A Rare Bilateral Presentation of Multiple Dens Invaginatus, Shovel-Shaped Incisor and Talon Cusp With Mesiodens.

PubMed

Hegde, S; Jain, M; Shubha, A B

2014-01-01

The aim of this paper is to describe a unique and unusual case of concomitant appearance of morphological dental anomalies in the maxillary anterior region, along with its management in a patient with no systemic abnormality. This case report describes the clinical and radiographic features of talon cusp, dens invaginatus, shovel-shaped incisors and a supernumerary tooth occurring in a single patient, which is a rare presentation. All 4 permanent maxillary incisors had dens invaginatus, the permanent maxillary canines showed the presence of talon cusps, the permanent maxillary central incisors were shovel-shaped and an erupted mesiodens was also observed. Treatment included restorative, surgical and orthodontic approaches.

Professional Identity and Engagement among Newly Qualified Teachers in Times of Uncertainty

ERIC Educational Resources Information Center

Correa Gorospe, José Miguel; Martínez-Arbelaiz, Asunción; Fernández-Olaskoaga, Lorea

2018-01-01

Social, political and economic conditions shape a context of permanent flux where early childhood education teachers have to join the labour market and build their professional identity while facing numerous challenges. The aim of this study is to investigate the effects that a changing world and precarious job conditions can have on newly…

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

Permanent magnet assembly

DOEpatents

Chell, Jeremy; Zimm, Carl B.

2006-12-12

A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

Multiple-object permanence tracking: limitation in maintenance and transformation of perceptual objects.

PubMed

Saiki, Jun

2002-01-01

Research on change blindness and transsaccadic memory revealed that a limited amount of information is retained across visual disruptions in visual working memory. It has been proposed that visual working memory can hold four to five coherent object representations. To investigate their maintenance and transformation in dynamic situations, I devised an experimental paradigm called multiple-object permanence tracking (MOPT) that measures memory for multiple feature-location bindings in dynamic situations. Observers were asked to detect any color switch in the middle of a regular rotation of a pattern with multiple colored disks behind an occluder. The color-switch detection performance dramatically declined as the pattern rotation velocity increased, and this effect of object motion was independent of the number of targets. The MOPT task with various shapes and colors showed that color-shape conjunctions are not available in the MOPT task. These results suggest that even completely predictable motion severely reduces our capacity of object representations, from four to only one or two.

Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

DOEpatents

Doughty, Frank C.; Spencer, John E.

2000-12-19

In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.

A mobile ferromagnetic shape detection sensor using a Hall sensor array and magnetic imaging.

PubMed

Misron, Norhisam; Shin, Ng Wei; Shafie, Suhaidi; Marhaban, Mohd Hamiruce; Mailah, Nashiren Farzilah

2011-01-01

This paper presents a mobile Hall sensor array system for the shape detection of ferromagnetic materials that are embedded in walls or floors. The operation of the mobile Hall sensor array system is based on the principle of magnetic flux leakage to describe the shape of the ferromagnetic material. Two permanent magnets are used to generate the magnetic flux flow. The distribution of magnetic flux is perturbed as the ferromagnetic material is brought near the permanent magnets and the changes in magnetic flux distribution are detected by the 1-D array of the Hall sensor array setup. The process for magnetic imaging of the magnetic flux distribution is done by a signal processing unit before it displays the real time images using a netbook. A signal processing application software is developed for the 1-D Hall sensor array signal acquisition and processing to construct a 2-D array matrix. The processed 1-D Hall sensor array signals are later used to construct the magnetic image of ferromagnetic material based on the voltage signal and the magnetic flux distribution. The experimental results illustrate how the shape of specimens such as square, round and triangle shapes is determined through magnetic images based on the voltage signal and magnetic flux distribution of the specimen. In addition, the magnetic images of actual ferromagnetic objects are also illustrated to prove the functionality of mobile Hall sensor array system for actual shape detection. The results prove that the mobile Hall sensor array system is able to perform magnetic imaging in identifying various ferromagnetic materials.

A Mobile Ferromagnetic Shape Detection Sensor Using a Hall Sensor Array and Magnetic Imaging

PubMed Central

Misron, Norhisam; Shin, Ng Wei; Shafie, Suhaidi; Marhaban, Mohd Hamiruce; Mailah, Nashiren Farzilah

2011-01-01

This paper presents a Mobile Hall Sensor Array system for the shape detection of ferromagnetic materials that are embedded in walls or floors. The operation of the Mobile Hall Sensor Array system is based on the principle of magnetic flux leakage to describe the shape of the ferromagnetic material. Two permanent magnets are used to generate the magnetic flux flow. The distribution of magnetic flux is perturbed as the ferromagnetic material is brought near the permanent magnets and the changes in magnetic flux distribution are detected by the 1-D array of the Hall sensor array setup. The process for magnetic imaging of the magnetic flux distribution is done by a signal processing unit before it displays the real time images using a netbook. A signal processing application software is developed for the 1-D Hall sensor array signal acquisition and processing to construct a 2-D array matrix. The processed 1-D Hall sensor array signals are later used to construct the magnetic image of ferromagnetic material based on the voltage signal and the magnetic flux distribution. The experimental results illustrate how the shape of specimens such as square, round and triangle shapes is determined through magnetic images based on the voltage signal and magnetic flux distribution of the specimen. In addition, the magnetic images of actual ferromagnetic objects are also illustrated to prove the functionality of Mobile Hall Sensor Array system for actual shape detection. The results prove that the Mobile Hall Sensor Array system is able to perform magnetic imaging in identifying various ferromagnetic materials. PMID:22346653

Crystallinity as a tunable switch of poly(L-lactide) shape memory effects.

PubMed

Sobota, Michał; Jurczyk, Sebastian; Kwiecień, Michał; Smola-Dmochowska, Anna; Musioł, Marta; Domański, Marian; Janeczek, Henryk; Kawalec, Michał; Kurcok, Piotr

2017-02-01

Materials with shape memory effect (SME) have already been widely used in the medical field. The interesting part of this group is represented by double function materials. The bioresorption and SME ability are common in polyesters implants. The first information about vascular stent made of bioresorbable polyester with SME was published in 2000. However, there are not many investigations about SME control of elements in the aspect of material processing. In the present work, the ability to control the shape memory (SM) of bioresorbable and semicrystalline poly(L-lactide) (PLLA) is investigated. The studies are based on the unexpected effect of material orientation which was demonstrated even at low percentage deformation in crystallized mould injected material. The presented studies revealed that the different degrees of crystallinity obtained during processing might be a useful switch to create a tailored SME for a specific application. The prepared samples of variable morphology revealed a possibility to control the value of material stress during permanent shape recovery. The degree of shape recovery of the prepared samples was also controlable. The highest stress value observed during permanent shape recovery reached 10MPa for the sample annealed 60min at 115°C even when the sample was only deformed in 8%. The other significant aspect of this work is to present the problem of slow crystallization of the material during and after processing (cooling rate) as well as the possibility of negative SME change during the shelf life of the fabric. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

An Analytical Model for Non-Uniform Magnetic Field Effects on Two-Dimensional Laminar Jet Diffusion Flames

NASA Technical Reports Server (NTRS)

Calvert, M. E.; Baker, J.; Saito, K.; VanderWal, R. L.

2001-01-01

In 1846, Michael Faraday found that permanent magnets could cause candle flames to deform into equatorial disks. He believed that the change in flame shape was caused by the presence of charged particles within the flames interacting with the magnetic fields. Later researchers found that the interaction between the flame ions and the magnetic fields were much too small to cause the flame deflection. Through a force analysis, von Engel and Cozens showed that the change in the flame shape could be attributed to the diamagnetic flame gases in the paramagnetic atmosphere. Paramagnetism occurs in materials composed of atoms with permanent magnetic dipole moments. In the presence of magnetic field gradients, the atoms align with the magnetic field and are drawn into the direction of increasing magnetic field. Diamagnetism occurs when atoms have no net magnetic dipole moment. In the presence of magnetic gradient fields, diamagnetic substances are repelled towards areas of decreasing magnetism. Oxygen is an example of a paramagnetic substance. Nitrogen, carbon monoxide and dioxide, and most hydrocarbon fuels are examples of diamagnetic substances. In order to evaluate the usefulness of these magnets in altering flame behavior, a study has been undertaken to develop an analytical model to describe the change in the flame length of a laminar diffusion jet in the presence of a nonuniform magnetic field.

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

The postnatal development of the temporal part of the human temporomandibular joint. A quantitative study on skulls.

PubMed

Dibbets, J M; Dijkman, G E

1997-12-01

The morphology of the temporal part of the human temporomandibular joint (TMJ) changes drastically during postnatal development. The glenoid fossa will acquire its characteristic S shape and a tubercle will develop. The combined results of the literature and of this study allow a reconstruction of the actual growth processes. The roof of the glenoid fossa appears to enlarge forward by remodeling while sagittal and vertical growth is mainly achieved by deposition at the top of the tubercle. These latter changes result in a steeper slope of the eminence and take place in 3 phases, parallelling the eruption of the first incisors, the permanent first molars and the permanent second molars. While the zygomatic arch thickens by deposition at all surfaces, it also remodels downward relative to the external meatus. As a result, the neonate anulus occupies a lower position relative to this arch than does the adult meatus.

The shape-memory effect in ionic elastomers: fixation through ionic interactions.

PubMed

González-Jiménez, Antonio; Malmierca, Marta A; Bernal-Ortega, Pilar; Posadas, Pilar; Pérez-Aparicio, Roberto; Marcos-Fernández, Ángel; Mather, Patrick T; Valentín, Juan L

2017-04-19

Shape-memory elastomers based on a commercial rubber cross-linked by both ionic and covalent bonds have been developed. The elastomeric matrix was a carboxylated nitrile rubber (XNBR) vulcanized with magnesium oxide (MgO) providing ionic interactions that form hierarchical structures. The so-named ionic transition is used as the unique thermal transition responsible for the shape-memory effect (SME) in these elastomers. These ionic interactions fix the temporary shape due to their behavior as dynamic cross-links with temperature changes. Covalent cross-links were incorporated with the addition of different proportions of dicumyl peroxide (DCP) to the ionic elastomer to establish and recover the permanent shape. In this article, the SME was modulated by modifying the degree of covalent cross-linking, while keeping the ionic contribution constant. In addition, different programming parameters, such as deformation temperature, heating/cooling rate, loading/unloading rate and percentage of tensile strain, were evaluated for their effects on shape-memory behavior.

Tooth shape optimization of brushless permanent magnet motors for reducing torque ripples

NASA Astrophysics Data System (ADS)

Hsu, Liang-Yi; Tsai, Mi-Ching

2004-11-01

This paper presents a tooth shape optimization method based on a generic algorithm to reduce the torque ripple of brushless permanent magnet motors under two different magnetization directions. The analysis of this design method mainly focuses on magnetic saturation and cogging torque and the computation of the optimization process is based on an equivalent magnetic network circuit. The simulation results, obtained from the finite element analysis, are used to confirm the accuracy and performance. Finite element analysis results from different tooth shapes are compared to show the effectiveness of the proposed method.

Shape forming by thermal expansion mismatch and shape memory locking in polymer/elastomer laminates

NASA Astrophysics Data System (ADS)

Yuan, Chao; Ding, Zhen; Wang, T. J.; Dunn, Martin L.; Qi, H. Jerry

2017-10-01

This paper studies a novel method to fabricate three-dimensional (3D) structure from 2D thermo-responsive shape memory polymer (SMP)/elastomer bilayer laminate. In this method, the shape change is actuated by the thermal mismatch strain between the SMP and the elastomer layers upon heating. However, the glass transition behavior of the SMP locks the material into a new 3D shape that is stable even upon cooling. Therefore, the second shape becomes a new permanent shape of the laminate. A theoretical model that accounts for the temperature-dependent thermomechanical behavior of the SMP material and thermal mismatch strain between the two layers is developed to better understand the underlying physics. Model predictions and experiments show good agreement and indicate that the theoretical model can well predict the bending behavior of the bilayer laminate. The model is then used in the optimal design of geometrical configuration and material selection. The latter also illustrates the requirement of thermomechanical behaviors of the SMP to lock the shape. Based on the fundamental understandings, several self-folding structures are demonstrated by the bilayer laminate design.

A Self-Propelled Wheel for Wheeled Vehicles.

DTIC Science & Technology

1996-09-05

embodiments of both types, in 16 general the axial permanent magnet motors feature a stator disk, 17 or drum, with a central opening and electrical...6 In general, in radial permanent magnet motors , the stator is 7 annularly-shaped and is concentrically disposed around a 8 generally cylindrically...is to provide a motor 6 assembly which is more efficient than the presently available 7 axial permanent magnet motors and radial permanent magnet motors 8

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.

High Cycle-life Shape Memory Polymer at High Temperature

PubMed Central

Kong, Deyan; Xiao, Xinli

2016-01-01

High cycle-life is important for shape memory materials exposed to numerous cycles, and here we report shape memory polyimide that maintained both high shape fixity (Rf) and shape recovery (Rr) during the more than 1000 bending cycles tested. Its critical stress is 2.78 MPa at 250 °C, and the shape recovery process can produce stored energy of 0.218 J g−1 at the efficiency of 31.3%. Its high Rf is determined by the large difference in storage modulus at rubbery and glassy states, while the high Rr mainly originates from its permanent phase composed of strong π-π interactions and massive chain entanglements. Both difference in storage modulus and overall permanent phase were preserved during the bending deformation cycles, and thus high Rf and Rr were observed in every cycle and the high cycle-life will expand application areas of SMPs enormously. PMID:27641148

A MEMS torsion magnetic sensor with reflective blazed grating integration

NASA Astrophysics Data System (ADS)

Long, Liang; Zhong, Shaolong

2016-07-01

A novel magnetic sensor based on a permanent magnet and blazed grating is presented in this paper. The magnetic field is detected by measuring the diffracted wavelength of the blazed grating which is changed by the torsion motion of a torsion sensitive micro-electromechanical system (MEMS) structure with a permanent magnet attached. A V-shape grating structure is obtained by wet etching on a (1 0 0) SOI substrate. When the magnet is magnetized in different directions, the in-plane or out-of-plane magnetic field is detected by a sensor. The MEMS magnetic sensor with a permanent magnet is fabricated after analytical design and bulk micromachining processes. The magnetic-sensing capability of the sensor is tested by fiber-optic detection system. The result shows the sensitivities of the in-plane and out-of-plane magnetic fields are 3.6 pm μT-1 and 5.7 pm μT-1, respectively. Due to utilization of the permanent magnet and fiber-optic detection, the sensor shows excellent capability of covering the high-resolution detection of low-frequency signals. In addition, the sensitive direction of the magnetic sensor can be easily switched by varying the magnetized direction of the permanent magnet, which offers a simple way to achieve tri-axis magnetic sensor application.

Compression Molding and Novel Sintering Treatments for Alnico Type-8 Permanent Magnets in Near-Final Shape with Preferred Orientation

NASA Astrophysics Data System (ADS)

Kassen, Aaron G.; White, Emma M. H.; Tang, Wei; Hu, Liangfa; Palasyuk, Andriy; Zhou, Lin; Anderson, Iver E.

2017-09-01

Economic uncertainty in the rare earth (RE) permanent magnet marketplace, as well as in an expanding electric drive vehicle market that favors permanent magnet alternating current synchronous drive motors, motivated renewed research in RE-free permanent magnets like "alnico," an Al-Ni-Co-Fe alloy. Thus, high-pressure, gas-atomized isotropic type-8H pre-alloyed alnico powder was compression molded with a clean burn- out binder to near-final shape and sintered to density >99% of cast alnico 8 (full density of 7.3 g/cm3). To produce aligned sintered alnico magnets for improved energy product and magnetic remanence, uniaxial stress was attempted to promote controlled grain growth, avoiding directional solidification that provides alignment in alnico 9. Successful development of solid-state powder processing may enable anisotropically aligned alnico magnets with enhanced energy density to be mass-produced.

Analysis of the semi-permanent house in Merauke city in terms of aesthetic value in architecture

NASA Astrophysics Data System (ADS)

Topan, Anton; Octavia, Sari; Soleman, Henry

2018-05-01

Semi permanent houses are also used called “Rumah Kancingan” is the houses that generally exist in the Merauke city. Called semi permanent because the main structure use is woods even if the walls uses bricks. This research tries to analyze more about Semi permanent house in terms of aesthethics value. This research is a qualitative research with data collection techniques using questionnaire method and direct observation field and study of literature. The result of questionnaire data collection then processed using SPSS to get the influence of independent variable against the dependent variable and found that color, ornament, shape of the door-window and shape of roof (independent) gives 97,1% influence to the aesthetics of the Semi permanent house and based on the output coefficient SPSS obtained that the dependent variable has p-value < 0.05 which means independent variables have an effect on significant to aesthetic variable. For variables of semi permanent and wooden structure gives an effect of 98,6% to aesthetics and based on the result of SPSS coefficient it is found that free variable has p-value < 0.05 which means independent variables have an effect on significant to aesthetic variable.

Design and analysis of a flux intensifying permanent magnet embedded salient pole wind generator

NASA Astrophysics Data System (ADS)

Guo, Yujing; Jin, Ping; Lin, Heyun; Yang, Hui; Lyu, Shukang

2018-05-01

This paper presents an improved flux intensifying permanent magnet embedded salient pole wind generator (FI-PMESPWG) with mirror symmetrical magnetizing directions permanent magnet (PM) for improving generator's performances. The air-gap flux densities, the output voltage, the cogging torque and the d- and q-axis inductances of FI-PMESPWG are all calculated and analyzed by using the finite element method (FEM). To highlight the advantages of the proposed FI-PMESPWG, an original permanent magnet embedded salient pole wind generator (PMESPWG) model is adopted for comparison under the same operating conditions. The calculating results show that the air-gap flux densities of FI-PMESPWG are intensified with the same magnet amounts because the PMs are set in a form of V shape in each pole. The difference between d-axis inductance and q-axis inductance of the proposed FI-PMESPWG is reduced. Thus, the output power of the proposed FI-PMESPWG reaches a higher value than that of the original PMESPWG at the same current phase angle. The cogging torque is diminished because the flux path is changed. All the analysis results indicate that the electromagnetic characteristics of the proposed FI-PMESPWG are significantly better than that of the original PMESPWG.

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.

A novel flux-switching permanent magnet machine with v-shaped magnets

NASA Astrophysics Data System (ADS)

Zhao, Guishu; Hua, Wei

2017-05-01

In this paper, firstly a novel 6-stator-coil/17-rotor-pole (6/17) flux-switching permanent magnet (FSPM) machine with V-shaped magnets, deduced from conventional 12/17 FSPM machines is proposed to achieve more symmetrical phase back-electromotive force (back-EMF), and smaller torque ripple by comparing with an existing 6/10 V-shaped FSPM machine. Then, to obtain larger electromagnetic torque, less torque ripple, and easier mechanical processing, two improved variants based on the original 6/17 V-shaped topology are proposed. For the first variant, the separate stator-core segments located on the stator yoke are connected into a united stator yoke, while for the second variant the stator core is a whole entity by adding magnetic bridges at the ends of permanent magnets (PMs). Consequently, the performances of the three 6/17 V-shaped FSPM machines, namely, the original one and the two variants, are conducted by finite element analysis (FEA). The results reveal that the first variant exhibits significantly larger torque and considerably improved torque per magnet volume, i.e., the magnet utilization ratio than the original one, and the second variant exhibits the smallest torque ripple, least total harmonic distribution (THD) of phase back-EMF, and easiest mechanical processing for manufacturing.

Effective treatment of permanent tattoos with combustible particles due to blast injuries with a V-shaped device.

PubMed

Kalbermatten, D F; Wettstein, R; Haug, M; du Croo de Jongh, N T; Pierer, G

2006-01-01

Permanent tattooing due to blast injuries is a rare condition. Treatment with various different methods often yields unsatisfactory results. An innovative way to remove permanent traumatic tattoos is presented. A normal curettage blade is simply compressed with a pincer in order to create the new device. This V-shaped blade was used for surgical excision of the particles. No suture material or special dressing was used. Four patients with multiple explosive tattoos on the face were treated with the V-shaped knife. Due to the ease and speed of this method up to 300 particles were removed in one session. Histological analysis of the tissue samples showed deep dermal and subcutaneous particle location. At follow-up transient hypopigmentation but only minimal scarring was seen. Patients suffered less from itching, a chief complaint preoperatively, and aesthetic appearance of the facial skin was improved. In conclusion, treatment of traumatic tattoos with the V-shaped knife is effective, results in minimal scaring and restores the natural colour of the skin because the particle is completely removed. It is a promising method for treating multiple deep skin inclusions.

Compression Molding and Novel Sintering Treatments for Alnico Type-8 Permanent Magnets in Near-Final Shape with Preferred Orientation

DOE PAGES

Kassen, Aaron G.; White, Emma M. H.; Tang, Wei; ...

2017-07-14

We present economic uncertainty in the rare earth (RE) permanent magnet marketplace, as well as in an expanding electric drive vehicle market that favors permanent magnet alternating current synchronous drive motors, motivated renewed research in RE-free permanent magnets like “alnico,” an Al-Ni-Co-Fe alloy. Thus, high-pressure, gas-atomized isotropic type-8H pre-alloyed alnico powder was compression molded with a clean burn-out binder to near-final shape and sintered to density >99% of cast alnico 8 (full density of 7.3 g/cm 3). To produce aligned sintered alnico magnets for improved energy product and magnetic remanence, uniaxial stress was attempted to promote controlled grain growth, avoidingmore » directional solidification that provides alignment in alnico 9. Lastly, successful development of solid-state powder processing may enable anisotropically aligned alnico magnets with enhanced energy density to be mass-produced.« less

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.

Preparation and characterization of triple shape memory composite foams.

PubMed

Nejad, Hossein Birjandi; Baker, Richard M; Mather, Patrick T

2014-10-28

Foams prepared from shape memory polymers (SMPs) offer the potential for low density materials that can be triggered to deploy with a large volume change, unlike their solid counterparts that do so at near-constant volume. While examples of shape memory foams have been reported in the past, they have been limited to dual SMPs: those polymers featuring one switching transition between an arbitrarily programmed shape and a single permanent shape established by constituent crosslinks. Meanwhile, advances by SMP researchers have led to several approaches toward triple- or multi-shape polymers that feature more than one switching phase and thus a multitude of temporary shapes allowing for a complex sequence of shape deployments. Here, we report the design, preparation, and characterization of a triple shape memory polymeric foam that is open cell in nature and features a two phase, crosslinked SMP with a glass transition temperature of one phase at a temperature lower than a melting transition of the second phase. The soft materials were observed to feature high fidelity, repeatable triple shape behavior, characterized in compression and demonstrated for complex deployment by fixing a combination of foam compression and bending. We further explored the wettability of the foams, revealing composition-dependent behavior favorable for future work in biomedical investigations.

Ferrofluid based micro-electrical energy harvesting

NASA Astrophysics Data System (ADS)

Purohit, Viswas; Mazumder, Baishakhi; Jena, Grishma; Mishra, Madhusha; Materials Department, University of California, Santa Barbara, CA93106 Collaboration

2013-03-01

Innovations in energy harvesting have seen a quantum leap in the last decade. With the introduction of low energy devices in the market, micro energy harvesting units are being explored with much vigor. One of the recent areas of micro energy scavenging is the exploitation of existing vibrational energy and the use of various mechanical motions for the same, useful for low power consumption devices. Ferrofluids are liquids containing magnetic materials having nano-scale permanent magnetic dipoles. The present work explores the possibility of the use of this property for generation of electricity. Since the power generation is through a liquid material, it can take any shape as well as response to small acceleration levels. In this work, an electromagnet-based micropower generator is proposed to utilize the sloshing of the ferrofluid within a controlled chamber which moves to different low frequencies. As compared to permanent magnet units researched previously, ferrofluids can be placed in the smallest of containers of different shapes, thereby giving an output in response to the slightest change in motion. Mechanical motion from 1- 20 Hz was able to give an output voltage in mV's. In this paper, the efficiency and feasibility of such a system is demonstrated.

Shape-memory surfaces for cell mechanobiology

PubMed Central

Ebara, Mitsuhiro

2015-01-01

Shape-memory polymers (SMPs) are a new class of smart materials, which have the capability to change from a temporary shape ‘A’ to a memorized permanent shape ‘B’ upon application of an external stimulus. In recent years, SMPs have attracted much attention from basic and fundamental research to industrial and practical applications due to the cheap and efficient alternative to well-known metallic shape-memory alloys. Since the shape-memory effect in SMPs is not related to a specific material property of single polymers, the control of nanoarchitecture of polymer networks is particularly important for the smart functions of SMPs. Such nanoarchitectonic approaches have enabled us to further create shape-memory surfaces (SMSs) with tunable surface topography at nano scale. The present review aims to bring together the exciting design of SMSs and the ever-expanding range of their uses as tools to control cell functions. The goal for these endeavors is to mimic the surrounding mechanical cues of extracellular environments which have been considered as critical parameters in cell fate determination. The untapped potential of SMSs makes them one of the most exciting interfaces of materials science and cell mechanobiology. PMID:27877747

Multidimensional stability of traveling fronts in combustion and non-KPP monostable equations

NASA Astrophysics Data System (ADS)

Bu, Zhen-Hui; Wang, Zhi-Cheng

2018-02-01

This paper is concerned with the multidimensional stability of traveling fronts for the combustion and non-KPP monostable equations. Our study contains two parts: in the first part, we first show that the two-dimensional V-shaped traveling fronts are asymptotically stable in R^{n+2} with n≥1 under any (possibly large) initial perturbations that decay at space infinity, and then, we prove that there exists a solution that oscillates permanently between two V-shaped traveling fronts, which implies that even very small perturbations to the V-shaped traveling front can lead to permanent oscillation. In the second part, we establish the multidimensional stability of planar traveling front in R^{n+1} with n≥1.

Ultrasonic monitoring of pitting corrosion

NASA Astrophysics Data System (ADS)

Jarvis, A. J. C.; Cegla, F. B.; Bazaz, H.; Lozev, M.

2013-01-01

Exposure to corrosive substances in high temperature environments can cause damage accumulation in structural steels, particularly in the chemical and petrochemical industries. The interaction mechanisms are complex and varied; however initial damage propagation often manifests itself in the form of localized areas of increased material loss. Recent development of an ultrasonic wall thickness monitoring sensor capable of withstanding temperatures in excess of 500°C has allowed permanent monitoring within such hostile environments, providing information on how the shape of a pulse which has reflected from a corroding surface can change over time. Reconstructing localized corrosion depth and position may be possible by tracking such changes in reflected pulse shape, providing extra information on the state of the backwall and whether process conditions should be altered to increase plant life. This paper aims to experimentally investigate the effect certain localized features have on reflected pulse shape by `growing' artificial defects into the backwall while wall thickness is monitored using the sensor. The size and complexity of the three dimensional scattering problem lead to the development of a semi-analytical simulation based on the distributed point source method (DPSM) which is capable of simulating pulse reflection from complex surfaces measuring approximately 17×10λ Comparison to experimental results show that amplitude changes are predicted to within approximately 1dB and that pulse shape changes are accurately modelled. All experiments were carried out at room temperature, measurements at high temperature will be studied in the future.

Control of cytoskeletal mechanics by extracellular matrix, cell shape, and mechanical tension

NASA Technical Reports Server (NTRS)

Wang, N.; Ingber, D. E.

1994-01-01

We have investigated how extracellular matrix (ECM) alters the mechanical properties of the cytoskeleton (CSK). Mechanical stresses were applied to integrin receptors on the apical surfaces of adherent endothelial cells using RGD-coated ferromagnetic microbeads (5.5-microns diameter) in conjunction with a magnetic twisting device. Increasing the number of basal cell-ECM contacts by raising the fibronectin (FN) coating density from 10 to 500 ng/cm2 promoted cell spreading by fivefold and increased CSK stiffness, apparent viscosity, and permanent deformation all by more than twofold, as measured in response to maximal stress (40 dyne/cm2). When the applied stress was increased from 7 to 40 dyne/cm2, the stiffness and apparent viscosity of the CSK increased in parallel, although cell shape, ECM contacts, nor permanent deformation was altered. Application of the same stresses over a lower number ECM contacts using smaller beads (1.4-microns diameter) resulted in decreased CSK stiffness and apparent viscosity, confirming that this technique probes into the depth of the CSK and not just the cortical membrane. When magnetic measurements were carried out using cells whose membranes were disrupted and ATP stores depleted using saponin, CSK stiffness and apparent viscosity were found to rise by approximately 20%, whereas permanent deformation decreased by more than half. Addition of ATP (250 microM) under conditions that promote CSK tension generation in membrane-permeabilized cells resulted in decreases in CSK stiffness and apparent viscosity that could be detected within 2 min after ATP addition, before any measurable change in cell size.(ABSTRACT TRUNCATED AT 250 WORDS).

Dual-rotor, radial-flux, toroidally-wound, permanent-magnet machine

DOEpatents

Qu, Ronghai; Lipo, Thomas A.

2005-08-02

The present invention provides a novel dual-rotor, radial-flux, toroidally-wound, permanent-magnet machine. The present invention improves electrical machine torque density and efficiency. At least one concentric surface-mounted permanent magnet dual-rotor is located inside and outside of a torus-shaped stator with back-to-back windings, respectively. The machine substantially improves machine efficiency by reducing the end windings and boosts the torque density by at least doubling the air gap and optimizing the machine aspect ratio.

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

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

Optimal current waveforms for brushless permanent magnet motors

NASA Astrophysics Data System (ADS)

Moehle, Nicholas; Boyd, Stephen

2015-07-01

In this paper, we give energy-optimal current waveforms for a permanent magnet synchronous motor that result in a desired average torque. Our formulation generalises previous work by including a general back-electromotive force (EMF) wave shape, voltage and current limits, an arbitrary phase winding connection, a simple eddy current loss model, and a trade-off between power loss and torque ripple. Determining the optimal current waveforms requires solving a small convex optimisation problem. We show how to use the alternating direction method of multipliers to find the optimal current in milliseconds or hundreds of microseconds, depending on the processor used, which allows the possibility of generating optimal waveforms in real time. This allows us to adapt in real time to changes in the operating requirements or in the model, such as a change in resistance with winding temperature, or even gross changes like the failure of one winding. Suboptimal waveforms are available in tens or hundreds of microseconds, allowing for quick response after abrupt changes in the desired torque. We demonstrate our approach on a simple numerical example, in which we give the optimal waveforms for a motor with a sinusoidal back-EMF, and for a motor with a more complicated, nonsinusoidal waveform, in both the constant-torque region and constant-power region.

Dovetail Rotor Construction For Permanent-Magnet Motors

NASA Technical Reports Server (NTRS)

Kintz, Lawrence J., Jr.; Puskas, William J.

1988-01-01

New way of mounting magnets in permanent-magnet, electronically commutated, brushless dc motors. Magnets wedge shaped, tapering toward center of rotor. Oppositely tapered pole pieces, electron-beam welded to rotor hub, retain magnets against centrifugal force generated by spinning rotor. To avoid excessively long electron-beam welds, pole pieces assembled in segments rather than single long bars.

Magnet pole shape design for reduction of thrust ripple of slotless permanent magnet linear synchronous motor with arc-shaped magnets considering end-effect based on analytical method

NASA Astrophysics Data System (ADS)

Shin, Kyung-Hun; Park, Hyung-Il; Kim, Kwan-Ho; Jang, Seok-Myeong; Choi, Jang-Young

2017-05-01

The shape of the magnet is essential to the performance of a slotless permanent magnet linear synchronous machine (PMLSM) because it is directly related to desirable machine performance. This paper presents a reduction in the thrust ripple of a PMLSM through the use of arc-shaped magnets based on electromagnetic field theory. The magnetic field solutions were obtained by considering end effect using a magnetic vector potential and two-dimensional Cartesian coordinate system. The analytical solution of each subdomain (PM, air-gap, coil, and end region) is derived, and the field solution is obtained by applying the boundary and interface conditions between the subdomains. In particular, an analytical method was derived for the instantaneous thrust and thrust ripple reduction of a PMLSM with arc-shaped magnets. In order to demonstrate the validity of the analytical results, the back electromotive force results of a finite element analysis and experiment on the manufactured prototype model were compared. The optimal point for thrust ripple minimization is suggested.

PCL-based Shape Memory Polymers with Variable PDMS Soft Segment Lengths

PubMed Central

Zhang, Dawei; Giese, Melissa L.; Prukop, Stacy L.; Grunlan, Melissa A.

2012-01-01

Thermoresponsive shape memory polymers (SMPs) are stimuli-responsive materials that return to their permanent shape from a temporary shape in response to heating. The design of new SMPs which obtain a broader range of properties including mechanical behavior is critical to realize their potential in biomedical as well as industrial and aerospace applications. To tailor the properties of SMPs, “AB networks” comprised of two distinct polymer components have been investigated but are overwhelmingly limited to those in which both components are organic. In this present work, we prepared inorganic-organic SMPs comprised of inorganic polydimethyl-siloxane (PDMS) segments of varying lengths and organic poly(ε-caprolactone) (PCL) segments. PDMS has a particularly low Tg (−125 °C) which makes it a particularly effective soft segment to tailor the mechanical properties of PCL-based SMPs. The SMPs were prepared via the rapid photocure of solutions of diacrylated PCL40-block-PDMSm-block-PCL40 macromers (m = 20, 37, 66 and 130). The resulting inorganic-organic SMP networks exhibited excellent shape fixity and recovery. By changing the PDMS segment length, the thermal, mechanical, and surface properties were systematically altered. PMID:22904597

Permanent tensions in organization.

PubMed

Jansson, Noora

2015-01-01

The purpose of this paper is to investigate the relationship between permanent tensions and organizational change. This study used paradox theory and a case study. The case organization is a public university hospital in Finland involving several stakeholders. The analysis suggests that the relationship between permanent tensions and organizational change is a paradox that is part of organizational reality. As an organization learns to live with its permanent tensions, the renewal paradox settles into equilibrium. When tensions are provoked, the paradox is disturbed until it finds a new balance. This flexible nature of the paradox is the force that keeps the different stakeholders simultaneously empowered to maintain their unique missions and cohesive in order to benefit from the larger synergy. This research suggests that identification and evaluation of each permanent tension within an organization is important when executing organizational change. The fact that certain tensions are permanent and cannot be solved may have an influence on how planned change initiatives are executed. The results show that permanent tensions may be harnessed for the benefit of an organizational change. This research demonstrates originality by offering an alternative view of tensions, a view which emphasizes not only their permanent and plural nature but their importance for enabling the organization to change at its own, non-disruptive pace. The research also proposes a new concept, the "renewal paradox", to enhance understanding of the relationship between permanent tensions and organizational change.

Tape functionality: sonographic tape characteristics and outcome after TVT incontinence surgery.

PubMed

Kociszewski, Jacek; Rautenberg, Oliver; Perucchini, Daniele; Eberhard, Jakob; Geissbühler, Verena; Hilgers, Reinhard; Viereck, Volker

2008-01-01

To investigate tension-free vaginal tape (TVT) position and shape using ultrasound (US) and correlate the findings to outcome. The results of TVT surgery were investigated in 72 women with urodynamic stress urinary incontinence. The main outcome parameters were US tape position in relation to the urethra and dynamic changes in TVT shape at rest and during straining. Sixty-two patients (86%) were continent, 6 (8%) significantly improved, and the operation failed in four cases (6%). The median tape position was at 66% of the urethral length measured by US. The median tape-urethra-lumen distance was 3.8 mm at rest. Tape placement in the upper or lower quarter of the urethra was associated with a higher failure rate. Tapes positioned less than 3 mm from the urethra significantly increased postoperative complications (P < 0.0001). The tape was flat at rest and curved during straining in 44 (61%) patients; 98% (43/44) of these women were continent after surgery. An unchanged tape shape was associated with a poorer outcome (P = 0.00038). Patients with a flat tape at rest and during straining failed in 25% and patients with a permanent curved shape in 10%. TVT position relative to the patient's urethra seems to play a role in treatment outcome. Outcome was best in patients with dynamic change in tape shape during straining and location of the tape at the junction between the lower and middle urethra and at least 3 mm from the urethral lumen. (c) 2008 Wiley-Liss, Inc.

Thin-plate spline analysis of the short- and long-term effects of rapid maxillary expansion.

PubMed

Franchi, Lorenzo; Baccetti, Tiziano; Cameron, Christopher G; Kutcipal, Elizabeth A; McNamara, James A

2002-04-01

The aim of this study was to investigate the short- and long-term effects induced by rapid maxillary expansion (RME) on the shape of the maxillary and circummaxillary structures by means of thin-plate spline (TPS) analysis. The sample consisted of 42 patients who were compared with a control sample of 20 subjects. The treated subjects underwent Haas-type RME, followed by fixed appliance therapy. Postero-anterior (PA) cephalograms were analysed for each treated subject at T1 (pre-treatment), T2 (immediate post-expansion), and T3 (long-term observation), and were available at T1 and T3 for the control group (CG). The mean age at T1 was 11 years and 10 months for both groups. The mean chronological ages at T3 were 20 years, 6 months for the treated group (TG) and 17 years, 8 months for the control group. The study focused on shape changes in the maxillary, nasal, zygomatic, and orbital regions. TPS analysis revealed significant shape changes in the TG. They consisted of an upward and lateral displacement of the two halves of the naso-maxillary complex as a result of active expansion in the short-term, and normalization of maxillary shape in the transverse dimension in the long-term (the initial transverse deficiency of the maxilla in the treated group was eliminated by RME therapy both in the short- and long-term). At the end of the observation period, the nasal cavities were larger when compared with both their pre-expansion configuration and the final configuration in the controls. RME with the Haas appliance appears to be an efficient therapeutic means to induce permanent favourable changes in the shape of the naso-maxillary complex.

Longitudinal changes in parental satisfaction: mixed dentition esthetics.

PubMed

Cannon, Hyrum M; Broffitt, Barbara; Levy, Steven M; Warren, John J

2010-01-01

This study's purpose was to report on parents' esthetic perceptions of their children's mixed dentition and parental satisfaction changes over time. A total of 376 parents completed esthetic questionnaires concerning satisfaction with their children's teeth at 9- and 11-years-old. Changes in esthetic perceptions were compared based on fluorosis, nonfluoride opacity status (evaluated at 9-years-old), and other factors. A total of 36% had definitive fluorosis on permanent maxillary incisors. Fluorosis (P=.003) and opacity (P=.02) status were significantly related to reduced likelihood of parental satisfaction at 11-years-old. Parents were less satisfied with overall tooth color at 11 vs 9-years-old (P=.045), but revealed no significant change in satisfaction with overall appearance (P=.17). Shape and color concerns increased (both P=.003), while spacing concerns decreased (P=.004). Parental satisfaction increases were associated with higher socioeconomic status (P=.03) and starting orthodontic treatment (P=.002), but changes were not significantly associated with fluorosis (P=.38) or opacities (P=.81). Parents were generally less satisfied with overall tooth color at 11 (vs 9) years old and had greater concerns about tooth shape and color, but fewer concerns with spacing. Improvement in parental satisfaction with overall appearance was related to higher socioeconomic status and having begun orthodontic treatment.

Effect of water content on specific heat capacity of porcine septum cartilage

NASA Astrophysics Data System (ADS)

Chae, Yongseok; Lavernia, Enrique J.; Wong, Brian J.

2002-06-01

The effect of water content on specific heat capacity was examined using temperature modulated Differential Scanning Calorimetry (TMDSC). This research was motivated in part by the development laser cartilage reshaping operations, which use photothermal heating to accelerate stress relaxation and shape change. Deposition of thermal energy leads to mechanical stress relaxation and redistribution of cartilage internal stresses, which may lead to a permanent shape change. The specific heat of cartilage specimens (dia: 3 mm and thickness 1-2 mm) was measured using a heating rate of 2 degree(s)C/min for conventional DSC and 2 degree(s)C/min with an amplitude 0.38-0.45 degree(s)C and a period 60-100 sec for TMDSC. The amount of water in cartilaginous tissue was determined using thermogravimetry analysis (TGA) under ambient conditions. In order to correlate changes in heat flow with alterations in cartilage mechanical behavior, dynamic mechanical temperature analysis (DMTA) was used to estimate the specific transition temperatures where stress relaxation occurs. With decreasing water content, we identified a phase transition that shifted to a higher temperature after 35-45% water content was measured. The phase transition energy increased from 0.12 J/g to 1.68 J/g after a 45% weight loss. This study is a preliminary investigation focused on understanding the mechanism of the stress relaxation of cartilage during heating. The energy requirement of such a transition estimated using TMDSC and temperature range, where cartilage shape changes likely occur, was estimated.

Magnetocaloric effect: permanent magnet array for generation of high magnetic fields

NASA Astrophysics Data System (ADS)

Lee, Seong-Jae; Kenkel, John; Jiles, David

2002-03-01

The magnetocaloric effect (MCE), the heating or cooling of magnetic materials in a magnetic field, is unusually large in the Gd_5(Si_xGe_1-x)4 alloy system. Normally the maximum in the MCE occurs at the Curie temperature (Tc) because the spin entropy change is a maximum. By suitable selection of the composition of this alloy system the Curie temperature can be changed over the range 25 K for x = 0 to 340 K for x =1, and the composition range around x = 0.5 exhibits the largest magnetocaloric effect. In order to increase the amount of heat exchanged the change in applied magnetic field should be as large as possible, and in this research values above 1.5 Tesla are suggested. We have studied a permanent magnet array based on NdFeB, which with a remanent magnetization of only 1.2 Tesla can still generate a magnetic flux density, or magnetic induction B of 2-3 Tesla. In order to generate the high magnetic induction in the absence of a power supply, a modified hollow cylindrical permanent magnet array (HCPMA) has been designed to produce the required strength of magnetic field. Soft magnetic materials including permalloy (NiFe) were used for focusing the magnetic field in the central region. The magnitude of the magnetic flux density at the center was about 2 Tesla. The magnitude and homogeneity of the magnetic field for this design are comparable with the conventional C-shaped yoke and HCPMA. This can be easily adapted for a low power rotary system in which the magnetocaloric material can be exposed alternately to high and low magnetic fields so that it can accept and reject heat from its surroundings.

Gap Junctional Blockade Stochastically Induces Different Species-Specific Head Anatomies in Genetically Wild-Type Girardia dorotocephala Flatworms

PubMed Central

Emmons-Bell, Maya; Durant, Fallon; Hammelman, Jennifer; Bessonov, Nicholas; Volpert, Vitaly; Morokuma, Junji; Pinet, Kaylinnette; Adams, Dany S.; Pietak, Alexis; Lobo, Daniel; Levin, Michael

2015-01-01

The shape of an animal body plan is constructed from protein components encoded by the genome. However, bioelectric networks composed of many cell types have their own intrinsic dynamics, and can drive distinct morphological outcomes during embryogenesis and regeneration. Planarian flatworms are a popular system for exploring body plan patterning due to their regenerative capacity, but despite considerable molecular information regarding stem cell differentiation and basic axial patterning, very little is known about how distinct head shapes are produced. Here, we show that after decapitation in G. dorotocephala, a transient perturbation of physiological connectivity among cells (using the gap junction blocker octanol) can result in regenerated heads with quite different shapes, stochastically matching other known species of planaria (S. mediterranea, D. japonica, and P. felina). We use morphometric analysis to quantify the ability of physiological network perturbations to induce different species-specific head shapes from the same genome. Moreover, we present a computational agent-based model of cell and physical dynamics during regeneration that quantitatively reproduces the observed shape changes. Morphological alterations induced in a genomically wild-type G. dorotocephala during regeneration include not only the shape of the head but also the morphology of the brain, the characteristic distribution of adult stem cells (neoblasts), and the bioelectric gradients of resting potential within the anterior tissues. Interestingly, the shape change is not permanent; after regeneration is complete, intact animals remodel back to G. dorotocephala-appropriate head shape within several weeks in a secondary phase of remodeling following initial complete regeneration. We present a conceptual model to guide future work to delineate the molecular mechanisms by which bioelectric networks stochastically select among a small set of discrete head morphologies. Taken together, these data and analyses shed light on important physiological modifiers of morphological information in dictating species-specific shape, and reveal them to be a novel instructive input into head patterning in regenerating planaria. PMID:26610482

Vibration and shape control of hinged light structures using electromagnetic forces

NASA Astrophysics Data System (ADS)

Matsuzaki, Yuji; Miyachi, Shigenobu; Sasaki, Toshiyuki

2003-08-01

This paper describes a new electromagnetic device for vibration control of a light-weighted deployable/retractable structure which consists of many small units connected with mechanical hinges. A typical example of such a structure is a solar cell paddle of an artificial satellite which is composed of many thin flexible blankets connected in series. Vibration and shape control of the paddle is not easy, because control force and energy do not transmit well between the blankets which are discretely connected by hinges with each other. The new device consists of a permanent magnet glued along an edge of a blanket and an electric current-conducting coil glued along an adjoining edge of another adjacent blanket. Conduction of the electric current in a magnetic field from the magnet generates an electromagnetic force on the coil. By changing the current in the coil, therefore, we may control the vibration and shape of the blankets. To confirm the effectiveness of the new device, constructing a simple paddle model consisting eight hinge- panels, we have carried out a model experiment of vibration and shape control of the paddle. In addition, a numerical simulation of vibration control of the hinge structure is performed to compare with measured data.

Frequency and variability of dental morphology in deciduous and permanent dentition of a Nasa indigenous group in the municipality of Morales, Cauca, Colombia.

PubMed

Díaz, Eider; García, Lorena; Hernández, Michelle; Palacio, Lesly; Ruiz, Diana; Velandia, Nataly; Villavicencio, Judy; Moreno, Freddy

2014-01-01

To determine the frequency, variability, sexual dimorphism and bilateral symmetry of fourteen dental crown traits in the deciduous and permanent dentition of 60 dental models (35 women and 25 men) obtained from a native, indigenous group of Nasa school children of the Musse Ukue group in the municipality of Morales, Department of Cauca, Colombia. This is a quantitative, descriptive, cross-sectional study that characterizes dental morphology by means of the systems for temporary dentition from Dahlberg (winging), and ASUDAS (crowding, reduction of hypocone, metaconule and cusp 6), Hanihara (central and lateral incisors in shovel-shape and cusp 7), Sciulli (double bit, layered fold protostylid, cusp pattern and cusp number) and Grine (Carabelli trait); and in permanent dentition from ASUDAS (Winging, crowding, central and lateral incisors in shovel-shape and double shovel-shape, Carabelli trait, hypocone reduction, metaconule, cusp pattern, cusp number, layered fold protostylid, cusp 6 and cusp 7). The most frequent dental crown features were the shovel-shaped form, grooved and fossa forms of the Carabelli trait, metaconule, cusp pattern Y6, layered fold, protostylid (point P) and cusp 6. Sexual dimorphism was not observed and there was bilateral symmetry in the expression of these features. The sample studied presented a great affinity with ethnic groups belonging to the Mongoloid Dental Complex due to the frequency (expression) and variability (gradation) of the tooth crown traits, upper incisors, the Carabelli trait, the protostylid, cusp 6 and cusp 7. The influence of the Caucasoide Dental Complex associated with ethno-historical processes cannot be ruled out.

Calibration-free portable Young's-modulus tester with isolated langasite oscillator.

PubMed

Ogi, Hirotsugu; Sakamoto, Yuto; Hirao, Masahiko

2014-09-01

A ballpoint-pen-type portable ultrasonic oscillator is developed for quantitative measurement of Young's modulus on a solid. It consists of an electrodeless rod-shaped langasite oscillator with a tungsten-carbide spherical-shaped tip at the end, permanent magnets for making a constant force at the contact interface, and antennas for exciting and detecting the longitudinal vibration contactlessly. The resonance frequency of the oscillator is changed by contact with the specimen, reflecting Young's modulus of the specimen at the contact area. The langasite oscillator is supported at the nodal points so that its acoustical contact occurs only at the specimen, making a calibration-free measurement realistic. Young's moduli of various specimens were evaluated within 15% error just by touching the specimens with the probe. The error becomes smaller than 10% for lower Young-modulus materials (<∼150 GPa). Copyright © 2014 Elsevier B.V. All rights reserved.

Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet.

PubMed

Kimura, Daiju; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

2014-02-01

We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for 2.45 GHz, 11-13 GHz, and multi-frequencies. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. The absorbed powers are estimated for each mode. We show a new guiding principle, which the number of efficient microwave mode should be selected to fit to that of multipole of the comb-shaped magnets. We obtained the excitation of the selective modes using new mobile plate tuner to enhance ECR efficiency.

Method of making bonded or sintered permanent magnets

DOEpatents

McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

1993-08-31

An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

Method of making bonded or sintered permanent magnets

DOEpatents

McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

1995-11-28

An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density. 14 figs.

Method of making bonded or sintered permanent magnets

DOEpatents

McCallum, R. William; Dennis, Kevin W.; Lograsso, Barbara K.; Anderson, Iver E.

1995-11-28

An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

The CHARGE association: report of two cases.

PubMed

Venetikidou, A

1993-01-01

Although many reports of the CHARGE association appear in the literature, the dental findings were never discussed before. In this report of two cases, both patients present with delayed eruption of the permanent teeth and a remarkable similarity of the eruption pattern of the mandibular teeth. One lower permanent central incisor is congenitally missing, while the other is malformed. The lower permanent laterals of JM have erupted lingually and interfere with his speech and function of the tongue. Mandibular retrognathism is present. TM had a V-shaped constricted upper arch, which was expanded in a first phase of orthodontic intervention. Fixed appliances are the future considerations for the correction of the malocclusion.

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.

Investigation of the capture of magnetic particles from high-viscosity fluids using permanent magnets

PubMed Central

Garraud, A.; Velez, C.; Shah, Y.; Garraud, N.; Kozissnik, B.; Yarmola, E. G.; Allen, K. D.; Dobson, J.; Arnold, D. P.

2015-01-01

Goal This paper investigates the practicality of using a small, permanent magnet to capture magnetic particles out of high-viscosity biological fluids, such as synovial fluid. Methods Numerical simulations are used to predict the trajectory of magnetic particles toward the permanent magnet. The simulations are used to determine a “collection volume” with a time-dependent size and shape, which determines the number of particles that can be captured from the fluid in a given amount of time. Results The viscosity of the fluid strongly influences the velocity of the magnetic particles towards the magnet, hence the collection volume after a given time. In regards to the design of the magnet, the overall size is shown to most strongly influence the collection volume in comparison to the magnet shape or aspect ratio. Conclusion Numerical results showed good agreement with in vitro experimental magnetic collection results. Significance In the long-term, this work aims to facilitate optimization of the collection of magnetic particle-biomarker conjugates from high-viscosity biological fluids without the need to remove the fluid from a patient. PMID:26208261

Investigation of the Capture of Magnetic Particles From High-Viscosity Fluids Using Permanent Magnets.

PubMed

Garraud, Alexandra; Velez, Camilo; Shah, Yash; Garraud, Nicolas; Kozissnik, Bettina; Yarmola, Elena G; Allen, Kyle D; Dobson, Jon; Arnold, David P

2016-02-01

This paper investigates the practicality of using a small, permanent magnet to capture magnetic particles out of high-viscosity biological fluids, such as synovial fluid. Numerical simulations are used to predict the trajectory of magnetic particles toward the permanent magnet. The simulations are used to determine a "collection volume" with a time-dependent size and shape, which determines the number of particles that can be captured from the fluid in a given amount of time. The viscosity of the fluid strongly influences the velocity of the magnetic particles toward the magnet, hence, the collection volume after a given time. In regards to the design of the magnet, the overall size is shown to most strongly influence the collection volume in comparison to the magnet shape or aspect ratio. Numerical results showed good agreement with in vitro experimental magnetic collection results. In the long term, this paper aims to facilitate optimization of the collection of magnetic particle-biomarker conjugates from high-viscosity biological fluids without the need to remove the fluid from a patient.

Modeling of vibrations isolation and arrest by shape memory parts and permanent magnets

NASA Astrophysics Data System (ADS)

Belyaev, Fedor S.; Volkov, Aleksandr E.; Evard, Margarita E.; Vikulenkov, Andrey V.; Uspenskiy, Evgeniy S.

2018-05-01

A vibration protection system under consideration consists of a payload connected to a vibrating housing by shape memory alloy (SMA) slotted springs. To provide an arrest function two permanent magnets are inserted into the system. The slotted SMA elements are preliminary deformed in the martensitic state. Activation of one element by heating initiates force and displacement generation, which provide an arrest of the payload by magnets. The magnets also secure the arrest mode after cooling of the SMA element. Activation of the other element results in uncaging of the payload and switching to the vibration isolation mode. Computer simulations of arrest and uncaging when the housing is quiescent or producing sine-wave displacements were carried out. Functional-mechanical behavior of SMA parts was described by means of a microstructural model.

Graphene levitation and orientation control using a magnetic field

NASA Astrophysics Data System (ADS)

Niu, Chao; Lin, Feng; Wang, Zhiming M.; Bao, Jiming; Hu, Jonathan

2018-01-01

This paper studies graphene levitation and orientation control using a magnetic field. The torques in all three spatial directions induced by diamagnetic forces are used to predict stable conditions for different shapes of millimeter-sized graphite plates. We find that graphite plates, in regular polygon shapes with an even number of sides, will be levitated in a stable manner above four interleaved permanent magnets. In addition, the orientation of micrometer-sized graphene flakes near a permanent magnet is studied in both air and liquid environments. Using these analyses, we are able to simulate optical transmission and reflection on a writing board and thereby reveal potential applications using this technology for display screens. Understanding the control of graphene flake orientation will lead to the discovery of future applications using graphene flakes.

Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

NASA Astrophysics Data System (ADS)

Dirba, J.; Lavrinovicha, L.; Dobriyan, R.

2017-04-01

The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

Space law and space resources

NASA Technical Reports Server (NTRS)

Goldman, Nathan C.

1992-01-01

Space industrialization is confronting space law with problems that are changing old and shaping new legal principles. The return to the Moon, the next logical step beyond the space station, will establish a permanent human presence there. Science and engineering, manufacturing and mining will involve the astronauts in the settlement of the solar system. These pioneers, from many nations, will need a legal, political, and social framework to structure their lives and interactions. International and even domestic space law are only the beginning of this framework. Dispute resolution and simple experience will be needed in order to develop, over time, a new social system for the new regime of space.

The quintuple-shape memory effect in electrospun nanofiber membranes

NASA Astrophysics Data System (ADS)

Zhang, Fenghua; Zhang, Zhichun; Liu, Yanju; Lu, Haibao; Leng, Jinsong

2013-08-01

Shape memory fibrous membranes (SMFMs) are an emerging class of active polymers, which are capable of switching from a temporary shape to their permanent shape upon appropriate stimulation. Quintuple-shape memory membranes based on the thermoplastic polymer Nafion, with a stable fibrous structure, are achieved via electrospinning technology, and possess a broad transition temperature. The recovery of multiple temporary shapes of electrospun membranes can be triggered by heat in a single triple-, quadruple-, quintuple-shape memory cycle, respectively. The fiber morphology and nanometer size provide unprecedented design flexibility for the adjustable morphing effect. SMFMs enable complex deformations at need, having a wide potential application field including smart textiles, artificial intelligence robots, bio-medical engineering, aerospace technologies, etc in the future.

Frequency and variability of dental morphology in deciduous and permanent dentition of a Nasa indigenous group in the municipality of Morales, Cauca, Colombia

PubMed Central

Díaz, Eider; García, Lorena; Hernández, Michelle; Palacio, Lesly; Ruiz, Diana; Velandia, Nataly; Villavicencio, Judy

2014-01-01

Objectives: To determine the frequency, variability, sexual dimorphism and bilateral symmetry of fourteen dental crown traits in the deciduous and permanent dentition of 60 dental models (35 women and 25 men) obtained from a native, indigenous group of Nasa school children of the Musse Ukue group in the municipality of Morales, Department of Cauca, Colombia. Methods: This is a quantitative, descriptive, cross-sectional study that characterizes dental morphology by means of the systems for temporary dentition from Dahlberg (winging), and ASUDAS (crowding, reduction of hypocone, metaconule and cusp 6), Hanihara (central and lateral incisors in shovel-shape and cusp 7), Sciulli (double bit, layered fold protostylid, cusp pattern and cusp number) and Grine (Carabelli trait); and in permanent dentition from ASUDAS (Winging, crowding, central and lateral incisors in shovel-shape and double shovel-shape, Carabelli trait, hypocone reduction, metaconule, cusp pattern, cusp number, layered fold protostylid, cusp 6 and cusp 7). Results: The most frequent dental crown features were the shovel-shaped form, grooved and fossa forms of the Carabelli trait, metaconule, cusp pattern Y6, layered fold, protostylid (point P) and cusp 6. Sexual dimorphism was not observed and there was bilateral symmetry in the expression of these features. Conclusions: The sample studied presented a great affinity with ethnic groups belonging to the Mongoloid Dental Complex due to the frequency (expression) and variability (gradation) of the tooth crown traits, upper incisors, the Carabelli trait, the protostylid, cusp 6 and cusp 7. The influence of the Caucasoide Dental Complex associated with ethno-historical processes cannot be ruled out. PMID:24970955

Longitudinal wave function control in single quantum dots with an applied magnetic field

PubMed Central

Cao, Shuo; Tang, Jing; Gao, Yunan; Sun, Yue; Qiu, Kangsheng; Zhao, Yanhui; He, Min; Shi, Jin-An; Gu, Lin; Williams, David A.; Sheng, Weidong; Jin, Kuijuan; Xu, Xiulai

2015-01-01

Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field. For a pure InAs quantum dot with a shape of pyramid or truncated pyramid, the hole wave function always occupies the base because of the less confinement at base, which induces a permanent dipole oriented from base to apex. With applying magnetic field along the base-apex direction, the hole wave function shrinks in the base plane. Because of the linear changing of the confinement for hole wave function from base to apex, the center of effective mass moves up during shrinking process. Due to the uniform confine potential for electrons, the center of effective mass of electrons does not move much, which results in a permanent dipole moment change and an inverted electron-hole alignment along the magnetic field direction. Manipulating the wave function longitudinally not only provides an alternative way to control the charge distribution with magnetic field but also a new method to tune electron-hole interaction in single quantum dots. PMID:25624018

Longitudinal wave function control in single quantum dots with an applied magnetic field.

PubMed

Cao, Shuo; Tang, Jing; Gao, Yunan; Sun, Yue; Qiu, Kangsheng; Zhao, Yanhui; He, Min; Shi, Jin-An; Gu, Lin; Williams, David A; Sheng, Weidong; Jin, Kuijuan; Xu, Xiulai

2015-01-27

Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field. For a pure InAs quantum dot with a shape of pyramid or truncated pyramid, the hole wave function always occupies the base because of the less confinement at base, which induces a permanent dipole oriented from base to apex. With applying magnetic field along the base-apex direction, the hole wave function shrinks in the base plane. Because of the linear changing of the confinement for hole wave function from base to apex, the center of effective mass moves up during shrinking process. Due to the uniform confine potential for electrons, the center of effective mass of electrons does not move much, which results in a permanent dipole moment change and an inverted electron-hole alignment along the magnetic field direction. Manipulating the wave function longitudinally not only provides an alternative way to control the charge distribution with magnetic field but also a new method to tune electron-hole interaction in single quantum dots.

Thermomechanical behavior of shape memory elastomeric composites

NASA Astrophysics Data System (ADS)

Ge, Qi; Luo, Xiaofan; Rodriguez, Erika D.; Zhang, Xiao; Mather, Patrick T.; Dunn, Martin L.; Qi, H. Jerry

2012-01-01

Shape memory polymers (SMPs) can fix a temporary shape and recover their permanent shape in response to environmental stimuli such as heat, electricity, or irradiation. Most thermally activated SMPs use the macromolecular chain mobility change around the glass transition temperature ( Tg) to achieve the shape memory (SM) effects. During this process, the stiffness of the material typically changes by three orders of magnitude. Recently, a composite materials approach was developed to achieve thermally activated shape memory effect where the material exhibits elastomeric response in both the temporary and the recovered configurations. These shape memory elastomeric composites (SMECs) consist of an elastomeric matrix reinforced by a semicrystalline polymer fiber network. The matrix provides background rubber elasticity while the fiber network can transform between solid crystals and melt phases over the operative temperature range. As such it serves as a reversible "switching phase" that enables shape fixing and recovery. Shape memory elastomeric composites provide a new paradigm for the development of a wide array of active polymer composites that utilize the melt-crystal transition to achieve the shape memory effect. This potentially allows for material systems with much simpler chemistries than most shape memory polymers and thus can facilitate more rapid material development and insertion. It is therefore important to understand the thermomechanical behavior and to develop corresponding material models. In this paper, a 3D finite-deformation constitutive modeling framework was developed to describe the thermomechanical behavior of SMEC. The model is phenomenological, although inspired by micromechanical considerations of load transfer between the matrix and fiber phases of a composite system. It treats the matrix as an elastomer and the fibers as a complex solid that itself is an aggregate of melt and crystal phases that evolve from one to the other during a temperature change. As such, the composite consists of an elastomer reinforced by a soft liquid at high temperature and a stiff solid at low temperature. The model includes a kinetic description of the non-isothermal crystallization and melting of the fibers during a temperature change. As the fibers transform from melt to crystal during cooling it is assumed that new crystals are formed in an undeformed state, which requires careful tracking of the kinematics of the evolving phases which comes at a significant computational cost. In order to improve the computational efficiency, an effective phase model (EPM) is adopted to treat the evolving crystal phases as an effective medium. A suite of careful thermomechanical experiments with a SMEC was carried out to calibrate various model parameters, and then to demonstrate the ability of the model to accurately capture the shape memory behavior of the SMEC system during complex thermomechanical loading scenarios. The model also identifies the effects of microstructural design parameters such as the fiber volume fraction.

Radial stiffness improvement of a flywheel system using multi-surface superconducting levitation

NASA Astrophysics Data System (ADS)

Basaran, Sinan; Sivrioglu, Selim

2017-03-01

The goal of this research study is the maximization of the levitation force in a flywheel system by the use of more than one permanent magnet with a single ring-shaped HTS material. An analytical model for the radial stiffness of the ring HTS-PM is derived using the frozen image approach. The experimental works are carried out for different polarizations of the permanent magnets, and radial stiffness values are obtained from the radial force measurements. The rotational test of the flywheel system is also realized for different cases. Finally, natural frequencies of the flywheel superconducting magnetic bearing system are experimentally obtained for different combinations of the permanent magnets using a frequency analyzer.

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

Bachman, Daniel; Chen, Zhijiang; Wang, Christopher

Phase errors caused by fabrication variations in silicon photonic integrated circuits are an important problem, which negatively impacts device yield and performance. This study reports our recent progress in the development of a method for permanent, postfabrication phase error correction of silicon photonic circuits based on femtosecond laser irradiation. Using beam shaping technique, we achieve a 14-fold enhancement in the phase tuning resolution of the method with a Gaussian-shaped beam compared to a top-hat beam. The large improvement in the tuning resolution makes the femtosecond laser method potentially useful for very fine phase trimming of silicon photonic circuits. Finally, wemore » also show that femtosecond laser pulses can directly modify silicon photonic devices through a SiO 2 cladding layer, making it the only permanent post-fabrication method that can tune silicon photonic circuits protected by an oxide cladding.« less

Low density biodegradable shape memory polyurethane foams for embolic biomedical applications

PubMed Central

Singhal, Pooja; Small, Ward; Cosgriff-Hernandez, Elizabeth; Maitland, Duncan J; Wilson, Thomas S

2014-01-01

Low density shape memory polymer foams hold significant interest in the biomaterials community for their potential use in minimally invasive embolic biomedical applications. The unique shape memory behavior of these foams allows them to be compressed to a miniaturized form, which can be delivered to an anatomical site via a transcatheter process, and thereafter actuated to embolize the desired area. Previous work in this field has described the use of a highly covalently crosslinked polymer structure for maintaining excellent mechanical and shape memory properties at the application-specific ultra low densities. This work is aimed at further expanding the utility of these biomaterials, as implantable low density shape memory polymer foams, by introducing controlled biodegradability. A highly covalently crosslinked network structure was maintained by use of low molecular weight, symmetrical and polyfunctional hydroxyl monomers such as Polycaprolactone triol (PCL-t, Mn 900 g), N,N,N0,N0-Tetrakis (hydroxypropyl) ethylenediamine (HPED), and Tris (2-hydroxyethyl) amine (TEA). Control over the degradation rate of the materials was achieved by changing the concentration of the degradable PCL-t monomer, and by varying the material hydrophobicity. These porous SMP materials exhibit a uniform cell morphology and excellent shape recovery, along with controllable actuation temperature and degradation rate. We believe that they form a new class of low density biodegradable SMP scaffolds that can potentially be used as “smart” non-permanent implants in multiple minimally invasive biomedical applications. PMID:24090987

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

DOE PAGES

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

2018-02-27

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

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

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

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

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

Reconfigurable photonic crystals enabled by pressure-responsive shape-memory polymers

PubMed Central

Fang, Yin; Ni, Yongliang; Leo, Sin-Yen; Taylor, Curtis; Basile, Vito; Jiang, Peng

2015-01-01

Smart shape-memory polymers can memorize and recover their permanent shape in response to an external stimulus (for example, heat). They have been extensively exploited for a wide spectrum of applications ranging from biomedical devices to aerospace morphing structures. However, most of the existing shape-memory polymers are thermoresponsive and their performance is hindered by heat-demanding programming and recovery steps. Although pressure is an easily adjustable process variable such as temperature, pressure-responsive shape-memory polymers are largely unexplored. Here we report a series of shape-memory polymers that enable unusual ‘cold' programming and instantaneous shape recovery triggered by applying a contact pressure at ambient conditions. Moreover, the interdisciplinary integration of scientific principles drawn from two disparate fields—the fast-growing photonic crystal and shape-memory polymer technologies—enables fabrication of reconfigurable photonic crystals and simultaneously provides a simple and sensitive optical technique for investigating the intriguing shape-memory effects at nanoscale. PMID:26074349

Vibration converter with magnetic levitation

NASA Astrophysics Data System (ADS)

Gladilin, A. V.; Pirogov, V. A.; Golyamina, I. P.; Kulaev, U. V.; Kurbatov, P. A.; Kurbatova, E. P.

2015-05-01

The paper presents a mathematical model, the results of computational and theoretical research, and the feasibility of creating a vibration converter with full magnetic levitation in the suspension of a high-temperature superconductor (HTSC). The axial and radial stability of the active part of the converter is provided by the interaction of the magnetic field of ring-shaped permanent magnets and a hollow cylinder made of the ceramic HTSC material. The force is created by a system of current-carrying coils whose magnetic field is polarized by permanent magnets and interacts with induced currents in the superconducting cylinder. The case of transition to the superconducting state of HTSC material in the field of the permanent magnets (FC mode) is considered. The data confirm the outlook for the proposed technical solutions.

Manipulation of permanent magnetic polymer micro-robots: a new approach towards guided wireless capsule endoscopy

NASA Astrophysics Data System (ADS)

Hilbich, D.; Rahbar, A.; Khosla, A.; Gray, B. L.

2012-10-01

We present the initial experimental results for manipulating micro-robots featuring permanent magnetic polymer magnets for guided wireless endoscopy applications. The magnetic polymers are fabricated by doping polydimethylsiloxane (PDMS) with permanent isotropic rare earth magnetic powder (MQFP 12-5) with an average particle size of 6 μm. The prepared magnetic nanocomposite polymer (M-NCP) is patterned in the desired shape against a plexiglass mold via soft lithography techniques. It is observed that the fabricated micro-robot magnets have a magnetic field strength of 50 mT and can easily be actuated by applying a field of 8.3 mT (field measured at the capsule's position) and moved at a rate of 5 inches/second.

40 CFR 280.71 - Permanent closure and changes-in-service.

Code of Federal Regulations, 2011 CFR

2011-07-01

... UNDERGROUND STORAGE TANKS (UST) Out-of-Service UST Systems and Closure § 280.71 Permanent closure and changes... sludges. All tanks taken out of service permanently must also be either removed from the ground or filled with an inert solid material. (c) Continued use of an UST system to store a non-regulated substance is...

40 CFR 280.71 - Permanent closure and changes-in-service.

Code of Federal Regulations, 2013 CFR

2013-07-01

... UNDERGROUND STORAGE TANKS (UST) Out-of-Service UST Systems and Closure § 280.71 Permanent closure and changes... sludges. All tanks taken out of service permanently must also be either removed from the ground or filled with an inert solid material. (c) Continued use of an UST system to store a non-regulated substance is...

40 CFR 280.71 - Permanent closure and changes-in-service.

Code of Federal Regulations, 2012 CFR

2012-07-01

... UNDERGROUND STORAGE TANKS (UST) Out-of-Service UST Systems and Closure § 280.71 Permanent closure and changes... sludges. All tanks taken out of service permanently must also be either removed from the ground or filled with an inert solid material. (c) Continued use of an UST system to store a non-regulated substance is...

40 CFR 280.71 - Permanent closure and changes-in-service.

Code of Federal Regulations, 2014 CFR

2014-07-01

... UNDERGROUND STORAGE TANKS (UST) Out-of-Service UST Systems and Closure § 280.71 Permanent closure and changes... sludges. All tanks taken out of service permanently must also be either removed from the ground or filled with an inert solid material. (c) Continued use of an UST system to store a non-regulated substance is...

Constraints on the perturbed mutual motion in Didymos due to impact-induced deformation of its primary after the DART impact

NASA Astrophysics Data System (ADS)

Hirabayashi, Masatoshi; Schwartz, Stephen R.; Yu, Yang; Davis, Alex B.; Chesley, Steven R.; Fahnestock, Eugene G.; Michel, Patrick; Richardson, Derek C.; Naidu, Shantanu P.; Scheeres, Daniel J.; Cheng, Andrew F.; Rivkin, Andrew S.; Benner, Lance A. M.

2017-12-01

Binary near-Earth asteroid (65803) Didymos is the target of the proposed NASA Double Asteroid Redirection Test (DART), part of the Asteroid Impact & Deflection Assessment (AIDA) mission concept. In this mission, the DART spacecraft is planned to impact the secondary body of Didymos, perturbing mutual dynamics of the system. The primary body is currently rotating at a spin period close to the spin barrier of asteroids, and materials ejected from the secondary due to the DART impact are likely to reach the primary. These conditions may cause the primary to reshape, due to landslides or internal deformation, changing the permanent gravity field. Here, we propose that if shape deformation of the primary occurs, the mutual orbit of the system would be perturbed due to a change in the gravity field. We use a numerical simulation technique based on the full two-body problem to investigate the shape effect on the mutual dynamics in Didymos after the DART impact. The results show that under constant volume, shape deformation induces strong perturbation in the mutual motion. We find that the deformation process always causes the orbital period of the system to become shorter. If surface layers with a thickness greater than ∼0.4 m on the poles of the primary move down to the equatorial region due to the DART impact, a change in the orbital period of the system and in the spin period of the primary will be detected by ground-based measurement.

Postfabrication Phase Error Correction of Silicon Photonic Circuits by Single Femtosecond Laser Pulses

DOE PAGES

Bachman, Daniel; Chen, Zhijiang; Wang, Christopher; ...

2016-11-29

Phase errors caused by fabrication variations in silicon photonic integrated circuits are an important problem, which negatively impacts device yield and performance. This study reports our recent progress in the development of a method for permanent, postfabrication phase error correction of silicon photonic circuits based on femtosecond laser irradiation. Using beam shaping technique, we achieve a 14-fold enhancement in the phase tuning resolution of the method with a Gaussian-shaped beam compared to a top-hat beam. The large improvement in the tuning resolution makes the femtosecond laser method potentially useful for very fine phase trimming of silicon photonic circuits. Finally, wemore » also show that femtosecond laser pulses can directly modify silicon photonic devices through a SiO 2 cladding layer, making it the only permanent post-fabrication method that can tune silicon photonic circuits protected by an oxide cladding.« less

Optimization of a superconducting linear levitation system using a soft ferromagnet

NASA Astrophysics Data System (ADS)

Agramunt-Puig, Sebastia; Del-Valle, Nuria; Navau, Carles; Sanchez, Alvaro

2013-04-01

The use of guideways that combine permanent magnets and soft ferromagnetic materials is a common practice in magnetic levitation transport systems (maglevs) with bulk high-temperature superconductors. Theoretical tools to simulate in a realistic way both the behavior of all elements (permanent magnets, soft ferromagnet and superconductor) and their mutual effects are helpful to optimize the designs of real systems. Here we present a systematic study of the levitation of a maglev with translational symmetry consisting of a superconducting bar and a guideway with two identic permanent magnets and a soft ferromagnetic material between them. The system is simulated with a numerical model based on the energy minimization method that allows to analyze the mutual interaction of the superconductor, assumed to be in the critical state, and a soft ferromagnet with infinite susceptibility. Results indicate that introducing a soft ferromagnet within the permanent magnets not only increases the levitation force but also improves the stability. Besides, an estimation of the relative sizes and shapes of the soft ferromagnet, permanent magnets and the superconductor in order to obtain large levitation force with full stability is provided.

Combinatorial investigation of rare-earth free permanent magnets

NASA Astrophysics Data System (ADS)

Fackler, Sean Wu

The combinatorial high throughput method allows one to rapidly study a large number of samples with systematically changing parameters. We apply this method to study Fe-Co-V alloys as alternatives to rare-earth permanent magnets. Rare-earth permanent magnets derive their unmatched magnetic properties from the hybridization of Fe and Co with the f-orbitals of rare-earth elements, which have strong spin-orbit coupling. It is predicted that Fe and Co may also have strong hybridization with 4d and 5d refractory transition metals with strong spin-orbit coupling. Refractory transition metals like V also have the desirable property of high temperature stability, which is important for permanent magnet applications in traction motors. In this work, we focus on the role of crystal structure, composition, and secondary phases in the origin of competitive permanent magnetic properties of a particular Fe-Co-V alloy. Fe38Co52V10, compositions are known as Vicalloys. Fe-CoV composition spreads were sputtered onto three-inch silicon wafers and patterned into discrete sample pads forming a combinatorial library. We employed highthroughput screening methods using synchrotron X-rays, wavelength dispersive spectroscopy, and magneto-optical Kerr effect (MOKE) to rapidly screen crystal structure, composition, and magnetic properties, respectively. We found that in-plane magnetic coercive fields of our Vicalloy thin films agree with known bulk values (300 G), but found a remarkable eight times increase of the out-of-plane coercive fields (˜2,500 G). To explain this, we measured the switching fields between in-plane and out-of-plane thin film directions which revealed that the Kondorsky model of 180° domain wall reversal was responsible for Vicalloy's enhanced out-of-plane coercive field and possibly its permanent magnetic properties. The Kondorsky model suggests that domain-wall pinning is the origin of Vicalloy's permanent magnetic properties, in contrast to strain, shape, or crystalline anisotropy mechanisms suggested in the literature. We also studied the thickness dependence of an Fe70Co30- V thin film library to consider the unique effects of our thin film libraries which are not found in bulk samples. We present results of data mining of synchrotron X-ray diffraction data using non-negative matrix factorization (NMF). NMF can automatically identify pure crystal phases that make up an unknown phase mixture. We found a strong correlation between magnetic properties and crystal phase quantity using this valuable visualization. In addition to the combinatorial study, this dissertation includes a study of strain controlled properties of magnetic thin films for future applications in random access memories. We investigated the local coupling between dense magnetic stripe domains in transcritical Permalloy (tPy) thin films and ferroelectric domains of BaTiO3 single crystals in a tPy/BaTiO3 heterostructure. Two distinct changes in the magnetic stripe domains of tPy were observed from the magnetic force microscopy images after cooling the heterostructure from above the ferroelectric Curie temperature of BaTiO3 (120°C) to room temperature. First, an abrupt break in the magnetic stripe domain direction was found at the ferroelectric a-c-domain boundaries due to an induced change in in-plane magnetic anisotropy. Second, the magnetic stripe domain period increased when coupled to a ferroelectric a-domain due to a change in out-of-plane magnetic anisotropy. Micromagnetic simulations reveal that local magnetic anisotropy energy from inverse magnetostriction is conserved between in-plane and out-of-plane components.

Maintaining a permanent plot data base for growth and yield research: Solutions to some recurring problems

Treesearch

John C. Byrne

1993-01-01

Methods for solving some recurring problems of maintaining a permanent plot data base for growth and yield reseuch are described. These methods include documenting data from diverse sampling designs, changing sampling designs, changing field procedures, and coordinating activities in the plots with the land management agency. Managing a permanent plot data base (...

Design of a 4D Printing System Using Thermal Sensitive Smart Materials and Photoactivated Shape Changing Polymers

NASA Astrophysics Data System (ADS)

Leist, Steven Kyle

4D printing is an emerging additive manufacturing technology that combines 3D printing with smart materials. Current 3D printing technology can print objects with a multitude of materials; however, these objects are usually static, geometrically permanent, and not suitable for multi-functional use. The 4D printed objects can change their shape over time when exposed to different external stimuli such as heat, pressure, magnetic fields, or moisture. In this research, heat and light reactive smart materials are explored as a 4D printing materials. Synthetization of a material that actuates when exposed to stimulus can be a very difficult process, and merging that same material with the ability to be 3D printed can be further difficult. A common 3D printing thermoplastic, poly(lactic) acid (PLA), is used as a shape memory material that is 3D printed using a fused deposition machine (FDM) and combined with nylon fabric for the exploration of smart textiles. The research shows that post printed PLA possesses shape memory properties depending on the thickness of the 3D printed material and the activation temperature. PLA can be thermomechanically trained into temporary shapes and return to its original shape when exposed to high temperatures. PLA can be 3D printed onto nylon fabrics for the creation of the smart textiles. Additionally, a photoisomerable shape changing material is explored because light activation is wireless, controllable, focusable, abundant, causes rapid shape change of the smart material, and induces reversible shape change in the material. This study supports the fundamental research to generate knowledge needed for synthesis of a novel azobenzene shape changing polymer (SCP) and integrating this smart material into objects printed with a 4D printing process using syringe printing. Multiple versions of azobenzene SCP are synthesized that actuate when exposed to 365 nm and 455 nm light. Two SCPs, MeOABHx and DR1Hx, are selected for the 4D printing research because of their ability to photoisomerize at room temperature and 3D printability. The physical properties of these polymers are characterized, photomechanical bending tests are performed, and the photo-generated stress is measured using a dynamic mechanical analyzer (DMA). The SCPs are deposited onto a passive layer to create bilayer films in order to actuate. The photomechanical efficiency of bilayer films is evaluated depending on the thickness of the passive layer film, type of azobenzene SCP, wavelength of the light source, intensity of the light source, and distance between the light and films. 4D printing can be used to streamline the design and manufacturing process of actuating parts. Complex heavy parts can be removed from actuation systems such as onboard power storage, motors, sensors, and processors by embedding these capabilities into the material themselves. This reduces the amount of required parts, the amount of materials, and reduces the cost of producing these parts. 4D printed products possess the properties of programmability, reaction and adaption to their environment, and automation. Therefore, they can find wider applications including foldable unmanned aerial vehicles, artificial muscles, grippers, biomedical drug delivery systems, stents, and minimally invasive surgeries.

Modeling of non-ideal hard permanent magnets with an affine-linear model, illustrated for a bar and a horseshoe magnet

NASA Astrophysics Data System (ADS)

Glane, Sebastian; Reich, Felix A.; Müller, Wolfgang H.

2017-11-01

This study is dedicated to continuum-scale material modeling of isotropic permanent magnets. An affine-linear extension to the commonly used ideal hard model for permanent magnets is proposed, motivated, and detailed. In order to demonstrate the differences between these models, bar and horseshoe magnets are considered. The structure of the boundary value problem for the magnetic field and related solution techniques are discussed. For the ideal model, closed-form analytical solutions were obtained for both geometries. Magnetic fields of the boundary value problems for both models and differently shaped magnets were computed numerically by using the boundary element method. The results show that the character of the magnetic field is strongly influenced by the model that is used. Furthermore, it can be observed that the shape of an affine-linear magnet influences the near-field significantly. Qualitative comparisons with experiments suggest that both the ideal and the affine-linear models are relevant in practice, depending on the magnetic material employed. Mathematically speaking, the ideal magnetic model is a special case of the affine-linear one. Therefore, in applications where knowledge of the near-field is important, the affine-linear model can yield more accurate results—depending on the magnetic material.

Dynamics of Permanent-Magnet Biased Active Magnetic Bearings

NASA Technical Reports Server (NTRS)

Fukata, Satoru; Yutani, Kazuyuki

1996-01-01

Active magnetic radial bearings are constructed with a combination of permanent magnets to provide bias forces and electromagnets to generate control forces for the reduction of cost and the operating energy consumption. Ring-shaped permanent magnets with axial magnetization are attached to a shaft and share their magnet stators with the electromagnets. The magnet cores are made of solid iron for simplicity. A simplified magnetic circuit of the combined magnet system is analyzed with linear circuit theory by approximating the characteristics of permanent magnets with a linear relation. A linearized dynamical model of the control force is presented with the first-order approximation of the effects of eddy currents. Frequency responses of the rotor motion to disturbance inputs and the motion for impulsive forces are tested in the non-rotating state. The frequency responses are compared with numerical results. The decay of rotor speed due to magnetic braking is examined. The experimental results and the presented linearized model are similar to those of the all-electromagnetic design.

Clinical Evaluation of Microhybrid Composite and Glass lonomer Restorative Material in Permanent Teeth.

PubMed

Kharma, Khalil; Zogheib, Tatiana; Bhandi, Shilpa; Mehanna, Carina

2018-02-01

The aim of this study was to clinically compare glass ionomer cement (GIC) with microhybrid composite resin used in class I cavities on permanent teeth over a period of 9 months. A total of 40 teeth with class I cavities were divided into two groups (n = 20) and restored with GIC (EQUIA; GC) and microhybrid resin composite (Amelogen Plus; Ultradent). Restorations were evaluated at ×4.5 magnification using the United States Public Health Service (USPHS) criteria every 3 months. Statistical analysis was performed using the Fisher's exact test (a < 0.05). The data obtained reported no statistical significance difference between both groups in regard to anatomical shape, color, postoperative sensitivity, secondary caries, material handling, adaptation, and marginal staining. The results of this clinical study showed that GIC (EQUIA; GC) can be used for the restoration of permanent teeth and may be more appropriate for certain clinical situations than the resin composite material. EQUIA (GIC) is a viable alternative to resin composite in restoring class I cavities in permanent teeth.

Ternary Polymeric Composites Exhibiting Bulk and Surface Quadruple-Shape Memory Properties.

PubMed

Buffington, Shelby Lois; Posnick, Benjamin M; Paul, Justine Elizabeth; Mather, Patrick T

2018-06-19

We report the design and characterization of a multiphase quadruple shape memory composite capable of switching between 4 programmed shapes, three temporary and one permanent. Our approach combined two previously reported fabrication methods by embedding an electrospun mat of PCL in a miscible blend of epoxy monomers and PMMA as a composite matrix. As epoxy polymerization occurred the matrix underwent phase separation between the epoxy and PMMA materials. This created a multiphase composite with PCL fibers and a two-phase matrix composed of phase-separated epoxy and PMMA. The resulting composite demonstrated three separate thermal transitions and amenability to mechanical programming of three separate temporary shapes in addition to one final, equilibrium shape. In addition, quadruple surface shape memory abilities are successfully demonstrated. The versatility of this approach offers a large degree of design flexibility for multi-shape memory materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanostructure devices and fabrication method

NASA Technical Reports Server (NTRS)

Stevens, Ramsey M. (Inventor)

2009-01-01

An ion flux is directed to a carbon nanotube to permanently shape, straighten and/or bend the carbon nanotube into a desired configuration. Such carbon nanotubes have many properties that make them ideal as probes for Scanning Probe Microscopy and many other applications.

Early environmental predictors of the affective and interpersonal constructs of psychopathy.

PubMed

Daversa, Maria T

2010-02-01

Early childhood maltreatment (i.e., physical, sexual, emotional abuse) and caregiver disruptions are hypothesized to be instrumental in altering the neurobiology of the brain, particularly the amygdala, and contributing to the development of the affective deficits examined in individuals with psychopathy. Exposure to early untoward life events in models of rodent and nonhuman primates changes the neurobiology of the stress response. It is hypothesized that these changes may permanently shape brain regions that mediate stress and emotion and therefore play a role in the etiology of affective disorders in humans. The significance of experience (e.g., the intensity/severity, chronicity/duration, and developmental timing of experiences) and how the accompanying changes in the activity of the hypothalamic-pituitary-adrenocortical system affect alterations in the amygdala are discussed as critical contributors to the etiology of psychopathy. A model is proposed in which early maltreatment experiences contribute to alterations to the amygdala and produce a blunted or dissociative response to stress, a key factor in the affective deficits observed in psychopaths.

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.

Next generation shape memory prosthesis (NiTiBOND) for stapedotomy: Short-term results.

PubMed

Green, J Douglas; McElveen, John T

2017-04-01

To review hearing results and complications for the NiTiBOND next generation shape memory prosthesis and compare them with results for the current shape memory prosthesis (SMart). Retrospective, multicenter chart review. Primary laser stapedotomy was performed using either a NiTiBOND or a SMart prosthesis. Ninety-two ears in 79 patients were included in the study (67.4% female), 52 with the NiTiBOND prosthesis and 40 with the SMart prosthesis. Data collected included demographic variables, pre- and postoperative pure-tone air and bone conduction thresholds, speech discrimination scores, complications, and the need for revision surgery. Pure-tone average (PTA) and PTA air-bone gap (ABG) pre- and postoperative were computed. Success was defined as a postoperative ABG of ≤10 dB. There were no significant differences between groups in hearing results, including improvement in ABG, change in speech discrimination, change in air or bone PTA, or change in high-frequency bone PTA. Short-term (mean = 4.4 and 4.9 weeks, respectively) success rates for the NiTiBOND and SMart prostheses were 84.6% and 70.0%, respectively, with this difference closing at the most recent test (83.7% and 80.0%, respectively). No revision surgery took place in either group, and there were no differences in complications such as dizziness, tinnitus, or taste disturbance, though the NiTiBOND group tended to have a lower rate of transient or permanent vertigo. Compared with the SMart prosthesis, the NiTiBOND prosthesis is a safe prosthesis that achieves at least comparable hearing results and may offer some surgical advantages. 4 Laryngoscope, 127:915-920, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Novel mechanisms for solid-state processing and grain growth with microstructure alignment in alnico-8 based permanent magnets

DOE PAGES

Kassen, Aaron G.; White, Emma M. H.; Hu, Liangfa; ...

2017-12-14

An estimated 750,000 new hybrid electric and plug-in battery vehicles, most with permanent magnet synchronous alternating current (PMAC) drive motors, took to the road in 2016 alone. Accompanied by 40% year over year growth in the EV market significant challenges exist in producing large quantities of permanent magnets (on the order of tens of millions) for reliable, low-cost traction motors [IE Agency, Energy Technology Perspectives (2017)]. Since the rare earth permanent magnet (REPM) market is essentially 100% net import reliant in the United States and has proven to have an unstable cost and supply structure in recent years, a replacementmore » RE-free PM material must be designed or selected, fully developed, and implemented. Alnico, with its high saturation magnetization and excellent thermal stability, appears to be uniquely suited for this task. Further, while alnico typically has been considered a relatively low coercivity hard magnet, strides have been made to increase the coercivity to levels suitable for traction drive motors [W Tang, IEEE Trans. Magn., 51 (2015)]. If a simple non-cast approach for achieving near [001] easy axis grain aligned permanent magnets can be found, this would allow massproduced final-shape anisotropic high energy product magnets suitable for usage in compact high RPM rotor designs. Therefore, a powder metallurgical approach is being explored that uses classic compression molding with “de-bind and sinter” methods, where a novel applied uniaxial loading, and an applied magnetic field may create final-shape magnets with highly textured resulting microstructures by two different mechanisms. Results indicate a positive correlation between applied uniaxial load and resulting texture (Fig. 1), along with benefits from using an applied magnetic field for improved texture, as well. Lastly, the apparent mechanisms and resulting properties will be described using closed loop hysteresisgraph measurements, EBSD orientation mapping, and high-resolution SEM.« less

Novel mechanisms for solid-state processing and grain growth with microstructure alignment in alnico-8 based permanent magnets

NASA Astrophysics Data System (ADS)

Kassen, Aaron G.; White, Emma M. H.; Hu, Liangfa; Tang, Wei; Zhou, Lin; Kramer, Matthew J.; Anderson, Iver E.

2018-05-01

An estimated 750,000 new hybrid electric and plug-in battery vehicles, most with permanent magnet synchronous alternating current (PMAC) drive motors, took to the road in 2016 alone. Accompanied by 40% year over year growth in the EV market significant challenges exist in producing large quantities of permanent magnets (on the order of tens of millions) for reliable, low-cost traction motors [IE Agency, Energy Technology Perspectives (2017)]. Since the rare earth permanent magnet (REPM) market is essentially 100% net import reliant in the United States and has proven to have an unstable cost and supply structure in recent years, a replacement RE-free PM material must be designed or selected, fully developed, and implemented. Alnico, with its high saturation magnetization and excellent thermal stability, appears to be uniquely suited for this task. Further, while alnico typically has been considered a relatively low coercivity hard magnet, strides have been made to increase the coercivity to levels suitable for traction drive motors [W Tang, IEEE Trans. Magn., 51 (2015)]. If a simple non-cast approach for achieving near [001] easy axis grain aligned permanent magnets can be found, this would allow mass-produced final-shape anisotropic high energy product magnets suitable for usage in compact high RPM rotor designs. Therefore, a powder metallurgical approach is being explored that uses classic compression molding with "de-bind and sinter" methods, where a novel applied uniaxial loading, and an applied magnetic field may create final-shape magnets with highly textured resulting microstructures by two different mechanisms. Results indicate a positive correlation between applied uniaxial load and resulting texture (Fig. 1), along with benefits from using an applied magnetic field for improved texture, as well. The apparent mechanisms and resulting properties will be described using closed loop hysteresisgraph measurements, EBSD orientation mapping, and high-resolution SEM.

Novel mechanisms for solid-state processing and grain growth with microstructure alignment in alnico-8 based permanent magnets

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

Kassen, Aaron G.; White, Emma M. H.; Hu, Liangfa

An estimated 750,000 new hybrid electric and plug-in battery vehicles, most with permanent magnet synchronous alternating current (PMAC) drive motors, took to the road in 2016 alone. Accompanied by 40% year over year growth in the EV market significant challenges exist in producing large quantities of permanent magnets (on the order of tens of millions) for reliable, low-cost traction motors [IE Agency, Energy Technology Perspectives (2017)]. Since the rare earth permanent magnet (REPM) market is essentially 100% net import reliant in the United States and has proven to have an unstable cost and supply structure in recent years, a replacementmore » RE-free PM material must be designed or selected, fully developed, and implemented. Alnico, with its high saturation magnetization and excellent thermal stability, appears to be uniquely suited for this task. Further, while alnico typically has been considered a relatively low coercivity hard magnet, strides have been made to increase the coercivity to levels suitable for traction drive motors [W Tang, IEEE Trans. Magn., 51 (2015)]. If a simple non-cast approach for achieving near [001] easy axis grain aligned permanent magnets can be found, this would allow massproduced final-shape anisotropic high energy product magnets suitable for usage in compact high RPM rotor designs. Therefore, a powder metallurgical approach is being explored that uses classic compression molding with “de-bind and sinter” methods, where a novel applied uniaxial loading, and an applied magnetic field may create final-shape magnets with highly textured resulting microstructures by two different mechanisms. Results indicate a positive correlation between applied uniaxial load and resulting texture (Fig. 1), along with benefits from using an applied magnetic field for improved texture, as well. Lastly, the apparent mechanisms and resulting properties will be described using closed loop hysteresisgraph measurements, EBSD orientation mapping, and high-resolution SEM.« less

Hydrological states and the resilience of deltaic forested wetlands

NASA Astrophysics Data System (ADS)

Keim, R.; Allen, S. T.

2017-12-01

The flooding regime constitutes a set of chronic disturbances that are largely responsible for ecosystem structure. However, disturbances do not always constitute stresses to plants that survive because of adaptations to flooded conditions. We examine baldcypress-water tupelo forested wetlands in the delta of the Mississippi River as a case study in mechanisms by which hydrologic change shapes wetland ecosystem change, supported by experimental evidence from remote sensing, tree-ring and other field studies, and meta-analysis across the literature. Decreased hydrologic variability caused by water control structures has reduced the frequency of flood events that increase growth of baldcypress and favor its establishment by reducing competition from other species. Hydrologic modifications that lead to semi-permanent, stagnant flooding constitute semi-permanent disturbance that prevents regeneration of any trees, reduces growth of established trees, and reduces stand density by causing mortality of some trees. However, baldcypress trees in low-density stands appear to be generally adapted for long-term survival in stagnant conditions. Thus, initial decreases in stand density after impoundment do not necessarily portend continued conversion away from forest because reduced inter-tree competition is a negative feedback on mortality. Overall, a natural hydrologic regime with high variability in riverine flooding favors denser stands with greater diversity of tree species, and the present, controlled hydrologic regime that has largely eliminated riverine flooding favors open stands. Sea-level rise will increase salinity that quickly leads to forest conversion to marsh, but will also increase stagnant, freshwater flooding further inland. These drivers of hydrologic change reduce carbon assimilation by forests, both by reduced stand-level productivity and decreased forested area.

Tunable system for production of mirror and cusp configurations using chassis of permanent magnets

NASA Astrophysics Data System (ADS)

Hyde, Alexander; Bushmelov, Maxim; Batishchev, Oleg

2018-03-01

Compact arrays of permanent magnets have shown promise as replacements for electromagnets in applications requiring magnetic cusps and mirrors. An adjustable system capable of suspending and translating a pair of light, nonmagnetic chassis carrying such sources of magnetic field has been designed and constructed. Using this device to align two cylindrical chassis, strong solenoid-like domains of field, as well as classic biconic cusp and magnetic mirror topologies, are generated. Employing a pair of ring-shaped chassis instead, the superposition of their naturally-emitted cusps is demonstrated to produce sextupolar and octupolar magnetic fields.

Proportion of various types of thyroid disorders among newborns with congenital hypothyroidism and normally located gland: a regional cohort study.

PubMed

Gaudino, Rossella; Garel, Catherine; Czernichow, Paul; Léger, Juliane

2005-04-01

To determine the proportion of the various types of thyroid disorders among newborns detected by the neonatal TSH screening programme, with a normally located thyroid gland. Patients and methods Of the 882 575 infants screened in our centre between 1981 and 2002, 85 infants with a normally located gland had persistent elevation of serum TSH values (an incidence of 1/10 383). Six of these 85 patients were lost to follow-up and were therefore excluded from the study. During follow-up, patients were classified as having permanent or transient hypothyroidism. Among the 79 patients included in the study, transient (n = 30, 38% of cases) and permanent (n = 49, 62% of cases) congenital hypothyroidism (CH) was demonstrated during the follow-up at the age of 0.7 +/- 0.6 years and 2.6 +/- 1.8 years (P < 0.0001), respectively. The proportion of premature births was significantly higher in the group with transient CH (57%) than in the group with permanent CH (2%) (P < 0.0001). A history of iatrogenic iodine overload was identified during the neonatal period in 69% of transient cases. Among permanent CH cases (n = 49), patients were classified as having a goitre (n = 27, 55% of cases), a normal sized and shaped thyroid gland (n = 14, 29% of cases) or a hypoplastic gland (n = 8, 16% of cases). The latter patients demonstrated global thyroid hypoplasia (n = 3), a right hemithyroid (n = 2), hypoplasia of the left lobe (n = 2), or asymmetry in the location of the two lobes (n = 1). Patients with a normal sized and shaped thyroid gland showed a significantly less severe form of hypothyroidism than those with a goitre or a hypoplastic thyroid gland (P < 0.0002). Among permanent CH cases, those with a goitre (n = 27) had an iodine organification defect (n = 10), Pendred syndrome (n = 1), a defect of thyroglobulin synthesis (n = 8), or a defect of sodium iodine symporter (n = 1), and in seven patients no aetiology could be determined. Among permanent cases with a normal sized and shaped thyroid gland (n = 14), a specific aetiology was found in only one patient (pseudohypoparathyroidism) and two patients had Down's syndrome. Among those with a globally hypoplastic gland, a TSH receptor gene mutation was found in two patients. A precise description of the phenotype can enhance our understanding of various forms of neonatal hypothyroidism as well as their prevalence and management. It also helps to identify cases of congenital hypothyroidism of unknown aetiology, which will need to be investigated in collaboration with molecular biologists.

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

Kassen, Aaron G.; White, Emma M. H.; Tang, Wei

We present economic uncertainty in the rare earth (RE) permanent magnet marketplace, as well as in an expanding electric drive vehicle market that favors permanent magnet alternating current synchronous drive motors, motivated renewed research in RE-free permanent magnets like “alnico,” an Al-Ni-Co-Fe alloy. Thus, high-pressure, gas-atomized isotropic type-8H pre-alloyed alnico powder was compression molded with a clean burn-out binder to near-final shape and sintered to density >99% of cast alnico 8 (full density of 7.3 g/cm 3). To produce aligned sintered alnico magnets for improved energy product and magnetic remanence, uniaxial stress was attempted to promote controlled grain growth, avoidingmore » directional solidification that provides alignment in alnico 9. Lastly, successful development of solid-state powder processing may enable anisotropically aligned alnico magnets with enhanced energy density to be mass-produced.« less

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.

Thermomechanical behavior of a two-way shape memory composite actuator

NASA Astrophysics Data System (ADS)

Ge, Qi; Westbrook, Kristofer K.; Mather, Patrick T.; Dunn, Martin L.; Qi, H. Jerry

2013-05-01

Shape memory polymers (SMPs) are a class of smart materials that can fix a temporary shape and recover to their permanent (original) shape in response to an environmental stimulus such as heat, electricity, or irradiation, among others. Most SMPs developed in the past can only demonstrate the so-called one-way shape memory effect; i.e., one programming step can only yield one shape memory cycle. Recently, one of the authors (Mather) developed a SMP that exhibits both one-way shape memory (1W-SM) and two-way shape memory (2W-SM) effects (with the assistance of an external load). This SMP was further used to develop a free-standing composite actuator with a nonlinear reversible actuation under thermal cycling. In this paper, a theoretical model for the PCO SMP based composite actuator was developed to investigate its thermomechanical behavior and the mechanisms for the observed phenomena during the actuation cycles, and to provide insight into how to improve the design.

Shape Memory Properties and Enzymatic Degradability of Poly(ε-caprolactone)-Based Polyurethane Urea Containing Phenylalanine-Derived Chain Extender.

PubMed

Wang, Rong; Zhang, Fanjun; Lin, Weiwei; Liu, Wenkai; Li, Jiehua; Luo, Feng; Wang, Yaning; Tan, Hong

2018-06-01

Biodegradable shape memory polymers are promising biomaterials for minimally invasive surgical procedures. Herein, a series of linear biodegradable shape memory poly(ε-caprolactone) (PCL)-based polyurethane ureas (PUUs) containing a novel phenylalanine-derived chain extender is synthesized. The phenylalanine-derived chain extender, phenylalanine-hexamethylenediamine-phenylalanine (PHP), contains two chymotrypsin cleaving sites to enhance the enzymatic degradation of PUUs. The degradation rate, the crystallinity, and mechanical properties of PUUs are tailored by the content of PHP. Meanwhile, semicrystalline PCL is not only hydrolytically degradable but also vital for shape memory. Good shape memory ability under body temperature is achieved for PUUs due to the strong interactions in hard segments for permanent crosslinking and the crystallization-melt transition of PCL to switch temporary shape. The PUUs would have a great potential in application as implanting stent. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evidence-Based Policy and Practice Leads to Changes in the Criteria for MSM to Donate Blood.

PubMed

Slowther, Anne; Watkins, Nicholas A; Kelly, Deirdre

2013-06-01

On November 7, 2011, the permanent deferral from blood donation of men who have sex with men (MSM) changed in England, Scotland and Wales, to a 12-month deferral since last relevant sexual contact. This change was made following an evidence-based policy review by the Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO). The review concluded that the available evidence supported the introduction of a 12-month fixed period deferral and that the risks associated with a 12-month deferral of MSM were equivalent to a permanent deferral. The permanent deferral for MSM was introduced in 1985 in response to the spread of acquired immunodeficiency syndrome (AIDS) caused by HIV. The change was supported by new data on the level of compliance with the permanent deferral, advances in the testing and processing of donated blood, changes in the epidemiology of sexually transmitted infections (STIs) and improved scientific knowledge. This review discusses how the decision to change the deferral period was reached and highlights some of the remaining issues relating to this contentious matter.

CRASH TEST AND EVALUATION OF RESTRAINED SAFETY-SHAPE CONCRETE BARRIERS ON CONCRETE BRIDGE DECK

DOT National Transportation Integrated Search

2018-01-01

This research designed and tested a new portable concrete barrier that meets the performance of MASH TL-4 and can be used in temporary and permanent applications on bridge decks. Additionally, this new barrier system will minimize deflection, allowin...

Blast-Absorbing Bag

NASA Technical Reports Server (NTRS)

Kahn, Jon B.

1992-01-01

Proposed expandable bag contains debris from explosion. Permanently surrounds vessel or devices prone to explosive disintegration or slipped around small bomb. Finned cells shaped like outward-opening cups. Cells built up from overlapped sheets of fabric and stitched together to form expandable polyhedral bag. Cells pentagonal, triangular or square.

Ion beams extraction and measurements of plasma parameters on a multi-frequencies microwaves large bore ECRIS with permanent magnets

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

Nozaki, Dai; Kiriyama, Ryutaro; Takenaka, Tomoya

2012-11-06

We have developed an all-permanent magnet large bore electron cyclotron resonance ion source (ECRIS) for broad ion beam processing. The cylindrically comb-shaped magnetic field configuration is adopted for efficient plasma production and good magnetic confinement. To compensate for disadvantages of fixed magnetic configuration, a traveling wave tube amplifier (TWTA) is used. In the comb-shaped ECRIS, it is difficult to achieve controlling ion beam profiles in the whole inside the chamber by using even single frequency-controllable TWTA (11-13GHz), because of large bore size with all-magnets. We have tried controlling profiles of plasma parameters and then those of extracted ion beams bymore » launching two largely different frequencies simultaneously, i.e., multi-frequencies microwaves. Here we report ion beam profiles and corresponding plasma parameters under various experimental conditions, dependence of ion beams against extraction voltages, and influence of different electrode positions on the electron density profile.« less

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

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.

Light-Induced Temperature Transitions in Biodegradable Polymer and Nanorod Composites**

PubMed Central

Hribar, Kolin C.; Metter, Robert B.; Ifkovits, Jamie L.; Troxler, Thomas

2010-01-01

Shape-memory materials (including polymers, metals, and ceramics) are those that are processed into a temporary shape and respond to some external stimuli (e.g., temperature) to undergo a transition back to a permanent shape.[1, 2] Shape memory polymers are finding use in a range of applications from aerospace to fabrics, to biomedical devices and microsystem components.[3–5] For many applications, it would be beneficial to initiate heating with an external trigger (e.g., transdermal light exposure). In this work, we formulated composites of gold nanorods (<1% by volume) and biodegradable networks, where exposure to infrared light induced heating and consequently, shape transitions. The heating is repeatable and tunable based on nanorod concentration and light intensity and the nanorods did not alter the cytotoxicity or in vivo tissue response to the networks. PMID:19408258

Additionality and permanence standards in California's Forest Offset Protocol: A review of project and program level implications.

PubMed

Ruseva, T; Marland, E; Szymanski, C; Hoyle, J; Marland, G; Kowalczyk, T

2017-08-01

A key component of California's cap-and-trade program is the use of carbon offsets as compliance instruments for reducing statewide GHG emissions. Under this program, offsets are tradable credits representing real, verifiable, quantifiable, enforceable, permanent, and additional reductions or removals of GHG emissions. This paper focuses on the permanence and additionality standards for offset credits as defined and operationalized in California's Compliance Offset Protocol for U.S. Forest Projects. Drawing on a review of the protocol, interviews, current offset projects, and existing literature, we discuss how additionality and permanence standards relate to project participation and overall program effectiveness. Specifically, we provide an overview of offset credits as compliance instruments in California's cap-and-trade program, the timeline for a forest offset project, and the factors shaping participation in offset projects. We then discuss the implications of permanence and additionality at both the project and program levels. Largely consistent with previous work, we find that stringent standards for permanent and additional project activities can present barriers to participation, but also, that there may be a trade-off between project quality and quantity (i.e. levels of participation) when considering overall program effectiveness. We summarize what this implies for California's forest offset program and provide suggestions for improvements in light of potential program diffusion and policy learning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of the influence of jogging on the shape of female foot arches.

PubMed

Maslon, Agata; Golec, Joanna; Szczygiel, Elzbieta; Czechowska, Dorota; Golec, Boguslaw

2017-12-23

Both walking and its faster, running, consist of cyclical subsequent phases of swing and support; however, they differ in their time proportions as well as magnitude of acting forces. There is a lack of studies concerning the long-term consequences of repeated jogging cycles on the function of feet and, above all, on their permanent impact on the shape of foot arches. The objective of this study was to answer the question whether regular jogging changes the shape of the transverse and medial longitudinal arches of the feet. The research material consisted of 96 women with an average age of 26.57, and included 50 actively jogging women, and 46 of non-joggers. The study was performed with the use of EMED-SF force platform. The plantar surface of the foot was divided into 10 regions according to Cavanagh, for which peak pressure and contact time were established. Two indicators were defined: metatarsal bone pressure distribution pattern acc. to Kantali, and longitudinal arch index acc. to Cavanagh. The data obtained revealed more frequent occurrence of the greatest pressure under the centrally located metatarsal heads (lack of functional foot transverse arch) among the female joggers, compared with the non-joggers. Moreover, the findings indicate the higher frequency of medial longitudinal foot arch flattening among female runners, with a great deal of consistency between both feet, whereas results for the control group show asymmetrical medial arch shapes with right foot propensity to normal arch shape and left foot tendency for excessive arch. The observed differences in feet arch shapes between female joggers and non-joggers indicate the influence of jogging on feet functional adaptations.

Impacts of changing hydrology on permanent gully growth: experimental results

NASA Astrophysics Data System (ADS)

Day, Stephanie S.; Gran, Karen B.; Paola, Chris

2018-06-01

Permanent gullies grow through head cut propagation in response to overland flow coupled with incision and widening in the channel bottom leading to hillslope failures. Altered hydrology can impact the rate at which permanent gullies grow by changing head cut propagation, channel incision, and channel widening rates. Using a set of small physical experiments, we tested how changing overland flow rates and flow volumes alter the total volume of erosion and resulting gully morphology. Permanent gullies were modeled as both detachment-limited and transport-limited systems, using two different substrates with varying cohesion. In both cases, the erosion rate varied linearly with water discharge, such that the volume of sediment eroded was a function not of flow rate, but of total water volume. This implies that efforts to reduce peak flow rates alone without addressing flow volumes entering gully systems may not reduce erosion. The documented response in these experiments is not typical when compared to larger preexisting channels where higher flow rates result in greater erosion through nonlinear relationships between water discharge and sediment discharge. Permanent gullies do not respond like preexisting channels because channel slope remains a free parameter and can adjust relatively quickly in response to changing flows.

Effect of Hygrothermal Aging on the Mechanical Properties of Fluorinated and Nonfluorinated Clay-Epoxy Nanocomposites

PubMed Central

Hamim, Salah U.; Singh, Raman P.

2014-01-01

Hydrophilic nature of epoxy polymers can lead to both reversible and irreversible/permanent changes in epoxy upon moisture absorption. The permanent changes leading to the degradation of mechanical properties due to combined effect of moisture and elevated temperature on EPON 862, Nanomer I.28E, and Somasif MAE clay-epoxy nanocomposites are investigated in this study. The extent of permanent degradation on fracture and flexural properties due to the hygrothermal aging is determined by drying the epoxy and their clay-epoxy nanocomposites after moisture absorption. Significant permanent damage is observed for fracture toughness and flexural modulus, while the extent of permanent damage is less significant for flexural strength. It is also observed that permanent degradation in Somasif MAE clay-epoxy nanocomposites is higher compared to Nanomer I.28E clay-epoxy nanocomposites. Fourier transform infrared (FTIR) spectroscopy revealed that both clays retained their original chemical structure after the absorption-desorption cycle without undergoing significant changes. Scanning electron microscopy (SEM) images of the fracture surfaces provide evidence that Somasif MAE clay particles offered very little resistance to crack propagation in case of redried specimens when compared to Nanomer I.28E counterpart. The reason for the observed higher extent of permanent degradation in Somasif MAE clay-epoxy system has been attributed to the weakening of the filler-matrix interface. PMID:27379285

Effect of Hygrothermal Aging on the Mechanical Properties of Fluorinated and Nonfluorinated Clay-Epoxy Nanocomposites.

PubMed

Hamim, Salah U; Singh, Raman P

2014-01-01

Hydrophilic nature of epoxy polymers can lead to both reversible and irreversible/permanent changes in epoxy upon moisture absorption. The permanent changes leading to the degradation of mechanical properties due to combined effect of moisture and elevated temperature on EPON 862, Nanomer I.28E, and Somasif MAE clay-epoxy nanocomposites are investigated in this study. The extent of permanent degradation on fracture and flexural properties due to the hygrothermal aging is determined by drying the epoxy and their clay-epoxy nanocomposites after moisture absorption. Significant permanent damage is observed for fracture toughness and flexural modulus, while the extent of permanent damage is less significant for flexural strength. It is also observed that permanent degradation in Somasif MAE clay-epoxy nanocomposites is higher compared to Nanomer I.28E clay-epoxy nanocomposites. Fourier transform infrared (FTIR) spectroscopy revealed that both clays retained their original chemical structure after the absorption-desorption cycle without undergoing significant changes. Scanning electron microscopy (SEM) images of the fracture surfaces provide evidence that Somasif MAE clay particles offered very little resistance to crack propagation in case of redried specimens when compared to Nanomer I.28E counterpart. The reason for the observed higher extent of permanent degradation in Somasif MAE clay-epoxy system has been attributed to the weakening of the filler-matrix interface.

Eruption of first permanent incisors and live weight gain in grazing yearling Angora goats.

PubMed

McGregor, B A; Butler, K L

2013-05-01

To investigate the effects of the timing and duration of eruption of the first permanent incisors, live weight, sex and other factors on contemporaneous live weight gain in Angora goats. Goats were previously part of a pen study on the effects of energy intake of Angora does during pregnancy and lactation on kid development. The design was 3 levels of nutrition in mid-pregnancy by 2 levels of postnatal nutrition in 17 randomised blocks. Artificial insemination, ultrasound examination and feeding does in pens enabled accurate conduct of the study. After weaning, goats were grazed in sex groups. Live weight change between 14 and 20 months of age was related to deciduous first incisor loss and permanent first incisor development and other attributes assessed before the study. Live weight change was related to the elapsed time for first permanent incisors to commence eruption and to the length of time for first permanent incisors to erupt. This response was affected by sex. Over summer and autumn, entire males with short eruption intervals gained 2-3 kg more than entire males with long eruption intervals. Females that reached first permanent incisor eruption by mid-summer had a live weight gain of 3 kg more than those that reached the same development 3 months later. Live weight change in yearling Angora goats was associated with the process of first permanent incisor eruption. In females, live weight gain was greater when first permanent incisor eruption was earlier. In males, live weight gain was greater when first permanent incisor eruption was faster. © 2013 The Authors. Australian Veterinary Journal © 2013 Australian Veterinary Association.

Silicone gel breast implants: science and testing.

PubMed

Kinney, Brian M; Jeffers, Lynn L C; Ratliff, Gregory E; Carlisle, Dan A

2014-07-01

Since the first generation of breast implants, major design innovations, including consistency of the gel, palpability and thickness of the shell, and barrier materials in the shell, have been introduced. Surgeons have not had metrics to assess and compare available implants. Research at independent laboratories included 4 tests: gel elasticity (the gel's ability to retain its shape), gel compression fracture (the resistance to permanent gel deformation), gel-shell peel (the integration of the gel with shell as a cohesive unit), and morphological analysis. Sientra's round High-Strength Cohesive (HSC) experienced the least gel elasticity (5.805 mm), whereas Allergan's round implants experienced the most (7.465 mm). Among shaped implants, Allergan 410 experienced the least gel elasticity (3.242 mm), whereas the Sientra HSC+ implant experienced the most (4.270 mm). Sientra's round (36.32 lbf) and shaped (44.16 lbf) implants demonstrated the highest resistance to gel fracture, with Allergan's implants demonstrating the least among round (23.06 lbf) implants and Mentor Contour Profile Gel (CPG) among shaped (30.45 lbf) implants. For the gel-shell peel test, Sientra's implant required over 26% greater force than Allergan's implant and over 35% greater force than Mentor's implant. Sientra's shaped implants required more than double the peel force than Allergan 410 (119% greater) and Mentor CPG (130% greater). Morphological results showed Sientra's implants preserved structural integrity (-1.10% change). The initial findings show that these implant characteristics are individual factors to be considered separately and are not necessarily correlative. Further study of implants using these and other testing techniques will help clinicians choose between implants.

Fast generation of three-dimensional computational boundary-conforming periodic grids of C-type. [for turbine blades and propellers

NASA Technical Reports Server (NTRS)

Dulikravich, D. S.

1982-01-01

A fast computer program, GRID3C, was developed to generate multilevel three dimensional, C type, periodic, boundary conforming grids for the calculation of realistic turbomachinery and propeller flow fields. The technique is based on two analytic functions that conformally map a cascade of semi-infinite slits to a cascade of doubly infinite strips on different Riemann sheets. Up to four consecutively refined three dimensional grids are automatically generated and permanently stored on four different computer tapes. Grid nonorthogonality is introduced by a separate coordinate shearing and stretching performed in each of three coordinate directions. The grids are easily clustered closer to the blade surface, the trailing and leading edges and the hub or shroud regions by changing appropriate input parameters. Hub and duct (or outer free boundary) have different axisymmetric shapes. A vortex sheet of arbitrary thickness emanating smoothly from the blade trailing edge is generated automatically by GRID3C. Blade cross sectional shape, chord length, twist angle, sweep angle, and dihedral angle can vary in an arbitrary smooth fashion in the spanwise direction.

Development of controlled solid-state alignment for alnico permanent magnets in near-final shape

DOE PAGES

Anderson, Iver E.; Kassen, Aaron G.; White, Emma M. H.; ...

2017-01-09

The 2011 price shock in the rare earth (RE) permanent magnet (PM) marketplace precipitated realization of extremely poor RE supply diversity and drove renewed research in RE-free permanent magnets such as “alnico.” Essentially, alnico is an Al-Ni-Co-Fe alloy with high magnetic saturation and T C, but low coercivity. It also was last researched extensively in the 1970’s. Currently alnico “9” magnets with the highest energy product (10MGOe) are manufactured by directional solidification to make highly aligned anisotropic magnets. This work developed novel powder processing techniques to improve on unaligned anisotropic alnico “8H” with elevated coercivity. Gas atomization was used tomore » produce pre-alloyed powder for binder-assisted compression molding of near-final shape magnets that were vacuum sintered to full density (<1% porosity). Biased grain growth with resulting grain alignment was achieved during a second solution annealing step, during which a uni-axial stress was applied along the axis parallel to the magnetization direction. Lastly, evaluation of heavily stressed samples (>250g) showed reduced overall loop squareness compared to unaligned (equiaxed) 8H due to grain rotation-induced misalignment, while low stresses improved squareness and greatly improved alignment compared to equiaxed magnets, with squareness approaching 0.30 and remanence ratio as high as 0.79.« less

Abnormal primary and permanent dentitions with ectodermal symptoms predict WNT10A deficiency.

PubMed

Bergendal, Birgitta; Norderyd, Johanna; Zhou, Xiaolei; Klar, Joakim; Dahl, Niklas

2016-11-24

The WNT10A protein is critical for the development of ectodermal appendages. Variants in the WNT10A gene may be associated with a spectrum of ectodermal abnormalities including extensive tooth agenesis. In seven patients with severe tooth agenesis we identified anomalies in primary dentition and additional ectodermal symptoms, and assessed WNT10A mutations by genetic analysis. Investigation of primary dentition revealed peg-shaped crowns of primary mandibular incisors and three individuals had agenesis of at least two primary teeth. The permanent dentition was severely affected in all individuals with a mean of 21 missing teeth. Primary teeth were most often present in positions were succedaneous teeth were missing. Furthermore, most existing molars had taurodontism. Light, brittle or coarse hair was reported in all seven individuals, hyperhidrosis of palms and soles in six individuals and nail anomalies in two individuals. The anomalies in primary dentition preceded most of the additional ectodermal symptoms. Genetic analysis revealed that all seven individuals were homozygous or compound heterozygous for WNT10A mutations resulting in C107X, E222X and F228I. We conclude that tooth agenesis and/or peg-shaped crowns of primary mandibular incisors, severe oligodontia of permanent dentition as well as ectodermal symptoms of varying severity may be predictors of bi-allelic WNT10A mutations of importance for diagnosis, counselling and follow-up.

A Survey of Permanently-Manned Lunar Base Concepts

DTIC Science & Technology

1989-06-01

of warmth and illumination. Heliostat mirr -s direct the solar beam into a periscope-like tunnel. The shape and configuration of the reflector...the tower is continuously oriented toward the sun. Installed on the tower are heliostat mirrors for a solar furnace, a cylindrical collector for lower

A new ring-shape high-temperature superconducting trapped-field magnet

NASA Astrophysics Data System (ADS)

Sheng, Jie; Zhang, Min; Wang, Yawei; Li, Xiaojian; Patel, Jay; Yuan, Weijia

2017-09-01

This paper presents a new trapped-field magnet made of second-generation high-temperature superconducting (2G HTS) rings. This so-called ring-shape 2G HTS magnet has the potential to provide much stronger magnetic fields relative to existing permanent magnets. Compared to existing 2G HTS trapped- field magnets, e.g. 2G HTS bulks and stacks, this new ring-shape 2G HTS magnet is more flexible in size and can be made into magnets with large dimensions for industrial applications. Effective magnetization is the key to being able to use trapped-field magnets. Therefore, this paper focuses on the magnetization mechanism of this new magnet using both experimental and numerical methods. Unique features have been identified and quantified for this new type of HTS magnet in the field cooling and zero field cooling process. The magnetization mechanism can be understood by the interaction between shielding currents and the penetration of external magnetic fields. An accumulation in the trapped field was observed by using multiple pulse field cooling. Three types of demagnetization were studied to measure the trapped-field decay for practical applications. Our results show that this new ring-shape HTS magnet is very promising in the trapping of a high magnetic field. As a super-permanent magnet, it will have a significant impact on large-scale industrial applications, e.g. the development of HTS machines with a very high power density and HTS magnetic resonance imaging devices.

3D Printed Anchoring Sutures for Permanent Shaping of Tissues.

PubMed

Wei, Wei; Li, Yuxiao; Yang, Huazhe; Nassab, Reza; Shahriyari, Fatemeh; Akpek, Ali; Guan, Xiaofei; Liu, Yanhui; Taranejoo, Shahrouz; Tamayol, Ali; Zhang, Yu Shrike; Khademhosseini, Ali; Jang, Hae Lin

2017-12-01

Sutures are one of the most widely used devices for adhering separated tissues after injury or surgery. However, most sutures require knotting, which can create a risk of inflammation, and can act as mechanically weak points that often result in breakage and slipping. Here, an anchoring suture is presented with a design that facilitates its propagation parallel to the suturing direction, while maximizing its resistive force against the opposite direction of external force to lock its position in tissues. Different microstructures of suture anchors are systematically designed using orthogonal arrays, and selected based on shape factors associated with mechanical strength. 3D printing is used to fabricate different types of hollow microstructured suture anchors, and optimize their structure for the effective shaping of tissues. To define the structural design for fixing tissues, the maximum force required to pull 3D printed anchors in different directions is examined with tissues. The tissue reshaping function of suture anchors is further simulated ex vivo by using swine ear, nose, and skin, and bovine muscle tendon. This study provides advantages for building functional sutures that can be used for permanently reshaping tissues with enhanced mechanical strength, eliminating the need for knotting to improve surgical efficiency. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plasma immersion ion implantation of polyurethane shape memory polymer: Surface properties and protein immobilization

NASA Astrophysics Data System (ADS)

Cheng, Xinying; Kondyurin, Alexey; Bao, Shisan; Bilek, Marcela M. M.; Ye, Lin

2017-09-01

Polyurethane-type shape memory polymers (SMPU) are promising biomedical implant materials due to their ability to recover to a predetermined shape from a temporary shape induced by thermal activation close to human body temperature and their advantageous mechanical properties including large recovery strains and low recovery stresses. Plasma Immersion Ion Implantation (PIII) is a surface modification process using energetic ions that generates radicals in polymer surfaces leading to carbonisation and oxidation and the ability to covalently immobilise proteins without the need for wet chemistry. Here we show that PIII treatment of SMPU significantly enhances its bioactivity making SMPU suitable for applications in permanent implantable biomedical devices. Scanning Electron Microscopy (SEM), contact angle measurements, surface energy measurements, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterise the PIII modified surface, including its after treatment aging kinetics and its capability to covalently immobilise protein directly from solution. The results show a substantial improvement in wettability and dramatic changes of surface chemical composition dependent on treatment duration, due to the generation of radicals and subsequent oxidation. The SMPU surface, PIII treated for 200s, achieved a saturated level of covalently immobilized protein indicating that a full monolayer coverage was achieved. We conclude that PIII is a promising and efficient surface modification method to enhance the biocompatibility of SMPU for use in medical applications that demand bioactivity for tissue integration and stability in vivo.

40 CFR 211.203 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... stimuli presented to ten different test subjects under anechoic conditions. (c) ANSI S3.19-1974. A... parameters listed in § 211.210-2(c). (f) Claim. An assertion made by a manufacturer regarding the... the ear and ear canal. The compound is subsequently permanently hardened to retain this shape. (h...

40 CFR 211.203 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... stimuli presented to ten different test subjects under anechoic conditions. (c) ANSI S3.19-1974. A... parameters listed in § 211.210-2(c). (f) Claim. An assertion made by a manufacturer regarding the... the ear and ear canal. The compound is subsequently permanently hardened to retain this shape. (h...

Researchers and stakeholders shape advances in management of tree and vine trunk-disease complexes

USDA-ARS?s Scientific Manuscript database

The grapevine trunk-disease complex limits grape production and vineyard longevity worldwide. Every vineyard in California eventually is infected by one or more trunk diseases. The causal fungi, which are taxonomically unrelated Ascomycetes, infect and then degrade the permanent woody structure of t...

Hair--Curvy or Straight; Cosmetology 1: 9205.04.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

Permanent curling and straightening require a thorough understanding of hair. Through diligent study and practice the student prepares for a profitable part of a beauty career. The course requires 135 hours of classroom-laboratory instruction. Those entering must have mastered the skills of shaping and conditioning hair. On completion of the…

40 CFR 280.71 - Permanent closure and changes-in-service.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Permanent closure and changes-in-service. 280.71 Section 280.71 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... for Occupational Safety and Health “Criteria for a Recommended Standard * * * Working in Confined...

Effects of an external magnetic field in pulsed laser deposition

NASA Astrophysics Data System (ADS)

García, T.; de Posada, E.; Villagrán, M.; Ll, J. L. Sánchez; Bartolo-Pérez, P.; Peña, J. L.

2008-12-01

Thin films were grown by pulsed laser deposition, PLD, on Si (1 0 0) substrates by the ablation of a sintered ceramic SrFe 12O 19 target with and without the presence of a nonhomogeneous magnetic field of μ0H = 0.4 T perpendicular to substrate plane and parallel to the plasma expansion axis. The field was produced by a rectangular-shaped Nd-Fe-B permanent magnet and the substrate was just placed on the magnet surface (Aurora method). An appreciable increment of optical emission due to the presence of the magnetic field was observed, but no film composition change or thickness increment was obtained. It suggests that the increment of the optical emission is due mainly to the electron confinement rather than confinement of ionic species.

Adsorbed molecules in external fields: Effect of confining potential

NASA Astrophysics Data System (ADS)

Tyagi, Ashish; Silotia, Poonam; Maan, Anjali; Prasad, Vinod

2016-12-01

We study the rotational excitation of a molecule adsorbed on a surface. As is well known the interaction potential between the surface and the molecule can be modeled in number of ways, depending on the molecular structure and the geometry under which the molecule is being adsorbed by the surface. We explore the effect of change of confining potential on the excitation, which is largely controlled by the static electric fields and continuous wave laser fields. We focus on dipolar molecules and hence we restrict ourselves to the first order interaction in field-molecule interaction potential either through permanent dipole moment or/and the molecular polarizability parameter. It is shown that confining potential shapes, strength of the confinement, strongly affect the excitation. We compare our results for different confining potentials.

5 CFR 335.101 - Effect of position change on status and tenure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... and tenure. (a) Status. A position change authorized by § 335.102 does not change the competitive... under chapter 45 of title 39, United States Code, or required by law to be filled on a permanent basis... paid under chapter 45 of title 39, United States Code, or required by law to be filled on a permanent...

5 CFR 335.101 - Effect of position change on status and tenure.

Code of Federal Regulations, 2011 CFR

2011-01-01

... and tenure. (a) Status. A position change authorized by § 335.102 does not change the competitive... under chapter 45 of title 39, United States Code, or required by law to be filled on a permanent basis... paid under chapter 45 of title 39, United States Code, or required by law to be filled on a permanent...

Inspection of Space Station Cold Plate Using Visual and Automated Holographic Techniques

NASA Technical Reports Server (NTRS)

Decker, Arthur J.; Melis, Matthew E.; Weiland, Kenneth E.

1999-01-01

Real-time holography has been used to confirm the presence of non-uniformity in the construction of an International Space Station cold plate. Ultrasonic C-scans have previously shown suspected areas of cooling fin disbonds. But both neural-net processed and visual holography did not evidence any progressive permanent changes resulting from 3000 pressurization and relaxation cycles of a Dash 8 cold plate. Neural-net and visual inspections were performed of characteristic patterns generated from electronic time-average holograms of the vibrating cold plate. Normal modes of vibration were excited at very low amplitudes for this purpose, The neural nets were trained to flag very small changes in the mode shapes as encoded in the characteristic patterns. Both the whole cold plate and a zoomed region were inspected. The inspections were conducted before, after, and during pressurization and relaxation cycles of the cold plate. A water-filled cold plate was pressurized to 120 psig (827 kPa) and relaxed for each cycle. Each cycle required 5 seconds. Both the artificial neural networks and the inspectors were unable to detect changes in the mode shapes of the relaxed cold plate. The cold plate was also inspected visually using real-time holography and double-exposure holography. Regions of non-uniformity correlating with the C-scans were apparent, but the interference patterns did not change after 3000 pressurization and relaxation cycles. These tests constituted the first practical application of a neural-net inspection technique developed originally with support from the Director's Discretionary Fund at the Glenn Research Center at Lewis Field.

Analysis of Vibration and Acoustic Noise in Permanent Magnet Motors.

NASA Astrophysics Data System (ADS)

Hwang, Sangmoon

The drive motor is a frequent source of vibration and acoustic noise in many precision spindle motors. One of the electromagnetic sources of vibration in permanent magnet motors is the torque ripple, consisting of the reluctance torque and electromagnetic torque fluctuation. This type of vibration is becoming more serious with the advent of new high-grade magnets with increased flux density. Acoustic noise of electromagnetic origin is difficult to predict and its exact mechanism is unclear. The mechanism of noise generation should be revealed to design a quieter motor which is the modern customer's demand. For motor operation at low speeds and loads, torque ripple due to the reluctance torque is often a source of vibration and control difficulty. The reluctance torque in a motor was calculated from the flux density by a finite element method and the Maxwell stress method. Effects of design parameters, such as stator slot width, permanent slot width, airgap length and magnetization direction, were investigated. Magnet pole shaping, by gradually decreasing the magnet thickness toward edges, yields a sinusoidal shape of the reluctance torque with reduced harmonics, thus reducing the vibration. This dissertation also presents two motor design techniques: stator tooth notching and rotor pole skewing with magnet pole shaping, and the effect of each method on the output torque. The analysis shows that the reluctance torque can be nearly eliminated by the suggested designs, with minimal sacrifice of the output torque. In permanent magnet DC motors, the most popular design type is the trapezoidal back electro-motive force (BEMF), for switched DC controllers. It is demonstrated that the output torque profile of one phase energized is qualitatively equivalent to the BEMF profile for motors with reduced reluctance torque. It implies that design of BEMF profile is possible by magnetic modeling of a motor, without expensive and time-consuming experiments for different designs. The effect of various design parameters on the output torque and torque ripple are discussed. Design parameters include winding patterns, magnetization direction, magnet arc length, number of segments in poles and magnet pole shaping. New designs of trapezoidal BEMF motors are proposed to reduce the electromagnetic torque ripple. Magnet stepping and magnet edge shaping with reduced arc length, significantly reduce torque ripple, with minimal sacrifice of the maximum output torque. Acoustic noise of electromagnetic origin is investigated using a magnetic frame which emulates a DC motor. The driving electromagnetic force is calculated using finite element analysis and the resulting vibration and acoustic noise is measured. Acoustic noise of purely electromagnetic origin was also tested with a DC brushless motor to confirm the results of the magnetic frame. The mechanism of noise generation in a DC motor is a quasi-static response of a stator not only at the fundamental frequency but also at higher harmonic frequencies of alternating switched DC, which is a current characteristic of a DC motor. Noise generation is significantly aggravated when some of those harmonics are close to the resonant frequencies of the stator. Therefore, acoustic noise is highly dependent upon the excitation current shape, as higher harmonics may match with resonant frequencies of the stator.

Ontogenetic study of the skull in modern humans and the common chimpanzees: neotenic hypothesis reconsidered with a tridimensional Procrustes analysis.

PubMed

Penin, Xavier; Berge, Christine; Baylac, Michel

2002-05-01

Heterochronic studies compare ontogenetic trajectories of an organ in different species: here, the skulls of common chimpanzees and modern humans. A growth trajectory requires three parameters: size, shape, and ontogenetic age. One of the great advantages of the Procrustes method is the precise definition of size and shape for whole organs such as the skull. The estimated ontogenetic age (dental stages) is added to the plot to give a graphical representation to compare growth trajectories. We used the skulls of 41 Homo sapiens and 50 Pan troglodytes at various stages of growth. The Procrustes superimposition of all specimens was completed by statistical procedures (principal component analysis, multivariate regression, and discriminant function) to calculate separately size-related shape changes (allometry common to chimpanzees and humans), and interspecific shape differences (discriminant function). The results confirm the neotenic theory of the human skull (sensu Gould [1977] Ontogeny and Phylogeny, Cambridge: Harvard University Press; Alberch et al. [1979] Paleobiology 5:296-317), but modify it slightly. Human growth is clearly retarded in terms of both the magnitude of changes (size-shape covariation) and shape alone (size-shape dissociation) with respect to the chimpanzees. At the end of growth, the adult skull in humans reaches an allometric shape (size-related shape) which is equivalent to that of juvenile chimpanzees with no permanent teeth, and a size which is equivalent to that of adult chimpanzees. Our results show that human neoteny involves not only shape retardation (paedomorphosis), but also changes in relative growth velocity. Before the eruption of the first molar, human growth is accelerated, and then strongly decelerated, relative to the growth of the chimpanzee as a reference. This entails a complex process, which explains why these species reach the same overall (i.e., brain + face) size in adult stage. The neotenic traits seem to concern primarily the function of encephalization, but less so other parts of the skull. Our results, based on the discriminant function, reveal that additional structural traits (corresponding to the nonallometric part of the shape which is specific to humans) are rather situated in the other part of the skull. They mainly concern the equilibrium of the head related to bipedalism, and the respiratory and masticatory functions. Thus, the reduced prognathism, the flexed cranial base (forward position of the foramen magnum which is brought closer to the palate), the reduced anterior portion of the face, the reduced glabella, and the prominent nose mainly correspond to functional innovations which have nothing to do with a neotenic process in human evolution. The statistical analysis used here gives us the possibility to point out that some traits, which have been classically described as paedomorphic because they superficially resemble juvenile traits, are in reality independent of growth. Copyright 2002 Wiley-Liss, Inc.

Reversible TAD Chemistry as a Convenient Tool for the Design of (Re)processable PCL-Based Shape-Memory Materials.

PubMed

Defize, Thomas; Riva, Raphaël; Thomassin, Jean-Michel; Alexandre, Michaël; Herck, Niels Van; Prez, Filip Du; Jérôme, Christine

2017-01-01

A chemically cross-linked but remarkably (re)processable shape-memory polymer (SMP) is designed by cross-linking poly(ε-caprolactone) (PCL) stars via the efficient triazolinedione click chemistry, based on the very fast and reversible Alder-ene reaction of 1,2,4-triazoline-3,5-dione (TAD) with indole compounds. Typically, a six-arm star-shaped PCL functionalized by indole moieties at the chain ends is melt-blended with a bisfunctional TAD, directly resulting in a cross-linked PCL-based SMP without the need of post-curing treatment. As demonstrated by the stress relaxation measurement, the labile character of the TAD-indole adducts under stress allows for the solid-state plasticity reprocessing of the permanent shape at will by compression molding of the raw cross-linked material, while keeping excellent shape-memory properties. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stability of polar frosts in spherical bowl-shaped craters on the moon, Mercury, and Mars

NASA Technical Reports Server (NTRS)

Ingersoll, Andrew P.; Svitek, Tomas; Murray, Bruce C.

1992-01-01

A model of spherical bowl-shaped craters is described and applied to the moon, Mercury, and Mars. The maximum temperature of permanently shadowed areas are calculated using estimates of the depth/diameter ratios of typical lunar bowl-shaped craters and assuming a saturated surface in which the craters are completely overlapping. For Mars, two cases are considered: water frost in radiative equilibrium and subliming CO2 frost in vapor equilibrium. Energy budgets and temperatures are used to determine whether a craterlike depression loses mass faster or slower than a flat horizontal surface. This reveals qualitatively whether the frost surface becomes rougher or smoother as it sublimes.

78 FR 46417 - Proposed Information Collection (Application for Change of Permanent Plan (Medical)); Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

... (Application for Change of Permanent Plan (Medical)); Comment Request AGENCY: Veterans Benefits Administration... collection of certain information by the agency. Under the Paperwork Reduction Act (PRA) of 1995, Federal agencies are required to publish notice in the Federal Register concerning each proposed collection of...

76 FR 2757 - Proposed Information Collection (Application for Change of Permanent Plan (Medical); Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

... (Application for Change of Permanent Plan (Medical); Comment Request AGENCY: Veterans Benefits Administration... collection of certain information by the agency. Under the Paperwork Reduction Act (PRA) of 1995, Federal agencies are required to publish notice in the Federal Register concerning each proposed collection of...

Fluorescent lamp unit with magnetic field generating means

DOEpatents

Grossman, Mark W.; George, William A.

1989-01-01

A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope.

Fluorescent lamp unit with magnetic field generating means

DOEpatents

Grossman, M.W.; George, W.A.

1989-08-08

A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope. 4 figs.

Variability of the cranial and dental phenotype in Williams syndrome.

PubMed

Axelsson, Stefan

2005-01-01

Williams syndrome (WS) is a rare congenital disorder involving the cardiovascular system, connective tissue, and the central nervous system, resulting in mild to moderate mental retardation, a specific cognitive profile, unique personality characteristics, distinctive facial features, and cardiovascular disease. The majority of individuals with a clinical diagnosis of WS have a contiguous gene deletion at chromosome 7 (7q11.23). Physical features include characteristic facial features with full prominent cheeks, wide mouth, long philtrum, small nose with depressed nasal bridge, heavy orbital ridges, medial eyebrow flare, dental abnormalities, hoarse voice, growth retardation, and cardiovascular abnormalities (most commonly supravalvular aortic stenosis and/or peripheral pulmonary artery stenosis). The cognitive profile is distinctive, consisting of strengths in auditory memory, language, and face-processing, but extreme weakness in visuospatial, numerical and problem-solving abilities. Neurological studies have identified a significantly decreased brain volume in adult individuals with WS with relatively normal development of the limbic, frontal and cerebellar structures. The aims were to analyse the neurocranium, the craniofacial region, and the dentition in a well defined Norwegian group of individuals with WS. In order to accomplish this, normative cephalometric standards for the neurocranium, including the cranial base and the sella turcica, were established for Norwegian males and females from 6 to 21 years of age, using lateral radiographic cephalograms from the Oslo University Craniofacial Growth Archive. The study material comprised radiographic lateral cephalograms, orthopantomograms and dental casts from 62 individuals with WS ranging from 4 to 44 years. The lateral cephalograms, orthopantomograms and dental casts were analysed using standard methods reported in the literature. Neurocranium: The results from the cephalometric analyses showed that the size and shape of the neurocranium in WS differed from normal controls. A flattening of the superior aspect of the parietal bone was found and the posterior prominence of the occipital bone was larger. These findings were in concordance with published neuroanatomical/neuropathological studies on WS and fit well with the reported anatomical aberrations in the WS brain, e.g. a smaller brain volume where some parts are of relatively normal size while others are decreased. The anterior and posterior cranial base was shorter in WS, but with a normal cranial base angle. The thickness of the calvarian bones, especially the frontal and occipital bones, was greater in WS than in normal controls. Sella turcica: The size of the sella turcica was somewhat smaller in WS compared with normal controls, though not significant. Aberrant types of shape of the sella turcica in WS are demonstrated. The correlation between prenatal malformation in the pituitary gland/sella turcica and the postnatal morphology of the sella turcica is discussed. The craniofacial skeleton: Two areas, in addition to the cranial base, have been identified to contribute to the characteristic facial appearance in WS; the anterior inclination of the maxilla, and the shape of the mandible. The severely deficient bony chin in combination with the high mandibular plane angle can explain earlier clinical descriptions of a retrusive mandible in WS. Frequent mouth breathing during childhood and the smaller cranial base may be associated with the characteristic craniofacial pattern. Dentition: In individuals with WS over 10 years of age 40.5 per cent had agenesis of one or more permanent teeth and 11.9 percent had agenesis of 6 teeth or more. The missing permanent teeth in the maxilla most commonly included 2nd premolars, 1st premolars, and lateral incisors. In the mandible most commonly 2nd premolars, 1st premolars, and central incisors were absent. The tooth crowns of permanent teeth were smaller, both in the mesio-distal and labio-lingual dimension. The permanent tooth crowns have several characteristic deviations from normal shape; especially incisors in both jaws were tapered or screwdriver-shaped. An evaluation of taurodontism on permanent molars was performed. However, most of the molars rated as being taurodontic had short total tooth lengths and could thus be rated taurodontic without meeting the classical definition. These studies have shown aberrations in the neurocranium including the sella turcica in WS not previously reported. In the craniofacial skeleton specific traits have been identified to contribute to the characteristic facial appearance in WS. Dental aberrations in the permanent dentition including agenesis, smaller size, and aberrant shape of teeth, are common in WS.

Rapid Palatal Expansion in the absence of posterior cross-bite to intercept maxillary incisor crowding in the mixed dentition: a CBCT evaluation of spontaneous changes of untouched permanent molars.

PubMed

Rosa, M; Lucchi, P; Manti, G; Caprioglio, A

2016-12-01

The aim of this study was to investigate the reaction of untouched permanent molars following RPE, anchored on deciduous teeth in the early mixed dentition, aimed to solve maxillary anterior crowding in the absence of posterior cross-bite. A prospective clinical trial comprised 35 consecutive patients (20 males and 15 females) treated by the same orthodontist (MR). All patients showed crowding of the upper permanent incisors in the early mixed dentition in the absence of posterior cross-bite. RPE was anchored on second deciduous molars and on the deciduous canines. CBCT was taken before and after the removal of the RPE appliance. The transverse linear changes in width and the variation in the torque of the permanent molars were measured in the coronal plane. Relief of incisor crowding was found in all patients. The transverse width between permanent molars increased significantly. The apices of the upper permanent molars spontaneously expanded more than the crowns, while the opposite happened on the lower permanent molars. Moreover, the untouched upper permanent molars spontaneously uprighted palatally, while the lower permanent molars spontaneously uprighted buccally. The variation in the torque of the permanent molars mirrored transverse normal growth. In the early mixed dentition and in the absence of posterior cross-bite, it is possible to expand transversally the palate while uprighting the upper permanent molars in the opposite direction. RPE anchored on the deciduous teeth in the early mixed dentition, in the absence of posterior cross-bite, provides an "anticipation of transverse growth" and could be indicated to expand the anterior portion of the maxillary arch perimeter to solve upper incisor crowding.

Okavango Delta, Botswana as seen from STS-66 shuttle Atlantis

NASA Technical Reports Server (NTRS)

1994-01-01

This November 1994 view looking south-southeast shows clouds over the Okavango Delta area of northern Botswana. The Okavango is one of the wilder, less spoiled regions of Africa. The Okavango River (lower left of view) brings water from the high, wet plateaus of Angola into the Kalahari Dessert, and enormous inland basin. As a result of a series of small faults (upper center of the view) related to the African Rift System, the river is dammed up in the form of a swampy inland delta. The visual patterns of the area are strongly linear: straight sand dunes occur in many places and can be seen across the bottom portion of the photograph. Numerous brush-fire scars produce a complex, straight-edged pattern over much of the lower portion of this view. Lake Ngami (upper right of view) was once permanently full as late as the middle 1800s. Changes in the climate of the area over the last 100 years has changed the size and shape of the inland delta.

Remeasurement of permanent vegetation plots in the Great Smoky Mountains National Park, Tennessee, USA, and the implications of climatic changes on vegetation. Environmental Sciences Division publication No. 1111

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

Becking, R. W.; Olson, J. S.

1978-03-01

This report summarizes field work over two summers (1976 and 1977) to relocate, monument and reinventory permanent vegetation plots in the Great Smoky Mountains National Park. These plots were first established by the senior author and R.H. Whittaker in 1959-62. The inventory results are discussed in terms of vegetation changes in high-altitudinal forest ecosystems, in particular the spruce-fir forests, and the factors, climate shift and biotic and abiotic agents, bringing about vegetation change. A second aspect of the report summarizes experience and offers recommendations for establishment of permanent vegetation plots for the purpose of providing a monitoring tool with whichmore » to measure long-term ecological change.« less

40 CFR 74.46 - Opt-in source permanent shutdown, reconstruction, or change in affected status.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Opt-in source permanent shutdown, reconstruction, or change in affected status. 74.46 Section 74.46 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Tracking and Transfer...

A guide for recording esthetic and biologic changes with photographs

Treesearch

Arthur W. Magill; R.H. Twiss

1965-01-01

Photography has long been a useful tool for recording and analyzing environmental conditions. Permanent camera points can be established to help detect ,and analyze changes in the esthetics and ecology of wildland resources. This note describes the usefulness of permanent camera points and outlines procedures for establishing points and recording data.

40 CFR 74.46 - Opt-in source permanent shutdown, reconstruction, or change in affected status.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Opt-in source permanent shutdown, reconstruction, or change in affected status. 74.46 Section 74.46 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Tracking and Transfer...

Dairy farming on permanent grassland: can it keep up?

PubMed

Kellermann, M; Salhofer, K

2014-10-01

Based on an extensive data set for southern Germany, we compared the productive performance of dairy farms that operate solely on permanent grassland and dairy farms using fodder crops from arable land. We allowed for heterogeneous production technologies and identified more intensive and extensive production systems for both types of farms, whereby we based our notion of intensive versus extensive dairy production on differences in stocking density and milk yield per cow and year. To be able to compare the productivity levels and productivity developments of the various groups of farms, we developed a group- and chain-linked multilateral productivity index. We also analyzed how technical change, technical efficiency change, and a scale change effect contribute to productivity growth between the years 2000 and 2008. Our results revealed that permanent grassland farms can generally keep up with fodder-crop farms, even in an intensive production setting. However, extensively operating farms, especially those on permanent grassland, significantly lag behind in productivity and productivity change and run the risk of losing ground. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Modern Special Collections: Embracing the Future While Taking Care of the Past

ERIC Educational Resources Information Center

Evans, Meredith R.

2015-01-01

As managers of special collections engage with evolving formats and technologies, it is imperative that these professionals remain well versed in papyrus, paper, and principles that inform archival work. The permanence of this content defines our past, informs our present, and shapes our future. However, a constricting interpretation of archival…

Magnetowetting and sliding motion of a sessile ferrofluid droplet in the presence of a permanent magnet.

PubMed

Nguyen, Nam-Trung; Zhu, Guiping; Chua, Yong-Chin; Phan, Vinh-Nguyen; Tan, Say-Hwa

2010-08-03

Motion of a droplet on a planar surface has applications in droplet-based lab on a chip technology. This paper reports the experimental results of the shape, contact angles, and motion of ferrofluid droplets driven by a permanent magnet on a planar homogeneous surface. The water-based ferrofluid in use is a colloidal suspension of single-domain magnetic nanoparticles. The effect of the magnetic field on the apparent contact angle of the ferrofluid droplet was first investigated. The results show that an increasing magnetic flux decreases the apparent contact angle of a sessile ferrofluid droplet. Next, the dynamic contact angle was investigated by observing the shape and the motion of a sessile ferrofluid droplet. The advancing and receding contact angles of the moving ferrofluid were measured at different moving speeds and magnetic field strengths. The measured contact angles were used to estimate the magnitude of the forces involved in the sliding motion. Scaling analysis was carried out to derive the critical velocity, beyond which the droplet is not able to catch up with the moving magnet.

Studies of the shapes of heavy pear-shaped nuclei at ISOLDE

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

Butler, P. A., E-mail: peter.butler@liverpool.ac.uk

2016-07-07

For certain combinations of protons and neutrons there is a theoretical expectation that the shape of nuclei can assume octupole deformation, which would give rise to reflection asymmetry or a ”pear-shape” in the intrinsic frame, either dynamically (octupole vibrations) or statically (permanent octupole deformation). I will briefly review the historic evidence for reflection asymmetry in nuclei and describe how recent experiments carried out at REX-ISOLDE have constrained nuclear theory and how they contribute to tests of extensions of the Standard Model. I will also discuss future prospects for measuring nuclear shapes from Coulomb Excitation: experiments are being planned that willmore » exploit beams from HIE-ISOLDE that are cooled in the TSR storage ring and injected into a solenoidal spectrometer similar to the HELIOS device developed at the Argonne National Laboratory.« less

The Permanence of Mental Objects: Testing Magical Thinking on Perceived and Imaginary Realities

ERIC Educational Resources Information Center

Subbotsky, Eugene

2005-01-01

This study tested participants' preparedness to acknowledge that an object could change as a result of magical intervention. Six- and 9-year-old children and adults treated perceived and imagined objects as being equally permanent. Adults treated a fantastic object as significantly less permanent than either perceived or imagined objects. Results…

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.

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

Qu, Wentao, E-mail: wtqu@xsyu.edu.cn

The phase transformation and microstructures of the deformed Ti-30Zr-5Nb shape memory alloy were investigated. The X-ray diffraction measurements indicated that the Ti-30Zr-5Nb alloy was composed of a single orthorhombic α″-martensite phase. The alloy exhibited one yielding behavior in the tensile test, with a critical stress of ~ 600 MPa and a tensile strain of approximately 15%. A shape memory recovery accompanied by a permanent strain was exhibited in the deformed alloys when heated at 873 K. The permanent strain increased with increasing pre-strain. The microstructure evolution of the deformed alloy was investigated by transmission electron microscopy. The results showed thatmore » the martensite reorientation occurred and the dislocations were generated during deformation. The alloy displayed a reversible martensite transformation start temperature as high as 763 K. However, no strain-induced martensite stabilization was found in the deformed alloy with different pre-strain levels, potentially because the large chemical energy of the Ti-30Zr-5Nb alloy depressed the effects of the elastic energy and the dissipative energy. - Highlights: • Ti-30Zr-5Nb alloy is composed of single orthorhombic α″-martensite phase with M{sub s} of 721 K. • No martensite stabilization has been found in Ti-30Zr-5Nb alloy with different pre-strain. • Ti-30Zr-5Nb shows the maximum shape memory effect of 2.75% with a pre-strain of 8%.« less

Effect of Dimension and Shape of Magnet on the Performance AC Generator with Translation Motion

NASA Astrophysics Data System (ADS)

Indriani, A.; Dimas, S.; Hendra

2018-02-01

The development of power plants using the renewable energy sources is very rapid. Renewable energy sources used solar energy, wind energy, ocean wave energy and other energy. All of these renewable energy sources require a processing device or a change of motion system to become electrical energy. One processing device is a generator which have work principle of converting motion (mechanical) energy into electrical energy with rotary shaft, blade and other motion components. Generator consists of several types of rotation motion and linear motion (translational). The generator have components such as rotor, stator and anchor. In the rotor and stator having magnet and winding coil as an electric generating part of the electric motion force. Working principle of AC generator with linear motion (translation) also apply the principle of Faraday that is using magnetic induction which change iron magnet to produce magnetic flux. Magnetic flux is captured by the stator to be converted into electrical energy. Linear motion generators consist of linear induction machine, wound synchronous machine field, and permanent magnet synchronous [1]. Performance of synchronous generator of translation motion is influenced by magnet type, magnetic shape, coil winding, magnetic and coil spacing and others. In this paper focus on the neodymium magnet with varying shapes, number of coil windings and gap of magnetic distances. This generator work by using pneumatic mechanism (PLTGL) for power plants system. Result testing of performance AC generator translation motion obtained that maximum voltage, current and power are 63 Volt for diameter winding coil 0.15 mm, number of winding coil 13000 and distance of magnet 20 mm. For effect shape of magnet, maximum voltage happen on rectangle magnet 30x20x5 mm with 4.64 Volt. Voltage and power on effect of diameter winding coil is 14.63 V and 17.82 W at the diameter winding coil 0.7 and number of winding coil is 1260 with the distance of magnet 25 mm.

The battle scars of pregnancy: can they be prevented?

PubMed

Razi, Emma

2012-05-01

I have feared developing stretch marks since my first pregnancy. Getting to grips with my changing shape was a big challenge, but I was safe in the knowledge that post-pregnancy I could work towards losing the weight. But stretch marks are permanent, and to me-disfiguring. I researched how stretch marks can be prevented and after finding little evidence for a particular cream or lotion: I scanned forums and asked friends what worked for them. Many people claimed that by keeping skin hydrated and supple, the dreaded stretch marks can be kept at bay or at least to a minimum. So I opted for regularly massaging oil across vulnerable areas and maintaining a balanced diet, including drinking lots of water. I was lucky the first time round; time will tell if my skincare routine will work for my second pregnancy.

Irreversible Processes in Ionized Gases

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

Balescu, R.

1960-01-01

The general theory of irreversible processes, developed by Prigogine and Balescu, is applied to the case of long range interactions in ionized gases. A similar diagram technique permits the systematic selection of all the contributions to the evolution of the distribution function, a an order of approximation equivalent to Debye's equilibrium theory. The infinite series which appear in this way can be summed exactly. The resulting evolution equations have a clear physical significance: they describe interactions of "quasi particles," which are electrons or ions "dressed" by their polarization clouds. These clouds are not a permanent feature, as in equilibrium theory,more » but have a nonequilibrium, changing shape, distorted by the motions of the particles. From the mathematical point of view, these equations exhibit a new type of nonlinearity, which is very directly related to the collective nature of the interactions.« less

Adsorbed molecules in external fields: Effect of confining potential.

PubMed

Tyagi, Ashish; Silotia, Poonam; Maan, Anjali; Prasad, Vinod

2016-12-05

We study the rotational excitation of a molecule adsorbed on a surface. As is well known the interaction potential between the surface and the molecule can be modeled in number of ways, depending on the molecular structure and the geometry under which the molecule is being adsorbed by the surface. We explore the effect of change of confining potential on the excitation, which is largely controlled by the static electric fields and continuous wave laser fields. We focus on dipolar molecules and hence we restrict ourselves to the first order interaction in field-molecule interaction potential either through permanent dipole moment or/and the molecular polarizability parameter. It is shown that confining potential shapes, strength of the confinement, strongly affect the excitation. We compare our results for different confining potentials. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface integrity and corrosion performance of biomedical magnesium-calcium alloy processed by hybrid dry cutting-finish burnishing.

PubMed

Salahshoor, M; Li, C; Liu, Z Y; Fang, X Y; Guo, Y B

2018-02-01

Biodegradable magnesium-calcium (MgCa) alloy is a very attractive orthopedic biomaterial compared to permanent metallic alloys. However, the critical issue is that MgCa alloy corrodes too fast in the human organism. Compared to dry cutting, the synergistic dry cutting-finish burnishing can significantly improve corrosion performance of MgCa0.8 (wt%) alloy by producing a superior surface integrity including good surface finish, high compressive hook-shaped residual stress profile, extended strain hardening in subsurface, and little change of grain size. A FEA model was developed to understand the plastic deformation of MgCa materials during burnishing process. The measured polarization curves, surface micrographs, and element distributions of the corroded surfaces by burnishing show an increasing and uniform corrosion resistance to simulated body fluid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Body motion for powering biomedical devices.

PubMed

Romero, Edwar; Warrington, Robert O; Neuman, Michael R

2009-01-01

Kinetic energy harvesting has been demonstrated as a useful technique for powering portable electronic devices. Body motion can be used to generate energy to power small electronic devices for biomedical applications. These scavengers can recharge batteries, extending their operation lifetime or even replace them. This paper addresses the generation of energy from human activities. An axial flux generator is presented using body motion for powering miniature biomedical devices. This generator presents a gear-shaped planar coil and a multipole NdFeB permanent magnet (PM) ring with an attached eccentric weight. The device generates energy by electromagnetic induction on the planar coil when subject to a changing magnetic flux due to the generator oscillations produced by body motion. A 1.5 cm(3) prototype has generated 3.9 microW of power while walking with the generator placed laterally on the ankle.

Access 1996: A directory of permanent plots which monitor flora, fauna, climate, hydrology, soil, geology, and the effects of anthropogenic changes at 132 biosphere reserves in 27 countries

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

NONE

1996-07-01

This directory summarizes information about environmental data collected in permanent monitoring and research plots in 132 biosphere reserves in Canada, the United States, and 25 European countries. The text of the directory is organized alphabetically by country and, within each country, alphabetically according to the name of the biosphere reserve. Tabular summaries of information on permanent plots are provided. The summaries are organized topically . A general summary of basic information on permanent plots is followed by more detailed information on permanent plots dedicated primarily to monitroing and research on particular topics.

Robotic Thumb Assembly

NASA Technical Reports Server (NTRS)

Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor); Goza, S. Michael (Inventor)

2013-01-01

An improved robotic thumb for a robotic hand assembly is provided. According to one aspect of the disclosure, improved tendon routing in the robotic thumb provides control of four degrees of freedom with only five tendons. According to another aspect of the disclosure, one of the five degrees of freedom of a human thumb is replaced in the robotic thumb with a permanent twist in the shape of a phalange. According to yet another aspect of the disclosure, a position sensor includes a magnet having two portions shaped as circle segments with different center points. The magnet provides a linearized output from a Hall effect sensor.

Local structuring factors of invertebrate communities in ephemeral freshwater rock pools and the influence of more permanent water bodies in the region

USGS Publications Warehouse

Jocque, M.; Graham, T.; Brendonck, L.

2007-01-01

We used three isolated clusters of small ephemeral rock pools on a sandstone flat in Utah to test the importance of local structuring processes on aquatic invertebrate communities. In the three clusters we characterized all ephemeral rock pools (total: 27) for their morphometry, and monitored their water quality, hydrology and community assemblage during a full hydrocycle. In each cluster we also sampled a set of more permanent interconnected freshwater systems positioned in a wash, draining the water from each cluster of rock pools. This design allowed additional testing for the potential role of more permanent water bodies in the region as source populations for the active dispersers and the effect on the community structure in the rock pools. Species richness and community composition in the rock pools correlated with level of permanence and the ammonia concentration. The length of the rock pool inundation cycle shaped community structure, most probably by inhibiting colonization by some taxa (e.g. tadpoles and insect larvae) through developmental constraints. The gradient in ammonia concentrations probably reflects differences in primary production. The more permanent water bodies in each wash differed both environmentally and in community composition from the connected set of rock pools. A limited set of active dispersers was observed in the rock pools. Our findings indicate that aquatic invertebrate communities in the ephemeral rock pools are mainly structured through habitat permanence, possibly linked with biotic interactions and primary production. ?? 2007 Springer Science+Business Media B.V.

Evaluation of the Permanence of Land Use Change Induced by Payments for Environmental Services in Quindío, Colombia.

PubMed

Pagiola, Stefano; Honey-Rosés, Jordi; Freire-González, Jaume

2016-01-01

The effectiveness of conservation interventions such as Payments for Environmental Services (PES) is often evaluated--if it is evaluated at all--only at the completion of the intervention. Since gains achieved by the intervention may be lost after it ends, even apparently successful interventions may not result in long-term conservation benefits, a problem known as that of permanence. This paper uses a unique dataset to examine the permanence of land use change induced by a short-term, asset-building PES program implemented in Quindío, Colombia, between 2003 and 2008. This the first PES program to have a control group for comparison. Under this program, PES had been found to have a positive and highly significant impact on land use. To assess the long-term permanence of these changes, both PES recipients and control households were re-surveyed in 2011, four years after the last payment was made. We find that the land use changes that had been induced by PES were broadly sustained in intervening years, with minor differences across specific practices and sub-groups of participants, indicating that these changes were in fact permanent. The patterns of change in the period after the PES program was completed also help better understand the reasons for the program's success. These results suggest that, at least in the case of productive land uses such as silvopastoral practices under conditions such as those at the study site, asset-building PES programs can be effective at encouraging land owners to adopt environmentally-beneficial land management practices and that the benefits will persist after payments cease.

Job Permanency: The Academic Librarian's Dilemma is the Administrator's Challenge for the 1980s.

ERIC Educational Resources Information Center

Rutledge, Diane B.

1981-01-01

Recommends that library managers make inexpensive but enlightened changes in administrative policies and work environment to encourage professional development of permanent staff. References are listed. (RAA)

Porous inorganic-organic shape memory polymers.

PubMed

Zhang, Dawei; Burkes, William L; Schoener, Cody A; Grunlan, Melissa A

2012-06-21

Thermoresponsive shape memory polymers (SMPs) are a type of stimuli-sensitive materials that switch from a temporary shape back to their permanent shape upon exposure to heat. While the majority of SMPs have been fabricated in the solid form, porous SMP foams exhibit distinct properties and are better suited for certain applications, including some in the biomedical field. Like solid SMPs, SMP foams have been restricted to a limited group of organic polymer systems. In this study, we prepared inorganic-organic SMP foams based on the photochemical cure of a macromer comprised of inorganic polydimethylsiloxane (PDMS) segments and organic poly(ε-caprolactone) (PCL) segments, diacrylated PCL(40)-block-PDMS(37)-block-PCL(40). To achieve tunable pore size with high interconnectivity, the SMP foams were prepared via a refined solvent-casting/particulate-leaching (SCPL) method. By varying design parameters such as degree of salt fusion, macromer concentration in the solvent and salt particle size, the SMP foams with excellent shape memory behavior and tunable pore size, pore morphology, and modulus were obtained.

The Beringian coevolution project: Holistic collections of mammals and associated parasites reveal novel perspectives on evolutionary and environmental change in the North

USGS Publications Warehouse

Cook, Joseph A.; Galbreath, Kurt E.; Campbell, Mariel; Carrière, Susanne; Colella, Jocelyn P.; Dawson, Natalie G.; Dunnum, Jonathan L.; Eckerlin, Ralph P.; Greiman, Stephen E.; Fedorov, Vadim B.; Haas, Genevieve M. S.; Haukisalmi, Voitto; Henttonen, Heikki; Hope, Andrew G.; Jackson, Donavan; Jung, Tom; Koehler, Anson V.; Kinsella, John M.; Krejsa, Dianna; Kutz, Susan J.; Liphardt, Schuyler; MacDonald, Stephen O.; Malaney, Jason L.; Makarikov, Arseny; Martin, Jon; McLean, Bryan S.; Mulders, Robert; Nyamsuren, Batsaikhan; Talbot, Sandra L.; Tkach, Vasyl V.; Tsvetkova, Albina; Toman, Heather M.; Waltari, Eric C.; Whitman, Jackson S.; Hoberg, Eric P.

2017-01-01

The Beringian Coevolution Project (BCP), a field program underway in the high northern latitudes since 1999, has focused on building key scientific infrastructure for integrated specimen-based studies on mammals and their associated parasites. BCP has contributed new insights across temporal and spatial scales into how ancient climate and environmental change have shaped faunas, emphasizing processes of assembly, persistence, and diversification across the vast Beringian region. BCP collections also represent baseline records of biotic diversity from across the northern high latitudes at a time of accelerated environmental change. These specimens and associated data form an unmatched resource for identifying hidden diversity, interpreting past responses to climate oscillations, documenting contemporary conditions, and anticipating outcomes for complex biological systems in a regime of ecological perturbation. Because of its dual focus on hosts and parasites, the BCP record also provides a foundation for comparative analyses that can document the effects of dynamic change on the geographic distribution, transmission dynamics, and emergence of pathogens. By using specific examples from carnivores, shrews, lagomorphs, rodents and their associated parasites, we demonstrate how broad, integrated field collections provide permanent infrastructure that informs policy decisions regarding human impact and the effect of climate change on natural populations.

A multinational Andean genetic and health program: growth and development in an hypoxic environment.

PubMed

Mueller, W H; Schull, V N; Schull, W J; Soto, P; Rothhammer, F

1978-07-01

In 1972 a multidisciplinary study sought to assess the health status of the indigenous peoples of the Department of Arica in northern Chile, the Aymara, and to relate disease, morphological, physiological and biochemical variation, to the wide changes in altitude of the region. Presented here are the morphological changes which accompany age, altitude and ethnicity amoung 1047 children and adults, permanent residents of the coast, sierra and altiplano. At comparable ages, high-altitude residents were shorter, lighter and leaner but with more expansive and rounder chests than sea-level controls. None of these effects was systematically related to ethnicity (Spanish-Aymara surname), although when stature was held constant, children with greater Aymara ancestry had largest chest circumferences and longer bones. These results suggest that (1) altitude confers allometric growth changes (expensive growth of the chest and diminished growth of the structures less related to oxygen transport); and (2) size changes associated with altitude are acquired during development while shape changes may be under genetic control. Altitude appears to account for less of the variation in growth in this relatively homogeneous Chilean sample than has been reported for other Andean samples, suggesting other concomitants confounding the effects of hypoxia in Andean South America.

Aetiology, incidence and morphology of the C-shaped root canal system and its impact on clinical endodontics

PubMed Central

Kato, A; Ziegler, A; Higuchi, N; Nakata, K; Nakamura, H; Ohno, N

2014-01-01

The C-shaped root canal constitutes an unusual root morphology that can be found primarily in mandibular second permanent molars. Due to the complexity of their structure, C-shaped root canal systems may complicate endodontic interventions. A thorough understanding of root canal morphology is therefore imperative for proper diagnosis and successful treatment. This review aims to summarize current knowledge regarding C-shaped roots and root canals, from basic morphology to advanced endodontic procedures. To this end, a systematic search was conducted using the MEDLINE, BIOSIS, Cochrane Library, EMBASE, Google Scholar, Web of Science, PLoS and BioMed Central databases, and many rarely cited articles were included. Furthermore, four interactive 3D models of extracted teeth are introduced that will allow for a better understanding of the complex C-shaped root canal morphology. In addition, the present publication includes an embedded best-practice video showing an exemplary root canal procedure on a tooth with a pronounced C-shaped root canal. The survey of this unusual structure concludes with a number of suggestions concerning future research efforts. PMID:24483229

C-shaped maxillary permanent first molar: a case report and literature review.

PubMed

Martins, Jorge N R; Quaresma, Sérgio; Quaresma, Maria Carlos; Frisbie-Teel, Jared

2013-12-01

The C-shaped configuration is rare in the upper first molar.The purpose of this article is to present 2 cases diagnosed during endodontic therapy and perform a literature review of this anatomy in the upper first molar. Endodontic therapy was performed by using a dental operating microscope and a cone-beam computed tomography analysis for better understanding of this anatomy. A literature search was conducted to identify and compare all the published cases of C-shaped upper first molar. Before the cases reported in this article, only 5 cases were available in the published literature. Three different types of C-shaped configurations in the upper first molar have been presented. The C-shaped maxillary first molar is a rare anatomic configuration. The use of the dental operating microscope may help in the endodontic therapy of these cases. Three types of C-shaped configurations have been reported; the fusion of the distobuccal root with the palatal root appears to be the most usual one. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Optimization of Interior Permanent Magnet Motor by Quality Engineering and Multivariate Analysis

NASA Astrophysics Data System (ADS)

Okada, Yukihiro; Kawase, Yoshihiro

This paper has described the method of optimization based on the finite element method. The quality engineering and the multivariable analysis are used as the optimization technique. This optimizing method consists of two steps. At Step.1, the influence of parameters for output is obtained quantitatively, at Step.2, the number of calculation by the FEM can be cut down. That is, the optimal combination of the design parameters, which satisfies the required characteristic, can be searched for efficiently. In addition, this method is applied to a design of IPM motor to reduce the torque ripple. The final shape can maintain average torque and cut down the torque ripple 65%. Furthermore, the amount of permanent magnets can be reduced.

Core losses of an inverter-fed permanent magnet synchronous motor with an amorphous stator core under no-load

NASA Astrophysics Data System (ADS)

Denis, Nicolas; Kato, Yoshiyuki; Ieki, Masaharu; Fujisaki, Keisuke

2016-05-01

In this paper, an interior permanent magnet synchronous motor (IPMSM) with a stator core made of amorphous magnetic material (AMM) is presented. The IPMSM is driven by a voltage source three-phase inverter with classical pulse width modulation (PWM) control. The core losses under no-load condition are measured by experiment and compared to an equivalent IPMSM with a stator core made of NO steel. Under these conditions, the core losses are influenced by the stator, rotor and magnet shapes but also by the PWM carrier signal that implies a high frequency harmonic in the magnetic flux density. It is demonstrated that the AMM can reduce the core losses by about 56 %.

Development of a compact permanent magnet helicon plasma source for ion beam bioengineering.

PubMed

Kerdtongmee, P; Srinoum, D; Nisoa, M

2011-10-01

A compact helicon plasma source was developed as a millimeter-sized ion source for ion beam bioengineering. By employing a stacked arrangement of annular-shaped permanent magnets, a uniform axial magnetic flux density up to 2.8 kG was obtained. A cost effective 118 MHz RF generator was built for adjusting forward output power from 0 to 40 W. The load impedance and matching network were then analyzed. A single loop antenna and circuit matching elements were placed on a compact printed circuit board for 50 Ω impedance matching. A plasma density up to 1.1 × 10(12) cm(-3) in the 10 mm diameter tube under the magnetic flux density was achieved with 35 W applied RF power.

Development of a compact permanent magnet helicon plasma source for ion beam bioengineering

NASA Astrophysics Data System (ADS)

Kerdtongmee, P.; Srinoum, D.; Nisoa, M.

2011-10-01

A compact helicon plasma source was developed as a millimeter-sized ion source for ion beam bioengineering. By employing a stacked arrangement of annular-shaped permanent magnets, a uniform axial magnetic flux density up to 2.8 kG was obtained. A cost effective 118 MHz RF generator was built for adjusting forward output power from 0 to 40 W. The load impedance and matching network were then analyzed. A single loop antenna and circuit matching elements were placed on a compact printed circuit board for 50 Ω impedance matching. A plasma density up to 1.1 × 1012 cm-3 in the 10 mm diameter tube under the magnetic flux density was achieved with 35 W applied RF power.

Towards a Spatial Understanding of Trade-Offs in Sustainable Development: A Meso-Scale Analysis of the Nexus between Land Use, Poverty, and Environment in the Lao PDR.

PubMed

Messerli, Peter; Bader, Christoph; Hett, Cornelia; Epprecht, Michael; Heinimann, Andreas

2015-01-01

In land systems, equitably managing trade-offs between planetary boundaries and human development needs represents a grand challenge in sustainability oriented initiatives. Informing such initiatives requires knowledge about the nexus between land use, poverty, and environment. This paper presents results from Lao PDR, where we combined nationwide spatial data on land use types and the environmental state of landscapes with village-level poverty indicators. Our analysis reveals two general but contrasting trends. First, landscapes with paddy or permanent agriculture allow a greater number of people to live in less poverty but come at the price of a decrease in natural vegetation cover. Second, people practising extensive swidden agriculture and living in intact environments are often better off than people in degraded paddy or permanent agriculture. As poverty rates within different landscape types vary more than between landscape types, we cannot stipulate a land use-poverty-environment nexus. However, the distinct spatial patterns or configurations of these rates point to other important factors at play. Drawing on ethnicity as a proximate factor for endogenous development potentials and accessibility as a proximate factor for external influences, we further explore these linkages. Ethnicity is strongly related to poverty in all land use types almost independently of accessibility, implying that social distance outweighs geographic or physical distance. In turn, accessibility, almost a precondition for poverty alleviation, is mainly beneficial to ethnic majority groups and people living in paddy or permanent agriculture. These groups are able to translate improved accessibility into poverty alleviation. Our results show that the concurrence of external influences with local-highly contextual-development potentials is key to shaping outcomes of the land use-poverty-environment nexus. By addressing such leverage points, these findings help guide more effective development interventions. At the same time, they point to the need in land change science to better integrate the understanding of place-based land indicators with process-based drivers of land use change.

Towards a Spatial Understanding of Trade-Offs in Sustainable Development: A Meso-Scale Analysis of the Nexus between Land Use, Poverty, and Environment in the Lao PDR

PubMed Central

Messerli, Peter; Bader, Christoph; Hett, Cornelia; Epprecht, Michael; Heinimann, Andreas

2015-01-01

In land systems, equitably managing trade-offs between planetary boundaries and human development needs represents a grand challenge in sustainability oriented initiatives. Informing such initiatives requires knowledge about the nexus between land use, poverty, and environment. This paper presents results from Lao PDR, where we combined nationwide spatial data on land use types and the environmental state of landscapes with village-level poverty indicators. Our analysis reveals two general but contrasting trends. First, landscapes with paddy or permanent agriculture allow a greater number of people to live in less poverty but come at the price of a decrease in natural vegetation cover. Second, people practising extensive swidden agriculture and living in intact environments are often better off than people in degraded paddy or permanent agriculture. As poverty rates within different landscape types vary more than between landscape types, we cannot stipulate a land use–poverty–environment nexus. However, the distinct spatial patterns or configurations of these rates point to other important factors at play. Drawing on ethnicity as a proximate factor for endogenous development potentials and accessibility as a proximate factor for external influences, we further explore these linkages. Ethnicity is strongly related to poverty in all land use types almost independently of accessibility, implying that social distance outweighs geographic or physical distance. In turn, accessibility, almost a precondition for poverty alleviation, is mainly beneficial to ethnic majority groups and people living in paddy or permanent agriculture. These groups are able to translate improved accessibility into poverty alleviation. Our results show that the concurrence of external influences with local—highly contextual—development potentials is key to shaping outcomes of the land use–poverty–environment nexus. By addressing such leverage points, these findings help guide more effective development interventions. At the same time, they point to the need in land change science to better integrate the understanding of place-based land indicators with process-based drivers of land use change. PMID:26218646

41 CFR 302-6.305 - What factors should we consider in determining whether quarters are temporary?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Property Management Federal Travel Regulation System RELOCATION ALLOWANCES PERMANENT CHANGE OF STATION (PCS..., the employee's expressions of intent, attempts to secure a permanent dwelling, and the length of time...

41 CFR 302-6.307 - What factors should we consider in determining whether quarters are temporary?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Property Management Federal Travel Regulation System RELOCATION ALLOWANCES PERMANENT CHANGE OF STATION (PCS..., the employee's expressions of intent, attempts to secure a permanent dwelling, and the length of time...

41 CFR 302-6.307 - What factors should we consider in determining whether quarters are temporary?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Property Management Federal Travel Regulation System RELOCATION ALLOWANCES PERMANENT CHANGE OF STATION (PCS..., the employee's expressions of intent, attempts to secure a permanent dwelling, and the length of time...

41 CFR 302-6.307 - What factors should we consider in determining whether quarters are temporary?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Property Management Federal Travel Regulation System RELOCATION ALLOWANCES PERMANENT CHANGE OF STATION (PCS..., the employee's expressions of intent, attempts to secure a permanent dwelling, and the length of time...

41 CFR 302-6.305 - What factors should we consider in determining whether quarters are temporary?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Property Management Federal Travel Regulation System RELOCATION ALLOWANCES PERMANENT CHANGE OF STATION (PCS..., the employee's expressions of intent, attempts to secure a permanent dwelling, and the length of time...

Genetic parameters of legendre polynomials for first parity lactation curves.

PubMed

Pool, M H; Janss, L L; Meuwissen, T H

2000-11-01

Variance components of the covariance function coefficients in a random regression test-day model were estimated by Legendre polynomials up to a fifth order for first-parity records of Dutch dairy cows using Gibbs sampling. Two Legendre polynomials of equal order were used to model the random part of the lactation curve, one for the genetic component and one for permanent environment. Test-day records from cows registered between 1990 to 1996 and collected by regular milk recording were available. For the data set, 23,700 complete lactations were selected from 475 herds sired by 262 sires. Because the application of a random regression model is limited by computing capacity, we investigated the minimum order needed to fit the variance structure in the data sufficiently. Predictions of genetic and permanent environmental variance structures were compared with bivariate estimates on 30-d intervals. A third-order or higher polynomial modeled the shape of variance curves over DIM with sufficient accuracy for the genetic and permanent environment part. Also, the genetic correlation structure was fitted with sufficient accuracy by a third-order polynomial, but, for the permanent environmental component, a fourth order was needed. Because equal orders are suggested in the literature, a fourth-order Legendre polynomial is recommended in this study. However, a rank of three for the genetic covariance matrix and of four for permanent environment allows a simpler covariance function with a reduced number of parameters based on the eigenvalues and eigenvectors.

[Development of RF coil of permanent magnet mini-magnetic resonance imager and mouse imaging experiments].

PubMed

Hou, Shulian; Xie, Huantong; Chen, Wei; Wang, Guangxin; Zhao, Qiang; Li, Shiyu

2014-10-01

In the development of radio frequency (RF) coils for better quality of the mini-type permanent magnetic resonance imager for using in the small animal imaging, the solenoid RF coil has a special advantage for permanent magnetic system based on analyses of various types.of RF coils. However, it is not satisfied for imaging if the RF coils are directly used. By theoretical analyses of the magnetic field properties produced from the solenoid coil, the research direction was determined by careful studies to raise further the uniformity of the magnetic field coil, receiving coil sensitivity for signals and signal-to-noise ratio (SNR). The method had certain advantages and avoided some shortcomings of the other different coil types, such as, birdcage coil, saddle shaped coil and phased array coil by using the alloy materials (from our own patent). The RF coils were designed, developed and made for keeled applicable to permanent magnet-type magnetic resonance imager, multi-coil combination-type, single-channel overall RF receiving coil, and applied for a patent. Mounted on three instruments (25 mm aperture, with main magnetic field strength of 0.5 T or 1.5 T, and 50 mm aperture, with main magnetic field strength of 0.48 T), we performed experiments with mice, rats, and nude mice bearing tumors. The experimental results indicated that the RF receiving coil was fully applicable to the permanent magnet-type imaging system.

Evaluation and Comparison of Changes in Microhardness of Primary and Permanent Enamel on Exposure to Acidic Center-filled Chewing Gum: An in vitro Study

PubMed Central

Muppa, Radhika; Srinivas, NCH; Kumar, Duddu Mahesh

2014-01-01

ABSTRACT Objectives: The study is to evaluate changes in microhardness of enamel after exposure to acidic center filled chewing gum on primary and permanent teeth. Methods: Thirty primary and 30 permanent molar extracted teeth were painted with acid resistant varnish except a small window over buccal surface. Teeth were divided into four groups according to type of teeth and type of chewing gum (Center fresh and Bubbaloo) (D1, P1, D2 and P2); each tooth was exposed to whole chewing gum mashed with 5 ml of artificial saliva for five minutes at room temperature twice a day for 5 days. After the exposure, teeth were stored in deionized water and submitted for microhardness tests. Results: Paired t-test and independent sample t-test were used for statistical analysis. A significant reduction in microhardness was found between exposed and unexposed areas in all groups. There was no statistically significant difference in reduction of microhardness to chewing gums, and between primary and permanent enamel. Conclusion: There is a definite reduction in microhardness in all groups exposed to chewing gums. Both the chewing gums are equally erosive; both permanent and primary teeth were affected. How to cite this article: Mudumba VL, Muppa R, Srinivas NCH, Kumar DM. Evaluation and Comparison of Changes in Microhardness of Primary and Permanent Enamel on Exposure to Acidic Center-filled Chewing Gum: An in vitro Study. Int J Clin Pediatr Dent 2014;7(1):24-29. PMID:25206233

The Shaping of China's Postdoctoral Community: The Challenges of Equity and Quality

ERIC Educational Resources Information Center

Stith, Andrea Lynn; Liu, Li; Xu, Yibin

2011-01-01

During its brief twenty-five-year history, and under the close management of the central government, the postdoctoral training system in China has grown rapidly into a permanent element of the Chinese science and technology research system. Although designed to be attractive to elite Chinese Ph.D. talent both living abroad and in China, it turned…

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

Influence of Segmentation of Ring-Shaped NdFeB Magnets with Parallel Magnetization on Cylindrical Actuators

PubMed Central

Eckert, Paulo Roberto; Goltz, Evandro Claiton; Filho, Aly Ferreira Flores

2014-01-01

This work analyses the effects of segmentation followed by parallel magnetization of ring-shaped NdFeB permanent magnets used in slotless cylindrical linear actuators. The main purpose of the work is to evaluate the effects of that segmentation on the performance of the actuator and to present a general overview of the influence of parallel magnetization by varying the number of segments and comparing the results with ideal radially magnetized rings. The analysis is first performed by modelling mathematically the radial and circumferential components of magnetization for both radial and parallel magnetizations, followed by an analysis carried out by means of the 3D finite element method. Results obtained from the models are validated by measuring radial and tangential components of magnetic flux distribution in the air gap on a prototype which employs magnet rings with eight segments each with parallel magnetization. The axial force produced by the actuator was also measured and compared with the results obtained from numerical models. Although this analysis focused on a specific topology of cylindrical actuator, the observed effects on the topology could be extended to others in which surface-mounted permanent magnets are employed, including rotating electrical machines. PMID:25051032

Influence of segmentation of ring-shaped NdFeB magnets with parallel magnetization on cylindrical actuators.

PubMed

Eckert, Paulo Roberto; Goltz, Evandro Claiton; Flores Filho, Aly Ferreira

2014-07-21

This work analyses the effects of segmentation followed by parallel magnetization of ring-shaped NdFeB permanent magnets used in slotless cylindrical linear actuators. The main purpose of the work is to evaluate the effects of that segmentation on the performance of the actuator and to present a general overview of the influence of parallel magnetization by varying the number of segments and comparing the results with ideal radially magnetized rings. The analysis is first performed by modelling mathematically the radial and circumferential components of magnetization for both radial and parallel magnetizations, followed by an analysis carried out by means of the 3D finite element method. Results obtained from the models are validated by measuring radial and tangential components of magnetic flux distribution in the air gap on a prototype which employs magnet rings with eight segments each with parallel magnetization. The axial force produced by the actuator was also measured and compared with the results obtained from numerical models. Although this analysis focused on a specific topology of cylindrical actuator, the observed effects on the topology could be extended to others in which surface-mounted permanent magnets are employed, including rotating electrical machines.

Behaviour of smart reinforced concrete beam with super elastic shape memory alloy subjected to monotonic loading

NASA Astrophysics Data System (ADS)

Hamid, Nubailah Abd; Ibrahim, Azmi; Adnan, Azlan; Ismail, Muhammad Hussain

2018-05-01

This paper discusses the superelastic behavior of shape memory alloy, NiTi when used as reinforcement in concrete beams. The ability of NiTi to recover and reduce permanent deformations of concrete beams was investigated. Small-scale concrete beams, with NiTi reinforcement were experimentally investigated under monotonic loads. The behaviour of simply supported reinforced concrete (RC) beams hybrid with NiTi rebars and the control beam subject to monotonic loads were experimentally investigated. This paper is to highlight the ability of the SMA bars to recover and reduce permanent deformations of concrete flexural members. The size of the control beam is 125 mm × 270 mm × 1000 mm with 3 numbers of 12 mm diameter bars as main reinforcement for compression and 3 numbers of 12 mm bars as tension or hanger bars while 6 mm diameter at 100 mm c/c used as shear reinforcement bars for control beam respectively. While, the minimal provision of 200mm using the 12.7mm of superelastic Shape Memory Alloys were employed to replace the steel rebar at the critical region of the beam. In conclusion, the contribution of the SMA bar in combination with high-strength steel to the conventional reinforcement showed that the SMA beam has exhibited an improve performance in term of better crack recovery and deformation. Therefore the usage of hybrid NiTi with the steel can substantially diminish the risk of the earthquake and also can reduce the associated cost aftermath.

Reconfigurable Photonic Crystals Enabled by Multistimuli-Responsive Shape Memory Polymers Possessing Room Temperature Shape Processability.

PubMed

Fang, Yin; Leo, Sin-Yen; Ni, Yongliang; Wang, Junyu; Wang, Bingchen; Yu, Long; Dong, Zhe; Dai, Yuqiong; Basile, Vito; Taylor, Curtis; Jiang, Peng

2017-02-15

Traditional shape memory polymers (SMPs) are mostly thermoresponsive, and their applications in nano-optics are hindered by heat-demanding programming and recovery processes. By integrating a polyurethane-based shape memory copolymer with templating nanofabrication, reconfigurable/rewritable macroporous photonic crystals have been demonstrated. This SMP coupled with the unique macroporous structure enables unusual all-room-temperature shape memory cycles. "Cold" programming involving microscopic order-disorder transitions of the templated macropores is achieved by mechanically deforming the macroporous SMP membranes. The rapid recovery of the permanent, highly ordered photonic crystal structure from the temporary, disordered configuration can be triggered by multiple stimuli including a large variety of vapors and solvents, heat, and microwave radiation. Importantly, the striking chromogenic effects associated with these athermal and thermal processes render a sensitive and noninvasive optical methodology for quantitatively characterizing the intriguing nanoscopic shape memory effects. Some critical parameters/mechanisms that could significantly affect the final performance of SMP-based reconfigurable photonic crystals including strain recovery ratio, dynamics and reversibility of shape recovery, as well as capillary condensation of vapors in macropores, which play a crucial role in vapor-triggered recovery, can be evaluated using this new optical technology.

Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho–ROCK–myosin II signaling pathway to ensure formation of a basal constriction

PubMed Central

Holz, Oliver; Apel, David; Steinmetz, Patrick; Lange, Ellen; Hopfenmüller, Simon; Ohler, Kerstin; Sudhop, Stefanie

2017-01-01

Background: Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto‐ and endodermal epithelia is unknown. Results: Histological sections and staining of F‐actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F‐actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Conclusions: Our data suggest an essential role of FGFR and a Rho‐ROCK‐myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502–516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists PMID:28411398

Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho-ROCK-myosin II signaling pathway to ensure formation of a basal constriction.

PubMed

Holz, Oliver; Apel, David; Steinmetz, Patrick; Lange, Ellen; Hopfenmüller, Simon; Ohler, Kerstin; Sudhop, Stefanie; Hassel, Monika

2017-07-01

Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto- and endodermal epithelia is unknown. Histological sections and staining of F-actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F-actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Our data suggest an essential role of FGFR and a Rho-ROCK-myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502-516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Technological and economical analysis of salient pole and permanent magnet synchronous machines designed for wind turbines

NASA Astrophysics Data System (ADS)

Gündoğdu, Tayfun; Kömürgöz, Güven

2012-08-01

Chinese export restrictions already reduced the planning reliability for investments in permanent magnet wind turbines. Today the production of permanent magnets consumes the largest proportion of rare earth elements, with 40% of the rare earth-based magnets used for generators and other electrical machines. The cost and availability of NdFeB magnets will likely determine the production rate of permanent magnet generators. The high volatility of rare earth metals makes it very difficult to quote a price. Prices may also vary from supplier to supplier to an extent of up to 50% for the same size, shape and quantity with a minor difference in quality. The paper presents the analysis and the comparison of salient pole with field winding and of peripheral winding synchronous electrical machines, presenting important advantages. A neodymium alloy magnet rotor structure has been considered and compared to the salient rotor case. The Salient Pole Synchronous Machine and the Permanent Magnet Synchronous Machine were designed so that the plate values remain constant. The Eddy current effect on the windings is taken into account during the design, and the efficiency, output power and the air-gap flux density obtained after the simulation were compared. The analysis results clearly indicate that Salient Pole Synchronous Machine designs would be attractive to wind power companies. Furthermore, the importance of the design of electrical machines and the determination of criteria are emphasized. This paper will be a helpful resource in terms of examination and comparison of the basic structure and magnetic features of the Salient Pole Synchronous Machine and Permanent Magnet Synchronous Machine. Furthermore, an economic analysis of the designed machines was conducted.

Comparison of the microhardness of primary and permanent teeth after immersion in two types of carbonated beverages.

PubMed

Haghgou, Hamid R; Haghgoo, Roza; Asdollah, Fatemah Molla

2016-01-01

The consumption of carbonated beverages is one of the etiological factors that cause dental erosion. The purpose of this research was to compare changes in the microhardness of permanent and primary teeth after immersion in two types of carbonated beverages. This investigation was done on 30 healthy permanent molars and 30 healthy primary canines. Each group of primary and permanent teeth was subdivided into three groups of 10 teeth. The teeth was immersed in 40 ml of each of the three beverages for 5 min. One subgroup was immersed in water (as a control). The next was immersed in Lemon Delster and the last subgroup was immersed in Coca-Cola. The microhardness of enamel was measured using the Vickers method before and after immersion. Finally, the data was analyzed by paired t-test, one-way analysis of variance, and t-test. Microhardness reduction in the primary teeth was significant in both the Lemon Delster and Coca-Cola groups (P < 0.05). This reduction was also statistically significant in the permanent teeth (P < 0.05). A comparison of the enamel changes in the primary teeth with permanent teeth after immersion in both beverages showed a greater microhardness reduction in the primary teeth in both the experimental groups. Coca-Cola and Lemon Delster caused a significant reduction of microhardness in tooth enamel. This reduction was greater in primary teeth than in permanent teeth, and was also greater after immersion in Coca-Cola than after immersion in Lemon Delster.

Reversibility and criticality in amorphous solids

DOE PAGES

Regev, Ido; Weber, John; Reichhardt, Charles; ...

2015-11-13

The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a ‘front depinning’ transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaoticmore » behaviour and why chaotic motion is not possible in pinned systems. As a result, these findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched.« less

Camel milk, amoxicillin, and a prayer: medical pluralism and medical humanitarian aid in the Somali Region of Ethiopia.

PubMed

Carruth, Lauren

2014-11-01

This paper details how exposure to new clinics, diagnostic technologies, and pharmaceuticals during humanitarian relief operations in the Somali Region of Ethiopia shaped local pluralistic health systems and altered the ways in which residents subsequently conceived of and treated illness and disease. Despite rising demand for pharmaceuticals and diagnostic technologies among Somalis in Ethiopia, local ethnophysiologies continued to draw upon popular ideas about humoral flows, divine action, and spirit possession. Demands for therapeutic camel milk, Qur'anic spiritual healing, herbal remedies, and other historically popular therapies persisted, but were shaped by concurrent demands for and understandings of diagnostic biotechnologies and pharmaceutical medications. The reverse was also true: contemporary understandings and uses of non-biomedical healing modalities among Somalis shaped evaluations of clinical care, including healthcare during humanitarian responses. To illustrate these phenomena, based on ethnographic research in eastern Ethiopia between 2007 and 2009, this paper explores three topics vital to Somalis' pluralistic healthcare systems: camel milk and the management of digestive bile; women's experiences and clinical presentations with pain and disorder in their reproductive systems; and the rising popularity of high-tech diagnostic tests. I conclude that medical humanitarian aid never happens in a vacuum or among truly treatment-naïve populations. Instead, aid unfolds within ever-changing and pluralistic health cultures, and it permanently alters and is altered by the frames within which people evaluate and make future decisions about healthcare. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radially and azimuthally polarized laser induced shape transformation of embedded metallic nanoparticles in glass.

PubMed

Tyrk, Mateusz A; Zolotovskaya, Svetlana A; Gillespie, W Allan; Abdolvand, Amin

2015-09-07

Radially and azimuthally polarized picosecond (~10 ps) pulsed laser irradiation at 532 nm wavelength led to the permanent reshaping of spherical silver nanoparticles (~30 - 40 nm in diameter) embedded in a thin layer of soda-lime glass. The observed peculiar shape modifications consist of a number of different orientations of nano-ellipsoids in the cross-section of each written line by laser. A Second Harmonic Generation cross-sectional scan method from silver nanoparticles in transmission geometry was adopted for characterization of the samples after laser modification. The presented approach may lead to sophisticated marking of information in metal-glass nanocomposites.

Frozen section pathology for decision making in parotid surgery.

PubMed

Olsen, Kerry D; Moore, Eric J; Lewis, Jean E

2013-12-01

For parotid lesions, the high accuracy and utility of intraoperative frozen section (FS) pathology, compared with permanent section pathology, facilitates intraoperative decision making about the extent of surgery required. To demonstrate the accuracy and utility of FS pathology of parotid lesions as one factor in intraoperative decision making. Retrospective review of patients undergoing parotidectomy at a tertiary care center. Evaluation of the accuracy of FS pathology for parotid surgery by comparing FS pathology results with those of permanent section. Documented changes from FS to permanent section in 1339 parotidectomy pathology reports conducted from January 1, 2000, through December 31, 2009, included 693 benign and 268 primary and metastatic malignant tumors. Changes in diagnosis were found from benign to malignant (n = 11) and malignant to benign (n = 2). Sensitivity and specificity of a malignant diagnosis were 98.5% and 99.0%, respectively. Other changes were for lymphoma vs inflammation or lymphoma typing (n = 89) and for confirmation of or change in tumor type for benign (n = 36) or malignant (n = 69) tumors. No case changed from low- to high-grade malignant tumor. Only 4 cases that changed from FS to permanent section would have affected intraoperative decision making. Three patients underwent additional surgery 2 to 3 weeks later. Overall, only 1 patient was overtreated (lymphoma initially deemed carcinoma). Frozen section pathology for parotid lesions has high accuracy and utility in intraoperative decision making, facilitating timely complete procedures.

Modified cuspal relationships of mandibular molar teeth in children with Down's syndrome

PubMed Central

PERETZ, BENJAMIN; SHAPIRA, JOSEPH; FARBSTEIN, HANNA; ARIELI, ELIAHU; SMITH, PATRICIA

1998-01-01

A total of 50 permanent mandibular 1st molars of 26 children with Down's syndrome (DS) were examined from dental casts and 59 permanent mandibular 1st molars of normal children were examined from 33 individuals. The following measurements were performed on both right and left molars (teeth 46 and 36 respectively): (a) the intercusp distances (mb-db, mb-d, mb-dl, db-ml, db-d, db-dl, db-ml, d-dl, d-ml, dl-ml); (b) the db-mb-ml, mb-db-ml, mb-ml-db, d-mb-dl, mb-d-dl, mb-dl-d angles; (c) the area of the pentagon formed by connecting the cusp tips. All intercusp distances were significantly smaller in the DS group. Stepwise logistic regression, applied to all the intercusp distances, was used to design a multivariate probability model for DS and normals. A model based on 2 distances only, mb-dl and mb-db, proved sufficient to discriminate between the teeth of DS and the normal population. The model for tooth 36 for example was as follows: formula here A similar model for tooth 46 was also created, as well as a model which incorporated both teeth. With respect to the angles, significant differences between DS and normals were found in 3 out of the 6 angles which were measured: the d-mb-dl angle was smaller than in normals, the mb-d-dl angle was higher, and the mb-dl-d angle was smaller. The dl cusp was located closer to the centre of the tooth. The change in size occurs at an early stage, while the change in shape occurs in a later stage of tooth formation in the DS population. PMID:10029186

Characterization of Transformation-Induced Defects in Nickel Titanium Shape Memory Alloys

NASA Astrophysics Data System (ADS)

Bowers, Matthew L.

Shape memory alloys have remarkable strain recovery properties that make them ideal candidates for many applications that include devices in the automotive, aerospace, medical, and MEMS industries. Although these materials are widely used today, their performance is hindered by poor dimensional stability resulting from cyclic degradation of the martensitic transformation behavior. This functional fatigue results in decreased work output and cyclic accumulation of permanent strain. To date, few studies have taken a fundamental approach to investigating the interaction between plasticity and martensite growth and propagation, which is vitally important to mitigating functional fatigue in future alloy development. The current work focuses on understanding the interplay of these deformation mechanisms in NiTi-based shape memory alloys under a variety of different thermomechanical test conditions. Micron-scale compression testing of NiTi shape memory alloy single crystals is undertaken in an effort to probe the mechanism of austenite dislocation generation. Mechanical testing is paired with post mortem defect analysis via diffraction contrast scanning transmission electron microscopy (STEM). Accompanied by micromechanics-based modeling of local stresses surrounding a martensite plate, these results demonstrate that the previously existing martensite and resulting austenite dislocation substructure are intimately related. A mechanism of transformation-induced dislocation generation is described in detail. A study of pure and load-biased thermal cycling of bulk polycrystalline NiTi is done for comparison of the transformation behavior and resultant defects to the stress-induced case. Post mortem and in situ STEM characterization demonstrate unique defect configurations in this test mode and STEM-based orientation mapping reveals local crystal rotation with increasing thermal cycles. Changes in both martensite and austenite microstructures are explored. The results for several different thermomechanical histories are discussed and a new mechanism of austenite grain refinement is proposed with support from ab initio calculations and crystallographic theory.

A torsional MRE joint for a C-shaped robotic leg

NASA Astrophysics Data System (ADS)

Christie, M. D.; Sun, S. S.; Ning, D. H.; Du, H.; Zhang, S. W.; Li, W. H.

2017-01-01

Serving to improve stability and energy efficiency during locomotion, in nature, animals modulate their leg stiffness to adapt to their terrain. Now incorporated into many locomotive robot designs, such compliance control can enable disturbance rejection and improved transition between changing ground conditions. This paper presents a novel design of a variable stiffness leg utilizing a magnetorheological elastomer joint in a literal rolling spring loaded inverted pendulum (R-SLIP) morphology. Through the semi-active control of this hybrid permanent-magnet and coil design, variable stiffness is realized, offering a design which is capable of both softening and stiffening in an adaptive sort of way, with a maximum stiffness change of 48.0%. Experimental characterization first serves to assess the stiffness variation capacity of the torsional joint, and through later comparison with force testing of the leg, the linear stiffness is characterized with the R-SLIP-like behavior of the leg being demonstrated. Through the force relationships applied, a generalized relationship for determining linear stiffness based on joint rotation angle is also proposed, further aiding experimental validation.

Bone development in laboratory mammals used in developmental toxicity studies.

PubMed

DeSesso, John M; Scialli, Anthony R

2018-06-19

Evaluation of the skeleton in laboratory animals is a standard component of developmental toxicology testing. Standard methods of performing the evaluation have been established, and modification of the evaluation using imaging technologies is under development. The embryology of the rodent, rabbit, and primate skeleton has been characterized in detail and summarized herein. The rich literature on variations and malformations in skeletal development that can occur in the offspring of normal animals and animals exposed to test articles in toxicology studies is reviewed. These perturbations of skeletal development include ossification delays, alterations in number, shape, and size of ossification centers, and alterations in numbers of ribs and vertebrae. Because the skeleton is undergoing developmental changes at the time fetuses are evaluated in most study designs, transient delays in development can produce apparent findings of abnormal skeletal structure. The determination of whether a finding represents a permanent change in embryo development with adverse consequences for the organism is important in study interpretation. Knowledge of embryological processes and schedules can assist in interpretation of skeletal findings. © 2018 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc.

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.

RCT of a Mentoring and Skills Group Program: Placement and Permanency Outcomes for Foster Youth

PubMed Central

Culhane, Sara E.; Garrido, Edward; Knudtson, Michael D.

2012-01-01

OBJECTIVE: To examine the impact of a mentoring and skills group intervention for preadolescent children in foster care on placement stability and permanence at 1-year postintervention. METHODS: A randomized controlled trial was conducted with 9- to 11-year-old children who were maltreated and placed in foster care (n = 54 control; n = 56 intervention). State child welfare records provided information on number of placement changes, placement in residential treatment, and case closure (ie, permanency). Rates of adoption and reunification were also examined. Analysis was by intention to treat. RESULTS: After controlling for baseline functioning and preintervention placement history, intervention youth were 71% less likely to be placed in residential treatment (odds ratio [OR] = 0.29, 95% confidence interval [CI] 0.09–0.98). There were no significant treatment differences in predicting placement changes or permanency for the total sample. Among a subsample of children living in nonrelative foster care at baseline, intervention youth had 44% fewer placement changes (incidence ratio = 0.56, 95% CI 0.34–0.93), were 82% less likely to be placed in a residential treatment center (OR = 0.18, 95% CI 0.03–0.96), and were 5 times more likely to have attained permanency at 1 year postintervention (OR = 5.14, 95% CI 1.55–17.07). More intervention youth had reunified 1-year postintervention [χ2(1, N = 78) = 3.99; P < .05], and the pattern of findings suggested that intervention youth had higher rates of adoption. A significant interaction [χ2(1, N = 110) = 5.43; P = .02] demonstrated that the intervention attenuated the impact of baseline behavior problems on placement changes. CONCLUSIONS: The findings suggest that participation in a 9-month mentoring and skills group intervention leads to greater placement stability and permanence, especially for children in nonrelative foster care. PMID:22689870

Avoiding treatment bias of REDD+ monitoring by sampling with partial replacement.

PubMed

Köhl, Michael; Scott, Charles T; Lister, Andrew J; Demon, Inez; Plugge, Daniel

2015-12-01

Implementing REDD+ renders the development of a measurement, reporting and verification (MRV) system necessary to monitor carbon stock changes. MRV systems generally apply a combination of remote sensing techniques and in-situ field assessments. In-situ assessments can be based on 1) permanent plots, which are assessed on all successive occasions, 2) temporary plots, which are assessed only once, and 3) a combination of both. The current study focuses on in-situ assessments and addresses the effect of treatment bias, which is introduced by managing permanent sampling plots differently than the surrounding forests. Temporary plots are not subject to treatment bias, but are associated with large sampling errors and low cost-efficiency. Sampling with partial replacement (SPR) utilizes both permanent and temporary plots. We apply a scenario analysis with different intensities of deforestation and forest degradation to show that SPR combines cost-efficiency with the handling of treatment bias. Without treatment bias permanent plots generally provide lower sampling errors for change estimates than SPR and temporary plots, but do not provide reliable estimates, if treatment bias occurs, SPR allows for change estimates that are comparable to those provided by permanent plots, offers the flexibility to adjust sample sizes in the course of time, and allows to compare data on permanent versus temporary plots for detecting treatment bias. Equivalence of biomass or carbon stock estimates between permanent and temporary plots serves as an indication for the absence of treatment bias while differences suggest that there is evidence for treatment bias. SPR is a flexible tool for estimating emission factors from successive measurements. It does not entirely depend on sample plots that are installed at the first occasion but allows for the adjustment of sample sizes and placement of new plots at any occasion. This ensures that in-situ samples provide representative estimates over time. SPR offers the possibility to increase sampling intensity in areas with high degradation intensities or to establish new plots in areas where permanent plots are lost due to deforestation. SPR is also an ideal approach to mitigate concerns about treatment bias.

Permanent field plot methodology and equipment

Treesearch

Thomas G. Cole

1993-01-01

Long-term research into the composition, phenology, yield, and growth rates of agroforests can be accomplished with the use of permanent field plots. The periodic remeasurement of these plots provides researchers a quantitative measure of what changes occur over time in indigenous agroforestry systems.

Spectral and spatial shaping of a laser-produced ion beam for radiation-biology experiments

NASA Astrophysics Data System (ADS)

Pommarel, L.; Vauzour, B.; Mégnin-Chanet, F.; Bayart, E.; Delmas, O.; Goudjil, F.; Nauraye, C.; Letellier, V.; Pouzoulet, F.; Schillaci, F.; Romano, F.; Scuderi, V.; Cirrone, G. A. P.; Deutsch, E.; Flacco, A.; Malka, V.

2017-03-01

The study of radiation biology on laser-based accelerators is most interesting due to the unique irradiation conditions they can produce, in terms of peak current and duration of the irradiation. In this paper we present the implementation of a beam transport system to transport and shape the proton beam generated by laser-target interaction for in vitro irradiation of biological samples. A set of four permanent magnet quadrupoles is used to transport and focus the beam, efficiently shaping the spectrum and providing a large and relatively uniform irradiation surface. Real time, absolutely calibrated, dosimetry is installed on the beam line, to enable shot-to-shot control of dose deposition in the irradiated volume. Preliminary results of cell sample irradiation are presented to validate the robustness of the full system.

Design and analysis of new fault-tolerant permanent magnet motors for four-wheel-driving electric vehicles

NASA Astrophysics Data System (ADS)

Liu, Guohai; Gong, Wensheng; Chen, Qian; Jian, Linni; Shen, Yue; Zhao, Wenxiang

2012-04-01

In this paper, a novel in-wheel permanent-magnet (PM) motor for four-wheel-driving electrical vehicles is proposed. It adopts an outer-rotor topology, which can help generate a large drive torque, in order to achieve prominent dynamic performance of the vehicle. Moreover, by adopting single-layer concentrated-windings, fault-tolerant teeth, and the optimal combination of slot and pole numbers, the proposed motor inherently offers negligible electromagnetic coupling between different phase windings, hence, it possesses a fault-tolerant characteristic. Meanwhile, the phase back electromotive force waveforms can be designed to be sinusoidal by employing PMs with a trapezoidal shape, eccentric armature teeth, and unequal tooth widths. The electromagnetic performance is comprehensively investigated and the optimal design is conducted by using the finite-element method.

Pore-scale imaging of capillary trapped supercritical CO2 as controlled by water-wet vs. CO2-wet media and grain shapes

NASA Astrophysics Data System (ADS)

Chaudhary, K.; Cardenas, M.; Wolfe, W. W.; Maisano, J. A.; Ketcham, R. A.; Bennett, P.

2013-12-01

The capillary trapping of supercritical CO2 (s-CO2) is postulated to comprise up to 90% of permanently trapped CO2 injected during geologic sequestration. Successive s-CO2/brine flooding experiments under reservoir conditions showed that water-wet rounded beads trapped 15% of injected s-CO2 both as clusters and as individual ganglia, whereas CO2¬-wet beads trapped only 2% of the injected s-CO2 as minute pockets in pore constrictions. Angular water-wet grains trapped 20% of the CO2 but flow was affected by preferential flow. Thus, capillary trapping is a viable mechanism for the permanent CO2 storage, but its success is constrained by the media wettability.

Middle mesial canal of the permanent mandibular first molars: an anatomical challenge directly related to the outcome of endodontic treatment.

PubMed

Perlea, Paula; Nistor, Cristina Coralia; Imre, Marina; Gheorghiu, Irina Maria; Iliescu, Alexandru Andrei

2017-01-01

To effectively clean and shape the mandibular permanent first molars it is mandatory to understand in detail their complex internal anatomy. The middle mesial canal is an additional canal located between the usual mesiobuccal and mesiolingual canals in the mesial root of mandibular first molars. The incidence of the middle mesial canal, its relationship with main canals of the mesial root and the possibility for it to be negotiated is an important practical issue in endodontics. To identify the presence of this canal is mandatory. Accordingly, a modified endodontic access, the use of the operating microscope and periapical radiographs in two different horizontal projections are indicated to enhance the long-term favorable outcome of the endodontic treatment.

Navy Personnel Survey (NPS) 1990 Survey Report, Statistical Tables. Volume 1. Enlisted Personnel.

DTIC Science & Technology

1991-08-01

Respondents were asked to provide demographic data and to indicate their attitudes or opinions on rotation/ permanent change of station (PCS) moves...and measured military members attitudes and opinions in various areas, including rotation/permanent change of station moves, recruiting duty, pay and...about: the 0rganizaional Clmate Use the spac below to make any comments you wish about the organizational climate, including EQ is- and sexual3 harassment

Prenatal Maternal Stress Predicts Methylation of Genes Regulating the Hypothalamic-Pituitary-Adrenocortical System in Mothers and Newborns in the Democratic Republic of Congo

ERIC Educational Resources Information Center

Kertes, Darlene A.; Kamin, Hayley S.; Hughes, David A.; Rodney, Nicole C.; Bhatt, Samarth; Mulligan, Connie J.

2016-01-01

Exposure to stress early in life permanently shapes activity of the hypothalamic-pituitary-adrenocortical (HPA) axis and the brain. Prenatally, glucocorticoids pass through the placenta to the fetus with postnatal impacts on brain development, birth weight (BW), and HPA axis functioning. Little is known about the biological mechanisms by which…

Re-Shaping the Faculty: Emergence and Development of "Permanent-Contingent" Roles through the Lens of Cultural-Historical Activity Theory

ERIC Educational Resources Information Center

Tkachenko, Oleksandr; Louis, Karen Seashore

2017-01-01

This study retrospectively examines the emergence and development of a new class of full-time non-tenure track employees in a large land grant research university in the U.S., which created the employment category in 1980. We employ cultural-historical activity theory (CHAT) to explore how this class of employees became institutionalized within…

Geometric Folding Algorithms: Bridging Theory to Practice

DTIC Science & Technology

2009-11-03

orthogonal polyhedron can be folded from a single, universal crease pattern (box pleating). II. ORIGAMI DESIGN a.) Developed mathematical theory for what...happens in paper between creases, in particular for the case of circular creases. b.) Circular crease origami on permanent exhibition at MoMA in New...Developing mathematical theory of Robert Lang’s TreeMaker framework for efficiently folding tree-shaped origami bases.

Nearshore Pipeline Installation Methods.

DTIC Science & Technology

1981-08-01

inches b) Pipe, materials of construction: fully rigid, semi-rigid, flexible c) Pipeline length, maximum 2 miles d) Pipeline design life , minimum 15...common to their operations. Permanent facilities are specified in the Statement of Work. There- fore, a minimum design life of 15 years is chosen, which...makes the pipe leakproof and resists corrosion and abrasion. 5) Interlocked Z-shaped steel or stainless steel carcass - resists internal and external

Reduction of Cogging Torque in Dual Rotor Permanent Magnet Generator for Direct Coupled Wind Energy Systems

PubMed Central

Paulsamy, Sivachandran

2014-01-01

In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions. PMID:25202746

Reduction of cogging torque in dual rotor permanent magnet generator for direct coupled wind energy systems.

PubMed

Paulsamy, Sivachandran

2014-01-01

In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions.

Comparative study of dental anomalies assessed with panoramic radiographs of Down syndrome and non-Down syndrome patients.

PubMed

Mayoral-Trias, M A; Llopis-Perez, J; Puigdollers Pérez, A

2016-03-01

The aim of this study was to compare the prevalence of dental anomalies from panoramic radiographs of age-matched individuals with and without Down Syndrome (DS). This is a retrospective cross-sectional study. A group of 41 patients (19 female and 22 male) with Down Syndrome (DS), mean age 10.6 ± 1.4 and a control group of 42 non- DS patients (26 female and 16 male), mean age 11.1 ± 1.3 were studied. This study examined the medical history and a panoramic radiograph of each patient. The dental anomalies studied were agenesis of permanent teeth (except third molars), size and shape maxillary lateral anomalies and maxillary canine eruption path anomalies. The groups were compared using Mann-Whitney and Wilcoxon non-parametric tests (p<0.05). Rho Spearman correlation coefficient was applied for associations. Results Agenesis of one permanent tooth was found in 73.17% of DS subjects and two or more permanent teeth in more than 50% (p<0.001). Maxillary lateral incisor was the most frequently absent tooth followed by mandibular second premolar, mandibular lateral incisor, maxillary second premolar and mandibular central incisor. No significant differences were detected between maxilla and mandible on either side. No differences in gender were observed. Significant differences were found for size and shape anomalies of maxillary lateral incisors, as well as for canine eruption anomalies (p<0.05). No gender differences were observed for either variable. No association was found between these two variables in the DS group. More dental anomalies were present in the DS group than in the control group, which implied that DS patients need periodical dental and orthodontic supervision so as to prevent or control subsequent oral problems.

27 CFR 18.38 - Permanent discontinuance.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Permanent discontinuance. 18.38 Section 18.38 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Qualification Changes...

27 CFR 18.38 - Permanent discontinuance.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Permanent discontinuance. 18.38 Section 18.38 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Qualification Changes...

27 CFR 18.38 - Permanent discontinuance.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Permanent discontinuance. 18.38 Section 18.38 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Qualification Changes...

27 CFR 18.38 - Permanent discontinuance.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Permanent discontinuance. 18.38 Section 18.38 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Qualification Changes...

Variation of mechanical properties due to hygrothermal ageing and permanent changes upon redrying in clay/epoxy nanocomposites

NASA Astrophysics Data System (ADS)

Hamim, Salah Uddin Ahmed

2011-12-01

Epoxy polymers are an important class of material for use in various applications. Due to their hydrophilic nature, epoxy resins tend to absorb moisture. Absorption of moisture degrades the functional, structural and mechanical properties. For polymers, moisture absorption can lead to both reversible and irreversible changes. In this study, the combined effect of moisture and elevated temperature on the mechanical properties of Epon 862 and its nanocomposites were investigated. The extent of permanent damage on fracture toughness and flexural properties of epoxy, due to the aggressive degradation provided by hygrothermal ageing, was determined by drying the epoxy and their clay/epoxy nanocomposites after moisture absorption. From the investigation it was found out that, clay can help in reducing the negative effect of hygrothermal ageing. Significant permanent damage was observed for fracture toughness and modulus, while the extent of permanent damage was less significant for flexural strength. Failure mechanism of this nanocomposites were studied by using Scanning Electron Microscopy (SEM).

Comparison of the microhardness of primary and permanent teeth after immersion in two types of carbonated beverages

PubMed Central

Haghgou, Hamid R.; Haghgoo, Roza; Asdollah, Fatemah Molla

2016-01-01

Objectives: The consumption of carbonated beverages is one of the etiological factors that cause dental erosion. The purpose of this research was to compare changes in the microhardness of permanent and primary teeth after immersion in two types of carbonated beverages. Materials and Methods: This investigation was done on 30 healthy permanent molars and 30 healthy primary canines. Each group of primary and permanent teeth was subdivided into three groups of 10 teeth. The teeth was immersed in 40 ml of each of the three beverages for 5 min. One subgroup was immersed in water (as a control). The next was immersed in Lemon Delster and the last subgroup was immersed in Coca-Cola. The microhardness of enamel was measured using the Vickers method before and after immersion. Finally, the data was analyzed by paired t-test, one-way analysis of variance, and t-test. Results: Microhardness reduction in the primary teeth was significant in both the Lemon Delster and Coca-Cola groups (P < 0.05). This reduction was also statistically significant in the permanent teeth (P < 0.05). A comparison of the enamel changes in the primary teeth with permanent teeth after immersion in both beverages showed a greater microhardness reduction in the primary teeth in both the experimental groups. Conclusions: Coca-Cola and Lemon Delster caused a significant reduction of microhardness in tooth enamel. This reduction was greater in primary teeth than in permanent teeth, and was also greater after immersion in Coca-Cola than after immersion in Lemon Delster. PMID:27583223

Silicone Membranes to Inhibit Water Uptake into Thermoset Polyurethane Shape-Memory Polymer Conductive Composites

PubMed Central

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A.; Maitland, Duncan J.

2014-01-01

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (Tg) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this study, a silicone membrane was used to inhibit water uptake into a thermoset SMP composite containing conductive filler. Thermoset polyurethane (PU) SMPs were loaded with either 5 wt% carbon black (CB) or 5 wt% carbon nanotubes (CNT) and subsequently coated with either an Al2O3- or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37 °C) and subsequent Tg depression versus uncoated composites. In turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37 °C. PMID:25663711

Silicone Membranes to Inhibit Water Uptake into Thermoset Polyurethane Shape-Memory Polymer Conductive Composites.

PubMed

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A; Maitland, Duncan J

2015-01-05

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature ( T g ) resulting in shape recovery in vivo . While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo . In this study, a silicone membrane was used to inhibit water uptake into a thermoset SMP composite containing conductive filler. Thermoset polyurethane (PU) SMPs were loaded with either 5 wt% carbon black (CB) or 5 wt% carbon nanotubes (CNT) and subsequently coated with either an Al 2 O 3 - or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37 °C) and subsequent T g depression versus uncoated composites. In turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37 °C.

Silicone membranes to inhibit water uptake into thermoset polyurethane shape-memory polymer conductive composites

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

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A.

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (T g) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this paper, a silicone membrane was used to inhibit water uptake into a thermoset SMPmore » composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al 2O 3- or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37°C) and subsequent T g depression versus uncoated composites. Finally, in turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C.« less

Silicone membranes to inhibit water uptake into thermoset polyurethane shape-memory polymer conductive composites

DOE PAGES

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A.; ...

2014-07-24

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (T g) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this paper, a silicone membrane was used to inhibit water uptake into a thermoset SMPmore » composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al 2O 3- or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37°C) and subsequent T g depression versus uncoated composites. Finally, in turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C.« less

Shape Memory Composites Based on Electrospun Poly(vinyl alcohol) Fibers and a Thermoplastic Polyether Block Amide Elastomer.

PubMed

Shirole, Anuja; Sapkota, Janak; Foster, E Johan; Weder, Christoph

2016-03-01

The present study aimed at developing new thermally responsive shape-memory composites, that were fabricated by compacting mats of electrospun poly(vinyl alcohol) (PVA) fibers and sheets of a thermoplastic polyether block amide elastomer (PEBA). This design was based on the expectation that the combination of the rubber elasticity of the PEBA matrix and the mechanical switching exploitable through the reversible glass transition temperature (Tg) of the PVA filler could be combined to create materials that display shape memory characteristics as an emergent effect. Dynamic mechanical analyses (DMA) show that, upon introduction of 10-20% w/w PVA fibers, the room-temperature storage modulus (E') increased by a factor of 4-5 in comparison to the neat PEBA, and they reveal a stepwise reduction of E' around the Tg of PVA (85 °C). This transition could indeed be utilized to fix a temporary shape and recover the permanent shape. At low strain, the fixity was 66 ± 14% and the recovery was 98 ± 2%. Overall, the data validate a simple and practical strategy for the fabrication of shape memory composites that involves a melt compaction process and employs two commercially available polymers.

Suigetsumonas clinomigrationis gen. et sp. nov., a Novel Facultative Anaerobic Nanoflagellate Isolated from the Meromictic Lake Suigetsu, Japan.

PubMed

Okamura, Takahiko; Kondo, Ryuji

2015-09-01

A novel facultative anaerobic bacterivorous nanoflagellate was isolated from the water just below the permanent oxic-anoxic interface of the meromictic Lake Suigetsu, Japan. We characterized the isolate using light and transmission electron microscopy and molecular phylogenetic analyses inferred from 18S rDNA sequences. The phylogenetic analyses showed that the isolate belonged to class Placididea (stramenopiles). The isolate showed key ultrastructural features of the Placididea, such as flagellar hairs with two unequal terminal filaments, microtubular root 2 changing in shape from an arced to an acute-angled shape, and a lack of an x-fiber in root 2. However, the isolate had a single helix in the flagellar transition region, which is a double helix in the two known placidid nanoflagellates Placidia cafeteriopsis and Wobblia lunata. Moreover, the isolate had different intracellular features compared with these two genera, such as the arrangement of basal bodies, the components of the flagellar apparatus, the number of mitochondria, and the absence (or presence) of paranuclear bodies. The 18S rDNA sequence was also phylogenetically distant from the clades of the known Placididae W. lunata and P. cafeteriopsis. Consequently, the newly isolated nanoflagellate was described as Suigetsumonas clinomigrationis gen. et sp. nov. Copyright © 2015 Elsevier GmbH. All rights reserved.

Internal Tooth Structure and Burial Practices: Insights into the Neolithic Necropolis of Gurgy (France, 5100-4000 cal. BC).

PubMed

Le Luyer, Mona; Coquerelle, Michael; Rottier, Stéphane; Bayle, Priscilla

2016-01-01

Variations in the dental crown form are widely studied to interpret evolutionary changes in primates as well as to assess affinities among human archeological populations. Compared to external metrics of dental crown size and shape, variables including the internal structures such as enamel thickness, tissue proportions, and the three-dimensional shape of enamel-dentin junction (EDJ), have been described as powerful measurements to study taxonomy, phylogenetic relationships, dietary, and/or developmental patterns. In addition to providing good estimate of phenotypic distances within/across archeological samples, these internal tooth variables may help to understand phylogenetic, functional, and developmental underlying causes of variation. In this study, a high resolution microtomographic-based record of upper permanent second molars from 20 Neolithic individuals of the necropolis of Gurgy (France) was applied to evaluate the intrasite phenotypic variation in crown tissue proportions, thickness and distribution of enamel, and EDJ shape. The study aims to compare interindividual dental variations with burial practices and chronocultural parameters, and suggest underlying causes of these dental variations. From the non-invasive characterization of internal tooth structure, differences have been found between individuals buried in pits with alcove and those buried in pits with container and pits with wattling. Additionally, individuals from early and recent phases of the necropolis have been distinguished from those of the principal phase from their crown tissue proportions and EDJ shape. The results suggest that the internal tooth structure may be a reliable proxy to track groups sharing similar chronocultural and burial practices. In particular, from the EDJ shape analysis, individuals buried in an alcove shared a reduction of the distolingual dentin horn tip (corresponding to the hypocone). Environmental, developmental and/or functional underlying causes might be suggested for the origin of phenotypic differences shared by these individuals buried in alcoves.

Post-operative diffusion weighted imaging as a predictor of posterior fossa syndrome permanence in paediatric medulloblastoma.

PubMed

Chua, Felicia H Z; Thien, Ady; Ng, Lee Ping; Seow, Wan Tew; Low, David C Y; Chang, Kenneth T E; Lian, Derrick W Q; Loh, Eva; Low, Sharon Y Y

2017-03-01

Posterior fossa syndrome (PFS) is a serious complication faced by neurosurgeons and their patients, especially in paediatric medulloblastoma patients. The uncertain aetiology of PFS, myriad of cited risk factors and therapeutic challenges make this phenomenon an elusive entity. The primary objective of this study was to identify associative factors related to the development of PFS in medulloblastoma patient post-tumour resection. This is a retrospective study based at a single institution. Patient data and all related information were collected from the hospital records, in accordance to a list of possible risk factors associated with PFS. These included pre-operative tumour volume, hydrocephalus, age, gender, extent of resection, metastasis, ventriculoperitoneal shunt insertion, post-operative meningitis and radiological changes in MRI. Additional variables included molecular and histological subtypes of each patient's medulloblastoma tumour. Statistical analysis was employed to determine evidence of each variable's significance in PFS permanence. A total of 19 patients with appropriately complete data was identified. Initial univariate analysis did not show any statistical significance. However, multivariate analysis for MRI-specific changes reported bilateral DWI restricted diffusion changes involving both right and left sides of the surgical cavity was of statistical significance for PFS permanence. The authors performed a clinical study that evaluated possible risk factors for permanent PFS in paediatric medulloblastoma patients. Analysis of collated results found that post-operative DWI restriction in bilateral regions within the surgical cavity demonstrated statistical significance as a predictor of PFS permanence-a novel finding in the current literature.

Loss of permanent employment and its association with suicidal ideation: a cohort study in South Korea.

PubMed

Yoon, Seohyun; Kim, Ja Young; Park, Jooyoung; Kim, Seung-Sup

2017-09-01

Objective Precarious employment is associated with worse mental health, but it is unclear whether changes in employment status are related to suicidal behaviors. This study examined the association between change in employment status and suicidal ideation among workers in South Korea. Methods To maximize power of the analysis, we combined data from the ongoing Korean Welfare Panel Study. We analyzed 3793 participants who were permanent workers at baseline (2011-2014) and who either: (i) maintained permanent employment; (ii) became a full-time precarious worker; (iii) became a part-time precarious worker; or (iv) became unemployed in the following year (2012-2015). Suicidal ideation was assessed annually by asking participants, "Have you ever seriously thought about dying by suicide in the past year?" Logistic regression was applied to examine associations between change in employment status and suicidal ideation, adjusting for potential confounders such as lifetime suicidal ideation and depressive symptoms at baseline. Results Participants who became part-time precarious workers were more likely to have suicidal ideation [odd ratio (OR) 2.37, 95% confidence interval (95% CI) 1.07-5.25, P=0.033] compared to those who remained permanent workers. In analysis restricted to workers who never previously thought about dying by suicide, suicidal ideation was more common among those who became either full-time (OR 2.33, 95% CI 1.09-4.99, P=0.029) or part-time (OR 3.94, 95% CI 1.46-10.64, P=0.007) precarious workers. Conclusions Our findings suggest that change in employment status from permanent to precarious employment may increase suicidal ideation among workers in South Korea.

Poly(Capro-Lactone) Networks as Actively Moving Polymers

NASA Astrophysics Data System (ADS)

Meng, Yuan

Shape-memory polymers (SMPs), as a subset of actively moving polymers, form an exciting class of materials that can store and recover elastic deformation energy upon application of an external stimulus. Although engineering of SMPs nowadays has lead to robust materials that can memorize multiple temporary shapes, and can be triggered by various stimuli such as heat, light, moisture, or applied magnetic fields, further commercialization of SMPs is still constrained by the material's incapability to store large elastic energy, as well as its inherent one-way shape-change nature. This thesis develops a series of model semi-crystalline shape-memory networks that exhibit ultra-high energy storage capacity, with accurately tunable triggering temperature; by introducing a second competing network, or reconfiguring the existing network under strained state, configurational chain bias can be effectively locked-in, and give rise to two-way shape-actuators that, in the absence of an external load, elongates upon cooling and reversibly contracts upon heating. We found that well-defined network architecture plays essential role on strain-induced crystallization and on the performance of cold-drawn shape-memory polymers. Model networks with uniform molecular weight between crosslinks, and specified functionality of each net-point, results in tougher, more elastic materials with a high degree of crystallinity and outstanding shape-memory properties. The thermal behavior of the model networks can be finely modified by introducing non-crystalline small molecule linkers that effectively frustrates the crystallization of the network strands. This resulted in shape-memory networks that are ultra-sensitive to heat, as deformed materials can be efficiently triggered to revert to its permanent state upon only exposure to body temperature. We also coupled the same reaction adopted to create the model network with conventional free-radical polymerization to prepare a dual-cure "double network" that behaves as a real thermal "actuator". This approach places sub-chains under different degrees of configurational bias within the network to utilize the material's propensity to undergo stress-induced crystallization. Reconfiguration of model shape-memory networks containing photo-sensitive linkages can also be employed to program two-way actuator. Chain reshuffling of a partially reconfigurable network is initiated upon exposure to light under specific strains. Interesting photo-induced creep and stress relaxation behaviors were demonstrated and understood based on a novel transient network model we derived. In summary, delicate manipulation of shape-memory network architectures addressed critical issues constraining the application of this type of functional polymer material. Strategies developed in this thesis may provide new opportunity to the field of shape-memory polymers.

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.

Non-scaling fixed field alternating gradient permanent magnet cancer therapy accelerator

DOEpatents

Trbojevic, Dejan

2017-05-23

A non-scaling fixed field alternating gradient accelerator includes a racetrack shape including a first straight section connected to a first arc section, the first arc section connected to a second straight section, the second straight section connected to a second arc section, and the second arc section connected to the first straight section; an matching cells configured to match particle orbits between the first straight section, the first arc section, the second straight section, and the second arc section. The accelerator includes the matching cells and an associated matching procedure enabling the particle orbits at varying energies between an arc section and a straight section in the racetrack shape.

The Permanent Temps' Lament: Why Not Tenure Status?

ERIC Educational Resources Information Center

Lemon, Hallie S.; And Others

This scripted dialogue is a fully documented story about the history and conditions of one group of post-secondary teachers of English. The narrative focuses on the proposal of this group of "permanent" temporary writing instructors from Western Illinois University to convince administrators to change their status to tenure track by…

Pre-Apprenticeship Urban Workforce Training Programs

ERIC Educational Resources Information Center

Martin, Larry G.; Smith, Regina O.

2011-01-01

Over the past two decades, inner-city communities have witnessed double-digit joblessness among an increasing number of residents who are relegated to the status of the "permanent" unemployed or the permanent underclass. These residents cannot hope to be competitive in a changing and evolving labor market. Relying on public assistance, low-wage…

Assessing Public Opinion Toward the Military

DTIC Science & Technology

1985-05-01

establish and manage any short-falls which might e-ffect national secur i ty? How then has our past developed factors which may shape our -future...experience functioning as advocates. There appears to be a shortage of Air Force officers, trained in human resource management , who have the skills of...colonels; in government, perhaps the permanent senior civil servants; in industry the general managers or the district representatives; in mass

Rolamite acceleration sensor

DOEpatents

Abbin, Joseph P.; Briner, Clifton F.; Martin, Samuel B.

1993-01-01

A rolamite acceleration sensor which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently.

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.

Frontal lobe activation during object permanence: data from near-infrared spectroscopy.

PubMed

Baird, Abigail A; Kagan, Jerome; Gaudette, Thomas; Walz, Kathryn A; Hershlag, Natalie; Boas, David A

2002-08-01

The ability to create and hold a mental schema of an object is one of the milestones in cognitive development. Developmental scientists have named the behavioral manifestation of this competence object permanence. Convergent evidence indicates that frontal lobe maturation plays a critical role in the display of object permanence, but methodological and ethical constrains have made it difficult to collect neurophysiological evidence from awake, behaving infants. Near-infrared spectroscopy provides a noninvasive assessment of changes in oxy- and deoxyhemoglobin and total hemoglobin concentration within a prescribed region. The evidence described in this report reveals that the emergence of object permanence is related to an increase in hemoglobin concentration in frontal cortex.

Dental anomalies in an orthodontic patient population with maxillary lateral incisor agenesis.

PubMed

Citak, Mehmet; Cakici, Elif Bahar; Benkli, Yasin Atakan; Cakici, Fatih; Bektas, Bircan; Buyuk, Suleyman Kutalmış

2016-01-01

The purpose of this study was to evaluate the prevalence of dental anomalies in a subpopulation of orthodontic patients with agenesis of maxillary lateral incisors (MLI). The material of the present study included the records of the 1964 orthodontic patients. Panoramic radiographs and dental casts were used to analyze other associated eight dental anomalies, including agenesis of other teeth, dens invaginatus, dens evaginatus, peg shaped MLI, taurodontism, pulp stone, root dilaceration and maxillary canine impaction. Out of the 1964 patients examined, 90 were found to have agenesis of MLI, representing a prevalence of 4.6%. The most commonly found associated-anomalies were agenesis of other teeth (23.3%), peg-shaped MLIs (15.6%), taurodontism (42.2%), and dilacerated teeth (18.9%). Permanent tooth agenesis, taurodontism, peg-shaped maxillary lateral incisor, and root dilacerations are frequently associated with maxillary lateral incisor agenesis.

Precision shape modification of nanodevices with a low-energy electron beam

DOEpatents

Zettl, Alex; Yuzvinsky, Thomas David; Fennimore, Adam

2010-03-09

Methods of shape modifying a nanodevice by contacting it with a low-energy focused electron beam are disclosed here. In one embodiment, a nanodevice may be permanently reformed to a different geometry through an application of a deforming force and a low-energy focused electron beam. With the addition of an assist gas, material may be removed from the nanodevice through application of the low-energy focused electron beam. The independent methods of shape modification and material removal may be used either individually or simultaneously. Precision cuts with accuracies as high as 10 nm may be achieved through the use of precision low-energy Scanning Electron Microscope scan beams. These methods may be used in an automated system to produce nanodevices of very precise dimensions. These methods may be used to produce nanodevices of carbon-based, silicon-based, or other compositions by varying the assist gas.

A systematic review of dermal fillers for age-related lines and wrinkles.

PubMed

Sturm, Lana P; Cooter, Rodney D; Mutimer, Keith L; Graham, John C; Maddern, Guy J

2011-01-01

Dermal fillers are gaining popularity for rapid aesthetic improvement. Long-term efficacy and safety have not been well documented. The aim of this systematic review was to assess the safety and efficacy of injectable dermal fillers compared with other facial augmentation techniques for the management of age-related lines and wrinkles. Studies including patients receiving injectable semi-permanent or permanent dermal fillers for age-related lines and wrinkles were included in this review. Efficacy outcomes (including changes in skin thickness and patient satisfaction) and safety outcomes (including mortality, lumps and infections) were examined. Three randomized control trials and six case series were included. Permanent and semi-permanent dermal fillers improved subjective ratings of appearance and resulted in higher patient satisfaction than temporary fillers. Long-term efficacy appeared good in the few studies that reported it. Short-term safety appeared favourable. Lumps were reported in all but one study but received little follow-up. Long-term safety data were limited. The treatment of age-related lines and wrinkles with permanent and semi-permanent dermal fillers is more efficacious compared with temporary fillers in those studies that compared them. Case series evidence suggests that these fillers achieve their objective, which is to decrease the visible effects of age-related changes. These fillers appear at least as safe as temporary fillers in the short term in those studies that compared them. Long-term safety could not be determined. © 2010 The Authors. ANZ Journal of Surgery © 2010 Royal Australasian College of Surgeons.

Comparison of Permanent Change of Station Costs for Women and Men Transferred Prematurely from Ships (Computer Diskette).

DTIC Science & Technology

requirements: Post-script. The Objective of this report was to determine whether transferring pregnant women from ships costs the Navy more permanent...change of station (PCS) funds than transferring men and nonpregnant women information was extracted from the enlisted master record concerning gender...from gender-integrated afloat units. The direct costs of transfer prior to PRD was compared for men and women and an estimate of PCS costs, if the ships were not gender-integrated, was also calculated.

Peritoneal sarcomatosis: site of origin for the establishment of an in vitro and in vivo cell line model to study therapeutic resistance in dedifferentiated liposarcoma.

PubMed

Mersch, Sabrina; Riemer, Jasmin C; Schlünder, Philipp M; Ghadimi, Markus P; Ashmawy, Hany; Möhlendick, Birte; Topp, Stefan A; Arent, Tanja; Kröpil, Patric; Stoecklein, Nikolas H; Gabbert, Helmut E; Knoefel, Wolfram T; Krieg, Andreas

2016-02-01

Approximately 50-70 % of patients with retroperitoneal or intraabdominal sarcoma develop a relapse after surgical therapy, including peritoneal sarcomatosis, an extremely rare site of metastatic disease which is associated with an extremely poor prognosis. Accordingly, the establishment of a permanent cell line derived from peritoneal sarcomatosis might provide a helpful tool to understand the biological behavior and to develop new therapeutic strategies. Thus, we established and characterized a liposarcoma cell line (Lipo-DUE1) from a peritoneal sarcomatosis that was permanently cultured without showing any morphological changes. Lipo-DUE1 cells exhibited a spindle-shaped morphology and positive staining for S100. Tumorigenicity was demonstrated in vitro by invasion and migration assays and in vivo by using a subcutaneous xenograft mouse model. In addition, aCGH analysis revealed concordant copy number variations on chromosome 12q in the primary tumor, peritoneal sarcomatosis, and Lipo-DUE1 cells that are commonly observed in liposarcoma. Chemotherapeutic sensitivity assays revealed a pronounced drug-resistant phenotype of Lipo-DUE1 cells to conventionally used chemotherapeutic agents. In conclusion, we describe for the first time the establishment and characterization of a liposarcoma cell line derived from a peritoneal sarcomatosis. Hence, in the future, the newly established cell line Lipo-DUE1 might serve as a useful in vitro and in vivo model to investigate the biological behavior of liposarcoma and to assess novel targeted therapies.

Cumulative impacts of hurricanes on Florida mangrove ecosystems: Sediment deposition, storm surges and vegetation

USGS Publications Warehouse

Smith, T. J.; Anderson, G.H.; Balentine, K.; Tiling, G.; Ward, G.A.; Whelan, K.R.T.

2009-01-01

Hurricanes have shaped the structure of mangrove forests in the Everglades via wind damage, storm surges and sediment deposition. Immediate effects include changes to stem size-frequency distributions and to species relative abundance and density. Long-term impacts to mangroves are poorly understood at present. We examine impacts of Hurricane Wilma on mangroves and compare the results to findings from three previous storms (Labor Day, Donna, Andrew). Surges during Wilma destroyed ??? 1,250 ha of mangroves and set back recovery that started following Andrew. Data from permanent plots affected by Andrew and Wilma showed no differences among species or between hurricanes for stem mortality or basal area lost. Hurricane damage was related to hydro-geomorphic type of forest. Basin mangroves suffered significantly more damage than riverine or island mangroves. The hurricane by forest type interaction was highly significant. Andrew did slightly more damage to island mangroves. Wilma did significantly more damage to basin forests. This is most likely a result of the larger and more spatially extensive storm surge produced by Wilma. Forest damage was not related to amount of sediment deposited. Analyses of reports from Donna and the Labor Day storm indicate that some sites have recovered following catastrophic disturbance. Other sites have been permanently converted into a different ecosystem, namely intertidal mudflats. Our results indicate that mangroves are not in a steady state as has been recently claimed. ?? 2009 The Society of Wetland Scientists.

Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

NASA Astrophysics Data System (ADS)

Simos, Nikolaos; Fernandes, S.; Mittig, Wolfgang; Pellemoine, Frederique; Avilov, M.; Kostin, M.; Mausner, L.; Ronningen, R.; Schein, M.; Bollen, G.

2017-01-01

Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

Effects of hydrology on zooplankton communities in high-mountain ponds, Mount Rainier National Park, USA

USGS Publications Warehouse

Girdner, Scott; Larson, Gary L.

1995-01-01

Ten high-mountain ponds in Mount Rainier National Park, Washington State, were studied from ice-out in June through September1992 to investigate the influences of fluctuating pond volumes on zooplankton communities. All of the ponds were at maximum volume immediately after ice-out. The temporary pond with the shortest wet phase was inhabited by rotifer taxa with short generation times and a crustacean taxon with the ability to encyst as drought-resistant resting bodies at immature stages of development. Dominant zooplankton taxa in three other temporary ponds and six permanent ponds were similar. Rotifer densities typically were lower in temporary ponds relative to those in permanent ponds, although Brachionus urceolaris was abundant shortly before the temporary ponds dried. Large volume loss was associated with large declines in total abundances of crustacean populations. Daphnia rosea was not present in temporary ponds following fall recharge. In deep-permanent ponds, copepods had slower developmental rates, smaller temporal changes in total abundances of crustacean populations and two additional large-bodied crustacean taxa were present relative to the characteristics of crustacean communities in shallow-permanent ponds. Owing to their small sizes and sensitivity to environmental change, collectively ponds such as these may provide an early signal of long-term climate change in aquatic systems.

Subject-specific longitudinal shape analysis by coupling spatiotemporal shape modeling with medial analysis

NASA Astrophysics Data System (ADS)

Hong, Sungmin; Fishbaugh, James; Rezanejad, Morteza; Siddiqi, Kaleem; Johnson, Hans; Paulsen, Jane; Kim, Eun Young; Gerig, Guido

2017-02-01

Modeling subject-specific shape change is one of the most important challenges in longitudinal shape analysis of disease progression. Whereas anatomical change over time can be a function of normal aging, anatomy can also be impacted by disease related degeneration. Anatomical shape change may also be affected by structural changes from neighboring shapes, which may cause non-linear variations in pose. In this paper, we propose a framework to analyze disease related shape changes by coupling extrinsic modeling of the ambient anatomical space via spatiotemporal deformations with intrinsic shape properties from medial surface analysis. We compare intrinsic shape properties of a subject-specific shape trajectory to a normative 4D shape atlas representing normal aging to isolate shape changes related to disease. The spatiotemporal shape modeling establishes inter/intra subject anatomical correspondence, which in turn enables comparisons between subjects and the 4D shape atlas, and also quantitative analysis of disease related shape change. The medial surface analysis captures intrinsic shape properties related to local patterns of deformation. The proposed framework jointly models extrinsic longitudinal shape changes in the ambient anatomical space, as well as intrinsic shape properties to give localized measurements of degeneration. Six high risk subjects and six controls are randomly sampled from a Huntington's disease image database for qualitative and quantitative comparison.

Assessing systemic barriers to permanency achievement for children in out-of-home care: development of the child permanency barriers scale.

PubMed

Murphy, April L; Van Zyl, Riaan; Collins-Camargo, Crystal; Sullivan, Dana

2012-01-01

State and local child welfare agencies are engaged in multiple efforts to enact systems change to improve outcomes, particularly in regard to achievement of child permanency. The Child and Family Services Review process, conducted by the Administration Children and Families, requires states to implement program improvement plans designed to improve outcomes for which they are not meeting national standards. However, a tool has not been demonstrated as useful in assessing the barriers to achievement of permanency across the out-of-home service continuum, from recruitment of families to placement stability. This article reports on the development and refinement of such a tool in one Midwestern state. The Child Permanency Barriers Scale has four factors: kinship, placement and matching, adequate services and resources, and communication and collaboration. Implications for use in state-specific and multisystem assessment and system reform are discussed.

24 CFR 883.308 - Adjustments to reflect changes in terms of financing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... projected rate of borrowing (net interest cost), based on a reasonable evaluation of market conditions, on obligations issued to provide interim and permanent financing for the project, (2) The projected cost of..., (4) The projected cost of borrowing and the term of the permanent financing to be provided to the...

Biological factors contributing to bark and ambrosia beetle species diversification.

PubMed

Gohli, Jostein; Kirkendall, Lawrence R; Smith, Sarah M; Cognato, Anthony I; Hulcr, Jiri; Jordal, Bjarte H

2017-05-01

The study of species diversification can identify the processes that shape patterns of species richness across the tree of life. Here, we perform comparative analyses of species diversification using a large dataset of bark beetles. Three examined covariates-permanent inbreeding (sibling mating), fungus farming, and major host type-represent a range of factors that may be important for speciation. We studied the association of these covariates with species diversification while controlling for evolutionary lag on adaptation. All three covariates were significantly associated with diversification, but fungus farming showed conflicting patterns between different analyses. Genera that exhibited interspecific variation in host type had higher rates of species diversification, which may suggest that host switching is a driver of species diversification or that certain host types or forest compositions facilitate colonization and thus allopatric speciation. Because permanent inbreeding is thought to facilitate dispersal, the positive association between permanent inbreeding and diversification rates suggests that dispersal ability may contribute to species richness. Bark beetles are ecologically unique; however, our results indicate that their impressive species diversity is largely driven by mechanisms shown to be important for many organism groups. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

A Proposal for the Establishment of a Center for Advanced Composite Materials Research

DTIC Science & Technology

1992-03-01

materials. We were able to synthesize comb-shaped self-ordering polymers in which molecular teeth were functionalized at their termini. These chemical...layers were most likely transferred with phenolic functional groups exposed on the outer surface. For the fibers coated with polymer, contact angle...cured epoxy matrix. A striking result was observed, namely, the permanent birefringence obtained with coated fibers is 1.8 times greater than the one

Rolamite acceleration sensor

DOEpatents

Abbin, J.P.; Briner, C.F.; Martin, S.B.

1993-12-21

A rolamite acceleration sensor is described which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently. 6 figures.

High-resolution mapping of global surface water and its long-term changes

NASA Astrophysics Data System (ADS)

Pekel, Jean-François; Cottam, Andrew; Gorelick, Noel; Belward, Alan S.

2016-12-01

The location and persistence of surface water (inland and coastal) is both affected by climate and human activity and affects climate, biological diversity and human wellbeing. Global data sets documenting surface water location and seasonality have been produced from inventories and national descriptions, statistical extrapolation of regional data and satellite imagery, but measuring long-term changes at high resolution remains a challenge. Here, using three million Landsat satellite images, we quantify changes in global surface water over the past 32 years at 30-metre resolution. We record the months and years when water was present, where occurrence changed and what form changes took in terms of seasonality and persistence. Between 1984 and 2015 permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, though new permanent bodies of surface water covering 184,000 square kilometres have formed elsewhere. All continental regions show a net increase in permanent water, except Oceania, which has a fractional (one per cent) net loss. Much of the increase is from reservoir filling, although climate change is also implicated. Loss is more geographically concentrated than gain. Over 70 per cent of global net permanent water loss occurred in the Middle East and Central Asia, linked to drought and human actions including river diversion or damming and unregulated withdrawal. Losses in Australia and the USA linked to long-term droughts are also evident. This globally consistent, validated data set shows that impacts of climate change and climate oscillations on surface water occurrence can be measured and that evidence can be gathered to show how surface water is altered by human activities. We anticipate that this freely available data will improve the modelling of surface forcing, provide evidence of state and change in wetland ecotones (the transition areas between biomes), and inform water-management decision-making.

Design and development of novel antibacterial Ti-Ni-Cu shape memory alloys for biomedical application.

PubMed

Li, H F; Qiu, K J; Zhou, F Y; Li, L; Zheng, Y F

2016-11-29

In the case of medical implants, foreign materials are preferential sites for bacterial adhesion and microbial contamination, which can lead to the development of prosthetic infections. Commercially biomedical TiNi shape memory alloys are the most commonly used materials for permanent implants in contact with bone and dental, and the prevention of infections of TiNi biomedical shape memory alloys in clinical cases is therefore a crucial challenge for orthopaedic and dental surgeons. In the present study, copper has been chosen as the alloying element for design and development novel ternary biomedical Ti‒Ni‒Cu shape memory alloys with antibacterial properties. The effects of copper alloying element on the microstructure, mechanical properties, corrosion behaviors, cytocompatibility and antibacterial properties of biomedical Ti‒Ni‒Cu shape memory alloys have been systematically investigated. The results demonstrated that Ti‒Ni‒Cu alloys have good mechanical properties, and remain the excellent shape memory effects after adding copper alloying element. The corrosion behaviors of Ti‒Ni‒Cu alloys are better than the commercial biomedical Ti‒50.8Ni alloys. The Ti‒Ni‒Cu alloys exhibit excellent antibacterial properties while maintaining the good cytocompatibility, which would further guarantee the potential application of Ti‒Ni‒Cu alloys as future biomedical implants and devices without inducing bacterial infections.

Design and development of novel antibacterial Ti-Ni-Cu shape memory alloys for biomedical application

NASA Astrophysics Data System (ADS)

Li, H. F.; Qiu, K. J.; Zhou, F. Y.; Li, L.; Zheng, Y. F.

2016-11-01

In the case of medical implants, foreign materials are preferential sites for bacterial adhesion and microbial contamination, which can lead to the development of prosthetic infections. Commercially biomedical TiNi shape memory alloys are the most commonly used materials for permanent implants in contact with bone and dental, and the prevention of infections of TiNi biomedical shape memory alloys in clinical cases is therefore a crucial challenge for orthopaedic and dental surgeons. In the present study, copper has been chosen as the alloying element for design and development novel ternary biomedical Ti‒Ni‒Cu shape memory alloys with antibacterial properties. The effects of copper alloying element on the microstructure, mechanical properties, corrosion behaviors, cytocompatibility and antibacterial properties of biomedical Ti‒Ni‒Cu shape memory alloys have been systematically investigated. The results demonstrated that Ti‒Ni‒Cu alloys have good mechanical properties, and remain the excellent shape memory effects after adding copper alloying element. The corrosion behaviors of Ti‒Ni‒Cu alloys are better than the commercial biomedical Ti‒50.8Ni alloys. The Ti‒Ni‒Cu alloys exhibit excellent antibacterial properties while maintaining the good cytocompatibility, which would further guarantee the potential application of Ti‒Ni‒Cu alloys as future biomedical implants and devices without inducing bacterial infections.

Shape Memory Actuated Normally Open Permanent Isolation Valve

NASA Technical Reports Server (NTRS)

Ramspacher, Daniel J. (Inventor); Bacha, Caitlin E. (Inventor)

2017-01-01

A valve assembly for an in-space propulsion system includes an inlet tube, an outlet tube, a valve body coupling the inlet tube to the outlet tube and defining a propellant flow path, a valve stem assembly disposed within the valve body, an actuator body coupled to the valve body, the valve stem assembly extending from an interior of the valve body to an interior of the actuator body, and an actuator assembly disposed within the actuator body and coupled to the valve stem assembly, the actuator assembly including a shape memory actuator member that when heated to a transition temperature is configured to enable the valve stem assembly to engage the outlet tube and seal the propellant flow path.

Very Large Area/Volume Microwave ECR Plasma and Ion Source

NASA Technical Reports Server (NTRS)

Foster, John E. (Inventor); Patterson, Michael J. (Inventor)

2009-01-01

The present invention is an apparatus and method for producing very large area and large volume plasmas. The invention utilizes electron cyclotron resonances in conjunction with permanent magnets to produce dense, uniform plasmas for long life ion thruster applications or for plasma processing applications such as etching, deposition, ion milling and ion implantation. The large area source is at least five times larger than the 12-inch wafers being processed to date. Its rectangular shape makes it easier to accommodate to materials processing than sources that are circular in shape. The source itself represents the largest ECR ion source built to date. It is electrodeless and does not utilize electromagnets to generate the ECR magnetic circuit, nor does it make use of windows.

Temperature and field direction dependences of first-order reversal curve (FORC) diagrams of hot-deformed Nd-Fe-B magnets

NASA Astrophysics Data System (ADS)

Yomogita, Takahiro; Okamoto, Satoshi; Kikuchi, Nobuaki; Kitakami, Osamu; Sepehri-Amin, Hossein; Ohkubo, Tadakatsu; Hono, Kazuhiro; Akiya, Takahiro; Hioki, Keiko; Hattori, Atsushi

2018-02-01

First-order reversal curve (FORC) diagram has been previously adopted for the analyses of magnetization reversal process and/or quantitative evaluation of coercivity and interaction field dispersions in various magnetic samples. Although these kinds of information are valuable for permanent magnets, previously reported FORC diagrams of sintered Nd-Fe-B magnets exhibit very complicated patterns. In this paper, we have studied the FORC diagrams of hot-deformed Nd-Fe-B magnets under various conditions. Contrary to the previous reports on sintered Nd-Fe-B magnets, the FORC diagram of the hot-deformed Nd-Fe-B magnet exhibits a very simple pattern consisting of a strong spot and a weak line. From this FORC diagram pattern, it is revealed that the coercivity dispersion of the hot-deformed Nd-Fe-B magnets is surprisingly small. Moreover, this feature of the FORC diagram pattern is very robust and unaffected by changes in various conditions such as grain boundary diffusion process, temperature, and field direction, whereas these conditions significantly change the coercivity and the shape of magnetization curve. This fact indicates that the magnetization reversal process of the hot-deformed Nd-Fe-B magnets is almost unchanged against these conditions.

Zygomatic bone shape in intentional cranial deformations: a model for the study of the interactions between skull growth and facial morphology.

PubMed

Ketoff, S; Girinon, F; Schlager, S; Friess, M; Schouman, T; Rouch, P; Khonsari, R H

2017-04-01

Intentional cranial deformations (ICD) were obtained by exerting external mechanical constraints on the skull vault during the first years of life to permanently modify head shape. The repercussions of ICD on the face are not well described in the midfacial region. Here we assessed the shape of the zygomatic bone in different types of ICDs. We considered 14 non-deformed skulls, 19 skulls with antero-posterior deformation, nine skulls with circumferential deformation and seven skulls with Toulouse deformation. The shape of the zygomatic bone was assessed using a statistical shape model after mesh registration. Euclidian distances between mean models and Mahalanobis distances after canonical variate analysis were computed. Classification accuracy was computed using a cross-validation approach. Different ICDs cause specific zygomatic shape modifications corresponding to different degrees of retrusion but the shape of the zygomatic bone alone is not a sufficient parameter for classifying populations into ICD groups defined by deformation types. We illustrate the fact that external mechanical constraints on the skull vault influence midfacial growth. ICDs are a model for the study of the influence of epigenetic factors on craniofacial growth and can help to understand the facial effects of congenital skull malformations such as single or multi-suture synostoses, or of external orthopedic devices such as helmets used to correct deformational plagiocephaly. © 2016 Anatomical Society.

Effects of Stoichiometry on Transformation Temperatures and Actuator-Type Performance of NiTiPd and NiTiPdX High-Temperature Shape Memory Alloys

NASA Technical Reports Server (NTRS)

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

2007-01-01

High-temperature shape memory NiTiPd and NiTiPdX (X=Au, Pt, Hf) alloys were produced with titanium equivalent (Ti+Hf) compositions of 50.5, 50.0, 49.5, and 49.0 at.%. Thermo-mechanical testing in compression was used to evaluate the transformation temperatures, transformation strain, work output, and permanent deformation behavior of each alloy to study the effects of quaternary alloying and stoichiometry on high-temperature shape memory alloy behavior. Microstructural evaluation showed the presence of second phases for all alloy compositions. No load transformation temperatures in the stoichiometric alloys were relatively unchanged by Au and Pt substitutions, while the substitution of Hf for Ti causes a drop in transformation temperatures. The NiTiPd, NiTiPdAu and NiTiPdHf alloys exhibited transformation temperatures that were highest in the Ti-rich compositions, slightly lower at stoichiometry, and significantly reduced when the Ti equivalent composition was less than 50 at.%. For the NiTiPdPt alloy, transformation temperatures were highest for the Ti-rich compositions, lowest at stoichiometry, and slightly higher in the Ni-rich composition. When thermally cycled under constant stresses of up to 300 MPa, all of the alloys had transformation strains, and therefore work outputs, which increased with increasing stress. In each series of alloys, the transformation strain and thus work output was highest for stoichiometric or Ti-rich compositions while permanent strain associated with the constant-load thermal cycling was lowest for alloys with Ni-equivalent-rich compositions. Based on these results, basic rules for optimizing the composition of NiTiPd alloys for actuator performance will be discussed.

[Preliminary study of constructing tissue-engineered cartilage with the endoskeletal scaffold of HDPE by bone marrow stromal cells].

PubMed

Zhu, Lie; Jiang, Hua; Zhou, Guang-Dong; Wu, Yu-Jia; Luo, Xu-Song

2008-09-01

To explore the feasibility of using a nonreactive, permanent endoskeletal scaffold to create the prothesis in special shape which is covered with tissue-engineered cartilage. Porcine BMSCs and articular chondrocytes were isolated and expanded respectively in vitro. Porcine BMSC of passage 1 in the concentration of 10 x 10(7)/ml were seeded onto a cylinder-shaped PGA (1 mm in thickness)/Medpor (3mm in diameter and 5mm in highness) scaffold as the experimental group. After the cell-scaffold constructs were cultured for 5 days, the primary medium, high-glucose DMEM medium with 10% fetal bovine serum (FBS), was replaced by chondrogenically inductive medium for 4 weeks. BMSCs and chondrocytes of the same concentration were seeded respectively onto the scaffold as the negative control group and the positive control group. After cultured in vitro for 4 weeks, the cell-scaffolds construct were implanted into subcutaneous pockets on the back of nude mice. Four and eight weeks later, the formed cartilage prosthesis were harvested and then evaluated by gross view, histology, immunohistochemistry and glycosamino-glycan (GAG) content. Cells in all groups had fine adhesion to the scaffold and could secrete extracellular matrix. All specimens in experimental group and positive control group formed mature cartilage with collagen II expression.The mature catrtilage wraped HDPE compactly and grown into the gap of HDPE. Mature lacuna structures and metachromatic matrices were also observed in these specimens. GAG contents in experimental group were (5.13 +/- 0.32) mg/g (4 weeks), (5.37 +/- 0.12) mg/g (8 weeks). In contrast, specimens in BMSC group showed mainly fibrous tissue. It indicates that it is feasible to create special shaped tissue-engineering cartilage with the permanent internal support using BMSCs as seed cell.

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.

Guide for Development of Permanent Part-Time Employment Opportunities for Girls and Women.

ERIC Educational Resources Information Center

Berry, Jane; And Others

Development of permanent part time employment is seen as a solution to employer needs and the changing life style of women; opportunities exist in banking, retail sales, education, and government agencies. Development of such positions will demand from employers and employment services the assessing of jobs for part time potential, publicizing…

36 CFR 228.104 - Consideration of requests to modify, waive, or grant exceptions to lease stipulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... An operator submitting a surface use plan of operations may request the authorized Forest officer to authorize the Bureau of Land Management to modify (permanently change), waive (permanently remove), or grant... Forest officer may authorize the Bureau of Land Management to modify, waive, or grant an exception to a...

An Original Behavior Modification Program for Weight Reduction: Minimal Intervention and Permanent Habit Change.

ERIC Educational Resources Information Center

Lublin, Irwin; Kirkish, Patricia

This description of a weight reduction program, based on generalizations derived from eight years of work with overweight persons, discusses the clients' rationalization of overeating behaviors. In this behavior modification program, the client is required to permanently give up one high calorie food and to write down all foods eaten before actual…

"The Piety of Degradation": Kenneth Burke, the Bureau of Social Hygiene, and "Permanence and Change"

ERIC Educational Resources Information Center

Jack, Jordynn

2004-01-01

Kenneth Burke's employment with the Bureau of Social Hygiene informed his rhetorical theory in the 1930s. Between 1926 and 1930, Burke researched criminology and drug addiction and ghostwrote a book for Colonel Arthur Woods, "Dangerous Drugs". An investigation of archives indicates that this research left its mark on Burke's "Permanence and…

GPS IPW as a Meteorological Parameter and Climate Global Change Indicator

NASA Astrophysics Data System (ADS)

Kruczyk, M.; Liwosz, T.

2011-12-01

Paper focuses on comprehensive investigation of the GPS derived IPW (Integrated Precipitable Water, also IWV) as a geophysical tool. GPS meteorology is now widely acknowledged indirect method of atmosphere sensing. First we demonstrate GPS IPW quality. Most thorough inter-technique comparisons of directly measured IPW are attainable only for some observatories (note modest percentage of GPS stations equipped with meteorological devices). Nonetheless we have managed to compare IPW series derived from GPS tropospheric solutions (ZTD mostly from IGS and EPN solutions) and some independent techniques. IPW values from meteorological sources we used are: radiosoundings, sun photometer and input fields of numerical weather prediction model. We can treat operational NWP models as meteorological database within which we can calculate IWV for all GPS stations independently from network of direct measurements (COSMO-LM model maintained by Polish Institute of Meteorology and Water Management was tried). Sunphotometer (CIMEL-318, Central Geophysical Observatory IGF PAS, Belsk, Poland) data seems the most genuine source - so we decided for direct collocation of GPS measurements and sunphotometer placing permanent GPS receiver on the roof of Belsk Observatory. Next we analyse IPW as geophysical parameter: IPW demonstrates some physical effects evoked by station location (height and series correlation coefficient as a function of distance) and weather patterns like dominant wind directions (in case of neighbouring stations). Deficiency of surface humidity data to model IPW is presented for different climates. This inadequacy and poor humidity data representation in NWP model extremely encourages investigating information exchange potential between Numerical Model and GPS network. The second and most important aspect of this study concerns long series of IPW (daily averaged) which can serve as climatological information indicator (water vapour role in climate system is hard to exaggerate). Especially intriguing are relatively unique shape of such series in different climates. Long lasting changes in weather conditions: 'dry' and 'wet' years are also visible. The longer and more uniform our series are the better chance to estimate the magnitude of climatological IWV changes. Homogenous ZTD solution during long period is great concern in this approach (problems with GPS strategy and reference system changes). In case of continental network (EUREF Permanent Network) reliable data we get only after reprocessing. Simple sinusoidal model has been adjusted to the IPW series (LS method) for selected stations (mainly Europe but also other continents - IGS stations), every year separately. Not only amplitudes but also phases of annual signal differ from year to year. Longer IPW series (up to 14 years) searched for some climatological signal sometimes reveal weak steady trend. Large number of GPS permanent stations, relative easiness of IPW derivation (only and surface meteo data needed apart from GPS solution) and water vapour significance in water cycle and global climate make this GPS IPW promising element of global environmental change monitoring.

Different Facets of Copy Number Changes: Permanent, Transient, and Adaptive

PubMed Central

Mishra, Sweta

2016-01-01

Chromosomal copy number changes are frequently associated with harmful consequences and are thought of as an underlying mechanism for the development of diseases. However, changes in copy number are observed during development and occur during normal biological processes. In this review, we highlight the causes and consequences of copy number changes in normal physiologic processes as well as cover their associations with cancer and acquired drug resistance. We discuss the permanent and transient nature of copy number gains and relate these observations to a new mechanism driving transient site-specific copy gains (TSSGs). Finally, we discuss implications of TSSGs in generating intratumoral heterogeneity and tumor evolution and how TSSGs can influence the therapeutic response in cancer. PMID:26755558

Effect of glyphosate-based herbicide on early life stages of Java medaka (Oryzias javanicus): a potential tropical test fish.

PubMed

Yusof, Shahrizad; Ismail, Ahmad; Alias, Mohamad Shafiq

2014-08-30

Glyphosate is globally a widely used herbicide, yet there is little information on their toxicity to marine fishes. Java medaka, a small tropical fish native to coastal areas in several Southeast Asian countries, is viewed as a suitable candidate for toxicity test and thus was used for this study. Java medaka adults were cultured in the laboratory and the fertilized eggs of the F2 generation were exposed to different concentrations of glyphosate-based herbicide (100, 200, 300, 400 and 500 ppm) until they hatched. The survival and hatching rates of the embryos, changes in the heart rate and morphological impairments were recorded. Generally, survival and hatching percentage decreased as glyphosate concentration increased. Absence of pectoral fin(s) and cornea, permanently bent tail, irregular shaped abdomen, and cell disruption in the fin, head and abdomen are among the common teratogenic effects observed. Furthermore, risk factor also increased with the increased in glyphosate concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

The impact of perinatal stress on the functional maturation of prefronto-cortical synaptic circuits: implications for the pathophysiology of ADHD?

PubMed

Bock, Jörg; Braun, Katharina

2011-01-01

Enriched as well as impoverished or adverse perinatal environment plays an essential role in the development and refinement of neuronal pathways, which are the neural substrate of intellectual capacity and socioemotional competence. Perinatal experience and learning events continuously interact with the adaptive shaping of excitatory, inhibitory, and neuromodulatory synaptic as well as the endocrine stress systems, including the neuronal corticotropin-releasing factor (CRF) pathways. Adverse environments, such as stress and emotional deprivation can not only delay experience-dependent maturation of these pathways, but also induce permanent changes in prefronto-cortical wiring patterns. We assume that such dysfunctional connections are the neuronal basis for the development of psychosocially induced mental disorders during later life. The aim of this review is to focus on the impact of perinatal stress on the neuronal and synaptic reorganization during brain development and possible implications for the etiology and therapy of mental disorders such as ADHD. Copyright © 2011 Elsevier B.V. All rights reserved.

Long-lived monolithic micro-optics for multispectral GRIN applications.

PubMed

Lepicard, Antoine; Bondu, Flavie; Kang, Myungkoo; Sisken, Laura; Yadav, Anupama; Adamietz, Frederic; Rodriguez, Vincent; Richardson, Kathleen; Dussauze, Marc

2018-05-09

The potential for realizing robust, monolithic, near-surface refractive micro-optic elements with long-lived stability is demonstrated in visible and infrared transmitting glasses capable of use in dual band applications. Employing an enhanced understanding of glass chemistry and geometric control of mobile ion migration made possible with electrode patterning, flat, permanent, thermally-poled micro-optic structures have been produced and characterized. Sub-surface (t~5-10 µm) compositional and structural modification during the poling process results in formation of spatially-varying refractive index profiles, exhibiting induced Δn changes up to 5 × 10 -2 which remain stable for >15 months. The universality of this approach applied to monolithic vis-near infrared [NIR] oxide and NIR-midwave infrared [MIR] chalcogenide glass materials is demonstrated for the first time. Element size, shape and gradient profile variation possible through pattern design and fabrication is shown to enable a variety of design options not possible using other GRIN process methodologies.

Role of Marine Snows in Microplastic Fate and Bioavailability.

PubMed

Porter, Adam; Lyons, Brett P; Galloway, Tamara S; Lewis, Ceri

2018-06-19

Microplastics contaminate global oceans and are accumulating in sediments at levels thought sufficient to leave a permanent layer in the fossil record. Despite this, the processes that vertically transport buoyant polymers from surface waters to the benthos are poorly understood. Here we demonstrate that laboratory generated marine snows can transport microplastics of different shapes, sizes, and polymers away from the water surface and enhance their bioavailability to benthic organisms. Sinking rates of all tested microplastics increased when incorporated into snows, with large changes observed for the buoyant polymer polyethylene with an increase in sinking rate of 818 m day -1 and for denser polyamide fragments of 916 m day -1 . Incorporation into snows increased microplastic bioavailability for mussels, where uptake increased from zero to 340 microplastics individual -1 for free microplastics to up to 1.6 × 10 5 microplastics individual -1 when incorporated into snows. We therefore propose that marine snow formation and fate has the potential to play a key role in the biogeochemical processing of microplastic pollution.

Reciprocating linear motor

NASA Technical Reports Server (NTRS)

Goldowsky, Michael P. (Inventor)

1987-01-01

A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.

Emittance studies of the 2.45 GHz permanent magnet ECR ion source

NASA Astrophysics Data System (ADS)

Zelenak, A.; Bogomolov, S. L.; Yazvitsky, N. Yu.

2004-05-01

During the past several years different types of permanent magnet 2.45 GHz (electron cyclotron resonance) ion sources were developed for production of singly charged ions. Ion sources of this type are used in the first stage of DRIBs project, and are planned to be used in the MASHA mass separator. The emittance of the beam provided by the source is one of the important parameters for these applications. An emittance scanner composed from a set of parallel slits and rotary wire beam profile monitor was used for the studying of the beam emittance characteristics. The emittance of helium and argon ion beams was measured with different shapes of the plasma electrode for several ion source parameters: microwave power, source potential, plasma aperture-puller aperture gap distance, gas pressure. The results of measurements are compared with previous simulations of ion optics.

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.

Changes in the prevalence of dental caries in primary school children in Lagos State, Nigeria.

PubMed

Sofola, O O; Folayan, M O; Oginni, A B

2014-01-01

To evaluate the changes in the prevalence of dental caries in Lagos State over a 3 years period and the role of age, sex, and playing in the changes observed. Three primary schools in Lagos State, Nigeria were randomly selected for the study. Six hundred and thirty-three children age 2-12 years, were examined for caries in 2000 while 513 children were examined in 2003. The prevalence of tooth decay and the prevalence of untreated tooth decay were calculated for the two years, that is, 2000 and 2003. Also the degree of unmet treatment need among the population with caries experience was measured. Differences in the prevalence and severity of dental caries in the primary and permanent dentition were assessed. Approximately 18% of children had untreated tooth decay in their primary dentition in 2003: A 26.1% increase from 2000. About 12.0% of the decay, extracted, and filled teeth (deft) index was seen with decayed teeth in 2000 and 16.6% in 2003. Extracted primary teeth decreased from 2.5% in 2000 to 1.5% in 2003. The change in mean deft between 2000 (0.42) and 2003 (0.47) was 11.9%. Over the study period, the overall reduction in the prevalence of dental caries was 34.8% in the permanent dentition. The decline was larger among children aged 5-9 years (62.1%) and among females (75%). The study showed no overall changes in caries severity but a decrease in caries prevalence in the permanent dentition over the study period. The largest decline in caries prevalence in the permanent dentition was observed in children aged 5-9 years and females. On the contrary, there was an increase in the caries prevalence in the primary dentition.

Conversion of a Temporary Tent with Steel Frame into a Permanent Warehouse

NASA Astrophysics Data System (ADS)

Georgescu, Mircea; Ungureanu, Viorel; Grecea, Daniel; Petran, Ioan

2017-10-01

The paper is dealing with the problem of a functional conversion (involving both architectural and structural issues) applied to the case of an industrial building. As well known, temporary tents, designed according to the European Code EN13782, represent a remarkable stake on the building market and a fast and practical solution for some situations. It is exactly the case approached by the paper, where the investor has initially decided to erect on his platform a provisional shelter for agricultural machines and subsequent staff, built of a light steel structure covered by PVC roofing and cladding. This temporary tent has been acquired from a specialized supplier in form of a series product. After using the tent for a number of years, the investor has decided to convert the existing structure from architectural and structural point of view by switching to a permanent structure designed accordingly. Important changes were thus imposed both to the architectural part (technological flows, openings, facades) and especially to the structural part where this switch imposed a re-design to the codes of permanent structures (especially as far as climatic loadings are concerned). The required architectural change implied the building of a 70 cm high concrete plinth and replacing the PVC membrane temporary roofing and cladding by permanent 60 mm thick PUR sandwich panels. Together with a new system of openings this has led to renewed facades of the buildings. As for the structural change, the required conversion has imposed a thorough checking of the existing steel structure (very slender and typical to a tent) in view of transforming it into a permanent structure. The consolidation measures of the existing galvanized steel structure are described, together with the measures applied at infrastructure level in order to implement the required conversion.

Identifying Attributes of CO2 Leakage Zones in Shallow Aquifers Using a Parametric Level Set Method

NASA Astrophysics Data System (ADS)

Sun, A. Y.; Islam, A.; Wheeler, M.

2016-12-01

Leakage through abandoned wells and geologic faults poses the greatest risk to CO2 storage permanence. For shallow aquifers, secondary CO2 plumes emanating from the leak zones may go undetected for a sustained period of time and has the greatest potential to cause large-scale and long-term environmental impacts. Identification of the attributes of leak zones, including their shape, location, and strength, is required for proper environmental risk assessment. This study applies a parametric level set (PaLS) method to characterize the leakage zone. Level set methods are appealing for tracking topological changes and recovering unknown shapes of objects. However, level set evolution using the conventional level set methods is challenging. In PaLS, the level set function is approximated using a weighted sum of basis functions and the level set evolution problem is replaced by an optimization problem. The efficacy of PaLS is demonstrated through recovering the source zone created by CO2 leakage into a carbonate aquifer. Our results show that PaLS is a robust source identification method that can recover the approximate source locations in the presence of measurement errors, model parameter uncertainty, and inaccurate initial guesses of source flux strengths. The PaLS inversion framework introduced in this work is generic and can be adapted for any reactive transport model by switching the pre- and post-processing routines.

Temperature and hydrology affect methane emissions from Prairie Pothole Wetlands

USGS Publications Warehouse

Bansal, Sheel; Tangen, Brian; Finocchiaro, Raymond

2016-01-01

The Prairie Pothole Region (PPR) in central North America consists of millions of depressional wetlands that each have considerable potential to emit methane (CH4). Changes in temperature and hydrology in the PPR from climate change may affect methane fluxes from these wetlands. To assess the potential effects of changes in climate on methane emissions, we examined the relationships between flux rates and temperature or water depth using six years of bi-weekly flux measurements during the snow-free period from six temporarily ponded and six permanently ponded wetlands in North Dakota, USA. Methane flux rates were among the highest reported for freshwater wetlands, and had considerable spatial and temporal variation. Methane flux rates increased with increasing temperature and water depth, and were especially high when conditions were warmer and wetter than average (163 ± 28 mg CH4 m−2 h−1) compared to warmer and drier (37 ± 7 mg CH4 m−2 h−1). Methane emission rates from permanent wetlands were less sensitive to changes in temperature and water depth compared to temporary wetlands, likely due to higher sulfate concentrations in permanent wetlands. While the predicted increase in temperature with climate change will likely increase methane emission rates from PPR wetlands, drier conditions could moderate these increases.

Additive manufacturing of permanent magnets

DOE PAGES

Paranthaman, M. P.; Nlebedim, I. C.; Johnson, F.; ...

2016-10-28

Here, permanent magnets enable energy conversion. Motors and generators are used to convert both electrical to mechanical energy and mechanical to electrical energy, respectively. They are precharged (magnetized) prior to being used in an application and must remain magnetized during operation. In addition, they should generate sufficient magnetic flux for a given application. Nevertheless permanent magnets can be demagnetized (discharged of their magnetization) by other magnetic materials in their service vicinity, temperature changes (thermal demagnetization), microstructural degradations and the magnet’s internal demagnetizing field. Therefore a permanent magnet can be qualified based on the properties that measure its ability to withstandmore » demagnetization and to supply sufficient magnetic flux required for a given application. Some of those properties are further discussed below. Additive manufacturing followed by exchange spring magnets will be discussed afterwards.« less

The permanence of mental objects: testing magical thinking on perceived and imaginary realities.

PubMed

Subbotsky, Eugene

2005-03-01

This study tested participants' preparedness to acknowledge that an object could change as a result of magical intervention. Six- and 9-year-old children and adults treated perceived and imagined objects as being equally permanent. Adults treated a fantastic object as significantly less permanent than either perceived or imagined objects. Results were similar when a different type of mental-physical causality--a participant's own wish--was examined. Adults were also tested on the permanence of personally significant imagined objects (participants' images of their future lives). Although almost all participants claimed that they did not believe in magic, in test trials they were not prepared to rule out the possibility that their future lives could be affected by a magical curse. Copyright 2005 APA, all rights reserved.

Motivational interviewing in permanent supportive housing: the role of organizational culture.

PubMed

van den Berk-Clark, Carissa; Patterson Silver Wolf, David A; Ramsey, Alex

2015-07-01

This study evaluated motivational interviewing (MI) in a permanent supportive housing agency. The agency's contradictory social service and business missions resulted in an incompatible organizational culture theorized to diminish MI's effectiveness. A combination of observational, interview, and archival data collected over 3 years were used to examine MI implementation within an incompatible supportive housing agency. Two major themes arose: how MI is used to categorize and change clients in permanent supportive housing and how worker-worker relationships affect MI implementation. The results suggest that within incompatible organizational environments, key elements of effective MI implementation are greatly weakened.

Three-dimensional morphology of the palate in subjects with isolated cleft palate at the stage of permanent dentition.

PubMed

Smahel, Zbynek; Trefný, Pavel; Formánek, Pavel; Müllerová, Ziva; Peterka, Miroslav

2003-11-01

Three-dimensional analysis of palate size and shape in patients with isolated cleft palate at the stage of permanent dentition. Cross-sectional study using Fourier transform profilometry. Twenty-nine randomly selected dental casts of approximately 15-year-old boys with isolated cleft palate and 28 dental casts of normal boys of the same age. All patients were operated on by the same method (pushback and pharyngeal flap surgery) at a mean age of 4.5 years. Data on the palate height in 210 defined locations (pixels). The palate in isolated clefts is narrower throughout its whole extent and lower from the level of the first premolars. The difference, as compared with controls, increases in a posterior direction. At the level of the first molars, palatal height is reduced by one-quarter, the area of the transversal section by more than one-third. The shaping of the palate vault is, on average, symmetrical with a marked interindividual variability. Palatal height does not depend on the width of the dentoalveolar arch, and the height of the primary palate is not reduced. The smaller width and reduced height from the level of the first premolars posteriorly confirm the substantially reduced space available for the tongue in patients with isolated cleft palate. Deviations are on the average symmetrical, and the anterior part of the palate is not shallower.

Perspectives for high-performance permanent magnets: applications, coercivity, and new materials

NASA Astrophysics Data System (ADS)

Hirosawa, Satoshi; Nishino, Masamichi; Miyashita, Seiji

2017-03-01

High-performance permanent magnets are indispensable in the production of high-efficiency motors and generators and ultimately for sustaining the green earth. The central issue of modern permanent magnetism is to realize high coercivity near and above room temperature on marginally hard magnetic materials without relying upon the critical elements such as heavy rare earths by means of nanostructure engineering. Recent investigations based on advanced nanostructure analysis and large-scale first principles calculations have led to significant paradigm shifts in the understandings of coercivity mechanism in Nd-Fe-B permanent magnets, which includes the discovery of the ferromagnetism of the thin (2 nm) intergranular phase surrounding the Nd2Fe14B grains, the occurrence of negative (in-plane) magnetocrystalline anisotropy of Nd ions and some Fe atoms at the interface which degrades coercivity, and visualization of the stochastic behaviors of magnetization in the magnetization reversal process at high temperatures. A major change may occur also in the motor topologies, which is currently overwhelmed by the magnetic flux weakening interior permanent magnet motor type, to other types with variable flux permanent magnet type in some applications to open up a niche for new permanent magnet materials. Keynote talk at 8th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2016), 8-12 November 2016, Ha Long City, Vietnam.

Permanence of agricultural afforestation for carbon sequestration under stylized carbon markets in the U.S.

Treesearch

David Haim; Eric White; Ralph J. Alig

2014-01-01

This paper examines the permanence of agricultural land afforestation under stylized carbon markets at the regional level in the US. Attention is focused on Southern and Midwest regions which historically have experienced a relatively large amount of land-use change between the agriculture and forest sectors. The Forest and Agriculture Sector Optimization Model–...

Does Community and Family Engagement Enhance Permanency for Children in Foster Care? Findings from an Evaluation of the Family-to-Family Initiative

ERIC Educational Resources Information Center

Crampton, David S.; Usher, Charles L.; Wildfire, Judith B.; Webster, Daniel; Cuccaro-Alamin, Stephanie

2011-01-01

There is limited research assessing the effectiveness of family engagement for improving permanency for children. An important challenge is that randomized designs are not feasible for evaluating these practices because effective implementation of family engagement requires systemic change. Findings from a national evaluation are presented to…

"The Piety of Degradation": Kenneth Burke, the Bureau of Social Hygiene, and "Permanence and Change"

ERIC Educational Resources Information Center

Jack, Jordynn

2004-01-01

Kenneth Burke's employment with the Bureau of Social Hygiene informed his rhetorical theory in the 1930s. Between 1926 and 1930, Burke researched criminology and drug addiction and ghostwrote a book for Colonel Arthur Woods, Dangerous Drugs. An investigation of archives indicates that this research left its mark on Burke's Permanence and Change…

[Changes of vascular reactivity and reactive oxygen species in conditions of varying duration of permanent stay in the alienation zone in mice].

PubMed

Tkachenko, M M; Kotsiuruba, A V; Baziliuk, O V; Horot', I V; Sahach, V F

2010-01-01

Peculiarities of changes in the vascular reactivity and in the content of reactive forms of oxygen and stable metabolites of nitric oxide (NO) were studied in the aorta preparations of C57BL/6 and BALB/c mice of the two age groups (6 and 18 mo.), which were born and permanently kept in the Chernobyl alienation zone. The results obtained showed a disturbance of acetylcholine-induced endothelium-dependent reactions of relaxation of smooth muscles of the thoracic aorta. A lower level of NO synthesis and lower level of oxidative arginase metabolism of arginine corresponded to a higher degree of damage of endothelium-dependent reactions of relaxation of the thoracic aorta smooth muscles. A decrease of NO synthesis in conditions of permanent effects of low doses of radiation was conditioned by an increase of generation of reactive forms of oxygen, namely, superoxide and hydroxyl radicals, which might be formed in mitochondria. In conditions of permanent effects of low doses of radiation a lesser level of protein nitrosothilation, same as lesser one of generation of OH-radical, corresponded to a higher level of damage of endothelium-dependent reactions.

Plastic behavior of polycrystalline copper at optical scales of deformation

NASA Astrophysics Data System (ADS)

Domber, Jeanette Leah

Microplasticity is permanent deformation that occurs below the proportional limit of a material. For precision deployable optical spacecraft, it is unknown how microplasticity will affect the performance of the precision structure. An examination of the rolling of thin film optical reflectors indicates a strong dependence of the post-deployed shape on the strain hardening exponent of the material. However, confirmation of the valid extension of the constitutive model used to predict the deployed shape to microscopic strain regimes is necessary. The primary objective of this thesis is threefold: determine the relationship between stress and strain at nano to microstrain levels for representative materials; determine if the relationship between microscopic and macroscopic plastic behavior can be accurately characterized by the Ramberg-Osgood strain hardening constitutive model with a single set of material parameters; and determine if dislocation motion is the root cause of microplastic behavior at room temperature. The test apparatus, with a dynamic force range of 40,000 to 1, measures strains from 0.01 to 1000 parts per million (ppm) of cylindrical amorphous quartz and cold-worked and annealed tempered polycrystalline copper specimen. Elastic behavior in all three materials was consistent with typical values. However, plastic responses were larger than expected. Stresses on the order of 10 to 10,000 kPa (1.45 to 1450 psi) produced permanent strain in all three types of materials ranging from 0.01 to 1 ppm, some of which was attributable to a systematic error in the measurement. Extrapolating macroplastic behavior to lower stress and strain values underestimates the amount of microplasticity observed in the material. Therefore, material property characterization is required at all strain levels that are of concern for a particular application. The similarity in the levels of measured permanent strain for a given stress level between the as-drawn and annealed copper is consistent with the observed dislocation substructure of the two materials, which is also similar. This uniformity indicates that microplastic behavior at room temperature is driven by dislocation glide.

Seasonal variation in wing size and shape between geographic populations of the malaria vector, Anopheles coluzzii in Burkina Faso (West Africa).

PubMed

Hidalgo, Kevin; Dujardin, Jean-Pierre; Mouline, Karine; Dabiré, Roch K; Renault, David; Simard, Frederic

2015-03-01

The mosquito, Anopheles coluzzii is a major vector of human malaria in Africa with widespread distribution throughout the continent. The species hence populates a wide range of environments in contrasted ecological settings often exposed to strong seasonal fluctuations. In the dry savannahs of West Africa, this mosquito population dynamics closely follows the pace of surface water availability: the species pullulates during the rainy season and is able to reproduce throughout the dry season in areas where permanent water bodies are available for breeding. The impact of such environmental fluctuation on mosquito development and the phenotypic quality of emerging adults has however not been addressed in details. Here, we examined and compared phenotypic changes in the duration of pre-imaginal development, body dry mass at emergence and wing size, shape and surface area in young adult females An. coluzzii originated from five distinct geographic locations when they are reared in two contrasting conditions mimicking those experienced by mosquitoes during the rainy season (RS) and at the onset of the dry season (ODS) in Burkina Faso (West Africa). Our results demonstrated strong phenotypic plasticity in all traits, with differences in the magnitude and direction of changes between RS and ODS depending upon the geographic origin, hence the genetic background of the mosquito populations. Highest heterogeneity within population was observed in Bama, where large irrigation schemes allow year-round mosquito breeding. Further studies are needed to explore the adaptive value of such phenotypic plasticity and its relevance for local adaptation in An. coluzzii. Copyright © 2015 Elsevier B.V. All rights reserved.

Dynamics of a class of vortex rings. Ph.D. Thesis - Stanford Univ.

NASA Technical Reports Server (NTRS)

Shariff, Karim; Leonard, Anthony; Ferziger, Joel H.

1989-01-01

The contour dynamics method is extended to vortex rings with vorticity varying linearly from the symmetry axis. An elliptic core model is also developed to explain some of the basic physics. Passage and collisions of two identical rings are studied focusing on core deformation, sound generation and stirring of fluid elements. With respect to core deformation, not only the strain rate but how rapidly it varies is important and accounts for greater susceptibility to vortex tearing than in two dimensions. For slow strain, as a passage interaction is completed and the strain relaxes, the cores return to their original shape while permanent deformations remain for rapidly varying strain. For collisions, if the strain changes slowly the core shapes migrate through a known family of two-dimensional steady vortex pairs up to the limiting member of the family. Thereafter energy conservation does not allow the cores to maintain a constant shape. For rapidly varying strain, core deformation is severe and a head-tail structure in good agreement with experiments is formed. With respect to sound generation, good agreement with the measured acoustic signal for colliding rings is obtained and a feature previously thought to be due to viscous effects is shown to be an effect of inviscid core deformation alone. For passage interactions, a component of high frequency is present. Evidence for the importance of this noise source in jet noise spectra is provided. Finally, processes of fluid engulfment and rejection for an unsteady vortex ring are studied using the stable and unstable manifolds. The unstable manifold shows excellent agreement with flow visualization experiments for leapfrogging rings suggesting that it may be a good tool for numerical flow visualization in other time periodic flows.

Ejaculate fractioning effect on llama sperm head morphometry as assessed by the ISAS(®) CASA system.

PubMed

Soler, C; Sancho, M; García, A; Fuentes, Mc; Núñez, J; Cucho, H

2014-02-01

South American camelid sperm characteristics are poorly known compared with those of other domestic animals. The long-term duration of ejaculation makes difficult to gather all the seminal fluid, implying possible ejaculation portion losses. Thus, the aim of this research was to evaluate the characteristics of the morphology and morphometry of the spermatozoa change during ejaculation. The morphometric characterization was tested on nine specimens of the Lanuda breed, using a special artificial vagina. In five of the animals, a fractioning of the ejaculate was performed by taking samples every 5 min. for a total of 20 min. Air-dried seminal smears were stained with Hemacolor and mounted permanently with Eukitt. Morphometric analysis was carried out with the morphometry module of the ISAS(®) CASA system. Almost 350 cells were analysed per sample, with a total number of 3207 spermatozoa. Mean values were given as follows: length: 5.51 μm; width: 3.38 μm; area: 17.75 μm(2) ; perimeter: 14.8 μm; ellipticity: 0.24; elongation: 0.56; rugosity: 0.87; regularity: 1.07; and shape factor: 1.41. Different animals showed differences in their morphometric values. When we compared the values from different fractions, only two samples showed differences in morphometric parameter values and four samples showed differences in shape parameters. Multivariate analysis allowed the size classification of the cells into three classes and five classes of shapes. The distribution of classes among fractions showed no differences. Despite the individual morphometric differences observed in some fractions, the characteristics of the sperm head morphometry can be considered constant along the ejaculatory period in the llama. © 2013 Blackwell Verlag GmbH.

Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

DOE PAGES

Simos, Nikolaos; Fernandes, S.; Mittig, Wolfgang; ...

2016-10-06

We present ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets that have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiationmore » is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. Lastly, at 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd 2Fe 14B and Sm 2Co 17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.« less

Polymer film-nanoparticle composites as new multimodality, non-migrating breast biopsy markers.

PubMed

Kaplan, Jonah A; Grinstaff, Mark W; Bloch, B Nicolas

2016-03-01

To develop a breast biopsy marker that resists fast and slow migration and has permanent visibility under commonly used imaging modalities. A polymer-nanoparticle composite film was prepared by embedding superparamagnetic iron oxide nanoparticles and a superelastic Nitinol wire within a flexible polyethylene matrix. MRI, mammography, and ultrasound were used to visualize the marker in agar, ex vivo chicken breast, bovine liver, brisket, and biopsy training phantoms. Fast migration caused by the "accordion effect" was quantified after simulated stereotactic, vacuum-assisted core biopsy/marker placement, and centrifugation was used to simulate accelerated long-term (i.e., slow) migration in ex vivo bovine tissue phantoms. Clear marker visualization under MRI, mammography, and ultrasound was observed. After deployment, the marker partially unfolds to give a geometrically constrained structure preventing fast and slow migration. The marker can be deployed through an 11G introducer without fast migration occurring, and shows substantially less slow migration than conventional markers. The polymer-nanoparticle composite biopsy marker is clearly visible on all clinical imaging modalities and does not show substantial migration, which ensures multimodal assessment of the correct spatial information of the biopsy site, allowing for more accurate diagnosis and treatment planning and improved breast cancer patient care. Polymer-nanoparticle composite biopsy markers are visualized using ultrasound, MRI, and mammography. Embedded iron oxide nanoparticles provide tuneable contrast for MRI visualization. Permanent ultrasound visibility is achieved with a non-biodegradable polymer having a distinct ultrasound signal. Flexible polymer-based biopsy markers undergo shape change upon deployment to minimize migration. Non-migrating multimodal markers will help improve accuracy of pre/post-treatment planning studies.

Development of an omni-directional shear horizontal mode magnetostrictive patch transducer

NASA Astrophysics Data System (ADS)

Liu, Zenghua; Hu, Yanan; Xie, Muwen; Fan, Junwei; He, Cunfu; Wu, Bin

2018-04-01

The fundamental shear horizontal wave, SH0 mode, has great potential in defect detection and on-line monitoring with large scale and high efficiency in plate-like structures because of its non-dispersive characteristics. Aiming at consistently exciting single SH0 mode in plate-like structures, an omni-directional shear horizontal mode magnetostrictive patch transducer (OSHM-MPT) is developed on the basis of magnetostrictive effect. It consists of four fan-shaped array elements and corresponding plane solenoid array (PSA) coils, four fan-shaped permanent magnets and a circular nickel patch. The experimental results verify that the developed transducer can effectively produce the single SH0 mode in an aluminum plate. The frequency response characteristics of this developed transducer are tested. The results demonstrate that the proposed OSHM-MPT has a center frequency of 300kHz related to the distance between adjacent arc-shaped steps of the PSA coils. Furthermore, omni-directivity of this developed transducer is tested. The results demonstrate that the developed transducer has a high omnidirectional consistency.

An Analysis of the Navy’s Permanent Change of Station Planning Process and Move Forecasting Models

DTIC Science & Technology

1991-12-01

AD-A246 182 INAVAL ruSTGRADUATE SCHOOL Monterey, California DTI V ’Ift E S’ LECTE , ’FEB 2 A1g99 THESIS AN ANALYSIS OF THE NAVY’S PERMANENT CHANGE OF...the requirements for the degree of MASTER OF SCIENCE IN MANPOWER MANAGEMENT from the NAVAL POSTGRADUATE SCHOOL December, 1991 Author: 6cA )/C JAa is/lv...wilianm C. McQuilkin Approved by: Stehen MehyThesis -Advisor Thomas P. Moore, Thesis Co-Advisor David R i Department of Adminis tive Sciences ABSTRACT

Development of Permanent Magnet Synchronous Motor Control System for the Traction Purpose of the Gauge Changing Train

NASA Astrophysics Data System (ADS)

Kondo, Keiichiro; Hata, Hiroshi; Yuki, Kazuaki; Naganuma, Katsunori; Matsuoka, Koichi; Hasebe, Toshio

This paper is aimed at providing the designing method of a permanent magnet synchronous motor (PMSM) control system for the high-speed and the single-phase AC powered Gauge Changing Train (GCT). The state-of-the-art electrical motive unit is equipped with downsized direct drive type PMSMs for the simplified gauge changeable truck. Due to the feeding the AC single phase power, we propose a beat-less control for PMSMs. We verify the development results of designing procedures by the experimental results of operation on a high-speed test line in Colorado, USA.

Evaluating child welfare policies with decision-analytic simulation models.

PubMed

Goldhaber-Fiebert, Jeremy D; Bailey, Stephanie L; Hurlburt, Michael S; Zhang, Jinjin; Snowden, Lonnie R; Wulczyn, Fred; Landsverk, John; Horwitz, Sarah M

2012-11-01

The objective was to demonstrate decision-analytic modeling in support of Child Welfare policymakers considering implementing evidence-based interventions. Outcomes included permanency (e.g., adoptions) and stability (e.g., foster placement changes). Analyses of a randomized trial of KEEP-a foster parenting intervention-and NSCAW-1 estimated placement change rates and KEEP's effects. A microsimulation model generalized these findings to other Child Welfare systems. The model projected that KEEP could increase permanency and stability, identifying strategies targeting higher-risk children and geographical regions that achieve benefits efficiently. Decision-analytic models enable planners to gauge the value of potential implementations.

Finite element model of size, shape and blood pressure on rupture of intracranial saccular aneurysms

NASA Astrophysics Data System (ADS)

Rica Nabong, Jennica; David, Guido

2017-10-01

Rupture of intracranial saccular aneurysms is a primary concern for neurologists and patients because it leads to stroke and permanent disability. This paper examines the role of blood pressure, in connection with size of and wall thickness, in the rupture of saccular aneurysms. A bulb-shaped geometry of a saccular aneurysm is obtained from angiographic images of a patient and modeled using Finite Elements based on the principle of virtual work under the Fung stress-strain relationship. The numerical model is subjected to varying levels of systolic blood pressure. Rupture is assumed to occur when the wall stress exceeded its mechanical strength. The results show which sizes of this class of aneurysms are at high risk of rupture for varying levels of blood pressure.

Rotating Casimir systems: Magnetic-field-enhanced perpetual motion, possible realization in doped nanotubes, and laws of thermodynamics

NASA Astrophysics Data System (ADS)

Chernodub, M. N.

2013-01-01

Recently, we have demonstrated that for a certain class of Casimir-type systems (“devices”) the energy of zero-point vacuum fluctuations reaches its global minimum when the device rotates about a certain axis rather than remains static. This rotational vacuum effect may lead to the emergence of permanently rotating objects provided the negative rotational energy of zero-point fluctuations cancels the positive rotational energy of the device itself. In this paper, we show that for massless electrically charged particles the rotational vacuum effect should be drastically (astronomically) enhanced in the presence of a magnetic field. As an illustration, we show that in a background of experimentally available magnetic fields the zero-point energy of massless excitations in rotating torus-shaped doped carbon nanotubes may indeed overwhelm the classical energy of rotation for certain angular frequencies so that the permanently rotating state is energetically favored. The suggested “zero-point-driven” devices—which have no internally moving parts—correspond to a perpetuum mobile of a new, fourth kind: They do not produce any work despite the fact that their equilibrium (ground) state corresponds to a permanent rotation even in the presence of an external environment. We show that our proposal is consistent with the laws of thermodynamics.

Variable permanent mandibular first molar: Review of literature

PubMed Central

Ballullaya, Srinidhi V; Vemuri, Sayesh; Kumar, Pabbati Ravi

2013-01-01

Introduction: The success of root canal therapy depends on the locations of all the canals, thourough debridement and proper sealing. At times the clinicians are challenged with variations in morphology of root canal. This review article attempts to list out all the variations of permanent mandibular first molar published so for in the literature. Materials and Methods: An exhaustive search was undertaken using PUBMED database to identify published literature from 1900 to 2010 relating to the root canal morphology of permanent first molar by using key words. The selected artcles were obtained and reviewed. Results: Total ninty seven articles were selected out of which 50 were original article and forty seven were case reports. The incidence of third canal in mesial root was 0.95% to 15%. The incidence of three rooted mandibular first molar was 3% to 33%. Only ninety cases reported with c-shape canal configuration. Incidence of Taurodintism without congenital disorder was very rare. Conclusion: The root canal treatment requires proper knowlegde of variations in root canal morphology in order to recognise, disinfect and seal all portal of exit. This can be accomplished with proper diagnosis using newer modes, modification in access preparation, use of operating microscope, enhanced methods of disinfecting and sealing of all canals. PMID:23716959

Conceptual Study of Permanent Magnet Machine Ship Propulsion Systems

DTIC Science & Technology

1977-12-01

cycloconverter subsystem is designed using advanced thyristors and can be either water or air cooled. The machine-cycloconverter, many-phase or parallel...Turnb, Phase, Poles, Air Gap ................................. 3-9 3-5 Machine Characteristics Versus Number of Poles (large machine, 40 000 hp). Poles...cylindrical permanent magnet generator forces the power conditioner to provide for both frequency change and voltage control. The complexity of this dual

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.

Motivational Interviewing in permanent supportive housing: The role of organizational culture

PubMed Central

van den Berk-Clark, Carissa; Patterson Silver Wolf (Adelv unegv Waya), David A.; Ramsey, Alex

2014-01-01

This study evaluated motivational interviewing (MI) in a permanent supportive housing agency. The agency’s contradictory social service and business missions resulted in an incompatible organizational culture theorized to diminish MI’s effectiveness. A combination of observational, interview, and archival data collected over 3 years were used to examine MI implementation within an incompatible supportive housing agency. Two major themes arose: how MI is used to categorize and change clients in permanent supportive housing and how worker–worker relationships affect MI implementation. The results suggest that within incompatible organizational environments, key elements of effective MI implementation are greatly weakened. PMID:25129815

[Immobilization and skeletal system of the human body].

PubMed

Kisała, Aleksander; Pluskiewicz, Wojciech

2015-01-01

Shaping the process of evolution musculoskeletal and nervous systems in animals has allowed these organisms steady increase mobility and mastery of new environments to life. Movement is the essence of life and health. But health is not a permanent condition. Its absence often results in limited mobility of the body. The aim of this study is to assess the impact of immobilization on the state of the skeletal system and the evaluation of the effectiveness of various measures to reduce this impact.

Dynamical Evolution and Spin-Orbit Resonances of Potentially Habitable Exoplanets. The Case of GJ 667C

DTIC Science & Technology

2014-01-10

observed trend is consistent with a gravitational acceleration exerted by the inner pair of stars (A and B) in this multiple star system. Our planet...the other hand, the observed trend in the RV of the C component can be caused by its orbital acceleration around the AB pair. 3. LONG-TERM EVOLUTION...polar torque acting on a rotating planet is the sum of the gravitational torque, caused by the triaxial permanent shape and the corresponding quadrupole

Method for determining the hardness of strain hardening articles of tungsten-nickel-iron alloy

DOEpatents

Wallace, Steven A.

1984-01-01

The present invention is directed to a rapid nondestructive method for determining the extent of strain hardening in an article of tungsten-nickel-iron alloy. The method comprises saturating the article with a magnetic field from a permanent magnet, measuring the magnetic flux emanating from the article, comparing the measurements of the magnetic flux emanating from the article with measured magnetic fluxes from similarly shaped standards of the alloy with known amounts of strain hardening to determine the hardness.

Growth and development of permanent teeth germ of transplacental Yu-Cheng babies in Taiwan

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

Lan, Shoujen; Yen, Yeayin; Ko, Yingchin

This paper is intended to present a study of transplacental Yu-Cheng babies in Taiwan. The focus of the study is to demonstrate how a contaminated food source can affect the growth and development of permanent teeth germ in children. A sporadic outbreak of a peculiar skin disease was reported in Japan in October of 1968. An epidemiological study revealed the outbreak of this disease was caused by contaminated Kanemi rice oil. This episode of rice oil poisoned with polychlorinated biphenyls (PCB) was the first reported outbreak of PCB poisoning in the world. A second episode occurred in central Taiwan elevenmore » years after the Japanese episode. Registered data from the Taiwan Provincial Government Health Department reported 1,843 cases in 1980. Of this group, more than 800 women were child-bearing age and most of these women would or soon would be married and pregnant. The offsprings of these women were in danger, because it has been proven that PCB intoxication could affect the fetus. These babies, only contaminated through the placenta, are called PCB transplacental Yusho babies in Japan and PCB transplacental Yu-Cheng babies in Taiwan. Babies with PCB poisoning could have Fetal PCB syndrome (FPS) and may have retarded eruption of permanent teeth and other anomalies such as reduced numbers of teeth and abnormal shaped roots. The study of transplacental Yu-Cheng babies is an important public health issue for Taiwan. Although there may be other issues, this study focuses only on the growth and development of permanent teeth of those babies affected by PCB transplacental contamination.« less

Phytoplankton responses to temperature increases are constrained by abiotic conditions and community composition.

PubMed

Striebel, Maren; Schabhüttl, Stefanie; Hodapp, Dorothee; Hingsamer, Peter; Hillebrand, Helmut

2016-11-01

Effects of temperature changes on phytoplankton communities seem to be highly context-specific, but few studies have analyzed whether this context specificity depends on differences in the abiotic conditions or in species composition between studies. We present an experiment that allows disentangling the contribution of abiotic and biotic differences in shaping the response to two aspects of temperature change: permanent increase of mean temperature versus pulse disturbance in form of a heat wave. We used natural communities from six different sites of a floodplain system as well as artificially mixed communities from laboratory cultures and grew both, artificial and natural communities, in water from the six different floodplain lakes (sites). All 12 contexts (2 communities × 6 sites) were first exposed to three different temperature levels (12, 18, 24 °C, respectively) and afterward to temperature pulses (4 °C increase for 7 h day(-1)). Temperature-dependent changes in biomass and community composition depended on the initial composition of phytoplankton communities. Abiotic conditions had a major effect on biomass of phytoplankton communities exposed to different temperature conditions, however, the effect of biotic and abiotic conditions together was even more pronounced. Additionally, phytoplankton community responses to pulse temperature effects depended on the warming history. By disentangling abiotic and biotic effects, our study shows that temperature-dependent effects on phytoplankton communities depend on both, biotic and abiotic constraints.

Neighborhood Environments and Physical Activity: A Longitudinal Study of Adolescents in a Natural Experiment.

PubMed

Nicosia, Nancy; Datar, Ashlesha

2018-05-01

Experimental and quasi-experimental evidence on the relationship between adolescents' physical activity and their physical activity environments is scarce. This study provides natural experimental evidence using within-person longitudinal variation in physical activity environments resulting from the compulsory re-assignment of military families to new installations, termed permanent changes of station. Adolescents in Army families (N=749) reported usual weekly minutes of moderate and vigorous physical activity in 2013-2015. Objective measures of the physical activity environment, including the number of fitness and recreation facilities within 2 miles, were constructed for adolescents' neighborhoods using GIS methods. In 2017, individual-level fixed-effects models with and without a comparison group estimated the relationship between usual weekly minutes of physical activity and physical activity environments among permanent changes of station movers using within-person variation. Increases in opportunities for physical activity were significantly and positively associated with increases in total (p<0.05) and vigorous physical activity (p<0.05) among adolescents who experienced permanent changes of station moves. The relationships were statistically significant for permanent changes of station movers living off-installation (p<0.05) and hence subject to greater variation in physical activity environments and those with more time to adjust to their new environments (p<0.05). Significant findings persisted when broader measures of physical activity environments were utilized. The decline in physical activity and alarming obesity levels during adolescence suggest that this age may represent an important opportunity to address the obesity epidemic. This study provides evidence that increasing opportunities for physical activity may be an important pathway to improving their levels of physical activity and, consequently, obesity. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Effects of heat treatment on shape-setting and non-linearmechanical properties of Nitinol stent

NASA Astrophysics Data System (ADS)

Liu, Xiaopeng; Wang, Yinong; Qi, Min; Yang, Dazhi

2007-07-01

NiTi shape memory alloy is a temperature sensitive material with non-linear mechanical properties and good biocompatibility, which can be used for medical devices such as stent, catheter guide wire and orthodontic wire. The majority of nitinol stents are of the self-expanding type basing on the superelasticity. Nitinol stents are shape set into the open condition and compressed and inserted into the delivery catheter. Additional the shape-setting treatment can be used as a tool to accurately tune the transformation temperatures and mechanical properties. In this study, different heat treatments have been performed on the Ti-50.7at%Ni alloy wires. And results of shape-setting, austenite transformation finish temperature and non-linear mechanical property of NiTi shape memory alloy at body temperature have been investigated. The experimental results show that the proper shape-setting temperature should be chosen between 450-550 °C. And the shape-setting results were stabilization when the NiTi wires were constrain-treated at 500 and 550°C and ageing time longer than 10 minutes. The austenite finish temperatures increased with ageing time and increased first and then decreased with ageing temperature. The peak values were obtained at 400°C. When the heat treatments was performed at the same temperature, both the upper plateau stresses and lower plateau stresses decreased with the ageing time. Most of treated nitinol wires owned good recovery ability at body temperature and the permanent sets were less than 0.05% when short time ageing treatment was performed at 500°C.

Shape memory alloy smart knee spacer to enhance knee functionality: model design and finite element analysis.

PubMed

Gautam, Arvind; Rani, A Bhargavi; Callejas, Miguel A; Acharyya, Swati Ghosh; Acharyya, Amit; Biswas, Dwaipayan; Bhandari, Vasundhra; Sharma, Paresh; Naik, Ganesh R

2016-08-01

In this paper we introduce Shape Memory Alloy (SMA) for designing the tibial part of Total Knee Arthroplasty (TKA) by exploiting the shape-memory and pseudo-elasticity property of the SMA (e.g. NiTi). This would eliminate the drawbacks of the state-of-the art PMMA based knee-spacer including fracture, sustainability, dislocation, tilting, translation and subluxation for tackling the Osteoarthritis especially for the aged people of 45-plus or the athletes. In this paper a Computer Aided Design (CAD) model using SolidWorks for the knee-spacer is presented based on the proposed SMA adopting the state-of-the art industry-standard geometry that is used in the PMMA based spacer design. Subsequently Ansys based Finite Element Analysis is carried out to measure and compare the performance between the proposed SMA based model with the state-of-the art PMMA ones. 81% more bending is noticed in the PMMA based spacer compared to the proposed SMA that would eventually cause fracture and tilting or translation of spacer. Permanent shape deformation of approximately 58.75% in PMMA based spacer is observed compared to recoverable 11% deformation in SMA when same load is applied on both separately.

14 CFR 47.45 - Change of address.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION Certificates of Aircraft Registration § 47.45 Change of address. Within 30 days after any change in his permanent mailing address, the holder of a Certificate of Aircraft Registration for an...

Permanent foresty plots: a potentially valuable teaching resource in undergraduate biology porgrams for the Caribbean

Treesearch

H. Valles; C.M.S. Carrington

2016-01-01

There has been a recent proposal to change the way that biology is taught and learned in undergraduate biology programs in the USA so that students develop a better understanding of science and the natural world. Here, we use this new, recommended teaching– learning framework to assert that permanent forestry plots could be a valuable tool to help develop biology...

Forest structure and tree recruitment changes on a permanent historical Cinder Hills plot over a 130-Year Period

Treesearch

Jacob H. Dyer; Andrew J. Sanchez Meador; Margaret M. Moore; Jonathan D. Bakker

2008-01-01

We examined forest structure, tree recruitment, and spatial pattern over a 130-year period on cinder soils in northern Arizona. Data were collected from a 3.24 ha permanent, stem-mapped plot established in 1909. This site is unique in that it represents ponderosa pine (Pinus ponderosa Laws. var. scopulorum Engelm.) growing on black cinder soils, which are of limited...

Micro-computed tomographic analysis of progression of artificial enamel lesions in primary and permanent teeth after resin infiltration.

PubMed

Ozgul, Betul Memis; Orhan, Kaan; Oz, Firdevs Tulga

2015-09-01

We investigated inhibition of lesion progression in artificial enamel lesions. Lesions were created on primary and permanent anterior teeth (n = 10 each) and were divided randomly into two groups with two windows: Group 1 (window A: resin infiltration; window B: negative control) and Group 2 (window A: resin infiltration + fluoride varnish; window B: fluoride varnish). After pH cycling, micro-computed tomography was used to analyze progression of lesion depth and changes in mineral density. Resin infiltration and resin infiltration + fluoride varnish significantly inhibited progression of lesion depth in primary teeth (P < 0.05). Inhibition of lesion depth progression in permanent teeth was significantly greater after treatment with resin infiltration + fluoride varnish than in the negative control (P < 0.05). Change in mineral density was smaller in the resin infiltration and resin infiltration + fluoride varnish groups; however, the difference was not significant for either group (P > 0.05). Resin infiltration is a promising method of inhibiting progression of caries lesions.

Environmental change and the conversion of permanently frozen ground to wetlands

NASA Astrophysics Data System (ADS)

Neumann, R. B.; Moorberg, C.; Turner, J.; Wong, A.; Waldrop, M. P.; Euskirchen, E. S.; Edgar, C.; Turetsky, M. R.

2017-12-01

Much of the land around the arctic is permanently frozen, even in the summer. However, because the world is getting warmer, this frozen ground, known as permafrost, is thawing. When permafrost thaws, the ground collapses and sinks, and often a wetland forms within the collapsed area. This conversion of a permanently frozen landscape to a wetland changes the exchange of greenhouse gases between the land and atmosphere, which can, in turn, impact global temperatures and environmental conditions. Wetlands pull carbon dioxide out of the atmosphere because they support the growth of many plants. This uptake of atmospheric carbon dioxide by wetlands helps reduce global warming. However, wetlands also release methane into the atmosphere, which is a potent greenhouse gas — more potent than carbon dioxide. The net effect on global temperatures and environmental conditions depends on the balance between wetland uptake of atmospheric carbon dioxide and release of methane. We are measuring the exchange of these two greenhouse gases between the land and atmosphere in a wetland that formed after permafrost thawed so we can know how global temperatures and environmental conditions will change as northern landscapes continue to thaw.

Study on optimal design of 210kW traction IPMSM considering thermal demagnetization characteristics

NASA Astrophysics Data System (ADS)

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

2018-04-01

This study analyses the permanent magnet (PM) used in the rotor of an interior permanent magnet synchronous motor (IPMSM) used for driving an electric railway vehicle (ERV) in the context of controllable shape, temperature, and external magnetic field. The positioning of the inserted magnets is a degree of freedom in the design of such machines. This paper describes a preliminary analysis using parametric finite-element method performed with the aim of achieving an effective design. Next, features of the experimental design, based on methods such as the central-composition method, Box-Behnken and Taguchi method, are explored to optimise the shape of the high power density. The results are used to produce an optimal design for IPMSMs, with design errors minimized using Maxwell 2D, a commercial program. Furthermore, the demagnetization process is analysed based on the magnetization and demagnetization theory for PM materials in computer simulation. The result of the analysis can be used to calculate the magnetization and demagnetization phenomenon according to the input B-H curve. This paper presents the conditions for demagnetization by the external magnetic field in the driving and stopped states, and proposes a simulation method that can analyse demagnetization phenomena according to each condition and design the IPMSM that maximizes efficiency and torque characteristics. Finally, operational characteristics are analysed in terms of the operation patterns of railway vehicles, and control conditions are deduced to achieve maximum efficiency in all sections. This was experimentally verified.

Modeling tropical land-use and land-cover change related to sugarcane crops using remote sensing and soft computing techniques

NASA Astrophysics Data System (ADS)

Vicente, L. E.; Koga-Vicente, A.; Friedel, M. J.; Zullo, J.; Victoria, D.; Gomes, D.; Bayma, G.

2013-12-01

Agriculture is closely related to land-use/cover changes (LUCC). The increase in demand for ethanol necessitates the expansion of areas occupied by corn and sugar cane. In São Paulo state, the conversion of this land raises concern for impacts on food security, such as the decrease in traditional food crop production areas. We used remote sensing data to train and evaluate future land-cover scenarios using a machine-learning algorithm. The land cover classification procedure was based on Landsat 5 TM images, obtained from the Global Land Survey, covering three time periods over twenty years (1990 - 2010). Landsat images were segmented into homogeneous objects, which represent areas on the ground with similar spatial and spectral characteristics. These objects are related to the distinct land cover types that occur in each municipality. Based on the object shape, texture and spectral characteristics, land use/cover was visually identified, considering the following classes: sugarcane plantations, pasture lands, natural cover, forest plantation, permanent crop, short cycle crop, water bodies and urban areas. Results for the western regions of São Paulo state indicate that sugarcane crop area advanced mostly upon pasture areas with few areas of food crops being replaced by sugarcane.

Acute myocardial infarction during l-thyroxine therapy in a patient with intermittent changing axis deviation, permanent atrial fibrillation and without significant coronary stenoses.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-01-07

It has been rarely reported intermittent changing axis deviation also occurs during atrial fibrillation. Intermittent changing axis deviation during acute myocardial infarction and changing axis deviation associated with atrial fibrillation and acute myocardial infarction too have been also rarely reported. It has also been reported acute myocardial infarction during l-thyroxine substitution therapy in a patient with elevated levels of free triiodothyronine and without significant coronary artery stenoses. An acute myocardial infarction due to coronary spasm associated with l-thyroxine therapy has also been reported too. We present a case of changing axis deviation during acute myocardial infarction in a 56-year-old Italian woman with permanent atrial fibrillation and l-thyroxine therapy and without significant coronary stenoses. Also this case focuses attention on changing axis deviation in the presence of atrial fibrillation during acute myocardial infarction and on the possible development of acute myocardial infarction without significant coronary stenoses associated with l-thyroxine therapy.

Advanced evacuated tube collectors

NASA Astrophysics Data System (ADS)

Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

1985-04-01

The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

Multi-Frequency Microwaves Plasma Production for Active Profile Control of Ion Beams on a Large Bore ECR Ion Source with Permanent Magnets

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

Sakamoto, Naoki; Kato, Yushi; Kiriyama, Ryutaro

2011-01-07

A new concept on magnetic field of plasma production and confinement by using permanent magnets, i.e. cylindrically comb-shaped magnets, has been proposed to enhance efficiency of an electron cyclotron resonance (ECR) plasma for broad and dense ion beam source under the low pressure and also the low microwave power. The resonance zones corresponding to the fundamental ECR for 2.45 GHz and 11-13 GHz frequency are constructed at different positions. The profiles of the plasma parameters in the ECR ion source are different from each frequency of microwave. Large bore extractor is set at the opposite side against the microwave feeds.more » It is found that differences of their profiles also appear at those of ion beam profiles. We conducted to launch simultaneously multiplex frequency microwaves controlled individually, and tried to control the profiles of the plasma parameters and then those of extracted ion beam.« less

Investigations of the emittance and brightness of ion beams from an electron beam ion source of the Dresden EBIS type.

PubMed

Silze, Alexandra; Ritter, Erik; Zschornack, Günter; Schwan, Andreas; Ullmann, Falk

2010-02-01

We have characterized ion beams extracted from the Dresden EBIS-A, a compact room-temperature electron beam ion source (EBIS) with a permanent magnet system for electron beam compression, using a pepper-pot emittance meter. The EBIS-A is the precursor to the Dresden EBIS-SC in which the permanent magnets have been replaced by superconducting solenoids for the use of the source in high-ion-current applications such as heavy-ion cancer therapy. Beam emittance and brightness values were calculated from data sets acquired for a variety of source parameters, in leaky as well as pulsed ion extraction mode. With box shaped pulses of C(4+) ions at an energy of 39 keV root mean square emittances of 1-4 mm mrad and a brightness of 10 nA mm(-2) mrad(-2) were achieved. The results meet the expectations for high quality ion beams generated by an electron beam ion source.

Rapid Assessment of the Ce-Co-Fe-Cu System for Permanent Magnetic Applications

NASA Astrophysics Data System (ADS)

Meng, F.; Chaudhary, R. P.; Gandha, K.; Nlebedim, I. C.; Palasyuk, A.; Simsek, E.; Kramer, M. J.; Ott, R. T.

2018-06-01

This work focuses on the rapid synthesis and characterization of quaternary Ce(CoFeCu)5 alloy libraries to assess their potential viability as permanent magnets. Arrays of bulk specimens with controlled compositions were synthesized via laser engineered net shaping (LENS) by feeding different ratios of alloy powders into a melt pool created by a laser. Based on the assessment of the magnetic properties of the LENS printed samples, arc-melted and cast ingots were prepared with varying Fe (5-20 at.%) and Co (60-45 at.%) compositions while maintaining constant Ce (16 at.%) and Cu (19 at.%) content. The evolution of the microstructure and phases with varying chemical compositions and their dependence on magnetic properties are analyzed in as-cast and heat-treated samples. In both the LENS printed and cast samples, we find the best magnetic properties correspond to a predominantly single-phase Ce(CoFeCu)5 microstructure in which high coercivity ( H c > 10 kOe) can be achieved without any microstructural refinement.

Tessellated permanent magnet circuits for flow-through, open gradient separations of weakly magnetic materials

PubMed Central

Moore, Lee R.; Williams, P. Stephen; Chalmers, Jeffrey J.; Zborowski, Maciej

2017-01-01

Emerging microfluidic-based cell assays favor label-free red blood cell (RBC) depletion. Magnetic separation of RBC is possible because of the paramagnetism of deoxygenated hemoglobin but the process is slow for open-gradient field configurations. In order to increase the throughput, periodic arrangements of the unit magnets were considered, consisting of commercially available Nd-Fe-B permanent magnets and soft steel flux return pieces. The magnet design is uniquely suitable for multiplexing by magnet tessellation, here meaning the tiling of the magnet assembly cross-sectional plane by periodic repetition of the magnet and the flow channel shapes. The periodic pattern of magnet magnetizations allows a reduction of the magnetic material per channel with minimal distortion of the field cylindrical symmetry inside the magnet apertures. A number of such magnet patterns are investigated for separator performance, size and economy with the goal of designing an open-gradient magnetic separator capable of reducing the RBC number concentration a hundred-fold in 1 mL whole blood per hour. PMID:29104346

Tessellated permanent magnet circuits for flow-through, open gradient separations of weakly magnetic materials.

PubMed

Moore, Lee R; Williams, P Stephen; Chalmers, Jeffrey J; Zborowski, Maciej

2017-04-01

Emerging microfluidic-based cell assays favor label-free red blood cell (RBC) depletion. Magnetic separation of RBC is possible because of the paramagnetism of deoxygenated hemoglobin but the process is slow for open-gradient field configurations. In order to increase the throughput, periodic arrangements of the unit magnets were considered, consisting of commercially available Nd-Fe-B permanent magnets and soft steel flux return pieces. The magnet design is uniquely suitable for multiplexing by magnet tessellation, here meaning the tiling of the magnet assembly cross-sectional plane by periodic repetition of the magnet and the flow channel shapes. The periodic pattern of magnet magnetizations allows a reduction of the magnetic material per channel with minimal distortion of the field cylindrical symmetry inside the magnet apertures. A number of such magnet patterns are investigated for separator performance, size and economy with the goal of designing an open-gradient magnetic separator capable of reducing the RBC number concentration a hundred-fold in 1 mL whole blood per hour.

Endodontic Management of the Three-Rooted Mandibular First Permanent Molar: a Case Report.

PubMed

Štamfelj, Iztok

2014-09-01

The distal root of the mandibular first permanent molar (MFPM) contains one or two canals. More rarely, the second/third distal canal is found in a separate root in a distolingual (DL) position - a radix entomolaris (RE). In Caucasians, this occurs in less than 4% of cases, but it is equally important to be aware of this possibility. Careful examination of the preoperative periapical radiographs (orthoradial and mesially angled) and inspection of the pulp chamber floor during endodontic management may indicate that this radicular variant is present. RE's lingual inclination and buccolingual curvature must be taken into account during cleaning and shaping of the canal within this root to avoid procedural errors, such as straightening and ledging of the root canal, perforation or instrument fracture. The aim of the present paper was to discuss a case report of a young patient, referred to an endodontic office after a ledge was created by inappropriate instrumentation of a buccolingually curved RE canal.

Rapid Assessment of the Ce-Co-Fe-Cu System for Permanent Magnetic Applications

NASA Astrophysics Data System (ADS)

Meng, F.; Chaudhary, R. P.; Gandha, K.; Nlebedim, I. C.; Palasyuk, A.; Simsek, E.; Kramer, M. J.; Ott, R. T.

2018-04-01

This work focuses on the rapid synthesis and characterization of quaternary Ce(CoFeCu)5 alloy libraries to assess their potential viability as permanent magnets. Arrays of bulk specimens with controlled compositions were synthesized via laser engineered net shaping (LENS) by feeding different ratios of alloy powders into a melt pool created by a laser. Based on the assessment of the magnetic properties of the LENS printed samples, arc-melted and cast ingots were prepared with varying Fe (5-20 at.%) and Co (60-45 at.%) compositions while maintaining constant Ce (16 at.%) and Cu (19 at.%) content. The evolution of the microstructure and phases with varying chemical compositions and their dependence on magnetic properties are analyzed in as-cast and heat-treated samples. In both the LENS printed and cast samples, we find the best magnetic properties correspond to a predominantly single-phase Ce(CoFeCu)5 microstructure in which high coercivity (H c > 10 kOe) can be achieved without any microstructural refinement.

Altered dynamics of broad-leaved tree species in a Chinese subtropical montane mixed forest: the role of an anomalous extreme 2008 ice storm episode.

PubMed

Ge, Jielin; Xiong, Gaoming; Wang, Zhixian; Zhang, Mi; Zhao, Changming; Shen, Guozhen; Xu, Wenting; Xie, Zongqiang

2015-04-01

Extreme climatic events can trigger gradual or abrupt shifts in forest ecosystems via the reduction or elimination of foundation species. However, the impacts of these events on foundation species' demography and forest dynamics remain poorly understood. Here we quantified dynamics for both evergreen and deciduous broad-leaved species groups, utilizing a monitoring permanent plot in a subtropical montane mixed forest in central China from 2001 to 2010 with particular relevance to the anomalous 2008 ice storm episode. We found that both species groups showed limited floristic alterations over the study period. For each species group, size distribution of dead individuals approximated a roughly irregular and flat shape prior to the ice storm and resembled an inverse J-shaped distribution after the ice storm. Furthermore, patterns of mortality and recruitment displayed disequilibrium behaviors with mortality exceeding recruitment for both species groups following the ice storm. Deciduous broad-leaved species group accelerated overall diameter growth, but the ice storm reduced evergreen small-sized diameter growth. We concluded that evergreen broad-leaved species were more susceptible to ice storms than deciduous broad-leaved species, and ice storm events, which may become more frequent with climate change, might potentially threaten the perpetuity of evergreen-dominated broad-leaved forests in this subtropical region in the long term. These results underscore the importance of long-term monitoring that is indispensible to elucidate causal links between forest dynamics and climatic perturbations.

Surface patterning of nanoparticles with polymer patches

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

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties.more » At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. We demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. Furthermore, these patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.« less

Surface patterning of nanoparticles with polymer patches

DOE PAGES

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; ...

2016-08-24

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties.more » At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. We demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. Furthermore, these patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.« less

Surface patterning of nanoparticles with polymer patches

NASA Astrophysics Data System (ADS)

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; Klinkova, Anna; Larin, Egor M.; Querejeta-Fernández, Ana; Han, Lili; Xin, Huolin L.; Gang, Oleg; Zhulina, Ekaterina B.; Rubinstein, Michael; Kumacheva, Eugenia

2016-10-01

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient, but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties. At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles, and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. Here we demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. These patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.

Altered dynamics of broad-leaved tree species in a Chinese subtropical montane mixed forest: the role of an anomalous extreme 2008 ice storm episode

PubMed Central

Ge, Jielin; Xiong, Gaoming; Wang, Zhixian; Zhang, Mi; Zhao, Changming; Shen, Guozhen; Xu, Wenting; Xie, Zongqiang

2015-01-01

Extreme climatic events can trigger gradual or abrupt shifts in forest ecosystems via the reduction or elimination of foundation species. However, the impacts of these events on foundation species' demography and forest dynamics remain poorly understood. Here we quantified dynamics for both evergreen and deciduous broad-leaved species groups, utilizing a monitoring permanent plot in a subtropical montane mixed forest in central China from 2001 to 2010 with particular relevance to the anomalous 2008 ice storm episode. We found that both species groups showed limited floristic alterations over the study period. For each species group, size distribution of dead individuals approximated a roughly irregular and flat shape prior to the ice storm and resembled an inverse J-shaped distribution after the ice storm. Furthermore, patterns of mortality and recruitment displayed disequilibrium behaviors with mortality exceeding recruitment for both species groups following the ice storm. Deciduous broad-leaved species group accelerated overall diameter growth, but the ice storm reduced evergreen small-sized diameter growth. We concluded that evergreen broad-leaved species were more susceptible to ice storms than deciduous broad-leaved species, and ice storm events, which may become more frequent with climate change, might potentially threaten the perpetuity of evergreen-dominated broad-leaved forests in this subtropical region in the long term. These results underscore the importance of long-term monitoring that is indispensible to elucidate causal links between forest dynamics and climatic perturbations. PMID:25897387

Principal component analysis of three-dimensional face shape: Identifying shape features that change with age.

PubMed

Kurosumi, M; Mizukoshi, K

2018-05-01

The types of shape feature that constitutes a face have not been comprehensively established, and most previous studies of age-related changes in facial shape have focused on individual characteristics, such as wrinkle, sagging skin, etc. In this study, we quantitatively measured differences in face shape between individuals and investigated how shape features changed with age. We analyzed three-dimensionally the faces of 280 Japanese women aged 20-69 years and used principal component analysis to establish the shape features that characterized individual differences. We also evaluated the relationships between each feature and age, clarifying the shape features characteristic of different age groups. Changes in facial shape in middle age were a decreased volume of the upper face and increased volume of the whole cheeks and around the chin. Changes in older people were an increased volume of the lower cheeks and around the chin, sagging skin, and jaw distortion. Principal component analysis was effective for identifying facial shape features that represent individual and age-related differences. This method allowed straightforward measurements, such as the increase or decrease in cheeks caused by soft tissue changes or skeletal-based changes to the forehead or jaw, simply by acquiring three-dimensional facial images. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Self-shaping of bioinspired chiral composites

NASA Astrophysics Data System (ADS)

Rong, Qing-Qing; Cui, Yu-Hong; Shimada, Takahiro; Wang, Jian-Shan; Kitamura, Takayuki

2014-08-01

Self-shaping materials such as shape memory polymers have recently drawn considerable attention owing to their high shape-changing ability in response to changes in ambient conditions, and thereby have promising applications in the biomedical, biosensing, soft robotics and aerospace fields. Their design is a crucial issue of both theoretical and technological interest. Motivated by the shape-changing ability of Towel Gourd tendril helices during swelling/deswelling, we present a strategy for realizing self-shaping function through the deformation of micro/nanohelices. To guide the design and fabrication of self-shaping materials, the shape equations of bent configurations, twisted belts, and helices of slender chiral composite are developed using the variation method. Furthermore, it is numerically shown that the shape changes of a chiral composite can be tuned by the deformation of micro/nanohelices and the fabricated fiber directions. This work paves a new way to create self-shaping composites.

Change in filter strip performance over ten years

Treesearch

M.G. Dosskey; K.D. Hoagland; J.R. Brandle

2007-01-01

Effectiveness of filter strips may change over a period of years because key soil and vegetation conditions change after conversion of cultivated farmland to permanent vegetation. the main objectives of this study were to : 1) determine if effectiveness of a filter strip changes over years since establishment, and 2) determine if temporal change depends on vegetation...

Forest structure and tree recruitment changes on a permanent historical Cinder Hills plot over a 130-year period (P-53)

Treesearch

Jacob H. Dyer; Andrew J. Sánchez Meador; Margaret M. Moore; Jonathan D. Bakker

2008-01-01

We examined forest structure, tree recruitment, and spatial pattern over a 130-year period on cinder soils in northern Arizona. Data were collected from a 3.24 ha permanent, stem-mapped plot established in 1909. This site is unique in that it represents ponderosa pine (Pinus ponderosa Laws. var. scopulorum Engelm.) growing on black cinder soils, which are of limited...

Countering Putins Nuclear-Backed Aggression with a Continuous Nuclear-Capable Bomber Presence

DTIC Science & Technology

2016-05-13

backed aggression can only be answered by a visible increase in nuclear capability in Europe. A nuclear-capable bomber force that permanently rotates ...permanently rotates through the EUCOM Area of Responsibility (AOR) would provide the United States with the ability to attack Putin’s strategy in three ways...One nuclear detonation in Europe would change the world. A BMD system cannot promise countries that it will negate every Russian nuclear missile

Assessment of Alphamagnetic Spectrometer (AMS) Upper Experiment Structural Configuration Shielding Effectiveness Associated with Change from Cryo-Cooled Magnet to Permanent Magnet

NASA Technical Reports Server (NTRS)

Scully, Robert

2012-01-01

In the spring of 2010, the Alpha Magnetic Spectrometer 2 (AMS-02) underwent a series of system level electromagnetic interference control measurements, followed by thermal vacuum testing. Shortly after completion of the thermal vacuum testing, the project decided to remove the cryogenically cooled superconducting magnet, and replace it with the original permanent magnet design employed in the earlier AMS- 01 assembly. Doing so necessitated several structural changes, as well as removal or modification of numerous electronic and thermal control devices and systems. At this stage, the project was rapidly approaching key milestone dates for hardware completion and delivery for launch, and had little time for additional testing or assessment of any impact to the electromagnetic signature of the AMS-02. Therefore, an analytical assessment of the radiated emissions behavioural changes associated with the system changes was requested.

Land-use and land-cover change in three corn belt ecoregions: Similarities and differences

USGS Publications Warehouse

Auch, Roger F.; Laingen, Chris R.; Drummond, Mark A.; Sayler, Kristi L.; Reker, Ryan R.; Bouchard, Michelle A.; Danielson, Jeffrey J.

2013-01-01

Land use categorical changes, though not as numerous as one might suspect, vary by type within the three designated ecozones of the Corn Belt with the westernmost zone showing the most temporary change vis-a-vis the more permanent changes taking place in the eastern and central zones.

An electrical-heating and self-sensing shape memory polymer composite incorporated with carbon fiber felt

NASA Astrophysics Data System (ADS)

Gong, Xiaobo; Liu, Liwu; Liu, Yanju; Leng, Jinsong

2016-03-01

Shape memory polymers (SMPs) have the ability to adjust their stiffness, lock a temporary shape, and recover the permanent shape upon imposing an appropriate stimulus. They have found their way into the field of morphing structures. The electrically Joule resistive heating of the conductive composite can be a desirable stimulus to activate the shape memory effect of SMPs without external heating equipment. Electro-induced SMP composites incorporated with carbon fiber felt (CFF) were explored in this work. The CFF is an excellent conductive filler which can easily spread throughout the composite. It has a huge advantage in terms of low cost, simple manufacturing process, and uniform and tunable temperature distribution while heating. A continuous and compact conductive network made of carbon fibers and the overlap joints among them was observed from the microscopy images, and this network contributes to the high conductive properties of the CFF/SMP composites. The CFF/SMP composites can be electrical-heated rapidly and uniformly, and its’ shape recovery effect can be actuated by the electrical resistance Joule heating of the CFF without an external heater. The CFF/SMP composite get higher modulus and higher strength than the pure SMP without losing any strain recovery property. The high dependence of temperature and strain on the electrical resistance also make the composite a good self-sensing material. In general, the CFF/SMP composite shows great prospects as a potential material for the future morphing structures.

Employment and sociodemographic characteristics: a study of increasing precarity in the health districts of Belo Horizonte, Brazil

PubMed Central

Coelho, Maria Cristina Ramos de Vasconcellos; Assunção, Ada Ávila; Belisário, Soraya Almeida

2009-01-01

Background The fundamental importance of human resources for the development of health care systems is recognized the world over. Health districts, which constitute the middle level of the municipal health care system in the city of Belo Horizonte, Brazil, deal with demands from all parts of the system. This research seeks to provide the essential features required in order to understand the phenomenon of increase in precarity of employment in these health districts. Methods The legal and human resource management documents used by the Municipal Health Secretariat of the City of Belo Horizonte were adopted as the corpus for this research. In order to analyse the changes in employment (2002–2006), the data were collected from ArteRH, a computerized database dealing specifically with data related to human resources, which began operating in 2001. The workers were classified into permanent and non-permanent groups, and their contractual rights were described. Employment dynamics and changes were examined, concentrating on the incorporation of workers and on their social and employment rights during the period under study. The comparative data for the two groups obtained were presented in frequency distribution tables according to type of employment, sex, age group, level of education and wages from 2002 to 2006. Results There was a clear difference between the permanent worker and non-permanent worker groups as regards existing guaranteed employment rights and social security. The increase in the number of non-permanent workers in the workforce, the growing proportion of older workers among the permanently employed and the real wage reductions during the period from 2002 to 2006 are indicative of the process of growing precarity of employment in the group studied. Conclusion It is a plausible supposition that the demand for health reforms, along with the legal limits imposed on financial expenditure, gave rise to the new types of contract and the present employment situation in the health districts in Belo Horizonte. PMID:19594922

Employment and sociodemographic characteristics: a study of increasing precarity in the health districts of Belo Horizonte, Brazil.

PubMed

de Vasconcellos Coelho, Maria Cristina Ramos; Assunção, Ada Avila; Belisário, Soraya Almeida

2009-07-13

The fundamental importance of human resources for the development of health care systems is recognized the world over. Health districts, which constitute the middle level of the municipal health care system in the city of Belo Horizonte, Brazil, deal with demands from all parts of the system. This research seeks to provide the essential features required in order to understand the phenomenon of increase in precarity of employment in these health districts. The legal and human resource management documents used by the Municipal Health Secretariat of the City of Belo Horizonte were adopted as the corpus for this research. In order to analyse the changes in employment (2002-2006), the data were collected from ArteRH, a computerized database dealing specifically with data related to human resources, which began operating in 2001. The workers were classified into permanent and non-permanent groups, and their contractual rights were described. Employment dynamics and changes were examined, concentrating on the incorporation of workers and on their social and employment rights during the period under study. The comparative data for the two groups obtained were presented in frequency distribution tables according to type of employment, sex, age group, level of education and wages from 2002 to 2006. There was a clear difference between the permanent worker and non-permanent worker groups as regards existing guaranteed employment rights and social security. The increase in the number of non-permanent workers in the workforce, the growing proportion of older workers among the permanently employed and the real wage reductions during the period from 2002 to 2006 are indicative of the process of growing precarity of employment in the group studied. It is a plausible supposition that the demand for health reforms, along with the legal limits imposed on financial expenditure, gave rise to the new types of contract and the present employment situation in the health districts in Belo Horizonte.

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.

Conceptual design of a compact high gradient quadrupole magnet of varying strength using permanent magnets

NASA Astrophysics Data System (ADS)

Sinha, Gautam

2018-02-01

A concept is presented to design magnets using cylindrical-shaped permanent-magnet blocks, where various types of magnetic fields can be produced by either rotating or varying the size of the magnetic blocks within a given mechanical structure. A general method is introduced to calculate the 3D magnetic field produced by a set of permanent magnets. An analytical expression of the 2D field and the condition to generate various magnetic fields like dipole, quadrupole, and sextupole are derived. Using the 2D result as a starting point, a computer code is developed to get the optimum orientation of the magnets to obtain the user-specific target field profile over a given volume in 3D. Designs of two quadrupole magnets are presented, one using 12 and the other using 24 permanent-magnet blocks. Variation of the quadrupole strength is achieved using tuning coils of a suitable current density and specially designed end tubes. A new concept is introduced to reduce the integrated quadrupole field strength by inserting two hollow cylindrical tubes made of iron, one at each end. This will not affect the field gradient at the center but reduce the integrated field strength by shielding the magnetic field near the ends where the tubes are inserted. The advantages of this scheme are that it is easy to implement, the magnetic axis will not shift, and it will prevent interference with nearby devices. Around 40% integrated field variation is achieved using this method in the present example. To get a realistic estimation of the field quality, a complete 3D model using a nonlinear B -H curve is also studied using a finite-element-based computer code. An example to generate around an 80 T /m quadrupole field gradient is also presented.

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

Longitudinal associations of experiences of adversity and socioeconomic disadvantage during childhood with labour force participation and exit in later adulthood.

PubMed

Fahy, A E; Stansfeld, S A; Smuk, M; Lain, D; van der Horst, M; Vickerstaff, S; Clark, C

2017-06-01

The Extending Working Lives (EWL) agenda seeks to sustain employment up to and beyond traditional retirement ages. This study examined the potential role of childhood factors in shaping labour force participation and exit among older adults, with a view to informing proactive interventions early in the life-course to enhance individuals' future capacity for extending their working lives. Childhood adversity and socioeconomic disadvantage have previously been linked to ill-health across the life-span and sickness benefit in early adulthood. This study builds upon previous research by examining associations between childhood adversity and self-reported labour force participation among older adults (aged 55). Data was from the National Child Development Study - a prospective cohort of all English, Scottish, & Welsh births in one week in 1958. There was evidence for associations between childhood adversity and increased risk of permanent sickness at 55 years - which were largely sustained after adjustment for educational disengagement and adulthood factors (mental/physical health, qualifications, socioeconomic disadvantage). Specifically, children who were abused or neglected were more likely to be permanently sick at 55 years. In addition, among males, those in care, those experiencing illness in the home, and those experiencing two or more childhood adversities were more likely to be permanently sick at 55 years. Childhood factors were also associated with part-time employment and retirement at 55 years. Severe childhood adversities may represent important distal predictors of labour force exit at 55 years, particularly via permanent sickness. Notably, some adversities show associations among males only, which may inform interventions designed to extend working lives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental Study for Reduction of Noises and Vibrations in Hermetic Type Compressor

NASA Astrophysics Data System (ADS)

Sano, Kiyoshi; Kawahara, Sadao; Akazawa, Teruyuki; Ishii, Noriaki

A brushless DC motor with a permanent magnet rotor has been adopted for a scroll compressor for domestic-use air-conditioners because of a demand for compressor high efficiency. A waveform of the driving voltage in the inverter power supply unit is chopped by the PWM signal. Its duty ratio is increased/decreased to control the DC voltage in order to provide a wide range of rotation frequencies for the compressor. The driving voltage includes the carrier frequency and its harmonic components, which produce an electro-magnetic force in the moter, resulting in high electro-magnetic noise. In the present report, the author clarifies the relationships between the noise and the waveform of driving voltage and frequency response function of the motor. A method to improve the frequency response function by changing the stator shape in order to reduce electro-magnetic noise is presented. Subsequently, the influence on electro-magnetic noise from the waveform of driving voltage is examined. Furthermore, the electro-magnetic noises during inverter driving of an induction motor are presented.

Flexible Foam Model.

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

Neilsen, Michael K.; Lu, Wei-Yang; Werner, Brian T.

Experiments were performed to characterize the mechanical response of a 15 pcf flexible polyurethane foam to large deformation at different strain rates and temperatures. Results from these experiments indicated that at room temperature, flexible polyurethane foams exhibit significant nonlinear elastic deformation and nearly return to their original undeformed shape when unloaded. However, when these foams are cooled to temperatures below their glass transition temperature of approximately -35 o C, they behave like rigid polyurethane foams and exhibit significant permanent deformation when compressed. Thus, a new model which captures this dramatic change in behavior with temperature was developed and implemented intomore » SIERRA with the name Flex_Foam to describe the mechanical response of both flexible and rigid foams to large deformation at a variety of temperatures and strain rates. This report includes a description of recent experiments. Next, development of the Flex Foam model for flexible polyurethane and other flexible foams is described. Selection of material parameters are discussed and finite element simulations with the new Flex Foam model are compared with experimental results to show behavior that can be captured with this new model.« less

Drivers of aboveground wood production in a lowland tropical forest of West Africa: teasing apart the roles of tree density, tree diversity, soil phosphorus, and historical logging.

PubMed

Jucker, Tommaso; Sanchez, Aida Cuni; Lindsell, Jeremy A; Allen, Harriet D; Amable, Gabriel S; Coomes, David A

2016-06-01

Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating climate change by storing carbon in wood. However, there remains considerable uncertainty as to whether tropical forests will continue to act as carbon sinks in the face of increased pressure from expanding human activities. Consequently, understanding what drives productivity in tropical forests is critical. We used permanent forest plot data from the Gola Rainforest National Park (Sierra Leone) - one of the largest tracts of intact tropical moist forest in West Africa - to explore how (1) stand basal area and tree diversity, (2) past disturbance associated with past logging, and (3) underlying soil nutrient gradients interact to determine rates of aboveground wood production (AWP). We started by statistically modeling the diameter growth of individual trees and used these models to estimate AWP for 142 permanent forest plots. We then used structural equation modeling to explore the direct and indirect pathways which shape rates of AWP. Across the plot network, stand basal area emerged as the strongest determinant of AWP, with densely packed stands exhibiting the fastest rates of AWP. In addition to stand packing density, both tree diversity and soil phosphorus content were also positively related to productivity. By contrast, historical logging activities negatively impacted AWP through the removal of large trees, which contributed disproportionately to productivity. Understanding what determines variation in wood production across tropical forest landscapes requires accounting for multiple interacting drivers - with stand structure, tree diversity, and soil nutrients all playing a key role. Importantly, our results also indicate that logging activities can have a long-lasting impact on a forest's ability to sequester and store carbon, emphasizing the importance of safeguarding old-growth tropical forests.

Dynamically Cross-linked Elastomer Hybrids with Light-Induced Rapid and Efficient Self-Healing Ability and Reprogrammable Shape Memory Behavior.

PubMed

Bai, Jing; Shi, Zixing

2017-08-16

Pristine carbon nanotubes (CNTs) were activated to exhibit Diels-Alder (DA) reactivity in a polymer matrix, which was modified with monomers containing furan groups. The DA-active polymer matrix was transferred into a dynamic reversible cross-linked inorganic-organic network via a Diels-Alder reaction with CNTs, where pristine CNTs were used as dienophile chemicals and furan-modified SBS acted as the macromolecular diene. In this system, the mechanical properties as well as resilience and solvent resistance were greatly improved even with the presence of only 1 wt % CNTs. Meanwhile, the hybrids retained recyclability and exhibited some smart behaviors, including self-healing and reprogrammable shape memory properties. Furthermore, due to the photothermal effect of CNTs, a retro-Diels-Alder (rDA) reaction was activated under laser irradiation, and healing of a crack on the hybrid surface was demonstrated in approximately 10 s with almost complete recovery of the mechanical properties. Such fast and efficient self-healing performance provides a new concept in designing self-healing nanocomposites with tunable structures and mechanical properties. Furthermore, the DA and rDA reactions could be combined to reprogram the shape memory behavior under laser irradiation or thermal treatment, wherein the temporary shape of the sample could be transferred to a permanent shape via the rDA reaction at high temperature.

Mode Conversion Behavior of Guided Wave in a Pipe Inspection System Based on a Long Waveguide.

PubMed

Sun, Feiran; Sun, Zhenguo; Chen, Qiang; Murayama, Riichi; Nishino, Hideo

2016-10-19

To make clear the mode conversion behavior of S0-mode lamb wave and SH0-plate wave converting to the longitudinal mode guided wave and torsional mode guided wave in a pipe, respectively, the experiments were performed based on a previous built pipe inspection system. The pipe was wound with an L-shaped plate or a T-shaped plate as the waveguide, and the S0-wave and SH0-wave were excited separately in the waveguide. To carry out the objective, a meander-line coil electromagnetic acoustic transducer (EMAT) for S0-wave and a periodic permanent magnet (PPM) EMAT for SH0-wave were developed and optimized. Then, several comparison experiments were conducted to compare the efficiency of mode conversion. Experimental results showed that the T(0,1) mode, L(0,1) mode, and L(0,2) mode guided waves can be successfully detected when converted from the S0-wave or SH0-wave with different shaped waveguides. It can also be inferred that the S0-wave has a better ability to convert to the T(0,1) mode, while the SH0-wave is easier to convert to the L(0,1) mode and L(0,2) mode, and the L-shaped waveguide has a better efficiency than T-shaped waveguide.

A Longitudinal Study of the Presence of Dental Anomalies in the Primary and Permanent Dentitions of Cleft Lip and/or Palate Patients.

PubMed

Suzuki, Akira; Nakano, Masayuki; Yoshizaki, Keigo; Yasunaga, Atsushi; Haruyama, Naoto; Takahashi, Ichiro

2017-05-01

  The aim is to survey primary and permanent dental anomalies: hypodontia, microdontia, a supernumerary tooth, and fused teeth in patients with cleft lip and/or palate.   Retrospective longitudinal study Subjects :  The subjects were selected from all 1724 patients with cleft lip and/or palate who were registered at the orthodontic clinic of Kyushu University Hospital, Fukuoka, Japan, from 1970 to 2009. Finally, 994 subjects were evaluated for primary dentition, 1352 for permanent dentition, and 871 for the longitudinal changes from primary to permanent dentition.   The prevalence of dental anomalies was compared for each tooth type, among various cleft types, between males and females, and between the alveolar cleft area and the noncleft area.   The prevalence of hypodontia was 16.2% for primary dentition and 52.7% for permanent dentition in the subjects with cleft lip and/or palate. Hypodontia increased with the severity of the cleft type. Multiple hypodontia was found more frequently in the subjects with bilateral cleft lip and palate and the subjects with unilateral cleft lip and palate. Microformed lateral incisors were found in 22.7% of permanent lateral incisors but not in primary dentition. Supernumerary teeth were found in 17.7% of the subjects with cleft lip and/or palate for primary maxillary dentition and in 5.7% for permanent maxillary dentition.   The prevalence of hypodontia was greater in permanent dentition than in primary dentition; although, it was not much different between males and females or between the right and left sides. The prevalence of dental anomalies was significantly different among four groups by cleft type: cleft lip, cleft lip and alveolus, cleft lip and palate, and cleft palate.

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

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).

The Effect of Early Visual Deprivation on the Neural Bases of Auditory Processing.

PubMed

Guerreiro, Maria J S; Putzar, Lisa; Röder, Brigitte

2016-02-03

Transient congenital visual deprivation affects visual and multisensory processing. In contrast, the extent to which it affects auditory processing has not been investigated systematically. Research in permanently blind individuals has revealed brain reorganization during auditory processing, involving both intramodal and crossmodal plasticity. The present study investigated the effect of transient congenital visual deprivation on the neural bases of auditory processing in humans. Cataract-reversal individuals and normally sighted controls performed a speech-in-noise task while undergoing functional magnetic resonance imaging. Although there were no behavioral group differences, groups differed in auditory cortical responses: in the normally sighted group, auditory cortex activation increased with increasing noise level, whereas in the cataract-reversal group, no activation difference was observed across noise levels. An auditory activation of visual cortex was not observed at the group level in cataract-reversal individuals. The present data suggest prevailing auditory processing advantages after transient congenital visual deprivation, even many years after sight restoration. The present study demonstrates that people whose sight was restored after a transient period of congenital blindness show more efficient cortical processing of auditory stimuli (here speech), similarly to what has been observed in congenitally permanently blind individuals. These results underscore the importance of early sensory experience in permanently shaping brain function. Copyright © 2016 the authors 0270-6474/16/361620-11$15.00/0.

Sub-micron fracture mechanism in silica-based glass activated by permanent densification from high-strain loading

DOE PAGES

Wereszczak, Andrew A.; Waters, Shirley B.; Parten, Randy J.; ...

2016-04-26

Several silica-based glasses were fractured at high strain energy via drop-weight testing on small specimens. A cylindrical specimen geometry was chosen to promote initially simple, axisymmetric, and uniform compressive loading. The imposed uniaxial compressive strain at impact was sufficiently high to qualitatively cause permanent densification. Produced fragments were collected for postmortem and a fraction of them, for all the silica-based glasses, consistently had distinct sub-micron-sized fractures (~ 300–1000 nm), designated here as “microkernels”, on their surfaces. They would most often appear as a sub-micron pore on the fragment - apparently if the microkernel had popped out as a consequence ofmore » the local crack plane running through it, tensile-strain release, and the associated formation of the fragment it was on. No fractographic evidence was found to show the microkernels were associated with local failure initiation. However, their positioning and habit sometimes suggested they were associated with localized crack branching and that they could have influenced secondary fracturing that occurred during overall crushing and comminution and associated fragment size and shape creation. Furthermore, the size range of these microkernels is much too small to affect structural flexure strength of these glasses for most applications but are of a size and concentration that may affect their ballistic, shock, crush, and comminution responses when permanent densification is concomitantly occurring.« less

Alignment and Integration Techniques for Mirror Segment Pairs on the Constellation X Telescope

NASA Technical Reports Server (NTRS)

Hadjimichael, Theo; Lehan, John; Olsen, Larry; Owens, Scott; Saha, Timo; Wallace, Tom; Zhang, Will

2007-01-01

We present the concepts behind current alignment and integration techniques for testing a Constellation-X primary-secondary mirror segment pair in an x-ray beam line test. We examine the effects of a passive mount on thin glass x-ray mirror segments, and the issues of mount shape and environment on alignment. We also investigate how bonding and transfer to a permanent housing affects the quality of the final image, comparing predicted results to a full x-ray test on a primary secondary pair.

Critical period revisited: impact on vision.

PubMed

Morishita, Hirofumi; Hensch, Takao K

2008-02-01

Neural circuits are shaped by experience in early postnatal life. The permanent loss of visual acuity (amblyopia) and anatomical remodeling within primary visual cortex following monocular deprivation is a classic example of critical period development from mouse to man. Recent work in rodents reveals a residual subthreshold potentiation of open eye response throughout life. Resetting excitatory-inhibitory balance or removing molecular 'brakes' on structural plasticity may unmask the potential for recovery of function in adulthood. Novel pharmacological or environmental interventions now hold great therapeutic promise based on a deeper understanding of critical period mechanisms.

33 CFR 329.13 - Geographic limits: Shifting boundaries.

Code of Federal Regulations, 2011 CFR

2011-07-01

... area will remain “navigable in law,” even though no longer covered with water, whenever the change has...: Shifting boundaries. Permanent changes of the shoreline configuration result in similar alterations of the boundaries of the navigable waters of the United States. Thus, gradual changes which are due to natural...

33 CFR 329.13 - Geographic limits: Shifting boundaries.

Code of Federal Regulations, 2013 CFR

2013-07-01

... area will remain “navigable in law,” even though no longer covered with water, whenever the change has...: Shifting boundaries. Permanent changes of the shoreline configuration result in similar alterations of the boundaries of the navigable waters of the United States. Thus, gradual changes which are due to natural...

33 CFR 329.13 - Geographic limits: Shifting boundaries.

Code of Federal Regulations, 2014 CFR

2014-07-01

... area will remain “navigable in law,” even though no longer covered with water, whenever the change has...: Shifting boundaries. Permanent changes of the shoreline configuration result in similar alterations of the boundaries of the navigable waters of the United States. Thus, gradual changes which are due to natural...

Permanent change of station: The NASA employee's guide to an easier move

NASA Technical Reports Server (NTRS)

1993-01-01

This guide is for the NASA employee preparing to make a permanent change of station. Whether a transferee or a new appointee, this guide contains information that will help a Government-authorized move go more smoothly from start to finish. The guide outlines the allowances and expense reimbursements one is entitled to under Federal Travel Regulations (FTR). It provides samples of forms one may need to fill out to start the transfer rolling and to claim reimbursements. However, it is important to note that this guide is not a copy of the FTR. Information in the FTR and the NASA Travel Regulations, FMM 9760, is far more detailed and is always updated and correct.

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

Bachman, D., E-mail: bachman@ualberta.ca; Fedosejevs, R.; Tsui, Y. Y.

An optical damage threshold for crystalline silicon from single femtosecond laser pulses was determined by detecting a permanent change in the refractive index of the material. This index change could be detected with unprecedented sensitivity by measuring the resonant wavelength shift of silicon integrated optics microring resonators irradiated with femtosecond laser pulses at 400 nm and 800 nm wavelengths. The threshold for permanent index change at 400 nm wavelength was determined to be 0.053 ± 0.007 J/cm{sup 2}, which agrees with previously reported threshold values for femtosecond laser modification of crystalline silicon. However, the threshold for index change at 800 nm wavelength was found to be 0.044 ± 0.005 J/cm{supmore » 2}, which is five times lower than the previously reported threshold values for visual change on the silicon surface. The discrepancy is attributed to possible modification of the crystallinity of silicon below the melting temperature that has not been detected before.« less

Meeting the Housing and Care Needs of Older Homeless Adults: A Permanent Supportive Housing Program Targeting Homeless Elders.

PubMed

Brown, Rebecca T; Thomas, M Lori; Cutler, Deborah F; Hinderlie, Mark

2013-01-01

The homeless population is aging faster than the general population in the United States. As this vulnerable population continues to age, addressing complex care and housing needs will become increasingly important. This article reviews the often-overlooked issue of homelessness among older adults, including their poor health status and unique care needs, the factors that contribute to homelessness in this population, and the costs of homelessness to the U.S. health care system. Permanent supportive housing programs are presented as a potential solution to elder homelessness, and Hearth, an outreach and permanent supportive housing model in Boston, is described. Finally, specific policy changes are presented that could promote access to housing among the growing older homeless population.

Variable Permanent Magnet Quadrupole

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

Mihara, T.; Iwashita, Y.; /Kyoto U.

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four partsmore » and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.« less

New findings on object permanence: A developmental difference between two types of occlusion

PubMed Central

Moore, M. Keith; Meltzoff, Andrew N.

2013-01-01

Manual search for totally occluded objects was investigated in 10-, 12- and 14-month-old infants. Infants responded to two types of total hiding in different ways, supporting the inference that object permanence is not a once-and-for-all attainment. Occlusion of an object by movement of a screen over it was solved at an earlier age than occlusion in which an object was carried under the screen. This dissociation was not explained by motivation, motor skill or means–ends coordination, because for both tasks the same object was hidden in the same place under the same screen and required the same uncovering response. This dissociation generalized across an experimentally manipulated change in recovery means—infants removed cloths while seated at a table in Expt 1 and were required to crawl through 3-D space to displace semi-rigid pillows in Expt 2. Further analysis revealed that emotional response varied as a function of hiding, suggesting an affective correlate of infant cognition. There are four empirical findings to account for: developmental change, task dissociation, generalization of the effects across recovery means, and emotional reactions. An identity-development theory is proposed explaining these findings in terms of infants’ understanding of object identity and the developmental relationship between object identity and object permanence. Object identity is seen as a necessary precursor to the development of object permanence. PMID:25364086

New findings on object permanence: A developmental difference between two types of occlusion.

PubMed

Moore, M Keith; Meltzoff, Andrew N

1999-11-01

Manual search for totally occluded objects was investigated in 10-, 12- and 14-month-old infants. Infants responded to two types of total hiding in different ways, supporting the inference that object permanence is not a once-and-for-all attainment. Occlusion of an object by movement of a screen over it was solved at an earlier age than occlusion in which an object was carried under the screen. This dissociation was not explained by motivation, motor skill or means-ends coordination, because for both tasks the same object was hidden in the same place under the same screen and required the same uncovering response. This dissociation generalized across an experimentally manipulated change in recovery means-infants removed cloths while seated at a table in Expt 1 and were required to crawl through 3-D space to displace semi-rigid pillows in Expt 2. Further analysis revealed that emotional response varied as a function of hiding, suggesting an affective correlate of infant cognition. There are four empirical findings to account for: developmental change, task dissociation, generalization of the effects across recovery means, and emotional reactions. An identity-development theory is proposed explaining these findings in terms of infants' understanding of object identity and the developmental relationship between object identity and object permanence. Object identity is seen as a necessary precursor to the development of object permanence.

Intrapulpal Thermal Changes during Setting Reaction of Glass Carbomer® Using Thermocure Lamp.

PubMed

Kahvecioglu, Firdevs; Tosun, Gül; Ülker, Hayriye Esra

2016-01-01

Objectives . To measure the temperature increase induced during thermocure lamp setting reaction of glass carbomer and to compare it with those induced by visible light curing of a resin-modified glass ionomer and a polyacid-modified composite resin in primary and permanent teeth. Materials and Methods . Nonretentive class I cavities were prepared in extracted primary and permanent molars. Glass carbomer (GC) was placed in the cavity and set at 60°C for 60 sn using a special thermocure lamp. Resin-modified glass ionomer (RMGIC) and polyacid-modified composite resin (PMCR) were placed in the cavities and polymerized with an LED curing unit. Temperature increases during setting reactions were measured with a J-type thermocouple wire connected to a data logger. Data were examined using two-way analysis of variance and Tukey's honestly significant difference tests. Results . The use of GC resulted in temperature changes of 5.17 ± 0.92°C and 5.32 ± 0.90°C in primary and permanent teeth, respectively ( p > 0.05). Temperature increases were greatest in the GC group, differing significantly from those in the PMCR group ( p < 0.05). Conclusion . Temperature increases during polymerization and setting reactions of the materials were below the critical value in all groups. No difference was observed between primary and permanent teeth, regardless of the material used.

Theatre for Change: An Analysis of Two Performances by Women in Mundemba Sub-Division.

ERIC Educational Resources Information Center

Tanyi-Tang, Anne

2001-01-01

Contends that theatre has the power to induce oppressors to change their attitudes permanently towards the groups they oppress. Describes theatrical performances by women in Mundemba Sub-Division, Cameroon, which created lasting changes in men's attitudes. Concludes that theatre calls for sociocultural and economic changes and it has the power to…

Changing Education for a Changing World: Internationalizing Education

ERIC Educational Resources Information Center

Idogho, Philipa Omamhe; Eshiotse, Sunday Gabriel

2012-01-01

That change is permanent has never been an issue, but how to anticipate, adopt, equip, and re-position to optimize benefits of change is the heart of research. Thus, true to Marshall McLuhan's prophetic foresight, the world, indeed, has become a village where otherwise local events now exert profound global consequences. In this paper, the…

Dynamics of slow-moving landslides from permanent scatterer analysis.

PubMed

Hilley, George E; Bürgmann, Roland; Ferretti, Alessandro; Novali, Fabrizio; Rocca, Fabio

2004-06-25

High-resolution interferometric synthetic aperture radar (InSAR) permanent scatterer data allow us to resolve the rates and variations in the rates of slow-moving landslides. Satellite-to-ground distances (range changes) on landslides increase at rates of 5 to 7 millimeters per year, indicating average downslope sliding velocities from 27 to 38 millimeters per year. Time-series analysis shows that displacement occurs mainly during the high-precipitation season; during the 1997-1998 El Niño event, rates of range change increased to as much as 11 millimeters per year. The observed nonlinear relationship of creep and precipitation rates suggests that increased pore fluid pressures within the shallow subsurface may initiate and accelerate these features. Changes in the slope of a hill resulting from increases in the pore pressure and lithostatic stress gradients may then lead to landslides.

On the Stator Slot Geometry of a Cable Wound Generator for Hydrokinetic Energy Conversion

PubMed Central

Grabbe, Mårten; Leijon, Mats

2015-01-01

The stator slot geometry of a cable wound permanent magnet synchronous generator for hydrokinetic energy conversion is evaluated. Practical experience from winding two cable wound generators is used to propose optimized dimensions of different parts in the stator slot geometry. A thorough investigation is performed through simulations of how small geometrical changes alter the generator performance. The finite element method (FEM) is used to model the generator and the simulations show that small changes in the geometry can have large effect on the performance of the generator. Furthermore, it is concluded that the load angle is especially sensitive to small geometrical changes. A new generator design is proposed which shows improved efficiency, reduced weight, and a possibility to decrease the expensive permanent magnet material by almost one-fifth. PMID:25879072

Self-shaping composites with programmable bioinspired microstructures.

PubMed

Erb, Randall M; Sander, Jonathan S; Grisch, Roman; Studart, André R

2013-01-01

Shape change is a prevalent function apparent in a diverse set of natural structures, including seed dispersal units, climbing plants and carnivorous plants. Many of these natural materials change shape by using cellulose microfibrils at specific orientations to anisotropically restrict the swelling/shrinkage of their organic matrices upon external stimuli. This is in contrast to the material-specific mechanisms found in synthetic shape-memory systems. Here we propose a robust and universal method to replicate this unusual shape-changing mechanism of natural systems in artificial bioinspired composites. The technique is based upon the remote control of the orientation of reinforcing inorganic particles within the composite using a weak external magnetic field. Combining this reinforcement orientational control with swellable/shrinkable polymer matrices enables the creation of composites whose shape change can be programmed into the material's microstructure rather than externally imposed. Such bioinspired approach can generate composites with unusual reversibility, twisting effects and site-specific programmable shape changes.

Self-shaping composites with programmable bioinspired microstructures

NASA Astrophysics Data System (ADS)

Erb, Randall M.; Sander, Jonathan S.; Grisch, Roman; Studart, André R.

2013-04-01

Shape change is a prevalent function apparent in a diverse set of natural structures, including seed dispersal units, climbing plants and carnivorous plants. Many of these natural materials change shape by using cellulose microfibrils at specific orientations to anisotropically restrict the swelling/shrinkage of their organic matrices upon external stimuli. This is in contrast to the material-specific mechanisms found in synthetic shape-memory systems. Here we propose a robust and universal method to replicate this unusual shape-changing mechanism of natural systems in artificial bioinspired composites. The technique is based upon the remote control of the orientation of reinforcing inorganic particles within the composite using a weak external magnetic field. Combining this reinforcement orientational control with swellable/shrinkable polymer matrices enables the creation of composites whose shape change can be programmed into the material’s microstructure rather than externally imposed. Such bioinspired approach can generate composites with unusual reversibility, twisting effects and site-specific programmable shape changes.

Hydroxyapatite with Permanent Electrical Polarization: Preparation, Characterization, and Response against Inorganic Adsorbates.

PubMed

Rivas, Manuel; Del Valle, Luis J; Armelin, Elaine; Bertran, Oscar; Turon, Pau; Puiggalí, Jordi; Alemán, Carlos

2018-04-16

Permanently polarized hydroxyapatite (HAp) particles have been prepared by applying a constant DC of 500 V at 1000 °C for 1 h to the sintered mineral. This process causes important chemical changes, as the formation of OH - defects (vacancies), the disappearance of hydrogenophosphate ions at the mineral surface layer, and structural variations reflected by the increment of the crystallinity. As a consequence, the electrochemical properties and electrical conductivity of the polarized mineral increase noticeably compared with as-prepared and sintered samples. Moreover, these increments remain practically unaltered after several months. In addition, permanent polarization favours significantly the ability of HAp to adsorb inorganic bioadsorbates in comparison with as-prepared and sintered samples. The adsorbates cause a significant increment of the electrochemical stability and electrical conductivity with respect to bare polarized HAp, which may have many implications for biomedical applications of permanently polarized HAp. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Making Water Ice Permanent at the South Pole 25000 Years Ago

NASA Astrophysics Data System (ADS)

Montmessin, F.; Haberle, R. M.; Forget, F.

2004-03-01

Whereas most of studies on recent climate change address the fate of water with changing obliquities, we would like to show how the precession cycle might affect the stability of the north polar cap on much faster timescales.

The Development of Categorization in the Second Year and Its Relation to Other Cognitive and Linguistic Developments.

ERIC Educational Resources Information Center

Gopnik, Alison; Meltzoff, Andrew

1987-01-01

Changes in children's categorization behavior between 15 and 21 months of age and the relation of these changes to developments in language, object permanence, and means-end understanding are reported. (PCB)

The U-shaped association of body mass index with mortality: Influence of the traits height, intelligence, and education.

PubMed

Jørgensen, Terese Sara Høj; Osler, Merete; Ängquist, Lars Henrik; Zimmermann, Esther; Christensen, Gunhild Tidemann; Sørensen, Thorkild I A

2016-10-01

The U-shaped association between body mass index (BMI) and mortality may depend on other traits with permanent health effects. Whether the association between BMI and mortality depends on levels of health-related traits known to be inversely associated with mortality throughout adult life such as height, intelligence, and education was investigated. The study was based on a cohort of young men with data on weight, height, intelligence test score, and education from the Danish Conscription Database. In total, 346,500 men born 1939 to 1959 were followed until December 2013. The association between BMI and mortality was analyzed using Cox-regression models including interactions between BMI and height, intelligence, and education, respectively. BMI and mortality showed the U-shaped association from the start of the follow-up period, and it persisted through the subsequent 56 years. As expected, the mortality was inversely associated with height, intelligence, and education, but the U shape of the association between BMI and mortality was unaffected by the levels of these traits except at higher BMI values, where the slopes were steeper for men with higher levels of height, intelligence, and education. High and low BMI was associated with higher mortality throughout life regardless of the levels of height, intelligence, and education. © 2016 The Obesity Society.

[Permanent essential defacement--remarks on the possibilities of verification of the accepted criteria in medico-legal certification in criminal and civil law proceedings].

PubMed

Chowaniec, Czesław; Nowak, Agnieszka; Jabłoński, Christian; Neniczka, Stanisława

2007-01-01

Despite the fact that some criteria of medico-legal certification in criminal and civil proceedings have been established, there are still some topics which are controversial and thus require modification. This is also true of the notion of "permanent essential defacement". In the opinion of the authors, changes in social conventions that are occurring nowadays, as well as a highly diversified, subjective perception of esthetic values indicate the need for discussing a possible modification of the presently obligatory criteria. Apart from the assessment of posttraumatic changes, an important problem is posed by defining the notion of "a part of the body customarily open to the view ". Additionally, the authors bring up for discussion the issue of experts taking into consideration the age and sex of the victims while assessing damages. A separate problem lies in difficulties in assessing the degree of detriment to health because of defacement due to the fact that official tables for evaluating permanent or long-term detriment to health do not include relevant information.

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

Models And Experiments Of Laminar Diffusion Flames In Non-Uniform Magnetic Fields

NASA Technical Reports Server (NTRS)

Baker, J.; Varagani, R.; Saito, K.

2003-01-01

Non-uniform magnetic fields affect laminar diffusion flames as a result of the paramagnetic and diamagnetic properties of the products and reactants. Paramagnetism is the weak attraction to a magnetic field a material exhibits as a result of permanent magnetic dipole moments in the atoms of the material. Diamagnetism is the weak repulsion to a magnetic field exhibited by a material due to the lack of permanent magnetic dipole moments in the atoms of a material. The forces associated with paramagnetic and diamagnetism are several orders of magnitude less than the forces associated with the more familiar ferromagnetism. A typical example of a paramagnetic gas is oxygen while hydrocarbon fuels and products of combustion are almost always diamagnetic. The fact that magnets can affect flame behavior has been recognized for more than one hundred years. Early speculation was that such behavior was due to the magnetic interaction with the ionized gases associated with a flame. Using a scaling analysis, it was later shown that for laminar diffusion flames the magnetic field/ionized gas interaction was insignificant to the paramagnetic and diamagnetic influences. In this effort, the focus has been on examining laminar diffusion slot flames in the presence of non-uniform upward decreasing magnetic fields produced using permanent magnets. The principal reason for choosing slot flames was mathematical models of such flames show an explicit dependence on gravitational body forces, in the buoyancy-controlled regime, and an applied magnetic field would also impose a body force. In addition, the behavior of such flames was more easily visualized while maintaining the symmetry of the two-dimensional problem whereas it would have been impossible to obtain a symmetric magnetic field around a circular flame and still visually record the flame height and shape along the burner axis. The motivation for choosing permanent magnets to produce the magnetic fields was the assumption that space-related technologies based on the knowledge gained during this investigation would more likely involve permanent magnets as opposed to electromagnets. While no analysis has been done here to quantify the impact that an electric field, associated with an electromagnetic, would have relative to the paramagnetic and diamagnetic interactions, by using permanent magnets this potential effect was completely eliminated and thus paramagnetic and diamagnetic effects were isolated.

Current Bypassing Properties by Thermal Switch for PCS Application on NMR/MRI HTS Magnets

NASA Astrophysics Data System (ADS)

Kim, S. B.; Takahashi, M.; Saito, R.; Park, Y. J.; Lee, M. W.; Oh, Y. K.; Ann, H. S.

We develop the compact NMR/MRI device using high temperature superconducting (HTS) wires with the persistent current mode operating. So, the joint techniques between 2G wires are very important issue and many studies have been carried out. Recently, the Kbigdot JOINS, Inc. has developed successfully the high performance superconducting joints between 2G wires by partial melting diffusion and oxygenation annealing process [1]. In this study, the current bypassing properties in a loop-shaped 2G wire are measured experimentally to develop the permanent current switch (PSC). The current bypassing properties of loop-shaped test coil wound with 2G wire (GdBCO) are evaluated by measured the self-magnetic field due to bypassed current by Hall sensors. The strain gauge was used as heater for persistent current switch, and thermal properties against various thermal inputs were investigated experimentally.

Permanent wire splicing by an explosive joining process

NASA Technical Reports Server (NTRS)

Bement, Laurence J. (Inventor); Kushnick, Anne C. (Inventor)

1991-01-01

The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebent, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires, and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding results in electron sharing linkups.

Stacking faults density driven collapse of magnetic energy in hcp-cobalt nano-magnets

NASA Astrophysics Data System (ADS)

Nong, H. T. T.; Mrad, K.; Schoenstein, F.; Piquemal, J.-Y.; Jouini, N.; Leridon, B.; Mercone, S.

2017-06-01

Cobalt nanowires with different shape parameters were synthesized via the polyol process. By calculating the magnetic energy product (BH max) both for dried nano-powder and for nanowires in their synthesis solution, we observed unexpected independent BH max values from the nanowires shape. A good alignment of the nanowires leads to a higher BH max value. Our results show that the key parameter driving the magnetic energy product of the cobalt nanowires is the stacking fault density. An exponential collapse of the magnetic energy is observed at very low percentage of structural faults. Cobalt nanowires with almost perfect hcp crystalline structures should present high magnetic energy, which is promising for application in rare earth-free permanent magnets. Oral talk at 8th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2016), 8-12 November 2016, Ha Long City, Vietnam.

Using hybrid magnetic bearings to completely suspend the impeller of a ventricular assist device.

PubMed

Khanwilkar, P; Olsen, D; Bearnson, G; Allaire, P; Maslen, E; Flack, R; Long, J

1996-06-01

Clinically available blood pumps and those under development suffer from poor mechanical reliability and poor biocompatibility related to anatomic fit, hemolysis, and thrombosis. To alleviate these problems concurrently in a long-term device is a substantial challenge. Based on testing the performance of a prototype, and on our judgment of desired characteristics, we have configured an innovative ventricular assist device, the CFVAD4, for long-term use. The design process and its outcome, the CFVAD4 system configuration, is described. To provide unprecedented reliability and biocompatibility, magnetic bearings completely suspend the rotating pump impeller. The CFVAD4 uses a combination of passive (permanent) and active (electric) magnetic bearings, a mixed flow impeller, and a slotless 3-phase brushless DC motor. These components are shaped, oriented, and integrated to provide a compact, implantable, pancake-shaped unit for placement in the left upper abdominal quadrant of adult humans.

Novel pre-alloyed powder processing of modified alnico 8: Correlation of microstructure and magnetic properties

DOE PAGES

Anderson, I. E.; Kassen, A. G.; White, E. M. H.; ...

2015-04-13

Progress is reviewed on development of an improved near-final bulk magnet fabrication process for alnico 8, as a non-rare earth permanent magnet with promise for sufficient energy density and coercivity for electric drive motors. This study showed that alnico bulk magnets in near-final shape can be made by simple compression molding from spherical high purity gas atomized pre-alloyed powder. Dwell time at peak sintering temperature (1250°C) greatly affected grain size of the resulting magnet alloys. This microstructure transformation was demonstrated to be useful for gaining partially aligned magnetic properties and boosting energy product. Furthermore, while a route to increased coercivitymore » was not identified by these experiments, manufacturability of bulk alnico magnet alloys in near-final shapes was demonstrated, permitting further processing and alloy modification experiments that can target higher coercivity and better control of grain anisotropy during grain growth.« less

Macrodontia, shovel-shaped incisors, and multituberculism: probable Ekman-Westborg-Julin trait.

PubMed

Reardon, Gayle Tieszen; Slayton, L Rebecca; Norby, Clinton; Geneser, Teresa

2012-01-01

Multiple macrodontia is a rare finding and is defined as a condition in which a tooth is significantly larger than normal. Macrodontia may occur as an isolated finding, part of a group of dental anomalies, or as a component of a syndrome with multiple oral and systemic manifestations. The purpose of this paper was to report a case of macrodontia affecting all permanent teeth and exhibiting shovel-shaped maxillary and mandibular incisors and multituberculate molars and premolars. Some or all of this patient's characteristics have been reported in both males and females, with a ratio of 5:2. No inheritance pattern has been established, as these traits have generally occurred spontaneously. As more individuals are identified and as molecular techniques continue to advance, it is probable that a gene or genes responsible for macrodontia and the associated traits will be identified.

Physiological mechanism of the overproduction of ε-poly-L-lysine by acidic pH shock in fed-batch fermentation.

PubMed

Ren, Xi-Dong; Chen, Xu-Sheng; Tang, Lei; Zeng, Xin; Wang, Liang; Mao, Zhong-Gui

2015-11-01

The introduction of an environmental stress of acidic pH shock had successfully solved the common deficiency existed in ε-PL production, viz. the distinct decline of ε-PL productivity in the feeding phase of the fed-batch fermentation. To unravel the underlying mechanism, we comparatively studied the physiological changes of Streptomyces sp. M-Z18 during fed-batch fermentations with the pH shock strategy (PS) and pH non-shock strategy (PNS). Morphology investigation showed that pellet-shape change was negligible throughout both fermentations. In addition, the distribution of pellet size rarely changed in the PS, whereas pellet size and number decreased substantially with time in the PNS. This was consistent with the performances of ε-PL productivity in both strategies, demonstrating that morphology could be used as a predictor of ε-PL productivity during fed-batch fermentation. Furthermore, a second growth phase happened in the PS after pH shock, followed by the re-appearance of live mycelia in the dead core of the pellets. Meanwhile, mycelia respiration and key enzymes in the central metabolic and ε-PL biosynthetic pathways were overall strengthened until the end of the fed-batch fermentation. As a result, the physiological changes induced by the acidic pH shock have synergistically and permanently contributed to the stimulation of ε-PL productivity. However, this second growth phase and re-appearance of live mycelia were absent in the PNS. These results indicated that the introduction of a short-term suppression on mycelia physiological metabolism would guarantee the long-term high ε-PL productivity.

7 CFR 3575.80 - Interest rate changes after loan closing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Interest rate changes after loan closing. 3575.80..., DEPARTMENT OF AGRICULTURE GENERAL Community Programs Guaranteed Loans § 3575.80 Interest rate changes after...) may collectively effect a permanent reduction in the interest rate on the guaranteed loan at any time...

7 CFR 1779.80 - Interest rate changes after loan closing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 12 2010-01-01 2010-01-01 false Interest rate changes after loan closing. 1779.80....80 Interest rate changes after loan closing. (a) General. Subject to the restrictions below, the borrower, lender, and holder (if any) may collectively effect a permanent reduction in the interest rate on...

27 CFR 31.131 - Change of address.

Code of Federal Regulations, 2010 CFR

2010-04-01

... form, TTB Form 5630.5d, on or before the next July 1 following the change. (b) Caterers. A caterer who... those catering activities, provided that the caterer maintains the records required by § 31.95(c). For a permanent change in location of the principal place of business, the caterer must file an amended...

Changing Our Minds: Negotiating English and Literacy.

ERIC Educational Resources Information Center

Myers, Miles

Suggesting that the United States' dominant form of literacy is contingent and historical, not permanent and absolute, this book asserts that when a society changes its definition of literacy, it also changes its models of mind and its models for teaching English. The book challenges the assumption that the public schools are a failure, arguing…

36 CFR 1225.26 - How do agencies change a disposition authority?

Code of Federal Regulations, 2010 CFR

2010-07-01

... RECORDS ADMINISTRATION RECORDS MANAGEMENT SCHEDULING RECORDS § 1225.26 How do agencies change a... must secure NARA approval of a change in the period of time that permanent records will remain in... (NWM), 8601 Adelphi Road, College Park, MD 20740-6001, phone number (301) 837-1738. NARA approval is...

3D Printed Reversible Shape Changing Components with Stimuli Responsive Materials

PubMed Central

Mao, Yiqi; Ding, Zhen; Yuan, Chao; Ai, Shigang; Isakov, Michael; Wu, Jiangtao; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

2016-01-01

The creation of reversibly-actuating components that alter their shapes in a controllable manner in response to environmental stimuli is a grand challenge in active materials, structures, and robotics. Here we demonstrate a new reversible shape-changing component design concept enabled by 3D printing two stimuli responsive polymers—shape memory polymers and hydrogels—in prescribed 3D architectures. This approach uses the swelling of a hydrogel as the driving force for the shape change, and the temperature-dependent modulus of a shape memory polymer to regulate the time of such shape change. Controlling the temperature and aqueous environment allows switching between two stable configurations – the structures are relatively stiff and can carry load in each – without any mechanical loading and unloading. Specific shape changing scenarios, e.g., based on bending, or twisting in prescribed directions, are enabled via the controlled interplay between the active materials and the 3D printed architectures. The physical phenomena are complex and nonintuitive, and so to help understand the interplay of geometric, material, and environmental stimuli parameters we develop 3D nonlinear finite element models. Finally, we create several 2D and 3D shape changing components that demonstrate the role of key parameters and illustrate the broad application potential of the proposed approach. PMID:27109063

3D Printed Reversible Shape Changing Components with Stimuli Responsive Materials

NASA Astrophysics Data System (ADS)

Mao, Yiqi; Ding, Zhen; Yuan, Chao; Ai, Shigang; Isakov, Michael; Wu, Jiangtao; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

2016-04-01

The creation of reversibly-actuating components that alter their shapes in a controllable manner in response to environmental stimuli is a grand challenge in active materials, structures, and robotics. Here we demonstrate a new reversible shape-changing component design concept enabled by 3D printing two stimuli responsive polymers—shape memory polymers and hydrogels—in prescribed 3D architectures. This approach uses the swelling of a hydrogel as the driving force for the shape change, and the temperature-dependent modulus of a shape memory polymer to regulate the time of such shape change. Controlling the temperature and aqueous environment allows switching between two stable configurations - the structures are relatively stiff and can carry load in each - without any mechanical loading and unloading. Specific shape changing scenarios, e.g., based on bending, or twisting in prescribed directions, are enabled via the controlled interplay between the active materials and the 3D printed architectures. The physical phenomena are complex and nonintuitive, and so to help understand the interplay of geometric, material, and environmental stimuli parameters we develop 3D nonlinear finite element models. Finally, we create several 2D and 3D shape changing components that demonstrate the role of key parameters and illustrate the broad application potential of the proposed approach.

Permanent magnetic ferrite based power-tunable metamaterials

NASA Astrophysics Data System (ADS)

Zhang, Guanqiao; Lan, Chuwen; Gao, Rui; Zhou, Ji

2017-08-01

Power-tunable metamaterials based on barium permanent magnetic ferrite have been proposed and fabricated in this research. Scattering parameter measurements confirm a shift in resonant frequency in correlation to changes in incident electromagnetic power within microwave frequency band. The tunable phenomenon represented by a blue-shift in transmission spectra in the metamaterials array can be attributed to a decrease in saturation magnetization resulting from FMR-induced temperature elevation upon resonant conditions. This power-dependent behavior offers a simple and practical route towards dynamically fine-tunable ferrite metamaterials.

40 CFR 60.14 - Modification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... physical change, or change in the method of operation, at an existing electric utility steam generating... projects that are awarded funding from the Department of Energy as permanent clean coal technology... installation, operation, cessation, or removal of a temporary clean coal technology demonstration project is...

25 CFR 103.34 - What if the lender and borrower decide to change the terms of the loan?

Code of Federal Regulations, 2011 CFR

2011-04-01

... written BIA approval before modifying a loan guaranteed or insured under the Program, if the change will... accrued loan interest it otherwise would have difficulty paying. (2) Permanently adjust the loan repayment...

25 CFR 103.34 - What if the lender and borrower decide to change the terms of the loan?

Code of Federal Regulations, 2014 CFR

2014-04-01

... written BIA approval before modifying a loan guaranteed or insured under the Program, if the change will... accrued loan interest it otherwise would have difficulty paying. (2) Permanently adjust the loan repayment...

25 CFR 103.34 - What if the lender and borrower decide to change the terms of the loan?

Code of Federal Regulations, 2012 CFR

2012-04-01

... written BIA approval before modifying a loan guaranteed or insured under the Program, if the change will... accrued loan interest it otherwise would have difficulty paying. (2) Permanently adjust the loan repayment...

25 CFR 103.34 - What if the lender and borrower decide to change the terms of the loan?

Code of Federal Regulations, 2010 CFR

2010-04-01

... written BIA approval before modifying a loan guaranteed or insured under the Program, if the change will... accrued loan interest it otherwise would have difficulty paying. (2) Permanently adjust the loan repayment...

25 CFR 103.34 - What if the lender and borrower decide to change the terms of the loan?

Code of Federal Regulations, 2013 CFR

2013-04-01

... written BIA approval before modifying a loan guaranteed or insured under the Program, if the change will... accrued loan interest it otherwise would have difficulty paying. (2) Permanently adjust the loan repayment...

Modified Endonasal Tongue-in-Groove Technique.

PubMed

Kadakia, Sameep; Ovchinsky, Alexander

2016-10-01

Achieving stable and desirable changes in tip rotation (TR) and tip projection (TP) is among the primary goals of modern day rhinoplasty. The tongue-in-groove (TIG) technique is one technique in rhinoplasty used to improve TR and/or TP. Performing TIG endonasally using a permanent suture can be quite cumbersome as the suture needs to be buried under the skin. We describe a variation of TIG technique for endonasal rhinoplasty using a permanent suture buried in small columellar skin incisions. The technique details are described and the postoperative changes in TR and TP are analyzed for the degree of change and longevity. A retrospective review of the preoperative and postoperative photographs of 12 patients treated with the endonasal TIG technique were analyzed for changes in TR and TP. Out of 12 patients, there were seven females (58.3%) and five males (41.7%), with age ranging from 17 to 49 years. The follow-up ranged from 6 months to 53 months, with mean follow-up of 12.1 months. All patients were treated by the senior author in a major New York City hospital. Postoperative changes in TR and TP were compared by measuring the nasolabial angle as well as the Goode ratio using a photo editing software. Using a t-test and a p-value criteria of 0.05, the difference between the preoperative and postoperative TR (p = 0.0069) and TP (p = 0.026) was found to be statistically significant. None of the study patients developed any complications related to the use of a permanent suture material during the follow-up period. Our modified TIG technique is a quick, reliable, and safe option in the surgical armamentarium to achieve desired changes in TR and/or TP.  4. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Meeting the Housing and Care Needs of Older Homeless Adults: A Permanent Supportive Housing Program Targeting Homeless Elders

PubMed Central

Brown, Rebecca T.; Thomas, M. Lori; Cutler, Deborah F.; Hinderlie, Mark

2014-01-01

The homeless population is aging faster than the general population in the United States. As this vulnerable population continues to age, addressing complex care and housing needs will become increasingly important. This article reviews the often-overlooked issue of homelessness among older adults, including their poor health status and unique care needs, the factors that contribute to homelessness in this population, and the costs of homelessness to the U.S. health care system. Permanent supportive housing programs are presented as a potential solution to elder homelessness, and Hearth, an outreach and permanent supportive housing model in Boston, is described. Finally, specific policy changes are presented that could promote access to housing among the growing older homeless population. PMID:24729832

[Innovations in continuing/permanent education methods for the intensive care nurses].

PubMed

Vázquez Guillamet, B; Guillamet Lloveras, A; Martínez Estalella, G; Pérez Ramírez, F

2014-01-01

Intensive care nursing is carried out in a dynamic environment characterized by the continuous incorporation of new technologies, approaches to care and a request for safety, participation and transparency by the public. Continuing/permanent intensive care nursing training in the acquisition of new competencies is key in this setting. In order to achieve this goal, simulation and problem based learning should be incorporated as essential methodologies to teach these skills. At the same time research should be done on which attitudes, competences, and knowledge are necessary to increase their intellectual knowledge. The core characteristics of ICU and its nursing should allow a deep change in their approach to continuing/permanent nursing education. Copyright © 2013 Elsevier España, S.L. y SEEIUC. All rights reserved.

Health information technology: standards, implementation specifications, and certification criteria for electronic health record technology, 2014 edition; revisions to the permanent certification program for health information technology. Final rule.

PubMed

2012-09-04

With this final rule, the Secretary of Health and Human Services adopts certification criteria that establish the technical capabilities and specify the related standards and implementation specifications that Certified Electronic Health Record (EHR) Technology will need to include to, at a minimum, support the achievement of meaningful use by eligible professionals, eligible hospitals, and critical access hospitals under the Medicare and Medicaid EHR Incentive Programs beginning with the EHR reporting periods in fiscal year and calendar year 2014. This final rule also makes changes to the permanent certification program for health information technology, including changing the program's name to the ONC HIT Certification Program.

Shape-morphing composites with designed micro-architectures

NASA Astrophysics Data System (ADS)

Rodriguez, Jennifer N.; Zhu, Cheng; Duoss, Eric B.; Wilson, Thomas S.; Spadaccini, Christopher M.; Lewicki, James P.

2016-06-01

Shape memory polymers (SMPs) are attractive materials due to their unique mechanical properties, including high deformation capacity and shape recovery. SMPs are easier to process, lightweight, and inexpensive compared to their metallic counterparts, shape memory alloys. However, SMPs are limited to relatively small form factors due to their low recovery stresses. Lightweight, micro-architected composite SMPs may overcome these size limitations and offer the ability to combine functional properties (e.g., electrical conductivity) with shape memory behavior. Fabrication of 3D SMP thermoset structures via traditional manufacturing methods is challenging, especially for designs that are composed of multiple materials within porous microarchitectures designed for specific shape change strategies, e.g. sequential shape recovery. We report thermoset SMP composite inks containing some materials from renewable resources that can be 3D printed into complex, multi-material architectures that exhibit programmable shape changes with temperature and time. Through addition of fiber-based fillers, we demonstrate printing of electrically conductive SMPs where multiple shape states may induce functional changes in a device and that shape changes can be actuated via heating of printed composites. The ability of SMPs to recover their original shapes will be advantageous for a broad range of applications, including medical, aerospace, and robotic devices.

Dosimetric intercomparison of permanent Ho-166 seed's implants and HDR Ir-192 brachytherapy in breast cancer.

PubMed

de Campos, Tarcisio Passos Ribeiro; Nogueira, Luciana Batista; Trindade, Bruno; Cuperschmid, Ethel Mizrahy

2016-01-01

To provide a comparative dosimetric analysis of permanent implants of Ho(166)-seeds and temporary HDR Ir(192)-brachytherapy through computational simulation. Brachytherapy with Ir(192)-HDR or LDR based on temporary wires or permanent radioactive seed implants can be used as dose reinforcement for breast radiation therapy. Permanent breast implants have not been a practical clinical routine; although, I(125) and Pd(103)-seeds have already been reported. Biodegradable Ho(166)-ceramic-seeds have been addressed recently. Simulations of implants of nine Ho(166)-seeds and equivalent with HDR Ir(192)-brachytherapy were elaborated in MCNP5, shaped in a computational multivoxel simulator which reproduced a female thorax phantom. Spatial dose rate distributions and dose-volume histograms were generated. Protocol's analysis involving exposure time, seed's activities and dose were performed. Permanent Ho(166)-seed implants presented a maximum dose rate per unit of contained activity (MDR) of 1.1601 μGy h(-1) Bq(-1); and, a normalized MDR in standard points (8 mm, equidistant to 03-seeds - SP1, 10 mm - SP2) of 1.0% (SP1) and 0.5% (SP2), respectively. Ir(192)-brachytherapy presented MDR of 4.3945 × 10(-3) μGy h(-1) Bq(-1); and, 30% (SP1), and 20% (SP2). Therefore, seed's implant activities of 333 MBq (Ho(166)) and 259 GBq (Ir(192)) produced prescribed doses of 58 Gy (SP1; 5d) and 56 Gy (SP1, 5 fractions, 6 min), respectively. Breast Ho(166)-implants of 37-111 MBq are attractive due to the high dose rate near 6-10 mm from seeds, equivalent to Ir(192)-brachytherapy of 259 GBq (3 fractions, 6 min) providing similar dose in standard points at a week; however, with spatial dose distribution better confined. The seed positioning can be adjusted for controlling the breast tumor, in stages I and II, in flat and deep tumors, without any breast volumetric limitation.

Effects of alignment on the roll-over shapes of prosthetic feet.

PubMed

Hansen, Andrew

2008-12-01

Recent work suggests that a prosthetic ankle-foot component's roll-over shape - the effective rocker it conforms to between initial contact and opposite initial contact (the 'roll-over' interval of walking) - is closely linked to its final alignment in the prosthesis (as determined by a skilled prosthetist using heuristic techniques). If true, this information may help to determine the appropriate alignment for a lower limb prosthesis before it is built, or a priori. Knowledge is needed for future models that will incorporate the roll-over shape including the relative effect of alignment on the roll-over shape's radius of curvature and arc length. The purpose of this study was to evaluate the hypotheses that: (i) Changes in prosthesis alignment alter the position and orientation of a foot's roll-over shape in prosthesis-based coordinates, and (ii) these changes occur without changing the radius of curvature or arc length of the roll-over shape. To examine the hypotheses, this study examined the effects of nine alignment settings on the roll-over shapes of two prosthetic feet. The idea that alignment changes move and rotate roll-over shapes of prosthetic feet in prosthesis coordinates is supported by this work, but the hypothesis that the radius of curvature and arc length do not change for different alignments is not strongly supported by the data. A revised approach is presented that explains some of the changes to the roll-over shape parameters due to changes in rotational alignment.

Ontogenetic scaling of caudal fin shape in Squalus acanthias (Chondrichthyes, Elasmobranchii): a geometric morphometric analysis with implications for caudal fin functional morphology.

PubMed

Reiss, Katie L; Bonnan, Matthew F

2010-07-01

The shark heterocercal caudal fin and its contribution to locomotion are of interest to biologists and paleontologists. Current hydrodynamic data show that the stiff dorsal lobe leads the ventral lobe, both lobes of the tail are synchronized during propulsion, and tail shape reflects its overall locomotor function. Given the difficulties surrounding the analysis of shark caudal fins in vivo, little is known about changes in tail shape related to ontogeny and sex in sharks. A quantifiable analysis of caudal fin shape may provide an acceptable proxy for inferring gross functional morphology where direct testing is difficult or impossible. We examined ontogenetic and sex-related shape changes in the caudal fins of 115 Squalus acanthias museum specimens, to test the hypothesis that significant shape changes in the caudal fin shape occur with increasing size and between the sexes. Using linear and geometric morphometrics, we examined caudal shape changes within the context of current hydrodynamic models. We found no statistically significant linear or shape difference between sexes, and near-isometric scaling trends for caudal dimensions. These results suggest that lift and thrust increase linearly with size and caudal span. Thin-plate splines results showed a significant allometric shape change associated with size and caudal span: the dorsal lobe elongates and narrows, whereas the ventral lobe broadens and expands ventrally. Our data suggest a combination of caudal fin morphology with other body morphology aspects, would refine, and better elucidate the hydrodynamic factors (if any) that underlie the significant shape changes we report here for S. acanthias.

Transformation of synaptic vesicle phenotype in the intramedullary axonal arbors of cat spinal motoneurons following peripheral nerve injury.

PubMed

Havton, L A; Kellerth, J O

2001-08-01

Permanent transection of a peripheral motor nerve induces a gradual elimination of whole axon collateral systems in the axotomized spinal motoneurons. There is also an initial concurrent decrease in the amount of recurrent inhibition exerted by these arbors in the spinal cord for up to 6 weeks after the injury, whereas the same reflex action returns to normal by the 12-week postoperative state. The aim of the present investigation was to study the fine structure of the intramedullary axonal arbors of axotomized alpha-motoneurons in the adult cat spinal cord following a permanent peripheral motor nerve lesion. For this purpose, single axotomized alpha-motoneurons were labeled intracellularly with horseradish peroxidase at 12 weeks after permanent transection of their peripheral motor nerve. The intramedullary portions of their motor axon and axon collateral arbors were first reconstructed at the light microscopic level and subsequently studied ultrastructurally. This study shows that the synaptic contacts made by the intramedullary axon collateral arbors of axotomized motoneurons have undergone a change in synaptic vesicle ultrastructure from spherical and clear vesicles to spherical and dense-cored vesicles at 12 weeks after the transection of their peripheral axons. We suggest that the present transformation in synaptic vesicle fine structure may also correspond to a change in the contents of these boutons. This may, in turn, be responsible for the strengthening and recovery of the recurrent inhibitory reflex action exerted by the axotomized spinal motoneurons following a prolonged permanent motor nerve injury.

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.

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.

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

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.

Objections to tubal sterilization: what reversibility can and cannot overcome.

PubMed

Shain, R N

1980-09-01

In a study of 1074 women, 696 and 338 subjects would not seriously consider permanent and hypothetically reversible sterilization, respectively; they were asked to explain their feelings. The reason accounting for most objections to permanent sterilization (65%) was irreversibility and of the subjects who would not consider reversible sterilization or were unsure, 42.7% attributed their principal objection to unnecessary surgery, a factor at least currently intrinsic to the procedure and not readily overcome by education. Many of the remaining objections to both permanent and reversible sterilization may be amenable to change either through education or financial subsidies. In response to a question concerning female attractiveness subsequent to permanent sterilization, 3% of the sample felt attractiveness would decrease and 17.5% were unsure of the surgery's effect. Unsure responses were largely negative in character. This issue is important because of its relationship to intention to undergo sterilization. Upon consideration of reversible sterilization, negative and unsure responses significantly declined, even on the part of those women whose friends have had a poor experience with currently available procedures. Thus, whereas the option of reversibility cannot overcome objections to surgery, it does overcome those regarding permanency; moreover, the "temporary" character it bestows upon surgical sterilization appears to help certain individuals overcome their fears of losing their physical appeal as a result of such procedures.

Strain-Detecting Composite Materials

NASA Technical Reports Server (NTRS)

Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

2016-01-01

A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

Fertility control using intrauterine devices: an alternative for population control in wild horses.

PubMed

Daels, P F; Hughes, J P

1995-10-01

The purpose of this study was to develop a contraceptive method for feral horses. The feral horse population has increased significantly in recent years despite attempts to control numbers. As in most wild animal population control programs, contraceptive methods must be easy to apply, cause minimal disruption to the social structure and be fully reversible. In the present study, we tested the effectiveness of an intrauterine device (IUD) for fertility control in mares. Six mares were fitted with a silastic O-ring-shaped IUD on July 1 of Year 1. The IUD-treated mares were turned out with 12 nontreated mares and a fertile stallion in a large pasture until October 20 (112 d). None of the IUD-treated mares and all the nontreated mares became pregnant. The IUD-treated mares were maintained separately from the stallion during the winter. Following removal of the IUD on April 27 of Year 2, the mares were again introduced to the pasture with the stallion together with 6 nontreated mares. For the 6 mares previously treated with an IUD, the mean interval from introduction to the stallion to conception was 17.5 +/- 5 d or 1.3 cycles per pregnancy, and all mares produced a normal foal at term. Subsequently, 19 recorded mare breeding seasons resulted in 18 foals. Uterine cytology and histopathology indicate that the IUD causes mild chronic endometritis without permanent changes in the endometrium. We conclude that based on our observations, the O-ring-shaped IUD is an effective, safe and practical contraceptive method for mares.

Twenty-five years of vegetation change along a putative successional chronosequence on the Tanana River, Alaska

Treesearch

Teresa N. Hollingsworth; Andrea H. Lloyd; Dana R. Nossov; Roger W. Ruess; Brian A. Charlton; Knut Kielland

2010-01-01

Along the Tanana River floodplain, several turning points have been suggested to characterize the changes in ecosystem structure and function that accompany plant community changes through primary succession. In the past, much of tills research focused on a presumed chronosequence that uses space for time substitutions. Within this chronosequence, permanent vegetation...

19 CFR 111.30 - Notification of change of business address, organization, name, or location of business records...

Code of Federal Regulations, 2010 CFR

2010-04-01

... broker and changes his non-business mailing address, he must give written notice of the new address in... Bulletin. (e) Custody of records. Upon the permanent termination of a brokerage business, written... 19 Customs Duties 1 2010-04-01 2010-04-01 false Notification of change of business address...

Estimating postfire changes in production and value of Northern Rocky Mountain-Intermountain rangelands

Treesearch

David L. Peterson; Patrick J. Flowers

1984-01-01

A simulation model was developed to estimate postfire changes in the production and value of grazing lands in the Northern Rocky Mountain-Intermountain region. Ecological information and management decisions were used to simulate expected changes in production and value after wildfire in six major rangeland types: permanent forested range (ponderosa pine), transitory...

SPIN–SPIN COUPLING IN THE SOLAR SYSTEM

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

Batygin, Konstantin; Morbidelli, Alessandro, E-mail: kbatygin@gps.caltech.edu

The richness of dynamical behavior exhibited by the rotational states of various solar system objects has driven significant advances in the theoretical understanding of their evolutionary histories. An important factor that determines whether a given object is prone to exhibiting non-trivial rotational evolution is the extent to which such an object can maintain a permanent aspheroidal shape, meaning that exotic behavior is far more common among the small body populations of the solar system. Gravitationally bound binary objects constitute a substantial fraction of asteroidal and TNO populations, comprising systems of triaxial satellites that orbit permanently deformed central bodies. In thismore » work, we explore the rotational evolution of such systems with specific emphasis on quadrupole–quadrupole interactions, and show that for closely orbiting, highly deformed objects, both prograde and retrograde spin–spin resonances naturally arise. Subsequently, we derive capture probabilities for leading order commensurabilities and apply our results to the illustrative examples of (87) Sylvia and (216) Kleopatra asteroid systems. Cumulatively, our results suggest that spin–spin coupling may be consequential for highly elongated, tightly orbiting binary objects.« less

Rapid Assessment of the Ce-Co-Fe-Cu System for Permanent Magnetic Applications

DOE PAGES

Meng, F.; Chaudhary, R. P.; Gandha, K.; ...

2018-04-23

Here, this work focuses on the rapid synthesis and characterization of quaternary Ce(CoFeCu) 5 alloy libraries to assess their potential viability as permanent magnets. Arrays of bulk specimens with controlled compositions were synthesized via laser engineered net shaping (LENS) by feeding different ratios of alloy powders into a melt pool created by a laser. Based on the assessment of the magnetic properties of the LENS printed samples, arc-melted and cast ingots were prepared with varying Fe (5–20 at.%) and Co (60–45 at.%) compositions while maintaining constant Ce (16 at.%) and Cu (19 at.%) content. The evolution of the microstructure andmore » phases with varying chemical compositions and their dependence on magnetic properties are analyzed in as-cast and heat-treated samples. In both the LENS printed and cast samples, we find the best magnetic properties correspond to a predominantly single-phase Ce(CoFeCu) 5 microstructure in which high coercivity ( H c > 10 kOe) can be achieved without any microstructural refinement.« less

Rapid Assessment of the Ce-Co-Fe-Cu System for Permanent Magnetic Applications

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

Meng, F.; Chaudhary, R. P.; Gandha, K.

Here, this work focuses on the rapid synthesis and characterization of quaternary Ce(CoFeCu) 5 alloy libraries to assess their potential viability as permanent magnets. Arrays of bulk specimens with controlled compositions were synthesized via laser engineered net shaping (LENS) by feeding different ratios of alloy powders into a melt pool created by a laser. Based on the assessment of the magnetic properties of the LENS printed samples, arc-melted and cast ingots were prepared with varying Fe (5–20 at.%) and Co (60–45 at.%) compositions while maintaining constant Ce (16 at.%) and Cu (19 at.%) content. The evolution of the microstructure andmore » phases with varying chemical compositions and their dependence on magnetic properties are analyzed in as-cast and heat-treated samples. In both the LENS printed and cast samples, we find the best magnetic properties correspond to a predominantly single-phase Ce(CoFeCu) 5 microstructure in which high coercivity ( H c > 10 kOe) can be achieved without any microstructural refinement.« less

Permanent Mold Casting of JIS-AC4C Aluminum Alloy Using a Low-Temperature Mold

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

Yamagata, Hiroshi; Nikawa, Makoto

2011-01-17

Permanent mold casting using mold temperatures below 200 deg. C was conducted to obtain a high-strength, thin-walled casting. Al-7.36 mass% Si -0.18 Cu- 0.27Mg-0.34Fe alloy JIS-AC4C was cast using a bottom pouring cast plan. The product had a rectangular tube shape (70 mm W x 68 mm D x 180 mm H) with wall thicknesses of 1, 3 and 5 mm. The effect of heat insulation at the melt path was compared when using a sand runner insert and when using a steel runner insert as well as a powder mold release agent. Fine microstructures were observed in the casting.more » The smaller the thickness, the higher the hardness with smaller secondary dendrite arm spacing (SDAS). However, the hardness and the SDAS were unaffected by the mold temperature. It was proposed that the avoidance of the formation of primary {alpha} dendrite at the melt path generates a higher strength casting with adequate mold filling.« less

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

PubMed Central

Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2015-01-01

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles. PMID:26221197

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet.

PubMed

Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2015-07-01

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles.

A detailed X-ray investigation of ζ Puppis. IV. Further characterization of the variability

NASA Astrophysics Data System (ADS)

Nazé, Yaël; Ramiaramanantsoa, Tahina; Stevens, Ian R.; Howarth, Ian D.; Moffat, Anthony F. J.

2018-01-01

Context. One of the optically brightest and closest massive stars, ζ Pup, is also a bright X-ray source. Previously, its X-ray emission was found to be variable with light curves harbouring "trends" with a typical timescale longer than the exposure length, i.e. >1 d. The origin of these changes was proposed to be linked to large-scale structures in the wind of ζ Pup, but further characterization of the variability at high energies was needed to investigate this scenario. Aims: Since the previous papers of this series, a number of new X-ray observations have become available. Furthermore, a cyclic behaviour with a 1.78 d period was identified in long optical photometric runs, which is thought to be associated with the launching mechanism of large-scale wind structures. Methods: We analysed these new X-ray data, revisited the old data, and compared the X-ray light curves with the optical data, notably those taken simultaneously. Results: The behaviour of ζ Pup in X-rays cannot be explained in terms of a perfect clock because the amplitude and shape of its variations change with time. For example, ζ Pup was much more strongly variable between 2007 and 2011 than before and after this interval. Comparing the X-ray spectra of the star at maximum and minimum brightness yields no compelling difference beyond the overall flux change: the temperatures, absorptions, and line shapes seem to remain constant, well within errors. The only common feature between X-ray datasets is that the variation amplitudes appear maximum in the medium (0.6-1.2 keV) energy band. Finally, no clear and coherent correlation can be found between simultaneous X-ray and optical data. Only a subgroup of observations may be combined coherently with the optical period of 1.78 d, although the simultaneous optical behaviour is unknown. Conclusions: The currently available data do not reveal any obvious, permanent, and direct correlation between X-ray and optical variations. The origin of the X-ray variability therefore still needs to be ascertained, highlighting the need for long-term monitoring in multiwavelengths, i.e. X-ray, UV, and optical.

Trial Vocal Fold Injection Predicts Thyroplasty Outcomes in Nonparalytic Glottic Incompetence.

PubMed

Dumberger, Lukas D; Overton, Lewis; Buckmire, Robert A; Shah, Rupali N

2017-04-01

Trial vocal fold injection (TVFI) may be used prior to permanent medialization when voice outcome is uncertain. We aimed to determine whether voice outcomes of TVFI are predictive of, or correlate with outcomes after type I Gore-Tex medialization thyroplasty (GMT) in patients with nonparalytic glottic incompetence (GI). Thirty-five patients with nonparalytic GI who underwent TVFI followed by GMT were retrospectively reviewed. Change in voice-related quality of life (VRQOL) after TVFI was compared to change in VRQOL 3 to 9 months after GMT. Similar comparisons were made for change in glottal function index (GFI) and change in grade, roughness, breathiness, asthenia, and strain (GRBAS). Sample correlation coefficients were calculated. Change in VRQOL after TVFI showed good correlation with change in VRQOL after GMT, r = 0.55. Change in GFI after TVFI showed strong correlation with change in GFI after GMT, r = 0.74. Change in GRBAS after TVFI showed excellent correlation with change in GRBAS after GMT, r = 0.90. The TVFI is a useful tool in nonparalytic GI when outcomes from glottic closure procedures are not clear. Voice outcome measures after TVFI strongly correlate with outcomes from GMT. These data may be used to more confidently counsel patients regarding their predicted outcomes of permanent medialization.

Transgenerational Epigenetics: The Role of Maternal Effects in Cardiovascular Development

PubMed Central

Ho, Dao H.

2014-01-01

Transgenerational epigenetics, the study of non-genetic transfer of information from one generation to the next, has gained much attention in the past few decades due to the fact that, in many instances, epigenetic processes outweigh direct genetic processes in the manifestation of aberrant phenotypes across several generations. Maternal effects, or the influences of maternal environment, phenotype, and/or genotype on offsprings’ phenotypes, independently of the offsprings’ genotypes, are a subcategory of transgenerational epigenetics. Due to the intimate role of the mother during early development in animals, there is much interest in investigating the means by which maternal effects can shape the individual. Maternal effects are responsible for cellular organization, determination of the body axis, initiation and maturation of organ systems, and physiological performance of a wide variety of species and biological systems. The cardiovascular system is the first to become functional and can significantly influence the development of other organ systems. Thus, it is important to elucidate the role of maternal effects in cardiovascular development, and to understand its impact on adult cardiovascular health. Topics to be addressed include: (1) how and when do maternal effects change the developmental trajectory of the cardiovascular system to permanently alter the adult’s cardiovascular phenotype, (2) what molecular mechanisms have been associated with maternally induced cardiovascular phenotypes, and (3) what are the evolutionary implications of maternally mediated changes in cardiovascular phenotype? PMID:24813463

Neck Proprioception Shapes Body Orientation and Perception of Motion

PubMed Central

Pettorossi, Vito Enrico; Schieppati, Marco

2014-01-01

This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead (SSA), and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers. We first remind the early findings on human balance, gait trajectory, SSA, induced by limb, and neck muscle vibration. Then, more recent findings on self-motion perception of vestibular origin are described. The use of a vestibular asymmetric yaw-rotation stimulus for emphasizing the proprioceptive modulation of motion perception from the neck is mentioned. In addition, an attempt has been made to conjointly discuss the effects of unilateral neck proprioception on motion perception, SSA, and walking trajectory. Neck vibration also induces persistent aftereffects on the SSA and on self-motion perception of vestibular origin. These perceptive effects depend on intensity, duration, side of the conditioning vibratory stimulation, and on muscle status. These effects can be maintained for hours when prolonged high-frequency vibration is superimposed on muscle contraction. Overall, this brief outline emphasizes the contribution of neck muscle inflow to the construction and fine-tuning of perception of body orientation and motion. Furthermore, it indicates that tonic neck-proprioceptive input may induce persistent influences on the subject’s mental representation of space. These plastic changes might adapt motion sensitiveness to lasting or permanent head positional or motor changes. PMID:25414660

Neck proprioception shapes body orientation and perception of motion.

PubMed

Pettorossi, Vito Enrico; Schieppati, Marco

2014-01-01

This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead (SSA), and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers. We first remind the early findings on human balance, gait trajectory, SSA, induced by limb, and neck muscle vibration. Then, more recent findings on self-motion perception of vestibular origin are described. The use of a vestibular asymmetric yaw-rotation stimulus for emphasizing the proprioceptive modulation of motion perception from the neck is mentioned. In addition, an attempt has been made to conjointly discuss the effects of unilateral neck proprioception on motion perception, SSA, and walking trajectory. Neck vibration also induces persistent aftereffects on the SSA and on self-motion perception of vestibular origin. These perceptive effects depend on intensity, duration, side of the conditioning vibratory stimulation, and on muscle status. These effects can be maintained for hours when prolonged high-frequency vibration is superimposed on muscle contraction. Overall, this brief outline emphasizes the contribution of neck muscle inflow to the construction and fine-tuning of perception of body orientation and motion. Furthermore, it indicates that tonic neck-proprioceptive input may induce persistent influences on the subject's mental representation of space. These plastic changes might adapt motion sensitiveness to lasting or permanent head positional or motor changes.

Root length in the permanent teeth of women with an additional X chromosome (47,XXX females).

PubMed

Lähdesmäki, Raija E; Alvesalo, Lassi J

2010-07-01

Previous studies have demonstrated differential effects of the X and Y chromosomes on dental development. The expression of sexual dimorphism in terms of tooth size, shape, number and developmental timing has been explained especially by Y chromosome influence. The Y chromosome promotes enamel, crown and root dentin development. The X chromosome has an effect on enamel deposition. The aim of this research is to study the influence of the extra X chromosome on the development of permanent tooth root length. The study subjects (all of whom were from the Kvantti Dental Research Project) were seven 47,XXX females, five female relatives and 51 and 52 population control men and women, respectively. Measurements were made from panoramic radiographs on available permanent teeth by a digital calliper according to established procedures. The results showed that the maxillary root lengths of the 47,XXX females were of the same magnitude as those in normal women, but the mandibular root lengths were longer in 47,XXX females than in normal men or women. Increased enamel thickness in the teeth of 47,XXX females is apparently caused by the active enamel gene in all X chromosomes having no increased influence on crown dentin formation. These results in 47,XXX females indicate an increase in root dentin development, at least in the mandible, which together with the data on crown formation reflects a continuous long-lasting effect of the X chromosome on dental development.

Sweeping Changes in Immigration Law

ERIC Educational Resources Information Center

Danilov, Dan P.

1978-01-01

Among the changes in Immigration Laws are the rectification of the long-standing inequity between the Eastern and Western Hemispheres by instituting identical preference systems, the provision for the adjustment from a non-immigrant visa status to that of a permanent resident, and amendments to the Labor Certification requirements. (NQ)

75 FR 66316 - National Historical Publications and Records Commission Grants

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-28

... Office of Management and Budget (OMB) requirement to use Standard Form (SF) 425, Federal Financial Report... changes from the Office of Management and Budget; others proposed changes to eligible applicants and the... policy or to provide procedural details. Historical records means documentary material having permanent...

Permanent draft genome sequence of Vibrio tubiashii strain NCIMB 1337 (ATCC19106).

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

Temperton, B.; Thomas, S.; Tait, K.

2011-01-01

Vibrio tubiashii NCIMB 1337 is a major and increasingly prevalent pathogen of bivalve mollusks, and shares a close phylogenetic relationship with both V. orientalis and V. coralliilyticus. It is a Gram-negative, curved rod-shaped bacterium, originally isolated from a moribund juvenile oyster, and is both oxidase and catalase positive. It is capable of growth under both aerobic and anaerobic conditions. Here we describe the features of this organism, together with the draft genome and annotation. The genome is 5,353,266 bp long, consisting of two chromosomes, and contains 4,864 protein-coding and 86 RNA genes.

Optical Isolators With Transverse Magnets

NASA Technical Reports Server (NTRS)

Fan, Yuan X.; Byer, Robert L.

1991-01-01

New design for isolator includes zigzag, forward-and-backward-pass beam path and use of transverse rather than longitudinal magnetic field. Design choices produce isolator with as large an aperture as desired using low-Verdet-constant glass rather than more expensive crystals. Uses commercially available permanent magnets in Faraday rotator. More compact and less expensive. Designed to transmit rectangular beam. Square cross section of beam extended to rectangular shape by increasing one dimension of glass without having to increase magnetic field. Potentially useful in laser systems involving slab lasers and amplifiers. Has applications to study of very-high-power lasers for fusion research.

Modal Identification Experiment accommodations review

NASA Technical Reports Server (NTRS)

Klich, Phillip J.; Stillwagen, Frederic H.; Mutton, Philip

1994-01-01

The Modal Identification Experiment (MIE) will monitor the structure of the Space Station Freedom (SSF), and measure its response to a sequence of induced disturbances. The MIE will determine the frequency, damping, and shape of the important modes during the SSF assembly sequence including the Permanently Manned Configuration. This paper describes the accommodations for the proposed instrumentation, the data processing hardware, and the communications data rates. An overview of the MIE operational modes for measuring SSF acceleration forces with accelerometers is presented. The SSF instrumentation channel allocations and the Data Management System (DMS) services required for MIE are also discussed.

Multiple supernumerary teeth associated with an impacted maxillary central incisor: Surgical and orthodontic management

PubMed Central

Yeluri, Ramakrishna; Hegde, Manjunath; Baliga, Sudhindra; Munshi, Autar Krishen

2012-01-01

Various anomalies in the size, shape, number, structure and eruption of the teeth are often observed clinical conditions. Supernumerary teeth can be found in almost any region of the dental arch, and most of the times they are asymptomatic, and are routinely found during radiographic evaluation. The most common cause of impacted maxillary incisors is the presence of the supernumerary teeth. This paper describes a case of multiple supernumerary teeth associated with an impacted permanent maxillary central incisor in an 11-year old child along with its surgical and orthodontic management. PMID:22919229

Development of Interior Permanent Magnet Motors with Concentrated Windings for Reducing Magnet Eddy Current Loss

NASA Astrophysics Data System (ADS)

Yamazaki, Katsumi; Kanou, Yuji; Fukushima, Yu; Ohki, Shunji; Nezu, Akira; Ikemi, Takeshi; Mizokami, Ryoichi

In this paper, we present the development of interior magnet motors with concentrated windings, which reduce the eddy current loss of the magnets. First, the mechanism of the magnet eddy current loss generation is investigated by a simple linear magnetic circuit. Due to the consideration, an automatic optimization method using an adaptive finite element method is carried out to determine the stator and rotor shapes, which decrease the eddy current loss of the magnet. The determined stator and rotor are manufactured in order to proof the effectiveness by the measurement.

Buildings Change Detection Based on Shape Matching for Multi-Resolution Remote Sensing Imagery

NASA Astrophysics Data System (ADS)

Abdessetar, M.; Zhong, Y.

2017-09-01

Buildings change detection has the ability to quantify the temporal effect, on urban area, for urban evolution study or damage assessment in disaster cases. In this context, changes analysis might involve the utilization of the available satellite images with different resolutions for quick responses. In this paper, to avoid using traditional method with image resampling outcomes and salt-pepper effect, building change detection based on shape matching is proposed for multi-resolution remote sensing images. Since the object's shape can be extracted from remote sensing imagery and the shapes of corresponding objects in multi-scale images are similar, it is practical for detecting buildings changes in multi-scale imagery using shape analysis. Therefore, the proposed methodology can deal with different pixel size for identifying new and demolished buildings in urban area using geometric properties of objects of interest. After rectifying the desired multi-dates and multi-resolutions images, by image to image registration with optimal RMS value, objects based image classification is performed to extract buildings shape from the images. Next, Centroid-Coincident Matching is conducted, on the extracted building shapes, based on the Euclidean distance measurement between shapes centroid (from shape T0 to shape T1 and vice versa), in order to define corresponding building objects. Then, New and Demolished buildings are identified based on the obtained distances those are greater than RMS value (No match in the same location).

Shape-morphing composites with designed micro-architectures

DOE PAGES

Rodriguez, Jennifer N.; Zhu, Cheng; Duoss, Eric B.; ...

2016-06-15

Shape memory polymers (SMPs) are attractive materials due to their unique mechanical properties, including high deformation capacity and shape recovery. SMPs are easier to process, lightweight, and inexpensive compared to their metallic counterparts, shape memory alloys. However, SMPs are limited to relatively small form factors due to their low recovery stresses. Lightweight, micro-architected composite SMPs may overcome these size limitations and offer the ability to combine functional properties (e.g., electrical conductivity) with shape memory behavior. Fabrication of 3D SMP thermoset structures via traditional manufacturing methods is challenging, especially for designs that are composed of multiple materials within porous microarchitectures designedmore » for specific shape change strategies, e.g. sequential shape recovery. We report thermoset SMP composite inks containing some materials from renewable resources that can be 3D printed into complex, multi-material architectures that exhibit programmable shape changes with temperature and time. Through addition of fiber-based fillers, we demonstrate printing of electrically conductive SMPs where multiple shape states may induce functional changes in a device and that shape changes can be actuated via heating of printed composites. As a result, the ability of SMPs to recover their original shapes will be advantageous for a broad range of applications, including medical, aerospace, and robotic devices.« less

High-definition optical coherence tomography and reflectance confocal microscopy in the in vivo visualization of a reaction to permanent make-up.

PubMed

Maier, T; Flaig, M J; Ruzicka, T; Berking, C; Pavicic, T

2015-03-01

After permanent make-up treatments, eczematous and granulomatous reactions may occur which need anti-inflammatory treatment. For the definite diagnosis oftentimes biopsies are recommended. In vivo imaging such as reflectance confocal microscopy (RCM) and high-definition optical coherence tomography (HD-OCT) has been successfully used in the non-invasive diagnosis of various dermatoses before. Here, we report on non-invasive imaging of a reaction towards permanent make-up in a 40-year-old woman by using HD-OCT and RCM. Both in HD-OCT and in RCM subepidermal pigment and granulomatous changes could be visualized and correlated with the histopathological findings. Regression of the lesions in response to topical steroids and intralesional injections of steroids and 5-fluorouracil is reported and treatment options are discussed. Non-invasive imaging techniques such as HD-OCT and RCM allow the visualization and localization of exogenous pigment and help in the evaluation of adverse reactions due to permanent make-up tattooing. © 2014 European Academy of Dermatology and Venereology.

Dermabrasion

MedlinePlus

... your expectations. Talk with your doctor about your motivations and expectations, as well as the potential risks. ... 12 months to prevent permanent changes in skin color. If dark skin coloring is a concern after ...

DNA sequence-directed shape change of photopatterned hydrogels via high-degree swelling

NASA Astrophysics Data System (ADS)

Cangialosi, Angelo; Yoon, ChangKyu; Liu, Jiayu; Huang, Qi; Guo, Jingkai; Nguyen, Thao D.; Gracias, David H.; Schulman, Rebecca

2017-09-01

Shape-changing hydrogels that can bend, twist, or actuate in response to external stimuli are critical to soft robots, programmable matter, and smart medicine. Shape change in hydrogels has been induced by global cues, including temperature, light, or pH. Here we demonstrate that specific DNA molecules can induce 100-fold volumetric hydrogel expansion by successive extension of cross-links. We photopattern up to centimeter-sized gels containing multiple domains that undergo different shape changes in response to different DNA sequences. Experiments and simulations suggest a simple design rule for controlled shape change. Because DNA molecules can be coupled to molecular sensors, amplifiers, and logic circuits, this strategy introduces the possibility of building soft devices that respond to diverse biochemical inputs and autonomously implement chemical control programs.

Object Permanence After a 24-Hr Delay and Leaving the Locale of Disappearance: The Role of Memory, Space, and Identity

PubMed Central

Moore, M. Keith; Meltzoff, Andrew N.

2005-01-01

Fourteen-month-old infants saw an object hidden inside a container and were removed from the disappearance locale for 24 hr. Upon their return, they searched correctly for the hidden object, demonstrating object permanence and long-term memory. Control infants who saw no disappearance did not search. In Experiment 2, infants returned to see the container either in the same or a different room. Performance by room-change infants dropped to baseline levels, suggesting that infant search for hidden objects is guided by numerical identity. Infants seek the individual object that disappeared, which exists in its original location, not in a different room. A new behavior, identity-verifying search, was discovered and quantified. Implications are drawn for memory, spatial understanding, object permanence, and object identity. PMID:15238047

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.

Object permanence after a 24-hr delay and leaving the locale of disappearance: the role of memory, space, and identity.

PubMed

Moore, M Keith; Meltzoff, Andrew N

2004-07-01

Fourteen-month-old infants saw an object hidden inside a container and were removed from the disappearance locale for 24 hr. Upon their return, they searched correctly for the hidden object, demonstrating object permanence and long-term memory. Control infants who saw no disappearance did not search. In Experiment 2, infants returned to see the container either in the same or a different room. Performance by room-change infants dropped to baseline levels, suggesting that infant search for hidden objects is guided by numerical identity. Infants seek the individual object that disappeared, which exists in its original location, not in a different room. A new behavior, identity-verifying search, was discovered and quantified. Implications are drawn for memory, spatial understanding, object permanence, and object identity. Copyright 2004 APA, all rights reserved

Electric vehicle traction motors - The development of an advanced motor concept

NASA Technical Reports Server (NTRS)

Campbell, P.

1980-01-01

An axial-field permanent magnet traction motor is described, similar to several advanced motors that are being developed in the United States. This type of machine has several advantages over conventional dc motors, particularly in the electric vehicle application. The rapidly changing cost of magnetic materials, particularly cobalt, makes it important to study the utilization of permanent magnet materials in such machines. The impact of different magnets on machine design is evaluated, and the advantages of using iron powder composites in the armature are assessed.

75 FR 45661 - Notice of Permanent Closure on Public Lands in Ada County, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-03

...On April 12, 2010, Higby Cave and all public lands within 1,000 feet of the entrance were permanently closed to vehicle access and public use at all times, due to changes in the cave's structural integrity and related potential hazards. The cave entrance has been gated and access limited to BLM-permitted and administrative activities. Exempt from this order are BLM employees, authorized permittees, and other Federal, State and County employees while on official business of their respective agencies, including associated vehicle use for administrative and emergency purposes.

Is there any change in the prevalence of intestinal and urinary parasitosis among "non-permanent resident" students in Tunisia ?

PubMed

Trabelsi, Sonia; Bouchakoua, Myiram; Aouinet, Amira; Sellami, Amira; Khaled, Samira

2012-07-01

Intestinal parasitosis are cosmopolitan affections, often related to the fecal peril. However urinary bilharziosis is a disease eliminated in Tunisia. As part of monitoring the emergence and re-emergence of intestinal parasitosis and urinary bilharziasis, foreign students benefit from parasitological systematic monitoring stool and urine during their enrollment to the University. To study the prevalence of various intestinal parasitosis and urinary bilharziasis among non permanent resident students in Tunisia. A retrospective survey was carried at the Laboratory of Parasitology- Mycology of Charles Nicolle Hospital of Tunis during the inscription period of 6 university years 2005-2010. 328 students profited from a parasitological examination of stool and urine. 144 students (43.9%) harbored intestinal parasites. More than one parasite was detected in 69 students (47.9%). Intestinal protozoa were the majority of identified parasites (96.9%). 9.7% of identified parasites were pathogenic. Three cases (0.91%) of urinary bilharziasis were diagnosed. The prevalence of intestinal and urinary parasitism among the "non-permanent residents" students in Tunisia has not changed. This justifies a systematic parasitologic monitoring for students coming from areas of high endemicity of parasitosis in order to avoid the introduction of these.

Transition from Nondestructive Testing (NDT) to Structural Health Monitoring (SHM): potential and challenges (presentation video)

NASA Astrophysics Data System (ADS)

Cawley, Peter

2014-03-01

There is a gradual shift in emphasis from periodic inspection with detachable transducers (NDT) to permanently installed monitoring systems giving information about the structural integrity at pre-programmed intervals or on demand (SHM). The drivers of this change are discussed, together with the requirements of successful SHM systems. Particular issues are that NDT often involves scanning and this is not possible with typical SHM configurations; it therefore becomes important to cover a significant area of structure from each transducer position. Guided waves provide a possible solution to this problem and permanently installed guided wave pipe inspection systems are now available. The sensitivity obtained with a permanently installed system is significantly better than that in a one-off test as baseline subtraction can be employed. However, this is far from trivial as it is necessary to compensate for benign changes such as temperature. The guided wave technique does not provide accurate remaining thickness information and is best complemented by point measurements at selected locations. Another issue is that the SHM transducers must survive in operational conditions, which is particularly difficult at high temperatures. Recent work at Imperial College and associated spin-out companies on solutions to these problems is discussed.

10 CFR 50.74 - Notification of change in operator or senior operator status.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Notification of change in operator or senior operator... or senior operator status. Each licensee shall notify the appropriate Regional Administrator as... operator or senior operator: (a) Permanent reassignment from the position for which the licensee has...

Change in area and ownership of private timberland in western Oregon between 1961-1962 and 1973-1976.

Treesearch

Donald R. Gedney

1981-01-01

A reinventory in 1973-76 of permanent inventory plots established in 1961-62 on western Oregon's forest industry and other private timberland provides data by ownership of timberland losses to nonforest land uses and changes in private ownership of timberland between inventories.

Rare Species (RS)

Treesearch

Steve Sutherland

2006-01-01

The FIREMON Rare Species (RS) method is used to assess changes in uncommon, perennial plant species when other monitoring methods are not effective. This method monitors individual plants and statistically quantifies changes in plant survivorship, growth, and reproduction over time. Plants are spatially located using distance along and from a permanent baseline, and...

76 FR 7500 - Indian Trust Management Reform-Implementation of Statutory Changes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-10

... changes also affect the purchase of small fractional interests at probate by restricting who may purchase without consent and what interests may be purchased without consent. DATES: This interim final rule is.... Purchase at Probate B. Permanent Improvements 1. Rule of Descent When Decedent Died Intestate 2...

An improved glycerin-jelly mounting procedure for permanent preparations of helminth eggs.

PubMed

Kumagai, M; Inaba, T; Makioka, A; Ishiwata, K; Onishi, K; Watanabe, N

2010-04-01

Many attempts have been undertaken to make permanent preparations of helminth eggs. However, the resulting preparations either lacked durability or tended to deform thin-shelled eggs, such as those of the hookworm. To overcome these drawbacks, we have modified 2 aspects of the glycerin-jelly mounting procedure. First, we gradually changed the media in which the helminth eggs soaked, from 10% formalin via water to a 70% ethanol and 5% glycerin solution. It took 10 days, which is much longer than the time required for the processes previously reported. Second, we used a hole slide glass instead of a slide glass. Eggs of 11 species of helminths have been prepared with this procedure, and have kept their morphology without apparent change for more than 4 yr.

Planform, aero-structural, and flight control optimization for tailless morphing aircraft

NASA Astrophysics Data System (ADS)

Molinari, Giulio; Arrieta, Andres F.; Ermanni, Paolo

2015-04-01

Tailless airplanes with swept wings rely on variations of the spanwise lift distribution to provide controllability in roll, pitch and yaw. Conventionally, this is achieved utilizing multiple control surfaces, such as elevons, on the wing trailing edge. As every flight condition requires different control moments (e.g. to provide pitching moment equilibrium), these surfaces are practically permanently displaced. Due to their nature, causing discontinuities, corners and gaps, they bear aerodynamic penalties, mostly in terms of shape drag. Shape adaptation, by means of chordwise morphing, has the potential of varying the lift of a wing section by deforming its profile in a way that minimizes the resulting drag. Furthermore, as the shape can be varied differently along the wingspan, the lift distribution can be tailored to each specific flight condition. For this reason, tailless aircraft appear as a prime choice to apply morphing techniques, as the attainable benefits are potentially significant. In this work, we present a methodology to determine the optimal planform, profile shape, and morphing structure for a tailless aircraft. The employed morphing concept is based on a distributed compliance structure, actuated by Macro Fiber Composite (MFC) piezoelectric elements. The multidisciplinary optimization is performed considering the static and dynamic aeroelastic behavior of the resulting structure. The goal is the maximization of the aerodynamic efficiency while guaranteeing the controllability of the plane, by means of morphing, in a set of flight conditions.

Preliminary study on magnetic tracking-based planar shape sensing and navigation for flexible surgical robots in transoral surgery: methods and phantom experiments.

PubMed

Song, Shuang; Zhang, Changchun; Liu, Li; Meng, Max Q-H

2018-02-01

Flexible surgical robot can work in confined and complex environments, which makes it a good option for minimally invasive surgery. In order to utilize flexible manipulators in complicated and constrained surgical environments, it is of great significance to monitor the position and shape of the curvilinear manipulator in real time during the procedures. In this paper, we propose a magnetic tracking-based planar shape sensing and navigation system for flexible surgical robots in the transoral surgery. The system can provide the real-time tip position and shape information of the robot during the operation. We use wire-driven flexible robot to serve as the manipulator. It has three degrees of freedom. A permanent magnet is mounted at the distal end of the robot. Its magnetic field can be sensed with a magnetic sensor array. Therefore, position and orientation of the tip can be estimated utilizing a tracking method. A shape sensing algorithm is then carried out to estimate the real-time shape based on the tip pose. With the tip pose and shape display in the 3D reconstructed CT model, navigation can be achieved. Using the proposed system, we carried out planar navigation experiments on a skull phantom to touch three different target positions under the navigation of the skull display interface. During the experiments, the real-time shape has been well monitored and distance errors between the robot tip and the targets in the skull have been recorded. The mean navigation error is [Formula: see text] mm, while the maximum error is 3.2 mm. The proposed method provides the advantages that no sensors are needed to mount on the robot and no line-of-sight problem. Experimental results verified the feasibility of the proposed method.

Changes in area and ownership of timberland in western Oregon: 1961-86.

Treesearch

Colin D. MacLean

1990-01-01

This report notes the changes in timberland area and in timberland ownership that took place in western Oregon between 1961 and 1986. The data for the report were based on observations and measurements taken during three successive forest inventories of non-Federal lands in western Oregon. Estimates of change were based on repeat measurements of 1,465 permanent plots...

Environmental Disaster and Economic Change: Do tropical cyclones have permanent effects on economic growth and structure?

NASA Astrophysics Data System (ADS)

Jina, A.; von der Goltz, J.; Hsiang, S. M.

2011-12-01

Natural disasters have important, often devastating, effects upon economic growth and well-being. Due to this, disasters have become an active area of recent research and policy attention. However, much of this research has been narrowly focused, relying on anecdotal evidence and aggregated data to support conclusions about disaster impacts in the short-term. Employing a new global data set of tropical cyclone exposure from 1960 to 2008, we investigate in greater detail whether permanent changes in economic performance and structure can result from these extreme events in some cases. Our macro-economic analyses use the World Development Indicator dataset and have shown promising results: there are dramatic long-term economic transformations associated with tropical cyclones across a number of countries and industries. This effect is most clearly seen in Small Island Developing States (SIDS) and some countries in Latin America, where negative changes in long-term growth trends are observed in the years following a large tropical cyclone. In many economies with a high exposure to tropical cyclone damage, there are noticeable structural changes within the economy. The impacts of disasters might be expressed through various economic and social channels, through direct loss of lives and infrastructure damage; for instance, the destruction of infrastructure such as ports may damage export opportunities where replacement capital is not readily available. These structural changes may have far-reaching implications for economic growth and welfare. Larger nations subjected to the impacts of tropical cyclones are thought to be able to relocate economically important activities that are damaged by cyclones, and so long-term trend changes are not observed, even for events that cause a large immediate decrease in national productivity. By investigating in a more rigorous fashion the hypothesis that the environment triggers these permanent economic changes, our work has implications for the conceptual foundations of both economic theory and sustainable development.

Combining color and shape information for illumination-viewpoint invariant object recognition.

PubMed

Diplaros, Aristeidis; Gevers, Theo; Patras, Ioannis

2006-01-01

In this paper, we propose a new scheme that merges color- and shape-invariant information for object recognition. To obtain robustness against photometric changes, color-invariant derivatives are computed first. Color invariance is an important aspect of any object recognition scheme, as color changes considerably with the variation in illumination, object pose, and camera viewpoint. These color invariant derivatives are then used to obtain similarity invariant shape descriptors. Shape invariance is equally important as, under a change in camera viewpoint and object pose, the shape of a rigid object undergoes a perspective projection on the image plane. Then, the color and shape invariants are combined in a multidimensional color-shape context which is subsequently used as an index. As the indexing scheme makes use of a color-shape invariant context, it provides a high-discriminative information cue robust against varying imaging conditions. The matching function of the color-shape context allows for fast recognition, even in the presence of object occlusion and cluttering. From the experimental results, it is shown that the method recognizes rigid objects with high accuracy in 3-D complex scenes and is robust against changing illumination, camera viewpoint, object pose, and noise.

Non-linear and plastic soil response from strong ground motion detected using the ambient seismic field

NASA Astrophysics Data System (ADS)

Viens, L.; Denolle, M.; Hirata, N.

2017-12-01

Strong ground motion can induce dynamic strains large enough for the shallow subsurface to respond non-linearly and cause permanent velocity changes during earthquakes. We investigate the behavior of the near-surface in the Tokyo metropolitan area during the 2011 Mw 9.0 Tohoku-Oki earthquake using continuous records from 234 seismometers of the Metropolitan Seismic Observation network (MeSO-net). This network, which was deployed in shallow 20-m depth boreholes, recorded horizontal accelerations up to 236 cm/s2 during the mainshock. For each MeSO-net station, we compute the near-surface response using the single-station cross-correlation technique between vertical and horizontal components, every 6 hours for 2.5 months around the main event. Comparing each near-surface response against the pre-event reference, we find seismic velocity drops up to 10% in the near-surface of the Tokyo metropolitan area during the mainshock. The amplitude of the coseismic velocity drop increases with increasing ground shaking and decreasing VS30, which is the S-wave velocity the first 30-m of the ground. Furthermore, the waveforms experience a loss of coherence that recovers exponentially over a time. This recovery rate also increases with the acceleration levels. While most of the velocity changes and waveform coherence recover within a few days, we also find permanent changes at stations that experienced liquefaction and the strongest ground motions. The ambient seismic field captures the coseismic velocity changes in the shallow structure and the following healing process, and may be used to detect permanent damage.

Effect of shape and size of lung and chest wall on stresses in the lung

NASA Technical Reports Server (NTRS)

Vawter, D. L.; Matthews, F. L.; West, J. B.

1975-01-01

To understand better the effect of shape and size of lung and chest wall on the distribution of stresses, strains, and surface pressures, we analyzed a theoretical model using the technique of finite elements. First we investigated the effects of changing the chest wall shape during expansion, and second we studied lungs of a variety of inherent shapes and sizes. We found that, in general, the distributions of alveolar size, mechanical stresses, and surface pressures in the lungs were dominated by the weight of the lung and that changing the shape of the lung or chest wall had relatively little effect. Only at high states of expansion where the lung was very stiff did changing the shape of the chest wall cause substantial changes. Altering the inherent shape of the lung generally had little effect but the topographical differences in stresses and surface pressures were approximately proportional to lung height. The results are generally consistent with those found in the dog by Hoppin et al (1969).

Analysis of change in timber volume on non-Federal timberlands in Washington.

Treesearch

Daniel D. Oswald

1986-01-01

This report presents the findings of a study conducted to determine change in per acre timber volume on non-Federal timberlands in Washington from the mid-1960’s to 1978-80. The basis for the-study was the measurement of 1,576 permanent plots at two occasions. The study findings include estimates of change in volume and of the components of change-growth, mortality,...

A new intratracheal stent made from nitinol, an alloy with "shape memory effect".

PubMed

Vinograd, I; Klin, B; Brosh, T; Weinberg, M; Flomenblit, Y; Nevo, Z

1994-05-01

Temporary or permanent tracheal splinting in pediatric patients may be indicated in tracheomalacia or bronchomalacia, repair of congenital tracheal stenosis, and after tracheal resection. This study presents the results of the development of a new intraluminal airway stent made from titanium alloy, a metal with "shape memory effect". At low temperatures (martensitic state) the titanium alloy stent can be fashioned into a specific shape; then when heated to a higher temperature (austenitic state) the stent alters its shape, only to regain its original shape when recooled to the lower temperature. The stent, connected to a small electric power supply, was introduced into 20 young rabbits with the use of a 2.5 cm rigid bronchoscope. After implantation in the martensitic state the stent was warmed to 40 degrees C, the austenitic state, by an electric current of 1.5 to 3 ampere for 1 to 2 seconds. After a period of 8 to 10 weeks the stent was removed (in its martensitic state) through the same-sized bronchoscope after being cooled with 3 to 4 ml of 80% alcohol solution at 6 degrees C. No signs of airway obstruction developed in any of the animals after implantation or extraction of the stent. The biomechanical properties of the trachea, as shown by strain measurements with the use of incremental forces, showed significant differences between the stented and unstented segments (p < 0.005). The titanium alloy intratracheal stent adequately fulfilled the requirements of a temporary intraluminal airway splint, and because of its unique feature of shape memory effect the stent could be inserted, fixed, and removed easily, even in very small airways.

Deconstructing cartilage shape and size into contributions from embryogenesis, metamorphosis, and tadpole and frog growth.

PubMed

Rose, Christopher S; Murawinski, Danny; Horne, Virginia

2015-06-01

Understanding skeletal diversification involves knowing not only how skeletal rudiments are shaped embryonically, but also how skeletal shape changes throughout life. The pharyngeal arch (PA) skeleton of metamorphosing amphibians persists largely as cartilage and undergoes two phases of development (embryogenesis and metamorphosis) and two phases of growth (larval and post-metamorphic). Though embryogenesis and metamorphosis produce species-specific features of PA cartilage shape, the extents to which shape and size change during growth and metamorphosis remain unaddressed. This study uses allometric equations and thin-plate spline, relative warp and elliptic Fourier analyses to describe shape and size trajectories for the ventral PA cartilages of the frog Xenopus laevis in tadpole and frog growth and metamorphosis. Cartilage sizes scale negatively with body size in both growth phases and cartilage shapes scale isometrically or close to it. This implies that most species-specific aspects of cartilage shape arise in embryogenesis and metamorphosis. Contributions from growth are limited to minor changes in lower jaw (LJ) curvature that produce relative gape narrowing and widening in tadpoles and frogs, respectively, and most cartilages becoming relatively thinner. Metamorphosis involves previously unreported decreases in cartilage size as well as changes in cartilage shape. The LJ becomes slightly longer, narrower and more curved, and the adult ceratohyal emerges from deep within the resorbing tadpole ceratohyal. This contrast in shape and size changes suggests a fundamental difference in the underlying cellular pathways. The observation that variation in PA cartilage shape decreases with tadpole growth supports the hypothesis that isometric growth is required for the metamorphic remodeling of PA cartilages. It also supports the existence of shape-regulating mechanisms that are specific to PA cartilages and that resist local adaptation and phenotypic plasticity. © 2015 Anatomical Society.

Deconstructing cartilage shape and size into contributions from embryogenesis, metamorphosis, and tadpole and frog growth

PubMed Central

Rose, Christopher S; Murawinski, Danny; Horne, Virginia

2015-01-01

Understanding skeletal diversification involves knowing not only how skeletal rudiments are shaped embryonically, but also how skeletal shape changes throughout life. The pharyngeal arch (PA) skeleton of metamorphosing amphibians persists largely as cartilage and undergoes two phases of development (embryogenesis and metamorphosis) and two phases of growth (larval and post-metamorphic). Though embryogenesis and metamorphosis produce species-specific features of PA cartilage shape, the extents to which shape and size change during growth and metamorphosis remain unaddressed. This study uses allometric equations and thin-plate spline, relative warp and elliptic Fourier analyses to describe shape and size trajectories for the ventral PA cartilages of the frog Xenopus laevis in tadpole and frog growth and metamorphosis. Cartilage sizes scale negatively with body size in both growth phases and cartilage shapes scale isometrically or close to it. This implies that most species-specific aspects of cartilage shape arise in embryogenesis and metamorphosis. Contributions from growth are limited to minor changes in lower jaw (LJ) curvature that produce relative gape narrowing and widening in tadpoles and frogs, respectively, and most cartilages becoming relatively thinner. Metamorphosis involves previously unreported decreases in cartilage size as well as changes in cartilage shape. The LJ becomes slightly longer, narrower and more curved, and the adult ceratohyal emerges from deep within the resorbing tadpole ceratohyal. This contrast in shape and size changes suggests a fundamental difference in the underlying cellular pathways. The observation that variation in PA cartilage shape decreases with tadpole growth supports the hypothesis that isometric growth is required for the metamorphic remodeling of PA cartilages. It also supports the existence of shape-regulating mechanisms that are specific to PA cartilages and that resist local adaptation and phenotypic plasticity. PMID:25913729

Sensitization of a stray-field NMR to vibrations: a potential for MR elastometry with a portable NMR sensor.

PubMed

Mastikhin, Igor; Barnhill, Marie

2014-11-01

An NMR signal from a sample in a constant stray field of a portable NMR sensor is sensitized to vibrations. The CPMG sequence is synchronized to vibrations so that the constant gradient becomes an "effective" square-wave gradient, leading to the vibration-induced phase accumulation. The integrating nature of the spot measurement, combined with the phase distribution due to a non-uniform gradient and/or a wave field, leads to a destructive interference, the drop in the signal intensity and changes in the echo train shape. Vibrations with amplitudes as small as 140 nm were reliably detected with the permanent gradient of 12.4 T/m. The signal intensity depends on the phase offset between the vibrations and the pulse sequence. This approach opens the way for performing elastometry and micro-rheology measurements with portable NMR devices beyond the walls of a laboratory. Even without synchronization, if a vibration frequency is comparable to 1/2TE of the CPMG sequence, the signal can be severely affected, making it important for potential industrial applications of stray-field NMR. Copyright © 2014 Elsevier Inc. All rights reserved.

A Point Spread Function for the EPOXI Mission

NASA Technical Reports Server (NTRS)

Barry, Richard K.

2010-01-01

The Extrasolar Planet Observation Characterization and the Deep Impact Extended Investigation missions (EPOXI) are currently observing the transits of exoplanets, two comet nuclei at short range, and the Earth and Mars using the High Resolution Instrument (HRI) - a 0.3 m f/35 telescope on the Deep Impact probe. The HRI is in a permanently defocused state with the instrument pOint of focus about 0.6 cm before the focal plane due to the use of a reference flat mirror that took a power during ground thermal-vacuum testing. Consequently, the point spread function (PSF) covers approximately nine pixels FWHM and is characterized by a patch with three-fold symmetry due to the three-point support structures of the primary and secondary mirrors. The PSF is also strongly color dependent varying in shape and size with change in filtration and target color. While defocus is highly desirable for exoplanet transit observations to limit sensitivity to intra-pixel variation, it is suboptimal for observations of spatially resolved targets. Consequently, all images used in our analysis of such objects were deconvolved with an instrument PSF. The instrument PSF is also being used to optimize transit analysis. We discuss development and usage of an instrument PSF for these observations.