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Sample records for integral al manejo

  1. 75 FR 13147 - Integrity Life Insurance Company, et al.;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... COMMISSION Integrity Life Insurance Company, et al.; Notice of Application March 10, 2010. AGENCY: Securities...: Integrity Life Insurance Company (``Integrity''), Separate Account I of Integrity Life Insurance Company (``Integrity Separate Account I''), Separate Account II of Integrity Life Insurance Company...

  2. Surface integrity after pickling and anodization of Ti-6Al-4V titanium alloy

    NASA Astrophysics Data System (ADS)

    Vermesse, Eric; Mabru, Catherine; Arurault, Laurent

    2013-11-01

    The surface integrity of Ti-6Al-4V titanium alloy was studied at different stages of surface treatments, especially pickling and compact anodization, through surface characteristics potentially worsening fatigue resistance.

  3. Characterization of Al/CuO nanoenergetic multilayer films integrated with semiconductor bridge for initiator applications

    NASA Astrophysics Data System (ADS)

    Zhu, Peng; Shen, Ruiqi; Ye, Yinghua; Fu, Shuai; Li, Dongle

    2013-05-01

    This paper describes the ignition characteristics of Al/CuO nanoenergetic multilayer films (nEMFs) integrated with semiconductor bridge (SCB). The as-deposited Al/CuO nEMFs were identified with SEM and differential scanning calorimetry. Results show that distinct Al/CuO nEMFs are sputter deposited in a layered geometry, and the Al/CuO nEMFs gives a reaction heat equal to 2181 J/g. The firing experiments show that Al/CuO nEMFs have no influence on the electrical properties of SCB. Furthermore, the rapid combustion of Al/CuO nEMFs is able to assist SCB generating high-temperature plasma and products, such that enhance the ignition reliability.

  4. Integrating AlGaN/GaN high electron mobility transistor with Si: A comparative study of integration schemes

    SciTech Connect

    Mohan, Nagaboopathy; Raghavan, Srinivasan; Manikant,; Soman, Rohith

    2015-10-07

    AlGaN/GaN high electron mobility transistor stacks deposited on a single growth platform are used to compare the most common transition, AlN to GaN, schemes used for integrating GaN with Si. The efficiency of these transitions based on linearly graded, step graded, interlayer, and superlattice schemes on dislocation density reduction, stress management, surface roughness, and eventually mobility of the 2D-gas are evaluated. In a 500 nm GaN probe layer deposited, all of these transitions result in total transmission electron microscopy measured dislocations densities of 1 to 3 × 10{sup 9}/cm{sup 2} and <1 nm surface roughness. The 2-D electron gas channels formed at an AlGaN-1 nm AlN/GaN interface deposited on this GaN probe layer all have mobilities of 1600–1900 cm{sup 2}/V s at a carrier concentration of 0.7–0.9 × 10{sup 13}/cm{sup 2}. Compressive stress and changes in composition in GaN rich regions of the AlN-GaN transition are the most effective at reducing dislocation density. Amongst all the transitions studied the step graded transition is the one that helps to implement this feature of GaN integration in the simplest and most consistent manner.

  5. Characteristics of the Energetic Igniters Through Integrating Al/NiO Nanolaminates on Cr Film Bridge

    NASA Astrophysics Data System (ADS)

    Yan, YiChao; Shi, Wei; Jiang, HongChuan; Xiong, Jie; Zhang, WanLi; Li, Yanrong

    2015-12-01

    The energetic igniters through integrating Al/NiO nanolaminates on Cr film bridges have been investigated in this study. The microstructures demonstrate well-defined geometry and sharp interfaces. The depth profiles of the X-ray photoelectron spectroscopy of Al/NiO nanolaminates annealed at 550 °C with a bilayer thickness of 250 nm show that the interdiffusion between the Al layer and NiO layer has happened and the annealing temperature cannot provide enough energy to make the diffusion process much more complete. The electrical explosion characteristics employing a capacitor discharge firing set at the optimized charging voltage of 40 V show that the flame duration time is about 700 μs, and an excellent explosion performance is obtained for (Al/NiO)n/Cr igniters with a bilayer thickness of 1000 nm.

  6. Ru/Al Multilayers Integrate Maximum Energy Density and Ductility for Reactive Materials.

    PubMed

    Woll, K; Bergamaschi, A; Avchachov, K; Djurabekova, F; Gier, S; Pauly, C; Leibenguth, P; Wagner, C; Nordlund, K; Mücklich, F

    2016-01-01

    Established and already commercialized energetic materials, such as those based on Ni/Al for joining, lack the adequate combination of high energy density and ductile reaction products. To join components, this combination is required for mechanically reliable bonds. In addition to the improvement of existing technologies, expansion into new fields of application can also be anticipated which triggers the search for improved materials. Here, we present a comprehensive characterization of the key parameters that enables us to classify the Ru/Al system as new reactive material among other energetic systems. We finally found that Ru/Al exhibits the unusual integration of high energy density and ductility. For example, we measured reaction front velocities up to 10.9 (± 0.33) ms(-1) and peak reaction temperatures of about 2000 °C indicating the elevated energy density. To our knowledge, such high temperatures have never been reported in experiments for metallic multilayers. In situ experiments show the synthesis of a single-phase B2-RuAl microstructure ensuring improved ductility. Molecular dynamics simulations corroborate the transformation behavior to RuAl. This study fundamentally characterizes a Ru/Al system and demonstrates its enhanced properties fulfilling the identification requirements of a novel nanoscaled energetic material.

  7. Ru/Al Multilayers Integrate Maximum Energy Density and Ductility for Reactive Materials

    PubMed Central

    Woll, K.; Bergamaschi, A.; Avchachov, K.; Djurabekova, F.; Gier, S.; Pauly, C.; Leibenguth, P.; Wagner, C.; Nordlund, K.; Mücklich, F.

    2016-01-01

    Established and already commercialized energetic materials, such as those based on Ni/Al for joining, lack the adequate combination of high energy density and ductile reaction products. To join components, this combination is required for mechanically reliable bonds. In addition to the improvement of existing technologies, expansion into new fields of application can also be anticipated which triggers the search for improved materials. Here, we present a comprehensive characterization of the key parameters that enables us to classify the Ru/Al system as new reactive material among other energetic systems. We finally found that Ru/Al exhibits the unusual integration of high energy density and ductility. For example, we measured reaction front velocities up to 10.9 (±0.33) ms−1 and peak reaction temperatures of about 2000 °C indicating the elevated energy density. To our knowledge, such high temperatures have never been reported in experiments for metallic multilayers. In situ experiments show the synthesis of a single-phase B2-RuAl microstructure ensuring improved ductility. Molecular dynamics simulations corroborate the transformation behavior to RuAl. This study fundamentally characterizes a Ru/Al system and demonstrates its enhanced properties fulfilling the identification requirements of a novel nanoscaled energetic material. PMID:26822309

  8. An integrated water resources management strategy for Al-Ain City, United Arab Emirates

    NASA Astrophysics Data System (ADS)

    Mohamed, M. M.

    2014-09-01

    Al-Ain is the second largest city in the Emirate of Abu Dhabi and the third in the UAE. Currently, desalination plants are the only source of drinking water in the city with an average daily supply of 170 MIG. Recently, Abu Dhabi Urban Planning Council (UPC) released Al-Ain 2030 Plan. Projects suggested in this plan, over and above the expected natural population growth, will certainly put additional stress on the water resources in the city. Therefore, Al-Ain city seems to be in urgent need for an integrated water resources management strategy towards achieving sustainable development. This strategy will contain three main components; namely, a Water Demand Forecasting Model (WDFM), a Water Budget Model (WBM), and a Water Resources Optimization Model (WROM). The main aim of this paper is to present the WBM that estimates all inflows and outflows to assess water resources sustainability in the city.

  9. Writing errors in ALS related to loss of neuronal integrity in the anterior cingulate gyrus.

    PubMed

    Yabe, Ichiro; Tsuji-Akimoto, Sachiko; Shiga, Tohru; Hamada, Shinsuke; Hirata, Kenji; Otsuki, Mika; Kuge, Yuji; Tamaki, Nagara; Sasaki, Hidenao

    2012-04-15

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by loss of motor neuron and various cognitive deficits including writing errors. (11)C-flumazenil (FMZ), the positron emission tomography (PET) GABA(A) receptor ligand, is a marker of cortical dysfunction. The objective of this study was to investigate the relationship between cognitive deficits and loss of neuronal integrity in ALS patients using (11)C-FMZ PET. Ten patients with ALS underwent both neuropsychological tests and (11)C-FMZ-PET. The binding potential (BP) of FMZ was calculated from (11)C-FMZ PET images. There were no significant correlations between the BP and most test scores except for the writing error index (WEI), which was measured by the modified Western Aphasia Battery - VB (WAB-IVB) test. The severity of writing error was associated with loss of neuronal integrity in the bilateral anterior cingulate gyrus with mild right predominance (n=9; x=4 mm, y=36 mm, z=4 mm, Z=5.1). The results showed that writing errors in our patients with ALS were related to dysfunction in the anterior cingulate gyrus.

  10. Investigation on Tool Life and Surface Integrity when Drilling Ti-6Al-4V and Ti-5Al-4V-Mo/Fe

    NASA Astrophysics Data System (ADS)

    Rahim, Erween Abd.; Sharif, Safian

    Machinability study on the drilling of two alpha beta titanium alloy series, Ti-6Al-4V and Ti-5Al-4V-0.6Mo-0.4Fe were conducted using an uncoated carbide drill. The effect of cutting speed on tool life, tool failure mode, cutting force and surface integrity of the drilled surface were discussed. Results showed that Ti-6Al-4V exhibited a more superior machinability property when compared to the Ti-5Al-4V-Mo/Fe alloy system. The tool wear progression when drilling Ti-6Al-4V was lower than that of Ti-5Al-4V-Mo/Fe. The tool experienced similar failure mechanisms which were non uniform wear and chipping when drilling both alloys. At high cutting speed and after prolonged machining, excessive plastic deformation was observed on the subsurface layer of the drilled surface which resulted in increase in the hardness value.

  11. AlGaInAs MOVPE selective area growth for photonic integrated circuits

    NASA Astrophysics Data System (ADS)

    Decobert, Jean; Binet, Guillaume; Maia, Alvaro D. B.; Lagrée, Pierre-Yves; Kazmierski, Christophe

    2015-04-01

    We developed a generic photonic integration platform based on selective area growth (SAG) by metal organic vapor-phase epitaxy (MOVPE) of AlGaInAs/InP multiple quantum well (MQW) material. For efficient and predictive band gap engineering of photonic integrated circuits, different SAG zones of active and passive function heterostructures are precisely modeled and characterized. With the vapor-phase diffusion model, using numerical simulations of finite volumes, we extracted the three effective diffusion lengths of Al, Ga, and In species. In our growth conditions, these lengths were 32, 65, and 14 μm, respectively. The Kardar-Parisi-Zhang (KPZ) equation, a classic approach to describe the growing interface profile, is used. AlGaInAs MQW properties are then simulated in terms of thickness, composition, band gap, and biaxial strain variations. Highly resolved μ-photoluminescence and optical interferometer microscopy measurements confirm the validity of the band gap and thickness variations for both bulk and MQW layers. A new diffractometer, with a submillimeter X-ray spot, was used to study the structural properties of the MQW in the center of the SAG area. As an application, we present the realization and operation of full-monolithic high-speed advanced modulation format transmitters based on novel prefixed optical phase switching by fast electro-absorption modulators.

  12. Energetic igniters realized by integrating Al/CuO reactive multilayer films with Cr films

    NASA Astrophysics Data System (ADS)

    Zhu, Peng; Shen, Ruiqi; Ye, Yinghua; Zhou, Xiang; Hu, Yan

    2011-10-01

    This paper deals with the energetic igniters realized by integrating Al/CuO reactive multilayer films (RMFs) with Cr Films, which could be used in micro-ignition system. The as-deposited Al/CuO RMFs has been characterized with varied analytical techniques. Results show that distinct Al/CuO RMFs is sputter deposited in a layered geometry, and the Al/CuO RMFs gives a heat of reaction equal to 2760 J/g. The structure of igniter is similar to a capacitor, which may place an electric field across the igniter and allow the instantaneous large-current to drift through the igniter. Firing characteristics of the igniter were accomplished using constant voltage firing set. The experiment shows that the ignition delay time and total released energy of the igniter discharged in 40 V are 0.7 ms and 482.34 mJ, respectively. In addition, the explosion temperature could keep an approximately constant value of 3500 °C for 1.4 ms.

  13. Structure-Property Correlations in Al-Li Alloy Integrally Stiffened Extrusions

    NASA Technical Reports Server (NTRS)

    Hales, Stephen J.; Hafley, Robert A.

    2001-01-01

    The objective of this investigation was to establish the relationship between mechanical property anisotropy, microstructure and crystallographic texture in integrally 'T'-stiffened extruded panels fabricated from the Al-Li alloys 2195, 2098 and 2096. In-plane properties were measured as a function of orientation at two locations in the panels, namely mid-way between (Skin), and directly beneath (Base), the integral 'T' stiffeners. The 2195 extrusion exhibited the best combination of strength and toughness, but was the most anisotropic. The 2098 extrusion exhibited lower strength and comparable toughness, but was more isotropic than 2195. The 2096 extrusion exhibited the lowest strength and poor toughness, but was the most isotropic. All three alloys exhibited highly elongated grain structures and similar location-dependent variations in grain morphology. The textural characteristics comprised a beta + <100> fiber texture, similar to rolled product, in the Skin regions and alpha <111> + <100> fiber texture, comparable to axisymmetric extruded product, in the Base regions. In an attempt to quantitatively correlate texture with yield strength anisotropy, the original 'full constraint' Taylor model and a variant of the 'relaxed constraint' model, explored by Wert et al., were applied to the data. A comparison of the results revealed that the Wert model was consistently more accurate than the Taylor model.

  14. Pre-Eminent Curriculum in Islamic Basic School Integrated Comparative Studies in Islamic Basic School Integrated Al-Izzah Serang and Al-Hanif Cilegon, Banten, Indonesia

    ERIC Educational Resources Information Center

    Fauz, Anis; Hasbullah

    2016-01-01

    Compare to General SD (Primary school), the superiority of SD Islam Terpadu (Integrated Islamic Primary School) lies on the development of the curriculum and learning that is more emphasize on integrated curriculum and integrated learning. Curriculum model applied in Sekolah Dasar Islam Terpadu (SDIT) is integrated curriculum. This curriculum is…

  15. Integration of AlN with molybdenum electrodes and sacrificial amorphous silicon release using XeF2

    NASA Astrophysics Data System (ADS)

    Sharma, Jaibir; Fernando, Sanchitha; Tan, Wee Ming

    2014-03-01

    This paper presents a new post-CMOS-compatible integration scheme for AlN-based MEMS devices. The proposed scheme integrates molybdenum (Mo) bottom electrodes with an amorphous silicon (a-Si) sacrificial layer, which is etched using XeF2 to release the MEMS structures. This integration approach faces two potential issues, which are solved in this work: (i) poor adhesion of AlN with a-Si, and (ii) XeF2 attacking the Mo electrode during the removal of the a-Si sacrificial layer. The adhesion problem was solved by introducing a thin oxide layer between a-Si and AlN. The sidewalls of the Mo electrodes were protected by a 0.2 µm thick SiN spacer layer from the XeF2 attack. The robustness of the integration scheme was verified by fabricating an FBAR band pass filter. RF measurements on the FBAR band pass filter show that the proposed integration works well and can be utilized for other AlN-based MEMS devices in post-CMOS applications.

  16. Response to Niklasson's comment on Lin, et al. (2012) : "the relation between postural movement and bilateral motor integration".

    PubMed

    Lin, Chin-Kai; Kuo, Bor-Chen; Wu, Huey-Min

    2014-10-01

    In the study of Lin, Wu, Lin, Wu, Wu, Kuo, and Yeung (2012 ), the relationship between the validity of postural movement and bilateral motor integration in terms of sensory integration theory was examined. Postural movement is the ability to use the antigravity postures required for stabilization of the neck, trunk and upper extremities via muscle co-contractions in the neck and upper extremities, and balance. Niklasson's (2013 ) comment argued that postural movement should include primitive reflexes in terms of the general abilities approach. Niklasson (2013 ) focused on the efficacy of the treatment rather than the theoretical frameworks implied in the therapeutic activities. For that purpose Lin, et al. (2012 ) used sensory integration as the theoretical foundation, and the relationship between postural movement and bilateral motor integration was assessed via empirical data. The result of Lin, et al. (2012 ) was offered as a theoretical reference for therapeutic activities.

  17. Characteristics of Al substituted nanowires fabricated by self-aligned growth for future large scale integration interconnects

    NASA Astrophysics Data System (ADS)

    Kudo, Hiroshi; Kurahashi, Teruo

    2011-06-01

    Substituted Al nanowires for use in future large scale integration interconnects were fabricated by self-aligned growth. The resistivity of an Al substituted nanowire 80 nm in width, 100 nm in height, and 20 μm in length was 4.7 μΩ cm, which is 48% lower than that of an Al nanowire with the same dimensions fabricated using a bottom-up approach. The variation in the resistivity was in a narrow range (14%) over a Si wafer. The TEM imaging revealed that the Al substituted nanowire had a bamboo-like structure with grains larger than 1.6 μm. The electromigration activation energy was 0.72 eV, which is comparable to that of a pure Al wire with a bamboo-like structure. The product of the critical current density and wire length was 1.3 × 103 A/cm at 250 °C; 2.1 times higher than that of a pure Al wire with a polycrystalline structure. The acceleration of electromigration due to current density was 2.0, indicating that incubation time dominates electromigration lifetime. The prolonged incubation time observed in the electromigration test is attributed to the reduction in electromigration-induced mass transport due to the microstructure of the Al substituted nanowire. Even the formation of a small void immediately after incubation may be a fatal defect for nanoscale Al wires.

  18. Surface Integrity of Titanium Alloy Ti-6Al-4 V in Ball end Milling

    NASA Astrophysics Data System (ADS)

    Mhamdi, M.-B.; Boujelbene, M.; Bayraktar, E.; Zghal, A.

    With the evolution of machine tools and the emergence of new cutting tools such as cermet, CBN; and in framework of the production of parts with complex geometry, the manufacturers were able to realize more and more parts of complex shape. The multi-axis machining is the main technique for achieving the free form; in fact the multi-axis milling with ball end tools attracts the interest of the aerospace industry and the mussel industry which continues to seek ways to improve the surface quality of finished parts. The titanium alloy is widely used in aerospace industry is the subject of this study in fact, the integrity of the surfaces of parts produced by multi-axis milling is an issue more relevant than ever for the aerospace industry. This paper aims to study the influence of the tool position and the parameters cutting precisely the speed feed Vf, the engagement of the tool on the roughness 3 D, micro-hardness and microstructure alteration created in sub-surface during the milling of concave surface of titanium alloy type Ti-6Al-4 V.

  19. Technology of integrated self-aligned E/D-mode n++GaN/InAlN/AlN/GaN MOS HEMTs for mixed-signal electronics

    NASA Astrophysics Data System (ADS)

    Blaho, M.; Gregušová, D.; Haščík, Š.; Seifertová, A.; Ťapajna, M.; Šoltýs, J.; Šatka, A.; Nagy, L.; Chvála, A.; Marek, J.; Carlin, J.-F.; Grandjean, N.; Konstantinidis, G.; Kuzmík, J.

    2016-06-01

    We describe the technology and performance of integrated enhancement/depletion (E/D)-mode n++GaN/InAlN/AlN/GaN HEMTs with a self-aligned metal-oxide-semiconductor (MOS) gate structure. An identical starting epi-structure was used for both types of devices without the additional need for a contacts regrowth. The n++GaN cap layer was etched away in the gate trenches of the E-mode HEMT while it was left intact for the D-mode HEMT. The plasma etching process was shown to be highly selective between the cap and the InAlN barrier and also to polish the InAlN surface. However, different GaN etching initiation times inside and outside the mesa region were obtained. Gate contacts were isolated using a dielectric layer deposited at low temperature through an e-beam resist to retain the self-aligned approach. Feasibility of the approach for future fast GaN-based mixed-signal electronic circuits was shown by obtaining alternative HEMT threshold voltage values of +0.8 V and -2.6 V, invariant maximal output current of ˜0.35 A mm-1 despite large source-to-drain distances and by demonstrating a functional logic invertor.

  20. Technology of integrated self-aligned E/D-mode n++GaN/InAlN/AlN/GaN MOS HEMTs for mixed-signal electronics

    NASA Astrophysics Data System (ADS)

    Blaho, M.; Gregušová, D.; Haščík, Š.; Seifertová, A.; Ťapajna, M.; Šoltýs, J.; Šatka, A.; Nagy, L.; Chvála, A.; Marek, J.; Carlin, J.-F.; Grandjean, N.; Konstantinidis, G.; Kuzmík, J.

    2016-06-01

    We describe the technology and performance of integrated enhancement/depletion (E/D)-mode n++GaN/InAlN/AlN/GaN HEMTs with a self-aligned metal-oxide-semiconductor (MOS) gate structure. An identical starting epi-structure was used for both types of devices without the additional need for a contacts regrowth. The n++GaN cap layer was etched away in the gate trenches of the E-mode HEMT while it was left intact for the D-mode HEMT. The plasma etching process was shown to be highly selective between the cap and the InAlN barrier and also to polish the InAlN surface. However, different GaN etching initiation times inside and outside the mesa region were obtained. Gate contacts were isolated using a dielectric layer deposited at low temperature through an e-beam resist to retain the self-aligned approach. Feasibility of the approach for future fast GaN-based mixed-signal electronic circuits was shown by obtaining alternative HEMT threshold voltage values of +0.8 V and ‑2.6 V, invariant maximal output current of ∼0.35 A mm‑1 despite large source-to-drain distances and by demonstrating a functional logic invertor.

  1. Rare-earth-ion-doped Al IIO 3 waveguides for active integrated optical devices

    NASA Astrophysics Data System (ADS)

    Bradley, Jonathan D. B.; Ay, Feridun; Blauwendraat, Tom; Wörhoff, Kerstin; Pollnau, Markus

    2007-06-01

    Reactively co-sputtered amorphous Al IIO 3 waveguide layers with low propagation losses have been deposited. In order to define channel waveguides in such Al IIO 3 films, the etching behaviour of Al IIO 3 has been investigated using an inductively coupled reactive ion etch system. The etch rate of Al IIO 3 and possible mask materials was studied by applying various common process gases and combinations of these gases, including CF 4/O II, BCl 3, BCl 3/HBr and Cl II. Based on a comparison of the etch rates and patterning feasibility of the different mask materials, a BCl 3/HBr plasma and and standard resist mask were used to fabricate channel waveguide structures. The etched structures exhibit straight sidewalls with minimal roughness and etch depths of up to 530 nm, sufficient for defining waveguides with strong optical confinement and low bending losses. Low additional propagation losses were measured in single-mode Al IIO 3 ridge waveguides defined using the developed etch process. In initial investigations, Al IIO 3:Er layers fabricated using the same deposition method applied for the undoped layers show typical emission cross-sections, low green upconversion luminescence and lifetimes up to 7 ms.

  2. Magnetotransport Properties of Epitaxial Ge/AlAs Heterostructures Integrated on GaAs and Silicon.

    PubMed

    Hudait, Mantu K; Clavel, Michael; Goley, Patrick S; Xie, Yuantao; Heremans, Jean J

    2015-10-14

    The magnetotransport properties of epitaxial Ge/AlAs heterostructures with different growth conditions and substrate architectures have been studied under ±9 T magnetic field and at 390 mK temperature. Systematic mobility measurements of germanium (Ge) epilayers grown on GaAs substrates at growth temperatures from 350 to 450 °C allow us to extract a precise growth window for device-quality Ge, corroborated by structural and morphological properties. Our results on Si substrate using a composite metamorphic AlAs/GaAs buffer at 400 °C Ge growth temperature, show that the Ge/AlAs system can be tailored to have a single carrier transport while keeping the charge solely in the Ge layer. Single carrier transport confined to the Ge layer is demonstrated by the weak-localization quantum correction to the conductivity observed at low magnetic fields and 390 mK temperature. The weak localization effect points to a near-absence of spin-orbit interaction for carriers in the electronically active layer and is used here for the first time to pinpoint Ge as this active layer. Thus, the epitaxial Ge grown on Si using AlAs/GaAs buffer architecture is a promising candidate for next-generation energy-efficient fin field-effect transistor applications.

  3. High-κ Al2O3 material in low temperature wafer-level bonding for 3D integration application

    NASA Astrophysics Data System (ADS)

    Fan, J.; Tu, L. C.; Tan, C. S.

    2014-03-01

    This work systematically investigated a high-κ Al2O3 material for low temperature wafer-level bonding for potential applications in 3D microsystems. A clean Si wafer with an Al2O3 layer thickness of 50 nm was applied as our experimental approach. Bonding was initiated in a clean room ambient after surface activation, followed by annealing under inert ambient conditions at 300 °C for 3 h. The investigation consisted of three parts: a mechanical support study using the four-point bending method, hermeticity measurements using the helium bomb test, and thermal conductivity analysis for potential heterogeneous bonding. Compared with samples bonded using a conventional oxide bonding material (SiO2), a higher interfacial adhesion energy (˜11.93 J/m2) and a lower helium leak rate (˜6.84 × 10-10 atm.cm3/sec) were detected for samples bonded using Al2O3. More importantly, due to the excellent thermal conductivity performance of Al2O3, this technology can be used in heterogeneous direct bonding, which has potential applications for enhancing the performance of Si photonic integrated devices.

  4. Efecto del Programa de Entrenamiento “Manejo del Dolor” en la Documentación de Enfermería en el Expediente Electrónico

    PubMed Central

    Monsiváis, María Guadalupe Moreno; Guzmán, Ma. Guadalupe Interial; Flores, Paz Francisco Sauceda; Arreola, Leticia Vázquez

    2012-01-01

    Resumen En el presente trabajo se muestra la importancia de entrenar al personal de enfermería para mejorar la documentación en el expediente electrónico. Se eligió el manejo del dolor por ser un área prioritaria; una alta proporción de pacientes en período post operatorio cursa con dolor, por lo tanto, la documentación debe ser útil para la toma de decisiones clínicas. Se implementó un programa de entrenamiento denominado “Manejo del Dolor” dirigido al personal de enfermería. Se utilizó la tecnología de la información como herramienta para fortalecer el conocimiento con base en la revisión sistemática de la literatura; el personal de enfermería participante seleccionó la mejor evidencia; posteriormente se trabajó en la transferencia de este conocimiento a la práctica a través del diseño de un protocolo para el manejo del dolor. Se concluye que el conocimiento del manejo del dolor es fundamental para que enfermería documente con mayor precisión sus intervenciones. PMID:24199106

  5. An integrated experimental and computational approach to laser surface nitriding of Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Dahotre, Sanket N.; Vora, Hitesh D.; Pavani, K.; Banerjee, Rajarshi

    2013-04-01

    Titanium and its alloys have been commonly used in many biological and industrial applications owing to their excellent mechanical and physical properties. However, they have been specifically inadequate for biomedical implants due to their inferior tribological properties (low wear resistance, higher coefficient of friction, and lower hardness). As a remedy, the process of laser nitriding has emerged from the past few decades as a unique method for tailoring the surface microstructures and/or composition of titanium for enhanced tribological characteristics of titanium and its alloys. In the present study, a multiphysics computational model was developed to predict the nitrogen diffusion length into the Ti-6Al-4V alloy under various laser processing conditions (laser power and scanning speed). XRD, SEM and EDS analyses were also conducted for phase identification, microstructural investigation, and estimating the nitrogen concentration, respectively. Both computational and experimental results indicated that the depth of nitrogen diffusion increased with decrease in scanning speed, and subsequent increase in laser interaction time and increase in input laser energy density.

  6. Highly efficient pseudomorphic InGaAs/GaAs/AlGaAs single quantum well lasers for monolithic integration

    NASA Technical Reports Server (NTRS)

    Larsson, A.; Cody, J.; Forouhar, S.; Lang, R. J.

    1990-01-01

    Highly efficient ridge waveguide pseudomorphic single quantum well lasers, emitting at 980 nm, have been fabricated from an In(0.2)Ga(0.8)As/GaAs/AlGaAs graded-index separate confinement heterostructure grown by molecular beam epitaxy. The laterial index guiding provided by the ridge reduces the anomalously large lateral loss of optical power found in gain-guided structures, thereby reducing the internal loss by more than 50 percent. The low threshold current (7.6 mA) and high differential quantum efficiency (79 percent) obtained under continuous operation as well as the transparency of the GaAs substrate to the emitted radiation render these lasers attractive for Ga-As-based optoelectronic integration.

  7. Laser Assisted Milling of Ti-6Al-4V ELI with the Analysis of Surface Integrity and its Economics

    NASA Astrophysics Data System (ADS)

    Hedberg, Gary K.; Shin, Yung C.

    2015-09-01

    This study presents the experimental evaluation of laser assisted milling (LAML) of Ti-6AL-4V ELI (Ti-64), which is used in the orthopedic industry, by using localized preheating of the workpiece via laser irradiation. Improvements to the machinability of this material with LAML are assessed while considering the surface integrity. Suitable laser heating conditions as well as machining conditions are determined based on temperature prediction modeling. Machinability improvements are shown in terms of tool wear, material removal rates and cutting force reduction. Systematic characterization of samples is shown to demonstrate that the machined sub-surfaces are not adversely affected during LAML by precisely controlling laser heating, via hardness measurements, scanning electron microscopy (SEM) for microstructure analysis, and X-ray diffraction (XRD) for residual stresses. An economic analysis shows that LAML provides the cost reduction over conventional machining.

  8. Optimization of an integrated electrodisinfection/electrocoagulation process with Al bipolar electrodes for urban wastewater reclamation.

    PubMed

    Cotillas, Salvador; Llanos, Javier; Cañizares, Pablo; Mateo, Sara; Rodrigo, Manuel A

    2013-04-01

    In this work, a novel integrated electrochemical process for urban wastewater regeneration is described. The electrochemical cell consists in a Boron Doped Diamond (BDD) or a Dimensionally Stable Anode (DSA) as anode, a Stainless Steel (SS) as cathode and a perforated aluminum plate, which behaves as bipolar electrode, between anode and cathode. Thus, in this cell, it is possible to carry out, at the same time, two different electrochemical processes: electrodisinfection (ED) and electrocoagulation (EC). The treatment of urban wastewater with different anodes and different operating conditions is studied. First of all, in order to check the process performance, experiments with synthetic wastewaters were carried out, showing that it is possible to achieve a 100% of turbidity removal by the electrodissolution of the bipolar electrode. Next, the effect of the current density and the anode material are studied during the ED-EC process of actual effluents. Results show that it is possible to remove Escherichia coli and turbidity simultaneously of an actual effluent from a WasteWater Treatment Facility (WWTF). The use of BDD anodes allows to remove the E. coli completely at an applied electric charge of 0.0077 A h dm(-3) when working with a current density of 6.65 A m(-2). On the other hand, with DSA anodes, the current density necessary to achieve the total removal of E. coli is higher (11.12 A m(-2)) than that required with BDD anodes. Finally, the influence of cell flow path and flow rate have been studied. Results show that the performance of the process strongly depends on the characteristics of the initial effluent (E. coli concentration and Cl(-)/NH(4)(+) initial ratio) and that a cell configuration cathode (inlet)-anode (outlet) and a higher flow rate enhance the removal of the turbidity from the treated effluent.

  9. Optimization of an integrated electrodisinfection/electrocoagulation process with Al bipolar electrodes for urban wastewater reclamation.

    PubMed

    Cotillas, Salvador; Llanos, Javier; Cañizares, Pablo; Mateo, Sara; Rodrigo, Manuel A

    2013-04-01

    In this work, a novel integrated electrochemical process for urban wastewater regeneration is described. The electrochemical cell consists in a Boron Doped Diamond (BDD) or a Dimensionally Stable Anode (DSA) as anode, a Stainless Steel (SS) as cathode and a perforated aluminum plate, which behaves as bipolar electrode, between anode and cathode. Thus, in this cell, it is possible to carry out, at the same time, two different electrochemical processes: electrodisinfection (ED) and electrocoagulation (EC). The treatment of urban wastewater with different anodes and different operating conditions is studied. First of all, in order to check the process performance, experiments with synthetic wastewaters were carried out, showing that it is possible to achieve a 100% of turbidity removal by the electrodissolution of the bipolar electrode. Next, the effect of the current density and the anode material are studied during the ED-EC process of actual effluents. Results show that it is possible to remove Escherichia coli and turbidity simultaneously of an actual effluent from a WasteWater Treatment Facility (WWTF). The use of BDD anodes allows to remove the E. coli completely at an applied electric charge of 0.0077 A h dm(-3) when working with a current density of 6.65 A m(-2). On the other hand, with DSA anodes, the current density necessary to achieve the total removal of E. coli is higher (11.12 A m(-2)) than that required with BDD anodes. Finally, the influence of cell flow path and flow rate have been studied. Results show that the performance of the process strongly depends on the characteristics of the initial effluent (E. coli concentration and Cl(-)/NH(4)(+) initial ratio) and that a cell configuration cathode (inlet)-anode (outlet) and a higher flow rate enhance the removal of the turbidity from the treated effluent. PMID:23351433

  10. High-performance GaAs/AlGaAs optical phase modulators for microwave/photonic integrated circuits

    SciTech Connect

    Hietala, V.M.; Kravitz, S.H.; Armendariz, M.G.; Vawter, G.A.; Carson, R.F.; Leibenguth, R.E.

    1993-12-31

    High-speed high-performance optical phase modulators are being developed for use in a coherent Photonic Integrated Circuit (PIC) technology. These phase modulators are the critical component of a PIC program at Sandia National Laboratories targeted for microwave/millimeter-wave signal processing and control including phased-array antenna control. The primary design goals for these modulators are amenability for integration into PICs, high ``figure of merit`` (FOM -- phase shift per unit length-voltage), and large bandwidths allowing for operation at millimeter wave frequencies. Depletion-edge-translation optical phase modulators (GaAs/AlGaAs based) have been selected as the device technology of choice due to their high FOM (>60{degree}/V{center_dot}mm @ 1.3 {mu}m). These modulators unfortunately suffer from a large terminal capacitance which greatly limits speed. To overcome this problem, a distributed electrode design based on the use of slow-wave coplanar strips has been developed. Device design and measurements are presented in this paper.

  11. Improved high temperature integration of Al2O3 on MoS2 by using a metal oxide buffer layer

    NASA Astrophysics Data System (ADS)

    Son, Seokki; Yu, Sunmoon; Choi, Moonseok; Kim, Dohyung; Choi, Changhwan

    2015-01-01

    We deposited a metal oxide buffer layer before atomic layer deposition (ALD) of Al2O3 onto exfoliated molybdenum disulfide (MoS2) in order to accomplish enhanced integration. We demonstrate that even at a high temperature, functionalization of MoS2 by means of a metal oxide buffer layer can effectively provide nucleation sites for ALD precursors, enabling much better surface coverage of Al2O3. It is shown that using a metal oxide buffer layer not only allows high temperature ALD process, resulting in highly improved quality of Al2O3/MoS2 interface, but also leaves MoS2 intact.

  12. Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS (Lawrence Berkeley Laboratory Advanced Light Source) Booster Dipole Magnets

    SciTech Connect

    Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.

    1989-03-01

    A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs.

  13. Investigating chlorophyll and nitrogen levels of mangroves at Al-Khor, Qatar: an integrated chemical analysis and remote sensing approach.

    PubMed

    Al-Naimi, Noora; Al-Ghouti, Mohammad A; Balakrishnan, Perumal

    2016-05-01

    Mangroves are unique ecosystems that dominate tropical and subtropical coastlines around the world. They provide shelter and nursery to wide variety of species such as fish and birds. Around 73 species of mangroves were recognized around the world. In Qatar, there is only one mangrove species Avicennia marina that is predominant along the northeastern coast. Assessing the health of these valuable ecosystems is vital for protection, management, and conservation of those resources. In this study, an integrated approach of chemical and remote sensing analysis was implemented to investigate the current status of the mangrove trees in Al-Khor, Qatar. Fifteen different A. marina trees from different locations in the mangrove forest were examined for their chlorophyll and nitrogen content levels. Soil analysis was also conducted to understand the effect of moisture on nitrogen availability. Results shows that currently, mangroves are in a good status in terms of nitrogen availability and chlorophyll levels which are related and both are key factors for photosynthesis. Remote sensing techniques were used for chlorophyll prediction. The results showed that these methods have the potential to be used for chlorophyll prediction and estimation. PMID:27048493

  14. Investigating chlorophyll and nitrogen levels of mangroves at Al-Khor, Qatar: an integrated chemical analysis and remote sensing approach.

    PubMed

    Al-Naimi, Noora; Al-Ghouti, Mohammad A; Balakrishnan, Perumal

    2016-05-01

    Mangroves are unique ecosystems that dominate tropical and subtropical coastlines around the world. They provide shelter and nursery to wide variety of species such as fish and birds. Around 73 species of mangroves were recognized around the world. In Qatar, there is only one mangrove species Avicennia marina that is predominant along the northeastern coast. Assessing the health of these valuable ecosystems is vital for protection, management, and conservation of those resources. In this study, an integrated approach of chemical and remote sensing analysis was implemented to investigate the current status of the mangrove trees in Al-Khor, Qatar. Fifteen different A. marina trees from different locations in the mangrove forest were examined for their chlorophyll and nitrogen content levels. Soil analysis was also conducted to understand the effect of moisture on nitrogen availability. Results shows that currently, mangroves are in a good status in terms of nitrogen availability and chlorophyll levels which are related and both are key factors for photosynthesis. Remote sensing techniques were used for chlorophyll prediction. The results showed that these methods have the potential to be used for chlorophyll prediction and estimation.

  15. Narrow linewidth laterally coupled 1.55 μm AlGaInAs/InP distributed feedback lasers integrated with a curved tapered semiconductor optical amplifier.

    PubMed

    Hou, Lianping; Haji, Mohsin; Akbar, Jehan; Marsh, John H

    2012-11-01

    We present a laterally coupled 1.55 μm AlGaInAs/InP distributed feedback laser monolithically integrated with a curved tapered optical amplifier, providing an output power of 210 mW with single transverse and longitudinal mode operation exhibiting a record low linewidth of 64 kHz. PMID:23114351

  16. Direct optical injection locking of monolithically integrated In(0.53)Ga(0.47)As/In(0.52)Al(0.48)As MODFET oscillators

    NASA Astrophysics Data System (ADS)

    Yang, D.; Bhattacharya, P. K.; Brock, T.

    1993-05-01

    The authors have fabricated monolithically integrated In(0.53)Ga(0.47)As/In(0.52)Al(0.48)As 0.25-micron gate MODFET oscillators. The results of direct optical subharmonic injection locking of these oscillator circuits at 10.159 and 19.033 GHz are presented.

  17. Heterogeneous integration of epitaxial Ge on Si using AlAs/GaAs buffer architecture: suitability for low-power fin field-effect transistors.

    PubMed

    Hudait, Mantu K; Clavel, Michael; Goley, Patrick; Jain, Nikhil; Zhu, Yan

    2014-01-01

    Germanium-based materials and device architectures have recently appeared as exciting material systems for future low-power nanoscale transistors and photonic devices. Heterogeneous integration of germanium (Ge)-based materials on silicon (Si) using large bandgap buffer architectures could enable the monolithic integration of electronics and photonics. In this paper, we report on the heterogeneous integration of device-quality epitaxial Ge on Si using composite AlAs/GaAs large bandgap buffer, grown by molecular beam epitaxy that is suitable for fabricating low-power fin field-effect transistors required for continuing transistor miniaturization. The superior structural quality of the integrated Ge on Si using AlAs/GaAs was demonstrated using high-resolution x-ray diffraction analysis. High-resolution transmission electron microscopy confirmed relaxed Ge with high crystalline quality and a sharp Ge/AlAs heterointerface. X-ray photoelectron spectroscopy demonstrated a large valence band offset at the Ge/AlAs interface, as compared to Ge/GaAs heterostructure, which is a prerequisite for superior carrier confinement. The temperature-dependent electrical transport properties of the n-type Ge layer demonstrated a Hall mobility of 370 cm(2)/Vs at 290 K and 457 cm(2)/Vs at 90 K, which suggests epitaxial Ge grown on Si using an AlAs/GaAs buffer architecture would be a promising candidate for next-generation high-performance and energy-efficient fin field-effect transistor applications.

  18. Integrated micro-optical multichip module based on an uncooled InGaAsSb/AlGaAsSb photodetector

    NASA Astrophysics Data System (ADS)

    Lohokare, Saurabh K.; Sulima, Oleg V.; Dillon, Thomas E.; Prather, Dennis W.

    2005-09-01

    This paper focuses on the integration of InGaAsSb photodetectors along with micro-optics in order to realize a prototype system that can achieve a stronger response during atmospheric profiling and spectroscopy measurements. The integration of the detector was executed using a novel conductive-adhesive-based flip-chip integration process. The design, fabrication, and integration of the constituent technologies and experimental results from their characterization are presented.

  19. Improved high temperature integration of Al{sub 2}O{sub 3} on MoS{sub 2} by using a metal oxide buffer layer

    SciTech Connect

    Son, Seokki; Choi, Moonseok; Kim, Dohyung; Choi, Changhwan; Yu, Sunmoon

    2015-01-12

    We deposited a metal oxide buffer layer before atomic layer deposition (ALD) of Al{sub 2}O{sub 3} onto exfoliated molybdenum disulfide (MoS{sub 2}) in order to accomplish enhanced integration. We demonstrate that even at a high temperature, functionalization of MoS{sub 2} by means of a metal oxide buffer layer can effectively provide nucleation sites for ALD precursors, enabling much better surface coverage of Al{sub 2}O{sub 3}. It is shown that using a metal oxide buffer layer not only allows high temperature ALD process, resulting in highly improved quality of Al{sub 2}O{sub 3}/MoS{sub 2} interface, but also leaves MoS{sub 2} intact.

  20. Selective epitaxial growth of monolithically integrated GaN-based light emitting diodes with AlGaN/GaN driving transistors

    SciTech Connect

    Liu, Zhaojun; Ma, Jun; Huang, Tongde; Liu, Chao; May Lau, Kei

    2014-03-03

    In this Letter, we report selective epitaxial growth of monolithically integrated GaN-based light emitting diodes (LEDs) with AlGaN/GaN high-electron-mobility transistor (HEMT) drivers. A comparison of two integration schemes, selective epitaxial removal (SER), and selective epitaxial growth (SEG) was made. We found the SER resulted in serious degradation of the underlying LEDs in a HEMT-on-LED structure due to damage of the p-GaN surface. The problem was circumvented using the SEG that avoided plasma etching and minimized device degradation. The integrated HEMT-LEDs by SEG exhibited comparable characteristics as unintegrated devices and emitted modulated blue light by gate biasing.

  1. High-performance GaAs/AlGaAs optical phase modulators for microwave photonic integrated circuits

    SciTech Connect

    Hietala, V.M.; Kravitz, S.H.; Armendariz, M.G.; Vawter, G.A.; Carson, R.F.

    1994-03-01

    A high-performance high-speed optical phase modulator for photonic integrated circuit (PIC) use is described. Integration of these optical phase modulators into a real system (compass) is also discussed. The optical phase modulators are based on depletion-edge translation and have experimentally provided optical phase shifts in excess of 60{degrees}/V{center_dot}mm with approximately 4 dB/cm loss while simultaneously demonstrating bandwidths in excess of 10 GHz.

  2. High-κ Al{sub 2}O{sub 3} material in low temperature wafer-level bonding for 3D integration application

    SciTech Connect

    Fan, J. Tu, L. C.; Tan, C. S.

    2014-03-15

    This work systematically investigated a high-κ Al{sub 2}O{sub 3} material for low temperature wafer-level bonding for potential applications in 3D microsystems. A clean Si wafer with an Al{sub 2}O{sub 3} layer thickness of 50 nm was applied as our experimental approach. Bonding was initiated in a clean room ambient after surface activation, followed by annealing under inert ambient conditions at 300 °C for 3 h. The investigation consisted of three parts: a mechanical support study using the four-point bending method, hermeticity measurements using the helium bomb test, and thermal conductivity analysis for potential heterogeneous bonding. Compared with samples bonded using a conventional oxide bonding material (SiO{sub 2}), a higher interfacial adhesion energy (∼11.93 J/m{sup 2}) and a lower helium leak rate (∼6.84 × 10{sup −10} atm.cm{sup 3}/sec) were detected for samples bonded using Al{sub 2}O{sub 3}. More importantly, due to the excellent thermal conductivity performance of Al{sub 2}O{sub 3}, this technology can be used in heterogeneous direct bonding, which has potential applications for enhancing the performance of Si photonic integrated devices.

  3. Theoretical analysis and experiment of subwavelength structure-integrated red AlGaInP light-emitting diodes for uniform field distribution and enhanced light extraction efficiency

    NASA Astrophysics Data System (ADS)

    Lee, Gil Ju; Song, Young Min

    2016-03-01

    We report theoretical and experimental analysis of antireflective subwavelength structures (SWSs) on GaP substrates to enhance the light output with a uniform light distribution of AlGaInP-based red light-emitting diodes (LEDs). Scaling issues on the optical performance are analyzed by the calculation results from finite-difference time-domain (FDTD) and rigorous coupled-wave analysis (RCWA) methods. The optical simulation reveals that SWSs with a period of 100-150 nm achieve highest optical output power, while maintaining a uniform light field distribution, in the subwavelength regime. To validate our theoretical results, disordered SWSs with a tapered shape were fabricated on a GaP layer of AlGaInP red LEDs by lithography-free dry etching of Ag nanoparticles. The SWS-integrated LED shows a uniform light output distribution with an improved light output power compared with the conventional LED.

  4. Etologia aplicada al manejo de especies amenazadas: el caso del turon de patas negras (Mustela nigripes)

    USGS Publications Warehouse

    Vargas, A.; Biggins, D.; Miller, B.

    1999-01-01

    de esta especie de un modo más eficaz y rentable. Black-footed ferrets are considered one of the world's most endangered mammals. The last wild population was discovered in 1981 in Meteetsee, Wyoming, and, in 1985 it collapsed due to an epizootic of canine distemper in combination with sylvatic plague. Prior to the extinction of the last remnant population, 18 wild black-footed ferrets were captured to initiate captive propagation efforts. Captive breeding has been successful and, during the last 11 years, more than 2600 black-footed ferrets have been born in captive breeding centers. Since 1991, approximately 870 ferrets have been reintroduced in 5 areas located within the ferret's original geographic distribution, including sites in Wyoming, Montana, South Dakota, and Arizona. Scientific research has been, and continues to be, a critical tool to direct recovery efforts. Studies in applied ethology conducted on captive and reintroduced ferret populations have demonstrated that a naturalistic captive environment, particularly during early developmental periods, enhances the expression of behaviors necessary for survival in nature. Ferrets raised in a naturalistic environment develop better predatory skills, are able to recognize prairie dog burrows as a home and shelter from predators, and are more physically fit. Results from these studies have been adapted into management strategies to help implement a more cost-effective road to black-footed ferret recovery.

  5. Levels of analysis in neuroscientific studies of emotion: Comment on "The quartet theory of human emotions: an integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Kuiken, Don; Douglas, Shawn

    2015-06-01

    In the conduct of neuroscience research, methodological choices and theoretical claims often reveal underlying metamethodological and ontological commitments. Koelsch et al. [1] accentuate such commitments in their description of four "neuroanatomically distinct systems," each the substrate of "a specific class of affects" (p. 1). Explication of those classes of affect require theoretical integration across methodologically diverse disciplines, including "psychology, neurobiology, sociology, anthropology, and psycholinguistics" (p. 3). (Philosophy is noticeably missing from this list, but several aspects of the authors' stance indicate that it is not ignored.)

  6. A hybrid electron cyclotron resonance metal ion source with integrated sputter magnetron for the production of an intense Al+ ion beam

    NASA Astrophysics Data System (ADS)

    Weichsel, T.; Hartung, U.; Kopte, T.; Zschornack, G.; Kreller, M.; Philipp, A.

    2015-09-01

    A metal ion source prototype has been developed: a combination of magnetron sputter technology with 2.45 GHz electron cyclotron resonance (ECR) ion source technology—a so called magnetron ECR ion source (MECRIS). An integrated ring-shaped sputter magnetron with an Al target is acting as a powerful metal atom supply in order to produce an intense current of singly charged metal ions. Preliminary experiments show that an Al+ ion current with a density of 167 μA/cm2 is extracted from the source at an acceleration voltage of 27 kV. Spatially resolved double Langmuir probe measurements and optical emission spectroscopy were used to study the plasma states of the ion source: sputter magnetron, ECR, and MECRIS plasma. Electron density and temperature as well as Al atom density were determined as a function of microwave and sputter magnetron power. The effect of ECR heating is strongly pronounced in the center of the source. There the electron density is increased by one order of magnitude from 6 × 109 cm-3 to 6 × 1010 cm-3 and the electron temperature is enhanced from about 5 eV to 12 eV, when the ECR plasma is ignited to the magnetron plasma. Operating the magnetron at constant power, it was observed that its discharge current is raised from 1.8 A to 4.8 A, when the ECR discharge was superimposed with a microwave power of 2 kW. At the same time, the discharge voltage decreased from about 560 V to 210 V, clearly indicating a higher plasma density of the MECRIS mode. The optical emission spectrum of the MECRIS plasma is dominated by lines of excited Al atoms and shows a significant contribution of lines arising from singly ionized Al. Plasma emission photography with a CCD camera was used to prove probe measurements and to identify separated plasma emission zones originating from the ECR and magnetron discharge.

  7. TTP AL921102: An integrated geophysics program for non-intrusive characterization of mixed-Waste landfill sites. Final report

    SciTech Connect

    Hasbrouck, J.C.

    1993-09-01

    This Technical Task conducted for the US Department of Energy Office of Technology Development demonstrates the effectiveness of integrating several surface geophysical techniques to nonintrusively characterize mixed-waste landfill sites. An integrated approach enables an area to be characterized faster and cheaper because repeated access is not necessary and offers data and interpretations not attainable by a single technique. Field demonstrations using the complex galvanic resistivity, spontaneous potential (SP), ground-penetrating radar (GPR), time-domain electromagnetic (TDEM), shear-wave (S-wave) seismic and compressional-wave (P-wave) seismic geophysical techniques were conducted at the Mixed-Waste Landfill Integrated Demonstration (MWLID) test site at the Sandia National Laboratories/New Mexico in Albuquerque. Data were acquired in two areas that have both known and unknown attributes. Although data from numerous profiles were analyzed, three lines were chosen as representative of the landfill site: Line 20E that crosses both the known Chromic Acid and Organics Pits, Line 60E that transectes an essentially barren area, and Line 125E located in an area with unknown subsurface conditions.

  8. Monolithically integrated enhancement/depletion-mode AlGaN/GaN HEMTs SRAM unit and voltage level shifter using fluorine plasma treatment

    NASA Astrophysics Data System (ADS)

    Yonghe, Chen; Xuefeng, Zheng; Jincheng, Zhang; Xiaohua, Ma; Yue, Hao

    2016-05-01

    A GaN-based E/D mode direct-couple logic 6 transistors SRAM unit and a voltage level shifter were designed and fabricated. E-mode and D-mode AlGaN/GaN HEMTs were integrated in one wafer using fluorine plasma treatment and using a moderate AlGaN barrier layer heterojunction structure. The 6 transistors SRAM unit consists of two symmetrical E/D mode inverters and two E-mode switch HEMTs. The output low and high voltage of the SRAM unit are 0.95 and 0.07 V at a voltage supply of 1 V. The voltage level shifter lowers the supply voltage using four Ni-AlGaN Schottky diodes in a series at a positive supply voltage of 6 V and a negative supply voltage of -6 V. By controlling the states of inverter modules of the level shifter in turn, the level shifter offers two channel voltage outputs of -0.5 and -5 V. The flip voltage of the level shifter is 0.76 V. Both the SRAM unit and voltage shifter operate correctly, demonstrating the promising potential for GaN-based E/D mode digital and analog integrated circuits. Several considerations are proposed to avoid the influence of threshold voltage degradation of D-mode and E-mode HEMT on the operation of the circuit. Project supported by the National Natural Science Foundation of China (No. 61334002), the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory (No. ZHD201206), and the Program for New Century Excellent Talents in University (No. NCET-12-0915).

  9. Ion implantation: surface treatment for improving the bone integration of titanium and Ti6Al4V dental implants.

    PubMed

    De Maeztu, Miguel A; Alava, J Iñaki; Gay-Escoda, Cosme

    2003-02-01

    Dental implants subjected to surface treatment have shown better bone integration than implants which have only been turned (machined). Three main types of treatment are presently available: the addition of material or coating, the removal of material, and surface modification. Ion implantation corresponds to the third approach. A histomorphometric study is made following the rabbit tibial bone placement of 88 commercial dental implants of pure titanium and Ti6AI4V subjected to surface treatment in the form of different ion implants (C+, CO+, N+, Ne+). Light microscopic, scanning electron microscopic (SEM), electron microsonde (EDS) and X-ray photoelectron spectroscopy (XPS) studies were made. The results indicate improved bone integration (expressed as percentage bone-implant contact) in those specimens subjected to ion implantation versus the non-treated controls, the difference being statistically significant for the groups treated with C+ and CO+. In these groups, XPS showed a Ti-O-C junction (bone-implant interface) involving covalent type bonds, these being stronger and more stable than the ion-type bonds usually established between the titanium oxide and bone.

  10. Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

    SciTech Connect

    Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

    2015-05-04

    We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

  11. Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

    2015-05-01

    We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

  12. A hybrid electron cyclotron resonance metal ion source with integrated sputter magnetron for the production of an intense Al{sup +} ion beam

    SciTech Connect

    Weichsel, T. Hartung, U.; Kopte, T.; Zschornack, G.; Kreller, M.; Philipp, A.

    2015-09-15

    A metal ion source prototype has been developed: a combination of magnetron sputter technology with 2.45 GHz electron cyclotron resonance (ECR) ion source technology—a so called magnetron ECR ion source (MECRIS). An integrated ring-shaped sputter magnetron with an Al target is acting as a powerful metal atom supply in order to produce an intense current of singly charged metal ions. Preliminary experiments show that an Al{sup +} ion current with a density of 167 μA/cm{sup 2} is extracted from the source at an acceleration voltage of 27 kV. Spatially resolved double Langmuir probe measurements and optical emission spectroscopy were used to study the plasma states of the ion source: sputter magnetron, ECR, and MECRIS plasma. Electron density and temperature as well as Al atom density were determined as a function of microwave and sputter magnetron power. The effect of ECR heating is strongly pronounced in the center of the source. There the electron density is increased by one order of magnitude from 6 × 10{sup 9} cm{sup −3} to 6 × 10{sup 10} cm{sup −3} and the electron temperature is enhanced from about 5 eV to 12 eV, when the ECR plasma is ignited to the magnetron plasma. Operating the magnetron at constant power, it was observed that its discharge current is raised from 1.8 A to 4.8 A, when the ECR discharge was superimposed with a microwave power of 2 kW. At the same time, the discharge voltage decreased from about 560 V to 210 V, clearly indicating a higher plasma density of the MECRIS mode. The optical emission spectrum of the MECRIS plasma is dominated by lines of excited Al atoms and shows a significant contribution of lines arising from singly ionized Al. Plasma emission photography with a CCD camera was used to prove probe measurements and to identify separated plasma emission zones originating from the ECR and magnetron discharge.

  13. Effect of Al2O3 insulator thickness on the structural integrity of amorphous indium-gallium-zinc-oxide based thin film transistors.

    PubMed

    Kim, Hak-Jun; Hwang, In-Ju; Kim, Youn-Jea

    2014-12-01

    The current transparent oxide semiconductors (TOSs) technology provides flexibility and high performance. In this study, multi-stack nano-layers of TOSs were designed for three-dimensional analysis of amorphous indium-gallium-zinc-oxide (a-IGZO) based thin film transistors (TFTs). In particular, the effects of torsional and compressive stresses on the nano-sized active layers such as the a-IGZO layer were investigated. Numerical simulations were carried out to investigate the structural integrity of a-IGZO based TFTs with three different thicknesses of the aluminum oxide (Al2O3) insulator (δ = 10, 20, and 30 nm), respectively, using a commercial code, COMSOL Multiphysics. The results are graphically depicted for operating conditions. PMID:25971080

  14. AlGaAs/GaAs p-i-n photodiode/preamplifier monolithic photoreceiver integrated on a semi-insulating GaAs substrate

    NASA Astrophysics Data System (ADS)

    Wada, O.; Hamaguchi, H.; Miura, S.; Makiuchi, M.; Nakai, K.; Horimatsu, H.; Sakurai, T.

    1985-05-01

    A fully monolithic photoreceiver circuit incorporating an AlGaAs/GaAs p-i-n photodiode and a GaAs field-effect transistor based transimpedance amplifier has been fabricated in the form of a horizontally integrated structure on a semi-insulating GaAs substrate. Parasitic capacitances of the circuit elements have been minimized in the present monolithic circuit, and a short rise and fall time of 1.0 ns, corresponding to an approximate -3 dB frequency of 300 MHz, has been demonstrated at the internal feedback resistance of 1.3 kΩ. Preliminary measurement of the noise characteristics of the present circuit has exhibited an encouraging value of the equivalent input noise current of 13 pA Hz-1/2 at 300 MHz.

  15. High-power AlGaAs/GaAs single quantum well surface-emitting lasers with integrated 45° beam deflectors

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hoon; Lang, Robert J.; Larsson, Anders; Lee, Luke P.; Narayanan, Authi A.

    1990-11-01

    We report on high-power AlGaAs/GaAs graded-index single quantum well surface-emitting lasers (SELs), with etched vertical mirrors and integrated 45° beam deflectors fabricated by a tilted ion beam etching technique. 100-μm-wide, 500-μm-long, broad-area SELs exhibited a threshold current of 300 mA, a peak power of more than 380 mW, and an external differential quantum efficiency of 17% without facet coating. The SELs showed stable operation up to 7th. These results show the highest power and external differential quantum efficiency reported to date for 45° beam deflecting SELs. The full widths at half maximum of the surface-emitting far-field pattern parallel and perpendicular to the laser axis were 8.5° and 14°, respectively.

  16. Integrated experimental and theoretical approach for corrosion and wear evaluation of laser surface nitrided, Ti-6Al-4V biomaterial in physiological solution.

    PubMed

    Vora, Hitesh D; Shanker Rajamure, Ravi; Dahotre, Sanket N; Ho, Yee-Hsien; Banerjee, Rajarshi; Dahotre, Narendra B

    2014-09-01

    A laser based surface nitriding process was adopted to further enhance the osseo-integration, corrosion resistance, and tribological properties of the commonly used bioimplant alloy, Ti-6Al-4V. Earlier preliminary osteoblast, electrochemical, and corrosive wear studies of laser nitrided titanium in simulated body fluid clearly revealed improvement of cell adhesion as well as enhancement in corrosion and wear resistance but mostly lacked the in-depth fundamental understanding behind these improvements. Therefore, a novel integrated experimental and theoretical approach were implemented to understand the physical phenomena behind the improvements and establish the property-structure-processing correlation of nitrided surface. The first principle and thermodynamic calculations were employed to understand the thermodynamic, electronic, and elastic properties of TiN for enthalpy of formation, Gibbs free energy, density of states, and elastic properties of TiN were investigated. Additionally, open circuit potential and cyclic potentio-dynamic polarization tests were carried out in simulated body fluid to evaluate the corrosion resistance that in turn linked with the experimentally measured and computationally predicted surface energies of TiN. From these results, it is concluded that the enhancement in the corrosion resistance after laser nitriding is mainly attributed to the presence of covalent bonding via hybridization among Ti (p) and N (d) orbitals. Furthermore, mechanical properties, such as, Poisson׳s ratio, stiffness, Pugh׳s ductility criteria, and Vicker׳s hardness, predicted from first principle calculations were also correlated to the increase in wear resistance of TiN. All the above factors together seem to have contributed to significant improvement in both wear and corrosion performance of nitride surface compared to the bare Ti-6Al-4V in physiological environment indicating its suitability for bioimplant applications.

  17. Novel integration of ultrathin Al2O3 with low-k dielectric as bilayer liner for capacitance optimization and stress mitigation in Cu through-silicon-via

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Li, Hong Yu; Shang, Yang; Yoo, Woosik; Yu, Hao; Tan, Chuan Seng

    2016-04-01

    Through-silicon-via (TSV) used in three-dimensional (3D) stacked dies must present small electrical parasitic, such as capacitance, to allow for low latency signal transmission. Stable TSV capacitance is desired to overcome the spatial circuit performance variation caused by non-uniform hot-spot heating. In this work, a novel combination of low-k with ultrathin Al2O3 bilayer liner is successfully integrated in the TSV. The TSV capacitance is reduced by ˜26% as compared to plasma-enhanced tetrahydrothosilicate (PETEOS) oxide liner. Stable TSV capacitance within the operating voltage of interest (˜0-5 V) is achieved by operating the TSV in a stable accumulation capacitance region. The positive shift in the flat-band voltage (ΔV FB = +19 V) is achieved by utilizing Al2O3-induced negative fixed charge (|Q f| = 1.3 × 1012 cm-2) at the Si/low-k interface. Leakage current density of the bilayer liner is improved to a level comparable with the PETEOS oxide liner post annealing [forming gas (N2/H2) at 350 °C for 2 h or 400 °C for 0.5 h]. Low-k material with a smaller elastic modulus improves the thermo-mechanical stress exerted on the surrounding Si substrate compared with PETEOS oxide.

  18. Band edge tailoring of InGaAs/AlAsSb coupled double quantum wells for a monolithically integrated all-optical switch.

    PubMed

    Feng, Jijun; Akimoto, Ryoichi; Gozu, Shin-ichiro; Mozume, Teruo; Hasama, Toshifumi; Ishikawa, Hiroshi

    2013-07-01

    We demonstrate a compact all-optical Michelson interferometer (MI) gating switch with monolithic integration of two different bandgap energies. Based on the ion-induced intermixing in InGaAs/AlAsSb coupled double quantum wells, the blueshift of the band edge can be tailored. Through phosphorus ion implantation with a dose of 5 × 10(14) cm(-2) and subsequent annealing at 720 °C for 60 s, an implanted sample can acquire a high transmittance compared with the as-grown one. Meanwhile, the cross-phase modulation (XPM) efficiency of a non-implanted sample undergoing the same annealing process decreases little. An implanted part for signal propagation and a non-implanted section for XPM are thus monolithically integrated for an MI switch by an area-selective manner. Full switching of a π-rad nonlinear phase shift is achieved with pump pulse energy of 5.6 pJ at a 10-GHz repetition rate.

  19. New approach for high-peak power lasing based on epitaxially integrated AlGaAs/GaAs laser-thyristor heterostructure

    NASA Astrophysics Data System (ADS)

    Slipchenko, Sergey; Podoskin, Alexsandr; Rozhkov, Alexsandr; Pikhtin, Nikita; Tarasov, Il`ya; Bagaev, Timur; Ladugin, Maxim; Marmalyuk, Alexsandr; Padalitsa, Anatolii; Simakov, Vladimir

    2015-03-01

    A new approach to generation of high optical peak power by epitaxially and functionally integrated high-speed highpower current switch and laser heterostructure (so-called laser-thyristor) has been developed. This approach makes it possible to reduce the loss in external electrical connections, which is particularly important for the short-pulse highamplitude current pumping. In addition, it considerably simplifies the fabrication technology of pulsed laser sources as a commercial product and allows stacking of multiple-element systems. The epitaxially integrated AlGaAs/GaAs heterostructure of low-voltage laser-thyristor has been studied and optimized for generation of high-power pulses at a 900-nm wavelength. It is shown that the incomplete switch-on of the laserthyristor in the initial stage and the nonlinear dynamics of the emitted laser power are due to the insufficient efficiency of the vertical optical feedback in the epitaxially integrated heterostructure. Optimization of the composition and the interband absorption spectra of transistor base layers makes it possible to substantially raise the efficiency of control signals due to the rise in the photogeneration speed. Experimental laser-thyristor samples with a 200-μm aperture have been fabricated and studied. The maximum static blocking voltage does not exceed 20 V. It is shown that the generated laser pulses have a perfect bell-like shape without any indications of a nonlinear dynamics. This confirms that the changes introduced into the heterostructure design provide a sufficient efficiency of photogeneration of the control signal. As a result, the maximum optical peak power reaches 40 and 8 W at FWHM pulse durations of 95 and 13 ns, respectively. An analysis of the potential dynamics has shown that the heterostructure provides pumping of the active layer with up to 90-A pulses.

  20. [Cognitive behavioral treatment in the integral management of obesity in adolescents].

    PubMed

    Rodríguez-Morán, Martha; Mendoza-Ávila, Eduardo; Cumplido-Fuentes, Agustín; Simental-Mendía, Luis E; Rodríguez-Ramírez, Gabriela; Sánchez-Lazcano, Gloria Janeth; Ramírez-Bonilla, Paulina; Cumplido-González, Guadalupe; Ortiz-Martínez, Guadalupe; Pinedo-Rodríguez, Gustavo Alan; Meza-Villa, Ángel; Ortiz-Ramos, Alma Fátima; Puerta-Mota, Gerardo; Guerrero-Romero, Fernando

    2014-01-01

    INTRODUCTIÓN: la obesidad en niños y adolescentes y la morbilidad que se le asocia se han incrementado significativamente, lo cual se ha convertido en un problema de salud pública. El objetivo de este estudio fue evaluar la eficacia de la terapia cognitivo-conductual (TCC) en el manejo integral de la obesidad en adolescentes. MÉTODOS: estudio de intervención, aleatorio, doble ciego, controlado, de cuatro meses de seguimiento, al que se integraron 115 adolescentes obesos de 12 a 16 años de edad. El grupo de intervención recibió TCC como terapia coadyuvante, así como indicaciones de dieta y apoyo para el desarrollo de ejercicio. El grupo control solo recibió indicaciones de dieta y apoyo para el desarrollo de ejercicio.

  1. A Constitutive Equation Relating Composition and Microstructure to Properties in Ti-6Al-4V: As Derived Using a Novel Integrated Computational Approach

    NASA Astrophysics Data System (ADS)

    Ghamarian, Iman; Samimi, Peyman; Dixit, Vikas; Collins, Peter C.

    2015-11-01

    While it is useful to predict properties in metallic materials based upon the composition and microstructure, the complexity of real, multi-component, and multi-phase engineering alloys presents difficulties when attempting to determine constituent-based phenomenological equations. This paper applies an approach based upon the integration of three separate modeling approaches, specifically artificial neural networks, genetic algorithms, and Monte Carlo simulations to determine a mechanism-based equation for the yield strength of α+ β processed Ti-6Al-4V (all compositions in weight percent) which consists of a complex multi-phase microstructure with varying spatial and morphological distributions of the key microstructural features. Notably, this is an industrially important alloy yet an alloy for which such an equation does not exist in the published literature. The equation ultimately derived in this work not only can accurately describe the properties of the current dataset but also is consistent with the limited and dissociated information available in the literature regarding certain parameters such as intrinsic yield strength of pure hexagonal close-packed alpha titanium. In addition, this equation suggests new interesting opportunities for controlling yield strength by controlling the relative intrinsic strengths of the two phases through solid solution strengthening.

  2. ALS Association

    MedlinePlus

    ... toward a world without ALS! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National ALS Registry The National ALS Registry is a congressionally ...

  3. Integration of robotics and neuroscience beyond the hand: What kind of synergies?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    d'Avella, Andrea

    2016-07-01

    Santello et al. [1] review an impressive amount of work on the control of biological and artificial hands that demonstrates how the concept of synergies can lead to a successful integration of robotics and neuroscience. Is it possible to generalize the same approach to the control of biological and artificial limbs and bodies beyond the hand? The human hand synergies that appear most relevant for robotic hands are those defined at the kinematic level, i.e. postural synergies [2]. Postural synergies capture the geometric relations among the many joints of the hand and allow for a low dimensional characterization and synthesis of the static hand postures involved in grasping and manipulating a large set of objects. However, many other complex motor skills such as walking, reaching, throwing, and catching require controlling multi-articular time-varying trajectories rather than static postures. Dynamic control of biological and artificial limbs and bodies, especially when geometric and inertial parameters are uncertain and the joints are compliant, poses great challenges. What kind of synergies might simplify the dynamic control of motor skills involving upper and lower limbs as well as the whole body?

  4. Optimization of a Common Buffer Platform for Monolithic Integration of InGaN/GaN Light-Emitting Diodes and AlGaN/GaN High-Electron-Mobility Transistors

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Cai, Yuefei; Jiang, Huaxing; Lau, Kei May

    2016-04-01

    For the development of a metal-interconnection-free integration scheme for monolithic integration of InGaN/GaN light-emitting diodes (LEDs) and AlGaN/GaN high-electron-mobility transistors (HEMTs), a common buffer to achieve high brightness, low leakage current, and high breakdown in the integrated HEMT-LED device is essential. Different buffer structures have been investigated, and their impacts upon both the LED and HEMT parts of the HEMT-LED device have been analyzed. Results indicated that a GaN/AlN buffer structure is the most ideal to serve as a common buffer platform, offering both the excellent crystalline quality and superior buffer resistivity required by the HEMT-LED device. Growth of the AlN layer was particularly crucial for engineering the dislocation density, surface morphology, as well as resistivity of the buffer layer. Using the optimized GaN/AlN buffer structure, the LED part of the HEMT-LED device was improved, showing greatly enhanced light output power and suppressed reverse leakage current, while the breakdown characteristics of the HEMT part were also improved.

  5. GIS-based vulnerability assessment to sea level rise of Al Hoceima Bay (Moroccan Mediterranean): towards an integrated coastal zone management (ICZM)

    NASA Astrophysics Data System (ADS)

    Khouakhi, A.; Snoussi, M.

    2013-12-01

    In the context of coastal vulnerability to climate change and human impacts, integrated coastal zone management (ICZM) is an increasingly relevant process for the sustainable development of coastal areas, in which scientific input plays a vital role. In the Mediterranean Basin, projected increases in sea level rise and in the magnitude and frequency of extreme weather events pose a major challenge for the management of low-lying coastal ecosystems and human settlements. The bay of Al Hoceima is one of the least studied and largest low-lying coastal areas of the Moroccan Mediterranean coast, and is exposed to the effects of sea level rise and storms. The coast is also a touristic area and one of the most important economic assets in the region. Physical coastal vulnerability assessments, determination of setback lines, and evaluation of coastal aquifer vulnerability to sea level rise are among the principal tools used to help decision makers in such a context. Here we quantified, in the context of sea level rise: (1) the physical vulnerability of the coastline, by developing a standard index methodology based on the five most relevant physical indices for local-scale vulnerability analysis, for a total of 822 50m/50m coastal cells; (2) coastal setback lines, based on shoreline evolutionary trends adjusted to sea level rise scenarios using a digital shoreline Analysis System (DSAS); and (3) the vulnerability to sea water intrusion in the coastal aquifer, using a modified GALDIT index (ground water occurrence, aquifer hydraulic conductivity, depth to groundwater level above the sea; distance from the shore; impact of existing status of sea water intrusion in the area; and thickness of the aquifer), following an integrated GIS approach. We find that 41% of the studied coastline is highly vulnerable to the effects of sea level rise and extreme weather events; 60% of the coastline is in retreat (with rates varying between -2m and -0.2m/y), 30% is in dynamic equilibrium

  6. ALS - resources

    MedlinePlus

    Resources - ALS ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association -- mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (ALS) Registry -- ...

  7. Genetic Contribution to the Management of the Potato Crop (Contribucion Genetica al Manejo del Cultivo de la Papa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different varieties of potato display varying responses to biotic and abiotic stresses. Knowing that a variety is resistant or susceptible to these factors can help to minimize economic losses by management. Timely counteraction against such factors by water, chemical application, and storage proc...

  8. Evolutionary considerations on complex emotions and music-induced emotions. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Gingras, Bruno; Marin, Manuela M.

    2015-06-01

    Recent efforts to uncover the neural underpinnings of emotional experiences have provided a foundation for novel neurophysiological theories of emotions, adding to the existing body of psychophysiological, motivational, and evolutionary theories. Besides explicitly modeling human-specific emotions and considering the interactions between emotions and language, Koelsch et al.'s original contribution to this challenging endeavor is to identify four brain areas as distinct "affect systems" which differ in terms of emotional qualia and evolutionary pathways [1]. Here, we comment on some features of this promising Quartet Theory of Emotions, focusing particularly on evolutionary and biological aspects related to the four affect systems and their relation to prevailing emotion theories, as well as on the role of music-induced emotions.

  9. Bridges from affect to language. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Schmidtke, David S.; Aryani, Arash

    2015-06-01

    The comprehensive Quartet Theory of Human Emotions proposed by Koelsch et al. [4] offers an exceptional synopsis regarding major developments in affective neuroscience, encompassing classical data based on animal studies as well as emotions generally classified as uniquely human. In doing so, it becomes apparent that while general anatomical grounds appear well covered mainly based on animal studies, neuroanatomical underpinnings of interactions between emotion and language may not be readily understood.

  10. A micro-chip initiator with controlled combustion reactivity realized by integrating Al/CuO nanothermite composites on a microhotplate platform

    NASA Astrophysics Data System (ADS)

    Ahn, Ji Young; Kim, Sang Beom; Kim, Ji Hoon; Jang, Nam Su; Kim, Dae Hyun; Lee, Hyung Woo; Kim, Jong Man; Kim, Soo Hyung

    2016-01-01

    The interfacial contact area between the fuel and oxidizer components plays an important role in determining the combustion reactivity of nanothermite composites. In addition, the development of compact and reliable ignition methods can extend the applicability of nanothermite composites to various thermal engineering fields. In this study we report the development of a micro-chip initiator with controlled combustion reactivity using concepts usually applied to microelectromechanical systems (MEMS) and simple nanofabrication processes. The nanothermite composites fabricated in this study consisted of aluminum nanoparticles (Al NPs) as the fuel and copper oxide nanoparticles (CuO NPs) as the oxidizer accumulated on a silicon oxide substrate with a serpentine-shaped gold (Au) electrode. The micro-chip initiator rapidly ignited and exploded when minimal current was supplied. The effects of stacking structures of Al and CuO-based multilayers on the combustion properties were systematically investigated in terms of the pressurization rate, peak explosion time, and heat flow. Pressurization rates of 0.004-0.025 MPa μs-1 and heat flows of 2.0-3.8 kJ g-1 with a commonly fast response time of less than 20 ms could be achieved by simply changing the interfacial structures of the Al and CuO multilayers. The controllability of combustion reactivity of micro-chip initiator can be made for general nanothermite composites composed of Al and various metal oxides (e.g. Fe2O3, CuO, KMnO4, etc). The micro-chip initiator fabricated in this study was reliable, compact, and proved to be a versatile platform, exhibiting controlled combustion reactivity and fast response time, which could be used for various civilian and military thermal engineering applications, such as in initiators and propulsion, welding, and ordinance systems.

  11. Integrated mechanical and material design of quasi-zero-stiffness vibration isolator with superelastic Cu-Al-Mn shape memory alloy bars

    NASA Astrophysics Data System (ADS)

    Araki, Yoshikazu; Kimura, Kosuke; Asai, Takehiko; Masui, Takeshi; Omori, Toshihiro; Kainuma, Ryosuke

    2015-12-01

    Quasi-zero-stiffness (QZS) vibration isolators avoid excessive deformation due to gravity, a critical issue in vertical vibration isolation, by providing restoring force with high initial stiffness and low tangent stiffness around the static equilibrium position. Effective use of geometric nonlinearity often plays a central role in QZS mechanisms. Design of such QZS mechanisms, however, tends to be complex, and it is difficult to realize large loading capacity as well as large stroke length at the same time. This paper attempts to resolve these issues by applying newly developed superelastic Cu-Al-Mn shape memory alloy (SMA) bars, characterized by excellent recoverable strain upon unloading along with small hysteresis and nearly flat stress plateau. These features are realized by material design tailored for obtaining mechanical properties required in QZS mechanisms. The use of such tailored superelastic Cu-Al-Mn SMA bars allows us to easily achieve large loading capacity as well as large stroke length while keeping the QZS mechanism simple and compact. In this paper, we derive design equations, produce a prototype, and conduct shaking table tests and numerical simulations to demonstrate the feasibility of QZS vibration isolator with superelastic Cu-Al-Mn SMA bars.

  12. Determination of integral cross sections of 3H in Al foils monitors irradiated by protons with energies ranging from 40 to 2600 MeV

    NASA Astrophysics Data System (ADS)

    Titarenko, Yu. E.; Batyaev, V. F.; Chauzova, M. V.; Chauzova, M. V.; Kashirin, I. A.; Malinovskiy, S. V.; Pavlov, K. V.; Rogov, V. I.; Titarenko, A. Yu.; Zhivun, V. M.; Mashnik, S. G.; Stankovskiy, A. Yu.

    2016-05-01

    The results of 3H production in Al foil monitors (˜ 59 mg/cm2 thickness) are presented. These foils have been irradiated in 15×15 mm polyethylene bags of ˜ 14 mg/cm2 thickness together with foils of Cr (˜ 395 mg/cm2 thickness) and 56Fe (˜ 332 mg/cm2 thickness) by protons of different energies in a range of 0.04 - 2.6 GeV. The diameters of all the foils were 10.5 mm. The irradiations were carried out at the ITEP accelerator U-10 under the ISTC Project # 3266 in 2006-2009. 3H has been extracted from Al foils using an A307 Sample Oxidizer. An ultra low level liquid scintillation spectrometer Quantulus1220 was used to measure the 3H β-spectra and the SpectraDec software package was applied for spectra processing, deconvolution and 3H activity determination. The values of the Al (p, x)3H reaction cross sections obtained in these experiments are compared with data measured at other labs and with results of simulations by the MCNP6 radiation transport code using the CEM03.03 event generator.

  13. Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

    SciTech Connect

    Karimian, Majid; Idris, M. H.; Ourdjini, A.; Muthu, Kali

    2011-01-17

    The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage of coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.

  14. [Environmental factors in ALS].

    PubMed

    Juntas-Morales, Raul; Pageot, Nicolas; Corcia, Philippe; Camu, William

    2014-05-01

    ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk.

  15. El proceso hacia la integracion de la equidad por genero al curriculo.(The Process of the Integration of Gender Equity in the Curriculum.)

    ERIC Educational Resources Information Center

    Rivera-Bermudez, Carmen D.

    "El Proyecto Colaborativo de Equidad por Genero en la Educacion," or the Collaborative Project for Gender Equity in Education, was undertaken in Puerto Rico between 1990 and 1992 to study how to facilitate the integration of gender equity themes in the curriculum through the direct action of participating teachers. A study examined the attitudes…

  16. Language limits the experience of emotions. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Wood, Adrienne; Niedenthal, Paula

    2015-06-01

    Emotions are phylogenetically ancient and involve complex interactions of neural, behavioral, and physiological processes. A complete theory of emotions must incorporate, or at least be informed by, current knowledge from neurobiology and comparative psychology [1]. The Quartet Theory of Human Emotions by Koelsch and colleagues [2] is therefore a welcome step towards a more integrative affective science.

  17. The critical role of the research question, inclusion criteria, and transparency in meta-analyses of integrity test research: a reply to Harris et al. (2012) and Ones, Viswesvaran, and Schmidt (2012).

    PubMed

    Van Iddekinge, Chad H; Roth, Philip L; Raymark, Patrick H; Odle-Dusseau, Heather N

    2012-05-01

    We clear up a number of misconceptions from the critiques of our meta-analysis (Van Iddekinge, Roth, Raymark, & Odle-Dusseau, 2012). We reiterate that our research question focused on the criterion-related validity of integrity tests for predicting individual work behavior and that our inclusion criteria flowed from this question. We also reviewed the primary studies we could access from Ones, Viswesvaran, and Schmidt's (1993) meta-analysis of integrity tests and found that only about 30% of the studies met our inclusion criteria. Further, analyses of some of the types of studies we had to exclude revealed potentially inflated validity estimates (e.g., corrected validities as high as .80 for polygraph studies). We also discuss our experience trying to obtain primary studies and other information from authors of Harris et al. (2012) and Ones, Viswesvaran, and Schmidt (2012). In addition, we address concerns raised about certain decisions we made and values we used, and we demonstrate how such concerns would have little or no effect on our results or conclusions. Finally, we discuss some other misconceptions about our meta-analysis, as well as some divergent views about the integrity test literature in general. Overall, we stand by our research question, methods, and results, which suggest that the validity of integrity tests for criteria such as job performance and counterproductive work behavior is weaker than the authors of the critiques appear to believe. PMID:22582729

  18. The Quartet does not play alone. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Marco-Pallarés, Josep; Mas-Herrero, Ernest

    2015-06-01

    The study of emotions has been an important topic in cognitive and affective neuroscience in the last decades. In the present manuscript, Koelsch et al. [1] propose a new neurobiological framework based on four emotional core systems (the Quartet), involved in different aspects of human emotion processing. This is an interesting theory that goes beyond classical emotion classification to describe the emotional experience based on four main cerebral components (brainstem, diencephalon, hippocampus, and orbitofrontal cortex). This approach allows the description of different classes of affects, including those that are unique in humans as emotional responses associated to abstract stimuli (for example, aesthetical stimuli such as art and music).

  19. Integrated Duo Wavelength VCSEL Using an Electrically Pumped GaInAs/AlGaAs 980 nm Cavity at the Bottom and an Optically Pumped GaInAs/AlGaInAs 1550 nm Cavity on the Top.

    PubMed

    Islam, Samiha Ishrat; Islam, Arnob; Islam, Saiful

    2014-01-01

    In this work, an integrated single chip dual cavity VCSEL has been designed which comprises an electrically pumped 980 nm bottom VCSEL section fabricated using GaInAs/AlGaAs MQW active region and a 1550 nm top VCSEL section constructed using GaInAs/AlGaInAs MQW active region but optically pumped using half of the produced 980 nm light entering into it from the electrically pumped bottom cavity. In this design, the active region of the intracavity structure 980 nm VCSEL consists of 3 quantum wells (QWs) using Ga0.847In0.153As, 2 barriers using Al0.03Ga0.97As, and 2 separate confinement heterostructures (SCH) using the same material as the barrier. The active region of the top emitting 1550 nm VCSEL consists of 3 QWs using Ga0.47In0.52As, 2 barriers using Al0.3Ga0.17In0.53As, and 2 SCHs using the same material as the barrier. The top DBR and the bottom DBR mirror systems of the 1550 nm VCSEL section plus the top and bottom DBR mirror systems of the 980 nm VCSEL section have been formed using GaAs/Al0.8Ga0.2As. Computations show that the VCSEL is capable of producing 8.5 mW of power at 980 nm from the bottom side and 2 mW of power at the 1550 nm from top side.

  20. Process Integration Study of the Decatur HFCS Plant for American Fructose Company, Decatur, AL [Advanced Industrial Heat Pump Applications and Evaluations

    SciTech Connect

    Eastwood, A.

    1989-11-10

    This work has carried out in two phases: Phase 1, identification of opportunities for heat pumps in industrial applications and Phase 2; evaluation of heat pumps in industrial applications. In Phase 1, pinch analysis was applied to several industrial sites to identify the best opportunities for heat pumping and other forms of heat integration. In Phase 2, more detailed analyses were undertaken, including the evaluation of a heat pump installed as a recommendation of Phase 1.

  1. Measurement of quality factor and losses in superconducting microwave resonator integrated with NbN/AlN/NbN qubit circuit

    NASA Astrophysics Data System (ADS)

    Qiu, W.; Makise, K.; Terai, H.; Nakamura, Y.; Wang, Z.

    2014-05-01

    Dielectric loss from two-level systems (TLSs) formed by local defects have shown a significant impact on the qubit coherence time. These defects can originate in the insulation material for superconducting wires isolation or in the Josephson junction tunnel barrier material. Due to the complexity of the qubit circuit fabrication process, identifying the contribution from each decoherence source is challenging. In an effort to address this issue, we have developed superconducting qubit that consists of full epitaxially-grown NbN/AlN/NbN Josephson junctions in NbN coplanar waveguide (CPW) resonator circuit. The dielectric loss introduced from TLFs in tunnel junction barrier has been largely reduced due to the unique epitaxial feature of the tunnel junction. The quality factor Qi of the CPW resonator was measured and the dielectric loss tanδ is 3×10-4. The relaxation time inferred from the measured resonator quality factor was comparable to the qubit relaxation time.

  2. Monolithically integrated InGaAs/GaAs/AlGaAs quantum well laser grown by MOCVD on exact Ge/Si(001) substrate

    NASA Astrophysics Data System (ADS)

    Aleshkin, V. Ya.; Baidus, N. V.; Dubinov, A. A.; Fefelov, A. G.; Krasilnik, Z. F.; Kudryavtsev, K. E.; Nekorkin, S. M.; Novikov, A. V.; Pavlov, D. A.; Samartsev, I. V.; Skorokhodov, E. V.; Shaleev, M. V.; Sushkov, A. A.; Yablonskiy, A. N.; Yunin, P. A.; Yurasov, D. V.

    2016-08-01

    We report on realization of the InGaAs/GaAs/AlGaAs quantum well laser grown by metallorganic chemical vapor deposition on a virtual Ge-on-Si(001) substrate. The Ge buffer layer has been grown on a nominal Si(001) substrate by solid-source molecular beam epitaxy. Such Ge buffer possessed rather good crystalline quality and smooth surface and so provided the subsequent growth of the high-quality A3B5 laser structure. The laser operation has been demonstrated under electrical pumping at 77 K in the continuous wave mode and at room temperature in the pulsed mode. The emission wavelengths of 941 nm and 992 nm have been obtained at 77 K and 300 K, respectively. The corresponding threshold current densities were estimated as 463 A/cm2 at 77 K and 5.5 kA/cm2 at 300 K.

  3. Aesthetic emotions goals. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Perlovsky, Leonid

    2015-06-01

    Review by Koelsch et al. [10] presents an interdisciplinary theory of emotions, including a neurobiological emotion theory originating in four core emotional systems. The Quartet Theory (QT) includes specifically human emotions and considers the role of language for emotions. This comment considers questions about how the QT can address aesthetic emotions, what class of emotions they are, and what their function in cognition is. Can QT help defining aesthetic emotions neurally and functionally? Such a definition of aesthetic emotions would be necessary for their scientific exploration, because as widely used today there is no definition, aesthetics is defined through art, and art through aesthetics. Since contents of many art museums are not accepted as art by many artists and admirers of art, it is not clear what should be the subject of aesthetic emotions research.

  4. Musical rhythm and affect. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Witek, Maria A. G.; Kringelbach, Morten L.; Vuust, Peter

    2015-06-01

    The Quartet Theory of Human Emotion (QT) proposed by Koelsch et al. [1] adds to existing affective models, e.g. by directing more attention to emotional contagion, attachment-related and non-goal-directed emotions. Such an approach seems particularly appropriate to modelling musical emotions, and music is indeed a recurring example in the text, used to illustrate the distinct characteristics of the affect systems that are at the centre of the theory. Yet, it would seem important for any theory of emotion to account for basic functions such as prediction and anticipation, which are only briefly mentioned. Here we propose that QT, specifically its focus on emotional contagion, attachment-related and non-goal directed emotions, might help generate new ideas about a largely neglected source of emotion - rhythm - a musical property that relies fundamentally on the mechanism of prediction.

  5. Gelingende Integration? Anmerkungen zur Studie von D. Katzenbach u.a. uber den Hamburger Schulversuch "Integrative Grundschule" in ZfPad. 45 (1999), S. 567-590 (Successful Integration? Remarks on the Study by D. Katzenbach et al. on the Hamburg School Experiment "Integrative Elementary School" in ZfPad. 45 (1999), S. 567-590).

    ERIC Educational Resources Information Center

    Roeder, Peter Martin

    1999-01-01

    Critiques two normative premises that guide the researchers' interpretation of results from the Hamburg School Experiment, an empirical study that focused on mainstreaming elementary students diagnosed as needing special education: (1) integrating these children in normal classrooms is legitimated; and (2) social integration should not preclude…

  6. Better assessment science integrating point and nonpoint sources (BASINS) modeling system (version 2.0). EPA Region 4 (AL, FL, GA, KY, MS, NC, SC, TN)

    SciTech Connect

    1999-01-01

    BASINS is a multipurpose environmental analysis system for use by regional, state, and local agencies in performing watershed- and water-quality-based studies. It was developed to address three objectives: To facilitate examination of environmental information; To support analysis of environmental systems; and To provide a framework for examining management alternatives. Because many states and local agencies are moving toward a watershed-based approach, the system is configured to support environmental and ecological studies in a watershed context. It is designed to be flexible. It can support analysis at a variety of scales using tools that range from simple to sophisticated. BASINS was also conceived as a system for supporting the development of total maximum daily loads (TMDLs). Developing TMDLs requires a watershed-based point and nonpoint source analysis for a variety of pollutants. It also lets the user test different management options. BASINS makes watershed and water quality studies easier by bringing key data and analytical components ``under one roof.`` Analysts can efficiently access provided national environmental information, apply assessment and planning tools, and run a variety of proven, robust nonpoint loading and water quality models. A geographic information system (GIS) provides the integrating framework. GIS provides techniques for analyzing landscape information and displaying relationships. Through the use of GIS, BASINS has the flexibility to display and integrate a wide range of information (e.g. land use, point sources discharges, water supply withdrawals) at a scale chosen by the user. BASINS comprises a suite of interrelated components for performing the various aspects of environmental analysis. The six components include (1) nationally derived databases with Data Extraction tools and Project Builders; (2) assessment tools (TARGET, ASSESS, and Data Mining) that address large- and small-scale characterization needs; (3) utilities to

  7. Beyond synergies. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Schwartz, Andrew B.

    2016-07-01

    The target paper by Santello et al. [1] uses the observation that hand shape during grasping can be described by a small set of basic postures, or "synergies," to describe the possible neural basis of motor control during this complex behavior. In the literature, the term "synergy" has been used with a number of different meanings and is still loosely defined, making it difficult to derive concrete analogs of corresponding neural structure. Here, I will define "synergy" broadly, as a set of parameters bound together by a pattern of correlation. With this definition, it can be argued that behavioral synergies are just one facet of the correlational structuring used by the brain to generate behavior. As pointed out in the target article, the structure found in synergies is driven by the physical constraints of our bodies and our surroundings, combined with the behavioral control imparted by our nervous system. This control itself is based on correlational structure which is likely to be a fundamental property of brain function.

  8. Regulating with imagery and the complexity of basic emotions. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Meyer, Marcel; Kuchinke, Lars

    2015-06-01

    Literature, music and the arts have long attested to the complexity of human emotions. Hitherto, psychological and biological theories of emotions have largely neglected this rich heritage. In their review Koelsch and colleagues [1] have embarked upon the pioneering endeavour of integrating the diverse perspectives in emotion research. Noting that the focus of prior neurobiological theories relies mainly on animal studies, the authors sought to complement this body of research with a model of complex ("moral") emotions in humans (henceforth: complex emotions). According to this novel framework, there are four main interacting affective centres in the brain. Each centre is associated with a dominant affective function, such as ascending activation (brainstem), pain/pleasure (diencephalon), attachment-related affects (hippocampus) or moral emotions and unconscious cognitive appraisal (orbitofrontal cortex). Furthermore, language is ascribed a key role in (a) the communication of subjective feeling (reconfiguration) and (b) in the conscious regulation of emotions (by means of logic and rational thought).

  9. Jebel Hafit and the Al Ain oases (Eastern Abu Dhabi, United Arab Emirates): an integrative approach of a cultural landscape through the scope of geodiversity

    NASA Astrophysics Data System (ADS)

    Giusti, Christian; Louchet, André; Beuzen-Waller, Tara; Ragala, Rachid; Pavlopoulos, Kosmas; Fouache, Éric; Cohen, Marianne; Desruelles, Stéphane; Gramond, Delphine

    2015-04-01

    human settlements and occupation, it is possible to characterize a threefold transition: first, the former transition between the pre-Islamic prehistoric societies and the development of Muslim societies; second, the more recent transition between the traditional historical society (farmers) and the contemporary society, characterized by the growth of urbanization, the creation of modern transport infrastructure and the concomitant growth of tourist flows; third, the current transition between the yesterday and tomorrow Al Ain City, due to the transformation of a local town centred on national economics all along the second half of the twentieth century, into an international town more open to the wider world with the management of a possible increased 20 % of tourist flow because of the inscription of Cultural Sites of Al Ain on the UNESCO's World Heritage List. It is not possible to completely ignore the fact that the Jebel Hafit and its foothills are partly crossed by an international boundary. In case of political tensions, this may cause some difficulties for the management of this territory, with contradictory requirements between security, tourism, traditional land use, and scientific research.

  10. The hippocampus is an integral part of the temporal limbic system during emotional processing. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Trost, Wiebke; Frühholz, Sascha

    2015-06-01

    The proposed quartet theory of human emotions by Koelsch and colleagues [1] identifies four different affect systems to be involved in the processing of particular types of emotions. Moreover, the theory integrates both basic emotions and more complex emotion concepts, which include also aesthetic emotions such as musical emotions. The authors identify a particular brain system for each kind of emotion type, also by contrasting them to brain structures that are generally involved in emotion processing irrespective of the type of emotion. A brain system that has been less regarded in emotion theories, but which represents one of the four systems of the quartet to induce attachment related emotions, is the hippocampus.

  11. Variability and situatedness of human emotions. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Nadal, Marcos; Rosselló, Jaume

    2015-06-01

    We commend Koelsch and colleagues [14] for developing a broad and integrative explanation of the neurobiological foundations of emotions. We especially welcome this framework's emphasis on the interaction between language and emotion, and its focus on the characteristically human moral emotions. Emotions elicited by art and aesthetics also seem to be distinctively human, but comparatively little research has been devoted to understanding these. This is probably because they are usually viewed as atypical in several respects. William James [12], for instance, regarded emotional responses to artworks and aesthetic qualities as subtler emotions, because they lacked the strong bodily changes and adaptive value characteristic of coarser emotions, such as joy, anger, or fear. This view is still predominant today, and aesthetic emotions are often distinguished from everyday emotions [13]. However, the notion of a class of aesthetic emotions, separate from everyday emotions, rests on the questionable assumption that artistic and aesthetic experiences and activities are different in essence from everyday experiences and activities. The discontinuity between "aesthetic experience [and] normal processes of living" [9, p. 10], however, is the product of social and cultural developments in Europe during the 18th century [7,15,20]. Distinctions that oppose art to craft, or aesthetic to practical, in reference to objects, behaviors, experiences, and emotions, make little sense in a broader historic and geographic context [1,7,20], and hinder empirical research [7].

  12. Al Composites

    NASA Astrophysics Data System (ADS)

    Chandanayaka, Tharaka; Azarmi, Fardad

    2014-05-01

    In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

  13. Faraday rotation and photoluminescence in heavily Tb3+-doped GeO2-B2O3-Al2O3-Ga2O3 glasses for fiber-integrated magneto-optics

    PubMed Central

    Gao, Guojun; Winterstein-Beckmann, Anja; Surzhenko, Oleksii; Dubs, Carsten; Dellith, Jan; Schmidt, Markus A.; Wondraczek, Lothar

    2015-01-01

    We report on the magneto-optical (MO) properties of heavily Tb3+-doped GeO2-B2O3-Al2O3-Ga2O3 glasses towards fiber-integrated paramagnetic MO devices. For a Tb3+ ion concentration of up to 9.7 × 1021 cm−3, the reported glass exhibits an absolute negative Faraday rotation of ~120 rad/T/m at 632.8 nm. The optimum spectral ratio between Verdet constant and light transmittance over the spectral window of 400–1500 nm is found for a Tb3+ concentration of ~6.5 × 1021 cm−3. For this glass, the crystallization stability, expressed as the difference between glass transition temperature and onset temperature of melt crystallization exceeds 100 K, which is a prerequisite for fiber drawing. In addition, a high activation energy of crystallization is achieved at this composition. Optical absorption occurs in the NUV and blue spectral region, accompanied by Tb3+ photoluminescence. In the heavily doped materials, a UV/blue-to-green photo-conversion gain of ~43% is achieved. The lifetime of photoluminescence is ~2.2 ms at a stimulated emission cross-section σem of ~1.1 × 10−21 cm2 for ~ 5.0 × 1021 cm−3 Tb3+. This results in an optical gain parameter σem*τ of ~2.5 × 10−24 cm2s, what could be of interest for implementation of a Tb3+ fiber laser. PMID:25754819

  14. Faraday rotation and photoluminescence in heavily Tb(3+)-doped GeO2-B2O3-Al2O3-Ga2O3 glasses for fiber-integrated magneto-optics.

    PubMed

    Gao, Guojun; Winterstein-Beckmann, Anja; Surzhenko, Oleksii; Dubs, Carsten; Dellith, Jan; Schmidt, Markus A; Wondraczek, Lothar

    2015-03-10

    We report on the magneto-optical (MO) properties of heavily Tb(3+)-doped GeO2-B2O3-Al2O3-Ga2O3 glasses towards fiber-integrated paramagnetic MO devices. For a Tb(3+) ion concentration of up to 9.7 × 10(21) cm(-3), the reported glass exhibits an absolute negative Faraday rotation of ~120 rad/T/m at 632.8 nm. The optimum spectral ratio between Verdet constant and light transmittance over the spectral window of 400-1500 nm is found for a Tb(3+) concentration of ~6.5 × 10(21) cm(-3). For this glass, the crystallization stability, expressed as the difference between glass transition temperature and onset temperature of melt crystallization exceeds 100 K, which is a prerequisite for fiber drawing. In addition, a high activation energy of crystallization is achieved at this composition. Optical absorption occurs in the NUV and blue spectral region, accompanied by Tb(3+) photoluminescence. In the heavily doped materials, a UV/blue-to-green photo-conversion gain of ~43% is achieved. The lifetime of photoluminescence is ~2.2 ms at a stimulated emission cross-section σem of ~1.1 × 10(-21) cm(2) for ~ 5.0 × 10(21) cm(-3) Tb(3+). This results in an optical gain parameter σem*τ of ~2.5 × 10(-24) cm(2)s, what could be of interest for implementation of a Tb(3+) fiber laser.

  15. Faraday rotation and photoluminescence in heavily Tb3+-doped GeO2-B2O3-Al2O3-Ga2O3 glasses for fiber-integrated magneto-optics

    NASA Astrophysics Data System (ADS)

    Gao, Guojun; Winterstein-Beckmann, Anja; Surzhenko, Oleksii; Dubs, Carsten; Dellith, Jan; Schmidt, Markus A.; Wondraczek, Lothar

    2015-03-01

    We report on the magneto-optical (MO) properties of heavily Tb3+-doped GeO2-B2O3-Al2O3-Ga2O3 glasses towards fiber-integrated paramagnetic MO devices. For a Tb3+ ion concentration of up to 9.7 × 1021 cm-3, the reported glass exhibits an absolute negative Faraday rotation of ~120 rad/T/m at 632.8 nm. The optimum spectral ratio between Verdet constant and light transmittance over the spectral window of 400-1500 nm is found for a Tb3+ concentration of ~6.5 × 1021 cm-3. For this glass, the crystallization stability, expressed as the difference between glass transition temperature and onset temperature of melt crystallization exceeds 100 K, which is a prerequisite for fiber drawing. In addition, a high activation energy of crystallization is achieved at this composition. Optical absorption occurs in the NUV and blue spectral region, accompanied by Tb3+ photoluminescence. In the heavily doped materials, a UV/blue-to-green photo-conversion gain of ~43% is achieved. The lifetime of photoluminescence is ~2.2 ms at a stimulated emission cross-section σem of ~1.1 × 10-21 cm2 for ~ 5.0 × 1021 cm-3 Tb3+. This results in an optical gain parameter σem*τ of ~2.5 × 10-24 cm2s, what could be of interest for implementation of a Tb3+ fiber laser.

  16. Slimplectic Integrators: Variational Integrators for Nonconservative systems

    NASA Astrophysics Data System (ADS)

    Tsang, David

    2016-05-01

    Symplectic integrators are widely used for long-term integration of conservative astrophysical problems due to their ability to preserve the constants of motion; however, they cannot in general be applied in the presence of nonconservative interactions. Here we present the “slimplectic” integrator, a new type of numerical integrator that shares many of the benefits of traditional symplectic integrators yet is applicable to general nonconservative systems. We utilize a fixed-time-step variational integrator formalism applied to a newly developed principle of stationary nonconservative action (Galley, 2013, Galley et al 2014). As a result, the generalized momenta and energy (Noether current) evolutions are well-tracked. We discuss several example systems, including damped harmonic oscillators, Poynting–Robertson drag, and gravitational radiation reaction, by utilizing our new publicly available code to demonstrate the slimplectic integrator algorithm. Slimplectic integrators are well-suited for integrations of systems where nonconservative effects play an important role in the long-term dynamical evolution. As such they are particularly appropriate for cosmological or celestial N-body dynamics problems where nonconservative interactions, e.g., gas interactions or dissipative tides, can play an important role.

  17. Slimplectic Integrators: Variational Integrators for Nonconservative systems

    NASA Astrophysics Data System (ADS)

    Tsang, David

    2016-01-01

    Symplectic integrators are widely used for long-term integration of conservative astrophysical problems due to their ability to preserve the constants of motion; however, they cannot in general be applied in the presence of nonconservative interactions. In this Letter, we develop the "slimplectic" integrator, a new type of numerical integrator that shares many of the benefits of traditional symplectic integrators yet is applicable to general nonconservative systems. We utilize a fixed-time-step variational integrator formalism applied to the principle of stationary nonconservative action developed in Galley et al. As a result, the generalized momenta and energy (Noether current) evolutions are well-tracked. We discuss several example systems, including damped harmonic oscillators, Poynting-Robertson drag, and gravitational radiation reaction, by utilizing our new publicly available code to demonstrate the slimplectic integrator algorithm. Slimplectic integrators are well-suited for integrations of systems where nonconservative effects play an important role in the long-term dynamical evolution. As such they are particularly appropriate for cosmological or celestial N-body dynamics problems where nonconservative interactions, e.g., gas interactions or dissipative tides, can play an important role.

  18. [Sex differences in the integrated stroke management in a rural healthcare area in Asturias].

    PubMed

    Lopez-Martinez, T; Bernardo-Cofino, J; Garcia-Prieto, E; Feito-Alvarez, M; de Dios-Del Valle, R; Calleja-Puerta, S

    2016-08-16

    Introduccion. Las diferencias de sexo y el caracter (rural o urbano) de las poblaciones determinan en gran medida el abordaje integral de patologias dependientes del tiempo, como el ictus, principal causa de hospitalizacion y mortalidad femenina en nuestro medio. Objetivo. Determinar si en un area sanitaria rural del Principado de Asturias se ponen de manifiesto las caracteristicas diferenciales entre mujeres y hombres con ictus. Pacientes y metodos. Estudio descriptivo retrospectivo realizado en el Hospital de Jarrio. Se revisaron variables a traves de las historias clinicas informatizadas de los pacientes que sufrieron ictus en 2013. Resultados. Se produjeron 126 altas totales, el 53,2% en las mujeres, que sufrieron la enfermedad con un retraso de cinco años (p < 0,008) en relacion con los varones, los cuales fueron mas fumadores y consumidores perjudiciales de alcohol (p < 0,000). La demora prehospitalaria no arrojo diferencias de sexo significativas. El trastorno del lenguaje fue el sintoma principal en el grupo femenino (p < 0,008), que registro una puntuacion superior en la National Institute of Health Stroke Scale (p < 0,046). Los estudios complementarios, como el Holter (p < 0,04) y la ecografia de troncos supraaorticos (p < 0,02), se realizaron menos en las mujeres, que recibieron un tratamiento principalmente conservador con mayor hidratacion parenteral (p < 0,017) y reposo. El grupo femenino sufrio mas complicaciones, discapacidad al alta (p < 0,001) y a los tres meses (p < 0,004), y registro porcentajes mas elevados de institucionalizacion posterior (p < 0,005). Conclusiones. Existen diferencias de sexo demograficas, en el perfil de riesgo cerebrovascular, la presentacion clinica, el manejo hospitalario y la comorbilidad del ictus en esta poblacion rural, que sugieren areas de mejora.

  19. Scattering theory with path integrals

    SciTech Connect

    Rosenfelder, R.

    2014-03-15

    Starting from well-known expressions for the T-matrix and its derivative in standard nonrelativistic potential scattering, I rederive recent path-integral formulations due to Efimov and Barbashov et al. Some new relations follow immediately.

  20. On the role of language from basic to cultural modulation of affect. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Conrad, Markus

    2015-06-01

    Koelsch et al. [1] propose the following two emotion-relevant functions of language: "(a) With regard to subjective feelings, language is an important means to express as well as communicate emotions (and, therefore, also to elicit emotions in other individuals). (b) With regard to conscious appraisal, language is an important means to regulate emotions" - assuming that "activity of affect systems and effector systems is synthesized into an emotion percept (pre-verbal subjective feeling), which can be transformed (or reconfigured) into a symbolic code such as language".

  1. Are we ready to move beyond the reductionist approach of classical synergy control?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Lacquaniti, Francesco; Ivanenko, Yuri P.; Zago, Myrka

    2016-07-01

    Starting from the classical concepts introduced by Sherrington [1] and considerably elaborated by Bernstein [2], much has been learned about motor synergies in the last several years. The contributions of the group funded by the European project "The Hand Embodied" are remarkable in the field of biological and robotic control of the hand based on synergies, and they are reflected in this enjoyable review [3]. There, Santello et al. adopt Bernstein's definition of motor synergies as multiple elements working together towards a common goal, with the result that multiple degrees of freedom are controlled within a lower-dimensional space than the available number of dimensions.

  2. Working hard to make a simple definition of synergies. Comment on: "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Alessandro, Cristiano; Oliveira Barroso, Filipe; Tresch, Matthew

    2016-07-01

    The paper "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" [1] presents a comprehensive review of the work carried out as part of the EU funded project "The Hand Embodied". The work uses the concept of "synergy" to study the neuromuscular control of the human hand and to design novel robotics systems. The project has been very productive and has made important contributions. We are therefore confident that it will lead to further advancements and experiments in the future.

  3. Cenomanian-Turonian biostratigraphy of the Jardas Al Abid area, Al Jabal Al Akhdar, northeast Libya

    NASA Astrophysics Data System (ADS)

    El Qot, Gamal M.; Abdulsamad, Esam O.

    2016-09-01

    The Upper Cenomanian-Turonian succession exposed at Jardas al'Abid area consists mainly of carbonates with siliciclastic intercalations. This succession is subdivided lithostratigraphically into: Qasr al'Abid (Late Cenomanian) and Al Baniyah (Late Cenomanian-Coniacian) formations. This sequence is relatively rich in macrofossil assemblages especially bivalves, gastropods, and echinoids with rare ammonites. Based on the first occurrence (FO) and last occurrence (LO) of some index species of these macrofossil groups, an integrated biostratigraphic framework has been constructed. The studied Cenomanian-Turonian sequence is subdivided biostratigraphically into three ammonite biozones; Pseudaspidoceras pseudonodosoides Total Range Zone, Choffaticeras segne Total Range Zone, and Coilopoceras requienianum Total Range Zone. Based on the rest of macrofossil assemblages other than the ammonites, eight biozones were recognized; Mecaster batnensis Total Range Zone, Ceratostreon flabellatum-Neithea dutrugei Acme Zone, Costagyra olisiponensis Acme Zone, Pycnodonte (Phygraea) vesicularis vesiculosa Acme Zone, Mytiloides labiatus Total Range Zone = Mecaster turonensis Acme Zone, Rachiosoma rectilineatum-Curvostrea rouvillei-Tylostoma (T.) globosum Assemblage Zone, Radiolites sp.-Apricardia? matheroni Total Range Zone, and Nerinea requieniana Total Range Zone. Most of the proposed biozones are recorded for the first time from Libya. The integration among these biozones as well as local and inter-regional correlation of the biozones have been discussed. The stage boundaries of the studied stratigraphic intervals are discussed, where the Cenomanian/Turonian boundary is delineated at the last occurrence (LO) of Pseudaspidoceras pseudonodosoides (Choffat), while the Turonian/Coniacian boundary is delineated arbitrary being agree with the LO of the Turonian fauna.

  4. Integrated Means Integrity

    ERIC Educational Resources Information Center

    Odegard, John D.

    1978-01-01

    Describes the operation of the Cessna Pilot Center (CPC) flight training systems. The program is based on a series of integrated activities involving stimulus, response, reinforcement and association components. Results show that the program can significantly reduce in-flight training time. (CP)

  5. Integrating Art.

    ERIC Educational Resources Information Center

    BCATA Journal for Art Teachers, 1991

    1991-01-01

    These articles focus on art as a component of interdisciplinary integration. (1) "Integrated Curriculum and the Visual Arts" (Anna Kindler) considers various aspects of integration and implications for art education. (2) "Integration: The New Literacy" (Tim Varro) illustrates how the use of technology can facilitate cross-curricular integration.…

  6. Evolutionary perspectives on emotions and their link to intentions, dispositions and behavior. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Wildgruber, Dirk; Kreifelts, Benjamin

    2015-06-01

    Koelsch and coworkers present a sophisticated neuroanatomical model of emotions comprising four affect-systems and four output-systems, each bound to a specific brain area [1]. Moreover, they suggest the emergence of distinct components of subjective feelings or "emotion percepts" due to integration of the activation across these subsystems. Incorporating numerous neurobiological, psychological and philosophical findings on human emotions, the model reflects an extensive interdisciplinary approach. Considering an evolutionary perspective, however, we would like to address some issues concerning emotions and their link to intentions, dispositions and behavior that are not fully covered by the Quartet Model. Charles Darwin pointed out that individuals that are better adapted to their environment have increased chances of survival and reproduction. Therefore, natural selection leads to a rising prevalence of properties offering a survival benefit across generations [2]. To better understand the biological functions of emotions we propose to ask the question: How do emotions provide a benefit for survival and reproduction?

  7. Pseudomorphic In(y)Ga(1-y)As/GaAs/Al(x)Ga(1-x)As single quantum well surface-emitting lasers with integrated 45 deg beam deflectors

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hoon; Larsson, Anders; Lee, Luke P.

    1991-01-01

    The paper reports on the first demonstration of pseudomorphic InGaAs single quantum well surface-emitting lasers (SELs), with etched vertical mirrors and integrated 45-deg beam deflectors fabricated by ion beam etching. 100-micron-wide broad-area SELs exhibited a threshold current of 320 mA, a total power of 126 mW, and a total external differential quantum efficiency of 0.09 W/A for a 500-micron-long cavity. The perpendicular far-field pattern of broad-area SELs showed a full width at half maximum of about 20 deg. Lasers with various types of cavities fabricated from the same wafer were compared. Broad-area edge-emitting lasers had a threshold current of 200 mA, a total power of 700 mW, and a total external differential quantum efficiency of 0.52 W/A.

  8. Phase competition in ternary Ti-Ni-Al system

    NASA Astrophysics Data System (ADS)

    Wierzba, Bartek

    2016-07-01

    In this paper the reactive diffusion in Ti-Ni-Al system is discussed at 1173 K. The calculation method based on the binary approach is presented. The key kinetic parameter is Wagner integral diffusion coefficient. The experimental and simulation results of reactive diffusion between pure Ti and β-NiAl are compared at 1173 K after 100 h.

  9. Amyotrophic Lateral Sclerosis (ALS)

    MedlinePlus

    ... Pictures of ALS Mutant Proteins Support Two Major Theories About How the Disease is Caused May 2003 ... All NINDS-prepared information is in the public domain and may be freely copied. Credit to the ...

  10. Genetic Testing for ALS

    MedlinePlus

    ... Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic ... guarantee a person will develop symptoms of ALS. Genetic Counseling If there is more than one person ...

  11. All About ALS

    MedlinePlus

    ... External link, please review our exit disclaimer . Subscribe All About ALS Understanding a Devastating Disorder In the ... a coffee pot, or button a shirt. Eventually, all muscles under voluntary control are affected, and people ...

  12. What Is ALS?

    MedlinePlus

    ... scarring or hardening ("sclerosis") in the region. Motor neurons reach from the brain to the spinal cord ... the body. The progressive degeneration of the motor neurons in ALS eventually leads to their demise. When ...

  13. Extensive genetics of ALS

    PubMed Central

    Calvo, Andrea; Mazzini, Letizia; Cantello, Roberto; Mora, Gabriele; Moglia, Cristina; Corrado, Lucia; D'Alfonso, Sandra; Majounie, Elisa; Renton, Alan; Pisano, Fabrizio; Ossola, Irene; Brunetti, Maura; Traynor, Bryan J.; Restagno, Gabriella

    2012-01-01

    Objective: To assess the frequency and clinical characteristics of patients with mutations of major amyotrophic lateral sclerosis (ALS) genes in a prospectively ascertained, population-based epidemiologic series of cases. Methods: The study population includes all ALS cases diagnosed in Piemonte, Italy, from January 2007 to June 2011. Mutations of SOD1, TARDBP, ANG, FUS, OPTN, and C9ORF72 have been assessed. Results: Out of the 475 patients included in the study, 51 (10.7%) carried a mutation of an ALS-related gene (C9ORF72, 32; SOD1, 10; TARDBP, 7; FUS, 1; OPTN, 1; ANG, none). A positive family history for ALS or frontotemporal dementia (FTD) was found in 46 (9.7%) patients. Thirty-one (67.4%) of the 46 familial cases and 20 (4.7%) of the 429 sporadic cases had a genetic mutation. According to logistic regression modeling, besides a positive family history for ALS or FTD, the chance to carry a genetic mutation was related to the presence of comorbid FTD (odds ratio 3.5; p = 0.001), and age at onset ≤54 years (odds ratio 1.79; p = 0.012). Conclusions: We have found that ∼11% of patients with ALS carry a genetic mutation, with C9ORF72 being the commonest genetic alteration. Comorbid FTD or a young age at onset are strong indicators of a possible genetic origin of the disease. PMID:23100398

  14. Acoustic integrated extinction

    PubMed Central

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time-dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency. PMID:27547100

  15. Human emotion in the brain and the body: Why language matters. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Herbert, Cornelia

    2015-06-01

    What is an Emotion? This question has fascinated scientific research since William James. Despite the fact that a consensus has been reached about the biological origin of emotions, uniquely human aspects of emotions are still poorly understood. One of these blind spots concerns the relationship between emotion and human language. Historically, many theories imply a duality between emotions on the one hand and cognitive functions such as language on the other hand. Especially for symbolic forms of written language and word processing, it has been assumed that semantic information would bear no relation to bodily, affective, or sensorimotor processing (for an overview see Ref. [1]). The Quartet Theory proposed by Koelsch and colleagues [2] could provide a solution to this problem. It offers a novel, integrative neurofunctional model of human emotions which considers language and emotion as closely related. Crucially, language - be it spoken or written - is assumed to "regulate, modulate, and partly initiate" activity in core affective brain systems in accord with physical needs and individual concerns [cf. page 34, line 995]. In this regard, the Quartet Theory combines assumptions from earlier bioinformational theories of emotions [3], contemporary theories of embodied cognition [4], and appraisal theories such as the Component Process Model [5] into one framework, thereby providing a holistic model for the neuroscientific investigation of human emotion processing at the interface of emotion and cognition, mind and body.

  16. Learning in robotic manipulation: The role of dimensionality reduction in policy search methods. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Ficuciello, Fanny; Siciliano, Bruno

    2016-07-01

    A question that often arises, among researchers working on artificial hands and robotic manipulation, concerns the real meaning of synergies. Namely, are they a realistic representation of the central nervous system control of manipulation activities at different levels and of the sensory-motor manipulation apparatus of the human being, or do they constitute just a theoretical framework exploiting analytical methods to simplify the representation of grasping and manipulation activities? Apparently, this is not a simple question to answer and, in this regard, many minds from the field of neuroscience and robotics are addressing the issue [1]. The interest of robotics is definitely oriented towards the adoption of synergies to tackle the control problem of devices with high number of degrees of freedom (DoFs) which are required to achieve motor and learning skills comparable to those of humans. The synergy concept is useful for innovative underactuated design of anthropomorphic hands [2], while the resulting dimensionality reduction simplifies the control of biomedical devices such as myoelectric hand prostheses [3]. Synergies might also be useful in conjunction with the learning process [4]. This aspect is less explored since few works on synergy-based learning have been realized in robotics. In learning new tasks through trial-and-error, physical interaction is important. On the other hand, advanced mechanical designs such as tendon-driven actuation, underactuated compliant mechanisms and hyper-redundant/continuum robots might exhibit enhanced capabilities of adapting to changing environments and learning from exploration. In particular, high DoFs and compliance increase the complexity of modelling and control of these devices. An analytical approach to manipulation planning requires a precise model of the object, an accurate description of the task, and an evaluation of the object affordance, which all make the process rather time consuming. The integration of

  17. Can modular psychological concepts like affect and emotion be assigned to a distinct subset of regional neural circuits?. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    NASA Astrophysics Data System (ADS)

    Fehr, Thorsten; Herrmann, Manfred

    2015-06-01

    The proposed Quartet Theory of Human Emotions by Koelsch and co-workers [11] adumbrates evidence from various scientific sources to integrate and assign the psychological concepts of 'affect' and 'emotion' to four brain circuits or to four neuronal core systems for affect-processing in the brain. The authors differentiate between affect and emotion and assign several facultative, or to say modular, psychological domains and principles of information processing, such as learning and memory, antecedents of affective activity, emotion satiation, cognitive complexity, subjective quality feelings, degree of conscious appraisal, to different affect systems. Furthermore, they relate orbito-frontal brain structures to moral affects as uniquely human, and the hippocampus to attachment-related affects. An additional feature of the theory describes 'emotional effector-systems' for motor-related processes (e.g., emotion-related actions), physiological arousal, attention and memory that are assumed to be cross-linked with the four proposed affect systems. Thus, higher principles of emotional information processing, but also modular affect-related issues, such as moral and attachment related affects, are thought to be handled by these four different physiological sub-systems that are on the other side assumed to be highly interwoven at both physiological and functional levels. The authors also state that the proposed sub-systems have many features in common, such as the selection and modulation of biological processes related to behaviour, perception, attention and memory. The latter aspect challenges an ongoing discussion about the mind-body problem: To which degree do the proposed sub-systems 'sufficiently' cover the processing of complex modular or facultative emotional/affective and/or cognitive phenomena? There are current models and scientific positions that almost completely reject the idea that modular psychological phenomena are handled by a distinct selection of

  18. ALS superbend magnet system

    SciTech Connect

    Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

    2000-09-15

    The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

  19. Modulus measurements in ordered Co-Al, Fe-Al, and Ni-Al alloys

    NASA Technical Reports Server (NTRS)

    Harmouche, M. R.; Wolfenden, A.

    1985-01-01

    The composition and/or temperature dependence of the dynamic Young's modulus for the ordered B2 Co-Al, Fe-Al, and Ni-Al aluminides has been investigated using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The modulus has been measured in the composition interval 48.49 to 52.58 at. pct Co, 50.87 to 60.2 at. pct Fe, and 49.22 to 55.95 at. pct Ni for Co-Al, Fe-Al, and Ni-Al, respectively. The measured values for Co-Al are in the temperature interval 300 to 1300 K, while those for the other systems are for ambient temperature only. The data points show that Co-Al is stiffer than Fe-Al, which is stiffer than Ni-Al. The data points for Fe-Al and Ni-Al are slightly higher than those reported in the literature.

  20. Al Shanker Remembers.

    ERIC Educational Resources Information Center

    American Educator, 2000

    2000-01-01

    In a 1996 interview shortly before his death, Al Shanker, longtime president of the American Federation of Teachers, discussed such topics as: his own educational experiences; how he learned about political fighting in the Boy Scouts; the appeal of socialism; multinational corporations and the nation state; teaching tough students; and John Dewey…

  1. Fosetyl-al

    Integrated Risk Information System (IRIS)

    Fosetyl - al ; CASRN 39148 - 24 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  2. ALS renewal moves forward

    NASA Astrophysics Data System (ADS)

    Falcone, R. W.; Feinberg, B.; Hussain, Z.; Kirz, J.; Krebs, G. F.; Padmore, H. A.; Robin, D. S.; Robinson, A. L.

    2007-11-01

    As the result of an extensive long-term planning process involving all its stakeholders—management, staff, and users—the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2-3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates.

  3. Teaching Integrity

    ERIC Educational Resources Information Center

    Saunders, Sue; Butts, Jennifer Lease

    2011-01-01

    Integrity is one of those essential yet highly ambiguous concepts. For the purpose of this chapter, integrity is defined as that combination of both attributes and actions that makes entities appear to be whole and ethical, as well as consistent. Like the concepts of leadership or wisdom or community or collaboration, integrity is a key element of…

  4. Ausbildung als zentrale Aufgabe

    NASA Astrophysics Data System (ADS)

    Krämer, Walter; Schmerbach, Sibylle

    Anders als Lesen und Schreiben zählen Grundkenntnisse in Statistik heute noch nicht zu den Voraussetzungen einer sinnvollen Teilhabe am Sozialgeschehen. Und auch in der akademischen Statistik-Ausbildung gibt es noch einiges zu tun. Das vorliegende Kapitel zeichnet die Geschichte dieser akademischen Ausbildung an deutschen Universitäten nach dem zweiten Weltkrieg nach, stellt aktuelle Defizite vor und weist auf mögliche Verbesserungen hin.

  5. Tour by Saudi prince Salman Abdelazize Al-Saud prior to mission

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Tour by Saudi prince Salman Abdelazize Al-Saud, payload specialists for STS 51-G mission, prior to mission. Al-Saud and Abdulmohsen Hamad Al-Bassam, the backup payload specialist, man the controls on the flight deck of the crew compartment trainer in the Shuttle mockup and integration laboratory (29788); the Saudi payload specialists share the hatch of the crew compartment trainer (29789); Portrait view of Abdulmohsen Hamad Al-Bassam during a visit to the Shuttle mockup and integraion laboratory (29790); Don Sirroco, left, explains the middeck facilities in the Shuttle mockup and integration laboratory (29791); Portrait view of Sultan Salman Abdelazize Al-Saud in the Shuttle Mockup and Integration laboratory (29792); The Saudi payload specialists witness a space food demonstration in the life sciences laboratory at JSC. Al-Saud (left) and Al-Bassam (second left) listen as Rita M. Rapp, food specialist, discusses three preparations of re-hydratable food for space travelers. Lynn S. Coll

  6. Systems integration and demonstration of advanced reusable structure for ALS

    NASA Technical Reports Server (NTRS)

    Gibbins, Martin N.

    1991-01-01

    The objective was to investigate the potential of advanced material to achieve life cycle cost (LCC) benefits for reusable structure on the advanced launch system. Three structural elements were investigated - all components of an Advanced Launch System reusable propulsion/avionics module. Leading aeroshell configurations included sandwich structure using titanium, graphite/polyimide (Gr/PI), or high-temperature aluminum (HTA) face sheets. Thrust structure truss concepts used titanium, graphite/epoxy, or silicon carbide/aluminum struts. Leading aft bulkhead concepts employed graphite epoxy and aluminum. The technical effort focused on the aeroshell because the greatest benefits were expected there. Thermal analyses show the structural temperature profiles during operation. Finite element analyses show stresses during splash-down. Weight statements and manufacturing cost estimates were prepared for calculation of LCC for each design. The Gr/PI aeroshell showed the lowest potential LCC, but the HTA aeroshell was judged to be lower risk. A technology development plan was prepared to validate the applicable structural technology.

  7. Discovery of a metastable Al20Sm4 phase

    DOE PAGES

    Ye, Z.; Zhang, F.; Sun, Y.; Mendelev, M. I.; Ott, R. T.; Park, E.; Besser, M. F.; Kramer, M. J.; Ding, Z.; Wang, C. -Z.; et al

    2015-03-09

    In this study, we present an efficient genetic algorithm, integrated with experimental diffraction data, to solve a nanoscale metastable Al20Sm4 phase that evolves during crystallization of an amorphous magnetron sputtered Al90Sm10 alloy. The excellent match between calculated and experimental X-ray diffraction patterns confirms an accurate description of this metastable phase. Molecular dynamic simulations of crystal growth from the liquid phase predict the formation of disordered defects in the devitrified crystal.

  8. AL Amyloidosis and Agent Orange

    MedlinePlus

    ... for survivors' benefits . Research on AL amyloidosis and herbicides The Health and Medicine Division (formally known as ... to the compounds of interest found in the herbicide Agent Orange and AL amyloidosis." VA made a ...

  9. Modeling neuronal vulnerability in ALS.

    PubMed

    Roselli, Francesco; Caroni, Pico

    2014-08-20

    Using computational models of motor neuron ion fluxes, firing properties, and energy requirements, Le Masson et al. (2014) reveal how local imbalances in energy homeostasis may self-amplify and contribute to neurodegeneration in ALS.

  10. SPI measurements of Galactic 26Al

    NASA Astrophysics Data System (ADS)

    Diehl, R.; Knödlseder, J.; Lichti, G. G.; Kretschmer, K.; Schanne, S.; Schönfelder, V.; Strong, A. W.; von Kienlin, A.; Weidenspointner, G.; Winkler, C.; Wunderer, C.

    2003-11-01

    The precision measurement of the 1809 keV gamma-ray line from Galactic 26Al is one of the goals of the SPI spectrometer on INTEGRAL with its Ge detector camera. We aim for determination of the detailed shape of this gamma-ray line, and its variation for different source regions along the plane of the Galaxy. Data from the first part of the core program observations of the first mission year have been inspected. A clear detection of the 26Al line at =~ 5-7 sigma significance demonstrates that SPI will deepen 26Al studies. The line intensity is consistent with expectations from previous experiments, and the line appears narrower than the 5.4 keV FWHM reported by GRIS, more consistent with RHESSI's recent value. Only preliminary statements can be made at this time, however, due to the multi-component background underlying the signal at =~ 40 times higher intensity than the signal from Galactic 26Al.

  11. Al Jazirah, Sudan

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Al Jazirah (also Gezira) is one of the 26 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It is a well populated area suitable for agriculture. The area was at the southern end of Nubia and little is known about its ancient history and only limited archaeological work has been conducted in this area. The region has benefited from the Gezira Scheme, a program to foster cotton farming begun in 1925. At that time the Sennar Dam and numerous irrigation canals were built. Al Jazirah became the Sudan's major agricultural region with more than 2.5 million acres (10,000 km) under cultivation. The initial development project was semi-private, but the government nationalized it in 1950. Cotton production increased in the 1970s but by the 1990s increased wheat production has supplanted a third of the land formerly seeded with cotton.

    The image was acquired December 25, 2006, covers an area of 56 x 36.4 km, and is located near 14.5 degrees north latitude, 33.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  12. Integrated Learning

    ERIC Educational Resources Information Center

    Gnanakan, Ken

    2012-01-01

    This book upholds the idea of learning and education as a means to individual development and social empowerment. It presents a holistic picture, looking at learning as an integral part of one's social and physical life. Strongly differing from existing classroom perspectives, the book analyses integrated learning at its broadest possible…

  13. Integrated Science.

    ERIC Educational Resources Information Center

    Rainey, Larry; Miller, Roxanne Greitz

    1997-01-01

    Describes the Integrated Science program that integrates biology, earth/space science, chemistry, and physics over a three-year, spiraling sequence arranged around broad themes such as cycles, changes, patterns, and waves. Includes weekly telecasts via public television and satellite, teacher manuals, student handbooks, e-mail connections, staff…

  14. Integrative Education.

    ERIC Educational Resources Information Center

    Walker, Dean

    1995-01-01

    In contrast with subject-bound education, integrative education promotes the construction of broad "mental programs" that require students to use skills and information in new, realistic contexts. Early childhood education has long been a model of integrative education, emphasizing the whole child and offering a wide range of experiences that…

  15. Integrated care

    PubMed Central

    Gröne, Oliver; Garcia-Barbero, Mila

    2001-01-01

    Abstract The WHO European Office for Integrated Health Care Services in Barcelona is an integral part of the World Health Organizations' Regional Office for Europe. The main purpose of the Barcelona office is within the integration of services to encourage and facilitate changes in health care services in order to promote health and improve management and patient satisfaction by working for quality, accessibility, cost-effectiveness and participation. This position paper outlines the need for Integrated Care from a European perspective, provides a theoretical framework for the meaning of Integrated Care and its strategies and summarizes the programmes of the office that will support countries in the WHO European Region to improve health services. PMID:16896400

  16. Emission mechanisms in Al-rich AlGaN/AlN quantum wells assessed by excitation power dependent photoluminescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Iwata, Yoshiya; Banal, Ryan G.; Ichikawa, Shuhei; Funato, Mitsuru; Kawakami, Yoichi

    2015-02-01

    The optical properties of Al-rich AlGaN/AlN quantum wells are assessed by excitation-power-dependent time-integrated (TI) and time-resolved (TR) photoluminescence (PL) measurements. Two excitation sources, an optical parametric oscillator and the 4th harmonics of a Ti:sapphire laser, realize a wide range of excited carrier densities between 1012 and 1021 cm-3. The emission mechanisms change from an exciton to an electron-hole plasma as the excitation power increases. Accordingly, the PL decay time is drastically reduced, and the integrated PL intensities increase in the following order: linearly, super-linearly, linearly again, and sub-linearly. The observed results are well accounted for by rate equations that consider the saturation effect of non-radiative recombination processes. Using both TIPL and TRPL measurements allows the density of non-radiative recombination centers, the internal quantum efficiency, and the radiative recombination coefficient to be reliably extracted.

  17. “SLIMPLECTIC” INTEGRATORS: VARIATIONAL INTEGRATORS FOR GENERAL NONCONSERVATIVE SYSTEMS

    SciTech Connect

    Tsang, David; Turner, Alec; Galley, Chad R.; Stein, Leo C.

    2015-08-10

    Symplectic integrators are widely used for long-term integration of conservative astrophysical problems due to their ability to preserve the constants of motion; however, they cannot in general be applied in the presence of nonconservative interactions. In this Letter, we develop the “slimplectic” integrator, a new type of numerical integrator that shares many of the benefits of traditional symplectic integrators yet is applicable to general nonconservative systems. We utilize a fixed-time-step variational integrator formalism applied to the principle of stationary nonconservative action developed in Galley et al. As a result, the generalized momenta and energy (Noether current) evolutions are well-tracked. We discuss several example systems, including damped harmonic oscillators, Poynting–Robertson drag, and gravitational radiation reaction, by utilizing our new publicly available code to demonstrate the slimplectic integrator algorithm. Slimplectic integrators are well-suited for integrations of systems where nonconservative effects play an important role in the long-term dynamical evolution. As such they are particularly appropriate for cosmological or celestial N-body dynamics problems where nonconservative interactions, e.g., gas interactions or dissipative tides, can play an important role.

  18. "Slimplectic" Integrators: Variational Integrators for General Nonconservative Systems

    NASA Astrophysics Data System (ADS)

    Tsang, David; Galley, Chad R.; Stein, Leo C.; Turner, Alec

    2015-08-01

    Symplectic integrators are widely used for long-term integration of conservative astrophysical problems due to their ability to preserve the constants of motion; however, they cannot in general be applied in the presence of nonconservative interactions. In this Letter, we develop the “slimplectic” integrator, a new type of numerical integrator that shares many of the benefits of traditional symplectic integrators yet is applicable to general nonconservative systems. We utilize a fixed-time-step variational integrator formalism applied to the principle of stationary nonconservative action developed in Galley et al. As a result, the generalized momenta and energy (Noether current) evolutions are well-tracked. We discuss several example systems, including damped harmonic oscillators, Poynting–Robertson drag, and gravitational radiation reaction, by utilizing our new publicly available code to demonstrate the slimplectic integrator algorithm. Slimplectic integrators are well-suited for integrations of systems where nonconservative effects play an important role in the long-term dynamical evolution. As such they are particularly appropriate for cosmological or celestial N-body dynamics problems where nonconservative interactions, e.g., gas interactions or dissipative tides, can play an important role.

  19. ALS Performance Summary - Update

    SciTech Connect

    Waters, A M; Brown, W D; Martz, Jr., H E

    2004-09-30

    High Energy Density Physics (HEDP) experiments play an important role in corroborating the improved physics codes that underlie LLNL's Stockpile Stewardship mission. Conducting these experiments, whether on the National Ignition Facility (NIF) or another national facility such as Omega, will require not only improvement in the diagnostics for measuring the experiment, but also detailed knowledge of the as-built target components and assemblies themselves. To assist in this effort, a defined set of well-known reference standards designed to represent a range of HEDP targets have been built and are being used to quantify the performance of different characterization techniques [Hibbard, et al. 2004]. Without the critical step of using reference standards for qualifying characterization tools there can be no verification of either commercial or internally-developed characterization techniques and thus an uncertainty in the input to the physics code models would exist.

  20. Integrative psychotherapy.

    PubMed

    Kozarić-Kovacić, Dragica

    2008-09-01

    The main purposes of the article are to present the history of integration in psychotherapy, the reasons of the development integrative approaches, and the approaches to integration in psychotherapy. Three approaches to integration in psychotherapy exist: theoretical integration, theoretical eclecticism, and common factors in different psychotherapeutic trends. In integrative psychotherapy, the basic epistemology, theory, and clinical practice are based on the phenomenology, field theory, holism, dialogue, and co-creation of dialogue in the therapeutic relationship. The main criticism is that integrative psychotherapy suffers from confusion and many unresolved controversies. It is difficult to theoretically and methodologically define the clinically applied model that is based on such a different epistemological and theoretical presumptions. Integrative psychotherapy is a synthesis of humanistic psychotherapy, object relations theory, and psychoanalytical self psychology. It focuses on the dynamics and potentials of human relationships, with a goal of changing the relations and understanding internal and external resistances. The process of integrative psychotherapy is primarily focused on the developmental-relational model and co-creation of psychotherapeutic relationship as a single interactive event, which is not unilateral, but rather a joint endeavor by both the therapist and the patient/client. The need for a relationship is an important human need and represents a process of attunement that occurs as a response to the need for a relationship, a unique interpersonal contact between two people. If this need is not met, it manifests with the different feelings and various defenses. To meet this need, we need to have another person with whom we can establish a sensitive, attuned relationship. Thus, the therapist becomes this person who tries to supplement what the person did not receive. Neuroscience can be a source of integration through different therapies. We

  1. Cryptanalysis and improvement of Yan et al.'s biometric-based authentication scheme for telecare medicine information systems.

    PubMed

    Mishra, Dheerendra; Mukhopadhyay, Sourav; Chaturvedi, Ankita; Kumari, Saru; Khan, Muhammad Khurram

    2014-06-01

    Remote user authentication is desirable for a Telecare Medicine Information System (TMIS) for the safety, security and integrity of transmitted data over the public channel. In 2013, Tan presented a biometric based remote user authentication scheme and claimed that his scheme is secure. Recently, Yan et al. demonstrated some drawbacks in Tan's scheme and proposed an improved scheme to erase the drawbacks of Tan's scheme. We analyze Yan et al.'s scheme and identify that their scheme is vulnerable to off-line password guessing attack, and does not protect anonymity. Moreover, in their scheme, login and password change phases are inefficient to identify the correctness of input where inefficiency in password change phase can cause denial of service attack. Further, we design an improved scheme for TMIS with the aim to eliminate the drawbacks of Yan et al.'s scheme. PMID:24880932

  2. Theoretical studies of AlF, AlCl, and AlBr

    NASA Technical Reports Server (NTRS)

    Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Taylor, Peter R.

    1988-01-01

    Spectroscopic constants have been obtained for the lowest six singlet and lowest five triplet states of AlF and AlCl. The results suggest that the correct ordering of the triplet manifold in these molecules is: a 3Pi, b 3Sigma(+), c 3Sigma(+), d 3Pi, and e 3Delta. Radiative lifetimes have been determined for the excited states, and the A 1Pi to X 1Sigma(+) transition in AlF, AlCl, and AlBr has been examined in detail. A-X transition moment functions, Einstein coefficients, and A 1Pi vibrational lifetimes have been obtained for AlF and AlCl.

  3. Functional Integration

    NASA Astrophysics Data System (ADS)

    Cartier, Pierre; DeWitt-Morette, Cecile

    2010-06-01

    Acknowledgements; List symbols, conventions, and formulary; Part I. The Physical and Mathematical Environment: 1. The physical and mathematical environment; Part II. Quantum Mechanics: 2. First lesson: gaussian integrals; 3. Selected examples; 4. Semiclassical expansion: WKB; 5. Semiclassical expansion: beyond WKB; 6. Quantum dynamics: path integrals and operator formalism; Part III. Methods from Differential Geometry: 7. Symmetries; 8. Homotopy; 9. Grassmann analysis: basics; 10. Grassmann analysis: applications; 11. Volume elements, divergences, gradients; Part IV. Non-Gaussian Applications: 12. Poisson processes in physics; 13. A mathematical theory of Poisson processes; 14. First exit time: energy problems; Part V. Problems in Quantum Field Theory: 15. Renormalization 1: an introduction; 16. Renormalization 2: scaling; 17. Renormalization 3: combinatorics; 18. Volume elements in quantum field theory Bryce DeWitt; Part VI. Projects: 19. Projects; Appendix A. Forward and backward integrals: spaces of pointed paths; Appendix B. Product integrals; Appendix C. A compendium of gaussian integrals; Appendix D. Wick calculus Alexander Wurm; Appendix E. The Jacobi operator; Appendix F. Change of variables of integration; Appendix G. Analytic properties of covariances; Appendix H. Feynman's checkerboard; Bibliography; Index.

  4. Functional Integration

    NASA Astrophysics Data System (ADS)

    Cartier, Pierre; DeWitt-Morette, Cecile

    2006-11-01

    Acknowledgements; List symbols, conventions, and formulary; Part I. The Physical and Mathematical Environment: 1. The physical and mathematical environment; Part II. Quantum Mechanics: 2. First lesson: gaussian integrals; 3. Selected examples; 4. Semiclassical expansion: WKB; 5. Semiclassical expansion: beyond WKB; 6. Quantum dynamics: path integrals and operator formalism; Part III. Methods from Differential Geometry: 7. Symmetries; 8. Homotopy; 9. Grassmann analysis: basics; 10. Grassmann analysis: applications; 11. Volume elements, divergences, gradients; Part IV. Non-Gaussian Applications: 12. Poisson processes in physics; 13. A mathematical theory of Poisson processes; 14. First exit time: energy problems; Part V. Problems in Quantum Field Theory: 15. Renormalization 1: an introduction; 16. Renormalization 2: scaling; 17. Renormalization 3: combinatorics; 18. Volume elements in quantum field theory Bryce DeWitt; Part VI. Projects: 19. Projects; Appendix A. Forward and backward integrals: spaces of pointed paths; Appendix B. Product integrals; Appendix C. A compendium of gaussian integrals; Appendix D. Wick calculus Alexander Wurm; Appendix E. The Jacobi operator; Appendix F. Change of variables of integration; Appendix G. Analytic properties of covariances; Appendix H. Feynman's checkerboard; Bibliography; Index.

  5. Integrative neuroscience.

    PubMed

    Gordon, Evian

    2003-07-01

    A fundamental impediment to an "Integrative Neuroscience" is the sense that scientists building models at one particular scale often see that scale as the epicentre of all brain function. This fragmentation has begun to change in a very distinctive way. Multidisciplinary efforts have provided the impetus to break down the boundaries and encourage a freer exchange of information across disciplines and scales. Despite huge deficits of knowledge, sufficient facts about the brain already exist, for an Integrative Neuroscience to begin to lift us clear of the jungle of detail, and shed light upon the workings of the brain as a system. Integrations of brain theory can be tested using judicious paradigm designs and measurement of temporospatial activity reflected in brain imaging technologies. However, to test realistically these new hypotheses requires consistent findings of the normative variability in very large numbers of control subjects, coupled with high sensitivity and specificity of findings in psychiatric disorders. Most importantly, these findings need to be analyzed and modeled with respect to the fundamental mechanisms underlying these measures. Without this convergence of theory, databases, and methodology (including across scale physiologically realistic numerical models), the clinical utility of brain imaging technologies in psychiatry will be significantly impeded. The examples provided in this paper of integration of theory, temporospatial integration of neuroimaging technologies, and a numerical simulation of brain function, bear testimony to the ongoing conversion of an Integrative Neuroscience from an exemplar status into reality.

  6. Integrated optic ammonia sensor

    NASA Astrophysics Data System (ADS)

    Klein, Rainer; Voges, Edgar I.

    1993-05-01

    Most of the disadvantages that exist with electrochemical devices (e.g., short lifetimes, difficult to miniaturize, need of reference electrodes) can be avoided by using optical sensors. Smock et al. describe a device incorporating a ninhydrin coated fused silica rod that could detect ammonia vapor at concentrations below 100 ppb, however, the reaction is irreversible. Guiliani et al. describe a reversible sensor using a dye coated capillary tube. The dye utilized is oxazine perchlorate, a laser dye. They report that the presence of water vapor is an important factor in the detection of ammonia, and the concentration of water vapor must be controlled. Optical sensors built-up in integrated-optic technique with planar waveguide configurations allow the construction of optical sensor systems for a parallel detection of several chemical species, provide the generation of reference signals, and facilitate the problem of cross-sensitivities. Here, we report on integrated-optic sensors for ammonia detection with a sensitivity in the ppb-range. The reaction is reversible, and the response is independent of the water vapor concentration in the test gas.

  7. Species integrity in trees.

    PubMed

    Ortiz-Barrientos, Daniel; Baack, Eric J

    2014-09-01

    From California sequoia, to Australian eucalyptus, to the outstanding diversity of Amazonian forests, trees are fundamental to many processes in ecology and evolution. Trees define the communities that they inhabit, are host to a multiplicity of other organisms and can determine the ecological dynamics of other plants and animals. Trees are also at the heart of major patterns of biodiversity such as the latitudinal gradient of species diversity and thus are important systems for studying the origin of new plant species. Although the role of trees in community assembly and ecological succession is partially understood, the origin of tree diversity remains largely opaque. For instance, the relative importance of differing habitats and phenologies as barriers to hybridization between closely related species is still largely uncharacterized in trees. Consequently, we know very little about the origin of trees species and their integrity. Similarly, studies on the interplay between speciation and tree community assembly are in their infancy and so are studies on how processes like forest maturation modifies the context in which reproductive isolation evolves. In this issue of Molecular Ecology, Lindtke et al. (2014) and Lagache et al. (2014) overcome some traditional difficulties in studying mating systems and sexual isolation in the iconic oaks and poplars, providing novel insights about the integrity of tree species and on how ecology leads to variation in selection on reproductive isolation over time and space. PMID:25155715

  8. Exploring Essential Conditions: A Commentary on Bull et al. (2008)

    ERIC Educational Resources Information Center

    Borthwick, Arlene; Hansen, Randall; Gray, Lucy; Ziemann, Irina

    2008-01-01

    The editorial by Bull et al. (2008) on connections between informal and formal learning made explicit one element of solving what Koehler and Mishra (2008) termed a "wicked problem." This wicked (complex, ill-structured) problem involves working with teachers for effective integration of technology in support of student learning. The…

  9. Calorimetric Measurements of Liquid Al-Zn Alloys

    NASA Astrophysics Data System (ADS)

    Dębski, Adam; Gąsior, Władysław; Szmit, Katarzyna

    2016-10-01

    The integral molar enthalpies of mixing were determined by the drop calorimetric method for binary AL-Zn liquid solutions and compared with the Miedema model as well as the earlier experimental data. The measurements were conducted at two temperatures: 957 K and 1001 K (684 °C and 728 °C), in the entire concentration range. Based on the experimental calorimetric data of this study as well as those available in the literature and the results of the activity studies, the interaction parameters of the Redlich-Kister equation for the liquid Al-Zn phase were worked out with the use of the least square method. The partial and integral Gibbs energies, entropies and enthalpies were calculated and presented in tables and figures. Additionally, the concentration-concentration partial structure factors for the ideal and real Al-Zn solutions were calculated and graphically presented.

  10. Alexandria (Al Iskandariya), Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

  11. Classical integrability

    NASA Astrophysics Data System (ADS)

    Torrielli, Alessandro

    2016-08-01

    We review some essential aspects of classically integrable systems. The detailed outline of the sections consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schrödinger model, principal chiral field); 4. Features of classical r-matrices: Belavin–Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel’fand–Levitan–Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  12. Classical integrability

    NASA Astrophysics Data System (ADS)

    Torrielli, Alessandro

    2016-08-01

    We review some essential aspects of classically integrable systems. The detailed outline of the sections consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schrödinger model, principal chiral field); 4. Features of classical r-matrices: Belavin-Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel’fand-Levitan-Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  13. The Integrated Hazard Analysis Integrator

    NASA Technical Reports Server (NTRS)

    Morris, A. Terry; Massie, Michael J.

    2009-01-01

    Hazard analysis addresses hazards that arise in the design, development, manufacturing, construction, facilities, transportation, operations and disposal activities associated with hardware, software, maintenance, operations and environments. An integrated hazard is an event or condition that is caused by or controlled by multiple systems, elements, or subsystems. Integrated hazard analysis (IHA) is especially daunting and ambitious for large, complex systems such as NASA s Constellation program which incorporates program, systems and element components that impact others (International Space Station, public, International Partners, etc.). An appropriate IHA should identify all hazards, causes, controls and verifications used to mitigate the risk of catastrophic loss of crew, vehicle and/or mission. Unfortunately, in the current age of increased technology dependence, there is the tendency to sometimes overlook the necessary and sufficient qualifications of the integrator, that is, the person/team that identifies the parts, analyzes the architectural structure, aligns the analysis with the program plan and then communicates/coordinates with large and small components, each contributing necessary hardware, software and/or information to prevent catastrophic loss. As viewed from both Challenger and Columbia accidents, lack of appropriate communication, management errors and lack of resources dedicated to safety were cited as major contributors to these fatalities. From the accident reports, it would appear that the organizational impact of managers, integrators and safety personnel contributes more significantly to mission success and mission failure than purely technological components. If this is so, then organizations who sincerely desire mission success must put as much effort in selecting managers and integrators as they do when designing the hardware, writing the software code and analyzing competitive proposals. This paper will discuss the necessary and

  14. Thermal Modeling of Al-Al and Al-Steel Friction Stir Spot Welding

    NASA Astrophysics Data System (ADS)

    Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.

    2016-07-01

    This paper presents a finite element thermal model for similar and dissimilar alloy friction stir spot welding (FSSW). The model is calibrated and validated using instrumented lap joints in Al-Al and Al-Fe automotive sheet alloys. The model successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-Fe welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.

  15. Thermal Modeling of Al-Al and Al-Steel Friction Stir Spot Welding

    NASA Astrophysics Data System (ADS)

    Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.

    2016-09-01

    This paper presents a finite element thermal model for similar and dissimilar alloy friction stir spot welding (FSSW). The model is calibrated and validated using instrumented lap joints in Al-Al and Al-Fe automotive sheet alloys. The model successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-Fe welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.

  16. Sheet gamma TiAl: Status and opportunities

    NASA Astrophysics Data System (ADS)

    Das, Gopal; Kestler, H.; Clemens, H.; Bartolotta, P. A.

    2004-11-01

    Gamma TiAl alloys have attractive properties such as low density, high-temperature strength, and high modulus, oxidation, and burn resistance. As a result, these alloys have the potential to replace heavier superalloys in aircraft engine components. Gamma TiAl alloys were investigated in the 1950s but were too brittle for thermo-mechanical processing. However, interest in this class of material rekindled with several U.S. aerospace programs: the National Aerospace Plane, the Integrated High Performance Turbine Engine Technology, and Enabling Propulsion Materials/High Speed Civil Transport, as well as German hypersonic technology programs. Intense metallurgical and metal processing research during the last two decades led to significant progress in this area. As a result, gamma TiAl alloys are now available in all conventional product forms: ingots, forgings, extrusions, and sheets. This article reviews the current status of sheet gamma TiAl technology and its future opportunities.

  17. Philosophieren als Unterrichtsprinzip im Mathematikunterricht

    NASA Astrophysics Data System (ADS)

    Meerwaldt, Diana

    Philosophieren und Mathematik scheinen zunächst gegensätzliche Bereiche zu sein, die sich kaum vereinbaren lassen. Dies trifft für eine Auffassung zu, die Philosophieren als "Gerede" disqualifiziert und Mathematik als eine reine "Formelwissenschaft" begreift. Beide Auffassungen werden den Gegenständen nicht gerecht.

  18. Imaging spectroscopy with Ta/Al DROIDs: Performance for different Al trapping layer thicknesses

    NASA Astrophysics Data System (ADS)

    Hijmering, R. A.; Verhoeve, P.; Martin, D. D. E.; Peacock, A.; Kozorezov, A. G.

    2006-04-01

    To overcome the limited field of view, which can be achieved with single superconducting tunneling junction (STJ) arrays, distributed read-out imaging devices (DROIDs) are being developed. DROIDs consist of a superconducting absorber strip with proximized STJs on either end. The ratio of the two signals from the STJs provides information on the absorption position, and the sum signal is a measure for the energy of the absorbed photon. In our devices, the absorber is an epitaxial Ta strip that extends underneath the Ta/Al read-out STJs. Thus, the bottom electrode of the STJs is an integral part of the absorber. Due to the proximity effect, the STJs have a lower energy gap than the absorber, causing trapping of quasiparticles (QPs) in the STJs. The trapping will change with thicker Al layers because the energy gap of the devices will decrease. A series of 50×200 μm 2 and 20×200 μm 2 absorbers (including 50×50 μm 2 STJs) and different Al trapping layer thicknesses, ranging from 65 to 130 nm, have been tested. The devices have been illuminated with 6 keV 55Fe photons. The position resolution is found to improve with increasing Al thickness. It is found that the current model needs to be adapted for DROIDs to account for different injection of QPs into the STJ and extra losses to the absorber.

  19. The Advanced Launch System (ALS)

    NASA Astrophysics Data System (ADS)

    Eldred, Charles H.

    The Advanced Launch System (ALS) is an unmanned vehicle that will achieve low hardware cost by using a reusable booster stage which flies back to the launch site, and a core stage in which the rocket engines and redundant avionics are in a module that is returned to earth and recovered for reuse. The booster's utilization of liquid propellant instead of solid propellant will help lower the consumable costs. The ALS also includes launch processing and flight control facilities, necessary support equipment, and ground- and flight-operations infrastructure. The ALS program studies show that, through the ALS, the United States can launch a major Mars initiative economically and with confidence. It is estimated that the objective ALS can be operational in the late 1990s.

  20. Information Integrity

    ERIC Educational Resources Information Center

    Graves, Eric

    2013-01-01

    This dissertation introduces the concept of Information Integrity, which is the detection and possible correction of information manipulation by any intermediary node in a communication system. As networks continue to grow in complexity, information theoretic security has failed to keep pace. As a result many parties whom want to communicate,…

  1. Numerical Integration

    ERIC Educational Resources Information Center

    Sozio, Gerry

    2009-01-01

    Senior secondary students cover numerical integration techniques in their mathematics courses. In particular, students would be familiar with the "midpoint rule," the elementary "trapezoidal rule" and "Simpson's rule." This article derives these techniques by methods which secondary students may not be familiar with and an approach that…

  2. Electronic states of Al and Al{sub 2} using quantum Monte Carlo with an effective core potential

    SciTech Connect

    Greeff, C.W.; Lester, W.A. Jr.; Hammond, B.L.

    1996-02-01

    The diffusion Monte Carlo method is applied in conjunction with an ab initio effective core potential to compute energies of some neutral and charged states of Al and Al{sub 2}. The computed ionization potentials, electron affinities and dissociation energies differ from measured values by at most a few hundredths of eV. The computed dissociation energy of Al{sub 2} agrees with the most extensive CI calculations. It appears that our dissociation energy for Al{sup {minus}}{sub 2} is the most accurate to date. The quality of the results indicates that the use of the pseudopotential is not an important limitation on the accuracy of these calculations. Variational wavefunctions with Boys-Handy correlation functions are found to give more than 70{percent} of the correlation energy with 8 optimized parameters. These optimized trial functions are used together with numerical integration to localize the pseudopotential. {copyright} {ital 1996 American Institute of Physics.}

  3. 26Al- 26Mg and 207Pb- 206Pb systematics of Allende CAIs: Canonical solar initial 26Al/ 27Al ratio reinstated

    NASA Astrophysics Data System (ADS)

    Jacobsen, Benjamin; Yin, Qing-zhu; Moynier, Frederic; Amelin, Yuri; Krot, Alexander N.; Nagashima, Kazuhide; Hutcheon, Ian D.; Palme, Herbert

    2008-07-01

    The precise knowledge of the initial 26Al/ 27Al ratio [( 26Al/ 27Al) 0] is crucial if we are to use the very first solid objects formed in our Solar System, calcium-aluminum-rich inclusions (CAIs) as the "time zero" age-anchor and guide future work with other short-lived radio-chronometers in the early Solar System, as well as determining the inventory of heat budgets from radioactivities for early planetary differentiation. New high-precision multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) measurements of 27Al/ 24Mg ratios and Mg-isotopic compositions of nine whole-rock CAIs (six mineralogically characterized fragments and three micro-drilled inclusions) from the CV carbonaceous chondrite, Allende yield a well-defined 26Al- 26Mg fossil isochron with an ( 26Al/ 27Al) 0 of (5.23 ± 0.13) × 10 - 5 . Internal mineral isochrons obtained for three of these CAIs ( A44A, AJEF, and A43) are consistent with the whole-rock CAI isochron. The mineral isochron of AJEF with ( 26Al/ 27Al) 0 = (4.96 ± 0.25) × 10 - 5 , anchored to our precisely determined absolute 207Pb- 206Pb age of 4567.60 ± 0.36 Ma for the same mineral separates, reinstate the "canonical" ( 26Al/ 27Al) 0 of 5 × 10 - 5 for the early Solar System. The uncertainty in ( 26Al/ 27Al) 0 corresponds to a maximum time span of ± 20 Ka (thousand years), suggesting that the Allende CAI formation events were culminated within this time span. Although all Allende CAIs studied experienced multistage formation history, including melting and evaporation in the solar nebula and post-crystallization alteration likely on the asteroidal parent body, the 26Al- 26Mg and U-Pb-isotopic systematics of the mineral separates and bulk CAIs behaved largely as closed-system since their formation. Our data do not support the "supra-canonical" 26Al/ 27Al ratio of individual minerals or their mixtures in CV CAIs, suggesting that the supra-canonical 26Al/ 27Al ratio in the CV CAIs may have resulted from post

  4. Quantum dots formed in InSb/AlAs and AlSb/AlAs heterostructures

    NASA Astrophysics Data System (ADS)

    Abramkin, D. S.; Rumynin, K. M.; Bakarov, A. K.; Kolotovkina, D. A.; Gutakovskii, A. K.; Shamirzaev, T. S.

    2016-06-01

    The crystal structure of new self-assembled InSb/AlAs and AlSb/AlAs quantum dots grown by molecularbeam epitaxy has been investigated by transmission electron microscopy. The theoretical calculations of the energy spectrum of the quantum dots have been supplemented by the experimental data on the steady-state and time-resolved photoluminescence spectroscopy. Deposition of 1.5 ML of InSb or AlSb on the AlAs surface carried out in the regime of atomic-layer epitaxy leads to the formation of pseudomorphically strained quantum dots composed of InAlSbAs and AlSbAs alloys, respectively. The quantum dots can have the type-I and type-II energy spectra depending on the composition of the alloy. The ground hole state in the quantum dot belongs to the heavy-hole band and the localization energy of holes is much higher than that of electrons. The ground electron state in the type-I quantum dots belongs to the indirect X XY valley of the conduction band of the alloy. The ground electron state in the type-II quantum dots belongs to the indirect X valley of the conduction band of the AlAs matrix.

  5. Near-infrared OPO in an AlGaAs/AlOx waveguide

    NASA Astrophysics Data System (ADS)

    Ozanam, C.; Savanier, M.; Lanco, L.; Lafosse, X.; Andronico, A.; Favero, I.; Ducci, S.; Leo, G.

    2013-12-01

    Within the ambitious quest for an electrically pumped version of the optical parametric oscillator (OPO), we demonstrate the first near-infrared integrated OPO in a direct gap semiconductor. This nonlinear device is based on a selectively oxidized GaAs/AlAs heterostructure, the same "AlOx" technology that is at the heart of VCSEL fabrication. The heterostructure and waveguide design allows for type-I form-birefringent phase matching, with a TM00 pump around 1 μm and TE00 signal and idler around 2 μm. Relying on the high non-resonant χ(2) of GaAs, relatively weak guided-wave optical losses, and monolithic SiO2/TiO2 dichroic Bragg mirrors, we observe a threshold of 210 mW at degeneracy in the continuous-wave regime, with a single-pass-pump doubly resonant scheme. Further improvement can be achieved by adopting a double-pump-pass scheme and, in a more fundamental way, by further optimizing the waveguide optical losses. The latter are induced by a not entirely mastered AlAs oxidation process and are of two distinct types: Rayleighlike scattering at signal and idler wavelength (α <= 1cm-1), due to the interface roughness between GaAs and AlOx layers; and absorption at pump wavelengths (α ≍ 3cm-1), due to volume defects in the GaAs layers adjacent to the aluminum oxide. This result marks a milestone for integrated nonlinear photonics and represents a significant step toward the goal of a broadly tunable coherent light source on chip.

  6. Integrating maps requires integrated data

    SciTech Connect

    Weissenbach, J.; Bentolila, S.

    1996-06-01

    The molecular genetics movement has proceeded admirably thanks to new technologies such as polymerase chain reaction (PCR) sequencing. However, the integration of mapping data has not yet been achieved. This article discussing several problem areas and serves as a reminder of the urgency of such concerns.

  7. Medical application of 26Al

    NASA Astrophysics Data System (ADS)

    Steinhausen, C.; Gerisch, P.; Heisinger, B.; Hohl, Ch.; Kislinger, G.; Korschinek, G.; Niedermayer, M.; Nolte, E.; Dumitru, M.; Alvarez-Brückmann, M.; Schneider, M.; Ittel, T. H.

    1996-06-01

    Accelerator mass spectrometry (AMS) measurements with 26Al as tracer were performed in order to study the aluminium metabolism and anomalies in the human body and in rats. In particular, the differences between healthy volunteers and patients with renal failure were investigated. The obtained data points of 26Al in blood and urine were described by an open compartment model with three peripheral compartments. It was found that the minimum of peripheral compartments needed to describe 26Al concentrations in blood and urine over a time period of three years is at least three.

  8. RADIATION INTEGRATOR

    DOEpatents

    Glass, F.M.; Wilson, H.N.

    1959-02-17

    Radiation detecting and measuring systems, particularly a compact, integrating, background monitor, are discussed. One of the principal features of the system is the use of an electrometer tube where the input of the tube is directly connected to an electrode of the radiation detector and a capacitor is coupled to the tube input. When a predetermined quantity of radiation has been integrated, a trigger signal is fed to a recorder and a charge is delivered to the capacitor to render the tube inoperative. The capacitor is then recharged for the next period of operation. With this arrangement there is a substantial reduction in lead lengths and the principal components may be enclosed and hermetically sealed to insure low leakage.

  9. Integrated Fluorescence

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret (Inventor); Gruhlke, Russell W. (Inventor)

    1998-01-01

    A detection method is integrated with a filtering method and an enhancement method to create a fluorescence sensor that can be miniaturized. The fluorescence sensor comprises a thin film geometry including a waveguide layer, a metal film layer and sensor layer. The thin film geometry of the fluorescence sensor allows the detection of fluorescent radiation over a narrow wavelength interval. This enables wavelength discrimination and eliminates the detection of unwanted light from unknown or spurious sources.

  10. Integrating Retinotopic Features in Spatiotopic Coordinates

    PubMed Central

    Bex, Peter J.

    2014-01-01

    The receptive fields of early visual neurons are anchored in retinotopic coordinates (Hubel and Wiesel, 1962). Eye movements shift these receptive fields and therefore require that different populations of neurons encode an object's constituent features across saccades. Whether feature groupings are preserved across successive fixations or processing starts anew with each fixation has been hotly debated (Melcher and Morrone, 2003; Melcher, 2005, 2010; Knapen et al., 2009; Cavanagh et al., 2010a,b; Morris et al., 2010). Here we show that feature integration initially occurs within retinotopic coordinates, but is then conserved within a spatiotopic coordinate frame independent of where the features fall on the retinas. With human observers, we first found that the relative timing of visual features plays a critical role in determining the spatial area over which features are grouped. We exploited this temporal dependence of feature integration to show that features co-occurring within 45 ms remain grouped across eye movements. Our results thus challenge purely feedforward models of feature integration (Pelli, 2008; Freeman and Simoncelli, 2011) that begin de novo after every eye movement, and implicate the involvement of brain areas beyond early visual cortex. The strong temporal dependence we quantify and its link with trans-saccadic object perception instead suggest that feature integration depends, at least in part, on feedback from higher brain areas (Mumford, 1992; Rao and Ballard, 1999; Di Lollo et al., 2000; Moore and Armstrong, 2003; Stanford et al., 2010). PMID:24849367

  11. In memory of Al Cameron

    NASA Astrophysics Data System (ADS)

    Cowan, John; Truran, James W.

    Al Cameron, who died recently (October 3, 2005) at 80, was one of the giants in astrophysics. His insights were profound and his interests were wide-ranging. Originally trained as a nuclear physicist, he made major contributions in a number of fields, including nuclear reactions in stars, nucleosynthesis, the abundances of the elements in the Solar System, and the origin of the Solar System and the Moon. In 1957, Cameron and, independently, Burbidge, Burbidge, Fowler and Hoyle, wrote seminal papers on nuclear astrophysics. Most of our current ideas concerning ele- ment formation in stars have followed from those two pioneering and historical works. Al also made many contributions in the field of Solar System physics. Particularly noteworthy in this regard was Cameron's work on the formation of the Moon. Al was also a good friend and mentor of young people. Al Cameron will be missed by many in the community both for his scientific contributions and for his friendship.

  12. Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s)

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2004-01-01

    In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made directly by Knudsen effusion-cell mass spectrometry with an instrument configured for a multiple effusion-cell vapor source (multi-cell KEMS). Second law enthalpies of vaporization of Al(g) and Al2O(g) together with activity measurements show that Al(l)+ZrO2(s) is thermodynamically equivalent to Al(l)+Al2O3(s), indicating Al(l) remained pure and Al2O3(s) was present in the ZrO2-cell. Subsequent observation of the Al(l)/ZrO2 and vapor/ZrO2 interfaces revealed a thin Al2O3-layer had formed, separating the ZrO2-cell from Al(l) and Al(g)+Al2O(g), effectively transforming it into an Al2O3 effusion-cell. This behavior agrees with recent observations made for Beta-NiAl(Pt) alloys measured in ZrO2 effusion-cell.

  13. ACCELERATION INTEGRATOR

    DOEpatents

    Pope, K.E.

    1958-01-01

    This patent relates to an improved acceleration integrator and more particularly to apparatus of this nature which is gyrostabilized. The device may be used to sense the attainment by an airborne vehicle of a predetermined velocitv or distance along a given vector path. In its broad aspects, the acceleration integrator utilizes a magnetized element rotatable driven by a synchronous motor and having a cylin drical flux gap and a restrained eddy- current drag cap deposed to move into the gap. The angular velocity imparted to the rotatable cap shaft is transmitted in a positive manner to the magnetized element through a servo feedback loop. The resultant angular velocity of tae cap is proportional to the acceleration of the housing in this manner and means may be used to measure the velocity and operate switches at a pre-set magnitude. To make the above-described dcvice sensitive to acceleration in only one direction the magnetized element forms the spinning inertia element of a free gyroscope, and the outer housing functions as a gimbal of a gyroscope.

  14. Ab initio modeling of zincblende AlN layer in Al-AlN-TiN multilayers

    NASA Astrophysics Data System (ADS)

    Yadav, S. K.; Wang, J.; Liu, X.-Y.

    2016-06-01

    An unusual growth mechanism of metastable zincblende AlN thin film by diffusion of nitrogen atoms into Al lattice is established. Using first-principles density functional theory, we studied the possibility of thermodynamic stability of AlN as a zincblende phase due to epitaxial strains and interface effect, which fails to explain the formation of zincblende AlN. We then compared the formation energetics of rocksalt and zincblende AlN in fcc Al through direct diffusion of nitrogen atoms to Al octahedral and tetrahedral interstitials. The formation of a zincblende AlN thin film is determined to be a kinetically driven process, not a thermodynamically driven process.

  15. Cultural Competence Integration in the Nursing Curriculum

    ERIC Educational Resources Information Center

    Stegman, Boniface C.

    2013-01-01

    With an increasingly diverse population, it is important to ensure that graduates of nursing programs are able to deliver culturally competent care (Krainovich-Miller et al., 2008; Allen, 2010). This study was undertaken to address this call to include cultural competence integration into nursing curriculum. The purpose of this study was to…

  16. Andalusian astronomy: al-Zij al-Muqtabis of Ibn al-Kammâd.

    NASA Astrophysics Data System (ADS)

    Chabás, J.; Goldstein, B. R.

    1994-12-01

    In the twelfth century the Arabic astronomer Ibn al-Kammâd, living in Islamic Spain, composed three sets of astronomical tables, called "zijes". The zijes were largely based on the work of predecessors, going back to Ptolemy on the one hand, and Hindu astronomers on the other. None of his zijes survived in the original Arabic, but a Latin manuscript contains a translation of an apparently complete zij, the "al-Zij al-Muqtabis". This paper examines the body of astronomical knowledge contained in this zij. Specifically, it is shown that one can gain valuable information on the solar theory of the Islamic astronomers from this translation. Furthermore, the theory of lunar and solar eclipses in the work is analyzed, and tables of mean planetary and solar motions are discussed. In addition, tables for the motion of the vernal equinox, star tables, and several topics of Islamic spherical astronomy are examined.

  17. Microstructure Evolution and Mechanical Properties of Al/Al-Mg/Al composite sheet metals

    NASA Astrophysics Data System (ADS)

    Cho, Jaehyung; Kim, Su-Hyeon; Kim, Hyoung-Wook; Lim, Cha-Yong; Kim, Eun-Young; Choi, Shi-Hoon

    2011-08-01

    Two different types of aluminum alloys of AA1050 and AA5182 were used to manufacture Al/Al-Mg/Al composite sheet metals by roll bonding technology at room temperature. The composite sheet metals were annealed at 400 °C and carried out uniaxial tension tests to investigate mechanical properties. Macroscopic mechanical properties are strongly dependent on the volume (or thickness) fraction of two component layers. Microstructure and texture evolution were also investigated during roll bonding process. The AA1050 sheets located in the outer layer mainly consist of shear texture components and the AA5182 sheet located in the center layer consists of plane strain texture components. With differential speeds of the top and bottom rolls, roll bonding was also carried out. Elongation along the RD and TD was improved at a speed difference of approximately 10%-20%.

  18. Dynamic Modeling of ALS Systems

    NASA Technical Reports Server (NTRS)

    Jones, Harry

    2002-01-01

    The purpose of dynamic modeling and simulation of Advanced Life Support (ALS) systems is to help design them. Static steady state systems analysis provides basic information and is necessary to guide dynamic modeling, but static analysis is not sufficient to design and compare systems. ALS systems must respond to external input variations and internal off-nominal behavior. Buffer sizing, resupply scheduling, failure response, and control system design are aspects of dynamic system design. We develop two dynamic mass flow models and use them in simulations to evaluate systems issues, optimize designs, and make system design trades. One model is of nitrogen leakage in the space station, the other is of a waste processor failure in a regenerative life support system. Most systems analyses are concerned with optimizing the cost/benefit of a system at its nominal steady-state operating point. ALS analysis must go beyond the static steady state to include dynamic system design. All life support systems exhibit behavior that varies over time. ALS systems must respond to equipment operating cycles, repair schedules, and occasional off-nominal behavior or malfunctions. Biological components, such as bioreactors, composters, and food plant growth chambers, usually have operating cycles or other complex time behavior. Buffer sizes, material stocks, and resupply rates determine dynamic system behavior and directly affect system mass and cost. Dynamic simulation is needed to avoid the extremes of costly over-design of buffers and material reserves or system failure due to insufficient buffers and lack of stored material.

  19. Nonplanar integrability

    NASA Astrophysics Data System (ADS)

    Carlson, Warren; de Mello Koch, Robert; Lin, Hai

    2011-03-01

    In this article we study operators with a dimension Δ ˜ O( N) and show that simple analytic expressions for the action of the dilatation operator can be found. The operators we consider are restricted Schur polynomials. There are two distinct classes of operators that we consider: operators labeled by Young diagrams with two long columns or two long rows. The main complication in working with restricted Schur polynomials is in building a projector from a given S n+ m irreducible representation to an S n × S m irreducible representation (both specified by the labels of the restricted Schur polynomial). We give an explicit construction of these projectors by reducing it to the simple problem of addition of angular momentum in ordinary non-relativistic quantum mechanics. The diagonalization of the dilatation operator reduces to solving three term recursion relations. The fact that the recursion relations have only three terms is a direct consequence of the weak mixing at one loop of the restricted Schur polynomials. The recursion relations can be solved exactly in terms of symmetric Kravchuk polynomials or in terms of Clebsch-Gordan coefficients. This proves that the dilatation operator reduces to a decoupled set of harmonic oscillators and therefore it is integrable.

  20. Emission mechanisms in Al-rich AlGaN/AlN quantum wells assessed by excitation power dependent photoluminescence spectroscopy

    SciTech Connect

    Iwata, Yoshiya; Banal, Ryan G.; Ichikawa, Shuhei; Funato, Mitsuru; Kawakami, Yoichi

    2015-02-21

    The optical properties of Al-rich AlGaN/AlN quantum wells are assessed by excitation-power-dependent time-integrated (TI) and time-resolved (TR) photoluminescence (PL) measurements. Two excitation sources, an optical parametric oscillator and the 4th harmonics of a Ti:sapphire laser, realize a wide range of excited carrier densities between 10{sup 12} and 10{sup 21 }cm{sup −3}. The emission mechanisms change from an exciton to an electron-hole plasma as the excitation power increases. Accordingly, the PL decay time is drastically reduced, and the integrated PL intensities increase in the following order: linearly, super-linearly, linearly again, and sub-linearly. The observed results are well accounted for by rate equations that consider the saturation effect of non-radiative recombination processes. Using both TIPL and TRPL measurements allows the density of non-radiative recombination centers, the internal quantum efficiency, and the radiative recombination coefficient to be reliably extracted.

  1. Response to Pagano et al.

    PubMed

    Rezende, Flávia; Löwe, Oliver; Helfinger, Valeska; Prior, Kim-Kristin; Walter, Maria; Zukunft, Sven; Fleming, Ingrid; Weissmann, Norbert; Brandes, Ralf P; Schröder, Katrin

    2015-11-20

    In their letter, Pagano et al. appreciate the development of the Nox1, Nox2, and Nox4 triple (3N(-/-)) knockout mouse. They also agree on the view that chemiluminescence assays in general have severe limitations. However, they criticize the fact that the membrane assays in the particular study were restricted to chemiluminescence techniques. Moreover, Pagano et al. got the impression that statements concerning membrane assays of Nox activity in general were made. In addition to a lack of some technical details, Pagano et al. also found the characterization of the 3N(-/-) incomplete and some of the results to be incomprehensible. Although we are grateful for the interest of Pagano et al. in our work, we realized that basically each observation of our study was questioned. This is certainly an excessive rejection of the study in total and fails to appreciate the clear chain of evidences presented. Our work focused on chemiluminescence, and thus, any conclusions are restricted to this technique. Moreover, the 3N(-/-) mice were never developed to study the physiology of Nox enzymes, but rather to validate Nox specificity of NADPH-stimulated chemiluminescence assays. We are convinced that our findings are a valid demonstration that chemiluminescence-based assays in membrane preparations stimulated with NADPH do not measure Nox activity. This conclusion is based on both overexpression studies as well as genetic deficient mouse models. The criticisms of Pagano et al. thus might be justified in some aspects; they, however, cannot disprove the conclusions of our work. Antioxid. Redox Signal. 23, 1247-1249.

  2. Response to Pagano et al.

    PubMed

    Rezende, Flávia; Löwe, Oliver; Helfinger, Valeska; Prior, Kim-Kristin; Walter, Maria; Zukunft, Sven; Fleming, Ingrid; Weissmann, Norbert; Brandes, Ralf P; Schröder, Katrin

    2015-11-20

    In their letter, Pagano et al. appreciate the development of the Nox1, Nox2, and Nox4 triple (3N(-/-)) knockout mouse. They also agree on the view that chemiluminescence assays in general have severe limitations. However, they criticize the fact that the membrane assays in the particular study were restricted to chemiluminescence techniques. Moreover, Pagano et al. got the impression that statements concerning membrane assays of Nox activity in general were made. In addition to a lack of some technical details, Pagano et al. also found the characterization of the 3N(-/-) incomplete and some of the results to be incomprehensible. Although we are grateful for the interest of Pagano et al. in our work, we realized that basically each observation of our study was questioned. This is certainly an excessive rejection of the study in total and fails to appreciate the clear chain of evidences presented. Our work focused on chemiluminescence, and thus, any conclusions are restricted to this technique. Moreover, the 3N(-/-) mice were never developed to study the physiology of Nox enzymes, but rather to validate Nox specificity of NADPH-stimulated chemiluminescence assays. We are convinced that our findings are a valid demonstration that chemiluminescence-based assays in membrane preparations stimulated with NADPH do not measure Nox activity. This conclusion is based on both overexpression studies as well as genetic deficient mouse models. The criticisms of Pagano et al. thus might be justified in some aspects; they, however, cannot disprove the conclusions of our work. Antioxid. Redox Signal. 23, 1247-1249. PMID:26173053

  3. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

    PubMed

    Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

    2015-09-21

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

  4. Thermodynamic modeling of Pt-Al and Pd-Al

    NASA Astrophysics Data System (ADS)

    Carr, Derek

    2011-03-01

    Pure platinum and pure palladium are too soft for typical jewelry applications. Adding small amounts of other metals can significantly increase their performance. However, international hallmarking standards require the alloys to be 95% pure by weight. How does one achieve significant improvements in performance adding only small amounts (5 wt-%) of other metals? Significant improvements are possible even with small additions if precipitate hardening can be induced. Using a combination of first-principles, cluster expansion, and Monte Carlo modeling, we have identified new Pt-rich/Pd-rich phases in Pt-Al and Pd-Al that should be useful in precipitate hardening. Thermodynamical modeling indicates that the phases are experimentally feasible (not kinetically inhibited).

  5. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

    2015-09-01

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

  6. Path-integral approach to 't Hooft's derivation of quantum physics from classical physics

    SciTech Connect

    Blasone, Massimo; Jizba, Petr; Kleinert, Hagen

    2005-05-15

    We present a path-integral formulation of 't Hooft's derivation of quantum physics from classical physics. The crucial ingredient of this formulation is Gozzi et al.'s supersymmetric path integral of classical mechanics. We quantize explicitly two simple classical systems: the planar mathematical pendulum and the Roessler dynamical system.

  7. Optoelectronic properties of novel amorphous CuAlO2/ZnO NWs based heterojunction

    NASA Astrophysics Data System (ADS)

    Bu, Ian Y. Y.

    2013-08-01

    Amorphous p-type CuAlO2 thin films were grown onto n-type crystalline ZnO NWs forming a heterojunction through the combination of sol-gel process and hydrothermal growth method. The effects of temperature on structure and optoelectronic properties of CuAlO2 thin films were investigated through various measurement techniques. It was found that the derived CuAlO2 is Al-rich with thin film. UV-Vis measurements showed that the deposited CuAlO2 films are semi-transparent with maximum transmittance ∼82% at 500 nm. Electrical characterization and integration into pn junction confirms that the amorphous CuAlO2 is p-type and exhibited photovoltaic behavior.

  8. AlSb/InAs/AlSb quantum wells

    NASA Technical Reports Server (NTRS)

    Kroemer, Herbert

    1990-01-01

    Researchers studied the InAs/AlSb system recently, obtaining 12nm wide quantum wells with room temperature mobilities up to 28,000 cm(exp 2)/V center dot S and low-temperature mobilities up to 325,000 cm(exp 2)/V center dot S, both at high electron sheet concentrations in the 10(exp 12)/cm(exp 2) range (corresponding to volume concentrations in the 10(exp 18)/cm(exp 2) range). These wells were not intentionally doped; the combination of high carrier concentrations and high mobilities suggest that the electrons are due to not-intentional modulation doping by an unknown donor in the AlSb barriers, presumably a stoichiometric defect, like an antisite donor. Inasmuch as not intentionally doped bulk AlSb is semi-insulating, the donor must be a deep one, being ionized only by draining into the even deeper InAs quantum well. The excellent transport properties are confirmed by other observations, like excellent quantum Hall effect data, and the successful use of the quantum wells as superconductive weak links between Nb electrodes, with unprecendentedly high critical current densities. The system is promising for future field effect transistors (FETs), but many processing problems must first be solved. Although the researchers have achieved FETs, the results so far have not been competitive with GaAs FETs.

  9. Identification of Candida albicans ALS2 and ALS4 and Localization of Als Proteins to the Fungal Cell Surface

    PubMed Central

    Hoyer, L. L.; Payne, T. L.; Hecht, J. E.

    1998-01-01

    Additional genes in the growing ALS family of Candida albicans were isolated by PCR screening of a genomic fosmid library with primers designed from the consensus tandem-repeat sequence of ALS1. This procedure yielded fosmids encoding ALS2 and ALS4. ALS2 and ALS4 conformed to the three-domain structure of ALS genes, which consists of a central domain of tandemly repeated copies of a 108-bp motif, an upstream domain of highly conserved sequences, and a domain of divergent sequences 3′ of the tandem repeats. Alignment of five predicted Als protein sequences indicated conservation of N- and C-terminal hydrophobic regions which have the hallmarks of secretory signal sequences and glycosylphosphatidylinositol addition sites, respectively. Heterologous expression of an N-terminal fragment of Als1p in Saccharomyces cerevisiae demonstrated function of the putative signal sequence with cleavage following Ala17. This signal sequence cleavage site was conserved in the four other Als proteins analyzed, suggesting identical processing of each protein. Primary-structure features of the five Als proteins suggested a cell-surface localization, which was confirmed by indirect immunofluorescence with an anti-Als antiserum. Staining was observed on mother yeasts and germ tubes, although the intensity of staining on the mother yeast decreased with elongation of the germ tube. Similar to other ALS genes, ALS2 and ALS4 were differentially regulated. ALS4 expression was correlated with the growth phase of the culture; ALS2 expression was not observed under many different in vitro growth conditions. The data presented here demonstrate that ALS genes encode cell-surface proteins and support the conclusion that the size and number of Als proteins on the C. albicans cell surface vary with strain and growth conditions. PMID:9765564

  10. Dysregulated miRNA biogenesis downstream of cellular stress and ALS-causing mutations: a new mechanism for ALS.

    PubMed

    Emde, Anna; Eitan, Chen; Liou, Lee-Loung; Libby, Ryan T; Rivkin, Natali; Magen, Iddo; Reichenstein, Irit; Oppenheim, Hagar; Eilam, Raya; Silvestroni, Aurelio; Alajajian, Betty; Ben-Dov, Iddo Z; Aebischer, Julianne; Savidor, Alon; Levin, Yishai; Sons, Robert; Hammond, Scott M; Ravits, John M; Möller, Thomas; Hornstein, Eran

    2015-11-01

    Interest in RNA dysfunction in amyotrophic lateral sclerosis (ALS) recently aroused upon discovering causative mutations in RNA-binding protein genes. Here, we show that extensive down-regulation of miRNA levels is a common molecular denominator for multiple forms of human ALS. We further demonstrate that pathogenic ALS-causing mutations are sufficient to inhibit miRNA biogenesis at the Dicing step. Abnormalities of the stress response are involved in the pathogenesis of neurodegeneration, including ALS. Accordingly, we describe a novel mechanism for modulating microRNA biogenesis under stress, involving stress granule formation and re-organization of DICER and AGO2 protein interactions with their partners. In line with this observation, enhancing DICER activity by a small molecule, enoxacin, is beneficial for neuromuscular function in two independent ALS mouse models. Characterizing miRNA biogenesis downstream of the stress response ties seemingly disparate pathways in neurodegeneration and further suggests that DICER and miRNAs affect neuronal integrity and are possible therapeutic targets.

  11. Elliptic integrals: Symmetry and symbolic integration

    SciTech Connect

    Carlson, B.C. |

    1997-12-31

    Computation of elliptic integrals, whether numerical or symbolic, has been aided by the contributions of Italian mathematicians. Tricomi had a strong interest in iterative algorithms for computing elliptic integrals and other special functions, and his writings on elliptic functions and elliptic integrals have taught these subjects to many modern readers (including the author). The theory of elliptic integrals began with Fagnano`s duplication theorem, a generalization of which is now used iteratively for numerical computation in major software libraries. One of Lauricella`s multivariate hypergeometric functions has been found to contain all elliptic integrals as special cases and has led to the introduction of symmetric canonical forms. These forms provide major economies in new integral tables and offer a significant advantage also for symbolic integration of elliptic integrals. Although partly expository the present paper includes some new proofs and proposes a new procedure for symbolic integration.

  12. Al-Anon and recovery.

    PubMed

    Cermak, T L

    1989-01-01

    The history of Al-Anon and its current demographics are reviewed. In order to understand 12-step recovery and psychotherapy for family members of alcoholics, the concept of codependence is defined with a set of diagnostic criteria consistent with the DSM-III-R definition of personality traits and disorders. At the core of codependence are denial and an unrealistic relationship to willpower. The therapeutic implications of considering codependence as a personality disorder are explored, as are the characteristics that make codependence unique among personality disorders: the central role of denial and the existence of a self-help organization to facilitate recovery. The dynamics of working the 12 steps on codependent characteristics are outlined. A synergistic relationship between psychotherapy and the 12 steps is described. Special attention is given the emergence of Al-Anon adult children of alcoholic meetings, and the future of codependence is discussed.

  13. Emerging mechanisms of molecular pathology in ALS.

    PubMed

    Peters, Owen M; Ghasemi, Mehdi; Brown, Robert H

    2015-05-01

    Amyotrophic lateral sclerosis (ALS) is a devastating degenerative disease characterized by progressive loss of motor neurons in the motor cortex, brainstem, and spinal cord. Although defined as a motor disorder, ALS can arise concurrently with frontotemporal lobal dementia (FTLD). ALS begins focally but disseminates to cause paralysis and death. About 10% of ALS cases are caused by gene mutations, and more than 40 ALS-associated genes have been identified. While important questions about the biology of this disease remain unanswered, investigations of ALS genes have delineated pathogenic roles for (a) perturbations in protein stability and degradation, (b) altered homeostasis of critical RNA- and DNA-binding proteins, (c) impaired cytoskeleton function, and (d) non-neuronal cells as modifiers of the ALS phenotype. The rapidity of progress in ALS genetics and the subsequent acquisition of insights into the molecular biology of these genes provide grounds for optimism that meaningful therapies for ALS are attainable. PMID:25932674

  14. Synthesis of AlN/Al Polycrystals along with Al Nanoparticles Using Thermal Plasma Route

    SciTech Connect

    Kanhe, Nilesh S.; Nawale, A. B.; Kulkarni, N. V.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2011-07-15

    This paper for the first time reports the (200) oriented growth of hexagonal Aluminum nitride crystals during synthesis of aluminum nanoparticles in dc transferred arc thermal plasma reactor by gas phase condensation in nitrogen plasma. The structural and morphological study of as synthesized AlN crystal and aluminium nanoparticles was done by using the x-ray diffraction method, scanning electron microscopy and transmission electron microscopy.

  15. Ab initio modeling of zincblende AlN layer in Al-AlN-TiN multilayers

    DOE PAGES

    Yadav, S. K.; Wang, J.; Liu, X. -Y.

    2016-06-13

    An unusual growth mechanism of metastable zincblende AlN thin film by diffusion of nitrogen atoms into Al lattice is established. Using first-principles density functional theory, we studied the possibility of thermodynamic stability of AlN as a zincblende phase due to epitaxial strains and interface effect, which fails to explain the formation of zincblende AlN. We then compared the formation energetics of rocksalt and zincblende AlN in fcc Al through direct diffusion of nitrogen atoms to Al octahedral and tetrahedral interstitials. Furthermore, the formation of a zincblende AlN thin film is determined to be a kinetically driven process, not a thermodynamicallymore » driven process.« less

  16. Evaluating Simultaneous Integrals

    ERIC Educational Resources Information Center

    Kwong, Harris

    2012-01-01

    Many integrals require two successive applications of integration by parts. During the process, another integral of similar type is often invoked. We propose a method which can integrate these two integrals simultaneously. All we need is to solve a linear system of equations.

  17. Testing and tuning symplectic integrators for the hybrid Monte Carlo algorithm in lattice QCD

    SciTech Connect

    Takaishi, Tetsuya; Forcrand, Philippe de

    2006-03-15

    We examine a new second-order integrator recently found by Omelyan et al. The integration error of the new integrator measured in the root mean square of the energy difference, <{delta}H{sup 2}>{sup 1/2}, is about 10 times smaller than that of the standard second-order leapfrog (2LF) integrator. As a result, the step size of the new integrator can be made about three times larger. Taking into account a factor 2 increase in cost, the new integrator is about 50% more efficient than the 2LF integrator. Integrating over positions first, then momenta, is slightly more advantageous than the reverse. Further parameter tuning is possible. We find that the optimal parameter for the new integrator is slightly different from the value obtained by Omelyan et al., and depends on the simulation parameters. This integrator could also be advantageous for the Trotter-Suzuki decomposition in quantum Monte Carlo.

  18. Synthesis of Al-Al2O3 and Al-Aln Nanoparticle Composites Via Electric Explosion of Wires

    NASA Astrophysics Data System (ADS)

    Lerner, M. I.; Lozhkomoev, A. S.; Pervikov, A. V.; Bakina, O. V.

    2016-07-01

    Composite Al-Al2O3 and Al-AlN nanoparticles were synthesized via electric explosion of aluminum wires in an argon-oxygen gas mixture and in nitrogen. The parameters of electric explosion and gas medium affect the size and relative content of nitride and aluminum oxide in the nanoparticles. Processes of forming chemical compounds during aluminum oxidation at the contact surface between explosive products and gas and of nitrogen diffusions into the nanoparticles of the condensed phase are considered.

  19. NiAl-base composite containing high volume fraction of AlN for advanced engines

    NASA Technical Reports Server (NTRS)

    Hebsur, Mohan (Inventor); Whittenbeger, John D. (Inventor); Lowell, Carl F. (Inventor)

    1994-01-01

    A particulate reinforced NiAl-AlN composite alloy has a NiAl matrix and greater than about 13 volume percent fine particles of AlN within the matrix. The particles preferably have a diameter from about 15 nanometers to about 50 nanometers. The particulate reinforced NiAl-AlN composite alloy may be prepared by cryomilling prealloyed NiAl in liquid nitrogen using grinding media having a diameter of from about 2 to 6 mm at an impeller speed of from about 450 RPM to about 800 RPM. The cryomilling may be done for a duration of from about 4 hours to about 20 hours to obtain a cryomilled powder. The cryomilled powder may be consolidated to form the particulate reinforced NiAl-AlN composite alloy. The particulate reinforced alloy can further include a toughening alloy. The toughening alloy may include NiCrAlY, FeCrAlY, and FeAl.

  20. Reply to Pachai et al.

    PubMed

    Harrison, William J; Bex, Peter J

    2016-05-01

    Peripheral vision is fundamentally limited by the spacing between objects. When asked to report a target's identity, observers make erroneous reports that sometimes match the identity of a nearby distractor and sometimes match a combination of target and distractor features. The classification of these errors has previously been used to support competing 'substitution' [1] or 'averaging' [2] models of the phenomenon known as 'visual crowding'. We recently proposed a single model in which both classes of error occur because observers make their reports by sampling from a biologically-plausible population of weighted responses within a region of space around the target [3]. It is critical to note that there is no probabilistic substitution or averaging process in our model; instead, we argue that neither substitution nor averaging occur, but that these are misclassifications of the distribution of reports that emerge when a population response distribution is sampled. This is a fundamentally different way of thinking about crowding, and on this basis we claim to have provided a mechanism unifying categorically distinct perceptual errors. Our goal was not to model all crowding phenomena, such as the release from crowding when target and flanks differ in color or depth [4]. Pachai et al.[5] have suggested that our model is not unifying because it inaccurately predicts perceptual performance for a particular stimulus. Although we agree that our model does not predict their data, this specific demonstration overlooks the critical aspect of the model: perceptual reports are drawn from a weighted population code. We show that Pachai et al.'s [5] own data actually provide evidence for the population code we have described [3], and we suggest a biologically-plausible analysis of their stimuli that provides a computational basis for their 'grouping' account of crowding. PMID:27166690

  1. Reply to Pachai et al.

    PubMed

    Harrison, William J; Bex, Peter J

    2016-05-01

    Peripheral vision is fundamentally limited by the spacing between objects. When asked to report a target's identity, observers make erroneous reports that sometimes match the identity of a nearby distractor and sometimes match a combination of target and distractor features. The classification of these errors has previously been used to support competing 'substitution' [1] or 'averaging' [2] models of the phenomenon known as 'visual crowding'. We recently proposed a single model in which both classes of error occur because observers make their reports by sampling from a biologically-plausible population of weighted responses within a region of space around the target [3]. It is critical to note that there is no probabilistic substitution or averaging process in our model; instead, we argue that neither substitution nor averaging occur, but that these are misclassifications of the distribution of reports that emerge when a population response distribution is sampled. This is a fundamentally different way of thinking about crowding, and on this basis we claim to have provided a mechanism unifying categorically distinct perceptual errors. Our goal was not to model all crowding phenomena, such as the release from crowding when target and flanks differ in color or depth [4]. Pachai et al.[5] have suggested that our model is not unifying because it inaccurately predicts perceptual performance for a particular stimulus. Although we agree that our model does not predict their data, this specific demonstration overlooks the critical aspect of the model: perceptual reports are drawn from a weighted population code. We show that Pachai et al.'s [5] own data actually provide evidence for the population code we have described [3], and we suggest a biologically-plausible analysis of their stimuli that provides a computational basis for their 'grouping' account of crowding.

  2. Discovery of a metastable Al{sub 20}Sm{sub 4} phase

    SciTech Connect

    Ye, Z. E-mail: kmh@ameslab.gov; Zhang, F.; Mendelev, M. I.; Ott, R. T.; Park, E.; Besser, M. F.; Kramer, M. J.; Wang, C.-Z.; Sun, Y.; Ding, Z.; Ho, K.-M. E-mail: kmh@ameslab.gov

    2015-03-09

    We present an efficient genetic algorithm, integrated with experimental diffraction data, to solve a nanoscale metastable Al{sub 20}Sm{sub 4} phase that evolves during crystallization of an amorphous magnetron sputtered Al{sub 90}Sm{sub 10} alloy. The excellent match between calculated and experimental X-ray diffraction patterns confirms an accurate description of this metastable phase. Molecular dynamic simulations of crystal growth from the liquid phase predict the formation of disordered defects in the devitrified crystal.

  3. Amorphous AlPO sub 4 as catalyst support: 2. Characterization of amorphous aluminum phosphates

    SciTech Connect

    Rebenstorf, B.; Lindblad, T.; Andersson, S.L.T. )

    1991-04-01

    Three different amorphous aluminum phosphates have been characterized by their specific surface area and pore volume and by XPS and FTIR studies. Three types of Al surface hydroxyl groups at 3793.8, 3768.5, and 3743.2 cm{sup {minus}1} and only one type of P surface hydroxyl groups at 3677.5 cm{sup {minus}1} are found in FTIR spectra after evacuation at 800{degree}C. The ratio of the integrated absorbance of the IR bands from AlOH and POH surface groups is a sensitive tool to study the surface of AlPO{sub 4} directly. A linear relation between the electronegativity of the metal ion and the stretching vibration of surface hydroxyl groups is proposed for Al, Si, P, and B tetrahedral surface ions. The three Al surface hydroxyl groups are assigned to four-coordinated (tetrahedral), five-coordinated, and six-coordinated surface Al ions. Amorphous AlPO{sub 4} contains four- and five-coordinated Al ions and AlPO{sub 4} with high specific surface area also has six-coordinated Al ions at the surface. CO is adsorbed on the phosphorus surface hydroxyl groups at low temperature, giving an IR band at 2170 cm{sup {minus}1}, while the IR band from the PO-H group is shifted to 3495 cm{sup {minus}1}. On AlPO{sub 4} of high surface area, CO is also adsorbed on coordinatively unsaturated, five-coordinated Al surface ions. Four-coordinated Al ions are also found, but none with the coordination number three. Impregnation with chromium compounds in ethanol does not change the specific surface area, whereas impregnation in water resulted in a decreased specific surface area, to less than half of its previous value.

  4. Everyday Life with ALS: A Practical Guide

    MedlinePlus

    ... course of ALS. ALS also will require some adaptations to your environment, both for safety and to ... the way, Chapter 6 will include information on adaptations for computer access. Though the chapter is called “ ...

  5. Effects of the Al content on pore structures of porous TieAl alloys

    SciTech Connect

    Jaing, Y; He, Y H; Xu, N P; Zou, J; Huang, B; Lui, C T

    2008-01-01

    Porous TieAl alloys with different nominal compositions were fabricated through a reactive synthesis of Ti and Al elemental powders. It has been found that the pore parameters vary with the Al contents, indicating that the nature of the pores can be manipulated through changing the Al contents. In addition, detailed structural characterizations showed that the fabricated porous TieAl alloys can have three crystalline phases (i.e., a2-Ti3Al, g-TiAl, and TiAl3) when using different compositions. The fundamental reasons behind these phenomena have been explored.

  6. Implementation of a hydrologic model and GIS for estimating Wadi runoff in Dernah area, Al Jabal Al Akhadar, NE Libya

    NASA Astrophysics Data System (ADS)

    El Osta, M. M.; Masoud, M. H.

    2015-07-01

    This study has investigated the relationship between rainfall-runoff in Dernah area, Al Jabal Al Akhadar, NE Libya. It provides flash flood hazard warnings for ungauged basins using geographic information system (GIS). The study examined the morphometric parameters of four Wadis (Wadi Dernah, Wadi Bum Safer, Wadi Al Nagah and Wadi Bir Al Yajur) with emphasis on their implication for hydrologic processes through the integration analysis between morphometric parameters and GIS techniques. Data for this study were obtained from ASTER data for digital elevation model (DEM) with 30 m resolution, topographic map (1:50,000), geological maps (1,250,000) which were checked during the field work. About 36 morphometric parameters were measured and calculated and interlinked to produce nine effective parameters for evaluating the flash flood hazard degree of the study area. The study basins are classified according to their hazards into three groups; Basins of low hazard degree (Wadi Al Nagah and Wadi Bir Al Yajur); Basins of medium hazard degree (Wadi Dernah); Basins of high hazard degree (Bum Safer). Software (SMADA 6) is applied to generate the hydrograph of subbasins of both medium and high hazard degrees. As a result of the model applied to Wadi Dernah, rainfall events of a total of 60, 70, 90, 110 and 120 mm of return periods 5, 10, 25, 50 and 100 years produce a discharge volume of 9.1 × 106, 13.5 × 106, 22.3 × 106, 34.0 × 106 and 39.7 × 106 m3 respectively. While in case of Wadi Bum Safer the discharge volume is 22.1 × 106, 30.5 × 106, 46.1 × 106, 65.6 × 106 and 74.8 × 106 m3.

  7. Hybrid UV Imager Containing Face-Up AlGaN/GaN Photodiodes

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu; Pain, Bedabrata

    2005-01-01

    A proposed hybrid ultraviolet (UV) image sensor would comprise a planar membrane array of face-up AlGaN/GaN photodiodes integrated with a complementary metal oxide/semiconductor (CMOS) readout-circuit chip. Each pixel in the hybrid image sensor would contain a UV photodiode on the AlGaN/GaN membrane, metal oxide/semiconductor field-effect transistor (MOSFET) readout circuitry on the CMOS chip underneath the photodiode, and a metal via connection between the photodiode and the readout circuitry (see figure). The proposed sensor design would offer all the advantages of comparable prior CMOS active-pixel sensors and AlGaN UV detectors while overcoming some of the limitations of prior (AlGaN/sapphire)/CMOS hybrid image sensors that have been designed and fabricated according to the methodology of flip-chip integration. AlGaN is a nearly ideal UV-detector material because its bandgap is wide and adjustable and it offers the potential to attain extremely low dark current. Integration of AlGaN with CMOS is necessary because at present there are no practical means of realizing readout circuitry in the AlGaN/GaN material system, whereas the means of realizing readout circuitry in CMOS are well established. In one variant of the flip-chip approach to integration, an AlGaN chip on a sapphire substrate is inverted (flipped) and then bump-bonded to a CMOS readout circuit chip; this variant results in poor quantum efficiency. In another variant of the flip-chip approach, an AlGaN chip on a crystalline AlN substrate would be bonded to a CMOS readout circuit chip; this variant is expected to result in narrow spectral response, which would be undesirable in many applications. Two other major disadvantages of flip-chip integration are large pixel size (a consequence of the need to devote sufficient area to each bump bond) and severe restriction on the photodetector structure. The membrane array of AlGaN/GaN photodiodes and the CMOS readout circuit for the proposed image sensor would

  8. Nonstoichiometry of Al-Zr intermetallic phases

    SciTech Connect

    Radmilovic, V.; Thomas, G.

    1994-06-01

    Nonstoichiometry of metastable cubic {beta}{prime} and equilibrium tetragonal {beta} Al-Zr intermetallic phases of the nominal composition Al{sub 3}Zr in Al-rich alloys has been extensively studied. It is proposed that the ``dark contrast`` of {beta}{prime} core in {beta}{prime}/{sigma}{prime} complex precipitates, in Al-Li-Zr based alloys, is caused by incorporation of Al and Li atoms into the {beta}{prime} phase on Zr sublattice sites, forming nonstoichiometric Al-Zr intermetallic phases, rather than by Li partitioning only. {beta}{prime} particles contain very small amounts of Zr, approximately 5 at.%, much less than the stoichiometric 25 at.% in the Al{sub 3}Zr metastable phase. These particles are, according to simulation of high resolution images, of the Al{sub 3}(Al{sub 0.4}Li{sub 0.4}Zr{sub 0.2}) type. Nonstoichiometric particles of average composition Al{sub 4}Zr and Al{sub 6}Zr are observed also in the binary Al-Zr alloy, even after annealing for several hours at 600{degree}C.

  9. Cyclic oxidation resistance of a reaction milled NiAl-AlN composite

    NASA Technical Reports Server (NTRS)

    Lowell, Carl E.; Barrett, Charles A.; Whittenberger, J. D.

    1990-01-01

    Based upon recent mechanical property tests a NiAl-AlN composite produced by cryomilling has very attractive high temperature strength. This paper focuses on the oxidation resistance of the NiAl-AlN composite at 1473 and 1573 K as compared to that of Ni-47Al-0.15Zr, one of the most oxidation resistant intermetallics. The results of cyclic oxidation tests show that the NiAl-AlN composite has excellent properties although not quite as good as those of Ni-47Al-0.15Zr. The onset of failure of the NiAl-AlN was unique in that it was not accompanied by a change in scale composition from alumina to less protective oxides. Failure in the composite appears to be related to the entrapment of AlN particles within the alumina scale.

  10. Wear behavior of Al-Al{sub 3}Ti composite manufactured by a centrifugal method

    SciTech Connect

    Watanabe, Yoshimi; Yamanaka, Noboru; Fukui, Yasuyoshi

    1999-12-01

    The purpose of the present study was to develop a wear-resistant, light Al-Al{sub 3}Ti composite material. An Al-Al{sub 3}Ti composite specimen was machined from a thick-walled tube of Al-Al{sub 3}Ti functionally graded material (FGM) manufactured by the centrifugal method from a commercial ingot of Al-5 mass% Ti master alloy. The alloy was heated to a temperature where solid Al{sub 3}Ti particles resided in a liquid Al matrix, and then the centrifugal method was carried out. Al{sub 3}Ti particles in a commercial alloy ingot exist as platelets, and this shape was maintained through the casting. Three kinds of wear specimens were prepared, taking into account the morphology of the Al{sub 3}Ti particles in the thick-walled FGM tube; the Al{sub 3}Ti particles were arranged with their platelet planes nearly normal to the radial direction as a result of the applied centrifugal force. The wear resistance of the Al-Al{sub 3}Ti composite was significantly higher than that of pure Al. Wear-resistance anisotropy and dissolution of the Al{sub 3}Ti into the Al matrix at the near-surface region, around 100 {micro}m in depth, were also observed. The mechanism of the supersaturated-layer formation and the origin of the anisotropic wear resistance are discussed.

  11. Systems Engineering Techniques for ALS Decision Making

    NASA Technical Reports Server (NTRS)

    Rodriquez, Luis F.; Drysdale, Alan E.; Jones, Harry; Levri, Julie A.

    2004-01-01

    The Advanced Life Support (ALS) Metric is the predominant tool for predicting the cost of ALS systems. Metric goals for the ALS Program are daunting, requiring a threefold increase in the ALS Metric by 2010. Confounding the problem, the rate new ALS technologies reach the maturity required for consideration in the ALS Metric and the rate at which new configurations are developed is slow, limiting the search space and potentially giving the perspective of a ALS technology, the ALS Metric may remain elusive. This paper is a sequel to a paper published in the proceedings of the 2003 ICES conference entitled, "Managing to the metric: an approach to optimizing life support costs." The conclusions of that paper state that the largest contributors to the ALS Metric should be targeted by ALS researchers and management for maximum metric reductions. Certainly, these areas potentially offer large potential benefits to future ALS missions; however, the ALS Metric is not the only decision-making tool available to the community. To facilitate decision-making within the ALS community a combination of metrics should be utilized, such as the Equivalent System Mass (ESM)-based ALS metric, but also those available through techniques such as life cycle costing and faithful consideration of the sensitivity of the assumed models and data. Often a lack of data is cited as the reason why these techniques are not considered for utilization. An existing database development effort within the ALS community, known as OPIS, may provide the opportunity to collect the necessary information to enable the proposed systems analyses. A review of these additional analysis techniques is provided, focusing on the data necessary to enable these. The discussion is concluded by proposing how the data may be utilized by analysts in the future.

  12. Youth services: the need to integrate mental health, physical health and social care: Commentary on Malla et al.: From early intervention in psychosis to youth mental health reform: a review of the evolution and transformation of mental health services for young people.

    PubMed

    Yung, Alison R

    2016-03-01

    Mental distress and mental health disorders are common in young people. Indeed, over 75 % of mental disorders begin before the age of 25 years. Long delays in seeking help for illnesses are common, initial intervention is often ineffective and young people are at risk of disengaging with treatment, particularly when they are expected to move from child and adolescent treating teams to adult services. All of these factors mean that young people are vulnerable to prolonged mental ill-health and its consequences, including educational failure, unemployment, social disengagement and deprivation, and development of further mental health problems including substance misuse. Malla et al. present different service models that attempt to address these issues. Additionally, there needs to be a focus on physical health and social care as these are intertwined with mental health.

  13. Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3

    NASA Astrophysics Data System (ADS)

    Zhang, Guozhen; Wu, Hao; Chen, Chao; Wang, Ti; Yue, Jin; Liu, Chang

    2015-02-01

    Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3 dielectrics have been fabricated on indium tin oxide-coated polyethylene naphthalate substrates by atomic layer deposition. A capacitance density of 7.8 fF/μm2 at 10 KHz was obtained, corresponding to a dielectric constant of 26.3. Moreover, a low leakage current density of 3.9 × 10-8 A/cm2 at 1 V has been realized. Bending test shows that the capacitors have better performances in concave conditions than in convex conditions. The capacitors exhibit an average optical transmittance of about 70% in visible range and thus open the door for applications in transparent and flexible integrated circuits.

  14. Radiative Properties of Ceramic Al2O3, AlN, and Si3N4: I. Experiments

    NASA Astrophysics Data System (ADS)

    Cheng, Qiang; Yang, Peiyan; Zhang, Zhuomin

    2016-06-01

    The radiative properties of dense ceramic Al2O3, AlN, and Si3N4 plates are investigated from the visible to the mid-infrared region at room temperature. Each specimen has different surface finishings on different sides of the laminate. A monochromator was used with an integrating sphere to measure the directional-hemispherical reflectance and transmittance of these samples at wavelengths from 0.4 μ m to 1.8 μ m. The specular reflectance was obtained by a subtraction technique. A Fourier-transform infrared spectrometer was used to measure the directional-hemispherical or specular reflectance and transmittance with appropriate accessories from about 1.6 μ m to 19 μ m. All measurements were performed at near-normal incidence on either the smooth side or the rough side of the sample. The experimental observations are qualitatively interpreted considering the optical constants, surface roughness, and volume scattering and absorption.

  15. Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3.

    PubMed

    Zhang, Guozhen; Wu, Hao; Chen, Chao; Wang, Ti; Yue, Jin; Liu, Chang

    2015-01-01

    Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3 dielectrics have been fabricated on indium tin oxide-coated polyethylene naphthalate substrates by atomic layer deposition. A capacitance density of 7.8 fF/μm(2) at 10 KHz was obtained, corresponding to a dielectric constant of 26.3. Moreover, a low leakage current density of 3.9 × 10(-8) A/cm(2) at 1 V has been realized. Bending test shows that the capacitors have better performances in concave conditions than in convex conditions. The capacitors exhibit an average optical transmittance of about 70% in visible range and thus open the door for applications in transparent and flexible integrated circuits.

  16. Layer disordering and doping compensation of an intersubband AlGaN/AlN superlattice by silicon implantation

    NASA Astrophysics Data System (ADS)

    Wierer, J. J.; Allerman, A. A.; Skogen, E. J.; Tauke-Pedretti, A.; Alford, C.; Vawter, G. A.; Montaño, I.

    2014-09-01

    Layer disordering and doping compensation of an Al0.028Ga0.972N/AlN superlattice by implantation are demonstrated. The as-grown sample exhibits intersubband absorption at ˜1.56 μm which is modified when subject to a silicon implantation. After implantation, the intersubband absorption decreases and shifts to longer wavelengths. Also, with increasing implant dose, the intersubband absorption decreases. It is shown that both layer disordering of the heterointerfaces and doping compensation from the vacancies produced during the implantation cause the changes in the intersubband absorption. Such a method is useful for removing absorption in spatially defined areas of III-nitride optoelectronic devices by, for example, creating low-loss optical waveguides monolithically that can be integrated with as-grown areas operating as electro-absorption intersubband modulators.

  17. Nb/Al-Al2O3/Nb junctions with inductive tuning elements for a very low noise 205-250 GHz heterodyne receiver

    NASA Technical Reports Server (NTRS)

    Lichtenberger, Arthur W.; Lea, Dallas M.; Mattauch, Robert J.; Lloyd, Frances L.

    1992-01-01

    The superconductor-insulator-superconductor (SIS) junction is the most sensitive nonlinear element for millimeter-wave heterodyne detection. An Nb/Al-Al203/Nb junction fabrication process has been developed which allows the use of planar tuning circuits integrated with the junctions. These tuning elements permit the use of junctions with relatively large areas and small current densities with excellent results. Recent measurements have yielded a double sideband receiver noise temperature less than 50 K from 205 to 240 GHz and 44 K at 230 GHz. This Nb/Al-Al203/Nb trilayer technology is also being extended to the fabrication of sub-square-micron area planar junctions for submillimeter-wavelengths.

  18. Instandhaltungsmanagement als Gestaltungsfeld Ganzheitlicher Produktionssysteme

    NASA Astrophysics Data System (ADS)

    Dombrowski, Uwe; Schulze, Sven; Otano, Isabel Crespo

    Sich kontinuierlich verändernde Rahmenbedingungen, wie beispielsweise eine steigende Variantenvielfalt, verkürzte Produktlebenszyklen sowie Kundenforderungen nach höherer Qualität, kürzeren Lieferzeiten und geringeren Kosten, fordern von produzierenden Unternehmen eine stetige Anpassung der Prozesse, der Organisation und der Strukturen. Seit den 90er Jahren versuchen immer mehr deutsche Unternehmen diesen veränderten Anforderungen mit der Einführung eines Ganzheitlichen Produktionssystems (GPS) zu begegnen. Ganzheitliche Produktionssysteme sind dabei in ihren Grundlagen an das Toyota Produktionssystem angelehnt, vereinigen aber auch weitere Methoden zu einem unternehmensspezifischen Regelwerk. Im Rahmen des langfristigen Trends zu unternehmensindividuellen Produktionssystemen wird sowohl in der Industrie als auch in der Forschung intensiv über das Toyota Produktionssystem, Lean Production, Lean Management und Ganzheitliche Produktionssysteme diskutiert, werden Konzepte zu Implementierung und Betrieb erstellt und die Wirtschaftlichkeit untersucht.

  19. The GRAVITY integrated optics beam combination

    NASA Astrophysics Data System (ADS)

    Jocou, L.; Perraut, K.; Nolot, A.; Berger, J. P.; Moulin, T.; Labeye, P.; Lacour, S.; Perrin, G.; Lebouquin, J. B.; Bartko, H.; Thiel, M.; Eisenhauer, F.

    2010-07-01

    Gravity is a 2nd generation interferometric instrument for VLTI. It will combine 4 telescopes in dual feed in the K band to study general relativity effects around the Galactic Center black hole. The concept of Gravity is based on two equivalent beam combiner instruments: the scientific one fed by the science target (Sgr A*) and the fringe tracker fed by a bright reference star (See Gillessen et al.1). Both beam combination instruments are based on silica on silicon integrated optics (IO) component glued to fluoride glass fiber array. The beam combiners are implemented in a cryogenic vessel cooled at 200°K and back-illuminated by a high power laser used for metrology (Bartko et al.2). This paper is dedicated to the description of the development of the integrated beam combiner assembly.

  20. Structure and stability of the AlX and AlX{sup {minus}} species

    SciTech Connect

    Gutsev, G.L.; Jena, P.; Bartlett, R.J.

    1999-02-01

    The electronic and geometrical structures of the ground and low-lying excited states of the diatomic AlX and AlX{sup {minus}} series (X=H, Li, Be, B, C, N, O, and F) are calculated by the coupled-cluster method with all singles and doubles and noniterative inclusion of triples using a large atomic natural orbital basis. All the ground-state AlX molecules except for AlF can attach an additional electron and form ground-state AlX{sup {minus}} anions. The ground-state AlBe{sup {minus}}, AlB{sup {minus}}, AlC{sup {minus}}, AlN{sup {minus}}, and AlO{sup {minus}} anions possess excited states that are stable toward autodetachment of an extra electron; AlBe{sup {minus}} also has a second excited state. Low-lying excited states of all AlX but AlN can attach an extra electron and form anionic states that are stable with respect to their neutral (excited) parent states. The ground-state AlLi{sup {minus}}, AlBe{sup {minus}}, AlB{sup {minus}}, AlN{sup {minus}}, and AlO{sup {minus}} anions are found to be thermodynamically more stable than their neutral parents. The most stable is AlO{sup {minus}}, whose dissociation energy to Al+O{sup {minus}} is 6.4 eV. Correspondingly, AlO possesses the largest electron affinity (2.65 eV) in the series. {copyright} {ital 1999 American Institute of Physics.}

  1. Accumulation of Al in Root Mucilage of an Al-Resistant and an Al-Sensitive Cultivar of Wheat.

    PubMed Central

    Archambault, D. J.; Zhang, G.; Taylor, G. J.

    1996-01-01

    To estimate rates of Al accumulation within the symplasm, all apoplastic pools of Al need to be eliminated or accounted for. We have developed a revised kinetic protocol that allows us to estimate the contribution of mucilage-bound Al to total, nonexchangeable Al, and to eliminate the mucilage as an apoplastic pool of Al. By comparing the Al content of excised root tips (2 cm) of wheat (Triticum aestivum L.) with and without the removal of the mucilage (using a 10-min wash in 1 M NH4Cl), we found that Al bound to the mucilage accounted for approximately 25 to 35% of Al remaining after desorption in citric acid. The kinetics of Al uptake into mucilage were biphasic, with a rapid phase occurring in the first 30 min of uptake, followed by a linear phase occurring in the remainder of the experimental period (180 min). By adopting a step for removal of mucilage into our existing kinetic protocol, we have been able to isolate a linear phase of uptake with only a slight deviation from linearity in the first 5 min. Although we cannot unambiguously identify this phase of uptake as uptake into the symplasm, we believe this new protocol provides us with the most accurate quantitative estimate of symplastic Al yet available. PMID:12226458

  2. Magnetism of Al-substituted magnetite reduced from Al-hematite

    NASA Astrophysics Data System (ADS)

    Jiang, Zhaoxia; Liu, Qingsong; Zhao, Xiang; Roberts, Andrew P.; Heslop, David; Barrón, Vidal; Torrent, José

    2016-06-01

    Aluminum-substituted magnetite (Al-magnetite) reduced from Al-substituted hematite or goethite (Al-hematite or Al-goethite) is an environmentally important constituent of magnetically enhanced soils. In order to characterize the magnetic properties of Al-magnetite, two series of Al-magnetite samples were synthesized through reduction of Al-hematite by a mixed gas (80% CO2 and 20% CO) at 395°C for 72 h in a quartz tube furnace. Al-magnetite samples inherited the morphology of their parent Al-hematite samples, but only those transformed from Al-hematite synthesized at low temperature possessed surficial micropores, which originated from the release of structural water during heating. Surface micropores could thus serve as a practical fingerprint of fire or other high-temperature mineralogical alteration processes in natural environments, e.g., shear friction in seismic zones. In addition, Al substitution greatly affects the magnetic properties of Al-magnetite. For example, coercivity (Bc) increases with increasing Al content and then decreases slightly, while the saturation magnetization (Ms), Curie temperature (Tc), and Verwey transition temperature (Tv) all decrease with increasing Al content due to crystal defect formation and dilution of magnetic ions caused by Al incorporation. Moreover, different trends in the correlation between Tc and Bc can be used to discriminate titanomagnetite from Al-magnetite, which is likely to be important in environmental and paleomagnetic studies, particularly in soil.

  3. Reactive Plasma Spraying of Fine Al2O3/AlN Feedstock Powder

    NASA Astrophysics Data System (ADS)

    Shahien, Mohammed; Yamada, Motohiro; Yasui, Toshiaki; Fukumoto, Masahiro

    2013-12-01

    Reactive plasma spraying (RPS) is a promising technology for in situ formation of aluminum nitride (AlN) coatings. Recently, AlN-based coatings were fabricated by RPS of alumina (Al2O3) powder in N2/H2 thermal plasma. This study investigated the feasibility of RPS of a fine Al2O3/AlN mixture and the influence of the plasma gases (N2, H2) on the nitriding conversion, and coating microstructure and properties. Thick AlN/Al2O3 coatings with high nitride content were successfully fabricated. The coatings consist of h-AlN, c-AlN, Al5O6N, γ-Al2O3, and a small amount of α-Al2O3. Use of fine particles enhanced the nitriding conversion and the melting tendency by increasing the surface area. Furthermore, the AlN additive improved the AlN content in the coatings. Increasing the N2 gas flow rate improved the nitride content and complete crystal growth to the h-AlN phase, and enhanced the coating thickness. On the other hand, though the H2 gas is required for plasma nitriding of the Al2O3 particles, increasing its flow rate decreased the nitride content and the coating thickness. Remarkable influence of the plasma gases on the coating composition, microstructure, and properties was observed during RPS of the fine particles.

  4. TIPs for Technology Integration.

    ERIC Educational Resources Information Center

    Mandell, Susan; Sorge, Dennis H.; Russell, James D.

    2002-01-01

    Discusses the role of the teacher in effectively using technology in education based on the Technology Integration Project (TIP). Topics include why use technology; types of computer software; how to select software; software integration strategies; and effectively planning lessons that integrate the chosen software and integration strategy. (LRW)

  5. 77 FR 73732 - In the Matter of Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... al-Rafidayn, aka The Organization of al-Jihad's Base of Operations in Iraq, aka al-Qaida of Jihad in Iraq, aka al-Qaida in Iraq, aka al-Qaida in Mesopotamia, aka al-Qaida in the Land of the Two Rivers, aka al-Qaida of the Jihad in the Land of the Two Rivers, aka al-Qaida of Jihad Organization in......

  6. A comparison of mechanical properties between Al and Al3Mg

    NASA Astrophysics Data System (ADS)

    Yang, Rong; Tang, Bin; Gao, Tao

    2016-11-01

    On the basis of first principles calculations, we have calculated the elastic properties, stress-strain relations, ideal tensile strengths, ideal shear strengths, and the ideal compressed strengths of Al and Al3Mg. The stress-strain relations of Al3Mg are strikingly similar to those of Al, indicating that the crystal structure appears to be more important than the identity of the individual atoms during uniaxial deformation. Al3Mg is found to have larger moduli and higher strengths than Al but less ductile than Al. So Al3Mg is expected to be a harder material, consistent with its exploitation in Al precipitate-hardening mechanisms. The calculated elastic properties, tensile strengths and shear strengths of Al are consistent with experimental values or previous theoretical results. We also use another method (molecular dynamics (MD) simulations) to recalculate elastic constants, ideal tensile and compressed strength of Al3Mg for checking and comparing. We find that the results obtained by the two methods agree well with each other. The failure modes under uniaxial <100> tension are also explored for Al and Al3Mg. Our calculations confirm that Al fail by shear and predict that Al3Mg also fail by shear.

  7. Influences of Al particles on the microstructure and property of electrodeposited Ni-Al composite coatings

    NASA Astrophysics Data System (ADS)

    Cai, Fei; Jiang, Chuanhai

    2014-02-01

    Ni-Al composite coatings with different contents of Al microparticles were prepared from a conventional Watt bath. The influences of Al particle loadings in the bath on the surface morphology, composition, texture, grain size, microstrain, residual stress and anti-corrosion of the Ni-Al composite coating were investigated. The friction coefficients of the coatings at 200 °C were also evaluated by a pin-on-disctribometer. The results showed that the surface morphology of the coatings changed from pyramid + colonied structure to colonied structure with increasing Al particle loadings. The (2 0 0) preferred orientation for pure Ni coating evolved to random orientation with increasing Al particle loadings. The grain size obtained the minimum value of 72.28 nm at Al particle loading of 100 g/L and the microstrain of the coating increased with increasing the Al particle loadings. The incorporation of Al particles decreased the residual stress of the electro-deposited coating and all the coatings deposited at different Al particle loadings possessed low residual stress. As the Al particle loading increased, the anti-corrosion of the Ni-Al coatings increased owing to the combined effect of increasing Al content in the coatings and the texture evolution from (2 0 0) plane to (1 1 1) plane. The wear result suggested that the increasing Al particle content did not improve the wear performance of the Ni-Al composite coatings.

  8. Interfacial phenomena in the reactions of Al-B, Al-Ti-B, and Al-Zr-B alloys with KF-AlF{sub 3} and NaF-AlF{sub 3} melts

    SciTech Connect

    Lee, M.S.; Terry, B.S.; Grieveson, P.

    1993-12-01

    The interfacial phenomena occurring during the contacting of liquid Al-B, Al-Ti-B, and Al-Zr-B melts with KF-AlF{sub 3} liquid fluxes have been investigated by optical examination of quenched metal drops previously immersed in the liquid fluxes. Reactions in the Al-B/KF-AlF{sub 3} system involve the formation of metastable AlB{sub 12} at the metal/flux interface. At high KBF{sub 4} levels in the flux, the AlB{sub 12} is dispersed in the flux and also at low KBF{sub 4} levels in the metal. Reactions in the Al-Ti-B/KF-AlF{sub 3} system involve the formation of TiB{sub 2}, which may be dispersed in either the metal or the flux depending upon the composition of the flux. The results obtained for the Al-Ti-B/NaF-AlF{sub 3} and Al-Zr-B/KF-AlF{sub 3} systems were similar to those observed for the Al-Ti-B/KF-AlF{sub 3} system.

  9. The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures

    PubMed Central

    Shu, Lin; Peng, Bin; Li, Chuan; Gong, Dongdong; Yang, Zhengbing; Liu, Xingzhao; Zhang, Wanli

    2016-01-01

    We report in this paper on the study of surface acoustic wave (SAW) resonators based on an AlN/titanium alloy (TC4) structure. The AlN/TC4 structure with different thicknesses of AlN films was simulated, and the acoustic propagating modes were discussed. Based on the simulation results, interdigital transducers with a periodic length of 24 μm were patterned by lift-off photolithography techniques on the AlN films/TC4 structure, while the AlN film thickness was in the range 1.5–3.5 μm. The device performances in terms of quality factor (Q-factor) and electromechanical coupling coefficient (k2) were determined from the measure S11 parameters. The Q-factor and k2 were strongly dependent not only on the normalized AlN film thickness but also on the full-width at half-maximum (FWHM) of AlN (002) peak. The dispersion curve of the SAW phase velocity was analyzed, and the experimental results showed a good agreement with simulations. The temperature behaviors of the devices were also presented and discussed. The prepared SAW resonators based on AlN/TC4 structure have potential applications in integrated micromechanical sensing systems. PMID:27077864

  10. The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures.

    PubMed

    Shu, Lin; Peng, Bin; Li, Chuan; Gong, Dongdong; Yang, Zhengbing; Liu, Xingzhao; Zhang, Wanli

    2016-04-12

    We report in this paper on the study of surface acoustic wave (SAW) resonators based on an AlN/titanium alloy (TC4) structure. The AlN/TC4 structure with different thicknesses of AlN films was simulated, and the acoustic propagating modes were discussed. Based on the simulation results, interdigital transducers with a periodic length of 24 μm were patterned by lift-off photolithography techniques on the AlN films/TC4 structure, while the AlN film thickness was in the range 1.5-3.5 μm. The device performances in terms of quality factor (Q-factor) and electromechanical coupling coefficient (k²) were determined from the measure S11 parameters. The Q-factor and k² were strongly dependent not only on the normalized AlN film thickness but also on the full-width at half-maximum (FWHM) of AlN (002) peak. The dispersion curve of the SAW phase velocity was analyzed, and the experimental results showed a good agreement with simulations. The temperature behaviors of the devices were also presented and discussed. The prepared SAW resonators based on AlN/TC4 structure have potential applications in integrated micromechanical sensing systems.

  11. The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures.

    PubMed

    Shu, Lin; Peng, Bin; Li, Chuan; Gong, Dongdong; Yang, Zhengbing; Liu, Xingzhao; Zhang, Wanli

    2016-01-01

    We report in this paper on the study of surface acoustic wave (SAW) resonators based on an AlN/titanium alloy (TC4) structure. The AlN/TC4 structure with different thicknesses of AlN films was simulated, and the acoustic propagating modes were discussed. Based on the simulation results, interdigital transducers with a periodic length of 24 μm were patterned by lift-off photolithography techniques on the AlN films/TC4 structure, while the AlN film thickness was in the range 1.5-3.5 μm. The device performances in terms of quality factor (Q-factor) and electromechanical coupling coefficient (k²) were determined from the measure S11 parameters. The Q-factor and k² were strongly dependent not only on the normalized AlN film thickness but also on the full-width at half-maximum (FWHM) of AlN (002) peak. The dispersion curve of the SAW phase velocity was analyzed, and the experimental results showed a good agreement with simulations. The temperature behaviors of the devices were also presented and discussed. The prepared SAW resonators based on AlN/TC4 structure have potential applications in integrated micromechanical sensing systems. PMID:27077864

  12. Growth and Stress-induced Transformation of Zinc blende AlN Layers in Al-AlN-TiN Multilayers

    PubMed Central

    Li, Nan; Yadav, Satyesh K.; Wang, Jian; Liu, Xiang-Yang; Misra, Amit

    2015-01-01

    AlN nanolayers in sputter deposited {111}Al/AlN/TiN multilayers exhibit the metastable zinc-blende-structure (z-AlN). Based on density function theory calculations, the growth of the z-AlN is ascribed to the kinetically and energetically favored nitridation of the deposited aluminium layer. In situ nanoindentation of the as-deposited {111}Al/AlN/TiN multilayers in a high-resolution transmission electron microscope revealed the z-AlN to wurzite AlN phase transformation through collective glide of Shockley partial dislocations on every two {111} planes of the z-AlN. PMID:26681109

  13. Growth and stress-induced transformation of zinc blende AlN layers in Al-AlN-TiN multilayers

    DOE PAGES

    Li, Nan; Yadav, Satyesh K.; Wang, Jian; Liu, Xiang -Yang; Misra, Amit

    2015-12-18

    We report that AlN nanolayers in sputter deposited {111}Al/AlN/TiN multilayers exhibit the metastable zinc-blende-structure (z-AlN). Based on density function theory calculations, the growth of the z-AlN is ascribed to the kinetically and energetically favored nitridation of the deposited aluminium layer. In situ nanoindentation of the as-deposited {111}Al/AlN/TiN multilayers in a high-resolution transmission electron microscope revealed the z-AlN to wurzite AlN phase transformation through collective glide of Shockley partial dislocations on every two {111} planes of the z-AlN.

  14. [Doppler effect on width of characteristic line in plasma induced by pulsed laser ablating Al].

    PubMed

    Song, Yi-Zhong; He, An-Zhi

    2005-05-01

    Aluminum (Al) plasma was induced with a pulsed Nd: YAG laser beam ablating Al target in Ar. Time-resolved information of the plasma radiation was taken with time-resolved technique, and the spectra of the radiation were recorded with an optical multi-path analyzer (OMA III ), whereupon, time-resolved spectra of the plasma radiation induced by pulsed laser were acquired. Based on the experiment data, Al resonant double lines, Al I 396.15 nm, Al I 394.40 nm, were respectively fitted with Lorentz, Gauss and their linear integrated function (abbr. Integrated function), whereupon, Lorentz and Gauss elements were separated from the experiment data profile curve. By contrasting Lorentz with Gauss curve separated, it was found that the experiment curve mainly consisted of Lorentz element, a with little Gauss. By contrasting Lorentz with Integrated fitting curve for experiment data, a visual picture of the characteristic lines broadened by Doppler effect was exhibited. According to the visual picture, the increase of full half-high width of the characteristic line broadened by Doppler effect was estimated. It was about 2 x 10(-)3 -8 x 10(-3) nm, approximating the theoretical value 6.7 x 10(-)3 nm. As a result, Doppler effect on the width of characteristic lines in the plasma could be reasonably explained by curve fitting analysis and theoretical calculation.

  15. Mechanical alloying of nb-al powders

    NASA Astrophysics Data System (ADS)

    Peng, Zhixue; Suryanarayana, C.; Froes, F. H. (Sam)

    1996-01-01

    The effect of mechanical alloying (MA) on solid solubility extension, nanostructure formation, amorphization, intermetallic compound formation, and the occurrence of a face-centered cubic (fcc) phase in the Nb-Al system has been studied. Solid solubility extension was observed in both the terminal compositions and intermetallic compounds: 15 pct Nb in Al and 60 pct Al in Nb, well beyond the equilibrium and even rapid solidification levels (2.4 pct Nb and 25 pct Al, respectively) and increased homogeneity range for the NbAl3 phase. Nanostructured grains formed in all compositions. In the central part of the phase diagram, amorphization occurred predominantly. Only NbAl3, the most stable intermetallic, formed during MA; in most cases, a subsequent anneal was required. On long milling time, an fcc phase, probably a nitride, formed as a result of contamination from the ambient atmosphere.

  16. Mechanical alloying of Nb-Al powders

    SciTech Connect

    Peng, Z.; Suryanarayana, C.; Froes, F.H.

    1996-01-01

    The effect of mechanical alloying (MA) on solid solubility extension, nanostructure formation, amorphization, intermetallic compound formation, and the occurrence of a face-centered cubic (fcc) phase in the Nb-Al system has been studied. Solid solubility extension was observed in both the terminal compositions and intermetallic compounds: 15 pct Nb in Al and 60 pct Al in Nb, well beyond the equilibrium and even rapid solidification levels (2.4 pct Nb and 25 pct Al, respectively) and increased homogeneity range for the NbAl{sub 3} phase. Nanostructured grains formed in all compositions. In the central part of the phase diagram, amorphization occurred predominantly. Only NbAl{sub 3}, the most stable intermetallic, formed during MA; in most cases, a subsequent anneal was required. On long milling time, an fcc phase, probably a nitride, formed as a result of contamination from the ambient atmosphere.

  17. Orientation relationship of eutectoid FeAl and FeAl2

    PubMed Central

    Scherf, A.; Kauffmann, A.; Kauffmann-Weiss, S.; Scherer, T.; Li, X.; Stein, F.; Heilmaier, M.

    2016-01-01

    Fe–Al alloys in the aluminium range of 55–65 at.% exhibit a lamellar microstructure of B2-ordered FeAl and triclinic FeAl2, which is caused by a eutectoid decomposition of the high-temperature Fe5Al8 phase, the so-called ∊ phase. The orientation relationship of FeAl and FeAl2 has previously been studied by Bastin et al. [J. Cryst. Growth (1978 ▸), 43, 745] and Hirata et al. [Philos. Mag. Lett. (2008 ▸), 88, 491]. Since both results are based on different crystallographic data regarding FeAl2, the data are re-evaluated with respect to a recent re-determination of the FeAl2 phase provided by Chumak et al. [Acta Cryst. (2010 ▸), C66, i87]. It is found that both orientation relationships match subsequent to a rotation operation of 180° about a 〈112〉 crystallographic axis of FeAl or by applying the inversion symmetry of the FeAl2 crystal structure as suggested by the Chumak data set. Experimental evidence for the validity of the previously determined orientation relationships was found in as-cast fully lamellar material (random texture) as well as directionally solidified material (∼〈110〉FeAl || solidification direction) by means of orientation imaging microscopy and global texture measurements. In addition, a preferential interface between FeAl and FeAl2 was identified by means of trace analyses using cross sectioning with a focused ion beam. On the basis of these habit planes the orientation relationship between the two phases can be described by (01)FeAl || (114) and [111]FeAl || [10]. There is no evidence for twinning within FeAl lamellae or alternating orientations of FeAl lamellae. Based on the determined orientation and interface data, an atomistic model of the structure relationship of Fe5Al8, FeAl and FeAl2 in the vicinity of the eutectoid decomposition is derived. This model is analysed with respect to the strain which has to be accommodated at the interface of FeAl and FeAl2. PMID:27047304

  18. A New Phase in ALS Research.

    PubMed

    Chong, P Andrew; Forman-Kay, Julie D

    2016-09-01

    In this issue of Structure, Conicella et al. (2016) present evidence that the low complexity C-terminal region of TDP-43 undergoes liquid-liquid phase separation. ALS-associated mutations alter this phase separation process, providing a possible mechanism for the pathology caused by these TDP-43 mutations. The work is strongly supportive of toxic loss of RNA processing function in ALS. PMID:27602988

  19. Tensile Behavior of Al2o3/feal + B and Al2o3/fecraly Composites

    NASA Technical Reports Server (NTRS)

    Draper, S. L.; Eldridge, J. I.; Aiken, B. J. M.

    1995-01-01

    The feasibility of Al2O3/FeAl + B and Al2O3/FeCrAlY composites for high-temperature applications was assessed. The major emphasis was on tensile behavior of both the monolithics and composites from 298 to 1100 K. However, the study also included determining the chemical compatibility of the composites, measuring the interfacial shear strengths, and investigating the effect of processing on the strength of the single-crystal Al2O3 fibers. The interfacial shear strengths were low for Al203/FeAl + B and moderate to high for Al203/FeCrAlY. The difference in interfacial bond strengths between the two systems affected the tensile behavior of the composites. The strength of the Al203 fiber was significantly degraded after composite processing for both composite systems and resulted in poor composite tensile properties. The ultimate tensile strength (UTS) values of the composites could generally be predicted with either rule of mixtures (ROM) calculations or existing models when using the strength of the etched-out fiber. The Al2O3/FeAl + B composite system was determined to be unfeasible due to poor interfacial shear strengths and a large mismatch in coefficient of thermal expansion (CTE). Development of the Al2O3/FeCrAlY system would require an effective diffusion barrier to minimize the fiber strength degradation during processing and elevated temperature service.

  20. Memory deficits and retrieval processes in ALS.

    PubMed

    Mantovan, M C; Baggio, L; Dalla Barba, G; Smith, P; Pegoraro, E; Soraru', G; Bonometto, P; Angelini, C

    2003-05-01

    Subtle neuropsychological deficits have been described in patients affected by amyotrophic lateral sclerosis (ALS) without dementia. Overall, selective impairment in memory function has been reported, but the source of memory impairment in ALS has yet to be defined. We performed neuropsychological screening in 20 ALS patients. Semantic encoding and post-encoding cue effects on the retrieval of word lists were investigated in the ALS patients and normal controls. Severity of memory impairment was correlated to cerebral blood perfusion detected by single photon emission computed tomography (SPECT). ALS patients showed moderate impairments in frontal and memory tests. Short-term memory was normal, while serial position retrieval of word lists with normal recency effect but poor primacy effect showed long-term memory deficit. ALS patients performed better in cued encoding than in cued post-encoding recall condition. In the cued post-encoding condition, the primacy effect in word list recall improved significantly in controls, but not in ALS patients, as compared with both the free recall and cued encoding conditions. SPECT hypoperfusion was observed in frontal and temporal areas in ALS patients. ALS patients showed a long-term memory deficit which did not improve in cued post-encoding condition as it does for controls. We hypothesize abnormal retrieval processes related to frontal lobe dysfunction which entails difficulties in generating stable long-memory traces at encoding.

  1. Memory deficits and retrieval processes in ALS.

    PubMed

    Mantovan, M C; Baggio, L; Dalla Barba, G; Smith, P; Pegoraro, E; Soraru', G; Bonometto, P; Angelini, C

    2003-05-01

    Subtle neuropsychological deficits have been described in patients affected by amyotrophic lateral sclerosis (ALS) without dementia. Overall, selective impairment in memory function has been reported, but the source of memory impairment in ALS has yet to be defined. We performed neuropsychological screening in 20 ALS patients. Semantic encoding and post-encoding cue effects on the retrieval of word lists were investigated in the ALS patients and normal controls. Severity of memory impairment was correlated to cerebral blood perfusion detected by single photon emission computed tomography (SPECT). ALS patients showed moderate impairments in frontal and memory tests. Short-term memory was normal, while serial position retrieval of word lists with normal recency effect but poor primacy effect showed long-term memory deficit. ALS patients performed better in cued encoding than in cued post-encoding recall condition. In the cued post-encoding condition, the primacy effect in word list recall improved significantly in controls, but not in ALS patients, as compared with both the free recall and cued encoding conditions. SPECT hypoperfusion was observed in frontal and temporal areas in ALS patients. ALS patients showed a long-term memory deficit which did not improve in cued post-encoding condition as it does for controls. We hypothesize abnormal retrieval processes related to frontal lobe dysfunction which entails difficulties in generating stable long-memory traces at encoding. PMID:12752394

  2. Genetics of Familial and Sporadic ALS

    ClinicalTrials.gov

    2016-03-21

    Amyotrophic Lateral Sclerosis (ALS); Familial Amyotrophic Lateral Sclerosis; Amyotrophic Lateral Sclerosis With Frontotemporal Dementia; Lou Gehrig's Disease; Motor Neuron Disease; Primary Lateral Sclerosis

  3. Superbend era begins swiftly at the ALS

    SciTech Connect

    Robinson, Art; Tamura, Lori

    2001-11-29

    The successful installation and commissioning of high-field superconducting bend magnets (superbends) in three curved sectors of ALS storage ring was the first time the magnet lattice of an operating synchrotron light source has been retrofitted in this fundamental way. As a result, the ALS now offers an expanded spectral range well into the hard x-ray region without compromising either the number of undulators or their high brightness in the soft x-ray region for which the ALS design was originally optimized. In sum, when the superbend-enhanced ALS started up for user operations in October 2001, it marked the beginning of a new era in its history.

  4. Vulnerability of microRNA biogenesis in FTD-ALS.

    PubMed

    Eitan, Chen; Hornstein, Eran

    2016-09-15

    The genetics of the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) turn our attention to RNA metabolism, primarily because many of the identified diseases-associated genes encode for RNA-binding proteins. microRNAs (miRNAs) are endogenous noncoding RNAs that play critical roles in maintaining brain integrity. The current review sheds light on miRNA dysregulation in neurodegenerative diseases, focusing on FTD-ALS. We propose that miRNAs are susceptible to fail when protein factors that are critical for miRNA biogenesis malfunction. Accordingly, potential insufficiencies of the 'microprocessor' complex, the nucleo-cytoplasmic export of miRNA precursors or their processing by Dicer were recently reported. Furthermore, specific miRNAs are involved in the regulation of pathways that are essential for neuronal survival or function. Any change in the expression of these specific miRNAs or in their ability to recognize their target sequences will have negative consequences. Taken together, recent reports strengthens the hypothesis that dysregulation of miRNAs might play an important role in the pathogenesis of neurodegenerative diseases, and highlights the miRNA biogenesis machinery as an interesting target for therapeutic interventions for ALS as well as FTD. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease. PMID:26778173

  5. INTEGRAL TOO observations of MAXI J1659-152

    NASA Astrophysics Data System (ADS)

    Kuulkers, E.; Kouveliotou, C.; Chenevez, J.; van der Horst, A. J.

    2010-09-01

    INTEGRAL observed the recently discovered X-ray transient MAXI J1659-152 (Negoro et al. 2010, ATel #2873; Mangano et al. 2010, GCN #11296) from UT 27 September 19:04 to 29 September 2010 09:04 (i.e., simultaneous with the XMM-Newton observations, Kuulkers et al. 2010, ATel #2887) for a total exposure of 100 ksec. During the first ~58 ksec exposure the source was about 180 mCrab (20-40 keV) and 110 mCrab (40-80 keV) as seen with IBIS/ISGRI.

  6. High-pressure combinatorial process integrating hot isostatic pressing.

    PubMed

    Fujimoto, Kenjiro; Morita, Hiroki; Goshima, Yuji; Ito, Shigeru

    2013-12-01

    A high-pressure combinatorial process integrating hot isostatic pressing (HIP) was developed by providing a reaction vessel with a high-pressure tightness based on a commercial flange. The reaction vessel can be used up to 200 MPa and 500 °C under HIP processing condition. Preparation of spinel-type MgAl2O4 from Mg(OH)2, Al(OH)3 and AlOOH was performed using the reaction vessel under 200 MPa and 500 °C as demonstration. The entire powder library was characterized using powder X-ray diffraction patterns, and the single phase of spinel-type MgAl2O4 was obtained from Mg(OH)2+Al(OH)3. These assessments corresponded with previously published data. PMID:24168067

  7. Effects of the Al content on pore structures of porous TieAl alloys

    SciTech Connect

    Jiang, Y; He, Y H; Zou, J; Huang, B; Liu, C

    2008-01-01

    PorousTi Alalloys with different nominal compositions were fabricated through a reactive synthesis of Ti and Al elemental powders. It has been found that the pore parameters vary with the Al contents, indicating that the nature of the pores can be manipulated through changing the Al contents. In addition, detailed structural characterizations showed that the fabricated porousTi Alalloys can have three crystalline phases (i.e., 2-Ti3Al, -TiAl, and TiAl3) when using different compositions. The fundamental reasons behind these phenomena have been explored.

  8. Response to Signorovitch et al.

    PubMed

    Flot, Jean-François; Debortoli, Nicolas; Hallet, Bernard; Van Doninck, Karine

    2016-08-22

    Signorovitch et al.[1] comment that an Oenothera-like meiosis [2] could produce a pattern similar to what we observed in our study of natural isolates of the bdelloid rotifer Adineta vaga, which we attributed to horizontal gene transfers (HGTs) [3]. Indeed, our HGT hypothesis appears at first sight difficult to conciliate with their observation of a congruent pattern of allele sharing at four large loci possibly located on different chromosomes [4]. However, one might imagine conditions under which massive horizontal gene transfer between bdelloid individuals could produce such a pattern, notably if the individuals involved had previously lost most of their heterozygosity because of their exposure to frequent desiccation (which produces DNA double-strand breaks [5]). In the published A. vaga genome the loss of heterozygosity due to large-scale gene conversion events or break-induced replication covers only about 10% of the genome [6], but this percentage may be much higher in environmental isolates that often experience dessication. Besides, if an Oenothera-like mode of meiosis occurs in bdelloids frequently enough to be detected in a single sampling of 29 individuals (as in [4]), one would expect males and meiosis to be observed at least occasionally, and instances of congruent allele sharing across loci should turn up frequently in genetic surveys. This was not the case in [3]: among the 82 A. vaga individuals sequenced for four nuclear markers, no trio of individuals presented congruent patterns of shared sequences at different loci. For these reasons, and in the absence of any direct evidence for an Oenothera-like meiosis in bdelloids, we still consider inter-bdelloid HGTs a more parsimonious explanation for our results. PMID:27554651

  9. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions

    NASA Astrophysics Data System (ADS)

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-07-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits.

  10. Strengthening of Al and Al-Mg alloy wires by melt inoculation with Al/MgB2 nanocomposite

    NASA Astrophysics Data System (ADS)

    Florián-Algarín, David; Marrero, Raúl; Padilla, Alexandra; Suárez, Oscar Marcelo

    2015-12-01

    This study hinges on the feasibility of strengthening Al and Al-Mg wires by adding Al nanocomposite pellets containing MgB2 nanoparticles into the melt upon fabrication. These MgB2 nanoparticles were obtained by fragmentation using a high-energy ball mill, and were, afterward, mechanically alloyed with pure aluminum. The resulting MgB2/Al nanocomposite pellets were sintered at 260°C to be subsequently added into molten aluminum and an Al-Mg alloy melt. Cold rolling intercalated with stepwise annealing allowed the fabrication of 1 mm diameter wires with a final area reduction of 96%. Mechanical and physical properties of the treated wire specimens were compared to those of similarly processed pure aluminum wire. The ultimate tensile strength of the treated wires increased approximately double fold with respect to untreated wires at the expense of some loss in electrical conductivity.

  11. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions.

    PubMed

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-01-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits. PMID:27403611

  12. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions

    PubMed Central

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-01-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits. PMID:27403611

  13. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions.

    PubMed

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-07-12

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits.

  14. Two Related Parametric Integrals

    ERIC Educational Resources Information Center

    Dana-Picard, T.

    2007-01-01

    Two related sequences of definite integrals are considered. By mixing hand-work, computer algebra system assistance and websurfing, fine connections can be studied between integrals and a couple of interesting sequences of integers. (Contains 4 tables.)

  15. Integration in action.

    PubMed

    Green, Sara; Wolkenhauer, Olaf

    2012-09-01

    The workshop on 'Integration in Biology and Biomedicine' was held in May 2012 at the University of Sydney. It brought together scientists and philosophers to discuss the need for, and practice of, integration in the life sciences.

  16. Quality Integrated Education

    ERIC Educational Resources Information Center

    Brazziel, William

    1978-01-01

    Integrated education as it exists in many communities is actually harmful to black children and works to devastate rather than develop black talent; proponents of school integration must put effort into improving the quality of all schools. (JD)

  17. The universal path integral

    NASA Astrophysics Data System (ADS)

    Lloyd, Seth; Dreyer, Olaf

    2016-02-01

    Path integrals calculate probabilities by summing over classical configurations of variables such as fields, assigning each configuration a phase equal to the action of that configuration. This paper defines a universal path integral, which sums over all computable structures. This path integral contains as sub-integrals all possible computable path integrals, including those of field theory, the standard model of elementary particles, discrete models of quantum gravity, string theory, etc. The universal path integral possesses a well-defined measure that guarantees its finiteness. The probabilities for events corresponding to sub-integrals can be calculated using the method of decoherent histories. The universal path integral supports a quantum theory of the universe in which the world that we see around us arises out of the interference between all computable structures.

  18. Influence of AlN thickness on AlGaN epilayer grown by MOCVD

    NASA Astrophysics Data System (ADS)

    Jayasakthi, M.; Juillaguet, S.; Peyre, H.; Konczewicz, L.; Baskar, K.; Contreras, S.

    2016-10-01

    AlGaN/AlN layers were grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrates. The AlN buffer thickness was varied from 400 nm to 800 nm. The AlGaN layer thickness was 1000 nm. The crystalline quality, thickness and composition of AlGaN were determined using high resolution X-ray diffraction (HRXRD). The threading dislocation density (TDD) was found to decrease with increase of AlN layer thickness. Reciprocal space mapping (RSM) was used to estimate the strain and relaxation between AlGaN and AlN. The optical properties of AlGaN layers were investigated by temperature dependent photoluminescence (PL). PL intensities of AlGaN layers increases with increasing the AlN thickness. The surface morphology of AlGaN was studied by atomic force microscopy (AFM). Root mean square (RMS) roughness values were found to be decreased while increase of AlN thickness.

  19. Integrated optics technology study

    NASA Technical Reports Server (NTRS)

    Chen, B.; Findakly, T.; Innarella, R.

    1982-01-01

    The status and near term potential of materials and processes available for the fabrication of single mode integrated electro-optical components are discussed. Issues discussed are host material and orientation, waveguide formation, optical loss mechanisms, wavelength selection, polarization effects and control, laser to integrated optics coupling fiber optic waveguides to integrated optics coupling, sources, and detectors. Recommendations of the best materials, technology, and processes for fabrication of integrated optical components for communications and fiber gyro applications are given.

  20. Integrated optics technology study

    NASA Technical Reports Server (NTRS)

    Chen, B.

    1982-01-01

    The materials and processes available for the fabrication of single mode integrated electrooptical components are described. Issues included in the study are: (1) host material and orientation, (2) waveguide formation, (3) optical loss mechanisms, (4) wavelength selection, (5) polarization effects and control, (6) laser to integrated optics coupling,(7) fiber optic waveguides to integrated optics coupling, (8) souces, (9) detectors. The best materials, technology and processes for fabrication of integrated optical components for communications and fiber gyro applications are recommended.

  1. Boolean integral calculus

    NASA Technical Reports Server (NTRS)

    Tucker, Jerry H.; Tapia, Moiez A.; Bennett, A. Wayne

    1988-01-01

    The concept of Boolean integration is developed, and different Boolean integral operators are introduced. Given the changes in a desired function in terms of the changes in its arguments, the ways of 'integrating' (i.e. realizing) such a function, if it exists, are presented. The necessary and sufficient conditions for integrating, in different senses, the expression specifying the changes are obtained. Boolean calculus has applications in the design of logic circuits and in fault analysis.

  2. Multi-Objective Optimization in Hot Machining of Al/SiCp Metal Matrix Composites

    NASA Astrophysics Data System (ADS)

    Jadhav, M. R.; Dabade, U. A.

    2016-02-01

    Metal Matrix Composites (MMCs) have been found to be useful in a number of engineering applications and particle reinforced MMCs have received considerable attention due to their excellent engineering properties. These materials are generally regarded as extremely difficult to machine, because of the abrasive characteristics of the reinforced particulates. These characteristics of MMCs affect the machined surface quality and integrity. This paper presents use of Taguchi Grey Relational Analyses (GRA) for optimization of Al/SiCp/10p (220 and 600 mesh) MMCs produced by stir casting. Experiments are performed using L16 orthogonal array by using hot machining technique. The objective of this study is to identify the optimum process parameters to improve the surface integrity on Al/SiCp MMCs. The machined surface integrity has been analyzed by process parameters such as speed, feed, depth of cut and preheating temperature. The significance of the process parameters on surface integrity has been evaluated quantitatively by the analysis of variance (ANOVA) method and AOM plots. The grey relational analysis shows optimum machining conditions as 0.05 mm/rev feed, 0.4 mm depth of cut and 60 °C preheating temperature to enhance surface integrity for both Al/SiCp/10p (220 and 600 mesh) MMCs except for cutting speed 50 and 25 m/min respectively.

  3. Integrated Education. Feature Issue.

    ERIC Educational Resources Information Center

    York, Jennifer, Ed.; Vandercook, Terri, Ed.

    1988-01-01

    This "feature issue" provides various perspectives on a number of integrated education topics, including successful integration practices and strategies, the changing roles of teachers, the appropriate role of research, the history and future of integrated education, and the realization of dreams of life in the mainstream for children with severe…

  4. Sledge-Hammer Integration

    ERIC Educational Resources Information Center

    Ahner, Henry

    2009-01-01

    Integration (here visualized as a pounding process) is mathematically realized by simple transformations, successively smoothing the bounding curve into a straight line and the region-to-be-integrated into an area-equivalent rectangle. The relationship to Riemann sums, and to the trapezoid and midpoint methods of numerical integration, is…

  5. Social Integration and Divorce.

    ERIC Educational Resources Information Center

    Booth, Alan; And Others

    1991-01-01

    Longitudinal data on over 1,300 married persons suggest that divorce was deterred by absence of divorce in reference group (normative integration) and was deterred for shorter marriages by more friends and organizational affiliations (communicative integration). Sharing friends and organization affiliations with spouse (functional integration) may…

  6. Diana Al-Hadid: Identity and Heritage

    ERIC Educational Resources Information Center

    Jungerberg, Tom; Smith, Anna; Borsh, Colleen

    2012-01-01

    Diana Al-Hadid's sculptures reflect the many locations, cultures, histories, and mythologies that have shaped her as an artist. In large-scale works which have the appearance of architectural ruins, Al-Hadid employs imagery drawn from many diverse interests including science and technology, history, and literature. She also incorporates images and…

  7. Quantitatively Probing the Al Distribution in Zeolites

    SciTech Connect

    Vjunov, Aleksei; Fulton, John L.; Huthwelker, Thomas; Pin, Sonia; Mei, Donghai; Schenter, Gregory K.; Govind, Niranjan; Camaioni, Donald M.; Hu, Jian Z.; Lercher, Johannes A.

    2014-06-11

    The degree of substitution of Si4+ by Al3+ in the oxygen-terminated tetrahedra (Al T-sites) of zeolites determines the concentration of ion-exchange and Brønsted acid sites. As the location of the tetrahedra and the associated subtle variations in bond angles influence the acid strength, quantitative information about Al T-sites in the framework is critical to rationalize catalytic properties and to design new catalysts. A quantitative analysis is reported that uses a combination of extended X-ray absorption fine structure (EXAFS) analysis and 27Al MAS NMR spectroscopy supported by DFT-based molecular dynamics simulations. To discriminate individual Al atoms, sets of ab initio EXAFS spectra for various T-sites are generated from DFT-based molecular dynamics simulations allowing quantitative treatment of the EXAFS single- and multiple-photoelectron scattering processes out to 3-4 atom shells surrounding the Al absorption center. It is observed that identical zeolite types show dramatically different Al-distributions. A preference of Al for T-sites that are part of one or more 4-member rings in the framework over those T-sites that are part of only 5- and 6-member rings in the HBEA150 sample has been determined from a combination of these methods. This work was supported by the U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences.

  8. Durability Assessment of TiAl Alloys

    NASA Technical Reports Server (NTRS)

    Draper, Susan L.; Lerch, Bradley A.

    2008-01-01

    The durability of TiAl is a prime concern for the implementation of TiAl into aerospace engines. Two durability issues, the effect of high temperature exposure on mechanical properties and impact resistance, have been investigated and the results are summarized in this paper. Exposure to elevated temperatures has been shown to be detrimental to the room temperature ductility of gamma alloys with the most likely mechanisms being the ingress of interstitials from the surface. Fluorine ion implantation has been shown to improve the oxidation resistance of gamma alloys, and ideally it could also improve the environmental embrittlement of high Nb content TiAl alloys. The effect of F ion implantation on the surface oxidation and embrittlement of a third generation, high Nb content TiAl alloy (Ti-45Al-5Nb-B-C) were investigated. Additionally, the ballistic impact resistance of a variety of gamma alloys, including Ti-48Al-2Cr- 2Nb, Ti-47Al-2Cr-2Nb, ABB-2, ABB-23, NCG359E, 95A and Ti-45Al-5Nb-B-C was accessed. Differences in the ballistic impact properties of the various alloys will be discussed, particularly with respect to their manufacturing process, microstructure, and tensile properties.

  9. Energetics of Al13 Keggin cluster compounds

    PubMed Central

    Armstrong, Christopher R.; Casey, William H.; Navrotsky, Alexandra

    2011-01-01

    The ϵ-Al13 Keggin aluminum hydroxide clusters are essential models in establishing molecular pathways for geochemical reactions. Enthalpies of formation are reported for two salts of aluminum centered ϵ-Keggin clusters, Al13 selenate, (Na(AlO4)Al12(OH)24(SeO4)4•12H2O) and Al13 sulfate, (NaAlO4Al12(OH)24(SO4)4•12H2O). The measured enthalpies of solution, ΔHsol, at 28 °C in 5 N HCl for the ε-Al13 selenate and sulfate are −924.57 (± 3.83) and −944.30 ( ± 5.66) kJ·mol-1, respectively. The enthalpies of formation from the elements, ΔHf,el, for Al13 selenate and sulfate are −19,656.35 ( ± 67.30) kJ·mol-1, and −20,892.39 ( ± 70.01) kJ·mol-1, respectively. In addition, ΔHf,el for sodium selenate decahydrate was calculated using data from high temperature oxide melt solution calorimetry measurements: −4,006.39 ( ± 11.91) kJ·mol-1. The formation of both ε-Al13 Keggin cluster compounds is exothermic from oxide-based components but energetically unfavorable with respect to a gibbsite-based assemblage. To understand the relative affinity of the ϵ-Keggin clusters for selenate and sulfate, the enthalpy associated with two S-Se exchange reactions was calculated. In the solid state, selenium is favored in the Al13 compound relative to the binary chalcogenate, while in 5 N HCl, sulfur is energetically favored in the cluster compound compared to the aqueous solution. This contribution represents the first thermodynamic study of ε-Al13 cluster compounds and establishes a method for other such molecules, including the substituted versions that have been created for kinetic studies. Underscoring the importance of ε-Al13 clusters in natural and anthropogenic systems, these data provide conclusive thermodynamic evidence that the Al13 Keggin cluster is a crucial intermediate species in the formation pathway from aqueous aluminum monomers to aluminum hydroxide precipitates. PMID:21852572

  10. NiAl alloys for structural uses

    NASA Technical Reports Server (NTRS)

    Koss, D. A.

    1991-01-01

    Alloys based on the intermetallic compound NiAl are of technological interest as high temperature structural alloys. These alloys possess a relatively low density, high melting temperature, good thermal conductivity, and (usually) good oxidation resistance. However, NiAl and NiAl-base alloys suffer from poor fracture resistance at low temperatures as well as inadequate creep strength at elevated temperatures. This research program explored macroalloying additions to NiAl-base alloys in order to identify possible alloying and processing routes which promote both low temperature fracture toughness and high temperature strength. Initial results from the study examined the additions of Fe, Co, and Hf on the microstructure, deformation, and fracture resistance of NiAl-based alloys. Of significance were the observations that the presence of the gamma-prime phase, based on Ni3Al, could enhance the fracture resistance if the gamma-prime were present as a continuous grain boundary film or 'necklace'; and the Ni-35Al-20Fe alloy was ductile in ribbon form despite a microstructure consisting solely of the B2 beta phase based on NiAl. The ductility inherent in the Ni-35Al-20Fe alloy was explored further in subsequent studies. Those results confirm the presence of ductility in the Ni-35Al-20Fe alloy after rapid cooling from 750 - 1000 C. However exposure at 550 C caused embrittlement; this was associated with an age-hardening reaction caused by the formation of Fe-rich precipitates. In contrast, to the Ni-35Al-20Fe alloy, exploratory research indicated that compositions in the range of Ni-35Al-12Fe retain the ordered B2 structure of NiAl, are ductile, and do not age-harden or embrittle after thermal exposure. Thus, our recent efforts have focused on the behavior of the Ni-35Al-12Fe alloy. A second parallel effort initiated in this program was to use an alternate processing technique, mechanical alloying, to improve the properties of NiAl-alloys. Mechanical alloying in the

  11. Corrosion Studies of 2195 Al-Li Alloy and 2219 Al Alloy with Differing Surface Treatments

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Mendrek, M. J.

    1998-01-01

    Corrosion studies of 2195 Al-Li and 2219 Al alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of Al203 blasted, soda blasted and conversion coated 2219 Al were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.

  12. Photonic Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Merritt, Scott; Krainak, Michael

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  13. Consolidation of Al2O3/Al Nanocomposite Powder by Cold Spray

    NASA Astrophysics Data System (ADS)

    Poirier, Dominique; Legoux, Jean-Gabriel; Drew, Robin A. L.; Gauvin, Raynald

    2011-01-01

    While the improvement in mechanical properties of nanocomposites makes them attractive materials for structural applications, their processing still presents significant challenges. In this article, cold spray was used to consolidate milled Al and Al2O3/Al nanocomposite powders as well as the initial unmilled and unreinforced Al powder. The microstructure and nanohardness of the feedstock powders as well as those of the resulting coatings were compared. The results show that the large increase in hardness of the Al powder after mechanical milling is preserved after cold spraying. Good quality coating with low porosity is obtained from milled Al. However, the addition of Al2O3 to the Al powder during milling decreases the powder and coating nanohardness. This lower hardness is attributed to non-optimized milling parameters leading to cracked particles with insufficient Al2O3 embedding in Al. The coating produced from the milled Al2O3/Al mixture also showed lower particle cohesion and higher amount of porosity.

  14. Modeling of K-Shell Al and Mg and L-Shell Mo Radiation from Compact Cylindrical Wire Array Plasmas Produced on the 1 MA UNR Zebra Generator

    SciTech Connect

    Yilmaz, M. F.; Safronova, A. S.; Esaulov, A. A.; Kantsyrev, V. L.; Quart, N. D.; Williamson, K. M.; Shrestha, I.

    2009-01-21

    K-shell radiation of Al and Mg and L-shell radiation of Mo from implosions of compact cylindrical wire arrays (CCWA) on the 1 MA UNR Zebra generator was studied. Specifically, radiation from implosions of 3 and 6 mm CCWA with (16-24) Al-5052 (95% Al and 5% Mg) and Al-5052 (97.5% Al and 2.5% Mg) and Mo wires was analyzed using the full set of diagnostics: PCD and current signals, and X-ray pinhole images and spectra. Previously developed non-LTE models were applied to model spatially resolved time integrated as well as time-gated spatially integrated spectra from Al, Mg, and Mo plasmas. Derived electron temperature and density spatial gradients as well as percentage of radiating mass were studied and compared. In addition, the novel Wire Dynamics Model (WDM) was used to analyze the implosion dynamics of compact wire array loads.

  15. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    NASA Astrophysics Data System (ADS)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    one can generalize or adapt this construction to different settings like the integro-differential, discrete or super-symmetric ones. The emphasis is usually to find auxiliary linear systems defining an infinite set of linear commuting flows whose solutions, if some asymptotic conditions are imposed, are named wave or Baker-Akhiezer functions. These linear flows determine the so called Lax equations, another infinite set of commuting equations whose compatibility leads to the so called Zakharov-Shabat system. An alternative description of the hierarchies is achieved with the use of the bilinear equations directly linked with the tau-function description of the hierarchy. There are two paradigmatic integrable hierarchies, namely the KP and 2-dimensional Toda lattice (2DTL). These hierarchies are treated within this volume in three contributions. In particular, Takasaki [5] reconsiders the extended Toda hierarchy of Carlet, Dubrovin and Zhang in the light of Ogawa's 2 + 1D extension of the 1D Toda hierarchy. It turns out that the former may be thought of as some sort of dimensional reduction of the latter. This explains the structure of the bilinear formalism proposed by Milanov. Carlet and Manas [6] study the 2-component KP and 2D Toda hierarchies and solve explicitly several implicit constraints present in the usual Lax formulation of the hierarchy, thus identifying a set of free dependent variables for such hierarchies. Finally, the KP hierarchy is considered in the paper by Lin et al [7], which explores the extended flows of a q-deformed modified KP hierarchy leading to the introduction of self-consistent sources. By a combination of the dressing method and the method of variation of constants, the authors are able through a dressing approach to find a scheme for the construction of solutions of the corresponding integrable equations with self-consistent sources. The study of dispersionless integrable hierarchies is an active field of research, and this special issue

  16. Development of Advanced Tools for Cryogenic Integration

    NASA Astrophysics Data System (ADS)

    Bugby, D. C.; Marland, B. C.; Stouffer, C. J.; Kroliczek, E. J.

    2004-06-01

    This paper describes four advanced devices (or tools) that were developed to help solve problems in cryogenic integration. The four devices are: (1) an across-gimbal nitrogen cryogenic loop heat pipe (CLHP); (2) a miniaturized neon CLHP; (3) a differential thermal expansion (DTE) cryogenic thermal switch (CTSW); and (4) a dual-volume nitrogen cryogenic thermal storage unit (CTSU). The across-gimbal CLHP provides a low torque, high conductance solution for gimbaled cryogenic systems wishing to position their cryocoolers off-gimbal. The miniaturized CLHP combines thermal transport, flexibility, and thermal switching (at 35 K) into one device that can be directly mounted to both the cooler cold head and the cooled component. The DTE-CTSW, designed and successfully tested in a previous program using a stainless steel tube and beryllium (Be) end-pieces, was redesigned with a polymer rod and high-purity aluminum (Al) end-pieces to improve performance and manufacturability while still providing a miniaturized design. Lastly, the CTSU was designed with a 6063 Al heat exchanger and integrally welded, segmented, high purity Al thermal straps for direct attachment to both a cooler cold head and a Be component whose peak heat load exceeds its average load by 2.5 times. For each device, the paper will describe its development objective, operating principles, heritage, requirements, design, test data and lessons learned.

  17. Japanese version of the ALS-FTD-Questionnaire (ALS-FTD-Q-J).

    PubMed

    Watanabe, Yasuhiro; Beeldman, Emma; Raaphorst, Joost; Izumi, Yuishin; Yoshino, Hiide; Masuda, Michihito; Atsuta, Naoki; Ito, Satoru; Adachi, Tadashi; Adachi, Yoshiki; Yokota, Osamu; Oda, Masaya; Hanashima, Ritsuko; Ogino, Mieko; Ichikawa, Hiroo; Hasegawa, Kazuko; Kimura, Hideki; Shimizu, Toshio; Aiba, Ikuko; Yabe, Hayato; Kanba, Makoto; Kusumi, Kimiyoshi; Aoki, Tetsuya; Hiroe, Yu; Watanabe, Hirohisa; Nishiyama, Kazutoshi; Nomoto, Masahiro; Sobue, Gen; Nakashima, Kenji

    2016-08-15

    Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share common clinical, genetic and neuropathological features. Some ALS patients have behavioral/personality changes, which could result in significant obstacles in the care provided by family members and caregivers. An easy screening tool would contribute greatly to the evaluation of these symptoms. We translated the ALS-FTD-Questionnaire, developed in the Netherlands, into Japanese (ALS-FTD-Q-J) and examined the clinimetric properties (internal consistency, construct and clinical validity). Patients with ALS and/or behavioral variant FTD (bvFTD) were evaluated alongside healthy controls in this multicenter study. All ALS patients, regardless of bvFTD status, were further evaluated by the frontal behavioral inventory (FBI) and for frontal/executive function, cognition, anxiety/depression, and motor functions. Data from 146 subjects were analyzed: ALS (92), ALS-bvFTD (6), bvFTD (16), and healthy controls (32). The internal consistency of the ALS-FTD-Q-J was good (Cronbach α=0.92). The ALS-FTD-Q-J showed construct validity as it exhibited a high correlation with the FBI (r=0.79). However, correlations were moderate with anxiety/depression and low with cognitive scales, in contrast to the original report, i.e. a moderate correlation with cognition and a low correlation with anxiety/depression. The ALS-FTD-Q-J discriminated ALS patients from (ALS-)bvFTD patients and controls. Thus, the ALS-FTD-Q-J is useful for evaluating Japanese ALS/FTD patients.

  18. Japanese version of the ALS-FTD-Questionnaire (ALS-FTD-Q-J).

    PubMed

    Watanabe, Yasuhiro; Beeldman, Emma; Raaphorst, Joost; Izumi, Yuishin; Yoshino, Hiide; Masuda, Michihito; Atsuta, Naoki; Ito, Satoru; Adachi, Tadashi; Adachi, Yoshiki; Yokota, Osamu; Oda, Masaya; Hanashima, Ritsuko; Ogino, Mieko; Ichikawa, Hiroo; Hasegawa, Kazuko; Kimura, Hideki; Shimizu, Toshio; Aiba, Ikuko; Yabe, Hayato; Kanba, Makoto; Kusumi, Kimiyoshi; Aoki, Tetsuya; Hiroe, Yu; Watanabe, Hirohisa; Nishiyama, Kazutoshi; Nomoto, Masahiro; Sobue, Gen; Nakashima, Kenji

    2016-08-15

    Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share common clinical, genetic and neuropathological features. Some ALS patients have behavioral/personality changes, which could result in significant obstacles in the care provided by family members and caregivers. An easy screening tool would contribute greatly to the evaluation of these symptoms. We translated the ALS-FTD-Questionnaire, developed in the Netherlands, into Japanese (ALS-FTD-Q-J) and examined the clinimetric properties (internal consistency, construct and clinical validity). Patients with ALS and/or behavioral variant FTD (bvFTD) were evaluated alongside healthy controls in this multicenter study. All ALS patients, regardless of bvFTD status, were further evaluated by the frontal behavioral inventory (FBI) and for frontal/executive function, cognition, anxiety/depression, and motor functions. Data from 146 subjects were analyzed: ALS (92), ALS-bvFTD (6), bvFTD (16), and healthy controls (32). The internal consistency of the ALS-FTD-Q-J was good (Cronbach α=0.92). The ALS-FTD-Q-J showed construct validity as it exhibited a high correlation with the FBI (r=0.79). However, correlations were moderate with anxiety/depression and low with cognitive scales, in contrast to the original report, i.e. a moderate correlation with cognition and a low correlation with anxiety/depression. The ALS-FTD-Q-J discriminated ALS patients from (ALS-)bvFTD patients and controls. Thus, the ALS-FTD-Q-J is useful for evaluating Japanese ALS/FTD patients. PMID:27423564

  19. Selective layer disordering in intersubband Al0.028Ga0.972 N/AlN superlattices with silicon nitride capping layer

    DOE PAGES

    Wierer, Jonathan J.; Allerman, Andrew A.; Skogen, Erik J.; Tauke-Pedretti, Anna; Vawter, Gregory A.; Montaño, Ines

    2015-06-01

    We demonstrate the selective layer disordering in intersubband Al0.028Ga0.972 N/AlN superlattices using a silicon nitride (SiNx) capping layer. The (SiNx) capped superlattice exhibits suppressed layer disordering under high-temperature annealing. In addition, the rate of layer disordering is reduced with increased SiNx thickness. The layer disordering is caused by Si diffusion, and the SiNx layer inhibits vacancy formation at the crystal surface and ultimately, the movement of Al and Ga atoms across the heterointerfaces. In conclusion, patterning of the SiNx layer results in selective layer disordering, an attractive method to integrate active and passive III–nitride-based intersubband devices.

  20. Selective layer disordering in intersubband Al0.028Ga0.972N/AlN superlattices with silicon nitride capping layer

    NASA Astrophysics Data System (ADS)

    Wierer, Jonathan J., Jr.; Allerman, Andrew A.; Skogen, Erik J.; Tauke-Pedretti, Anna; Vawter, Gregory A.; Montaño, Ines

    2015-06-01

    Selective layer disordering in an intersubband Al0.028Ga0.972N/AlN superlattice using a silicon nitride (SiNx) capping layer is demonstrated. The SiNx capped superlattice exhibits suppressed layer disordering under high-temperature annealing. Additionally, the rate of layer disordering is reduced with increased SiNx thickness. The layer disordering is caused by Si diffusion, and the SiNx layer inhibits vacancy formation at the crystal surface and ultimately, the movement of Al and Ga atoms across the heterointerfaces. Patterning of the SiNx layer results in selective layer disordering, an attractive method to integrate active and passive III-nitride-based intersubband devices.

  1. A new discontinuously reinforced aluminum MMC: Al+AlB{sub 2} flakes

    SciTech Connect

    HALL,AARON C.; ECONOMY,J.

    2000-06-08

    Development of a novel metal matrix composite based on the Al-B alloy system has been undertaken. Preparation of this discontinuously reinforced material is based on the precipitation of high aspect ratio AlB{sub 2} from an Al-B alloy. This paper describes a number of efforts forced on preparing high volume fractions (> 30 v%) of AlB{sub 2} in aluminum. New insights into the behavior of the Al-B alloys system allowed this effort to be successful.

  2. Atomistic Modeling of RuAl and (RuNi) Al Alloys

    NASA Technical Reports Server (NTRS)

    Gargano, Pablo; Mosca, Hugo; Bozzolo, Guillermo; Noebe, Ronald D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Atomistic modeling of RuAl and RuAlNi alloys, using the BFS (Bozzolo-Ferrante-Smith) method for alloys is performed. The lattice parameter and energy of formation of B2 RuAl as a function of stoichiometry and the lattice parameter of (Ru(sub 50-x)Ni(sub x)Al(sub 50)) alloys as a function of Ni concentration are computed. BFS based Monte Carlo simulations indicate that compositions close to Ru25Ni25Al50 are single phase with no obvious evidence of a miscibility gap and separation of the individual B2 phases.

  3. Effects of hydrogen absorption in TbNiAl and UNiAl

    SciTech Connect

    Bordallo, H.N.; Nakotte, H.; Schultz, A.; Kolomiets, A.V.; Havela, L.; Andreev, A.V.

    1998-12-31

    Although hydrides of intermetallic compounds are used extensively as hydrogen-storage media, little is known about the exact nature of metal-hydrogen interactions. However, this knowledge is of essential importance for the understanding of thermodynamics and other properties. Hydrides (deuterides) of TbNiAl and UNiAl have been widely studied because of drastic increase of magnetic ordering temperature under hydrogenation. Here the authors report neutron-diffraction results of the three deuterides, TbNiAlD{sub 1.28}, TbNiAlD{sub 0.8}a nd UNiAlD{sub 2.23}.

  4. Misconceptions and Integration

    PubMed Central

    MORTAZ HEJRI, SARA; MIRZAZADEH, AZIM; JALILI, MOHAMMAD

    2015-01-01

    Introduction Pervasive beliefs regarding curricular reform and integration have flourished among medical students, faculty members and medical school administrators. These concepts have extensively impacted the reform process, sometimes by resisting the reforms and sometimes by diverting the curriculum from its planned objectives. In the current paper, we have tried to address the challenges of integration in MD program by looking at the existing literature and the experience of the international universities. Methods We collected the questions frequently asked during the curricular reform process. We, then, evaluated them, and selected 5 main ideas. In order to find their answers, we searched the literature using these keywords: integration, reform, and undergraduate medical curriculum. Results The findings are discussed in five sections: 1) Reform is not equivalent to integration, 2) Integration can be implemented in both high school and graduate programs, 3) Organ-system based integration is not the only method available for integration, 4) Integration of two phases (basic sciences and physiopathology) can be considered but it is not mandatory, 5) Integration does not fade basic sciences in favor of clinical courses. Conclusion It seems that medical education literature and prior experience of the leading universities do not support most of the usual concepts about integration. Therefore, it is important to consider informed decision making based on best evidence rather than personal opinions during the curricular reform process. PMID:26457318

  5. Arsenate uptake by Al nanoclusters and other Al-based sorbents during water treatment.

    PubMed

    Mertens, Jasmin; Rose, Jérôme; Wehrli, Bernhard; Furrer, Gerhard

    2016-01-01

    In many parts of the world, arsenic from geogenic and anthropogenic sources deteriorates the quality of drinking water resources. Effective methods of arsenic removal include adsorption and coagulation with iron- and aluminum-based materials, of which polyaluminum chloride is widely employed as coagulant in water treatment due to its low cost and high efficiency. We compared the arsenic uptake capacity and the arsenic bonding sites of different Al-based sorbents, including Al nanoclusters, polyaluminum chloride, polyaluminum granulate, and gibbsite. Extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that As(V) forms bidentate-binuclear complexes in interaction with all Al-based removal agents. The octahedral configuration of nanoclusters and the distribution of sorption sites remain the same in all types of removal agents consisting of nano-scale Al oxyhydroxide particles. The obtained distances for As(V)-O and As(V)-Al agreed with previously published data and were found to be 1.69 ± 0.02 Å and 3.17-3.21 Å, respectively. Our study suggests that As(V) binds to Al nanoclusters as strongly as to Al oxide surfaces. The As sorption capacity of Al nanoclusters was found to be very similar to that of Al clusters in a polyaluminum chloride. The most efficient Al-based sorbents for arsenic removal were Al nanoclusters, followed by polyaluminum granulate. PMID:26613179

  6. Hybrid Al + Al3Ni metallic foams synthesized in situ via laser engineered net shaping

    NASA Astrophysics Data System (ADS)

    Zheng, Baolong; Li, Ying; Smugeresky, John E.; Zhou, Yizhang; Baker, Dean; Lavernia, Enrique J.

    2011-09-01

    A hybrid, Al + Al3Ni metallic foam was synthesized in situ via laser engineered net shaping (LENS®) of Ni-coated 6061 Al powder in the absence of a foaming agent. During LENS® processing, the Ni coating reacted with the Al matrix, resulting in the simultaneous formation of a fine dispersion of Al3Ni, and a high volume fraction of porosity. As a reinforcement phase, the intermetallic compound formed particles with a size range of 1-5 µm and a volume fraction of 63%, with accompanying 35-300 µm pores with a 60% volume fraction. The microstructure of the as-deposited Al + Al3Ni composite foams was characterized using SEM, EDS, XRD and TEM/HRTEM techniques. The evolution of the microstructure was analyzed on the basis of the thermal field present during deposition, paying particular attention to the thermodynamics of the Al3Ni intermetallic compound formation as well as discussing the mechanisms that may be responsible for the observed porosity. The mechanical behavior of the as-deposited material was characterized using compression and microhardness testing, indicating that the yield strength and hardness are 190 MPa and 320 HV, respectively, which represents an increase of over three times higher than that of annealed Al6061, or similar to heat-treated Al6061 fully dense matrix, and much higher than those of traditional Al alloy foams, and with a low density of 1.64 g/m3.

  7. Reply to comment on "Validation of two innovative methods to measure contaminant mass flux in groundwater" by Goltz et al. (2009)

    NASA Astrophysics Data System (ADS)

    Goltz, Mark N.; Huang, Junqi

    2014-12-01

    We thank Sun (2014) for his comment on our paper, Goltz et al. (2009). The commenter basically makes two points: (1) equation (6) in Goltz et al. (2009) is incorrect, and (2) screen loss should be further considered as a source of error in the modified integral pump test (MIPT) experiment. We will address each of these points, below.

  8. Ni{sub 3}Al aluminide alloys

    SciTech Connect

    Liu, C.T.

    1993-10-01

    This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

  9. InAlN/AlN/GaN heterostructures for high electron mobility transistors

    NASA Astrophysics Data System (ADS)

    Usov, S. O.; Sakharov, A. V.; Tsatsulnikov, A. F.; Lundin, V. W.; Zavarin, E. E.; Nikolaev, A. E.; Yagovkina, M. A.; Zemlyakov, V. E.; Egorkin, V. I.; Ustinov, V. M.

    2016-08-01

    The results of development of InAlN/AlN/GaN heterostructures, grown on sapphire substrates by metal-organic chemical vapour deposition, and high electron mobility transistors (HEMTs) based on them are presented. The dependencies of the InAlN/AlN/GaN heterostructure properties on epitaxial growth conditions were investigated. The optimal indium content and InAlN barrier layer thicknesses of the heterostructures for HEMT s were determined. The possibility to improve the characteristics of HEMTs by in-situ passivation by Si3N4 thin protective layer deposited in the same epitaxial process was demonstrated. The InAlN/AlN/GaN heterostructure grown on sapphire substrate with diameter of 100 mm were obtained with sufficiently uniform distribution of sheet resistance. The HEMTs with saturation current of 1600 mA/mm and transconductance of 230 mS/mm are demonstrated.

  10. A Rechargeable Al/S Battery with an Ionic-Liquid Electrolyte.

    PubMed

    Gao, Tao; Li, Xiaogang; Wang, Xiwen; Hu, Junkai; Han, Fudong; Fan, Xiulin; Suo, Liumin; Pearse, Alex J; Lee, Sang Bok; Rubloff, Gary W; Gaskell, Karen J; Noked, Malachi; Wang, Chunsheng

    2016-08-16

    Aluminum metal is a promising anode material for next generation rechargeable batteries owing to its abundance, potentially dendrite-free deposition, and high capacity. The rechargeable aluminum/sulfur (Al/S) battery is of great interest owing to its high energy density (1340 Wh kg(-1) ) and low cost. However, Al/S chemistry suffers poor reversibility owing to the difficulty of oxidizing AlSx . Herein, we demonstrate the first reversible Al/S battery in ionic-liquid electrolyte with an activated carbon cloth/sulfur composite cathode. Electrochemical, spectroscopic, and microscopic results suggest that sulfur undergoes a solid-state conversion reaction in the electrolyte. Kinetics analysis identifies that the slow solid-state sulfur conversion reaction causes large voltage hysteresis and limits the energy efficiency of the system.

  11. High performance AlGaN/GaN HEMTs with AlN/SiNx passivation

    NASA Astrophysics Data System (ADS)

    Xin, Tan; Yuanjie, Lü; Guodong, Gu; Li, Wang; Shaobo, Dun; Xubo, Song; Hongyu, Guo; Jiayun, Yin; Shujun, Cai; Zhihong, Feng

    2015-07-01

    AlGaN/GaN high electron-mobility transistors (HEMTs) with 5 nm AlN passivation by plasma enhanced atomic layer deposition (PEALD) were fabricated, covered by 50 nm SiNx which was grown by plasma enhanced chemical vapor deposition (PECVD). With PEALD AlN passivation, current collapse was suppressed more effectively and the devices show better subthreshold characteristics. Moreover, the insertion of AlN increased the RF transconductance, which lead to a higher cut-off frequency. Temperature dependence of DC characteristics demonstrated that the degradations of drain current and maximum transconductance at elevated temperatures for the AlN/SiNx passivated devices were much smaller compared with the devices with SiNx passivation, indicating that PEALD AlN passivation can improve the high temperature operation of the AlGaN/GaN HEMTs. Project supported by the National Natural Science Foundation of China (No. 60890192).

  12. A Rechargeable Al/S Battery with an Ionic-Liquid Electrolyte.

    PubMed

    Gao, Tao; Li, Xiaogang; Wang, Xiwen; Hu, Junkai; Han, Fudong; Fan, Xiulin; Suo, Liumin; Pearse, Alex J; Lee, Sang Bok; Rubloff, Gary W; Gaskell, Karen J; Noked, Malachi; Wang, Chunsheng

    2016-08-16

    Aluminum metal is a promising anode material for next generation rechargeable batteries owing to its abundance, potentially dendrite-free deposition, and high capacity. The rechargeable aluminum/sulfur (Al/S) battery is of great interest owing to its high energy density (1340 Wh kg(-1) ) and low cost. However, Al/S chemistry suffers poor reversibility owing to the difficulty of oxidizing AlSx . Herein, we demonstrate the first reversible Al/S battery in ionic-liquid electrolyte with an activated carbon cloth/sulfur composite cathode. Electrochemical, spectroscopic, and microscopic results suggest that sulfur undergoes a solid-state conversion reaction in the electrolyte. Kinetics analysis identifies that the slow solid-state sulfur conversion reaction causes large voltage hysteresis and limits the energy efficiency of the system. PMID:27417442

  13. Fabrication and characterization of all-refractory NbCN/Al/AlO(x)/Al/Nb junctions

    NASA Astrophysics Data System (ADS)

    Barber, Z. H.; Blamire, M. G.; Somekh, R. E.; Evetts, J. E.

    1993-03-01

    High-quality AlO(x) tunnel barriers have been fabricated on epitaxial niobium carbonitride (NbCN) base layers by the deposition of an Al layer followed by thermal oxidation. By careful control of its uniformity, the thickness of the Al layer has been reduced to less than 3 nm, which results in an average gap voltage, Vg(NbCN), of up to 2.65 mV. Using a self-aligned whole-wafer processing route, high-quality NbCN/Al/AlO(x)/Al/Nb junctions as small as 0.6 sq mm have been made. These junctions offer considerable advantages over directly deposited barriers in terms of minimal subgap leakage, good control of the barrier conductance, and simple processing procedures. It was shown that submicron junctions can be fabricated with no gap smearing or reduction in quality. Using only Nb counterelectrodes total gap voltages up to 4.0 mV, with widths of 0.6 mV, have been demonstrated in high-quality junctions.

  14. Characterization of AlInN/AlN/GaN Heterostructures with Different AlN Buffer Thickness

    NASA Astrophysics Data System (ADS)

    Çörekçi, S.; Dugan, S.; Öztürk, M. K.; Çetin, S. Ş.; Çakmak, M.; Özçelik, S.; Özbay, E.

    2016-07-01

    Two AlInN/AlN/GaN heterostructures with 280-nm- and 400-nm-thick AlN buffer grown on sapphire substrates by metal-organic chemical vapor deposition (MOCVD) have been investigated by x-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL) and Hall-effect measurements. The symmetric (0002) plane with respect to the asymmetric (10bar{1}2) plane in the 280-nm-thick AlN buffer has a higher crystal quality, as opposed to the 400-nm-thick buffer. The thinner buffer improves the crystallinity of both (0002) and (10bar{1}2) planes in the GaN layers, it also provides a sizeable reduction in dislocation density of GaN. Furthermore, the lower buffer thickness leads to a good quality surface with an rms roughness of 0.30 nm and a dark spot density of 4.0 × 108 cm-2. The optical and transport properties of the AlInN/AlN/GaN structure with the relatively thin buffer are compatible with the enhancement in its structural quality, as verified by XRD and AFM results.

  15. Porous silicon bulk acoustic wave resonator with integrated transducer

    PubMed Central

    2012-01-01

    We report that porous silicon acoustic Bragg reflectors and AlN-based transducers can be successfully combined and processed in a commercial solidly mounted resonator production line. The resulting device takes advantage of the unique acoustic properties of porous silicon in order to form a monolithically integrated bulk acoustic wave resonator. PMID:22776697

  16. The Effect of Occlusion on Motion Integration in Infants

    ERIC Educational Resources Information Center

    Otsuka, Yumiko; Konishi, Yukuo; Kanazawa, So; Yamaguchi, Masami K.

    2009-01-01

    Previous psychophysical studies have shown that the adult human visual system makes use of form information such as occlusion to determine whether to integrate or segregate local motion signals (J. McDermott, Y. Weiss, & E. H. Adelson, 2001). Using the displays developed by McDermott et al., these experiments examined whether occlusion and amodal…

  17. III-V semiconductor devices integrated with silicon III-V semiconductor devices integrated with silicon

    NASA Astrophysics Data System (ADS)

    Hopkinson, Mark; Martin, Trevor; Smowton, Peter

    2013-09-01

    The integration of III-V semiconductor devices with silicon is one of the most topical challenges in current electronic materials research. The combination has the potential to exploit the unique optical and electronic functionality of III-V technology with the signal processing capabilities and advanced low-cost volume production techniques associated with silicon. Key industrial drivers include the use of high mobility III-V channel materials (InGaAs, InAs, InSb) to extend the performance of Si CMOS, the unification of electronics and photonics by combining photonic components (GaAs, InP) with a silicon platform for next-generation optical interconnects and the exploitation of large-area silicon substrates and high-volume Si processing capabilities to meet the challenges of low-cost production, a challenge which is particularly important for GaN-based devices in both power management and lighting applications. The diverse nature of the III-V and Si device approaches, materials technologies and the distinct differences between industrial Si and III-V processing have provided a major barrier to integration in the past. However, advances over the last decade in areas such as die transfer, wafer fusion and epitaxial growth have promoted widespread renewed interest. It is now timely to bring some of these topics together in a special issue covering a range of approaches and materials providing a snapshot of recent progress across the field. The issue opens a paper describing a strategy for the epitaxial integration of photonic devices where Kataria et al describe progress in the lateral overgrowth of InP/Si. As an alternative, Benjoucef and Reithmaier report on the potential of InAs quantum dots grown direct onto Si surfaces whilst Sandall et al describe the properties of similar InAs quantum dots as an optical modulator device. As an alternative to epitaxial integration approaches, Yokoyama et al describe a wafer bonding approach using a buried oxide concept, Corbett

  18. Interdiffusion in Diffusion Couples: U-Mo v. Al and Al-Si

    SciTech Connect

    D. D. Keiser, Jr.; E. Perez; B. Yao; Y. H. Sohn

    2009-11-01

    Interdiffusion and microstructural development in the U-Mo-Al system was examined using solid-tosolid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, annealed at 600°C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in Al on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, Al-2wt.%Si, and Al-5wt.%Si annealed at 550°C up to 20 hours. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase intermetallic layer. In ternary U-Mo-Al diffusion couples annealed at 600°C for 24 hours, interdiffusion microstructure varied of finely dispersed UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases while the average composition throughout the interdiffusion zone remained constant at approximately 80 at.% Al. Interdiffusion microstructure observed by SEM/TEM analyses and diffusion paths drawn from concentration profiles determined by EPMA appear to deviate from the assumption of “local thermodynamic equilibrium,” and suggest that interdiffusion occurs via supersaturated UAl4 followed by equilibrium transformation into UAl3, U6Mo4Al43, UAl4 and UMo2Al20 phases. Similar observation was made for U-Mo vs. Al diffusion couples annealed at 550°C. The addition of Si (up to 5 wt.%) in Al significantly reduced the thickness of the intermetallic layer by changing the constituent phases of the interdiffusion zone developed in U-Mo vs. Al-Si diffusion couples. Specifically, the formation of (U,Mo)(Al,Si)3 with relatively large solubility for Mo and Si, along with UMo2Al20 phases was observed along with disappearance of U6Mo4Al43 and UAl4 phases. Simplified understanding based on U-Al, U-Si, and Mo-Si binary phase diagrams is discussed in the light of the beneficial effect of Si alloying addition.

  19. A review of path-independent integrals in elastic-plastic fracture mechanics, task 4

    NASA Technical Reports Server (NTRS)

    Kim, K. S.

    1985-01-01

    The path independent (P-I) integrals in elastic plastic fracture mechanics which have been proposed in recent years to overcome the limitations imposed on the J integral are reviewed. The P-I integrals considered herein are the J integral by Rice, the thermoelastic P-I integrals by Wilson and Yu and by Gurtin, the J* integral by Blackburn, the J sub theta integral by Ainsworth et al., the J integral by Kishimoto et al., and the delta T sub p and delta T* sub p integrals by Atluri et al. The theoretical foundation of these P-I integrals is examined with emphasis on whether or not path independence is maintained in the presence of nonproportional loading and unloading in the plastic regime, thermal gradients, and material inhomogeneities. The similarities, differences, salient features, and limitations of these P-I integrals are discussed. Comments are also made with regard to the physical meaning, the possibility of experimental measurement, and computational aspects.

  20. New integral equation for simple fluids

    NASA Astrophysics Data System (ADS)

    Kang, Hong Seok; Ree, Francis H.

    1995-09-01

    We present a new integral equation for the radial distribution function of classical fluids. It employs the bridge function for a short-range repulsive reference system which was used earlier in our dense fluid perturbation theory. The bridge function is evaluated using Ballone et al.'s closure relation. Applications of the integral equation to the Lennard-Jones and inverse nth-power (n=12, 9, 6, and 4) repulsive systems show that it can predict thermodynamic and structural properties in close agreement with results from computer simulations and the reference-hypernetted-chain equation. We also discuss thermodynamic consistency tests on the new equation and comparisons with the integral equations of Rogers and Young and of Zerah and Hansen. The present equation has no parameter to adjust. This unique feature offers a significant advantage as it eliminates a time-consuming search to optimize such parameters appearing in other theories. It permits practical applications needing complex intermolecular potentials and for multicomponent systems.

  1. Faces of integration

    PubMed Central

    Williams, Paul; Sullivan, Helen

    2009-01-01

    Theme Two central themes permeate this paper—the interplay between structure and agency in integration processes and the extent to which this is mediated through sensemaking by individual actors. Case study The empirical base for the paper is provided by case study research from Wales which draws on examples of different types of integration in health and social care. The individual case studies highlight different interpretations of integration set against a background of the resources involved, processes employed and outcomes achieved. Discussion A wide ranging discussion exposes the complex interplay and dynamics between structural factors and the manner in which they enable or constrain integration, and individual actors realising their potential agency through leadership, professionalism and boundary spanning to influence outcomes. The importance of structure and agency complementing each other to determine effective integration is emphasised, together with the scope that is available for interpretation and meaning by individual actors within the contested discourse of integration. PMID:20087420

  2. Smoking Tied to Shorter Survival with ALS

    MedlinePlus

    ... with ALS between 2007 and 2011 in northern Italy. They also looked at chronic lung disease (COPD) ... of neuroscience at the University of Turin in Italy, led the study. SOURCE: BMJ , news release, Sept. ...

  3. Stem Cells Deemed Safe for ALS Patients

    MedlinePlus

    ... baby step forward," said lead researcher Dr. Jonathan Glass, of Emory University, in Atlanta. "We can say this procedure is doable in ALS patients," Glass said. "Now we have to test whether it's ...

  4. Glial cells in ALS: the missing link?

    PubMed

    Raibon, Elsa; Todd, Lisa Marie; Möller, Thomas

    2008-08-01

    Amyotrophic lateral sclerosis (ALS) was initially known as Charcot's sclerosis, named after the French neurobiologist and physician Jean-Martin Charcot who first described this type of muscular atrophy in the early nineteenth century. In the United States, ALS became widely known as Lou Gehrig's disease after the famous baseball player who succumbed to the disease in the late 1930s. Currently, ALS is the most common motor neuron disease, with a worldwide incidence of 8 cases per 100,000 population per year. Familial forms constitute approximately 5% to 10% of all cases. Onset increases with age, with a peak in the seventh decade and a slight preponderance (relative risk, 1.3-1.5) among men compared with women. Rapid progression of motor neuron loss leads to death an average of 3 to 5 years after symptom onset. The cause of ALS remains unknown and there is still no curative therapy.

  5. Thermal Conductivity of Al-Salt Composites

    NASA Astrophysics Data System (ADS)

    Li, Peng; Zhang, Mei; Wang, Lijun; Seetharaman, Seshadri

    2015-11-01

    With a view to examine the possibility of estimating the content of entrapped metallic aluminium in the salt cake from aluminium remelting, the thermal diffusivity of reference composites of KCl-NaCl-Al was measured as a function of aluminium metal content at room temperature. The thermal conductivity of the reference composites was found to increase with the metallic Al content. The lumped parameter model approach was carried out to discuss the influence of different geometry arrangements of each phase, viz. air, salts and metallic aluminium on the thermal conductivity. Application of the present results to industrial samples indicates that factors such as the interfacial condition of metallic Al particles have to be considered in order to estimate the amount of entrapped Al in the salt cake.

  6. 12th Annual ALS Users' Association Meeting

    SciTech Connect

    Robinson, Arthur L.

    1999-12-17

    Science took the front seat as 219 Advanced Light Source (ALS) users and staff gathered on Monday and Tuesday, October 18 and 19 for the twelfth annual users' meeting. The bulk of the meeting was dedicated to reports on science at the ALS. Packed into two busy days were 31 invited oral presentations and 80 submitted poster presentations, as well as time to visit 24 vendor booths. The oral sessions were dedicated to environmental science, chemical dynamics, biosciences, magnetic materials, and atomic and molecular science. In addition, there was an ALS highlights session that emphasized new results and a session comprising highlights from the young scientists who will carry the ALS into the future.

  7. Multiloop string vertices from the path integral

    NASA Astrophysics Data System (ADS)

    Bochicchio, M.; Lerda, A.

    1989-02-01

    We derive the multiloop vertices for the bosonic string using path integral methods and establish a precise equivalence between the functional approach to string perturbation theory and the operator formalism on Riemann surfaces recently developed by various authors. One of us (A.L.) would like to thank P. Di Vecchia and S. Sciuto for helpful discussions and INFN, Sezione di Torino, for the kind hospitality extended to him during the completion of this work. The work of M.B. was partially supported by the National Science Foundation under Grant NSF-PHY85-07627. The work of A.L. was partially supported by the US Department of Energy under grant DE-AC02-76ER03069.

  8. Nanosynthesis routes to new tetrahedral crystalline solids: silicon-like Si3AlP.

    PubMed

    Watkins, Tylan; Chizmeshya, Andrew V G; Jiang, Liying; Smith, David J; Beeler, Richard T; Grzybowski, Gordon; Poweleit, Christian D; Menéndez, José; Kouvetakis, John

    2011-10-12

    We introduce a synthetic strategy to access functional semiconductors with general formula A(3)XY (A = IV, X-Y = III-V) representing a new class within the long-sought family of group IV/III-V hybrid compounds. The method is based on molecular precursors that combine purposely designed polar/nonpolar bonding at the nanoscale, potentially allowing precise engineering of structural and optical properties, including lattice dimensions and band structure. In this Article, we demonstrate the feasibility of the proposed strategy by growing a new monocrystalline AlPSi(3) phase on Si substrates via tailored interactions of P(SiH(3))(3) and Al atoms using gas source (GS) MBE. In this case, the high affinity of Al for the P ligands leads to Si(3)AlP bonding arrangements, which then confer their structure and composition to form the corresponding Si(3)AlP target solid via complete elimination of H(2) at ∼500 °C. First principle simulations at the molecular and solid-state level confirm that the Si(3)AlP building blocks can readily interlink with minimal distortion to produce diamond-like structures in which the P atoms are arranged on a common sublattice as third-nearest neighbors in a manner that excludes the formation of unfavorable Al-Al bonds. High-resolution XRD, XTEM, and RBS indicate that all films grown on Si(100) are tetragonally strained and fully coherent with the substrate and possess near-cubic symmetry. The Raman spectra are consistent with a growth mechanism that proceeds via full incorporation of preformed Si(3)AlP tetrahedra with residual orientational disorder. Collectively, the characterization data show that the structuro-chemical compatibility between the epilayer and substrate leads to flawless integration, as expected for pseudohomoepitaxy of an Si-like material grown on a bulk Si platform. PMID:21877711

  9. Electronic Structure of EuAl4 Studied by Photoelectron Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kobata, Masaaki; Fujimori, Shin-ichi; Takeda, Yukiharu; Okane, Tetsuo; Saitoh, Yuji; Kobayashi, Keisuke; Yamagami, Hiroshi; Nakamura, Ai; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika

    2016-09-01

    The electronic structure of the divalent Eu compound EuAl4, which shows a charge density wave transition at TCDW = 140 K, was studied by hard X-ray angle-integrated photoelectron spectroscopy (HAXPES) and soft X-ray angle-resolved photoelectron spectroscopy (ARPES). The valence band and core-level spectra obtained by HAXPES are consistent with the divalent nature of Eu atoms in EuAl4. From the ARPES results, the Fermi surface as well as band structure in the vicinity of the Fermi energy (EF) of EuAl4 are very similar to those of its isostructural divalent Sr compound SrAl4, which has no 4f electrons. This suggests that the Eu atoms are divalent in EuAl4, and the 4f electrons are localized below 1.8 eV with the Eu 4f7 electronic configuration in the ground state. The ARPES spectra measured along the Γ-(Σ)-Z high-symmetry line did not show significant temperature dependences above and below TCDW within the energy resolution of 80-90 meV. Moreover, the Fermi surface mapping along the kz direction showed that both EuAl4 and SrAl4 have mostly three-dimensional electronic structures, suggesting that the nesting of the Fermi surface is not simple. The Fermi surface and the band structure of EuAl4 were well explained by the band-structure calculation of SrAl4 based on the local density approximation.

  10. Oxygen-induced changes in electron-energy-loss spectra for Al, Be and Ni. [Al; Be; Ni

    SciTech Connect

    Madden, H.H.; Landers, R.; Kleiman, G.G. , 13081-970 Campinas, Sao Paulo, Brasil); Zehner, D.M. )

    1999-09-01

    Electron-energy-loss spectroscopy (EELS) data are presented to illustrate line shape changes that occur as a result of oxygen interaction with metal surfaces. The metals were aluminum, beryllium and nickel. Core-level EELS data were taken for excitations from Al(2p), Be(1s), Ni(3p/3s) and O(1s) levels to the conduction band (CB) density of states (DOS) of the materials. The primary beam energies for the spectra were 300, 450, 300, and 1135 eV, respectively. The data are presented in both the (as measured) first-derivative and the integral forms. The integral spectra were corrected for coherent background losses and analyzed for CB DOS information. These spectra were found to be in qualitative agreement with published experimental and theoretical studies of these materials. One peak in the spectra for Al oxide is analyzed for its correlation with excitonic screening of the Al(2p) core hole. Similar evidence for exciton formation is found in the Ni(3p) spectra for Ni oxide. Data are also presented showing oxygen-induced changes in the lower-loss-energy EELS curves that, in the pure metal, are dominated by plasmon-loss and interband-transition signals. Single-scattering loss profiles in the integral form of the data were calculated using a procedure of Tougaard and Chorkendorff [S. Tougaard and I. Chorkendorff, Phys. Rev. B. [bold 35], 6570 (1987)]. For all three oxides these profiles are dominated by a feature with a loss energy of around 20[endash]25 eV. Although this feature has been ascribed by other researchers as due to bulk plasmon losses in the oxide, an alternative explanation is that the feature is simply due to O(2s)-to-CB-level excitations. An even stronger feature is found at 7 eV loss energy for Ni oxide. Speculation is given as to its source. The line shapes in both the core-level and noncore-level spectra can also be used simply as [open quotes]fingerprints[close quotes] of the surface chemistry of the materials. Our data were taken using commercially

  11. 17th Annual ALS Users' Association Meeting

    SciTech Connect

    Robinson, Art; Tamura, Lori

    2004-11-29

    It's not exactly Russian roulette, but scheduling October events outdoors is not risk-free, even in usually sunny California. An overflow crowd of more than 400 registered users, ALS staff, and vendors enjoyed a full indoor program featuring science highlights and workshops spread over two and a half days from October 18 to October 20. However, a major storm, heralding the onset of the San Francisco Bay Area rainy season, posed a few weather challenges for the events on the ALS patio.

  12. Continuous germanene layer on Al(111).

    PubMed

    Derivaz, Mickael; Dentel, Didier; Stephan, Régis; Hanf, Marie-Christine; Mehdaoui, Ahmed; Sonnet, Philippe; Pirri, Carmelo

    2015-04-01

    Germanene, a 2D honeycomb structure similar to silicene, has been fabricated on Al(111). The 2D germanene layer covers uniformly the substrate with a large coherence over the Al(111) surface atomic plane. It is characterized by a (3 × 3) superstructure with respect to the substrate lattice, shown by low energy electron diffraction and scanning tunnelling microscopy. First-principles calculations indicate that the Ge atoms accommodate in a very regular atomic configuration with a buckled conformation. PMID:25802988

  13. Qtaim studies of [Li(DMSO)n]+ and [Al(DMSO)n]3+

    NASA Astrophysics Data System (ADS)

    Breza, Martin

    2015-12-01

    Geometry optimization of [Li(DMSO)n]+ and [Al(DMSO)n]3+ complexes with n = 1 - 6 in DMSO (dimethyl sulfoxide, (CH3)2SO) solutions is performed using DFT treatment with B3LYP hybrid functional and cc-pVDZ basis sets. Solvent effects are approximated within Integral Equation Formalism Polarisable Continuum Model. Electron structure of individual model systems is investigated in terms of Quantum Theory of Atoms-in-Molecule topological analysis of electron density. Metal-DMSO bonding through oxygen atom is preferred. The most probable coordination numbers n = 4 for Li+ and n = 6 for Al3+ complexes with DMSO are concluded.

  14. Discovery of a metastable Al20Sm4 phase

    SciTech Connect

    Ye, Z.; Zhang, F.; Sun, Y.; Mendelev, M. I.; Ott, R. T.; Park, E.; Besser, M. F.; Kramer, M. J.; Ding, Z.; Wang, C. -Z.; Ho, K. -M.

    2015-03-09

    In this study, we present an efficient genetic algorithm, integrated with experimental diffraction data, to solve a nanoscale metastable Al20Sm4 phase that evolves during crystallization of an amorphous magnetron sputtered Al90Sm10 alloy. The excellent match between calculated and experimental X-ray diffraction patterns confirms an accurate description of this metastable phase. Molecular dynamic simulations of crystal growth from the liquid phase predict the formation of disordered defects in the devitrified crystal.

  15. The effects of gravity level during directional solidification on the microstructure of hypermonotectic Al-In-Sn alloys

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Kaukler, W. F.

    1986-01-01

    Five hypermonotectic Al-In-Sn compositions were directionally solidified in a Bridgman-type furnace at normal gravity and during aircraft low-gravity maneuvers. The tendency of the Al-30In alloy to form an indium-rich band at the start of unidirectional growth (SUG) made it difficult to study the integration of L sub 2 into the solidification interface. Hypermonotectic compositions closer to monotectic slightly hypermonotectic caused only a partial band on L sub 2 to form at SUG and allowed the study of such variables as gravity, composition, and monotectic dome height on integration of excess L sub 2 into the solid plus L sub 2 interface. It was found that formation of aligned composite structures for the Al-In-Sn system is not only a function of G and R but also of the degree to which the composition varies from monotectic. Most of the aligned fibrous structures formed from hypermonotectic Al-In-Sn had spacings that were of the order of irregular fibrous structures reported for on monotectic Al-In-Sn. The spacings for the large fibers and aligned globules found for ground and low-gravity processed Al-In-18-Sn-22, respectively, were significantly larger than the others measured and were of the order expected for cell spacings under the growth conditions utilized. It was found that the integration into the solidification front of excess L sub 2 in low gravity was a function of the Sn composition of the alloy.

  16. Chemical ordering of Co and Ni in a W-(AlCoNi) crystalline approximant related to Al-Co-Ni decagonal quasicrystals studied by atomic resolution energy-dispersive X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Yasuhara, Akira; Hiraga, Kenji

    2015-01-01

    A W-(AlCoNi) crystalline approximant, which is closely related to Al-Co-Ni decagonal quasicrystals, in an Al72.5Co20Ni7.5 alloy has been studied by atomic resolution energy-dispersive X-ray spectroscopy (EDS), in an instrument attached to a spherical aberration (Cs)-corrected scanning transmission electron microscope. On high-resolution EDS maps of Co and Ni elements, obtained by integrating many sets of EDS data taken from undamaged areas, chemical ordering of Co and Ni is clearly detected. In the structure of the W-(AlCoNi) phase, consisting of arrangements of transition-metal (TM) atoms located at vertices of pentagonal tilings and pentagonal arrangements of mixed sites (MSs) of TM and Al atoms, Co atoms occupy the TM atom positions with the pentagonal tiling and Ni is enriched in part of the pentagonal arrangements of MSs.

  17. Ab initio local energy and local stress: application to tilt and twist grain boundaries in Cu and Al.

    PubMed

    Wang, Hao; Kohyama, Masanori; Tanaka, Shingo; Shiihara, Yoshinori

    2013-07-31

    The energy-density and stress-density schemes (Shiihara et al 2010 Phys. Rev. B 81 075441) within the projector augmented wave (PAW) method based on the generalized gradient approximation (GGA) have been applied to tilt and twist grain boundaries (GBs) and single vacancies in Cu and Al. Local energy and local stress at GBs and defects are obtained by integrating the energy and stress densities in each local region by the Bader integration using a recent algorithm (Yu et al 2011 J. Chem. Phys. 134 064111) as well as by the layer-by-layer integration so as to settle the gauge-dependent problem in the kinetic terms. Results are compared with those by the fuzzy-Voronoi integration and by the embedded atom method (EAM). The features of local energy and local stress at GBs and vacancies depend on the bonding nature of each material. Valence electrons in Al mainly located in the interatomic regions show remarkable response to structural disorder as significant valence charge redistribution or bond reconstruction, often leading to long-range variations of charges, energies and stresses, quite differently from d electrons in Cu mainly located near nuclei. All these features can be well represented by our local energy and local stress. The EAM potential for Al does not reproduce correct local energy or local stress, while the EAM potential for Cu provides satisfactory results.

  18. Metastability in the MgAl2O4-Al2O3 System

    DOE PAGES

    Wilkerson, Kelley R.; Smith, Jeffrey D.; Hemrick, James G.

    2014-07-22

    Aluminum oxide must take a spinel form ( γ-Al2O3) at elevated temperatures in order for extensive solid solution to form between MgAl2O4 and α-Al2O3. The solvus line between MgAl2O4 and Al2O3 has been defined at 79.6 wt% Al2O3 at 1500°C, 83.0 wt% Al2O3 at 1600°C, and 86.5 wt% Al2O3 at 1700°C. A metastable region has been defined at temperatures up to 1700°C which could have significant implications for material processing and properties. Additionally, initial processing could have major implications on final chemistry. The spinel solid solution region has been extended to form an infinite solid solution with Al2O3 at elevatedmore » temperatures. A minimum in melting at 1975°C and a chemistry of 96 wt% Al2O3 rather than a eutectic is present, resulting in no eutectic crystal formation during solidification.« less

  19. Next-generation sequencing of 28 ALS-related genes in a Japanese ALS cohort.

    PubMed

    Nakamura, Ryoichi; Sone, Jun; Atsuta, Naoki; Tohnai, Genki; Watanabe, Hazuki; Yokoi, Daichi; Nakatochi, Masahiro; Watanabe, Hirohisa; Ito, Mizuki; Senda, Jo; Katsuno, Masahisa; Tanaka, Fumiaki; Li, Yuanzhe; Izumi, Yuishin; Morita, Mitsuya; Taniguchi, Akira; Kano, Osamu; Oda, Masaya; Kuwabara, Satoshi; Abe, Koji; Aiba, Ikuko; Okamoto, Koichi; Mizoguchi, Kouichi; Hasegawa, Kazuko; Aoki, Masashi; Hattori, Nobutaka; Tsuji, Shoji; Nakashima, Kenji; Kaji, Ryuji; Sobue, Gen

    2016-03-01

    We investigated the frequency and contribution of variants of the 28 known amyotrophic lateral sclerosis (ALS)-related genes in Japanese ALS patients. We designed a multiplex, polymerase chain reaction-based primer panel to amplify the coding regions of the 28 ALS-related genes and sequenced DNA samples from 257 Japanese ALS patients using an Ion Torrent PGM sequencer. We also performed exome sequencing and identified variants of the 28 genes in an additional 251 ALS patients using an Illumina HiSeq 2000 platform. We identified the known ALS pathogenic variants and predicted the functional properties of novel nonsynonymous variants in silico. These variants were confirmed by Sanger sequencing. Known pathogenic variants were identified in 19 (48.7%) of the 39 familial ALS patients and 14 (3.0%) of the 469 sporadic ALS patients. Thirty-two sporadic ALS patients (6.8%) harbored 1 or 2 novel nonsynonymous variants of ALS-related genes that might be deleterious. This study reports the first extensive genetic screening of Japanese ALS patients. These findings are useful for developing genetic screening and counseling strategies for such patients.

  20. Magnetism in Fe4Al13 and related FeAl intermetallics

    NASA Astrophysics Data System (ADS)

    Chi, Ji; Li, Yang; Gou, Weiping; Goruganti, V.; Rathnayaka, K. D. D.; Ross, Joseph H., Jr.

    2006-03-01

    We report the results of an experimental study of FeAl alloys, including Fe4Al13, FeAl2 and Fe2Al5. By using NMR, dc magnetic susceptibility, and specific heat, we found that Fe4Al13 and Fe2Al5 are non-magnetic with some dilute magnetic moments, while FeAl2 can be characterized as a concentrated local moment system. Fe4Al13 is a decagonal quasicrystal approximant with 102 atoms in its unit cell. The ^27Al NMR spin-lattice relaxation indicates a very narrow pseudogap in the electronic density of states [g(E)] in the vicinity of the Fermi energy. The observations could be fit assuming a parabolic variation of g(E), consistent with observations in other quasicrystals and approximants. NMR lineshape measurements also agree with this analysis, and show that the system is dilute-magnetic, in strong contrast to the FeAl2 ordered intermetallic. We use specific heat to analyze the dilute moment density. This work was supported by the Robert A. Welch Foundation, Grant No. A-1526, by the National Science Foundation (DMR-0103455), and by Texas A&M University through the Telecommunications and Informatics Task Force.

  1. Thermodynamics and surface properties of liquid Al-Ga and Al-Ge alloys

    NASA Astrophysics Data System (ADS)

    Anusionwu, B. C.; Adebayo, G. A.; Madu, C. A.

    2009-11-01

    The surface properties of Al-Ga and Al-Ge liquid alloys have been theoretically investigated at a temperature of 1100 K and 1220 K respectively. For the Al-Ga system, the quasi chemical model for regular alloy and a model for phase segregating alloy systems were applied, while for the Al-Ge system the quasi chemical model for regular and compound forming binary alloys were applied. In the case of Al-Ga, the models for the regular alloys and that for the phase segregating alloys produced the same value of order energy and same values of thermodynamic and surface properties, while for the Al-Ge system, the model for the regular alloy reproduced better the thermodynamic properties of the alloy. The model for the compound forming systems showed a qualitative trend with the measured values of the thermodynamic properties of the Al-Ge alloy and suggests the presence of a weak complex of the form Al2Ge3. The surface concentrations for the alloys show that Ga manifests some level of surface segregation in Al-Ga liquid alloy while the surface concentration of Ge in Al-Ge liquid alloy showed a near Roultian behavior below 0.8 atomic fraction of Ge.

  2. Clinical trials for neuroprotection in ALS.

    PubMed

    Siciliano, G; Carlesi, C; Pasquali, L; Piazza, S; Pietracupa, S; Fornai, F; Ruggieri, S; Murri, L

    2010-07-01

    Owing to uncertainty on the pathogenic mechanisms underlying motor neuron degeneration in amyotrophic lateral sclerosis (ALS) riluzole remains the only available therapy, with only marginal effects on disease survival. Here we review some of the recent advances in the search for disease-modifying drugs for ALS based on their putative neuroprotective effetcs. A number of more or less established agents have recently been investigated also in ALS for their potential role in neuroprotection and relying on antiglutamatergic, antioxidant or antiapoptotic strategies. Among them Talampanel, beta-lactam antibiotics, Coenzyme Q10, and minocycline have been investigated. Progress has also been made in exploiting growth factors for the treatment of ALS, partly due to advances in developing effective delivery systems to the central nervous system. A number of new therapies have also been identified, including a novel class of compounds, such as heat-shock protein co-inducers, which upregulate cell stress responses, and agents promoting autophagy and mitochondriogenesis, such as lithium and rapamycin. More recently, alterations of mRNA processing were described as a pathogenic mechanism in genetically defined forms of ALS, as those related to TDP-43 and FUS-TLS gene mutations. This knowledge is expected to improve our understanding of the pathogenetic mechanism in ALS and developing more effective therapies. PMID:20406180

  3. Modeling of precipitation in Al alloys

    SciTech Connect

    Asta, M.; Foiles, S.M.; Wolfer, W.G.

    1996-10-01

    Objective was the development of a computational model of precipitation from a supersaturated alloy solid solution. The model is based on the formalism of chemical-reaction-rate theory combined with classical descriptions of precipitate thermodynamic properties and a mean-field treatment of diffusion-limited growht and coarsening. For the case of precipitation of Al{sub 3}Sc in supersaturated Al-Sc alloys, it is demonstrated how the model can be used to calculate number densities and size distributions of precipitates as a function of aging time and temperature, including effects of continuous cooling and thermally generated point defects. Application of the model to a specific alloy system requires knowledge of diffusion data, point defect energetics, and thermodynamic properties for bulk phases and interphase interfaces. For interfaces and point defects, thermodynamic data can be difficult to measure and reliable values of defect free energies are often unavailable. For this reason, part of the efforts were devoted to applying semiempirical and first-principles atomistic techniques to the calculation of interfacial and point-defect thermodynamic properties. This report discusses applications for interphase interfaces in the Al-Ag, Al-Sc, and Al-Li alloy systems. We also describe atomistic work aimed at understanding the energetics of vacancy clusters in Al. These clusters serve as sinks for isolated vacancies during aging and their growth can lead to more complex defects, such as dislocation loops, that act as heterogeneous nucleation sites.

  4. Comparative Study on Intersubband Absorption in AlGaN/GaN and AlInN/GaN Heterostructures Grown on Low-Defect Substrates

    NASA Astrophysics Data System (ADS)

    Edmunds, Colin; Tang, Liang; Shao, Jiayi; Li, Donghui; Gardner, Geoff; Manfra, Michael; Malis, Oana; Grier, Andrew; Ikonic, Zoran; Harrison, Paul; Zakharov, Dimitri

    2013-03-01

    Intersubband (ISB) devices utilizing III-nitrides have attracted attention for near- and far-infrared optoelectronic applications. However, the lattice mismatch between GaN and commonly used substrates results in a high defect density that hinders the vertical transport required for these devices. Furthermore, most devices in the literature utilize AlGaN/GaN heterostructures for which there is no lattice-matched alloy composition. Due to this lattice mismatch, AlGaN is not ideal for the development of complex devices such as quantum cascade lasers that often require active-region thicknesses on the order of microns for efficient operation. Fortunately, exact lattice matching occurs in AlInN/GaN heterostructures at roughly 18% In composition. To investigate the challenges of lattice-matched nitrides, we presents a comparative study of ISB absorption in high-quality AlGaN/GaN and near lattice-matched AlInN/GaN heterostructures grown by molecular-beam epitaxy on low-defect free-standing GaN substrates. Experimental measurements of transition energy, integrated absorbance and linewidth were compared to theoretical predictions that included many-body effects, interface roughness and calculations of the transition lifetime.

  5. Integration of unmanned systems for tactical operations within hostile environments

    NASA Astrophysics Data System (ADS)

    Maddux, Gary A.; Bosco, Charles D.; Lawrence, James D.

    2006-05-01

    The University of Alabama in Huntsville (UAH) is currently investigating techniques and technologies for the integration of a small unmanned aerial vehicle (SUAV) with small unmanned ground vehicles (SUGV). Each vehicle has its own set of unique capabilities, but the efficient integration of the two for a specific application requires modifying and integrating both systems. UAH has been flying and testing an autonomously-controlled small helicopter, called the Flying Bassett (Base Airborne Surveillance and Sensing for Emergency Threat Tracking) for over a year. Recently, integrated operations were performed with four SUGVs, the Matilda (Mesa Robotics, Huntsville, AL), the US Navy Vanguard, the UAH Rover, and the Penetrator (Mesa Robotics). The program has progressed from 1) building an air and ground capability for video and infrared surveillance, 2) integration with ground vehicles in realistic scenarios, to 3) deployment and recovery of ground vehicles. The work was done with the cooperation of the US Army at Ft. Benning, GA and Redstone Arsenal, AL, the Federal Bureau of Investigation in Huntsville, AL, the US Naval Reserve in Knoxville, TN, and local emergency organizations. The results so far have shown that when the air and ground systems are employed together, their utility is greatly enhanced.

  6. Klystron 'efficiency loop' for the ALS storage ring RF system

    SciTech Connect

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-05-20

    The recent energy crisis in California has led us to investigate the high power RF systems at the Advanced Light Source (ALS) in order to decrease the energy consumption and power costs. We found the Storage Ring Klystron Power Amplifier system operating as designed but with significant power waste. A simple proportional-integrator (PI) analog loop, which controls the klystron collector beam current, as a function of the output RF power, has been designed and installed. The design considerations, besides efficiency improvement, were to interface to the existing system without major expense. They were to also avoid the klystron cathode power supply filter's resonance in the loop's dynamics, and prevent a conflict with the existing Cavity RF Amplitude Loop dynamics. This efficiency loop will allow us to save up to 700 MW-hours of electrical energy per year and increase the lifetime of the klystron.

  7. Evolving science in adolescence: comment on Ellis et al. (2012).

    PubMed

    Dodge, Kenneth A; Albert, Dustin

    2012-05-01

    Ellis et al. (2012) bring an evolutionary perspective to bear on adolescent risky behavioral development, clinical practice, and public policy. The authors offer important insights that (a) some risky behaviors may be adaptive for the individual and the species by being hard-wired due to fitness benefits and (b) interventions might be more successful if they move with, rather than against, the natural tendencies of an adolescent. Ellis and colleagues criticize the field of developmental psychopathology, but we see the 2 fields as complementary. Their position would be enhanced by integrating it with contemporary perspectives on dynamic cascades through which normative behavior turns into genuinely maladaptive outcomes, dual processes in adolescent neural development, and adolescent decision making. Finally, they rightly note that innovation is needed in interventions and policies toward adolescent problem behavior.

  8. Final analysis of the ALS lattice magnet data

    SciTech Connect

    Keller, R.

    1993-05-01

    A preliminary analysis of the measured magnet data of the multipole magnets to be installed in the Advanced Light Source (ALS) storage ring had been given in the last conference of this series. That analysis was based on measurements of about one-third of the entire magnet complement, and some of its findings had to be revised after obtaining more data. The present paper gives an account of the integrated fundamental field strengths of all installed storage ring lattice magnets. For the multipole magnets, these values are listed as analytical expressions with four or five parameters, that cover the entire excitation range and include residual strength. Based on this final analysis, all gradient and quadrupole magnets were qualified for installation, whereas the sextupole magnets had to be individually trimmed to bring their effective fundamental strengths into the desired tolerance band.

  9. Distinct Changes in Synaptic Protein Composition at Neuromuscular Junctions of Extraocular Muscles versus Limb Muscles of ALS Donors

    PubMed Central

    Liu, Jing-Xia; Brännström, Thomas; Andersen, Peter M.; Pedrosa-Domellöf, Fatima

    2013-01-01

    The pathophysiology of amyotrophic lateral sclerosis (ALS) is very complex and still rather elusive but in recent years evidence of early involvement of the neuromuscular junctions (NMJs) has accumulated. We have recently reported that the human extraocular muscles (EOMs) are far less affected than limb muscles at the end-stage of ALS from the same donor. The present study aimed to compare the differences in synaptic protein composition at NMJ and in nerve fibers between EOM and limb muscles from ALS donors and controls. Neurofilament light subunit and synaptophysin decreased significantly at NMJs and in nerve fibers in limb muscles with ALS whereas they were maintained in ALS EOMs. S100B was significantly decreased at NMJs and in nerve fibers in both EOMs and limb muscles of ALS donors, but other markers confirmed the presence of terminal Schwann cells in these NMJs. p75 neurotrophin receptor was present in nerve fibers but absent at NMJs in ALS limb muscles. The EOMs were able to maintain the integrity of their NMJs to a very large extent until the end-stage of ALS, in contrast to the limb muscles. Changes in Ca2+ homeostasis, reflected by altered S100B distribution, might be involved in the breakdown of nerve-muscle contact at NMJs in ALS. PMID:23468993

  10. Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

    NASA Astrophysics Data System (ADS)

    Besleaga, C.; Stan, G. E.; Pintilie, I.; Barquinha, P.; Fortunato, E.; Martins, R.

    2016-08-01

    The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium-gallium-zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium-gallium-zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

  11. Integrated Marketing Communications

    ERIC Educational Resources Information Center

    Black, Jim

    2004-01-01

    Integration has become a cliche in enrollment management and student services circles. The term is used to describe everything from integrated marketing to seamless services. Often, it defines organizational structures, processes, student information systems, and even communities. In Robert Sevier's article in this issue of "College and…

  12. Elementary Integrated Curriculum Framework

    ERIC Educational Resources Information Center

    Montgomery County Public Schools, 2010

    2010-01-01

    The Elementary Integrated Curriculum (EIC) Framework is the guiding curriculum document for the Elementary Integrated Curriculum and represents the elementary portion of the Montgomery County (Maryland) Public Schools (MCPS) Pre-K-12 Curriculum Frameworks. The EIC Framework contains the detailed indicators and objectives that describe what…

  13. System integration report

    NASA Technical Reports Server (NTRS)

    Badler, N. I.; Korein, J. D.; Meyer, C.; Manoochehri, K.; Rovins, J.; Beale, J.; Barr, B.

    1985-01-01

    Several areas that arise from the system integration issue were examined. Intersystem analysis is discussed as it relates to software development, shared data bases and interfaces between TEMPUS and PLAID, shaded graphics rendering systems, object design (BUILD), the TEMPUS animation system, anthropometric lab integration, ongoing TEMPUS support and maintenance, and the impact of UNIX and local workstations on the OSDS environment.

  14. Integration in Hydraulics.

    ERIC Educational Resources Information Center

    Sworder, Steven C.

    This paper presents an application of integration to the field of hydraulics. An integral relation for the time required to drop the fluid contained in a cylindrical tank from one level to another using a hole in the tank wall is derived. Procedures for constructing the experimental equipment and procedures for determining the coefficient of…

  15. Academic Research Integration System

    ERIC Educational Resources Information Center

    Surugiu, Iula; Velicano, Manole

    2008-01-01

    This paper comprises results concluding the research activity done so far regarding enhanced web services and system integration. The objective of the paper is to define the software architecture for a coherent framework and methodology for enhancing existing web services into an integrated system. This document presents the research work that has…

  16. Integrated Assessments for ELL

    ERIC Educational Resources Information Center

    Armon, Joan; Morris, Linda J.

    2008-01-01

    Despite the challenges posed by increased time, specialized vocabularies, and balance, integrating writing and drawing with science investigations is beneficial for teachers and students. This month's column explains why this integrated approach is beneficial, and illustrates how teachers can use it to meet the needs of students learning English…

  17. An Integrated Teaching Module.

    ERIC Educational Resources Information Center

    Samuel, Marie R.; Seiferth, Berniece B.

    This integrated teaching module provides elementary and junior high school teachers with a "hands-on" approach to studying the Anasazi Indian. Emphasis is on creative exploration that focuses on integrating art, music, poetry, writing, geography, dance, history, anthropology, sociology, and archaeology. Replicas of artifacts, contemporary Indian…

  18. The Fresnel Integrals Revisited

    ERIC Educational Resources Information Center

    Chen, Hongwei

    2009-01-01

    This note presents another elementary method to evaluate the Fresnel integrals. It is interesting to see that this technique is also strong enough to capture a number of pairs of parameter integrals. The main ingredients of the method are the consideration of some related derivatives and linear differential equations.

  19. Undulator Field Integral Measurements

    SciTech Connect

    Wolf, Zachary

    2010-12-07

    The LCLS undulator field integrals must be very small so that the beam trajectory slope and offset stay within tolerance. In order to make accurate measurements of the small field integrals, a long coil will be used. This note describes the design of the coil measurement system.

  20. Integrity in Student Development

    ERIC Educational Resources Information Center

    Roberts, Dennis C.; Banta, Trudy W.

    2011-01-01

    The quest for integrity in practice and theory has been part of the evolution of student personnel work all the way back to the turn of the 20th century. This chapter seeks to take stock of the question of integrity in relation to one of the core knowledge bases used by those engaged in student affairs work today--student development. The authors…

  1. Hermeneutics of Integrative Knowledge.

    ERIC Educational Resources Information Center

    Shin, Un-chol

    This paper examines and compares the formation processes and structures of three types of integrative knowledge that in general represent natural sciences, social sciences, and humanities. These three types can be observed, respectively, in the philosophies of Michael Polanyi, Jurgen Habermas, and Paul Ricoeur. These types of integrative knowledge…

  2. Integration by Hyperbolic Substitution

    ERIC Educational Resources Information Center

    Price, David

    2012-01-01

    Mathematics teachers constantly encourage their students to think independently. The study of integration in calculus provides an excellent opportunity to encourage inventive investigation. In contrast to differentiation, which is predominately mechanical, integration is a more creative process. One such possibility is offered by the study of the…

  3. Integrity in Transactional Leadership

    ERIC Educational Resources Information Center

    Miller, Thomas

    2011-01-01

    This chapter begins with a discussion of the impact of limited resources on the integrity of transactions between students and student affairs administrators. A framework and guiding principles for maintaining integrity are offered, and then some general principles for transactions with students are presented. Next, the chapter involves integrity…

  4. Integrating Module - NEMS Documentation

    EIA Publications

    2014-01-01

    Provides an overview of the complete National Energy Modeling System (NEMS) model, and includes brief descriptions of the modules with which the Integrating Module interacts. The emphasis and focus, however, is on the structure and function of the Integrating Module of NEMS.

  5. Ready, Set, Integrate!

    ERIC Educational Resources Information Center

    McCombs, John

    2003-01-01

    Describes how the American Embassy School (AES) in New Delhi, India achieved school-wide technology integration. Discusses development of a new network; beginning to mentor; organizing the Technology Integration Plan (TIP) by software application; implementing the plan; assessing progress; and results, which overall, were positive. (AEF)

  6. Systems Integration (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    The Systems Integration (SI) subprogram works closely with industry, universities, and the national laboratories to overcome technical barriers to the large-scale deployment of solar technologies. To support these goals, the subprogram invests primarily in four areas: grid integration, technology validation, solar resource assessment, and balance of system development.

  7. Systems Integration (Fact Sheet)

    SciTech Connect

    DOE Solar Energy Technologies Program

    2011-10-13

    The Systems Integration (SI) subprogram works closely with industry, universities, and the national laboratories to overcome technical barriers to the large-scale deployment of solar technologies. To support these goals, the subprogram invests primarily in four areas: grid integration, technology validation, solar resource assessment, and balance of system development.

  8. What Is Integral Theory?

    ERIC Educational Resources Information Center

    Marquis, Andre

    2007-01-01

    Integral theory is a way of knowing that helps foster the recognition that disparate aspects of reality--such as biological constitution, cultural worldviews, felt-sense of selfhood, and social systems--are all critically important to any knowledge quest. Integral theory provides an "all quadrants, all levels" (K. Wilber, 2006, p. 26)…

  9. Designing for STEM Integration

    ERIC Educational Resources Information Center

    Berland, Leema K.

    2013-01-01

    We are increasingly seeing an emphasis on STEM integration in high school classrooms such that students will learn and apply relevant math and science content while simultaneously developing engineering habits of mind. However, research in both science education and engineering education suggests that this goal of truly integrating STEM is rife…

  10. Kinetic Monte Carlo of transport processes in Al/AlOx/Au-layers: Impact of defects

    NASA Astrophysics Data System (ADS)

    Weiler, Benedikt; Haeberle, Tobias; Gagliardi, Alessio; Lugli, Paolo

    2016-09-01

    Ultrathin films of alumina were investigated by a compact kMC-model. Experimental jV-curves from Al/AlOx/Au-junctions with plasma- and thermal-grown AlOx were fitted by simulated ones. We found dominant defects at 2.3-2.5 eV below CBM for AlOx with an effective mass mox ∗= 0.35 m0 and a barrier EB ,A l /A l O x≈2.8 eV in agreement with literature. The parameterization is extended to varying defect levels, defect densities, injection barriers, effective masses and the thickness of AlOx. Thus, dominant charge transport processes and implications on the relevance of defects are derived and AlOx parameters are specified which are detrimental for the operation of devices.

  11. Theoretical studies of Ni/sub 3/Al and NiAl with impurities

    SciTech Connect

    Chen, S.P.; Voter, A.F.; Boring, A.M.; Albers, R.C.; Hay, P.J.

    1988-01-01

    Intermetallic compound has been extensively studied because of their superior properties in strength, low creep rate, and high melting point. But most of the systems have room temperature ductility problems, like Ll/sub 2/ and B2 compounds. Both Ll/sub 2/ Ni/sub 3/Al and B2 NiAl exhibit intergranular fracture mode. Understanding grain boundaries in these materials is of particular importance since intergranular fracture limits the applicability of these otherwise promising material. In an effort trying to understand the fracture mechanism, we have used embedded atom potentials to study the properties of Ni/sub 3/Al and NiAl. We also consider the effect of boron, sulfur, and nickel segregation on the strength of grain boundaries in Ni/sub 3/Al and NiAl. 22 refs., 2 figs.

  12. Scattering induced by Al segregation in AlGaN/GaN heterostructures

    SciTech Connect

    Liu, Xiwen; Lu, Yanwu; Ji, Dong

    2015-08-17

    The effect of Al segregation near dislocations on the mobility of two-dimensional electron gas in AlGaN/GaN heterostructure-based high-electron-mobility transistors was investigated. Exponentially varied composition fluctuation was effective in describing Al segregation near dislocations when calculating scattering behavior. Mobility, which was limited by Al segregation surrounding dislocation lines, was calculated to be in the order of 10{sup 3} cm{sup 2}/Vs to 10{sup 6} cm{sup 2}/Vs. Results indicated that the mobility in AlGaN/GaN heterojunction was enhanced upon the reduction of dislocation density at low temperature. This study contributes to generating higher electron mobility in AlGaN/GaN heterojunctions.

  13. Microscopic Properties of Long-Period Ordering in Al-Rich TiAl Alloys

    NASA Astrophysics Data System (ADS)

    Hata, S.; Nakano, T.; Kuwano, N.; Itakura, M.; Matsumura, S.; Umakoshi, Y.

    2008-07-01

    The ordering mechanism of long-period superstructures (LPSs) in Al-rich TiAl alloys has been investigated by high-resolution transmission electron microscopy (HRTEM). The LPSs are classified in terms of arrangements of base clusters with different shapes and compositions formed in Ti-rich (002) layers of L10-TiAl matrix: square Ti4Al, fat rhombus Ti3Al, and lean rhombus Ti2Al type clusters. The HRTEM observations revealed that antiphase boundaries of long-range-ordered LPS domains and short-range-ordered microdomains are constructed by various space-filling arrangements of the base clusters. Such a microscopic property characterized by the base clusters and their arrangements is markedly analogous to that of the {left< {{text{1,1/2,0}}} rightrangle } * special-point ordering alloys such as Ni-Mo.

  14. Adaptive Urban Dispersion Integrated Model

    SciTech Connect

    Wissink, A; Chand, K; Kosovic, B; Chan, S; Berger, M; Chow, F K

    2005-11-03

    Numerical simulations represent a unique predictive tool for understanding the three-dimensional flow fields and associated concentration distributions from contaminant releases in complex urban settings (Britter and Hanna 2003). Utilization of the most accurate urban models, based on fully three-dimensional computational fluid dynamics (CFD) that solve the Navier-Stokes equations with incorporated turbulence models, presents many challenges. We address two in this work; first, a fast but accurate way to incorporate the complex urban terrain, buildings, and other structures to enforce proper boundary conditions in the flow solution; second, ways to achieve a level of computational efficiency that allows the models to be run in an automated fashion such that they may be used for emergency response and event reconstruction applications. We have developed a new integrated urban dispersion modeling capability based on FEM3MP (Gresho and Chan 1998, Chan and Stevens 2000), a CFD model from Lawrence Livermore National Lab. The integrated capability incorporates fast embedded boundary mesh generation for geometrically complex problems and full three-dimensional Cartesian adaptive mesh refinement (AMR). Parallel AMR and embedded boundary gridding support are provided through the SAMRAI library (Wissink et al. 2001, Hornung and Kohn 2002). Embedded boundary mesh generation has been demonstrated to be an automatic, fast, and efficient approach for problem setup. It has been used for a variety of geometrically complex applications, including urban applications (Pullen et al. 2005). The key technology we introduce in this work is the application of AMR, which allows the application of high-resolution modeling to certain important features, such as individual buildings and high-resolution terrain (including important vegetative and land-use features). It also allows the urban scale model to be readily interfaced with coarser resolution meso or regional scale models. This talk

  15. SIBYLS - A SAXS and protein crystallography beamline at the ALS

    SciTech Connect

    Trame, Christine; MacDowell, Alastair A.; Celestre, Richard S.; Padmore, Howard A.; Cambie, Daniella; Domning, Edward E.; Duarte, Robert M.; Kelez, Nicholas; Plate, David W.; Holton, James M.; Frankel, Kenneth; Tsutakawa, Susan; Tsuruta, Hiro; Tainer, John A.; Cooper, Priscilla K.

    2003-08-22

    The new Structurally Integrated BiologY for Life Sciences (SIBYLS) beamline at the Advanced Light Source will be dedicated to Macromolecular Crystallography (PX) and Small Angle X-ray Scattering (SAXS). SAXS will provide structural information of macromolecules in solutions and will complement high resolution PX studies on the same systems but in a crystalline state. The x-ray source is one of the 5 Tesla superbend dipoles recently installed at the ALS that allows for a hard x-ray program to be developed on the relatively low energy Advanced Light Source (ALS) ring (1.9 GeV). The beamline is equipped with fast interchangeable monochromator elements, consisting of either a pair of single Si(111) crystals for crystallography, or a pair of multilayers for the SAXS mode data collection (E/{Delta}E {approx} 1/110). Flux rates with Si(111) crystals for PX are measured as 2 x 10{sup 11} hv/sec/400 mA through a 100 {micro}m pinhole at 12.4 KeV. For SAXS the flux is up to 3 x 10{sup 13} photons/sec at 10 KeV with all apertures open when using the multilayer monochromator elements. The performance characteristics of this unique beamline will be described.

  16. Carbon and oxygen isotope variations of the Middle-Late Triassic Al Aziziyah Formation, northwest Libya

    NASA Astrophysics Data System (ADS)

    Moustafa, Mohamed S. H.; Pope, Michael C.; Grossman, Ethan L.; Mriheel, Ibrahim Y.

    2016-06-01

    This study presents the δ13C and δ18O records from whole rock samples of the Middle-Late Triassic (Ladinian-Carnian) Al Aziziyah Formation that were deposited on a gently sloping carbonate ramp within the Jifarah Basin of Northwest Libya. The Al Aziziyah Formation consists of gray limestone, dolomite, and dolomitic limestone interbedded with shale. The Ghryan Dome and Kaf Bates sections were sampled and analyzed for carbon and oxygen isotope chemostratigraphy to integrate high-resolution carbon isotope data with an outcrop-based stratigraphy, to provide better age control of the Al Aziziyah Formation. This study also discusses the relation between the facies architecture of the Al Aziziyah Formation and the carbon isotope values. Seven stages of relative sea level rise and fall within the Ghryan Dome were identified based on facies stacking patterns, field observations and carbon stable isotopes. The Al Aziziyah Formation δ13C chemostratigraphic curve can be partially correlated with the Triassic global δ13C curve. This correlation indicates that the Al Aziziyah Formation was deposited during the Ladinian and early Carnian. No straight-forward relationship is seen between δ13C and relative sea level probably because local influences complicated systematic environmental and diagenetic isotopic effects associated with sea level change.

  17. Retroviral integration: Site matters

    PubMed Central

    Demeulemeester, Jonas; De Rijck, Jan

    2015-01-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co‐opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine‐grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. PMID:26293289

  18. Algebraic integrability: a survey.

    PubMed

    Vanhaecke, Pol

    2008-03-28

    We give a concise introduction to the notion of algebraic integrability. Our exposition is based on examples and phenomena, rather than on detailed proofs of abstract theorems. We mainly focus on algebraic integrability in the sense of Adler-van Moerbeke, where the fibres of the momentum map are affine parts of Abelian varieties; as it turns out, most examples from classical mechanics are of this form. Two criteria are given for such systems (Kowalevski-Painlevé and Lyapunov) and each is illustrated in one example. We show in the case of a relatively simple example how one proves algebraic integrability, starting from the differential equations for the integrable vector field. For Hamiltonian systems that are algebraically integrable in the generalized sense, two examples are given, which illustrate the non-compact analogues of Abelian varieties which typically appear in such systems. PMID:17588863

  19. Remarks on Peinado et al.'s Analysis of J3Gen

    PubMed Central

    Garcia-Alfaro, Joaquin; Herrera-Joancomartí, Jordi; Melià-Seguí, Joan

    2015-01-01

    Peinado et al. analyzed the security of the J3Gen pseudorandom number generator proposed by Melià-Seguí et al., and claimed weaknesses regarding its security properties. They also presented a deterministic attack based on the decimation of the J3Gen output sequences. We show that the assumptions made by Peinado et al. are not correct and that the proposed deterministic attack against J3Gen does not hold in practice. PMID:25781510

  20. Two-Phase (TiAl+TiCrAl) Coating Alloys for Titanium Aluminides

    NASA Technical Reports Server (NTRS)

    Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)

    1998-01-01

    A coating for protecting titanium aluminide alloys, including the TiAl gamma + Ti3Al (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)Al(49-53)Cr(9.5-12.5)

  1. Temperature dependence diode parameters studies of Al/CuPc/n-Si/Al structure

    NASA Astrophysics Data System (ADS)

    Kumar, Ratnesh; Kaur, Ramneek; Sharma, Mamta; Kaur, Maninder; Tripathi, S. K.

    2015-08-01

    This paper presents the fabrication of Al/CuPc/n-Si/Al metal-organic-semiconductor diode. The copper phthalocyanine as organic layer is deposited on Si substrate by thermal evaporation technique. The temperature dependent current-voltage measurements are performed on Al/CuPc/n-Si structure. The important diode parameters i.e. the barrier height and ideality factor have been calculated. The temperature dependence of barrier height and ideality factor has been studied.

  2. CRISPR Outsourcing: Commissioning IHF for Site-Specific Integration of Foreign DNA at the CRISPR Array.

    PubMed

    Wei, Yunzhou; Terns, Michael P

    2016-06-16

    In this issue of Molecular Cell, Nuñez et al. (2016) report that site-specific integration of foreign DNA into CRISPR loci by the Cas1-Cas2 integrase complex is promoted by a host factor, IHF (integration host factor), that binds and bends CRISPR leader DNA. PMID:27315553

  3. The lowest ionization potentials of Al2

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Barnes, Leslie A.; Taylor, Peter R.

    1988-01-01

    Potential curves for the lowest two electronic states (X 2 sigma g + and A 2 pi u) of Al2(+) were computed using complete active space SCF/multireference CI wave functions and large Gaussian basis sets. The lowest observable vertical ionization potential (to Al2(+) X 2 sigma g +) of the Al2 X 3 pi u ground state is calculated to occur around 6.1 eV, in excellent agreement with the experimental range of 6.0 to 6.42 eV obtained in recent cluster ionization studies by Cox and co-workers. The second vertical ionization potential (to Al2(+) A 2 pi u) occurs near 6.4 eV, also within the experimental range. The adiabatic IP of 5.90 eV is in good agreement with the value of 5.8 to 6.1 eV deduced by Hanley and co-workers from the difference in thresholds between collision induced dissociation processes of Al3(+). The computed IP values are somewhat larger than those deduced from branching ratios in cluster fragmentation experiments by Jarrold and co-workers. The observation of an ionization threshold below 6.42 eV is shown to be incompatible with an Al2 ground electronic state assignment of 3 sigma g -, but the separation between the two lowest states of Al2 is so small that it is likely that both are populated in the experiments, so that this does not provide unambiguous support for the recent theoretical assignment of the ground state as 3 pi u.

  4. Chemical trend of superconducting transition temperature in hole-doped delafossite of CuAlO2, AgAlO2 and AuAlO2

    NASA Astrophysics Data System (ADS)

    Nakanishi, Akitaka; Katayama-Yoshida, Hiroshi

    2012-12-01

    We have performed the first-principles calculations about the superconducting transition temperature Tc of hole-doped delafossite CuAlO2, AgAlO2 and AuAlO2. Calculated Tc are about 50 K (CuAlO2), 40 K (AgAlO2) and 3 K(AuAlO2) at maximum in the optimum hole-doping concentration. The low Tc of AuAlO2 is attributed to the weak electron-phonon interaction caused by the low covalency and heavy atomic mass.

  5. High temperature deformation of NiAl and CoAl

    NASA Technical Reports Server (NTRS)

    Nix, W. D.

    1982-01-01

    The high temperature mechanical properties of the aluminides are reviewed with respect to their potential as high temperature structural materials. It is shown that NiAl and CoAl are substantially stronger than the pure metals Ni and Co at high temperatures and approach the strength of some superalloys, particularly when those superalloys are tested in "weak" directions. The factors that limit and control the high temperature strengths of NiAl and CoAl are examined to provide a basis for the development of intermetallic alloys of this type.

  6. Small Al clusters. II - Structure and binding in Al(n) (n = 2-6, 13)

    NASA Technical Reports Server (NTRS)

    Pettersson, Lars G. M.; Bauschlicher, Charles W., Jr.; Halicioglu, Timur

    1987-01-01

    The structure and stability of aluminum clusters containing up to six atoms have been studied using correlated wave functions and extended basis sets. The lowest energy structure is planar for Al4 and Al5, but three dimensional for Al6. The icosahedral, hcp, fcc, and two planar structures of Al13 were considered at the SCF level. The lowest energy structure is the icosahedron, but the planar structures are fairly low lying even in this case. A simplified description using two- and three-body interaction potentials is found to agree well with the ab initio structures and binding energies.

  7. Synthesis of core–shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

    2016-05-01

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

  8. Elastic and piezoelectric properties of AlN and LiAlO2 single crystals.

    PubMed

    Sotnikov, Andrey; Schmidt, Hagen; Weihnacht, Manfred; Smirnova, Elena; Chemekova, Tatiana; Makarov, Yuri

    2010-04-01

    We have successfully grown high-quality AlN piezoelectric single crystal using the sublimation technique. Transparent crack-free boules of approximately 15 mm in diameter and 25 mm in length along the [0001] direction were obtained, with coloring from amber to dark brown depending on growth temperature. Full sets of material parameters of grown AlN and commercially available LiAlO(2) bulk crystals were measured at room temperature. Temperature coefficients of the material parameters of LiAlO(2) were also obtained in a temperature range from -70 to +50 degrees C.

  9. Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

    2016-05-01

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

  10. Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water.

    PubMed

    Lozhkomoev, A S; Glazkova, E A; Bakina, O V; Lerner, M I; Gotman, I; Gutmanas, E Y; Kazantsev, S O; Psakhie, S G

    2016-05-20

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers. PMID:27053603

  11. Al-matrix composite materials reinforced by Al-Cu-Fe particles

    NASA Astrophysics Data System (ADS)

    Bonneville, J.; Laplanche, G.; Joulain, A.; Gauthier-Brunet, V.; Dubois, S.

    2010-07-01

    Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ω-Al00.70Cu0.20Fe0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/ω, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particul ar in yield stress values. In the low temperatureregime (T <= 570K), the yield stress of the Al/ω composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

  12. The new structure type Gd3Ni7Al14.

    PubMed

    Pukas, Svitlana; Gladyshevskii, Roman

    2015-11-01

    The crystal structure of Gd3Ni7Al14 (trigadolinium heptanickel tetradecaaluminide) belongs to a family of two-layer structures and can be described as an assembly of interpenetrating centred straight prisms. For the Ni atoms, trigonal prisms (Al4Gd2 and Al6) are observed, the Al atoms are inside tetragonal (Ni2Al2Gd4, Ni2Al4Gd2, Al4Gd4, Ni4Al4 and Al8) and pentagonal (Ni4Al6 and Al10) prisms, while the Gd atoms are at the centres of pentagonal (Ni4Al6) and hexagonal (Ni4Al8) prisms. In each case, the true coordination polyhedron is a capped prism, also including atoms from the same layer. The structural features of Gd3Ni7Al14 are similar to those of the intermetallides PrNi2Al3 and ZrNiAl. In all these structures, Ni-centred trigonal prisms form infinite columns via common triangular faces. The columns share prism edges and form a three-dimensional framework with six-membered rings in the (001) plane in the case of the PrNi2Al3 and ZrNiAl types. In the case of Gd3Ni7Al14, six-membered rings are also observed, but only two-thirds of the rings are interconnected via prism edges. PMID:26524174

  13. The new structure type Gd3Ni7Al14.

    PubMed

    Pukas, Svitlana; Gladyshevskii, Roman

    2015-11-01

    The crystal structure of Gd3Ni7Al14 (trigadolinium heptanickel tetradecaaluminide) belongs to a family of two-layer structures and can be described as an assembly of interpenetrating centred straight prisms. For the Ni atoms, trigonal prisms (Al4Gd2 and Al6) are observed, the Al atoms are inside tetragonal (Ni2Al2Gd4, Ni2Al4Gd2, Al4Gd4, Ni4Al4 and Al8) and pentagonal (Ni4Al6 and Al10) prisms, while the Gd atoms are at the centres of pentagonal (Ni4Al6) and hexagonal (Ni4Al8) prisms. In each case, the true coordination polyhedron is a capped prism, also including atoms from the same layer. The structural features of Gd3Ni7Al14 are similar to those of the intermetallides PrNi2Al3 and ZrNiAl. In all these structures, Ni-centred trigonal prisms form infinite columns via common triangular faces. The columns share prism edges and form a three-dimensional framework with six-membered rings in the (001) plane in the case of the PrNi2Al3 and ZrNiAl types. In the case of Gd3Ni7Al14, six-membered rings are also observed, but only two-thirds of the rings are interconnected via prism edges.

  14. Integrated predictive modelling simulations of burning plasma experiment designs

    NASA Astrophysics Data System (ADS)

    Bateman, Glenn; Onjun, Thawatchai; Kritz, Arnold H.

    2003-11-01

    Models for the height of the pedestal at the edge of H-mode plasmas (Onjun T et al 2002 Phys. Plasmas 9 5018) are used together with the Multi-Mode core transport model (Bateman G et al 1998 Phys. Plasmas 5 1793) in the BALDUR integrated predictive modelling code to predict the performance of the ITER (Aymar A et al 2002 Plasma Phys. Control. Fusion 44 519), FIRE (Meade D M et al 2001 Fusion Technol. 39 336), and IGNITOR (Coppi B et al 2001 Nucl. Fusion 41 1253) fusion reactor designs. The simulation protocol used in this paper is tested by comparing predicted temperature and density profiles against experimental data from 33 H-mode discharges in the JET (Rebut P H et al 1985 Nucl. Fusion 25 1011) and DIII-D (Luxon J L et al 1985 Fusion Technol. 8 441) tokamaks. The sensitivities of the predictions are evaluated for the burning plasma experimental designs by using variations of the pedestal temperature model that are one standard deviation above and below the standard model. Simulations of the fusion reactor designs are carried out for scans in which the plasma density and auxiliary heating power are varied.

  15. Horizontal vectorization of electron repulsion integrals.

    PubMed

    Pritchard, Benjamin P; Chow, Edmond

    2016-10-30

    We present an efficient implementation of the Obara-Saika algorithm for the computation of electron repulsion integrals that utilizes vector intrinsics to calculate several primitive integrals concurrently in a SIMD vector. Initial benchmarks display a 2-4 times speedup with AVX instructions over comparable scalar code, depending on the basis set. Speedup over scalar code is found to be sensitive to the level of contraction of the basis set, and is best for (lAlB|lClD) quartets when lD  = 0 or lB=lD=0, which makes such a vectorization scheme particularly suitable for density fitting. The basic Obara-Saika algorithm, how it is vectorized, and the performance bottlenecks are analyzed and discussed. © 2016 Wiley Periodicals, Inc. PMID:27620865

  16. Evidence that 26Al Did Not Melt Asteroids

    NASA Astrophysics Data System (ADS)

    Wasson, J. T.

    2016-08-01

    26Al/27Al initial ratios in achondrites are much lower than expected if 26Al was the only heat source responsible for melting the parental materials. Impacts provided a substantial fraction of the heat.

  17. Integration of the Antennal Lobe Glomeruli and Three Projection Neurons in the Standard Brain Atlas of the Moth Heliothis Virescens

    PubMed Central

    Løfaldli, Bjarte Bye; Kvello, Pål; Mustaparta, Hanna

    2010-01-01

    Digital three dimensional standard brain atlases (SBAs) are valuable tools for integrating neuroimaging data of different preparations. In insects, SBAs of five species are available, including the atlas of the female Heliothis virescens moth brain. Like for the other species, the antennal lobes (ALs) of the moth brain atlas were integrated as one material identity without internal structures. Different from the others, the H. virescens SBA exclusively included the glomerular layer of the AL. This was an advantage in the present study for performing a direct registration of the glomerular layer of individual preparations into the standard brain. We here present the H. virescens female SBA with a new model of the AL glomeruli integrated into the atlas, i.e. with each of the 66 glomeruli identified and labelled with a specific number. The new model differs from the previous H. virescens AL model both in respect to the number of glomeruli and the numbering system; the latter according to the system used for the AL atlases of two other heliothine species. For identifying female specific glomeruli comparison with the male AL was necessary. This required a new male AL atlas, included in this paper. As demonstrated by the integration of three AL projection neurons of different preparations, the new SBA with the integrated glomruli is a helpful tool for determining the glomeruli innervated as well as the relative position of the axonal projections in the protocerebrum. PMID:20179785

  18. Exothermic reactions in Co/Al nanolaminates

    NASA Astrophysics Data System (ADS)

    Adams, D. P.; Hodges, V. C.; Bai, M. M.; Jones, E.; Rodriguez, M. A.; Buchheit, T.; Moore, J. J.

    2008-08-01

    Vapor-deposited Co/Al nanolaminates having a net equiatomic stoichiometry exhibited rapid, high-temperature synthesis. When ignited locally, 7.5-μm-thick Co/Al foils were characterized by self-sustained propagating reactions with flame front speeds between ˜0.5 and 9 m/s. Speed was largely affected by bilayer thickness and premixed volume fraction, consistent with previous studies of other exothermic multilayers. Cobalt aluminide foils reacted by self-propagating synthesis developed a variety of rough surface morphologies characterized by a large amplitude (peak-to-valley ˜1.0 μm), multiperiod, wavelike structure. High-temperature reaction was also stimulated by rapid global heating. Tests revealed low ignition temperatures (Tig)˜240-460 °C compared with previous Co-Al powder reactant experiments. Ignition temperature was influenced by bilayer thickness. All foils ignited by global heating and those reacted in a self-propagating mode developed a single-phase B2 (CsCl-type) crystal structure. Thick Co/Al nanolaminates were used successfully to join a few different materials including metalized Al2O3 (by soldering) and polyetheretherketone (by direct attachment).

  19. Integrated assessment briefs

    SciTech Connect

    1995-04-01

    Integrated assessment can be used to evaluate and clarify resource management policy options and outcomes for decision makers. The defining characteristics of integrated assessment are (1) focus on providing information and analysis that can be understood and used by decision makers rather than for merely advancing understanding and (2) its multidisciplinary approach, using methods, styles of study, and considerations from a broader variety of technical areas than would typically characterize studies produced from a single disciplinary standpoint. Integrated assessment may combine scientific, social, economic, health, and environmental data and models. Integrated assessment requires bridging the gap between science and policy considerations. Because not everything can be valued using a single metric, such as a dollar value, the integrated assessment process also involves evaluating trade-offs among dissimilar attributes. Scientists at Oak Ridge National Laboratory (ORNL) recognized the importance and value of multidisciplinary approaches to solving environmental problems early on and have pioneered the development of tools and methods for integrated assessment over the past three decades. Major examples of ORNL`s experience in the development of its capabilities for integrated assessment are given.

  20. Fabrication and characterization of an undoped GaAs/AlGaAs quantum dot device

    SciTech Connect

    Li, Hai-Ou; Cao, Gang; Xiao, Ming You, Jie; Wei, Da; Tu, Tao; Guo, Guang-Can; Guo, Guo-Ping; Jiang, Hong-Wen

    2014-11-07

    We demonstrate the development of a double quantum dot with an integrated charge sensor fabricated in undoped GaAs/AlGaAs heterostructures using a double top-gated design. Based on the evaluation of the integrated charge sensor, the double quantum dot can be tuned to a few-electron region. Additionally, the inter-dot coupling of the double quantum dot can be tuned to a large extent according to the voltage on the middle gate. The quantum dot is shown to be tunable from a single dot to a well-isolated double dot. To assess the stability of such design, the potential fluctuation induced by 1/f noise was measured. Based on the findings herein, the quantum dot design developed in the undoped GaAs/AlGaAs semiconductor shows potential for the future exploitation of nano-devices.

  1. Human-technology Integration

    NASA Astrophysics Data System (ADS)

    Mullen, Katharine M.

    Human-technology integration is the replacement of human parts and extension of human capabilities with engineered devices and substrates. Its result is hybrid biological-artificial systems. We discuss here four categories of products furthering human-technology integration: wearable computers, pervasive computing environments, engineered tissues and organs, and prosthetics, and introduce examples of currently realized systems in each category. We then note that realization of a completely artificial sytem via the path of human-technology integration presents the prospect of empirical confirmation of an aware artificially embodied system.

  2. Ethics and academic integrity.

    PubMed

    Milton, Constance L

    2015-01-01

    Academics from across the globe must navigate ever-increasing demands for research, practice, and educational productivity. With the increased demands, nurse faculty must choose value priorities and actions that reflect academic integrity. What does it mean to choose actions that reflect personal integrity in the academic arena? This article begins an important nursing philosophical and theoretical discussion that members and future members of the discipline of nursing must reflect upon and grapple with as they consider what it potentially means to act with straight thinking and integrity in academics. PMID:25520458

  3. GMRES and integral operators

    SciTech Connect

    Kelley, C.T.; Xue, Z.Q.

    1994-12-31

    Many discretizations of integral equations and compact fixed point problems are collectively compact and strongly convergent in spaces of continuous functions. These properties not only lead to stable and convergent approximations but also can be used in the construction of fast multilevel algorithms. Recently the GMRES algorithm has become a standard coarse mesh solver. The purpose of this paper is to show how the special properties of integral operators and their approximations are reflected in the performance of the GMRES iteration and how these properties can be used to strengthen the norm in which convergence takes place. The authors illustrate these ideas with composite Gauss rules for integral equations on the unit interval.

  4. The Integration Paradox

    PubMed Central

    Verkuyten, Maykel

    2016-01-01

    The integration paradox refers to the phenomenon of the more highly educated and structurally integrated immigrants turning away from the host society, rather than becoming more oriented toward it. This article provides an overview of the empirical evidence documenting this paradox in the Netherlands. In addition, the theoretical arguments and the available findings about the social psychological processes involved in this paradox are considered. The existing evidence for the integration paradox and what might explain it form the basis for making suggestion for future theoretical work and empirical research, and for discussing possible policy implications. PMID:27152028

  5. Oscillatory surface relaxations in Ni, Al, and their ordered alloys

    SciTech Connect

    Chen, S.P.; Voter, A.F.; Srolovitz, D.J.

    1986-09-15

    Results from simulations of Ni, Al, Ni/sub 3/Al, and NiAl show long-range, oscillatory surface relaxations that decay exponentially into the bulk. Pure fcc Ni and Al have oscillation periods that are close to the nearest-neighbor distance, independent of crystal face. This is shown to be due to surface smoothing and steric effects. In Ni/sub 3/Al and NiAl, the surface planes are rippled, with the Ni-Ni and Al-Al interlayer spacings oscillating 180/sup 0/ out of phase. Very good agreement between our results and experimentally measured atomic relaxations is obtained.

  6. The mechanical properties of FeAl

    SciTech Connect

    Baker, I.; George, E.P.

    1996-12-31

    Only in the last few years has progress been made in obtaining reproducible mechanical properties data for FeAl. Two sets of observations are the foundation of this progress. The first is that the large vacancy concentrations that exist in FeAl at high temperature are easily retained at low temperature and that these strongly affect the low-temperature mechanical properties. The second is that RT ductility is adversely affected by water vapor. Purpose of this paper is not to present a comprehensive overview of the mechanical properties of FeAl but rather to highlight our understanding of key phenomena and to show how an understanding of the factors which control the yield strength and fracture behavior has followed the discovery of the above two effects. 87 refs, 9 figs.

  7. Boron strengthening in FeAl

    SciTech Connect

    Baker, I.; Li, X.; Xiao, H.; Klein, O.; Nelson, C.; Carleton, R.L.; George, E.P.

    1998-11-01

    The effect of boron on the strength of B2-structured FeAl is considered as a function of composition, grain size and temperature. Boron does not affect the concentrations of antisite atoms or vacancies present, with the former increasing and the latter decreasing with increasing deviation from the stoichiometric composition. When vacancies are absent, the strength increase per at. % B per unit lattice strain, {Delta}{sigma}/({Delta}c x {epsilon}) increases with increasing aluminum concentration, but when vacancies are present (>45 at. % Al), {Delta}{sigma}/({Delta}c x {epsilon}) decreases again. Boron increases grain size strengthening in FeAl. B strengthening is roughly independent of temperature up to the yield strength peak but above the point, when diffusion-assisted deformation occurs, boron strengthening increases dramatically.

  8. Characterization of Al-Cu-Mg-Ag Alloy RX226-T8 Plate

    NASA Technical Reports Server (NTRS)

    Lach, Cynthia L.; Domack, Marcia S.

    2003-01-01

    aircraft wing and fuselage skin materials through the addition of silver to Al-Cu-Mg alloys based on Al 2519 chemistry [2]. Thermal stability of the resulting Al-Cu-Mg-Ag alloys, C415-T8 and C416-T8, was due to co-precipitation of the thermally stable . (AlCu) and ' (Al2Cu) strengthening phases [1-4]. The strength and toughness behavior was investigated for these alloys produced as 0.090-inch thick rolled sheet in the T8 condition and after various thermal exposures. The mechanical properties were shown to be competitive with conventional aircraft alloys, 2519-T8 and 2618-T8 [2]. During the Integral Airframe Structure (IAS) program, advanced aluminum alloys were examined for use in an integrally stiffened airframe structure where the skin and stiffeners would be machined from plate and extruded frames would be mechanically attached (see Figure 1) [5]. Advantages of integrally stiffened structure include reduced part count, and reduced assembly times compared to conventional built-up airframe structure. The near-surface properties of a thick plate are of significance for a machined integrally stiffened airframe structure since this represents the skin location. Properties measured at the mid-plane of the plate are more representative of the stiffener web. RX226 was developed to exploit strength-toughness improvements and thermal stability benefits of Al-Cu-Mg-Ag alloys in plate gages. This study evaluated the microstructure and properties of three gages of plate produced in the T8 condition.

  9. Optimal control of AlAs oxidation via digital alloy heterostructure compositions

    NASA Astrophysics Data System (ADS)

    Suárez, I.; Almuneau, G.; Condé, M.; Arnoult, A.; Fontaine, C.

    2009-09-01

    A thorough study of wet thermal oxidation in AlAs/AlxGa1-xAs superlattices is presented. The results shown here demonstrate that the final oxidation depth can be finely tuned via the composition and thickness of AlxGa1-xAs into the digital alloy. A complete model of oxidation in these structures is proposed, relying on diffusion through the AlAs layer, its oxidation and an additional effect due to the AlxGa1-xAs intermediate barriers. This barrier contribution is shown to further improve the control of the oxidation rate, and thereby fabrication of sophisticated AlOx/GaAs integrated optoelectronic devices.

  10. Experimental Research on Ultrasonic Vibration Milling Metal Matrix Composites SiCp/Al

    SciTech Connect

    Gao, G. F.; Zhao, B.; Xiang, D. H.; Zhao, M. L.

    2011-01-17

    Although particle reinforced metal matrix composites possess excellent physical properties, its machining performance is rather bad because of its specific structure. It is difficult to obtain good cutting effect by traditional machining method. So machining has become the bottleneck which strictly restricts its industry application. This paper mainly focuses on both wear characteristics of different tool materials and material removal mechanism in ultrasonic milling high volume fraction particle reinforced metal matrix composites SiCp/Al. An acoustic device for ultrasonic vibration milling was developed to introduce the ultrasonic vibration into the traditional machining process. Through the contrast experiment of traditional milling and ultrasonic vibration milling SiCp/Al, the mechanism of tool wear and characteristics of surface topography were analyzed. The experimental results showed that the surface integrity and tool life in the ultrasonic vibration milling SiCp/Al were improved.

  11. Advanced launch system (ALS) actuation and power systems impact operability and cost

    SciTech Connect

    Sundberg, G.R. . Lewis Research Center)

    1990-09-01

    To obtain the advanced launch system (ALS) primary goals of reduced costs ($300/lb earth to LEO) and improved operability, there must be significant reductions in the launch operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using electrical actuation integrated with a single vehicle electrical power system and controls for all actuation and avionics requirements. This paper reviews the ALS and its associated advanced development program to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the ALS goals (cryogenic fuel valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles and a multitude of commercial applications.

  12. [Al-Biruni--a universal scientist].

    PubMed

    Kujundzić, E; Masić, I

    1999-01-01

    Al-Biruni's was of Persian descent. He was born in Horesmiya and had studied mathematics, history and medicine. Acquiring knowledge from these sciences, he wrote an outstanding work on chronology of several nations and devoted it to Ziyarit ruler Kabus. He made a chronological overview of calendars from many nations, including Persians, Greeks, Egyptians, Jews, Melkitian and Nestorian Christians, Sabeyaans as well as the old Arabs. Data presented in the work, according to the later authors, were taken from very reliable sources. He was contemporary of Ibn-Sina, and thanks to their friendship, they have discussed very much miscellaneous topics. He belonged to the group of scholars, taken by Gaznevian Soultan Mahmud to a long journey to India. Afterwards Al-Biruni wrote and published detailed work "Description of India"--a work on cultural history of India. Due to excellent abilities of Al-Biruni as a philosopher and scholar, there are still significant and reliable notes about buddhistic philosophy, structure of castes and Brahmans' life style. In this Al-Biruni's masterpiece, there are many comparative analysis of Suffism and certain Indian philosophical methods. Al-Biruni's most important work is "Pharmacopoeia"--"Kitab al-saydala", which brilliantly describes all medicaments. This work has been published in many languages. He also wrote few works on astronomy and astrology. In those works he has explained some astrological events through scientific approach in a such peculiar way that nobody has ever explained before. He was also interested in sciences like geology, mineralology, geography, mathematics, psychology and many others. PMID:10386051

  13. UBVRI Photometry of Mecury's Integral Phase Curve

    NASA Astrophysics Data System (ADS)

    Bergfors, Carolina; Warell, J.

    2007-10-01

    We present results from a photometric survey of Mecury's survey of Mecury's integral phase curve in the Johnson UBVRI system, obtained with the 0.9-m Westerlund Telescope in Uppsala, Sweden. CCD observations of the integrated disk have been obtained for the phase angle range 22-152 degrees. This is the first integral phase curve survey covering the extended visible spectrum of Mecury. We have derived absolute magnitudes and color indices from which Bond albedo, geometric albedo and phase integral have been determined for all bands. We have fitted the data in each band with the Mallama et a. (2002) V-band phase curve which is based on a wider range of more densely sampled phase angles. A magnitude-scaled Mallama phase curve provided adequate fits for each band within the photometric error budget. This implies no evidence of phase reddening in any color, which is in contrast to the Moon. The phase reddening for the Moon was determined by Lane and Irvine (1973) to 0.001 mag/degree between the wavelengths 445 nm and 550 nm. These data will be modeled to derive light scattering properties of the regolith. Of particular interest is the prediction of a disk-averaged normal albedo at 1064 nm with implications for the returned signal strength of the BepiColombo laser altimeter BELA (Gunderson et al, 2006).

  14. Geometric integration of the Vlasov-Maxwell system with a variational particle-in-cell scheme

    SciTech Connect

    Squire, J.; Tang, W. M.; Qin, H.

    2012-08-15

    A fully variational, unstructured, electromagnetic particle-in-cell integrator is developed for integration of the Vlasov-Maxwell equations. Using the formalism of discrete exterior calculus [Desbrun et al., e-print arXiv:math/0508341 (2005)], the field solver, interpolation scheme, and particle advance algorithm are derived through minimization of a single discrete field theory action. As a consequence of ensuring that the action is invariant under discrete electromagnetic gauge transformations, the integrator exactly conserves Gauss's law.

  15. Geometric integration of the Vlasov-Maxwell system with a variational particle-in-cell scheme

    NASA Astrophysics Data System (ADS)

    Squire, J.; Qin, H.; Tang, W. M.

    2012-08-01

    A fully variational, unstructured, electromagnetic particle-in-cell integrator is developed for integration of the Vlasov-Maxwell equations. Using the formalism of discrete exterior calculus [Desbrun et al., e-print arXiv:math/0508341 (2005)], the field solver, interpolation scheme, and particle advance algorithm are derived through minimization of a single discrete field theory action. As a consequence of ensuring that the action is invariant under discrete electromagnetic gauge transformations, the integrator exactly conserves Gauss's law.

  16. Design, Optimization and Evaluation of Integrally Stiffened Al 7050 Panel with Curved Stiffeners

    NASA Technical Reports Server (NTRS)

    Slemp, Wesley C. H.; Bird, R. Keith; Kapania, Rakesh K.; Havens, David; Norris, Ashley; Olliffe, Robert

    2011-01-01

    A curvilinear stiffened panel was designed, manufactured, and tested in the Combined Load Test Fixture at NASA Langley Research Center. The panel was optimized for minimum mass subjected to constraints on buckling load, yielding, and crippling or local stiffener failure using a new analysis tool named EBF3PanelOpt. The panel was designed for a combined compression-shear loading configuration that is a realistic load case for a typical aircraft wing panel. The panel was loaded beyond buckling and strains and out-of-plane displacements were measured. The experimental data were compared with the strains and out-of-plane deflections from a high fidelity nonlinear finite element analysis and linear elastic finite element analysis of the panel/test-fixture assembly. The numerical results indicated that the panel buckled at the linearly elastic buckling eigenvalue predicted for the panel/test-fixture assembly. The experimental strains prior to buckling compared well with both the linear and nonlinear finite element model.

  17. Design, Optimization, and Evaluation of Integrally-Stiffened Al-2139 Panel with Curved Stiffeners

    NASA Technical Reports Server (NTRS)

    Havens, David; Shiyekar, Sandeep; Norris, Ashley; Bird, R. Keith; Kapania, Rakesh K.; Olliffe, Robert

    2011-01-01

    A curvilinear stiffened panel was designed, manufactured, and tested in the Combined Load Test Fixture at NASA Langley Research Center. The panel is representative of a large wing engine pylon rib and was optimized for minimum mass subjected to three combined load cases. The optimization included constraints on web buckling, material yielding, crippling or local stiffener failure, and damage tolerance using a new analysis tool named EBF3PanelOpt. Testing was performed for the critical combined compression-shear loading configuration. The panel was loaded beyond initial buckling, and strains and out-of-plane displacements were extracted from a total of 20 strain gages and 6 linear variable displacement transducers. The VIC-3D system was utilized to obtain full field displacements/strains in the stiffened side of the panel. The experimental data were compared with the strains and out-of-plane deflections from a high fidelity nonlinear finite element analysis. The experimental data were also compared with linear elastic finite element results of the panel/test-fixture assembly. Overall, the panel buckled very near to the predicted load in the web regions.

  18. Integrating contingency management with relapse prevention skills: comment on Silverman et al. (2001).

    PubMed

    Marlatt, G A

    2001-02-01

    The study by K. Silverman, D. Svikis, E. Robles, M. L. Stitzer, and G. E. Bigelow (2001) demonstrates the effectiveness of a voucher-based reinforcement intervention in the treatment of pregnant women in treatment for substance abuse. The effects of prolonged initial abstinence as a form of "sobriety sampling" may serve to enhance long-term recovery by providing patients with rewards for maintaining abstinence. Several limitations to the study are addressed, including selection of the treatment sample and the absence of any follow-up data on drug use or relapse following completion of the 24-week treatment program. Recommendations are made to enhance maintenance of abstinence by providing coping-skill training for relapse prevention as an addition to the contingency management approach.

  19. 75 FR 53355 - The Integrity Funds, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... management investment companies to enter into and materially amend subadvisory agreements without shareholder...'') (each, a ``Mutual Fund'' and collectively, the ``Mutual Funds''), and Viking Fund Management, LLC (the...., Washington, DC 20549-1090. Applicants, Viking Fund Management, LLC, 1 Main Street North, Minot, North...

  20. Individual two level fluctuators in the tunneling conductance of Al/AlOx/Al Josephson junctions for superconducting qubits

    NASA Astrophysics Data System (ADS)

    Nugroho, Christopher; Orlyanchik, Vladimir; van Harlingen, Dale

    2014-03-01

    Two level system (TLS) defects in AlOx tunnel barriers can lead to low-frequency 1 / f critical current noise and losses in coherent superconducting circuits. Understanding the nature of these defects and how to eliminate them are critical in order to achieve ultra-long coherence times. We present measurements of the tunneling conductance of ultrasmall, A <(100nm) 2 , Al/AlOx/Al shadow evaporated junctions. The tunneling conductance of these junctions exhibits several isolated TLSs, which permitted the detailed analysis of the individual switching rates and behavior of the TLSs. We have studied the thermal activation behavior of these TLSs, and in some cases observe a crossover into quantum-limited tunneling at lower temperatures. Tracking the TLS switching rates as a function of the applied voltage bias provides an estimate of the TLS charge dipole moment. In some quantum tunneling limited TLSs we have observed a non-equilibrium enhancement of the switching rates that cannot be explained by simple dissipative heating of the TLSs. Further investigations into these TLS defects may lead to the identification of their physical origins and strategies to eliminate them. Research funded by the Intelligence Advanced Research Projects Activity (IARPA).

  1. Cotangent Models for Integrable Systems

    NASA Astrophysics Data System (ADS)

    Kiesenhofer, Anna; Miranda, Eva

    2016-07-01

    We associate cotangent models to a neighbourhood of a Liouville torus in symplectic and Poisson manifolds focusing on b-Poisson/b-symplectic manifolds. The semilocal equivalence with such models uses the corresponding action-angle theorems in these settings: the theorem of Liouville-Mineur-Arnold for symplectic manifolds and an action-angle theorem for regular Liouville tori in Poisson manifolds (Laurent- Gengoux et al., IntMath Res Notices IMRN 8: 1839-1869, 2011). Our models comprise regular Liouville tori of Poisson manifolds but also consider the Liouville tori on the singular locus of a b-Poisson manifold. For this latter class of Poisson structures we define a twisted cotangent model. The equivalence with this twisted cotangent model is given by an action-angle theorem recently proved by the authors and Scott (Math. Pures Appl. (9) 105(1):66-85, 2016). This viewpoint of cotangent models provides a new machinery to construct examples of integrable systems, which are especially valuable in the b-symplectic case where not many sources of examples are known. At the end of the paper we introduce non-degenerate singularities as lifted cotangent models on b-symplectic manifolds and discuss some generalizations of these models to general Poisson manifolds.

  2. Global and Local Mechanical Properties of Autogenously Laser Welded Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Cao, Xinjin; Kabir, Abu Syed H.; Wanjara, Priti; Gholipour, Javad; Birur, Anand; Cuddy, Jonathan; Medraj, Mamoun

    2013-11-01

    Ti-6Al-4V sheets, 3.2-mm in thickness, were butt welded using a continuous wave 4 kW Nd:YAG laser welding system. The effect of two main process parameters, laser power and welding speed, on the joint integrity was characterized in terms of the joint geometry, defects, microstructure, hardness, and tensile properties. In particular, a digital image correlation technique was used to determine the local tensile properties of the welds. It was determined that a wide range of heat inputs can be used to fully penetrate the Ti-6Al-4V butt joints during laser welding. At high laser power levels, however, significant defects such as underfill and porosity, can occur and cause marked degradation in the joint integrity and performance. At low welding speeds, however, significant porosity occurs due to its growth and the potential collapse of instable keyholes. Intermediate to relatively high levels of heat input allow maximization of the joint integrity and performance by limiting the underfill and porosity defects. In considering the effect of the two main defects on the joint integrity, the underfill defect was found to be more damaging to the mechanical performance of the weldment than the porosity. Specifically, it was determined that the maximum tolerable underfill depth for Ti-6Al-4V is approximately 6 pct of the workpiece thickness, which is slightly stricter than the value of 7 pct specified in AWS D17.1 for fusion welding in aerospace applications. Hence, employing optimized laser process parameters allows the underfill depth to be maintained within the tolerable limit (6 pct), which in turn prevents degradation in both the weld strength and ductility. To this end, the ability to maintain weld ductility in Ti-6Al-4V by means of applying a high energy density laser welding process presents a significant advantage over conventional arc welding for the assembly of aerospace components.

  3. 22 W coherent GaAlAs amplifier array with 400 emitters

    NASA Technical Reports Server (NTRS)

    Krebs, D.; Herrick, R.; No, K.; Harting, W.; Struemph, F.

    1991-01-01

    Greater than 22 W of optical power has been demonstrated from a multiple-emitter, traveling-wave semiconductor amplifier, with approximately 87 percent of the output at the frequency of the injection source. The device integrates, in AlGaAs graded-index separate-confinement heterostructure single quantum well (GRINSCH-SQW) epitaxy, 400 ridge waveguide amplifiers with a coherent optical signal distribution circuit on a 12 x 6 mm chip.

  4. Complementary and Alternative Therapies in ALS

    PubMed Central

    Bedlack, Richard S.; Joyce, Nanette; Carter, Gregory T.; Pagononi, Sabrina; Karam, Chafic

    2015-01-01

    Synopsis Given the severity of their illness and lack of effective disease modifying agents, it is not surprising that most patients with ALS consider trying complementary and alternative therapies. Some of the most commonly considered alternative therapies include special diets, nutritional supplements, cannabis, acupuncture, chelation and energy healing. This chapter reviews these in detail. We also describe 3 models by which physicians may frame discussions about alternative therapies: paternalism, autonomy and shared decision making. Finally, we review a program called ALSUntangled which using shared shared decision making to review alternative therapies for ALS. PMID:26515629

  5. A Comment on Eerland et al. (2016).

    PubMed

    Hart, William

    2016-03-01

    People imagine criminal behavior in greater detail and ascribe more blame to criminals when a description of a crime is written using the imperfective verb aspect (Hart & Albarracín, 2011, Experiment 3). An initiative to reproduce these findings conducted by Eerland et al. (2016) yielded a lack of replication. Eerland et al. have suggested that the original effect was likely driven by a Type I error produced by methodological aspects of the experiment, including low sample size. Recent conceptual replications of Hart and Albarracín's effect (Sherrill, Eerland, Zwaan, & Magliano, 2015), however, might imply the effect could be contingent on sample characteristics. PMID:26993281

  6. Fabrication and Characterization of AL-AL4C3 Nanocomposite by Mechanical Alloying

    NASA Astrophysics Data System (ADS)

    Mohammad Sharifi, E.; Enayati, M. H.; Karimzadeh, F.

    Aluminum carbide (Al4C3) seems to be an ideal reinforcement for producing aluminum matrix composites. Al4C3 has high hardness and shear strength as well as a high melting point. The dispersion of Al4C3 particles in the matrix produces a pinning effect that reduces aluminum grain growth, which improves the mechanical properties. In this study, aluminum powders were mixed with 4.5 wt.% graphite and mechanically alloyed using a high-energy ball mill in order to produce Al-Al4C3 nanocomposite. The structural evaluation of powder particles after different milling times was studied by X-ray diffractometry, scanning electron microscopy and microhardness measurements. The aluminum crystallite size estimated with broadening of XRD peaks by Williamson-Hall formula. XRD results suggested that the grain size of aluminum decreased to nanometer range (30 nm) during ball milling. No Al4C3 formed during the mechanical alloying process. Milled powders were then annealed at 300-600 °C for 1 h under argon atmosphere. Annealing at temperatures higher than 300 °C led to formation of Al4C3 phase which increased as annealing temperature increased. Aluminum grain size remained in nanometer range after annealing process. The microhardness of powder particles increased after annealing. Both effects are due to the formation of nanosized Al4C3 particles.

  7. Melting, Processing, and Properties of Disordered Fe-Al and Fe-Al-C Based Alloys

    NASA Astrophysics Data System (ADS)

    Satya Prasad, V. V.; Khaple, Shivkumar; Baligidad, R. G.

    2014-09-01

    This article presents a part of the research work conducted in our laboratory to develop lightweight steels based on Fe-Al alloys containing 7 wt.% and 9 wt.% aluminum for construction of advanced lightweight ground transportation systems, such as automotive vehicles and heavy-haul truck, and for civil engineering construction, such as bridges, tunnels, and buildings. The melting and casting of sound, porosity-free ingots of Fe-Al-based alloys was accomplished by a newly developed cost-effective technique. The technique consists of using a special flux cover and proprietary charging schedule during air induction melting. These alloys were also produced using a vacuum induction melting (VIM) process for comparison purposes. The effect of aluminum (7 wt.% and 9 wt.%) on melting, processing, and properties of disordered solid solution Fe-Al alloys has been studied in detail. Fe-7 wt.% Al alloy could be produced using air induction melting with a flux cover with the properties comparable to the alloy produced through the VIM route. This material could be further processed through hot and cold working to produce sheets and thin foils. The cold-rolled and annealed sheet exhibited excellent room-temperature ductility. The role of carbon in Fe-7 wt.% Al alloys has also been examined. The results indicate that Fe-Al and Fe-Al-C alloys containing about 7 wt.% Al are potential lightweight steels.

  8. Transport mechanisms of leakage current in Al2O3/InAlAs MOS capacitors

    NASA Astrophysics Data System (ADS)

    Jin, Chengji; Lu, Hongliang; Zhang, Yimen; Zhang, Yuming; Guan, He; Wu, Lifan; Lu, Bin; Liu, Chen

    2016-09-01

    An Al2O3 layer is inserted between the InAlAs layer and the metal gate in InAs/AlSb HEMTs to suppress the leakage current. The transport mechanisms of leakage current in Al2O3/InAlAs metal-oxide-semiconductor (MOS) capacitors at both positive and negative biases at different temperatures ranging from 10 °C to 70 °C are investigated. For positive bias, the leakage current is dominated by Schottky emission. Based on the fitted straight lines, the relative dielectric constant of Al2O3 and the barrier height between Al2O3 and InAlAs are extracted. However, for negative bias, the leakage current is dominated by Frenkel-Poole (F-P) emission and the depth of the trap energy level from the conduction band (ϕt) is extracted. Furthermore, authors explain the reason why the dominating mechanisms at positive and negative biases are different.

  9. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    DOEpatents

    Deevi, Seetharama C.; Sikka, Vinod K.

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  10. Directional Solidification and Mechanical Properties of NiAl-NiAlTa Alloys

    NASA Technical Reports Server (NTRS)

    Johnson, D. R.; Chen, X. F.; Oliver, B. F.; Noebe, R. D.; Whittenberger, J. D.

    1995-01-01

    Directional solidification of eutectic alloys is a promising technique for producing in-situ composite materials exhibiting a balance of properties. Consequently, the microstructure, creep strength and fracture toughness of directionally solidified NiAl-NiAlTa alloys were investigated. Directional solidification was performed by containerless processing techniques to minimize alloy contamination. The eutectic composition was found to be NiAl-15.5 at% Ta and well-aligned microstructures were produced at this composition. A near-eutectic alloy of NiAl-14.5Ta was also investigated. Directional solidification of the near-eutectic composition resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The off-eutectic alloy exhibited promising compressive creep strengths compared to other NiAl-based intermetallics, while preliminary testing indicated that the eutectic alloy was competitive with Ni-base single crystal superalloys. The room temperature toughness of these two-phase alloys was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa.

  11. Characterization of nanophase Al-oxide/Al powders by electron energy-loss spectroscopy.

    PubMed

    Fernández; Sánchez-López; Caballero; Martin; Vacher; Ponsonnet

    1998-08-01

    Al nanoparticles were prepared by the inert gas condensation method. After passivation with oxygen and air exposure we obtained a powdered sample of an Al-oxide/Al nanocomposite material. In the present paper we describe the use of the electron energy-loss spectroscopy (EELS) technique in a transmission electron microscope to characterize such nanostructured powders compared with a microcrystalline commercial aluminium foil. Energy-filtered images showed the presence of an alumina overlayer of approximately 4 nm covering the aluminium nanoparticles (23 nm in diameter). EELS analysis enabled us to determine the total amount of Al2O3 and metallic Al and the structure of the alumina passivation overlayer in the sample. In particular, the extended energy-loss fine structure analysis of the data showed a major presence of Al tetrahedrally coordinated with oxygen in the alumina passivation layer of Al nanoparticles instead of the octahedral coordination found for a conventional Al foil. This surprising effect has been attributed to the nanoscopic character of the grains. The analysis of the electron-loss near-edge structure also determines the presence of a certain degree of aggregation in this kind of powdered sample as result of the coalescence of the nanocrystalline grains. The procedure presented here may have the potential to solve other problems during characterization of nanostructured materials.

  12. Temporal integration of sensory evidence for saccade target selection.

    PubMed

    Ludwig, Casimir J H

    2009-11-01

    Perceptual decision-making may be viewed as a process of integrating sensory evidence over time to a response threshold. Ludwig et al. (2005b) argued against an integration to threshold account for saccadic eye movement decisions based on data from a stochastic contrast discrimination task. They argued that evidence integration was time-limited, with the deadline being independent from the quality of the sensory evidence. In this study, the data from Ludwig et al. (2005b) were fit with a model in which sensory evidence is integrated to a time-varying threshold. The functional form of the threshold variation allowed the model to approximate a constant threshold as well as an abrupt deadline. Sensory evidence was computed on the basis of a temporally blurred representation of the stimulus sequence. The model provides an overall good fit to the latency and accuracy data. Its predictions are consistent with a short window of evidence integration, as proposed in the original study. The model produces qualitatively correct predictions for an experiment in which the availability of sensory evidence is varied systematically. Inspection of the model parameters, however, shows that integration was not terminated by an abrupt deadline, although a rather gradual deadline signal improved the fit for some observers.

  13. Integrative Perspectives on Acculturation

    ERIC Educational Resources Information Center

    Killian, Caitlin

    2011-01-01

    Comments on the original article, "Rethinking the concept of acculturation: Implications for theory and research," by S. J. Schwartz, J. B. Unger, B. L. Zamboanga, and J. Szapocznik. Schwartz et al are to be commended for their attempts "to propose an expanded, multidimensional model of acculturation and of the demographic and contextual forces…

  14. ELECTRONIC INTEGRATING CIRCUIT

    DOEpatents

    Englemann, R.H.

    1963-08-20

    An electronic integrating circuit using a transistor with a capacitor connected between the emitter and collector through which the capacitor discharges at a rate proportional to the input current at the base is described. Means are provided for biasing the base with an operating bias and for applying a voltage pulse to the capacitor for charging to an initial voltage. A current dividing diode is connected between the base and emitter of the transistor, and signal input terminal means are coupled to the juncture of the capacitor and emitter and to the base of the transistor. At the end of the integration period, the residual voltage on said capacitor is less by an amount proportional to the integral of the input signal. Either continuous or intermittent periods of integration are provided. (AEC)

  15. INTEGRAL and Cataclysmic Variables

    SciTech Connect

    Hudec, R.; Blazek, M.; Galis, R.; Kocka, M.

    2010-07-15

    The results of investigations of cataclysmic variables (CVs) with the ESA INTEGRAL satellite are briefly presented and discussed. It is evident that the satellite serves as an efficient tool to study some of these objects.

  16. Integrated Flywheel Technology, 1983

    NASA Technical Reports Server (NTRS)

    Keckler, C. R. (Editor); Rodriguez, G. E. (Editor); Groom, N. J. (Editor)

    1983-01-01

    Topics of discussion included: technology assessment of the integrated flywheel systems, potential of system concepts, identification of critical areas needing development and, to scope and define an appropriate program for coordinated activity.

  17. Retroviral DNA Integration

    PubMed Central

    2016-01-01

    The integration of a DNA copy of the viral RNA genome into host chromatin is the defining step of retroviral replication. This enzymatic process is catalyzed by the virus-encoded integrase protein, which is conserved among retroviruses and LTR-retrotransposons. Retroviral integration proceeds via two integrase activities: 3′-processing of the viral DNA ends, followed by the strand transfer of the processed ends into host cell chromosomal DNA. Herein we review the molecular mechanism of retroviral DNA integration, with an emphasis on reaction chemistries and architectures of the nucleoprotein complexes involved. We additionally discuss the latest advances on anti-integrase drug development for the treatment of AIDS and the utility of integrating retroviral vectors in gene therapy applications. PMID:27198982

  18. Payload missions integration

    NASA Technical Reports Server (NTRS)

    Mitchell, R. A. K.

    1983-01-01

    Highlights of the Payload Missions Integration Contract (PMIC) are summarized. Spacelab Missions no. 1 to 3, OSTA partial payloads, Astro-1 Mission, premission definition, and mission peculiar equipment support structure are addressed.

  19. Managing for Organizational Integrity.

    ERIC Educational Resources Information Center

    Paine, Lynn Sharp

    1994-01-01

    Compliance-based ethics programs focus on prevention, detection, and punishment. Companies should adopt an integrity-based approach to ethics management that combines a concern for the law with an emphasis on managerial responsibility for ethical behavior. (JOW)

  20. Aviation Data Integration System

    NASA Technical Reports Server (NTRS)

    Kulkarni, Deepak; Wang, Yao; Windrem, May; Patel, Hemil; Keller, Richard

    2003-01-01

    During the analysis of flight data and safety reports done in ASAP and FOQA programs, airline personnel are not able to access relevant aviation data for a variety of reasons. We have developed the Aviation Data Integration System (ADIS), a software system that provides integrated heterogeneous data to support safety analysis. Types of data available in ADIS include weather, D-ATIS, RVR, radar data, and Jeppesen charts, and flight data. We developed three versions of ADIS to support airlines. The first version has been developed to support ASAP teams. A second version supports FOQA teams, and it integrates aviation data with flight data while keeping identification information inaccessible. Finally, we developed a prototype that demonstrates the integration of aviation data into flight data analysis programs. The initial feedback from airlines is that ADIS is very useful in FOQA and ASAP analysis.

  1. Wellbore Integrity Network

    SciTech Connect

    Carey, James W.; Bachu, Stefan

    2012-06-21

    In this presentation, we review the current state of knowledge on wellbore integrity as developed in the IEA Greenhouse Gas Programme's Wellbore Integrity Network. Wells are one of the primary risks to the successful implementation of CO{sub 2} storage programs. Experimental studies show that wellbore materials react with CO{sub 2} (carbonation of cement and corrosion of steel) but the impact on zonal isolation is unclear. Field studies of wells in CO{sub 2}-bearing fields show that CO{sub 2} does migrate external to casing. However, rates and amounts of CO{sub 2} have not been quantified. At the decade time scale, wellbore integrity is driven by construction quality and geomechanical processes. Over longer time-scales (> 100 years), chemical processes (cement degradation and corrosion) become more important, but competing geomechanical processes may preserve wellbore integrity.

  2. Integrated Programs Bibliography.

    ERIC Educational Resources Information Center

    Russell, Connie; Klassen, Aynsley

    2002-01-01

    Lists 58 journal articles and books, published 1989-2002, on integrated programs at the secondary level. Categories are: updates on the Ontario scene, suggestions for teachers, assessment, research, and program descriptions. (SV)

  3. Building an Integrated Study

    ERIC Educational Resources Information Center

    Collins, Myrtle T.; Greenberg, Marvin

    1974-01-01

    Article described a plan to develop integrated study through music activities. Students learned to become more independent learners while concentrating on more complex and creative activities. (Author/RK)

  4. Silicon-electroceramics integration

    SciTech Connect

    Tuller, H.L.

    1996-12-31

    Electroceramics provides unique functionality as sensors, transducers, and non-volatile storage media while silicon is nearly unique in its signal processing and micromechanical properties. We discuss how these two materials technologies, when integrated, provide unique devices and structures.

  5. Human Systems Integration Introduction

    NASA Video Gallery

    This lecture provides an overview of Human Systems Integration (HSI), its implementation cost and return on investment, HSI domains, how HSI fits into the NASA organization structure, HSI roles and...

  6. ALHAT Integration and Testing

    NASA Video Gallery

    Autonomous Landing and Hazard Avoidance Technology (ALHAT) project integration and testing takes place at NASA Langley Research Center. The ALHAT project is a multi-center initiative to enable vari...

  7. Complementary and Integrative Medicine

    MedlinePlus

    ... medical treatments that are not part of mainstream medicine. When you are using these types of care, it may be called complementary, integrative, or alternative medicine. Complementary medicine is used together with mainstream medical ...

  8. Integrating Forensic Science.

    ERIC Educational Resources Information Center

    Funkhouser, John; Deslich, Barbara J.

    2000-01-01

    Explains the implementation of forensic science in an integrated curriculum and discusses the advantages of this approach. Lists the forensic science course syllabi studied in three high schools. Discusses the unit on polymers in detail. (YDS)

  9. PEV Integration with Renewables (Presentation)

    SciTech Connect

    Markel, T.

    2014-06-18

    This presentation discusses current research at NREL on integrating plug-in electric vehicles with the grid and using renewable energy to charge the grid. The Electric Vehicle Grid Integration (EVGI) and Integrated Network Testbed for Energy Grid Research and Technology Experimentation (INTEGRATE) are addressing the opportunities and technical requirements for vehicle grid integration that will increase marketability and lead to greater petroleum reduction.

  10. Streamlining Payload Integration

    NASA Technical Reports Server (NTRS)

    Lufkin, Susan N.

    2010-01-01

    Payload integration onto space transport vehicles and the International Space Station (ISS) is a complex process. Yet, cargo transport is the sole reason for any space mission, be it for ferrying humans, science, or hardware. As the largest such effort in history, the ISS offers a wide variety of payload experience. However, for any payload to reach the Space Station under the current process, Payload Developers face a list of daunting tasks that go well beyond just designing the payload to the constraints of the transport vehicle and its stowage topology. Payload customers are required to prove their payload s functionality, structural integrity, and safe integration - including under less than nominal situations. They must also plan for or provide training, procedures, hardware labeling, ground support, and communications. In addition, they must deal with negotiating shared consumables, integrating software, obtaining video, and coordinating the return of data and hardware. All the while, they must meet export laws, launch schedules, budget limits, and the consensus of more than 12 panel and board reviews. Despite the cost and infrastructure overhead, payload proposals have increased. Just in the span from FY08 to FY09, the NASA Payload Space Station Support Office budget rose from $78M to $96M in attempt to manage the growing manifest, but the potential number of payloads still exceeds available Payload Integration Management manpower. The growth has also increased management difficulties due to the fact that payloads are more frequently added to a flight schedule late in the flow. The current standard ISS template for payload integration from concept to payload turn-over is 36 months, or 18 months if the payload already has a preliminary design. Customers are increasingly requiring a turn-around of 3 to 6-months to meet market needs. The following paper suggests options for streamlining the current payload integration process in order to meet customer schedule

  11. 2014 SRP Integration Transcript

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan

    2014-01-01

    HRP's mission is to reduce the risks to human health and performance during long-duration spaceflight. The HRP Integrated Research Plan (IRP) contains the research plans for the 32 risks that require research to characterize and mitigate. From its inception the "integrate" aspect of the IRP has denoted the integrated nature of risks to human health and performance. Even though each risk in the IRP has its own research plan and is tracked separately, the interrelated nature of health and performance requires that they be addressed in an integrative or holistic fashion so that the connectedness of physiological systems within the human body and the integrated response to spaceflight can be addressed. Common characteristics of the spaceflight environment include altered gravity, atmospheres, and light/dark cycles; space radiation; isolation; noise; and periods of high or low workload. Long-term exposure to this unique environment produces a suite of physiological effects such as stress; vision, neurocognitive, and anthropometric changes; circadian misalignment; fluid shifts; cardiovascular deconditioning; immune dysregulation; and altered nutritional requirements. Expanding cross-disciplinary integrative approaches that synthesize concepts or data from two or more disciplines would improve the identification and characterization risk factors, and enable the development of countermeasures relevant to multiple risks. Cross-disciplinary approaches might also help to illuminate problem areas that may arise when a countermeasure adversely impacts risks other than those which it was developed to mitigate, or to identify groupings of physiological changes that are likely to occur that may impact the overall risk posture. In 2014 HRP embarked on a pilot study that combined four SRPs (and 12 HRP risks) - Behavioral Health, Sensorimotor, Cardiovascular, and Bone/Muscle - specifically to discuss cross-disciplinary integration. The points outlined below were suggested to seed the

  12. AlN homoepitaxial growth on sublimation-AlN substrate by low-pressure HVPE

    NASA Astrophysics Data System (ADS)

    Nomura, Takuya; Okumura, Kenta; Miyake, Hideto; Hiramatsu, Kazumasa; Eryu, Osamu; Yamada, Yoichi

    2012-07-01

    Crack-free thick AlN layers with low impurity concentrations were grown on free-standing AlN substrates fabricated by a sublimation method. Cracks due to tensile stresses were generated in the overgrowth layer when using on-axis AlN (0 0 0 1) substrates, as indicated by Raman scattering spectroscopy. In contrast, cracks were not generated when using 5° off-angle AlN (0 0 0 1) substrates. High crystalline quality was indicated by X-ray rocking curve (XRC) analysis. The full width at half maximum (FWHM) values of the (0 0 0 2) and (1 0-1 0) diffractions were 277 and 306 arcsec, respectively. Secondary ion mass spectrometry (SIMS) measurements indicated that the Si and C impurity concentrations were reduced to half of those in the sublimation-grown AlN substrates.

  13. Al/sub 2/O/sub 3/ adherence on CoCrAl alloys

    SciTech Connect

    Kingsley, L.M.

    1980-04-01

    Adherence of protective oxides on NiCrAl and CoCrAl superalloys has been promoted by a dispersion of a highly oxygen reactive element or its oxide being produced within the protection system. Two aspects of this subject are investigated here: the use of Al/sub 2/O/sub 3/ as both the dispersion and protective oxide; and the production of an HfO/sub 2/ dispersion while simultaneously aluminizing the alloy. It was found that an Al/sub 2/O/sub 3/ dispersion will act to promote the adherence of an external scale of Al/sub 2/O/sub 3/ to a degree comparable to previously tested dispersions and an HfO/sub 2/ dispersion comparable to that produced by a Rhines pack treatment is produced during aluminization.

  14. Bonding characters of Al-containing bulk metallic glasses studied by 27Al NMR.

    PubMed

    Xi, X K; Sandor, M T; Wang, H J; Wang, J Q; Wang, W H; Wu, Y

    2011-03-23

    We report very small (27)Al metallic shifts in a series of Cu-Zr-Al bulk metallic glasses. This observation and the Korringa type of spin-lattice relaxation behavior suggest that s-character wavefunctions weakly participate in bonding and opens the possibility of enhanced covalency (pd hybridization) with increasing Al concentration, in good agreement with elastic constants and hardness measurements. Moreover, ab initio calculations show that this bonding character originates from the strong Al 3p band and Zr 4d band hybridization since their atomic energy levels are closer to each other while the Al 3s band is localized far below the Fermi level. This study might provide a chemical view for understanding flow and fracture mechanisms of these bulk glass-forming alloys.

  15. CVD Fiber Coatings for Al2O3/NiAl Composites

    NASA Technical Reports Server (NTRS)

    Boss, Daniel E.

    1995-01-01

    While sapphire-fiber-reinforced nickel aluminide (Al2O3/NiAl) composites are an attractive candidate for high-temperature structures, the significant difference in the coefficient of thermal expansion between the NiAl matrix and the sapphire fiber creates substantial residual stresses in the composite. This study seeks to produce two fiber-coating systems with the potential to reduce the residual stresses in the sapphire/NiAl composite system. Chemical vapor deposition (CVD) was used to produce both the compensating and compliant-fiber coatings for use in sapphire/NiAl composites. A special reactor was designed and built to produce the FGM and to handle the toxic nickel precursors. This process was successfully used to produce 500-foot lengths of fiber with coating thicknesses of approximately 3 microns, 5 microns, and 10 microns.

  16. Integrated spatial light modulator

    NASA Astrophysics Data System (ADS)

    Yu, Dong X.; Storti, George M.; Wrigley, Charles Y.

    1992-08-01

    We described here an integrated spatial light modulator (SLM) employing Quantex electron trapping (ET) materials. The light modulation is accomplished by emission of ET material, upon incident coherent infrared light, where a pattern is written to by previous visible light excitation. The ET based spatial light modulators offer unique advantages over other SLM devices, such as capability of converting incoherent input to coherent light output and of integrating the modulator, the photodetector, and the memory into a single, rugged unit.

  17. Integrated infrared array technology

    NASA Technical Reports Server (NTRS)

    Goebel, J. H.; Mccreight, C. R.

    1986-01-01

    An overview of integrated infrared (IR) array technology is presented. Although the array pixel formats are smaller, and the readout noise of IR arrays is larger, than the corresponding values achieved with optical charge-coupled-device silicon technology, substantial progress is being made in IR technology. Both existing IR arrays and those being developed are described. Examples of astronomical images are given which illustrate the potential of integrated IR arrays for scientific investigations.

  18. Integrated support structure

    NASA Technical Reports Server (NTRS)

    Bruneau, Stephen D.; Campbell, John T.; Struven, Christopher A.

    1990-01-01

    This Major Qualifying Project is part of the Advanced Space Design Program at WPI. The goal is to design a support structure for a NASA GetAway Special experimental canister. The payload integration, weight, volume, and structural integrity of the canister as specified by NASA guidelines were studied. The end result is a complete set of design drawings with interface drawings and data to specify the design and leave a base on which the next group can concentrate.

  19. The Integrated Medical Model

    NASA Technical Reports Server (NTRS)

    Kerstman, Eric; Minard, Charles; Saile, Lynn; Freiere deCarvalho, Mary; Myers, Jerry; Walton, Marlei; Butler, Douglas; Iyengar, Sriram; Johnson-Throop, Kathy; Baumann, David

    2010-01-01

    The goals of the Integrated Medical Model (IMM) are to develop an integrated, quantified, evidence-based decision support tool useful to crew health and mission planners and to help align science, technology, and operational activities intended to optimize crew health, safety, and mission success. Presentation slides address scope and approach, beneficiaries of IMM capabilities, history, risk components, conceptual models, development steps, and the evidence base. Space adaptation syndrome is used to demonstrate the model's capabilities.

  20. IDC Integrated Master Plan.

    SciTech Connect

    Clifford, David J.; Harris, James M.

    2014-12-01

    This is the IDC Re-Engineering Phase 2 project Integrated Master Plan (IMP). The IMP presents the major accomplishments planned over time to re-engineer the IDC system. The IMP and the associate Integrated Master Schedule (IMS) are used for planning, scheduling, executing, and tracking the project technical work efforts. REVISIONS Version Date Author/Team Revision Description Authorized by V1.0 12/2014 IDC Re- engineering Project Team Initial delivery M. Harris

  1. Astrophysical integrated research environment

    NASA Astrophysics Data System (ADS)

    Zhou, Jianfeng; Yang, Yang

    2007-08-01

    Astrophysical Integrated Research Environment (AIRE), aims to integrate astrophysical data, analysis software and astrophysical knowledge into an easy-to-use Internet based environment. Therefore, astrophysicists from different institutes can constitute virtual research groups which are favorable to study some complex multi-band astrophysical phenomena. The AIRE was put into use in Center for Astrophysics, Tsinghua university in 2003. Up to now, there are 219 advanced users in this environment. Several astrophysical researches base on AIRE have generated some important published results.

  2. Formation of gamma'-Ni3Al via the Peritectoid Reaction: gamma plus beta (+Al2O3) equals gamma'(+Al2O3)

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2008-01-01

    The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma'-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3) = gamma + beta (+ Al2O3), at 1640 plus or minus 1 K and a liquid composition of 24.8 plus or minus 0.2 at.%Al (at an unknown oxygen content). The {gamma + beta + Al2O3} phase field is stable over the temperature range 1633 - 1640 K, and gamma'-Ni3Al forms via the peritectiod, gamma + beta (+ Al2O3) = gamma'(+ Al2O3), at 1633 plus or minus 1 K. This behavior is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma'-Ni3Al phase field.

  3. Formation of gamma(sup prime)-Ni3Al via the Peritectoid Reaction: gamma + beta (+ Al2O3)=gamma(sup prime)(+ Al2O3)

    NASA Technical Reports Server (NTRS)

    Copeland, Evan

    2008-01-01

    The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8-32 at.%Al and temperature range T=1400-1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma(sup prime)-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3)=gamma + Beta(+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%al (at an unknown oxygen content). The {gamma + Beta (+Al2O3} phase field is stable over the temperature range 1633-1640 K, and gamma(sup prime)-Ni3Al forms via the peritectoid, gamma + Beta (+ Al2O3)=gamma(sup prime) (+ Al2O3), at 1633 +/- 1 K. This behavior is consistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(sup prime)-Ni2Al phase field.

  4. Effect of stress on the Al composition evolution in AlGaN grown using metal organic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    He, Chenguang; Qin, Zhixin; Xu, Fujun; Zhang, Lisheng; Wang, Jiaming; Hou, Mengjun; Zhang, Shan; Wang, Xinqiang; Ge, Weikun; Shen, Bo

    2016-05-01

    Two series of AlGaN samples with different stresses were designed to investigate the effect of stress on the Al composition. X-ray diffraction reciprocal space mapping (XRD RSM) demonstrated that the AlGaN epilayers with different stresses have large Al composition differences despite the same growth conditions. The largest Al composition difference reached up to 21.3%, which was also confirmed using secondary ion mass spectroscopy (SIMS). This result is attributed to a large stress discrepancy in the AlGaN epilayers. Finally, the dependences of the solid-phase Al composition on the gas-phase Al composition under different stresses were systematically analyzed.

  5. Current Research at the Endeavour Ridge 2000 Integrated Studies Site

    NASA Astrophysics Data System (ADS)

    Butterfield, D. A.; Kelley, D. S.; Ridge 2000 Community, R.

    2004-12-01

    Integrated geophysical, geological, chemical, and biological studies are being conducted on the Endeavour segment with primary support from NSF, the W.M. Keck Foundation, and NSERC (Canada). The research includes a seismic network, physical and chemical sensors, high-precision mapping and time-series sampling. Several research expeditions have taken place at the Endeavour ISS in the past year. In June 2003, an NSF-sponsored cruise with R.V. al T.G.Thompson/ROV al Jason2 installed microbial incubators in drill-holes in the sides of active sulfide chimneys and sampled rocks, fluids, and microbes in the Mothra and Main Endeavour Field (MEF). In July 2003, with al Thompson/Jason2, an NSF-LEXEN project at Baby Bare on Endeavour east flank conducted sampling through seafloor-penetrating probes, plus time-series sampling of fluids, microbes, and rocks at the MEF. In September 2003, with al Thompson/ROV al ROPOS, the Keck Proto-Neptune project installed a seismic network consisting of 1 broadband and 7 short-period seismometers, installation of chemical/physical sensors and time-series samplers for chemistry and microbiology in the MEF and Clam Bed sites, collection of rocks, fluids, animals, and microbes. In May/June 2004, an NSF-sponsored al Atlantis/Alvin cruise recovered sulfide incubators installed in 2003, redeployed a sulfide incubator, mapped MEF and Mothra vent fields with high-resolution Imagenix sonar, sampled fluids from MEF, Mothra, and Clam Bed, recovered year-long time-series fluid and microbial samplers from MEF and Clam Bed, recovered and installed hot vent temperature-resistivity monitors, cleaned up the MEF and deployed new markers at major sulfide structures. In August 2004, there were two MBARI/Keck-sponsored cruises with R.V. al Western Flyer/ROV al Tiburon. The first cruise completed the seismic network with addition of two more broadband seismometers and serviced all 7 short-period seismometers. al Tiburon then performed microbial and chemical

  6. Effect of sintering temperature and time intervals on morphological and hardness behaviour of Al-20 vol% Sn matrix composites

    NASA Astrophysics Data System (ADS)

    Badarulzaman, N. A.; Karim, S. R.; Lajis, M. A.

    2015-05-01

    Aluminium (Al) alloys are widely used in various industries, such as automotive and aerospace. The production processes in these sectors create large amount of Al residues. In this paper, a new method of recycling Al chip is presented. Metal matrix composite (MMCs) of Al-20 vol% Sn was prepared by using solid state direct conversion method of recycled Al 6061 alloy. Constant pressure (10 ton) was used to implement the cold forging process. The differences of sintering temperature (200 °C, 250 °C, 300 °C and 350 °C) and time intervals (1h, 2h, 3h, 4h and 5h) were studied to obtain the optimum hardness, strength and surface integrity of Al-20 vol% Sn. The results showed that, hardness and strength of Al-20 vol% Sn was decreased by additional temperature and increase with time interval of sintering. Sintering temperature at 350 °C produces better morphology structure of Al-Sn composites.

  7. Imagery Integration Team

    NASA Technical Reports Server (NTRS)

    Calhoun, Tracy; Melendrez, Dave

    2014-01-01

    The Human Exploration Science Office (KX) provides leadership for NASA's Imagery Integration (Integration 2) Team, an affiliation of experts in the use of engineering-class imagery intended to monitor the performance of launch vehicles and crewed spacecraft in flight. Typical engineering imagery assessments include studying and characterizing the liftoff and ascent debris environments; launch vehicle and propulsion element performance; in-flight activities; and entry, landing, and recovery operations. Integration 2 support has been provided not only for U.S. Government spaceflight (e.g., Space Shuttle, Ares I-X) but also for commercial launch providers, such as Space Exploration Technologies Corporation (SpaceX) and Orbital Sciences Corporation, servicing the International Space Station. The NASA Integration 2 Team is composed of imagery integration specialists from JSC, the Marshall Space Flight Center (MSFC), and the Kennedy Space Center (KSC), who have access to a vast pool of experience and capabilities related to program integration, deployment and management of imagery assets, imagery data management, and photogrammetric analysis. The Integration 2 team is currently providing integration services to commercial demonstration flights, Exploration Flight Test-1 (EFT-1), and the Space Launch System (SLS)-based Exploration Missions (EM)-1 and EM-2. EM-2 will be the first attempt to fly a piloted mission with the Orion spacecraft. The Integration 2 Team provides the customer (both commercial and Government) with access to a wide array of imagery options - ground-based, airborne, seaborne, or vehicle-based - that are available through the Government and commercial vendors. The team guides the customer in assembling the appropriate complement of imagery acquisition assets at the customer's facilities, minimizing costs associated with market research and the risk of purchasing inadequate assets. The NASA Integration 2 capability simplifies the process of securing one

  8. Gardner's deformations as generators of new integrable systems

    NASA Astrophysics Data System (ADS)

    Kiselev, Arthemy V.; Krutov, Andrey O.

    2014-03-01

    We re-address the problem of construction of new infinite-dimensional completely integrable systems on the basis of known ones, and we reveal a working mechanism for such transitions. By splitting the problem's solution in two steps, we explain how the classical technique of Gardner's deformations facilitates - in a regular way - making the first, nontrivial move, in the course of which the drafts of new systems are created (often, of hydrodynamic type). The other step then amounts to higher differential order extensions of symbols in the intermediate hierarchies (e. g., by using the techniques of Dubrovin et al. [1, 2] and Ferapontov et al. [3, 4]).

  9. Microstructure of Ni-Al powder and Ni-Al composite coatings prepared by twin-wire arc spraying

    NASA Astrophysics Data System (ADS)

    Wang, Ji-xiao; Wang, Gui-xian; Liu, Jing-shun; Zhang, Lun-yong; Wang, Wei; Li, Ze; Wang, Qi-xiang; Sun, Jian-fei

    2016-07-01

    Ni-Al powder and Ni-Al composite coatings were fabricated by twin-wire arc spraying (TWAS). The microstructures of Ni-5wt%Al powder and Ni-20wt%Al powder were characterized by scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that the obtained particle size ranged from 5 to 50 μm. The morphology of the Ni-Al powder showed that molten particles were composed of Ni solid solution, NiAl, Ni3Al, Al2O3, and NiO. The Ni-Al phase and a small amount of Al2O3 particles changed the composition of the coating. The microstructures of the twin-wire-arc-sprayed Ni-Al composite coatings were characterized by SEM, EDS, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results showed that the main phase of the Ni-5wt%Al coating consisted of Ni solid solution and NiAl in addition to a small amount of Al2O3. The main phase of the Ni-20wt%Al coating mainly consisted of Ni solid solution, NiAl, and Ni3Al in addition to a small amount of Al and Al2O3, and NiAl and Ni3Al intermetallic compounds effectively further improved the final wear property of the coatings. TEM analysis indicated that fine spherical NiAl3 precipitates and a Ni-Al-O amorphous phase formed in the matrix of the Ni solid solution in the original state.

  10. Ternary Dy-Er-Al magnetic refrigerants

    DOEpatents

    Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

  11. Bierman {ital et al.}Reply:

    SciTech Connect

    Bierman, J.D.; Chan, P.; Liang, J.F.; Kelly, M.P.; Sonzogni, A.A.; Vandenbosch, R.

    1997-05-01

    reply to the Comment by C.H.Dasso et al., Phys. Rev. Lett. 78,XXX(1997). A Reply to the Comment by C.H. Dasso and J. Fern{acute a}ndez-Niello. {copyright} {ital 1997} {ital The American Physical Society}

  12. Hughes et al.: Science or Promotion?

    ERIC Educational Resources Information Center

    Loman, L. Anthony; Siegel, Gary L.

    2013-01-01

    The Hughes et al. paper is critiqued generally and in specific areas. The weak nature of the authors' empirical work is discussed along with their enigmatic writing and vague and incorrect use of references, and their simultaneous use of sweeping statements of opinion and narrow analytical focus. This review examines the authors' errors…

  13. Kinematics of Disease Progression in Bulbar ALS

    ERIC Educational Resources Information Center

    Yunusova, Yana; Green, Jordan R.; Lindstrom, Mary J.; Ball, Laura J.; Pattee, Gary L.; Zinman, Lorne

    2010-01-01

    The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech…

  14. Al/Cl2 molten salt battery

    NASA Technical Reports Server (NTRS)

    Giner, J.

    1972-01-01

    Molten salt battery has been developed with theoretical energy density of 5.2 j/kg (650 W-h/lb). Battery, which operates at 150 C, can be used in primary mode or as rechargeable battery. Battery has aluminum anode and chlorine cathode. Electrolyte is mixture of AlCl3, NaCl, and some alkali metal halide such as KCl.

  15. Cryptanalysis on Cheng et al. protocol

    NASA Astrophysics Data System (ADS)

    Thakur, Tejeshwari

    2016-06-01

    Deployment of new node in any wireless sensor network is a sensitive task. This is the reason why, an Access Control Protocol is required in WSN. In this paper, we demonstrate that Access Control Protocol proposed by Cheng et al.[1] for Wireless Sensor Network is insecure. The reason is that this protocol fails to resist the active attack.

  16. Ternary Dy-Er-Al magnetic refrigerants

    DOEpatents

    Gschneidner, K.A. Jr.; Takeya, Hiroyuki

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})Al{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.

  17. Synopsis of "Reply to Levitas et al."

    ERIC Educational Resources Information Center

    O'Brien, John

    1994-01-01

    This synopsis of a reply by Wolf Wolfensberger to a critique by Levitas et al. (EC 609 743) notes extensive documentation supporting Wolfensberger's assertion that prescription psychoactive drugs are health destroying and life destroying. Issues of truth and of epistemology are identified as they apply to the treatment of these socially devalued…

  18. 76 FR 62481 - Incapital LLC, et al.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Incapital LLC, et al.; Notice of Application September 30, 2011. AGENCY: Securities and Exchange Commission (``Commission''). ACTION: Notice of application for an order under section 12(d)(1)(J) of...

  19. U-ALS: A Ubiquitous Learning Environment

    ERIC Educational Resources Information Center

    Piovesan, Sandra Dutra; Passerino, Liliana Maria; Medina, Roseclea Duarte

    2012-01-01

    The diffusion of the use of the learning virtual environments presents a great potential for the development of an application which meet the necessities in the education area. In view of the importance of a more dynamic application and that can adapt itself continuously to the students' necessities, the "U-ALS" (Ubiquitous Adapted Learning…

  20. UCSC Data Integrator and Variant Annotation Integrator

    PubMed Central

    Hinrichs, Angie S.; Raney, Brian J.; Speir, Matthew L.; Rhead, Brooke; Casper, Jonathan; Karolchik, Donna; Kuhn, Robert M.; Rosenbloom, Kate R.; Zweig, Ann S.; Haussler, David; Kent, W. James

    2016-01-01

    Summary: Two new tools on the UCSC Genome Browser web site provide improved ways of combining information from multiple datasets, optionally including the user's own custom track data and/or data from track hubs. The Data Integrator combines columns from multiple data tracks, showing all items from the first track along with overlapping items from the other tracks. The Variant Annotation Integrator is tailored to adding functional annotations to variant calls; it offers a more restricted set of underlying data tracks but adds predictions of each variant's consequences for any overlapping or nearby gene transcript. When available, it optionally adds additional annotations including effect prediction scores from dbNSFP for missense mutations, ENCODE regulatory summary tracks and conservation scores. Availability and implementation: The web tools are freely available at http://genome.ucsc.edu/ and the underlying database is available for download at http://hgdownload.cse.ucsc.edu/. The software (written in C and Javascript) is available from https://genome-store.ucsc.edu/ and is freely available for academic and non-profit usage; commercial users must obtain a license. Contact: angie@soe.ucsc.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26740527

  1. Differential absorption lidar measurements of atmospheric water vapor using a pseudonoise code modulated AlGaAs laser. Thesis

    NASA Technical Reports Server (NTRS)

    Rall, Jonathan A. R.

    1994-01-01

    Lidar measurements using pseudonoise code modulated AlGaAs lasers are reported. Horizontal path lidar measurements were made at night to terrestrial targets at ranges of 5 and 13 km with 35 mW of average power and integration times of one second. Cloud and aerosol lidar measurements were made to thin cirrus clouds at 13 km altitude with Rayleigh (molecular) backscatter evident up to 9 km. Average transmitter power was 35 mW and measurement integration time was 20 minutes. An AlGaAs laser was used to characterize spectral properties of water vapor absorption lines at 811.617, 816.024, and 815.769 nm in a multipass absorption cell using derivative spectroscopy techniques. Frequency locking of an AlGaAs laser to a water vapor absorption line was achieved with a laser center frequency stability measured to better than one-fifth of the water vapor Doppler linewidth over several minutes. Differential absorption lidar measurements of atmospheric water vapor were made in both integrated path and range-resolved modes using an externally modulated AlGaAs laser. Mean water vapor number density was estimated from both integrated path and range-resolved DIAL measurements and agreed with measured humidity values to within 6.5 percent and 20 percent, respectively. Error sources were identified and their effects on estimates of water vapor number density calculated.

  2. Aluminum matrix texture in Al-Al3Ti functionally graded materials analyzed by electron back-scattering diffraction

    NASA Astrophysics Data System (ADS)

    Watanabe, Yoshimi; Sequeira, Paulo D.; Sato, Hisashi; Inamura, Tomonari; Hosoda, Hideki

    2016-01-01

    Al matrix functionally graded materials (FGMs) with oriented Al3Ti platelets were fabricated by a centrifugal solid-particle method. The applied centrifugal forces were 30, 60, and 120G (units of gravity). The orientation and volume fraction gradients of the Al3Ti platelets within the samples were measured. Since a good lattice correspondence was reported for the close-packed directions and the close-packed planes between Al and Al3Ti, the Al matrix in the Al-Al3Ti FGMs fabricated by the centrifugal solid-particle method should have some texture. Al matrix texture was, therefore, analyzed by electron back-scattering diffraction (EBSD). Analysis of the resulting pole figures indicates a preferred orientation along the (200) plane for the Al matrix crystals. Furthermore, increasing the applied centrifugal force enhances the orientation effect. A correlation appears to exist between platelet orientation and the preferred texture of the Al matrix.

  3. Spectroscopic analysis of the open 3d subshell transition metal aluminides: AlV, AlCr, and AlCo

    NASA Astrophysics Data System (ADS)

    Behm, Jane M.; Brugh, Dale J.; Morse, Michael D.

    1994-10-01

    Three open 3d subshell transition metal aluminides, AlV, AlCr, and AlCo, have been investigated by resonant two-photon ionization spectroscopy to elucidate the chemical bonding in these diatomic molecules. The open nature of the 3d subshell results in a vast number of excited electronic states in these species, allowing bond strengths to be measured by the observation of abrupt predissociation thresholds in a congested optical spectrum, giving D00(AlV)=1.489±0.010 eV, D00(AlCr)=2.272±0.009 eV, and D00(AlCo)=1.844±0.002 eV. At lower excitation energies the presence of discrete transitions has permitted determinations of the ground state symmetries and bond lengths of AlV and AlCo through rotationally resolved studies, giving r0` (AlV, Ω`=0)=2.620±0.004 Å and r0` (AlCo, Ω`=3)=2.3833±0.0005 Å. Ionization energies were also measured for all three species, yielding IE(AlV)=6.01±0.10 eV, IE(AlCr)=5.96±0.04 eV, and IE(AlCo)=6.99±0.17 eV. A discussion of these results is presented in the context of previous work on AlCu, AlNi, AlCa, and AlZn.

  4. Effect of thermal cycling on interface bonding requirements in Al2O3 fiber-reinforced superalloy composites

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.

    1993-01-01

    CTE (coefficient of thermal expansion) mismatch-induced stresses as they affect the fiber-matrix bond integrity of Al2O3 fiber-reinforced superalloy composites are examined. Of the three individual stress components, only the radial stress directly affects the integrity of the fiber-matrix interface. It is noted that a compressive radial stress leads to a clamping action on the fiber and is therefore beneficial to the integrity of the fiber-matrix bond. A radial tensile stress, on the other hand, can cause debonding of the fiber from the matrix for a weak fiber-matrix bond.

  5. Thermoelectric Powers of Cells With NaF-AlF3-Al2O3 Melts

    NASA Astrophysics Data System (ADS)

    Flem, Belinda E.; Xu, Qian; Kjelstrup, Signe; Sterten, Åsmund

    2001-07-01

    A thermodynamic description of the Peltier heat at the aluminum and the oxygen electrode in the system NaF-AlF3-Al2O3 is given. The thermoelectric power in melts with molar ratios n NaF/n AlF3 from 3.0 to 1.0, saturated with alumina are measured. Seebeck coefficients for molten fluoride electrolytes saturated with alumina, electrolytes that are relevant for aluminum electrowinning electrolysis cells, are reported. The results allow determinations of Peltier heats of aluminum, oxygen and carbon electrodes in NaF-AlF3 electrolytes saturated with alumina. For molar ratios of n NaF/n AlF3 between 2.6 and 1.2, there is a Peltier heating of the aluminum cathode. This heating is in the same order of magnitude as the electrolyte Joule heat, when the current density is 0.7 A cm-2. For molar ratio n NaF/n AlF3 equal to 1.0 the Peltier effect at the aluminum electrode approaches zero. From theoretical considerations we expect a drop also for molar ratio 3.0. For the anode we report a Peltier cooling that is larger than the heat produced by the anodic overvoltage, in melts with NaF/AlF3 molar ratio between 2.6 and 1.2 saturated with alumina.

  6. A novel Al matrix composite reinforced by nano-AlNp network

    PubMed Central

    Ma, X.; Zhao, Y. F.; Tian, W. J.; Qian, Z.; Chen, H. W.; Wu, Y. Y.; Liu, X. F.

    2016-01-01

    In pursuit of lightweighting of automobiles and low emission of transportation, the efforts to develop high-strength, heat-resistant and fatigue-resistant Al alloys and/or composites have been ongoing. Here we report a novel Al matrix composite with ultrahigh strength reinforced by a three dimensional network of nano-AlN particles for the first time. The in-situ synthesized AlN particles are connected by twinning bonding chains and built up a three dimensional network strengthening Al matrix enormously like the skeleton to human body. The composite containing 16.4wt.% AlN particles shows excellent properties: the ultimate tensile strengths can be up to 518MPa at room temperature and 190MPa at 350 °C. This peculiar performance results from the novel spatial distribution of nano-scale AlN particles. Our findings in this work would help to develop a potential candidate for high-performance heat resistance light-metal based materials. PMID:27721417

  7. Effect of speciation transformation on the coagulation behavior of Al(13) and Al(13) aggregates.

    PubMed

    Wu, Xiaohong; Ye, Changqing; Wang, Dongsheng; Ge, Xiaopeng; Tang, Hongxiao

    2009-01-01

    Flocculation of kaolin suspension with aluminium fractal polycations was investigated as a function of aluminium concentration and pH. Aluminium flocculants included Al(13) and Al(13) aggregates with OH/Al ratio of 2.6 and 2.8, respectively. The flocculation kinetics and floc size distribution were monitored by light scattering. The characterization of flocculants showed that the tridecatmer Al(13) and bridged [Al(13)](n) with out-sphere structure were the dominant species for all flocculants in a wide pH range. The coagulation results indicated that the pre and in situ-formed [Al(13)](n) play a key role in removing particles. With the increasing concentration of [Al(13)](n), coagulation mechanisms were transformed from charge-neutralization, electro-patch coagulation to bridge-aggregation. Moreover, sweep-flocculation was involved at higher dosage besides other three mechanisms when amorphous aluminium oxides formed. Hence, chemical interaction between particles and flocculants evolved from surface adsorption to surface precipitation for aluminium polycations by virtue of species transformation. PMID:19237777

  8. A novel Al matrix composite reinforced by nano-AlNp network

    NASA Astrophysics Data System (ADS)

    Ma, X.; Zhao, Y. F.; Tian, W. J.; Qian, Z.; Chen, H. W.; Wu, Y. Y.; Liu, X. F.

    2016-10-01

    In pursuit of lightweighting of automobiles and low emission of transportation, the efforts to develop high-strength, heat-resistant and fatigue-resistant Al alloys and/or composites have been ongoing. Here we report a novel Al matrix composite with ultrahigh strength reinforced by a three dimensional network of nano-AlN particles for the first time. The in-situ synthesized AlN particles are connected by twinning bonding chains and built up a three dimensional network strengthening Al matrix enormously like the skeleton to human body. The composite containing 16.4wt.% AlN particles shows excellent properties: the ultimate tensile strengths can be up to 518MPa at room temperature and 190MPa at 350 °C. This peculiar performance results from the novel spatial distribution of nano-scale AlN particles. Our findings in this work would help to develop a potential candidate for high-performance heat resistance light-metal based materials.

  9. Some TEM observations of Al2O3 scales formed on NiCrAl alloys

    NASA Technical Reports Server (NTRS)

    Smialek, J.; Gibala, R.

    1979-01-01

    The microstructural development of Al2O3 scales on NiCrAl alloys has been examined by transmission electron microscopy. Voids were observed within grains in scales formed on a pure NiCrAl alloy. Both voids and oxide grains grew measurably with oxidation time at 1100 C. The size and amount of porosity decreased towards the oxide-metal growth interface. The voids resulted from an excess number of oxygen vacancies near the oxidemetal interface. Short-circuit diffusion paths were discussed in reference to current growth stress models for oxide scales. Transient oxidation of pure, Y-doped, and Zr-doped NiCrAl was also examined. Oriented alpha-(Al, Cr)2O3 and Ni(Al, Cr)2O4 scales often coexisted in layered structures on all three alloys. Close-packed oxygen planes and directions in the corundum and spinel layers were parallel. The close relationship between oxide layers provided a gradual transition from initial transient scales to steady state Al2O3 growth.

  10. When Validity Testing Lacks Validity: Comment on Levine et al.

    ERIC Educational Resources Information Center

    Kim, Min-Sun; Raja, Narayan S.

    2003-01-01

    Addresses each of the three main areas of Levine et al.'s (see this issue, CS 764 297) validity testing: mean differences in self-construals between Asians and Westerners and within individuals; priming experiments; and factor analysis of self-construal scales. Suggests that Levine et al.'s conclusions on crucial aspects of validity are untenable.…

  11. An epidemiological study of cutaneous leishmaniasis in Al-jabal Al-gharbi, Libya.

    PubMed

    Abdellatif, Manal Z M; El-Mabrouk, Khamis; Ewis, Ashraf A

    2013-02-01

    Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed.

  12. An Epidemiological Study of Cutaneous Leishmaniasis in Al-Jabal Al-Gharbi, Libya

    PubMed Central

    Abdellatif, Manal Z. M.; El-Mabrouk, Khamis

    2013-01-01

    Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed. PMID:23467624

  13. Epitaxial growth of higher transition-temperature VO2 films on AlN/Si

    NASA Astrophysics Data System (ADS)

    Slusar, Tetiana; Cho, Jin-Cheol; Kim, Bong-Jun; Yun, Sun Jin; Kim, Hyun-Tak

    2016-02-01

    We report the epitaxial growth and the mechanism of a higher temperature insulator-to-metal-transition (IMT) of vanadium dioxide (VO2) thin films synthesized on aluminum nitride (AlN)/Si (111) substrates by a pulsed-laser-deposition method; the IMT temperature is TIMT ≈ 350 K. X-ray diffractometer and high resolution transmission electron microscope data show that the epitaxial relationship of VO2 and AlN is VO2 (010) ‖ AlN (0001) with VO2 [101] ‖ AlN [ 2 1 ¯ 1 ¯ 0 ] zone axes, which results in a substrate-induced tensile strain along the in-plane a and c axes of the insulating monoclinic VO2. This strain stabilizes the insulating phase of VO2 and raises TIMT for 10 K higher than TIMT single crystal ≈ 340 K in a bulk VO2 single crystal. Near TIMT, a resistance change of about four orders is observed in a thick film of ˜130 nm. The VO2/AlN/Si heterostructures are promising for the development of integrated IMT-Si technology, including thermal switchers, transistors, and other applications.

  14. Solidification processing of intermetallic Nb-Al alloys

    NASA Technical Reports Server (NTRS)

    Smith, Preston P.; Oliver, Ben F.; Noebe, Ronald D.

    1992-01-01

    Several Nb-Al alloys, including single-phase NbAl3 and the eutectic of Nb2Al and NbAl3, were prepared either by nonconsumable arc melting in Ar or by zone processing in He following initial induction melting and rod casting, and the effect of the solidification route on the microstructure and room-temperature mechanical properties of these alloys was investigated. Automated control procedures and melt conditions for directional solidification of NbAl3 and the Nb2Al/Nb3Al eutectic were developed; high purity and stoichiometry were obtained. The effects of ternary additions of Ti and Ni are described.

  15. Revisiting Deng et al.'s Multiparty Quantum Secret Sharing Protocol

    NASA Astrophysics Data System (ADS)

    Hwang, Tzonelih; Hwang, Cheng-Chieh; Yang, Chun-Wei; Li, Chuan-Ming

    2011-09-01

    The multiparty quantum secret sharing protocol [Deng et al. in Chin. Phys. Lett. 23: 1084-1087, 2006] is revisited in this study. It is found that the performance of Deng et al.'s protocol can be much improved by using the techniques of block-transmission and decoy single photons. As a result, the qubit efficiency is improved 2.4 times and only one classical communication, a public discussion, and two quantum communications between each agent and the secret holder are needed rather than n classical communications, n public discussions, and 3n/2 quantum communications required in the original scheme.

  16. Ferromagnetic ordering in NpAl2: Magnetic susceptibility and 27Al nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Martel, L.; Griveau, J.-C.; Eloirdi, R.; Selfslag, C.; Colineau, E.; Caciuffo, R.

    2015-08-01

    We report on the magnetic properties of the neptunium based ferromagnetic compound NpAl2. We used magnetization measurements and 27Al NMR spectroscopy to access magnetic features related to the paramagnetic and ordered states (TC=56 K). While very precise DC SQUID magnetization measurements confirm ferromagnetic ordering, they show a relatively small hysteresis loop at 5 K reduced with a coercive field HCo~3000 Oe. The variable offset cumulative spectra (VOCS) acquired in the paramagnetic state show a high sensitivity of the 27Al nuclei spectral parameters (Knight shifts and line broadening) to the ferromagnetic ordering, even at room temperature.

  17. Al-based metal matrix composites reinforced with nanocrystalline Al-Ti-Ni particles

    NASA Astrophysics Data System (ADS)

    Scudino, S.; Ali, F.; Surreddi, K. B.; Prashanth, K. G.; Sakaliyska, M.; Eckert, J.

    2010-07-01

    Al-based metal matrix composites containing different volume fractions of nanocrystalline Al70Ti20Ni10 reinforcing particles have been produced by powder metallurgy and the effect of the volume fraction of reinforcement on the mechanical properties of the composites has been studied. Room temperature compression tests reveal a considerable improvement of the mechanical properties as compared to pure Aluminum. The compressive strength increases from 155 MPa for pure Al to about 200 and 240 MPa for the samples with 20 and 40 vol.% of reinforcement, respectively, while retaining appreciable plastic deformation with a fracture strain ranging between 43 and 28 %.

  18. Integrated work management system.

    SciTech Connect

    Williams, Edward J., Jr.; Henry, Karen Lynne

    2010-06-01

    Sandia National Laboratories develops technologies to: (1) sustain, modernize, and protect our nuclear arsenal (2) Prevent the spread of weapons of mass destruction; (3) Provide new capabilities to our armed forces; (4) Protect our national infrastructure; (5) Ensure the stability of our nation's energy and water supplies; and (6) Defend our nation against terrorist threats. We identified the need for a single overarching Integrated Workplace Management System (IWMS) that would enable us to focus on customer missions and improve FMOC processes. Our team selected highly configurable commercial-off-the-shelf (COTS) software with out-of-the-box workflow processes that integrate strategic planning, project management, facility assessments, and space management, and can interface with existing systems, such as Oracle, PeopleSoft, Maximo, Bentley, and FileNet. We selected the Integrated Workplace Management System (IWMS) from Tririga, Inc. Facility Management System (FMS) Benefits are: (1) Create a single reliable source for facility data; (2) Improve transparency with oversight organizations; (3) Streamline FMOC business processes with a single, integrated facility-management tool; (4) Give customers simple tools and real-time information; (5) Reduce indirect costs; (6) Replace approximately 30 FMOC systems and 60 homegrown tools (such as Microsoft Access databases); and (7) Integrate with FIMS.

  19. HIV DNA Integration

    PubMed Central

    Craigie, Robert; Bushman, Frederic D.

    2012-01-01

    Retroviruses are distinguished from other viruses by two characteristic steps in the viral replication cycle. The first is reverse transcription, which results in the production of a double-stranded DNA copy of the viral RNA genome, and the second is integration, which results in covalent attachment of the DNA copy to host cell DNA. The initial catalytic steps of the integration reaction are performed by the virus-encoded integrase (IN) protein. The chemistry of the IN-mediated DNA breaking and joining steps is well worked out, and structures of IN-DNA complexes have now clarified how the overall complex assembles. Methods developed during these studies were adapted for identification of IN inhibitors, which received FDA approval for use in patients in 2007. At the chromosomal level, HIV integration is strongly favored in active transcription units, which may promote efficient viral gene expression after integration. HIV IN binds to the cellular factor LEDGF/p75, which promotes efficient infection and tethers IN to favored target sites. The HIV integration machinery must also interact with many additional host factors during infection, including nuclear trafficking and pore proteins during nuclear entry, histones during initial target capture, and DNA repair proteins during completion of the DNA joining steps. Models for some of the molecular mechanisms involved have been proposed, but important details remain to be clarified. PMID:22762018

  20. Integrated Budget Office Toolbox

    NASA Technical Reports Server (NTRS)

    Rushing, Douglas A.; Blakeley, Chris; Chapman, Gerry; Robertson, Bill; Horton, Allison; Besser, Thomas; McCarthy, Debbie

    2010-01-01

    The Integrated Budget Office Toolbox (IBOT) combines budgeting, resource allocation, organizational funding, and reporting features in an automated, integrated tool that provides data from a single source for Johnson Space Center (JSC) personnel. Using a common interface, concurrent users can utilize the data without compromising its integrity. IBOT tracks planning changes and updates throughout the year using both phasing and POP-related (program-operating-plan-related) budget information for the current year, and up to six years out. Separating lump-sum funds received from HQ (Headquarters) into separate labor, travel, procurement, Center G&A (general & administrative), and servicepool categories, IBOT creates a script that significantly reduces manual input time. IBOT also manages the movement of travel and procurement funds down to the organizational level and, using its integrated funds management feature, helps better track funding at lower levels. Third-party software is used to create integrated reports in IBOT that can be generated for plans, actuals, funds received, and other combinations of data that are currently maintained in the centralized format. Based on Microsoft SQL, IBOT incorporates generic budget processes, is transportable, and is economical to deploy and support.

  1. Capacitance-voltage characteristics of (Al/Ti)/Al{sub 2}O{sub 3}/n-GaN MIS structures

    SciTech Connect

    Ivanov, P. A. Potapov, A. S.; Nikolaev, A. E.; Lundin, V. V.; Sakharov, A. V.; Tsatsulnikov, A. F.; Afanas’ev, A. V.; Romanov, A. A.; Osachev, E. V.

    2015-08-15

    The capacitance-voltage characteristics of (Al/Ti)/Al{sub 2}O{sub 3}/n-GaN metal—insulator-semiconductor (MIS) structures are measured and analyzed. n-Type GaN films are grown on sapphire (0001) substrates by the metal-organic chemical vapor deposition method. An aluminum-oxide layer with a thickness of 60 nm is deposited onto the surface of GaN by the method of atomic-layer deposition from the gas phase. Metallic contacts are deposited by the electron-beam evaporation of titanium and aluminum in vacuum. According to the measurement results, the breakdown-field strength of the oxide, its dielectric constant, and the integrated electron density of states at the oxide-semiconductor interface are 5 × 10{sup 6} V/cm, 7.5, and 3 × 10{sup 12} cm{sup −2}, respectively.

  2. Super Smooth Modification of Al2O3 Ceramic Substrate by High Temperature Glaze of CaO-Al2O3-SiO2 System

    NASA Astrophysics Data System (ADS)

    Zhang, Jihua; Zhen, Shanxue; Yang, Lijun; Lou, Feizhi; Chen, Hongwei; Yang, Chuanren

    2011-01-01

    The rough surface of ceramic substrate is an obstacle for the scale down of line-width for thin film passive integrated devices (PID). In this paper, a modification method for Al2O3 ceramic substrate with super smooth in surface was proposed. Coating a layer of CaO-Al2O3-SiO2 (CAS) glass was performed to flat the rough surface of alumina substrate by sol-gel method. It was found that addition of 0.06% V2O5 can inhibit the recrystallization of the glaze. The root-mean-square (RMS) roughness of the glazed substrates reached a surprising flatness as small as 0.5 nm, and its melting temperature is higher than 1300 °C. This substrate with super flatness and high temperature endurance may be promising for high performance thin film devices.

  3. Transparent capacitors based on nanolaminate Al{sub 2}O{sub 3}/TiO{sub 2}/Al{sub 2}O{sub 3} with H{sub 2}O and O{sub 3} as oxidizers

    SciTech Connect

    Zhang, G. Z.; Wu, H. Chen, C.; Wang, T.; Yue, J.; Liu, C.; Wang, P. Y.; Mai, L. Q.

    2014-04-21

    Transparent capacitors with nanolaminate Al{sub 2}O{sub 3}/TiO{sub 2}/Al{sub 2}O{sub 3} (ATA) hybrid dielectrics have been prepared on quartz glass by atomic layer deposition. The maximal capacitance density of 14 fF/μm{sup 2} at 1 kHz was obtained. Moreover, an ultralow leakage current density of 2.1 × 10{sup −9} A/cm{sup 2} at 1 V was realized by using O{sub 3} as the oxidizer. Fowler-Nordheim tunneling is the main mechanism of the leakage current at high fields, while several conduction mechanisms coexist at low fields. The AlZnO/ATA/AlZnO transparent capacitors exhibit an average optical transmittance of more than 80% in the visible range, which serve as good candidates for integration in transparent circuits.

  4. Nanostructure surface patterning of GaN thin films and application to AlGaN/AlN multiple quantum wells: A way towards light extraction efficiency enhancement of III-nitride based light emitting diodes

    SciTech Connect

    Guo, Wei Kirste, Ronny; Bryan, Zachary; Bryan, Isaac; Collazo, Ramón; Sitar, Zlatko; Gerhold, Michael

    2015-03-21

    Enhanced light extraction efficiency was demonstrated on nanostructure patterned GaN and AlGaN/AlN Multiple-Quantum-Well (MQW) structures using mass production techniques including natural lithography and interference lithography with feature size as small as 100 nm. Periodic nanostructures showed higher light extraction efficiency and modified emission profile compared to non-periodic structures based on integral reflection and angular-resolved transmission measurement. Light extraction mechanism of macroscopic and microscopic nanopatterning is discussed, and the advantage of using periodic nanostructure patterning is provided. An enhanced photoluminescence emission intensity was observed on nanostructure patterned AlGaN/AlN MQW compared to as-grown structure, demonstrating a large-scale and mass-producible pathway to higher light extraction efficiency in deep-ultra-violet light-emitting diodes.

  5. Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways.

    PubMed

    Blokhuis, Anna M; Koppers, Max; Groen, Ewout J N; van den Heuvel, Dianne M A; Dini Modigliani, Stefano; Anink, Jasper J; Fumoto, Katsumi; van Diggelen, Femke; Snelting, Anne; Sodaar, Peter; Verheijen, Bert M; Demmers, Jeroen A A; Veldink, Jan H; Aronica, Eleonora; Bozzoni, Irene; den Hertog, Jeroen; van den Berg, Leonard H; Pasterkamp, R Jeroen

    2016-08-01

    Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins. Interactomes of WT and mutant ALS proteins were very similar except for OPTN and UBQLN2, in which mutations caused loss or gain of protein interactions. Several of the identified interactomes showed a high degree of overlap: shared binding partners of ATXN2, FUS and TDP-43 had roles in RNA metabolism; OPTN- and UBQLN2-interacting proteins were related to protein degradation and protein transport, and C9orf72 interactors function in mitochondria. To confirm that this overlap is important for ALS pathogenesis, we studied fragile X mental retardation protein (FMRP), one of the common interactors of ATXN2, FUS and TDP-43, in more detail in in vitro and in vivo model systems for FUS ALS. FMRP localized to mutant FUS-containing aggregates in spinal motor neurons and bound endogenous FUS in a direct and RNA-sensitive manner. Furthermore, defects in synaptic FMRP mRNA target expression, neuromuscular junction integrity, and motor behavior caused by mutant FUS in zebrafish embryos, could be rescued by exogenous FMRP expression. Together, these results show that interactomics analysis can provide crucial insight into ALS disease mechanisms and they link FMRP to motor neuron dysfunction caused by FUS mutations.

  6. Gate length scaling effect on high-electron mobility transistors devices using AlGaN/GaN and AlInN/AlN/GaN heterostructures.

    PubMed

    Liao, S Y; Lu, C C; Chang, T; Huang, C F; Cheng, C H; Chang, L B

    2014-08-01

    Compared to AlGaN/GaN HEMT with 0.15 μm T-gate length, the AlInN/AlN/GaN one exhibits much higher current density and transconductance of 1558 mA/mm at Vd = 2 V and 330 mS/mm, respectively. The high extrinsic ft and fmax of 82 GHz and 70 GHz are extracted from AlInN/AlN/GaN HEMT. Besides, we find that the transconductance roll-off is significant in AlGaN/GaN, but largely improved in AlInN/AlN/GaN HEMT, suggesting that the high carrier density and lattice-matched epitaxial heterostructure is important to reach both large RF output power and high operation frequency, especially for an aggressively gate length scaling.

  7. Ideal Integrating Bolometer

    NASA Technical Reports Server (NTRS)

    Kogut, A.; DiPirro, M.; Moseley, S. H.

    2004-01-01

    We describe a new "ideal integrator" bolometer as a prototype for a new generation of sensitive, flexible far-IR detectors suitable for use in large arrays. The combination of a non-dissipative sensor coupled with a fast heat switch provides breakthrough capabilities in both sensitivity and operation. The bolometer temperature varies linearly with the integrated infrared power incident on the detector, and may be sampled intermittently without loss of information between samples. The sample speed and consequent dynamic range depend only on the heat switch reset cycle and can be selected in software. Between samples, the device acts as an ideal integrator with noise significantly lower than resistive bolometers. Since there is no loss of information between samples, the device is well-suited for large arrays. A single SQUID readout could process an entire column of detectors, greatly reducing the complexity, power requirements, and cost of readout electronics for large pixel arrays.

  8. Chewing over physiology integration.

    PubMed

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; Miranda, Manoel de Arcisio; Brunaldi, Kellen

    2005-03-01

    An important challenge for both students and teachers of physiology is to integrate the different areas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it comes to cuts in expenses. With the aim of addressing this kind of problem, the graduate students of our department organized a physiology summer course offered to undergraduate students. The objective was to present the different physiological systems in an integrated fashion. The strategy pursued was to plan laboratory classes whose experimental results were the basis for the relevant theoretical discussions. The subject we developed to illustrate physiology integration was the study of factors influencing salivary secretion.

  9. Partially integrated exhaust manifold

    SciTech Connect

    Hayman, Alan W; Baker, Rodney E

    2015-01-20

    A partially integrated manifold assembly is disclosed which improves performance, reduces cost and provides efficient packaging of engine components. The partially integrated manifold assembly includes a first leg extending from a first port and terminating at a mounting flange for an exhaust gas control valve. Multiple additional legs (depending on the total number of cylinders) are integrally formed with the cylinder head assembly and extend from the ports of the associated cylinder and terminate at an exit port flange. These additional legs are longer than the first leg such that the exit port flange is spaced apart from the mounting flange. This configuration provides increased packaging space adjacent the first leg for any valving that may be required to control the direction and destination of exhaust flow in recirculation to an EGR valve or downstream to a catalytic converter.

  10. Integrated digital networks

    NASA Astrophysics Data System (ADS)

    Schwartz, M.; Stern, T.; Lazar, A.

    1984-09-01

    The basic problem described in this document is that of transmitting mixtures of traffic of disparate types over a variety of communication networks. Typical examples include the transmission of interactive data, long streams of data (e.g., file transfers), voice, video, and facsimile in an integrated fashion. Network types include local area networks, metropolitan area networks, large geographically-dispersed terrestrial networks, and satellite networks. Ongoing standards work in the C CITT, supported by telephone administrations worldwide, has focused on the concept of Integrated Services Digital Networks (ISDN) toward which worldwide telecommunications will be moving. Computer manufacturers with a great deal of interest in communications (IBM is a prominent example) have begun to devote considerable effort as well to the concept of traffic integration over networks.

  11. Integrated building design

    NASA Astrophysics Data System (ADS)

    Sanguinetti, Jennifer

    2005-04-01

    For many years, building design has been a very linear process with owners speaking to architects who then design building shells that they pass along to sub-consultants who must fit their systems into the allotted spaces. While this process has some advantages, it provides little opportunity to optimize systems based on such factors as energy use or occupant comfort. This presentation will focus on the evolution and implications of integrated building design, a method that has provided greater opportunities for interaction between design disciplines and with building users early on in the design process. Integration has resulted in buildings that are more sustainable than typical buildings and that can respond better to the needs of the owner and users. Examples of the application of the process and the resulting buildings will be presented from the view of a design engineer with experience of both processes. Specifically, the potential contribution of an acoustical consultant in the integrated process will be explored.

  12. Integral diode solar cells

    SciTech Connect

    Mardesich, W.; Gillanders, M.S.

    1984-05-01

    To achieve high power at minimum weight, innovative array designs are needed. In the case where shadows fall across a series element in a simple circuit, the effective power will be reduced or eliminated. The conventional method of eliminating this loss is the introduction of bypass diodes. This method increases cost and weight and reduces available surface area. An alternative solution to the shadowing problem is to use integral diode solar cells. The integral diode cell has a built-in diode on the back that protects the adjacent cell and passes the current if it is shadowed. This paper will describe the effort to produce the integral diode cells in a production facility with a minimum cost impact. The electrical characterization of the cell as well as the diode will be presented. These cells can be readily manufactured in a production facility using photoresist defined contacting process.

  13. Chewing over physiology integration.

    PubMed

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; Miranda, Manoel de Arcisio; Brunaldi, Kellen

    2005-03-01

    An important challenge for both students and teachers of physiology is to integrate the different areas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it comes to cuts in expenses. With the aim of addressing this kind of problem, the graduate students of our department organized a physiology summer course offered to undergraduate students. The objective was to present the different physiological systems in an integrated fashion. The strategy pursued was to plan laboratory classes whose experimental results were the basis for the relevant theoretical discussions. The subject we developed to illustrate physiology integration was the study of factors influencing salivary secretion. PMID:15718383

  14. Integrated Avionics System (IAS)

    NASA Technical Reports Server (NTRS)

    Hunter, D. J.

    2001-01-01

    As spacecraft designs converge toward miniaturization and with the volumetric and mass constraints placed on avionics, programs will continue to advance the 'state of the art' in spacecraft systems development with new challenges to reduce power, mass, and volume. Although new technologies have improved packaging densities, a total system packaging architecture is required that not only reduces spacecraft volume and mass budgets, but increase integration efficiencies, provide modularity and scalability to accommodate multiple missions. With these challenges in mind, a novel packaging approach incorporates solutions that provide broader environmental applications, more flexible system interconnectivity, scalability, and simplified assembly test and integration schemes. This paper will describe the fundamental elements of the Integrated Avionics System (IAS), Horizontally Mounted Cube (HMC) hardware design, system and environmental test results. Additional information is contained in the original extended abstract.

  15. Integration and Beyond

    PubMed Central

    Stead, William W.; Miller, Randolph A.; Musen, Mark A.; Hersh, William R.

    2000-01-01

    The vision of integrating information—from a variety of sources, into the way people work, to improve decisions and process—is one of the cornerstones of biomedical informatics. Thoughts on how this vision might be realized have evolved as improvements in information and communication technologies, together with discoveries in biomedical informatics, and have changed the art of the possible. This review identified three distinct generations of “integration” projects. First-generation projects create a database and use it for multiple purposes. Second-generation projects integrate by bringing information from various sources together through enterprise information architecture. Third-generation projects inter-relate disparate but accessible information sources to provide the appearance of integration. The review suggests that the ideas developed in the earlier generations have not been supplanted by ideas from subsequent generations. Instead, the ideas represent a continuum of progress along the three dimensions of workflow, structure, and extraction. PMID:10730596

  16. Reflections on 'autistic integrity'.

    PubMed

    Russell, Barbara

    2012-03-01

    Autism, particularly its moderate to severe forms, has prompted considerable scientific study and clinical involvement because the associated behaviours imply disconnections with valued features of a 'good' life, such as close relationships, enjoyment, and adaptability. Proposed causes of autism involve potent philosophical concepts including consciousness, identity, mind, and relationality. The concept of autistic integrity is used by Barnbaum in The Ethics of Autism: Among Them, But Not of Them to help provide moral justification to stop efforts to cure adults with autism, especially if the cause is presumed to be a lack of a theory of mind.(1) This article has two goals: (1) to apply four familiar definitions or characterizations of integrity to the case of moderate to severe autism, and (2) to examine whether autistic integrity does provide the moral justification Barnbaum seeks.

  17. Integrative oncology: an overview.

    PubMed

    Deng, Gary; Cassileth, Barrie

    2014-01-01

    Integrative oncology, the diagnosis-specific field of integrative medicine, addresses symptom control with nonpharmacologic therapies. Known commonly as "complementary therapies" these are evidence-based adjuncts to mainstream care that effectively control physical and emotional symptoms, enhance physical and emotional strength, and provide patients with skills enabling them to help themselves throughout and following mainstream cancer treatment. Integrative or complementary therapies are rational and noninvasive. They have been subjected to study to determine their value, to document the problems they ameliorate, and to define the circumstances under which such therapies are beneficial. Conversely, "alternative" therapies typically are promoted literally as such; as actual antitumor treatments. They lack biologic plausibility and scientific evidence of safety and efficacy. Many are outright fraudulent. Conflating these two very different categories by use of the convenient acronym "CAM," for "complementary and alternative therapies," confuses the issue and does a substantial disservice to patients and medical professionals. Complementary and integrative modalities have demonstrated safety value and benefits. If the same were true for "alternatives," they would not be "alternatives." Rather, they would become part of mainstream cancer care. This manuscript explores the medical and sociocultural context of interest in integrative oncology as well as in "alternative" therapies, reviews commonly-asked patient questions, summarizes research results in both categories, and offers recommendations to help guide patients and family members through what is often a difficult maze. Combining complementary therapies with mainstream oncology care to address patients' physical, psychologic and spiritual needs constitutes the practice of integrative oncology. By recommending nonpharmacologic modalities that reduce symptom burden and improve quality of life, physicians also enable

  18. NASA Integrated Network COOP

    NASA Technical Reports Server (NTRS)

    Anderson, Michael L.; Wright, Nathaniel; Tai, Wallace

    2012-01-01

    Natural disasters, terrorist attacks, civil unrest, and other events have the potential of disrupting mission-essential operations in any space communications network. NASA's Space Communications and Navigation office (SCaN) is in the process of studying options for integrating the three existing NASA network elements, the Deep Space Network, the Near Earth Network, and the Space Network, into a single integrated network with common services and interfaces. The need to maintain Continuity of Operations (COOP) after a disastrous event has a direct impact on the future network design and operations concepts. The SCaN Integrated Network will provide support to a variety of user missions. The missions have diverse requirements and include anything from earth based platforms to planetary missions and rovers. It is presumed that an integrated network, with common interfaces and processes, provides an inherent advantage to COOP in that multiple elements and networks can provide cross-support in a seamless manner. The results of trade studies support this assumption but also show that centralization as a means of achieving integration can result in single points of failure that must be mitigated. The cost to provide this mitigation can be substantial. In support of this effort, the team evaluated the current approaches to COOP, developed multiple potential approaches to COOP in a future integrated network, evaluated the interdependencies of the various approaches to the various network control and operations options, and did a best value assessment of the options. The paper will describe the trade space, the study methods, and results of the study.

  19. Integrated Functionality: Nanosensors

    NASA Astrophysics Data System (ADS)

    Devreese, Jozef T.

    2008-03-01

    Integrated nanosensors are nanostructured systems in which several sensors of different types have been integrated on a single platform including those sensitive to optical, magnetic, chemical, or biological stimuli [1,2]. Nanoparticle-based detector systems rely on the development of nanoparticles as sensing species. I discuss state-of-the-art nanosensors which are based on various advanced materials: nanoshells and nanorice, gold nanoparticles with attached fluorescent dyes, nanopores, carbon nanotubes, neuroelectronic hybrid systems, semiconductor nanocrystals and quantum-dot quantum wells (QDQW's). Phonon-assisted optical processes in semiconductor nanocrystals and QDQW's are highly sensitive to their shape and geometry i. a. due to the non-adiabaticity of the exciton-phonon systems. This sensitivity opens new perspectives for applications of quantum dots in optical sensing. For example, the simultaneous consideration of the tetrahedral shape of a CdS/HgS/CdS QDQW, interface optical phonons, and non-adiabatic phonon-assisted transitions allows for control of the photoluminescence of a QDQW [3]. Quantum-dot-based systems are also considered as examples of communication with nanodevices, which is a prerequisite of their integration. Nanosensors allow for building a new class of integrated devices, which provide the elemental base for ``intelligent sensors'' capable of data processing, storage and analysis. The development of integrated nanosensors could have many applications in several fields such as process monitoring, robotics, environmental, medical, consumer, homeland security [1] I. K. Schuller, http://nanosensors.ucsd.edu/Introduction.htm. [2] J. T. Devreese and Y. Bruynseraede, Integrated Nanosensors. McGraw-Hill 2008 Yearbook of Science & Technology, McGraw-Hill, 2008. [3] V. A. Fonoberov, E. P. Pokatilov, V. M. Fomin, and J. T. Devreese, Phys. Rev. Lett. 92, 127402 (2004).

  20. Joining of Cast ZE41A Mg to Wrought 6061 Al by the Cold Spray Process and Friction Stir Welding

    NASA Astrophysics Data System (ADS)

    Champagne, Victor Kenneth; West, Michael K.; Reza Rokni, M.; Curtis, Todd; Champagne, Victor; McNally, Baillie

    2016-01-01

    This paper presents a novel method for joining cast ZE41A-T5 Mg to wrought 6061-T6 Al, without forming deleterious, coarse intermetallic compounds, which is not currently possible with conventional technologies. The novel aspect of the process includes the development of a joint design using cold spray (CS) as the enabling technology, to produce a transitional layer onto which a conventional welding technique can be employed to join the two dissimilar materials. The emphasis in this study will be on the CS transitional layer (T-layer) which enables the joining of cast ZE41A-T5 magnesium (Mg) and wrought 6061-T6 aluminum (Al) by friction-stir welding and the subsequent materials characterization to show the structural integrity of the entire joint. In order to join Mg and Al plates by this method, a transitional layer of CS Al is first deposited along the edge of cast ZE41A Mg plate. The CS Al T-layer enables the Mg to be friction stir welded to a plate of wrought 6061 Al, thereby completing the Mg plate to Al plate joint. Friction stir welding was chosen in this study to join the CS Al T-layer to the wrought Al plate; however, other conventional welding techniques could also be employed for joining Mg to Al in this manner. The CS Al T-layer is compatible to the wrought 6061 Al plate and serves as an insulating layer that prevents heat generated during the friction stir welding process from extending into the magnesium, thus preventing the formation of intermetallics. In this study, two sets of samples were produced joining cast ZE41A-T5 magnesium (Mg) and wrought 6061-T6 aluminum: one set using CS 6061 Al as the transition material between the ZE41A Mg plate and 6061 Al plate and the other set using CS 5056 Al as the transition material. Microstructural analysis by scanning and transmission electron microscopy and optical microscopy, along with mechanical test results including triple lug shear, tension, and micro hardness will be presented. Comparisons will be