Induction heating using induction coils in series-parallel circuits

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

Matsen, Marc Rollo; Geren, William Preston; Miller, Robert James

A part is inductively heated by multiple, self-regulating induction coil circuits having susceptors, coupled together in parallel and in series with an AC power supply. Each of the circuits includes a tuning capacitor that tunes the circuit to resonate at the frequency of AC power supply.

AC loss modelling and experiment of two types of low-inductance solenoidal coils

NASA Astrophysics Data System (ADS)

Liang, Fei; Yuan, Weijia; Zhang, Min; Zhang, Zhenyu; Li, Jianwei; Venuturumilli, Sriharsha; Patel, Jay

2016-11-01

Low-inductance solenoidal coils, which usually refer to the nonintersecting type and the braid type, have already been employed to build superconducting fault current limiters because of their fast recovery and low inductance characteristics. However, despite their usage there is still no systematical simulation work concerning the AC loss characteristics of the coils built with 2G high temperature superconducting tapes perhaps because of their complicated structure. In this paper, a new method is proposed to simulate both types of coils with 2D axisymmetric models solved by H formulation. Following the simulation work, AC losses of both types of low inductance solenoidal coils are compared numerically and experimentally, which verify that the model works well in simulating non-inductive coils. Finally, simulation works show that pitch has significant impact to AC loss of both types of coils and the inter-layer separation has different impact to the AC loss of braid type of coil in case of different applied currents. The model provides an effective tool for the design optimisation of SFCLs built with non-inductive solenoidal coils.

Introducing AC inductive reactance with a power tool

NASA Astrophysics Data System (ADS)

Bryant, Wesley; Baker, Blane

2016-09-01

The concept of reactance in AC electrical circuits is often non-intuitive and difficult for students to grasp. In order to address this lack of conceptual understanding, classroom exercises compare the predicted resistance of a power tool, based on electrical specifications, to measured resistance. Once students discover that measured resistance is smaller than expected, they are asked to explain these observations using previously studied principles of magnetic induction. Exercises also introduce the notion of inductive reactance and impedance in AC circuits and, ultimately, determine self-inductance of the motor windings within the power tool.

Dual-level regulation of ACC synthase activity by MPK3/MPK6 cascade and its downstream WRKY transcription factor during ethylene induction in Arabidopsis.

PubMed

Li, Guojing; Meng, Xiangzong; Wang, Ruigang; Mao, Guohong; Han, Ling; Liu, Yidong; Zhang, Shuqun

2012-06-01

Plants under pathogen attack produce high levels of ethylene, which plays important roles in plant immunity. Previously, we reported the involvement of ACS2 and ACS6, two Type I ACS isoforms, in Botrytis cinerea-induced ethylene biosynthesis and their regulation at the protein stability level by MPK3 and MPK6, two Arabidopsis pathogen-responsive mitogen-activated protein kinases (MAPKs). The residual ethylene induction in the acs2/acs6 double mutant suggests the involvement of additional ACS isoforms. It is also known that a subset of ACS genes, including ACS6, is transcriptionally induced in plants under stress or pathogen attack. However, the importance of ACS gene activation and the regulatory mechanism(s) are not clear. In this report, we demonstrate using genetic analysis that ACS7 and ACS11, two Type III ACS isoforms, and ACS8, a Type II ACS isoform, also contribute to the B. cinerea-induced ethylene production. In addition to post-translational regulation, transcriptional activation of the ACS genes also plays a critical role in sustaining high levels of ethylene induction. Interestingly, MPK3 and MPK6 not only control the stability of ACS2 and ACS6 proteins via direct protein phosphorylation but also regulate the expression of ACS2 and ACS6 genes. WRKY33, another MPK3/MPK6 substrate, is involved in the MPK3/MPK6-induced ACS2/ACS6 gene expression based on genetic analyses. Furthermore, chromatin-immunoprecipitation assay reveals the direct binding of WRKY33 to the W-boxes in the promoters of ACS2 and ACS6 genes in vivo, suggesting that WRKY33 is directly involved in the activation of ACS2 and ACS6 expression downstream of MPK3/MPK6 cascade in response to pathogen invasion. Regulation of ACS activity by MPK3/MPK6 at both transcriptional and protein stability levels plays a key role in determining the kinetics and magnitude of ethylene induction.

Control of power to an inductively heated part

DOEpatents

Adkins, Douglas R.; Frost, Charles A.; Kahle, Philip M.; Kelley, J. Bruce; Stanton, Suzanne L.

1997-01-01

A process for induction hardening a part to a desired depth with an AC signal applied to the part from a closely coupled induction coil includes measuring the voltage of the AC signal at the coil and the current passing through the coil; and controlling the depth of hardening of the part from the measured voltage and current. The control system determines parameters of the part that are functions of applied voltage and current to the induction coil, and uses a neural network to control the application of the AC signal based on the detected functions for each part.

Control of power to an inductively heated part

DOEpatents

Adkins, D.R.; Frost, C.A.; Kahle, P.M.; Kelley, J.B.; Stanton, S.L.

1997-05-20

A process for induction hardening a part to a desired depth with an AC signal applied to the part from a closely coupled induction coil includes measuring the voltage of the AC signal at the coil and the current passing through the coil; and controlling the depth of hardening of the part from the measured voltage and current. The control system determines parameters of the part that are functions of applied voltage and current to the induction coil, and uses a neural network to control the application of the AC signal based on the detected functions for each part. 6 figs.

Onboard power line conditioning system for an electric or hybrid vehicle

DOEpatents

Kajouke, Lateef A.; Perisic, Milun

2016-06-14

A power line quality conditioning system for a vehicle includes an onboard rechargeable direct current (DC) energy storage system and an onboard electrical system coupled to the energy storage system. The energy storage system provides DC energy to drive an electric traction motor of the vehicle. The electrical system operates in a charging mode such that alternating current (AC) energy from a power grid external to the vehicle is converted to DC energy to charge the DC energy storage system. The electrical system also operates in a vehicle-to-grid power conditioning mode such that DC energy from the DC energy storage system is converted to AC energy to condition an AC voltage of the power grid.

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.

The protein phosphatase 2A catalytic subunit StPP2Ac2b acts as a positive regulator of tuberization induction in Solanum tuberosum L.

PubMed

Muñiz García, María Noelia; Muro, María Catalina; Mazzocchi, Luciana Carla; País, Silvia Marina; Stritzler, Margarita; Schlesinger, Mariana; Capiati, Daniela Andrea

2017-02-01

This study provides the first genetic evidence for the role of PP2A in tuberization, demonstrating that the catalytic subunit StPP2Ac2b positively modulates tuber induction, and that its function is related to the regulation of gibberellic acid metabolism. The results contribute to a better understanding of the molecular mechanism controlling tuberization induction, which remains largely unknown. The serine/threonine protein phosphatases type 2A (PP2A) are implicated in several physiological processes in plants, playing important roles in hormone responses. In cultivated potato (Solanum tuberosum), six PP2A catalytic subunits (StPP2Ac) were identified. The PP2Ac of the subfamily I (StPP2Ac1, 2a and 2b) were suggested to be involved in the tuberization signaling in leaves, where the environmental and hormonal signals are perceived and integrated. The aim of this study was to investigate the role of PP2A in the tuberization induction in stolons. We selected one of the catalytic subunits of the subfamily I, StPP2Ac2b, to develop transgenic plants overexpressing this gene (StPP2Ac2b-OE). Stolons from StPP2Ac2b-OE plants show higher tuber induction rates in vitro, as compared to wild type stolons, with no differences in the number of tubers obtained at the end of the process. This effect is accompanied by higher expression levels of the gibberellic acid (GA) catabolic enzyme StGA2ox1. GA up-regulates StPP2Ac2b expression in stolons, possibly as part of the feedback system by which the hormone regulates its own level. Sucrose, a tuber-promoting factor in vitro, increases StPP2Ac2b expression. We conclude that StPP2Ac2b acts in stolons as a positive regulator tuber induction, integrating different tuberization-related signals mainly though the modulation of GA metabolism.

Variable-frequency inverter controls torque, speed, and braking in ac induction motors

NASA Technical Reports Server (NTRS)

Nola, F. J.

1974-01-01

Dc to ac inverter provides optimum frequency and voltage to ac induction motor, in response to different motor-load and speed requirements. Inverter varies slip frequency of motor in proportion to required torque. Inverter protects motor from high current surges, controls negative slip to apply braking, and returns energy stored in momentum of load to dc power source.

Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae1[OPEN

PubMed Central

Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

2015-01-01

Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. PMID:26265775

Early histological, hormonal, and molecular changes during pineapple (Ananas comosus (L.) Merrill) artificial flowering induction.

PubMed

Espinosa, Maita Eulalia Ávila; Moreira, Rafael Oliveira; Lima, André Almeida; Ságio, Solange Aparecida; Barreto, Horllys Gomes; Luiz, Sara Lazara Pérez; Abreu, Carlos Eduardo Aragón; Yanes-Paz, Ermis; Ruíz, Yanelis Capdesuñer; González-Olmedo, Justo Lorenzo; Chalfun-Júnior, Antonio

2017-02-01

Natural flowering can cause serious scheduling problems in the pineapple (Ananas comosus) industry and increase harvest costs. Pineapple flowering is thought to be triggered by increased ethylene levels and artificial forcing of pineapple flowering is a common practice to promote flowering synchronisation. However, little is known about the early hormonal and molecular changes of pineapple flowering induction and development. Here, we aimed to analyse the molecular, hormonal, and histological changes during artificial pineapple flowering by Ethrel ® 48 treatment. Histological analyses of the shoot apical meristem, leaf gibberellic acid (GA 3 ), and ethylene quantification were carried out during the first 72h after Ethrel ® 48 treatment. Expression profiles from ethylene biosynthesis (AcACS2 and AcACO1), gibberellin metabolism (AcGA2-ox1 and AcDELLA1), and flower development (FT-like gene (AcFT), LFY-like gene (AcLFY), and a PISTILLATA-like gene (AcPI)) genes were analysed during the first 24h after Ethrel ® 48 treatment. Differentiation processes of the shoot apical meristem into flower buds were already present in the first 72h after Ethrel ® 48 treatment. Ethrel ® 48 lead to a reduction in GA 3 levels, probably triggered by elevated ethylene levels and the positive regulation AcGA2-ox1. AcLFY activation upon Ethrel ® 48 may also have contributed to the reduction of GA 3 levels and, along with the up-regulation of AcPI, are probably associated with the flower induction activation. AcFT and AcDELLA1 do not seem to be regulated by GA 3 and ethylene. Decreased GA 3 and increased ethylene levels suggest an accumulation of AcDELLA1, which may display an important role in pineapple flowering induction. Thus, this study shows that molecular, hormonal, and histological changes are present right after Ethrel ® 48 treatment, providing new insights into how pineapple flowering occurs under natural conditions. Copyright © 2016 Elsevier GmbH. All rights reserved.

Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae.

PubMed

Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

2015-09-01

Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. © 2015 American Society of Plant Biologists. All Rights Reserved.

New model of inverting substation for DC traction with regenerative braking system

NASA Astrophysics Data System (ADS)

Omar, Abdul Malek Saidina; Samat, Ahmad Asri Abd; Isa, Siti Sarah Mat; Shamsuddin, Sarah Addyani; Jamaludin, Nur Fadhilah; Khyasudeen, Muhammad Farris

2017-08-01

This paper presents a power electronic devices application focus on modeling, analysis, and control of switching power converter in the inverting DC substation with regenerative braking system which is used to recycle the surplus regenerative power by feed it back to the main AC grid. The main objective of this research is to improve the switching power electronic converter of the railway inverting substation and optimize the maximum kinetic energy recovery together with minimum power losses from the railway braking system. Assess performance including efficiency and robustness will be evaluated in order to get the best solution for the design configuration. Research methodology included mathematical calculation, simulation, and detail analysis on modeling of switching power converter on inverting substation. The design stage separates to four main areas include rectification mode, regenerative mode, control inverter mode and filtering mode. The simulation result has shown that the regenerative inverter has a capability to accept a maximum recovery power on the regeneration mode. Total energy recovery has increase and power losses have decreases because inverter abilities to transfer the surplus energy back to the main AC supply. An Inverter controller with PWM Generator and PI Voltage Regulator has been designed to control voltage magnitude and frequency of the DC traction system.

Generator voltage stabilisation for series-hybrid electric vehicles.

PubMed

Stewart, P; Gladwin, D; Stewart, J; Cowley, R

2008-04-01

This paper presents a controller for use in speed control of an internal combustion engine for series-hybrid electric vehicle applications. Particular reference is made to the stability of the rectified DC link voltage under load disturbance. In the system under consideration, the primary power source is a four-cylinder normally aspirated gasoline internal combustion engine, which is mechanically coupled to a three-phase permanent magnet AC generator. The generated AC voltage is subsequently rectified to supply a lead-acid battery, and permanent magnet traction motors via three-phase full bridge power electronic inverters. Two complementary performance objectives exist. Firstly to maintain the internal combustion engine at its optimal operating point, and secondly to supply a stable 42 V supply to the traction drive inverters. Achievement of these goals minimises the transient energy storage requirements at the DC link, with a consequent reduction in both weight and cost. These objectives imply constant velocity operation of the internal combustion engine under external load disturbances and changes in both operating conditions and vehicle speed set-points. An electronically operated throttle allows closed loop engine velocity control. System time delays and nonlinearities render closed loop control design extremely problematic. A model-based controller is designed and shown to be effective in controlling the DC link voltage, resulting in the well-conditioned operation of the hybrid vehicle.

Harmonic analysis of traction power supply system based on wavelet decomposition

NASA Astrophysics Data System (ADS)

Dun, Xiaohong

2018-05-01

With the rapid development of high-speed railway and heavy-haul transport, AC drive electric locomotive and EMU large-scale operation in the country on the ground, the electrified railway has become the main harmonic source of China's power grid. In response to this phenomenon, the need for timely monitoring of power quality problems of electrified railway, assessment and governance. Wavelet transform is developed on the basis of Fourier analysis, the basic idea comes from the harmonic analysis, with a rigorous theoretical model, which has inherited and developed the local thought of Garbor transformation, and has overcome the disadvantages such as window fixation and lack of discrete orthogonally, so as to become a more recently studied spectral analysis tool. The wavelet analysis takes the gradual and precise time domain step in the high frequency part so as to focus on any details of the signal being analyzed, thereby comprehensively analyzing the harmonics of the traction power supply system meanwhile use the pyramid algorithm to increase the speed of wavelet decomposition. The matlab simulation shows that the use of wavelet decomposition of the traction power supply system for harmonic spectrum analysis is effective.

Dynamometer Research Facilities | Wind | NREL

Science.gov Websites

drivetrains by replacing the rotor and blades of a turbine with a powerful motor. The National Renewable -horsepower variable-speed induction motor, with AC grid connections of 120, 240, and 480 volts (V) and a dynamometer features a 3,351-horsepower (hp), 415-amp AC induction motor with variable-frequency drive that

Power factor control system for AC induction motors

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1977-01-01

A power factor control system for use with ac induction motors was designed which samples lines voltage and current through the motor and decreases power input to the motor proportional to the detected phase displacement between current and voltage. This system provides, less power to the motor, as it is less loaded.

Regulation of N-nitrosodimethylamine demethylase in rat liver and kidney.

PubMed

Hong, J Y; Pan, J M; Dong, Z G; Ning, S M; Yang, C S

1987-11-15

In previous work, the low Km form of N-nitrosodimethylamine (NDMA) demethylase has been demonstrated to be due to a specific form of cytochrome P-450 (designated as P-450ac) and to be the enzyme required for the metabolic activation of NDMA. The present work deals with the regulation of P-450ac in rat liver during development as well as the mechanism of induction of P-450ac in rat liver and kidney by inducers. NDMA demethylase activity was almost undetectable in the liver of newborn rats, increased after day 4, and remained elevated throughout the first 17 days of the neonatal period. The enhancement of NDMA demethylase activity during development was accompanied by corresponding increases of P-450ac content and P-450ac mRNA levels as determined by Western and slot blot analyses, respectively. No sex differences with respect to this enzyme were observed in the developing rats. Acetone treatment on late-term pregnant rats for 2 days resulted in transplacental inductions of P-450ac and P-450ac mRNA in the newborn rats. Pretreatment of young male rats and adult female rats with acetone or isopropyl alcohol caused increases of NDMA demethylase activity and P-450ac content in the liver but no significant change in the P-450ac mRNA level. These facts suggest the possible existence of a posttranscription regulatory mechanism under these induction conditions. The presence of P-450ac in rat kidney was demonstrated by Western and Northern blot analyses. The renal form of P-450ac seemed to be regulated in a fashion similar to the hepatic P-450ac regarding its response to inducing factors such as fasting and acetone treatment.

AC losses in horizontally parallel HTS tapes for possible wireless power transfer applications

NASA Astrophysics Data System (ADS)

Shen, Boyang; Geng, Jianzhao; Zhang, Xiuchang; Fu, Lin; Li, Chao; Zhang, Heng; Dong, Qihuan; Ma, Jun; Gawith, James; Coombs, T. A.

2017-12-01

This paper presents the concept of using horizontally parallel HTS tapes with AC loss study, and the investigation on possible wireless power transfer (WPT) applications. An example of three parallel HTS tapes was proposed, whose AC loss study was carried out both from experiment using electrical method; and simulation using 2D H-formulation on the FEM platform of COMSOL Multiphysics. The electromagnetic induction around the three parallel tapes was monitored using COMSOL simulation. The electromagnetic induction and AC losses generated by a conventional three turn coil was simulated as well, and then compared to the case of three parallel tapes with the same AC transport current. The analysis demonstrates that HTS parallel tapes could be potentially used into wireless power transfer systems, which could have lower total AC losses than conventional HTS coils.

Electromagnetic Induction of Zerovalent Iron (ZVI) Powder and Nanoscale Zerovalent Iron (NZVI) Particles Enhances Dechlorination of Trichloroethylene in Contaminated Groundwater and Soil: Proof of Concept.

PubMed

Phenrat, Tanapon; Thongboot, Thippawan; Lowry, Gregory V

2016-01-19

This study evaluates the concept of using zerovalent iron (ZVI) powder or nanoscale zerovalent iron (NZVI) particles in combination with a low frequency (150 kHz) AC electromagnetic field (AC EMF) to effectively remove trichloroethylene (TCE) from groundwater and saturated soils. ZVI and NZVI are ferromagnetic, which can induce heat under applied AC EMF. The heat generated by ZVI and NZVI induction can increase the rate of dechlorination, according to Arrhenius' equation, and increase the rate of TCE desorption from TCE-sorbed soil. Both dechlorination and TCE desorption enhance the overall TCE removal rate. We evaluated this novel concept in laboratory batch reactors. We found that both ZVI and NZVI can induce heat under applied AC EMF up to 120 °C in 20 min. Using ZVI and NZVI with AC EMF enhanced dechlorination of dissolved TCE (no soil) up to 4.96-fold. In addition to increasing the temperature by ZVI and NZVI induction heating, AC EMF increased intrinsic ZVI and NZVI reactivity, ostensibly due to accelerated corrosion, as demonstrated by the increased ORP. In a soil-water-TCE system, NZVI together with AC EMF thermally enhanced desorption of TCE from soil and increased the degradation of TCE up to 5.36-fold compared to the absence of AC EMF. For the first time, this study indicates the potential for ZVI and NZVI coupled with AC EMF as a combined remediation technique for increasing the rate and completeness of in situ cleanup of adsorbed phase contaminants.

Forward and reverse control system for induction motors

DOEpatents

Wright, J.T.

1987-09-15

A control system for controlling the direction of rotation of a rotor of an induction motor includes an array of five triacs with one of the triacs applying a current of fixed phase to the windings of the rotor and four of the triacs being switchable to apply either hot ac current or return ac current to the stator windings so as to reverse the phase of current in the stator relative to that of the rotor and thereby reverse the direction of rotation of the rotor. Switching current phase in the stator is accomplished by operating the gates of pairs of the triacs so as to connect either hot ac current or return ac current to the input winding of the stator. 1 fig.

Systems and methods for deactivating a matrix converter

DOEpatents

Ransom, Ray M.

2013-04-02

Systems and methods are provided for deactivating a matrix conversion module. An electrical system comprises an alternating current (AC) interface, a matrix conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the matrix conversion module, and a control module. The control module is coupled to the matrix conversion module, and in response to a shutdown condition, the control module is configured to operate the matrix conversion module to deactivate the first conversion module when a magnitude of a current through the inductive element is less than a threshold value.

Hybrid-secondary uncluttered induction machine

DOEpatents

Hsu, John S.

2001-01-01

An uncluttered secondary induction machine (100) includes an uncluttered rotating transformer (66) which is mounted on the same shaft as the rotor (73) of the induction machine. Current in the rotor (73) is electrically connected to current in the rotor winding (67) of the transformer, which is not electrically connected to, but is magnetically coupled to, a stator secondary winding (40). The stator secondary winding (40) is alternately connected to an effective resistance (41), an AC source inverter (42) or a magnetic switch (43) to provide a cost effective slip-energy-controlled, adjustable speed, induction motor that operates over a wide speed range from below synchronous speed to above synchronous speed based on the AC line frequency fed to the stator.

Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

NASA Technical Reports Server (NTRS)

Peak, S. C.

1982-01-01

An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

Systems and methods for commutating inductor current using a matrix converter

DOEpatents

Ransom, Ray M; Kajouke, Lateef A; Perisic, Milun

2012-10-16

Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

Cost Performance Estimating Relationships for Hybrid Electric Vehicle Components

DTIC Science & Technology

2003-07-31

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

Ocriplasmin: who is the best candidate?

PubMed Central

Prospero Ponce, Claudia M; Stevenson, William; Gelman, Rachel; Agarwal, Daniel R; Christoforidis, John B

2016-01-01

Enzymatic vitreolysis is currently the focus of attention around the world for treating vitreomacular traction and full-thickness macular hole. Induction of posterior vitreous detachment is an active area of developmental clinical and basic research. Despite exerting an incompletely elucidated physiological effect, ocriplasmin (also known as microplasmin) has been recognized to serve as a well-tolerated intravitreal injection for the treatment of vitreomacular traction and full-thickness macular hole. There are several unexplored areas of intervention where enzymatic vitreolysis could potentially be used (ie, diabetic macular edema). Recent promising studies have included combinations of enzymatic approaches and new synthetic molecules that induce complete posterior vitreous detachment as well as antiangiogenesis. Although no guidelines have been proposed for the use of ocriplasmin, this review attempts to aid physicians in answering the most important question, “Who is the best candidate?” PMID:27051270

Characterization and snubbing of a bidirectional MCT in a resonant ac link converter

NASA Technical Reports Server (NTRS)

Lee, Tony; Elbuluk, Malik E.; Zinger, Donald S.

1993-01-01

The MOS-Controlled Thyristor (MCT) is emerging as a powerful switch that combines the better characteristics of existing power devices. A study of switching stresses on an MCT switch under zero voltage resonant switching is presented. The MCT is used as a bidirectional switch in an ac/ac pulse density modulated inverter for induction motor drive. Current and voltage spikes are observed and analyzed with variations in the timing of the switching. Different snubber circuit configurations are under investigation to minimize the effect of these transients. The results will be extended to study and test the MCT switching in a medium power (5 hp) induction motor drive.

Performance Analysis of Three-Phase Induction Motor with AC Direct and VFD

NASA Astrophysics Data System (ADS)

Kumar, Dinesh

2018-03-01

The electrical machine analysis and performance calculation is a very important aspect of efficient drive system design. The development of power electronics devices and power converters provide smooth speed control of Induction Motors by changing the frequency of input supply. These converters, on one hand are providing a more flexible speed control that also leads to problems of harmonics and their associated ailments like pulsating torque, distorted current and voltage waveforms, increasing losses etc. This paper includes the performance analysis of three phase induction motor with three-phase AC direct and variable frequency drives (VFD). The comparison has been concluded with respect to various parameters. MATLAB-SIMULINKTM is used for the analysis.

A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link

PubMed Central

Lee, Hyung-Min; Ghovanloo, Maysam

2014-01-01

A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35-μm 4-metal 2-poly standard CMOS process in 2.1 mm2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μF capacitors up to ±2 V in 420 μs, achieving a high measured charging efficiency of 82%. PMID:24678284

A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link.

PubMed

Lee, Hyung-Min; Ghovanloo, Maysam

2013-10-01

A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35- μ m 4-metal 2-poly standard CMOS process in 2.1 mm 2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μ F capacitors up to ±2 V in 420 μ s, achieving a high measured charging efficiency of 82%.

Power-Factor Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

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

Lee, Seong T; Burress, Timothy A; Hsu, John S

2009-01-01

This paper introduces a new method for calculating the power factor with consideration of the cross saturation between the direct-axis (d-axis) and the quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross-saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at highmore » speed, which was developed for the traction motor of a hybrid electric vehicle.« less

Compact, Low-Noise Magnetic Sensor with Fluxgate (DC) and Induction (AC) Modes of Operation

DTIC Science & Technology

2009-07-01

induction sensor and the fluxgate magnetometer . ......................................... 2 Figure 3.1 - Impulse response of a 4” long coil (#6...Block diagram of the Year 2, Task 2 fluxgate magnetometer . ................................... 6 Figure 3.3 - FIS-prototype magnetic-field...and demonstrated an innovative dual-mode, fluxgate -induction sensor (FIS) that combines a fluxgate magnetometer and an electromagnetic (EM) induction

Sugar Treatments Can Induce AcLEAFY COTYLEDON1 Expression and Trigger the Accumulation of Storage Products during Prothallus Development of Adiantum capillus-veneris

PubMed Central

Fang, Yu-Han; Li, Xia; Bai, Shu-Nong; Rao, Guang-Yuan

2017-01-01

A seed is an intricate structure. Of the two development processes involved in seed formation, seed maturation, or seed program includes accumulation of storage products, acquisition of desiccation tolerance, and induction of dormancy. Little is known about how these processes were originated and integrated into the life cycle of seed plants. While previous investigation on seed origin was almost exclusively through fossil comparison in paleobotany, a wealth of information about the key role of LEAFY COTYLEDON1 (LEC1) in seed formation of spermatophyte inspired a new approach to investigating the seed origin mystery. Here, we examined the expression pattern of AcLEC1 during the entire life cycle of Adiantum capillus-veneris, a non-seed plant, confirmed no AcLEC1 gene expression detectable in prothalli, demonstrated inductive expressed by both sucrose and glucose in prothalli. As expected, we found that sugar treatments delayed prothallus development, promoted differentiation of reproductive organs, and triggered accumulation of storage products. These findings demonstrated links between the sugar treatments and the induction of AcLEC1 expression, as well as the sugar treatments and the events such as accumulation of storage products, which is similar to those considered as seed maturation process in seed plants. These links support a modified hypothesis that inductive expression of LEC1 homologs during embryogenesis might be a key innovation for the origin of the seed program. PMID:28484470

An Efficient Fuzzy Controller Design for Parallel Connected Induction Motor Drives

NASA Astrophysics Data System (ADS)

Usha, S.; Subramani, C.

2018-04-01

Generally, an induction motors are highly non-linear and has a complex time varying dynamics. This makes the speed control of an induction motor a challenging issue in the industries. But, due to the recent trends in the power electronic devices and intelligent controllers, the speed control of the induction motor is achieved by including non-linear characteristics also. Conventionally a single inverter is used to run one induction motor in industries. In the traction applications, two or more inductions motors are operated in parallel to reduce the size and cost of induction motors. In this application, the parallel connected induction motors can be driven by a single inverter unit. The stability problems may introduce in the parallel operation under low speed operating conditions. Hence, the speed deviations should be reduce with help of suitable controllers. The speed control of the parallel connected system is performed by PID controller and fuzzy logic controller. In this paper the speed response of the induction motor for the rating of IHP, 1440 rpm, and 50Hz with these controller are compared in time domain specifications. The stability analysis of the system also performed under low speed using matlab platform. The hardware model is developed for speed control using fuzzy logic controller which exhibited superior performances over the other controller.

Electroporation of cells using EM induction of ac fields by a magnetic stimulator

NASA Astrophysics Data System (ADS)

Chen, C.; Evans, J. A.; Robinson, M. P.; Smye, S. W.; O'Toole, P.

2010-02-01

This paper describes a method of effectively electroporating mammalian cell membranes with pulsed alternating-current (ac) electric fields at field strengths of 30-160 kV m-1. Although many in vivo electroporation protocols entail applying square wave or monotonically decreasing pulses via needles or electrode plates, relatively few have explored the use of pulsed ac fields. Following our previous study, which established the effectiveness of ac fields for electroporating cell membranes, a primary/secondary coil system was constructed to produce sufficiently strong electric fields by electromagnetic induction. The primary coil was formed from the applicator of an established transcranial magnetic stimulation (TMS) system, while the secondary coil was a purpose-built device of a design which could eventually be implanted into tissue. The effects of field strength, pulse interval and cumulative exposure time were investigated using microscopy and flow cytometry. Results from experiments on concentrated cell suspensions showed an optimized electroporation efficiency of around 50%, demonstrating that electroporation can be practicably achieved by inducing such pulsed ac fields. This finding confirms the possibility of a wide range of in vivo applications based on magnetically coupled ac electroporation.

Optimum Construction of Heating Coil for Domestic Induction Cooker

NASA Astrophysics Data System (ADS)

Sinha, Dola; Bandyopadhyay, Atanu; Sadhu, Pradip Kumar; Pal, Nitai

2010-10-01

The design and optimization of the parameters of heating coil is very important for the analytical analysis of high frequency inverter fed induction cooker. Moreover, accurate prediction of high frequency winding loss (i.e., losses due to skin and proximity effects) is necessary as the induction cooker used in power electronics applications. At high frequency current penetration in the induction coil circuit is very difficult for conducting wire due to skin-effect. To eradicate the skin effect heating coil is made up of bundle conductor i.e., litz wire. In this paper inductances and AC resistances of a litz-wire are calculated and optimized by considering the input parameters like wire type, shape, number of strand, number of spiral turn, number of twist per feet of heating coil and operating frequency. A high frequency half bridge series resonant mirror inverter circuit is used in this paper and taking the optimum values of inductance and ac resistance the circuit is simulated through PSPICE simulations. It has been noticed that the results are feasible enough for real implementation.

Preliminary design of a Primary Loop Pump Assembly (PLPA), using electromagnetic pumps

NASA Technical Reports Server (NTRS)

Moss, T. A.; Matlin, G.; Donelan, L.; Johnson, J. L.; Rowe, I.

1972-01-01

A preliminary design study of flight-type dc conduction-permanent magnetic, ac helical induction, and ac linear induction pumps for circulating 883 K (1130 F) NaK at 9.1 kg/sec (20 lb/sec) is described. Various electromagnetic pump geometrics are evaluated against hydraulic performance, and the effects of multiple windings and numbers of pumps per assembly on overall reliability were determined. The methods used in the electrical-hydraulic, stress, and thermal analysis are discussed, and the high temperature electrical materials selected for the application are listed.

Advanced electric propulsion system concept for electric vehicles. Addendum 1: Voltage considerations

NASA Technical Reports Server (NTRS)

Raynard, A. E.; Forbes, F. E.

1980-01-01

The two electric vehicle propulsion systems that best met cost and performance goals were examined to assess the effect of battery pack voltage on system performance and cost. A voltage range of 54 to 540 V was considered for a typical battery pack capacity of 24 k W-hr. The highest battery specific energy (W-hr/kg) and the lowest cost ($/kW-hr) were obtained at the minimum voltage level. The flywheel system traction motor is a dc, mechanically commutated with shunt field control, and due to the flywheel the traction motor and the battery are not subject to extreme peaks of power demand. The basic system uses a permanent-magnet motor with electronic commutation supplied by an ac power control unit. In both systems battery cost were the major factor in system voltage selection, and a battery pack with the minimum voltage of 54 V produced the lowest life-cycle cost. The minimum life-cycle cost for the basic system with lead-acid batteries was $0.057/km and for the flywheel system was $0.037/km.

A transcription activator-like effector (TALE) induction system mediated by proteolysis.

PubMed

Copeland, Matthew F; Politz, Mark C; Johnson, Charles B; Markley, Andrew L; Pfleger, Brian F

2016-04-01

Simple and predictable trans-acting regulatory tools are needed in the fields of synthetic biology and metabolic engineering to build complex genetic circuits and optimize the levels of native and heterologous gene products. Transcription activator-like effectors (TALEs) are bacterial virulence factors that have recently gained traction in biotechnology applications owing to their customizable DNA-binding specificity. In this work we expanded the versatility of these transcription factors to create an inducible TALE system by inserting tobacco-etch virus (TEV) protease recognition sites into the TALE backbone. The resulting engineered TALEs maintain transcriptional repression of their target genes in Escherichia coli, but are degraded after induction of the TEV protease, thereby promoting expression of the previously repressed target gene of interest. This TALE-TEV technology enables both repression and induction of plasmid or chromosomal target genes in a manner analogous to traditional repressor proteins but with the added flexibility of being operator-agnostic.

A transcription activator-like effector induction system mediated by proteolysis

PubMed Central

Copeland, Matthew F.; Politz, Mark C.; Johnson, Charles B.; Markley, Andrew L.; Pfleger, Brian F.

2016-01-01

Simple and predictable trans-acting regulatory tools are needed in the fields of synthetic biology and metabolic engineering to build complex genetic circuits and optimize the levels of native and heterologous gene products. Transcription activator-like effectors (TALEs) are bacterial virulence factors that have recently gained traction in biotechnology applications due to their customizable DNA binding specificity. In this work we expand the versatility of these transcription factors to create an inducible TALE system by inserting tobacco-etch virus (TEV) protease recognition sites into the TALE backbone. The resulting engineered TALEs maintain transcriptional repression of their target genes in Escherichia coli, but are degraded following the induction of the TEV protease, thereby promoting expression of the previously repressed target gene of interest. This TALE-TEV technology enables both repression and induction of plasmid or chromosomal target genes in a manner analogous to traditional repressor proteins but with the added flexibility of being operator agnostic. PMID:26854666

Transistorized PWM inverter-induction motor drive system

NASA Technical Reports Server (NTRS)

Peak, S. C.; Plunkett, A. B.

1982-01-01

This paper describes the development of a transistorized PWM inverter-induction motor traction drive system. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and development of this inverter is the principal object of this paper. The high-speed induction motor is a design which is optimized for use with an inverter power source. The primary feedback control is a torque angle control with voltage and torque outer loop controls. A current-controlled PWM technique is used to control the motor voltage. The drive has a constant torque output with PWM operation to base motor speed and a constant horsepower output with square wave operation to maximum speed. The drive system was dynamometer tested and the results are presented.

Development and Test of an Eddy-Current Clutch-Propulsion System

DOT National Transportation Integrated Search

1973-10-01

This report covers the Phase 1 effort which is to develop and to test an/AC-propulsion system for personal rapid- transit vehicles. This propulsion system incorporates an AC-induction motor in conjunction with an eddy-current clutch and brake. Also i...

An MRI-Compatible High Frequency AC Resistive Heating System for Homeothermic Maintenance in Small Animals

PubMed Central

Gomes, Ana L.; Kinchesh, Paul; Kersemans, Veerle; Allen, Philip D.; Smart, Sean C.

2016-01-01

Purpose To develop an MRI-compatible resistive heater, using high frequency alternating current (AC), for temperature maintenance of anaesthetised animals. Materials and Methods An MRI-compatible resistive electrical heater was formed from narrow gauge wire connected to a high frequency (10–100 kHz) AC power source. Multiple gradient echo images covering a range of echo times, and pulse-acquire spectra were acquired with the wire heater powered using high frequency AC or DC power sources and without any current flowing in order to assess the sensitivity of the MRI acquisitions to the presence of current flow through the heater wire. The efficacy of temperature maintenance using the AC heater was assessed by measuring rectal temperature immediately following induction of general anaesthesia for a period of 30 minutes in three different mice. Results Images and spectra acquired in the presence and absence of 50–100 kHz AC through the wire heater were indistinguishable, whereas DC power created field shifts and lineshape distortions. Temperature lost during induction of anaesthesia was recovered within approximately 20 minutes and a stable temperature was reached as the mouse’s temperature approached the set target. Conclusion The AC-powered wire heater maintains adequate heat input to the animal to maintain body temperature, and does not compromise image quality. PMID:27806062

Induction of P-glycoprotein expression and activity by Aconitum alkaloids: Implication for clinical drug–drug interactions

PubMed Central

Wu, Jinjun; Lin, Na; Li, Fangyuan; Zhang, Guiyu; He, Shugui; Zhu, Yuanfeng; Ou, Rilan; Li, Na; Liu, Shuqiang; Feng, Lizhi; Liu, Liang; Liu, Zhongqiu; Lu, Linlin

2016-01-01

The Aconitum species, which mainly contain bioactive Aconitum alkaloids, are frequently administered concomitantly with other herbal medicines or chemical drugs in clinics. The potential risk of drug–drug interactions (DDIs) arising from co-administration of Aconitum alkaloids and other drugs against specific targets such as P-glycoprotein (P-gp) must be evaluated. This study focused on the effects of three representative Aconitum alkaloids: aconitine (AC), benzoylaconine (BAC), and aconine, on the expression and activity of P-gp. We observed that Aconitum alkaloids increased P-gp expression in LS174T and Caco-2 cells in the order AC > BAC > aconine. Nuclear receptors were involved in the induction of P-gp. AC and BAC increased the P-gp transport activity. Strikingly, intracellular ATP levels and mitochondrial mass also increased. Furthermore, exposure to AC decreased the toxicity of vincristine and doxorubicin towards the cells. In vivo, AC significantly up-regulated the P-gp protein levels in the jejunum, ileum, and colon of FVB mice, and protected them against acute AC toxicity. Taken together, the findings of our in vitro and in vivo experiments indicate that AC can induce P-gp expression, and that co-administration of AC with P-gp substrate drugs may cause DDIs. Our findings have important implications for Aconitum therapy in clinics. PMID:27139035

Expression patterns of ethylene biosynthesis genes from bananas during fruit ripening and in relationship with finger drop

PubMed Central

Hubert, Olivier; Mbéguié-A-Mbéguié, Didier

2012-01-01

Background and aims Banana finger drop is defined as dislodgement of individual fruits from the hand at the pedicel rupture area. For some banana varieties, this is a major feature of the ripening process, in addition to ethylene production and sugar metabolism. The few studies devoted to assessing the physiological and molecular basis of this process revealed (i) the similarity between this process and softening, (ii) the early onset of related molecular events, between the first and fourth day after ripening induction, and (iii) the putative involvement of ethylene as a regulatory factor. This study was conducted with the aim of identifying, through a candidate gene approach, a quality-related marker that could be used as a tool in breeding programmes. Here we examined the relationship between ripening ethylene biosynthesis (EB) and finger drop in order to gain further insight into the upstream regulatory steps of the banana finger drop process and to identify putative related candidate genes. Methods Postharvest ripening of green banana fruit was induced by acetylene treatment and fruit taken at 1–4 days after ripening induction, and total RNA extracted from the median area [control zone (CZ)] and the pedicel rupture area [drop zone (DZ)] of peel tissue. Then the expression patterns of EB genes (MaACO1, MaACO2, MaACS1, MaACS2, MaACS3 and MaACS4) were comparatively examined in CZ and DZ via real-time quantitative polymerase chain reaction. Principal results Differential expression of EB gene was observed in CZ and DZ during the postharvest period examined in this study. MaACO1, MaACS2 and MaACS1 were more highly induced in DZ than in the control, while a slight induction of the MaACS4 gene was observed. No marked differences between the two zones were observed for the MaACO2 gene. Conclusions The finger drop process enhanced EB gene expression including developmental- and ripening-induced genes (MaACO1), specific ripening-induced genes (MaACS1) and wound-induced genes (MaACS2). Thus, this process might be associated with a specific ethylene production in DZ of the pedicel area and the result of crosstalk between developmental, ripening and wound regulatory pathways. MaACO1, MaACS1, MaACS2, and to a lesser extent MaACS4 genes, which are more highly induced in DZ than in CZ, could be considered as putative candidates of the finger drop process. PMID:23267429

An analysis of nonlinear dynamics underlying neural activity related to auditory induction in the rat auditory cortex.

PubMed

Noto, M; Nishikawa, J; Tateno, T

2016-03-24

A sound interrupted by silence is perceived as discontinuous. However, when high-intensity noise is inserted during the silence, the missing sound may be perceptually restored and be heard as uninterrupted. This illusory phenomenon is called auditory induction. Recent electrophysiological studies have revealed that auditory induction is associated with the primary auditory cortex (A1). Although experimental evidence has been accumulating, the neural mechanisms underlying auditory induction in A1 neurons are poorly understood. To elucidate this, we used both experimental and computational approaches. First, using an optical imaging method, we characterized population responses across auditory cortical fields to sound and identified five subfields in rats. Next, we examined neural population activity related to auditory induction with high temporal and spatial resolution in the rat auditory cortex (AC), including the A1 and several other AC subfields. Our imaging results showed that tone-burst stimuli interrupted by a silent gap elicited early phasic responses to the first tone and similar or smaller responses to the second tone following the gap. In contrast, tone stimuli interrupted by broadband noise (BN), considered to cause auditory induction, considerably suppressed or eliminated responses to the tone following the noise. Additionally, tone-burst stimuli that were interrupted by notched noise centered at the tone frequency, which is considered to decrease the strength of auditory induction, partially restored the second responses from the suppression caused by BN. To phenomenologically mimic the neural population activity in the A1 and thus investigate the mechanisms underlying auditory induction, we constructed a computational model from the periphery through the AC, including a nonlinear dynamical system. The computational model successively reproduced some of the above-mentioned experimental results. Therefore, our results suggest that a nonlinear, self-exciting system is a key element for qualitatively reproducing A1 population activity and to understand the underlying mechanisms. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

A Novel Technique to Measure In Vivo Uterine Suspensory Ligament Stiffness

PubMed Central

Smith, Tovia M.; Luo, Jiajia; Hsu, Yvonne; Ashton-Miller, James A.; Delancey, John O.L.

2013-01-01

Objective To describe a new computer-controlled research apparatus for measuring in vivo uterine ligament force-displacement behavior and stiffness and to present pilot data in women with and without prolapse. Study Design Seventeen women with varying uterine support underwent testing in the operating room (OR) after anesthetic induction. A tripod-mounted computer-controlled linear servoactuator was used to quantify force-displacement behavior of the cervix and supporting ligaments. The servoactuator applied a caudally-directed force to a tenaculum at 4 mm/s velocity until the traction force reached 17.8N (4 lbs.). Cervix location on POP-Q in clinic, in the OR at rest, and with minimal force (<1.1N), and maximum force (17.8N) was recorded. Ligament “stiffness” between minimum and maximum force was calculated. Results The mean (SD) subject age was 54.5 (12.7) years, parity 2.9 (1.1), BMI 29.0 (4.3) kg/m2, and POP-Q point C −3.1 (3.9) cm. POP-Q point C was most strongly correlated with cervix location at maximum force (r=+0.68, p=.003) and at rest (r=+0.62, p=.009). Associations between cervix location at minimum force (r=+0.46, p=.059) and ligament stiffness (r= −0.44,p=.079) were not statistically significant. Cervix location in the OR with minimal traction lay below the lowest point found on POP-Q for 13 women. Conclusions POP-Q point C was strongly correlated with cervix location at rest and at maximum traction force; however only 19% of the variation in POP-Q point C location was explained by ligament stiffness. The cervix location in the OR at minimal traction lay below POP-Q point C value in ¾ of women. PMID:23747493

Introducing AC Inductive Reactance with a Power Tool

ERIC Educational Resources Information Center

Bryant, Wesley; Baker, Blane

2016-01-01

The concept of reactance in AC electrical circuits is often non-intuitive and difficult for students to grasp. In order to address this lack of conceptual understanding, classroom exercises compare the predicted resistance of a power tool, based on electrical specifications, to measured resistance. Once students discover that measured resistance…

DIRECT SIMULATION OF A-C MACHINERY.

DTIC Science & Technology

show the application of the simulation to both induction and synchronous machines. The fundamental space harmonic only, the fundamental and third ... space harmonic only, or all the space harmonics are considered. The report concludes that: (1) Successful direct simulation of the 2-phase induction

Electric Drive Study. Volume 1

DTIC Science & Technology

1987-12-21

CONDITIONER HIGH VOLTAGE DC ICONDITIONER 3 ,300-50 VOLT5), dCONTROL! Figure 5-4. Typical AC Drive System 20 system usable with an induction motor. The...controlling component in an AC drive is the motor power conditioner . This component changes the high voltage DC power to controlled AC power of...selected voltage and frequency which is applied to the drive motors. Since the vehicle gains stored energy as it is accelerated, the motor power conditioner

AC-Induced Bias Potential Effect on Corrosion of Steels

DTIC Science & Technology

2009-02-05

induction, variable conduction Experimental Setup Super- martensitic stainless steel composition Analysis: C Mn Si Cr Ni Mo Cu N Typical 13 Cr ɘ.01 0.6... stainless steel used in pipelines. •Low carbon (ɘ.01): allows the formation of a “soft” martensite that is more resistant than standard martensitic ...Proposed AC Corrosion Models  AC Simulated Corrosion testing  Stainless steel pipe and coating  Cathodic protection  Experimental Setup  Preliminary

Design and performance tests of a distributed power-driven wheel loader

NASA Astrophysics Data System (ADS)

Jin, Xiaolin; Shi, Laide; Bian, Yongming

2010-03-01

An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

Design and performance tests of a distributed power-driven wheel loader

NASA Astrophysics Data System (ADS)

Jin, Xiaolin; Shi, Laide; Bian, Yongming

2009-12-01

An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

Acacia catechu Ethanolic Seed Extract Triggers Apoptosis of SCC-25 Cells.

PubMed

Lakshmi, Thangavelu; Ezhilarasan, Devaraj; Nagaich, Upendra; Vijayaragavan, Rajagopal

2017-10-01

Acacia catechu Willd ( Fabaceae ), commonly known as catechu, cachou, and black cutch, has been studied for its hepatoprotective, antipyretic, antidiarrheal, hypoglycemic, anti-inflammatory, immunomodulatory, antinociceptive, antimicrobial, free radical scavenging, and antioxidant activities. We evaluated the cytotoxic activity of ethanol extract of A. catechu seed (ACS) against SCC-25 human oral squamous carcinoma cell line. Cytotoxic effect of ACS extract was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, using concentrations of 0.1-1000 μg/mL for 24 h. A. catechu ethanol seed extract was treated SCC-25 cells with 25 and 50 μg/mL. At the end of treatment period, apoptotic marker gene expressions such as caspase 8, 9, Bcl-2, Bax, and cytochrome c were evaluated by semiquantitative reverse transcription-polymerase chain reaction. Morphological changes of ACS treated SCC-25 cells was evaluated by acridine orange/ethidium bromide (AO/EB) dual staining. Nuclear morphology and DNA fragmentation was evaluated by propidium iodide (PI) staining. A. catechu ethanol seed extract treatment caused cytotoxicity in SCC-25 cells with an IC 50 value of 100 μg/mL. Apoptotic markers caspases 8 and 9, cytochrome c, Bax gene expressions were significantly increased upon ACS extract treatment indicate the apoptosis induction in SCC-25 cells. This treatment also caused significant downregulation of Bcl-2 gene expression. Staining with AO/EB and PI shows membrane blebbing, and nuclear membrane distortion further confirms the apoptosis induction by ACS treatment in SCC-25 cells. The ethanol seed extracts of A. catechu was found to be cytotoxic at lower concentrations and induced apoptosis in human oral squamous carcinoma SCC-25 cells. Acacia catechu ethanolic seed extract contains phytochemicals such as epicatechin, rutin, and quercetin Acacia catechu seed (ACS) extract significantly ( P < 0.001) inhibits the active proliferation of human oral squamous carcinoma (SCC-25) cellsACS extract treatment to SCC-25 cells significantly modulated the gene expressions pertaining to apoptosis and propidium iodide and acridine orange/ethidium bromide staining also confirm the apoptosis inductionAntiproliferative and apoptosis inducing activities of ACS extract is correlated with phytochemical contents. Abbreviations used: ACS: Acacia catechu seed extract; MTT: 3 (4,5 dimethylthiazol 2 yl) 2,5 diphenyltetrazolium bromide; DMSO: Dimethyl sulfoxide; AO/EO: Acridine orange/ethidium bromide; LC MS: Liquid chromatography mass spectrometry.

Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

NASA Technical Reports Server (NTRS)

Latos, T. S.

1982-01-01

An improved ac motor controller, which when coupled to a standard ac induction motor and a dc propulsion battery would provide a complete electric vehicle power train with the exception of the mechanical transmission and drive wheels was designed. In such a system, the motor controller converts the dc electrical power available at the battery terminals to ac electrical power for the induction motor in response to the drivers commands. The performance requirements of a hypothetical electric vehicle with an upper weight bound of 1590 kg (3500 lb) were used to determine the power rating of the controller. Vehicle acceleration capability, top speed, and gradeability requisites were contained in the Society of Automotive Engineers (SAE) Schedule 227a(d) driving cycle. The important capabilities contained in this driving cycle are a vehicle acceleration requirement of 0 to 72.4 kmph (0 to 45 mph) in 28 seconds a top speed of 88.5 kmph (55 mph), and the ability to negotiate a 10% grade at 48 kmph (30 mph). A 10% grade is defined as one foot of vertical rise per 10 feet of horizontal distance.

Fuzzy efficiency optimization of AC induction motors

NASA Technical Reports Server (NTRS)

Jani, Yashvant; Sousa, Gilberto; Turner, Wayne; Spiegel, Ron; Chappell, Jeff

1993-01-01

This paper describes the early states of work to implement a fuzzy logic controller to optimize the efficiency of AC induction motor/adjustable speed drive (ASD) systems running at less than optimal speed and torque conditions. In this paper, the process by which the membership functions of the controller were tuned is discussed and a controller which operates on frequency as well as voltage is proposed. The membership functions for this dual-variable controller are sketched. Additional topics include an approach for fuzzy logic to motor current control which can be used with vector-controlled drives. Incorporation of a fuzzy controller as an application-specific integrated circuit (ASIC) microchip is planned.

Variable frequency inverter for ac induction motors with torque, speed and braking control

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1975-01-01

A variable frequency inverter was designed for driving an ac induction motor which varies the frequency and voltage to the motor windings in response to varying torque requirements for the motor so that the applied voltage amplitude and frequency are of optimal value for any motor load and speed requirement. The slip frequency of the motor is caused to vary proportionally to the torque and feedback is provided so that the most efficient operating voltage is applied to the motor. Winding current surge is limited and a controlled negative slip causes motor braking and return of load energy to a dc power source.

P143 proteins from heterologous nucleopolyhedroviruses induce apoptosis in BM-N cells derived from the silkworm Bombyx mori.

PubMed

Hamajima, Rina; Kobayashi, Michihiro; Ikeda, Motoko

2017-04-02

We previously demonstrated that ribosomal RNA (rRNA) of Bombyx mori BM-N cells is rapidly degraded upon infection with heterologous nucleopolyhedroviruses (NPVs), including Autographa californica multiple NPV (AcMNPV), Hyphantria cunea MNPV, Spodoptera exigua MNPV and S. litura MNPV, and that this response is triggered by viral P143 proteins. The transient expression of P143 proteins from heterologous NPVs was also shown to induce apoptosis and caspase-3-like protease activation in BM-N cells. In the present study, we conducted a transient expression assay using BM-N cells expressing mutant AcMNPV P143 (Ac-P143) proteins and demonstrated that five amino acid residues cooperatively participate in Ac-P143 protein-triggered apoptosis of BM-N cells. Notably, these five residues were previously shown to be required for triggering rRNA degradation in BM-N cells. As rRNA degradation in BM-N cells does not result from apoptosis, the present results suggest that Ac-P143-triggered rRNA degradation is the upstream signal for apoptosis induction in BM-N cells. We further showed that P143 protein-triggered apoptosis does not occur in S. frugiperda Sf9 or Lymantria dispar Ld652Y cells, indicating that apoptosis induction by heterologous P143 proteins is a BM-N cell-specific response. In addition, the observed induction of apoptosis in BM-N cells was found to be mediated by activation of the initiator caspase Bm-Dronc. Taken together, these results suggest that BM-N cells evolved a unique antiviral system that recognizes heterologous NPV P143 proteins to induce rRNA degradation and caspase-dependent apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

High-Frequency ac Power-Distribution System

NASA Technical Reports Server (NTRS)

Hansen, Irving G.; Mildice, James

1987-01-01

Loads managed automatically under cycle-by-cycle control. 440-V rms, 20-kHz ac power system developed. System flexible, versatile, and "transparent" to user equipment, while maintaining high efficiency and low weight. Electrical source, from dc to 2,200-Hz ac converted to 440-V rms, 20-kHz, single-phase ac. Power distributed through low-inductance cables. Output power either dc or variable ac. Energy transferred per cycle reduced by factor of 50. Number of parts reduced by factor of about 5 and power loss reduced by two-thirds. Factors result in increased reliability and reduced costs. Used in any power-distribution system requiring high efficiency, high reliability, low weight, and flexibility to handle variety of sources and loads.

Rolling, slip and traction measurements on low modulus materials

NASA Technical Reports Server (NTRS)

Tevaarwerk, J. L.

1985-01-01

Traction and wear tests were performed on six low modulus materials (LMM). Three different traction tests were performed to determine the suitability of the material for use as traction rollers. These were the rolling, slip and endurance traction tests. For each material the combination LMM on LMM and LMM on steel were evaluated. Rolling traction test were conducted to determine the load - velocity limits, the rolling traction coefficient of the materials and to establish the type of failures that would result when loading beyond the limit. It was found that in general a simple constant rolling traction coefficient was enough to describe the results of all the test. The slip traction tests revealed that the peak traction coefficients were considerably higher than for lubricated traction contacts. The endurance traction tests were performed to establish the durability of the LMM under conditions of prolonged traction. Wear measurements were performed during and after the test. Energetic wear rates were determined from the wear measurements conducted in the endurance traction tests. These values show that the roller wear is not severe when reasonable levels of traction are transmitted.

Motor torque compensation of an induction electric motor by adjusting a slip command during periods of supposed change in motor temperature

DOEpatents

Kelledes, William L.; St. John, Don K.

1992-01-01

The present invention maintains constant torque in an inverter driven AC induction motor during variations in rotor temperature. It is known that the torque output of a given AC induction motor is dependent upon rotor temperature. At rotor temperatures higher than the nominal operating condition the rotor impedance increases, reducing the rotor current and motor torque. In a similar fashion, the rotor impedance is reduced resulting in increased rotor current and motor torque when the rotor temperature is lower than the nominal operating condition. The present invention monitors the bus current from the DC supply to the inverter and adjusts the slip frequency of the inverter drive to maintain a constant motor torque. This adjustment is based upon whether predetermined conditions implying increased rotor temperature or decreased rotor temperature exist for longer that a predetermined interval of time.

Dynamic Average-Value Modeling of Doubly-Fed Induction Generator Wind Energy Conversion Systems

NASA Astrophysics Data System (ADS)

Shahab, Azin

In a Doubly-fed Induction Generator (DFIG) wind energy conversion system, the rotor of a wound rotor induction generator is connected to the grid via a partial scale ac/ac power electronic converter which controls the rotor frequency and speed. In this research, detailed models of the DFIG wind energy conversion system with Sinusoidal Pulse-Width Modulation (SPWM) scheme and Optimal Pulse-Width Modulation (OPWM) scheme for the power electronic converter are developed in detail in PSCAD/EMTDC. As the computer simulation using the detailed models tends to be computationally extensive, time consuming and even sometimes not practical in terms of speed, two modified approaches (switching-function modeling and average-value modeling) are proposed to reduce the simulation execution time. The results demonstrate that the two proposed approaches reduce the simulation execution time while the simulation results remain close to those obtained using the detailed model simulation.

Module Two: Voltage; Basic Electricity and Electronics Individualized Learning System.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

In this module the student will study and learn what voltage is, how it is generated, what AC (alternating current) and DC (direct current) are and why both kinds are needed, and how to measure voltages. The module is divided into six lessons: EMF (electromotive force) from chemical action, magnetism, electromagnetic induction, AC voltage, the…

Novel characteristics of traction force in biliary self-expandable metallic stents.

PubMed

Hori, Yasuki; Hayashi, Kazuki; Yoshida, Michihiro; Naitoh, Itaru; Ban, Tesshin; Miyabe, Katsuyuki; Kondo, Hiromu; Nishi, Yuji; Umemura, Shuichiro; Fujita, Yasuaki; Natsume, Makoto; Kato, Akihisa; Ohara, Hirotaka; Joh, Takashi

2017-05-01

In recent years, knowledge concerning the mechanical properties of self-expandable metallic stents (SEMS) has increased. In a previous study, we defined traction force and traction momentum and reported that these characteristics are important for optimal stent deployment. However, traction force and traction momentum were represented as relative values and were not evaluated in various conditions. The purpose of the present study was to measure traction force in various situations assumed during SEMS placement. Traction force and traction momentum were measured in non-stricture, stricture, and angled stricture models using in-house equipment. Stricture and angled stricture models had significantly higher traction force and traction momentum than those of the non-stricture model (stricture vs non-stricture: traction force, 7.2 N vs 1.4 N, P < 0.001; traction momentum, 237.8 Ns vs 62.3 Ns, P = 0.001; angled stricture vs non-stricture: traction force, 7.4 N vs 1.4 N, P < 0.001; traction momentum, 307.2 Ns vs 62.3 Ns, P < 0.001). Traction force was variable during SEMS placement and was categorized into five different stages, which were similar in both the stricture and angled stricture models. We measured traction force and traction momentum under simulated clinical conditions and demonstrated that strictures and the angular positioning of the stent influenced the traction force. Clinicians should be aware of the transition of the traction force and should schedule X-ray imaging during SEMS placement. © 2017 Japan Gastroenterological Endoscopy Society.

Compensation for Harmonic Currents and Reactive Power in Wind Power Generation System using PWM Inverter

NASA Astrophysics Data System (ADS)

Shinohara, Katsuji; Shinhatsubo, Kurato; Iimori, Kenichi; Yamamoto, Kichiro; Saruban, Takamichi; Yamaemori, Takahiro

In recent year, consciousness of environmental problems is enhancing, and the price of the electric power purchased by an electric power company is established expensive for the power plant utilizing the natural energy. So, the introduction of the wind power generation is promoted in Japan. Generally, squirrel-cage induction machines are widely used as a generator in wind power generation system because of its small size, lightweight and low-cost. However, the induction machines do not have a source of excitation. Thus, it causes the inrush currents and the instantaneous voltage drop when the generator is directly connected to a power grid. To reduce the inrush currents, an AC power regulator is used. Wind power generations are frequently connected to and disconnected from the power grid. However, when the inrush currents are reduced, harmonic currents are caused by phase control of the AC power regulator. And the phase control of AC power regulator cannot control the power factor. Therefore, we propose the use of the AC power regulator to compensate for the harmonic currents and reactive power in the wind power generation system, and demonstrate the validity of its system by simulated and experimental results.

Offline detection of broken rotor bars in AC induction motors

NASA Astrophysics Data System (ADS)

Powers, Craig Stephen

ABSTRACT. OFFLINE DETECTION OF BROKEN ROTOR BARS IN AC INDUCTION MOTORS. The detection of the broken rotor bar defect in medium- and large-sized AC induction machines is currently one of the most difficult tasks for the motor condition and monitoring industry. If a broken rotor bar defect goes undetected, it can cause a catastrophic failure of an expensive machine. If a broken rotor bar defect is falsely determined, it wastes time and money to physically tear down and inspect the machine only to find an incorrect diagnosis. Previous work in 2009 at Baker/SKF-USA in collaboration with the Korea University has developed a prototype instrument that has been highly successful in correctly detecting the broken rotor bar defect in ACIMs where other methods have failed. Dr. Sang Bin and his students at the Korea University have been using this prototype instrument to help the industry save money in the successful detection of the BRB defect. A review of the current state of motor conditioning and monitoring technology for detecting the broken rotor bar defect in ACIMs shows improved detection of this fault is still relevant. An analysis of previous work in the creation of this prototype instrument leads into the refactoring of the software and hardware into something more deployable, cost effective and commercially viable.

Development and characterisation of polymeric microparticle of poly(d,l-lactic acid) loaded with holmium acetylacetonate.

PubMed

de Azevedo, Mariangela de Burgos M; de Melo, Vitor H S; Soares, Carlos Roberto J; Miyamoto, Douglas M; Katayama, Ricardo A; Squair, Peterson L; Barros, Caio H N; Tasic, Ljubica

2018-06-14

Biodegradable polymers containing radioactive isotopes such as Holmium 166 ( 166 Ho) have potential applications as beta particle emitters in tumour tissues. It is also a gamma ray emitter, allowing nuclear imaging of any tissue to be acquired. It is frequently used in the form of complexes such as holmium acetylacetonate (HoAcAc), which may cause damages in tissues next to the targets cancer cells, as it is difficult to control its linkage or healthy tissues radiotherapy effects. Poly(d,l-lactic acid), PDLLA, was used to encapsulate holmium acetylacetonate (HoAcAc) using an emulsion solvent extraction/evaporation technique. Microspheres with sizes between 20-53 µm were extensively characterised. HoAcAc release from the microspheres was assessed through studies using Inductively Coupled Plasma - Optical Emission Spectroscopy, and the microspheres showed no holmium leakage after a period of 10 half-lives and following gamma irradiation. Thus, HoAcAc loaded microspheres are here presented as a potential system for brachytherapy and imaging purposes.

Footwear traction and lower extremity noncontact injury.

PubMed

Wannop, John W; Luo, Geng; Stefanyshyn, Darren J

2013-11-01

Football is the most popular high school sport; however, it has the highest rate of injury. Speculation has been prevalent that foot fixation due to high footwear traction contributes to injury risk. Therefore, the purpose of the study was to determine whether a relationship exists between the athlete's specific footwear traction (measured with their own shoes on the field of play) and lower extremity noncontact injury in high school football. For 3 yr, 555 high school football athletes had their footwear traction measured on the actual field of play at the start of the season, and any injury the athletes suffered during a game was recorded. Lower extremity noncontact injury rates, grouped based on the athlete's specific footwear traction (both translational and rotational), were compared. For translational traction, injury rate reached a peak of 23.3 injuries/1000 game exposures within the midrange of translational traction, before decreasing to 5.0 injuries/1000 game exposures in the high range of traction. For rotational traction, there was a steady increase in injury rate as footwear traction increased, starting at 4.2 injuries/1000 game exposures at low traction and reaching 19.2 injuries/1000 game exposures at high traction. A relationship exists between footwear traction and noncontact lower extremity injury, with increases in rotational traction leading to a greater injury rate and increases in translational traction leading to a decrease in injury. It is recommended that athletes consider selecting footwear with the lowest rotational traction values for which no detriment in performance results.

Baseline Chromatin Modification Levels May Predict ...

EPA Pesticide Factsheets

Traditional toxicological paradigms have relied on factors such as age, genotype, and disease status to explain variability in responsiveness to toxicant exposure; however, these are neither sufficient to faithfully identify differentially responsive individuals nor are they modifiable factors that can be leveraged to mitigate the exposure effects. Unlike these factors, the epigenome is dynamic and shaped by an individual's environment. We sought to determine whether baseline levels of specific chromatin modifications correlated with the interindividual variability in their ozone (03)-mediated induction in an air-liquid interface model using primary human bronchial epithelial cells from a panel of 11 donors. We characterized the relationship between the baseline abundance of 6 epigenetic markers with established roles as key regulators of gene expression-histone H3 lysine 4 trimethylation (H3K4me3), H3K27 acetylation (H3K27ac), pan­acetyl H4 (H4ac), histone H3K27 di/trimethylation (H3K27me2/3), unmodified H3, and5-hydroxymethylcytosine (5-hmC)-and the variability in the 03-induced expression of IL-8, IL-6, COX2, and HMOX1. Baseline levels of H3K4me3, H3K27me2/3, and 5-hmC, but not H3K27ac, H4ac, and total H3, correlated with the interindividual variability in 03-mediated induction of HMOX1 and COX2. In contrast, none of the chromatin modifications that we examined correlated with the induction of IL-8 and IL-6. From these findings, we propose an "epigenetic see

Regression analysis of traction characteristics of traction fluids

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Rohn, D. A.

1983-01-01

Traction data for Santotrac 50 and TDF-88 over a wide range of operating conditions were analyzed. An eight term correlation equation to predict the maximum traction coefficient and a six term correlation equation to predict the initial slope of the traction curve were developed. The slope correlation was corrected for size effect considering the compliance of the disks. The effects of different operating conditions on the traction performance of each traction fluid were studied. Both fluids exhibited a loss in traction with increases in spin, but the losses with the TDF-88 fluid were not as severe as those with Santotrac 50. Overall, both fluids exhibited similar performance, showing an increase in traction with contact pressure up to about 2.0 GPa, and a reduction in traction with higher surface speeds up to about 100 m/sec. The apparent stiffness of the traction contact, that is, film disk combination, increases with contact pressure and decreases with speed.

Activity against Mycobacterium tuberculosis with concomitant induction of cellular immune responses by a tetraaza-macrocycle with acetate pendant arms.

PubMed

David, S; Ordway, D; Arroz, M J; Costa, J; Delgado, R

2001-01-01

The novel tetraaza-macrocyclic compound 3,7,11-tris(carboxymethyl)-3,7,11,17-tetraaza-bicyclo[11.3.1]heptadeca-1(17),13,15-triene, abbreviated as ac3py14, was investigated for its activity against Mycobacterium tuberculosis and for induction of protective cellular immune responses. Perspective results show that ac3py14 and its Fe3+ 1:1 complex, [Fe(ac3py14)], inhibited radiometric growth of several strains of M. tuberculosis. Inhibition with 25 microg/mL varied from 99% for H37Rv to 80% and above for multiple drug-resistant clinical isolates. The capacity of ac3py14 to elicit a beneficial immune response without cellular apoptosis was assessed and compared to the effects of virulent M. tuberculosis. The present study produces evidence that after stimulation with ac3py14 there was significant production of interferon gamma (IFN-gamma), whereas the production of interleukin-5 (IL-5) remained low, and there was development of a memory population (CD45RO). The level of binding of Annexin V, a marker of apoptosis, was not sufficient to result in toxic effects toward alphabeta and gammadelta T cells and CD14+ macrophages. This preliminary study is the first report of a compound that simultaneously exerts an inhibitory effect against M. tuberculosis and induces factors associated with protective immune responses.

Electromechanical systems with transient high power response operating from a resonant AC link

NASA Technical Reports Server (NTRS)

Burrows, Linda M.; Hansen, Irving G.

1992-01-01

The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant AC link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the AC link allows the converter in these systems to switch at the zero crossing of every half cycle of the AC waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed by LeRC and General Dynamics Space Systems Division under contract to NASA. A description of a single motor, electromechanical actuation system is presented. Then, focus is on a conceptual design for an AC electric vehicle. This design incorporates an induction motor/generator together with a flywheel for peak energy storage. System operation and implications along with the associated circuitry are addressed. Such a system would greatly improve all-electric vehicle ranges over the Federal Urban Driving Cycle (FUD).

An organ-specific role for ethylene in rose petal expansion during dehydration and rehydration

PubMed Central

Liu, Daofeng; Liu, Xiaojing; Meng, Yonglu; Sun, Cuihui; Tang, Hongshu; Jiang, Yudong; Khan, Muhammad Ali; Xue, Jingqi; Ma, Nan; Gao, Junping

2013-01-01

Dehydration is a major factor resulting in huge loss from cut flowers during transportation. In the present study, dehydration inhibited petal cell expansion and resulted in irregular flowers in cut roses, mimicking ethylene-treated flowers. Among the five floral organs, dehydration substantially elevated ethylene production in the sepals, whilst rehydration caused rapid and elevated ethylene levels in the gynoecia and sepals. Among the five ethylene biosynthetic enzyme genes (RhACS1–5), expression of RhACS1 and RhACS2 was induced by dehydration and rehydration in the two floral organs. Silencing both RhACS1 and RhACS2 significantly suppressed dehydration- and rehydration-induced ethylene in the sepals and gynoecia. This weakened the inhibitory effect of dehydration on petal cell expansion. β-glucuronidase activity driven by both the RhACS1 and RhACS2 promoters was dramatically induced in the sepals, pistil, and stamens, but not in the petals of transgenic Arabidopsis. This further supports the organ-specific induction of these two genes. Among the five rose ethylene receptor genes (RhETR1–5), expression of RhETR3 was predominantly induced by dehydration and rehydration in the petals. RhETR3 silencing clearly aggravated the inhibitory effect of dehydration on petal cell expansion. However, no significant difference in the effect between RhETR3-silenced flowers and RhETR-genes-silenced flowers was observed. Furthermore, RhETR-genes silencing extensively altered the expression of 21 cell expansion-related downstream genes in response to ethylene. These results suggest that induction of ethylene biosynthesis by dehydration proceeds in an organ-specific manner, indicating that ethylene can function as a mediator in dehydration-caused inhibition of cell expansion in rose petals. PMID:23599274

Effects of pole flux distribution in a homopolar linear synchronous machine

NASA Astrophysics Data System (ADS)

Balchin, M. J.; Eastham, J. F.; Coles, P. C.

1994-05-01

Linear forms of synchronous electrical machine are at present being considered as the propulsion means in high-speed, magnetically levitated (Maglev) ground transportation systems. A homopolar form of machine is considered in which the primary member, which carries both ac and dc windings, is supported on the vehicle. Test results and theoretical predictions are presented for a design of machine intended for driving a 100 passenger vehicle at a top speed of 400 km/h. The layout of the dc magnetic circuit is examined to locate the best position for the dc winding from the point of view of minimum core weight. Measurements of flux build-up under the machine at different operating speeds are given for two types of secondary pole: solid and laminated. The solid pole results, which are confirmed theoretically, show that this form of construction is impractical for high-speed drives. Measured motoring characteristics are presented for a short length of machine which simulates conditions at the leading and trailing ends of the full-sized machine. Combination of the results with those from a cylindrical version of the machine make it possible to infer the performance of the full-sized traction machine. This gives 0.8 pf and 0.9 efficiency at 300 km/h, which is much better than the reported performance of a comparable linear induction motor (0.52 pf and 0.82 efficiency). It is therefore concluded that in any projected high-speed Maglev systems, a linear synchronous machine should be the first choice as the propulsion means.

System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

NASA Technical Reports Server (NTRS)

Lipo, Thomas A.; Alan, Irfan

1991-01-01

Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the addition of extra energy storage elements to the HF link are described. The importance of the source voltage level to achieve a better current regulation for the source side PDMC is also briefly discussed. The power levels achieved in the motoring mode of operation show that the proposed power levels achieved in the generating mode of operation can also be easily achieved provided that no mechanical speed limitation were present to drive the induction machine at the proposed power level.

Power And Propulsion Systems For Mobile Robotic Applications

NASA Astrophysics Data System (ADS)

Layuan, Li; Haiming, Zou

1987-02-01

Choosing the best power and propulsion systems for mobile robotic land vehicle applications requires consideration of technologies. The electric power requirements for onboard electronic and auxiliary equipment include 110/220 volt 60 Hz ac power as well as low voltage dc power. Weight and power are saved by either direct dc power distribution, or high frequency (20 kHz) ac power distribution. Vehicle control functions are performed electronically but steering, braking and traction power may be distributed electrically, mechanically or by fluid (hydraulic) means. Electric drive is practical, even for small vehicles, provided that advanced electric motors are used. Such electric motors have demonstrated power densities of 3.1 kilowatts per kilogram with devices in the 15 kilowatt range. Electric motors have a lower torque, but higher power density as compared to hydraulic or mechanical transmission systems. Power density being comparable, electric drives were selected to best meet the other requirements for robotic vehicles. Two robotic vehicle propulsion system designs are described to illustrate the implementation of electric drive over a vehicle size range of 250-7500 kilograms.

A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

DOE PAGES

Gerber, Daniel L.; Vossos, Vagelis; Feng, Wei; ...

2017-06-12

Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of paramet ric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simplermore » approaches and arithmetic efficiency models. This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.« less

A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

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

Gerber, Daniel L.; Vossos, Vagelis; Feng, Wei

Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of paramet ric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simplermore » approaches and arithmetic efficiency models. This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.« less

Management of critically ill surgical patients Case reports.

PubMed

Mangiante, Gerardo; Padoan, Roberto; Mengardo, Valentina; Bencivenga, Maria; de Manzoni, Giovanni

2016-01-01

The acute abdomen (AA) still remains a challenging situation for surgeons. New pathological conditions have been imposed to our attention in this field in recent years. The definition of abdominal compartmental syndrome (ACS) in surgical practice and the introduction of new biological matrices, with the concepts of tension-free (TS) repair of incisional hernias, prompted us to set up new therapeutic strategies for the treatment of patients with AA. Thus we reviewed the cases of AA that we observed in recent years in which we performed a laparostomy in order to prevent or to treat an ACS. They are all cases of acute abdomen (AA), but from different origin, including chronic diseases, as in the course of inflammatory bowel disease (IBD), and acute pancreatitis. In all the cases, the open abdominal cavity was covered with a polyethylene sheet. The edges of the wound were sutured to the plastic sheet, and a traction exerted by a device that causes a negative pressure was added. This method was adopted in several cases without randomization, and resulted in excellent patient's outcomes. Abdominal compartmental syndrome, Acute abdomen, Laparostomy.

Assay Methods for ACS Activity and ACS Phosphorylation by MAP Kinases In Vitro and In Vivo.

PubMed

Han, Xiaomin; Li, Guojing; Zhang, Shuqun

2017-01-01

Ethylene, a gaseous phytohormone, has profound effects on plant growth, development, and adaptation to the environment. Ethylene-regulated processes begin with the induction of ethylene biosynthesis. There are two key steps in ethylene biosynthesis. The first is the biosynthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) from S-Adenosyl-Methionine (SAM), a common precursor in many metabolic pathways, which is catalyzed by ACC synthase (ACS). The second is the oxidative cleavage of ACC to form ethylene under the action of ACC oxidase (ACO). ACC biosynthesis is the committing and generally the rate-limiting step in ethylene biosynthesis. As a result, characterizing the cellular ACS activity and understanding its regulation are important. In this chapter, we detail the methods used to measure, (1) the enzymatic activity of both recombinant and native ACS proteins, and (2) the phosphorylation of ACS protein by mitogen-activated protein kinases (MAPKs) in vivo and in vitro.

Simulation on the Effects of Surfactants and Observed Thermocapillary Motion for Laser Melting Physics

NASA Astrophysics Data System (ADS)

Nourgaliev, Robert; Barney, Rebecca; Weston, Brian; Delplanque, Jean-Pierre; McCallen, Rose

2017-11-01

A newly developed, robust, high-order in space and time, Newton-Krylov based reconstructed discontinuous Galerkin (rDG) method is used to model and analyze thermocapillary convection in melt pools. The application of interest is selective laser melting (SLM) which is an Additive Manufacturing (AM, 3D metal laser printing) process. These surface tension driven flows are influenced by temperature gradients and surfactants (impurities), and are known as the Marangoni flow. They have been experimentally observed in melt pools for welding applications, and are thought to influence the microstructure of the re-solidified material. We study the effects of the laser source configuration (power, beam size and scanning speed), as well as surfactant concentrations. Results indicate that the surfactant concentration influences the critical temperature, which governs the direction of the surface thermocapillary traction. When the surface tension traction changes sign, very complex flow patterns emerge, inducing hydrodynamic instability under certain conditions. These in turn would affect the melt pool size (depth) and shape, influencing the resulting microstructure, properties, and performance of a finished product part produced using 3D metal laser printing technologies. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Information management release number LLNL-ABS-735908.

Traction behavior of two traction lubricants

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Rohn, D. A.

1983-01-01

In the analysis of rolling-sliding concentrated contacts, such as gears, bearings and traction drives, the traction characteristics of the lubricant are of prime importance. The elastic shear modulus and limiting shear stress properties of the lubricant dictate the traction/slip characteristics and power loss associated with an EHD contact undergoing slip and/or spin. These properties can be deducted directly from the initial slope m and maximum traction coefficient micron of an experimental traction curve. In this investigation, correlation equations are presented to predict m and micron for two modern traction fluids based on the regression analysis of 334 separate traction disk machine experiments. The effects of contact pressure, temperature, surface velocity, ellipticity ratio are examined. Problems in deducing lubricant shear moduli from disk machine tests are discussed.

Anomalous satellite inductive peaks in alternating current response of defective carbon nanotubes

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

Hirai, Daisuke; Watanabe, Satoshi; Yamamoto, Takahiro

2014-05-07

AC response of defective metallic carbon nanotubes is investigated from first principles. We found that capacitive peaks appear at electron scattering states. Moreover, we show that satellite inductive peaks are seen adjacent to a main capacitive peak, which is in contrast to the conductance spectra having no satellite features. The appearance of satellite inductive peaks seems to depend on the scattering states. Our analysis with a simple resonant scattering model reveals that the origin of the satellite inductive peaks can be understood by just one parameter, i.e., the lifetime of electrons at a defect state.

Induction voidmeter

DOEpatents

Anderson, Thomas T.; Roop, Conard J.; Schmidt, Kenneth J.; Brewer, John

1986-01-01

An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

The "soluble" adenylyl cyclase in sperm mediates multiple signaling events required for fertilization.

PubMed

Hess, Kenneth C; Jones, Brian H; Marquez, Becky; Chen, Yanqiu; Ord, Teri S; Kamenetsky, Margarita; Miyamoto, Catarina; Zippin, Jonathan H; Kopf, Gregory S; Suarez, Susan S; Levin, Lonny R; Williams, Carmen J; Buck, Jochen; Moss, Stuart B

2005-08-01

Mammalian fertilization is dependent upon a series of bicarbonate-induced, cAMP-dependent processes sperm undergo as they "capacitate," i.e., acquire the ability to fertilize eggs. Male mice lacking the bicarbonate- and calcium-responsive soluble adenylyl cyclase (sAC), the predominant source of cAMP in male germ cells, are infertile, as the sperm are immotile. Membrane-permeable cAMP analogs are reported to rescue the motility defect, but we now show that these "rescued" null sperm were not hyperactive, displayed flagellar angulation, and remained unable to fertilize eggs in vitro. These deficits uncover a requirement for sAC during spermatogenesis and/or epididymal maturation and reveal limitations inherent in studying sAC function using knockout mice. To circumvent this restriction, we identified a specific sAC inhibitor that allowed temporal control over sAC activity. This inhibitor revealed that capacitation is defined by separable events: induction of protein tyrosine phosphorylation and motility are sAC dependent while acrosomal exocytosis is not dependent on sAC.

Comparison of the intervertebral disc spaces between axial and anterior lean cervical traction.

PubMed

Chung, Chin-Teng; Tsai, Sen-Wei; Chen, Chun-Jung; Wu, Ting-Chung; Wang, David; Lan, Haw-Chang H; Wu, Shyi-Kuen

2009-11-01

The insufficient investigations on the changes of spinal structures during traction prevent further exploring the possible therapeutic mechanism of cervical traction. A blind randomized crossover-design study was conducted to quantitatively compare the intervertebral disc spaces between axial and anterior lean cervical traction in sitting position. A total of 96 radiographic images from the baseline measurements, axial and anterior lean tractions in 32 asymptomatic subjects were digitized for further analysis. The intra- and inter-examiner reliabilities for measuring the intervertebral disc spaces were in good ranges (ICCs = 0.928-0.942). With the application of anterior lean traction, the statistical increases were detected both in anterior and in posterior disc spaces compared to the baseline (0.29 mm and 0.24 mm; both P < 0.01) and axial traction (0.16 mm and 0.35 mm; both P < 0.01). The greater intervertebral disc spaces obtained during anterior lean traction might be associated with the more even distribution of traction forces over the anterior and posterior neck structures. The neck extension moment through mandible that generally occurred in the axial traction could be counteracted by the downward force of head weight during anterior lean traction. This study quantitatively demonstrated that anterior lean traction in sitting position provided more intervertebral disc space enlargements in both anterior and posterior aspects than axial traction did. These findings may serve as a therapeutic reference when cervical traction is suggested.

Elastic model of the traction behavior of two traction lubricants

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Rohn, D. A.

1984-01-01

In the analysis of rolling-sliding concentrated contacts, such as gears, bearings and traction drives, the traction characteristics of the lubricant are of prime importance. The elastic shear modulus and limiting shear stress properties of the lubricant dictate the traction/slip characteristics and power loss associated with an EHD contact undergoing slip and/or spin. These properties can be deducted directly from the initial slope m and maximum traction coefficient micron of an experimental traction curve. In this investigation, correlation equations are presented to predict m and micron for two modern traction fluids based on the regression analysis of 334 separate traction disk machine experiments. The effects of contact pressure, temperature, surface velocity, ellipticity ratio are examined. Problems in deducing lubricant shear moduli from disk machine tests are discussed. Previously announced in STAR as N83-20116

Investigation of self-excited induction generators for wind turbine applications

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

Muljadi, E.; Butterfield, C.P.; Sallan, J.

2000-02-28

The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency. With a constant frequency operation, the induction generator operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency only within a small range of wind speed variation. The variable-speed operation allows an increase in energy captured and reduces both the torque peaks in the drive train and the power fluctuations sentmore » to the utility. In variable-speed operation, an induction generator needs an interface to convert the variable frequency output of the generator to the fixed frequency at the utility. This interface can be simplified by using a self-excited generator because a simple diode bridge is required to perform the ac/dc conversion. The subsequent dc/ac conversion can be performed using different techniques. The use of a thyristor bridge is readily available for large power conversion and has a lower cost and higher reliability. The firing angle of the inverter bridge can be controlled to track the optimum power curve of the wind turbine. With only diodes and thyristors used in power conversion, the system can be scaled up to a very high voltage and high power applications. This paper analyzes the operation of such a system applied to a 1/3-hp self-excited induction generator. It includes the simulations and tests performed for the different excitation configurations.« less

Systemic Induction of the Defensin and Phytoalexin Pisatin Pathways in Pea (Pisum sativum) against Aphanomyces euteiches by Acetylated and Nonacetylated Oligogalacturonides.

PubMed

Selim, Sameh; Sanssené, Jean; Rossard, Stéphanie; Courtois, Josiane

2017-06-19

Oligogalacturonides (OGs) are known for their powerful ability to stimulate the plant immune system but little is known about their mode of action in pea ( Pisum sativum ). In the present study, we investigated the elicitor activity of two fractions of OGs, with polymerization degrees (DPs) of 2-25, in pea against Aphanomyces euteiches . One fraction was nonacetylated (OGs - Ac) whereas the second one was 30% acetylated (OGs + Ac). OGs were applied by injecting the upper two rachises of the plants at three- and/or four-weeks-old. Five-week-old roots were inoculated with 10⁵ zoospores of A. euteiches . The root infection level was determined at 7, 10 and 14 days after inoculation using the quantitative real-time polymerase chain reaction (qPCR). Results showed significant root infection reductions namely 58, 45 and 48% in the plants treated with 80 µg OGs + Ac and 59, 56 and 65% with 200 µg of OGs - Ac. Gene expression results showed the upregulation of genes involved in the antifungal defensins, lignans and the phytoalexin pisatin pathways and a priming effect in the basal defense, SA and ROS gene markers as a response to OGs. The reduction of the efficient dose in OGs + Ac is suggesting that acetylation is necessary for some specific responses. Our work provides the first evidence for the potential of OGs in the defense induction in pea against Aphanomyces root rot.

Single Phase Passive Rectification Versus Active Rectification Applied to High Power Stirling Engines

NASA Technical Reports Server (NTRS)

Santiago, Walter; Birchenough, Arthur G.

2006-01-01

Stirling engine converters are being considered as potential candidates for high power energy conversion systems required by future NASA explorations missions. These types of engines typically contain two major moving parts, the displacer and the piston, in which a linear alternator is attached to the piston to produce a single phase sinusoidal waveform at a specific electric frequency. Since all Stirling engines perform at low electrical frequencies (less or equal to 100 Hz), space explorations missions that will employ these engines will be required to use DC power management and distribution (PMAD) system instead of an AC PMAD system to save on space and weight. Therefore, to supply such DC power an AC to DC converter is connected to the Stirling engine. There are two types of AC to DC converters that can be employed, a passive full bridge diode rectifier and an active switching full bridge rectifier. Due to the inherent line inductance of the Stirling Engine-Linear Alternator (SE-LA), their sinusoidal voltage and current will be phase shifted producing a power factor below 1. In order to keep power the factor close to unity, both AC to DC converters topologies will implement power factor correction. This paper discusses these power factor correction methods as well as their impact on overall mass for exploration applications. Simulation results on both AC to DC converters topologies with power factor correction as a function of output power and SE-LA line inductance impedance are presented and compared.

Angle detector

NASA Technical Reports Server (NTRS)

Parra, G. T. (Inventor)

1978-01-01

An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

Wrist Traction During MR Arthrography Improves Detection of Triangular Fibrocartilage Complex and Intrinsic Ligament Tears and Visibility of Articular Cartilage.

PubMed

Lee, Ryan K L; Griffith, James F; Ng, Alex W H; Nung, Ryan C H; Yeung, David K W

2016-01-01

The purpose of this study was to assess the effects of traction during MR arthrography of the wrist on joint space widening, cartilage visibility, and detection of tears of the triangular fibrocartilage complex (TFCC) and intrinsic ligaments. A prospective study included 40 wrists in 39 patients (25 men, 14 women; mean age, 35 years). MR arthrography was performed with a 3-T MRI system with and without axial traction. Two radiologists independently measured wrist and carpal joint space widths and semiquantitatively graded articular cartilage visibility. Using conventional arthrography as the reference standard and working in consensus, they assessed for the presence of tears of the TFCC, lunotriquetral ligament (LTL), and scapholunate ligament (SLL). Visibility of a tear before traction was compared with visibility after traction. With traction, all joint spaces in the wrist and carpus were significantly widened (change, 0.15-1.01 mm; all p < 0.006). Subjective cartilage visibility of all joint spaces improved after traction (all p ≤ 0.048) except for that of the radioscaphoid space, which was well visualized even before traction. Conventional arthrography depicted 24 TFCC tears, seven LTL tears, and three SLL tears. The accuracy of tear detection improved after traction for the TFCC (98% after traction vs 83% before traction), the LTL (100% vs 88%), and the SLL (100% vs 95%). Tear visibility improved after traction for 54% of TFCC tears, 71% of LTL tears, and 66% of SLL tears. Wrist MR arthrography with axial traction significantly improved the visibility of articular cartilage and the detection and visibility of tears of the TFCC and intrinsic ligaments. The results favor more widespread use of traction during MR arthrography of the wrist.

Home Cervical Traction to Reduce Neck Pain in Fighter Pilots.

PubMed

Chumbley, Eric M; O'Hair, Nicole; Stolfi, Adrienne; Lienesch, Christopher; McEachen, James C; Wright, Bruce A

2016-12-01

Most fighter pilots report cervical pain during their careers. Recommendations for remediation lack evidence. We sought to determine whether regular use of a home cervical traction device could decrease reported cervical pain in F-15C pilots. An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, controlled crossover study was undertaken with 21 male F-15C fighter pilots between February and June 2015. Of the 21 subjects, 12 completed 6 wk each of traction and control, while logging morning, postflying, and post-traction pain. Pain was compared with paired t-tests between the periods, from initial pain scores to postflying, and postflying to post-traction. In the traction phase, initial pain levels increased postflight, from 1.2 (0.7) to 1.6 (1.0) Subsequent post-traction pain levels decreased to 1.3 (0.9), with a corresponding linear decrease in pain relative to pain reported postflight. The difference in pain levels after traction compared to initial levels was not significant, indicating that cervical traction was effective in alleviating flying-related pain. Control pain increased postflight from 1.4 (0.9) to 1.9 (1.3). Daily traction phase pain was lower than the control, but insignificant. To our knowledge, this is the first study of home cervical traction to address fighter pilots' cervical pain. We found a small but meaningful improvement in daily pain rating when using cervical traction after flying. These results help inform countermeasure development for pilots flying high-performance aircraft. Further study should clarify the optimal traction dose and timing in relation to flying.Chumbley EM, O'Hair N, Stolfi A, Lienesch C, McEachen JC, Wright BA. Home cervical traction to reduce neck pain in fighter pilots. Aerosp Med Hum Perform. 2016; 87(12):1010-1015.

Ethylene biosynthesis in detached young persimmon fruit is initiated in calyx and modulated by water loss from the fruit.

PubMed

Nakano, Ryohei; Ogura, Emi; Kubo, Yasutaka; Inaba, Akitsugu

2003-01-01

Persimmon (Diospyros kaki Thunb.) fruit are usually classified as climacteric fruit; however, unlike typical climacteric fruits, persimmon fruit exhibit a unique characteristic in that the younger the stage of fruit detached, the greater the level of ethylene produced. To investigate ethylene induction mechanisms in detached young persimmon fruit, we cloned three cDNAs encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (DK-ACS1, 2, and -3) and two encoding ACC oxidase (DK-ACO1 and -2) genes involved in ethylene biosynthesis, and we analyzed their expression in various fruit tissues. Ethylene production was induced within a few days of detachment in all fruit tissues tested, accompanied by temporally and spatially coordinated expression of all the DK-ACS and DK-ACO genes. In all tissues except the calyx, treatment with 1-methylcyclopropene, an inhibitor of ethylene action, suppressed ethylene production and ethylene biosynthesis-related gene expression. In the calyx, one ACC synthase gene (DK-ACS2) exhibited increased mRNA accumulation accompanied by a large quantity of ethylene production, and treatment of the fruit with 1-methylcyclopropene did not prevent either the accumulation of DK-ACS2 transcripts or ethylene induction. Furthermore, the alleviation of water loss from the fruit significantly delayed the onset of ethylene production and the expression of DK-ACS2 in the calyx. These results indicate that ethylene biosynthesis in detached young persimmon fruit is initially induced in calyx and is modulated by water loss through transcriptional activation of DK-ACS2. The ethylene produced in the calyx subsequently diffuses to other fruit tissues and acts as a secondary signal that stimulates autocatalytic ethylene biosynthesis in these tissues, leading to a burst of ethylene production.

Ethylene Biosynthesis in Detached Young Persimmon Fruit Is Initiated in Calyx and Modulated by Water Loss from the Fruit1

PubMed Central

Nakano, Ryohei; Ogura, Emi; Kubo, Yasutaka; Inaba, Akitsugu

2003-01-01

Persimmon (Diospyros kaki Thunb.) fruit are usually classified as climacteric fruit; however, unlike typical climacteric fruits, persimmon fruit exhibit a unique characteristic in that the younger the stage of fruit detached, the greater the level of ethylene produced. To investigate ethylene induction mechanisms in detached young persimmon fruit, we cloned three cDNAs encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (DK-ACS1, 2, and -3) and two encoding ACC oxidase (DK-ACO1 and -2) genes involved in ethylene biosynthesis, and we analyzed their expression in various fruit tissues. Ethylene production was induced within a few days of detachment in all fruit tissues tested, accompanied by temporally and spatially coordinated expression of all the DK-ACS and DK-ACO genes. In all tissues except the calyx, treatment with 1-methylcyclopropene, an inhibitor of ethylene action, suppressed ethylene production and ethylene biosynthesis-related gene expression. In the calyx, one ACC synthase gene (DK-ACS2) exhibited increased mRNA accumulation accompanied by a large quantity of ethylene production, and treatment of the fruit with 1-methylcyclopropene did not prevent either the accumulation of DK-ACS2 transcripts or ethylene induction. Furthermore, the alleviation of water loss from the fruit significantly delayed the onset of ethylene production and the expression of DK-ACS2 in the calyx. These results indicate that ethylene biosynthesis in detached young persimmon fruit is initially induced in calyx and is modulated by water loss through transcriptional activation of DK-ACS2. The ethylene produced in the calyx subsequently diffuses to other fruit tissues and acts as a secondary signal that stimulates autocatalytic ethylene biosynthesis in these tissues, leading to a burst of ethylene production. PMID:12529535

The impact of the neurodevelopmental traction technique on activation of lateral abdominal muscles in children aged 11-13 years.

PubMed

Gogola, Anna; Gnat, Rafał; Dziub, Dorota; Gwóźdź, Michalina; Zaborowska, Małgorzata

2016-06-27

The aim of the study was to evaluate the activation of lateral abdominal muscles (LAM) in response to neurodevelopmental traction technique as assessed by ultrasounds as well as to compare the effects of different traction forces. An experiment with repeated measurements of the dependent variables was conducted. Thirty-seven children (22 girls) participated. Measurements of LAM thickness (indicating LAM activation) were performed bilaterally during traction of 5% body weight: 1) in neutral position, 2) in 20° posterior trunk inclination; during traction of 15% body weight: 3) in neutral position, 4) in 20° posterior trunk inclination. The ultrasound technology was employed. When applying the lighter traction the superficial LAM (external and internal oblique muscles) showed significant changes. The mean thickness of both muscles during traction increased (both p < 0.001). The deepest transversus abdominis showed no response (p > 0.05). Stronger traction elicited smaller changes. External and internal oblique muscles showed significant increases (p < 0.001, p < 0.01, respectively). Transversus abdominis became less thick during stronger traction (p < 0.01). The neurodevelopmental traction technique elicits the changes in LAM thickness in children with typical development. The superficial LAM show more distinct responses than the profound LAM. Stronger traction induces smaller LAM thickness changes than lighter traction.

Activation of Extracellular Signal-Regulated Kinase in the Anterior Cingulate Cortex Contributes to the Induction and Expression of Affective Pain

PubMed Central

Cao, Hong; Gao, Yong-Jing; Ren, Wen-Hua; Li, Ting-Ting; Duan, Kai-Zheng; Cui, Yi-Hui; Cao, Xiao-Hua; Zhao, Zhi-Qi; Ji, Ru-Rong; Zhang, Yu-Qiu

2009-01-01

The anterior cingulate cortex (ACC) is implicated in the affective response to noxious stimuli. However, little is known about the molecular mechanisms involved. The present study demonstrated that extracellular signal-regulated kinase (ERK) activation in the ACC plays a crucial role in pain-related negative emotion. Intraplantar formalin injection produced a transient ERK activation in laminae V–VI and a persistent ERK activation in laminae II–III of the rostral ACC (rACC) bilaterally. Using formalin-induced conditioned place avoidance (F-CPA) in rats, which is believed to reflect the pain-related negative emotion, we found that blockade of ERK activation in the rACC with MEK inhibitors prevented the induction of F-CPA. Interestingly, this blockade did not affect formalin-induced two-phase spontaneous nociceptive responses and CPA acquisition induced by electric foot-shock or U69,593, an innocuous aversive agent. Upstream, NMDA receptor, adenylyl cyclase (AC) and PKA activators activated ERK in rACC slices. Consistently, intra-rACC microinjection of AC or PKA inhibitors prevented F-CPA induction. Downstream, phosphorylation of cAMP response element binding protein (CREB) was induced in the rACC by formalin injection and by NMDA, AC and PKA activators in brain slices, which was suppressed by MEK inhibitors. Furthermore, ERK also contributed to the expression of pain-related negative emotion. Thus, when rats were re-exposed to the conditioning context for retrieval of pain experience, ERK and CREB were re-activated in the rACC, and inhibiting ERK activation blocked the expression of F-CPA. All together, our results demonstrate that ERK activation in the rACC is required for the induction and expression of pain-related negative affect. PMID:19279268

Neutrophil elastase increases MUC5AC mRNA and protein expression in respiratory epithelial cells.

PubMed

Voynow, J A; Young, L R; Wang, Y; Horger, T; Rose, M C; Fischer, B M

1999-05-01

Chronic neutrophil-predominant inflammation and hypersecretion of mucus are common pathophysiological features of cystic fibrosis, chronic bronchitis, and viral- or pollution-triggered asthma. Neutrophils release elastase, a serine protease, that causes increased mucin production and secretion. The molecular mechanisms of elastase-induced mucin production are unknown. We hypothesized that as part of this mechanism, elastase upregulates expression of a major respiratory mucin gene, MUC5AC. A549, a human lung carcinoma cell line that expresses MUC5AC mRNA and protein, and normal human bronchial epithelial cells in an air-liquid interface culture were stimulated with neutrophil elastase. Neutrophil elastase increased MUC5AC mRNA levels in a time-dependent manner in both cell culture systems. Neutrophil elastase treatment also increased MUC5AC protein levels in A549 cells. The mechanism of MUC5AC gene regulation by elastase was determined in A549 cells. The induction of MUC5AC gene expression required serine protease activity; other classes of proteases had no effect on MUC5AC gene expression. Neutrophil elastase increased MUC5AC mRNA levels by enhancing mRNA stability. This is the first report of mucin gene regulation by this mechanism.

Induction voidmeter

DOEpatents

Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.

1983-12-21

An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; means for applying an AC excitation signal to said input branch; and means for detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

Evaluation of the in vivo genotoxicity of Allura Red AC (Food Red No. 40).

PubMed

Honma, Masamitsu

2015-10-01

Allura Red AC (Food Red No. 40) is a red azo dye that is used for food coloring in beverage and confectionary products. However, its genotoxic properties remain controversial. To clarify the in vivo genotoxicity, we treated mice with Allura Red AC and investigated the induction of DNA damage (liver, glandular stomach), clastogenicity/anuegenicity (bone marrow), and mutagenicity (liver, glandular stomach) using Comet assays, micronucleus tests, and transgenic gene mutation assays, respectively. All studies were conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guideline. Although Allura Red AC was administered up to the maximum doses recommended by the OECD guideline, no genotoxic effect was observed in any of the genotoxic endpoints. These data clearly show no evidence of in vivo genotoxic potential of Allura Red AC administered up to the maximum doses in mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Puncture point-traction method: A novel method applied for right internal jugular vein catheterization

PubMed Central

WU, TIANLIANG; ZANG, HONGCHENG

2016-01-01

The ultrasound probe and advancement of the needle during real-time ultrasound-assisted guidance of catheterization of the right internal jugular vein (RIJV) tend to collapse the vein, which reduces the success rate of the procedure. We have developed a novel puncture point-traction method (PPTM) to facilitate RIJV cannulation. The present study examined whether this method facilitated the performance of RIJV catheterization in anesthetized patients. In this study, 120 patients were randomly assigned to a group in which PPTM was performed (PPTM group, n=60) or a group in which it was not performed (non-PPTM group, n=60). One patient was excluded because of internal carotid artery puncture and 119 patients remained for analysis. The cross-sectional area (CSA), anteroposterior diameter (AD) and transverse diameter (TD) of the RIJV at the cricoid cartilage level following the induction of anesthesia and during catheterization were measured, and the number with obvious loss of resistance (NOLR), the number with easy aspiration of blood into syringe (NEABS) during advancement of the needle, and the number of first-pass punctures (NFPP) during catheterization were determined. In the non-PPTM group, the CSA was smaller during catheterization compared with that following the induction of anesthesia (P<0.01). In the PPTM group compared with the non-PPTM group during catheterization, the CSA was larger (P<0.01) and the AD (P<0.01) and TD (P<0.05) were wider; NOLR (P<0.01), NEABS (P<0.01) and NFPP (P<0.01) increased significantly. The findings from this study confirmed that the PPTM facilitated catheterization of the RIJV and improved the success rate of RIJV catheterization in anesthetized patients in the supine position. PMID:27347054

Fundamentals of electric power conversion. Volume 2, Energy-efficient polyphase AC induction motors, final report

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

Umans, S.D.

1992-12-01

Its rugged nature and straightforward design make the induction motor the most commonly used type of electric motor. This motor ranges in size fro the fractional-horsepower, single-phase motors found in household appliances to polyphase motors rated at thousands of horsepower for industrial applications. Volume 1 of this report describes the function of induction motors, their characteristics, and induction motor testing. Volume 2 describes the characteristics of high-efficiency induction motors, with emphasis on the techniques used to obtain high efficiency. This two-volume report is written in nontechnical language and is intended for readers who require background from applications, marketing, motor planning,more » or managerial perspective.« less

Fundamentals of electric power conversion. Volume 1, Operating characteristics and testing of AC induction motors, final report

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

Umans, S.D.

1992-12-01

Its rugged nature and straightforward design make the induction motor the most commonly used type of electric motor. This motor ranges in size from the fractional-horsepower, single-phase motors found in household appliances to polyphase motors rated at thousands of horsepower for industrial applications. Volume 1 of this report describes the function of induction motors, their characteristics, and induction motor testing. Volume 2 describes the characteristics of high-efficiency induction motors, with emphasis on the techniques used to obtain high efficiency. This two-volume report is written in nontechnical language and is intended for readers who require background from an applications, marketing, motormore » planning, or managerial perspective.« less

Emerging nonsurgical methods for the treatment of vitreomacular adhesion: a review

PubMed Central

Schneider, Eric W; Johnson, Mark W

2011-01-01

With the dissemination of optical coherence tomography over the past two decades, the role of persistent vitreomacular adhesion (VMA) in the development of numerous macular pathologies – including idiopathic macular hole, vitreomacular traction syndrome, cystoid and diabetic macular edema, neovascularization in diabetic retinopathy and retinal vein occlusion, exudative age-related macular degeneration, and myopic traction maculopathy – has been established. While invasive vitreoretinal procedures have long been utilized to address complications related to these disorders, such an approach is hampered by incomplete vitreoretinal separation and vitreous removal, surgical complications, and high costs. In light of such limitations, investigators have increasingly looked to nonsurgical means for the treatment of persistent pathologic VMA. Chief among these alternative measures is the intravitreal application of pharmacologic agents for the induction of vitreous liquefaction and/or vitreoretinal separation, an approach termed pharmacologic vitreolysis. This article aims to review the available evidence regarding the use of pharmacologic agents in the treatment of VMA-related pathology. In addition, a discussion of vitreous molecular organization and principles of physiologic posterior vitreous detachment is provided to allow for a consideration of vitreolytic agent mode of action and molecular targets. PMID:21887098

Axial traction magnetic resonance imaging (MRI) of the glenohumeral joint in healthy volunteers: initial experience.

PubMed

Garwood, Elisabeth R; Souza, Richard B; Zhang, Amy; Zhang, Alan L; Ma, C Benjamin; Link, Thomas M; Motamedi, Daria

Evaluate technical feasibility and potential applications of glenohumeral (GH) joint axial traction magnetic resonance imaging (MRI) in healthy volunteers. Eleven shoulders were imaged in neutral and with 4kg axial traction at 3T. Quantitative measurements were assessed. Axial traction was well tolerated. There was statistically significant widening of the superior GH joint space (p=0.002) and acromial angle (p=0.017) with traction. Inter-rater agreement was high. GH joint axial traction MRI is technically feasible and well tolerated in volunteers. Traction of the capsule, widening of the superior GH joint space and acromial angle were observed. Copyright © 2017 Elsevier Inc. All rights reserved.

Revisiting the electrochemical impedance spectroscopy of magnesium with online inductively coupled plasma atomic emission spectroscopy.

PubMed

Shkirskiy, Viacheslav; King, Andrew D; Gharbi, Oumaïma; Volovitch, Polina; Scully, John R; Ogle, Kevin; Birbilis, Nick

2015-02-23

The electrochemical impedance of reactive metals such as magnesium is often complicated by an obvious inductive loop with decreasing frequency of the AC polarising signal. The characterisation and ensuing explanation of this phenomenon has been lacking in the literature to date, being either ignored or speculated. Herein, we couple electrochemical impedance spectroscopy (EIS) with online atomic emission spectroelectrochemistry (AESEC) to simultaneously measure Mg-ion concentration and electrochemical impedance spectra during Mg corrosion, in real time. It is revealed that Mg dissolution occurs via Mg(2+) , and that corrosion is activated, as measured by AC frequencies less than approximately 1 Hz approaching DC conditions. The result of this is a higher rate of Mg(2+) dissolution, as the voltage excitation becomes slow enough to enable all Mg(2+) -enabling processes to adjust in real time. The manifestation of this in EIS data is an inductive loop. The rationalisation of such EIS behaviour, as it relates to Mg, is revealed for the first time by using concurrent AESEC. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CFAVC scheme for high frequency series resonant inverter-fed domestic induction heating system

NASA Astrophysics Data System (ADS)

Nagarajan, Booma; Reddy Sathi, Rama

2016-01-01

This article presents the investigations on the constant frequency asymmetric voltage cancellation control in the AC-AC resonant converter-fed domestic induction heating system. Conventional fixed frequency control techniques used in the high frequency converters lead to non-zero voltage switching operation and reduced output power. The proposed control technique produces higher output power than the conventional fixed-frequency control strategies. In this control technique, zero-voltage-switching operation is maintained during different duty cycle operation for reduction in the switching losses. Complete analysis of the induction heating power supply system with asymmetric voltage cancellation control is discussed in this article. Simulation and experimental study on constant frequency asymmetric voltage cancellation (CFAVC)-controlled full bridge series resonant inverter is performed. Time domain simulation results for the open and closed loop of the system are obtained using MATLAB simulation tool. The simulation results prove the control of voltage and power in a wide range. PID controller-based closed loop control system achieves the voltage regulation of the proposed system for the step change in load. Hardware implementation of the system under CFAVC control is done using the embedded controller. The simulation and experimental results validate the performance of the CFAVC control technique for series resonant-based induction cooking system.

Traction contact performance evaluation at high speeds

NASA Technical Reports Server (NTRS)

Tevaarwerk, J. L.

1981-01-01

The results of traction tests performed on two fluids are presented. These tests covered a pressure range of 1.0 to 2.5 GPa, an inlet temperature range of 30 'C to 70 'C, a speed range of 10 to 80 m/sec, aspect ratios of .5 to 5 and spin from 0 to 2.1 percent. The test results are presented in the form of two dimensionless parameters, the initial traction slope and the maximum traction peak. With the use of a suitable rheological fluid model the actual traction curves measured can now be reconstituted from the two fluid parameters. More importantly, the knowledge of these parameters together with the fluid rheological model, allow the prediction of traction under conditions of spin, slip and any combination thereof. Comparison between theoretically predicted traction under these conditions and those measured in actual traction tests shows that this method gives good results.

Application of traction drives as servo mechanisms

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Rohn, D. A.; Steinetz, B. M.

1985-01-01

The suitability of traction drives for a wide class of aerospace control mechanisms is examined. Potential applications include antenna or solar array drive positioners, robotic joints, control moment gyro (CMG) actuators and propeller pitch change mechanisms. In these and similar applications the zero backlash, high torsional stiffness, low hysteresis and torque ripple characteristics of traction drives are of particular interest, as is the ability to run without liquid lubrication in certain cases. Wear and fatigue considerations for wet and dry operation are examined along with the tribological performance of several promising self lubricating polymers for traction contracts. The speed regulation capabilities of variable ratio traction drives are reviewed. A torsional stiffness analysis described suggests that traction contacts are relatively stiff compared to gears and are significantly stiffer than the other structural elements in the prototype CMG traction drive analyzed. Discussion is also given of an advanced turboprop propeller pitch change mechanism that incorporates a traction drive.

Counter traction makes endoscopic submucosal dissection easier.

PubMed

Oyama, Tsuneo

2012-11-01

Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

Measuring Accurately Single-Phase Sinusoidal and Non-Sinusoidal Power.

DTIC Science & Technology

1983-01-01

current component. Since the induction watthour meter is designed for measuring ac variations only, the creation of a dc component in an ac circuit due...available and the basic principle of measurement used in each. 3.1 Power Measuring Meters Instruments designed to measure the amount of average power...1.0 percent of full scale and + 0.5% of reading. 3.2 Encrgy Measuring Meters Instruments designed to measure the amount of power consumed in a circuit

Halo-gravity traction in the treatment of severe spinal deformity: a systematic review and meta-analysis.

PubMed

Yang, Changsheng; Wang, Huafeng; Zheng, Zhaomin; Zhang, Zhongmin; Wang, Jianru; Liu, Hui; Kim, Yongjung Jay; Cho, Samuel

2017-07-01

Halo-gravity traction has been reported to successfully assist in managing severe spinal deformity. This is a systematic review of all studies on halo-gravity traction in the treatment of spinal deformity to provide information for clinical practice. A comprehensive search was conducted for articles on halo-gravity traction in the treatment of spinal deformity according to the PRISMA guidelines. Appropriate studies would be included and analyzed. Preoperative correction rate of spinal deformity, change of pulmonary function and prevalence of complications were the main measurements. Sixteen studies, a total of 351 patients, were included in this review. Generally, the initial Cobb angle was 101.1° in the coronal plane and 80.5° in the sagittal plane, and it was corrected to 49.4° and 56.0° after final spinal fusion. The preoperative correction due to traction alone was 24.1 and 19.3%, respectively. With traction, the flexibility improved 6.1% but postoperatively the patients did not have better correction. Less aggressive procedures and improved pulmonary function were observed in patients with traction. The prevalence of traction-related complications was 22% and three cases of neurologic complication related to traction were noted. The prevalence of total complications related to surgery was 32% and that of neurologic complications was 1%. Partial correction could be achieved preoperatively with halo-gravity traction, and it may help decrease aggressive procedures, improve preoperative pulmonary function, and reduce neurologic complications. However, traction could not increase preoperative flexibility or final correction. Traction-related complications, although usually not severe, were not rare.

Power Electronic Transformer based Three-Phase PWM AC Drives

NASA Astrophysics Data System (ADS)

Basu, Kaushik

A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common-mode voltage suppression at the load end, 3) High quality output voltage waveform (comparable to conventional space vector PWM modulated two level inverter) and 4) Minimization of output voltage loss, common-mode voltage switching and distortion of the load current waveform due to leakage inductance commutation. All of the proposed topologies along with the proposed control schemes have been analyzed and simulated in MATLABSimulink. A hardware prototype has been fabricated and tested. The simulation and experimental results verify the operation and advantages of the proposed topologies and their control.

Traction in smooth muscle cells varies with cell spreading

NASA Technical Reports Server (NTRS)

Tolic-Norrelykke, Iva Marija; Wang, Ning

2005-01-01

Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

Traction cytometry: regularization in the Fourier approach and comparisons with finite element method.

PubMed

Kulkarni, Ankur H; Ghosh, Prasenjit; Seetharaman, Ashwin; Kondaiah, Paturu; Gundiah, Namrata

2018-05-09

Traction forces exerted by adherent cells are quantified using displacements of embedded markers on polyacrylamide substrates due to cell contractility. Fourier Transform Traction Cytometry (FTTC) is widely used to calculate tractions but has inherent limitations due to errors in the displacement fields; these are mitigated through a regularization parameter (γ) in the Reg-FTTC method. An alternate finite element (FE) approach computes tractions on a domain using known boundary conditions. Robust verification and recovery studies are lacking but essential in assessing the accuracy and noise sensitivity of the traction solutions from the different methods. We implemented the L2 regularization method and defined a maximum curvature point in the traction with γ plot as the optimal regularization parameter (γ*) in the Reg-FTTC approach. Traction reconstructions using γ* yield accurate values of low and maximum tractions (Tmax) in the presence of up to 5% noise. Reg-FTTC is hence a clear improvement over the FTTC method but is inadequate to reconstruct low stresses such as those at nascent focal adhesions. FE, implemented using a node-by-node comparison, showed an intermediate reconstruction compared to Reg-FTTC. We performed experiments using mouse embryonic fibroblast (MEF) and compared results between these approaches. Tractions from FTTC and FE showed differences of ∼92% and 22% as compared to Reg-FTTC. Selection of an optimum value of γ for each cell reduced variability in the computed tractions as compared to using a single value of γ for all the MEF cells in this study.

Alocasia cucullata exhibits strong antitumor effect in vivo by activating antitumor immunity.

PubMed

Peng, Qiuxian; Cai, Hongbing; Sun, Xuegang; Li, Xin; Mo, Zhixian; Shi, Jue

2013-01-01

Chinese herbal medicines have long been used to treat various illnesses by modulating the human immune response. In this study, we investigate the immuno-modulating effect and antitumor activity of Alocasia Cucullata (AC), a Chinese herb traditionally used to treat infection and cancer. We found that the whole water extract of AC roots could significantly attenuate tumor growth in mouse tumor models. The median survival time of the AC-treated mice was 43 days, 16 days longer than that of the control group. Moreover, the AC-treated mice showed substantially higher induction of key antitumor cytokines, such as IL-2, IFN-γ, and TNF-α, indicating that AC may exert antitumor effect by activating antitumor immunity. To further pinpoint the cellular and molecular mechanism of AC, we studied the dose response of a human monocytic cell line, THP-1, to the whole water extract of AC. Treatment of the AC extract significantly induced THP-1 differentiation into macrophage-like cells and the differentiated THP-1 showed expression of specific macrophage surface markers, such as CD11b and CD14, as well as productions of antitumor cytokines, e.g. IFN-γ and TNF-α. Our data thus point to AC as potentially a new, alternative immuno-modulating herbal remedy for anticancer treatment.

Effect of traction on wrist joint space and cartilage visibility with and without MR arthrography

PubMed Central

Griffith, James F; Tang, W K; Ng, Alex W H; Yeung, David K W

2017-01-01

Objective: To compare the effect of traction during non-arthrographic and arthrographic MR examination of the wrist with regard to joint space width, joint fluid dispersion and cartilage surface visibility. Methods: Prospective 3-T MRI study of 100 wrists in 96 patients. The first 50 wrists underwent MR arthrography first without traction and then with traction. The following 50 wrists underwent standard MR first without traction and then with traction. On these examinations, two radiologists independently measured (i) joint space width, semi-quantitatively graded (ii) joint fluid dispersion between opposing cartilage surfaces and (iii) articular cartilage surface visibility. The three parameters were compared between the two groups. Results: Traction led to an increase in joint space width at nearly all joints in all patients (p < 0.05), although more so in the arthrography (∆ = 0.08–0.79 mm, all p < 0.05) than in the non-arthrography (∆ = 0.001–0.61 mm, all p < 0.05) group. Joint fluid dispersion and cartilage surface visibility improved after traction in nearly all joints (p < 0.05) in all patients and more so in the arthographic than in the non-arthrography group. Conclusion: Traction did significantly improve cartilage surface visibility for standard MRI of the wrist although the effect was not as great as that seen with MR arthography or MR arthrography with traction. Advances in knowledge: This is the first study to show the beneficial effect of traction during standard non-arthrography MRI of the wrist and compare the effect of traction between non-arthrographic and arthrographic MRI of the wrist. PMID:28181830

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

Chinthavali, Madhu Sudhan; Onar, Omer C; Campbell, Steven L

Integrated charger topologies that have been researched so far with dc-dc converters and the charging functionality have no isolation in the system. Isolation is an important feature that is required for user interface systems that have grid connections and therefore is a major limitation that needs to be addressed along with the integrated functionality. The topology proposed in this paper is a unique and a first of its kind topology that integrates a wireless charging system and the boost converter for the traction drive system. The new topology is also compared with an on-board charger system from a commercial electricmore » vehicle (EV). The ac-dc efficiency of the proposed system is 85.05% and the specific power and power density of the onboard components is ~455 W/kg and ~302 W/ .« less

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

Chinthavali, Madhu Sudhan; Onar, Omer C; Campbell, Steven L

Integrated charger topologies that have been researched so far with dc-dc converters and the charging functionality have no isolation in the system. Isolation is an important feature that is required for user interface systems that have grid connections and therefore is a major limitation that needs to be addressed along with the integrated functionality. The topology proposed in this paper is a unique and a first of its kind topology that integrates a wireless charging system and the boost converter for the traction drive system. The new topology is also compared with an on-board charger system from a commercial electricmore » vehicle (EV). The ac-dc efficiency of the proposed system is 85.1% and the specific power and power density of the onboard components is ~455 W/kg and ~320 W/ .« less

Bcl-2△21 and Ac-DEVD-CHO Inhibit Death of Wheat Microspores

PubMed Central

Sinha, Rakesh K.; Pospíšil, Pavel; Maheshwari, Priti; Eudes, François

2016-01-01

Microspore cell death and low green plant production efficiency are an integral obstacle in the development of doubled haploid production in wheat. The aim of the current study was to determine the effect of anti-apoptotic recombinant human B-cell lymphoma-2 (Bcl-2△21) and caspase-3-inhibitor (Ac-DEVD-CHO) in microspore cell death in bread wheat cultivars AC Fielder and AC Andrew. Induction medium containing Bcl-2△21 and Ac-DEVD-CHO yielded a significantly higher number of viable microspores, embryo-like structures and total green plants in wheat cultivars AC Fielder and AC Andrew. Total peroxidase activity was lower in Bcl-2△21 treated microspore cultures at 96 h of treatment compared to control and Ac-DEVD-CHO. Electron paramagnetic resonance study of total microspore protein showed a different scavenging activity for Bcl-2△21 and Ac-DEVD-CHO. Bcl-2△21 scavenged approximately 50% hydroxyl radical (HO•) formed, whereas Ac-DEVD-CHO scavenged approximately 20% of HO•. Conversely, reduced caspase-3-like activities were detected in the presence of Bcl-2△21 and Ac-DEVD-CHO, supporting the involvement of Bcl-2△21 and Ac-DEVD-CHO in increasing microspore viability by reducing oxidative stress and caspase-3-like activity. Our results indicate that Bcl-2△21 and Ac-DEVD-CHO protects cells from cell death following different pathways. Bcl-2△21 prevents cell damage by detoxifying HO• and suppressing caspase-3-like activity, while Ac-DEVD-CHO inhibits the cell death pathways by modulating caspase-like activity. PMID:28082995

An AC-electromagnetic bearing for flywheel energy storage in space

NASA Technical Reports Server (NTRS)

Nikolajsen, Jorgen L.

1993-01-01

A repulsive type AC-electromagnetic bearing was developed and tested. It was conceived on the basis of the so-called Magnetic River suspension for high-speed trains. The appearance of the bearing is similar to the traditional DC-type electromagnetic bearing but the operating principle is different. The magnets are fed with alternating current instead of direct current and the rotor is fitted with a conducting sleeve (e.g. aluminum) instead of a ferromagnetic sleeve. The repulsion is due to induction of eddy-currents in the conducting sleeve. The bearing is inherently stable and requires no feedback control. It provides support in five degrees of freedom such that a short rotor may be fully supported by a single bearing. These capabilities were demonstrated experimentally. On the down side, the load carrying capacity and the damping obtained so far were quite low compared to the DC-type bearing. Also, significant heating of the conducting sleeve was experienced. The AC-bearing is essentially a modified induction motor and there are strong indications that it can be run both as a motor and as a generator with no commutator requirements. It is therefore considered to be a good candidate for support of energy storage flywheels in space.

Use of an AC induction motor system for producing finger movements in human subjects.

PubMed

Proudlock, F A; Scott, J J

1998-12-01

This report describes the set-up and evaluation of a novel system for producing precise finger movements, for tests of movement perception. The specifications were to construct a system using commercially available components that were easy to use but which offered both flexibility and also high precision control. The system was constructed around an industrial AC induction motor with an optical encoder, controlled by an AC servo digital control module that could be programmed using a simple, high-level language. This set-up fulfilled the requirements regarding position and velocity control for a range of movements and also the facility for the subject to move the joint voluntarily while still attached to the motor. However a number of problems were encountered, the most serious being the level of vibration and the inability to vary the torque during movements. The vibration was reduced to the point where it did not affect the subject, by the introduction of mechanical dampening using an anti-vibration coupling and a pneumatic splint. The torque control could not be modified during rotation and so the system could only be operated using constant torque for any given movement.

Resistance of Malus domestica fruit to Botrytis cinerea depends on endogenous ethylene biosynthesis.

PubMed

Akagi, Aya; Dandekar, Abhaya M; Stotz, Henrik U

2011-11-01

The plant hormone ethylene regulates fruit ripening, other developmental processes, and a subset of defense responses. Here, we show that 1-aminocyclopropane-1-carboxylic acid synthase (ACS)-silenced apple (Malus domestica) fruit that express a sense construct of ACS were more susceptible to Botrytis cinerea than untransformed apple, demonstrating that ethylene strengthens fruit resistance to B. cinerea infection. Because ethylene response factors (ERFs) are known to contribute to resistance against B. cinerea via the ethylene-signaling pathway, we cloned four ERF cDNAs from fruit of M. domestica: MdERF3, -4, -5, and -6. Expression of all four MdERF mRNAs was ethylene dependent and induced by wounding or by B. cinerea infection. B. cinerea infection suppressed rapid induction of wound-related MdERF expression. MdERF3 was the only mRNA induced by wounding and B. cinerea infection in ACS-suppressed apple fruit, although its induction was reduced compared with wild-type apple. Promoter regions of all four MdERF genes were cloned and putative cis-elements were identified in each promoter. Transient expression of MdERF3 in tobacco increased expression of the GCC-box containing gene chitinase 48.

Diagnostic performance of direct traction MR arthrography of the hip: detection of chondral and labral lesions with arthroscopic comparison.

PubMed

Schmaranzer, Florian; Klauser, Andrea; Kogler, Michael; Henninger, Benjamin; Forstner, Thomas; Reichkendler, Markus; Schmaranzer, Ehrenfried

2015-06-01

To assess diagnostic performance of traction MR arthrography of the hip in detection and grading of chondral and labral lesions with arthroscopic comparison. Seventy-five MR arthrograms obtained ± traction of 73 consecutive patients (mean age, 34.5 years; range, 14-54 years) who underwent arthroscopy were included. Traction technique included weight-adapted traction (15-23 kg), a supporting plate for the contralateral leg, and intra-articular injection of 18-27 ml (local anaesthetic and contrast agent). Patients reported on neuropraxia and on pain. Two blinded readers independently assessed femoroacetabular cartilage and labrum lesions which were correlated with arthroscopy. Interobserver agreement was calculated using κ values. Joint distraction ± traction was evaluated in consensus. No procedure had to be stopped. There were no cases of neuropraxia. Accuracy for detection of labral lesions was 92 %/93 %, 91 %/83 % for acetabular lesions, and 92 %/88 % for femoral cartilage lesions for reader 1/reader 2, respectively. Interobserver agreement was moderate (κ = 0.58) for grading of labrum lesions and substantial (κ = 0.7, κ = 0.68) for grading of acetabular and femoral cartilage lesions. Joint distraction was achieved in 72/75 and 14/75 hips with/without traction, respectively. Traction MR arthrography safely enabled accurate detection and grading of labral and chondral lesions. • The used traction technique was well tolerated by most patients. • The used traction technique almost consistently achieved separation of cartilage layers. • Traction MR arthrography enabled accurate detection of chondral and labral lesions.

21 CFR 882.5960 - Skull tongs for traction.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull tongs for traction. 882.5960 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5960 Skull tongs for traction. (a) Identification. Skull tongs for traction is an instrument used to immobilize a patient with a...

21 CFR 888.5850 - Nonpowered orthopedic traction apparatus and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonpowered orthopedic traction apparatus and accessories. 888.5850 Section 888.5850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... orthopedic traction apparatus and accessories. (a) Identification. A nonpowered orthopedic traction apparatus...

21 CFR 888.5850 - Nonpowered orthopedic traction apparatus and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonpowered orthopedic traction apparatus and accessories. 888.5850 Section 888.5850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... orthopedic traction apparatus and accessories. (a) Identification. A nonpowered orthopedic traction apparatus...

Frequency, field, and temperature dependence of the AC penetration depth of a GdBa 2Cu 3O 7-δ film in the mixed state

NASA Astrophysics Data System (ADS)

Zeisberger, M.; Klupsch, Th.; Michalke, W.

1995-02-01

We report on a systematic mutual induction measurement of the complex AC penetration depth λ of a sputtered high-quality GdBa 2Cu 3O 7-δ film in the mixed state by a very small coil system arranged near the sample surface. The complex penetration depth λ( B, T, ω) for DC inductions B ⩽ 0.65 T (perpendicular to the film), for temperatures 36 K ⩽ T ⩽ 81 K, and for frequencies 1 kHz ⩽ ω/2 π ⩽ 500 kHz was determined from the measured signal by a novel inversion scheme. The results are consistent with theoretical predictions based upon single vortex pinning. The Labusch parameter α, the flux creep relaxation time τ, as well as the effective activation energy U are simulateneously determined.

Coaxial Helicity Injection experiments in NSTX*

NASA Astrophysics Data System (ADS)

Raman, R.; Jarboe, T. R.; Gates, D.; Mueller, D.; Schaffer, M. J.; Maqueda, R.; Nelson, B. A.; Menard, J.; Soukhanovskii, V.; Paul, S.; Jardin, S.; Skinner, C. H.; Sabbagh, S.; Paoletti, F.; Stutman, D.; Lao, L.; Nagata, M.

2001-10-01

Coaxial helicity injection (CHI) can potentially eliminate inductive startup and thus the induction solenoid in spherical tori (ST), thereby greatly improving the ST fusion concept. CHI experiments on NSTX have produced 360 kA of toroidal current using about 25 kA of injector current. These have been produced in the preferred 'narrow flux foot print' condition in pulses that were sustained for 300 ms. A rotating n=1 mode, previously observed in optimized discharges on smaller STs driven by CHI and deemed necessary for transporting edge driven current to the interior of the discharge, has been observed for the first time in NSTX CHI discharges. The flux utilization efficiency continues to be high, approaching 100%. EFIT and TSC codes are being used to assess flux closure. This work is supported by the US DOE contract numbers: DE-AC02-76CH03073 and DE-AC05-00R22725.

Hybrid renewable energy system using doubly-fed induction generator and multilevel inverter

NASA Astrophysics Data System (ADS)

Ahmed, Eshita

The proposed hybrid system generates AC power by combining solar and wind energy converted by a doubly-fed induction generator (DFIG). The DFIG, driven by a wind turbine, needs rotor excitation so the stator can supply a load or the grid. In a variable-speed wind energy system, the stator voltage and its frequency vary with wind speed, and in order to keep them constant, variable-voltage and variable-frequency rotor excitation is to be provided. A power conversion unit supplies the rotor, drawing power either from AC mains or from a PV panel depending on their availability. It consists of a multilevel inverter which gives lower harmonic distortion in the stator voltage. Maximum power point tracking techniques have been implemented for both wind and solar power. The complete hybrid renewable energy system is implemented in a PSIM-Simulink interface and the wind energy conversion portion is realized in hardware using dSPACE controller board.

Myocardial and Peripheral Ischemia Causes an Increase in Circulating Pregnancy-Associated Plasma Protein-A in Non-atherosclerotic, Non-heparinized Pigs.

PubMed

Steffensen, Lasse Bach; Poulsen, Christian Bo; Shim, Jeong; Bek, Marie; Jacobsen, Kevin; Conover, Cheryl A; Bentzon, Jacob Fog; Oxvig, Claus

2015-12-01

The usefulness of circulating pregnancy-associated plasma protein-A (PAPP-A) as a biomarker for acute coronary syndrome (ACS) is widely debated. We used the pig as a model to assess PAPP-A dynamics in the setting of myocardial ischemia. Induction of myocardial ischemia by ligation of the left anterior descending (LAD) coronary artery caused a systemic rise in PAPP-A. However, the ischemic myocardium was excluded as the source of PAPP-A. Interestingly, induction of ischemia in peripheral tissues by ligation of the left femoral artery caused a systemic rise in PAPP-A originating from the left hind limb. This is the first study to demonstrate PAPP-A elevations in the absence of atherosclerosis or heparin during myocardial ischemia. Our findings thus add to the current discussion of the usefulness of PAPP-A as a biomarker for ACS.

Traction for low-back pain with or without sciatica.

PubMed

Wegner, Inge; Widyahening, Indah S; van Tulder, Maurits W; Blomberg, Stefan E I; de Vet, Henrica Cw; Brønfort, Gert; Bouter, Lex M; van der Heijden, Geert J

2013-08-19

Traction has been used to treat low-back pain (LBP), often in combination with other treatments. We included both manual and machine-delivered traction in this review. This is an update of a Cochrane review first published in 1995, and previously updated in 2006. To assess the effects of traction compared to placebo, sham traction, reference treatments and no treatment in people with LBP. We searched the Cochrane Back Review Group Specialized Register, the Cochrane Central Register of Controlled Trials (2012, Issue 8), MEDLINE (January 2006 to August 2012), EMBASE (January 2006 to August 2012), CINAHL (January 2006 to August 2012), and reference lists of articles and personal files. The review authors are not aware of any important new randomized controlled trial (RCTs) on this topic since the date of the last search. RCTs involving traction to treat acute (less than four weeks' duration), subacute (four to 12 weeks' duration) or chronic (more than 12 weeks' duration) non-specific LBP with or without sciatica. Two review authors independently performed study selection, risk of bias assessment and data extraction. As there were insufficient data for statistical pooling, we performed a descriptive analysis. We did not find any case series that identified adverse effects, therefore we evaluated adverse effects that were reported in the included studies. We included 32 RCTs involving 2762 participants in this review. We considered 16 trials, representing 57% of all participants, to have a low risk of bias based on the Cochrane Back Review Group's 'Risk of bias' tool.For people with mixed symptom patterns (acute, subacute and chronic LBP with and without sciatica), there was low- to moderate-quality evidence that traction may make little or no difference in pain intensity, functional status, global improvement or return to work when compared to placebo, sham traction or no treatment. Similarly, when comparing the combination of physiotherapy plus traction with physiotherapy alone or when comparing traction with other treatments, there was very-low- to moderate-quality evidence that traction may make little or no difference in pain intensity, functional status or global improvement.For people with LBP with sciatica and acute, subacute or chronic pain, there was low- to moderate-quality evidence that traction probably has no impact on pain intensity, functional status or global improvement. This was true when traction was compared with controls and other treatments, as well as when the combination of traction plus physiotherapy was compared with physiotherapy alone. No studies reported the effect of traction on return to work.For chronic LBP without sciatica, there was moderate-quality evidence that traction probably makes little or no difference in pain intensity when compared with sham treatment. No studies reported on the effect of traction on functional status, global improvement or return to work.Adverse effects were reported in seven of the 32 studies. These included increased pain, aggravation of neurological signs and subsequent surgery. Four studies reported that there were no adverse effects. The remaining studies did not mention adverse effects. These findings indicate that traction, either alone or in combination with other treatments, has little or no impact on pain intensity, functional status, global improvement and return to work among people with LBP. There is only limited-quality evidence from studies with small sample sizes and moderate to high risk of bias. The effects shown by these studies are small and are not clinically relevant. Implications for practice To date, the use of traction as treatment for non-specific LBP cannot be motivated by the best available evidence. These conclusions are applicable to both manual and mechanical traction. Implications for research Only new, large, high-quality studies may change the point estimate and its accuracy, but it should be noted that such change may not necessarily favour traction. Therefore, little priority should be given to new studies on the effect of traction treatment alone or as part of a package.

Simplified fatigue life analysis for traction drive contacts

NASA Technical Reports Server (NTRS)

Rohn, D. A.; Loewenthal, S. H.; Coy, J. J.

1980-01-01

A simplified fatigue life analysis for traction drive contacts of arbitrary geometry is presented. The analysis is based on the Lundberg-Palmgren theory used for rolling-element bearings. The effects of torque, element size, speed, contact ellipse ratio, and the influence of traction coefficient are shown. The analysis shows that within the limits of the available traction coefficient, traction contacts exhibit longest life at high speeds. Multiple, load-sharing roller arrangements have an advantageous effect on system life, torque capacity, power-to-weight ratio and size.

Measurements and calculations of transport AC loss in second generation high temperature superconducting pancake coils

NASA Astrophysics Data System (ADS)

Yuan, Weijia; Coombs, T. A.; Kim, Jae-Ho; Han Kim, Chul; Kvitkovic, Jozef; Pamidi, Sastry

2011-12-01

Theoretical and experimental AC loss data on a superconducting pancake coil wound using second generation (2 G) conductors are presented. An anisotropic critical state model is used to calculate critical current and the AC losses of a superconducting pancake coil. In the coil there are two regions, the critical state region and the subcritical region. The model assumes that in the subcritical region the flux lines are parallel to the tape wide face. AC losses of the superconducting pancake coil are calculated using this model. Both calorimetric and electrical techniques were used to measure AC losses in the coil. The calorimetric method is based on measuring the boil-off rate of liquid nitrogen. The electric method used a compensation circuit to eliminate the inductive component to measure the loss voltage of the coil. The experimental results are consistent with the theoretical calculations thus validating the anisotropic critical state model for loss estimations in the superconducting pancake coil.

A Ser/Thr protein kinase phosphorylates MA-ACS1 (Musa acuminata 1-aminocyclopropane-1-carboxylic acid synthase 1) during banana fruit ripening.

PubMed

Choudhury, Swarup Roy; Roy, Sujit; Sengupta, Dibyendu N

2012-08-01

1-Aminocyclopropane-1-carboxylic acid synthase (ACS) catalyzes the rate-limiting step in ethylene biosynthesis during ripening. ACS isozymes are regulated both transcriptionally and post-translationally. However, in banana, an important climacteric fruit, little is known about post-translational regulation of ACS. Here, we report the post-translational modification of MA-ACS1 (Musa acuminata ACS1), a ripening inducible isozyme in the ACS family, which plays a key role in ethylene biosynthesis during banana fruit ripening. Immunoprecipitation analyses of phospholabeled protein extracts from banana fruit using affinity-purified anti-MA-ACS1 antibody have revealed phosphorylation of MA-ACS1, particularly in ripe fruit tissue. We have identified the induction of a 41-kDa protein kinase activity in pulp at the onset of ripening. The 41-kDa protein kinase has been identified as a putative protein kinase by MALDI-TOF/MS analysis. Biochemical analyses using partially purified protein kinase fraction from banana fruit have identified the protein kinase as a Ser/Thr family of protein kinase and its possible involvement in MA-ACS1 phosphorylation during ripening. In vitro phosphorylation analyses using synthetic peptides and site-directed mutagenized recombinant MA-ACS1 have revealed that serine 476 and 479 residues at the C-terminal region of MA-ACS1 are phosphorylated. Overall, this study provides important novel evidence for in vivo phosphorylation of MA-ACS1 at the molecular level as a possible mechanism of post-translational regulation of this key regulatory protein in ethylene signaling pathway in banana fruit during ripening.

Microfabricated tissues for investigating traction forces involved in cell migration and tissue morphogenesis

PubMed Central

Nerger, Bryan A.; Siedlik, Michael J.; Nelson, Celeste M.

2016-01-01

Cell-generated forces drive an array of biological processes ranging from wound healing to tumor metastasis. Whereas experimental techniques such as traction force microscopy are capable of quantifying traction forces in multidimensional systems, the physical mechanisms by which these forces induce changes in tissue form remain to be elucidated. Understanding these mechanisms will ultimately require techniques that are capable of quantifying traction forces with high precision and accuracy in vivo or in systems that recapitulate in vivo conditions, such as microfabricated tissues and engineered substrata. To that end, here we review the fundamentals of traction forces, their quantification, and the use of microfabricated tissues designed to study these forces during cell migration and tissue morphogenesis. We emphasize the differences between traction forces in two- and three-dimensional systems, and highlight recently developed techniques for quantifying traction forces. PMID:28008471

Toward single cell traction microscopy within 3D collagen matrices

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

Hall, Matthew S.; Long, Rong; Feng, Xinzeng

Mechanical interaction between the cell and its extracellular matrix (ECM) regulates cellular behaviors, including proliferation, differentiation, adhesion, and migration. Cells require the three-dimensional (3D) architectural support of the ECM to perform physiologically realistic functions. However, current understanding of cell–ECM and cell–cell mechanical interactions is largely derived from 2D cell traction force microscopy, in which cells are cultured on a flat substrate. 3D cell traction microscopy is emerging for mapping traction fields of single animal cells embedded in either synthetic or natively derived fibrous gels. We discuss here the development of 3D cell traction microscopy, its current limitations, and perspectives onmore » the future of this technology. Emphasis is placed on strategies for applying 3D cell traction microscopy to individual tumor cell migration within collagen gels. - Highlights: • Review of the current state of the art in 3D cell traction force microscopy. • Bulk and micro-characterization of remodelable fibrous collagen gels. • Strategies for performing 3D cell traction microscopy within collagen gels.« less

Open Abdomen Therapy with Vacuum and Mesh Mediated Fascial Traction After Aortic Repair: an International Multicentre Study.

PubMed

Acosta, Stefan; Seternes, Arne; Venermo, Maarit; Vikatmaa, Leena; Sörelius, Karl; Wanhainen, Anders; Svensson, Mats; Djavani, Khatereh; Björck, Martin

2017-12-01

Open abdomen therapy may be necessary to prevent or treat abdominal compartment syndrome (ACS). The aim of the study was to analyse the primary delayed fascial closure (PDFC) rate and complications after open abdomen therapy with vacuum and mesh mediated fascial traction (VACM) after aortic repair and to compare outcomes between those treated with open abdomen after primary versus secondary operation. This was a retrospective cohort, multicentre study in Sweden, Finland, and Norway, including consecutive patients treated with open abdomen and VACM after aortic repair at six vascular centres in 2006-2015. The primary endpoint was PDFC rate. Among 191 patients, 155 were men. The median age was 71 years (IQR 66-76). Ruptured abdominal aortic aneurysm (RAAA) occurred in 69.1%. Endovascular/hybrid and open repairs were performed in 49 and 142 patients, respectively. The indications for open abdomen were inability to close the abdomen (62%) at primary operation and ACS (80%) at secondary operation. Duration of open abdomen was 11 days (IQR 7-16) in 157 patients alive at open abdomen termination. The PDFC rate was 91.8%. Open abdomen initiated at primary (N=103), compared with secondary operation (N=88), was associated with less severe initial open abdomen status (p=.006), less intestinal ischaemia (p=.002), shorter duration of open abdomen (p=.007), and less renal replacement therapy (RRT, p<.001). In hospital mortality was 39.3%, and after entero-atmospheric fistula (N=9) was 88.9%. Seven developed graft infection within 6 months, 1 year mortality was 28.6%. Intestinal ischaemia (OR 3.71, 95% CI 1.55-8.91), RRT (OR 3.62, 95% CI 1.72-7.65), and age (OR 1.12, 95% CI 1.06-1.12), were independent factors associated with in hospital mortality, but not open abdomen initiated at primary versus secondary operation. VACM was associated with a high PDFC rate after prolonged open abdomen therapy following aortic repair. Patient outcomes seemed better when open abdomen was initiated at primary, compared with secondary operation but a selection effect is possible. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Computed tomography arthrography with traction in the human hip for three-dimensional reconstruction of cartilage and the acetabular labrum

PubMed Central

Henak, C.R.; Abraham, C.L.; Peters, C.L.; Sanders, R.K.; Weiss, J.A.; Anderson, A.E.

2014-01-01

AIM To develop and demonstrate the efficacy of a computed tomography arthrography (CTA) protocol for the hip that enables accurate three-dimensional reconstructions of cartilage and excellent visualization of the acetabular labrum. MATERIALS AND METHODS Ninety-three subjects were imaged (104 scans); 68 subjects with abnormal anatomy, 11 patients after periacetabular osteotomy surgery, and 25 subjects with normal anatomy. Fifteen to 25 ml of contrast agent diluted with lidocaine was injected using a lateral oblique approach. A Hare traction splint applied traction during CT. The association between traction force and intra-articular joint space was assessed qualitatively under fluoroscopy. Cartilage geometry was reconstructed from the CTA images for 30 subjects; the maximum joint space under traction was measured. RESULTS Using the Hare traction splint, the intra-articular space and boundaries of cartilage could be clearly delineated throughout the joint; the acetabular labrum was also visible. Dysplastic hips required less traction (~5 kg) than normal and retroverted hips required (>10 kg) to separate the cartilage. An increase in traction force produced a corresponding widening of the intra-articular joint space. Under traction, the maximum width of the intra-articular joint space during CT ranged from 0.98–6.7 mm (2.46 ± 1.16 mm). CONCLUSIONS When applied to subjects with normal and abnormal hip anatomy, the CTA protocol presented yields clear delineation of the cartilage and the acetabular labrum. Use of a Hare traction splint provides a simple, cost-effective method to widen the intra-articular joint space during CT, and provides flexibility to vary the traction as required. PMID:25070373

Electrical power generating system

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1983-01-01

A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

Giant magneto-impedance and magneto-inductive effects in amorphous alloys

NASA Astrophysics Data System (ADS)

Panina, L. V.; Mohri, K.; Bushida, K.; Noda, M.

1994-11-01

Recent experiments have discovered giant and sensitive magneto-impedance and magneto-inductive effects in FeCoSiB amorphous wires. These effects include a sensitive change in an ac wire voltage with the application of a small dc longitudinal magnetic field. At low frequencies (1-10 kHz) the inductive voltage drops by 50% for a field of 2 Oe (25%/Oe) reflecting a strong field dependence of the circumferential permeability. At higher frequencies (0.1-10 MHz) when the skin effect is essential, the amplitude of the total wire voltage decreases by 40%-60% for fields of 3-10 Oe (about 10%/Oe). These effects exhibit no hysteresis for the variation of an applied field and can be obtained even in wires of 1 mm length and a few micrometer diameter. These characteristics are very useful to constitute a highly sensitive microsensor head to detect local fields of the order of 10(exp -5) Oe. In this paper, we review recently obtained experimental results on magneto-inductive and magneto-impedance effects and present a detailed discussion for their mechanism, developing a general approach in terms of ac complex impedance in a magnetic conductor. In the case of a strong skin effect the total wire impedance depends on the circumferential permeability through the penetration depth, resulting in the giant magneto-impedance effect.

Electromagnetic connector

NASA Technical Reports Server (NTRS)

Gardner, W. C.

1973-01-01

Connector pair consists of two iron cores brought together a short distance from each other. Each core is wound with insulated wire. Ac signal is connected through the pair across the gap by magnetic induction. Device can be used underwater or in flammable atmosphere.

Advances in traction drive technology

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Anderson, N. E.; Rohn, D. A.

1983-01-01

Traction drives are traced from early uses as main transmissions in automobiles at the turn of the century to modern, high-powered traction drives capable of transmitting hundreds of horsepower. Recent advances in technology are described which enable today's traction drive to be a serious candidate for off-highway vehicles and helicopter applications. Improvements in materials, traction fluids, design techniques, power loss and life prediction methods will be highlighted. Performance characteristics of the Nasvytis fixed-ratio drive are given. Promising future drive applications, such as helicopter main transmissions and servo-control positioning mechanisms are also addressed.

Spin analysis of concentrated traction contacts

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.

1983-01-01

Spin, the result of a mismatch in contact radii on either side of the point of rolling, has a detrimental effect on traction contact performance. It occurs in concentrated contacts having conical or contoured rolling elements, such as those in traction drives or angular contact bearings, and is responsible for an increase in contact heating and power loss. The kinematics of spin producing contact geometries and the subsequent effect on traction and power loss are investigated. The influence of lubricant traction characteristics and contact geometries that minimize spin are also addressed.

Surface temperatures and glassy state investigations in tribology, part 5

NASA Technical Reports Server (NTRS)

Bair, S.; Winer, W. O.

1982-01-01

Preliminary measurements of high shear rate viscosity at near atmospheric but variable pressure suggest the importance of low normal stress and cavitation or fluid fracture in the type of stress field existing in elastohydrodynam ic inlets and classical hydrodynamic configurations. An experimental basis is given for three regimes of traction in concentrated contacts: a thin film regime characterized by high traction and determined by lambda ratio, a thick film regime characterized by low traction and determined by the speed parameter, and the elastohydrodynamic regime for which traction is controlled by limiting shear stress. Traction measurements were performed with various liquids, two solid lubricants, and a grease. Film thickness and traction measurements of polymer blends and base oils are compared.

Human CRL4DDB2 ubiquitin ligase preferentially regulates post-repair chromatin restoration of H3K56Ac through recruitment of histone chaperon CAF-1

PubMed Central

Zhu, Qianzheng; Wei, Shengcai; Sharma, Nidhi; Wani, Gulzar; He, Jinshan; Wani, Altaf A.

2017-01-01

Acetylated histone H3 lysine 56 (H3K56Ac) diminishes in response to DNA damage but is restored following DNA repair. Here, we report that CRL4DDB2 ubiquitin ligase preferentially regulates post-repair chromatin restoration of H3K56Ac through recruitment of histone chaperon CAF-1. We show that H3K56Ac accumulates at DNA damage sites. The restoration of H3K56Ac but not H3K27Ac, H3K18Ac and H3K14Ac depends on CAF-1 function, whereas all these acetylations are mediated by CBP/p300. The CRL4DDB2 components, DDB1, DDB2 and CUL4A, are also required for maintaining the H3K56Ac and H3K9Ac level in chromatin, and for restoring H3K56Ac following induction of DNA photolesions and strand breaks. Depletion of CUL4A decreases the recruitment of CAF-1 p60 and p150 to ultraviolet radiation- and phleomycin-induced DNA damage. Neddylation inhibition renders CRL4DDB2 inactive, decreases H3K56Ac level, diminishes CAF-1 recruitment and prevents H3K56Ac restoration. Mutation in the PIP box of DDB2 compromises its capability to elevate the H3K56Ac level but does not affect XPC ubiquitination. These results demonstrated a function of CRL4DDB2 in differential regulation of histone acetylation in response to DNA damage, suggesting a novel role of CRL4DDB2 in repair-driven chromatin assembly. PMID:29262658

Electromechanical systems with transient high power response operating from a resonant ac link

NASA Technical Reports Server (NTRS)

Burrows, Linda M.; Hansen, Irving G.

1992-01-01

The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant ac link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control all four operating quadrants. Incorporating the ac link allows the converter in these systems to switch at the zero crossing of every half cycle of the ac waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed under contract to NASA.

Three 1-Aminocyclopropane-1-Carboxylate Synthase Genes Regulated by Primary and Secondary Pollination Signals in Orchid Flowers1

PubMed Central

Bui, Anhthu Q.; Neill, Sharman D. O'

1998-01-01

The temporal and spatial expression patterns of three 1-aminocyclopropane-1-carboxylate (ACC) synthase genes were investigated in pollinated orchid (Phalaenopsis spp.) flowers. Pollination signals initiate a cascade of development events in multiple floral organs, including the induction of ethylene biosynthesis, which coordinates several postpollination developmental responses. The initiation and propagation of ethylene biosynthesis is regulated by the coordinated expression of three distinct ACC synthase genes in orchid flowers. One ACC synthase gene (Phal-ACS1) is regulated by ethylene and participates in amplification and interorgan transmission of the pollination signal, as we have previously described in a related orchid genus. Two additional ACC synthase genes (Phal-ACS2 and Phal-ACS3) are expressed primarily in the stigma and ovary of pollinated orchid flowers. Phal-ACS2 mRNA accumulated in the stigma within 1 h after pollination, whereas Phal-ACS1 mRNA was not detected until 6 h after pollination. Similar to the expression of Phal-ACS2, the Phal-ACS3 gene was expressed within 2 h after pollination in the ovary. Exogenous application of auxin, but not ACC, mimicked pollination by stimulating a rapid increase in ACC synthase activity in the stigma and ovary and inducing Phal-ACS2 and Phal-ACS3 mRNA accumulation in the stigma and ovary, respectively. These results provide the basis for an expanded model of interorgan regulation of three ACC synthase genes that respond to both primary (Phal-ACS2 and Phal-ACS3) and secondary (Phal-ACS1) pollination signals. PMID:9449850

The effect of cavernous nerve traction on erectile function in rats

PubMed Central

Chen, Liping; Wang, Tao; Wang, Shaogang; Liu, Jihong

2017-01-01

We performed this study to evaluate the effect of cavernous nerve (CN) traction on erectile function in rats. Thirty-two 8- week-old Sprague–Dawley rats were divided into four groups: control, 1-minute CN traction, 2-minute CN traction, and 2-minute CN crush. CN traction was performed using a glass hook with a tensile force of 0.2 Newton. One month later, the mean arterial pressure (MAP) and intracavernosal pressure (ICP) in response to CN stimulation were measured to assess erectile function. The penis and major pelvic ganglion (MPG) were harvested to explore the expression of neuronal nitric oxide synthase (nNOS) and neurofilament, fibrosis and apoptosis. The ICP/MAP ratio was reduced in the 2-minute CN traction group compared with the control group (P < 0.05). The ICP/MAP ratio in the CN crush group was lower than in the other three groups (P < 0.05, for each). Expression of nNOS in both MPG and dorsal penile nerve was lower in the CN traction group than in the control group, but was higher than in the CN crush group (P < 0.05). Nerve fiber number in the dorsal penile nerve was reduced by 2-minute CN traction (P < 0.05). The ratios of collagen to smooth muscle content and the apoptosis were both increased the in 2-minute CN traction group compared with the control group (P < 0.05). The findings indicate that CN traction is an effective CN injury model and the injury it caused is relatively mild compared with the CN crush model. PMID:28982169

Discharging a DC bus capacitor of an electrical converter system

DOEpatents

Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

2014-10-14

A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

Intradiscal Pressure Changes during Manual Cervical Distraction: A Cadaveric Study

PubMed Central

Gudavalli, M. R.; Potluri, T.; Carandang, G.; Havey, R. M.; Voronov, L. I.; Cox, J. M.; Rowell, R. M.; Kruse, R. A.; Joachim, G. C.; Patwardhan, A. G.; Henderson, C. N. R.; Goertz, C.

2013-01-01

The objective of this study was to measure intradiscal pressure (IDP) changes in the lower cervical spine during a manual cervical distraction (MCD) procedure. Incisions were made anteriorly, and pressure transducers were inserted into each nucleus at lower cervical discs. Four skilled doctors of chiropractic (DCs) performed MCD procedure on nine specimens in prone position with contacts at C5 or at C6 vertebrae with the headpiece in different positions. IDP changes, traction forces, and manually applied posterior-to-anterior forces were analyzed using descriptive statistics. IDP decreases were observed during MCD procedure at all lower cervical levels C4-C5, C5-C6, and C6-C7. The mean IDP decreases were as high as 168.7 KPa. Mean traction forces were as high as 119.2 N. Posterior-to-anterior forces applied during manual traction were as high as 82.6 N. Intraclinician reliability for IDP decrease was high for all four DCs. While two DCs had high intraclinician reliability for applied traction force, the other two DCs demonstrated only moderate reliability. IDP decreases were greatest during moving flexion and traction. They were progressevely less pronouced with neutral traction, fixed flexion and traction, and generalized traction. PMID:24023587

Traction forces during collective cell motion.

PubMed

Gov, N S

2009-08-01

Collective motion of cell cultures is a process of great interest, as it occurs during morphogenesis, wound healing, and tumor metastasis. During these processes cell cultures move due to the traction forces induced by the individual cells on the surrounding matrix. A recent study [Trepat, et al. (2009). Nat. Phys. 5, 426-430] measured for the first time the traction forces driving collective cell migration and found that they arise throughout the cell culture. The leading 5-10 rows of cell do play a major role in directing the motion of the rest of the culture by having a distinct outwards traction. Fluctuations in the traction forces are an order of magnitude larger than the resultant directional traction at the culture edge and, furthermore, have an exponential distribution. Such exponential distributions are observed for the sizes of adhesion domains within cells, the traction forces produced by single cells, and even in nonbiological nonequilibrium systems, such as sheared granular materials. We discuss these observations and their implications for our understanding of cellular flows within a continuous culture.

Application of low-order potential solutions to higher-order vertical traction boundary problems in an elastic half-space

PubMed Central

Taylor, Adam G.

2018-01-01

New solutions of potential functions for the bilinear vertical traction boundary condition are derived and presented. The discretization and interpolation of higher-order tractions and the superposition of the bilinear solutions provide a method of forming approximate and continuous solutions for the equilibrium state of a homogeneous and isotropic elastic half-space subjected to arbitrary normal surface tractions. Past experimental measurements of contact pressure distributions in granular media are reviewed in conjunction with the application of the proposed solution method to analysis of elastic settlement in shallow foundations. A numerical example is presented for an empirical ‘saddle-shaped’ traction distribution at the contact interface between a rigid square footing and a supporting soil medium. Non-dimensional soil resistance is computed as the reciprocal of normalized surface displacements under this empirical traction boundary condition, and the resulting internal stresses are compared to classical solutions to uniform traction boundary conditions. PMID:29892456

Traction injury of the recurrent laryngeal nerve: Results of continuous intraoperative neuromonitoring in a swine model.

PubMed

Lee, Hye Yoon; Cho, Young Geon; You, Ji Young; Choi, Byoung Ho; Kim, Joon Yub; Wu, Che-Wei; Chiang, Feng-Yu; Kim, Hoon Yub

2016-04-01

Recurrent laryngeal nerve (RLN) palsy is the most serious complication after thyroidectomy. However, little is known about the degree of traction injury that causes loss of signal. The purpose of this study was to evaluate traction injuries in the swine RLN using continuous intraoperative neuromonitoring (IONM) and determine the traction power that results in loss of signal. Thirteen swine underwent traction injury to the RLNs with continuous IONM, and stress-strain curves were determined for 8 nerves using the universal material testing machine in an ex vivo model. Traction injury at a mean power of 2.83 MPa caused loss of signal. The mean physiologic limit strain and tensile strength of the swine RLNs were found to be 15.0% and 4.9 MPa, respectively. Histological analysis showed no abnormal structural findings. Traction injury of swine RLNs causes loss of signal at a power of 2.83 MPa. However, all injured nerves recovered within 7 days with no observed structural damage. © 2015 Wiley Periodicals, Inc.

Scoliosis elasticity assessed by manual traction: 49 juvenile and adolescent idiopathic cases.

PubMed

Soucacos, P K; Soucacos, P N; Beris, A E

1996-04-01

We assessed preoperative curve elasticity in 49 consecutive patients with juvenile or adolescent idiopathic scoliosis who were operated on with Harrington distraction rods. Preoperatively, the curve was determined from posteroanterior radiographs taken in the standing position and in the supine position, with traction. In the latter, the radiographs were taken at the moment of maximal traction when one technician applied traction to the ankles and another to the wrists. The scoliotic curve in the 10 patients with juvenile scoliosis averaged 59 degrees and 32 degrees in the standing and supine positions with traction, respectively. Immediately postoperatively, the curve averaged 19 degrees. 39 patients with adolescent scoliosis had a scoliotic curve which averaged 58 degrees in the standing position and 32 degrees in the supine position with traction. The mean postoperative measurement was 21 degrees. These findings suggest that manual traction is a simple and reliable means of predicting the minimal correction of the scoliotic curve to be expected, using Harrington distraction rods.

Electronically commutated motors for vehicle applications

NASA Astrophysics Data System (ADS)

Echolds, E. F.

1980-02-01

Two permanent magnet electronically commutated motors for electric vehicle traction are discussed. One, based on existing technology, produces 23 kW (peak) at 26,000 rpm, and 11 kW continuous at 18,000 rpm. The motor has a conventional design: a four-pole permanent magnet rotor and a three-phase stator similar to those used on ordinary induction motors. The other, advanced technology motor, is rated at 27 kW (peak) at 14,000 rpm, and 11 kW continuous at 10,500 rpm. The machine employs a permanent magnet rotor and a novel ironless stator design in an axial air gap, homopolar configuration. Comparison of the new motors with conventional brush type machines indicates potential for substantial cost savings.

Applications of 211At and 223Ra in Targeted Alpha-Particle Radiotherapy

PubMed Central

Vaidyanathan, Ganesan; Zalutsky, Michael R.

2012-01-01

Targeted radiotherapy using agents tagged with α-emitting radionuclides is gaining traction with several clinical trials already undertaken or ongoing, and others in the advanced planning stage. The most commonly used α-emitting radionuclides are 213Bi, 211At, 223Ra and 225Ac. While each one of these has pros and cons, it can be argued that 211At probably is the most versatile based on its half life, decay scheme and chemistry. On the other hand, for targeting bone metastases, 223Ra is the ideal radionuclide because simple cationic radium can be used for this purpose. In this review, we will discuss the recent developments taken place in the application of 211At-labeled radiopharmaceuticals and give an overview of the current status of 223Ra for targeted α-particle radiotherapy. PMID:22202151

Steady-state analysis of a faulted three-phase four-wire system supplying induction motors with neutrals connected and other single-phase line-to-neutral loads

NASA Technical Reports Server (NTRS)

Wood, M. E.

1980-01-01

Four wire Wye connected ac power systems exhibit peculiar steady state fault characteristics when the fourth wire of three phase induction motors is connected. The loss of one phase of power source due to a series or shunt fault results in currents higher than anticipated on the remaining two phases. A theoretical approach to compute the fault currents and voltages is developed. A FORTRAN program is included in the appendix.

Geophysical Interpretation of Induction Arrows Observed at Jeju Island, Korea

NASA Astrophysics Data System (ADS)

Yang, J.; Choi, H.

2015-12-01

Jeju Island, a volcanic island located on the continental margin in the southern end of the Korean Peninsula, has been paid a special attention to geological and geophysical society for a long time due to its tectonic importance associated with the volcanism of the island. In this study, we try to interpret induction arrows observed at the island that have been estimated from broad-band magnetotelluric (MT) data and existing magnetovariational data, which are sensitive to lateral conductivity distribution of the Earth. Overall pattern of observed induction arrows is clearly frequency-dependent: perpendicular to nearby coastline of the observation site for higher frequencies than 0.1 Hz but rotating toward south or southeastern direction for lower frequency than 0.01 Hz. Furthermore, induction arrows at frequencies lower than 0.001 Hz, which derived from the existing magnetovariational data, point to the south or the southeast as well. In order to examine whether observed induction arrows can be explained by only surrounding seas, 3-D MT modeling considering seas surrounding the island is carried out. The results demonstrate that induction arrows at higher frequencies than 0.01 Hz can be explained well by the surrounding seas but for lower frequencies than 0.01 Hz there are significant discrepancies between observed and calculated arrows. This strongly implies the existence of deep-seated conductor located beneath the farther south of the island, namely, the East China Sea. The existence of this deep-seated conductor can be supported by other previous geophysical studies, which is likely to be caused by mantle upwelling derived from shear traction of horizontal mantle flow in tensional back arc of Kyushu Island, Japan.

Molecular Cloning and Characterization of Four Genes Encoding Ethylene Receptors Associated with Pineapple (Ananas comosus L.) Flowering.

PubMed

Li, Yun-He; Wu, Qing-Song; Huang, Xia; Liu, Sheng-Hui; Zhang, Hong-Na; Zhang, Zhi; Sun, Guang-Ming

2016-01-01

Exogenous ethylene, or ethephon, has been widely used to induce pineapple flowering, but the molecular mechanism behind ethephon induction is still unclear. In this study, we cloned four genes encoding ethylene receptors (designated AcERS1a, AcERS1b, AcETR2a, and AcETR2b). The 5' flanking sequences of these four genes were also cloned by self-formed adaptor PCR and SiteFinding-PCR, and a group of putative cis-acting elements was identified. Phylogenetic tree analysis indicated that AcERS1a, AcERS1b, AcETR2a, and AcETR2b belonged to the plant ERS1s and ETR2/EIN4-like groups. Quantitative real-time PCR showed that AcETR2a and AcETR2b (subfamily 2) were more sensitive to ethylene treatment compared with AcERS1a and AcERS1b (subfamily 1). The relative expression of AcERS1b, AcETR2a, and AcETR2b was significantly increased during the earlier period of pineapple inflorescence formation, especially at 1-9 days after ethylene treatment (DAET), whereas AcERS1a expression changed less than these three genes. In situ hybridization results showed that bract primordia (BP) and flower primordia (FP) appeared at 9 and 21 DAET, respectively, and flowers were formed at 37 DAET. AcERS1a, AcERS1b, AcETR2a, and AcETR2b were mainly expressed in the shoot apex at 1-4 DAET; thereafter, with the appearance of BP and FP, higher expression of these genes was found in these new structures. Finally, at 37 DAET, the expression of these genes was mainly focused in the flower but was also low in other structures. These findings indicate that these four ethylene receptor genes, especially AcERS1b, AcETR2a, and AcETR2b, play important roles during pineapple flowering induced by exogenous ethephon.

Molecular Cloning and Characterization of Four Genes Encoding Ethylene Receptors Associated with Pineapple (Ananas comosus L.) Flowering

PubMed Central

Li, Yun-He; Wu, Qing-Song; Huang, Xia; Liu, Sheng-Hui; Zhang, Hong-Na; Zhang, Zhi; Sun, Guang-Ming

2016-01-01

Exogenous ethylene, or ethephon, has been widely used to induce pineapple flowering, but the molecular mechanism behind ethephon induction is still unclear. In this study, we cloned four genes encoding ethylene receptors (designated AcERS1a, AcERS1b, AcETR2a, and AcETR2b). The 5′ flanking sequences of these four genes were also cloned by self-formed adaptor PCR and SiteFinding-PCR, and a group of putative cis-acting elements was identified. Phylogenetic tree analysis indicated that AcERS1a, AcERS1b, AcETR2a, and AcETR2b belonged to the plant ERS1s and ETR2/EIN4-like groups. Quantitative real-time PCR showed that AcETR2a and AcETR2b (subfamily 2) were more sensitive to ethylene treatment compared with AcERS1a and AcERS1b (subfamily 1). The relative expression of AcERS1b, AcETR2a, and AcETR2b was significantly increased during the earlier period of pineapple inflorescence formation, especially at 1–9 days after ethylene treatment (DAET), whereas AcERS1a expression changed less than these three genes. In situ hybridization results showed that bract primordia (BP) and flower primordia (FP) appeared at 9 and 21 DAET, respectively, and flowers were formed at 37 DAET. AcERS1a, AcERS1b, AcETR2a, and AcETR2b were mainly expressed in the shoot apex at 1–4 DAET; thereafter, with the appearance of BP and FP, higher expression of these genes was found in these new structures. Finally, at 37 DAET, the expression of these genes was mainly focused in the flower but was also low in other structures. These findings indicate that these four ethylene receptor genes, especially AcERS1b, AcETR2a, and AcETR2b, play important roles during pineapple flowering induced by exogenous ethephon. PMID:27252725

Overhead Bryant's Traction Does Not Improve the Success of Closed Reduction or Limit AVN in Developmental Dysplasia of the Hip.

PubMed

Sucato, Daniel J; De La Rocha, Adriana; Lau, Karlee; Ramo, Brandon A

2017-03-01

Preoperative Bryant's overhead traction before closed reduction (CR) in developmental dysplasia of the hip (DDH) remains controversial and its success in increasing CR rates and reducing avascular necrosis (AVN) rates has not been specifically reported in a large cohort. IRB-approved retrospective study of patients (below 3 y)who were treated with attempted CR for idiopathic DDH from 1980 to 2009. Successful CR was defined as a hip that remained reduced and did not require repeat CR or open reduction. Patients were grouped by age, hip instability [Ortolani positive (reducible) vs. fixed dislocation], and Tonnis classification and rates of successful CR were compared between groups with P<0.05. A total of 342 hips were included with a mean age of 0.9 years (0.2 to 2.8 y) and a mean follow-up of 10.4 years (2.0 to 27.7 y). There were 269 hips with fixed dislocations and 73 Ortolani-positive hips. Traction was used in 276 hips. There was no difference in traction utilization in the 3 age groups (below 1, below 1.5, and below 2 y) for either Ortolani-positive hips (P=0.947) or fixed dislocations (P=0.943). There was no difference in achieving a successful CR comparing traction (60.9%) and no-traction groups (60.6%) (P=1.00). For Ortolani-positive hips, traction did not improve the incidence of a successful CR for any age group: below 1 year: P=0.19; below 1.5 years: P=0.23; and below 2 years: P=0.25. Similarly, fixed dislocation patients had no benefit from traction: below 1 year: P=0.76; below 1.5 years: P=0.82; and below 2 years: P=0.85. Tonnis classification did predict success of CR but had no influence on traction success. There was no difference in the rate of AVN between the traction (18%) and no-traction (8%) groups for all patients (P=0.15). In this retrospective series, preoperative Bryant's traction does not improve the rate of a successful CR for patients with DDH and has no protective effect on the development of AVN of the femoral head. These results suggest that Bryant's overhead traction may not be warranted for patients below 3 years of age with DDH. Level III.

Traction force microscopy in rapidly moving cells reveals separate roles for ROCK and MLCK in the mechanics of retraction.

PubMed

Morin, Timothy R; Ghassem-Zadeh, Sean A; Lee, Juliet

2014-08-15

Retraction is a major rate-limiting step in cell motility, particularly in slow moving cell types that form large stable adhesions. Myosin II dependent contractile forces are thought to facilitate detachment by physically pulling up the rear edge. However, retraction can occur in the absence of myosin II activity in cell types that form small labile adhesions. To investigate the role of contractile force generation in retraction, we performed traction force microscopy during the movement of fish epithelial keratocytes. By correlating changes in local traction stress at the rear with the area retracted, we identified four distinct modes of retraction. "Recoil" retractions are preceded by a rise in local traction stress, while rear edge is temporarily stuck, followed by a sharp drop in traction stress upon detachment. This retraction type was most common in cells generating high average traction stress. In "pull" type retractions local traction stress and area retracted increase concomitantly. This was the predominant type of retraction in keratocytes and was observed mostly in cells generating low average traction stress. "Continuous" type retractions occur without any detectable change in traction stress, and are seen in cells generating low average traction stress. In contrast, to many other cell types, "release" type retractions occur in keratocytes following a decrease in local traction stress. Our identification of distinct modes of retraction suggests that contractile forces may play different roles in detachment that are related to rear adhesion strength. To determine how the regulation of contractility via MLCK or Rho kinase contributes to the mechanics of detachment, inhibitors were used to block or augment these pathways. Modulation of MLCK activity led to the most rapid change in local traction stress suggesting its importance in regulating attachment strength. Surprisingly, Rho kinase was not required for detachment, but was essential for localizing retraction to the rear. We suggest that in keratocytes MLCK and Rho kinase play distinct, complementary roles in the respective temporal and spatial control of rear detachment that is essential for maintaining rapid motility. Copyright © 2014 Elsevier Inc. All rights reserved.

A prospective study of pain reduction and knee dysfunction comparing femoral skeletal traction and splinting in adult trauma patients.

PubMed

Bumpass, David B; Ricci, William M; McAndrew, Christopher M; Gardner, Michael J

2015-02-01

To determine if distal femoral traction pins result in knee dysfunction in patients with femoral or pelvic fracture, and to determine if skeletal traction relieves pain more effectively than splinting for femoral shaft fractures. Prospective cohort trial. Level I urban trauma center. One hundred twenty adult patients with femoral shaft, acetabular, and unstable pelvic fractures. Patients with femoral shaft fractures were placed into distal femoral skeletal traction or a long-leg splint, based on an attending-specific protocol. Patients with pelvic or acetabular fractures with instability or intraarticular bone fragments were placed into skeletal traction. An initial Lysholm knee survey was administered to assess preinjury knee pain and function; the survey was repeated at 3- and 6-month follow-up visits. Also, a 10-point visual analog scale was used to document pain immediately before, during, and immediately after fracture immobilization with traction or splinting. Thirty-five patients (29%) were immobilized with a long-leg splint, and 85 (71%) were immobilized with a distal femoral traction pin. Eighty-four patients (70%) completed a 6-month follow-up. Lysholm scores decreased by a mean 9.3 points from preinjury baseline to 6 months postinjury in the entire cohort (P < 0.01); no significant differences were found between the splint and traction pin groups. During application of immobilization, visual analog scale pain scores were significantly lower in traction patients as compared with splinted patients (mean, 1.9 points less, P < 0.01). Traction pins caused no infections, neurovascular injuries, or iatrogenic fractures. Distal femoral skeletal traction does not result in detectable knee dysfunction at 6 months after insertion, and results in less pain during and after immobilization than long-leg splinting. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Closed Loop Fuzzy Logic Controlled PV Based Cascaded Boost Five-Level Inverter System

NASA Astrophysics Data System (ADS)

Revana, Guruswamy; Kota, Venkata Reddy

2018-04-01

Recent developments in intelligent control methods and power electronics have produced PV based DC to AC converters related to AC drives. Cascaded boost converter and inverter find their way in interconnecting PV and Induction Motor. This paper deals with digital simulation and implementation of closed loop controlled five-level inverter based Photo-Voltaic (PV) system. The objective of this work is to reduce the harmonics using Multi Level Inverter based system. The DC output from the PV panel is boosted using cascaded-boost-converters. The DC output of these cascaded boost converters is applied to the bridges of the cascaded inverter. The AC output voltage is obtained by the series cascading of the output voltage of the two inverters. The investigations are done with Induction motor load. Cascaded boost-converter is proposed in the present work to produce the required DC Voltage at the input of the bridge inverter. A simple FLC is applied to CBFLIIM system. The FLC is proposed to reduce the steady state error. The simulation results are compared with the hardware results. The results of the comparison are made to show the improvement in dynamic response in terms of settling time and steady state error. Design procedure and control strategy are presented in detail.

Genetic Transformation of Hordeum vulgare ssp. spontaneum for the Development of a Transposon-Based Insertional Mutagenesis System.

PubMed

Cardinal, Marie-Josée; Kaur, Rajvinder; Singh, Jaswinder

2016-10-01

Domestication and intensive selective breeding of plants has triggered erosion of genetic diversity of important stress-related alleles. Researchers highlight the potential of using wild accessions as a gene source for improvement of cereals such as barley, which has major economic and social importance worldwide. Previously, we have successfully introduced the maize Ac/Ds transposon system for gene identification in cultivated barley. The objective of current research was to investigate the response of Hordeum vulgare ssp. spontaneum wild barley accessions in tissue culture to standardize parameters for introduction of Ac/Ds transposons through genetic transformation. We investigated the response of ten wild barley genotypes for callus induction, regenerative green callus induction and regeneration of fertile plants. The activity of exogenous Ac/Ds elements was observed through a transient assay on immature wild barley embryos/callus whereby transformed embryos/calli were identified by the expression of GUS. Transient Ds expression bombardment experiments were performed on 352 pieces of callus (3-5 mm each) or immature embryos in 4 genotypes of wild barley. The transformation frequency of putative transgenic callus lines based on transient GUS expression ranged between 72 and100 % in wild barley genotypes. This is the first report of a transformation system in H. vulgare ssp. spontaneum.

Closed Loop Fuzzy Logic Controlled PV Based Cascaded Boost Five-Level Inverter System

NASA Astrophysics Data System (ADS)

Revana, Guruswamy; Kota, Venkata Reddy

2017-12-01

Recent developments in intelligent control methods and power electronics have produced PV based DC to AC converters related to AC drives. Cascaded boost converter and inverter find their way in interconnecting PV and Induction Motor. This paper deals with digital simulation and implementation of closed loop controlled five-level inverter based Photo-Voltaic (PV) system. The objective of this work is to reduce the harmonics using Multi Level Inverter based system. The DC output from the PV panel is boosted using cascaded-boost-converters. The DC output of these cascaded boost converters is applied to the bridges of the cascaded inverter. The AC output voltage is obtained by the series cascading of the output voltage of the two inverters. The investigations are done with Induction motor load. Cascaded boost-converter is proposed in the present work to produce the required DC Voltage at the input of the bridge inverter. A simple FLC is applied to CBFLIIM system. The FLC is proposed to reduce the steady state error. The simulation results are compared with the hardware results. The results of the comparison are made to show the improvement in dynamic response in terms of settling time and steady state error. Design procedure and control strategy are presented in detail.

Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

DOEpatents

Cikanek, S.R.

1994-10-25

An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

Electric vehicle regenerative antiskid braking and traction control system

DOEpatents

Cikanek, S.R.

1995-09-12

An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

Electric vehicle regenerative antiskid braking and traction control system

DOEpatents

Cikanek, Susan R.

1995-01-01

An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

DOEpatents

Cikanek, Susan R.

1994-01-01

An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

Solid lubrication design methodology

NASA Technical Reports Server (NTRS)

Aggarwal, B. B.; Yonushonis, T. M.; Bovenkerk, R. L.

1984-01-01

A single element traction rig was used to measure the traction forces at the contact of a ball against a flat disc at room temperature under combined rolling and sliding. The load and speed conditions were selected to match those anticipated for bearing applications in adiabatic diesel engines. The test program showed that the magnitude of traction forces were almost the same for all the lubricants tested; a lubricant should, therefore, be selected on the basis of its ability to prevent wear of the contact surfaces. Traction vs. slide/roll ratio curves were similar to those for liquid lubricants but the traction forces were an order of magnitude higher. The test data was used to derive equations to predict traction force as a function of contact stress and rolling speed. Qualitative design guidelines for solid lubricated concentrated contacts are proposed.

Asymmetric vitreomacular traction and symmetrical full thickness macular hole formation.

PubMed

Woon, Wai H; Greig, Denis; Savage, Mike D; Wilson, Mark C T; Grant, Colin A; Bishop, Fiona; Mokete, Bataung

2015-11-01

A Full Thickness Macular Hole (FTMH) is often associated with vitreomacular traction, and this can be asymmetric with vitreomacular traction on one side of the hole but not the other. In cross-section, the elevated retinal rim around a developed FTMH is seen as a drawbridge elevation, and this drawbridge elevation may be used as a measure of morphological change. Examination of the drawbridge elevation of the retinal rim in FTMH with asymmetric vitreomacular traction may help to clarify the role of vitreomacular traction in the development of FTMH. Cases of FTMH were identified with an initial OCT scan showing vitreomacular traction on one side of the hole only and that had a follow-up OCT scan showing progression of the hole. A tangent to the retinal surface at a distance of 700 microns from the axis of the hole was used as a marker of the drawbridge elevation of the retinal rim around the macular hole. Comparisons of the drawbridge elevation and change in drawbridge elevation between the sides with and without initial vitreomacular traction were made. There was no significant difference between the drawbridge elevation, or change in drawbridge elevation, on the side of the hole with initial vitreomacular traction compared to the side without initial traction. There is some intrinsic mechanism within the retina to link the morphological changes on the two sides of a FTMH. A bistable hypothesis of FTMH formation and closure is postulated to explain this linkage.

The Effect of Skin Traction on Preoperative Pain and Need for Analgesics in Patients With Intertrochanteric Fractures: A Randomized Clinical Trial

PubMed Central

Manafi Rasi, Alireza; Amoozadeh, Farzad; Khani, Salim; Kamrani Rad, Amin; Sazegar, Ali

2015-01-01

Background: Preoperative skin traction is applied for many patients with hip fracture. However, the efficacy of this modality in pain relief is controversial. Objectives: The aim of the current study was to investigate the effects of skin traction on pain in patients with intertrochanteric fractures. Patients and Methods: A total of 40 patients contributed in this randomized clinical trial. Patients were randomly allocated into two equal groups: the skin traction (3 kg) and control groups. The severity of pain was recorded at admission and 30 minutes, one, six, 12, and 24 hours after skin traction application utilizing a Visual Analogue Scale (VAS). In addition, the number of requests for analgesics was recorded. Finally, the mean severity of pain in each measurement and the mean number of analgesic requests were compared between the two groups. Results: The severity of pain was significantly decreased in skin traction group only at the end of the first day after traction application (2.7 ± 0.8 vs. 3.3 ± 0.9; P = 0.042), while there was no significant difference between the two groups in other pain measurements. The number of requests for analgesics was the same between the two groups. Conclusions: Although skin traction had no effect on analgesic consumption, it significantly decreased the pain at the end of the first day. The application of skin traction in patients with intertrochanteric fractures is recommended. PMID:26401491

Traction Stresses Exerted by Adherent Cells: From Angiogenesis to Metastasis

NASA Astrophysics Data System (ADS)

Reinhart-King, Cynthia

2010-03-01

Cells exert traction stresses against their substrate that mediate their ability to sense the mechanical properties of their microenvironment. These same forces mediate cell adhesion, migration and the formation of stable cell-cell contacts during tissue formation. In this talk, I will present our data on the traction stresses generated by endothelial cells and metastatic breast cancer cells focused on understanding the processes of angiogenesis and metastasis, respectively. In the context of capillary formation, our data indicate that the mechanics of the substrate play a critical role in establishing endothelial cell-cell contacts. On more compliant substrates, endothelial cell shape and traction stresses polarize and promote the formation of stable cell-cell contacts. On stiffer substrates, traction stresses are less polarized and cell connectivity is disrupted. These data indicate that the mechanical properties of the microenvironment may drive cell connectivity and the formation of stable cell-cell contacts through the reorientation of traction stresses. In our studies of metastatic cell migration, we have found that traction stresses increase with increasing metastatic potential. We investigated three lines of varying metastatic potential (MCF10A, MCF7 and MDAMB231). MDAMB231, which are the most invasive, exert the most significant forces as measured by Traction Force Microscopy. These data present the possibility that cellular traction stress generation aids in the ability of metastatic cells to migrate through the matrix-dense tumor microenvironment. Such measurements are integral to link the mechanical and chemical microenvironment with the resulting response of the cell in health and disease.

The effect of tibio-femoral traction mobilization on passive knee flexion motion impairment and pain: a case series

PubMed Central

Maher, Sara; Creighton, Doug; Kondratek, Melodie; Krauss, John; Qu, Xianggui

2010-01-01

The purpose of this case series was to explore the effects of tibio-femoral (TF) manual traction on pain and passive range of motion (PROM) in individuals with unilateral motion impairment and pain in knee flexion. Thirteen participants volunteered for the study. All participants received 6 minutes of TF traction mobilization applied at end-range passive knee flexion. PROM measurements were taken before the intervention and after 2, 4, and 6 minutes of TF joint traction. Pain was measured using a visual analog scale with the TF joint at rest, at end-range passive knee flexion, during the application of joint traction, and immediately post-treatment. There were significant differences in PROM after 2 and 4 minutes of traction, with no significance noted after 4 minutes. A significant change in knee flexion of 25.9°, which exceeded the MDC95, was found when comparing PROM measurements pre- to final intervention. While pain did not change significantly over time, pain levels did change significantly during each treatment session. Pain significantly increased when the participant’s knee was passively flexed to end range; it was reduced, although not significantly, during traction mobilization; and it significantly decreased following traction. This case series supports TF joint traction as a means of stretching shortened articular and periarticular tissues without increasing reported levels of pain during or after treatment. In addition, this is the first study documenting the temporal aspects of treatment effectiveness in motion restoration. PMID:21655421

Local traction force in the proximal leading process triggers nuclear translocation during neuronal migration.

PubMed

Umeshima, Hiroki; Nomura, Ken-Ichi; Yoshikawa, Shuhei; Hörning, Marcel; Tanaka, Motomu; Sakuma, Shinya; Arai, Fumihito; Kaneko, Makoto; Kengaku, Mineko

2018-04-05

Somal translocation in long bipolar neurons is regulated by actomyosin contractile forces, yet the precise spatiotemporal sites of force generation are unknown. Here we investigate the force dynamics generated during somal translocation using traction force microscopy. Neurons with a short leading process generated a traction force in the growth cone and counteracting forces in the leading and trailing processes. In contrast, neurons with a long leading process generated a force dipole with opposing traction forces in the proximal leading process during nuclear translocation. Transient accumulation of actin filaments was observed at the dipole center of the two opposing forces, which was abolished by inhibition of myosin II activity. A swelling in the leading process emerged and generated a traction force that pulled the nucleus when nuclear translocation was physically hampered. The traction force in the leading process swelling was uncoupled from somal translocation in neurons expressing a dominant negative mutant of the KASH protein, which disrupts the interaction between cytoskeletal components and the nuclear envelope. Our results suggest that the leading process is the site of generation of actomyosin-dependent traction force in long bipolar neurons, and that the traction force is transmitted to the nucleus via KASH proteins. Copyright © 2018 Elsevier B.V. and Japan Neuroscience Society. All rights reserved.

Spatial and temporal traction response in human airway smooth muscle cells

NASA Technical Reports Server (NTRS)

Tolic-Norrelykke, Iva Marija; Butler, James P.; Chen, Jianxin; Wang, Ning

2002-01-01

Tractions that cells exert on their substrates are essential in cell spreading, migration, and contraction. These tractions can be determined by plating the cells on a flexible gel and measuring the deformation of the gel by using fluorescent beads embedded just below the surface of the gel. In this article we describe the image correlation method (ICM) optimized for determining the displacement field of the gel under a contracting cell. For the calculation of the traction field from the displacement field we use the recently developed method of Fourier transform traction cytometry (FTTC). The ICM and FTTC methods are applied to human airway smooth muscle cells during stimulation with the contractile agonist histamine or the relaxing agonist isoproterenol. The overall intensity of the cell contraction (the median traction magnitude, the energy transferred from the cell to the gel, and the net contractile moment) increased after activation with histamine, and decreased after treatment with isoproterenol. Cells exhibited regional differences in the time course of traction during the treatment. Both temporal evolution and magnitude of traction increase induced by histamine varied markedly among different cell protrusions, whereas the nuclear region showed the smallest response. These results suggest that intracellular mediators of cell adhesion and contraction respond to contractile stimuli with different rates and intensities in different regions of the cell.

Naegele Forceps Delivery and Association between Morbidity and the Number of Forceps Traction Applications: A Retrospective Study.

PubMed

Matsumoto, Naoki; Takenaka, Toshifumi; Ikeda, Nobuyuki; Yazaki, Satoshi; Sato, Yuichi

2015-01-01

To present the method of Naegele forceps delivery clinically practiced by the lead author, its success rate, and morbidity and to evaluate the relationship between morbidity and the number of forceps traction applications. Naegele forceps delivery was performed when the fetal head reached station +2 cm, the forceps were applied in the maternal pelvic application, and traction was slowly and gently performed. In the past two years, Naegele forceps delivery was attempted by the lead author in 87 cases, which were retrospectively reviewed. The numbers of traction applications were one in 64.7% of cases, two in 24.7%, and three or more in 10.7%. The success rate was 100%. No severe morbidity was observed in mothers or neonates. Neonatal facial injury occurred most commonly in cases with fetal head malrotation, elevated numbers of traction applications, and maternal complications. Umbilical artery acidemia most commonly occurred in cases with nonreassuring fetal status. The significant crude odds ratio for three or more traction applications was 20 in cases with malrotation. Naegele forceps delivery has a high success rate, but multiple traction applications will sometimes be required, particularly in cases with malrotation. Malrotation and elevated numbers of traction applications may lead to neonatal head damage.

The efficacy of Labetalol versus Nitroglycerin for induction of controlled hypotension during sinus endoscopic surgery. A prospective, double-blind and randomized study.

PubMed

El-Shmaa, Nagat S; Ezz, Hoda Alsaid Ahmed; Younes, Ahmed

2017-06-01

To assess the efficacy of labetalol versus nitroglycerin for induction of controlled hypotension during sinus endoscopic surgery. A prospective, double-blind and randomized study. Carried out in operating room in university hospital. 60 patients of both sexes, American Society of Anesthesiologists (ASA) physical status I and II, age range from 20 to 60years; scheduled for elective sinus endoscopic surgery under general anesthesia (GA). Patients were divided into two groups (30 each). NTG group received nitroglycerin infusion at a dose of 2-5μg/kg/min, LAB group received labetalol infusion at a dose of 0.5-2mg/min. Surgical condition was assessed by surgeon using average category scale (ACS) of 0-5, a value of 2-3 being ideal. In both groups mean arterial blood pressure (MAP) was gradually reduced till the ideal ACS for assessment of surgical condition, the target of ACS was 2-3 or lower. Both studied drugs achieved desired hypotension and improved visualization of surgical field by decreasing bleeding in the surgical site, but ideal surgical conditions were created at mild hypotension (MAP 70-75) in LAB group while same conditions were created at MAP of 65-69mmHg in NTG group. Mean heart rate (HR) was significantly higher in NTG group as compared to LAB group. Blood loss decreased significantly in LAB group. Both labetalol and NTG are effective and safe drugs for induction of controlled hypotension during sinus endoscopic surgery. While, labetalol was better as it offered optimum operative condition with mild decrease in blood pressure, decreased surgical bleeding and less tachycardia during the surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Simplified and advanced modelling of traction control systems of heavy-haul locomotives

NASA Astrophysics Data System (ADS)

Spiryagin, Maksym; Wolfs, Peter; Szanto, Frank; Cole, Colin

2015-05-01

Improving tractive effort is a very complex task in locomotive design. It requires the development of not only mechanical systems but also power systems, traction machines and traction algorithms. At the initial design stage, traction algorithms can be verified by means of a simulation approach. A simple single wheelset simulation approach is not sufficient because all locomotive dynamics are not fully taken into consideration. Given that many traction control strategies exist, the best solution is to use more advanced approaches for such studies. This paper describes the modelling of a locomotive with a bogie traction control strategy based on a co-simulation approach in order to deliver more accurate results. The simplified and advanced modelling approaches of a locomotive electric power system are compared in this paper in order to answer a fundamental question. What level of modelling complexity is necessary for the investigation of the dynamic behaviours of a heavy-haul locomotive running under traction? The simulation results obtained provide some recommendations on simulation processes and the further implementation of advanced and simplified modelling approaches.

Vinpocetine Inhibits Streptococcus pneumoniae–Induced Upregulation of Mucin MUC5AC Expression via Induction of MKP-1 Phosphatase in the Pathogenesis of Otitis Media

PubMed Central

Lee, Ji-Yun; Komatsu, Kensei; Lee, Byung-Cheol; Miyata, Masanori; O’Neill Bohn, Ashley; Xu, Haidong

2015-01-01

Mucin overproduction is a hallmark of otitis media (OM). Streptococcus pneumoniae is one of the most common bacterial pathogens causing OM. Mucin MUC5AC plays an important role in mucociliary clearance of bacterial pathogens. However, if uncontrolled, excessive mucus contributes significantly to conductive hearing loss. Currently, there is a lack of effective therapeutic agents that suppress mucus overproduction. In this study, we show that a currently existing antistroke drug, vinpocetine, a derivative of the alkaloid vincamine, inhibited S. pneumoniae–induced mucin MUC5AC upregulation in cultured middle ear epithelial cells and in the middle ear of mice. Moreover, vinpocetine inhibited MUC5AC upregulation by inhibiting the MAPK ERK pathway in an MKP-1–dependent manner. Importantly, ototopical administration of vinpocetine postinfection inhibited MUC5AC expression and middle ear inflammation induced by S. pneumoniae and reduced hearing loss and pneumococcal loads in a well-established mouse model of OM. Thus, these studies identified vinpocetine as a potential therapeutic agent for inhibiting mucus production in the pathogenesis of OM. PMID:25972475

Electric fence standards comport with human data and AC limits.

PubMed

Kroll, Mark W; Perkins, Peter E; Panescu, Dorin

2015-08-01

The ubiquitous electric fence is essential to modern agriculture and has saved lives by reducing the number of livestock automobile collisions. Modern safety standards such as IEC 60335-2-76 and UL 69 have played a role in this positive result. However, these standards are essentially based on energy and power (RMS current), which have limited direct relationship to cardiac effects. We compared these standards to bioelectrically more relevant units of charge and average current in view of recent work on VF (ventricular fibrillation) induction and to existing IEC AC current limits. There are 3 limits for normal (low) pulsing rate: IEC energy limit, IEC current limit, and UL current limit. We then calculated the delivered charge allowed for each pulse duration for these limits and then compared them to a charge-based safety model derived from published human ventricular-fibrillation induction data. Both the IEC and UL also allow for rapid pulsing for up to 3 minutes. We calculated maximum outputs for various pulse durations assuming pulsing at 10, 20, and 30 pulses per second. These were then compared to standard utility power safety (AC) limits via the conversion factor of 7.4 to convert average current to RMS current for VF risk. The outputs of TASER electrical weapons (typically < 100 μC and ~100 μs duration) were also compared. The IEC and UL electric fence energizer normal rate standards are conservative in comparison with actual human laboratory experiments. The IEC and UL electric fence energizer rapid-pulsing standards are consistent with accepted IEC AC current limits for commercially used pulse durations.

Investigation of re-use options for used traction sand.

DOT National Transportation Integrated Search

2010-06-01

The Colorado Department of Transportation (CDOT) uses approximately 24,000 tons of traction sand annually, : especially in mountain locations. Once traction sand is applied, street sweepers reclaim approximately 50% of the : sand, which is either sto...

Orthodontic traction of a transmigrated mandibular canine using mini-implant: a case report and review.

PubMed

Plaza, Sonia Patricia

2016-12-01

The patient in this case is an 11-year-old girl, whose mandibular left canine was transmigrated. The traction to the arch was assisted by using a temporary skeletal anchorage device. After 5 months of poor response to traction, the biomechanics were re-adjusted, obtaining effective traction in to the arch in 12 months. After this period, the treatment was completed with fixed orthodontic appliances.

Traction and lubricant film temperature as related to the glass transition temperature and solidification. [using infrared spectroscopy on EHD contacts

NASA Technical Reports Server (NTRS)

Lauer, J. L.; Peterkin, M. E.

1978-01-01

Does a traction fluid have to be a glass or solid under operating conditions. Infrared spectra on dynamic EHD contacts of several types of fluid were used to determine the surface and oil-film temperatures. Polarized spectral runs were made to study molecular alignment. Static glass transition pressures at appropriate temperatures were between 0.1 and 2.0 GPa, with the traction fluid showing the highest. In the EHD contact region, the traction fluid showed both the highest film temperatures as well as the greatest degree of molecular alignment. A plot of the difference between the film and surface temperatures vs shear rate resulted in a master plot valid for all the fluids. From this work, the authors propose a model of 'fluid' traction, where friction between parallel rough molecules provides the traction.

Study on Stability of High Speed Traction Drive CVT for Aircraft Generator

NASA Astrophysics Data System (ADS)

Goi, Tatsuhiko; Tanaka, Hirohisa; Nakashima, Kenichi; Watanabe, Koji

A half-toroidal traction drive CVT has a feature of small spin at traction pitch in whole speed ratio range of 1:4, which suits to transmit high rotational speed with minimum temperature increase of traction surface. Research activity on traction drive CVT has commenced in 1996 for applying it to an aircraft 24,000rpm constant-speed generator instead of a hydro-static transmission. This paper shows fundamental design of 90kW traction drive integrated drive generator, ``T-IDG", and stability analysis on a sensor-less electro-hydraulic speed control servo-mechanism by bond graphs. The performance test of T-IDG mounted on a test bench and an actual jet engine proved that the control system using sensor-less servomechanism can keep the generator speed within MIL-STD-704E allowable limit against steep changes of speed and load.

Friction self-oscillation decrease in nonlinear system of locomotive traction drive

NASA Astrophysics Data System (ADS)

Antipin, D. Ya; Vorobiyov, V. I.; Izmerov, O. V.; Shorokhov, S. G.; Bondarenko, D. A.

2017-02-01

The problems of the friction self-oscillation decrease in a nonlinear system of a locomotive traction drive are considered. It is determined that the self-oscillation amplitude decrease in a locomotive wheel pair during boxing in traction drives with an elastic linkage between an armature of a traction electric motor and gearing can be achieved due to drive damping capacity during impact vibro-damping in an axle reduction gear with a hard driven gear. The self-oscillation amplitude reduction in a wheel pair in the designs of locomotive traction drives with the location of elastic elements between a wheel pair and gearing can be obtained owing to the application of drive inertial masses as an anti-vibrator. On the basis of the carried out investigations, a design variant of a self-oscillation shock absorber of a traction electric motor framework on a reduction gear suspension with an absorber located beyond a wheel-motor unit was offered.

Evaluation of accessory cell heterogeneity. I. Differential accessory cell requirement for T helper cell activation and for T-B cooperation.

PubMed

Ramila, G; Studer, S; Kennedy, M; Sklenar, I; Erb, P

1985-01-01

Several Ia+ tumor cell lines and peritoneal exudate macrophages were tested as accessory cells (AC) for the activation of antigen-specific T cells and for T-B cooperation. The macrophages and all the Ia+ tumor lines tested induced the release of lymphokines from T cells in a major histocompatibility complex (MHC)-restricted fashion and reconstituted the antibody responses of AC-depleted spleen cells or of purified T and B cells. However, only the normal macrophages but none of the tumor lines induced carrier-specific T helper (Th) cells which help B cells for specific antihapten antibody responses by linked recognition. For T-B cooperation accessory cells were also required, but in contrast to Th cell activation any type of Ia+ AC (e.g. macrophage or tumor line) was effective. Strong MHC-restriction between the lymphocytes and the AC was seen if antigen-pulsed AC were added into the AC-depleted T-B cooperation cultures. If the AC and antigen were concomitantly added to the AC-depleted T-B cultures, MHC-restriction was less obvious. Concanavalin A supernatant reconstituted the response of AC-depleted T-B cultures provided antigen-specific Th cells and the hapten-carrier conjugate were present. If, however, tumor line-activated T cells were added instead of macrophage-induced Th cells, no cooperation with B cells took place even in the presence of Con A supernatant. The results obtained demonstrate a differential AC requirement for the induction of Th cells depending on the differentiation stage of the Th cells.

EFFICIENCY OPTIMIZATIN CONTROL OF AC INDUCTION MOTORS: INITIAL LABORATORY RESULTS

EPA Science Inventory

The report discusses the development of a fuzzy logic, energy-optimizing controller to improve the efficiency of motor/drive combinations that operate at varying loads and speeds. This energy optimizer is complemented by a sensorless speed controller that maintains motor shaft re...

Case report: Osteonecrosis of the femoral head after hip arthroscopy.

PubMed

Scher, Danielle L; Belmont, Philip J; Owens, Brett D

2010-11-01

Hip arthroscopy is a common orthopaedic procedure used as a diagnostic and therapeutic tool with a multitude of surgical indications. The complication rate is reportedly between 1.3% and 23.3%. Major complications are related to traction, fluid extravasation, and iatrogenic chondral injury. Although osteonecrosis is a concern with any surgical procedure about the hip, this complication has been primarily a theoretical concern with hip arthroscopy. We report the case of a 24-year-old man who presented with a 2-year history of left hip pain. He underwent hip arthroscopy to include débridement of a torn labrum and removal of a prominent pincer lesion for femoroacetabular impingement. Traction was initiated by applying manual traction to the traction bar until 10 mm of joint distraction was obtained. Traction was removed at 90 minutes. At the 3-month followup, MRI showed osteonecrosis in the subcapital region of the left femoral head. It generally is agreed the magnitude and duration of traction during hip arthroscopy increase the risk of traction-related injuries. Only one previous case of femoral head osteonecrosis associated with hip arthroscopy has been reported, and this may have resulted from the initial traumatic event. Based on anatomic studies, the use of standard arthroscopic portals would not put at risk any dominant normal vascular structures supplying the femoral head. In contrast, the literature shows that femoral head osteonecrosis may develop secondary to a combination of increased intraarticular pressure and traction. We suspect this case of femoral head osteonecrosis after hip arthroscopy was caused by traction used in the procedure.

Testing and evaluation of recovered traction sanding material.

DOT National Transportation Integrated Search

2013-04-01

The Montana Department of Transportation (MDT) is searching for a solution to the accumulation of traction sand that is applied to Montana highways every winter. An analysis of reuse and recycle options for salvaged traction sand was conducted using ...

Rolling-element fatigue life with two synthetic cycloaliphatic traction fluids

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Parker, R. J.

1976-01-01

The life potential of two synthetic cycloaliphatic hydrocarbon traction fluids in rolling element fatigue was evaluated in a five ball fatigue tester. Life comparisons with a MIL-L-23699 qualified tetraester oil showed that the traction test oils had good fatigue life performance, comparable to that of the tetraester oil. No statistically significant life differences between the traction fluids and the tetraester oil were exhibited under the accelerated fatigue test conditions. Erratic operating behavior was occasionally encountered during tests with the antiwear additive containing traction fluid for reasons thought to be related to excessive chemical activity under high contact pressure. This behavior occasionally resulted in premature test termination due to excessive surface distress and overheating.

Piezoelectric response of a PZT thin film to magnetic fields from permanent magnet and coil combination

NASA Astrophysics Data System (ADS)

Guiffard, B.; Seveno, R.

2015-01-01

In this study, we report the magnetically induced electric field E 3 in Pb(Zr0.57Ti0.43)O3 (PZT) thin films, when they are subjected to both dynamic magnetic induction (magnitude B ac at 45 kHz) and static magnetic induction ( B dc) generated by a coil and a single permanent magnet, respectively. It is found that highest sensitivity to B dc——is achieved for the thin film with largest effective electrode. This magnetoelectric (ME) effect is interpreted in terms of coupling between eddy current-induced Lorentz forces (stress) in the electrodes of PZT and piezoelectricity. Such coupling was evidenced by convenient modelling of experimental variations of electric field magnitude with both B ac and B dc induction magnitudes, providing imperfect open circuit condition was considered. Phase angle of E 3 versus B dc could also be modelled. At last, the results show that similar to multilayered piezoelectric-magnetostrictive composite film, a PZT thin film made with a simple manufacturing process can behave as a static or dynamic magnetic field sensor. In this latter case, a large ME voltage coefficient of under B dc = 0.3 T was found. All these results may provide promising low-cost magnetic energy harvesting applications with microsized systems.

Electric Transport Traction Power Supply System With Distributed Energy Sources

NASA Astrophysics Data System (ADS)

Abramov, E. Y.; Schurov, N. I.; Rozhkova, M. V.

2016-04-01

The paper states the problem of traction substation (TSS) leveling of daily-load curve for urban electric transport. The circuit of traction power supply system (TPSS) with distributed autonomous energy source (AES) based on photovoltaic (PV) and energy storage (ES) units is submitted here. The distribution algorithm of power flow for the daily traction load curve leveling is also introduced in this paper. In addition, it illustrates the implemented experiment model of power supply system.

Enhanced acetyl-CoA production is associated with increased triglyceride accumulation in the green alga Chlorella desiccata

PubMed Central

Avidan, Omri; Brandis, Alexander; Rogachev, Ilana; Pick, Uri

2015-01-01

Triglycerides (TAGs) from microalgae can be utilized as food supplements and for biodiesel production, but little is known about the regulation of their biosynthesis. This work aimed to test the relationship between acetyl-CoA (Ac-CoA) levels and TAG biosynthesis in green algae under nitrogen deprivation. A novel, highly sensitive liquid chromatography mass spectrometry (LC-MS/MS) technique enabled us to determine the levels of Ac-CoA, malonyl-CoA, and unacetylated (free) CoA in green microalgae. A comparative study of three algal species that differ in TAG accumulation levels shows that during N starvation, Ac-CoA levels rapidly rise, preceding TAG accumulation in all tested species. The levels of Ac-CoA in the high TAG accumulator Chlorella desiccata exceed the levels in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Similarly, malonyl-CoA and free CoA levels also increase, but to lower extents. Calculated cellular concentrations of Ac-CoA are far lower than reported K mAc-CoA values of plastidic Ac-CoA carboxylase (ptACCase) in plants. Transcript level analysis of plastidic pyruvate dehydrogenase (ptPDH), the major chloroplastic Ac-CoA producer, revealed rapid induction in parallel with Ac-CoA accumulation in C. desiccata, but not in D. tertiolecta or C. reinhardtii. It is proposed that the capacity to accumulate high TAG levels in green algae critically depends on their ability to divert carbon flow towards Ac-CoA. This requires elevation of the chloroplastic CoA pool level and enhancement of Ac-CoA biosynthesis. These conclusions may have important implications for future genetic manipulation to enhance TAG biosynthesis in green algae. PMID:25922486

Elastohydrodynamic Traction Properties of Seed Oils

USDA-ARS?s Scientific Manuscript database

The elastohydrodynamic traction coefficient (tc) properties of nine seed oils of varying chemical structures, PAO and hexadecane, were investigated using a ball-on disk traction apparatus. The seed oils were: castor oil, a triglyceride with hydroxyl functional group; jojoba, a monoglyceride; and s...

Energy efficiency analysis of two-sided feed scheme of DC traction network with high asymmetry of feeders parameters

NASA Astrophysics Data System (ADS)

Abramov, E. Y.; Sopov, V. I.

2017-10-01

In a given research using the example of traction network area with high asymmetry of power supply parameters, the sequence of comparative assessment of power losses in DC traction network with parallel and traditional separated operating modes of traction substation feeders was shown. Experimental measurements were carried out under these modes of operation. The calculation data results based on statistic processing showed the power losses decrease in contact network and the increase in feeders. The changes proved to be critical ones and this demonstrates the significance of potential effects when converting traction network areas into parallel feeder operation. An analytical method of calculation the average power losses for different feed schemes of the traction network was developed. On its basis, the dependences of the relative losses were obtained by varying the difference in feeder voltages. The calculation results showed unreasonableness transition to a two-sided feed scheme for the considered traction network area. A larger reduction in the total power loss can be obtained with a smaller difference of the feeders’ resistance and / or a more symmetrical sectioning scheme of contact network.

Integral Sensor Fault Detection and Isolation for Railway Traction Drive.

PubMed

Garramiola, Fernando; Del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

2018-05-13

Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive.

Integral Sensor Fault Detection and Isolation for Railway Traction Drive

PubMed Central

del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

2018-01-01

Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive. PMID:29757251

HO-1 inhibits IL-13-induced goblet cell hyperplasia associated with CLCA1 suppression in normal human bronchial epithelial cells.

PubMed

Mishina, Kei; Shinkai, Masaharu; Shimokawaji, Tadasuke; Nagashima, Akimichi; Hashimoto, Yusuke; Inoue, Yoriko; Inayama, Yoshiaki; Rubin, Bruce K; Ishigatsubo, Yoshiaki; Kaneko, Takeshi

2015-12-01

Mucus hypersecretion and goblet cell hyperplasia are common features that characterize asthma. IL-13 increases mucin (MUC) 5AC, the major component of airway mucus, in airway epithelial cells. According to the literature, IL-13 receptor activation leads to STAT6 activation and consequent induction of chloride channel accessory 1 (CLCA1) gene expression, associated with the induction of MUC5AC. Heme oxygenase-1 (HO-1) is an enzyme that catalyzes oxidation of heme to biliverdin, and has anti-inflammatory and anti-oxidant properties. We examined the effects of HO-1 on mucin production and goblet cell hyperplasia induced by IL-13. Moreover, we assessed the cell signaling intermediates that appear to be responsible for mucin production. Normal human bronchial epithelial (NHBE) cells were grown at air liquid interface (ALI) in the presence or absence of IL-13 and hemin, a HO-1 inducer, for 14 days. Protein concentration was analyzed using ELISA, and mRNA expression was examined by real-time PCR. Histochemical analysis was performed using HE staining, andWestern blotting was performed to evaluate signaling transduction pathway. Hemin (4 μM) significantly increased HO-1 protein expression (p b 0.01) and HO-1 mRNA expression (p b 0.001). IL-13 significantly increased goblet cells, MUC5AC protein secretion (p b 0.01) and MUC5AC mRNA (p b 0.001), and these were decreased by hemin by way of HO-1. Tin protoporphyrin (SnPP)-IX, a HO-1 inhibitor, blocked the effect of hemin restoring MUC5AC protein secretion (p b 0.05) and goblet cell hyperplasia. Hemin decreased the expression of CLCA1 mRNA (p b 0.05) and it was reversed by SnPP-IX, but could not suppress IL-13-induced phosphorylation of STAT6 or SAM pointed domain-containing ETS transcription factor (SPDEF) and Forkhead box A2 (FOXA2) mRNA expression. In summary, HO-1 overexpression suppressed IL-13-induced goblet cell hyperplasia and MUC5AC production, and involvement of CLCA1 in the mechanism was suggested.

Magnetic Design Guidelines for Electronic Power Supplies.

DTIC Science & Technology

1986-09-30

henries ",= peak flux density in gauss d = wire (conductor) dia in mils CM = d2 = circular mi’s Irms = RMS current in amperes Idc = DC current in...component lac = RMS ac current in the inductor f = minimum frequency in hertz L = inductance in henries Then Eac 2 16.83 x 2, x 760 x .05 10 Eac 1 168.3 x 2...duty cycle x 1/f L inductance in henries *permeability in gauss/oersted H magnetizing force in oersteds ’. i g length of air gap in cm ic length of

Elastohydrodynamic (EHD) traction properties of seed oils

USDA-ARS?s Scientific Manuscript database

The elastohydrodynamic traction coefficient (tc) properties of nine seed oils of varying chemical structures, PAO and hexadecane, were investigated using a ball-on disk traction apparatus. The seed oils were: castor oil, a triglyceride with hydroxyl functional group; jojoba, a monoglyceride; and sev...

Bi-directional four quadrant (BDQ4) power converter development

NASA Technical Reports Server (NTRS)

Schwarz, F. C.

1979-01-01

The feasibility for implementation of a concept for direct ac/dc multikilowatt power conversion with bidirectional transfer of energy was investigated. A 10 kHz current carrier was derived directly from a common 60 Hz three phase power system. This carrier was modulated to remove the 360 Hz ripple, inherent in the three phase power supply and then demodulated and processed by a high frequency filter. The resulting dc power was then supplied to a load. The process was implemented without the use of low frequency transformers and filters. This power conversion processes was reversible and can operate in the four quadrants as viewed from any of the two of the converter's ports. Areas of application include: power systems on air and spacecraft; terrestrial traction; integration of solar and wind powered systems with utility networks; HVDC; asynchronous coupling of polyphase networks; heat treatment; industrial machine drives; and power supplies for any use including instrumentation.

Diagnosis of unstable cervical spine injuries: laboratory support for the use of axial traction to diagnose cervical spine instability.

PubMed

Kalantar, Babak S; Hipp, John A; Reitman, Charles A; Dreiangel, Niv; Ben-Galim, Peleg

2010-10-01

The ability to detect damage to the intervertebral structures is critical in the management of patients after blunt trauma. A practical and inexpensive method to identify severe structural damage not clearly seen on computed tomography would be of benefit. The objective of this study was to assess whether ligamentous injury in the subaxial cervical spine can be reliably detected by analysis of lateral radiographs taken with and without axial traction. Twelve fresh, whole, postrigor-mortis cadavers were used for this study. Lateral cervical spine radiographs were obtained during the application of 0 N, 89 N, and 178 N of axial traction applied to the head. Progressive incremental sectioning of posterior structures was then performed at C4-C5 with traction imaging repeated after each intervention. Intervertebral distraction was analyzed using computer-assisted software. Almost imperceptible intervertebral separation was found when traction was applied to intact spines. In the subaxial cervical spine, the average posterior disc height consistently increased under traction in severely injured spines. The average disc height increase was 14% of the C4 upper endplate width, compared with an average of 2% in the noninjured spines. A change of more than 5% in posterior disc height under traction was above the 95% confidence interval for intact spines, with sensitivity of 83% and specificity of 80%. Applied force of 89 N (20 lb) was sufficient to demonstrate injury. The combination of assessing alignment and distraction under traction increased both the sensitivity and specificity to nearly 100%. This study supports further clinical investigations to determine whether low-level axial traction may be a useful adjunct for detecting unstable subaxial cervical spine injuries in an acute setting.

Acetyl-CoA synthetase is activated as part of the PDH-bypass in the oleaginous green alga Chlorella desiccata

PubMed Central

Avidan, Omri; Pick, Uri

2015-01-01

In a recent study, it has been shown that biosynthesis of triacylglycerol (TAG) in the oleaginous green alga Chlorella desiccata is preceded by a large increase in acetyl-coenzyme A (Ac-CoA) levels and by upregulation of plastidic pyruvate dehydrogenase (ptPDH). It was proposed that the capacity to accumulate high TAG critically depends on enhanced production of Ac-CoA. In this study, two alternative Ac-CoA producers—plastidic Ac-CoA synthase (ptACS) and ATP citrate lyase (ACL)—are shown to be upregulated prior to TAG accumulation under nitrogen deprivation in the oleaginous species C. desiccata, but not in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Measurements of endogenous acetate production and of radiolabelled acetate incorporation into lipids are consistent with the upregulation of ptACS, but suggest that its contribution to the overall TAG biosynthesis is negligible. Induction of ACS and production of endogenous acetate are correlated with activation of alcohol dehydrogenase, suggesting that the upregulation of ptACS is associated with activation of PDH-bypass in C. desiccata. It is proposed that activation of the PDH-bypass in C. desiccata is needed to enable a high rate of lipid biosynthesis under nitrogen deprivation by controlling the level of pyruvate reaching ptPHD and/or mtPDH. This may be an important parameter for massive TAG accumulation in microalgae. PMID:26357883

Acetyl-CoA synthetase is activated as part of the PDH-bypass in the oleaginous green alga Chlorella desiccata.

PubMed

Avidan, Omri; Pick, Uri

2015-12-01

In a recent study, it has been shown that biosynthesis of triacylglycerol (TAG) in the oleaginous green alga Chlorella desiccata is preceded by a large increase in acetyl-coenzyme A (Ac-CoA) levels and by upregulation of plastidic pyruvate dehydrogenase (ptPDH). It was proposed that the capacity to accumulate high TAG critically depends on enhanced production of Ac-CoA. In this study, two alternative Ac-CoA producers-plastidic Ac-CoA synthase (ptACS) and ATP citrate lyase (ACL)-are shown to be upregulated prior to TAG accumulation under nitrogen deprivation in the oleaginous species C. desiccata, but not in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Measurements of endogenous acetate production and of radiolabelled acetate incorporation into lipids are consistent with the upregulation of ptACS, but suggest that its contribution to the overall TAG biosynthesis is negligible. Induction of ACS and production of endogenous acetate are correlated with activation of alcohol dehydrogenase, suggesting that the upregulation of ptACS is associated with activation of PDH-bypass in C. desiccata. It is proposed that activation of the PDH-bypass in C. desiccata is needed to enable a high rate of lipid biosynthesis under nitrogen deprivation by controlling the level of pyruvate reaching ptPHD and/or mtPDH. This may be an important parameter for massive TAG accumulation in microalgae. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Phosphorylation of 1-Aminocyclopropane-1-Carboxylic Acid Synthase by MPK6, a Stress-Responsive Mitogen-Activated Protein Kinase, Induces Ethylene Biosynthesis in ArabidopsisW⃞

PubMed Central

Liu, Yidong; Zhang, Shuqun

2004-01-01

Mitogen-activated protein kinases (MAPKs) are implicated in regulating plant growth, development, and response to the environment. However, the underlying mechanisms are unknown because of the lack of information about their substrates. Using a conditional gain-of-function transgenic system, we demonstrated that the activation of SIPK, a tobacco (Nicotiana tabacum) stress-responsive MAPK, induces the biosynthesis of ethylene. Here, we report that MPK6, the Arabidopsis thaliana ortholog of tobacco SIPK, is required for ethylene induction in this transgenic system. Furthermore, we found that selected isoforms of 1-aminocyclopropane-1-carboxylic acid synthase (ACS), the rate-limiting enzyme of ethylene biosynthesis, are substrates of MPK6. Phosphorylation of ACS2 and ACS6 by MPK6 leads to the accumulation of ACS protein and, thus, elevated levels of cellular ACS activity and ethylene production. Expression of ACS6DDD, a gain-of-function ACS6 mutant that mimics the phosphorylated form of ACS6, confers constitutive ethylene production and ethylene-induced phenotypes. Increasing numbers of stress stimuli have been shown to activate Arabidopsis MPK6 or its orthologs in other plant species. The identification of the first plant MAPK substrate in this report reveals one mechanism by which MPK6/SIPK regulates plant stress responses. Equally important, this study uncovers a signaling pathway that modulates the biosynthesis of ethylene, an important plant hormone, in plants under stress. PMID:15539472

Auxiliary power unit for moving a vehicle

DOEpatents

Akasam, Sivaprasad [Peoria, IL; Johnson, Kris W [Peoria, IL; Johnson, Matthew D [Peoria, IL; Slone, Larry M [Washington, IL; Welter, James Milton [Chillicothe, IL

2009-02-03

A power system is provided having at least one traction device and a primary power source configured to power the at least one traction device. In addition, the power system includes an auxiliary power source also configured to power the at least one traction device.

Advanced dc-Traction-Motor Control System

NASA Technical Reports Server (NTRS)

Vittone, O.

1985-01-01

Motor-control concept for battery-powered vehicles includes stateof-the-art power-transistor switching and separate excitation of motor windings in traction and regenerative braking. Switching transistors and other components of power-conditioning subsystem operate under control of computer that coordinates traction, braking, and protective functions.

Cellular traction force recovery: An optimal filtering approach in two-dimensional Fourier space.

PubMed

Huang, Jianyong; Qin, Lei; Peng, Xiaoling; Zhu, Tao; Xiong, Chunyang; Zhang, Youyi; Fang, Jing

2009-08-21

Quantitative estimation of cellular traction has significant physiological and clinical implications. As an inverse problem, traction force recovery is essentially susceptible to noise in the measured displacement data. For traditional procedure of Fourier transform traction cytometry (FTTC), noise amplification is accompanied in the force reconstruction and small tractions cannot be recovered from the displacement field with low signal-noise ratio (SNR). To improve the FTTC process, we develop an optimal filtering scheme to suppress the noise in the force reconstruction procedure. In the framework of the Wiener filtering theory, four filtering parameters are introduced in two-dimensional Fourier space and their analytical expressions are derived in terms of the minimum-mean-squared-error (MMSE) optimization criterion. The optimal filtering approach is validated with simulations and experimental data associated with the adhesion of single cardiac myocyte to elastic substrate. The results indicate that the proposed method can highly enhance SNR of the recovered forces to reveal tiny tractions in cell-substrate interaction.

Fluidization, resolidification, and reorientation of the endothelial cell in response to slow tidal stretches

PubMed Central

Krishnan, Ramaswamy; Canović, Elizabeth Peruski; Iordan, Andreea L.; Rajendran, Kavitha; Manomohan, Greeshma; Pirentis, Athanassios P.; Smith, Michael L.; Butler, James P.; Fredberg, Jeffrey J.

2012-01-01

Mechanical stretch plays an important role in regulating shape and orientation of the vascular endothelial cell. This morphological response to stretch is basic to angiogenesis, neovascularization, and vascular homeostasis, but mechanism remains unclear. To elucidate mechanisms, we used cell mapping rheometry to measure traction forces in primary human umbilical vein endothelial cells subjected to periodic uniaxial stretches. Onset of periodic stretch of 10% strain amplitude caused a fluidization response typified by attenuation of traction forces almost to zero. As periodic stretch continued, the prompt fluidization response was followed by a slow resolidification response typified by recovery of the traction forces, but now aligned along the axis perpendicular to the imposed stretch. Reorientation of the cell body lagged reorientation of the traction forces, however. Together, these observations demonstrate that cellular reorientation in response to periodic stretch is preceded by traction attenuation by means of cytoskeletal fluidization and subsequent traction recovery transverse to the stretch direction by means of cytoskeletal resolidification. PMID:22700796

Effects of intermittent traction therapy in an experimental spinal column model.

PubMed

Shin, Jeong-Hun; Jun, Seung-lyul; Lee, Young-Jun; Kim, Jae-Hyo; Hwang, Sung-Yeoun; Ahn, Seong-Hun

2014-04-01

Traction therapy, which is known to be a treatment method for scoliosis, one of many muscles disease, has been used since Hippocrates introduced it. However, the effects of traction therapy are still not clear. In addition, the meridian sinew theory, which is related to muscle treatment and is mentioned in the book on meridian sinews in the Miraculous Pivot of Huangdi's Internal Classic, has not been the subject of much study. For these reasons, experimental spinal models were made for this study to observe and analyze the lengths of vertebral interspaces after intermittent traction therapy, which is known to be excellent among muscle treatment methods, with various tensile forces. The results showed that the effects of intermittent traction therapy were unclear and that it might be harmful, especially when the pain was induced by muscle weakness. Because the results of this study on intermittent traction therapy were different from those expected from osteopathy or craniosacral theory, better studies of the subject are necessary. Copyright © 2014. Published by Elsevier B.V.

A novel solid-state fractionation of naphthenic acid fraction components from oil sands process-affected water.

PubMed

Mohamed, Mohamed H; Wilson, Lee D; Shah, Jaimin R; Bailey, Jon; Peru, Kerry M; Headley, John V

2015-10-01

Various sorbent materials were evaluated for the fractionation of naphthenic acid fraction components (NAFCs) from oil sand process-affected water (OSPW). The solid phase materials include activated carbon (AC), cellulose, iron oxides (magnetite and goethite), polyaniline (PANI) and three types of biochar derived from biomass (BC-1; rice husks, BC-2; acacia low temperature and BC-3; acacia high temperature). NAFCs were semi-quantified using electrospray ionization high resolution Orbitrap mass spectrometry (ESI-MS) and the metals were assessed by inductively coupled plasma optical emission spectrometry (ICP-OES). The average removal efficacy of NAFCs by AC was 95%. The removal efficacy decreased in the following order: AC, BC-1>BC-2, BC-3, goethite>PANI>cellulose, magnetite. The removal of metals did not follow a clear trend; however, there was notable leaching of potassium by AC and biochar samples. The bound NAFCs by AC were desorbed efficiently with methanol. Methanol regeneration and recycling of AC revealed 88% removal on the fourth cycle; a 4.4% decrease from the first cycle. This fractionation method represents a rapid, cost-effective, efficient, and green strategy for NAFCs from OSPW, as compared with conventional solvent extraction. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Research on the stability of teaching robots of rotation-traction manipulation].

PubMed

Feng, Min-Shan; Zhu, Li-Guo; Wang, Shang-Quan; Yu, Jie; Chen, Ming; Li, Ling-Hui; Wei, Xu

2017-03-25

To evaluate the stability of teaching robot of rotation-traction manipulation. Operators were required to get the hang of rotation-traction manipulation and had clinical experience for over 5 years. The examination and data processing of the ten operators in our research were collected by the teaching robot of rotation-traction manipulation. Traction, pulling force, maximum force, pulling time, rotational amplitude and pitch range were recorded and compared for five times(G1, G2, G3, G4 and G5). The qualification rates were analyzed to evaluate the stability of teaching robot of rotation-traction manipulation. Nonconforming items were found in G1 and G2, for instance, pulling force( P =0.074), maximum force( P =0.264) and rotational amplitude ( P =0.531). There was no statistically difference. None nonconforming item was found in G3, G4 and G5. All data were processed by SPSS and One-way ANOVA was used to analysis. Pulling force was found statistically different in G1, compared with G4 and G5( P =0.015, P =0.006). Maximum force was found statistically different in G1, compared with G4 and G5 ( P =0.021, P =0.012). None differences were found in other comparisons ( P >0.05). The teaching robot of rotation-traction manipulation used in our research could provide objective and quantitative indices and was considered to be an effective tool of assessing the rotation-traction manipulation.

Inductive detection of fieldlike and dampinglike ac inverse spin-orbit torques in ferromagnet/normal-metal bilayers

NASA Astrophysics Data System (ADS)

Berger, Andrew J.; Edwards, Eric R. J.; Nembach, Hans T.; Karenowska, Alexy D.; Weiler, Mathias; Silva, Thomas J.

2018-03-01

Functional spintronic devices rely on spin-charge interconversion effects, such as the reciprocal processes of electric field-driven spin torque and magnetization dynamics-driven spin and charge flow. Both dampinglike and fieldlike spin-orbit torques have been observed in the forward process of current-driven spin torque and dampinglike inverse spin-orbit torque has been well studied via spin pumping into heavy metal layers. Here, we demonstrate that established microwave transmission spectroscopy of ferromagnet/normal metal bilayers under ferromagnetic resonance can be used to inductively detect the ac charge currents driven by the inverse spin-charge conversion processes. This technique relies on vector network analyzer ferromagnetic resonance (VNA-FMR) measurements. We show that in addition to the commonly extracted spectroscopic information, VNA-FMR measurements can be used to quantify the magnitude and phase of all ac charge currents in the sample, including those due to spin pumping and spin-charge conversion. Our findings reveal that Ni80Fe20/Pt bilayers exhibit both dampinglike and fieldlike inverse spin-orbit torques. While the magnitudes of both the dampinglike and fieldlike inverse spin-orbit torque are of comparable scale to prior reported values for similar material systems, we observed a significant dependence of the dampinglike magnitude on the order of deposition. This suggests interface quality plays an important role in the overall strength of the dampinglike spin-to-charge conversion.

Hypoxia induces mucin expression and secretion in human bronchial epithelial cells.

PubMed

Zhou, Xiangdong; Tu, Jing; Li, Qi; Kolosov, Victor P; Perelman, Juliy M

2012-12-01

The study objective was to investigate the role of hypoxia-inducible factor 1 (HIF-1) in the transcriptional activation of MUC5AC in human bronchial epithelial (HBE) 16 cells under hypoxia conditions and the effect of hypoxia on expression and secretion of MUC5AC. Cells were incubated in hypoxia medium. Serial deletions or mutations of the MUC5AC promoter were cloned in the reporter pGL3-basic plasmid (Promega Biotech Co, Ltd, Beijing, China). These reporter plasmids were cotransfected with HIF-1α small interfering RNA. Hypoxia markedly increased the level of MUC5AC secretion and the transcriptional activity of MUC5AC promoters. Western blot analysis showed that HIF-1α and MUC5AC proteins were strongly increased after HBE16 cells were exposed to hypoxic conditions. Treatment of HBE16 cells with HIF-1α inhibitor (YC-1) or HIF-1α small interfering RNA significantly inhibited the expression of HIF-1α and MUC5AC, and the secretion of MUC5AC. Depletion of the promoter sequence did not reduce the MUC5AC promoter activity to hypoxia. Luciferase assay indicated that HRE in the MUC5AC promoter was in the region from -120 to +54. Promoter sequence analysis showed that 1 HRE site at -65 plays an important role in hypoxia activation of the MUC5AC. The inactivation of the HRE site using site-directed mutagenesis led to the complete loss of induction by hypoxia, which further confirmed the key role of the HRE site. MUC5AC expression and secretion are upregulated in response to hypoxia. The HRE site at -65 in the MUC5AC promoter and the HIF-1α are the major regulators for the cellular response against hypoxia in human bronchial epithelial cells. Copyright © 2012 Mosby, Inc. All rights reserved.

Generation of sonic power during welding

NASA Technical Reports Server (NTRS)

Mc Campbell, W. M.

1969-01-01

Generation of intense sonic and ultrasonic power in the weld zone, close to the puddle, reduces the porosity and refinement of the grain. The ac induction brazing power supply is modified with long cables for deliberate addition of resistance to that circuit. The concept is extensible to the molding of metals and plastics.

New propulsion components for electric vehicles

NASA Technical Reports Server (NTRS)

Secunde, R. R.

1982-01-01

Improved component technology is described. This includes electronically commutated permanent magnet motors of both drum and disk configurations, an unconventional brush commutated motor, ac induction motors, various controllers, transmissions and complete systems. One or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

21 CFR 888.5890 - Noninvasive traction component.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Noninvasive traction component. 888.5890 Section 888.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5890 Noninvasive traction component. (a...

21 CFR 888.5890 - Noninvasive traction component.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Noninvasive traction component. 888.5890 Section 888.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5890 Noninvasive traction component. (a...

21 CFR 888.5890 - Noninvasive traction component.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Noninvasive traction component. 888.5890 Section 888.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5890 Noninvasive traction component. (a...

21 CFR 888.5890 - Noninvasive traction component.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Noninvasive traction component. 888.5890 Section 888.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5890 Noninvasive traction component. (a...

21 CFR 888.5890 - Noninvasive traction component.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Noninvasive traction component. 888.5890 Section 888.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5890 Noninvasive traction component. (a...

21 CFR 890.5900 - Power traction equipment.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Power traction equipment. 890.5900 Section 890.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5900 Power traction...

21 CFR 890.5925 - Traction accessory.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory. (a...

21 CFR 890.5900 - Power traction equipment.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Power traction equipment. 890.5900 Section 890.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5900 Power traction...

21 CFR 890.5925 - Traction accessory.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory. (a...

21 CFR 890.5925 - Traction accessory.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory. (a...

21 CFR 890.5925 - Traction accessory.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory. (a...

21 CFR 890.5900 - Power traction equipment.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Power traction equipment. 890.5900 Section 890.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5900 Power traction...

21 CFR 890.5925 - Traction accessory.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory. (a...

21 CFR 890.5900 - Power traction equipment.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Power traction equipment. 890.5900 Section 890.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5900 Power traction...

21 CFR 890.5900 - Power traction equipment.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Power traction equipment. 890.5900 Section 890.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5900 Power traction...

Elements affecting runway traction

NASA Technical Reports Server (NTRS)

Horne, W. B.

1974-01-01

The five basic elements affecting runway traction for jet transport aircraft operation are identified and described in terms of pilot, aircraft system, atmospheric, tire, and pavement performance factors or parameters. Where possible, research results are summarized, and means for restoring or improving runway traction for these different conditions are discussed.

IκBNS induces Muc5ac expression in epithelial cells and causes airway hyper-responsiveness in murine asthma models.

PubMed

Yokota, M; Tamachi, T; Yokoyama, Y; Maezawa, Y; Takatori, H; Suto, A; Suzuki, K; Hirose, K; Takeda, K; Nakajima, H

2017-07-01

In allergic asthma, environmental allergens including house dust mite (HDM) trigger pattern recognition receptors and activate downstream signaling pathways including NF-κB pathways not only in immune cells but also in airway epithelial cells. Recent studies have shown that NF-κB activation is regulated positively or negatively depending on the cellular context by IκBNS (encoded by the gene Nfkbid), one of atypical IκB proteins, in the nucleus. Therefore, we hypothesized that IκBNS expressed in immune cells or epithelial cells is involved in the regulation of asthmatic responses. To determine the roles of IκBNS in HDM-induced asthmatic responses. Roles of IκBNS in HDM-induced airway inflammation and airway hyper-responsiveness (AHR) were examined by using IκBNS-deficient (Nfkbid -/- ) mice. Roles of IκBNS expressed in hematopoietic cells and nonhematopoietic cells were separately evaluated by bone marrow chimeric mice. Roles of IκBNS expressed in murine tracheal epithelial cells (mTECs) were examined by air-liquid interface culture. House dust mite-induced airway inflammation and AHR were exacerbated in mice lacking IκBNS in hematopoietic cells. In contrast, HDM-induced airway inflammation was exacerbated, but AHR was attenuated in mice lacking IκBNS in nonhematopoietic cells. The induction of Muc5ac, a representative mucin in asthmatic airways, was reduced in Nfkbid -/- mTEC, whereas the induction of Spdef, a master regulator of goblet cell metaplasia, was not impaired in Nfkbid -/- mTEC. Moreover, IκBNS bound to and activated the MUC5AC distal promoter in epithelial cells. IκBNS is involved in inducing Muc5ac expression in lung epithelial cells and causing AHR in HDM-induced asthma models. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Zinc-mediated attenuation of hippocampal mossy fiber long-term potentiation induced by forskolin.

PubMed

Ando, Masaki; Oku, Naoto; Takeda, Atsushi

2010-11-01

The rise in presynaptic calcium induced by high-frequency stimulation activates the calcium-calmodulin-sensitive adenylyl cyclase (AC) 1 followed by the induction of long-term potentiation (LTP) at the hippocampal mossy fiber-CA3 synapse. Zinc is released with glutamate from mossy fiber terminals. However, the role of the zinc in mossy fiber LTP is controversial. In the present study, the mechanism of zinc-mediated attenuation of mossy fiber LTP was examined in that induced by forskolin, an AC activator. Mossy fiber LTP induced by tetanic stimulation (100 Hz for 1 s) was attenuated in the presence of 5 microM ZnCl(2), whereas that induced by forskolin under test stimulation (0.1 Hz) was not attenuated. Forskolin-induced mossy fiber LTP was attenuated by perfusion with 100 microM ZnCl(2) prior to the induction. However, the zinc (100 microM) pre-perfusion did not attenuate mossy fiber LTP induced by Sp-cAMPS, an activator of protein kinase A, under test stimulation. Zinc is necessary to be taken up into mossy fiber boutons for effectively inhibiting AC activity. In hippocampal slices labeled with ZnAF-2 DA, a membrane-permeable zinc indicator, intracellular ZnAF-2 signal was increased during tetanic stimulation in the presence of 5 microM ZnCl(2), but not under test stimulation. Intracellular ZnAF-2 signal was increased under test stimulation in the presence of 100 microM ZnCl(2). These results suggest that zinc taken up into mossy fibers attenuates forskolin-induced mossy fiber LTP via inhibition of AC activity. The significance of endogenous zinc uptake by mossy fibers is discussed focused on tetanus-induced mossy fiber LTP. Copyright 2010 Elsevier Ltd. All rights reserved.

Experiments and Demonstrations in Physics: Bar-Ilan Physics Laboratory (2nd Edition)

NASA Astrophysics Data System (ADS)

Kraftmakher, Yaakov

2014-08-01

The following sections are included: * Data-acquisition systems from PASCO * ScienceWorkshop 750 Interface and DataStudio software * 850 Universal Interface and Capstone software * Mass on spring * Torsional pendulum * Hooke's law * Characteristics of DC source * Digital storage oscilloscope * Charging and discharging a capacitor * Charge and energy stored in a capacitor * Speed of sound in air * Lissajous patterns * I-V characteristics * Light bulb * Short time intervals * Temperature measurements * Oersted's great discovery * Magnetic field measurements * Magnetic force * Magnetic braking * Curie's point I * Electric power in AC circuits * Faraday's law of induction I * Self-inductance and mutual inductance * Electromagnetic screening * LCR circuit I * Coupled LCR circuits * Probability functions * Photometric laws * Kirchhoff's rule for thermal radiation * Malus' law * Infrared radiation * Irradiance and illuminance

Influence of basketball shoe mass, outsole traction, and forefoot bending stiffness on three athletic movements.

PubMed

Worobets, Jay; Wannop, John William

2015-09-01

Prior research has shown that footwear can enhance athletic performance. However, public information is not available on what basketball shoe properties should be selected to maximise movement performance. Therefore, the purpose of the study was to investigate the influence of basketball shoe mass, outsole traction, and forefoot bending stiffness on sprinting, jumping, and cutting performance. Each of these three basketball shoe properties was systematically varied by ± 20% to produce three shoe conditions of varying mass, three conditions of varying traction, and three conditions of varying bending stiffness. Each shoe was tested by 20 recreational basketball players completing maximal effort sprints, vertical jumps, and a cutting drill. Outsole traction had the largest influence on performance, as the participants performed significantly worse in all tests when traction was decreased by 20% (p < 0.001), and performed significantly better in the cutting drill when traction was increased by 20% (p = 0.005). Forefoot bending stiffness had a moderate effect on sprint and cutting performance (p = 0.013 and p = 0.016 respectively) and shoe mass was found to have no effect on performance. Therefore, choosing a shoe with relatively high outsole traction and forefoot bending stiffness should be prioritised, and less concern should be focused on selecting the lightest shoe.

Measuring traction forces of motile dendritic cells on micropost arrays.

PubMed

Ricart, Brendon G; Yang, Michael T; Hunter, Christopher A; Chen, Christopher S; Hammer, Daniel A

2011-12-07

Dendritic cells (DCs) migrate from sites of inflammation to secondary lymphoid organs where they initiate the adaptive immune response. Although motility is essential to DC function, the mechanisms by which they migrate are not fully understood. We incorporated micropost array detectors into a microfluidic gradient generator to develop what we consider to be a novel method for probing low magnitude traction forces during directional migration. We found migration of primary murine DCs is driven by short-lived traction stresses at the leading edge or filopodia. The traction forces generated by DCs are smaller in magnitude than found in neutrophils, and of similar magnitude during chemotaxis and chemokinesis, at 18 ± 1.4 and 16 ± 1.3 nN/cell, respectively. The characteristic duration of local DC traction forces was 3 min. The maximum principal stress in the cell occurred in the plane perpendicular to the axis of motion, forward of the centroid. We illustrate that the spatiotemporal pattern of traction stresses can be used to predict the direction of future DC motion. Overall, DCs show a mode of migration distinct from both mesenchymal cells and neutrophils, characterized by rapid turnover of traction forces in leading filopodia. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Rigid two-axis MEMS force plate for measuring cellular traction force

NASA Astrophysics Data System (ADS)

Takahashi, Hidetoshi; Jung, Uijin G.; Kan, Tetsuo; Tsukagoshi, Takuya; Matsumoto, Kiyoshi; Shimoyama, Isao

2016-10-01

Cellular traction force is one of the important factors for understanding cell behaviors, such as spreading, migration and differentiation. Cells are known to change their behavior according to the mechanical stiffness of the environment. However, the measurement of cell traction forces on a rigid environment has remained difficult. This paper reports a micro-electromechanical systems (MEMS) force plate that provides a cellular traction force measurement on a rigid substrate. Both the high force sensitivity and high stiffness of the substrate were obtained using piezoresistive sensing elements. The proposed force plate consists of a 70 µm  ×  15 µm  ×  5 µm base as the substrate for cultivating a bovine aortic smooth muscle cell, and the supporting beams with piezoresistors on the sidewall and the surface were used to measure the forces in both the horizontal and vertical directions. The spring constant and force resolution of the fabricated force plate in the horizontal direction were 0.2 N m-1 and less than 0.05 µN, respectively. The cell traction force was measured, and the traction force increased by approximately 1 µN over 30 min. These results demonstrate that the proposed force plate is applicable as an effective traction force measurement.

A scoping review of applications and outcomes of traction orthoses and constructs for the management of intra-articular fractures and fracture dislocations in the hand.

PubMed

Packham, Tara L; Ball, Pamela D; MacDermid, Joy C; Bain, James R; DalCin, Arianna

2016-01-01

Intra-articular hand fractures can have devastating consequences for movement and function. The unique nature of the injury and diverse management strategies are a challenge for conducting trials. To conduct a scoping review of traction constructs for the management of intra-articular hand fractures. We conducted a systematic search of the literature, extracting data on the scope and nature of the evidence for traction constructs. Our search yielded 87 articles addressing 3 traction constructs: (1) static traction (n = 17), (2) dynamic external fixation (n = 53), and (3) dynamic orthoses (n = 17). Active range of motion of the target joint was the most frequently reported outcome. Study designs included 36 cohorts, 21 case series, and 9 case studies: 24% contained only technical information. The current literature addressing traction constructs consists primarily of small and low-quality studies. Evidence synthesis could improve the estimation of range of motion outcomes but would not be able to identify the best treatment. Consensus on classification of fracture patterns, routine use of outcome measures, and randomized trials are needed to compare different traction constructs and inform evidence-based care. Scoping review. N/A. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

3D Viscoelastic Traction Force Microscopy

PubMed Central

Toyjanova, Jennet; Hannen, Erin; Bar-Kochba, Eyal; Darling, Eric M.; Henann, David L.; Franck, Christian

2014-01-01

Native cell-material interactions occur on materials differing in their structural composition, chemistry, and physical compliance. While the last two decades have shown the importance of traction forces during cell-material interactions, they have been almost exclusively presented on purely elastic in-vitro materials. Yet, most bodily tissue materials exhibit some level of viscoelasticity, which could play an important role in how cells sense and transduce tractions. To expand the realm of cell traction measurements and to encompass all materials from elastic to viscoelastic, this paper presents a general, and comprehensive approach for quantifying 3D cell tractions in viscoelastic materials. This methodology includes the experimental characterization of the time-dependent material properties for any viscoelastic material with the subsequent mathematical implementation of the determined material model into a 3D traction force microscopy (3D TFM) framework. Utilizing this new 3D viscoelastic TFM (3D VTFM) approach, we quantify the influence of viscosity on the overall material traction calculations and quantify the error associated with omitting time-dependent material effects, as is the case for all other TFM formulations. We anticipate that the 3D VTFM technique will open up new avenues of cell-material investigations on even more physiologically relevant time-dependent materials including collagen and fibrin gels. PMID:25170569

Control Demonstration of Multiple Doubly-Fed Induction Motors for Hybrid Electric Propulsion

NASA Technical Reports Server (NTRS)

Sadey, David J.; Bodson, Marc; Csank, Jeffrey T.; Hunker, Keith R.; Theman, Casey J.; Taylor, Linda M.

2017-01-01

The Convergent Aeronautics Solutions (CAS) High Voltage-Hybrid Electric Propulsion (HVHEP) task was formulated to support the move into future hybrid-electric aircraft. The goal of this project is to develop a new AC power architecture to support the needs of higher efficiency and lower emissions. This proposed architecture will adopt the use of the doubly-fed induction machine (DFIM) for propulsor drive motor application.The Convergent Aeronautics Solutions (CAS) High Voltage-Hybrid Electric Propulsion (HVHEP) task was formulated to support the move into future hybrid-electric aircraft. The goal of this project is to develop a new AC power architecture to support the needs of higher efficiency and lower emissions. This proposed architecture will adopt the use of the doubly-fed induction machine (DFIM) for propulsor drive motor application. DFIMs are attractive for several reasons, including but not limited to the ability to self-start, ability to operate sub- and super-synchronously, and requiring only fractionally rated power converters on a per-unit basis depending on the required range of operation. The focus of this paper is based specifically on the presentation and analysis of a novel strategy which allows for independent operation of each of the aforementioned doubly-fed induction motors. This strategy includes synchronization, soft-start, and closed loop speed control of each motor as a means of controlling output thrust; be it concurrently or differentially. The demonstration of this strategy has recently been proven out on a low power test bed using fractional horsepower machines. Simulation and hardware test results are presented in the paper.

Analytical Model and Optimized Design of Power Transmitting Coil for Inductively Coupled Endoscope Robot.

PubMed

Ke, Quan; Luo, Weijie; Yan, Guozheng; Yang, Kai

2016-04-01

A wireless power transfer system based on the weakly inductive coupling makes it possible to provide the endoscope microrobot (EMR) with infinite power. To facilitate the patients' inspection with the EMR system, the diameter of the transmitting coil is enlarged to 69 cm. Due to the large transmitting range, a high quality factor of the Litz-wire transmitting coil is a necessity to ensure the intensity of magnetic field generated efficiently. Thus, this paper builds an analytical model of the transmitting coil, and then, optimizes the parameters of the coil by enlarging the quality factor. The lumped model of the transmitting coil includes three parameters: ac resistance, self-inductance, and stray capacitance. Based on the exact two-dimension solution, the accurate analytical expression of ac resistance is derived. Several transmitting coils of different specifications are utilized to verify this analytical expression, being in good agreements with the measured results except the coils with a large number of strands. Then, the quality factor of transmitting coils can be well predicted with the available analytical expressions of self- inductance and stray capacitance. Owing to the exact estimation of quality factor, the appropriate coil turns of the transmitting coil is set to 18-40 within the restrictions of transmitting circuit and human tissue issues. To supply enough energy for the next generation of the EMR equipped with a Ø9.5×10.1 mm receiving coil, the coil turns of the transmitting coil is optimally set to 28, which can transfer a maximum power of 750 mW with the remarkable delivering efficiency of 3.55%.

Vinpocetine inhibits Streptococcus pneumoniae-induced upregulation of mucin MUC5AC expression via induction of MKP-1 phosphatase in the pathogenesis of otitis media.

PubMed

Lee, Ji-Yun; Komatsu, Kensei; Lee, Byung-Cheol; Miyata, Masanori; O'Neill Bohn, Ashley; Xu, Haidong; Yan, Chen; Li, Jian-Dong

2015-06-15

Mucin overproduction is a hallmark of otitis media (OM). Streptococcus pneumoniae is one of the most common bacterial pathogens causing OM. Mucin MUC5AC plays an important role in mucociliary clearance of bacterial pathogens. However, if uncontrolled, excessive mucus contributes significantly to conductive hearing loss. Currently, there is a lack of effective therapeutic agents that suppress mucus overproduction. In this study, we show that a currently existing antistroke drug, vinpocetine, a derivative of the alkaloid vincamine, inhibited S. pneumoniae-induced mucin MUC5AC upregulation in cultured middle ear epithelial cells and in the middle ear of mice. Moreover, vinpocetine inhibited MUC5AC upregulation by inhibiting the MAPK ERK pathway in an MKP-1-dependent manner. Importantly, ototopical administration of vinpocetine postinfection inhibited MUC5AC expression and middle ear inflammation induced by S. pneumoniae and reduced hearing loss and pneumococcal loads in a well-established mouse model of OM. Thus, these studies identified vinpocetine as a potential therapeutic agent for inhibiting mucus production in the pathogenesis of OM. Copyright © 2015 by The American Association of Immunologists, Inc.

B cells as accessory cells in a Con A response of a T cell clone.

PubMed

Takeuchi, M; Kakiuchi, T; Taira, S; Nariuchi, H

1987-12-01

Accessory cell (AC) function of B cells was examined in Con A response of a cloned T cell line, 22-9D, which is Thy 1+,L3T4+,Lyt2-,H-2KbDb+ and I-Ab-.22-9D cells produced IL 2 in the presence of Con A without participation of AC. For the initiation of a proliferative response to Con A, the addition of spleen cells or spleen adherent cells was required. B cells as AC were unable to induce the proliferative response. In the presence of culture supernatant of spleen cells stimulated with Con A (CAS), 22-9D cells showed proliferative response to Con A with B cell AC. The response was inhibited by a relevant monoclonal anti-I-A antibody. Although irradiated spleen cells as AC induced IL 2 receptor expression of 22-9D cells in the presence of Con A, B cells were shown to require the addition of unknown factor(s) in CAS, which was suggested to be different from IL 1, IL 2, IL 3, or IFN-gamma, for the induction of the receptor expression on 22-9D cells.

Traction force dynamics predict gap formation in activated endothelium

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

Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van

In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneousmore » distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.« less

Power transmission cable development for the Space Station Freedom electrical power system

NASA Technical Reports Server (NTRS)

Schmitz, Gregory V.; Biess, John J.

1989-01-01

Power transmission cable is presently being evaluated under a NASA Lewis Research Center advanced development contract for application in the Space Station Freedom (SSF) electrical power system (EPS). Evaluation testing has been performed by TRW and NASA Lewis Research Center. The results of this development contract are presented. The primary cable design goals are to provide (1) a low characteristic inductance to minimize line voltage drop at 20 kHz, (2) electromagnetic compatibility control of the 20-kHz ac power current, (3) a physical configuration that minimizes ac resistance and (4) release of trapped air for corona-free operation.

Age-related differences in the response of the L5-S1 intervertebral disc to spinal traction.

PubMed

Mitchell, Ulrike H; Beattie, Paul F; Bowden, Jennifer; Larson, Robert; Wang, Haonan

2017-10-01

Lumbar traction is a common treatment for low back pain; however its mechanisms of action are poorly understood. It has been hypothesized that a key effect of lumbar traction is its capacity to influence fluid movement within the intervertebral disc (IVD). To determine differences in the apparent diffusion coefficient (ADC) obtained with lumbar diffusion-weighted imaging (DWI) of the L5-S1 IVD before, and during, the application of lumbar traction. Case series, repeated measures. A static traction load of ∼50% of body-weight was applied to the low back using a novel "MRI-safe" apparatus. DWI of the lumbar spine was performed prior to, and during the application of the traction load. Participants were currently asymptomatic and included a young adult group (n = 18) and a middle-aged group (n = 15). The young adult group had a non-significant 2.2% increase in ADC (mean change = 0.03 × 10 -3  mm 2 /s, SD = 0.24, 95% CI = -0.09, 0.15). The ADC for the middle-aged group significantly increased by 20% (mean change of 0.18 × 10 -3  mm 2 /s, SD = 0.19; 95% CI = 0.07, 0.28; p = 0.003; effect size = 0.95). There was an inverse relationship between the ADC obtained before traction and the percent increase in ADC that was measured during traction. Static traction was associated with an increase in diffusion of water within the L5-S1 IVDs of middle-age individuals, but not in young adults, suggesting age-related differences in the diffusion response. Further study is needed to assess the relationship between these findings and the symptoms of back pain. 4. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modification of the SHABERTH bearing code to incorporate RP-1 and a discussion of the traction model

NASA Technical Reports Server (NTRS)

Woods, Claudia M.

1990-01-01

Recently developed traction data for Rocket Propellant 1 (RP-1), a hydrocarbon fuel of the kerosene family, was used to develop the parameters needed by the bearing code SHABERTH in order to include RP-1 as a lubricant choice. The procedure for inputting data for a new lubricant choice is reviewed, and the theoretical fluid traction model is discussed. Comparisons are made between experimental traction data and those predicted by SHABERTH for RP-1. All data needed to modify SHABERTH for use with RP-1 as a lubricant are specified.

Insights on Structure and Function of a Late Embryogenesis Abundant Protein from Amaranthus cruentus: An Intrinsically Disordered Protein Involved in Protection against Desiccation, Oxidant Conditions, and Osmotic Stress

PubMed Central

Saucedo, Alma L.; Hernández-Domínguez, Eric E.; de Luna-Valdez, Luis A.; Guevara-García, Angel A.; Escobedo-Moratilla, Abraham; Bojorquéz-Velázquez, Esaú; del Río-Portilla, Federico; Fernández-Velasco, Daniel A.; Barba de la Rosa, Ana P.

2017-01-01

Late embryogenesis abundant (LEA) proteins are part of a large protein family that protect other proteins from aggregation due to desiccation or osmotic stresses. Recently, the Amaranthus cruentus seed proteome was characterized by 2D-PAGE and one highly accumulated protein spot was identified as a LEA protein and was named AcLEA. In this work, AcLEA cDNA was cloned into an expression vector and the recombinant protein was purified and characterized. AcLEA encodes a 172 amino acid polypeptide with a predicted molecular mass of 18.34 kDa and estimated pI of 8.58. Phylogenetic analysis revealed that AcLEA is evolutionarily close to the LEA3 group. Structural characteristics were revealed by nuclear magnetic resonance and circular dichroism methods. We have shown that recombinant AcLEA is an intrinsically disordered protein in solution even at high salinity and osmotic pressures, but it has a strong tendency to take a secondary structure, mainly folded as α-helix, when an inductive additive is present. Recombinant AcLEA function was evaluated using Escherichia coli as in vivo model showing the important protection role against desiccation, oxidant conditions, and osmotic stress. AcLEA recombinant protein was localized in cytoplasm of Nicotiana benthamiana protoplasts and orthologs were detected in seeds of wild and domesticated amaranth species. Interestingly AcLEA was detected in leaves, stems, and roots but only in plants subjected to salt stress. This fact could indicate the important role of AcLEA protection during plant stress in all amaranth species studied. PMID:28439280

Experimental studies about the impact of traction sand on urban road dust composition.

PubMed

Kupiainen, Kaarle; Tervahattu, Heikki; Räisänen, Mika

2003-06-01

Traffic causes enhanced PM(10) resuspension especially during spring in the US, Japan, Norway, Sweden and Finland, among other countries. The springtime PM(10) consists primarily of mineral matter from tyre-induced paved road surface wear and traction sand. In some countries, the majority of vehicles are equipped with studded tyres to enhance traction, which additionally increases road surface wear. Because the traction sand and the mineral matter from the pavement aggregate can have a similar mineralogical composition, it has been difficult to determine the source of the mineral fraction in the PM(10). In this study, homogenous traction sand and pavement aggregate with different mineralogical compositions were chosen to determine the sources of PM(10) particles by single particle analysis (SEM/EDX). This study was conducted in a test facility, which made it possible to rule out dust contributions from other sources. The ambient PM(10) concentrations were higher when traction sand was used, regardless of whether the tyres were studded or not. Surprisingly, the use of traction sand greatly increased the number of the particles originating from the pavement. It was concluded that sand must contribute to pavement wear. This phenomenon is called the sandpaper effect. An understanding of this is important to reduce harmful effects of springtime road dust in practical winter maintenance of urban roads

Evaluation of force degradation characteristics of orthodontic latex elastics in vitro and in vivo.

PubMed

Wang, Tong; Zhou, Gang; Tan, Xianfeng; Dong, Yaojun

2007-07-01

To evaluate the characteristics of force degradation of latex elastics in clinical applications and in vitro studies. Samples of 3/16-inch latex elastics were investigated, and 12 students between the ages of 12 and 15 years were selected for the intermaxillary and intramaxillary tractions. The elastics in the control groups were set in artificial saliva and dry room conditions and were stretched 20 mm. The repeated-measure two-way analysis of variance and nonlinear regression analysis were used to identify statistical significance. Overall, there were statistically significant differences between the different methods and observation intervals. At 24- and 48-hour time intervals, the force decreased during in vivo testing and in artificial saliva (P < .001), whereas there were no significant differences in dry room conditions (P > .05). In intermaxillary traction the percentage of initial force remaining after 48 hours was 61%. In intramaxillary traction and in artificial saliva the percentage of initial force remaining was 71%, and in room conditions 86% of initial force remained. Force degradation of latex elastics was different according to their environmental conditions. There was significantly more force degradation in intermaxillary traction than in intramaxillary traction. The dry room condition caused the least force loss. There were some differences among groups in the different times to start wearing elastics in intermaxillary traction but no significant differences in intramaxillary traction.

Comparison of Short-Term Effects of Diquafosol and Rebamipide on Mucin 5AC Level on the Rabbit Ocular Surface.

PubMed

Hori, Yuichi; Kageyama, Tomofumi; Sakamoto, Asuka; Shiba, Tomoaki; Nakamura, Masatsugu; Maeno, Takatoshi

To investigate the short-term effects of 2 new secretagogue eye drops for dry eye, 3% diquafosol tetrasodium ophthalmic solution (diquafosol) and 2% rebamipide ophthalmic suspension (rebamipide), on the concentration of mucin 5AC (MUC5AC) in rabbit tear fluid and conjunctival goblet cells. One dose of artificial tears, diquafosol or rebamipide, was instilled into 8 eyes of Japanese white rabbits. MUC5AC concentration in the tear fluid was examined using the enzyme-linked immunosorbent assay 15 min after instillation and compared with 8 untreated controls. Impression cytology was performed to measure the number of periodic acid Schiff (PAS)-positive cells and the ratio of the PAS-positive area using image analysis software. Statistical comparison was performed using ANOVA with post hoc analysis with the Tukey's test. After 15 min, only diquafosol significantly (P ≤ 0.01) increased the MUC5AC level in the tear fluid. Although no drug affected the number of PAS-positive cells, the ratio of the PAS-positive area decreased significantly (P ≤ 0.01) only in the diquafosol group. These data indicated that more PAS-positive MUC5AC was released into the tear fluid from the goblet cells by diquafosol than by rebamipide. There is a difference in the induction pattern of MUC5AC into the tears from the goblet cells between these eye drops.

Applications of Traction Force Microscopy in Measuring Adhesion Molecule Dependent Cell Contractility

ERIC Educational Resources Information Center

Mann, Cynthia Marie

2009-01-01

This work describes the use of polyacrylamide hydrogels as controlled elastic modulus substrates for single cell traction force microscopy studies. The first section describes the use of EDC/NHS chemistry to convalently link microbeads to the hydrogel matrix for the purpose of performing long-term traction force studies (7 days). The final study…

I-BIEM calculations of the frequency dispersion and ac current distribution at disk and ring-disk electrodes

NASA Technical Reports Server (NTRS)

Cahan, Boris D.

1991-01-01

The Iterative Boundary Integral Equation Method (I-BIEM) has been applied to the problem of frequency dispersion at a disk electrode in a finite geometry. The I-BIEM permits the direct evaluation of the AC potential (a complex variable) using complex boundary conditions. The point spacing was made highly nonuniform, to give extremely high resolution in those regions where the variables change most rapidly, i.e., in the vicinity of the edge of the disk. Results are analyzed with respect to IR correction, equipotential surfaces, and reference electrode placement. The current distribution is also examined for a ring-disk configuration, with the ring and the disk at the same AC potential. It is shown that the apparent impedance of the disk is inductive at higher frequencies. The results are compared to analytic calculations from the literature, and usually agree to better than 0.001 percent.

I-BIEM calculations of the frequency dispersion and AC current distribution at disk and ring-disk electrodes

NASA Technical Reports Server (NTRS)

Cahan, Boris D.

1991-01-01

The Iterative Boundary Integral Equation Method (I-BIEM) has been applied to the problem of frequency dispersion at a disk electrode in a finite geometry. The I-BIEM permits the direct evaluation of the AC potential (a complex variable) using complex boundary conditions. The point spacing was made highly nonuniform, to give extremely high resolution in those regions where the variables change most rapidly, i.e., in the vicinity of the edge of the disk. Results are analyzed with respect to IR correction, equipotential surfaces, and reference electrode placement. The current distribution is also examined for a ring-disk configuration, with the ring and the disk at the same AC potential. It is shown that the apparent impedance of the disk is inductive at higher frequencies. The results are compared to analytic calculations from the literature, and usually agree to better than 0.001 percent.

Effects of p-chlorophenoxyisobutyric acid, arabinogalactan, and activated charcoal on microspore embryogenesis in kale.

PubMed

Niu, R Q; Zhang, Y; Tong, Y; Liu, Z Y; Wang, Y H; Feng, H

2015-04-27

To improve embryogenesis in microspore cultures of kale (Brassica oleracea L. var. acephala DC.), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA), arabinogalactan (AG), p-chlorophenoxyisobutyric acid (PCIB), and activated charcoal (AC) were added to the medium using four varieties of kale. The results showed that the addition of AG (0.1-0.2 g/L), AC (0.1-0.2 g/L) or a combination of 6-BA (0.1-0.2 mg/L) and NAA (0.1-0.2 mg/L) promoted embryo-genesis. Adding 40 μM PCIB or a combination of 40 μM PCIB and 0.2 g/L AC to NLN-13 medium at pH 5.8 effectively enhanced embryogenesis. Treatment with a combination of 40 μM PCIB and 10 mg/L AG gave the highest rate of embryonic induction, especially in genotype "Y007," which showed a twelve-fold increase in yield.

PWM Inverter control and the application thereof within electric vehicles

DOEpatents

Geppert, Steven

1982-01-01

An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

Akt-mTORC1 signaling regulates Acly to integrate metabolic input to control of macrophage activation

PubMed Central

Covarrubias, Anthony J; Aksoylar, Halil Ibrahim; Yu, Jiujiu; Snyder, Nathaniel W; Worth, Andrew J; Iyer, Shankar S; Wang, Jiawei; Ben-Sahra, Issam; Byles, Vanessa; Polynne-Stapornkul, Tiffany; Espinosa, Erika C; Lamming, Dudley; Manning, Brendan D; Zhang, Yijing; Blair, Ian A; Horng, Tiffany

2016-01-01

Macrophage activation/polarization to distinct functional states is critically supported by metabolic shifts. How polarizing signals coordinate metabolic and functional reprogramming, and the potential implications for control of macrophage activation, remains poorly understood. Here we show that IL-4 signaling co-opts the Akt-mTORC1 pathway to regulate Acly, a key enzyme in Ac-CoA synthesis, leading to increased histone acetylation and M2 gene induction. Only a subset of M2 genes is controlled in this way, including those regulating cellular proliferation and chemokine production. Moreover, metabolic signals impinge on the Akt-mTORC1 axis for such control of M2 activation. We propose that Akt-mTORC1 signaling calibrates metabolic state to energetically demanding aspects of M2 activation, which may define a new role for metabolism in supporting macrophage activation. DOI: http://dx.doi.org/10.7554/eLife.11612.001 PMID:26894960

EV drivetrain inverter with V/HZ optimization

DOEpatents

Gritter, David J.; O'Neil, Walter K.

1986-01-01

An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer which calculates optimized machine control data signals from various parametric inputs and during steady state load conditions, seeks a best V/HZ ratio to minimize battery current drawn (system losses) from a D.C. power source (32). In the preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack and a three-phase induction motor (18).

Comparison between effectiveness of Mechanical and Manual Traction combined with mobilization and exercise therapy in Patients with Cervical Radiculopathy.

PubMed

Bukhari, Syed Rehan Iftikhar; Shakil-Ur-Rehman, Syed; Ahmad, Shakeel; Naeem, Aamer

2016-01-01

Cervical radiculopathy is a common neuro-musculo-skeletal disorder causing pain and disability. Traction is part of the evidence based manual physical therapy management due to its mechanical nature, type of traction and parameters related to its applicability and are still to be explored more through research. Our objective was to determine the Effects of Mechanical versus Manual Traction in Manual Physical Therapy combined with segmental mobilization and exercise therapy in the physical therapy management of Patients with Cervical Radiculopathy. This randomized control trial was conducted at department of physical therapy and rehabilitation, Rathore Hospital Faisalabad, from February to July 2015. Inclusion criteria were both male and female patients with evident symptoms of cervical spine radiculopathy and age ranged between 20-70 years. The exclusion criteria were Patients with history of trauma, neck pain without radiculopathy, aged less than 20 and more than 70. A total of 72 patients with cervical radiculopathy were screened out as per the inclusion criteria, 42 patients were randomly selected and placed into two groups by toss and trial method, and only 36 patients completed the study, while 6 dropped out. The mechanical traction was applied in group A and manual traction in group B along with common intervention of segmental mobilization and exercise therapy in both groups for 6 weeks. The patient's outcomes were assessed by self reported NPRS and NDI at the baseline and after completion of 06 weeks exercise program at 3 days per week. The data was analyzed through SPSS version-21, and paired T test was applied at 95% level significance to determine the statistical deference between two groups. Clinically the group of patients treated with mechanical traction managed pain (mean pre 6.26, mean post 1.43), and disability (mean pre 24.43 and mean post 7.26) more effectively as compared with the group of patients treated with manual traction (Pain mean pre 6.80, mean post 3.85 and disability mean pre 21.92 and post 12.19). Statistically the results of both mechanical and manual traction techniques are equally significant in group A and B for pain and disability (p-value less than 0.05). If patients of cervical radiculopathy treated with mechanical traction, segmental mobilization, and exercise therapy will manage pain and disability more effectively than treated with manual traction, segmental mobilization, and exercise therapy.

Footwear traction and three-dimensional kinematics of level, downhill, uphill and cross-slope walking.

PubMed

Wannop, John W; Worobets, Jay T; Ruiz, Rodrigo; Stefanyshyn, Darren J

2014-01-01

Outdoor activities are a popular form of recreation, with hiking being the most popular outdoor activity as well as being the most prevalent in terms of injury. Over the duration of a hike, trekkers will encounter many different sloped terrains. Not much is known about the required traction or foot-floor kinematics during locomotion on these sloped surfaces, therefore, the purpose was to determine the three-dimensional foot-floor kinematics and required traction during level, downhill, uphill and cross-slope walking. Ten participants performed level, uphill, downhill and cross-slope walking along a 19° inclined walkway. Ground reaction force data as well as 3D positions of retro reflective markers attached to the shoe were recorded using a Motion Analysis System. Peak traction coefficients and foot-floor kinematics during sloped walking were compared to level walking. When walking along different sloped surfaces, the required traction coefficients at touchdown were not different from level walking, therefore, the increased likelihood of heel slipping during hiking is potentially due to the presence of loose material (rocks, dirt) on hiking slopes, rather than the overall lack of traction. Differences in required traction were seen at takeoff, with uphill and cross-sloped walking requiring a greater amount of traction compared to level walking. Changes in sagittal plane, frontal plane and transverse plane foot-floor angles were seen while walking on the sloped surfaces. Rapid foot-floor eversion was observed during cross-slope walking which could place the hiker at risk of injury with a misstep or if there was a slight slip. Copyright © 2014 Elsevier B.V. All rights reserved.

Asymmetry of activation of lateral abdominal muscles during the neurodevelopmental traction technique.

PubMed

Gogola, Anna; Gnat, Rafał; Zaborowska, Małgorzata; Dziub, Dorota; Gwóźdź, Michalina

2018-01-01

The aim of the study was to evaluate the symmetry and pattern of activation of lateral abdominal muscles (LAM) in response to neurodevelopmental traction technique. Measurements of LAM thickness were performed in four experimental conditions: during traction with the force of 5% body weight (5% traction): 1) in neutral position, 2) in 20° posterior trunk inclination; during traction with the force of 15% body weight (15% traction): 3) in neutral position, 4) in 20° posterior trunk inclination. Thirty-seven healthy children participated in the study. Not applicable. To evaluate LAM activation level ultrasound technology was employed (two Mindray DP660 devices (Mindray, Shenzhen, China) with 75L38EA linear probes). An experiment with repeated measurements of the dependent variables was conducted. Side-to-side LAM activation asymmetry showed relatively high magnitude, however, significant difference was found only in case of the obliquus externus (OE) during stronger traction (P < 0.05). The magnitude of LAM thickness change formed a gradient, with the most profound transversus abdominis (TrA) showing the smallest change, and the most superficial OE - the greatest. The inter-muscle differences were most pronounced between the OE and TrA (P < 0.001). During the neurodevelopmental traction technique there is a difference in individual LAM activation level, with deeper muscles showing less intense activation. In statistical terms, the only signs of side-to-side asymmetry of LAM activation are visible in case of the OE, however, the magnitude of asymmetry is relatively high. The results allow to identify patterns of activation of LAM in children showing typical development that will serve as a reference in future studies in children with neurological disorder. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biomechanical analysis of combining head-down tilt traction with vibration for different grades of degeneration of the lumbar spine.

PubMed

Wang, Sicong; Wang, Lizhen; Wang, Yawei; Du, Chengfei; Zhang, Ming; Fan, Yubo

2017-01-01

In recent years, a combination of traction and vibration therapy is usually used to alleviate low back pain (LBP) in clinical settings. Combining head-down tilt (HDT) traction with vibration was demonstrated to be efficacious for LBP patients in our previous study. However, the biomechanics of the lumbar spine during this combined treatment is not well known and need quantitative analysis. In addition, LBP patients have different grades of degeneration of the lumbar spinal structure, which are often age related. Selecting a suitable rehabilitation therapy for different age groups of patients has been challenging. Therefore, a finite element (FE) model of the L1-L5 lumbar spine and a vibration dynamic model are developed in this study in order to investigate the biomechanical effects of the combination of HDT traction and vibration therapy on the age-related degeneration of the lumbar spine. The decrease of intradiscal pressure is more effective when vibration is combined with traction therapy. Moreover, the stresses on the discs are lower in the "traction+vibration" mode than the "traction-only" mode. The stress concentration at the posterior part of nucleus is mitigated after the vibration is combined. The disc deformations especially posterior disc radial retraction is improved in the "traction+vibration" mode. These beneficial effects of this therapy could help decompress the discs and spinal nerves and therefore relieve LBP. Simultaneously, patients with grade 1 degeneration (approximately 41-50 years old) are able to achieve better results compared with other age groups. This study could be used to provide a more effective LBP rehabilitation therapy. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Traction and film thickness measurements under starved elastohydrodynamic conditions

NASA Technical Reports Server (NTRS)

Wedeven, L. D.

1974-01-01

Traction measurements under starved elastohydrodynamic conditions were obtained for a point contact geometry. Simultaneous measurements of the film thickness and the locations of the inlet lubricant boundary were made optically. The thickness of a starved film for combination rolling and sliding conditions varies with the location of the inlet boundary in the same way found previously for pure rolling. A starved film was observed to possess greater traction than a flooded film for the same slide roll ratio. For a given slide roll ratio a starved film simply increases the shear rate in the Hertz region. The maximum shear rate depends on the degree of starvation and has no theoretical limit. Traction measurements under starved conditions were compared with flooded conditions under equivalent shear rates in the Hertz region. When the shear rates in the Hertz region were low and the film severely starved, the measured tractions were found to be much lower than expected.

Numerical minimization of AC losses in coaxial coated conductor cables

NASA Astrophysics Data System (ADS)

Rostila, L.; Suuriniemi, S.; Lehtonen, J.; Grasso, G.

2010-02-01

Power cables are one of the most promising applications for the superconducting coated conductors. In the AC use, only small resistive loss is generated, but the removal of the dissipated heat from the cryostat is inefficient due to the large temperature difference. The aim of this work is to minimize the AC losses in a multilayer coaxial cable, in which the tapes form current carrying cylinders. The optimized parameters are the tape numbers and lay angles in these cylinders. This work shows how to cope with the mechanical constraints for the lay angles and discrete tape number in optimization. Three common types of coaxial cables are studied here to demonstrate the feasibility of optimization, in which the AC losses were computed with a circuit analysis model formulated here for arbitrary phase currents, number of phases, and layers. Because the current sharing is practically determined by the inductances of the layers, the optima were obtained much faster by neglecting the nonlinear resistances caused by the AC losses. In addition, the example calculations show that the optimal cable structure do not usually depend on the AC loss model for the individual tapes. On the other hand, depending on the cable type, the losses of the optimized cables may be sensitive to the lay angles, and therefore, we recommend to study the sensitivity for the new cable designs individually.

Focal Thalamic Degeneration from Ethanol and Thiamine Deficiency is Associated with Neuroimmune Gene Induction, Microglial Activation, and Lack of Monocarboxylic Acid Transporters

PubMed Central

Qin, Liya; Crews, Fulton T

2014-01-01

Background Wernicke's encephalopathy-Korsakoff syndrome (WE-KS) is common in alcoholics, caused by thiamine deficiency (TD; vitamin B1) and associated with lesions to the thalamus (THAL). Although TD alone can cause WE, the high incidence in alcoholism suggests that TD and ethanol (EtOH) interact. Methods Mice in control, TD, or EtOH groups alone or combined were studied after 5 or 10 days of treatment. THAL and entorhinal cortex (ENT) histochemistry and mRNA were assessed. Results Combined EtOH-TD treatment for 5 days (EtOH-TD5) showed activated microglia, proinflammatory gene induction and THAL neurodegeneration that was greater than that found with TD alone (TD5), whereas 10 days resulted in marked THAL degeneration and microglial-neuroimmune activation in both groups. In contrast, 10 days of TD did not cause ENT degeneration. Interestingly, in ENT, TD10 activated microglia and astrocytes more than EtOH-TD10. In THAL, multiple astrocytic markers were lost consistent with glial cell loss. TD blocks glucose metabolism more than acetate. Acetate derived from hepatic EtOH metabolism is transported by monocarboxylic acid transporters (MCT) into both neurons and astrocytes that use acetyl-CoA synthetase (AcCoAS) to generate cellular energy from acetate. MCT and AcCoAS expression in THAL is lower than ENT prompting the hypothesis that focal THAL degeneration is related to insufficient MCT and AcCoAS in THAL. To test this hypothesis, we administered glycerin triacetate (GTA) to increase blood acetate and found it protected the THAL from TD-induced degeneration. Conclusions Our findings suggest that EtOH potentiates TD-induced THAL degeneration through neuroimmune gene induction. The findings support the hypothesis that TD deficiency inhibits global glucose metabolism and that a reduced ability to process acetate for cellular energy results in THAL focal degeneration in alcoholics contributing to the high incidence of Wernicke-Korsakoff syndrome in alcoholism. PMID:24117525

70. DETAIL OF TRACTION CABLE ENGAGEMENT DEVICE. SMALL, KNOBBED LEVER ...

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

70. DETAIL OF TRACTION CABLE ENGAGEMENT DEVICE. SMALL, KNOBBED LEVER ON BUCKET HANGER WAS PULLED DOWN BY A CAMEL (FIXED CAM RAIL AT CENTER) AS BUCKET ROLLED PAST IT, CAUSING A CLAMP TO CLOSE AGAINST TRACTION CABLE. A SIMILAR CAMEL (NO LONGER EXTANT) DISENGAGED CLAMP ON RECEIVING SIDE. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

Traction free finite elements with the assumed stress hybrid model. M.S. Thesis, 1981

NASA Technical Reports Server (NTRS)

Kafie, Kurosh

1991-01-01

An effective approach in the finite element analysis of the stress field at the traction free boundary of a solid continuum was studied. Conventional displacement and assumed stress finite elements were used in the determination of stress concentrations around circular and elliptical holes. Specialized hybrid elements were then developed to improve the satisfaction of prescribed traction boundary conditions. Results of the stress analysis indicated that finite elements which exactly satisfy the free stress boundary conditions are the most accurate and efficient in such problems. A general approach for hybrid finite elements which incorporate traction free boundaries of arbitrary geometry was formulated.

Targeted traction of impacted teeth with C-tube miniplates.

PubMed

Chung, Kyu-Rhim; Kim, Yong; Ahn, Hyo-Won; Lee, Dongjoo; Yang, Dong-Min; Kim, Seong-Hun; Nelson, Gerald

2014-09-01

Orthodontic traction of impacted teeth has typically been performed using full fixed appliance as anchorage against the traction force. This conventional approach can be difficult to apply in the mixed dentition if the partial fixed appliance offers an insufficient anchor unit. In addition, full fixed appliance can induce unwanted movement of adjacent teeth. This clinical report presents 3 cases where impacted teeth were recovered in the mixed or transitional dentition with skeletal anchorage on the opposite arch without full fixed appliance. Instead, intermaxillary traction was used to bring the impacted teeth into position. With this approach, side effects on teeth and periodontal tissues adjacent to the impaction were minimized.

Surgical management of retinal diseases: proliferative diabetic retinopathy and traction retinal detachment.

PubMed

Cruz-Iñigo, Yousef J; Acabá, Luis A; Berrocal, Maria H

2014-01-01

Current indications for pars plana vitrectomy in patients with proliferative diabetic retinopathy (PDR) include vitreous hemorrhage, tractional retinal detachment (TRD), combined tractional and rhegmatogenous retinal detachment (CTRRD), diabetic macular edema associated with posterior hyaloidal traction, and anterior segment neovascularization with media opacities. This chapter will review the indications, surgical objectives, adjunctive pharmacotherapy, microincision surgical techniques, and outcomes of diabetic vitrectomy for PDR, TRD, and CTRRD. With the availability of new microincision vitrectomy technology, wide-angle microscope viewing systems, and pharmacologic agents, vitrectomy can improve visual acuity and achieve long-term anatomic stability in eyes with severe complications from PDR. © 2014 S. Karger AG, Basel

The results of preoperative halo-gravity traction in children with severe spinal deformity.

PubMed

Garabekyan, Tigran; Hosseinzadeh, Pooya; Iwinski, Henry J; Muchow, Ryan D; Talwalkar, Vishwas R; Walker, Janet; Milbrandt, Todd A

2014-01-01

Halo-gravity traction has been used preoperatively for patients with severe spinal deformity but there are limited data in the literature on the results and complications. We studied the outcomes of perioperative halo-gravity traction in children with severe spinal deformity. A retrospective study was carried out on patients who were treated at our center. Twenty-one patients were included in the study. Radiographic and pulmonary function parameters showed significant improvement during the course of traction and at the final follow-up. The overall complication rate was 19%, including two patients with pin loosening and two patients with superficial pin-site infections treated with oral antibiotics.

Development of a measurement system for the mechanical load of functional appliances.

PubMed

Shimazaki, Aya; Kimura, Hitoshi; Inou, Norio; Maki, Koutaro

2017-10-03

Devices called functional appliances are commonly used in orthodontics for treating maxillary protrusion. These devices mechanically force the mandible forward to apply traction force to the mandibular condyle. This promotes cartilaginous growth in the small mandible. However, no studies have clarified how much traction force is applied to the mandibular condyle. Moreover, it remains unknown as to how anatomical characteristics affect this traction force. Therefore, in this study, we developed a device for measuring the amount of force generated while individual patients wore functional appliances, and we investigated the relationship between forces with structures surrounding the mandibular condyle. We compared traction force values with cone-beam computed tomography image data in eight subjects. The functional appliance resulted in a traction force of 339-1477gf/mm, with a mean value of 196.5gf/mm for the elastic modulus of the mandible. A comparison with cone-beam computed tomography image data suggested that the mandibular traction force was affected by the mandibular condyle and shape of the articular eminence. This method can contribute to discovering efficient treatment techniques more suited to individual patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ventriculoperitoneal Shunt Fracture Following Application of Halo-Gravity Traction: A Case Report.

PubMed

Blakeney, William G; D'Amato, Charles

2015-09-01

Ventriculoperitoneal (VP) shunt malfunctions are very common, and shunt fracture is one of the most common causes. Shunt fractures are often a result of calcification and tethering, which predispose the tubing to fracture when mechanical stresses are applied. This case report describes a case of shunt fracture following application of halo-gravity traction for correction of spinal deformity. Chart and imaging data for a single case were reviewed and reported in this retrospective case study. A 10-year-old female, being treated for syndromic scoliosis, underwent posterior surgical release and application of halo-gravity traction. Increasing weight of traction was applied over a period of 6 weeks, for gradual deformity correction. It was noted on the 6-week cervical spine radiograph that the VP shunt had fractured at the base of the neck. The patient was taken to the operating room and intraoperative findings confirmed shunt fracture. This was repaired without complications. This case, to our best knowledge, is the first reported occurrence of shunt fracture following application of halo-gravity traction. It demonstrates the importance of careful monitoring of patients with VP shunts, when they are undergoing traction for correction of spinal deformity. Level IV.

The application of a clinical prediction rule for patients with neck pain likely to benefit from cervical traction: A case report.

PubMed

Bernstetter, Andrew

2016-10-01

Cervical traction is a commonly utilized intervention in the treatment of patients with neck pain. In 2009, a clinical prediction rule (CPR) was developed as a way to assist clinicians in determining the patient population most likely to respond to cervical traction, though this CPR has yet to be validated. The purpose of this case report is to demonstrate the application of that CPR. The patient was a 46-year-old female with a four-week history of right-sided neck and shoulder pain, with numbness and tingling of her thumb and index finger. Treatment consisted of five sessions provided over 3 weeks. The plan of care included home mechanical cervical traction, exercise, and manual therapy. The patient achieved pain-free cervical range of motion. Neck disability index scores decreased from 28% to 6%, and the Patient-Specific Functional Scale average score improved from 5.5 to 10 out of 10. This case report demonstrates the application of a CPR to assist in deciding if cervical traction is an appropriate intervention. Further research is needed to validate the CPR and to establish the optimal mode of delivery for traction.

Severe Postoperative Complications may be Related to Mesenteric Traction Syndrome during Open Esophagectomy.

PubMed

Ambrus, R; Svendsen, L B; Secher, N H; Goetze, J P; Rünitz, K; Achiam, M P

2017-09-01

During abdominal surgery, traction of the mesenterium provokes mesenteric traction syndrome, including hypotension, tachycardia, and flushing, along with an increase in plasma prostacyclin (PGI 2 ). We evaluated whether postoperative complications are related to mesenteric traction syndrome during esophagectomy. Flushing, hemodynamic variables, and plasma 6-keto-PGF 1α were recorded during the abdominal part of open ( n = 25) and robotically assisted ( n = 25) esophagectomy. Postoperative complications were also registered, according to the Clavien-Dindo classification. Flushing appeared in 17 (open) and 5 (robotically assisted) surgical cases ( p = 0.001). Mean arterial pressure was stable during both types of surgeries, but infusion of vasopressors during the first hour of open surgery was related to development of widespread (Grade II) flushing ( p = 0.036). For patients who developed flushing, heart rate and plasma 6-keto-PGF 1α also increased ( p = 0.001 and p < 0.001, respectively). Furthermore, severe postoperative complications were related to Grade II flushing ( p = 0.037). Mesenteric traction syndrome manifests more frequently during open than robotically assisted esophagectomy, and postoperative complications appear to be associated with severe mesenteric traction syndrome.

Investigation of efficiency of electric drive control system of excavator traction mechanism based on feedback on load

NASA Astrophysics Data System (ADS)

Kuznetsov, N. K.; Iov, I. A.; Iov, A. A.

2018-05-01

The article presents the results of a study of the efficiency of the electric drive control system of the traction mechanism of a dragline based on the use of feedback on load in the traction cable. The investigations were carried out using a refined electromechanical model of the traction mechanism, which took into account not only the elastic elements of the gearbox, the backlashes in it and the changes in the kinematic parameters of the mechanism during operation, but also the mechanical characteristics of the electric drive and the features of its control system. By mathematical modeling of the transient processes of the electromechanical system, it is shown that the introduction of feedback on the load in the elastic element allows one to reduce the dynamic loads in the traction mechanism and to limit the elastic oscillations of the actuating mechanism in comparison with the standard control system. Fixed as a general decrease in the dynamic load of the nodes of traction mechanism in the modes of loading and latching of the bucket, and a decrease the operating time of the mechanism at maximum load. At the same time, undesirable phenomena in the operation of the electric drive were also associated with the increase in the recovery time of the steady-state value of the speed of the actuating mechanism under certain operating conditions, which can lead to a decrease in the reliability of the mechanical part and the productivity of the traction mechanism.

Finite element analysis of maxillary incisor displacement during en-masse retraction according to orthodontic mini-implant position

PubMed Central

Song, Jae-Won; Lim, Joong-Ki; Lee, Kee-Joon; Sung, Sang-Jin; Chun, Youn-Sic

2016-01-01

Objective Orthodontic mini-implants (OMI) generate various horizontal and vertical force vectors and moments according to their insertion positions. This study aimed to help select ideal biomechanics during maxillary incisor retraction by varying the length in the anterior retraction hook (ARH) and OMI position. Methods Two extraction models were constructed to analyze the three-dimentional finite element: a first premolar extraction model (Model 1, M1) and a residual 1-mm space post-extraction model (Model 2, M2). The OMI position was set at a height of 8 mm from the arch wire between the second maxillary premolar and the first molar (low OMI traction) or at a 12-mm height in the mesial second maxillary premolar (high OMI traction). Retraction force vectors of 200 g from the ARH (-1, +1, +3, and +6 mm) at low or high OMI traction were resolved into X-, Y-, and Z-axis components. Results In M1 (low and high OMI traction) and M2 (low OMI traction), the maxillary incisor tip was extruded, but the apex was intruded, and the occlusal plane was rotated clockwise. Significant intrusion and counter-clockwise rotation in the occlusal plane were observed under high OMI traction and -1 mm ARH in M2. Conclusions This study observed orthodontic tooth movement according to the OMI position and ARH height, and M2 under high OMI traction with short ARH showed retraction with maxillary incisor intrusion. PMID:27478801

Vehicle non-exhaust emissions from the tyre-road interface - effect of stud properties, traction sanding and resuspension

NASA Astrophysics Data System (ADS)

Kupiainen, Kaarle J.; Pirjola, Liisa

2011-08-01

In Northern cities respirable street dust emission levels (PM 10) are especially high during spring. The spring time dust has been observed to cause health effects as well as discomfort among citizens. Major sources of the dust are the abrasion products from the pavement and traction sand aggregates that are formed due to the motion of the tyre. We studied the formation of respirable abrasion particles in the tyre-road interface due to tyre studs and traction sanding by a mobile laboratory vehicle Sniffer. The measurements were preformed on a test track, where the influence of varying stud weight and stud number per tyre on PM 10 emissions was studied. Studded tyres resulted in higher emission levels than studless tyres especially with speeds 50 km h -1 and higher; however, by using light weight studs, which approximately halves the weight of studs, or by reducing the number of studs per tyre to half, the emission levels decreased by approximately half. Additionally measurements were done with and without traction sand coverage on the pavement of a public road. After traction sanding the emission levels were not affected by tyre type but by formation and suspension of traction sand related dust from the road surface. The emissions after traction sanding decreased as a function of time as passing vehicles' motion shifted the sand grains away from the areas with most tyre-road contact.

Conformational studies of immunodominant myelin basic protein 1-11 analogues using NMR and molecular modeling

NASA Astrophysics Data System (ADS)

Laimou, Despina; Lazoura, Eliada; Troganis, Anastassios N.; Matsoukas, Minos-Timotheos; Deraos, Spyros N.; Katsara, Maria; Matsoukas, John; Apostolopoulos, Vasso; Tselios, Theodore V.

2011-11-01

Τwo dimensional nuclear magnetic resonance studies complimented by molecular dynamics simulations were conducted to investigate the conformation of the immunodominant epitope of acetylated myelin basic protein residues 1-11 (Ac-MBP1-11) and its altered peptide ligands, mutated at position 4 to an alanine (Ac-MBP1-11[4A]) or a tyrosine residue (Ac-MBP1-11[4Y]). Conformational analysis of the three analogues indicated that they adopt an extended conformation in DMSO solution as no long distance NOE connectivities were observed and seem to have a similar conformation when bound to the active site of the major histocompatibility complex (MHC II). The interaction of each peptide with MHC class II I-Au was further investigated in order to explore the molecular mechanism of experimental autoimmune encephalomyelitis induction/inhibition in mice. The present findings indicate that the Gln3 residue, which serves as a T-cell receptor (TCR) contact site in the TCR/peptide/I-Au complex, has a different orientation in the mutated analogues especially in the Ac-MBP1-11[4A] peptide. In particular the side chain of Gln3 is not solvent exposed as for the native Ac-MBP1-11 and it is not available for interaction with the TCR.

Neuronal responses to an asymmetrical alternating current field can mimic those produced by an imposed direct current field in vitro.

PubMed

Pan, Linjie; Cirillo, John; Borgens, Richard Ben

2012-08-01

The remarkable polarity-dependent growth and anatomical organization of neurons in vitro produced by imposed direct current (DC) voltage gradients (electrical fields; Ef) can be mimicked by another type of electrical cue. This is a properly structured asymmetrical alternating current (AC) electrical field (A-ACEf). Here we provide details on the construction of an AC signal generator in which all components of an AC waveform can be individually controlled. We show that 1) conventional symmetrical AC voltage gradients will not induce growth, guidance, or architectural changes in sympathetic neurons. We also provide the first qualitative and quantitative data showing that an asymmetric AC application can indeed mimic the DC response in chick sympathetic neurons and their growing neurites. This shift in orientation and neuronal anatomy requires dieback of some neurites and the extension of others to produce a preferred orientation perpendicular to the gradient of voltage. Our new results may lead to a noninvasive means to modify nerve growth and organization by magnetic inductive coupling at distance. These data also indicate the possibility of a means to mimic DC-dependent release of drugs or other biologically active molecules from electrically sensitive that can be loaded with these chemical cargos. Copyright © 2012 Wiley Periodicals, Inc.

Integral inverter/battery charger for use in electric vehicles

NASA Technical Reports Server (NTRS)

Thimmesch, D.

1983-01-01

The design and test results of a thyristor based inverter/charger are discussed. A battery charger is included integral to the inverter by using a subset of the inverter power circuit components. The resulting charger provides electrical isolation between the vehicle propulsion battery and ac line and is capable of charging a 25 kWh propulsion battery in 8 hours from a 220 volt ac line. The integral charger employs the inverter commutation components at a resonant ac/dc isolated converter rated at 3.6 kW. Charger efficiency and power factor at an output power of 3.6 kW are 86% and 95% respectively. The inverter, when operated with a matching polyphase ac induction motor and nominal 132 volt propulsion battery, can provide a peak shaft power of 34 kW (45 ph) during motoring operation and 45 kW (60 hp) during regeneration. Thyristors are employed for the inverter power switching devices and are arranged in an input-commutated topology. This configuration requires only two thyristors to commutate the six main inverter thyristors. Inverter efficiency during motoring operation at motor shaft speeds above 450 rad/sec (4300 rpm) is 92-94% for output power levels above 11 KW (15 hp). The combined ac inverter/charger package weighs 47 kg (103 lbs).

Placement of Intubating Laryngeal Mask Airway Is Easier than Placement of Laryngeal Tube during Manual In-Line Stabilisation of The Neck

PubMed Central

Komatsu, R.; Nagata, O.; Kamata, K.; Yamagata, K.; Sessler, D.I.; Ozaki, M.

2005-01-01

Summary We compared the usefulness of the laryngeal tube (LT) with the intubating laryngeal mask airway (ILMA) in 51 patients whose necks were stabilised by manual in-line traction. After induction of anaesthesia and neuromuscular block, the LT and ILMA were inserted consecutively in a randomised, crossover design. During pressure-controlled ventilation (20 cmH2O inspiratory pressure), we measured insertion attempts, time to establish positive-pressure ventilation, tidal volume, gastric insufflation, and minimum airway pressure at which gas leaked around the cuff. Data were compared using Wilcoxon signed-rank tests; P<0.05 was considered significant. Insertion was more difficult with the LT (successful at first attempt in 16 patients) than with the ILMA (successful at first attempt in 42 patients, P<0.0001). Time required for insertion was longer for the LT (28 [23–35] sec, median [interquartile range]) than the ILMA (20 [15–25] sec, P=0.0009). Tidal volume was less for the LT (440 [290–670] ml) than the ILMA. (630 [440–750] ml, P=0.013). Minimum airway pressure at which gas leak occurred and incidence of gastric insufflation were similar with two devices. In patients whose necks were stabilised with manual in-line traction, insertion of the ILMA was easier and quicker than insertion of the LT and tidal volume was greater with the ILMA than the LT. PMID:15644005

New propulsion components for electric vehicles

NASA Astrophysics Data System (ADS)

Secunde, R. R.

Improved component technology is described. This includes electronically commutated permanent magnet motors of both drum and disk configurations, an unconventional brush commutated motor, ac induction motors, various controllers, transmissions and complete systems. One or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors. Previously announced in STAR as N83-25982

New propulsion components for electric vehicles

NASA Technical Reports Server (NTRS)

Secunde, R. R.

1983-01-01

Improved component technology is described. This includes electronically commutated permanent magnet motors of both drum and disk configurations, an unconventional brush commutated motor, ac induction motors, various controllers, transmissions and complete systems. One or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors. Previously announced in STAR as N83-25982

Development of Traction Drive Motors for the Toyota Hybrid System

NASA Astrophysics Data System (ADS)

Kamiya, Munehiro

Toyota Motor Corporation developed in 2005 a new hybrid system for a large SUV. This system included the new development of a high-speed traction drive motor achieving a significant increase in power weight ratio. This paper provides an overview of the hybrid system, discusses the characteristics required of a traction drive motor, and presents the technologies employed in the developed motor.

Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

NASA Astrophysics Data System (ADS)

Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman

2016-02-01

Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.

Approximate analytical solution for induction heating of solid cylinders

DOE PAGES

Jankowski, Todd Andrew; Pawley, Norma Helen; Gonzales, Lindsey Michal; ...

2015-10-20

An approximate solution to the mathematical model for induction heating of a solid cylinder in a cylindrical induction coil is presented here. The coupled multiphysics model includes equations describing the electromagnetic field in the heated object, a heat transfer simulation to determine temperature of the heated object, and an AC circuit simulation of the induction heating power supply. A multiple-scale perturbation method is used to solve the multiphysics model. The approximate analytical solution yields simple closed-form expressions for the electromagnetic field and heat generation rate in the solid cylinder, for the equivalent impedance of the associated tank circuit, and formore » the frequency response of a variable frequency power supply driving the tank circuit. The solution developed here is validated by comparing predicted power supply frequency to both experimental measurements and calculated values from finite element analysis for heating of graphite cylinders in an induction furnace. The simple expressions from the analytical solution clearly show the functional dependence of the power supply frequency on the material properties of the load and the geometrical characteristics of the furnace installation. In conclusion, the expressions developed here provide physical insight into observations made during load signature analysis of induction heating.« less

An advanced pitch change mechanism incorporating a hybrid traction drive

NASA Technical Reports Server (NTRS)

Steinetz, B. M.; Loewenthal, S. H.; Sargisson, D. F.; White, G.

1984-01-01

A design of a propeller pitch control mechanism is described that meets the demanding requirements of a high-power, advanced turboprop. In this application, blade twisting moment torque can be comparable to that of the main reduction gearbox output: precise pitch control, reliability and compactness are all at a premium. A key element in the design is a compact, high-ratio hybrid traction drive which offers low torque ripple and high torsional stiffness. The traction drive couples a high speed electric motor/alternator unit to a ball screw that actuates the blade control links. The technical merits of this arrangement and the performance characteristics of the traction drive are discussed.

Rectus femoris muscle atrophy and recovery caused by preoperative pretibial traction in femoral shaft fractures-comparison between traction period.

PubMed

Shim, D-G; Kwon, T-Y; Lee, K-B

2017-09-01

Skeletal traction is performed to temporarily stabilize fracture sites before surgery in patients with femoral fracture. To date, however, there is no study evaluating the difference in the degree of the recovery, of the muscle strength, as well as muscle atrophy following skeletal traction. The purpose of this study was to compare the degree of recovery of rectus femoris muscle strength after surgery in association with muscle atrophy by analyzing the duration of preoperative tibial traction, age and sex in patients with femoral fracture. Rectus femoris muscle atrophy will progress depending on the duration of preoperative tibial traction, age and sex in patients with femoral fracture. Thirty-one patients who underwent preoperative pretibial skeletal traction and intramedullary nailing were divided into two groups according to the traction period: group A (n=12) with a duration of traction of <7 days (mean: 4.08±1.78 days) and group B (n=19) ≥7 days (mean: 13.63±7.17 days). The degree of muscle atrophy and recovery were compared between the two groups, according to age and gender. The degree of muscle atrophy was measured by the difference in thickness of the rectus femoris between pre- and post-traction using ultrasound. The degree of muscle recovery was evaluated by the Q-setting and heel off time. Clinical outcome was evaluated by the non-union rate and Lysholm score. The degree of muscle atrophy was 0.99±0.14mm in group A and 2.22±0.11mm in group B (P<0.001). The Q-setting time was 4.83±0.94 days in group A and 6.56±1.38 days in group B (P=0.001). Heel off time was also shorter in group A at 2.58±0.90 days, taking 3.72±1.27 days in group B (P=0.012). The recovery rate in the rectus femoris was significantly higher in group A than in group B (P<0.001). There was no significant difference in non-union rate between group A and B (P=0.672) but the mean Lysholm score at the last follow-up was significantly higher in group A than in group B (P=0.006). However, no significant differences were detected in the mean thickness of the rectus femoris, Q-setting, and heel off time between the different age and gender groups (P<0.05). The prolonged duration of preoperative skeletal traction indicates not only that the resulting disuse atrophy would progress further but also that the muscle atrophy would be accelerated more rapidly for shorter periods of time, based on a cut-off value of 7 days. In addition, the rate of rectus femoris muscle recovery and clinical outcomes were lower in patients undergoing traction for longer periods of time. This indicates that it would be effective for increasing the rate of the recovery and minimizing the occurrence of post surgical complications if surgeons could perform surgery at the earliest possible opportunity following traction, within seven days after the onset of trauma. IV, retrospective cohort study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Innovation or rebranding, acute care surgery diffusion will continue.

PubMed

Collins, Courtney E; Pringle, Patricia L; Santry, Heena P

2015-08-01

Patterns of adoption of acute care surgery (ACS) as a strategy for emergency general surgery (EGS) care are unknown. We conducted a qualitative study comprising face-to-face interviews with senior surgeons responsible for ACS at 18 teaching hospitals chosen to ensure diversity of opinions and practice environment (three practice types [community, public or charity, and university] in each of six geographic regions [Mid-Atlantic, Midwest, New England, Northeast, South, and West]). Interviews were recorded, transcribed, and analyzed using NVivo (QSR International, Melbourne, Australia). We applied the methods of investigator triangulation using an inductive approach to develop a final taxonomy of codes organized by themes related to respondents' views on the future of ACS as a strategy for EGS. We applied our findings to a conceptual model on diffusion of innovation. We found a paradox between ACS viewed as a health care delivery innovation versus a rebranding of comprehensive general surgery. Optimism for the future of ACS because of increased desirability for trauma and critical care careers as well as improved EGS outcomes was tempered by fear over lack of continuity, poor institutional resources, and uncertainty regarding financial viability. Our analysis suggests that the implementation of ACS, whether a true health care delivery innovation or an innovative rebranding, fits into the Rogers' diffusion of innovation theory. Despite concerns over resource allocation and the definition of the specialty, from the perspective of senior surgeons deeply entrenched in executing this care delivery model, ACS represents the new face of general surgery that will likely continue to diffuse from these early adopters. Published by Elsevier Inc.

Innovation or rebranding, acute care surgery diffusion will continue

PubMed Central

Collins, Courtney E.; Pringle, Patricia L.; Santry, Heena P.

2015-01-01

Background Patterns of adoption of acute care surgery (ACS) as a strategy for emergency general surgery (EGS) care are unknown. Methods We conducted a qualitative study comprising face-to-face interviews with senior surgeons responsible for ACS at 18 teaching hospitals chosen to ensure diversity of opinions and practice environment (three practice types [community, public/charity, university] in each of six geographic regions [Mid-Atlantic, Midwest, New England, Northeast, South, West]). Interviews were recorded, transcribed, and analyzed using NVivo (QSR International, Melbourne, Australia). We applied the methods of investigator triangulation using an inductive approach to develop a final taxonomy of codes organized by themes related to respondents’ views on the future of ACS as a strategy for EGS. We applied our findings to a conceptual model on diffusion of innovation. Results We found a paradox between ACS viewed as a healthcare delivery innovation versus a rebranding of comprehensive general surgery. Optimism for the future of ACS due to increased desirability for trauma/critical care careers and improved outcomes for EGS was tempered by fear over lack of continuity, poor institutional resources and uncertainty regarding financial viability. Our analysis suggests that the implementation of ACS, whether a true healthcare delivery innovation or an innovative rebranding, fits into the Rogers’ Diffusion of Innovation Theory. Conclusions Despite concerns over resource allocation and the definition of the specialty, from the perspective of senior surgeons deeply entrenched in executing this care-delivery model, ACS represents the new face of general surgery that will likely continue to diffuse from these early adopters. PMID:25891673

The Effects of Shoe Traction and Obstacle Height on Lower Extremity Coordination Dynamics during Walking

PubMed Central

Decker, Leslie; Houser, Jeremy J.; Noble, John M.; Karst, Gregory M.; Stergiou, Nicholas

2009-01-01

This study aims to investigate the effects of shoe traction and obstacle height on lower extremity relative phase dynamics (analysis of intralimb coordination) during walking to better understand the mechanisms employed to avoid slippage following obstacle clearance. Ten participants walked at a self-selected pace during eight conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two pairs of shoes (low and high traction). A coordination analysis was used and phasing relationships between lower extremity segments were examined. The results demonstrated that significant behavioral changes were elicited under varied obstacle heights and frictional conditions. Both decreasing shoe traction and increasing obstacle height resulted in a more in-phase relationship between the interacting lower limb segments. The higher the obstacle and the lower the shoe traction, the more unstable the system became. These changes in phasing relationship and variability are indicators of alterations in coordinative behavior, which if pushed further may have lead to falling. PMID:19187929

Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

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

Coffer, J.; Encalada, N.; Huang, M.

We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

Magneto acoustic emission apparatus for testing materials for embrittlement

NASA Technical Reports Server (NTRS)

Allison, Sidney G. (Inventor); Min, Namkung (Inventor); Yost, William T. (Inventor); Cantrell, John H. (Inventor)

1990-01-01

A method and apparatus for testing steel components for temper embrittlement uses magneto-acoustic emission to nondestructively evaluate the component. Acoustic emission signals occur more frequently at higher levels in embrittled components. A pair of electromagnets are used to create magnetic induction in the test component. Magneto-acoustic emission signals may be generated by applying an ac current to the electromagnets. The acoustic emission signals are analyzed to provide a comparison between a component known to be unembrittled and a test component. Magnetic remanence is determined by applying a dc current to the electromagnets, then turning the magnets off and observing the residual magnetic induction.

Synchronization algorithm for three-phase voltages of an inverter and a grid

NASA Astrophysics Data System (ADS)

Nos, O. V.

2017-07-01

This paper presents the results of designing a joint phase-locked loop for adjusting the phase shifts (speed) and Euclidean norm of three-phase voltages of an inverter to the same grid parameters. The design can be used, in particular, to match the potentials of two parallel-connected power sources for the fundamental harmonic at the moments of switching the stator windings of an induction AC motor from a converter to a centralized power-supply system and back. Technical implementation of the developed synchronization algorithm will significantly reduce the inductance of the current-balancing reactor and exclude emergency operation modes in the electric motor power circuit.

Tractional retinal detachment in Usher syndrome type II.

PubMed

Rani, Alka; Pal, Nikhil; Azad, Raj Vardhan; Sharma, Yog Raj; Chandra, Parijat; Vikram Singh, Deependra

2005-08-01

Retinal detachment is a rare complication in patients with retinitis pigmentosa. A case is reported of tractional retinal detachment in a patient with retinitis pigmentosa and sensorineural hearing loss, which was diagnosed as Usher syndrome type II. Because of the poor visual prognosis, the patient refused surgery in that eye. Tractional retinal detachment should be added to the differential diagnoses of visual loss in patients with retinitis pigmentosa.

Pins and Rubbers Traction System.

PubMed

de Soras, X; de Mourgues, P; Guinard, D; Moutet, F

1997-12-01

The Pins and Rubbers Traction System (PRTS) is a mobile frame created with wires to support elastic traction, which produces a ligamentotaxis effect in the same direction and of the same intensity whatever the position of the joint. This technique has been used in 11 cases of complex PIP joint fractures with eight excellent results. The advantages are simplicity, adaptability, the possibility of immediate mobilization, reasonable cost and relatively small bulk.

Traction reveals mechanisms of wall effects for microswimmers near boundaries

NASA Astrophysics Data System (ADS)

Shen, Xinhui; Marcos, Fu, Henry C.

2017-03-01

The influence of a plane boundary on low-Reynolds-number swimmers has frequently been studied using image systems for flow singularities. However, the boundary effect can also be expressed using a boundary integral representation over the traction on the boundary. We show that examining the traction pattern on the boundary caused by a swimmer can yield physical insights into determining when far-field multipole models are accurate. We investigate the swimming velocities and the traction of a three-sphere swimmer initially placed parallel to an infinite planar wall. In the far field, the instantaneous effect of the wall on the swimmer is well approximated by that of a multipole expansion consisting of a force dipole and a force quadrupole. On the other hand, the swimmer close to the wall must be described by a system of singularities reflecting its internal structure. We show that these limits and the transition between them can be independently identified by examining the traction pattern on the wall, either using a quantitative correlation coefficient or by visual inspection. Last, we find that for nonconstant propulsion, correlations between swimming stroke motions and internal positions are important and not captured by time-averaged traction on the wall, indicating that care must be taken when applying multipole expansions to study boundary effects in cases of nonconstant propulsion.

Traction reveals mechanisms of wall effects for microswimmers near boundaries.

PubMed

Shen, Xinhui; Marcos; Fu, Henry C

2017-03-01

The influence of a plane boundary on low-Reynolds-number swimmers has frequently been studied using image systems for flow singularities. However, the boundary effect can also be expressed using a boundary integral representation over the traction on the boundary. We show that examining the traction pattern on the boundary caused by a swimmer can yield physical insights into determining when far-field multipole models are accurate. We investigate the swimming velocities and the traction of a three-sphere swimmer initially placed parallel to an infinite planar wall. In the far field, the instantaneous effect of the wall on the swimmer is well approximated by that of a multipole expansion consisting of a force dipole and a force quadrupole. On the other hand, the swimmer close to the wall must be described by a system of singularities reflecting its internal structure. We show that these limits and the transition between them can be independently identified by examining the traction pattern on the wall, either using a quantitative correlation coefficient or by visual inspection. Last, we find that for nonconstant propulsion, correlations between swimming stroke motions and internal positions are important and not captured by time-averaged traction on the wall, indicating that care must be taken when applying multipole expansions to study boundary effects in cases of nonconstant propulsion.

The value of radiographs obtained during forced traction under general anaesthesia in predicting flexibility in idiopathic scoliosis with Cobb angles exceeding 60 degree.

PubMed

Ibrahim, T; Gabbar, O A; El-Abed, K; Hutchinson, M J; Nelson, I W

2008-11-01

Our aim in this prospective radiological study was to determine whether the flexibility rate calculated from radiographs obtained during forced traction under general anaesthesia, was better than that of fulcrum-bending radiographs before corrective surgery in predicting the extent of the available correction in patients with idiopathic scoliosis. We evaluated 33 patients with a Cobb angle > 60 degrees on a standing posteroanterior radiograph, who had been treated by posterior correction. Pre-operative standing fulcrum-bending radiographs and those with forced-traction under general anaesthesia were obtained. Post-operative standing radiographs were taken after surgical correction. The mean forced-traction flexibility rate was 55% (SD 11.3) which was significantly higher than the mean fulcrum-bending flexibility rate of 32% (SD 16.1) (p < 0.001). We found no correlation between either the forced-traction or fulcrum-bending flexibility rates and the correction rate post-operatively (p = 0.24 and p = 0.44, respectively). Radiographs obtained during forced traction under general anaesthesia were better at predicting the flexibility of the curve than fulcrum-bending radiographs in curves with a Cobb angle > 60 degrees in the standing position and may identify those patients for whom supplementary anterior surgery can be avoided.

Combined preoperative traction with instrumented posterior occipitocervical fusion for severe ventral brainstem compression secondary to displaced os odontoideum: technical report of 2 cases.

PubMed

Abd-El-Barr, Muhammad M; Snyder, Brian D; Emans, John B; Proctor, Mark R; Hedequist, Daniel

2016-12-01

Severe os odontoideum causing ventral brainstem compression is a rare and difficult entity to treat. It is generally accepted that severe os odontoideum causing ventral brainstem compression and neurological deficits warrants surgical treatment. This often requires both anterior and posterior procedures. Anterior approaches to the craniocervical junction are fraught with complications, including infection and risk of injury to neurovascular structures. External traction systems traditionally require long-term bedrest. The authors report 2 cases of severe ventral brainstem compression secondary to displaced os odontoideum and describe their use of extended preoperative halo vest traction to reduce the severe kyphosis and improve neurological function, followed by posterior occipitocervical fusion. Postoperatively both patients showed remarkable improvements in their neurological function and kyphotic deformity. Preoperative halo vest traction combined with posterior occipitocervical fusion appears to be a safe and effective method to treat brainstem compression by severe os odontoideum. It allows for adequate decompression of ventral neural structures and improvement of neurological function, but it is not hindered by the risks of anterior surgical approaches and does not restrict patients to strict bedrest as traditional traction systems. This method of halo vest traction and posterior-only approaches may be transferable to other cervical instability issues with both anterior and posterior pathologies.

Solid-state transformer-based new traction drive system and control

NASA Astrophysics Data System (ADS)

Feng, Jianghua; Shang, Jing; Zhang, Zhixue; Liu, Huadong; Huang, Zihao

2017-11-01

A new type of traction drive system consisting of solid-state traction transformer (SSTT), inverter unit, auxiliary inverter, traction motor and other key components is built in order to suit the demand of developing the next-generation electric traction system which will be efficient and lightweight, with high power density. For the purpose of reducing system volume and weight and improving efficiency and grid-side power quality, an efficient SSTT optimized topology combining high-voltage cascaded rectifiers with high-power high-frequency LLC resonant converter is proposed. On this basis, an integrated control strategy built upon synchronous rotating reference frame is presented to achieve unified control over fundamental active, reactive and harmonic components. The carrier-interleaving phase shift modulation strategy is proposed to improve the harmonic performance of cascaded rectifiers. In view of the secondary pulsating existing in a single-phase system, the mathematical model of secondary power transfer is built, and the mechanism of pulsating voltage resulting in beat frequency of LLC resonant converter is revealed, so as to design optimum matching of system parameters. Simulation and experimental results have verified that the traction system and control scheme mentioned in this paper are reasonable and superior and that they meet the future application requirements for rail transit.

A micropatterning and image processing approach to simplify measurement of cellular traction forces

PubMed Central

Polio, Samuel R.; Rothenberg, Katheryn E.; Stamenović, Dimitrije; Smith, Michael L.

2012-01-01

Quantification of the traction forces that cells apply to their surroundings has been critical to the advancement of our understanding of cancer, development and basic cell biology. This field was made possible through the development of engineered cell culture systems that permit optical measurement of cell-mediated displacements and computational algorithms that allow conversion of these displacements into stresses and forces. Here, we present a novel advancement of traction force microscopy on polyacrylamide (PAA) gels that addresses limitations of existing technologies. Through an indirect patterning technique, we generated PAA gels with fluorescent 1 μm dot markers in a regularized array. This improves existing traction measurements since (i) multiple fields of view can be measured in one experiment without the need for cell removal; (ii) traction vectors are modeled as discrete point forces, and not as a continuous field, using an extremely simple computational algorithm that we have made available online; and (iii) the pattern transfer technique is amenable to any of the published techniques for producing patterns on glass. In the future, this technique will be used for measuring traction forces on complex patterns with multiple, spatially distinct ligands in systems for applying strain to the substrate, and in sandwich cultures that generate quasi-three-dimensional environments for cells. PMID:21884832

Manual unloading of the lumbar spine: can it identify immediate responders to mechanical traction in a low back pain population? A study of reliability and criterion referenced predictive validity

PubMed Central

Swanson, Brian T.; Riley, Sean P.; Cote, Mark P.; Leger, Robin R.; Moss, Isaac L.; Carlos,, John

2016-01-01

Background To date, no research has examined the reliability or predictive validity of manual unloading tests of the lumbar spine to identify potential responders to lumbar mechanical traction. Purpose To determine: (1) the intra and inter-rater reliability of a manual unloading test of the lumbar spine and (2) the criterion referenced predictive validity for the manual unloading test. Methods Ten volunteers with low back pain (LBP) underwent a manual unloading test to establish reliability. In a separate procedure, 30 consecutive patients with LBP (age 50·86±11·51) were assessed for pain in their most provocative standing position (visual analog scale (VAS) 49·53±25·52 mm). Patients were assessed with a manual unloading test in their most provocative position followed by a single application of intermittent mechanical traction. Post traction, pain in the provocative position was reassessed and utilized as the outcome criterion. Results The test of unloading demonstrated substantial intra and inter-rater reliability K = 1·00, P = 0·002, K = 0·737, P = 0·001, respectively. There were statistically significant within group differences for pain response following traction for patients with a positive manual unloading test (P<0·001), while patients with a negative manual unloading test did not demonstrate a statistically significant change (P>0·05). There were significant between group differences for proportion of responders to traction based on manual unloading response (P = 0·031), and manual unloading response demonstrated a moderate to strong relationship with traction response Phi = 0·443, P = 0·015. Discussion and conclusion The manual unloading test appears to be a reliable test and has a moderate to strong correlation with pain relief that exceeds minimal clinically important difference (MCID) following traction supporting the validity of this test. PMID:27559274

Force Mapping during the Formation and Maturation of Cell Adhesion Sites with Multiple Optical Tweezers

PubMed Central

Schwingel, Melanie; Bastmeyer, Martin

2013-01-01

Focal contacts act as mechanosensors allowing cells to respond to their biomechanical environment. Force transmission through newly formed contact sites is a highly dynamic process requiring a stable link between the intracellular cytoskeleton and the extracellular environment. To simultaneously investigate cellular traction forces in several individual maturing adhesion sites within the same cell, we established a custom-built multiple trap optical tweezers setup. Beads functionalized with fibronectin or RGD-peptides were placed onto the apical surface of a cell and trapped with a maximum force of 160 pN. Cells form adhesion contacts around the beads as demonstrated by vinculin accumulation and start to apply traction forces after 30 seconds. Force transmission was found to strongly depend on bead size, surface density of integrin ligands and bead location on the cell surface. Highest traction forces were measured for beads positioned on the leading edge. For mouse embryonic fibroblasts, traction forces acting on single beads are in the range of 80 pN after 5 minutes. If two beads were positioned parallel to the leading edge and with a center-to-center distance less than 10 µm, traction forces acting on single beads were reduced by 40%. This indicates a spatial and temporal coordination of force development in closely related adhesion sites. We also used our setup to compare traction forces, retrograde transport velocities, and migration velocities between two cell lines (mouse melanoma and fibroblasts) and primary chick fibroblasts. We find that maximal force development differs considerably between the three cell types with the primary cells being the strongest. In addition, we observe a linear relation between force and retrograde transport velocity: a high retrograde transport velocity is associated with strong cellular traction forces. In contrast, migration velocity is inversely related to traction forces and retrograde transport velocity. PMID:23372781

Extended Constant Power Speed Range of the Brushless DC Motor Through Dual Mode Inverter Control

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

Lawler, J.S.

2000-06-23

The trapezoidal back electromotive force (emf) brushless direct current (dc) motor (BDCM) with surface-mounted magnets has high-power density and efficiency especially when rare-earth magnet materials are used. Traction applications, such as electric vehicles, could benefit significantly from the use of such motors. Unfortunately, a practical means for driving the motor over a constant power speed ratio (CPSR) of 5:1 or more has not yet been developed. A key feature of these motors is that they have low internal inductance. The phase advance method is effective in controlling the motor power over such a speed range, but the current at highmore » speed may be several times greater than that required at the base speed. The increase in current during high-speed operation is due to the low motor inductance and the action of the bypass diodes of the inverter. The use of such a control would require increased current rating of the inverter semiconductors and additional cooling for the inverter, where the conduction losses increase proportionally with current, and especially for the motor, where the losses increase with the square of the current. The high current problems of phase advance can be mitigated by adding series inductance; however, this reduces power density, requires significant increase in supply voltage, and leaves the CPSR performance of the system highly sensitive to variations in the available voltage. A new inverter topology and control scheme has been developed that can drive low-inductance BDCMs over the CPSR that would be required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC). It is shown that the BDCM has an infinite CPSR when it is driven by the DMIC.« less

Power inversion design for ocean wave energy harvesting

NASA Astrophysics Data System (ADS)

Talebani, Anwar N.

The needs for energy sources are increasing day by day because of several factors, such as oil depletion, and global climate change due to the higher level of CO2, so the exploration of various renewable energy sources is very promising area of study. The available ocean waves can be utilized as free source of energy as the water covers 70% of the earth surface. This thesis presents the ocean wave energy as a source of renewable energy. By addressing the problem of designing efficient power electronics system to deliver 5 KW from the induction generator to the grid with less possible losses and harmonics as possible and to control current fed to the grid to successfully harvest ocean wave energy. We design an AC-DC full bridge rectifier converter, and a DC-DC boost converter to harvest wave energy from AC to regulated DC. In order to increase the design efficiency, we need to increase the power factor from (0.5-0.6) to 1. This is accomplished by designing the boost converter with power factor correction in continues mode with RC circuit as an input to the boost converter power factor correction. This design results in a phase shift between the input current and voltage of the full bridge rectifier to generate a small reactive power. The reactive power is injected to the induction generator to maintain its functionality by generating a magnetic field in its stator. Next, we design a single-phase pulse width modulator full bridge voltage source DC-AC grid-tied mode inverter to harvest regulated DC wave energy to AC. The designed inverter is modulated by inner current loop, to control current injected to the grid with minimal filter component to maintain power quality at the grid. The simulation results show that our design successfully control the current level fed to the grid. It is noteworthy that the simulated efficiency is higher than the calculated one since we used an ideal switch in the simulated circuit.

Group traction drive as means to increase energy efficiency of lokomotives of open-pit transport

NASA Astrophysics Data System (ADS)

Antipin, D. Ya; Izmerov, O. V.; Bishutin, S. G.; Kobishchanov, V. V.

2017-10-01

Questions of possible use of a group drive for locomotives of an open-pit transport are considered. The possibility of a significant reduction of traction costs in the case of a combination of a group traction drive with devices for the non-inertial regulation of the coefficient of friction between the wheel and the rail has been shown, and new patentable solutions have been proposed.

An advanced pitch change mechanism incorporating a hybrid traction drive

NASA Technical Reports Server (NTRS)

Steinetz, B. M.; Sargisson, D. F.; White, G.; Loewenthal, S. H.

1984-01-01

A design of a propeller pitch control mechanism is described that meets the demanding requirements of a high-power, advanced turboprop. In this application, blade twisting moment torque can be comparable to that of the main reduction gearbox output: precise pitch control, reliability and compactness are all at a premium. A key element in the design is a compact, high-ratio hybrid traction drive which offers low torque ripple and high torsional stiffness. The traction drive couples a high speed electric motor/alternator unit to a ball screw that actuates the blade control links. The technical merits of this arrangement and the performance characteristics of the traction drive are discussed. Comparisons are made to the more conventional pitch control mechanisms.

Application of Elements of Numerical Methods in the Analysis of Journal Bearings in AC Induction Motors: An Industry Case Study

ERIC Educational Resources Information Center

Ahrens, Fred; Mistry, Rajendra

2005-01-01

In product engineering there often arise design analysis problems for which a commercial software package is either unavailable or cost prohibitive. Further, these calculations often require successive iterations that can be time intensive when performed by hand, thus development of a software application is indicated. This case relates to the…

Scalable Heuristics for Planning, Placement and Sizing of Flexible AC Transmission System Devices

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

Frolov, Vladmir; Backhaus, Scott N.; Chertkov, Michael

Aiming to relieve transmission grid congestion and improve or extend feasibility domain of the operations, we build optimization heuristics, generalizing standard AC Optimal Power Flow (OPF), for placement and sizing of Flexible Alternating Current Transmission System (FACTS) devices of the Series Compensation (SC) and Static VAR Compensation (SVC) type. One use of these devices is in resolving the case when the AC OPF solution does not exist because of congestion. Another application is developing a long-term investment strategy for placement and sizing of the SC and SVC devices to reduce operational cost and improve power system operation. SC and SVCmore » devices are represented by modification of the transmission line inductances and reactive power nodal corrections respectively. We find one placement and sizing of FACTs devices for multiple scenarios and optimal settings for each scenario simultaneously. Our solution of the nonlinear and nonconvex generalized AC-OPF consists of building a convergent sequence of convex optimizations containing only linear constraints and shows good computational scaling to larger systems. The approach is illustrated on single- and multi-scenario examples of the Matpower case-30 model.« less

Dicer interacts with SIRT7 and regulates H3K18 deacetylation in response to DNA damaging agents.

PubMed

Zhang, Pei-Ying; Li, Guiling; Deng, Zhu-Jun; Liu, Li-Yuan; Chen, Li; Tang, Jun-Zhou; Wang, Yu-Qun; Cao, Su-Ting; Fang, Yu-Xiao; Wen, Fuping; Xu, Yunsheng; Chen, Xiaoming; Shi, Ke-Qing; Li, Wen-Feng; Xie, Congying; Tang, Kai-Fu

2016-05-05

Dicer participates in heterochromatin formation in fission yeast and plants. However, whether it has a similar role in mammals remains controversial. Here we showed that the human Dicer protein interacts with SIRT7, an NAD(+)-dependent H3K18Ac (acetylated lysine 18 of histone H3) deacetylase, and holds a proportion of SIRT7 in the cytoplasm. Dicer knockdown led to an increase of chromatin-associated SIRT7 and simultaneously a decrease of cytoplasmic SIRT7, while its overexpression induced SIRT7 reduction in the chromatin-associated fraction and increment in the cytoplasm. Furthermore, DNA damaging agents promoted Dicer expression, leading to decreased level of chromatin-associated SIRT7 and increased level of H3K18Ac, which can be alleviated by Dicer knockdown. Taken together with that H3K18Ac was exclusively associated with the chromatin, our findings suggest that Dicer induction by DNA damaging treatments prevents H3K18Ac deacetylation, probably by trapping more SIRT7 in the cytoplasm. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Cadmium-induced ethylene production and responses in Arabidopsis thaliana rely on ACS2 and ACS6 gene expression

PubMed Central

2014-01-01

Background Anthropogenic activities cause metal pollution worldwide. Plants can absorb and accumulate these metals through their root system, inducing stress as a result of excess metal concentrations inside the plant. Ethylene is a regulator of multiple plant processes, and is affected by many biotic and abiotic stresses. Increased ethylene levels have been observed after exposure to excess metals but it remains unclear how the increased ethylene levels are achieved at the molecular level. In this study, the effects of cadmium (Cd) exposure on the production of ethylene and its precursor 1-aminocyclopropane-1-carboxylic acid (ACC), and on the expression of the ACC Synthase (ACS) and ACC Oxidase (ACO) multigene families were investigated in Arabidopsis thaliana. Results Increased ethylene release after Cd exposure was directly measurable in a system using rockwool-cultivated plants; enhanced levels of the ethylene precursor ACC together with higher mRNA levels of ethylene responsive genes: ACO2, ETR2 and ERF1 also indicated increased ethylene production in hydroponic culture. Regarding underlying mechanisms, it was found that the transcript levels of ACO2 and ACO4, the most abundantly expressed members of the ACO multigene family, were increased upon Cd exposure. ACC synthesis is the rate-limiting step in ethylene biosynthesis, and transcript levels of both ACS2 and ACS6 showed the highest increase and became the most abundant isoforms after Cd exposure, suggesting their importance in the Cd-induced increase of ethylene production. Conclusions Cadmium induced the biosynthesis of ACC and ethylene in Arabidopsis thaliana plants mainly via the increased expression of ACS2 and ACS6. This was confirmed in the acs2-1acs6-1 double knockout mutants, which showed a decreased ethylene production, positively affecting leaf biomass and resulting in a delayed induction of ethylene responsive gene expressions without significant differences in Cd contents between wild-type and mutant plants. PMID:25082369

Tangeretin derivative, 5-acetyloxy-6,7,8,4'-tetramethoxyflavone induces G2/M arrest, apoptosis and autophagy in human non-small cell lung cancer cells in vitro and in vivo.

PubMed

Li, Yi Rong; Li, Shiming; Ho, Chi-Tang; Chang, Ya-Han; Tan, Kok-Tong; Chung, Ting-Wen; Wang, Bing-Yen; Chen, Yu-Kuo; Lin, Chi-Chen

2016-01-01

Tangeretin, a major phytochemicals in tangerine peels--an important Chinese herb, has been found to have anti-carcinogenic properties. To improve bioavailability and increase potency of tangeretin, its derivative, 5-acetyloxy-6,7,8,4'-tetramethoxyflavone (5-AcTMF), has been synthesized and shown potent inhibition of proliferation activity against human breast and leukemia cancer cell lines. In this study, we have further investigated the anticancer effects of 5-AcTMF on CL1-5 non-small cell lung cancer cells (NSCLC) both in vitro and in vivo and demonstrated that 5-AcTMF effectively inhibited cancer cell proliferation, induced G2/M-phase arrest associated with cdc2 and CDC25c and increased in the apoptotic cells associated with caspase activation, down regulation of Bcl-2, XIAP and Survivn, inducing release of cytochrome c into the cytosol and disruption of mitochondrial membrane potential. We also found that 5-AcTMF treatment of CL1-5 activated autophagy, indicated by triggered autophagosome formation and increased LC3-II levels and formation of LC3 puncta. Moreover, we also found that 5-AcTMF lowered phophoatidylinositol 3-kinase/AKT/mTOR signaling pathway. Over-expression of AKT by AKT cDNA transfection decreased 5-AcTMF mediated apoptosis and autophagy, supporting the induction of apoptosis and autophagy by inhibition of AKT pathway. In an animal study, 5-AcTMF effectively delayed tumor growth in a nude mouse model of CL1-5 xenografts without observed adverse effect. Immunohistochemistry Analysis indicated that 5-AcTMF induced CL1-5 cell apoptosis and autophagy in vivo. Taken together, these data demonstrate that 5-AcTMF is a novel small molecule agent that can inhibit NSCLC cell proliferation, and induce G(2)/M phase arrest and via the mitochondrial apoptotic pathway and autophagy.

Development of an attention-touch control for manual cervical distraction: a pilot randomized clinical trial for patients with neck pain.

PubMed

Gudavalli, M Ram; Salsbury, Stacie A; Vining, Robert D; Long, Cynthia R; Corber, Lance; Patwardhan, Avinash G; Goertz, Christine M

2015-06-05

Manual cervical distraction (MCD) is a traction-based therapy performed with a manual contact over the cervical region producing repeating cycles while patients lie prone. This study evaluated a traction force-based minimal intervention for use as an attention-touch control in clinical trials of MCD for patients with chronic neck pain. We conducted a mixed-methods, pilot randomized clinical trial in adults with chronic neck pain. Participants were allocated to three traction force ranges of MCD: low force/minimal intervention (0-20 N), medium force (21-50 N), or high force (51-100 N). Clinicians delivered five treatments over two weeks consisting of three sets of five cycles of MCD at the C5 vertebra and occiput. Traction forces were measured at each treatment. Patient-reported outcomes included a pain visual analogue scale (VAS), Neck Disability Index (NDI), Credibility and Expectancy Questionnaire (CEQ), and adverse effects. A qualitative interview evaluated treatment group allocation perceptions. We randomized 48 participants, allocating an average of five each month. Forty-five participants completed the trial with three participants lost to follow-up. Most participants were women (65%) and white (92%) with a mean (SD) age of 46.8 (12.5) years. Mean traction force values were within the prescribed force ranges for each group at the C5 and occiput levels. Neck pain VAS demonstrated a benefit for high traction force MCD compared to the low force group [adjusted mean difference 15.6; 95% confidence interval (CI) 1.6 to 29.7]. Participants in the medium traction force group demonstrated improvements in NDI compared to the low force group (adjusted mean difference 3.0; 95% CI 0.1 to 5.9), as did participants in the high traction force group (adjusted mean difference 2.7; 95% CI -0.1 to 5.6). CEQ favored the high force group. Most low force participants correctly identified their treatment allocation in the qualitative interview. No serious adverse events were documented. This pilot study demonstrated the feasibility of a clinical trial protocol and the utility of a traction-based, minimal intervention as an attention-touch control for future efficacy trials of MCD for patients with neck pain. ClinicalTrials.gov NCT01765751 (Registration Date 30 May 2012).

The Use of Superselective Arteriography in the Evaluation of the Influence of Intracapsular Hip Joint Pressure on the Blood Flow of the Femoral Head.

PubMed

Wu, Kai; Huang, Jianhua; Wang, Qiugen

2016-01-01

We aimed to analyze the intracapsular pressure of the hip joint following femoral neck fracture and its relationship to the position of the hip or to traction and (using superselective arteriography) to evaluate the blood supply to the femoral head and the influence of traction and hip position on the blood supply. Twenty-six cases of fresh Garden type I-III femoral neck fractures were enrolled. After being placed in the neutral position, in internal rotation or with traction of 3 and 5 kg, respectively, intracapsular manometric changes were measured. Eight cases underwent superselective arteriography of the medial circumflex femoral artery and its branches under the manometric changes of the hip joint capsule. Twenty-four to 48 h after the injury, the intracapsular pressure was significantly higher on the fractured side than on the normal side. The mean pressure was 28.41 ± 9.339 mm Hg in fully extended hips in the neutral position, 79.92 ± 12.80 mm Hg in internally rotated hips, 51.39 ± 15.41 mm Hg in hips with 3 kg of traction and 64.81 ± 13.56 mm Hg in hips with 5 kg of traction. The arteriographic findings revealed that traction and internal rotation reduced the perfusion of the femoral head at the medial circumflex femoral artery and its branches, and also negatively influenced venous reflux. Traction and internal rotation both caused the intracapsular pressure of the hip joint to rise considerably, which reduced the femoral head perfusion and impeded venous reflux. This could lead to avascular necrosis of the femoral head. © 2015 S. Karger AG, Basel.

Posterior Cervical Transfacet Fusion with Facetal Spacer for the Treatment of Single-Level Cervical Radiculopathy: A Randomized, Controlled Prospective Study.

PubMed

Lenzi, Jacopo; Nardone, Antonio; Passacantilli, Emiliano; Caporlingua, Alessandro; Lapadula, Gennaro; Caporlingua, Federico

2017-04-01

Single-level cervical radiculopathy may be treated conservatively with cervical tractions. Posterior cervical transfacet fusion with a facetal spacer is a viable option. The aim of the present study is to compare posterior cervical transfacet fusion with conservative physical treatment in single-level cervical radiculopathy. A total of 80 patients were randomized in 2 groups, a surgical group in which patients were given posterior cervical transfacet fusion and a traction group in which patients were treated conservatively with mechanical cervical tractions. Visual analog scale for arm and neck, Neck Disability Index, and Short Form-36 (SF-36) questionnaires were administered preoperatively and after treatment up to 12 months. After treatment, visual analog scale arm scores were greater in traction group (4.7 vs. 1.5 the day after treatment) and at follow-up controls (traction group vs. surgical group: 5.3 vs. 0.6 at 1 month, 3.6 vs. 0.3 at 6 months, 1.8 vs. 0.2 at 12 months). Neck Disability Index scores were lower in the surgical group (surgical group vs. traction group: 4.4 vs. 20.3 at 1 month, 1.3 vs. 10.5 at 6 months). SF-36 scores were greater in the surgical group (surgical group vs. traction group: 96 vs. 70 at 1 month, 96.5 vs. 82.6 at 6 months). Neck disability index and SF-36 scores were superimposable between the groups at 12-month follow-up. No adjacent-segment arthrosis or late complications were reported at 1-year follow-up in the surgical group. posterior cervical transfacet fusion is a safe and effective procedure to treat single-level cervical radiculopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrasound Effect in the Removal of Intraradicular Posts Cemented with Different Materials.

PubMed

Berbert, Fabio Luiz Camargo Vilella; Espir, Camila Galletti; Crisci, Fernando Simões; Ferrarezz, Marcelo; de Andrade, T; Chávez-Andrade, Gisselle Moraima; Leonardo, Renato de Toledo; Saad, José Roberto Cury; Segalla, José Claudio Martins; Vaz, Luiz Geraldo; Jordão Basso, Keren Cristina Fagundes; Dantas, Andrea Abi Rached

2015-06-01

This study evaluated the effect of ultrasonic vibration on the tensile strength required to remove intraradicular post cemented with different materials. Bovine teeth were selected, and 7 mm of the cervical root canals were prepared to size 5 Largo drill, the posts were cemented with zinc phosphate, Enforce (resin) or Rely X (glass ionomer). The specimens were divided into six groups (n = 10), according to the following procedures: GI-cementation with zinc phosphate associated with traction force; GII-cementation with zinc phosphate associated with ultrasonic activation and traction force; G111-cementation with Enforce associated with traction force; GIV-cementation with Enforce associated with ultrasonic activation and traction force; GV-cementation with Rely X associated with traction force; and GVI-cementation with Rely X associated with ultrasonic activation and traction force. The tensile test was conducted using the electromechanical testing machine, the force was determined by a specialized computer program and ultrasonic activation using the Jet Sonic Four Plus (Gnatus) device in 10P. Concerning to average ranking, GI showed statistically significant difference in comparison with GII and GVI (p < 0.05); there was no statistical difference in GIII and GIV when compared to other groups (p > 0.05). The ultrasound favored the intraradicular post traction regardless of the employed cement in greater or lesser extent. The post removal is a routine practice in the dental office, therefore, new solutions and better alternatives are need to the practitioner. We did not find in the literature many articles referring to this practice. Thus, the results from this study are relevant in the case planning and to promote more treatment options.

Measurement of the traction force of biological cells by digital holography

PubMed Central

Yu, Xiao; Cross, Michael; Liu, Changgeng; Clark, David C.; Haynie, Donald T.; Kim, Myung K.

2011-01-01

The traction force produced by biological cells has been visualized as distortions in flexible substrata. We have utilized quantitative phase microscopy by digital holography (DH-QPM) to study the wrinkling of a silicone rubber film by motile fibroblasts. Surface deformation and the cellular traction force have been measured from phase profiles in a direct and straightforward manner. DH-QPM is shown to provide highly efficient and versatile means for quantitatively analyzing cellular motility. PMID:22254175

Two-staged Correction of Severe Congenital Scoliosis Associated With Intraspinal Abnormalities.

PubMed

Zhang, Zhenxing; Hui, Hua; Liu, Tuanjiang; Zhang, Zhenping; Hao, Dingjun

2016-10-01

A retrospective study. To analyze the efficacy and safety of perioperative halo-gravity traction as an adjunct to posterior vertebral column resection (PVCR) in the treatment of patients with severe congenital scoliosis and coexisting asymptomatic intraspinal pathologies (diastematomyelia and/or tethered cord). Few reports to our knowledge review the use of perioperative halo-gravity traction and PVCR in this patient population. A total of 17 patients with a minimum 2-year follow-up who underwent PVCR using perioperative halo-gravity traction were analyzed. Patients were analyzed by age at date of examination (range, 11-23 y; mean, 14.4 y), sex (7 male, 10 female), major coronal curve magnitude (range, 108-149 degrees; average, 125 degrees), major sagittal curve magnitude (range, 72-118 degrees; average, 91 degrees). Complications related to halo traction and PVCR were reviewed. Radiographic outcomes demonstrated Cobb angle of major curve had an average correction of 28% after halo traction and it measured 53 degrees (range, 42-84 degrees) at the last follow-up, for a 58% correction. Maximal kyphosis improved to 58 degrees (range, 43-76 degrees) at ultimate follow-up. There were no permanent neurological deficits in this series. The study results suggested that surgical treatment for intraspinal abnormality may be unnecessary in asymptomatic patients with severe congenital scoliosis who are undergoing scoliosis corrective surgery. PVCR combined with perioperative traction is a safe and effective alternative for such patients.

H3K9ac and HDAC2 Activity Are Involved in the Expression of Monocarboxylate Transporter 1 in Oligodendrocyte

PubMed Central

Lai, Qingwei; Du, Wantong; Wu, Jian; Wang, Xiao; Li, Xinyu; Qu, Xuebin; Wu, Xiuxiang; Dong, Fuxing; Yao, Ruiqin; Fan, Hongbin

2017-01-01

Recently, it is reported that monocarboxylate transporter 1 (MCT1) plays crucial role in oligodendrocyte differentiation and myelination. We found that MCT1 is strongly expressed in oligodendrocyte but weakly expressed in oligodendrocyte precursors (OPCs), and the underlying mechanisms remain elusive. Histone deacetylases (HDACs) activity is required for induction of oligodendrocyte differentiation and maturation. We asked whether HDACs are involved in the regulation of MCT1 expression. This work revealed that the acetylation level of histone H3K9 (H3K9ac) was much higher in mct1 gene (Slc16a1) promoter in OPCs than that in oligodendrocyte. H3K9ac regulates MCT1 expression was confirmed by HDAC acetyltransferase inhibitors trichostatin A and curcumin. Of note, there was a negative correlation between H3K9ac and MCT1 expression in oligodendrocyte. Further, we found that the levels of HDAC1, 2, and 3 protein in oligodendrocyte were obviously higher than those in OPCs. However, specific knockdown of HDAC2 but not HDAC1 and HDAC3 significantly decreased the expression of MCT1 in oligodendrocyte. Conversely, overexpression of HDAC2 remarkably enhanced the expression of MCT1. The results imply that HDAC2 is involved in H3K9ac modification which regulates the expression of MCT1 during the development of oligodendrocyte. PMID:29184483

Design of PCB search coils for AC magnetic flux density measurement

NASA Astrophysics Data System (ADS)

Ulvr, Michal

2018-04-01

This paper presents single-layer, double-layer and ten-layer planar square search coils designed for AC magnetic flux density amplitude measurement up to 1 T in the low frequency range in a 10 mm air gap. The printed-circuit-board (PCB) method was used for producing the search coils. Special attention is given to a full characterization of the PCB search coils including a comparison between the detailed analytical design method and the finite integration technique method (FIT) on the one hand, and experimental results on the other. The results show very good agreement in the resistance, inductance and search coil constant values (the area turns) and also in the frequency dependence of the search coil constant.

An induction heater device for studies of magnetic hyperthermia and specific absorption ratio measurements

NASA Astrophysics Data System (ADS)

Cano, M. E.; Barrera, A.; Estrada, J. C.; Hernandez, A.; Cordova, T.

2011-11-01

The development of a device for generating ac magnetic fields based on a resonant inverter is presented, which has been specially designed to carry out experiments of magnetic hyperthermia. By determining the electric current in the LC resonant circuit, a maximum intensity of magnetic field around of 15 mT is calculated, with a frequency around of 206 kHz. This ac magnetic field is able to heat powdered magnetic materials embedded in biological systems to be used in biomedical applications. Indeed, in order to evaluate the sensitivity of the device we also present the measurements of the specific absorption rate in phantoms performed with commercially prepared Fe3O4 and distilled water at different concentrations.

Traction sheave elevator, hoisting unit and machine space

DOEpatents

Hakala, Harri; Mustalahti, Jorma; Aulanko, Esko

2000-01-01

Traction sheave elevator consisting of an elevator car moving along elevator guide rails, a counterweight moving along counterweight guide rails, a set of hoisting ropes (3) on which the elevator car and counterweight are suspended, and a drive machine unit (6) driving a traction sheave (7) acting on the hoisting ropes (3) and placed in the elevator shaft. The drive machine unit (6) is of a flat construction. A wall of the elevator shaft is provided with a machine space with its open side facing towards the shaft, the essential parts of the drive machine unit (6) being placed in the space. The hoisting unit (9) of the traction sheave elevator consists of a substantially discoidal drive machine unit (6) and an instrument panel (8) mounted on the frame (20) of the hoisting unit.

Modulating DNA configuration by interfacial traction: an elastic rod model to characterize DNA folding and unfolding.

PubMed

Huang, Zaixing

2011-01-01

As a continuum model of DNA, a thin elastic rod subjected to interfacial interactions is used to investigate the equilibrium configuration of DNA in intracellular solution. The interfacial traction between the rod and the solution environment is derived in detail. Kirchhoff's theory of elastic rods is used to analyze the equilibrium configuration of a DNA segment under the action of the interfacial traction. The influences of the interfacial energy factor and bending stiffness on the toroidal spool formation of the DNA segment are discussed. The results show that the equilibrium configuration of DNA is mainly determined by competition between the interfacial energy and elastic strain energy of the DNA itself, and the interfacial traction is one of the forces that drives DNA folding and unfolding.

Wharton's jelly mesenchymal stromal cells have contrasting effects on proliferation and phenotype of cancer stem cells from different subtypes of lung cancer

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

Vulcano, Francesca, E-mail: francesca.vulcano@iss.it; Milazzo, Luisa, E-mail: luisa.milazzo@iss.it; Ciccarelli, Carmela, E-mail: carmela.ciccarelli@univaq.it

Studies on the role of multipotent mesenchymal stromal cells (MSC) on tumor growth have reported both a tumor promoting and a suppressive effect. The aim of the present study was to determine the effect of MSC isolated from Wharton's jelly of umbilical cord (WJMSC) on lung cancer stem cells (LCSC) derived from human lung tumors: two adenocarcinomas (AC) and two squamous cell carcinomas (SCC). LCSC derived from SCC and AC expressed, to varying extents, the more relevant stem cell markers. The effect of WJMSC on LCSC was investigated in vitro using conditioned medium (WJ-CM): a proliferation increase in AC-LCSC wasmore » observed, with an increase in the ALDH+ and in the CD133+ cell population. By contrast, WJ-CM hampered the growth of SCC-LCSC, with an increase in the pre-G1 phase indicating the induction of apoptosis. Furthermore, the ALDH+ and CD133+ population was also reduced. In vivo, subcutaneous co-transplantation of AC-LCSC/WJMSC generated larger tumors than AC-LCSC alone, characterized by an increased percentage of CD133+ and CD166+ cells. By contrast, co-transplantation of WJMSC and SCC-LCSC did not affect the tumor size. Our results strongly suggest that WJMSC exert, both in vitro and in vivo, contrasting effects on LCSC derived from different lung tumor subtypes. - Highlights: • CM from WJMSC induces apoptosis of SCC-LCSC and reduction of ALDH+ and CD133+ cells. • Specificity of SCC-LCSC inhibition by WJ-CM is proved by the use of a CM from NHDF. • WJ-CM enhance AC-LCSC proliferation and increase CD133+ and ALDH+ cell fractions. • Coinjection of WJMSC with AC-LCSC increase tumor growth with SCC-LCSC has no effect.« less

Cancer regression induced by modified CTL therapy is regulated by HLA class II and class I antigens in Japanese patients with advanced cancer.

PubMed

Araki, K; Noguchi, Y; Hirouchi, T; Yoshikawa, E; Kataoka, S; Silverni, L; Miyazawa, H; Kuzuhara, H; Suzuki, C; Shimada, Y; Hamasato, S; Maeda, N; Shimamura, Y; Ogawa, Y; Ohtsuki, Y; Fujimoto, S

2000-12-01

Autologous cancer-specific bulk CTLs are unlikely to be induced by in vitro CTL generation (ivtCTLG) using peripheral blood mononuclear cells (PBMCs) of cancer patients when autologous cancer cells are used as in vitro stimulators. However, autologous cancer-specific bulk CTLs are frequently activated when allogeneic cancer cells are used as in vitro stimulators, regardless of the type of cancer cell. We have developed a cancer-specific immunotherapy called modified CTL therapy, which involves adoptive immunotherapy of autologous cancer-specific bulk CTLs after active immunization of autologous or allogeneic cancer cells screened as in vitro stimulators according to their ability to induce autologous cancer-specific CTLs (ACS. CTLs). Cancer did not regress in patients in whom ACS.CTLs were not induced by ivtCTLG using the patients' PBMCs in therapy. Cancer regression, albeit temporary, occurred solely in patients under the immunological condition that ACS.CTLs were induced by ivtCTLG using PBMCs through the therapy. The induction of ACS.CTLs by ivtCTLG using patient PBMCs in therapy was related to patients' HLA class II antigens. HLA DR8 was seen more frequently in ACS.CTL-inducible patients than in ACS.CTL-uninducible patients (P=0.051). On the contrary, HLA DQ3 was seen more frequently in ACS.CTL-uninducible patients (P=0.055). On the other hand, the success in therapy, albeit temporary, was related mainly to patients' HLA class I antigens. HLA B61 was seen more frequently in patients whose therapy proved effective than in patients whose therapy proved ineffective (P=0.018). HLA Cw7 was seen more frequently in therapy-ineffective patients (P=0.040).

Performance testing of a high frequency link converter for Space Station power distribution system

NASA Technical Reports Server (NTRS)

Sul, S. K.; Alan, I.; Lipo, T. A.

1989-01-01

The testing of a brassboard version of a 20-kHz high-frequency ac voltage link prototype converter dynamics for Space Station application is presented. The converter is based on a three-phase six-pulse bridge concept. The testing includes details of the operation of the converter when it is driving an induction machine source/load. By adapting a field orientation controller (FOC) to the converter, four-quadrant operation of the induction machine from the converter has been achieved. Circuit modifications carried out to improve the performance of the converter are described. The performance of two 400-Hz induction machines powered by the converter with simple V/f regulation mode is reported. The testing and performance results for the converter utilizing the FOC, which provides the capability for rapid torque changes, speed reversal, and four-quadrant operation, are reported.

Electrical power generation by mechanically modulating electrical double layers.

PubMed

Moon, Jong Kyun; Jeong, Jaeki; Lee, Dongyun; Pak, Hyuk Kyu

2013-01-01

Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future.

Winter Weather Checklists

MedlinePlus

... walkways Supply of cat litter or bag of sand to add traction on walkways Flashlight and extra ... sealant for emergency tire repair Road salt and sand to help tires get traction Booster cables Emergency ...

Traction of elastohydrodynamic contacts with thermal shearing flow

NASA Technical Reports Server (NTRS)

Jakobsen, J.; Winer, W. O.

1974-01-01

The formulation and solution for the shear stress and temperature in heavily loaded sliding elastohydrodynamic contacts is presented. The solutions are presented in dimensionless design charts. Integration over the contact area will yield the traction. Accuracy is expected to be very good over the nearly flat part of the contact area where the majority of the sliding traction is generated. The procedure presented is not appropriate for thick film lubrication, for the inlet region, or for the rolling friction of elastohydrodynamic contacts.

[Clinical efficacy of alternating chemo-radiotherapy for locally advanced nasopharyngeal carcinoma].

PubMed

You, Xi; Yang, Yucheng

2014-03-01

The purpose of this study is to investigate the effective of alternating Chemo-radiotherapy for locally Advanced Nasopharyngeal Carcinoma. Retrospective analysis 106 cases of patients with locally advanced nasopharyngeal carcinoma between November 2005 and March 2007. All patients received cisplatin-based chemotherapy but 15 patients received radiotherapy(RT) alone. Inducing chemotherapy (IC) + RT + adju-vant chemotherapy (AC) regimen in 36 patients, IC+RT regimen was delivered in 25 patients and AC + RT regimen in 30 patients. 61 patients received 1 to 2 cycles of inducing chemotherapy and 66 patients received 3 to 6 cycles of adjuvant chemotherapy after radiotherapy. Chemotherapy started on the first day after the end of the induction chemotherapy, adjuvant chemotherapy begun after radiotherapy for a week. All patients were treated by radiotherapy using 60 Co r-ray, the nasophyarynx primary site was given a total does of 68 -74 Gy. The lymph nodes of the neck was given 60 to 70 Gy. The prophylactic irradiation does of the neck was 48-50 Gy. RESCULT: The median follow up time was 51 months. A total of 58 patients died, the overall survival rate was 45% in whole groups. The 5-year overall survival rates were 33%, 63%, 60% and 50% in RT, IC + RT + AC, IC + RT and RT+AC group, respectively. The 5-year disease-free survival rates were 13%, 56%, 48% and 40% in RT, IC + RT + AC, IC + RT and RT + AC group, respectively. The 5-year relapse-free survival rates were 13%, 53%, 48% and 50% in RT, IC + RT + AC, IC + RT and RT + AC group, respectively. The 5-year metastasis-free survival rates were 6%, 50%, 44% and 47% in RT, IC + RT + AC, IC+ RT and RT + AC group, respectively. There was significant difference in all groups (P < 0.05). The median time to relapses were 22 months, 29 months, 28 months and 25 months in RT, IC + RT + AC, IC + RT and RT + AC group, respectively. The median time to first distant metastasis were 10 months, 19 months, 15 months and 12 months in RT, IC + RT + AC, IC + RT and RT + AC group, respectively. There was no significant difference in all groups (P > 0.05). IC + RT + AC group had heavier acute toxicity effects than other groups, but it did not affect the treatment process, all patients could be tolerated. This retrospective study has demonstrated that alternating Chemo-radiotherapy and early radiotherapy not only can improve the survival rate for locally Advanced Nasopharyngeal Carcinoma, but also have slight toxicities and side reaction, all patients may tolerated.

Method and apparatus for using magneto-acoustic remanence to determine embrittlement

NASA Technical Reports Server (NTRS)

Allison, Sidney G. (Inventor); Namkung, Min (Inventor); Yost, William T. (Inventor); Cantrell, John H. (Inventor)

1992-01-01

A method and apparatus for testing steel components for temperature embrittlement uses magneto-acoustic emission to nondestructively evaluate the component are presented. Acoustic emission signals occur more frequently at higher levels in embrittled components. A pair of electromagnets are used to create magnetic induction in the test component. Magneto-acoustic emission signals may be generated by applying an AC current to the electromagnets. The acoustic emission signals are analyzed to provide a comparison between a component known to be unembrittled and a test component. Magnetic remanence is determined by applying a DC current to the electromagnets and then by turning the magnets off and observing the residual magnetic induction.

High-Force Versus Low-Force Lumbar Traction in Acute Lumbar Sciatica Due to Disc Herniation: A Preliminary Randomized Trial.

PubMed

Isner-Horobeti, Marie-Eve; Dufour, Stéphane Pascal; Schaeffer, Michael; Sauleau, Erik; Vautravers, Philippe; Lecocq, Jehan; Dupeyron, Arnaud

This study compared the effects of high-force versus low-force lumbar traction in the treatment of acute lumbar sciatica secondary to disc herniation. A randomized double blind trial was performed, and 17 subjects with acute lumbar sciatica secondary to disc herniation were assigned to high-force traction at 50% body weight (BW; LT50, n = 8) or low force traction at 10% BW (LT10, n = 9) for 10 sessions in 2 weeks. Radicular pain (visual analogue scale [VAS]), lumbo-pelvic-hip complex motion (finger-to-toe test), lumbar-spine mobility (Schöber-Macrae test), nerve root compression (straight-leg-raising test), disability (EIFEL score), drug consumption, and overall evaluation of each patient were measured at days 0, 7, 1, 4, and 28. Significant (P < .05) improvements were observed in the LT50 and LT10 groups, respectively, between day 0 and day 14 (end of treatment) for VAS (-44% and -36%), EIFEL score (-43% and -28%) and overall patient evaluation (+3.1 and +2.0 points). At that time, LT50 specifically improved in the finger-to-toe test (-42%), the straight-leg-raising test (+58), and drug consumption (-50%). No significant interaction effect (group-by-time) was revealed, and the effect of traction treatment was independent of the level of medication. During the 2-week follow-up at day 28, only the LT10 group improved (P < .05) in VAS (-52%) and EIFEL scores (-46%). During this period, no interaction effect (group-by-time) was identified, and the observed responses were independent of the level of medication. For this preliminary study, patients with acute lumbar sciatica secondary to disc herniation who received 2 weeks of lumbar traction reported reduced radicular pain and functional impairment and improved well-being regardless of the traction force group to which they were assigned. The effects of the traction treatment were independent of the initial level of medication and appeared to be maintained at the 2-week follow-up. Copyright © 2016. Published by Elsevier Inc.

Acute quadriplegia following closed traction reduction of a cervical facet dislocation in the setting of ossification of the posterior longitudinal ligament: case report.

PubMed

Wimberley, David W; Vaccaro, Alexander R; Goyal, Nitin; Harrop, James S; Anderson, D Greg; Albert, Todd J; Hilibrand, Alan S

2005-08-01

A case report of acute quadriplegia resulting from closed traction reduction of traumatic bilateral cervical facet dislocation in a 54-year-old male with concomitant ossification of the posterior longitudinal ligament (OPLL). To report an unusual presentation of a spinal cord injury, examine the approach to reversal of the injury, and review the treatment and management controversies of acute cervical facet dislocations in specific patient subgroups. The treatment of acute cervical facet dislocations is an area of ongoing controversy, especially regarding the question of the necessity of advanced imaging studies before closed traction reduction of the dislocated cervical spine. The safety of an immediate closed, traction reduction of the cervical spine in awake, alert, cooperative, and appropriately select patients has been reported in several studies. To date, there have been no permanent neurologic deficits resulting from awake, closed reduction reported in the literature. A case of temporary, acute quadriplegia with complete neurologic recovery following successful closed traction reduction of a bilateral cervical facet dislocation in the setting of OPLL is presented. The clinical neurologic examination, radiographic, and advanced imaging studies before and after closed, traction reduction of a cervical facet dislocation are evaluated and discussed. A review of the literature regarding the treatment of acute cervical facet dislocations is presented. Radiographs showed approximately 50% subluxation of the fifth on the sixth cervical vertebrae, along with computerized tomography revealing extensive discontinuous OPLL. The cervical facet dislocation was successfully reduced with an awake, closed traction reduction, before magnetic resonance imaging (MRI) evaluation. The patient subsequently had acute quadriplegia develop, with the ensuing MRI study illustrating severe spinal stenosis at the C5, C6 level as a result of OPLL or a large extruded disc herniation. Following an immediate anterior decompression and a posterior stabilization procedure, the patient regained full motor and sensory function. This case report highlights the advantages and shows some safety concerns regarding immediate, closed traction reduction of cervical facet dislocation with real-time neural monitoring in an awake, alert, oriented, and appropriately select patient before MRI studies in the setting of preexisting central stenosis from OPLL.

Power Factor Controller

NASA Technical Reports Server (NTRS)

1997-01-01

Frank Nola invented the Power Factor Controller (PFC) at Marshall Space Flight Center more than a decade ago. Nola came up with a way to curb power wastage in AC induction motors. The PFC matches voltage with the motor's actual need by continuously sensing shifts between voltage and current. When it senses a light load it cuts the voltage to the minimum needed. Potential energy savings range from 8 to 65 percent.

Benefit from NASA

NASA Image and Video Library

1997-01-01

Frank Nola invented the Power Factor Controller (PFC) at Marshall Space Flight Center more than a decade ago. Nola came up with a way to curb power wastage in AC induction motors. The PFC matches voltage with the motor's actual need by continuously sensing shifts between voltage and current. When it senses a light load it cuts the voltage to the minimum needed. Potential energy savings range from 8 to 65 percent.

Effective switching frequency multiplier inverter

DOEpatents

Su, Gui-Jia [Oak Ridge, TN; Peng, Fang Z [Okemos, MI

2007-08-07

A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian, Dugesia tigrina

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

Jenrow, K.A.; Smith, C.H.; Liboff, A.R.

1996-12-31

The authors recently reported that cephalic regeneration in the planarian Dugesia tigrina was significantly delayed in populations exposed continuously to combined parallel DC and AC magnetic fields. This effect was consistent with hypotheses suggesting an underlying resonance phenomenon. The authors report here, in a parallel series of investigations on the same model system, that the incidence of regeneration anomalies presenting as tumor-like protuberances also increases significantly (P < .001) in association with exposure to weak 60 Hz magnetic fields, with peak intensities ranging between 1.0 and 80.0 {micro}T. These anomalies often culminate in the complete disaggregation of the organism. Similarmore » to regeneration rate effects, the incidence of regeneration anomalies is specifically dependent upon the planaria possessing a fixed orientation with respect to the applied magnetic field vectors. However, unlike the regeneration rate effects, the AC magnetic field alone, in the absence of any measurable DC field, is capable of producing these anomalies. Moreover, the incidence of regeneration anomalies follows a clear dose-response relationship as a function of AC magnetic field intensity, with the threshold for induced electric field intensity estimated at 5 {micro} V/m. The addition of either 51.1 or 78.4 {micro}T DC magnetic fields, applied in parallel combination with the AC field, enhances the appearance of anomalies relative to the 60 Hz AC field alone, but only at certain AC field intensities. Thus, whereas the previous study of regeneration rate effects appeared to involve exclusively resonance interactions, the regeneration anomalies reported here appear to result primarily from Faraday induction coupling.« less

What Is the Best Treatment of Locally Advanced Nasopharyngeal Carcinoma? An Individual Patient Data Network Meta-Analysis

PubMed Central

Ribassin-Majed, Laureen; Marguet, Sophie; Lee, Anne W.M.; Ng, Wai Tong; Ma, Jun; Chan, Anthony T.C.; Huang, Pei-Yu; Zhu, Guopei; Chua, Daniel T.T.; Chen, Yong; Mai, Hai-Qiang; Kwong, Dora L.W.; Cheah, Shie-Lee; Moon, James; Tung, Yuk; Chi, Kwan-Hwa; Fountzilas, George; Bourhis, Jean; Pignon, Jean Pierre

2017-01-01

Purpose The role of adjuvant chemotherapy (AC) or induction chemotherapy (IC) in the treatment of locally advanced nasopharyngeal carcinoma is controversial. The individual patient data from the Meta-Analysis of Chemotherapy in Nasopharynx Carcinoma database were used to compare all available treatments. Methods All randomized trials of radiotherapy (RT) with or without chemotherapy in nonmetastatic nasopharyngeal carcinoma were considered. Overall, 20 trials and 5,144 patients were included. Treatments were grouped into seven categories: RT alone (RT), IC followed by RT (IC-RT), RT followed by AC (RT-AC), IC followed by RT followed by AC (IC-RT-AC), concomitant chemoradiotherapy (CRT), IC followed by CRT (IC-CRT), and CRT followed by AC (CRT-AC). P-score was used to rank the treatments. Fixed- and random-effects frequentist network meta-analysis models were applied. Results The three treatments with the highest probability of benefit on overall survival (OS) were CRT-AC, followed by CRT and IC-CRT, with respective hazard ratios (HRs [95% CIs]) compared with RT alone of 0.65 (0.56 to 0.75), 0.77 (0.64 to 0.92), and 0.81 (0.63 to 1.04). HRs (95% CIs) of CRT-AC compared with CRT for OS, progression-free survival (PFS), locoregional control, and distant control (DC) were, respectively, 0.85 (0.68 to 1.05), 0.81 (0.66 to 0.98), 0.70 (0.48 to 1.02), and 0.87 (0.61 to 1.25). IC-CRT ranked second for PFS and the best for DC. CRT never ranked first. HRs of CRT compared with IC-CRT for OS, PFS, locoregional control, and DC were, respectively, 0.95 (0.72 to 1.25), 1.13 (0.88 to 1.46), 1.05 (0.70 to 1.59), and 1.55 (0.94 to 2.56). Regimens with more chemotherapy were associated with increased risk of acute toxicity. Conclusion The addition of AC to CRT achieved the highest survival benefit and consistent improvement for all end points. The addition of IC to CRT achieved the highest effect on DC. PMID:27918720

AC electrokinetic drug delivery in dentistry using an interdigitated electrode assembly powered by inductive coupling.

PubMed

Ivanoff, Chris S; Wu, Jie Jayne; Mirzajani, Hadi; Cheng, Cheng; Yuan, Quan; Kevorkyan, Stepan; Gaydarova, Radostina; Tomlekova, Desislava

2016-10-01

AC electrokinetics (ACEK) has been shown to deliver certain drugs into human teeth more effectively than diffusion. However, using electrical wires to power intraoral ACEK devices poses risks to patients. The study demonstrates a novel interdigitated electrode arrays (IDE) assembly powered by inductive coupling to induce ACEK effects at appropriate frequencies to motivate drugs wirelessly. A signal generator produces the modulating signal, which multiplies with the carrier signal to produce the amplitude modulated (AM) signal. The AM signal goes through the inductive link to appear on the secondary coil, then rectified and filtered to dispose of its carrier signal, and the positive half of the modulating signal appears on the load. After characterizing the device, the device is validated under light microscopy by motivating carboxylate-modified microspheres, tetracycline, acetaminophen, benzocaine, lidocaine and carbamide peroxide particles with induced ACEK effects. The assembly is finally tested in a common dental bleaching application. After applying 35 % carbamide peroxide to human teeth topically or with the IDE at 1200 Hz, 5 Vpp for 20 min, spectrophotometric analysis showed that compared to diffusion, the IDE enhanced whitening in specular optic and specular optic excluded modes by 215 % and 194 % respectively. Carbamide peroxide absorbance by the ACEK group was two times greater than diffusion as measured by colorimetric oxidation-reduction and UV-Vis spectroscopy at 550 nm. The device motivates drugs of variable molecular weight and structure wirelessly. Wireless transport of drugs to intraoral targets under ACEK effects may potentially improve the efficacy and safety of drug delivery in dentistry.

E-Cadherin-Dependent Stimulation of Traction Force at Focal Adhesions via the Src and PI3K Signaling Pathways

PubMed Central

Jasaitis, Audrius; Estevez, Maruxa; Heysch, Julie; Ladoux, Benoit; Dufour, Sylvie

2012-01-01

The interplay between cadherin- and integrin-dependent signals controls cell behavior, but the precise mechanisms that regulate the strength of adhesion to the extracellular matrix remains poorly understood. We deposited cells expressing a defined repertoire of cadherins and integrins on fibronectin (FN)-coated polyacrylamide gels (FN-PAG) and on FN-coated pillars used as a micro-force sensor array (μFSA), and analyzed the functional relationship between these adhesion receptors to determine how it regulates cell traction force. We found that cadherin-mediated adhesion stimulated cell spreading on FN-PAG, and this was modulated by the substrate stiffness. We compared S180 cells with cells stably expressing different cadherins on μFSA and found that traction forces were stronger in cells expressing cadherins than in parental cells. E-cadherin-mediated contact and mechanical coupling between cells are required for this increase in cell-FN traction force, which was not observed in isolated cells, and required Src and PI3K activities. Traction forces were stronger in cells expressing type I cadherins than in cells expressing type II cadherins, which correlates with our previous observation of a higher intercellular adhesion strength developed by type I compared with type II cadherins. Our results reveal one of the mechanisms whereby molecular cross talk between cadherins and integrins upregulates traction forces at cell-FN adhesion sites, and thus provide additional insight into the molecular control of cell behavior. PMID:22853894

Micropatterning tractional forces in living cells

NASA Technical Reports Server (NTRS)

Wang, Ning; Ostuni, Emanuele; Whitesides, George M.; Ingber, Donald E.

2002-01-01

Here we describe a method for quantifying traction in cells that are physically constrained within micron-sized adhesive islands of defined shape and size on the surface of flexible polyacrylamide gels that contain fluorescent microbeads (0.2-microm diameter). Smooth muscle cells were plated onto square (50 x 50 microm) or circular (25- or 50-microm diameter) adhesive islands that were created on the surface of the gels by applying a collagen coating through microengineered holes in an elastomeric membrane that was later removed. Adherent cells spread to take on the size and shape of the islands and cell tractions were quantitated by mapping displacement fields of the fluorescent microbeads within the gel. Cells on round islands did not exhibit any preferential direction of force application, but they exerted their strongest traction at sites where they formed protrusions. When cells were confined to squares, traction was highest in the corners both in the absence and presence of the contractile agonist, histamine, and cell protrusions were also observed in these regions. Quantitation of the mean traction exerted by cells cultured on the different islands revealed that cell tension increased as cell spreading was promoted. These results provide a mechanical basis for past studies that demonstrated a similar correlation between spreading and growth within various anchorage-dependent cells. This new approach for analyzing the spatial distribution of mechanical forces beneath individual cells that are experimentally constrained to defined sizes and shapes may provide additional insight into the biophysical basis of cell regulation. Copyright 2002 Wiley-Liss, Inc.

An Efficient Implementation of the GMC Micromechanics Model for Multi-Phased Materials with Complex Microstructures

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Bednarcyk, Brett A.

1997-01-01

An efficient implementation of the generalized method of cells micromechanics model is presented that allows analysis of periodic unidirectional composites characterized by repeating unit cells containing thousands of subcells. The original formulation, given in terms of Hill's strain concentration matrices that relate average subcell strains to the macroscopic strains, is reformulated in terms of the interfacial subcell tractions as the basic unknowns. This is accomplished by expressing the displacement continuity equations in terms of the stresses and then imposing the traction continuity conditions directly. The result is a mixed formulation wherein the unknown interfacial subcell traction components are related to the macroscopic strain components. Because the stress field throughout the repeating unit cell is piece-wise uniform, the imposition of traction continuity conditions directly in the displacement continuity equations, expressed in terms of stresses, substantially reduces the number of unknown subcell traction (and stress) components, and thus the size of the system of equations that must be solved. Further reduction in the size of the system of continuity equations is obtained by separating the normal and shear traction equations in those instances where the individual subcells are, at most, orthotropic. The reformulated version facilitates detailed analysis of the impact of the fiber cross-section geometry and arrangement on the response of multi-phased unidirectional composites with and without evolving damage. Comparison of execution times obtained with the original and reformulated versions of the generalized method of cells demonstrates the new version's efficiency.

Efficacy of a single oral dose of a live bivalent E. coli vaccine against post-weaning diarrhea due to F4 and F18-positive enterotoxigenic E. coli.

PubMed

Nadeau, É; Fairbrother, J M; Zentek, J; Bélanger, L; Tremblay, D; Tremblay, C-L; Röhe, I; Vahjen, W; Brunelle, M; Hellmann, K; Cvejić, D; Brunner, B; Schneider, C; Bauer, K; Wolf, R; Hidalgo, Á

2017-08-01

F4- and F18-positive enterotoxigenic E. coli strains (F4-ETEC and F18-ETEC) are important causes of post-weaning diarrhea (PWD) in pigs. F4 (antigenic variant ac) and F18 (ab and ac) fimbriae are major antigens that play an important role in the early stages of infection. Herein, the efficacy of a live oral vaccine consisting of two non-pathogenic E. coli strains, one F4ac- and one F18ac-positive, was evaluated using F4ac-ETEC and F18ab-ETEC challenge models. A randomized, masked, placebo-controlled, block design, parallel-group confirmatory study with two different vaccination-challenge intervals (7 and 21 days) was conducted for each challenge model. The vaccine was administered in one dose, to ≥18-day-old piglets via drinking water. Efficacy was assessed by evaluating diarrhea, clinical observations, weight gain and fecal shedding of F4-ETEC or F18-ETEC. Anti-F4 and anti-F18 immunoglobulins in blood were measured. The vaccination resulted in significant reductions in clinical PWD and fecal shedding of F4-ETEC and F18-ETEC after the 7- and 21-day-post-vaccination heterologous challenges, except for after the 21-day-post-vaccination F4-ETEC challenge, when the clinical PWD was too mild to demonstrate efficacy. A significant reduction of mortality and weight loss by vaccination were observed following the F18-ETEC challenge. The 7-day protection was associated with induction of anti-F4 and anti-F18 IgM, whereas the 21-day protection was mainly associated with anti-F4 and anti-F18 IgA. The 7-day onset and 21-day duration of protection induced by this vaccine administered once in drinking water to pigs of at least 18days of age were confirmed by protection against F4-ETEC and F18-ETEC, and induction of F4 and F18-specific immunity. Cross protection of the vaccine against F18ab-E. coli was demonstrated for both the 7- and 21-day F18-ETEC challenges. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Construction of conditional acid ceramidase knockout mice and in vivo effects on oocyte development and fertility.

PubMed

Eliyahu, Efrat; Shtraizent, Nataly; Shalgi, Ruth; Schuchman, Edward H

2012-01-01

The number of resting follicles in the ovary and their successful maturation during development define the fertile female lifespan. Oocytes, enclosed within follicles, are subject to natural selection, and the majority will undergo apoptosis during prenatal life through adulthood. Our previous studies revealed high levels of the lipid hydrolase, acid ceramidase (AC), in human and mouse oocytes, follicular fluid and cumulus cells. In addition, supplementation of in vitro fertilization media with recombinant AC enhanced the survival of oocytes and preimplantation embryos. Herein we constructed and used a conditional knockout mouse model of AC deficiency (cACKO) to further investigate the role of this enzyme in oocyte survival in vivo. Immunohistochemical staining, activity assays, and western blot analysis revealed that AC expression was high in the ovaries of normal mice, particularly in the theca cells. After induction of the AC gene knockout with tamoxifen (TM), AC levels decreased in ovaries, and ceramide was correspondingly elevated. A novel immunostaining method was developed to visualize follicles at various stages, and together with light microscopic examination, the transition of the follicle from the secondary to antral stage was found to be defective in the absence of AC. Western blot analysis showed elevated BAX and PARP expression in TM-treated cACKO mouse ovaries compared to control animals. In parallel, the levels of BCL-2 and anti-Mullerian hormone, a marker of ovarian reserve, were decreased. In addition to the above, there was a significant decrease in fertility observed in the TM-treated cACKO mice. Together, these data suggest that AC plays an important role in the preservation of fertility by maintaining low ceramide levels and preventing apoptosis of theca cells, thereby promoting survival of the follicle during the transition from the secondary to antral stage. Copyright © 2012 S. Karger AG, Basel.

Intravenous nitroglycerin for controlled cord traction in the management of retained placenta.

PubMed

Visalyaputra, Shusee; Prechapanich, Japarath; Suwanvichai, Sukanya; Yimyam, Suwimol; Permpolprasert, Ladda; Suksopee, Pattipa

2011-02-01

To determine the effect of 200 μg of intravenous nitroglycerin in the release of retained placenta by controlled cord traction. In this randomized controlled study, 40 women with a placenta retained for 30 minutes received intravenously 200 μg of nitroglycerin or a normal saline solution before umbilical cord traction was initiated. The rates of successful removal of the retained placenta in the study (n=20) and control (n=20) groups were compared, as were blood pressure, pulse rate, blood loss, and adverse effects. The placenta was released in only 15% and 20% of the participants in the study and control group, respectively. The remainder of the participants required general anesthesia and manual removal of the retained placenta regardless of group assignation. Blood pressure fell in significantly more women in the study group, but there were no differences in estimated blood loss or minor adverse effects. Intravenously administered nitroglycerin did not facilitate the release of retained placenta by umbilical cord traction. However, cord traction may be performed longer than 30 minutes to attempt releasing the placenta before operative manual removal is initiated. Copyright © 2010 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Determination of the thermal stress wave propagation in orthotropic hollow cylinder based on classical theory of thermoelasticity

NASA Astrophysics Data System (ADS)

Shahani, Amir Reza; Sharifi Torki, Hamid

2018-01-01

The thermoelasticity problem in a thick-walled orthotropic hollow cylinder is solved analytically using finite Hankel transform and Laplace transform. Time-dependent thermal and mechanical boundary conditions are applied on the inner and the outer surfaces of the cylinder. For solving the energy equation, the temperature itself is considered as boundary condition to be applied on both the inner and the outer surfaces of the orthotropic cylinder. Two different cases are assumed for solving the equation of motion: traction-traction problem (tractions are prescribed on both the inner and the outer surfaces) and traction-displacement (traction is prescribed on the inner surface and displacement is prescribed on the outer surface of the hollow orthotropic cylinder). Due to considering uncoupled theory, after obtaining temperature distribution, the dynamical structural problem is solved and closed-form relations are derived for radial displacement, radial and hoop stress. As a case study, exponentially decaying temperature with respect to time is prescribed on the inner surface of the cylinder and the temperature of the outer surface is considered to be zero. Owing to solving dynamical problem, the stress wave propagation and its reflections were observed after plotting the results in both cases.

Identifying traction-separation behavior of self-adhesive polymeric films from in situ digital images under T-peeling

NASA Astrophysics Data System (ADS)

Nase, Michael; Rennert, Mirko; Naumenko, Konstantin; Eremeyev, Victor A.

2016-06-01

In this paper procedures are developed to identify traction-separation curves from digital images of the deformed flexible films during peeling. T-peel tests were performed for self-adhesive polymeric films. High quality photographs of the deformed shape within and outside the zone of adhesive interaction were made in situ by the digital light microscope. The deformed line is approximated by a power series with coefficients computed by minimizing a least squares functional. Two approaches to identify the traction-separation curve for the given deformation line are proposed. The first one is based on the energy integral of the non-linear theory of rods and allows the direct evaluation of the adhesion force potential. The second one utilizes the complementary energy type variational equation and the Ritz method to compute the adhesion force. The accuracy of both approaches is analyzed with respect to different approximations for the deformed line and the force of interaction. The obtained traction vs. axial coordinate and the traction-separation curves provide several properties of the adhesive system including the maximum adhesion force, the length of the adhesive zone and the equilibrium position, where the adhesive force is zero while the separation is positive.

EFFECTS OF A MODIFIED VITRECTOMY PROBE IN SMALL-GAUGE VITRECTOMY: An Experimental Study on the Flow and on the Traction Exerted on the Retina.

PubMed

Rizzo, Stanislao; Fantoni, Gualtiero; de Santis, Giovanni; Lue, Jaw-Chyng Lormen; Ciampi, Jonathan; Palla, Michele; Genovesi Ebert, Federica; Savastano, Alfonso; De Maria, Carmelo; Vozzi, Giovanni; Brant Fernandes, Rodrigo A; Faraldi, Francesco; Criscenti, Giuseppe

2017-09-01

Thorough this experimental study, the physic features of a modified 23-gauge vitrectomy probe were evaluated in vitro. A modified vitrectomy probe to increase vitreous outflow rate with a small-diameter probe, that also minimized tractional forces on the retina, was created and tested. The "new" probe was created by drilling an opening into the inner duct of a traditional 23-gauge probe with electrochemical or electrodischarge micromachining. Both vitreous outflow and tractional forces on the retina were examined using experimental models of vitreous surgery. The additional opening allowed the modified probe to have a cutting rate of 5,000 cuts per minute, while sustaining an outflow approximately 45% higher than in conventional 23-gauge probes. The modified probe performed two cutting actions per cycle, not one, as in standard probes. Because tractional force is influenced by cutting rate, retinal forces were 2.2 times lower than those observed with traditional cutters. The modified probe could be useful in vitreoretinal surgery. It allows for faster vitreous removal while minimizing tractional forces on the retina. Moreover, any available probe can be modified by creating a hole in the inner duct.

High Resolution, Large Deformation 3D Traction Force Microscopy

PubMed Central

López-Fagundo, Cristina; Reichner, Jonathan; Hoffman-Kim, Diane; Franck, Christian

2014-01-01

Traction Force Microscopy (TFM) is a powerful approach for quantifying cell-material interactions that over the last two decades has contributed significantly to our understanding of cellular mechanosensing and mechanotransduction. In addition, recent advances in three-dimensional (3D) imaging and traction force analysis (3D TFM) have highlighted the significance of the third dimension in influencing various cellular processes. Yet irrespective of dimensionality, almost all TFM approaches have relied on a linear elastic theory framework to calculate cell surface tractions. Here we present a new high resolution 3D TFM algorithm which utilizes a large deformation formulation to quantify cellular displacement fields with unprecedented resolution. The results feature some of the first experimental evidence that cells are indeed capable of exerting large material deformations, which require the formulation of a new theoretical TFM framework to accurately calculate the traction forces. Based on our previous 3D TFM technique, we reformulate our approach to accurately account for large material deformation and quantitatively contrast and compare both linear and large deformation frameworks as a function of the applied cell deformation. Particular attention is paid in estimating the accuracy penalty associated with utilizing a traditional linear elastic approach in the presence of large deformation gradients. PMID:24740435

Model for adhesion clutch explains biphasic relationship between actin flow and traction at the cell leading edge

PubMed Central

Craig, Erin M.; Stricker, Jonathan; Gardel, Margaret L.; Mogilner, Alex

2015-01-01

Cell motility relies on the continuous reorganization of a dynamic actin-myosin-adhesion network at the leading edge of the cell, in order to generate protrusion at the leading edge and traction between the cell and its external environment. We analyze experimentally measured spatial distributions of actin flow, traction force, myosin density, and adhesion density in control and pharmacologically perturbed epithelial cells in order to develop a mechanical model of the actin-adhesion-myosin self-organization at the leading edge. A model in which the F-actin network is treated as a viscous gel, and adhesion clutch engagement is strengthened by myosin but weakened by actin flow, can explain the measured molecular distributions and correctly predict the spatial distributions of the actin flow and traction stress. We test the model by comparing its predictions with measurements of the actin flow and traction stress in cells with fast and slow actin polymerization rates. The model predicts how the location of the lamellipodium-lamellum boundary depends on the actin viscosity and adhesion strength. The model further predicts that the location of the lamellipodium-lamellum boundary is not very sensitive to the level of myosin contraction. PMID:25969948

Enhanced inductance in laminated multilayer magnetic planar inductor for sensitive magnetic field detection

NASA Astrophysics Data System (ADS)

Wang, Yao; Wen, Yumei; Song, Fapeng; Li, Ping; Yu, Shumin

2018-04-01

The authors reported laminated multilayer magnetic planar inductors for sensitive magnetic field detection, which consist of two serially connected sandwich planar inductors (i.e., FeCuNbSiB/micro planar coil/FeCuNbSiB/micro planar coil/FeCuNbSiB). When ac current is applied to coils, the greatly increased inductance by the incorporated high permeability magnetic material and enlarged mutual-inductance among coils significantly improve the sensor sensitivity to the dc magnetic field. The demagnetizing field is also found to affect the performance severely when the shape and the number of magnetic layers vary. The investigation indicates that the proposed laminate can provide an inductance ratio of 665% at the frequency of 1 kHz. By connecting the sensor with a capacitor, the sensor output with varying dc magnetic fields is obtained by tuning the resonant frequency shift. The study indicates that the proposed sensor can provide a sensitivity of about 3.57 kHz/Oe with a resolution of 28 nT between 2 Oe and 60 Oe, which outperforms most of the magnetic sensors with frequency shifting output.

A Soft-Switching Inverter for High-Temperature Advanced Hybrid Electric Vehicle Traction Motor Drives

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

Lai, Jason; Yu, Wensong; Sun, Pengwei

2012-03-31

The state-of-the-art hybrid electric vehicles (HEVs) require the inverter cooling system to have a separate loop to avoid power semiconductor junction over temperatures because the engine coolant temperature of 105°C does not allow for much temperature rise in silicon devices. The proposed work is to develop an advanced soft-switching inverter that will eliminate the device switching loss and cut down the power loss so that the inverter can operate at high-temperature conditions while operating at high switching frequencies with small current ripple in low inductance based permanent magnet motors. The proposed tasks also include high-temperature packaging and thermal modeling andmore » simulation to ensure the packaged module can operate at the desired temperature. The developed module will be integrated with the motor and vehicle controller for dynamometer and in-vehicle testing to prove its superiority. This report will describe the detailed technical design of the soft-switching inverters and their test results. The experiments were conducted both in module level for the module conduction and switching characteristics and in inverter level for its efficiency under inductive and dynamometer load conditions. The performance will be compared with the DOE original specification.« less

Demonstrating Cell Traction--Using Hens' Egg Vitelline Membrane as Substratum.

ERIC Educational Resources Information Center

Downie, Roger

1987-01-01

Suggests ways in which hens' egg vitelline membranes can be used to demonstrate cell traction effects. Reviews procedures for using and culturing the membranes and identifies topic areas for student projects. (ML)

Adaptive control system of dump truck traction electric drive

NASA Astrophysics Data System (ADS)

Bolshunova, O. M.; Korzhev, A. A.; Kamyshyan, A. M.

2018-03-01

The paper describes the operational factors that determine the accident rate of a quarry motor vehicle and assessment of their impact on the choice of the operation mode of the traction drive control system.

The forced swimming-induced behavioural immobility response involves histone H3 phospho-acetylation and c-Fos induction in dentate gyrus granule neurons via activation of the N-methyl-D-aspartate/extracellular signal-regulated kinase/mitogen- and stress-activated kinase signalling pathway.

PubMed

Chandramohan, Yalini; Droste, Susanne K; Arthur, J Simon C; Reul, Johannes M H M

2008-05-01

The hippocampus is involved in learning and memory. Previously, we have shown that the acquisition of the behavioural immobility response after a forced swim experience is associated with chromatin modifications and transcriptional induction in dentate gyrus granule neurons. Given that both N-methyl-D-aspartate (NMDA) receptors and the extracellular signal-regulated kinases (ERK) 1/2 signalling pathway are involved in neuroplasticity processes underlying learning and memory, we investigated in rats and mice whether these signalling pathways regulate chromatin modifications and transcriptional events participating in the acquisition of the immobility response. We found that: (i) forced swimming evoked a transient increase in the number of phospho-acetylated histone H3-positive [P(Ser10)-Ac(Lys14)-H3(+)] neurons specifically in the middle and superficial aspects of the dentate gyrus granule cell layer; (ii) antagonism of NMDA receptors and inhibition of ERK1/2 signalling blocked forced swimming-induced histone H3 phospho-acetylation and the acquisition of the behavioural immobility response; (iii) double knockout (DKO) of the histone H3 kinase mitogen- and stress-activated kinases (MSK) 1/2 in mice completely abolished the forced swimming-induced increases in histone H3 phospho-acetylation and c-Fos induction in dentate granule neurons and the behavioural immobility response; (iv) blocking mineralocorticoid receptors, known not to be involved in behavioural immobility in the forced swim test, did not affect forced swimming-evoked histone H3 phospho-acetylation in dentate neurons; and (v) the pharmacological manipulations and gene deletions did not affect behaviour in the initial forced swim test. We conclude that the forced swimming-induced behavioural immobility response requires histone H3 phospho-acetylation and c-Fos induction in distinct dentate granule neurons through recruitment of the NMDA/ERK/MSK 1/2 pathway.

Control system for a 373 kW, intercooled, two-spool gas turbine engine powering a hybrid electric world sports car class vehicle

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

Shortlidge, C.C.

SatCon technology Corporation has completed design, fabrication, and the first round of test of a 373 kW (500 hp), two-spool, intercooled gas turbine engine with integral induction type alternators. This turbine alternator is the prime mover for a World Sports Car class hybrid electric vehicle under development by Chrysler Corporation. The complete hybrid electric vehicle propulsion system features the 373 kW (500 hp) turbine alternator unit, a 373 kW (500 hp) 3.25 kW-h (4.36 hp-h) flywheel, a 559 kW (750 hp) traction motor, and the propulsion system control system. This paper presents and discusses the major attributes of the controlmore » system associated with the turbine alternator unit. Also discussed is the role and operational requirements of the turbine unit as part of the complete hybrid electric vehicle propulsion system.« less

Integrated Inverter For Driving Multiple Electric Machines

DOEpatents

Su, Gui-Jia [Knoxville, TN; Hsu, John S [Oak Ridge, TN

2006-04-04

An electric machine drive (50) has a plurality of inverters (50a, 50b) for controlling respective electric machines (57, 62), which may include a three-phase main traction machine (57) and two-phase accessory machines (62) in a hybrid or electric vehicle. The drive (50) has a common control section (53, 54) for controlling the plurality of inverters (50a, 50b) with only one microelectronic processor (54) for controlling the plurality of inverters (50a, 50b), only one gate driver circuit (53) for controlling conduction of semiconductor switches (S1-S10) in the plurality of inverters (50a, 50b), and also includes a common dc bus (70), a common dc bus filtering capacitor (C1) and a common dc bus voltage sensor (67). The electric machines (57, 62) may be synchronous machines, induction machines, or PM machines and may be operated in a motoring mode or a generating mode.

Mechanical obstruction to ventilation from an ovarian cyst during pregnancy.

PubMed

Beng, D T; Choon, L T

1991-05-01

This report documents the danger of the gravid uterus fixing a large ovarian cyst in a position disadvantageous to diaphragmatic excursion and thereby obstructing ventilation. A 34-year-old pregnant patient presented at 18 weeks amenorrhoea with a large ovarian cyst. She gave a history of exertional dyspnoea and orthopnoea. Clinical examination revealed a grossly enlarged abdomen and a respiratory rate of 28 breaths.min-1. Intraoperatively, ventilation was markedly impaired resulting in cyanosis and bradycardia. This was relieved by drainage of the ovarian cyst. A left lateral tilt with manual traction on the tumour may have avoided this problem. Should the above measures be inadequate, immediate drainage of the cyst is essential. Severe respiratory distress may require ultrasound-guided, percutaneous, aspiration of the cyst preoperatively. However, as in this patient, the absence of gross signs of respiratory failure does not preclude acute ventilatory failure after induction of anaesthesia.

Direct hip joint distraction during acetabular fracture surgery using the AO universal manipulator.

PubMed

Calafi, L Afshin; Routt, M L Chip

2010-02-01

Certain acetabular fractures may necessitate distraction of the hip joint for removal of intra-articular debris and assessment of reduction. Distraction can be accomplished by manual traction, using a traction table or an AO universal manipulator (UM). The UM is a relatively simple and an inexpensive device that can provide focal distraction in a controlled manner without the risks associated with the use of a traction table. We describe a technique using the UM for hip joint distraction during acetabular fracture surgery through a Kocher-Langenbeck surgical exposure.

Contraintes residuelles et leurs impacts sur l'amorcage de fissures en fatigue de flexion dans des engrenages aeronautiques durcis superficiellement par induction

NASA Astrophysics Data System (ADS)

Savaria, Vincent

The optimization of gearing for aeronautical engines depends on the development of surface hardening processes to significantly improve in-service durability. Induction heating followed by quenching is a treatment increasingly used in this field to improve the fatigue resistance of critical components such as gears. In this context, this thesis studies the impact of the induction process parameters on residual stresses and the effects of those stresses on the bending fatigue of induction hardened gears. Two existing residual stress measurement techniques, X-ray diffraction and the contour method, were adapted for induction hardened components. The residual stress measurement by X-ray diffraction technique has been significantly improved in this thesis by the consideration of the variation of the X-ray elastic constant at different locations in the hardened layer and the development of a finite element based layer removal correction method that enabled more accurate in-depth residual stress measurements in all sort of geometries. The contour method is clearly a powerful tool for residual stress mapping at the core of parts but proved to be inaccurate for near-surface measurements in the case of thin hardened layers. These methods were used to show the effects of several parameters (initial hardness, preheating, final heating, tempering) with discs and aeronautical spur gears. The results indicate that two induction treatments can sometimes produce two different residual stress distributions (amplitude, severity of gradient in the transition zone, etc.) for a similar hardened depth. The bending fatigue of those gears was studied experimentally with a single tooth bending test rig and numerically with the proposition of a fatigue model for the calculation of the bending endurance limit. The calibration of the model was based on fatigue tests results on traction and torsion specimens. Bending fatigue testing results on gears confirmed the overall accuracy of the proposed model predictions. The Crossland criterion without the gradient effect gave better predictions when compared with the experimental results for that particular case. This 3D multiaxial fatigue prediction model represents a significant improvement over previous approaches by the simultaneous consideration of the so-called gradient effect, residual stresses, surface roughness and the variation of properties caused by the surface hardening. The induction treatments used in this study improved the bending fatigue resistance of spur gears by 45 to 71 % depending on the case.

A modification of the maitland roll top traction table.

PubMed

Kneipp, K

1975-03-01

This modification of the Maitland Roll Top Traction Table (Maitland, 1973) differs from the original as follows: 1. The two weight-bearing leaves are enclosed by a "guide frame" and the "U-piece" of the original is replaced by a hinged "gate" at the foot, which can be opened downwards for lumbar traction, or can be locked to restrain the leaves when the table is required for other purposes. 2. Four rollers of light steel replace the wooden dowels. 3. The modified table in use by the author is held by a floor peg, and is set up be-between two walls 10' 6″ apart which provide purchase points for traction. Alternatively, purchase at the head end can be taken by hooks attached to the table itself. 4. The design permits a six-foot plinth to be used. Copyright © 1975 Australian Physiotherapy Association. Published by . All rights reserved.

Traction studies of piston ring wear using an external radiometric method with proton activation

NASA Astrophysics Data System (ADS)

Scharf, Waldemar; Niewczas, Andrzej

1987-04-01

A method and results are presented of traction studies of piston ring wear in a Polski Fiat 126p passenger car and Star 200 lorry. The rings sliding surface was activated with a beam of 9.6-MeV protons and the measurements were made using a collimated scintillation detector placed outside the engine, i.e. without interfering with the engine's operation. The cars were run under varying traction conditions, their mileages having ranged between 7000 and 12000 km. In stable wear conditions on the road the piston ring wear for the passenger car and the lorry was {0.28%}/{100} km and {0.045%}/{100} km, respectively. The method was found to be particularly suitable for traction studies because it is simple and cheap. It can be employed as early as after the first 100 km of the car mileage.

[The application of delayed skin grafting combined traction in severe joint cicatricial contracture].

PubMed

Xu, Zihan; Zhang, Zhenxin; Wang, Benfeng; Sun, Yaowen; Guo, Yadong; Gao, Wenjie; Qin, Gaoping

2014-11-01

To investigate the effect of delayed skin grafting combined traction in severe joint cicatricial contracture. At the first stage, the joint cicatricial contracture was released completely with protection of vessels, nerves and tendons. The wound was covered with allogenetic skin or biomaterials. After skin traction for 7-14 days, the joint could reach the extension position. Then the skin graft was performed on the wound. 25 cases were treated from Mar. 2000 to May. 2013. Primary healing was achieved at the second stage in all the cases. The skin graft had a satisfactory color and elasticity. Joint function was normal. All the patients were followed up for 3 months to 11 years with no hypertrophic scar and contraction relapse, except for one case who didn' t have enough active exercise on shoulder joint. Delayed skin grafting combined traction can effectively increase the skin graft survival rate and improve the joint function recovery.

Force sensing using 3D displacement measurements in linear elastic bodies

NASA Astrophysics Data System (ADS)

Feng, Xinzeng; Hui, Chung-Yuen

2016-07-01

In cell traction microscopy, the mechanical forces exerted by a cell on its environment is usually determined from experimentally measured displacement by solving an inverse problem in elasticity. In this paper, an innovative numerical method is proposed which finds the "optimal" traction to the inverse problem. When sufficient regularization is applied, we demonstrate that the proposed method significantly improves the widely used approach using Green's functions. Motivated by real cell experiments, the equilibrium condition of a slowly migrating cell is imposed as a set of equality constraints on the unknown traction. Our validation benchmarks demonstrate that the numeric solution to the constrained inverse problem well recovers the actual traction when the optimal regularization parameter is used. The proposed method can thus be applied to study general force sensing problems, which utilize displacement measurements to sense inaccessible forces in linear elastic bodies with a priori constraints.

Traction test of temporary dental cements.

PubMed

Román-Rodríguez, Juan-Luis; Millan-Martínez, Diego; Fons-Font, Antonio; Agustín-Panadero, Rubén; Fernández-Estevan, Lucía

2017-04-01

Classic self-curing temporary cements obstruct the translucence of provisional restorations. New dual-cure esthetic temporary cements need investigation and comparison with classic cements to ensure that they are equally retentive and provide adequate translucence. The objective is to analyze by means of traction testing in a in vitro study the retention of five temporary cements. Ten molars were prepared and ten provisional resin restorations were fabricated using CAD-CAM technology (n=10). Five temporary cements were selected: self-curing temporary cements, Dycal (D), Temp Bond (TB), Temp Bond Non Eugenol (TBNE); dual-curing esthetic cements Temp Bond Clear (TBC) and Telio CS link (TE). Each sample underwent traction testing, both with thermocycling (190 cycles at 5-55º) and without thermocycling. TE and TBC obtained the highest traction resistance values. Thermocycling reduced the resistance of all cements except TBC. The dual-cure esthetic cements tested provided optimum outcomes for bonding provisional restorations. Key words: Temporary dental cements, cements resistance.

Study of dynamic emission spectra from lubricant films in an elastohydrodynamic contact using Fourier transform spectroscopy

NASA Technical Reports Server (NTRS)

Lauer, J. L.

1978-01-01

Infrared emission spectra were obtained through a diamond window from lubricating fluids in an operating sliding elastohydrodynamic contact and analyzed by comparison with static absorption spectra under similar pressures. Different loads, shear rates and temperatures were used. Most of the spectra exhibited polarization characteristics, indicating directional alignment of the lubricant in the EHD contact. Among the fluids studied were a "traction" fluid, an advanced ester, and their mixtures, a synthetic paraffin, a naphthenic reference fluid (N-1), both neat and containing 1 percent of p-tricresyl phosphate as an anti-wear additive, and a C-ether. Traction properties were found to be nearly proportional to mixture composition for traction fluid and ester mixtures. The anti-wear additive reduced traction and fluid temperature under low loads but increased them under higher loads, giving rise to formation of a friction polymer.

System for controlling a hybrid energy system

DOEpatents

Hoff, Brian D.; Akasam, Sivaprasad

2013-01-29

A method includes identifying a first operating sequence of a repeated operation of at least one non-traction load. The method also includes determining first and second parameters respectively indicative of a requested energy and output energy of the at least one non-traction load and comparing the determined first and second parameters at a plurality of time increments of the first operating sequence. The method also includes determining a third parameter of the hybrid energy system indicative of energy regenerated from the at least one non-traction load and monitoring the third parameter at the plurality of time increments of the first operating sequence. The method also includes determining at least one of an energy deficiency or an energy surplus associated with the non-traction load of the hybrid energy system and selectively adjusting energy stored within the storage device during at least a portion of a second operating sequence.

An Inverter Packaging Scheme for an Integrated Segmented Traction Drive System

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

Su, Gui-Jia; Tang, Lixin; Ayers, Curtis William

The standard voltage source inverter (VSI), widely used in electric vehicle/hybrid electric vehicle (EV/HEV) traction drives, requires a bulky dc bus capacitor to absorb the large switching ripple currents and prevent them from shortening the battery s life. The dc bus capacitor presents a significant barrier to meeting inverter cost, volume, and weight requirements for mass production of affordable EVs/HEVs. The large ripple currents become even more problematic for the film capacitors (the capacitor technology of choice for EVs/HEVs) in high temperature environments as their ripple current handling capability decreases rapidly with rising temperatures. It is shown in previous workmore » that segmenting the VSI based traction drive system can significantly decrease the ripple currents and thus the size of the dc bus capacitor. This paper presents an integrated packaging scheme to reduce the system cost of a segmented traction drive.« less

The communications industry's requirements and interests. [thunderstorm and lightning data useful to telephone operating companies

NASA Technical Reports Server (NTRS)

Wanaselja, O.

1979-01-01

Of interest to the communications industry are the amplitude, waveshape, duration and frequency of lightning-originated voltage surges and transients on the communications network, including the distribution system and AC power supply circuits. The cloud-to-ground lightning discharge and its characteristics are thought to be most meaningful. Of specific interest are peak current, waveshape, number of flashes, strokes per flash, and zone of influence. Accurate and meaningful lightning data at the local level (telephone district office) is necessary for a decision on the appropriate protection level. In addition to lightning, the protection engineer must consider other factors such as: AC induction, switching surges, ground potential rise, soil resistivity, bonding and grounding techniques, shielding and isolation, and exposure of the telephone loop.

Soap-film flow induced by electric fields in asymmetric frames

NASA Astrophysics Data System (ADS)

Mollaei, S.; Nasiri, M.; Soltanmohammadi, N.; Shirsavar, R.; Ramos, A.; Amjadi, A.

2018-04-01

Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

Soap-film flow induced by electric fields in asymmetric frames.

PubMed

Mollaei, S; Nasiri, M; Soltanmohammadi, N; Shirsavar, R; Ramos, A; Amjadi, A

2018-04-01

Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

An HF coaxial bridge for measuring impedance ratios up to 1 MHz

NASA Astrophysics Data System (ADS)

Kucera, J.; Sedlacek, R.; Bohacek, J.

2012-08-01

A four-terminal pair coaxial ac bridge developed for calibrating both resistance and capacitance ratios and working in the frequency range from 100 kHz up to 1 MHz is described. A reference inductive voltage divider (IVD) makes it possible to calibrate ratios 1:1 and 10:1 with uncertainty of a few parts in 105. The IVD is calibrated by means of a series-parallel capacitance device (SPCD). Use of the same ac bridge with minimal changes for calibrating the SPCD, IVD and unknown impedances simplifies the whole calibration process. The bridge balance conditions are fulfilled with simple capacitance and resistance decades and by injecting voltage supplied from the auxiliary direct digital synthesizer. Bridge performance was checked on the basis of resistance ratio measurements and also capacitance ratio measurements.

Imaging ac losses in superconducting films via scanning Hall probe microscopy

NASA Astrophysics Data System (ADS)

Dinner, Rafael B.; Moler, Kathryn A.; Feldmann, D. Matthew; Beasley, M. R.

2007-04-01

Various local probes have been applied to understanding current flow through superconducting films, which are often surprisingly inhomogeneous. Here, we show that magnetic imaging allows quantitative reconstruction of both current density J and electric field E resolved in time and space in a film carrying subcritical ac current. Current reconstruction entails inversion of the Biot-Savart law, while electric fields are reconstructed using Faraday’s law. We describe the corresponding numerical procedures, largely adapting existing work to the case of a strip carrying ac current, but including other methods of obtaining the complete electric field from the inductive portion determined by Faraday’s law. We also delineate the physical requirements behind the mathematical transformations. We then apply the procedures to images of a strip of YBa2Cu3O7-δ carrying an ac current at 400Hz . Our scanning Hall probe microscope produces a time series of magnetic images of the strip with 1μm spatial resolution and 25μs time resolution. Combining the reconstructed J and E , we obtain a complete characterization including local critical current density, E-J curves, and power losses. This analysis has a range of applications from fundamental studies of vortex dynamics to practical coated conductor development.

Oxaloacetate decreases the infarct size and attenuates the reduction in evoked responses after photothrombotic focal ischemia in the rat cortex.

PubMed

Nagy, David; Marosi, Mate; Kis, Zsolt; Farkas, Tamas; Rakos, Gabriella; Vecsei, Laszlo; Teichberg, Vivian I; Toldi, Jozsef

2009-09-01

A traumatic brain injury or a focal brain lesion is followed by acute excitotoxicity caused by the presence of abnormally high glutamate (Glu) levels in the cerebrospinal and interstitial fluids. It has recently been demonstrated that this excess Glu in the brain can be eliminated into the blood following the intravenous administration of oxaloacetate (OxAc), which, by scavenging the blood Glu, induces an enhanced and neuroprotective brain-to-blood Glu efflux. In this study, we subjected rats to a photothrombotic lesion and treated them after the illumination with a single 30-min-long administration of OxAc (1.2 mg/100 g, i.v.). Following induction of the lesion, we measured the infarct size and the amplitudes of the somatosensory evoked potentials (SEPs) as recorded from the skull surface. The photothrombotic lesion resulted in appreciably decreased amplitudes of the evoked potentials, but OxAc administration significantly attenuated this reduction, and also the infarct size assessed histologically. We suggest that the neuroprotective effects of OxAc are due to its blood Glu-scavenging activity, which, by increasing the brain-to-blood Glu efflux, reduces the excess Glu responsible for the anatomical and functional correlates of the ischemia, as evaluated by electrophysiological evoked potential (EP) measurements.

Method and apparatus for pulse width modulation control of an AC induction motor

DOEpatents

Geppert, Steven; Slicker, James M.

1984-01-01

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

A Differential Monolithically Integrated Inductive Linear Displacement Measurement Microsystem

PubMed Central

Podhraški, Matija; Trontelj, Janez

2016-01-01

An inductive linear displacement measurement microsystem realized as a monolithic Application-Specific Integrated Circuit (ASIC) is presented. The system comprises integrated microtransformers as sensing elements, and analog front-end electronics for signal processing and demodulation, both jointly fabricated in a conventional commercially available four-metal 350-nm CMOS process. The key novelty of the presented system is its full integration, straightforward fabrication, and ease of application, requiring no external light or magnetic field source. Such systems therefore have the possibility of substituting certain conventional position encoder types. The microtransformers are excited by an AC signal in MHz range. The displacement information is modulated into the AC signal by a metal grating scale placed over the microsystem, employing a differential measurement principle. Homodyne mixing is used for the demodulation of the scale displacement information, returned by the ASIC as a DC signal in two quadrature channels allowing the determination of linear position of the target scale. The microsystem design, simulations, and characterization are presented. Various system operating conditions such as frequency, phase, target scale material and distance have been experimentally evaluated. The best results have been achieved at 4 MHz, demonstrating a linear resolution of 20 µm with steel and copper scale, having respective sensitivities of 0.71 V/mm and 0.99 V/mm. PMID:26999146

A Differential Monolithically Integrated Inductive Linear Displacement Measurement Microsystem.

PubMed

Podhraški, Matija; Trontelj, Janez

2016-03-17

An inductive linear displacement measurement microsystem realized as a monolithic Application-Specific Integrated Circuit (ASIC) is presented. The system comprises integrated microtransformers as sensing elements, and analog front-end electronics for signal processing and demodulation, both jointly fabricated in a conventional commercially available four-metal 350-nm CMOS process. The key novelty of the presented system is its full integration, straightforward fabrication, and ease of application, requiring no external light or magnetic field source. Such systems therefore have the possibility of substituting certain conventional position encoder types. The microtransformers are excited by an AC signal in MHz range. The displacement information is modulated into the AC signal by a metal grating scale placed over the microsystem, employing a differential measurement principle. Homodyne mixing is used for the demodulation of the scale displacement information, returned by the ASIC as a DC signal in two quadrature channels allowing the determination of linear position of the target scale. The microsystem design, simulations, and characterization are presented. Various system operating conditions such as frequency, phase, target scale material and distance have been experimentally evaluated. The best results have been achieved at 4 MHz, demonstrating a linear resolution of 20 µm with steel and copper scale, having respective sensitivities of 0.71 V/mm and 0.99 V/mm.

Method and apparatus for pulse width modulation control of an AC induction motor

NASA Technical Reports Server (NTRS)

Geppert, Steven (Inventor); Slicker, James M. (Inventor)

1984-01-01

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.

Differential Interaction of Synthetic Glycolipids with Biomimetic Plasma Membrane Lipids Correlates with the Plant Biological Response.

PubMed

Nasir, Mehmet Nail; Lins, Laurence; Crowet, Jean-Marc; Ongena, Marc; Dorey, Stephan; Dhondt-Cordelier, Sandrine; Clément, Christophe; Bouquillon, Sandrine; Haudrechy, Arnaud; Sarazin, Catherine; Fauconnier, Marie-Laure; Nott, Katherine; Deleu, Magali

2017-09-26

Natural and synthetic amphiphilic molecules including lipopeptides, lipopolysaccharides, and glycolipids are able to induce defense mechanisms in plants. In the present work, the perception of two synthetic C14 rhamnolipids, namely, Alk-RL and Ac-RL, differing only at the level of the lipid tail terminal group have been investigated using biological and biophysical approaches. We showed that Alk-RL induces a stronger early signaling response in tobacco cell suspensions than does Ac-RL. The interactions of both synthetic RLs with simplified biomimetic membranes were further analyzed using experimental and in silico approaches. Our results indicate that the interactions of Alk-RL and Ac-RL with lipids were different in terms of insertion and molecular responses and were dependent on the lipid composition of model membranes. A more favorable insertion of Alk-RL than Ac-RL into lipid membranes is observed. Alk-RL forms more stable molecular assemblies than Ac-RL with phospholipids and sterols. At the molecular level, the presence of sterols tends to increase the RLs' interaction with lipid bilayers, with a fluidizing effect on the alkyl chains. Taken together, our findings suggest that the perception of these synthetic RLs at the membrane level could be related to a lipid-driven process depending on the organization of the membrane and the orientation of the RLs within the membrane and is correlated with the induction of early signaling responses in tobacco cells.

Cell prestress. II. Contribution of microtubules

NASA Technical Reports Server (NTRS)

Stamenovic, Dimitrije; Mijailovich, Srboljub M.; Tolic-Norrelykke, Iva Marija; Chen, Jianxin; Wang, Ning; Ingber, D. E. (Principal Investigator)

2002-01-01

The tensegrity model hypothesizes that cytoskeleton-based microtubules (MTs) carry compression as they balance a portion of cell contractile stress. To test this hypothesis, we used traction force microscopy to measure traction at the interface of adhering human airway smooth muscle cells and a flexible polyacrylamide gel substrate. The prediction is that if MTs balance a portion of contractile stress, then, upon their disruption, the portion of stress balanced by MTs would shift to the substrate, thereby causing an increase in traction. Measurements were done first in maximally activated cells (10 microM histamine) and then again after MTs had been disrupted (1 microM colchicine). We found that after disruption of MTs, traction increased on average by approximately 13%. Because in activated cells colchicine induced neither an increase in intracellular Ca(2+) nor an increase in myosin light chain phosphorylation as shown previously, we concluded that the observed increase in traction was a result of load shift from MTs to the substrate. In addition, energy stored in the flexible substrate was calculated as work done by traction on the deformation of the substrate. This result was then utilized in an energetic analysis. We assumed that cytoskeleton-based MTs are slender elastic rods supported laterally by intermediate filaments and that MTs buckle as the cell contracts. Using the post-buckling equilibrium theory of Euler struts, we found that energy stored during buckling of MTs was quantitatively consistent with the measured increase in substrate energy after disruption of MTs. This is further evidence supporting the idea that MTs are intracellular compression-bearing elements.

3.0T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging-A preliminary study.

PubMed

Jungmann, Pia M; Baum, Thomas; Schaeffeler, Christoph; Sauerschnig, Martin; Brucker, Peter U; Mann, Alexander; Ganter, Carl; Bieri, Oliver; Rummeny, Ernst J; Woertler, Klaus; Bauer, Jan S

2015-08-01

To determine the impact of axial traction during high resolution 3.0T MR imaging of the ankle on morphological assessment of articular cartilage and quantitative cartilage imaging parameters. MR images of n=25 asymptomatic ankles were acquired with and without axial traction (6kg). Coronal and sagittal T1-weighted (w) turbo spin echo (TSE) sequences with a driven equilibrium pulse and sagittal fat-saturated intermediate-w (IMfs) TSE sequences were acquired for morphological evaluation on a four-point scale (1=best, 4=worst). For quantitative assessment of cartilage degradation segmentation was performed on 2D multislice-multiecho (MSME) SE T2, steady-state free-precession (SSFP; n=8) T2 and SSFP diffusion-weighted imaging (DWI; n=8) images. Wilcoxon-tests and paired t-tests were used for statistical analysis. With axial traction, joint space width increased significantly and delineation of cartilage surfaces was rated superior (P<0.05). Cartilage surfaces were best visualized on coronal T1-w images (P<0.05). Differences for cartilage matrix evaluation were smaller. Subchondral bone evaluation, motion artifacts and image quality were not significantly different between the acquisition methods (P>0.05). T2 values were lower at the tibia than at the talus (P<0.001). Reproducibility was better for images with axial traction. Axial traction increased the joint space width, allowed for better visualization of cartilage surfaces and improved compartment discrimination and reproducibility of quantitative cartilage parameters. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cost effectiveness of using surgery versus skeletal traction in management of femoral shaft fractures at Thika level 5 hospital, Kenya.

PubMed

Opondo, Everisto; Wanzala, Peter; Makokha, Ansellimo

2013-01-01

A prospective quasi experimental study was undertaken at the Thika level 5 hospital. The study aimed to compare the costs of managing femoral shaft fracture by surgery as compared to skeletal traction. Sixty nine (46.6%) patients were enrolled in group A and managed surgically by intramedullary nailing while 79 (53.4%) patients were enrolled in group B and managed by skeletal traction. Exclusion criteria included patients with pathological fractures and previous femoral fractures. Data was collected by evaluation of patients in patient bills using a standardized questionnaire. The questionnaire included cost of haematological and radiological tests, bed fees, theatre fees and physiotherapy costs. The data was compiled and analyzed using SPSS version 16. Person's chi square and odds ratios were used to measure associations and risk analysis respectively. A higher proportion of patients (88.4%) in group A were hospitalized for less than one month compared to 20 patients (30.4%) in group B (p, 0.001).Total cost of treatment in group A was significantly lower than in group B. Nineteen (27.9%) patients who underwent surgery paid a total bill of Ksh 5000-7500 compared to 7(10.4%) who were treated by traction. The financial cost benefit of surgery was further complimented by better functional outcomes. The data indicates a cost advantage of managing femoral shaft fracture by surgery compared to traction. Furthermore the longer hospital stay in the traction group is associated with more malunion, limb deformity and shortening.

Earthquake fracture energy inferred from kinematic rupture models on extended faults

USGS Publications Warehouse

Tinti, E.; Spudich, P.; Cocco, M.

2005-01-01

We estimate fracture energy on extended faults for several recent earthquakes by retrieving dynamic traction evolution at each point on the fault plane from slip history imaged by inverting ground motion waveforms. We define the breakdown work (Wb) as the excess of work over some minimum traction level achieved during slip. Wb is equivalent to "seismological" fracture energy (G) in previous investigations. Our numerical approach uses slip velocity as a boundary condition on the fault. We employ a three-dimensional finite difference algorithm to compute the dynamic traction evolution in the time domain during the earthquake rupture. We estimate Wb by calculating the scalar product between dynamic traction and slip velocity vectors. This approach does not require specifying a constitutive law and assuming dynamic traction to be collinear with slip velocity. If these vectors are not collinear, the inferred breakdown work depends on the initial traction level. We show that breakdown work depends on the square of slip. The spatial distribution of breakdown work in a single earthquake is strongly correlated with the slip distribution. Breakdown work density and its integral over the fault, breakdown energy, scale with seismic moment according to a power law (with exponent 0.59 and 1.18, respectively). Our estimates of breakdown work range between 4 ?? 105 and 2 ?? 107 J/m2 for earthquakes having moment magnitudes between 5.6 and 7.2. We also compare our inferred values with geologic surface energies. This comparison might suggest that breakdown work for large earthquakes goes primarily into heat production. Copyright 2005 by the American Geophysical Union.

Permanent magnet motors

NASA Astrophysics Data System (ADS)

Richter, E.

1984-09-01

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

An SCR inverter for electric vehicles

NASA Technical Reports Server (NTRS)

Latos, T.; Bosack, D.; Ehrlich, R.; Jahns, T.; Mezera, J.; Thimmesch, D.

1980-01-01

An inverter for an electric vehicle propulsion application has been designed and constructed to excite a polyphase induction motor from a fixed propulsion battery source. The inverter, rated at 35kW peak power, is fully regenerative and permits vehicle operation in both the forward and reverse directions. Thyristors are employed as the power switching devices arranged in a dc bus commutated topology. This paper describes the major role the controller plays in generating the motor excitation voltage and frequency to deliver performance similar to dc systems. Motoring efficiency test data for the controller are presented. It is concluded that an SCR inverter in conjunction with an ac induction motor is a viable alternative to present dc vehicle propulsion systems on the basis of performance and size criteria.

FGFR1 is essential for N-acetyl-seryl-aspartyl-lysyl-proline regulation of mitochondrial dynamics by upregulating microRNA let-7b-5p.

PubMed

Hu, Qiongying; Li, Jinpeng; Nitta, Kyoko; Kitada, Munehiro; Nagai, Takako; Kanasaki, Keizo; Koya, Daisuke

2018-01-15

Fibroblast growth factor receptor (FGFR) 1 plays a key role in endothelial homeostasis by inducing microRNA (miR) let-7. Our previous paper showed that anti-fibrotic effects of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) were associated with restoring diabetes-suppressed expression of FGFR1 and miR let-7, the key contributor of mitochondrial biogenesis, which is regulated by mitochondrial membrane GTPase proteins (MFN2 and OPA1). Here, we found that the FGFR1 signaling pathway was critical for AcSDKP in maintaining endothelial mitochondrial biogenesis through induction of miR let-7b-5p. In endothelial cells, AcSDKP restored the triple cytokines (TGF-β2, interleukin-1β, tumor necrosis factor-α)-suppressed miR let-7b-5p and protein levels of the mitochondrial membrane GTPase. This effect of AcSDKP was lost with either fibroblast growth factor receptor substrate 2 (FRS2) siRNA or neutralizing FGFR1-treated cells. Similarly, AcSDKP had no effect on the miR let-7b-5p inhibitor-suppressed GTPase levels in endothelial cells. In addition, a miR let-7b-5p mimic restored the levels of FRS2 siRNA-reduced GTPases in endothelial cells. These findings were also confirmed using MitoTracker Green and an immunofluorescence assay. Our results demonstrated that the AcSDKP-FGFR1 signaling pathway is critical for maintaining mitochondrial dynamics by control of miR let-7b-5p in endothelial cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Time to consider the contact force during photoplethysmography measurement during pediatric anesthesia: A prospective, nonrandomized interventional study.

PubMed

Lee, Ji-Hyun; Yang, Seungman; Park, Jonghyun; Kim, Hee Chan; Kim, Eun-Hee; Jang, Young-Eun; Kim, Jin-Tae; Kim, Hee-Soo

2018-06-19

Respiratory variations in photoplethysmography amplitude enable volume status assessment. However, the contact force between the measurement site and sensor can affect photoplethysmography waveforms. We aimed to evaluate contact force effects on respiratory variations in photoplethysmography waveforms in children under general anesthesia. Children aged 3-5 years were enrolled. After anesthetic induction, mechanical ventilation commenced at a tidal volume of 10 mL/kg. Photoplethysmographic signals were obtained in the supine position from the index finger using a force sensor-integrated clip-type photoplethysmography sensor that increased the contact force from 0-1.4 N for 20 respiratory cycles at each force. The AC amplitude (pulsatile component), DC amplitude (nonpulsatile component), AC/DC ratio, and respiratory variations in photoplethysmography amplitude were calculated. Data from 34 children were analyzed. Seven contact forces at 0.2-N increments were evaluated for each patient. The normalized AC amplitude increased maximally at a contact force of 0.4-0.6 N and decreased with increasing contact force. However, the normalized DC amplitude increased with a contact force exceeding 0.4 N. ΔPOP decreased slightly and increased from the point when the AC amplitude started to decrease as contact force increased. In a 0.2-1.2 N contact force range, significant changes in the normalized AC amplitude, normalized DC amplitude, AC/DC ratio, and respiratory variations in photoplethysmography amplitude were observed. Respiratory variations in photoplethysmography amplitude changed according to variable contact forces; therefore, these measurements may not reflect respiration-induced stroke volume variations. Clinicians should consider contact force bias when interpreting morphological data from photoplethysmography signals. © 2018 John Wiley & Sons Ltd.

A novel anchorage technique for transnasal traction in rigid external maxillary distraction.

PubMed

Varol, A; Basa, S

2013-12-01

We describe an effective technique for anchorage of transnasal traction in the management of maxillary rotation during external distraction. Copyright © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Multiroller traction drive speed reducer: Evaluation for automotive gas turbine engine

NASA Technical Reports Server (NTRS)

Rohn, D. A.; Anderson, N. E.; Loewenthal, S. H.

1982-01-01

Tests were conducted on a nominal 14:1 fixed-ratio Nasvytis multiroller traction drive retrofitted as the speed reducer in an automotive gas turbine engine. Power turbine speeds of 45,000 rpm and a drive output power of 102 kW (137 hp) were reached. The drive operated under both variable roller loading (proportional to torque) and fixed roller loading (automatic loading mechanism locked). The drive operated smoothly and efficiently as the engine speed reducer. Engine specific fuel consumption with the traction speed reducer was comparable to that with the original helical gearset.

Review of factors affecting aircraft wet runway performance

NASA Technical Reports Server (NTRS)

Yager, T. J.

1983-01-01

Problems associated with aircraft operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from investigations conducted at the Langley Aircraft Landing Loads and Traction Facility and from tests with instrumented ground vehicles and aircraft are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

Candidate Coatings and Dry Traction Drives for Planetary Vehicles

NASA Technical Reports Server (NTRS)

Fusaro, Robert; Oswald, Fred B.

2002-01-01

Robert Fusaro and Fred Oswald of the Mechanical Components Branch discussed 'Candidate Coatings and Dry Traction Drives for Planetary Vehicles'. Vehicles to be designed for exploration of planets and moons of the solar system will require reliable mechanical drives to operate efficiently. Long-term operation of these drives will be challenging because of extreme operating conditions. These extreme conditions include: very high and/or very cold temperatures, wide temperature ranges, dust, vacuum or low-pressure atmospheres, and corrosive environments. Most drives used on Earth involve oil-lubricated gears. However, due to the extreme conditions on planetary surfaces, it may not be advisable or even possible to use oil lubrication. Unfortunately, solid lubricants do not work well when applied to gears because of the high contact stress conditions and large sliding motion between the teeth, which cause wear and limit life. We believe traction drives will provide an attractive alternative to gear drives. Traction drives are composed of rollers that provide geometry more conducive to solid lubrication. Minimal slip occurs in this contact geometry and thus there is very low wear to the solid lubricant. The challenge for these solid-lubricated drives is finding materials or coatings that provide the required long-life while also providing high traction. We seek materials that provide low wear with high friction.

Force generation by groups of migrating bacteria

PubMed Central

Koch, Matthias D.; Liu, Guannan; Stone, Howard A.; Shaevitz, Joshua W.

2017-01-01

From colony formation in bacteria to wound healing and embryonic development in multicellular organisms, groups of living cells must often move collectively. Although considerable study has probed the biophysical mechanisms of how eukaryotic cells generate forces during migration, little such study has been devoted to bacteria, in particular with regard to the question of how bacteria generate and coordinate forces during collective motion. This question is addressed here using traction force microscopy. We study two distinct motility mechanisms of Myxococcus xanthus, namely, twitching and gliding. For twitching, powered by type-IV pilus retraction, we find that individual cells exert local traction in small hotspots with forces on the order of 50 pN. Twitching bacterial groups also produce traction hotspots, but with forces around 100 pN that fluctuate rapidly on timescales of <1.5 min. Gliding, the second motility mechanism, is driven by lateral transport of substrate adhesions. When cells are isolated, gliding produces low average traction on the order of 1 Pa. However, traction is amplified approximately fivefold in groups. Advancing protrusions of gliding cells push, on average, in the direction of motion. Together, these results show that the forces generated during twitching and gliding have complementary characters, and both forces have higher values when cells are in groups. PMID:28655845

Force generation by groups of migrating bacteria.

PubMed

Sabass, Benedikt; Koch, Matthias D; Liu, Guannan; Stone, Howard A; Shaevitz, Joshua W

2017-07-11

From colony formation in bacteria to wound healing and embryonic development in multicellular organisms, groups of living cells must often move collectively. Although considerable study has probed the biophysical mechanisms of how eukaryotic cells generate forces during migration, little such study has been devoted to bacteria, in particular with regard to the question of how bacteria generate and coordinate forces during collective motion. This question is addressed here using traction force microscopy. We study two distinct motility mechanisms of Myxococcus xanthus , namely, twitching and gliding. For twitching, powered by type-IV pilus retraction, we find that individual cells exert local traction in small hotspots with forces on the order of 50 pN. Twitching bacterial groups also produce traction hotspots, but with forces around 100 pN that fluctuate rapidly on timescales of <1.5 min. Gliding, the second motility mechanism, is driven by lateral transport of substrate adhesions. When cells are isolated, gliding produces low average traction on the order of 1 Pa. However, traction is amplified approximately fivefold in groups. Advancing protrusions of gliding cells push, on average, in the direction of motion. Together, these results show that the forces generated during twitching and gliding have complementary characters, and both forces have higher values when cells are in groups.

Safety and efficacy of endoscopic submucosal dissection using IT knife nano with clip traction method for early esophageal squamous cell carcinoma.

PubMed

Kitagawa, Yoshiyasu; Suzuki, Takuto; Hara, Taro; Yamaguchi, Taketo

2018-01-01

Although endoscopic submucosal dissection (ESD) is an accepted and established treatment for early esophageal squamous cell carcinoma (EESCC), it is technically difficult, time consuming, and less safe than endoscopic mucosal resection. To perform ESD safely and more efficiently, we proposed a new technique of esophageal ESD using an IT knife nano with the clip traction method. This study aimed to evaluate the efficacy and safety of ESD using this new technique. We retrospectively reviewed all consecutive cases of esophageal ESD performed using an IT knife nano with the clip traction method at our hospital between March 2013 and January 2017. Therapeutic efficacy and safety were also assessed. A total of 103 patients underwent esophageal ESD using the IT knife nano with the clip traction method. In all cases, we performed en bloc resection. Complete resection was achieved in 100 cases (97.1%). The median operating time was 40 (range 13-230) min. No cases of perforation or delayed bleeding occurred. Although two cases (2.0%) of mediastinal emphysema occurred without visible perforation at endoscopy, all were successfully managed conservatively. The new technique of esophageal ESD using the IT knife nano with the clip traction method appears to be feasible, effective, and safe for EESCC treatment.

Solid lubrication design methodology, phase 2

NASA Technical Reports Server (NTRS)

Pallini, R. A.; Wedeven, L. D.; Ragen, M. A.; Aggarwal, B. B.

1986-01-01

The high temperature performance of solid lubricated rolling elements was conducted with a specially designed traction (friction) test apparatus. Graphite lubricants containing three additives (silver, phosphate glass, and zinc orthophosphate) were evaluated from room temperature to 540 C. Two hard coats were also evaluated. The evaluation of these lubricants, using a burnishing method of application, shows a reasonable transfer of lubricant and wear protection for short duration testing except in the 200 C temperature range. The graphite lubricants containing silver and zinc orthophosphate additives were more effective than the phosphate glass material over the test conditions examined. Traction coefficients ranged from a low of 0.07 to a high of 0.6. By curve fitting the traction data, empirical equations for slope and maximum traction coefficient as a function of contact pressure (P), rolling speed (U), and temperature (T) can be developed for each lubricant. A solid lubricant traction model was incorporated into an advanced bearing analysis code (SHABERTH). For comparison purposes, preliminary heat generation calculations were made for both oil and solid lubricated bearing operation. A preliminary analysis indicated a significantly higher heat generation for a solid lubricated ball bearing in a deep groove configuration. An analysis of a cylindrical roller bearing configuration showed a potential for a low friction solid lubricated bearing.

Two-Stage Thoracoscopic Repair of Long-Gap Esophageal Atresia Using Internal Traction Is Safe and Feasible.

PubMed

Tainaka, Takahisa; Uchida, Hiroo; Tanano, Akihide; Shirota, Chiyoe; Hinoki, Akinari; Murase, Naruhiko; Yokota, Kazuki; Oshima, Kazuo; Shirotsuki, Ryo; Chiba, Kosuke; Amano, Hizuru; Kawashima, Hiroshi; Tanaka, Yujiro

2017-01-01

The treatment of long-gap esophageal atresia remains an issue for pediatric surgeons. Many techniques for treating long-gap esophageal atresia have been proposed, but the optimal method has not been established. The thoracoscopic esophageal elongation technique has recently been developed. We previously reported a case in which two-stage thoracoscopic repair was performed using internal esophageal traction without esophageal tearing, and we retrospectively reviewed the outcomes of this procedure in this study. Five patients underwent thoracoscopic treatment involving internal esophageal traction for esophageal atresia involving a long gap or vascular ring over a 5-year period. Between November 2010 and November 2015, 5 patients were treated with thoracoscopic traction. All of these patients successfully underwent thoracoscopic-delayed primary anastomosis. Conversion to open thoracotomy was not required in any case. The postoperative complications experienced by the patients included minor anastomotic leakage in 2 cases, anastomotic stenosis in 1 case, gastroesophageal reflux (GER) in 4 cases, and a hiatal hernia in 1 case. None of the patients died. Two-stage thoracoscopic repair for esophageal atresia involving a long gap or vascular ring is a safe and feasible procedure; however, we must develop methods for treating minor anastomotic complications and GER due to esophageal traction in future.

Roles of calcium/calmodulin-dependent kinase II in long-term memory formation in crickets.

PubMed

Mizunami, Makoto; Nemoto, Yuko; Terao, Kanta; Hamanaka, Yoshitaka; Matsumoto, Yukihisa

2014-01-01

Ca(2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) is a key molecule in many systems of learning and memory in vertebrates, but roles of CaMKII in invertebrates have not been characterized in detail. We have suggested that serial activation of NO/cGMP signaling, cyclic nucleotide-gated channel, Ca(2+)/CaM and cAMP signaling participates in long-term memory (LTM) formation in olfactory conditioning in crickets, and here we show participation of CaMKII in LTM formation and propose its site of action in the biochemical cascades. Crickets subjected to 3-trial conditioning to associate an odor with reward exhibited memory that lasts for a few days, which is characterized as protein synthesis-dependent LTM. In contrast, animals subjected to 1-trial conditioning exhibited memory that lasts for only several hours (mid-term memory, MTM). Injection of a CaMKII inhibitor prior to 3-trial conditioning impaired 1-day memory retention but not 1-hour memory retention, suggesting that CaMKII participates in LTM formation but not in MTM formation. Animals injected with a cGMP analogue, calcium ionophore or cAMP analogue prior to 1-trial conditioning exhibited 1-day retention, and co-injection of a CaMKII inhibitor impaired induction of LTM by the cGMP analogue or that by the calcium ionophore but not that by the cAMP analogue, suggesting that CaMKII is downstream of cGMP production and Ca(2+) influx and upstream of cAMP production in biochemical cascades for LTM formation. Animals injected with an adenylyl cyclase (AC) activator prior to 1-trial conditioning exhibited 1-day retention. Interestingly, a CaMKII inhibitor impaired LTM induction by the AC activator, although AC is expected to be a downstream target of CaMKII. The results suggest that CaMKII interacts with AC to facilitate cAMP production for LTM formation. We propose that CaMKII serves as a key molecule for interplay between Ca(2+) signaling and cAMP signaling for LTM formation, a new role of CaMKII in learning and memory.

Somatic embryogenesis in Carica papaya as affected by auxins and explants, and morphoanatomical-related aspects.

PubMed

Cipriano, Jamile L D; Cruz, Ana Cláudia F; Mancini, Karina C; Schmildt, Edilson R; Lopes, José Carlos; Otoni, Wagner C; Alexandre, Rodrigo S

2018-01-01

The aim of this study was to evaluate somatic embryogenesis in juvenile explants of the THB papaya cultivar. Apical shoots and cotyledonary leaves were inoculated in an induction medium composed of different concentrations of 2,4-D (6, 9, 12, 15 and 18 µM) or 4-CPA (19, 22, 25, 28 and 31 µM). The embryogenic calluses were transferred to a maturation medium for 30 days. Histological analysis were done during the induction and scanning electron microscopy after maturing. For both types of auxin, embryogenesis was achieved at higher frequencies with cotyledonary leaves incubated in induction medium than with apical shoots; except for callogenesis. The early-stage embryos (e.g., globular or heart-shape) predominated. Among the auxins, best results were observed in cotyledonary leaves induced with 4-CPA (25 µM). Histological analyses of the cotyledonary leaf-derived calluses confirmed that the somatic embryos (SEs) formed from parenchyma cells, predominantly differentiated via indirect and multicellular origin and infrequently via synchronized embryogenesis. The secondary embryogenesis was observed during induction and maturation phases in papaya THB cultivar. The combination of ABA (0.5 µM) and AC (15 g L-1) in maturation medium resulted in the highest somatic embryogenesis induction frequency (70 SEs callus-1) and the lowest percentage of early germination (4%).

Dual-Shaft Electric Propulsion (DSEP) Technology Development Program

NASA Astrophysics Data System (ADS)

1992-08-01

The background, progress, and current state of the DOE-sponsored Advanced Dual-Shaft Electric Propulsion Technology Development are presented. Three electric-drive vehicles were build as conversions of a commercial gasoline-powered van, using program-designed components and systems as required. The vehicles were tested primarily on dynamometer or test tract. Component and system testing represented a major portion of the development effort. Test data are summarized in this report, and an Appendix contains the final component design specifications. This major programmatic concerns were the traction battery, the battery management system, the dc-to-ac inverter, the drive motor, the transaxle and its ancillary equipment, and the vehicle controller. Additional effort was devoted to vehicle-related equipment: gear selector, power steering, power brakes, accelerator, dashboard instrumentation, and heater. Design, development, and test activities are reported for each of these items, together with an appraisal (lessons learned) and recommendations for possible further work. Other programmatic results include a Cost and Commercialization Analysis, a Reliability and Hazards Analysis Study, Technical Recommendations for Next-Generation Development, and an assessment of overall program efforts.

Study of advanced electric propulsion system concept using a flywheel for electric vehicles

NASA Technical Reports Server (NTRS)

Younger, F. C.; Lackner, H.

1979-01-01

Advanced electric propulsion system concepts with flywheels for electric vehicles are evaluated and it is predicted that advanced systems can provide considerable performance improvement over existing electric propulsion systems with little or no cost penalty. Using components specifically designed for an integrated electric propulsion system avoids the compromises that frequently lead to a loss of efficiency and to inefficient utilization of space and weight. A propulsion system using a flywheel power energy storage device can provide excellent acceleration under adverse conditions of battery degradation due either to very low temperatures or high degrees of discharge. Both electrical and mechanical means of transfer of energy to and from the flywheel appear attractive; however, development work is required to establish the safe limits of speed and energy storage for advanced flywheel designs and to achieve the optimum efficiency of energy transfer. Brushless traction motor designs using either electronic commutation schemes or dc-to-ac inverters appear to provide a practical approach to a mass producible motor, with excellent efficiency and light weight. No comparisons were made with advanced system concepts which do not incorporate a flywheel.

Pore-scale modeling of moving contact line problems in immiscible two-phase flow

NASA Astrophysics Data System (ADS)

Kucala, Alec; Noble, David; Martinez, Mario

2016-11-01

Accurate modeling of moving contact line (MCL) problems is imperative in predicting capillary pressure vs. saturation curves, permeability, and preferential flow paths for a variety of applications, including geological carbon storage (GCS) and enhanced oil recovery (EOR). Here, we present a model for the moving contact line using pore-scale computational fluid dynamics (CFD) which solves the full, time-dependent Navier-Stokes equations using the Galerkin finite-element method. The MCL is modeled as a surface traction force proportional to the surface tension, dependent on the static properties of the immiscible fluid/solid system. We present a variety of verification test cases for simple two- and three-dimensional geometries to validate the current model, including threshold pressure predictions in flows through pore-throats for a variety of wetting angles. Simulations involving more complex geometries are also presented to be used in future simulations for GCS and EOR problems. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Lateral traction

MedlinePlus

... treat or reduce any joint dislocation or bone fracture by applying tension to the leg or arm with weights and pulleys to realign the bone. For example, it may be used to help line up a broken bone while it heals. Traction as a treatment involves the amount of ...

Treatment of Extreme Tuberculous Kyphosis Using Spinal Osteotomy and Halo-Pelvic Traction: A Case Report.

PubMed

Yu, Bin; Zhu, Ke; Zhao, Deng; Wang, Fei; Liang, Yijian

2016-02-01

A case report of treatment of extreme tuberculous kyphosis using spinal osteotomy and halopelvic traction. The aim of this study was to describe the process and outcome of treatment of a case with extreme tuberculous kyphosis using spine osteotomy and halo-pelvic traction. Spinal tuberculosis causes destruction, deformity, and paraplegia. Long-standing kyphosis may progress with growth in children, and produces respiratory insufficiency, and neurologic deficit. Surgery may help to prevent or reverse the neurological deterioration, while improving pulmonary function in cases with significant spinal deformity. Review of records and radiographs. A 24-year-old female with tuberculous angular kyphosis presented with bilateral lower extremities paresis and dyspnea. The vertebral bodies from T3 to T9 were severely destructed, with a Cobb's angle of 180°on radiographs. The total duration of distraction using halopelvic apparatus kept 10 months. During the duration of traction, the patient underwent a posterior release surgery because flexibility of the kyphosis was not sufficient. Pedicle subtraction osteotomy and pedicle screw fixation were performed to achieve final correction when the Cobb's angle decreased to about 80°. After the whole treatment of halopelvic traction and spine ostetomy, the patient's height increased nearly 30 cm, whereas the angular kyphosis was corrected to a Cobb's angle of 30°. The patient had no complication and neurological deterioration during the treatment. Correction angle and good sagittal balance were well maintained in the duration of 2 years' follow-up. The halo-pelvic apparatus produces high corrective forces applied over a long period, and it provides a slow and safe correction of deformity. In cases of extreme kyphotic deformity, halopelvic traction is an appropriate technique, while avoiding many serious complications from a rapid, one-stage correction. N/A.

Substrate Deformation Predicts Neuronal Growth Cone Advance

PubMed Central

Athamneh, Ahmad I.M.; Cartagena-Rivera, Alexander X.; Raman, Arvind; Suter, Daniel M.

2015-01-01

Although pulling forces have been observed in axonal growth for several decades, their underlying mechanisms, absolute magnitudes, and exact roles are not well understood. In this study, using two different experimental approaches, we quantified retrograde traction force in Aplysia californica neuronal growth cones as they develop over time in response to a new adhesion substrate. In the first approach, we developed a novel method, to our knowledge, for measuring traction forces using an atomic force microscope (AFM) with a cantilever that was modified with an Aplysia cell adhesion molecule (apCAM)-coated microbead. In the second approach, we used force-calibrated glass microneedles coated with apCAM ligands to guide growth cone advance. The traction force exerted by the growth cone was measured by monitoring the microneedle deflection using an optical microscope. Both approaches showed that Aplysia growth cones can develop traction forces in the 100–102 nN range during adhesion-mediated advance. Moreover, our results suggest that the level of traction force is directly correlated to the stiffness of the microneedle, which is consistent with a reinforcement mechanism previously observed in other cell types. Interestingly, the absolute level of traction force did not correlate with growth cone advance toward the adhesion site, but the amount of microneedle deflection did. In cases of adhesion-mediated growth cone advance, the mean needle deflection was 1.05 ± 0.07 μm. By contrast, the mean deflection was significantly lower (0.48 ± 0.06 μm) when the growth cones did not advance. Our data support a hypothesis that adhesion complexes, which can undergo micron-scale elastic deformation, regulate the coupling between the retrogradely flowing actin cytoskeleton and apCAM substrates, stimulating growth cone advance if sufficiently abundant. PMID:26445437

Active management of the third stage of labor with and without controlled cord traction: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Du, Yongming; Ye, Man; Zheng, Feiyun

2014-07-01

To determine the specific effect of controlled cord traction in the third stage of labor in the prevention of postpartum hemorrhage. We searched PubMed, Scopus and Web of Science (inception to 30 October 2013). Randomized controlled trials comparing controlled cord traction with hands-off management in the third stage of labor were included. Five randomized controlled trials involving a total of 30 532 participants were eligible. No significant difference was found between controlled cord traction and hands-off management groups with respect to the incidence of severe postpartum hemorrhage (relative risk 0.91, 95% confidence interval 0.77-1.08), need for blood transfusion (relative risk 0.96, 95% confidence interval 0.69-1.33) or therapeutic uterotonics (relative risk 0.94, 95% confidence interval 0.88-1.01). However, controlled cord traction reduced the incidence of postpartum hemorrhage in general (relative risk 0.93, 95% confidence interval 0.87-0.99; number-needed-to-treat 111, 95% confidence interval 61-666), as well manual removal of the placenta (relative risk 0.70, 95% confidence interval 0.58-0.84) and duration of the third stage of labor (mean difference -3.20, 95% confidence interval -3.21 to -3.19). Controlled cord traction appears to reduce the risk of any postpartum hemorrhage in a general sense, as well as manual removal of the placenta and the duration of the third stage of labor. However, the reduction in the occurrence of severe postpartum hemorrhage, need for additional uterotonics and blood transfusion is not statistically significant. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

An in vitro correlation of mechanical forces and metastatic capacity

NASA Astrophysics Data System (ADS)

Indra, Indrajyoti; Undyala, Vishnu; Kandow, Casey; Thirumurthi, Umadevi; Dembo, Micah; Beningo, Karen A.

2011-02-01

Mechanical forces have a major influence on cell migration and are predicted to significantly impact cancer metastasis, yet this idea is currently poorly defined. In this study we have asked if changes in traction stress and migratory properties correlate with the metastatic progression of tumor cells. For this purpose, four murine breast cancer cell lines derived from the same primary tumor, but possessing increasing metastatic capacity, were tested for adhesion strength, traction stress, focal adhesion organization and for differential migration rates in two-dimensional and three-dimensional environments. Using traction force microscopy (TFM), we were surprised to find an inverse relationship between traction stress and metastatic capacity, such that force production decreased as the metastatic capacity increased. Consistent with this observation, adhesion strength exhibited an identical profile to the traction data. A count of adhesions indicated a general reduction in the number as metastatic capacity increased but no difference in the maturation as determined by the ratio of nascent to mature adhesions. These changes correlated well with a reduction in active beta-1 integrin with increasing metastatic ability. Finally, in two dimensions, wound healing, migration and persistence were relatively low in the entire panel, maintaining a downward trend with increasing metastatic capacity. Why metastatic cells would migrate so poorly prompted us to ask if the loss of adhesive parameters in the most metastatic cells indicated a switch to a less adhesive mode of migration that would only be detected in a three-dimensional environment. Indeed, in three-dimensional migration assays, the most metastatic cells now showed the greatest linear speed. We conclude that traction stress, adhesion strength and rate of migration do indeed change as tumor cells progress in metastatic capacity and do so in a dimension-sensitive manner.

Posterior-only surgery with preoperative skeletal traction for management of severe scoliosis.

PubMed

Mehrpour, Saeedreza; Sorbi, Reza; Rezaei, Reza; Mazda, Keyvan

2017-04-01

The surgical treatment of severe adolescent spinal deformities is challenging and carries substantial risks of mortality and morbidity. To mitigate this risk, surgeons have employed various methods as this study designed to evaluate the safety and effectiveness of preoperative halo-femoral or halo gravity traction (HGT) followed by posterior-only surgery in the management of severe scoliosis. A total number of 23 patients with severe scoliosis treated by preoperative skeletal traction (halo gravity or halo femoral) followed by posterior fusion and instrumentation in one stage. All patients were followed for a minimum of 2 years after surgery. The average age of the patients was 12.7 years at the time of surgery. Mean of the Cobb angle improved from 99.9° ± 8.2° preoperatively to 75.3° ± 8° post-traction and 49.5° ± 7.7° postoperatively. Kyphosis angle corrected from 56.4° ± 9.5° to 38.6° ± 5.8°. The preop-FVC% was 41 ± 6.1% and after 1 year follow-up FVC% was 45.7 ± 7.7%. No patients required an anterior release due to amount of their deformity. Despite the benefits of modern instrumentation procedures, the treatment of severe scoliosis can be very competing. We think that by applying preoperative halo femoral traction and halo-gravity traction, managing severe scoliosis will be in safe and easy manner and can lead to better deformity correction and less neurological complications and facilitate to avoid anterior operation for severe scoliosis and its related complications.

A linearly controlled direct-current power source for high-current inductive loads in a magnetic suspension wind tunnel

NASA Technical Reports Server (NTRS)

Tripp, John S.; Daniels, Taumi S.

1990-01-01

The NASA Langley 6 inch magnetic suspension and balance system (MSBS) requires an independently controlled bidirectional DC power source for each of six positioning electromagnets. These electromagnets provide five-degree-of-freedom control over a suspended aerodynamic test model. Existing power equipment, which employs resistance coupled thyratron controlled rectifiers as well as AC to DC motor generator converters, is obsolete, inefficient, and unreliable. A replacement six phase bidirectional controlled bridge rectifier is proposed, which employs power MOSFET switches sequenced by hybrid analog/digital circuits. Full load efficiency is 80 percent compared to 25 percent for the resistance coupled thyratron system. Current feedback provides high control linearity, adjustable current limiting, and current overload protection. A quenching circuit suppresses inductive voltage impulses. It is shown that 20 kHz interference from positioning magnet power into MSBS electromagnetic model position sensors results predominantly from capacitively coupled electric fields. Hence, proper shielding and grounding techniques are necessary. Inductively coupled magnetic interference is negligible.

Apparatus and method for monitoring the presence of a conductive media

DOEpatents

DuVall, Bruce W.; Valentine, James W.; Morey, Kenneth O.

1979-01-01

An inductive level sensor has inductively coupled primary and secondary windings. Circuitry drives the primary with an AC signal of constant current magnitude and selected frequency f to induce in the secondary, a voltage signal V of magnitude .vertline.V.vertline., frequency f and phase difference .phi. from the driving signal. Circuitry operates to generate a voltage output signal proportional to .vertline.V.vertline. cos (.phi.-.theta.), where .theta. is a selectively set phase shift factor. By properly and selectively adjusting the frequency f and phase shift factor .theta., an output signal .vertline.V.vertline. cos (.phi.-.theta.) can be provided which self-compensates for changes in mutual inductance caused by operating temperature variations so that an output signal is produced which is substantially linearly proportional to changes in the level of a pool of liquid metal being monitored. Disclosed also is calibration circuitry and circuitry for converting the voltage signal .vertline.V.vertline. cos (.phi.-.theta.) into a current signal.

Designs and Plans for MAIZE: a 1 MA LTD-Driven Z-Pinch

NASA Astrophysics Data System (ADS)

Gilgenbach, R. M.; Gomez, M. R.; Zier, J.; Tang, W.; French, D. M.; Hoff, B. W.; Jordan, N.; Cruz, E.; Lau, Y. Y.; Fowler-Guzzardo, T.; Meisel, J.; Mazarakis, M. G.; Cuneo, M. E.; Johnston, M. D.; Mehlhorn, T. A.; Kim, A. A.; Sinebryukhov, V. A.

2007-11-01

We present designs and experimental plans of the first 1 MA z-pinch in the USA to be driven by a Linear Transformer Driver (LTD). The Michigan Accelerator for Inductive Z-pinch Experiments, (MAIZE), is based on the LTD developed at the Institute for High Current Electronics, utilizing 80 capacitors and 40 spark gap switches to deliver a 1 MA, 100 kV pulse with <100 ns risetime. Designs will be presented of a low-inductance MITL terminated in a wire-array z-pinch. Initial, planned experiments will evaluate the LTD driving time-changing inductance of imploding 4-16 wire-array z-pinches. Wire ablation dynamics, axial-correlations and instability development will be explored. *This work was supported by U. S. DoE through Sandia National Laboratories award number 240985 to the University of Michigan. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

A New Sensor Based Upon a Rotating-Coil Electromagnetic Induction Concept

DTIC Science & Technology

2006-12-01

of determining the transmitter coil position. The position must be known to produce a reference signal for the synchronous detector described in...schematically shown in Figure 14.3 Figure 14. Block diagram of the lock-in amplifier. This AC to DC conversion is performed by a phase- sensitive ... detector (PSD). It rectifies only the signal of interest while suppressing the noise or interfering signal components that may accompany the signal. To

Curing of a Bisphenol-E Based Cyanate Ester using Magnetic Nanoparticles as an Internal Heat Source through Induction Heating

DTIC Science & Technology

2013-11-01

magnetic field as a heat source for the polymerization avoids some of these difficulties. EXPERIMENTAL SECTION Iron (III) chloride hexahydrate (ACS...reagent, 97%), iron (II) chloride tetrahydrate (ReagentPlus®, 98%), tetramethylammonium hydroxide solution (25 wt. % in water), and oleic acid (technical...Edwards Air Force Base and used without further purification. Preparation of Iron Oxide Magnetic Nanoparticles.51 Iron (III) chloride hexahydrate (11.75

Preclinical and early clinical development of GNbAC1, a humanized IgG4 monoclonal antibody targeting endogenous retroviral MSRV-Env protein

PubMed Central

Curtin, François; Perron, Hervé; Kromminga, Arno; Porchet, Hervé; Lang, Alois B

2015-01-01

Monoclonal antibodies (mAbs) play an increasing important role in the therapeutic armamentarium against multiple sclerosis (MS), an inflammatory and degenerative disorder of the central nervous system. Most of the mAbs currently developed for MS are immunomodulators blocking the inflammatory immune process. In contrast with mAbs targeting immune function, GNbAC1, a humanized IgG4 mAb, targets the multiple sclerosis associated retrovirus envelope (MSRV-Env) protein, an upstream factor in the pathophysiology of MS. MSRV-Env protein is of endogenous retroviral origin, expressed in MS brain lesions, and it is pro-inflammatory and toxic to the remyelination process, by preventing the differentiation of oligodendrocyte precursor cells. We present the preclinical and early clinical development results of GNbAC1. The specificity of GNbAC1 for its endogenous retroviral target is described. Efficacy of different mAb versions of GNbAC1 were assessed in MSRV-Env induced experimental allergic encephalitis (EAE), an animal model of MS. Because the target MSRV-Env is not expressed in animals, no relevant animal model exists for a proper in vivo toxicological program. An off-target 2-week toxicity study in mice was thus performed, and it showed an absence of safety risk. Additional in vitro analyses showed an absence of complement or antibody-dependent cytotoxicity as well as a low level of cross-reactivity to human tissues. The first-in-man clinical study in 33 healthy subjects and a long-term clinical study in 10 MS patients showed that GNbAC1 is well tolerated in humans without induction of immunogenicity and that it induces a pharmacodynamic response on MSRV biomarkers. These initial results suggest that the mAb GNbAC1 could be a safe long-term treatment for patients with MS with a unique therapeutic mechanism of action. PMID:25427053

Mg shallow doping effects on the ac magnetic self-heating characteristics of γ-Fe2O3 superparamagnetic nanoparticles for highly efficient hyperthermia

NASA Astrophysics Data System (ADS)

Jang, Jung-tak; Bae, Seongtae

2017-10-01

The effects of Mg doping on the magnetic and AC self-heating temperature rising characteristics of γ-Fe2O3 superparamagnetic nanoparticles (SPNPs) were investigated for hyperthermia applications in biomedicine. The doping concentration of nonmagnetic Mg2+ cation was systematically controlled from 0 to 0.15 at. % in Mgx-γFe2O3 SPNPs during chemically and thermally modified one-pot thermal decomposition synthesis under bubbling O2/Ar gas mixture. It was empirically observed that the saturation magnetization (Ms) and the out-of-phase magnetic susceptibility ( χm″)of Mgx-γFe2O3 SPNPs were increased by increasing the Mg2+ cation doping concentration from 0.05 to 0.13 at. %. Correspondingly, the AC magnetically induced self-heating temperature (Tac,max) in solid state and the intrinsic loss power in water were increased up to 184 °C and 14.2 nH m2 kg-1 (Mgx-γFe2O3, x = 0.13), respectively, at the biologically and physiologically safe range of AC magnetic field (Happl × fappl = 1.2 × 109 A m-1 s-1). All the chemically and physically analyzed results confirmed that the dramatically improved AC magnetic induction heating characteristics and the magnetic properties of Mgx-γFe2O3 SPNPs (x = 0.13) are primarily due to the significantly enhanced magnetic susceptibility (particularly, χm″) and the improved AC/DC magnetic softness (lower AC/DC magnetic anisotropy) resulting from the systematically controlled nonmagnetic Mg2+ cation concentrations and distributions (occupation ratio) in the Fe vacancy sites of γ-Fe2O3 (approximately 12% vacancy), instead of typically well-known Fe3O4 (no vacancy) SPNPs. The cell viability and biocompatibility with U87 MG cell lines demonstrated that Mgx-γFe2O3 SPNPs (x = 0.13) has promising bio-feasibility for hyperthermia agent applications.

MO-FG-CAMPUS-TeP3-05: Limitations of the Dose Weighted LET Concept for Intensity Modulated Proton Therapy in the Distal Falloff Region and Beyond

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

Moskvin, V; Pirlepesov, F; Farr, J

2016-06-15

Purpose: Dose-weighted linear energy transfer (dLET) has been shown to be useful for the analysis of late effects in proton therapy. This study presents the results of the testing of the dLET concept for intensity modulated proton therapy (IMPT) with a discrete spot scanning beam system without use of an aperture or compensator (AC). Methods: IMPT (no AC) and broad beams (BB) with (AC) were simulated in the TOPAS and FLUKA code systems. Information from the independently tested Monte Carlo Damage Simulation (MCDS) was integrated into the FLUKA code systems to account for spatial variations in the RBE for protonsmore » and other light ions using an endpoint of DNA double strand break (DSB) induction. Results: The proton spectra for IMPT beams at the depths beyond the distal edge contain a tail of high energy protons up to 100 MeV. The integral from the tail is compatible with the number of 5–8 MeV protons at the tip of the Bragg peak (BP). The dose averaged energy (dEav) decreases to 7 MeV at the tip of (BP) and then increases to about 15 MeV beyond the distal edge. Neutrons produced in the nozzle are two orders of magnitude higher for BB with AC than for IMPT in low energy part of the spectra. The dLET values beyond of the distal edge of the BP are 5 times larger for the IMPT than for BB with the AC. Contrarily, negligible differences are seen in the RBE estimates for IMPT and BB with AC beyond the distal edge of the BP. Conclusion: The analysis of late effects in IMPT with a spot scanning and double scattering or scanning techniques with AC may requires both dLET and RBE as quantitative parameters to characterize effects beyond the distal edge of the BP.« less

Toroidal-Core Microinductors Biased by Permanent Magnets

NASA Technical Reports Server (NTRS)

Lieneweg, Udo; Blaes, Brent

2003-01-01

The designs of microscopic toroidal-core inductors in integrated circuits of DC-to-DC voltage converters would be modified, according to a proposal, by filling the gaps in the cores with permanent magnets that would apply bias fluxes (see figure). The magnitudes and polarities of the bias fluxes would be tailored to counteract the DC fluxes generated by the DC components of the currents in the inductor windings, such that it would be possible to either reduce the sizes of the cores or increase the AC components of the currents in the cores without incurring adverse effects. Reducing the sizes of the cores could save significant amounts of space on integrated circuits because relative to other integrated-circuit components, microinductors occupy large areas - of the order of a square millimeter each. An important consideration in the design of such an inductor is preventing magnetic saturation of the core at current levels up to the maximum anticipated operating current. The requirement to prevent saturation, as well as other requirements and constraints upon the design of the core are expressed by several equations based on the traditional magnetic-circuit approximation. The equations involve the core and gap dimensions and the magnetic-property parameters of the core and magnet materials. The equations show that, other things remaining equal, as the maximum current is increased, one must increase the size of the core to prevent the flux density from rising to the saturation level. By using a permanent bias flux to oppose the flux generated by the DC component of the current, one would reduce the net DC component of flux in the core, making it possible to reduce the core size needed to prevent the total flux density (sum of DC and AC components) from rising to the saturation level. Alternatively, one could take advantage of the reduction of the net DC component of flux by increasing the allowable AC component of flux and the corresponding AC component of current. In either case, permanent-magnet material and the slant (if any) and thickness of the gap must be chosen according to the equations to obtain the required bias flux. In modifying the design of the inductor, one must ensure that the inductance is not altered. The simplest way to preserve the original value of inductance would be to leave the gap dimensions unchanged and fill the gap with a permanent- magnet material that, fortuitously, would produce just the required bias flux. A more generally applicable alternative would be to partly fill either the original gap or a slightly enlarged gap with a suitable permanent-magnet material (thereby leaving a small residual gap) so that the reluctance of the resulting magnetic circuit would yield the desired inductance.

Magnetic characteristics and AC losses of DC type-II superconductors under oscillating magnetic fields

NASA Astrophysics Data System (ADS)

Robert, B. C.; Ruiz, H. S.

2018-07-01

Remarkable features on the magnetic moment of type-II superconducting (SC) wires of cylindrical shape, subjected to direct current conditions (DC) and transverse oscillating (AC) magnetic fields, are reported. We show how for relatively low amplitudes of the applied magnetic field, B a , the superconducting wire rapidly develops a saturation state, | {M}p| , characterizing the limits of magnetization loops that exhibit a Boolean-like behaviour. Regardless of the premagnetization state of the SC wire, we show how after two cycles of magnetic relaxation, boolean-like ±M p states can be measured during the entire period of time from which the external magnetic field B 0 ranges from 0 to ±B a , with the signs rule defined by the sign of the slope ΔB 0y (t). In addition, for the practical implementation of SC DC wires sharing the right of way with AC lines, we report that for relatively low values of magnetic field, {B}a≤slant {B}P/2, being B P the analytical value for the full penetration field in absence of transport current, I tr, the use of semi-analytical approaches for the calculation of AC losses leads to a significant underestimation of the actual contribution of the induction losses. This phenomena is particularly relevant at dimensionless fields {b}a< 1-{i}a2/3, being b a = B a /B P and, i a = I a /I c the amplitude of an AC or DC transport current, due to the local motion of flux front profiles being dominated by the occurrence of transport current. On the other hand, we have found that regardless of the nature of the transport current, either be DC or AC, when a transverse oscillating magnetic field greater than the classical limit b a = (1 - i a ) is applied to the SC wire, the difference between the obtained AC losses in both situations results to be negligible indistinctly of the approach used, semi-analytical or numerical. Thus, the actual limits from which the estimation of the AC losses can be used as an asset for the deployment of DC SC wires sharing the right of way with AC lines, against the sole use of SC wires for the transmission of AC transport current, are established.

Investigation of brachial plexus traction lesions by peripheral and spinal somatosensory evoked potentials.

PubMed Central

Jones, S J

1979-01-01

Peripheral, spinal and cortical somatosensory evoked potentials were recorded in 26 patients with unilateral traction injuries of the brachial plexus ganglia. Of 10 cases explored surgically the recordings correctly anticipated the major site of the lesion in eight. PMID:422958

Etude de l'influence de la temperature et de l'humidite sur les proprietes mecaniques en traction des fibres de chanvre et de coco

NASA Astrophysics Data System (ADS)

Ho Thi, Thu Nga

L'objectif de cette etude fut d'etablir l'effet de l'humidite et de la temperature sur la resistance en traction et le module elastique des fibres de chanvre et de coco. Deux etudes ont ete realisees afin d'atteindre cet objectif. La premiere vise l'absorption de l'humidite dans ces fibres en exposition dans l'air (de 0%RH a 80%RH) ainsi que l'absorption de l'eau dans ces fibres immergees dans l'eau aux differentes temperatures. La deuxieme consiste a mesurer la resistance en traction et le module elastique de ces fibres sous differentes conditions d'humidite et de temperature. En basant sur les resultats experimentaux obtenus, les methodes semi empiriques et de reseaux de neurones ont ete utilisees pour but de predire les proprietes en traction (resistance et module d'elasticite) des fibres de chanvre et de coco sous l'influence de l'humidite et de la temperature.

Traction test of temporary dental cements

PubMed Central

Millan-Martínez, Diego; Fons-Font, Antonio; Agustín-Panadero, Rubén; Fernández-Estevan, Lucía

2017-01-01

Background Classic self-curing temporary cements obstruct the translucence of provisional restorations. New dual-cure esthetic temporary cements need investigation and comparison with classic cements to ensure that they are equally retentive and provide adequate translucence. The objective is to analyze by means of traction testing in a in vitro study the retention of five temporary cements. Material and Methods Ten molars were prepared and ten provisional resin restorations were fabricated using CAD-CAM technology (n=10). Five temporary cements were selected: self-curing temporary cements, Dycal (D), Temp Bond (TB), Temp Bond Non Eugenol (TBNE); dual-curing esthetic cements Temp Bond Clear (TBC) and Telio CS link (TE). Each sample underwent traction testing, both with thermocycling (190 cycles at 5-55º) and without thermocycling. Results TE and TBC obtained the highest traction resistance values. Thermocycling reduced the resistance of all cements except TBC. Conclusions The dual-cure esthetic cements tested provided optimum outcomes for bonding provisional restorations. Key words:Temporary dental cements, cements resistance. PMID:28469824

Degradation-mediated cellular traction directs stem cell fate in covalently crosslinked three-dimensional hydrogels

NASA Astrophysics Data System (ADS)

Khetan, Sudhir; Guvendiren, Murat; Legant, Wesley R.; Cohen, Daniel M.; Chen, Christopher S.; Burdick, Jason A.

2013-05-01

Although cell-matrix adhesive interactions are known to regulate stem cell differentiation, the underlying mechanisms, in particular for direct three-dimensional encapsulation within hydrogels, are poorly understood. Here, we demonstrate that in covalently crosslinked hyaluronic acid (HA) hydrogels, the differentiation of human mesenchymal stem cells (hMSCs) is directed by the generation of degradation-mediated cellular traction, independently of cell morphology or matrix mechanics. hMSCs within HA hydrogels of equivalent elastic moduli that permit (restrict) cell-mediated degradation exhibited high (low) degrees of cell spreading and high (low) tractions, and favoured osteogenesis (adipogenesis). Moreover, switching the permissive hydrogel to a restrictive state through delayed secondary crosslinking reduced further hydrogel degradation, suppressed traction, and caused a switch from osteogenesis to adipogenesis in the absence of changes to the extended cellular morphology. Furthermore, inhibiting tension-mediated signalling in the permissive environment mirrored the effects of delayed secondary crosslinking, whereas upregulating tension induced osteogenesis even in the restrictive environment.

High mobility vehicle

NASA Technical Reports Server (NTRS)

Wilcox, Brian H. (Inventor); Nasif, Annette K. (Inventor)

2001-01-01

A vehicle, for driving over a ground surface, has a body with a left side, a right side, a front and a back. The vehicle includes left and right drive mechanisms. Each mechanism includes first and second traction elements for engaging the ground surface and transmitting a driving force between the vehicle and ground surface. Each mechanism includes first and second arms coupled to the first and second traction elements for relative rotation about first and second axis respectively. Each mechanism includes a rotor having a third axis, the rotor coupled to the body for rotation about the third axis and coupled to the first and second arms for relative rotation about the third axis. The mechanism includes first and second drive motors for driving the first and second traction elements and first and second transmissions, driven by the first and second motors and engaging the rotor. Driving the first and second traction elements simultaneously rotates the rotor relative to the first and second arms, respectively.

An overview of the development of lead/acid traction batteries for electric vehicles in India

NASA Astrophysics Data System (ADS)

Sivaramaiah, G.; Subramanian, V. R.

Electric vehicles (EVs) made an entry into the Indian scene quite recently in the area of passenger transportation, milk floats and other similar applications. The industrial EV market, with various models of fork-lift trucks and platform trucks already in wide use all over India, is a better understood application of EV batteries. The lead/acid traction batteries available in India are not of high-energy density. The best available indigenous lead/acid traction battery has an energy density ( C/5 rate) of 30 W h kg -1 as against 39 W h kg -1 available abroad. This paper reviews the developmental efforts relating to lead/acid traction batteries for electric vehicle applications in India, such as prototype road vehicles, commercial vehicles, rail cars, and locomotives. Due to the need for environmental protection and recognition of exhaustible, finite supplies of petroleum fuel, the Indian government is presently taking active interest in EV projects.

Demagnetization monitoring and life extending control for permanent magnet-driven traction systems

NASA Astrophysics Data System (ADS)

Niu, Gang; Liu, Senyi

2018-03-01

This paper presents a novel scheme of demagnetization monitoring and life extending control for traction systems driven by permanent magnet synchronous motors (PMSMs). Firstly, the offline training is carried to evaluate fatigue damage of insulated gate bipolar transistors (IGBTs) under different flux loss based on first-principle modeling. Then an optimal control law can be extracted by turning down the power distribution factor of the demagnetizing PMSM until all damages of IGBTs turn to balance. Next, the similarity-based empirical modeling is employed to online estimate remaining flux of PMSMs, which is used to update the power distribution factor by referring the optimal control law for the health-oriented autonomous control. The proposed strategy can be demonstrated by a case study of traction drive system coupled with dual-PMSMs. Compared with traditional control strategy, the results show that the novel scheme can not only guarantee traction performance but also extend remaining useful life (RUL) of the system after suffering demagnetization fault.

Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

NASA Technical Reports Server (NTRS)

Byrdsong, T. A.

1973-01-01

An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

Force transmission in migrating cells

PubMed Central

Sauser, Roger; Ambrosi, Davide; Meister, Jean-Jacques; Verkhovsky, Alexander B.

2010-01-01

During cell migration, forces generated by the actin cytoskeleton are transmitted through adhesion complexes to the substrate. To investigate the mechanism of force generation and transmission, we analyzed the relationship between actin network velocity and traction forces at the substrate in a model system of persistently migrating fish epidermal keratocytes. Front and lateral sides of the cell exhibited much stronger coupling between actin motion and traction forces than the trailing cell body. Further analysis of the traction–velocity relationship suggested that the force transmission mechanisms were different in different cell regions: at the front, traction was generated by a gripping of the actin network to the substrate, whereas at the sides and back, it was produced by the network’s slipping over the substrate. Treatment with inhibitors of the actin–myosin system demonstrated that the cell body translocation could be powered by either of the two different processes, actomyosin contraction or actin assembly, with the former associated with significantly larger traction forces than the latter. PMID:20100912

Power-Factor and Torque Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

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

Lee, Seong T; Burress, Timothy A; Tolbert, Leon M

2009-01-01

This paper introduces a new method for calculating the power factor and output torque by considering the cross saturation between direct-axis (d-axis) and quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux atmore » high speed, which was developed for the traction motor of a hybrid electric vehicle. The conventional two-axis IPMSM model was modified to include the cross-saturation effect by adding the cross-coupled inductance terms Ldq and Lqd. By the advantage of the excited structure of the experimental IPMSM, the analyzing works were performed under two conditions, the highest and lowest excited conditions. Therefore, it is possible to investigate the cross-saturation effect when a machine has higher magnetic flux from its rotor. The following is a summary of conclusions that may be drawn from this work: (1) Considering cross saturation of an IPMSM offers more accurate expected values of motor parameters in output torque calculation, especially when negative d-axis current is high; (2) A less saturated synchronous machine could be more affected by the cross-coupled saturation effect; (3) Both cross-coupled inductances, L{sub qd} and L{sub dq}, are mainly governed by d-axis current rather than q-axis current; (4) The modified torque equation, can be used for the dynamic model of an IPMSM for developing a better control model or control strategy; and (5) It is possible that the brushless field excitation structure has a common magnetic flux path on both d- and q-axis, and as a result, the reluctance torque of the machine could be reduced.« less

A Sticky Situation.

PubMed

Weng, Christina Y; Khimani, Karima S; Foroozan, Rod; Gospe, Sidney M; Bhatti, M Tariq

2018-04-26

An 81-year-old man with bilateral progressively blurry vision and optic disc swelling was referred for evaluation. Examination and ancillary testing confirmed a diagnosis of bilateral vitreopapillary traction (VPT) accompanied by unilateral tractional retinoschisis in the right eye. Pars plana vitrectomy was performed to release the traction in both eyes. Visual acuity improved in the right eye and stabilized in the left eye. Retinoschisis in the right eye resolved. The visual field improved in both eyes, although the left eye demonstrated a persistent hemifield defect likely attributable to a prior optic neuropathy. Distinguishing VPT optic neuropathy (VPTON) from nonarteritic anterior ischemic optic neuropathy (NAION) is discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

Parametric tests of a traction drive retrofitted to an automotive gas turbine

NASA Technical Reports Server (NTRS)

Rohn, D. A.; Lowenthal, S. H.; Anderson, N. E.

1980-01-01

The results of a test program to retrofit a high performance fixed ratio Nasvytis Multiroller Traction Drive in place of a helical gear set to a gas turbine engine are presented. Parametric tests up to a maximum engine power turbine speed of 45,500 rpm and to a power level of 11 kW were conducted. Comparisons were made to similar drives that were parametrically tested on a back-to-back test stand. The drive showed good compatibility with the gas turbine engine. Specific fuel consumption of the engine with the traction drive speed reducer installed was comparable to the original helical gearset equipped engine.

Design, Simulation and Fabrication of A MEMS-based Double-layer Spiral Planar Inductor with Patterned Permalloy as Magnetic Layers

NASA Astrophysics Data System (ADS)

Zhu, Xiaomin; Cheng, Ping; Chen, Mingming; Ding, Guifu

2018-03-01

There have been significant efforts to boost the inductance value by adopting the sandwich structures using permalloy magnetic shielding layers. However, this structure will introduce high ac conductor losses and high eddy currents. In order to solve these problems, patterned permalloy can solve this problem effectively. According to the simulation results based on the application of finite element method in the frequency domain, the optimum permalloy pattern is which the blank of the permalloy are perpendicular to the coil inside. The double-layer planar inductor has a size of l5×1.5×0.1mm consisted of 13-turn spiral Cu coil for each layer and a 20μm-thick patterned permalloy magnetic shielding layer. The inductor shows a higher inductance than the traditional planar inductor. The patterned permalloy made the inductor more stable in high frequency than the none-patterned. And the inductor has an inductance of 1.3μH and quality factor of 2.8 at 1.5MHz, with an inductance per unit of 578nH/mm2, which is much higher than that in the reported literatures.

Prediction of traction forces of motile cells.

PubMed

Roux, Clément; Duperray, Alain; Laurent, Valérie M; Michel, Richard; Peschetola, Valentina; Verdier, Claude; Étienne, Jocelyn

2016-10-06

When crawling on a flat substrate, living cells exert forces on it via adhesive contacts, enabling them to build up tension within their cytoskeleton and to change shape. The measurement of these forces has been made possible by traction force microscopy (TFM), a technique which has allowed us to obtain time-resolved traction force maps during cell migration. This cell 'footprint' is, however, not sufficient to understand the details of the mechanics of migration, that is how cytoskeletal elements (respectively, adhesion complexes) are put under tension and reinforce or deform (respectively, mature and/or unbind) as a result. In a recent paper, we have validated a rheological model of actomyosin linking tension, deformation and myosin activity. Here, we complement this model with tentative models of the mechanics of adhesion and explore how closely these models can predict the traction forces that we recover from experimental measurements during cell migration. The resulting mathematical problem is a PDE set on the experimentally observed domain, which we solve using a finite-element approach. The four parameters of the model can then be adjusted by comparison with experimental results on a single frame of an experiment, and then used to test the predictive power of the model for following frames and other experiments. It is found that the basic pattern of traction forces is robustly predicted by the model and fixed parameters as a function of current geometry only.

The effects of infrared laser therapy and weightbath traction hydrotherapy as components of complex physical treatment in disorders of the lumbar spine: a controlled pilot study with follow-up

NASA Astrophysics Data System (ADS)

Oláh, Csaba; Oláh, Mihály; Demeter, Béla; Jancsó, Zoltán; Páll, Valéria; Bender, Tamás

2010-02-01

Introduction: The therapeutic modalities available for the conservative management of chronic lumbar pain included infrared laser therapy and underwater traction, which usefulness is not universally acknowledged. This study was intended to ascertain any beneficial impact of infrared laser therapy and weightbath treatment on the clinical parameters and quality of life of patients with lumbar discopathy. Material and methods: The study population comprised 54 randomised subjects. I. group of 18 patents received only infrared laser therapy to lumbar region and painful Valley points. II. group of 18 subjects each received underwater traction therapy of lumbar spine with add-on McKenzie exercise and iontophoresis. The remaining III. group treated with exercise and iontophoresis, served as control. VAS, Oswestry index, SF36 scores, range of motion, neurological findings and thermography were monitored to appraise therapeutic afficacy in lumbar discopathy. A CT or MRI scan was done at baseline and after 3 months follow-up. Result:Infrared laser therapy and underwater traction for discopathy achieved significant improvement of all study parameters, which was evident 3 months later. Among the controls, significant improvement of only a single parameter was seen in patients with lumbar discopathy. Conclusions: Infrared laser therapy and underwater traction treatment effectively mitigate pain, muscle spasms, enhance joint flexibility, and improve the quality of life of patients with lumbar discopathy.

Correlation between dielectric property by dielectrophoretic levitation and growth activity of cells exposed to electric field.

PubMed

Hakoda, Masaru; Hirota, Yusuke

2013-09-01

The purpose of this study is to develop a system analyzing cell activity by the dielectrophoresis method. Our previous studies revealed a correlation between the growth activity and dielectric property (Re[K(ω)]) of mouse hybridoma 3-2H3 cells using dielectrophoretic levitation. Furthermore, it was clarified that the differentiation activity of many stem cells could be evaluated by the Re[K(ω)] without differentiation induction. In this paper, 3-2H3 cells exposed to an alternating current (AC) electric field or a direct current (DC) electric field were cultivated, and the influence of damage by the electric field on the growth activity of the cells was examined. To evaluate the activity of the cells by measuring the Re[K(ω)], the correlation between the growth activity and the Re[K(ω)] of the cells exposed to the electric field was examined. The relations between the cell viability, growth activity, and Re[K(ω)] in the cells exposed to the AC electric field were obtained. The growth activity of the cells exposed to the AC electric field could be evaluated by the Re[K(ω)]. Furthermore, it was found that the adverse effects of the electric field on the cell viability and the growth activity were smaller in the AC electric field than the DC electric field.

Plant HDAC inhibitor chrysin arrest cell growth and induce p21WAF1 by altering chromatin of STAT response element in A375 cells

PubMed Central

2012-01-01

Background Chrysin and its analogues, belongs to flavonoid family and possess potential anti-tumour activity. The aim of this study is to determine the molecular mechanism by which chrysin controls cell growth and induce apoptosis in A375 cells. Methods Effect of chrysin and its analogues on cell viability and cell cycle analysis was determined by MTT assay and flowcytometry. A series of Western blots was performed to determine the effect of chrysin on important cell cycle regulatory proteins (Cdk2, cyclin D1, p53, p21, p27). The fluorimetry and calorimetry based assays was conducted for characterization of chrysin as HDAC inhibitor. The changes in histone tail modification such as acetylation and methylation was studied after chrysin treatment was estimated by immuno-fluorescence and western blot analysis. The expression of Bcl-xL, survivin and caspase-3 was estimated in chrysin treated cells. The effect of chrysin on p21 promoter activity was studied by luciferase and ChIP assays. Results Chrysin cause G1 cell cycle arrest and found to inhibit HDAC-2 and HDAC-8. Chrysin treated cells have shown increase in the levels of H3acK14, H4acK12, H4acK16 and decrease in H3me2K9 methylation. The p21 induction by chrysin treatment was found to be independent of p53 status. The chromatin remodelling at p21WAF1 promoter induces p21 activity, increased STAT-1 expression and epigenetic modifications that are responsible for ultimate cell cycle arrest and apoptosis. Conclusion Chrysin shows in vitro anti-cancer activity that is correlated with induction of histone hyperacetylation and possible recruitment of STAT-1, 3, 5 proteins at STAT (−692 to −684) region of p21 promoter. Our results also support an unexpected action of chrysin on the chromatin organization of p21WAF1 promoter through histone methylation and hyper-acetylation. It proposes previously unknown sequence specific chromatin modulations in the STAT responsive elements for regulating cell cycle progression negatively via the induction of the CDK inhibitor p21WAF1. PMID:22591439

The dynamical conductance of graphene tunnelling structures.

PubMed

Zhang, Huan; Chan, K S; Lin, Zijing

2011-12-16

The dynamical conductances of graphene tunnelling structures were numerically calculated using the scattering matrix method with the interaction effect included in a phenomenological approach. The overall single-barrier dynamical conductance is capacitative. Transmission resonances in the single-barrier structure lead to dips in the capacitative imaginary part of the response. This is different from the ac responses of typical semiconductor nanostructures, where transmission resonances usually lead to inductive peaks. The features of the dips depend on the Fermi energy. When the Fermi energy is below half of the barrier height, the dips are sharper. When the Fermi energy is higher than half of the barrier height, the dips are broader. Inductive behaviours can be observed in a double-barrier structure due to the resonances formed by reflection between the two barriers.

21 CFR 882.5960 - Skull tongs for traction.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Skull tongs for traction. 882.5960 Section 882.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... cervical spine injury (e.g., fracture or dislocation). The device is caliper shaped with tips that...

Hardware-in-the-Loop emulator for a hydrokinetic turbine

NASA Astrophysics Data System (ADS)

Rat, C. L.; Prostean, O.; Filip, I.

2018-01-01

Hydroelectric power has proven to be an efficient and reliable form of renewable energy, but its impact on the environment has long been a source of concern. Hydrokinetic turbines are an emerging class of renewable energy technology designed for deployment in small rivers and streams with minimal environmental impact on the local ecosystem. Hydrokinetic technology represents a truly clean source of energy, having the potential to become a highly efficient method of harvesting renewable energy. However, in order to achieve this goal, extensive research is necessary. This paper presents a Hardware-in-the-Loop emulator for a run-of-the-river type hydrokinetic turbine. The HIL system uses an ABB ACS800 drive to control an induction machine as a significant means of replicating the behavior of the real turbine. The induction machine is coupled to a permanent magnet synchronous generator and the corresponding load. The ACS800 drive is controlled through the software system, which comprises of the hydrokinetic turbine real-time simulation through mathematical modeling in the LabVIEW programming environment running on a NI CompactRIO (cRIO) platform. The advantages of this method are that it can provide a means for testing many control configurations without requiring the presence of the real turbine. This paper contains the basic principles of a hydrokinetic turbine, particularly the run-of-the-river configurations along with the experimental results obtained from the HIL system.

Design and simulation of control algorithms for stored energy and plasma current in non-inductive scenarios on NSTX-U

NASA Astrophysics Data System (ADS)

Boyer, Mark; Andre, Robert; Gates, David; Gerhardt, Stefan; Menard, Jonathan; Poli, Francesca

2015-11-01

One of the major goals of NSTX-U is to demonstrate non-inductive operation. To facilitate this and other program goals, the center stack has been upgraded and a second neutral beam line has been added with three sources aimed more tangentially to provide higher current drive efficiency and the ability to shape the current drive profile. While non-inductive start-up and ramp-up scenarios are being developed, initial non-inductive studies will likely rely on clamping the Ohmic coil current after the plasma current has been established inductively. In this work the ability to maintain control of stored energy and plasma current once the Ohmic coil has been clamped is explored. The six neutral beam sources and the mid-plane outer gap of the plasma are considered as actuators. System identification is done using TRANSP simulations in which the actuators are modulated around a reference shot. The resulting reduced model is used to design an optimal control law with anti-windup and a recently developed framework for closed loop simulations in TRANSP is used to test the control. Limitations due to actuator saturation are assessed and robustness to beam modulation, changes in the plasma density and confinement, and changes in density and temperature profile shapes are studied. Supported by US DOE contract DE-AC02-09CH11466.

Animal Traction. Appropriate Technologies for Development. Manual M-12.

ERIC Educational Resources Information Center

Watson, Peter R.

This manual is designed for use by Peace Corps volunteers and agricultural extension personnel working in animal traction development programs. While some of the information contained in the manual is specific to the extension of animal-powered agriculture in Africa, the principles covered are generally applicable wherever the method is being used…

Laboratory testing of the (Japan Storage Battery) traction batteries GS E75A and GS E150H

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

Not Available

This report describes the testing of the GS E75A and GS E150H flooded lead-acid 12-volt traction batteries and compares the selected batteries to U.S.-made electric vehicle batteries. The results and conclusions of the testing are presented.

Design study of toroidal traction CVT for electric vehicles

NASA Technical Reports Server (NTRS)

Raynard, A. E.; Kraus, J.; Bell, D. D.

1980-01-01

The development, evaluation, and optimization of a preliminary design concept for a continuously variable transmission (CVT) to couple the high-speed output shaft of an energy storage flywheel to the drive train of an electric vehicle is discussed. An existing computer simulation program was modified and used to compare the performance of five CVT design configurations. Based on this analysis, a dual-cavity full-toroidal drive with regenerative gearing is selected for the CVT design configuration. Three areas are identified that will require some technological development: the ratio control system, the traction fluid properities, and evaluation of the traction contact performance. Finally, the suitability of the selected CVT design concept for alternate electric and hybrid vehicle applications and alternate vehicle sizes and maximum output torques is determined. In all cases the toroidal traction drive design concept is applicable to the vehicle system. The regenerative gearing could be eliminated in the electric powered vehicle because of the reduced ratio range requirements. In other cases the CVT with regenerative gearing would meet the design requirements after appropriate adjustments in size and reduction gearing ratio.

A Simple Force-Motion Relation for Migrating Cells Revealed by Multipole Analysis of Traction Stress

PubMed Central

Tanimoto, Hirokazu; Sano, Masaki

2014-01-01

For biophysical understanding of cell motility, the relationship between mechanical force and cell migration must be uncovered, but it remains elusive. Since cells migrate at small scale in dissipative circumstances, the inertia force is negligible and all forces should cancel out. This implies that one must quantify the spatial pattern of the force instead of just the summation to elucidate the force-motion relation. Here, we introduced multipole analysis to quantify the traction stress dynamics of migrating cells. We measured the traction stress of Dictyostelium discoideum cells and investigated the lowest two moments, the force dipole and quadrupole moments, which reflect rotational and front-rear asymmetries of the stress field. We derived a simple force-motion relation in which cells migrate along the force dipole axis with a direction determined by the force quadrupole. Furthermore, as a complementary approach, we also investigated fine structures in the stress field that show front-rear asymmetric kinetics consistent with the multipole analysis. The tight force-motion relation enables us to predict cell migration only from the traction stress patterns. PMID:24411233

The wall traction induced by flowing red blood cells in model microvessels and its potential mechanotransduction

NASA Astrophysics Data System (ADS)

Freund, Jonathan; Vermot, Julien

2013-11-01

There is evidence in early embryonic development, even well before advective oxygen transport is important, that the presence of red bloods cells per se trigger essential steps of normal vascular development. For example, showed that sequestration of blood cells early in the development of a mouse, such that the hematocrit is reduced, suppresses normal vascular network development. Vascular development also provides a model for remodeling and angiogenesis. We consider the transient stresses associated with blood cells flowing in model microvessels of comparable diameter to those at early stages of development (6 μm to 12 μm). A detailed simulation tool is used to show that passing blood cells present a significant fluctuating traction signature on the vessel wall, well above the mean stresses. This is particularly pronounced for slow flows (<= 50 μm/s) or small diameters (<= 7 μm), for which root-mean-square wall traction fluctuations can exceed their mean. These events potentially present mechanotranduction triggers that direct development or remodeling. Attenuation of such fluctuating tractions by a viscoelastic endothelial glycocalyx layer is also considered. NSF supported.

Lateral traction of laminar flow between sliding pair with heterogeneous slip/no-slip surface

NASA Astrophysics Data System (ADS)

Wu, Zhenpeng; Zeng, Liangcai; Chen, Xiaolan; Chen, Keying; Ding, Xianzhong

2017-11-01

The problem of shaft axial motion which significantly affects the lubrication performance has been a common phenomenon in journal bearing systems. The existing work involved in the solution of shaft axial motion is also very rare. In this study, we choose to examine the flow between sliding pair in which regard we present a unique heterogeneous surface consisting of a slip zone and a no-slip zone. The results reveal the following points: 1) By appropriately arranging the slip zone to change the angle between the borderline and the moving direction of the upper plate, it is possible to control the direction of the lateral traction in which the liquid film acts on the upper plate. 2) Exponent of the power function of the borderline and aspect ratio of the computational domain are large or small are not conducive to increasing the effect of lateral traction. For the object of this study, the final results of the optimization are shown that the lateral traction can account for 20% of the resistance.

Effects of Electric Vehicle Fast Charging on Battery Life and Vehicle Performance

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

Matthew Shirk; Jeffrey Wishart

2015-04-01

As part of the U.S. Department of Energy’s Advanced Vehicle Testing Activity, four new 2012 Nissan Leaf battery electric vehicles were instrumented with data loggers and operated over a fixed on-road test cycle. Each vehicle was operated over the test route, and charged twice daily. Two vehicles were charged exclusively by AC level 2 EVSE, while two were exclusively DC fast charged with a 50 kW charger. The vehicles were performance tested on a closed test track when new, and after accumulation of 50,000 miles. The traction battery packs were removed and laboratory tested when the vehicles were new, andmore » at 10,000-mile intervals. Battery tests include constant-current discharge capacity, electric vehicle pulse power characterization test, and low peak power tests. The on-road testing was carried out through 70,000 miles, at which point the final battery tests were performed. The data collected over 70,000 miles of driving, charging, and rest are analyzed, including the resulting thermal conditions and power and cycle demands placed upon the battery. Battery performance metrics including capacity, internal resistance, and power capability obtained from laboratory testing throughout the test program are analyzed. Results are compared within and between the two groups of vehicles. Specifically, the impacts on battery performance, as measured by laboratory testing, are explored as they relate to battery usage and variations in conditions encountered, with a primary focus on effects due to the differences between AC level 2 and DC fast charging. The contrast between battery performance degradation and the effect on vehicle performance is also explored.« less

Roles for herpes simplex virus type 1 U{sub L}34 and U{sub S}3 proteins in disrupting the nuclear lamina during herpes simplex virus type 1 egress

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

Bjerke, Susan L.; Roller, Richard J.

2006-04-10

Cells infected with wild type HSV-1 showed significant lamin A/C and lamin B rearrangement, while U{sub L}34-null virus-infected cells exhibited few changes in lamin localization, indicating that U{sub L}34 is necessary for lamin disruption. During HSV infection, U{sub S}3 limited the development of disruptions in the lamina, since cells infected with a U{sub S}3-null virus developed large perforations in the lamin layer. U{sub S}3 regulation of lamin disruption does not correlate with the induction of apoptosis. Expression of either U{sub L}34 or U{sub S}3 proteins alone disrupted lamin A/C and lamin B localization. Expression of U{sub L}34 and U{sub S}3more » together had little effect on lamin A/C localization, suggesting a regulatory interaction between the two proteins. The data presented in this paper argue for crucial roles for both U{sub L}34 and U{sub S}3 in regulating the state of the nuclear lamina during viral infection.« less

Bulky melamine-based Zn-porphyrin tweezer as a CD probe of molecular chirality.

PubMed

Petrovic, Ana G; Vantomme, Ghislaine; Negrón-Abril, Yashira L; Lubian, Elisa; Saielli, Giacomo; Menegazzo, Ileana; Cordero, Roselynn; Proni, Gloria; Nakanishi, Koji; Carofiglio, Tommaso; Berova, Nina

2011-10-01

The transfer of chirality from a guest molecule to an achiral host is the subject of significant interest especially when, upon chiral induction, the chiroptical response of the host/guest complex can effectively report the absolute configuration (AC) of the guest. For more than a decade, dimeric metalloporphyrin hosts (tweezers) have been successfully applied as chirality probes for determination of the AC for a wide variety of chiral synthetic compounds and natural products. The objective of this study is to investigate the utility of a new class of melamine-bridged Zn-porphyrin tweezers as sensitive AC reporters. A combined approach based on an experimental CD analysis and a theoretical prediction of the prevailing interporphyrin helicity demonstrates that these tweezers display favorable properties for chiral recognition. Herein, we discuss the application of the melamine-bridged tweezer to the chiral recognition of a diverse set of chiral guests, such as 1,2-diamines, α-amino-esters and amides, secondary alcohols, and 1,2-amino-alcohols. The bulky periphery and the presence of a rigid porphyrin linkage lead, in some cases, to a more enhanced CD sensitivity than that reported earlier with other tweezers. Copyright © 2011 Wiley-Liss, Inc.

Proposal and Development of a High Voltage Variable Frequency Alternating Current Power System for Hybrid Electric Aircraft

NASA Technical Reports Server (NTRS)

Sadey, David J.; Taylor, Linda M.; Beach, Raymond F.

2016-01-01

The development of ultra-efficient commercial vehicles and the transition to low-carbon emission propulsion are seen as thrust paths within NASA Aeronautics. A critical enabler to these paths comes in the form of hybrid-electric propulsion systems. For megawatt-class systems, the best power system topology for these hybrid-electric propulsion systems is debatable. Current proposals within NASA and the Aero community suggest using a combination of AC and DC for power transmission. This paper proposes an alternative to the current thought model through the use of a primarily high voltage AC power generation, transmission, and distribution systems, supported by the Convergent Aeronautics Solutions (CAS) Project. This system relies heavily on the use of dual-fed induction machines, which provide high power densities, minimal power conversion, and variable speed operation. The paper presents background on the project along with the system architecture, development status and preliminary results.

Research and simulation of the decoupling transformation in AC motor vector control

NASA Astrophysics Data System (ADS)

He, Jiaojiao; Zhao, Zhongjie; Liu, Ken; Zhang, Yongping; Yao, Tuozhong

2018-04-01

Permanent magnet synchronous motor (PMSM) is a nonlinear, strong coupling, multivariable complex object, and transformation decoupling can solve the coupling problem of permanent magnet synchronous motor. This paper gives a permanent magnet synchronous motor (PMSM) mathematical model, introduces the permanent magnet synchronous motor vector control coordinate transformation in the process of modal matrix inductance matrix transform through the matrix related knowledge of different coordinates of diagonalization, which makes the coupling between the independent, realize the control of motor current and excitation the torque current coupling separation, and derived the coordinate transformation matrix, the thought to solve the coupling problem of AC motor. Finally, in the Matlab/Simulink environment, through the establishment and combination between the PMSM ontology, coordinate conversion module, built the simulation model of permanent magnet synchronous motor vector control, introduces the model of each part, and analyzed the simulation results.

Effects of DC bias on magnetic performance of high grades grain-oriented silicon steels

NASA Astrophysics Data System (ADS)

Ma, Guang; Cheng, Ling; Lu, Licheng; Yang, Fuyao; Chen, Xin; Zhu, Chengzhi

2017-03-01

When high voltage direct current (HVDC) transmission adopting mono-polar ground return operation mode or unbalanced bipolar operation mode, the invasion of DC current into neutral point of alternating current (AC) transformer will cause core saturation, temperature increasing, and vibration acceleration. Based on the MPG-200D soft magnetic measurement system, the influence of DC bias on magnetic performance of 0.23 mm and 0.27 mm series (P1.7=0.70-1.05 W/kg, B8>1.89 T) grain-oriented (GO) silicon steels under condition of AC / DC hybrid excitation were systematically realized in this paper. For the high magnetic induction GO steels (core losses are the same), greater thickness can lead to stronger ability of resisting DC bias, and the reasons for it were analyzed. Finally, the magnetostriction and A-weighted magnetostriction velocity level of GO steel under DC biased magnetization were researched.

Effects of segmental traction therapy on lumbar disc herniation in patients with acute low back pain measured by magnetic resonance imaging: A single arm clinical trial.

PubMed

Karimi, Noureddin; Akbarov, Parvin; Rahnama, Leila

2017-01-01

Low Back Pain (LBP) is considered as one of the most frequent disorders, which about 80% of adults experience in their lives. Lumbar disc herniation (LDH) is a cause for acute LBP. Among conservative treatments, traction is frequently used by clinicians to manage LBP resulting from LDH. However, there is still a lack of consensus about its efficacy. The purpose of this study was to evaluate the effects of segmental traction therapy on lumbar discs herniation, pain, lumbar range of motion (ROM), and back extensor muscles endurance in patients with acute LBP induced by LDH. Fifteen patients with acute LBP diagnosed by LDH participated in the present study. Participants undertook 15 sessions of segmental traction therapy along with conventional physiotherapy, 5 times a week for 3 weeks. Lumbar herniated mass size was measured before and after the treatment protocol using magnetic resonance imaging. Furthermore, pain, lumbar ROM and back muscle endurance were evaluated before and after the procedure using clinical outcome measures. Following the treatment protocol, herniated mass size and patients' pain were reduced significantly. In addition, lumbar flexion ROM showed a significant improvement. However, no significant change was observed for back extensor muscle endurance after the treatment procedure. The result of the present study showed segmental traction therapy might play an important role in the treatment of acute LBP stimulated by LDH.

Surgical management of C-type subaxial cervical fractures using cervical traction followed by anterior cervical discectomy and fusion within 12 h after the trauma.

PubMed

Donnarumma, Pasquale; Bozzini, Vincenzo; Rizzi, Gaetano; Berardi, Arturo; Merlicco, Gaetano

2017-01-01

This was a retrospective cohort study. To report our 10-year experience of closed reduction using Crutchfield traction followed by anterior cervical discectomy and fusion within 12 h from injury for C-type subaxial cervical fractures (according to the AOSpine classification system). Clinical records and neuroimaging were retrospectively reviewed. Surgical details were provided. A total of 22 patients were included in the study. The cervical fracture was diagnosed after whole-body computed tomography scan on admission in all cases. Crutchfield traction was applied within 1-5 h from the diagnosis. Surgery consisting of anterior microdiscectomy and fusion with interbody cage and plating was performed 6-12 h after traction positioning. Most patients (19, 86%) had spinal cord injury: 7 were Frankel A (31%), 3 Frankel B (14%), 6 Frankel C (27%), 3 Frankel D (14%), and 3 Frankel E (14%). No neurologic deterioration was observed after the treatment. In 10 cases (45%), neurological symptoms improved 1 year after the trauma. Two patients (10%) died for complication related to spinal cord transition or other organ damage. Early reduction gives the best chance of recovery for patients affected by C-type subaxial cervical fracture. Rapid traction is more often successful and safer than manipulation under anesthesia. After close reduction achieving, anterior microdiscectomy, cage, and plating implant seem to be safe and effective with a low rate of complications.

The effect of cervical traction combined with neural mobilization on pain and disability in cervical radiculopathy. A case report.

PubMed

Savva, Christos; Giakas, Giannis

2013-10-01

Cervical radiculopathy is the result of cervical nerve root pathology that may lead to chronic pain and disability. Although manual therapy interventions including cervical traction and neural mobilization have been advocated to decrease pain and disability caused by cervical radiculopathy, their analgesic effect has been questioned due to the low quality of research evidence. The purpose of this paper is to present the effect of cervical traction combined with neural mobilization on pain and disability in a patient experiencing cervical radiculopathy. A 52-year-old woman presented with a 2 month history of neurological cervico-brachial pain and whose presentation was consistent with cervical radiculopathy. Cervical traction and a slider neural mobilization of the medial nerve were applied simultaneously to reduce the patient's pain and disability measured at baseline and at 2 and 4 weeks using the Numeric Pain Rating Scale, the Neck Disability Index and the Patient-Specific Functional Scale. Improvements in all outcome measures were noted over a period of four weeks. Scores in all outcome measures revealed that the patient's pain had almost disappeared and that she was able to perform her household chores and job tasks without difficulties and limitations. In conclusion, the findings of this study support that the application of cervical traction combined with neural mobilization can produce significant improvements in terms of pain and disability in cervical radiculopathy. Copyright © 2012 Elsevier Ltd. All rights reserved.

The history of modern spinal traction with particular reference to neural disorders.

PubMed

Shterenshis, M V

1997-03-01

The last 200 years of the history of spinal traction is described in the present article. The study starts at the end of the 18th century with the works of JA Venel (1789) who tried to apply the Hippocratic idea to modern surgery. Orthopedic specialists of the last century were mostly preoccupied with corsets and the method gained broader popularity when neurologists paid attention to the similar method of suspension. The Russian neurologist Osip Mochutkovsky described suspension as a method for the treatment of tabes dorsalis in an article published in the Russian magazine 'Vratch' in 1883. His works became known in Europe when JM Charcot paid attention to it and published a special short monograph on this subject in 1889. This work was translated into English (1889) and Russian (1890) and the method became popular in the treatment of tabes dorsalis and other neurological diseases. The eminent Russian neurologist VM Bekhterev proposed the combination of body suspension with cervical traction (1893). Some years later Gilles de la Tourette promoted the use of spinal traction in his neurological clinic (1897). Unfortunately neurologists worked without the cooperation of orthopedic specialists. During the first decades of the 20th century suspension was also replaced by traction in neurology. This method was used by both neurologists and orthopedic specialists but in the last decades neurologists lost their interests in it and it found greater use in traumatology and in spinal surgery where it is still in use today.

Mechanics of advancing pin-loaded contacts with friction

NASA Astrophysics Data System (ADS)

Sundaram, Narayan; Farris, T. N.

2010-11-01

This paper considers finite friction contact problems involving an elastic pin and an infinite elastic plate with a circular hole. Using a suitable class of Green's functions, the singular integral equations governing a very general class of conforming contact problems are formulated. In particular, remote plate stresses, pin loads, moments and distributed loading of the pin by conservative body forces are considered. Numerical solutions are presented for different partial slip load cases. In monotonic loading, the dependence of the tractions on the coefficient of friction is strongest when the contact is highly conforming. For less conforming contacts, the tractions are insensitive to an increase in the value of the friction coefficient above a certain threshold. The contact size and peak pressure in monotonic loading are only weakly dependent on the pin load distribution, with center loads leading to slightly higher peak pressure and lower peak shear than distributed loads. In contrast to half-plane cylinder fretting contacts, fretting behavior is quite different depending on whether or not the pin is allowed to rotate freely. If pin rotation is disallowed, the fretting tractions resemble half-plane fretting tractions in the weakly conforming regime but the contact resists sliding in the strongly conforming regime. If pin rotation is allowed, the shear traction behavior resembles planar rolling contacts in that one slip zone is dominant and the peak shear occurs at its edge. In this case, the effects of material dissimilarity in the strongly conforming regime are only secondary and the contact never goes into sliding. Fretting tractions in the forward and reversed load states show shape asymmetry, which persists with continued load cycling. Finally, the governing integro-differential equation for full sliding is derived; in the limiting case of no friction, the same equation governs contacts with center loading and uniform body force loading, resulting in identical pressures when their resultants are equal.

[Comparison of dressings and devices to secure peripheral venous catheters in the emergency department: suitability according to patient profile].

PubMed

Moreno Martín, Montserrat; Villamor Ordozgoiti, Alberto; Gutiérrez Martín, Montserrat; Santiago Bosch, Mercedes; Grau Ferrer, Helena; Gamero Saavedra, Tamara

2016-10-01

To identify the most suitably designed dressings and devices to secure peripheral venous catheters (PVCs) in different types of patients. To evaluate the traction force the dressings could withstand and times they are able to keep the PVC in place in the emergency department. Quasi-experimental descriptive observational study with inferential statistics to compare variables. We studied the designs of devices and dressings for securing PVCs in the emergency department (Omnifix, Tegaderm, Oper Dres, Steri-strip, and stopcocks) and special adaptations devised by the authors: A (Tegaderm), A1 (Tegaderm + Steristrip), A2 (Tegaderm + Oper Dres), B (Omnifix), C (Omnifix doubled). Participants carried out 520 tests on models of human patients to simulate standard, hairy, and hairy-sweaty skin. Costs were as follows: A, € 0.15; A1, € 0.35; A2, € 0.18; B, € 0.005; C, € 0.01. The times in seconds required to apply the dressings were as follows: (A, 15; A1, 25; A2, 20; B, 20; C, 35). The dressings withstood the following traction forces in grams: lengthwise, A, 760; B, 1694; C, 1530); perpendicular (A, 785; B, 1450; C, 3290), and transversal (A, 760; A1, 1220; A2, 1510; B, 1720; C, 2255). Design C was able to withstand greater forces in the traction tests. Extra surgical tape significantly improved resistance to traction when a stopcock was used. Using a Steri-strip with the Tegaderm device increased resistance to traction, although the improvement was less than that obtained with the Omnifix. The Tegaderm plus Omnifix design was significantly more resistant to traction than the Tegaderm by itself at only a slightly higher cost; the combination design, therefore, may be more recommendable. However, our results for resistance, cost, and application time showed that the Omnifix (desing B) is the best choice for securing a PVC.

Long-Life, Lightweight, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration

NASA Technical Reports Server (NTRS)

Klein, Richard C.; Fusaro, Robert L.; Dimofte, Florin

2012-01-01

NASA s initiative for Lunar and Martian exploration will require long lived, robust drive systems for manned vehicles that must operate in hostile environments. The operation of these mechanical drives will pose a problem because of the existing extreme operating conditions. Some of these extreme conditions include operating at a very high or very cold temperature, operating over a wide range of temperatures, operating in very dusty environments, operating in a very high radiation environment, and operating in possibly corrosive environments. Current drive systems use gears with various configurations of teeth. These gears must be lubricated with oil (or grease) and must have some sort of a lubricant resupply system. For drive systems, oil poses problems such as evaporation, becoming too viscous and eventually freezing at cold temperatures, being too thin to lubricate at high temperatures, being degraded by the radiation environment, being contaminated by the regolith (soil), and if vaporized (and not sealed), it will contaminate the regolith. Thus, it may not be advisable or even possible to use oil because of these limitations. An oil-less, compact traction vehicle drive is a drive designed for use in hostile environments like those that will be encountered on planetary surfaces. Initially, traction roller tests in vacuum were conducted to obtain traction and endurance data needed for designing the drives. From that data, a traction drive was designed that would fit into a prototype lunar rover vehicle, and this design data was used to construct several traction drives. These drives were then tested in air to determine their performance characteristics, and if any final corrections to the designs were necessary. A limitation with current speed reducer systems such as planetary gears and harmonic drives is the high-contact stresses that occur at tooth engagement and in the harmonic drive wave generator interface. These high stresses induce high wear of solid lubricant coatings, thus necessitating the use of liquid lubricants for long life.

[Randomized controlled trials of needle knife therapy combined with rotation traction manipulation for the treatment of cervical spondylotic radiculopathy].

PubMed

Zhou, Zhong-Liang; Su, Guo-Hong; Zheng, Bao-Zhu; Zuo, Yu-Zhu; Wei, Fu-Liang

2016-09-25

To compare the therapeutic effects between needle knife therapy combined with rotation traction manipulation and rotation traction manipulation for the treatment of cervical spondylotic radiculopathy. From November 2013 to June 2015, 80 patients with cervical spondylotic radiculopathy meeting the inclusion criteria were divided into two groups randomly:the control group in which 39 patients were treated with rotation traction manipulation, and the treatment group in which 41 patients were treated with needle knife combined with rotation traction manipulation. The patients in the control group were treated once dayly for 2 weeks, which was 1 course. The patients in the treatment group were treated with needle knife firstly once a week for 2 weeks, which was 1 course;then were treated with the same methods as the patients in the control group. The symptoms, signs score and the therapeutic effects of the two groups before and after treatment were observed. After treatment, symptoms and signs scores declined in both groups( P <0.05). The results of the treatment group were better than effects in the control group( P <0.05). In the treatment group, 19 patients got an excellent result, 16 good, 5 fair and 1 bad;while in the control group, 10 patients got an excellent result, 10 good, 16 fair and 3 bad;the results of the treatment group were better than the results of the control group( P <0.01). Needle knife combined with rotation traction manipulation is an effective method for the treatment of cervical spondylotic radiculopathy, which is better than using manipulation method simply. Needle knife therapy has follow advantages:improving local blood circulation, reducing local content of pain substance, increasing production of substances resisting pain, opening channels and collaterals, and make body reaching new static and dynamic balance on the new foundation.

Effects of Different Angles of the Traction Table on Lumbar Spine Ligaments: A Finite Element Study.

PubMed

Farajpour, Hekmat; Jamshidi, Nima

2017-12-01

The traction bed is a noninvasive device for treating lower back pain caused by herniated intervertebral discs. In this study, we investigated the impact of the traction bed on the lower back as a means of increasing the disc height and creating a gap between facet joints. Computed tomography (CT) images were obtained from a female volunteer and a three-dimensional (3D) model was created using software package MIMICs 17.0. Afterwards, the 3D model was analyzed in an analytical software (Abaqus 6.14). The study was conducted under the following traction loads: 25%, 45%, 55%, and 85% of the whole body weight in different angles. Results indicated that the loading angle in the L3-4 area had 36.8%, 57.4%, 55.32%, 49.8%, and 52.15% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 32.3%, 10.6%, 53.4%, 56.58%, and 57.35%. Also, the body weight had 63.2%, 42.6%, 44.68%, 50.2%, and 47.85% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 67.7%, 89.4%, 46.6%, 43.42% and 42.65%. The authenticity of results was checked by comparing with the experimental data. The results show that traction beds are highly effective for disc movement and lower back pain relief. Also, an optimal angle for traction can be obtained in a 3D model analysis using CT or magnetic resonance imaging images. The optimal angle would be different for different patients and thus should be determined based on the decreased height of the intervertebral disc, weight and height of patients.

A Hypothesis: Could Portable Natural Grass be a Risk Factor for Knee Injuries?

PubMed Central

Orchard, John; Rodas, Gil; Til, Lluis; ArdevÒl, Jordi; Chivers, Ian

2008-01-01

Previous study has shown a likely link between increased shoe- surface traction and risk of knee Anterior Cruciate Ligament (ACL) injury. Portable natural grass systems are being used more often in sport, but no study to date has investigated their relative safety. By their nature, they must have high resistance to falling apart and therefore newly laid systems may be at risk of creating excessive shoe-surface traction. This study describes two clusters of knee injuries (particularly non-contact ACL injuries), each occurring to players of one professional football team at single venue, using portable grass, in a short space of time. The first series included two ACL injuries, one posterolateral complex disruption and one lateral ligament tear occurring in two rugby league games on a portable bermudagrass surface in Brisbane, Australia. The second series included four non-contact ACL injuries over a period of ten weeks in professional soccer games on a portable Kentucky bluegrass/perennial ryegrass surface in Barcelona, Spain. Possible intrinsic risk factors are discussed but there was no common risk shared by the players. Although no measures of traction were made at the Brisbane venue, average rotational traction was measured towards the end of the injury cluster at Camp Nou, Barcelona, to be 48 Nm. Chance undoubtedly had a part to play in these clusters, but the only obvious common risk factor was play on a portable natural grass surface soon after it was laid. Further study is required to determine whether portable natural grass systems may exhibit high shoe-surface traction soon after being laid and whether this could be a risk factor for knee injury. Key pointsExcessive shoe-surface traction is a hypothesised risk factor for knee ligament injuries, including anterior cruciate ligament injuries.Portable natural grass systems (by their nature in order to prevent grass rolls or squares from falling apart) will tend to exhibit high resistance to tearing when first laid. This may lead to excessive shoe-surface traction.This dual case series describes two clusters of non-contact knee ligament injuries which occurred in circumstances of newly laid portable turf.Further research is warranted to undercover any link between non-contact knee ligament injuries and ground surfaces conditions. PMID:24150152

Hip arthroscopy. The lateral approach.

PubMed

Glick, J M

2001-10-01

The lateral approach provides an easy and safe access to the hip joint. The line from skin to the joint itself is a straight, downward drop (Fig. 18). The vital arteries and nerves are a safe distance from the portal sites. The potential problems that can arise from this procedure are from the traction applying a compression force on the branches of the pudendal nerve as they cross the ischium (Fig. 19) and traction force on the sciatic nerve. I have always maintained that traction should be treated like a tourniquet; that is, it should be applied for no more then 2 hours. [figure: see text] Furthermore, the amount of traction should not exceed 75 pounds. I use a tensiometer, but it is not mandatory because the major issue with traction is the duration of application. I have monitored the sciatic nerve using both evoke potentials and, in some cases, motor potentials in over 50 cases in the past year, and the poundage and time limits of the traction (75 pounds and 2 hours) were verified. In addition, if the fracture [figure: see text] table has a vertical post as well as a peroneal post, set the vertical post in the back of the patient, and not in the front. Flexing the hip around that post will greatly increase the traction and at the same time will place an extreme stretch on the sciatic nerve, setting up the chance of a significant sciatic nerve neuropraxia. To protect the pudendal nerve, Lyon et al suggest that the perineal post be at least 9 cm in diameter to distribute the forces in a wide area on the ischium and make sure that the pelvis is well supported so the pressure of the post is not placed directly on the this nerve. The perineal posts on most fracture tables are only 3 cm in diameter. These can be made larger by wrapping them with padding. In some fracture tables, the slats that support the lower leg can be removed, and consequently the support on the pelvis is lost. For hip arthroscopy, the slats do not have to be removed. The lateral approach provides a safe and simple way of performing hip arthroscopy. The instruments can be manipulated easily so that the entire confines of the joint can be visualized with the arthroscope and reached with operative instruments.

DICE: A novel tumor surveillance mechanism-a new therapy for cancer?

PubMed

Peter, Marcus E

2014-01-01

The conventional view of CD95 (Fas/APO-1) is that it is a dedicated apoptosis-inducing receptor with important functions in immune cell homeostasis and in viral and tumor defense. There is an emerging recognition, however, that CD95 also has multiple non-apoptotic activities. In the context of cancer, CD95 was shown to have tumor-promoting activities, and the concept of this new function of CD95 in cancer is gaining traction. Recently, we showed that not only is CD95 a growth promoter for cancer cells, but, paradoxically, when either CD95 or CD95 ligand (CD95L) is removed, that virtually all cancer cells die through a process we have named DICE (death induced by CD95R/L elimination). In this perspective, I outline a hypothesis regarding the physiological function of DICE, and why it may be possible to use induction of DICE to treat many, if not most, cancers.

Biomonitoring of traffic police officers exposed to airborne platinum

PubMed Central

Iavicoli, I; Bocca, B; Petrucci, F; Senofonte, O; Carelli, G; Alimonti, A; Caroli, S

2004-01-01

Background: Over the past two decades there has been a substantial increase in environmental levels of palladium, platinum, and rhodium, the platinum group elements (PGEs), due to the widespread use of catalytic converters for automotive traction. Aim: To evaluate urinary platinum levels in occupationally exposed subjects. Methods: A total of 161 employees from the Rome City Police Force were studied; 103 were traffic police involved in controlling streets with an average flow of vehicles, while the remaining 58 were control subjects engaged only in office work. Platinum quantification in the urine samples of these subjects was carried out by sector field inductively coupled plasma mass spectrometry. Results: There were no statistically significant differences between platinum levels in the group of subjects engaged in traffic control and the control group (4.45 (2.42) ng/l v 4.56 (2.84) ng/l, respectively). Conclusions: Urinary levels were found to be higher than those reported for other urban populations, thus showing a progressive increase in human exposure to Pt. PMID:15208381

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.

Functionalized guanidinium chloride based colourimetric sensors for fluoride and acetate: single crystal X-ray structural evidence of -NH deprotonation and complexation.

PubMed

Bose, Purnandhu; Ahamed, B Nisar; Ghosh, Pradyut

2011-03-21

A series of new symmetrically functionalized guanidinium chlorides (S1-S10) are synthesized in good yields and their sensing ability toward anions is studied in MeCN-DMF (24 : 1) (v/v). The absorption bands of these molecules in the presence of anions are tuned by varying the functional groups attached to the guanidinium moiety (which resembles urea) with respect to (i) aromaticity (S1-S4), (ii) electron induction effect (S1, S5-S9), (iii) positional isomeric effect (S7-S9), (iv) indole functionality (S10) of the conjugated aryl units. Anions that are above Cl(-) in the Hofmeister series (F(-), AcO(-), H(2)PO(4)(-)) are eligible as an analyte in this series of molecules whereas less basic anions than Cl(-) do not cause any interference. Thus, this series of molecules are suitable for the detection of anions in the narrow window of the Hofmeister series. Out of all the anions, only fluoride causes vivid colour changes from yellow to red to reddish orange and finally to blue, irrespective of the increasing aromaticity, induction and positional isomeric effect of the substituent that is attached to the guanidinium moiety. Interestingly, S9 has shown the ability to sense distinctly both F(-) and AcO(-) colourimetrically. Further S10, a sensor attached with indole functionality shows selective sensing of F(-) colourimetrically with a NIR signature at ∼930 nm though both these outputs are very unstable in nature. Stability constants for complex formation of S1-S10 (except S5) with F(-), AcO(-) are calculated by UV-vis titration experiments. Finally single crystal X-ray structural studies on the species 1 formed upon treating S6 with sodium fluoride confirms -NH deprotonation, whereas the reaction of S6 and S2 with sodium benzoate shows 1:1 host:guest binding that results in complexes 2 and 3 respectively.

Impact of Staphylococcus epidermidis lysates on middle ear epithelial proinflammatory and mucogenic response.

PubMed

Val, Stéphanie; Mubeen, Humaira; Tomney, Amarel; Chen, Saisai; Preciado, Diego

2015-02-01

Chronic otitis media with effusion (COME) develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Staphylococcus epidermidis, typically considered a commensal organism, is very frequently recovered in chronic middle ear fluid and in middle ear biofilms. Although it has been shown to drive inflammation in sinonasal epithelium, the impact of S. epidermidis on COME is markedly understudied. The goal of this study was to examine the in vitro effects of S. epidermidis lysates on murine and human middle ear epithelial cells. Staphylococcus epidermidis lysates were generated and used to stimulate submerged and differentiated human and murine epithelial cells (MEECs) for 24 to 48 hours. Quantitative real time-polymerase chain reaction, Western blot, enzyme-linked immunosorbent assay, and immunocytochemistry techniques were performed to interrogate the mucin gene MUC5AC and MUC5B expression and protein production, chemokine response, as well as NF-κB activation. Luciferase reporter assays were performed to further evaluate nuclear factor κB (NF-κB) activation and query specific promoter responses after S. epidermidis exposure. Staphylococcus epidermidis induced a time- and dose-dependent MUC5AC and MUC5B overexpression along with a parallel overexpression of Cxcl2 in mouse MEEC and IL-8 in human MEEC. Further investigations in mMEEC showed a 1.3 to 1.5 induction of the MUC5AC and MUC5B promoters. As potential mechanisms for these responses, induction of an oxidative stress marker, along with early nuclear translocation and activation of NF-κB, was found. Finally, chronic exposure induced marked epithelial thickening of cells differentiated at the air liquid interface. Staphylococcus epidermidis lysates activate a proinflammatory response in MEEC, including mucin gene expression and protein production. Although typically considered a nonpathogenic commensal organism in the ear, these results suggest that they may play a role in the perpetuation of an inflammatory and mucogenic response in COME.

Randomized Trial of Interleukin-2 (IL-2) as Early Consolidation Following Marrow Ablative Therapy with Stem Cell Rescue for Matastatic Breast Cancer

DTIC Science & Technology

2007-10-01

survival, with minimal toxicity. Effectiveness of this approach may correlate with the effective induction of LAK precursor and effector cells, as...and safe after AC+T chemotherapy and is showing a promising effect on breast cancer relapses. This regimen should be further evaluated in high-risk...1337 Diarrhea, hypoglycemia, hypocalcemia , stomatitis, skin irritation (port), nasal congestion, chest pain fatigue, dyspnea S-W 40 T2 N1biv

AC induction field heating of graphite foam

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

Klett, James W.; Rios, Orlando; Kisner, Roger

A magneto-energy apparatus includes an electromagnetic field source for generating a time-varying electromagnetic field. A graphite foam conductor is disposed within the electromagnetic field. The graphite foam when exposed to the time-varying electromagnetic field conducts an induced electric current, the electric current heating the graphite foam. An energy conversion device utilizes heat energy from the heated graphite foam to perform a heat energy consuming function. A device for heating a fluid and a method of converting energy are also disclosed.

Quinone-induced protein handling changes: Implications for major protein handling systems in quinone-mediated toxicity

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

Xiong, Rui; Siegel, David; Ross, David, E-mail: david.ross@ucdenver.edu

2014-10-15

Para-quinones such as 1,4-Benzoquinone (BQ) and menadione (MD) and ortho-quinones including the oxidation products of catecholamines, are derived from xenobiotics as well as endogenous molecules. The effects of quinones on major protein handling systems in cells; the 20/26S proteasome, the ER stress response, autophagy, chaperone proteins and aggresome formation, have not been investigated in a systematic manner. Both BQ and aminochrome (AC) inhibited proteasomal activity and activated the ER stress response and autophagy in rat dopaminergic N27 cells. AC also induced aggresome formation while MD had little effect on any protein handling systems in N27 cells. The effect of NQO1more » on quinone induced protein handling changes and toxicity was examined using N27 cells stably transfected with NQO1 to generate an isogenic NQO1-overexpressing line. NQO1 protected against BQ–induced apoptosis but led to a potentiation of AC- and MD-induced apoptosis. Modulation of quinone-induced apoptosis in N27 and NQO1-overexpressing cells correlated only with changes in the ER stress response and not with changes in other protein handling systems. These data suggested that NQO1 modulated the ER stress response to potentiate toxicity of AC and MD, but protected against BQ toxicity. We further demonstrated that NQO1 mediated reduction to unstable hydroquinones and subsequent redox cycling was important for the activation of the ER stress response and toxicity for both AC and MD. In summary, our data demonstrate that quinone-specific changes in protein handling are evident in N27 cells and the induction of the ER stress response is associated with quinone-mediated toxicity. - Highlights: • Unstable hydroquinones contributed to quinone-induced ER stress and toxicity.« less

Superconductor disks and cylinders in an axial magnetic field: II. Nonlinear and linear ac susceptibilities

NASA Astrophysics Data System (ADS)

Brandt, Ernst Helmut

1998-09-01

The ac susceptibility χ=χ'-iχ'' of superconductor cylinders of finite length in a magnetic field applied along the cylinder axis is calculated using the method developed in the preceding paper, part I. This method does not require any approximation of the infinitely extended magnetic field outside the cylinder or disk but directly computes the current density J inside the superconductor. The material is characterized by a general current-voltage law E(J), e.g., E(J)=Ec[J/Jc(B)]n(B), where E is the electric field, B=μ0H the magnetic induction, Ec a prefactor, Jc the critical current density, and n>=1 the creep exponent. For n>1, the nonlinear ac susceptibility is calculated from the hysteresis loops of the magnetic moment of the cylinder, which is obtained by time integration of the equation for J(r,t). For n>>1 these results go over into the Bean critical state model. For n=1, and for any linear complex resistivity ρac(ω)=E/J, the linear ac susceptibility is calculated from an eigenvalue problem which depends on the aspect ratio b/a of the cylinder or disk. In the limits b/a<<1 and b/a>>1, the known results for thin disks in a perpendicular field and long cylinders in a parallel field are reproduced. For thin disks in a perpendicular field, at large frequencies χ(ω) crosses over to the behavior of slabs in parallel geometry since the magnetic field lines are expelled and have to flow around the disk. The results presented may be used to obtain the nonlinear or linear resistivity from contact-free magnetic measurements on superconductors of realistic shape.

Polyamine-induced modulation of genes involved in ethylene biosynthesis and signalling pathways and nitric oxide production during olive mature fruit abscission

PubMed Central

Parra-Lobato, Maria C.; Gomez-Jimenez, Maria C.

2011-01-01

After fruit ripening, many fruit-tree species undergo massive natural fruit abscission. Olive (Olea europaea L.) is a stone-fruit with cultivars such as Picual (PIC) and Arbequina (ARB) which differ in mature fruit abscission potential. Ethylene (ET) is associated with abscission, but its role during mature fruit abscission remains largely uncharacterized. The present study investigates the possible roles of ET and polyamine (PA) during mature fruit abscission by modulating genes involved in the ET signalling and biosynthesis pathways in the abscission zone (AZ) of both cultivars. Five ET-related genes (OeACS2, OeACO2, OeCTR1, OeERS1, and OeEIL2) were isolated in the AZ and adjacent cells (AZ–AC), and their expression in various olive organs and during mature fruit abscission, in relation to interactions between ET and PA and the expression induction of these genes, was determined. OeACS2, OeACO2, and OeEIL2 were found to be the only genes that were up-regulated in association with mature fruit abscission. Using the inhibition of ET and PA biosynthesis, it is demonstrated that OeACS2 and OeEIL2 expression are under the negative control of PA while ET induces their expression in AZ–AC. Furthermore, mature fruit abscission depressed nitric oxide (NO) production present mainly in the epidermal cells and xylem of the AZ. Also, NO production was differentially responsive to ET, PA, and different inhibitors. Taken together, the results indicate that PA-dependent ET signalling and biosynthesis pathways participate, at least partially, during mature fruit abscission, and that endogenous NO and 1-aminocyclopropane-1-carboxylic acid maintain an inverse correlation, suggesting an antagonistic action of NO and ET in abscission signalling. PMID:21633085

Wireless power transfer electric vehicle supply equipment installation and validation tool

DOEpatents

Jones, Perry T.; Miller, John M.

2015-05-19

A transmit pad inspection device includes a magnetic coupling device, which includes an inductive circuit that is configured to magnetically couple to a primary circuit of a charging device in a transmit pad through an alternating current (AC) magnetic field. The inductive circuit functions as a secondary circuit for a set of magnetically coupled coils. The magnetic coupling device further includes a rectification circuit, and includes a controllable load bank or is configured to be connected to an external controllable load back. The transmit pad inspection device is configured to determine the efficiency of power transfer under various coupling conditions. In addition, the transmit pad inspection device can be configured to measure residual magnetic field and the frequency of the input current, and to determine whether the charging device has been installed properly.

High pressure, high current, low inductance, high reliability sealed terminals

DOEpatents

Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

2010-03-23

The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.