10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 2 2012-01-01 2012-01-01 false Performance objectives for the geologic repository after permanent closure. 63.113 Section 63.113 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH... and an engineered barrier system. (b) The engineered barrier system must be designed so that, working...

Performance of high power S-band klystrons focused with permanent magnet

NASA Astrophysics Data System (ADS)

Fukuda, S.; Shidara, T.; Saito, Y.; Hanaki, H.; Nakao, K.; Homma, H.; Anami, S.; Tanaka, J.

1987-02-01

Performance of high power S-band klystrons focused with permanent magnet is presented. The axial magnetic field distribution and the transverse magnetic field play an important role in the tube performance. Effects of the reversal field in the collector and the cathode-anode region are discussed precisely. It is also shown that the tube efficiency is strongly affected with the residual transverse magnetic field. The allowable transverse field is less than 0.3 percent of the longitudinal field in the entire RF interaction region of the klystron.

New Cogging Torque Reduction Methods for Permanent Magnet Machine

NASA Astrophysics Data System (ADS)

Bahrim, F. S.; Sulaiman, E.; Kumar, R.; Jusoh, L. I.

2017-08-01

Permanent magnet type motors (PMs) especially permanent magnet synchronous motor (PMSM) are expanding its limbs in industrial application system and widely used in various applications. The key features of this machine include high power and torque density, extending speed range, high efficiency, better dynamic performance and good flux-weakening capability. Nevertheless, high in cogging torque, which may cause noise and vibration, is one of the threat of the machine performance. Therefore, with the aid of 3-D finite element analysis (FEA) and simulation using JMAG Designer, this paper proposed new method for cogging torque reduction. Based on the simulation, methods of combining the skewing with radial pole pairing method and skewing with axial pole pairing method reduces the cogging torque effect up to 71.86% and 65.69% simultaneously.

A permanent-magnet rotor for a high-temperature superconducting bearing

NASA Astrophysics Data System (ADS)

Mulcahy, T. M.; Hull, J. R.; Uherka, K. L.; Abboud, R. G.; Wise, J. H.; Carnegie, D. W.

1995-06-01

Design, fabrication, and performance, of a 1/3-m dia., 10-kg flywheel rotor with only one bearing is discussed. To achieve low-loss energy storage, the rotor's segmented-ring permanent-magnet (PM) is optimized for levitation and circumferential homogeneity. The magnet's carbon composite bands enable practical energy storage.

A latest developed all permanent magnet ECRIS for atomic physics research at IMP

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

Sun, L.T.; Zhao, H.W.; Zhang, Z.M.

2006-03-15

Electron cyclotron resonance (ECR) ion sources have been used for atomic physics research for a long time. With the development of atomic physics research in the Institute of Modern Physics (IMP), additional high performance experimental facilities are required. A 300 kV high voltage (HV) platform has been under construction since 2003, and an all permanent magnet ECR ion source is supposed to be put on the platform. Lanzhou all permanent magnet ECR ion source No. 2 (LAPECR2) is a latest developed all permanent magnet ECRIS. It is a 900 kg weight and null-set 650 mmx562 mm outer dimension (magnetic body)more » ion source. The injection magnetic field of the source is 1.28 T and the extraction magnetic field is 1.07 T. This source is designed to be running at 14.5 GHz. The high magnetic field inside the plasma chamber enables the source to give good performances at 14.5 GHz. LAPECR2 source is now under commissioning in IMP. In this article, the typical parameters of the source LAPECR2 are listed, and the typical results of the preliminary commissioning are presented.« less

Experimental Performance Evaluation of a High Speed Permanent Magnet Synchronous Motor and Drive for a Flywheel Application at Different Frequencies

NASA Technical Reports Server (NTRS)

Nagorny, Aleksandr S.; Jansen, Ralph H.; Kankam, M. David

2007-01-01

This paper presents the results of an experimental performance characterization study of a high speed, permanent magnet motor/generator (M/G) and drive applied to a flywheel module. Unlike the conventional electric machine the flywheel M/G is not a separated unit; its stator and rotor are integrated into a flywheel assembly. The M/G rotor is mounted on a flywheel rotor, which is magnetically levitated and sealed within a vacuum chamber during the operation. Thus, it is not possible to test the M/G using direct load measurements with a dynamometer and torque transducer. Accordingly, a new in-situ testing method had to be developed. The paper describes a new flywheel M/G and drive performance evaluation technique, which allows the estimation of the losses, efficiency and power quality of the flywheel high speed permanent magnet M/G, while working in vacuum, over wide frequency and torque ranges. This method does not require any hardware modification nor any special addition to the test rig. This new measurement technique is useful for high-speed applications, when applying an external load is technically difficult.

Dynamic model tracking design for low inertia, high speed permanent magnet ac motors.

PubMed

Stewart, P; Kadirkamanathan, V

2004-01-01

Permanent magnet ac (PMAC) motors have existed in various configurations for many years. The advent of rare-earth magnets and their associated highly elevated levels of magnetic flux makes the permanent magnet motor attractive for many high performance applications from computer disk drives to all electric racing cars. The use of batteries as a prime storage element carries a cost penalty in terms of the unladen weight of the vehicle. Minimizing this cost function requires the minimum electric motor size and weight to be specified, while still retaining acceptable levels of output torque. This tradeoff can be achieved by applying a technique known as flux weakening which will be investigated in this paper. The technique allows the speed range of a PMAC motor to be greatly increased, giving a constant power range of more than 4:1. A dynamic model reference controller is presented which has advantages in ease of implementation, and is particularly suited to dynamic low inertia applications such as clutchless gear changing in high performance electric vehicles. The benefits of this approach are to maximize the torque speed envelope of the motor, particularly advantageous when considering low inertia operation. The controller is examined experimentally, confirming the predicted performance.

Shear wave EMAT thickness measurements of low carbon steel at 450 °C without cooling

NASA Astrophysics Data System (ADS)

Lunn, Natasha; Potter, Mark; Dixon, Steve

2017-02-01

Performing high temperature online inspection without plant shutdown is highly desirable, yet, development of portable or permanently installed high temperature ultrasonic sensors, without the need for sample surface preparation, remains a key challenge. Low carbon steel pipelines operating at elevated temperatures often develop a magnetostrictive oxide coating (magnetite), which improves electromagnetic acoustic transducer (EMAT) efficiency below the Curie temperature of magnetite (575 °C), via a magnetostrictive mechanism. Coupling the inherent non-contacting nature of EMATs with the enhanced efficiency from a magnetite coating, we are able to continuously operate an uncoded EMAT at elevated temperatures without permanent installation or surface preparation. In this work, a high temperature shear wave EMAT utilizing a high field, high Curie point, permanent magnet has been developed to generate ultrasonic bulk thickness measurements on magnetite coated steel at temperatures of up to 450 °C, without cooling. Relatively high signal-to-noise ratios, in the region of 30 dB for single shot data, have been measured at 450 °C using this technique. The EMAT design and results from high temperature trials, including the performance with change in temperature, sample thickness and EMAT-sample lift-off, are presented here.

Application of a high-energy-density permanent magnet material in underwater systems

NASA Astrophysics Data System (ADS)

Cho, C. P.; Egan, C.; Krol, W. P.

1996-06-01

This paper addresses the application of high-energy-density permanent magnet (PM) technology to (1) the brushless, axial-field PM motor and (2) the integrated electric motor/pump system for under-water applications. Finite-element analysis and lumped parameter magnetic circuit analysis were used to calculate motor parameters and performance characteristics and to conduct tradeoff studies. Compact, efficient, reliable, and quiet underwater systems are attainable with the development of high-energy-density PM material, power electronic devices, and power integrated-circuit technology.

Modeling and simulation of permanent magnet synchronous motor based on neural network control strategy

NASA Astrophysics Data System (ADS)

Luo, Bingyang; Chi, Shangjie; Fang, Man; Li, Mengchao

2017-03-01

Permanent magnet synchronous motor is used widely in industry, the performance requirements wouldn't be met by adopting traditional PID control in some of the occasions with high requirements. In this paper, a hybrid control strategy - nonlinear neural network PID and traditional PID parallel control are adopted. The high stability and reliability of traditional PID was combined with the strong adaptive ability and robustness of neural network. The permanent magnet synchronous motor will get better control performance when switch different working modes according to different controlled object conditions. As the results showed, the speed response adopting the composite control strategy in this paper was faster than the single control strategy. And in the case of sudden disturbance, the recovery time adopting the composite control strategy designed in this paper was shorter, the recovery ability and the robustness were stronger.

Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

NASA Astrophysics Data System (ADS)

Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

2017-09-01

The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

Atomic structure and domain wall pinning in samarium-cobalt-based permanent magnets.

PubMed

Duerrschnabel, M; Yi, M; Uestuener, K; Liesegang, M; Katter, M; Kleebe, H-J; Xu, B; Gutfleisch, O; Molina-Luna, L

2017-07-04

A higher saturation magnetization obtained by an increased iron content is essential for yielding larger energy products in rare-earth Sm 2 Co 17 -type pinning-controlled permanent magnets. These are of importance for high-temperature industrial applications due to their intrinsic corrosion resistance and temperature stability. Here we present model magnets with an increased iron content based on a unique nanostructure and -chemical modification route using Fe, Cu, and Zr as dopants. The iron content controls the formation of a diamond-shaped cellular structure that dominates the density and strength of the domain wall pinning sites and thus the coercivity. Using ultra-high-resolution experimental and theoretical methods, we revealed the atomic structure of the single phases present and established a direct correlation to the macroscopic magnetic properties. With further development, this knowledge can be applied to produce samarium cobalt permanent magnets with improved magnetic performance.Understanding the factors that determine the properties of permanent magnets, which play a central role in many industrial applications, can help in improving their performance. Here, the authors study how changes in the iron content affect the microstructure of samarium cobalt magnets.

Maglev performance of a double-layer bulk high temperature superconductor above a permanent magnet guideway

NASA Astrophysics Data System (ADS)

Deng, Z.; Wang, J.; Zheng, J.; Lin, Q.; Zhang, Y.; Wang, S.

2009-05-01

In order to improve the performance of the present high temperature superconducting (HTS) maglev vehicle system, the maglev performance of single- and double-layer bulk high temperature superconductors (HTSC) was investigated above a permanent magnet guideway (PMG). It is found that the maglev performance of a double-layer bulk HTSC is not a simple addition of each layer's levitation and guidance force. Moreover, the applied magnetic field at the position of the upper layer bulk HTSC is not completely shielded by the lower layer bulk HTSC either. 53.5% of the levitation force and 27.5% of the guidance force of the upper layer bulk HTSC are excited in the double-layer bulk HTSC arrangement in the applied field-cooling condition and working gap, bringing a corresponding improvement of 16.9% and 8.8% to the conventional single-layer bulk HTSC. The present research implies that the cost performance of upper layer bulk HTSC is a little low for the whole HTS maglev system.

Permanent magnet motors

NASA Astrophysics Data System (ADS)

Richter, E.

1984-09-01

The work deals with the design and analysis study for the conceptual design of an economical high efficiency ac motor based on permanent magnets. The design and trade off studies have covered the material considerations, the design tradeoff options as well as transient and steady state performance considerations, and other options. The baseline comparison is the high efficiency induction motor. The permanent magnet (PM) motor must fit into the same frame size and surpass the induction motor on a life cost basis that includes 2.5 years of operation at a 50% duty cycle. It is shown that a motor based upon ferrite magnets does meet the objectives of the program in ratings of up to 25 hp. A 7.5 motor design is carried through the conceptual design stage.

Post-assembly magnetization of a 100 kW high speed permanent magnet rotor.

PubMed

Lv, Yiliang; Wang, Guobin; Li, Liang

2015-03-01

A post-assembly magnetizing fixture has been designed and successfully used to magnetize the rotor of a 100 kW high speed permanent magnet synchronous motor. The rotor is a solid cylinder with outer diameter of 80 mm and total length of 515 mm. The permanent magnet material is samarium-cobalt (Sm2Co17) with saturation magnetizing field of 6 T. The mechanical stability of the magnetizing fixture has been studied as well as the general design methodology. The magnetizing coil is subdivided in order to reduce the electromagnetic force, and the coils are separately reinforced in different ways. The electromagnetic and structural optimization is performed by finite element analysis and verified by experiments.

Design of a transverse-flux permanent-magnet linear generator and controller for use with a free-piston stirling engine

NASA Astrophysics Data System (ADS)

Zheng, Jigui; Huang, Yuping; Wu, Hongxing; Zheng, Ping

2016-07-01

Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system, however it is restricted for large application because of low and complex process. A novel type of cylindrical, non-overlapping, transverse-flux, and permanent-magnet linear motor(TFPLM) is investigated, furthermore, a high power factor and less process complexity structure research is developed. The impact of magnetic leakage factor on power factor is discussed, by using the Finite Element Analysis(FEA) model of stirling engine and TFPLM, an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage factor. The relation between power factor and structure parameter is investigated, and a structure parameter optimization method is proposed taking power factor maximum as a goal. At last, the test bench is founded, starting experimental and generating experimental are performed, and a good agreement of simulation and experimental is achieved. The power factor is improved and the process complexity is decreased. This research provides the instruction to design high-power factor permanent-magnet linear generator.

Effect of pole number and slot number on performance of dual rotor permanent magnet wind power generator using ferrite magnets

NASA Astrophysics Data System (ADS)

Xu, Peifeng; Shi, Kai; Sun, Yuxin; Zhua, Huangqiu

2017-05-01

Dual rotor permanent magnet (DRPM) wind power generator using ferrite magnets has the advantages of low cost, high efficiency, and high torque density. How to further improve the performance and reduce the cost of the machine by proper choice of pole number and slot number is an important problem to be solved when performing preliminarily design a DRPM wind generator. This paper presents a comprehensive performance comparison of a DRPM wind generator using ferrite magnets with different slot and pole number combinations. The main winding factors are calculated by means of the star of slots. Under the same machine volume and ferrite consumption, the flux linkage, back-electromotive force (EMF), cogging torque, output torque, torque pulsation, and losses are investigated and compared using finite element analysis (FEA). The results show that the slot and pole number combinations have an important impact on the generator properties.

Individual differences in object permanence performance at 8 months: locomotor experience and brain electrical activity.

PubMed

Bell, M A; Fox, N A

1997-12-01

This work was designed to investigate individual differences in hands-and-knees crawling and frontal brain electrical activity with respect to object permanence performance in 76 eight-month-old infants. Four groups of infants (one prelocomotor and 3 with varying lengths of hands-and-knees crawling experience) were tested on an object permanence scale in a research design similar to that used by Kermoian and Campos (1988). In addition, baseline EEG was recorded and used as an indicator of brain development, as in the Bell and Fox (1992) longitudinal study. Individual differences in frontal and occipital EEG power and in locomotor experience were associated with performance on the object permanence task. Infants successful at A-not-B exhibited greater frontal EEG power and greater occipital EEG power than unsuccessful infants. In contrast to Kermoian and Campos (1988), who noted that long-term crawling experience was associated with higher performance on an object permanence scale, infants in this study with any amount of hands and knees crawling experience performed at a higher level on the object permanence scale than prelocomotor infants. There was no interaction among brain electrical activity, locomotor experience, and object permanence performance. These data highlight the value of electrophysiological research and the need for a brain-behavior model of object permanence performance that incorporates both electrophysiological and behavioral factors.

30 CFR 817.15 - Casing and sealing of underground openings: Permanent.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS... be designed to prevent access to the mine workings by people, livestock, fish and wildlife, machinery...

Terminal Performance of Lead Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

DTIC Science & Technology

2016-04-04

Terminal Performance of Lead-Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video ELIJAH COURTNEY, AMY...quantified using high speed video . The temporary stretch cavities and permanent wound cavities are also characterized. Two factors tend to re- duce the...Performance of Lead-Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video cavity. In addition, stretching can also

30 CFR 816.15 - Casing and sealing of drilled holes: Permanent.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS... to the mine workings by people, livestock, fish and wildlife, and machinery, and to keep acid or...

Magnetizing technique for permanent magnets by intense static fields generated by HTS bulk magnets: Numerical Analysis

NASA Astrophysics Data System (ADS)

N. Kawasaki; Oka, T.; Fukui, S.; Ogawa, J.; Sato, T.; Terasawa, T.; Itoh, Y.

A demagnetized Nd-Fe-B permanent magnet was scanned in the strong magnetic field space just above the magnetic pole containing a HTS bulk magnet which generates the magnetic field 3.4 T. The magnet sample was subsequently found to be fully magnetized in the open space of the static magnetic fields. The finite element method was carried out for the static field magnetization of a permanent magnet using a HTS bulk magnet. Previously, our research group experimentally demonstrated the possibility of full magnetization of rare earth permanent magnets with high-performance magnetic properties with use of the static field of HTS bulk magnets. In the present study, however, we succeeded for the first time in visualizing the behavior of the magnetizing field of the bulk magnet during the magnetization process and the shape of the magnetic field inside the body being magnetized. By applying this kind of numerical analysis to the magnetization for planned motor rotors which incorporate rare-earth permanent magnets, we hope to study the fully magnetized regions for the new magnetizing method using bulk magnets and to give motor designing a high degree of freedom.

Exact analytical modeling of magnetic vector potential in surface inset permanent magnet DC machines considering magnet segmentation

NASA Astrophysics Data System (ADS)

Jabbari, Ali

2018-01-01

Surface inset permanent magnet DC machine can be used as an alternative in automation systems due to their high efficiency and robustness. Magnet segmentation is a common technique in order to mitigate pulsating torque components in permanent magnet machines. An accurate computation of air-gap magnetic field distribution is necessary in order to calculate machine performance. An exact analytical method for magnetic vector potential calculation in surface inset permanent magnet machines considering magnet segmentation has been proposed in this paper. The analytical method is based on the resolution of Laplace and Poisson equations as well as Maxwell equation in polar coordinate by using sub-domain method. One of the main contributions of the paper is to derive an expression for the magnetic vector potential in the segmented PM region by using hyperbolic functions. The developed method is applied on the performance computation of two prototype surface inset magnet segmented motors with open circuit and on load conditions. The results of these models are validated through FEM method.

Perspectives on Permanent Magnetic Materials for Energy Conversion and Power Generation

NASA Astrophysics Data System (ADS)

Lewis, Laura H.; Jiménez-Villacorta, Félix

2013-01-01

Permanent magnet development has historically been driven by the need to supply larger magnetic energy in ever smaller volumes for incorporation in an enormous variety of applications that include consumer products, transportation components, military hardware, and clean energy technologies such as wind turbine generators and hybrid vehicle regenerative motors. Since the 1960s, the so-called rare-earth "supermagnets," composed of iron, cobalt, and rare-earth elements such as Nd, Pr, and Sm, have accounted for the majority of global sales of high-energy-product permanent magnets for advanced applications. In rare-earth magnets, the transition-metal components provide high magnetization, and the rare-earth components contribute a very large magnetocrystalline anisotropy that donates high resistance to demagnetization. However, at the end of 2009, geopolitical influences created a worldwide strategic shortage of rare-earth elements that may be addressed, among other actions, through the development of rare-earth-free magnetic materials harnessing sources of magnetic anisotropy other than that provided by the rare-earth components. Materials engineering at the micron scale, nanoscale, and Angstrom scales, accompanied by improvements in the understanding and characterization of nanoscale magnetic phenomena, is anticipated to result in new types of permanent magnetic materials with superior performance.

A study of flux control for high-efficiency speed control of variable flux permanent magnet motor

NASA Astrophysics Data System (ADS)

Kim, Young Hyun; Lee, Seong Soo; Lee, Jung Ho

2018-05-01

In this study, we evaluate the performance of permanent magnets (PMs). The efficiency of attraction in the high speed region was studied using the variable flux memory motor (VFMM). It is presented in order to analyze the magnetic characteristics of PMs, using the second quadrant plan data with re- and de-magnetization. In addition, this study focuses on the evaluation of operational characteristics relative to the magnetizing directions according to the d-axis currents, by using one of the finite element solutions. The feasibility of application for the VFMM has been experimentally demonstrated.

Object permanence in common marmosets (Callithrix jacchus).

PubMed

Mendes, Natacha; Huber, Ludwig

2004-03-01

A series of 9 search tasks corresponding to the Piagetian Stages 3-6 of object permanence were administered to 11 common marmosets (Callithrix jacchus). Success rates varied strongly among tasks and marmosets, but the performances of most subjects were above chance level on the majority of tasks of visible and invisible displacements. Although up to 24 trials were administered in the tests, subjects did not improve their performance across trials. Errors were due to preferences for specific locations or boxes, simple search strategies, and attentional deficits. The performances of at least 2 subjects that achieved very high scores up to the successive invisible displacement task suggest that this species is able to represent the existence and the movements of unperceived objects. ((c) 2004 APA, all rights reserved)

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

Raminosoa, Tsarafidy; Alexander, James Pellegrino; EL-Refaie, Ayman Mohamed Fawzi

A permanent magnet electrical machine includes a stator having conductive windings wound thereon and one or more permanent magnets embedded in the stator. A magnetic keeper element is positioned on the stator so as to form a magnetic flux path with the permanent magnets, with the magnetic keeper element closing the magnetic flux path of the permanent magnets by providing a low reluctance flux path to magnetic flux generated by the permanent magnets. A vacuum pressure impregnation (VPI) process is performed on the stator to increase a thermal conductivity of the windings, with the VPI process including a curing stepmore » that is performed at a selected temperature. The magnetic keeper element sets an operating point of the permanent magnets to an internal flux density level above a demagnetization threshold associated with the selected temperature at which the curing step is performed.« less

Characteristics Buton Natural Asphalt-Rubber (BNA-R) on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

NASA Astrophysics Data System (ADS)

Wahjuningsih, Nurul; Pranowo Hadiwardoyo, Sigit; Jachrizal Sumabrata, R.

2018-03-01

The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

Acute and Chronic Altitude-Induced Cognitive Dysfunction in Children and Adolescents.

PubMed

Rimoldi, Stefano F; Rexhaj, Emrush; Duplain, Hervé; Urben, Sébastien; Billieux, Joël; Allemann, Yves; Romero, Catherine; Ayaviri, Alejandro; Salinas, Carlos; Villena, Mercedes; Scherrer, Urs; Sartori, Claudio

2016-02-01

To assess whether exposure to high altitude induces cognitive dysfunction in young healthy European children and adolescents during acute, short-term exposure to an altitude of 3450 m and in an age-matched European population permanently living at this altitude. We tested executive function (inhibition, shifting, and working memory), memory (verbal, short-term visuospatial, and verbal episodic memory), and speed processing ability in: (1) 48 healthy nonacclimatized European children and adolescents, 24 hours after arrival at high altitude and 3 months after return to low altitude; (2) 21 matched European subjects permanently living at high altitude; and (3) a matched control group tested twice at low altitude. Short-term hypoxia significantly impaired all but 2 (visuospatial memory and processing speed) of the neuropsychological abilities that were tested. These impairments were even more severe in the children permanently living at high altitude. Three months after return to low altitude, the neuropsychological performances significantly improved and were comparable with those observed in the control group tested only at low altitude. Acute short-term exposure to an altitude at which major tourist destinations are located induces marked executive and memory deficits in healthy children. These deficits are equally marked or more severe in children permanently living at high altitude and are expected to impair their learning abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

Variable high gradient permanent magnet quadrupole (QUAPEVA)

NASA Astrophysics Data System (ADS)

Marteau, F.; Ghaith, A.; N'Gotta, P.; Benabderrahmane, C.; Valléau, M.; Kitegi, C.; Loulergue, A.; Vétéran, J.; Sebdaoui, M.; André, T.; Le Bec, G.; Chavanne, J.; Vallerand, C.; Oumbarek, D.; Cosson, O.; Forest, F.; Jivkov, P.; Lancelot, J. L.; Couprie, M. E.

2017-12-01

Different applications such as laser plasma acceleration, colliders, and diffraction limited light sources require high gradient quadrupoles, with strength that can reach up to 200 T/m for a typical 10 mm bore diameter. We present here a permanent magnet based quadrupole (so-called QUAPEVA) composed of a Halbach ring and surrounded by four permanent magnet cylinders. Its design including magnetic simulation modeling enabling us to reach 201 T/m with a gradient variability of 45% and mechanical issues are reported. Magnetic measurements of seven systems of different lengths are presented and confirmed the theoretical expectations. The variation of the magnetic center while changing the gradient strength is ±10 μm. A triplet of QUAPEVA magnets is used to efficiently focus a beam with large energy spread and high divergence that is generated by a Laser Plasma Acceleration source for a free electron laser demonstration and has enabled us to perform beam based alignment and control the dispersion of the beam.

Cogging Torque Reduction Techniques for Spoke-type IPMSM

NASA Astrophysics Data System (ADS)

Bahrim, F. S.; Sulaiman, E.; Kumar, R.; Jusoh, L. I.

2017-08-01

A spoke-type interior permanent magnet synchronous motor (IPMSM) is extending its tentacles in industrial arena due to good flux-weakening capability and high power density. In many of the application, high strength of permanent magnet causes the undesirable effects of high cogging torque that can aggravate performance of the motor. High cogging torque is significantly produced by IPMSM due to the similar length and the effectiveness of the magnetic air-gap. The address of this study is to analyze and compare the cogging torque effect and performance of four common techniques for cogging torque reduction such as skewing, notching, pole pairing and rotor pole pairing. With the aid of 3-D finite element analysis (FEA) by JMAG software, a 6S-4P Spoke-type IPMSM with various rotor-PM configurations has been designed. As a result, the cogging torque effect reduced up to 69.5% for skewing technique, followed by 31.96%, 29.6%, and 17.53% by pole pairing, axial pole pairing and notching techniques respectively.

Rotating permanent magnet excitation for blood flow measurement.

PubMed

Nair, Sarath S; Vinodkumar, V; Sreedevi, V; Nagesh, D S

2015-11-01

A compact, portable and improved blood flow measurement system for an extracorporeal circuit having a rotating permanent magnetic excitation scheme is described in this paper. The system consists of a set of permanent magnets rotating near blood or any conductive fluid to create high-intensity alternating magnetic field in it and inducing a sinusoidal varying voltage across the column of fluid. The induced voltage signal is acquired, conditioned and processed to determine its flow rate. Performance analysis shows that a sensitivity of more than 250 mV/lpm can be obtained, which is more than five times higher than conventional flow measurement systems. Choice of rotating permanent magnet instead of an electromagnetic core generates alternate magnetic field of smooth sinusoidal nature which in turn reduces switching and interference noises. These results in reduction in complex electronic circuitry required for processing the signal to a great extent and enable the flow measuring device to be much less costlier, portable and light weight. The signal remains steady even with changes in environmental conditions and has an accuracy of greater than 95%. This paper also describes the construction details of the prototype, the factors affecting sensitivity and detailed performance analysis at various operating conditions.

Vibrational Properties of High- Superconductors Levitated Above a Bipolar Permanent Magnetic Guideway

NASA Astrophysics Data System (ADS)

Liu, Lu; Wang, Jiasu

2014-05-01

A bipolar permanent magnetic guideway (PMG) has a unique magnetic field distribution profile which may introduce a better levitation performance and stability to the high- superconducting (HTS) maglev system. The dynamic vibration properties of multiple YBCO bulks arranged into different arrays positioned above a bipolar PMG and free to levitate were investigated. The acceleration and resonance frequencies were experimentally measured, and the stiffness and damping coefficients were evaluated for dynamic stability. Results indicate that the levitation stiffness is closely related to the field-cooling-height and sample positioning. The damping ratio was found to be low and nonlinear for the Halbach bipolar HTS-PMG system.

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Light Metals Permanent Mold Casting

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

Fasoyinu, Yemi

2014-03-31

Current vehicles use mostly ferrous components for structural applications. It is possible to reduce the weight of the vehicle by substituting these parts with those made from light metals such as aluminum and magnesium. Many alloys and manufacturing processes can be used to produce these light metal components and casting is known to be most economical. One of the high integrity casting processes is permanent mold casting which is the focus of this research report. Many aluminum alloy castings used in automotive applications are produced by the sand casting process. Also, aluminum-silicon (Al-Si) alloys are the most widely used alloymore » systems for automotive applications. It is possible that by using high strength aluminum alloys based on an aluminum-copper (Al-Cu) system and permanent mold casting, the performance of these components can be enhanced significantly. This will also help to further reduce the weight. However, many technological obstacles need to be overcome before using these alloys in automotive applications in an economical way. There is very limited information in the open literature on gravity and low-pressure permanent mold casting of high strength aluminum alloys. This report summarizes the results and issues encountered during the casting trials of high strength aluminum alloy 206.0 (Al-Cu alloy) and moderate strength alloy 535.0 (Al-Mg alloy). Five engineering components were cast by gravity tilt-pour or low pressure permanent mold casting processes at CanmetMATERIALS (CMAT) and two production foundries. The results of the casting trials show that high integrity engineering components can be produced successfully from both alloys if specific processing parameters are used. It was shown that a combination of melt processing and mold temperature is necessary for the elimination of hot tears in both alloys.« less

Permanent magnet design for high-speed superconducting bearings

DOEpatents

Hull, John R.; Uherka, Kenneth L.; Abdoud, Robert G.

1996-01-01

A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

Development of a low-cost double rotor axial flux motor with soft magnetic composite and ferrite permanent magnet materials

NASA Astrophysics Data System (ADS)

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

2015-05-01

This paper proposes a low-cost double rotor axial flux motor (DRAFM) with low cost soft magnetic composite (SMC) core and ferrite permanent magnets (PMs). The topology and operating principle of DRAFM and design considerations for best use of magnetic materials are presented. A 905 W 4800 rpm DRAFM is designed for replacing the high cost NdFeB permanent magnet synchronous motor (PMSM) in a refrigerator compressor. By using the finite element method, the electromagnetic parameters and performance of the DRAFM operated under the field oriented control scheme are calculated. Through the analysis, it is shown that that the SMC and ferrite PM materials can be good candidates for low-cost electric motor applications.

A 2 Tesla Full Scale High Performance Periodic Permanent Magnet Model for Attractive (228 KN) and repulsive Maglev

NASA Technical Reports Server (NTRS)

Stekly, Z. J. J.; Gardner, C.; Domigan, P.; Baker, J.; Hass, M.; McDonald, C.; Wu, C.; Farrell, R. A.

1996-01-01

Two 214.5 cm. long high performance periodic (26 cm period) permanent magnet half-assemblies were designed and constructed for use as a wiggler using Nd-B-Fe and vanadium permendur as hard and soft magnetic materials by Field Effects, a division of Intermagnetics General Corporation. Placing these assemblies in a supporting structure with a 2.1 cm pole to pole separation resulted in a periodic field with a maximum value of 2.04 T. This is believed to be the highest field ever achieved by this type of device. The attractive force between the two 602 kg magnet assemblies is 228 kN, providing enough force for suspension of a 45,500 kg vehicle. If used in an attractive maglev system with an appropriate flat iron rail, one assembly will generate the same force with a gap of 1.05 cm leading to a lift to weight ratio of 38.6, not including the vehicle attachment structure. This permanent magnet compares well with superconducting systems which have lift to weight ratios in the range of 5 to 10. This paper describes the magnet assemblies and their measured magnetic performance. The measured magnetic field and resulting attractive magnetic force have a negative spring characteristic. Appropriate control coils are necessary to provide stable operation. The estimated performance of the assemblies in a stable repulsive mode, with eddy currents in a conducting guideway, is also discussed.

Permanent magnet design for high-speed superconducting bearings

DOEpatents

Hull, J.R.; Uherka, K.L.; Abdoud, R.G.

1996-09-10

A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure is disclosed. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing. 9 figs.

Laboratory evaluation of high asphalt binder replacement with recycled asphalt shingles (RAS) for a low n-design asphalt mixture.

DOT National Transportation Integrated Search

2012-10-01

This study investigated the effect of high asphalt binder replacement for a low N-design asphalt mixture including : RAP and RAS on performance indicators such as permanent deformation, fracture, fatigue potentials, and : stiffness, was studied. An e...

A Double-Sided Linear Primary Permanent Magnet Vernier Machine

PubMed Central

2015-01-01

The purpose of this paper is to present a new double-sided linear primary permanent magnet (PM) vernier (DSLPPMV) machine, which can offer high thrust force, low detent force, and improved power factor. Both PMs and windings of the proposed machine are on the short translator, while the long stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. The key of this new machine is the introduction of double stator and the elimination of translator yoke, so that the inductance and the volume of the machine can be reduced. Hence, the proposed machine offers improved power factor and thrust force density. The electromagnetic performances of the proposed machine are analyzed including flux, no-load EMF, thrust force density, and inductance. Based on using the finite element analysis, the characteristics and performances of the proposed machine are assessed. PMID:25874250

A double-sided linear primary permanent magnet vernier machine.

PubMed

Du, Yi; Zou, Chunhua; Liu, Xianxing

2015-01-01

The purpose of this paper is to present a new double-sided linear primary permanent magnet (PM) vernier (DSLPPMV) machine, which can offer high thrust force, low detent force, and improved power factor. Both PMs and windings of the proposed machine are on the short translator, while the long stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. The key of this new machine is the introduction of double stator and the elimination of translator yoke, so that the inductance and the volume of the machine can be reduced. Hence, the proposed machine offers improved power factor and thrust force density. The electromagnetic performances of the proposed machine are analyzed including flux, no-load EMF, thrust force density, and inductance. Based on using the finite element analysis, the characteristics and performances of the proposed machine are assessed.

Analytical analysis and implementation of a low-speed high-torque permanent magnet vernier in-wheel motor for electric vehicle

NASA Astrophysics Data System (ADS)

Li, Jiangui; Wang, Junhua; Zhigang, Zhao; Yan, Weili

2012-04-01

In this paper, analytical analysis of the permanent magnet vernier (PMV) is presented. The key is to analytically solve the governing Laplacian/quasi-Poissonian field equations in the motor regions. By using the time-stepping finite element method, the analytical method is verified. Hence, the performances of the PMV machine are quantitatively compared with that of the analytical results. The analytical results agree well with the finite element method results. Finally, the experimental results are given to further show the validity of the analysis.

30 CFR 817.122 - Subsidence control: Public notice.

Code of Federal Regulations, 2010 CFR

2010-07-01

... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING... to all owners and occupants of surface property and structures above the underground workings. The...

High-Performance Permanent Magnets for Energy-Efficient Devices

NASA Astrophysics Data System (ADS)

Hadjipanayis, George

2012-02-01

Permanent magnets (PMs) are indispensable for many commercial applications including the electric, electronic and automobile industries, communications, information technologies and automatic control engineering. In most of these applications, an increase in the magnetic energy density of the PM, usually presented via the maximum energy product (BH)max, immediately increases the efficiency of the whole device and makes it smaller and lighter. Worldwide demand for high performance permanent magnets has increased dramatically in the past few years driven by hybrid and electric cars, wind turbines and other power generation systems. New energy challenges in the world require devices with higher energy efficiency and minimum environmental impact. The potential of 3d-4f compounds which revolutionized the PM science and technology is almost fully utilized, and the supply of 4f rare earth elements does not seem to be much longer assured. This talk will address the major principles guiding the development of PMs and overview state-of-the-art theoretical and experimental research. Recent progress in the development of nanocomposite PMs, consisting of a fine (at the scale of the magnetic exchange length) mixture of phases with high magnetization and large magnetic hardness will be discussed. Fabrication of such PMs is currently the most promising way to boost the (BH)max, while simultaneously decreasing, at least partially, the reliance on the rare earth elements. Special attention will be paid to the impact which the next-generation high-(BH)max magnets is expected to have on existing and proposed energy-saving technologies.

Individual differences in infant fearfulness and cognitive performance: a testing, performance, or competence effect?

PubMed

Rieser-Danner, Loretta A

2003-02-01

The author conducted 2 studies to examine the relations between infant fear and cognitive testing performance in 12-month-old infants. In Study 1, fear was assessed by using 2 standard temperament questionnaires and a laboratory-based, standardized stranger approach. Individual differences in cognitive development were assessed using the Object Permanence Scale of the Infant Psychological Development Scales (I. C. Uzgiris & J. M. Hunt, 1975). All 3 assessments of fear significantly predicted object permanence performance, with correlations ranging from -.32 to -.35. In Study 2, fear was assessed via a maternal report questionnaire, and habituation performance was assessed via a basic-level categorization task. Familiarity with the examiner and with the testing environment was manipulated to test for a familiarity influence on performance. Testing revealed individual differences in both fear and habituation. Results suggest that highly fearful infants required more trials to habituate and were less likely to meet the habituation criterion than infants who were less fearful. Methodological and conceptual implications of these results are discussed.

Dental caries in Arab League countries: a systematic review and meta-analysis.

PubMed

Khan, Soban Qadir

2014-08-01

The aim of this review was to determine prevalence of dental caries in primary and permanent teeth in the 2-20-year-old population of the Arab league. A literature search was performed on Pubmed, Summon and Google Scholar using the key words 'Dental caries', 'dmft' and 'DMFT'. A total of 293 articles were found, of which 35 passed our inclusion criteria and were included in analysis. Tables were made separately for primary and permanent teeth; the age group for primary teeth was 2-12 years and for permanent teeth 6-20 years. A meta-analysis was run by using data extracted from the studies included. Heterogeneity was tested by forest plot and chi-square test, and considerable heterogeneity was found. Mean decayed, missing and filled teeth (dmft) was 4.341 (95% CI 3.714, 4.969) and in permanent teeth (DMFT) was 2.469 (95% CI 2.019, 2.919) from a random effect model. Publication bias diagnostics suggested missing of four studies of primary teeth caries data and eight studies of permanent teeth caries data to obtain symmetry in the funnel plot. The incidence of caries in primary teeth was found to be high compared with caries in permanent teeth in the Arab League. This study does not provide a comprehensive picture of caries prevalence in the Arab League because in many of these countries only a few studies were performed. Therefore, these data cannot provide a complete picture of the prevalence of caries in those countries. Additional studies are needed to better evaluate the prevalence of caries in children and young adults in Arab League countries. © 2014 FDI World Dental Federation.

Children of psychotic mothers. An evaluation of 1-year-olds on a test of object permanence.

PubMed

Gamer, E; Gallant, D; Grunebaum, H

1976-03-01

Fifteen 1-year-old infants at high risk for later psychopathologic behavior were tested on the Piaget Object Scale. Their performance was compared to that of a matched group of controls at low risk. Results indicate a trend in the high-risk group toward lowered object scale performance. Affective styles were found to vary between the groups. The high-risk infants, particularly those with low scores on the object scale, demonstrated more intense anxiety.

High performance hybrid magnetic structure for biotechnology applications

DOEpatents

Humphries, David E [El Cerrito, CA; Pollard, Martin J [El Cerrito, CA; Elkin, Christopher J [San Ramon, CA

2009-02-03

The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are further improvements to aspects of the hybrid magnetic structure, including additional elements and for adapting the use of the hybrid magnetic structure for use in biotechnology and high throughput processes.

Evaluation of secondary alveolar bone grafting outcomes performed after canine eruption in complete unilateral cleft lip and palate.

PubMed

Lorenzoni, Diego Coelho; Janson, Guilherme; Bastos, Juliana Cunha; Carvalho, Roberta Martinelli; Bastos, José Carlos; de Cássia Moura Carvalho Lauris, Rita; Henriques, José Fernando Castanha; Ozawa, Terumi Okada

2017-01-01

Evaluate the results of secondary alveolar bone grafting (SABG) in patients with complete unilateral cleft lip and palate (UCLP), operated after permanent canine eruption (CE). Seventy-four periapical radiographs from patients with complete UCLP (mean age 14 years) submitted to SABG were retrospectively analyzed for the amount of bone in the cleft site through the Bergland and Chelsea scales. Of the cases, 47.3 % was classified as Bergland type I and Chelsea type A, 35.2 % as type II/C, 6.7 % as type III/D, and 10.8 % as type IV/failure. When the canine was moved into the grafted area, the success rate (type I/A) was 56.8 %; for cases in which the space was maintained for an implant or prosthetic finishing, the index was 45.8 %; however, this difference was not statistically significant. Even in advanced ages, after permanent canine eruption, SABG can be considered a highly successful procedure. This research shows good results of secondary alveolar bone grafting performed in patients with unilateral complete cleft lip and palate, even when it was performed after eruption of the permanent canine in the cleft area.

30 CFR 819.21 - Auger mining: Protection of underground mining.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE... closer than 500 feet (measured horizontally) to any abandoned or active underground mine workings, except...

Highly stable and finely tuned magnetic fields generated by permanent magnet assemblies.

PubMed

Danieli, E; Perlo, J; Blümich, B; Casanova, F

2013-05-03

Permanent magnetic materials are the only magnetic source that can be used to generate magnetic fields without power consumption or maintenance. Such stand-alone magnets are very attractive for many scientific and engineering areas, but they suffer from poor temporal field stability, which arises from the strong sensitivity of the magnetic materials and mechanical support to temperature variation. In this work, we describe a highly efficient method useful to cancel the temperature coefficient of permanent magnet assemblies in a passive and accurate way. It is based on the combination of at least two units made of magnetic materials with different temperature coefficients arranged in such a way that the ratio of the fields generated by each unit matches the ratio of their effective temperature coefficients defined by both the magnetic and mechanical contributions. Although typically available magnetic materials have negative temperature coefficients, the cancellation is achieved by aligning the fields generated by each unit in the opposite direction. We demonstrate the performance of this approach by stabilizing the field generated by a dipolar Halbach magnet, recently proposed to achieve high field homogeneity. Both the field drift and the homogeneity are monitored via nuclear magnetic resonance spectroscopy experiments. The results demonstrate the compatibility of the thermal compensation approach with existing strategies useful to fine-tune the spatial dependence of the field generated by permanent magnet arrays.

Perspectives on Permanent Magnetic Materials for Energy Conversion and Power Generation

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

Lewis, LH; Jimenez-Villacorta, F

2012-07-18

Permanent magnet development has historically been driven by the need to supply larger magnetic energy in ever smaller volumes for incorporation in an enormous variety of applications that include consumer products, transportation components, military hardware, and clean energy technologies such as wind turbine generators and hybrid vehicle regenerative motors. Since the 1960s, the so-called rare-earth "supermagnets," composed of iron, cobalt, and rare-earth elements such as Nd, Pr, and Sm, have accounted for the majority of global sales of high-energy-product permanent magnets for advanced applications. In rare-earth magnets, the transition-metal components provide high magnetization, and the rare-earth components contribute a verymore » large magnetocrystalline anisotropy that donates high resistance to demagnetization. However, at the end of 2009, geopolitical influences created a worldwide strategic shortage of rare-earth elements that may be addressed, among other actions, through the development of rare-earth-free magnetic materials harnessing sources of magnetic anisotropy other than that provided by the rare-earth components. Materials engineering at the micron scale, nanoscale, and Angstrom scales, accompanied by improvements in the understanding and characterization of nanoscale magnetic phenomena, is anticipated to result in new types of permanent magnetic materials with superior performance. DOI: 10.1007/s11661-012-1278-2 (C) The Minerals, Metals & Materials Society and ASM International 2012« less

Development of enhanced piezoelectric energy harvester induced by human motion.

PubMed

Minami, Y; Nakamachi, E

2012-01-01

In this study, a high frequency piezoelectric energy harvester converted from the human low vibrated motion energy was newly developed. This hybrid energy harvester consists of the unimorph piezoelectric cantilever and a couple of permanent magnets. One magnet was attached at the end of cantilever, and the counterpart magnet was set at the end of the pendulum. The mechanical energy provided through the human walking motion, which is a typical ubiquitous presence of vibration, is converted to the electric energy via the piezoelectric cantilever vibration system. At first, we studied the energy convert mechanism and the performance of our energy harvester, where the resonance free vibration of unimorph cantilever with one permanent magnet under a rather high frequency was induced by the artificial low frequency vibration. The counterpart magnet attached on the pendulum. Next, we equipped the counterpart permanent magnet pendulum, which was fluctuated under a very low frequency by the human walking, and the piezoelectric cantilever, which had the permanent magnet at the end. The low-to-high frequency convert "hybrid system" can be characterized as an enhanced energy harvest one. We examined and obtained maximum values of voltage and power in this system, as 1.2V and 1.2 µW. Those results show the possibility to apply for the energy harvester in the portable and implantable Bio-MEMS devices.

Preliminary Results of Performance Measurements on a Cylindrical Hall-Effect Thruster with Magnetic Field Generated by Permanent Magnets

NASA Technical Reports Server (NTRS)

Polzin, K. A.; Raitses, Y.; Merino, E.; Fisch, N. J.

2008-01-01

The performance of a low-power cylindrical Hall thruster, which more readily lends itself to miniaturization and low-power operation than a conventional (annular) Hall thruster, was measured using a planar plasma probe and a thrust stand. The field in the cylindrical thruster was produced using permanent magnets, promising a power reduction over previous cylindrical thruster iterations that employed electromagnets to generate the required magnetic field topology. Two sets of ring-shaped permanent magnets are used, and two different field configurations can be produced by reorienting the poles of one magnet relative to the other. A plasma probe measuring ion flux in the plume is used to estimate the current utilization for the two magnetic configurations. The measurements indicate that electron transport is impeded much more effectively in one configuration, implying a higher thrust efficiency. Preliminary thruster performance measurements on this configuration were obtained over a power range of 100-250 W. The thrust levels over this power range were 3.5-6.5 mN, with anode efficiencies and specific impulses spanning 14-19% and 875- 1425 s, respectively. The magnetic field in the thruster was lower for the thrust measurements than the plasma probe measurements due to heating and weakening of the permanent magnets, reducing the maximum field strength from 2 kG to roughly 750-800 G. The discharge current levels observed during thrust stand testing were anomalously high compared to those levels measured in previous experiments with this thruster.

10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Performance objectives for the geologic repository after...-LEVEL RADIOACTIVE WASTES IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Technical Criteria Postclosure Performance Objectives § 63.113 Performance objectives for the geologic repository after permanent...

30 CFR 816.14 - Casing and sealing of drilled holes: Temporary.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS... approved permit application for use to return coal processing waste or water to underground workings, or to...

30 CFR 817.14 - Casing and sealing of underground openings: Temporary.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS... workings, or to be used to monitor ground water conditions, shall be temporarily sealed until actual use. ...

Chemically Inhomogeneous RE-Fe-B Permanent Magnets with High Figure of Merit: Solution to Global Rare Earth Criticality

PubMed Central

Jin, Jiaying; Ma, Tianyu; Zhang, Yujing; Bai, Guohua; Yan, Mi

2016-01-01

The global rare earth (RE) criticality, especially for those closely-relied Nd/Pr/Dy/Tb in the 2:14:1-typed permanent magnets (PMs), has triggered tremendous attempts to develop new alternatives. Prospective candidates La/Ce with high abundance, however, cannot provide an equivalent performance due to inferior magnetic properties of (La/Ce)2Fe14B to Nd2Fe14B. Here we report high figure-of-merit La/Ce-rich RE-Fe-B PMs, where La/Ce are inhomogeneously distributed among the 2:14:1 phase. The resultant exchange coupling within an individual grain and magnetostatic interactions across grains ensure much superior performance to the La/Ce homogeneously distributed magnet. Maximum energy product (BH)max of 42.2 MGOe is achieved even with 36 wt. % La-Ce incorporation. The cost performance, (BH)max/cost, has been raised by 27.1% compared to a 48.9 MGOe La/Ce-free commercial magnet. The construction of chemical heterogeneity offers recipes to develop commercial-grade PMs using the less risky La/Ce, and also provides a promising solution to the REs availability constraints. PMID:27553789

Design improvement of permanent magnet flux switching motor with dual rotor structure

NASA Astrophysics Data System (ADS)

Soomro, H. A.; Sulaiman, E.; Kumar, R.; Rahim, N. S.

2017-08-01

This paper presents design enhancement to reduce permanent magnet (PM) volume for 7S-6P-7S dual rotor permanent magnet flux-switching machines (DRPMFSM) for electric vehicle application. In recent years, Permanent magnet flux switching (PMFS) motor and a new member of brushless permanent magnet machine are prominently used for the electric vehicle. Though, more volume of Rare-Earth Permanent Magnet (REPM) is used to increase the cost and weight of these motors. Thus, to overcome the issue, new configuration of 7S-6P- 7S dual rotor permanent magnet flux-switching machine (DRPMFSM) has been proposed and investigated in this paper. Initially proposed 7S-6P-7S DRPMFSM has been optimized using “deterministic optimization” to reduce the volume of PM and to attain optimum performances. In addition, the performances of initial and optimized DRPMFSM have been compared such that back-emf, cogging torque, average torque, torque and power vs speed performances, losses and efficiency have been analysed by 2D-finite element analysis (FEA) using the JMAG- Designer software ver. 14.1. Consequently, the final design 7S-6P-7S DRPMFSM has achieved the efficiency of 83.91% at reduced PM volume than initial design to confirm the better efficient motor for HEVs applications.

Long-term survival and vitality outcomes of permanent teeth following deep caries treatment with step-wise and partial-caries-removal: A Systematic Review.

PubMed

Hoefler, Vaughan; Nagaoka, Hiroko; Miller, Craig S

2016-11-01

A systematic review was performed to compare the long-term survival of deep dentine caries-affected permanent teeth treated with partial-caries-removal (PCR) versus similar teeth treated with stepwise-caries-removal techniques (SWT). Clinical studies investigating long-term PCR and SWT outcomes in unrestored permanent teeth with deep dentine caries were evaluated. Failures were defined as loss of pulp vitality or restorative failures following treatment. PubMed, Web of Science, Dentistry and Oral Sciences Source, and Central databases were systematically searched. From 136 potentially relevant articles, 9 publications utilizing data from 5 studies (2 RCTs, and 3 observational case-series) reporting outcomes for 426 permanent teeth over two to ten years were analyzed. Regarding restorative failures, >88% success at two years for both techniques was reported. For loss of pulp vitality, observational studies reported >96% vitality at two years for each technique, while one RCT reported significantly higher vitality (p<0.05) at three years for PCR (96%) compared to SWT (83%). Risk of bias was high in all studies. Successful vitality and restorative outcomes for both PCR and SWT have been demonstrated at two years and beyond in permanent teeth with deep dentine caries. Partial-caries-removal may result in fewer pulpal complications over a three year period than SWT, although claims of a therapeutic advantage are based on very few, limited-quality studies. Partial-caries-removal and SWT are deep caries management techniques that reduce pulp exposure risk. Permanent teeth with deep dentine caries treated with either technique have a high likelihood for survival beyond two years. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design and analysis of a novel doubly salient permanent- magnet generator

NASA Astrophysics Data System (ADS)

Sarlioglu, Bulent

Improvements in permanent magnets and power electronics technologies have made it possible to devise different configurations of electrical machines which were not previously possible to implement. In this dissertation, a novel Doubly Salient Permanent Magnet (DSPM) generator has been designed, analyzed, and tested. The DSPM generator has four stator poles and six rotor poles. Two high density permanent magnets are located in the stator yoke. Since there are no windings or permanent magnets in the rotor, the DSPM generator has several advantages: the rotor has low inertia, no copper loss, no PM attachments, no brushes, and no slip rings. This type of rotor can be manufactured easily, and can be run at very high speeds as in the case of a switched reluctance machine. Compared to induction and switched reluctance machines, the DSPM generator can produce more power from the same geometry. Moreover, the efficiency of the DSPM generator is higher, since there is no copper loss associated with excitation of the machine. Another advantage of the DSPM generator is that the output AC voltage can easily be rectified by a diode bridge rectifier, while in the case of the switched reluctance machine one needs to use active semiconductor switches for power generation. If greater utilization and control of power production capability are desired, the AC output of the DSPM generator can be rectified using an active converter. In this dissertation, a novel doubly salient permanent magnet generator is introduced. First, the theory of the DSPM generator is given. Later, this novel generator is investigated using conventional magnetic circuits, nonlinear finite element analysis, and simulations with first order approximations and nonlinear modeling. It is compared with other generators. Static and no-load testing of the prototype DSPM generator are presented, and generator performance is evaluated with various power electronic circuits.

Estimated prevalence of erosive tooth wear in permanent teeth of children and adolescents: an epidemiological systematic review and meta-regression analysis.

PubMed

Salas, M M S; Nascimento, G G; Huysmans, M C; Demarco, F F

2015-01-01

The main purpose of this systematic review was to estimate the prevalence of dental erosion in permanent teeth of children and adolescents. An electronic search was performed up to and including March 2014. Eligibility criteria included population-based studies in permanent teeth of children and adolescents aged 8-19-year-old reporting the prevalence or data that allowed the calculation of prevalence rates of tooth erosion. Data collection assessed information regarding geographic location, type of index used for clinical examination, sample size, year of publication, age, examined teeth and tissue exposure. The estimated prevalence of erosive wear was determined, followed by a meta-regression analysis. Twenty-two papers were included in the systematic review. The overall estimated prevalence of tooth erosion was 30.4% (95%IC 23.8-37.0). In the multivariate meta-regression model use of the Tooth Wear Index for clinical examination, studies with sample smaller than 1000 subjects and those conducted in the Middle East and Africa remained associated with higher dental erosion prevalence rates. Our results demonstrated that the estimated prevalence of erosive wear in permanent teeth of children and adolescents is 30.4% with high heterogeneity between studies. Additionally, the correct choice of a clinical index for dental erosion detection and the geographic location play an important role for the large variability of erosive tooth wear in permanent teeth of children and adolescents. The prevalence of tooth erosion observed in permanent teeth of children and adolescents was considerable high. Our results demonstrated that prevalence rate of erosive wear was influenced by methodological and diagnosis factors. When tooth erosion is assessed, the clinical index should be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

Magnetic bearings for inertial energy storage

NASA Technical Reports Server (NTRS)

Rodriguez, G. Ernest; Eakin, Vickie

1987-01-01

Advanced flywheels utilizing high strength fibers must operate at high rotational speeds and as such must operate in vacuum to reduce windage losses. The utilization of magnetic bearings in the flywheels overcome lubrication and seal problems, resulting in an energy storage system offering potential improvements over conventional electrochemical energy storage. Magnetic bearings evolved in the 1950s from the simple application of permanent magnets positioned to exert repulsive forces to the present where permanent magnets and electromagnets have been combined to provide axial and radial suspension. Further development of magnetic suspension has led to the design of a shaftless flywheel system for aerospace application. Despite the lack of proof of concept, integrated magnetic suspension in inertial storage systems can provide significant performance improvements to warrant development and tests.

Superconductor Permanent Magnets for Advanced Propulsion Applications

NASA Astrophysics Data System (ADS)

Putman, Phil; Zhou, Yuxiang; Salama, Kamel; Robertson, Tony; Bond, Deborah D.

2005-02-01

Improved trapped fields of 17 T at 29 K and 11.2 T at 47 K have been reported for the melt-textured YBCO superconductor material. Such high field strengths give the possibility for producing superconductor permanent magnets (SCPM) for plasma-related space propulsion applications, such as the anti-matter trap, magnetohydrodynamic (MHD) propulsion and electrical power generation, and others that are under development or being studied. The SCPM could be beneficial in reducing the weight-to-power ratio for the associated delivery and containment systems needed for plasma interactions that are inherently imbedded in many of these propulsion systems. In this paper, a review of the superconductor literature is presented, followed by uses of the SCPM in high-performance space propulsion applications.

Cluster-Expansion Model for Complex Quinary Alloys: Application to Alnico Permanent Magnets

NASA Astrophysics Data System (ADS)

Nguyen, Manh Cuong; Zhou, Lin; Tang, Wei; Kramer, Matthew J.; Anderson, Iver E.; Wang, Cai-Zhuang; Ho, Kai-Ming

2017-11-01

An accurate and transferable cluster-expansion model for complex quinary alloys is developed. Lattice Monte Carlo simulation enabled by this cluster-expansion model is used to investigate temperature-dependent atomic structure of alnico alloys, which are considered as promising high-performance non-rare-earth permanent-magnet materials for high-temperature applications. The results of the Monte Carlo simulations are consistent with available experimental data and provide useful insights into phase decomposition, selection, and chemical ordering in alnico. The simulations also reveal a previously unrecognized D 03 alloy phase. This phase is very rich in Ni and exhibits very weak magnetization. Manipulating the size and location of this phase provides a possible route to improve the magnetic properties of alnico, especially coercivity.

Decoupling analysis of a novel bearingless flux-switching permanent magnet motor

NASA Astrophysics Data System (ADS)

Zhao, Chenyin; Zhu, Huangqiu; Qin, Yuemei

2017-05-01

In this paper, a novel 12/10 stator/rotor pole bearingless flux-switching permanent magnet (BFSPM) motor is proposed to overcome the drawbacks of rotor permanent magnet type bearingless motors. The basic motor configuration, including motor configuration and winding configuration, is introduced firstly. Then, based on the principle of reverse direction magnetization for symmetrical rotor teeth, the radial suspension forces generation principle is analyzed in detail. Finally, decoupling performances between suspension force windings and torque windings are investigated. The results show that the proposed BFSPM not only ensures the merits of high torque output capability compared with conventional 12/10 stator/rotor pole FSPM motor, but also achieves stable radial suspension forces which have little mutual effect with torque. The validity of the proposed structure has been verified by finite element analysis (FEA).

Low permanent pacemaker rates following Lotus device implantation for transcatheter aortic valve replacement due to modified implantation protocol.

PubMed

Krackhardt, Florian; Kherad, Behrouz; Krisper, Maximilian; Pieske, Burkert; Laule, Michael; Tschöpe, Carsten

2017-01-01

Conduction disturbances requiring permanent pacemaker implantation following transcatheter aortic valve replacement (TAVR) are a common problem. Pacemaker implantation rates after TAVR appear to be higher compared to conventional aortic valve replacement. The aim of this study was to analyze whether a high annulus implantation conveys the benefit of a decreased rate of permanent pacemaker implantation while being safe and successful according to Valve Academic Research Consortium 2 (VARC2)-criteria. A total of 23 patients with symptomatic severe aortic valve stenosis, an aortic annulus of 19-27 mm and at high risk for surgery were treated with the Lotus valve. In all patients the valve was implanted in a high annulus position via femoral access. The primary device performance endpoint was VARC2-defined device success after 30 days and the primary safety endpoint was the need for permanent pacemaker implantation. The mean age was 73.23 ± 7.65 years, 46% were female, 38% were New York Heart Association class III/IV at baseline. Thirty-day follow-up data were available for all patients. The VARC2-defined device success rate after 30 days was 22/23 (96%). 2/21 (10%) patients required a newly implanted pacemaker due to 3rd degree atrioventricular block. 25% of the patients developed a new left bundle branch block after valvuloplasty or device implantation. 21 of the 23 patients (96%) had no other signs of conduction disturbances after 30 days. The approach of the modified implantation technique of Lotus TAVR device was safe and effective. The incidence of need for a permanent pacemaker following TAVR could be significantly reduced due to adopted implantation protocol.

Measurement of Levitation Forces of High-"T[subscript c] Superconductors

ERIC Educational Resources Information Center

Becker, M.; Koblischka, M. R.; Hartmann, U.

2010-01-01

We show the construction of a so-called levitation balance which is capable of measuring the levitation forces between a permanent magnet and a superconducting high-T[subscript c] thin film sample. The underlying theoretical basis is discussed in detail. The experiment is performed as an introductory physics experiment for school students as well…

Design and experimental validation for direct-drive fault-tolerant permanent-magnet vernier machines.

PubMed

Liu, Guohai; Yang, Junqin; Chen, Ming; Chen, Qian

2014-01-01

A fault-tolerant permanent-magnet vernier (FT-PMV) machine is designed for direct-drive applications, incorporating the merits of high torque density and high reliability. Based on the so-called magnetic gearing effect, PMV machines have the ability of high torque density by introducing the flux-modulation poles (FMPs). This paper investigates the fault-tolerant characteristic of PMV machines and provides a design method, which is able to not only meet the fault-tolerant requirements but also keep the ability of high torque density. The operation principle of the proposed machine has been analyzed. The design process and optimization are presented specifically, such as the combination of slots and poles, the winding distribution, and the dimensions of PMs and teeth. By using the time-stepping finite element method (TS-FEM), the machine performances are evaluated. Finally, the FT-PMV machine is manufactured, and the experimental results are presented to validate the theoretical analysis.

30 CFR 817.180 - Utility installations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.180 Utility installations. All underground mining activities shall be conducted in a manner...; oil, gas, and coal-slurry pipelines, railroads; electric and telephone lines; and water and sewage...

Design Enhancement and Performance Examination of External Rotor Switched Flux Permanent Magnet Machine for Downhole Application

NASA Astrophysics Data System (ADS)

Kumar, R.; Sulaiman, E.; Soomro, H. A.; Jusoh, L. I.; Bahrim, F. S.; Omar, M. F.

2017-08-01

The recent change in innovation and employments of high-temperature magnets, permanent magnet flux switching machine (PMFSM) has turned out to be one of the suitable contenders for seaward boring, however, less intended for downhole because of high atmospheric temperature. Subsequently, this extensive review manages the design enhancement and performance examination of external rotor PMFSM for the downhole application. Preparatory, the essential design parameters required for machine configuration are computed numerically. At that point, the design enhancement strategy is actualized through deterministic technique. At last, preliminary and refined execution of the machine is contrasted and as a consequence, the yield torque is raised from 16.39Nm to 33.57Nm while depreciating the cogging torque and PM weight up to 1.77Nm and 0.79kg, individually. In this manner, it is inferred that purposed enhanced design of 12slot-22pole with external rotor is convenient for the downhole application.

A water-responsive shape memory ionomer with permanent shape reconfiguration ability

NASA Astrophysics Data System (ADS)

Bai, Yongkang; Zhang, Jiwen; Tian, Ran; Chen, Xin

2018-04-01

In this work, a water-responsive shape memory ionomer with high toughness was fabricated by cross-linking hyaluronic acid sodium (HAS) and polyvinyl alcohol (PVA) through coordination interactions. The strong Fe3+-carboxyl (from HAS) coordination interactions served as main physical cross-linking points for the performance of water-responsive shape memory, which associated with the flexibility of PVA chain producing excellent mechanical properties of this ionomer. The optimized ionomer was not only able to recover to its original shape within just 22 s by exposing to water, but exhibited high tensile strength up to 35.4 MPa and 4 times higher tractility than the ionomer without PVA. Moreover, the ionomers can be repeatedly programed to various new permanent shapes on demand due to the reversible physical interactions, which still performed complete and fast geometric recovery under stimuli even after 4 cycles of reprograming with 3 different shapes. The excellent shape memory and strong mechanical behaviors make our ionomers significant and promising smart materials for variety of applications.

Effect of central compartment neck dissection on hypocalcaemia incidence after total thyroidectomy for carcinoma.

PubMed

Mitra, I; Nichani, J R; Yap, B; Homer, J J

2011-05-01

Central compartment neck dissection is increasingly performed as part of surgical management of differentiated thyroid carcinoma. However, elective central neck dissection remains controversial due to complications and lack of evidence of survival benefit. To investigate and compare rates of transient and permanent hypocalcaemia following total thyroidectomy alone, compared with total thyroidectomy with central neck dissection, for differentiated thyroid carcinoma. Retrospective study of 127 consecutive patients referred with differentiated thyroid carcinoma, 2004-2006; 78 patients had undergone total thyroidectomy (group one) and 49 total thyroidectomy with central compartment node dissection (group two). Surgery was performed in various hospitals by both otolaryngologists and endocrine surgeons. In groups one and two, the incidence of transient hypocalcaemia was 18 per cent (14/78) and 51 per cent (25/49) (p < 0.001), and the incidence of permanent hypocalcaemia 1 per cent (one of 77) and 12 per cent (six of 49) (p < 0.01), respectively. Most patients undergoing central neck dissection had evidence of pathological level six lymphadenopathy (29/49). Total thyroidectomy combined with central neck dissection for the treatment of differentiated thyroid carcinoma is more likely to result in transient (51 per cent) and permanent (12 per cent) hypocalcaemia. Elective neck dissection should be performed selectively, with a high expectation of post-operative hypocalcaemia.

Cryogenic Permanent Magnet Undulators

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

Chavanne, J.; Lebec, G.; Penel, C.

For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm{sub 2}Co{sub 17} or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulatormore » above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.« less

A Permanent-Magnet Microwave Ion Source For A Compact High-Yield Neutron Generator

NASA Astrophysics Data System (ADS)

Waldmann, O.; Ludewigt, B.

2011-06-01

We present recent work on the development of a microwave ion source that will be used in a high-yield compact neutron generator for active interrogation applications. The sealed tube generator will be capable of producing high neutron yields, 5×1011 n/s for D-T and ˜1×1010 n/s for D-D reactions, while remaining transportable. We constructed a microwave ion source (2.45 GHz) with permanent magnets to provide the magnetic field strength of 87.5 mT necessary for satisfying the electron cyclotron resonance (ECR) condition. Microwave ion sources can produce high extracted beam currents at the low gas pressures required for sealed tube operation and at lower power levels than previously used RF-driven ion sources. A 100 mA deuterium/tritium beam will be extracted through a large slit (60×6 mm2) to spread the beam power over a larger target area. This paper describes the design of the permanent-magnet microwave ion source and discusses the impact of the magnetic field design on the source performance. The required equivalent proton beam current density of 40 mA/cm2 was extracted at a moderate microwave power of 400 W with an optimized magnetic field.

Analysis and design of asymmetrical reluctance machine

NASA Astrophysics Data System (ADS)

Harianto, Cahya A.

Over the past few decades the induction machine has been chosen for many applications due to its structural simplicity and low manufacturing cost. However, modest torque density and control challenges have motivated researchers to find alternative machines. The permanent magnet synchronous machine has been viewed as one of the alternatives because it features higher torque density for a given loss than the induction machine. However, the assembly and permanent magnet material cost, along with safety under fault conditions, have been concerns for this class of machine. An alternative machine type, namely the asymmetrical reluctance machine, is proposed in this work. Since the proposed machine is of the reluctance machine type, it possesses desirable feature, such as near absence of rotor losses, low assembly cost, low no-load rotational losses, modest torque ripple, and rather benign fault conditions. Through theoretical analysis performed herein, it is shown that this machine has a higher torque density for a given loss than typical reluctance machines, although not as high as the permanent magnet machines. Thus, the asymmetrical reluctance machine is a viable and advantageous machine alternative where the use of permanent magnet machines are undesirable.

Magnetic properties of bulk, and rapidly solidified nanostructured (Nd 1-xCe x) 2Fe 14-yCo yB ribbons

DOE PAGES

Pathak, Arjun K.; Khan, M.; Gschneidner, Jr., K. A.; ...

2015-11-06

Magnetic properties of Ce and Co co-doped (Nd 1-xCe x) 2Fe 14-yCo yB compounds have been investigated both in bulk polycrystalline and rapidly solidified nanostructured ribbon forms. For certain Ce concentrations the materials exhibit spin re-orientation transitions below 140 K. The Curie temperatures, saturation magnetizations, and other magnetic properties relevant for applications as permanent magnets are controlled by Ce and Co substitutions for Nd and Fe, respectively. Most importantly, the results show that Ce, Co co-doped compounds are excellent replacements for several Dy-based high performance permanent magnets (dysprosium is one of the critical elements and is, therefore, in short supply).more » As a result, the high temperature (>375 K) magnetic properties for Nd–Ce–Fe–Co–B based alloys show promise not only as a replacement for Dy-doped Nd 2Fe 14B permanent magnets, but the new alloys also require significantly lower amounts of Nd, which too is the critical element that can be replaced by a more abundant Ce.« less

Frequency-Dependent Selection: The High Potential for Permanent Genetic Variation in the Diallelic, Pairwise Interaction Model

PubMed Central

Asmussen, M. A.; Basnayake, E.

1990-01-01

A detailed analytic and numerical study is made of the potential for permanent genetic variation in frequency-dependent models based on pairwise interactions among genotypes at a single diallelic locus. The full equilibrium structure and qualitative gene-frequency dynamics are derived analytically for a symmetric model, in which pairwise fitnesses are chiefly determined by the genetic similarity of the individuals involved. This is supplemented by an extensive numerical investigation of the general model, the symmetric model, and nine other special cases. Together the results show that there is a high potential for permanent genetic diversity in the pairwise interaction model, and provide insight into the extent to which various forms of genotypic interactions enhance or reduce this potential. Technically, although two stable polymorphic equilibria are possible, the increased likelihood of maintaining both alleles, and the poor performance of protected polymorphism conditions as a measure of this likelihood, are primarily due to a greater variety and frequency of equilibrium patterns with one stable polymorphic equilibrium, in conjunction with a disproportionately large domain of attraction for stable internal equilibria. PMID:2341034

Feasibility of low-cost magnetic rail designs by integrating ferrite magnets and NdFeB magnets for HTS Maglev systems

NASA Astrophysics Data System (ADS)

Sun, R. X.; Deng, Z. G.; Gou, Y. F.; Li, Y. J.; Zheng, J.; Wang, S. Y.; Wang, J. S.

2015-09-01

Permanent magnet guideway (PMG) is an indispensable part of high temperature superconducting (HTS) Maglev systems. Present PMGs are made of NdFeB magnets with excellent performance and cost much. As another permanent magnet material, the ferrite magnet is weak at magnetic energy product and coercive force, but inexpensive. So, it is a possible way to integrate the ferrite and NdFeB magnets for cutting down the cost of present PMGs. In the paper, the equivalent on magnetic field intensity between ferrite magnets and NdFeB magnets was evaluated by finite element simulation. According to the calculation results, the magnetic field of the PMG integrating ferrite magnets and NdFeB magnets can be increased remarkably comparing with the pure ferrite PMG. It indicates that low-cost PMG designs by integrating the two permanent magnet materials are feasible for the practical HTS Maglev system.

Object permanence in the Goffin cockatoo (Cacatua goffini).

PubMed

Auersperg, Alice M I; Szabo, Birgit; von Bayern, Auguste M P; Bugnyar, Thomas

2014-02-01

The ability to represent hidden objects plays an important role in the survival of many species. In order to provide an inclusive synopsis of the current benchmark tasks used to test object permanence in animals for a psittacine representative, we tested eight Goffin cockatoos (Cacatua goffini) on Stages 3-6 of Piagetian object permanence as well as derivations of spatial transposition, rotation, and translocation tasks. Subjects instantly solved visible displacement 3b and 4a but showed an extended plateau for solving Stage 5a at a very late age (10 months). Subjects readily solved most invisible displacement tasks including double hidings and four angles (90°, 180°, 270°, and 360°) of rotation and translocations at high performance levels, although Piagetian Stage 6 invisible displacement tasks caused more difficulties for the animals than transposition, rotations, and translocation tasks. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Investigation of Anisotropic Bonded Magnets in Permanent Magnet Machine Applications

NASA Astrophysics Data System (ADS)

Khazdozian, H. A.; McCall, S. K.; Kramer, M. J.; Paranthaman, M. P.; Nlebedim, I. C.

Rare earth elements (REE) provide the high energy product necessary for permanent magnets, such as sintered Nd2Fe14B, in many applications like wind energy generators. However, REEs are considered critical materials due to risk in their supply. To reduce the use of critical materials in permanent magnet machines, the performance of anisotropic bonded NdFeB magnets, aligned under varying magnetic field strength, was simulated using 3D finite element analysis in a 3MW direct-drive permanent magnet generator (DDPMG), with sintered N42 magnets used as a baseline for comparison. For direct substitution of the anisotropic bonded magnets, approximately 85% of the efficiency of the baseline model was achieved, irrespective of the alignment field. The torque and power generation of the DDPMG was not found to vary significantly with increase in the alignment field. Finally, design changes were studied to allow for the achievement of rated torque and power with the use of anisotropic bonded magnets, demonstrating the potential for reduction of critical materials in permanent magnets for renewable energy applications. This work was supported by the Critical Materials Institute, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office.

The impact of rare earth cobalt permanent magnets on electromechanical device design

NASA Technical Reports Server (NTRS)

Fisher, R. L.; Studer, P. A.

1979-01-01

Specific motor designs which employ rare earth cobalt magnets are discussed with special emphasis on their unique properties and magnetic field geometry. In addition to performance improvements and power savings, high reliability devices are attainable. Both the mechanism and systems engineering should be aware of the new performance levels which are currently becoming available as a result of the rare earth cobalt magnets.

Cluster expansion modeling and Monte Carlo simulation of alnico 5–7 permanent magnets

DOE PAGES

Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai -Zhuang; ...

2015-03-05

The concerns about the supply and resource of rare earth (RE) metals have generated a lot of interests in searching for high performance RE-free permanent magnets. Alnico alloys are traditional non-RE permanent magnets and have received much attention recently due their good performance at high temperature. In this paper, we develop an accurate and efficient cluster expansion energy model for alnico 5–7. Monte Carlo simulations using the cluster expansion method are performed to investigate the structure of alnico 5–7 at atomistic and nano scales. The alnico 5–7 master alloy is found to decompose into FeCo-rich and NiAl-rich phases at lowmore » temperature. The boundary between these two phases is quite sharp (~2 nm) for a wide range of temperature. The compositions of the main constituents in these two phases become higher when the temperature gets lower. Both FeCo-rich and NiAl-rich phases are in B2 ordering with Fe and Al on α-site and Ni and Co on β-site. The degree of order of the NiAl-rich phase is much higher than that of the FeCo-rich phase. In addition, a small magnetic moment is also observed in NiAl-rich phase but the moment reduces as the temperature is lowered, implying that the magnetic properties of alnico 5–7 could be improved by lowering annealing temperature to diminish the magnetism in NiAl-rich phase. Furthermore, the results from our Monte Carlo simulations are consistent with available experimental results.« less

Cluster expansion modeling and Monte Carlo simulation of alnico 5-7 permanent magnets

NASA Astrophysics Data System (ADS)

Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai-Zhuang; Ho, Kai-Ming

2015-03-01

The concerns about the supply and resource of rare earth (RE) metals have generated a lot of interests in searching for high performance RE-free permanent magnets. Alnico alloys are traditional non-RE permanent magnets and have received much attention recently due their good performance at high temperature. In this paper, we develop an accurate and efficient cluster expansion energy model for alnico 5-7. Monte Carlo simulations using the cluster expansion method are performed to investigate the structure of alnico 5-7 at atomistic and nano scales. The alnico 5-7 master alloy is found to decompose into FeCo-rich and NiAl-rich phases at low temperature. The boundary between these two phases is quite sharp (˜2 nm) for a wide range of temperature. The compositions of the main constituents in these two phases become higher when the temperature gets lower. Both FeCo-rich and NiAl-rich phases are in B2 ordering with Fe and Al on α-site and Ni and Co on β-site. The degree of order of the NiAl-rich phase is much higher than that of the FeCo-rich phase. A small magnetic moment is also observed in NiAl-rich phase but the moment reduces as the temperature is lowered, implying that the magnetic properties of alnico 5-7 could be improved by lowering annealing temperature to diminish the magnetism in NiAl-rich phase. The results from our Monte Carlo simulations are consistent with available experimental results.

30 CFR 816.79 - Protection of underground mining.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Protection of underground mining. 816.79 Section 816.79 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-SURFACE MINING...

30 CFR 816.79 - Protection of underground mining.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Protection of underground mining. 816.79 Section 816.79 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-SURFACE MINING...

Sustaining high performance: dynamic balancing in an otherwise unbalanced system.

PubMed

Wolf, Jason A

2011-01-01

As Ovid said, "There is nothing in the whole world which is permanent." It is this very premise that frames the discoveries in this chapter and the compelling paradox it has raised. What began as a question of how performance is sustained, unveiled a collection of core organizational paradoxes. The findings ultimately suggest that sustained high performance is not a permanent state an organization achieves, but rather it is through perpetual movement and dynamic balance that sustainability occurs. The idea of sustainability as movement is predicated on the ability of organizational members to move beyond the experience of paradox as an impediment to progress. Through holding three critical "movements"--agile/consistency, collective/individualism, and informative/inquiry--not as paradoxical, but as active polarities, the organizations in the study were able to transcend paradox, and take active steps to continuous achievement in outperforming their peers. The study, focused on a collection of hospitals across the Unites States, reveals powerful stories of care and service, of the profound grace of human capacity, and of clear actions taken to create significant results. All of this was achieved in an environment of great volatility, in essence an unbalanced system. It was the discovery of movement and ultimately of dynamic balancing that allowed the organizations to in this study to move beyond stasis to the continuous "state" of sustaining high performance.

High-gradient permanent magnet apparatus and its use in particle collection

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

Cheng, Mengdawn; Ludtka, Gerard Michael; Avens, Larry R.

A high-gradient permanent magnet apparatus for capturing paramagnetic particles, the apparatus comprising: (i) at least two permanent magnets positioned with like poles facing each other; (ii) a ferromagnetic spacer separating the like poles; and (iii) a magnetizable porous filling material in close proximity to the at least two permanent magnets. Also described is a method for capturing paramagnetic particles in which a gas or liquid sample containing the paramagnetic particles is contacted with the high-gradient permanent magnet apparatus described above; wherein, during the contacting step, the gas or liquid sample contacts the magnetizable porous filling material of the high-gradient permanentmore » magnet apparatus, and at least a portion of the paramagnetic particles in the gas or liquid sample is captured on the magnetizable porous filling material.« less

Lévitation magnétique par association d'aimants permanents et de supraconducteurs à haute température critique

NASA Astrophysics Data System (ADS)

Hiebel, P.; Tixador, P.; Chaud, X.

1995-06-01

Since their discovery in the years 1986/87, the high critical temperature superconductors have reached nowadays performances interesting enough to conceive passive magnetic bearings and suspensions which would combined permanent magnets and naturally stable superconducting pellets. After underlining the principal factors that affect the superconductormagnet interaction, different experimental results are given about vertical and axial forces with some stiffness values. The magnetization curve of a superconductor help to understand the hysteretic behavior of the force as a function of the distance between superconductor and magnet. So called simple and hybrid structures of superconducting magnetic suspension are presented. Finally simple numerical simulations allow to draw some interesting conclusions about both geometry and best fitting structure of permanent magnets. Depuis leur découverte dans les années 1986/87, les supraconducteurs à haute température critique ont désormais atteint des performances intéressantes et rendent envisageables des paliers et suspensions magnétiques passives associant aimants permanents et pastilles supraconductrices naturellement stables. Après avoir indiqué les termes importants influençant l'interaction supraconducteur - aimant, différents relevés expérimentaux sont donnés pour les forces verticales et transversales avec quelques valeurs de raideurs. La courbe d'aimantation d'un supraconducteur permet de comprendre le comportement hystérétique de la force en fonction de la distance supraconducteur-aimant. Les structures dites simple et hybride des suspensions magnétiques supraconductrices sont présentées. Enfin quelques simulations numériques simples permettent de dégager quelques conclusions intéressantes quant aux géométries respectives et aux structures d'aimants permanents les mieux adaptées.

30 CFR 819.11 - Auger mining: General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Auger mining: General. 819.11 Section 819.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-AUGER MINING § 819...

30 CFR 819.11 - Auger mining: General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Auger mining: General. 819.11 Section 819.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-AUGER MINING § 819...

Predicting permanent and transient protein-protein interfaces.

PubMed

La, David; Kong, Misun; Hoffman, William; Choi, Youn Im; Kihara, Daisuke

2013-05-01

Protein-protein interactions (PPIs) are involved in diverse functions in a cell. To optimize functional roles of interactions, proteins interact with a spectrum of binding affinities. Interactions are conventionally classified into permanent and transient, where the former denotes tight binding between proteins that result in strong complexes, whereas the latter compose of relatively weak interactions that can dissociate after binding to regulate functional activity at specific time point. Knowing the type of interactions has significant implications for understanding the nature and function of PPIs. In this study, we constructed amino acid substitution models that capture mutation patterns at permanent and transient type of protein interfaces, which were found to be different with statistical significance. Using the substitution models, we developed a novel computational method that predicts permanent and transient protein binding interfaces (PBIs) in protein surfaces. Without knowledge of the interacting partner, the method uses a single query protein structure and a multiple sequence alignment of the sequence family. Using a large dataset of permanent and transient proteins, we show that our method, BindML+, performs very well in protein interface classification. A very high area under the curve (AUC) value of 0.957 was observed when predicted protein binding sites were classified. Remarkably, near prefect accuracy was achieved with an AUC of 0.991 when actual binding sites were classified. The developed method will be also useful for protein design of permanent and transient PBIs. Copyright © 2013 Wiley Periodicals, Inc.

[Object permanence in children with neurological and psychomotor disorders].

PubMed

Pisaturo, C; Frassoni, S; Borreani, A; Battaglia, F; Meruzzi, B

1995-06-01

The aim of this research was to investigate whether the development of object permanence is an available sign of the cognitive development in infants with psychomotor handicaps. Subjects consisted of 5 males, ranging in age from 12 to 33 months, with handicaps as a result of perinatal brain injury. Four were preterm infants. All of the children received psychomotor treatment. Their stage of object permanence was assessed using traditional (B-L) and non traditional test (U-H). (The children's performances on the U-H scales have an "Intrinsic validity"). Four children achieved the first stages of the development of object permanence. The acquisition of object permanence was delayed in comparison with the age-appropriated time, but it may be considered adequate in comparison with the "developmental age" (B-L). One children with severe mental and motor disorders solved no task, the findings suggest that the children with psychomotor handicaps may gain the concept of object permanence and that psychomotor treatment may assist them in the development of the concept. This performance is not age-dependent. So the acquisition of the concept of object permanence may be considered an accurate and sensitive tool for the follow-up of the sensorimotor development in the handicapped children.

Performance on a Stage IV Object-Permanence Task with Standard and Nonstandard Covers.

ERIC Educational Resources Information Center

And Others; Rader, Nancy

1979-01-01

Examined the role of perceptual-motor development in a typical Stage IV task. The performance of ten infants was compared on a Stage IV object permanence task when a cloth cover was used and when a small card cover was used. (JMB)

30 CFR 828.12 - In situ processing: Monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Monitoring. 828.12 Section... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ processing...

30 CFR 828.12 - In situ processing: Monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false In situ processing: Monitoring. 828.12 Section... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ processing...

30 CFR 828.12 - In situ processing: Monitoring.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false In situ processing: Monitoring. 828.12 Section... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ processing...

30 CFR 828.12 - In situ processing: Monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false In situ processing: Monitoring. 828.12 Section... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ processing...

30 CFR 828.12 - In situ processing: Monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false In situ processing: Monitoring. 828.12 Section... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ processing...

Time to tenure in Spanish universities: an event history analysis.

PubMed

Sanz-Menéndez, Luis; Cruz-Castro, Laura; Alva, Kenedy

2013-01-01

Understanding how institutional incentives and mechanisms for assigning recognition shape access to a permanent job is important. This study, based on data from questionnaire survey responses and publications of 1,257 university science, biomedical and engineering faculty in Spain, attempts to understand the timing of getting a permanent position and the relevant factors that account for this transition, in the context of dilemmas between mobility and permanence faced by organizations. Using event history analysis, the paper looks at the time to promotion and the effects of some relevant covariates associated to academic performance, social embeddedness and mobility. We find that research productivity contributes to career acceleration, but that other variables are also significantly associated to a faster transition. Factors associated to the social elements of academic life also play a role in reducing the time from PhD graduation to tenure. However, mobility significantly increases the duration of the non-tenure stage. In contrast with previous findings, the role of sex is minor. The variations in the length of time to promotion across different scientific domains is confirmed, with faster career advancement for those in the Engineering and Technological Sciences compared with academics in the Biological and Biomedical Sciences. Results show clear effects of seniority, and rewards to loyalty, in addition to some measurements of performance and quality of the university granting the PhD, as key elements speeding up career advancement. Findings suggest the existence of a system based on granting early permanent jobs to those that combine social embeddedness and team integration with some good credentials regarding past and potential future performance, rather than high levels of mobility.

Time to Tenure in Spanish Universities: An Event History Analysis

PubMed Central

Sanz-Menéndez, Luis; Cruz-Castro, Laura; Alva, Kenedy

2013-01-01

Understanding how institutional incentives and mechanisms for assigning recognition shape access to a permanent job is important. This study, based on data from questionnaire survey responses and publications of 1,257 university science, biomedical and engineering faculty in Spain, attempts to understand the timing of getting a permanent position and the relevant factors that account for this transition, in the context of dilemmas between mobility and permanence faced by organizations. Using event history analysis, the paper looks at the time to promotion and the effects of some relevant covariates associated to academic performance, social embeddedness and mobility. We find that research productivity contributes to career acceleration, but that other variables are also significantly associated to a faster transition. Factors associated to the social elements of academic life also play a role in reducing the time from PhD graduation to tenure. However, mobility significantly increases the duration of the non-tenure stage. In contrast with previous findings, the role of sex is minor. The variations in the length of time to promotion across different scientific domains is confirmed, with faster career advancement for those in the Engineering and Technological Sciences compared with academics in the Biological and Biomedical Sciences. Results show clear effects of seniority, and rewards to loyalty, in addition to some measurements of performance and quality of the university granting the PhD, as key elements speeding up career advancement. Findings suggest the existence of a system based on granting early permanent jobs to those that combine social embeddedness and team integration with some good credentials regarding past and potential future performance, rather than high levels of mobility. PMID:24116199

30 CFR 817.61 - Use of explosives: General requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... underground mines. (2) The blast design may be presented as part of a permit application or at a time, before... airblast, flyrock, and ground-vibration standards in § 817.67. (4) The blast design shall be prepared and... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING...

Design and analysis of a direct-drive wind power generator with ultra-high torque density

NASA Astrophysics Data System (ADS)

Jian, Linni; Shi, Yujun; Wei, Jin; Zheng, Yanchong

2015-05-01

In order to get rid of the nuisances caused by mechanical gearboxes, generators with low rated speed, which can be directly connected to wind turbines, are attracting increasing attention. The purpose of this paper is to propose a new direct-drive wind power generator (DWPG), which can offer ultra-high torque density. First, magnetic gear (MG) is integrated to achieve non-contact torque transmission and speed variation. Second, armature windings are engaged to achieve electromechanical energy conversion. Interior permanent magnet (PM) design on the inner rotor is adopted to boost the torque transmission capability of the integrated MG. Nevertheless, due to lack of back iron on the stator, the proposed generator does not exhibit prominent salient feature, which usually exists in traditional interior PM (IPM) machines. This makes it with good controllability and high power factor as the surface-mounted permanent magnet machines. The performance is analyzed using finite element method. Investigation on the magnetic field harmonics demonstrates that the permanent-magnetic torque offered by the MG can work together with the electromagnetic torque offered by the armature windings to balance the driving torque captured by the wind turbine. This allows the proposed generator having the potential to offer even higher torque density than its integrated MG.

High performance hybrid magnetic structure for biotechnology applications

DOEpatents

Humphries, David E; Pollard, Martin J; Elkin, Christopher J

2005-10-11

The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

High performance hybrid magnetic structure for biotechnology applications

DOEpatents

Humphries, David E.; Pollard, Martin J.; Elkin, Christopher J.

2006-12-12

The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

Magnetic nanostructuring and overcoming Brown's paradox to realize extraordinary high-temperature energy products

NASA Astrophysics Data System (ADS)

Balasubramanian, Balamurugan; Mukherjee, Pinaki; Skomski, Ralph; Manchanda, Priyanka; Das, Bhaskar; Sellmyer, David J.

2014-09-01

Nanoscience has been one of the outstanding driving forces in technology recently, arguably more so in magnetism than in any other branch of science and technology. Due to nanoscale bit size, a single computer hard disk is now able to store the text of 3,000,000 average-size books, and today's high-performance permanent magnets--found in hybrid cars, wind turbines, and disk drives--are nanostructured to a large degree. The nanostructures ideally are designed from Co- and Fe-rich building blocks without critical rare-earth elements, and often are required to exhibit high coercivity and magnetization at elevated temperatures of typically up to 180 °C for many important permanent-magnet applications. Here we achieve this goal in exchange-coupled hard-soft composite films by effective nanostructuring of high-anisotropy HfCo7 nanoparticles with a high-magnetization Fe65Co35 phase. An analysis based on a model structure shows that the soft-phase addition improves the performance of the hard-magnetic material by mitigating Brown's paradox in magnetism, a substantial reduction of coercivity from the anisotropy field. The nanostructures exhibit a high room-temperature energy product of about 20.3 MGOe (161.5 kJ/m3), which is a record for a rare earth- or Pt-free magnetic material and retain values as high as 17.1 MGOe (136.1 kJ/m3) at 180°C.

Design and Experimental Validation for Direct-Drive Fault-Tolerant Permanent-Magnet Vernier Machines

PubMed Central

Liu, Guohai; Yang, Junqin; Chen, Ming; Chen, Qian

2014-01-01

A fault-tolerant permanent-magnet vernier (FT-PMV) machine is designed for direct-drive applications, incorporating the merits of high torque density and high reliability. Based on the so-called magnetic gearing effect, PMV machines have the ability of high torque density by introducing the flux-modulation poles (FMPs). This paper investigates the fault-tolerant characteristic of PMV machines and provides a design method, which is able to not only meet the fault-tolerant requirements but also keep the ability of high torque density. The operation principle of the proposed machine has been analyzed. The design process and optimization are presented specifically, such as the combination of slots and poles, the winding distribution, and the dimensions of PMs and teeth. By using the time-stepping finite element method (TS-FEM), the machine performances are evaluated. Finally, the FT-PMV machine is manufactured, and the experimental results are presented to validate the theoretical analysis. PMID:25045729

Side-suspended High-Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

NASA Astrophysics Data System (ADS)

Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

2017-07-01

High-T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 103 Pa.

Hair cortisol predicts object permanence performance in infant rhesus macaques (Macaca mulatta).

PubMed

Dettmer, Amanda M; Novak, Matthew F S X; Novak, Melinda A; Meyer, Jerrold S; Suomi, Stephen J

2009-12-01

Although high circulating levels of glucocorticoids are associated with impaired cognitive performance in adults, less is known about this relationship in infancy. Furthermore, because studies have relied on acute cortisol measures in blood plasma or saliva, interpretation of the results may be difficult as acute measures may in part reflect emotional responses to testing procedures. In this study we examined whether hair cortisol, an integrated measure of hypothalamic-pituitary-adrenal (HPA) axis functioning, predicted performance of nursery-reared (NR) infant rhesus monkeys (n = 32) on Piagetian object permanence tasks. Testing of NR infants began at 19.8 +/- 2.2 (mean +/- SE) days of age and continued for the next several months. Hair cortisol concentrations from the 32 NR monkeys were compared to those of 20 mother-peer-reared (MPR) infants. Hair was shaved at Day 14, allowed to regrow, and obtained again at month 6, thus representing integrated cortisol over a 5.5-month period of time. NR and MPR infants did not differ in month 6 hair cortisol values (t((50)) = 0.02, p = 0.98). Linear regression revealed that hair cortisol predicted object permanence performance in the NR infants. Infants with higher hair cortisol reached criterion at later ages on the well (p < 0.01), screen (p < 0.05), and A-not-B (p < 0.05) tasks and required more test sessions to complete the well (p < 0.01) and screen tasks (p < 0.05). These data are the first to implicate hair cortisol as a reliable predictor of early cognitive performance in infant macaque monkeys.

Hair Cortisol Predicts Object Permanence Performance in Infant Rhesus Macaques (Macaca mulatta)

PubMed Central

Dettmer, Amanda M.; Novak, Matthew F.S.X.; Novak, Melinda A.; Meyer, Jerrold S.; Suomi, Stephen J.

2009-01-01

Although high circulating levels of glucocorticoids are associated with impaired cognitive performance in adults, less is known about this relationship in infancy. Furthermore, because studies have relied on acute cortisol measures in blood plasma or saliva, interpretation of the results may be difficult as acute measures may in part reflect emotional responses to testing procedures. In this study we examined whether hair cortisol, an integrated measure of HPA axis functioning, predicted performance of nursery-reared (NR) infant rhesus monkeys (N=32) on Piagetian object permanence tasks. Testing of NR infants began at 19.8±2.2 (mean±SE) days of age and continued for the next several months. Hair cortisol concentrations from the 32 NR monkeys were compared to those of 20 mother-peer-reared (MPR) infants. Hair was shaved at day 14, allowed to re-grow, and obtained again at month 6, thus representing integrated cortisol over a 5.5-month period of time. NR and MPR infants did not differ in month 6 hair cortisol values (t(50)=0.02, p=0.98). Linear regression revealed that hair cortisol predicted object permanence performance in the NR infants. Infants with higher hair cortisol reached criterion at later ages on the well (p<0.01), screen (p<0.05), and A-not-B (p<0.05) tasks and required more test sessions to complete the well (p<0.01) and screen tasks (p<0.05). These data are the first to implicate hair cortisol as a reliable predictor of early cognitive performance in infant macaque monkeys. PMID:19771550

Operational characteristics of energy storage high temperature superconducting flywheels considering time dependent processes

NASA Astrophysics Data System (ADS)

Vajda, Istvan; Kohari, Zalan; Porjesz, Tamas; Benko, Laszlo; Meerovich, V.; Sokolovsky; Gawalek, W.

2002-08-01

Technical and economical feasibilities of short-term energy storage flywheels with high temperature superconducting (HTS) bearing are widely investigated. It is essential to reduce the ac losses caused by magnetic field variations in HTS bulk disks/rings (levitators) used in the magnetic bearings of flywheels. For the HTS bearings the calculation and measurement of the magnetic field distribution were performed. Effects like eccentricity, tilting were measured. Time dependency of the levitation force following a jumpwise movement of the permanent magnet was measured. The results were used to setup an engineering design algorithm for energy storage HTS flywheels. This algorithm was applied to an experimental HTS flywheel model with a disk type permanent magnet motor/generator unit designed and constructed by the authors. A conceptual design of the disk-type motor/generator with radial flux is shown.

New permanent magnets

NASA Astrophysics Data System (ADS)

Müller, K.-H.; Krabbes, G.; Fink, J.; Gruß, S.; Kirchner, A.; Fuchs, G.; Schultz, L.

2001-05-01

Permanent magnets play an important role and are widely spread in daily-life applications. Due to their very low costs, large availability of the row materials and their high chemical stability, hard ferrites are still dominant in the permanent magnet market although their relatively poor magnetic properties are a distinct disadvantage. Today's high-performance magnets are mostly made from Nd 2Fe 14B. The aim of research is to combine the large spontaneous magnetization of 3d metals with strong anisotropy fields known from rare-earth transition-metal compounds and, at the same time, to maintain a high value of the Curie temperature. However, the number of iron-rich rare-earth intermetallics is very limited and, consequently, not much success can be noted in this field for the last 10 years. One alternative concept is to use magnetic fields trapped in type II superconductors where much higher fields can be achieved compared to conventional rare-earth magnets. Very recently, we obtained a trapped field as high as 14.4 T in a melt-textured YBCO bulk sample of a few centimeters in diameter. This is the highest value ever achieved in a bulk superconductor. The trapped field of a superconductor is not governed by the Laplace equation and, therefore, levitation works without any additional (active) stabilization. The disadvantage of these magnets is their low working temperature (of liquid nitrogen and below).

Early Working Memory in Children Born With Extremely Low Birth Weight: Assessed by Object Permanence

PubMed Central

Lowe, Jean; MacLean, Peggy C.; Shaffer, Michele L.; Watterberg, Kristi

2011-01-01

Object permanence is considered the earliest method for assessing working memory. Factors affecting object permanence performance in a sample of two hundred and thirty-three 18- to 22-month olds born with extremely low birth weight were examined. It was hypothesized that object permanence would be directly related to emotional and attention regulation, that children with lower birth weight and higher illness severity would have more difficulty on the object permanence task, and that no ethnic/racial differences would be found, as this is considered a culturally unbiased task. Attainment of object permanence had a significant positive association with emotional and attention regulation, even after controlling the medical severity and socioeconomic factors. More girls than boys passed the object permanence items. There was no ethnic/racial difference on object permanence. Our findings indicate that object permanence may be a culturally fair way of assessing development, and emotional and attention regulation are potential avenues of intervention for such skill. PMID:19339284

Early working memory in children born with extremely low birth weight: assessed by object permanence.

PubMed

Lowe, Jean; MacLean, Peggy C; Shaffer, Michele L; Watterberg, Kristi

2009-04-01

Object permanence is considered the earliest method for assessing working memory. Factors affecting object permanence performance in a sample of two hundred and thirty-three 18- to 22-month olds born with extremely low birth weight were examined. It was hypothesized that object permanence would be directly related to emotional and attention regulation, that children with lower birth weight and higher illness severity would have more difficulty on the object permanence task, and that no ethnic/racial differences would be found, as this is considered a culturally unbiased task. Attainment of object permanence had a significant positive association with emotional and attention regulation, even after controlling the medical severity and socioeconomic factors. More girls than boys passed the object permanence items. There was no ethnic/racial difference on object permanence. Our findings indicate that object permanence may be a culturally fair way of assessing development, and emotional and attention regulation are potential avenues of intervention for such skill.

Alternatives to Rare Earth Permanent Magnets for Energy Harvesting Applications

NASA Astrophysics Data System (ADS)

Khazdozian, Helena; Hadimani, Ravi; Jiles, David

Direct-drive permanent magnet generators (DDPMGs) offer increased reliability and efficiency over the more commonly used geared doubly-fed induction generator, yet are only employed in less than 1 percent of utility scale wind turbines in the U.S. One major barrier to increased deployment of DDPMGs in the U.S. wind industry is NdFeB permanent magnets (PMs), which contain critical rare earth elements Nd and Dy. To allow for the use of rare earth free PMs, the magnetic loading, defined as the average magnetic flux density over the rotor surface, must be maintained. Halbach cylinders are employed in 3.5kW Halbach PMGs (HPMGs) of varying slot-to-pole ratio to concentrate the magnetic flux output by a lower energy density PM over the rotor surface. We found that for high pole and slot number, the increase in magnetic loading is sufficient to allow for the use of strontium iron oxide hard ferrite PMs and achieved rated performance. Joule losses in the stator windings were found to increase for the hard ferrite PMs due to increased inductance in the stator windings. However, for scaling of the HPMG designs to 3MW, rated performance and high efficiency were achieved, demonstrating the potential for elimination for rare earth PMs in commercial scale wind turbines. This work was supported by the National Science Foundation under Grant No. 1069283 and a Barbara and James Palmer Endowment at Iowa State University.

Combinatorial search of rare-earth free permanent magnets

NASA Astrophysics Data System (ADS)

Gao, Tieren; Takeuchi, Ichiro; Fackler, Sean; Fang, Lei; Zhang, Ying; Krammer, Matthew; Anderson, Iver; McCallum, Bill; University of Maryland Collaboration; Ames Laboratory Collaboration

2013-03-01

Permanent magnets play important roles in modern technologies such as in generators, motors, speakers, and relays. Today's high performance permanent magnets contain at least one rare earth element such as Nd, Sm, Pr and Dy. However, rare earth elements are increasingly rare and expensive, and alternative permanent magnet materials which do not contain them are needed by the industry. We are using the thin film composition spread technique to explore novel compositions of permanent magnets without rare-earth. Ternary co-sputtering is used to generate composition spreads. We have thus far looked at Mo doped Fe-Co as one of the initial systems to search for possible compounds with enhanced coercive fields. The films were deposited on Si (100) substrates and annealed at different temperatures. The structural properties of films are mapped by synchrotron diffraction. We find that there is a structural transition from a crystalline to an amorphous state at about 20% atomic Mo. With increasing annealing temperature, the Mo onset concentration of the structural transition increases from 25% for 600°C to 35% for 700°C. We find that some of compounds display enhanced coercive field. With increasing Mo concentration, the magnetization of Fe-Co-Mo begins to switch from in-plane to out-of-plane direction. This work is funded by the BREM (Beyond Rare-earth Magnet) project (DOE EERE).

Dysprosium-free melt-spun permanent magnets.

PubMed

Brown, D N; Wu, Z; He, F; Miller, D J; Herchenroeder, J W

2014-02-12

Melt-spun NdFeB powders can be formed into a number of different types of permanent magnet for a variety of applications in electronics, automotive and clean technology industries. The melt-spinning process produces flake powder with a fine uniform array of nanoscale Nd2Fe14B grains. These powders can be net-shape formed into isotropic polymer-bonded magnets or hot formed into fully dense magnets. This paper discusses the influence of heavy rare earth elements and microstructure on the magnetic performance, thermal stability and material cost of NdFeB magnets. Evidence indicates that melt-spun nanocrystalline NdFeB magnets are less dependent on heavy rare earth elements for high-temperature performance than the alternative coarser-grained sintered NdFeB magnets. In particular, hot-pressed melt-spun magnets are an attractive low-cost solution for applications that require thermal stability up to 175-200 °C.

Data Retention Policy | High-Performance Computing | NREL

Science.gov Websites

HPC Data Retention Policy. File storage areas on Peregrine and Gyrfalcon are either user-centric to reclaim storage. We can make special arrangements for permanent storage, if needed. User-Centric > is 3 months after the last project ends. During this retention period, the user may log in to

Design, fabrication and characterization of an arrayable all-polymer microfluidic valve employing highly magnetic rare-earth composite polymer

NASA Astrophysics Data System (ADS)

Rahbar, Mona; Shannon, Lesley; Gray, Bonnie L.

2016-05-01

We present a new magnetically actuated microfluidic valve that employs a highly magnetic composite polymer (M-CP) containing rare-earth hard-magnetic powder for its actuating element and for its valve seat. The M-CP offers much higher magnetization compared to the soft-magnetic, ferrite-based composite polymers typically used in microfluidic applications. Each valve consists of a permanently magnetized M-CP flap and valve seat mounted on a microfluidic channel system fabricated in poly(dimethylsiloxane) (PDMS). Each valve is actuated under a relatively small external magnetic field of 80 mT provided by a small permanent magnet mounted on a miniature linear actuator. The performance of the valve with different flap thicknesses is characterized. In addition, the effect of the magnetic valve seat on the valve’s performance is also characterized. It is experimentally shown that a valve with a 2.3 mm flap thickness, actuated under an 80 mT magnetic field, is capable of completely blocking liquid flow at a flow rate of 1 ml min-1 for pressures up to 9.65 kPa in microfluidic channels 200 μm wide and 200 μm deep. The valve can also be fabricated into an array for flow switching between multiple microfluidic channels under continuous flow conditions. The performance of arrays of valves for flow routing is demonstrated for flow rates up to 5 ml min-1 with larger microfluidic channels of up to 1 mm wide and 500 μm deep. The design of the valves is compatible with other commonly used polymeric microfluidic components, as well as other components that use the same novel permanently magnetic composite polymer, such as our previously reported cilia-based mixing devices.

40 CFR 60.536 - Permanent label, temporary label, and owner's manual.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Performance for New Residential Wood Heaters § 60.536 Permanent label, temporary label, and owner's manual. (a... section. (2) Except for wood heaters subject to § 60.530 (e), (f), or (g), the permanent label shall... material expected to last the lifetime of the wood heater, (iv) Present required information in a manner so...

40 CFR 60.536 - Permanent label, temporary label, and owner's manual.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Performance for New Residential Wood Heaters § 60.536 Permanent label, temporary label, and owner's manual. (a... section. (2) Except for wood heaters subject to § 60.530 (e), (f), or (g), the permanent label shall... material expected to last the lifetime of the wood heater, (iv) Present required information in a manner so...

40 CFR 60.536 - Permanent label, temporary label, and owner's manual.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Performance for New Residential Wood Heaters § 60.536 Permanent label, temporary label, and owner's manual. (a... section. (2) Except for wood heaters subject to § 60.530 (e), (f), or (g), the permanent label shall... material expected to last the lifetime of the wood heater, (iv) Present required information in a manner so...

40 CFR 60.536 - Permanent label, temporary label, and owner's manual.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Performance for New Residential Wood Heaters § 60.536 Permanent label, temporary label, and owner's manual. (a... section. (2) Except for wood heaters subject to § 60.530 (e), (f), or (g), the permanent label shall... material expected to last the lifetime of the wood heater, (iv) Present required information in a manner so...

40 CFR 60.536 - Permanent label, temporary label, and owner's manual.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Performance for New Residential Wood Heaters § 60.536 Permanent label, temporary label, and owner's manual. (a... section. (2) Except for wood heaters subject to § 60.530 (e), (f), or (g), the permanent label shall... material expected to last the lifetime of the wood heater, (iv) Present required information in a manner so...

Design of a Permanent-Magnet Zeeman Slower

NASA Astrophysics Data System (ADS)

Adler, Charles; Narducci, Frank; Sukenik, Charles; Mulholland, Jonathan; Goodale, Sarah

2006-05-01

During the past decade, low cost, flexible, and highly-polarized magnetic field sheet material has become available with field strengths useful for applications in modern atomic physics experiments. One advantage of using such material is that it can easily be cut to almost any desired shape without appreciable loss of field strength making it more versatile than ceramic magnets. We present the design of a Zeeman slower, made from such material, for cooling an atomic beam of neutral rubidium atoms and discuss results from an atomic beam trajectory simulation which indicates that the slower should perform well. We will also report on progress of a prototype permanent magnet Zeeman slower presently under construction in the laboratory.

Bearing design for flywheel energy storage using high-TC superconductors

DOEpatents

Hull, John R.; Mulcahy, Thomas M.

2000-01-01

A high temperature superconductor material bearing system (38) This system (38) includes a rotor (50) having a ring permanent magnet (60), a plurality of permanent magnets (16, 20 and 70) for interacting to generate levitation forces for the system (38). This group of magnets are a push/pull bearing (75). A high temperature superconductor structure (30) interacts with the ting permanent magnet (60) to provide stabilizing forces for the system (38).

Performance Characterization of a Novel Plasma Thruster to Provide a Revolutionary Operationally Responsive Space Capability with Micro- and Nano-Satellites

DTIC Science & Technology

2011-03-24

and radiation resistance of rare earth permanent magnets for applications such as ion thrusters and high efficiency Stirling Radioisotope Generators...from Electron Transitioning Discharge Current Discharge Power Discharge Voltage Θ Divergence Angle Earths Gravity at Sea Level...Hall effect thruster HIVAC High Voltage Hall Accelerator LEO Low Earth Orbit LDS Laser Displacement System LVDT Linear variable differential

High energy product permanent magnet having improved intrinsic coercivity and method of making same

DOEpatents

Ramesh, Ramamoorthy; Thomas, Gareth

1990-01-01

A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture. The compressed mixture is then sintered at a temperature above the melting point of the sintering aid and below the melting point of the permanent magnet alloy to thereby coat the particle surfaces of the permanent magnetic alloy particles with the sintering aid while inhibiting migration of the rare earth element in the sintering aid into the permanent magnet alloy particles to thereby raise the intrinsic coercivity of the permanent magnet alloy without substantially lowering the high energy of the permanent magnet alloy.

Uneven Hedging of Economic Risks for a Skilled Workforce: Are Immigrants Disadvantaged?

PubMed Central

Hao, Lingxin; Warkentien, Siri

2015-01-01

Skilled immigration to the United States has been multi-channeled via legislations on permanent and temporary visa programs. This paper argues that skilled immigrants were not disadvantaged during the Great Recession because of a new hedging mechanism, which starts with the federal legislations that admit skilled nonimmigrants, proceeds to vest authority in employers, who perform rigorous screening and selection of temporary workers for future permanency, and ends with greater protection of those selected. To test this mechanism, the paper examines skilled immigrants’ spatial mobility out of the country and their domestic labor market outcomes. The paper presents evidence from analyzing repeated, nationally representative survey data of college graduates in the US using demographic techniques of intra-cohort and inter-cohort analyses. The major findings about the substantial cross-border mobility and high levels of labor force participation among at-entry temporary visa holders who later gained permanent residency provide strong evidence to support our proposed new hedging mechanism. PMID:27605891

Interfacial Phenomena of Magnetic Fluid with Permanent Magnet in a Longitudinally Excited Container

NASA Astrophysics Data System (ADS)

Sudo, Seiichi; Wakuda, Hirofumi; Yano, Tetsuya

2008-02-01

This paper describes the magnetic fluid sloshing in a longitudinally excited container. Liquid responses of magnetic fluid with a permanent magnet in a circular cylindrical container subject to vertical vibration are investigated. Experiments are performed on a vibration- testing system which provided longitudinal excitation. A cylindrical container made with the acrylic plastic is used in the experiment. A permanent magnet is in the state of floating in a magnetic fluid. The disk-shaped and ring-shaped magnets are examined. The different interfacial phenomena from the usual longitudinal liquid sloshing are observed. It is found that the wave motion frequency of magnetic fluid with a disk-shaped magnet in the container subject to vertical vibration is exactly same that of the excitation. In the case of ring-shaped magnet, the first symmetrical mode of one-half subharmonic response is dominant at lower excitation frequencies. The magnetic fluid disintegration of the free surface was also observed by a high-speed video camera system.

Comparisons in Performance of Electromagnet and Permanent-Magnet Cylindrical Hall-Effect Thrusters

NASA Technical Reports Server (NTRS)

Polzin, K. A.; Raitses, Y.; Gayoso, J. C.; Fisch, N. J.

2010-01-01

Three different low-power cylindrical Hall thrusters, which more readily lend themselves to miniaturization and low-power operation than a conventional (annular) Hall thruster, are compared to evaluate the propulsive performance of each. One thruster uses electromagnet coils to produce the magnetic field within the discharge channel while the others use permanent magnets, promising power reduction relative to the electromagnet thruster. A magnetic screen is added to the permanent magnet thruster to improve performance by keeping the magnetic field from expanding into space beyond the exit of the thruster. The combined dataset spans a power range from 50-350 W. The thrust levels over this range were 1.3-7.3 mN, with thruster efficiencies and specific impulses spanning 3.5-28.7% and 400-1940 s, respectively. The efficiency is generally higher for the permanent magnet thruster with the magnetic screen, while That thruster s specific impulse as a function of discharge voltage is comparable to the electromagnet thruster.

A field-cancellation algorithm for constructing economical planar permanent magnet (PM) multipoles with large high-quality field apertures

NASA Astrophysics Data System (ADS)

Tatchyn, Roman

1997-05-01

In recent years studies have been initiated on a new class of multipole field generators consisting of cuboid planar permanent magnet (PM) pieces arranged in bi-planar arrays of 2-fold rotational symmetry(R. Tatchyn, "Planar Permanent Magnet Multipoles: for Particle Accelerator and Storage Ring Applications ," IEEE Trans. Mag. 30, 5050(1994).)(T. Cremer, R. Tatchyn, "Planar Permanent Magnet Multipoles: Measurements and Configurations," in Proceedings of the 1995 Particle Accelerator Conference, IEEE Catalog No. 95CH35843, paper FAQ-20.). These structures, first introduced for Free Electron Laser (FEL) applications(R. Tatchyn, "Selected applications of planar permanent magnet multipoles in FEL insertion device design," NIM A341, 449(1994).), are based on reducing the rotational symmetry of conventional N-pole field generators from N-fold to 2-fold. One consequence of this reduction is a large higher-multipole content in a planar PM multipole's field at distances relatively close to the structure's axis, making it generally unsuitable for applications requiring a large high-quality field aperture. In this paper we outline an economical field-cancellation algorithm that can substantially decrease the harmonic content of a planar PM's field without breaking its biplanar geometry or 2-fold rotational symmetry. This will enable planar PM multipoles to be employed in a broader range of applications than heretofore possible, in particular as distributed focusing elements installed in insertion device gaps on synchrotron storage rings. This accomplishment is expected to remove the conventional restriction of an insertion device's length to the scale of the local focusing beta, enabling short-period, small-gap undulators to be installed and operated as high-brightness sources on lower-energy storage rings(R. Tatchyn, P. Csonka, A. Toor, "Perspectives on micropole undulators in synchrotron radiation technology," Rev. Sci. Instrum. 60(7), 1796(1989).). Operation as ordinary focusing elements in storage ring magnetic lattices, as well as the performance of other high-quality multipole applications, should also becomes possible with the realization of the proposed structures.

Tuning the Magnetic Properties and Structural Stabilities of the 2-17-3 Magnets Sm2Fe17X3 (X =C , N) by Substituting La or Ce for Sm

NASA Astrophysics Data System (ADS)

Pandey, Tribhuwan; Du, Mao-Hua; Parker, David S.

2018-03-01

Designing a permanent magnet with reduced critical rare-earth content is of paramount importance in the development of cost-effective modern technologies. By performing comprehensive first-principles calculations, we investigate the potential avenues for reducing the critical rare-earth content in Sm2Fe17N3 and Sm2Fe17C3 by making a La or Ce substitution for Sm. The calculated magnetic properties of base compounds are in good agreement with the previous low-temperature (4.2-K) experimental measurements, and they show a large axial anisotropy. Although La or Ce substitution results in a slight reduction of magnetic anisotropy, the magnetic moments of Fe atoms mostly remain unchanged. Specifically, large axial anisotropies of 7.2 and 4.1 MJ /m3 are obtained for SmCeFe17 N3 and SmLaFe17 N3 , respectively. These values of anisotropies are comparable to the state-of-the-art permanent magnet Nd2 Fe14 B . The foremost limitation of Sm2 Fe17X3 magnets for practical application is the formation nitrogen or carbon vacancies at high temperatures. By calculating the N- (C)- vacancy formation energy, we show that La or Ce substitution enhances the vacancy formation energy. This enhanced vacancy formation energy will likely improve the thermodynamic stability of these alloys at high temperatures. Therefore, La- or Ce-substituted Sm2Fe17C3 and Sm2Fe17N3 compounds are promising candidates for high-performance permanent magnets with substantially reduced rare-earth content.

Tuning the Magnetic Properties and Structural Stabilities of the 2-17-3 Magnets Sm 2Fe 17X 3 (X=C, N) by Substituting La or Ce for Sm

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

Pandey, Tribhuwan; Du, Mao-Hua; Parker, David S.

Designing a permanent magnet with reduced critical rare-earth content is of paramount importance in the development of cost-effective modern technologies. By performing comprehensive first-principles calculations, we investigate the potential avenues for reducing the critical rare-earth content in Sm 2Fe 17N 3 and Sm 2Fe 17C 3 by making a La or Ce substitution for Sm. The calculated magnetic properties of base compounds are in good agreement with the previous low-temperature (4.2-K) experimental measurements, and they show a large axial anisotropy. Although La or Ce substitution results in a slight reduction of magnetic anisotropy, the magnetic moments of Fe atoms mostlymore » remain unchanged. Specifically, large axial anisotropies of 7.2 and 4.1 MJ/m 3 are obtained for SmCeFe 17N 3 and SmLaFe 17N 3, respectively. These values of anisotropies are comparable to the state-of-the-art permanent magnet Nd 2Fe 14B. The foremost limitation of Sm 2Fe 17X 3 magnets for practical application is the formation nitrogen or carbon vacancies at high temperatures. By calculating the N- (C)- vacancy formation energy, we show that La or Ce substitution enhances the vacancy formation energy. Here, this enhanced vacancy formation energy will likely improve the thermodynamic stability of these alloys at high temperatures. Therefore, La- or Ce-substituted Sm 2Fe 17C 3 and Sm 2Fe 17N 3 compounds are promising candidates for high-performance permanent magnets with substantially reduced rare-earth content.« less

Tuning the Magnetic Properties and Structural Stabilities of the 2-17-3 Magnets Sm 2Fe 17X 3 (X=C, N) by Substituting La or Ce for Sm

DOE PAGES

Pandey, Tribhuwan; Du, Mao-Hua; Parker, David S.

2018-03-05

Designing a permanent magnet with reduced critical rare-earth content is of paramount importance in the development of cost-effective modern technologies. By performing comprehensive first-principles calculations, we investigate the potential avenues for reducing the critical rare-earth content in Sm 2Fe 17N 3 and Sm 2Fe 17C 3 by making a La or Ce substitution for Sm. The calculated magnetic properties of base compounds are in good agreement with the previous low-temperature (4.2-K) experimental measurements, and they show a large axial anisotropy. Although La or Ce substitution results in a slight reduction of magnetic anisotropy, the magnetic moments of Fe atoms mostlymore » remain unchanged. Specifically, large axial anisotropies of 7.2 and 4.1 MJ/m 3 are obtained for SmCeFe 17N 3 and SmLaFe 17N 3, respectively. These values of anisotropies are comparable to the state-of-the-art permanent magnet Nd 2Fe 14B. The foremost limitation of Sm 2Fe 17X 3 magnets for practical application is the formation nitrogen or carbon vacancies at high temperatures. By calculating the N- (C)- vacancy formation energy, we show that La or Ce substitution enhances the vacancy formation energy. Here, this enhanced vacancy formation energy will likely improve the thermodynamic stability of these alloys at high temperatures. Therefore, La- or Ce-substituted Sm 2Fe 17C 3 and Sm 2Fe 17N 3 compounds are promising candidates for high-performance permanent magnets with substantially reduced rare-earth content.« less

Maximization of permanent trapping of CO{sub 2} and co-contaminants in the highest-porosity formations of the Rock Springs Uplift (Southwest Wyoming): experimentation and multi-scale modeling

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

Piri, Mohammad

2014-03-31

Under this project, a multidisciplinary team of researchers at the University of Wyoming combined state-of-the-art experimental studies, numerical pore- and reservoir-scale modeling, and high performance computing to investigate trapping mechanisms relevant to geologic storage of mixed scCO{sub 2} in deep saline aquifers. The research included investigations in three fundamental areas: (i) the experimental determination of two-phase flow relative permeability functions, relative permeability hysteresis, and residual trapping under reservoir conditions for mixed scCO{sub 2}-­brine systems; (ii) improved understanding of permanent trapping mechanisms; (iii) scientifically correct, fine grid numerical simulations of CO{sub 2} storage in deep saline aquifers taking into account themore » underlying rock heterogeneity. The specific activities included: (1) Measurement of reservoir-­conditions drainage and imbibition relative permeabilities, irreducible brine and residual mixed scCO{sub 2} saturations, and relative permeability scanning curves (hysteresis) in rock samples from RSU; (2) Characterization of wettability through measurements of contact angles and interfacial tensions under reservoir conditions; (3) Development of physically-­based dynamic core-­scale pore network model; (4) Development of new, improved high-­performance modules for the UW-­team simulator to provide new capabilities to the existing model to include hysteresis in the relative permeability functions, geomechanical deformation and an equilibrium calculation (Both pore-­ and core-­scale models were rigorously validated against well-­characterized core-­ flooding experiments); and (5) An analysis of long term permanent trapping of mixed scCO{sub 2} through high-­resolution numerical experiments and analytical solutions. The analysis takes into account formation heterogeneity, capillary trapping, and relative permeability hysteresis.« less

A study of generator performance with linear permanent magnet in various coil configuration and rotor-stator geometry

NASA Astrophysics Data System (ADS)

Asy'ari, Hasyim; Sarjito, Prasetio, Septian Heri

2017-04-01

The aim of the research work describe in this paper was to design and optimize a permanent magnet linear generator for renewable energy power plants. It is cover of first stage of designing stator and rotor permanent magnet linear generator. Stator design involves determining dimensions, number of slots, diameter of wire, and the number of winding in each slot. The design of the rotor includes rotor manufacture of PVC pipe material, 10 pieces of permanent magnet type ferrite 271 mikroweber, and resin. The second stage was to assemble the stator and rotor that has been done in the first stage to be a permanent magnet linear generator. The third stage was to install a permanent magnet linear generator with induction motors. Further stage was to test performance of a permanent magnet linear generator by utilizing of induction motor as a prime mover experimentally. In this study, permanent magnet linear generator with a rotor consists of five pairs of permanent magnets. The stator consists of 6 slots of the stator frame, each slot mounted stator coil of 200, 300, 400, 500, and 800 windings, and dimensions of wire used was 0.4 mm. The stator frame was made from acrylic. Results of the experiment that, permanent magnet linear generator when no load was able to generate a DC voltage of 14.5 volts at 300 rpm, and at the output of the linear generator when it is connected to the DC fan as a load only generated of 6.7 volts. It concludes that permanent magnet linear generator output can be used as an input device hybrid system. Data obtained from this experiment in laboratory scale can be developed in a larger scale by varying the type of magnet being used, the number of windings, and the speed used to generate more power.

Microfluidic active mixers employing ultra-high aspect-ratio rare-earth magnetic nano-composite polymer artificial cilia

NASA Astrophysics Data System (ADS)

Rahbar, Mona; Shannon, Lesley; Gray, Bonnie L.

2014-02-01

We present a new micromixer based on highly magnetic, flexible, high aspect-ratio, artificial cilia that are fabricated as individual micromixer elements or in arrays for improved mixing performance. These new cilia enable high efficiency, fast mixing in a microchamber, and are controlled by small electromagnetic fields. The artificial cilia are fabricated using a new micromolding process for nano-composite polymers. Cilia fibers with aspect-ratios as high as 8:0.13 demonstrate the fabrication technique's capability in creating ultra-high aspect-ratio microstructures. Cilia, which are realized in polydimethylsiloxane doped with rare-earth magnetic powder, are magnetized to produce permanent magnetic structures with bidirectional deflection capabilities, making them highly suitable as mixers controlled by electromagnetic fields. Due to the high magnetization level of the polarized nano-composite polymer, we are able to use miniature electromagnets providing relatively small magnetic fields of 1.1 to 7 mT to actuate the cilia microstructures over a very wide motion range. Mixing performances of a single cilium, as well as different arrays of multiple cilia ranging from 2 to 8 per reaction chamber, are characterized and compared with passive diffusion mixing performance. The mixer cilia are actuated at different amplitudes and frequencies to optimize mixing performance. We demonstrate that more than 85% of the total volume of the reaction chamber is fully mixed after 3.5 min using a single cilium mixer at 7 mT compared with only 20% of the total volume mixed with passive diffusion. The time to achieve over 85% mixing is further reduced to 70 s using an array of eight cilia microstructures. The novel microfabrication technique and use of rare-earth permanently-magnetizable nano-composite polymers in mixer applications has not been reported elsewhere by other researchers. We further demonstrate improved mixing over other cilia micromixers as enabled by the high aspect-ratio, high flexibility, and magnetic properties of our cilia micromixer elements.

Maximizing the Performance and Job-Related Behaviors of Contract and Permanent IT Workers

ERIC Educational Resources Information Center

Pai, Tanusree

2010-01-01

As the use of contracting for Information Technology (IT) services steadily increases, IT managers are challenged with reconciling the need for flexibility achieved through the use of contract workers, with the need to understand the factors that maximize the performance and behaviors of contract and permanent IT workers. While several research…

Vertebral artery injuries in cervical spine surgery.

PubMed

Lunardini, David J; Eskander, Mark S; Even, Jesse L; Dunlap, James T; Chen, Antonia F; Lee, Joon Y; Ward, Timothy W; Kang, James D; Donaldson, William F

2014-08-01

Vertebral artery injuries (VAIs) are rare but serious complications of cervical spine surgery, with the potential to cause catastrophic bleeding, permanent neurologic impairment, and even death. The present literature regarding incidence of this complication largely comprises a single surgeon or small multicenter case series. We sought to gather a large sample of high-volume surgeons to adequately characterize the incidence and risk factors for VAI, management strategies used, and patient outcomes after VAI. The study was constructed as a cross-sectional study comprising all cervical spine patients operated on by the members of the international Cervical Spine Research Society (CSRS). All patients who have undergone cervical spine surgery by a current member of CSRS as of the spring of 2012. For each surgeon surveyed, we collected self-reported measures to include the number of cervical cases performed in the surgeon's career, the number of VAIs encountered, the stage of the case during which the injury occurred, the management strategies used, and the overall patient outcome after injury. An anonymous 10-question web-based survey was distributed to the members of the CSRS. Statistical analysis was performed using Student t tests for numerical outcomes and chi-squared analysis for categorical variables. One hundred forty-one CSRS members (of 195 total, 72%) responded to the survey, accounting for a total of 163,324 cervical spine surgeries performed. The overall incidence of VAI was 0.07% (111/163,324). Posterior instrumentation of the upper cervical spine (32.4%), anterior corpectomy (23.4%), and posterior exposure of the cervical spine (11.7%) were the most common stages of the case to result in an injury to the vertebral artery. Discectomy (9%) and anterior exposure of the spine (7.2%) were also common time points for an arterial injury. One-fifth (22/111) of all VAI involved an anomalous course of the vertebral artery. The most common management of VAI was by direct tamponade. The outcomes of VAIs included no permanent sequelae in 90% of patients, permanent neurologic sequelae in 5.5%, and death in 4.5%. Surgeons at academic and private centers had nearly identical rates of VAIs. However, surgeons who had performed 300 or fewer cervical spine surgeries in their career had a VAI incidence of 0.33% compared with 0.06% in those with greater than 300 lifetime cases (p=.028). The overall incidence of VAI during cervical spine surgery reported from this survey was 0.07%. Less experienced surgeons had a higher rate of VAI compared with their more experienced peers. The results of VAI are highly variable, resulting in no permanent harm most of the time; however, permanent neurologic injury or death occur in 10% of cases. Copyright © 2014 Elsevier Inc. All rights reserved.

Survival of atraumatic restorative treatment (ART) sealants and restorations: a meta-analysis.

PubMed

de Amorim, Rodrigo G; Leal, Soraya C; Frencken, Jo E

2012-04-01

The purpose of this study is to perform a systematic investigation plus meta-analysis into survival of atraumatic restorative treatment (ART) sealants and restorations using high-viscosity glass ionomers and to compare the results with those from the 2005 ART meta-analysis. Until February 2010, four databases were searched. Two hundred four publications were found, and 66 reported on ART restorations or sealant survival. Based on five exclusion criteria, two independent reviewers selected the 29 publications that accounted for the meta-analysis. Confidence intervals (CI) and or standard errors were calculated and the heterogeneity variance of the survival rates was estimated. Location (school/clinic) was an independent variable. The survival rates of single-surface and multiple-surface ART restorations in primary teeth over the first 2 years were 93% (CI, 91-94%) and 62% (CI, 51-73%), respectively; for single-surface ART restorations in permanent teeth over the first 3 and 5 years it was 85% (CI, 77-91%) and 80% (CI, 76-83%), respectively and for multiple-surface ART restorations in permanent teeth over 1 year it was 86% (CI, 59-98%). The mean annual dentine lesion incidence rate, in pits and fissures previously sealed using ART, over the first 3 years was 1%. No location effect and no differences between the 2005 and 2010 survival rates of ART restorations and sealants were observed. The short-term survival rates of single-surface ART restorations in primary and permanent teeth, and the caries-preventive effect of ART sealants were high. ART can safely be used in single-surface cavities in both primary and permanent teeth. ART sealants have a high caries preventive effect.

Levitation or suspension: Which one is better for the heavy-load HTS maglev transportation

NASA Astrophysics Data System (ADS)

Liu, Wei; Kang, Dong; Yang, X. F.; Wang, Fei; Peng, G. H.; Zheng, Jun; Ma, G. T.; Wang, J. S.

2015-09-01

Because of the limitation of permanent magnet (PM), the efficient of bulk high-Tc superconductor (HTSC) in a high-Tc superconducting (HTS) maglev system is not very high. It is better to magnetize the bulk HTSC with a high trapped field to increase the force density. The different application type of magnetized bulk HTSC in a maglev system, namely, levitation or suspension type, will bring quite different operation performance. This paper discusses the influence of application type on operation performance of magnetized bulk HTSC by experiments and simulations. From the discussion, it can be found which application type is better for the heavy-load HTS maglev system.

Voxel-based statistical analysis of cerebral glucose metabolism in patients with permanent vegetative state after acquired brain injury.

PubMed

Kim, Yong Wook; Kim, Hyoung Seop; An, Young-Sil; Im, Sang Hee

2010-10-01

Permanent vegetative state is defined as the impaired level of consciousness longer than 12 months after traumatic causes and 3 months after non-traumatic causes of brain injury. Although many studies assessed the cerebral metabolism in patients with acute and persistent vegetative state after brain injury, few studies investigated the cerebral metabolism in patients with permanent vegetative state. In this study, we performed the voxel-based analysis of cerebral glucose metabolism and investigated the relationship between regional cerebral glucose metabolism and the severity of impaired consciousness in patients with permanent vegetative state after acquired brain injury. We compared the regional cerebral glucose metabolism as demonstrated by F-18 fluorodeoxyglucose positron emission tomography from 12 patients with permanent vegetative state after acquired brain injury with those from 12 control subjects. Additionally, covariance analysis was performed to identify regions where decreased changes in regional cerebral glucose metabolism significantly correlated with a decrease of level of consciousness measured by JFK-coma recovery scale. Statistical analysis was performed using statistical parametric mapping. Compared with controls, patients with permanent vegetative state demonstrated decreased cerebral glucose metabolism in the left precuneus, both posterior cingulate cortices, the left superior parietal lobule (P(corrected) < 0.001), and increased cerebral glucose metabolism in the both cerebellum and the right supramarginal cortices (P(corrected) < 0.001). In the covariance analysis, a decrease in the level of consciousness was significantly correlated with decreased cerebral glucose metabolism in the both posterior cingulate cortices (P(uncorrected) < 0.005). Our findings suggest that the posteromedial parietal cortex, which are part of neural network for consciousness, may be relevant structure for pathophysiological mechanism in patients with permanent vegetative state after acquired brain injury.

Enhanced Energy Density in Permanent Magnets using Controlled High Magnetic Field during Processing

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

Rios, Orlando; Carter, Bill; Constantinides, Steve

This ORNL Manufacturing Demonstraction Facility (MDF) technical collaboration focused on the use of high magnetic field processing (>2Tesla) using energy efficient large bore superconducting magnet technology and high frequency electromagnetics to improve magnet performance and reduce the energy budget associated with Alnico thermal processing. Alnico, alloys containing Al, Ni, Co and Fe, represent a class of functional nanostructured alloys, and show the greatest potential for supplementing or replacing commercial Nd-based rare-earth alloy magnets.

Porous Structure Design of Polymeric Membranes for Gas Separation

DOE PAGES

Zhang, Jinshui; Schott, Jennifer Ann; Mahurin, Shannon Mark; ...

2017-04-04

High-performance polymeric membranes for gas separation are of interest for molecular-level separations in industrial-scale chemical, energy and environmental processes. To overcome the inherent trade-off relationship between permeability and selectivity, the creation of permanent microporosity in polymeric matrices is highly desirable because the porous structures can provide a high fractional free volume to facilitate gas transport through the dense layer. In this feature article, recent developments in the formation of porous polymeric membranes and potential strategies for pore structure design are reviewed.

Reflexiones Sobre la Capacitacion de Docentes (Reflections on In-Service Teacher Training).

ERIC Educational Resources Information Center

Valle, Victor M.

Everyone concerned with educational systems performance agrees that the improvement of teaching qualities is a high priority in any educational effort. Teachers are assigned the role of change agents and are presented with new challenges, e.g., to make education global and permanent, flexible enough to serve in any environment (in or out of the…

Special-Purpose High-Torque Permanent-Magnet Motors

NASA Technical Reports Server (NTRS)

Doane, George B., III

1995-01-01

Permanent-magnet brushless motors that must provide high commanded torques and satisfy unusual heat-removal requirement are developed. Intended for use as thrust-vector-control actuators in large rocket engines. Techniques and concepts used to design improved motors for special terrestrial applications. Conceptual motor design calls for use of rotor containing latest high-energy-product rare-earth permanent magnets so that motor produces required torque while drawing smallest possible currents from power supply. Torque generated by electromagnetic interaction between stator and permanent magnets in rotor when associated electronic circuits applied appropriately temporally and spatially phased currents to stator windings. Phase relationships needed to produce commanded torque computed in response to torque command and to electronically sensed angular position of rotor relative to stator.

Long-term effects of clearcutting on tree species composition in an oak-hickory forest

Treesearch

Jessica A. Yeagle; John W. Groninger

2006-01-01

In 1973, a silvicultural clearcut, with and without a post-harvest herbicide treatment, was performed on an upland oak-hickory forest in southern Illinois. Prior to harvest, permanent plots were established, and a survey was conducted to determine stand structure and composition. In 2003, a post-harvest survey was performed using the permanent plots. Relative density...

Pure-type superconducting permanent-magnet undulator.

PubMed

Tanaka, Takashi; Tsuru, Rieko; Kitamura, Hideo

2005-07-01

A novel synchrotron radiation source is proposed that utilizes bulk-type high-temperature superconductors (HTSCs) as permanent magnets (PMs) by in situ magnetization. Arrays of HTSC blocks magnetized by external magnetic fields are placed below and above the electron path instead of conventional PMs, generating a periodic magnetic field with an offset. Two methods are presented to magnetize the HTSCs and eliminate the field offset, enabling the HTSC arrays to work as a synchrotron radiation source. An analytical formula to calculate the peak field achieved in a device based on this scheme is derived in a two-dimensional form for comparison with synchrotron radiation sources using conventional PMs. Experiments were performed to demonstrate the principle of the proposed scheme and the results have been found to be very promising.

A study of the suitability of ferrite for use in low-field insertion devices

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

Johnson, K.; Hassenzahl, W.V.

1995-02-01

Most insertion devices built to date use rare-earth permanent-magnet materials, which have a high remanent field and are more expensive than many other permanent-magnet materials. Low-field insertion devices could use less-expensive, lower performance magnetic materials if they had suitable magnetic characteristics. These materials must be resistant to demagnetization during construction and operation of the insertion device, have uniform magnetization, possess low minor-axis magnetic moments, and have small minor field components on the surfaces. This paper describes an investigation to determine if ferrite possesses magnetic qualities suitable for insertion device applications. The type of ferrite investigated, MMPA Ceramic 8 from Stackpolemore » Inc., was found to be acceptable for insertion device applications.« less

Laser damage helps the eavesdropper in quantum cryptography.

PubMed

Bugge, Audun Nystad; Sauge, Sebastien; Ghazali, Aina Mardhiyah M; Skaar, Johannes; Lydersen, Lars; Makarov, Vadim

2014-02-21

We propose a class of attacks on quantum key distribution (QKD) systems where an eavesdropper actively engineers new loopholes by using damaging laser illumination to permanently change properties of system components. This can turn a perfect QKD system into a completely insecure system. A proof-of-principle experiment performed on an avalanche photodiode-based detector shows that laser damage can be used to create loopholes. After ∼1  W illumination, the detectors' dark count rate reduces 2-5 times, permanently improving single-photon counting performance. After ∼1.5  W, the detectors switch permanently into the linear photodetection mode and become completely insecure for QKD applications.

The Mid-Term Efficacy and Safety of a Permanent Nitinol IVC Filter (TrapEase)

PubMed Central

Liu, Wei Chiang; Choo, Sung Wook; Kim, Dong-Ik; Kim, Young Wook; Kim, Duk-Kyung; Shin, Sung Wook; Park, Kwang Bo; Jeon, Yong Hwan; Choo, In-Wook

2005-01-01

Objective 1) To evaluate the mid-term efficacy and safety of a permanent nitinol inferior vena cava (IVC) filter; 2) to evaluate filter effectiveness, filter stability and caval occlusion. Materials and Methods A prospective evaluation of the TrapEase IVC filter was performed on 42 patients (eight men, 34 women) ranging in age from 22 to 78 years (mean age 66 years). All patients were ill with a high risk of pulmonary embolism (PE). Indications for filter placement were: 1) deep vein thrombosis with recurrent thromboembolism; 2) and/or free-floating thrombus with contraindication to anticoagulation; and 3) complications in achieving adequate anticoagulation. Follow-up evaluations (mean: 15.4 months, range: 2 to 28 months) were performed at 6- and 12-month intervals after the procedure and included clinical histories, chart reviews, plain film, Doppler ultrasounds, and contrasted abdominal CT scans. Results In follow-up evaluations, the data analysis revealed no cases of symptomatic PE. There were no cases of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study, there was one case of filter thrombosis; early symptomatic thrombosis that was successfully treated in the hospital. Of the 42 subjects, eight died. These deaths were not related to the filter device or the implantation procedure, but to the underlying disease. Conclusion This study demonstrates that the TrapEase permanent IVC filter is a safe and an effective device with low complication rates and is best used in patients with thromboembolic disease with a high risk of PE. PMID:15968150

A portable high power microwave source with permanent magnets

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

Li, Wei; Zhang, Jun; Li, Zhi-qiang

A high power microwave source with permanent magnets is proposed in this paper. The source has the length 330 mm, maximum diameter 350 mm, and total weight 50 kg, including 25 kg of permanent magnets. 1 GW of microwave power with Gaussian radiation pattern and 24% of microwave power generation efficiency in a pulse duration of 75 ns are obtained in the experiment. Operating frequency of the source is 2.32 GHz. Such a small size, light weight, and highly stable in operation source will be used in portable repetitive high power microwave generation systems.

Design and Performance Improvement of AC Machines Sharing a Common Stator

NASA Astrophysics Data System (ADS)

Guo, Lusu

With the increasing demand on electric motors in various industrial applications, especially electric powered vehicles (electric cars, more electric aircrafts and future electric ships and submarines), both synchronous reluctance machines (SynRMs) and interior permanent magnet (IPM) machines are recognized as good candidates for high performance variable speed applications. Developing a single stator design which can be used for both SynRM and IPM motors is a good way to reduce manufacturing and maintenance cost. SynRM can be used as a low cost solution for many electric driving applications and IPM machines can be used in power density crucial circumstances or work as generators to meet the increasing demand for electrical power on board. In this research, SynRM and IPM machines are designed sharing a common stator structure. The prototype motors are designed with the aid of finite element analysis (FEA). Machine performances with different stator slot and rotor pole numbers are compared by FEA. An 18-slot, 4-pole structure is selected based on the comparison for this prototype design. Sometimes, torque pulsation is the major drawback of permanent magnet synchronous machines. There are several sources of torque pulsations, such as back-EMF distortion, inductance variation and cogging torque due to presence of permanent magnets. To reduce torque pulsations in permanent magnet machines, all the efforts can be classified into two categories: one is from the design stage, the structure of permanent magnet machines can be optimized with the aid of finite element analysis. The other category of reducing torque pulsation is after the permanent magnet machine has been manufactured or the machine structure cannot be changed because of other reasons. The currents fed into the permanent magnet machine can be controlled to follow a certain profile which will make the machine generate a smoother torque waveform. Torque pulsation reduction methods in both categories will be discussed in this dissertation. In the design stage, an optimization method based on orthogonal experimental design will be introduced. Besides, a universal current profiling technique is proposed to minimize the torque pulsation along with the stator copper losses in modular interior permanent magnet motors. Instead of sinusoidal current waveforms, this algorithm will calculate the proper currents which can minimize the torque pulsation. Finite element analysis and Matlab programing will be used to develop this optimal current profiling algorithm. Permanent magnet machines are becoming more attractive in some modern traction applications, such as traction motors and generators for an electrified vehicle. The operating speed or the load condition in these applications may be changing all the time. Compared to electric machines used to operate at a constant speed and constant load, better control performance is required. In this dissertation, a novel model reference adaptive control (MRAC) used on five-phase interior permanent magnet motor drives is presented. The primary controller is designed based on artificial neural network (ANN) to simulate the nonlinear characteristics of the system without knowledge of accurate motor model or parameters. The proposed motor drive decouples the torque and flux components of five-phase IPM motors by applying a multiple reference frame transformation. Therefore, the motor can be easily driven below the rated speed with the maximum torque per ampere (MTPA) operation or above the rated speed with the flux weakening operation. The ANN based primary controller consists of a radial basis function (RBF) network which is trained on-line to adapt system uncertainties. The complete IPM motor drive is simulated in Matlab/Simulink environment and implemented experimentally utilizing dSPACE DS1104 DSP board on a five-phase prototype IPM motor. The proposed model reference adaptive control method has been applied on the commons stator SynRM and IPM machine as well.

Topology optimized permanent magnet systems

NASA Astrophysics Data System (ADS)

Bjørk, R.; Bahl, C. R. H.; Insinga, A. R.

2017-09-01

Topology optimization of permanent magnet systems consisting of permanent magnets, high permeability iron and air is presented. An implementation of topology optimization for magnetostatics is discussed and three examples are considered. The Halbach cylinder is topology optimized with iron and an increase of 15% in magnetic efficiency is shown. A topology optimized structure to concentrate a homogeneous field is shown to increase the magnitude of the field by 111%. Finally, a permanent magnet with alternating high and low field regions is topology optimized and a Λcool figure of merit of 0.472 is reached, which is an increase of 100% compared to a previous optimized design.

Long-term outcomes in younger men following permanent prostate brachytherapy.

PubMed

Shapiro, Edan Y; Rais-Bahrami, Soroush; Morgenstern, Carol; Napolitano, Barbara; Richstone, Lee; Potters, Louis

2009-04-01

We reviewed the long-term outcomes in men undergoing permanent prostate brachytherapy with a focus on those presenting before age 60 years. Between 1992 and 2005 a total of 2,119 patients with clinical stage T1-T2, N0, M0 prostate cancer treated with permanent prostate brachytherapy were included in this study. Treatment regimens consisted of permanent prostate brachytherapy with or without hormone therapy, permanent prostate brachytherapy with external beam radiotherapy, or all 3 modalities. Biochemical recurrence was defined using the Phoenix definition. Multivariate analysis was performed to determine if age and/or other clinicopathological features were associated with disease progression. The Kaplan-Meier method was used to calculate rates of freedom from progression with the log rank test to compare patients younger than 60 vs 60 years or older. Median followup was 56.1 months. In the study population 237 patients were younger than 60 years at diagnosis (11%). The 5 and 10-year freedom from progression rates were 90.1% and 85.6%, respectively, for the entire population. Multivariate analysis demonstrated that prostate specific antigen (p <0.01), biopsy Gleason score (p <0.0001) and year of treatment (p <0.001) were associated with freedom from progression while age (p = 0.95) and clinical stage (p = 0.11) were not. There was no significant difference in freedom from progression between men younger than 60, or 60 years or older (log rank p = 0.46). In the younger cohort the 10-year freedom from progression for patients presenting with low, intermediate and high risk disease was 91.3%, 80.0% and 70.2% compared to 91.8%, 83.4% and 72.1%, respectively, for men 60 years or older. Our long-term results confirm favorable outcomes after permanent prostate brachytherapy in men younger than 60 years. Outcomes are impacted by disease related risk factors but not by age or clinical stage. Definitive treatment options for younger men with clinically localized prostate cancer should include permanent prostate brachytherapy.

Scalable NMR spectroscopy with semiconductor chips

PubMed Central

Ha, Dongwan; Paulsen, Jeffrey; Sun, Nan; Song, Yi-Qiao; Ham, Donhee

2014-01-01

State-of-the-art NMR spectrometers using superconducting magnets have enabled, with their ultrafine spectral resolution, the determination of the structure of large molecules such as proteins, which is one of the most profound applications of modern NMR spectroscopy. Many chemical and biotechnological applications, however, involve only small-to-medium size molecules, for which the ultrafine resolution of the bulky, expensive, and high-maintenance NMR spectrometers is not required. For these applications, there is a critical need for portable, affordable, and low-maintenance NMR spectrometers to enable in-field, on-demand, or online applications (e.g., quality control, chemical reaction monitoring) and co-use of NMR with other analytical methods (e.g., chromatography, electrophoresis). As a critical step toward NMR spectrometer miniaturization, small permanent magnets with high field homogeneity have been developed. In contrast, NMR spectrometer electronics capable of modern multidimensional spectroscopy have thus far remained bulky. Complementing the magnet miniaturization, here we integrate the NMR spectrometer electronics into 4-mm2 silicon chips. Furthermore, we perform various multidimensional NMR spectroscopies by operating these spectrometer electronics chips together with a compact permanent magnet. This combination of the spectrometer-electronics-on-a-chip with a permanent magnet represents a useful step toward miniaturization of the overall NMR spectrometer into a portable platform. PMID:25092330

21st Century HVAC System for Future Naval Surface Combatants - Concept Development Report

DTIC Science & Technology

2007-09-01

application of permanent magnet motors to ventilation fans3. The study emphasized reducing the motor size, incorporating variable speed operation to reduce...Incorporation of permanent magnet motors and variable speed is also feasible. Permanent magnet motor technology is ideally suited for variable...family incorporates high speed permanent magnet motors and further fan blade design improvements. The fan diameters will be reduced, substantially, at the

High School Voter Registration.

ERIC Educational Resources Information Center

Institute for Political/Legal Education, Sewell, NJ.

Methods for conducting peer voter registration of high school students cover establishing a permanent voter registration committee and identifying and registering eligible students. The permanent voter registration committee, made up of student body representatives, class representatives, and selected teachers, guarantees comprehensive…

Procurement specification color graphic camera system

NASA Technical Reports Server (NTRS)

Prow, G. E.

1980-01-01

The performance and design requirements for a Color Graphic Camera System are presented. The system is a functional part of the Earth Observation Department Laboratory System (EODLS) and will be interfaced with Image Analysis Stations. It will convert the output of a raster scan computer color terminal into permanent, high resolution photographic prints and transparencies. Images usually displayed will be remotely sensed LANDSAT imager scenes.

Exploring the Attractiveness of a Norwegian Rural Higher Education Institution Using Importance-Performance Analysis

ERIC Educational Resources Information Center

Hanssen, Thor-Erik Sandberg; Mathisen, Terje Andreas

2018-01-01

High school graduates in rural counties often move to urban areas to study at higher education institutions (HEIs). Because graduates from HEIs often settle in regions in which they graduate, the result is a permanent out-migration of young talent from rural areas. This study adds to the body of literature on student choice by addressing measures…

Options for Affordable Fission Surface Power Systems

NASA Technical Reports Server (NTRS)

Houts, Mike; Gaddis, Steve; Porter, Ron; VanDyke, Melissa; Martin Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise

2006-01-01

Fission surface power systems could provide abundant power anywhere on free surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized; however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems.

Awake Craniotomy: First-Year Experiences and Patient Perception.

PubMed

Joswig, Holger; Bratelj, Denis; Brunner, Thomas; Jacomet, Alfred; Hildebrandt, Gerhard; Surbeck, Werner

2016-06-01

Awake craniotomy for brain lesions in or near eloquent brain regions enables neurosurgeons to assess neurologic functions of patients intraoperatively, reducing the risk of permanent neurologic deficits and increasing the extent of resection. A retrospective review was performed of a consecutive series of patients with awake craniotomies in the first year of their introduction to our tertiary non-university-affiliated neurosurgery department. Operation time, complications, and neurologic outcome were assessed, and patient perception of awake craniotomy was surveyed using a mailed questionnaire. There were 24 awake craniotomies performed in 22 patients for low-grade/high-grade gliomas, cavernomas, and metastases (average 2 cases per month). Mean operation time was 205 minutes. Failure of awake craniotomy because of intraoperative seizures with subsequent postictal impaired testing or limited cooperation occurred in 2 patients. Transient neurologic deficits occurred in 29% of patients; 1 patient sustained a permanent neurologic deficit. Of the 18 patients (82%) who returned the questionnaire, only 2 patients recalled significant fear during surgery. Introducing awake craniotomy to a tertiary non-university-affiliated neurosurgery department is feasible and resulted in reasonable operation times and complication rates and high patient satisfaction. Copyright © 2016 Elsevier Inc. All rights reserved.

Testing the quality of images for permanent magnet desktop MRI systems using specially designed phantoms.

PubMed

Qiu, Jianfeng; Wang, Guozhu; Min, Jiao; Wang, Xiaoyan; Wang, Pengcheng

2013-12-21

Our aim was to measure the performance of desktop magnetic resonance imaging (MRI) systems using specially designed phantoms, by testing imaging parameters and analysing the imaging quality. We designed multifunction phantoms with diameters of 18 and 60 mm for desktop MRI scanners in accordance with the American Association of Physicists in Medicine (AAPM) report no. 28. We scanned the phantoms with three permanent magnet 0.5 T desktop MRI systems, measured the MRI image parameters, and analysed imaging quality by comparing the data with the AAPM criteria and Chinese national standards. Image parameters included: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, signal-to-noise ratio (SNR), and image uniformity. The image parameters of three desktop MRI machines could be measured using our specially designed phantoms, and most parameters were in line with MRI quality control criterion, including: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, image uniformity and slice position accuracy. However, SNR was significantly lower than in some references. The imaging test and quality control are necessary for desktop MRI systems, and should be performed with the applicable phantom and corresponding standards.

Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture

PubMed Central

Yang, Chao; Xie, Jun; Zhou, Xiaojun; Liu, Quantao; Pang, Ling

2018-01-01

Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO2 content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture. PMID:29702579

Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture.

PubMed

Yang, Chao; Xie, Jun; Zhou, Xiaojun; Liu, Quantao; Pang, Ling

2018-04-27

Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO₂ content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture.

Cost Performance Estimating Relationships for Hybrid Electric Vehicle Components

DTIC Science & Technology

2003-07-31

Permanent magnet motors are more likely to be used as generators, while AC induction motors are more efficiently used as motors. Inverters/controllers can...than permanent magnet motors . Switched Reluctance motors are also used on hybrid electric vehicles, but are not used as widely as either AC...induction or permanent magnet motors , and are not analyzed here. Methodology The motor estimates are based on power, with kilowatts being the unit of

Partners of patients having a permanent colostomy should also receive attention from the healthcare team.

PubMed

Silva, A L; Monteiro, P S; Sousa, J B; Vianna, A L; Oliveira, P G

2014-12-01

This study was carried out to determine how the partners of patients with a permanent colostomy perceive everyday life, particularly its sexual aspects. Data were collected prospectively from October 2011 to May 2012 using a three-part questionnaire to obtain demographic, social and sexual information. Both multiple-choice and yes/no questions were used. One hundred and eight questionnaires were given to 36 partners of patients with a permanent colostomy (the ostomy group) and to 72 partners of normal individuals matched for age, sex and social class. The sexual performance of the spouse was significantly better in the control group (P = 0.004), sexual performance of the partner was also better in the control group (P = 0.023) and reduced frequency of sexual activity was higher in the ostomy group (P = 0.042). There was, however, no significant difference in sexual interest between the two groups (P = 0.507). The study demonstrated that about half of the partners of patients with a permanent colostomy experienced dissatisfaction with their spouse's performance, with a reduction in sexual interest and frequency of intercourse compared with the control group. Healthcare professionals should pay more attention to the partner of patients having a permanent colostomy. © 2014 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.

Environmental determinants of the spatial distribution of Alaria alata in Hungary.

PubMed

Széll, Z; Tolnai, Z; Sréter, T

2013-11-15

Alaria alata is a potential zoonotic parasite, which is widely distributed in Eurasia. To assess the risk of human infection, it is important to know the spatial distribution pattern of the parasite and factors influencing this pattern. To investigate these relationships, 1612 red fox (Vulpes vulpes) carcasses were randomly collected from the whole Hungarian territory, and the intestines were examined by sedimentation and counting technique. The spatial distribution of the parasite was highly clumped. The topographic positions where the foxes had been shot and the intensity of infections were recorded in geographic information system database. Digitized home ranges of infected and uninfected foxes were analysed on the background of geographic vector data of altitude, land cover types, permanent waters, mean annual temperature, annual precipitation and soil permeability. Multiple regression analysis was performed with environmental parameter values and A. alata scores. Based on the statistical analysis, lack of permanent waters, mean annual temperature, annual precipitation and soil permeability were the major determinants of the spatial distribution of A. alata. It can be explained by the use of biotopes by the intermediate hosts. The lack of permanent waters results in the use of temporary waters by the second intermediate hosts, frogs. The higher temperature, the lower precipitation and the higher soil permeability lead to earlier desiccation of temporary waters, and tadpoles and frogs infected with mesocercariae can be more easily predated by the final hosts (e.g., red foxes). Moreover, temporary waters are more easily contaminated with the faeces of the final hosts containing eggs than permanent waters. Therefore, high infection rate with A. alata can be expected mainly in lowland areas, where the hydrogeography of permanent waters is less complex, the precipitation is lower, the mean temperature and the soil permeability are higher than in highland areas. Copyright © 2013 Elsevier B.V. All rights reserved.

Over two hundred million injuries to anterior teeth attributable to large overjet: a meta-analysis.

PubMed

Petti, Stefano

2015-02-01

The association between large overjet and traumatic dental injuries (TDIs) to anterior teeth is documented. However, observational studies are discrepant and generalizability (i.e. external validity) of meta-analyses is limited. Therefore, this meta-analysis sought to reconcile such discrepancies seeking to provide reliable risk estimates which could be generalizable at global level. Literature search (years 1990-2014) was performed (Scopus, GOOGLE Scholar, Medline). Selected primary studies were divided into subsets: 'primary teeth, overjet threshold 3-4 mm' (Primary3); 'permanent teeth, overjet threshold 3-4 mm' (Permanent3); 'permanent teeth, overjet threshold 6 ± 1 mm' (Permanent6). The adjusted odds ratios (ORs) were extracted. To obtain the highest level of reliability (i.e. internal validity), the pooled OR estimates were assessed accounting for between-study heterogeneity, publication bias and confounding. Result robustness was investigated with sensitivity and subgroup analyses. Fifty-four primary studies from Africa, America, Asia and Europe were included. The sampled individuals were children, adolescents and adults. Overall, there were >10 000 patients with TDI. The pooled OR estimates resulted 2.31 (95% confidence interval - 95CI, 1.01-5.27), 2.01 (95CI, 1.39-2.91) and 2.24 (95CI, 1.56-3.21) for Primary3, Permanent3 and Permant6, respectively. Sensitivity and subgroup analyses corroborated these estimates. Reliability and generalizability of pooled ORs were high enough and made it possible to assess that the fraction of global TDIs attributable to large overjet is 21.8% (95CI, 9.7-34.5%) and that large overjet is co-responsible for 235 008 000 global TDI cases (95CI, 104,760,000-372,168,000). This high global burden of TDI suggests that preventive measures must be implemented in patients with large overjet. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Relationship between pseudoaneurysm formation and biloma after successful transarterial embolization for severe hepatic injury: permanent embolization using stainless steel coils prevents pseudoaneurysm formation.

PubMed

Hagiwara, Akiyoshi; Tarui, Takehiko; Murata, Atsuo; Matsuda, Takeaki; Yamaguti, Yoshihiro; Shimazaki, Shuji

2005-07-01

The purpose of this study was to determine the association between bilomas and pseudoaneurysm complications after severe hepatic injury. Angiography was performed in patients with American Association for the Surgery of Trauma grade > or = III hepatic injury on contrast-enhanced computed tomographic scanning. When contrast extravasation was observed, transarterial embolization (TAE) was performed. After TAE, technetium-99m pyridoxyl-5-methyl-tryptophan cholescintigraphy was performed to detect the coexistence of bilomas. Follow-up angiography was performed when a biloma was detected. Eighty consecutive patients underwent angiography; after angiography, five patients died. The remaining 75 patients who underwent cholescintigraphy were included in this study. All 11 patients who had bilomas had angiographic evidence of contrast extravasation. The biloma frequency was higher in patients with grades IV and V injuries than in those with grade III injury (p = 0.024). Follow-up angiography revealed pseudoaneurysms in 7 of these 11 patients. All six patients in whom only gelatin sponge pledget injection was used to embolize had pseudoaneurysms. Among them, two patients had computed tomographic evidence of massive intra-abdominal fluid collection. In contrast, only one of five patients who received the combination of gelatin sponge pledget injection and stainless steel coils to permanently embolize injured arteries had a pseudoaneurysm. In this patient, the pseudoaneurysm was found in the peripheral part of the collateral vessels. All patients with pseudoaneurysms underwent repeat TAE and were discharged from the hospital uneventfully. In patients with high-grade hepatic injury and arterial bleeding who developed biloma, use of a gelatin sponge, an absorbable embolic material, is associated with a risk of pseudoaneurysm formation. Permanent arterial embolization using stainless steel coils is indicated to decrease this risk.

Damage in Monolithic Thin-Film Photovoltaic Modules Due to Partial Shade

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

Silverman, Timothy J.; Mansfield, Lorelle; Repins, Ingrid

2016-09-01

The typical configuration of monolithic thin-film photovoltaic modules makes it possible for partial shade to place one or more cells in such a module in reverse bias. Reverse bias operation leads to high voltage, current density, and power density conditions, which can act as driving forces for failure. We showed that a brief outdoor shadow event can cause a 7% permanent loss in power. We applied an indoor partial shade durability test that moves beyond the standard hot spot endurance test by using more realistic mask and bias conditions and by carefully quantifying the permanent change in performance due tomore » the stress. With the addition of a pass criterion based on change in maximum power, this procedure will soon be proposed as a part of the module-type qualification test. All six commercial copper indium gallium diselenide and cadmium telluride modules we tested experienced permanent damage due to the indoor partial shade test, ranging from 4% to 14% loss in maximum power. We conclude by summarizing ways to mitigate partial shade stress at the cell, module, and system levels.« less

Running Performance of a Pinning-Type Superconducting Magnetic Levitation Guide

NASA Astrophysics Data System (ADS)

Okano, M.; Iwamoto, T.; Furuse, M.; Fuchino, S.; Ishii, I.

2006-06-01

A pinning-type superconducting magnetic levitation guide with bulk high-Tc superconductors was studied for use as a goods transportation system, an energy storage system, etc. A superconducting magnetic levitation running test apparatus with a circular track of ca. 38 m length, 12 m diameter, which comprises the magnetic rail constituted by Nd-B-Fe rare-earth permanent magnets and steel plates, was manufactured to examine loss and high-speed performance of the magnetic levitation guide. Running tests were conducted in air. These tests clarify that a vehicle supported by a superconducting magnetic levitation guide runs stably at speeds greater than 42 km/h above the circular track.

Permanent magnet with MgB{sub 2} bulk superconductor

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

Yamamoto, Akiyasu, E-mail: yamamoto@appchem.t.u-tokyo.ac.jp; JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012; Ishihara, Atsushi

2014-07-21

Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB{sub 2}) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB{sub 2} permanent bulkmore » magnet was determined. Because MgB{sub 2} is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB{sub 2} bulks promising for the next generation of Tesla-class permanent-magnet applications.« less

Vasectomy as a reversible form of contraception for select patients.

PubMed

Samplaski, Mary K; Daniel, Ariande; Jarvi, Keith

2014-04-01

To provide an effective form of birth control, men may choose a reversible or permanent form of contraception. Vasectomy is presently offered as a permanent option for male contraception. We have had patients who were interested in vasectomy and reversal as a temporary birth control option. The purpose of this paper is to determine if vasectomy should be offered for selected couples as a temporary form of contraception and under which circumstances. A literature review was conducted to determine the available reversible contraceptive options, risks, failure rates and contraindications to each, and the risks and success rates of vasectomy and vasectomy reversal. Reversible contraceptives include hormonally based methods for women, non-hormonal anatomic barrier devices and spermatocidal agents. Hormone based therapies may be contraindicated in women with cardiovascular disease, hypertension, and some cancers. Non-hormonal contraceptives are generally less effective and may be unacceptable for some couples due to higher failure rates, difficulty of use and lack of acceptance. Both vasectomy and vasectomy reversal are low risk procedures. Reversal may be performed with a high degree of success, particularly with a short obstructive interval (97% patency if performed < 3 years following vasectomy). While vasectomy should be considered a permanent form of sterilization for most couples, there are select couples, unable or unwilling to use other forms of birth control, who would benefit from an informed discussion about using a vasectomy as a reversible form of contraception.

Vicarious absolute radiometric calibration of GF-2 PMS2 sensor using permanent artificial targets in China

NASA Astrophysics Data System (ADS)

Liu, Yaokai; Li, Chuanrong; Ma, Lingling; Wang, Ning; Qian, Yonggang; Tang, Lingli

2016-10-01

GF-2, launched on August 19 2014, is one of the high-resolution land resource observing satellite of the China GF series satellites plan. The radiometric performance evaluation of the onboard optical pan and multispectral (PMS2) sensor of GF-2 satellite is very important for the further application of the data. And, the vicarious absolute radiometric calibration approach is one of the most useful way to monitor the radiometric performance of the onboard optical sensors. In this study, the traditional reflectance-based method is used to vicarious radiometrically calibrate the onboard PMS2 sensor of GF-2 satellite using three black, gray and white reflected permanent artificial targets located in the AOE Baotou site in China. Vicarious field calibration campaign were carried out in the AOE-Baotou calibration site on 22 April 2016. And, the absolute radiometric calibration coefficients were determined with in situ measured atmospheric parameters and surface reflectance of the permanent artificial calibration targets. The predicted TOA radiance of a selected desert area with our determined calibrated coefficients were compared with the official distributed calibration coefficients. Comparison results show a good consistent and the mean relative difference of the multispectral channels is less than 5%. Uncertainty analysis was also carried out and a total uncertainty with 3.87% is determined of the TOA radiance.

Miniature high speed compressor having embedded permanent magnet motor

NASA Technical Reports Server (NTRS)

Zhou, Lei (Inventor); Zheng, Liping (Inventor); Chow, Louis (Inventor); Kapat, Jayanta S. (Inventor); Wu, Thomas X. (Inventor); Kota, Krishna M. (Inventor); Li, Xiaoyi (Inventor); Acharya, Dipjyoti (Inventor)

2011-01-01

A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing supports.

Feasibility of introducing ferromagnetic materials to onboard bulk high-Tc superconductors to enhance the performance of present maglev systems

NASA Astrophysics Data System (ADS)

Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

2013-02-01

Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves.

Reprocessing and Recycling of Highly Cross-Linked Ion-Conducting Networks through Transalkylation Exchanges of C-N Bonds.

PubMed

Obadia, Mona M; Mudraboyina, Bhanu P; Serghei, Anatoli; Montarnal, Damien; Drockenmuller, Eric

2015-05-13

Exploiting exchangeable covalent bonds as dynamic cross-links recently afforded a new class of polymer materials coined as vitrimers. These permanent networks are insoluble and infusible, but the network topology can be reshuffled at high temperatures, thus enabling glasslike plastic deformation and reprocessing without depolymerization. We disclose herein the development of functional and high-value ion-conducting vitrimers that take inspiration from poly(ionic liquid)s. Tunable networks with high ionic content are obtained by the solvent- and catalyst-free polyaddition of an α-azide-ω-alkyne monomer and simultaneous alkylation of the resulting poly(1,2,3-triazole)s with a series of difunctional cross-linking agents. Temperature-induced transalkylation exchanges of C-N bonds between 1,2,3-triazolium cross-links and halide-functionalized dangling chains enable recycling and reprocessing of these highly cross-linked permanent networks. They can also be recycled by depolymerization with specific solvents able to displace the transalkylation equilibrium, and they display a great potential for applications that require solid electrolytes with excellent mechanical performances and facile processing such as supercapacitors, batteries, fuel cells, and separation membranes.

The Onset of Representation and Entry into Stage 6 of Object Permanence Development

ERIC Educational Resources Information Center

Campos, Joseph J.; Ramsay, Douglas S.

1978-01-01

Attempts to determine whether infants' performance in two search tasks is related to their entry into Stage 6 of object permanence development (thereby testing Piaget's claim that only Stage 6 infants possess the capacity for representation). (BD)

Consequences of early extraction of compromised first permanent molar: a systematic review.

PubMed

Saber, Afnan M; Altoukhi, Doua H; Horaib, Mariam F; El-Housseiny, Azza A; Alamoudi, Najlaa M; Sabbagh, Heba J

2018-04-05

The aim of this study was to systematically review the literature to determine the sequelae of early extraction of compromised first permanent molars (FPMs) with regard to the skeletal and dental development of 5- to 15-year-old children. Meta-analysis was conducted when applicable. Our research protocol included a search strategy, inclusion/exclusion criteria, and a data extraction plan. The search engines used were PubMed, Scopus, and Science Direct. Study selection was performed independently by three reviewers. Articles published from 1960 to 2017 were reviewed based on inclusion and exclusion criteria. Meta-analysis was performed to compare space closure between upper and lower arches. Eleven studies fulfilled the inclusion criteria. The consequences were decrease in post extraction space, accelerated development and eruption of second permanents molars (SPMs) and third molars, a decrease in caries and/or fillings on the proximal surfaces of adjacent teeth, lingual tipping and retrusion of incisors, and counter clockwise rotation of the occlusal plane. There were several consequences of early extraction of FPMs, which were related to skeletal and dental development. Our systematic review suggests that comprehensive evaluation of the compromised FPMs should be performed before planning an extraction. The ideal time for FPM extraction is when the SPM is at the early bifurcation stage in order to achieve complete closure of the extraction space by the SPM. Benefits should be weighed over the risks to decrease the risk of unfavorable outcomes as much as possible. However, due to the limited evidence on the outcomes and variables that influence them, high-quality prospective studies are needed.

Etiological evaluation of primary congenital hypothyroidism cases.

PubMed

Bezen, Diğdem; Dilek, Emine; Torun, Neşe; Tütüncüler, Filiz

2017-06-01

Primary congenital hypothyroidism is frequently seen endocrine disorder and one of the preventable cause of mental retardation. Aim of study was to evaluate the frequency of permanent/transient hypothyrodism, and to detect underlying reason to identfy any marker which carries potential to discriminate permanent/transient form. Forty eight cases older than 3 years of age, diagnosed as primary congenital hypothyroidism and started thyroxin therapy in newborn-period, and followed up between January 2007-June 2013 were included in the study. Thyroid hormon levels were evaluated and thyroid ultrasonography was performed in cases who are at the end of their 3 years of age, after 6 weeks of thyroxine free period. Thyroid sintigraphy was performed if serum thyroid-stimulating hormone was high (≥ 5 mIU/mL) and perchlorate discharge test was performed if uptake was normal or increased on sintigraphy. Cases with thyroid-stimulating hormone levels ≥ 5 mIU/mL were defined as permanent primary congenital hypothyroidism group and as transient primary congenital hypothyroidism group with normal thyroid hormones during 6 months. The mean age was 3.8±0.7 years. Mean diagnosis age was 16.6±6.5 days and 14 cases (29.2%) were diagnosed by screening program of Ministry of Health. There were 23 cases (14F, 9M) in permanent primary congenital hypothyroidism group and 12 (52.2%) of them were dysgenesis (8 hypoplasia, 4 ectopia), and 11 (47.8%) dyshormonogenesis. In transient primary congenital hypothyroidism group, there were 25 cases (17M, 8F). The mean thyroid-stimulating hormone levels at diagnosis were similar in two groups. The mean thyroxin dose in permanent primary congenital hypothyroidism group was significantly higher than transient group at the time of thyroxin cessation (2.1±0.7, 1.5±0.5 mg/kg/d, respectively, p=0.004). Thyroxin dose ≥1.6 mcg/kg/d was 72% sensitive and 69.6% specific for predicting permenant primary congenital hypothyroidism. Transient primary congenital hypothyroidism is more frequent than expected and found often in males in the primary congenital hypothyroidism cases, started thyroxin therapy in neonatal period. While fT4, thyroid-stimulating hormone, Tg levels at diagnosis do not predict transient/permenant primary congenital hypothyroidism, thyroxin dose before the therapy cessation at the age of 3 may make the distinction between transient/permenant primary congenital hypothyroidism.

Low-loss, high-speed, high-T.sub.c superconducting bearings

DOEpatents

Hull, John R.; Mulcahy, Thomas M.; Uherka, Kenneth L.

1997-01-01

A flywheel energy storage device including an iron structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet. The stationary permanent magnet levitates the iron structure while the superconductor structure can stabilize the rotating iron structure.

Memory and representation in young children with Down syndrome: Exploring deferred imitation and object permanence.

PubMed

Rast, Mechthild; Meltzoff, Andrew N

1995-01-01

Deferred imitation and object permanence (OP) were tested in 48 young children with Down syndrome (DS), ranging from 20 to 43 months of age. Deferred imitation and high-level OP (invisible displacements) have long been held to be synchronous developments during sensory-motor "Stage 6" (18-24 months of age in unimpaired children). The results of the current study demonstrate deferred imitation in young children with DS, showing they can learn novel behaviors from observation and retain multiple models in memory. This is the first demonstration of deferred imitation in young children with DS. The average OP level passed in this sample was A-not-B, a task passed at 8-12 months of age in normally developing infants. Analyses showed that individual children who failed high-level OP (invisible displacements) could still perform deferred imitation. This indicates that deferred imitation and OP invisible displacements are not synchronous developments in children with DS. This asynchrony is compatible with new data from unimpaired children suggesting that deferred imitation and high-level OP entail separate and distinctive kinds of memory and representation.

Development of Permanent Magnet Reluctance Motor Suitable for Variable-Speed Drive for Electric Vehicle

NASA Astrophysics Data System (ADS)

Sakai, Kazuto; Takahashi, Norio; Shimomura, Eiji; Arata, Masanobu; Nakazawa, Yousuke; Tajima, Toshinobu

Regarding environmental and energy issues, increasing importance has been placed on energy saving in various systems. To save energy, it would be desirable if the total efficiency of various types of equipment were increased.Recently, a hybrid electric vehicle (HEV) and an electric vehicle (EV) have been developed. The use of new technologies will eventually lead to the realization of the new- generation vehicle with high efficiency. One new technology is the variable-speed drive over a wide range of speeds. The motor driving systems of the EV or the HEV must operate in the variable-speed range of up to 1:5. This has created the need for a high-efficiency motor that is capable of operation over a wide speed range. In this paper, we describe the concept of a novel permanent magnet reluctance motor (PRM) and discuss its characteristics. We developed the PRM, which has the capability of operating over a wide speed range with high efficiency. The PRM has a rotor with a salient pole, which generates magnetic anisotropy. In addition, the permanent magnets embedded in the rotor core counter the q-axis flux by the armature reaction. Then, the power density and the power factor increase. The PRM produces reluctance torque and torque by permanent magnet (PM) flux. The reluctance torque is 1 to 2 times larger than the PM torque. When the PRM operates over a constant-power speed range, the field component of the current will be regulated to maintain a constant voltage. The output power of the developed PRM is 8 to 250kW. It is clarified that the PRM operates at a wide variable-speed range (1:5) with high efficiency (92-97%). It is concluded that the PRM has high performance over a wide constant-power speed range. In addition, the PRM is constructed using a small PM, so that we can solve the problem of cost. Thus, the PRM is a superior machine that is suited for variable-speed drive applications.

24 CFR 35.110 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... and Definitions for All Programs. § 35.110 Definitions. Abatement means any set of measures designed... is designed and performed so as to be permanent (see definition of “permanent”). Enclosure means the... of abatement if it is designed to be permanent (see definition of “permanent”). Environmental...

24 CFR 35.110 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... and Definitions for All Programs. § 35.110 Definitions. Abatement means any set of measures designed... is designed and performed so as to be permanent (see definition of “permanent”). Enclosure means the... of abatement if it is designed to be permanent (see definition of “permanent”). Environmental...

24 CFR 35.110 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... and Definitions for All Programs. § 35.110 Definitions. Abatement means any set of measures designed... is designed and performed so as to be permanent (see definition of “permanent”). Enclosure means the... of abatement if it is designed to be permanent (see definition of “permanent”). Environmental...

24 CFR 35.110 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... and Definitions for All Programs. § 35.110 Definitions. Abatement means any set of measures designed... is designed and performed so as to be permanent (see definition of “permanent”). Enclosure means the... of abatement if it is designed to be permanent (see definition of “permanent”). Environmental...

24 CFR 35.110 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... and Definitions for All Programs. § 35.110 Definitions. Abatement means any set of measures designed... is designed and performed so as to be permanent (see definition of “permanent”). Enclosure means the... of abatement if it is designed to be permanent (see definition of “permanent”). Environmental...

36 CFR 223.83 - Contents of prospectus.

Code of Federal Regulations, 2010 CFR

2010-07-01

... specified roads to be constructed. (16) The estimated road construction cost and the estimated public works..., the prospectus shall also include: (1) The road standards applicable to construction of permanent... permanent roads. (3) A statement explaining how the Forest Service intends to perform road construction by...

Study of Various Slanted Air-Gap Structures of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

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

Tolbert, Leon M; Lee, Seong T

2010-01-01

This paper shows how to maximize the effect of the slanted air-gap structure of an interior permanent magnet synchronous motor with brushless field excitation (BFE) for application in a hybrid electric vehicle. The BFE structure offers high torque density at low speed and weakened flux at high speed. The unique slanted air-gap is intended to increase the output torque of the machine as well as to maximize the ratio of the back-emf of a machine that is controllable by BFE. This irregularly shaped air-gap makes a flux barrier along the d-axis flux path and decreases the d-axis inductance; as amore » result, the reluctance torque of the machine is much higher than a uniform air-gap machine, and so is the output torque. Also, the machine achieves a higher ratio of the magnitude of controllable back-emf. The determination of the slanted shape was performed by using magnetic equivalent circuit analysis and finite element analysis (FEA).« less

Permanent magnets as biasing mechanism for improving the performance of circular dielectric elastomer out-of-plane actuators

NASA Astrophysics Data System (ADS)

Loew, P.; Rizzello, G.; Seelecke, S.

2017-04-01

Dielectric Elastomers (DE) represent an attractive technology for the realization of mechatronic actuators, due to their lightweight, high energy density, high energy efficiency, scalability, and low noise features. In order to produce a stroke, a DE membrane needs to be pre-loaded with a mechanical biasing mechanism. In our previous works, we compared the stroke achieved with different biasing mechanisms for a circular out-of-plane DE Actuator (DEA), i.e., hanging masses, linear and bi-stable springs. The novel contribution of this paper is the investigation of a biasing design approach based on permanent magnets. The resulting magnet-based actuators are usually more compact than the spring-based ones, allowing to obtain more compact systems. Two design solutions are proposed and compared, namely a first one characterized by a stable actuation, and a second one which permits to achieve a higher stroke, but it is intrinsically unstable. The effectiveness of the novel design solution is assessed by means of several experiments.

Object permanence in orangutans (Pongo pygmaeus) and squirrel monkeys (Saimiri sciureus).

PubMed

de Blois, S T; Novak, M A; Bond, M

1998-06-01

The authors tested orangutans (Pongo pygmaeus) and squirrel monkeys (Saimiri sciureus) on object permanence tasks. In Experiment 1, orangutans solved all visible displacements and most invisible displacements except those involving movements into 2 boxes successively. In Experiment 2, performance of orangutans on double invisible displacements and control displacements (assessing simple strategies) was compared. Orangutans did not use the simple strategy of selecting the box visited last by the experimenter. Instead, poorer performance on double invisible displacements may have been related to increased memory requirements. In Experiment 3, squirrel monkeys were tested using the procedure of Experiment 1. Squirrel monkeys solved visible but did not comprehend invisible displacements. Results suggest that orangutans but not squirrel monkeys possess Stage 6 object permanence capabilities.

Low-loss, high-speed, high-{Tc} superconducting bearings

DOEpatents

Hull, J.R.; Mulcahy, T.M.; Uherka, K.L.

1997-06-24

A flywheel energy storage device is disclosed including an iron structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet. The stationary permanent magnet levitates the iron structure while the superconductor structure can stabilize the rotating iron structure. 15 figs.

Low-loss, high-speed, high-T.sub.C superconducting bearings

DOEpatents

Hull, John R.; Mulcahy, Thomas M.; Uherka, Kenneth L.

1996-01-01

A flywheel energy storage device including an iron structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet. The stationary permanent magnet levitates the iron structure while the superconductor structure can stabilize and levitate the rotating iron structure.

Characterization of Coronal Pulp Cells and Radicular Pulp Cells in Human Teeth.

PubMed

Honda, Masaki; Sato, Momoko; Toriumi, Taku

2017-09-01

Dental pulp has garnered much attention as an easily accessible postnatal tissue source of high-quality mesenchymal stem cells (MSCs). Since the discovery of dental pulp stem cells (DPSCs) in permanent third molars, stem cells from human exfoliated deciduous teeth and from supernumerary teeth (mesiodentes) have been identified as a population distinct from DPSCs. Dental pulp is divided into 2 parts based on the developing stage: the coronal pulp and the radicular pulp. Root formation begins after the crown part is completed. We performed a sequential study to examine the differences between the characteristics of coronal pulp cells (CPCs) and radicular pulp cells (RPCs) from permanent teeth, mesiodentes, and deciduous teeth. Interestingly, although we have not obtained any data on the difference between CPCs and RPCs in permanent teeth, there are some differences between the characteristics of CPCs and RPCs from mesiodentes and deciduous teeth. The MSC characteristics differed between the RPCs and CPCs, and the reprogramming efficiency for the generation of induced pluripotent stem cells was greater in RPCs than in CPCs from deciduous teeth. The proportion of CD105 + cells in CPCs versus that in RPCs varied in mesiodentes but not in permanent teeth. The results indicate that the proportion of CD105 + cells is an effective means of characterizing dental pulp cells in mesiodentes. Taken together, the stem cells in deciduous and supernumerary teeth share many characteristics, such as a high proliferation rate and an immunophenotype similar to that of DPSCs. Thus, mesiodentes accidentally encountered on radiographs by the general dental practitioner might be useful for stem cell therapy. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effects of Cement, Abutment Surface Pretreatment, and Artificial Aging on the Force Required to Detach Cantilever Fixed Dental Prostheses from Dental Implants.

PubMed

Kappel, Stefanie; Chepura, Taras; Schmitter, Marc; Rammelsberg, Peter; Rues, Stefan

To examine the in vitro effects of different cements, abutment surface preconditioning, and artificial aging on the maximum tensile force needed to detach cantilever fixed dental prostheses (FDPs) from dental implants with titanium abutments. A total of 32 tissue-level implants were combined with standardized titanium abutments. For each test group, eight cantilever FDPs were fabricated using selective laser melting (cobalt-chromium [CoCr] alloy). The inner surfaces of the cantilever FDPs and half of the abutments were sandblasted and then joined by use of four different cements (two permanent and two semi-permanent) in two different amounts per cement. Subgroups were tested after either artificial aging (thermocycling and chewing simulation) or 3 days of water storage. Finally, axial pull off-tests were performed for each abutment separately. Cement type and surface pretreatment significantly affected decementation behavior. The highest retention forces (approximately 1,200 N) were associated with sandblasted abutments and permanent cements. With unconditioned abutments, temporary cements (Fu < 100 N), as well as glass-ionomer cement (Fu ≈ 100 N), resulted in rather low retention forces. Zinc phosphate cement guaranteed high retention forces. After aging, retention was sufficient only for cementation with zinc phosphate cement and for the combination of sandblasted abutments and glass-ionomer cement. When glass-ionomer cement is used to fix cantilever FDPs on implants, sandblasting of standard titanium abutments may help prevent loss of retention. Retention forces were still high for FDPs fixed with zinc phosphate cement, even when the abutments were not pretreated. Use of permanent cements only, however, is recommended to prevent unwanted loosening of cantilever FDPs.

Variation of Electric Properties Between Surface Permanent Magnet and Interior Permanent Magnet Motor

NASA Astrophysics Data System (ADS)

Woo, Byung-Chul; Hong, Do-Kwan; Lee, Ji-Young

The most distinctive advantage of transverse flux motor(TFM) is high torque density which has prompted many researches into studying various design variants. TFM is well suited for low speed direct drive applications due to its high torque density. This paper deals with simulation based comparisons between a surface permanent magnet transverse flux motor(SPM-TFM) and an interior permanent magnet transverse flux motor(IPM-TFM). A commercial finite element analysis(FEA) software Maxwell 3D is used for electromagnetic field computation to fully analyze complex geometry of the TFMs. General characteristics, such as cogging torque, rated torque and torque ripple characteristics of the two TFMs are analyzed and compared by extensive 3D FEA.

Topology optimized and 3D printed polymer-bonded permanent magnets for a predefined external field

NASA Astrophysics Data System (ADS)

Huber, C.; Abert, C.; Bruckner, F.; Pfaff, C.; Kriwet, J.; Groenefeld, M.; Teliban, I.; Vogler, C.; Suess, D.

2017-08-01

Topology optimization offers great opportunities to design permanent magnetic systems that have specific external field characteristics. Additive manufacturing of polymer-bonded magnets with an end-user 3D printer can be used to manufacture permanent magnets with structures that had been difficult or impossible to manufacture previously. This work combines these two powerful methods to design and manufacture permanent magnetic systems with specific properties. The topology optimization framework is simple, fast, and accurate. It can also be used for the reverse engineering of permanent magnets in order to find the topology from field measurements. Furthermore, a magnetic system that generates a linear external field above the magnet is presented. With a volume constraint, the amount of magnetic material can be minimized without losing performance. Simulations and measurements of the printed systems show very good agreement.

Analysis and optimization of hybrid excitation permanent magnet synchronous generator for stand-alone power system

NASA Astrophysics Data System (ADS)

Wang, Huijun; Qu, Zheng; Tang, Shaofei; Pang, Mingqi; Zhang, Mingju

2017-08-01

In this paper, electromagnetic design and permanent magnet shape optimization for permanent magnet synchronous generator with hybrid excitation are investigated. Based on generator structure and principle, design outline is presented for obtaining high efficiency and low voltage fluctuation. In order to realize rapid design, equivalent magnetic circuits for permanent magnet and iron poles are developed. At the same time, finite element analysis is employed. Furthermore, by means of design of experiment (DOE) method, permanent magnet is optimized to reduce voltage waveform distortion. Finally, the validity of proposed design methods is validated by the analytical and experimental results.

RESIF national datacentre : new features and forthcoming evolutions

NASA Astrophysics Data System (ADS)

Pequegnat, C.; Volcke, P.; le Tanou, J.; Wolyniec, D.; Lecointre, A.; Guéguen, P.

2013-12-01

RESIF is a nationwide french project aimed at building an high quality system to observe and understand the inner earth. The goal is to create a network throughout mainland France comprising 750 seismometers and geodetic measurement instruments, 250 of which will be mobile, to enable the observation network to be focussed on specific investigation subjects and geographic locations. The RESIF data distribution centre, which is a part of the global project, is operated by the Université Joseph Fourier (Grenoble, France) and is being implemented for two years. Data from french broadband permanent network, strong motion permanent network, and mobile seismological antenna are freely accessible as realtime streams and continuous validated data, along with instrumental metadata, delivered using widely known formats and requests tools. New features of the datacentre are : - new modern distribution tools : two FDSN WEBservices has been implemented and deliver data and metadata. - new data and datasets : the number of permanent stations rose by over 40 % percent in one year and the RESIF archive now includes past data (down to 1995) and data from new networks. Moreover, data from mobile experiments prior to 2011 is progressively released, and data from new mobile experiments in the Alps and in the Pyrenean mountains is progressively integrated. - new infrastructures : (1) the RESIF databank is about to be connected to the grid storage of the University High Performance Computing (HPC) centre. As a scientific use case of this datacenter facility, a focus is made on intensive exploitation of combined data from permanent and mobile networks (2) the RESIF databank will be progressively hosted on a new shared storage facility operated by the Université Joseph Fourier. This infrastructure offers high availability data storage (both in blocks and files modes) as well as backup and long term archival capabilities, and will be fully operational at the beginning of 2014.

The trephine colostomy: a permanent left iliac fossa end colostomy without recourse to laparotomy.

PubMed Central

Senapati, A.; Phillips, R. K.

1991-01-01

An operative technique for performing a permanent end sigmoid colostomy without recourse to laparotomy is presented. The results from 16 patients have shown a very low morbidity. The technique was unsuccessful in three patients, each needing a formal laparotomy. PMID:1929133

PERMANENT PRIMER/REPLACEABLE TOPCOAT AIRCRAFT COATING SYSTEM WITH MINIMUM VOC AND CHROMIUM EXPOSURE - PHASE I

EPA Science Inventory

In Phase I, Foster-Miller, Inc., will develop the permanent primer replacement topcoat (PPRT), produce coated test panels, and analyze test panels for key performance properties. Topcoat stripping also will be demonstrated. The team includes coating experts and an aircraft ...

Assessment of Object Permanence in Severely Handicapped Students as a Function of Motor and Prompting Variables.

ERIC Educational Resources Information Center

Ilmer, Steven; And Others

1981-01-01

The study assessed object permanence construct performance in 20 severely handicapped students (4 to 14 years old) who were differentiated by treatment (prompt) condition and motor ability level. Results revealed a trait (motor ability) x treatment interaction. (Author/SB)

Permanency analysis on human electroencephalogram signals for pervasive Brain-Computer Interface systems.

PubMed

Sadeghi, Koosha; Junghyo Lee; Banerjee, Ayan; Sohankar, Javad; Gupta, Sandeep K S

2017-07-01

Brain-Computer Interface (BCI) systems use some permanent features of brain signals to recognize their corresponding cognitive states with high accuracy. However, these features are not perfectly permanent, and BCI system should be continuously trained over time, which is tedious and time consuming. Thus, analyzing the permanency of signal features is essential in determining how often to repeat training. In this paper, we monitor electroencephalogram (EEG) signals, and analyze their behavior through continuous and relatively long period of time. In our experiment, we record EEG signals corresponding to rest state (eyes open and closed) from one subject everyday, for three and a half months. The results show that signal features such as auto-regression coefficients remain permanent through time, while others such as power spectral density specifically in 5-7 Hz frequency band are not permanent. In addition, eyes open EEG data shows more permanency than eyes closed data.

Development of permanent magnet MnAlC/polymer composites and flexible filament for bonding and 3D-printing technologies

PubMed Central

Rial, Javier; de Vicente, Javier; Skårman, Björn; Vidarsson, Hilmar; Larsson, Per-Olof

2018-01-01

Abstract Searching for high-performance permanent magnets components with no limitation in shape and dimensions is highly desired to overcome the present design and manufacturing restrictions, which affect the efficiency of the final devices in energy, automotive and aerospace sectors. Advanced 3D-printing of composite materials and related technologies is an incipient route to achieve functional structures avoiding the limitations of traditional manufacturing. Gas-atomized MnAlC particles combined with polymer have been used in this work for fabricating scalable rare earth-free permanent magnet composites and extruded flexible filaments with continuous length exceeding 10 m. Solution casting has been used to synthesize homogeneous composites with tuned particles content, made of a polyethylene (PE) matrix embedding quasi-spherical particles of the ferromagnetic τ-MnAlC phase. A maximum filling factor of 86.5 and 72.3% has been obtained for the composite and the filament after extrusion, respectively. The magnetic measurements reveal no deterioration of the properties of the MnAlC particles after the composite synthesis and filament extrusion. The produced MnAlC/PE materials will serve as precursors for an efficient and scalable design and fabrication of end-products by different processing techniques (polymerized cold-compacted magnets and 3D-printing, respectively) in view of technological applications (from micro electromechanical systems to energy and transport applications). PMID:29887921

Remote Distributed Vibration Sensing Through Opaque Media Using Permanent Magnets

DOE PAGES

Chen, Yi; Mazumdar, Anirban; Brooks, Carlton F.; ...

2018-04-05

Vibration sensing is critical for a variety of applications from structural fatigue monitoring to understanding the modes of airplane wings. In particular, remote sensing techniques are needed for measuring the vibrations of multiple points simultaneously, assessing vibrations inside opaque metal vessels, and sensing through smoke clouds and other optically challenging environments. Here, in this paper, we propose a method which measures high-frequency displacements remotely using changes in the magnetic field generated by permanent magnets. We leverage the unique nature of vibration tracking and use a calibrated local model technique developed specifically to improve the frequency-domain estimation accuracy. The results showmore » that two-dimensional local models surpass the dipole model in tracking high-frequency motions. A theoretical basis for understanding the effects of electronic noise and error due to correlated variables is generated in order to predict the performance of experiments prior to implementation. Simultaneous measurements of up to three independent vibrating components are shown. The relative accuracy of the magnet-based displacement tracking with respect to the video tracking ranges from 40 to 190 μm when the maximum displacements approach ±5 mm and when sensor-to-magnet distances vary from 25 to 36 mm. Finally, vibration sensing inside an opaque metal vessel and mode shape changes due to damage on an aluminum beam are also studied using the wireless permanent-magnet vibration sensing scheme.« less

Development of permanent magnet MnAlC/polymer composites and flexible filament for bonding and 3D-printing technologies.

PubMed

Palmero, Ester M; Rial, Javier; de Vicente, Javier; Camarero, Julio; Skårman, Björn; Vidarsson, Hilmar; Larsson, Per-Olof; Bollero, Alberto

2018-01-01

Searching for high-performance permanent magnets components with no limitation in shape and dimensions is highly desired to overcome the present design and manufacturing restrictions, which affect the efficiency of the final devices in energy, automotive and aerospace sectors. Advanced 3D-printing of composite materials and related technologies is an incipient route to achieve functional structures avoiding the limitations of traditional manufacturing. Gas-atomized MnAlC particles combined with polymer have been used in this work for fabricating scalable rare earth-free permanent magnet composites and extruded flexible filaments with continuous length exceeding 10 m. Solution casting has been used to synthesize homogeneous composites with tuned particles content, made of a polyethylene (PE) matrix embedding quasi-spherical particles of the ferromagnetic τ -MnAlC phase. A maximum filling factor of 86.5 and 72.3% has been obtained for the composite and the filament after extrusion, respectively. The magnetic measurements reveal no deterioration of the properties of the MnAlC particles after the composite synthesis and filament extrusion. The produced MnAlC/PE materials will serve as precursors for an efficient and scalable design and fabrication of end-products by different processing techniques (polymerized cold-compacted magnets and 3D-printing, respectively) in view of technological applications (from micro electromechanical systems to energy and transport applications).

How Cold are the Floors of Lunar Polar Shadowed Craters?

NASA Technical Reports Server (NTRS)

Mendell, Wendell W.

2010-01-01

Almost five decades ago Watson, et al, [1] speculated that molecules of volatile species might accumulate within the cryogenic environments of permanently shadowed polar craters. The subject was largely a scientific curiosity until recently. In the mid-1980's, people began to seriously discuss the feasibility of long-term or permanent human settlement of the Moon. Given that the Moon was known be missing the compounds need to support life and that importing volatiles from Earth is prohibitively expensive, lunar colonists were pictured as processing the putative polar volatiles. A bistatic radar experiment performed with the Clementine spacecraft was interpreted to suggest the presence of large quantities of ice at some polar locations. [2] The neutron spectrometer aboard the Lunar Prospector spacecraft reported high concentrations of hydrogen in the polar regolith, [3] and some interpretations of the data set pointed to very high concentrations in permanently shadowed craters. The reformulation of civilian space policy in 2004, known as the Vision for Space Exploration, emphasized lunar exploration with eye toward development of economic returns from cislunar space and long-tern human presence on the Moon. The theme of finding lunar resources was an impetus for the inclusion of the Diviner Lunar Radiometer Experiment on the Lunar Reconnaissance Orbiter. Preliminary results from Diviner report an unexpectedly low temperature down to 35K in the depths of some craters. [4

Remote Distributed Vibration Sensing Through Opaque Media Using Permanent Magnets

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

Chen, Yi; Mazumdar, Anirban; Brooks, Carlton F.

Vibration sensing is critical for a variety of applications from structural fatigue monitoring to understanding the modes of airplane wings. In particular, remote sensing techniques are needed for measuring the vibrations of multiple points simultaneously, assessing vibrations inside opaque metal vessels, and sensing through smoke clouds and other optically challenging environments. Here, in this paper, we propose a method which measures high-frequency displacements remotely using changes in the magnetic field generated by permanent magnets. We leverage the unique nature of vibration tracking and use a calibrated local model technique developed specifically to improve the frequency-domain estimation accuracy. The results showmore » that two-dimensional local models surpass the dipole model in tracking high-frequency motions. A theoretical basis for understanding the effects of electronic noise and error due to correlated variables is generated in order to predict the performance of experiments prior to implementation. Simultaneous measurements of up to three independent vibrating components are shown. The relative accuracy of the magnet-based displacement tracking with respect to the video tracking ranges from 40 to 190 μm when the maximum displacements approach ±5 mm and when sensor-to-magnet distances vary from 25 to 36 mm. Finally, vibration sensing inside an opaque metal vessel and mode shape changes due to damage on an aluminum beam are also studied using the wireless permanent-magnet vibration sensing scheme.« less

Low-loss, high-speed, high-{Tc} superconducting bearings

DOEpatents

Hull, J.R.; Mulcahy, T.M.; Uherka, K.L.

1996-07-30

A flywheel energy storage device is disclosed including an iron structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet. The stationary permanent magnet levitates the iron structure while the superconductor structure can stabilize and levitate the rotating iron structure. 15 figs.

Humans permanently occupied the Andean highlands by at least 7 ka

PubMed Central

Stefanescu, Ioana C.; Garcia-Putnam, Alexander; Aldenderfer, Mark S.; Clementz, Mark T.; Murphy, Melissa S.; Llave, Carlos Viviano; Watson, James T.

2017-01-01

High-elevation environments above 2500 metres above sea level (m.a.s.l.) were among the planet's last frontiers of human colonization. Research on the speed and tempo of this colonization process is active and holds implications for understanding rates of genetic, physiological and cultural adaptation in our species. Permanent occupation of high-elevation environments in the Andes Mountains of South America tentatively began with hunter–gatherers around 9 ka according to current archaeological estimates, though the timing is currently debated. Recent observations on the archaeological site of Soro Mik'aya Patjxa (8.0–6.5 ka), located at 3800 m.a.s.l. in the Andean Altiplano, offer an opportunity to independently test hypotheses for early permanent use of the region. This study observes low oxygen (δ18O) and high carbon (δ13C) isotope values in human bone, long travel distances to low-elevation zones, variable age and sex structure in the human population and an absence of non-local lithic materials. These independent lines of evidence converge to support a model of permanent occupation of high elevations and refute logistical and seasonal use models. The results constitute the strongest empirical support to date for permanent human occupation of the Andean highlands by hunter–gatherers before 7 ka. PMID:28680685

Study on a New Combination Method and High Efficiency Outer Rotor Type Permanent Magnet Motors

NASA Astrophysics Data System (ADS)

Enomoto, Yuji; Kitamura, Masashi; Motegi, Yasuaki; Andoh, Takashi; Ochiai, Makoto; Abukawa, Toshimi

The segment stator core, high space factor coil, and high efficiency magnet are indispensable technologies in the development of compact and a high efficiency motors. But adoption of the segment stator core and high space factor coil has not progressed in the field of outer rotor type motors, for the reason that the inner components cannot be laser welded together. Therefore, we have examined a segment stator core combination technology for the purposes of getting a large increase in efficiency and realizing miniaturization. We have also developed a characteristic estimation method which provides the most suitable performance for segment stator core motors.

Development of the Object Permanence Concept in Cleft Lip and Palate and Noncleft Lip and Palate Infants.

ERIC Educational Resources Information Center

Pecyna, Paula M.; And Others

1987-01-01

The development of the concept of object permanence was investigated with eight infants with cleft lip/palate and four nonimpaired infants. Superior performance of the cleft lip/palate group was found, possibly due to increased environmental stimulation provided by parents. (DB)

Post-Training Reversible Inactivation of the Hippocampus Enhances Novel Object Recognition Memory

ERIC Educational Resources Information Center

Oliveira, Ana M. M.; Hawk, Joshua D.; Abel, Ted; Havekes, Robbert

2010-01-01

Research on the role of the hippocampus in object recognition memory has produced conflicting results. Previous studies have used permanent hippocampal lesions to assess the requirement for the hippocampus in the object recognition task. However, permanent hippocampal lesions may impact performance through effects on processes besides memory…

40 CFR 60.2855 - What must I do if I plan to permanently close my air curtain incinerator and not restart it?

Code of Federal Regulations, 2014 CFR

2014-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY... Units Model Rule-Air Curtain Incinerators § 60.2855 What must I do if I plan to permanently close my air...

On Training Generalized Thinking.

ERIC Educational Resources Information Center

Kahn, James V.

A two-phased training study attempted (1) to accelerate the rate at which a total of 8 severely and profoundly retarded children (mean age 57 months) developed the Piagetian concept of object permanence and (2) to demonstrate generalization of the higher performance on object permanence scale to other scales of sensorimotor intelligence and to the…

A Few Simple Classroom Experiments with a Permanent U-Shaped Magnet

ERIC Educational Resources Information Center

Babovic, Miloš; Babovic, Vukota

2017-01-01

A few simple experiments in the magnetic field of a permanent U-shaped magnet are described. Among them, pin oscillations inside the magnet are particularly interesting. These easy to perform and amusing measurements can help pupils understand magnetic phenomena and mutually connect knowledge of various physics branches.

Permanent Base Groups in Broadcast Journalism Instruction.

ERIC Educational Resources Information Center

Boldoc, William J.

An instructor increases student performance, participation, and motivation in broadcast journalism and other media courses through the base group cooperative learning model. Base groups are a specific form of cooperative learning which enables students to become actively involved in small-group discussions and learning with a permanent group of…

Method and apparatus for measuring gravitational acceleration utilizing a high temperature superconducting bearing

DOEpatents

Hull, John R.

2000-01-01

Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operating temperature at or below 77K, whereby cooling may be accomplished with liquid nitrogen.

Study and review of permanent magnets for electric vehicle propulsion motors

NASA Technical Reports Server (NTRS)

Strnat, K. J.

1983-01-01

A study of permanent magnets (PM) was performed in support of the DOE/NASA electric and hybrid vehicle program. PM requirements for electric propulsion motors are analyzed, design principles and relevant properties of magnets are discussed. Available PM types are reviewed. For the needed high-grade magnets, design data, commercial varieties and sources are tabulated, based on a survey of vendors. Economic factors such as raw material availability, production capability and cost are analyzed, especially for cobalt and the rare earths. Extruded Mn-Al-C magnets from Japan were experimentally characterized. Dynamic magnetic data for the range -50 deg to +150 deg C and some mechanical properties are reported. The state of development of the important PM material families is reviewed. Feasible improvements or new developments of magnets for electric vehicle motors are identified.

Dental age estimation in Japanese individuals combining permanent teeth and third molars.

PubMed

Ramanan, Namratha; Thevissen, Patrick; Fleuws, Steffen; Willems, G

2012-12-01

The study aim was, firstly, to verify the Willems et al. model on a Japanese reference sample. Secondly to develop a Japanese reference model based on the Willems et al. method and to verify it. Thirdly to analyze the age prediction performance adding tooth development information of third molars to permanent teeth. Retrospectively 1877 panoramic radiographs were selected in the age range between 1 and 23 years (1248 children, 629 sub-adults). Dental development was registered applying Demirjian 's stages of the mandibular left permanent teeth in children and Köhler stages on the third molars. The children's data were, firstly, used to validate the Willems et al. model (developed a Belgian reference sample), secondly, split ino a training and a test sample. On the training sample a Japanese reference model was developed based on the Willems method. The developed model and the Willems et al; model were verified on the test sample. Regression analysis was used to detect the age prediction performance adding third molar scores to permanent tooth scores. The validated Willems et al. model provided a mean absolute error of 0.85 and 0.75 years in females and males, respectively. The mean absolute error in the verified Willems et al. and the developed Japanese reference model was 0.85, 0.77 and 0.79, 0.75 years in females and males, respectively. On average a negligible change in root mean square error values was detected adding third molar scores to permanent teeth scores. The Belgian sample could be used as a reference model to estimate the age of the Japanese individuals. Combining information from the third molars and permanent teeth was not providing clinically significant improvement of age predictions based on permanent teeth information alone.

Micromagnetics of rare-earth efficient permanent magnets

NASA Astrophysics Data System (ADS)

Fischbacher, Johann; Kovacs, Alexander; Gusenbauer, Markus; Oezelt, Harald; Exl, Lukas; Bance, Simon; Schrefl, Thomas

2018-05-01

The development of permanent magnets containing less or no rare-earth elements is linked to profound knowledge of the coercivity mechanism. Prerequisites for a promising permanent magnet material are a high spontaneous magnetization and a sufficiently high magnetic anisotropy. In addition to the intrinsic magnetic properties the microstructure of the magnet plays a significant role in establishing coercivity. The influence of the microstructure on coercivity, remanence, and energy density product can be understood by using micromagnetic simulations. With advances in computer hardware and numerical methods, hysteresis curves of magnets can be computed quickly so that the simulations can readily provide guidance for the development of permanent magnets. The potential of rare-earth reduced and rare-earth free permanent magnets is investigated using micromagnetic simulations. The results show excellent hard magnetic properties can be achieved in grain boundary engineered NdFeB, rare-earth magnets with a ThMn12 structure, Co-based nano-wires, and L10-FeNi provided that the magnet’s microstructure is optimized.

Magnetically-driven medical robots: An analytical magnetic model for endoscopic capsules design

NASA Astrophysics Data System (ADS)

Li, Jing; Barjuei, Erfan Shojaei; Ciuti, Gastone; Hao, Yang; Zhang, Peisen; Menciassi, Arianna; Huang, Qiang; Dario, Paolo

2018-04-01

Magnetic-based approaches are highly promising to provide innovative solutions for the design of medical devices for diagnostic and therapeutic procedures, such as in the endoluminal districts. Due to the intrinsic magnetic properties (no current needed) and the high strength-to-size ratio compared with electromagnetic solutions, permanent magnets are usually embedded in medical devices. In this paper, a set of analytical formulas have been derived to model the magnetic forces and torques which are exerted by an arbitrary external magnetic field on a permanent magnetic source embedded in a medical robot. In particular, the authors modelled cylindrical permanent magnets as general solution often used and embedded in magnetically-driven medical devices. The analytical model can be applied to axially and diametrically magnetized, solid and annular cylindrical permanent magnets in the absence of the severe calculation complexity. Using a cylindrical permanent magnet as a selected solution, the model has been applied to a robotic endoscopic capsule as a pilot study in the design of magnetically-driven robots.

Body mass index, blood pressure, and glucose and lipid metabolism among permanent and fixed-term workers in the manufacturing industry: a cross-sectional study.

PubMed

Inoue, Mariko; Minami, Masahide; Yano, Eiji

2014-02-27

Temporary employment, a precarious form of employment, is recognized as social determinant of poor health. However, evidence supporting precarious employment as a risk factor for health is mainly obtained from subjective data. Studies using objective clinical measurement data in the assessment of health status are limited. This study compared body mass index (BMI), lipid and glucose metabolism, and health-related lifestyle factors between permanent workers and fixed-term workers employed in the manufacturing industry. Data of 1,701 male manufacturing industry workers <50 years old in Japan were collected and analyzed. Anthropometric data were BMI, calculated using measured height and weight of study participants, and blood pressure. For lipid metabolism, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels were determined. For glucose metabolism, fasting plasma glucose and hemoglobin A1c (HbA1c) levels were measured. Multiple regression analysis adjusted for age and lifestyle factors was performed. BMI was significantly higher in permanent workers (22.9 kg/m2) compared with fixed-term workers (22.4 kg/m2). The leaner population (BMI < 18.5) was greater among fixed-term workers (8.3%) compared with permanent workers (4.0%), whereas the overweight population (BMI ≥ 25.0) was greater among permanent workers (21.4%) compared with fixed-term workers (18.1%). Although fixed-term workers tended not to be overweight, regression analysis adjusted for age and lifestyle factors suggested that fixed-term employment was significantly associated with higher blood pressure (systolic β = 2.120, diastolic β = 2.793), triglyceride (β = 11.147), fasting blood glucose (β = 2.218), and HbA1c (β = 0.107) compared with permanent workers (all p < 0.01). Fixed-term workers showed more health risks, such as poorer blood pressure and lipid and glucose metabolism, even when adjusted for age and lifestyle variables, although BMI of fixed-term workers were lower than permanent workers. Precarious work might contribute to a deteriorating health status even among less overweight populations.

Dental caries experience among indigenous children and adolescents.

PubMed

Gonçalves, Érica M; Cavalcanti, Laysa C; Firmino, Ramon T; Ribeiro, Gustavo L; Granville-Garcia, Ana F; Menezes, Valdenice A

2015-06-01

Investigations into the oral health status of indigenous populations are scarce. The aim of this study was to evaluate caries experience and associated factors among 342 indigenous children and adolescents aged 5-15 years of the Xukuru community in the municipality of Pesqueira, Brazil. A cross-sectional census study was carried out using the criteria of the World Health Organization to determine caries experience. Examinations were performed by two calibrated dentists and a questionnaire was administered to parents/caregivers addressing socio-demographic data, diet and oral hygiene habits. Logistic regression analysis were performed, with dmft and DMFT as the dependent variables (P < 0.05). Caries experience (dmft/DMFT) was high in both the primary and permanent dentition (75.6% and 62.9%, respectively). Mean dmft and DMFT indices were 3.11 and 2.21, respectively. Caries experience in the primary dentition was associated with children residing in villages far from urban areas (P = 0.016), while caries in the permanent dentition was associated with older children (P < 0.001) and with children from villages at an intermediate distance and far from urban areas (P < 0.001). The indigenous subjects exhibited a high degree of caries experience, which was associated with age and group of villages. Public policies are needed to improve the oral health status of this population.

Use of a surgical helmet system to minimize splash injury during percutaneous renal surgery in high-risk patients.

PubMed

Eandi, Jonathan A; Nanigian, Dana K; Smith, William H; Low, Roger K

2008-12-01

The transmission risk to surgeons performing percutaneous renal surgery on patients who are infected with human immunodeficiency virus/acquired immunodeficiency syndrome, hepatitis B, or hepatitis C is unknown. A recent study found 55% of surgeons' masks contain evidence of blood splash contamination after percutaneous nephrolithotomy. While the risk of infectious disease transmission to the surgeon after mucocutaneous exposure is unknown, the incapacitating disease these pathogens cause can have a devastating and permanent effect on a surgeon's career. We describe our use of a surgical helmet system when performing percutaneous renal surgery on high-risk patients to minimize risk of splash injury and transmission of blood-borne pathogens.

Frozen Section Evaluation of Margin Status in Primary Squamous Cell Carcinomas of the Head and Neck: A Correlation Study of Frozen Section and Final Diagnoses.

PubMed

Layfield, Eleanor M; Schmidt, Robert L; Esebua, Magda; Layfield, Lester J

2018-06-01

Frozen section is routinely used for intraoperative margin evaluation in carcinomas of the head and neck. We studied a series of frozen sections performed for margin status of head and neck tumors to determine diagnostic accuracy. All frozen sections for margin control of squamous carcinomas of the head and neck were studied from a 66 month period. Frozen and permanent section diagnoses were classified as negative or malignant. Correlation of diagnoses was performed to determine accuracy. One thousand seven hundred and ninety-six pairs of frozen section and corresponding permanent section diagnoses were obtained. Discordances were found in 55 (3.1%) pairs. In 35 pairs (1.9%), frozen section was reported as benign, but permanent sections disclosed carcinoma. In 21 cases, the discrepancy was due to sampling and in the remaining cases it was an interpretive error. In 20 cases (1.1%), frozen section was malignant, but the permanent section was interpreted as negative. Frozen section is an accurate method for evaluation of operative margins for head and neck carcinomas with concordance between frozen and permanent results of 97%. Most errors are false negative results with the majority of these being due to sampling issues.

High stoma prevalence and stoma reversal complications following anterior resection for rectal cancer: a population-based multicentre study.

PubMed

Holmgren, K; Kverneng Hultberg, D; Haapamäki, M M; Matthiessen, P; Rutegård, J; Rutegård, M

2017-12-01

Fashioning a defunctioning stoma is common when performing an anterior resection for rectal cancer in order to avoid and mitigate the consequences of an anastomotic leakage. We investigated the permanent stoma prevalence, factors influencing stoma outcome and complication rates following stoma reversal surgery. Patients who had undergone an anterior resection for rectal cancer between 2007 and 2013 in the northern healthcare region were identified using the Swedish Colorectal Cancer Registry and were followed until the end of 2014 regarding stoma outcome. Data were retrieved by a review of medical records. Multiple logistic regression was used to evaluate predefined risk factors for stoma permanence. Risk factors for non-reversal of a defunctioning stoma were also analysed, using Cox proportional-hazards regression. A total of 316 patients who underwent anterior resection were included, of whom 274 (87%) were defunctioned primarily. At the end of the follow-up period 24% had a permanent stoma, and 9% of patients who underwent reversal of a stoma experienced major complications requiring a return to theatre, need for intensive care or mortality. Anastomotic leakage and tumour Stage IV were significant risk factors for stoma permanence. In this series, partial mesorectal excision correlated with a stoma-free outcome. Non-reversal was considerably more prevalent among patients with leakage and Stage IV; Stage III patients at first had a decreased reversal rate, which increased after the initial year of surgery. Stoma permanence is common after anterior resection, while anastomotic leakage and advanced tumour stage decrease the chances of a stoma-free outcome. Stoma reversal surgery entails a significant risk of major complications. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

A Way to Select Electrical Sheets of the Segment Stator Core Motors.

NASA Astrophysics Data System (ADS)

Enomoto, Yuji; Kitamura, Masashi; Sakai, Toshihiko; Ohara, Kouichiro

The segment stator core, high density winding coil, high-energy-product permanent magnet are indispensable technologies in the development of a compact and also high efficient motors. The conventional design method for the segment stator core mostly depended on experienced knowledge of selecting a suitable electromagnetic material, far from optimized design. Therefore, we have developed a novel design method in the selection of a suitable electromagnetic material based on the correlation evaluation between the material characteristics and motor performance. It enables the selection of suitable electromagnetic material that will meet the motor specification.

Modeling and simulation of soft sensor design for real-time speed and position estimation of PMSM.

PubMed

Omrane, Ines; Etien, Erik; Dib, Wissam; Bachelier, Olivier

2015-07-01

This paper deals with the design of a speed soft sensor for permanent magnet synchronous motor. At high speed, model-based soft sensor is used and it gives excellent results. However, it fails to deliver satisfactory performance at zero or very low speed. High-frequency soft sensor is used at low speed. We suggest to use a model-based soft sensor together with the high-frequency soft sensor to overcome the limitations of the first one at low speed range. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Levitation pressure and friction losses in superconducting bearings

DOEpatents

Hull, John R.

2001-01-01

A superconducting bearing having at least one permanent magnet magnetized with a vertical polarization. The lower or stator portion of the bearing includes an array of high-temperature superconducting elements which are comprised of a plurality of annular rings. An annular ring is located below each permanent magnet and an annular ring is offset horizontally from at least one of the permanent magnets. The rings are composed of individual high-temperature superconducting elements located circumferentially along the ring. By constructing the horizontally-offset high-temperature superconducting ring so that the c-axis is oriented in a radial direction, a higher levitation force can be achieved. Such an orientation will also provide substantially lower rotational drag losses in the bearing.

Low Power Magnetic Bearing Design for High Speed Rotating Machinery

NASA Technical Reports Server (NTRS)

Allaire, P. E.; Maslen, E. H.; Humphris, R. R.; Sortore, C. K.; Studer, P. A.

1992-01-01

Magnetic suspension technology has advanced to the point of being able to offer a number of advantages to a variety of applications in the rotating machinery and aerospace fields. One strong advantage is the decrease in power consumption. The design and construction of a set of permanent magnet biased, actively controlled magnetic bearing for a flexible rotor are presented. Both permanent magnets and electromagnets are used in a configuration which effectively provides the necessary fluxes in the appropriate air gaps, while simultaneously keeping the undesirable destabilizing forces to a minimum. The design includes two radial bearings and a thrust bearing. The theoretical development behind the design is briefly discussed. Experimental performance results for a set of operating prototype bearings is presented. The results include measurements of load capacity, bearing stiffness and damping, and the dynamic response of the rotor. With few exceptions, the experimental results matched very well with the predicted performance. The power consumption of these bearings was found to be significantly reduced from that for a comparable set of all electromagnetic bearings.

Design study and performance analysis of 12S-14P field excitation flux switching motor for hybrid electric vehicle

NASA Astrophysics Data System (ADS)

Husin, Zhafir Aizat; Sulaiman, Erwan; Khan, Faisal; Mazlan, Mohamed Mubin Aizat; Othman, Syed Muhammad Naufal Syed

2015-05-01

This paper presents a new structure of 12slot-14pole field excitation flux switching motor (FEFSM) as an alternative candidate of non-Permanent Magnet (PM) machine for HEV drives. Design study, performance analysis and optimization of field excitation flux switching machine with non-rare-earth magnet for hybrid electric vehicle drive applications is done. The stator of projected machine consists of iron core made of electromagnetic steels, armature coils and field excitation coils as the only field mmf source. The rotor is consisted of only stack of iron and hence, it is reliable and appropriate for high speed operation. The design target is a machine with the maximum torque, power and power density, more than 210Nm, 123kW and 3.5kW/kg, respectively, which competes with interior permanent magnet synchronous machine used in existing hybrid electric vehicle. Some design feasibility studies on FEFSM based on 2D-FEA and deterministic optimization method will be applied to design the proposed machine.

Performance of a Cylindrical Hall-Effect Thruster with Magnetic Field Generated by Permanent Magnets

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Raitses, Yevgeny; Fisch, Nathaniel J.

2008-01-01

While Hall thrusters can operate at high efficiency at kW power levels, it is difficult to construct one that operates over a broad envelope down to 100W while maintaining an efficiency of 45- 55%. Scaling to low power while holding the main dimensionless parameters constant requires a decrease in the thruster channel size and an increase in the magnetic field strength. Increasing the magnetic field becomes technically challenging since the field can saturate the miniaturized inner components of the magnetic circuit and scaling down the magnetic circuit leaves very little room for magnetic pole pieces and heat shields. An alternative approach is to employ a cylindrical Hall thruster (CHT) geometry. Laboratory model CHTs have operated at power levels ranging from the order of 50 Watts up to 1 kW. These thrusters exhibit performance characteristics which are comparable to conventional, annular Hall thrusters of similar size. Compared to the annular Hall thruster, the CHT has a lower insulator surface area to discharge chamber volume ratio. Consequently, there is the potential for reduced wall losses in the channel of a CHT, and any reduction in wall losses should translate into lower channel heating rates and reduced erosion. This makes the CHT geometry promising for low-power applications. Recently, a CHT that uses permanent magnets to produce the magnetic field topology was tested. This thruster has the promise of reduced power consumption over previous CHT iterations that employed electromagnets. Data are presented for two purposes: to expose the effect different controllable parameters have on the discharge and to summarize performance measurements (thrust, Isp, efficiency) obtained using a thrust stand. These data are used to gain insight into the thruster's operation and to allow for quantitative comparisons between the permanent magnet CHT and the electromagnet CHT.

Comparison of effects of overload on parameters and performance of samarium-cobalt and strontium-ferrite radially oriented permanent magnet brushless DC motors

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

Demerdash, N.A.; Nehl, T.W.; Nyamusa, T.A.

1985-08-01

Effects of high momentary overloads on the samarium-cobalt and strontium-ferrite permanent magnets and the magnetic field in electronically commutated brushless dc machines, as well as their impact on the associated machine parameters were studied. The effect of overload on the machine parameters, and subsequently on the machine system performance was also investigated. This was accomplished through the combined use of finite element analysis of the magnetic field in such machines, perturbation of the magnetic energies to determine machine inductances, and dynamic simulation of the performance of brushless dc machines, when energized from voltage source inverters. These effects were investigated throughmore » application of the above methods to two equivalent 15 hp brushless dc motors, one of which was built with samarium-cobalt magnets, while the other was built with strontium- ferrite magnets. For momentary overloads as high as 4.5 p.u. magnet flux reductions of 29% and 42% of the no load flux were obtained in the samarium-cobalt and strontiumferrite machines, respectively. Corresponding reductions in the line to line armature inductances of 52% and 46% of the no load values were reported for the samarium-cobalt and strontium-ferrite cases, respectively. The overload affected the profiles and magnitudes of armature induced back emfs. Subsequently, the effects of overload on machine parameters were found to have significant impact on the performance of the machine systems, where findings indicate that the samarium-cobalt unit is more suited for higher overload duties than the strontium-ferrite machine.« less

Random regression models using different functions to model milk flow in dairy cows.

PubMed

Laureano, M M M; Bignardi, A B; El Faro, L; Cardoso, V L; Tonhati, H; Albuquerque, L G

2014-09-12

We analyzed 75,555 test-day milk flow records from 2175 primiparous Holstein cows that calved between 1997 and 2005. Milk flow was obtained by dividing the mean milk yield (kg) of the 3 daily milking by the total milking time (min) and was expressed as kg/min. Milk flow was grouped into 43 weekly classes. The analyses were performed using a single-trait Random Regression Models that included direct additive genetic, permanent environmental, and residual random effects. In addition, the contemporary group and linear and quadratic effects of cow age at calving were included as fixed effects. Fourth-order orthogonal Legendre polynomial of days in milk was used to model the mean trend in milk flow. The additive genetic and permanent environmental covariance functions were estimated using random regression Legendre polynomials and B-spline functions of days in milk. The model using a third-order Legendre polynomial for additive genetic effects and a sixth-order polynomial for permanent environmental effects, which contained 7 residual classes, proved to be the most adequate to describe variations in milk flow, and was also the most parsimonious. The heritability in milk flow estimated by the most parsimonious model was of moderate to high magnitude.

Levitation Performance of Two Opposed Permanent Magnet Pole-Pair Separated Conical Bearingless Motors

NASA Technical Reports Server (NTRS)

Kascak, Peter; Jansen, Ralph; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

2013-01-01

In standard motor applications, rotor suspension with traditional mechanical bearings represents the most economical solution. However, in certain high performance applications, rotor suspension without contacting bearings is either required or highly beneficial. Examples include applications requiring very high speed or extreme environment operation, or with limited access for maintenance. This paper expands upon a novel bearingless motor concept, in which two motors with opposing conical air-gaps are used to achieve full five-axis levitation and rotation of the rotor. Force in this motor is created by deliberately leaving the motor s pole-pairs unconnected, which allows the creation of different d-axis flux in each pole pair. This flux imbalance is used to create lateral force. This approach is different than previous bearingless motor designs, which require separate windings for levitation and rotation. This paper examines the predicted and achieved suspension performance of a fully levitated prototype bearingless system.

Outbreak of Mycobacterium haemophilum infections after permanent makeup of the eyebrows.

PubMed

Giulieri, Stefano; Morisod, Benoit; Edney, Timothy; Odman, Micaela; Genné, Daniel; Malinverni, Raffaele; Hammann, Catherine; Musumeci, Enrico; Voide, Cathy; Greub, Gilbert; Masserey, Eric; Bille, Jacques; Cavassini, Matthias; Jaton, Katia

2011-02-15

We report a Mycobacterium haemophilum outbreak after permanent make-up of the eyebrows performed by the same freelance artist. Twelve patients presented an eyebrow lesion and cervical lymphadenitis. All were treated with antibiotics. Surgery was required in 10 cases. M. haemophilum DNA was identified in the make-up ink.

Effects of Selected Object Characteristics on Object Permanence Test Performance.

ERIC Educational Resources Information Center

Lingle, Kathleen M.; Lingle, John H.

A study was conducted to investigate the degree to which both object familiarity and motivational factors influence infants' search behavior in an object permanence test. Infants' search behavior for an unfamiliar test object was compared with search behavior for (a) an experientially familiar object that each infant had played with daily for a…

Effort-reward imbalance and its association with health among permanent and fixed-term workers

PubMed Central

2010-01-01

Background In the past decade, the changing labor market seems to have rejected the traditional standards employment and has begun to support a variety of non-standard forms of work in their place. The purpose of our study was to compare the degree of job stress, sources of job stress, and association of high job stress with health among permanent and fixed-term workers. Methods Our study subjects were 709 male workers aged 30 to 49 years in a suburb of Tokyo, Japan. In 2008, we conducted a cross-sectional study to compare job stress using an effort-reward imbalance (ERI) model questionnaire. Lifestyles, subjective symptoms, and body mass index were also observed from the 2008 health check-up data. Results The rate of job stress of the high-risk group measured by ERI questionnaire was not different between permanent and fixed-term workers. However, the content of the ERI components differed. Permanent workers were distressed more by effort, overwork, or job demand, while fixed-term workers were distressed more by their job insecurity. Moreover, higher ERI was associated with existence of subjective symptoms (OR = 2.07, 95% CI: 1.42-3.03) and obesity (OR = 2.84, 95% CI:1.78-4.53) in fixed-term workers while this tendency was not found in permanent workers. Conclusions Our study showed that workers with different employment types, permanent and fixed-term, have dissimilar sources of job stress even though their degree of job stress seems to be the same. High ERI was associated with existing subjective symptoms and obesity in fixed-term workers. Therefore, understanding different sources of job stress and their association with health among permanent and fixed-term workers should be considered to prevent further health problems. PMID:21054838

Durability of structural lumber products at high temperatures. Part I, 66C at 75% RH and 82C at 30% RH

Treesearch

David W. Green; James W. Evans; Bruce A. Craig

2003-01-01

The effect of temperature on properties can be separated into reversible and permanent effects. The National Design Specification (NDS) provides factors (Ct) for reducing properties for reversible effects but provides little guidance on permanent effects. The primary objective of this paper is to evaluate the effect of prolonged heating (permanent effect) on the...

Recent progress in developing durable and permanent impeller pump.

PubMed

Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

2002-04-01

Since 1980s, the author's impeller pump has successively achieved the device implantability, blood compatibility and flow pulsatility. In order to realize a performance durability, the author has concentrated in past years on solving the bearing problems of the impeller pump. Recent progress has been obtained in developing durable and permanent impeller blood pumps. At first, a durable impeller pump with rolling bearing and purge system has been developed, in which the wear-less rollers made of super-high-molecular weight polythene make the pump to work for years without mechanical wear; and the purge system enables the bearing to work in saline and heparin, and no thrombus therefore could be formed. Secondly, a durable centrifugal pump with rolling bearing and axially reciprocating impeller has been developed, the axial reciprocation of rotating impeller makes the fresh blood in and out of the bearing and to wash the rollers once a circle; in such way, no thrombus could be formed and no fluid infusion is necessary, which may bring inconvenience and discomfort to the receptors. Finally, a permanent maglev impeller pump has been developed, its rotor is suspended and floating in the blood under the action of permanent magnetic force and nonmagnetic forces, without need for position measurement and feed-back control. In conclusion, an implantable, pulsatile, and blood compatible impeller pump with durability may have more extensive applications than ever before and could replace the donor heart for transplantation in the future.

Precise Alignment and Permanent Mounting of Thin and Lightweight X-ray Segments

NASA Technical Reports Server (NTRS)

Biskach, Michael P.; Chan, Kai-Wing; Hong, Melinda N.; Mazzarella, James R.; McClelland, Ryan S.; Norman, Michael J.; Saha, Timo T.; Zhang, William W.

2012-01-01

To provide observations to support current research efforts in high energy astrophysics. future X-ray telescope designs must provide matching or better angular resolution while significantly increasing the total collecting area. In such a design the permanent mounting of thin and lightweight segments is critical to the overall performance of the complete X-ray optic assembly. The thin and lightweight segments used in the assemhly of the modules are desigued to maintain and/or exceed the resolution of existing X-ray telescopes while providing a substantial increase in collecting area. Such thin and delicate X-ray segments are easily distorted and yet must be aligned to the arcsecond level and retain accurate alignment for many years. The Next Generation X-ray Optic (NGXO) group at NASA Goddard Space Flight Center has designed, assembled. and implemented new hardware and procedures mth the short term goal of aligning three pairs of X-ray segments in a technology demonstration module while maintaining 10 arcsec alignment through environmental testing as part of the eventual design and construction of a full sized module capable of housing hundreds of X-ray segments. The recent attempts at multiple segment pair alignment and permanent mounting is described along with an overview of the procedure used. A look into what the next year mll bring for the alignment and permanent segment mounting effort illustrates some of the challenges left to overcome before an attempt to populate a full sized module can begin.

Preparation of Permanent Mold Coating Using Magnesia Powder for Magnesium Alloys

NASA Astrophysics Data System (ADS)

Guo, Guangsi; Wang, Guangtai; Yu, Haifeng; Ye, Sheng

A kind of permanent mold coating for magnesium alloy was developed using magnesia powder and diatomite as refractory aggregate. The properties of the coating were tested and analyzed by various ingredients. The final ingredient was determined through the tests which are to find out the optimal proportion of two kinds of aggregate and the influences to coating properties by changing the proportion of binder and suspending agents. The experimental results shown that the permanent mold coating performed good properties on magnesium alloys when the optimized ratio of magnesia powder and diatomite was 6: 4, and the integrated property is very excellent when the coating was prepared with 2 percent of sodium bentonite, 0.4 percent of CMC, 7 percent of sodium hexametaphosphate, and 7 percent of sodium silicate. The excellent performance has also been proved by actual casting test.

A Principle and Winding Design of Consequent-Pole Bearingless Motors

NASA Astrophysics Data System (ADS)

Takenaga, Tomohiro; Kubota, Yutaka; Chiba, Akira; Fukao, Tadashi

Recently, bearingless motors have been developed to enhance motor drive systems with magnetic suspension. Several types of motors have been proposed as bearingless motors, such as induction, surface mounted permanent magnet, inset permanent magnet, interior permanent magnet, buried permanent magnet, homopolar, hybrid, and switched reluctance bearingless motors. Permanent magnet bearingless motors have been attracting more interests in these years because of the high efficiency. In this paper, a consequent-pole bearingless motor is proposed. A rotor has buried permanent magnets, of which polarities are like. The radial force of a consequent-pole bearingless motor is generated by dc current. Thus, rotational angular position is not needed in a magnetic suspension controller. Radial force variations caused by a rotor rotation are minimized by improving arrangement of stator suspension conductors. A prototype bearingless motor and its controller are built. In experiment, principles of magnetic suspension in the proposed consequent-pole bearingless drive are confirmed.

Permanent-magnet multipole with adjustable strength

DOEpatents

Halbach, K.

1982-09-20

Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling there between. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

Permanent magnet multipole with adjustable strength

DOEpatents

Halbach, Klaus

1985-01-01

Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

Etiological evaluation of primary congenital hypothyroidism cases

PubMed Central

Bezen, Diğdem; Dilek, Emine; Torun, Neşe; Tütüncüler, Filiz

2017-01-01

Aim Primary congenital hypothyroidism is frequently seen endocrine disorder and one of the preventable cause of mental retardation. Aim of study was to evaluate the frequency of permanent/transient hypothyrodism, and to detect underlying reason to identfy any marker which carries potential to discriminate permanent/transient form. Material and Methods Forty eight cases older than 3 years of age, diagnosed as primary congenital hypothyroidism and started thyroxin therapy in newborn-period, and followed up between January 2007–June 2013 were included in the study. Thyroid hormon levels were evaluated and thyroid ultrasonography was performed in cases who are at the end of their 3 years of age, after 6 weeks of thyroxine free period. Thyroid sintigraphy was performed if serum thyroid-stimulating hormone was high (≥ 5 mIU/mL) and perchlorate discharge test was performed if uptake was normal or increased on sintigraphy. Cases with thyroid-stimulating hormone levels ≥ 5 mIU/mL were defined as permanent primary congenital hypothyroidism group and as transient primary congenital hypothyroidism group with normal thyroid hormones during 6 months. Results The mean age was 3.8±0.7 years. Mean diagnosis age was 16.6±6.5 days and 14 cases (29.2%) were diagnosed by screening program of Ministry of Health. There were 23 cases (14F, 9M) in permanent primary congenital hypothyroidism group and 12 (52.2%) of them were dysgenesis (8 hypoplasia, 4 ectopia), and 11 (47.8%) dyshormonogenesis. In transient primary congenital hypothyroidism group, there were 25 cases (17M, 8F). The mean thyroid-stimulating hormone levels at diagnosis were similar in two groups. The mean thyroxin dose in permanent primary congenital hypothyroidism group was significantly higher than transient group at the time of thyroxin cessation (2.1±0.7, 1.5±0.5 mg/kg/d, respectively, p=0.004). Thyroxin dose ≥1.6 mcg/kg/d was 72% sensitive and 69.6% specific for predicting permenant primary congenital hypothyroidism. Conclusions Transient primary congenital hypothyroidism is more frequent than expected and found often in males in the primary congenital hypothyroidism cases, started thyroxin therapy in neonatal period. While fT4, thyroid-stimulating hormone, Tg levels at diagnosis do not predict transient/permenant primary congenital hypothyroidism, thyroxin dose before the therapy cessation at the age of 3 may make the distinction between transient/permenant primary congenital hypothyroidism. PMID:28747839

Memory and representation in young children with Down syndrome: Exploring deferred imitation and object permanence

PubMed Central

RAST, MECHTHILD; MELTZOFF, ANDREW N.

2013-01-01

Deferred imitation and object permanence (OP) were tested in 48 young children with Down syndrome (DS), ranging from 20 to 43 months of age. Deferred imitation and high-level OP (invisible displacements) have long been held to be synchronous developments during sensory-motor “Stage 6” (18–24 months of age in unimpaired children). The results of the current study demonstrate deferred imitation in young children with DS, showing they can learn novel behaviors from observation and retain multiple models in memory. This is the first demonstration of deferred imitation in young children with DS. The average OP level passed in this sample was A-not-B, a task passed at 8–12 months of age in normally developing infants. Analyses showed that individual children who failed high-level OP (invisible displacements) could still perform deferred imitation. This indicates that deferred imitation and OP invisible displacements are not synchronous developments in children with DS. This asynchrony is compatible with new data from unimpaired children suggesting that deferred imitation and high-level OP entail separate and distinctive kinds of memory and representation. PMID:25530676

Magnetic core shell nanoparticles trapping in a microdevice generating high magnetic gradient.

PubMed

Teste, Bruno; Malloggi, Florent; Gassner, Anne-Laure; Georgelin, Thomas; Siaugue, Jean-Michel; Varenne, Anne; Girault, Hubert; Descroix, Stéphanie

2011-03-07

Magnetic core shell nanoparticles (MCSNPs) 30 nm diameter with a magnetic weight of 10% are usually much too small to be trapped in microfluidic systems using classical external magnets. Here, a simple microchip for efficient MCSNPs trapping and release is presented. It comprises a bed of micrometric iron beads (6-8 μm diameter) packed in a microchannel against a physical restriction and presenting a low dead volume of 0.8 nL. These beads of high magnetic permeability are used to focus magnetic field lines from an external permanent magnet and generate local high magnetic gradients. The nanoparticles magnetic trap has been characterised both by numerical simulations and fluorescent MCSNPs imaging. Numerical simulations have been performed to map both the magnetic flux density and the magnetic force, and showed that MCSNPs are preferentially trapped at the iron bead magnetic poles where the magnetic force is increased by 3 orders of magnitude. The trapping efficiency was experimentally determined using fluorescent MCSNPs for different flow rates, different iron beads and permanent magnet positions. At a flow rate of 100 μL h(-1), the nanoparticles trapping/release can be achieved within 20 s with a preconcentration factor of 4000.

Comprehensive comparison of the levitation performance of bulk YBaCuO arrays above two different types of magnetic guideways

NASA Astrophysics Data System (ADS)

Deng, Zigang; Qian, Nan; Che, Tong; Jin, Liwei; Si, Shuaishuai; Zhang, Ya; Zheng, Jun

2016-12-01

The permanent magnet guideway (PMG) is an important part of high temperature superconducting (HTS) maglev systems. So far, two types of PMG, the normal PMG and Halbach-type PMG, are widely applied in present maglev transportation systems. In this paper, the levitation performance of high temperature superconductor bulks above the two PMGs was synthetically compared. Both static levitation performance and dynamic response characteristics were investigated. Benefiting from the reasonable magnetic field distribution, the Halbach-type PMG is able to gain larger levitation force, greater levitation force decay during the same relaxation time, bigger resonance frequency and dynamic stiffness for the bulk superconductor levitation unit compared with the normal PMG. Another finding is that the Halbach-type PMG is not sensitive to the levitation performance of the bulk levitation unit with different arrays. These results are helpful for the practical application of HTS maglev systems.

Complementary analyses of hollow cylindrical unioriented permanent magnet (HCM) with high permeability external layer

NASA Astrophysics Data System (ADS)

Lobo, Carlos M. S.; Tosin, Giancarlo; Baader, Johann E.; Colnago, Luiz A.

2017-10-01

In this article, several studies based on analytical expressions and computational simulations on Hollow Cylindrical Magnets with an external soft ferromagnetic material (HCM magnets) are presented. Electromagnetic configurations, as well as permanent-magnet-based structures, are studied in terms of magnetic field strength and homogeneity. Permanent-magnet-based structures are further analyzed in terms of the anisotropy of the magnetic permeability. It was found that the HCM magnets produce a highly homogeneous magnetic field as long as the magnetic material is isotropic. The dependency of the magnetic field strength and homogeneity in terms of the anisotropy of the magnetic permeability is also explored here. These magnets can potentially be used in medium-resolution NMR spectrometers and high-field NMR spectrometers.

Net shape processing of alnico magnets by additive manufacturing

DOE PAGES

White, Emma Marie Hamilton; Kassen, Aaron Gregory; Simsek, Emrah; ...

2017-06-07

Alternatives to rare earth permanent magnets, such as alnico, will reduce supply instability, increase sustainability, and could decrease the cost of permanent magnets, especially for high temperature applications, such as traction drive motors. Alnico magnets with moderate coercivity, high remanence, and relatively high energy product are conventionally processed by directional solidification and (significant) final machining, contributing to increased costs and additional material waste. Additive manufacturing (AM) is developing as a cost effective method to build net-shape three-dimensional parts with minimal final machining and properties comparable to wrought parts. This work describes initial studies of net-shape fabrication of alnico magnets bymore » AM using a laser engineered net shaping (LENS) system. High pressure gas atomized (HPGA) pre-alloyed powders of two different modified alnico “8” compositions, with high purity and sphericity, were built into cylinders using the LENS process, followed by heat treatment. The magnetic properties showed improvement over their cast and sintered counterparts. The resulting alnico permanent magnets were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and hysteresisgraph measurements. Furthermore, these results display the potential for net-shape processing of alnico permanent magnets for use in next generation traction drive motors and other applications requiring high temperatures and/or complex engineered part geometries.« less

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

White, Emma Marie Hamilton; Kassen, Aaron Gregory; Simsek, Emrah

Alternatives to rare earth permanent magnets, such as alnico, will reduce supply instability, increase sustainability, and could decrease the cost of permanent magnets, especially for high temperature applications, such as traction drive motors. Alnico magnets with moderate coercivity, high remanence, and relatively high energy product are conventionally processed by directional solidification and (significant) final machining, contributing to increased costs and additional material waste. Additive manufacturing (AM) is developing as a cost effective method to build net-shape three-dimensional parts with minimal final machining and properties comparable to wrought parts. This work describes initial studies of net-shape fabrication of alnico magnets bymore » AM using a laser engineered net shaping (LENS) system. High pressure gas atomized (HPGA) pre-alloyed powders of two different modified alnico “8” compositions, with high purity and sphericity, were built into cylinders using the LENS process, followed by heat treatment. The magnetic properties showed improvement over their cast and sintered counterparts. The resulting alnico permanent magnets were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and hysteresisgraph measurements. Furthermore, these results display the potential for net-shape processing of alnico permanent magnets for use in next generation traction drive motors and other applications requiring high temperatures and/or complex engineered part geometries.« less

Current status and recent topics of rare-earth permanent magnets

NASA Astrophysics Data System (ADS)

Sugimoto, S.

2011-02-01

After the development of Nd-Fe-B magnets, rare-earth magnets are now essential components in many fields of technology, because of their ability to provide a strong magnetic flux. There are two, well-established techniques for the manufacture of rare earth magnets: powder metallurgy is used to obtain high-performance, anisotropic, fully dense magnet bodies; and the melt-spinning or HDDR (hydrogenation, disproportionation, desorption and recombination) process is widely used to produce magnet powders for bonded magnets. In the industry of sintered Nd-Fe-B magnets, the total amount of production has increased and their dominant application has been changed to motors. In particular, their use for motors in hybrid cars is one of the most attractive applications. Bonded magnets have also been used for small motors, and the studies of nanocomposite and Sm-Fe-N magnets have become widespread. This paper reviews the current status and future trend in the research of permanent magnets.

A model predictive current control of flux-switching permanent magnet machines for torque ripple minimization

NASA Astrophysics Data System (ADS)

Huang, Wentao; Hua, Wei; Yu, Feng

2017-05-01

Due to high airgap flux density generated by magnets and the special double salient structure, the cogging torque of the flux-switching permanent magnet (FSPM) machine is considerable, which limits the further applications. Based on the model predictive current control (MPCC) and the compensation control theory, a compensating-current MPCC (CC-MPCC) scheme is proposed and implemented to counteract the dominated components in cogging torque of an existing three-phase 12/10 FSPM prototyped machine, and thus to alleviate the influence of the cogging torque and improve the smoothness of electromagnetic torque as well as speed, where a comprehensive cost function is designed to evaluate the switching states. The simulated results indicate that the proposed CC-MPCC scheme can suppress the torque ripple significantly and offer satisfactory dynamic performances by comparisons with the conventional MPCC strategy. Finally, experimental results validate both the theoretical and simulated predictions.

A new search for the permanent electric dipole moment of 129Xe at FRM-II

NASA Astrophysics Data System (ADS)

Sachdeva, N.; Chupp, T.; Degenkolb, S.; Fierlinger, P.; Kraegloh, E.; Kuchler, F.; Lins, T.; Meinel, J.; Niessen, B.; Stuiber, S.; Terrano, W. A.; Burghoff, M.; Fan, I.; Kilian, W.; Grüneberg, S.; Schnabel, A.; Seifert, F.; Stollfuss, D.; Trahms, L.; Voight, J.; Babcock, E.; Salhi, Z.; Huneau, J.; Singh, J.

2017-01-01

CP-violating sources in beyond-the-standard-model physics, necessary to explain baryon asymmetry, give rise to permanent electric dipole moments (EDMs). Precise EDM measurements of the neutron, electron, paramagnetic and diamagnetic atoms constrain CP-violating parameters. The previous limit for the 129Xe EDM is 6 ×10-27 e . cm (95 % CL). The HeXeEDM experiment at FRM-II (Munich Research Reactor) utilizes an ultralow magnetic field in a high-performance magnetically shielded room and 3He comagnetometer to improve the limit by up to three orders of magnitude. In the experiment, hyperpolarized 3He and 129Xe precession signals are detected with a SQUID magnetometer array in the presence of applied electric and magnetic fields. Recent progress will be presented. This work is supported US Department of Energy Grant No. DE FG02 04 ER41331.

[Examination of fitness to drive].

PubMed

Römer, Konstanze D

2008-07-01

Driving a car in public traffic requires a high performance that is often underestimated owing to daily habit. Fitness to drive can be impaired temporary or permanently because of taking substances declining the performance and because of various somatic diseases and psychic disorders. To check the fitness to drive is the responsibility of medical examination in terms of road traffic. This is supposed to be an individual examination corresponding to acknowledged guidelines by an experienced expert in order to keep away dangerous drivers from road traffic but not to reduce excessively the personal freedom of those drivers, who do not endanger road traffic considerably.

Impact of parent-related factors on dental caries in the permanent dentition of 6-12-year-old children: A systematic review.

PubMed

Kumar, Santhosh; Tadakamadla, Jyothi; Kroon, Jeroen; Johnson, Newell W

2016-03-01

To synthesise data from the literature on the effects of various parent-related characteristics (socio-demographic, behavioural and family environment) on dental caries in the permanent dentition of children. Available studies in which the effects of parent-related characteristics on dental caries experience in the permanent dentition of children aged 6-12 years were evaluated. PubMed, Medline via OVID and CINAHL Plus via EBSCO, restricted to scientific articles, were searched in April 2015. English language and time filters (articles published from 2000) were used. A total of 4162 titles were retrieved, of which 2578 remained after duplicates were removed. After review of titles and their abstracts by two independent reviewers, 114 articles were considered relevant for full text review. Of these, 48 were considered for final inclusion. Data extraction was performed by two authors using piloted data extraction sheets. Most of the literature on determinants of dental caries has been limited to socio-economic and behavioural aspects: we found few studies evaluating the effects of family environment and parental oral hygiene behaviour. Children belonging to lower socio-economic classes experienced more caries. In more than half the studies, children of highly educated, professional and high income parents were at lower risk for dental caries. There were conflicting results from studies on the effect of variables related to family environment, parents' oral hygiene behaviour and parent's disease status on dental caries in their children. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamic response characteristics of high temperature superconducting maglev systems: Comparison between Halbach-type and normal permanent magnet guideways

NASA Astrophysics Data System (ADS)

Wang, B.; Zheng, J.; Che, T.; Zheng, B. T.; Si, S. S.; Deng, Z. G.

2015-12-01

The permanent magnet guideway (PMG) is very important for the performance of the high temperature superconducting (HTS) system in terms of electromagnetic force and operational stability. The dynamic response characteristics of a HTS maglev model levitating on two types of PMG, which are the normal PMG with iron flux concentration and Halbach-type PMG, were investigated by experiments. The dynamic signals for different field-cooling heights (FCHs) and loading/unloading processes were acquired and analyzed by a vibration analyzer and laser displacement sensors. The resonant frequency, stiffness and levitation height of the model were discussed. It was found that the maglev model on the Halbach-type PMG has higher resonant frequency and higher vertical stiffness compared with the normal PMG. However, the low lateral stiffness of the model on the Halbach-type PMG indicates poor lateral stability. Besides, the Halbach-type PMG has better loading capacity than the normal PMG. These results are helpful to design a suitable PMG for the HTS system in practical applications.

A novel type of rim thrust motor with Halbach array permanent magnet rotor

NASA Astrophysics Data System (ADS)

Cao, Haichuan; Chen, Weihu

2018-05-01

The Rim-driven Thruster (RDT) is a new type of marine electric thruster proposed in recent years. In this paper, the author proposed a new type of permanent magnet synchronous rim thrust motor (RTM). The motor uses a Halbach array permanent magnet rotor, which can improve the torque density of the propulsion motor by utilizing the unilateral magnetic field of the Halbach array. In this paper, the electromagnetic properties of the motor were measured and compared with that of the ordinary magnetic pole motor through numerical analysis. The results show that at the same power, the new motor can significantly reduce the thickness of the rotor's permanent magnet and yoke core, and has obvious advantages in power density, moment of inertia, dynamic performance, and cost.

Investigation of a 7-pole/6-slot Halbach-magnetized permanent-magnet linear alternator used for free-piston stirling engines

NASA Astrophysics Data System (ADS)

Zheng, Ping; Tong, Chengde; Zhao, Jing; Yu, Bin; Li, Lin; Bai, Jingang; Zhang, Lu

2012-04-01

This paper investigates a 7-pole/6-slot Halbach-magnetized permanent-magnet linear alternator used for free piston Stirling engines (FPSEs). Taking the advantages of Halbach array, a 1 kW prototype alternator is designed. Considering the rms value of electromotive force (EMF) and harmonic distortion, the optimal length ratio of the axial- and radial-magnetized permanent magnets and thicknesses of the permanent magnets are optimized by 2D finite element method. The alternator detent force, which is an important factor for smooth operation of FPSEs, is studied by optimizing slot tip and end tooth. The load and thermal performances of the final design are simulated. A prototype alternator was designed, built and tested. Experimental data indicated satisfactory design.

Incidence of permanent hypocalcaemia after total thyroidectomy with or without central neck dissection for thyroid carcinoma: a nationwide claim study.

PubMed

Seo, Gi Hyeon; Chai, Young Jun; Choi, Hyung Jin; Lee, Kyu Eun

2016-09-01

Permanent hypocalcaemia is the most common and serious complication after total thyroidectomy (TT). This study examined the impact of central neck dissection (CND) and institutional volume on rates of permanent hypocalcaemia by analysing data held in the nationwide claim database of South Korea. Data from patients who underwent TT due to thyroid carcinoma from 2007-2013 were obtained from the Health Insurance Review and Assessment Service database. Of these, patients prescribed more than 1000 mg of elemental calcium for more than 288 days during the first 360 days postsurgery were defined as having permanent hypocalcaemia. In total, 192 333 patients (32 988 male and 159 345 female) were eligible for analysis. Of these, 52 707 (27·4%) underwent TT alone and 139 626 (72·6%) underwent TT plus CND. The incidence of permanent hypocalcaemia was greater in the TT plus CND group than in the TT alone group (5·4% vs 4·6%, P < 0·001). The age- and sex-adjusted risk for permanent hypocalcaemia in the TT plus CND group was 1·20 (P < 0·001). CND did not raise the rates of permanent hypocalcaemia in institutes with a low volume of annual cases (<200), whereas permanent hypocalcaemia was more common in the TT plus CND group than in the TT alone group (3·5% vs 2·9%, P = 0·002) in institutes with a large volume of annual cases (≥800). TT plus CND was associated with a greater risk of permanent hypocalcaemia than TT alone. Surgeons should consider the risk of permanent hypocalcaemia when deciding whether to perform CND. © 2016 John Wiley & Sons Ltd.

Design of spoke type motor and magnetizer for improving efficiency based rare-earth-free permanent-magnet motor

NASA Astrophysics Data System (ADS)

Kim, Young Hyun; Cheon, Byung Chul; Lee, Jung Ho

2018-05-01

This study proposes criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration. The optimal design of the stator and rotor can be enhanced using both a response surface method and finite element method. In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor. Finally, this study verifies that the proposed motor can efficiently replace interior permanent magnet synchronous motor in many industries.

Prevalence of dental anomalies in the permanent dentition of children with Down syndrome.

PubMed

Sekerci, Ahmet Ercan; Cantekin, Kenan; Aydinbelge, Mustafa; Ucar, Faruk İzzet

2014-01-01

The purpose of this study was to evaluate the prevalence of various congenital dental anomalies in the permanent dentition of Turkish children with Down syndrome. The sample consisted of 216 diagnostic records of children diagnosed with Down syndrome. All subjects had a clinical examination as well as radiographs and photographs taken. Anomalies in the permanent dentition were documented. There was a high incidence of dental anomalies, the most frequent being taurodontism (81 percent), rotation (28 percent), hypodontia (26 percent), tooth impaction (18 percent), ectopic eruption (14 percent), microdontia (13 percent), and hyperdontia (9 percent). Differences in prevalence of congenitally missing teeth, structural anomalies, and positional anomalies reached a statistically significant level regarding gender (P<.05). Turkish children with Down syndrome presented a high incidence of anomalies affecting the permanent dentition, and, in most cases, individuals presented with more than one anomaly.

Risky Music Listening, Permanent Tinnitus and Depression, Anxiety, Thoughts about Suicide and Adverse General Health

PubMed Central

Vogel, Ineke; van de Looij-Jansen, Petra M.; Mieloo, Cathelijne L.; Burdorf, Alex; de Waart, Frouwkje

2014-01-01

Objective To estimate the extent to which exposure to music through earphones or headphones with MP3 players or at discotheques and pop/rock concerts exceeded current occupational safety standards for noise exposure, to examine the extent to which temporary and permanent hearing-related symptoms were reported, and to examine whether the experience of permanent symptoms was associated with adverse perceived general and mental health, symptoms of depression, and thoughts about suicide. Methods A total of 943 students in Dutch inner-city senior-secondary vocational schools completed questionnaires about their sociodemographics, music listening behaviors and health. Multiple logistic regression analyses were used to examine associations. Results About 60% exceeded safety standards for occupational noise exposure; about one third as a result of listening to MP3 players. About 10% of the participants experienced permanent hearing-related symptoms. Temporary hearing symptoms that occurred after using an MP3 player or going to a discotheque or pop/rock concert were associated with exposure to high-volume music. However, compared to participants not experiencing permanent hearing-related symptoms, those experiencing permanent symptoms were less often exposed to high volume music. Furthermore, they reported at least two times more often symptoms of depression, thoughts about suicide and adverse self-assessed general and mental health. Conclusions Risky music-listening behaviors continue up to at least the age of 25 years. Permanent hearing-related symptoms are associated with people’s health and wellbeing. Participants experiencing such symptoms appeared to have changed their behavior to be less risky. In order to induce behavior change before permanent and irreversible hearing-related symptoms occur, preventive measurements concerning hearing health are needed. PMID:24897078

Risky music listening, permanent tinnitus and depression, anxiety, thoughts about suicide and adverse general health.

PubMed

Vogel, Ineke; van de Looij-Jansen, Petra M; Mieloo, Cathelijne L; Burdorf, Alex; de Waart, Frouwkje

2014-01-01

To estimate the extent to which exposure to music through earphones or headphones with MP3 players or at discotheques and pop/rock concerts exceeded current occupational safety standards for noise exposure, to examine the extent to which temporary and permanent hearing-related symptoms were reported, and to examine whether the experience of permanent symptoms was associated with adverse perceived general and mental health, symptoms of depression, and thoughts about suicide. A total of 943 students in Dutch inner-city senior-secondary vocational schools completed questionnaires about their sociodemographics, music listening behaviors and health. Multiple logistic regression analyses were used to examine associations. About 60% exceeded safety standards for occupational noise exposure; about one third as a result of listening to MP3 players. About 10% of the participants experienced permanent hearing-related symptoms. Temporary hearing symptoms that occurred after using an MP3 player or going to a discotheque or pop/rock concert were associated with exposure to high-volume music. However, compared to participants not experiencing permanent hearing-related symptoms, those experiencing permanent symptoms were less often exposed to high volume music. Furthermore, they reported at least two times more often symptoms of depression, thoughts about suicide and adverse self-assessed general and mental health. Risky music-listening behaviors continue up to at least the age of 25 years. Permanent hearing-related symptoms are associated with people's health and wellbeing. Participants experiencing such symptoms appeared to have changed their behavior to be less risky. In order to induce behavior change before permanent and irreversible hearing-related symptoms occur, preventive measurements concerning hearing health are needed.

Rare earth elements and permanent magnets (invited)

NASA Astrophysics Data System (ADS)

Dent, Peter C.

2012-04-01

Rare earth (RE) magnets have become virtually indispensible in a wide variety of industries such as aerospace, automotive, electronics, medical, and military. RE elements are essential ingredients in these high performance magnets based on intermetallic compounds RECo5, RE2TM17 (TM: transition metal), and RE2TM14B. Rare earth magnets are known for their superior magnetic properties—high induction, and coercive force. These properties arise due to the extremely high magnetocrystalline anisotropy made possible by unique 3d-4f interactions between transition metals and rare earths. For more than 40 years, these magnets remain the number one choice in applications that require high magnetic fields in extreme operating conditions—high demagnetization forces and high temperature. EEC produces and specializes in RECo5 and RE2TM17 type sintered magnets. Samarium and gadolinium are key RE ingredients in the powder metallurgical magnet production processes which include melting, crushing, jet milling, pressing, sintering, and heat treating. The magnetic properties and applications of these magnets will be discussed. We will also briefly discuss the past, current, and future of the permanent magnet business. Currently, over 95% of all pure rare earth oxides are sourced from China, which currently controls the market. We will provide insights regarding current and potential new magnet technologies and designer choices, which may mitigate rare earth supply chain issues now and into the future.

Correlation between Mechanical Behavior and Actuator-type Performance of Ni-Ti-Pd High-temperature Shape Memory Alloys

NASA Technical Reports Server (NTRS)

Bigelow, Glen S.; Padula, Santo A., II; Garg, Anita; Noebe, Ronald D.

2007-01-01

High-temperature shape memory alloys in the NiTiPd system are being investigated as lower cost alternatives to NiTiPt alloys for use in compact solid-state actuators for the aerospace, automotive, and power generation industries. A range of ternary NiTiPd alloys containing 15 to 46 at.% Pd has been processed and actuator mimicking tests (thermal cycling under load) were used to measure transformation temperatures, work behavior, and dimensional stability. With increasing Pd content, the work output of the material decreased, while the amount of permanent strain resulting from each load-biased thermal cycle increased. Monotonic isothermal tension testing of the high-temperature austenite and low temperature martensite phases was used to partially explain these behaviors, where a mismatch in yield strength between the austenite and martensite phases was observed at high Pd levels. Moreover, to further understand the source of the permanent strain at lower Pd levels, strain recovery tests were conducted to determine the onset of plastic deformation in the martensite phase. Consequently, the work behavior and dimensional stability during thermal cycling under load of the various NiTiPd alloys is discussed in relation to the deformation behavior of the materials as revealed by the strain recovery and monotonic tension tests.

Correlation between mechanical behavior and actuator-type performance of Ni-Ti-Pd high-temperature shape memory alloys

NASA Astrophysics Data System (ADS)

Bigelow, Glen S.; Padula, Santo A., II; Garg, Anita; Noebe, Ronald D.

2007-04-01

High-temperature shape memory alloys in the NiTiPd system are being investigated as lower cost alternatives to NiTiPt alloys for use in compact solid-state actuators for the aerospace, automotive, and power generation industries. A range of ternary NiTiPd alloys containing 15 to 46 at.% Pd has been processed and actuator mimicking tests (thermal cycling under load) were used to measure transformation temperatures, work behavior, and dimensional stability. With increasing Pd content, the work output of the material decreased, while the amount of permanent strain resulting from each load-biased thermal cycle increased. Monotonic isothermal tension testing of the high-temperature austenite and low temperature martensite phases was used to partially explain these behaviors, where a mismatch in yield strength between the austenite and martensite phases was observed at high Pd levels. Moreover, to further understand the source of the permanent strain at lower Pd levels, strain recovery tests were conducted to determine the onset of plastic deformation in the martensite phase. Consequently, the work behavior and dimensional stability during thermal cycling under load of the various NiTiPd alloys is discussed in relation to the deformation behavior of the materials as revealed by the strain recovery and monotonic tension tests.

The diagnostic accuracy of a laser fluorescence device and digital radiography in detecting approximal caries lesions in posterior permanent teeth: an in vivo study.

PubMed

Menem, R; Barngkgei, I; Beiruti, N; Al Haffar, I; Joury, Easter

2017-04-01

The aim of this in vivo study was to test the diagnostic accuracy of a pen-type laser fluorescence (LFpen) device in detecting approximal caries lesions, in posterior permanent teeth, at the cavitation and non-cavitation thresholds, and compare it with that of digital bitewing radiography. Thirty patients (aged 18-37), who attended the Faculty of Dentistry at Damascus University for a dental examination, were consecutively screened. Ninety approximal surfaces of posterior permanent teeth without frank cavitations, enamel hypoplasia or restorations were selected and examined using the LFpen (DIAGNOdent pen) and digital bitewing radiography. The reference standard was the visual-tactile inspection, after performing temporary tooth separation, using orthodontic rubber rings, placed for 7 days. The status of included approximal surfaces was recorded as intact/sound, with white/brown spots or cavitated. One trained examiner performed all examinations. There were statistically significant differences in LFpen readings between the three types of approximal surface status (P < 0.001). The optimal cut-off values for detecting approximal caries lesions in posterior permanent teeth were >16 and 8 at the cavitation and non-cavitation thresholds respectively. The sensitivity, specificity and accuracy (measured by the area under the receiver-operating characteristic curve) were 100, 85 and 95 and 92, 90 and 95% at the cavitation and non-cavitation thresholds respectively. The intra-class correlation coefficient for intra-examiner reliability was 0.95. The diagnostic accuracy of the LFpen was significantly higher than that of digital bitewing radiography (P < 0.001). The LFpen's diagnostic performance was accurate and significantly better than digital bitewing radiography in detecting approximal caries lesions, in posterior permanent teeth.

Kinetics of corneal thermal shrinkage

NASA Astrophysics Data System (ADS)

Borja, David; Manns, Fabrice; Lee, William E.; Parel, Jean-Marie

2004-07-01

Purpose: The purpose of this study was to determine the effects of temperature and heating duration on the kinetics of thermal shrinkage in corneal strips using a custom-made shrinkage device. Methods: Thermal shrinkage was induced and measured in corneal strips under a constant load placed while bathed in 25% Dextran irrigation solution. A study was performed on 57 Florida Lions Eye Bank donated human cadaver eyes to determine the effect of temperature on the amount and rate of thermal shrinkage. Further experiments were performed on 20 human cadaver eyes to determine the effects of heating duration on permanent shrinkage. Data analysis was performed to determine the effects of temperature, heating duration, and age on the amount and kinetics of shrinkage. Results: Shrinkage consisted of two phases: a shrinkage phase during heating and a regression phase after heating. Permanent shrinkage increased with temperature and duration. The shrinkage and regression time constants followed Arrhenius type temperature dependence. The shrinkage time constants where calculated to be 67, 84, 121, 560 and 1112 (s) at 80, 75, 70, 65, and 60°C respectively. At 65°C the permanent shrinkage time constant was calculated to be 945s. Conclusion: These results show that shrinkage treatments need to raise the temperature of the tissue above 75°C for several seconds in order to prevent regression of the shrinkage effect immediately after treatment and to induce the maximum amount of permanent irreversible shrinkage.

Performance of a Permanent-Magnet Cylindrical Hall-Effect Thruster

NASA Technical Reports Server (NTRS)

Polzin, K. A.; Sooby, E. S.; Kimberlin, A. C.; Raites, Y.; Merino, E.; Fisch, N. J.

2009-01-01

The performance of a low-power cylindrical Hall thruster, which more readily lends itself to miniaturization and low-power operation than a conventional (annular) Hall thruster, was measured using a planar plasma probe and a thrust stand. The field in the cylindrical thruster was produced using permanent magnets, promising a power reduction over previous cylindrical thruster iterations that employed electromagnets to generate the required magnetic field topology. Two sets of ring-shaped permanent magnets are used, and two different field configurations can be produced by reorienting the poles of one magnet relative to the other. A plasma probe measuring ion flux in the plume is used to estimate the current utilization for the two magnetic topologies. The measurements indicate that electron transport is impeded much more effectively in one configuration, implying higher thrust efficiency. Thruster performance measurements on this configuration were obtained over a power range of 70-350 W and with the cathode orifice located at three different axial positions relative to the thruster exit plane. The thrust levels over this power range were 1.25-6.5 mN, with anode efficiencies and specific impulses spanning 4-21% and 400-1950 s, respectively. The anode efficiency of the permanent-magnet thruster compares favorable with the efficiency of the electromagnet thruster when the power consumed by the electromagnets is taken into account.

Microgeographic and temporal genetic variation in populations of the bluetongue virus vector Culicoides variipennis (Diptera: Ceratopogonidae).

PubMed

Tabachnick, W J

1992-05-01

Seven Colorado populations of the bluetongue virus vector Culicoides varipennis (Coquillett) were analyzed for genetic variation at 19-21 isozyme loci. Permanent populations, which overwinter as larvae, showed little temporal genetic change at 19 loci. PGD and MDH showed seasonal changes in gene frequencies, attributable to selection at two permanent populations. Two temporary populations showed low heterozygosity compared with permanent populations. Independent estimates of gene flow, calculated using FST and the private allele method, were Nm* = 2.15 and 6.95, respectively. Colorado C. variipennis permanent populations showed high levels of gene flow which prevented significant genetic differentiation due to genetic drift. Temporary populations showed significant gene frequency differences from nearby permanent populations due to the "founder effect" associated with chance colonization.

New Element Organic Frameworks Based on Sn, Sb, and Bi, with Permanent Porosity and High Catalytic Activity

PubMed Central

Fritsch, Julia; Rose, Marcus; Wollmann, Philipp; Böhlmann, Winfried; Kaskel, Stefan

2010-01-01

We present new element organic frameworks based on Sn, Sb and Bi atoms connected via organic linkers by element-carbon bonds. The open frameworks are characterized by specific surface areas (BET) of up to 445 m2 g-1 and a good stability under ambient conditions resulting from a highly hydrophobic inner surface. They show good performance as heterogeneous catalysts in the cyanosylilation of benzaldehyde as a test reaction. Due to their catalytic activity, this class of materials might be able to replace common homogeneous element-organic and often highly toxic catalysts especially in the food industry.

A tubular flux-switching permanent magnet machine

NASA Astrophysics Data System (ADS)

Wang, J.; Wang, W.; Clark, R.; Atallah, K.; Howe, D.

2008-04-01

The paper describes a novel tubular, three-phase permanent magnet brushless machine, which combines salient features from both switched reluctance and permanent magnet machine technologies. It has no end windings and zero net radial force and offers a high power density and peak force capability, as well as the potential for low manufacturing cost. It is, therefore, eminently suitable for a variety of applications, ranging from free-piston energy converters to active vehicle suspensions.

Prediction of Future High Caries Increments for Children in a School Dental Service and in Private Practice.

ERIC Educational Resources Information Center

Imfeld, Thomas N.; And Others

1995-01-01

A method for predicting high dental caries increments for children, based on previous research, is presented. Three clinical findings were identified as predictors: number of sound primary molars, number of discolored pits/fissures on first permanent molars, and number of buccal and lingual smooth surfaces of first permanent molars with white…

Prevalence of enamel defects in primary and permanent teeth in a group of schoolchildren from Granada (Spain).

PubMed

Robles, Maria-Jesús; Ruiz, Matilde; Bravo-Perez, Manuel; González, Encarnación; Peñalver, Maria-Angustias

2013-03-01

The purpose of this study was to determine and compare the prevalence and presentations of developmental defects of the enamel (DDE) in the primary and permanent dentitions of a group of healthy schoolchildren residing in Granada (Spain). A total of 1,414 healthy schoolchildren were examined using modified DDE criteria for recording enamel defects. The prevalence of DDE of any type was 40.2% in primary dentition and 52% in permanent dentition (p<0.033). Of the 31,820 primary and permanent teeth examined in the study, 699 (4.1%) primary and 1,232 (8.3%) permanent teeth had some form of DDE. Diffuse opacity was the most common type of DDE observed in primary teeth, and demarcated opacity in the permanent teeth. Enamel hypoplasia was the least prevalent defect in both dentition types. The study population showed a high prevalence of DDE in primary as well as in permanent dentition, reflecting the current increasing trend of this condition, which should be considered as a significant public health problem.

Search behavior in various breeds of adult dogs (Canis familiaris): object permanence and olfactory cues.

PubMed

Gagnon, S; Doré, F Y

1992-03-01

Human analog tests of object permanence were administered to various breeds of adult dogs (Canis familiaris). Experiment 1 showed that the performance of terriers, sporting, and working dogs did not differ. Dogs succeeded in solving invisible displacement problems, but performance was lower than in visible displacement tests. Familiarity with the task had some influence because invisible displacement tests were more successful if they were preceded by visible displacement tests. In Experiment 2, odor cues from the target object and the hiding screens were available or were masked. Results confirmed that success was lower in invisible than in visible displacement tests and that these problems were solved on the basis of representation of visual information rather than on the basis of olfactory cues or of local rule learning. Dogs are compared with other species that display Stage 6 object permanence.

Software Package on Integrated Nonlinear Dynamic Modeling and Field Oriented Control (FOC) of Permanent Magnet (PM) Motor for High Performance Electromechanical Actuators (EMAs)

DTIC Science & Technology

2011-01-01

Louis Chow, David Woodburn, Lei Zhou, Jared Bindl, Yang Hu, and Wendell Brokaw University of Central Florida JANUARY 2011 Interim Report...Magnet (PM) Motor % % Written in SI or MKS Unit System. % % Authors: % David Woodburn % Dr. Lei Zhou % Dr. Thomas X. Wu clear all...Initial phase winding resistance [ ohm ] id = 0; % Phase d current [A] iq = 0; % Phase q current [A] did_dt = 0

Complementary analyses of hollow cylindrical unioriented permanent magnet (HCM) with high permeability external layer.

PubMed

Lobo, Carlos M S; Tosin, Giancarlo; Baader, Johann E; Colnago, Luiz A

2017-10-01

In this article, several studies based on analytical expressions and computational simulations on Hollow Cylindrical Magnets with an external soft ferromagnetic material (HCM magnets) are presented. Electromagnetic configurations, as well as permanent-magnet-based structures, are studied in terms of magnetic field strength and homogeneity. Permanent-magnet-based structures are further analyzed in terms of the anisotropy of the magnetic permeability. It was found that the HCM magnets produce a highly homogeneous magnetic field as long as the magnetic material is isotropic. The dependency of the magnetic field strength and homogeneity in terms of the anisotropy of the magnetic permeability is also explored here. These magnets can potentially be used in medium-resolution NMR spectrometers and high-field NMR spectrometers. Copyright © 2017 Elsevier Inc. All rights reserved.

High Strength and Wear Resistant Aluminum Alloy for High Temperature Applications

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.; Chen, Po Shou

2003-01-01

Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent thermal growth stability, surface hardness and wear resistant properties.

Aluminum-fly ash metal matrix composites for automotive parts. [Reports for April 1 to June 30, 1999, and July 1 to September 30, 1999

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

Weiss, David; Purgert, Robert; Rhudy, Richard

1999-10-15

Some highlights are: (1) During this quarter's field trials, sand mold castings of parts and permanent mold tensile testing bars, K mold bars, and ingots were made from aluminum alloy-fly ash melts. (2) Another objective was met, i.e., to use class ''F'' type precipitator fly ash consisting of particle sizes less than 100 microns. It was possible to pour the composite melt into the sand mold through a filter. (3) Trials were run to determine the required amount of the wetting agent, magnesium, to ensure appropriate mixing of the aluminum alloy and fly ash. The magnesium content required to mixmore » ''F'' fly ash was much lower compared to that required to mix hybrid ''C-F'' fly ash in similar melts. Fly ash particles of less than 100 microns were mixed in aluminum melt. Large scale field trials were undertaken at Eck Industries with the goal of standardizing procedures for producing aluminum-fly ash composite melts and to analyze the structure and properties of the resulting material. Limited testing of tensile properties has been done on pressure die cast parts, and attempts are underway to improve the distribution of fly ash in both sand cast and pressure die cast samples. Eck Industries performed radiographic, heat treatment, and tensile tests on permanent mold cast tensile test bars. After fly ash mixing experiments, the Lanxide high speed-high shear mixer (originally designed for mixing Al-SiC melts) was employed in an attempt to avoid fly ash agglomeration. It led to demixing (instead of deagglomerating) of some fly ash. However, the permanent mold tensile bars poured after high shear mixing displayed good distribution of fly ash in castings. A modified impeller design is being considered for high speed-high shear mixing of aluminum-fly ash melts.« less

A combined experimental and finite element analysis method for the estimation of eddy-current loss in NdFeB magnets.

PubMed

Fratila, Radu; Benabou, Abdelkader; Tounzi, Abdelmounaïm; Mipo, Jean-Claude

2014-05-14

NdFeB permanent magnets (PMs) are widely used in high performance electrical machines, but their relatively high conductivity subjects them to eddy current losses that can lead to magnetization loss. The Finite Element (FE) method is generally used to quantify the eddy current loss of PMs, but it remains quite difficult to validate the accuracy of the results with complex devices. In this paper, an experimental test device is used in order to extract the eddy current losses that are then compared with those of a 3D FE model.

A new type of magnetic gimballed momentum wheel and its application to attitude control in space

NASA Astrophysics Data System (ADS)

Murakami, C.; Ohkami, Y.; Okamoto, O.; Nakajima, A.; Inoue, M.; Tsuchiya, J.; Yabu-uchi, K.; Akishita, S.; Kida, T.

A new type of magnetically suspended gimbal momentum wheel utilizing permanent magnets is described. The bearing was composed of four independent thrust actuators which control the rotor thrust position and gimbal angles cooperatively, so that the bearing comes to have a simple mechanism with high reliability and light weight. The high speed instability problem due to the internal damping was easily overcome by introducing anisotropic radial stiffness. A momentum flywheel with the 3-axis controlled magnetic bearing displays good performance for attitude control of satellite with biased momentum.

Antibiotic prophylaxis in permanent pacemaker implantation: a prospective randomised trial.

PubMed Central

Mounsey, J P; Griffith, M J; Tynan, M; Gould, F K; MacDermott, A F; Gold, R G; Bexton, R S

1994-01-01

BACKGROUND--Pacemaker pocket infection is a potentially serious problem after permanent pacemaker implantation. Antibiotic prophylaxis is commonly prescribed to reduce the incidence of this complication, but current trial evidence of its efficacy is conflicting. A large prospective randomised trial was therefore performed of antibiotic prophylaxis in permanent pacemaker implantation. The intention was firstly to determine whether antibiotic prophylaxis is efficacious in these patients and secondly to identify which patients are at the highest risk of infection. METHODS--A prospective randomised open trial of flucloxacillin (clindamycin if the patient was allergic to penicillin) v no antibiotic was performed in a cohort of patients undergoing first implantation of a permanent pacing system over a 17 month period. Intravenous antibiotics were started at the time of implantation and continued for 48 hours. The trial endpoint was a repeat operation for an infective complication. RESULTS--473 patients were entered into a randomised trial. 224 received antibiotic prophylaxis and 249 received no antibiotics. A further 183 patients were not randomised but were treated according to the operator's preference (64 antibiotics, 119 no antibiotics); these patients are included only in the analysis of predictors of infection. Patients were followed up for a mean (SD) of 19(5) months. Among the patients in the randomised group there were nine infections requiring a repeat operation, all in the group not receiving antibiotic (P = 0.003). In the total patient cohort there were 13 infections, all but one in the non-antibiotic group (P = 0.006). Nine of the infections presented as erosion of the pulse generator or electrode, three as septicaemia secondary to Staphylococcus aureus, and one as a pocket abscess secondary to Staphylococcus epidermidis. Infections were significantly more common when the operator was inexperienced (< or = 100 previous patients), the operation was prolonged, or after a repeat operation for non-infective complications (principally lead displacement). Infection was not significantly more common in patients identified preoperatively as being at high risk (for example patients with diabetes mellitus, patients receiving long term steroid treatment), although there was a trend in this direction. CONCLUSIONS--Antibiotic prophylaxis significantly reduced the incidence of infective complications requiring a repeat operation after permanent pacemaker implantation. It is suggested that antibiotics should be used routinely. PMID:7833191

Restorative Procedures in Colonic Crohn Disease

PubMed Central

Martin, Sean T.; Vogel, Jon D.

2013-01-01

Surgical management for refractory Crohn colitis often involves creation of a temporary or permanent stoma. Traditionally, the procedure of choice has been a total proctocolectomy with permanent ileostomy. However, restorative procedures that help to avoid a permanent stoma are being used with more frequency. In this article, the authors will address these procedures, including colocolonic anastomosis, ileorectal anastomosis, ileal pouch rectal anastomosis, and ileal pouch anal anastomosis. Factors that may influence one's decision to perform these procedures, such as patient age and nutritional status, medical comorbidities, sphincter function, desire to avoid a permanent ostomy, and prior medical therapy, will be discussed. Functional outcomes regarding these procedures will also be described. One should keep in mind that surgery does not cure Crohn disease and that postoperative long-term management is essential in preventing progression or recurrence of disease. PMID:24436657

"Null-E" magnetic bearings

NASA Astrophysics Data System (ADS)

Filatov, Alexei Vladimirovich

2002-09-01

Using electromagnetic forces to suspend rotating objects (rotors) without mechanical contact is often an appealing technical solution. Magnetic suspensions are typically required to have adequate load capacity and stiffness, and low rotational loss. Other desired features include low price, high reliability and manufacturability. With recent advances in permanent-magnet materials, the required forces can often be obtained by simply using the interaction between permanent magnets. While a magnetic bearing based entirely on permanent magnets could be expected to be inexpensive, reliable and easy to manufacture, a fundamental physical principle known as Earnshaw's theorem maintains that this type of suspension cannot be statically stable. Therefore, some other physical mechanisms must be included. One such mechanism employs the interaction between a conductor and a nonuniform magnetic field in relative motion. Its advantages include simplicity, reliability, wide range of operating temperature and system autonomy (no external wiring and power supplies are required). The disadvantages of the earlier embodiments were high rotational loss, low stiffness and load capacity. This dissertation proposes a novel type of magnetic bearing stabilized by the field-conductor interaction. One of the advantages of this bearing is that no electric field, E, develops in the conductor during the rotor rotation when the system is in no-load equilibrium. Because of this we refer to it as the Null-E Bearing. Null-E Bearings have potential for lower rotational loss and higher load capacity and stiffness than other bearings utilizing the field-conductor interaction. Their performance is highly insensitive to manufacturing inaccuracies. The Null-E Bearing in its basic form can be augmented with supplementary electronics to improve its performance. Depending on the degree of the electronics involvement, a variety of magnetic bearings can be developed ranging from a completely passive to an active magnetic bearing of a novel type. This dissertation contains theoretical analysis of the Null-E Bearing operation, including derivation of the stability conditions and estimation of some of the rotational losses. The validity of the theoretical conclusions has been demonstrated by building and testing a prototype in which non-contact suspension of a 3.2-kg rotor is achieved at spin speeds above 18 Hz.

Theoretical validation for changing magnetic fields of systems of permanent magnets of drum separators

NASA Astrophysics Data System (ADS)

Lozovaya, S. Y.; Lozovoy, N. M.; Okunev, A. N.

2018-03-01

This article is devoted to the theoretical validation of the change in magnetic fields created by the permanent magnet systems of the drum separators. In the article, using the example of a magnetic separator for enrichment of highly magnetic ores, the method of analytical calculation of the magnetic fields of systems of permanent magnets based on the Biot-Savart-Laplace law, the equivalent solenoid method, and the superposition principle of fields is considered.

Growth anisotropy effect of bulk high temperature superconductors on the levitation performance in the applied magnetic field

NASA Astrophysics Data System (ADS)

Zheng, J.; Liao, X. L.; Jing, H. L.; Deng, Z. G.; Yen, F.; Wang, S. Y.; Wang, J. S.

2013-10-01

Growth anisotropies of bulk high temperature superconductors (HTSCs) fabricated by a top-seeded melt texture growth process, that is, different pinning effect in the growth sectors (GSs) and growth sector boundaries (GSBs), possess effect on the macro flux trapping and levitation performance of bulk HTSCs. Previous work (Physics Procedia, 36 (2012) 1043) has found that the bulk HTSC array with aligned GSB pattern (AGSBP) exhibits better capability for levitation and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP). In this paper, we further examine this growth anisotropy effect on the maglev performance of a double-layer bulk HTSC. In contrast to reported trapped flux cases (Supercond. Sci. Technol. 19 (2006) S466), the two superposed bulk HTSCs with same AGSBP with PMG are found to show better maglev performance. These series of results are helpful and support a new way for the performance optimization of present HTS maglev systems.

30 CFR 828.1 - Scope.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.1 Scope. This part sets forth special environmental protection performance, reclamation and design standards for in situ processing activities. [44 FR 15455, Mar. 13, 1979] ...

30 CFR 828.1 - Scope.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.1 Scope. This part sets forth special environmental protection performance, reclamation and design standards for in situ processing activities. [44 FR 15455, Mar. 13, 1979] ...

30 CFR 828.1 - Scope.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.1 Scope. This part sets forth special environmental protection performance, reclamation and design standards for in situ processing activities. [44 FR 15455, Mar. 13, 1979] ...

30 CFR 828.1 - Scope.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-IN SITU PROCESSING § 828.1 Scope. This part sets forth special environmental protection performance, reclamation and design standards for in situ processing activities. [44 FR 15455, Mar. 13, 1979] ...

Parastomal hernia mesh repair, variant of surgical technique without stoma relocation.

PubMed

Guriţă, P; Popa, R; Bălălău, B; Scăunaşu, R

2012-06-12

Due to the improvement of prognosis through adjuvant therapy, the life expectancy of neoplasia patients is continuously increasing, which, in conjunction with the progressive occurrence of parastomal hernias during the disease evolution, explains the growing number of reported parastomal hernias affecting patients with permanent colostomy. Conventional techniques of local repair are inappropriate considering the high recurrence rate, and the decision of stoma relocation depends on the associated pathology, which may counter-indicate general anesthesia, and on previous surgical interventions that are usually followed by a dense peritoneal adhesion syndrome. The purpose of this article is to make known a variant of alloplastic technique, without translocation, with a low degree of invasiveness, which can be performed successfully under spinal anesthesia, followed by a reduced period of hospitalization. The study group consisted of 6 patients with permanent left iliac anus who underwent these interventions one to three years prior to the occurrence of parastomal hernia. Patients were followed at 1 year and 2 years postoperatively and the results were favorable, with no recurrence and improved quality of life through proper prosthesis of the stoma. We suggest that this technique variation is applied to small and medium parastomal hernias, in case of patients with permanent left iliac anus, with the declared intent of minimal invasiveness.

Parastomal hernia mesh repair, variant of surgical technique without stoma relocation

PubMed Central

Guriţă, P; Popa, R; Bălălău, B; Scăunaşu, R

2012-01-01

Rationale:Due to the improvement of prognosis through adjuvant therapy, the life expectancy of neoplasia patients is continuously increasing, which, in conjunction with the progressive occurrence of parastomal hernias during the disease evolution, explains the growing number of reported parastomal hernias affecting patients with permanent colostomy. Conventional techniques of local repair are inappropriate considering the high recurrence rate, and the decision of stoma relocation depends on the associated pathology, which may counter-indicate general anesthesia, and on previous surgical interventions that are usually followed by a dense peritoneal adhesion syndrome . Objective:The purpose of this article is to make known a variant of alloplastic technique, without translocation, with a low degree of invasiveness, which can be performed successfully under spinal anesthesia, followed by a reduced period of hospitalization. Methods and Results:The study group consisted of 6 patients with permanent left iliac anus who underwent these interventions one to three years prior to the occurrence of parastomal hernia. Patients were followed at 1 year and 2 years postoperatively and the results were favorable, with no recurrence and improved quality of life through proper prosthesis of the stoma Discussion:We suggest that this technique variation is applied to small and medium parastomal hernias, in case of patients with permanent left iliac anus, with the declared intent of minimal invasiveness. PMID:22802882

Performance of improved magnetostrictive vibrational power generator, simple and high power output for practical applications

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

Ueno, Toshiyuki, E-mail: ueno@ec.t.kanazawa-u.ac.jp

2015-05-07

Vibration based power generation technology is utilized effectively in various fields. Author has invented novel vibrational power generation device using magnetostrictive material. The device is based on parallel beam structure consisting of a rod of iron-gallium alloy wound with coil and yoke accompanied with permanent magnet. When bending force is applied on the tip of the device, the magnetization inside the rod varies with induced stress due to the inverse magnetostrictive effect. In vibration, the time variation of the magnetization generates voltage on the wound coil. The magnetostrictive type is advantageous over conventional such using piezoelectric or moving magnet typesmore » in high efficiency and high robustness, and low electrical impedance. Here, author has established device configuration, simple, rigid, and high power output endurable for practical applications. In addition, the improved device is lower cost using less volume of Fe-Ga and permanent magnet compared to our conventional, and its assembly by soldering is easy and fast suitable for mass production. Average power of 3 mW/cm{sup 3} under resonant vibration of 212 Hz and 1.2 G was obtained in miniature prototype using Fe-Ga rod of 2 × 0.5× 7 mm{sup 3}. Furthermore, the damping effect was observed, which demonstrates high energy conversion of the generator.« less

When Dropping out Is Not a Permanent High School Outcome: Student Characteristics, Motivations, and Reenrollment Challenges

ERIC Educational Resources Information Center

Barrat, Vanessa X.; Berliner, Bethann; Fong, Anthony B.

2012-01-01

The customary perception is that students who drop out vanish from school enrollment rosters for good. This is an incomplete picture of the complex dropout story; dropping out is not necessarily a permanent high school outcome. Following the enrollment and course history of a district cohort of first-time 9th graders, this article documents the…

Electronically commutated dc motors for electric vehicles

NASA Technical Reports Server (NTRS)

Maslowski, E. A.

1981-01-01

A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

Nonuniform radiation damage in permanent magnet quadrupoles.

PubMed

Danly, C R; Merrill, F E; Barlow, D; Mariam, F G

2014-08-01

We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

Performance testing of asphalt concrete containing crumb rubber modifier and warm mix additives

NASA Astrophysics Data System (ADS)

Ikpugha, Omo John

Utilisation of scrap tire has been achieved through the production of crumb rubber modified binders and rubberised asphalt concrete. Terminal and field blended asphalt rubbers have been developed through the wet process to incorporate crumb rubber into the asphalt binder. Warm mix asphalt technologies have been developed to curb the problem associated with the processing and production of such crumb rubber modified binders. Also the lowered production and compaction temperatures associated with warm mix additives suggests the possibility of moisture retention in the mix, which can lead to moisture damage. Conventional moisture sensitivity tests have not effectively discriminated good and poor mixes, due to the difficulty of simulating field moisture damage mechanisms. This study was carried out to investigate performance properties of crumb rubber modified asphalt concrete, using commercial warm mix asphalt technology. Commonly utilised asphalt mixtures in North America such as dense graded and stone mastic asphalt were used in this study. Uniaxial Cyclic Compression Testing (UCCT) was used to measure permanent deformation at high temperatures. Indirect Tensile Testing (IDT) was used to investigate low temperature performance. Moisture Induced Sensitivity Testing (MiST) was proposed to be an effective method for detecting the susceptibility of asphalt mixtures to moisture damage, as it incorporates major field stripping mechanisms. Sonnewarm(TM), Sasobit(TM) and Evotherm(TM) additives improved the resistance to permanent deformation of dense graded mixes at a loading rate of 0.5 percent by weight of the binder. Polymer modified mixtures showed superior resistance to permanent deformation compared to asphalt rubber in all mix types. Rediset(TM) WMX improves low temperature properties of dense graded mixes at 0.5 percent loading on the asphalt cement. Rediset LQ and Rediset WMX showed good anti stripping properties at 0.5 percent loading on the asphalt cement. The American Association of State Highway and Transportation Official's Mechanistic-Empirical Pavement Design Guide (AASHTO MEPDG) software was used to predict long term low temperature performance of the mixtures in various areas of Ontario. Sasobit, Rediset LQ and Rediset WMX gave good 15 years prediction with stone mastic asphalt mixtures but the performance of dense graded mixtures was less satisfactory.

30 CFR 921.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 921.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 937.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 937.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 933.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 933.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 937.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 937.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 921.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 921.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 903.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-Coal exploration. 903.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, applies to any person who conducts coal exploration. ...

30 CFR 933.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 933.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 921.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 921.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 903.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-Coal exploration. 903.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, applies to any person who conducts coal exploration. ...

30 CFR 922.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 922.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 941.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 941.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 941.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 941.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 905.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-Coal exploration. 905.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 912.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 912.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 910.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 910.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 903.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-Coal exploration. 903.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, applies to any person who conducts coal exploration. ...

30 CFR 939.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 939.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 910.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 910.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 922.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 922.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 933.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 933.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 939.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 939.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 905.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-Coal exploration. 905.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 922.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 922.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 912.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 912.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 933.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 933.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 939.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 939.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 921.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 921.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 921.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 921.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 903.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-Coal exploration. 903.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, applies to any person who conducts coal exploration. ...

30 CFR 937.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 937.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 933.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 933.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 937.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 937.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 905.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-Coal exploration. 905.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 942.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-Coal exploration. 942.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 903.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-Coal exploration. 903.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, applies to any person who conducts coal exploration. ...

30 CFR 905.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-Coal exploration. 905.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 912.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 912.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 942.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-Coal exploration. 942.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 922.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 922.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 910.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 910.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 905.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-Coal exploration. 905.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 910.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 910.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 942.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-Coal exploration. 942.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 912.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 912.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 942.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-Coal exploration. 942.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 942.815 - Performance standards-Coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-Coal exploration. 942.815... Performance standards—Coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person who conducts coal exploration. ...

30 CFR 922.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 922.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 937.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 937.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 910.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 910.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 941.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 941.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 939.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 939.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 912.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 912.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 941.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 941.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 941.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 941.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

30 CFR 939.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 939.815... Performance standards—coal exploration. Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. ...

Advanced single permanent magnet axipolar ironless stator ac motor for electric passenger vehicles

NASA Technical Reports Server (NTRS)

Beauchamp, E. D.; Hadfield, J. R.; Wuertz, K. L.

1983-01-01

A program was conducted to design and develop an advanced-concept motor specifically created for propulsion of electric vehicles with increased range, reduced energy consumption, and reduced life-cycle costs in comparison with conventional systems. The motor developed is a brushless, dc, rare-earth cobalt, permanent magnet, axial air gap inductor machine that uses an ironless stator. Air cooling is inherent provided by the centrifugal-fan action of the rotor poles. An extensive design phase was conducted, which included analysis of the system performance versus the SAE J227a(D) driving cycle. A proof-of-principle model was developed and tested, and a functional model was developed and tested. Full generator-level testing was conducted on the functional model, recording electromagnetic, thermal, aerodynamic, and acoustic noise data. The machine demonstrated 20.3 kW output at 1466 rad/s and 160 dc. The novel ironless stator demonstated the capability to continuously operate at peak current. The projected system performance based on the use of a transistor inverter is 23.6 kW output power at 1466 rad/s and 83.3 percent efficiency. Design areas of concern regarding electric vehicle applications include the inherently high windage loss and rotor inertia.

Handheld magnetic probe with permanent magnet and Hall sensor for identifying sentinel lymph nodes in breast cancer patients.

PubMed

Sekino, Masaki; Kuwahata, Akihiro; Ookubo, Tetsu; Shiozawa, Mikio; Ohashi, Kaichi; Kaneko, Miki; Saito, Itsuro; Inoue, Yusuke; Ohsaki, Hiroyuki; Takei, Hiroyuki; Kusakabe, Moriaki

2018-01-19

The newly developed radioisotope-free technique based on magnetic nanoparticle detection using a magnetic probe is a promising method for sentinel lymph node biopsy. In this study, a novel handheld magnetic probe with a permanent magnet and magnetic sensor is developed to detect the sentinel lymph nodes in breast cancer patients. An outstanding feature of the probe is the precise positioning of the sensor at the magnetic null point of the magnet, leading to highly sensitive measurements unaffected by the strong ambient magnetic fields of the magnet. Numerical and experimental results show that the longitudinal detection length is approximately 10 mm, for 140 μg of iron. Clinical tests were performed, for the first time, using magnetic and blue dye tracers-without radioisotopes-in breast cancer patients to demonstrate the performance of the probe. The nodes were identified through transcutaneous and ex-vivo measurements, and the iron accumulation in the nodes was quantitatively revealed. These results show that the handheld magnetic probe is useful in sentinel lymph node biopsy and that magnetic techniques are widely being accepted as future standard methods in medical institutions lacking nuclear medicine facilities.

High-Temperature Shape Memory Polymers

NASA Technical Reports Server (NTRS)

Yoonessi, Mitra; Weiss, Robert A.

2012-01-01

physical conformation changes when exposed to an external stimulus, such as a change in temperature. Such materials have a permanent shape, but can be reshaped above a critical temperature and fixed into a temporary shape when cooled under stress to below the critical temperature. When reheated above the critical temperature (Tc, also sometimes called the triggering or switching temperature), the materials revert to the permanent shape. The current innovation involves a chemically treated (sulfonated, carboxylated, phosphonated, or other polar function group), high-temperature, semicrystalline thermoplastic poly(ether ether ketone) (Tg .140 C, Tm = 340 C) mix containing organometallic complexes (Zn++, Li+, or other metal, ammonium, or phosphonium salts), or high-temperature ionic liquids (e.g. hexafluorosilicate salt with 1-propyl-3- methyl imidazolium, Tm = 210 C) to form a network where dipolar or ionic interactions between the polymer and the low-molecular-weight or inorganic compound forms a complex that provides a physical crosslink. Hereafter, these compounds will be referred to as "additives". The polymer is semicrystalline, and the high-melt-point crystals provide a temporary crosslink that acts as a permanent crosslink just so long as the melting temperature is not exceeded. In this example case, the melting point is .340 C, and the shape memory critical temperature is between 150 and 250 C. PEEK is an engineering thermoplastic with a high Young fs modulus, nominally 3.6 GPa. An important aspect of the invention is the control of the PEEK functionalization (in this example, the sulfonation degree), and the thermal properties (i.e. melting point) of the additive, which determines the switching temperature. Because the compound is thermoplastic, it can be formed into the "permanent" shape by conventional plastics processing operations. In addition, the compound may be covalently cross - linked after forming the permanent shape by S-PEEK by applying ionizing radiation ( radiation, neutrons), or by chemical crosslinking to form a covalent permanent network. With respect to other shape memory polymers, this invention is novel in that it describes the use of a thermoplastic composition that can be thermally molded or solution-cast into complex "permanent" shapes, and then reheated or redissolved and recast from solution to prepare another shape. It is also unique in that the shape memory behavior is provided by a non-polymer additive.

Development of a High-speed Electromagnetic Repulsion Mechanism for High-voltage Vacuum Circuit Breakers

NASA Astrophysics Data System (ADS)

Tsukima, Mitsuru; Takeuchi, Toshie; Koyama, Kenichi; Yoshiyasu, Hajimu

This paper presents a design and testing of a new high-speed electromagnetic driving mechanism for a high-voltage vacuum circuit breaker (VCB). This mechanism is based on a high-speed electromagnetic repulsion and a permanent magnet spring (PMS). This PMS is introduced instead of the conventional disk spring due to its low spring energy and more suitable force characteristics for VCB application. The PMS has been optimally designed by the 3d non-linear finite-elements magnetic field analysis and investigated its internal friction and eddy-current effect. Furthermore, we calculated the dynamic of this mechanism coupling with the electromagnetic field and circuit analysis, in order to satisfy the operating characteristics—contact velocity, response time and so on, required for the high-speed VCB. A prototype VCB, which was built based on the above analysis shows sufficient operating performance. Finally, the short circuit interruption tests were carried out with this prototype breaker, and we have been able to verify its satisfying performance.

Design and analysis of tubular permanent magnet linear generator for small-scale wave energy converter

NASA Astrophysics Data System (ADS)

Kim, Jeong-Man; Koo, Min-Mo; Jeong, Jae-Hoon; Hong, Keyyong; Cho, Il-Hyoung; Choi, Jang-Young

2017-05-01

This paper reports the design and analysis of a tubular permanent magnet linear generator (TPMLG) for a small-scale wave-energy converter. The analytical field computation is performed by applying a magnetic vector potential and a 2-D analytical model to determine design parameters. Based on analytical solutions, parametric analysis is performed to meet the design specifications of a wave-energy converter (WEC). Then, 2-D FEA is employed to validate the analytical method. Finally, the experimental result confirms the predictions of the analytical and finite element analysis (FEA) methods under regular and irregular wave conditions.

Orthodontic Management with Traction and Asymmetric Extraction for Multiple Impacted Permanent Maxillary Teeth - A Case Report.

PubMed

Niu, Qiannan; Zhang, Liang; Dai, Juan; Li, Feifei; Feng, Xue

2016-01-01

Multiple impacted teeth are a rare eruption disturbance that increases the case complexity. In this article, we described a 13-year-old boy whose 5 permanent maxillary teeth were not erupted although their root formation was complete. The orthodontic treatment with traction and asymmetric extraction was performed to achieve a significantly improved functional and esthetic result.

Development of high-performing semiconducting polymers for organic electrochemical transistors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Nielsen, Christian

2016-11-01

The organic electrochemical transistor (OECT), capable of amplifying small electrical signals in an aqueous environment, is an ideal device to utilize in organic bioelectronic applications involving for example neural interfacing and diagnostics. Currently, most OECTs are fabricated with commercially available conducting poly(3,4-ethylenedioxythiophene)-based suspensions such as PEDOT:PSS and are therefore operated in depletion mode giving rise to devices that are permanently on with non-optimal operational voltage. With the aim to develop and utilize efficient accumulation mode OECT devices, we discuss here our recent results regarding the design, synthesis and performance of novel intrinsic semiconducting polymers. Covering key aspects such as ion and charge transport in the bulk semiconductor and operational voltage and stability of the materials and devices, we have elucidated important structure-property relationships. We illustrate the improvements this approach has afforded in the development of high performance accumulation mode OECT materials.

Quasi permanent superconducting magnet of very high field

NASA Technical Reports Server (NTRS)

Ren, Y.; Liu, J.; Weinstein, R.; Chen, I. G.; Parks, D.; Xu, J.; Obot, V.; Foster, C.

1993-01-01

We report on persistent field in a quasi-permanent magnet made of high temperature superconductor. The material has an average of 40 percent molar excess of Y, relative to Y1Ba2Cu3O7 and has been irradiated with high energy light ions at 200 MeV. The magnet, which traps 1.52 T at 77.3 K, traps nearly 4 T at 64.5 K. No evidence of giant flux jump or sample cracking was observed.

The Development of Permanent Medical Standards for Landing Craft Air Cushion (LCAC) Crew Personnel.

DTIC Science & Technology

1993-11-01

8217 ,-,. ,A.c,,, Jack Stuster, Ph.D. 2 Kevin Schneider3 ,.. Daniel Braun1 Dist 1 NAVAL HEALTH RESEARCH CENTER, SAN DIEGO, CA AL I 2 ANACAPA SCIENCES, INC...surf. 9. Operate craft while being towed. 10. Perlomr low speed waer -o-land transition In smooth water and obstades on beach. 11. PerformOf ur nderway...procedures, based on conditions and avable rionamaion 34. Respond and dmct crew response to a coision. 35. Pedorm high speed waer -to-aind tranition in

Altitude-Test-Chamber Investigation of the Endurance and Performance Characteristics of the J65-W-7 Engine at a Mach Number of 2.0

NASA Technical Reports Server (NTRS)

Biermann, A.E.; Braithwaite, Willis M.

1955-01-01

An investigation of the endurance characteristics, at high Mach number, of the J65-W-7 engine was made in an altitude chamber at the Lewis laboratory. The investigation was made to determine whether this engine can be operated at flight conditions of Mach 2 at 35,000-feet altitude (inlet temperature, 250 F) as a limited-service-life engine Failure of the seventh-stage aluminum compressor blades occurred in both engines tested and was attributed to insufficient strength of the blade fastenings at the elevated temperatures. For the conditions of these tests, the results showed that it is reasonable to expect 10 to 15 minutes of satisfactory engine operation before failure. The high temperatures and pressures imposed upon the compressor housing caused no permanent deformation. In general, the performance of the engines tested was only slightly affected by the high ram conditions of this investigation. There was no discernible depreciation of performance with time prior to failure.

A reaction cell for ambient pressure soft x-ray absorption spectroscopy

NASA Astrophysics Data System (ADS)

Castán-Guerrero, C.; Krizmancic, D.; Bonanni, V.; Edla, R.; Deluisa, A.; Salvador, F.; Rossi, G.; Panaccione, G.; Torelli, P.

2018-05-01

We present a new experimental setup for performing X-ray Absorption Spectroscopy (XAS) in the soft X-ray range at ambient pressure. The ambient pressure XAS setup is fully compatible with the ultra high vacuum environment of a synchrotron radiation spectroscopy beamline end station by means of ultrathin Si3N4 membranes acting as windows for the X-ray beam and seal of the atmospheric sample environment. The XAS detection is performed in total electron yield (TEY) mode by probing the drain current from the sample with a picoammeter. The high signal/noise ratio achievable in the TEY mode, combined with a continuous scanning of the X-ray energies, makes it possible recording XAS spectra in a few seconds. The first results show the performance of this setup to record fast XAS spectra from sample surfaces exposed at atmospheric pressure, even in the case of highly insulating samples. The use of a permanent magnet inside the reaction cell enables the measurement of X-ray magnetic circular dichroism at ambient pressure.

Metal Amorphous Nanocomposite Soft Magnetic Material-Enabled High Power Density, Rare Earth Free Rotational Machines [Metal Amorphous Nanocomposite (MANC) Soft Magnetic Material (SMM) Enabled High Power Density, Rare Earth Free Rotational Machines

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

Simizu, Satoru; Ohodnicki, Paul R.; McHenry, Michael E.

Metal amorphous nanocomposites (MANCs) are promising soft magnetic materials (SMMs) for power electronic applications offering low power loss at high frequency and maintaining a relatively high flux density. While applications in certain motor designs have been recently modeled, their widespread application awaits scaled manufacturing of MANC materials and proliferation of new higher speed motor designs. A hybrid motor design based on permanent magnets and doubly salient stator and rotor is reported here to develop a compact (a factor of 10 smaller than currently possible in Si steels), high-speed (>1 kHz, electrical), high-power (>2.5 kW) motor by incorporating low loss (<10more » W/kg at 1 kHz) MANCs such as recently reported Fe-Ni-based alloys. A feature of this motor design is flux focusing from the permanent magnet allowing use of lower energy permanent magnet chosen from among non-rare earth containing compositions and attractive due to constraints posed by rare earth criticality. A 2-D finite element analysis model reported here indicates that a 2.5 kW hybrid motor may be built with a permanent magnet with a 0.4 T remanence at a rotor speed of 6000 rpm. At a magnetic switching frequency of 1.4 kHz, the core loss may be limited to <3 W by selecting an appropriate MANC SMM. The projected efficiency exceeds 96% not including power loss in the controller. Under full load conditions, the flux density distributions for the SMM stay predominantly <1.3 T, the saturation magnetization of optimized FeNi-based MANC alloys. As a result, the maximum demagnetizing field in the permanent magnet is less than 2.2 × 10 5 A/m sustainable, for example, with a high-grade hard ferrite magnet.« less

Metal Amorphous Nanocomposite Soft Magnetic Material-Enabled High Power Density, Rare Earth Free Rotational Machines [Metal Amorphous Nanocomposite (MANC) Soft Magnetic Material (SMM) Enabled High Power Density, Rare Earth Free Rotational Machines

DOE PAGES

Simizu, Satoru; Ohodnicki, Paul R.; McHenry, Michael E.

2018-02-27

Metal amorphous nanocomposites (MANCs) are promising soft magnetic materials (SMMs) for power electronic applications offering low power loss at high frequency and maintaining a relatively high flux density. While applications in certain motor designs have been recently modeled, their widespread application awaits scaled manufacturing of MANC materials and proliferation of new higher speed motor designs. A hybrid motor design based on permanent magnets and doubly salient stator and rotor is reported here to develop a compact (a factor of 10 smaller than currently possible in Si steels), high-speed (>1 kHz, electrical), high-power (>2.5 kW) motor by incorporating low loss (<10more » W/kg at 1 kHz) MANCs such as recently reported Fe-Ni-based alloys. A feature of this motor design is flux focusing from the permanent magnet allowing use of lower energy permanent magnet chosen from among non-rare earth containing compositions and attractive due to constraints posed by rare earth criticality. A 2-D finite element analysis model reported here indicates that a 2.5 kW hybrid motor may be built with a permanent magnet with a 0.4 T remanence at a rotor speed of 6000 rpm. At a magnetic switching frequency of 1.4 kHz, the core loss may be limited to <3 W by selecting an appropriate MANC SMM. The projected efficiency exceeds 96% not including power loss in the controller. Under full load conditions, the flux density distributions for the SMM stay predominantly <1.3 T, the saturation magnetization of optimized FeNi-based MANC alloys. As a result, the maximum demagnetizing field in the permanent magnet is less than 2.2 × 10 5 A/m sustainable, for example, with a high-grade hard ferrite magnet.« less

Design and simulation of permanent magnet synchronous motor control system

NASA Astrophysics Data System (ADS)

Li, Li; Liu, Yongqiu

2018-06-01

In recent years, with the development of power electronics, microelectronics, new motor control theory and rare earth permanent magnet materials, permanent magnet synchronous motors have been rapidly applied. Permanent magnet synchronous motors have the advantages of small size, low loss and high efficiency. Today, energy conservation and environmental protection are increasingly valued. It is very necessary to study them. Permanent magnet synchronous motor control system has a wide range of application prospects in the fields of electric vehicles, ships and other transportation. Using the simulation function of MATLAB/SIMULINK, a modular design structure was used to simulate the whole system model of speed loop adjustment, current PI modulation, SVPWM (Space Vector Pulse Width Module) wave generation and double closed loop. The results show that this control method has good robustness, and this method can improve the design efficiency and shorten the system design time. In this article, the analysis of the control principle of modern permanent magnet synchronous motor and the various processes of MATLAB simulation application will be analyzed in detail. The basic theory, basic method and application technology of the permanent magnet synchronous motor control system are systematically introduced.

Comparative evaluation of platelet-rich fibrin and mineral trioxide aggregate as pulpotomy agents in permanent teeth with incomplete root development: a randomized controlled trial.

PubMed

Keswani, Deepa; Pandey, Ramesh K; Ansari, Afroz; Gupta, Shalini

2014-05-01

The purpose of this study was to evaluate and compare, clinically and radiographically, the effects of platelet-rich fibrin (PRF) and mineral trioxide aggregate (MTA) as pulpotomy agents in permanent teeth with incomplete root development. A total number of 70 children requiring pulpotomy in 70 permanent molars with incomplete root development were screened. Sixty-two patients met the inclusion criteria and were enrolled in the study. The patients were randomly allocated equally in 2 treatment groups. MTA pulpotomy was performed in group A (the control group), and PRF pulpotomy was performed in group B (the experimental group). The treated teeth were restored with amalgam followed by stainless steel crowns. Clinical and radiographic evaluations were performed after 6, 12, and 24 months. Thus, the data obtained were blindly analyzed using the chi-square test. There was no significant difference between the 2 groups in terms of clinical and radiologic success. Radiographically, all available cases (53 teeth) showed evidence of root growth and canal narrowing. Complete apical closure was observed in 88.8% in the PRF group (experimental group) and 80.07% of roots in the MTA group (control group), respectively, at 24 months. PRF could be used as a suitable biological and economic alternative to MTA in pulpotomy procedures of permanent teeth with incomplete root development. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Early working memory as a racially and ethnically neutral measure of outcome in extremely preterm children at 18-22 months

PubMed Central

Lowe, Jean R.; Duncan, Andrea Freeman; Bann, Carla M.; Fuller, Janell; Hintz, Susan R.; Das, Abhik; Higgins, Rosemary D.; Watterberg, Kristi L.

2013-01-01

Background Difficulties with executive function has been found in preterm children, resulting in difficulties with learning and school performance. Aim This study evaluated the relationship of early working memory as measured by object permanence items to the cognitive and language scores on the Bayley Scales-III in a cohort of children born extremely preterm. Study Design Logistic regression models were conducted to compare object permanence scores derived from the Bayley Scales-III by race/ethnicity and maternal education, controlling for medical covariates. Subjects Extremely preterm toddlers (526), who were part of a Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's multi-center study, were evaluated at 18-22 months corrected age. Outcome Measures Object permanence scores derived from the Bayley Developmental Scales were compared by race/ethnicity and maternal education, controlling for medical covariates. Results There were no significant differences in object permanence mastery and scores among the treatment groups after controlling for medical and social variables, including maternal education and race/ethnicity. Males and children with intraventricular hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia were less likely to demonstrate object permanence mastery and had lower object permanence scores. Children who attained object permanence mastery had significantly higher Bayley Scales-III cognitive and language scores after controlling for medical and socio-economic factors. Conclusions Our measure of object permanence is free of influence from race, ethnic and socio-economic factors. Adding this simple task to current clinical practice could help detect early executive function difficulties in young children. PMID:23993309

Early working memory as a racially and ethnically neutral measure of outcome in extremely preterm children at 18-22 months.

PubMed

Lowe, Jean R; Duncan, Andrea Freeman; Bann, Carla M; Fuller, Janell; Hintz, Susan R; Das, Abhik; Higgins, Rosemary D; Watterberg, Kristi L

2013-12-01

Difficulties with executive function have been found in preterm children, resulting in difficulties with learning and school performance. This study evaluated the relationship of early working memory as measured by object permanence items to the cognitive and language scores on the Bayley Scales-III in a cohort of children born extremely preterm. Logistic regression models were conducted to compare object permanence scores derived from the Bayley Scales-III by race/ethnicity and maternal education, controlling for medical covariates. Extremely preterm toddlers (526), who were part of a Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's multi-center study, were evaluated at 18-22 months corrected age. Object permanence scores derived from the Bayley Developmental Scales were compared by race/ethnicity and maternal education, controlling for medical covariates. There were no significant differences in object permanence mastery and scores among the treatment groups after controlling for medical and social variables, including maternal education and race/ethnicity. Males and children with intraventricular hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia were less likely to demonstrate object permanence mastery and had lower object permanence scores. Children who attained object permanence mastery had significantly higher Bayley Scales-III cognitive and language scores after controlling for medical and socio-economic factors. Our measure of object permanence is free of influence from race, ethnic and socio-economic factors. Adding this simple task to current clinical practice could help detect early executive function difficulties in young children. Published by Elsevier Ireland Ltd.

Direct current force sensing device based on compressive spring, permanent magnet, and coil-wound magnetostrictive/piezoelectric laminate.

PubMed

Leung, Chung Ming; Or, Siu Wing; Ho, S L

2013-12-01

A force sensing device capable of sensing dc (or static) compressive forces is developed based on a NAS106N stainless steel compressive spring, a sintered NdFeB permanent magnet, and a coil-wound Tb(0.3)Dy(0.7)Fe(1.92)/Pb(Zr, Ti)O3 magnetostrictive∕piezoelectric laminate. The dc compressive force sensing in the device is evaluated theoretically and experimentally and is found to originate from a unique force-induced, position-dependent, current-driven dc magnetoelectric effect. The sensitivity of the device can be increased by increasing the spring constant of the compressive spring, the size of the permanent magnet, and/or the driving current for the coil-wound laminate. Devices of low-force (20 N) and high-force (200 N) types, showing high output voltages of 262 and 128 mV peak, respectively, are demonstrated at a low driving current of 100 mA peak by using different combinations of compressive spring and permanent magnet.

Permanent magnet design methodology

NASA Technical Reports Server (NTRS)

Leupold, Herbert A.

1991-01-01

Design techniques developed for the exploitation of high energy magnetically rigid materials such as Sm-Co and Nd-Fe-B have resulted in a revolution in kind rather than in degree in the design of a variety of electron guidance structures for ballistic and aerospace applications. Salient examples are listed. Several prototype models were developed. These structures are discussed in some detail: permanent magnet solenoids, transverse field sources, periodic structures, and very high field structures.

Solution-Phase Dynamic Assembly of Permanently Interlocked Aryleneethynylene Cages through Alkyne Metathesis

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

Wang, Qi; Yu, Chao; Long, Hai

2015-05-08

Highly stable permanently interlocked aryleneethynylene molecular cages were synthesized from simple triyne monomers using dynamic alkyne metathesis. The interlocked complexes are predominantly formed in the reaction solution in the absence of any recognition motif and were isolated in a pure form using column chromatography. This study is the first example of the thermodynamically controlled solution-phase synthesis of interlocked organic cages with high stability.

Principle and Basic Characteristics of a Hybrid Variable-Magnetic-Force Motor

NASA Astrophysics Data System (ADS)

Sakai, Kazuto; Kuramochi, Satoru

Reduction in the power consumed by motors is important for energy saving in the case of electrical appliances and electric vehicles (EVs). The motors used for operating these devices operate at variable speeds. Further, the motors operate with a small load in the stationary mode and a large load in the starting mode. A permanent magnet motor can be operated at the rated power with a high efficiency. However, the efficiency is low at a small load or at a high speed because the large constant magnetic force results in substantial core loss. Furthermore, the flux-weakening current that decreases the voltage at a high speed leads to significant copper loss and core loss. Therefore, we have developed a new technique for controlling the magnetic force of a permanent magnet on the basis of the load or speed of the motor. In this paper, we propose a novel motor that can vary the magnetic flux of a permanent magnet and clarify the principle and basic characteristics of the motor. The new motor has a permanent magnet that is magnetized by the magnetizing coil of the stator. The analysis results show that the magnetic flux linkage of the motor can be changed from 37% to 100% that a high torque can be produced.

Developmental Disturbances of a Maxillary Central Incisor due to Trauma to Its Predecessor: A Case Report

PubMed Central

Karataş, Merve Safa; Sönmez, Işıl Şaroğlu

2013-01-01

Objective To report the effects of a primary tooth trauma on the underlying permanent tooth germ. Clinical Presentation and Intervention A 12-year-old girl was referred to our clinic with a complaint of poor aesthetic appearance. The crown of the permanent maxillary left central tooth exhibited an increased clinical crown height with an ‘enamel hyperplasia’ in the cervical third and had hypoplastic enamel with yellowish-brown discoloration extending from the middle third to the incisal edge. Radiographic examination revealed that the permanent maxillary left central tooth had abnormal root morphology with root dilaceration. The patient revealed a history of trauma at the age of 4 years. An aesthetic restoration with light-curing resin composite was performed on the vestibular surface of the maxillary left permanent central tooth. Conclusion Sequelae of a primary tooth trauma on the permanent tooth were restored. We recommend that parents should be aware of the consequences of untreated trauma to a primary tooth. Educational and preventive programmes on dental trauma are required to educate parents about emergency knowledge and sequelae of dental trauma. PMID:23689528

AC Application of HTS Conductors in Highly Dynamic Electric Motors

NASA Astrophysics Data System (ADS)

Oswald, B.; Best, K.-J.; Setzer, M.; Duffner, E.; Soell, M.; Gawalek, W.; Kovalev, L. K.

2006-06-01

Based on recent investigations we design highly dynamic electric motors up to 400 kW and linear motors up to 120 kN linear force using HTS bulk material and HTS tapes. The introduction of HTS tapes into AC applications in electric motors needs fundamental studies on double pancake coils under transversal magnetic fields. First theoretical and experimental results on AC field distributions in double-pancake-coils and corresponding AC losses will be presented. Based on these results the simulation of the motor performance confirms extremely high power density and efficiency of both types of electric motors. Improved characteristics of rare earth permanent magnets used in our motors at low temperatures give an additional technological benefit.

Cast Aluminum Alloy for High Temperature Applications

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.

2003-01-01

Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent dimensional stability, surface hardness and wear resistant properties.

Method and apparatus for data sampling

DOEpatents

Odell, Daniel M. C.

1994-01-01

A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium.

A high-throughput exploration of magnetic materials by using structure predicting methods

NASA Astrophysics Data System (ADS)

Arapan, S.; Nieves, P.; Cuesta-López, S.

2018-02-01

We study the capability of a structure predicting method based on genetic/evolutionary algorithm for a high-throughput exploration of magnetic materials. We use the USPEX and VASP codes to predict stable and generate low-energy meta-stable structures for a set of representative magnetic structures comprising intermetallic alloys, oxides, interstitial compounds, and systems containing rare-earths elements, and for both types of ferromagnetic and antiferromagnetic ordering. We have modified the interface between USPEX and VASP codes to improve the performance of structural optimization as well as to perform calculations in a high-throughput manner. We show that exploring the structure phase space with a structure predicting technique reveals large sets of low-energy metastable structures, which not only improve currently exiting databases, but also may provide understanding and solutions to stabilize and synthesize magnetic materials suitable for permanent magnet applications.

Individual Differences in Beat Perception Affect Gait Responses to Low- and High-Groove Music

PubMed Central

Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A.

2014-01-01

Slowed gait in patients with Parkinson’s disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the “beat,” which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation. PMID:25374521

Caries prevalence and manganese and iron levels of drinking water in school children living in a rural/semi-urban region of North-Eastern Greece.

PubMed

Tsanidou, Eirini; Nena, Evangelia; Rossos, Alexandros; Lendengolts, Zhanna; Nikolaidis, Christos; Tselebonis, Athanasios; Constantinidis, Theodoros C

2015-11-01

The aim of this study was to correlate different combinations of manganese (Mn) and iron (Fe) concentration in drinking water with prevalence of dental caries in both primary and permanent dentition, among school children with similar socio-demographic characteristics. Evros region, in North-Eastern Greece, was divided into four areas, according to combinations of levels of Mn and Fe in drinking water (High Mn-high Fe; High Mn-low Fe; Low Mn-high Fe; Low Mn-low Fe). Children of similar socio-economic background, attending either first or sixth grade (primary or permanent dentition, respectively) of elementary schools, were clinically assessed for caries by three dentists. Caries was defined by the use of dmft/DMFT index. A questionnaire answered by the parents was also analysed. 573 children were included. Caries prevalence was high in both age groups (64.2 % with mean dmft 3.3 ± 3.6 in primary and 60.7 % with mean DMFT 2.3 ± 2.5 in permanent dentition, respectively). Residence in a high Mn-low Fe area was associated with a significant OR for caries in both age groups [OR (95 % CIs) for primary and permanent dentition was, respectively, 3.75 (1.68-8.37), p = 0.001 and 3.09 (1.48-6.44), p = 0.003], independently of factors like sugar consumption or brushing frequency. Prevalence of caries was high in general, and was associated with the combination of high Mn/low Fe levels in drinking water, independently of various socio-demographic factors.

Transformation Craft (T-Craft) Concept Study

DTIC Science & Technology

2007-08-01

turbines (General Electric LM1600, each at 14MW) 3 high temperature superconductor electric generators 2 permanent magnet motors 2 shafts (pumpjets...pump-jet propulsor and permanent magnet motors at the far aft of the ship, the gas turbine generator sets were moved quite far forward (to directly

High-Level Radioactive Waste: Safe Storage and Ultimate Disposal.

ERIC Educational Resources Information Center

Dukert, Joseph M.

Described are problems and techniques for safe disposal of radioactive waste. Degrees of radioactivity, temporary storage, and long-term permanent storage are discussed. Included are diagrams of estimated waste volumes to the year 2000 and of an artist's conception of a permanent underground disposal facility. (SL)

Permanent laser conditioning of thin film optical materials

DOEpatents

Wolfe, C. Robert; Kozlowski, Mark R.; Campbell, John H.; Staggs, Michael; Rainer, Frank

1995-01-01

The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold.

Metal-Organic Framework-Derived NiSb Alloy Embedded in Carbon Hollow Spheres as Superior Lithium-Ion Battery Anodes.

PubMed

Yu, Litao; Liu, Jun; Xu, Xijun; Zhang, Liguo; Hu, Renzong; Liu, Jiangwen; Yang, Lichun; Zhu, Min

2017-01-25

The MOFs (metal-organic frameworks) have been extensively used for electrode materials due to their high surface area, permanent porosity, and hollow structure, but the role of antimony on the MOFs is unclear. In this work, we design the hollow spheres Ni-MOFs with SbCl 3 to synthesize NiSb⊂CHSs (NiSb-embedded carbon hollow spheres) via simple annealing and galvanic replacement reactions. The NiSb⊂CHSs inherited the advantages of Ni-MOFs with hollow structure, high surface area, and permanent porosity, and the NiSb nanoparticles are coated by the formed carbon particles which could effectively solve the problem of vigorous volume changes during the Li + insertion/extraction process. The porous and network structure could well provide an extremely reduced pathway for fast Li + diffusion and electron transport and provide extra free space for alleviating the structural strain. The NiSb⊂CHSs with these features were used as Li-ion batteries for the first time and exhibited excellent cycling performance, high specific capacity, and great rate capability. When coupled with a nanostructure LiMn 2 O 4 cathode, the NiSb⊂CHSs//LiMn 2 O 4 full cell also characterized a high voltage operation of ≈3.5 V, high rate capability (210 mA h g -1 at a current density of 2000 mA g -1 ), and high Coulombic efficiency of approximate 99%, meeting the requirement for the increasing demand for improved energy devices.

Simple Motor Control Concept Results High Efficiency at High Velocities

NASA Astrophysics Data System (ADS)

Starin, Scott; Engel, Chris

2013-09-01

The need for high velocity motors in space applications for reaction wheels and detectors has stressed the limits of Brushless Permanent Magnet Motors (BPMM). Due to inherent hysteresis core losses, conventional BPMMs try to balance the need for torque verses hysteresis losses. Cong-less motors have significantly less hysteresis losses but suffer from lower efficiencies. Additionally, the inherent low inductance in cog-less motors result in high ripple currents or high switching frequencies, which lowers overall efficiency and increases performance demands on the control electronics.However, using a somewhat forgotten but fully qualified technology of Isotropic Magnet Motors (IMM), extremely high velocities may be achieved at low power input using conventional drive electronics. This paper will discuss the trade study efforts and empirical test data on a 34,000 RPM IMM.

Object permanence in the food-storing coal tit (Periparus ater) and the non-storing great tit (Parus major): Is the mental representation required?

PubMed

Marhounová, Lucie; Frynta, Daniel; Fuchs, Roman; Landová, Eva

2017-05-01

Object permanence is a cognitive ability that enables animals to mentally represent the continuous existence of temporarily hidden objects. Generally, it develops gradually through six qualitative stages, the evolution of which may be connected with some specific ecological and behavioral factors. In birds, the advanced object permanence skills were reported in several storing species of the Corvidae family. In order to test the association between food-storing and achieved performance within the stages, we compared food-storing coal tits (Periparus ater) and nonstoring great tits (Parus major) using an adapted version of Uzgiris & Hunt's Scale 1 tasks. The coal tits significantly outperformed the great tits in searching for completely hidden objects. Most of the great tits could not solve the task when the object disappeared completely. However, the upper limit for both species is likely to be Stage 4. The coal tits could solve problems with simply hidden objects, but they used alternative strategies rather than mental representation when searching for completely hidden objects, especially if choosing between two locations. Our results also suggest that neophobia did not affect the overall performance in the object permanence tasks. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

PubMed Central

N., Chuchueva; C., Gerosa; S., Sionis; R.A., Caria; R., Puxeddu

2017-01-01

SUMMARY Temporary and permanent facial nerve dysfunctions can be observed after parotidectomy for benign and malignant lesions. Intraoperative nerve monitoring is a recognised tool for the preservation of the nerve, while the efficacy of the operative microscope has been rarely stated. The authors report their experience on 198 consecutive parotidectomies performed on 196 patients with the aid of the operative microscope and intraoperative nerve monitoring. 145 parotidectomies were performed for benign lesions and 53 for malignancies. Thirteen patients treated for benign tumours experienced temporary (11 cases) or permanent facial palsy (2 cases, both of House-Brackmann grade II). Ten patients with malignant tumour presented with preoperative facial nerve weakness that did not improve after treatment. Five and 6 patients with malignant lesion without preoperative facial nerve deficit experienced postoperative temporary and permanent weakness respectively (the sacrifice of a branch of the nerve was decided intraoperatively in 2 cases). Long-term facial nerve weakness after parotidectomy for lesions not directly involving or originating from the facial nerve (n = 185) was 2.7%. Patients treated for benign tumours of the extra facial portion of the gland without inflammatory behaviour (n = 91) had 4.4% facial nerve temporary weakness rate and no permanent palsy. The combined use of the operative microscope and intraoperative nerve monitoring seems to guarantee facial nerve preservation during parotidectomy. PMID:29165432

Prevalence and factors affecting use of long acting and permanent contraceptive methods in Jinka town, Southern Ethiopia: a cross sectional study.

PubMed

Mekonnen, Getachew; Enquselassie, Fikre; Tesfaye, Gezahegn; Semahegn, Agumasie

2014-01-01

In Ethiopia, knowledge of contraceptive methods is high though there is low contraceptive prevalence rate. This study was aimed to assess prevalence and associated factors of long acting and permanent contraceptive methods in Jinka town, southern Ethiopia. Community based cross sectional survey was conducted to assess the prevalence and factors affecting long acting and permanent methods of contraceptives utilization from March to April 2008. Eight hundred child bearing age women were participated in the quantitative study and 32 purposively selected focus group discussants were participated in the qualitative study. Face to face interview was used for data collection. Data were analyzed by SPSS version 13.0 statistical software. Descriptive statistics and logistic regression were computed to analyze the data. The prevalence of long acting and permanent contraceptive method was 7.3%. Three fourth (76.1%) of the women have ever heard about implants and implant 28 (50%) were the most widely used method. Almost two third of women had intention to use long acting and permanent methods. Knowledge of contraceptive and age of women have significant association with the use of long acting and permanent contraceptive methods. The overall prevalence of long acting and permanent contraceptive method was low. Knowledge of contraceptive and age of women have significant association with use of long acting and permanent contraceptive. Extensive health information should be provided.

Permanent magnetic field, direct electric field, and infrared to reduce blood glucose level and hepatic function in mus musculus with diabetic mellitus

NASA Astrophysics Data System (ADS)

Suhariningsih; Basuki Notobroto, Hari; Winarni, Dwi; Achmad Hussein, Saikhu; Anggono Prijo, Tri

2017-05-01

Blood contains several electrolytes with positive (cation) and negative (anion) ion load. Both electrolytes deliver impulse synergistically adjusting body needs. Those electrolytes give specific effect to external disturbance such as electric, magnetic, even infrared field. A study has been conducted to reduce blood glucose level and liver function, in type 2 Diabetes Mellitus patients, using Biophysics concept which uses combination therapy of permanent magnetic field, electric field, and infrared. This study used 48 healthy mice (mus musculus), male, age 3-4 weeks, with approximately 25-30 g in weight. Mice was fed with lard as high fat diet orally, before Streptozotocin (STZ) induction become diabetic mice. Therapy was conducted by putting mice in a chamber that emits the combination of permanent magnetic field, electric field, and infrared, every day for 1 hour for 28 days. There were 4 combinations of therapy/treatment, namely: (1) permanent magnetic field, direct electric field, and infrared; (2) permanent magnetic field, direct electric field, without infrared; (3) permanent magnetic field, alternating electric field, and infrared; and (4) permanent magnetic field, alternating electric field, without infrared. The results of therapy show that every combination is able to reduce blood glucose level, AST, and ALT. However, the best result is by using combination of permanent magnetic field, direct electric field, and infrared.

Improvement of microwave feeding on a large bore ECRIS with permanent magnets by using coaxial semi-dipole antenna

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

Kurisu, Yosuke; Sakamoto, Naoki; Kiriyama, Ryutaro

2012-11-06

We are constructing a tandem type electron cyclotron resonance (ECR) ion source (ECRIS). The first stage of this ECRIS has a large-bore with cylindrically comb-shaped permanent magnets. 2.45GHz and 11-13GHz microwaves can be supplied individually and simultaneously to the plasma chamber. For 2.45GHz, a coaxial semi-dipole antenna is used to feed the microwaves. In previous experiments, there were two problems encountered when running the 2.45GHz microwaves. High incident power was necessary to keep ECR discharge at low operating pressure because of high reflected microwave power. The surface of a support insulator between the inner and the outer electrodes of coaxialmore » semi-dipole antenna was easily metalized by sputtering of the metal wall inside the chamber. The purpose of this study was to solve these problems. Performing several simulation experiments supports the hypothesis that the position of the support insulator is significant for microwave power efficiency. The end result was the ability to sustain ECR discharges at extremely low incident microwave power, several tens of watts, by optimized matching of the position and shape of the insulator.« less

Monte Carlo Simulation Study of Atomic Structure of alnico Permanent Magnets

NASA Astrophysics Data System (ADS)

Nguyen, Manh Cuong; Wang, Cai-Zhuang; Ho, Kai-Ming

Lattice Monte Carlo simulation based on quinternary cluster expansion energy model is used to investigate nano-scale structure of alnico alloy, which is considered as a candidate material for rare-earth free high performance permanent magnets, especially for high or elevated temperature applications such as electric motor for vehicles. We observe phase decomposition of the master alnico alloy into FeCo-rich magnetic (α1) and NiAl-rich matrix (α2) phases. Concentrations of Fe and Co in α1 phase and Ni and Al in α2 phase are higher for lower annealing temperature. Ti is residing mostly in the α2 phase. The phase boundary between α1 and α2 phases are quite sharp with only few atomic layers. The α1 phase is in B2 ordering with Fe and Al occupying the α-site and Ni and Co occupying the β-site. The α2 phase is in L21 ordering with Al occupying the 4a-site. The phase composition profile again annealing temperature suggests that lower annealing temperature would improve the magnetism of α2 and diminish the magnetism of α2 phase, hence improve shape anisotropy of α1 phase rods and that of alnico.

Managing high-bandwidth real-time data storage

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

Bigelow, David D.; Brandt, Scott A; Bent, John M

2009-09-23

There exist certain systems which generate real-time data at high bandwidth, but do not necessarily require the long-term retention of that data in normal conditions. In some cases, the data may not actually be useful, and in others, there may be too much data to permanently retain in long-term storage whether it is useful or not. However, certain portions of the data may be identified as being vitally important from time to time, and must therefore be retained for further analysis or permanent storage without interrupting the ongoing collection of new data. We have developed a system, Mahanaxar, intended tomore » address this problem. It provides quality of service guarantees for incoming real-time data streams and simultaneous access to already-recorded data on a best-effort basis utilizing any spare bandwidth. It has built in mechanisms for reliability and indexing, can scale upwards to meet increasing bandwidth requirements, and handles both small and large data elements equally well. We will show that a prototype version of this system provides better performance than a flat file (traditional filesystem) based version, particularly with regard to quality of service guarantees and hard real-time requirements.« less

Localization for robotic capsule looped by axially magnetized permanent-magnet ring based on hybrid strategy.

PubMed

Yang, Wanan; Li, Yan; Qin, Fengqing

2015-01-01

To actively maneuver a robotic capsule for interactive diagnosis in the gastrointestinal tract, visualizing accurate position and orientation of the capsule when it moves in the gastrointestinal tract is essential. A possible method that encloses the circuits, batteries, imaging device, etc into the capsule looped by an axially magnetized permanent-magnet ring is proposed. Based on expression of the axially magnetized permanent-magnet ring's magnetic fields, a localization and orientation model was established. An improved hybrid strategy that combines the advantages of particle-swarm optimization, clone algorithm, and the Levenberg-Marquardt algorithm was found to solve the model. Experiments showed that the hybrid strategy has good accuracy, convergence, and real time performance.

Simulation of double stage hall thruster with double-peaked magnetic field

NASA Astrophysics Data System (ADS)

Ding, Yongjie; Li, Peng; Sun, Hezhi; Wei, Liqiu; Xu, Yu; Peng, Wuji; Su, Hongbo; Li, Hong; Yu, Daren

2017-07-01

This study adopts double permanent magnetic rings and four permanent magnetic rings to form two symmetrical magnetic peaks and two asymmetrical magnetic peaks in the channel of a Hall thruster, and uses a 2D-3V PIC-MCC model to analyze the influence of magnetic strength on the discharge characteristic and performance of Hall thrusters with an intermediate electrode and double-peaked magnetic field. As opposed to the two symmetrical magnetic peaks formed by double permanent magnetic rings, increasing the magnetic peak value deep within the channel can cause propellant ionization to occur; with the increase in the magnetic peak deep in the channel, the propellant utilization, thrust, and anode efficiency of the thruster are significantly improved. Double-peaked magnetic field can realize separate control of ionization and acceleration in a Hall thruster, and provide technical means for further improving thruster performance. Contribution to the Topical Issue "Physics of Ion Beam Sources", edited by Holger Kersten and Horst Neumann.

Dynamic Resource Management for Parallel Tasks in an Oversubscribed Energy-Constrained Heterogeneous Environment

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

Imam, Neena; Koenig, Gregory A; Machovec, Dylan

2016-01-01

Abstract: The worth of completing parallel tasks is modeled using utility functions, which monotonically-decrease with time and represent the importance and urgency of a task. These functions define the utility earned by a task at the time of its completion. The performance of such a system is measured as the total utility earned by all completed tasks over some interval of time (e.g., 24 hours). To maximize system performance when scheduling dynamically arriving parallel tasks onto a high performance computing (HPC) system that is oversubscribed and energy-constrained, we have designed, analyzed, and compared different heuristic techniques. Four utility-aware heuristics (i.e.,more » Max Utility, Max Utility-per-Time, Max Utility-per-Resource, and Max Utility-per-Energy), three FCFS-based heuristics (Conservative Backfilling, EASY Backfilling, and FCFS with Multiple Queues), and a Random heuristic were examined in this study. A technique that is often used with the FCFS-based heuristics is the concept of a permanent reservation. We compare the performance of permanent reservations with temporary place-holders to demonstrate the advantages that place-holders can provide. We also present a novel energy filtering technique that constrains the maximum energy-per-resource used by each task. We conducted a simulation study to evaluate the performance of these heuristics and techniques in an energy-constrained oversubscribed HPC environment. With place-holders, energy filtering, and dropping tasks with low potential utility, our utility-aware heuristics are able to significantly outperform the existing FCFS-based techniques.« less

Extrapyramidal signs in normal pressure hydrocephalus: an objective assessment

PubMed Central

Mandir, Allen S; Hilfiker, Jennifer; Thomas, George; Minahan, Robert E; Crawford, Thomas O; Williams, Michael A; Rigamonti, Daniele

2007-01-01

Background Beyond the classic Normal Pressure Hydrocephalus (NPH) triad of gait disturbance, incontinence, and dementia are characteristic signs of motor dysfunction in NPH patients. We used highly sensitive and objective methods to characterize upper limb extrapyramidal signs in a series of NPH subjects compared with controls. Concentrated evaluation of these profound, yet underappreciated movement disorders of NPH before and after techniques of therapeutic intervention may lead to improved diagnosis, insight into pathophysiology, and targeted treatment. Methods Twenty-two (22) consecutive NPH patients and 17 controls performed an upper limb motor task battery where highly sensitive and objective measures of akinesia/bradykinesia, tone, and tremor were conducted. NPH subjects performed this test battery before and more than 36 h after continuous CSF drainage via a spinal catheter over 72 h and, in those subjects undergoing permanent ventriculo-peritoneal shunt placement, at least 12 weeks later. Control subjects performed the task battery at the same dates as the NPH subjects. Statistical analyses were applied to group populations of NPH and control subjects and repeated measures for within subject performance. Results Twenty (20) NPH subjects remained in the study following CSF drainage as did 14 controls. NPH subjects demonstrated akinesia/bradykinesia (prolonged reaction and movement times) and increased resting tone compared with controls. Furthermore, the NPH group demonstrated increased difficulty with self-initiated tasks compared with stimulus-initiated tasks. Following CSF drainage, some NPH subjects demonstrated reduced movement times with greater improvement in self- versus stimulus-initiated tasks. Group reaction time was unchanged. Resting tremor present in one NPH subject resolved following shunt placement. Tone measures were consistent for all subjects throughout the study. Conclusion Clinical motor signs of NPH subjects extend beyond gait deficits and include extrapyramidal manifestations of bradykinesia, akinesia, rigidity, and propensity to perform more poorly when external cues to move are absent. Objective improvement of some but not all of these features was seen following temporary or permanent CSF diversion. PMID:17697324

Optimization study on the magnetic field of superconducting Halbach Array magnet

NASA Astrophysics Data System (ADS)

Shen, Boyang; Geng, Jianzhao; Li, Chao; Zhang, Xiuchang; Fu, Lin; Zhang, Heng; Ma, Jun; Coombs, T. A.

2017-07-01

This paper presents the optimization on the strength and homogeneity of magnetic field from superconducting Halbach Array magnet. Conventional Halbach Array uses a special arrangement of permanent magnets which can generate homogeneous magnetic field. Superconducting Halbach Array utilizes High Temperature Superconductor (HTS) to construct an electromagnet to work below its critical temperature, which performs equivalently to the permanent magnet based Halbach Array. The simulations of superconducting Halbach Array were carried out using H-formulation based on B-dependent critical current density and bulk approximation, with the FEM platform COMSOL Multiphysics. The optimization focused on the coils' location, as well as the geometry and numbers of coils on the premise of maintaining the total amount of superconductor. Results show Halbach Array configuration based superconducting magnet is able to generate the magnetic field with intensity over 1 Tesla and improved homogeneity using proper optimization methods. Mathematical relation of these optimization parameters with the intensity and homogeneity of magnetic field was developed.

Rapid micromixer via ferrofluids

NASA Astrophysics Data System (ADS)

Fu, L. M.; Tsai, C. H.; Leong, K. P.; Wen, C. Y.

Performances of a micromixer based on ferrofluids are predicted numerically. A permanent magnet is used to induce transient interactive flows between a water-based ferrofluid and water. The external magnetic field causes the ferrofluid to expand significantly and uniformly toward miscible water, associated with a great number of extremely fine fingering structures on the interface in the upstream and downstream regions of the microchannel. These pronounced fingering patterns, which mimic the experimental observations of Wen et al. (2009), increase the mixing interfacial length dramatically. Along with the dominant diffusion effects occurring around the circumferential regions of the fine finger structures, the mixing efficiency increases significantly. The mixing efficiency can be as high as 95% within 2.0 s and a distance of 3.0 mm from the inlet of the mixing channel, when the applied peak magnetic field is 145.8 Oe. The proposed mixing scheme not only provides an excellent mixing, even in simple microchannel, but also can be easily applied to lab-on-a-chip applications with an external permanent magnet.

Testing the stand-alone microbeam at Columbia University.

PubMed

Garty, G; Ross, G J; Bigelow, A W; Randers-Pehrson, G; Brenner, D J

2006-01-01

The stand-alone microbeam at Columbia University presents a novel approach to biological microbeam irradiation studies. Foregoing a conventional accelerator as a source of energetic ions, a small, high-specific-activity, alpha emitter is used. Alpha particles emitted from this source are focused using a compound magnetic lens consisting of 24 permanent magnets arranged in two quadrupole triplets. Using a 'home made' 6.5 mCi polonium source, a 1 alpha particle s(-1), 10 microm diameter microbeam can, in principle, be realised. As the alpha source energy is constant, once the microbeam has been set up, no further adjustments are necessary apart from a periodic replacement of the source. The use of permanent magnets eliminates the need for bulky power supplies and cooling systems required by other types of ion lenses and greatly simplifies operation. It also makes the microbeam simple and cheap enough to be realised in any large lab. The Microbeam design as well as first tests of its performance, using an accelerator-based beam are presented here.

Use of Permanent Magnets in Electromagnetic Facilities for the Treatment of Aluminum Alloys

NASA Astrophysics Data System (ADS)

Beinerts, Toms; Bojarevičs, Andris; Bucenieks, Imants; Gelfgat, Yuri; Kaldre, Imants

2016-06-01

The possibility of applying the electromagnetic induction pump with permanent magnets for the transportation and stirring of aluminum melts in metallurgical furnaces is investigated. The electromagnetic and hydraulic characteristics of the pump have been investigated theoretically and experimentally with regard to its position in the furnace. The results of the experiments performed with a model in a eutectic InGaSn melt are in good agreement with the calculation data. Extrapolation of the experimental results on the physical characteristics of aluminum melts allows recommending such pumps for contactless control of motion and heat/mass transfer in aluminum melts in different technological processes. A high temperature and the aggressive properties of aluminum alloys make it complicated to use different mechanical devices to solve technological problems, such as liquid metal transportation, dosing, stirring, etc. In this case, any device units or elements moving in or contacting with the melt suffer from corrosion polluting the melt. Therefore, of more importance and topicality are contactless electromagnetic methods for processing of molten metals.

Numerical run-out modelling used for reassessment of existing permanent avalanche paths in the Krkonose Mts., Czechia

NASA Astrophysics Data System (ADS)

Blahut, Jan; Klimes, Jan; Balek, Jan; Taborik, Petr; Juras, Roman; Pavlasek, Jiri

2015-04-01

Run-out modelling of snow avalanches is being widely applied in high mountain areas worldwide. This study presents application of snow avalanche run-out calculation applied to mid-mountain ranges - the Krkonose, Jeseniky and Kralicky Sneznik Mountains. All mentioned mountain ranges lie in the northern part of Czechia, close to the border with Poland. Its highest peak reaches only 1602 m a.s.l. However, climatic conditions and regular snowpack presence are the reason why these mountain ranges experience considerable snow avalanche activity every year, sometimes resulting in injuries or even fatalities. Within the aim of an applied project dealing with snow avalanche hazard prediction a re-assessment of permanent snow avalanche paths has been performed based on extensive statistics covering period from 1961/62 till present. On each avalanche path different avalanches with different return periods were modelled using the RAMMS code. As a result, an up-to-date snow avalanche hazard map was prepared.

Association between work-related health problems and job insecurity in permanent and temporary employees

PubMed Central

2013-01-01

Objectives This research was conducted with an aim of determining the correlation between job insecurity and an employee’s work-related health problems among permanent and temporary workers. Methods Using the data from the First Korean Working Conditions Survey conducted in 2006, a total of 7,071 workers, excluding employers and the self-employed, were analyzed. Work-related health problems were categorized as backache, headache, abdominal pain, muscular pain, stress, fatigue, insomnia, anxiety or depression. Each problem was then analyzed for its relationship to job insecurity through logistic regression analysis. Results Among the 7,071 workers, 5,294 (74.9%) were permanent workers and 1,777 (25.1%) were temporary workers. For the permanent workers, presence of high or moderate job insecurity appeared more closely linked to backache, headache, abdominal pain, muscular pain, stress, fatigue, insomnia, anxiety, and depression compared to absence of job insecurity. However, for the temporary workers, only depression appeared to be associated with the presence of high job insecurity. Conclusion The study showed that the presence of job insecurity is correlated with work-related health problems. The deleterious effects of job insecurity appeared to be stronger in permanent than temporary workers. Additional research should investigate ways to effectively reduce job insecurity. PMID:24472497

Carbon dioxide-water clathrate as a reservoir of CO2 on Mars

NASA Technical Reports Server (NTRS)

Dobrovolskis, A.; Ingersell, A. P.

1975-01-01

It has been suggested that the residual polar caps of Mars contain a resorvoir of permanently frozen carbon dioxide which is controlling the atmospheric pressure. However, observational data and models of the polar heat balance suggest that the temperatures of the Martian poles are too high for solid CO2 to survive permanently. On the other hand, the icelike compound carbon dioxide-water clathrate could function as a CO2 reservoir instead of solid CO2, because it is stable at higher temperatures. This paper shows that the permanent polar caps may contain several millibars of CO2 in the form of clathrate, and discusses the implications of this permanent clathrate reservoir for the present and past atmospheric pressure on Mars.

Electromagnetic machines with Nd-Fe-B magnets

NASA Astrophysics Data System (ADS)

Hanitsch, Rolf

1989-08-01

Permanent magnet motors are now becoming more accepted for general use in industrial fixed and variable speed drives. With the application of high-energy permanent magnets, such as Nd-Fe-B, the new motors offer higher efficiency and reduced size and weight compared with wound field energy converters of the same rating.

Frictionless Bearing Uses Permanent Magnets

NASA Technical Reports Server (NTRS)

1965-01-01

The purpose of this innovation was to develop a frictionless bearing for high speed, light load applications. The device involves the incorporation of permanent magnets in the bearing design. The repulsion of like magnetic poles provides concentric support of the inner member so that no metallic contact occurs between the bearing surfaces.

Permanent laser conditioning of thin film optical materials

DOEpatents

Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

1995-12-05

The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold. 9 figs.

Current practice, accuracy, effectiveness and cost-effectiveness of the school entry hearing screen.

PubMed

Bamford, J; Fortnum, H; Bristow, K; Smith, J; Vamvakas, G; Davies, L; Taylor, R; Watkin, P; Fonseca, S; Davis, A; Hind, S

2007-08-01

To describe and analyse in detail current practice of school entry hearing screening (SES) in the UK. Main electronic databases were searched up to May 2005. A national postal questionnaire survey was addressed to all leads for SES in the UK, considering current practice in terms of implementation, protocols, target population and performance data. Primary data from cohort studies in one area of London were examined. A systematic review of alternative SES tests, test performance and impact on outcomes was carried out. Finally, a review of published studies on costs, plus economic modelling of current and alternative programmes was prepared. The survey suggested that SES is used in most of England, Wales and Scotland; just over 10% of respondents have abandoned the screen; others are awaiting national guidance. Coverage of SES is variable, but is often over 90% for children in state schools. Referral rates are variable, with a median of about 8%. The test used for the screen is the pure tone sweep test but with wide variation in implementation, with differing frequencies, pass criteria and retest protocols; written examples of protocols were often poor and ambiguous. There is no national approach to data collection, audit and quality assurance, and there are variable approaches at local level. The screen is performed in less than ideal test conditions and resources are often limited, which has an impact on the quality of the screen. The primary cohort studies show that the prevalence of permanent childhood hearing loss continues to increase through infancy. Of the 3.47 in 1000 children with a permanent hearing loss at school screen age, 1.89 in 1000 required identification after the newborn screen. Newborn hearing screening is likely to reduce significantly the yield of SES for permanent bilateral and unilateral hearing impairments; yield had fallen from about 1.11 in 1000 before newborn screening to about 0.34 in 1000 for cohorts that had had newborn screening, of which only 0.07 in 1000 were unilateral impairments. Just under 20% of permanent moderate or greater bilateral, mild bilateral and unilateral impairments, known to services as 6-year-olds or older, remained to be identified around the time of school entry. No good-quality published comparative trials of alternative screens or tests for SES were identified and studies concerned with the relative accuracy of alternative tests are difficult to compare and often flawed by differing referral criteria and case definitions; with full pure tone audiometry as the reference test, the pure tone sweep test appears to have high sensitivity and high specificity for minimal, mild and greater hearing impairments, better than alternative tests for which evidence was identified. There is insufficient evidence regarding possible harm of the screen. There were no published studies identified that examined the possible effects of SES on longer term outcomes. No good-quality published economic evaluations of SES were identified and a universal SES based on pure tone sweep tests was associated with higher costs and slightly higher quality-adjusted life-years (QALYs) compared with no screen and other screen alternatives; the incremental cost-effectiveness ratio for such a screen is around 2500 pounds per QALY gained; the range of expected costs, QALYs and net benefits was broad, indicating a considerable degree of uncertainty. Targeted screening could be more cost-effective than universal school entry screening; however, the lack of primary data and the wide limits for variables in the modelling mean that any conclusions must be considered indicative and exploratory only. A national screening programme for permanent hearing impairment at school entry meets all but three of the criteria for a screening programme, but at least six criteria are not met for screening for temporary hearing impairment. The lack of good-quality evidence in this area remains a serious problem. Services should improve quality and audit screen performance for identification of previously unknown permanent hearing impairment, pending evidence-based policy decisions based on the research recommendations. Further research is needed into a number of important areas including the evaluation of an agreed national protocol for services delivering SES to make future studies and audits of screen performance more directly comparable.

30 CFR 947.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Performance standards-coal exploration. 947.815... Performance standards—coal exploration. (a) Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. (b) Any person who...

30 CFR 947.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Performance standards-coal exploration. 947.815... Performance standards—coal exploration. (a) Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. (b) Any person who...

30 CFR 947.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Performance standards-coal exploration. 947.815... Performance standards—coal exploration. (a) Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. (b) Any person who...

30 CFR 947.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Performance standards-coal exploration. 947.815... Performance standards—coal exploration. (a) Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. (b) Any person who...

30 CFR 947.815 - Performance standards-coal exploration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Performance standards-coal exploration. 947.815... Performance standards—coal exploration. (a) Part 815 of this chapter, Permanent Program Performance Standards—Coal Exploration, shall apply to any person conducting coal exploration operations. (b) Any person who...

The CMS High-Level Trigger

NASA Astrophysics Data System (ADS)

Covarelli, R.

2009-12-01

At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the "High-Level Trigger" (HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, τ leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity.

A survey of current clinical practice in permanent and temporary prostate brachytherapy: 2010 update.

PubMed

Buyyounouski, Mark K; Davis, Brian J; Prestidge, Bradley R; Shanahan, Thomas G; Stock, Richard G; Grimm, Peter D; Demanes, D Jeffrey; Zaider, Marco; Horwitz, Eric M

2012-01-01

To help establish patterns of care and standards of care of interstitial permanent low-dose-rate (LDR) and temporary high-dose-rate brachytherapy for prostate cancer and to compare the results with a similar 1998 American Brachytherapy Society (ABS) survey. A comprehensive questionnaire intended to survey specific details of current clinical brachytherapy practice was provided to the participants of the seventh ABS Prostate Brachytherapy School. Responses were tabulated and descriptive statistics are reported. Sixty-five brachytherapy practitioners responded to the survey. Eighty-nine percent (89%) of respondents performed LDR and 49% perform high-dose-rate brachytherapy. The median number of years of experience for LDR brachytherapists increased from 5 to 10 years over the course of the 12 years since the preceding survey. Compared with the first ABS, a smaller proportion of respondents received formal brachytherapy residency training (43% vs. 56%) or formal "hands-on" brachytherapy training (15% vs. 63%). There has been a marked decline in the utilization of the Mick applicator (Mick Radio-Nuclear Instruments, Inc., Mount Vernon, NY, USA) (60% vs. 28%) and an increase in the use of stranded seeds (40% vs. 11%). Compliance with postimplant dosimetry was higher in the 2010 survey. This survey does suggest an evolution in the practice of LDR brachytherapy since 1998 and aids in identifying aspects that require further progress or investigation. ABS guidelines and other practice recommendations appear to impact the practice of brachytherapy. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

In vivo dosimetry using a linear Mosfet-array dosimeter to determine the urethra dose in 125I permanent prostate implants.

PubMed

Bloemen-van Gurp, Esther J; Murrer, Lars H P; Haanstra, Björk K C; van Gils, Francis C J M; Dekker, Andre L A J; Mijnheer, Ben J; Lambin, Philippe

2009-01-01

In vivo dosimetry during brachytherapy of the prostate with (125)I seeds is challenging because of the high dose gradients and low photon energies involved. We present the results of a study using metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to evaluate the dose in the urethra after a permanent prostate implantation procedure. Phantom measurements were made to validate the measurement technique, determine the measurement accuracy, and define action levels for clinical measurements. Patient measurements were performed with a MOSFET array in the urinary catheter immediately after the implantation procedure. A CT scan was performed, and dose values, calculated by the treatment planning system, were compared to in vivo dose values measured with MOSFET dosimeters. Corrections for temperature dependence of the MOSFET array response and photon attenuation in the catheter on the in vivo dose values are necessary. The overall uncertainty in the measurement procedure, determined in a simulation experiment, is 8.0% (1 SD). In vivo dose values were obtained for 17 patients. In the high-dose region (> 100 Gy), calculated and measured dose values agreed within 1.7% +/- 10.7% (1 SD). In the low-dose region outside the prostate (< 100 Gy), larger deviations occurred. MOSFET detectors are suitable for in vivo dosimetry during (125)I brachytherapy of prostate cancer. An action level of +/- 16% (2 SD) for detection of errors in the implantation procedure is achievable after validation of the detector system and measurement conditions.

Application of heat pipe technology in permanent mold casting of nonferrous alloys

NASA Astrophysics Data System (ADS)

Elalem, Kaled

The issue of mold cooling is one, which presents a foundry with a dilemma. On the one hand; the use of air for cooling is safe and practical, however, it is not very effective and high cost. On the other hand, water-cooling can be very effective but it raises serious concerns about safety, especially with a metal such as magnesium. An alternative option that is being developed at McGill University uses heat pipe technology to carry out the cooling. The experimental program consisted of designing a permanent mold to produce AZ91E magnesium alloy and A356 aluminum alloy castings with shrinkage defects. Heat pipes were then used to reduce these defects. The heat pipes used in this work are novel and are patent pending. They are referred to as McGill Heat Pipes. Computer modeling was used extensively in designing the mold and the heat pipes. Final designs for the mold and the heat pipes were chosen based on the modeling results. Laboratory tests of the heat pipe were performed before conducting the actual experimental plan. The laboratory testing results verified the excellent performance of the heat pipes as anticipated by the model. An industrial mold made of H13 tool steel was constructed to cast nonferrous alloys. The heat pipes were installed and initial testing and actual industrial trials were conducted. This is the first time where a McGill heat pipe was used in an industrial permanent mold casting process for nonferrous alloys. The effects of cooling using heat pipes on AZ91E and A356 were evaluated using computer modeling and experimental trials. Microstructural analyses were conducted to measure the secondary dendrite arm spacing, SDAS, and the grain size to evaluate the cooling effects on the castings. The modeling and the experimental results agreed quite well. The metallurgical differences between AZ91E and A356 were investigated using modeling and experimental results. Selected results from modeling, laboratory and industrial trials are presented. The results show a promising future for heat pipe technology in cooling permanent molds for the casting of nonferrous alloys.

Does fluoride in drinking water delay tooth eruption?

PubMed

Jolaoso, Ismail Adeyemi; Kumar, Jayanth; Moss, Mark E

2014-01-01

The objectives of this study are to determine the effect of fluoride exposure on permanent tooth eruption patterns as well as to understand its effect on caries attack rate by accounting for the number of erupted tooth surfaces. We analyzed data from the 1986-1987 National Survey of Oral Health of US Schoolchildren to determine the mean number of erupted permanent teeth and permanent first molars according to fluoride level in drinking water. The analysis included 13,348 children aged 5-17 years with a history of single residence. We also estimated the attack rate (decayed, missing, and filled surfaces/surfaces at risk) for fluoride deficient, suboptimal, and optimally fluoridated areas adjusting for covariates. Multivariable statistical analyses were performed to control for potential confounders. By age 7, almost all permanent first molars had erupted. The adjusted mean number of erupted permanent first molars per child were 3.81, 3.67, and 3.92 in areas with <0.3, 0.3-<0.7, and 0.7-1.2 ppm of fluoride, respectively. The adjusted caries attack rate in the first permanent molars among 5- to 17-year-old children was 93, 81, and 78 per 1,000 surfaces in fluoride deficient, suboptimal, and optimally fluoridated areas, respectively (P < 0.0001). This pattern of higher first molar attack rate among children in the fluoride-deficient communities was also observed in all erupted teeth. Exposure to fluoride in drinking water did not delay the eruption of permanent teeth. The observed difference in dental caries experience among children exposed to different fluoride levels could not be explained by the timing of eruption of permanent teeth. © 2014 American Association of Public Health Dentistry.

Use of the asphalt pavement analyzer to study in-service asphalt mixture performance.

DOT National Transportation Integrated Search

2004-12-30

Permanent deformation or rutting is a major hot mix asphalt (HMA) performance distress. Implementation of the : Superior Performing Asphalt Pavement (Superpave) HMA mix design system was due, in part, to limit HMA rutting. : Along with the Superpave ...

Use of the Asphalt Pavement Analyzer to study in-service asphalt mixture performance

DOT National Transportation Integrated Search

2004-12-30

Permanent deformation or rutting is a major hot mix asphalt (HMA) performance distress. Implementation of the Superior Performing Asphalt Pavement (Superpave) HMA mix design system was due, in part, to limit HMA rutting. Along with the Superpave syst...

Performance Assessment of the 3M Combat Arms Generation 4.0 Tactical Military Shooter’s Ear Plug

DTIC Science & Technology

2016-06-24

blast , impulsive noise attenuation, REAT, IPIL 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF...fire could eventually result in permanent hearing loss. Noise exposures from larger weapons and blasts could instantly cause permanent hearing loss... noise . The general approach for this assessment was to use American National Standards Institute (ANSI) measurement procedures for continuous

Influence of lateral displacement on the levitation performance of a magnetized bulk high-Tc superconductor magnet

NASA Astrophysics Data System (ADS)

Liu, W.; Wang, J. S.; Ma, G. T.; Zheng, J.; Tuo, X. G.; Li, L. L.; Ye, C. Q.; Liao, X. L.; Wang, S. Y.

2012-03-01

Compared with the permanent magnet, the magnetized bulk high-Tc superconductor magnet (MBSCM) can trap higher magnetic field due to its strong flux pinning ability, so it is a good candidate to improve the levitation performance of high-Tc superconductive (HTS) maglev system. The trapped magnetic flux of a MBSCM is sustained by the inductive superconducting current produced by the magnetizing process and is susceptible to the current intensity as well as configuration. In the HTS maglev system, the lateral displacement is an important process to change the superconducting current within a MBSCM and then affects its levitation performance, which is essential for the traffic ability in curve-way, the loading capacity of lateral impact and so on. The research about influence of lateral displacement on the levitation performance of MBSCM is necessary when MBSCM is applied on the HTS maglev vehicle. The experimental investigations about the influence of lateral displacement on the levitation performance of a MBSCM with different trapped fluxes and applied fields are processed in this article. The analyses and conclusions of this article are useful for the practical application of MBSCM in HTS maglev system.

30 CFR 937.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... § 937.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 912.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... § 912.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 941.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... DAKOTA § 941.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 912.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... § 912.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 922.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... § 922.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 941.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... DAKOTA § 941.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 912.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... § 912.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 947.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... § 947.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 933.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... CAROLINA § 933.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 937.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... § 937.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 939.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... ISLAND § 939.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 905.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-In situ... § 905.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 910.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... § 910.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 921.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... MASSACHUSETTS § 921.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 942.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-In situ... § 942.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 939.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... ISLAND § 939.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 933.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... CAROLINA § 933.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 921.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... MASSACHUSETTS § 921.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 903.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-In situ... § 903.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, applies to any person who conducts surface coal mining...

30 CFR 933.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... CAROLINA § 933.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 942.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-In situ... § 942.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 933.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... CAROLINA § 933.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 922.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... § 922.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 910.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... § 910.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 937.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... § 937.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 922.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... § 922.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 921.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... MASSACHUSETTS § 921.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 942.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-In situ... § 942.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 942.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-In situ... § 942.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 939.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... ISLAND § 939.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 947.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... § 947.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 939.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... ISLAND § 939.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 912.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... § 912.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 922.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... § 922.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 905.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-In situ... § 905.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 905.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-In situ... § 905.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 941.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... DAKOTA § 941.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 903.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-In situ... § 903.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, applies to any person who conducts surface coal mining...

30 CFR 939.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... ISLAND § 939.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 937.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... § 937.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 942.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-In situ... § 942.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 905.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-In situ... § 905.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 903.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-In situ... § 903.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, applies to any person who conducts surface coal mining...

30 CFR 933.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Special performance standards-in situ... CAROLINA § 933.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 905.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-In situ... § 905.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts surface coal...

30 CFR 947.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... § 947.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 941.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... DAKOTA § 941.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 947.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Special performance standards-in situ... § 947.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 947.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-in situ... § 947.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 937.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... § 937.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 903.828 - Special performance standards-In situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-In situ... § 903.828 Special performance standards—In situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, applies to any person who conducts surface coal mining...

30 CFR 910.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Special performance standards-in situ... § 910.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...

30 CFR 921.828 - Special performance standards-in situ processing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Special performance standards-in situ... MASSACHUSETTS § 921.828 Special performance standards—in situ processing. Part 828 of this chapter, Special Permanent Program Performance Standards—In Situ Processing, shall apply to any person who conducts in situ...