2. Historic American Buildings Survey, Martin Linsey, Photographer October 26, ...

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

2. Historic American Buildings Survey, Martin Linsey, Photographer October 26, 1965 SOUTHWEST CORNER (22ND ST. SIDE). - Trinity Episcopal Church, Euclid Avenue & East Twenty-Second Street, Cleveland, Cuyahoga County, OH

2. Historic American Buildings Survey 'Stable and Smoke House' Photocopy ...

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

2. Historic American Buildings Survey 'Stable and Smoke House' Photocopy of Plate XXX From: Brown, Glenn, The Octagon, Washington, N.D. - Octagon House, Stable, 1799 New York Avenue Northwest, Washington, District of Columbia, DC

Adaptive Neuro-Fuzzy Modeling of UH-60A Pilot Vibration

NASA Technical Reports Server (NTRS)

Kottapalli, Sesi; Malki, Heidar A.; Langari, Reza

2003-01-01

Adaptive neuro-fuzzy relationships have been developed to model the UH-60A Black Hawk pilot floor vertical vibration. A 200 point database that approximates the entire UH-60A helicopter flight envelope is used for training and testing purposes. The NASA/Army Airloads Program flight test database was the source of the 200 point database. The present study is conducted in two parts. The first part involves level flight conditions and the second part involves the entire (200 point) database including maneuver conditions. The results show that a neuro-fuzzy model can successfully predict the pilot vibration. Also, it is found that the training phase of this neuro-fuzzy model takes only two or three iterations to converge for most cases. Thus, the proposed approach produces a potentially viable model for real-time implementation.

Exogenous attention enhances 2nd-order contrast sensitivity

PubMed Central

Barbot, Antoine; Landy, Michael S.; Carrasco, Marisa

2011-01-01

Natural scenes contain a rich variety of contours that the visual system extracts to segregrate the retinal image into perceptually coherent regions. Covert spatial attention helps extract contours by enhancing contrast sensitivity for 1st-order, luminance-defined patterns at attended locations, while reducing sensitivity at unattended locations, relative to neutral attention allocation. However, humans are also sensitive to 2nd-order patterns such as spatial variations of texture, which are predominant in natural scenes and cannot be detected by linear mechanisms. We assess whether and how exogenous attention—the involuntary and transient capture of spatial attention—affects the contrast sensitivity of channels sensitive to 2nd-order, texture-defined patterns. Using 2nd-order, texture-defined stimuli, we demonstrate that exogenous attention increases 2nd-order contrast sensitivity at the attended location, while decreasing it at unattended locations, relative to a neutral condition. By manipulating both 1st- and 2nd-order spatial frequency, we find that the effects of attention depend both on 2nd-order spatial frequency of the stimulus and the observer’s 2nd-order spatial resolution at the target location. At parafoveal locations, attention enhances 2nd-order contrast sensitivity to high, but not to low 2nd-order spatial frequencies; at peripheral locations attention also enhances sensitivity to low 2nd-order spatial frequencies. Control experiments rule out the possibility that these effects might be due to an increase in contrast sensitivity at the 1st-order stage of visual processing. Thus, exogenous attention affects 2nd-order contrast sensitivity at both attended and unattended locations. PMID:21356228

Characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from a UH-1H helicopter engine and its impact on the ambient environment

NASA Astrophysics Data System (ADS)

Chen, Yu-Cheng; Lee, Wen-Jhy; Uang, Shi-Nian; Lee, Su-Hsing; Tsai, Perng-Jy

The objective of this study is to characterize the emissions of polycyclic aromatic hydrocarbons (PAHs) from a UH-1H helicopter turboshaft engine and its impact on the ambient environment. Five power settings of the ground idle (GI), fly idle (FI), beed band check (BBC), inlet guide vane (IGV), and take off (TO) were selected and samples were collected from the exhaust by using an isokinetic sampling system. Twenty-two PAH compounds were analyzed by gas chromatograph (GC)/MS. We found the mean total PAH concentration in the exhaust of the UH-1H engine (843 μg m -3) is 1.05-51.7 times in magnitude higher than those of the heavy-duty diesel (HDD) engine, motor vehicle engine, and F101 aircraft engine. Two- and three-ringed PAHs account for 97.5% of total PAH emissions from the UH-1H engine. The mean total PAH and total BaP eq emission factors for the UH-1H engine (63.4 and 0.309 mg L -1·fuel) is 1.65-23.4 and 1.30-7.54 times in magnitude higher than those for the motor vehicle engine, HDD engine, and F101 aircraft engine. The total emission level of the single PAH compound, BaP, for the UH-1H engine (EL BaP) during one landing and take off (LTO) cycle (2.19 mg LTO -1) was higher than the European Commission standard (1.24 mg LTO -1) suggesting that appropriate measures should be taken to reduce PAH emissions from UH-1H engines in the future.

SCAT Classifications of 5 Supernovae with the UH88/SNIFS

NASA Astrophysics Data System (ADS)

Tucker, Michael A.; Huber, Mark; Shappee, Benjamin J.; Dong, Subo; Bose, S.; Chen, Ping

2018-03-01

We present the first classifications from the newly formed Spectral Classification of Astronomical Transients (SCAT) survey. SCAT is a transient identification survey utilizing the SuperNova Integral Field Spectrograph (SNIFS) on the University of Hawaii (UH) 88-inch telescope.

Simulated Guide Stars: Adapting the Robo-AO Telescope Simulator to UH 88”

NASA Astrophysics Data System (ADS)

Ashcraft, Jaren; Baranec, Christoph

2018-01-01

Robo-AO is an autonomous adaptive optics system that is in development for the UH 88” Telescope on the Mauna Kea Observatory. This system is capable of achieving near diffraction limited imaging for astronomical telescopes, and has seen successful deployment and use at the Palomar and Kitt Peak Observatories previously. A key component of this system, the telescope simulator, will be adapted from the Palomar Observatory design to fit the UH 88” Telescope. The telescope simulator will simulate the exit pupil of the UH 88” telescope so that the greater Robo-AO system can be calibrated before observing runs. The system was designed in Code V, and then further improved upon in Zemax for later development. Alternate design forms were explored for the potential of adapting the telescope simulator to the NASA Infrared Telescope Facility, where simulating the exit pupil of the telescope proved to be more problematic. A proposed design composed of solely catalog optics was successfully produced for both telescopes, and they await assembly as time comes to construct the new Robo-AO system.

Healing of rat mouth mucosa after irradiation with CO2, Nd:YAG, and CO2-Nd:YAG combination lasers.

PubMed

Luomanen, M; Rauhamaa-Mäkinen, R; Meurman, J H; Kosloff, T; Tiitta, O

1994-08-01

The healing process of wounds made by a combination laser was studied in 90 rats. The laser system enabled both separate and combined use of CO2 and Nd:YAG laser irradiations. The laser wounds and the control excision wounds made by alligator forceps appeared on both sides of the tongue. Specimens from the wound sites were taken immediately, 6 h, and 1, 2, 4, 7, 11, 21, 28, and 42 days after surgery. The wound-healing process was studied by macroscopic evaluation before preparing the specimens for light microscopy. Some differences were noted in the wound-healing process among the three groups into which the experimental animals were divided. Tissue coagulation damage was most extensive in the Nd:YAG laser sites, where it was observed in its full extent 4 days after surgery. Epithelial cells were seen to begin to proliferate in all the wounds 6 h after surgery. Re-epithelialization was completed by between 7 (CO2) and 21 days (Nd:YAG) at all the wound sites. The inflammatory cell infiltration was more prominent in the Nd:YAG and the CO2-Nd:YAG combination laser wounds than in the CO2 and excision wounds during healing. Tissue regeneration occurred faster with less contraction in the combination CO2-Nd:YAG wounds than in Nd:YAG wounds. The best macroscopic healing result was seen in the CO2 wound sites. The combination laser was effective both at cutting and at coagulating tissue. Combining the CO2 and Nd:YAG laser irradiation into one beam resulted in a greater incision depth than what could have been expected from using the two lasers separately.

Magnetic properties and magnetocrystalline anisotropy of Nd 2Fe 17, Nd 2Fe 17X 3, and related compounds

DOE PAGES

Pandey, Tribhuwan; Parker, David S.

2018-02-26

The electronic and magnetic properties of Nd 2Fe 17 and Nd 2Fe 17X 3 (X = C or N) compounds have been calculated using the first-principles density functional calculations. Among these, the nitrogen and carbon interstitial compounds exhibit all of the required properties such as a saturation moment of 1.6 T, Curie temperature of 700–750 K, however easy magnetic axis lies in the planar direction making them less attractive for permanent magnet applications. The calculated magnetocrystalline anisotropy energy is found to be -2.7 MJ/m 3 for Nd 2Fe 17C 3 and -4.7 MJ/m 3 for Nd 2Fe 17N 3. Finally,more » we further explored the possibility of changing the easy axis direction through La/Ce alloying at Nd site. Although the MAE is found to be smaller in magnitude for all the La/Ce alloys it still maintains planar direction.« less

Highly efficient continuous-wave laser operation of LD-pumped Nd,Gd:CaF2 and Nd,Y:CaF2 crystals

NASA Astrophysics Data System (ADS)

Pang, Siyuan; Ma, Fengkai; Yu, Hao; Qian, Xiaobo; Jiang, Dapeng; Wu, Yongjing; Zhang, Feng; Liu, Jie; Xu, Jiayue; Su, Liangbi

2018-05-01

Spectroscopic properties of Nd:CaF2 crystals are investigated. The photoluminescence intensity in the near infrared region is drastically enhanced by co-doping Gd3+ ions and Y3+ in Nd:CaF2 crystals. Preliminary laser experiments are carried out with 0.3%Nd,5%Gd:CaF2 and 0.3%Nd,5%Y:CaF2 crystals under laser diode pumping; true continuous wave laser operation is achieved with slope efficiencies of 42% and 39%, respectively, and the maximum output power reaches 1.188 W.

UNBROKEN: UH 1N AIRCREW CONTINUE OPS DESPITE WEAK HEARING PROTECTION

DTIC Science & Technology

2016-02-29

AU/ACSC/2016 AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY UNBROKEN: UH-1N AIRCREW CONTINUE OPS DESPITE WEAK HEARING... student training. The final one at Fairchild AFB, Washington, is focused on search and rescue operations and supports the Survival, Evasion

Electronic structure of layered titanate Nd 2Ti 2O 7

NASA Astrophysics Data System (ADS)

Atuchin, V. V.; Gavrilova, T. A.; Grivel, J.-C.; Kesler, V. G.

2008-10-01

The electronic structure of the binary titanate Nd 2Ti 2O 7 has been studied by X-ray photoelectron spectroscopy (XPS). Spectral features of the valence band and all constituent element core levels have been considered. The Auger parameters of titanium and oxygen in Nd 2Ti 2O 7 are determined as αTi = 873.5 and αO = 1042.2 eV. Chemical bonding effects have been discussed with the binding energies differences ΔTi = (BE O 1s - BE Ti 2p 3/2) = 71.5 eV and ΔNd = (BE Nd 3d 5/2 - BE O 1s) = 452.5 eV as key parameters in comparison with those in other titanium- and neodymium-bearing oxides.

Epitaxial growth of iridate pyrochlore Nd 2Ir 2O 7 films

DOE PAGES

Gallagher, J. C.; Esser, B. D.; Morrow, R.; ...

2016-02-29

Epitaxial films of the pyrochlore Nd 2Ir 2O 7 have been grown on (111)-oriented yttria-stabilized zirconia (YSZ) substrates by off-axis sputtering followed by post-growth annealing. X-ray diffraction (XRD) results demonstrate phase-pure epitaxial growth of the pyrochlore films on YSZ. Scanning transmission electron microscopy (STEM) investigation of an Nd 2Ir 2O 7 film with a short post-annealing provides insight into the mechanism for crystallization of Nd 2Ir 2O 7 during the post-annealing process. STEM images reveal clear pyrochlore ordering of Nd and Ir in the films. As a result, the epitaxial relationship between the YSZ and Nd 2Ir 2O 7 ismore » observed clearly while some interfacial regions show a thin region with polycrystalline Ir nanocrystals.« less

VizieR Online Data Catalog: ND2 rotational spectrum (Melosso+,

NASA Astrophysics Data System (ADS)

Melosso, M.; Degli Esposti, C.; Dore, L.

2018-01-01

files used with the SPFIT/SPCAT program suite. There are 8 files of supplementary material, including a ReadMe, which was created by the AAS data editors. The text files are as follows: 1_Explan.txt = information on the content of the other files. 2ND2.fit = the output file of the fit of spectroscopic data used in the present study. 3ND2.lin = the corresponding line file. 4ND2.par = the corresponding parameter file. 5ND2.cat = the output file of the prediction made with the parameters determined in this study. 6ND2.var = the corresponding parameter file 7ND2.int = the corresponding intensity file (1 data file).

PREFACE: 2nd International Conference on Innovative Materials, Structures and Technologies

NASA Astrophysics Data System (ADS)

Ručevskis, Sandris

2015-11-01

The 2nd International Conference on Innovative Materials, Structures and Technologies (IMST 2015) took place in Riga, Latvia from 30th September - 2nd October, 2015. The first event of the conference series, dedicated to the 150th anniversary of the Faculty of Civil Engineering of Riga Technical University, was held in 2013. Following the established tradition, the aim of the conference was to promote and discuss the latest results of industrial and academic research carried out in the following engineering fields: analysis and design of advanced structures and buildings; innovative, ecological and energy efficient building materials; maintenance, inspection and monitoring methods; construction technologies; structural management; sustainable and safe transport infrastructure; and geomatics and geotechnics. The conference provided an excellent opportunity for leading researchers, representatives of the industrial community, engineers, managers and students to share the latest achievements, discuss recent advances and highlight the current challenges. IMST 2015 attracted over 120 scientists from 24 countries. After rigorous reviewing, over 80 technical papers were accepted for publication in the conference proceedings. On behalf of the organizing committee I would like to thank all the speakers, authors, session chairs and reviewers for their efficient and timely effort. The 2nd International Conference on Innovative Materials, Structures and Technologies was organized by the Faculty of Civil Engineering of Riga Technical University with the support of the Latvia State Research Programme under the grant agreement "INNOVATIVE MATERIALS AND SMART TECHNOLOGIES FOR ENVIRONMENTAL SAFETY, IMATEH". I would like to express sincere gratitude to Juris Smirnovs, Dean of the Faculty of Civil Engineering, and Andris Chate, manager of the Latvia State Research Programme. Finally, I would like to thank all those who helped to make this event happen. Special thanks go to Diana

25. Perimeter acquisition radar building room #2M4, (mezzanine), power supply ...

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

25. Perimeter acquisition radar building room #2M4, (mezzanine), power supply room; computer power supply on left and water flow on right. This room is directly below data processing area (room #318). Sign on right reads: High purity water digital rack - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Modeling of UH-60A Hub Accelerations with Neural Networks

NASA Technical Reports Server (NTRS)

Kottapalli, Sesi

2002-01-01

Neural network relationships between the full-scale, flight test hub accelerations and the corresponding three N/rev pilot floor vibration components (vertical, lateral, and longitudinal) are studied. The present quantitative effort on the UH-60A Black Hawk hub accelerations considers the lateral and longitudinal vibrations. An earlier study had considered the vertical vibration. The NASA/Army UH-60A Airloads Program flight test database is used. A physics based "maneuver-effect-factor (MEF)", derived using the roll-angle and the pitch-rate, is used. Fundamentally, the lateral vibration data show high vibration levels (up to 0.3 g's) at low airspeeds (for example, during landing flares) and at high airspeeds (for example, during turns). The results show that the advance ratio and the gross weight together can predict the vertical and the longitudinal vibration. However, the advance ratio and the gross weight together cannot predict the lateral vibration. The hub accelerations and the advance ratio can be used to satisfactorily predict the vertical, lateral, and longitudinal vibration. The present study shows that neural network based representations of all three UH-60A pilot floor vibration components (vertical, lateral, and longitudinal) can be obtained using the hub accelerations along with the gross weight and the advance ratio. The hub accelerations are clearly a factor in determining the pilot vibration. The present conclusions potentially allow for the identification of neural network relationships between the experimental hub accelerations obtained from wind tunnel testing and the experimental pilot vibration data obtained from flight testing. A successful establishment of the above neural network based link between the wind tunnel hub accelerations and the flight test vibration data can increase the value of wind tunnel testing.

Low temperature magnetic properties of Nd2Ru2O7

NASA Astrophysics Data System (ADS)

Ku, S. T.; Kumar, D.; Lees, M. R.; Lee, W.-T.; Aldus, R.; Studer, A.; Imperia, P.; Asai, S.; Masuda, T.; Chen, S. W.; Chen, J. M.; Chang, L. J.

2018-04-01

We present magnetic susceptibility, heat capacity, and neutron diffraction measurements of polycrystalline Nd2Ru2O7 down to 0.4 K. Three anomalies in the magnetic susceptibility measurements at 146, 21 and 1.8 K are associated with an antiferromagnetic ordering of the Ru4+ moments, a weak ferromagnetic signal attributed to a canting of the Ru4+ and Nd3+ moments, and a long-range-ordering of the Nd3+ moments, respectively. The long-range order of the Nd3+ moments was observed in all the measurements, indicating that the ground state of the compound is not a spin glass. The magnetic entropy of Rln2 accumulated up to 5 K, suggests the Nd3+ has a doublet ground state. Lattice distortions accompany the transitions, as revealed by neutron diffraction measurements, and in agreement with earlier synchrotron x-ray studies. The magnetic moment of the Nd3+ ion at 0.4 K is estimated to be 1.54(2)µ B and the magnetic structure is all-in all-out as determined by our neutron diffraction measurements.

The expression characteristics of mt-ND2 gene in chicken.

PubMed

Zhang, Wenwen; Hou, Lingling; Wang, Ting; Lu, Weiwei; Tao, Yafei; Chen, Wen; Du, Xiaohui; Huang, Yanqun

2016-09-01

Subunit 2 of NADH dehydrogenase (ND2) is encoded by the mt-ND2 gene and plays a critical role in controlling the production of the mitochondrial reactive oxygen species. Our study focused on exploring the mt-ND2 tissue expression patterns and the effects of energy restriction and dietary fat (linseed oil, corn oil, sesame oil or lard) level (2.5% and 5%) on its expression in chicken. The results showed that mt-ND2 gene was expressed in the 15 tissues of hybrid chickens with the highest level in heart and lowest level in pancreas tissue; 30% energy restriction did not significantly affect mt-ND2 mRNA level in chicken liver tissue. Both the mt-ND2 mRNA levels in chicken pectoralis (p < 0.05) and hepatic tissues (p < 0.05) at 42 d-old were affected by the type of dietary fats in 5% level, while not in abdominal fat tissues. The expression of mt-ND2 in hepatic tissues was down-regulated with chicken age (p < 0.01). The interactive effect of dietary fat types with chicken age (p < 0.05) was significant on mt-ND2 mRNA level. The study demonstrated that mt-ND2 gene was extensively expressed in tissues, and the expression was affected by dietary fat types and chicken age.

Implementing the UH Asynchronous Learning Network: Practices, Issues and Challenges

ERIC Educational Resources Information Center

Odin, Jaishree K.

2002-01-01

In spite of ten campuses spread over four islands, access to higher education at the University of Hawai'i (UH) is unevenly distributed across the state. In an effort to address the problem of access, the Alfred P. Sloan Foundation has funded the University of Hawai'i to develop online courses and programs. In this article, the author describes…

Installation of C-6533(XE-2)/ARC ICS in UH-1H helicopter

NASA Astrophysics Data System (ADS)

Hnat, J. A.

1980-07-01

This report documents the results of the installation of the C-6533(XE-2)/ARC ICS in UH-1H helicopter. Installation was performed at the AEL, Inc., Monmouth County Airport facility. Design of each installation was coordinated and approved by the Government. The mechanical and electrical installation drawings for the helicopter are attached as Appendix A of this report. The new ICS system consisted of new cabling, new intercoms and helmets rewired with new microphones. All four crew stations of the helicopter were reconfigured with the new system. Existing cabling for the standard ICS system remained in the aircraft but was securely stowed for later restoration of the aircraft. The helmets (4) were rewired using separate jacks for headphones and microphone lines. Transmit and receive cables were installed in the aircraft with a minimum separation of one inch between cables. A junction box was fabricated and installed on the aft end of the console to house the fan-out terminal strips. Transmit and receive lines' separation was maintained in the junction box. During the test phase the onboard radios were used with the new ICS system.

Textured Nd2Fe14B flakes with enhanced coercivity

NASA Astrophysics Data System (ADS)

Cui, B. Z.; Zheng, L. Y.; Marinescu, M.; Liu, J. F.; Hadjipanayis, G. C.

2012-04-01

Morphology, structure, and magnetic properties of the [001] textured Nd2Fe14B nanocrystalline flakes prepared by surfactant-assisted high energy ball milling (HEBM) and subsequent annealing were studied. These flakes have a thickness of 80-200 nm, a length of 0.5-10 μm, and an average grain size of 10-14 nm. The addition of some amount of Dy, Nd70Cu30 alloy, and an appropriate post annealing increased the coercivity iHc of the Nd2Fe14B flakes. iHc was 3.7, 4.3, and 5.7 kOe for the Nd15.5Fe78.5B6, Nd14Dy1.5Fe78.5B6 and 83.3 wt.% Nd14Dy1.5Fe78.5B6 + 16.7 wt.% Nd70Cu30 flakes prepared by HEBM for 5 h in heptane with 20 wt.% oleylamine, respectively. After annealing at 450 °C for 0.5 h, their iHc increased to 5.1, 6.2, and 7.0 kOe, respectively. Anisotropic magnetic behavior was found in all of the as-milled and annealed flakes. Both, the thickening of Nd-rich phase at grain boundaries via diffusion of Nd70Cu30 and the surface modification of the Nd2Fe14B flake could be the main reasons for the coercivity enhancement in the as-milled and annealed Nd70Cu30-added Nd2Fe14B flakes.

Textured Nd2Fe14B flakes with enhanced coercivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, BZ; Zheng, LY; Marinescu, M

2012-04-01

Morphology, structure, and magnetic properties of the [001] textured Nd2Fe14B nanocrystalline flakes prepared by surfactant-assisted high energy ball milling (HEBM) and subsequent annealing were studied. These flakes have a thickness of 80-200 nm, a length of 0.5-10 mu m, and an average grain size of 10-14nm. The addition of some amount of Dy, Nd70Cu30 alloy, and an appropriate post annealing increased the coercivity H-i(c) of the Nd2Fe14B flakes. iHc was 3.7, 4.3, and 5.7 kOe for the Nd15.5Fe78.5B6, Nd14Dy1.5Fe78.5B6 and 83.3wt.% Nd14Dy1.5Fe78.5B6+16.7 wt.% Nd70Cu30 flakes prepared by HEBM for 5 h in heptane with 20 wt.% oleylamine, respectively. After annealingmore » at 450 degrees C for 0.5h, their iHc increased to 5.1, 6.2, and 7.0 kOe, respectively. Anisotropic magnetic behavior was found in all of the as-milled and annealed flakes. Both, the thickening of Nd-rich phase at grain boundaries via diffusion of Nd70Cu30 and the surface modification of the Nd2Fe14B flake could be the main reasons for the coercivity enhancement in the as-milled and annealed Nd70Cu30-added Nd2Fe14B flakes. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3679425]« less

If You Say Thee Uh You Are Describing Something Hard: The On-Line Attribution of Disfluency during Reference Comprehension

ERIC Educational Resources Information Center

Arnold, Jennifer E.; Kam, Carla L. Hudson; Tanenhaus, Michael K.

2007-01-01

Eye-tracking and gating experiments examined reference comprehension with fluent (Click on the red. . .) and disfluent (Click on [pause] thee uh red . . .) instructions while listeners viewed displays with 2 familiar (e.g., ice cream cones) and 2 unfamiliar objects (e.g., squiggly shapes). Disfluent instructions made unfamiliar objects more…

Impedance spectroscopy study of SiO2-Li2O:Nd2O3 glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pereia, R.; Gozzo, C B; Guedes, I.

2014-01-01

In the present study, neodymium-doped lithium silicate glasses have been prepared by the conventional melt-quenching technique. The dielectric properties, electric modulus and electrical conductivity of SiO2-Li2O (SiLi-0Nd) and SiO2-Li2O:Nd2O3 (SiLi-1.35Nd) have been studied from 1 Hz to 1 MHz in the 333 423 K temperature range. At a given temperature and frequency, we observe that the resistivity increases while the conductivity accordingly decreases when neodymium ions are added to the glass matrix. The activation energy of two distinct regions was evaluated from the ln( dc)=f(1/T) plot and was found to be E1(T<363K)=0.61(0.66)eV and E2(T>363K)=1.26(1.09)eV for SiLi-0Nd (SiLi-1,35Nd). The dielectric constantmore » ( Re) decreases while the dielectric loss (tan ( )) increases under Nd2O3 doping. We also observe that for both glasses, Re and tan ( ) tend to increase with increasing temperature and decrease with increasing frequency.« less

Survivability on the Island of Spice: The Development of the UH-60 Blackhawk and Its Baptism of Fire in Operation Urgent Fury

DTIC Science & Technology

2015-06-12

SURVIVABILITY ON THE ISLAND OF SPICE : THE DEVELOPMENT OF THE UH-60 BLACKHAWK AND ITS BAPTISM OF FIRE IN OPERATION URGENT FURY......THESIS APPROVAL PAGE Name of Candidate: Major Matthew G. Easley Thesis Title: Survivability on the Island of Spice : The Development of the UH

Piloted Evaluation of a UH-60 Mixer Equivalent Turbulence Simulation Model

NASA Technical Reports Server (NTRS)

Lusardi, Jeff A.; Blanken, Chris L.; Tischeler, Mark B.

2002-01-01

A simulation study of a recently developed hover/low speed Mixer Equivalent Turbulence Simulation (METS) model for the UH-60 Black Hawk helicopter was conducted in the NASA Ames Research Center Vertical Motion Simulator (VMS). The experiment was a continuation of previous work to develop a simple, but validated, turbulence model for hovering rotorcraft. To validate the METS model, two experienced test pilots replicated precision hover tasks that had been conducted in an instrumented UH-60 helicopter in turbulence. Objective simulation data were collected for comparison with flight test data, and subjective data were collected that included handling qualities ratings and pilot comments for increasing levels of turbulence. Analyses of the simulation results show good analytic agreement between the METS model and flight test data, with favorable pilot perception of the simulated turbulence. Precision hover tasks were also repeated using the more complex rotating-frame SORBET (Simulation Of Rotor Blade Element Turbulence) model to generate turbulence. Comparisons of the empirically derived METS model with the theoretical SORBET model show good agreement providing validation of the more complex blade element method of simulating turbulence.

Application of Neural Networks to Predict UH-60L Electrical Generator Condition using (IMD-HUMS) Data

DTIC Science & Technology

2006-12-01

Data transfer unit ( DTU ) • Remote data concentrator (RDC) • Main processor unit (MPU) • 2 junction boxes (JB1/JB2) • 20 drive train and...NETWORKS TO PREDICT UH-60L ELECTRICAL GENERATOR CONDITION USING (IMD-HUMS) DATA by Evangelos Tourvalis December 2006 Thesis Advisor...including the time for reviewing instruction, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the

Blade Deflection Measurements of a Full-Scale UH-60A Rotor System

NASA Technical Reports Server (NTRS)

Olson, Lawrence E.; Abrego, Anita; Barrows, Danny A.; Burner, Alpheus W.

2010-01-01

Blade deflection (BD) measurements using stereo photogrammetry have been made during the individual blade control (IBC) testing of a UH-60A 4-bladed rotor system in the 40 by 80-foot test section of the National Full-Scale Aerodynamic Complex (NFAC). Measurements were made in quadrants one and two, encompassing advance ratios from 0.15 to 0.40, thrust coefficient/solidities from 0.05 to 0.12 and rotor-system drive shaft angles from 0.0 to -9.6 deg. The experiment represents a significant step toward providing benchmark databases to be utilized by theoreticians in the development and validation of rotorcraft prediction techniques. In addition to describing the stereo measurement technique and reporting on preliminary measurements made to date, the intent of this paper is to encourage feedback from the rotorcraft community concerning continued analysis of acquired data and to solicit suggestions for improved test technique and areas of emphasis for measurements in the upcoming UH-60A Airloads test at the NFAC.

NASTRAN Modeling of Flight Test Components for UH-60A Airloads Program Test Configuration

NASA Technical Reports Server (NTRS)

Idosor, Florentino R.; Seible, Frieder

1993-01-01

Based upon the recommendations of the UH-60A Airloads Program Review Committee, work towards a NASTRAN remodeling effort has been conducted. This effort modeled and added the necessary structural/mass components to the existing UH-60A baseline NASTRAN model to reflect the addition of flight test components currently in place on the UH-60A Airloads Program Test Configuration used in NASA-Ames Research Center's Modern Technology Rotor Airloads Program. These components include necessary flight hardware such as instrument booms, movable ballast cart, equipment mounting racks, etc. Recent modeling revisions have also been included in the analyses to reflect the inclusion of new and updated primary and secondary structural components (i.e., tail rotor shaft service cover, tail rotor pylon) and improvements to the existing finite element mesh (i.e., revisions of material property estimates). Mode frequency and shape results have shown that components such as the Trimmable Ballast System baseplate and its respective payload ballast have caused a significant frequency change in a limited number of modes while only small percent changes in mode frequency are brought about with the addition of the other MTRAP flight components. With the addition of the MTRAP flight components, update of the primary and secondary structural model, and imposition of the final MTRAP weight distribution, modal results are computed representative of the 'best' model presently available.

Synergy of the Developed 6D BIM Framework and Conception of the nD BIM Framework and nD BIM Process Ontology

ERIC Educational Resources Information Center

O'Keeffe, Shawn Edward

2013-01-01

The author developed a unified nD framework and process ontology for Building Information Modeling (BIM). The research includes a framework developed for 6D BIM, nD BIM, and nD ontology that defines the domain and sub-domain constructs for future nD BIM dimensions. The nD ontology defines the relationships of kinds within any new proposed…

Substitution of Nd with other rare earth elements in melt spun Nd{sub 2}Fe{sub 14}B magnets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, D. N.; Lau, D.; Chen, Z.

2016-05-15

This is a contemporary study of rapidly quenched Nd{sub 1.6}X{sub 0.4}Fe{sub 14}B magnetic materials (where X= Nd, Y, Ce, La, Pr, Gd and Ho). A 20% substitution of the Nd component from Nd{sub 2}Fe{sub 14}B can bring about some commercial advantage. However, there will be some compromise to the magnetic performance. Light rare earth elements are definitely more abundant (Y, Ce, La) than the heavier rare earth elements, but when they are included in RE{sub 2}Fe{sub 14}B magnets they tend to lower magnetic performance and thermal stability. Substituting heavy rare earth elements (Gd, Ho) for Nd in Nd{sub 2}Fe{sub 14}Bmore » improves the thermal stability of magnets but causes a loss in magnet remanence.« less

Nd2O3-SiO2 nanocomposites: A simple sonochemical preparation, characterization and photocatalytic activity.

PubMed

Zinatloo-Ajabshir, Sahar; Mortazavi-Derazkola, Sobhan; Salavati-Niasari, Masoud

2018-04-01

Nd 2 O 3 -SiO 2 nanocomposites with enhanced photocatalytic activity have been obtained through simple and rapid sonochemical route in presence of putrescine as a new basic agent, for the first time. The influence of the mole ratio of Si:Nd, basic agent and ultrasonic power have been optimized to obtain the best Nd 2 O 3 -SiO 2 nanocomposites on shape, size and photocatalytic activity. The produced Nd 2 O 3 -SiO 2 nanocomposites have been characterized utilizing XRD, EDX, TEM, FT-IR, DRS and FESEM. Application of the as-formed Nd 2 O 3 -SiO 2 nano and bulk structures as photocatalyst with photodegradation of methyl violet contaminant under ultraviolet illumination was compared. Results demonstrated that SiO 2 has remarkable effect on catalytic performance of Nd 2 O 3 photocatalyst for decomposition. By introducing of SiO 2 to Nd 2 O 3 , decomposition efficiency of Nd 2 O 3 toward methyl violet contaminant under ultraviolet illumination was increased. Copyright © 2017 Elsevier B.V. All rights reserved.

Helicopter noise definition report: UH-60A, S-76, A-109, 206-L

DOT National Transportation Integrated Search

1981-12-31

This document presents noise data for the Sikorsky UH-60A Blackhawk, the Sikorsky S-76 Spirit, the Agusta A-109 and the Bell 206-L. The acoustical data are accompanied by phototheodolite tracking data, cockpit instrument panel photo data, and meteoro...

Spectroscopic Properties of B2O3-PbO-Nd2O3 Glasses

NASA Astrophysics Data System (ADS)

Simon, V.; Ardelean, I.; Milea, I.; Peteanu, M.; Simon, S.

Samples belonging to xNd2O3(100-x) [2B2O3·PbO] glass system, with 0≤ x≤ 40 mol%, are investigated by IR and UV-VIS spectroscopies in order to obtain evidence for the influence of Nd2O3 on the local order from 2B2O3·PbO glass matrix. Besides the IR absorption bands characteristic to lead and boron arrangements, typical absorption lines of Nd3+ ions around 4000 cm-1 and 6000 cm-1 are recorded. The 6000 cm-1 band appears only for the samples with x≥25 mol% Nd2O3. The split of some UV-VIS absorption bands arising from transitions of neodymium ions in doublet lines as well as the shift of the absorption bands as the Nd2O3 content increases denote the influence of the lead-borate matrix on the radiative transitions of the lanthanide ion.

Effect of CO2, Nd:YAG and Er:YAG Lasers on Microtensile Bond Strength of Composite to Bleached-Enamel.

PubMed

Basir, Mahshid Mohammadi; Rezvani, Mohammad Bagher; Chiniforush, Nasim; Moradi, Zohreh

2016-01-01

Tooth restoration immediately after bleaching is challenging due to the potential problems in achieving adequate bond strength. The aim of this study was to evaluate the effect of surface treatment with ER:YAG, ND:YAG, CO2 lasers and 10% sodium ascorbate solution on immediate microtensile bond strength of composite resin to recently bleached enamel. Ninety sound molar teeth were randomly divided into three main groups (n:30) : NB (without bleaching), HB (bleached with 38% carbamide peroxide) and OB (bleached with Heydent bleaching gel assisted by diode laser). Each group was divided into five subgroups (n:6) : Si (without surface treatment), Er (Er:YAG laser), CO2 (CO2 laser), Nd (Nd:YAG laser) and As (Immersion in 10% sodium ascorbate solution). The bonding system was then applied and composite build-ups were constructed. The teeth were sectioned by low speed saw to obtain enamel- resin sticks and submitted to microtensile bond testing. Statistical analyses were done using two- way ANOVA, Tukey and Tamhane tests. µTBS of bleached teeth irradiated with ND:YAG laser was not significantly different from NB-Nd group. Microtensile bond strength of OB-Er group was higher than NB-Er and HB-Er groups. The mean µTBS of HB-CO2 group was higher than NB-CO2 group; the average µTBS of HB-As and OB-As groups was also higher than NB-As group. Use of Nd:YAG, CO2 lasers and 10% sodium ascorbate solution could improve the bond strength in home-bleached specimens. Application of ND:YAG laser on nonbleached specimens and Er:YAG laser on office-bleached specimens led to the highest µTBS in comparison to other surface treatments in each main group.

Genetic diversities of MT-ND1 and MT-ND2 genes are associated with high-altitude adaptation in yak.

PubMed

Shi, Yu; Hu, Yongsong; Wang, Jie; Elzo, Mauricio A; Yang, Xue; Lai, Songjia

2018-04-01

Tibetan yak (Bos grunniens) inhabiting the Qinghai-Tibet Plateau (QTP) where the average altitude is 4000 m, is specially adapted to live at these altitudes. Conversely, cattle (B. taurus) has been found to suffer from high-altitude hypertension or heart failure when exposed to these high altitudes. Two mitochondrial genes, MT-ND1 and MT-ND2, encode two subunits of NADH dehydrogenase play an essential role in the electron transport chain of oxidative phosphorylation (OXPHOS). We sequenced these two mitochondrial genes in two bovine groups (70 Tibetan yaks and 70 Xuanhan cattle) and downloaded 300 sequences of B. taurus (cattle), 93 sequences of B. grunniens (domestic yak), and 2 sequences of B. mutus (wild yak) from NCBI to increase our understanding of the mechanisms of adaptability to hypoxia at high altitudes in yaks compared to cattle. MT-ND1 SNP m.3907 C > T, present in all Tibetan yaks, was positively associated with high-altitude adaptation (p < .0006). Specially, mutation m.3638 A > G present in all cattle, resulting in the termination of transcription, was negatively associated with high-altitude adaptation (p < .0006). Additionally, MT-ND2 SNPs m.4351 G > A and m.5218 C > T also showed positive associations with high-altitude adaptation (p < .0004). MT-ND1 haplotypes H2, H3, H4, H6, and H7 showed positive associations but haplotype H20 had a negative association with high-altitude adaptation (p < .0008). Similarly, MT-ND2 haplotypes Ha1 Ha8, Ha10, and Ha11 were positively associated whereas haplotype Ha2 was negatively associated with adaptability to high-altitudes (p < .0008). Thus, MT-ND1 and MT-ND2 can be considered as candidate genes associated with adaptation to high-altitude environments.

Coercivity enhancement in hot deformed Nd2Fe14B-type magnets by doping low-melting RCu alloys (R = Nd, Dy, Nd + Dy)

NASA Astrophysics Data System (ADS)

Lee, Y. I.; Huang, G. Y.; Shih, C. W.; Chang, W. C.; Chang, H. W.; You, J. S.

2017-10-01

Magnetic properties of the anisotropic NdFeB magnets prepared by hot pressing followed by die-upsetting NdFeB MQU-F powders doped with low-melting RCu alloy powders were explored, where RCu stands for Nd70Cu30, Dy70Cu30 and (Nd0.5Dy0.5)70Cu30, respectively. In addition, the post-annealing at 600 °C was employed to modify the microstructures and the magnetic properties of the hot deformed magnets. It is found that doping RCu alloy powders is effective in enhancing the coercivity of the hot deformed NdFeB magnets from 15.1 kOe to 16.3-19.5 kOe. For Nd70Cu30-doped magnets, the increment of coercivity is only 1.2 kOe. Meanwhile, Dy70Cu30-doped and (Nd0.5Dy0.5)70Cu30-doped magnets show an almost identical enhancement of coercivity of about 4.4 kOe. Importantly, the latter magnet shows a beneficial effect of reducing the usage of Dy from 1.6 wt% to 0.8 wt%. TEM analysis shows that nonmagnetic Nd, Dy and Cu appear at grain boundary and isolate the magnetic grains, leading to an enhancement of coercivity. Doping lower melting point Dy-lean (Nd0.5Dy0.5)70Cu30 powders into commercial MQU-F powders for making high coercivity hot deformed NdFeB magnets might be a potential and economic way for mass production.

37. MILL NO. 2, 2nd FLOOR, CLOSE SHOT OF 2 ...

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

37. MILL NO. 2, 2nd FLOOR, CLOSE SHOT OF 2 CREEL MACHINES, WHICH FEED YARN INTO KNITTING MACHINES. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

Human Factors Assessment of the UH-60M Common Avionics Architecture System (CAAS) Crew Station During the Limited User Evaluation (LEUE)

DTIC Science & Technology

2005-12-01

weapon system evaluation as a high-level architecture and distributed interactive simulation 6 compliant, human-in-the-loop, virtual environment...Directorate to participate in the Limited Early User Evaluation (LEUE) of the Common Avionics Architecture System (CAAS) cockpit. ARL conducted a human...CAAS, the UH-60M PO conducted a limited early user evaluation (LEUE) to evaluate the integration of the CAAS in the UH-60M crew station. The

Experimental Investigation and Fundamental Understanding of a Slowed UH-60A Rotor at High Advance Ratios

NASA Technical Reports Server (NTRS)

Datta, Anubhav; Yeo, Hyeonsoo; Norman, Thomas R.

2011-01-01

This paper describes and analyzes the measurements from a full-scale, slowed RPM, UH-60A rotor tested at the National Full-Scale Aerodynamics Complex 40- by 80- ft wind tunnel up to an advance ratio of 1.0. A comprehensive set of measurements, that includes performance, blade loads, hub loads and pressures/airloads makes this data set unique. The measurements reveal new and rich aeromechanical phenomena that are special to this exotic regime. These include reverse chord dynamic stall, retreating side impulse in pitch-link load, large inboard-outboard elastic twist differential, supersonic flow at low subsonic advancing tip Mach numbers, diminishing rotor forces yet dramatic build up of blade loads, and dramatic blade loads yet benign levels of vibratory hub loads. The objective of this research is the fundamental understanding of these unique aeromechanical phenomena. The intent is to provide useful knowledge for the design of high speed, high efficiency, slowed RPM rotors of the future and a challenging database for advanced analyses validation.

Near-infrared luminescence of Bi2ZnOB2O6:Nd3+/PMMA composite

NASA Astrophysics Data System (ADS)

Jaroszewski, K.; Głuchowski, P.; Chrunik, M.; Jastrząb, R.; Majchrowski, A.; Kasprowicz, D.

2018-01-01

Near-infrared luminescence of a novel polymer composite system: PMMA doped with Bi2ZnOB2O6:Nd3+ microparticles, is reported for the first time. Luminescence properties of Bi2ZnOB2O6:Nd3+/PMMA were analyzed on the basis on excitation and emission spectra as well as fluorescence decay profiles. Excitation spectra monitored at 1062 nm (4F3/2 → 4I11/2) indicate numerous bands related to the optical transition of Nd3+ ions: from the 4I9/2 ground state to the 4D3/2, 2P1/2, 2K15/2, 4G7/2 + 4G9/2, 2K13/2, 4G5/2 + 2G7/2, 2H11/2, 4F9/2, 4F7/2 + 4S3/2, 4F5/2 + 2H9/2, 4F3/2 excited states. Many of them may be utilized to excite near-infrared emission of Nd3+ ions. In particular, distinctive Nd3+ emissions of the 4F3/2 → 4I9/2 and 4F3/2 → 4I11/2 transitions were detected, under excitation at 514 nm. The fluorescence decay profiles monitored at 1062 nm, excited at 514 nm, show relatively long emission lifetime of the 4F3/2 → 4I11/2 transition equal to 85 μs. Raman spectroscopy was used to determine vibrational properties and homogeneity of Bi2ZnOB2O6:Nd3+/PMMA composites. The obtained results suggest that Bi2ZnOB2O6:Nd3+/PMMA composite may be applied as an effective source of near-infrared emission in a new integrated optoelectronic devices.

Using Fly-By-Wire Technology in Future Models of the UH-60 and Other Rotary Wing Aircraft

NASA Technical Reports Server (NTRS)

Solem, Courtney K.

2011-01-01

Several fixed-winged airplanes have successfully used fly-by-wire (FBW) technology for the last 40 years. This technology is now beginning to be incorporated into rotary wing aircraft. By using FBW technology, manufacturers are expecting to improve upon the weight, maintenance time and costs, handling and reliability of the aircraft. Before mass production of this new system begins in new models such as the UH-60MU, testing must be conducted to insure the safety of this technology as well as to reassure others it will be worth the time and money to make such a dramatic change to a perfectly functional machine. The RASCAL JUH-60A has been modified for these purposes. This Black Hawk helicopter has already been equipped with the FBW technology and can be configured as a near perfect representation of the UH-60MU. Because both machines have very similar qualities, the data collected from the RASCAL can be used to make future decisions about the UH-60MU. The U.S. Army AFDD Flight Project Office oversees all the design modifications for every hardware system used in the RASCAL aircraft. This project deals with specific designs and analyses of unique RASCAL aircraft subsystems and their modifications to conduct flight mechanics research.

2nd & 3rd Generation Vehicle Subsystems

NASA Technical Reports Server (NTRS)

2000-01-01

This paper contains viewgraph presentation on the "2nd & 3rd Generation Vehicle Subsystems" project. The objective behind this project is to design, develop and test advanced avionics, power systems, power control and distribution components and subsystems for insertion into a highly reliable and low-cost system for a Reusable Launch Vehicles (RLV). The project is divided into two sections: 3rd Generation Vehicle Subsystems and 2nd Generation Vehicle Subsystems. The following topics are discussed under the first section, 3rd Generation Vehicle Subsystems: supporting the NASA RLV program; high-performance guidance & control adaptation for future RLVs; Evolvable Hardware (EHW) for 3rd generation avionics description; Scaleable, Fault-tolerant Intelligent Network or X(trans)ducers (SFINIX); advance electric actuation devices and subsystem technology; hybrid power sources and regeneration technology for electric actuators; and intelligent internal thermal control. Topics discussed in the 2nd Generation Vehicle Subsystems program include: design, development and test of a robust, low-maintenance avionics with no active cooling requirements and autonomous rendezvous and docking systems; design and development of a low maintenance, high reliability, intelligent power systems (fuel cells and battery); and design of a low cost, low maintenance high horsepower actuation systems (actuators).

Nd3+, Y3+-codoped SrF2 laser ceramics

NASA Astrophysics Data System (ADS)

Li, Weiwei; Mei, Bingchu; Song, Jinghong

2015-09-01

0.15 at.% Nd3+, 5 at.% Y3+-codoped SrF2 laser ceramic based on single crystal was prepared by extensive plastic deformation. Microstructure, optical and laser properties of the Nd3+, Y3+:SrF2 ceramic were investigated. The lasing of Nd3+, Y3+-codoped SrF2 ceramics with diode pumping have been observed and true CW laser operation around 1057 nm and 1050 nm was obtained with a slope efficiency of 31.9%. In particular, the fracture toughness of the ceramic is 0.98 MPa m1/2, which is approximately two times higher than that of single crystal.

Synthesis and Characterization of Nd(3+)-Doped CaF2 Nanoparticles.

PubMed

Yuan, Dan; Li, Weiwei; Mei, Bingchu; Song, Jinghong

2015-12-01

The Ca(1-x)F(2+x):Nd(x) nanoparticles were synthesized by chemical direct precipitation method. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Image analyzer, absorption spectrum and transmittance were taken to characterization the phases, morphologies, sizes, size distribution and optical properties of the samples. The results indicate that the Ca(1-x)F(2+x):Nd(x) samples can be rationally modified in size and morphology by altering the Nd3+ ions doping concentration. With increasing concentration of Nd3+ ions, the particle size decreased from 24 to 14 nm, the intensity of the diffraction peaks decreased, the Ca(1-x)F(2+x):Nd(x) particles aggregated ion of the formed clusters which should have an effect on both speed and orientation of the particles growth. The transmittance of ceramics with a thickness of 2 mm showed that the transmittance can reach 90% when the doping concentration was 5%, which should be profitable for LD pumping.

Airworthiness and Flight Characteristics Evaluation, UH-60A (Black Hawk) Helicopter

DTIC Science & Technology

1981-09-01

ACTIVITY EDWARDS AIR FORCE BASE, CALIFORNIA 93523 8..30 83 09 0 1 n 04 DISCLoAIMER NOTICE The findings of this report are not to be constrned as an...EDWARDS AIR FORCE BASE, CALIFORNJA 68-0-BH031.-01-68 II. CONTROLLING OFFICE NAME AND ADORESS 1I. REPORT OATS US ARMY AVN RESEARCH & DEVELOPMENT COMMAND...34| conipliance with the applicable paragraphs of the Prime Item Development Specification The UH-60A was tested at Edwards Air Force Base. California

Comparison of NASTRAN analysis with ground vibration results of UH-60A NASA/AEFA test configuration

NASA Technical Reports Server (NTRS)

Idosor, Florentino; Seible, Frieder

1990-01-01

Preceding program flight tests, a ground vibration test and modal test analysis of a UH-60A Black Hawk helicopter was conducted by Sikorsky Aircraft to complement the UH-60A test plan and NASA/ARMY Modern Technology Rotor Airloads Program. The 'NASA/AEFA' shake test configuration was tested for modal frequencies and shapes and compared with its NASTRAN finite element model counterpart to give correlative results. Based upon previous findings, significant differences in modal data existed and were attributed to assumptions regarding the influence of secondary structure contributions in the preliminary NASTRAN modeling. An analysis of an updated finite element model including several secondary structural additions has confirmed that the inclusion of specific secondary components produces a significant effect on modal frequency and free-response shapes and improves correlations at lower frequencies with shake test data.

Intrinsic evolution of novel (Nd, MM)2Fe14B-system magnetic flakes

NASA Astrophysics Data System (ADS)

Yu, Xiaoqiang; Zhu, Minggang; Liu, Weiqiang; Li, Yanfeng; Zhang, Jiuxing; Yue, Ming; Li, Wei

2018-01-01

The Nd-substituted (Nd x MM1- x )-Fe-B strip-casting flakes were prepared by induction melting in the vacuum furnace and then subsequently by strip-casting technology. The microstructure and magnetic properties of (Nd x MM1- x )-Fe-B alloys are related to the Nd substitution. 2:14:1 main phases and minor impure phases coexist in the MM-Fe-B flake. For example, La2O3 and CeFe2 impure phases are obviously detected in the x = 0 specimen. As an increase of the Ce concentration is inversely accompanied with the decrease of the Nd content ( x) in (Nd x MM1- x )2Fe14B main phases (0 ≤ x ≤ 1), XRD analysis shows that the overall diffraction peaks of the main phases shift to right domestically because of smaller radius Ce4+. The melting point, spin reorientation phase transition temperature, Curie temperature, magneto-crystalline anisotropy field (at 300 K), and the magnetization ( M 9T) for MM-Fe-B/(Nd0.4MM0.6)-Fe-B/(Nd0.7MM0.3)-Fe-B/Nd-Fe-B strip-casting alloys are 1376.15/1414.15/1439.15/1458.15 K, 74/113/124/135 K, 493.2/538.4/559.7/582.3 K, 48/55.2/64.4/70.1 kOe and 136.5/143.7/151.5/153.7 emu/g, respectively. Due to the varied composition of hard magnetic main phases, M 9T increases gradually with the increase of Nd content ( x). SEM observation and EDX results demonstrate that more Nd and Pr elements aggregate into the 2:14:1 ferromagnetic phase, while less La and Ce elements are prone to the RE-rich region compared with the nominal ratio. As a result, the growth of M 9T becomes extraordinary under maximum external field 9 T, indicating that the (Nd0.7MM0.3)-Fe-B flake may display relatively good magnetic properties and those with higher Nd content have evident effect on magnetization, compositions, and microstructures of hard magnetic main phases. Therefore, practical application of (Nd x MM1- x )-Fe-B-sintered magnets will be very prospective.

The choice: Welding with CO2 or Nd:YAG lasers

NASA Astrophysics Data System (ADS)

Leong, Keng H.

The recent commercial availability of multi-kilowatt Nd:YAG lasers has opened new avenues for rapid laser processing as well as intensified the competition (cost effectiveness) between CO2 and Nd:YAG laser systems. Vendors offering Nd:YAG laser systems may claim lower operating costs (than CO2) and fiberoptic beam delivery flexibility while CO2 systems vendors may emphasize lower capital cost and well established processing requirements and experience. The capital and operating costs of a laser system are impacted by demand and supply economics and technological advances. Frequently the total cost of a workcell using a laser for processing has to be considered rather than the laser system alone. Consequently it is not very practical to approach the selection of a laser system based on its capital cost and estimated operating cost only. This presentation describes a more pragmatic approach to aid the user in the selection of the optimal multi-kilowatt laser system for a particular processing requirement with emphasis on welding. CO2 laser systems are well established on the factory floor. Consequently, emphasis is given to the comparative application of Nd:YAG lasers, process requirements and performance. Requirements for the laser welding of different metals are examined in the context of hardware (laser system and beam delivery) selection and examples of welding speeds that can be achieved using CO2 and Nd:YAG lasers are examined.

An evolutionary switch in ND2 enables Src kinase regulation of NMDA receptors

NASA Astrophysics Data System (ADS)

Scanlon, David P.; Bah, Alaji; Krzeminski, Mickaël; Zhang, Wenbo; Leduc-Pessah, Heather L.; Dong, Yi Na; Forman-Kay, Julie D.; Salter, Michael W.

2017-05-01

The non-receptor tyrosine kinase Src is a key signalling hub for upregulating the function of N-methyl D-aspartate receptors (NMDARs). Src is anchored within the NMDAR complex via NADH dehydrogenase subunit 2 (ND2), a mitochondrially encoded adaptor protein. The interacting regions between Src and ND2 have been broadly identified, but the interaction between ND2 and the NMDAR has remained elusive. Here we generate a homology model of ND2 and dock it onto the NMDAR via the transmembrane domain of GluN1. This interaction is enabled by the evolutionary loss of three helices in bilaterian ND2 proteins compared to their ancestral homologues. We experimentally validate our model and demonstrate that blocking this interaction with an ND2 fragment identified in our experimental studies prevents Src-mediated upregulation of NMDAR currents in neurons. Our findings establish the mode of interaction between an NMDAR accessory protein with one of the core subunits of the receptor.

146Sm-142Nd systematics measured in enstatite chondrites reveals a heterogeneous distribution of 142Nd in the solar nebula.

PubMed

Gannoun, Abdelmouhcine; Boyet, Maud; Rizo, Hanika; El Goresy, Ahmed

2011-05-10

The short-lived (146)Sm-(142)Nd chronometer (T(1/2) = 103 Ma) is used to constrain the early silicate evolution of planetary bodies. The composition of bulk terrestrial planets is then considered to be similar to that of primitive chondrites that represent the building blocks of rocky planets. However for many elements chondrites preserve small isotope differences. In this case it is not always clear to what extent these variations reflect the isotope heterogeneity of the protosolar nebula rather than being produced by the decay of parent isotopes. Here we present Sm-Nd isotopes data measured in a comprehensive suite of enstatite chondrites (EC). The EC preserve (142)Nd/(144)Nd ratios that range from those of ordinary chondrites to values similar to terrestrial samples. The EC having terrestrial (142)Nd/(144)Nd ratios are also characterized by small (144)Sm excesses, which is a pure p-process nuclide. The correlation between (144)Sm and (142)Nd for chondrites may indicate a heterogeneous distribution in the solar nebula of p-process matter synthesized in supernovae. However to explain the difference in (142)Nd/(144)Nd ratios, 20% of the p-process contribution to (142)Nd is required, at odds with the value of 4% currently proposed in stellar models. This study highlights the necessity of obtaining high-precision (144)Sm measurements to interpret properly measured (142)Nd signatures. Another explanation could be that the chondrites sample material formed in different pulses of the lifetime of asymptotic giant branch stars. Then the isotope signature measured in SiC presolar would not represent the unique s-process signature of the material present in the solar nebula during accretion.

High Precision 142Nd/144Nd and 143Nd/144Nd Isotope Ratio Measurements in Rock Samples

NASA Astrophysics Data System (ADS)

Ali, A.; Srinivasan, G.

2009-05-01

The long-lived 147Sm-143Nd system with a half-life (T1/2) of 106 Gyr is generally used for geochronology. The short-lived 146Sm-142Nd system (T1/2= 103 Myr) is used as a geological tracer to track early (˜500 Ma) silicate differentiation [1] events in different planetary bodies. The isotope composition measurements by thermal ionization mass spectrometry (TIMS) require purification of Nd using chemical separation methods. This is important as an impure sample will give both a very poor ion yield and cause beam instability in the mass spectrometer, potentially resulting in a poor analysis [2]. The separation of Nd for 143Nd isotope measurement is, fairly straightforward because there is no isobaric interference of any other REE. While 142Nd isotope analysis needs chemically separated Nd fraction to be ˜100% Ce-free as latter is composed of a substantial amount of 142Ce isotope. A 4-steps technique, modified from Caro et al., [3], for the separation of Nd is established at the Cosmochemistry Laboratory of University of Toronto, Canada and applied to the measurement of Nd isotope ratios in geological reference sample BCR-2 (USGS, Columbia River basalt) using TIMS. Results of the isotopic ratios obtained for BCR-2 are in good agreement with published values [e.g., 4]. Analytical work on the samples discovered as the oldest rocks on Earth [5] from Nuvvuagittuq greenstone belt in Québec, Canada and various meteorites is in progress. An account of the procedures involved is briefly described here. All working solutions and acids were prepared using >18.2 MΩ.cm-1 H2O from a Milli-Q water system. Experiments were performed under Class 100 clean work bench with acid-cleaned apparatus and plastic-ware. The whole rock powders were weighed (20-30 mg) and dissolved in a mixture of HF and HNO3 using PFA vials and heated at 110°C. Further decomposition was done in Teflon bomb in the oven at 205°C. Later on contents of the Teflon bomb were transferred to vials and fluorides

33. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

33. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 VIEW OF STAIR FROM 2nd STORY HALL, W. END OF BUILDING - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

Analysis of propulsion system dynamics in the validation of a high-order state space model of the UH-60

NASA Technical Reports Server (NTRS)

Kim, Frederick D.

1992-01-01

Frequency responses generated from a high-order linear model of the UH-60 Black Hawk have shown that the propulsion system influences significantly the vertical and yaw dynamics of the aircraft at frequencies important to high-bandwidth control law designs. The inclusion of the propulsion system comprises the latest step in the development of a high-order linear model of the UH-60 that models additionally the dynamics of the fuselage, rotor, and inflow. A complete validation study of the linear model is presented in the frequency domain for both on-axis and off-axis coupled responses in the hoverflight condition, and on-axis responses for forward speeds of 80 and 120 knots.

Quantum origins of moment fragmentation in Nd2Zr2O7

NASA Astrophysics Data System (ADS)

Benton, Owen

2016-09-01

Spin-liquid states are often described as the antithesis of magnetic order. Recently, however, it has been proposed that in certain frustrated magnets the magnetic degrees of freedom may "fragment" in such a way as to give rise to a coexistence of spin liquid and ordered phases. Recent neutron-scattering results [S. Petit, E. Lhotel, B. Canals, M. Ciomaga Hatnean, J. Ollivier, H. Muttka, E. Ressouche, A. R. Wildes, M. R. Lees, and G. Balakrishnan, Nat. Phys. 12, 746 (2016), 10.1038/nphys3710] suggest that this scenario may be realized in the pyrochlore magnet Nd2Zr2O7 . These observations show the characteristic pinch-point features of a Coulombic spin liquid occurring alongside the Bragg peaks of an "all-in-all-out" ordered state. Here we explain the quantum origins of this apparent magnetic moment fragmentation, within the framework of a quantum model of nearest-neighbor exchange, appropriate to Nd2Zr2O7 . This model is able to capture both the ground-state order and the pinch points observed at finite energy. The observed fragmentation arises due to the combination of the unusual symmetry properties of the Nd3 + ionic wave functions and the structure of equations of motion of the magnetic degrees of freedom. The results of our analysis suggest that Nd2Zr2O7 is proximate to a U (1 ) spin-liquid phase and is a promising candidate for the observation of a Higgs transition in a magnetic system.

11. Historic American Buildings Survey Allen L. Hubbard, Photographer December ...

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

11. Historic American Buildings Survey Allen L. Hubbard, Photographer December 1, 1936 SOUTHWEST CORNER ROOM (2nd floor, east wall) - Fort Western, Main Building, Bowman Street, Augusta, Kennebec County, ME

10. Historic American Buildings Survey Allen L. Hubbard, Photographer December ...

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

10. Historic American Buildings Survey Allen L. Hubbard, Photographer December 1, 1936 (Northwest cor. room 2nd floor) East Wall - Fort Western, Main Building, Bowman Street, Augusta, Kennebec County, ME

146Sm–142Nd systematics measured in enstatite chondrites reveals a heterogeneous distribution of 142Nd in the solar nebula

PubMed Central

Gannoun, Abdelmouhcine; Boyet, Maud; Rizo, Hanika; El Goresy, Ahmed

2011-01-01

The short-lived 146Sm–142Nd chronometer (T1/2 = 103 Ma) is used to constrain the early silicate evolution of planetary bodies. The composition of bulk terrestrial planets is then considered to be similar to that of primitive chondrites that represent the building blocks of rocky planets. However for many elements chondrites preserve small isotope differences. In this case it is not always clear to what extent these variations reflect the isotope heterogeneity of the protosolar nebula rather than being produced by the decay of parent isotopes. Here we present Sm–Nd isotopes data measured in a comprehensive suite of enstatite chondrites (EC). The EC preserve 142Nd/144Nd ratios that range from those of ordinary chondrites to values similar to terrestrial samples. The EC having terrestrial 142Nd/144Nd ratios are also characterized by small 144Sm excesses, which is a pure p-process nuclide. The correlation between 144Sm and 142Nd for chondrites may indicate a heterogeneous distribution in the solar nebula of p-process matter synthesized in supernovae. However to explain the difference in 142Nd/144Nd ratios, 20% of the p-process contribution to 142Nd is required, at odds with the value of 4% currently proposed in stellar models. This study highlights the necessity of obtaining high-precision 144Sm measurements to interpret properly measured 142Nd signatures. Another explanation could be that the chondrites sample material formed in different pulses of the lifetime of asymptotic giant branch stars. Then the isotope signature measured in SiC presolar would not represent the unique s-process signature of the material present in the solar nebula during accretion. PMID:21515828

Effects of trace elements on the crystal field parameters of Nd ions at the surface of Nd{sub 2}Fe{sub 14}B grains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toga, Yuta; Suzuki, Tsuneaki; Sakuma, Akimasa, E-mail: sakuma@solid.apph.tohoku.ac.jp

2015-06-14

Using first-principles calculations, we investigate the positional dependence of trace elements such as O and Cu on the crystal field parameter A{sub 2}{sup 0}, proportional to the magnetic anisotropy constant K{sub u} of Nd ions placed at the surface of Nd{sub 2}Fe{sub 14}B grains. The results suggest the possibility that the A{sub 2}{sup 0} parameter of Nd ions at the (001) surface of Nd{sub 2}Fe{sub 14}B grains exhibits a negative value when the O or Cu atom is located near the surface, closer than its equilibrium position. At the (110) surface, however, O atoms located at the equilibrium position providemore » a negative A{sub 2}{sup 0}, while for Cu additions A{sub 2}{sup 0} remains positive regardless of Cu's position. Thus, Cu atoms are expected to maintain a positive local K{sub u} of surface Nd ions more frequently than O atoms when they approach the grain surfaces in the Nd-Fe-B grains.« less

Comparison of magnetic and thermoelectric properties of (Nd,Ca)BaCo2O5.5 and (Nd,Ca)CoO3

NASA Astrophysics Data System (ADS)

Kolesnik, S.; Dabrowski, B.; Chmaissem, O.; Wojciechowski, K.; Świerczek, K.

2012-04-01

Magnetic and thermoelectric properties of Nd1-xCaxBaCo2O5.5 and Nd1-xCaxCoO3 have been studied. Ca doping in Nd1-xCaxBaCo2O5.5 (x ≤ 0.2) preserves the metal to insulator transition (MIT) at 340-360 K. While the antiferromagnetic state disappears upon doping, the Curie temperature is increasing and becomes close to MIT for x > 0.12. The magnetic susceptibility of Nd1-xCaxCoO3 is paramagnetic for x up to 0.2, similar to the parent compound, with some indication of cluster-glass-like behavior at temperatures below 30 K. The increasing effective paramagnetic moments with doping suggest a low spin state of Co3+ and a high spin state of Co4+. Maximum observed ZT reaches a value close to 0.2 for x = 0.15 at 800 K, which is one of the highest values for perovskite cobaltites.

Tunability of morphological properties of Nd-doped TiO2 thin films

NASA Astrophysics Data System (ADS)

Rehan, Imran; Sultana, Sabiha; Khan, Nauman; Qamar, Zahid; Rehan, Kamran

2016-11-01

In this work, an endeavor is made toward structural assessment and morphological variation of titanium dioxide (TiO2) thin films when doped with neodymium (Nd). The electron beam deposition technique was employed to fabricate Nd-based TiO2 thin films on n-Type Si substrates. Nd concentration was varied from 0.0 to 2.0 atomic percent (at.%) under identical growth environments. The films were deposited in an oxygen-deficient environment to cause the growth of rutile phases. Energy dispersive x-ray spectroscopy confirmed the presence and variation of Nd dopant in TiO2. X-ray diffraction analysis showed the transformation of amorphous structures of the as-grown samples to anatase polycrystalline after annealing at 500 °C, while atomic force microscopy exposed linearity in grain density in as-grown samples with doping until 1 at.%. Raman spectrums of as-grown and annealed samples revealed the growth of the anatase phase in the annealed samples. Based on these results it can be proposed that Nd doping has pronounced effects on the structural characteristics of TiO2 thin films.

Telemental Health Training, Team Building, and Workforce Development in Cultural Context: The Hawaii Experience.

PubMed

Alicata, Daniel; Schroepfer, Amanda; Unten, Tim; Agoha, Ruby; Helm, Susana; Fukuda, Michael; Ulrich, Daniel; Michels, Stanton

2016-04-01

The goal of the University of Hawaii (UH) child and adolescent psychiatry telemental health (TMH) program is to train child and adolescent psychiatry fellows to provide behavioral health services for the children of Hawaii and the Pacific Islands in the cultural context of their rural communities using interactive videoteleconferencing (IVTC). The training experience balances learning objectives with community service. Learning objectives include: Understanding mental health disparities in rural communities, leveraging community resources in ongoing treatment, providing culturally effective care, and improving health care access and delivery through TMH service research and evaluation. We describe the UH experience. Several UH faculty are experienced with IVTC technology. They are triple-board trained, are recognized for their research in program evaluation and mental health disparities, and are committed to serving Hawaii's rural communities. We demonstrate the role of TMH in linking children and their families living in rural communities with multiple mental health treatment providers. The service-learning curriculum and a unique collaboration with Mayo Clinic provide the opportunity to examine the role of TMH in global service, and training, education, and research. TMH provides direct services to patients and consultation on Hawaii Island and Maui County. The collaboration with the Mayo Clinic brings further consultation in complex diagnostics, pharmacogenomics, and cross-cultural psychiatry. A curriculum provides trainees experience with IVTC with the goal of potential recruitment to underserved rural communities. The TMH program at UH is unique in its team building and workforce development by joining multiple entities through IVTC and translating expertise from the Mayo Clinic to rural communities, and strengthening collaboration with local child and adolescent psychiatrists, and primary care and other mental health providers. The UH psychiatry program is a

NIR emitting K2SrCl4:Eu2+, Nd3+ phosphor as a spectral converter for CIGS solar cell

NASA Astrophysics Data System (ADS)

Tawalare, P. K.; Bhatkar, V. B.; Omanwar, S. K.; Moharil, S. V.

2018-05-01

Intense near-infrared emitting phosphor K2SrCl4:Eu2+,Nd3+ with various concentrations of Nd3+ were synthesized. These are characterized with X-ray diffraction, reflectance, photoluminescence emission and photoluminescence excitation spectroscopy, PL lifetime measurements. The emission can be excited by a broad band in near ultra violet region as a consequence of Eu2+→Nd3+ energy transfer. The efficiency of Eu2+→Nd3+ energy transfer is as high as 95%. Fluorescence decay curves for Eu2+ doped samples are almost exponential and described by τ = 500 ns. Eu2+ lifetimes are shortened after Nd3+ doping. Near infrared Emission intensity is limited by Nd3+→Nd3+ energy transfer and the consequent concentration quenching. Nd3+ emission matches well with the spectral response of CIGS and CIS solar cells. Absorption of near ultra violet radiations followed by conversion to near infrared indicates the potential application in solar photovoltaics.

Comparison of Computed and Measured Vortex Evolution for a UH-60A Rotor in Forward Flight

NASA Technical Reports Server (NTRS)

Ahmad, Jasim Uddin; Yamauchi, Gloria K.; Kao, David L.

2013-01-01

A Computational Fluid Dynamics (CFD) simulation using the Navier-Stokes equations was performed to determine the evolutionary and dynamical characteristics of the vortex flowfield for a highly flexible aeroelastic UH-60A rotor in forward flight. The experimental wake data were acquired using Particle Image Velocimetry (PIV) during a test of the fullscale UH-60A rotor in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel. The PIV measurements were made in a stationary cross-flow plane at 90 deg rotor azimuth. The CFD simulation was performed using the OVERFLOW CFD solver loosely coupled with the rotorcraft comprehensive code CAMRAD II. Characteristics of vortices captured in the PIV plane from different blades are compared with CFD calculations. The blade airloads were calculated using two different turbulence models. A limited spatial, temporal, and CFD/comprehensive-code coupling sensitivity analysis was performed in order to verify the unsteady helicopter simulations with a moving rotor grid system.

V/STOL AND digital avionics system for UH-1H

NASA Technical Reports Server (NTRS)

Liden, S.

1978-01-01

A hardware and software system for the Bell UH-1H helicopter was developed that provides sophisticated navigation, guidance, control, display, and data acquisition capabilities for performing terminal area navigation, guidance and control research. Two Sperry 1819B general purpose digital computers were used. One contains the development software that performs all the specified system flight computations. The second computer is available to NASA for experimental programs that run simultaneously with the other computer programs and which may, at the push of a button, replace selected computer computations. Other features that provide research flexibility include keyboard selectable gains and parameters and software generated alphanumeric and CRT displays.

Magnetic structure of the ferromagnetic new ternary silicide Nd5CoSi2.

PubMed

Mayer, C; Gaudin, E; Gorsse, S; Porcher, F; André, G; Chevalier, B

2012-04-04

Nd(5)CoSi(2) was obtained from the elements by arc-melting followed by annealing at 883 K. Its investigation by single-crystal x-ray and neutron powder diffraction shows that this ternary silicide crystallizes as Nd(5)Si(3) in a tetragonal structure deriving from the Cr(5)B(3)-type (I4/mcm space group; a = 7.7472(2) and c = 13.5981(5) Å as unit cell parameters). The structural refinements confirm the mixed occupancy on the 8h site between Si and Co atoms, as already observed for Gd(5)CoSi(2). Magnetization and specific heat measurements reveal a ferromagnetic behavior below T(C) = 55 K for Nd(5)CoSi(2). This magnetic ordering is further evidenced by neutron powder diffraction investigation revealing between 1.8 K and T(C) a canted ferromagnetic structure in the direction of the c-axis described by a propagation vector k = (0 0 0). At 1.8 K, the two Nd(3+) ions carry ordered magnetic moments equal respectively to 1.67(7) and 2.37(7) μ(B) for Nd1 and Nd2; these two moments exhibit a canting angle of θ = 4.3(6)°. This magnetic structure presents some similarities with that reported for Nd(5)Si(3). © 2012 IOP Publishing Ltd

2Flux growth and characterization of Ce-substituted Nd 2 Fe 14 B single crystals

DOE PAGES

Susner, Michael A.; Conner, Benjamin S.; Saparov, Bayrammurad I.; ...

2016-10-27

Single crystals of (Nd 1-xCe x) 2Fe 14B are grown out of Fe-(Nd,Ce) flux. Chemical and structural analysis of the crystals indicate that (Nd 1-xCe x) 2Fe 14B forms a solid solution until at least x = 0.38 with a Vegard-like variation of the lattice constants with x. Refinements of single crystal neutron diffraction data indicate that Ce has a slight site preference (7:3) for the 4g rare earth site over the 4f site. Magnetization measurements at 300 K show only small decreases with increasing Ce content in saturation magnetization (M s) and anisotropy field (H A), and Curie temperaturemore » (T C). First principles calculations are carried out to understand the effect of Ce substitution on the electronic and magnetic properties. For a multitude of applications, it is expected that the advantage of incorporating lower-cost and more abundant Ce will outweigh the small adverse effects on magnetic properties. In conclusion, Ce-substituted Nd 2Fe 14B is therefore a potential high-performance permanent magnet material with substantially reduced Nd content.« less

ICESat-2 laser Nd:YVO4 amplifier

NASA Astrophysics Data System (ADS)

Sawruk, Nicholas W.; Burns, Patrick M.; Edwards, Ryan E.; Litvinovitch, Viatcheslav; Martin, Nigel; Witt, Greg; Fakhoury, Elias; Iskander, John; Pronko, Mark S.; Troupaki, Elisavet; Bay, Michael M.; He, Charles C.; Wang, Liqin L.; Cavanaugh, John F.; Farrokh, Babak; Salem, Jonathan A.; Baker, Eric

2018-02-01

We report on the cause and corrective actions of three amplifier crystal fractures in the space-qualified laser systems used in NASA Goddard Space Flight Center's (GSFC) Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2). The ICESat-2 lasers each contain three end-pumped Nd:YVOO4 amplifier stages. The crystals are clamped between two gold plated copper heat spreaders with an indium foil thermal interface material, and the crystal fractures occurred after multiple years of storage and over a year of operational run-time. The primary contributors are high compressive loading of the NdYVO4 crystals at the beginning of life, a time dependent crystal stress caused by an intermetallic reaction of the gold plating and indium, and slow crack growth resulting in a reduction in crystal strength over time. An updated crystal mounting scheme was designed, analyzed, fabricated and tested. Thee fracture slab failure analysis, finite-element modeling and corrective actions are presented.

Temperature-dependent spectroscopy and microchip laser operation of Nd:KGd(WO4)2

NASA Astrophysics Data System (ADS)

Loiko, P.; Yoon, S. J.; Serres, J. M.; Mateos, X.; Beecher, S. J.; Birch, R. B.; Savitski, V. G.; Kemp, A. J.; Yumashev, K.; Griebner, U.; Petrov, V.; Aguiló, M.; Díaz, F.; Mackenzie, J. I.

2016-08-01

High-resolution absorption and stimulated-emission cross-section spectra are presented for monoclinic Nd:KGd(WO4)2 (Nd:KGW) laser crystals in the temperature range 77-450 K. At room-temperature, the maximum stimulated emission cross-section is σSE = 21.4 × 10-20 cm2 at 1067.3 nm, for light polarization E || Nm. The lifetime of the 4F3/2 state of Nd3+ in KGW is practically temperature independent at 115 ± 5 μs. Measurement of the energy transfer upconversion parameter for a 3 at.% Nd:KGW crystal proved that this was significantly smaller than for alternative hosts, ∼2.5 × 10-17 cm3/s. When cut along the Ng optical indicatrix axis, the Nd:KGW crystal was configured as a microchip laser, generating ∼4 W of continuous-wave output at 1067 nm with a slope efficiency of 61% under diode-pumping. Using a highly-doped (10 at.%) Nd:KGW crystal, the slope efficiency reached 71% and 74% when pumped with a laser diode and a Ti:Sapphire laser, respectively. The concept of an ultrathin (250 μm) Nd:KGW microchip laser sandwiched between two synthetic diamond heat-spreaders is demonstrated.

The Universal R-Matrix for the Jordanian Deformation of sl(2), and the Contracted Forms of so(4)

NASA Astrophysics Data System (ADS)

Shariati, A.; Aghamohammadi, A.; Khorrami, M.

We introduce a universal R-matrix for the Jordanian deformation of U(sl(2)). Using Uh(so(4))=Uh(sl(2)) ⊕ U-h(sl(2)), we obtain the universal R-matrix for Uh(so(4)). Applying the graded contractions on the universal R-matrix of Uh(so(4)), we show that there exist three distinct R-matrices for all the contracted algebras. It is shown that Uh(sl(2)), Uh(so(4)), and all of these contracted algebras are triangular.

A model structure for identification of linear models of the UH-60 helicopter in hover and forward flight

DOT National Transportation Integrated Search

1995-08-01

A linear model structure applicable to identification of the UH-60 flight : dynamics in hover and forward flight without rotor-state data is developed. The : structure of the model is determined through consideration of the important : dynamic modes ...

34. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

34. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 VIEW OF STAIR FROM REAR (SOUTH) OF HALL, 2nd FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

A neodymium(III)-ammonium complex involving oxalate and carbonate ligands: (NH4)2[Nd2(C2O4)3(CO3)(H2O)].H2O.

PubMed

Trombe, Jean-Christian; Galy, Jean; Enjalbert, Renée

2002-10-01

The title compound, diammonium aqua-mu-carbonato-tri-mu-oxalato-dineodymium(III) hydrate, (NH(4))(2)[Nd(2)(CO(3))(C(2)O(4))(3)(H(2)O)].H(2)O, involving the two ligands oxalate and carbonate, has been prepared hydrothermally as single crystals. The Nd atoms form a tetranuclear unit across the inversion centre at (1/2, 1/2, 1/2). Starting from this tetranuclear unit, the oxalate ligands serve to develop a three-dimensional network. The carbonate group acts as a bis-chelating ligand to two Nd atoms, and is monodentate to a third Nd atom. The oxalate groups are all bis-chelating. The two independent Nd atoms are ninefold coordinated and the coordination polyhedron of these atoms is a distorted monocapped antiprism.

Computation of UH-60A Airloads Using CFD/CSD Coupling on Unstructured Meshes

NASA Technical Reports Server (NTRS)

Biedron, Robert T.; Lee-Rausch, Elizabeth M.

2011-01-01

An unsteady Reynolds-averaged Navier-Stokes solver for unstructured grids is used to compute the rotor airloads on the UH-60A helicopter at high-speed and high thrust conditions. The flow solver is coupled to a rotorcraft comprehensive code in order to account for trim and aeroelastic deflections. Simulations are performed both with and without the fuselage, and the effects of grid resolution, temporal resolution and turbulence model are examined. Computed airloads are compared to flight data.

[Health and environment: the 2nd public health revolution.].

PubMed

Cicolella, André

2010-01-01

As of the mid-19th century, most infectious disease epidemics have been fought and slowed down by taking action on the environment (water, housing, waste) and education. This constitutes the 1st public health revolution paradigm. As we face the current epidemic of chronic diseases and the failure of the dominant biomedical model to stop them, a 2nd public health revolution is needed. The vision for this 2nd public health revolution requires a new paradigm built upon an eco-systemic definition of health and the recognition of the legitimacy for citizen participation based on the precautionary principle.

Synthesis, crystal structure, and magnetic properties of novel intermetallic compounds R2Co2SiC (R = Pr, Nd).

PubMed

Zhou, Sixuan; Mishra, Trinath; Wang, Man; Shatruk, Michael; Cao, Huibo; Latturner, Susan E

2014-06-16

The intermetallic compounds R2Co2SiC (R = Pr, Nd) were prepared from the reaction of silicon and carbon in either Pr/Co or Nd/Co eutectic flux. These phases crystallize with a new stuffed variant of the W2CoB2 structure type in orthorhombic space group Immm with unit cell parameters a = 3.978(4) Å, b = 6.094(5) Å, c = 8.903(8) Å (Z = 2; R1 = 0.0302) for Nd2Co2SiC. Silicon, cobalt, and carbon atoms form two-dimensional flat sheets, which are separated by puckered layers of rare-earth cations. Magnetic susceptibility measurements indicate that the rare earth cations in both analogues order ferromagnetically at low temperature (TC ≈ 12 K for Nd2Co2SiC and TC ≈ 20 K for Pr2Co2SiC). Single-crystal neutron diffraction data for Nd2Co2SiC indicate that Nd moments initially align ferromagnetically along the c axis around ∼12 K, but below 11 K, they tilt slightly away from the c axis, in the ac plane. Electronic structure calculations confirm the lack of spin polarization for Co 3d moments.

PIRLS 2016 Assessment Framework. 2nd Edition

ERIC Educational Resources Information Center

Mullis, Ina V. S., Ed.; Martin, Michael O., Ed.

2015-01-01

The "PIRLS 2016 Assessment Framework, 2nd Edition" provides the foundation for the three international assessments planned as part of the International Association for the Evaluation of Educational Achievement's Progress in International Reading Literacy Study (PIRLS) 2016: PIRLS, PIRLS Literacy, and ePIRLS. PIRLS represents the…

Flight Test Identification and Simulation of a UH-60A Helicopter and Slung Load

NASA Technical Reports Server (NTRS)

Cicolani, Luigi S.; Sahai, Ranjana; Tucker, George E.; McCoy, Allen H.; Tyson, Peter H.; Tischler, Mark B.; Rosen, Aviv

2001-01-01

Helicopter slung-load operations are common in both military and civil contexts. Helicopters and loads are often qualified for these operations by means of flight tests, which can be expensive and time consuming. There is significant potential to reduce such costs both through revisions in flight-test methods and by using validated simulation models. To these ends, flight tests were conducted at Moffett Field to demonstrate the identification of key dynamic parameters during flight tests (aircraft stability margins and handling-qualities parameters, and load pendulum stability), and to accumulate a data base for simulation development and validation. The test aircraft was a UH-60A Black Hawk, and the primary test load was an instrumented 8- by 6- by 6-ft cargo container. Tests were focused on the lateral and longitudinal axes, which are the axes most affected by the load pendulum modes in the frequency range of interest for handling qualities; tests were conducted at airspeeds from hover to 80 knots. Using telemetered data, the dynamic parameters were evaluated in near real time after each test airspeed and before clearing the aircraft to the next test point. These computations were completed in under 1 min. A simulation model was implemented by integrating an advanced model of the UH-60A aerodynamics, dynamic equations for the two-body slung-load system, and load static aerodynamics obtained from wind-tunnel measurements. Comparisons with flight data for the helicopter alone and with a slung load showed good overall agreement for all parameters and test points; however, unmodeled secondary dynamic losses around 2 Hz were found in the helicopter model and they resulted in conservative stability margin estimates.

UH-1 Helicopter Mechanic (MOS 67N20) Job Description Survey: Performance of Specific Maintenance Tasks.

ERIC Educational Resources Information Center

Schulz, Russel E.; And Others

The report is the second of two describing the results of a world-wide survey of the maintenance activities of UH-1 helicopter mechanics for the purpose of studying the relationships among job requirements, training, and manpower considerations for aviation maintenance. A summary of the results of the first report is included. The survey…

UH-1 Helicopter Mechanic (MOS 67N20) Job Description Survey: Background, Training, and General Maintenance Activities.

ERIC Educational Resources Information Center

Schulz, Russel E.; And Others

The report, the first of two documents examining the relationship among job requirements, training, and manpower considerations for Army aviation maintenance Personnel, discusses the development of task data gathering techniques and procedures for incorporating this data into training programs for the UH-1 helicopter mechanic sPecialty (MOS…

Fidelity assessment of a UH-60A simulation on the NASA Ames vertical motion simulator

NASA Technical Reports Server (NTRS)

Atencio, Adolph, Jr.

1993-01-01

Helicopter handling qualities research requires that a ground-based simulation be a high-fidelity representation of the actual helicopter, especially over the frequency range of the investigation. This experiment was performed to assess the current capability to simulate the UH-60A Black Hawk helicopter on the Vertical Motion Simulator (VMS) at NASA Ames, to develop a methodology for assessing the fidelity of a simulation, and to find the causes for lack of fidelity. The approach used was to compare the simulation to the flight vehicle for a series of tasks performed in flight and in the simulator. The results show that subjective handling qualities ratings from flight to simulator overlap, and the mathematical model matches the UH-60A helicopter very well over the range of frequencies critical to handling qualities evaluation. Pilot comments, however, indicate a need for improvement in the perceptual fidelity of the simulation in the areas of motion and visual cuing. The methodology used to make the fidelity assessment proved useful in showing differences in pilot work load and strategy, but additional work is needed to refine objective methods for determining causes of lack of fidelity.

Combination of CO2 and Q-switched Nd:YAG lasers is more effective than Q-switched Nd:YAG laser alone for eyebrow tattoo removal.

PubMed

Radmanesh, Mohammad; Rafiei, Zohreh

2015-04-01

The eyebrow tattoo removal using Q-switched lasers is usually prolonged. Other modalities may be required to enhance the efficacy and shorten the treatment course. To compare the efficacy of Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser alone versus combination of Q-switched Nd:YAG and Ultrapulse CO2 lasers for eyebrow tattoo removal after a single session. After local anesthesia, the right eyebrow of 20 patients was treated with Ultrapulse CO2 laser with the parameters of 4 J/cm(2) and 3.2 J/cm(2) for the first and the second passes. Both eyebrows were then treated with 1064-nm and 532-nm Q-switched Nd:YAG laser. The spot size and pulse duration were 3 mm and 5 nanoseconds for both wavelengths, and the fluence was 7 J/cm(2) for 1064 nm and 3 J/cm (2) for 532 nm. The side treated with combination of Q-switched Nd:YAG and CO2 lasers improved 75-100% in 6 of 20 patients versus only 1 of 20 in the side treated with Q-switched Nd:YAG alone. Similarly, the right side in 13 of 20 patients showed more than 50% improvement with combination therapy versus the left side (the monotherapy side), where only 6 of 20 cases showed more than 50% improvement. The Mann-Whitney test was 2.85 for the right side and 1.95 for the left side (P value = 0.007). Using Ultra pulse CO2 laser enhances the efficacy of Q-switched Nd:YAG laser in eyebrow tattoo removal.

Lattice Parameter Behavior with Different Nd and O Concentrations in (U 1-yNd y)O 2±x Solid Solution

DOE PAGES

Lee, Seung Min; Knight, Travis W.; Voit, Stwart L.; ...

2016-02-02

The solid solution of (U1-yFPy)O- 2±x, has the same fluorite structure as UO 2±x lambda, and the lattice parameter is affected by dissolved fission product and oxygen concentrations. We investigated the relation between the lattice parameter and the concentrations of neodymium and oxygen in the fluorite structure of (U 1-yNd y)O 2±x using X-ray diffraction. Moreover, the lattice parameter behavior in the (U 1-yNd y)O 2±x, solid solution shows a linear change as a function of the oxygen-to-metal ratio and solubility of neodymium. The lattice parameter depends on the radii of ions forming the fluorite structure and also can bemore » expressed by a particular rule (modified Vegard's law). Furthermore, the numerical analyses of the lattice parameters for the stoichiometric and nonstoichionietric solid solutions were conducted, and the lattice parameter model for the (U1-yNdy)O 2±x, solid solution was assessed. There is a very linear relationship between the lattice parameter and the Nd and O concentration for the stoichiometry and nonstoichiometry of the (U 1-yNd y)O 2±x solid solution was verified.« less

Cation and Vacancy Disorder in U 1-yNd yO 2.00-X Alloys

DOE PAGES

Barabash, Rozaliya I.; Voit, Stewart L.; Aidhy, Dilpuneet S.; ...

2015-09-14

In this study, the intermixing and clustering of U/Nd, O, and vacancies were studied by both laboratory and synchrotron-based x-ray diffraction in U 1-yNd yO 2-X alloys. It was found that an increased holding time at the high experimental temperature during initial alloy preparation results in a lower disorder of the Nd distribution in the alloys. Adjustment of the oxygen concentration in the U 1-yNd yO 2-X alloys with different Nd concentrations was accompanied by the formation of vacancies on the oxygen sublattice and a nanocrystalline component. The lattice parameters in the U 1-yNd yO 2-X alloys were also foundmore » to deviate significantly from Vegard's law when the Nd concentration was high (53%) and decreased with increasing oxygen concentration. Such changes indicate the formation of large vacancy concentrations during oxygen adjustment at these high temperatures. Finally, the change in the vacancy concentration after the oxygen adjustment was estimated relative to Nd concentration and oxygen stoichiometry.« less

Nd2Fe14C-based magnet with better permanent magnetic properties prepared by a simple mechanochemical method

NASA Astrophysics Data System (ADS)

Geng, Hongmin; Ji, Yuan; Zhang, Jingjing; Gao, Yuchao; Yan, Yu; Wang, Wenquan; Su, Feng; Du, Xiaobo

2017-11-01

Nd2Fe14C-based magnet is prepared by a mechanochemical method, namely high-energy ball-milling Nd2Fe11Bx (x = 0-0.15) alloy in heptane (C7H16), followed by annealing to 850 °C in vacuum. Under the action of high-energy ball-milling, Nd2Fe11Bx react with heptane to form NdH2+δ, Fe-(CB), C, etc. H2 is released and Nd2Fe17, Nd2Fe17Cx (x = 0-3), Nd2Fe14C, Nd carbides and α-Fe are formed in the subsequent annealing. C amount depends on ball-milling time t. Long time ball milling or high C content suppresses the formation of 2:17 phase and favors the formation of 2:14:1 phase in the final products. Excessive ball-milling results in the quick increase of α-Fe. The maximum of magnetically hard Nd2Fe14C is obtained at t = 4 h. For Nd2Fe11 samples, there exists considerable quantity of Nd carbides and α-Fe phase appears earlier and increases rapidly with extending the ball-milling time t. The addition of B element shortens the ball-milling time of the formation of maximum Nd2Fe14C and prominently suppresses the formation of Nd carbide and α-Fe. The optimum magnetic properties, coercivity iHc of 1193.7 kA/m, remanence Mr of 580.9 kA/m, maximum magnetic energy product (BH)max of 91.7 kJ/m3 is approaching to its theoretic value of 99.2 kJ/m3 for isotropic Nd2Fe14C magnet, are obtained in Nd2Fe11B0.06 alloy ball milled for 3.5 h.

Selective Extraction and Recovery of Nd and Dy from Nd-Fe-B Magnet Scrap by Utilizing Molten MgCl2

NASA Astrophysics Data System (ADS)

Shirayama, Sakae; Okabe, Toru H.

2018-06-01

Fundamental experiments are conducted with the aim of developing an efficient recycling process for rare earth elements (REEs) from neodymium-iron-boron (Nd-Fe-B) permanent magnet scrap. Molten magnesium dichloride (MgCl2) was chosen as an extraction medium, which can selectively chlorinate and extract REEs in magnet alloys. Dysprosium-containing Nd-Fe-B magnet alloy was immersed in molten MgCl2 at 1273 K (1000 °C) for 3 to 12 hours. The results of the experiments clearly show that the REEs in the magnetic alloy were successfully extracted into the molten salt, while the Fe-B alloy remained in a solid form. The extraction ratios of Nd and Dy were at most 87 and 78 mass pct, respectively. After the extraction experiment, excess MgCl2 and Mg were removed by vacuum distillation and the rare earth chlorides were recovered. Thus, the feasibility of this method for efficient recovery of rare earths using molten MgCl2 is demonstrated.

Selective Extraction and Recovery of Nd and Dy from Nd-Fe-B Magnet Scrap by Utilizing Molten MgCl2

NASA Astrophysics Data System (ADS)

Shirayama, Sakae; Okabe, Toru H.

2018-02-01

Fundamental experiments are conducted with the aim of developing an efficient recycling process for rare earth elements (REEs) from neodymium-iron-boron (Nd-Fe-B) permanent magnet scrap. Molten magnesium dichloride (MgCl2) was chosen as an extraction medium, which can selectively chlorinate and extract REEs in magnet alloys. Dysprosium-containing Nd-Fe-B magnet alloy was immersed in molten MgCl2 at 1273 K (1000 °C) for 3 to 12 hours. The results of the experiments clearly show that the REEs in the magnetic alloy were successfully extracted into the molten salt, while the Fe-B alloy remained in a solid form. The extraction ratios of Nd and Dy were at most 87 and 78 mass pct, respectively. After the extraction experiment, excess MgCl2 and Mg were removed by vacuum distillation and the rare earth chlorides were recovered. Thus, the feasibility of this method for efficient recovery of rare earths using molten MgCl2 is demonstrated.

Medium-power diode-pumped Nd:BaY2F8 laser

NASA Astrophysics Data System (ADS)

Agnesi, Antonio; Guandalini, Annalisa; Lucca, Andrea; Sani, Elisa; Toncelli, Alessandra; Tonelli, Mauro; dell'Acqua, Stefano

2003-05-01

We report what is to our knowledge the first Nd:BaY2F8 (Nd:BaYF) laser pumped with a multiwatt fiber-coupled diode array tuned at approximately 804 nm. As much as 2.4 W were obtained with 6.2 W of absorbed pump power, showing efficient operation (51% slope efficiency), excellent beam quality (M2=1.1), and weak thermal lensing. Small intracavity losses (<1%) were measured, indicating both reduced thermally induced aberrations and good optical quality of the laser crystal.

1st- and 2nd-order motion and texture resolution in central and peripheral vision

NASA Technical Reports Server (NTRS)

Solomon, J. A.; Sperling, G.

1995-01-01

STIMULI. The 1st-order stimuli are moving sine gratings. The 2nd-order stimuli are fields of static visual texture, whose contrasts are modulated by moving sine gratings. Neither the spatial slant (orientation) nor the direction of motion of these 2nd-order (microbalanced) stimuli can be detected by a Fourier analysis; they are invisible to Reichardt and motion-energy detectors. METHOD. For these dynamic stimuli, when presented both centrally and in an annular window extending from 8 to 10 deg in eccentricity, we measured the highest spatial frequency for which discrimination between +/- 45 deg texture slants and discrimination between opposite directions of motion were each possible. RESULTS. For sufficiently low spatial frequencies, slant and direction can be discriminated in both central and peripheral vision, for both 1st- and for 2nd-order stimuli. For both 1st- and 2nd-order stimuli, at both retinal locations, slant discrimination is possible at higher spatial frequencies than direction discrimination. For both 1st- and 2nd-order stimuli, motion resolution decreases 2-3 times more rapidly with eccentricity than does texture resolution. CONCLUSIONS. (1) 1st- and 2nd-order motion scale similarly with eccentricity. (2) 1st- and 2nd-order texture scale similarly with eccentricity. (3) The central/peripheral resolution fall-off is 2-3 times greater for motion than for texture.

ET-26 hydrochloride (ET-26 HCl) has similar hemodynamic stability to that of etomidate in normal and uncontrolled hemorrhagic shock (UHS) rats.

PubMed

Wang, Bin; Chen, Shouming; Yang, Jun; Yang, Linghui; Liu, Jin; Zhang, Wensheng

2017-01-01

ET-26 HCl is a promising sedative-hypnotic anesthetic with virtually no effect on adrenocortical steroid synthesis. However, whether or not ET-26 HCl also has a sufficiently wide safety margin and hemodynamic stability similar to that of etomidate and related compounds remains unknown. In this study, the effects of ET-26 HCl, etomidate and propofol on therapeutic index, heart rate (HR), mean arterial pressure (MAP), maximal rate for left ventricular pressure rise (Dmax/t), and maximal rate for left ventricular pressure decline (Dmin/t) were investigated in healthy rats and a rat model of uncontrolled hemorrhagic shock (UHS). 50% effective dose (ED50) and 50% lethal dose (LD50) were determined after single bolus doses of propofol, etomidate, or ET-26 HCl using the Bliss method and the up and down method, respectively. All rats were divided into either the normal group and received either etomidate, ET-26 HCl or propofol, (n = 6 per group) or the UHS group and received either etomidate, ET-26 HCl or propofol, (n = 6 per group). In the normal group, after preparation for hemodynamic and heart-function monitoring, rats were administered a dose of one of the test agents twofold-higher than the established ED50, followed by hemodynamic and heart-function monitoring. Rats in the UHS group underwent experimentally induced UHS with a target arterial pressure of 40 mmHg for 1 hour, followed by administration of an ED50 dose of one of the experimental agents. Blood-gas analysis was conducted on samples obtained during equilibration with the experimental setup and at the end of the experiment. In the normal group, no significant differences in HR, MAP, Dmax/t and Dmin/t (all P > 0.05) were observed at any time point between the etomidate and ET-26 HCl groups, whereas HR, MAP and Dmax/t decreased briefly and Dmin/t increased following propofol administration. In the UHS group, no significant differences in HR, MAP, Dmax/t and Dmin/t were observed before and after administration

Physical properties of nanoparticles Nd added Bi1.7Pb0.3Sr2Ca2Cu3Oy superconductors

NASA Astrophysics Data System (ADS)

Abbas, Muna; Abdulridha, Ali; Jassim, Amal; Hashim, Fouad

2018-05-01

Bi1.7Pb0.3Sr2Ca2Cu3Oy bulks were synthesized, with the addition of Nd2O3 nanoparticles, by the solid state reaction method. The concentrations of Nd were varied from 0.1 to 0.6. The superconducting properties of the samples were investigated and studied to determine the influence of Nd2O3 addition on superconducting properties and microstructural development. The structural characteristics of the synthesized superconductor samples were carried out through X-ray diffractions. DC Four point probe method was used to study the electrical resistivity behavior and to evaluate the transition temperature (TC) for all samples. It was found that: 0.2 weight percentage of Nd2O3 yield the highest TC 123 K for highest volume fraction of 2223-phase, while excessive addition decreased both of them. The results point to compelling indications of correlations between charge carriers and superconductivity. Energy-dispersive X-ray spectroscopy (EDX) analysis for Bi1.7Pb0.3Nd0.2Sr2Ca2Cu3Oy superconductor shows that Nd may be substituted at Ca sites creating point defects, which act as flux pinning centers. Scanning electron microscopy (SEM) was employed to examine the microstructure of some samples. Their results showed precipitation of Nd nanoparticles on the surface as plate-like grains.

Chemical separation of Nd from geological samples for chronological studies using (146)Sm-(142)Nd and (147)Sm-(143)Nd systematics.

PubMed

Kagami, Saya; Yokoyama, Tetsuya

2016-09-21

Sm-Nd dating, which involves long-lived (147)Sm-(143)Nd and short-lived (146)Sm-(142)Nd systematics, has been widely used in the field of geosciences. To obtain precise and accurate ages of geological samples, the determination of highly precise Nd isotope ratios with nearly complete removal of Ce and Sm is indispensable to avoid mass spectral interference. In this study, we developed a three-step column chemistry procedure for separating Nd from geological samples that includes cation exchange chromatography for separating major elements from rare earth elements (REEs), oxidative extraction chromatography using Ln Resin coupled with HNO3 + KBrO3 for separating tetravalent Ce from the remaining REEs, and final purification of Nd using Ln Resin. This method enables high recovery of Nd (>91%) with effective separation of Nd from Ce and Sm (Ce/Nd < 1.2 × 10(-5) and Sm/Nd < 5.2 × 10(-6)). In addition, we devised a new method for determining Sm/Nd ratios with the isotope dilution inductively coupled plasma mass spectrometry method using (145)Nd- and (149)Sm-enriched spikes coupled with a group separation of REEs using TRU Resin. Applying the techniques developed in this study, we determined the Sm-Nd whole-rock isochron age of basaltic eucrites, yielding 4577 - 88(+ 55) Ma and 4558 ± 300 Ma for (146)Sm-(142)Nd and (147)Sm-(143)Nd systematics, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Frustrated ground state in the metallic Ising antiferromagnet Nd2Ni2In

NASA Astrophysics Data System (ADS)

Sala, G.; Mašková, S.; Stone, M. B.

2017-10-01

We used inelastic neutron scattering measurements to examine the intermetallic Ising antiferromagnet Nd2Ni2In . The dynamical structure factor displays a spectrum with multiple crystal field excitations. These crystal field excitations consist of a set of four transitions covering a range of energies between 4 and 80 meV. The spectrum is very sensitive to the temperature, and we observed a softening and a shift in the energies above the transition temperature of the system. The analysis of the crystalline electric field scheme confirms the Ising nature of the spins and their orientation as proposed by previous studies. We characterized Nd2Ni2In as a large moment intermetallic antiferromagnet with the potential to support a geometrically frustrated Shastry-Sutherland lattice.

Evaluation of Wind Tunnel and Scaling Effects with the UH-60A Airloads Rotor

DTIC Science & Technology

2011-05-01

V! free-stream velocity, ft/s x chordwise distance from leading edge, ft #c, #s corrected/geometric shaft angles, deg $1c, $1s cos/sin components...attached to spindles that were retained by elastomeric bearings to a one-piece titanium hub. These bearings permitted blade flap, lead-lag, and...Figure 3. UH-60A small-scale rotor installed in DNW. Main rotor dampers were installed between each of the main rotor spindles and the hub to

Creating and maintaining a successful geoscience pathway from 2YC to 4YC for Native Hawaiian Students: First Steps

NASA Astrophysics Data System (ADS)

Guidry, M.; Eschenberg, A.; McCoy, F. W.; McManus, M. A.; Lee, K.; DeLay, J. K.; Taylor, S. V.; Dire, J.; Krupp, D.

2017-12-01

In the Fall of 2015, the two four year (4YC) institutions within the University of Hawaii (UH) system offering baccalaureate degrees in geosciences enrolled only six Native Hawaiian (NH) students out of a total of 194 students in geoscience degree programs. This percentage (3%) of NH students enrolled in geosciences is far lower than the percentage of NH students enrolled at any single institution in the UH system, which ranges from 14 to 42%. At the same time, only six (3%) of the 194 students enrolled in geoscience baccalaureate programs were transfer students from the UH community colleges. Of these six transfer students, three were NH. This reflects the need for increased transfer of NH in the geosciences from two year (2YC) to 4YC. In the Fall of 2015, UH Manoa's (UHM) School of Ocean and Earth Science and Technology (SOEST) accounted for only 0.14% of transfer students from UH community colleges. This compares to 5% in the UHM School of Engineering and 27% in the UHM College of Arts and Sciences. As part of the first year of a multi-institutional five-year NSF TCUP-PAGE (Tribal Colleges and Universities Program - PArtnerships for Geoscience Education) award, we review our first steps and strategies for building a successful and sustainable geoscience transfer pathway for Native Hawaiian and community college students into the three undergraduate geoscience programs (Atmospheric Sciences, Environmental Sciences, and Geology & Geophysics) within SOEST.

"Uh," "Um," and Autism: Filler Disfluencies as Pragmatic Markers in Adolescents with Optimal Outcomes from Autism Spectrum Disorder

ERIC Educational Resources Information Center

Irvine, Christina A.; Eigsti, Inge-Marie; Fein, Deborah A.

2016-01-01

Filler disfluencies--"uh" and "um"--are thought to serve distinct discourse functions. We examined fillers in spontaneous speech by youth with autism spectrum disorder (ASD), who struggle with pragmatic language, and by youth with ASD who have achieved an "optimal outcome" (OO), as well as in peers with typical…

Structural and magnetic investigations of single-crystalline neodymium zirconate pyrochlore Nd2Zr2O7

NASA Astrophysics Data System (ADS)

Hatnean, M. Ciomaga; Lees, M. R.; Petrenko, O. A.; Keeble, D. S.; Balakrishnan, G.; Gutmann, M. J.; Klekovkina, V. V.; Malkin, B. Z.

2015-05-01

We report structural and magnetic properties studies of large high-quality single crystals of the frustrated magnet Nd2Zr2O7 . Powder x-ray diffraction analysis confirms that Nd2Zr2O7 adopts the pyrochlore structure. Room-temperature x-ray diffraction and time-of-flight neutron-scattering experiments show that the crystals are stoichiometric in composition with no measurable site disorder. The temperature dependence of the magnetic susceptibility shows no magnetic ordering at temperatures down to 0.5 K. Fits to the magnetic susceptibility data using a Curie-Weiss law reveal a ferromagnetic coupling between the Nd moments. Magnetization versus field measurements show a local Ising anisotropy along the <111 > axes of the Nd3 + ions in the ground state. Specific heat versus temperature measurements in zero applied magnetic field indicate the presence of a thermal anomaly below T ˜7 K, but no evidence of magnetic ordering is observed down to 0.5 K. The experimental temperature dependence of the single-crystal bulk dc susceptibility and isothermal magnetization are analyzed using crystal field theory and the crystal field parameters and exchange coupling constants determined.

Laser and thermal properties of Nd:YGd2Sc2Al2GaO12 garnet ceramic Laser and thermal properties of Nd:YSGG garnet ceramic

NASA Astrophysics Data System (ADS)

Brenier, A.; Alombert-Goget, G.; Guyot, Y.; Boulon, G.

2012-10-01

The absorption and fluorescence properties of the Nd-doped YGd2Sc2Al2GaO12 mixed garnet ceramics have been measured at different temperatures. Under laser diode pumping an efficient laser emission has been demonstrated with 45% slope efficiency. The emission is constituted by two lines at 1058.6 and 1061.3 nm, subjected to a red shift and a variable relative intensity versus pump power. The role of the temperature has been investigated playing with the cavity parameters. The thermal conductivity of the 1% Nd-doped material has been determined (3.2 W/m/K) measuring the radial temperature distribution of the exit face of the sample including the axial heat flow in the analysis. The M2 beam quality factor and the dioptric power of the thermal lens have been investigated versus the pump power. The thermo-optic coefficient χ was determined as 44.4×10-6 K-1.

Accelerated Testing of UH-60 Viscous Bearings for Degraded Grease Fault

NASA Technical Reports Server (NTRS)

Dykas, Brian; Hood, Adrian; Krantz, Timothy; Klemmer, Marko

2015-01-01

An accelerated aging investigation of critical aviation bearings lubricated with MIL-PRF- 81322 grease was conducted to derive an understanding of the mechanisms of grease degradation and loss of lubrication over time. The current study focuses on UH-60 Black Hawk viscous damper bearings supporting the tail rotor driveshaft, which were subjected to more than 5800 hours of testing in a heated environment to accelerate the deterioration of the grease. The mechanism of grease degradation is a reduction in the oil/thickener ratio rather than the expected chemical degradation of grease constituents. Over the course of testing, vibration and temperature monitoring of bearings was conducted and trends for failing bearings are presented.

Fluctuations and All-In-All-Out Ordering in Dipole-Octupole Nd2Zr2O7

NASA Astrophysics Data System (ADS)

Lhotel, E.; Petit, S.; Guitteny, S.; Florea, O.; Ciomaga Hatnean, M.; Colin, C.; Ressouche, E.; Lees, M. R.; Balakrishnan, G.

2015-11-01

By means of neutron scattering and magnetization measurements down to 90 mK, we determine the magnetic ground state of the spin-ice candidate Nd2Zr2O7. We show that, despite ferromagnetic interactions, Nd2Zr2O7 undergoes a transition around 285 mK towards an all-in-all-out antiferromagnetic state, with a strongly reduced ordered magnetic moment. We establish the (H ,T ) phase diagram in the three directions of the applied field and reveal a metamagnetic transition around 0.1 T, associated with an unexpected shape of the magnetization curves. We propose that this behavior results from the peculiar nature of the Nd3 + doublet, a dipolar-octupolar doublet, different from the standard Kramers doublet studied to date, thus revealing the importance of multipolar correlations in the properties of pyrochlore oxides.

Structure and magnetic properties of Nd2Fe14B fine particles produced by spark erosion

NASA Astrophysics Data System (ADS)

Wan, H.; Berkowitz, A. E.

1994-11-01

At present Nd2Fe14B is the best permanent magnet because of its extremely high coercivity and energy product. Optimum properties of Nd2Fe14B magnets can be attained by producing single domain particles, and then aligning and compacting them. Due to the reactivity of the Nd constitutent, it is challenging to produce and handle a large amount of fine particles of this material. We have prepared fine particles of Nd2Fe14B by spark erosion with various dielectric media. Yield, size, size distribution, structure, and magnetic properties are discussed. The Nd2Fe14B particles were made by the sharker pot spark erosion method. Relaxation oscillators or a pulse generator were used to power the park erosion. Commercial Neomax 35 was employed as the primary material. The dielectric media were liquid Ar, Ar gas, and hydrocarbons, which provided an oxygen free environment. Structure and size were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and x-ray diffraction. Magnetic properties were measured by vibrating sample magnetometer (VSM) with temperatures in range of 4.2-1200 K. The particles produced in these three different dielectric media had different microstructures and crystal structures. The particles made in Ar gas were pure Nd2Fe14B phase. The particles made in liquid Ar were a mixture of amorphous and crystalline Nd2Fe14B, because the liquid Ar provided a much higher quench rate than Ar gas, which produced some amorphous Nd2Fe14B. Upon annealing, the amorphous particles became crystalline. The fine particles produced in hydrocarbons, such as pentane and dodecane, had more complex mixed phases, since the rare earth reacted with the hydrocarbons during the sparking process. The phases were NdC2, alpha-Fe, and amorphous and crystalline Nd2Fe14B. The effects of power parameters, such as voltage and capacitance, on particle size were investigated. Particle sizes from 20 nm to 50 microns were obtained. Nd2Fe14B

Grain boundary diffusion behaviors in hot-deformed Nd2Fe14B magnets by PrNd-Cu low eutectic alloys

NASA Astrophysics Data System (ADS)

Tang, Xu; Chen, Renjie; Li, Ming; Jin, Chaoxiang; Yin, Wenzong; Lee, Don; Yan, Aru

2018-01-01

High coercivity of hot-deformed Nd2Fe14B magnets was obtained by grain boundary diffusion. Comparable squareness and similar magnetic properties for samples diffusing from side and pole surfaces show little discrepancies if quantities of the infiltrated PrNd-Cu low eutectic alloys is enough to obtain sufficient diffusion. However, the microstructures and higher characteristic peak ratios show preferable orientation of grains near surfaces of the sample diffused from side surfaces than that from pole surfaces. Amorphous Nd-rich phases and crystal Fe-rich phases were both observed in the diffused magnets. The enhancement of coercivity is considered to be resulted from grain boundary optimization and magnetic isolation which is caused by the thickened nonmagnetic intergranular phases.

A Channelized 2nd IF/LO Downconverter for the E0S Microwave Limb Sounder

NASA Technical Reports Server (NTRS)

LaBelle, Remi C.

2003-01-01

The Earth Observing System (EOS) Microwave Limb Sounder (MLS) is scheduled for launch in 2004 on the EOS Aura spacecraft. The design, assembly and test of the flight 2nd Intermediate Frequency/ Local Oscillator (2nd IF/LO) subsystem for this instrument has been completed and is presented here. The 2nd IF/LO subsystem consists of 5 separate microwave assemblies, 1 for each of the 5 millimeter wave radiometer front ends, providing a total of 33 separate IF channels. Some key requirements of the subsystem are as follows: provide frequency multiplexing of overlapping or closely spaced 1st IF channels while maintaining low ripple in the passbands; generate 19 different 2nd LO frequencies, in the range of 4-20 GHz, with low phase noise and a placement resolution of 400 KHz; downconvert the 1st IF's to a common 2nd IF frequency centered at 900 MHz; minimize cost and schedule by using common designs for the 5 different assemblies wherever possible.

Magnetic structure of the mixed antiferromagnet NdMn0.8Fe0.2O3

NASA Astrophysics Data System (ADS)

Mihalik, Matúš; Mihalik, Marián; Hoser, Andreas; Pajerowski, Daniel M.; Kriegner, Dominik; Legut, Dominik; Lebecki, Kristof M.; Vavra, Martin; Fitta, Magdalena; Meisel, Mark W.

2017-10-01

The magnetic structure of the mixed antiferromagnet NdMn0.8Fe0.2O3 was resolved. Neutron powder diffraction data definitively resolve the Mn sublattice with a magnetic propagation vector k =(000 ) and with the magnetic structure (Ax,Fy,Gz ) for 1.6 K Nd sublattice has a (0 ,fy,0 ) contribution in the same temperature interval. The Mn sublattice undergoes a spin-reorientation transition at T1≈13 K while the Nd magnetic moment abruptly increases at this temperature. Powder x-ray diffraction shows a strong magnetoelastic effect at TN but no additional structural phase transitions from 3 to 300 K. Density functional theory calculations confirm the magnetic structure of the undoped NdMnO3 as part of our analysis. Taken together, these results show that the magnetic structure of the Mn sublattice in NdMn0.8Fe0.2O3 is a combination of the Mn and Fe parent compounds, but the magnetic ordering of the Nd sublattice spans a broader temperature interval than in the case of NdMnO3 and NdFeO3. This result is a consequence of the fact that the Nd ions do not order independently, but via polarization from the Mn/Fe sublattice.

Book Review: Bioassays with Arthropods: 2nd Edition

USDA-ARS?s Scientific Manuscript database

The technical book "Bioassays with Arthropods: 2nd Edition" (2007. Jacqueline L. Robertson, Robert M. Russell, Haiganoush K, Preisler and N. E. Nevin, Eds. CRC Press, Boca Raton, FL, 224 pp.) was reviewed for the scientific readership of the peer-reviewed publication Journal of Economic Entomology. ...

Single-crystal and textured polycrystalline Nd2Fe14B flakes with a submicron or nanosize thickness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, BZ; Zheng, LY; Li, WF

2012-02-01

This paper reports on the fabrication, structure and magnetic property optimization of Nd2Fe14B single-crystal and [0 0 1] textured poly-nanocrystalline flakes prepared by surfactant-assisted high-energy ball milling (HEBM). Single-crystal Nd2Fe14B flakes first with micron and then with submicron thicknesses were formed via continuous basal cleavage along the (1 1 0) planes of the irregularly shaped single-crystal microparticles during the early stage of HEBM. With further milling, [0 0 1] textured polycrystalline submicron Nd2Fe14B flakes were formed. Finally, crystallographically anisotropic polycrystalline Nd2Fe14B nanoflakes were formed after milling for 5-6 h. Anisotropic magnetic behavior was found in all of the flake samples.more » Nd2Fe14B flakes prepared with either oleic acid (OA) or oleylamine (OY) as the surfactant exhibited similar morphology, structure and magnetic properties. Both the addition of some low-melting-point eutectic Nd70Cu30 alloy and an appropriate post-annealing can increase the coercivity of the Nd2Fe14B flakes. The coercivity of Nd2Fe14B nanoflakes with an addition of 16.7 wt.% Nd70Cu30 by milling for 5 h in heptane with 20 wt.% OY increased from 3.7 to 6.8 kOe after annealing at 450 degrees C for 0.5 h. The mechanism for formation and coercivity enhancement of Nd2Fe14B single-crystal and textured poly-nanocrystalline flakes with a submicron or nanosize thickness was discussed. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.« less

15. Front security entrance to the perimeter acquisition radar building, ...

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

15. Front security entrance to the perimeter acquisition radar building, showing rotogates 1 and 2 and entrance door to security operations control center (SOCC), room #108 - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Investigation on demagnetization of Nd2Fe14B permanent magnets induced by irradiation

NASA Astrophysics Data System (ADS)

Li, Zhefu; Jia, Yanyan; Liu, Renduo; Xu, Yuhai; Wang, Guanghong; Xia, Xiaobin

2017-12-01

Nd2Fe14B is an important component of insertion devices, which are used in synchrotron radiation sources, and could be demagnetized by irradiation. In the present study, the Monte Carlo code FLUKA was used to analyze the irradiation field of Nd2Fe14B, and it was confirmed that the main demagnetization particle was neutron. Nd2Fe14B permanent magnet samples were irradiated by Ar ions at different doses to simulate neutron irradiation damage. The hysteresis loops were measured using a vibrating sample magnetometer, and the microstructure evolutions were characterized by transmission electron microscopy. Moreover, the relationship between them was discussed. The results indicate that the decrease in saturated magnetization is caused by the changes in microstructure. The evolution of single crystals into an amorphous structure is the reason for the demagnetization phenomenon of Nd2Fe14B permanent magnets when considering its microscopic structure.

A failure effects simulation of a low authority flight control augmentation system on a UH-1H helicopter

NASA Technical Reports Server (NTRS)

Corliss, L. D.; Talbot, P. D.

1977-01-01

A two-pilot moving base simulator experiment was conducted to assess the effects of servo failures of a flight control system on the transient dynamics of a Bell UH-1H helicopter. The flight control hardware considered was part of the V/STOLAND system built with control authorities of from 20-40%. Servo hardover and oscillatory failures were simulated in each control axis. Measurements were made to determine the adequacy of the failure monitoring system time delay and the servo center and lock time constant, the pilot reaction times, and the altitude and attitude excursions of the helicopter at hover and 60 knots. Safe recoveries were made from all failures under VFR conditions. Pilot reaction times were from 0.5 to 0.75 sec. Reduction of monitor delay times below these values resulted in significantly reduced excursion envelopes. A subsequent flight test was conducted on a UH-1H helicopter with the V/STOLAND system installed. Series servo hardovers were introduced in hover and at 60 knots straight and level. Data from these tests are included for comparison.

Hydrazinium lanthanide oxalates: synthesis, structure and thermal reactivity of N2H5[Ln2(C2O4)4(N2H5)]·4H2O, Ln = Ce, Nd.

PubMed

De Almeida, Lucie; Grandjean, Stéphane; Rivenet, Murielle; Patisson, Fabrice; Abraham, Francis

2014-03-28

New hydrazinium lanthanide oxalates N2H5[Ln2(C2O4)4(N2H5)]·4H2O, Ln = Ce (Ce-HyOx) and Nd (Nd-HyOx), were synthesized by hydrothermal reaction at 150 °C between lanthanide nitrate, oxalic acid and hydrazine solutions. The structure of the Nd compound was determined from single-crystal X-ray diffraction data, space group P2₁/c with a = 16.315(4), b = 12.127(3), c = 11.430(2) Å, β = 116.638(4)°, V = 2021.4(7) Å(3), Z = 4, and R1 = 0.0313 for 4231 independent reflections. Two distinct neodymium polyhedra are formed, NdO9 and NdO8N, an oxygen of one monodentate oxalate in the former being replaced by a nitrogen atom of a coordinated hydrazinium ion in the latter. The infrared absorption band at 1005 cm(-1) confirms the coordination of N2H5(+) to the metal. These polyhedra are connected through μ2 and μ3 oxalate ions to form an anionic three-dimensional neodymium-oxalate arrangement. A non-coordinated charge-compensating hydrazinium ion occupies, with water molecules, the resulting tunnels. The N-N stretching frequencies of the infrared spectra demonstrate the existence of the two types of hydrazine ions. Thermal reactivity of these hydrazinium oxalates and of the mixed isotypic Ce/Nd (CeNd-HyOx) oxalate were studied by using thermogravimetric and differential thermal analyses coupled with gas analyzers, and high temperature X-ray diffraction. Under air, fine particles of CeO2 and Ce(0.5)Nd(0.5)O(1.75) are formed at low temperature from Ce-HyOx and CeNd-HyOx, respectively, thanks to a decomposition/oxidation process. Under argon flow, dioxymonocyanamides Ln2O2CN2 are formed.

Magnetic structure of the mixed antiferromagnet NdMn 0.8 Fe 0.2 O 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihalik, Matus; Mihalik, Marian; Hoser, Andreas

The magnetic structure of the mixed antiferromagnet NdMn 0.8Fe 0.2O 3 was resolved. Neutron powder diffraction data definitively resolve the Mn sublattice with a magnetic propagation vector k=(000) and with the magnetic structure (A x, F y, G z) for 1.6 K N(≈ 59 K). The Nd sublattice has a (0, f y, 0) contribution in the same temperature interval. The Mn sublattice undergoes a spin-reorientation transition at T 1 ≈ 13 K while the Nd magnetic moment abruptly increases at this temperature. Powder x-ray diffraction shows a strong magnetoelastic effect at T N but no additional structural phase transitionsmore » from 3 to 300 K. Density functional theory calculations confirm the magnetic structure of the undoped NdMnO 3 as part of our analysis. Taken together, these results show that the magnetic structure of the Mn sublattice in NdMn 0.8Fe 0.2O 3 is a combination of the Mn and Fe parent compounds, but the magnetic ordering of the Nd sublattice spans a broader temperature interval than in the case of NdMnO 3 and NdFeO 3. Lastly, this result is a consequence of the fact that the Nd ions do not order independently, but via polarization from the Mn/Fe sublattice.« less

Magnetic structure of the mixed antiferromagnet NdMn 0.8 Fe 0.2 O 3

DOE PAGES

Mihalik, Matus; Mihalik, Marian; Hoser, Andreas; ...

2017-10-27

The magnetic structure of the mixed antiferromagnet NdMn 0.8Fe 0.2O 3 was resolved. Neutron powder diffraction data definitively resolve the Mn sublattice with a magnetic propagation vector k=(000) and with the magnetic structure (A x, F y, G z) for 1.6 K N(≈ 59 K). The Nd sublattice has a (0, f y, 0) contribution in the same temperature interval. The Mn sublattice undergoes a spin-reorientation transition at T 1 ≈ 13 K while the Nd magnetic moment abruptly increases at this temperature. Powder x-ray diffraction shows a strong magnetoelastic effect at T N but no additional structural phase transitionsmore » from 3 to 300 K. Density functional theory calculations confirm the magnetic structure of the undoped NdMnO 3 as part of our analysis. Taken together, these results show that the magnetic structure of the Mn sublattice in NdMn 0.8Fe 0.2O 3 is a combination of the Mn and Fe parent compounds, but the magnetic ordering of the Nd sublattice spans a broader temperature interval than in the case of NdMnO 3 and NdFeO 3. Lastly, this result is a consequence of the fact that the Nd ions do not order independently, but via polarization from the Mn/Fe sublattice.« less

The effects of Nd2O3 concentration in the laser emission of TeO2-ZnO glasses

NASA Astrophysics Data System (ADS)

Moreira, L. M.; Anjos, V.; Bell, M. J. V.; Ramos, C. A. R.; Kassab, L. R. P.; Doualan, D. J. L.; Camy, P.; Moncorgé, R.

2016-08-01

The present work reports the modification introduced by different Nd2O3 concentration on optical properties and the laser operation of Nd3+ doped (TeO2-ZnO) bulk tellurite glass. The spectroscopic data are analyzed within the Judd Ofelt formalism framework and the results are compared to the fluorescence lifetime and emission measurements to derive values for the quantum efficiency and the stimulated emission cross section of the considered 4F3/2 → 4I11/2 infrared laser transition around 1062.5 nm. Continuous-wave laser action is achieved with this bulk tellurite glass by pumping the sample inside a standard plan-concave mirror laser cavity with different output couplers. It is possible to observe coherent emission only for the lower concentration (0.5%(wt.) of Nd2 O3). Also laser action could only be observed for this sample with threshold pump power of 73 mW associated with a laser slope efficiency of 8% for an output coupler transmission of 4% indicating that TeO2-ZnO are potential materials for laser action. The results presented in this work together with those previously reported with higher concentration (1.0% (wt) of Nd2O3) determine the adequate Nd2O3 concentration for laser action and guide the correct experimental procedure for TeO2-ZnO glasses preparation.

46. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

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

46. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, CONTROL PANEL LEVEL (2ND DECK) OF ETHER AND ALCOHOL STILL BUILDING, LOOKING NORTH, SHOWING TWO ALCOHOL DISTILLATION TOWERS BEHIND 'MIXED SOLVENT UNIT' CONTROL PANEL. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

Collaborative study for the establishment of the 2(nd) International Standard for Bleomycin Complex A2/B2.

PubMed

Jorajuria, S; Raphalen, C; Dujardin, V; Daas, A

2015-01-01

Organization (WHO) International Standard (IS) for bleomycin complex A2/B2. Eight laboratories from different countries participated. Potencies of the candidate material were estimated by microbiological assays with sensitive micro-organisms. To ensure continuity between consecutive batches, the 1(st) IS for bleomycin complex A2/B2 was used as a reference. Based on the results of the study, the 2(nd) IS for bleomycin complex A2/B2 was adopted at the meeting of the WHO Expert Committee for Biological Standardization (ECBS) in 2014 with an assigned potency of 12 500 International Units (IU) per vial. The 2(nd) IS for bleomycin complex A2/B2 is available from the European Directorate for the Quality of Medicines & HealthCare (EDQM).

Magnetic and thermodynamic properties of Nd3NiGe2

NASA Astrophysics Data System (ADS)

Matsumoto, Keisuke T.; Hiraoka, Koichi

2018-05-01

We here report the magnetization, M, and specific heat, C, of Nd3NiGe2 , which crystallizes in the orthorhombic Gd3NiSi2 -type structure. Nd ions occupy three nonequivalent sites in a unit cell. Upon cooling, magnetization divided by magnetic field, M / B , increased sharply at the Curie temperature, TC, of 87 K and below 40 K. The former result indicates that the increase in M / B observed at TC is due to the long-range ferromagnetic order. The increase below 40 K is derived from a short-range correlation because of the absence of clear anomaly in C (T) . At 10 K and 2 K, the values of M undergo metamagnetic transitions. The value of magnetic specific heat divided by temperature shows a shoulder-like anomaly at around 20 K, which is attributed to antiferromagnetic behavior. Furthermore, two peaks in C (T) were observed at 4.5 K and 3.8 K, and these peaks occurred at lower temperatures in the presence of a magnetic field. This behavior is typical of materials with antiferromagnetic order. These observations are attributed to the competition between ferromagnetic and antiferromagnetic interactions, which is a result of the three nonequivalent Nd sites.

Crystal-field energy level analysis for Nd(3+) ions at the low symmetry C(1) site in [Nd(hfa)(4)(H(2)O)](N(C(2)H(5))(4)) single crystals.

PubMed

Mech, Agnieszka; Gajek, Zbigniew; Karbowiak, Mirosław; Rudowicz, Czesław

2008-09-24

Optical absorption measurements of Nd(3+) ions in single crystals of [Nd(hfa)(4)(H(2)O)](N(C(2)H(5))(4)) (hfa = hexafluoroacetyloacetonate), denoted Nd(hfa) for short, have been carried out at 4.2 and 298 K. This compound crystallizes in the monoclinic system (space group P 2(1)/n). Each Nd ion is coordinated to eight oxygen atoms that originate from the hexafluoroacetylacetonate ligands and one oxygen atom from the water molecule. A total of 85 experimental crystal-field (CF) energy levels arising from the Nd(3+) (4f(3)) electronic configuration were identified in the optical spectra and assigned. A three-step CF analysis was carried out in terms of a parametric Hamiltonian for the actual C(1) symmetry at the Nd(3+) ion sites. In the first step, a total of 27 CF parameters (CFPs) in the Wybourne notation B(kq), admissible by group theory, were determined in a preliminary fitting constrained by the angular overlap model predictions. The resulting CFP set was reduced to 24 specific independent CFPs using appropriate standardization transformations. Optimizations of the second-rank CFPs and extended scanning of the parameter space were employed in the second step to improve reliability of the CFP sets, which is rather a difficult task in the case of no site symmetry. Finally, seven free-ion parameters and 24 CFPs were freely varied, yielding an rms deviation between the calculated energy levels and the 85 observed ones of 11.1 cm(-1). Our approach also allows prediction of the energy levels of Nd(3+) ions that are hidden in the spectral range overlapping with strong ligand absorption, which is essential for understanding the inter-ionic energy transfer. The orientation of the axis system associated with the fitted CF parameters w.r.t. the crystallographic axes is established. The procedure adopted in our calculations may be considered as a general framework for analysis of CF levels of lanthanide ions at low (triclinic) symmetry sites.

9. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. ...

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

9. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. 30, 1938 (i) INT.- MANTEL, SOUTHEAST ROOM, 2nd. FLOOR - Captain William Wildes House, 872 Commercial Street, Weymouth, Norfolk County, MA

10. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. ...

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

10. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. 30, 1938 (j) INT.-MANTEL, SOUTHWEST ROOM, 2nd. FLOOR - Captain William Wildes House, 872 Commercial Street, Weymouth, Norfolk County, MA

12. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. ...

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

12. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. 3, 1938 (k) INT.- MANTLE, NORTHEAST ROOM, 2nd. FLOOR - Captain William Wildes House, 872 Commercial Street, Weymouth, Norfolk County, MA

Demagnetization of Nd 2Fe 14B, Pr 2Fe 14B, and Sm 2Co 17 Permanent Magnets in Spallation Irradiation Fields

DOE PAGES

Simos, Nikolaos; Ozaki, S.; Mokhov, N.; ...

2018-02-27

Prompted by the need for radiation-resistant permanent magnets for insertion devices (IDs) of high-brilliance next-generation synchrotrons such as the National Synchrotron Light Source II, the demagnetization of Nd 2Fe 14B and Pr 2Fe 14B was studied after exposure to a mixed irradiating field. Degradation and damage of the permanent magnetic material by components of electromagnetic showers induced in magnets by intense high-energy electron beams will alter the magnetic field structure of the IDs. Plate-like Nd 2Fe 14B magnets were irradiated to 1.8 Grad dose and were evaluated against Pr 2Fe 14B magnets irradiated to a lower dose of 20 Mrad.more » In addition, annular Sm 2Co 17 and Nd 2Fe 14B magnets integrated within a ferrofluidic feedthrough (FFFT) rotary seal were also irradiated to dose levels of 2 Grad for Sm 2Co 17 and 20 Mrad for Nd 2Fe 14B. Post-irradiation measurements of the magnetic intensity revealed that severe demagnetization exceeding 85% occurs in Nd 2Fe 14B magnets after only 50 Mrad dose and over 87% for Pr 2Fe 14B after 10 Mrad dose. The annular-shaped Sm 2Co 17 magnets of the FFFTs were almost insensitive to irradiation up to a dose of 2 Grad. Annular-shaped Nd 2Fe 14B magnets also showed resistance to demagnetization, a direct consequence of the annular shape which is characterized by the removal of the stronger demagnetizing field present at the center of a disk-like magnet. As a result, the sensitivity of boron-based permanent magnets to neutron energy (thermal versus fast) was also assessed via specifically designed experiments and discussed.« less

Demagnetization of Nd 2Fe 14B, Pr 2Fe 14B, and Sm 2Co 17 Permanent Magnets in Spallation Irradiation Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simos, Nikolaos; Ozaki, S.; Mokhov, N.

Prompted by the need for radiation-resistant permanent magnets for insertion devices (IDs) of high-brilliance next-generation synchrotrons such as the National Synchrotron Light Source II, the demagnetization of Nd 2Fe 14B and Pr 2Fe 14B was studied after exposure to a mixed irradiating field. Degradation and damage of the permanent magnetic material by components of electromagnetic showers induced in magnets by intense high-energy electron beams will alter the magnetic field structure of the IDs. Plate-like Nd 2Fe 14B magnets were irradiated to 1.8 Grad dose and were evaluated against Pr 2Fe 14B magnets irradiated to a lower dose of 20 Mrad.more » In addition, annular Sm 2Co 17 and Nd 2Fe 14B magnets integrated within a ferrofluidic feedthrough (FFFT) rotary seal were also irradiated to dose levels of 2 Grad for Sm 2Co 17 and 20 Mrad for Nd 2Fe 14B. Post-irradiation measurements of the magnetic intensity revealed that severe demagnetization exceeding 85% occurs in Nd 2Fe 14B magnets after only 50 Mrad dose and over 87% for Pr 2Fe 14B after 10 Mrad dose. The annular-shaped Sm 2Co 17 magnets of the FFFTs were almost insensitive to irradiation up to a dose of 2 Grad. Annular-shaped Nd 2Fe 14B magnets also showed resistance to demagnetization, a direct consequence of the annular shape which is characterized by the removal of the stronger demagnetizing field present at the center of a disk-like magnet. As a result, the sensitivity of boron-based permanent magnets to neutron energy (thermal versus fast) was also assessed via specifically designed experiments and discussed.« less

Four-wave-mixing and nonlinear cavity dumping of 280 picosecond 2nd Stokes pulse at 1.3 μm from Nd:SrMoO4 self-Raman laser

NASA Astrophysics Data System (ADS)

Smetanin, S. N.; Jelínek, M., Jr.; Kubeček, V.; Jelínková, H.; Ivleva, L. I.; Shurygin, A. S.

2016-01-01

The 280 picosecond 2nd Stokes Raman pulses at 1.3 μm were generated directly from the miniature diode-pumped Nd:SrMoO4 self-Raman laser. Using the 90° phase matching insensitive to the angular mismatch, the self-Raman laser allowed for the achievement of the four-wave-mixing generation of the 2nd Stokes Raman pulse directly in the active Nd:SrMoO4 crystal at stimulated Raman scattering (SRS) self-conversion of the laser radiation. The passive Cr:YAG Q-switching and nonlinear cavity dumping was used without any phase locking device.

2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND ...

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

2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND GARDEN, VIEW TO SOUTHWEST - Sears Roebuck & Company Mail Order Plant, Bounded by Lexington & Grenshaw Streets, Kedzie Avenue & Independence Boulevard, Chicago, Cook County, IL

Anomalous magnetoelastic behaviour near morphotropic phase boundary in ferromagnetic Tb 1-xNd xCo 2 system

DOE PAGES

Murtaza, Adil; Yang, Sen; Zhou, Chao; ...

2016-08-04

In this study, we report a morphotropic phase boundary (MPB) involved ferromagnetic system Tb 1-xNd xCo 2 and reveal the corresponding structural and magnetoelastic properties of this system. With high resolution synchrotron X-ray diffractometry, the crystal structure of the TbCo 2-rich side is detected to be rhombohedral and that of NdCo 2-rich side is tetragonal below their respective Curie temperatures TC. The MPB composition Tb 0.35Nd 0.65Co 2 corresponds to the coexistence of the rhombohedral phase (R-phase) and tetragonal phase ( T-phase). Contrary to previously reported MPB involved ferromagnetic systems, the MPB composition of Tb 0.35Nd 0.65Co 2 shows minimummore » magnetization which can be understood as compensation of sublattice moments between the R-phase and the T-phase. Furthermore, magnetostriction of Tb 1-xNd xCo 2 decreases with increasing Nd concentration until x = 0.8 and then increases in the negative direction with further increasing Nd concentration; the optimum point for magnetoelastic properties lies towards the rhombohedral phase. Finally, our work not only shows an anomalous type of ferromagnetic MPB but also provides an effective way to design functional materials.« less

Nd2-xCexCuO4-y/Nd2-xCexOy boundary and resistive switchings in mesoscopic structures on base of epitaxial Nd1.86Ce0.14CuO4-у films

NASA Astrophysics Data System (ADS)

Tulina, N. A.; Rossolenko, A. N.; Ivanov, A. A.; Sirotkin, V. V.; Shmytko, I. M.; Borisenko, I. Yu.; Ionov, A. M.

2016-08-01

Reverse and stable bipolar resistive switching effect (BRSE) was observed in planar Nd2-xCex CuO4-y/Nd2-xCexOx/Ag heterostructure. It was shown that the СVС of the BRSE observed has a diode character. Simulations were used to consider the influence of the nonuniform distribution of an electric field at the interface of a heterojunction on the effect of bipolar resistive switching in investigated structures. The inhomogeneous distribution of the electric field near the contact edge creates regions of higher electric field strength which, in turn, stimulates motion and redistribution of defects, changes of the resistive properties of the whole structure and formation of a percolation channel.

11. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. ...

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

11. Historic American Buildings Survey Arthur C. Haskell, Photographer Aug. 30, 1938 (m) INT.-WALL PAPER, SOUTHWEST ROOM, 2nd. FLOOR - Captain William Wildes House, 872 Commercial Street, Weymouth, Norfolk County, MA

Genome-wide increase in histone H2A ubiquitylation in a mouse model of Huntington's disease.

PubMed

McFarland, Karen N; Das, Sudeshna; Sun, Ting Ting; Leyfer, Dmitri; Kim, Mee-Ohk; Xia, Eva; Sangrey, Gavin R; Kuhn, Alexandre; Luthi-Carter, Ruth; Clark, Timothy W; Sadri-Vakili, Ghazaleh; Cha, Jang-Ho J

2013-01-01

Huntington's disease (HD) is a neurodegenerative disorder with selective vulnerability of striatal neurons and involves extensive transcriptional dysregulation early in the disease process. Previous work in cell and mouse models has shown that histone modifications are altered in HD. Specifically, monoubiquitylated histone H2A (uH2A) is present at the promoters of downregulated genes which led to the hypothesis that uH2A plays a role in transcriptional silencing in HD. To broaden our view of uH2A function in transcription in HD, we examined genome-wide binding sites of uH2A in 12-week old striatal tissue from R6/2 transgenic HD mouse model. We used chromatin immunoprecipitation followed by genomic promoter microarray hybridization (ChIP-chip) and then interrogated how these binding sites correlate with transcribed genes. Our analysis reveals that, while uH2A levels are globally increased at the genome in the transgenic (TG) striatum, uH2A localization at a gene did not strongly correlate with the absence of its transcript. Furthermore, analysis of differential ubiquitylation in wild-type (WT) and TG striata did not reveal the expected enrichment of uH2A at genes with decreased expression in the TG striatum. This first description of genome-wide localization of uH2A in an HD model reveals that monoubiquitylation of histone H2A may not function at the level of the individual gene but may rather influence transcription through global chromatin structure.

Flight-Time Identification of a UH-60A Helicopter and Slung Load

NASA Technical Reports Server (NTRS)

Cicolani, Luigi S.; McCoy, Allen H.; Tischler, Mark B.; Tucker, George E.; Gatenio, Pinhas; Marmar, Dani

1998-01-01

This paper describes a flight test demonstration of a system for identification of the stability and handling qualities parameters of a helicopter-slung load configuration simultaneously with flight testing, and the results obtained.Tests were conducted with a UH-60A Black Hawk at speeds from hover to 80 kts. The principal test load was an instrumented 8 x 6 x 6 ft cargo container. The identification used frequency domain analysis in the frequency range to 2 Hz, and focussed on the longitudinal and lateral control axes since these are the axes most affected by the load pendulum modes in the frequency range of interest for handling qualities. Results were computed for stability margins, handling qualities parameters and load pendulum stability. The computations took an average of 4 minutes before clearing the aircraft to the next test point. Important reductions in handling qualities were computed in some cases, depending, on control axis and load-slung combination. A database, including load dynamics measurements, was accumulated for subsequent simulation development and validation.

Development of a Hydrologic Characterization Technology for Fault Zones Phase II 2nd Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karasaki, Kenzi; Doughty, Christine; Gasperikova, Erika

2011-03-31

This is the 2nd report on the three-year program of the 2nd phase of the NUMO-LBNL collaborative project: Development of Hydrologic Characterization Technology for Fault Zones under NUMO-DOE/LBNL collaboration agreement. As such, this report is a compendium of the results by Kiho et al. (2011) and those by LBNL.

Phase equilibria and crystal chemistry of the CaO-1/2 >Nd2O3-CoOz system at 885 °C in air

NASA Astrophysics Data System (ADS)

Wong-Ng, W.; Laws, W.; Talley, K. R.; Huang, Q.; Yan, Y.; Martin, J.; Kaduk, J. A.

2014-07-01

The phase diagram of the CaO-1/2 >Nd2O3-CoOz system at 885 °C in air has been determined. The system consists of two calcium cobaltate compounds that have promising thermoelectric properties, namely, the 2D thermoelectric oxide solid solution, (Ca3-xNdx)Co4O9-z (0≤x≤0.5), which has a misfit layered structure, and Ca3Co2O6 which consists of 1D chains of alternating CoO6 trigonal prisms and CoO6 octahedra. Ca3Co2O6 was found to be a point compound without the substitution of Nd on the Ca site. The reported Nd2CoO4 phase was not observed at 885 °C. A ternary (Ca1-xNd1+x)CoO4-z (x=0) phase, or (CaNdCo)O4-z, was found to be stable at this temperature. A solid solution region of distorted perovskite (Nd1-xCax)CoO3-z (0≤x≤0.25, space group Pnma) was established. In the peripheral binary systems, while a solid solution region was identified for (Nd1-xCax)2O3-z (0≤x≤0.2), Nd was not found to substitute in the Ca site of CaO. Six solid solution tie-line regions and six three-phase regions were determined in the CaO-Nd2O3-CoOz system in air.

V/STOLAND avionics system flight-test data on a UH-1H helicopter

NASA Technical Reports Server (NTRS)

Baker, F. A.; Jaynes, D. N.; Corliss, L. D.; Liden, S.; Merrick, R. B.; Dugan, D. C.

1980-01-01

The flight-acceptance test results obtained during the acceptance tests of the V/STOLAND (versatile simplex digital avionics system) digital avionics system on a Bell UH-1H helicopter in 1977 at Ames Research Center are presented. The system provides navigation, guidance, control, and display functions for NASA terminal area VTOL research programs and for the Army handling qualities research programs at Ames Research Center. The acceptance test verified system performance and contractual acceptability. The V/STOLAND hardware navigation, guidance, and control laws resident in the digital computers are described. Typical flight-test data are shown and discussed as documentation of the system performance at acceptance from the contractor.

Coercivity enhancement of Nd-Fe-B hot-deformed magnets by the eutectic grain boundary diffusion process using Nd-Ga-Cu and Nd-Fe-Ga-Cu alloys

NASA Astrophysics Data System (ADS)

Liu, Lihua; Sepehri-Amin, H.; Sasaki, T. T.; Ohkubo, T.; Yano, M.; Sakuma, N.; Kato, A.; Shoji, T.; Hono, K.

2018-05-01

Nd80Ga15Cu5 and Nd62Fe14Ga20Cu4 alloys were used as diffusion sources for the eutectic grain boundary diffusion process, applying to 4 mm-thick Nd-Fe-B hot-deformed magnets. Both samples showed nearly same coercivity of 2.2 T, while the sample processed with Nd62Fe14Ga20Cu4 showed smaller remanence deterioration from 1.50 T to 1.30 T, in contrast to that of the sample processed with Nd80Ga15Cu5 to 1.08 T. Mr/Ms of the initial sample and the samples processed with Nd62Fe14Ga20Cu4 and Nd80Ga15Cu5 were 0.946, 0.934 and 0.917, respectively, suggesting that the sample processed with Nd62Fe14Ga20Cu4 retains stronger c-axis texture after the diffusion process. Nd-rich phases with Ia3 ¯ and fcc structures were observed in the sample processed with Nd80Ga15Cu5, while the Nd-rich phases with the Ia3 ¯ and hcp structures were found in the sample processed with Nd62Fe14Ga20Cu4, all of which are the phases commonly observed in Nd-Fe-B sintered magnets.

2. SITE BUILDING 002 SCANNER BUILDING VIEW IS ...

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

2. SITE BUILDING 002 - SCANNER BUILDING - VIEW IS LOOKING NORTH 80° WEST "B" FACE ALONG BUILDING "A" FACE. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Crystal-field energy level analysis for Nd3+ ions at the low symmetry C1 site in [Nd(hfa)4(H2O)](N(C2H5)4) single crystals

NASA Astrophysics Data System (ADS)

Mech, Agnieszka; Gajek, Zbigniew; Karbowiak, Mirosław; Rudowicz, Czesław

2008-09-01

Optical absorption measurements of Nd3+ ions in single crystals of [Nd(hfa)4(H2O)](N(C2H5)4) (hfa = hexafluoroacetyloacetonate), denoted Nd(hfa) for short, have been carried out at 4.2 and 298 K. This compound crystallizes in the monoclinic system (space group P 21/n). Each Nd ion is coordinated to eight oxygen atoms that originate from the hexafluoroacetylacetonate ligands and one oxygen atom from the water molecule. A total of 85 experimental crystal-field (CF) energy levels arising from the Nd3+ (4f3) electronic configuration were identified in the optical spectra and assigned. A three-step CF analysis was carried out in terms of a parametric Hamiltonian for the actual C1 symmetry at the Nd3+ ion sites. In the first step, a total of 27 CF parameters (CFPs) in the Wybourne notation Bkq, admissible by group theory, were determined in a preliminary fitting constrained by the angular overlap model predictions. The resulting CFP set was reduced to 24 specific independent CFPs using appropriate standardization transformations. Optimizations of the second-rank CFPs and extended scanning of the parameter space were employed in the second step to improve reliability of the CFP sets, which is rather a difficult task in the case of no site symmetry. Finally, seven free-ion parameters and 24 CFPs were freely varied, yielding an rms deviation between the calculated energy levels and the 85 observed ones of 11.1 cm-1. Our approach also allows prediction of the energy levels of Nd3+ ions that are hidden in the spectral range overlapping with strong ligand absorption, which is essential for understanding the inter-ionic energy transfer. The orientation of the axis system associated with the fitted CF parameters w.r.t. the crystallographic axes is established. The procedure adopted in our calculations may be considered as a general framework for analysis of CF levels of lanthanide ions at low (triclinic) symmetry sites.

Nd:YAG-CO(2) double-pulse laser induced breakdown spectroscopy of organic films.

PubMed

Weidman, Matthew; Baudelet, Matthieu; Palanco, Santiago; Sigman, Michael; Dagdigian, Paul J; Richardson, Martin

2010-01-04

Laser-induced breakdown spectroscopy (LIBS) using double-pulse irradiation with Nd:YAG and CO(2) lasers was applied to the analysis of a polystyrene film on a silicon substrate. An enhanced emission signal, compared to single-pulse LIBS using a Nd:YAG laser, was observed from atomic carbon, as well as enhanced molecular emission from C(2) and CN. This double-pulse technique was further applied to 2,4,6-trinitrotoluene residues, and enhanced LIBS signals for both atomic carbon and molecular CN emission were observed; however, no molecular C(2) emission was detected.

24. Historical American Buildings Survey L. C. Durette, Photographer July ...

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

24. Historical American Buildings Survey L. C. Durette, Photographer July 27, 1936 INTERIOR OF GARRISON NORTH CORNER 2nd FLOOR LOGS CHIPPED TO RECEIVE INSIDE PLASTER - Gilman Garrison, Water & Clifford Streets, Exeter, Rockingham County, NH

22. Historical American Buildings Survey L. C. Durette, Photographer July ...

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

22. Historical American Buildings Survey L. C. Durette, Photographer July 27, 1936 NORTH CORNER OF GARRISON 2nd STORY SHOWING LOGS CHIPPED TO RECEIVE INSIDE PLASTER - Gilman Garrison, Water & Clifford Streets, Exeter, Rockingham County, NH

Interfacial magnetic coupling in hetero-structure of Fe/double-perovskite NdBaMn2O6 single crystal

NASA Astrophysics Data System (ADS)

Lin, W. C.; Tsai, C. L.; Ogawa, K.; Yamada, S.; Gandhi, Ashish C.; Lin, J. G.

2018-04-01

The interfacial magnetic coupling between metallic Fe and the double-perovskite NdBaMn2O6 single crystal was investigated in the heterostructure of 4-nm Pd/10-nm Fe/NdBaMn2O6. A considerable magnetic coupling effect was observed in the temperature range coincident with the magnetic phase transition of NdBaMn2O6. When the temperature was elevated above 270 K, NdBaMn2O6 transformed from a state of antiferromagnetic fluctuating domains to a superparamagnetism-like (ferromagnetic fluctuation) state with high magnetic susceptibility. Concurrently, the interfacial magnetic coupling between the Fe layer and the NdBaMn2O6 crystal was observed, as indicated by the considerable squareness reduction and coercivity enhancement in the Fe layer. Moreover, the presence of the Fe layer changed the magnetic structure of NdBaMn2O6 from conventional 4-fold symmetry to 2-fold symmetry. These observations offer applicable insights into the mutual magnetic interaction in the heterostructures of metallic ferromagnetism/perovskite materials.

Nd3+-doped TeO2-Bi2O3-ZnO transparent glass ceramics for laser application at 1.06 μm

NASA Astrophysics Data System (ADS)

Hu, Xiaolin; Luo, Zhiwei; Liu, Taoyong; Lu, Anxian

2017-04-01

The high crystallinity transparent glass ceramics based on Nd3+-doped 70TeO2-15Bi2O3-15ZnO (TBZ) compositions were successfully prepared by two-step heat treatment process. The effects of Nd2O3 content on the thermal, structural, mechanical, and optical properties of TBZ glass ceramics were studied. The incorporation of Nd2O3 enhanced the crystallization tendency in the matrix glass composition. The crystal phase and morphology of Bi2Te4O11 in the glass ceramics were confirmed by X-ray diffraction and field emission scanning electron microscopy. Due to precipitate more crystal phase, the hardness values increased from 3.21 to 3.66 GPa. Eight absorption peaks were observed from 400 to 900 nm and three emission bands appeared in the range of 850-1400 nm. With the increasing of Nd2O3 content from 0.5 to 2.5 wt%, the intensity of absorption peaks enhanced and the emission intensity increased up to 1.0 wt% and then fell down for further dopant concentration. The fluorescence decay lifetime decreased rapidly starting from 1.5 wt% Nd2O3 content due to the obvious energy migration among Nd3+. According to the extreme strong emission band around 1062 nm and the optimum Nd2O3 content (1.0 wt%), N10 glass ceramic was considered as a potential material for 1.06 μm laser applications.

Study on magnetic properties of (Nd0.8Ce0.2)2-xFe12Co2B (x = 0-0.6) alloys

NASA Astrophysics Data System (ADS)

Tan, G. S.; Xu, H.; Yu, L. Y.; Tan, X. H.; Zhang, Q.; Gu, Y.; Hou, X. L.

2017-09-01

In the present work, (Nd0.8Ce0.2)2-xFe12Co2B (x = 0-0.6) permanent alloys are prepared by melt-spinning method. The hard magnetic properties of (Nd0.8Ce0.2)2-xFe12Co2B (x = 0-0.6) alloys annealed at optimum temperatures have been investigated systematically. Depending on the Nd, Ce concentration, the maximum energy product ((BH)max) and remanence (Br) increase gradually with x in the range of 0 ≤ x ≤ 0.4, whereas decrease gradually in the alloys with 0.4 < x ≤ 0.6. It is found that the optimum magnetic properties are obtained at x = 0.4: Hci = 4.9 kOe, Br = 10.1 kG, (BH)max = 13.7 MGOe. Specifically, magnetic field heat treatment below the Curie temperature is applied for (Nd0.8Ce0.2)1.6Fe12Co2B (x = 0.4) annealed ribbons. The magnetic properties Br, (BH)max and squareness are all enhanced after the magnetic field heat treatment. The (BH)max shows a substantial increase from 13.7 MGOe to 16.0 MGOe after the heat treatment at 623 K with a magnetic field of 1 T, which gets 17% improvement compared with that of the sample without a magnetic field heat treatment. We demonstrate that the magnetic field heat treatment plays a certain role in the magnetization reversal behavior and can improve the microstructure of (Nd0.8Ce0.2)1.6Fe12Co2B alloy.

Ultra-high precision 142Nd/144Nd measurements of the Proterozoic and implications for mixing in the Earth's mantle through time

NASA Astrophysics Data System (ADS)

Hyung, E.; Jacobsen, S. B.

2017-12-01

The decay of 146Sm to 142Nd is an excellent a tracer for early silicate differentiation events in the terrestrial planets, as the Sm/Nd ratio is usually fractionated during mantle partial melting and magma ocean crystallization. The short half-life (103 or 68 Ma) renders the system extinct within the first 500 Ma of Solar System formation. Samples with 142Nd/144Nd ratios that are substantially different from the bulk silicate Earth value of 142Nd/144Nd provide clear evidence for mantle differentiation in the Hadean. Published data for the 3.4 to 3.8 Ga old Isua supracrustal rocks and dykes have demonstrated both positive and negative 142Nd/144Nd anomalies (30 ppm range) providing clear evidence for Hadean enriched and depleted mantle reservoirs. In contrast, no 142Nd/144Nd anomalies have been found in modern day terrestrial samples with data that have 2σ uncertainties of about 5 ppm or more. Last year we reported improvements in 142Nd/144Nd measurements, using our IsotopX thermal ionization mass spectrometer, and obtained reproducibility of 142Nd/144Nd ratios to better than 2 ppm at the 2σ level. With this external reproducibility we found that all except one modern mantle-derived basalt had within error identical 142Nd/144Nd ratios. One sample is about 3.4 ppm lower than the rest of the modern basalt samples, providing evidence for some limited Hadean mantle differentiation signatures preserved up to present. We have also measured 142Nd/144Nd ratios for Proterozoic and Phanerozoic samples, whose ages range from 300 Ma to 2 Ga, to better than 2 ppm external reproducibility (2σ). Most of these samples also have 142Nd/144Nd ratios that cluster around the modern day value, but there are some samples that are either marginally high by 2 ppm or low by 2 ppm. Thus, while a 20 to 30 ppm range in 142Nd/144Nd is well resolved in the Archean, such large variability is not present in the Proterozoic and Phanerozoic. The relatively rapid changeover at the end of the Archean

7. Tower Building interior. First view of plant behind offices ...

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

7. Tower Building interior. First view of plant behind offices Equipment and double iron steps to 2nd floor. Beer parties were also held here. - Tivoli-Union Brewery, 1320-1348 Tenth Street, Denver, Denver County, CO

44. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

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

44. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, LOOKING UP DISTILLATION TOWER FROM 2ND LEVEL. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

Neutron Powder Diffraction Study on the Magnetic Structure of NdPd 5 Al 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metoki, Naoto; Yamauchi, Hiroki; Kitazawa, Hideaki

The magnetic structure of NdPd 5Al 2 has been studied by neutron powder diffraction. Here, we observed the magnetic reflections with the modulation vector q=(1/2,0,0)q=(1/2,0,0) below the ordering temperature T N. We also found a collinear magnetic structure with a Nd moment of 2.7(3) μB at 0.5 K parallel to the c-axis, where the ferromagnetically ordered a-planes stack with a four-Nd-layer period having a ++-- sequence along the a-direction with the distance between adjacent Nd layers equal to a/2 (magnetic space group P anma). This “stripe”-like modulation is very similar to that in CePd 5Al 2 with q=(0.235,0.235,0)q=(0.235,0.235,0) with themore » Ce moment parallel to the c-axis. These structures with in-plane modulation are a consequence of the two-dimensional nature of the Fermi surface topology in this family, originating from the unique crystal structure with a very long tetragonal unit cell and a large distance of >7 Å between the rare-earth layers separated by two Pd and one Al layers.« less

Neutron Powder Diffraction Study on the Magnetic Structure of NdPd 5 Al 2

DOE PAGES

Metoki, Naoto; Yamauchi, Hiroki; Kitazawa, Hideaki; ...

2017-02-24

The magnetic structure of NdPd 5Al 2 has been studied by neutron powder diffraction. Here, we observed the magnetic reflections with the modulation vector q=(1/2,0,0)q=(1/2,0,0) below the ordering temperature T N. We also found a collinear magnetic structure with a Nd moment of 2.7(3) μB at 0.5 K parallel to the c-axis, where the ferromagnetically ordered a-planes stack with a four-Nd-layer period having a ++-- sequence along the a-direction with the distance between adjacent Nd layers equal to a/2 (magnetic space group P anma). This “stripe”-like modulation is very similar to that in CePd 5Al 2 with q=(0.235,0.235,0)q=(0.235,0.235,0) with themore » Ce moment parallel to the c-axis. These structures with in-plane modulation are a consequence of the two-dimensional nature of the Fermi surface topology in this family, originating from the unique crystal structure with a very long tetragonal unit cell and a large distance of >7 Å between the rare-earth layers separated by two Pd and one Al layers.« less

1-mJ Q-switched diode-pumped Nd:BaY2F8 laser

NASA Astrophysics Data System (ADS)

Agnesi, Antonio; Carraro, Giovanni; Guandalini, Annalisa; Reali, Giancarlo; Sani, Elisa; Toncelli, Alessandra; Tonelli, Mauro

2004-08-01

We report what is to our knowledge the first high repetition rate Q-switched Nd:BaY2F8 (Nd:BaYF) laser pumped with a multiwatt fiber-coupled diode array tuned at 806 nm. As much as 2.42 W of average power and up to 1.05 mJ of pulse energy were obtained with 6.1 W of absorbed pump power, with excellent beam quality (M2<1.2) and linear polarization.

Picosecond Nd:BaY2F8 laser discretely tunable around 1 μm

NASA Astrophysics Data System (ADS)

Agnesi, A.; Pirzio, F.; Reali, G.; Toncelli, A.; Tonelli, M.

2010-09-01

Passive mode-locking of a diode-pumped Nd:BaY2F8 (Nd:BaYF) was achieved on four lines in the range 1040-1074 nm, employing a semiconductor saturable absorber mirror (SAM). Nearly Fourier-limited pulses with durations of 2.6 to 7.2 ps and output power ≈50 mW were generated in a dispersion-controlled resonator using a single prism for wavelength selection, tuning and dispersion management.

Test Review: The Profile of Mood States 2nd Edition

ERIC Educational Resources Information Center

Lin, Shuqiong; Hsiao, Yu-Yu; Wang, Miao

2014-01-01

The "Profile of Mood States 2nd Edition" (POMS 2) was published in 2012 by Multi-Health Systems (MHS) to assess transient feelings and mood among individuals aged 13 years and above. Evolving from the original POMS (McNair, Lorr, & Droppleman, 1971, 1992), the POMS 2 was designed for youth (13-17 years old) and adults (18 years old…

Evaluation of Nd-Loaded SnO2:F Films Coated via Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Turgut, G.

2018-05-01

Thin layers of single (F)- and double (F/Nd)-incorporated tin oxide have been coated on glass substrate via spray pyrolysis. The structural, morphological, electrical, and optical features of F-incorporated samples were evaluated depending on the Nd loading. X-ray diffraction analysis revealed that samples had tetragonal tin oxide structure with (211) and (200) preferential directions. The crystallite size and strain values varied from 37.98 nm and 1.21 × 10-3 to 52.12 nm and 1.88 × 10-3. Scanning electron microscopy analysis showed that the samples consisted of pyramidal, polyhedral, and needle-shaped granules. The lowest sheet resistance value of 1.22 Ω was found for 1.8 at.% Nd + 25 at.% F-coloaded SnO2. However, the widest optical bandgap of 4.01 eV was observed for the single 25 at.% F-loaded sample. The Urbach tail and figure of merit also changed in the ranges of 664 meV to 1296 meV and 6.4 × 10-2 Ω-1 to 2.3 × 10-3 Ω-1, respectively. The results presented herein indicate that the character of F-doped tin oxide films can be controlled by Nd loading and that these films could be useful for technological applications.

Evaluation of Nd-Loaded SnO2:F Films Coated via Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Turgut, G.

2018-07-01

Thin layers of single (F)- and double (F/Nd)-incorporated tin oxide have been coated on glass substrate via spray pyrolysis. The structural, morphological, electrical, and optical features of F-incorporated samples were evaluated depending on the Nd loading. X-ray diffraction analysis revealed that samples had tetragonal tin oxide structure with (211) and (200) preferential directions. The crystallite size and strain values varied from 37.98 nm and 1.21 × 10-3 to 52.12 nm and 1.88 × 10-3. Scanning electron microscopy analysis showed that the samples consisted of pyramidal, polyhedral, and needle-shaped granules. The lowest sheet resistance value of 1.22 Ω was found for 1.8 at.% Nd + 25 at.% F-coloaded SnO2. However, the widest optical bandgap of 4.01 eV was observed for the single 25 at.% F-loaded sample. The Urbach tail and figure of merit also changed in the ranges of 664 meV to 1296 meV and 6.4 × 10-2 Ω-1 to 2.3 × 10-3 Ω-1, respectively. The results presented herein indicate that the character of F-doped tin oxide films can be controlled by Nd loading and that these films could be useful for technological applications.

Navier-Stokes Simulation of UH-60A Rotor/Wake Interaction Using Adaptive Mesh Refinement

NASA Technical Reports Server (NTRS)

Chaderjian, Neal M.

2017-01-01

High-resolution simulations of rotor/vortex-wake interaction for a UH60-A rotor under BVI and dynamic stallconditions were carried out with the OVERFLOW Navier-Stokes code.a. The normal force and pitching moment variation with azimuth angle were in good overall agreementwith flight-test data, similar to other CFD results reported in the literature.b. The wake-grid resolution did not have a significant effect on the rotor-blade airloads. This surprisingresult indicates that a wake grid spacing of (Delta)S=10% ctip is sufficient for engineering airloads predictionfor hover and forward flight. This assumes high-resolution body grids, high-order spatial accuracy, anda hybrid RANS/DDES turbulence model.c. Three-dimensional dynamic stall was found to occur due the presence of blade-tip vortices passing overa rotor blade on the retreating side. This changed the local airfoil angle of attack, causing stall, unlikethe 2D perspective of pure pitch oscillation of the local airfoil section.

NASA 2nd Generation RLV Program Introduction, Status and Future Plans

NASA Technical Reports Server (NTRS)

Dumbacher, Dan L.; Smith, Dennis E. (Technical Monitor)

2002-01-01

The Space Launch Initiative (SLI), managed by the Second Generation Reusable Launch Vehicle (2ndGen RLV) Program, was established to examine the possibility of revolutionizing space launch capabilities, define conceptual architectures, and concurrently identify the advanced technologies required to support a next-generation system. Initial Program funds have been allocated to design, evaluate, and formulate realistic plans leading to a 2nd Gen RLV full-scale development (FSD) decision by 2006. Program goals are to reduce both risk and cost for accessing the limitless opportunities afforded outside Earth's atmosphere fo civil, defense, and commercial enterprises. A 2nd Gen RLV architecture includes a reusable Earth-to-orbit launch vehicle, an on-orbit transport and return vehicle, ground and flight operations, mission planning, and both on-orbit and on-the-ground support infrastructures All segments of the architecture must advance in step with development of the RLV if a next-generation system is to be fully operational early next decade. However, experience shows that propulsion is the single largest contributor to unreliability during ascent, requires the largest expenditure of time for maintenance, and takes a long time to develop; therefore, propulsion is the key to meeting safety, reliability, and cost goals. For these reasons, propulsion is SLI's top technology investment area.

Early Earth evolution: new insight from Sm and Nd isotopes in meteoritic inclusions

NASA Astrophysics Data System (ADS)

Bouvier, A.; Boyet, M.

2014-12-01

The interpretation of Sm-Nd systematics for the early Earth relies on knowing the composition of the silicate Earth and the 146Sm decay constant. We have measured both 146Sm-142Nd and 147Sm-143Nd internal systematics of four individual Calcium, Aluminum-rich Inclusions (CAIs), the first solids formed in the Solar System [1], from 3 different carbonaceous chondrites from the CV3 group: Allende, Northwest Africa (NWA) 2364 and NWA 6991. Results obtained on NWA 6991 plot on a well-defined mineral and bulk isochron with a Solar System initial 146Sm/144Sm ratio of 0.0070 ±0.0024. This ratio is more consistent with the ratio defined from internal isochrons of differentiated meteorites using the half-life of 103 Ma for 146Sm [2], instead of the value obtained considering the half-life of 68 Ma [3]. On the basis of nucleosynthethic anomalies in Sm and Nd isotopes [4], the ordinary (O) and enstatite (E) chondrites remain potential candidates for the Earth's building blocks. OC have an average deficit of -18±3 ppm relative to modern terrestrial 142Nd/144Nd, whereas EC range from the OC to the terrestrial values [4-6]. Sm stable isotope compositions of the analyzed CAIs indicate that galactic cosmic rays did not affect the 142Nd/144Nd compositions, but deficits are found in the pure p-process 144Sm nuclide (-240 to -290 ppm/ standard). These deficits may translate to 142Nd deficits of a few ppm. NWA 6991 CAI 146Sm-142Nd internal isochron passes through a 142Nd/144Nd ratio of -6 ±6 ppm relative to the terrestrial standard at a chondritic 147Sm/144Nd of 0.1960. We note that this value is identical to the enstatite chondrite average and the 142Nd/144Nd ratio of the lunar mantle, as defined recently by [7] using a chondritic Sm/Nd and Lu/Hf for the bulk Moon. While the determination of the Sm-Nd reference parameters for the bulk Earth is still contentious, the difference in 142Nd/144Nd between modern terrestrial rocks and meteorites analyzed so far is <10ppm. [1] Bouvier and

Luminescence mechanism and energy transfer in doubly-doped BaY2F8:Tm,Nd VUV scintillator

NASA Astrophysics Data System (ADS)

Pejchal, J.; Nikl, M.; Moretti, F.; Vedda, A.; Fukuda, K.; Kawaguchi, N.; Yanagida, T.; Yokota, Y.; Yoshikawa, A.

2010-11-01

Doubly-doped BaY2F8:Tm,Nd scintillation crystals were grown by modified micro-pulling-down method. Nd co-doping was chosen to enhance the energy transfer from the host lattice to the Nd3+ luminescence center via the 5d-levels of Tm3+, due to the overlap of Tm3+ 5d-4f emission spectrum with the Nd3+ 4f-5d absorption. The energy transfer was clearly evidenced in the BaY2F8:Tm,Nd. This process is not complicated by an energy migration to killer centers and/or cross-relaxation. The radioluminescence process is complicated by an energy transfer from the host lattice exciton states to the lower f-levels of Tm3+ ion.

Influence of Nd and Y on texture of as-extruded Mg-5Li-3Al-2Zn alloy

NASA Astrophysics Data System (ADS)

Wu, Liqun; Zhang, Tianlong; Cui, Chongliang; Wu, Ruizhi; Zhang, Milin; Hou, Legan

2016-07-01

Mg-5Li-3Al-2Zn alloys with the additions of Y and Nd were prepared using induction melting furnace under the atmosphere of pure argon; then they were extruded. The textures of the as-extruded alloys were analyzed by pole figures and electron backscatter diffraction. Results show that the addition of a small amount of Nd can weaken the basal texture. The further increase of Nd content has no corresponding further influence on texture. When a small amount of Y is used to replace Nd, the basal texture can be further weakened and the prismatic slip system can be further activated. In the alloy of Mg-5Li-3Al-2Zn-1.2Y-0.8Nd, the basal textures almost vanish.

The many faces of ubiquitinated histone H2A: insights from the DUBs

PubMed Central

Vissers, Joseph HA; Nicassio, Francesco; van Lohuizen, Maarten; Di Fiore, Pier Paolo; Citterio, Elisabetta

2008-01-01

Monoubiquitination of H2A is a major histone modification in mammalian cells. Understanding how monoubiquitinated H2A (uH2A) regulates DNA-based processes in the context of chromatin is a challenging question. Work in the past years linked uH2A to transcriptional repression by the Polycomb group proteins of developmental regulators. Recently, a number of mammalian deubiquitinating enzymes (DUBs) that catalyze the removal of ubiquitin from H2A have been discovered. These studies provide convincing evidence that H2A deubiquitination is connected with gene activation. In addition, uH2A regulatory enzymes have crucial roles in the cellular response to DNA damage and in cell cycle progression. In this review we will discuss new insights into uH2A biology, with emphasis on the H2A DUBs. PMID:18430235

Two-photon momentum density in La2-xSrxCuO4 and Nd2-xCexCuO4

NASA Astrophysics Data System (ADS)

Blandin, P.; Massidda, S.; Barbiellini, B.; Jarlborg, T.; Lerch, P.; Manuel, A. A.; Hoffmann, L.; Gauthier, M.; Sadowski, W.; Walker, E.; Peter, M.; Yu, Jaejun; Freeman, A. J.

1992-07-01

We present calculations of the electron-positron momentum density for the high-Tc superconductors La2-xSrxCuO4 and Nd2-xCexCuO4, together with experimental two-dimensional angular correlation of annihilation radiation (2D-ACAR) for Nd2-xCexCuO4. The calculations are based on first-principles electronic structure obtained using the full-potential linearized augmented-plane-wave and the linear muffin-tin orbital methods. Our results indicate a non-negligible overlap of the positron wave function with the CuO2 plane electrons responsible for the Fermi surfaces in these compounds. Therefore, these compounds may be well suited for investigating Fermi-surface-related effects. After the folding of umklapp terms according to Lock, Crisp, and West, the predicted Fermi-surface breaks are mixed with strong effects induced by the positron wave function in La2-xSrxCuO4, while their resolution is better in Nd2-xCexCuO4. A comparison of our calculations with the most recent experimental results for La2-xSrxCuO4 shows good agreement. For Nd2-xCexCuO4 good agreement is observed between theoretical and experimental 2D-ACAR profiles.

Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...

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

Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM ‘D’, 2ND FLOOR PLAN, ARCHITECTURAL. Sheet 38 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...

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

Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM ‘C’, 2ND FLOOR PLAN, ARCHITECTURAL. Sheet 15 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...

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

Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM ‘B’, 2ND FLOOR PLAN, ARCHITECTURAL. Sheet 29 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

Low temperature texture development in Nd2Fe14B/α-Fe nanocomposite magnets via equal channel angular pressing

NASA Astrophysics Data System (ADS)

Besley, L.; Garitaonandia, J. S.; Molotnikov, A.; Kishimoto, H.; Kato, A.; Davies, C.; Suzuki, K.

2018-05-01

While suitable texture has been developed in Nd2Fe14B/α-Fe nanocomposites via thermomechanical processing methods such as die upsetting by incorporating low melting point eutectic Nd-Cu additives, significant grain coarsening occurs during this process due to the high temperature and long timescales involved, resulting in a loss of exchange coupling. Equal channel angular pressing (ECAP) is a severe plastic deformation technique which has been successfully used to produce a suitable texture in single-phase Nd2Fe14B at temperatures on the order of 500°C while preserving grain sizes on the order of 20-30nm. We investigate the development of texture in a commercial Nd2Fe14B/α-Fe nanocomposite alloy with added Nd90Cu10 produced via ECAP and then characterise it using texture x-ray diffraction and magnetic measurements. It is found that initial texture can be developed in this nanocomposite system at T = 520°C via ECAP. The average grain size of Nd2Fe14B as measured via X-ray diffraction after ECAP remains below 50nm with a developed texture. The effect of varying the amount of Nd90Cu10 additive is also investigated. It is found that with decreasing Nd90Cu10, the degree of texture is reduced while the volume fraction of α-Fe increases. This work demonstrates the development of texture in nanocomposite Nd2Fe14B/α-Fe with Nd-Cu additives whilst maintaining a grain size of approximately 50nm.

Czochralski and modified Bridgman-Stockbarger growth of pure, Cd 2+ and Nd 3+ doped benzil single crystals

NASA Astrophysics Data System (ADS)

Aggarwal, M. D.; Wang, W. S.; Tambwe, M.

1993-03-01

Pure, Cd2+ and Nd3+-doped benzil C6H5COCOC6H5 have been grown from melt using the Czochralski and modified Bridgman-Stockbarger methods. Angle-tuned second harmonic generation of pure benzil from Nd:YAG laser radiation of λ = 1.06 μm with a conversion efficiency η = I2w/Iw = 0.4% has been demonstrated. We have used a Nd:YAG pulse laser to measure the radiation damage threshold as 15.9 MW/cm2 (c-axis) and 23.9 MW/cm2 (a-axis) under the conditions that laser pulse width is 10 ns. Under the same conditions, the conversion efficiency of Nd3+ and Cd2+-doped benzil, η= I2w/Iw = 1.1%, has been demonstrated. The radiation threshold is higher than for pure benzil crystals.

2nd Generation RLV: Program Goals and Acquisition Strategy

NASA Technical Reports Server (NTRS)

Graham, J. Bart; Dumbacher, D. L. (Technical Monitor)

2001-01-01

The risk to loss of life for Space Shuttle crewmembers is approximately one in 245 missions. U.S. launch service providers captured nearly 100%, of the commercial launch market revenues in the mid 1980s. Today, the U.S. captures less than 50% of that market. A launch system architecture is needed that will dramatically increase the safety of space flight while significantly reducing the cost. NASA's Space Launch Initiative, which is implemented by the 2nd Generation RLV Program Office at Marshall Space Flight Center, seeks to develop technology and reusable launch vehicle concepts which satisfy the commercial launch market needs and the unique needs of NASA. Presented in this paper are the five primary elements of NASA's Integrated Space Transportation Plan along with the highest level goals and the acquisition strategy of the 2nd Generation RLV Program. Approval of the Space Launch Initiative FY01 budget of $290M is seen as a major commitment by the Agency and the Nation to realize the commercial potential that space offers and to move forward in the exploration of space.

Microstructure evolution and coercivity enhancement in Nd-Fe-B thin films diffusion-processed by R-Al alloys (R=Nd, Pr)

NASA Astrophysics Data System (ADS)

Xie, Yigao; Yang, Yang; Zhang, Tongbo; Fu, Yanqing; Jiang, Qingzheng; Ma, Shengcan; Zhong, Zhenchen; Cui, Weibin; Wang, Qiang

2018-05-01

Diffusion process by Nd-Al and Pr-Al alloys was compared and investigated in Nd-Fe-B thin films. Enhanced coercivity 2.06T and good squareness was obtained by using Pr85Al15 and Nd85Al15 alloys as diffusion sources. But the coercivity of diffusion-processed thin films by Pr70Al30 and Pr55Al45 alloys decreased to 2.04T and 1.82T. High ambient coercivity of 2.26T was achieved in diffusion-processed thin film by Nd70Al30 leading to an improved coercivity thermal stability because Nd2Fe14B grains were enveloped by Nd-rich phase as seen by transmission electron microscopy Nd-loss image. Meanwhile, microstructure-dependent parameters α and Neff were improved. However, high content of Al in diffusion-processed thin film by Nd55Al45 lead to degraded texture and coercivity.

15. Historic American Buildings Survey E. W. Russell, Photographer, March ...

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

15. Historic American Buildings Survey E. W. Russell, Photographer, March 15, 1936 BLINDS ON FRENCH TYPE DOOR OPENING ON W. REAR PORCH, 2nd STORY, N. SIDE APARTMENT - Augustine Ottenstein House, 207-209 North Jackson Street, Mobile, Mobile County, AL

Effect of V-Nd co-doping on phase transformation and grain growth process of TiO2

NASA Astrophysics Data System (ADS)

Khatun, Nasima; Amin, Ruhul; Anita, Sen, Somaditya

2018-05-01

The pure and V-Nd co-doped TiO2 samples are prepared by the modified sol-gel process. The phase formation is confirmed by XRD spectrum. Phase transformation is delayed in V-Nd co-doped TiO2 (TVN) samples compared to pure TiO2. The particle size is comparatively small in TVN samples at both the temperature 450 °C and 900 °C. Hence the effect of Nd doping is dominated over V doping in both phase transformation and grain growth process of TiO2.

Histologic comparison of the CO2 laser and Nd:YAG with and without water/air surface cooling on tooth root structure

NASA Astrophysics Data System (ADS)

Cobb, Charles M.; Spencer, Paulette; McCollum, Mark H.

1995-05-01

Specimens consisted of 18 extracted single rooted teeth unaffected by periodontal disease. After debriding roots, specimens were randomly divided into 4 treatment groups and subjected to a single pass, at varying energy densities, of a CO2, Nd:YAG, and Nd:YAG with air/water surface cooling (Nd:YAG-C). The rate of exposure was controlled at 4 mm/sec. Approximate energy densities were: CO2, 138, 206, 275, and 344 J/cm2; Nd:YAG, 114, 171, 229, and 286 J/cm2; Nd:YAG-C, 286, 343, 514, and 571 J/cm2. The CO2 laser was used both in continuous and pulsed beam modes (20 Hz, 0.01 sec pulse length and 0.8 mm dia spot size) whereas the Nd:YAG and Nd:YAG-C were preset at 50 Hz, 0.08 sec pulse length and 0.6 mm dia spot size. Specimen examination by SEM revealed, for all lasers, a direct correlation between increasing energy densities and depth of tissue ablation and width of tissue damage. However, to achieve the same relative dept of tissue ablation, the Nd:YAG-C required higher energy densities than either the CO2 or Nd:YAG lasers. The Nd:YAG-C generated a cavitation with sharply defined margins. Furthermore, regardless of energy density, and in contrast with other laser types, areas treated with the Nd:YAG-C did not exhibit collateral zones of heat damaged surface tissue.

Interplay of structural chemistry and magnetism in perovskites; A study of CaLn2Ni2WO9; Ln=La, Pr, Nd

NASA Astrophysics Data System (ADS)

Chin, Chun-Mann; Paria Sena, Robert; Hunter, Emily C.; Hadermann, Joke; Battle, Peter D.

2017-07-01

Polycrystalline samples of CaLn2Ni2WO9 (Ln=La, Pr, Nd) have been synthesized and characterised by a combination of X-ray and neutron diffraction, electron microscopy and magnetometry. Each composition adopts a perovskite-like structure with a 5.50, b 5.56, c 7.78 Å, β 90.1° in space group P21/n. Of the two crystallographically distinct six-coordinate sites, one is occupied entirely (Ln=Pr) or predominantly (Ln=La, Nd) by Ni2+ and the other by Ni2+ and W6+ in a ratio of approximately 1:2. None of the compounds shows long-range magnetic order at 5 K. The magnetometry data show that the magnetic moments of the Ni2+ cations form a spin glass below 30 K in each case. The Pr3+ moments in CaPr2Ni2WO9 also freeze but the Nd3+ moments in CaNd2Ni2WO9 do not. This behaviour is contrasted with that observed in other (A,A')B2B'O9 perovskites.

A DICOM-based 2nd generation Molecular Imaging Data Grid implementing the IHE XDS-i integration profile.

PubMed

Lee, Jasper; Zhang, Jianguo; Park, Ryan; Dagliyan, Grant; Liu, Brent; Huang, H K

2012-07-01

A Molecular Imaging Data Grid (MIDG) was developed to address current informatics challenges in archival, sharing, search, and distribution of preclinical imaging studies between animal imaging facilities and investigator sites. This manuscript presents a 2nd generation MIDG replacing the Globus Toolkit with a new system architecture that implements the IHE XDS-i integration profile. Implementation and evaluation were conducted using a 3-site interdisciplinary test-bed at the University of Southern California. The 2nd generation MIDG design architecture replaces the initial design's Globus Toolkit with dedicated web services and XML-based messaging for dedicated management and delivery of multi-modality DICOM imaging datasets. The Cross-enterprise Document Sharing for Imaging (XDS-i) integration profile from the field of enterprise radiology informatics was adopted into the MIDG design because streamlined image registration, management, and distribution dataflow are likewise needed in preclinical imaging informatics systems as in enterprise PACS application. Implementation of the MIDG is demonstrated at the University of Southern California Molecular Imaging Center (MIC) and two other sites with specified hardware, software, and network bandwidth. Evaluation of the MIDG involves data upload, download, and fault-tolerance testing scenarios using multi-modality animal imaging datasets collected at the USC Molecular Imaging Center. The upload, download, and fault-tolerance tests of the MIDG were performed multiple times using 12 collected animal study datasets. Upload and download times demonstrated reproducibility and improved real-world performance. Fault-tolerance tests showed that automated failover between Grid Node Servers has minimal impact on normal download times. Building upon the 1st generation concepts and experiences, the 2nd generation MIDG system improves accessibility of disparate animal-model molecular imaging datasets to users outside a molecular

Large positive magnetoresistance in intermetallic compound NdCo2Si2

NASA Astrophysics Data System (ADS)

Roy Chowdhury, R.; Dhara, S.; Das, I.; Bandyopadhyay, B.; Rawat, R.

2018-04-01

The magnetic, magneto-transport and magnetocaloric properties of antiferromagnetic intermetallic compound NdCo2Si2 (TN = 32K) have been studied. The compound yields a positive magnetoresistance (MR) of about ∼ 123 % at ∼ 5K in 8 T magnetic field. The MR value is significantly large vis - a - vis earlier reports of large MR in intermetallic compounds, and possibly associated with the changes in magnetic structure of the compound. The large MR value can be explained in terms of field induced pseudo-gaps on Fermi surface.

Testing Models for the Origin of the Earth-Moon System with 142Nd/144Nd Measurements

NASA Astrophysics Data System (ADS)

Hyung, E.; Jacobsen, S. B.; Zeng, L.

2015-12-01

The Sm-Nd system is widely used for tracking the differentiation and evolution of planetary silicate reservoirs, due to the well understood, strong Sm-Nd fractionation between melt and mantle minerals. The short-lived 146Sm-142Nd system with a half-life of 103 Ma or 68 Ma has been used to constrain early planetary differentiation events based on early Archean terrestrial rocks, lunar rocks and meteorites. Early Archean terrestrial rocks show significant variations in 142Nd/144Nd of about 30 ppm, demonstrating very early differentiation of the Earth's mantle and crust. In contrast, present day 142Nd/144Nd ratios of mantle-derived ocean island basalts and MORBs show almost no variation at the reported analytical precision level (2σ = ± 6 ppm), suggesting that such early variations have been erased with time due to crustal recycling and mantle mixing. The 142Nd/144Nd ratio of the lunar mantle has been reported to be offset from terrestrial standards by about -5 ppm, barely resolvable with the reported analytical uncertainties. Differences in the 142Nd/144Nd ratios between the bulk Earth and Moon may suggest early large scale silicate differentiation events on the Earth that predate the Giant Moon forming impact. To address this problem, we carry out new 142Nd/144Nd measurements of terrestrial rocks, and lunar rocks and meteorites with a TIMS (Isoprobe T) equipped with new Xact Faraday amplifiers provided by Isotopx. We find that the Xact amplifiers provide lower noise than the earlier generation preamplifiers and operate close to the theoretical thermodynamic noise limit calculated from the Johnson equation. So far we have been able to improve multidynamic measurements to be reproducible to within ± 2 ppm at the 2σ level, and with this precision we find no variations in a few young terrestrial rocks. Our next step is measurements of lunar rocks and E-chondrites. If these turn out to be identical to the modern Earth, then the Nd isotope system may tell the same

Nd:YAG and CO2 laser therapy of oral mucosal lesions.

PubMed

White, J M; Chaudhry, S I; Kudler, J J; Sekandari, N; Schoelch, M L; Silverman, S

1998-12-01

Experiences gained in the management of oral mucosal lesions by CO2 and Nd:YAG laser therapy in an outpatient clinic treated over an 80-year period are described. Lasers have indications for use in dentistry for incision, excision, and coagulation of intraoral soft tissue. Advances in laser technology have provided delivery systems for site-specific delivery of laser energy with short interaction items on tissue to be ablated. This study retrospectively evaluates a series of clinical case studies. Sixty-four patients with a variety of benign oral soft tissue lesions were treated by laser excision. Thirty-five patients were treated by a pulsed fiberoptic delivered Nd:YAG contact laser, and 29 by a continuous free-beam CO2 non-contact laser. The largest group of lesions treated were leukoplakia (39 cases). Other lesions excised and biopsied were lichen planus, squamous papilloma, pyogenic granuloma, focal melanosis, nonhealing traumatic ulceration, hemangioma, and lymphangioma. All patients were followed postoperatively (mean 6.8 months, range 1-36 months). Laser excision was well tolerated by patients with no intraoperative or postoperative adverse effects. All patients healed postsurgically with no loss of function. CO2 and Nd:YAG lasers are successful surgical options when performing excision of benign intraoral lesions. Advantages of laser therapy include minimal postoperative pain, conservative site-specific minimally invasive surgeries, and elimination of need for sutures.

Investigation of Rotor Performance and Loads of a UH-60A Individual Blade Control System

NASA Technical Reports Server (NTRS)

Yeo, Hyeonsoo; Romander, Ethan A.; Norman, Thomas R.

2011-01-01

Wind tunnel measurements of performance, loads, and vibration of a full-scale UH-60A Black Hawk main rotor with an individual blade control (IBC) system are compared with calculations obtained using the comprehensive helicopter analysis CAMRAD II and a coupled CAMRAD II/OVERFLOW 2 analysis. Measured data show a 5.1% rotor power reduction (8.6% rotor lift to effective-drag ratio increase) using 2/rev IBC actuation with 2.0 amplitude at = 0.4. At the optimum IBC phase for rotor performance, IBC actuator force (pitch link force) decreased, and neither flap nor chord bending moments changed significantly. CAMRAD II predicts the rotor power variations with the IBC phase reasonably well at = 0.35. However, the correlation degrades at = 0.4. Coupled CAMRAD II/OVERFLOW 2 shows excellent correlation with the measured rotor power variations with the IBC phase at both = 0.35 and = 0.4. Maximum reduction of IBC actuator force is better predicted with CAMRAD II, but general trends are better captured with the coupled analysis. The correlation of vibratory hub loads is generally poor by both methods, although the coupled analysis somewhat captures general trends.

Investigation of Rotor Performance and Loads of a UH-60A Individual Blade Control System

NASA Technical Reports Server (NTRS)

Yeo, Hyeonsoo; Romander, Ethan A.; Norman, Thomas R.

2011-01-01

Wind tunnel measurements of performance, loads, and vibration of a full-scale UH-60A Black Hawk main rotor with an individual blade control (IBC) system are compared with calculations obtained using the comprehensive helicopter analysis CAMRAD II and a coupled CAMRAD II/OVERFLOW 2 analysis. Measured data show a 5.1% rotor power reduction (8.6% rotor lift to effective-drag ratio increase) using 2/rev IBC actuation with 2.0. amplitude at u = 0.4. At the optimum IBC phase for rotor performance, IBC actuator force (pitch link force) decreased, and neither flap nor chord bending moments changed significantly. CAMRAD II predicts the rotor power variations with IBC phase reasonably well at u = 0.35. However, the correlation degrades at u = 0.4. Coupled CAMRAD II/OVERFLOW 2 shows excellent correlation with the measured rotor power variations with IBC phase at both u = 0.35 and u = 0.4. Maximum reduction of IBC actuator force is better predicted with CAMRAD II, but general trends are better captured with the coupled analysis. The correlation of vibratory hub loads is generally poor by both methods, although the coupled analysis somewhat captures general trends.

CW and passively Q-switched laser performance of Nd:Lu2SiO5 crystal

NASA Astrophysics Data System (ADS)

Xu, Xiaodong; Di, Juqing; Zhang, Jian; Tang, Dingyuan; Xu, Jun

2016-01-01

We demonstrated an efficient and controllable dual-wavelength continuous-wave (CW) laser of Nd:Lu2SiO5 (Nd:LSO) crystal. The maximum output power was 3.02 W at wavelength of 1075 nm and 1079 nm, and with increasing of absorbed pump power, the ratio of 1079 nm laser rose. The slope efficiency of 65.6% and optical-to-optical conversion efficiency of 63.3% were obtained. The passively Q-switched laser properties of Nd:LSO were investigated for the first time. The shortest pulse, maximum pulse energy and peak power were 11.58 ns, 29.05 μJ and 2.34 kW, respectively.

Structural and optical properties of nano-sized K3Nd(PO4)2:Yb3+ orthophosphate.

PubMed

Mizer, D; Macalik, L; Tomaszewski, P E; Lisiecki, R; Godlewska, P; Matraszek, A; Szczygieł, I; Zawadzki, M; Hanuza, J

2009-09-01

Nanocrystals of tripotassium neodymium bis-phosphate(V) doped with ytterbium ions, K3Nd(PO4)2: Yb3+, were synthesized by Pechini method. The obtained grains, having an average size of about 40 nm, were characterised by X-ray, electron microscopic, electron absorption, luminescence and IR studies. Moreover, fluorescence decay studies were carried out at room temperature. The energy transfer from the Nd3+ to Yb3+ was described and discussed. The results were compared to those of the K3Nd(PO4)2 bulk crystal.

Diode-pumped femtosecond mode-locked Nd, Y-codoped CaF2 laser

NASA Astrophysics Data System (ADS)

Zhu, Jiangfeng; Zhang, Lijuan; Gao, Ziye; Wang, Junli; Wang, Zhaohua; Su, Liangbi; Zheng, Lihe; Wang, Jingya; Xu, Jun; Wei, Zhiyi

2015-03-01

A passively mode-locked femtosecond laser based on an Nd, Y-codoped CaF2 disordered crystal was demonstrated. The Y3+-codoping in Nd : CaF2 markedly suppressed the quenching effect and improved the fluorescence quantum efficiency and emission spectra. With a fiber-coupled laser diode as the pump source, the continuous wave tuning range covering from 1042 to 1076 nm was realized, while the mode-locked operation generated 264 fs pulses with an average output power of 180 mW at a repetition rate of 85 MHz. The experimental results show that the Nd, Y-codoped CaF2 disordered crystal has potential in a new generation diode-pumped high repetition rate chirped pulse amplifier.

Enhanced light emission near 2.7 μm from Er-Nd co-doped germanate glass

NASA Astrophysics Data System (ADS)

Bai, Gongxun; Tao, Lili; Li, Kefeng; Hu, Lili; Tsang, Yuen Hong

2013-04-01

Laser glass gain medium that can convert low cost 808 nm diode laser into 2.7 μm has attracted considerable interest due to its potential application for medical surgery fiber laser system. In this study, enhanced 2.7 μm emission has been achieved in Er3+:germanate glass by co-doping with Nd3+ ions under the excitation of an 808 nm diode laser. In the co-doped sample, the experimental results show that the harmful visible emissions via up-conversion were effectively restricted. The reduction of 1.5 μm emission was also detected in the co-doped sample, which indicates significant de-excitation of 4I13/2 Er3+ ion through energy transfer and non-radiative decay in Nd3+ ions. In conclusion, the 2.7 μm emission enhancement achieved was due to the increased optical absorption of 808 nm, efficient energy transfer (ET) with efficiency of 81.73% between Er3+ and Nd3+ ions, and shortening the lifetime of the lower lasing level 4I13/2 Er3+ in the co-doped sample. Therefore, Er3+/Nd3+ co-doped germanate glass could be used to fabricate fiber optical gain media for 2.7 μm laser generation.

Superhyperfine Structure of the EPR Spectra of Nd3+ Impurity Ions in Fluorite CaF2

NASA Astrophysics Data System (ADS)

Aminov, L. K.; Gafurov, M. R.; Kurkin, I. N.; Malkin, B. Z.; Rodionov, A. A.

2018-05-01

EPR spectra of a CaF2 single crystal that was grown from melt containing a small addition of NdF3 were studied. Signals corresponding to tetragonal centers of Nd3+ ions and cubic centers of Er3+ and Yb3+ ions were found. Superhyperfine structure (SHFS) in the spectra of the Nd3+ ions was observed for the first time in this crystal; parameters of the superhyperfine interaction of the Nd3+ ions with the nearest nine fluorine ions were determined. The dependence of the resolution of the Nd3+ EPR spectrum SHFS on the incident microwave power at the temperature of T ≈ 6 K was studied. Obtained results are discussed and compared with the literature data.

1. Historic American Buildings Survey E. W. Russell, Photographer, April ...

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

1. Historic American Buildings Survey E. W. Russell, Photographer, April 7, 1936 BALUSTRADE ON 2nd FLOOR PORTICO, U. S. MARINE HOSPITAL, ST. ANTHONY ST. BETWEEN BAYOU AND JEFFERSON STREETS - U. S. Marine Hospital & Gates, 800 Saint Anthony Street, Mobile, Mobile County, AL

Fluorescence properties of Nd3+-doped tellurite glasses.

PubMed

Kumar, K Upendra; Prathyusha, V A; Babu, P; Jayasankar, C K; Joshi, A S; Speghini, A; Bettinelli, M

2007-07-01

The compositional and concentration dependence of luminescence of the (4)F(3/2)-->(4)I(J) (J=13/2, 11/2 and 9/2) transitions in four Nd(3+)-doped tellurite based glasses has been studied. The free-ion energy levels obtained for 60TeO(2)+39ZnO(2)+1.0Nd(2)O(3) (TZN10) glass have been analysed using the free-ion Hamiltonian model and compared with similar results obtained for Nd(3+):glass systems. The absorption spectrum of TZN10 glass has been analysed using the Judd-Ofelt theory. Relatively longer decay rates have been obtained for Nd(3+)-doped phosphotellurite glasses. The emission characteristics of the (4)F(3/2)-->(4)I(11/2) transition, of the Nd(3+):TZN10 glass, are found to be comparable to those obtained for Nd(3+):phosphate laser glasses. The non-exponential shape of the emission decay curves for the (4)F(3/2)-->(4)I(11/2) transition is attributed to the presence of energy transfer processes between the Nd(3+) ions.

2nd Annual Postdoc Research Day: US Army Research Laboratory PosterSymposia and Activities

DTIC Science & Technology

2018-04-12

ARL-SR-0394•APR 2018 US Army Research Laboratory 2nd Annual Postdoc Research Day: US Army Research Laboratory Poster Symposia and Activities by...Do not return it to the originator. ARL-SR-0394•APR 2018 US Army Research Laboratory 2nd Annual Postdoc Research Day: US Army Research Laboratory...Poster Symposia and Activities by Efraín Hernández–Rivera Weapons and Materials Research Directorate, ARL Julia Cline Oak Ridge Institute for Science and

Spelling performance of 2nd to 5th grade students from public school.

PubMed

Capellini, Simone Aparecida; Amaral, Amanda Corrêa do; Oliveira, Andrea Batista; Sampaio, Maria Nobre; Fusco, Natália; Cervera-Mérida, José Francisco; Ygual-Fernández, Amparo

2011-09-01

To characterize, compare and classify the performance of 2nd to 5th grade students from public schools according to the semiology of spelling errors. Participants were 120 students from 2nd to 5th grades of a public school in Marília (SP), Brazil, 30 students from each grade, who were divided into four groups: GI (2nd grade), GII (3rd grade), GIII (4th grade), and GIV (5th grade). The tasks of the Pro-Ortografia test were applied: collective version (writing of alphabet letters, randomized dictation of letters, words dictation, nonwords dictation, dictation with pictures, thematic writing induced by picture) and individual version (dictation of sentences, purposeful error, spelled dictation, orthographic lexical memory). Significant difference was found in the between-group comparison indicating better performance of students in every subsequent grade in most of the individual and collective version tasks. With the increase of grade level, the groups decreased the average of writing errors. The profile of spelling acquisition of the Portuguese writing system found in these public school students indicates normal writing development in this population.

Rotationally inelastic scattering of ND3 with H2 as a probe of the intermolecular potential energy surface

NASA Astrophysics Data System (ADS)

Tkáč, Ondřej; Saha, Ashim K.; Loreau, Jérôme; Ma, Qianli; Dagdigian, Paul J.; Parker, David H.; van der Avoird, Ad; Orr-Ewing, Andrew J.

2015-12-01

Differential cross sections (DCSs) are reported for rotationally inelastic scattering of ND3 with H2, measured using a crossed molecular beam apparatus with velocity map imaging (VMI). ND3 molecules were quantum-state selected in the ground electronic and vibrational levels and, optionally, in the j±k = 11- rotation-inversion level prior to collisions. Inelastic scattering of state-selected ND3 with H2 was measured at the mean collision energy of 580 cm-1 by resonance-enhanced multiphoton ionisation spectroscopy and VMI of ND3 in selected single final j'±k' levels. Comparison of experimental DCSs with close-coupling quantum-mechanical scattering calculations serves as a test of a recently reported ab initio potential energy surface. Calculated integral cross sections reveal the propensities for scattering into various final j'±k' levels of ND3 and differences between scattering by ortho and para H2. Integral and differential cross sections are also computed at a mean collision energy of 430 cm-1 and compared to our recent results for inelastic scattering of state-selected ND3 with He.

1. Northeast face of missile site control building, commonly known ...

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

1. Northeast face of missile site control building, commonly known as the missile site radar building, showing open blast door #BD2. This emergency escape, at stair no. 12, is NEMP/RFI-shielded and 16" thick. The large circle in the center is the radar face, also known as the antennae array aperture. The small circle to the right of the radar face is the "Q" channel. The antennae atop the turret provided lightning protection for the building - Stanley R. Mickelsen Safeguard Complex, Missile Site Control Building, Northeast of Tactical Road; southeast of Tactical Road South, Nekoma, Cavalier County, ND

Building Substantive Engagement through the Use of Connection Prompts

ERIC Educational Resources Information Center

Alamar, Amy

2013-01-01

Conversation is a strategy that helps students build reading skills and improve reading comprehension. This study describes the implementation of connection prompts in a 2nd-grade classroom to support students in making predictions, questioning the text, and initiating further conversation. Research suggests that once conversation is initiated,…

Generation of 103 fs mode-locked pulses by a gain linewidth-variable Nd,Y:CaF2 disordered crystal.

PubMed

Qin, Z P; Xie, G Q; Ma, J; Ge, W Y; Yuan, P; Qian, L J; Su, L B; Jiang, D P; Ma, F K; Zhang, Q; Cao, Y X; Xu, J

2014-04-01

We have demonstrated a diode-pumped passively mode-locked femtosecond Nd,Y:CaF2 disordered crystal laser for the first time to our knowledge. By choosing appropriate Y-doping concentration, a broad fluorescence linewidth of 31 nm has been obtained from the gain linewidth-variable Nd,Y:CaF2 crystal. With the Nd,Y:CaF2 disordered crystal as gain medium, the mode-locked laser generated pulses with pulse duration as short as 103 fs, average output power of 89 mW, and repetition rate of 100 MHz. To our best knowledge, this is the shortest pulse generated from Nd-doped crystal lasers so far. The research results show that the Nd,Y:CaF2 disordered crystal will be a potential alternative as gain medium of repetitive chirped pulse amplification for high-peak-power lasers.

Thermodynamic Modeling of the Ge-Nd Binary System

NASA Astrophysics Data System (ADS)

Liu, Miao; Li, Changrong; Du, Zhenmin; Guo, Cuiping; Niu, Chunju

The Ge-Nd has been critically assessed by means of the CALculation of PHAse Diagram (CALPHAD) technique. For the liquid phase, the associate model was used with the constituent species Ge, Nd, Ge3Nd5 and Ge1.6Nd in the Ge-Nd system. The terminal solid solution diamond-(Ge), dhcp-(Nd) and bcc_A2-(Nd) in the Ge-Nd system were described using the substitutional model, in which the excess Gibbs energy was formulated with the Redlich-Kister equation. The compounds with homogeneity ranges, α(Ge1.6Nd), β(Ge1.6Nd), (GeNd), (Ge4Nd5) and (Ge3Nd5) were modeled using two sublattices as α(Ge,Nd)1.6Nd, β(Ge,Nd)1.6Nd, (Ge,Nd)Nd, (Ge,Nd)4Nd5 and (Ge,Nd)3Nd5, respectively. A set of self-consistent thermodynamic parameters for each of the Ge-Nd binary systems was obtained. The calculation results agree well with the available experimental data from literatures.

6. 2nd floor where stables used to be; note bottom ...

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

6. 2nd floor where stables used to be; note bottom of truss with suspension rods for floor which results in clear span on 1st level - Diebolt Brewing Company Stable, 2695 Pittsburgh Avenue, Cleveland, Cuyahoga County, OH

Cutaneous pain effects induced by Nd:YAG and CO2 laser stimuli

NASA Astrophysics Data System (ADS)

Wang, Jia-Rui; Yu, Guang-Yuan; Yang, Zai-Fu; Chen, Hong-Xia; Hu, Dong-Dong; Zou, Xian-Biao

2012-12-01

The near infrared laser technique can activate cutaneous nociceptors with high specificity and reproducibility and be used in anti-riot equipment. This study aimed to explore cutaneous pain effect and determine the threshold induced by Nd:YAG and CO2 laser stimuli. The corresponding wavelength was 1.32μm and 10.6μm. The pain effect was assessed in three healthy subjects (1 woman and 2 men) on the skin of dorsum of both hands. The energy of each pulse and whether the subjects felt a painful sensation after each stimulus were recorded. A simplified Bliss Method was used to calculate the pain threshold which were determined under three pulse durations for Nd:YAG laser and one pulse duration for CO2 laser. As a result the pain thresholds were determined to be 5.6J/cm2, 5.4J/cm2 and 5.0J/cm2 respectively when using Nd:YAG laser, 4.0mm beam diameter, 8ms, 0.1s and 1s pulse duration. The pain threshold was 1.0J/cm2 when using CO2 laser, 4.0mm beam diameter and 0.1s pulse duration. We concluded that the threshold of cutaneous pain elicited by 1.32μm laser was independent upon the pulse duration when the exposure time ranged from 8ms to 1s. Under the same exposure condition, the threshold of cutaneous pain elicited by 1.32μm laser was higher than that elicited by 10.6μm laser.

2nd Generation RLV Risk Definition Program

NASA Technical Reports Server (NTRS)

Davis, Robert M.; Stucker, Mark (Technical Monitor)

2000-01-01

The 2nd Generation RLV Risk Reduction Mid-Term Report summarizes the status of Kelly Space & Technology's activities during the first two and one half months of the program. This report was presented to the cognoscente Contracting Officer's Technical Representative (COTR) and selected Marshall Space Flight Center staff members on 26 September 2000. The report has been approved and is distributed on CD-ROM (as a PowerPoint file) in accordance with the terms of the subject contract, and contains information and data addressing the following: (1) Launch services demand and requirements; (2) Architecture, alternatives, and requirements; (3) Costs, pricing, and business cases analysis; (4) Commercial financing requirements, plans, and strategy; (5) System engineering processes and derived requirements; and (6) RLV system trade studies and design analysis.

Magnetic interactions at Ce impurities in REMn2Ge2 (RE = La, Ce, Pr, Nd) compounds

NASA Astrophysics Data System (ADS)

Bosch-Santos, B.; Cabrera-Pasca, G. A.; Saxena, R. N.; Burimova, A. N.; Carbonari, A. W.

2018-05-01

In the work reported in this paper, the temperature dependence of the magnetic hyperfine field (Bh f) at 140Ce nuclei replacing Pr atoms in PrMn2Ge2 compound was measured by the perturbed angular correlation technique to complete the sequence of measurements in REMn2Ge2 (RE = La, Ce, Pr, Nd). Results show an anomalous behavior different from the expected Brillouin curve. A model was used to fit the data showing that the Ce impurity contribution (Bhfimp) to Bhf is negative for NdMn2Ge2 below 210 K. The impurity contribution (Bhfimp) at 0 K for all compounds is much smaller than that for the free Ce3+, showing that the 4f band of Ce is more likely highly hybridized with 5d band of the host. Results show that direction of the localized magnetic moment at Mn atoms strongly affects the exchange interaction at Ce impurities.

An animal model for Norrie disease (ND): gene targeting of the mouse ND gene.

PubMed

Berger, W; van de Pol, D; Bächner, D; Oerlemans, F; Winkens, H; Hameister, H; Wieringa, B; Hendriks, W; Ropers, H H

1996-01-01

In order to elucidate the cellular and molecular processes which are involved in Norrie disease (ND), we have used gene targeting technology to generate ND mutant mice. The murine homologue of the ND gene was cloned and shown to encode a polypeptide that shares 94% of the amino acid sequence with its human counterpart. RNA in situ hybridization revealed expression in retina, brain and the olfactory bulb and epithelium of 2 week old mice. Hemizygous mice carrying a replacement mutation in exon 2 of the ND gene developed retrolental structures in the vitreous body and showed an overall disorganization of the retinal ganglion cell layer. The outer plexiform layer disappears occasionally, resulting in a juxtaposed inner and outer nuclear layer. At the same regions, the outer segments of the photoreceptor cell layer are no longer present. These ocular findings are consistent with observations in ND patients and the generated mouse line provides a faithful model for study of early pathogenic events in this severe X-linked recessive neurological disorder.

Terahertz Spectroscopy and Global Analysis of the Rotational Spectrum of Doubly Deuterated Amidogen Radical ND2

NASA Astrophysics Data System (ADS)

Melosso, Mattia; Degli Esposti, Claudio; Dore, Luca

2017-11-01

The deuteration mechanism of molecules in the interstellar medium is still being debated. Observations of deuterium-bearing species in several astronomical sources represent a powerful tool to improve our understanding of the interstellar chemistry. The doubly deuterated form of the astrophysically interesting amidogen radical could be a target of detection in space. In this work, the rotational spectrum of the ND2 radical in its ground vibrational and electronic {X}2{B}1 state has been investigated between 588 and 1131 GHz using a frequency modulation millimeter/submillimeter-wave spectrometer. The ND2 molecule has been produced in a free-space glass absorption cell by discharging a mixture of ND3 and Ar. Sixty-four new transition frequencies involving J values from 2 to 5 and K a values from 0 to 4 have been measured. A global analysis including all the previous field-free pure rotational data has been performed, allowing for a more precise determination of a very large number of spectroscopic parameters. Accurate predictions of rotational transition frequencies of ND2 are now available from a few gigahertz up to several terahertz.

12. SW corner of 2nd floor of Tender Frame Shop ...

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

12. SW corner of 2nd floor of Tender Frame Shop showing heating duct and diffuser. - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Tender Frame Shop, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

3. View from missile site control building (southeast to northwest) ...

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

3. View from missile site control building (southeast to northwest) of missile launch area showing universal missile building on left and warhead handling building in background. - Stanley R. Mickelsen Safeguard Complex, Missile Launch Area, Within Exclusion Area, Nekoma, Cavalier County, ND

One pot synthesis of exchange coupled Nd2Fe14B/alpha-Fe by pechini type sol-gel method.

PubMed

Hussain, Abid; Jadhav, Abhijit P; Baek, Yeon Kyung; Choi, Hul Jin; Lee, Jaeho; Kang, Young Soo

2013-11-01

In this work, a combination of nanoparticles of Nd2Fe14B hard magnetic phase and alpha-Fe soft magnetic phase were synthesized by one pot chemical synthesis technique using sol-gel method. A gel of Nd-Fe-B was prepared using NdCl3 x 6H2O, FeCl3 x 6H2O, H3BO3, citric acid, and ethylene glycol by pechini type sol-gel method. The gel was subsequently calcined and annealed to obtain the mixed oxide powders. The produced metal oxide particles were identified with XRD, SEM, TEM to obtain the crystal structure, shape and domain structure of them. The nanoparticles of mixed phase of Nd2Fe14B/alpha-Fe were obtained from these oxides by a process of reduction-diffusion in vacuum by employing CaH2 as reducing agent. During this process it was optimized by controlling temperature, reaction time and concentration of the reducing agent (CaH2). The phase formation of Nd2Fe14B was resulted by the direct diffusion of NdH2, Fe and B. The magnetic property of produced hard and soft phases was successfully identified with vibrating sample magnetometer (VSM). The mixed domains of the hard and soft phases were identified with selected area electron diffraction method (SAED) patterns.

Blade Displacement Measurements of the Full-Scale UH-60A Airloads Rotor

NASA Technical Reports Server (NTRS)

Barrows, Danny A.; Burner, Alpheus W.; Abrego, Anita I.; Olson, Lawrence E.

2011-01-01

Blade displacement measurements were acquired during a wind tunnel test of the full-scale UH-60A Airloads rotor. The test was conducted in the 40- by 80-Foot Wind Tunnel of the National Full-Scale Aerodynamics Complex at NASA Ames Research Center. Multi-camera photogrammetry was used to measure the blade displacements of the four-bladed rotor. These measurements encompass a range of test conditions that include advance ratios from 0.15 to unique slowed-rotor simulations as high as 1.0, thrust coefficient to rotor solidity ratios from 0.01 to 0.13, and rotor shaft angles from -10.0 to 8.0 degrees. The objective of these measurements is to provide a benchmark blade displacement database to be utilized in the development and validation of rotorcraft computational tools. The methodology, system development, measurement techniques, and preliminary sample blade displacement measurements are presented.

Uh and um in Children With Autism Spectrum Disorders or Language Impairment

PubMed Central

Gorman, Kyle; Olson, Lindsay; Presmanes Hill, Alison; Lunsford, Rebecca; Heeman, Peter A.; van Santen, Jan P. H.

2016-01-01

Atypical pragmatic language is often present in individuals with autism spectrum disorders (ASD), along with delays or deficits in structural language. This study investigated the use of the “fillers” uh and um by children ages 4–8 during the autism diagnostic observation schedule. Fillers reflect speakers’ difficulties with planning and delivering speech, but they also serve communicative purposes, such as negotiating control of the floor or conveying uncertainty. We hypothesized that children with ASD would use different patterns of fillers compared to peers with typical development or with specific language impairment (SLI), reflecting differences in social ability and communicative intent. Regression analyses revealed that children in the ASD group were much less likely to use um than children in the other two groups. Filler use is an easy-to-quantify feature of behavior that, in concert with other observations, may help to distinguish ASD from SLI. PMID:26800246

Preliminary Inventory of the Retired Records of the 1st United States Army Infantry Division during the Vietnam War, 2 October 1965-14 April 1970. Sanitized Version.

DTIC Science & Technology

1982-05-01

con Oft uh 6 to the appdsb feual Rec"It Comer for RECORDS TRANSMITTAL AND RECEIPT apm pro to shipaat of f Spse arcns aon rese. PAMIf A. TO 4i5 ASd5 * pv... gmo -M IN nm nd 10mi AV No*5 m General Orders; General Correspondence; Daily Staff Journals; Tactical Operatiod Center (TOC) Logs; Cmand Reports...AGENiCYwo m a gewn.uirm DIPSL " 1n 2,I (w l6_t 4,11A 4s. 41) pollo~ 01)S 10~e 1~e (1) (A)A. IndiOs Cap Ill StA SAC(G3O4NID: Th.&. record. were pros edfor

Causes of 142Nd Variation in Earth

NASA Astrophysics Data System (ADS)

Boyet, M.; Bouvier, A.; Gannoun, A.; Carlson, R.

2015-12-01

Variability of the 142Nd/144Nd ratio can reflect Sm/Nd fractionation during the lifetime of 146Sm, i.e. the first 500 Ma of Solar System history1 and nucleosynthetic heterogeneity inherited from the solar nebula. Deciphering the message carried by 142Nd variability requires a detailed examination of the data for Earth and meteorites. The elevated 142Nd/144Nd in terrestrial samples relative to average chondrites suggests that all terrestrial rocks sampled by volcanism over the Earth's history come from a geochemical reservoir characterized by a superchondritic Sm/Nd ratio. The chemical compliment to this reservoir, however, has never been seen, so it either was lost during Earth's accretion2,3, or is preserved in a deep hidden reservoir 1,4. These models are based on a comparison of Earth rocks and O-chondrites because they do not show any variation in stable Sm and Nd isotopic composition compared to Earth6-8. The first analyzed E-chondrites with terrestrial 142Nd/144Nd showed 144Sm excesses that reflect an excess p-process contribution. Although 142Nd is mainly produced by s-process, there is a direct p-process component estimated to be lower than 4 %. We will present new Sm and Nd isotopic data on meteoritic materials. CAIs show deficits in both r- and p-process isotopes that would lead to elevated 142Nd, yet the bulk C-chondrites in which they are contained show excesses in r-process isotopes and hence 142Nd/144Nd lower than terrestrial. The new E-chondrites data do not confirm the 142Nd-144Sm correlation observed in bulk chondrites In light of these results and using 146Sm-142Nd isochrons for constraining the bulk 142Nd/144Nd ratio of planetary bodies, we will discuss the 142Nd signature of terrestrial samples (from Hadean to present). 1Boyet & Carlson, Science 2005; 2O'Neill & Palme, Phil. Trans. R. Soc 2008; 3Caro et al. Nature 2008; 4Andreasen et al. EPSL 2008; 6Andreasen & Sharma, Science 2006; 7Carlson et al., Science 2007; 8Gannoun et al. PNAS 2011.

Controlled synthesis, characterization and photoluminescence property of olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Youjin, E-mail: zyj@ustc.edu.cn; Zheng, Ao; Yang, Xiaozhi

2012-09-15

Highlights: ► The olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was gained with EDTA assisted hydrothermal method. ► The product was characterized by XRD, XPS, FTIR, FESEM, and PL. ► The possible formation mechanism for olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was proposed. ► The PL in visible region of the olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was studied. -- Abstract: The olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was obtained by a convenient and facile complex agent assisted hydrothermal method. The product was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM) andmore » photoluminescence (PL). The possible formation mechanism of the olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was proposed. The photoluminescence property in visible region of the olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was studied.« less

Anomalous magnetoelastic behaviour near morphotropic phase boundary in ferromagnetic Tb{sub 1-x}Nd{sub x}Co{sub 2} system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murtaza, Adil; Yang, Sen, E-mail: yang.sen@mail.xjtu.edu.cn; Zhou, Chao

2016-08-01

In this work, we report a morphotropic phase boundary (MPB) involved ferromagnetic system Tb{sub 1-x}Nd{sub x}Co{sub 2} and reveal the corresponding structural and magnetoelastic properties of this system. With high resolution synchrotron X-ray diffractometry, the crystal structure of the TbCo{sub 2}-rich side is detected to be rhombohedral and that of NdCo{sub 2}-rich side is tetragonal below their respective Curie temperatures T{sub C}. The MPB composition Tb{sub 0.35}Nd{sub 0.65}Co{sub 2} corresponds to the coexistence of the rhombohedral phase (R-phase) and tetragonal phase (T-phase). Contrary to previously reported MPB involved ferromagnetic systems, the MPB composition of Tb{sub 0.35}Nd{sub 0.65}Co{sub 2} shows minimummore » magnetization which can be understood as compensation of sublattice moments between the R-phase and the T-phase. Furthermore, magnetostriction of Tb{sub 1-x}Nd{sub x}Co{sub 2} decreases with increasing Nd concentration until x = 0.8 and then increases in the negative direction with further increasing Nd concentration; the optimum point for magnetoelastic properties lies towards the rhombohedral phase. Our work not only shows an anomalous type of ferromagnetic MPB but also provides an effective way to design functional materials.« less

[Combined CO2 and Nd-YAG laser in neurosurgical practice. A 1st experience apropos of 40 intracranial procedures].

PubMed

Roux, F X; Leriche, B; Cioloca, C; Devaux, B; Turak, B; Nohra, G

1992-01-01

The authors present their experience concerning the use of Combolaser (Lasermatic, Finland), in neurosurgery. This laser-unit combines two wavelengths (CO2 and 1.06 Nd-YAG) which are emitted simultaneously and coaxially. During the last 12 months, 40 patients harbouring an intracranial tumor were operated upon with such a combolaser unit: 8 infra-tentorial, 32 supra-tentorial, 17 were meningiomas. The mean output power used during the procedures was 3-5 w for both CO2 and Nd-YAG beams. The authors discuss the advantages and inconveniences of such a laser; and they compare it with the other laser-units they have been using for the last 10 years: CO2-Laser, 1.06 Nd-YAG and 1.32 Nd-YAG laser. The main inconvenience of this unit is linked to the utilization of the articulated arm which conducts the CO2 laser beam. This drawback should be avoided or limited by the use of a fiber microguide, which will conduct both CO2 and Nd-YAG beams simultaneously. The principal contribution of a combined-laser unit is the quality of the haemostasis associated to a very good vaporization and cutting effect. When both wavelengths are synchronized, the combined laser beams penetrate into the nervous parenchyma more deeply than the only CO2 laser beam would with the same parameters. The vaporization effect is identical to that obtained with the isolated CO2 laser; the quality of haemostasis is limited to the effects of the Nd-YAG laser. Another advantage must be emphasized: the possibility of utilizing separately the CO2 laser and the 1.06 Nd-YAG.

Tannic acid alleviates bulk and nanoparticle Nd2O3 toxicity in pumpkin: a physiological and molecular response.

PubMed

Chen, Guangcai; Ma, Chuanxin; Mukherjee, Arnab; Musante, Craig; Zhang, Jianfeng; White, Jason C; Dhankher, Om Parkash; Xing, Baoshan

2016-11-01

The effect of dissolved organic matter (DOM) on nanoparticle toxicity to plants is poorly understood. In this study, tannic acid (TA) was selected as a DOM surrogate to explore the mechanisms of neodymium oxide NPs (Nd2O3 NPs) phytotoxicity to pumpkin (Cucurbita maxima). The results from the tested concentrations showed that 100 mg L(-1) Nd2O3 NPs were significantly toxic to pumpkin in term of fresh biomass, and the similar results from the bulk particles and the ionic treatments were also evident. Exposure to 100 mg L(-1) of Nd2O3 NPs and BPs in 1/5 strength Hoagland's solution not only significantly inhibited pumpkin growth, but also decreased the S, Ca, K and Mg levels in plant tissues. However, 60 mg L(-1) TA significantly moderated the observed phytotoxicity, decreased Nd accumulation in the roots, and notably restored S, Ca, K and Mg levels in NPs and BPs treated pumpkin. TA at 60 mg L(-1) increased superoxide dismutase (SOD) activity in both roots (17.5%) and leaves (42.9%), and catalase (CAT) activity (243.1%) in the roots exposed to Nd2O3 NPs. This finding was confirmed by the observed up-regulation of transcript levels of SOD and CAT in Nd2O3 NPs treated pumpkin analyzed by quantitative reverse transcription polymerase chain reaction. These results suggest that TA alleviates Nd2O3 BPs/NPs toxicity through alteration of the particle surface charge, thus reducing the contact and uptake of NPs by pumpkin. In addition, TA promotes antioxidant enzymatic activity by elevating the transcript levels of genes involved in ROS scavenging. Our results shed light on the mechanisms underlying the influence of DOM on the bioavailability and toxicity of NPs to terrestrial plants.

An Examination of Unsteady Airloads on a UH-60A Rotor: Computation Versus Measurement

NASA Technical Reports Server (NTRS)

Biedron, Robert T.; Lee-Rausch, Elizabeth

2012-01-01

An unsteady Reynolds-averaged Navier-Stokes solver for unstructured grids is used to simulate the flow over a UH-60A rotor. Traditionally, the computed pressure and shear stresses are integrated on the computational mesh at selected radial stations and compared to measured airloads. However, the corresponding integration of experimental data uses only the pressure contribution, and the set of integration points (pressure taps) is modest compared to the computational mesh resolution. This paper examines the difference between the traditional integration of computed airloads and an integration consistent with that used for the experimental data. In addition, a comparison of chordwise pressure distributions between computation and measurement is made. Examination of this unsteady pressure data provides new opportunities to understand differences between computation and flight measurement.

Evaluation of a Hand Washing Program for 2nd-Graders

ERIC Educational Resources Information Center

Tousman, Stuart; Arnold, Dani; Helland, Wealtha; Roth, Ruth; Heshelman, Nannatte; Castaneda, Oralia; Fischer, Emily; O'Neil, Kristen; Bileto, Stephanie

2007-01-01

The purpose of this project was to determine if a multiple-week learner-centered hand washing program could improve hand hygiene behaviors of 2nd-graders in a northern Illinois public school system. Volunteers from the Rockford Hand Washing Coalition went into 19 different classrooms for 4 consecutive weeks and taught a learner-centered program.…

Highly efficient passive mode locking of Nd:Lu2.9Gd0.1Al5O12 garnet crystal

NASA Astrophysics Data System (ADS)

Di, J. Q.; Xu, X. D.; Xia, C. T.; Tan, W. D.; Zhang, J.; Tang, D. Y.; Li, D. Z.; Zhou, D. H.; Wu, F.; Xu, J.

2013-05-01

Passive mode locking of Nd:Lu2.9Gd0.1Al5O12 (Nd:LuGdAG) crystal lasers was experimentally investigated. Stable mode-locked pulses with pulse widths as short as 9.7 ps were obtained for the Nd:LuGdAG crystal; the corresponding maximum output powers were 0.93 W while the mode-locked slope efficiencies were 43%, among the highest efficiencies ever reported for Nd3+ ps lasers. The results demonstrate that Nd:LuGdAG garnet crystal is a promising gain medium for efficient picosecond laser use.

Nd3+-doped TeO2-PbF2-AlF3 glasses for laser applications

NASA Astrophysics Data System (ADS)

Lalla, E. A.; Rodríguez-Mendoza, U. R.; Lozano-Gorrín, A. D.; Sanz-Arranz, A.; Rull, F.; Lavín, V.

2016-01-01

A study of the optical properties of Nd3+ ion in TeO2-PbF2-AlF3 glasses has been carried out for different Nd3+ concentrations. Based on the Judd-Ofelt theory, intensity parameters and radiative properties were determined from the absorption spectra. Focusing on the suitability of this host for laser applications, the spectroscopic quality factor χ was obtained with a value of 1.07, a value of the order of other compositions proposed as laser hosts. For the most intense emission corresponding with the 4F3/2 → 4I11/2 transition (1.06 μm), the absorption and emission and have been calculated with values of 1.20 × 10-20 cm2, 2.08 × 10-20 cm2. A positive value for the gain cross-sections has been found for a population inversion factor γ of 0.4 in the spectral range from 1060 to 1110 nm. All these results suggest the potentially use of this system as a laser host.

2nd International Gliomatosis Cerebri Working Group Conference | Center for Cancer Research

Cancer.gov

On June 22-23, the NIH hosted the 2nd Gliomatosis Cerebri International Conference that brought together leading neuro-oncologists, neuroscientists and families who have lost a child to the disease. Learn more...

View from east to west of PAR site storage building; ...

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

View from east to west of PAR site storage building; formerly PAR dispensary - Stanley R. Mickelsen Safeguard Complex, Storage Building, Across street from Family Housing Units 110 & 111, Nekoma, Cavalier County, ND

Effects of Nd:YAG and CO2 lasers on cerebral microvasculature. Study in normal rabbit brain.

PubMed

Kuroiwa, T; Tsuyumu, M; Takei, H; Inaba, Y

1986-01-01

The effect of Nd:YAG and CO2 laser beams on cerebral microvasculature was examined in experimental animals. Soft x-ray microangiography and histological examination of the brain after Nd:YAG laser exposure revealed broad avascular or oligovascular zones in the irradiated and the surrounding edematous tissue, in which the surviving vessels were narrowed and tapered without significant leakage of blood. After CO2 laser exposure, a wedge-shaped tissue defect surrounded by layers of charring, coagulation, and edema was observed. The main finding in the surrounding coagulation and edematous layers was dilatation of the vessels. Hemorrhage was sometimes observed, mainly in the edematous layer. These findings seem to explain the effective hemostatic capability of the Nd:YAG laser and the occasional hemorrhage following CO2 laser exposure, especially at high energy output.

Recycling and Mantle Stirring Determined by 142Nd/144Nd Isotopic Ratios

NASA Astrophysics Data System (ADS)

Jacobsen, S. B.; Ranen, M. C.

2004-12-01

It is now well established that 146Sm was live in the early solar system with an initial uniform 146Sm/144Sm ratio of ~0.008. Harper and Jacobsen (1992) discovered that a sample from Isua (~3.8 Ga old) had a positive 142Nd/144Nd anomaly of 33 ppm when compared to normal terrestrial and chondritic Nd. Furthermore, Jacobsen and Harper (1996) reported results from other Isua as well as Acasta (~4 Ga old) samples. Three other Isua samples had a possible small range (about -15 to +15), while two Acasta samples had no anomalies (normal to within 5 ppm). The presence of 142Nd anomalies at Isua has recently been confirmed by two other groups (Boyet et al. 2003; Caro et al. 2003). The available data demonstrate both the existence of early depleted mantle and that the early mantle was isotopically heterogeneous. As discussed by Jacobsen and Harper (1996), the recycling rate can be determined by tracing the decay of the average 142Nd/144Nd value of the depleted mantle. In addition, by using the 142Nd/144Nd heterogeneity in the depleted mantle through time we can determine the stirring rate of the mantle (Kellogg, Jacobsen and O'Connell, 2002) as a function of time. For this project our goal is to obtain a resolution in 142Nd/144Nd measurements of ~1 ppm. We have thus compared results obtained for the Nd isotope composition and 142Nd enriched standards for three different TIMS instruments: The Finnigan MAT 262 at Harvard, the Isoprobe-T and Finnigan TRITON mass spectrometers in GV Instrument's and Thermo Electron's demo laboratories in Manchester and Bremen, respectively. The Finnigan TRITON was designed in response to a request from the senior author for such an instrument. The results obtained so far demonstrate that all three instruments yield the same 142Nd/144Nd, 143Nd/144Nd and 145Nd/144Nd isotopic ratios to within a few ppm, while 148Nd/144Nd and 150Nd/144Nd ratios agree to within 10-20 ppm, when all ratios are normalized to 146Nd/144Nd using the exponential law. Due to

International Symposium on Halide Glasses (2nd) (Extended Abstracts).

DTIC Science & Technology

1983-08-05

of these materials. It is hoped that the atmosphere of the 1st Symposium will be maintained at the 2nd Symposium. The meeting will be held in a...purification of HfF4 and ZrFo by sublimation in a hydrogen fluoride atmosphere and purification of individual components and glasses by reactive atmosphere ...Tregoat and G. Fonteneau, U. Rennes, Rennes, France Reactive atmosphere processing developed by Mort Robinson at Hughes Research Labs. for the

58. MILL BUILDING (BUILDING 1558): VIEW FROM SOUTHWEST, WITH V2 ...

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

58. MILL BUILDING (BUILDING 1558): VIEW FROM SOUTHWEST, WITH V-2 ASSEMBLY BUILDING IN BACKGROUND AT FAR RIGHT - White Sands Missile Range, V-2 Rocket Facilities, Near Headquarters Area, White Sands, Dona Ana County, NM

56. V2 ASSEMBLY BUILDING (BUILDING 1538): VIEW FROM NORTHEAST, WITH ...

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

56. V-2 ASSEMBLY BUILDING (BUILDING 1538): VIEW FROM NORTHEAST, WITH MILL BUILDING IN BACKGROUND AT FAR RIGHT - White Sands Missile Range, V-2 Rocket Facilities, Near Headquarters Area, White Sands, Dona Ana County, NM

Defining Simple nD Operations Based on Prosmatic nD Objects

NASA Astrophysics Data System (ADS)

Arroyo Ohori, K.; Ledoux, H.; Stoter, J.

2016-10-01

An alternative to the traditional approaches to model separately 2D/3D space, time, scale and other parametrisable characteristics in GIS lies in the higher-dimensional modelling of geographic information, in which a chosen set of non-spatial characteristics, e.g. time and scale, are modelled as extra geometric dimensions perpendicular to the spatial ones, thus creating a higher-dimensional model. While higher-dimensional models are undoubtedly powerful, they are also hard to create and manipulate due to our lack of an intuitive understanding in dimensions higher than three. As a solution to this problem, this paper proposes a methodology that makes nD object generation easier by splitting the creation and manipulation process into three steps: (i) constructing simple nD objects based on nD prismatic polytopes - analogous to prisms in 3D -, (ii) defining simple modification operations at the vertex level, and (iii) simple postprocessing to fix errors introduced in the model. As a use case, we show how two sets of operations can be defined and implemented in a dimension-independent manner using this methodology: the most common transformations (i.e. translation, scaling and rotation) and the collapse of objects. The nD objects generated in this manner can then be used as a basis for an nD GIS.

21. Perimeter acquisition radar building room #200, electrical equipment room ...

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

21. Perimeter acquisition radar building room #200, electrical equipment room - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Blade Displacement Predictions for the Full-Scale UH-60A Airloads Rotor

NASA Technical Reports Server (NTRS)

Bledron, Robert T.; Lee-Rausch, Elizabeth M.

2014-01-01

An unsteady Reynolds-Averaged Navier-Stokes solver for unstructured grids is loosely coupled to a rotorcraft comprehensive code and used to simulate two different test conditions from a wind-tunnel test of a full-scale UH-60A rotor. Performance data and sectional airloads from the simulation are compared with corresponding tunnel data to assess the level of fidelity of the aerodynamic aspects of the simulation. The focus then turns to a comparison of the blade displacements, both rigid (blade root) and elastic. Comparisons of computed root motions are made with data from three independent measurement systems. Finally, comparisons are made between computed elastic bending and elastic twist, and the corresponding measurements obtained from a photogrammetry system. Overall the correlation between computed and measured displacements was good, especially for the root pitch and lag motions and the elastic bending deformation. The correlation of root lead-lag motion and elastic twist deformation was less favorable.

Magnetocaloric effect in layered NdMn2Ge0.4Si1.6

NASA Astrophysics Data System (ADS)

Wang, J. L.; Campbell, S. J.; Cadogan, J. M.; Studer, A. J.; Zeng, R.; Dou, S. X.

2011-06-01

A giant magnetocaloric effect has been observed in NdMn2Ge0.4Si1.6 associated with the first-order magnetic phase transition from antiferromagnetism to ferromagnetism around TC=36K. The magnetic entropy change -ΔSM and adiabatic temperature change ΔTad have been determined from magnetization and specific heat measurements (B =0-5 T) with -ΔSM calculated by the Maxwell relation and Clausius-Clapeyron method. The values -ΔSMmax=12.3 J kg-1 K-1 and refrigerant capacity ˜95 J/kg for ΔB =0-2 T as derived from the Maxwell relation, together with the small hysteresis (thermal <0.5 K; magnetic field <0.1 T), indicate the potential of NdMn2Ge0.4Si1.6 for refrigeration applications.

Loads Correlation of a Full-Scale UH-60A Airloads Rotor in a Wind Tunnel

NASA Technical Reports Server (NTRS)

Yeo, Hyeonsoo; Romander, Ethan A.

2012-01-01

Wind tunnel measurements of the rotor trim, blade airloads, and structural loads of a full-scale UH-60A Black Hawk main rotor are compared with calculations obtained using the comprehensive rotorcraft analysis CAMRAD II and a coupled CAMRAD II/OVERFLOW 2 analysis. A speed sweep at constant lift up to an advance ratio of 0.4 and a thrust sweep at constant speed into deep stall are investigated. The coupled analysis shows significant improvement over comprehensive analysis. Normal force phase is better captured and pitching moment magnitudes are better predicted including the magnitude and phase of the two stall events in the fourth quadrant at the deeply stalled condition. Structural loads are, in general, improved with the coupled analysis, but the magnitude of chord bending moment is still significantly underpredicted. As there are three modes around 4 and 5/rev frequencies, the structural responses to the 5/rev airloads due to dynamic stall are magnified and thus care must be taken in the analysis of the deeply stalled condition.

Binder Jetting: A Novel NdFeB Bonded Magnet Fabrication Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paranthaman, M. Parans; Shafer, Christopher S.; Elliott, Amy M.

2016-04-05

Our goal of this research is to fabricate near-net-shape isotropic (Nd) 2Fe 14B-based (NdFeB) bonded magnets using a three dimensional printing process to compete with conventional injection molding techniques used for bonded magnets. Additive manufacturing minimizes the waste of critical materials and allows for the creation of complex shapes and sizes. The binder jetting process works similarly to an inkjet printer. A print-head passes over a bed of NdFeB powder and deposits a polymer binding agent to bind the layer of particles together. The bound powder is then coated with another layer of powder, building the desired shape in successivemore » layers of bonded powder. Upon completion, the green part and surrounding powders are placed in an oven at temperatures between 100°C and 150°C for 4–6 h to cure the binder. After curing, the excess powder can be brushed away to reveal the completed “green” part. Green magnet parts were then infiltrated with a clear urethane resin to achieve the measured density of the magnet of 3.47 g/cm 3 close to 46% relative to the NdFeB single crystal density of 7.6 g/cm 3. Magnetic measurements indicate that there is no degradation in the magnetic properties. In conclusion, this study provides a new pathway for preparing near-net-shape bonded magnets for various magnetic applications.« less

Nd-doped Bi2O3 nanocomposites: simple synthesis and improved photocatalytic activity for hydrogen production under visible light

NASA Astrophysics Data System (ADS)

Al-Namshah, Khadijah S.; Mohamed, Reda M.

2018-04-01

Bi2O3 has 2.4 eV band gap energy, which means it absorb in visible region. Though the photocatalytic activity of Bi2O3 is extremely little due to rapid rate of photogenerated electron-hole recombination. To face the economical and practical needs, the photocatalytic efficiency of Bi2O3 should be upgraded. In this paper, this was achieved by addition of neodymium to Bi2O3 nanosheets and Nd/Bi2O3 nanocomposites were prepared by a easy process at room temperature using a surfactant of Pluronic F127. The Bi2O3 nanosheets and Nd/Bi2O3 nanocomposites were investigated by many tools. The photocatalytic activity of Nd/Bi2O3 samples is better than Bi2O3 due to reduced band gap and reduced electron-hole recombination of Bi2O3 with addition of neodymium. In addition, Nd/Bi2O3 nanocomposites exhibit photocatalytic stability for hydrogen production which enables it to be reused on other occasions also.

Probing structural changes in Ca(1-x)Nd2x/3TiO3 ceramics by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Lowndes, Robert; Deluca, Marco; Azough, Feridoon; Freer, Robert

2013-01-01

Ceramics in the system Ca(1-x)Nd2x/3TiO3, intended for mobile communication applications, exhibit grossly non-linear variations in microwave dielectric properties with composition. There is evidence of a structural transition and the formation of vacancies on the A-site of the perovskite structure. High density, single phase perovskite Ca(1-x)Nd2x/3TiO3 ceramics have been prepared by the mixed oxide route. Raman spectroscopy was used to investigate the structural variations, which impact on dielectric properties. The Raman spectra show that with increasing Nd content, there is a transition from an ordered structure, to a disordered arrangement of cations and vacancies, and back to an ordered arrangement in Ca0.1Nd0.6TiO3. A structural phase transition from orthorhombic Pbnm to monoclinic C2/m coincides with the order-disorder transition at Ca0.1Nd0.6TiO3. Polarized Raman spectroscopy facilitated the assignment of the Raman modes and investigation of the role of importance of domain structures. Large variation in the plane angles was attributed to differences in domain structures. Differences in the angular dependence of the Raman modes with Nd content reflect changes in the preferred orientation of the domains from lamellar twins, to wedge shaped and back to lamellar twins.

Bond-selective photodissociation of partially deuterated ammonia molecules: Photodissociations of vibrationally excited NHD2 in the 5νNH state and NH2D in the 5νND state

NASA Astrophysics Data System (ADS)

Akagi, Hiroshi; Yokoyama, Keiichi; Yokoyama, Atsushi

2004-03-01

Ultraviolet photodissociation of NHD2 excited to the fourth overtone state of the NH stretching mode (5νNH) and NH2D excited to that of the ND stretching mode (5νND) has been investigated by using a crossed laser and molecular beams method. Branching ratio between the NH and ND bond dissociations has been determined by utilizing a (2+1) resonance enhanced multiphoton ionization scheme of H and D atoms. For the photolysis of NHD2 in the 5νNH state, the NH dissociation cross section is 5.1±1.4 times as large as the ND dissociation cross section per bond. On the other hand, for the photolysis of NH2D in the 5νND state, the ratio of the NH dissociation cross section per bond to the ND dissociation cross section decreases to 0.68±0.16. In comparison with the branching ratios for the photolysis of vibrationally unexcited NH2D and NHD2 [Koda and Back, Can. J. Chem. 55, 1380 (1977)], the present results indicate that the excitation of the NH stretching mode enhances the NH dissociation with ca. two times larger NH/ND branching ratio, whereas the excitation of the ND stretching mode results in the preferential ND dissociation with ca. 3-4 times larger ND/NH branching ratio than that for the vibrational ground states. The mechanism of the bond-selective enhancement has been discussed in terms of the energetics and dynamics of wave packet.

35. Perimeter acquisition radar building room #325, showing hard disc ...

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

35. Perimeter acquisition radar building room #325, showing hard disc drive - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Magnetic Force Microscopy Investigation of Magnetic Domains in Nd2Fe14B

NASA Astrophysics Data System (ADS)

Talari, Mahesh Kumar; Markandeyulu, G.; Rao, K. Prasad

2010-07-01

Remenance and coercivity in Nd2Fe14B materials are strongly dependent on the microstructural aspects like phases morphology and grain size. The coercivity (Hc) of a magnetic material varies inversely with the grain size (D) and there is a critical size below which Hc∝D6. Domain wall pinning by grain boundaries and foreign phases is the important mechanism in explaining the improvement in coercivity and remenance. Nd2Fe14B intermetallic compound with stochiometric composition was prepared from pure elements (Nd -99.5%, Fe—99.95%, B -99.99%) by arc melting in argon atmosphere. Magnetic Force Microscope (MFM) gives high-resolution magnetic domain structural information of ferromagnetic samples. DI-3100 Scanning Probe Microscope with MESP probes was used For MFM characterization of the samples. Magnetic domains observed in cast ingots were very long (up to 40 μm were observed) and approximately 1-5 μm wide due to high anisotropy of the compounds. Magnetic domains have displayed different image contrast and morphologies at different locations of the samples. The domain morphologies and image contrast obtained in this analysis were explained in this paper.

Structural and magnetic properties of RTiNO{sub 2} (R=Ce, Pr, Nd) perovskite nitride oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porter, Spencer H.; Huang, Zhenguo, E-mail: zhenguo@uow.edu.au; Cheng, Zhenxiang

2015-03-15

Neutron powder diffraction indicates that CeTiNO{sub 2} and PrTiNO{sub 2} crystallize with orthorhombic Pnma symmetry (Ce: a=5.5580(5), b=7.8369(7), and c=5.5830(4) Å; Pr: a=5.5468(5), b=7.8142(5), and c=5.5514(5) Å) as a result of a{sup –}b{sup +}a{sup –} tilting of the titanium-centered octahedra. Careful examination of the NPD data, confirms the absence of long range anion order in both compounds, while apparent superstructure reflections seen in electron diffraction patterns provide evidence for short range anion order. Inverse magnetic susceptibility plots reveal that the RTiNO{sub 2} (R=Ce, Pr, Nd) compounds are paramagnetic with Weiss constants that vary from −28 to −42 K. Effective magneticmore » moments for RTiNO{sub 2} (R=Ce, Pr, Nd) are 2.43 μ{sub B}, 3.63 μ{sub B}, and 3.47 μ{sub B}, respectively, in line with values expected for free rare-earth ions. Deviations from Curie–Weiss behavior that occur below 150 K for CeTiNO{sub 2} and below 30 K for NdTiNO{sub 2} are driven by magnetic anisotropy, spin–orbit coupling, and crystal field effects. - Graphical abstract: The structure and magnetism of the oxide nitride perovskites RTiNO{sub 2} (R=Ce, Pr, Nd) have been explored. The average symmetry is shown to be Pnma with a random distribution of oxide and nitride ions and a{sup −}b{sup +}a{sup −} tilting of the titanium-centered octahedra, but electron diffraction shows evidence for short range anion order. All three compounds are paramagnetic but deviations from the Curie Weiss law are seen below 150 K for R=Ce and below 30 K for R=Nd. - Highlights: • The oxide nitride perovskites RTiNO{sub 2} (R=Ce, Pr) have been prepared and their structures determined. • Diffraction measurements indicate short range cis-order of O and N, but no long range order. • Compounds are paramagnetic with Weiss constants that vary from −28 to −42 K. • CeTiO{sub 2}N and NdTiO{sub 2}N deviate from Curie–Weiss behavior below 150 and 30 K

Ground shake test of the UH-60A helicopter airframe and comparison with NASTRAN finite element model predictions

NASA Technical Reports Server (NTRS)

Howland, G. R.; Durno, J. A.; Twomey, W. J.

1990-01-01

Sikorsky Aircraft, together with the other major helicopter airframe manufacturers, is engaged in a study to improve the use of finite element analysis to predict the dynamic behavior of helicopter airframes, under a rotorcraft structural dynamics program called DAMVIBS (Design Analysis Methods for VIBrationS), sponsored by the NASA-Langley. The test plan and test results are presented for a shake test of the UH-60A BLACK HAWK helicopter. A comparison is also presented of test results with results obtained from analysis using a NASTRAN finite element model.

Photocatalytic Water Splitting for O2 Production under Visible Light Irradiation Using NdVO4-V2O5 Hybrid Powders

PubMed Central

Chiang, Tzu Hsuan; Chen, Tso-Ming

2017-01-01

The study investigated photocatalytic water splitting for O2 production under visible light irradiation using neodymium vanadium oxide (NdVO4) and vanadium oxide (V2O5) hybrid powders. The results in a sacrificial agent of 0.01 M AgNO3 solution were obtained, and the highest photocatalytic O2 evolution was 2.63 μmol/h, when the hybrid powders were prepared by mixing Nd and V at a volume ratio of 1:3 at a calcination temperature of 350 °C for 1 h. The hybrid powders were synthesized by neodymium nitrate and ammonium metavanadate using the glycothermal method in ethylene glycol at 120 °C for 1 h. The hybrid powders consisted of two shapes, NdVO4 nanoparticles and the cylindrical V2O5 particles, and they possessed the ability for photocatalytic oxygen (O2) evolution during irradiation with visible light. The band gaps and structures of the hybrid powders were analyzed using UV-visible spectroscopy and transmission electron microscopy. PMID:28772692

Efficient laser operation of Nd3+:Lu2O3 at various wavelengths between 917 nm and 1463 nm

NASA Astrophysics Data System (ADS)

von Brunn, P.; Heuer, A. M.; Fornasiero, L.; Huber, G.; Kränkel, C.

2016-08-01

Even though the first Nd3+-doped sesquioxide lasers have been realized more than 50 years ago, up to now no reports on efficient laser operation of Nd3+:doped sesquioxides can be found. In this work, we review the favorable spectroscopic properties of the sesquioxide Nd3+:Lu2O3 in terms of ground state absorption, stimulated emission, and excited state absorption cross sections as well as the upper level lifetime. Making use of these properties, we achieved efficient laser performance on eight different laser transitions in the wavelength range between 917 nm and 1463 nm under Ti:sapphire laser pumping using state-of-the-art HEM-grown Nd3+:Lu2O3 crystals with good optical quality. At the strongest transition around 1076 nm we determined a slope efficiency of 69%, which represents the highest efficiency ever obtained for a Nd3+-doped sesquioxide. Furthermore, we could generate watt level output powers and high slope efficiencies for seven other transitions. Lasers at 917 nm, 1053 nm, 1108 nm and 1463 nm were realized for the first time and the latter represents one of the longest laser wavelengths obtained on the 4F3/2  →  4I13/2 transition in Nd3+-doped materials.

Characterization of a fused protein specified by the adenovirus type 2-simian virus 40 hybrid Ad2+ND1 dp2.

PubMed Central

Fey, G; Lewis, J B; Grodzicker, T; Bothwell, A

1979-01-01

The adenovirus type 2-simian virus 40 (SV40) hybrid virus Ad2+ND1 dp2 (E. Lukanidin, manuscript in preparation) specified two proteins (molecular weights, 24,000 and 23,000) that are, in part, products of an insertion of SV40 early DNA sequences. This was demonstrated by translation in vitro from viral mRNA that had been selected by hybridization to SV40 DNA. These two phosphorylated, nonvirion proteins were produced late in infection in amounts similar to adenovirus 2 structural proteins and were closely related to each other in tryptic peptide composition. The portion of SV40 DNA (map units 0.17 to 0.22 on the SV40 genome) coding for these proteins was joined to sequences coding for the amino-terminal part of the adenovirus type 2 structural protein IV (fiber). The Ad2+ND1 dp2 23,000- and 24,000-molecular-weight proteins were hybrid polypeptides, with about two-thirds of their tryptic peptides contributed by the fiber protein and the remainder contributed by SV40 T-antigen. They shared with T-antigen (molecular weight, 96,000) a carboxy-terminal proline-rich tryptic peptide. Together, the tryptic peptide composition of these proteins and the known SV40 DNA sequences suggested the reading frame for the translation of T-antigen. The carboxy terminus for T-anigen would then be located on the SV40 genome map next to the TAA terminator triplet at position 0.175, 910 bases away from the cleavage site of the restriction endonuclease EcoRI. Seven host range mutants from Ad2+ND1 dp2 were isolated that had lost the capacity to propagate on monkey cells. They did not induce detectable levels of the hybrid proteins. Three of these mutants had lost the SV40 DNA insertion that codes in part for these proteins. Thus, in analogy to the Ad2+ND1 30,000-molecular-weight protein, the presence of these proteins correlates with the presence of the helper function for adenovirus replication on monkey cells. Images PMID:225516

Application of statistical shape analysis for the estimation of bone and forensic age using the shapes of the 2nd, 3rd, and 4th cervical vertebrae in a young Japanese population.

PubMed

Rhee, Chang-Hoon; Shin, Sang Min; Choi, Yong-Seok; Yamaguchi, Tetsutaro; Maki, Koutaro; Kim, Yong-Il; Kim, Seong-Sik; Park, Soo-Byung; Son, Woo-Sung

2015-12-01

From computed tomographic images, the dentocentral synchondrosis can be identified in the second cervical vertebra. This can demarcate the border between the odontoid process and the body of the 2nd cervical vertebra and serve as a good model for the prediction of bone and forensic age. Nevertheless, until now, there has been no application of the 2nd cervical vertebra based on the dentocentral synchondrosis. In this study, statistical shape analysis was used to build bone and forensic age estimation regression models. Following the principles of statistical shape analysis and principal components analysis, we used cone-beam computed tomography (CBCT) to evaluate a Japanese population (35 males and 45 females, from 5 to 19 years old). The narrowest prediction intervals among the multivariate regression models were 19.63 for bone age and 2.99 for forensic age. There was no significant difference between form space and shape space in the bone and forensic age estimation models. However, for gender comparison, the bone and forensic age estimation models for males had the higher explanatory power. This study derived an improved objective and quantitative method for bone and forensic age estimation based on only the 2nd, 3rd and 4th cervical vertebral shapes. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Scoping analysis of the Advanced Test Reactor using SN2ND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolters, E.; Smith, M.; SC)

2012-07-26

A detailed set of calculations was carried out for the Advanced Test Reactor (ATR) using the SN2ND solver of the UNIC code which is part of the SHARP multi-physics code being developed under the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program in DOE-NE. The primary motivation of this work is to assess whether high fidelity deterministic transport codes can tackle coupled dynamics simulations of the ATR. The successful use of such codes in a coupled dynamics simulation can impact what experiments are performed and what power levels are permitted during those experiments at the ATR. The advantages of themore » SN2ND solver over comparable neutronics tools are its superior parallel performance and demonstrated accuracy on large scale homogeneous and heterogeneous reactor geometries. However, it should be noted that virtually no effort from this project was spent constructing a proper cross section generation methodology for the ATR usable in the SN2ND solver. While attempts were made to use cross section data derived from SCALE, the minimal number of compositional cross section sets were generated to be consistent with the reference Monte Carlo input specification. The accuracy of any deterministic transport solver is impacted by such an approach and clearly it causes substantial errors in this work. The reasoning behind this decision is justified given the overall funding dedicated to the task (two months) and the real focus of the work: can modern deterministic tools actually treat complex facilities like the ATR with heterogeneous geometry modeling. SN2ND has been demonstrated to solve problems with upwards of one trillion degrees of freedom which translates to tens of millions of finite elements, hundreds of angles, and hundreds of energy groups, resulting in a very high-fidelity model of the system unachievable by most deterministic transport codes today. A space-angle convergence study was conducted to determine the meshing and angular cubature

Detached Eddy Simulation of the UH-60 Rotor Wake Using Adaptive Mesh Refinement

NASA Technical Reports Server (NTRS)

Chaderjian, Neal M.; Ahmad, Jasim U.

2012-01-01

Time-dependent Navier-Stokes flow simulations have been carried out for a UH-60 rotor with simplified hub in forward flight and hover flight conditions. Flexible rotor blades and flight trim conditions are modeled and established by loosely coupling the OVERFLOW Computational Fluid Dynamics (CFD) code with the CAMRAD II helicopter comprehensive code. High order spatial differences, Adaptive Mesh Refinement (AMR), and Detached Eddy Simulation (DES) are used to obtain highly resolved vortex wakes, where the largest turbulent structures are captured. Special attention is directed towards ensuring the dual time accuracy is within the asymptotic range, and verifying the loose coupling convergence process using AMR. The AMR/DES simulation produced vortical worms for forward flight and hover conditions, similar to previous results obtained for the TRAM rotor in hover. AMR proved to be an efficient means to capture a rotor wake without a priori knowledge of the wake shape.

30. Perimeter acquisition radar building room #318, showing radar control. ...

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

30. Perimeter acquisition radar building room #318, showing radar control. Console and line printers - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Magnesium-dependent association and folding of oligonucleosomes reconstituted with ubiquitinated H2A.

PubMed

Jason, L J; Moore, S C; Ausio, J; Lindsey, G

2001-05-04

The MgCl2-induced folding of defined 12-mer nucleosomal arrays, in which ubiquitinated histone H2A (uH2A) replaced H2A, was analyzed by quantitative agarose gel electrophoresis and analytical centrifugation. Both types of analysis showed that uH2A arrays attained a degree of compaction similar to that of control arrays in 2 mM MgCl2. These results indicate that attachment of ubiquitin to H2A has little effect on the ability of nucleosomal arrays to form higher order folded structures in the ionic conditions tested. In contrast, uH2A arrays were found to oligomerize at lower MgCl2 concentrations than control nucleosomal arrays, suggesting that histone ubiquitination may play a role in nucleosomal fiber association.

1. View from missile site control building (southeast to northwest) ...

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

1. View from missile site control building (southeast to northwest) of universal missile building. Note earth mounding. On the far right can be seen the exit tunnel; the small "boxes" on top are the roof ventilators. This building was salvaged and sealed after site inactivation - Stanley R. Mickelsen Safeguard Complex, Universal Missile Building, Between Tactical Road South & Patrol Road, Nekoma, Cavalier County, ND

Effects of thickness and annealing condition on magnetic properties and thermal stabilities of Ta/Nd/NdFeB/Nd/Ta sandwiched films

NASA Astrophysics Data System (ADS)

Liu, Wen-Feng; Zhang, Min-Gang; Zhang, Ke-Wei; Zhang, Hai-Jie; Xu, Xiao-Hong; Chai, Yue-Sheng

2016-11-01

Ta/Nd/NdFeB/Nd/Ta sandwiched films are deposited by magnetron sputtering on Si (100) substrates, and subsequently annealed in vacuum at different temperatures for different time. It is found that both the thickness of NdFeB and Nd layer and the annealing condition can affect the magnetic properties of Ta/Nd/NdFeB/Nd/Ta films. Interestingly, the thickness and annealing temperature show the relevant behaviors that can affect the magnetic properties of the film. The high coercivity of 24.1 kOe (1 Oe = 79.5775 A/m) and remanence ratio (remanent magnetization/saturation magnetization) of 0.94 can be obtained in a Ta/Nd(250 nm)/NdFeB(600 nm)/Nd(250 nm)/Ta film annealed for 3 min at 1023 K. In addition, the thermal stability of the film is also linked to the thickness of NdFeB and Nd layer and the annealing temperature as well. The excellent thermal stability can be achieved in a Ta/Nd(250 nm)/NdFeB(600 nm)/Nd(250 nm)/Ta film annealed at 1023 K. Program supported by the National Natural Science Foundation of China (Grant No. 51305290), the Higher Education Technical Innovation Project of Shanxi Province, China (Grant No. 2013133), the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals of Shanxi Province, China (Grant No. 2015003), and the Program for the Key Team of Scientific and Technological Innovation of Shanxi Province, China (Grant No. 2013131009).

X-ray absorption studies of gamma irradiated Nd doped phosphate glass

NASA Astrophysics Data System (ADS)

Rai, V. N.; Rajput, Parasmani; Jha, S. N.; Bhattacharyya, D.

2015-06-01

This paper presents the X-ray absorption near edge structure (XANES) studies of Nd doped phosphate glasses before and after gamma irradiation. The intensity and location of LIII edge white line peak of Nd changes depending on its concentration as well as on the ratio of O/Nd in the glass matrix. The decrease in the peak intensity of white line after gamma irradiation indicates towards reduction of Nd3+ to Nd2+ in the glass matrix, which increases with an increase in the doses of gamma irradiation. Similarity in the XANES spectra of Nd doped phosphate glasses and Nd2O3 suggests that coordination geometry around Nd3+ in glass samples may be identical to that of Nd2O3.

2. Building 22 south elevation oblique. Ghost of Building 22A ...

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

2. Building 22 south elevation oblique. Ghost of Building 22A visible on south elevation. South elevation of Building 22A in foreground. View looking NW. - John & James Dobson Carpet Mill (West Parcel), Building No. 22, 4041-4055 Ridge Avenue, Philadelphia, Philadelphia County, PA

Induced emission cross section of a possible laser line in Nd:Y2O3 ceramics at 1.095 μm

NASA Astrophysics Data System (ADS)

Fukabori, Akihiro; Sekita, Masami; Ikegami, Takayasu; Iyi, Nobuo; Komatsu, Toshiki; Kawamura, Masayuki; Suzuki, Makoto

2007-02-01

In this study, we measured the change of the optical transmittance for calcination temperatures, in steps of 10°, at two different sintering temperatures. It was found that the optical transmittance is highly dependent on the calcination temperature. The highest optical transmittance obtained was 70% for the transparent Y2O3 (yttria) ceramics produced without the use of additives and high injection presure in this study, higher than the highest reported value of 65%. Optical absorption and emission spectra of Nd :Y2O3 obtained from a low temperature synthesis process were measured. The energy level structure of Nd3+ in the Y2O3 ceramics was determined for a 1mol% Nd concentration. The induced emission cross section was calculated to be in the range of 3.2×10-19-1.1×10-17cm2 for the 1mol% Nd-doped Y2O3 ceramics. Furthermore, a laser line possibly has been identified in this study, in the Nd :Y2O3 ceramic at 1.095μm.

2. Overview of Buildings 2015, 2133 and 2009, with Building ...

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

2. Overview of Buildings 2015, 2133 and 2009, with Building 1001 (administration building) in background, looking northeast - Naval Air Station Chase Field, Texas State Highway 202, 4.8 miles east of intersection of Texas State Highway 202 & U.S. State Highway 181, Beeville, Bee County, TX

Solvothermal synthesis and structure of 3D frameworks of Nd(III) and Y(III) with thiophene-2,5-dicarboxylate and N,N‧-diethylformamide

NASA Astrophysics Data System (ADS)

Sharma, Swati; Yawer, Mohd; Kariem, Mukaddus; Sheikh, Haq Nawaz

2016-08-01

Two new 3D MOFs [Nd2(TDA)3(DEF)2(H2O)]n (1) and [Y4(TDA)6(DEF)4]n (2) [Thiophene-2,5-dicarboxylic acid (H2TDA) and N,N‧-diethylformamide (DEF)] were synthesized by solvothermal method. They were characterized by elemental analyses, infrared spectroscopy and single crystal X-ray diffraction studies. The two MOFs (1) and (2) belong to the monoclinic system with space group P21/n and C 2 respectively. Structural characterizations by single-crystal X-ray crystallography reveal that 1 and 2 adopt three-dimensional frameworks constructed by cross-linking of rod shaped infinite chain secondary building unit (SBU) by thiophene-2,5-dicarboxylates as linker. These frameworks feature rhomboidal channels, inside which coordinated DEF/H2O solvent molecules are located. DEF plays pivotal role in reaction and design of MOFs. Thermogravimetric analysis shows that both MOFs are thermally robust.

Refraction data survey: 2nd generation correlation of myopia.

PubMed

Greene, Peter R; Medina, Antonio

2016-10-01

The objective herein is to provide refraction data, myopia progression rate, prevalence, and 1st and 2nd generation correlations, relevant to whether myopia is random or inherited. First- and second-generation ocular refraction data are assembled from N = 34 families, average of 2.8 children per family. From this group, data are available from N = 165 subjects. Inter-generation regressions are performed on all the data sets, including correlation coefficient r, and myopia prevalence [%]. Prevalence of myopia is [M] = 38.5 %. Prevalence of high myopes with |R| >6 D is [M-] = 20.5 %. Average refraction is  = -1.84 D ± 3.22 (N = 165). For the high myopes, |R| >6 D, prevalence for the parents is [M-] = 25 %, for the 2nd generation [M-] = 16.5 %. Average myopia level for the high myopes, both generations, is  = -7.52 D ± 1.31 D (N = 33). Regression parameters are calculated for all the data sets, yielding correlation coefficients in the range r = 0.48-0.72 for some groups of myopes and high myopes, fathers to daughters, and mothers to sons. Also of interest, some categories show essentially no correlation, -0.20 < r < 0.20, indicating that the refractive errors occur randomly. Time series results show myopia diopter rates = -0.50 D/year.