu, B. L.


    Surveillance of water quality by remote sensing technique can be pursued with advantage. An attempt has been made in this paper to obtain regional models of water quality of inland tanks and lakes. Stepwise multiple linear regression analysis between water quality parameters and several functions of Exotech radiometer band reflectance values, namely, bands alone, bands and their ratios, and, bands and their products are evaluated with respect to performance of the regression parameters. It is...

  3. Dual band metamaterial perfect absorber based on artificial dielectric ?molecules?


    Xiaoming Liu; Chuwen Lan; Bo Li; Qian Zhao; Ji Zhou


    Dual band metamaterial perfect absorbers with two absorption bands are highly desirable because of their potential application areas such as detectors, transceiver system, and spectroscopic imagers. However, most of these dual band metamaterial absorbers proposed were based on resonances of metal patterns. Here, we numerically and experimentally demonstrate a dual band metamaterial perfect absorber composed of artificial dielectric ?molecules? with high symmetry. The artificial dielectric ?mo...

  4. Effects of neck bands on survival of greater snow geese (United States)

    Menu, S.; Hestbeck, J.B.; Gauthier, G.; Reed, A.


    Neck bands are a widely used marker in goose research. However, few studies have investigated a possible negative effect of this marker on survival. We tested the effect of neck bands on the survival of adult female greater snow geese (Chen caerulescens atlantica) by marking birds with either a neck band and a metal leg band or a leg band only on Bylot Island (Nunavut, formerly included in the Northwest Territories, Canada) from 1990 to 1996. Annual survival was estimated using leg-band recoveries in fall and winter and using neck-band sightings in spring and fall. Recapture rates were estimated using summer recaptures. Using recovery data, the selected model yielded a survival similar for the neck-banded and leg-banded only birds (S = 0.845 ?? 0.070 vs. S = 0.811 ?? 0.107). The hypothesis of equality of survival between the 2 groups was easily accepted under most constraints imposed on survival or recovery rates. However, failure to account for a different direct recovery rate for neck-banded birds would lead us to incorrectly conclude a possible negative effect of neck bands on survival. Using sighting data, mean annual survival of neck-banded birds was independently estimated at 0.833 ?? 0.057, a value very similar to that estimated with band-recovery analysis. Raw recapture rates during summer were significantly lower for neck-banded birds compared to those marked with leg bands only (4.6% vs. 12.1%), but in this analysis, survival, site fidelity, reproductive status, and recapture rates were confounded. We conclude that neck bands did not affect survival of greater snow geese, but could possibly affect other demographic traits such as breeding propensity and emigration.

  5. An Interpretation of Banded Magnetospheric Radio Emissions (United States)

    Benson, Robert F.; Osherovich, V. A.; Fainberg, J.; Vinas, A. F.; Ruppert, D. R.; Vondrak, Richard R. (Technical Monitor)


    Recently-published Active Magnetospheric Particle Tracer Explorer/Isothermal Remanent Magnetization (AMPTE/IRM) banded magnetospheric emissions, commonly referred to as '(n + 1/2)f(sub ce)' emissions where f(sub ce) is the electron gyrofrequency, are analyzed by treating them as analogous to sounder-stimulated ionospheric emissions. We show that both individual AMPTE/IRM spectra of magnetospheric banded emissions, and a statistically-derived spectra observed over the two-year lifetime of the mission, can be interpreted in a self-consistent manner. The analysis, which predicts all spectral peaks within 4% of the observed peaks, interprets the higher-frequency emissions as due to low group-velocity Bernstein-mode waves and the lower-frequency emissions as eigen modes of cylindrical-electromagnetic-plasma-oscillations. The demarcation between these two classes of emissions is the electron plasma frequency f(sub pe), where an emission is often observed. This f(sub pe), emission is not necessarily the strongest. None of the observed banded emissions were attributed to the upper-hybrid frequency. We present Alouette-2 and ISIS-1 plasma-resonance data, and model electron temperature (T(sub e)) values, to support the argument that the frequency-spectrum of ionospheric sounder-stimulated emissions is not strongly temperature dependent and thus that the interpretation of these emissions in the ionosphere is relevant to other plasmas (such as the magnetosphere) where N(sub e) and T(sub e) can be quite different but where the ratio f(sub pe)/f(sub ce) is identical.

  6. 76 FR 51978 - Unlicensed Operation in the TV Broadcast Bands (United States)


    ... COMMISSION Unlicensed Operation in the TV Broadcast Bands AGENCY: Federal Communications Commission. ACTION... Microsoft Corporation as TV bands device database administrators. The TV bands databases will be used by... of unlicensed broadband wireless devices in the TV spectrum. FOR FURTHER INFORMATION CONTACT: Hugh L...

  7. A Theoretical Structure of High School Concert Band Performance (United States)

    Bergee, Martin J.


    This study used exploratory (EFA) and confirmatory factor analysis (CFA) to verify a theoretical structure for high school concert band performance and to test that structure for viability, generality, and invariance. A total of 101 university students enrolled in two different bands rated two high school band performances (a "first"…

  8. Band-Structure of Thallium by the LMTO Method

    DEFF Research Database (Denmark)

    Holtham, P. M.; Jan, J. P.; Skriver, Hans Lomholt


    The relativistic band structure of thallium has been calculated using the linear muffin-tin orbital (LMTO) method. The positions and extents of the bands were found to follow the Wigner-Seitz rule approximately, and the origin of the dispersion of the bands was established from the canonical s...

  9. Assessment of multipath and shadowing effects on UHF band in ...

    African Journals Online (AJOL)

    Ultra-high frequency (UHF) bands are radio frequencies in the range of 300 MHz and 3 GHz. These bands are used for television broadcasting, mobile cellular systems, Wi-Fi, satellite communications and many others. Effective communication link in the UHF band requires direct line of sight between the transmitters and ...

  10. Centromeric banding pattern of mitotic chromosomes in Vigna vexillata

    African Journals Online (AJOL)

    Vigna vexillata chromosome characterization was carried out using the Leishman C- banding technique. The results showed that the chromosomes mostly exhibited bands at both the centromeric and telomeric regions. These bands will serve, as a valuable marker for the identification of the chromosomes. Chromosomes 2 ...

  11. Excitation of Banded Whistler Waves in the Magnetosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gary, S. Peter [Los Alamos National Laboratory; Liu, Kaijun [Los Alamos National Laboratory; Winske, Dan [Los Alamos National Laboratory


    Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.

  12. A prospective study of iliotibial band strain in runners. (United States)

    Hamill, Joseph; Miller, Ross; Noehren, Brian; Davis, Irene


    Iliotibial band syndrome is the leading cause of lateral knee pain in runners. It is thought that pain develops from strain on the iliotibial band due to friction of the iliotibial band sliding over the lateral femoral epicondyle. The purpose of this study was to investigate mechanical strain in the iliotibial band as a possible causative factor in the development of iliotibial band syndrome. From a large prospective study, female runners who incurred iliotibial band syndrome during the study were compared to a control group who incurred no injuries. Strain, strain rate and duration of impingement were determined from a musculoskeletal model of the lower extremity. The results indicated that the iliotibial band syndrome subjects exhibited greater strain throughout the support period, but particularly at midsupport compared to the control group. Strain rate was significantly greater in the iliotibial band syndrome group compared to the control group and was greater in the involved limb of the iliotibial band syndrome group compared to their contralateral limb. However, there were no differences in the duration of impingement between the groups. This study indicates that a major factor in the development of iliotibial band syndrome is strain rate. Therefore, we suggest that strain rate, rather than the magnitude of strain, may be a causative factor in developing iliotibial band syndrome. The effect size (>0.5) indicated that strain rate may be biologically significant in the etiology of iliotibial band syndrome.

  13. Microbial control of Asian longhorned beetles - what are fungal bands? (United States)

    Ann E. Hajek; Thomas Dubois; Jennifer Lund; Ryan Shanley; Leah Bauer; Michael Smith; Peng Fan; Huang Bo; Hu Jiafu; Zengzhi Li


    In Japan, the entomopathogenic fungus Beauveria brongniartii is grown in nonwoven fiber bands that are placed around trunks of orchard trees for control of numerous cerambycid pests, including Anoplophora chinensis (= A. malasiaca). The Japanese company producing bands, Nitto Denko in Osaka, markets bands...

  14. Broad-band semiconductor optical amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Ding Ying [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)]. E-mail:; Kan Qiang [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Wang Junling [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Pan Jiaoqing [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Zhou Fan [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Chen Weixi [School of Physics, Peking University, Beijing 100871 (China); Wang Wei [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)


    Broad-band semiconductor optical amplifiers (SOAs) with different thicknesses and thin bulk tensile-strained active layers were fabricated and studied. Amplified spontaneous emission (ASE) spectra and gain spectra of SOAs were measured and analyzed at different CW biases. A maximal 3 dB ASE bandwidth of 136 nm ranging from 1480 to 1616 nm, and a 3 dB optical amplifier gain bandwidth of about 90 nm ranging from 1510 to 1600 nm, were obtained for the very thin bulk active SOA. Other SOAs characteristics such as saturation output power and polarization sensitivity were measured and compared.

  15. Chiral bands in {sup 105}Rh

    Energy Technology Data Exchange (ETDEWEB)

    Alcantara-Nunez, J.A.; Oliveira, J.R.B.; Cybulska, E.W.; Medina, N.H.; Rao, M.N.; Ribas, R.V.; Rizzutto, M.A.; Seale, W.A.; Falla-Sotelo, F.; Wiedemann, K.T. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Dimitrov, V.I.; Frauendorf, S. [University of Notre Dame, Notre Dame, IN (United States). Dept. of Physics; Research Center Rossendorf, Dresden (Germany). Institute for Nuclear and Hadronic Physics


    The {sup 105}Rh nucleus has been studied by in-beam {gamma} spectroscopy with the heavy-ion fusion-evaporation reaction {sup 100}Mo({sup 11}B, {alpha}2n{gamma}) at 43 MeV. A rich variety of structures was observed at high and low spin, using {gamma}-{gamma}-t and {gamma}-{gamma}-particle coincidences and directional correlation ratios. Four magnetic dipole bands have also been observed at high spin. Two of them are nearly degenerate in excitation energy and could be chiral partners, as predicted by Tilted Axis Cranking calculations. (author)

  16. The end of the unique myocardial band

    DEFF Research Database (Denmark)

    MacIver, David H; Partridge, John B; Agger, Peter


    Two of the leading concepts of mural ventricular architecture are the unique myocardial band and the myocardial mesh model. We have described, in an accompanying article published in this journal, how the anatomical, histological and high-resolution computed tomographic studies strongly favour...... the latter concept. We now extend the argument to describe the linkage between mural architecture and ventricular function in both health and disease. We show that clinical imaging by echocardiography and magnetic resonance imaging, and electrophysiological studies, all support the myocardial mesh model. We...

  17. Robust MPEG Watermarking in DWT Four Bands

    Directory of Open Access Journals (Sweden)

    E. Elbaşı


    Full Text Available In this paper, we generalize an idea in a recent paper that embeds a binary pattern in the form of a binary image in the wavelet domain for images. Our generalization includes all four bands (LL, LH, HL and HH in the DWT for MPEG video sequences. We tested the proposed algorithm against twelve attacks. Embedding the watermark in lower frequencies is robust to one group of attacks, and embedding the watermark in higher frequencies is robust to another group of attacks.

  18. Preserved episodic memory in subcortical band heterotopia. (United States)

    Janzen, Laura; Sherman, Elisabeth; Langfitt, John; Berg, Michel; Connolly, Mary


    Neuropsychological profiles of four patients with subcortical band heterotopia (SBH) are presented to delineate further the phenotype of this disorder. Standardized, norm-referenced measures of cognitive functioning, including intelligence, processing speed, attention, language, visuomotor skills, memory, and fine motor ability were administered to four patients with magnetic resonance imaging evidence of SBH. Despite intellectual impairment and other severe cognitive deficits, all four patients displayed relatively intact episodic memory. This selective sparing of memory functions has not been previously reported in individuals with SBH and suggests that doublecortin does not play a role in the development of memory systems in the mesial temporal region, which tend to be spared in SBH.

  19. L-band radar scattering from grass (United States)

    Chauhan, N.; O'Neill, P.; Le Vine, D.; Lang, R.; Khadr, N.


    A radar system based on a network analyzer has been developed to study the backscatter from vegetation. The radar is operated at L-band. Radar measurements of a grass field were made in 1991. The radar returns from the grass were measured at three incidence angles. Ground truth and canopy parameters such as blade and stem dimensions, moisture content of the grass and the soil, and blade and stem density, were measured. These parameters are used in a distorted Born approximation model to compute the backscatter coefficients from the grass layer. The model results are compared with the radar data.

  20. Narrow-Band Excitation of Hysteretic Systems

    Directory of Open Access Journals (Sweden)

    W.Q. Zhu


    Full Text Available The stationary response of smooth and bilinear hysteretic systems to narrow-band random excitations is investigated by using the quasistatic method and digital simulation. It is shown that the response is qualitatively different in different ranges of values of the ratio of the excitation central frequency to the natural frequency of the system. In the resonant zone, the response is essentially non-Gaussian. For bilinear hysteretic systems with strong yielding, stochastic jumps may occur for a range of values of the ratio between nonresonant and resonant zones.

  1. Design of coplanar waveguide band-pass filter for S-band application

    Directory of Open Access Journals (Sweden)

    Pratik Mondal


    Full Text Available Coplanar waveguide (CPW has a huge demand for designing band-pass filter (BPF. In this study, the filter designed by open-ended CPW series stub which acts as a resonant circuit thus giving a band-pass response. As the number of open stub discontinuity is increased, the frequency response and roll-off rate of the proposed BPF has improved gradually. Electromagnetic simulated and measured results show a very good agreement with each other. The proposed filter is designed to obtain a frequency range of 1.97–4 GHz (S-band having rising edge and falling edge selectivities of 35.9 and 45.7 dB/GHz, respectively.

  2. Valence band energy spectrum of HgTe quantum wells with an inverted band structure (United States)

    Minkov, G. M.; Aleshkin, V. Ya.; Rut, O. E.; Sherstobitov, A. A.; Germanenko, A. V.; Dvoretski, S. A.; Mikhailov, N. N.


    The energy spectrum of the valence band in HgTe /CdxHg1 -xTe quantum wells of a width (8 -20 ) nm has been studied experimentally by magnetotransport effects and theoretically in the framework of a four-band k P method. Comparison of the Hall density with the density found from a period of the Shubnikov-de Haas (SdH) oscillations clearly shows that the degeneracy of states of the top of the valence band is equal to 2 at the hole density p SdH oscillations shows that mh is equal to (0.25 ±0.02 ) m0 and weakly increases with the hole density. Such a value of mh and its dependence on the hole density are in a good agreement with the calculated effective mass.

  3. Color composite C-band and L-band image of Kilauea volcanoe on Hawaii (United States)


    This color composite C-band and L-band image of the Kilauea volcano on the Big Island of Hawaii was acuired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperature Radar (SIR-C/X-SAR) flying on the Space Shuttle Endeavour. The city of Hilo can be seen at the top. The image shows the different types of lava flows around the crater Pu'u O'o. Ash deposits which erupted in 1790 from the summit of Kilauea volcano show up as dark in this image, and fine details associated with lava flows which erupted in 1919 and 1974 can be seen to the south of the summit in an area called the Ka'u Desert. Other historic lava flows can also be seen. Highway 11 is the linear feature running from Hilo to the Kilauea volcano. The Jet Propulsion Laboratory alternative photo number is P-43918.

  4. Four-band Hamiltonian for fast calculations in intermediate-band solar cells (United States)

    Luque, Antonio; Panchak, Aleksandr; Vlasov, Alexey; Martí, Antonio; Andreev, Viacheslav


    The 8-dimensional Luttinger-Kohn-Pikus-Bir Hamiltonian matrix may be made up of four 4-dimensional blocks. A 4-band Hamiltonian is presented, obtained from making the non-diagonal blocks zero. The parameters of the new Hamiltonian are adjusted to fit the calculated effective masses and strained QD bandgap with the measured ones. The 4-dimensional Hamiltonian thus obtained agrees well with measured quantum efficiency of a quantum dot intermediate band solar cell and the full absorption spectrum can be calculated in about two hours using Mathematica© and a notebook. This is a hundred times faster than with the commonly-used 8-band Hamiltonian and is considered suitable for helping design engineers in the development of nanostructured solar cells.

  5. X-Band to W-Band Doppler Radar Using Reconfigurable RF T/R MMIC Series Project (United States)

    National Aeronautics and Space Administration — During Phase I, TLC will demonstrate and deliver a remote mixed-mode adjustable X-band to W-band transceiver chip that can perform well as a FMCW, super-heterodyne...

  6. X-Band to W-Band Doppler Radar Using Reconfigurable RF T/R MMIC Series Project (United States)

    National Aeronautics and Space Administration — TLC demonstrated a high performance remote Doppler Radar adjustable X-band to W-band transceiver chip that can perform well as a FMCW, super-heterodyne or pulse...

  7. Simulation of radar backscattering from snowpack at X-band and Ku-band (United States)

    Gay, Michel; Phan, Xuan-Vu; Ferro-Famil, Laurent


    This paper presents a multilayer snowpack electromagnetic backscattering model, based on Dense Media Radiative Transfer (DMRT). This model is capable of simulating the interaction of electromagnetic wave (EMW) at X-band and Ku-band frequencies with multilayer snowpack. The air-snow interface and snow-ground backscattering components are calculated using the Integral Equation Model (IEM) by [1], whereas the volume backscattering component is calculated based on the solution of Vector Radiative Transfer (VRT) equation at order 1. Case study has been carried out using measurement data from NoSREx project [2], which include SnowScat data in X-band and Ku-band, TerraSAR-X acquisitions and snowpack stratigraphic in-situ measurements. The results of model simulations show good agreement with the radar observations, and therefore allow the DMRT model to be used in various applications, such as data assimilation [3]. [1] A.K. Fung and K.S. Chen, "An update on the iem surface backscattering model," Geoscience and Remote Sensing Letters, IEEE, vol. 1, no. 2, pp. 75 - 77, april 2004. [2] J. Lemmetyinen, A. Kontu, J. Pulliainen, A. Wiesmann, C. Werner, T. Nagler, H. Rott, and M. Heidinger, "Technical assistance for the deployment of an x- to ku-band scatterometer during the nosrex ii experiment," Final Report, ESA ESTEC Contract No. 22671/09/NL/JA., 2011. [3] X. V. Phan, L. Ferro-Famil, M. Gay, Y. Durand, M. Dumont, S. Morin, S. Allain, G. D'Urso, and A. Girard, "3d-var multilayer assimilation of x-band sar data into a detailed snowpack model," The Cryosphere Discussions, vol. 7, no. 5, pp. 4881-4912, 2013.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  9. High-k 3D-barium titanate foam/phenolphthalein poly(ether sulfone)/cyanate ester composites with frequency-stable dielectric properties and extremely low dielectric loss under reduced concentration of ceramics (United States)

    Zheng, Longhui; Yuan, Li; Guan, Qingbao; Liang, Guozheng; Gu, Aijuan


    Higher dielectric constant, lower dielectric loss and better frequency stability have been the developing trends for high dielectric constant (high-k) materials. Herein, new composites have been developed through building unique structure by using hyperbranched polysiloxane modified 3D-barium titanate foam (BTF) (BTF@HSi) as the functional fillers and phenolphthalein poly(ether sulfone) (cPES)/cyanate ester (CE) blend as the resin matrix. For BTF@HSi/cPES/CE composite with 34.1 vol% BTF, its dielectric constant at 100 Hz is as high as 162 and dielectric loss is only 0.007; moreover, the dielectric properties of BTF@HSi/cPES/CE composites exhibit excellent frequency stability. To reveal the mechanism behind these attractive performances of BTF@HSi/cPES/CE composites, three kinds of composites (BTF/CE, BTF/cPES/CE, BTF@HSi/CE) were prepared, their structure and integrated performances were intensively investigated and compared with those of BTF@HSi/cPES/CE composites. Results show that the surface modification of BTF is good for preparing composites with improved thermal stability; while introducing flexible cPES to CE is beneficial to fabricate composites with good quality through effectively blocking cracks caused by the stress concentration, and then endowing the composites with good dielectric properties at reduced concentration of ceramics.

  10. HfO2 high-k solid-state incandescent devices: performance improvement using a Ti-embedded layer and observation of conductive paths as light-emitting sources. (United States)

    Liu, Yiwei; Yang, Can; Zhao, Jinyan; Wu, Shengli; Dai, Liyan; Niu, Gang


    Solid-state incandescent light-emission devices (SSI-LEDs) with a metal-oxide-semiconductor structure are promising candidates for future broadband light-emission devices. In this work, the electrical and light-emission features of SSI-LEDs based on HfO2 high-k thin films with or without the Ti-embedded layer on p-type silicon wafers have been studied. It turns out that the Ti-embedded layer can effectively reduce the turn-on voltage, thus improving the fluorescence efficiency of SSI-LEDs. The combination of scanning electron microscopy, atomic force microscope (AFM) and conductive AFM results unambiguously clarifies that conductive filaments, which are formed due to local thermal excitation during the forming process, are accompanied by the formation of pits on the HfO2 surface and are responsible for the light emission. This work develops an effective approach to improving the luminescence performance of SSI-LEDs and experimentally explains the light-emitting mechanism of such devices, which is of great importance to eventually realizng broadband light-emitting devices with low power consumption.

  11. Memory and negative-resistance effects in a strained metal-gate high-k n-type field-effect-transistor from 375 K down to 77 K (United States)

    Gutiérrez-D, E. A.; Vega-G, V. H.; García-R, P. J.; Huerta-G, O. V.


    We introduce an experimental alternative way of looking into the charging and discharging mechanism inside a high-k stacked oxide of a metal-gate strained n-type Field-Effect-Transistor (nFET). This alternative way reproduces a memory and negative resistance effect by biasing the nFET device in a non-conventional way. This is achieved by forward-biasing the drain-bulk junction and by setting the gate electrode in a high-impedance mode. The produced negative resistance effect (NRE) has a controllable peak-to-valley current ratio (PVCR) that goes from about 3.0 up to a value of 5.5 at room temperature. The PVCR increases up to 8.35 at T = 225 K and reduces to 2.84 at T = 375 K in a linear trend. The memory effect is observed when the drain-bulk junction voltage is swept from low to high values and back from high to low values. From low to high forward drain-bulk bias the NRE shows up and vanishes when coming back from high to low forward drain-bulk bias. The NRE and memory effects are attributed to a coupled-gate oxide charging/discharging mechanism with an induced bipolar transistor action in the channel of the FET.

  12. Ka Band Phase Locked Loop Oscillator Dielectric Resonator Oscillator for Satellite EHF Band Receiver

    Directory of Open Access Journals (Sweden)

    S. Coco


    Full Text Available This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very high Q dielectric resonator.

  13. V-band electronically reconfigurable metamaterial (United States)

    Radisic, Vesna; Hester, Jimmy G.; Nguyen, Vinh N.; Caira, Nicholas W.; DiMarzio, Donald; Hilgeman, Theodore; Larouche, Stéphane; Kaneshiro, Eric; Gutierrez-Aitken, Augusto


    In this work, we report on a reconfigurable V-band metamaterial fabricated using an InP heterojunction bipolar transistor production process. As designed and fabricated, the implementation uses complementary split ring resonators (cSRRs) and Schottky diodes in both single unit cell and three unit cell monolithic microwave integrated circuits. Each unit cell has two diodes embedded within the gaps of the cSRRs. Reconfigurability is achieved by applying an external bias that turns the diodes on and off, which effectively controls the resonant property of the structure. In order to measure the metamaterial properties, the unit cells are fed and followed by transmission lines. Measured data show good agreement with simulations and demonstrate that the metamaterial structure exhibits resonance at around 65 GHz that can be switched on and off. The three-unit cell transmission line metamaterial shows a deeper resonance and a larger phase change than a single cell, as expected. These are the first reported reconfigurable metamaterials operating at the V-band using the InP high speed device fabrication process.

  14. Changing optical band structure with single photons (United States)

    Albrecht, Andreas; Caneva, Tommaso; Chang, Darrick E.


    Achieving strong interactions between individual photons enables a wide variety of exciting possibilities in quantum information science and many-body physics. Cold atoms interfaced with nanophotonic structures have emerged as a platform to realize novel forms of nonlinear interactions. In particular, when atoms are coupled to a photonic crystal waveguide, long-range atomic interactions can arise that are mediated by localized atom-photon bound states. We theoretically show that in such a system, the absorption of a single photon can change the band structure for a subsequent photon. This occurs because the first photon affects the atoms in the chain in an alternating fashion, thus leading to an effective period doubling of the system and a new optical band structure for the composite atom-nanophotonic system. We demonstrate how this mechanism can be engineered to realize a single-photon switch, where the first incoming photon switches the system from being highly transmissive to highly reflective, and analyze how signatures can be observed via non-classical correlations of the outgoing photon field.

  15. Tunable metamaterial dual-band terahertz absorber (United States)

    Luo, C. Y.; Li, Z. Z.; Guo, Z. H.; Yue, J.; Luo, Q.; Yao, G.; Ji, J.; Rao, Y. K.; Li, R. K.; Li, D.; Wang, H. X.; Yao, J. Q.; Ling, F. R.


    We report a design of a temperature controlled tunable dual band terahertz absorber. The compact single unit cell consists of two nested closed square ring resonators and a layer metallic separated by a substrate strontium titanate (STO) dielectric layer. It is found that the absorber has two distinctive absorption peaks at frequencies 0.096 THz and 0.137 THz, whose peaks are attained 97% and 75%. Cooling the absorber from 400 K to 250 K causes about 25% and 27% shift compared to the resonance frequency of room temperature, when we cooling the temperature to 150 K, we could attained both the two tunabilities exceeding 53%. The frequency tunability is owing to the variation of the dielectric constant of the low-temperature co-fired ceramic (LTCC) substrate. The mechanism of the dual band absorber is attributed to the overlapping of dual resonance frequencies, and could be demonstrated by the distributions of the electric field. The method opens up avenues for designing tunable terahertz devices in detection, imaging, and stealth technology.

  16. Valence band effective Hamiltonians in nitride semiconductors (United States)

    Punya, Atchara; Schwertfager, Nucharee; Lambrecht, Walter


    Valence band effective Hamiltonians are useful to determine the electronic states of shallow impurities, quantum wells, quantum wires and quantum dots within the effective mass approximation. Although significant experimental and theoretical work has been performed, basic parameters such as the Rashba Sheka Pikus (RSP) Hamiltonian parameters are still uncertain. In this work, the electronic band structures of AlN, GaN and InN, all in the wurtzite crystal structure, as well as the RSP Hamiltonian parameters are determined by using the QSGW approximation in a FP-LMTO implementation. The corrections offered by this approach beyond the LDA are important to obtain the splittings and effective masses accurately. The present GW implementation, which allows for a real space representation of the self-energy, enables us to interpolate exactly to a fine k-mesh and hence to obtain accurate effective masses. We find the crystal field splitting in GaN (12 meV) in much closer agreement with experiment than previous work and obtain a negative SO coupling for InN. Moreover, we have generalized the method of invariants to crystals with orthorombic symmetry, such as ZnSiN2 ZnGeN2, ZnSnN2 and CdGeN2 and determined the corresponding Hamiltonian parameters.

  17. Broad-Band Activatable White-Opsin.

    Directory of Open Access Journals (Sweden)

    Subrata Batabyal

    Full Text Available Currently, the use of optogenetic sensitization of retinal cells combined with activation/inhibition has the potential to be an alternative to retinal implants that would require electrodes inside every single neuron for high visual resolution. However, clinical translation of optogenetic activation for restoration of vision suffers from the drawback that the narrow spectral sensitivity of an opsin requires active stimulation by a blue laser or a light emitting diode with much higher intensities than ambient light. In order to allow an ambient light-based stimulation paradigm, we report the development of a 'white-opsin' that has broad spectral excitability in the visible spectrum. The cells sensitized with white-opsin showed excitability at an order of magnitude higher with white light compared to using only narrow-band light components. Further, cells sensitized with white-opsin produced a photocurrent that was five times higher than Channelrhodopsin-2 under similar photo-excitation conditions. The use of fast white-opsin may allow opsin-sensitized neurons in a degenerated retina to exhibit a higher sensitivity to ambient white light. This property, therefore, significantly lowers the activation threshold in contrast to conventional approaches that use intense narrow-band opsins and light to activate cellular stimulation.

  18. Warm-Up Activities of Middle and High School Band Directors Participating in State-Level Concert Band Assessments (United States)

    Ward, Justin P.; Hancock, Carl B.


    The purpose of this study was to examine the warm-ups chosen by concert band directors participating in state-level performance assessments. We observed 29 middle and high school bands and coded the frequency and duration of warm-up activities and behaviors. Results indicated that most bands rehearsed music and played scales, long tones, and…

  19. Multi-band CRLH unit cell -loaded patch antenna (United States)

    El-Henawy, Sally I.; Omar, Ahmed A.; Safwat, Amr M. E.; El-Hennawy, Hadia S.


    A multi-band patch antenna loaded with composite right-/left-handed (CRLH) unit cell is presented in this paper. It operates at three bands, which are not harmonically related, covering several communication standards. The first and third bands have patch-like radiation pattern, and the second band has monopole-like radiation pattern. These bands can be controlled by varying the patch size and unit cell element values. The performance was analyzed using both electromagnetic and circuit simulations; furthermore, measurements were taken and all were in good agreement.

  20. Vortex in holographic two-band superfluid/superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mu-Sheng [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); National Center of Theoretical Sciences, National Tsing Hua University, Hsinchu, Taiwan 300, R.O.C. (China); Wu, Shang-Yu [Department of Electrophysics and Shing-Tung Yau Center, National Chiao Tung University, Hsinchu, Taiwan 300, R.O.C. (China); Zhang, Hai-Qing [Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht (Netherlands)


    We construct numerically static vortex solutions in a holographic model of two-band superconductor with an interband Josephson coupling in both the superfluid and superconductor regime. We investigate the effects of the interband coupling on the order parameter of each superconducting band in the vortex solution, and we find that it is different for each of the two bands. We compute also the free energy, critical magnetic field, magnetic penetration length and coherence lengths for the two bands, and we study their dependence on the interband coupling and temperature. Interestingly, we find that the coherence lengths of the two bands are close to identical.

  1. A colored leg banding technique for Amazona parrots (United States)

    Meyers, J.M.


    A technique for individual identification of Amazona was developed using plastic leg bands. Bands were made from 5- and 7-mm-wide strips of laminated PVC coiled 2.5 times with an inside diameter 4-5 mm gt the maximum diameter of the parrot's leg. Seventeen parrots were captured in Puerto Rico, marked with individual plastic leg bands, and observed for 204-658 d with only one lost or damaged plastic band. Plastic leg bands did not cause injury to or calluses on parrots' legs. The plastic material used for making leg bands was available in 18 colors in 1994, which would allow unique marking of 306 individuals using one plastic leg band on each leg.

  2. Thermoelectric band engineering: The role of carrier scattering (United States)

    Witkoske, Evan; Wang, Xufeng; Lundstrom, Mark; Askarpour, Vahid; Maassen, Jesse


    Complex electronic band structures, with multiple valleys or bands at the same or similar energies, can be beneficial for thermoelectric performance, but the advantages can be offset by inter-valley and inter-band scattering. In this paper, we demonstrate how first-principles band structures coupled with recently developed techniques for rigorous simulation of electron-phonon scattering provide the capabilities to realistically assess the benefits and trade-offs associated with these materials. We illustrate the approach using n-type silicon as a model material and show that intervalley scattering is strong. This example shows that the convergence of valleys and bands can improve thermoelectric performance, but the magnitude of the improvement depends sensitively on the relative strengths of intra- and inter-valley electron scattering. Because anisotropy of the band structure also plays an important role, a measure of the benefit of band anisotropy in the presence of strong intervalley scattering is presented.

  3. Formation of Degenerate Band Gaps in Layered Systems

    Directory of Open Access Journals (Sweden)

    Alexey P. Vinogradov


    Full Text Available In the review, peculiarities of spectra of one-dimensional photonic crystals made of anisotropic and/or magnetooptic materials are considered. The attention is focused on band gaps of a special type—the so called degenerate band gaps which are degenerate with respect to polarization. Mechanisms of formation and properties of these band gaps are analyzed. Peculiarities of spectra of photonic crystals that arise due to the linkage between band gaps are discussed. Particularly, it is shown that formation of a frozen mode is caused by linkage between Brillouin and degenerate band gaps. Also, existence of the optical Borrmann effect at the boundaries of degenerate band gaps and optical Tamm states at the frequencies of degenerate band gaps are analyzed.

  4. Bi-directional evolutionary optimization for photonic band gap structures (United States)

    Meng, Fei; Huang, Xiaodong; Jia, Baohua


    Toward an efficient and easy-implement optimization for photonic band gap structures, this paper extends the bi-directional evolutionary structural optimization (BESO) method for maximizing photonic band gaps. Photonic crystals are assumed to be periodically composed of two dielectric materials with the different permittivity. Based on the finite element analysis and sensitivity analysis, BESO starts from a simple initial design without any band gap and gradually re-distributes dielectric materials within the unit cell so that the resulting photonic crystal possesses a maximum band gap between two specified adjacent bands. Numerical examples demonstrated the proposed optimization algorithm can successfully obtain the band gaps from the first to the tenth band for both transverse magnetic and electric polarizations. Some optimized photonic crystals exhibit novel patterns markedly different from traditional designs of photonic crystals.

  5. Extending the ICRF above S/X-band: X/Ka-band Global Astrometric Results (United States)

    Jacobs, Christopher; Sovers, Ojars


    In order to extend the International Celestial Reference Frame from its S/X-band (2.3/8.4 GHz) basis to a complementary frame at X/Ka-band (8.4/32 GHz), we began an ongoing series of X/Ka observations starting in mid-2005 using NASA's Deep Space Network DSN) radio telescopes. This paper will report global astrometric results from the first 33 sessions. These sessions covered the full 24 hours of right ascension and declination down to -45 degrees. Our analysis produced a radio frame of 318 sources with median formal position uncertainties of ∼0.25 milliarcsec (mas). A comparison of our X/Ka-band frame against S/X-band shows wRMS differences of ∼0.25 mas. These differences include zonal errors the largest of which is a trend vs. declination. We will discuss our error budget including systematic errors from limited sensitivity, mis-modelling of the troposphere, and uncalibrated instrumental effects. We will discuss our plan for addressing the current limiting errors and the resulting prospects for improved accuracy over the next few years.

  6. Quantum confinement induced shift in energy band edges and band gap of a spherical quantum dot (United States)

    Borah, P.; Siboh, D.; Kalita, P. K.; Sarma, J. K.; Nath, N. M.


    We have proposed and validated an ansatz as effective potential for confining electron/hole within a spherical quantum dot in order to understand quantum confinement and its consequences associated with energy states and band gap of Spherical Quantum Dots. Within effective mass approximation formalism, we have considered an ansatz incorporating a conjoined harmonic oscillator and Coulomb interaction as the effective potential for confining an electron or a hole within a spherical quantum dot and by employing appropriate boundary conditions, we have calculated the shifts in energy of minimum of conduction band (CBM) and maximum of valence band (VBM) with respect to size of spherical quantum dots. We have also determined the quantum confinement induced shift in band gap energy of spherical quantum dots. In order to verify our theoretical predictions as well as to validate our ansatz, we have performed phenomenological analysis in comparison with available experimental results for quantum dots made of CdSe and observe a very good agreement in this regard. Our experimentally consistent theoretical results also help in mapping the probability density of electron and hole inside a spherical quantum dot. The consistency of our results with available experimental data signifies the capability as well as applicability of the ansatz for the effective confining potential to have reasonable information in the study of real nano-structured spherical systems.

  7. Subcutaneous fascial bands--a qualitative and morphometric analysis. (United States)

    Li, Weihui; Ahn, Andrew C


    Although fascial bands within the subcutaneous (SQ) layer are commonly seen in ultrasound images, little is known about their functional role, much less their structural characteristics. This study's objective is to describe the morphological features of SQ fascial bands and to systematically evaluate the bands using image analyses tools and morphometric measures. In 28 healthy volunteers, ultrasound images were obtained at three body locations: the lateral aspect of the upper arm, medial aspect of the thigh and posterior aspect of lower leg. Using image analytical techniques, the total SQ band area, fascial band number, fascial band thickness, and SQ zone (layer) thickness were determined. In addition, the SQ spatial coherence was calculated based on the eigenvalues associated with the largest and smallest eigenvectors of the images. Fascial bands at these sites were contiguous with the dermis and the epimysium forming an interconnected network within the subcutaneous tissue. Subcutaneous blood vessels were also frequently encased by these fascial bands. The total SQ fascial band area was greater at the thigh and calf compared to the arm and was unrelated to SQ layer (zone) thickness. The thigh was associated with highest average number of fascial bands while calf was associated with the greatest average fascial band thickness. Across body regions, greater SQ zone thickness was associated with thinner fascial bands. SQ coherence was significantly associated with SQ zone thickness and body location (calf with statistically greater coherence compared to arm). Fascial bands are structural bridges that mechanically link the skin, subcutaneous layer, and deeper muscle layers. This cohesive network also encases subcutaneous vessels and may indirectly mediate blood flow. The quantity and morphological characteristics of the SQ fascial band may reflect the composite mechanical forces experienced by the body part.

  8. Subcutaneous fascial bands--a qualitative and morphometric analysis.

    Directory of Open Access Journals (Sweden)

    Weihui Li

    Full Text Available BACKGROUND: Although fascial bands within the subcutaneous (SQ layer are commonly seen in ultrasound images, little is known about their functional role, much less their structural characteristics. This study's objective is to describe the morphological features of SQ fascial bands and to systematically evaluate the bands using image analyses tools and morphometric measures. METHODS: In 28 healthy volunteers, ultrasound images were obtained at three body locations: the lateral aspect of the upper arm, medial aspect of the thigh and posterior aspect of lower leg. Using image analytical techniques, the total SQ band area, fascial band number, fascial band thickness, and SQ zone (layer thickness were determined. In addition, the SQ spatial coherence was calculated based on the eigenvalues associated with the largest and smallest eigenvectors of the images. RESULTS: Fascial bands at these sites were contiguous with the dermis and the epimysium forming an interconnected network within the subcutaneous tissue. Subcutaneous blood vessels were also frequently encased by these fascial bands. The total SQ fascial band area was greater at the thigh and calf compared to the arm and was unrelated to SQ layer (zone thickness. The thigh was associated with highest average number of fascial bands while calf was associated with the greatest average fascial band thickness. Across body regions, greater SQ zone thickness was associated with thinner fascial bands. SQ coherence was significantly associated with SQ zone thickness and body location (calf with statistically greater coherence compared to arm. CONCLUSION: Fascial bands are structural bridges that mechanically link the skin, subcutaneous layer, and deeper muscle layers. This cohesive network also encases subcutaneous vessels and may indirectly mediate blood flow. The quantity and morphological characteristics of the SQ fascial band may reflect the composite mechanical forces experienced by the body part.

  9. New results on the superdeformed {sup 196}Pb nucleus: The decay of the excited bands to the yrast band

    Energy Technology Data Exchange (ETDEWEB)

    Bouneau, S.; Azaiez, F.; Duprat, J. [IPN, Orsay (France)] [and others


    The study of the superdeformed (SD) {sup 196}Pb nucleus has been revisited using the EUROGAM phase 2 spectrometer. In addition to the known yrast and two lowest excited SD bands, a third excited SD band has been seen. All of the three excited bands were found to decay to the yrast SD band through, presumably, E1 transitions, allowing relative spin and excitation energy assignments. Comparisons with calculations using the random-phase approximation suggest that all three excited bands can be interpreted as octupole vibrational structures.

  10. Eastern Band of Cherokee Strategic Energy Plan

    Energy Technology Data Exchange (ETDEWEB)

    Souther Carolina Institute of energy Studies-Robert Leitner


    The Eastern Band of Cherokee Indians was awarded a grant under the U.S. Department of Energy Tribal Energy Program (TEP) to develop a Tribal Strategic Energy Plan (SEP). The grant, awarded under the “First Steps” phase of the TEP, supported the development of a SEP that integrates with the Tribe’s plans for economic development, preservation of natural resources and the environment, and perpetuation of Tribal heritage and culture. The Tribe formed an Energy Committee consisting of members from various departments within the Tribal government. This committee, together with its consultant, the South Carolina Institute for Energy Studies, performed the following activities: • Develop the Tribe’s energy goals and objectives • Establish the Tribe’s current energy usage • Identify available renewable energy and energy efficiency options • Assess the available options versus the goals and objectives • Create an action plan for the selected options

  11. Band structure peculiarities of magnetic photonic crystals (United States)

    Gevorgyan, A. H.; Golik, S. S.


    In this work we studied light diffraction in magneto-photonic crystals (MPC) having large magneto-optical activity and modulation large depth. The case of arbitrary angles between the direction of the external static magnetic field and the normal to the border of the MPC layer is considered. The problem is solved by Ambartsumian's modified layer addition method. It is found that there is a new type of non-reciprocity, namely, the relation R (α) ≠ R (- α) takes place, where R is the reflection coefficient, and α is the incidence angle. It is shown the formation of new photonic band gap (PBG) at oblique incidence of light, which is not selective for the polarization of the incident light, in the case when the external magnetic field is directed along the medium axis. Such a system can be used as: a tunable polarization filter, polarization mirror, circular (elliptical) polarizer, tunable optical diode, etc.

  12. Narrow band imaging for bladder cancer

    Directory of Open Access Journals (Sweden)

    Thomas Y. Hsueh


    Full Text Available Narrow band imaging (NBI is a newly developed technology aiming to provide additional endoscopic information for patients with bladder cancer. This review focuses on the diagnostic accuracy and treatment outcome using NBI cystoscopy for the treatment of non-muscle invasive bladder cancer. Current results showed improved sensitivity of NBI cystoscopy compared to conventional white light cystoscopy, although lower specificity and increased false-positive results were reported using NBI cystoscopy. The treatment outcome using NBI technology in transurethral resection of bladder tumor had a positive impact while decreased number of residual tumors and tumor recurrence at follow-up were reported. In the future, the application of NBI technology might refine the treatment and follow-up protocol in patients with non-muscle invasive bladder cancer. However, this large scale prospective studies are required to confirm the real cost-effectiveness of this new technology.

  13. Line Intensity and Position Measurements and Derived Band Parameters of the 31103-00001 C-12 O-16(2) Band and its Two Nearby Hot Bands (United States)

    Giver, Lawrence P.; Kshirsagar, Rohidas J.; Freedman, Richard S.; Chackerian, Charles, Jr.; Wattson, Richard B.; Brown, Linda R.; Gore, Warren J. (Technical Monitor)


    A set of CO2 spectra from 4500 to 4780/cm has been obtained an Ames with 1500 m path length using a Bomem DA8 FTS. This spectral region contains a number of weak bands and minor isotopic bands that have been studied at high resolution in the reflection spectrum of Venus by Mandin. Improved laboratory intensity and position measurements should assist modeling the Venus reflection spectra and improve understanding of Venus' upper atmosphere. Also, the laboratory measurements will assist DND intensity computations of weaker bands that cannot be measured, but which are nevertheless significant absorbers in Venus' hot, deep CO2, atmosphere. For example, some of the weaker bands that are members of the same polyads as the bands in this presentation lie in the nearby 2.3 microns emission window in Venus' night-side spectrum.

  14. Dead pixel correction techniques for dual-band infrared imagery (United States)

    Nguyen, Chuong T.; Mould, Nick; Regens, James L.


    We present two new dead pixel correction algorithms for dual-band infrared imagery. Specifically, we address the problem of repairing unresponsive elements in the sensor array using signal processing techniques to overcome deficiencies in image quality that are present following the nonuniformity correction process. Traditionally, dead pixel correction has been performed almost exclusively using variations of the nearest neighbor technique, where the value of the dead pixel is estimated based on pixel values associated with the neighboring image structure. Our approach differs from existing techniques, for the first time we estimate the values of dead pixels using information from both thermal bands collaboratively. The proposed dual-band statistical lookup (DSL) and dual-band inpainting (DIP) algorithms use intensity and local gradient information to estimate the values of dead pixels based on the values of unaffected pixels in the supplementary infrared band. The DSL algorithm is a regression technique that uses the image intensities from the reference band to estimate the dead pixel values in the band undergoing correction. The DIP algorithm is an energy minimization technique that uses the local image gradient from the reference band and the boundary values from the affected band to estimate the dead pixel values. We evaluate the effectiveness of the proposed algorithms with 50 dual-band videos. Simulation results indicate that the proposed techniques achieve perceptually and quantitatively superior results compared to existing methods.

  15. Single-band and Dual-band Artificial Magnetic Conductor Ground Planes for Multi-band Dipole Antenna

    Directory of Open Access Journals (Sweden)

    M. Abu


    Full Text Available Two new designs of high impedance surface (HIS structure are presented, namely zigzag and slotted rectangular with I-shaped slot Artificial Magnetic Conductor (AMC. The zigzag AMC is designed based on the straight dipole AMC. The zigzag AMC is introduced to minimize the AMC size and to be suitable for UHF RFID applications. On the other hand, the slotted rectangular with I-shaped slot AMC is designed to operate at 0.92 GHz and 2.45 GHz. The slot is loaded in the main patch of the AMC to create the other resonant frequency. By using this technique the resonant frequency can be lowered, and hence reduce the size of the AMC. Both structures are designed using the same dielectric substrate that is Taconic TLC-32. The properties of the AMC are investigated such as the reflection phase, reflection magnitude and surface impedance. The designed AMCs then are used as a back plane for the printed multi-band dipole antenna. By introducing the AMC as a ground plane (GP for the printed dipole antenna, the gain of the dipole antenna is increased.

  16. Split-face comparison between single-band and dual-band pulsed light technology for treatment of photodamage. (United States)

    Varughese, Neal; Keller, Lauren; Goldberg, David J


    Intense pulsed light (IPL) has a well-recognized role in the treatment of photodamaged skin. To assess the safety and efficacy of a novel single-band IPL handpiece versus dual-band IPL handpiece in the treatment of photodamage. This was a prospective, single-center split-face study with 20 enrolled participants. Three treatments, 21 days apart, were administered to the subjects and follow-up was performed for 20 weeks. The left side of the face was treated with the single-band handpiece. The right side of the face was treated with the dual-band handpiece. Blinded investigators assessed the subjects' skin texture, pigmented components of photodamage, and presence of telangiectasia both before and after treatment, utilizing a five-point scale. Pigmented components of photodamage, skin texture, and presence of telangiectasias on the left and right side of the face were improved at the end of treatment. At 20-week follow-up, the side treated with single-band handpiece showed improvement in telangiectasia and pigmentation that was statistically superior to the contralateral side treated with the dual-band handpiece. Both devices equally improved textural changes. No adverse effects were noted with either device. Both single-band and dual-band IPL technology are safe and effective in the treatment of photodamaged facial skin. IPL treatment with a single-band handpiece yielded results comparable or superior to dual-band technology.

  17. All-Optical Reconstruction of Crystal Band Structure. (United States)

    Vampa, G; Hammond, T J; Thiré, N; Schmidt, B E; Légaré, F; McDonald, C R; Brabec, T; Klug, D D; Corkum, P B


    The band structure of matter determines its properties. In solids, it is typically mapped with angle-resolved photoemission spectroscopy, in which the momentum and the energy of incoherent electrons are independently measured. Sometimes, however, photoelectrons are difficult or impossible to detect. Here we demonstrate an all-optical technique to reconstruct momentum-dependent band gaps by exploiting the coherent motion of electron-hole pairs driven by intense midinfrared femtosecond laser pulses. Applying the method to experimental data for a semiconductor ZnO crystal, we identify the split-off valence band as making the greatest contribution to tunneling to the conduction band. Our new band structure measurement technique is intrinsically bulk sensitive, does not require a vacuum, and has high temporal resolution, making it suitable to study reactions at ambient conditions, matter under extreme pressures, and ultrafast transient modifications to band structures.

  18. Review of wide band-gap semiconductors technology

    Directory of Open Access Journals (Sweden)

    Jin Haiwei


    Full Text Available Silicon carbide (SiC and gallium nitride (GaN are typical representative of the wide band-gap semiconductor material, which is also known as third-generation semiconductor materials. Compared with the conventional semiconductor silicon (Si or gallium arsenide (GaAs, wide band-gap semiconductor has the wide band gap, high saturated drift velocity, high critical breakdown field and other advantages; it is a highly desirable semiconductor material applied under the case of high-power, high-temperature, high-frequency, anti-radiation environment. These advantages of wide band-gap devices make them a hot spot of semiconductor technology research in various countries. This article describes the research agenda of United States and European in this area, focusing on the recent developments of the wide band-gap technology in the US and Europe, summed up the facing challenge of the wide band-gap technology.

  19. Flat Chern Band in a Two-Dimensional Organometallic Framework (United States)

    Liu, Zheng; Wang, Zheng-Fei; Mei, Jia-Wei; Wu, Yong-Shi; Liu, Feng


    By combining exotic band dispersion with nontrivial band topology, an interesting type of band structure, namely, the flat Chern band, has recently been proposed to spawn high-temperature fractional quantum Hall states. Despite the proposal of several theoretical lattice models, however, it remains doubtful whether such a “romance of flatland” could exist in a real material. Here, we present a first-principles design of a two-dimensional indium-phenylene organometallic framework that realizes a nearly flat Chern band right around the Fermi level by combining lattice geometry, spin-orbit coupling, and ferromagnetism. An effective four-band model is constructed to reproduce the first-principles results. Our design, in addition, provides a general strategy to synthesize topologically nontrivial materials by virtue of organic chemistry and nanotechnology.

  20. Band alignments of graphene-like III-nitride semiconductors (United States)

    Ota, Yuichi


    Band alignment in graphene-like III-nitride semiconductors was investigated using first principles calculations and an empirical formula. We estimated the band edge positions using two simple approaches based on the energy of the band gap center (BGC) and electron affinity rules. The energy positions relative to the vacuum level were determined from the BGC and Mulliken electronegativities. These methods provided similar trends in the band lineup. The valence band and conduction band offsets determined by the first principles calculations agreed with the empirical results to within 0.5 eV. The findings suggest that the first principles and empirical methods provide a useful guide for high-throughput device design.

  1. A Compact Printed Quadruple Band-Notched UWB Antenna

    Directory of Open Access Journals (Sweden)

    Xiaoyin Li


    Full Text Available A novel compact coplanar waveguide- (CPW- fed ultrawideband (UWB printed planar volcano-smoke antenna (PVSA with four band-notches for various wireless applications is proposed and demonstrated. The low-profile antenna consists of a C-shaped parasitic strip to generate a notched band at 8.01~8.55 GHz for the ITU band, two C-shaped slots, and an inverted U-shaped slot etched in the radiator patch to create three notched bands at 5.15~5.35 GHz, 5.75~5.85 GHz, and 7.25~7.75 GHz for filtering the WLAN and X-band satellite signals. Simulated and measured results both confirm that the proposed antenna has a broad bandwidth of 3.1~12 GHz with VSWR < 2 and good omnidirectional radiation patterns with four notched-bands.

  2. Plasmonic band gap engineering of plasmon-exciton coupling. (United States)

    Karademir, Ertugrul; Balci, Sinan; Kocabas, Coskun; Aydinli, Atilla


    Controlling plasmon-exciton coupling through band gap engineering of plasmonic crystals is demonstrated in the Kretschmann configuration. When the flat metal surface is textured with a sinusoidal grating only in one direction, using laser interference lithography, it exhibits a plasmonic band gap because of the Bragg scattering of surface plasmon polaritons on the plasmonic crystals. The contrast of the grating profile determines the observed width of the plasmonic band gap and hence allows engineering of the plasmonic band gap. In this work, resonant coupling between the molecular resonance of a J-aggregate dye and the plasmonic resonance of a textured metal film is extensively studied through plasmonic band gap engineering. Polarization dependent spectroscopic reflection measurements probe the spectral overlap occurring between the molecular resonance and the plasmonic resonance. The results indicate that plasmon-exciton interaction is attenuated in the band gap region along the grating direction.

  3. Notes on basis band-pass circuits; Notes sur les circuits de base passe-bande

    Energy Technology Data Exchange (ETDEWEB)

    Ailloud, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires


    Resistor load amplifier stages, basic band-pass RC networks, conventional single-tuned circuits, have the same transfer function. Common properties and differences because diverse magnitude of parameters with proposed problems are exposed. Next the case of several cascaded stages (or networks) is examined when there is no reaction ones to another. (author) [French] Les etages amplificateurs a resistances, les circuits passe-bande RC elementaires, le circuit resonnant classique possedent la meme fonction de transfert. On fait ressortir les proprietes communes et les differences de comportement dues aux ordres de grandeur qu'il est possible de donner aux parametres en fonction des problemes a resoudre. On examine ensuite le cas de plusieurs etages (ou de plusieurs circuits) en cascade lorsqu'ils ne reagissent pas les uns sur les autres. (auteur)


    Directory of Open Access Journals (Sweden)

    Hadi Baghali


    Full Text Available A 25×25×1.6mm3 implementation of a microstrip-fed printed monopole antenna for the future UWB wireless systems application is presented. It has features of possesses band notched function (from 4.88 to 6.07GHz, extremely wide impedance bandwidth (from 2.58 to 18GHz and its compact size. By using a smooth tapering between the semi fractal-shaped patch and the half ellipse-shaped defected ground plane, the wide impedance bandwidth is achieved with ratio bandwidth larger than 6.97:1. Numerical and experimental results are in good agreement and they indicate that the proposed antenna has a measured 2:1 VSWR bandwidth of 149.8%, except the rejected WLAN band.

  5. GaN MMIC Power Amplifiers for S-band and X-band

    NARCIS (Netherlands)

    Suijker, E.M.; Sudow, M.; Fagerlind, M.; Hek, A.P. de; Vliet, F.E. van; Rorsman, N.


    The development of two GaN MMIC power amplifiers is reported. The amplifiers are processed in the AlGaN/GaN technology of Chalmers University of Technology using 0.25 μm HEMTs. The S-band amplifier operates at frequencies from 3 to 4 GHz and has a maximum output power of 5.6 W with an associated

  6. Investigation of lifetimes in dipole bands of {sup 141}Eu

    Energy Technology Data Exchange (ETDEWEB)

    Podsvirova, E.O.; Pasternak, A.A. [Institut fuer Kernphysik, Forschungszentrum Juelich, D-52425, Juelich (Germany); A.F. Ioffe Physical Technical Institute RAS, RU-194021, St. Petersburg (Russian Federation); Lieder, R.M.; Gast, W.; Jaeger, H.M.; Mihailescu, L. [Institut fuer Kernphysik, Forschungszentrum Juelich, D-52425, Juelich (Germany); Chmel, S. [Institut fuer Strahlen- und Kernphysik, University of Bonn, D-53115, Bonn (Germany); Venkova, T. [Institut fuer Kernphysik, Forschungszentrum Juelich, D-52425, Juelich (Germany); Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia (Bulgaria); Angelis, G. de; Napoli, D.R.; Gadea, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020, Legnaro (Italy); Bazzacco, D.; Menegazzo, R.; Lunardi, S. [Dipartimento di Fisica dell' Universita and Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131, Padova (Italy); Urban, W.; Droste, C.; Morek, T.; Rzaca-Urban, T. [Institute of Experimental Physics, University of Warsaw, PL-00-681, Warszawa (Poland); Duchene, G. [Institut de Recherches Subatomique IReS, F-67037, Strasbourg (France)


    Lifetimes have been measured for dipole bands in {sup 141}Eu using DSAM. The deduced B(M1) and B(E2) values as well as B(M1)/B(E2) ratios are compared with calculations in the framework of the TAC (Tilted Axis Cranking) and SPAC (Shears mechanism with Principal Axis Cranking) models. The dipole bands can be interpreted as magnetic rotational bands. (orig.)

  7. Investigation of lifetimes in dipole bands of {sup 142}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Pasternak, A.A.; Podsvirova, E.O. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); A.F. Ioffe Physical Technical Institute, RAS, St. Petersburg (Russian Federation); Lieder, R.M.; Gast, W.; Jaeger, H.M.; Mihailescu, G. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Chmel, S. [University of Bonn, Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Venkova, T. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Bulgarian Academy of Sciences, Institute of Nuclear Research and Nuclear Energy, Sofia (Bulgaria); De Angelis, G.; Napoli, D.R.; Gadea, A. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Bazzacco, D.; Menegazzo, G.; Lunardi, R. [Universita di Padova, Dipartimento di Fisica, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy); Urban, W.; Droste, C.; Morek, T.; Rzaca-Urban, T. [University of Warsaw, Institute of Experimental Physics, Warszawa (Poland); Duchene, G. [Institut de Recherches Subatomique, IReS, Strasbourg (France); Dewald, A. [Universitaet zu Koeln, Institut fuer Kernphysik, Koeln (Germany)


    Lifetimes have been measured for dipole bands in {sup 142}Gd using DSAM. The deduced B(M1) and B(E2) values as well as B(M1)/B(E2) ratios are compared with calculations in the framework of the TAC (Tilted Axis Cranking) and SPAC (shears mechanism with Principal Axis Cranking) models. The dipole bands DB1 to DB4 can be interpreted as magnetic rotational bands. (orig.)

  8. Gastropericardial Fistula as a Late Complication of Laparoscopic Gastric Banding

    Directory of Open Access Journals (Sweden)

    Adam A Rudd


    Full Text Available Laparoscopic adjustable gastric banding (LAGB is a bariatric procedure that is being performed with increasing frequency as an alternative management option for morbid obesity. Several common complications have been reported including gastric band slippage and associated pouch dilatation, intragastric erosion of the band, gastric wall perforation, and abscess formation. We present a case of gastropericardial fistula occurring nine years after an LAGB. There have been no previous documented cases of the complication after this procedure.

  9. Deep-Space Ka-Band Flight Experience (United States)

    Morabito, D. D.


    Lower frequency bands have become more congested in allocated bandwidth as there is increased competition between flight projects and other entities. Going to higher frequency bands offers significantly more bandwidth, allowing for the use of much higher data rates. However, Ka-band is more susceptible to weather effects than lower frequency bands currently used for most standard downlink telemetry operations. Future or prospective flight projects considering deep-space Ka-band (32-GHz) telemetry data links have expressed an interest in understanding past flight experience with received Ka-band downlink performance. Especially important to these flight projects is gaining a better understanding of weather effects from the experience of current or past missions that operated Ka-band radio systems. We will discuss the historical flight experience of several Ka-band missions starting from Mars Observer in 1993 up to present-day deep-space missions such as Kepler. The study of historical Ka-band flight experience allows one to recommend margin policy for future missions. Of particular interest, we will review previously reported-on flight experience with the Cassini spacecraft Ka-band radio system that has been used for radio science investigations as well as engineering studies from 2004 to 2015, when Cassini was in orbit around the planet Saturn. In this article, we will focus primarily on the Kepler spacecraft Ka-band link, which has been used for operational telemetry downlink from an Earth trailing orbit where the spacecraft resides. We analyzed the received Ka-band signal level data in order to characterize link performance over a wide range of weather conditions and as a function of elevation angle. Based on this analysis of Kepler and Cassini flight data, we found that a 4-dB margin with respect to adverse conditions ensures that we achieve at least a 95 percent data return.

  10. Biconical Ring Antenna Array for Wide Band Applications


    C.SUBBA RAO; Sudhakar, A.


    Circular or ring arrays are conformal to the cylindrical surfaces unlike the linear arrays and can be mounted on moving objects. Biconical antenna is simple in construction and exhibits broad band characteristics. This antenna presents broad band radiation characteristics. In this paper circular or ring array of biconical antenna is proposed and its characteristics are analyzed for frequency band of 0.1 to 1GHz range. Radiation characteristicsof the array with excitation phase change are pres...

  11. Higher-band gap soliton formation in defocusing photonic lattices. (United States)

    Kip, Detlef; Rüter, Christian E; Dong, Rong; Wang, Zhe; Xu, Jingjun


    We report on the experimental observation of higher-band gap solitons in a one-dimensional photonic lattice possessing a defocusing saturable nonlinearity. Pure Floquet-Bloch modes of the first three bands are excited using a prism-coupler setup, and spatial gap solitons of different width are formed, the latter property being related to the increasing anomalous diffraction in the three bands and the fixed value of the nonlinearity in our lithium niobate sample.

  12. Identical gamma-vibrational bands in {sup 165}Ho

    Energy Technology Data Exchange (ETDEWEB)

    Radford, D.C.; Galindo-Uribarri, A.; Janzen, V.P. [Chalk River Labs., Ontario (Canada)] [and others


    The structure of {sup 165}Ho at moderate spins has been investigated by means of Coulomb excitation. Two {gamma}-vibrational bands (K{sup {pi}} = 11/2{sup {minus}} and K{sup {pi}} = 3/2{sup {minus}}) are observed, with very nearly identical in-band {gamma}-ray energies. Gamma-ray branching ratios are analyzed to extract information on Coriolis mixing, and the role of the K quantum number in identical bands is discussed.

  13. Analysis of single band and dual band graphene based patch antenna for terahertz region (United States)

    George, Jemima Nissiyah; Madhan, M. Ganesh


    A microstrip patch antenna is designed using a very thin layer of graphene as the radiating patch, which is fed by a microstrip transmission line. The graphene based patch is designed on a silicon substrate having a dielectric constant of 11.9, to radiate at a single frequency of 2.6 THz. Further, this antenna is made to resonate at dual frequencies of 2.48 THz and 3.35 THz, by changing the substrate height, which is reported for the first time. Various antenna parameters such as return loss, VSWR, gain, efficiency and bandwidth are also determined for the single and dual band operation. For the single band operation, a bandwidth of 145.4 GHz and an efficiency of 92% was achieved. For dual band operation, a maximum bandwidth of 140.5 GHz was obtained at 3.35 THz and an efficiency of 87.3% was obtained at the first resonant frequency of 2.48 THz. The absorption cross section of the antenna is also analysed for various substrate heights and has maximum peaks at the corresponding resonating frequencies. The simulation has been carried out by using a full wave electromagnetic simulator based on FDTD method.

  14. A New Wide-Band Double-Negative Metamaterial for C- and S-Band Applications. (United States)

    Hossain, Md Ikbal; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul; Ullah, Mohammad Habib


    A new design and analysis of a wide-band double-negative metamaterial, considering a frequency range of 0.5 to 7 GHz, is presented in this paper. Four different unit cells with varying design parameters are analyzed to evaluate the effects of the unit-cell size on the resonance frequencies of the metamaterial. Moreover, open and interconnected 2 × 2 array structures of unit cells are analyzed. The finite-difference time-domain (FDTD) method, based on the Computer Simulation Technology (CST) Microwave Studio, is utilized in the majority of this investigation. The experimental portion of the study was performed in a semi-anechoic chamber. Good agreement is observed between the simulated and measured S parameters of the developed unit cell and array. The designed unit cell exhibits negative permittivity and permeability simultaneously at S-band (2.95 GHz to 4.00 GHz) microwave frequencies. In addition, the designed unit cell can also operate as a double-negative medium throughout the C band (4.00 GHz to 4.95 GHz and 5.00 GHz to 5.57 GHz). At a number of other frequencies, it exhibits a single negative value. The two array configurations cause a slight shift in the resonance frequencies of the metamaterial and hence lead to a slight shift of the single- and double-negative frequency ranges of the metamaterial.

  15. A New Wide-Band Double-Negative Metamaterial for C- and S-Band Applications

    Directory of Open Access Journals (Sweden)

    Md Ikbal Hossain


    Full Text Available A new design and analysis of a wide-band double-negative metamaterial, considering a frequency range of 0.5 to 7 GHz, is presented in this paper. Four different unit cells with varying design parameters are analyzed to evaluate the effects of the unit-cell size on the resonance frequencies of the metamaterial. Moreover, open and interconnected 2 × 2 array structures of unit cells are analyzed. The finite-difference time-domain (FDTD method, based on the Computer Simulation Technology (CST Microwave Studio, is utilized in the majority of this investigation. The experimental portion of the study was performed in a semi-anechoic chamber. Good agreement is observed between the simulated and measured S parameters of the developed unit cell and array. The designed unit cell exhibits negative permittivity and permeability simultaneously at S-band (2.95 GHz to 4.00 GHz microwave frequencies. In addition, the designed unit cell can also operate as a double-negative medium throughout the C band (4.00 GHz to 4.95 GHz and 5.00 GHz to 5.57 GHz. At a number of other frequencies, it exhibits a single negative value. The two array configurations cause a slight shift in the resonance frequencies of the metamaterial and hence lead to a slight shift of the single- and double-negative frequency ranges of the metamaterial.

  16. Cost-effective restrictive bariatric surgery: laparoscopic vertical banded gastroplasty versus laparoscopic adjustable gastric band. (United States)

    Ojo, Peter; Valin, Elmer


    Among bariatric restrictive operations, the procedure of choice is still controversial. The aim of this study is to compare the cost of two gastric restrictive procedures: laparoscopic vertical banded gastroplasty (LVBG) and laparoscopic adjustable gastric banding (LAGB). This is a prospective nonrandomized study comparing the cost effectiveness of LVBG and LAGB. Fifty-nine LVBG are compared to 83 LAGB performed during the same period, September 2005 and August 2006. Both groups demonstrate similar body mass index range and gender distribution. Cost analysis is evaluated as: preoperative, intraoperative, postoperative, follow-up, and management of complication cost. Both groups have similar preoperative and immediate postoperative cost. The material cost for LVBG is significantly lower than for LAGB ($1,326.42 for LVBG to $3,253.42 for LAGB). This material cost, however, excludes instruments and materials that are used in both procedures. Although both groups have similar postoperative routine visits, LAGB visits require band fills which increase its cost by $28 if fills are by palpation or $179 if by ultrasound. The complications in LAGB were also more severe with four patients returning to the operating room and another one medically managed for pulmonary embolism. These are at a higher cost compared to LVBG where none of the patients require reoperation or readmissions. The rate of percentage excess weight loss in LVBG patients however is more rapid than in LAGB patients. LVBG required less expensive instruments and materials for the operation and was associated with a higher rate of weight loss and less complications.

  17. The SBR toolbox - software for successive band reduction.

    Energy Technology Data Exchange (ETDEWEB)

    Bischof, C. H.; Lang, B.; Sun, X.; Mathematics and Computer Science; Bergische Univ. GH Wuppertal; Duke Univ.


    We present a software toolbox for symmetric band reduction via orthogonal transformations, together with a testing and timing program. The toolbox contains drivers and computational routines for the reduction of full symmetric matrices to banded form and the reduction of banded matrices to narrower banded or tridiagonal form, with optional accumulation of the orthogonal transformations, as well as repacking routines for storage rearrangement. The functionality and the calling sequences of the routines are described, with a detailed discussion of the 'control' parameters that allow adaptation of the codes to particular machine and matrix characteristics. We also briefly describe the testing and timing program included in the toolbox.

  18. Inter-band dynamics in a tunable hexagonal lattice (United States)

    Windpassinger, Patrick; Weinberg, Malte; Simonet, Juliette; Struck, Julian; Oelschlaeger, Christoph; Luehmann, Dirk; Sengstock, Klaus


    Hexagonal lattices have recently attracted a lot of attention in the condensed matter community and beyond. Upon other intriguing features, their unique band structure exhibits Dirac cones at the corners of the Brillouin zone of the two lowest energy bands. Here, we report on the experimental observation of momentum-resolved inter-band dynamics of ultracold bosons between the two lowest Bloch bands (s- and p-band) of a hexagonal optical lattice with tunable band structure. Due to the spin-dependency of the lattice potential [1,2], a rotation of the magnetic quantization axis and the choice of the atomic spin state allow for an in-situ manipulation of the lattice structure from hexagonal to triangular geometry. It is thus possible to modify the band structure and open a gap at the Dirac cones. The loading of atoms into the excited band is achieved by a microwave transition between different spin states which in certain cases is only allowed as a result of interaction effects. We observe the time-dependent population of quasi momenta, revealing a striking influence of the existence of Dirac cones on the dynamics of atoms in the first two energy bands.[4pt] [1] P. Soltan-Panahi et al., Nature Physics 7, 43 (2011)[0pt] [2] P. Soltan-Panahi et al., Nature Physics 8, 71 (2012)

  19. Compact flat band states in optically induced flatland photonic lattices (United States)

    Travkin, Evgenij; Diebel, Falko; Denz, Cornelia


    We realize low-dimensional tight-binding lattices that host flat bands in their dispersion relation and demonstrate the existence of optical compact flat band states. The lattices are resembled by arrays of optical waveguides fabricated by the state-of-the-art spatio-temporal Bessel beam multiplexing optical induction in photorefractive media. We work out the decisive details of the transition from the discrete theory to the real optical system ensuring that the experimental lattices stand up to numerical scrutiny exhibiting well-approximated band structures. Our highly flexible system is a promising candidate for further experimental investigation of theoretically studied disorder effects in flat band lattices.

  20. Glucose Absorption by the Bacillary Band of Trichuris muris

    DEFF Research Database (Denmark)

    Hansen, Tina Vicky Alstrup; Hansen, Michael; Nejsum, Peter


    of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG) and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose. Principal Findings....... Conclusions/Significance Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake...

  1. Band structures in the nematic elastomers phononic crystals (United States)

    Yang, Shuai; Liu, Ying; Liang, Tianshu


    As one kind of new intelligent materials, nematic elastomers (NEs) represent an exciting physical system that combines the local orientational symmetry breaking and the entropic rubber elasticity, producing a number of unique physical phenomena. In this paper, the potential application of NEs in the band tuning is explored. The band structures in two kinds of NE phononic crystals (PCs) are investigated. Through changing NE intrinsic parameters, the influence of the porosity, director rotation and relaxation on the band structures in NE PCs are analyzed. This work is a meaningful try for application of NEs in acoustic field and proposes a new intelligent strategy in band turning.

  2. Workshop: Western hemisphere network of bird banding programs (United States)

    Celis-Murillo, A.


    Purpose: To promote collaboration among banding programs in the Americas. Introduction: Bird banding and marking provide indispensable tools for ornithological research, management, and conservation of migratory birds on migratory routes, breeding and non-breeding grounds. Many countries and organizations in Latin America and the Caribbean are in the process of developing or have expressed interest in developing national banding schemes and databases to support their research and management programs. Coordination of developing and existing banding programs is essential for effective data management, reporting, archiving and security, and most importantly, for gaining a fuller understanding of migratory bird conservation issues and how the banding data can help. Currently, there is a well established bird-banding program in the U.S.A. and Canada, and programs in other countries are being developed as well. Ornithologists in many Latin American countries and the Caribbean are interested in using banding and marking in their research programs. Many in the ornithological community are interested in establishing banding schemes and some countries have recently initiated independent banding programs. With the number of long term collaborative and international initiatives increasing, the time is ripe to discuss and explore opportunities for international collaboration, coordination, and administration of bird banding programs in the Western Hemisphere. We propose the second ?Western Hemisphere Network of Bird Banding Programs? workshop, in association with the SCSCB, to be an essential step in the progress to strengthen international partnerships and support migratory bird conservation in the Americas and beyond. This will be the second multi-national meeting to promote collaboration among banding programs in the Americas (the first meeting was held in October 8-9, 2006 in La Mancha, Veracruz, Mexico). The Second ?Western Hemisphere Network of Bird Banding Programs

  3. Picosecond thermometer in the amide I band of myoglobin

    DEFF Research Database (Denmark)

    Austin, R.H.; Xie, A.; Meer, L. van der


    The amide I and II bands in myoglobin show a heterogeneous temperature dependence, with bands at 6.17 and 6.43 mu m which are more intense at low temperatures. The amide I band temperature dependence is on the long wavelength edge of the band, while the short wavelength side has almost...... can be used to determine the time it takes vibrational energy to flow into the hydration shell. We determine that vibrational energy flow to the hydration shell from the amide I takes approximately 20 ps to occur....

  4. 14/12-GHz-band satellite communication services (United States)

    Hayashi, Kunihiro; Nagaki, Kiyoaki; Mori, Yasuo


    Three new systems for integrated TV-relay services have been developed: Satellite Video Comunication Service (SVCS) and Satellite Digital Communication Service (SDCS), with Japan's 14/12-GHz-band commercial communication satellites. These systems have been in commercial use since May 1989. Usually SVCS and SDCS have been provided using Ka-band (30/20 GHz-band) of CS-2 and Cs-3. This paper provides an overview of the design, the performance, and the systems of the new 14/12-GHz-band satellite communication services.

  5. Diluted II-VI Oxide Semiconductors with Multiple Band Gaps


    Yu, K.M.; Walukiewicz, W.; Wu, J; Shan, W.; Beeman, J. W.; Scarpulla, M. A.; Dubon, O. D.; Becla, P.


    We report the realization of a new multi-band-gap semiconductor. The highly mismatched alloy Zn1-yMnyOxTe1-x has been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn1-yMnyTe host. When only 1.3% of Te atoms is replaced with oxygen in a Zn0.88Mn0.12Te crystal (with band gap of 2.32 eV) the r...

  6. Band structure, band offsets, substitutional doping, and Schottky barriers of bulk and monolayer InSe (United States)

    Guo, Yuzheng; Robertson, John


    We present a detailed study of the electronic structure of the layered semiconductor InSe. We calculate the band structure of the monolayer and bulk material using density functional theory, hybrid functionals, and G W . The band gap of the monolayer InSe is calculated to be 2.4 eV in screened exchange hybrid functional, close to the experimental photoluminescence gap. The electron affinities and band offsets are calculated for vertical stacked-layer heterostructures, and are found to be suitable for tunnel field effect transistors (TFETs) in combination with WS e2 or similar. The valence-band edge of InSe is calculated to lie 5.2 eV below the vacuum level, similar to that for the closed shell systems HfS e2 or SnS e2 . Hence InSe would be suitable to act as a p -type drain in the TFET. The intrinsic defects are calculated. For Se-rich layers, the Se adatom (interstitial) is found to be the most stable defect, whereas for In-rich layers, the Se vacancy is the most stable for the neutral state. Antisites tend to have energies just above those of vacancies. The Se antisite distorts towards a bond-breaking distortion as in the EL2 center of GaAs. Both substitutional donors and acceptors are calculated to be shallow, and effective dopants. They do not reconstruct to form nondoping configurations as occurs in black phosphorus. Finally, the Schottky barriers of metals on InSe are found to be strongly pinned by metal induced gap states (MIGS) at ˜0.5 eV above the valence-band edge. Any interfacial defects would lead to a stronger pinning at a similar energy. Overall, InSe is an effective semiconductor combining the good features of 2D (lack of dangling bonds, etc.) with the good features of 3D (effective doping), which few others achieve.

  7. Vowel categorization and the critical band. (United States)

    Weitzman, R S


    Using the concept formation paradigm, two series of experiments were conducted to test the hypothesis that the critical band (CB) was a factor in learning to make absolute discriminations of vowels. The specific hypothesis being examined was that the CB is a psychoacoustic boundary in learning to make vowel categorizations, and that learning absolute discriminations of pairs of vowels that differ in one of their formants by one bark or more is significantly easier than learning absolute discriminations of vowels that differ by less than one bark. Subjects were given the task of learning to identify paired sets of synthesized vowels that differed in either F1 or F2 by 0.4, 0.6, 0.8, 1.0, or 1.2 bark. The results of these experiments suggest that the critical bandwidth is not a natural psychoacoustic boundary in the learning of vowel categories, and also that subjects seem better able to learn distinctions involving differences in F1 than distinctions involving differences in F2. The discussion raises the possibility that vowels that differ by less than one bark may not be perceptually viable because of such factors as ambient noise, articulatory constraints, and coarticulatory influences. Some evidence from Dutch and French is presented in support of this conjecture.

  8. Anechoic chamber for VHF and UHF bands (United States)

    Morikawa, Takao; Sugiura, Akira; Harima, Katsushige; Masuzawa, Hiroshi


    Built in 1969, the anechoic chamber of CRL has been used to the fullest by researchers in many fields such as EMI, EMC, antenna design, standard of electric field intensity, and type approval testing. In particular, in the early days of space development in Japan, many satellite-born antennas were developed in this anechoic chamber. However, a quarter of a century has passed since its construction and deteriorated performance due to superannuation sometimes caused difficulties in experiments conducted in the chamber. In 1993, CRL constructed a Measuring Facility for Radio Research (MFRR) and the anechoic chamber for VHF-UHF bands was remodeled as one of the sub-facilities of MFRR. The remodeling work included full replacement of the electromagnetic shielding, absorbers and measurement system. Since the remodeled anechoic chamber is being used not only for EMI tests but also for other purposes, a full-anechoic chamber has been adopted. In addition the chamber has been designed for the frequency range between 30 MHz and 10 GHz. After the remodeling work, the performance of the chamber is greatly improved. The average shielding factor is better than 85 dB for all frequency ranges and the unwanted reflection characteristic is -30 dB for frequencies above 1 GHZ. This paper summarizes the remodeling work, and the specifications and performance of the remodeled anechoic chamber.

  9. Annual Growth Bands in Hymenaea courbaril

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, J A; Guilderson, T P; Colinvaux, P A


    One significant source of annual temperature and precipitation data arises from the regular annual secondary growth rings of trees. Several tropical tree species are observed to form regular growth bands that may or may not form annually. Such growth was observed in one stem disk of the tropical legume Hymenaea courbaril near the area of David, Panama. In comparison to annual reference {Delta}{sup 14}C values from wood and air, the {Delta}{sup 14}C values from the secondary growth rings formed by H. courbaril were determined to be annual in nature in this one stem disk specimen. During this study, H. courbaril was also observed to translocate recently produced photosynthate into older growth rings as sapwood is converted to heartwood. This process alters the overall {Delta}{sup 14}C values of these transitional growth rings as cellulose with a higher {Delta}{sup 14}C content is translocated into growth rings with a relatively lower {Delta}{sup 14}C content. Once the annual nature of these growth rings is established, further stable isotope analyses on H. courbaril material in other studies may help to complete gaps in the understanding of short and of long term global climate patterns.

  10. Multi-band terahertz metasurface absorber (United States)

    Wang, Xuying; Wang, Qingmin; Dong, Guoyan; Hao, Yanan; Lei, Ming; Bi, Ke


    A terahertz metasurface perfect absorber with multi-band performance is demonstrated. The absorber is composed of a ground plane and four split-ring resonators (SRRs) with different dimensions, separated by a dielectric spacer. The numerical simulation results illustrate that the proposed absorber has four distinct absorption peaks at resonance frequencies of 4.24, 5.66, 7.22, and 8.97 THz, with absorption rates of 96.8%, 99.3%, 97.3%, and 99.9%, respectively. Moreover, the corresponding full width at half-maximum (FWHM) values are about 0.27, 0.35, 0.32, and 0.42 THz, respectively, which are much broader than those of previously reported absorbers. Besides, the calculated magnetic field distributions allow us to understand the absorption mechanism in detail. The effects of incident angle and azimuthal angle on the absorber are also investigated. The results show that the proposed absorber is partially sensitive to the incident angle, which makes this design promising for practical applications in terahertz imagers and detectors.

  11. Vestibular Findings in Military Band Musicians

    Directory of Open Access Journals (Sweden)

    Zeigelboim, Bianca Simone


    Full Text Available Introduction Exposure to music is the subject of many studies because it is related to an individual's professional and social activities. Objectives Evaluate the vestibular behavior in military band musicians. Methods A retrospective cross-sectional study was performed. Nineteen musicians with ages ranging from 21 to 46 years were evaluated (average = 33.7 years and standard deviation = 7.2 years. They underwent anamnesis and vestibular and otolaryngologic evaluation through vectoelectronystagmography. Results The most evident otoneurologic symptoms in the anamnesis were tinnitus (84.2%, hearing difficulties (47.3%, dizziness (36.8%, headache (26.3%, intolerance to intense sounds (21.0%, and earache (15.7%. Seven musicians (37.0% showed vestibular abnormality, which occurred in the caloric test. The abnormality was more prevalent in the peripheral vestibular system, and there was a predominance of irritative peripheral vestibular disorders. Conclusion The alteration in vestibular exam occurred in the caloric test (37.0%. There were changes in the prevalence of peripheral vestibular system with a predominance of irritative vestibular dysfunction. Dizziness was the most significant symptom for the vestibular test in correlation with neurotologic symptoms. The present study made it possible to verify the importance of the labyrinthine test, which demonstrates that this population should be better studied because the systematic exposure to high sound pressure levels may cause major vestibular alterations.

  12. Vestibular findings in military band musicians. (United States)

    Zeigelboim, Bianca Simone; Gueber, Crislaine; Silva, Thanara Pruner da; Liberalesso, Paulo Breno Noronha; Gonçalves, Claudia Giglio de Oliveira; Faryniuk, João Henrique; Marques, Jair Mendes; Jurkiewicz, Ari Leon


    Introduction Exposure to music is the subject of many studies because it is related to an individual's professional and social activities. Objectives Evaluate the vestibular behavior in military band musicians. Methods A retrospective cross-sectional study was performed. Nineteen musicians with ages ranging from 21 to 46 years were evaluated (average = 33.7 years and standard deviation = 7.2 years). They underwent anamnesis and vestibular and otolaryngologic evaluation through vectoelectronystagmography. Results The most evident otoneurologic symptoms in the anamnesis were tinnitus (84.2%), hearing difficulties (47.3%), dizziness (36.8%), headache (26.3%), intolerance to intense sounds (21.0%), and earache (15.7%). Seven musicians (37.0%) showed vestibular abnormality, which occurred in the caloric test. The abnormality was more prevalent in the peripheral vestibular system, and there was a predominance of irritative peripheral vestibular disorders. Conclusion The alteration in vestibular exam occurred in the caloric test (37.0%). There were changes in the prevalence of peripheral vestibular system with a predominance of irritative vestibular dysfunction. Dizziness was the most significant symptom for the vestibular test in correlation with neurotologic symptoms. The present study made it possible to verify the importance of the labyrinthine test, which demonstrates that this population should be better studied because the systematic exposure to high sound pressure levels may cause major vestibular alterations.

  13. An ultrathin dual-band metamaterial absorber (United States)

    Zhang, Yong; Duan, Junping; Zhang, Wendong; Wang, Wanjun; Zhang, Binzhen


    The design and preparation of an ultrathin dual-band metamaterial absorber whose resonant frequency located at radar wave (20 GHz-60 GHz) is presented in this paper. The absorber is composed of a 2-D periodic sandwich featured with two concentric annuluses. The influence on the absorber's performance produced by resonant cell's structure size and material parameters was numerically simulated and analyzed based on the standard full wave finite integration technology in CST. Laser ablation process was adopted to prepare the designed absorber on epoxy resin board coated with on double plane of copper with a thickness that is 1/30 and 1/50 of the resonant wavelength at a resonant frequency of 30.51 GHz and 48.15 GHz. The full width at half maximum (FWHM) reached 2.2 GHz and 2.35 GHz and the peak of the absorptance reached 99.977%. The ultrathin absorber is nearly omnidirectional for all polarizations. The test results of prepared sample testify the designed absorber's excellent absorbing performance forcefully. The absorber expands inspirations of radar stealth in military domain due to its flexible design, cost-effective and other outstanding properties.

  14. Vertical gastroplasty: evolution of vertical banded gastroplasty. (United States)

    Mason, E E; Doherty, C; Cullen, J J; Scott, D; Rodriguez, E M; Maher, J W


    The objective of this paper is to summarize the goals, technical requirements, advantages, and potential risks of gastroplasty for treatment of severe obesity. Gastroplasty is preferred to more complex operations, as it preserves normal digestion and absorption and avoids complications that are peculiar to exclusion operations. The medical literature and a 30-year experience at the University of Iowa Hospitals and Clinics (UIHC) provides an overview of vertical banded gastroplasty (VBG) evolution. Preliminary 10-year results with the VBG technique currently used at UIHC are included. At UIHC the VBG is preferred to other gastroplasties because it provides weight control that extends for at least 10 years and the required objective, intraoperative quality control required for a low rate of reoperation. It is recommended that modifications of the operative technique not be attempted until a surgeon has had experience with the standardized operation--and then only under a carefully designed protocol. Realistic goals for surgery and criteria of success influence the choice of operation and the optimum, lifelong risk/benefit ratio. In conclusion, VBG is a safe, long-term effective operation for severe obesity with advantages over complex operations and more restrictive simple operations.

  15. Grain size dependent optical band gap of CdI2 films

    Indian Academy of Sciences (India)


    direct band gap in conformity with band structure calcula- tions. However, a smaller indirect band gap can also be determined from part of absorption data near the band edge for the purpose of comparison with earlier analyses of absorption data as well as the band structure calcula- tions. The decreasing band gap with film ...

  16. Sharpening the VNIR and SWIR Bands of Sentinel-2A Imagery through Modified Selected and Synthesized Band Schemes

    Directory of Open Access Journals (Sweden)

    Honglyun Park


    Full Text Available In this work, the bands of a Sentinel-2A image with spatial resolutions of 20 m and 60 m are sharpened to a spatial resolution of 10 m to obtain visible and near-infrared (VNIR and shortwave infrared (SWIR spectral bands with a spatial resolution of 10 m. In particular, we propose a two-step sharpening algorithm for Sentinel-2A imagery based on modified, selected, and synthesized band schemes using layer-stacked bands to sharpen Sentinel-2A images. The modified selected and synthesized band schemes proposed in this study extend the existing band schemes for sharpening Sentinel-2A images with spatial resolutions of 20 m and 60 m to improve the pan-sharpening accuracy by changing the combinations of bands used for multiple linear regression analysis through band-layer stacking. The proposed algorithms are applied to the pan-sharpening algorithm based on component substitution (CS and a multiresolution analysis (MRA, and our results are then compared to the sharpening results when using sharpening algorithms based on existing band schemes. The experimental results show that the sharpening results from the proposed algorithm are improved in terms of the spatial and spectral properties when compared to existing methods. However, the results of the sharpening algorithm when applied to our modified band schemes show differing tendencies. With the modified, selected band scheme, the sharpening result when applying the CS-based algorithm is higher than the result when applying the MRA-based algorithm. However, the quality of the sharpening results when using the MRA-based algorithm with the modified synthesized band scheme is higher than that when using the CS-based algorithm.

  17. Model development for MODIS thermal band electronic cross-talk (United States)

    Chang, Tiejun; Wu, Aisheng; Geng, Xu; Li, Yonghong; Brinkmann, Jake; Keller, Graziela; Xiong, Xiaoxiong (Jack)


    MODerate-resolution Imaging Spectroradiometer (MODIS) has 36 bands. Among them, 16 thermal emissive bands covering a wavelength range from 3.8 to 14.4 μm. After 16 years on-orbit operation, the electronic crosstalk of a few Terra MODIS thermal emissive bands develop substantial issues which cause biases in the EV brightness temperature measurements and surface feature contamination. The crosstalk effects on band 27 with center wavelength at 6.7 μm and band 29 at 8.5 μm increased significantly in recent years, affecting downstream products such as water vapor and cloud mask. The crosstalk issue can be observed from nearly monthly scheduled lunar measurements, from which the crosstalk coefficients can be derived. Most of MODIS thermal bands are saturated at moon surface temperatures and the development of an alternative approach is very helpful for verification. In this work, a physical model was developed to assess the crosstalk impact on calibration as well as in Earth view brightness temperature retrieval. This model was applied to Terra MODIS band 29 empirically for correction of Earth brightness temperature measurements. In the model development, the detector nonlinear response is considered. The impacts of the electronic crosstalk are assessed in two steps. The first step consists of determining the impact on calibration using the on-board blackbody (BB). Due to the detector nonlinear response and large background signal, both linear and nonlinear coefficients are affected by the crosstalk from sending bands. The crosstalk impact on calibration coefficients was calculated. The second step is to calculate the effects on the Earth view brightness temperature retrieval. The effects include those from affected calibration coefficients and the contamination of Earth view measurements. This model links the measurement bias with crosstalk coefficients, detector nonlinearity, and the ratio of Earth measurements between the sending and receiving bands. The correction

  18. Terra MODIS Band 27 Electronic Crosstalk Effect and Its Removal (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Madhavan, Sriharsha; Wenny, Brian


    The MODerate-resolution Imaging Spectroradiometer (MODIS) is one of the primary instruments in the NASA Earth Observing System (EOS). The first MODIS instrument was launched in December, 1999 on-board the Terra spacecraft. MODIS has 36 bands, covering a wavelength range from 0.4 micron to 14.4 micron. MODIS band 27 (6.72 micron) is a water vapor band, which is designed to be insensitive to Earth surface features. In recent Earth View (EV) images of Terra band 27, surface feature contamination is clearly seen and striping has become very pronounced. In this paper, it is shown that band 27 is impacted by electronic crosstalk from bands 28-30. An algorithm using a linear approximation is developed to correct the crosstalk effect. The crosstalk coefficients are derived from Terra MODIS lunar observations. They show that the crosstalk is strongly detector dependent and the crosstalk pattern has changed dramatically since launch. The crosstalk contributions are positive to the instrument response of band 27 early in the mission but became negative and much larger in magnitude at later stages of the mission for most detectors of the band. The algorithm is applied to both Black Body (BB) calibration and MODIS L1B products. With the crosstalk effect removed, the calibration coefficients of Terra MODIS band 27 derived from the BB show that the detector differences become smaller. With the algorithm applied to MODIS L1B products, the Earth surface features are significantly removed and the striping is substantially reduced in the images of the band. The approach developed in this report for removal of the electronic crosstalk effect can be applied to other MODIS bands if similar crosstalk behaviors occur.

  19. Ultra-thin narrow-band, complementary narrow-band, and dual-band metamaterial absorbers for applications in the THz regime (United States)

    Astorino, Maria Denise; Frezza, Fabrizio; Tedeschi, Nicola


    In this paper, ultra-thin narrow-band, complementary narrow-band, and dual-band metamaterial absorbers (MMAs), exploiting the same electric ring resonator configuration, are investigated at normal and oblique incidence for both transverse electric (TE) and transverse magnetic (TM) polarizations, and with different physical properties in the THz regime. In the analysis of the ultra-thin narrow-band MMA, the limit of applicability of the transmission line model has been overcome with the introduction of a capacitance which considers the z component of the electric field. These absorbing structures have shown a wide angular response and a polarization-insensitive behavior due to the introduction of a conducting ground plane and to the four-fold rotational symmetry of the resonant elements around the propagation axis. We have adopted a retrieval procedure to extract the effective electromagnetic parameters of the proposed MMAs and we have compared the simulated and analytical results through the interference theory.

  20. A six-pole narrow-band high temperature superconducting filter with wide stop-band response at P-band (United States)

    Gong, Liming; Wei, Bin; Zhang, Ying; Zhang, Xiaoping; Guo, Xubo; Zhang, Guoyong; Cao, Bisong


    A quarter-wavelength stepped impedance resonator (QWSIR) is proposed for high temperature superconducting (HTS) filter, offering wide stop-band performance. A six-pole P-band HTS filter with QWSIRs was designed and fabricated. The filter has a fractional bandwidth of 0.8% at 516 MHz and shows the lowest spurious frequency at about 2.15 GHz. The measured results of the HTS filter are in good agreement with simulations.

  1. Breeding biology and diet of Banded Kestrels Falco zoniventris on ...

    African Journals Online (AJOL)

    We studied the breeding biology of the Banded Kestrel (Falco zoniventris) in the forest edge habitat of Masoala Peninsula of north-eastern Madagascar from 1997 to 1999. Banded Kestrels begin their breeding season at the end of the wet season during August and the start of the dry season in September. Courtship began ...

  2. Deexcitation of superdeformed bands in the nucleus Tb-151

    NARCIS (Netherlands)

    Finck, C; Appelbe, D; Beck, FA; Byrski, T; Cullen, D; Curien, D; deFrance, G; Duchene, G; Erturk, S; Haas, B; Khadiri, N; Kharraja, B; Prevost, D; Rigollet, C; Stezowski, O; Twin, P; Vivien, JP; Zuber, K


    The aim of this work is to get more informations about the decay-out of superdeformed bands. One of the best candidates in the mass A similar or equal to 150 region for that kind of research is the nucleus Tb-151. From previous works, it has been established that the first excited band goes lower in

  3. 75 FR 75813 - Unlicensed Operation in the TV Broadcast Bands (United States)


    ... TV bands devices. The Commission observes that there are a wide variety of applications for wireless... Engineering and Technology and Wireless Telecommunications Bureaus. 17. The Commission is maintaining the... in the TV bands available for unlicensed broadband wireless devices. This particular spectrum has...

  4. 77 FR 33098 - Unlicensed Operation in the TV Broadcast Band (United States)


    ... COMMISSION 47 CFR Part 15 Unlicensed Operation in the TV Broadcast Band AGENCY: Federal Communications... Memorandum Opinion and Order, in the matter of ``Unlicensed Operation in the TV Broadcast Band Approval... final regulations that are the subject of this correction relate to ``Unlicensed Operation in the TV...

  5. Effects of band-limited noise on human observer performance

    NARCIS (Netherlands)

    Salem, S.; Jacobs, E.; Moore, R.; Hogervorst, M.A.; Bijl, P.


    Perception tests establish the effects of spatially band-limited noise and blur on human observer performance. Previously, Bijl showed that the contrast threshold of a target image with spatially band-limited noise is a function of noise spatial frequency. He used the method of adjustment to find

  6. Evaluation of a color fused dual-band NVG

    NARCIS (Netherlands)

    Hogervorst, M.A.; Toet, A.


    We designed and evaluated a dual-band Night Vision Goggles sensor system. The sensor system consists of two optically aligned NVGs fitted with filters splitting the sensitive range into a visual and a near-infrared band. The Color-the-night technique (Hogervorst & Toet, FUSION2008) was used to fuse

  7. Evaluation of a color fused dual-band NVG

    NARCIS (Netherlands)

    Hogervorst, M.A.; Toet, A.


    We have tested a prototype dual-band NVG system consisting of two NVGs fitted with filters that split the NVG sensitive range into a short (visual) and a long wavelength (NIR) band. The Color-the-night technique (see Hogervorst & Toet, SPIE D&S ‘08) was used to fuse the images of the two sensors. We

  8. Band excitation method applicable to scanning probe microscopy (United States)

    Jesse, Stephen [Knoxville, TN; Kalinin, Sergei V [Knoxville, TN


    Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

  9. 77 FR 45558 - 4.9 GHz Band (United States)


    .... Currently, all classes of operations in the 4.9 GHz band, such as base, mobile, and fixed operations, are able to co-exist on one license. Station class codes differentiate the various classes. One participant... public safety mobile broadband spectrum particularly for offloading video.'' Since the 4.9 GHz band has a...

  10. Macroeconomic stabilization and intervention policy under an exchange rate band

    NARCIS (Netherlands)

    Beetsma, R.M.W.J.; van der Ploeg, F.


    Macroeconomic stabilization and foreign exchange market interventions are investigated for a small open economy with a nominal exchange rate band. In a first-best situation, a band is not advisable from a stabilization perspective, even though with money demand shocks no welfare losses are incurred.

  11. Photonic band-gap optimisation in inverted FCC photonic crystals

    NARCIS (Netherlands)

    Doosje, M; Hoenders, BJ; Knoester, J; Lenstra, D; Visser, TD; Leeuwen, KAH


    We present results of band-structure calculations for inverted photonic crystal structures. We consider a structure of air spheres in a dielectric background, arranged in an FCC lattice, with cylindrical tunnels connecting each pair of neighbouring spheres. The width of the band gap is optimised by

  12. Electronic band structure of PuCoGa sub 5

    CERN Document Server

    Szajek, A


    The electronic band structure is presented for PuCoGa sub 5 , the recently discovered superconductor with T sub C approx 18 K. The band structure is calculated by the tight-binding linear muffin-tin orbital method in the atomic sphere approximation. (letter to the editor)

  13. Determination of conduction and valence band electronic structure ...

    Indian Academy of Sciences (India)

    Electronic structures of rutile and anatase polymorph of TiO2 were determined by resonant inelastic X-ray scattering measurements and FEFF9.0 calculations. Difference between crystalline structures led to shifts in the rutile Ti -band to lower energy with respect to anatase, i.e., decrease in band gap. Anatase possesses ...

  14. Band structure engineered layered metals for low-loss plasmonics

    DEFF Research Database (Denmark)

    Gjerding, Morten Niklas; Pandey, Mohnish; Thygesen, Kristian Sommer


    dichalcogenide TaS2, due to an extraordinarily small density of states for scattering in the near-IR originating from their special electronic band structure. On the basis of this observation, we propose a new class of band structure engineered van der Waals layered metals composed of hexagonal transition metal...

  15. Steel Band Repertoire: The Case for Original Music (United States)

    Tanner, Chris


    In the past few decades, the steel band art form has experienced consistent growth and development in several key respects. For example, in the United States, the sheer number of steel band programs has steadily increased, and it appears that this trend will continue in the future. Additionally, pan builders and tuners have made great strides in…

  16. K-Band Traveling-Wave Tube Amplifier (United States)

    Force, Dale A.; Simons, Rainee N.; Peterson, Todd T.; Spitsen, Paul C.


    A new space-qualified, high-power, high-efficiency, K-band traveling-wave tube amplifier (TWTA) will provide high-rate, high-capacity, direct-to-Earth communications for science data and video gathered by the Lunar Reconnaissance Orbiter (LRO) during its mission. Several technological advances were responsible for the successful demonstration of the K-band TWTA.

  17. Narrow-Band Clutter Mitigation in Spectral Polarimetric Weather Radar

    NARCIS (Netherlands)

    Yin, J.; Unal, C.M.H.; Russchenberg, H.W.J.


    In this paper, a new clutter suppression method, named the moving double spectral linear depolarization ratio (MDsLDR) filter, is put forward to mitigate narrow-band clutter in weather radars. The narrow-band clutter observed in the Doppler domain includes: 1) stationary clutter such as ground

  18. 5 CFR 9901.212 - Pay schedules and pay bands. (United States)


    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Pay schedules and pay bands. 9901.212... SECURITY PERSONNEL SYSTEM (NSPS) Classification Classification Structure § 9901.212 Pay schedules and pay bands. (a) For purposes of identifying relative levels of work and corresponding pay ranges, the...

  19. Photonic band gap engineering in 2D photonic crystals

    Indian Academy of Sciences (India)

    of photonic crystals to control electromagnetic radiation, study of photonic band gaps in photonic crystals is a must. The photonic band gaps in photonic crystals depend upon the arrangement of the constituent air holes/dielectric rods, fill factor and dielectric contrast of the two mediums used in forming photonic crystals. In.

  20. Strain gradient drives shear banding in metallic glasses (United States)

    Tian, Zhi-Li; Wang, Yun-Jiang; Chen, Yan; Dai, Lan-Hong


    Shear banding is a nucleation-controlled process in metallic glasses (MGs) involving multiple temporal-spatial scales, which hinders a concrete understanding of its structural origin down to the atomic scale. Here, inspired by the morphology of composite materials, we propose a different perspective of MGs as a hard particle-reinforced material based on atomic-scale structural heterogeneity. The local stable structures indicated by a high level of local fivefold symmetry (L5FS) act as hard "particles" which are embedded in the relatively soft matrix. We demonstrate this concept by performing atomistic simulations of shear banding in CuZr MG. A shear band is prone to form in a sample with a high degree of L5FS which is slowly quenched from the liquid. An atomic-scale analysis on strain and the structural evolution reveals that it is the strain gradient effect that has originated from structural heterogeneity that facilitates shear transformation zones (STZs) to mature shear bands. An artificial composite model with a high degree of strain gradient, generated by inserting hard MG strips into a soft MG matrix, demonstrates a great propensity for shear banding. It therefore confirms the critical role strain gradient plays in shear banding. The strain gradient effect on shear banding is further quantified with a continuum model and a mechanical instability analysis. These physical insights might highlight the strain gradient as the hidden driving force in transforming STZs into shear bands in MGs.

  1. Limitations to band gap tuning in nitride semiconductor alloys

    DEFF Research Database (Denmark)

    Gorczyca, I.; Suski, T.; Christensen, Niels Egede


    Relations between the band gaps of nitride alloys and their lattice parameters are presented and limits to tuning of the fundamental gap in nitride semiconductors are set by combining a large number of experimental data with ab initio theoretical calculations. Large band gap bowings obtained...

  2. Ensemble Organization of the Band of Fela Anikulapo-Kuti ...

    African Journals Online (AJOL)

    EJOTMAS: Ekpoma Journal of Theatre and Media Arts ... Through an in-depth interview with key members of his band that are still alive, the paper considers the administrative styles adopted by Fela Anikulapo Kuti and how present day musicians can also adapt such styles in managing the big band in the 21st century.

  3. How to Make Your Small Band Sound Big! (United States)

    Criswell, Chad


    If one asks many small-town band directors, most will say that working and performing with a small band can be just as satisfying and musically robust as directing a larger one. There are a lot of advantages as well; smaller class sizes, fewer extracurricular activities, and more time to work one on one with students are just a few of the benefits…

  4. Geochemistry of some banded iron-formations of the archean ...

    Indian Academy of Sciences (India)

    Banded iron-formations (BIF) form an important part of the Archean supracrustal belts of the Jharkhand–Orissa region, India. Major, trace and REE chemistry of the banded iron-formation of the Gandhamardan, Deo Nala, Gorumahisani and Noamundi sections of the Jharkhand–Orissa region are utilized to explore the ...

  5. Popular Music Pedagogy: Band Rehearsals at British Universities (United States)

    Pulman, Mark


    There has been little published pedagogical research on popular music group rehearsing. This study explores the perceptions of tutors and student pop/rock bands about the rehearsals in which they were involved as a part of their university music course. The participants were 10 tutors and 16 bands from eight British tertiary institutions. Analysis…

  6. New face-centered photonic square lattices with flat bands

    CERN Document Server

    Zhang, Yiqi; Li, Changbiao; Zhang, Zhaoyang; Zhang, Yanpeng; Xiao, Min


    We report two new classes of face-centered photonic square lattices with flat bands which we call the Lieb-I and the Lieb-II lattices. There are 5 and 7 sites in the corresponding unit cells of the simplest Lieb-I and Lieb-II lattices, respectively. The number of flat bands $m$ in the new Lieb lattices is related to the number of sites $N$ in the unit cell by $m=(N-1)/2$. Physical properties of the lattices with even and odd number of flat bands are different. We also consider localization of light in such Lieb lattices. If the input beam excites the flat-band mode, it will not diffract during propagation, owing to the strong localization in the flat-band mode. For the Lieb-II lattice, we also find that the beam will oscillate and still not diffract during propagation, because of the intrinsic oscillating properties of certain flat-band modes. The period of oscillation is determined by the energy difference between the two flat bands. This study provides a new platform for the investigation of flat-band modes...

  7. Bands in the spectrum of a periodic elastic waveguide (United States)

    Bakharev, F. L.; Taskinen, J.


    We study the spectral linear elasticity problem in an unbounded periodic waveguide, which consists of a sequence of identical bounded cells connected by thin ligaments of diameter of order h >0. The essential spectrum of the problem is known to have band-gap structure. We derive asymptotic formulas for the position of the spectral bands and gaps, as h → 0.

  8. Non-equilibrium and band tailing in organic conductors

    Indian Academy of Sciences (India)

    Band tailing; organic conductors; IR spectra; electrical resistivity. Abstract. The concept of band tailing with focal point and width of the tail from IR absorption spectra of different organic conductors is found valid even for thermal and elastic changes. The experimental situations like change of solvents, method of preparation, ...

  9. Dual-band dual-polarized array for WLAN applications

    CSIR Research Space (South Africa)

    Steyn, JM


    Full Text Available ) simultaneously. The two linear polarizations have separate ports. The presented design is characterized by dual-band operation, reasonably good front-to-back ratios, average gains of 5.2 dBi and 6.2 dBi over the 2.4 and 5.2 GHz bands respectively, stable end...

  10. Polarization diverse antenna for dual-band WLAN applications

    CSIR Research Space (South Africa)

    Steyn, JM


    Full Text Available A dual-band dual-polarized (DBDP) configuration is proposed for wireless local area network (WLAN) applications. A four-element array is used to facilitate operation in both the standard WLAN frequency bands (IEEE 802.11b and IEEE 802.11a...

  11. Banding of seabirds in the Southern Ocean has been undertaken ...

    African Journals Online (AJOL)


    and the South African Prince Edward Islands, 1 068 km apart in the Southern Ocean. Most movements of banded birds (57) have ... two, one of which was dead, at Prince Edward Island). Age-class at banding is unknown for one .... Exclusive Economic Zones (EEZs), perhaps by way of a joint Plan of Action (FAO 2001); ...

  12. Assessment of Multipath and Shadowing Effects on UHF Band in ...

    African Journals Online (AJOL)


    3Department of Information and Communication Science, University of florin. Abstract. Ultra-high frequency (UHF) bands are ... Radio propagation, Terrain features. ATBU Journal of Environmental Technology 10, 1, June 2017. Page 2. Assessment of Multipath and Shadowing Effects on UHF Band in Built-Up Environments.

  13. A simultaneous confidence band for sparse longitudinal regression

    KAUST Repository

    Ma, Shujie


    Functional data analysis has received considerable recent attention and a number of successful applications have been reported. In this paper, asymptotically simultaneous confidence bands are obtained for the mean function of the functional regression model, using piecewise constant spline estimation. Simulation experiments corroborate the asymptotic theory. The confidence band procedure is illustrated by analyzing CD4 cell counts of HIV infected patients.

  14. 5 CFR 9701.344 - Special within-band increases. (United States)


    ... increases for employees within a Full Performance or higher band established under § 9701.212 who possess... other circumstances determined by DHS. Increases under this section are in addition to any performance... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Special within-band increases. 9701.344...

  15. Spectral band discrimination for species observed from hyperspectral remote sensing

    CSIR Research Space (South Africa)

    Dudeni, N


    Full Text Available to assess whether various sets of bands including the full spectrum, the visible (VIS), the near infrared (NIR), the shortwave infra-red (SWIR) region, as well as sets of bands identified by the stepwise discriminant analysis (SDA), can be used...

  16. Diluted II-VI oxide semiconductors with multiple band gaps. (United States)

    Yu, K M; Walukiewicz, W; Wu, J; Shan, W; Beeman, J W; Scarpulla, M A; Dubon, O D; Becla, P


    We report the realization of a new mult-band-gap semiconductor. Zn(1-y)Mn(y)OxTe1-x alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn(1-y)Mn(y)Te host. When only 1.3% of Te atoms are replaced with oxygen in a Zn0.88Mn0.12Te crystal the resulting band structure consists of two direct band gaps with interband transitions at approximately 1.77 and 2.7 eV. This remarkable modification of the band structure is well described by the band anticrossing model. With multiple band gaps that fall within the solar energy spectrum, Zn(1-y)Mn(y)OxTe1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.

  17. A novel L-band polarimetric radiometer featuring subharmonic sampling

    DEFF Research Database (Denmark)

    Rotbøll, J.; Søbjærg, Sten Schmidl; Skou, Niels


    A novel L-band radiometer trading analog components for digital circuits has been designed, built and operated. It is a fully polarimetric radiometer of the correlation type, and it is based on the subharmonic sampling principle in which the L-band signal is directly sampled by a fast A to D...

  18. L-Band Polarimetric Correlation Radiometer with Subharmonic Sampling

    DEFF Research Database (Denmark)

    Rotbøll, Jesper; Søbjærg, Sten Schmidl; Skou, Niels


    A novel L-band radiometer trading analog complexity for digital ditto has been designed and built. It is a fully polarimetric radiometer of the correlation type and it is based on the sub-harmonic sampling principle in which the L-band signal is directly sampled by a fast A to D converter...

  19. A novel endoscopic fluorescent band ligation method for tumor localization. (United States)

    Hyun, Jong Hee; Kim, Seok-Ki; Kim, Kwang Gi; Kim, Hong Rae; Lee, Hyun Min; Park, Sunup; Kim, Sung Chun; Choi, Yongdoo; Sohn, Dae Kyung


    Accurate tumor localization is essential for minimally invasive surgery. This study describes the development of a novel endoscopic fluorescent band ligation method for the rapid and accurate identification of tumor sites during surgery. The method utilized a fluorescent rubber band, made of indocyanine green (ICG) and a liquid rubber solution mixture, as well as a near-infrared fluorescence laparoscopic system with a dual light source using a high-powered light-emitting diode (LED) and a 785-nm laser diode. The fluorescent rubber bands were endoscopically placed on the mucosae of porcine stomachs and colons. During subsequent conventional laparoscopic stomach and colon surgery, the fluorescent bands were assayed using the near-infrared fluorescence laparoscopy system. The locations of the fluorescent clips were clearly identified on the fluorescence images in real time. The system was able to distinguish the two or three bands marked on the mucosal surfaces of the stomach and colon. Resection margins around the fluorescent bands were sufficient in the resected specimens obtained during stomach and colon surgery. These novel endoscopic fluorescent bands could be rapidly and accurately localized during stomach and colon surgery. Use of these bands may make possible the excision of exact target sites during minimally invasive gastrointestinal surgery.

  20. Differential effects of gastric bypass and banding on the ...

    African Journals Online (AJOL)

    Hala Mourad Demerdash


    Sep 1, 2012 ... Abstract Background: Weight loss (5–10%) improves obesity-associated cardiovascular risk factors. The aim of this work was to study the effect of 2 commonly performed bariatric surgical procedures; laparoscopic Roux-en-Y gastric bypass (RYGBP) and laparoscopic gastric band. (BAND), on the ...

  1. Differential effects of gastric bypass and banding on the ...

    African Journals Online (AJOL)

    Background: Weight loss (5–10%) improves obesity-associated cardiovascular risk factors. The aim of this work was to study the effect of 2 commonly performed bariatric surgical procedures; laparoscopic Roux-en-Y gastric bypass (RYGBP) and laparoscopic gastric band (BAND), on the cardiovascular risk profile in ...

  2. Gastroscopic treatment of gastric band penetrating the gastric wall

    DEFF Research Database (Denmark)

    Jess, Per; Fonnest, G


    Gastric wall penetration of a gastric band after operation for morbid obesity is a well known late complication. The treatment is usually reoperation. In this case report we show that a band penetrating the gastric wall can be successfully treated by gastroscopic operation. This technique is more...

  3. The influence of laparoscopic adjustable gastric banding on gastroesophageal reflux

    NARCIS (Netherlands)

    de Jong, [No Value; van Ramshorst, B; Timmer, R; Gooszen, HG; Smout, AJPM

    Background: Laparoscopic adjustable gastric banding (LAGB) influences gastroesophageal reflux. Methods: 26 patients undergoing gastric banding were assessed by a questionnaire for symptom analysis, 24-hour pH monitoring, endoscopy and barium swallows, preoperatively, at 6 weeks and at 6 months after

  4. Superlattice Intermediate Band Solar Cell on Gallium Arsenide (United States)


    AFRL-RV-PS- AFRL-RV-PS- TR-2015-0048 TR-2015-0048 SUPERLATTICE INTERMEDIATE BAND SOLAR CELL ON GALLIUM ARSENIDE Alexandre Freundlich...SUBTITLE 5a. CONTRACT NUMBER FA9453-13-1-0232 Superlattice Intermediate Band Solar Cell on Gallium Arsenide 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  5. The width of Liesegang bands: A study using moving boundary ...

    Indian Academy of Sciences (India)

    Abstract. The pattern formation in reaction–diffusion systems was studied by invoking the pro- visions contained in the moving boundary model. The model claims that the phase separation mechanism is responsible for separating the colloidal phase of precipitants into band and non-band regions. The relation between the ...

  6. Tension band wiring fi xation is associated with good functional ...

    African Journals Online (AJOL)

    Background: Tension band wiring (TBW) is a widely accepted technique for olecranon fractures. Various investigators have reported a significant rate of complications especially hardware prominence. The purpose of this study was to determine the clinical and radiological outcome after tension band wiring of olecranon ...

  7. TRES survey of variable diffuse interstellar bands (United States)

    Law, Charles J.; Milisavljevic, Dan; Crabtree, Kyle N.; Johansen, Sommer L.; Patnaude, Daniel J.; Margutti, Raffaella; Parrent, Jerod T.; Drout, Maria R.; Sanders, Nathan E.; Kirshner, Robert P.; Latham, David W.


    Diffuse interstellar bands (DIBs) are absorption features commonly observed in optical/near-infrared spectra of stars and thought to be associated with polyatomic molecules that comprise a significant reservoir of organic material in the Universe. However, the central wavelengths of almost all DIBs do not correspond with electronic transitions of known atomic or molecular species and the specific physical nature of their carriers remains inconclusive despite decades of observational, theoretical and experimental research. It is well established that DIB carriers are located in the interstellar medium, but the recent discovery of time-varying DIBs in the spectra of the extragalactic supernova SN 2012ap suggests that some may be created in massive star environments. Here, we report evidence of short time-scale (∼10-60 d) changes in DIB absorption line substructure towards 3 of 17 massive stars observed as part of a pathfinder survey of variable DIBs conducted with the 1.5-m Tillinghast telescope and Tillinghast Reflector Echelle Spectrograph (TRES) at Fred L. Whipple Observatory. The detections are made in high-resolution optical spectra (R ∼ 44 000) having signal-to-noise ratios of 5-15 around the 5797 and 6614 Å features, and are considered significant but requiring further investigation. We find that these changes are potentially consistent with interactions between stellar winds and DIB carriers in close proximity. Our findings motivate a larger survey to further characterize these variations and may establish a powerful new method for probing the poorly understood physical characteristics of DIB carriers.

  8. The melting of subducted banded iron formations (United States)

    Kang, Nathan; Schmidt, Max W.


    Banded iron formations (BIF) were common shelf and ocean basin sediments 3.5-1.8 Ga ago. To understand the fate of these dense rocks upon subduction, the melting relations of carbonated BIF were determined in Fe-Ca-(Mg)-Si-C-O2 at 950-1400 °C, 6 and 10 GPa, oxidizing (fO2 = hematite-magnetite, HM) and moderately reducing (fO2 ∼CO2-graphite/diamond, CCO) conditions. Solidus temperatures under oxidizing conditions are 950-1025 °C with H2O, and 1050-1150 °C anhydrous, but 250-175 °C higher at graphite saturation (values at 6-10 GPa). The combination of Fe3+ and carbonate leads to a strong melting depression. Solidus curves are steep with 17-20 °C/GPa. Near-solidus melts are ferro-carbonatites with ∼22 wt.% FeOtot, ∼48 wt% CO2 and 1-5 wt.% SiO2 at fO2 ∼ HM and ∼49 wt.% FeOtot, ∼20 wt% CO2 and 19-25 wt.% SiO2 at fO2 ∼ CCO . At elevated subduction geotherms, as likely for the Archean, C-bearing BIF could melt out all carbonate around 6 GPa. Fe-rich carbonatites would rise but stagnate gravitationally near the slab/mantle interface until they react with the mantle through Fe-Mg exchange and partial reduction. The latter would precipitate diamond and yield Fe- and C-rich mantle domains, yet, Fe-Mg is expected to diffusively re-equilibrate over Ga time scales. We propose that the oldest subduction derived diamonds stem from BIF derived melts.

  9. Fullerenes, Organics and the Diffuse Interstellar Bands (United States)

    Foing, Bernard H.


    The status of DIB research has strongly advanced since 20 years [1], as well as the quest for fullerenes, PAHs and large organics in space. In 1994 we reported the discovery of two near IR diffuse bands coincident with C60+, confirmed in subsequent years [2-6] and now by latest laboratory experiments. A number of DIB observational studies have been published, dealing with: DIB surveys [1,7-10]; measurements of DIB families, correlations and environment dependences [11-14]; extragalactic DIBs [15, 16]. Resolved substructures were detected [17,18] and compared to predicted rotational contours by large molecules [19]. Polarisation studies provided upper limits constraints [20, 21]. DIBs carriers have been linked with organic molecules observed in the interstellar medium [22-25] such as IR bands (assigned to PAHs), Extended Red Emission or recently detected Anomalous Microwave Emission (AME, assigned to spinning dust) and with spectroscopic IR emission bands measured with ISO or Spitzer. Fullerenes and PAHs have been proposed to explain some DIBs and specific molecules were searched in DIB spectra [eg 2-6, 26-31]. These could be present in various dehydrogenation and ionisation conditions [32,33]. Experiments in the laboratory and in space [eg 34-36] allow to measure the survival and by-products of these molecules. We review DIB observational results and their interpretation, and discuss the presence of large organics, fullerenes, PAHs, graphenes in space. References [1] Herbig, G. 1995 ARA&A33, 19; [2] Foing, B. & Ehrenfreund, P. 1994 Natur 369, 296; [3] Foing, B. & Ehrenfreund, P. 1997 A&A317, L59; [4] Foing, B. & Ehrenfreund, P. 1995 ASSL202, 65; [5] Ehrenfreund, P., Foing, B. H. 1997 AdSpR19, 1033; [6] Galazutdinov, G. A. et al. 2000 MNRAS317, 750; [7] Jenniskens, P., Desert, F.-X. 1994 A&AS106, 39; [8] Ehrenfreund, P. et al. 1997 A&A318, L28; [9] Tuairisg, S. Ó. et al. 2000 A&AS142, 225; [10] Cox, N. et al. 2005 A&A438, 187; [11] Cami, J. et al. 1997A&A.326, 822

  10. Model Development for MODIS Thermal Band Electronic Crosstalk (United States)

    Chang, Tiejun; Wu, Aisheng; Geng, Xu; Li, Yonghonh; Brinkman, Jake; Keller, Graziela; Xiong, Xiaoxiong


    MODerate-resolution Imaging Spectroradiometer (MODIS) has 36 bands. Among them, 16 thermal emissive bands covering a wavelength range from 3.8 to 14.4 m. After 16 years on-orbit operation, the electronic crosstalk of a few Terra MODIS thermal emissive bands developed substantial issues that cause biases in the EV brightness temperature measurements and surface feature contamination. The crosstalk effects on band 27 with center wavelength at 6.7 m and band 29 at 8.5 m increased significantly in recent years, affecting downstream products such as water vapor and cloud mask. The crosstalk effect is evident in the near-monthly scheduled lunar measurements, from which the crosstalk coefficients can be derived. The development of an alternative approach is very helpful for independent verification.In this work, a physical model was developed to assess the crosstalk impact on calibration as well as in Earth view brightness temperature retrieval. This model was applied to Terra MODIS band 29 empirically to correct the Earth brightness temperature measurements. In the model development, the detectors nonlinear response is considered. The impact of the electronic crosstalk is assessed in two steps. The first step consists of determining the impact on calibration using the on-board blackbody (BB). Due to the detectors nonlinear response and large background signal, both linear and nonlinear coefficients are affected by the crosstalk from sending bands. The second step is to calculate the effects on the Earth view brightness temperature retrieval. The effects include those from affected calibration coefficients and the contamination of Earth view measurements. This model links the measurement bias with crosstalk coefficients, detector non-linearity, and the ratio of Earth measurements between the sending and receiving bands. The correction of the electronic cross talk can be implemented empirically from the processed bias at different brightness temperature. The implementation

  11. Construct and Concurrent Validation of a New Resistance Intensity Scale for Exercise with Thera-Band® Elastic Bands

    Directory of Open Access Journals (Sweden)

    Juan C. Colado, Xavier Garcia-Masso, N. Travis Triplett, Joaquin Calatayud, Jorge Flandez, David Behm, Michael E. Rogers


    Full Text Available The construct and concurrent validity of the Thera-Band Perceived Exertion Scale for Resistance Exercise with elastic bands (EB was examined. Twenty subjects performed two separate sets of 15 repetitions of both frontal and lateral raise exercise over two sessions. The criterion variables were myoelectric activity and heart rate. One set was performed with an elastic band grip width that permitted 15 maximum repetitions in the selected exercise, and another set was performed with a grip width 50% more than the 15RM grip. Following the final repetition of each set, active muscle (AM and overall body (O ratings of perceived exertion (RPE were collected from the Thera-Band® resistance exercise scale and the OMNI-Resistance Exercise Scale of perceived exertion with Thera-Band® resistance bands (OMNI-RES EB. Construct validity was established by correlating the RPE from the OMNI-RES EB with the Thera-Band RPE scale using regression analysis. The results showed significant differences (p ≤ 0.05 in myoelectric activity, heart rate, and RPE scores between the low- and high-intensity sets. The intraclass correlation coefficient for active muscles and overall RPE scale scores was 0.67 and 0.58, respectively. There was a positive linear relationship between the RPE from the OMNI-RES EB and the Thera-Band scale. Validity coefficients for the RPE AM were r2 = 0.87 and ranged from r2 = 0.76 to 0.85 for the RPE O. Therefore, the Thera-Band Perceived Exertion Scale for Resistance Exercise can be used for monitoring elastic band exercise intensity. This would allow the training dosage to be better controlled within and between sessions. Moreover, the construct and concurrent validity indicates that the OMNI-RES EB measures similar properties of exertion as the Thera-Band RPE scale during elastic resistance exercise.

  12. Multi-band, highly absorbing, microwave metamaterial structures (United States)

    Kollatou, T. M.; Dimitriadis, A. I.; Assimonis, S. D.; Kantartzis, N. V.; Antonopoulos, C. S.


    A further example of multi-band absorption using ultra-thin, polarization-insensitive, wide-angled metamaterial absorbers that operate in multi-frequency bands within the microwave regime is presented in this work. The basic structure geometry is utilised to create multi-band highly absorbing structures by incorporating the scalability property of the metamaterials. Simulation results verify the structure's ability for high absorption. The multi-band absorbers are promising candidates as absorbing elements in scientific and technical applications because of its multi-band absorption, polarization insensitivity, and wide-angle response. Finally, the current distributions for those structures are presented to gain a better insight into the physics behind the multiple absorption mechanism.

  13. Evaluation of Sentinel-2 Bands over the Spectrum (United States)

    Hosseini Aria, S. E.; Gorte, B.; Menenti, M.


    The spectral sampling (i.e. width and position of spectral bands) of multi-spectral sensors closely depends on mission objectives. It is planned that Sentinel-2 carries an optical payload with visible, near infrared and shortwave infrared sensors and provides enhanced continuity of SPOT- and Landsat-type data. This paper evaluates the spectral sampling of Sentinel-2 by a newly developed method based on Shannon’s information theory. The method tries to select the most informative spectral regions of the spectrum with defined accuracy. It has been applied on hyperspectral images collected over three different types of land cover including vegetation, water and bare soil. The method has given different bands combinations for each land cover showing informative spectral regions, which were then compared with Sentinel-2 bands. The results document the information content of Sentinel-2 through entropy assessment for each band and evaluation of its width and location by comparison with informative bands.

  14. Chiral topological excitons in a Chern band insulator (United States)

    Chen, Ke; Shindou, Ryuichi


    A family of semiconductors called Chern band insulators are shown to host exciton bands with nonzero topological Chern integers and chiral exciton edge modes. Using a prototypical two-band Chern insulator model, we calculate a cross-correlation function to obtain the exciton bands and their Chern integers. The lowest exciton band acquires Chern integers such as ±1 and ±2 in the electronic Chern insulator phase. The nontrivial topology can be experimentally observed both by a nonlocal optoelectronic response of exciton edge modes and by a phase shift in the cross-correlation response due to the bulk mode. Our result suggests that magnetically doped HgTe, InAs/GaSb quantum wells, and (Bi,Sb)2Te3 thin films are promising candidates for a platform of topological excitonics.

  15. Transient band keratopathy associated with ocular inflammation and systemic hypercalcemia

    Directory of Open Access Journals (Sweden)

    Anat Galor


    Full Text Available Anat Galor, Henry A Leder, Jennifer E Thorne, James P DunnThe Wilmer Eye Institute, Department of Ophthalmology, the Johns Hopkins University School of MedicinePurpose: To report a case of visually significant band keratopathy associated with ocular inflammation and systemic hypercalcemia which markedly decreased in severity after treatment of these underlying factors.Methods: Retrospective case report.Results: A 53-year-old Asian female with granulomatous panuveitis in the left eye presented with diffuse band keratopathy through the central cornea. The serum calcium was elevated. The patient was treated with topical prednisolone acetate 1% and oral prednisone with marked improvement in inflammation. The band keratopathy lessened in severity with clearing of the central cornea and improvement in visual acuity.Conclusions: Early medical treatment of underlying factors may allow reversal of band keratopathy.Keywords: ocular inflammation, transient band keratopathy

  16. Absorption enhancement of a dual-band metamaterial absorber (United States)

    Zhong, Min; Han, Gui Ming; Liu, Shui Jie; Xu, Bang Li; Wang, Jie; Huang, Hua Qing


    In this paper, we propose and fabricate a dual-band metamaterial absorber in 6-24 THz region. Electric field distribution reveal that the first absorption band is obtained from localized surface plasmon (LSP) modes which are excited both on inside and outside edges of each circular-patterned metal-dielectric stack, while the second absorption band is excited by LSP modes on outside edges of each stack. Measured results indicate that the absorption band width can be tuned by increasing the radius of circular-patterned layers or reducing the thickness of dielectric spacing layers. Moreover, the designed dual-band metamaterial absorber is independent on circular-patterned dielectric layer combinations.

  17. Tunable band structures in digital oxides with layered crystal habits (United States)

    Shin, Yongjin; Rondinelli, James M.


    We use density functional calculations to show that heterovalent cation-order sequences enable control over band-gap variations up to several eV and band-gap closure in the bulk band insulator LaSrAlO4. The band-gap control originates from the internal electric fields induced by the digital chemical order, which induces picoscale band bending; the electric-field magnitude is mainly governed by the inequivalent charged monoxide layers afforded by the layered crystal habit. Charge transfer and ionic relaxations across these layers play secondary roles. This understanding is used to construct and validate a descriptor that captures the layer-charge variation and to predict changes in the electronic gap in layered oxides exhibiting antisite defects and in other chemistries.

  18. A parallel implementation of symmetric band reduction using PLAPACK

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yuan-Jye J.; Bischof, C.H. [Argonne National Lab., IL (United States); Alpatov, P.A. [Univ. of Texas, Austin, TX (United States). Dept. of Physics] [and others


    Successive band reduction (SBR) is a two-phase approach for reducing a full symmetric matrix to tridiagonal (or narrow banded) form. In its simplest case, it consists of a full-to-band reduction followed by a band-to-tridiagonal reduction. Its richness in BLAS-3 operations makes it potentially more efficient on high-performance architectures than the traditional tridiagonalization method. However, a scalable, portable, general-purpose parallel implementation of SBR is still not available. In this article, we review some existing parallel tridiagonalization routines and describe the implementation of a full-to-band reduction routine using PLAPACK as a first step toward a parallel SBR toolbox. The PLAPACK-based routine turns out to be simple and efficient and, unlike the other existing packages, does not suffer restrictions on physical data layout or algorithmic block size.

  19. Band structures in Sierpinski triangle fractal porous phononic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Kai; Liu, Ying, E-mail:; Liang, Tianshu


    In this paper, the band structures in Sierpinski triangle fractal porous phononic crystals (FPPCs) are studied with the aim to clarify the effect of fractal hierarchy on the band structures. Firstly, one kind of FPPCs based on Sierpinski triangle routine is proposed. Then the influence of the porosity on the elastic wave dispersion in Sierpinski triangle FPPCs is investigated. The sensitivity of the band structures to the fractal hierarchy is discussed in detail. The results show that the increase of the hierarchy increases the sensitivity of ABG (Absolute band gap) central frequency to the porosity. But further increase of the fractal hierarchy weakens this sensitivity. On the same hierarchy, wider ABGs could be opened in Sierpinski equilateral triangle FPPC; whilst, a lower ABG could be opened at lower porosity in Sierpinski right-angled isosceles FPPCs. These results will provide a meaningful guidance in tuning band structures in porous phononic crystals by fractal design.

  20. Comparison of device models for organic solar cells: Band-to-band vs. tail states recombination

    Energy Technology Data Exchange (ETDEWEB)

    Soldera, Marcos; Taretto, Kurt [Departamento de Electrotecnia, Universidad Nacional del Comahue, Buenos Aires, Neuquen (Argentina); Kirchartz, Thomas [Department of Physics, Imperial College London, South Kensington (United Kingdom)


    The efficiency-limiting recombination mechanism in bulk-heterojunction (BHJ) solar cells is a current topic of investigation and debate in organic photovoltaics. In this work, we simulate state-of-the-art BHJ solar cells using two different models. The first model takes into account band-to-band recombination and field dependent carrier generation. The second model assumes a Shockley-Read-Hall (SRH) recombination mechanism via tail states and field independent carrier generation. Additionally, we include in both cases optical modelling and, thus, position-dependent exciton generation and non-ideal exciton collection. We explore both recombination mechanisms by fitting light and dark current-voltage (JV) characteristics of BHJ cells of five materials: P3HT, MDMO-PPV, MEH-PPV, PCDTBT and PF10TBT, all blended with fullerene derivatives. We show that although main device parameters such as short circuit current, open circuit voltage, fill factor and ideality factor are accurately reproduced by both Langevin and tail recombination, only tail recombination reproduces also the ideality factor of dark characteristics accurately. Nevertheless, the model with SRH recombination via tail states needs the inclusion of external circuitry to account for the heavy shunt present in all the blends, except P3HT:PCBM, when illuminated. Finally, we propose a means to find analytical expressions for the short circuit current by assuming a linear relation between the recombination rate and the concentration of free minority carriers. The model reproduces experimental data of P3HT cells at various thickness values using realistic parameters for this material. Dark JV measurement (circles) of a PCDTBT:PC{sub 70}BM solar cell (Park et al., Nature Photon. 3, 297 (2009) [1]), the fit with the model including recombination via tail states (solid line) and the fit with the model reported by (Koster et al., Phys. Rev. B 72, 085205 (2005) [2]) that includes bimolecular band-to-band recombination

  1. Building blocks of topological quantum chemistry: Elementary band representations (United States)

    Cano, Jennifer; Bradlyn, Barry; Wang, Zhijun; Elcoro, L.; Vergniory, M. G.; Felser, C.; Aroyo, M. I.; Bernevig, B. Andrei


    The link between chemical orbitals described by local degrees of freedom and band theory, which is defined in momentum space, was proposed by Zak several decades ago for spinless systems with and without time reversal in his theory of "elementary" band representations. In a recent paper [Bradlyn et al., Nature (London) 547, 298 (2017), 10.1038/nature23268] we introduced the generalization of this theory to the experimentally relevant situation of spin-orbit coupled systems with time-reversal symmetry and proved that all bands that do not transform as band representations are topological. Here we give the full details of this construction. We prove that elementary band representations are either connected as bands in the Brillouin zone and are described by localized Wannier orbitals respecting the symmetries of the lattice (including time reversal when applicable), or, if disconnected, describe topological insulators. We then show how to generate a band representation from a particular Wyckoff position and determine which Wyckoff positions generate elementary band representations for all space groups. This theory applies to spinful and spinless systems, in all dimensions, with and without time reversal. We introduce a homotopic notion of equivalence and show that it results in a finer classification of topological phases than approaches based only on the symmetry of wave functions at special points in the Brillouin zone. Utilizing a mapping of the band connectivity into a graph theory problem, we show in companion papers which Wyckoff positions can generate disconnected elementary band representations, furnishing a natural avenue for a systematic materials search.

  2. Endoscopic management of erosion after banded bariatric procedures. (United States)

    Spann, Matthew D; Aher, Chetan V; English, Wayne J; Williams, D Brandon


    Prosthetic materials wrapped around a portion of the stomach have been used to provide gastric restriction in bariatric surgery for many years. Intraluminal erosion of adjustable and nonadjustable gastric bands typically occurs many years after placement and results in various symptoms. Endoscopic management of gastric band erosion has been described and allows for optimal patient outcomes. We will describe our methods and experience with endoscopic management of intraluminal gastric band erosions after bariatric procedures. University hospital in the United States. A retrospective review of our bariatric surgery database identified patients undergoing removal of gastric bands. A chart review was then undertaken to confirm erosion of prosthetic material into the gastrointestinal tract. Baseline characteristics, operative reports, and follow-up data were analyzed. Sixteen patients were identified with an eroded gastric band: 11 after banded gastric bypass, 3 after laparoscopic adjustable gastric band (LAGB), and 2 after vertical banded gastroplasty. All patients were successfully treated with endoscopic removal of the prosthetic materials using either endoscopic scissors or ligation of the banding material with off-label use of a mechanical lithotripter device. Complications included a postoperative gastrointestinal bleed requiring repeat endoscopy, 1 patient with asymptomatic pneumoperitoneum requiring observation, and 1 with seroma at the site of LAGB port removal. Endoscopic management of intraluminal prosthetic erosion after gastric banded bariatric procedures can be safe and effective and should be considered when treating this complication. Erosion of the prosthetic materials inside the gastric lumen allows for potential endoscopic removal without free intraabdominal perforation. Endoscopic devices designed for dividing eroded LAGBs may help standardize and increase utilization of this approach. Copyright © 2017 American Society for Bariatric Surgery

  3. Microstructural banding in thermally and mechanically processed titanium 6242 (United States)

    Kansal, U.; Kassner, M. E.; Hiatt, D. R.; Bristow, B. M.


    Ti-6Al-2Sn-4Zr-2Mo-0.1Si coupons were shaped by repeated cycles of heating (to 954 °) and hammer or press forging followed by a solution anneal that varied from 968 to 998 °. The coupons were originally extracted from billets forged below the beta transus (1009 °) and slow cooled to ambient temperatures. Macroscopic and microstructural banding is observed in some forged and solution annealed coupons. The microstructure consists of elongated “platelets” of primary alpha. More significant banding is observed subsequent to annealing at lower temperatures (968 °), whereas subsequent to higher annealing temperatures (998 °) much less microstructural banding is present. About the same level of banding is observed in hammer forged coupons and press forged coupons. The observation of these bands is significant, because these may lead to inhomogeneous mechanical properties. Specifically, some types of banding are reported to affect the high-temperature creep properties of this alloy. Classically, banding in Ti6242-0.1Si has been regarded as a result of adiabatic shear, chill zone formation, or compositional in homogeneity. High- and low-magnification metallography, electron microprobe analysis, and micro-hardness tests were performed on forged and annealed specimens in this investigation. The bands of this study appear to originate from the microstructure that consists of the forged billet of elongated primary alpha. The deformation of the extracted coupon is neither fully homogeneous nor sufficiently substantial, and the coupon is only partly statically restored after a solution anneal. Areas not fully restored appear as “bands” with elongated primary alpha that are remnant of the starting billet microstructure. Therefore, a source of banding in Ti- 6242- O.1Si alloy additional to the classic sources is evident. This type of banding is likely removed by relatively high solution treatment temperatures and perhaps greater plastic deformation during forging.

  4. 76 FR 11681 - Improving Public Safety Communications in the 800 MHz Band; New 800 MHz Band Plan for Puerto Rico... (United States)


    ... for Puerto Rico and the U.S. Virgin Islands AGENCY: Federal Communications Commission. ACTION: Final... plan in the USVI as it had adopted in Puerto Rico, 75 FR 35363, June 22, 2010. The Bureau received two... band segment. Currently, there are no NPSPAC licensees in the USVI. As with the Puerto Rico band plan...

  5. Head and hand detuning effect study of narrow-band against wide-band mobile phone antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund


    Wide-band (WB) and narrow-band (NB) antennas in terms of performance are compared, when interacting with the user’s right head and hand (RHH). The investigations are done through experimental measurements, using standardised head phantom and hand. It is shown that WB antennas detune more than NB ...

  6. Advances in X-Band and S-Band Linear Accelerators for Security, NDT, and Other Applications

    CERN Document Server

    Mishin, Andrey V


    At AS&E High Energy Systems Division, we designed several new advanced high energy electron beam and X-ray sources. Our primary focus has always been in building the world's most portable commercial X-band accelerators. Today, our X-band systems frequently exceed performance of the similar S-band machines, while they are more portable compared to the latter. The new designs of the X-band accelerators in the most practical energy range from 1 MeV to 6 MeV have been tested delivering outstanding results. Seventy 6 MeV X-band linacs systems have been produced. The most compact linac for security is used by AS&E in a self-shielded, Shaped Energy™ cargo screening system. We pioneered using the X-band linear accelerators for CT, producing high quality images of oil pipes and wood logs. An X-band linear accelerator head on a robotic arm has been used for electron beam radiation curing of an odd-shaped graphite composite part. We developed the broad-range 4 MeV to over 10 MeV energy-regulated X-band ...

  7. The lupus band: do the autoantibodies target collagen VII? (United States)

    Alahlafi, A M; Wordsworth, P; Wojnarowska, F


    Circulating autoantibodies directed against basement membrane zone (BMZ) components from patients with bullous pemphigoid and epidermolysis bullosa acquisita have been used to identify their target antigen in the skin and to confirm pathogenicity. Although the pattern of immunofluorescence in those diseases is similar to the lupus band, little is known about the origin and pathogenesis of the lupus band. Identifying the binding sites of the lupus band could provide a clue to the nature of the autoantigen that stimulates autoantibody formation in the skin of patients with systemic lupus erythematosus (SLE) and might provide valuable insight into the factors that influence the localization and pathogenicity of the lupus band. To investigate the relation between the lupus band and the main BMZ components and to identify the target epitopes of autoantibodies deposited in the skin of patients with SLE. Colocalization of the main components of the skin BMZ in nonlesional SLE skin with the lupus band was investigated using conventional immunofluorescence and confocal laser scanning microscopy. The effect of collagenase and pepsin on the expression of the lupus band was correlated with the differential sensitivity of these proteases on the collagenous and noncollagenous (NC) domains of collagen VII. Reactivity of sera from patients with SLE to a complete recombinant human NC1 domain of type VII collagen was then investigated by enzyme-linked immunosorbent assay (ELISA). Near complete colocalization of the lupus band with collagen VII was found in this study, and chemical degradation of the skin attenuated the expression of the lupus band. Collectively, the NC1 domain of collagen VII was suggested as the target antigen of the lupus band, but none of the sera from patients with SLE reacted with recombinant NC1 domain-coated ELISA plates. Alternative explanations for the results of the colocalization of the lupus band with collagen VII are discussed. The lupus band

  8. Unfolding the band structure of electronic and photonic materials (United States)

    Maspero, Ross

    In this thesis, we develop a generalised unfolding formalism to investigate the electronic and photonic properties of aperiodically-structured materials. We initially focus on GaAsBi alloys for electronic systems and Penrose-structured materials for photonic systems, aperiodic materials that cannot be easily studied using conventional band structure methods. We then extend our study to the supercell approach which facilitates an accurate modelling of the aperiodic structures at the price of obscuring essential physical information, due to a band folding effect. Then introducing a generalised unfolding algorithm, we return the supercell band structure to a traditional form that can again be used to analyse the electronic and photonic properties of the system. GaAsBi, which is a material with the potential to suppress the dominant loss mechanisms in telecommunications devices, was studied using the unfolded supercell band structure approach. We investigated the effect of bismuth on the properties of a host GaAs structure, including band movement, band broadening and effective mass. We validated our approach through a detailed comparison of both band movement and effective masses to the currently available experimental data. Then, we introduced a formalism for calculating the CHSH Auger recombination rates from our unfolded band structure, which will assist in determining the efficiency of the material. Quasicrystalline photonic materials built on the skeleton of Penrose lattices have proven to display photonic properties comparable to the ones found in photonic crystals, but with the added promise of increased isotropy. The photonic band structure of these materials is a prime target for the unfolding formalism because it allows a full exploration of the influence of the increased geometrical symmetry on their photonic characteristics. Furthermore, the network structure investigated demonstrated the existence of a sub-fundamental photonic band gap, a characteristic

  9. Physical properties and analytical models of band-to-band tunneling in low-bandgap semiconductors (United States)

    Shih, Chun-Hsing; Dang Chien, Nguyen


    Low-bandgap semiconductors, such as InAs and InSb, are widely considered to be ideal for use in tunnel field-effect transistors to ensure sufficient on-current boosting at low voltages. This work elucidates the physical and mathematical considerations of applying conventional band-to-band tunneling models in low-bandgap semiconductors, and presents a new analytical alternative for practical use. The high-bandgap tunneling generates most at maximum field region with shortest tunnel path, whereas the low-bandgap generations occur dispersedly because of narrow tunnel barrier. The local electrical field associated with tunneling-electron numbers dominates in low-bandgap materials. This work proposes decoupled electric-field terms in the pre-exponential factor and exponential function of generation-rate expressions. Without fitting, the analytical results and approximated forms exhibit great agreements with the sophisticated forms both in high- and low-bandgap semiconductors. Neither nonlocal nor local field is appropriate to be used in numerical simulations for predicting the tunneling generations in a variety of low- and high-bandgap semiconductors.

  10. High-performance Ka-band and V-band HEMT low-noise amplifiers (United States)

    Duh, K. H. George; Chao, Pane-Chane; Smith, Phillip M.; Lester, Luke F.; Lee, Benjamin R.


    Quarter-micron-gate-length high-electron-mobility transistors (HEMTs) have exhibited state-of-the-art low-noise performance at millimeter-wave frequencies, with minimum noise figures of 1.2 dB at 32 GHz and 1.8 dB at 60 GHz. At Ka-band, two-stage and three-stage HEMT low noise amplifiers have demonstrated noise figures of 1.7 and 1.9 dB, respectively, with associated gains of 17.0 and 24.0 dB at 32 GHz. At V-band, two stage and three-stage HEMT amplifiers yielded noise figures of 3.2 and 3.6 dB, respectively, with associated gains of 12.7 and 20.0 dB at 60 GHz. The 1-dB-gain compression point of all the amplifiers is greater than +6 dBm. The results clearly show the potential of short-gate-length HEMTs for high-performance millimeter-wave receiver applications.

  11. Effect of annealing on chemical, structural and electrical properties of Au/Gd2O3/n-GaN heterostructure with a high-k rare-earth oxide interlayer (United States)

    Prasad, C. Venkata; Reddy, M. Siva Pratap; Rajagopal Reddy, V.; Park, Chinho


    The chemical, structural and electrical characteristics of a fabricated Au/Gd2O3/n-GaN heterostructure with gadolinium oxide (Gd2O3) as an insulating layer are explored by XPS, XRD and I-V techniques at room temperature and 400 °C annealing. XPS and XRD results reveal that the Gd2O3 films are formed at the interface. The electrical results of heterostructure are correlated with the conventional Au/n-GaN Schottky structure results. The as-deposited and 400 °C annealed heterostructures exhibited excellent rectifying behavior and very low reverse leakage current compared to the Schottky structure. Higher barrier height (BH) and on/off ratio are achieved for the heterostructure compared to the Schottky structure, which has led the barrier height modified by Gd2O3 insulating layer. Also, the results indicate that the BH slightly increases for the 400 °C annealed heterostructures. Further, the BH, ideality factor and series resistance are evaluated by Cheung's, Norde functions and ΨS-V plot and the values are found to be similar with one another that indicates their consistency and validity. In addition, the mechanism of the BH modulation could be explained by feasible energy level band diagrams. These findings indicate that the Gd2O3 films could be a favored dielectric material for the development of metal/insulating/semiconductor devices.

  12. X-Band CubeSat Communication System Demonstration (United States)

    Altunc, Serhat; Kegege, Obadiah; Bundick, Steve; Shaw, Harry; Schaire, Scott; Bussey, George; Crum, Gary; Burke, Jacob C.; Palo, Scott; O'Conor, Darren


    Today's CubeSats mostly operate their communications at UHF- and S-band frequencies. UHF band is presently crowded, thus downlink communications are at lower data rates due to bandwidth limitations and are unreliable due to interference. This research presents an end-to-end robust, innovative, compact, efficient and low cost S-band uplink and X-band downlink CubeSat communication system demonstration between a balloon and a Near Earth Network (NEN) ground system. Since communication systems serve as umbilical cords for space missions, demonstration of this X-band communication system is critical for successfully supporting current and future CubeSat communication needs. This research has three main objectives. The first objective is to design, simulate, and test a CubeSat S- and X-band communication system. Satellite Tool Kit (STK) dynamic link budget calculations and HFSS Simulations and modeling results have been used to trade the merit of various designs for small satellite applications. S- and X-band antennas have been tested in the compact antenna test range at Goddard Space Flight Center (GSFC) to gather radiation pattern data. The second objective is simulate and test a CubeSat compatible X-band communication system at 12.5Mbps including S-band antennas, X-band antennas, Laboratory for Atmospheric and Space Physics (LASP) /GSFC transmitter and an S-band receiver from TRL-5 to TRL-8 by the end of this effort. Different X-band communication system components (antennas, diplexers, etc.) from GSFC, other NASA centers, universities, and private companies have been investigated and traded, and a complete component list for the communication system baseline has been developed by performing analytical and numerical analysis. This objective also includes running simulations and performing trades between different X-band antenna systems to optimize communication system performance. The final objective is to perform an end-to-end X-band CubeSat communication system

  13. Phase Field Modeling of Microstructure Banding in Steels (United States)

    Maalekian, Mehran; Azizi-Alizamini, Hamid; Militzer, Matthias


    A phase field model (PFM) is applied to simulate the effects of microsegregation, cooling rate, and austenite grain size on banding in a C-Mn steel. The PFM simulations are compared with experimental observations of continuous cooling transformation tests in the investigated steel. Using electron probe microanalysis, the microsegregation characteristics of Mn were determined and introduced into the model. Ferrite nucleation is assumed to occur at austenite grain boundaries, and ferrite growth is simulated as mixed-mode reaction for para-equilibrium conditions. The driving pressure for the austenite to ferrite transformation depends on Mn concentration and thus varies between the alternating microsegregation layers. In agreement with experimental observations, the simulation results demonstrate that by increasing the cooling rate and/or austenite grain size, banding tends to disappear as the transformation shifts to lower temperatures such that ferrite also forms readily in the layers with higher Mn levels. Further, a parametric study is conducted by changing thickness and Mn content of the bands. In accordance with experimental observations, it is shown that for sufficiently large band thickness, band splitting takes place where ferrite grains form close to the center of the Mn-rich band. Changing the degree of Mn segregation indicates that a segregation level of 0.2 wt pct is necessary in the present case to achieve banded microstructures.

  14. Rotational bands in sup 1 sup 6 sup 9 Re

    CERN Document Server

    Zhou Xiao Hong; Zheng Yong; Oshima, M; Toh, Y; Koizumi, M; Osa, A; Hayakawa, T; Hatsukawa, Y; Shizuma, T; Sugawara, M


    The excited states of sup 1 sup 6 sup 9 Re have been investigated by means of in-beam gamma-ray spectroscopy techniques with the sup 1 sup 4 sup 4 Sm( sup 2 sup 8 Si, 1p2n gamma) sup 1 sup 6 sup 9 Re reaction. X-gamma and gamma-gamma-t coincidences, DCO ratios and intra-band B(M1)/B(E2) ratios were measured. A strongly coupled band based on the 9/2 sup - [514] Nilsson state and a decoupled band built on the h sub 9 sub / sub 2 intruder proton orbital (nominally 1/2 sup - [541]) have been established. Their configurations are proposed on the basis of B(M1)/B(E2) ratios and by comparing the band properties with known bands in neighboring odd-proton nuclei. The neutron AB crossings are observed at Planck constant omega 0.23 and 0.27 MeV for the pi 9/2 sup - [514] and pi 1/2 sup - [541] bands, respectively. Band properties of the neutron AB crossing frequencies, alignment gains and signature splittings are discussed, and compared with those in the heavier odd-A Re isotopes

  15. Coral disease diagnostics: what's between a plague and a band? (United States)

    Ainsworth, T D; Kramasky-Winter, E; Loya, Y; Hoegh-Guldberg, O; Fine, M


    Recently, reports of coral disease have increased significantly across the world's tropical oceans. Despite increasing efforts to understand the changing incidence of coral disease, very few primary pathogens have been identified, and most studies remain dependent on the external appearance of corals for diagnosis. Given this situation, our current understanding of coral disease and the progression and underlying causes thereof is very limited. In the present study, we use structural and microbial studies to differentiate different forms of black band disease: atypical black band disease and typical black band disease. Atypical black band diseased corals were infected with the black band disease microbial consortium yet did not show any of the typical external signs of black band disease based on macroscopic observations. In previous studies, these examples, here referred to as atypical black band disease, would have not been correctly diagnosed. We also differentiate white syndrome from white diseases on the basis of tissue structure and the presence/absence of microbial associates. White diseases are those with dense bacterial communities associated with lesions of symbiont loss and/or extensive necrosis of tissues, while white syndromes are characteristically bacterium free, with evidence for extensive programmed cell death/apoptosis associated with the lesion and the adjacent tissues. The pathology of coral disease as a whole requires further investigation. This study emphasizes the importance of going beyond the external macroscopic signs of coral disease for accurate disease diagnosis.

  16. Diagnostic Value of Narrow Band Imaging in Diagnosing Nasopharyngeal Carcinoma

    Directory of Open Access Journals (Sweden)

    Debbi Yuniserani


    Full Text Available Background: Carcinoma is the most common tumor in nasopharynx. Endoscopy is used to determine the presence of lesions suspected of malignancy. Narrow Band Imaging is an endoscopic technique that uses narrow–band spectrum as a filter to determine any mucosal vascular changes in carcinoma. Narrow Band Imaging can early detect superficial mucosal lesions that are difficult to detect with conventional endoscopy, so that diagnosing is more accurate and occurrence of unnecessary biopsies can be reduced. This study aimed to determine diagnostic value of Narrow Band Imaging in diagnosing nasopharyngeal carcinoma. Methods: This diagnostic test study was conducted at Department of Otorhinolaryngology-Head and Neck Surgery Dr. Hasan Sadikin General Hospital, Bandung from September to October 2014. Twenty four patients with clinical signs and symptoms of nasopharyngeal carcinoma that fulfilled the study criteria were assigned using consecutive sampling to examine with Narrow Band Imaging and histopathology examination. The data were then analyzed with 2x2 table to determine sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Results: In this study, the results of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in diagnosing nasopharyngeal carcinoma using Narrow Band Imaging were 93.75%, 62.5%, 83.3%, 83.3%, and 83.3%, respectively. Conclusions: Sensitivity of Narrow Band Imaging is 93.75%.

  17. New results on superdeformed bands in Hg and Tl nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Janssens, R.V.F.; Liang, Y.; Ahmad, I.; Henry, R.G.; Khoo, T.L.; Lauritsen, T.; Soramel, F. [Argonne National Lab., IL (United States); Bearden, I.G. [Purdue Univ., Lafayette, IN (United States). Dept. of Physics; Drigert, M.W. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Garg, U.; Reviol, W. [Notre Dame Univ., IN (United States). Dept. of Physics; Lewis, J.M.; Riedinger, L.L.; Yu, C.H. [Tennessee Univ., Knoxville, TN (United States). Dept. of Physics; Pilotte, S. [Ottawa Univ., ON (Canada). Dept. of Physics


    New results have been obtained on superdeformed states in {sup 190}Hg, {sup 191}Tl, and {sup 192}Tl. For {sup 190}Hg, the previously identified superdeformed band has been extended up to a rotational frequency of {Dirac_h}{omega} {ge} 0.40 MeV by combining data from several different experiments. The extracted dynamical moment of inertia J({sup 2}) vs {Dirac_h}{omega} exhibits a distinct change in slope at {Dirac_h}{omega} = 0.32 MeV. For {sup 191}Tl and {sup 192}Tl, two and six superdeformed bands have been identified in these nuclei, respectively. Six of these eight bands exhibit a smooth rise in J({sup 2}) with {Dirac_h}{omega} characteristic of the other superdeformed bands identified in this mass region while the remaining two bands which are in {sup 192}Tl show a constant J({sup 2}) with {Dirac_h}{omega}. This new result can be understood in terms of Pauli blocking of quasiparticle alignments in high-N intruder orbitals. The new result for {sup 190}Hg is interpreted as evidence of a band interaction at the highest frequencies due to the rotational alignment of a pair of quasiparticles into these same intruder orbitals. These two new features taken together represent the first conclusive evidence that the alignment of intruders is responsible for the smooth rise in J({sup 2}) seen in the other superdeformed bands of this mass region.

  18. Band gap effects of hexagonal boron nitride using oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sevak Singh, Ram; Leong Chow, Wai [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Yingjie Tay, Roland [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Temasek Laboratories-NTU, 50 Nanyang Avenue, Singapore 639798 (Singapore); Hon Tsang, Siu [Temasek Laboratories-NTU, 50 Nanyang Avenue, Singapore 639798 (Singapore); Mallick, Govind [Temasek Laboratories-NTU, 50 Nanyang Avenue, Singapore 639798 (Singapore); Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States); Tong Teo, Edwin Hang, E-mail: [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)


    Tuning of band gap of hexagonal boron nitride (h-BN) has been a challenging problem due to its inherent chemical stability and inertness. In this work, we report the changes in band gaps in a few layers of chemical vapor deposition processed as-grown h-BN using a simple oxygen plasma treatment. Optical absorption spectra show a trend of band gap narrowing monotonically from 6 eV of pristine h-BN to 4.31 eV when exposed to oxygen plasma for 12 s. The narrowing of band gap causes the reduction in electrical resistance by ∼100 fold. The x-ray photoelectron spectroscopy results of plasma treated hexagonal boron nitride surface show the predominant doping of oxygen for the nitrogen vacancy. Energy sub-band formations inside the band gap of h-BN, due to the incorporation of oxygen dopants, cause a red shift in absorption edge corresponding to the band gap narrowing.

  19. Effect of Outflow Tract Banding on Embryonic Cardiac Hemodynamics

    Directory of Open Access Journals (Sweden)

    Venkat Keshav Chivukula


    Full Text Available We analyzed heart wall motion and blood flow dynamics in chicken embryos using in vivo optical coherence tomography (OCT imaging and computational fluid dynamics (CFD embryo-specific modeling. We focused on the heart outflow tract (OFT region of day 3 embryos, and compared normal (control conditions to conditions after performing an OFT banding intervention, which alters hemodynamics in the embryonic heart and vasculature. We found that hemodynamics and cardiac wall motion in the OFT are affected by banding in ways that might not be intuitive a priori. In addition to the expected increase in ventricular blood pressure, and increase blood flow velocity and, thus, wall shear stress (WSS at the band site, the characteristic peristaltic-like motion of the OFT was altered, further affecting flow and WSS. Myocardial contractility, however, was affected only close to the band site due to the physical restriction on wall motion imposed by the band. WSS were heterogeneously distributed in both normal and banded OFTs. Our results show how banding affects cardiac mechanics and can lead, in the future, to a better understanding of mechanisms by which altered blood flow conditions affect cardiac development leading to congenital heart disease.

  20. Natural and Laboratory-Induced Compaction Bands in Aztec Sandstone (United States)

    Haimson, B. C.; Lee, H.


    The Aztec sandstone used in this research is from the Valley of Fire State Park area, Nevada. This Jurassic aeolian sandstone is extremely weak (uniaxial compressive strength of 1-2 MPa); porosity averages 26%; grains are subrounded and have a bimodal size distribution (0.1 mm and 0.5 mm); its mineral composition (K. Sternlof, personal comm.) is 93% quartz, 5% k-spar, and 2% kaolinite, Fe carbonate and others; grain bonding is primarily through suturing. Sternlof et al. (EOS, November, 2001) observed substantial exposure of mainly compactive deformation bands in the Aztec sandstone. We studied an SEM image of a compaction band found in a hand sample of the Aztec sandstone. We also conducted a drilling test in a 130x130x180 mm prismatic specimen subjected to a preset far-field true triaxial stress condition (\\sigmah = 15 MPa, \\sigmav = 25 MPa, \\sigmaH = 40 MPa). Drilling of a 20 mm dia. vertical hole created a long fracture-like thin tabular breakout along the \\sigmah springline and perpendicular to \\sigmaH direction. SEM analysis of the zones ahead of the breakout tips revealed narrow bands of presumed debonded intact grains interspersed with grain fragments. We infer that the fragments were formed from multiple splitting or crushing of compacted grains in the band of high compressive stress concentration developed along the \\sigmah springline. SEM images away from the breakout tip surroundings showed no such fragments. SEM study of the natural compaction band showed a similar arrangement of mainly intact grains surrounded by grain fragments. Using the Optimas optical software package, we found the percentage of pore area within the band ahead of the breakout tips to average 17%; outside of this zone it was 23%. In the natural compaction band pore area occupied 8.5% of the band; in the host rock adjacent to the compaction band it averaged 19%. These readings strongly suggest porosity reduction due to compaction in both cases. The close resemblance between the

  1. Optical Tunable-Based Transmitter for Multiple Radio Frequency Bands (United States)

    Nguyen, Hung (Inventor); Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor); Freeman, Jon C. (Inventor)


    An optical tunable transmitter is used to transmit multiple radio frequency bands on a single beam. More specifically, a tunable laser is configured to generate a plurality of optical wavelengths, and an optical tunable transmitter is configured to modulate each of the plurality of optical wavelengths with a corresponding radio frequency band. The optical tunable transmitter is also configured to encode each of the plurality of modulated optical wavelengths onto a single laser beam for transmission of a plurality of radio frequency bands using the single laser beam.

  2. Earth Studies Using L-band Synthetic Aperture Radar (United States)

    Rosen, Paul A.


    L-band SAR has played an important role in studies of the Earth by revealing the nature of the larger-scale (decimeter) surface features. JERS-1, by supplying multi-seasonal coverage of the much of the earth, has demonstrated the importance of L-band SARs. Future L-band SARs such as ALOS and LightSAR will pave the way for science missions that use SAR instruments. As technology develops to enable lower cost SAR instruments, missions will evolve to each have a unique science focus. International coordination of multi-parameter constellations and campaigns will maximize science return.

  3. The Band Gap Estimation of Zinc Manganese Phosphate Glasses (United States)

    Siddiqi, S. A.; Ghauri, M. A.; Baig, M. J. S.

    Zinc manganese phosphate glasses (ZnO-MnO-P2O5) of different compositions are synthesized. The optical band gaps are measured in the UV-VIS region. Photoconduction measurements are also made in the spectral energy range 1.5-6.2 eV. At various applied electric fields, the values of the energy band gaps have been deduced from the spectral dependence curves. Furthermore, the band gaps at zero applied voltage were also obtained for different compositions. The charge transport mechanism in these glasses is studied under the Mott's model.

  4. [Elastic adhesive colored bands: description of a new approach]. (United States)

    Kerkour, Khelaf; Meier, Jean-Louis


    The new approach of the taping, come from Japan, with coloured sticking adhesive bands, allows another approach in the control and the improvement of the pain and the function among sporting patients or not. The sticking bands have the properties of the skin (weight, thickness, elasticity) and will influence the articular, muscular but especially circulatory function (venous, lymphatic) and the nociceptors (neuroproprioceptive action).Various techniques (muscular, ligament, aponevrotic, lymphatic, neural of correction) are used. The choice of the colours, of the direction of the bands, their tension is a function of the therapeutic objectives. As for any technique, a formation is essential before any use.

  5. Teletraffic performance Analysis of Multi-band Overlaid WCDMA Systems

    DEFF Research Database (Denmark)

    Wang, Hua; Iversen, Villy Bæk


    Wide-band Code Division Multiple Access (WCDMA) systems are considered to be among the best alternatives for Universal Mobile Telecommunication System (UMTS). In future deployment of WCDMA systems, spectrum overlay among sub-bands with different bandwidth is necessary to support various kinds...... of services. In this paper, we present a novel approach for evaluating the teletraffic performance of multi-band overlaid WCDMA systems in terms of time, call, and traffic blocking probabilities of each service class. We convert the radio model into a circuit switched network by introducing the concept...

  6. Sub-band-gap laser micromachining of lithium niobate

    DEFF Research Database (Denmark)

    Christensen, F. K.; Müllenborn, Matthias


    method is reported which enables us to do laser processing of lithium niobate using sub-band-gap photons. Using high scan speeds, moderate power densities, and sub-band-gap photon energies results in volume removal rates in excess of 106µm3/s. This enables fast micromachining of small piezoelectric......Laser processing of insulators and semiconductors is usually realized using photon energies exceeding the band-gap energy. This makes laser processing of insulators difficult since high photon energies typically require either a pulsed laser or a frequency-doubled continuous-wave laser. A new...

  7. Large sonic band gaps in 12-fold quasicrystals (United States)

    Lai, Yun; Zhang, Xiangdong; Zhang, Zhao-Qing


    The sonic band-gap structures of 12-fold symmetry quasicrystals consisting of rigid cylinders in air are investigated by using the multiple scattering method. Large full gaps are found in this system owing to its high symmetry. At filling fractions between 0.2 and 0.4, this 12-fold square-triangle tiling is much better for the realization of sonic band gaps than the square or triangular lattice. This makes the 12-fold quasicrystal a promising structure for acoustic-wave band-gap materials.

  8. Chaos in the band structure of a soft Sinai lattice (United States)

    Porter, Max D.; Barr, Aaron; Barr, Ariel; Reichl, L. E.


    We study the effect of broken spatial and dynamical symmetries on the band structure of two lattices with unit cells that are soft versions of the classic Sinai billiard. We find significant signatures of chaos in the band structure of these lattices, in energy regimes where the underlying classical unit cell undergoes a transition to chaos. Broken dynamical symmetries and the presence of chaos can diminish the feasibility of changing and controlling band structure in a wide variety of two-dimensional lattice-based devices, including two-dimensional solids, optical lattices, and photonic crystals.

  9. Evolution of full phononic band gaps in periodic cellular structures (United States)

    Wormser, Maximilian; Warmuth, Franziska; Körner, Carolin


    Cellular materials not only show interesting static properties, but can also be used to manipulate dynamic mechanical waves. In this contribution, the existence of phononic band gaps in periodic cellular structures is experimentally shown via sonic transmission experiment. Cellular structures with varying numbers of cells are excited by piezoceramic actuators and the transmitted waves are measured by piezoceramic sensors. The minimum number of cells necessary to form a clear band gap is determined. A rotation of the cells does not have an influence on the formation of the gap, indicating a complete phononic band gap. The experimental results are in good agreement with the numerically obtained dispersion relation.

  10. Laparoscopic Adjustable Silicone Gastric Banding Versus Vertical Banded Gastroplasty in Morbidly Obese Patients (United States)

    Morino, Mario; Toppino, Mauro; Bonnet, Gisella; del Genio, Gianmattia


    Objective: To compare, in a prospective, randomized, single-institution trial laparoscopic adjustable silicone gastric banding (LASGB) with laparoscopic vertical banded gastroplasty (LVBG) in morbidly obese patients. Summary Background Data: LASGB is a simple and safe procedure, but some reports have suggested disappointing long-term results. Despite the recent widespread use of LASGB, there are no prospective nor randomized trials comparing LASGB with other laparoscopic procedures. Methods: A total of 100 morbidly obese patients, with body mass index (BMI) 40 to 50 kg/m2, without compulsive eating, were randomized to either LASGB (n = 49) or LVBG (n = 51). Minimum follow-up was 2 years (mean 33.1 months). Results: There were no deaths or conversions in either group. Mean operative time was 94.2 minutes in LVBGs and 65.4 in LASGBs (P < 0.05). Early morbidity rate was lower in LASGBs (6.1%) versus LVBGs (9.8%) (P = 0.754). Mean hospital stay was shorter in LASGBs versus LVBGs: 3.7 days versus 6.6 (P < 0.05). Late complications rate in LVBGs was 14% (7 of 50) and in LASGBs 32.7% (16 of 49) (P < 0.05). The most frequent complication was the slippage of the band (18%). Late reoperations rate in LVBGs was 0% (0 of 50) versus 24.5% (12 of 49) in LASGBs (P < 0.001). Excess weight loss in LVBGs was, at 2 years, 63.5% and, at 3 years, 58.9%; in LASGBs, excess weight loss, respectively, was 41.4% and 39%. BMI in LVBGs was, at 2 years, 29.7 kg/m2 and, at 3 years, 30.7 kg/m2; in LASGBs, BMI was 34.8 kg/m2 at 2 years and 35.7 kg/m2 at 3 years. According to Reinhold’s classification, a residual excess weight <50% was achieved, at 2 years, in 74% of LVBG and 35% of LASGB (P < 0.001). Conclusions: This study demonstrates that, in patients with BMI 40 to 50 kg/m2, LASGB requires shorter operative time and hospital stay but LVBG is more effective in terms of late complications, reoperations, and weight loss. PMID:14631220

  11. Effective Tree Scattering at L-Band (United States)

    Kurum, Mehmet; ONeill, Peggy E.; Lang, Roger H.; Joseph, Alicia T.; Cosh, Michael H.; Jackson, Thomas J.


    For routine microwave Soil Moisture (SM) retrieval through vegetation, the tau-omega [1] model [zero-order Radiative Transfer (RT) solution] is attractive due to its simplicity and eases of inversion and implementation. It is the model used in baseline retrieval algorithms for several planned microwave space missions, such as ESA's Soil Moisture Ocean Salinity (SMOS) mission (launched November 2009) and NASA's Soil Moisture Active Passive (SMAP) mission (to be launched 2014/2015) [2 and 3]. These approaches are adapted for vegetated landscapes with effective vegetation parameters tau and omega by fitting experimental data or simulation outputs of a multiple scattering model [4-7]. The model has been validated over grasslands, agricultural crops, and generally light to moderate vegetation. As the density of vegetation increases, sensitivity to the underlying SM begins to degrade significantly and errors in the retrieved SM increase accordingly. The zero-order model also loses its validity when dense vegetation (i.e. forest, mature corn, etc.) includes scatterers, such as branches and trunks (or stalks in the case of corn), which are large with respect to the wavelength. The tau-omega model (when applied over moderately to densely vegetated landscapes) will need modification (in terms of form or effective parameterization) to enable accurate characterization of vegetation parameters with respect to specific tree types, anisotropic canopy structure, presence of leaves and/or understory. More scattering terms (at least up to first-order at L-band) should be included in the RT solutions for forest canopies [8]. Although not really suitable to forests, a zero-order tau-omega model might be applied to such vegetation canopies with large scatterers, but that equivalent or effective parameters would have to be used [4]. This requires that the effective values (vegetation opacity and single scattering albedo) need to be evaluated (compared) with theoretical definitions of

  12. X-band photonic band-gap accelerator structure breakdown experiment

    Directory of Open Access Journals (Sweden)

    Roark A. Marsh


    Full Text Available In order to understand the performance of photonic band-gap (PBG structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz. The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65  MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110  MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100  MV/m and a surface magnetic field of 890  kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14  MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  13. X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, Roark A.; /MIT /MIT /NIFS, Gifu /JAERI, Kyoto /LLNL, Livermore; Shapiro, Michael A.; Temkin, Richard J.; /MIT; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A.Dian; Tantawi, Sami G.; /SLAC


    In order to understand the performance of photonic band-gap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65 MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110 MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100 MV/m and a surface magnetic field of 890 kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14 MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  14. Gastroesophageal reflux in morbidly obese patients treated with gastric banding or vertical banded gastroplasty. (United States)

    Ovrebø, K K; Hatlebakk, J G; Viste, A; Bassøe, H H; Svanes, K


    OBJECTIVE: To compare gastric banding (GB) and vertical banded gastroplasty (VBG) with respect to postsurgical gastroesophageal reflux (GER) and to investigate the role of preexisting hiatus hernia. SUMMARY BACKGROUND DATA: GB and VBG have for a long time been used in the treatment of morbidly obese patients. The introduction of laparoscopic techniques has renewed the interest in these operations. The long-term results after GB have, however, been poor. VBG was suggested to have antireflux properties because it involves repositioning and retaining the gastroesophageal junction within the abdomen and constructing an elongated intraabdominal tube. METHODS: Forty-three morbidly obese patients accepted for GB or VBG were evaluated for GER before and at regular intervals after surgery. All patients were questioned about adverse symptoms and need for antireflux medication. Both before and after surgery, 24-hour pH measurement and upper gastrointestinal endoscopies were performed. RESULTS: The prevalence of heartburn and acid regurgitation among patients treated with GB increased from 14% and 13% to 63% and 69%, respectively. Heartburn and acid regurgitation were present before surgery in 32% and 23% of patients treated with VBG, percentages unchanged by the procedure. The 24-hour reflux time increased significantly from 6.4% to 30.9% in patients treated with GB but was essentially unchanged in patients treated with VBG. The prevalence of esophagitis after GB and VBG was 75% and 20%. Acid inhibitors were needed in 81% of patients after GB and 29% of patients after VBG. CONCLUSIONS: The prevalence of GER was unchanged by VBG, but VBG did not demonstrate antireflux properties. The incidence of GER increased markedly after GB. PMID:9671066

  15. Laparoscopic sleeve gastrectomy as revisional procedure for failed gastric banding and vertical banded gastroplasty. (United States)

    Iannelli, Antonio; Schneck, Anne Sophie; Ragot, Emila; Liagre, Arnaud; Anduze, Yves; Msika, Simon; Gugenheim, Jean


    The problem of revision of failed gastric banding (GB) and vertical banded gastroplasty (VBG) procedures has become a common situation in bariatric surgery. Laparoscopic sleeve gastrectomy (LSG) has been recently used to revise failed restrictive procedures. The objective of this study is to evaluate the results of LSG as revisional procedure for failed GB and VBG. A prospective held database was questioned regarding patients' demographic, indication for revision, conversion to open surgery, morbidity, percentage of excess weight loss (%EWL), evolution of comorbidities, and need for a second procedure after LSG. Forty-one patients, 34 women and seven men with a mean age of 42 years (range 19 to 63 years) and a mean body mass index at 49.9 kg/m(2) (range 35.9-63 kg/m(2)), underwent laparoscopic conversion of GB (36 patients) and VBG (five patients) into LSG. Indication for revisional surgery was insufficient weight loss in all the cases. All procedures were completed laparoscopically. There was no mortality and five patients (12.2%) developed complications (high leak, one patient; intra-abdominal abscess, three patients; and complicated incisional hernia, one patient). At a mean follow-up of 13.4 months, %EWL is on average 42.7% (range 4-76.1%). Six patients had a second procedure (four had laparoscopic duodenal switch, one had laparoscopic Roux-en-Y gastric bypass, and one had laparoscopic biliopancreatic diversion). Conversion of GB and VBG into LSG is feasible and safe. LSG is effective in the short term with a mean %EWL of 42.7% at 13.4 months. Long-term results of LSG as revisional procedure are awaited to establish its efficacy in the long term.

  16. Comparison of electron bands of hexagonal and cubic diamond (United States)

    Salehpour, M. R.; Satpathy, S.


    Using the local-density-theory and the linear-muffin-tin-orbitals method, we calculate the electron band structures of hexagonal (lonsdaleite) and cubic diamond. Even though the arrangement of atoms is very similar between the two crystal structures, we find significant differences in the electron bands, especially in the conduction bands. In particular, including estimated corrections on top of the local-density results, we find the lowest theoretical gap of hexagonal diamond to be 4.5 eV, i.e., a remarkable 1.1-eV drop as compared to that of cubic diamond. The lowest gap in the hexagonal structure is still indirect as in the cubic structure, but the gap is now from Γ to K. The reduction of the band gap should be observable in optical-absorption or reflectivity experiments.

  17. Formal Verification of Air Traffic Conflict Prevention Bands Algorithms (United States)

    Narkawicz, Anthony J.; Munoz, Cesar A.; Dowek, Gilles


    In air traffic management, a pairwise conflict is a predicted loss of separation between two aircraft, referred to as the ownship and the intruder. A conflict prevention bands system computes ranges of maneuvers for the ownship that characterize regions in the airspace that are either conflict-free or 'don't go' zones that the ownship has to avoid. Conflict prevention bands are surprisingly difficult to define and analyze. Errors in the calculation of prevention bands may result in incorrect separation assurance information being displayed to pilots or air traffic controllers. This paper presents provably correct 3-dimensional prevention bands algorithms for ranges of track angle; ground speed, and vertical speed maneuvers. The algorithms have been mechanically verified in the Prototype Verification System (PVS). The verification presented in this paper extends in a non-trivial way that of previously published 2-dimensional algorithms.

  18. Ice flow mapping with P-band SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Nielsen, Ulrik; Kusk, Anders


    -band SAR data have been acquired in Greenland, and both offset tracking and DInSAR have been applied to the full resolution data as well as to data degraded to the resolution of Biomass. Generally, ice velocity maps are successfully generated, but in the ablation zone, DInSAR fails in the melt season......Glacier and ice sheet dynamics are currently mapped with X-, C-, and L-band SAR. With the prospect of a P-band SAR, Biomass, to be launched within the next decade it is interesting to look into the potential of P-band for ice velocity mapping. In this paper first results are presented. Airborne P...

  19. Unoccupied band structure of wurtzite GaN(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Valla, T.; Johnson, P.D. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); Dhesi, S.S.; Smith, K.E. [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Doppalapudi, D.; Moustakas, T.D. [Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States); Shirley, E.L. [NIST, PHY B208, Gaithersburg, Maryland 20899 (United States)


    We report an inverse photoemission study of the unoccupied states of thin-film {ital n}-type wurtzite GaN. For incident electron energies below 30 eV, free-electron bands do not provide a good description of the initial state. However, using a calculated quasiparticle band structure for the initial state, we can obtain good agreement between our measurements and the calculated low-lying conduction bands. No evidence of unoccupied surface states is observed in the probed part of the Brillouin zone, confirming earlier angle resolved photoemission studies, which identified the surface states on GaN(0001) as occupied dangling bond states, resonant with the valence band. {copyright} {ital 1999} {ital The American Physical Society}

  20. Digital Conically Scanned L-Band Radar Project (United States)

    National Aeronautics and Space Administration — The proposed effort seeks to develop a digitally steered polarimetric phased array L-Band radar utilizing a novel, high performance architecture leveraging recent...

  1. CLPX-Airborne: Polarimetric Ku-Band Scatterometer (POLSCAT) Data (United States)

    National Aeronautics and Space Administration — This data set contains Ku-band polarimetric scatterometer (POLSCAT) data collected as part of the Cold Land Processes Field Experiment (CLPX) to enable the...

  2. Regularizing Inverse Preconditioners for Symmetric Band Toeplitz Matrices

    Directory of Open Access Journals (Sweden)

    Lotti G


    Full Text Available Image restoration is a widely studied discrete ill-posed problem. Among the many regularization methods used for treating the problem, iterative methods have been shown to be effective. In this paper, we consider the case of a blurring function defined by space invariant and band-limited PSF, modeled by a linear system that has a band block Toeplitz structure with band Toeplitz blocks. In order to reduce the number of iterations required to obtain acceptable reconstructions, in 13 an inverse Toeplitz preconditioner for problems with a Toeplitz structure was proposed. The cost per iteration is of operations, where is the pixel number of the 2D image. In this paper, we propose inverse preconditioners with a band Toeplitz structure, which lower the cost to and in experiments showed the same speed of convergence and reconstruction efficiency as the inverse Toeplitz preconditioner.

  3. Revealing Slip Bands In A Metal-Matrix/Fiber Composite (United States)

    Lerch, Bradley A.


    Experimental procedure includes heat treatments and metallographic techniques developed to facilitate studies of deformation of metal-matrix/fiber composite under stress. Reveals slip bands, indicative of plastic flow occurring in matrix during mechanical tests of specimens of composite.

  4. The ν_3 Fundamental Vibrational Band of Scccs Revisited (United States)

    Salomon, Thomas; Dudek, John B.; Thorwirth, Sven


    The ν_3 fundamental vibrational band of carbon subsulfide, SCCCS, first studied by Holland and collaborators has been reinvestigated using a combination of laser ablation production, free-jet expansion and quantum cascade laser spectroscopy. In addition to the fundamental band (located at 2100 cm^{-1}) and associated hot bands originating from the lowest bending mode ν_7, the hot bands from the two energetically higher-lying bending modes ν_5 and ν_6 have been observed for the first time as has the S^{13}CCCS isotopic species. F. Holland, M. Winnewisser, C. Jarman, H. W. Kroto, and K. M. T. Yamada 1988, J. Mol. Spectrosc. 130, 344 F. Holland and M. Winnewisser 1991, J. Mol. Spectrosc. 147, 496

  5. L and P Band MMIC T/R Module Project (United States)

    National Aeronautics and Space Administration — This proposal is specifically written to address the need for improved L and P band T/R modules for use in active microwave surveillance of earth surface and...

  6. Ka-Band MMIC T/R Module Project (United States)

    National Aeronautics and Space Administration — This Phase II proposal is presented as the follow on to the Phase I SBIR contract number NNC06CB21C entitled "Ka-band MMIC T/R Module" For active microwave...

  7. L and P Band MMIC T/R Module Project (United States)

    National Aeronautics and Space Administration — This proposal is specifically written to address the need for improved L and P band T/R modules. The solicitation calls for investigation and development of core...

  8. Developmental Changes in Infants' Sensitivity to Octave-Band Noises. (United States)

    Trehub, Sandra E.; And Others


    Localization responses to octave-band noises with center frequencies at 200, 400, 1000, 2000, 4000, and 10,000 Hz were obtained from infants 6, 12, and 18 months old in order to investigate infants' auditory sensitivity. (MP)

  9. 2011 - Color & Infrared (4 band) - Statewide NAIP (1m) (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The NAIP_1M_CLRIR_2011 dataset is a 1:40000 scale (1 meter) truecolor and infrared (4 band) NAIP imagery product acquired during the summer/fall...

  10. Thermodynamics of a Simple Rubber-Band Heat Engine (United States)

    Mullen, J. G.; And Others


    Outlines the basic engine design and nomenclature, develops some relations between the state parameters of the rubber-band system, defines engine efficiency, and compares the Archibald engine with the Carnot engine. (GS)

  11. Short-phase anomalies in intermittent band switching

    NARCIS (Netherlands)

    Post, T.; Capel, H.W.; van der Weele, J.P.


    The distribution of phase lengths t for intermittent band switching is investigated for small t. Some typical deviations from exponential behaviour are reported, in particular the occurrence of a minimal phase length with enhanced probability.

  12. The Cassini Ka-band gravitational wave experiments

    CERN Document Server

    Tinto, M


    Cassini, a joint American/European interplanetary scientific mission to Saturn, will be continuously and coherently tracked for 40 days during its solar oppositions in the next three years, starting on 26 November 2001. Doppler tracking searches for gravitational waves in the millihertz frequency band will be performed by using newly implemented Ka-band (approx 32 GHz) microwave capabilities on the ground and onboard the spacecraft. Use of the Ka-band coherent microwave link will suppress solar plasma scintillations to levels below those identified by remaining instrumental noise sources, making the Cassini Doppler tracking experiments the most sensitive searches for gravitational waves ever attempted in the millihertz frequency band. This paper provides a short review of the Doppler response to gravitational radiation, the noise sources and their transfer functions into the Doppler observable and estimates of the anticipated Cassini Doppler tracking sensitivities to gravitational radiation.

  13. Photonic band gaps in body-centered-cubic structures (United States)

    Hornreich, R. M.; Shtrikman, S.; Sommers, C.


    Photonic energy bands in body-centered-cubic bcc materials are analyzed by considering structures having O8 (I4132) space-group symmetry. Such structures can be realized physically by interlacing cylindrical elements oriented along crystallographic axes. In addition to heterogeneous systems composed entirely of dielectric materials, the possibility of using conducting materials (particularly at microwave frequencies) is studied. We find that (a) band gaps occur in heterogeneous dielectric systems when materials having a dielectric constant of 100 or more are properly placed in the O8 unit cell, and (b) utilizing conducting materials can significantly widen the excluded frequency band, the result being that band gaps of more than 20% should be attainable with O8 structures at microwave frequencies. Experimental verification of these results should be possible in this spectral region.

  14. W-band Solid State Transceiver for Cloud Radar Project (United States)

    National Aeronautics and Space Administration — The proposed work focuses on the evaluation and testing of the W-band SSPA on the current airborne Cloud Radar System (CRS) transceiver so that it can be operated...

  15. Universal phase diagrams with superconducting domes for electronic flat bands (United States)

    Löthman, Tomas; Black-Schaffer, Annica M.


    Condensed matter systems with flat bands close to the Fermi level generally exhibit, due to their very large density of states, extraordinarily high critical ordering temperatures of symmetry-breaking orders, such as superconductivity and magnetism. Here we show that the critical temperatures follow one of two universal curves with doping away from a flat band depending on the ordering channel, which completely dictates both the general order competition and the phase diagram. Notably, we find that orders in the particle-particle channel (superconducting orders) survive decisively farther than orders in the particle-hole channel (magnetic or charge orders) because the channels have fundamentally different polarizabilities. Thus, even if a magnetic or charge order initially dominates, superconducting domes are still likely to exist on the flanks of flat bands. We apply these general results to both the topological surface flat bands of rhombohedral ABC-stacked graphite and to the Van Hove singularity of graphene.

  16. Experimental study of shear bands formation in a granular material

    Directory of Open Access Journals (Sweden)

    Nguyen Thai Binh


    Full Text Available We present an experimental investigation of the formation of shear bands in a granular sample submitted to a biaxial test. Our principal result is the direct observation of the bifurcation at the origin of the localization process in the material. At the bifurcation, the shear band is spatially extended: we observe a breaking of symmetry without any sudden localization of the deformation in a narrow band. Our work thus allows to clearly distinguish different phenomena: bifurcation which is a ponctual event which occurs before the peak, localization which is a process that covers a range of deformation of several percents during which the peak occurs and finally stationary shear bands which are well-defined permanent structures that can be observed at the end of the localization process, after the peak.

  17. Chromosome banding of two Litoria species (Anura, Hylidae

    Directory of Open Access Journals (Sweden)

    Wanpen Kakampuy


    Full Text Available This research was the first cytogenetic studies of green-eyed tree frog (Litoria genimaculata and Nyakala frog(L. nyakalensis. The mitotic chromosomes were prepared directly from bone marrow after in vivo colchicine treatment andanalysed following conventional, silver staining and C-banding techniques. These species showed similar karyotypes with2n=26, the fundamental number (NF are 52 chromosomes and Ag-NOR positions located in the short arm near centromeresof chromosome pair 7 in L. genimaculata and in the long arm near telomeres of chromosome pair 9 in L. nyakalensis. TheC-banded karyotypes showed heterochromatin bands at the centromeres and telomeres of all chromosomes. Both specieswere characterized by the number and position of constitutive heterochromatin in the karyotypes. The mitotic karyotypes ofL. genimaculata exhibited greater amounts of C-band positive heterochromatin than L. nyakalensis.

  18. A rare combination of amniotic constriction band with osteogenesis imperfecta. (United States)

    Shah, Krupa Hitesh; Shah, Hitesh


    Amniotic constriction bands and osteogenesis imperfecta are disorders arising from a collagen defect. We report a rare association of amniotic bands with osteogenesis imperfecta in a child. The child was born with multiple amniotic bands involving the right leg, both hands and both feet. Multiple fractures of long bones of lower limbs occurred in childhood due to trivial trauma. Deformities of the femur and tibia due to malunion with osteopenia and blue sclerae were present. The patient was treated with z plasty of constriction band of the right tibia and bisphosphonate for osteogenesis imperfecta. This rare association of both collagen diseases may provide further insight for the pathogenesis of these diseases. 2015 BMJ Publishing Group Ltd.

  19. Observation of a novel stapler band in 75As

    Directory of Open Access Journals (Sweden)

    C.G. Li


    Full Text Available The heavy ion fusion–evaporation reaction study for the high-spin spectroscopy of 75As has been performed via the reaction channel 70Zn(9Be, 1p3n75As at a beam energy of 42 MeV. The collective structure especially a dipole band in 75As is established for the first time. The properties of this dipole band are investigated in terms of the self-consistent tilted axis cranking covariant density functional theory. Based on the theoretical description and the examination of the angular momentum components, this dipole band can be interpreted as a novel stapler band, where the valence neutrons in (1g9/2 orbital rather than the collective core are responsible for the closing of the stapler of angular momentum.

  20. A Small UWB Antenna with Dual Band-Notched Characteristics

    Directory of Open Access Journals (Sweden)

    J. Xu


    Full Text Available A small novel ultrawideband (UWB antenna with dual band-notched functions is proposed. The dual band rejection is achieved by etching two C-shaped slots on the radiation patch with limited area. A single band-notched antenna is firstly presented, and then an optimized dual band-notched antenna is presented and analyzed. The measured VSWR shows that the proposed antenna could operate from 3.05 to 10.7 GHz with VSWR less than 2, except two stopbands at 3.38 to 3.82 GHz and 5.3 to 5.8 GHz for filtering the WiMAX and WLAN signals. Radiation patterns are simulated by HFSS and verified by CST, and quasiomnidirectional radiation patterns in the H-plane could be observed. Moreover, the proposed antenna has a very compact size and could be easily integrated into portable UWB devices.