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Sample records for air core transformer

  1. Power supply with air core transformer and seperated power supplies for high dynamic range

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Aalami, Dean (Inventor); Darrach, Murray (Inventor); Orient, Otto (Inventor)

    2001-01-01

    A power supply for a quadrupole mass spectrometer which operates using an RF signal. The RF signal is controllable via a feedback loop. The feedback loop is from the output, through a comparator, and compared to a digital signal. An air core transformer is used to minimize the weight. The air core transformer is driven via two out of phase sawtooth signals which drive opposite ends of the transformer.

  2. Banded transformer cores

    NASA Technical Reports Server (NTRS)

    Mclyman, C. W. T. (Inventor)

    1974-01-01

    A banded transformer core formed by positioning a pair of mated, similar core halves on a supporting pedestal. The core halves are encircled with a strap, selectively applying tension whereby a compressive force is applied to the core edge for reducing the innate air gap. A dc magnetic field is employed in supporting the core halves during initial phases of the banding operation, while an ac magnetic field subsequently is employed for detecting dimension changes occurring in the air gaps as tension is applied to the strap.

  3. Computation of the Mutual Inductance between Air-Cored Coils of Wireless Power Transformer

    NASA Astrophysics Data System (ADS)

    Anele, A. O.; Hamam, Y.; Chassagne, L.; Linares, J.; Alayli, Y.; Djouani, K.

    2015-09-01

    Wireless power transfer system is a modern technology which allows the transfer of electric power between the air-cored coils of its transformer via high frequency magnetic fields. However, due to its coil separation distance and misalignment, maximum power transfer is not guaranteed. Based on a more efficient and general model available in the literature, rederived mathematical models for evaluating the mutual inductance between circular coils with and without lateral and angular misalignment are presented. Rather than presenting results numerically, the computed results are graphically implemented using MATLAB codes. The results are compared with the published ones and clarification regarding the errors made are presented. In conclusion, this study shows that power transfer efficiency of the system can be improved if a higher frequency alternating current is supplied to the primary coil, the reactive parts of the coils are compensated with capacitors and ferrite cores are added to the coils.

  4. Off-resonance frequency operation for power transfer in a loosely coupled air core transformer

    DOEpatents

    Scudiere, Matthew B

    2012-11-13

    A power transmission system includes a loosely coupled air core transformer having a resonance frequency determined by a product of inductance and capacitance of a primary circuit including a primary coil. A secondary circuit is configured to have a substantially same product of inductance and capacitance. A back EMF generating device (e.g., a battery), which generates a back EMF with power transfer, is attached to the secondary circuit. Once the load power of the back EMF generating device exceeds a certain threshold level, which depends on the system parameters, the power transfer can be achieved at higher transfer efficiency if performed at an operating frequency less than the resonance frequency, which can be from 50% to 95% of the resonance frequency.

  5. Static voltage distribution between turns of secondary winding of air-core spiral strip transformer and its application

    NASA Astrophysics Data System (ADS)

    Zhang, Hong-bo; Liu, Jin-liang; Cheng, Xin-bing; Zhang, Yu

    2011-09-01

    The static voltage distribution between winding turns has great impact on output characteristics and lifetime of the air-core spiral strip pulse transformer (ACSSPT). In this paper, winding inductance was calculated by electromagnetic theory, so that the static voltage distribution between turns of secondary winding of ACSSPT was analyzed conveniently. According to theoretical analysis, a voltage gradient because of the turn-to-turn capacitance was clearly noticeable across the ground turns. Simulation results of Pspice and CST EM Studio codes showed that the voltage distribution between turns of secondary winding had linear increments from the output turn to the ground turn. In experiment, the difference in increased voltage between the ground turns and the output turns of a 20-turns secondary winding is almost 50%, which is believed to be responsible for premature breakdown of the insulation, particularly between the ground turns. The experimental results demonstrated the theoretical analysis and simulation results, which had important value for stable and long lifetime ACSSPT design. A new ACSSPT with improved structure has been used successfully in intense electron beam accelerators steadily.

  6. The Learning-Focused Transformation of Biology and Physics Core Courses at the U.S. Air Force Academy

    ERIC Educational Resources Information Center

    Sagendorf, Kenneth; Noyd, Robert K.; Morris, D. Brent

    2009-01-01

    An institution-wide focus on deep learning has made significant changes in the biology and physics core course curriculum at the U.S. Air Force Academy. The biology course director has reworked course objectives to reflect the learning-focused approach to teaching, while the physics curriculum has adopted new learning outcomes and ways to…

  7. Bonding core mating surfaces improves transformer

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1978-01-01

    Modifications to assembly procedures for C-core transformers virtually eliminates changes in core end gaps due to temperature cycling during impregnation and potting stages, thus stabilizing magnetization properties of core.

  8. Transforming air quality management

    SciTech Connect

    Janet McCabe

    2005-04-01

    Earlier this year, the Clean Air Act Advisory Committee submitted to EPA 38 recommendations intended to improve air quality management in the United States. This article summarizes the evaluation process leading up to the Committee's recommendations. 3 refs., 2 figs.

  9. Development of Toroidal Core Transformers

    SciTech Connect

    Leon, Francisco

    2014-05-31

    The original objective of this project was to design, build and test a few prototypes of singlephase dry-type distribution transformers of 25 kVA, 2.4 kV primary to 120 V transformers using cores made of a continuous steel strip shaped like a doughnut (toroid). At different points during the development of the project, the scope was enhanced to include the more practical case of a 25 kVA transformer for a 13.8 kV primary system voltage. Later, the scope was further expanded to design and build a 50 kVA unit to transformer voltage from 7.62 kV to 2x120 V. This is a common transformer used by Con Edison of New York and they are willing to test it in the field. The project officially started in September 2009 and ended in May 2014. The progress was reported periodically to DOE in eighteen quarterly reports. A Continuation Application was submitted to DOE in June 2010. In May 2011 we have requested a non-cost extension of the project. In December 2011, the Statement of Project Objectives (SOPO) was updated to reflect the real conditions and situation of the project as of 2011. A second Continuation Application was made and funding was approved in 2013 by DOE and the end date was extended to May 2014.The technical challenges that were overcome in this project include: the development of the technology to pass the impulse tests, derive a model for the thermal performance, produce a sound mechanical design, and estimate the inrush current. However, the greatest challenge that we faced during the development of the project was the complications of procuring the necessary parts and materials to build the transformers. The actual manufacturing process is relatively fast, but getting all parts together is a very lengthy process. The main products of this project are two prototypes of toroidal distribution transformers of 7.62 kV (to be used in a 13.8 kV system) to 2x120 V secondary (standard utilization voltage); one is rated at 25 kVA and the other at 50 kVA. The 25 k

  10. Producing gapped-ferrite transformer cores

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1980-01-01

    Improved manufacturing techniques make reproducible gaps and minimize cracking. Molded, unfired transformer cores are cut with thin saw and then fired. Hardened semicircular core sections are bonded together, placed in aluminum core box, and fluidized-coated. After winding is run over box, core is potted. Economical method significantly reduces number of rejects.

  11. Exploring Function Transformations Using the Common Core

    ERIC Educational Resources Information Center

    Hall, Becky; Giacin, Rich

    2013-01-01

    When examining transformations of the plane in geometry, teachers typically have students experiment with transformations of polygons. Students are usually quick to notice patterns with ordered pairs. The Common Core State Standard, Geometry, Congruence 2 (G-CO.2), requires students to describe transformations as functions that take points in the…

  12. KSI's Cross Insulated Core Transformer Technology

    SciTech Connect

    Uhmeyer, Uwe

    2009-08-04

    Cross Insulated Core Transformer (CCT) technology improves on Insulated Core Transformer (ICT) implementations. ICT systems are widely used in very high voltage, high power, power supply systems. In an ICT transformer ferrite core sections are insulated from their neighboring ferrite cores. Flux leakage is present at each of these insulated gaps. The flux loss is raised to the power of stages in the ICT design causing output voltage efficiency to taper off with increasing stages. KSI's CCT technology utilizes a patented technique to compensate the flux loss at each stage of an ICT system. Design equations to calculate the flux compensation capacitor value are presented. CCT provides corona free operation of the HV stack. KSI's CCT based High Voltage power supply systems offer high efficiency operation, high frequency switching, low stored energy and smaller size over comparable ICT systems.

  13. KSI's Cross Insulated Core Transformer Technology

    NASA Astrophysics Data System (ADS)

    Uhmeyer, Uwe

    2009-08-01

    Cross Insulated Core Transformer (CCT) technology improves on Insulated Core Transformer (ICT) implementations. ICT systems are widely used in very high voltage, high power, power supply systems. In an ICT transformer ferrite core sections are insulated from their neighboring ferrite cores. Flux leakage is present at each of these insulated gaps. The flux loss is raised to the power of stages in the ICT design causing output voltage efficiency to taper off with increasing stages. KSI's CCT technology utilizes a patented technique to compensate the flux loss at each stage of an ICT system. Design equations to calculate the flux compensation capacitor value are presented. CCT provides corona free operation of the HV stack. KSI's CCT based High Voltage power supply systems offer high efficiency operation, high frequency switching, low stored energy and smaller size over comparable ICT systems.

  14. Improved Thermoplastic/Iron-Particle Transformer Cores

    NASA Technical Reports Server (NTRS)

    Wincheski, Russell A.; Bryant, Robert G.; Namkung, Min

    2004-01-01

    A method of fabricating improved transformer cores from composites of thermoplastic matrices and iron-particles has been invented. Relative to commercially available laminated-iron-alloy transformer cores, the cores fabricated by this method weigh less and are less expensive. Relative to prior polymer-matrix/ iron-particle composite-material transformer cores, the cores fabricated by this method can be made mechanically stronger and more magnetically permeable. In addition, whereas some prior cores have exhibited significant eddy-current losses, the cores fabricated by this method exhibit very small eddy-current losses. The cores made by this method can be expected to be attractive for use in diverse applications, including high-signal-to-noise transformers, stepping motors, and high-frequency ignition coils. The present method is a product of an experimental study of the relationships among fabrication conditions, final densities of iron particles, and mechanical and electromagnetic properties of fabricated cores. Among the fabrication conditions investigated were molding pressures (83, 104, and 131 MPa), and molding temperatures (250, 300, and 350 C). Each block of core material was made by uniaxial-compression molding, at the applicable pressure/temperature combination, of a mixture of 2 weight percent of LaRC (or equivalent high-temperature soluble thermoplastic adhesive) with 98 weight percent of approximately spherical iron particles having diameters in the micron range. Each molded block was cut into square cross-section rods that were used as core specimens in mechanical and electromagnetic tests. Some of the core specimens were annealed at 900 C and cooled slowly before testing. For comparison, a low-carbon-steel core was also tested. The results of the tests showed that density, hardness, and rupture strength generally increased with molding pressure and temperature, though the correlation was rather weak. The weakness of the correlation was attributed to

  15. Saturation current spikes eliminated in saturable core transformers

    NASA Technical Reports Server (NTRS)

    Schwarz, F. C.

    1971-01-01

    Unsaturating composite magnetic core transformer, consisting of two separate parallel cores designed so impending core saturation causes signal generation, terminates high current spike in converter primary circuit. Simplified waveform, demonstrates transformer effectiveness in eliminating current spikes.

  16. Acoustic detection of air shower cores

    NASA Technical Reports Server (NTRS)

    Gao, X.; Liu, Y.; Du, S.

    1985-01-01

    At an altitude of 1890m, a pre-test with an Air shower (AS) core selector and a small acoustic array set up in an anechoic pool with a volume of 20x7x7 cu m was performed, beginning in Aug. 1984. In analyzing the waveforms recorded during the effective working time of 186 hrs, three acoustic signals which cannot be explained as from any source other than AS cores were obtained, and an estimation of related parameters was made.

  17. Thermal Behavior of a Medium-Frequency Ferrite-Core Power Transformer

    NASA Astrophysics Data System (ADS)

    Balci, Selami; Sefa, Ibrahim; Altin, Necmi

    2016-05-01

    In this study, design and thermal analysis of a medium-frequency transformer with ferrite N87 core have been carried out using finite-element analysis software. A thermal model of the medium-frequency transformer is generated and analyzed with different cooling methods. In addition, it is proposed to attach additional heat sinks at the top and bottom of the transformer core. Effects of these additional heat sinks on cooling performance and sizing of the transformer are investigated. Furthermore, the cooling capacity of the proposed material is investigated, depending on the air flow velocity for the forced-air cooling method. Thus, more realistic behavior of the ferrite N87 material is obtained for a medium-frequency transformer with 35 kVA rated power and 10 kHz operating frequency. Moreover, electromagnetic and thermal analyses are carried out through linked simulations. The heat distribution in the core including saturation effect is also investigated in detail.

  18. Thermal Behavior of a Medium-Frequency Ferrite-Core Power Transformer

    NASA Astrophysics Data System (ADS)

    Balci, Selami; Sefa, Ibrahim; Altin, Necmi

    2016-08-01

    In this study, design and thermal analysis of a medium-frequency transformer with ferrite N87 core have been carried out using finite-element analysis software. A thermal model of the medium-frequency transformer is generated and analyzed with different cooling methods. In addition, it is proposed to attach additional heat sinks at the top and bottom of the transformer core. Effects of these additional heat sinks on cooling performance and sizing of the transformer are investigated. Furthermore, the cooling capacity of the proposed material is investigated, depending on the air flow velocity for the forced-air cooling method. Thus, more realistic behavior of the ferrite N87 material is obtained for a medium-frequency transformer with 35 kVA rated power and 10 kHz operating frequency. Moreover, electromagnetic and thermal analyses are carried out through linked simulations. The heat distribution in the core including saturation effect is also investigated in detail.

  19. Development of a high permeability cored transintegumental power transformer.

    PubMed

    Helmicki, A J; Melvin, D M; Henderson, H T; Nebrigic, D; Venkat, R; Glos, D L

    1996-01-01

    Circulatory support devices require 10-20 W. Currently, several devices are under development for the transmission of this power via transcutaneous transformers, with the secondary implanted subcutaneously and the primary worn externally. Because these devices are air cored, they have relatively large, bulky external appliances, poor coil to coil coupling, and result in significant stray fields passing through adjacent tissues. This article reports on the engineering design of a novel, high permeability cored transformer implanted in a transenteric configuration using an isolated intestinal pouch. Such an approach offers greater energy transmission efficiency, less heat dissipation, less stray electromagnetic energy, and greatly reduced device size. Two competing designs using this concept have been developed and tested. Each consists of the transformer, together with power interface electronics, forming a direct current (DC)/DC resonant converter. Operating frequencies are 90.2 and 14.7 kHz, respectively, with primary/secondary turns ratios of 10/10 and 11/14, respectively. In addition, data interface electronics allows communication across the transformer of up to four signals at a per channel sample rate of 10 Hz. Both designs are able to continuously transmit 25 W at an output level of 12 Vdc into a 5.8 omega load. Calorimetry tests indicate DC to DC efficiencies greater than 75% and coil to coil efficiencies greater than 96%. Total package size for the implantable portion of each device (including sensor internal interface electronics) is less than 40 ml, with a weight weight of less than 100 g. The results of short-term implantation studies have been favorable. Long-term implantation studies currently are under way. PMID:8944956

  20. Flat-band assembly for toroidal transformer cores

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1973-01-01

    Toroidal transformer cores are often banded together by means of strap. Spot welds secure strap. Proper tension is obtained by use of special fixture in conjunction with winding of wire which is placed temporarily on core; winding is excited by dc current to hold core halves together magnetically during alignment.

  1. Effect of electrical steel grade on transformer core audible noise

    NASA Astrophysics Data System (ADS)

    Valkovic, Z.

    1994-05-01

    The effect of different core material grades (M4, MOH and ZDKH) on noise level was investigated experimentally on single-phase dry-type transformer models. Two types of core design were used (conventional mitred overlapping and step-lap overlapping). The models with MOH and ZDKH material have roughly the same noise levels. The models with M4 grade material have higher noise levels than those with MOH or ZDKH, but the difference depends on core induction and core design.

  2. Wire bonded 3D coils render air core microtransformers competitive

    NASA Astrophysics Data System (ADS)

    Moazenzadeh, A.; Spengler, N.; Lausecker, R.; Rezvani, A.; Mayer, M.; Korvink, J. G.; Wallrabe, U.

    2013-11-01

    We present a novel wafer-level fabrication method for 3D solenoidal microtransformers using an automatic wire bonder for chip-scale, very high frequency regime applications. Using standard microelectromechanical systems fabrication processes for the manufacturing of supporting structures, together with ultra-fast wire bonding for the fabrication of solenoids, enables the flexible and repeatable fabrication, at high throughput, of high performance air core microtransformers. The primary and secondary solenoids are wound one on top of the other in the lateral direction, using a 25 µm thick insulated wire. Besides commonly available gold wire, we also introduce insulated copper wire to our coil winding process. The influence of copper on the transformer properties is explored and compared to gold. A simulation model based on the solenoids’ wire bonding trajectories has been defined using the FastHenry software to accurately predict and optimize the transformer's inductive properties. The transformer chips are encapsulated in polydimethylsiloxane in order to protect the coils from environmental influences and mechanical damage. Meanwhile, the effect of the increase in the internal capacitance of the chips as a result of the encapsulation is analyzed. A fabricated transformer with 20 windings in both the primary and the secondary coils, and a footprint of 1 mm2, yields an inductance of 490 nH, a maximum efficiency of 68%, and a coupling factor of 94%. The repeatability of the coil winding process was investigated by comparing the data of 25 identically processed devices. Finally, the microtransformers are benchmarked to underline the potential of the technology in rendering air core transformers competitive.

  3. Variable frequency transistor inverters use multiple core transformers

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Magnetic-coupled multivibrators containing two or more square-loop cores with multiple windings in a single transformer package, provide indirect frequency control and improved operational characteristics. This multivibrator can be used for power oscillators, nonlinear magnetic circuitry and telemetry circuits.

  4. Design considerations for an air core magnetic actuator

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.

    1992-01-01

    Equations for the force produced by an air core electromagnet on a permanent magnet core as a function of the coil height, coil inner and outer radii, and core displacement are developed. The magnetization vector of the permanent magnet core is assumed to be aligned with the central axis of the electromagnet and the forces which are produced lie along the same axis. Variations in force due to changes in electromagnet parameters and core displacement are investigated and parameter plots which should be useful for coil design are presented.

  5. Structure of air shower disc near the core

    NASA Technical Reports Server (NTRS)

    Inoue, N.; Kawamoto, M.; Misaki, Y.; Maeda, T.; Takeuchi, T.; Toyoda, Y.

    1985-01-01

    The longitudinal structure of the air shower disk is studied by measuring the arrival time distributions of air shower particles for showers with electron size in the range 3.2 x 10 to the 5.5. power to 3.2 x 10 to the 7.5 power in the Akeno air-shower array (930 gcm squared atmospheric depth). The average FWHM as a parameter of thickness of air shower disk increases with core distances at less than 50m. AT the present stage, dependence on electron size, zenith angle and air shower age is not apparent. The average thickness of the air shower disk within a core distance of 50m could be determined by an electromagnetic cascade starting from the lower altitude.

  6. REMOTE FOURIER TRANSFORM INFRARED AIR POLLUTION STUDIES

    EPA Science Inventory

    A commercial Fourier transform infrared interferometer system has been installed in a van and used to make longpath absorption and single-ended emission measurements of gaseous pollutant concentrations at a variety of pollutant sources. The interferometer system is described and ...

  7. Air core poloidal magnetic field system for a toroidal plasma producing device

    DOEpatents

    Marcus, Frederick B.

    1978-01-01

    A poloidal magnetics system for a plasma producing device of toroidal configuration is provided that reduces both the total volt-seconds requirement and the magnitude of the field change at the toroidal field coils. The system utilizes an air core transformer wound between the toroidal field (TF) coils and the major axis outside the TF coils. Electric current in the primary windings of this transformer is distributed and the magnetic flux returned by air core windings wrapped outside the toroidal field coils. A shield winding that is closely coupled to the plasma carries a current equal and opposite to the plasma current. This winding provides the shielding function and in addition serves in a fashion similar to a driven conducting shell to provide the equilibrium vertical field for the plasma. The shield winding is in series with a power supply and a decoupling coil located outside the TF coil at the primary winding locations. The present invention requires much less energy than the usual air core transformer and is capable of substantially shielding the toroidal field coils from poloidal field flux.

  8. Apparatus and method for controlling the temperature of the core of a super-conducting transformer

    DOEpatents

    Golner, Thomas; Pleva, Edward; Mehta, Shirish

    2006-10-10

    An apparatus for controlling the temperature of a core of a transformer is provided that includes a core, a shield surrounding the core, a cast formed between the core and the shield, and tubing positioned on the shield. The cast directs heat from the core to the shield and cooling fluid is directed through the tubing to cool the shield.

  9. Simplified Model of Contactless Air-Core Power Alternator and Transfer Using Ideal Superconductor

    NASA Astrophysics Data System (ADS)

    Jin, Jian Xun; Chen, Xiao Yuan

    The feasibility study of a contactless power transfer (CPT) system using high temperature superconducting (HTS) DC windings has been carried out. The analyses on two HTS CPT application schemes with iron-core and air-core loosely-coupled transformer structures indicate that the introduction of HTS DC windings makes the large-current coupling CPT available for improving the transfer power and efficiency, promising for large-power AC and DC contactless loads, and its transfer efficiency almost coincides with efficiency of the cooperated motor. The design considerations and procedures of the HTS CPT system have also been discussed.

  10. Technical Issues Associated with Air Ingression During Core Degradation

    SciTech Connect

    POWERS,DANA A.

    2000-06-05

    This paper has shown that it is possible to get significant air intrusion into a ruptured reactor vessel even from a reactor cavity with restricted access. This suggests that there is some importance to considering the consequences of air intrusion following vessel penetration by core debris. The consequences will depend on the nature of core degradation in air and other oxidizing gases. If, indeed, fuel becomes exposed to strongly oxidizing gases, significant releases of ruthenium and hexavalent urania can be expected. Hexavalent urania could alter the nature of cesium release and cesium revaporization from the reactor coolant system. Hexavalent urania could destabilize CSI and enhance the formation of gaseous iodine unless there are other materials that will react readily with atomic iodine along the flow path to the reactor containment.

  11. Investigation of the influence of magnetostriction and magnetic forces on transformer core noise and vibration

    NASA Astrophysics Data System (ADS)

    Phophongviwat, Teeraphon

    Transformer noise is of increasing environmental concern so continued efforts are being made by electrical steel and transformer producers to satisfy users by reducing the noise. Magnetostriction and magnetic forces are the main causes of transformer core noise and vibration. Understanding of the relationship from the core material to core structure and core vibration to core noise can help the design of low noise transformer cores. The most appropriate parameter for investigating the relationship between noise and vibration is sound pressure (in the unit of Pascals) in the frequency domain because it is not A-weighted. In this study, the side surfaces of transformer cores were found to emit higher noise than front and top surfaces at low magnetic induction. When the magnetic induction was increased, the effect of magnetic force increased and caused the front surfaces to emit higher noise. For three phase three limb transformer cores, the front surface of the middle limb generated higher noise than the outer limbs due to the effect of T-joint. However this does not translate higher noise level because of the phase difference of the vibration between the limbs. Due to this A-weighted sound power level of three phase, three limb transformer cores were shown to be lower than single phase transformer cores, although at the same cross sectional area and core window size the three phase cores has larger size.. A model, developed to separate the effects of magnetostriction and magnetic forces on transformer core vibration, showed that at low induction, magnetostriction is more significant than magnetic forces. The magnetic forces become more significant than magnetostriction when the induction is increased. Magnetostriction primarily depends on material and stress but magnetic forces principally depend on core building. Louder noise can be generated from a core built with low magnetostriction material than higher magnetostriction if the building tolerances are worse. The

  12. Discrete wavelet transform core for image processing applications

    NASA Astrophysics Data System (ADS)

    Savakis, Andreas E.; Carbone, Richard

    2005-02-01

    This paper presents a flexible hardware architecture for performing the Discrete Wavelet Transform (DWT) on a digital image. The proposed architecture uses a variation of the lifting scheme technique and provides advantages that include small memory requirements, fixed-point arithmetic implementation, and a small number of arithmetic computations. The DWT core may be used for image processing operations, such as denoising and image compression. For example, the JPEG2000 still image compression standard uses the Cohen-Daubechies-Favreau (CDF) 5/3 and CDF 9/7 DWT for lossless and lossy image compression respectively. Simple wavelet image denoising techniques resulted in improved images up to 27 dB PSNR. The DWT core is modeled using MATLAB and VHDL. The VHDL model is synthesized to a Xilinx FPGA to demonstrate hardware functionality. The CDF 5/3 and CDF 9/7 versions of the DWT are both modeled and used as comparisons. The execution time for performing both DWTs is nearly identical at approximately 14 clock cycles per image pixel for one level of DWT decomposition. The hardware area generated for the CDF 5/3 is around 15,000 gates using only 5% of the Xilinx FPGA hardware area, at 2.185 MHz max clock speed and 24 mW power consumption.

  13. Character of energy flow in air shower core

    NASA Technical Reports Server (NTRS)

    Mizushima, K.; Asakimori, K.; Maeda, T.; Kameda, T.; Misaki, Y.

    1985-01-01

    Energy per charged particle near the core of air showers was measured by 9 energy flow detectors, which were the combination of Cerenkov counters and scintillators. Energy per particle of each detector was normalized to energy at 2m from the core. The following results were obtained as to the energy flow: (1) integral frequency distribution of mean energy per particle (averaged over 9 detectors) is composed of two groups separated distinctly; and (2) showers contained in one group show an anisotropy of arrival direction.

  14. Reducing audible noise for distribution transformer with HB1 amorphous core

    NASA Astrophysics Data System (ADS)

    Chang, Yeong-Hwa; Hsu, Chang-Hung; Lin, Hung-Wei; Tseng, Ching-Pei

    2011-04-01

    In this paper, the way to reduce the audible noise of a distribution transformer is presented by incorporating a newly developed transformer core and a rigid-structure tank. The vibrations related tothe core structure and tank frame are considered, so that a distribution transformer with accelerometers mounted on the internal core and external tank, respectively, is addressed. In practice, the core with a new joint structure and the tank with a strong rigid-frame (H-type) are applied to a single-phase amorphous HB1-cored transformer with capacity 167 kVA for performance verification. Finally, a personal computer-based data acquisition platform is setup for signal measurement and processing. Experimental results demonstrate that the HB1 amorphous-cored transformer with the proposed core joint and rigid-structure tank can be performed well in the aspect of audible noise reduction.

  15. Transformations in Air Transportation Systems For the 21st Century

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.

    2004-01-01

    Globally, our transportation systems face increasingly discomforting realities: certain of the legacy air and ground infrastructures of the 20th century will not satisfy our 21st century mobility needs. The consequence of inaction is diminished quality of life and economic opportunity for those nations unable to transform from the 20th to 21st century systems. Clearly, new thinking is required regarding business models that cater to consumers value of time, airspace architectures that enable those new business models, and technology strategies for innovating at the system-of-networks level. This lecture proposes a structured way of thinking about transformation from the legacy systems of the 20th century toward new systems for the 21st century. The comparison and contrast between the legacy systems of the 20th century and the transformed systems of the 21st century provides insights into the structure of transformation of air transportation. Where the legacy systems tend to be analog (versus digital), centralized (versus distributed), and scheduled (versus on-demand) for example, transformed 21st century systems become capable of scalability through technological, business, and policy innovations. Where air mobility in our legacy systems of the 20th century brought economic opportunity and quality of life to large service markets, transformed air mobility of the 21st century becomes more equitable available to ever-thinner and widely distributed populations. Several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems create new foundations for 21st thinking about air transportation. One of the technological developments of importance arises from complexity science and modern network theory. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of robustness

  16. Warm-air advection, air mass transformation and fog causes rapid ice melt

    NASA Astrophysics Data System (ADS)

    Tjernström, Michael; Shupe, Matthew D.; Brooks, Ian M.; Persson, P. Ola G.; Prytherch, John; Salisbury, Dominic J.; Sedlar, Joseph; Achtert, Peggy; Brooks, Barbara J.; Johnston, Paul E.; Sotiropoulou, Georgia; Wolfe, Dan

    2015-07-01

    Direct observations during intense warm-air advection over the East Siberian Sea reveal a period of rapid sea-ice melt. A semistationary, high-pressure system north of the Bering Strait forced northward advection of warm, moist air from the continent. Air-mass transformation over melting sea ice formed a strong, surface-based temperature inversion in which dense fog formed. This induced a positive net longwave radiation at the surface while reducing net solar radiation only marginally; the inversion also resulted in downward turbulent heat flux. The sum of these processes enhanced the surface energy flux by an average of ~15 W m-2 for a week. Satellite images before and after the episode show sea-ice concentrations decreasing from > 90% to ~50% over a large area affected by the air-mass transformation. We argue that this rapid melt was triggered by the increased heat flux from the atmosphere due to the warm-air advection.

  17. Application of Fourier transform spectroscopy to air pollution problems

    NASA Astrophysics Data System (ADS)

    Shaw, J. H.; Calvert, J. G.

    1980-11-01

    The nature of information that can be retrieved from spectra obtained with Fourier transform spectroscopy is discussed. Nonlinear, least squares analysis of spectra is capable of retrieving information that is beyond the reach of conventional methods and has improved precision and accuracy. Fourier transform infrared spectroscopy was used to study quantitatively the kinetics and mechanisms of several chemical reactions that are of interest to atmospheric chemists and are important in the development of air pollution control strategies. The systems studied include the metastable, reactive, gaseous species, peroxynitric acid, hypochlorous acid, and dimethylnitrosamine.

  18. Calculation of core loss and copper loss in amorphous/nanocrystalline core-based high-frequency transformer

    NASA Astrophysics Data System (ADS)

    Liu, Xiaojing; Wang, Youhua; Zhu, Jianguo; Guo, Youguang; Lei, Gang; Liu, Chengcheng

    2016-05-01

    Amorphous and nanocrystalline alloys are now widely used for the cores of high-frequency transformers, and Litz-wire is commonly used as the windings, while it is difficult to calculate the resistance accurately. In order to design a high-frequency transformer, it is important to accurately calculate the core loss and copper loss. To calculate the core loss accurately, the additional core loss by the effect of end stripe should be considered. It is difficult to simulate the whole stripes in the core due to the limit of computation, so a scale down model with 5 stripes of amorphous alloy is simulated by the 2D finite element method (FEM). An analytical model is presented to calculate the copper loss in the Litz-wire, and the results are compared with the calculations by FEM.

  19. An Investigation of Ferrite and Nanocrystalline Core Materials for Medium-Frequency Power Transformers

    NASA Astrophysics Data System (ADS)

    Balci, Selami; Sefa, Ibrahim; Altin, Necmi

    2016-08-01

    In this study, two transformers are designed using the ferrite N87 and the nanocrystalline core materials for the same power level and operating frequency. The operating frequency is defined as 10 kHz, which is suitable for both materials. Modeling and simulation studies have been performed with the same finite element analysis software and the obtained results have been reported. The nanocrystalline and the ferrite N87 core materials have been compared according to both electrical and mechanical parameters. In these comparisons, many features such as core and winding losses, flux distributions, leakage flux, efficiency, and both electrical and mechanical performance have been reported comparatively in the case of rectangular waveform excitation of the transformer. Obtained results show that the weight and the volume of the transformer are reduced and more compact transformer is designed by using the nanocrystalline core material. In addition, besides the core loss, winding losses are also reduced in this design.

  20. An Investigation of Ferrite and Nanocrystalline Core Materials for Medium-Frequency Power Transformers

    NASA Astrophysics Data System (ADS)

    Balci, Selami; Sefa, Ibrahim; Altin, Necmi

    2016-05-01

    In this study, two transformers are designed using the ferrite N87 and the nanocrystalline core materials for the same power level and operating frequency. The operating frequency is defined as 10 kHz, which is suitable␣for both materials. Modeling and simulation studies have been performed with the same finite element analysis software and the obtained results have been reported. The nanocrystalline and the ferrite N87 core materials have been compared according to both electrical and mechanical parameters. In these comparisons, many features such as core and winding losses, flux distributions, leakage flux, efficiency, and both electrical and mechanical performance have been reported comparatively in the case of rectangular waveform excitation of the transformer. Obtained results show that the weight and the volume of the transformer are reduced and more compact transformer is designed by using the nanocrystalline core material. In addition, besides the core loss, winding losses are also reduced in this design.

  1. Design and material selection for inverter transformer cores

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1973-01-01

    Report is announced which studied magnetic properties of candidate materials for use in spacecraft transformers, static inverters, converters, and transformer-rectifier power supplies. Included are material characteristics for available alloy compositions in tabular form, including: trade names, saturated flux density, dc coercive force, loop squareness, material density, and watts per pound at 3 KHz.

  2. BIOAVAILABILITY, ENVIRONMENTAL TRANSFORMATION, AND DETOXIFICATION OF CORE/SHELL NANOMATERIALS

    EPA Science Inventory

    The proposed research is targeted at minimizing environmental and health risks associated with commercial nanotubes and quantum dots by proper management of core chemical toxicants. The work will lead to validated chemical screening assays for bioavailability assessment, data ...

  3. Air-core grid for scattered x-ray rejection

    DOEpatents

    Logan, Clinton M.; Lane, Stephen M.

    1995-01-01

    The invention is directed to a grid used in x-ray imaging applications to block scattered radiation while allowing the desired imaging radiation to pass through, and to process for making the grid. The grid is composed of glass containing lead oxide, and eliminates the spacer material used in prior known grids, and is therefore, an air-core grid. The glass is arranged in a pattern so that a large fraction of the area is open allowing the imaging radiation to pass through. A small pore size is used and the grid has a thickness chosen to provide high scatter rejection. For example, the grid may be produced with a 200 .mu.m pore size, 80% open area, and 4 mm thickness.

  4. Air-core grid for scattered x-ray rejection

    DOEpatents

    Logan, C.M.; Lane, S.M.

    1995-10-03

    The invention is directed to a grid used in x-ray imaging applications to block scattered radiation while allowing the desired imaging radiation to pass through, and to process for making the grid. The grid is composed of glass containing lead oxide, and eliminates the spacer material used in prior known grids, and is therefore, an air-core grid. The glass is arranged in a pattern so that a large fraction of the area is open allowing the imaging radiation to pass through. A small pore size is used and the grid has a thickness chosen to provide high scatter rejection. For example, the grid may be produced with a 200 {micro}m pore size, 80% open area, and 4 mm thickness. 2 figs.

  5. EMPACT: Electrons Muons Partons with Air Core Toroids

    SciTech Connect

    Marx, M.D. )

    1990-05-25

    The EMPACT experiment utilizes a broad approach to maximize its discovery potential for new phenomena accessible at the SSC. The high resolution detector has a balances emphasis on, and large acceptance for, electrons, muons, jets, and noninteracting particles, and is capable of utilizing the ultimate luminosity of the SSC. The detector emphasizes excellent calorimetry augmented by TRD tracking, and employs an innovative system of superconducting air core toroids for muon measurements. Significant engineering effort has established the feasibility of a baseline detector concept and has addressed the related issues of support facilities, assembly, and detector integration. The design has been tested against the challenges of predicted phenomena, with the expectation that this will optimize the capacity for observing the unexpected. EMPACT's international collaboration has unprecedented support from major aerospace industries who are providing tools and expertise for project design and integration, which will assure that a detector optimized for performance and cost will be available for the first collisions at the new laboratory.

  6. Core testing of zinc/air refuelable battery modules

    SciTech Connect

    Cooper, J. F., LLNL

    1998-08-20

    We are developing a refuelable zinc/air battery (6-cells) for evaluation under the five USABC `core` test protocols. In the first half of the two year project ($1OOK, FY1997), an advanced refuelable design was developed, fabricated and tested at power levels up to 415 W. Performance matched or exceeded that of earlier multicell systems. A computer program was developed for automated data acquisition and drive cycle simulation. Small mockup cells (80 cm 2) were constructed for rapid testing of components. In the follow-on effort (FY1998, $1OOK) we will make minor advances in system design and fabrication efficiency, and seek to improve cathode performance and life, before delivery of two final units for test at DOE laboratory.

  7. Improvement of transformer core magnetic properties using the step-lap design

    NASA Astrophysics Data System (ADS)

    Valkovic, Z.; Rezic, A.

    1992-07-01

    Magnetic properties of the step-lap joints have been investigated experimentally on two three-phase three-leg transformer cores. Using the step-lap joint design, a reduction of the total core loss of 2 to 4.4% and of the exciting power of 31 to 37% has been obtained.

  8. Principled, Transformational Leadership: Analyzing the Discourse of Leadership in the Development of Librarianship's Core Competences

    ERIC Educational Resources Information Center

    Hicks, Deborah; Given, Lisa M.

    2013-01-01

    Using discourse analysis, this article explores three questions: (a) Why was "principled, transformational leadership" the leadership style added to Core Competences? (b) What was the discourse of leadership in the profession surrounding the development of the Core Competences? (c) How might this competence affect LIS education? And what measures,…

  9. Core Principles for Transforming Remedial Education: A Joint Statement

    ERIC Educational Resources Information Center

    Jobs for the Future, 2012

    2012-01-01

    As a result of new research and promising practice, we have more clarity than ever about how we can fundamentally transform our developmental education system to improve success for all students. To propel the movement forward, this statement offers a set of clear and actionable principles that, although not the final word on remedial education…

  10. Electrical Core Transformer for Grid Improvement Incorporating Wire Magnetic Components

    SciTech Connect

    Harrie R. Buswell, PhD; Dennis Jacobs, PhD; Steve Meng

    2012-03-26

    The research reported herein adds to the understanding of oil-immersed distribution transformers by exploring and demonstrating potential improvements in efficiency and cost utilizing the unique Buswell approach wherein the unit is redesigned, replacing magnetic sheet with wire allowing for improvements in configuration and increased simplicity in the build process. Exploration of new designs is a critical component in our drive to assure reduction of energy waste, adequate delivery to the citizenry, and the robustness of U.S. manufacturing. By moving that conversation forward, this exploration adds greatly to our base of knowledge and clearly outlines an important avenue for further exploration. This final report shows several advantages of this new transformer type (outlined in a report signed by all of our collaborating partners and included in this document). Although materials development is required to achieve commercial potential, the clear benefits of the technology if that development were a given is established. Exploration of new transformer types and further work on the Buswell design approach is in the best interest of the public, industry, and the United States. Public benefits accrue from design alternatives that reduce the overall use of energy, but it must be acknowledged that new DOE energy efficiency standards have provided some assurance in that regard. Nonetheless the burden of achieving these new standards has been largely shifted to the manufacturers of oil-immersed distribution transformers with cost increasing up to 20% of some units versus 2006 when this investigation was started. Further, rising costs have forced the industry to look closely are far more expensive technologies which may threaten U.S. competitiveness in the distribution transformer market. This concern is coupled with the realization that many units in the nation's grid are beyond their optimal life which suggests that the nation may be headed for an infrastructure crisis

  11. Development and application of amorphous core-distribution transformers in Quebec

    SciTech Connect

    Schulz, R.; Alexandrov, N.; Simoneau, R.; Roberge, R.; Tetreault, J.

    1995-08-01

    This paper describes research and development activities at Hydro-Quebec over the last ten years for improving the efficiency of distribution transformers in Quebec. A shell-type (wound-core) design making optimum use of the properties of amorphous metals (Metglas TCA formerly known as Metglas 2605s-2, Allied Signal Inc., Morristown, NJ) was adopted. Dry and oil-cooled, amorphous-core transformer prototypes were built. The joint research and development project was initiated with Transformateurs Ferranti-Packard Ltee, a company of Rolls-Royce Industries Canada Inc., to build and test a few units of high performance transformers on the Hydro-Quebec power system.

  12. Transformational Teaching: Theoretical Underpinnings, Basic Principles, and Core Methods

    PubMed Central

    Slavich, George M.; Zimbardo, Philip G.

    2012-01-01

    Approaches to classroom instruction have evolved considerably over the past 50 years. This progress has been spurred by the development of several learning principles and methods of instruction, including active learning, student-centered learning, collaborative learning, experiential learning, and problem-based learning. In the present paper, we suggest that these seemingly different strategies share important underlying characteristics and can be viewed as complimentary components of a broader approach to classroom instruction called transformational teaching. Transformational teaching involves creating dynamic relationships between teachers, students, and a shared body of knowledge to promote student learning and personal growth. From this perspective, instructors are intellectual coaches who create teams of students who collaborate with each other and with their teacher to master bodies of information. Teachers assume the traditional role of facilitating students’ acquisition of key course concepts, but do so while enhancing students’ personal development and attitudes toward learning. They accomplish these goals by establishing a shared vision for a course, providing modeling and mastery experiences, challenging and encouraging students, personalizing attention and feedback, creating experiential lessons that transcend the boundaries of the classroom, and promoting ample opportunities for preflection and reflection. We propose that these methods are synergistically related and, when used together, maximize students’ potential for intellectual and personal growth. PMID:23162369

  13. Effects of magnetomechanical vibrations and bending stresses on three-phase three-leg transformers with amorphous cores

    NASA Astrophysics Data System (ADS)

    Hsu, Chang-Hung; Chang, Yeong-Hwa; Lee, Chun-Yao; Yao, Chia-Shiang; He, Yan-Lou; Chu, Huei-Lung; Chang, Chia-Wen; Chan, Wei-Shou

    2012-04-01

    This paper explores the influence of bending stresses on the magnetic characteristics of three-phase transformers with amorphous cores. Different types of core structures, including C-cores and toroidal cores, and their magnetic properties are compared using VSM and XRD. The losses in the magnetic core of the three-phase transformer are analyzed using the finite element analysis for both design and measurement. In addition, experimental results indicated that amorphous-core transformers with rectangular corners had higher audible noise and vibration intensities. This is because the condensed distribution of magnetic flux lines in the corners of the core may create high magnetic inductions associated with high magnetostriction. Finally, experiments with three-phase amorphous-core transformers were performed to study the effects of magnetism and magnetostriction on their performance in terms of core loss, vibration, and audible noise.

  14. Energy loss due to eddy current in linear transformer driver cores

    NASA Astrophysics Data System (ADS)

    Kim, A. A.; Mazarakis, M. G.; Manylov, V. I.; Vizir, V. A.; Stygar, W. A.

    2010-07-01

    In linear transformer drivers [Phys. Rev. ST Accel. Beams 12, 050402 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050402; Phys. Rev. ST Accel. Beams 12, 050401 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050401] as well as any other linear induction accelerator cavities, ferromagnetic cores are used to prevent the current from flowing along the induction cavity walls which are in parallel with the load. But if the core is made of conductive material, the applied voltage pulse generates the eddy current in the core itself which heats the core and therefore also reduces the overall linear transformer driver (LTD) efficiency. The energy loss due to generation of the eddy current in the cores depends on the specific resistivity of the core material, the design of the core, as well as on the distribution of the eddy current in the core tape during the remagnetizing process. In this paper we investigate how the eddy current is distributed in a core tape with an arbitrary shape hysteresis loop. Our model is based on the textbook knowledge related to the eddy current generation in ferromagnetics with rectangular hysteresis loop, and in usual conductors. For the reader’s convenience, we reproduce some most important details of this knowledge in our paper. The model predicts that the same core would behave differently depending on how fast the applied voltage pulse is: in the high frequency limit, the equivalent resistance of the core reduces during the pulse whereas in the low frequency limit it is constant. An important inference is that the energy loss due to the eddy current generation can be reduced by increasing the cross section of the core over the minimum value which is required to avoid its saturation. The conclusions of the model are confirmed with experimental observations presented at the end of the paper.

  15. Toroidal superconducting transformer with cold magnetic core - results of analysis and measurements

    NASA Astrophysics Data System (ADS)

    Grzesik, B.; Stepien, M.

    2014-05-01

    The paper is focused on a toroidal superconducting transformer with cold magnetic core. The transformer was developed aiming at the solution where magnetic core could operate immersed in LN2, not having much higher power losses than a core operating in room temperature. The second aim is concerned to the perpendicular component of the magnetic flux. It was assumed that it should be minimized. The third aim is required maximal coupling coefficient between windings. Magnetic material METGLAS 2605 SA1 (Metglas Ltd) was selected as the best taking electrical and mechanical properties into account. Numerical analysis of the transformer was carried using ANSYS software. It was assumed that magnetic core could be put inside windings and/or outside of it. The analysis and measurements yield that the best solution is the transformer with magnetic core put inside the windings. Such a construction reduces significantly perpendicular component of the magnetic field in HTS wire. Because outer winding is put on the inner one it gives maximal possible coupling coefficient. The primary and the secondary have the same number of turns. It means bifilar way of winding. The described transformer has the following constructional data: i) diameter of the main circle: 144 mm, ii) maximal diameter: 208 mm, iii) diameter of the small cross-section of the transformer (without external magnetic core): 50 mm and it results with the following parameters: output power 1.59 kVA, power density 700 VA/kg, efficiency: 99.5, coupling coefficient 0.99 at 100 ARMS of input current and maximum flux density 1.2 T.

  16. Wireline-rotary air coring of the Bandelier Tuff, Los Alamos, New Mexico

    USGS Publications Warehouse

    Teasdale, W.E.; Pemberton, R.R.

    1984-01-01

    This paper describes experiments using wireline-rotary air-coring techniques conducted in the Bandelier Tuff using a modified standard wireline core-barrel system. The modified equipment was used to collect uncontaminated cores of unconsolidated ash and indurated tuff at Los Alamos, New Mexico. Core recovery obtained from the 210-foot deep test hole was about 92 percent. A standard HQ-size, triple-tube wireline core barrel (designed for the passage of liquid drilling fluids) was modified for air coring as follows: (1) Air passages were milled in the latch body part of the head assembly; (2) the inside dimension of the outer core barrel tube was machined and honed to provide greater clearance between the inner and outer barrels; (3) oversized reaming devices were added to the outer core barrel and the coring bit to allow more clearance for air and cuttings return; (4) the eight discharge ports in the coring bit were enlarged. To control airborne-dust pollution, a dust-and-cuttings discharge subassembly, designed and built by project personnel, was used. (USGS)

  17. Core Principles for Transforming Remediation within a Comprehensive Student Success Strategy: A Joint Statement

    ERIC Educational Resources Information Center

    Education Commission of the States, 2015

    2015-01-01

    Colleges and postsecondary systems across the nation have demonstrated remarkable progress since "Core Principles for Transforming Remediation" was published in 2012. States and institutions are phasing out stand alone or multi-course remediation sequences, resulting in tens of thousands of students more quickly enrolling in and…

  18. Plasma Position Measurements in a Tokamak with an Iron Core Transformer

    NASA Astrophysics Data System (ADS)

    Kwon, Gi-Chung; Choe, W.; Kim, Jayhyun; Yi, Hyo-Suk; Jeon, Sang-Jean; Huh, Songwhe; Chang, Hong-Young; Choi, Duk-In

    2000-07-01

    Two simple methods of estimating the plasma position in a large-aspect-ratio, low-βp tokamak with an iron core transformer are demonstrated: a magnetic diagnostic method and an optical method. The magnetic diagnostic method utilizes an array of magnetic pickup coils to measure the poloidal magnetic field produced by the plasma current. To include the effects of toroidicity and an iron core transformer, the correction factor was calculated with the magnetic material (or iron core) inside the calculation domain and incorporated in the analysis. The evolution of horizontal and vertical displacement of the plasma center obtained in this way is used to control the KAIST-Tokamak plasmas. To compare the plasma position estimated using the magnetic pickup coils, a simple optical method is also demonstrated on KAIST-TOKAMAK using a composite video signal from a charge-coupled device (CCD) camera. The two results are in good agreement.

  19. Development and application of amorphous core-distribution transformers in Québec

    NASA Astrophysics Data System (ADS)

    Schulz, R.; Alexandrov, N.; Tétreault, J.; Simoneau, R.; Roberge, R.

    1995-08-01

    This paper describes research and development activities at Hydro-Québec over the last ten years for improving the efficiency of distribution transformers in Québec. A shell-type (wound-core) design making optimum use of the properties of amorphous metals (Metglas TCA formerly known as Metglas 2605s-2, Allied Signal Inc., Morristown, NJ) was adopted. Dry and oil-cooled, amorphous-core transformer prototypes were built. The joint research and development project was initiated with Transformateurs Ferranti-Packard Ltée, a company of Rolls-Royce Industries Canada Inc., to build and test a few units of high performance transformers on the Hydro-Québec power system.

  20. Post-coring entrapment of modern air in polar ice: Evidence from CFC-12 measurements in Antarctic firn air and shallow ice cores

    NASA Astrophysics Data System (ADS)

    Aydin, K. M.; Montzka, S. A.; Battle, M. O.; Williams, M. B.; de Bruyn, W. J.; Butler, J. H.; Verhulst, K. R.; Tatum, C.; Gun, B. K.; Plotkin, D. A.; Hall, B. D.; Saltzman, E. S.

    2009-12-01

    This study is a comparison of CFC-12 (CCl2F2) measurements in firn air and ice core samples from three Antarctic sites: South Pole, West Antarctic Ice Sheet Divide (79.46°S, 112.13°W), and Siple Dome (81.65°S, 148.81°W). CFC-12 is a synthetic chlorofluorocarbon manufactured during the mid-late 20th century for use as a refrigerant and an aerosol spray propellant. Its atmospheric history is well established with agreement among instrumental time series measurements and industry-reported production data [Walker et al., 2000], the distribution of dissolved CFC-12 in the oceans [e.g. Weiss et al., 1985], and firn air measurements [Butler et al., 1999]. The atmospheric history indicates that there was no measureable CFC-12 in the atmosphere prior to the 1940’s. The firn air CFC-12 profiles are consistent with the known atmospheric history of this gas. In contrast, the air in ice core samples collected near the close-off depth exhibit anomalously high CFC-12 levels. We propose that this is due to entrapment of modern air in open pores that close after drilling, resulting in elevated CFC-12 mixing ratios. These results demonstrate how the composition of air trapped in shallow ice cores can be altered during the post-drilling period through purely physical processes. Comparison of firn air and ice core bubble composition is one of the commonly used tools for studying the bubble close-off process. The post-drilling entrapment process detected in this study represents a potential complication for such investigations.

  1. A NEW METHOD FOR FINDING CORE LOCATIONS OF EXTENSIVE AIR SHOWERS

    SciTech Connect

    Hedayati Kh, H.; Anvari, A.; Bahmanabadi, M.; Samimi, J.; Khakian Ghomi, M.

    2011-02-01

    Analysis of an extensive air shower (EAS) detected by surface arrays highly depends on the determination of core locations. Here we present a new method to find the core location of an EAS that, unlike the common methods, does not depend on the lateral distribution function and uses arrival times of secondary particles. This method improves the accuracy of finding the core location of a low-energy EAS in the internal parts of an array, in comparison with common methods.

  2. The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site

    SciTech Connect

    Ray, J.M.; Newsom, J.C.

    1994-12-01

    The Prototype Air-Coring Test was conducted at the Nevada Test Site (NTS) G-Tunnel facility to evaluate standard coring techniques, modified slightly for air circulation, for use in testing at a prospective nuclear waste repository at Yucca Mountain, Nevada. Air-coring technology allows sampling of subsurface lithology with minimal perturbation to ambient characteristic such as that required for exploratory holes near aquifers, environmental applications, and site characterization work. Two horizontal holes were cored, one 50 ft long and the other 150 ft long, in densely welded fractured tuff to simulate the difficult drilling conditions anticipated at Yucca Mountain. Drilling data from seven holes on three other prototype tests in nonwelded tuff were also collected for comparison. The test was used to establish preliminary standards of performance for drilling and dust collection equipment and to assess procedural efficiencies. The Longyear-38 drill achieved 97% recovery for HQ-size core (-2.5 in.), and the Atlas Copco dust collector (DCT-90) captured 1500 lb of fugitive dust in a mine environment with only minor modifications. Average hole production rates were 6-8 ft per 6-h shift in welded tuff and almost 20 ft per shift on deeper holes in nonwelded tuff. Lexan liners were successfully used to encapsulate core samples during the coring process and protect core properties effectively. The Prototype Air-Coring Test demonstrated that horizontal air coring in fractured welded tuff (to at least 150 ft) can be safely accomplished by proper selection, integration, and minor modification of standard drilling equipment, using appropriate procedures and engineering controls. The test also indicated that rig logistics, equipment, and methods need improvement before attempting a large-scale dry drilling program at Yucca Mountain.

  3. TEM Study of the Growth Mechanism, Phase Transformation, and Core/shell Structure of Semiconductor Nanowires

    NASA Astrophysics Data System (ADS)

    Wong, Tai Lun

    In this thesis, the fabrication and characterization of one-dimensional nanostructures have been studied systematically to understand the growth mechanism and structure transformation of one-dimensional nanostructures. The growth behavior of the ultrathin ZnSe nanowires with diameter less than 60 nm was found to be different from classical vapor-liquid-solid (VLS) process. The growth rate increases when the diameter of nanowires decreases, in contrast to the classical VLS process in which the growth rate increases with the diameter. The nucleation, initial growth, growth rates, defects, interface structures and growth direction of the nanowires were investigated by high resolution transmission electron microscopy (HRTEM). We found the structure and growth direction of ultra-thin nanowires are highly sensitive to growth temperatures and diameters of nanowires. At a low growth temperature (380°C), the growth direction for most nanowires is along <111>. Planar defects were found throughout the nanowires. At a high growth temperature (530°C), uniform nanowires with diameters around 10nm were grown along <110> and <112> directions, and the nanowires with diameters larger than 20nm were mainly grown along <111> direction. The possible growth mechanism of ultrathin nanowires was proposed by combining the solid catalytic growth with the interface diffusion theory, in order to explain how the growth temperature and the size of the catalysts influent the morphology, growth direction and growth rate of ultrathin nanowires. Structural and phase transformation of a nickel coated Si nanowire to NiSi2/SiC core-shell nanowire heterostructures has been investigated by the in-situ Transmission Electron Microscope (TEM). The phase transformation is a single-site nucleation process and therefore a single crystalline NiSi2 core resulted in the core-shell nanowire heterostructures. The transformation of the Si nanowire to NiSi2/SiC core-shell nanowire heterostructures was extremely

  4. A Statistical Method for Reconstructing the Core Location of an Extensive Air Shower

    NASA Astrophysics Data System (ADS)

    Hedayati Kh., H.; Moradi, A.; Emami, M.

    2015-09-01

    Conventional methods of reconstructing extensive air showers (EASs) depend on a lateral density function which itself depends on shower size, age parameter, and core location. In the fitting procedure of a lateral density function to surface array information, the only parameter whose initial value is essential is core location. In this paper, we describe a refined version of a statistical method which can be used to find the initial trial core location of EASs with better precision than the conventional methods. In this method, we use arrival time information of secondary particles for finding not only arrival direction, but also core location.

  5. Noise variation by compressive stress on the model core of power transformers

    NASA Astrophysics Data System (ADS)

    Mizokami, Masato; Kurosaki, Yousuke

    2015-05-01

    The reduction of audible noise generated by cores for power transformers has been required due to environmental concern. It is known that compressive stress in the rolling direction of electrical steel affects magnetostriction and it can result in an increase in noise level. In this research, the effect of compressive stress to noise was investigated on a 3-phase 3-limb model core. Compressive stress was applied in the rolling direction of the limbs from the outside of the core. It increased the sound pressure levels and the slope of the rise was about 2 dBA/MPa. Magnetostriction on single sheet samples was also measured under compressive stress and the harmonic components of the magnetostriction were compared with those of noise. It revealed that the variation in magnetostriction with compressive stress did not entirely correspond to that in noise. In one of the experiments, localized bending happened on one limb during compressing the core. While deformation of the core had not been intended, the noise was measured. The deformation increased the noise by more than 10 dBA and it occurred on most of the harmonic components.

  6. APPLICATION OF FOURIER TRANSFORM SPECTROSCOPY TO AIR POLLUTION PROBLEMS

    EPA Science Inventory

    The nature of information that can be retrieved from spectra obtained with Fourier transform spectroscopy is discussed. Nonlinear, least-squares analysis of spectra is capable of retrieving information that is beyond the reach of conventional methods and has improved precision an...

  7. Reconfigurable optothermal microparticle trap in air-filled hollow-core photonic crystal fiber.

    PubMed

    Schmidt, O A; Garbos, M K; Euser, T G; Russell, P St J

    2012-07-13

    We report a novel optothermal trapping mechanism that occurs in air-filled hollow-core photonic crystal fiber. In the confined environment of the core, the motion of a laser-guided particle is strongly influenced by the thermal-gradient-driven flow of air along the core surface. Known as "thermal creep flow," this can be induced either statically by local heating, or dynamically by the absorption (at a black mark placed on the fiber surface) of light scattered by the moving particle. The optothermal force on the particle, which can be accurately measured in hollow-core fiber by balancing it against the radiation forces, turns out to exceed the conventional thermophoretic force by 2 orders of magnitude. The system makes it possible to measure pN-scale forces accurately and to explore thermally driven flow in micron-scale structures. PMID:23030165

  8. Reconfigurable Optothermal Microparticle Trap in Air-Filled Hollow-Core Photonic Crystal Fiber

    NASA Astrophysics Data System (ADS)

    Schmidt, O. A.; Garbos, M. K.; Euser, T. G.; Russell, P. St. J.

    2012-07-01

    We report a novel optothermal trapping mechanism that occurs in air-filled hollow-core photonic crystal fiber. In the confined environment of the core, the motion of a laser-guided particle is strongly influenced by the thermal-gradient-driven flow of air along the core surface. Known as “thermal creep flow,” this can be induced either statically by local heating, or dynamically by the absorption (at a black mark placed on the fiber surface) of light scattered by the moving particle. The optothermal force on the particle, which can be accurately measured in hollow-core fiber by balancing it against the radiation forces, turns out to exceed the conventional thermophoretic force by 2 orders of magnitude. The system makes it possible to measure pN-scale forces accurately and to explore thermally driven flow in micron-scale structures.

  9. Transforming the NAS: The Next Generation Air Traffic Control System

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    2004-01-01

    The next-generation air traffic control system must be designed to safely and efficiently accommodate the large growth of traffic expected in the near future. It should be sufficiently scalable to contend with the factor of 2 or more increase in demand expected by the year 2020. Analysis has shown that the current method of controlling air traffic cannot be scaled up to provide such levels of capacity. Therefore, to achieve a large increase in capacity while also giving pilots increased freedom to optimize their flight trajectories requires a fundamental change in the way air traffic is controlled. The key to achieving a factor of 2 or more increase in airspace capacity is to automate separation monitoring and control and to use an air-ground data link to send trajectories and clearances directly between ground-based and airborne systems. In addition to increasing capacity and offering greater flexibility in the selection of trajectories, this approach also has the potential to increase safety by reducing controller and pilot errors that occur in routine monitoring and voice communication tasks.

  10. Determination of radiocarbon in stratospheric CO2, obtained through AirCore sampling.

    NASA Astrophysics Data System (ADS)

    Paul, Dipayan; Chen, Huilin; Been, Henk A.; Kivi, Rigel; Meijer, Harro A. J.

    2016-04-01

    The concentration of Greenhouse Gases (GHG), with carbon dioxide as the most prominent example, has been and still is increasing, predominantly due to emissions from fossil fuel combustion. CO2 is also the most important component of the global carbon cycle. Among other tracers, radiocarbon (Carbon-14) is a unique and an important atmospheric tracer used in the understanding of the global carbon cycle. Radiocarbon is a naturally occurring isotope (radioactive, t 1/2 = 5730 ± 40 years) of carbon produced through the interaction of thermalized neutrons and nitrogen in the upper atmosphere. Generally, for performing atmospheric radiocarbon measurements in the higher atmosphere, large samples (few liters of air) were collected using aircrafts and balloons. However, collecting stratospheric samples on a regular basis for radiocarbon analysis is extremely expensive. Here we describe the determination of radiocarbon concentrations in stratospheric CO2, collected using AirCore sampling. AirCore is an innovative sampling technique for obtaining vertical atmospheric profiles and, in Europe, is done on a regular basis at Sodankylä, Finland for CO2, CH4 and CO. The stratospheric parts of two such AirCore profiles were used in this study as a proof-of-principle. CO2 from the stratospheric air samples were extracted and converted to elemental carbon, which were then measured at the Accelerator Mass Spectrometric (AMS) facility of the Centre for Isotope Research (CIO) at the University of Groningen. The stratospheric part of the AirCore profile was divided into six sections, each contained approximately 10 μg C. A detailed description of the extraction, graphitization, AMS analysis and the derivation of the stratospheric radiocarbon profile will be the main focus. Through our results, we will show that AirCore is a viable sampling method for performing high-precision radiocarbon measurements of stratospheric CO2 with reasonably good spatial resolution on a regular basis

  11. Excitation and separation of vortex modes in twisted air-core fiber.

    PubMed

    Ye, Jingfu; Li, Yan; Han, Yanhua; Deng, Duo; Guo, Zhongyi; Gao, Jianmin; Sun, Qiaoqun; Liu, Yi; Qu, Shiliang

    2016-04-18

    An air-core fiber imposed by torsion is investigated in this paper. We refer to this kind of fiber as twisted air-core fiber (TAF). It has been demonstrated that the eigenstates of the TAF consist of guided optical vortex waves with different propagation constants of a different effective index. With the increase of the twist rate, TAF could separate the OAM modes which are near degenerate or degenerate in the air-core fiber. The separation of OAM modes in TAF is conductive to ultralong distance propagation with low crosstalk. TAF could be considered as an ideal candidate fiber for OAM based optical communication. Moreover, we investigated the twisted air-core photonic crystal fiber (TAPCF) which can improve the relative energy distribution of the OAM modes. Compared with TAF, more energy is located in the ring shaped core, which is conductive to ultralong distance propagation. TAF and TAPCF are of potential interest for increasing channel capacity in optical telecommunications, and the result is also of interest to the photonic crystal community. PMID:27137269

  12. Core/shell structural transformation and brittle-to-ductile transition in nanowires

    NASA Astrophysics Data System (ADS)

    Yuan, Zaoshi; Nomura, Ken-ichi; Nakano, Aiichiro

    2012-04-01

    Nanowires (NWs) exhibit thermo-mechanical properties that are distinct from their bulk properties, and their understanding is critical for the reliability, manufacturability, and optimization of a wide range of devices consisting of NWs. Here, molecular-dynamics simulation reveals a rich size-temperature "phase diagram" for the mechanical response of a zinc-oxide NW under tension. For smaller diameters and higher temperatures, transitions are found from brittle cleavage to structural transformation-mediated brittle cleavage to ductile failure. Atomistic mechanisms of the unique nano-thermo-mechanical behavior are elucidated as a consequence of surface-structural relaxation, which in particular predicts spontaneous formation of a core/shell structure under tension. The nano-thermo-mechanical phase diagram resolves controversies between previous experiments and theory, and the predicted "intrinsic" core/shell structure may find device applications.

  13. Development of high frequency spice models for ferrite core inductors and transformers

    SciTech Connect

    Muyshondt, G.P.; Portnoy, W.M. . Dept. of Electrical Engineering)

    1989-01-01

    In this work high frequency SPICE models were developed to simulate the hysteresis and saturation effects of toroidal shaped ferrite core inductors and transformers. The models include the nonlinear, multi-valued B-H characteristic of the core material, leakage flux, stray capacitances, and core losses. The saturation effects were modeled using two diode clamping arrangements in conjunction with nonlinear dependent sources. Two possible controlling schemes were developed for the saturation switch. One of the arrangements used the current flowing through a series RC branch to control the switch, while the other used a NAND gate. The NAND gate implementation of the switch proved to be simpler and the parameters associated with it were easier to determine from the measurements and the B-H characteristics of the material. Lumped parameters were used to simulate the parasitic effects. Techniques for measuring these parasitic are described. The models were verified using manganese-zinc ferrite-type toroidal cores and they have general applicability to all circuit analysis codes equivalent function blocks such as multipliers, adders, and logic components. 7 refs., 22 figs.

  14. Cost-Optimal Design of a 3-Phase Core Type Transformer by Gradient Search Technique

    NASA Astrophysics Data System (ADS)

    Basak, R.; Das, A.; Sensarma, A. K.; Sanyal, A. N.

    2014-04-01

    3-phase core type transformers are extensively used as power and distribution transformers in power system and their cost is a sizable proportion of the total system cost. Therefore they should be designed cost-optimally. The design methodology for reaching cost-optimality has been discussed in details by authors like Ramamoorty. It has also been discussed in brief in some of the text-books of electrical design. The paper gives a method for optimizing design, in presence of constraints specified by the customer and the regulatory authorities, through gradient search technique. The starting point has been chosen within the allowable parameter space the steepest decent path has been followed for convergence. The step length has been judiciously chosen and the program has been maneuvered to avoid local minimal points. The method appears to be best as its convergence is quickest amongst different optimizing techniques.

  15. Electromagnetic flat-faced robot gripper for handling multiple industrial transformer core lamination plates

    SciTech Connect

    Postma, B.; Vinay, T.; Kangsanant, T.; Harvey, A.

    1998-05-01

    In the industrial transformer core assembly process, significant productivity gains can be achieved by utilizing a robotic gripper that is able to handle, and accurately position, multiple transformer laminations during each pick-and-place cycle. This paper reports on the development of a novel electromagnetic lifter for such applications. The lifter has the unique capability to selectively pick a given number of laminations at a time (the usual requirement is three) from a stack. By considering an analytical model of the magnetic circuit of the electromagnet-lamination stack combination, closed form solutions are obtained for the flux flow pattern and the lifting force on each lamination in the stack which closely agrees with the numerical results obtained using two-dimensional finite element analysis software. Results of experiments conducted on a prototype electromagnet are also presented that validate the analytical model findings.

  16. Mid-stratospheric measurements of CO2, CH4, and CO using AirCore

    NASA Astrophysics Data System (ADS)

    Chen, H.; Karion, A.; Newberger, T.; Sweeney, C.; Andrews, A. E.; Tans, P. P.

    2011-12-01

    AirCore, a long tube descending from a high altitude with one end open and the other closed, has been demonstrated to be a reliable, cost-effective sampling system for CO2 and CH4 measurements. Previous studies show that vertical profiles from the ground level up to ~ 20 km (~ 40 mbar) can be achieved during a balloon flight. The ceiling of the profile is restricted mainly by the diffusion of air in the AirCore and the resolution of the analyzer used for the analysis. Here air with an extremely high CO mixing ratio (~ 10 ppm) has been employed as the initial fill air in the AirCore. This high CO fill gas is used as a label to track the mixing between sampled air and fill air at the top of the profile thus providing the ability to retrieve full profiles for CO2 and CH4 up to the balloon's ceiling height of ~ 30 km (~ 11 mbar). Stratospheric measurements of CO lack agreement among previous studies, (i.e. cryogenic sampling, in-situ measurements, and remote sensing) due to difficulties that are inherent to the various techniques and possibly due to latitudinal and seasonal variations that could not be represented by the available sparse observations. Efforts to collect an accurate profile of stratospheric CO using the AirCore, are complicated by the reaction of CO and O3 in the coil, which is particular important for stratospheric air with high O3. To remove the influence of O3 on the CO measurements from AirCore, we have investigated three O3 scrubbers: 1) Manganese dioxide (MnO2); 2) Sodium Sulfite (Na2SO3); 3) Sodium thiosulfate (Na2S2O3). Laboratory tests reveal that Sodium thiosulfate is the best choice as it has sufficient capacity to absorb O3 and does not impact measurements of CO2 and CH4. We will show experimental results from both aircraft and balloon flights. Regular ongoing stratospheric profiles of CO2, CH4, and CO are necessary to improve and validate total column measurements by remote sensing techniques, such as FTS and satellite. Such measurements

  17. Optimum design of transformer cores by analyzing flux and iron loss with the aid of a novel software

    SciTech Connect

    Yu, C.H. ); Basak, A. )

    1993-03-01

    A software package based on the finite element technique has been developed to compute two dimensional magnetic field and loss distribution in transformer cores with the aid of a 386 microprocessor based personal computer. The finite element method offers a stable numerical solution with a high degree of precision and the software package takes into account both the non-linear B-H characteristic and the anisotropy of the core material. Optimum design of transformer cores is reasonably fast and cheap with this software in comparison with FEM packages run on mini or main frame computers. This paper describes several important features in developing the software package and shows computed results for various three-phase three-limb transformer cores.

  18. Numerical computation for a new way to reduce vibration and noise due to magnetostriction and magnetic forces of transformer cores

    NASA Astrophysics Data System (ADS)

    Zhu, Lihua; Yang, Qingxin; Yan, Rongge; Li, Yongjian; Zhang, Xian; Yan, Weili; Zhu, Jianguo

    2013-05-01

    Magnetostriction (MS) caused by the global magnetization of limbs and yokes and magnetic forces are the undisputed causes of the vibration and noise in power transformer cores. This paper presents a novel way to reduce the vibration and noise, in which nanocrystalline soft magnetic composite (NSMC) material with high permeability is used to fill the step-lap joint gaps of the power transformer magnetic cores. In order to numerically predict the effectiveness of the proposed method, a 3-D magneto-mechanical strong coupled model including MS and magnetic anisotropy of steel sheet was founded. Then, the numerical model was applied to analyze the step-lap joint region of the corner of magnetic cores. The analysis results illustrated that the deformation and noise of core with NSMC are lower than with the traditional epoxy damping material. Moreover, the validity of the proposed new way was verified by the simplified step-lap joint cores, which were achieved based on Epstein Frames.

  19. Accelerator Mass Spectrometric determination of radiocarbon in stratospheric CO2, retrieved from AirCore sampling.

    NASA Astrophysics Data System (ADS)

    Paul, Dipayan; Been, Henk A.; Chen, Huilin; Kivi, Rigel; Meijer, Harro A. J.

    2015-04-01

    In this decade, understanding the impact of human activities on climate is one of the key issues of discussion globally. The continuous rise in the concentration of greenhouse gases, e.g., CO2, CH4, etc. in the atmosphere, predominantly due to human activities, is alarming and requires continuous monitoring to understand the dynamics. Radiocarbon is an important atmospheric tracer and one of the many used in the understanding of the global carbon budget, which includes the greenhouse gases like CO2 and CH4. Measurement of 14C (or radiocarbon) in atmospheric CO2 generally requires collection of large air samples (few liters) from which CO2 is extracted and then the concentration of radiocarbon is determined. Currently, Accelerator Mass Spectrometry (AMS) is the most precise, reliable and widely used technique for atmospheric radiocarbon detection. However, the regular collection of air samples from troposphere and stratosphere, for example using aircraft, is prohibitively expensive. AirCore is an innovative atmospheric sampling system, developed by NOAA. It comprises of a long tube descending from a high altitude with one end open and the other closed, and has been demonstrated to be a reliable, cost-effective sampling system for high-altitude profile (up to ~ 30 km) measurements of CH4and CO2(Karion et al. 2010). In Europe, AirCore measurements are being performed on a regular basis near Sodankylä since September 2013. Here we describe the analysis of two such AirCore samples collected in July 2014, Finland, for determining the 14C concentration in stratospheric CO2. The two AirCore samples were collected on consecutive days. Each stratospheric AirCore sample was divided into six fractions, each containing ~ 35 μg CO2 (~9.5 μg C). Each fraction was separately trapped in 1 /4 inch coiled stainless steel tubing for radiocarbon measurements. The procedure for CO2 extraction from the stratospheric air samples; the sample preparation, with samples containing < 10

  20. Magnetic properties measurement and discussion of an amorphous power transformer core at room and liquid nitrogen temperature

    NASA Astrophysics Data System (ADS)

    Pronto, A. G.; Maurício, A.; Pina, J. M.

    2014-05-01

    In energy generation, transmission and distribution systems, power transformers are one of the most common and important components. Consequently, the performance of these transformers is crucial to global efficiency of the systems. To optimize transformers efficiency, the selection of an adequate ferromagnetic material is very important. For example, the use of amorphous ferromagnetic materials in transformer cores, replacing crystalline electrical steels, decreases total magnetic losses of the device. Other possible solution to increase energy systems efficiency, is the installation of high temperature superconducting power transformers (HTS transformers), normally cooled by liquid nitrogen at 77 K. In order to contribute to HTS transformer efficiency improvement, a 562.5 VA transformer with an amorphous ferromagnetic core was designed and built. For this core, the most important magnetic properties are measured at room and cryogenic temperature, and then compared with those of a typical crystalline grain-oriented electrical steel. Amorphous material magnetic losses (static and dynamic) at room and 77K are also presented and discussed.

  1. Fe-based composited cores for single-phase transformers fabricated with high-induction amorphous material

    NASA Astrophysics Data System (ADS)

    Hsu, Chang-Hung; Cheng, Shan-Jen; Lee, Chun-Yao; Fu, Chao-Ming; Chang, Chia-Wen

    2014-05-01

    A composite-structured, high-induction, double-layered soft magnetic composite core (SMC) comprised of magnetic amorphous HB1-M, HB1, and SA1 materials was developed. A finite element analysis simulated results for the magnetic loss and magnetic flux density for three types of amorphous cores are quite different from findings for traditional magnetic core structures, such as laminated silicon steel, because the magnetostriction and permeability properties of composite-laminated no-cutting structures can be restrained. The SMC structure showed interesting results for magnetic loss, magnetic flux lines, core vibration, and sound level. The main advantage of transformers assembled with composited-cores of SA1 and HB1 over a higher-induction core single-phase transformer is the significant reduction of magnetic loss. However, the SA1 and HB1 composite core also showed worse results in terms of vibration and sound level because the magnetostriction and magnetic flux density in the core distribution are not quite identical to the results for other core types.

  2. Orbital tuning of deep ice cores using O2/N2 of trapped air

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Aoki, S.; Nakazawa, T.

    2014-12-01

    The chronology of the first Dome Fuji deep ice core (80,000-340,000 yr BP) was established by orbital tuning of measured O2/N2 ratios in trapped air to the past local summer insolation at the drill site (Kawamura et al., 2007). The O2/N2 ratios found in ice cores are generally lower than atmospheric ratio because of size-dependent molecular fractionation during bubble close-off. The magnitude of this gas fractionation appears to be influenced by snow metamorphism when the layer was originally at the surface, which in turn is controlled by local summer insolation (Fujita et al., 2009). The O2/N2 record has little 100,000-yr periodicity (strongest in climatic records), suggesting insignificant climatic influence in the orbital tuning. Agreement of the O2/N2 chronology with U-Th radiometric chronology of speleothems (within ~2000 yr) suggests that O2/N2 and summer insolation are indeed in phase. However, it may not be common to all ice cores that O2/N2 signal only records local summer insolation. For example, the GISP2 ice core (Greenland) has clear imprint of abrupt climate changes in the O2/N2 record, indicating climatic (non-insolation) signal in the record and the possibility of phase variability of O2/N2 relative to the past insolation (Suwa and Bender, 2008). Here we present new O2/N2 record from the second Dome Fuji ice core with significant improvements in ice core storage practice and mass spectrometry. In particular, the ice core had been stored at about -50 ˚C until the air extraction except during transportations, which prevent fractionation due to gas loss during the core storage. The precision of the new O2/N2 data set is improved by a factor of 3 over the previous data, and we do not observe outliers (there were 15% outliers in the previous data). Clear imprint of local insolation is recognizable in the new O2/N2, which would enable us to generate a chronology with accuracy of ~2000 yr towards older periods. Samples from the first core after long

  3. MANURE NITROGEN TRANSFORMATIONS IN AIR, SOIL AND CROPS ON DAIRY FARMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only 25 to 35 % of the crude protein (CP) consumed by dairy cows is converted into milk. Such poor use of dietary CP may be due to inefficiencies associated with forage nitrogen (N) capture and metabolism. Manure N excreted in feces and urine, and the transformation of manure N in air, soil and crop...

  4. Electrical breakdown of transformer oil with sulfur hexafluoride and air bubbles

    NASA Astrophysics Data System (ADS)

    Gadzhiev, M. Kh.; Isakaev, E. Kh.; Tyuftyaev, A. S.; Akimov, P. L.; Yusupov, D. I.; Kulikov, Yu. M.; Panov, V. A.

    2015-07-01

    The influence of gas bubbles on the breakdown voltage of transformer oil is experimentally studied. The influence of the oil flow on the electrical characteristics of breakdown is analyzed. It is shown that sulfur hexafluoride and air bubbles decrease the breakdown voltage.

  5. A combined compensation method for the output voltage of an insulated core transformer power supply

    NASA Astrophysics Data System (ADS)

    Yang, L.; Yang, J.; Liu, K. F.; Qin, B.; Chen, D. Z.

    2014-06-01

    An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.

  6. A combined compensation method for the output voltage of an insulated core transformer power supply.

    PubMed

    Yang, L; Yang, J; Liu, K F; Qin, B; Chen, D Z

    2014-06-01

    An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA. PMID:24985809

  7. A combined compensation method for the output voltage of an insulated core transformer power supply

    SciTech Connect

    Yang, L.; Yang, J. Liu, K. F.; Qin, B.; Chen, D. Z.

    2014-06-15

    An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.

  8. A spectral transform dynamical core option within the Community Atmosphere Model (CAM4)

    SciTech Connect

    Evans, Katherine J; Mahajan, Salil; Branstetter, Marcia L; McClean, Julie L.; Caron, Julie M.; Maltrud, Matthew E.; Hack, James J; Bader, David C; Neale, Rich

    2014-01-01

    A spectral transform dynamical core with an 85 spectral truncation resolution (T85) within the Community Atmosphere Model (CAM), version 4, is evaluated within the recently released Community Earth System Model, version 1.0 (CESM) global climate model. The spectral dynamical core option provides a well-known base within the climate model community from which to assess climate behavior and statistics, and its relative computational efficiency for smaller computing platforms allows it to be extended to perform climate length simulations using high-resolution configurations in the near term. To establish the characteristics of the CAM4 T85, an ensemble of simulations covering the present day observational period using forced sea surface temperatures and prescribed sea-ice extent are evaluated. Overall, the T85 ensemble attributes and biases are similar to a companion ensemble of simulations using the one degree finite volume (FV1) dynamical core, relative to observed and model derived datasets. Notable improvements with T85 compared to FV1 include the representation of wintertime Arctic sea level pressure and summer precipitation over the Western Indian subcontinent. The mean and spatial patterns of the land surface temperature trends over the AMIP period are generally well simulated with the T85 ensemble relative to observations, however the model is not able to capture the extent nor magnitude of changes in temperature extremes over the boreal summer, where the changes are most dramatic. Biases in the wintertime Arctic surface temperature and annual mean surface stress fields persist with T85 as with the CAM3 version of T85.

  9. A three-phase three-winding core-type transformer model for low-frequency transient studies

    SciTech Connect

    Chen, X.; Venkata, S.S.

    1997-04-01

    A topology-based and duality-derived three-phase, three-winding, core-type transformer model is presented. The model treats the leakage inductances and the coupling effects of the core in a straightforward and integrated way. The long-established positive- and zero-sequence star equivalent circuits of a three-phase three-winding transformer are derived from the original equivalent magnetic circuit of the transformer by applying duality. Formulations for determining the values of the leakage inductances and the core loss resistances from transformer open- and short-circuit test data are presented. A supporting routine is written to generate the {lambda}-i curves for each segment of the core and the other input data for EMTP. Since the duality-derived model consists of only RLC elements, no device-specific code to EMTP time-step code is needed. Winding capacitances are lumped to the terminals. The model is suitable for simulation of power system low-frequency transients such as inrush currents and ferroresonance, short circuits, and abnormalities including transformer winding faults.

  10. Distinctive diamagnetic fabrics in dolostones evolved at fault cores, the Dead Sea Transform

    NASA Astrophysics Data System (ADS)

    Braun, D.; Weinberger, R.; Eyal, Y.; Feinstein, S.; Harlavan, Y.; Levi, T.

    2015-08-01

    We resolve the anisotropy of magnetic susceptibility (AMS) axes along fault planes, cores and damage zones in rocks that crop out next to the Dead Sea Transform (DST) plate boundary. We measured 261 samples of mainly diamagnetic dolostones that were collected from 15 stations. To test the possible effect of the iron content on the AMS we analyzed the Fe concentrations of the samples in different rock phases. Dolostones with mean magnetic susceptibility value lower than -4 × 10-6 SI and iron content less than ∼1000 ppm are suitable for diamagnetic AMS-based strain analysis. The dolostones along fault planes display AMS fabrics that significantly deviate from the primary "sedimentary fabric". The characteristics of these fabrics include well-grouped, sub-horizontal, minimum principal AMS axes (k3) and sub-vertical magnetic foliations commonly defined by maximum and intermediate principal AMS axes (k1 and k2 axes, respectively). These fabrics are distinctive along fault planes located tens of kilometers apart, with strikes ranging between NNW-SSE and NNE-SSW and different senses of motion. The obtained magnetic foliations (k1-k2) are sub-parallel (within ∼20°) to the fault planes. Based on rock magnetic and geochemical analyses, we interpret the AMS fabrics as the product of both shape and crystallographic anisotropy of the dolostones. Preferred shape alignment evolves due to mechanical rotation of subordinate particles and rock fragments at the fault core. Preferred crystallographic orientation results from elevated frictional heating (>300 °C) during faulting, which enhances c-axes alignment in the cement-supported dolomite breccia due to crystal-plastic processes. The penetrative deformation within fault zones resulted from the local, fault-related strain field and does not reflect the regional strain field. The analyzed AMS fabrics together with fault-plane kinematics provide valuable information on faulting characteristics in the uppermost crust.

  11. Development of Yangbajing air shower core detector for a new EAS hybrid experiment

    NASA Astrophysics Data System (ADS)

    Liu, Jin-Sheng; Huang, Jing; Chen, Ding; Zhang, Ying; Zhai, Liu-Ming; Chen, Xu; Hu, Xiao-Bin; Lin, Yu-Hui; Zhang, Xue-Yao; Feng, Cun-Feng; Jia, Huan-Yu; Zhou, Xun-Xiu; Danzengluobu; Chen, Tian-Lu; Li, Hai-Jin; Liu, Mao-Yuan; Yuan, Ai-Fang

    2015-08-01

    Aiming at the observation of cosmic-ray chemical composition in the “knee” energy region, we have been developing a new type of air-shower core detector (YAC, Yangbajing Air shower Core detector array) to be set up at Yangbajing (90.522° E, 30.102° N, 4300 m above sea level, atmospheric depth: 606 g/m2) in Tibet, China. YAC works together with the Tibet air-shower array (Tibet-III) and an underground water Cherenkov muon detector array (MD) as a hybrid experiment. Each YAC detector unit consists of lead plates of 3.5 cm thickness and a scintillation counter which detects the burst size induced by high energy particles in the air-shower cores. The burst size can be measured from 1 MIP (Minimum Ionization Particle) to 106 MIPs. The first phase of this experiment, named “YAC- I”, consists of 16 YAC detectors each with a size of 40 cm×50 cm and distributed in a grid with an effective area of 10 m2. YAC- I is used to check hadronic interaction models. The second phase of the experiment, called “YAC- II”, consists of 124 YAC detectors with coverage of about 500 m2. The inner 100 detectors of 80 cm×50 cm each are deployed in a 10×10 matrix with a 1.9 m separation; the outer 24 detectors of 100 cm×50 cm each are distributed around these to reject non-core events whose shower cores are far from the YAC- II array. YAC- II is used to study the primary cosmic-ray composition, in particular, to obtain the energy spectra of protons, helium and iron nuclei between 5×1013 eV and 1016 eV, covering the “knee” and also connected with direct observations at energies around 100 TeV. We present the design and performance of YAC- II in this paper. Supported by grants from the National Natural Science Foundation of China (11078002, 11275212, 11165013), the Chinese Academy of Sciences (H9291450S3, Y4293211S5) and the Knowledge Innovation Fund of Institute of High Energy Physics (IHEP), China (H95451D0U2, H8515530U1)

  12. Transformational Opportunities: Language and Literacy Instruction for English Language Learners in the Common Core Era in the United States

    ERIC Educational Resources Information Center

    Kibler, Amanda K.; Walqui, Aída; Bunch, George C.

    2015-01-01

    New demands of the Common Core State Standards imply instructional transformations for all classrooms in the United States, but teachers of students designated as English language learners (ELLs) are among those most likely to feel the impact in their daily professional lives. Language is an integral part of classroom learning in all subject…

  13. Lightweight transformer

    SciTech Connect

    Swallom, D.W.; Enos, G.

    1990-05-01

    The technical effort described in this report relates to the program that was performed to design, fabricate, and test a lightweight transformer for Strategic Defense Initiative Organization (SDIO) mission requirements. The objectives of this program were two-fold: (1) design and fabricate a lightweight transformer using liquid hydrogen as the coolant; and (2) test the completed transformer assembly with a low voltage, dc power source. Although the full power testing with liquid helium was not completed, the program demonstrated the viability of the design approach. The lightweight transformer was designed and fabricated, and low and moderate power testing was completed. The transformer is a liquid hydrogen cooled air core transformer that uses thin copper for its primary and secondary windings. The winding mass was approximately 12 kg, or 0.03 kg/kW. Further refinements of the design to a partial air core transformer could potentially reduce the winding mass to as low as 4 or 5 kg, or 0.0125 kg/kW. No attempt was made on this program to reduce the mass of the related structural components or cryogenic container. 8 refs., 39 figs., 2 tabs.

  14. Inorganic nitrogen transformations in the bed of the Shingobee River, Minnesota: Integrating hydrologic and biological processes using sediment perfusion cores

    USGS Publications Warehouse

    Sheibley, R.W.; Duff, J.H.; Jackman, A.P.; Triska, F.J.

    2003-01-01

    Inorganic N transformations were examined in streambed sediments from the Shingobee River using sediment perfusion cores. The experimental design simulated groundwater-stream water mixing within sediment cores, which provided a well-defined one-dimensional representation of in situ hydrologic conditions. Two distinct hydrologic and chemical settings were preserved in the sediment cores: the lowermost sediments, perfused with groundwater, remained anaerobic during the incubations, whereas the uppermost sediments, perfused with oxic water pumped from the overlying water column, simulated stream water penetration into the bed. The maintenance of oxic and anoxic zones formed a biologically active aerobic-anaerobic interface. Ammonium (NH4+) dissolved in groundwater was transported conservatively through the lower core zone but was removed as it mixed with aerated recycle water. Concurrently, a small quantity of nitrate (NO3-) equaling ???25% of the NH4+ loss was produced in the upper sediments. The NH4+ and NO3- profiles in the uppermost sediments resulted from coupled nitrification-denitrification, because assimilation and sorption were negligible. We hypothesize that anaerobic microsites within the aerated upper sediments supported denitrification. Rates of nitrification and denitrification in the perfusion cores ranged 42-209 and 53-160 mg N m-2 day-1, respectively. The use of modified perfusion cores permitted the identification and quantification of N transformations and verified process control by surface water exchange into the shallow hyporheic zone of the Shingobee River.

  15. An investigation of polarization cross-coupling in air-core photonic bandgap fibers

    NASA Astrophysics Data System (ADS)

    Xu, Xiaobin; Song, Ningfang; Zhang, Zhihao; Zhang, Zuchen; Jin, Jing; Zhang, Chunxi

    2016-05-01

    Polarization cross-coupling is one of the most important problems in air-core photonic bandgap fibers (PBF). In this research, polarization cross-coupling is investigated for PBFs of different lengths. The analyzing and simulation results show that the orientation of the birefringent axes induced by residual core ellipticity fluctuates with an average period of ~2.5 cm and random angles uniformly distributed over approximately [-7.5°, 7.5°]. The birefringent orientation in PBF varies much more frequently and strongly than that in any conventional fiber because of the difference in drawing process, and this is the most important factor causing the strong polarization cross-coupling in PBFs.

  16. Tracking the Transformation and Preservation of Organic Biomarkers in a Varved Sediment-Core Series

    NASA Astrophysics Data System (ADS)

    Tolu, J.; Bigler, C.; Bindler, R.

    2014-12-01

    An important premise for reconstructing environmental changes using sediment records is to understand which environmental information reaches the lake bottom and how diagenetic processes may affect the proxies, such as terrestrial and aquatic organic biomarkers. We can tackle this question using a unique series of varved sediment cores collected from the lake Nylandssjön (northern Sweden). In addition to limnological and sediment trap sampling since 2001, we have a collection of freeze cores taken in late winter and stored since 1979, which allows us to track individual varve years (e.g., 1978) over time (~30 years). A previous study using this collection showed that 23 % of C and 35 % of N were lost during the first 25 years with a C:N ratio increase of ≈21, suggesting important implications for diagenetic effects on organic biomarkers. To assess the preservation/transformation of organic biomarkers, we developed a new Pyrolysis-Gas Chromatography/Mass Spectrometry method that allows the rapid determination of biomarkers from the common OM classes (e.g., plant waxes, microbial lipids, lignins) using sub-mg sample sizes and thus applicable to high-resolution sampling of the varved sediment (Tolu et al., under review). Our results show that the different biomarkers exhibit a broad spectrum of reactivities over ~30 years -% change determined by ([Peak area at t] - [Peak area at t=0])/ [peak area at t=0] x 100-. For example: 67-80 % of the algal chlorophyll-derived product 'phytene' is lost depending which single varve year is followed over time (e.g., 1979). Only 12-32 % of "pristene", the degraded form of algal chlorophyll, is lost. The guaiacyl and syringyl lignin units are affected by a smaller loss, i.e. 5-15 %, and the S/G ratio, indicative of angiosperm/gymnosperm plant input remains stable, which is contrary to previous work on non-varved lake sediments. Considering all biomarkers, the degradation/production plateaued after ~15 years, which indicates that

  17. Piezoelectric transformers for low-voltage generation of gas discharges and ionic winds in atmospheric air

    SciTech Connect

    Johnson, Michael J.; Go, David B.

    2015-12-28

    To generate a gas discharge (plasma) in atmospheric air requires an electric field that exceeds the breakdown threshold of ∼30 kV/cm. Because of safety, size, or cost constraints, the large applied voltages required to generate such fields are often prohibitive for portable applications. In this work, piezoelectric transformers are used to amplify a low input applied voltage (<30 V) to generate breakdown in air without the need for conventional high-voltage electrical equipment. Piezoelectric transformers (PTs) use their inherent electromechanical resonance to produce a voltage amplification, such that the surface of the piezoelectric exhibits a large surface voltage that can generate corona-like discharges on its corners or on adjacent electrodes. In the proper configuration, these discharges can be used to generate a bulk air flow called an ionic wind. In this work, PT-driven discharges are characterized by measuring the discharge current and the velocity of the induced ionic wind with ionic winds generated using input voltages as low as 7 V. The characteristics of the discharge change as the input voltage increases; this modifies the resonance of the system and subsequent required operating parameters.

  18. Piezoelectric transformers for low-voltage generation of gas discharges and ionic winds in atmospheric air

    NASA Astrophysics Data System (ADS)

    Johnson, Michael J.; Go, David B.

    2015-12-01

    To generate a gas discharge (plasma) in atmospheric air requires an electric field that exceeds the breakdown threshold of ˜30 kV/cm. Because of safety, size, or cost constraints, the large applied voltages required to generate such fields are often prohibitive for portable applications. In this work, piezoelectric transformers are used to amplify a low input applied voltage (<30 V) to generate breakdown in air without the need for conventional high-voltage electrical equipment. Piezoelectric transformers (PTs) use their inherent electromechanical resonance to produce a voltage amplification, such that the surface of the piezoelectric exhibits a large surface voltage that can generate corona-like discharges on its corners or on adjacent electrodes. In the proper configuration, these discharges can be used to generate a bulk air flow called an ionic wind. In this work, PT-driven discharges are characterized by measuring the discharge current and the velocity of the induced ionic wind with ionic winds generated using input voltages as low as 7 V. The characteristics of the discharge change as the input voltage increases; this modifies the resonance of the system and subsequent required operating parameters.

  19. The Influence of the Material of the Transformer Core on Characteristics of the Selected DC-DC Converters

    NASA Astrophysics Data System (ADS)

    Górecki, Krzysztof; Zarębski, Janusz

    In the paper the influence of the ferromagnetic material used for the construction of the core of the impulse-transformer on the characteristics of a half-bridge converter is considered. The investigated network is described and some results of measurements are shown. On the basis of the obtained characteristics of the investigated converters some suggestions for the designers of such circuits are formulated.

  20. Transformation of Sulfur Species during Steam/Air Regeneration on a Ni Biomass Conditioning Catalyst

    SciTech Connect

    Yung, M. M.; Cheah, S.; Magrini-Bair, K.; Kuhn, J. N.

    2012-07-06

    Sulfur K-edge XANES identified transformation of sulfides to sulfates during combined steam and air regeneration on a Ni/Mg/K/Al2O3 catalyst used to condition biomass-derived syngas. This catalyst was tested over multiple reaction/regeneration/reduction cycles. Postreaction catalysts showed the presence of sulfides on H2S-poisoned sites. Although H2S was observed to leave the catalyst bed during regeneration, sulfur remained on the catalyst, and a transformation from sulfides to sulfates was observed. Following the oxidative regeneration, the subsequent H2 reduction led to a partial reduction of sulfates back to sulfides, indicating the difficulty and sensitivity in achieving complete sulfur removal during regeneration for biomass-conditioning catalysts.

  1. Transformations in understanding the health impacts of air pollutants in the 20th century

    NASA Astrophysics Data System (ADS)

    Brimblecombe, P.

    2009-02-01

    The transformations of air pollution in the 20th century are well known. The century opened with urban atmospheres polluted by the combustion products of burning coal: smoke and sulfur dioxide. At the millennium these pollutants had almost vanished, replaced by the pollutants, both primary and secondary, a function of fossil-fuelled vehicles. However transitions in terms of health outcomes have been equally dramatic. Fine particulate matter causes notable cardiovascular problems such as increased incidence of stroke and heart attack, although the mechanism remains somewhat unclear. Cancer inducing air pollutants remain a concern, but in addition more recently there has been a rising interest in the presence of neurotoxins and endocrine disrupting substances in the environment.

  2. Phase relationships between orbital forcing and the composition of air trapped in Antarctic ice cores

    NASA Astrophysics Data System (ADS)

    Bazin, Lucie; Landais, Amaelle; Capron, Emilie; Masson-Delmotte, Valérie; Ritz, Catherine; Picard, Ghislain; Jouzel, Jean; Dumont, Marie; Leuenberger, Markus; Prié, Frédéric

    2016-03-01

    Orbital tuning is central for ice core chronologies beyond annual layer counting, available back to 60 ka (i.e. thousands of years before 1950) for Greenland ice cores. While several complementary orbital tuning tools have recently been developed using δ18Oatm, δO2⁄N2 and air content with different orbital targets, quantifying their uncertainties remains a challenge. Indeed, the exact processes linking variations of these parameters, measured in the air trapped in ice, to their orbital targets are not yet fully understood. Here, we provide new series of δO2/N2 and δ18Oatm data encompassing Marine Isotopic Stage (MIS) 5 (between 100 and 160 ka) and the oldest part (340-800 ka) of the East Antarctic EPICA Dome C (EDC) ice core. For the first time, the measurements over MIS 5 allow an inter-comparison of δO2/N2 and δ18Oatm records from three East Antarctic ice core sites (EDC, Vostok and Dome F). This comparison highlights some site-specific δO2/N2 variations. Such an observation, the evidence of a 100 ka periodicity in the δO2/N2 signal and the difficulty to identify extrema and mid-slopes in δO2/N2 increase the uncertainty associated with the use of δO2/N2 as an orbital tuning tool, now calculated to be 3-4 ka. When combining records of δ18Oatm and δO2/N2 from Vostok and EDC, we find a loss of orbital signature for these two parameters during periods of minimum eccentricity (˜ 400 ka, ˜ 720-800 ka). Our data set reveals a time-varying offset between δO2/N2 and δ18Oatm records over the last 800 ka that we interpret as variations in the lagged response of δ18Oatm to precession. The largest offsets are identified during Terminations II, MIS 8 and MIS 16, corresponding to periods of destabilization of the Northern polar ice sheets. We therefore suggest that the occurrence of Heinrich-like events influences the response of δ18Oatm to precession.

  3. Structural transformation of the amyloidogenic core region of TDP-43 protein initiates its aggregation and cytoplasmic inclusion.

    PubMed

    Jiang, Lei-Lei; Che, Mei-Xia; Zhao, Jian; Zhou, Chen-Jie; Xie, Mu-Yun; Li, Hai-Yin; He, Jian-Hua; Hu, Hong-Yu

    2013-07-01

    TDP-43 (TAR DNA-binding protein of 43 kDa) is a major deposited protein in amyotrophic lateral sclerosis and frontotemporal dementia with ubiquitin. A great number of genetic mutations identified in the flexible C-terminal region are associated with disease pathologies. We investigated the molecular determinants of TDP-43 aggregation and its underlying mechanisms. We identified a hydrophobic patch (residues 318-343) as the amyloidogenic core essential for TDP-43 aggregation. Biophysical studies demonstrated that the homologous peptide formed a helix-turn-helix structure in solution, whereas it underwent structural transformation from an α-helix to a β-sheet during aggregation. Mutation or deletion of this core region significantly reduced the aggregation and cytoplasmic inclusions of full-length TDP-43 (or TDP-35 fragment) in cells. Thus, structural transformation of the amyloidogenic core initiates the aggregation and cytoplasmic inclusion formation of TDP-43. This particular core region provides a potential therapeutic target to design small-molecule compounds for mitigating TDP-43 proteinopathies. PMID:23689371

  4. Millennial and Sub-millennial Variability of Total Air Content from the WAIS Divide Ice Core

    NASA Astrophysics Data System (ADS)

    Edwards, Jon; Brook, Edward; Fegyveresi, John; Lee, James; Mitchell, Logan; Sowers, Todd; Alley, Richard; McConnell, Joe; Severinghaus, Jeff; Baggenstos, Daniel

    2014-05-01

    The analysis of ancient air bubbles trapped in ice is integral to the reconstruction of climate over the last 800 ka. While mixing ratios of greenhouse gases along with isotopic ratios are being studied in ever increasing resolution, one aspect of the gas record that continues to be understudied is the total air content (TAC) of the trapped bubbles. Published records of TAC are often too low in temporal resolution to adequately capture sub-millennial scale variability. Here we present a high-resolution TAC record (10-50 year sampling resolution) from the WAIS Divide ice core, measured at Oregon State and Penn State Universities. The records cover a variety of climatic conditions over the last 56 ka and show millennial variability of up to 10% and sub-millennial variability between 2.5 and 3.5%. We find that using the pore close off volume parameterization (Delomotte et al., J. Glaciology, 1999, v.45), along with the site temperature derived from isotopes, our TAC record implies unrealistically large changes in surface pressure or elevation. For example, the TAC decreases by ~10% between 19.5ka and 17.3ka, and would imply an elevation increase of nearly 800m. The total accumulation of ice over this period is just 280m (Fudge et al. Nature 2013), making the calculated elevation interpretation implausible. To resolve this discrepancy, we investigate the millennial and sub-millennial variability in our TAC record as a function of changes in firn densification and particularly layering. The firn is the uppermost layer of an ice sheet where snow is compressed into ice, trapping ancient air. Thus firn processes are important for the interpretation of total air content as well as other gas records. We compare our TAC record with proxies for dust, temperature and accumulation to determine how processes other than elevation affect TAC.

  5. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.

    PubMed

    Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J

    2013-12-01

    We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems. PMID:24514492

  6. Compression-Induced Fusion of Glassy Core Polymer Micelles at the Air-Water Interface

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Chang; Won, You-Yeon

    The surface mechanical and morphological properties of glassy core polymer micelles at the air-water interface were investigated. Asymmetric PS-PEG and PtBMA-PEG block copolymers with PEG weight fractions larger than 0.5 were formulated in the form of aqueous micelles and spread onto water. Compressed films of PS-PEG and PtBMA-PEG micelles reach high dynamic surface pressures. On the detailed level, however, PS-PEG and PtBMA-PEG micelles exhibit different surface pressure-area profiles. The PtBMA-PEG isotherm shows a transition to a plateau around a surface pressure of 24 mN/m, which is attributed to the PtBMA block as it forms a continuous film; this interpretation is supported by the fact that the surface pressure at the plateau transition is identical to the value of the spreading coefficient for PtBMA. This presents evidence that the core domains of PtBMA-PEG micelles melt and merge into a film when the micellar monolayer is laterally compressed. Such behavior was not observed with PS-PEG micelles. We suspect that under lateral compression, PtBMA-PEG micelles undergo fusion into a continuous film because PtBMA has the natural tendency to spread on the water surface, whereas PS-PEG micelles does not because the dewetting tendency of PS preventing formation of a uniform layer.

  7. The impact of drought and air pollution on metal profiles in peat cores.

    PubMed

    Souter, Laura; Watmough, Shaun A

    2016-01-15

    Peat cores have long been used to reconstruct atmospheric metal deposition; however, debate remains regarding how well historical depositional patterns are preserved in peat. This study examined peat cores sampled from 14 peatlands in the Sudbury region of Ontario, Canada, which has a well-documented history of acid and metal deposition. Copper (Cu) and lead (Pb) concentrations within individual peat cores were strongly correlated and were elevated in the upper 10 cm, especially in the sites closest to the main Copper Cliff smelter. In contrast, nickel (Ni) and cobalt (Co) concentrations were often elevated at depths greater than 10 cm, indicating much greater post-depositional movement of these metals compared with Cu and Pb. Post-depositional movement of metals is supported by the observation that Ni and Co concentrations in peat pore water increased by approximately 530 and 960% for Ni and Co, respectively between spring and summer due to drought-induced acidification, but there was much less change in Cu concentration. Sphagnum cover and (210)Pb activity measured at 10 cm at the 14 sites significantly increased with distance from Copper Cliff, and the surface peat von Post score decreased with distance from Copper Cliff, indicating the rate of peat formation increases with distance from Sudbury presumably as a result of improved Sphagnum survival. This study shows that the ability of peat to preserve deposition histories of some metals is strongly affected by drought-induced post-depositional movement and that loss of Sphagnum due to air pollution impairs the rate of peat formation, further affecting metal profiles in peatlands. PMID:26473705

  8. Measurement of effective air diffusion coefficients for trichloroethene in undisturbed soil cores

    NASA Astrophysics Data System (ADS)

    Bartelt-Hunt, Shannon L.; Smith, James A.

    2002-06-01

    In this study, we measure effective diffusion coefficients for trichloroethene in undisturbed soil samples taken from Picatinny Arsenal, New Jersey. The measured effective diffusion coefficients ranged from 0.0053 to 0.0609 cm 2/s over a range of air-filled porosity of 0.23-0.49. The experimental data were compared to several previously published relations that predict diffusion coefficients as a function of air-filled porosity and porosity. A multiple linear regression analysis was developed to determine if a modification of the exponents in Millington's [Science 130 (1959) 100] relation would better fit the experimental data. The literature relations appeared to generally underpredict the effective diffusion coefficient for the soil cores studied in this work. Inclusion of a particle-size distribution parameter, d10, did not significantly improve the fit of the linear regression equation. The effective diffusion coefficient and porosity data were used to recalculate estimates of diffusive flux through the subsurface made in a previous study performed at the field site. It was determined that the method of calculation used in the previous study resulted in an underprediction of diffusive flux from the subsurface. We conclude that although Millington's [Science 130 (1959) 100] relation works well to predict effective diffusion coefficients in homogeneous soils with relatively uniform particle-size distributions, it may be inaccurate for many natural soils with heterogeneous structure and/or non-uniform particle-size distributions.

  9. Pulse generators based on air-insulated linear-transformer-driver stages

    NASA Astrophysics Data System (ADS)

    Kovalchuk, B. M.; Kharlov, A. V.; Kumpyak, E. V.; Zherlitsyn, A. A.

    2013-05-01

    In this paper we present the design and test results of pulse generators based on air-insulated linear-transformer-driver stages that drive a vacuum transmission line. A custom designed unit, referred to as a capacitor block, was developed for use as a main structural element of the transformer stages. It incorporates two capacitors GA 35426 (40 nF, 100 kV) and a multichannel multigap gas switch. Two types of stages were developed: (1) stage LTD-20 with four modules in parallel and five capacitor blocks in each module (in tests of this stage current amplitude up to 850 kA with ˜140ns rise time was obtained on a 0.05Ω load at 100 kV charging voltage); (2) stage LTD-4 with two modules in parallel and two capacitor blocks in each module. Several installations were built on the base of these stages, including a linear transformer, consisting of two identical LTD-20 stages in series, and a high power electron accelerator on the base of LTD-4 stages. The design, tests results, and main problems are presented and discussed in this paper for these installations.

  10. Effects of a Circulating-water Garment and Forced-air Warming on Body Heat Content and Core Temperature

    PubMed Central

    Taguchi, Akiko; Ratnaraj, Jebadurai; Kabon, Barbara; Sharma, Neeru; Lenhardt, Rainer; Sessler, Daniel I.

    2005-01-01

    Background: Forced-air warming is sometimes unable to maintain perioperative normothermia. We therefore compared heat transfer, regional heat distribution, and core rewarming of forced-air warming with a novel circulating-water garment. Methods: Nine volunteers were each evaluated on two randomly ordered study days. They were anesthetized and cooled to a core temperature near 34°C. The volunteers were subsequently warmed for 2.5 hours with either a circulating-water garment or forced-air cover. Overall, heat balance was determined from the difference between cutaneous heat loss (thermal flux transducers) and metabolic heat production (oxygen consumption). Average arm and leg (peripheral) tissue temperatures were determined from 18 intramuscular needle thermocouples, 15 skin thermal flux transducers, and “deep” arm and foot thermometers. Results: Heat production (≈ 60 kcal/h) and loss (≈45 kcal/h) were similar with each treatment before warming. The increase in heat transfer across anterior portions of the skin surface was similar with each warming system (≈65 kcal/h). Forced-air warming had no effect on posterior heat transfer whereas circulating-water transferred 21 ± 9 kcal/h through the posterior skin surface after a half hour of warming. Over 2.5 h, circulating-water thus increased body heat content 56% more than forced air. Core temperatures thus increased faster than with circulating water than forced air, especially during the first hour, with the result that core temperature was 1.1 ± 0.7°C greater after 2.5 h (P < 0.001). Peripheral tissue heat content increased twice as much as core heat content with each device, but the core-to-peripheral tissue temperature gradient remained positive throughout the study. Conclusions: The circulating-water system transferred more heat than forced air, with the difference resulting largely from posterior heating. Circulating water rewarmed patients 0.4°C/h faster than forced air. A substantial peripheral-to-core

  11. Inert gas purgebox for Fourier transform ion cyclotron resonance mass spectrometry of air-sensitive solids

    NASA Astrophysics Data System (ADS)

    May, Michael A.; Marshall, Alan G.

    1994-03-01

    A sealed rigid ``purgebox'' makes it possible to load air- and/or moisture-sensitive solids into the solids probe inlet of a Fourier transform ion cyclotron resonance (FT/ICR) mass spectrometer. A pelletized sample is transferred (in a sealed canister) from a commercial drybox to a Lucite(R) purgebox. After the box is purged with inert gas, an attached glove manipulator is used to transfer the sample from the canister to the solids probe of the mass spectrometer. Once sealed inside the inlet, the sample is pre-evacuated and then passed into the high vacuum region of the instrument at ˜10-7 Torr. The purgebox is transparent, portable, and readily assembled/disassembled. Laser desorption FT/ICR mass spectra of the air- and moisture-sensitive solids, NbCl5. NbCl2(C5H5)2, and Zr(CH3)2(C5H5)2 are obtained without significant oxidation. The residual water vapor concentration inside the purgebox was measured as 100±20 ppm after a 90-min purge with dry nitrogen gas. High-resolution laser desorption/ionization mass spectrometry of air-sensitive solids becomes feasible with the present purgebox interface. With minor modification of the purgebox geometry, the present method could be adapted to any mass spectrometer equipped with a solid sample inlet.

  12. Diaplectic transformation of minerals: Vorotilov drill core, Puchezh-Katunki impact crater, Russia

    NASA Technical Reports Server (NTRS)

    Feldman, V. I.

    1992-01-01

    The Vorotilov core was drilled in the central uplift of the Puchezh-Katunki astrobleme to a depth of 5.1 km. Impactites are revealed in the rocks of the core beginning from a depth of 366 m: suevites (66 m), allogenic breccias (112 m), and autogenic breccias (deeper than 544 m). These rocks are represented by shocked-metamorphic gneisses, schists, amphibolites of Archean age, and magmatic rocks (dolerites, olivines, and peridotites) that lie between them.

  13. Transforming powder mechanical properties by core/shell structure: compressible sand.

    PubMed

    Shi, Limin; Sun, Changquan Calvin

    2010-11-01

    Some active pharmaceutical ingredients possess poor mechanical properties and are not suitable for tableting. Using fine sand (silicon dioxide), we show that a core/shell structure, where a core particle (sand) is coated with a thin layer of polyvinylpyrrolidone (PVP), can profoundly improve powder compaction properties. Sand coated with 5% PVP could be compressed into intact tablets. Under a given compaction pressure, tablet tensile strength increases dramatically with the amount of coating. This is in sharp contrast to poor compaction properties of physical mixtures, where intact tablets cannot be made when PVP content is 20% or less. The profoundly improved tabletability of core/shell particles is attributed to the formation of a continuous three-dimensional bonding network in the tablet. PMID:20845444

  14. TRANSFORMATION

    SciTech Connect

    LACKS,S.A.

    2003-10-09

    Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

  15. Measuring air core characteristics of a pressure-swirl atomizer via a transparent acrylic nozzle at various Reynolds numbers

    SciTech Connect

    Lee, Eun J.; Oh, Sang Youp; Kim, Ho Y.; Yoon, Sam S.; James, Scott C.

    2010-11-15

    Because of thermal fluid-property dependence, atomization stability (or flow regime) can change even at fixed operating conditions when subject to temperature change. Particularly at low temperatures, fuel's high viscosity can prevent a pressure-swirl (or simplex) atomizer from sustaining a centrifugal-driven air core within the fuel injector. During disruption of the air core inside an injector, spray characteristics outside the nozzle reflect a highly unstable, nonlinear mode where air core length, Sauter mean diameter (SMD), cone angle, and discharge coefficient variability. To better understand injector performance, these characteristics of the pressure-swirl atomizer were experimentally investigated and data were correlated to Reynolds numbers (Re). Using a transparent acrylic nozzle, the air core length, SMD, cone angle, and discharge coefficient are observed as a function of Re. The critical Reynolds numbers that distinguish the transition from unstable mode to transitional mode and eventually to a stable mode are reported. The working fluids are diesel and a kerosene-based fuel, referred to as bunker-A. (author)

  16. A compact, high-voltage pulsed charging system based on an air-core pulse transformer.

    PubMed

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Liu, Chebo; Yin, Yi

    2015-09-01

    Charging systems of pulsed power generators on mobile platforms are expected to be compact and provide high pulsed power, high voltage output, and high repetition rate. In this paper, a high-voltage pulsed charging system with the aforementioned characteristics is introduced, which can be applied to charge a high-voltage load capacitor. The operating principle of the system and the technical details of the components in the system are described in this paper. The experimental results show that a 600 nF load capacitor can be charged to 60 kV at 10 Hz by the high-voltage pulsed charging system for a burst of 0.5 s. The weight and volume of the system are 60 kg and 600 × 500 × 380 mm(3), respectively. PMID:26429466

  17. Stationary rotary force waves on the liquid-air core interface of a swirl atomizer

    NASA Astrophysics Data System (ADS)

    Chinn, J. J.; Cooper, D.; Yule, A. J.; Nasr, G. G.

    2015-11-01

    A one-dimensional wave equation, applicable to the waves on the surface of the air-core of a swirl atomizer is derived analytically, by analogy to the similar one-dimensional wave equation derivation for shallow-water gravity waves. In addition an analogy to the flow of water over a weir is used to produce an analytical derivation of the flow over the lip of the outlet of a swirl atomizer using the principle of maximum flow. The principle of maximum flow is substantiated by reference to continuity of the discharge in the direction of streaming. For shallow-water gravity waves, the phase velocity is the same expression as for the critical velocity over the weir. Similarly, in the present work, the wave phase velocity on the surface of the air-core is shown to be the same expression as for the critical velocity for the flow at the outlet. In addition, this wave phase velocity is shown to be the square root of the product of the radial acceleration and the liquid thickness, as analogous with the wave phase velocity for shallow water gravity waves, which is the square root of the product of the acceleration due to gravity and the water depth. The work revisits the weirs and flumes work of Binnie et al. but using a different methodology. The results corroborate with the work of Binnie. High speed video, Laser Doppler Anemometry and deflected laser beam experimental work has been carried out on an oversize Perspex (Plexiglas) swirl atomizer. Three distinctive types of waves were detected: helical striations, low amplitude random ripples and low frequency stationary waves. It is the latter wave type that is considered further in this article. The experimentally observed waves appear to be stationary upon the axially moving flow. The mathematical analysis allows for the possibility of a negative value for the phase velocity expression. Therefore the critical velocity and the wave phase velocity do indeed lead to stationary waves in the atomizer. A quantitative comparison

  18. Electromagnetic characterization of current transformer with toroidal core under sinusoidal conditions

    NASA Astrophysics Data System (ADS)

    Koprivica, Branko; Milovanovic, Alenka

    2016-04-01

    The aim of this paper is to present a new procedure for the electromagnetic analysis of a measuring current transformer under sinusoidal conditions in its electrical and magnetic circuit. The influence of the magnetic hysteresis has been taken into account using the measured inverse magnetization curve and phase lag between the time waveforms of the magnetic field and the magnetic induction. Using the proposed analysis, ratio and phase errors of the current transformer have been calculated. The results of the calculation have been compared with experimental results and a good agreement has been found.

  19. Transforming the Core Business of Teaching and Learning in Classrooms through ICT

    ERIC Educational Resources Information Center

    Chandra, Vinesh; Mills, Kathy A.

    2015-01-01

    Information and Communication Technology (ICT) has become an integral part of societies across the globe. This study demonstrates how successful technology integration by 10 experienced teachers in an Australian high school was dependent on teacher-driven change and innovation that influenced the core business of teaching and learning. The…

  20. The Development of Artistic Style: Transformations of a Creator's Core Dilemma.

    ERIC Educational Resources Information Center

    Cohen-Shalev, Amir

    1993-01-01

    In the works of the playwright Pierre Corneille, the core dilemma of love versus duty, which underlay the artist's endeavors, evolved from the stage of articulation or problem finding in early adulthood, to dilemma resolution at midlife, and finally to dilemma fragmentation in old age. Argues that the dialectical tensions underlying creativity are…

  1. Lateral distribution of high energy hadrons and gamma ray in air shower cores observed with emulsion chambers

    NASA Technical Reports Server (NTRS)

    Matano, T.; Machida, M.; Honda, K.; Hashimoto, K.; Navia, C. E.; Kawasumi, N.; Tsushima, I.; Matinic, N.; Aquirre, C.

    1985-01-01

    A high energy event of a bundle of electrons, gamma rays and hadronic gamma rays in an air shower core were observed. The bundles were detected with an emulsion chamber with thickness of 15 cm lead. This air shower is estimated to be initiated with a proton with energy around 10 to the 17th power to 10 to the 18th power eV at an altitude of around 100 gmc/2. Lateral distributions of the electromagnetic component with energy above 2 TeV and also the hadronic component of energy above 6 TeV of this air shower core were determined. Particles in the bundle are produced with process of the development of the nuclear cascade, the primary energy of each interaction in the cascade which produces these particles is unknown. To know the primary energy dependence of transverse momentum, the average products of energy and distance for various average energies of secondary particles are studied.

  2. Analysis of an Aircraft Honeycomb Sandwich Panel with Circular Face Sheet/Core Disbond Subjected to Ground-Air Pressurization

    NASA Technical Reports Server (NTRS)

    Rinker, Martin; Krueger, Ronald; Ratcliffe, James

    2013-01-01

    The ground-air pressurization of lightweight honeycomb sandwich structures caused by alternating pressure differences between the enclosed air within the honeycomb core and the ambient environment is a well-known and controllable loading condition of aerospace structures. However, initial face sheet/core disbonds intensify the face sheet peeling effect of the internal pressure load significantly and can decrease the reliability of the sandwich structure drastically. Within this paper, a numerical parameter study was carried out to investigate the criticality of initial disbonds in honeycomb sandwich structures under ground-air pressurization. A fracture mechanics approach was used to evaluate the loading at the disbond front. In this case, the strain energy release rate was computed via the Virtual Crack Closure Technique. Special attention was paid to the pressure-deformation coupling which can decrease the pressure load within the disbonded sandwich section significantly when the structure is highly deformed.

  3. Challenging Core Assumptions: Integrating Transformative Leadership Models into Campus-Wide Implementation Activities.

    ERIC Educational Resources Information Center

    Cramer, Sharon F.

    2003-01-01

    Examines three cycles of activities during the multi-year implementation of new student services software at a Masters I public comprehensive college with an enrollment of 12,000. Uses the theoretical framework of transformative leadership. Interpretations and recommendations address organizational issues that can be generalized beyond the…

  4. TRANSFORMER

    DOEpatents

    Baker, W.R.

    1959-08-25

    Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

  5. ZT-P: an advanced air core reversed field pinch prototype

    SciTech Connect

    Schoenberg, K.F.; Buchenauer, C.J.; Burkhardt, L.C.; Caudill, L.D.; Dike, R.S.; Dominguez, T.; Downing, J.N.; Forman, P.R.; Garcia, J.A.; Giger, A.J.

    1986-01-01

    The ZT-P experiment, with a major radius of 0.45 m and a minor radius of 0.07 m, was designed to prototype the next generation of reversed field pinch (RFP) machines at Los Alamos. ZT-P utilizes an air-core poloidal field system, with precisely wound and positioned rigid copper coils, to drive the plasma current and provide plasma equilibrium with intrinsically low magnetic field errors. ZT-P's compact configuration is adaptable to test various first wall and limiter designs at reactor-relevant current densities in the range of 5 to 20 MA/m/sup 2/. In addition, the load assembly design allows for the installation of toroidal field divertors. Design of ZT-P began in October 1983, and assembly was completed in October 1984. This report describes the magnetic, electrical, mechanical, vacuum, diagnostic, data acquisition, and control aspects of the machine design. In addition, preliminary data from initial ZT-P operation are presented. Because of ZT-P's prototypical function, many of its design aspects and experimental results are directly applicable to the design of a next generation RFP. 17 refs., 47 figs.

  6. Current limiting behavior in three-phase transformer-type SFCLs using an iron core according to variety of fault

    NASA Astrophysics Data System (ADS)

    Cho, Yong-Sun; Jung, Byung-Ik; Ha, Kyoung-Hun; Choi, Soo-Geun; Park, Hyoung-Min; Choi, Hyo-Sang

    To apply the superconducting fault current limiter (SFCL) to the power system, the reliability of the fault-current-limiting operation must be ensured in diverse fault conditions. The SFCL must also be linked to the operation of the high-speed recloser in the power system. In this study, a three-phase transformer-type SFCL, which has a neutral line to improve the simultaneous quench characteristics of superconducting elements, was manufactured to analyze the fault-current-limiting characteristic according to the single, double, and triple line-to-ground faults. The transformer-type SFCL, wherein three-phase windings are connected to one iron core, reduced the burden on the superconducting element as the superconducting element on the sound phase was also quenched in the case of the single line-to-ground fault. In the case of double or triple line-to-ground faults, the flux from the faulted phase winding was interlinked with other faulted or sound phase windings, and the fault-current-limiting rate decreased because the windings of three phases were inductively connected by one iron core.

  7. Transformation of a Ruptured Giant Pulmonary Artery Aneurysm into an Air Cavity After Transcatheter Embolization in a Behcet's Patient

    SciTech Connect

    Cil, Barbaros E. Turkbey, Baris; Canyigit, Murat; Kumbasar, Ozlem O.; Celik, Gokhan; Demirkazik, Figen B.

    2006-02-15

    Pulmonary artery aneurysms due to Behcet's disease are mainly seen in young males and very rarely in females. To our knowledge there are only 10 cases reported in the related literature. Emergent transcatheter embolization was performed in a female patient with a known history of Behcet's disease in whom massive hemoptysis developed because of rupture of a giant pulmonary artery aneurysm. At 6-month follow-up, transformation of the aneurysm sac into an air cavity was detected. To our knowledge, such a transformation has never been reported in the literature before. Embolization of the pulmonary artery aneurysm and the mechanism of cavity transformation are reviewed and discussed.

  8. Air and silica core Bragg fibers for radiation delivery in the wavelength range 0.6-1.5 μ m

    NASA Astrophysics Data System (ADS)

    Frank, Milan; Jelínek, Michal; Kubeček, Václav; Kašík, Ivan; Podrazký, Ondřej; Matějec, Vlastimil

    2016-09-01

    This paper presents fundamental characteristics of laboratory designed and fabricated Bragg fibers with air and silica cores at wavelengths of 632, 975, 1064 and 1550 nm. Fibers with the 26- μ m-silica core and 5- or 73- μ m-air cores in diameters and claddings of 3 pairs of Bragg layers were prepared from one preform. The overall transmittance, attenuation coefficients, coupling losses, bending losses, and damage-intensity thresholds were determined using four continuous-wave laser sources with the maximum output power of 300 mW and a pulsed 9 ns laser with the maximum output energy up to 1 mJ. The lowest attenuation coefficient of about 70 dB/km was determined at 1064 nm with the 73- μ m-air-core Bragg fiber. All fibers have been found to exhibit negligible bending losses down to the bending diameters of 5 cm. In comparison with the conventional gradient optical fiber, all the prepared Bragg fibers have approximately six times higher damage intensity threshold of about 30 GWcm-2 and therefore they are very suitable for high power laser radiation delivery.

  9. Importance of air bubbles in the core of coated pellets: Synchrotron X-ray microtomography allows for new insights.

    PubMed

    Fahier, J; Muschert, S; Fayard, B; Velghe, C; Byrne, G; Doucet, J; Siepmann, F; Siepmann, J

    2016-09-10

    High-resolution X-ray microtomography was used to get deeper insight into the underlying mass transport mechanisms controlling drug release from coated pellets. Sugar starter cores were layered with propranolol HCl and subsequently coated with Kollicoat SR, plasticized with 10% TEC. Importantly, synchrotron X-ray computed microtomography (SR-μCT) allowed direct, non-invasive monitoring of crack formation in the film coatings upon exposure to the release medium. Propranolol HCl, as well as very small sugar particles from the pellets' core, were expulsed through these cracks into the surrounding bulk fluid. Interestingly, SR-μCT also revealed the existence of numerous tiny, air-filled pores (varying in size and shape) in the pellet cores before exposure to the release medium. Upon water penetration into the system, the contents of the pellet cores became semi-solid/liquid. Consequently, the air-pockets became mobile and fused together. They steadily increased in size (and decreased in number). Importantly, "big" air bubbles were often located in close vicinity of a crack within the film coating. Thus, they play a potentially crucial role for the control of drug release from coated pellets. PMID:27374626

  10. Towards constraining the stratosphere-troposphere exchange of radiocarbon: strategies of stratospheric 14CO2 measurements using AirCore

    NASA Astrophysics Data System (ADS)

    Chen, Huilin; Paul, Dipayan; Meijer, Harro; Miller, John; Kivi, Rigel; Krol, Maarten

    2016-04-01

    Radiocarbon (14C) plays an important role in the carbon cycle studies to understand both natural and anthropogenic carbon fluxes, but also in atmospheric chemistry to constrain hydroxyl radical (OH) concentrations in the atmosphere. Apart from the enormous 14C emissions from nuclear bomb testing in the 1950s and 1960s, radiocarbon is primarily produced in the stratosphere due to the cosmogenic production. To this end, better understanding the stratospheric radiocarbon source is very useful to advance the use of radiocarbon for these applications. However, stratospheric 14C observations have been very limited so that there are large uncertainties on the magnitude and the location of the 14C production as well as the transport of radiocarbon from the stratosphere to the troposphere. Recently we have successfully made stratospheric 14C measurements using AirCore samples from Sodankylä, Northern Finland. AirCore is an innovative atmospheric sampling system, which passively collects atmospheric air samples into a long piece of coiled stainless steel tubing during the descent of a balloon flight. Due to the relatively low cost of the consumables, there is a potential to make such AirCore profiling in other parts of the world on a regular basis. In this study, we simulate the 14C in the atmosphere and assess the stratosphere-troposphere exchange of radiocarbon using the TM5 model. The Sodankylä radiocarbon measurements will be used to verify the performance of the model at high latitude. Besides this, we will also evaluate the influence of different cosmogenic 14C production scenarios and the uncertainties in the OH field on the seasonal cycles of radiocarbon and on the stratosphere-troposphere exchange, and based on the results design a strategy to set up a 14C measurement program using AirCore.

  11. A two-dimensional Stockwell transform for gravity wave analysis of AIRS measurements

    NASA Astrophysics Data System (ADS)

    Hindley, Neil P.; Smith, Nathan D.; Wright, Corwin J.; Rees, D. Andrew S.; Mitchell, Nicholas J.

    2016-06-01

    Gravity waves (GWs) play a crucial role in the dynamics of the earth's atmosphere. These waves couple lower, middle and upper atmospheric layers by transporting and depositing energy and momentum from their sources to great heights. The accurate parameterisation of GW momentum flux is of key importance to general circulation models but requires accurate measurement of GW properties, which has proved challenging. For more than a decade, the nadir-viewing Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite has made global, two-dimensional (2-D) measurements of stratospheric radiances in which GWs can be detected. However, one problem with current one-dimensional methods for GW analysis of these data is that they can introduce significant unwanted biases. Here, we present a new analysis method that resolves this problem. Our method uses a 2-D Stockwell transform (2DST) to measure GW amplitudes, horizontal wavelengths and directions of propagation using both the along-track and cross-track dimensions simultaneously. We first test our new method and demonstrate that it can accurately measure GW properties in a specified wave field. We then show that by using a new elliptical spectral window in the 2DST, in place of the traditional Gaussian, we can dramatically improve the recovery of wave amplitude over the standard approach. We then use our improved method to measure GW properties and momentum fluxes in AIRS measurements over two regions known to be intense hotspots of GW activity: (i) the Drake Passage/Antarctic Peninsula and (ii) the isolated mountainous island of South Georgia. The significance of our new 2DST method is that it provides more accurate, unbiased and better localised measurements of key GW properties compared to most current methods. The added flexibility offered by the scaling parameter and our new spectral window presented here extend the usefulness of our 2DST method to other areas of geophysical data analysis and beyond.

  12. Source Attribution of Toronto Regional Air Pollution Measured with Fourier Transform Spectroscopy

    NASA Astrophysics Data System (ADS)

    Whaley, C.; Strong, K.; Jones, D. B.; Fast, H.; Fogal, P. F.; McLinden, C. A.; Mittermeier, R. L.; Pommier, M.

    2013-12-01

    Toronto is the centre of Canada's largest population and is often downwind of the industrial midwestern United States, where there is an even larger population and significant anthropogenic emissions. As a result, surface O3 in the region often exceeds the Canada-Wide Standard and the provincial Ambient Air Quality Criterion. Therefore, the Toronto region makes for an interesting North-American site to study atmospheric composition. There have been ground-based, solar-absorption Fourier transform infrared (FTIR) spectroscopic measurements of tropospheric (0-5 km) O3 and CO columns (among other species) for over a decade at the Univerisity of Toronto Atmospheric Observatory (TAO, 43.66oN, 79.40oW, 174 masl) and Environment Canada's Centre for Atmospheric Research Experiments (CARE, 44.23oN, 79.78oW, 251 masl). In combination with surface measurements of these species from the Ontario Ministry of the Environment and Environment Canada, and satellite overpasses of the Measurements of Pollution in the Troposphere (MOPITT) instrument, we have a large number of tropospheric O3 and CO observations in both downtown Toronto and the surrounding rural area from 2002 to the present. Using these datasets, we have examined pollution events in Toronto characterized by enhanced O3 and/or CO tropospheric columns, and we have conducted source attribution analyses using the GEOS-Chem chemical transport model and its adjoint. We will present several case studies, in which we quantify the relative contribution of biomass burning, anthropogenic emissions, and biogenic emissions to Toronto-area pollution events. We will discuss the conditions for which the tropospheric columns are well-correlated to the surface measurements, and when they are not. We will also present statistics on nine years of data (2002 to 2010), to better understand when and how the Toronto-area O3 and CO enhancements occur, which will be useful for future air quality policies.

  13. Artificial neural networks forecasting of PM2.5 pollution using air mass trajectory based geographic model and wavelet transformation

    NASA Astrophysics Data System (ADS)

    Feng, Xiao; Li, Qi; Zhu, Yajie; Hou, Junxiong; Jin, Lingyan; Wang, Jingjie

    2015-04-01

    In the paper a novel hybrid model combining air mass trajectory analysis and wavelet transformation to improve the artificial neural network (ANN) forecast accuracy of daily average concentrations of PM2.5 two days in advance is presented. The model was developed from 13 different air pollution monitoring stations in Beijing, Tianjin, and Hebei province (Jing-Jin-Ji area). The air mass trajectory was used to recognize distinct corridors for transport of "dirty" air and "clean" air to selected stations. With each corridor, a triangular station net was constructed based on air mass trajectories and the distances between neighboring sites. Wind speed and direction were also considered as parameters in calculating this trajectory based air pollution indicator value. Moreover, the original time series of PM2.5 concentration was decomposed by wavelet transformation into a few sub-series with lower variability. The prediction strategy applied to each of them and then summed up the individual prediction results. Daily meteorological forecast variables as well as the respective pollutant predictors were used as input to a multi-layer perceptron (MLP) type of back-propagation neural network. The experimental verification of the proposed model was conducted over a period of more than one year (between September 2013 and October 2014). It is found that the trajectory based geographic model and wavelet transformation can be effective tools to improve the PM2.5 forecasting accuracy. The root mean squared error (RMSE) of the hybrid model can be reduced, on the average, by up to 40 percent. Particularly, the high PM2.5 days are almost anticipated by using wavelet decomposition and the detection rate (DR) for a given alert threshold of hybrid model can reach 90% on average. This approach shows the potential to be applied in other countries' air quality forecasting systems.

  14. Metglas 2714A for Low Temperature Transformer Core and EMI Filter

    NASA Technical Reports Server (NTRS)

    Quach, Hung; Chui, Talso

    2003-01-01

    We have measured the real and imaginary parts of the relative permeability of Metglas 2714A. The magnetization noise density of a toroid made of this material is also measured with a SQUID magnetometer. This noise density is found to agree very well with the fluctuation dissipation theorem, implying that superconducting transformers with predictable noise characteristic can be designed. We also find that the relative permeability is larger than 10,000 at liquid helium temperature and at frequencies from DC to 100 kHz, making it suitable to be used as EMI filter material. Its usage should be similar to that of ferrites, with the exception that it is also effective at low temperatures.

  15. Fabrication of a polyvinylidene difluoride fiber with a metal core and its application as directional air flow sensor

    NASA Astrophysics Data System (ADS)

    Bian, Yixiang; Liu, Rongrong; Hui, Shen

    2016-09-01

    We fabricated a sensitive air flow detector that mimic the sensing mechanism found at the tail of some insects. [see Y. Yang, A. Klein, H. Bleckmann and C. Liu, Appl. Phys. Lett. 99(2) (2011); J. J. Heys, T. Gedeon, B. C. Knott and Y. Kim, J. Biomech. 41(5), 977 (2008); J. Tao and X. Yu, Smart Mat. Struct. 21(11) (2012)]. Our bionic airflow sensor uses a polyvinylidene difluoride (PVDF) microfiber with a molybdenum core which we produced with the hot extrusion tensile method. The surface of the fiber is partially coated with conductive silver adhesive that serve as surface electrodes. A third electrode, the metal core is used to polarize polyvinylidene difluoride (PVDF) under the surface electrodes. The cantilever beam structure of the prepared symmetric electrodes of metal core piezoelectric fiber (SMPF) is used as the artificial hair airflow sensor. The surface electrodes are used to measure output voltage. Our theoretical and experimental results show that the SMPF responds fast to air flow changes, the output charge has an exponential correlation with airflow velocity and a cosine relation with the direction of airflow. Our bionic airflow sensor with directional sensing ability can also measure air flow amplitude. [see H. Droogendijk, R. G. P. Sanders and G. J. M. Krijnen, New J. Phys. 15 (2013)]. By using two surface electrodes, our sensing circuit further improves sensitivity.

  16. Cusp-core transformations induced by AGN feedback in the progenitors of cluster galaxies

    NASA Astrophysics Data System (ADS)

    Martizzi, Davide; Teyssier, Romain; Moore, Ben

    2013-07-01

    In a recent study, we used cosmological simulations to show that active galactic nuclei (AGN) feedback on the gas distribution in clusters of galaxies can be important in determining the spatial distribution of stars and dark matter in the central regions of these systems. The hierarchical assembly of dark matter, baryons and black holes obscures the physical mechanism behind the restructuring process. Here, we use idealized simulations to follow the response of a massive dark matter halo as we feed the central black hole with a controlled supply of cold gas. This removes most of the complexity taking place in the cosmological simulations that may have biased our previous study. We confirm our previous results: gas heated and expelled from the central regions of the halo by AGN feedback can return after cooling; repeated cycles generate gravitational potential fluctuations responsible for irreversible modifications of the dark matter mass profile. The main result is the expulsion of large amounts of baryons and dark matter from the central regions of the halo. According to the work presented here, outflow-induced fluctuations represent the only mechanism able to efficiently create dark matter cores in clusters of galaxies.

  17. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  18. Habitable evaporated cores: transforming mini-Neptunes into super-Earths in the habitable zones of M dwarfs.

    PubMed

    Luger, R; Barnes, R; Lopez, E; Fortney, J; Jackson, B; Meadows, V

    2015-01-01

    We show that photoevaporation of small gaseous exoplanets ("mini-Neptunes") in the habitable zones of M dwarfs can remove several Earth masses of hydrogen and helium from these planets and transform them into potentially habitable worlds. We couple X-ray/extreme ultraviolet (XUV)-driven escape, thermal evolution, tidal evolution, and orbital migration to explore the types of systems that may harbor such "habitable evaporated cores" (HECs). We find that HECs are most likely to form from planets with ∼1 M⊕ solid cores with up to about 50% H/He by mass, though whether or not a given mini-Neptune forms a HEC is highly dependent on the early XUV evolution of the host star. As terrestrial planet formation around M dwarfs by accumulation of local material is likely to form planets that are small and dry, evaporation of small migrating mini-Neptunes could be one of the dominant formation mechanisms for volatile-rich Earths around these stars. PMID:25590532

  19. Centimeter-scale secondary information on hydraulic conductivity using a hand-held air permeameter on borehole cores.

    NASA Astrophysics Data System (ADS)

    Rogiers, B.; Winters, P.; Huysmans, M.; Beerten, K.; Mallants, D.; Gedeon, M.; Batelaan, O.; Dassargues, A.

    2012-04-01

    Saturated hydraulic conductivity (Ks) is one of the most important parameters determining groundwater flow and contaminant transport in both unsaturated and saturated porous media. Determining the small-scale variability of this parameter is key to evaluate implications on effective parameters at the larger scale. Moreover, for stochastic simulations of groundwater flow and contaminant transport, accurate models on the spatial variability of Ks are very much needed. While several well-established laboratory methods exist for determining Ks, investigating the small-scale variability remains a challenge. If several tens to hundreds of metres of borehole core has to be hydraulically characterised at the centimetre to decimetre scale, several hundreds to thousands of Ks measurements are required, which makes it very costly and time-consuming should traditional methods be used. With reliable air permeameters becoming increasingly available from the late 80's, a fast and effective indirect method exists to determine Ks. Therefore, the use of hand-held air permeameter measurements for determining very accurate small-scale heterogeneity about Ks is very appealing. Very little is known, however, on its applicability for borehole cores that typically carry a small sediment volume. Therefore, the method was tested on several borehole cores of different size, originating from the Campine basin, Northern Belgium. The studied sediments are of Miocene to Pleistocene age, with a marine to continental origin, and consist of sand to clayey sand with distinct clay lenses, resulting in a Ks range of 7 orders of magnitude. During previous studies, two samples were taken from borehole cores each two meters for performing constant head lab permeameter tests. This data is now used as a reference for the air permeameter measurements that are performed with a resolution of 5 centimetres. Preliminary results indicate a very good correlation between the previously gathered constant head Ks

  20. 'Core species' in three sources of indoor air belonging to the human micro-environment to the exclusion of outdoor air.

    PubMed

    Gaüzère, Carole; Godon, Jean-Jacques; Blanquart, Hélène; Ferreira, Stéphanie; Moularat, Stéphane; Robine, Enric; Moletta-Denat, Marina

    2014-07-01

    Although we spend the majority of our lives indoors, the airborne microbial content of enclosed spaces still remains inadequately described. The objective of this study was to characterize the bacterial diversity of indoor air in three different enclosed spaces with three levels of occupancy, and, in particular, to highlight the 'core' species, the opportunistic pathogens and their origins. Our findings provide an overall description of bacterial diversity in these indoor environments. Data gathered from the three enclosed spaces revealed the presence of a common indoor signature (60% of total sequences in common). This work will provide a clearer understanding of the dominant groups of bacteria encountered in enclosed spaces: Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes. Thus, certain evidence revealed a connection between 'core' species and the human micro-environment (20% of phylotypes and 12% of sequences of human origin). Overall PCA analysis showed that the indoor environment is influenced mainly by the microbial diversity from nose and skin. Among the 'core species' found during this study, a large number (72% of all pathogen-related sequences were concentrated in 'core species') of genera and species are known to be responsible for opportunistic or nosocomial diseases or to include human commensal bacteria such as Mycobacterium sp., Acinetobacter baumanii, Aerococcus viridians, Thermoactinomyces vulgaris or Clostridium perfringens. PMID:24747243

  1. Heat-induced transformation of CdSe-CdS-ZnS core-multishell quantum dots by Zn diffusion into inner layers.

    PubMed

    Yalcin, Anil O; Goris, Bart; van Dijk-Moes, Relinde J A; Fan, Zhaochuan; Erdamar, Ahmet K; Tichelaar, Frans D; Vlugt, Thijs J H; Van Tendeloo, Gustaaf; Bals, Sara; Vanmaekelbergh, Daniël; Zandbergen, Henny W; van Huis, Marijn A

    2015-02-25

    In this work, we investigate the thermal evolution of CdSe-CdS-ZnS core-multishell quantum dots (QDs) in situ using transmission electron microscopy (TEM). Starting at a temperature of approximately 250 °C, Zn diffusion into inner layers takes place together with simultaneous evaporation of particularly Cd and S. As a result of this transformation, CdxZn1-xSe-CdyZn1-yS core-shell QDs are obtained. PMID:25431813

  2. Effects of incubation in an atmosphere of 20% CO2 in air on the Syrian hamster embryo clonal transformation assay.

    PubMed

    Przygoda, R T; Takayama, K; Traul, K A; Tummey, A

    1985-01-01

    An atmosphere containing 10% CO2 has been generally accepted as optimal for the growth of Syrian hamster embryo cells in a clonal transformation assay. Data presented in this paper show that 10% CO2 may not be the optimum environment for this assay. Using 10 or 20% (analytically measured) CO2 in air (1 atm pressure), hamster embryo cell pools were examined for clonal growth characteristics and transformability using five known carcinogens and a single noncarcinogenic compound. At 10% CO2, only 2 of 11 pools were transformed by the five carcinogens but not by the noncarcinogen. At 20% CO2, six of seven pools were transformed by the five carcinogens and not by the noncarcinogen. Further, the transformation frequencies were found to be greater in cultures incubated in an atmosphere consisting of 20% CO2 in air. The data also show that 20% CO2 increased the cloning efficiency of these cells. A comparison of the 10 and 20% CO2 data to results reported from other laboratories suggests that conflicting interlaboratory results with this assay system may be due, in part, to variations of CO2 concentrations. In some instances, the CO2 levels indicated by incubator flow meters vary considerably from analytically determined CO2 values. To prevent these CO2 discrepancies and their resultant effects on transformation and cloning efficiency, methods for monitoring the CO2 environment other than flow meters are recommended. The observation of increased cloning efficiencies and transformation rates strongly suggests that culture incubation at 20% CO2 is a preferred environment for the conduct of this assay. PMID:3936836

  3. Evaluation of dust-related health hazards associated with air coring at G-Tunnel, Nevada Test Site

    SciTech Connect

    Skaggs, B.J.; Ortiz, L.W.; Burton, D.J.; Isom, B.L.; Vigil, E.A.

    1991-03-01

    The Yucca Mountain Project was established to evaluate the potential for storing high-level radioactive wastes in geologic formations. Hydrologists recommended that drilling or coring in support of characterization tests be performed dry. Dry drilling, or air coring, presents a concern about health protection for the drilling personnel. The rock generally has a high silica content, and natural zeolites are abundant. Some zeolites are fibrous, leading to concerns that inhalation may result in asbestos-like lung diseases. An industrial hygiene study (IH) was conducted as part of an air coring technical feasibility test. The IH study found the potential for exposures to airborne silica and nuisance dusts to be within regulatory requirements and determined the commercial dust control equipment monitored to be effective when used in conjunction with a good area ventilation system and sound IH practices. Fibrous zeolites were not detected. Recommendations for the Yucca Mountain studies are (1) dust collection and control equipment equivalent or superior to that monitored must be used for any dry drilling activity and must be used with good general dilution ventilation and local exhaust ventilation provided on major emission sources; (2) good industrial hygiene work practices must be implemented, including monitoring any area where zeolitic fibers are suspect; and (3) a study should be conducted to determine the biological effects of the fibrous zeolite, mordenite. 25 refs., 17 figs., 14 tabs.

  4. Highly active and durable core-corona structured bifunctional catalyst for rechargeable metal-air battery application.

    PubMed

    Chen, Zhu; Yu, Aiping; Higgins, Drew; Li, Hui; Wang, Haijiang; Chen, Zhongwei

    2012-04-11

    A new class of core-corona structured bifunctional catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal-air battery application. The nanostructured design of the catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO(3)) and carbon-supported platinum (Pt/C), with added bifunctional capabilities allowing metal-air battery rechargeability. LaNiO(3) and Pt/C are currently the most accepted benchmark electrocatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive catalyst component for the cathode of rechargeable metal-air batteries. Moreover, after full-range degradation testing (FDT) CCBC retained excellent activity, retaining 3 and 13 times greater ORR and OER current upon comparison to state of the art Pt/C. Zinc-air battery performances of CCBC is in good agreement with the half-cell experiments with this bifunctional electrocatalyst displaying high activity and stability during battery discharge, charge, and cycling processes. Owing to its outstanding performance toward both the OER and ORR, comparable with the highest performing commercial catalysts to date for each of the respective reaction, coupled with high stability and rechargeability, CCBC is presented as a novel class of bifunctional catalyst material that is very applicable to future generation rechargeable metal-air batteries. PMID:22372510

  5. Air content and O2/N2 tuned chronologies on local insolation signatures in the Vostok ice core are similar

    NASA Astrophysics Data System (ADS)

    Lipenkov, V.; Raynaud, D.; Loutre, M.-F.; Duval, P.; Lemieux-Dudon, B.

    2009-04-01

    An accurate chronology of ice cores is needed for interpreting the paleoclimatic record and understanding the relation between insolation and climate. A new domain of research in this area has been initially stimulated by the work of M. Bender (2002) linking the record of O2/N2 ratio in the air trapped in the Vostok ice with the local insolation. More recently, it has been proposed that the long-term changes in air content, V, recorded in ice from the high Antarctic plateau is also dominantly imprinted by the local summer insolation (Raynaud et al., 2007). The present paper presents a new V record from Vostok, which is compared with the published Vostok O2/N2 record for the same period of time (150-400 ka BP) by using the same spectral analysis methods. The spectral differences between the two properties and the possible mechanisms linking them with insolation through the surface snow structure and the close-off processes are discussed. The main result of our study is that the two experimentally independent local insolation proxies lead to absolute (orbital) time scales, which agree together within a standard deviation of 0.6 ka. This result strongly adds credibility to the air content of ice and the O2 to N2 ratio of the air trapped in ice as equally reliable and complementary tools for accurate dating of existing and future deep ice cores. References: M. Bender, Orbital tuning chronology for the Vostok climate record supported by trapped gas composition, Earth and Planetary Science Letters 204(2002) 275-289. D. Raynaud, V. Lipenkov, B. Lemieux-Dudon, P. Duval, M.F. Loutre, N. Lhomme, The local insolation signature of air content in Antarctic ice: a new step toward an absolute dating of ice records, Earth and Planetary Science Letters 261(2007) 337-349.

  6. APPLICATION OF FOURIER TRANSFORM SPECTROSCOPY TO AIR POLLUTION PROBLEMS. COMPUTER-GENERATED LONG-PATH AIR SPECTRA

    EPA Science Inventory

    An atlas of computer-generated infrared transmission spectra of the atmosphere for low humidity (29 percent relative humidity) and high humidity (65 percent relative humidity) air samples is presented. These spectra extend from 700/cm to 3000/cm, and were computed with a resoluti...

  7. Climatic and insolation control on the high-resolution total air content in the NGRIP ice core

    NASA Astrophysics Data System (ADS)

    Eicher, O.; Baumgartner, M.; Schilt, A.; Schmitt, J.; Schwander, J.; Stocker, T. F.; Fischer, H.

    2015-11-01

    Because the total air content (TAC) of polar ice is directly affected by the atmospheric pressure, its record in polar ice cores was considered as a proxy for past ice sheet elevation changes. However the Antarctic ice core TAC record is known to also contain an insolation signature, although the underlying physical mechanisms are still a matter of debate. Here we present a high-resolution TAC record over the whole North Greenland Ice Core Project ice core, covering the last 120 000 years, which independently supports an insolation signature in Greenland. Wavelet analysis reveals a clear precession and obliquity signal similar to previous findings on Antarctic TAC, with different insolation history. In our high-resolution record we also find a decrease of 3-5 % (3-4.2 mL kg-1) in TAC as a response to Dansgaard-Oeschger-Events (DO-events). TAC starts to decrease in parallel to increasing Greenland surface temperature and slightly before CH4 reacts to the warming, but also shows a two-step decline that lasts for several centuries into the warm phase/interstadial. The TAC response is larger than expected considering only local temperature and atmospheric pressure as a driver, pointing to transient firnification response caused by the accumulation-induced increase in the load on the firn at bubble close-off, while temperature changes deeper in the firn are still small.

  8. The Fourier transform spectrometer of the Université Pierre et Marie Curie QualAir platform.

    PubMed

    Té, Y; Jeseck, P; Payan, S; Pépin, I; Camy-Peyret, C

    2010-10-01

    A Bruker Optics IFS 125HR Fourier transform spectrometer (FTS) and the Laboratoire de Physique Moléculaire pour l'Atmosphère et l'Astrophysique retrieval algorithm were adapted for ground based atmospheric measurements. As one of the major instruments of the experimental research platform QualAir, this FTS is dedicated to study the urban air composition of large megacity such as Paris. The precise concentration measurements of the most important atmospheric pollutants are a key to improve the understanding and modeling of urban air pollution processes. Located in the center of Paris, this remote sensing spectrometer enables to monitor many pollutants. Examples for NO(2) and CO are demonstrating the performances of this new experimental setup. PMID:21034070

  9. A Panchromatic Imaging Fourier Transform Spectrometer for the NASA Geostationary Coastal and Air Pollution Events Mission

    NASA Technical Reports Server (NTRS)

    Wu, Yen-Hung; Key, Richard; Sander, Stanley; Blavier, Jean-Francois; Rider, David

    2011-01-01

    This paper summarizes the design and development of the Panchromatic Imaging Fourier Transform Spectrometer (PanFTS) for the NASA Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission. The PanFTS instrument will advance the understanding of the global climate and atmospheric chemistry by measuring spectrally resolved outgoing thermal and reflected solar radiation. With continuous spectral coverage from the near-ultraviolet through the thermal infrared, this instrument is designed to measure pollutants, greenhouse gases, and aerosols as called for by the U.S. National Research Council Decadal Survey; Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond1. The PanFTS instrument is a hybrid instrument based on spectrometers like the Tropospheric Emissions Spectrometer (TES) that measures thermal emission, and those like the Orbiting Carbon Observatory (OCO), and the Ozone Monitoring Instrument (OMI) that measure scattered solar radiation. Simultaneous measurements over the broad spectral range from IR to UV is accomplished by a two sided interferometer with separate optical trains and detectors for the ultraviolet-visible and infrared spectral domains. This allows each side of the instrument to be independently optimized for its respective spectral domain. The overall interferometer design is compact because the two sides share a single high precision cryogenic optical path difference mechanism (OPDM) and metrology laser as well as a number of other instrument systems including the line-of-sight pointing mirror, the data management system, thermal control system, electrical system, and the mechanical structure. The PanFTS breadboard instrument has been tested in the laboratory and demonstrated the basic functionality for simultaneous measurements in the visible and infrared. It is set to begin operations in the field at the California Laboratory for Atmospheric Remote Sensing (CLARS) observatory on Mt. Wilson

  10. A Panchromatic Imaging Fourier Transform Spectrometer for the NASA Geostationary Coastal and Air Pollution Events Mission

    NASA Astrophysics Data System (ADS)

    Wu, Yen-Hung; Key, Richard; Sander, Stanley; Blavier, Jean-Francois; Rider, David

    2011-10-01

    This paper summarizes the design and development of the Panchromatic Imaging Fourier Transform Spectrometer (PanFTS) for the NASA Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission. The PanFTS instrument will advance the understanding of the global climate and atmospheric chemistry by measuring spectrally resolved outgoing thermal and reflected solar radiation. With continuous spectral coverage from the near-ultraviolet through the thermal infrared, this instrument is designed to measure pollutants, greenhouse gases, and aerosols as called for by the U.S. National Research Council Decadal Survey; Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond1. The PanFTS instrument is a hybrid based on spectrometers like the Tropospheric Emissions Spectrometer (TES) that measures thermal emission, and those like the Orbiting Carbon Observatory (OCO), and the Ozone Monitoring Instrument (OMI) that measure scattered solar radiation. Simultaneous measurements over the broad spectral range from IR to UV is accomplished by a two sided interferometer with separate optical trains and detectors for the UV-visible and IR spectral domains. This allows each side of the instrument to be independently optimized for its respective spectral domain. The overall interferometer design is compact because the two sides share a single high precision cryogenic optical path difference mechanism (OPDM) and metrology laser as well as a number of other instrument systems including the line-of-sight pointing mirror, the data management system, thermal control system, electrical system, and the mechanical structure. The PanFTS breadboard instrument has been tested in the laboratory and demonstrated the basic functionality for simultaneous measurements in the visible and IR. It is set to begin operations in the field at the California Laboratory for Atmospheric Remote Sensing (CLARS) observatory on Mt. Wilson measuring the atmospheric chemistry

  11. Design and fabrication of a metal core PVDF fiber for an air flow sensor

    NASA Astrophysics Data System (ADS)

    Bian, Yixiang; Liu, Rongrong; Huang, Xiaomei; Hong, Jin; Huang, Huiyu; Hui, Shen

    2015-10-01

    To track prey or avoid predators, many arthropods can detect variations in airflow and pressure gradients using an array of very thin and sensitive filiform hairs. In this study, metal core piezoelectric poly(vinylidene fluoride) (PVDF) fibers were prepared to mimic such hair sensors. The flexibility of the fibers was very good, which was helpful for overcoming the typical brittleness of piezoelectric ceramic fibers. At the same time, the diameter of the fibers was very small (down to 50 μm in diameter). In order to mimic the insects’ hairs to the maximum extent, which was expected to greatly improve the sensitivity of such PVDF fiber-based sensors, a feasible process to prepare and extract electrodes on the surface of the fibers had to be developed. Compared with stainless steel filament-core fibers, the molybdenum filament-core PVDF fibers were easy to stretch. The molybdenum filament was then covered by a cylindrical PVDF layer with a diameter of 400 μm. One half of the longitudinal surface of the fibers was spray-coated with a conductive silver adhesive. The metal core was then used as one electrode, and the conductive silver adhesive was used as the other electrode. After polarization, a single metal-core PVDF fiber could be used as an airflow sensor. The surface structure and the sections of the PVDF fiber were analyzed by scanning electron microscopy. The results of the mechanical stretching tests showed that the metal core greatly enhanced the mechanical properties of the PVDF fibers. X-ray diffraction revealed that the greater the stretching ratio, the higher the α-to-β-phase conversion rate during the preparation of the PVDF fibers. A single metal-core PVDF fiber was used as a bionic airflow sensor, and a mechanical model of this sensor was derived. The airflow sensing capability of the PVDF fiber was experimentally confirmed in a miniature wind tunnel. The results showed that a cantilevered metal-core PVDF fiber is capable of detecting the range

  12. Composite Cores

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

  13. Activation energies for phase transformations in electrospun titania nanofibers: comparing the influence of argon and air atmospheres

    NASA Astrophysics Data System (ADS)

    Albetran, H.; O'Connor, B. H.; Low, I. M.

    2016-04-01

    This paper reports on titania absolute phase level (amorphous, anatase, and rutile forms) changes in electrospun amorphous titania nanofibers from 25 to 900 °C in air and argon atmospheres. A novel method was developed to extract absolute levels of amorphous titania and crystalline anatase and rutile from the synchrotron radiation diffraction (SRD) data. This is a sequel to a relative phase concentrations study that has been reported previously by Albetran et al. (Appl Phys A 116:161 [2014]). Determination of absolute phase levels facilitated estimation of the activation energies for the amorphous-to-anatase transformation of 45(9) kJ/mol in argon and 69(17) in air, and for the anatase-to-rutile transformation energies of 97(7) kJ/mol for argon and 129(5) for air. An activation energy estimate for amorphous-to-crystalline titania in argon of 142(21) kJ/mol, achieved using differential scanning calorimetry (DSC), is consistent with the SRD results. The differences in phase transition and activation energies when the titania nanofibers are heated in argon is attributed to the presence of substantial oxygen vacancies in anatase. Estimates of anatase and rutile oxygen site occupancies from the SRD data show that anatase has discernible oxygen vacancies in argon, which correspond to stoichiometric TiO2- x with x < 0.4 that the anatase stoichiometry in air is TiO2. Rutile does not have significant oxygen vacancies in either argon or air.

  14. Transformer design tradeoffs

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1977-01-01

    Technical memorandum includes transformer area product numbers, which are used to summarize dimensional and electrical properties of C-cores, pot cores, lamination, powder cores, and tape-wound cores. To aid in core selection, comparison of five common core materials is presented to indicate their influence on overall transformer efficiency and weight.

  15. The bright-side and the dark-side of CEO personality: examining core self-evaluations, narcissism, transformational leadership, and strategic influence.

    PubMed

    Resick, Christian J; Whitman, Daniel S; Weingarden, Steven M; Hiller, Nathan J

    2009-11-01

    This article reports on an examination of the relationships between chief executive officer (CEO) personality, transformational and transactional leadership, and multiple strategic outcomes in a sample of 75 CEOs of Major League Baseball organizations over a 100-year period. CEO bright-side personality characteristics (core self-evaluations) were positively related to transformational leadership, whereas dark-side personality characteristics (narcissism) of CEOs were negatively related to contingent reward leadership. In turn, CEO transformational and contingent reward leadership were related to 4 different strategic outcomes, including manager turnover, team winning percentage, fan attendance, and an independent rating of influence. CEO transformational leadership was positively related to ratings of influence, team winning percentage, and fan attendance, whereas contingent reward leadership was negatively related to manager turnover and ratings of influence. PMID:19916649

  16. AirCore-HR: A high-resolution column measurement to enhance the knowledge on the vertical distribution of CO2 and CH4

    NASA Astrophysics Data System (ADS)

    Membrive, Olivier; Crevoisier, Cyril; Danis, François; Hertzog, Albert; Sweeney, Colm; Picon, Laurence; Durry, Georges; Amarouche, Nadir; Engel, Andreas; Boenisch, Harald

    2015-04-01

    The AirCore-HR (high-resolution) instrument is a simple and innovative atmospheric sampling system inspired from the NOAA AirCore (Karion et al. 2010). It consists of a 300m long coiled stainless steel tube (200m 1/8 in. and 100m 1/4 in. linked together as one). AirCore-HR allows balloon measurements of GHG vertical profiles (CO2 & CH4) from the surface up to approximately 30 km. It has been developed at LMD in partnership with NOAA and differs from other AirCores by its high vertical resolution: 100m at the surface up to 200m at 8km, then 100m at 8km up to 1 km at 30 km. AirCores rely on positive changes in ambient pressure for passive sampling of the atmosphere and are flown open at one end and closed at the other. The AirCore-HR closes at landing and the sample is measured with a continuous analyser for trace gas mole fraction. Our instrument was flown for the first time during the stratospheric balloon campaign operated by the French space agency CNES in Timmins (Ontario, Canada) in August 2014 on the "EdS-Stratéole" flight. The multi-instrument Gondola of this flight carried several instruments, including two others that measured CO2 & CH4 in situ: the Pico-SDLA (based on laser spectrometry) from GSMA, University of Reims & INSU Division Technique and two other AirCores with lower vertical resolution from Frankfurt University. The simultaneous flight of these instruments under the same balloon allows for direct comparison between the different measurements of mixing ratio profiles. We compare profiles from the AirCore-HR and in situ measurements. Moreover, AirCores provide extremely innovative means of observation that will provide a priori knowledge on the variations of methane and carbon dioxide for spaceborne total column measurements or model simulations. Here, we show the usefulness of the high vertical resolution in the upper troposphere and stratosphere for interpreting observations of total and partial column of methane and carbon dioxide from current

  17. Transformed X-48C Takes to the Air on First Flight - Duration: 109 seconds.

    NASA Video Gallery

    The remotely operated X-48C Blended Wing Body aircraft lifts off Rogers Dry Lake at Edwards Air Force Base, Calif., on its first test flight Aug. 7, 2012. The sub-scale technology demonstrator, mod...

  18. Accurate age scale of the Dome Fuji ice core, Antarctica from O2/N2 ratio of trapped air

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Aoki, S.; Nakazawa, T.; Suzuki, K.; Parrenin, F.

    2012-04-01

    Chronology of the first Dome Fuji deep ice core (core length: 2,500 m, ice thickness: 3,035 m) for the age range from 80 kyr to 340 kyr ago was established by orbital tuning of measured O2/N2 ratios in trapped air to local summer insolation, with precision better than about 2,000 years (Kawamura et al., 2007). The O2/N2 ratios found in polar ice cores are slightly lower than the atmospheric ratio because of size-dependent molecular fractionation during bubble close-off. The magnitude of this gas fractionation is believed to be governed by the magnitude of snow metamorphism when the layer was originally at the surface, which in turn is controlled by local summer insolation (Fujita et al., 2009). A strong advantage of the O2/N2 chronology is that there is no need to assume a lag between climatic records in the ice core and orbital forcings, becacuse O2/N2 ratios record local insolation through physical processes. Accuracy of the chronology was validated by comparing the O2/N2 chronology with U-Th radiometric chronology of speleothem records (Cheng et al., 2009) for the ends of Terminations II, III and IV, as well as several large climatic events, for which both ice-core CH4 and speleothem δ18O (a proxy for precipitation) show abrupt shifts as seen in the last glacial period. All ages from O2/N2 and U-Th chronology agreed with each other within ~2,000 yr. The O2/N2 chronology permits comparisons between Antarctic climate, greenhouse gases, astronomically calculated orbital parameters, and radiometrically-dated sea level and monsoon records. Here, we completed the measurements of O2/N2 ratios of the second Dome Fuji ice core, which reached bedrock, for the range from 2,400 to 3,028 m (320 - 700 kyr ago) at approximately 2,000-year time resolution. We made significant improvements in ice core storage practices and mass spectrometry. In particular, the ice core samples were stored at about -50 ° C until the air extraction, except during short periods of transportation

  19. Development of 600 kV triple resonance pulse transformer.

    PubMed

    Li, Mingjia; Zhang, Faqiang; Liang, Chuan; Xu, Zhou

    2015-06-01

    In this paper, a triple-resonance pulse transformer based on an air-core transformer is introduced. The voltage across the high-voltage winding of the air-core transformer is significantly less than the output voltage; instead, the full output voltage appears across the tuning inductor. The maximum ratio of peak load voltage to peak transformer voltage is 2.77 in theory. By analyzing pulse transformer's lossless circuit, the analytical expression for the output voltage and the characteristic equation of the triple-resonance circuit are presented. Design method for the triple-resonance pulse transformer (iterated simulation method) is presented, and a triple-resonance pulse transformer is developed based on the existing air-core transformer. The experimental results indicate that the maximum ratio of peak voltage across the load to peak voltage across the high-voltage winding of the air-core transformer is approximately 2.0 and the peak output voltage of the triple-resonance pulse transformer is approximately 600 kV. PMID:26133858

  20. The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L.; Kroutil, R.T.

    1992-07-01

    The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses.

  1. The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L. ); Kroutil, R.T. )

    1992-01-01

    The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses.

  2. The Transformational Power of Strategic Planning. AIR 2001 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Krotseng, Marsha V.; Zaccari, Ronald M.

    Strategic planning is vital to the effective management of colleges and universities. It is also integral to institutional change. This case study demonstrates the critical connection between strategic planning and institutional transformation by tracing the strategic planning process for a public baccalaureate institution over a 5-year period.…

  3. Interactions of Chemistry and Meteorology: Transforming Air Pollution into Climate Change

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.

    2009-05-01

    PThe common goal of understanding and protecting Earth's environment has brought together chemists and meteorologists, despite the once widely held view that these are natural adversaries. Historically, dynamics, physics, chemistry, and biology were explored as isolated aspects of air quality and climate, but nature has proved to be much more interesting than that. Emissions and atmospheric photochemistry create air pollutants, but meteorology drives day to day variability in air quality. Air pollution, no matter how severe, has no substantive impact on global atmospheric composition or climate unless it is transported away from the sources, usually through frontal passage and advection, isentropic lifting or, especially lofting in deep convective clouds and thunderstorms. At higher altitudes, greater actinic flux accelerates photochemistry, stronger winds speed dispersal, and lower temperatures slow losses while amplifying radiative heating of greenhouse forcing substance such as ozone and carbonaceous aerosols. Examples include the transport of reactive nitrogen compounds from one part of North America to another, or on to the remote North Atlantic and Europe. Although measurement of NOy and NHx gases and particles still presents an analytical challenge, these trace species have major impacts on ecosystems and biogeochemical cycles. In East Asia chemistry and meteorology conspire to intensify long-range, even intercontinental transport of mineral dust and air pollutants. Recent discovery of a nonlocal dynamical driver to the Urban Heat Island effect shows that the adverse impact of urbanization can cascade to exacerbate heat stress, photochemical smog, and haze well downwind. A balanced consideration of meteorology and chemistry not only helps to identify and understand environmental problems, it can also provide powerful, policy relevant science that has led to success stories such as a regional approach to emissions controls and cleaner air over the eastern US.

  4. Spectral broadening and temporal compression of ∼ 100 fs pulses in air-filled hollow core capillary fibers.

    PubMed

    Li, C; Rishad, K P M; Horak, P; Matsuura, Y; Faccio, D

    2014-01-13

    We experimentally study the spectral broadening of intense, ∼ 100 femtosecond laser pulses at 785 nm coupled into different kinds of hollow core capillary fibers, all filled with air at ambient pressure. Differently from observations in other gases, the spectra are broadened with a strong red-shift due to highly efficient intrapulse Raman scattering. Numerical simulations show that such spectra can be explained only by increasing the Raman fraction of the third order nonlinearity close to 100%. Experimentally, these broadened and red-shifted pulses do not generally allow for straightforward compression using, for example, standard chirped mirrors. However, using special hollow fibers that are internally coated with silver and polymer we obtain pulse durations in the sub-20 fs regime with energies up to 300 μJ. PMID:24515074

  5. ENAMAP-1A LONG TERM AIR POLLUTION MODEL: REFINEMENT OF TRANSFORMATION AND DEPOSITION MECHANISMS

    EPA Science Inventory

    This paper is concerned with the long-range transport of air pollution over eastern North America. Using standard weather reports and several SOx emission data inventories, the ENAMAP model computes the airborne concentrations of SO2 and SO4 and their deposition on the earth's su...

  6. Low complexity MIMO method based on matrix transformation for few-mode multi-core optical transmission system

    NASA Astrophysics Data System (ADS)

    Pan, Xiaolong; Liu, Bo; Li, Li; Tian, Qinghua

    2016-07-01

    This paper proposes and demonstrates a low complexity multiple-input multiple-output (MIMO) equalization digital signal processing (DSP) method for the few mode multi-core (FMMC) fiber optical transmission system. The MIMO equalization algorithm offers adaptive equalization taps according to the degree of crosstalk in cores or modes, which eliminates the interference among different modes and cores in space division multiplexing (SDM) transmission system. Compared with traditional MIMO method, the proposed scheme has increased the convergence rate by 4 times and reduced the number of finite impulse response (FIR) filters by 55% when the numbers of mode and core are three.

  7. An Optimized Air-Core Coil Sensor with a Magnetic Flux Compensation Structure Suitable to the Helicopter TEM System

    PubMed Central

    Chen, Chen; Liu, Fei; Lin, Jun; Zhu, Kaiguang; Wang, Yanzhang

    2016-01-01

    The air-core coil sensor (ACS) is widely used as a transducer to measure the variation in magnetic fields of a helicopter transient electromagnetic (TEM) system. A high periodic emitting current induces the magnetic field signal of the underground medium. However, such current also generates a high primary field signal that can affect the received signal of the ACS and even damage the receiver. To increase the dynamic range of the received signal and to protect the receiver when emitting current rises/falls, the combination of ACS with magnetic flux compensation structure (bucking coil) is necessary. Moreover, the optimized ACS, which is composed of an air-core coil and a differential pre-amplifier circuit, must be investigated to meet the requirements of the helicopter TEM system suited to rapid surveying for shallow buried metal mine in rough topography. Accordingly, two ACSs are fabricated in this study, and their performance is verified and compared inside a magnetic shielding room. Using the designed ACSs, field experiments are conducted in Baoqing County. The field experimental data show that the primary field response can be compensated when the bucking coil is placed at an appropriate point in the range of allowed shift distance beyond the center of the transmitting coil and that the damage to the receiver induced by the over-statured signal can be solved. In conclusion, a more suitable ACS is adopted and is shown to have better performance, with a mass of 2.5 kg, resultant effective area of 11.6 m2 (i.e., diameter of 0.496 m), 3 dB bandwidth of 66 kHz, signal-to-noise ratio of 4 (i.e., varying magnetic field strength of 0.2 nT/s), and normalized equivalent input noise of 3.62 nV/m2. PMID:27077862

  8. An Optimized Air-Core Coil Sensor with a Magnetic Flux Compensation Structure Suitable to the Helicopter TEM System.

    PubMed

    Chen, Chen; Liu, Fei; Lin, Jun; Zhu, Kaiguang; Wang, Yanzhang

    2016-01-01

    The air-core coil sensor (ACS) is widely used as a transducer to measure the variation in magnetic fields of a helicopter transient electromagnetic (TEM) system. A high periodic emitting current induces the magnetic field signal of the underground medium. However, such current also generates a high primary field signal that can affect the received signal of the ACS and even damage the receiver. To increase the dynamic range of the received signal and to protect the receiver when emitting current rises/falls, the combination of ACS with magnetic flux compensation structure (bucking coil) is necessary. Moreover, the optimized ACS, which is composed of an air-core coil and a differential pre-amplifier circuit, must be investigated to meet the requirements of the helicopter TEM system suited to rapid surveying for shallow buried metal mine in rough topography. Accordingly, two ACSs are fabricated in this study, and their performance is verified and compared inside a magnetic shielding room. Using the designed ACSs, field experiments are conducted in Baoqing County. The field experimental data show that the primary field response can be compensated when the bucking coil is placed at an appropriate point in the range of allowed shift distance beyond the center of the transmitting coil and that the damage to the receiver induced by the over-statured signal can be solved. In conclusion, a more suitable ACS is adopted and is shown to have better performance, with a mass of 2.5 kg, resultant effective area of 11.6 m² (i.e., diameter of 0.496 m), 3 dB bandwidth of 66 kHz, signal-to-noise ratio of 4 (i.e., varying magnetic field strength of 0.2 nT/s), and normalized equivalent input noise of 3.62 nV/m². PMID:27077862

  9. Transformation of Air Quality Monitor Data from the International Space Station into Toxicological Effect Groups

    NASA Technical Reports Server (NTRS)

    James, John T.; Zalesak, Selina M.

    2011-01-01

    The primary reason for monitoring air quality aboard the International Space Station (ISS) is to determine whether air pollutants have collectively reached a concentration where the crew could experience adverse health effects. These effects could be near-real-time (e.g. headache, respiratory irritation) or occur late in the mission or even years later (e.g. cancer, liver toxicity). Secondary purposes for monitoring include discovery that a potentially harmful compound has leaked into the atmosphere or that air revitalization system performance has diminished. Typical ISS atmospheric trace pollutants consist of alcohols, aldehydes, aromatic compounds, halo-carbons, siloxanes, and silanols. Rarely, sulfur-containing compounds and alkanes are found at trace levels. Spacecraft Maximum Allowable Concentrations (SMACs) have been set in cooperation with a subcommittee of the National Research Council Committee on Toxicology. For each compound and time of exposure, the limiting adverse effect(s) has been identified. By factoring the analytical data from the Air Quality Monitor (AQM), which is in use as a prototype instrument aboard the ISS, through the array of compounds and SMACs, the risk of 16 specific adverse effects can be estimated. Within each adverse-effect group, we have used an additive model proportioned to each applicable 180-day SMAC to estimate risk. In the recent past this conversion has been performed using archival data, which can be delayed for months after an air sample is taken because it must be returned to earth for analysis. But with the AQM gathering in situ data each week, NASA is in a position to follow toxic-effect groups and correlate these with any reported crew symptoms. The AQM data are supplemented with data from real-time CO2 instruments aboard the ISS and from archival measurements of formaldehyde, which the AQM cannot detect.

  10. Geometric structures in hadronic cores of extensive air showers observed by KASCADE

    SciTech Connect

    Antoni, T.; Glasstetter, R.; Hoerandel, J.R.; Roth, M.; Apel, W.D.; Badea, F.; Bekk, K.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R.; Engler, J.; Fessler, F.; Gils, H.J.; Haungs, A.; Heck, D.; Klages, H.O.; Maier, G.; Mathes, H.J.; Mayer, H.J.

    2005-04-01

    The geometric distribution of high-energy hadrons {>=}100 GeV in shower cores measured with the KASCADE calorimeter is analyzed. The data are checked for sensitivity to hadronic interaction features and indications of new physics as discussed in the literature. The angular correlation of the most energetic hadrons and, in particular, the fraction of events with hadrons being aligned are quantified by means of the commonly used parameter {lambda}{sub 4}. The analysis shows that the observed {lambda}{sub 4} distribution is compatible with that predicted by simulations and is not linked to an angular correlation from hadronic jet production at high energy. Another parameter, d{sub 4}{sup max}, describing distances between hadrons measured in the detector, is found to be sensitive both to the transverse momenta in secondary hadron production and the primary particle type. Transverse momenta in high-energy hadron interactions differing by a factor two or more from what is assumed in the standard simulations are disfavored by the measured d{sub 4}{sup max} distribution.

  11. Coherent anti-Stokes Raman scattering in isolated air-guided modes of a hollow-core photonic-crystal fiber

    SciTech Connect

    Fedotov, A.B.; Zheltikov, A.M.; Konorov, S.O.; Mitrokhin, V.P.; Serebryannikov, E.E

    2004-10-01

    Hollow-core photonic-crystal fibers are shown to offer the unique possibility of coherent excitation and probing of Raman-active vibrations in molecules by isolated air-guided modes of electromagnetic radiation. A 3-cm section of a hollow photonic-crystal fiber is used to prepare isolated air-guided modes of pump and probe fields for a coherent excitation of 2331-cm{sup -1} Q-branch vibrations of molecular nitrogen in the gas filling the fiber core, enhancing coherent anti-Stokes Raman scattering through these vibrations by a factor of 15 relative to the regime of tight focusing.

  12. Microfabrication of air core power inductors with metal-encapsulated polymer vias

    SciTech Connect

    Kim, J; Herrault, F; Yu, XH; Kim, M; Shafer, RH; Allen, MG

    2013-01-25

    This paper reports three-dimensional (3-D) microfabricated toroidal inductors intended for power electronics applications. A key fabrication advance is the exploitation of thick metal encapsulation of polymer pillars to form a vertical via interconnections. The radial conductors of the toroidal inductor are formed by conventional plating-through-mold techniques, while the vertical windings (up to 650 mu m in height) are formed by polymer cores with metal plated on their external surfaces. This encapsulated polymer approach not only significantly reduces the required plating time but also exploits the relative ease of fabricating high-aspect-ratio SU-8 pillars. To form the top radial conductors, non-photopatternable SU-8 is introduced as a thick sacrificial layer. Two toroidal inductor geometries were fabricated and tested. The first inductor had an inner diameter of 2 mm, an outer diameter of 6 mm, 25 turns and a vertical via height of 650 mu m. The second inductor had an inner diameter of 4 mm, an outer diameter of 8 mm, 50 turns and a vertical via height of 650 mu m. Both inductor geometries were successfully fabricated and characterized in the frequency range of 0.1-100 MHz. Characterization results of the 25- and 50-turn inductors showed an average inductance of 76 and 200 nH, a low frequency (0.1 MHz) resistance of 0.2 and 1 Omega and a quality factor of 35 and 24 at 100 MHz, respectively. Finite-element simulations of the inductors were performed and agreed with the measured results to within 8%. The turn-to-turn breakdown voltage was measured to be in excess of 800 V and currents as high as 0.5 A could be successfully carried by the inductor windings.

  13. Geomorphic change detection using repetitive topographic surveys and DEMs of Differences: Implementation for short-term transformation of the ice-cored moraines in the Petuniabukta, Svalbard

    NASA Astrophysics Data System (ADS)

    Tomczyk, Aleksandra; Ewertowski, Marek

    2015-04-01

    The exposed glacial forelands are supposed to be intensively transformed by geomorphological processes due to the paraglacial adjustment of the topography. To recognize how high is the activity of such processes, we monitored the transformation rates of ice-cored moraines on the forelands of two glaciers, Ebbabreen and Ragnarbreen, both of which are located near the Petuniabukta at the northern end of the Billefjorden. The main objectives were to: (1) analyse the spatial and temporal aspects of debris flow activity in cm-scale, (2) quantify the short-term (seasonal and intra-seasonal) rate of volume changes, (3) compare transformations of the ice-cored moraine surfaces due to active geomorphic processes (including dead-ice backwasting and debris mass movements) with transformations caused by dead-ice downwasting only. The short-term (yearly and weekly) dynamics of mass-wasting processes were studied in a cm-scale using repetitive topographic scanning. In total, four different locations were scanned, containing seven active debris flows or other mass wasting processes, and including non-active surfaces. Sites were chosen to ensure representation from different parts of the end moraine, different types of dominant processes (debris flows, debris falls, etc.) as well as different types of morphology (exposed ice cliffs, steep debris slope, gentle debris flows lobes, etc.). Altogether, the total scanned area was about 14,200 m2, of which 5,500 m2 were transformed by the active mass movement processes. Ten measurement sessions were carried out: three in summer of 2012, three in summer of 2013, and four in summer of 2014, which allowed for assessing the seasonal (annual) and intra-seasonal (weekly) variations. The results of the surveys in the form of cloud points were used to generate digital elevation models (DEMs) with cell size 0.05 m. Subtracting DEMs from subsequent time periods created DEMs of Differences - DoDs, which enabled us to investigate the volume of and

  14. A preliminary investigation into the use of Red Pine (Pinus Resinosa) tree cores as historic passive samplers of POPs in outdoor air

    NASA Astrophysics Data System (ADS)

    Rauert, Cassandra; Harner, Tom

    2016-09-01

    The suitability of Red Pine trees (Pinus Resinosa) to act as passive samplers for persistent organic pollutants (POPs) in outdoor air and to provide historic information on air concentration trends was demonstrated in this preliminary investigation. Red Pine tree cores from Toronto, Canada, were tested for polycyclic aromatic hydrocarbon (PAHs), alkylated-PAHs, nitro and oxy-PAHs, polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (novel BFRs). The PBDEs and novel BFRs demonstrated a similar relative contribution in cores representing 30 years of tree growth, to that reported in contemporary air samples. Analysis of tree ring segments of 5-15 years resulted in detectable concentrations of some PAHs and alk-PAHs and demonstrated a transition from petrogenic sources to pyrogenic sources over the period 1960-2015. A simple uptake model was developed that treats the tree rings as linear-phase passive air samplers. The bark infiltration factor, IFBARK, is a key parameter of the model that reflects the permeability of the bark to allow chemicals to be transferred from ambient air to the outer tree layer (cambium). An IFBARK of about 2% was derived for the Red Pine trees based on tree core and air monitoring data.

  15. [Transportation and transformation of 14C-phenanthrene in closed chamber (nutrient solution-lava-plant-air) system].

    PubMed

    Jiang, X; Ou, Z; Ying, P; Yediler, A; Ketrrup, A

    2001-06-01

    The transportation and transformation of 14C-phenanthrene in a closed 'plant-lava-nutrient solution-air' chamber system was studied by using radioactivity technology. The results showed that in this closed chamber system, phenanthrene was degraded fast. The radioactivity of 14C left at 23d in the nutrient solution was only 25% of applied. At the end of experiment (46d), the distribution sequence of 14C activity in the components of closed chamber system was root (38.55%) > volatile organic compounds (VOCs, 17.68%) > lava (14.35%) > CO2 (11.42%) > stem (2%). 14C-activities in plant tissue were combined with the tissue, and existed in the forms of lava-bound(root 4.68%; stem and leaves 0.68%) and polar metabolites (root 23.14%; stem 0.78%). PMID:11758435

  16. Panchromatic Fourier Transform Spectrometer (PanFTS) for the Geostationary Coastal and Air Pollution Events (GEO-CAPE)Mission

    NASA Astrophysics Data System (ADS)

    Sander, S. P.; Beer, R.; Blavier, J.; Bowman, K.; Eldering, A.; Rider, D.; Toon, G.; Traub, W.; Worden, J.

    2008-12-01

    The NRC decadal survey proposed the GEO-CAPE and GACM missions to study changes in atmospheric composition and the coastal oceans. To properly address air quality, the decadal survey highlighted the need for vertical profile measurements with sensitivity into the atmospheric boundary layer. The Panchromatic Fourier Transform Spectrometer (PanFTS), a new project within the NASA Instrument Incubator Program, will measure all of the trace species called out in the decadal survey for GEO-CAPE and GACM. With continuous sensitivity from 0.26 to 15 micron and high spectral resolution, PanFTS combines the functionality of separate UV, visible and IR instruments in a single package. These capabilities also permit PanFTS to meet the requirements for high spatial resolution hyperspectral imaging of the coastal zone. This presentation will discuss the design approach and technology development challenges for PanFTS including high speed, high resolution focal plane arrays, and wide spectral coverage optical design.

  17. Panchromatic Fourier Transform Spectrometer (PanFTS) for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission

    NASA Astrophysics Data System (ADS)

    Sander, S. P.; Beer, R.; Blavier, J.; Bowman, K. W.; Eldering, A.; Rider, D.; Toon, G. C.; Traub, W. A.; Worden, J.

    2010-12-01

    The NRC decadal survey of earth science from space proposed the GEO-CAPE and GACM missions to study changes in atmospheric composition, global climate and the coastal oceans. To properly address air quality, the decadal survey highlighted the need for vertical profile measurements with sensitivity into the atmospheric boundary layer. The Panchromatic Fourier Transform Spectrometer (PanFTS), a new project within the NASA Instrument Incubator Program, will measure all of the trace species called out in the decadal survey for GEO-CAPE and GACM. With continuous sensitivity from 0.26 to 15 micron and high spectral resolution, PanFTS combines the functionality of separate UV, visible and IR instruments in a single package. This presentation will discuss the design approach and technology development challenges for PanFTS including high speed, high resolution focal plane arrays, and wide spectral coverage optical design.

  18. Panchromatic Fourier Transform Spectrometer (PanFTS) for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission

    NASA Astrophysics Data System (ADS)

    Sander, S. P.; Beer, R.; Blavier, J. L.; Bowman, K. W.; Eldering, A.; Key, R.; Rider, D.; Toon, G. C.; Traub, W. A.; Worden, J.

    2009-12-01

    The NRC decadal survey proposed the GEO-CAPE and GACM missions to study changes in atmospheric composition and the coastal oceans. To properly address air quality, the decadal survey highlighted the need for vertical profile measurements with sensitivity into the atmospheric boundary layer. The Panchromatic Fourier Transform Spectrometer (PanFTS), a new project within the NASA Instrument Incubator Program, will measure all of the trace species called out in the decadal survey for GEO-CAPE and GACM. With continuous sensitivity from 0.26 to 15 micron and high spectral resolution, PanFTS combines the functionality of separate UV, visible and IR instruments in a single package. These capabilities also permit PanFTS to meet the requirements for high spatial resolution hyperspectral imaging of the coastal zone. This presentation will discuss the design approach and technology development challenges for PanFTS including high speed, high resolution focal plane arrays, and wide spectral coverage optical design.

  19. A centrifugal ice microtome for measurements of atmospheric CO2 on air trapped in polar ice cores

    NASA Astrophysics Data System (ADS)

    Bereiter, B.; Stocker, T. F.; Fischer, H.

    2012-10-01

    For atmospheric CO2 reconstructions using ice cores, the technique to release the trapped air from the ice samples is crucial for the precision and accuracy of the measurements. We present here a new dry extraction technique in combination with a new gas analytical system that together show significant improvements with respect to current systems. Ice samples (3-15 g) are pulverized using a novel Centrifugal Ice Microtome (CIM) by shaving the ice in a cooled vacuum chamber (-27 °C) in which no friction occurs due to the use of magnetic bearings. Both, the shaving principle of the CIM and the use of magnetic bearings have not been applied so far in this field. Shaving the ice samples produces finer ice powder and releases a minimum of 90% of the trapped air compared to 50%-70% when needle crushing is employed. In addition, the friction-free motion with an optimized design to reduce contaminations of the inner surfaces of the device result in a reduced system offset of about 2.0 ppmv compared to 4.9ppmv. The gas analytical part shows a factor two higher precision than our corresponding part of the previous system and all processes except the loading and cleaning of the CIM now run automatically. Compared to our previous system the new system shows a 3 times better measurement reproducibility of about 1.1 ppmv (1σ) which is similar to the best reproducibility of other systems applied in this field. With this high reproducibility, replicate measurements are not required anymore for most prospective measurement campaigns resulting in a possible output of 12-20 measurements per day compared to a maximum of 6 with other systems.

  20. A centrifugal ice microtome for measurements of atmospheric CO2 on air trapped in polar ice cores

    NASA Astrophysics Data System (ADS)

    Bereiter, B.; Stocker, T. F.; Fischer, H.

    2013-02-01

    For atmospheric CO2 reconstructions using ice cores, the technique to release the trapped air from the ice samples is essential for the precision and accuracy of the measurements. We present here a new dry extraction technique in combination with a new gas analytical system that together show significant improvements with respect to current systems. Ice samples (3-15 g) are pulverised using a novel centrifugal ice microtome (CIM) by shaving the ice in a cooled vacuum chamber (-27 °C) in which no friction occurs due to the use of magnetic bearings. Both, the shaving principle of the CIM and the use of magnetic bearings have not been applied so far in this field. Shaving the ice samples produces finer ice powder and releases a minimum of 90% of the trapped air compared to 50%-70% when needle crushing is employed. In addition, the friction-free motion with an optimized design to reduce contaminations of the inner surfaces of the device result in a reduced system offset of about 2.0 ppmv compared to 4.9 ppmv. The gas analytical part shows a higher precision than the corresponding part of our previous system by a factor of two, and all processes except the loading and cleaning of the CIM now run automatically. Compared to our previous system, the complete system shows a 3 times better measurement reproducibility of about 1.1 ppmv (1 σ) which is similar to the best reproducibility of other systems applied in this field. With this high reproducibility, no replicate measurements are required anymore for most future measurement campaigns resulting in a possible output of 12-20 measurements per day compared to a maximum of 6 with other systems.

  1. Characterization of organic material in ice core samples from North America, Greenland, and Antarctica using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry

    NASA Astrophysics Data System (ADS)

    Catanzano, V.; Grannas, A. M.; Sleighter, R. L.; Hatcher, P. G.

    2013-12-01

    Historically, it has been an analytical challenge to detect and identify the organic components present in ice cores, due to the low abundance of organic carbon. In order to detect and characterize the small amounts of organic matter in ice cores, ultra high resolution instrumentation is required. Here we report the use of ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry, coupled with electrospray ionization, to identify the molecular formulas and compound classes of organic matter in both modern and ancient ice core and glacial samples from Wyoming, Greenland, and Antarctica. A suite of 21 samples were analyzed and thousands of distinct molecular species were identified in each sample, providing clues to the nature and sources of organic matter in these regions. Major biochemical classes of compounds were detected such as lignins, tannins, carbohydrates, proteins, lipids, unsaturated hydrocarbons, and condensed aromatic compounds. We will compare the nature of the organic matter present in the samples in order to determine the differences in dominant organic compound classes and in heteroatom (nitrogen and sulfur) abundance. By analyzing these differences, it is possible to investigate the historical patterns of organic matter deposition/source, and begin to investigate the influence of climate change, volcanism, and onset of the industrial revolution on the nature of organic matter preserved in ice cores.

  2. Ringwoodite rim around olivine core in shock-induced melt veins of Antarctic chondrite : Mechanisms of transformation and Fe-Mg diffusion

    NASA Astrophysics Data System (ADS)

    Xie, Z.; Li, X.; Sharp, T. G.; de Carli, P. S.

    2009-12-01

    Introduction: High-pressure minerals, produced by shock metamorphism, are common in and around melt veins in highly shocked chondrites. The shock duration can be constrained by using transformation kinetics, such as the crystallization rate of the melt-vein matrix[1-2], or growth rate of the high-pressure minerals [3-4], or using elements diffusion rate between two minerals [5]. Using transformation kinetics to constrain shock duration de-pend on the details of the transformation mechanism. For example, growth of topotaxial ringwoodite in olivine with coherent interfaces is slower than growth of inclusions with incoherent interfaces [4-5]. Similarly, diffusion-controlled growth, where rates are determined by long-range diffusion, is generally much slower than interface-controlled growth, which is only dependent on diffusion across the interface [6-8]. The occurrences of the high-pressure mineral rims were recently reported in shock-induced melt veins in several heavily shocked (S6) chondrites, ALH78003, Peace River and GRV052049 [9-11]. Here we report EMAP and Raman results of the ringwoodite rims around olivine cores in shock veins of the Antarctic chondrites GRV 022321, and to elucidate the mechanisms of transformation and Mg-Fe diffusion of the olivine to ringwoodite. Results: GRV022321 has a network of black veins which enclose abundant host-rock fragments. The enclosed fragments have sizes ranging from 5 µm to 30 µm, with a brighter rim up to several µm wide and a dark core in reflected light and BSE image. The Raman data reveal that the rim mineral is ringwoodite signature, and the core minerals are dominated by olivine and mixed minor ringwoodite. EMAP data confirm that the ringwoodite in rim is richer in faylite (Fa) than the olivine core. The Fa values range from 50 to 10 with the outer rim having highest Fa value, and the inside darker area with a lower value. Discussion: The occurrence of the rounded shape grains with smooth edges embedded in the fine

  3. Field-induced transformations in the biaxial order of non-tilted phases in a bent-core smectic liquid crystal

    NASA Astrophysics Data System (ADS)

    Panarin, Y. P.; Nagaraj, Mamatha; Vij, J. K.; Keith, C.; Tschierske, C.

    2010-10-01

    The structural and electro-optic investigations of an achiral bent-core molecule in SmAPA phase, in which the polar directors in the neighboring layers are arranged anti-ferroelectrically, show that it undergoes transformation from one biaxial to another biaxial structure via a quasi-stable uniaxial structure on the application of the electric field. The non-continuous change in biaxiality is explained by an intermediate state in which the secondary directors in the neighboring layers are perpendicular to each other.

  4. Computational Assessment of the GT-MHR Graphite Core Support Structural Integrity in Air-Ingress Accident Condition

    SciTech Connect

    Jong B. Lim; Eung S. Kim; Chang H. Oh; Richard R. Schultz; David A. Petti

    2008-10-01

    The objective of this project was to perform stress analysis for graphite support structures of the General Atomics’ 600 MWth GT-MHR prismatic core design using ABAQUS ® (ver. 6.75) to assess their structural integrity in air-ingress accident conditions where the structure weakens over time due to oxidation damages. The graphite support structures of prismatic type GT-MHR was analyzed based on the change of temperature, burn-off and corrosion depth during the accident period predicted by GAMMA, a multi-dimensional gas multi-component mixture analysis code developed in the Republic of Korea (ROK)/United States (US) International –Nuclear Engineering Research Initiative (I-NERI) project. Both the loading and thermal stresses were analyzed, but the thermal stress was not significant, leaving the loading stress to be the major factor. The mechanical strengths are exceeded between 11 to 11.5 days after loss-of-coolant-accident (LOCA), corresponding to 5.5 to 6 days after the start of natural convection.

  5. Temperature dependence of beat-length and confinement loss in an air-core photonic band-gap fiber

    NASA Astrophysics Data System (ADS)

    Xu, Zhenlong; Li, Xuyou; Hong, Yong; Liu, Pan; Yang, Hanrui; Ling, Weiwei

    2016-05-01

    The temperature dependence of polarization-maintaining (PM) property and loss in a highly-birefringent air-core photonic band-gap fiber (PBF) is investigated. The effects of temperature variation on the effective index, beat-length and confinement loss are studied numerically by using the full-vector finite element method (FEM). It is found that, the PM property of this PBF is insensitive to the temperature, and the temperature-dependent beat-length coefficient can be as low as 2.86×10-8 m/°C, which is typically 200 times less than those of conventional panda fibers, the PBF has a stable confinement loss of 0.01 dB/m over the temperature range of -30 to 20 °C for the slow axis at the wavelength of 1.55 μm. The PBF with ultra-low temperature-dependent PM property and low loss can reduce the thermally induced polarization instability apparently in interferometric applications such as resonant fiber optic gyroscope (RFOG), optical fiber sensors, and so on.

  6. Letting the Text Take Center Stage: How the Common Core State Standards Will Transform English Language Arts Instruction

    ERIC Educational Resources Information Center

    Shanahan, Timothy

    2013-01-01

    With the Common Core State Standards, instruction in English language arts will dramatically change. Unlike prior state standards, these new standards place a greater emphasis on reading challenging texts. To that end, teachers will need to support students in paying closer attention to such texts. Instead of focusing on pre-reading activities…

  7. Flow Writing in the Liberal Arts Core and across the Disciplines: A Vehicle for Confronting and Transforming Academic Disengagement

    ERIC Educational Resources Information Center

    Gute, Deanne; Gute, Gary

    2008-01-01

    This study examined the subjective experience of academic disengagement. Flow theory, which describes an intense form of engagement, structured writing-to-learn activities undergraduates applied in major and liberal arts courses. Results suggest that writing to learn can transform academic anxiety and boredom by facilitating concentration,…

  8. Particle distributions in approximately 10(14) 10(16) eV air shower cores at sea level

    NASA Technical Reports Server (NTRS)

    Hodson, A. L.; Ash, A. G.; Bull, R. M.

    1985-01-01

    Experimental evidence is reported for fixed distances (0, 1.0, 2.5 and 4.0 m) from the shower centers and for core flattening. The cores become flatter, on average, as the shower size (primary energy) increases. With improved statistics on 4192 cores, the previous results are exactly confirmed.

  9. First continuous measurements of δ18O-CO2 in air with a Fourier transform infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Vardag, S. N.; Hammer, S.; Sabasch, M.; Griffith, D. W. T.; Levin, I.

    2015-02-01

    The continuous in situ measurement of δ18O in atmospheric CO2 opens a new door to differentiating between CO2 source and sink components with high temporal resolution. Continuous 13C-CO2 measurement systems have already been commercially available for some time, but until now, only few instruments have been able to provide a continuous measurement of the oxygen isotope ratio in CO2. Besides precise 13C/12C observations, the Fourier transform infrared (FTIR) spectrometer is also able to measure the 18O / 16O ratio in CO2, but the precision and accuracy of the measurements have not yet been evaluated. Here we present a first analysis of δ18O-CO2 (and δ13C-CO2) measurements with the FTIR analyser in Heidelberg. We used Allan deviation to determine the repeatability of δ18O-CO2 measurements and found that it decreases from 0.25‰ for 10 min averages to about 0.1‰ after 2 h and remains at that value up to 24 h. We evaluated the measurement precision over a 10-month period (intermediate measurement precision) using daily working gas measurements and found that our spectrometer measured δ18O-CO2 to better than 0.3‰ at a temporal resolution of less than 10 min. The compatibility of our FTIR-spectrometric measurements to isotope-ratio mass-spectrometric (IRMS) measurements was determined by comparing FTIR measurements of cylinder gases and ambient air with IRMS measurements of flask samples, filled with gases of the same cylinders or collected from the same ambient air intake. Two-sample t tests revealed that, at the 0.01 significance level, the FTIR and the IRMS measurements do not differ significantly from each other and are thus compatible. We describe two weekly episodes of ambient air measurements, one in winter and one in summer, and discuss what potential insights and new challenges combined highly resolved CO2, δ13C-CO2 and δ18O-CO2 records may provide in terms of better understanding regional scale continental carbon exchange processes.

  10. Isotopic Composition of Atmospheric Mercury in China: New Evidence for Sources and Transformation Processes in Air and in Vegetation.

    PubMed

    Yu, Ben; Fu, Xuewu; Yin, Runsheng; Zhang, Hui; Wang, Xun; Lin, Che-Jen; Wu, Chuansheng; Zhang, Yiping; He, Nannan; Fu, Pingqing; Wang, Zifa; Shang, Lihai; Sommar, Jonas; Sonke, Jeroen E; Maurice, Laurence; Guinot, Benjamin; Feng, Xinbin

    2016-09-01

    The isotopic composition of atmospheric total gaseous mercury (TGM) and particle-bound mercury (PBM) and mercury (Hg) in litterfall samples have been determined at urban/industrialized and rural sites distributed over mainland China for identifying Hg sources and transformation processes. TGM and PBM near anthropogenic emission sources display negative δ(202)Hg and near-zero Δ(199)Hg in contrast to relatively positive δ(202)Hg and negative Δ(199)Hg observed in remote regions, suggesting that different sources and atmospheric processes force the mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) in the air samples. Both MDF and MIF occur during the uptake of atmospheric Hg by plants, resulting in negative δ(202)Hg and Δ(199)Hg observed in litter-bound Hg. The linear regression resulting from the scatter plot relating the δ(202)Hg to Δ(199)Hg data in the TGM samples indicates distinct anthropogenic or natural influences at the three study sites. A similar trend was also observed for Hg accumulated in broadleaved deciduous forest foliage grown in areas influenced by anthropogenic emissions. The relatively negative MIF in litter-bound Hg compared to TGM is likely a result of the photochemical reactions of Hg(2+) in foliage. This study demonstrates the diagnostic stable Hg isotopic composition characteristics for separating atmospheric Hg of different source origins in China and provides the isotopic fractionation clues for the study of Hg bioaccumulation. PMID:27485289

  11. Hepatitis C Virus Core from Two Different Genotypes Has an Oncogenic Potential but Is Not Sufficient for Transforming Primary Rat Embryo Fibroblasts in Cooperation with the H-ras Oncogene

    PubMed Central

    Chang, Jun; Yang, Se-Hwan; Cho, Young-Gyu; Hwang, Soon Bong; Hahn, Young Shin; Sung, Young Chul

    1998-01-01

    Persistent infection with hepatitis C virus (HCV) is associated with the development of liver cirrhosis and hepatocellular carcinoma. To examine the oncogenic potential of the HCV core gene product, primary rat embryo fibroblasts (REFs) were transfected with the core gene in the presence or absence of the H-ras oncogene. In contrast to a previous report (R. B. Ray, L. M. Lagging, K. Meyer, and R. Ray, J. Virol. 70:4438–4443, 1996), HCV core proteins from two different genotypes (type 1a and type 1b) were not found to transform REFs to tumorigenic phenotype in cooperation with the H-ras oncogene, although the core protein was successfully expressed 20 days after transfection. In addition, REFs transfected with E1A- but not core-expressing plasmid showed the phenotype of immortalized cells when selected with G418. The biological activity was confirmed by observing the transcription activation from two viral promoters, Rous sarcoma virus long terminal repeat and simian virus 40 promoter, which are known to be activated by the core protein from HCV-1 isolate. In contrast to the result with primary cells, the Rat-1 cell line, stably expressing HCV core protein, exhibited focus formation, anchorage-independent growth, and tumor formation in nude mice. HCV core protein was able to induce the transformation of Rat-1 cells with various efficiencies depending on the expression level of the core protein. These results indicate that HCV core protein has an oncogenic potential to transform the Rat-1 cell line but is not sufficient to either immortalize primary REFs by itself or transform primary cells in conjunction with the H-ras oncogene. PMID:9525629

  12. Progress report on a new search for free e/3 quarks in the cores of 10(15) - 10(16) eV air showers

    NASA Technical Reports Server (NTRS)

    Hodson, A. L.; Bull, R. M.; Taylor, R. S.; Belford, C. H.

    1985-01-01

    The Leeds 3 sq m Wilson cloud chamber is being used in a new search for free e/3 quarks close to the axes of 10 to the 15th power - 10 to the 16th power eV air showers. A ratio trigger circuit is used to detect the incidence of air shower cores; the position of the shower center and the axis direction are determined from photographs of current-limited spark chambers. It is thus possible, for the first time, to know where we have looked for quarks in air showers and to select for scanning only those cloud chamber photographs where we have good evidence that the shower axis was close to the chamber. 250 g/sq cm of lead/concrete absorber above the cloud chamber serve to reduce particle densities and make a quark search possible very close to the shower axes. The current status of the search is given.

  13. Ice core sulfur and methanesulfonic acid (MSA) records from southern Greenland document North American and European air pollution and suggest a decline in regional biogenic sulfur emissions.

    NASA Astrophysics Data System (ADS)

    Pasteris, D. R.; McConnell, J. R.; Burkhart, J. F.; Saltzman, E. S.

    2014-12-01

    Sulfate aerosols have an important cooling effect on the Earth because they scatter sunlight back to space and form cloud condensation nuclei. However, understanding of the atmospheric sulfur cycle is incomplete, leading to uncertainty in the assessment of past, present and future climate forcing. Here we use annually resolved observations of sulfur and methanesulfonic acid (MSA) concentration in an array of precisely dated Southern Greenland ice cores to assess the history of sulfur pollution emitted from North America and Europe and the history of biogenic sulfate aerosol derived from the North Atlantic Ocean over the last 250 years. The ice core sulfur time series is found to closely track sulfur concentrations in North American and European precipitation since records began in 1965, and also closely tracks estimated sulfur emissions since 1850 within the air mass source region as determined by back trajectory analysis. However, a decline to near-preindustrial sulfur concentrations in the ice cores after 1995 that is not so extensive in the source region emissions indicates that there has been a change in sulfur cycling over the last 150 years. The ice core MSA time series shows a decline of 60% since the 1860s, and is well correlated with declining sea ice concentrations around Greenland, suggesting that the phytoplankton source of biogenic sulfur has declined due to a loss of marginal sea ice zone habitat. Incorporating the implied decrease in biogenic sulfur in our analysis improves the match between the ice core sulfur record and the source region emissions throughout the last 150 years, and solves the problem of the recent return to near-preindustrial levels in the Greenland ice. These findings indicate that the transport efficiency of sulfur air pollution has been relatively stable through the industrial era and that biogenic sulfur emissions in the region have declined.

  14. Ice core evidence of rapid air temperature increases since 1960 in alpine areas of the Wind River Range, Wyoming, United States

    USGS Publications Warehouse

    Naftz, D.L.; Susong, D.D.; Schuster, P.F.; Cecil, L.D.; Dettinger, M.D.; Michel, R.L.; Kendall, C.

    2002-01-01

    Site-specific transfer functions relating delta oxygen 18 (??18O) values in snow to the average air temperature (TA) during storms on Upper Fremont Glacier (UFG) were used in conjunction with ??18O records from UFG ice cores to reconstruct long-term trends in air temperature from alpine areas in the Wind River Range, Wyoming. Transfer functions were determined by using data collected from four seasonal snowpacks (1989-1990, 1997-1998, 1998-1999, and 1999-2000). The timing and amount of each storm was determined from an automated snowpack telemetry (SNOTEL) site, 22 km northeast of UFG, and ???1060 m in elevation below UFG. Statistically significant and positive correlations between ??18O values in the snow and TA were consistently found in three of the four seasonal snowpacks. The snowpack with the poor correlation was deposited in 1997-1998 during the 1997-1998 El Nin??o Southern Oscillation (ENSO). An ultrasonic snow-depth sensor installed on UFG provided valuable insights into site-specific storms and postdepositional processes that occur on UFG. The timing of storms recorded at the UFG and Cold Springs SNOTEL sites were similar; however, selected storms did not correlate. Snow from storms occurring after mid-October and followed by high winds was most susceptible to redeposition of snow. This removal of lower temperature snowfall could potentially bias the ??18O values preserved in ice core records to environmental conditions reflecting higher air temperatures and lower wind speeds. Transfer functions derived from seasonal snow cover on UFG were used to reconstruct TA values from ??18O values determined from two ice cores collected from UFG. Reconstructed air temperatures from the ice core data indicate an increase in TA of ???3.5??C from the mid-1960s to the early 1990s in the alpine areas of northwestern Wyoming. Reconstructed TA from the ice core records between the end of the Little Ice Age (LIA), mid-1800s, and the early 1990s indicate a TA increase of

  15. A Compact Fiber Inclinometer Using a Thin-Core Fiber with Incorporated an Air-Gap Microcavity Fiber Interferometer

    PubMed Central

    Li, Jiacheng; Qiao, Xueguang; Rong, Qiangzhou; Sun, An

    2016-01-01

    A compact fiber-optic inclinometer is proposed and experimentally demonstrated based on a Fabry-Perot interference (FFPI). The sensing head consists of a short segment of thin-core fiber (TCF) following with a piece of hollow-core fiber (HCF). High-order cladding modes have been excited because of core diameter mismatch. A clear interference spectrum has been obtained as the consequence of interference among the reflected core modes and cladding modes. Fringe contrast of the interference spectrum is highly sensitive to fiber bending with direction independence, and good linearity has been observed during the bending range from 1° to 3° with a sensitivity of 2.71 dB/deg. PMID:26771614

  16. Design of single-winding energy-storage reactors for dc-to-dc converters using air-gapped magnetic-core structures

    NASA Technical Reports Server (NTRS)

    Ohri, A. K.; Wilson, T. G.; Owen, H. A., Jr.

    1977-01-01

    A procedure is presented for designing air-gapped energy-storage reactors for nine different dc-to-dc converters resulting from combinations of three single-winding power stages for voltage stepup, current stepup and voltage stepup/current stepup and three controllers with control laws that impose constant-frequency, constant transistor on-time and constant transistor off-time operation. The analysis, based on the energy-transfer requirement of the reactor, leads to a simple relationship for the required minimum volume of the air gap. Determination of this minimum air gap volume then permits the selection of either an air gap or a cross-sectional core area. Having picked one parameter, the minimum value of the other immediately leads to selection of the physical magnetic structure. Other analytically derived equations are used to obtain values for the required turns, the inductance, and the maximum rms winding current. The design procedure is applicable to a wide range of magnetic material characteristics and physical configurations for the air-gapped magnetic structure.

  17. In-situ, in air, high-temperature phase transformations in rare-earth niobates and titanium oxides (dysprosium and yttrium) using a thermal-image furnace

    NASA Astrophysics Data System (ADS)

    Siah, Lay Foong

    Thermal-image furnaces afford two major advantages over the conventional resistance heating systems for high-temperature studies of oxides in air, namely: (i) the highly localized heating allows temperatures in excess of 2500°C to be reached in air or in an oxidizing atmosphere, and (ii) no sample contamination from volatile furnace components since the sample is heated by absorption of a focused, high intensity light beam. In this work, we developed a compact furnace powered by four halogen infrared reflector lamps (150 W each), for in-situ high-temperature studies using synchrotron radiation. The primary objective was to evaluate the feasibility of the thermal-image technique for in-situ, in air, studies of high-temperature phase transformations in oxide ceramics. Specifically, the issues of temperature measurement and reliability of results obtained in comparison with published literature were addressed. The use of a co-existent "in-situ thermometer" was found to be a viable method to monitor the sample temperature in the image "hot-spot". Studies of YNbO4 and DyNbO4 revealed the existence of a new cubic phase at elevated temperatures beyond the commonly known ferroelastic monoclinic-to-paraelastic tetragonal transformations. A series of high-temperature powder patterns of the pure hexagonal phase of DY2TiO5 was also collected in-situ, in air.

  18. Ambient formic acid in southern California air: A comparison of two methods, Fourier transform infrared spectroscopy and alkaline trap-liquid chromatography with UV detection

    SciTech Connect

    Grosjean, D. ); Tuazon, E.C. ); Fujita, E. )

    1990-01-01

    Formic acid is an ubiquitous component of urban smog. Sources of formic acid in urban air include direct emissions from vehicles and in situ reaction of ozone with olefins. Ambient levels of formic acid in southern California air were first measured some 15 years ago by Hanst et al. using long-path Fourier transform infrared spectroscopy (FTIR). All subsequent studies of formic acid in the Los Angeles area have involved the use of two methods, either FTIR or collection on alkaline traps followed by gas chromatography, ion chromatography, or liquid chromatography analysis with UV detection, ATLC-UV. The Carbon Species Methods Comparison Study (CSMCS), a multilaboratory air quality study carried out in August 1986 at a southern California smog receptor site, provided an opportunity for direct field comparison of the FTIR and alkaline trap methods. The results of the comparison are presented in this brief report.

  19. Face Sheet/Core Disbond Growth in Honeycomb Sandwich Panels Subjected to Ground-Air-Ground Pressurization and In-Plane Loading

    NASA Technical Reports Server (NTRS)

    Chen, Zhi M.; Krueger, Ronald; Rinker, Martin

    2015-01-01

    Typical damage modes in light honeycomb sandwich structures include face sheet/core disbonding and core fracture, both of which can pose a threat to the structural integrity of a component. These damage modes are of particular interest to aviation certification authorities since several in-service occurrences, such as rudder structural failure and other control surface malfunctions, have been attributed to face sheet/core disbonding. Extensive studies have shown that face sheet/core disbonding and core fracture can lead to damage propagation caused by internal pressure changes in the core. The increasing use of composite sandwich construction in aircraft applications makes it vitally important to understand the effect of ground-air-ground (GAG) cycles and conditions such as maneuver and gust loads on face sheet/core disbonding. The objective of the present study was to use a fracture mechanics based approach developed earlier to evaluate the loading at the disbond front caused by ground-air-ground pressurization and in-plane loading. A honeycomb sandwich panel containing a circular disbond at one face sheet/core interface was modeled with three-dimensional (3D) solid finite elements. The disbond was modeled as a discrete discontinuity and the strain energy release rate along the disbond front was computed using the Virtual Crack Closure Technique (VCCT). Special attention was paid to the pressure-deformation coupling which can decrease the pressure load within the disbonded sandwich section significantly when the structure is highly deformed. The commercial finite element analysis software, Abaqus/Standard, was used for the analyses. The recursive pressure-deformation coupling problem was solved by representing the entrapped air in the honeycomb cells as filled cavities in Abaqus/Standard. The results show that disbond size, face sheet thickness and core thickness are important parameters that determine crack tip loading at the disbond front. Further, the pressure

  20. Extraction of weak PcP phases using the slant-stacklet transform - II: constraints on lateral variations of structure near the core-mantle boundary

    NASA Astrophysics Data System (ADS)

    Ventosa, Sergi; Romanowicz, Barbara

    2015-11-01

    Resolving the topography of the core-mantle boundary (CMB) and the structure and composition of the D″ region is key to improving our understanding of the interaction between the Earth's mantle and core. Observations of traveltimes and amplitudes of short-period teleseismic body waves sensitive to lowermost mantle provide essential constraints on the properties of this region. Major challenges are low signal-to-noise ratio of the target phases and interference with other mantle phases. In a previous paper (Part I), we introduced the slant-stacklet transform to enhance the signal of the core-reflected (PcP) phase and to isolate it from stronger signals in the coda of the P wave. Then we minimized a linear misfit between P and PcP waveforms to improve the quality of PcP-P traveltime difference measurements as compared to standard cross-correlation methods. This method significantly increases the quantity and the quality of PcP-P traveltime observations available for the modelling of structure near the CMB. Here we illustrate our approach in a series of regional studies of the CMB and D″ using PcP-P observations with unprecedented resolution from high-quality dense arrays located in North America and Japan for events with magnitude Mw>5.4 and distances up to 80°. In this process, we carefully analyse various sources of errors and show that mantle heterogeneity is the most significant. We find and correct bias due to mantle heterogeneities that is as large as 1 s in traveltime, comparable to the largest lateral PcP-P traveltime variations observed. We illustrate the importance of accurate mantle corrections and the need for higher resolution mantle models for future studies. After optimal mantle corrections, the main signal left is relatively long wavelength in the regions sampled, except at the border of the Pacific large-low shear velocity province (LLSVP). We detect the northwest border of the Pacific LLSVP in the western Pacific from array observations in

  1. 28-Channel rotary transformer

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1981-01-01

    Transformer transmits power and digital data across rotating interface. Array has many parallel data channels, each with potential l megabaud data rate. Ferrite-cored transformers are spaced along rotor; airgap between them reduces crosstalk.

  2. EVALUATION OF A PORTABLE FOURIER TRANSFORM INFRARED GAS ANALYZER FOR MEASUREMENTS OF AIR TOXICS IN POLLUTION PREVENTION RESEARCH

    EPA Science Inventory

    A portable Fourier transform infrared gas analyzer with a photoacoustic detector performed reliably during pollution prevention research at two industrial facilities. It exhibited good agreement (within approximately 6%) with other analytical instruments (dispersive infrared and ...

  3. Results from Geothermal Logging, Air and Core-Water Chemistry Sampling, Air Injection Testing and Tracer Testing in the Northern Ghost Dance Fault, YUCCA Mountain, Nevada, November 1996 to August 1998

    SciTech Connect

    Lecain, G.D.; Anna, L.O.; Fahy, M.F.

    1998-08-01

    Geothermal logging, air and core-water chemistry sampling, air-injection testing, and tracer testing were done in the northern Ghost Dance Fault at Yucca Mountain, Nevada, from November 1996 to August 1998. The study was done by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy. The fault-testing drill room and test boreholes were located in the crystal-poor, middle nonlithophysal zone of the Topopah Spring Tuff, a tuff deposit of Miocene age. The drill room is located off the Yucca Mountain underground Exploratory Studies Facility at about 230 meters below ground surface. Borehole geothermal logging identified a temperature decrease of 0.1 degree Celsius near the Ghost Dance Fault. The temperature decrease could indicate movement of cooler air or water, or both, down the fault, or it may be due to drilling-induced evaporative or adiabatic cooling. In-situ pneumatic pressure monitoring indicated that barometric pressure changes were transmitted from the ground surface to depth through the Ghost Dance Fault. Values of carbon dioxide and delta carbon-13 from gas samples indicated that air from the underground drill room had penetrated the tuff, supporting the concept of a well-developed fracture system. Uncorrected carbon-14-age estimates from gas samples ranged from 2,400 to 4,500 years. Tritium levels in borehole core water indicated that the fault may have been a conduit for the transport of water from the ground surface to depth during the last 100 years.

  4. Solar and volcanic forcing of summer air temperatures - a combined ice core and tree ring perspective form the Carpathian Mts. (Europe)

    NASA Astrophysics Data System (ADS)

    Perşoiu, Aurel; Popa, Ionel

    2014-05-01

    In order to improve our understanding of natural and anthropogenic influences on climate, high resolution reconstruction of the climate changes (and associated forcings) during the recent past (last millennium) are strongly needed. While these types of records are available for numerous regions, they are still scarce and with low resolution in the Eastern half of the European continent. In this paper, we present a high-resolution (decadal and better) reconstruction of summer air temperatures from the Carpathian Mts. (Romania), using water stable isotopes in cave ice cores (from Scărişoara Ice Cave) and tree-rings as proxies for summer air temperatures (late and early, respectively). Our combined results show that periods of low solar activity (Wolf, Spörer and Dalton) and the main volcanic eruptions of the past millennium had had a clearly visible - in both isotope and tree ring data - impact on summer temperatures in the area. Worth to mention is that the "year without a summer" occurred in 1818 in both records, two years later than in most of the reconstructions in the vicinity. The Medieval Warm Period is seen as a relatively warm (~0.5 °C warmer than the 1960-1990 period) and stable period in the ice core data, but it's not clearly recorded by the tree rings, while the Little Ice Age (starting at around 1350 in the 14C-dated ice core chronology, and in 1370 in the annually resolved tree ring data) is marked by lower than present (by ~ 1 °C) air temperatures and increased variability. The ice core record stops at 1870 AD due to enhanced ice melting in the 20th century, associated with drier and warmer summer, as seen in the tree ring reconstruction. Our results provide a unique picture of the climate during the past millennium for a region where such information is mostly missing, strengthening the general view of 1) a relatively variable climate during the past 1000 years and 2) rapid warming during the past ~100 years.

  5. Design study of an air pump and integral lift engine ALF-504 using the Lycoming 502 core

    NASA Technical Reports Server (NTRS)

    Rauch, D.

    1972-01-01

    Design studies were conducted for an integral lift fan engine utilizing the Lycoming 502 fan core with the final MQT power turbine. The fan is designed for a 12.5 bypass ratio and 1.25:1 pressure ratio, and provides supercharging for the core. Maximum sea level static thrust is 8370 pounds with a specific fuel consumption of 0.302 lb/hr-lb. The dry engine weight without starter is 1419 pounds including full-length duct and sound-attenuating rings. The engine envelope including duct treatment but not localized accessory protrusion is 53.25 inches in diameter and 59.2 inches long from exhaust nozzle exit to fan inlet flange. Detailed analyses include fan aerodynamics, fan and reduction gear mechanical design, fan dynamic analysis, engine noise analysis, engine performance, and weight analysis.

  6. Characterization of the Aldehydes and Their Transformations Induced by UV Irradiation and Air Exposure of White Guanxi Honey Pummelo (Citrus Grandis (L.) Osbeck) Essential Oil.

    PubMed

    Li, Li Jun; Hong, Peng; Chen, Feng; Sun, Hao; Yang, Yuan Fan; Yu, Xiang; Huang, Gao Ling; Wu, Li Ming; Ni, Hui

    2016-06-22

    Aldehydes are key aroma contributors of citrus essential oils. White Guanxi honey pummelo essential oil (WPEO) was investigated in its aldehyde constituents and their transformations induced by UV irradiation and air exposure by GC-MS, GC-O, and sensory evaluation. Nine aldehydes, i.e., octanal, nonanal, citronellal, decanal, trans-citral, cis-citral, perilla aldehyde, dodecanal, and dodecenal, were detected in WPEO. After treatment, the content of citronellal increased, but the concentrations of other aldehydes decreased. The aliphatic aldehydes were transformed to organic acids. Citral was transformed to neric acid, geranic acid, and cyclocitral. Aldehyde transformation caused a remarkable decrease in the minty, herbaceous, and lemon notes of WPEO. In fresh WPEO, β-myrcene, d-limonene, octanal, decanal, cis-citral, trans-citral, and dodecenal had the highest odor dilution folds. After the treatment, the dilution folds of decanal, cis-citral, trans-citral, and dodecenal decreased dramatically. This result provides information for the production and storage of aldehyde-containing products. PMID:27226192

  7. Workplace and environmental air contaminant concentrations measured by open path Fourier transform infrared spectroscopy: a statistical process control technique to detect changes from normal operating conditions.

    PubMed

    Malachowski, M S; Levine, S P; Herrin, G; Spear, R C; Yost, M; Yi, Z

    1994-05-01

    Open path Fourier transform infrared (OP-FTIR) spectroscopy is a new air monitoring technique that can be used to measure concentrations of air contaminants in real or near-real time. OP-FTIR spectroscopy has been used to monitor workplace gas and vapor exposures, emissions from hazardous waste sites, and to track emissions along fence lines. This paper discusses a statistical process control technique that can be used with air monitoring data collected with an OP-FTIR spectrometer to detect departures from normal operating conditions in the workplace or along a fence line. Time series data, produced by plotting consecutive air sample concentrations in time, were analyzed. Autocorrelation in the time series data was removed by fitting dynamic models. Control charts were used with the residuals of the model fit data to determine if departures from defined normal operating conditions could be rapidly detected. Shewhart and exponentially weighted moving average (EWMA) control charts were evaluated for use with data collected under different room air flow and mixing conditions. Under rapidly changing conditions the Shewhart control chart was able to detect a leak in a simulated process area. The EWMA control chart was found to be more sensitive to drifts and slowly changing concentrations in air monitoring data. The time series and statistical process control techniques were also applied to data obtained during a field study at a chemical plant. A production area of an acrylonitrile, 1,3-butadiene, and styrene (ABS) polymer process was monitored in near-real time. Decision logics based on the time series and statistical process control technique introduced suggest several applications in workplace and environmental monitoring. These applications might include signaling of an alarm or warning, increasing levels of worker respiratory protection, or evacuation of a community, when gas and vapor concentrations are determined to be out-of-control. PMID:8012765

  8. Dynamic real-time monitoring of chloroform in an indoor swimming pool air using open-path Fourier transform infrared spectroscopy.

    PubMed

    Chen, M-J; Duh, J-M; Shie, R-H; Weng, J-H; Hsu, H-T

    2016-06-01

    This study used open-path Fourier transform infrared (OP-FTIR) spectroscopy to continuously assess the variation in chloroform concentrations in the air of an indoor swimming pool. Variables affecting the concentrations of chloroform in air were also monitored. The results showed that chloroform concentrations in air varied significantly during the time of operation of the swimming pool and that there were two peaks in chloroform concentration during the time of operation of the pool. The highest concentration was at 17:30, which is coincident with the time with the highest number of swimmers in the pool in a day. The swimmer load was one of the most important factors influencing the chloroform concentration in the air. When the number of swimmers surpassed 40, the concentrations of chloroform were on average 4.4 times higher than the concentration measured without swimmers in the pool. According to the results of this study, we suggest that those who swim regularly should avoid times with highest number of swimmers, in order to decrease the risk of exposure to high concentrations of chloroform. It is also recommended that an automatic mechanical ventilation system is installed to increase the ventilation rate during times of high swimmer load. PMID:25916255

  9. Ocean core complexes within Non-transform discontinuities and hydrothermal mineralizations on the Central Indian Ridge between 17°S and 5°S

    NASA Astrophysics Data System (ADS)

    Pak, S.; Kim, H.; Kim, J.; Moon, J.; Choi, S.

    2012-12-01

    Mantle rocks exposure within basaltic basement along the mid-ocean ridge, so called, ocean core complex (OCC) have been intensively researched for their high abundances of hydrothermal activities as well as interesting oceanic crust sequences in present decade. However, most studies on OCC are limited to TAG area in slow-spreading ridge and SWIR in ultra slow-spreading ridge. Here we firstly report survey results of the Central Indian Ridge (CIR) between 17°S and 5°S and illuminate distribution patterns of ocean core complexes at non-transform discontinuities (NTD) as well as potentialities of deep-sea hydrothermal activities within OCC. CIR spreading axis between 17°S and 5°S are separated by three major transform offsets at Vema fracture zone (9°30'S), Argo fracture zone (13°30'S) and Marie Celeste fracture zone (17°S), i.e., three first-order segments. First-order segments can be subdevided by NTD and small-scale discontinuities into seven second-order segments. Four OCCs are situated on end of small-scale discontinuities and two OCCs are adjacent to NTDs. Generally, OCCs founded at 8°S (segment 1) and 11°S (segment 3) are consisted of ultramafic rock and gabbroic rock and featured by the corrugated structures. However, OCCs at 12°S and 15°30'S are founded in a typical the uplifted and elongated-shape NTDs where serpentinite and/or gabbroic rocks were recovered. OCC at 12°S shows unique bridge-shape NTD and both tips of the NTD link with other OCCs at rifting valley flanks. The northern part of OCC on 12°S is mostly comprised of gabbroic rocks whereas serpentinite was dominantly sampled in the southern part of OCC. At 15°30'S OCC displays septum structure and splits southern part of segment 6 into two parts. Gabbroic rocks and serpentinite are dominant rocks of eastern part and western part of NTD, respectively. The bridge- and septum-shape OCCs in NTDs at 12°S and 15°30'S are unusual ones because those OCCs show so elongated and narrow features

  10. High birefringent rectangular-lattice photonic crystal fibers with low confinement loss employing different sizes of elliptical air holes in the cladding and the core

    NASA Astrophysics Data System (ADS)

    Liao, Jianfei; Sun, Junqiang

    2012-12-01

    Based on the full-vector finite element method with anisotropic perfectly matched layers, modal birefringence and confinement loss for the fundamental mode in rectangular-lattice photonic crystal fibers with different sizes of elliptical air holes in the cladding and the core are investigated numerically. The results show that the modal birefringence in this proposed photonic crystal fibers can be up to 5.64 × 10-2 at the wavelength of 1.55 μm. Moreover, when the birefringence is higher than 4 × 10-2, the confinement loss of x-polarized mode can be kept less than 0.005 dB/km at 1.55 μm. It means that the tradeoff between the high birefringence and the low confinement loss is overcome.

  11. High-symmetry hydrogen-bonded organic frameworks: air separation and crystal-to-crystal structural transformation.

    PubMed

    Zhou, Dong-Dong; Xu, Yan-Tong; Lin, Rui-Biao; Mo, Zong-Wen; Zhang, Wei-Xiong; Zhang, Jie-Peng

    2016-04-11

    By changing the size of a substituent group, benzotrisimidazoles can self-assembly to give a honeycomb-like (hcb) layer or a three-dimensional (10,3)-a (srs) network. While the former is highly stable and rigid with little porosity, the latter can undergo a water-induced reversible crystal-to-crystal transformation and selectively adsorb O2 over Ar and N2. PMID:26932390

  12. Study of field-pole Bi2223 windings of air core type for a HTS propulsion motor

    NASA Astrophysics Data System (ADS)

    Sugyo, D.; Kimura, Y.; Sano, T.; Yamaguchi, K.; Izumi, M.; Miki, M.; Ohmatu, K.; Fukumoto, Y.; Fujimoto, H.

    2008-02-01

    In the present study, we designed a field pole of Bi2223 superconductor winding without iron core applied to high-temperature superconducting (HTS) motor of an axial gap type. As the preliminary step to form a field pole winding, we designed a double-pancake-coil (DPC) and qualified relationship between the terminal voltage and the excitation current. We adopted the structure of HTS winding field pole composed of stacked two layered DPC because of effective conduction cooling and electromagnetic effect. We manufactured 16 poles DPC and verified the critical current vs. terminal voltage at 77 K with liquid nitrogen. To form a rotor, 8 field-pole HTS windings were manufactured by integrating of two DPCs as a split coil. We measured the coil Ic and voltage drop of the terminal at 30 K cooled with gas-liquid mixing helium and qualified the heat generation from the coils with DC current excitation. The cooling and excitation test of the constructed field pole coils were performed in the testing motor. The results exhibit that presently developed coils possesses sufficient performance on the heat generation and the magnetic flux density in the axial-type machine under construction.

  13. Dual-core antiresonant hollow core fibers.

    PubMed

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing

    2016-07-25

    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters. PMID:27464191

  14. Interfacial redox reaction-directed synthesis of silver@cerium oxide core-shell nanocomposites as catalysts for rechargeable lithium-air batteries

    NASA Astrophysics Data System (ADS)

    Liu, Ying; Wang, Man; Cao, Lu-Jie; Yang, Ming-Yang; Ho-Sum Cheng, Samson; Cao, Chen-Wei; Leung, Kwan-Lan; Chung, Chi-Yuen; Lu, Zhou-Guang

    2015-07-01

    A facile oxidation-reduction reaction method has been implemented to prepare pomegranate-like Ag@CeO2 multicore-shell structured nanocomposites. Under Ar atmosphere, redox reaction automatically occurs between AgNO3 and Ce(NO3)3 in an alkaline solution, where Ag+ is reduced to Ag nanopartilces and Ce3+ is simultaneously oxidized to form CeO2, followed by the self-assembly to form the pomegranate-like multicore-shell structured Ag@CeO2 nanocomposites driven by thermodynamic equilibrium. No other organic amines or surfactants are utilized in the whole reaction system and only NaOH instead of organic reducing agent is used to prevent the introduction of a secondary reducing byproduct. The as-obtained pomegranate-like Ag@CeO2 multicore-shell structured nanocomposites have been characterized as electro-catalysts for the air cathode of lithium-air batteries operated in a simulated air environment. Superior electrochemical performance with high discharge capacity of 3415 mAh g-1 at 100 mA g-1, stable cycling and small charge/discharge polarization voltage is achieved, which is much better than that of the CeO2 or simple mixture of CeO2 and Ag. The enhanced properties can be primarily attributed to the synergy effect between the Ag core and the CeO2 shell resulting from the unique pomegranate-like multicore-shell nanostructures possessing plenty of active sites to promote the facile formation and decomposition of Li2O2.

  15. Air-snow transfer of nitrate on the East Antarctic Plateau - Part 2: An isotopic model for the interpretation of deep ice-core records

    NASA Astrophysics Data System (ADS)

    Erbland, J.; Savarino, J.; Morin, S.; France, J. L.; Frey, M. M.; King, M. D.

    2015-10-01

    Unraveling the modern budget of reactive nitrogen on the Antarctic Plateau is critical for the interpretation of ice-core records of nitrate. This requires accounting for nitrate recycling processes occurring in near-surface snow and the overlying atmospheric boundary layer. Not only concentration measurements but also isotopic ratios of nitrogen and oxygen in nitrate provide constraints on the processes at play. However, due to the large number of intertwined chemical and physical phenomena involved, numerical modeling is required to test hypotheses in a quantitative manner. Here we introduce the model TRANSITS (TRansfer of Atmospheric Nitrate Stable Isotopes To the Snow), a novel conceptual, multi-layer and one-dimensional model representing the impact of processes operating on nitrate at the air-snow interface on the East Antarctic Plateau, in terms of concentrations (mass fraction) and nitrogen (δ15N) and oxygen isotopic composition (17O excess, Δ17O) in nitrate. At the air-snow interface at Dome C (DC; 75° 06' S, 123° 19' E), the model reproduces well the values of δ15N in atmospheric and surface snow (skin layer) nitrate as well as in the δ15N profile in DC snow, including the observed extraordinary high positive values (around +300 ‰) below 2 cm. The model also captures the observed variability in nitrate mass fraction in the snow. While oxygen data are qualitatively reproduced at the air-snow interface at DC and in East Antarctica, the simulated Δ17O values underestimate the observed Δ17O values by several per mill. This is explained by the simplifications made in the description of the atmospheric cycling and oxidation of NO2 as well as by our lack of understanding of the NOx chemistry at Dome C. The model reproduces well the sensitivity of δ15N, Δ17O and the apparent fractionation constants (15ϵapp, 17Eapp) to the snow accumulation rate. Building on this development, we propose a framework for the interpretation of nitrate records

  16. Air-snow transfer of nitrate on the East Antarctic plateau - Part 2: An isotopic model for the interpretation of deep ice-core records

    NASA Astrophysics Data System (ADS)

    Erbland, J.; Savarino, J.; Morin, S.; France, J. L.; Frey, M. M.; King, M. D.

    2015-03-01

    Unraveling the modern budget of reactive nitrogen on the Antarctic plateau is critical for the interpretation of ice core records of nitrate. This requires accounting for nitrate recycling processes occurring in near surface snow and the overlying atmospheric boundary layer. Not only concentration measurements, but also isotopic ratios of nitrogen and oxygen in nitrate, provide constraints on the processes at play. However, due to the large number of intertwined chemical and physical phenomena involved, numerical modelling is required to test hypotheses in a quantitative manner. Here we introduce the model "TRansfer of Atmospheric Nitrate Stable Isotopes To the Snow" (TRANSITS), a novel conceptual, multi-layer and one-dimensional model representing the impact of processes operating on nitrate at the air-snow interface on the East Antarctic plateau, in terms of concentrations (mass fraction) and the nitrogen (δ15N) and oxygen isotopic composition (17O}-excess, Δ17O) in nitrate. At the air-snow interface at Dome C (DC, 75°06' S, 123°19' E), the model reproduces well the values of δ15N in atmospheric and surface snow (skin layer) nitrate as well as in the δ15N profile in DC snow including the observed extraordinary high positive values (around +300 ‰) below 20 unit{cm}. The model also captures the observed variability in nitrate mass fraction in the snow. While oxygen data are qualitatively reproduced at the air-snow interface at DC and in East Antarctica, the simulated Δ17O values underestimate the observed Δ17O values by a few ‰. This is explained by the simplifications made in the description of the atmospheric cycling and oxidation of NO2. The model reproduces well the sensitivity of δ15N, Δ17O and the apparent fractionation constants (15ϵapp, 17Eapp) to the snow accumulation rate. Building on this development, we propose a framework for the interpretation of nitrate records measured from ice cores. Measurement of nitrate mass fractions

  17. Fabrication and characterization of carbon nanofiber@mesoporous carbon core-shell composite for the Li-air battery

    NASA Astrophysics Data System (ADS)

    Song, Myeong Jun; Shin, Moo Whan

    2014-11-01

    In this study, we successfully design and synthesize the mesoporous carbon coated carbon nanofibers (CNF@mesoCs) for the Li-air battery. The composites are fabricated via electrospinning technique and nanocasting strategy. After mesoporous carbon coating process, the composites have retained their original one-dimensional structure as pristine carbon nanofibers. Every nanofiber entangles with each other to form a three-dimensional cross-linked web structure. Because of the mesoporous carbon coating on carbon nanofibers, the surface area increases from 708 m2 g-1 to 2194 m2 g-1. We confirm that the mesoporous carbon coated on carbon nanofibers is well-graphitized by analysis of Raman spectra. The graphitized surface of CNF@mesoCs (4.638 S cm-1) is believed to result in their higher electrical conductivity than that of pristine carbon nanofibers (3.0759 S cm-1). Without employment of any binders and metal foams, the cathode of CNF@mesoCs exhibits high discharge capacity of 4000 mA h g-1, which is much higher than that from pristine carbon nanofibers (2750 mA h g-1). This work demonstrates that the fabricated CNF@mesoCs structures have a great potential to be employed as light-weight and efficient electrode for energy storage and conversion devices.

  18. Transforming the recognition site of 4-hydroxyaniline into 4-methoxyaniline grafted onto a BODIPY core switches the selective detection of peroxynitrite to hypochlorous acid.

    PubMed

    Zhao, Chunchang; An, Jiancai; Zhou, Li; Fei, Qiang; Wang, Feiyi; Tan, Jie; Shi, Ben; Wang, Rui; Guo, Zhiqian; Zhu, Wei-Hong

    2016-02-01

    Two novel probes were designed, sharing the same BODIPY core but differing only by a minimized variation in the recognition site from 4-hydroxyaniline into 4-methoxyaniline. Such a small change in the reaction site could switch the selective detection from peroxynitrite to HOCl. Undoubtedly, the new designed BODIPY core exhibits valuable properties. PMID:26688579

  19. Step-Scan T-Cell Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) for Monitoring Environmental Air Pollutants

    NASA Astrophysics Data System (ADS)

    Liu, Lixian; Mandelis, Andreas; Melnikov, Alexander; Michaelian, Kirk; Huan, Huiting; Haisch, Christoph

    2016-07-01

    Air pollutants have adverse effects on the Earth's climate system. There is an urgent need for cost-effective devices capable of recognizing and detecting various ambient pollutants. An FTIR photoacoustic spectroscopy (FTIR-PAS) method based on a commercial FTIR spectrometer developed for air contamination monitoring will be presented. A resonant T-cell was determined to be the most appropriate resonator in view of the low-frequency requirement and space limitations in the sample compartment. Step-scan FTIR-PAS theory for regular cylinder resonator has been described as a reference for prediction of T-cell vibration principles. Both simulated amplitude and phase responses of the T-cell show good agreement with measurement data Carbon dioxide IR absorption spectra were used to demonstrate the capacity of the FTIR-PAS method to detect ambient pollutants. The theoretical detection limit for carbon dioxide was found to be 4 ppmv. A linear response to carbon dioxide concentration was found in the range from 2500 ppmv to 5000 ppmv. The results indicate that it is possible to use step-scan FTIR-PAS with a T-cell as a quantitative method for analysis of ambient contaminants.

  20. The Potential Impact of CO2 and Air Temperature Increases on Krummholz's Transformation into Arborescent Form in the Southern Siberian Mountains

    NASA Technical Reports Server (NTRS)

    Kharuk, V. I.; Dvinskaya, M. L.; Im, S. T.; Ranson, K. J.

    2011-01-01

    Trees in the southern Siberian Mountains forest-tundra ecotone have considerably increased their radial and apical growth increments during the last few decades. This leads to the widespread vertical transformation of mat and prostrate krummholz forms of larch (Larix sibirica Ledeb) and Siberian pine (Pinus sibirica Du Tour). An analysis of the radial growth increments showed that these transformations began in the mid-1980s. Larch showed a greater resistance to the harsh alpine environment and attained a vertical growth form in areas where Siberian pine is still krummholz. Upper larch treeline is about 10 m higher than Siberian pine treeline. Observed apical and radial growth increment increases were correlated with CO2 concentration (r = 0.83-0.87), summer temperatures (r = 0.55-0.64), and "cold period" (i.e. September-May) air temperatures (r = 0.36-0.37). Positive correlation between growth increments and winter precipitation was attributed to snow cover protection for trees during wintertime.

  1. Source fingerprint monitoring of air pollutants from petrochemical industry and the determination of their annual emission flux using open path Fourier transform infrared spectroscopy

    SciTech Connect

    Yih-Shiaw Huang; Shih-Yi Chang; Tai-Ly Tso

    1996-12-31

    Toxic air pollutants were investigated in several petrochemical industrial park in Taiwan using a movable open-path Fourier-transform infrared spectroscopy (FTIR). The results show the qualitative and quantitative analysis of emission gases from plants, and also provide the emission rates of various compounds. More than twenty compounds under usual operation were found from these industrial park. The concentration variation with time could be correlated exactly with the distances from the emission source along the wind direction. This means that by changing the measuring points the source of emission could be unambiguously identified. The point, area and line source (PAL) plume dispersion model has been applied to estimate the emission rate of either a point or an area source. The local atmospheric stability was determined by releasing an SF{sub 6} tracer. The origin of errors came mainly from the uncertainty of the source configuration and the variation of the meteorological condition. Through continuous measurement using a portable open-path Fourier transform infrared (POP-FTIR) spectrometer, the maximum value of the emission rate and the annual amount of emission could be derived. The emission rate of the measured toxic gases was derived by the model technique, and the results show that the emission amount is on the order of ten to hundred tons per year.

  2. A new laser spectrometer for measurements of the carbon isotope ratio (δ13C) of methane in air and applications to ice core studies

    NASA Astrophysics Data System (ADS)

    Lee, J. E.; Brook, E.; Dong, F.; Gupta, M.

    2012-12-01

    Methane is the second most important anthropogenic greenhouse gas contributing to global climate change, and yet its sources and sinks are still poorly understood. Isotopic ratios of methane released to the atmosphere depend on the isotopic composition of the source and fractionation by sink processes. Analysis of isotopic compositions can provide further understanding of methane source strength and location. Traditional measurements by mass spectrometry are laborious and not easily adaptable to new continuous gas extraction methodologies. Recent technological advances have reduced the amount of methane necessary for precise measurements of δ13C in methane by laser spectrometry to a practical sample size for ice core studies. We present a new laser-based analyzer for measurement of δ13C in methane that requires less than 6 μmol of CH4. Current precision is better than ±0.5‰ (1σ, 100 seconds) on dry air with [CH4]= 2ppm. The sensor is operable in either discrete or continuous sampling modes allowing for continuous measurement of gas sample exhausted from other analyzers. Detailed performance characteristics and tests will be discussed at the meeting.

  3. Stereo matching using epipolar distance transform.

    PubMed

    Yang, Qingxiong; Ahuja, Narendra

    2012-10-01

    In this paper, we propose a simple but effective image transform, called the epipolar distance transform, for matching low-texture regions. It converts image intensity values to a relative location inside a planar segment along the epipolar line, such that pixels in the low-texture regions become distinguishable. We theoretically prove that the transform is affine invariant, thus the transformed images can be directly used for stereo matching. Any existing stereo algorithms can be directly used with the transformed images to improve reconstruction accuracy for low-texture regions. Results on real indoor and outdoor images demonstrate the effectiveness of the proposed transform for matching low-texture regions, keypoint detection, and description for low-texture scenes. Our experimental results on Middlebury images also demonstrate the robustness of our transform for highly textured scenes. The proposed transform has a great advantage, its low computational complexity. It was tested on a MacBook Air laptop computer with a 1.8 GHz Core i7 processor, with a speed of about 9 frames per second for a video graphics array-sized image. PMID:22801509

  4. Thin-Film Power Transformers

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.

    1995-01-01

    Transformer core made of thin layers of insulating material interspersed with thin layers of ferromagnetic material. Flux-linking conductors made of thinner nonferromagnetic-conductor/insulator multilayers wrapped around core. Transformers have geometric features finer than those of transformers made in customary way by machining and mechanical pressing. In addition, some thin-film materials exhibit magnetic-flux-carrying capabilities superior to those of customary bulk transformer materials. Suitable for low-cost, high-yield mass production.

  5. Characterization of the low-temperature triplet state of chlorophyll in photosystem II core complexes: Application of phosphorescence measurements and Fourier transform infrared spectroscopy.

    PubMed

    Zabelin, Alexey A; Neverov, Konstantin V; Krasnovsky, Alexander A; Shkuropatova, Valentina A; Shuvalov, Vladimir A; Shkuropatov, Anatoly Ya

    2016-06-01

    Phosphorescence measurements at 77 K and light-induced FTIR difference spectroscopy at 95 K were applied to study of the triplet state of chlorophyll a ((3)Chl) in photosystem II (PSII) core complexes isolated from spinach. Using both methods, (3)Chl was observed in the core preparations with doubly reduced primary quinone acceptor QA. The spectral parameters of Chl phosphorescence resemble those in the isolated PSII reaction centers (RCs). The main spectral maximum and the lifetime of the phosphorescence corresponded to 955±1 nm and of 1.65±0.05 ms respectively; in the excitation spectrum, the absorption maxima of all core complex pigments (Chl, pheophytin a (Pheo), and β-carotene) were observed. The differential signal at 1667(-)/1628(+)cm(-1) reflecting a downshift of the stretching frequency of the 13(1)-keto C=O group of Chl was found to dominate in the triplet-minus-singlet FTIR difference spectrum of core complexes. Based on FTIR results and literature data, it is proposed that (3)Chl is mostly localized on the accessory chlorophyll that is in triplet equilibrium with P680. Analysis of the data suggests that the Chl triplet state responsible for the phosphorescence and the FTIR difference spectrum is mainly generated due to charge recombination in the reaction center radical pair P680(+)PheoD1(-), and the energy and temporal parameters of this triplet state as well as the molecular environment and interactions of the triplet-bearing Chl molecule are similar in the PSII core complexes and isolated PSII RCs. PMID:27040752

  6. Reading Research on Core Values, Christian Ethos and School Transformation at England's Most Improved Academy: A Reply to Bragg, Allington, Simmons and Jones

    ERIC Educational Resources Information Center

    Pike, Mark A.

    2011-01-01

    This article presents the author's reply to the comments of Bragg, Allington, Simmons and Jones to his article "Transaction and transformation at Trinity" (Pike, 2010) wherein he reported a case study of Trinity Academy, which serves a former mining community and social priority area near Doncaster in South Yorkshire. In 2008, just before the…

  7. All Metal Iron Core For A Low Aspect Ratio Tokamak

    SciTech Connect

    D.A. Gates, C. Jun, I. Zatz, A. Zolfaghari

    2010-06-02

    A novel concept for incorporating a iron core transformer within a axisymmetric toroidal plasma containment device with a high neutron flux is described. This design enables conceptual design of low aspect ratio devices which employ standard transformer-driven plasma startup by using all-metal high resistance separators between the toroidal field windings. This design avoids the inherent problems of a multiturn air core transformer which will inevitably suffer from strong neutron bombardment and hence lose the integrity of its insulation, both through long term material degradation and short term neutron- induced conductivity.. A full 3-dimensional model of the concept has been developed within the MAXWELL program and the resultant loop voltage calculated. The utility of the result is found to be dependent on the resistivity of the high resistance separators. Useful loop voltage time histories have been obtained using achievable resistivities.

  8. Comparison of the efficacy of a forced-air warming system and circulating-water mattress on core temperature and post-anesthesia shivering in elderly patients undergoing total knee arthroplasty under spinal anesthesia

    PubMed Central

    Lee, Kyu Chang; Lee, Myeong Jong; Kim, Mi-Na; Kim, Ji-Sub; Lee, Won Sang; Lee, Jung Hwa

    2014-01-01

    Background In the present study, we compared changes in body temperature and the occurrence of shivering in elderly patients undergoing total knee arthroplasty under spinal anesthesia during warming with either a forced-air warming system or a circulating-water mattress. Methods Forty-six patients were randomly assigned to either the forced-air warming system (N = 23) or circulating-water mattress (N = 23) group. Core temperature was recorded using measurements at the tympanic membrane and rectum. In addition, the incidence and intensity of post-anesthesia shivering and verbal analogue score for thermal comfort were simultaneously assessed. Results Core temperature outcomes did not differ between the groups. The incidence (13.0 vs 43.5%, P < 0.05) and intensity (20/2/1/0/0 vs 13/5/3/2/0, P < 0.05) of post-anesthesia shivering was significantly lower in the forced-air system group than in the circulating-water mattress group. Conclusions The circulating-water mattress was as effective as the forced-air warming system for maintaining body temperature. However, the forced-air warming system was superior to the circulating-water mattress in reducing the incidence of post-anesthesia shivering. PMID:24910726

  9. Fixture for winding transformers

    NASA Technical Reports Server (NTRS)

    Mclyman, M. T.

    1980-01-01

    Bench-mounted fixture assists operator in winding toroid-shaped transformer cores. Toroid is rigidly held in place as wires are looped around. Arrangement frees both hands for rapid winding and untangling of wires that occurs when core is hand held.

  10. Effects of isolobal heteroatoms in divanadium-substituted γ-Keggin-type polyoxometalates on (OV)2(μ-OH)2 diamond and (OV)2(μ-O) core structures and the transformation.

    PubMed

    Uehara, Kazuhiro; Taketsugu, Tatsuya; Yonehara, Kazuhiro; Mizuno, Noritaka

    2013-01-18

    Effects of isolobal heteroatoms in divanadium-substituted γ-Keggin-type polyoxometalates, (TBA)(4)[γ-XV(2)W(10)O(38)(μ-OH)(2)] 1(X) and (TBA)(4)[γ-XV(2)W(10)O(38)(μ-O)] 2(X) (where X = Ge or Si), on (OV)(2)(μ-OH)(2) and (OV)(2)(μ-O) core structures and transformations from 2(X) to 1(X) have been investigated. X-ray crystallography of 1(X) and 2(X) reveals that larger Ge (covalent radius 1.22 Å; covalent radius of Si 1.11 Å) induces (a) expansion of (OV)(2)(μ-OH)(2) and (OV)(2)(μ-O) cores, (b) expansion of lacunary sites, and (c) deep location of divanadium cores inside their lacunary sites. Density functional theory (DFT) calculations for anionic moieties of 1(X) and 2(X) reveal that energy levels of the highest occupied molecular orbital (HOMO)-1 in 1(Ge) and HOMO in 2(Ge) are lower than those in 1(Si) and 2(Si), respectively, because of smaller contribution of p(z) orbitals of oxygen atoms in 1(Ge) and 2(Ge), which would result from shorter V···O(-Ge) distances. Compound 2(Ge) reacts with water vapor to form (TBA)(4)[γ-GeV(2)W(10)O(38)(μ-OH)(2)] 1'(Ge) via a crystal-to-crystal transformation, and the water dissociation proceeds heterolytically. DFT calculations reveal that the reaction proceeds through (1) coordination of water on a coordinatively unsaturated site of vanadium in the lowest unoccupied molecular orbital (LUMO), followed by (2) proton transfer to the bridging oxo moiety. The order is different from that in 2(Si), which would result from the lower energy level of HOMO of 2(Ge) (i.e., lower nucleophilicity toward a proton of water) than that of 2(Si). PMID:23301537

  11. Core assembly storage structure

    DOEpatents

    Jones, Jr., Charles E.; Brunings, Jay E.

    1988-01-01

    A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

  12. Biomolecular Markers within the Core Axis of Aging and Particulate Air Pollution Exposure in the Elderly: A Cross-Sectional Study

    PubMed Central

    Pieters, Nicky; Janssen, Bram G.; Dewitte, Harrie; Cox, Bianca; Cuypers, Ann; Lefebvre, Wouter; Smeets, Karen; Vanpoucke, Charlotte; Plusquin, Michelle; Nawrot, Tim S.

    2015-01-01

    .5. Citation: Pieters N, Janssen BG, Dewitte H, Cox B, Cuypers A, Lefebvre W, Smeets K, Vanpoucke C, Plusquin M, Nawrot TS. 2016. Biomolecular markers within the core axis of aging and particulate air pollution exposure in the elderly: a cross-sectional study. Environ Health Perspect 124:943–950; http://dx.doi.org/10.1289/ehp.1509728 PMID:26672058

  13. Surface-initiated atom transfer radical polymerization-induced transformation of selenium nanowires into copper selenide@polystyrene core-shell nanowires.

    PubMed

    Wang, Michael C P; Gates, Byron D

    2013-10-01

    This Article reports the first preparation of cuprous and cupric selenide nanowires coated with a ∼5 nm thick sheath of polystyrene (copper selenide@polystyrene). These hybrid nanostructures are prepared by the transformation of selenium nanowires in a one-pot reaction, which is performed under ambient conditions. The composition, purity, and crystallinity of the copper selenide@polystyrene products were assessed by scanning transmission electron microscopy, electron energy-loss spectroscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy techniques. We determined that the single crystalline selenium nanowires are converted into polycrystalline copper selenide@polystyrene nanowires containing both cuprous selenide and cupric selenide. The product is purified through the selective removal of residual, non-transformed selenium nanowires by performing thermal evaporation below the decomposition temperature of these copper selenides. Powder X-ray diffraction of the purified copper selenide nanowires@polystyrene identified the presence of hexagonal, cubic, and orthorhombic phases of copper selenide. These purified cuprous and cupric selenide@polystyrene nanowires have an indirect bandgap of 1.44 eV, as determined by UV-vis absorption spectroscopy. This new synthesis of polymer-encapsulated nanoscale materials may provide a method for preparing other complex hybrid nanostructures. PMID:24041404

  14. Modal cutoff in rare-earth-doped photonic crystal fibers with multi-layer air-holes missing in the core

    NASA Astrophysics Data System (ADS)

    Zhao, Xing-tao; Zheng, Yi; Liu, Xiao-xu; Li, Shu-guang; Han, Ying; Hou, Zhi-yun; Wang, Na; Hou, Lan-tian

    2013-05-01

    The various mode effective indices of the doped photonic crystal fibers (PCFs) are compared, the mode field distributions of the fundamental mode and the second-order mode are analyzed, and the single-mode condition is presented. The mode effective indices of large-core doped PCFs with different core indices and structure parameters are simulated by the finite element method (FEM). The relations of the core index with the fiber structure parameters of pitch, hole-to-pitch ratio and core diameter are obtained for single-mode propagation. In the design and fabrication of the doped PCF, we can adjust the core index and fiber structure parameters to achieve large mode area and single-mode propagation.

  15. ‘Building Core Knowledge - Reconstructing Earth History’: Transforming Undergraduate Instruction by Bringing Ocean Drilling Science on Earth History and Global Climate Change into the Classroom (Invited)

    NASA Astrophysics Data System (ADS)

    St. John, K.; Leckie, R. M.; Jones, M. H.; Pound, K. S.; Pyle, E.; Krissek, L. A.

    2009-12-01

    This NSF-funded, Phase 1 CCLI project effectively integrates scientific ocean drilling data and research (DSDP-ODP-IODP-ANDRILL) with education. We have developed, and are currently testing, a suite of data-rich inquiry-based classroom learning materials based on sediment core archives. These materials are suitable for use in introductory geoscience courses that serve general education students, early geoscience majors, and pre-service teachers. 'Science made accessible' is the essence of this goal. Our team consists of research and education specialists from institutions ranging from R1 research to public liberal arts to community college. We address relevant and timely ‘Big Ideas’ with foundational geoscience concepts and climate change case studies, as well transferable skills valued in professional settings. The exercises are divided into separate but inter-related modules including: introduction to cores, seafloor sediments, microfossils and biostratigraphy, paleomagnetism and magnetostratigraphy, climate rhythms, oxygen-isotope changes in the Cenozoic, past Arctic and Antarctic climates, drill site selection, interpreting Arctic and Antarctic sediment cores, onset of Northern Hemisphere glaciation, onset of Antarctic glaciation, and the Paleocene-Eocene Thermal Maximum. Each module has several parts, and each is designed to be used in the classroom, laboratory, or assigned as homework. All exercises utilize authentic data. Students work with scientific uncertainty, practice quantitative and problem-solving skills, and expand their basic geologic and geographic knowledge. Students have the opportunity to work individually and in groups, evaluate real-world problems, and formulate hypotheses. Initial exercises in each module are useful to introduce a topic, gauge prior knowledge, and flag possible areas of student misconception. Comprehensive instructor guides provide essential background information, detailed answer keys, and alternative implementation

  16. Analysis of a transformer-less, multi-level DC-DC converter for HVDC operation

    SciTech Connect

    Karady, G.G.; Devarajan, S.

    1998-12-31

    HVDC systems require DC step up and DC step down units. The traditional approach is the application of twelve-pulse thyristor bridges with transformers. The developments of fast switching IGBT devices permit the development of transformer-less, multi-level converters. A multi-level circuit was suggested by Limpaecher. This paper presents a detailed simulation of the proposed circuit together with the analysis of its performance. The converter consists of a set of capacitors, air core inductors and solid state switches arranged in a ladder network. In the step-up mode, the closing of solid state switches resonantly charges the capacitors in parallel through an air-cored inductor. Then solid state switches resonantly charges the capacitors in parallel through an air-cored inductor. Then solid state switches connect the capacitors in series and discharge them through an air-core inductor to the load. In the step-down mode the capacitors are charged in series and discharged in parallel. The circuit has three modes of operation in each cycle: charge, inversion, and discharge. The circuit operation is analyzed in each mode using SPICE simulations. The selection of the components is discussed and output voltage regulation is analyzed. The results show that the proposed circuit promises significant reduction of losses, because of the zero current switching. The investment cost is reduced because of the elimination of transformers.

  17. Enhancing Understanding of Transformation Matrices

    ERIC Educational Resources Information Center

    Dick, Jonathan; Childrey, Maria

    2012-01-01

    With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…

  18. Facile One-pot Transformation of Iron Oxides from Fe2O3 Nanoparticles to Nanostructured Fe3O4@C Core-Shell Composites via Combustion Waves.

    PubMed

    Shin, Jungho; Lee, Kang Yeol; Yeo, Taehan; Choi, Wonjoon

    2016-01-01

    The development of a low-cost, fast, and large-scale process for the synthesis and manipulation of nanostructured metal oxides is essential for incorporating materials with diverse practical applications. Herein, we present a facile one-pot synthesis method using combustion waves that simultaneously achieves fast reduction and direct formation of carbon coating layers on metal oxide nanostructures. Hybrid composites of Fe2O3 nanoparticles and nitrocellulose on the cm scale were fabricated by a wet impregnation process. We demonstrated that self-propagating combustion waves along interfacial boundaries between the surface of the metal oxide and the chemical fuels enabled the release of oxygen from Fe2O3. This accelerated reaction directly transformed Fe2O3 into Fe3O4 nanostructures. The distinctive color change from reddish-brown Fe2O3 to dark-gray Fe3O4 confirmed the transition of oxidation states and the change in the fundamental properties of the material. Furthermore, it simultaneously formed carbon layers of 5-20 nm thickness coating the surfaces of the resulting Fe3O4 nanoparticles, which may aid in maintaining the nanostructures and improving the conductivity of the composites. This newly developed use of combustion waves in hybridized nanostructures may permit the precise manipulation of the chemical compositions of other metal oxide nanostructures, as well as the formation of organic/inorganic hybrid nanostructures. PMID:26902260

  19. Facile One-pot Transformation of Iron Oxides from Fe2O3 Nanoparticles to Nanostructured Fe3O4@C Core-Shell Composites via Combustion Waves

    PubMed Central

    Shin, Jungho; Lee, Kang Yeol; Yeo, Taehan; Choi, Wonjoon

    2016-01-01

    The development of a low-cost, fast, and large-scale process for the synthesis and manipulation of nanostructured metal oxides is essential for incorporating materials with diverse practical applications. Herein, we present a facile one-pot synthesis method using combustion waves that simultaneously achieves fast reduction and direct formation of carbon coating layers on metal oxide nanostructures. Hybrid composites of Fe2O3 nanoparticles and nitrocellulose on the cm scale were fabricated by a wet impregnation process. We demonstrated that self-propagating combustion waves along interfacial boundaries between the surface of the metal oxide and the chemical fuels enabled the release of oxygen from Fe2O3. This accelerated reaction directly transformed Fe2O3 into Fe3O4 nanostructures. The distinctive color change from reddish-brown Fe2O3 to dark-gray Fe3O4 confirmed the transition of oxidation states and the change in the fundamental properties of the material. Furthermore, it simultaneously formed carbon layers of 5–20 nm thickness coating the surfaces of the resulting Fe3O4 nanoparticles, which may aid in maintaining the nanostructures and improving the conductivity of the composites. This newly developed use of combustion waves in hybridized nanostructures may permit the precise manipulation of the chemical compositions of other metal oxide nanostructures, as well as the formation of organic/inorganic hybrid nanostructures. PMID:26902260

  20. Facile One-pot Transformation of Iron Oxides from Fe2O3 Nanoparticles to Nanostructured Fe3O4@C Core-Shell Composites via Combustion Waves

    NASA Astrophysics Data System (ADS)

    Shin, Jungho; Lee, Kang Yeol; Yeo, Taehan; Choi, Wonjoon

    2016-02-01

    The development of a low-cost, fast, and large-scale process for the synthesis and manipulation of nanostructured metal oxides is essential for incorporating materials with diverse practical applications. Herein, we present a facile one-pot synthesis method using combustion waves that simultaneously achieves fast reduction and direct formation of carbon coating layers on metal oxide nanostructures. Hybrid composites of Fe2O3 nanoparticles and nitrocellulose on the cm scale were fabricated by a wet impregnation process. We demonstrated that self-propagating combustion waves along interfacial boundaries between the surface of the metal oxide and the chemical fuels enabled the release of oxygen from Fe2O3. This accelerated reaction directly transformed Fe2O3 into Fe3O4 nanostructures. The distinctive color change from reddish-brown Fe2O3 to dark-gray Fe3O4 confirmed the transition of oxidation states and the change in the fundamental properties of the material. Furthermore, it simultaneously formed carbon layers of 5-20 nm thickness coating the surfaces of the resulting Fe3O4 nanoparticles, which may aid in maintaining the nanostructures and improving the conductivity of the composites. This newly developed use of combustion waves in hybridized nanostructures may permit the precise manipulation of the chemical compositions of other metal oxide nanostructures, as well as the formation of organic/inorganic hybrid nanostructures.

  1. Magnetic materials selection for static inverter and converter transformers

    NASA Technical Reports Server (NTRS)

    Mclyman, C. W. T.

    1971-01-01

    Different magnetic alloys best suited for high-frequency and high-efficiency applications were comparatively investigated together with an investigation of each alloy's inherent characteristics. One of the characteristics in magnetic materials deterimental in transformer design is the residual flux density, which can be additive on turn-on and cause the transformer to saturate. Investigation of this problem led to the design of a transformer with a very low residual flux. Tests were performed to determine the dc and ac magnetic properties at 2400 Hz using square-wave excitation. These tests were performed on uncut cores, which were then cut for comparison of the gapped and ungapped magnetic properties. The optimum transformer was found to be that with the lowest residual flux and a small amount of air gap in the magnetic material. The data obtained from these tests are described, and the potential uses for the materials are discussed.

  2. Magnetically Controlled Variable Transformer

    NASA Technical Reports Server (NTRS)

    Kleiner, Charles T.

    1994-01-01

    Improved variable-transformer circuit, output voltage and current of which controlled by use of relatively small current supplied at relatively low power to control windings on its magnetic cores. Transformer circuits of this type called "magnetic amplifiers" because ratio between controlled output power and power driving control current of such circuit large. This ratio - power gain - can be as large as 100 in present circuit. Variable-transformer circuit offers advantages of efficiency, safety, and controllability over some prior variable-transformer circuits.

  3. Accelerating the prediction-based lower triangular transform for data compression using Intel MIC

    NASA Astrophysics Data System (ADS)

    Wei, Shih-Chieh; Huang, Bormin

    2015-10-01

    With the same decorrelation and coding gain capabilities as the Karhunen-Loeve transform, the prediction-based lower triangular transform (PLT) can apply its perfect reconstruction property for lossless compression of ultraspectral sounder data. As the compression process requires computation of the covariance matrix, the LDU decomposition, and the transform kernel and coefficient matrices, it will be beneficial to introduce parallel processing technology in the PLT implementation. In this work, the recent Intel Many Integrated Core (MIC) architecture will be used which can exploit up to 60 cores with 4 hardware threads per core. Both threading and vectorization techniques will be explored for performance improvement. In our experiment, the total processing time of an AIRS granule can have a speedup of ~4.6x. With the offload mode, the MIC architecture provides a convenient and efficient tool for parallelization of the PLT compression scheme.

  4. Muscovite-Dehydration Melting: A Textural Study of a Key Reaction in Transforming Continental Margin Strata Into a Migmatitic Orogenic Core

    NASA Astrophysics Data System (ADS)

    Dyck, B. J.; St Onge, M. R.; Waters, D. J.; Searle, M. P.

    2015-12-01

    Metamorphosed continental margin sedimentary sequences, which comprise the dominant tectonostratigraphic assemblage exposed in orogenic hinterlands, are crucial to understanding the architecture and evolution of collisional mountain belts. This study explores the textural effect of anatexis in amphibolite-grade conditions and documents the mineral growth mechanisms that control nucleation and growth of K-feldspar, sillimanite and silicate melt. The constrained textural evolution follows four stages: 1) Nucleation - K-feldspar is documented to nucleate epitaxially on isomorphic plagioclase in quartzofeldspathic (psammitic) domains, whereas sillimanite nucleates in the Al-rich (pelitic) domain, initially on [001] mica planes. The first melt forms at the site of muscovite breakdown. 2) Chemically driven growth - In the quartzofeldspathic domain, K-feldspar progressively replaces plagioclase by a K+ - Na+ cation transfer reaction, driven by the freeing of muscovite-bound K+ during breakdown of the mica. Sillimanite forms intergrowths with the remaining hydrous melt components, contained initially in ovoid clots. 3) Merge and coarsening - With an increase in pressure, melt and sillimanite migrate away from clots along grain boundaries. A melt threshold is reached once the grain-boundary network is wetted by melt, increasing the length-scale of diffusion, resulting in grain boundary migration and grain-size coarsening. The melt threshold denotes the transition to an open-system on the lithology scale, where melt is a transient phase. 4) Residual melt crystallization - Residual melt crystallizes preferentially on existing peritectic grains as anatectic quartz, plagioclase, and K-feldspar. As the system cools and closes, grain growth forces melt into the intersections of grain-boundaries, recognized as irregular shaped melt films, or as intergrowths of the volatile-rich phases (i.e. Tur-Ms-Ap). In the Himalayan metamorphic core these processes result in the formation of

  5. The investigation of a compact auto-connected wire-wrapped pulsed transformer.

    PubMed

    Wang, Yuwei; Zhang, Jiande; Chen, Dongqun; Cao, Shengguang; Li, Da; Zhang, Tianyang

    2012-05-01

    For the power conditioning circuit used to deliver power efficiently from flux compression generator (FCG) to the load with high impedance, an air-cored and wire-wrapped transformer convenient in coaxial connection to the other parts is investigated. To reduce the size and enhance the performance, an auto-connection is adopted. A fast and simple model is used to calculate the electrical parameters of the transformer. To evaluate the high voltage capability, the voltages across turns and the electric field distribution in the transformer are investigated. The calculated and the measured electrical parameters of the transformer show good agreements. And the safe operating voltage is predicted to exceed 500 kV. In the preliminary experiments, the transformer is tested in a power conditioning circuit with a capacitive power supply. It is demonstrated that the output voltage of the transformer reaches -342 kV under the input voltage of -81 kV. PMID:22667636

  6. 134. VIEW OF TRANSFORMER CABINETS ON NORTH SIDE OF TRANSFORMER ...

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

    134. VIEW OF TRANSFORMER CABINETS ON NORTH SIDE OF TRANSFORMER ROOM (212), LSB (BLDG. 751), FACING SOUTH. POWER PANEL B AT EAST SIDE OF TRANSFORMER ROOM (212), FACING WEST, AT RIGHT IN PHOTOGRAPH. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  7. Technical report series on global modeling and data assimilation. Volume 5: Documentation of the AIRES/GEOS dynamical core, version 2

    NASA Technical Reports Server (NTRS)

    Suarez, Max J. (Editor); Takacs, Lawrence L.

    1995-01-01

    A detailed description of the numerical formulation of Version 2 of the ARIES/GEOS 'dynamical core' is presented. This code is a nearly 'plug-compatible' dynamics for use in atmospheric general circulation models (GCMs). It is a finite difference model on a staggered latitude-longitude C-grid. It uses second-order differences for all terms except the advection of vorticity by the rotation part of the flow, which is done at fourth-order accuracy. This dynamical core is currently being used in the climate (ARIES) and data assimilation (GEOS) GCMs at Goddard.

  8. Series Transmission Line Transformer

    DOEpatents

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  9. EXPOSURE ASSESSMENT FACILITY CORE

    EPA Science Inventory

    The Exposure Assessment Facility Core will continue to collect environmental measures including personal and indoor air monitoring and repeat collection of dust samples from the home and biologic measures including urine and blood samples collected from the mother during pregn...

  10. Monte Carlo simulations of electron lateral distributions in the core region of 10(13) - 10(16) eV air showers

    NASA Technical Reports Server (NTRS)

    Ash, A. G.

    1985-01-01

    This paper contains details of computer models of shower development which have been used to investigate the experimental data on shower cores observed in the Leeds 35 sq m and Sacramento Peak (New Mexico) 20 sq m arrays of current limited spark (discharge) chambers. The simulations include predictions for primaries ranging from protons to iron nuclei (with heavy nuclei treated using both superposition and fragmentation models).

  11. Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography

    NASA Astrophysics Data System (ADS)

    Bae, Chang-Jun

    Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to

  12. Transformer design tradeoffs

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1976-01-01

    Material was presented to assist transformer designers in the transition from long-used English units to the less familiar metric equivalents. A coordination between the area product numbers ap (product of window and core cross-section areas) and current density J was developed for a given regulation and temperature rise. Straight-line relationships for Ap and Volume, Ap and surface area At and, Ap and weight were developed. These relationships can now be used as new tools to simplify and standardize the process of transformer design. They also made it possible to design transformers of small bulk and volume or to optimize efficiency.

  13. Computerized toroidal transformer design

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Computer program designs transformers which have one primary /center tap permissible/ and up to 20 untapped secondaries, and which can handle up to 500 V across any one winding. Computer determines total secondary power, core type, primary turns, secondary turns, and wire sizes for primary and secondary windings.

  14. Particle distributions in approximately 10(13) - 10(16) eV air shower cores at mountain altitude and comparison with Monte Carlo simulations

    NASA Technical Reports Server (NTRS)

    Ash, A. G.

    1985-01-01

    Photographs of 521 shower cores in an array of current-limited spark (discharge) chambers at Sacramento Peak (2900m above sea level, 730 g /sq cm.), New Mexico, U.S.A., have been analyzed and the results compared with similar data from Leeds (80m above sea level, 1020 g sq cm.). It was found that the central density differential spectrum is consistent with a power law index of -2 up to approx. 1500/sq m where it steepens, and that shower cores become flatter on average with increasing size. Scaling model predictions for proton primaries with a approx E sup -2.71 energy spectrum account well for the altitude dependence of the data at lower densities. However, deviations at higher densities indicate a change in hadron interaction characteristics between approx few x 10 to the 14th power and 10 to the 15th power eV primary energy causing particles close to the shower axis to be spread further out.

  15. CORE SATURATION BLOCKING OSCILLATOR

    DOEpatents

    Spinrad, R.J.

    1961-10-17

    A blocking oscillator which relies on core saturation regulation to control the output pulse width is described. In this arrangement an external magnetic loop is provided in which a saturable portion forms the core of a feedback transformer used with the thermionic or semi-conductor active element. A first stationary magnetic loop establishes a level of flux through the saturation portion of the loop. A second adjustable magnet moves the flux level to select a saturation point giving the desired output pulse width. (AEC)

  16. First steps toward development of a stable isotope forward model for tropical ice cores: cold air incursions and snow days at Quelccaya Ice Cap, Peru

    NASA Astrophysics Data System (ADS)

    Hurley, J. V.; Vuille, M. F.; Hardy, D. R.; Burns, S. J.

    2014-12-01

    We are working towards a forward-model reconstruction of the South American Summer Monsoon (SASM) for the last millennium from the Quelccaya Ice Cap (QIC) d18O record. QIC receives precipitation almost exclusively during the SASM season. Initial efforts focus on dynamics that yield precipitation at this receding tropical ice cap, and how they relate to the hydrogen and oxygen stable isotopes. We present over a decade of daily snow-height change observations from the summit of QIC. Accumulation of snow (~2 m yr-1) at the summit occurs October through April, peaking in December. Net monthly snow-height change is negative May through September, though positive snow height change days do occur throughout the year. Snow height change time-series are used to develop d18O age-models for annual snow collected in vertical profiles near the summit of QIC since 2003. Snow d18O decreases during austral summer from about -17 to -24 per mil VSMOW. Post-depositional alteration of late summer snow during austral winter elevates d18O from about -24 to about -15 per mil VSMOW. Timing of 90thpercentile positive snow-height change events at QIC corresponds with regional precipitation and outgoing longwave radiation (OLR) anomalies that are dynamically triggered by cold air incursions propagating from the midlatitudes east of the Andes into the Amazon Basin. Precipitation and OLR anomalies migrate northwest in about 2-3 days from near Rio de la Plata to central Peru. The convective anomalies are the result of southerly horizontal wind anomalies in the lower troposphere that advect cold extratropical air equatorward. Composite analysis of satellite measurements shows that cold air incursions are associated with negative water vapor dD (~ -40 per mil) anomalies at QIC. We expect that snow stable isotope values from QIC are thus not only records of the deep overturning component of the monsoon circulation but also of synoptic scale monsoon disturbances. Cold air incursions into the South

  17. Carbon-Coated Core-Shell Fe-Cu Nanoparticles as Highly Active and Durable Electrocatalysts for a Zn-Air Battery.

    PubMed

    Nam, Gyutae; Park, Joohyuk; Choi, Min; Oh, Pilgun; Park, Suhyeon; Kim, Min Gyu; Park, Noejung; Cho, Jaephil; Lee, Jang-Soo

    2015-06-23

    Understanding the interaction between a catalyst and oxygen has been a key step in designing better electrocatalysts for the oxygen reduction reaction (ORR) as well as applying them in metal-air batteries and fuel cells. Alloying has been studied to finely tune the catalysts' electronic structures to afford proper binding affinities for oxygen. Herein, we synthesized a noble-metal-free and nanosized transition metal CuFe alloy encapsulated with a graphitic carbon shell as a highly efficient and durable electrocatalyst for the ORR in alkaline solution. Theoretical models and experimental results demonstrated that the CuFe alloy has a more moderate binding strength for oxygen molecules as well as the final product, OH(-), thus facilitating the oxygen reduction process. Furthermore, the nitrogen-doped graphitic carbon-coated layer, formed catalytically under the influence of iron, affords enhanced charge transfer during the oxygen reduction process and superior durability. These benefits were successfully confirmed by realizing the catalyst application in a mechanically rechargeable Zn-air battery. PMID:25967866

  18. Cold-air annular-cascade investigation of aerodynamic performance of core-engine-cooled turbine vanes. 1: Solid-vane performance and facility description

    NASA Technical Reports Server (NTRS)

    Goldman, L. J.; Mclallin, K. L.

    1975-01-01

    The aerodynamic performance of a solid (uncooled) version of a core engine cooled stator vane was experimentally determined in a full-annular cascade, where three-dimensional effects could be obtained. The solid vane, which serves as a basis for comparison with subsequent cooled tests, was tested over a range of aftermixed critical velocity ratios of 0.57 to 0.90. Overall vane aftermixed efficiencies were obtained over this critical velocity ratio range and compared with results from a two-dimensional cascade. The variation in vane efficiency and aftermixed flow conditions with circumferential and radial position were obtained and compared with design values. Vane surface static-pressure distributions were also measured and compared with theoretical results.

  19. Core Noise Reduction

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

  20. Simplifying the ELA Common Core; Demystifying Curriculum

    ERIC Educational Resources Information Center

    Schmoker, Mike; Jago, Carol

    2013-01-01

    The English Language Arts (ELA) Common Core State Standards ([CCSS], 2010) could have a transformational effect on American education. Though the process seems daunting, one can begin immediately integrating the essence of the ELA Common Core in every subject area. This article shows how one could implement the Common Core and create coherent,…

  1. Design of a circular photonic crystal fiber with flattened chromatic dispersion using a defected core and selectively reduced air holes: Application to supercontinuum generation at 1.55 μm

    NASA Astrophysics Data System (ADS)

    Medjouri, Abdelkader; Simohamed, Lotfy Mokhtar; Ziane, Omar; Boudrioua, Azzedine; Becer, Zoubir

    2015-08-01

    In this paper, we present and numerically investigate a new and simple design of Circular Lattice Photonic Crystal Fiber (CL-PCF) with near zero ultra-flattened chromatic dispersion. The near zero dispersion is obtained by introducing a defect into the solid core and the dispersion flatness is achieved by appropriately reducing the diameter of the core-neighboring air holes ring. Simulations are performed by using the finite-difference frequency-domain (FDFD) method combined with the perfectly matched layer (PML) boundary condition. Results show that an ultra-flattened chromatic dispersion as small as ±0.66 ps/nm km is obtained over a broad band of 400 nm with high nonlinearity and ultra-low confinement loss. Furthermore, the supercontinuum (SC) generation over a short length of the proposed CL-PCF is numerically investigated. Results indicate that flat SC spectrum with a Full Width at Half Maximum (FWHM) of 600 nm is achieved with 25 cm of fiber length.

  2. Core-Noise Research

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of core noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of core noise due to turbofan design trends; the need to understand and mitigate core-noise sources for high-efficiency small gas generators; and the current research activities in the core-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) core-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of core-noise sources and noise propagation through the engine core, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-core application. Core noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, core-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The

  3. Toroidal core winder

    DOEpatents

    Potthoff, Clifford M.

    1978-01-01

    The disclosure is directed to an apparatus for placing wire windings on a toroidal body, such as a transformer core, having an orifice in its center. The apparatus comprises a wire storage spool, a wire loop holding continuous belt maintained in a C-shaped loop by a belt supporting structure and provision for turning the belt to place and tighten loops of wire on a toroidal body, which is disposed within the gap of the C-shaped belt loop.

  4. Spacecraft transformer and inductor design

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1977-01-01

    The conversion process in spacecraft power electronics requires the use of magnetic components which frequently are the heaviest and bulkiest items in the conversion circuit. This handbook pertains to magnetic material selection, transformer and inductor design tradeoffs, transformer design, iron core dc inductor design, toroidal power core inductor design, window utilization factors, regulation, and temperature rise. Relationships are given which simplify and standardize the design of transformers and the analysis of the circuits in which they are used. The interactions of the various design parameters are also presented in simplified form so that tradeoffs and optimizations may easily be made.

  5. Air-Stable, Near- to Mid-Infrared Emitting Solids of PbTe/CdTe Core-Shell Colloidal quantum dots.

    PubMed

    Protesescu, Loredana; Zünd, Tanja; Bodnarchuk, Maryna I; Kovalenko, Maksym V

    2016-03-01

    Light emitters and detectors operating in the near- and mid-infrared spectral regions are important to many applications, such as telecommunications, high-resolution gas analysis, atmospheric pollution monitoring, medical diagnostics, and night vision. Various lead chalcogenides (binary, ternary, and quaternary alloys) in the form of quantum dots (QDs) or quantum wells provide narrow bandgap energies that cover the broad infrared region corresponding to wavelengths of 1-30 μm. Here, we report an inexpensive, all-solution-based synthesis strategy to thin-film solids consisting of 5-16 nm PbTe QDs encapsulated by CdTe shells. Colloidally synthesized PbTe QDs were first converted into core-shell PbTe/CdTe QDs, and then deposited as thin films. The subsequent fusion of the CdTe shells is achieved by ligand removal and annealing in the presence of CdCl2 . Contrary to highly unstable bare PbTe QDs, PbTe/CdTe QD solids exhibit bright and stable near- to mid-infrared emission at wavelengths of 1-3 μm, which is also retained upon prolonged storage at ambient conditions for one year. PMID:26676076

  6. DUBLIN CORE

    EPA Science Inventory

    The Dublin Core is a metadata element set intended to facilitate discovery of electronic resources. It was originally conceived for author-generated descriptions of Web resources, and the Dublin Core has attracted broad ranging international and interdisciplinary support. The cha...

  7. Core-Noise

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2010-01-01

    This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase

  8. Parameters of high-temperature superconducting transformers

    NASA Astrophysics Data System (ADS)

    Volkov, E. P.; Dzhafarov, E. A.

    2015-12-01

    Parameters of the high-temperature superconducting (HTSC) transformer with a core-type magnetic circuit and with coaxial and symmetrical interleaved windings made of the first-generation HTSC wire with a localized magnetic field are considered. The parameters of the most widespread core-type transformer with a coaxial HTSC winding are compared with those of a conventional transformer with a copper wire winding. Advantages of the HTSC transformers, such as reduction in the leakage inductive reactance and the HTSC winding's cross section, volume, and mass, as compared with the same parameters of conventional transformers with a copper wire winding are demonstrated. The efficiency of the HTSC transformers has proven to be determined predominantly by the core loss. In order to increase the efficiency of the HTSC transformer, it is proposed to use the amorphous electrical steel as the material of its magnetic circuit.

  9. Core Noise - Increasing Importance

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor

  10. A transformer of closely spaced pulsed waveforms

    NASA Technical Reports Server (NTRS)

    Niedra, J.

    1970-01-01

    Passive circuit, using diodes, transistors, and magnetic cores, transforms the voltage of repetitive positive or negative pulses. It combines a pulse transformer with switching devices to effect a resonant flux reset and can transform various pulsed waveforms that have a nonzero average value and are relatively cosely spaced in time.

  11. High voltage isolation transformer

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Ruitberg, A. P. (Inventor)

    1985-01-01

    A high voltage isolation transformer is provided with primary and secondary coils separated by discrete electrostatic shields from the surfaces of insulating spools on which the coils are wound. The electrostatic shields are formed by coatings of a compound with a low electrical conductivity which completely encase the coils and adhere to the surfaces of the insulating spools adjacent to the coils. Coatings of the compound also line axial bores of the spools, thereby forming electrostatic shields separating the spools from legs of a ferromagnetic core extending through the bores. The transformer is able to isolate a high constant potential applied to one of its coils, without the occurrence of sparking or corona, by coupling the coatings, lining the axial bores to the ferromagnetic core and by coupling one terminal of each coil to the respective coating encasing the coil.

  12. 24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES ...

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

    24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES FOR A BRASS GATE VALVE BODY MADE ON A CORE BOX, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  13. Towards high efficiency air-processed near-infrared responsive photovoltaics: bulk heterojunction solar cells based on PbS/CdS core-shell quantum dots and TiO2 nanorod arrays.

    PubMed

    Gonfa, Belete Atomsa; Kim, Mee Rahn; Delegan, Nazar; Tavares, Ana C; Izquierdo, Ricardo; Wu, Nianqiang; El Khakani, My Ali; Ma, Dongling

    2015-06-14

    Near infrared (NIR) PbS quantum dots (QDs) have attracted significant research interest in solar cell applications as they offer several advantages, such as tunable band gaps, capability of absorbing NIR photons, low cost solution processability and high potential for multiple exciton generation. Nonetheless, reports on solar cells based on NIR PbS/CdS core-shell QDs, which are in general more stable and better passivated than PbS QDs and thus more promising for solar cell applications, remain very rare. Herein we report high efficiency bulk heterojunction QD solar cells involving hydrothermally grown TiO2 nanorod arrays and PbS/CdS core-shell QDs processed in air (except for a device thermal annealing step) with a photoresponse extended to wavelengths >1200 nm and with a power conversion efficiency (PCE) as high as 4.43%. This efficiency was achieved by introducing a thin, sputter-deposited, uniform TiO2 seed layer to improve the interface between the TiO2 nanorod arrays and the front electrode, by optimizing TiO2 nanorod length and by conducting QD annealing treatment to enhance charge carrier transport. It was found that the effect of the seed layer became more obvious when the TiO2 nanorods were longer. Although photocurrent did not change much, both open circuit voltage and fill factor clearly changed with TiO2 nanorod length. This was mainly attributed to the variation of charge transport and recombination processes, as evidenced by series and shunt resistance studies. The optimal PCE was obtained at the nanorod length of ∼450 nm. Annealing is shown to further increase the PCE by ∼18%, because of the improvement of charge carrier transport in the devices as evidenced by considerably increased photocurrent. Our results clearly demonstrate the potential of the PbS/CdS core-shell QDs for the achievement of high PCE, solution processable and NIR responsive QD solar cells. PMID:25975363

  14. Coupling between core and cladding modes in a helical core fiber with large core offset

    NASA Astrophysics Data System (ADS)

    Napiorkowski, Maciej; Urbanczyk, Waclaw

    2016-05-01

    We analyzed the effect of resonant coupling between core and cladding modes in a helical core fiber with large core offset using the fully vectorial method based on the transformation optics formalism. Our study revealed that the resonant couplings to lower order cladding modes predicted by perturbative methods and observed experimentally in fibers with small core offsets are in fact prohibited for larger core offsets. This effect is related to the lack of phase matching caused by elongation of the optical path of the fundamental modes in the helical core. Moreover, strong couplings to the cladding modes of the azimuthal modal number much higher than predicted by perturbative methods may be observed for large core offsets, as the core offset introduces higher order angular harmonics in the field distribution of the fundamental modes. Finally, in contrast to previous studies, we demonstrate the existence of spectrally broad polarization sensitive couplings to the cladding modes suggesting that helical core fibers with large core offsets may be used as broadband circular polarizers.

  15. Honeycomb Core Permeability Under Mechanical Loads

    NASA Technical Reports Server (NTRS)

    Glass, David E.; Raman, V. V.; Venkat, Venki S.; Sankaran, Sankara N.

    1997-01-01

    A method for characterizing the air permeability of sandwich core materials as a function of applied shear stress was developed. The core material for the test specimens was either Hexcel HRP-3/16-8.0 and or DuPont Korex-1/8-4.5 and was nominally one-half inch thick and six inches square. The facesheets where made of Hercules' AS4/8552 graphite/epoxy (Gr/Ep) composites and were nominally 0.059-in. thick. Cytec's Metalbond 1515-3M epoxy film adhesive was used for co-curing the facesheets to the core. The permeability of the specimens during both static (tension) and dynamic (reversed and non-reversed) shear loads were measured. The permeability was measured as the rate of air flow through the core from a circular 1-in2 area of the core exposed to an air pressure of 10.0 psig. In both the static and dynamic testing, the Korex core experienced sudden increases in core permeability corresponding to a core catastrophic failure, while the URP core experienced a gradual increase in the permeability prior to core failure. The Korex core failed at lower loads than the HRP core both in the transverse and ribbon directions.

  16. Magnetic materials selection for static inverter and converter transformers

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1973-01-01

    A program to study magnetic materials is described for use in spacecraft transformers used in static inverters, converters, and transformer-rectifier supplies. Different magnetic alloys best suited for high-frequency and high-efficiency applications were comparatively investigated together with an investigation of each alloy's inherent characteristics. The materials evaluated were the magnetic alloys: (1) 50% Ni, 50% Fe; (2) 79% Ni, 17% Fe, 4% Mo; (3) 48% Ni, 52% Fe; (4) 78% Ni, 17% Fe, 5% Mo; and (5) 3% Si, 97% Fe. Investigations led to the design of a transformer with a very low residual flux. Tests were performed to determine the dc and ac magnetic properties at 2400 Hz using square-wave excitation. These tests were performed on uncut cores, which were then cut for comparison of the gapped and ungapped magnetic properties. When the data of many transformers in many configurations were compiled the optimum transformer was found to be that with the lowest residual flux and a small amount of air gap in the magnetic material. The data obtained from these tests are described, and the potential uses for the materials are discussed.

  17. Core strengthening.

    PubMed

    Arendt, Elizabeth A

    2007-01-01

    Several recent studies have evaluated interventional techniques designed to reduce the risk of serious knee injuries, particularly noncontact anterior cruciate ligament injuries in female athletes. Maintenance of rotational control of the limb underneath the pelvis, especially in response to cutting and jumping activities, is a common goal in many training programs. Rotational control of the limb underneath the pelvis is mediated by a complex set of factors including the strength of the trunk muscles and the relationship between the core muscles. It is important to examine the interrelationship between lower extremity function and core stability. PMID:17472321

  18. DC-Compensated Current Transformer.

    PubMed

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

  19. Reading Transformation

    ERIC Educational Resources Information Center

    Reeves, Melinda

    2006-01-01

    The parents of students who attend Decatur High School thought that there was little hope of their kids going on to college. After a year or so in Decatur's reading program, their sons and daughters were both transformed and college bound. In this article, the author describes how Decatur was able to successfully transform their students. Seven…

  20. Examination of Applying Amorphous Rolled Core to Permanent Magnet Synchronous Motors

    NASA Astrophysics Data System (ADS)

    Amano, Hisato; Enomoto, Yuji; Ito, Motoya; Itabashi, Hiromitsu; Tanigawa, Sigeho; Masaki, Ryoso

    Amorphous alloy exhibits high permeability and extremely low iron loss compared to magnetic steel sheet. Therefore, it is expected to contribute to the efficiency improvement of electromagnetic application products such as motors, generators, and transformers. In this paper, we examined an axial-type motor that uses the rolled amorphous core as a stator core for the purpose of applying amorphous alloy to a motor for air-conditioning equipments. We propose the motor structure to use amorphous alloy as a rolled core without complicated processing, and the evaluation results of the trial motor clarified that this structure is able to meet the target motor efficiency of 85% under the conditions that the size of the motor is below φ100mm × 60mm and that ferrite magnets are used.

  1. Saturable inductor and transformer structures for magnetic pulse compression

    DOEpatents

    Birx, Daniel L.; Reginato, Louis L.

    1990-01-01

    Saturable inductor and transformer for magnetic compression of an electronic pulse, using a continuous electrical conductor looped several times around a tightly packed core of saturable inductor material.

  2. Triple transformation

    NASA Astrophysics Data System (ADS)

    Khan, Farrukh I.; Schinn, Dustin S.

    2013-08-01

    A new business plan that enables policy transformation and resource mobilization at the national and international level, while improving access to resources, will allow the Green Climate Fund to integrate development goals and action on climate change.

  3. Covariant Transform

    NASA Astrophysics Data System (ADS)

    Kisil, Vladimir V.

    2011-03-01

    Dedicated to the memory of Cora Sadosky The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable or vacuum vectors which are not admissible. Covariant transform extends an applicability of the popular wavelets construction to classic examples like the Hardy space H2, Banach spaces, covariant functional calculus and many others.

  4. High-Voltage Isolation Transformer

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Ruitberg, A. P.

    1985-01-01

    Arcing and field-included surface erosion reduced by electrostatic shields around windings and ferromagnetic core of 80-kilovolt isolation transformer. Fabricated from high-resistivity polyurethane-based material brushed on critical surfaces, shields maintained at approximately half potential difference of windings.

  5. Reduction/Transformation Operators

    SciTech Connect

    Bartlett, Roscoe A.

    2006-09-01

    RTOp (reduction/transformation operators) is a collection of C++ software that provides the basic mechanism for implementinig vector operations in a flexible and efficient manner. This is the main interface utilized by Thyra to allow for the specification of specific vector reduction and/or transformation operations. The RTOp package contains three different types of software. (a) a small number of interoperability interfaces. (b) support software including code for the parallel SPMD mode based on only Teuchos::Comm(and not MPl directly(, and (c) a library of pre-implemented RTOp subclasses for everything from simple AXPYs and norms, to more specialized vector operations. RTOp allows an algorithm developer to implement their own RTOp subclasses in a way that is independent from any specific serial, parallel, out-of-core or other type of vector implementation. RTOp is a required package by Thyra and MOOCHO. (c)

  6. Reduction/Transformation Operators

    2006-09-01

    RTOp (reduction/transformation operators) is a collection of C++ software that provides the basic mechanism for implementinig vector operations in a flexible and efficient manner. This is the main interface utilized by Thyra to allow for the specification of specific vector reduction and/or transformation operations. The RTOp package contains three different types of software. (a) a small number of interoperability interfaces. (b) support software including code for the parallel SPMD mode based on only Teuchos::Comm(and notmore » MPl directly(, and (c) a library of pre-implemented RTOp subclasses for everything from simple AXPYs and norms, to more specialized vector operations. RTOp allows an algorithm developer to implement their own RTOp subclasses in a way that is independent from any specific serial, parallel, out-of-core or other type of vector implementation. RTOp is a required package by Thyra and MOOCHO. (c)« less

  7. Non-linear transformer modeling and simulation

    SciTech Connect

    Archer, W.E.; Deveney, M.F.; Nagel, R.L.

    1994-08-01

    Transformers models for simulation with Pspice and Analogy`s Saber are being developed using experimental B-H Loop and network analyzer measurements. The models are evaluated for accuracy and convergence using several test circuits. Results are presented which demonstrate the effects on circuit performance from magnetic core losses eddy currents and mechanical stress on the magnetic cores.

  8. SHARP transformation

    NASA Astrophysics Data System (ADS)

    Wyatt, Stephan

    2004-08-01

    The U.S. Navy"s SHAred Reconnaissance Pod (SHARP) employs the Recon/Optical, Inc. (ROI) CA-279 dual spectral band (visible/IR) digital cameras operating from an F-18E/F aircraft to perform low-to-high altitude reconnaissance missions. SHARP has proven itself combat worthy, with a rapid transition from development to operational deployment culminating in a highly reliable and effective reconnaissance capability for joint forces operating in Operation Iraqi Freedom (OIF). The U.S. Navy"s intelligence, surveillance and reconnaissance (ISR) roadmap transforms the SHARP system from being solely an independent reconnaissance sensor to a node in the growing Joint ISR network. ROI and the U.S. Navy have combined their resources to ensure the system"s transformation continues to follow the ISR road map. Pre-planned product improvements (P3I) for the CA-270 camera systems will lead the way in that transformation.

  9. Split Coil Forms for Rotary Transformers

    NASA Technical Reports Server (NTRS)

    Mclyman, C. W. T.

    1982-01-01

    Split cores for rotor and stator windings of rotary transformer mounted around their respective coils (which are in bobbins) and cemented together. This arrangement simplifies winding of stator coil to go in a slot in inner diameter of stator coil. One practical application of rotary transformers fabricated according to this technique is for centrifuges, in which conventional sliprings are of uncertain reliability.

  10. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, ... a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  11. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  12. 32. Credit JTL. Exterior transformer bank; note lightning arrestors removed ...

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

    32. Credit JTL. Exterior transformer bank; note lightning arrestors removed from pad and smaller arrestors installed on transformers and in area near air switches. - Dam No. 4 Hydroelectric Plant, Potomac River, Martinsburg, Berkeley County, WV

  13. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers.

    PubMed

    Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

    2013-07-01

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class. PMID:23902112

  14. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers

    SciTech Connect

    Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

    2013-07-15

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class.

  15. Transformation Time

    ERIC Educational Resources Information Center

    Berry, John N., III

    2007-01-01

    The program for the march by librarians on America's capital for the American Library Association (ALA) conference is predictably loaded with lobbying, legislation, and DC tours. It also abounds with professional opportunity and reflects the impact of Leslie Burger, one of the most activist ALA presidents in recent history. Her "Transformation"…

  16. Transformation & Metamorphosis

    ERIC Educational Resources Information Center

    Lott, Debra

    2009-01-01

    The sculptures of Canadian artist Brian Jungen are a great inspiration for a lesson on creating new forms. Jungen transforms found objects into unique creations without fully concealing their original form or purpose. Frank Stella's sculpture series, including "K.132,2007" made of stainless steel and spray paint, is another great example of…

  17. Transforming Schools.

    ERIC Educational Resources Information Center

    Cookson, Peter W., Jr., Ed.; Schneider, Barbara, Ed.

    The authors in this book address the issues that relate to the crisis in American education and review some of the proposed solutions. To transform education, schools must be examined as social systems that are interrelated with families, communities, and the world of work. Following the introduction, section 1, "Conditions for Educational…

  18. Neutrino scattering and flavor transformation in supernovae.

    PubMed

    Cherry, John F; Carlson, J; Friedland, Alexander; Fuller, George M; Vlasenko, Alexey

    2012-06-29

    We argue that the small fraction of neutrinos that undergo direction-changing scattering outside of the neutrinosphere could have significant influence on neutrino flavor transformation in core-collapse supernova environments. We show that the standard treatment for collective neutrino flavor transformation is adequate at late times but could be inadequate in early epochs of core-collapse supernovae, where the potentials that govern neutrino flavor evolution are affected by the scattered neutrinos. Taking account of this effect, and the way it couples to entropy and composition, will require a new approach in neutrino flavor transformation modeling. PMID:23004955

  19. Technology Transformation

    ERIC Educational Resources Information Center

    Scott, Heather; McGilll, Toria

    2011-01-01

    Social networking and other technologies, if used judiciously, present the means to integrate 21st century skills into the classroom curriculum. But they also introduce challenges that educators must overcome. Increased concerns about plagiarism and access to technology can test educators' creativity and school resources. Air Academy High School,…

  20. AIR COOLED NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Szilard, L.

    1958-05-27

    A nuclear reactor of the air-cooled, graphite moderated type is described. The active core consists of a cubicle mass of graphite, approximately 25 feet in each dimension, having horizontal channels of square cross section extending between two of the opposite faces, a plurality of cylindrical uranium slugs disposed in end to end abutting relationship within said channels providing a space in the channels through which air may be circulated, and a cadmium control rod extending within a channel provided in the moderator. Suitable shielding is provlded around the core, as are also provided a fuel element loading and discharge means, and a means to circulate air through the coolant channels through the fuel charels to cool the reactor.

  1. Proof Systems and Transformation Games

    NASA Astrophysics Data System (ADS)

    Bachrach, Yoram; Zuckerman, Michael; Wooldridge, Michael; Rosenschein, Jeffrey S.

    We introduce Transformation Games (TGs), a form of coalitional game in which players are endowed with sets of initial resources, and have capabilities allowing them to derive certain output resources, given certain input resources. The aim of a TG is to generate a particular target resource; players achieve this by forming a coalition capable of performing a sequence of transformations from its combined set of initial resources to the target resource. After presenting the TG model, and discussing its interpretation, we consider possible restrictions on the transformation chain, resulting in different coalitional games. After presenting the basic model, we consider the computational complexity of several problems in TGs, such as testing whether a coalition wins, checking if a player is a dummy or a veto player, computing the core of the game, computing power indices, and checking the effects of possible restrictions on the coalition. Finally, we consider extensions to the model in which transformations have associated costs.

  2. RF transformer

    DOEpatents

    Smith, James L.; Helenberg, Harold W.; Kilsdonk, Dennis J.

    1979-01-01

    There is provided an improved RF transformer having a single-turn secondary of cylindrical shape and a coiled encapsulated primary contained within the secondary. The coil is tapered so that the narrowest separation between the primary and the secondary is at one end of the coil. The encapsulated primary is removable from the secondary so that a variety of different capacity primaries can be utilized with one secondary.

  3. Relation between gamma-ray family and EAS core: Monte-Carlo simulation of EAS core

    NASA Technical Reports Server (NTRS)

    Yanagita, T.

    1985-01-01

    Preliminary results of Monte-Carlo simulation on Extensive Air Showers (EAS) (Ne=100,000) core is reported. For the first collision at the top of the atmosphere, high multiplicity (high rapidity, density) and a large Pt (1.5GeV average) model is assumed. Most of the simulated cores show a complicated structure.

  4. Design and fabrication of embedded two elliptical cores hollow fiber

    NASA Astrophysics Data System (ADS)

    Tian, Fengjun; Yuan, Libo; Dai, Qian; Liu, Zhihai

    2011-11-01

    We propose a novel embedded two elliptical cores fiber with a hollow air hole, and demonstrate the fabrication of the embedded two elliptical cores hollow fiber (EECHF). By using a suspended core-in-tube technique, the fibers are drawn from the preform utilizing a fiber drawing system with a pressure controller. The fiber have a 60μm diameter hollow air hole centrally, a 125μm diameter cladding, two 7.2μm /3.0μm (major axis/minor axis) elliptical cores, and a 3μm thickness silica cladding between core layer and air hole. The EECHF has a great potential for PMFs, high sensitivity in-fiber interferometers, poling fiber and Bio-sensor based on evanescent wave field. The fabrication technology is simple and versatile, and can be easily utilized to fabricate multi-core fiber with any desired aspect ratio elliptical core.

  5. Modeling of transformers using circuit simulators

    SciTech Connect

    Archer, W.E.; Deveney, M.F.; Nagel, R.L.

    1994-07-01

    Transformers of two different designs; and unencapsulated pot core and an encapsulated toroidal core have been modeled for circuit analysis with circuit simulation tools. We selected MicroSim`s PSPICE and Anology`s SABER as the simulation tools and used experimental BH Loop and network analyzer measurements to generate the needed input data. The models are compared for accuracy and convergence using the circuit simulators. Results are presented which demonstrate the effects on circuit performance from magnetic core losses, eddy currents, and mechanical stress on the magnetic cores.

  6. Hamlet's Transformation.

    NASA Astrophysics Data System (ADS)

    Usher, P. D.

    1997-12-01

    William Shakespeare's Hamlet has much evidence to suggest that the Bard was aware of the cosmological models of his time, specifically the geocentric bounded Ptolemaic and Tychonic models, and the infinite Diggesian. Moreover, Shakespeare describes how the Ptolemaic model is to be transformed to the Diggesian. Hamlet's "transformation" is the reason that Claudius, who personifies the Ptolemaic model, summons Rosencrantz and Guildenstern, who personify the Tychonic. Pantometria, written by Leonard Digges and his son Thomas in 1571, contains the first technical use of the word "transformation." At age thirty, Thomas Digges went on to propose his Perfit Description, as alluded to in Act Five where Hamlet's age is given as thirty. In Act Five as well, the words "bore" and "arms" refer to Thomas' vocation as muster-master and his scientific interest in ballistics. England's leading astronomer was also the father of the poet whose encomium introduced the First Folio of 1623. His oldest child Dudley became a member of the Virginia Company and facilitated the writing of The Tempest. Taken as a whole, such manifold connections to Thomas Digges support Hotson's contention that Shakespeare knew the Digges family. Rosencrantz and Guildenstern in Hamlet bear Danish names because they personify the Danish model, while the king's name is latinized like that of Claudius Ptolemaeus. The reason Shakespeare anglicized "Amleth" to "Hamlet" was because he saw a parallel between Book Three of Saxo Grammaticus and the eventual triumph of the Diggesian model. But Shakespeare eschewed Book Four, creating this particular ending from an infinity of other possibilities because it "suited his purpose," viz. to celebrate the concept of a boundless universe of stars like the Sun.

  7. An accurate continuous calibration system for high voltage current transformer

    SciTech Connect

    Tong Yue; Li Binhong

    2011-02-15

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

  8. An accurate continuous calibration system for high voltage current transformer.

    PubMed

    Tong, Yue; Li, Bin Hong

    2011-02-01

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site. PMID:21361633

  9. Air Abrasion

    MedlinePlus

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  10. TRANSFORMER APPARATUS

    DOEpatents

    Wolfgang, F.; Nicol, J.

    1962-11-01

    Transformer apparatus is designed for measuring the amount of a paramagnetic substance dissolved or suspended in a diamagnetic liquid. The apparatus consists of a cluster of tubes, some of which are closed and have sealed within the diamagnetic substance without any of the paramagnetic material. The remaining tubes are open to flow of the mix- ture. Primary and secondary conductors are wrapped around the tubes in such a way as to cancel noise components and also to produce a differential signal on the secondaries based upon variations of the content of the paramagnetic material. (AEC)

  11. Rotary Transformer

    NASA Technical Reports Server (NTRS)

    McLyman, Colonel Wm. T.

    1996-01-01

    None given. From first Par: Many spacecraft (S/C) and surface rovers require the transfer of signals and power across rotating interfaces. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain (S/C) configurations. Delivery of signal and power has mainly been done by using the simplest means, the slip ring approach. This approach, although simple, leaves debris generating noise over a period of time...The rotary transformer is a good alternative to slip rings for signal and power transfer.

  12. Corn transformed

    SciTech Connect

    Moffat, A.S.

    1990-08-10

    Researchers have produced fertile corn transformed with a foreign gene that makes the plants resistant to the herbicide bialaphos. This achievement, is the first report of fertile transgenic corn in the reviewed literature, and it is the capstone of almost a decade's efforts to genetically engineer this country's most important crop. The only other major crop to be so manipulated is rice. The ability produce transgenic corn gives biologists a valuable tool to probe the whys and hows of gene expression and regulation. It may also give plant breeders a way to develop new corn varieties with a speed and predictability that would be impossible with classical breeding techniques.

  13. Analysis of parametric transformer with rectifier load

    SciTech Connect

    Ichinokura, O.; Jinzenji, T. ); Tajima, K. )

    1993-03-01

    This paper describes a push-pull parametric transformer constructed using a pair of orthogonal-cores. The operating characteristics of the parametric transformer with a rectifier load were analyzed based on SPICE simulations. The analysis results show good agreement with experiment. It was found that the input surge current of the full-wave rectifier circuit with a smoothing capacitor can be compensated by the parametric transformer. Use of the parametric transformer as a power stabilizer is anticipated owing to its various functions such as for voltage regulation and overload protection.

  14. Transformational leadership.

    PubMed

    Marlow, D L

    1996-01-01

    In these uncertain times in the healthcare industry, administrators are asked to do more with less time and resources. Because of the extended roles they are playing in today's organizations, radiology administrators are looked upon as agents of change. What leadership skills do they need in this turbulent and uncertain healthcare environment? What are the trait's of tomorrow's leaders? The transformational leader is the one who will guide us through this changing healthcare environment. Several behavioral patterns emerge as important traits for tomorrow's leaders to have-individual consideration, intellectual stimulation and charisma. Tomorrow's leader must view each person as an individual, showing genuine concern and belief in each person's ability to perform. Transformational leaders stimulate others by encouraging them to be curious and try new ideas. The final characteristic, charisma, is the ability to inspire others. Luckily, leaders are made, not born: today's leaders can learn to be responsive, to draw out new ideas from employees, and to communicate self-esteem, energy and enthusiasm. PMID:10163135

  15. Herbicide Transformation

    PubMed Central

    Lanzilotta, R. P.; Pramer, David

    1970-01-01

    A strain of Fusarium solani isolated from soil by enrichment techniques used propanil (3′, 4′-dichloropropionanilide) as a sole source of organic carbon and energy for growth in pure culture. The primary product of the transformation of propanil by F. solani was isolated and identified as 3,4-dichloroaniline (DCA). This compound accumulated in the medium to a level (80 μg/ml) which stopped further herbicide utilization. Herbicide utilization by F. solani was influenced by various environmental and nutritional factors. It was more sensitive to acid than alkaline pH. Added glucose and yeast extract increased the rate of propanil decomposition, and the reduced aeration retarded growth of the fungus and herbicide utilization. The growth of F. solani on propionate was inhibited by added DCA. Images PMID:5437305

  16. High temperature co-axial winding transformers

    NASA Technical Reports Server (NTRS)

    Divan, Deepakraj M.; Novotny, Donald W.

    1993-01-01

    The analysis and design of co-axial winding transformers is presented. The design equations are derived and the different design approaches are discussed. One of the most important features of co-axial winding transformers is the fact that the leakage inductance is well controlled and can be made low. This is not the case in conventional winding transformers. In addition, the power density of co-axial winding transformers is higher than conventional ones. Hence, using co-axial winding transformers in a certain converter topology improves the power density of the converter. The design methodology used in meeting the proposed specifications of the co-axial winding transformer specifications are presented and discussed. The final transformer design was constructed in the lab. Co-axial winding transformers proved to be a good choice for high power density and high frequency applications. They have a more predictable performance compared with conventional transformers. In addition, the leakage inductance of the transformer can be controlled easily to suit a specific application. For space applications, one major concern is the extraction of heat from power apparatus to prevent excessive heating and hence damaging of these units. Because of the vacuum environment, the only way to extract heat is by using a cold plate. One advantage of co-axial winding transformers is that the surface area available to extract heat from is very large compared to conventional transformers. This stems from the unique structure of the co-axial transformer where the whole core surface area is exposed and can be utilized for cooling effectively. This is a crucial issue here since most of the losses are core losses.

  17. Parallel fast gauss transform

    SciTech Connect

    Sampath, Rahul S; Sundar, Hari; Veerapaneni, Shravan

    2010-01-01

    We present fast adaptive parallel algorithms to compute the sum of N Gaussians at N points. Direct sequential computation of this sum would take O(N{sup 2}) time. The parallel time complexity estimates for our algorithms are O(N/n{sub p}) for uniform point distributions and O( (N/n{sub p}) log (N/n{sub p}) + n{sub p}log n{sub p}) for non-uniform distributions using n{sub p} CPUs. We incorporate a plane-wave representation of the Gaussian kernel which permits 'diagonal translation'. We use parallel octrees and a new scheme for translating the plane-waves to efficiently handle non-uniform distributions. Computing the transform to six-digit accuracy at 120 billion points took approximately 140 seconds using 4096 cores on the Jaguar supercomputer. Our implementation is 'kernel-independent' and can handle other 'Gaussian-type' kernels even when explicit analytic expression for the kernel is not known. These algorithms form a new class of core computational machinery for solving parabolic PDEs on massively parallel architectures.

  18. Transformation of Botrytis cinerea by direct hyphal blasting or by wound-mediated transformation of sclerotia

    PubMed Central

    2011-01-01

    Background Botrytis cinerea is a haploid necrotrophic ascomycete which is responsible for 'grey mold' disease in more than 200 plant species. Broad molecular research has been conducted on this pathogen in recent years, resulting in the sequencing of two strains, which has generated a wealth of information toward developing additional tools for molecular transcriptome, proteome and secretome investigations. Nonetheless, transformation protocols have remained a significant bottleneck for this pathogen, hindering functional analysis research in many labs. Results In this study, we tested three different transformation methods for B. cinerea: electroporation, air-pressure-mediated and sclerotium-mediated transformation. We demonstrate successful transformation with three different DNA constructs using both air-pressure- and sclerotium-mediated transformation. Conclusions These transformation methods, which are fast, simple and reproducible, can expedite functional gene analysis of B. cinerea. PMID:22188865

  19. Core-core and core-valence correlation

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    The effect of (1s) core correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipole moment and 1 Sigma + - 1 Pi transition dipole moment were studied. The results of the FCI calculations are compared to those obtained using approximate methods. In addition, the generation of atomic natural orbital (ANO) basis sets, as a method for contracting a primitive basis set for both valence and core correlation, is discussed. When both core-core and core-valence correlation are included in the calculation, no suitable truncated CI approach consistently reproduces the FCI, and contraction of the basis set is very difficult. If the (nearly constant) core-core correlation is eliminated, and only the core-valence correlation is included, CASSCF/MRCI approached reproduce the FCI results and basis set contraction is significantly easier.

  20. Direct-Current Monitor With Flux-Reset Transformer Coupling

    NASA Technical Reports Server (NTRS)

    Canter, Stanley

    1993-01-01

    Circuit measures constant or slowly-varying unidirectional electrical current using flux-reset transformer coupling. Measurement nonintrusive in sense that no need for direct contact with wire that carries load current to be measured, and no need to install series resistive element in load-current path. Toroidal magnetic core wrapped with coil of wire placed around load-current-carrying wire, acts as transformer core, load-current-carrying wire acts as primary winding of transformer, and coil wrapped on core acts as secondary winding.

  1. Transformation of benign fibroadenoma to malignant phyllodes tumor.

    PubMed

    Sanders, Linda M; Daigle, Megan E; Tortora, Matthew; Panasiti, Ryane

    2015-07-01

    The transformation of a benign fibroadenoma into a phyllodes tumor is uncommon and unpredictable. We report the case of a 40-year-old woman with a core biopsy proven fibroadenoma that underwent transformation into a malignant phyllodes tumor after 3 years of size stability. We present ultrasound and magnetic resonance images, as well as pathology slides from core biopsy and surgical excision, to illustrate this transformation. It has been suggested that phyllodes tumors may be misdiagnosed as fibroadenomas by core biopsy. However, in this case, pathology supports correct initial diagnosis of fibroadenoma and demonstrates a portion of the original fibroadenoma along the periphery of the malignant phyllodes tumor. PMID:26331090

  2. DC-Compensated Current Transformer

    PubMed Central

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

  3. Design of toroidal transformers for maximum efficiency

    NASA Technical Reports Server (NTRS)

    Dayton, J. A., Jr.

    1972-01-01

    The design of the most efficient toroidal transformer that can be built given the frequency, volt-ampere rating, magnetic flux density, window fill factor, and materials is described. With the above all held constant and only the dimensions of the magnetic core varied, the most efficient design occurs when the copper losses equal 60 percent of the iron losses. When this criterion is followed, efficiency is only slightly dependent on design frequency and fill factor. The ratios of inside diameter to outside diameter and height to build of the magnetic core that result in transformers of maximum efficiency are computed.

  4. Entrapment of carbon dioxide with chitosan-based core-shell particles containing changeable cores.

    PubMed

    Dong, Yanrui; Fu, Yinghao; Lin, Xia; Xiao, Congming

    2016-08-01

    Water-soluble chitosan-based core-shell particles that contained changeable cores were successfully applied to anchor carbon dioxide. The entrapment capacity of the particles for carbon dioxide (EC) depended on the cores. It was found that EC of the particles contained aqueous cores was higher than that of the beads with water-soluble chitosan gel cores, which was confirmed with thermogravimetric analysis. In addition, calcium ions and sodium hydroxide were introduced within the particles to examine their effect on the entrapment. EC of the particles was enhanced with sodium hydroxide when the cores were WSC gel. The incorporation of calcium ions was helpful for stabilizing carbon dioxide through the formation of calcium carbonate, which was verified with Fourier transform infrared spectra and scanning electron microscopy/energy-dispersive spectrometry. This phenomenon meant the role of calcium ions for fixating carbon dioxide was significant. PMID:27174910

  5. Evaluating Community Health Advisor (CHA) Core Competencies: The CHA Core Competency Retrospective Pretest/Posttest (CCCRP).

    PubMed

    Story, Lachel; To, Yen M

    2016-05-01

    Health care and academic systems are increasingly collaborating with community health advisors (CHAs) to provide culturally relevant health interventions that promote sustained community transformation. Little attention has been placed on CHA training evaluation, including core competency attainment. This study identified common CHA core competencies, generated a theoretically based measure of those competencies, and explored psychometric properties of that measure. A concept synthesis revealed five CHA core competencies (leadership, translation, guidance, advocacy, and caring). The CHA Core Competency Retrospective Pretest/Posttest (CCCRP) resulted from that synthesis, which was administered using multiple approaches to individuals who previously received CHA training (N= 142). Exploratory factor analyses revealed a two-factor structure underlying the posttraining data, and Cronbach's alpha indicated high internal consistency. This study suggested some CHA core competencies might be more interrelated than previously thought, and two major competencies exist rather than five and supported the CCCRP's use to evaluate core competency attainment resulting from training. PMID:25416701

  6. CCSNMultivar: Core-Collapse Supernova Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Engels, Bill; Gossan, Sarah

    2016-04-01

    CCSNMultivar aids the analysis of core-collapse supernova gravitational waves. It includes multivariate regression of Fourier transformed or time domain waveforms, hypothesis testing for measuring the influence of physical parameters, and the Abdikamalov et. al. catalog for example use. CCSNMultivar can optionally incorporate additional uncertainty due to detector noise and approximate waveforms from anywhere within the parameter space.

  7. Concise Synthesis of Astellatol Core Skeleton.

    PubMed

    Zhao, Nan; Xie, Shengling; Chen, Gui; Xu, Jing

    2016-08-26

    A ten-step, enantiospecific synthesis of the highly challenging core skeleton of sesterterpenoid astellatol has been achieved. Key transformations of this strategy include a facile, convergent construction of the tricyclic motif and a SmI2 -induced reductive radical cyclization that forms the pivotal cyclobutane ring. PMID:27398681

  8. Dual Transformer Model based on Standard Circuit Elements for the Study of Low- and Mid-frequency Transients

    NASA Astrophysics Data System (ADS)

    Jazebi, Saeed

    iron core magnetizing characteristic is modified with the accurate measurement of the air-core inductance. The air-core inductance is measured using a non-ideal low-power rectifier. Its dc output serves to drive the transformer into deep saturation, and its ripple provides low-amplitude variable excitation. The principal advantage of this method is its simplicity. To model the eddy current effects in the windings, a novel equivalent circuit is proposed. The circuit is derived from the principle of duality and therefore, matches the electromagnetic physical behavior of the transformer windings. It properly models the flux paths and current distribution from dc to MHz. The model is synthesized from a non-uniform concentric discretization of the windings. Concise guidelines are given to optimally calculate the width of the sub-divisions for various transient simulations. To compute the circuit parameters only information about the geometry of the windings and about their material properties is needed. The calculation of the circuit parameters does not require an iterative process. Therefore, the parameters are always real, positive, and free from convergence problems. The proposed model is tested with single-phase transformers for the calculation of magnetizing inrush currents, series ferroresonance, and Geomagnetic Induced Currents (GIC). The electromagnetic transient response of the model is compared to laboratory measurements for validation. Also, 3D finite element simulations are used to validate the electromagnetic behavior of the transformer model. Large manufacturer of transformers, power system designers, and electrical utility companies can benefit from the new model. It simplifies the design and optimization of the transformers' insulation, thereby reducing cost, and enhancing reliability of the system. The model could also be used for inrush current and differential protection studies, geomagnetic induced current studies, harmonic penetration studies, and

  9. Air resources

    SciTech Connect

    1995-10-01

    This section describes the ambient (surrounding) air quality of the TVA region, discusses TVA emission contributions to ambient air quality, and identifies air quality impacts to human health and welfare. Volume 2 Technical Document 2, Environmental Consequences, describes how changes in TVA emissions could affect regional air quality, human health, environmental resources, and materials. The primary region of the affected environment is broadly defined as the state of Tennessee, as well as southern Kentucky, western Virginia, southern West Virginia, western North Carolina, and northern Georgia, Alabama, and Mississippi. This area represents the watershed of the Tennessee River and the 201 counties of the greater TVA service area. Emissions from outside the Tennessee Valley region contribute to air quality in the Valley. Also, TVA emissions are transported outside the Valley and have some impact on air quality beyond the primary study area. Although the study area experiences a number of air quality problems, overall air quality is good.

  10. Air Pollution.

    ERIC Educational Resources Information Center

    Gilpin, Alan

    A summary of one of our most pressing environmental problems, air pollution, is offered in this book by the Director of Air Pollution Control for the Queensland (Australia) State Government. Discussion of the subject is not restricted to Queensland or Australian problems and policies, however, but includes analysis of air pollution the world over.…

  11. Academic Rigor: The Core of the Core

    ERIC Educational Resources Information Center

    Brunner, Judy

    2013-01-01

    Some educators see the Common Core State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common Core are not the only…

  12. Parameter estimation for transformer modeling

    NASA Astrophysics Data System (ADS)

    Cho, Sung Don

    Large Power transformers, an aging and vulnerable part of our energy infrastructure, are at choke points in the grid and are key to reliability and security. Damage or destruction due to vandalism, misoperation, or other unexpected events is of great concern, given replacement costs upward of $2M and lead time of 12 months. Transient overvoltages can cause great damage and there is much interest in improving computer simulation models to correctly predict and avoid the consequences. EMTP (the Electromagnetic Transients Program) has been developed for computer simulation of power system transients. Component models for most equipment have been developed and benchmarked. Power transformers would appear to be simple. However, due to their nonlinear and frequency-dependent behaviors, they can be one of the most complex system components to model. It is imperative that the applied models be appropriate for the range of frequencies and excitation levels that the system experiences. Thus, transformer modeling is not a mature field and newer improved models must be made available. In this work, improved topologically-correct duality-based models are developed for three-phase autotransformers having five-legged, three-legged, and shell-form cores. The main problem in the implementation of detailed models is the lack of complete and reliable data, as no international standard suggests how to measure and calculate parameters. Therefore, parameter estimation methods are developed here to determine the parameters of a given model in cases where available information is incomplete. The transformer nameplate data is required and relative physical dimensions of the core are estimated. The models include a separate representation of each segment of the core, including hysteresis of the core, lambda-i saturation characteristic, capacitive effects, and frequency dependency of winding resistance and core loss. Steady-state excitation, and de-energization and re-energization transients

  13. Next-Generation Assessments Aligned to the Common Core

    ERIC Educational Resources Information Center

    Willhoft, Joseph L.

    2012-01-01

    Through the Common Core State Standards and the development of new assessments aligned to the standards, the public education system is undergoing a transformation--and administrators can help make this vision a reality. Today, more than 45 states and the District of Columbia have adopted the Common Core State Standards. The standards, however,…

  14. Modelling the pulse transformer in SPICE

    NASA Astrophysics Data System (ADS)

    Godlewska, Malgorzata; Górecki, Krzysztof; Górski, Krzysztof

    2016-01-01

    The paper is devoted to modelling pulse transformers in SPICE. It shows the character of the selected models of this element, points out their advantages and disadvantages, and presents the results of experimental verification of the considered models. These models are characterized by varying degrees of complexity - from linearly coupled linear coils to nonlinear electrothermal models. The study was conducted for transformer with ring cores made of a variety of ferromagnetic materials, while exciting the sinusoidal signal of a frequency 100 kHz and different values of load resistance. The transformers operating conditions under which the considered models ensure the acceptable accuracy of calculations are indicated.

  15. Interfaith Dialogue as a Means for Transformational Conversations

    ERIC Educational Resources Information Center

    Krebs, Stephanie Russell

    2015-01-01

    This article reports findings, inspired by the researcher's personal, transformational experience, on students' responses to an interfaith dialogue at an Interfaith Youth Core Interfaith Leadership Institute. Results demonstrated that several factors characterize interfaith dialogue: the environment, individual relationships fostered through…

  16. Transformer coupling for transmitting direct current through a barrier

    DOEpatents

    Brown, R.L.; Guilford, R.P.; Stichman, J.H.

    1987-06-29

    The transmission system for transmitting direct current from an energy source on one side of an electrical and mechanical barrier to a load on the other side of the barrier utilizes a transformer comprising a primary core on one side of the transformer and a secondary core on the other side of the transformer. The cores are magnetically coupled selectively by moving a magnetic ferrite coupler in and out of alignment with the poles of the cores. The direct current from the energy source is converted to a time varying current by an oscillating circuit, which oscillating circuit is optically coupled to a secondary winding on the secondary core to interrupt oscillations upon the voltage in the secondary winding exceeding a preselected level. 4 figs.

  17. Transformer coupling for transmitting direct current through a barrier

    DOEpatents

    Brown, Ralph L.; Guilford, Richard P.; Stichman, John H.

    1988-01-01

    The transmission system for transmitting direct current from an energy source on one side of an electrical and mechanical barrier to a load on the other side of the barrier utilizes a transformer comprising a primary core on one side of the transformer and a secondary core on the other side of the transformer. The cores are magnetically coupled selectively by moving a magnetic ferrite coupler in and out of alignment with the poles of the cores. The direct current from the energy source is converted to a time varying current by an oscillating circuit, which oscillating circuit is optically coupled to a secondary winding on the secondary core to interrupt oscillations upon the voltage in the secondary winding exceeding a preselected level.

  18. Investigating the relationship between k-core and s-core network decompositions

    NASA Astrophysics Data System (ADS)

    Eidsaa, Marius; Almaas, Eivind

    2016-05-01

    Network decomposition methods, such as the much used k-core analysis, are able to identify globally central regions of networks. The decomposition approaches are hierarchical and identify nested sets of nodes with increasing centrality properties. While most studies have been concerned with unweighted networks, i.e. k-core analysis, recent works have introduced network decomposition methods that apply to weighted networks. Here, we investigate the relationship between k-core decomposition for unweighted networks and s-core decomposition for weighted networks by systematically employing a link-weight scheme that gradually discretizes the link weights. We applied this approach to the Erdős-Rényi model and the scale-free configuration model for five different weight distributions, and two empirical networks, the US air traffic network and a Facebook network. We find that (1) both uniformly random and positively correlated link-weight distributions give rise to highly stable s-core decompositions with respect to discretization levels. (2) For negatively correlated link-weight distributions, the resulting s-core decomposition has no similarity to the k-cores. Since several combinations of network topology and link-weight distributions give rise to a core-structure that is highly similar to the full s-core for a large range of link-discretization levels, it is possible to significantly speed up the numerical s-core analysis for these situations.

  19. Suspended core photonic microcells for sensing and device applications.

    PubMed

    Wang, Chao; Jin, Wei; Ma, Jun; Wang, Ying; Ho, Hoi Lut; Shi, Xin

    2013-06-01

    In-line fiber-optic microcells are fabricated by postprocessing NKT LMA10 photonic crystal fibers. The cells are suspended core (SC) elements created by locally inflating some of the air holes while the core is being tapered. Based on a SC microcell with six air holes, a cantilever beam accelerometer is demonstrated. The microcells could also be used as gain and absorption cells for amplifier and spectroscopy applications. PMID:23722776

  20. Zero Carryover Liquid-Desiccant Air Conditioner for Solar Applications: Preprint

    SciTech Connect

    Lowenstein, A.; Slayzak, S.; Kozubal, E.

    2006-07-01

    A novel liquid-desiccant air conditioner that dries and cools building supply air will transform the use of direct-contact liquid-desiccant systems in HVAC applications, improving comfort, air quality, and providing energy-efficient humidity control.

  1. Fabrication of Superconducting Traction Transformer for Railway Rolling Stock

    NASA Astrophysics Data System (ADS)

    Kamijo, H.; Hata, H.; Fujimoto, H.; Inoue, A.; Nagashima, K.; Ikeda, K.; Yamada, H.; Sanuki, Y.; Tomioka, A.; Uwamori, K.; Yoshida, S.; Iwakuma, M.; Funaki, K.

    2006-06-01

    We designed a floor type single-phase 4 MVA superconducting traction transformer for Shinkansen rolling stock. In this study, we fabricated a prototype superconducting traction transformer based on this design. This transformer of the core-type design has a primary winding, four secondary windings and a tertiary winding. The windings are wound by Bi2223 superconducting tapes and cooled by subcooled liquid nitrogen. The core is kept at room temperature. The cryostat is made of GFRP with two holes to pass core legs through. The outer dimensions are about 1.2m × 0.7m × 1.9m excluding the compressor. Its weight is 1.71t excluding that of refrigerator and compressor. The transformer was tested according to Japanese Industrial Standards (JIS)-E5007. We confirmed that the performance of transformer has been achieved almost exactly as planned. The rated capacity is equivalent to 3.5MVA in the superconducting state.

  2. Solar core homology, solar neutrinos and helioseismology

    SciTech Connect

    Bludman, S.A.; Kennedy, D.C.

    1995-12-31

    Precise numerical standard solar models (SSMs) now agree with one another and with helioseismological observations in the convective and outer radiative zones. Nevertheless these models obscure how luminosity, neutrino production and g-mode core helioseismology depend on such inputs as opacity and nuclear cross sections. Although the Sun is not homologous, its inner core by itself is chemically evolved and almost homologous, because of its compactness, radiative energy transport, and ppI-dominated luminosity production. We apply luminosity-fixed homology transformations to the core to estimate theoretical uncertainties in the SSM and to obtain a broad class of non-SSMs, parameterized by central temperature and density and purely radiative energy transport in the core. 25 refs., 3 figs., 3 tabs.

  3. Ferrofluid-based Stretchable Magnetic Core Inductors

    NASA Astrophysics Data System (ADS)

    Lazarus, N.; Meyer, C. D.

    2015-12-01

    Magnetic materials are commonly used in inductor and transformer cores to increase inductance density. The emerging field of stretchable electronics poses a new challenge since typical magnetic cores are bulky, rigid and often brittle. This paper presents, for the first time, stretchable inductors incorporating ferrofluid as a liquid magnetic core. Ferrofluids, suspensions of nanoscale magnetic particles in a carrier liquid, provide enhanced magnetic permeability without changing the mechanical properties of the surrounding elastomer. The inductor tested in this work consisted of a liquid metal solenoid wrapped around a ferrofluid core in separate channels. The low frequency inductance was found to increase from 255 nH before fill to 390 nH after fill with ferrofluid, an increase of 52%. The inductor was also shown to survive uniaxial strains of up to 100%.

  4. Transforming Distance Education Curricula through Distributive Leadership

    ERIC Educational Resources Information Center

    Keppell, Mike; O'Dwyer, Carolyn; Lyon, Betsy; Childs, Merilyn

    2011-01-01

    This paper examines a core leadership strategy for transforming learning and teaching in distance education through flexible and blended learning. It focuses on a project centred on distributive leadership that involves collaboration, shared purpose, responsibility and recognition of leadership irrespective of role or position within an…

  5. Transforming the structure of a health system.

    PubMed

    Reilly, Patrick

    2012-06-01

    In starting the planning process for an organization's transformation or restructuring, healthcare finance leaders should: Identify strategic imperatives for the organization and physicians, Remember the organization's core area of business, Define the starting point and create clear objectives, Develop a strategy that engages front-line employees to change the culture of the organization. PMID:22734323

  6. Transforming Distance Education Curricula through Distributive Leadership

    ERIC Educational Resources Information Center

    Keppell, Mike; O'Dwyer, Carolyn; Lyon, Betsy; Childs, Merilyn

    2010-01-01

    This paper examines a core leadership strategy for transforming learning and teaching in distance education through flexible and blended learning. It focuses on a project centred on distributive leadership that involves collaboration, shared purpose, responsibility and recognition of leadership irrespective of role or position within an…

  7. Serious Play with Dynamic Plane Transformations

    ERIC Educational Resources Information Center

    King, James

    2011-01-01

    Transformations are a central organizing idea in geometry. They are included in most geometry curricula and are likely to appear with even greater emphasis in the future, given the central role they play in the "Common Core State Standards" for K-12 mathematics. One of the attractions of geometry is the ability to draw and construct the…

  8. The core to regulatory reform

    SciTech Connect

    Partridge, J.W. Jr.

    1993-06-15

    Federal Energy Regulatory Commission (FERC) Orders 436, 500, and 636, the Clean Air Act Amendments of 1990, Public Utility Holding Company Act reform, and the 1992 Energy Policy Act all can have significant effects on an LDC's operations. Such changes in an LDC's environments must be balanced by changes within the utility, its marketplace, and its state regulatory environment. The question is where to start. For Columbia Gas Distribution Cos., based in Columbus, OH, the new operating foundation begins with each employee. Internal strength is critical in designing initiatives that meet the needs of the marketplace and are well-received by regulators. Employees must understand not only the regulatory environment in which the LDC operates, but also how their work contributes to a positive regulatory relationship. To achieve this, Columbia initiated the COntinuing Regulatory Education program, or CORE, in 1991. CORE is a regulatory-focused, information-initiative program coordinated by Columbia's Regulatory Policy, Planning, and Government Affairs Department. The CORE programs can take many forms, such as emerging issue discussions, dialogues with regulators and key parties, updates on regulatory fillings, regulatory policy meetings, and formal training classes. The speakers and discussion facilitators can range from human resource department trainers to senior officers, from regulatory department staff members to external experts, or from state commissioners to executives from other LDCs. The goals of CORE initiatives are to: Support a professional level of regulatory expertise through employee participation in well-developed regulatory programs presented by credible experts. Encourage a constructive state regulatory environment founded on communication and cooperation. CORE achieves these goals via five program levels: introductory basics, advanced learning, professional expertise, crossfunctional dialogues, and external idea exchanges.

  9. Advanced air revitalization system testing

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Hallick, T. M.; Schubert, F. H.

    1983-01-01

    A previously developed experimental air revitalization system was tested cyclically and parametrically. One-button startup without manual interventions; extension by 1350 hours of tests with the system; capability for varying process air carbon dioxide partial pressure and humidity and coolant source for simulation of realistic space vehicle interfaces; dynamic system performance response on the interaction of the electrochemical depolarized carbon dioxide concentrator, the Sabatier carbon dioxide reduction subsystem, and the static feed water electrolysis oxygen generation subsystem, the carbon dioxide concentrator module with unitized core technology for the liquid cooled cell; and a preliminary design for a regenerative air revitalization system for the space station are discussed.

  10. Identity transformation in medical students.

    PubMed

    Cohen, Mitchell J M; Kay, Abigail; Youakim, James M; Balaicuis, John M; Balacius, John M

    2009-03-01

    This paper reviews the literature on the impact of medical school on personal development and consolidation of core identity. The limited literature relies on reports from medical students' journaling exercises, discussion groups, post-graduation surveys, and repeated personality testing. We review forces acting on medical students, with potential transforming effects. These forces include high external expectations and internal fear of superficial knowledge and skills, entry into the culture of medicine with its insider jargon and hierarchy, high academic workload, and the emotional burdens of confronting cadavers and death as well as bearing witness to patients' suffering. Potential developmental delay, emergence of substance abuse and hedonic acting out, cynicism, and loss of individual core values are possible consequences. Protections against these adverse outcomes include identification of strong mentors and role models, developing post-conventional morality and relativistic thinking, finding healthy coping strategies such as peer support, and remaining intellectually creative and personally reflective. PMID:19295620

  11. Imagining a Transformed UNESCO with Learning at Its Core

    ERIC Educational Resources Information Center

    Benavot, Aaron

    2011-01-01

    This paper argues that key aspects of UNESCO's organizational culture are a major impediment to the realization of its important educational agenda. Drawing upon sustained observations over a four-year period, the paper describes the nature and consequences of UNESCO's highly ritualized and "inward-oriented" work activities, especially the weak…

  12. Transformational Teaching: Theoretical Underpinnings, Basic Principles, and Core Methods

    ERIC Educational Resources Information Center

    Slavich, George M.; Zimbardo, Philip G.

    2012-01-01

    Approaches to classroom instruction have evolved considerably over the past 50 years. This progress has been spurred by the development of several learning principles and methods of instruction, including active learning, student-centered learning, collaborative learning, experiential learning, and problem-based learning. In the present paper, we…

  13. Coring Sample Acquisition Tool

    NASA Technical Reports Server (NTRS)

    Haddad, Nicolas E.; Murray, Saben D.; Walkemeyer, Phillip E.; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Kriechbaum, Kristopher L.; Richardson, Megan; Klein, Kerry J.

    2012-01-01

    A sample acquisition tool (SAT) has been developed that can be used autonomously to sample drill and capture rock cores. The tool is designed to accommodate core transfer using a sample tube to the IMSAH (integrated Mars sample acquisition and handling) SHEC (sample handling, encapsulation, and containerization) without ever touching the pristine core sample in the transfer process.

  14. The Core Skills Initiative.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    A British initiative that aims to identify, develop, and assess core skills in post-16 courses and qualifications is summarized in this bulletin. The first section discusses expectations regarding what core skills can achieve. The following section focuses on other purposes to which core skills could contribute, such as broadening the post-16…

  15. Core Competence and Education.

    ERIC Educational Resources Information Center

    Holmes, Gary; Hooper, Nick

    2000-01-01

    Outlines the concept of core competence and applies it to postcompulsory education in the United Kingdom. Adopts an educational perspective that suggests accreditation as the core competence of universities. This economic approach suggests that the market trend toward lifetime learning might best be met by institutions developing a core competence…

  16. Core Design Applications

    1995-07-12

    CORD-2 is intended for core desigh applications of pressurized water reactors. The main objective was to assemble a core design system which could be used for simple calculations (such as frequently required for fuel management) as well as for accurate calculations (for example, core design after refueling).

  17. Estimates of Cl atom concentrations and hydrocarbon kinetic reactivity in surface air at Appledore Island, Maine (USA), during International Consortium for Atmospheric Research on Transport and Transformation/Chemistry of Halogens at the Isles of Shoals

    NASA Astrophysics Data System (ADS)

    Pszenny, Alexander A. P.; Fischer, Emily V.; Russo, Rachel S.; Sive, Barkley C.; Varner, Ruth K.

    2007-05-01

    Average hydroxyl radical (OH) to chlorine atom (Cl·) ratios ranging from 45 to 119 were determined from variability-lifetime relationships for selected nonmethane hydrocarbons (NMHC) in surface air from six different transport sectors arriving at Appledore Island, Maine, during July 2004. Multiplying these ratios by an assumed average OH concentration of 2.5 × 106 cm-3 yielded estimates of Cl· concentrations of 2.2 to 5.6 × 104 cm-3. Summed reaction rates of methane and more than 30 abundant NMHCs with OH and Cl· suggest that Cl· reactions increased the kinetic reactivity of hydrocarbons by 16% to 30% over that due to OH alone in air associated with the various transport sectors. Isoprene and other abundant biogenic alkenes were the most important hydrocarbon contributors after methane to overall kinetic reactivity.

  18. Fourier Transform Spectrometer measurements of Atmospheric Carbon Dioxide and Methane

    NASA Astrophysics Data System (ADS)

    Kivi, Rigel; Heikkinen, Pauli; Chen, Huilin; Hatakka, Juha; Laurila, Tuomas

    2016-04-01

    Ground based remote sensing measurements of column CO2 and CH4 using Fourier Transform Spectrometers (FTS) within the Total Carbon Column Observing Network (TCCON) are known for high precision and accuracy. These measurements are performed at various locations globally and they have been widely used in carbon cycle studies and validation of space born measurements. The relevant satellite missions include the Orbiting Carbon Observatory-2 (OCO-2) by the National Aeronautics and Space Administration (NASA); the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) by the European Space Agency (ESA); the Greenhouse gases Observing SATellite (GOSAT) by the Japan Aerospace Exploration Agency (JAXA) and the upcoming Sentinel-5 Precursor mission, which is an ESA mission and scheduled for launch in 2016. Results of the column CO2 and CH4 measurements at Sodankylä in northern Finland (at 67.4° N, 26.6° E) are reported in this study. The measurements have been performed on regular basis since the beginning of the program in early 2009. We also present evaluation of the data quality of the ground based measurements and comparisons with the available satellite based retrievals. In case of comparisons between the GOSAT and ground based retrievals of CO2 and CH4 no significant biases were found. Sodankylä is one of the northernmost stations in the TCCON network. However, the data coverage has been relatively good thanks to the progress towards automation of the FTS measurement system. At Sodankylä the retrievals have been also compared with the balloon borne AirCore measurements at the site. AirCore sampling system is directly related to the World Meteorological Organization in situ trace gas measurement scales. The balloon platform allows sampling in both stratosphere and troposphere, which is a benefit, compared to the aircraft in situ measurements.

  19. Preparation of hollow core/shell microspheres of hematite and its adsorption ability for samarium.

    PubMed

    Yu, Sheng-Hui; Yao, Qi-Zhi; Zhou, Gen-Tao; Fu, Sheng-Quan

    2014-07-01

    Hollow core/shell hematite microspheres with diameter of ca. 1-2 μm have been successfully achieved by calcining the precursor composite microspheres of pyrite and polyvinylpyrrolidone (PVP) in air. The synthesized products were characterized by a wide range of techniques including powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and Brunauer-Emmett-Teller (BET) gas sorptometry. Temperature- and time-dependent experiments unveil that the precursor pyrite-PVP composite microspheres finally transform into hollow core/shell hematite microspheres in air through a multistep process including the oxidation and sulfation of pyrite, combustion of PVP occluded in the precursor, desulfation, aggregation, and fusion of nanosized hematite as well as mass transportation from the interior to the exterior of the microspheres. The formation of the hollow core/shell microspheres dominantly depends on the calcination temperature under current experimental conditions, and the aggregation of hematite nanocrystals and the core shrinking during the oxidation of pyrite are responsible for the formation of the hollow structures. Moreover, the adsorption ability of the hematite for Sm(III) was also tested. The results exhibit that the hematite microspheres have good adsorption activity for trivalent samarium, and that its adsorption capacity strongly depends on the pH of the solution, and the maximum adsorption capacity for Sm(III) is 14.48 mg/g at neutral pH. As samarium is a typical member of the lanthanide series, our results suggest that the hollow hematite microspheres have potential application in removal of rare earth elements (REEs) entering the water environment. PMID:24892188

  20. Improved Rotary Transformer For Shaft-Position Indicator

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1991-01-01

    Improved rotary transformer for Inductosyn (or equivalent) shaft-position-indicating circuit has pair of ferrite cores instead of the solid-iron cores. Designed with view toward decreasing excitation power (to maximum allowable 2 W) supplied to shaft-position-indicating circuit to increase its output signal and make tracking system less vulnerable to electromagnetic interference.

  1. Ultrabroadband polarization splitter based on three-core photonic crystal fiber with a modulation core.

    PubMed

    Zhao, Tongtong; Lou, Shuqin; Wang, Xin; Zhou, Min; Lian, Zhenggang

    2016-08-10

    We design an ultrabroadband polarization splitter based on three-core photonic crystal fiber (PCF). A modulation core and two fluorine-doped cores are introduced to achieve an ultrawide bandwidth. The properties of three-core PCF are modeled by using the full-vector finite element method along with the full-vector beam propagation method. Numerical results demonstrate that an ultrabroadband splitter with 320 nm bandwidth with an extinction ratio as low as -20  dB can be achieved by using 52.8 mm long three-core PCF. This splitter also has high compatibility with standard single-mode fibers as the input and output ports due to low splicing loss of 0.02 dB. All the air holes in the proposed structure are circular holes and arranged in a triangular lattice that makes it easy to fabricate. PMID:27534489

  2. "Snowing" Core in Earth?

    NASA Astrophysics Data System (ADS)

    Li, J.; Chen, B.; Cormier, V.; Gao, L.; Gubbins, D.; Kharlamova, S. A.; He, K.; Yang, H.

    2008-12-01

    As a planet cools, an initially molten core gradually solidifies. Solidification occurs at shallow depths in the form of "snow", if the liquidus temperature gradient of the core composition is smaller than the adiabatic temperature gradient in the core. Experimental data on the melting behavior of iron-sulfur binary system suggest that the cores of Mercury and Ganymede are probably snowing at the present time. The Martian core is predicted to snow in the future, provided that the sulfur content falls into the range of 10 to 14 weight percent. Is the Earth's core snowing? If so, what are the surface manifestations? If the Earth's core snowed in the past, how did it affect the formation of the solid inner core and the geodynamo? Here, we evaluate the likelihood and consequences of a snowing core throughout the Earth's history, on the basis of mineral physics data describing the melting behavior, equation-of-state, and thermodynamic properties of iron-rich alloys at high pressures. We discuss if snowing in the present-day Earth can reproduce the shallow gradients of compressional wave velocity above the inner-core boundary, and whether or not snowing in the early Earth may reconcile the apparent young age of the solid inner core with a long-lived geodynamo.

  3. Continuous coring drill bit

    SciTech Connect

    Ford, G.A.

    1987-09-22

    A continuous coring drill bit is described comprising: (a) body means defining a vertical axis and adapted for connection to drill pipe and forming an internal body cavity disposed in eccentric relation with the vertical axis and a generally circular throat in communication with the body cavity for conducting drilling fluid. The throat defining a throat axis coincident with the vertical axis and being of a configuration permitting passage of a formation core into the body cavity; (b) a generally cylindrical tubular core breaker being rotatably mounted within the body cavity and defining a vertical axis of rotation of generally parallel and offset relation with the vertical axis of the body means; and (c) a buttress element extending inwardly from the core breaker and adapted to contact the formation core. Upon each rotation of the drill bit the buttress element applying transverse force to the core for fracturing of the core into sections sufficiently small for transport by the drilling fluid.

  4. Amorphous metal distribution transformers: The energy-efficient alternative

    SciTech Connect

    Garrity, T.F.

    1994-12-31

    Amorphous metal distribution transformers have been commercially available for the past 13 years. During that time, they have realized the promise of exceptionally high core efficiency as compared to silicon steel transformer cores. Utility planners today must consider all options available to meet the requirements of load growth. While additional generation capacity will be added, many demand-side initiatives are being undertaken as complementary programs to generation expansion. The efficiency improvement provided by amorphous metal distribution transformers deserves to be among the demand-side options. The key to understanding the positive impact of amorphous metal transformer efficiency is to consider the aggregate contribution those transformers can make towards demand reduction. It is estimated that distribution transformer core losses comprise at least 1% of the utility`s peak demand. Because core losses are continuous, any significant reduction in their magnitude is of great significance to the planner. This paper describes the system-wide economic contributions amorphous metal distribution transformers can make to a utility and suggests evaluation techniques that can be used. As a conservation tool, the amorphous metal transformer contributes to reduced power plant emissions. Calibration of those emissions reductions is also discussed in the paper.

  5. Typical Phases of Transformative Learning: A Practice-Based Model

    ERIC Educational Resources Information Center

    Nohl, Arnd-Michael

    2015-01-01

    Empirical models of transformative learning offer important insights into the core characteristics of this concept. Whereas previous analyses were limited to specific social groups or topical terrains, this article empirically typifies the phases of transformative learning on the basis of a comparative analysis of various social groups and topical…

  6. HYDRATE CORE DRILLING TESTS

    SciTech Connect

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate formation comprised of coarse, large

  7. 23. CORE WORKER OPERATING A COREBLOWER THAT PNEUMATICALLY FILLED CORE ...

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

    23. CORE WORKER OPERATING A CORE-BLOWER THAT PNEUMATICALLY FILLED CORE BOXES WITH RESIGN IMPREGNATED SAND AND CREATED A CORE THAT THEN REQUIRED BAKING, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  8. VLBI Observations of the Free Core Nutations

    NASA Astrophysics Data System (ADS)

    Smylie, D. E.

    2012-12-01

    At core scale lengths with periods from a few hours to days, the Coriolis acceleration dominates the Lorentz force density and core modes can be considered as purely mechanical. One of the most interesting core modes is the spin-over mode, which reflects the ability of the outer core to rotate about an axis different from that of either the inner core or the shell. It has a nearly diurnal period. In the Earth frame of reference, this mode produces the nearly diurnal retrograde wobble. In the space frame of reference it is accompanied by the free core nutations. When the flattening of the boundaries of the fluid outer core and the figure-figure gravitational coupling are taken into account, as well as the deformability of the boundaries, both a retrograde free core nutation and a prograde free core nutation are found. The retrograde free core nutation was first predicted by Poincare (1910) for a completly fluid, incompressible core bounded by a rigid shell. In a variational calculation of wobble-nutation modes in realistic Earth models, Jiang (1993) found the classical retrograde free core nutation (RFCN) but discovered a prograde free core nutation (PFCN) as well. VLBI residuals in longitude and obliquity compared to the 1980 IAU nutation series, and their standard errors, were downloaded from the Goddard Space Flight Center website, for the period August 3, 1979 to March 6, 2003, giving 3343 points over a span of 8617 days. In an overlapping segment analysis, the discrete Fourier transform (DFT) for each segment was found for the corresponding series of unequally spaced nutation residuals by singular value decomposition (SVD), with the number of singular values eliminated determined by the satisfaction of Parseval's theorem. Both the RFCN and the PFCN resonances were found in the resulting power spectrum. The nutation resonances were found to be in free decay, the half-life of the PFCN at 2620 days and that of the RFCN at 2229 days, with Ekman boundary layer

  9. Air Pollution.

    ERIC Educational Resources Information Center

    Fox, Donald L.

    1989-01-01

    Materials related to air pollution are reviewed for the period January 1987, to October 1988. The topics are pollution monitoring, air pollution, and environmental chemistry. The organization consists of two major analytical divisions: (1) gaseous methods; and (2) aerosol and particulate methods. (MVL)

  10. Air Pollution.

    EPA Science Inventory

    Air quality is affected by many types of pollutants that are emitted from various sources, including stationary and mobile. These sources release both criteria and hazardous air pollutants, which cause health effects, ecological harm, and material damage. They are generally categ...

  11. Core-Cutoff Tool

    NASA Technical Reports Server (NTRS)

    Gheen, Darrell

    2007-01-01

    A tool makes a cut perpendicular to the cylindrical axis of a core hole at a predetermined depth to free the core at that depth. The tool does not damage the surrounding material from which the core was cut, and it operates within the core-hole kerf. Coring usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the core (sometimes called the plug ) in place. In this approach to coring as practiced heretofore, the core is removed forcibly in a manner chosen to shear the core, preferably at or near the greatest depth of the core hole. Unfortunately, such forcible removal often damages both the core and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a core is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the damage associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the core hole. The sleeves are thin enough that this tool fits within the kerf of the core hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the core. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer core pulls the cutting wire into contact with the core. The cutting force of the wire against the core increases with the tension in the wire and

  12. Lunar core: occam's razor?

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Whether or not the earth's moon has a core is a much bandied question. Like many notions about the properties of the moon, ideas of a lunar core changed drastically after the Apollo studies. A review of the development of these ideas was given a scholarly treatment by S.K. Runcorn recently (Nature, 304, 589-596, 1983). In contrast, L.L. Hood, C.P. Sonett, and L.J. Srnka have questioned the concept in serious detail (Nature, 307, 661-662, 1984).Whether or not the moon actually has or has had a fluid metallic core is of great consequence for a number of geophysical theories about the solar system. Most investigators concede that the possible existence of a lunar core remains one of the major unanswered, and yet most critical, questions about the moon. A lot rides on the answer: Can a lunar-sized body have a core? Is the core metallic? How is the core related to lunar magnetism and its paleomagnetism? Is or was a lunar core related to lunar volcanism? If the moon can have a core, is planetary core formation in the solar system a simple matter of gravitationally segregating metallic fragments that were formed elsewhere? Implications of the questions are without limit. There is, perhaps, no more valid issue about the moon to explore scientifically.

  13. Regenerative air heater

    DOEpatents

    Hasselquist, Paul B.; Baldner, Richard

    1982-01-01

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  14. Regenerative air heater

    DOEpatents

    Hasselquist, P.B.; Baldner, R.

    1980-11-26

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  15. 121. VIEW OF SOUTH SIDE OF TRANSFORMER ROOM (112), LSB ...

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

    121. VIEW OF SOUTH SIDE OF TRANSFORMER ROOM (112), LSB (BLDG. 770), FROM MECHANICAL AND ELECTRICAL ROOM (110) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  16. 49. Interior of launch support building, buck boost transformer at ...

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

    49. Interior of launch support building, buck boost transformer at center, view towards southwest - Ellsworth Air Force Base, Delta Flight, Launch Facility, On County Road T512, south of Exit 116 off I-90, Interior, Jackson County, SD

  17. INTERIOR OF NORTH ENTRY VESTIBULE, SHOWING TRANSFORMER ROOM BEHIND WIRE ...

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

    INTERIOR OF NORTH ENTRY VESTIBULE, SHOWING TRANSFORMER ROOM BEHIND WIRE MESH, VIEW FACING EAST-SOUTHEAST. - Naval Air Station Barbers Point, Telephone Exchange, Coral Sea Road north of Bismarck Sea Road, Ewa, Honolulu County, HI

  18. 123. FIRE SUPPRESSION DELUGE PANEL ON SOUTH WALL OF TRANSFORMER ...

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

    123. FIRE SUPPRESSION DELUGE PANEL ON SOUTH WALL OF TRANSFORMER ROOM (112), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  19. Spherical Harmonic Transforms with S2HAT (Scalable Spherical Harmonic Transform) Library

    NASA Astrophysics Data System (ADS)

    Fabbian, G.; Szydlarski, M.; Stompor, R.; Grigori, L.; Falcou, J.

    2012-09-01

    We present the Scalable Spherical Harmonic Transform library (S2HAT) - a portable, massively parallel, scalable library for calculating scalar and spin-weighted spherical harmonic transforms on different computer architectures, including distributed-memory, hybrid multi-/many- core platforms, as well as clusters of many GPUs and CPUs. Here we comment on the two latter cases. The numerical complexity of the library transforms is O(npix1/2ℓmax2). The S2HAT library is publicly available.

  20. Core sample extractor

    NASA Technical Reports Server (NTRS)

    Akins, James; Cobb, Billy; Hart, Steve; Leaptrotte, Jeff; Milhollin, James; Pernik, Mark

    1989-01-01

    The problem of retrieving and storing core samples from a hole drilled on the lunar surface is addressed. The total depth of the hole in question is 50 meters with a maximum diameter of 100 millimeters. The core sample itself has a diameter of 60 millimeters and will be two meters in length. It is therefore necessary to retrieve and store 25 core samples per hole. The design utilizes a control system that will stop the mechanism at a certain depth, a cam-linkage system that will fracture the core, and a storage system that will save and catalogue the cores to be extracted. The Rod Changer and Storage Design Group will provide the necessary tooling to get into the hole as well as to the core. The mechanical design for the cam-linkage system as well as the conceptual design of the storage device are described.

  1. The core paradox.

    NASA Technical Reports Server (NTRS)

    Kennedy, G. C.; Higgins, G. H.

    1973-01-01

    Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

  2. Transforming the Way We Teach Function Transformations

    ERIC Educational Resources Information Center

    Faulkenberry, Eileen Durand; Faulkenberry, Thomas J.

    2010-01-01

    In this article, the authors discuss "function," a well-defined rule that relates inputs to outputs. They have found that by using the input-output definition of "function," they can examine transformations of functions simply by looking at changes to input or output and the respective changes to the graph. Applying transformations to the input…

  3. Applications of ferro-nanofluid on a micro-transformer.

    PubMed

    Tsai, Tsung-Han; Kuo, Long-Sheng; Chen, Ping-Hei; Lee, Da-Sheng; Yang, Chin-Ting

    2010-01-01

    An on-chip transformer with a ferrofluid magnetic core has been developed and tested. The transformer consists of solenoid-type coil and a magnetic core of ferrofluid, with the former fabricated by MEMS technology and the latter by a chemical co-precipitation method. The performance of the MEMS transformer with a ferrofluid magnetic core was measured and simulated with frequencies ranging from 100 kHz to 100 MHz. Experimental results reveal that the presence of the ferrofluid increases the inductance of coils and the coupling coefficient of transformer; however, it also increases the resistance owing to the lag between the external magnetic field and the magnetization of the material. PMID:22163647

  4. Applications of Ferro-Nanofluid on a Micro-Transformer

    PubMed Central

    Tsai, Tsung-Han; Kuo, Long-Sheng; Chen, Ping-Hei; Lee, Da-sheng; Yang, Chin-Ting

    2010-01-01

    An on-chip transformer with a ferrofluid magnetic core has been developed and tested. The transformer consists of solenoid-type coil and a magnetic core of ferrofluid, with the former fabricated by MEMS technology and the latter by a chemical co-precipitation method. The performance of the MEMS transformer with a ferrofluid magnetic core was measured and simulated with frequencies ranging from 100 kHz to 100 MHz. Experimental results reveal that the presence of the ferrofluid increases the inductance of coils and the coupling coefficient of transformer; however, it also increases the resistance owing to the lag between the external magnetic field and the magnetization of the material. PMID:22163647

  5. AN Core Analysis

    NASA Astrophysics Data System (ADS)

    Barbarino, Andrea; Tomatis, Daniele

    2014-06-01

    Several alternative approximations of neutron transport have been proposed in years to move around the known limitations imposed by neutron diffusion in the modeling of nuclear cores. However, only a few complied with the industrial requirements of fast numerical computation, concentrating more on physical accuracy. In this work, the AN transport methodology is discussed with particular interest in core performance calculations. The implementation of the methodology in full core codes is discussed with particular attention to numerical issues and to the integration within the entire simulation process. Finally, first results from core studies in AN transport are analyzed in detail and compared to standard results of neutron diffusion.

  6. Helicopter engine core noise

    NASA Astrophysics Data System (ADS)

    Vonglahn, U. H.

    1982-07-01

    Calculated engine core noise levels, based on NASA Lewis prediction procedures, for five representative helicopter engines are compared with measured total helicopter noise levels and ICAO helicopter noise certification requirements. Comparisons are made for level flyover and approach procedures. The measured noise levels are generally significantly greater than those predicted for the core noise levels, except for the Sikorsky S-61 and S-64 helicopters. However, the predicted engine core noise levels are generally at or within 3 dB of the ICAO noise rules. Consequently, helicopter engine core noise can be a significant contributor to the overall helicopter noise signature.

  7. Helicopter engine core noise

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.

    1982-01-01

    Calculated engine core noise levels, based on NASA Lewis prediction procedures, for five representative helicopter engines are compared with measured total helicopter noise levels and ICAO helicopter noise certification requirements. Comparisons are made for level flyover and approach procedures. The measured noise levels are generally significantly greater than those predicted for the core noise levels, except for the Sikorsky S-61 and S-64 helicopters. However, the predicted engine core noise levels are generally at or within 3 dB of the ICAO noise rules. Consequently, helicopter engine core noise can be a significant contributor to the overall helicopter noise signature.

  8. Core Research Center

    USGS Publications Warehouse

    Hicks, Joshua; Adrian, Betty

    2009-01-01

    The Core Research Center (CRC) of the U.S. Geological Survey (USGS), located at the Denver Federal Center in Lakewood, Colo., currently houses rock core from more than 8,500 boreholes representing about 1.7 million feet of rock core from 35 States and cuttings from 54,000 boreholes representing 238 million feet of drilling in 28 States. Although most of the boreholes are located in the Rocky Mountain region, the geologic and geographic diversity of samples have helped the CRC become one of the largest and most heavily used public core repositories in the United States. Many of the boreholes represented in the collection were drilled for energy and mineral exploration, and many of the cores and cuttings were donated to the CRC by private companies in these industries. Some cores and cuttings were collected by the USGS along with other government agencies. Approximately one-half of the cores are slabbed and photographed. More than 18,000 thin sections and a large volume of analytical data from the cores and cuttings are also accessible. A growing collection of digital images of the cores are also becoming available on the CRC Web site Internet http://geology.cr.usgs.gov/crc/.

  9. A Case of Extreme Simplicity of the Core Matrix in Three-Mode Principal Components Analysis.

    ERIC Educational Resources Information Center

    Murakami, Takashi; ten Berge, Jos M. F.; Kiers, Henk A. L.

    1998-01-01

    In three-mode principal components analysis, the P x Q x R core matrix "G" can be transformed to simple structure before it is interpreted. This paper shows that, when P=QR-1, G can be transformed to have nearly all the elements equal to values specified a priori. A closed-form solution for this transformation is offered. (SLD)

  10. Scattering loss analysis and structure optimization of hollow-core photonic bandgap fiber

    NASA Astrophysics Data System (ADS)

    Song, Jingming; Wu, Rong; Sun, Kang; Xu, Xiaoliang

    2016-06-01

    Effects of core structure in 7 cell hollow-core photonic bandgap fibers (HC-PBGFs) on scattering loss are analyzed by means of investigating normalized interface field intensity. Fibers with different core wall thickness, core radius and rounding corner of air hole are simulated. Results show that with thick core wall and expanded core radius, scattering loss could be greatly reduced. The scattering loss of the HC-PBGFs in the wavelength range of 1.5-1.56 μm could be decreased by about 50 % of the present level with optimized core structure design.

  11. Symplectic wavelet transformation.

    PubMed

    Fan, Hong-Yi; Lu, Hai-Liang

    2006-12-01

    Usually a wavelet transform is based on dilated-translated wavelets. We propose a symplectic-transformed-translated wavelet family psi(*)(r,s)(z-kappa) (r,s are the symplectic transform parameters, |s|(2)-|r|(2)=1, kappa is a translation parameter) generated from the mother wavelet psi and the corresponding wavelet transformation W(psi)f(r,s;kappa)=integral(infinity)(-infinity)(d(2)z/pi)f(z)psi(*)(r,s)(z-kappa). This new transform possesses well-behaved properties and is related to the optical Fresnel transform in quantum mechanical version. PMID:17099740

  12. MultIMA- Multi-Core in Integrated Modular Avionics

    NASA Astrophysics Data System (ADS)

    Silva, Claudio; Tatibana, Cassia

    2014-08-01

    Multi-core technologies are the natural trend towards fulfilling recent space applications requirements. However, the adoption of multi-core implies increased complexity that must be addressed by application redesign or the implementation of explicit supporting mechanisms. GMV investigates multi-core and Integrated Modular Avionics as cooperative vehicles to achieve reliable support for future safety critical applications. In this paper, we describe the main challenges met in our investigations and how multi-core solutions were implemented in GMV's IMA simulator (SIMA) and operating system (AIR).

  13. Air Pollution

    MedlinePlus

    ... tobacco smoke. How is air pollution linked to climate change? While climate change is a global process, it ... ozone levels are also a concern. Impacts of Climate Change on Human Health in the United States: A ...

  14. Air Apparent.

    ERIC Educational Resources Information Center

    Harbster, David A.

    1988-01-01

    Explains the principle upon which a barometer operates. Describes how to construct two barometric devices for use in the classroom that show air's changing pressure. Cites some conditions for predicting weather. (RT)

  15. 136. VIEW OF NORTHWEST CORNER OF TRANSFORMER ROOM (212), LSB ...

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

    136. VIEW OF NORTHWEST CORNER OF TRANSFORMER ROOM (212), LSB (BLDG. 751). JEFFRIES COMPANY TRANSFORMER FOR LIGHTING SYSTEMS ON NORTH WALL, FACING SOUTH; POWER PANEL A AND POWER PANEL B ON EAST WALL, FACING WEST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  16. 128. VIEW OF NORTHWEST CORNER OF TRANSFORMER ROOM (112), BUILDING ...

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

    128. VIEW OF NORTHWEST CORNER OF TRANSFORMER ROOM (112), BUILDING 751. JEFFRIES COMPANY TRANSFORMER FOR LIGHTING SYSTEMS ON NORTH WALL, FACING SOUTH; POWER PANEL A1 ON EAST WALL, FACING WEST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  17. Core hysteresis in nematic defects

    NASA Astrophysics Data System (ADS)

    Kralj, Samo; Virga, Epifanio G.

    2002-08-01

    We study field-induced transformations in the biaxial core of a nematic disclination with strength m=1, employing the Landau-de Gennes order tensor parameter Q. We first consider the transition from the defectless escaped radial structure into the structure hosting a line defect with a negative uniaxial order parameter along the axis of a cylinder of radius R. The critical field of the transition monotonically increases with R and asymptotically approaches a value corresponding to ξb/ξf~0.3, where the correlation lengths ξb and ξf are related to the biaxial order and the external field, respectively. Then, in the same geometry, we focus on the line defect structure with a positive uniaxial ordering along the axis, surrounded by the uniaxial sheath, the uniaxial cylinder of radius ξu with negative order parameter and director in the transverse direction. We study the hysteresis in the position of the uniaxial sheath upon increasing and decreasing the field strength. In general, two qualitatively different solutions exist, corresponding to the uniaxial sheath located close to the defect symmetry axis or close to the cylinder wall. This latter solution exists only for strong enough anchorings. The uniaxial sheath is for a line defect what the uniaxial ring is for a point defect: by resorting to an approximate analytic estimate, we show that essentially the same hysteresis exhibited by the uniaxial sheath is expected to occur at the uniaxial ring in the core structure of a point defect.

  18. Reconceptualising Core Skills

    ERIC Educational Resources Information Center

    Canning, Roy

    2007-01-01

    The paper provides an analysis of Core Skill policy and practice in the UK. The author presents a conceptual basis for re-thinking generic Core Skills within educational approaches in teaching and learning. The discussion looks at whether universal notions of generic skills are appropriate when considering post-compulsory pedagogic approaches to…

  19. The Common Core.

    ERIC Educational Resources Information Center

    Boyer, Ernest L.

    Current curricula in institutions of higher education are criticized in this speech for their lack of a common core of education. Several possibilities for developing such a common core include education centered around our common heritage and the challenges of the present. It is suggested that all students must be introduced to the events,…

  20. Making an Ice Core.

    ERIC Educational Resources Information Center

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  1. Iowa Core Annual Report

    ERIC Educational Resources Information Center

    Iowa Department of Education, 2015

    2015-01-01

    One central component of a great school system is a clear set of expectations, or standards, that educators help all students reach. In Iowa, that effort is known as the Iowa Core. The Iowa Core represents the statewide academic standards, which describe what students should know and be able to do in math, science, English language arts, and…

  2. CORE - Performance Feedback System

    2009-10-02

    CORE is an architecture to bridge the gaps between disparate data integration and delivery of disparate information visualization. The CORE Technology Program includes a suite of tools and user-centered staff that can facilitate rapid delivery of a deployable integrated information to users.

  3. Core Skills in Action.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    This bulletin provides an update on current developments in core skills in further education. Section 1 contains information about the Further Education Unit's (FEU's) Core Skills Post-16 project, in which colleges are testing principles that underpin all good quality learning programs. Important findings and examples are outlined under the five…

  4. NFE Core Bibliographies.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Inst. for International Studies in Education.

    This collection of core bibliographies, which expands on an initial bibliography published in 1979 of the core resources housed in the Non-Formal Education Information Center at Michigan State University, comprises a basic stock of materials on nonformal education and women in development that have been contributed by development planners,…

  5. Ice Core Investigations

    ERIC Educational Resources Information Center

    Krim, Jessica; Brody, Michael

    2008-01-01

    What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

  6. Equations For Rotary Transformers

    NASA Technical Reports Server (NTRS)

    Salomon, Phil M.; Wiktor, Peter J.; Marchetto, Carl A.

    1988-01-01

    Equations derived for input impedance, input power, and ratio of secondary current to primary current of rotary transformer. Used for quick analysis of transformer designs. Circuit model commonly used in textbooks on theory of ac circuits.

  7. Chemical Transformation Simulator

    EPA Science Inventory

    The Chemical Transformation Simulator (CTS) is a web-based, high-throughput screening tool that automates the calculation and collection of physicochemical properties for an organic chemical of interest and its predicted products resulting from transformations in environmental sy...

  8. Transformation of Pasteurella novicida

    PubMed Central

    Tyeryar, Franklin J.; Lawton, William D.

    1969-01-01

    Deoxyribonucleic acid from a streptomycin-resistant mutant of Pasteurella novicida transformed portions of P. novicida streptomycin-sensitive populations to streptomycin-resistant. Similarly, mutants auxotrophic for tryptophan or purine biosynthesis were also transformed to nutritional independence. PMID:5359612

  9. Lunar Core and Tides

    NASA Technical Reports Server (NTRS)

    Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

    2004-01-01

    Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

  10. Internal core tightener

    DOEpatents

    Brynsvold, Glen V.; Snyder, Jr., Harold J.

    1976-06-22

    An internal core tightener which is a linear actuated (vertical actuation motion) expanding device utilizing a minimum of moving parts to perform the lateral tightening function. The key features are: (1) large contact areas to transmit loads during reactor operation; (2) actuation cam surfaces loaded only during clamping and unclamping operation; (3) separation of the parts and internal operation involved in the holding function from those involved in the actuation function; and (4) preloaded pads with compliant travel at each face of the hexagonal assembly at the two clamping planes to accommodate thermal expansion and irradiation induced swelling. The latter feature enables use of a "fixed" outer core boundary, and thus eliminates the uncertainty in gross core dimensions, and potential for rapid core reactivity changes as a result of core dimensional change.

  11. The MSPICE simulation of a saturating transformer

    NASA Astrophysics Data System (ADS)

    Maclean, David N.

    A transformer is simulated using a nonlinear saturating magnetic model. Hysteresis and gradual smooth reduction of core permeability are achieved with standard SPICE networks and functions. The equations that define the nonlinear inductance and the MSPICE circuits used to simulate them are derived. A hierarchy of circuit complexity that is based on the structured logic design subcircuit method is used. An example of a push-pull buck regulator being operated in an unbalanced condition is given. Noise ripple on the input power cable generates a dc offset current in the transformer. The example demonstrates how avionics power equipment can be evaluated for large-signal ac, dc, and transient behavior.

  12. Shiftable multiscale transforms

    NASA Technical Reports Server (NTRS)

    Simoncelli, Eero P.; Freeman, William T.; Adelson, Edward H.; Heeger, David J.

    1992-01-01

    A type of translational invariance, referred to as shiftability, is defined for wavelet transforms. The property of shiftability is first discussed with respect to individual parameters: spatial position, orientation, and scale. The discussion then focuses on transformations that are simultaneously shiftable with respect to subsets of these parameters. It is shown that the critical sampling condition on the wavelet transforms must be relaxed to achieve shiftability. Two example transforms are implemented and applied to several signal and image processing problems.

  13. Design of space-type electronic power transformers

    NASA Technical Reports Server (NTRS)

    Ahearn, J. F.; Lagadinos, J. C.

    1977-01-01

    Both open and encapsulated varieties of high reliability, low weight, and high efficiency moderate and high voltage transformers were investigated to determine the advantages and limitations of their construction in the ranges of power and voltage required for operation in the hard vacuum environment of space. Topics covered include: (1) selection of the core material; (2) preliminary calculation of core dimensions; (3) selection of insulating materials including magnet wire insulation, coil forms, and layer and interwinding insulation; (4) coil design; (5) calculation of copper losses, core losses and efficiency; (6) calculation of temperature rise; and (7) optimization of design with changes in core selection or coil design as required to meet specifications.

  14. Achieving Perspective Transformation.

    ERIC Educational Resources Information Center

    Nowak, Jens

    Perspective transformation is a consciously achieved state in which the individual's perspective on life is transformed. The new perspective serves as a vantage point for life's actions and interactions, affecting the way life is lived. Three conditions are basic to achieving perspective transformation: (1) "feeling" experience, i.e., getting in…

  15. 34. DESPATCH CORE OVENS, GREY IRON FOUNDRY CORE ROOM, BAKES ...

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

    34. DESPATCH CORE OVENS, GREY IRON FOUNDRY CORE ROOM, BAKES CORES THAT ARE NOT MADE ON HEATED OR COLD BOX CORE MACHINES, TO SET BINDING AGENTS MIXED WITH THE SAND CREATING CORES HARD ENOUGH TO WITHSTAND THE FLOW OF MOLTEN IRON INSIDE A MOLD. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  16. Polymer-bonded NiZn ferrite magnetic cores mixed with titanium (IV) isopropoxide (C12H28O4Ti)

    NASA Astrophysics Data System (ADS)

    Cheng, K. W. E.; Ding, Kai; Ho, S. L.; Fu, W. N.; Wang, Junhua; Wang, Shuxiao

    2011-04-01

    For decades, the technology and engineering domains have been constantly demanding high-performance magnetic materials. Recently, polymer bonded NiZn ferrite magnetic materials mixed with titanium (IV) isopropoxide (C12H28O4Ti) for power converter applications have been found to be very promising in reducing the loss, cost, and material weight when compared to their conventional counterparts using air-core technology, conventional soft ferrites, and powder iron. The proposed magnetic core is flexible in both size and shape and is not brittle. The design of a high-frequency transformer for a 100 W two-transistor forward converter-based electric vehicle battery charger operating at a switching frequency of 360 kHz is reported in this paper. Printed circuit board prototyping and experimental results as well as comparisons with conventional converters are provided to validate the application feasibility of the proposed materials.

  17. Multiple Core Galaxies

    NASA Technical Reports Server (NTRS)

    Miller, R.H.; Morrison, David (Technical Monitor)

    1994-01-01

    Nuclei of galaxies often show complicated density structures and perplexing kinematic signatures. In the past we have reported numerical experiments indicating a natural tendency for galaxies to show nuclei offset with respect to nearby isophotes and for the nucleus to have a radial velocity different from the galaxy's systemic velocity. Other experiments show normal mode oscillations in galaxies with large amplitudes. These oscillations do not damp appreciably over a Hubble time. The common thread running through all these is that galaxies often show evidence of ringing, bouncing, or sloshing around in unexpected ways, even though they have not been disturbed by any external event. Recent observational evidence shows yet another phenomenon indicating the dynamical complexity of central regions of galaxies: multiple cores (M31, Markarian 315 and 463 for example). These systems can hardly be static. We noted long-lived multiple core systems in galaxies in numerical experiments some years ago, and we have more recently followed up with a series of experiments on multiple core galaxies, starting with two cores. The relevant parameters are the energy in the orbiting clumps, their relative.masses, the (local) strength of the potential well representing the parent galaxy, and the number of cores. We have studied the dependence of the merger rates and the nature of the final merger product on these parameters. Individual cores survive much longer in stronger background potentials. Cores can survive for a substantial fraction of a Hubble time if they travel on reasonable orbits.

  18. High-Efficiency, Low-Weight Power Transformer

    NASA Technical Reports Server (NTRS)

    Welsh, J. P.

    1986-01-01

    Technology for design and fabrication of radically new type of conductioncooled high-power (25 kVA) lightweight transformer having outstanding thermal and electrical characteristics. Fulfills longstanding need for conduction-cooled transformers and magnetics with low internal thermal resistances. Development techniques limited to conductive heat transfer, since other techniques such as liquid cooling, forced liquid cooling, and evaporative cooling of transformers impractical in zero-gravity space environment. Transformer uniquely designed: mechanical structure also serves as thermal paths for conduction cooling of magnetic core and windings.

  19. Note: Tesla transformer damping

    NASA Astrophysics Data System (ADS)

    Reed, J. L.

    2012-07-01

    Unexpected heavy damping in the two winding Tesla pulse transformer is shown to be due to small primary inductances. A small primary inductance is a necessary condition of operability, but is also a refractory inefficiency. A 30% performance loss is demonstrated using a typical "spiral strip" transformer. The loss is investigated by examining damping terms added to the transformer's governing equations. A significant alteration of the transformer's architecture is suggested to mitigate these losses. Experimental and simulated data comparing the 2 and 3 winding transformers are cited to support the suggestion.

  20. Air surveillance

    SciTech Connect

    Patton, G.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the air surveillance and monitoring programs currently in operation at that Hanford Site. Atmospheric releases of pollutants from Hanford to the surrounding region are a potential source of human exposure. For that reason, both radioactive and nonradioactive materials in air are monitored at a number of locations. The influence of Hanford emissions on local radionuclide concentrations was evaluated by comparing concentrations measured at distant locations within the region to concentrations measured at the Site perimeter. This section discusses sample collection, analytical methods, and the results of the Hanford air surveillance program. A complete listing of all analytical results summarized in this section is reported separately by Bisping (1995).

  1. Boson core compressibility

    NASA Astrophysics Data System (ADS)

    Khorramzadeh, Y.; Lin, Fei; Scarola, V. W.

    2012-04-01

    Strongly interacting atoms trapped in optical lattices can be used to explore phase diagrams of Hubbard models. Spatial inhomogeneity due to trapping typically obscures distinguishing observables. We propose that measures using boson double occupancy avoid trapping effects to reveal two key correlation functions. We define a boson core compressibility and core superfluid stiffness in terms of double occupancy. We use quantum Monte Carlo on the Bose-Hubbard model to empirically show that these quantities intrinsically eliminate edge effects to reveal correlations near the trap center. The boson core compressibility offers a generally applicable tool that can be used to experimentally map out phase transitions between compressible and incompressible states.

  2. Global Core Plasma Model

    NASA Technical Reports Server (NTRS)

    Gallagher, Dennis L.; Craven, P. D.; Comfort, R. H.

    1999-01-01

    Abstract. The Global Core Plasma Model (GCPM) provides, empirically derived, core plasma density as a function of geomagnetic and solar conditions throughout the inner magnetosphere. It is continuous in value and gradient and is composed of separate models for the ionosphere, the plasmasphere, the plasmapause, the trough, and the polar cap. The relative composition of plasmaspheric H+, He+, and O+ is included in the GCPM. A blunt plasmaspheric bulge and rotation of the bulge with changing geomagnetic conditions is included. The GCPM is an amalgam of density models, intended to serve as a framework for continued improvement as new measurements become available and are used to characterize core plasma density, composition, and temperature.

  3. Core shroud corner joints

    DOEpatents

    Gilmore, Charles B.; Forsyth, David R.

    2013-09-10

    A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

  4. Transformation pathways of liposomes.

    PubMed

    Hotani, H

    1984-09-01

    Liposomes undergoing transformation were observed by dark-field light microscopy in order to study the role of lipid in morphogenesis of biological vesicular structures. Liposomes were found to transform sequentially in a well-defined manner through one of several transformation pathways. A circular biconcave form was an initial shape in all the pathways and it transformed into a stable thin flexible filament or small spheres via a variety of regularly shaped vesicles which possessed geometrical symmetry. The transformation was reversible up to a certain point in each pathway. Osmotic pressure was found to be the driving force for the transformations. Biological membrane vesicles such as trypsinized red cell ghosts also transformed by similar pathways. PMID:6548263

  5. Magnetorotational iron core collapse

    NASA Technical Reports Server (NTRS)

    Symbalisty, E. M. D.

    1984-01-01

    During its final evolutionary stages, a massive star, as considered in current astrophysical theory, undergoes rapid collapse, thereby triggering a sequence of a catastrophic event which results in a Type II supernova explosion. A remnant neutron star or a black hole is left after the explosion. Stellar collapse occurs, when thermonuclear fusion has consumed the lighter elements present. At this stage, the core consists of iron. Difficulties arise regarding an appropriate model with respect to the core collapse. The present investigation is concerned with the evolution of a Type II supernova core including the effects of rotation and magnetic fields. A simple neutrino model is developed which reproduced the spherically symmetric results of Bowers and Wilson (1982). Several two-dimensional computational models of stellar collapse are studied, taking into account a case in which a 15 solar masses iron core was artificially given rotational and magnetic energy.

  6. Contaminated Sediment Core Profiling

    EPA Science Inventory

    Evaluating the environmental risk of sites containing contaminated sediments often poses major challenges due in part to the absence of detailed information available for a given location. Sediment core profiling is often utilized during preliminary environmental investigations ...

  7. Geophysics: Earth's core problem

    NASA Astrophysics Data System (ADS)

    Dobson, David

    2016-06-01

    Measurements of the electrical resistance and thermal conductivity of iron at extreme pressures and temperatures cast fresh light on controversial numerical simulations of the properties of Earth's outer core. See Letters p.95 & 99

  8. Biospecimen Core Resource - TCGA

    Cancer.gov

    The Cancer Genome Atlas (TCGA) Biospecimen Core Resource centralized laboratory reviews and processes blood and tissue samples and their associated data using optimized standard operating procedures for the entire TCGA Research Network.

  9. Micro coring apparatus

    NASA Technical Reports Server (NTRS)

    Collins, David; Brooks, Marshall; Chen, Paul; Dwelle, Paul; Fischer, Ben

    1989-01-01

    A micro-coring apparatus for lunar exploration applications, that is compatible with the other components of the Walking Mobile Platform, was designed. The primary purpose of core sampling is to gain an understanding of the geological composition and properties of the prescribed environment. This procedure has been used extensively for Earth studies and in limited applications during lunar explorations. The corer is described and analyzed for effectiveness.

  10. Nuclear core positioning system

    DOEpatents

    Garkisch, Hans D.; Yant, Howard W.; Patterson, John F.

    1979-01-01

    A structural support system for the core of a nuclear reactor which achieves relatively restricted clearances at operating conditions and yet allows sufficient clearance between fuel assemblies at refueling temperatures. Axially displaced spacer pads having variable between pad spacing and a temperature compensated radial restraint system are utilized to maintain clearances between the fuel elements. The core support plates are constructed of metals specially chosen such that differential thermal expansion produces positive restraint at operating temperatures.

  11. Core bounce supernovae

    SciTech Connect

    Cooperstein, J.

    1987-01-01

    The gravitational collapse mechanism for Type II supernovae is considered, concentrating on the direct implosion - core bounce - hydrodynamic explosion picture. We examine the influence of the stiffness of the dense matter equation of state and discuss how the shock wave is formed. Its chances of success are determined by the equation of state, general relativistic effects, neutrino transport, and the size of presupernova iron core. 12 refs., 1 tab.

  12. Air Pollution.

    ERIC Educational Resources Information Center

    Scorer, Richard S.

    The purpose of this book is to describe the basic mechanisms whereby pollution is transported and diffused in the atmosphere. It is designed to give practitioners an understanding of basic mechanics and physics so they may have a correct basis on which to formulate their decisions related to practical air pollution control problems. Since many…

  13. /Air Atmospheres

    NASA Astrophysics Data System (ADS)

    Emami, Samar; Sohn, Hong Yong; Kim, Hang Goo

    2014-08-01

    Molten magnesium oxidizes rapidly when exposed to air causing melt loss and handling difficulties. The use of certain additive gases such as SF6, SO2, and CO2 to form a protective MgO layer over a magnesium melt has been proposed. The oxidation behavior of molten magnesium in air containing various concentrations of SF6 was investigated. Measurements of the kinetics of the oxide layer growth at various SF6 concentrations in air and temperatures were made. Experiments were performed using a thermogravimetric analysis unit in the temperature range of 943 K to 1043 K (670 °C to 770 °C). Results showed that a thin, coherent, and protective MgF2 layer was formed under SF6/Air mixtures, with a thickness ranging from 300 nm to 3 μm depending on SF6 concentration, temperature, and exposure time. Rate parameters were calculated and a model for the process was developed. The morphology and composition of the surface films were studied using scanning electron microscope and energy-dispersive spectroscope.

  14. Air Pollution

    PubMed Central

    Clifton, Marjorie

    1964-01-01

    Dr Marjorie Clifton describes the classification of gaseous and nongaseous constituents of air pollution and then outlines the methods of measuring these. The National Survey embraced 150 towns of all sizes throughout England and Wales and provided data on smoke and sulphur dioxide in relation to climate, topography, industrialization, population density, fuel utilization and urban development. Dr W C Turner discusses the relationship between air pollution and mortality from respiratory conditions, and particularly the incidence of chronic bronchitis. He postulates a theory that such respiratory conditions arise as an allergy to the spores of certain moulds, spore formation being encouraged by the air humidity in Greatv Britain and overcrowded and damp living conditions. He describes the results of a twenty-week study undertaken in 1962-3, showing associations between respiratory disease and levels of air pollution. Dr Stuart Carne undertook a survey in general practice to plot the patterns of respiratory illness in London during the winter of 1962-3. There were two peaks of respiratory illnesses coinciding with the fog at the beginning of December and the freeze-up from the end of December until the beginning of March. PMID:14178955

  15. Air Trafficco

    ERIC Educational Resources Information Center

    Kasunic, Kevin

    1970-01-01

    The work of the 14,000 air traffic controllers can be both challenging and nerve-racking. Concentration, steady nerves, and a clear voice are required to remember the routing and identification of the maze of aircraft and to instruct each of them accurately. Controllers must have a high school diploma and three years work experience or a college…

  16. Ejector subassembly for dual wall air drilling

    SciTech Connect

    Kolle, J.J.

    1996-09-01

    The dry drilling system developed for the Yucca Mountain Site Characterization Project incorporates a surface vacuum system to prevent drilling air and cuttings from contaminating the borehole wall during coring operations. As the drilling depth increases, however there is a potential for borehole contamination because of the limited volume of air which can be removed by the vacuum system. A feasibility analysis has shown that an ejector subassembly mounted in the drill string above the core barrel could significantly enhance the depth capacity of the dry drilling system. The ejector subassembly would use a portion of the air supplied to the core bit to maintain a vacuum on the hole bottom. The results of a design study including performance testing of laboratory scale ejector simulator are presented here.

  17. Emergency core cooling system

    DOEpatents

    Schenewerk, William E.; Glasgow, Lyle E.

    1983-01-01

    A liquid metal cooled fast breeder reactor provided with an emergency core cooling system includes a reactor vessel which contains a reactor core comprising an array of fuel assemblies and a plurality of blanket assemblies. The reactor core is immersed in a pool of liquid metal coolant. The reactor also includes a primary coolant system comprising a pump and conduits for circulating liquid metal coolant to the reactor core and through the fuel and blanket assemblies of the core. A converging-diverging venturi nozzle with an intermediate throat section is provided in between the assemblies and the pump. The intermediate throat section of the nozzle is provided with at least one opening which is in fluid communication with the pool of liquid sodium. In normal operation, coolant flows from the pump through the nozzle to the assemblies with very little fluid flowing through the opening in the throat. However, when the pump is not running, residual heat in the core causes fluid from the pool to flow through the opening in the throat of the nozzle and outwardly through the nozzle to the assemblies, thus providing a means of removing decay heat.

  18. MCNP LWR Core Generator

    SciTech Connect

    Fischer, Noah A.

    2012-08-14

    The reactor core input generator allows for MCNP input files to be tailored to design specifications and generated in seconds. Full reactor models can now easily be created by specifying a small set of parameters and generating an MCNP input for a full reactor core. Axial zoning of the core will allow for density variation in the fuel and moderator, with pin-by-pin fidelity, so that BWR cores can more accurately be modeled. LWR core work in progress: (1) Reflectivity option for specifying 1/4, 1/2, or full core simulation; (2) Axial zoning for moderator densities that vary with height; (3) Generating multiple types of assemblies for different fuel enrichments; and (4) Parameters for specifying BWR box walls. Fuel pin work in progress: (1) Radial and azimuthal zoning for generating further unique materials in fuel rods; (2) Options for specifying different types of fuel for MOX or multiple burn assemblies; (3) Additional options for replacing fuel rods with burnable poison rods; and (4) Control rod/blade modeling.

  19. Investigation into the effect of transformer oil on polymers

    SciTech Connect

    Frost, N.E.; McGrath, P.B.; Burns, C.W.

    1996-01-01

    Several thermoplastics and an epoxy were exposed to a variety of conditions to determine the effect of chemical environment on the materials. Weight gain measurements of the samples were made after exposure to low humidity, ambient air, 90 C air, ambient transformer oil, and 90 C transformer oil. Two materials that performed well in these tests were polyetherimide (Ultem) and amine cured bisphenol-A epoxy. It was found that Noryl, a thermoplastic combination of high impact polystyrene and polyphenyleneoxide, was unsuitable for use in transformer oil, as it suffered substantial physical degradation. Polystyrene and high impact polystyrene (rubber modified polystyrene) performed poorly in both ambient and 90{degree} transformer oil tests, with the rubber modified material exhibiting a much greater weight gain. Both high and low density polyethylene also showed large weight gains in hot transformer oil.

  20. Transformable liquid-metal nanomedicine.

    PubMed

    Lu, Yue; Hu, Quanyin; Lin, Yiliang; Pacardo, Dennis B; Wang, Chao; Sun, Wujin; Ligler, Frances S; Dickey, Michael D; Gu, Zhen

    2015-01-01

    To date, numerous inorganic nanocarriers have been explored for drug delivery systems (DDSs). However, the clinical application of inorganic formulations has often been hindered by their toxicity and failure to biodegrade. We describe here a transformable liquid-metal nanomedicine, based on a core-shell nanosphere composed of a liquid-phase eutectic gallium-indium core and a thiolated polymeric shell. This formulation can be simply produced through a sonication-mediated method with bioconjugation flexibility. The resulting nanoparticles loaded with doxorubicin (Dox) have an average diameter of 107 nm and demonstrate the capability to fuse and subsequently degrade under a mildly acidic condition, which facilitates release of Dox in acidic endosomes after cellular internalization. Equipped with hyaluronic acid, a tumour-targeting ligand, this formulation displays enhanced chemotherapeutic inhibition towards the xenograft tumour-bearing mice. This liquid metal-based DDS with fusible and degradable behaviour under physiological conditions provides a new strategy for engineering theranostic agents with low toxicity. PMID:26625944

  1. Transformable liquid-metal nanomedicine

    NASA Astrophysics Data System (ADS)

    Lu, Yue; Hu, Quanyin; Lin, Yiliang; Pacardo, Dennis B.; Wang, Chao; Sun, Wujin; Ligler, Frances S.; Dickey, Michael D.; Gu, Zhen

    2015-12-01

    To date, numerous inorganic nanocarriers have been explored for drug delivery systems (DDSs). However, the clinical application of inorganic formulations has often been hindered by their toxicity and failure to biodegrade. We describe here a transformable liquid-metal nanomedicine, based on a core-shell nanosphere composed of a liquid-phase eutectic gallium-indium core and a thiolated polymeric shell. This formulation can be simply produced through a sonication-mediated method with bioconjugation flexibility. The resulting nanoparticles loaded with doxorubicin (Dox) have an average diameter of 107 nm and demonstrate the capability to fuse and subsequently degrade under a mildly acidic condition, which facilitates release of Dox in acidic endosomes after cellular internalization. Equipped with hyaluronic acid, a tumour-targeting ligand, this formulation displays enhanced chemotherapeutic inhibition towards the xenograft tumour-bearing mice. This liquid metal-based DDS with fusible and degradable behaviour under physiological conditions provides a new strategy for engineering theranostic agents with low toxicity.

  2. Catalytic coherence transformations

    NASA Astrophysics Data System (ADS)

    Bu, Kaifeng; Singh, Uttam; Wu, Junde

    2016-04-01

    Catalytic coherence transformations allow the otherwise impossible state transformations using only incoherent operations with the aid of an auxiliary system with finite coherence that is not being consumed in any way. Here we find the necessary and sufficient conditions for the deterministic and stochastic catalytic coherence transformations between a pair of pure quantum states. In particular, we show that the simultaneous decrease of a family of Rényi entropies of the diagonal parts of the states under consideration is a necessary and sufficient condition for the deterministic catalytic coherence transformations. Similarly, for stochastic catalytic coherence transformations we find the necessary and sufficient conditions for achieving a higher optimal probability of conversion. We thus completely characterize the coherence transformations among pure quantum states under incoherent operations. We give numerous examples to elaborate our results. We also explore the possibility of the same system acting as a catalyst for itself and find that indeed self-catalysis is possible. Further, for the cases where no catalytic coherence transformation is possible we provide entanglement-assisted coherence transformations and find the necessary and sufficient conditions for such transformations.

  3. Air ingression calculations for selected plant transients using MELCOR

    SciTech Connect

    Kmetyk, L.N.

    1994-01-01

    Two sets of MELCOR calculations have been completed studying the effects of air ingression on the consequences of various severe accident scenarios. One set of calculations analyzed a station blackout with surge line failure prior to vessel breach, starting from nominal operating conditions; the other set of calculations analyzed a station blackout occurring during shutdown (refueling) conditions. Both sets of analyses were for the Surry plant, a three-loop Westinghouse PWR. For both accident scenarios, a basecase calculation was done, and then repeated with air ingression from containment into the core region following core degradation and vessel failure. In addition to the two sets of analyses done for this program, a similar air-ingression sensitivity study was done as part of a low-power/shutdown PRA, with results summarized here; that PRA study also analyzed a station blackout occurring during shutdown (refueling) conditions, but for the Grand Gulf plant, a BWR/6 with Mark III containment. These studies help quantify the amount of air that would have to enter the core region to have a significant impact on the severe accident scenario, and demonstrate that one effect, of air ingression is substantial enhancement of ruthenium release. These calculations also show that, while the core clad temperatures rise more quickly due to oxidation with air rather than steam, the core also degrades and relocates more quickly, so that no sustained, enhanced core heatup is predicted to occur with air ingression.

  4. Synthesis and characterization of self-crosslinking fluorinated polyacrylate soap-free latices with core-shell structure

    NASA Astrophysics Data System (ADS)

    Xu, Wei; An, Qiufeng; Hao, Lifen; Zhang, Dan; Zhang, Min

    2013-03-01

    Novel self-crosslinking fluorinated polyacrylate soap-free latices (FMBN) with core-shell structure were synthesized by semicontinuous seeded emulsion polymerization method from dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and N-methylolamide (NMA) in the presence of a polymerizable emulsifier-ammonium allyloxtmethylate nonylphenol ethoxylates sulfate (DNS-86). Effects of the DNS-86 and DFMA amounts on stability and properties of the FMBN emulsions were studied. Besides, the latices and their film were characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (1H NMR) spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analyzer, differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), contact angle goniometer, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. FT-IR spectra and 1H NMR spectrum showed that DFMA successfully participated in soap-free emulsion polymerization and monomers formed the fluorinated acrylate copolymer. The resulted latex particles had the core-shell structure. The films formed from the FMBN latices thus had two Tg. Their thermal stability and Tg of the shell phase increased gradually with augment of DFMA amount in polymer. XPS, AFM and hydrophobicity analyses indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface. This enrichment of fluorine at the film-air interface was more evident after the annealing process. Water contact angles of the FMBN film before and after the annealing process could attain 115.5° and 117.5°, individually.

  5. Experimental Investigation on FRA Diagnosis of Transformer Faults

    NASA Astrophysics Data System (ADS)

    Sano, Takahiro; Miyagi, Katsunori

    The need for economical, reliable and effective delivery of electric power leads to the search for new, efficient and effective methods for diagnosing the high voltage equipments in the industries all over the world. As the average usage period of transformers increases, the necessity to know the internal condition of transformers is increasing. It is therefore critically important to establish monitoring and diagnostic techniques that can perform transformer condition assessment. Frequency response analysis, generally known as FRA, is one of the technologies to diagnose transformers. Using case studies, this paper presents the effectiveness of FRA as measurements for detecting transformer faults. This paper introduces the fact that FRA waveforms have useful information about diagnosis of fault on winding shield and core earths, and that the condition outside transformers can affect frequency response characteristics. The FRA measurement results are further investigated through a simulation study using a computer model.

  6. Transformation of Atlantic Water in the Nansen Basin of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Ivanov, Vladimir; Aksenov, Yevgeny

    2015-04-01

    The joint analysis of recent hydrographic observations and high resolution numerical modelling is presented for the segment of the boundary current between Fram Strait and the Lomonosov Ridge in the Nansen Basin of the Arctic Ocean. The process of the Fram Strait branch of Atlantic Water (FAW) transformation on this route is in the focus of this study. Two specific regions are distinguished, where fast transformation of FAW occurs. The first region is located between northern Svalbard and Franz Joseph Land. This is the place where eastward flow of warm and salty FAW encounters pack ice, which moves towards Fram Strait. Intensive ocean-ice-air interaction leads to rapid heat and salt loss from the upper part of FAW, resulting in formation of surface mixed layer and isolation of the warm FAW core from further direct contact with atmosphere. The second crucial region of FAW transformation is located around Severnaya Zemlya Archipelago. In this region deep warm core of FAW rapidly loses heat and salt as a result of intensive vertical and lateral mixing with the Barents Sea AW branch (BAW), which enters the Nansen Basin through St.Anna Trough, submerges the warm core of FAW and pushes it seaward. Dense water, originating on the north-western shelf of the Laptev Sea, cascades down continental slope and also contributes to cooling and freshening of FAW on its way along the Laptev Sea continental margin. The end product of the transformation process in the Laptev Sea is a new water mass, which includes FAW, BAW and shelf water fractions. This water occupies the depth range 200-1000 m. It is characterised by the positive temperature and by the absence of local maxima on salinity vertical profile. Sitting on the continental slope makes this water mass quite mobile and therefore - the major candidate to reach Canadian Basin. This perspective is less likely for the original FAW. In the Laptev Sea this water is detached off the continental margin and is likely to recirculate

  7. Pressure Core Characterization

    NASA Astrophysics Data System (ADS)

    Santamarina, J. C.

    2014-12-01

    Natural gas hydrates form under high fluid pressure and low temperature, and are found in permafrost, deep lakes or ocean sediments. Hydrate dissociation by depressurization and/or heating is accompanied by a multifold hydrate volume expansion and host sediments with low permeability experience massive destructuration. Proper characterization requires coring, recovery, manipulation and testing under P-T conditions within the stability field. Pressure core technology allows for the reliable characterization of hydrate bearing sediments within the stability field in order to address scientific and engineering needs, including the measurement of parameters used in hydro-thermo-mechanical analyses, and the monitoring of hydrate dissociation under controlled pressure, temperature, effective stress and chemical conditions. Inherent sampling effects remain and need to be addressed in test protocols and data interpretation. Pressure core technology has been deployed to study hydrate bearing sediments at several locations around the world. In addition to pressure core testing, a comprehensive characterization program should include sediment analysis, testing of reconstituted specimens (with and without synthetic hydrate), and in situ testing. Pressure core characterization technology can be used to study other gas-charged formations such as deep sea sediments, coal bed methane and gas shales.

  8. Air and water cooled modulator

    DOEpatents

    Birx, Daniel L.; Arnold, Phillip A.; Ball, Don G.; Cook, Edward G.

    1995-01-01

    A compact high power magnetic compression apparatus and method for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air.

  9. Air and water cooled modulator

    DOEpatents

    Birx, D.L.; Arnold, P.A.; Ball, D.G.; Cook, E.G.

    1995-09-05

    A compact high power magnetic compression apparatus and method are disclosed for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air. 9 figs.

  10. [Air pollution].

    PubMed

    Bauters, Christophe; Bauters, Gautier

    2016-01-01

    Short-term exposure to particulate matter (PM) air pollution is associated with an increased cardiovascular mortality. Chronic exposure to PM is also associated with cardiovascular risk. Myocardial infarction and heart failure are the most common cardiovascular events associated with PM pollution. The pathophysiological mechanisms related to PM pollution are inflammation, thrombosis, vasomotion abnormalities, progression of atherosclerosis, increased blood pressure, and cardiac remodeling. A decrease in PM exposure may be particularly beneficial in subjects with a high cardiovascular risk. PMID:26547674

  11. Residential market transformation: National and regional indicators

    SciTech Connect

    Van Wie McGrory, Laura L.; McNamara, Maureen; Suozzo, Margaret

    2000-06-01

    A variety of programs are underway to address market barriers to the adoption of energy-efficient residential technologies and practices. Most are administered by utilities, states, or regions that rely on the Energy Star as a consistent platform for program marketing and messaging. This paper reviews regional and national market transformation activities for three key residential end-uses -- air conditioning, clothes washing, and lighting -- characterizing current and ongoing programs; reporting on progress; identifying market indicators; and discussing implications.

  12. Air filtering device

    SciTech Connect

    Backus, A.L.

    1992-07-28

    This patent describes a room air cleaning device. It comprises: a box housing having an air inlet and an air outlet provided therein; a vertical baffle coupled to the box housing opposite the air outlet and spaced form the box housing such that an air egress outlet is formed between the vertical baffle and the box housing; air cleansing means substantially disposed within the box housing and cleansing air passing into the inlet and out of the air egress outlet; a fan disposed within the box housing, the fan providing air movement through the air inlet and the air egress outlet; wherein air exits the room air cleaning device through the air egress outlet as a vertical plane of moving air; and wherein formation of the vertical plane of moving air contributes to the formation of a low pressure area drawing impure air toward the air inlet.

  13. Toroidal transformer design program with application to inverter circuitry

    NASA Technical Reports Server (NTRS)

    Dayton, J. A., Jr.

    1972-01-01

    Estimates of temperature, weight, efficiency, regulation, and final dimensions are included in the output of the computer program for the design of transformers for use in the basic parallel inverter. The program, written in FORTRAN 4, selects a tape wound toroidal magnetic core and, taking temperature, materials, core geometry, skin depth, and ohmic losses into account, chooses the appropriate wire sizes and number of turns for the center tapped primary and single secondary coils. Using the program, 2- and 4-kilovolt-ampere transformers are designed for frequencies from 200 to 3200 Hz and the efficiency of a basic transistor inverter is estimated.

  14. Lateral distribution of electrons of air showers

    NASA Technical Reports Server (NTRS)

    Asakimori, K.; Maeda, T.; Kameda, T.; Mizushima, K.; Misaki, Y.

    1985-01-01

    The lateral distribution of electrons (LDE) of the air showers of size 10 to the 5th power to 10 to the 6th power was studied within one MU. It was found that the LDE of the air showers observed is well represented by NKG function except for vicinity of the core. It was also found that LDE measured by thin scintillators does not differ from that measured by thick ones of 50mm thickness.

  15. Earth's core iron

    NASA Astrophysics Data System (ADS)

    Geophysicist J. Michael Brown of Texas A & M University noted recently at the Spring AGU Meeting in Baltimore that the structure and phase of metallic iron at pressures of the earth's inner core (approximately 3.3 Mbar) could have great significance in defining geometrical aspects of the core itself. Brown worked at the Los Alamos Scientific Laboratory with R.B. McQueen to redetermine the phase relations of metallic iron in a series of new shock-wave experiments. They found the melting point of iron at conditions equal to those at the boundary of the earth's outer (liquid) and inner (solid) cores to be 6000°±500°C (Geophysical Research Letters, 7, 533-536, 1980).

  16. Molten core retention assembly

    DOEpatents

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  17. Mars' Inner Core

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This figure shows a cross-section of the planet Mars revealing an inner, high density core buried deep within the interior. Dipole magnetic field lines are drawn in blue, showing the global scale magnetic field that one associates with dynamo generation in the core. Mars must have one day had such a field, but today it is not evident. Perhaps the energy source that powered the early dynamo has shut down. The differentiation of the planet interior - heavy elements like iron sinking towards the center of the planet - can provide energy as can the formation of a solid core from the liquid.

    The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. JPL is an operating division of California Institute of Technology (Caltech).

  18. Dark matter cores all the way down

    NASA Astrophysics Data System (ADS)

    Read, J. I.; Agertz, O.; Collins, M. L. M.

    2016-07-01

    We use high-resolution simulations of isolated dwarf galaxies to study the physics of dark matter cusp-core transformations at the edge of galaxy formation: M200 = 107-109 M⊙. We work at a resolution (˜4 pc minimum cell size; ˜250 M⊙ per particle) at which the impact from individual supernovae explosions can be resolved, becoming insensitive to even large changes in our numerical `sub-grid' parameters. We find that our dwarf galaxies give a remarkable match to the stellar light profile; star formation history; metallicity distribution function; and star/gas kinematics of isolated dwarf irregular galaxies. Our key result is that dark matter cores of size comparable to the stellar half-mass radius r1/2 always form if star formation proceeds for long enough. Cores fully form in less than 4 Gyr for the M200 = 108 M⊙ and ˜14 Gyr for the 109 M⊙ dwarf. We provide a convenient two parameter `CORENFW' fitting function that captures this dark matter core growth as a function of star formation time and the projected stellar half-mass radius. Our results have several implications: (i) we make a strong prediction that if Λcold dark matter is correct, then `pristine' dark matter cusps will be found either in systems that have truncated star formation and/or at radii r > r1/2; (ii) complete core formation lowers the projected velocity dispersion at r1/2 by a factor of ˜2, which is sufficient to fully explain the `too-big-to-fail problem'; and (iii) cored dwarfs will be much more susceptible to tides, leading to a dramatic scouring of the sub-halo mass function inside galaxies and groups.

  19. The Potential of Digital Technologies to Support Literacy Instruction Relevant to the Common Core State Standards

    ERIC Educational Resources Information Center

    Hutchison, Amy C.; Colwell, Jamie

    2014-01-01

    Digital tools have the potential to transform instruction and promote literacies outlined in the Common Core State Standards. Empirical research is examined to illustrate this potential in grades 6-12 instruction.

  20. Biochemical transformation of coals

    DOEpatents

    Lin, M.S.; Premuzic, E.T.

    1999-03-23

    A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed. 7 figs.

  1. Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Understanding the global atmospheric changes is difficult with today's current technology. However, with high resolution and nearly continuous observations from a satellite, it's possible to transform our understanding of the atmosphere. To enable the next generation of atmospheric science, a new class of orbiting atmospheric sensors is being developed. The foundation of this advanced concept is the Fourier Transform Spectrometer, or FTS.

  2. Deployment & Market Transformation (Brochure)

    SciTech Connect

    Not Available

    2012-04-01

    NREL's deployment and market transformation (D and MT) activities encompass the laboratory's full range of technologies, which span the energy efficiency and renewable energy spectrum. NREL staff educates partners on how they can advance sustainable energy applications and also provides clients with best practices for reducing barriers to innovation and market transformation.

  3. Genetic Transformation of Bacteria.

    ERIC Educational Resources Information Center

    Moss, Robert.

    1991-01-01

    An activity in which students transform an ampicillin-sensitive strain of E. coli with a plasmid containing a gene for ampicillin resistance is described. The procedure for the preparation of competent cells and the transformation of competent E. coli is provided. (KR)

  4. Support Principals, Transform Schools

    ERIC Educational Resources Information Center

    Aguilar, Elena; Goldwasser, Davina; Tank-Crestetto, Kristina

    2011-01-01

    The Transformational Coaching Team in Oakland Unified School District provides differentiated, sustained, job-embedded support to the district's school leaders. In this article, members of the team describe how they work with principals to transform the culture of schools. Student achievement data show above-average improvement in schools in which…

  5. Two Different Squeeze Transformations

    NASA Technical Reports Server (NTRS)

    Han, D. (Editor); Kim, Y. S.

    1996-01-01

    Lorentz boosts are squeeze transformations. While these transformations are similar to those in squeezed states of light, they are fundamentally different from both physical and mathematical points of view. The difference is illustrated in terms of two coupled harmonic oscillators, and in terms of the covariant harmonic oscillator formalism.

  6. A Transformation Called "Twist"

    ERIC Educational Resources Information Center

    Hwang, Daniel

    2010-01-01

    The transformations found in secondary mathematics curriculum are typically limited to stretches and translations (e.g., ACARA, 2010). Advanced students may find the transformation, twist, to be of further interest. As most available resources are written for professional-level readers, this article is intended to be an introduction accessible to…

  7. Disc piezoelectric ceramic transformers.

    PubMed

    Erhart, Jirií; Půlpán, Petr; Doleček, Roman; Psota, Pavel; Lédl, Vít

    2013-08-01

    In this contribution, we present our study on disc-shaped and homogeneously poled piezoelectric ceramic transformers working in planar-extensional vibration modes. Transformers are designed with electrodes divided into wedge, axisymmetrical ring-dot, moonie, smile, or yin-yang segments. Transformation ratio, efficiency, and input and output impedances were measured for low-power signals. Transformer efficiency and transformation ratio were measured as a function of frequency and impedance load in the secondary circuit. Optimum impedance for the maximum efficiency has been found. Maximum efficiency and no-load transformation ratio can reach almost 100% and 52 for the fundamental resonance of ring-dot transformers and 98% and 67 for the second resonance of 2-segment wedge transformers. Maximum efficiency was reached at optimum impedance, which is in the range from 500 Ω to 10 kΩ, depending on the electrode pattern and size. Fundamental vibration mode and its overtones were further studied using frequency-modulated digital holographic interferometry and by the finite element method. Complementary information has been obtained by the infrared camera visualization of surface temperature profiles at higher driving power. PMID:25004532

  8. Transformative Learning and Identity

    ERIC Educational Resources Information Center

    Illeris, Knud

    2014-01-01

    Transformative learning has usually been defined as transformations of meaning perspectives, frames of reference, and habits of mind--as proposed initially by Jack Mezirow. However, several authors have found this definition too narrow and too cognitively oriented, and Mezirow has later emphasized that emotional and social conditions are also…

  9. Adaptive Wavelet Transforms

    SciTech Connect

    Szu, H.; Hsu, C.

    1996-12-31

    Human sensors systems (HSS) may be approximately described as an adaptive or self-learning version of the Wavelet Transforms (WT) that are capable to learn from several input-output associative pairs of suitable transform mother wavelets. Such an Adaptive WT (AWT) is a redundant combination of mother wavelets to either represent or classify inputs.

  10. Direct current transformer

    NASA Technical Reports Server (NTRS)

    Khanna, S. M.; Urban, E. W. (Inventor)

    1979-01-01

    A direct current transformer in which the primary consists of an elongated strip of superconductive material, across the ends of which is direct current potential is described. Parallel and closely spaced to the primary is positioned a transformer secondary consisting of a thin strip of magnetoresistive material.

  11. Transformation-optical Fan-beam Synthesis

    PubMed Central

    Yang, Rui; Kong, Xianghui; Wang, Hui; Su, He; Lei, Zhenya; Wang, Jing; Zhang, Aofang; Chen, Lei

    2016-01-01

    Gradient-index dielectric lenses are generated based on the coordinate transformation by compressing the homogeneous air spaces quasi-conformally towards and outwards the primary source. The three-dimensional modeling is then performed through revolving the prescribed transformational media 180 degrees around the focal point to reach the architecture of barrel-vaults. It is found that all these two- and three-dimensional transformation-optical designs are capable of producing fan-beams efficiently over a broad frequency range with their main lobes possessing the narrow beamwidth in one dimension and the wide beamwidth in the other, while having the great ability of the wide angular scanning. Finally, we propose to construct such four types of fan-beam lenses through multiple-layered dielectrics with non-uniformed perforations and experimentally demonstrate their excellent performances in the fan-beam synthesis. PMID:26847048

  12. Transformation-optical Fan-beam Synthesis

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Kong, Xianghui; Wang, Hui; Su, He; Lei, Zhenya; Wang, Jing; Zhang, Aofang; Chen, Lei

    2016-02-01

    Gradient-index dielectric lenses are generated based on the coordinate transformation by compressing the homogeneous air spaces quasi-conformally towards and outwards the primary source. The three-dimensional modeling is then performed through revolving the prescribed transformational media 180 degrees around the focal point to reach the architecture of barrel-vaults. It is found that all these two- and three-dimensional transformation-optical designs are capable of producing fan-beams efficiently over a broad frequency range with their main lobes possessing the narrow beamwidth in one dimension and the wide beamwidth in the other, while having the great ability of the wide angular scanning. Finally, we propose to construct such four types of fan-beam lenses through multiple-layered dielectrics with non-uniformed perforations and experimentally demonstrate their excellent performances in the fan-beam synthesis.

  13. From cusps to cores: a stochastic model

    NASA Astrophysics Data System (ADS)

    El-Zant, Amr A.; Freundlich, Jonathan; Combes, Françoise

    2016-09-01

    The cold dark matter model of structure formation faces apparent problems on galactic scales. Several threads point to excessive halo concentration, including central densities that rise too steeply with decreasing radius. Yet, random fluctuations in the gaseous component can `heat' the centres of haloes, decreasing their densities. We present a theoretical model deriving this effect from first principles: stochastic variations in the gas density are converted into potential fluctuations that act on the dark matter; the associated force correlation function is calculated and the corresponding stochastic equation solved. Assuming a power-law spectrum of fluctuations with maximal and minimal cutoff scales, we derive the velocity dispersion imparted to the halo particles and the relevant relaxation time. We further perform numerical simulations, with fluctuations realized as a Gaussian random field, which confirm the formation of a core within a time-scale comparable to that derived analytically. Non-radial collective modes enhance the energy transport process that erases the cusp, though the parametrizations of the analytical model persist. In our model, the dominant contribution to the dynamical coupling driving the cusp-core transformation comes from the largest scale fluctuations. Yet, the efficiency of the transformation is independent of the value of the largest scale and depends weakly (linearly) on the power-law exponent; it effectively depends on two parameters: the gas mass fraction and the normalization of the power spectrum. This suggests that cusp-core transformations observed in hydrodynamic simulations of galaxy formation may be understood and parametrized in simple terms, the physical and numerical complexities of the various implementations notwithstanding.

  14. New directions: Air pollution challenges for developing megacities like Delhi

    NASA Astrophysics Data System (ADS)

    Kumar, Prashant; Khare, Mukesh; Harrison, Roy M.; Bloss, William J.; Lewis, Alastair C.; Coe, Hugh; Morawska, Lidia

    2015-12-01

    Most major cities around the world experience periods of elevated air pollution levels, which exceed international health-based air quality standards (Kumar et al., 2013). Although it is a global problem, some of the highest air pollution levels are found in rapidly expanding cities in India and China. The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies. We focus here on Delhi, one of the largest global population centres, which faces particular air pollution challenges, now and in the future.

  15. Facile access to thermoresponsive filomicelles with tuneable cores.

    PubMed

    Truong, Nghia P; Quinn, John F; Anastasaki, Athina; Haddleton, David M; Whittaker, Michael R; Davis, Thomas P

    2016-03-15

    We report a novel library of filomicelles in water comprising either polystyrene or various polymethacrylate cores prepared via temperature-induced morphological transformation (TIMT). The nanoworms demonstrate reproducibly uniform morphology while exhibiting a broad range of glass transition temperatures, high stability in buffer, and the ability to form smart reversible thermoresponsive gels. PMID:26931090

  16. Arguments for and against the Common Core State Standards

    ERIC Educational Resources Information Center

    VanTassel-Baska, Joyce

    2015-01-01

    This article identifies the arguments for and against the common core state standards in English language arts and mathematics. Although the standards need to be differentiated for gifted students, the author suggests that these standards may offer a way to transform education in the classroom, so that all students are able to fulfill their…

  17. The Value of Core Principles in the Age of Change

    ERIC Educational Resources Information Center

    McCain, Adelric R.

    2009-01-01

    As the author reflects on CES and its groundbreaking, significant work over the past 25 years, he is regularly reminded of the importance of the core guiding principles, even as the educational landscape changes. In his 10 short years of teaching, he has witnessed many transformations, alterations, and modifications in education. He has been…

  18. Nanocrystallized cores for ground fault circuit breakers

    NASA Astrophysics Data System (ADS)

    Waeckerlé, T.; Fraisse, H.; Gautard, D.

    2003-01-01

    Nanocrystallized cores for ground fault circuit breaker (GFCB) can be manufactured for low exciting fields such as 2 A/m, with a low sensitivity to varied pulsed waveform currents (Δ Bdyn/Δ Bsin⩾0.85) and Δ B>0.1 T. On the basis of an experimental and statistical study, it is shown that these GFCB working features are mainly correlated to the remanent induction Br. The results allow a well-controlled design of compact and reliable GFCB transformers.

  19. Nuclear Physics in Core-Collapse Supernovae

    SciTech Connect

    Liebendoerfer, Matthias; Fischer, T.; Froelich, C.; Hix, William Raphael; Langanke, Karlheinz; Martinez-Pinedo, Gabriel; Mezzacappa, Anthony; Scheidegger, Simon; Thielemann, Friedrich-Karl W.; Whitehouse, Stuart

    2008-01-01

    Core-collapse and the launch of a supernova explosion form a very short episode of few seconds in the evolution of a massive star, during which an enormous gravitational energy of several times 1053 erg is transformed into observable neutrino-, kinetic-, and electromagnetic radiation energy. We emphasize the wide range of matter conditions that prevail in a supernova event and sort the conditions into distinct regimes in the density and entropy phase diagram to briefly discuss their different impact on the neutrino signal, gravitational wave emission, and ejecta.

  20. Analytical analysis of particle-core dynamics

    SciTech Connect

    Batygin, Yuri K

    2010-01-01

    Particle-core interaction is a well-developed model of halo formation in high-intensity beams. In this paper, we present an analytical solution for averaged, single particle dynamics, around a uniformly charged beam. The problem is analyzed through a sequence of canonical transformations of the Hamiltonian, which describes nonlinear particle oscillations. A closed form expression for maximum particle deviation from the axis is obtained. The results of this study are in good agreement with numerical simulations and with previously obtained data.

  1. NUCLEAR REACTOR CORE DESIGN

    DOEpatents

    Mahlmeister, J.E.; Peck, W.S.; Haberer, W.V.; Williams, A.C.

    1960-03-22

    An improved core design for a sodium-cooled, graphitemoderated nuclear reactor is described. The improved reactor core comprises a number of blocks of moderator material, each block being in the shape of a regular prism. A number of channels, extending the length of each block, are disposed around the periphery. When several blocks are placed in contact to form the reactor core, the channels in adjacent blocks correspond with each other to form closed conduits extending the length of the core. Fuel element clusters are disposed in these closed conduits, and liquid coolant is forced through the annulus between the fuel cluster and the inner surface of the conduit. In a preferred embodiment of the invention, the moderator blocks are in the form of hexagonal prisms with longitudinal channels cut into the corners of the hexagon. The main advantage of an "edge-loaded" moderator block is that fewer thermal neutrons are absorbed by the moderator cladding, as compared with a conventional centrally loaded moderator block.

  2. Theory of core excitons

    SciTech Connect

    Dow, J. D.; Hjalmarson, H. P.; Sankey, O. F.; Allen, R. E.; Buettner, H.

    1980-01-01

    The observation of core excitons with binding energies much larger than those of the valence excitons in the same material has posed a long-standing theoretical problem. A proposed solution to this problem is presented, and Frenkel excitons and Wannier excitons are shown to coexist naturally in a single material. (GHT)

  3. Some Core Contested Concepts

    ERIC Educational Resources Information Center

    Chomsky, Noam

    2015-01-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and…

  4. Authentic to the Core

    ERIC Educational Resources Information Center

    Kukral, Nicole; Spector, Stacy

    2012-01-01

    When educators think about what makes learning relevant to students, often they narrow their thinking to electives or career technical education. While these provide powerful opportunities for students to make relevant connections to their learning, they can also create authentic experiences in the core curriculum. In the San Juan Unified School…

  5. From Context to Core

    ERIC Educational Resources Information Center

    Campus Technology, 2008

    2008-01-01

    At Campus Technology 2008, Arizona State University Technology Officer Adrian Sannier mesmerized audiences with his mandate to become more efficient by doing only the "core" tech stuff--and getting someone else to slog through the context. This article presents an excerpt from Sannier's hour-long keynote address at Campus Technology '08. Sannier…

  6. Core Directions in HRD.

    ERIC Educational Resources Information Center

    1996

    This document consists of four papers presented at a symposium on core directions in human resource development (HRD) moderated by Verna Willis at the 1996 conference of the Academy of Human Resource Development. "Reengineering the Organizational HRD Function: Two Case Studies" (Neal Chalofsky) reports an action research study in which the…

  7. A Multidisciplinary Core Curriculum.

    ERIC Educational Resources Information Center

    Jordan, Trace

    2002-01-01

    Describes New York University's commitment to general mathematics and science education for undergraduate students, embodied in the College of Arts and Science's core curriculum, the Morse Academic Plan, which includes a three-course sequence, Foundations of Scientific Inquiry, specifically designed for non-majors. (EV)

  8. The Tom Core Complex

    PubMed Central

    Ahting, Uwe; Thun, Clemens; Hegerl, Reiner; Typke, Dieter; Nargang, Frank E.; Neupert, Walter; Nussberger, Stephan

    1999-01-01

    Translocation of nuclear-encoded preproteins across the outer membrane of mitochondria is mediated by the multicomponent transmembrane TOM complex. We have isolated the TOM core complex of Neurospora crassa by removing the receptors Tom70 and Tom20 from the isolated TOM holo complex by treatment with the detergent dodecyl maltoside. It consists of Tom40, Tom22, and the small Tom components, Tom6 and Tom7. This core complex was also purified directly from mitochondria after solubilization with dodecyl maltoside. The TOM core complex has the characteristics of the general insertion pore; it contains high-conductance channels and binds preprotein in a targeting sequence-dependent manner. It forms a double ring structure that, in contrast to the holo complex, lacks the third density seen in the latter particles. Three-dimensional reconstruction by electron tomography exhibits two open pores traversing the complex with a diameter of ∼2.1 nm and a height of ∼7 nm. Tom40 is the key structural element of the TOM core complex. PMID:10579717

  9. The Uncommon Core

    ERIC Educational Resources Information Center

    Ohler, Jason

    2013-01-01

    This author contends that the United States neglects creativity in its education system. To see this, he states, one may look at the Common Core State Standards. If one searches the English Language Arts and Literacy standards for the words "creative," "innovative," and "original"--and any associated terms, one will find scant mention of the words…

  10. University City Core Plan.

    ERIC Educational Resources Information Center

    Philadelphia City Planning Commission, PA.

    A redevelopment plan for an urban core area of about 300 acres was warranted by--(1) unsuitable building conditions, (2) undesirable land usage, and (3) faulty traffic circulation. The plan includes expansion of two universities and creation of a regional science center, high school, and medical center. Guidelines for proposed land use and zoning…

  11. Ultrasonic Drilling and Coring

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    1998-01-01

    A novel drilling and coring device, driven by a combination, of sonic and ultrasonic vibration, was developed. The device is applicable to soft and hard objects using low axial load and potentially operational under extreme conditions. The device has numerous potential planetary applications. Significant potential for commercialization in construction, demining, drilling and medical technologies.

  12. Looking for Core Values

    ERIC Educational Resources Information Center

    Carter, Margie

    2010-01-01

    People who view themselves as leaders, not just managers or teachers, are innovators who focus on clarifying core values and aligning all aspects of the organization with these values to grow their vision. A vision for an organization can't be just one person's idea. Visions grow by involving people in activities that help them name and create…

  13. Life from the core

    NASA Astrophysics Data System (ADS)

    Doglioni, Carlo; Coleman, Max; Pignatti, Johannes; Glassmeier, Karl-Heinz

    2010-05-01

    Life on Earth is the result of the chaotic combination of several independent chemical and physical parameters. One of them is the shield from ionizing radiation exerted by the atmosphere and the Earth's magnetic field. We hypothesise that the first few billion years of the Earth's history, dominated by bacteria, were characterized by stronger ionizing radiation. Bacteria can survive under such conditions better than any other organism. During the Archean and early Proterozoic the shield could have been weaker, allowing the development of only a limited number of species, more resistant to the external radiation. The Cambrian explosion of life could have been enhanced by the gradual growth of the solid inner core, which was not existent possibly before 1 Ga. The cooling of the Earth generated the solidification of the iron alloy in the center of the planet. As an hypothesis, before the crystallization of the core, the turbulence in the liquid core could have resulted in a lower or different magnetic field from the one we know today, being absent the relative rotation between inner and external core.

  14. The Earth's Core.

    ERIC Educational Resources Information Center

    Jeanloz, Raymond

    1983-01-01

    The nature of the earth's core is described. Indirect evidence (such as that determined from seismological data) indicates that it is an iron alloy, solid toward its center but otherwise liquid. Evidence also suggests that it is the turbulent flow of the liquid that generates the earth's magnetic field. (JN)

  15. Navagating the Common Core

    ERIC Educational Resources Information Center

    McShane, Michael Q.

    2014-01-01

    This article presents a debate over the Common Core State Standards Initiative as it has rocketed to the forefront of education policy discussions around the country. The author contends that there is value in having clear cross state standards that will clarify the new online and blended learning that the growing use of technology has provided…

  16. Resolving Supercritical Orion Cores

    NASA Astrophysics Data System (ADS)

    Li, Di; Chapman, N.; Goldsmith, P.; Velusamy, T.

    2009-01-01

    The theoretical framework for high mass star formation (HMSF) is unclear. Observations reveal a seeming dichotomy between high- and low-mass star formation, with HMSF occurring only in Giant Molecular Clouds (GMC), mostly in clusters, and with higher star formation efficiencies than low-mass star formation. One crucial constraint to any theoretical model is the dynamical state of massive cores, in particular, whether a massive core is in supercritical collapse. Based on the mass-size relation of dust emission, we select likely unstable targets from a sample of massive cores (Li et al. 2007 ApJ 655, 351) in the nearest GMC, Orion. We have obtained N2H+ (1-0) maps using CARMA with resolution ( 2.5", 0.006 pc) significantly better than existing observations. We present observational and modeling results for ORI22. By revealing the dynamic structure down to Jeans scale, CARMA data confirms the dominance of gravity over turbulence in this cores. This work was performed by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  17. Nucleosome Core Particle

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Nucleosome Core Particle grown on STS-81. The fundamental structural unit of chromatin and is the basis for organization within the genome by compaction of DNA within the nucleus of the cell and by making selected regions of chromosomes available for transcription and replication. Principal Investigator's are Dr. Dan Carter and Dr. Gerard Bunick of New Century Pharmaceuticals.

  18. Renewing the Core Curriculum

    ERIC Educational Resources Information Center

    Lawson, Hal A.

    2007-01-01

    The core curriculum accompanied the development of the academic discipline with multiple names such as Kinesiology, Exercise and Sport Science, and Health and Human Performance. It provides commonalties for undergraduate majors. It is timely to renew this curriculum. Renewal involves strategic reappraisals. It may stimulate change or reaffirm the…

  19. A World Core Curriculum.

    ERIC Educational Resources Information Center

    Muller, Robert

    1993-01-01

    Robert Muller's "World Core Curriculum" is designed to give children: a good picture of planet Earth and the universe; a correct picture of the commonalities and diversity of the human family; an accurate picture of the time period into which they are born; and a sense of their own importance and the role that they can play in society. (MDM)

  20. Core Competencies. SPEC Kit.

    ERIC Educational Resources Information Center

    McNeil, Beth, Comp.

    2002-01-01

    This SPEC (Systems and Procedures Exchange Center) Kit presents the results of a survey of Association of Research Libraries (ARL) member libraries designed to investigate the status of core competencies (i.e., the skills, knowledge, abilities, and attributes that employees across an organization are expected to have to contribute successfully…