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1

Torque  

NSDL National Science Digital Library

The simulation of a rotating wheel below shows the relationship between net torque on the wheel and its angular acceleration. The center of the wheel is fixed so that the net external force on the wheel remains zero.

Wolfgang Christian

2

Torque Production in a Halbach Machine  

NASA Technical Reports Server (NTRS)

The NASA John H. Glenn Research Center initiated the investigation of torque production in a Halbach machine for the Levitated Ducted Fan (LDF) Project to obtain empirical data in determining the feasibility of using a Halbach motor for the project. LDF is a breakthrough technology for "Electric Flight" with the development of a clean, quiet, electric propulsor system. Benefits include zero emissions, decreased dependence on fossil fuels, increased efficiency, increased reliability, reduced maintenance, and decreased operating noise levels. A commercial permanent magnet brushless motor rotor was tested with a custom stator. An innovative rotor utilizing a Halbach array was designed and developed to fit directly into the same stator. The magnets are oriented at 90deg to the adjacent magnet, which cancels the magnetic field on the inside of the rotor and strengthens the field on the outside of the rotor. A direct comparison of the commercial rotor and the Halbach rotor was made. In addition, various test models were designed and developed to validate the basic principles described, and the theoretical work that was performed. The report concludes that a Halbach array based motor can provide significant improvements in electric motor performance and reliability.

Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.; Vrnak, Daniel R.

2006-01-01

3

Maximal Torque and Muscle Strength is Affected by Seat Distance from the Steering Wheel when Driving.  

PubMed

[Purpose] This research analyzed how seat distance and gender affect maximal torque and muscle strength when driving to present base data for the optimal driving posture. [Subjects and Methods] The subjects were 27 college students in their 20's, 15 males and 12 females. After had been measured, the subjects sat in front of a steering wheel with the distance between the steering wheel and the seat set in turns. at 50, 70, and 90% their arm length, and the maximal torque and muscle strength were measured. [Results] Both the maximal torque and muscle strength were found to be greater in male subjects than female subjects whether they turned the steering wheel clockwise or counterclockwise. The difference was big enough to be statistically significant. Maximal torque was greatest when the seat distance was 50% of arm length, whether turning the steering wheel clockwise or counterclockwise. There were statistically significant differences in maximal torque between seat distances of 50 and 70% and 90% of the arm length. Muscle strength, in contrast, was found to be the greatest at a seat distance of 70% of arm length. [Conclusion] We conclude that greater torque can be obtained when the steering wheel is nearer the seat while greater muscle strength can be obtained when the seat distance from the steering wheel is 70% of the arm length. PMID:24259937

Yoo, Kyung-Tae; An, Ho-Jung; Lee, Sun-Kyung; Choi, Jung-Hyun

2013-09-01

4

Torque Production in Permanent-Magnet Synchronous Motor Drives with Rectangular Current Excitation  

Microsoft Academic Search

Special features of torque production in self-controlled permanent-magnet (PM) synchronous motor drives with rectangular current excitation have been investigated. Addressed issues include the generation of undesired torque pulsations at low speeds and system operating locus limits imposed at high speeds by saturation of the current regulator. Attention is limited to motors in which sources of reluctance torque are suppressed by

Thomas M. Jahns

1984-01-01

5

How Joint Torques Affect Hamstring Injury Risk in Sprinting Swing–Stance Transition  

PubMed Central

ABSTRACT Purpose The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases. PMID:24911288

SUN, YULIANG; WEI, SHUTAO; ZHONG, YUNJIAN; FU, WEIJIE; LI, LI; LIU, YU

2015-01-01

6

Affective Productions of Mathematical Experience  

ERIC Educational Resources Information Center

In underscoring the affective elements of mathematics experience, we work with contemporary readings of the work of Spinoza on the politics of affect, to understand what is included in the cognitive repertoire of the Subject. We draw on those resources to tell a pedagogical tale about the relation between cognition and affect in settings of…

Walshaw, Margaret; Brown, Tony

2012-01-01

7

Isometric Knee-Extension and Knee-Flexion Torque Production During Early Follicular and Postovulatory Phases in Recreationally Active Women  

PubMed Central

Abstract Context: Acute decreases in strength have been associated with risky biomechanical strategies that might predispose one to injury. Whether acute changes in thigh muscle torque occur across the menstrual cycle remains equivocal. Objective: We compared maximal voluntary isometric contraction (MVIC) torque of the knee flexors and extensors between the early follicular (EF) and either the early luteal (EL) or midluteal (ML) phases, which were confirmed by serum hormone concentrations. We expected that MVIC torques would increase from the EF to the EL phase after estradiol peaked and before increased exposure to progesterone. Design: Cohort study. Setting: Applied Neuromechanics Research Laboratory. Patients or Other Participants: Seventy-one recreationally active women (age range, 18–30 years). Intervention(s): The MVICs were measured 1 day during menses and 1 day during the 8 days after ovulation. Participants were grouped by the hormone profile of their luteal test days as EL phase, ML phase, or anovulatory cycle. Main Outcome Measure(s): The MVIC torque of knee flexors and extensors (Nm/kg), estradiol (pg/mL), progesterone (ng/mL), and testosterone (ng/dL). Results: We tested 29 women during their EL phases, 32 during their ML phases, and 10 during anovulatory cycles. Although we observed relatively large individual changes in sex hormone concentrations and MVIC torques across the 2 test sessions, we observed no difference in MVIC torque between test phases (F1,68 ?=? 1.17, P ?=? .28) or among groups by test phase (F2,68 ?=? 0.31, P ?=? .74). Conclusions: Thigh MVIC torque did not change from time of menses (when estradiol and progesterone were lowest) to time in the luteal phase after an unopposed estradiol rise or combined estradiol and progesterone rise. However, these findings were limited to MVIC torque production measured at 2 different times, and further research examining these relationships at multiple times and using other measures of neuromuscular function is needed. PMID:21062182

Montgomery, Melissa M.; Shultz, Sandra J.

2010-01-01

8

Management Practices Affect Production and Profitability  

E-print Network

Management Practices Affect Production and Profitability Historically, the level of net returns, and a pharmaceutical company. The program was developed to improve profitability and sustainability of beef cow

9

The effect of using a laptopstation compared to using a standard laptop PC on the cervical spine torque, perceived strain and productivity.  

PubMed

The objective of this study was to assess the effect of using a laptopstation and a laptop PC and how this difference in work set-up affected the mechanical load on the neck (C7-Th1 segment), the subjective evaluation of strain on the neck and productivity. Ten healthy male students at Umeå University, Sweden with an average of 10 years of PC work experience and an average of 18 months of laptop PC work experience participated in the study. For each research subject measurements were divided into two parts; sitting working at the ErgoQ laptopstation in test situation A, and sitting working at a conventional laptop PC, test situation B. Each part took 4h and was scheduled on two consecutive days. Photography and biomechanical analysis was used to calculate the torque at the neck. To examine perceived strain the Borg Scale was used and to assess performance a productivity score was calculated. The results in the study demonstrated a significant (p<0.05) difference with the use of the laptopstation resulting in decreased torque at the C7-Th1 segment, less perceived strain at the neck and a higher productivity score. In conclusion, the results of the study confirm the importance of adjustable work tools that recognize anthropometric differences and biomechanics to meet the needs of individual customers during continuous visual display terminal work. PMID:15105076

Berkhout, Anna Lindblad; Hendriksson-Larsén, Karin; Bongers, Paulien

2004-03-01

10

Robot-assisted torque measurement  

Microsoft Academic Search

An Intelledex 605T robot was used to evaluate the feasibility of automating the measurement of rotary solenoid torque, with the goal of improving productivity. The solenoid chosen for the evaluation is expected to be produced in relatively large quantities for several programs. A new measurement concept was devised, in which the robot connects the solenoid shaft to a torque sensor,

Lembke

1986-01-01

11

Electric Field Driven Torque in ATP Synthase  

PubMed Central

FO-ATP synthase (FO) is a rotary motor that converts potential energy from ions, usually protons, moving from high- to low-potential sides of a membrane into torque and rotary motion. Here we propose a mechanism whereby electric fields emanating from the proton entry and exit channels act on asymmetric charge distributions in the c-ring, due to protonated and deprotonated sites, and drive it to rotate. The model predicts a scaling between time-averaged torque and proton motive force, which can be hindered by mutations that adversely affect the channels. The torque created by the c-ring of FO drives the ?-subunit to rotate within the ATP-producing complex (F1) overcoming, with the aid of thermal fluctuations, an opposing torque that rises and falls with angular position. Using the analogy with thermal Brownian motion of a particle in a tilted washboard potential, we compute ATP production rates vs. proton motive force. The latter shows a minimum, needed to drive ATP production, which scales inversely with the number of proton binding sites on the c-ring. PMID:24040370

Miller, John H.; Rajapakshe, Kimal I.; Infante, Hans L.; Claycomb, James R.

2013-01-01

12

Torque-Summing Brushless Motor  

NASA Technical Reports Server (NTRS)

Torque channels function cooperatively but electrically independent for reliability. Brushless, electronically-commutated dc motor sums electromagnetic torques on four channels and applies them to single shaft. Motor operates with any combination of channels and continues if one or more of channels fail electrically. Motor employs single stator and rotor and mechanically simple; however, each of channels electrically isolated from other so that failure of one does not adversely affect others.

Vaidya, J. G.

1986-01-01

13

Thermomagnetic Torque in Nh3  

E-print Network

, the magnetic field Hp for each pressure P is given by Hp ?-b(P+a), where a=-4. 4&&10 3 Torr and b=3. 18&&103 Oe/Torr. INTRODUCTION In 1967 Scott, Sturner, and Williamson' opened an exciting new field with the discovery of a thermo- magnetic torque on a..., conclude that the product of torque times pressure (vP) should be a u'niversal function of the field di- vided by pressure (H/P). Van Dael' has confirmed this with measurements in nitrogen gas. It has been pointed out by Beenakker that torque...

Adair, Thomas W.; McClurg, G. R.

1970-01-01

14

Establishing a relationship between maximum torque production of isolated joints to simulate EVA ratchet push-pull maneuver: A case study  

NASA Technical Reports Server (NTRS)

As manned exploration of space continues, analytical evaluation of human strength characteristics is critical. These extraterrestrial environments will spawn issues of human performance which will impact the designs of tools, work spaces, and space vehicles. Computer modeling is an effective method of correlating human biomechanical and anthropometric data with models of space structures and human work spaces. The aim of this study is to provide biomechanical data from isolated joints to be utilized in a computer modeling system for calculating torque resulting from any upper extremity motions: in this study, the ratchet wrench push-pull operation (a typical extravehicular activity task). Established here are mathematical relationships used to calculate maximum torque production of isolated upper extremity joints. These relationships are a function of joint angle and joint velocity.

Pandya, Abhilash; Maida, James; Hasson, Scott; Greenisen, Michael; Woolford, Barbara

1993-01-01

15

The effect of hand-grip stabilization on isokinetic torque at the knee.  

PubMed

Isokinetic dynamometers commonly measure muscle strength during conditioning and rehabilitation. Previous studies have shown that stabilization can affect isokinetic torque production. However, the effect of stabilization with hand-grip use has not been examined, and there are inconsistencies in the literature regarding its use. Fifteen men (mean age +/- SD = 24 +/- 3 years, height = 187 +/- 6 cm, mass = 84 +/- 10 kg) and 15 women (age = 25 +/- 4 years, height = 167 +/- 8 cm, mass = 62 +/- 6 kg) were tested on a Cybex 6000 dynamometer. Torque and joint angle signals, as well as quadriceps and hamstrings electromyographic (EMG) signals, were recorded during maximal knee flexion/extension at speeds of 60, 180, and 300 degrees x s(-1). Subjects performed the testing both with (stabilized) and without (nonstabilized with arms folded across the chest) hand-grip use. Repeated-measures analysis of variance (ANOVA) revealed a significant-motion (flexion, extension), X-condition (stabilized, non-stabilized) interaction in the data from the men in which hand-grip stabilization resulted in an 8.4% increase in knee extensor torque vs. a 0.2% increase in knee flexor torque. Stabilization did not significantly affect torque in women. The EMG analyses did not indicate a significant change in either agonist drive or antagonist cocontraction that accounted for the enhanced torque output with hand-grip use. This study found that hand-grip use enhanced knee extension maximal torque in men, but did not affect torque in women. The EMG data did not account for the changes in the torque data. Differences between men and women may have been due to mechanical factors and grip strength. These results indicate that hand-grip use needs to be considered when examining gender differences in knee strength and when studying knee flexion-extension ratios. PMID:11710668

Stumbo, T A; Merriam, S; Nies, K; Smith, A; Spurgeon, D; Weir, J P

2001-08-01

16

Measurements of magnetism-related forces and torque moments affecting medical instruments, implants, and foreign objects during magnetic resonance imaging at all degrees of freedom.  

PubMed

We designed a novel force/torque moment transducer with six degrees of freedom. This new sensor is used for measuring the forces and torque moments exerted by static magnetic resonance imaging (MRI) fields on various medical implants, instruments, and ballistic shell fragments. To determine the location of strongest effect the inhomogeneity of the magnetic field between the entrance of the MRI-tube (portal), and the imaging section was measured. Force and torque moments of a sample of 45 objects were measured at two positions, at the portal, and in the center of the imaging section. We classified the objects regarding to the magnetism-related forces measured in the homogeneous part of the MRI tube. About one-third of the objects was non- or weakly magnetic, one-third moderately, and the last third was strongly magnetic. Forces within the inhomogeneous area of the magnetic field at the entrance part of the tube were up to half a magnitude larger than forces inside the homogeneous imaging section. Here the greatest potential risks to patients might occur. PMID:8798170

Planert, J; Modler, H; Vosshenrich, R

1996-06-01

17

Radiative torques alignment in the presence of pinwheel torques  

E-print Network

We study the alignment of grains by radiative torques and pinwheel torques taking into account internal relaxations and thermal flipping. We identify with radiative torques the torques arising from anisotropic radiation, while all torques that are fixed in grain body axes, including the radiative torques arising from extinction of isotropic radiative field, we identify with pinwheel torques. We discuss new type of pinwheel torques, namely, regular torques arising from grain emission, as well as, pinwheel torques arising from the interaction of grains electrons in hot plasma. We show that both types of torques are long-lived, i.e. may exist longer than the grain damping time. We also show that the torques, first introduced by E. Purcell, arising from photoelectric emission of electrons, can also be long-lived. The other two types of Purcell's torques, namely, those arising from H$_2$ formation and variations of the grain accommodation coefficient, we identify with short-lived torques, although their actual lif...

Hoang, T

2008-01-01

18

Web-Based Foreign Language Reading: Affective and Productive Outcomes  

ERIC Educational Resources Information Center

This study aimed to investigate whether pedagogically guided web-based reading can improve skimming and scanning significantly (i.e., increased productive outcomes) and whether it can enhance student participation and motivation (i.e., increased affective outcomes). Forty-six students enrolled in two German 3 classes at the high school level were…

Lueck, Kerstin

2008-01-01

19

The production of a low-energy proton beam as a source of torque for a confined electron plasma  

NASA Astrophysics Data System (ADS)

A nonneutral plasma stored in a Penning-Malmberg trap takes the shape of a long cylinder of charge that rotates about the axial magnetic field of the confining solenoid. In the absence of external torques a plasma should survive indefinitely, but trap asymmetry and imperfect vacuum provide torques opposing the plasma's rotation which leads to plasma radial expansion and eventual loss. This dissertation will describe a plan for a new method of injecting angular momentum to counter these torques through the use of a low-energy (2--10keV) proton beam. A commercial duoplasmatron, operated far below its designed extraction voltage, provides a proton beam that is transported to the 1.6T solenoid field where it is to be displaced and then inflected by a sudden impulse onto an offset helical trajectory of low pitch. As the helical beam makes its way along the length of the plasma, the interaction of the faster-moving beam protons with plasma electrons allows for the transfer of angular momentum to the plasma. The low-energy beam delivered to the trap must have a sub-millimeter diameter to be compatible with impulsive inflection. The beam preparation system used to provide this beam will be described in detail in the dissertation. Electrostatic and magnetic lenses are modeled to understand their focusing and aberration properties, and further simulations are used to describe and optimize methods of aberration reduction. A newly designed electrostatic lens that corrects the beam aberration introduced by other lenses in the system is discussed, and data are given showing the improvement in beam quality. Beam density scans that display a hollowing of an intense beam immediately after passing through a waist are given and computational results are provided that explain this effect. Computer simulations of the dynamics of the beam are shown as it enters the trap, is displaced, and is inflected, as are simulations of the type needed for modeling of the interaction of the beam with the plasma.

Todd, Damon

20

Angular Acceleration without Torque?  

ERIC Educational Resources Information Center

Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

Kaufman, Richard D.

2012-01-01

21

Polarity-dependent dielectric torque in nematic liquid crystals  

E-print Network

The dielectric dispersion in the uniaxial nematic liquid crystals affects the switching dynamics of the director, as the dielectric torque is determined by not only the present values of the electric field and director but also by their past values. We demonstrate that this dielectric memory leads to an unusual contribution to the dielectric torque that is linear in the present field and thus polarity-sensitive. This torque can be used to accelerate the switch-off phase of director dynamics.

Mingxia Gu; Sergij V. Shiyanovskii; Oleg D. Lavrentovich

2008-03-24

22

Autonomous torque ripple compensation of DD motor by torque observer  

Microsoft Academic Search

From a standpoint of effective torque transmission, the direct drive motor (DDM) is advantageous over conventional AC servomotors because it does not require a reduction gear. The paper presents autonomous torque ripple compensation of the DDM with a permanent magnet rotor by using a software-implemented torque observer. The torque observer is also applicable to an estimation of equivalent moment of

Nobuyuki Matsui

1993-01-01

23

Dynamic Torque Calibration Unit  

NASA Technical Reports Server (NTRS)

Proposed dynamic torque calibration unit (DTCU) measures torque in rotary actuator components such as motors, bearings, gear trains, and flex couplings. Unique because designed specifically for testing components under low rates. Measures torque in device under test during controlled steady rotation or oscillation. Rotor oriented vertically, supported by upper angular-contact bearing and lower radial-contact bearing that floats axially to prevent thermal expansion from loading bearings. High-load capacity air bearing available to replace ball bearings when higher load capacity or reduction in rate noise required.

Agronin, Michael L.; Marchetto, Carl A.

1989-01-01

24

Space Suit Joint Torque Testing  

NASA Technical Reports Server (NTRS)

In 2009 and early 2010, a test was performed to quantify the torque required to manipulate joints in several existing operational and prototype space suits in an effort to develop joint torque requirements appropriate for a new Constellation Program space suit system. The same test method was levied on the Constellation space suit contractors to verify that their suit design meets the requirements. However, because the original test was set up and conducted by a single test operator there was some question as to whether this method was repeatable enough to be considered a standard verification method for Constellation or other future space suits. In order to validate the method itself, a representative subset of the previous test was repeated, using the same information that would be available to space suit contractors, but set up and conducted by someone not familiar with the previous test. The resultant data was compared using graphical and statistical analysis and a variance in torque values for some of the tested joints was apparent. Potential variables that could have affected the data were identified and re-testing was conducted in an attempt to eliminate these variables. The results of the retest will be used to determine if further testing and modification is necessary before the method can be validated.

Valish, Dana J.

2011-01-01

25

Environmental Factors Affecting Indole Production in Escherichia coli  

PubMed Central

A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole as an intracellular signal in microbial communities. Biosynthesis of indole is well-studied, and while carbon sources and amino acids are important environmental cues for indole production in Escherichia coli, other environmental factors affecting indole production for this strain are less clear. This study demonstrates that the environmental cue pH is an important factor for indole production that further controls biofilm formation of E. coli. Moreover, E. coli produced a higher level of extracellular indole in the presence of the antibiotics ampicillin and kanamycin, and the increased indole enhanced cell survival during antibiotic stress. Additionally, we found here that temperature is another important factor for indole production; E. coli produces and accumulates a large amount of indole at 50°C, even at low cell densities. Overall, our results suggest that indole is a stable biological compound, and E. coli may utilize indole to protect itself against other microorganisms. PMID:21145393

Han, Thi Hiep; Lee, Jin-Hyung; Cho, Moo Hwan; Wood, Thomas K.; Lee, Jintae

2011-01-01

26

Fabricated torque shaft  

DOEpatents

A fabricated torque shaft is provided that features a bolt-together design to allow vane schedule revisions with minimal hardware cost. The bolt-together design further facilitates on-site vane schedule revisions with parts that are comparatively small. The fabricated torque shaft also accommodates stage schedules that are different one from another in non-linear inter-relationships as well as non-linear schedules for a particular stage of vanes.

Mashey, Thomas Charles (Anderson, SC)

2002-01-01

27

Displaceable Gear Torque Controlled Driver  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

Cook, Joseph S., Jr. (Inventor)

1997-01-01

28

Radiative torques alignment in the presence of pinwheel torques  

E-print Network

We study the alignment of grains subject to both radiative torques and pinwheel torques while accounting for thermal flipping of grains. By pinwheel torques we refer to all systematic torques that are fixed in grain body axes, including the radiative torques arising from scattering and absorption of isotropic radiation. We discuss new types of pinwheel torques, which are systematic torques arising from infrared emission and torques arising from the interaction of grains with ions and electrons in hot plasma. We show that both types of torques are long-lived, i.e. may exist longer than gaseous damping time. We compare these torques with the torques introduced by E. Purcell, namely, torques due to H$_2$ formation, the variation of accommodation coefficient for gaseous collisions and photoelectric emission. Furthermore, we revise the Lazarian & Draine model for grain thermal flipping. We calculate mean flipping timescale induced by Barnett and nuclear relaxation for both paramagnetic and superparamagnetic grains, in the presence of stochastic torques associated with pinwheel torques, e.g. the stochastic torques arising from H$_2$ formation, and gas bombardment. We show that the combined effect of internal relaxation and stochastic torques can result in fast flipping for sufficiently small grains and, because of this, they get thermally trapped, i.e. rotate thermally in spite of the presence of pinwheel torques. For sufficiently large grains, we show that the pinwheel torques can increase the degree of grain alignment achievable with the radiative torques by increasing the magnitude of the angular momentum of low attractor points and/or by driving grains to new high attractor points.

T. Hoang; A. Lazarian

2008-01-01

29

RADIATIVE TORQUES ALIGNMENT IN THE PRESENCE OF PINWHEEL TORQUES  

SciTech Connect

We study the alignment of grains subject to both radiative torques and pinwheel torques while accounting for thermal flipping of grains. By pinwheel torques we refer to all systematic torques that are fixed in grain body axes, including the radiative torques arising from scattering and absorption of isotropic radiation. We discuss new types of pinwheel torques, which are systematic torques arising from infrared emission and torques arising from the interaction of grains with ions and electrons in hot plasma. We show that both types of torques are long-lived, i.e., may exist longer than gaseous damping time. We compare these torques with the torques introduced by E. Purcell, namely, torques due to H{sub 2} formation, the variation of accommodation coefficient for gaseous collisions and photoelectric emission. Furthermore, we revise the Lazarian and Draine model for grain thermal flipping. We calculate mean flipping timescale induced by Barnett and nuclear relaxation for both paramagnetic and superparamagnetic grains, in the presence of stochastic torques associated with pinwheel torques, e.g., the stochastic torques arising from H{sub 2} formation, and gas bombardment. We show that the combined effect of internal relaxation and stochastic torques can result in fast flipping for sufficiently small grains and, because of this, they get thermally trapped, i.e., rotate thermally in spite of the presence of pinwheel torques. For sufficiently large grains, we show that the pinwheel torques can increase the degree of grain alignment achievable with the radiative torques by increasing the magnitude of the angular momentum of low attractor points and/or by driving grains to new high attractor points.

Hoang, Thiem; Lazarian, A. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)], E-mail: hoang@astro.wisc.edu, E-mail: lazarian@astro.wisc.edu

2009-04-20

30

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Emission Limits for Tire Production Affected Sources 1 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Production Affected Sources As...

2010-07-01

31

40 CFR 63.5984 - What emission limits must I meet for tire production affected sources?  

Code of Federal Regulations, 2010 CFR

... true What emission limits must I meet for tire production affected sources? 63.5984 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984...

2010-07-01

32

Detection of a porcine boca-like virus in combination with porcine circovirus type 2 genotypes and Torque teno sus virus in pigs from postweaning multisystemic wasting syndrome (PMWS)-affected and non-PMWS-affected farms in archival samples from Great Britain.  

PubMed

In this study we detail the detection and genetic analysis of a novel porcine boca-like virus (PBo-likeV) in archival sera and tissue samples from pigs from farms in Great Britain. We also investigate the distribution of porcine circovirus type 2 (PCV2) genotypes and Torque teno sus virus (TTSuV) genogroups 1 and 2 in combination with this novel PBo-likeV. PBo-likeV was detected in over 70% of all tissues investigated. Over 24% of all tissues recovered from PMWS-affected animals had all viruses present and 25% of tissues recovered from non-PMWS-affected pigs were positive for all 4 viruses. PMID:23578709

McMenamy, Michael J; McKillen, John; McNair, Irene; Duffy, Catherine; Blomström, Anne-Lie; Charreyre, Catherine; Welsh, Michael; Allan, Gordon

2013-06-28

33

What Is Torque?  

NSDL National Science Digital Library

This interactive presentation, created by Terry Bartelt for the Electromechanical Digital Library, discusses the concept: "What is torque?" Bartelt begins with a simple example of torque, illustrated using a crank, pail, and water well. After this important introduction, the author introduces the student to the mathematics behind torque. Four different scenarios are used to help students walk through the calculations. Bartelt explains each using helpful interactive flash animations. These are not only useful in the explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction into both the physical and mathematical concept of force. The author concludes the presentation with a brief series of questions.

Bartelt, Terry L. M.

34

Ironless armature torque motor  

NASA Technical Reports Server (NTRS)

Four iron-less armature torque motors, four Hall device position sensor assemblies, and two test fixtures were fabricated. The design approach utilized samarium cobalt permanent magnets, a large airgap, and a three-phase winding in a stationary ironless armature. Hall devices were employed to sense rotor position. An ironless armature torque motor having an outer diameter of 4.25 inches was developed to produce a torque constant of 65 ounce-inches per ampere with a resistance of 20.5 ohms. The total weight, including structural elements, was 1.58 pounds. Test results indicated that all specifications were met except for generated voltage waveform. It is recommended that investigations be made concerning the generated voltage waveform to determine if it may be improved.

Fisher, R. L.

1972-01-01

35

Variable Torque Prescription: State of Art.  

PubMed Central

The variable prescription is widely described under the clinical aspect: the clinics is the result of the evolution of the state-of-the-art, aspect that is less considered in the daily literature. The state-of-the-art is the key to understand not only how we reach where we are but also to learn how to manage propely the torque, focusing on the technical and biomechanical purpos-es that led to the change of the torque values over time. The aim of this study is to update the clinicians on the aspects that affect the torque under the biomechanical sight, helping them to understand how to managing it, following the “timeline changes” in the different techniques so that the Variable Prescription Orthodontic (VPO) would be a suitable tool in every clinical case. PMID:25674173

Lacarbonara, Mariano; Accivile, Ettore; Abed, Maria R; Teresa, Dinoi M; Monaco, Annalisa; Marzo, Giuseppe; Capogreco, Mario

2015-01-01

36

Torque equilibrium attitudes for the Space Station  

NASA Technical Reports Server (NTRS)

All spacecraft orbiting in a low earth orbit (LEO) experience external torques due to environmental effects. Examples of these torques include those induced by aerodynamic, gravity-gradient, and solar forces. It is the gravity-gradient and aerodynamic torques that produce the greatest disturbances to the attitude of a spacecraft in LEO, and large asymmetric spacecraft, such as the space station, are affected to a greater degree because the magnitude of the torques will, in general, be larger in proportion to the moments of inertia. If left unchecked, these torques would cause the attitude of the space station to oscillate in a complex manner and the resulting motion would destroy the micro-gravity environment as well as prohibit the orbiter from docking. The application of control torques will maintain the proper attitude, but the controllers have limited momentum capacity. When any controller reaches its limit, propellant must then be used while the device is reset to a zero or negatively-biased momentum state. Consequently, the rate at which momentum is accumulated is a significant factor in the amount of propellant used and the frequency of resupply necessary to operate the station. A torque profile in which the area curve for a positive torque is not equal to the area under the curve for a negative torque is 'biased,' and the consequent momentum build-up about that axis is defined as secular momentum because it continues to grow with time. Conversely, when the areas are equal, the momentum is cyclic and bounded. A Torque Equilibrium Attitude (TEA) is thus defined as an attitude at which the external torques 'balance' each other as much as possible, and which will result in lower momentum growth in the controllers. Ideally, the positive and negative external moments experienced by a spacecraft at the TEA would exactly cancel each other out and small cyclic control torques would be required only for precise attitude control. Over time, the only momentum build-up in the controllers would be due to electro-mechanical losses within the device. However, the atmospheric torques are proportional to the density of the atmosphere and the density varies with the orbital position, time of day, time of year, and the solar cycle. In addition, there are unmodeled disturbances and uncertainties in the mass and inertias. Therefore, there is no constant attitude that will completely balance the environmental torques and the dynamic TEA cannot be solved in closed form. The objective of this research was to determine a method to calculate a dynamic TEA such that the rate of momentum build-up in the controllers would be minimized and to implement this method in the MATRIX(x) simulation software by Integrated Systems, Inc.

Thompson, Roger C.

1993-01-01

37

Electrostatic Patch Effect in Cylindrical Geometry. III. Torques  

E-print Network

We continue to study the effect of uneven voltage distribution on two close cylindrical conductors with parallel axes started in our papers [1] and [2], now to find the electrostatic torques. We calculate the electrostatic potential and energy to lowest order in the gap to cylinder radius ratio for an arbitrary relative rotation of the cylinders about their symmetry axis. By energy conservation, the axial torque, independent of the uniform voltage difference, is found as a derivative of the energy in the rotation angle. We also derive both the axial and slanting torques by the surface integration method: the torque vector is the integral over the cylinder surface of the cross product of the electrostatic force on a surface element and its position vector. The slanting torque consists of two parts: one coming from the interaction between the patch and the uniform voltages, and the other due to the patch interaction. General properties of the torques are described. A convenient model of a localized patch suggested in [2] is used to calculate the torques explicitly in terms of elementary functions. Based on this, we analyze in detail patch interaction for one pair of patches, namely, the torque dependence on the patch parameters (width and strength) and their mutual positions. The effect of the axial torque is then studied for the experimental conditions of the STEP mission.

Valerio Ferroni; Alexander Silbergleit

2010-09-16

38

Neither Helix in the Coiled Coil Region of the Axle of F1-ATPase Plays a Significant Role in Torque Production  

PubMed Central

F1-ATPase is an ATP-driven rotary molecular motor in which the central ?-subunit rotates inside the cylinder made of ?3?3 subunits. The amino and carboxy termini of the ?-subunit form the axle, an ?-helical coiled coil that deeply penetrates the stator cylinder. We previously truncated the axle step by step, starting with the longer carboxy terminus and then cutting both termini at the same levels, resulting in a slower yet considerably powerful rotation. Here we examine the role of each helix by truncating only the carboxy terminus by 25–40 amino-acid residues. Longer truncation impaired the stability of the motor complex severely: 40 deletions failed to yield rotating the complex. Up to 36 deletions, however, the mutants produced an apparent torque at nearly half of the wild-type torque, independent of truncation length. Time-averaged rotary speeds were low because of load-dependent stumbling at 120° intervals, even with saturating ATP. Comparison with our previous work indicates that half the normal torque is produced at the orifice of the stator. The very tip of the carboxy terminus adds the other half, whereas neither helix in the middle of the axle contributes much to torque generation and the rapid progress of catalysis. None of the residues of the entire axle played a specific decisive role in rotation. PMID:18708468

Hossain, Mohammad Delawar; Furuike, Shou; Maki, Yasushi; Adachi, Kengo; Suzuki, Toshiharu; Kohori, Ayako; Itoh, Hiroyasu; Yoshida, Masasuke; Kinosita, Kazuhiko

2008-01-01

39

Knowledge of Repetitions Range Affects Force Production in Trained Females  

PubMed Central

Most studies have examined pacing strategies with cyclical activities (running and cycling). It has been demonstrated that males employ different pacing strategies during repeated maximal voluntary contractions (MVCs) dependent upon a known endpoint. Since different fatiguing mechanisms have been identified between the genders, it is not known if females use comparable pacing strategies. The purpose of this study was to examine if informing female subjects regarding the number of MVCs to perform would affect force and electromyography (EMG). Twenty well-trained females completed 3 fatiguing protocols in a randomized order. In the control condition participants were informed they would perform twelve MVCs and then actually completed twelve. In the unknown condition they were not told how many MVCs to perform but were stopped after twelve. In the deception condition they were initially informed to perform 6 MVCs, but after the 6th MVC they were asked to perform a few more MVCs and were stopped after twelve. During the first 6 MVCs, forces in the deception condition were greater compared to the unknown (p = 0.021, ES = 0.65, 5%) and control (p = 0.022, ES = 0.42, 3%) conditions. No differences were found between conditions in the last 6 MVCs. A main effect for repetitions showed force deficits during the first 6 MVCs (p = 0.000, ES = 1.81, 13%) and last 6 MVCs (p = 0.05, ES = 0.34, 3%). No differences were found between conditions in biceps and triceps EMG. However, EMG decreased during the first 6 MVCs for biceps (p = 0.001, ES = 1.0, 14%) and triceps (p = 0.001, ES = 0.76, 14%) across conditions. No differences were found in the last 6 MVCs. The anticipation of performing fewer MVCs led to increased force, whereas no endpoint led to decreased force production. Key points Pacing strategies occur during repeated (fatiguing) MVCs as a function of end point expectations. Females use similar pacing strategies as previously published results with males. Without a known end point, females will tend to pace themselves by decreasing force output even when asked to perform maximal contractions. PMID:25435764

Halperin, Israel; Aboodarda, Saied J.; Basset, Fabien A.; Behm, David G.

2014-01-01

40

Special-Purpose High-Torque Permanent-Magnet Motors  

NASA Technical Reports Server (NTRS)

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

Doane, George B., III

1995-01-01

41

40 CFR Table 3 to Subpart Nnnnn of... - Performance Test Requirements for HCl Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Performance Test Requirements for HCl Production Affected Sources 3 Table 3 to Subpart NNNNN of Part 63 Protection of Environment...Hydrochloric Acid Production Pt. 63, Subpt. NNNNN, Table 3 Table 3 to Subpart NNNNN of Part 63—Performance...

2010-07-01

42

Light and Temperature: Key Factors Affecting Walleye Abundance and Production  

Microsoft Academic Search

We used published information to determine optimum light and temperature conditions for walleye Sander vitreus (formerly Stizostedion vitreum) and then applied this simple niche definition to predict how water clarity, temperature, and bathymetry affect walleye habitat availability. Our model calculated thermal–optical habitat area (TOHA), the benthic area of a lake that supplies optimum light, and temperature conditions for walleye during

Nigel P. Lester; Alan J. Dextrase; Robert S. Kushneriuk; Michael R. Rawson; Phil A. Ryan

2004-01-01

43

Transpiration affects soil CO2 production in a dry grassland  

NASA Astrophysics Data System (ADS)

Although soil CO2 efflux can be highly variable on the diel time scale, it is often measured during daytime only. However, to get a full understanding of soil CO2 efflux and its impact on carbon cycle processes, looking at diurnal processes is crucial. Therefore, our aim was to investigate how diel variation in soil CO2 efflux from a dry, sandy grassland in Hungary depends on variations in potential drivers, such as gross primary production (GPP) and evapotranspiration (ET). In order to reach this goal, we combined measurements of CO2 and H2O fluxes by eddy covariance, soil chambers and soil CO2 gradient system. Surface CO2 fluxes were partitioned into the three CO2 production components originating from the three soil layers to clarify the timing and the source of the CO2 within the top 50 cm of the soil. CO2 production rates during the growing season were higher during nighttime than during daytime. This diel course was not only driven by soil temperature and soil moisture, but also by ET. This was shown by changes of ET causing a hysteresis loop in the diel response of CO2 production to soil temperature. CO2 production was coupled to soil temperature at night and during midday (12-14 h), when ET remained relatively constant. However, when ET was changing over time, CO2 production was decoupled from soil temperature. In order to disentangle these effects, we carried out time-lag analyses between CO2 production and efflux residuals after having subtracted the main effects of soil temperature and soil water content from measured CO2 fluxes. The results showed a strong negative correlation between ET rates and residuals of soil CO2 production, and a less strong, but still significantly time-lagged positive correlation between GPP and residuals of soil CO2 production. Thus, we could show that there is a rapid negative response of soil CO2 production rates to transpiration (suggesting CO2 transport in the xylem stream) and a delayed positive response to GPP, indicating the importance of newly synthesized non-structural carbohydrates for soil respiration. We conclude that the instant effect of soil temperature and transpiration in combination with the time-lagged effect of GPP governed the diel changes in soil CO2 production at our site. If measurements are carried out at night or during daytime only, then this can lead to considerable misinterpretations of CO2 production rates. Hence we recommend that estimates of respiration rates at a specific site should include both nocturnal and daytime processes.

Balogh, János; Fóti, Szilvia; Pintér, Krisztina; Burri, Susanne; Eugster, Werner; Papp, Marianna; Nagy, Zoltán

2014-05-01

44

Statistical frequency in perception affects children's lexical production.  

PubMed

Children's early word production is influenced by the statistical frequency of speech sounds and combinations. Three experiments asked whether this production effect can be explained by a perceptual learning mechanism that is sensitive to word-token frequency and/or variability. Four-year-olds were exposed to nonwords that were either frequent (presented 10 times) or infrequent (presented once). When the frequent nonwords were spoken by the same talker, children showed no significant effect of perceptual frequency on production. When the frequent nonwords were spoken by different talkers, children produced them with fewer errors and shorter latencies. The results implicate token variability in perceptual learning. PMID:19338981

Richtsmeier, Peter T; Gerken, LouAnn; Goffman, Lisa; Hogan, Tiffany

2009-06-01

45

FACTORS AFFECTING THE PHOTOCHEMICAL PRODUCTION OF CARBONYL SULFIDE IN SEAWATER  

EPA Science Inventory

Our laboratory studies indicate that the photochemical production of carbonyl sulfide (COS) in seawater can result from the photosensitized reaction of organosulfur compounds. Because natural photosensitizers are more prevalent in coastal waters than the open ocean, these results...

46

Factors affecting quality of fresh-cut horticultural products  

Microsoft Academic Search

Fresh-cut products, also known as lightly or minimally processed products, are highly perishable because a large proportion of their surface area is without epidermis, the outer protective layer of tissue. Temperature, atmosphere, relative humidity and sanitation must be regulated to maintain quality of fresh-cuts. In the 0–10 °C range, Q10 of respiration rates ranged from 2.0 to 8.6 among various

Alley E. Watada; Nathanee P. Ko; Donna A. Minott

1996-01-01

47

Some factors affecting tannase production by Aspergillus niger Van Tieghem  

PubMed Central

One variable at a time procedure was used to evaluate the effect of qualitative variables on the production of tannase from Aspergillus niger Van Tieghem. These variables including: fermentation technique, agitation condition, tannins source, adding carbohydrates incorporation with tannic acid, nitrogen source type and divalent cations. Submerged fermentation under intermittent shaking gave the highest total tannase activity. Maximum extracellular tannase activity (305 units/50 mL) was attained in medium containing tannic acid as tannins source and sodium nitrate as nitrogen source at 30 °C for 96 h. All added carbohydrates showed significant adverse effects on the production of tannase. All tested divalent cations significantly decreased tannase production. Moreover, split plot design was carried out to study the effect of fermentation temperature and fermentation time on tannase production. The results indicated maximum tannase production (312.7 units/50 mL) at 35 °C for 96 h. In other words, increasing fermentation temperature from 30 °C to 35 °C resulted in increasing tannase production. PMID:24294255

Aboubakr, Hamada A.; El-Sahn, Malak A.; El-Banna, Amr A.

2013-01-01

48

Factors affecting the fermentative lactic acid production from renewable resources 1  

Microsoft Academic Search

Parameters affecting the fermentative lactic acid (LA) production are summarized and discussed: microorganism, carbon- and nitrogen-source, fermentation mode, pH, and temperature. LA production is compared in terms of LA concentration, LA yield and LA productivity. Also by-product formation and LA isomery are discussed.

Karin Hofvendahl

2000-01-01

49

Variability in population and community biomass in a grassland community affected by environmental productivity and diversity  

E-print Network

productivity and diversity Jan Leps Leps, J. 2004. Variability in population and community biomass in a grassland community affected by environmental productivity and diversity. Á/ Oikos 107: 64Á/71. TemporalVariability in population and community biomass in a grassland community affected by environmental

Leps, Jan "Suspa"

50

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Limits for Tire Cord Production Affected Sources 2 Table 2 to Subpart XXXX of Part...STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards...Limits for Tire Cord Production Affected Sources As stated in § 63.5986, you...

2010-07-01

51

Temperature can interact with landscape factors to affect songbird productivity.  

PubMed

Increased temperatures and more extreme weather patterns associated with global climate change can interact with other factors that regulate animal populations, but many climate change studies do not incorporate other threats to wildlife in their analyses. We used 20 years of nest-monitoring data from study sites across a gradient of habitat fragmentation in Missouri, USA, to investigate the relative influence of weather variables (temperature and precipitation) and landscape factors (forest cover and edge density) on the number of young produced per nest attempt (i.e., productivity) for three species of songbirds. We detected a strong forest cover × temperature interaction for the Acadian Flycatcher (Empidonax virescens) on productivity. Greater forest cover resulted in greater productivity because of reduced brood parasitism and increased nest survival, whereas greater temperatures reduced productivity in highly forested landscapes because of increased nest predation but had no effect in less forested landscapes. The Indigo Bunting (Passerina cyanea) exhibited a similar pattern, albeit with a marginal forest cover × temperature interaction. By contrast, productivity of the Northern Cardinal (Cardinalis cardinalis) was not influenced by landscape effects or temperature. Our results highlight a potential difficulty of managing wildlife in response to global change such as habitat fragmentation and climate warming, as the habitat associated with the greatest productivity for flycatchers was also that most negatively influenced by high temperatures. The influence of high temperatures on nest predation (and therefore, nest predators) underscores the need to acknowledge the potential complexity of species' responses to climate change by incorporating a more thorough consideration of community ecology in the development of models of climate impacts on wildlife. PMID:23504884

Cox, W Andrew; Thompson, Frank R; Reidy, Jennifer L; Faaborg, John

2013-04-01

52

Spin torque transistor revisited  

NASA Astrophysics Data System (ADS)

We theoretically study the operation of a 4-terminal device consisting of two lateral thin-film spin valves that are coupled by a magnetic insulator such as yttrium iron garnet via the spin transfer torque. By magnetoelectronic circuit theory we calculate the current voltage characteristics and find negative differential resistance and differential gain in a large region of parameter space. We demonstrate that functionality is preserved when the control spin valve is replaced by a normal metal film with a large spin Hall angle.

Chiba, Takahiro; Bauer, Gerrit E. W.; Takahashi, Saburo

2013-05-01

53

Bacterial Community Affects Toxin Production by Gymnodinium catenatum  

PubMed Central

The paralytic shellfish toxin (PST)-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01) and grown with: 1) complex bacterial communities derived from each of the two parent cultures; 2) simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3) a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell) of clonal offspring (134–197 fmol STX cell?1) was similar to the parent cultures (169–206 fmol STX cell?1), however cultures grown with single bacterial types contained less toxin (134–146 fmol STX cell?1) than offspring or parent cultures grown with more complex mixed bacterial communities (152–176 fmol STX cell?1). Specific toxin production rate (fmol STX day?1) was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell?1 day?1) did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX production of dinoflagellates. In G. catenatum the mechanism appears likely to be due to bacterial effects on dinoflagellate physiology rather than bacterial biotransformation of PST toxins. PMID:25117053

Albinsson, Maria E.; Negri, Andrew P.; Blackburn, Susan I.; Bolch, Christopher J. S.

2014-01-01

54

Torque control for electric motors  

NASA Technical Reports Server (NTRS)

Method for adjusting electric-motor torque output to accomodate various loads utilizes phase-lock loop to control relay connected to starting circuit. As load is imposed, motor slows down, and phase lock is lost. Phase-lock signal triggers relay to power starting coil and generate additional torque. Once phase lock is recoverd, relay restores starting circuit to its normal operating mode.

Bernard, C. A.

1980-01-01

55

Momentum Confinement at Low Torque  

SciTech Connect

Momentum confinement was investigated on DIII-D as a function of applied neutral beam torque at constant normalized {beta}{sub N}, by varying the mix of co (parallel to the plasma current) and counter neutral beams. Under balanced neutral beam injection (i.e. zero total torque to the plasma), the plasma maintains a significant rotation in the co-direction. This 'intrinsic' rotation can be modeled as being due to an offset in the applied torque (i.e. an 'anomalous torque'). This anomalous torque appears to have a magnitude comparable to one co-neutral beam source. The presence of such an anomalous torque source must be taken into account to obtain meaningful quantities describing momentum transport, such as the global momentum confinement time and local diffusivities. Studies of the mechanical angular momentum in ELMing H-mode plasmas with elevated q{sub min} show that the momentum confinement time improves as the torque is reduced. In hybrid plasmas, the opposite effect is observed, namely that momentum confinement improves at high torque/rotation. The relative importance of E x B shearing between the two is modeled using GLF23 and may suggest a possible explanation.

Solomon, W M; Burrell, K H; deGrassie, J S; Budny, R; Groebner, R J; Heidbrink, W W; Kinsey, J E; Kramer, G J; Makowski, M A; Mikkelsen, D; Nazikian, R; Petty, C C; Politzer, P A; Scott, S D; Van Zeeland, M A; Zarnstorff, M C

2007-06-26

56

Thermal Spin Transfer Torques  

NASA Astrophysics Data System (ADS)

The coupling between spin and charge in electronic transport is studied in the field of spintronics. Heat currents are coupled to both charge and spin currents as well [1]. This extension of spintronics to what may be called ``spin caloritronics'' recently enjoys renewed attention [2]. The spin-transfer torque associated with electric currents can excite magnetizations in nanostructures, switching magnetic configuration in spin valves and move domain walls in magnetic wires when exceeding critical values of the order of 10^7Acm-2 [3]. Also heat currents transfer spin angular momentum [4], either intrinsically or via the thermoelectric generation of particle spin currents. We predict that temperature differences of the order of 100 K over typical metallic nanostructures cause effects equivalent to the critical charge current densities. In this talk I will give a brief review of various aspects of spin caloritronics with emphasis on thermal spin transfer torques. This work has been carried out in collaboration with Moosa Hatami, Qinfang Zhang, Paul Kelly, Hans Joakim Skadsem, Arne Brataas and Sadamichi Maekawa. [4pt] [1] M. Johnson and R.H. Silsbee, Phys. Rev. B 35, 4959 (1987).[0pt] [2] International Workshop on Spin Caloritronics, Lorentz Center of Leiden University, 9-13 February 2009, http://www.lorentzcenter.nl/lc/web/2009/323/info.php3?wsid=323[0pt] [3] D. C. Ralph and M. D. Stiles, J. Magn. Magn. Mater. 320, 1190 (2008).[0pt] [4] M. Hatami, G.E.W. Bauer, Q. Zhang, and P.J. Kelly, Phys. Rev. Lett. 99, 066603 (2007).

Bauer, Gerrit

2009-03-01

57

Resource limitation affects productivity and heterocyst formation in nitrogen-fixing cyanobacteria  

E-print Network

Resource limitation affects productivity and heterocyst formation in nitrogen-fixing cyanobacteria optimization, substitutable resource, cyanobacteria, heterocyst, Anabaena, Abstract Cyanobacteria of substitutable resource optimization. These cyanobacteria can acquire nitrogen through fixation or assimilation

Vallino, Joseph J.

58

The effect of affect in advertising: can product preference be conditioned by background music?   

E-print Network

The present experiment provides a recent replication of Gorn’ (1982) affective conditioning study, investigating the role of music-induced mood in advertising and its subsequent effect on product choice. As an extension ...

Stone, Katrina

2007-01-01

59

Trophoblast Production of a Weakly Bioactive Human Chorionic Gonadotropin in Trisomy 21-Affected Pregnancy  

E-print Network

in maternal serum at 14-18 weeks of trisomy 21 (T21)-affected pregnancy, despite low placental hCG synthesis1 Trophoblast Production of a Weakly Bioactive Human Chorionic Gonadotropin in Trisomy 21-Affected-00128419,version1 #12;3 INTRODUCTION Trisomy of chromosome 21 (T21), which causes the phenotype known

Paris-Sud XI, Université de

60

Space Suit Joint Torque Measurement Method Validation  

NASA Technical Reports Server (NTRS)

In 2009 and early 2010, a test method was developed and performed to quantify the torque required to manipulate joints in several existing operational and prototype space suits. This was done in an effort to develop joint torque requirements appropriate for a new Constellation Program space suit system. The same test method was levied on the Constellation space suit contractors to verify that their suit design met the requirements. However, because the original test was set up and conducted by a single test operator there was some question as to whether this method was repeatable enough to be considered a standard verification method for Constellation or other future development programs. In order to validate the method itself, a representative subset of the previous test was repeated, using the same information that would be available to space suit contractors, but set up and conducted by someone not familiar with the previous test. The resultant data was compared using graphical and statistical analysis; the results indicated a significant variance in values reported for a subset of the re-tested joints. Potential variables that could have affected the data were identified and a third round of testing was conducted in an attempt to eliminate and/or quantify the effects of these variables. The results of the third test effort will be used to determine whether or not the proposed joint torque methodology can be applied to future space suit development contracts.

Valish, Dana; Eversley, Karina

2012-01-01

61

Heat Control via Torque Control in Friction Stir Welding  

NASA Technical Reports Server (NTRS)

In a proposed advance in friction stir welding, the torque exerted on the workpiece by the friction stir pin would be measured and controlled in an effort to measure and control the total heat input to the workpiece. The total heat input to the workpiece is an important parameter of any welding process (fusion or friction stir welding). In fusion welding, measurement and control of heat input is a difficult problem. However, in friction stir welding, the basic principle of operation affords the potential of a straightforward solution: Neglecting thermal losses through the pin and the spindle that supports it, the rate of heat input to the workpiece is the product of the torque and the speed of rotation of the friction stir weld pin and, hence, of the spindle. Therefore, if one acquires and suitably processes data on torque and rotation and controls the torque, the rotation, or both, one should be able to control the heat input into the workpiece. In conventional practice in friction stir welding, one uses feedback control of the spindle motor to maintain a constant speed of rotation. According to the proposal, one would not maintain a constant speed of rotation: Instead, one would use feedback control to maintain a constant torque and would measure the speed of rotation while allowing it to vary. The torque exerted on the workpiece would be estimated as the product of (1) the torque-multiplication ratio of the spindle belt and/or gear drive, (2) the force measured by a load cell mechanically coupled to the spindle motor, and (3) the moment arm of the load cell. Hence, the output of the load cell would be used as a feedback signal for controlling the torque (see figure).

Venable, Richard; Colligan, Kevin; Knapp, Alan

2004-01-01

62

40 CFR 63.5996 - How do I demonstrate initial compliance with the emission limits for tire production affected...  

Code of Federal Regulations, 2010 CFR

...compliance with the emission limits for tire production affected sources? 63.5996...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Testing and Initial Compliance Requirements for Tire Production Affected Sources §...

2010-07-01

63

40 CFR 63.5987 - What are my alternatives for meeting the emission limits for tire cord production affected sources?  

Code of Federal Regulations, 2010 CFR

...alternatives for meeting the emission limits for tire cord production affected sources? 63.5987...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Cord Production Affected Sources §...

2010-07-01

64

40 CFR 63.5986 - What emission limits must I meet for tire cord production affected sources?  

Code of Federal Regulations, 2010 CFR

... true What emission limits must I meet for tire cord production affected sources? 63.5986...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Cord Production Affected Sources §...

2010-07-01

65

40 CFR Table 7 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Compliance With the Emission Limits for Tire Cord Production Affected Sources 7 ...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...Compliance With the Emission Limits for Tire Cord Production Affected Sources...

2010-07-01

66

40 CFR 63.5985 - What are my alternatives for meeting the emission limits for tire production affected sources?  

Code of Federal Regulations, 2010 CFR

...alternatives for meeting the emission limits for tire production affected sources? 63.5985 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5985...

2010-07-01

67

40 CFR Table 12 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Compliance With the Emission Limits for Tire Cord Production Affected Sources 12...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...Compliance With the Emission Limits for Tire Cord Production Affected Sources...

2010-07-01

68

40 CFR 63.6004 - How do I demonstrate continuous compliance with the emission limits for tire production affected...  

Code of Federal Regulations, 2010 CFR

...emission limits for tire production affected sources? 63.6004 Section 63.6004 Protection...STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards...Requirements for Tire Production Affected Sources § 63.6004 How do I...

2010-07-01

69

RICE PRODUCTION SYSTEM AND STUDY METHODOLOGY AFFECT RICE IRRIGATION-WATER USE ESTIMATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice irrigation-water use was estimated in Mississippi (MS) and Arkansas (AR) in 2003 and 2004. Irrigation inputs were compared on naturally sloping and precision-graded fields. In MS, rice production consumed, on average, 895 mm water, but irrigation inputs were greatly affected by production syste...

70

FACTORS AFFECTING THE FORMATION OF ORGANIC BY-PRODUCTS DURING WATER CHLORINATION  

E-print Network

FACTORS AFFECTING THE FORMATION OF ORGANIC BY-PRODUCTS DURING WATER CHLORINATION: A BENCH 2004) Abstract. The formation of chlorination by-products (CBPs) was investigated through bench-scale chlorination experiments with river water. The compounds selected for analysis belonged to the groups

Arhonditsis, George B.

71

Pressurized fluid torque driver control and method  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

Cook, Joseph S., Jr. (inventor)

1994-01-01

72

Split torque transmission load sharing  

NASA Technical Reports Server (NTRS)

Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears.

Krantz, T. L.; Rashidi, M.; Kish, J. G.

1992-01-01

73

Split torque transmission load sharing  

SciTech Connect

Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears.

Krantz, T.L.; Rashidi, M.; Kish, J.G.

1992-10-01

74

Production of cercosporin toxin by the phytopathogenic Cercospora fungi is affected by diverse environmental signals.  

PubMed

Cercosporin is a polyketide phytotoxin produced by many phytopathogenic Cercospora spp. We investigated environmental signals that have elaborate control of cercosporin production. Light is the most critical factor for cercosporin production. Cercospora nicotianae accumulated substantial quantities of cercosporin only when grown on a particular potato dextrose agar under light but produced little cercosporin on other brands of potato dextrose agar or media with defined ingredients. In addition to light regulation, numerous factors including salts, buffers, and ions markedly affected cercosporin production. By contrast, pH had little effect on cercosporin production. Depletion or alteration of the carbon or nitrogen sources also affected cercosporin production. Production of cercosporin was elevated to varying levels by metal ions, such as cobalt, ferric, manganese, and zinc. Significant differences in cercosporin production were observed among various Cercospora species. Further, regulation of cercosporin production by phosphate buffer, ammonium, LiCl, but not metal ions appeared to occur at transcriptional levels. Expression of the genes involved in cercosporin biosynthesis and regulation decreased markedly and was closely concomitant with the amounts of cercosporin reduced as the fungus was grown on medium containing phosphate, LiCl, ammonium, or dimethyl sulfoxide. The results reveal the complexity of cercosporin production at the physiological and genetic levels. A model delineating regulatory controls of cercosporin biosynthesis is proposed and discussed. PMID:18388998

You, Bang-Jau; Lee, Miin-Hui; Chung, Kuang-Ren

2008-04-01

75

Coupling between switching regulation and torque generation in bacterial flagellar motor  

E-print Network

The bacterial flagellar motor plays a crucial role in both bacterial locomotion and chemotaxis. Recent experiments reveal that the switching dynamics of the motor depends on the motor rotation speed, and thus the motor torque, non-monotonically. Here we present a unified mathematical model which models motor torque generation based on experimental torque-speed curves and torque-dependent switching based on the conformational spread model. The model successfully reproduces the observed switching rate as a function of the rotation speed, and provides a generic physical explanation independent of most details. A stator affects the switching dynamics through two mechanisms: accelerating the conformation flipping rates of individual rotor switching units, which favours slower motor speed and thus increasing torque; and affecting more switching units within unit time, which favours faster speed. Consequently, the switching rate shows a maximum at intermediate speed. Our model predicts that a motor switches more oft...

Bai, Fan; Wu, Zhanghan; Namba, Keiichi; Xing, Jianhua

2012-01-01

76

DTC Based Induction Motor Speed Control Using 10-Sector Methodology for Torque Ripple Reduction  

NASA Astrophysics Data System (ADS)

A direct torque control (DTC) drive allows direct and independent control of flux linkage and electromagnetic torque by the selection of optimum inverter switching modes. It is a simple method of signal processing which gives excellent dynamic performance. Also transformation of coordinates and voltage decoupling are not required. However, the possible discrete inverter switching vectors cannot always generate exact stator voltage required, to obtain the demanded electromagnetic torque and flux linkages. This results in the production of ripples in the torque as well as flux waveforms. In the present paper a torque ripple reduction methodology is proposed. In this method the circular locus of flux phasor is divided into 10 sector as compared to six sector divisions in conventional DTC method. The basic DTC scheme and the 10-sector method are simulated and compared for their performance. An analysis is done with sector increment so that finally the torque ripple varies slightly as the sector is increased.

Pavithra, S.; Dinesh Krishna, A. S.; Shridharan, S.

2014-09-01

77

Production of arabitol from glycerol: strain screening and study of factors affecting production yield  

Technology Transfer Automated Retrieval System (TEKTRAN)

Glycerol is a major byproduct from biodiesel production, and developing new uses for glycerol is imperative to overall economics and sustainability of the biodiesel industry. With the aim of producing xylitol and/or arabitol as the value-added products from glycerol, 214 yeast strains, many osmotole...

78

Demographic and Academic Factors Affecting Research Productivity at the University of KwaZulu-Natal  

ERIC Educational Resources Information Center

Research output affects both the strength and funding of universities. Accordingly university academic staff members are under pressure to be active and productive in research. Though all academics have research interest, all are not producing research output which is accredited by the Department of Education (DOE). We analyzed the demographic and…

North, D.; Zewotir, T.; Murray, M.

2011-01-01

79

EFFECT OF GENES AFFECTING TAN COLOUR ON PRODUCTIVITY IN ICELANDIC SHEEP  

E-print Network

EFFECT OF GENES AFFECTING TAN COLOUR ON PRODUCTIVITY IN ICELANDIC SHEEP S. ADALSTEINSSON of the effect, within the Icelandic Sheep breed, of pelt class of sire and pelt class of daughter on lambing The research work to be described here has been aimed at improving the Icelandic sheep breed with respect

Paris-Sud XI, Université de

80

ALOX5 gene variants affect eicosanoid production and response to fish oil supplementation  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study was to determine whether 5-lipoxygenase (ALOX5) gene variants associated with cardiovascular disease affect eicosanoid production by monocytes. The study was a randomized, double-masked, parallel intervention trial with fish oil (5.0 g of fish oil daily, containing 2.0 g ...

81

Factors Affecting the Functional Properties of Whey Protein Products: A Review  

Microsoft Academic Search

Numerous why protein products (WPP) have been developed as excellent food ingredients with unique functional properties. However, the functional properties of WPP are affected by several compositional and processing factors. Recently, novel processing technologies such as high hydrostatic pressure, ultrasound, extrusion and tribomechanical activation have been used to modify the functional properties of WPP. Also, WPP have been used as

M. H. Abd El-Salam; Safinaz El-Shibiny; Aida Salem

2009-01-01

82

A MULTI-YEAR STUDY OF FACTORS AFFECTING FRUIT PRODUCTION IN ARISTOLOCHIA PAUCINERVIS  

E-print Network

A MULTI-YEAR STUDY OF FACTORS AFFECTING FRUIT PRODUCTION IN ARISTOLOCHIA PAUCINERVIS limitation, resource limitation, fruit abortion, and predation have all been proposed as factors explaining low fruit set in hermaphroditic plants. We conducted a 5-year study combining field observations

Herrera, Carlos M.

83

The outcome of malemale encounters affects subsequent sound production during courtship in the cichlid  

E-print Network

The outcome of male­male encounters affects subsequent sound production during courtship in the cichlid fish Oreochromis mossambicus M. CLARA P. AMORIM & VITOR C. ALMADA Unidade de Investigac¸a~o em Eco of courtship sounds in male Mozambique tilapia, Oreochromis mossambicus, in the absence of dominant males. We

84

14 CFR 25.361 - Engine torque.  

Code of Federal Regulations, 2010 CFR

...Conditions § 25.361 Engine torque. (a) Each engine mount and its supporting...must be designed for the effects of— (1) A limit engine torque corresponding...For turbopropeller installations, in addition to...

2010-01-01

85

14 CFR 23.361 - Engine torque.  

Code of Federal Regulations, 2010 CFR

...Loads § 23.361 Engine torque. (a) Each engine mount and its supporting...must be designed for the effects of— (1) A limit engine torque corresponding...For turbopropeller installations, in addition to...

2010-01-01

86

MEASUREMENT OF TORQUE IN MICROMOTORS  

Microsoft Academic Search

This paper describes a dynamometer developed for the measurement of torque of micromotors as a f unction of the rotational speed. The operating principle of the device is based on that of a typical viscometer. The shaft of the micromotor to be tested is coupled to a small cylin der, which is placed concentrically into a larger cylind er. The

Jaime I. Hernández-Navarro; Gabriel Ascanio; Leopoldo Ruiz-Huerta; Alberto Caballero-Ruiz

87

Parameters affecting production and character of an extrusion texturized protein product from defatted glandless cottonseed meal  

E-print Network

to calculate Z water regain 25 Typical force vs, deformation curves obtained with the Warner-Bratzler shear cell device 29 Rheological parameters extracted from the force vs. deformation curve 30 The effect of feed rate and oil bath temp- erature... on the product (head No. 8) temp- erature at a constant screw speed of 650 rpm . . 36 The effect of screw speed and oil bath temp- erature on the product (head No, 8) tempera- ture at a constant feed rate of 0, 30 lbs. /min. . 38 The effect of screw speed...

Taranto, Michael Vincent

1974-01-01

88

Purple Nutsedge Tuber Productivity as Affected by Organic Mulches in a Watermelon Production System  

Technology Transfer Automated Retrieval System (TEKTRAN)

Research was conducted in Isabela, Puerto Rico, to determine the tuber productivity of the weed purple nutsedge (PN) and the yield of ‘Crimson Sweet' watermelon when grown with or without organic soil bed mulches [hays of millet (Pennisetum glaucum), nutsedge (Cyperus rotundus), sunnhemp (Crotalaria...

89

Environmental Qualification of an Actuator Torque Switch  

Microsoft Academic Search

Environmental qualification testing was performed on a modified Limitorque torque switch for the torque switch safety functions in the Limitorque type SMB actuators located inside and outside containment in a nuclear power plant. The torque switch specimen was installed in a Limitorque SMB-1 electric actuator mounted on an 8'' Velan gate valve and operated with a customized programmable logic controller

A. M. Chan; S. L. Barreca; T. Kostela

2006-01-01

90

Computerized Torque Control for Large dc Motors  

NASA Technical Reports Server (NTRS)

Speed and torque ranges in generator mode extended. System of shunt resistors, electronic switches, and pulse-width modulation controls torque exerted by large, three-phase, electronically commutated dc motor. Particularly useful for motor operating in generator mode because it extends operating range to low torque and high speed.

Willett, Richard M.; Carroll, Michael J.; Geiger, Ronald V.

1987-01-01

91

Redundancy resolution of manipulators through torque optimization  

Microsoft Academic Search

Methods for resolving kinematic redundancies of manipulators by the effect on joint torque are examined. When the generalized inverse is formulated in terms of accelerations and incorporated into the dynamics, the effect of redundancy resolution on joint torque can be directly reflected. One method chooses the joint acceleration null-space vector to minimize joint torque in a least squares sense; when

John M. Hollerbach; Ki C. Suh

1985-01-01

92

Spin Transfer torques in Antiferromagnets  

NASA Astrophysics Data System (ADS)

Spin Transfer Torque (STT) has attracted tremendously growing interest in the past two decades. Consisting on the transfer of spin angular momentum of a spin polarized current to local magnetic moments, the STT gives rise to a complex dynamics of the magnetization. Depending on the the structure, the STT shows a dominated In plane component for spin valves [1], whereas both components coexist for magnetic tunneling junctions (MTJ) [2]. For latter case the symmetry of the structure is considered to be decisive in identifying the nature and behavior of the torque [3]. In the present study we are interested in magnetic structures where we substitute either one or both of the magnetic layers by antiferromagnets (AF). We use Non-equilibrium Green's function formalism applied on a tight-binding model to investigate the nature of the spin torque. We notice the presence of two types of torque exerted on (AF), a torque which tends to rotate the order parameter and another one that competes with the exchange interaction. We conclude by comparison with previous works [4-5].[4pt] [1] Xia, K., Kelly, P. J., Bauer, G. E. W., Brataas, A. & Turek, Phys. Rev. B 65, 220401 (2002). [2] Sankey, J. C. et al. Nature Phys. 4, 67--71 (2008). [3] A. Kalitsov. et al. and W. H. Butler, Phys. Rev. B 79, 174416 (2009). [4] A. S. N'uñez , R. A. Duine, Paul Haney, and A. H. MacDonald, Phys. Rev. B 73, 214426 (2006). [5] R. A. Duine et al., Phys. Rev. B 75, 014433 (2007).

Saidaoui, Hamed; Waintal, Xavier; Manchon, Aurelien

2013-03-01

93

Herbivore and Fungal Pathogen Exclusion Affects the Seed Production of Four Common Grassland Species  

PubMed Central

Insect herbivores and fungal pathogens can independently affect plant fitness, and may have interactive effects. However, few studies have experimentally quantified the joint effects of insects and fungal pathogens on seed production in non-agricultural populations. We examined the factorial effects of insect herbivore exclusion (via insecticide) and fungal pathogen exclusion (via fungicide) on the population-level seed production of four common graminoid species (Andropogon gerardii, Schizachyrium scoparium, Poa pratensis, and Carex siccata) over two growing seasons in Minnesota, USA. We detected no interactive effects of herbivores and pathogens on seed production. However, the seed production of all four species was affected by either insecticide or fungicide in at least one year of the study. Insecticide consistently doubled the seed production of the historically most common species in the North American tallgrass prairie, A. gerardii (big bluestem). This is the first report of insect removal increasing seed production in this species. Insecticide increased A. gerardii number of seeds per seed head in one year, and mass per seed in both years, suggesting that consumption of flowers and seed embryos contributed to the effect on seed production. One of the primary insect species consuming A. gerardii flowers and seed embryos was likely the Cecidomyiid midge, Contarinia wattsi. Effects on all other plant species varied among years. Herbivores and pathogens likely reduce the dispersal and colonization ability of plants when they reduce seed output. Therefore, impacts on seed production of competitive dominant species may help to explain their relatively poor colonization abilities. Reduced seed output by dominant graminoids may thereby promote coexistence with subdominant species through competition-colonization tradeoffs. PMID:20711408

Dickson, Timothy L.; Mitchell, Charles E.

2010-01-01

94

Polyhydroxyalkanoate synthesis affects biosurfactant production and cell attachment to hydrocarbons in Pseudomonas sp. KA-08.  

PubMed

Stressful conditions prevailing in hydrocarbon-contaminated sites influence the diversity, distribution, and activities of microorganisms. Oil bioremediation agents should develop special characteristics to cope with these environments like surfactant production and cellular affinity to hydrocarbons. Additionally, polyhydroxyalkanoate (PHA) accumulation was proven to improve tolerance to stressful conditions. Pseudomonas sp. KA-08 was isolated from a chronic oil-contaminated environment, it is highly tolerant to xylene, and it is able to accumulate PHA and to produce surfactant compounds that lower the water surface tension (ST) as well as bioemulsifiers. In this work, we studied the effect of the capability to accumulate PHAs on biosurfactant production and microbial attachment to hydrocarbons (MATH). Our results showed that PHA synthesis capability has a favorable effect in the production of compounds which affect the ST but not on the production of bioemulsifiers. On the other hand, PHA accumulation affects cellular affinity to xylene. MATH analysis showed that a PHA-negative mutant increased its affinity to xylene compared with the wild-type strain. This result was also observed in Pseudomonas putida GPp104 (a PHA(-) mutant), suggesting that this effect could be generalized to other Pseudomonas strains. PMID:24519857

Di Martino, Carla; Catone, Mariela V; López, Nancy I; Raiger Iustman, Laura J

2014-06-01

95

40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Emission Limits for Tire Production Affected Sources 10 Table 10 to Subpart XXXX of Part...STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards...Emission Limits for Tire Production Affected Sources As stated in § 63.6004, you...

2010-07-01

96

40 CFR Table 6 to Subpart Xxxx of... - Initial Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Emission Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part...STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards...Emission Limits for Tire Production Affected Sources As stated in § 63.5996, you...

2010-07-01

97

Proximity to forest edge does not affect crop production despite pollen limitation  

PubMed Central

A decline in pollination function has been linked to agriculture expansion and intensification. In northwest Argentina, pollinator visits to grapefruit, a self-compatible but pollinator-dependent crop, decline by approximately 50% at 1?km from forest edges. We evaluated whether this decrease in visitation also reduces the pollination service in this crop. We analysed the quantity and quality of pollen deposited on stigmas, and associated limitation of fruit production at increasing distances (edge: 10, 100, 500 and 1000?m) from the remnants of Yungas forest. We also examined the quantitative and qualitative efficiency of honeybees as pollen vectors. Pollen receipt and pollen tubes in styles decreased with increasing distance from forest edge; however, this decline did not affect fruit production. Supplementation of natural pollen with self- and cross-pollen revealed that both pollen quantity and quality limited fruit production. Despite pollen limitation, honeybees cannot raise fruit production because they often do not deposit sufficient high-quality pollen per visit to elicit fruit development. However, declines in visitation frequency well below seven visits during a flower's lifespan could decrease production beyond current yields. In this context, the preservation of forest remnants, which act as pollinator sources, could contribute to resilience in crop production. Like wild plants, pollen limitation of the yield among animal-pollinated crops may be common and indicative not only of pollinator scarcity, but also of poor pollination quality, whereby pollinator efficiency, rather than just abundance, can play a broader role than previously appreciated. PMID:18230596

Chacoff, Natacha P; Aizen, Marcelo A; Aschero, Valeria

2008-01-01

98

Proximity to forest edge does not affect crop production despite pollen limitation.  

PubMed

A decline in pollination function has been linked to agriculture expansion and intensification. In northwest Argentina, pollinator visits to grapefruit, a self-compatible but pollinator-dependent crop, decline by approximately 50% at 1km from forest edges. We evaluated whether this decrease in visitation also reduces the pollination service in this crop. We analysed the quantity and quality of pollen deposited on stigmas, and associated limitation of fruit production at increasing distances (edge: 10, 100, 500 and 1000m) from the remnants of Yungas forest. We also examined the quantitative and qualitative efficiency of honeybees as pollen vectors. Pollen receipt and pollen tubes in styles decreased with increasing distance from forest edge; however, this decline did not affect fruit production. Supplementation of natural pollen with self- and cross-pollen revealed that both pollen quantity and quality limited fruit production. Despite pollen limitation, honeybees cannot raise fruit production because they often do not deposit sufficient high-quality pollen per visit to elicit fruit development. However, declines in visitation frequency well below seven visits during a flower's lifespan could decrease production beyond current yields. In this context, the preservation of forest remnants, which act as pollinator sources, could contribute to resilience in crop production. Like wild plants, pollen limitation of the yield among animal-pollinated crops may be common and indicative not only of pollinator scarcity, but also of poor pollination quality, whereby pollinator efficiency, rather than just abundance, can play a broader role than previously appreciated. PMID:18230596

Chacoff, Natacha P; Aizen, Marcelo A; Aschero, Valeria

2008-04-22

99

Study of thrust force and torque in drilling carbon fibre reinforced plastics(CFRP) using twist drill brazed diamond  

Microsoft Academic Search

The Composites are difficult machining materials which widely used in aerospace industry due to their excellent mechanical properties. Tool wear and delamination are considered the major concern in manufacture the parts and assembly. The thrust force and torque affect the tool life and delamination mostly. This paper investigated the drilling force and torque of carbon fibred composite with carbide drilling

Liu Dong; Chen Wuyi; Chen Zhitong

2010-01-01

100

Spin-orbit torque opposing the Oersted torque in ultrathin Co/Pt bilayers  

SciTech Connect

Current-induced torques in ultrathin Co/Pt bilayers were investigated using an electrically driven ferromagnetic resonance technique. The angle dependence of the resonances, detected by a rectification effect as a voltage, was analysed to determine the symmetries and relative magnitudes of the spin-orbit torques. Both anti-damping (Slonczewski) and field-like torques were observed. As the ferromagnet thickness was reduced from 3 to 1?nm, the sign of the sum of the field-like torque and Oersted torque reversed. This observation is consistent with the emergence of a Rashba spin orbit torque in ultra-thin bilayers.

Skinner, T. D., E-mail: tds32@cam.ac.uk; Irvine, A. C.; Heiss, D.; Kurebayashi, H.; Ferguson, A. J., E-mail: ajf1006@cam.ac.uk [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Wang, M.; Hindmarch, A. T.; Rushforth, A. W. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2014-02-10

101

Balancing Control for Dispersed Generators Considering Torsional Torque Suppression and AVR Performance for Synchronous Generators  

NASA Astrophysics Data System (ADS)

Electric utility deregulation made possible for PPSs (Power Producer and Supplier) to entry the electricity market. PPSs are supposed to achieve 30-minute balancing control for stable supply of electric power. Meanwhile, load rejection and instantaneous voltage drop greatly affect turbine shafting, that is torsional torque oscillation. Therefore, PPSs have to consider reduction of torsional torque to prevent generator shaft damage. This paper propose the control system which enables to achieve both 30-minute balancing control and reduction of torsional torque by using H? controller. The effectiveness of proposed controller will be verified by using MATLAB.

Senjyu, Tomonobu; Omine, Eitaro; Hayashi, Daisuke; Muhando, Endusa Billy; Yona, Atsushi; Funabashi, Toshihisa

102

Gate-dependent spin-torque in a nanoconductor-based spin-valve  

NASA Astrophysics Data System (ADS)

This paper discusses the spin-torque effect in a spin-valve made out of two ferromagnetic leads connected through a coherent nanoconductor (NC), in the limit where a single channel of the NC lies near the Fermi energy of the leads. Due to quantum interferences inside the NC, the spin-torque presents clear qualitative differences with respect to the case of a multichannel disordered spin-valve. In particular, it can be modulated with the NC gate voltage. In principle, this modulation can be observed experimentally, assuming that the spin-torque affects a ferromagnetic nanodomain in direct contact with the NC.

Cottet, Audrey

2011-08-01

103

Climate change induced rainfall patterns affect wheat productivity and agroecosystem functioning dependent on soil types  

NASA Astrophysics Data System (ADS)

Wheat is a crop of global importance supplying more than half of the world's population with carbohydrates. We examined, whether climate change induced rainfall patterns towards less frequent but heavier events alter wheat agroecosystem productivity and functioning under three different soil types. Therefore, in a full-factorial experiment Triticum aestivum L. was cultivated in 3 m2 lysimeter plots containing the soil types sandy calcaric phaeozem, gleyic phaeozem or calcic chernozem. Prognosticated rainfall patterns based on regionalised climate change model calculations were compared with current long-term rainfall patterns; each treatment combination was replicated three times. Future rainfall patterns significantly reduced wheat growth and yield, reduced the leaf area index, accelerated crop development, reduced arbuscular mycorrhizal fungi colonisation of roots, increased weed density and the stable carbon isotope signature (?13C) of both old and young wheat leaves. Different soil types affected wheat growth and yield, ecosystem root production as well as weed abundance and biomass. The interaction between climate and soil type was significant only for the harvest index. Our results suggest that even slight changes in rainfall patterns can significantly affect the functioning of wheat agroecosystems. These rainfall effects seemed to be little influenced by soil types suggesting more general impacts of climate change across different soil types. Wheat production under future conditions will likely become more challenging as further concurrent climate change factors become prevalent.

Tabi Tataw, James; Baier, Fabian; Krottenthaler, Florian; Pachler, Bernadette; Schwaiger, Elisabeth; Whylidal, Stefan; Formayer, Herbert; Hösch, Johannes; Baumgarten, Andreas; Zaller, Johann G.

2014-05-01

104

Do non-native plant species affect the shape of productivity-diversity relationships?  

USGS Publications Warehouse

The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at different spatial scales, though little is known about the relative importance of physical and biological mechanisms causing this variation. Moreover, despite widespread concern about changes in species' global distributions, it remains unclear if and how such large-scale changes may affect this relationship. We present a new conceptual model of how invasive species might modulate relationships between primary production and species richness. We tested this model using long-term data on relationships between aboveground net primary production and species richness in six North American terrestrial ecosystems. We show that primary production and abundance of non-native species are both significant predictors of species richness, though we fail to detect effects of invasion extent on the shapes of the relationship between species richness and primary production.

Drake, J.M.; Cleland, E.E.; Horner-Devine, M. C.; Fleishman, E.; Bowles, C.; Smith, M.D.; Carney, K.; Emery, S.; Gramling, J.; Vandermast, D.B.; Grace, J.B.

2008-01-01

105

PREFACE: The Science of Making Torque from Wind 2014 (TORQUE 2014)  

NASA Astrophysics Data System (ADS)

The 186 papers in this volume constitute the proceedings of the fifth Science of Making Torque from Wind conference, which is organized by the European Academy of Wind Energy (EAWE, www.eawe.eu). The conference, also called Torque 2014, is held at the Technical University of Denmark (DTU) 17-20 June 2014. The EAWE conference series started in 2004 in Delft, the Netherlands. In 2007 it was held in Copenhagen, in 2010 in Heraklion, Greece, and then in 2012 in Oldenburg, Germany. The global yearly production of electrical energy by wind turbines has grown approximately by 25% annually over the last couple of decades and covers now 2-3% of the global electrical power consumption. In order to make a significant impact on one of the large challenges of our time, namely global warming, the growth has to continue for a decade or two yet. This in turn requires research and education in wind turbine aerodynamics and wind resources, the two topics which are the main subjects of this conference. Similar to the growth in electrical power production by wind is the growth in scientific papers about wind energy. Over the last decade the number of papers has also grown by about 25% annually, and many research based companies all over the world are founded. Hence, the wind energy research community is rapidly expanding and the Torque conference series offers a good opportunity to meet and exchange ideas. We hope that the Torque 2014 will heighten the quality of the wind energy research, while the participants will enjoy each others company in Copenhagen. Many people have been involved in producing the Torque 2014 proceedings. The work by more than two hundred reviewers ensuring the quality of the papers is greatly appreciated. The timely evaluation and coordination of the reviews would not have been possible without the work of sixteen ''section editors'' all from DTU Wind Energy: Christian Bak, Andreas Bechmann, Ferhat Bingöl, Ebba Dellwik, Nikolay Dimitrov, Gregor Giebel, Martin O L Hansen, Dorte Juul Jensen, Gunner Larsen, Helge Aagaard Madsen, Jakob Mann, Anand Natarajan, Ole Rathmann, Ameya Sathe, Jens Nørkær Sørensen and Niels Nørkær Sørensen, who are all co-editors of these proceedings. The resources provided by the Center for Computational Wind Turbine Aerodynamics and Atmospheric Turbulence funded by the Danish Council for Strategic Research grant no. 09-067216 and the Danish Ministry of Science, Innovation and Higher Education Technology and Production, grant no. 11- 117018 are gratefully acknowledged. We are also immensely indebted to the very responsive help and support from the editorial team at IoP, especially Sarah Toms and Anete Ashton, during the reviewing process of these proceedings. We are looking forward to meeting you in Copenhagen and also to Torque 2016, which will take place at the Technical University of Munich, Germany. Roskilde, Denmark, June 2014 Ebba Dellwik, Ameya Sathe and Jakob Mann Technical University of Denmark EAWE DTU

Mann, Jakob; Bak, Christian; Bechmann, Andreas; Bingöl, Ferhat; Dellwik, Ebba; Dimitrov, Nikolay; Giebel, Gregor; Hansen, Martin O. L.; Jensen, Dorte Juul; Larsen, Gunner; Aagaard Madsen, Helge; Natarajan, Anand; Rathmann, Ole; Sathe, Ameya; Nørkær Sørensen, Jens; Nørkær Sørensen, Niels

2014-06-01

106

Position Sensorless Vector Control for Permanent Magnet Synchronous Motors Based on Maximum Torque Control Frame  

Microsoft Academic Search

High efficiency drive can be achieved by the maximum torque-per-ampere (MTPA) control which used reluctance torque effectively. However, the calculations for estimating rotor position and for controlling the d-axis current are required. The motor parameters of inductance etc. that are easily affected by magnetic saturation are included in those calculations. This paper proposes a new MTPA control method, which is

Hajime Hida; Yoshio Tomigashi; Keiji Kishimoto

2007-01-01

107

Affective Technology, Affective Management, towards Affective Society  

Microsoft Academic Search

In this paper, the term affective is defined as “being capable to evoke affects in people’s mind” or “being capable to deliberate affects to be evoked in people’s\\u000a mind”. This paper discusses potential impact of concept of affectiveness on development of technological products and services, management, and value systems of societies.

Hiroyuki Umemuro

2009-01-01

108

Spatiotemporal evolution of hairpin eddies, Reynolds stress, and polymer torque in polymer drag-reduced turbulent channel flows.  

PubMed

To study the influence of dynamic interactions between turbulent vortical structures and polymer stress on turbulent friction drag reduction, a series of simulations of channel flow is performed. We obtain self-consistent evolution of an initial eddy in the presence of polymer stresses by utilizing the finitely extensible nonlinear elastic-Peterlin (FENE-P) model. The initial eddy is extracted by the conditional averages for the second quadrant event from fully turbulent Newtonian flow, and the initial polymer conformation fields are given by the solutions of the FENE-P model equations corresponding to the mean shear flow in the Newtonian case. At a relatively low Weissenberg number We(?) (=50), defined as the ratio of the polymer relaxation time to the wall time scale, the generation of new vortices is inhibited by polymer-induced countertorques. Thus fewer vortices are generated in the buffer layer. However, the head of the primary hairpin is unaffected by the polymer stress. At larger We(?) values (?100), the hairpin head becomes weaker and vortex autogeneration and Reynolds stress growth are almost entirely suppressed. The temporal evolution of the vortex strength and polymer torque magnitude reveals that polymer extension by the vortical motion results in a polymer torque that increases in magnitude with time until a maximum value is reached over a time scale comparable to the polymer relaxation time. The polymer torque retards the vortical motion and Reynolds stress production, which in turn weakens flow-induced chain extension and torque itself. An analysis of the vortex time scales reveals that with increasing We(?), vortical motions associated with a broader range of time scales are affected by the polymer stress. This is qualitatively consistent with Lumley's time criterion for the onset of drag reduction. PMID:23848767

Kim, Kyoungyoun; Sureshkumar, Radhakrishna

2013-06-01

109

40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2014 CFR

As stated in § 63.6004, you must show continuous compliance with the emission limits for tire production affected sources according to the following table: For . . . For the following emission limit . . . You must demonstrate continuous compliance by . . ....

2014-07-01

110

40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2012 CFR

As stated in § 63.6004, you must show continuous compliance with the emission limits for tire production affected sources according to the following table: For . . . For the following emission limit . . . You must demonstrate continuous compliance by . . ....

2012-07-01

111

40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2011 CFR

As stated in § 63.6004, you must show continuous compliance with the emission limits for tire production affected sources according to the following table: For . . . For the following emission limit . . . You must demonstrate continuous compliance by . . ....

2011-07-01

112

40 CFR Table 10 to Subpart Xxxx of... - Continuous Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2013 CFR

As stated in § 63.6004, you must show continuous compliance with the emission limits for tire production affected sources according to the following table: For . . . For the following emission limit . . . You must demonstrate continuous compliance by . . ....

2013-07-01

113

Torque control during lingual anterior retraction without posterior appliances  

PubMed Central

Objective To evaluate the factors that affect torque control during anterior retraction when utilizing the C-retractor with a palatal miniplate as an exclusive source of anchorage without posterior appliances. Methods The C-retractor was modeled using a 3-dimensional beam element (0.9-mm-diameter stainless-steel wire) attached to mesh bonding pads. Various vertical heights and 2 attachment positions for the lingual anterior retraction hooks (LARHs) were evaluated. A force of 200 g was applied from each side hook of the miniplate to the splinted segment of 6 or 8 anterior teeth. Results During anterior retraction, an increase in the LARH vertical height increased the amount of lingual root torque and intrusion of the incisors. In particular, with increasing vertical height, the tooth displacement pattern changed from controlled tipping to bodily displacement and then to lingual root displacement. The effects were enhanced when the LARH was located between the central and lateral incisors, as compared to when the LARH was located between the lateral incisors and canines. Conclusions Three-dimensional lingual anterior retraction of the 6 or 8 anterior teeth can be accomplished using the palatal miniplate as the only anchorage source. Using LARHs at different heights or positions affects the quality of torque and intrusion. PMID:23502971

Mo, Sung-Seo; Sung, Sang-Jin; Chung, Kyu-Rhim; Chun, Yun-Sic; Kook, Yoon-Ah; Nelson, Gerald

2013-01-01

114

Agent-patient similarity affects sentence structure in language production: evidence from subject omissions in Mandarin  

PubMed Central

Interference effects from semantically similar items are well-known in studies of single word production, where the presence of semantically similar distractor words slows picture naming. This article examines the consequences of this interference in sentence production and tests the hypothesis that in situations of high similarity-based interference, producers are more likely to omit one of the interfering elements than when there is low semantic similarity and thus low interference. This work investigated language production in Mandarin, which allows subject noun phrases to be omitted in discourse contexts in which the subject entity has been previously mentioned in the discourse. We hypothesize that Mandarin speakers omit the subject more often when the subject and the object entities are conceptually similar. A corpus analysis of simple transitive sentences found higher rates of subject omission when both the subject and object were animate (potentially yielding similarity-based interference) than when the subject was animate and object was inanimate. A second study manipulated subject-object animacy in a picture description task and replicated this result: participants omitted the animate subject more often when the object was also animate than when it was inanimate. These results suggest that similarity-based interference affects sentence forms, particularly when the agent of the action is mentioned in the sentence. Alternatives and mechanisms for this effect are discussed. PMID:25278915

Hsiao, Yaling; Gao, Yannan; MacDonald, Maryellen C.

2014-01-01

115

Male body size and condition affects sperm number and production rates in mosquitofish, Gambusia holbrooki.  

PubMed

Sperm number is an important predictor of paternity when there is sperm competition. Sperm number is often measured as maximum sperm reserves, but in species where mating is frequent, males will often be replenishing their reserves. Thus, variation in how quickly males can produce sperm is likely to be important in determining male success in sperm competition. Despite this, little is known about how male size, body condition or diet affects sperm production rates. We counted sperm number in large and small Gambusia holbrooki (eastern mosquitofish) after 3 weeks on either a high or low food diet. Sperm number was significantly higher in both larger males and in well-fed males. We then stripped ejaculates again either 1, 2, 3, 4 or 5 days later to investigate subsequent sperm production. The rate of sperm replenishment was influenced by an interaction between size and diet. Large, well-fed males had consistently high levels of sperm available over the 5 days (i.e. rapid replenishment), whereas small poorly fed males showed consistently low levels of sperm availability over the 5 days (i.e. slow replenishment). In contrast, large, poorly fed and small, well-fed males increased their sperm numbers over the first 3 days (i.e. intermediate replenishment). Our study highlights that when mating is frequent and sperm competition is high, size and condition dependence of maximal sperm number and of sperm production rate might both contribute to variation in male reproductive success. PMID:25403851

O'Dea, R E; Jennions, M D; Head, M L

2014-12-01

116

Greenhouse tomato limited cluster production systems: crop management practices affect yield  

NASA Technical Reports Server (NTRS)

Limited-cluster production systems may be a useful strategy to increase crop production and profitability for the greenhouse tomato (Lycopersicon esculentum Mill). In this study, using an ebb-and-flood hydroponics system, we modified plant architecture and spacing and determined the effects on fruit yield and harvest index at two light levels. Single-cluster plants pruned to allow two leaves above the cluster had 25% higher fruit yields than did plants pruned directly above the cluster; this was due to an increase in fruit weight, not fruit number. Both fruit yield and harvest index were greater for all single-cluster plants at the higher light level because of increases in both fruit weight and fruit number. Fruit yield for two-cluster plants was 30% to 40% higher than for single-cluster plants, and there was little difference in the dates or length of the harvest period. Fruit yield for three-cluster plants was not significantly different from that of two-cluster plants; moreover, the harvest period was delayed by 5 days. Plant density (5.5, 7.4, 9.2 plants/m2) affected fruit yield/plant, but not fruit yield/unit area. Given the higher costs for materials and labor associated with higher plant densities, a two-cluster crop at 5.5 plants/m2 with two leaves above the cluster was the best of the production system strategies tested.

Logendra, L. S.; Gianfagna, T. J.; Specca, D. R.; Janes, H. W.

2001-01-01

117

Self-oscillation in spin torque oscillator stabilized by field-like torque  

SciTech Connect

The effect of the field-like torque on the self-oscillation of the magnetization in spin torque oscillator with a perpendicularly magnetized free layer was studied theoretically. A stable self-oscillation at zero field is excited for negative ? while the magnetization dynamics stops for ??=?0 or ??>?0, where ? is the ratio between the spin torque and the field-like torque. The reason why only the negative ? induces the self-oscillation was explained from the view point of the energy balance between the spin torque and the damping. The oscillation power and frequency for various ? were also studied by numerical simulation.

Taniguchi, Tomohiro; Tsunegi, Sumito; Kubota, Hitoshi; Imamura, Hiroshi [National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba 305-8568 (Japan)

2014-04-14

118

40 CFR 1065.310 - Torque calibration.  

Code of Federal Regulations, 2012 CFR

...including dynamometer torque measurement transducers and...calibrate the torque-measurement system with a reference...reference meter such as strain gage or a proving ring...reference meter (such as a strain gage or proving ring...point where the force measurement is made to the...

2012-07-01

119

40 CFR 1065.310 - Torque calibration.  

Code of Federal Regulations, 2013 CFR

...including dynamometer torque measurement transducers and...calibrate the torque-measurement system with a reference...reference meter such as strain gage or a proving ring...reference meter (such as a strain gage or proving ring...point where the force measurement is made to the...

2013-07-01

120

Spin-orbit torques in action  

NASA Astrophysics Data System (ADS)

The spin-orbit interaction can generate torques that act on the magnetization of a ferromagnet. Here we examine recent experimental insights into spin-orbit torques, which have generated competing explanations and differing opinions over their potential application in memory devices.

Brataas, Arne; Hals, Kjetil M. D.

2014-02-01

121

Computed torque control with nonparametric regression models  

Microsoft Academic Search

Computed torque control allows the design of considerably more precise, energy-efficient and compliant controls for robots. However, the major obstacle is the requirement of an accurate model for torque generation, which cannot be obtained in some cases using rigid-body formulations due to unmodeled nonlinearities, such as complex friction or actuator dynamics. In such cases, models approximated from robot data present

Duy Nguyen-Tuong; Matthias Seeger; Jan Peters

2008-01-01

122

High torque bellows seal rotary drive  

NASA Technical Reports Server (NTRS)

Bellows seal rotary drive device was developed which allows high torque transmission through sealed compartments. Bearing friction which would normally be carried by sealing bellows in comparable devices is absorbed by universal-gimbal joint. It can be used to transmit high torque, low speed, rotary motion through sealed barriers to prevent contamination or escape of fluids.

Diaguila, A. J.; Macomber, J. W.; Adams, D. W.

1972-01-01

123

Magnetic Tweezers for the Measurement of Twist and Torque  

E-print Network

1 Magnetic Tweezers for the Measurement of Twist and Torque Authors: Jan n.h.dekker@tudelft.nl Corresponding author: Nynke H. Dekker Keywords: magnetic tweezers, magnetic torque tweezers, freely-orbiting magnetic tweezers, twist, torque

Dekker, Nynke

124

RADIOACTIVE MATERIAL PACKAGING TORQUE REQUIREMENTS COMPLIANCE  

SciTech Connect

Shipping containers used to transport radioactive material (RAM) in commerce employ a variety of closure mechanisms. Often, these closure mechanisms require a specific amount of torque be applied to a bolt, nut or other threaded fastener. It is important that the required preload is achieved so that the package testing and analysis is not invalidated for the purpose of protecting the public. Torque compliance is a means of ensuring closure preload, is a major factor in accomplishing the package functions of confinement/containment, sub-criticality, and shielding. This paper will address the importance of applying proper torque to package closures, discuss torque value nomenclature, and present one methodology to ensure torque compliance is achieved.

Watkins, R.; Leduc, D.

2011-03-24

125

Environmental Qualification of an Actuator Torque Switch  

SciTech Connect

Environmental qualification testing was performed on a modified Limitorque torque switch for the torque switch safety functions in the Limitorque type SMB actuators located inside and outside containment in a nuclear power plant. The torque switch specimen was installed in a Limitorque SMB-1 electric actuator mounted on an 8'' Velan gate valve and operated with a customized programmable logic controller to allow normal torque switch behaviour to be observed. The present paper describes the qualification testing performed. The modified torque switch was aged to a 30-year service life at the normal service conditions for both inside and outside containment. Aging included radiation, thermal and cycle aging. A seismic test and then a combined Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB) steam accident simulation were followed. After each stage of aging, functional tests were done to confirm normal insulation resistance, normal contact resistance and normal operation. (authors)

Chan, A.M.; Barreca, S.L. [Kinectrics, Inc., 800 Kipling Avenue Toronto, Ontario M8Z 6C4 (Canada); Kostela, T. [Ontario Power Generation, Inc., 700 University Avenue Toronto, Ontario, M5G 1X6 (Canada)

2006-07-01

126

Estimating Torque Imparted on Spacecraft Using Telemetry  

NASA Technical Reports Server (NTRS)

There have been a number of missions with spacecraft flying by planetary moons with atmospheres; there will be future missions with similar flybys. When a spacecraft such as Cassini flies by a moon with an atmosphere, the spacecraft will experience an atmospheric torque. This torque could be used to determine the density of the atmosphere. This is because the relation between the atmospheric torque vector and the atmosphere density could be established analytically using the mass properties of the spacecraft, known drag coefficient of objects in free-molecular flow, and the spacecraft velocity relative to the moon. The density estimated in this way could be used to check results measured by science instruments. Since the proposed methodology could estimate disturbance torque as small as 0.02 N-m, it could also be used to estimate disturbance torque imparted on the spacecraft during high-altitude flybys.

Lee, Allan Y.; Wang, Eric K.; Macala, Glenn A.

2013-01-01

127

Fixed Torque Dynamo and Motor Model  

NSDL National Science Digital Library

The Fixed Torque Dynamo and Motor Model solves the coupled differential equations for an electric motor driven by a dynamo (generator). The model can be used as to illustrate elementary instabilities or bifurcations discussed in courses about nonlinear oscillators and dynamical systems. When the dynamo is driven at constant torque, chaotic reversals of the generated current and of the angular rotation of the motor are observed. The main window displays the dynamo angular velocity ?1, motor angular velocity ?2 and current I time series and a second window displays the phase space. The stator current Is (A), torque T (Nâ¢m), and resistance R (ohm) are adjustable. The Fixed Torque Dynamo and Motor Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double click the ejs_chaos_FixedTorqueDynamoAndMotor.jar file to run the program if Java is installed.

Christian, Wolfgang

2011-11-23

128

Torque requirement of rotating rods in airflow  

NASA Technical Reports Server (NTRS)

Experiments were performed to determine the torque required for rotating a rotor disk fitted with a number of radially arranged rods placed into a ducted airflow. An array of stationary rods, also radially arranged, was placed upstream close to the rotor with a small gap between the rods to cause wake interference. The results show that torque generally increased with airflow and the rate of increase varied considerably. At lower values of airflow, the rate of increase was larger than at higher airflow, and definite torque peaks occurred at certain airflow rates, where the torque attained a maximum within the test airflow range. During the test, a maximum blade passage frequency of 2037 Hz was attained. The results also show that the torque peaks occurred at the same Strouhal number for all speeds.

Barna, P. S.; Crossman, G. R.

1979-01-01

129

In-line rotating capacitive torque sensor  

DOEpatents

A method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources.

Kronberg, James W. (P.O. Box 385, Beach Island, SC 29841)

1991-01-01

130

Plasma Torque and Non-Ambipolar Transport  

NASA Astrophysics Data System (ADS)

Poloidal symmetry breaking in toroidal plasmas causes a damping of poloidal rotation and toroidal symmetry breaking a damping of toroidal rotation. These torques are transmitted by the magnetic field to the outside world. An upper limit exists on the torque that can be transmitted by a magnetic perturbation. This limit is enforced by shielding asymmetries from the plasma, which can be an important effect for toroidal asymmetries. The torque interaction of plasmas with magnetic fields can be either through an anisotropic pressure or by a drive for magnetic islands. The physics of both types of interactions are considered. Although the magnetic field is essential for transmitting the torque, it does not explicitly appear in the internal torque balance equations. This and other paradoxical effects are clarified.

Boozer, Allen

2009-05-01

131

Encoding of tangential torque in responses of tactile afferent fibres innervating the fingerpad of the monkey  

PubMed Central

Torsional loads are ubiquitous during everyday dextrous manipulations. We examined how information about torque is provided to the sensorimotor control system by populations of tactile afferents. Torsional loads of different magnitudes were applied in clockwise and anticlockwise directions to a standard central site on the fingertip. Three different background levels of contact (grip) force were used. The median nerve was exposed in anaesthetized monkeys and single unit responses recorded from 66 slowly adapting type-I (SA-I) and 31 fast adapting type-I (FA-I) afferents innervating the distal segments of the fingertips. Most afferents were excited by torque but some were suppressed. Responses of the majority of both afferent types were scaled by torque magnitude applied in one or other direction, with the majority of FA-I afferent responses and about half of SA-I afferent responses scaled in both directions. Torque direction affected responses in both afferent types, but more so for the SA-I afferents. Latencies of the first spike in FA-I afferent responses depended on the parameters of the torque. We used a Parzen window classifier to assess the capacity of the SA-I and FA-I afferent populations to discriminate, concurrently and in real-time, the three stimulus parameters, namely background normal force, torque magnitude and direction. Despite the potentially confounding interactions between stimulus parameters, both the SA-I and the FA-I populations could extract torque magnitude accurately. The FA-I afferents signalled torque magnitude earlier than did the SA-I afferents, but torque direction was extracted more rapidly and more accurately by the SA-I afferent population. PMID:20142274

Birznieks, Ingvars; Wheat, Heather E; Redmond, Stephen J; Salo, Lauren M; Lovell, Nigel H; Goodwin, Antony W

2010-01-01

132

International Space Station Attitude Control and Energy Storage Experiment: Effects of Flywheel Torque  

NASA Technical Reports Server (NTRS)

The Attitude Control and Energy Storage Experiment is currently under development for the International Space Station; two counter-rotating flywheels will be levitated with magnetic bearings and placed in vacuum housings. The primary objective of the experiment is to store and discharge energy, in combination with existing batteries, into the electrical power system. The secondary objective is to use the flywheels to exert torque on the Station; a simple torque profile has been designed so that the Station's Control Moment Gyroscopes will be assisted in maintaining torque equilibrium attitude. Two energy storage contingencies could result in the inadvertent application of torque by the flywheels to the Station: an emergency shutdown of one flywheel rotor while the other remains spinning, and energy storage with only one rotor instead of the counterrotating pair. Analysis of these two contingencies shows that attitude control and the microgravity environment will not be adversely affected.

Roithmayr, Carlos M.

1999-01-01

133

MicroRNAs targeting Nicastrin regulate A? production and are affected by target site polymorphisms  

PubMed Central

Despite the growing number of genome-wide association studies, the involvement of polymorphisms in microRNA target sites (polymiRTS) in Alzheimer’s disease (AD) remains poorly investigated. Recently, we have shown that AD-associated single-nucleotide polymorphisms (SNPs) present in the 3? untranslated region (3?UTR) of amyloid precursor protein (APP) could directly affect miRNA function. In theory, loss of microRNA (miRNA) function could lead to risk for AD by increasing APP expression and A? peptide production. In this study, we tested the hypothesis that Nicastrin, a ?-secretase subunit involved in A? generation, could be regulated by miRNAs, and consequently affected by 3?UTR polymorphisms. Bioinformatic analysis identified 22 putative miRNA binding sites located in or near Nicastrin 3?UTR polymorphisms. From these miRNA candidates, six were previously shown to be expressed in human brain. We identified miR-24, miR-186, and miR-455 as regulators of Nicastrin expression, both in vitro and under physiological conditions in human cells, which resulted in altered A? secretion. Using luciferase-based assays, we further demonstrated that rs113810300 and rs141849450 SNPs affected miRNA-mediated repression of Nicastrin. Notably, rs141849450 completely abolished the miR-455-mediated repression of Nicastrin. Finally, the rs141849450 variant was identified in 1 out of 511 AD cases but not in 631 controls. These observations set the stage for future studies exploring the role of miRNAs and 3?UTR polymorphisms in AD. PMID:25100943

Delay, Charlotte; Dorval, Véronique; Fok, Alice; Grenier-Boley, Benjamin; Lambert, Jean-Charles; Hsiung, G.-Y.; Hébert, Sébastien S.

2014-01-01

134

Klebsiella pneumoniae yfiRNB operon affects biofilm formation, polysaccharide production and drug susceptibility.  

PubMed

Klebsiella pneumoniae is an opportunistic pathogen important in hospital-acquired infections, which are complicated by the rise of drug-resistant strains and the capacity of cells to adhere to surfaces and form biofilms. In this work, we carried out an analysis of the genes in the K. pneumoniae yfiRNB operon, previously implicated in biofilm formation. The results indicated that in addition to the previously reported effect on type 3 fimbriae expression, this operon also affected biofilm formation due to changes in cellulose as part of the extracellular matrix. Deletion of yfiR resulted in enhanced biofilm formation and an altered colony phenotype indicative of cellulose overproduction when grown on solid indicator media. Extraction of polysaccharides and treatment with cellulase were consistent with the presence of cellulose in biofilms. The enhanced cellulose production did not, however, correlate with virulence as assessed using a Caenorhabditis elegans assay. In addition, cells bearing mutations in genes of the yfiRNB operon varied with respect to the WT control in terms of susceptibility to the antibiotics amikacin, ciprofloxacin, imipenem and meropenem. These results indicated that the yfiRNB operon is implicated in the production of exopolysaccharides that alter cell surface characteristics and the capacity to form biofilms - a phenotype that does not necessarily correlate with properties related with survival, such as resistance to antibiotics. PMID:25261190

Huertas, Mónica G; Zárate, Lina; Acosta, Iván C; Posada, Leonardo; Cruz, Diana P; Lozano, Marcela; Zambrano, María M

2014-12-01

135

40 CFR Table 9 to Subpart Xxxx of... - Minimum Data for Continuous Compliance With the Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...Compliance With the Emission Limits for Tire Production Affected Sources 9 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...Compliance With the Emission Limits for Tire Production Affected Sources As...

2010-07-01

136

Magnetostrictive torque sensor and its output characteristics  

NASA Astrophysics Data System (ADS)

A magnetostrictive torque sensor which can be installed in an automobile transmission to measure torque has been developed. The sensor shaft consists of two grooved sections. An ac bridge circuit formed by two coils surrounding the grooved sections and two fixed resistors is used to detect torque. The shaft material is a newly developed Cr-Mo steel. The sensitivity of the sensor is stable over a wide temperature range. However, the zero point of the sensor output drifted as much as 10% of the full scale of the sensor when the temperature was uniformly raised by 50 °C. To solve the temperature drift problem, the output characteristics of the bridge circuit were examined. It was found that the output signal (sinusoidal wave) from an initially balanced bridge consisted of torque and temperature components. Each component showed a constant phase angle. The torque phase angle was a fixed value whereas that of the temperature was controllable. A method was devised for separating the temperature phase angle from the torque one by about 90° and then eliminating the temperature component from the output signal. The resulting temperature drift of the sensor was less than 1% of the full measurement scale per 50 °C. This paper describes the shaft material, magnetostrictive properties of the shaft, torque and temperature dependence of coil impedances and output characteristics of the bridge circuit.

Shimada, Munekatsu

1993-05-01

137

Canceling Torque Caused By Boiloff Of Cryogen  

NASA Technical Reports Server (NTRS)

Proposed technique for cancellation of small torques caused by venting of cryogens from tanks in spacecraft adaptable to use in making small corrections in orientations of terrestrial scientific instruments. Torque eliminated by directing exhaust gas through "T" vent. To cancel remaining small torque, that side of "T" from which exhaust produces smaller thrust heated just enough to equalize opposing thrusts. Concept useful in situations in which conventional electromagnetic actuators not suitable because of constraints related to temperature, radiation, or vibration and equipment required to be robust, simple, reliable, light in weight, and without moving parts.

Bhandari, Pradeep

1993-01-01

138

A Computational Model of Torque Generation: Neural, Contractile, Metabolic and Musculoskeletal Components  

PubMed Central

The pathway of voluntary joint torque production includes motor neuron recruitment and rate-coding, sarcolemmal depolarization and calcium release by the sarcoplasmic reticulum, force generation by motor proteins within skeletal muscle, and force transmission by tendon across the joint. The direct source of energetic support for this process is ATP hydrolysis. It is possible to examine portions of this physiologic pathway using various in vivo and in vitro techniques, but an integrated view of the multiple processes that ultimately impact joint torque remains elusive. To address this gap, we present a comprehensive computational model of the combined neuromuscular and musculoskeletal systems that includes novel components related to intracellular bioenergetics function. Components representing excitatory drive, muscle activation, force generation, metabolic perturbations, and torque production during voluntary human ankle dorsiflexion were constructed, using a combination of experimentally-derived data and literature values. Simulation results were validated by comparison with torque and metabolic data obtained in vivo. The model successfully predicted peak and submaximal voluntary and electrically-elicited torque output, and accurately simulated the metabolic perturbations associated with voluntary contractions. This novel, comprehensive model could be used to better understand impact of global effectors such as age and disease on various components of the neuromuscular system, and ultimately, voluntary torque output. PMID:23405245

Callahan, Damien M.; Umberger, Brian R.; Kent-Braun, Jane A.

2013-01-01

139

Physical processes affecting availability of dissolved silicate for diatom production in the Arabian Sea  

NASA Technical Reports Server (NTRS)

A passive tracer to represent dissolved silicate concentrations, with biologically realistic uptake kinetics, is successfully incorporated into a three-dimensional, eddy-resolving, ocean circulation model of the Indian Ocean. Hypotheses are tested to evaluate physical processes which potentially affect the availability of silicate for diatom production in the Arabian Sea. An alternative mechanism is offered to the idea that open ocean upwelling is primarily responsible for the high, vertical nutrient flux and consequent large-scale phytoplankton bloom in the northwestern Arabian Sea during the southwest monsoon. Model results show that dissolved silicate in surface waters available for uptake by diatoms is primarily influenced by the intensity of nearshore upwelling from soutwest monsoonal wind forcing and by the offshore advective transport of surface waters. The upwelling, which in the model occurs within 200 +/- 50 km of the coast, appears to be a result of a combination of coastal upwelling, Elkman pumping, and divergence of the coastal flow as it turns offshore. Localized intensifications of silicate concentrations appear to be hydrodynamically driven and geographically correlated to coastal topographic features. The absence of diatoms in sediments of the eastern Arabian Basin is consistent with modeled distributional patterns of dissolved silicate resulting from limited westward advection of upwelled coastal waters from the western continental margin of India and rapid uptake of available silicate by diatoms. Concentrations of modeled silicate become sufficiently low to become unavailable for diatom production in the eastern Arabian Sea, a region between 61 deg E and 70 deg E at 8 deg N on the south, with the east and west boundaries converging on the north at approximately 67 deg E, 20 deg N.

Young, David K.; Kindle, John C.

1994-01-01

140

Denitrifying Bacterial Communities Affect Current Production and Nitrous Oxide Accumulation in a Microbial Fuel Cell  

PubMed Central

The biocathodic reduction of nitrate in Microbial Fuel Cells (MFCs) is an alternative to remove nitrogen in low carbon to nitrogen wastewater and relies entirely on microbial activity. In this paper the community composition of denitrifiers in the cathode of a MFC is analysed in relation to added electron acceptors (nitrate and nitrite) and organic matter in the cathode. Nitrate reducers and nitrite reducers were highly affected by the operational conditions and displayed high diversity. The number of retrieved species-level Operational Taxonomic Units (OTUs) for narG, napA, nirS and nirK genes was 11, 10, 31 and 22, respectively. In contrast, nitrous oxide reducers remained virtually unchanged at all conditions. About 90% of the retrieved nosZ sequences grouped in a single OTU with a high similarity with Oligotropha carboxidovorans nosZ gene. nirS-containing denitrifiers were dominant at all conditions and accounted for a significant amount of the total bacterial density. Current production decreased from 15.0 A·m?3 NCC (Net Cathodic Compartment), when nitrate was used as an electron acceptor, to 14.1 A·m?3 NCC in the case of nitrite. Contrarily, nitrous oxide (N2O) accumulation in the MFC was higher when nitrite was used as the main electron acceptor and accounted for 70% of gaseous nitrogen. Relative abundance of nitrite to nitrous oxide reducers, calculated as (qnirS+qnirK)/qnosZ, correlated positively with N2O emissions. Collectively, data indicate that bacteria catalysing the initial denitrification steps in a MFC are highly influenced by main electron acceptors and have a major influence on current production and N2O accumulation. PMID:23717427

Vilar-Sanz, Ariadna; Puig, Sebastià; García-Lledó, Arantzazu; Trias, Rosalia; Balaguer, M. Dolors; Colprim, Jesús; Bañeras, Lluís

2013-01-01

141

Plant Products Affect Growth and Digestive Efficiency of Cultured Florida Pompano (Trachinotus carolinus) Fed Compounded Diets  

PubMed Central

Costs of compounded diets containing fish meal as a primary protein source can be expected to rise as fish meal prices increase in response to static supply and growing demand. Alternatives to fish meal are needed to reduce production costs in many aquaculture enterprises. Some plant proteins are potential replacements for fish meal because of their amino acid composition, lower cost and wide availability. In this study, we measured utilization of soybean meal (SBM) and soy protein concentrate (SPC) by Florida pompano fed compounded diets, to determine the efficacy of these products as fish meal replacements. We also calculated apparent digestibility coefficients (ADCs) for canola meal (CM), corn gluten meal (CGM), and distillers dried grains with solubles (DDGS), following typical methods for digestibility trials. Juvenile Florida pompano were fed fish-meal-free diets containing graded levels of SBM and SPC, and weight gain was compared to a control diet that contained SBM, SPC, and fish meal. Fish fed diets that contained 25–30 percent SBM in combination with 43–39 percent SPC had weight gain equivalent to fish fed the control diet with fish meal, while weight gain of fish fed other soy combinations was significantly less than that of the control group. Apparent crude protein digestibility of CGM was significantly higher than that of DDGS but not significantly different from CM. Apparent energy digestibility of DDGS was significantly lower than CGM but significantly higher than CM. Findings suggested that composition of the reference diet used in a digestibility trial affects the values of calculated ADCs, in addition to the chemical and physical attributes of the test ingredient. PMID:22536344

Lech, Gregory P.; Reigh, Robert C.

2012-01-01

142

Balancing of a power-transmission shaft with the application of axial torque  

NASA Technical Reports Server (NTRS)

Evaluation of power transmission shafting for high-speed balancing has shown that when axial torque is applied, the imbalance response is altered. An increase in synchronous excitation always occurs if the axial torque level is altered from the value used during balancing; this was the case even when the shaft was balanced with torque applied. The twisting of the long slender shaft produces a change in the imbalance distribution sufficient to disrupt the balanced state. This paper presents a review of the analytic development of a weighted least squares approach to influence coefficient balancing and a review of experimental results. The analytic approach takes advantage of the fact that the past testing has shown that the influence coefficients are not significantly affected by the application of axial torque. The 3.60-m (12-ft) long aluminum shaft, 7.62 cm (3 in.) in diameter was run through the first flexural critical speed at torque levels ranging from zero-torque to 903.8 N-M (8000 lb-in.) in 112.9 N-M (1000 lb-in.) increments. Good comparison was achieved between predicted and experimental results.

Zorzi, E. S.; Flemming, D.

1980-01-01

143

EDITORIAL: Spin-transfer-torque-induced phenomena Spin-transfer-torque-induced phenomena  

Microsoft Academic Search

This cluster, consisting of five invited articles on spin-transfer torque, offers the very first review covering both magnetization reversal and domain-wall displacement induced by a spin-polarized current. Since the first theoretical proposal on spin-transfer torque---reported by Berger and Slonczewski independently---spin-transfer torque has been experimentally demonstrated in both vertical magnetoresistive nano-pillars and lateral ferromagnetic nano-wires. In the former structures, an electrical

Atsufumi Hirohata

2011-01-01

144

Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.  

PubMed

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight. PMID:20021772

Chen, Yigen; Poland, Therese M

2009-12-01

145

Predicting the Affects of Climate Change on Evapotranspiration and Agricultural Productivity of Semi-arid Basins  

NASA Astrophysics Data System (ADS)

Many arid and semi-arid regions around the world are experiencing water shortages that have become increasingly problematic. Since the late 1800s, upstream diversions in Nevada's Walker River have delivered irrigation supply to the surrounding agricultural fields resulting in a dramatic water level decline of the terminal Walker Lake. Salinity has also increased because the only outflow from the lake is evaporation from the lake surface. The Heihe River basin of northwestern China, a similar semi-arid catchment, is also facing losses from evaporation of terminal locations, agricultural diversions and evapotranspiration (ET) of crops. Irrigated agriculture is now experiencing increased competition for use of diminishing water resources while a demand for ecological conservation continues to grow. It is important to understand how the existing agriculture in these regions will respond as climate changes. Predicting the affects of climate change on groundwater flow, surface water flow, ET and agricultural productivity of the Walker and Heihe River basins is essential for future conservation of water resources. ET estimates from remote sensing techniques can provide estimates of crop water consumption. By determining similarities of both hydrologic cycles, critical components missing in both systems can be determined and predictions of impacts of climate change and human management strategies can be assessed.

Peri, L.; Tyler, S. W.; Zheng, C.; Pohll, G. M.; Yao, Y.

2013-12-01

146

Stellar rotation and the thermomagnetic torque  

NASA Technical Reports Server (NTRS)

It is noted that any reasonable assumption for the rotation rates of the interstellar clouds which must collapse to produce stars will result in stars which rotate much faster than suggested by observations if angular momentum is conserved throughout the collapse. The contribution of thermomagnetic torque, which can exist when a rarefied gas of polyatomic molecules is subjected to a magnetic field and a nonuniform temperature gradient, to the angular momentum of a collapsing protostellar object is examined in order to determine whether the magnitude of this torque is sufficient to slow down contracting protostellar clouds. Calculations are performed for two times during protostellar collapse when conditions may be favorable for thermomagnetic torque to play a role in angular-momentum considerations. The results indicate that this torque is apparently of no importance in determining or modifying stellar rotation during the early stages of stellar evolution.

Spear, G. G.; Wood, L. T.

1977-01-01

147

Noncontact torque measurement using stroboscopic techniques  

NASA Technical Reports Server (NTRS)

Noncontact torquemeter measures torsional deflection of rotating shaft and results are viewed on vernier scale. Magnitude of torque must be calculated from measured deflection. Device has no electric connections with the rotating member and is easy to use.

Leonard, W. H.

1972-01-01

148

Advanced Inductive Plasmas with Low Torque Startup  

NASA Astrophysics Data System (ADS)

Experiments on DIII-D have been performed to investigate the access and performance of advanced inductive discharges produced with zero net torque for the full duration of the plasma. With low torque, the plasma is particularly susceptible to 2/1 neoclassical tearing modes, which typically slow and lock, spoiling confinement and ending the high beta phase. Attempts to reduce the residual error field did not appear to significantly modify the stability at low torque. The addition of a modest amount of electron cyclotron heating (1 MW), configured for current drive aimed at the q=2 surface, appeared adequate to reduce the mode amplitude sufficiently to allow stable operation at ?N˜2.5 with q95˜4.3. Details of the stability, confinement and current profile, and comparison with typical high torque advanced inductive discharges will be presented.

Solomon, W. M.; Okabayashi, M.; Buttery, R. J.; Ferron, J. R.; Garofalo, A. M.; Jackson, G. L.; La Haye, R. J.; Luce, T. C.; Petty, C. C.; Politzer, P. A.; Welander, A. S.; Hanson, J. M.; in, Y.; Lanctot, M. J.; Turco, F.

2011-11-01

149

Direct torque control of induction machines using space vector modulation  

Microsoft Academic Search

A direct induction machine torque control method based on predictive, deadbeat control of the torque and flux is presented. By estimating the synchronous speed and the voltage behind the transient reactance, the change in torque and flux over the switching period is calculated. The stator voltage required to cause the torque and flux to be equal to their respective reference

Thomas G. Habetler; Francesco Profumo; Michele Pastorelli; Leon M. Tolbert

1992-01-01

150

Understanding, Measuring, and Designing User Experience: The Causal Relationship Between the Aesthetic Quality of Products and User Affect  

Microsoft Academic Search

This study sought to test the often-taken-granted assumption about the causal relationship between the aesthetic quality of\\u000a products and user affect by using affective priming paradigm. The results showed that when beautiful web-pages were used as\\u000a primes, the discrepancy between the response latencies to positive target and negative targets was larger than when the primes\\u000a were ugly-webpage. A parallel pattern

Haotian Zhou; Xiaolan Fu

2007-01-01

151

The Superrotation of Venus: Where's the Torque?  

E-print Network

The superrotation of the atmosphere of Venus requires a large torque on the up- per atmosphere. Mechanisms for providing a net balancing of this through waves or ionospheric motions to other parts of the atmosphere have been proposed but all have difficulties. Here we demonstrate that the albedo gradient from the day to night side of the cloud layer allows a gradient of light pressure that is sufficient to provide an external torque to drive this flow.

Chafin, Clifford

2014-01-01

152

Long-term affected energy production of waste to energy technologies identified by use of energy system analysis  

SciTech Connect

Affected energy production is often decisive for the outcome of consequential life-cycle assessments when comparing the potential environmental impact of products or services. Affected energy production is however difficult to determine. In this article the future long-term affected energy production is identified by use of energy system analysis. The focus is on different uses of waste for energy production. The Waste-to-Energy technologies analysed include co-combustion of coal and waste, anaerobic digestion and thermal gasification. The analysis is based on optimization of both investments and production of electricity, district heating and bio-fuel in a future possible energy system in 2025 in the countries of the Northern European electricity market (Denmark, Norway, Sweden, Finland and Germany). Scenarios with different CO{sub 2} quota costs are analysed. It is demonstrated that the waste incineration continues to treat the largest amount of waste. Investments in new waste incineration capacity may, however, be superseded by investments in new Waste-to-Energy technologies, particularly those utilising sorted fractions such as organic waste and refuse derived fuel. The changed use of waste proves to always affect a combination of technologies. What is affected varies among the different Waste-to-Energy technologies and is furthermore dependent on the CO{sub 2} quota costs and on the geographical scope. The necessity for investments in flexibility measures varies with the different technologies such as storage of heat and waste as well as expansion of district heating networks. Finally, inflexible technologies such as nuclear power plants are shown to be affected.

Muenster, M., E-mail: maem@risoe.dtu.d [Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark); Meibom, P. [Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark)

2010-12-15

153

Long-term affected energy production of waste to energy technologies identified by use of energy system analysis.  

PubMed

Affected energy production is often decisive for the outcome of consequential life-cycle assessments when comparing the potential environmental impact of products or services. Affected energy production is however difficult to determine. In this article the future long-term affected energy production is identified by use of energy system analysis. The focus is on different uses of waste for energy production. The Waste-to-Energy technologies analysed include co-combustion of coal and waste, anaerobic digestion and thermal gasification. The analysis is based on optimization of both investments and production of electricity, district heating and bio-fuel in a future possible energy system in 2025 in the countries of the Northern European electricity market (Denmark, Norway, Sweden, Finland and Germany). Scenarios with different CO(2) quota costs are analysed. It is demonstrated that the waste incineration continues to treat the largest amount of waste. Investments in new waste incineration capacity may, however, be superseded by investments in new Waste-to-Energy technologies, particularly those utilising sorted fractions such as organic waste and refuse derived fuel. The changed use of waste proves to always affect a combination of technologies. What is affected varies among the different Waste-to-Energy technologies and is furthermore dependent on the CO(2) quota costs and on the geographical scope. The necessity for investments in flexibility measures varies with the different technologies such as storage of heat and waste as well as expansion of district heating networks. Finally, inflexible technologies such as nuclear power plants are shown to be affected. PMID:20471819

Münster, M; Meibom, P

2010-12-01

154

Affect of Production cycle time in manufacturing supply chain management: A system dynamics approach  

Microsoft Academic Search

This paper deals with the development of a System Dynamics Model to study the influence of Production cycle time on: Production start rate, Work in progress, Production rate, Distribution inventory, Distribution rate, and Waste rate. The simulation results indicate that Production cycle time has a significant influence on `Bullwhip Effect' and there may be a need to stretch the Production

L. L. R. Rodrigues; R. Patel; B. Gopalakrishna; Pradeep Kumar Shetty; B. R. S. Rao

2010-01-01

155

Knudsen torque on heated micro beams  

NASA Astrophysics Data System (ADS)

Thermally induced mechanical loading has been shown to have significant effects on micro/nano objects immersed in a gas with a non-uniform temperature field. While the majority of existing studies and related applications focus on forces, we investigate the torque, and thus the rotational motion, produced by such a mechanism. Using the asymptotic analysis in the near continuum regime, the Knudsen torque acting on an asymmetrically located uniformly heated microbeam in a cold enclosure is investigated. The existence of a non-zero net torque is demonstrated. In addition, it has been found that by manipulating the system configuration, the rotational direction of the torque can be changed. Two types of rotational motion of the microbeam have been identified: the pendulum motion of a rectangular beam, and the unidirectional rotation of a cylindrical beam. A rotational frequency of 4 rpm can be achieved for the cylindrical beam with a diameter of 3?m at Kn = 0.005. Illustrated by the simulations using the direct simulation of Monte Carlo, the Knudsen torque can be much increased in the transition regime, demonstrating the potential of Knudsen torque serving as a rotation engine for micro/nano objects.

Li, Qi; Liang, Tengfei; Ye, Wenjing

2014-12-01

156

Factors affecting animal performance during the grazing season in a mountain cattle production system.  

PubMed

The factors influencing weight changes during the grazing season of Brown Swiss autumn-calving cows and Brown Swiss and Pirenaica spring-calving cows and their calves were studied over an 8-yr period in Spanish mountain conditions. The data set comprised 552 annual production cycles of cows that calved in two consecutive years. The animals grazed on alpine ranges during the summer and on forest pastures in the spring and autumn. They were housed during the winter and fed at different feeding levels (83 to 117% of their energy requirements) throughout the years of study. Weights were recorded every 3 mo and corrected to account for changes of digestive content and fetal growth, using theoretical relationships. Cow weight gains both on forest pastures and high mountain ranges were higher in autumn- than in spring-calving Brown Swiss cows, and therefore also during the whole grazing season (52.1 vs 7.7 kg, respectively, P < 0.001). Therefore, weight at calving and thereafter was significantly higher in autumn- than in spring-calving cows, which was associated with better reproductive performance (35.5 vs 49.1 d from calving to first ovulation, P < 0.01). In the spring-calving herd, Pirenaica cows had slightly higher gains than Brown Swiss cows during the grazing period (18.5 vs 7.7 kg, P < 0.001), mainly due to their higher gains on forest pastures, but their reproductive performance was similar (44.5 vs 49.1 d from calving to first ovulation, respectively, not statistically significant). Gains were higher in multiparous than in primiparous cows (31.1 vs 14.1 kg, respectively, P < 0.001), especially in the case of Brown Swiss cows, which were younger at first calving. Gains were affected by year of study (P < 0.001) and previous weight changes during the housing period (r = -0.35 and r = -0.21 in autumn- and spring-calving cows respectively, P < 0.001). In the case of autumn-calving cows, performance on pasture was also affected by the stage of pregnancy at housing (r = -0.51, P < 0.001). Growth rates through lactation were higher in autumn- than in spring-born calves (P < 0.001), although the shorter lactation period resulted in lower weight at weaning of the former (P < 0.001). Breed was a significant source of variation in the performance of spring-born calves, weights and gains being higher in Brown Swiss than in Pirenaica calves (P < 0.001). PMID:12078746

Casasús, I; Sanz, A; Villalba, D; Ferrer, R; Revilla, R

2002-06-01

157

Reverse torque failure of screw-shaped implants in baboons: baseline data for abutment torque application.  

PubMed

Torque failure for endosseous implants has been used as a biomechanical measure of anchorage, though the significance of such data is not known. A practical understanding of the resistance to torque failure of implant-tissue interfaces at stage 2 surgery would help in assigning torque levels for implant abutment-screw fastening. The purpose of this study was to measure torque failure levels of commercially pure (CP) titanium, Ti-6Al-4V, hydroxyapatite-coated (HA-coated) screw-shaped implants placed into the maxillae and mandibles of baboons. Implants identical in size were placed into the edentulous posterior maxillae and mandibles of six female baboons (n = 37 each group) using a standardized surgical protocol. Reverse-torque data were collected at postinsertion time intervals ranging from 3 to 4 months using a counterclockwise torque driver and the data were analyzed (repeated measures ANOVA) for torque differences related to time, biomaterial, and jaw. The HA-coated implants exhibited significantly greater torque-removal values compared to both metallic implants (HA: 186.0 Ncm [50.1]; Ti-6Al-4V: 78.6 Ncm [18.1]; CP Ti 74.0 Ncm [24.4]). Analysis of torque interactions with jaw showed no significant difference; however, the mandible was found to be greater than the maxilla in torque resistance for all groups tested. Understanding the risks in inferring animal data to human application, the clinical implications of these data suggest that the recommended torque level of 35 Ncm for abutment fastening may provide a margin of safety for most implants of similar design and material as used in this study.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7744435

Carr, A B; Larsen, P E; Papazoglou, E; McGlumphy, E

1995-01-01

158

Advanced Glycation End-Products affect transcription factors regulating insulin gene expression  

SciTech Connect

Advanced Glycation End-Products (AGEs) are generated by the covalent interaction of reducing sugars with proteins, lipids or nucleic acids. AGEs are implicated in diabetic complications and pancreatic {beta}-cell dysfunction. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T15 to high concentrations of AGEs leads to a significant decrease of insulin secretion and content. Insulin gene transcription is positively regulated by the beta cell specific transcription factor PDX-1 (Pancreatic and Duodenal Homeobox-1). On the contrary, the forkhead transcription factor FoxO1 inhibits PDX-1 gene transcription. Activity of FoxO1 is regulated by post-translational modifications: phosphorylation deactivates FoxO1, and acetylation prevents FoxO1 ubiquitination. In this work we investigated whether AGEs affect expression and subcellular localization of PDX-1 and FoxO1. HIT-T15 cells were cultured for 5 days in presence of AGEs. Cells were then lysed and processed for subcellular fractionation. We determined intracellular insulin content, then we assessed the expression and subcellular localization of PDX-1, FoxO1, phosphoFoxO1 and acetylFoxO1. As expected intracellular insulin content was lower in HIT-T15 cells cultured with AGEs. The results showed that AGEs decreased expression and nuclear localization of PDX-1, reduced phosphorylation of FoxO1, and increased expression and acetylation of FoxO1. These results suggest that AGEs decrease insulin content unbalancing transcription factors regulating insulin gene expression.

Puddu, A., E-mail: alep100@hotmail.com [Department of Internal Medicine and Medical Specialties, Viale Benedetto XV 6, 16132 Genova (Italy); Storace, D.; Odetti, P.; Viviani, G.L. [Department of Internal Medicine and Medical Specialties, Viale Benedetto XV 6, 16132 Genova (Italy)] [Department of Internal Medicine and Medical Specialties, Viale Benedetto XV 6, 16132 Genova (Italy)

2010-04-23

159

Equilibria of a charged artificial satellite subject to gravitational and Lorentz torques  

NASA Astrophysics Data System (ADS)

The attitude dynamics of a rigid artificial satellite subject to a gravity gradient and Lorentz torques in a circular orbit are considered. Lorentz torque is developed on the basis of the electrodynamic effects of the Lorentz force acting on the charged satellite's surface. We assume that the satellite is moving in a Low Earth Orbit in the geomagnetic field, which is considered to be a dipole. Our model of torque due to the Lorentz force is developed for an artificial satellite with a general shape, and the nonlinear differential equations of Euler are used to describe its attitude orientation. All equilibrium positions are determined and conditions for their existence are obtained. The numerical results show that the charge q and radius ?0 of the center of charge for the satellite provide a certain type of semi-passive control for the attitude of the satellite. The technique for this kind of control would be to increase or decrease the electrostatic screening on the satellite. The results obtained confirm that the change in charge can affect the magnitude of the Lorentz torque, which can also affect control of the satellite. Moreover, the relationship between magnitude of the Lorentz torque and inclination of the orbit is investigated.

Abdel-Aziz, Yehia A.; Shoaib, Muhammad

2014-07-01

160

Chimpanzee thumb muscle cross sections, moment arms and potential torques, and comparisons with humans.  

PubMed

This study investigates the morphological basis of differences between humans and chimpanzees in the kinematical and dynamical parameters of the musculature of the thumb. It is partly intended to test an hypothesis that human thumb muscles can exert significantly greater torques, due to larger muscle cross-sectional areas or to longer tendon moment arms or to both. We focus on the estimation of the potentials of thumb muscles to exert torques about joint axes in a sample of eight chimpanzee cadaver hands. The potential torque of a muscle is estimated by taking the product of a muscle's physiological cross-sectional area (an estimator of force) with its dynamical moment arm (derived from the slope of tendon excursion versus joint angular displacement, obtained during passive movements of cadaver thumb joints). Comparison of our results with similar data obtained for humans at the same Mayo Clinic laboratory shows significant differences between humans and chimpanzees in potential torque of most thumb muscles, those of humans generally exhibiting larger values. The primary reason for the larger torques in humans is that their average moment arms are significantly longer, permitting greater torque for a given muscle size. An additional finding is that chimpanzees and humans differ in the direction of secondary thumb metacarpal movements elicited by contraction of some muscles, as shown by differences in moment arm signs for a given movement in the same muscle. The differences appear to be related to differences in the musculo-skeletal structures of the trapeziometacarpal joint. PMID:10502241

Marzke, M W; Marzke, R F; Linscheid, R L; Smutz, P; Steinberg, B; Reece, S; An, K N

1999-10-01

161

The influence of lordosis on axial trunk torque and trunk muscle myoelectric activity.  

PubMed

Force contributions from the facet complex and posterior ligaments during the generation of axial torque are a function of lordosis, and it has been speculated that these forces together with muscular contributions play a role in axial trunk twisting. This study investigated the electromyographic activity of the trunk musculature and torque-generating capacity of the lumbar spine under the conditions of normal lordosis, hyperlordosis, and hypolordosis. Eleven male subjects volunteered for this study. The subjects performed isometric twisting efforts and maximum dynamic twisting efforts at 30 degrees/sec. The myoelectric activity levels (normalized to maximal amplitude obtained from nontwist activities) were quite low despite maximal efforts to generate axial torque (for example: approximately 60% maximum voluntary contraction for latissimus dorsi and even lower for the abdominals). Furthermore, changes in lordosis did not produce any consistent changes in muscle activity, although a hyperlordotic spine produced significantly smaller axial torques, and a hypolordotic spine smaller still. Larger torques were measured during all three conditions of lordosis, as the subjects rotated toward an untwisted position, and lower torques as the subjects rotated away. The opposite trend was observed, however, in myoelectric activity of the agonistic side of latissimus dorsi, the thoracic level of erector spine, and the lumbar level of erector spinae, i.e., larger amplitudes were observed as the trunk was twisted away from the untwisted position. These data suggest that tissues other than muscle (i.e., passive tissue) contribute significantly to axial torque production and that the flexed and twisted spine is less able to resist applied axial torques, possibly increasing the risk of torsional injury. PMID:1440008

McGill, S M

1992-10-01

162

Increasing elbow torque output of stroke patients by EMG-controlled external torque  

Microsoft Academic Search

A control algorithm for using homogenic EMG to control external assisting torque is developed for improving the elbow capability of stroke patients. The control signal to the manipulator is the difference between the weighted biceps and triceps EMG, so that the system moves with the forearm and provides assisting torque proportional to the voluntary effort. A nonlinear damping structure, mimicking

C. C. K. Lin; M. S. Ju; H. S. Cheng

2001-01-01

163

Autocompensation of torque ripple of direct drive motor by torque observer  

Microsoft Academic Search

Since a direct drive motor (DDM) does not require a reduction gear, the drive system can be made simple, and therefore it is used in high-precision robot and machine tool applications. However, without reduction gear, a disturbance torque is directly reflected to the motor shaft, and a torque ripple generated by the motor is directly transmitted to the load, causing

Nobuyuki Matsui; Tatsuo Makino; Hirokazu Satoh

1993-01-01

164

LOOK FOR THE SIGNATURE 1 Look for the Signature: How the Infusion of Personal Signatures Affects Product Evaluations and  

E-print Network

LOOK FOR THE SIGNATURE 1 Look for the Signature: How the Infusion of Personal Signatures Affects Product Evaluations and Purchase Behavior Abstract Brand managers often infuse personal signatures. The infusion of a personal signature into marketing stimuli thus influences consumption behavior by (1

Shyu, Mei-Ling

165

Force, Torque and Stiffness: Interactions in Perceptual Discrimination  

PubMed Central

Three experiments investigated whether force and torque cues interact in haptic discrimination of force, torque and stiffness, and if so, how. The statistical relation between force and torque was manipulated across four experimental conditions: Either one type of cue varied while the other was constant, or both varied so as to be positively correlated, negatively correlated, or uncorrelated. Experiment 1 showed that the subjects’ ability to discriminate force was improved by positively correlated torque but impaired with uncorrelated torque, as compared to the constant torque condition. Corresponding effects were found in Experiment 2 for the influence of force on torque discrimination. These findings indicate that force and torque are integrated in perception, rather than being processed as separate dimensions. A further experiment demonstrated facilitation of stiffness discrimination by correlated force and torque, whether the correlation was positive or negative. The findings suggest new means of augmenting haptic feedback to facilitate perception of the properties of soft objects. PMID:21359137

Wu, Bing; Klatzky, Roberta L.; Hollis, Ralph L.

2011-01-01

166

Feasibility study for convertible engine torque converter  

NASA Technical Reports Server (NTRS)

The feasibility study has shown that a dump/fill type torque converter has excellent potential for the convertible fan/shaft engine. The torque converter space requirement permits internal housing within the normal flow path of a turbofan engine at acceptable engine weight. The unit permits operating the engine in the turboshaft mode by decoupling the fan. To convert to turbofan mode, the torque converter overdrive capability bring the fan speed up to the power turbine speed to permit engagement of a mechanical lockup device when the shaft speed are synchronized. The conversion to turbofan mode can be made without drop of power turbine speed in less than 10 sec. Total thrust delivered to the aircraft by the proprotor, fan, and engine during tansient can be controlled to prevent loss of air speed or altitude. Heat rejection to the oil is low, and additional oil cooling capacity is not required. The turbofan engine aerodynamic design is basically uncompromised by convertibility and allows proper fan design for quiet and efficient cruise operation. Although the results of the feasibility study are exceedingly encouraging, it must be noted that they are based on extrapolation of limited existing data on torque converters. A component test program with three trial torque converter designs and concurrent computer modeling for fluid flow, stress, and dynamics, updated with test results from each unit, is recommended.

1985-01-01

167

Torque shudder protection device and method  

DOEpatents

A torque shudder protection device for an induction machine includes a flux command generator for supplying a steady state flux command and a torque shudder detector for supplying a status including a negative status to indicate a lack of torque shudder and a positive status to indicate a presence of torque shudder. A flux adapter uses the steady state flux command and the status to supply a present flux command identical to the steady state flux command for a negative status and different from the steady state flux command for a positive status. A limiter can receive the present flux command, prevent the present flux command from exceeding a predetermined maximum flux command magnitude, and supply the present flux command to a field oriented controller. After determining a critical electrical excitation frequency at which a torque shudder occurs for the induction machine, a flux adjuster can monitor the electrical excitation frequency of the induction machine and adjust a flux command to prevent the monitored electrical excitation frequency from reaching the critical electrical excitation frequency. 5 figs.

King, R.D.; Doncker, R.W.A.A. De.; Szczesny, P.M.

1997-03-11

168

Torque shudder protection device and method  

DOEpatents

A torque shudder protection device for an induction machine includes a flux command generator for supplying a steady state flux command and a torque shudder detector for supplying a status including a negative status to indicate a lack of torque shudder and a positive status to indicate a presence of torque shudder. A flux adapter uses the steady state flux command and the status to supply a present flux command identical to the steady state flux command for a negative status and different from the steady state flux command for a positive status. A limiter can receive the present flux command, prevent the present flux command from exceeding a predetermined maximum flux command magnitude, and supply the present flux command to a field oriented controller. After determining a critical electrical excitation frequency at which a torque shudder occurs for the induction machine, a flux adjuster can monitor the electrical excitation frequency of the induction machine and adjust a flux command to prevent the monitored electrical excitation frequency from reaching the critical electrical excitation frequency.

King, Robert D. (Schenectady, NY); De Doncker, Rik W. A. A. (Malvern, PA); Szczesny, Paul M. (Ballston Lake, NY)

1997-01-01

169

40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...  

Code of Federal Regulations, 2010 CFR

...composites production facility is a new affected source or an existing affected source? 63.5795 Section 63.5795 Protection...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards...

2010-07-01

170

Prophylactic Ankle Braces and Knee Varus-Valgus and Internal-External Rotation Torque  

PubMed Central

Context: Although prophylactic ankle bracing has been shown to be effective in reducing the incidence of ankle sprains, how these ankle braces might affect the other joints of the lower extremity is not clearly understood. Objective: To determine the effects of a prophylactic ankle brace on knee joint varus-valgus and internal-external rotation torque during a drop landing onto a slanted surface. Design: A repeated-measures design. Setting: Biomechanics research laboratory. Patients or Other Participants: Twenty-four physically active college students. Intervention(s): Participants were tested in a brace and no-brace condition. Main Outcome Measure(s): We measured 3 dependent variables: (1) peak ankle inversion-eversion torque, (2) peak knee varus-valgus torque, and (3) peak knee internal-external rotation torque. A forceplate was used to collect ground reaction force data, and 6 motion analysis cameras collected kinematic data during the unilateral drop landing. An adjustable bar was hung from the ceiling, and a slant board was positioned over the center of the forceplate, so that the ankle of the participant's dominant leg would invert upon landing. Peak torque was measured in both the brace and no-brace conditions. The average of the peak values in 3 trials for both conditions was used for the statistical analysis. Results: Ankle eversion torque was significantly greater in the brace condition (F1,23 = 19.75, P < .01). Knee external rotation torque was significantly greater in the brace condition (F1,23 = 4.33,P < .05). Valgus knee torque was smaller in the brace condition, but the difference was not statistically significant (F1,23 = 3.45,P = .08). Conclusions: This study provides an important first step in understanding the effects of prophylactic ankle bracing on other joints of the lower extremity. We found that prophylactic ankle bracing did have an effect on knee torque when the subject was landing on a slanted surface. Specifically, knee external rotation torque increased when the ankle was braced. PMID:17043690

Venesky, Kandy; Docherty, Carrie L; Dapena, Jesus; Schrader, John

2006-01-01

171

Reducing the net torque and flow ripple effects of multiple hydraulic piston motor drives  

NASA Technical Reports Server (NTRS)

The torque and flow ripple effects which result when multiple hydraulic motors are used to drive a single motion of a mechanical device can significantly affect the way in which the device performs. This article presents a mathematical model describing the torque and flow ripple effects of a bent-axis hydraulic piston motor. The model is used to show how the ripple magnitude can be reduced when multiple motors are used to drive a motion. A discussion of the hydraulic servo system of the 70-m antennas located with the Deep Space Network is included to demonstrate the application of the concepts presented.

Bartos, R. D.

1992-01-01

172

Evoked EMG-based torque prediction under muscle fatigue in implanted neural stimulation  

NASA Astrophysics Data System (ADS)

In patients with complete spinal cord injury, fatigue occurs rapidly and there is no proprioceptive feedback regarding the current muscle condition. Therefore, it is essential to monitor the muscle state and assess the expected muscle response to improve the current FES system toward adaptive force/torque control in the presence of muscle fatigue. Our team implanted neural and epimysial electrodes in a complete paraplegic patient in 1999. We carried out a case study, in the specific case of implanted stimulation, in order to verify the corresponding torque prediction based on stimulus evoked EMG (eEMG) when muscle fatigue is occurring during electrical stimulation. Indeed, in implanted stimulation, the relationship between stimulation parameters and output torques is more stable than external stimulation in which the electrode location strongly affects the quality of the recruitment. Thus, the assumption that changes in the stimulation-torque relationship would be mainly due to muscle fatigue can be made reasonably. The eEMG was proved to be correlated to the generated torque during the continuous stimulation while the frequency of eEMG also decreased during fatigue. The median frequency showed a similar variation trend to the mean absolute value of eEMG. Torque prediction during fatigue-inducing tests was performed based on eEMG in model cross-validation where the model was identified using recruitment test data. The torque prediction, apart from the potentiation period, showed acceptable tracking performances that would enable us to perform adaptive closed-loop control through implanted neural stimulation in the future.

Hayashibe, Mitsuhiro; Zhang, Qin; Guiraud, David; Fattal, Charles

2011-10-01

173

Reducing torque fluctuation in linkage drive shafts  

NASA Astrophysics Data System (ADS)

ESDU 92016 describes a range of established techniques for reducing the torque fluctuation in shafts that drive, or are driven by, planar linkages. The fluctuations result from inertial and gravitational effects of the moving links or from variable external loads. The peak-to-peak torque fluctuation may be reduced by appropriate techniques, of which six are considered. The design considerations involved in selection are discussed, and the principle underlying each technique is explained. General design guidance is given for each technique together with a table of typical characteristics so that the designer can assess rapidly the potential of each method for a particular application. The techniques covered include mass reduction of the links, dyad addition, addition of springs and dampers, use of a torsional-vibration isolator, and use of the flywheel (which does not reduce peak-to-peak torque fluctuation). A considerable bibliography lists references giving further information on each method.

1992-06-01

174

AX-5 space suit bearing torque investigation  

NASA Technical Reports Server (NTRS)

The symptoms and eventual resolution of a torque increase problem occurring with ball bearings in the joints of the AX-5 space suit are described. Starting torques that rose 5 to 10 times initial levels were observed in crew evaluation tests of the suit in a zero-g water tank. This bearing problem was identified as a blocking torque anomaly, observed previously in oscillatory gimbal bearings. A large matrix of lubricants, ball separator designs and materials were evaluated. None of these combinations showed sufficient tolerance to lubricant washout when repeatedly cycled in water. The problem was resolved by retrofitting a pressure compensated, water exclusion seal to the outboard side of the bearing cavity. The symptoms and possible remedies to blocking are discussed.

Loewenthal, Stuart; Vykukal, Vic; Mackendrick, Robert; Culbertson, Philip, Jr.

1990-01-01

175

Thomas precession: Where is the torque  

SciTech Connect

Special relativity appears to violate the conservation of angular momentum {bold L} since it predicts that an accelerated gyroscope will precess, i.e., {bold L} will change in the absence of any applied torque. The paradox is resolved in a simple example by demonstrating that there is a torque present. The mass distribution in the gyroscope undergoes a relativistic distortion, and the center of mass is displaced away from the position of the accelerating force. The resulting torque {tau}={ital d}{bold L}/{ital dt}. The model also shows the physical origins of spin-orbit coupling and of the oscillating term.'' A related calculation shows why a moving magnetic dipole has an {ital electric} dipole moment.

Muller, R.A. (Department of Physics and Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States))

1992-04-01

176

Torque limit of PM motors for field-weakening region operation  

DOEpatents

The invention includes a motor controller and technique for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by receiving a torque command, determining a physical torque limit based on a stator frequency, determining a theoretical torque limit based on a maximum available voltage and motor inductance ratio, and limiting the torque command to the smaller of the physical torque limit and the theoretical torque limit. Receiving the torque command may include normalizing the torque command to obtain a normalized torque command, determining the physical torque limit may include determining a normalized physical torque limit, determining a theoretical torque limit may include determining a normalized theoretical torque limit, and limiting the torque command may include limiting the normalized torque command to the smaller of the normalized physical torque limit and the normalized theoretical torque limit.

Royak, Semyon (Beachwood, OH); Harbaugh, Mark M. (Richfield, OH)

2012-02-14

177

Functional Keldysh theory of spin torques  

E-print Network

Functional Keldysh theory of spin torques R. A. Duine,1,* A. S. N??ez, 2,? Jairo Sinova,3,? and A. H. MacDonald4,? 1Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands 2Instituto de F?sica, PUCV... #1;Received 15 March 2007; published 18 June 2007#2; We present a microscopic treatment of current-induced torques and thermal fluctuations in itinerant ferro- magnets based on a functional formulation of the Keldysh formalism. We find...

Duine, R. A.; Nunez, A. S.; Sinova, Jairo; MacDonald, A. H.

2007-01-01

178

Ultrahigh Casimir interaction torque in nanowire systems.  

PubMed

We study the Casimir torque arising from the quantum electromagnetic fluctuations due to the interaction of two interfaces in a system formed by a dense array of metallic nanorods embedded in dielectric fluids. It is demonstrated that as a consequence of the ultrahigh density of photonic states in the nanowire array it is possible to channel the quantum fluctuations, and thereby boost the Casimir torque by several orders of magnitude as compared to other known systems (e.g., birefringent parallel plates). PMID:23787682

Morgado, Tiago A; Maslovski, Stanislav I; Silveirinha, Mário G

2013-06-17

179

An X-linked gene affecting mouse cell DNA synthesis also affects production of unintegrated linear and supercoiled DNA of murine leukemia virus.  

PubMed Central

To identify specific cellular factors which could be required during the synthesis of retroviral DNA, we have studied the replication of murine leukemia virus in mouse cells temperature sensitive for cell DNA synthesis (M. L. Slater and H. L. Ozer, Cell 7:289-295, 1976) and in several of their revertants. This mutation has previously been mapped on the X chromosome. We found that a short incubation of mutant cells at a nonpermissive temperature (39 degrees C) during the early part of the virus cycle (between 0- to 20-h postinfection) greatly inhibited virus production. This effect was not observed in revertant or wild-type cells. Molecular studies by the Southern transfer procedure of the unintegrated viral DNA synthesized in these cells at a permissive (33 degrees C) or nonpermissive temperature revealed that the levels of linear double-stranded viral DNA (8.8 kilobase pairs) were nearly identical in mutant or revertant cells incubated at 33 or 39 degrees C. However, the levels of two species of supercoiled viral DNA (with one or two long terminal repeats) were significantly lower in mutant cells incubated at 39 degrees C than in mutant cells incubated at 33 degrees C or in revertant cells incubated at 39 degrees C. Pulse-chase experiments showed that linear viral DNA made at 39 degrees C could not be converted into supercoiled viral DNA in mutant cells after a shift down to 33 degrees C. In contrast, such conversion was observed in revertant cells. Restriction endonuclease analysis did not detect differences in the structure of linear viral DNA made at 39 degrees C in mutant cells as compared to linear viral DNA isolated from the same cells at 33 degrees C. However, linear viral DNA made at 39 degrees C in mutant cells was poorly infectious in transfection assays. Taken together, these results strongly suggest that this X-linked gene, affecting mouse cell DNA synthesis, is operating in the early phase of murine leukemia virus replication. It seems to affect the level of production of unintegrated linear viral DNA only slightly while greatly reducing the infectivity of these molecules. In contrast, the accumulation of supercoiled viral DNA and subsequent progeny virus production are greatly reduced. Our pulse-chase experiments suggest that the apparent, but not yet identified, defect in linear viral DNA molecules might be responsible for their subsequent impaired circularization. Images PMID:6538258

Richter, A; Ozer, H L; DesGroseillers, L; Jolicoeur, P

1984-01-01

180

Physical aging behavior of the normal force and torque in polymer glasses  

NASA Astrophysics Data System (ADS)

In prior work we reported results from torsion in stress relaxation experiments in which we measured simultaneously, torque and normal force for two types of amorphous polymers. In one set the materials, poly(methyl methacrylate) (PMMA) and poly(ethyl methacrylate) (PEMA), have large sub-vitreous ? relaxations, while in the second set, polycarbonate (PC) and polysulfone (PSF), have weak ? relaxations. It was found that the prominent ? process influences the magnitude of the normal force modulus of PMMA and PEMA while the shear modulus is primarily affected by the ? process. In the present work we have extended our study on the effect of the ? and ? relaxations on the normal force and torque in amorphous polymers by examining the aging behavior of both torque and normal forces of PMMA, PEMA and PC measured at various temperatures between the ? and ? transitions and at a given deformation ( ?=0.04). It is found that for the PMMA the normal force shows aging behavior that is different from the torque response for the PMMA but ages in the same fashion as the torque for both the PEMA and the PC. These results are only partially consistent with the hypothesis that the ? process is the cause of the differing behaviors.

Flory, Anny; McKenna, Gregory B.

2010-11-01

181

Coupling between Switching Regulation and Torque Generation in Bacterial Flagellar Motor  

NASA Astrophysics Data System (ADS)

The bacterial flagellar motor plays a crucial role in both bacterial locomotion and chemotaxis. Recent experiments reveal that the switching dynamics of the motor depend on the rotation speed of the motor, and thus the motor torque, nonmonotonically. Here we present a unified mathematical model that treats motor torque generation based on experimental torque-speed curves and the torque-dependent switching based on the Ising type conformational spread model. The model successfully reproduces the observed switching rate as a function of the rotation speed, and provides a generic physical explanation independent of most details. A stator affects the switching dynamics through two mechanisms: accelerating the conformational flipping rate of individual rotor-switching units, which contributes most when the stator works at a high torque and thus a low speed; and influencing a larger number of rotor-switching units within unit time, whose contribution is the greatest when the motor rotates at a high speed. Consequently, the switching rate shows a maximum at intermediate speed, where the above two mechanisms find an optimal output. The load-switching relation may serve as a mechanism for sensing the physical environment, similar to the chemotaxis mechanism for sensing the chemical environment.

Xing, Jianhua; Bai, Fan; Minamino, Tohru; Wu, Zhanghan; Namba, Keiichi

2013-03-01

182

Galactoglucomannan Oligosaccharide Supplementation Affects Nutrient Digestibility, Fermentation End-Product Production, and Large Bowel Microbiota of the Dog  

Technology Transfer Automated Retrieval System (TEKTRAN)

A galactoglucomannan oligosaccharide (GGMO) obtained from fiberboard production was evaluated as a dietary supplement for dogs. The GGMO substrate contained high concentrations of oligosaccharides containing mannose, xylose, and glucose, with the mannose component accounting for 35% of dry matter. ...

183

How Does Information Technology Affect Productivity? Plant-Level Comparisons of Product Innovation, Process Improvement, and Worker Skills  

Microsoft Academic Search

To study the effects of new information technologies (IT) on productivity, we have assembled a unique data set on plants in one narrowly defined industry-valve manufacturing-and analyze several plant-level mechanisms through which IT could promote productivity growth. The empirical analysis reveals three main results. First, plants that adopt new IT-enhanced equipment also shift their business strategies by producing more customized

Ann Bartel; Casey Ichniowski; Kathryn Shaw

2007-01-01

184

Factors Affecting the Water Holding Capacity of Red Meat Products: A Review of Recent Research Advances  

Microsoft Academic Search

The water holding capacity of meat products is a very important quality attribute which has an influence on product yield, which in turn has economic implications, but is also important in terms of eating quality. A number of pre-and post-mortem factors influence the water holding capacity (WHC) of meat. During the growth and development of meat animals, genotype and animal

Qiaofen Cheng; Da-Wen Sun

2008-01-01

185

Does artificial snow production affect soil and vegetation of ski pistes? A review  

Microsoft Academic Search

The production of artificial snow and the use of snow additives in ski resorts have increased considerably during the last 20 years. Their ecological consequences are the subject of environmental concerns. This review compiles studies about the ecological implications of ski pistes preparation in general and of artificial snow production. The main direct impacts of ski piste preparation on the

Christian Rixen; Veronika Stoeckli; Walter Ammann

2003-01-01

186

Modification of the TRX2 gene dose in Saccharomyces cerevisiae affects hexokinase 2 gene regulation during wine yeast biomass production.  

PubMed

In the industrial yeast biomass production process, cells undergo an oxidative and other stresses which worsen the quality of the produced biomass. The overexpression of the thioredoxin codifying gene TRX2 in a wine Saccharomyces cerevisiae strain increases resistance to oxidative stress and industrial biomass production yield. We observed that variations in the TRX2 gene dose in wine yeast strains are relevant to determine the fermentative capacity throughout the industrial biomass production process. So, we studied the molecular changes using a transcriptomic approach under these conditions. The results provide an overview of the different metabolic pathways affected during industrial biomass production by TRX2 gene manipulation. The oxidative stress-related genes, like those related with the glutathione metabolism, presented outstanding variations. The data also allowed us to propose new thioredoxin targets in S. cerevisiae, such as hexokinase 2, with relevance for industrial fermentation performance. PMID:22223102

Gómez-Pastor, Rocío; Pérez-Torrado, Roberto; Matallana, Emilia

2012-05-01

187

Upper Middle Mainstem Columbia River Subbasin Water Quality Parameters Affected by Hydropower Production  

E-print Network

Appendix E Upper Middle Mainstem Columbia River Subbasin Water Quality Parameters Affected in the Columbia River was identified in the 1960's and 1970's as a potential detriment to salmon. Those concerns an average TDG level of 120 percent for the highest 12 hours of a day at the tailrace of the respective dam

188

Does selection for production traits affect the ability to cope with pathogens?   

E-print Network

, it was found that an incoming parasite dose of 150L3 and over was required to reduce weight gain in ROH mice fed a low protein diet and that this loss in weight gain was ameliorated by increased protein nutrition. Resilience of ROL mice was not affected...

Coltherd, Jennifer Carolyn

2011-06-27

189

14 CFR 23.397 - Limit control forces and -torques.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Limit control forces and -torques. 23.397 Section...COMMUTER CATEGORY AIRPLANES Structure Control Surface and System Loads § 23.397 Limit control forces and -torques. (a)...

2011-01-01

190

Factors affecting the production of eremofortin C and PR toxin in Penicillium roqueforti.  

PubMed Central

Eremofortin C (EC) and PR toxin are secondary metabolites of Penicillium roqueforti. Of 17 strains from the American Type Culture Collection that were studied for their ability to produce EC and PR toxin, 13 produced these metabolites. Toxin production by strains grown in solid media (10 cereals and 8 other agricultural products) was also investigated. Production of EC and PR toxin by fungi grown on cereals was greater than production of EC and PR toxin by fungi grown on legumes; fungi grown on corn produced the greatest amount of PR toxin. Addition of corn extracts to the culture medium greatly increased the production of EC and PR toxin in a coordinated manner, with no significant change in mycelial dry weight. The fungi produced the highest levels of EC and PR toxin at 20 to 24 degrees C depending on the strain. Toxin production was higher in stationary cultures than in cultures that were gently shaken at 120 rpm. The optimum pH for production of both EC and PR toxin was around pH 4.0. With regard to spore age, toxin levels did not change significantly when we used spores obtained from fungi that were grown at 24 degrees C for 3 up to 48 days. PMID:1768131

Chang, S C; Wei, Y H; Wei, D L; Chen, Y Y; Jong, S C

1991-01-01

191

A New Twist on Torque Labs  

ERIC Educational Resources Information Center

The traditional introductory-level meterstick-balancing lab assumes that students already know what torque is and that they readily identify it as a physical quantity of interest. We propose a modified version of this activity in which students qualitatively and quantitatively measure the amount of force required to keep the meterstick level. The…

Lane, W. Brian

2014-01-01

192

Torque and First-Class Levers  

NSDL National Science Digital Library

This inquiry activity should be done before students have studied the operation of a first-class lever. The activity could be used when discussing simple machines or torque. Although it involves the use of a lever, the activity is not really about simple

Horton, Michael

2009-05-30

193

40 CFR 1065.310 - Torque calibration.  

Code of Federal Regulations, 2014 CFR

...you calibrate the torque-measurement system with a reference force...reference length. (2) Strain gage, load transducer, or...reference meter (such as a strain gage, load transducer, or...the point where the force measurement is made to the...

2014-07-01

194

Air brake-dynamometer accurately measures torque  

NASA Technical Reports Server (NTRS)

Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

1965-01-01

195

Isokinetic Peak Torque in Young Wrestlers  

E-print Network

.3 + 1.5 years) volunteered to be measured for peak torque at 30, 180, and 300° • s'. In addition, underwater weighing was performed to determine body composition characteristics. The sample was divided into six age groups (8.1-8.9, n = 10; 9.0-9.9, n= 11...

Housh, Terry J.; Johnson, Glen O.; Housh, Dona J.; Stout, Jeffrey R.; Weir, Joseph P.; Weir, Loree L.; Eckerson, Joan M.

1996-01-01

196

High-torque magnetorheological fluid clutch  

Microsoft Academic Search

This study focuses on the design and characterization of a radial double-plate magneto-rheological fluid (MRF) clutch. The clutch's torque output can be controlled by adjusting the applied magnetic field. Electromagnetic finite element analysis (FEA) is performed to design and optimize the clutch. The shear stress distribution in MRF between the plates is theoretically predicted using the magnetic flux density distribution

Barkan M. Kavlicoglu; Faramarz Gordaninejad; Cahit A. Evrensel; Nigar Cobanoglu; Yanming Liu; Alan Fuchs; G. Korol

2002-01-01

197

Anatomy of a bearing torque problem  

NASA Technical Reports Server (NTRS)

In the early 1970s, an antenna despin drive was developed for MBB solar science satellite HELIOS. A problem with high bearing drag torque that was encountered on the two flight models of this drive, after successful tests were completed on twelve bearings, an engineering model, and the qualification unit is discussed.

Phinney, Damon D.

1987-01-01

198

Torque, Tension, And Friction In Bolts  

NASA Technical Reports Server (NTRS)

Improved equations predict relationships among tension in bolt, torque applied to bolt during installation, effective coefficient of friction, and number of times bolt has been installed. Bolted joints designed with new equations, use fewer and/or smaller bolts to carry same loads, reducing weights.

Morawski, Julian

1992-01-01

199

A force and torque tensegrity sensor  

Microsoft Academic Search

Tensegrity structures represent a special class of flexible structures, whose members can simultaneously perform the functions of strength, sensing, actuating, and feedback control. In this article we show how these structures intrinsic properties can be exploited to construct a smart sensor for simultaneous measurement of six different quantities: three orthogonal forces and three orthogonal torques. The static and dynamic characteristics

Cornel Sultan; Robert Skelton

2004-01-01

200

Tidal torques and local density maxima  

NASA Astrophysics Data System (ADS)

The authors have calculated the distribution of tidal torques acting on matter in the neighbourhood of local density maxima when the density perturbations are small. They find that high peaks experience higher torques than low peaks. The higher torques acting on the high peaks are counteracted by the shorter collapse time during which the torques can act. Which effect is dominant depends on the perturbation power spectrum: for power spectra characteristic of both cold dark matter and hot dark matter, the effects nearly cancel, and the total angular momentum acquired by a collapsing object is almost independent of the height of the peak. The authors have also calculated the distribution of ? - the dimensionless spin parameter - for density maxima. This quantity has a median value ??0.05 with no strong dependence on power spectrum, in good agreement with N-body simulations. The results indicate that it is not possible to account for the systematic differences in angular momentum properties of disc and elliptical galaxies simply by postulating that the latter arise from fluctuations of greater overdensity, contrary to some recent suggestions.

Heavens, Alan; Peacock, John

1988-05-01

201

75 FR 27614 - WTO Dispute Settlement Proceeding Regarding United States-Measures Affecting the Production and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...including clove, but would continue to permit the production and sale of other cigarettes, including cigarettes containing menthol, beginning 90 days after the legislation was signed into law. Indonesia appears to allege that this provision of the...

2010-05-17

202

Factors affecting the production of terpenes in seedlings of Pinus elliottii  

E-print Network

of terpenes was calculated using an internal standard, and data were subjected to statistical tests. For seedlings in the greenhouse, terpene content increased with seedling age. Upon wounding the seedlings, total resin acid production increased... significantly, and total monoterpene production also increased but not significantly. Seedlings responded to wounding very rapidly, within one hour. Fungal infection also induced resin acid increases, but not significantly. The compositions of terpenes were...

Ishihara, Hiroichi

1987-01-01

203

IL18 gene polymorphisms affect IL18 production capability by monocytes  

Microsoft Academic Search

We previously demonstrated a significant association between IL-18 gene polymorphism 105A\\/C and asthma. In this study, we investigated the relationship of IL-18 gene polymorphism to IL-18 production capability by monocytes. The frequency of gene polymorphisms including IL-18-105A\\/C and IL-18-?137G\\/C was determined by PCR analyses. The IL-18 production by monocytes stimulated without or with LPS or A23187+PMA for 1day was measured

Junsuke Arimitsu; Toru Hirano; Shinji Higa; Mari Kawai; Tetsuji Naka; Atsushi Ogata; Yoshihito Shima; Minoru Fujimoto; Tomoki Yamadori; Keisuke Hagiwara; Tomoharu Ohgawara; Yusuke Kuwabara; Ichiro Kawase; Toshio Tanaka

2006-01-01

204

Manure Phosphorus Extractability as Affected by Aluminum and Iron By-Products and Aerobic Composting  

Microsoft Academic Search

manure, respectively. The by-products also reduced the 0.5 M NH4F- extractable phosphorus (FEP) fraction. Shifts in P forms between Miller, 1994). The Al 3 reacted with ammonia released FEP and 0.1 M NaOH-extractable phosphorus (SHEP) depended during the decomposition of uric acid and organic N upon the Al and Fe contents of the by-products while the combined in poultry manure.

Thanh H. Dao; L. J. Sikora; A. Hamasaki; R. L. Chaney

2001-01-01

205

Submerged conidiation and product formation by Aspergillus niger at low specific growth rates are affected in aerial developmental mutants.  

PubMed

Exposure to an aerial environment or severe nutrient limitation induces asexual differentiation in filamentous fungi. Submerged cultivation of Aspergillus niger in carbon- and energy-limited retentostat cultures both induces and fuels conidiation. Physiological and transcriptomic analyses have revealed that this differentiation strongly affects product formation. Since conidiation is inherent in the aerial environment, we hypothesized that product formation near zero growth can be influenced by affecting differentiation or development of aerial hyphae in general. To investigate this idea, three developmental mutants (?fwnA, scl-1, and scl-2 mutants) that have no apparent vegetative growth defects were cultured in maltose-limited retentostat cultures. The secondary-metabolite profile of the wild-type strain defined flavasperone, aurasperone B, tensidol B, and two so far uncharacterized compounds as associated with conidium formation, while fumonisins B(2), B(4), and B(6) were characteristic of early response to nutrient limitation by the vegetative mycelium. The developmental mutants responded differently to the severe substrate limitation, which resulted in distinct profiles of growth and product formation. fwnA encodes the polyketide synthase responsible for melanin biosynthesis during aerial differentiation, and we show that conidial melanin synthesis in submerged retentostat cultures and aurasperone B production are fwnA dependent. The scl-1 and scl-2 strains are two UV mutants generated in the ?fwnA background that displayed reduced asexual conidiation and formed sclerotium-like structures on agar plates. The reduced conidiation phenotypes of the scl-1 and scl-2 strains are reflected in the retentostat cultivation and are accompanied by elimination or severely reduced accumulation of secondary metabolites and distinctly enhanced accumulation of extracellular protein. This investigation shows that submerged conidiation and product formation of a mitosporic fungus cultured at low specific growth rates can be fundamentally affected by interfering with the genetic program for differentiation of aerial hyphae, opening new perspectives for tailoring industrial performance. PMID:21652743

Jørgensen, Thomas R; Nielsen, Kristian F; Arentshorst, Mark; Park, Joohae; van den Hondel, Cees A; Frisvad, Jens C; Ram, Arthur F

2011-08-01

206

Submerged Conidiation and Product Formation by Aspergillus niger at Low Specific Growth Rates Are Affected in Aerial Developmental Mutants ?  

PubMed Central

Exposure to an aerial environment or severe nutrient limitation induces asexual differentiation in filamentous fungi. Submerged cultivation of Aspergillus niger in carbon- and energy-limited retentostat cultures both induces and fuels conidiation. Physiological and transcriptomic analyses have revealed that this differentiation strongly affects product formation. Since conidiation is inherent in the aerial environment, we hypothesized that product formation near zero growth can be influenced by affecting differentiation or development of aerial hyphae in general. To investigate this idea, three developmental mutants (?fwnA, scl-1, and scl-2 mutants) that have no apparent vegetative growth defects were cultured in maltose-limited retentostat cultures. The secondary-metabolite profile of the wild-type strain defined flavasperone, aurasperone B, tensidol B, and two so far uncharacterized compounds as associated with conidium formation, while fumonisins B2, B4, and B6 were characteristic of early response to nutrient limitation by the vegetative mycelium. The developmental mutants responded differently to the severe substrate limitation, which resulted in distinct profiles of growth and product formation. fwnA encodes the polyketide synthase responsible for melanin biosynthesis during aerial differentiation, and we show that conidial melanin synthesis in submerged retentostat cultures and aurasperone B production are fwnA dependent. The scl-1 and scl-2 strains are two UV mutants generated in the ?fwnA background that displayed reduced asexual conidiation and formed sclerotium-like structures on agar plates. The reduced conidiation phenotypes of the scl-1 and scl-2 strains are reflected in the retentostat cultivation and are accompanied by elimination or severely reduced accumulation of secondary metabolites and distinctly enhanced accumulation of extracellular protein. This investigation shows that submerged conidiation and product formation of a mitosporic fungus cultured at low specific growth rates can be fundamentally affected by interfering with the genetic program for differentiation of aerial hyphae, opening new perspectives for tailoring industrial performance. PMID:21652743

Jørgensen, Thomas R.; Nielsen, Kristian F.; Arentshorst, Mark; Park, JooHae; van den Hondel, Cees A.; Frisvad, Jens C.; Ram, Arthur F.

2011-01-01

207

Does species richness affect fine root biomass and production in young forest plantations?  

PubMed

Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined species composition from fine root biomass samples with the near-infrared reflectance spectroscopy method. We did not observe higher biomass or production in mixed stands compared to monocultures. Neither did we observe any differences in tree root length or fine root turnover. One reason for this could be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested that functional group identity (i.e. conifers vs. broadleaved species) can be more important for below-ground biomass and production than the species richness itself, as conifers seemed to be more competitive in colonising the soil volume, compared to broadleaved species. PMID:25300709

Domisch, Timo; Finér, Leena; Dawud, Seid Muhie; Vesterdal, Lars; Raulund-Rasmussen, Karsten

2015-02-01

208

Willingness to Use Microbicides Is Affected by the Importance of Product Characteristics, Use Parameters, and Protective Properties  

PubMed Central

Background Along with efficacy, a microbicide’s acceptability will be integral to its impact on the pandemic. Understanding Product Characteristics that users find most acceptable and determining who will use which type of product are key to optimizing use effectiveness. Objectives To evaluate psychometrically the Important Microbicide Characteristics (IMC) instrument and examine its relationship to willingness to use microbicides. Results Exploratory and confirmatory factor analyses revealed 2 IMC subscales (Cronbach’s coefficient ?: Product Characteristics subscale (? = 0.84) and Protective Properties subscale (? = 0.89)). Significant differences on Product Characteristics subscale scores were found for history of douching (P = 0.002) and employment status (P = 0.001). Whether a woman used a method to prevent pregnancy or sexually transmitted disease (STD) in the last 3 months (P < 0.001) and whether she used a condom during the last vaginal sex episode (P < 0.001) were significantly related to her rating of the importance of microbicides being contraceptive. Product Characteristics (r = 0.21) and Protective Properties (r = 0.27) subscale scores and whether a microbicide had contraceptive properties (r = 0.24) were all significantly associated (P < 0.001) with willingness to use microbicides. Conclusions Formulation and use characteristics and product function(s) affect willingness to use microbicides and should continue to be addressed in product development. The IMC instrument serves as a template for future studies of candidate microbicides. PMID:17325607

Morrow, Kathleen M.; Fava, Joseph L.; Rosen, Rochelle K.; Vargas, Sara; Barroso, Candelaria; Christensen, Anna L.; Woodsong, Cynthia; Severy, Lawrence

2008-01-01

209

Galactoglucomannan oligosaccharide Supplementation affects Nutrient Digestibility, Fermentation End-product Production, and Large Bowel Microbiota of the Dog  

Technology Transfer Automated Retrieval System (TEKTRAN)

A galactoglucomannan oligosaccharide (GGMO) obtained from fiberboard production was evaluated as a dietary supplement for dogs. The GGMO substrate contained high concentrations of mannose, xylose, and glucose oligosaccharides. Adult dogs assigned to a 6x6 Latin square design were fed six diets, ea...

210

Pearl millet: parboiling methods and factors affecting the process and cooked product  

E-print Network

(Chairman of Committee) alph D. Waniska (Member) Ronald L. Richter (Member) Ronald L. Richter (Chair, Faculty of Food Science) Edward C A Rung (Head of Department) August 1991 ABSTRACT Pearl Millet: Parboiling Methods and Factors Affecting... cm deep), and dried by various methods described later. TABLE 2. 1 Physical Properties of the Control Pearl Millet Samples. Kernel Size' (WxL ) Endosperm Kernel Sample Texture Appearance 1, 000-Kernel Test Weight Moisture Density Weight (SS...

Clegg, Chally Joel

1991-01-01

211

Commutation-Torque-Ripple Minimization in Direct-Torque-Controlled PM Brushless DC Drives  

Microsoft Academic Search

This paper describes an improved implementation of direct torque control (DTC) to a permanent-magnet brushless dc (BLDC) drive. The commutation torque ripple, which occurs every 60deg elec. in a conventional three-phase BLDC machine with two-phase 120deg elec. conduction, is reduced by employing a hybrid two- and three-phase switching mode during the commutation periods. It is based on the criterion of

Yong Liu; Z. Q. Zhu; David Howe

2007-01-01

212

A modified direct torque control for induction motor sensorless drive  

Microsoft Academic Search

Direct torque control (DTC) is known to produce quick and robust response in AC drives. However, during steady state, notable torque, flux and current pulsations occur. They are reflected in speed estimation, speed response, and also in increased acoustical noise. This paper introduces a new direct torque and flux control based on space-vector modulation (DTC-SVM) for induction motor sensorless drives.

Cristian Lascu; Ion Boldea; Frede Blaabjerg

2000-01-01

213

Torque sensorless control in multidegree-of-freedom manipulator  

Microsoft Academic Search

A torque sensorless control for a multi-degree-of-freedom manipulator is described. In the method, two disturbance observers are applied to each joint. One is used to realize a robust motion controller. The other is used to obtain a sensorless torque controller. A robust acceleration controller based on the disturbance observer is shown. To obtain the sensorless torque control, it is necessary

Toshiyuki Murakami; Fangming Yu; Kouhei Ohnishi

1993-01-01

214

An automated procedure for analyzing the effects of vortex-induced fin pressure on roll torque for a finned body of revolution.  

SciTech Connect

In flight tests, certain finned bodies of revolution firing lateral jets experience slower spin rates than expected. The primary cause for the reduced spin rate is the interaction between the lateral jets and the freestream air flowing past the body. This interaction produces vortices that interact with the fins (Vortex-Fin Interaction (VFI)) altering the pressure distribution over the fins and creating torque that counteracts the desired spin (counter torque). The current task is to develop an automated procedure for analyzing the pressures measured at an array of points on the fin surfaces of a body tested in a production-scale wind tunnel to determine the VFI-induced roll torque and compare it to the roll torque experimentally measured with an aerodynamic balance. Basic pressure, force, and torque relationships were applied to finite elements defined by the pressure measurement locations and integrated across the fin surface. The integrated fin pressures will help assess the distinct contributions of the individual fins to the counter torque and aid in correlating the counter torque with the positions and strengths of the vortices. The methodology produced comparisons of the effects of VFI for varying flow conditions such as freestream Mach number and dynamic pressure. The results show that for some cases the calculated counter torque agreed with the measured counter torque; however, the results were less consistent with increased freestream Mach numbers and dynamic pressures.

Vijlee, Shazib Z.

2004-09-01

215

Quality of dissolved organic matter affects planktonic but not biofilm bacterial production in streams.  

PubMed

Streams and rivers are important sites of organic carbon mineralization which is dependent on the land use within river catchments. Here we tested whether planktonic and epilithic biofilm bacteria differ in their response to the quality of dissolved organic carbon (DOC). Thus, planktonic and biofilm bacterial production was compared with patterns of DOC along a land-use gradient in the Bode catchment area (Germany). The freshness index of DOC was positively related to the proportion of agricultural area in the catchment. The humification index correlated with the proportion of forest area. Abundance and production of planktonic bacteria were lower in headwaters than at downstream sites. Planktonic production was weakly correlated to the total concentration of DOC but more strongly to quality-measures as revealed by spectra indexes, i.e. positively to the freshness index and negatively to the humification index. In contrast to planktonic bacteria, abundance and production of biofilm bacteria were independent of DOC quality. This finding may be explained by the association of biofilm bacteria with benthic algae and an extracellular matrix which represent additional substrate sources. The data show that planktonic bacteria seem to be regulated at a landscape scale controlled by land use, whereas biofilm bacteria are regulated at a biofilm matrix scale controlled by autochthonous production. Thus, the effects of catchment-scale land use changes on ecosystem processes are likely lower in small streams dominated by biofilm bacteria than in larger streams dominated by planktonic bacteria. PMID:25460970

Kamjunke, Norbert; Herzsprung, Peter; Neu, Thomas R

2015-02-15

216

Different blood and sugar feeding regimes affect the productivity of Anopheles arabiensis colonies (Diptera: Culicidae).  

PubMed

The success of the sterile insect technique for the management of mosquito populations depends on the release of large numbers of competitive sterile male insects. Sustainable mosquito production can only be obtained when proper mass-rearing equipment and adequate methods are available, including those to feed blood to the female mosquitoes. The blood feeding apparatus Hemotek consists of a small aluminum plate to which a collagen membrane is fixed and filled with blood kept warm by an electric heating element. A larger aluminum plate was developed to feed a larger number of female mosquitoes with blood that is kept at a constant temperature. The effect of different blood feeding regimes (feeding frequency and time the blood is kept in the Hemotek) and sugar deprivation before blood feeding on egg production of female Anopheles arabiensis Patton was tested. Egg production was higher when blood was offered to the mosquitoes every day as compared with every 2 or 4 d. Sugar deprivation for 7 h before blood feeding enhanced egg production by 50% compared with female mosquitoes that had continuous access to sugar. Neither male nor female survival was impaired. Finally, we showed that the same blood could be kept warm and used over several hours to feed mosquitoes in multiple cages without any impact on egg production or hatch rate. Being able to use the same blood over extended periods would save considerable time, handling, and funds. PMID:23540122

Damiens, D; Soliban, S M; Balestrino, F; Alsir, R; Vreysen, M J B; Gilles, J R L

2013-03-01

217

Current-induced magnetic vortex motion by spin-transfer torque  

Microsoft Academic Search

We investigate the dynamics of a magnetic vortex driven by spin-transfer torque due to spin current in the adiabatic case. The vortex core represented by collective coordinate experiences a transverse force proportional to the product of spin current and gyrovector, which can be interpreted as the geometric force determined by topological charges. We show that this force is just a

Junya Shibata; Yoshinobu Nakatani; Gen Tatara; Hiroshi Kohno; Yoshichika Otani

2006-01-01

218

Split torque type gearbox fault detection using acoustic emission and vibration sensors  

Microsoft Academic Search

In comparison with a traditional planetary gearbox, the split torque gearbox (STG) potentially offers lower weight, increased reliability, and improved efficiency. These benefits have driven the helicopter OEMs to develop products using the STG. However, this may pose a challenge for the current gear analysis methods used in Health and Usage Monitoring Systems (HUMS). Gear analysis uses time synchronous averages

David He; Ruoyu Li; Eric Bechhoefer

2010-01-01

219

Rib Torque Does Not Assist Resting Tidal Expiration or Most Conversational Speech Expiration  

ERIC Educational Resources Information Center

Purpose: This research note discusses a common misconception in speech science and speech-language pathology textbooks that rib torque (i.e., "rotational stress") assists resting tidal expiration and conversational speech production. Method: The nature of this misconception is considered. Conclusion: An alternate conceptualization is offered that…

Hixon, Thomas J.

2006-01-01

220

Influence of alternate slot openings on torque-speed characteristics and cogging torque of fractional slot IPM brushless AC machines  

Microsoft Academic Search

This paper presents a comparative study of torque- speed characteristics and cogging torque in three interior permanent magnet (IPM) brushless AC machines having different slot openings, viz. open slot, closed slot and hybrid slot (sandwiched open and closed slot), and unskewed and step skewed rotors. The influence of such alternate slot openings on the torque-speed characteristics, magnetic cross-coupling level and

Z. Azar; Z. Q. Zhu; G. Ombach

2011-01-01

221

Sunflower, soybean, and grain sorghum crop production as affected by dripline depth  

Technology Transfer Automated Retrieval System (TEKTRAN)

A five-year field study (2004-2008) using irrigation water from an unlined surface reservoir was conducted to examine the effect of dripline depth (0.2, 0.3, 0.4, 0.5, or 0.6 m) on subsurface drip-irrigated rotational crop production of sunflower, soybean, and grain sorghum on a deep silt loam soil ...

222

Phosphoribosyl pyrophosphate synthetase activity affects growth and riboflavin production in Ashbya gossypii  

PubMed Central

Background Phosphoribosyl pyrophosphate (PRPP) is a central compound for cellular metabolism and may be considered as a link between carbon and nitrogen metabolism. PRPP is directly involved in the de novo and salvage biosynthesis of GTP, which is the immediate precursor of riboflavin. The industrial production of this vitamin using the fungus Ashbya gossypii is an important biotechnological process that is strongly influenced by substrate availability. Results Here we describe the characterization and manipulation of two genes of A. gossypii encoding PRPP synthetase (AGR371C and AGL080C). We show that the AGR371C and AGL080C gene products participate in PRPP synthesis and exhibit inhibition by ADP. We also observed a major contribution of AGL080C to total PRPP synthetase activity, which was confirmed by an evident growth defect of the ?agl080c strain. Moreover, we report the overexpression of wild-type and mutant deregulated isoforms of Agr371cp and Agl080cp that significantly enhanced the production of riboflavin in the engineered A. gossypii strains. Conclusion It is shown that alterations in PRPP synthetase activity have pleiotropic effects on the fungal growth pattern and that an increase in PRPP synthetase enzymatic activity can be used to enhance riboflavin production in A. gossypii. PMID:18782443

Jiménez, Alberto; Santos, María A; Revuelta, José L

2008-01-01

223

Seed Composition as Affected by Planting Date and Genotypic differences in Early Soybean Production System.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Information on the effect of planting date on soybean composition in the Early Soybean Production System in the mid-south U.S.A. is limited. Therefore, a field experiment was conducted to evaluate the effect of planting date and cultivar differences on protein, oil, and fatty acids in selected soybe...

224

Cultivar, harvest date, and nitrogen fertilization affect production and quality of fall oat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous research has shown that oat (Avena sativa L.) has promise as a fall-forage option for dairy producers. In addition, dairy producers often have a recurring need to identify opportunity windows for manure hauling other than before or after production of corn (Zea mays L.). Our objectives were...

225

Moving beyond Frontiers: How Institutional Context Affects Degree Production and Student Aspirations in STEM  

ERIC Educational Resources Information Center

Colleges and universities in the U.S. face increasing pressure from policymakers and corporate leaders to increase their production of undergraduate degrees in science, technology, engineering, and mathematics (STEM). These pressures stem from a need to maintain the country's global economic competitiveness in science and engineering innovation.…

Eagan, Mark Kevin, Jr.

2010-01-01

226

Preference for drinking warm water during heat stress affects milk production in food-deprived goats  

Microsoft Academic Search

Food deprivation leads to diminished water intake and decreased milk production in lactating goats. The aim of this study was to determine whether these effects could be alleviated by offering six lactating goats (Capra hircus) warm water to drink at normal or hot ambient temperatures. The food deprivation period was started on Day — 1 at 0700 h by feeding

K. Olsson; K. Cvek; E. Hydbring

1997-01-01

227

Nanofiber alignment and direction of mechanical strain affect the ECM production of human ACL fibroblast  

Microsoft Academic Search

The effects of fiber alignment and direction of mechanical stimuli on the ECM generation of human ligament fibroblast (HLF) were assessed. The nanofiber matrix was fabricated using electrospinning technique. To align the nanofibers, a rotating target was used. The HLFs on the aligned nanofibers were spindle-shaped and oriented in the direction of the nanofibers. The degree of ECM production was

Chang Hun Lee; Ho Joon Shin; In Hee Cho; Young-Mi Kang; In Ae Kim; Ki-Dong Park; Jung-Woog Shin

2005-01-01

228

NsdC and NsdD affect Aspergillus flavus morphogenesis and aflatoxin production  

Technology Transfer Automated Retrieval System (TEKTRAN)

The transcription factors NsdC and NsdD have been shown to be necessary for sexual development in Aspergillus nidulans. Herein we examine the role of these proteins in development and aflatoxin production of the agriculturally important, aflatoxin-producing fungus, Aspergillus flavus. We found tha...

229

Chronic cobalt exposure affects antioxidants and ATP production in rat myocardium.  

PubMed

Chronic cobalt exposure is characterized by severe cardiac insufficiency. Since the mechanisms of cobalt toxicity are not yet clear, we analysed the effects of chronic cobalt exposure on antioxidant enzyme activities and myocardial mitochondrial ATP production rate in a rat model. One group of rats was fed a conventional diet and another a cobalt supplemented diet for 24 weeks. The manganese-superoxide dismutase activity was markedly reduced in the cobalt rats (18+/-4.7 U/mg protein) compared to the control rats (100+/-22 U/mg protein; p <0.001). Activity in the respiratory chain enzymes succinate-cytochrome c reductase, NADH-cytochrome c reductase and cytochrome c oxidase was also reduced in the cobalt rats (p<0.01). Glutamate dehydrogenase activity, located in the mitochondrial matrix, was unchanged. The mitochondrial ATP production rate in relation to myocardial mass was lower in the cobalt rats for all substrates tested except palmitoyl-l-carnitine + malate. In conclusion, 24 weeks of chronic cobalt exposure induces a marked decrease in manganese-superoxide dismutase activity, a moderate decrease in mitochondrial ATP production rate and a general reduction in the capacity of the respiratory chain. The impairment in mitochondrial ATP production might be secondary to the decreased manganese-superoxide dismutase activity, causing inactivation of mitochondrial factors susceptible to superoxide radicals. PMID:11768320

Clyne, N; Hofman-Bang, C; Haga, Y; Hatori, N; Marklund, S L; Pehrsson, S K; Wibom, R

2001-01-01

230

COTTON PRODUCTION WITH COVER CROPS: ALDICARB AND NITROGEN AFFECT YIELD AND FIBER PROPERTIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Conservation tillage with cover crops is gaining wide acceptance for cotton (Gossypium hirustum L.) production, but little is known about the effects of habitat manipulation on thrips (Frankliniella sp.) populations and the effects of thrips damage on cotton yield and quality. The objectives of this...

231

Intestinal microbial affects of yeast products on weaned and transport stressed pigs  

Technology Transfer Automated Retrieval System (TEKTRAN)

Study objectives were to determine effects of a commercially available yeast product (XPC, Diamond-V Mills) and stress of transportation on total Enterobacteriaceae, Escherichia coli, coliforms, and Lactobacilli populations in the intestine of weaning pigs. In a RCB design with a 2 x 2 factorial ar...

232

Changes in SAM 2 expression affect lactic acid tolerance and lactic acid production in Saccharomyces cerevisiae.  

PubMed

BackgroundThe great interest in the production of highly pure lactic acid enantiomers comes from the application of polylactic acid (PLA) for the production of biodegradable plastics. Yeasts can be considered as alternative cell factories to lactic acid bacteria for lactic acid production, despite not being natural producers, since they can better tolerate acidic environments. We have previously described metabolically engineered Saccharomyces cerevisiae strains producing high amounts of L-lactic acid (>60 g/L) at low pH. The high product concentration represents the major limiting step of the process, mainly because of its toxic effects. Therefore, our goal was the identification of novel targets for strain improvement possibly involved in the yeast response to lactic acid stress.ResultsThe enzyme S-adenosylmethionine (SAM) synthetase catalyses the only known reaction leading to the biosynthesis of SAM, an important cellular cofactor. SAM is involved in phospholipid biosynthesis and hence in membrane remodelling during acid stress. Since only the enzyme isoform 2 seems to be responsive to membrane related signals (e.g. myo-inositol), Sam2p was tagged with GFP to analyse its abundance and cellular localization under different stress conditions. Western blot analyses showed that lactic acid exposure correlates with an increase in protein levels. The SAM2 gene was then overexpressed and deleted in laboratory strains. Remarkably, in the BY4741 strain its deletion conferred higher resistance to lactic acid, while its overexpression was detrimental. Therefore, SAM2 was deleted in a strain previously engineered and evolved for industrial lactic acid production and tolerance, resulting in higher production.ConclusionsHere we demonstrated that the modulation of SAM2 can have different outcomes, from clear effects to no significant phenotypic responses, upon lactic acid stress in different genetic backgrounds, and that at least in one genetic background SAM2 deletion led to an industrially relevant increase in lactic acid production. Further work is needed to elucidate the molecular basis of these observations, which underline once more that strain robustness relies on complex cellular mechanisms, involving regulatory genes and proteins. Our data confirm cofactor engineering as an important tool for cell factory improvement. PMID:25359316

Dato, Laura; Berterame, Nadia; Ricci, Maria; Paganoni, Paola; Palmieri, Luigi; Porro, Danilo; Branduardi, Paola

2014-10-30

233

Effect of environmental torques on short-term attitude prediction for a rolling-wheel spacecraft in a sun-synchronous orbit  

NASA Technical Reports Server (NTRS)

A numerical evaluation and an analysis of the effects of environmental disturbance torques on the attitude of a hexagonal cylinder rolling wheel spacecraft were performed. The resulting perturbations caused by five such torques were found to be very small and exhibited linearity such that linearized equations of motion yielded accurate results over short periods and the separate perturbations contributed by each torque were additive in the sense of superposition. Linearity of the torque perturbations was not affected by moderate system design changes and persisted for torque-to-angular momentum ratios up to 100 times the nominal expected value. As these conditions include many possible applications, similar linear behavior might be anticipated for other rolling-wheel spacecraft.

Hodge, W. F.

1972-01-01

234

Bone quality assessment for total hip arthroplasty with intraoperative trabecular torque measurements.  

PubMed

BackgroundIn cases of poor bone quality, intraoperative torque measurement might be an alternative to preoperative dual-energy X-ray absorptiometry (DXA) to assess bone quality in total hip arthroplasty (THA).MethodsTrabecular peak torque measurement was applied in 14 paired fresh frozen human femurs. Here, a 6.5¿×¿23 mm wingblade was inserted into the proximal femur without harming the lateral cortical bone. Further tests of the proximal femur also evaluated bone strength (DXA, micro-computed tomography (¿CT), monoaxial compression test), and the results were compared to the trabecular torque measurement. Student¿s t-test was used to compare the values of the groups. Pearson product¿moment was applied to correlate the values of the peak torque measurement with the bone strength measured by DXA, ¿CT, and monoaxial compression test.ResultsIn the femoral head, the mean trabecular peak torque was 4.38¿±¿1.86 Nm. These values showed a strong correlation with the values of the DXA, the ¿CT, and the biomechanical load test (Pearson¿s product¿moment: DXA: 0.86, ¿CT-BMD: 0.80, load test: 0.85). Furthermore, the torque measurement showed a more pronounced correlation with the biomechanical load test compared to the DXA.ConclusionsThe use of this method provides highly diagnostic information about bone quality. Since the approach was adjusted for THA, no harm of the lateral bone stock will result from this measurement during surgery. The results of this initial study employing small sample sizes indicate that this new method is as sensitive as DXA in predicting bone quality and may function as an intraoperative alternative to DXA in THA. Nevertheless, before this method will turn into clinical use, more research and clinical trials are necessary. PMID:25391790

Klotz, Matthias; Beckmann, Nicholas A; Bitsch, Rudi G; Seebach, Elisabeth; Reiner, Tobias; Jäger, Sebastian

2014-11-13

235

Torque ripple in a Darrieus, vertical axis wind turbine  

SciTech Connect

Interaction between a steady wind and a rotating, Darrieus, vertical axis wind turbine produces time periodic aerodynamic loads which cause time dependent torque variations, referred to as torque ripple, to occur in the mechanical link between the turbine and the electrical generator. There is concern for the effect of torque ripple upon fatigue life of drive train components and upon power quality. An analytical solution characterizing the phenomenon of torque ripple has been obtained which is based upon a Fourier expansion of the time dependent features of the problem. Numerical results for torque ripple, some experimental data, determination of acceptable levels and methods of controlling it, are presented and discussed.

Reuter, R.C. Jr.

1980-09-01

236

SCO5745, a Bifunctional RNase J Ortholog, Affects Antibiotic Production in Streptomyces coelicolor  

PubMed Central

The bacterial RNases J are considered bifunctional RNases possessing both endo- and exonucleolytic activities. We have isolated an RNase J ortholog from Streptomyces coelicolor encoded by the gene sco5745. We overexpressed a decahistidine-tagged version of SCO5745 and purified the overexpressed protein by immobilized metal ion affinity chromatography. We demonstrated the presence of both 5?-to-3? exonucleolytic and endonucleolytic activities on the Bacillus subtilis thrS transcript. Exonucleoytic activity predominated with 5? monophosphorylated thrS, while endonucleolytic activity predominated with 5? triphosphorylated thrS. While sco5745 is the only RNase J allele in S. coelicolor, the gene is not essential. Its disruption resulted in delayed production of the antibiotic actinorhodin, overproduction of undecylprodigiosin, and diminished production of the calcium-dependent antibiotic, in comparison with the parental strain. PMID:24415725

Bralley, Patricia; Aseem, Madiha

2014-01-01

237

SCO5745, a bifunctional RNase J ortholog, affects antibiotic production in Streptomyces coelicolor.  

PubMed

The bacterial RNases J are considered bifunctional RNases possessing both endo- and exonucleolytic activities. We have isolated an RNase J ortholog from Streptomyces coelicolor encoded by the gene sco5745. We overexpressed a decahistidine-tagged version of SCO5745 and purified the overexpressed protein by immobilized metal ion affinity chromatography. We demonstrated the presence of both 5'-to-3' exonucleolytic and endonucleolytic activities on the Bacillus subtilis thrS transcript. Exonucleoytic activity predominated with 5' monophosphorylated thrS, while endonucleolytic activity predominated with 5' triphosphorylated thrS. While sco5745 is the only RNase J allele in S. coelicolor, the gene is not essential. Its disruption resulted in delayed production of the antibiotic actinorhodin, overproduction of undecylprodigiosin, and diminished production of the calcium-dependent antibiotic, in comparison with the parental strain. PMID:24415725

Bralley, Patricia; Aseem, Madiha; Jones, George H

2014-03-01

238

Microbiological and physicochemical factors affecting Aspergillus section Flavi incidence in Cavendish banana (Musa cavendishii) chips production in Southern Philippines.  

PubMed

Microbiological and physicochemical factors affecting the incidence of Aspergillus section Flavi in dried Cavendish banana (Musa cavendishii) chips production in Southern Philippines were examined. The average counts of Aspergillus section Flavi (AFC) in fresh and dried Cavendish bananas from 10 production batches of the Philippine Agro-Industrial Development Cooperative in Davao del Norte, Southern Philippines were 1.2 x 10(2) and 1.6 x 10(2) cfu/g, respectively. Isolates from both samples were identified to be Aspergillus flavus based on spore type and conidial structure of isolates. An increasing trend in the AFC of Cavendish bananas was observed during dried banana chips processing. Variability in the AFC between production batches was attributed to differences in aerobic and fungal populations and physicochemical characteristics of the fruits, peel damage of the raw materials, concentration of AFC in the air and food-contact surfaces of the production area, and temperature and relative humidity (RH) conditions of the environment during production and storage. Physicochemical characteristics of Cavendish bananas from the receipt of raw materials up to the first day of drying were within the reported range of values allowing growth and toxin production by aflatoxigenic fungi. Air-borne AFC varied depending on the section of the production area examined. The close proximity of the waste disposal area from the production operation to the preparation, drying and storage areas suggests that cross-contamination, probably air-borne or insect-borne was a likely occurrence. The hands of workers were also identified as AFC sources. Results of this study highlight the need for the development of strategies to control aflatoxigenic fungi and aflatoxin contamination in Philippine dried Cavendish bananas. PMID:15750731

Sales, A C; Azanza, P V; Yoshizawa, T

2005-01-01

239

How do strategic decisions and operative practices affect operating room productivity?  

Microsoft Academic Search

Surgical operating rooms are cost-intensive parts of health service production. Managing operating units efficiently is essential\\u000a when hospitals and healthcare systems aim to maximize health outcomes with limited resources. Previous research about operating\\u000a room management has focused on studying the effect of management practices and decisions on efficiency by utilizing mainly\\u000a modeling approach or before-after analysis in single hospital case.

Antti Peltokorpi

2011-01-01

240

Factors affecting the cooking and extrusion properties of sorghum for noodle production  

E-print Network

, due to the high cost of rice flour, some companies in the Phillipines have resorted to using corn and cassava in noodle production (Umali 1981) . Starch Properties Cereal grains store energy in the form of starch. Starch is found in the form... third after rice and wheat as a cereal for human consumption (Pushpamma 1990). and Asia, almost all the sorghum grain is In Africa for human consumption, The stalks, leaves, and roots are mainly used for livestock feed, building materials...

Lekalake, Rosemary Ikalafeng

2012-06-07

241

Volatile production by ‘Golden Delicious’ apples is affected by preharvest application of aminoethoxyvinylglycine  

Microsoft Academic Search

The effect of AVG application on the quality and volatile production of ‘Golden Delicious’ apples, grown in Chihuahua Mexico, was evaluated. AVG (125gAVG\\/ha) was applied on apple trees four weeks before harvesting. Apples were harvested 176 days after full bloom and stored at 8°C for 35d. Quality parameters and volatile compounds were periodically evaluated. AVG application retarded color changes, and

N. A. Salas; F. J. Molina-Corral; G. A. González-Aguilar; A. Otero; D. R. Sepulveda; G. I. Olivas

2011-01-01

242

FOLIAR BORON ENHANCES LEAF CHLOROSIS AND DOES NOT AFFECT PECAN PRODUCTION AND NUT QUALITY  

Microsoft Academic Search

The narrow range between boron (B) deficiency and toxicity compared with other micronutrients is a serious problem for sustainable production of pecan throughout the southwest United States of America. However, performance of pecan under foliar B is lacking. Five B treatments (0, 0.5, 1.0, 1.5 kg B ha, water spray) were applied to 27 years old trees of pecan variety

Shad Khan Khalil; John Mexal; Abdur Rehman; Amanullah; Fida Muhammad; Amir Zaman Khan

2011-01-01

243

Thermal stress and tropical cyclones affect economic production in Central America and Caribbean  

NASA Astrophysics Data System (ADS)

Surface temperatures and tropical cyclones have large impacts on economic production. Local cyclone energy dissipation reduces output in agriculture and tourism, while stimulating output in construction. High surface temperatures reduce output in several labor-intensive industries; a 1° C increase for two consecutive years results in production losses of ˜13%. The response is greatest during the hottest season and is non-linear, with high temperature days contributing the most to production losses. The structure of this response matches results from a large ergonomics literature, supporting the hypothesis that thermal stress reduces human performance, driving macroeconomic fluctuations. This large response of non-agricultural sectors suggests that current estimates underestimate the scale and scope of economic vulnerabilities to climate change. Responses of each industry to surface temperature, tropical cyclones and rainfall. Estimates represent the change of value-added in the industry in response to each atmospheric variables during the year of production (L=0) and the years prior (L?1). The responses to surface temperature are triangles, tropical cyclones are squares and rainfall are crosses. Estimates are grey if none of the annual responses are significant at the ? = 0.1 level. Whiskers indicate 95% confidence intervals. Tourism receipts displays the five years prior (L=1-5) because of the long response of that industry to cyclones. Agriculture per worker is also plotted as circles when estimated a second time excluding mainland countries from the sample. Units are: temperature- percent change in output per 0.33°C; cyclones- percent changes in output per 1 standard deviation of tropical cyclone energy; rainfall- percent change in output per 2 cm/month.

Hsiang, S. M.

2009-12-01

244

Biomass production and nutrient removal by Chlorella sp. as affected by sludge liquor concentration.  

PubMed

The use of microalgae for biomass production and nutrient removal from the reject water produced in the dewatering process of anaerobically digested sludge, sludge liquor, was investigated. The sludge liquor was characterized by a high content of total suspended solids (1590 mg L(-1)), a high nitrogen concentration (1210 mg L(-1)), and a low phosphorus concentration (28 mg L(-1)). Chlorella sp. was grown in sludge liquor diluted with wastewater treatment plant effluent water to different concentrations (12, 25, 40, 50, 70, and 100%) using batch mode. The environmental conditions were 25 °C, a continuous lightning of 115 ?mol m(-2) s(-1), and a CO2 concentration of 3.0%. The highest biomass production (0.42-0.45 g dry weight L(-1) Day(-1)) was achieved at 40-50% sludge liquor, which was comparable to the production of the control culture grown with an artificial fertilizer. The biomass production was 0.12 and 0.26 g dry weight L(-1) Day(-1) at 12% and 100% sludge liquor, respectively. The percentage of nitrogen in the algal biomass increased from 3.6% in 12% sludge liquor and reached a saturation of ?10% in concentrations with 50% sludge liquor and higher. The phosphorus content in the biomass increased linearly from 0.2 to 1.5% with increasing sludge liquor concentrations. The highest nitrogen removal rates by algal biosynthesis were 33.6-42.6 mg TN L(-1) Day(-1) at 40-70% sludge liquor, while the highest phosphorus removal rates were 3.1-4.1 mg TP L(-1) Day(-1) at 50-100% sludge liquor. PMID:24935023

Åkerström, Anette M; Mortensen, Leiv M; Rusten, Bjørn; Gislerød, Hans Ragnar

2014-11-01

245

Environmental conditions affecting exopolysaccharide production by Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp  

Microsoft Academic Search

Three different chromium-resistant microorganisms (Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.) were tested with regard to their EPS production at different pH levels, temperatures, Cr(VI) concentrations, and incubation periods. The optimum pH level was 7 for P. aeruginosa and Micrococcus sp., while it was 8 for Ochrobactrum sp. according to the highest EPS amount at 100mg\\/L Cr(VI) concentration. The highest

Nur Koçberber K?l?ç; Gönül Dönmez

2008-01-01

246

Torque generated by the flagellar motor of Escherichia coli.  

PubMed Central

Cells of the bacterium Escherichia coli were tethered and spun in a high-frequency rotating electric field at a series of discrete field strengths. This was done first at low field strengths, then at field strengths generating speeds high enough to disrupt motor function, and finally at low field strengths. Comparison of the initial and final speed versus applied-torque plots yielded relative motor torque. For backward rotation, motor torque rose steeply at speeds close to zero, peaking, on average, at about 2.2 times the stall torque. For forward rotation, motor torque remained approximately constant up to speeds of about 60% of the zero-torque speed. Then the torque dropped linearly with speed, crossed zero, and reached a minimum, on average, at about -1.7 times the stall torque. The zero-torque speed increased with temperature (about 90 Hz at 11 degrees C, 140 Hz at 16 degrees C, and 290 Hz at 23 degrees C), while other parameters remained approximately constant. Sometimes the motor slipped at either extreme (delivered constant torque over a range of speeds), but eventually it broke. Similar results were obtained whether motors broke catastrophically (suddenly and completely) or progressively or were de-energized by brief treatment with an uncoupler. These results are consistent with a tightly coupled ratchet mechanism, provided that elastic deformation of force-generating elements is limited by a stop and that mechanical components yield at high applied torques. PMID:8298044

Berg, H C; Turner, L

1993-01-01

247

Mutations Affecting Hyphal Colonization and Pyoverdine Production in Pseudomonads Antagonistic toward Phytophthora parasitica  

PubMed Central

In previous studies, Pseudomonas putida 06909 and Pseudomonas fluorescens 09906 suppressed populations of Phytophthora parasitica in the citrus rhizosphere, suggesting that these bacteria may be useful in biological control of citrus root rot. In this study we investigated the mechanisms of antagonism between the bacteria and the fungus. Both bacteria colonized Phytophthora hyphae and inhibited the fungus on agar media. A hyphal column assay was developed to measure the colonization of bacteria on fungal hyphae and to enrich for colonization-deficient mutants. In this way we identified Tn5 mutants of each pseudomonad that were not able to colonize the hyphae and inhibit fungal growth in vitro. Colonization-deficient mutants were nonmotile and lacked flagella. Survival of nonmotile mutants in a citrus soil was similar to survival of a random Tn5 mutant over a 52-day period. Additional screening of random Tn5 mutants of both pseudomonads for loss of fungal inhibition in vitro yielded two distinct types of mutants. Mutants of the first type were deficient in production of pyoverdines and in inhibition of the fungus in vitro, although they still colonized fungal hyphae. Mutants of the second type lacked flagella and were not able to colonize the hyphae or inhibit fungal growth. No role was found for antibiotic production by the two bacteria in the inhibition of the fungus. Our results suggest that both hyphal colonization and pyoverdine production are important in the inhibition of Phytophthora parasitica by P. fluorescens and P. putida in vitro. Images PMID:16349177

Yang, Ching-Hong; Menge, John A.; Cooksey, Donald A.

1994-01-01

248

Blockage of the pyrimidine biosynthetic pathway affects riboflavin production in Ashbya gossypii.  

PubMed

The Ashbya gossypii riboflavin biosynthetic pathway and its connection with the purine pathway have been well studied. However, the outcome of genetic alterations in the pyrimidine pathway on riboflavin production by A. gossypii had not yet been assessed. Here, we report that the blockage of the de novo pyrimidine biosynthetic pathway in the recently generated A. gossypii Agura3 uridine/uracil auxotrophic strain led to improved riboflavin production on standard agar-solidified complex medium. When extra uridine/uracil was supplied, the production of riboflavin by this auxotroph was repressed. High concentrations of uracil hampered this (and the parent) strain growth, whereas excess uridine favored the A. gossypii Agura3 growth. Considering that the riboflavin and the pyrimidine pathways share the same precursors and that riboflavin overproduction may be triggered by nutritional stress, we suggest that overproduction of riboflavin by the A. gossypii Agura3 may occur as an outcome of a nutritional stress response and/or of an increased availability in precursors for riboflavin biosynthesis, due to their reduced consumption by the pyrimidine pathway. PMID:25444878

Silva, Rui; Aguiar, Tatiana Q; Domingues, Lucília

2015-01-10

249

Displaceable Spur Gear Torque Controlled Driver and Method  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a torque driver including a laterally displaceable gear support member to carry an output spur gear. A biasing assembly biases the output spur gear into engagement with a pinion to which is applied an input torque greater than a desired output torque limit for a threaded fastener such as a nut or screw. A coiled output linkage connects the output spur gear with a fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. A gauged selector mechanism is provided to laterally displace multiple driven members for fasteners arranged in differing configurations. The torque limit is selectably adjustable and may be different for fasteners within the same fastener configuration.

Cook, Joseph S., Jr. (Inventor)

1996-01-01

250

Displaceable spur gear torque controlled driver and method  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a torque driver including a laterally displaceable gear support member to carry an output spur gear. A biasing assembly biases the output spur gear into engagement with a pinion to which is applied an input torque greater than a desired output torque limit for a threaded fastener such as a nut or screw. A coiled output linkage connects the output spur gear with a fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. A gauged selector mechanism is provided to laterally displace multiple driver members for fasteners arranged in differing configurations. The torque limit is selectably adjustable and may be different for fasteners within the same fastener configuration.

Cook, Joseph S., Jr. (inventor)

1994-01-01

251

Nugget formation reservoir characteristics affecting production in the Overthrust Belt of Southwestern Wyoming  

SciTech Connect

The Jurassic-Triassic age Nugget sandstone of the southwestern Wyoming Overthrust Belt is a texturally heterogeneous reservoir with anisotropic directional properties which have been inherited from the depositional environment, modified by diagenesis, and finally overprinted by tectonism. Predominantly eolian processes deposited crossbedded and horizontally-bedded, very fine-grained to coarse-grained sand in dunes, interdunes and associated environments. Original reservoir quality has been somewhat modified by compaction, cementation, dissolution, clay mineralization, and precipitation of hydrocarbon resins. Low-permeability, gougefilled and carbonate-filled fractures potentially restrict hydrocarbon distribution and affect producibility; whereas discontinuous, open fractures enhance permeability in some intervals. Contrast in permeability between dune and interdune intervals ranges over four to five orders of magnitude. Dune and interdune deposits are locally correlatable with the aid of core, conventional log, and stratigraphic dipmeter data. Stratigraphic correlations can then be utilized to model the lateral and vertical extent of directional properties in the reservoir.

Lindquist, S.J.

1982-09-01

252

Identification of significant medium components that affect docosahexaenoic acid production by Schizochytrium sp. SW1  

NASA Astrophysics Data System (ADS)

Central composite design (CCD) was employed to investigate the significance of glucose, yeast extract, MSG and sea salt in affecting the amount of docosahexaenoic acid (DHA) accumulated by a locally isolated strain of Schizochytrium. Design Expert software was used to construct a set of experiments where each medium component mentioned above was varied over three levels. Cultivation was carried out in 250mL flasks containing 50mL of medium, incubated at 30°C with 200 rpm agitation for 96 hours. ANOVA was conducted to identify the influential factors and the level of their significance where factors that scored a probability value of less than 0.05 were considered significant. The level of influence for each independent variable was also interpreted using perturbation whereas pattern of interaction between the factors were interpreted using interaction plots. This experiment revealed that yeast extract and monosodium glutamate have significant influence on DHA accumulation process by Schizochytrium sp. SW1.

Manikan, Vidyah; Hamid, Aidil A.

2013-11-01

253

Six component robotic force-torque sensor  

NASA Technical Reports Server (NTRS)

The results of a two-phase contract studying the feasibility of a miniaturized six component force-torque sensor and development of a working laboratory system were described. The principle of operation is based upon using ultrasonic pulse-echo ranging to determine the position of ultrasonic reflectors attached to a metal or ceramic cover plate. Because of the small size of the sensor, this technology may have application in robotics, to sense forces and torques at the finger tip of a robotic end effector. Descriptions are included of laboratory experiments evaluating materials and techniques for sensor fabrication and of the development of support electronics for data acquisition, computer interface, and operator display.

Grahn, Allen R.; Hutchings, Brad L.; Johnston, David R.; Parsons, David C.; Wyatt, Roland F.

1987-01-01

254

Left-handed optical radiation torque  

NASA Astrophysics Data System (ADS)

Optical forces and torques are two mechanical degrees of freedom available to manipulate matter, and form the basis of optical tweezing strategies. In contrast to the Keplerian intuition that objects should be pushed downstream an incident photon flux, the concept of `negative' optical forces has recently been described and has triggered many developments. Here, we report on the counterintuitive angular analogue of negative optical forces by demonstrating that circularly polarized Gaussian light beams give rise to torque with opposite sign to that of the incident optical angular momentum. Such a `left-handed' mechanical effect is demonstrated by the use of an inhomogeneous and anisotropic transparent macroscopic medium. Practical difficulties associated with the direct observation of optically induced spinning of a macroscopic object are circumvented via the rotational Doppler effect. These results shed light on spin-orbit optomechanics and equip the left-handed optomechanical toolbox with angular features.

Hakobyan, Davit; Brasselet, Etienne

2014-08-01

255

Nutrient availability affects pigment production but not growth in lichens of??biological soil crusts  

USGS Publications Warehouse

Recent research suggests that micronutrients such as Mn may limit growth of slow-growing biological soil crusts (BSCs) in some of the drylands of the world. These soil surface communities contribute strongly to arid ecosystem function and are easily degraded, creating a need for new restoration tools. The possibility that Mn fertilization could be used as a restoration tool for BSCs has not been tested previously. We used microcosms in a controlled greenhouse setting to investigate the hypothesis that Mn may limit photosynthesis and consequently growth in Collema tenax, a dominant N-fixing lichen found in BSCs worldwide. We found no evidence to support our hypothesis; furthermore, addition of other nutrients (primarily P, K, and Zn) had a suppressive effect on gross photosynthesis (P = 0.05). We also monitored the growth and physiological status of our microcosms and found that other nutrients increased the production of scytonemin, an important sunscreen pigment, but only when not added with Mn (P = 0.01). A structural equation model indicated that this effect was independent of any photosynthesis-related variable. We propose two alternative hypotheses to account for this pattern: (1) Mn suppresses processes needed to produce scytonemin; and (2) Mn is required to suppress scytonemin production at low light, when it is an unnecessary photosynthate sink. Although Mn fertilization does not appear likely to increase photosynthesis or growth of Collema, it could have a role in survivorship during environmentally stressful periods due to modification of scytonemin production. Thus, Mn enrichment should be studied further for its potential to facilitate BSC rehabilitation. ?? 2008 Elsevier Ltd.

Bowker, M.A.; Koch, G.W.; Belnap, J.; Johnson, N.C.

2008-01-01

256

Medium-Chain Fatty Acids Affect Citrinin Production in the Filamentous Fungus Monascus ruber  

PubMed Central

During submerged culture in the presence of glucose and glutamate, the filamentous fungus Monascus ruber produces water-soluble red pigments together with citrinin, a mycotoxin with nephrotoxic and hepatoxic effects on animals. Analysis of the 13C-pigment molecules from mycelia cultivated with [1-13C]-, [2-13C]-, or [1,2-13C]acetate by 13C nuclear magnetic resonance indicated that the biosynthesis of the red pigments used both the polyketide pathway, to generate the chromophore structure, and the fatty acid synthesis pathway, to produce a medium-chain fatty acid (octanoic acid) which was then bound to the chromophore by a trans-esterification reaction. Hence, to enhance pigment production, we tried to short-circuit the de novo synthesis of medium-chain fatty acids by adding them to the culture broth. Of fatty acids with carbon chains ranging from 6 to 18 carbon atoms, only octanoic acid showed a 30 to 50% stimulation of red pigment production, by a mechanism which, in contrast to expectation, did not involve its direct trans-esterification on the chromophore backbone. However, the medium- and long-chain fatty acids tested were readily assimilated by the fungus, and in the case of fatty acids ranging from 8 to 12 carbon atoms, 30 to 40% of their initial amount transiently accumulated in the growth medium in the form of the corresponding methylketone 1 carbon unit shorter. Very interestingly, these fatty acids or their corresponding methylketones caused a strong reduction in, or even a complete inhibition of, citrinin production by M. ruber when they were added to the medium. Several data indicated that this effect could be due to the degradation of the newly synthesized citrinin (or an intermediate in the citrinin pathway) by hydrogen peroxide resulting from peroxisome proliferation induced by medium-chain fatty acids or methylketones. PMID:10698780

Hajjaj, Hassan; Klaébé, Alain; Goma, Gérard; Blanc, Philippe J.; Barbier, Estelle; François, Jean

2000-01-01

257

Transfer from long to short photoperiods affects production efficiency of day-neutral rice  

NASA Technical Reports Server (NTRS)

The day-neutral, semidwarf rice (Oryza sativa L.) cultivar Ai-Nan-Tsao was grown in a greenhouse under summer conditions using high-pressure sodium lamps to extend the natural photoperiod. After allowing 2 weeks for germination, stand establishment, and thinning to a consistent planting density of 212 plants/m2, stands were maintained under continuous lighting for 35 or 49 days before shifting to 8- or 12-h photoperiods until harvest 76 days after planting. Non-shifted control treatments consisting of 8-, 12-, or 24-h photoperiods also were maintained throughout production. Tiller number increased as duration of exposure to continuous light increased before shifting to shorter photoperiods. However, shoot harvest index and yield efficiency rate were lower for all plants receiving continuous light than for those under the 8- or 12-h photoperiods. Stands receiving 12-h photoperiods throughout production had the highest grain yield per plant and equaled the 8-h-photoperiod control plants for the lowest tiller number per plant. As long as stands were exposed to continuous light, tiller formation continued. Shifting to shorter photoperiods late in the cropping cycle resulted in newly formed tillers that were either sterile or unable to mature grain before harvest. Late-forming tillers also suppressed yield of grain in early-forming tillers, presumably by competing for photosynthate or for remobilized assimilate during senescence. Stands receiving 12-h photoperiods throughout production not only produced the highest grain yield at harvest but had the highest shoot harvest index, which is important for resource-recovery strategies in advanced life-support systems proposed for space.

Goldman, K. R.; Mitchell, C. A.

1999-01-01

258

Do new cellulolytic enzyme preparations affect the industrial strategies for high solids lignocellulosic ethanol production?  

PubMed

Production of ethanol from lignocellulosic materials has a promising market potential, but the process is still only at pilot/demonstration scale due to the technical and economical difficulties of the process. Operating the process at very high solids concentrations (above 20% dry matter-DM) has proven essential for economic feasibility at industrial scale. Historically, simultaneous saccharification and fermentation (SSF) was found to give better ethanol yields compared to separate hydrolysis and fermentation (SHF), but data in literature are typically based on operating the process at low dry matter conditions. In this work the impact of selected enzyme preparation and processing strategy (SHF, presaccharification and simultaneous saccharification and fermentation-PSSF, and SSF) on final ethanol yield and overall performance was investigated with pretreated wheat straw up to 30% DM. The experiments revealed that an SSF strategy was indeed better than SHF when applying an older generation enzyme cocktail (Celluclast-Novozym 188). In case of the newer product Cellic CTec 2, SHF resulted in 20% higher final ethanol yield compared to SSF. It was possible to close the mass balance around cellulose to around 94%, revealing that the most relevant products could be accounted for. One observation was the presence of oxidized sugar (gluconic acid) upon enzymatic hydrolysis with the latest enzyme preparation. Experiments showed gluconic acid formation by recently discovered enzymatic class of lytic polysaccharides monoxygenases (LPMO's) to be depending on the processing strategy. The lowest concentration was achieved in SSF, which could be correlated with less available oxygen due to simultaneous oxygen consumption by the yeast. Quantity of glycerol and cell mass was also depending on the selected processing strategy. PMID:24022674

Cannella, David; Jørgensen, Henning

2014-01-01

259

Infectivity and egg production of Nematospiroides dubius as affected by space flight and ultraviolet irradiation  

NASA Technical Reports Server (NTRS)

Nematospiroides dubius was tested to determine the infective potential of the third stage larvae and the egg-production and egg-viability rates of the resulting adults after they are exposed to space flight and solar ultraviolet irradiation. The results are indicative that space-flown larvae exposed to solar ultraviolet irradiation were rendered noninfective in C57 mice, whereas flight control larvae that received no solar ultraviolet irradiation matured at the same rate as the ground control larvae. However, depressed egg viability was evident in the flight control larvae.

Long, R. A.; Ellis, W. L.; Taylor, G. R.

1973-01-01

260

Factors affecting catalysis of copper corrosion products in NDMA formation from DMA in simulated premise plumbing.  

PubMed

This study investigated the effects of corrosion products of copper, a metal commonly employed in household plumbing systems, on N-nitrosodimethylamine (NDMA) formation from a known NDMA precursor, dimethylamine (DMA). Copper-catalyzed NDMA formation increased with increasing copper concentrations, DMA concentrations, alkalinity and hardness, but decreased with increasing natural organic matter (NOM) concentration. pH influenced the speciation of chloramine and the interactions of copper with DMA. The transformation of monochloramine (NH2Cl) to dichloramine and complexation of copper with DMA were involved in elevating the formation of NDMA by copper at pH 7.0. The inhibiting effect of NOM on copper catalysis was attributed to the rapid consumption of NH2Cl by NOM and/or the competitive complexation of NOM with copper to limit the formation of DMA-copper complexes. Hardness ions, as represented by Ca(2+), also competed with copper for binding sites on NOM, thereby weakening the inhibitory effect of NOM on NDMA formation. Common copper corrosion products also participated in these reactions but in different ways. Aqueous copper released from malachite [Cu2CO3(OH)2] was shown to promote NDMA formation while NDMA formation decreased in the presence of CuO, most likely due to the adsorption of DMA. PMID:24041569

Zhang, Hong; Andrews, Susan A

2013-11-01

261

Cheese liking and consumer willingness to pay as affected by information about organic production.  

PubMed

The present study aimed to assess the effect of information about organic production on Pecorino cheese liking and consumer willingness to pay. Mean scores of perceived liking were similar for organic cheese (OC) and conventional cheese (CC). Expected liking scores were higher for OC than for CC (P<0.001). For OC the expected liking was significantly higher (P<0.001) than the perceived liking expressed in blind conditions (negative disconfirmation), whereas for CC the expected liking was significantly lower (P<0.001) than the perceived liking expressed in blind conditions (positive disconfirmation). Consumers assimilated their liking for OC in the direction of expectations, as the difference actual vs. perceived liking was significant (P<0.001). However the assimilation was not complete, as also the difference actual liking vs. expected liking was significant (P<0.001). Consumers showed a willingness to pay OC (mean+/-se=4.20+/-0.13 euro/100 g) higher than the local retail price for conventional (1.90 euro/100 g) and even organic cheese (3.00 euro/100 g). We conclude that the information about organic farming can be a major determinant of cheese liking and consumer willingness to pay, thus providing a potential tool for product differentiation, particularly for small scale and traditional farms. PMID:20196900

Napolitano, Fabio; Braghieri, Ada; Piasentier, Edi; Favotto, Saida; Naspetti, Simona; Zanoli, Raffaele

2010-08-01

262

Egg-Laying “Intermorphs” in the Ant Crematogaster smithi neither Affect Sexual Production nor Male Parentage  

PubMed Central

We study male parentage and between-colony variation in sex allocation and sexual production in the desert ant Crematogaster smithi, which usually has only one singly-mated queen per nest. Colonies of this species are known to temporarily store nutrients in the large fat body of intermorphs, a specialized female caste intermediate in morphology between queens and workers. Intermorphs repackage at least part of this fat into consumable but viable male-destined eggs. If these eggs sometimes develop instead of being eaten, intermorphs will be reproductive competitors of the queen but—due to relatedness asymmetries—allies of their sister worker. Using genetic markers we found a considerable proportion of non-queen sons in some, but not all, colonies. Even though intermorphs produce ?1.7× more eggs than workers, their share in the parentage of adult males is estimated to be negligible due to their small number compared to workers. Furthermore, neither colony-level sex allocation nor overall sexual production was correlated with intermorph occurrence or number. We conclude that intermorph-laid eggs typically do not survive and that the storage of nutrients and their redistribution as eggs by intermorphs is effectively altruistic. PMID:24130699

Oettler, Jan; Dijkstra, Michiel B.; Heinze, Jürgen

2013-01-01

263

Interspecific differences in egg production affect egg trace element concentrations after a coal fly ash spill.  

PubMed

In oviparous vertebrates, trace elements transfer from mother to offspring during egg production. For animals that produce eggs slowly, like turtles, the trace element concentration of each egg reflects an integration of dietary and stored accumulation over the duration of vitellogenesis. Because turtles also produce eggs synchronously, all eggs within a clutch should exhibit uniform trace element concentrations. In contrast, for animals that produce eggs in sequence and primarily from current dietary resources, like many birds, the trace element concentrations of eggs should be less uniform within a clutch, and likely reflect short-term changes in dietary exposure. We tested the hypothesis that stinkpot turtle (Sternotherus odoratus) clutches exhibit lower variability and higher repeatability in barium, selenium, strontium, and thallium concentrations than those of tree swallows (Tachycineta bicolor) from a site impacted by a recent coal ash spill. All four trace elements exhibited significantly lower variability and significantly higher repeatability in stinkpot clutches than in swallow clutches. Mean trace element concentrations of stinkpot eggs were also significantly higher than those of swallow eggs although both species feed primarily on aquatic invertebrates. Variability in swallow egg trace element concentrations was partially due to significant laying order effects. Our results support the hypothesis that interspecific variation in the source of resources and in the synchronicity and rate of egg production can lead to interspecific differences in the variability of egg trace element concentrations. PMID:24180645

Van Dyke, James U; Beck, Michelle L; Jackson, Brian P; Hopkins, William A

2013-12-01

264

Dynamics of a split torque helicopter transmission  

NASA Technical Reports Server (NTRS)

A high reduction ratio split torque gear train has been proposed as an alternative to a planetary configuration for the final stage of a helicopter transmission. A split torque design allows a high ratio of power-to-weight for the transmission. The design studied in this work includes a pivoting beam that acts to balance thrust loads produced by the helical gear meshes in each of two parallel power paths. When the thrust loads are balanced, the torque is split evenly. A mathematical model was developed to study the dynamics of the system. The effects of time varying gear mesh stiffness, static transmission errors, and flexible bearing supports are included in the model. The model was demonstrated with a test case. Results show that although the gearbox has a symmetric configuration, the simulated dynamic behavior of the first and second compound gears are not the same. Also, results show that shaft location and mesh stiffness tuning are significant design parameters that influence the motions of the system.

Rashidi, Majid; Krantz, Timothy

1992-01-01

265

Dynamics of a split torque helicopter transmission  

NASA Astrophysics Data System (ADS)

A high reduction ratio split torque gear train has been proposed as an alternative to a planetary configuration for the final stage of a helicopter transmission. A split torque design allows a high ratio of power-to-weight for the transmission. The design studied in this work includes a pivoting beam that acts to balance thrust loads produced by the helical gear meshes in each of two parallel power paths. When the thrust loads are balanced, the torque is split evenly. A mathematical model was developed to study the dynamics of the system. The effects of time varying gear mesh stiffness, static transmission errors, and flexible bearing supports are included in the model. The model was demonstrated with a test case. Results show that although the gearbox has a symmetric configuration, the simulated dynamic behavior of the first and second compound gears are not the same. Also, results show that shaft location and mesh stiffness tuning are significant design parameters that influence the motions of the system.

Rashidi, Majid; Krantz, Timothy

266

Dietary fat affects heat production and other variables of equine performance, under hot and humid conditions.  

PubMed

Does dietary fat supplementation during conditioning improve athletic performance, especially in the heat? Fat adaptation has been used to increase energy density, decrease bowel bulk and faecal output and reduce health risks associated with hydrolysable carbohydrate overload. It may also reduce spontaneous activity and reactivity (excitability), increase fatty acid oxidation, reduce CO2 production and associated acidosis, enhance metabolic regulation of glycolysis, improve both aerobic and anaerobic performance and substantially reduce heat production. A thermochemical analysis of ATP generation showed the least heat release during the direct oxidation of long chain fatty acids, which have a 3% advantage over glucose and 20 to 30% over short chain fatty acids and amino acids. Indirect oxidation via storage as triglyceride increased heat loss during ATP generation by 3% for stearic acid, 65% for glucose and 174% for acetic acid. Meal feeding and nutrient storage, therefore, accentuates the advantage of dietary fat. A calorimetric model was based on initial estimates of net energy for competitive work (10.76 MJ for the Endurance Test of an Olympic level 3-day-event), other work (14.4 MJ/day) and maintenance (36 MJ), then applied estimates of efficiencies to derive associated heat productions for the utilisation of 3 diets, Diet A: hay (100), Diet B: hay and oats (50:50) and Diet C: hay, oats and vegetable oil (45:45:10), the difference between the last 2 diets representing fat adaptation. During a 90.5 min speed and stamina test, heat production was estimated as 37, 35.4 and 34.6 MJ for the 3 diets, respectively, an advantage 0.8 MJ less heat load for the fat adapted horse, which would reduce water needed for evaporation by 0.33 kg and reduce body temperature increase by about 0.07 degree C. Total estimated daily heat production was 105, 93 and 88 MJ for the 3 diets, respectively, suggesting a 5 MJ advantage for the fat adapted horse (Diet C vs. Diet B). Estimated intake energy was 348, 269 and 239 MJ for the 3 diets, respectively, and corresponding daily intakes as fed were 22.2, 16.6 and 12.9 kg, an advantage of 3.7 kg for the fat adapted horse. Water requirement was estimated to decrease by about 6 kg/day in the fat adapted horse: 4 kg less faecal water output and 2 kg less water for evaporation. This model indicated that the fat supplemented diet reduced daily heat load by 5%, feed intake by 22%, faecal output (and bowel ballast) by 31% and water requirement by 12%. The advantage of fat supplementation over hay and oats was in general about half that gained by hay and oats over hay alone. PMID:8894547

Kronfeld, D S

1996-07-01

267

Nugget formation reservoir characteristics affecting production in the overthrust belt of southwestern Wyoming  

SciTech Connect

The Jurassic/Triassic Age Nugget sandstone of the southwestern Wyoming overthrust belt is a texturally heterogeneous reservoir with anisotropic properties that have been inherited primarily from the depositional environment but also have been modified by diagenesis and overprinted by tectonism. Predominantly Eolian processes deposited crossbedded, low-angle to horizontally bedded and rippled, very-fine- to coarse-grained sand in dunes, interdune areas, and associated environments. Original reservoir quality has been somewhat modified by compaction, cementation, dissolution, clay mineralization, and the precipitation or emplacement of hydrocarbon asphaltenes or residues. Low-permeability gouge- and carbonate-filled fractures potentially restrict hydrocarbon distribution and negatively affect producibility, whereas discontinuous open fractures enhance permeability in some intervals. Contrast in air permeability between dune and interdune deposits ranges over four to five orders of magnitude. Dune and interdune intervals are correlatable locally with the aid of core log, conventional log, and stratigraphic dipmeter data. Stratigraphic correlations then can be utilized to model the lateral and vertical extent of directional properties in the reservoir.

Lindquist, S.J.

1983-07-01

268

Investigation of the factors affecting adult fly production in biosolid cake.  

PubMed

The seasonal pattern of adult fly production in both fresh and aged biosolid cake was established by the exposure of biosolid cake to natural conditions in the central coastal region of Perth, Western Australia, over the course of a year. Relationships between fly emergence and six factors (weeks exposed, pH, NH(4), rainfall, temperature, and moisture) suspected of facilitating the attraction of adult flies to biosolid cake were measured. The aim was to study the production of adult flies with regard to weeks exposed in different seasons to establish a "best practice" storage procedure for aged biosolid cake. Four fly species were collected during the study; Musca domestica L. (house fly), Stomoxys calcitrans L. (stable fly), Fannia canicularis L. (lesser house fly), and Muscina stabulans (Fallén) (false stable fly). Of the 5,303 flies identified, >97% of these were either M. domestica or S. calcitrans. Adult flies emerged from biosolid cake all year round with a sharp decline in winter. The number of emerged flies peaked in summer (3,163 flies) and declined during autumn (1,545 flies) and spring (532 flies). Significant positive relationships were observed between the number of adult flies emerging from biosolid cake and ambient temperature, NH(4) content, and weeks exposed. Higher ambient temperatures and a higher NH(4) content of the biosolid cake were associated with increased number of adult flies emerging from the biosolid cake. Similarly, the majority of flies emerged from biosolid cake in the first 10 wk of exposure to fly activity. PMID:19508771

Dadour, Ian R; Voss, Sasha C

2009-06-01

269

Blastocyst rate of in vitro embryo production in sheep is affected by season.  

PubMed

It has been reported that the number and quality of in vitro produced embryos is season related. This study was conducted to assess the effect of season on cleavage, blastocyst and lambing rates of in vitro produced ovine embryos during 3 years of collection data. Ovaries of Sarda sheep were collected from a slaughterhouse. In total, 5035 oocytes were recovered and matured in TCM-199 with 4 mg/ml bovine serum albumin (BSA), 100 ?M cysteamine, 0.3 mM Na pyruvate, 0.1 UI/ml recombinant follicle-stimulating hormone (r-FSH), 0.1 UI/ml recombinant luteinising hormone (r-LH), and 1 ?g/ml estradiol-17?. Matured oocytes were fertilized with fresh semen in synthetic oviductal fluid (SOF) with 20% heat inactivated estrous sheep serum. The presumptive zygotes were cultured for 6-7 days (blastocyst stage) in SOF medium supplemented with 1% Basel Medium Eagle (BME), 1% Minimum Essential Medium, 1 mM glutamine and 8 mg/ml fatty acid-free BSA. The embryos produced were vitrified and a total of 165 blastocysts (80 from the breeding season and 85 from the anoestrous season) were transferred in pairs into recipient ewes during the reproductive period. There were no significant differences in cleavage rates between seasons in any of the 3 years examined (84% versus 83%, 81% versus 80% and 80% versus 79%, respectively). The blastocyst rate varied significantly between seasons in 2005 and 2007 (P < 0.05), and in 2006 (P < 0.001). There were no differences in pregnancy and lambing rates between embryos during anoestrous versus during the breeding season. In conclusion, only the blastocyst rate appeared to have been affected by season, possibly due to variation in the number of developmentally competent oocytes. PMID:23458093

Mara, L; Sanna, D; Casu, S; Dattena, M; Muñoz, I M Mayorga

2014-08-01

270

Bacillus cereus and Bacillus thuringiensis spores in Korean rice: prevalence and toxin production as affected by production area and degree of milling.  

PubMed

We determined the prevalence of and toxin production by Bacillus cereus and Bacillus thuringiensis in Korean rice as affected by production area and degree of milling. Rough rice was collected from 64 farms in 22 agricultural areas and polished to produce brown and white rice. In total, rice samples were broadly contaminated with B. cereus spores, with no effect of production area. The prevalence and counts of B. cereus spores declined as milling progressed. Frequencies of hemolysin BL (HBL) production by isolates were significantly (P ? 0.01) reduced as milling progressed. This pattern corresponded with the presence of genes encoding the diarrheal enterotoxins. The frequency of B. cereus isolates positive for hblC, hblD, or nheB genes decreased as milling progressed. Because most B. cereus isolates from rice samples contained six enterotoxin genes, we concluded that B. cereus in rice produced in Korea is predominantly of the diarrheagenic type. The prevalence of B. thuringiensis in rice was significantly lower than that of B. cereus and not correlated with production area. All B. thuringiensis isolates were of the diarrheagenic type. This study provides information useful for predicting safety risks associated with B. cereus and B. thuringiensis in rough and processed Korean rice. PMID:24929722

Kim, Booyoung; Bang, Jihyun; Kim, Hoikyung; Kim, Yoonsook; Kim, Byeong-Sam; Beuchat, Larry R; Ryu, Jee-Hoon

2014-09-01

271

Factors Affecting Process Temperature and Biogas Production in Small-scale Rural Biogas Digesters in Winter in Northern Vietnam.  

PubMed

This study investigated the main factors influencing digester temperature and methods to reduce heat losses during the cold season in the subtropics. Four composite digesters (two insulated and two uninsulated) were buried underground to measure their internal temperature (°C) at a depth of 140 cm and 180 cm, biogas production and methane (CH4) concentration in biogas from August to February. In parallel the temperature of the air (100 cm above ground), in the slurry mixing tank and in the soil (10, 100, 140, and 180 cm depth) was measured by thermocouple. The influent amount was measured daily and the influent chemical composition was measured monthly during the whole experimental period. Seasonal variations in air temperature significantly affected the temperature in the soil, mixing tank and digester. Consequently, biogas production, which is temperature dependent, was influenced by the season. The main factors determining the internal temperature in the digesters were insulation with Styrofoam, air temperature and temperature of slurry in the mixing tank. Biogas production is low due to the cold climate conditions in winter in Northern Vietnam, but the study proved that storing slurry in the mixing tank until its temperature peak at around 14:00 h will increase the temperature in the digester and thus increase potential biogas production. Algorithms are provided linking digester temperature to the temperature of slurry in the mixing tank. PMID:25050049

Pham, C H; Vu, C C; Sommer, S G; Bruun, S

2014-07-01

272

Regional Algal Biofuel Production Potential in the Coterminous United States as Affected by Resource Availability Trade-offs  

SciTech Connect

The warm sunny climate and unoccupied arid lands in the American southwest are favorable factors for algae cultivation. However, additional resources affect the overall viability of specific sites and regions. We investigated the tradeoffs between growth rate, water, and CO2 availability and costs for two strains: N. salina and Chlorella sp. We conducted site selection exercises (~88,000 US sites) to produce 21 billion gallons yr-1 (BGY) of renewable diesel (RD). Experimental trials from the National Alliance for Advanced Biofuels and Bio-Products (NAABB) team informed the growth model of our Biomass Assessment Tool (BAT). We simulated RD production by both lipid extraction and hydrothermal liquefaction. Sites were prioritized by the net value of biofuel minus water and flue gas costs. Water cost models for N. salina were based on seawater and high salinity groundwater and for Chlorella, fresh and brackish groundwater. CO2 costs were based on a flue gas delivery model. Selections constrained by production and water were concentrated along the Gulf of Mexico and southeast Atlantic coasts due to high growth rates and low water costs. Adding flue gas constraints increased the spatial distribution, but the majority of sites remained in the southeast. The 21 BGY target required ~3.8 million hectares of mainly forest (41.3%) and pasture (35.7%). Exclusion in favor of barren and scrub lands forced most production to the southwestern US, but with increased water consumption (5.7 times) and decreased economic efficiency (-38%).

Venteris, Erik R.; Skaggs, Richard; Wigmosta, Mark S.; Coleman, Andre M.

2014-03-15

273

Factors Affecting Process Temperature and Biogas Production in Small-scale Rural Biogas Digesters in Winter in Northern Vietnam  

PubMed Central

This study investigated the main factors influencing digester temperature and methods to reduce heat losses during the cold season in the subtropics. Four composite digesters (two insulated and two uninsulated) were buried underground to measure their internal temperature (°C) at a depth of 140 cm and 180 cm, biogas production and methane (CH4) concentration in biogas from August to February. In parallel the temperature of the air (100 cm above ground), in the slurry mixing tank and in the soil (10, 100, 140, and 180 cm depth) was measured by thermocouple. The influent amount was measured daily and the influent chemical composition was measured monthly during the whole experimental period. Seasonal variations in air temperature significantly affected the temperature in the soil, mixing tank and digester. Consequently, biogas production, which is temperature dependent, was influenced by the season. The main factors determining the internal temperature in the digesters were insulation with Styrofoam, air temperature and temperature of slurry in the mixing tank. Biogas production is low due to the cold climate conditions in winter in Northern Vietnam, but the study proved that storing slurry in the mixing tank until its temperature peak at around 14:00 h will increase the temperature in the digester and thus increase potential biogas production. Algorithms are provided linking digester temperature to the temperature of slurry in the mixing tank. PMID:25050049

Pham, C. H.; Vu, C. C.; Sommer, S. G.; Bruun, S.

2014-01-01

274

Dynamical corotation torques on low-mass planets  

NASA Astrophysics Data System (ADS)

We study torques on migrating low-mass planets in locally isothermal discs. Previous work on low-mass planets generally kept the planet on a fixed orbit, after which the torque on the planet was measured. In addition to these static torques, when the planet is allowed to migrate it experiences dynamical torques, which are proportional to the migration rate and whose sign depends on the background vortensity gradient. We show that in discs a few times more massive than the minimum-mass solar nebula, these dynamical torques can have a profound impact on planet migration. Inward migration can be slowed down significantly, and if static torques lead to outward migration, dynamical torques can take over, taking the planet beyond zero-torque lines set by saturation of the corotation torque in a runaway fashion. This means that the region in non-isothermal discs, where outward migration is possible, can be larger than what would be concluded from static torques alone.

Paardekooper, S.-J.

2014-11-01

275

Bevel gear driver and method having torque limit selection  

NASA Astrophysics Data System (ADS)

This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior torque drivers such as 'click-type' torque wrenches do not actually limit torque application but only provide an audible warning that the limit has been reached.

Cook, Joseph S., Jr.

1994-08-01

276

Bevel gear driver and method having torque limit selection  

NASA Technical Reports Server (NTRS)

This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior torque drivers such as 'click-type' torque wrenches do not actually limit torque application but only provide an audible warning that the limit has been reached.

Cook, Joseph S., Jr. (inventor)

1994-01-01

277

Phenotypic Switching Affecting Chemotaxis, Xanthan Production, and Virulence in Xanthomonas campestris.  

PubMed

The chemotaxis towards sucrose and yeast extract of nine strains of Xanthomonas campestris representing pathovars campestris, armoraciae, translucens, vesicatoria, and pelargonii was analyzed by using swarm plates. Unexpectedly, each of these strains formed small or reduced swarms typical of nonmotile or nonchemotactic bacteria. With time, however, chemotactic cells appeared on the swarm plates as blebs of bacteria. These cells were strongly chemotactic and were concomitantly deficient in exopolysaccharide production. The switch from the wild type (exopolysaccharide producing and nonchemotactic) to the swarmer type (exopolysaccharide deficient and chemotactic) appeared irreversible ex planta in bacteriological medium. However, in radish leaves swarmer-type strains of X. campestris pv. campestris were able to revert to the wild type. Swarmer-type derivatives of two X. campestris pv. campestris wild-type isolates showed reduced virulence and growth in the host plants cauliflower and radish. However, exocellular complementation of X. campestris pv. campestris Hrp (nonpathogenic) mutant was achieved by coinoculation with a swarmer-type strain. PMID:16348384

Kamoun, S; Kado, C I

1990-12-01

278

Torque quality and comparison of internal and external rotor axial flux surface-magnet disc machines  

Microsoft Academic Search

In this paper, pulsating torque components of permanent magnet machines and pulsating torque minimization techniques are discussed for axial flux surface-magnet disc-type PM machines. The pulsating torque analysis describing general instantaneous electromagnetic torque equation and torque ripple factor is briefly provided in order to analyze torque ripple component. Detailed finite-element analyses focusing on the minimization of cogging and torque ripple

Metin Aydin; Surong Huang; Thomas A. Lipo

2006-01-01

279

A geostatistical synthesis study of factors affecting gross primary productivity in various ecosystems of North America  

NASA Astrophysics Data System (ADS)

A coupled Bayesian model selection and geostatistical regression modeling approach is adopted for empirical analysis of gross primary productivity (GPP) at six AmeriFlux sites, including the Kennedy Space Center Scrub Oak, Vaira Ranch, Tonzi Ranch, Blodgett Forest, Morgan Monroe State Forest, and Harvard Forest sites. The analysis is performed at a continuum of temporal scales ranging from daily to monthly, for a period of seven years. A total of 10 covariates representing environmental stimuli and indices of plant physiology are considered in explaining variations in GPP. Similar to other statistical methods, the proposed approach estimates regression coefficients and uncertainties associated with the covariates in a selected regression model. However, unlike traditional regression methods, the presented approach also estimates the uncertainty associated with the selection of a single "best" model of GPP. In addition, the approach provides an enhanced understanding of how the importance of specific covariates changes with temporal resolutions. An examination of trends in the importance of specific covariates reveals scaling thresholds above or below which covariates become significant in explaining GPP. Results indicate that most sites (especially those with a stronger seasonal cycle) exhibit at least one prominent scaling threshold between daily to 20-day temporal scale. This demonstrates that environmental variables that explain GPP at synoptic scales are different from those that capture its seasonality. At shorter time scales, radiation, temperature, and vapor pressure deficit exert most significant influence on GPP at most examined sites. However, at coarser time scales, the importance of these covariates in explaining GPP declines. Overall, unique best models are identified at most sites at the daily scale, whereas multiple competing models are identified at larger time scales. In addition, the selected models are able to explain a larger fraction of the observed variability for sites exhibiting strong seasonality.

Yadav, V.; Mueller, K. L.; Dragoni, D.; Michalak, A. M.

2010-02-01

280

A geostatistical synthesis study of factors affecting gross primary productivity in various ecosystems of North America  

NASA Astrophysics Data System (ADS)

A coupled Bayesian model selection and geostatistical regression modeling approach is adopted for empirical analysis of gross primary productivity (GPP) at six AmeriFlux sites, including the Kennedy Space Center Scrub Oak, Vaira Ranch, Tonzi Ranch, Blodgett Forest, Morgan Monroe State Forest, and Harvard Forest sites. The analysis is performed at a continuum of temporal scales ranging from daily to monthly, for a period of seven years. A total of 10 covariates representing environmental stimuli and indices of plant physiology are considered in explaining variations in GPP. Similarly to other statistical methods, the presented approach estimates regression coefficients and uncertainties associated with the covariates in a selected regression model. Unlike traditional regression methods, however, the approach also estimates the uncertainty associated with the selection of a single "best" model of GPP. In addition, the approach provides an enhanced understanding of how the importance of specific covariates changes with the examined timescale (i.e. temporal resolution). An examination of changes in the importance of specific covariates across timescales reveals thresholds above or below which covariates become important in explaining GPP. Results indicate that most sites (especially those with a stronger seasonal cycle) exhibit at least one prominent scaling threshold between the daily and 20-day temporal scales. This demonstrates that environmental variables that explain GPP at synoptic scales are different from those that capture its seasonality. At shorter time scales, radiation, temperature, and vapor pressure deficit exert the most significant influence on GPP at most examined sites. At coarser time scales, however, the importance of these covariates in explaining GPP declines. Overall, unique best models are identified at most sites at the daily scale, whereas multiple competing models are identified at longer time scales.

Yadav, V.; Mueller, K. L.; Dragoni, D.; Michalak, A. M.

2010-09-01

281

40 CFR Table 11 to Subpart Xxxx of... - Minimum Data for Continuous Compliance With the Emission Limits for Tire Cord Production Affected...  

Code of Federal Regulations, 2010 CFR

...Emission Limits for Tire Cord Production Affected Sources 11 Table 11 to Subpart XXXX of Part 63 Protection of Environment...Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 11 Table 11 to Subpart XXXX of Part 63—Minimum...

2010-07-01

282

Numerical Estimation of Frictional Torques with Rate and State Friction  

E-print Network

In this paper, numerical estimation of frictional torques is carried out of a rotary elastic disc on a hard and rough surface under different rotating conditions. A one dimensional spring- mass rotary system is numerically solved under the quasistatic condition with the rate and state dependent friction model. It is established that torque of frictional strength as well as torque of steady dynamic stress increases with radius and found to be maximum at the periphery of the disc. Torque corresponding to frictional strength estimated using the analytical solution matches closely with the simulation only in the case of high stiffness of the connecting spring. In steady relaxation simulation, a steadily rotating disc is suddenly stopped and relaxational angular velocity and corresponding frictional torque decreases with both steady angular velocity and stiffness of the connecting spring in the velocity strengthening regime. In velocity weakening regime, in contrast, torque of relaxation stress deceases but relaxation velocity increases. The reason for the contradiction is explained.

Arun K. Singh; T. N. Singh

2015-01-20

283

Bevel Gear Driver and Method Having Torque Limit Selection  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a torque driver including an axially displaceable gear with a biasing assembly to bias the displaceable gear into an engagement position. A rotatable cap is provided with a micrometer dial to select a desired output torque. An intermediate bevel gear assembly is disposed between an input gear and an output gear. A gear tooth profile provides a separation force that overcomes the bias to limit torque at a desired torque limit. The torque limit is adjustable and may be adjusted manually or automatically depending on the type of biasing assembly provided. A clutch assembly automatically limits axial force applied to a fastener by the operator to avoid alteration of the desired torque limit.

Cook, Joseph S., Jr. (Inventor)

1997-01-01

284

Torque resolver design for tendon-driven manipulators  

SciTech Connect

Given a set of desired joint torques in an n-DOF tendon-driven manipulator with n + 1 control tendons, the determination of tendon forces is an indeterminate problem. Usually, the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique, an efficient methodology for transforming joint torques (n elements) to motor torques (n + 1 elements) has been developed. This technique called torque resolver'', utilizes two circuit-like operators to transform torques between the two different vector spaces. It can be easily programmed on a digital computer or implemented into an analog-circuit system. It is hoped that this technique will make real-time computed-torque control feasible. The technique has been demonstrated through the dynamic simulation of a three-DOF manipulator.

Lee, J.J.; Tsai, Lung-Wen.

1992-01-01

285

Torque resolver design for tendon-driven manipulators  

SciTech Connect

Given a set of desired joint torques in an n-DOF tendon-driven manipulator with n + 1 control tendons, the determination of tendon forces is an indeterminate problem. Usually, the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique, an efficient methodology for transforming joint torques (n elements) to motor torques (n + 1 elements) has been developed. This technique called ``torque resolver``, utilizes two circuit-like operators to transform torques between the two different vector spaces. It can be easily programmed on a digital computer or implemented into an analog-circuit system. It is hoped that this technique will make real-time computed-torque control feasible. The technique has been demonstrated through the dynamic simulation of a three-DOF manipulator.

Lee, J.J.; Tsai, Lung-Wen

1992-08-01

286

The thermomagnetic torque in nitrogen helium gas mixtures  

E-print Network

TNT. The non-spherical spherical particle interaction was studied by varying the helium concentration in the mixture and measuring the change in the charac- teristic maximum magnetic field-pressure ratio, (-H) and the p max maximum torque t mes... ABSTRACT The Thermomagnetic Torque in Nitrogen Helium Gas Mixtures. (August 1977) Walter Balamy Aschenbeck, Jr. , B. S. , Texas A&N University Chairman of Advisory Committee: Dr. T. W. Adair, III The thermomagnetic torque (TNT) was measured in nitrogen...

Aschenbeck, Walter Balamy

1977-01-01

287

Muscle torque preservation and physical activity in individuals with stroke  

PubMed Central

Background A greater percent loss of concentric versus eccentric muscle torque (i.e., relative eccentric muscle torque preservation) has been reported in the paretic limb of individuals with stroke and has been attributed to hypertonia and/or co-contractions. Stroke provides a unique condition for examining mechanisms underlying eccentric muscle preservation because both limbs experience similar amounts of general physical activity, but the paretic side is impaired directly by the brain lesion. Purpose The purpose of this study was to determine 1) whether eccentric preservation also exists in the nonparetic limb and 2) the relationship of eccentric or concentric torque preservation with physical activity in stroke. We hypothesized that the nonparetic muscles would demonstrate eccentric muscle preservation, which would suggest that non-neural mechanisms may also contribute to its relative preservation. Methods Eighteen stroke and 18 healthy control subjects (age and sex matched) completed a physical activity questionnaire. Maximum voluntary concentric and eccentric joint torques of the ankle, knee and hip flexors and extensors were measured using an isokinetic dynamometer at 30°/s for the paretic and nonparetic muscles. Relative concentric and eccentric peak torque preservation were expressed as a percentage of control subject torque. Results Relative eccentric torque was higher (more preserved) than relative concentric torque for paretic, as well as nonparetic muscles. Physical activity correlated with paretic (r=0.640, p=0.001) and nonparetic concentric torque preservation (r=0.508, p=0.009), but not with eccentric torque preservation for either leg. Conclusions The relative preservation of eccentric torque in the nonparetic muscles suggest a role of non-neural mechanisms and could also explain the preservation observed in other chronic health conditions. Loss of concentric, but not eccentric muscle torque was related to physical inactivity in stroke. PMID:19516167

Eng, Janice J.; Lomaglio, Melanie J.; MacIntyre, Donna L.

2011-01-01

288

Preparation Torque Limit for Composites Joined with Mechanical Fasteners  

NASA Technical Reports Server (NTRS)

Current design guidelines for determining torque ranges for composites are based on tests and analysis from isotropic materials. Properties of composites are not taken into account. No design criteria based upon a systematic analytical and test analyses is available. This paper is to study the maximum torque load a composite component could carry prior to any failure. Specifically, the torque-tension tests are conducted. NDT techniques including acoustic emission, thermography and photomicroscopy are also utilized to characterize the damage modes.

Thomas, Frank P.; Yi, Zhao

2005-01-01

289

Frequency modulation of spin torque oscillator pairs  

NASA Astrophysics Data System (ADS)

The current controlled modulation of nanocontact based spin torque oscillator (STO) pairs is studied in both the synchronized and nonsynchronized states. The synchronized state shows a well behaved modulation and demonstrates robust mutual locking even under strong modulation. The power distribution of the modulation sidebands can be quantitatively described by assuming a single oscillator model. However, in the nonsynchronized state, the modulation sidebands are not well described by the model, indicating interactions between the two individual nanocontact STOs. These findings are promising for potential applications requiring the modulation of large synchronized STO arrays.

Pogoryelov, Ye.; Muduli, P. K.; Bonetti, S.; Iacocca, E.; Mancoff, Fred; Åkerman, Johan

2011-05-01

290

Force and torque smart tensegrity sensor  

NASA Astrophysics Data System (ADS)

Tensegrity structures represent a special class of tendon space structures, whose members may simultaneously perform the functions of strength, sensing, actuating and feedback control. The paper exploits this advantage, proposing a smart tensegrity sensor for simultaneous measurement of six quantities: three orthogonal forces and three orthogonal moments. The paper shows how the static and dynamic characteristics of the device can be calibrated through pretension and damping adjustment. The external forces and torques of interest are estimated using the measurements provided by selected tendons. A state estimator, based on the linearized model, finalizes the design.

Sultan, Cornel; Skelton, Robert T.

1998-07-01

291

Methodology for Determining Limit Torques for Threaded Fasteners  

NASA Technical Reports Server (NTRS)

In aerospace design, where minimizing weight is always a priority, achieving the full capacity from fasteners is essential. To do so, the initial bolt preload must be maximized. The benefits of high preload are well documented and include improved fatigue resistance, a stiffer joint, and resistance to loosening. But many factors like elastic interactions and embedment tend to lower the initial preload placed on the bolt. These factors provide additional motivation to maximize the initial preload. But, to maximize bolt preload, you must determine what torque to apply. Determining this torque is greatly complicated by the large preload scatter generally seen with torque control. This paper presents a detailed methodology for generating limit torques for threaded fasteners. This methodology accounts for the large scatter in preload found with torque control, and therefore, addresses the statistical nature of the problem. It also addresses prevailing torque, a feature common in aerospace fasteners. Although prevailing torque provides a desired locking feature, it can also increase preload scatter. In addition, it can limit the amount of preload that can be generated due to the torsion it creates in the bolt. This paper discusses the complications of prevailing torque and how best to handle it. A wide range of torque-tension bolt testing was conducted in support of this research. The results from this research will benefit the design engineer as well as analyst involved in the design of bolted joints, leading to better, more optimized structural designs.

Hissam, Andy

2011-01-01

292

Note: nonlinear susceptibility from high DC field torque magnetometry.  

PubMed

Torque magnetometry is a convenient technique to measure the magnetic properties of anisotropic materials. Advances in micromachining have made torque magnetometers precise and reliable even in adverse conditions such as very high magnetic fields and very low temperatures. In most applications with such magnetometers the measured torque signals are used to arrive at the linear magnetic susceptibility. In this short note we extend torque magnetometry to measure nonlinear susceptibilities and illustrate our methods with representative data on the heavy fermion compound UPt3. PMID:24784685

Shivaram, B S

2014-04-01

293

Modeling Grain Alignment by Radiative Torques and Hydrogen Formation Torques in Reflection Nebula  

E-print Network

Reflection nebulae--dense cores--illuminated by surrounding stars offer a unique opportunity to directly test our quantitative model of grain alignment based on radiative torques (RATs) and to explore new effects arising from additional torques. In this paper, we first perform detailed modeling of grain alignment by RATs for the IC 63 reflection nebula illuminated both by a nearby $\\gamma$ Cas star and the diffuse interstellar radiation field. We calculate linear polarization $p$ of background stars by radiatively aligned grains and explore the variation of fractional polarization (p/A$_V)$ with visual extinction $A_{V}$ across the cloud. We show that the variation of $p/A_{V}$ from the surface of the dayside toward the IC 63 center can be described by a power law $p/A_{V}\\propto A_{V}^{\\eta}$, having a shallow slope $\\eta \\sim- 0.1$ for $A_{V} 4$. We then consider the effects of additional torques due to H$_{2}$ formation and model grain alignment by joint action of RATs and H$_2$ torques. We find that p/A$_...

Hoang, Thiem; Andersson, B-G

2014-01-01

294

Detection of genetic association and functional polymorphisms of UGDH affecting milk production trait in Chinese Holstein cattle  

PubMed Central

Background We previously localized a quantitative trait locus (QTL) on bovine chromosome 6 affecting milk production traits to a 1.5-Mb region between BMS483 and MNB-209 via genome scanning followed by fine mapping. Results Totally 15 genes were mapped within such linkage region through bioinformatic analysis of the cattle-human comparative map and bovine genome assembly. Of them, the UDP-glucose dehydrogenase (UGDH) was suggested as a potential positional candidate gene for milk production traits based on its corresponding physiological and biochemical functions and genetic effects. By sequencing all the coding exons and the untranslated regions in UGDH with pooled DNA of 8 sires represented the separated families detected in our previous studies, a total of ten SNPs were identified and genotyped in 1417 Holstein cows of 8 separation families. Individual SNP-based association analysis revealed 4 significant associations of SNP Ex1-1, SNP Int3-1, SNP Int5-1, and SNP Ex12-3 with milk yield (P < 0.05), and 2 significant associations of SNP Ex1-1 and SNP Ex12-3 with protein yield (P < 0.05). Furthermore, our haplotype-based association analyses indicated that haplotypes G-C-C, formed by SNP Ex12-2-SNP Int11-1-SNP Ex11-1, T-G, formed by SNP Int9-3-SNP Int9-2, and C-C, formed by SNP Int5-1-SNP Int3-1, are significantly associated with protein percentage (F=4.15; P=0.0418) and fat percentage (F=5.18~7.25; P=0.0072~0.0231). Finally, by using an in vitro expression assay, we demonstrated that the A allele of SNP Ex1-1 and T allele of SNP Ex11-1of UGDH significantly decreases the expression of UGDH by 68.0% at the RNA, and 50.1% at the protein level, suggesting that SNP Ex1-1 and Ex11-1 represent two functional polymorphisms affecting expression of UGDH and may partly contributed to the observed association of the gene with milk production traits in our samples. Conclusions Taken together, our findings strongly indicate that UGDH gene could be involved in genetic variation underlying the QTL for milk production traits. PMID:23122059

2012-01-01

295

Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.  

PubMed

The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. PMID:25481499

Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

2015-03-01

296

Production of bromoform and dibromomethane by Giant Kelp: Factors affecting release and comparison to anthropogenic bromine sources  

USGS Publications Warehouse

Macrocystis pyrifera (Giant Kelp), a dominant macroalgal species in southern California, produced 171 ng per g fresh wt (gfwt) per day of CHBr3 and 48 ng gfwt-1 d-1 of CH2Br2 during laboratory incubations of whole blades. Comparable rates were measured during in situ incubations of intact fronds. Release of CHBr3 and CH2Br2 by M. pyrifera was affected by light and algal photosynthetic activity, suggesting that environmental factors influencing kelp physiology can affect halomethane release to the atmosphere. Data from H2O2 additions suggest that brominated methane production during darkness is limited by bromide oxidant supply. A bromine budget constructed for a region of southern California indicated that bromine emitted from the use of CH3Br as a fumigant (1 x 108 g Br yr-1) dominates macroalgal sources (3 x 106 g Br yr-1). Global projections, however, suggest that combined emissions of marine algae (including microalgae) contribute substantial amounts of bromine to the global cycle, perhaps on the same order of magnitude as anthropogenic sources.

Goodwin, K.D.; North, W.J.; Lidstrom, M.E.

1998-01-01

297

EDITORIAL: Spin-transfer-torque-induced phenomena Spin-transfer-torque-induced phenomena  

NASA Astrophysics Data System (ADS)

This cluster, consisting of five invited articles on spin-transfer torque, offers the very first review covering both magnetization reversal and domain-wall displacement induced by a spin-polarized current. Since the first theoretical proposal on spin-transfer torque—reported by Berger and Slonczewski independently—spin-transfer torque has been experimentally demonstrated in both vertical magnetoresistive nano-pillars and lateral ferromagnetic nano-wires. In the former structures, an electrical current flowing vertically in the nano-pillar exerts spin torque onto the thinner ferromagnetic layer and reverses its magnetization, i.e., current-induced magnetization switching. In the latter structures, an electrical current flowing laterally in the nano-wire exerts torque onto a domain wall and moves its position by rotating local magnetic moments within the wall, i.e., domain wall displacement. Even though both phenomena are induced by spin-transfer torque, each phenomenon has been investigated separately. In order to understand the physical meaning of spin torque in a broader context, this cluster overviews both cases from theoretical modellings to experimental demonstrations. The earlier articles in this cluster focus on current-induced magnetization switching. The magnetization dynamics during the reversal has been calculated by Kim et al using the conventional Landau--Lifshitz-Gilbert (LLG) equation, adding a spin-torque term. This model can explain the dynamics in both spin-valves and magnetic tunnel junctions in a nano-pillar form. This phenomenon has been experimentally measured in these junctions consisting of conventional ferromagnets. In the following experimental part, the nano-pillar junctions with perpendicularly magnetized FePt and half-metallic Heusler alloys are discussed from the viewpoint of efficient magnetization reversal due to a high degree of spin polarization of the current induced by the intrinsic nature of these alloys. Such switching can be further operated at high frequency resulting in an oscillator, as shown in the article by Sulka et al. These results provide fundamental elements for magnetic random access memories. The later articles discuss domain-wall displacement. Again this phenomenon is also described by Shibata et al based on the LLG equation with spin-torque terms. This analytical model can explain the details of the depinning mechanism and a critical current for the displacement. Experimental observation is presented in the subsequent article by Malinowski et al, showing the depinning processes for the cases of intrinsic and extrinsic pinning sites. Here, the detailed magnetic moment configurations within the wall hold the dominant control over the critical current. These results can be used for future 3-dimensional magnetic memories, such as racetrack memory proposed by IBM. We sincerely hope this cluster offers an up-to-date understanding of macroscopic behaviour induced by spin-transfer torque and contributes to further advancement in this exciting research field. We are grateful to all the authors for spending their precious time and knowledge submitting to this cluster. We would also like to thank Professor Kevin O'Grady for his kind offer of the opportunity to make this review accessible to a general audience.

Hirohata, Atsufumi

2011-09-01

298

Research on parallel load sharing principle of piezoelectric six-dimensional heavy force/torque sensor  

NASA Astrophysics Data System (ADS)

In working process of huge heavy-load manipulators, such as the free forging machine, hydraulic die-forging press, forging manipulator, heavy grasping manipulator, large displacement manipulator, measurement of six-dimensional heavy force/torque and real-time force feedback of the operation interface are basis to realize coordinate operation control and force compliance control. It is also an effective way to raise the control accuracy and achieve highly efficient manufacturing. Facing to solve dynamic measurement problem on six-dimensional time-varying heavy load in extremely manufacturing process, the novel principle of parallel load sharing on six-dimensional heavy force/torque is put forward. The measuring principle of six-dimensional force sensor is analyzed, and the spatial model is built and decoupled. The load sharing ratios are analyzed and calculated in vertical and horizontal directions. The mapping relationship between six-dimensional heavy force/torque value to be measured and output force value is built. The finite element model of parallel piezoelectric six-dimensional heavy force/torque sensor is set up, and its static characteristics are analyzed by ANSYS software. The main parameters, which affect load sharing ratio, are analyzed. The experiments for load sharing with different diameters of parallel axis are designed. The results show that the six-dimensional heavy force/torque sensor has good linearity. Non-linearity errors are less than 1%. The parallel axis makes good effect of load sharing. The larger the diameter is, the better the load sharing effect is. The results of experiments are in accordance with the FEM analysis. The sensor has advantages of large measuring range, good linearity, high inherent frequency, and high rigidity. It can be widely used in extreme environments for real-time accurate measurement of six-dimensional time-varying huge loads on manipulators.

Liu, Wei; Li, Ying-jun; Jia, Zhen-yuan; Zhang, Jun; Qian, Min

2011-01-01

299

Factors affecting the formation of disinfection by-products during chlorination and chloramination of secondary effluent for the production of high quality recycled water.  

PubMed

During the production of high quality recycled water by reverse osmosis membrane filtration secondary effluent must be disinfected to limit biofouling on the membrane surface. Advanced Water Treatment Plants in South East Queensland, Australia use disinfectant contact times ranging from 30 min up to 24 h. Disinfectants such as chlorine and chloramines react with effluent organic matter to generate disinfection by-products (DBPs) which could be potentially hazardous to human health if the water is destined for supplementing public water supplies. In this context, secondary effluents are of concern because of their high total organic carbon content which can act as DBP precursors. Also, effluent organic matter may form different DBPs to those formed from natural organic matter during conventional drinking water treatment, either in quantity, identity or simply in the abundance of different DBPs relative to each other. It cannot be assumed per se with certainty that DBP formation will be affected in the same way by operational changes as in drinking water production. Response surface modelling has been employed in this study at the bench scale to investigate the effect of reaction time (0-24 h), pH (5.5-8.5), temperature (23-35 °C), disinfection strategy (chlorine vs chloramines used prior to membrane treatment) and the interaction between these different parameters on DBP formation during disinfection of secondary effluent. The concentration of halogenated DBPs formed during the first 24 h of reaction with the different disinfectants followed the order chlorination > in line-formed monochloramine > pre-formed monochloramine. Contact time with chlorine was the major influencing factor on DBP formation during chlorination, except for the bromine-containing trihalomethanes and dibromoacetonitrile for which pH was more significant. Chlorination at high pH led to an increased formation of chloral hydrate, trichloronitromethane, dibromoacetonitrile and the four trihalomethanes while the opposite effect was observed for the other targeted DBPs. Temperature was identified as the least influencing parameter compared to pH and reaction time for all DBPs in all the disinfection strategies, except for the formation of chloral hydrate where pH and temperature had a similar significance and bromoform that was similarly affected by temperature and reaction time. Chloramines employed at pH 8.5 reduced the concentration of all studied DBPs compared to pH 5.5. Furthermore, reaction time was the most significant factor for trichloronitromethane, chloroform, trichloroacetonitrile, dichloroacetonitrile and bromochloroacetonitrile formation while pH was the most influencing factor affecting the formation of the remaining DBPs. PMID:24095593

Doederer, Katrin; Gernjak, Wolfgang; Weinberg, Howard S; Farré, Maria José

2014-01-01

300

Nonambipolarity, orthogonal conductivity, poloidal flow, and torque  

SciTech Connect

Nonambipolar processes, such as neutral injection onto trapped orbits or ripple-diffusion loss of ..cap alpha..-particles, act to charge a plasma. A current j/sub r/ across magnetic surfaces must arise in the bulk plasma to maintain charge neutrality. An axisymmetric, neoclassical model of the bulk plasma shows that these currents are carried by the ions and exert a j/sub r/B/sub theta/R/c torque in the toroidal direction. A driven poloidal flow V/sub theta/ = E/sub r/'c/B must also develop. The average current density is related to the radial electric field E/sub r/' = E/sub r/ + v/sub /phi//B/sub theta//c in a frame moving with the plasma via the orthogonal conductivity = sigma/sub /perpendicular//E/sub r/', which has the value sigma/sub /perpendicular// = (1.65epsilon/sup 1/2/)(ne/sup 2/..nu../sub ii//M..cap omega../sub theta//sup 2/) in the banana regime. If an ignited plasma loses an appreciable fraction ..delta.. of its thermonuclear ..cap alpha..-particles by banana ripple diffusion, then the torque will spin the plasma to sonic rotation in a time /tau//sub s/ approx. 2/tau//sub E//..delta.., /tau//sub E/ being the energy confinement time. 10 refs., 1 fig.

Hulbert, G.W.; Perkins, F.W.

1989-02-01

301

Dynamics of a split torque helicopter transmission  

NASA Astrophysics Data System (ADS)

Split torque designs, proposed as alternatives to traditional planetary designs for helicopter main rotor transmissions, can save weight and be more reliable than traditional designs. This report presents the results of an analytical study of the system dynamics and performance of a split torque gearbox that uses a balance beam mechanism for load sharing. The Lagrange method was applied to develop a system of equations of motion. The mathematical model includes time-varying gear mesh stiffness, friction, and manufacturing errors. Cornell's method for calculating the stiffness of spur gear teeth was extended and applied to helical gears. The phenomenon of sidebands spaced at shaft frequencies about gear mesh fundamental frequencies was simulated by modeling total composite gear errors as sinusoid functions. Although the gearbox has symmetric geometry, the loads and motions of the two power paths differ. Friction must be considered to properly evaluate the balance beam mechanism. For the design studied, the balance beam is not an effective device for load sharing unless the coefficient of friction is less than 0.003. The complete system stiffness as represented by the stiffness matrix used in this analysis must be considered to precisely determine the optimal tooth indexing position.

Krantz, Timothy L.

1994-06-01

302

Fokker-Planck theory of spin-torque switching: effective energy and transition-state rate theory  

NASA Astrophysics Data System (ADS)

A number of devices have been proposed and synthesized that exploit the spin torque effect. These systems are most straightforward to analyze in the absence of thermal effects. However, thermal effects are very important for the understanding of many experimental results, and for the design of devices. In spin torque MRAM, for example, although the very high-current behavior can be modeled without including thermal fluctuations, switching with currents low enough to be practical has a strong thermal component. Another example is the spin torque oscillator, whose usefulness in devices depends on its linewidth, which is strongly affected by thermal fluctuations. The statistical theory of spin torque systems has previously been worked out1 using the Fokker- Planck equation, which describes the time evolution of the probability density ?(M). In this paper we formulate the theory in terms of an effective energy, which has the advantage that the exact solution for the probability density has the familiar form exp(-VEeff/k?? ) in terms of the effective energy. We also generalize Eyring's 1935 transition state theory of rates to the spin torque case; it appears that in many practical cases this is a very good approximation.

Visscher, P. B.

2008-08-01

303

An Adaptive Maximum Torque Per Amp Control Strategy  

Microsoft Academic Search

Maximum torque per amp (MTPA) control of induction motor drives seeks to achieve a desired torque with the minimal possible stator current, which is favorable in terms of inverter operation, and nearly optimal in terms of machine efficiency. This work demonstrates that existing MTPA controls perform sub-optimally as temperature varies. An adaptive MTPA control strategy is proposed that always achieves

Chunki Kwon; Scott D. Sudhoff

2005-01-01

304

Unveiling The Nature Of Torque Reversals In Accreting Pulsars  

NASA Astrophysics Data System (ADS)

Observations suggest that torque reversals are a common property of the accretion- powered X-ray pulsars, independent of the spin period, the surface field of the neutron star, the nature of its donor companion, the intensity of the accretion process, and the geometry of the accretion flow. This challenges theoretical models in which the origin of the torque reversal is solely associated with one of the above properties and raises the question of whether the torque reversals are governed by the same processes in all accreting pulsars. In order to address this question we intend to perform a systematic comparative analysis of torque reversals observed in pulsars of different classes. Focusing on evolution of spectral and timing parameters of a pulsar between the torque reversal events we expect also to find what characterizes the spin-up and spin-down states other than the frequency rate. Utilizing both spectral and timing analysis we will be able to challenge such underlying assumptions about torque reversing pulsars as the presence of an accretion disk and whether the X-ray flux is a good proxy for the rate of mass transfer between the system components. Our systematic comparative data analysis across pulsar classes combined with our tests of existing torque-switching models will lead to an improved understanding of the physical mechanisms responsible for torque reversals.

Finger, Mark

305

Modeling torque transmissibility for automotive dry clutch engagement  

Microsoft Academic Search

The dry clutch is a fundamental component in many automotive drivelines. For instance, the clutch torque transmissibility characteristic severely influences gearshift performance in automated manual transmissions. In this paper a novel model of the torque transmissibility of dry clutches is proposed. The dependence of the transmissibility characteristic on wear, slip speed and friction pads geometry and the influence of the

Francesco Vasca; Luigi Iannelli; Adolfo Senatore; Maurizio Taglialatela Scafati

2008-01-01

306

A Brushless Permanent Magnet Motor With Integrated Torque-Limiter  

Microsoft Academic Search

Mechanical torque-limiters are used extensively to protect mechanical systems from overloads, in order to avoid damage, and the consequential downtime and repair costs. The paper describes a novel topology of permanent magnet brushless motor which incorporates an integrated magnetic torque-limiter, which is much simpler and volumetrically efficient

K. Atallah; S. D. Calverley; D. Howe

2007-01-01

307

Vibrations of a Pendulum with Oscillating Support and Extra Torque  

E-print Network

The motion of a driven planar pendulum with vertically periodically oscillating point of suspension and under the action of an additional constant torque is investigated. We study the influence of the torque strength on the transition to chaotic motions of the pendulum using Melnikov's analysis.

Marek Borowiec; Grzegorz Litak; Hans Troger

2006-07-19

308

The effect of movement direction on joint torque covariation  

Microsoft Academic Search

It has been proposed that unconstrained upper limb movements are coordinated via a kinetic constraint that produces dynamic muscle torques at each moving joint that are a linear function of a single torque command. This constraint has been termed linear synergy (Gottlieb et al. J Neurophysiol 75:1760–1764, 1996). The current study tested two hypotheses: (1) that the extent of covariation

Jonathan Shemmell; Ziaul Hasan; Gerald L. Gottlieb; Daniel M. Corcos

2007-01-01

309

Torque meter aids study of hysteresis motor rings  

NASA Technical Reports Server (NTRS)

Torque meter, simulating hysteresis motor operation, allows rotor ring performance characteristics to be analyzed. The meter determines hysteresis motor torque and actual stresses of the ring due to its mechanical situation and rotation, aids in the study of asymmetries or defects in motor rings, and measures rotational hysteresis.

Cole, M.

1967-01-01

310

14 CFR 23.397 - Limit control forces and -torques.  

Code of Federal Regulations, 2013 CFR

...criterion, the effects of control system boost and servo-mechanisms...it alone can produce higher control surface loads than the human...torques are as follows: Control Maximum forces or torques...lbs 4 40 D in.-lbs.4 Elevator: Stick 167 lbs 100...

2013-01-01

311

14 CFR 23.397 - Limit control forces and -torques.  

Code of Federal Regulations, 2010 CFR

...criterion, the effects of control system boost and servo-mechanisms...it alone can produce higher control surface loads than the human...torques are as follows: Control Maximum forces or torques...lbs 4 40 D in.-lbs.4 Elevator: Stick 167 lbs 100...

2010-01-01

312

14 CFR 23.397 - Limit control forces and -torques.  

Code of Federal Regulations, 2012 CFR

...criterion, the effects of control system boost and servo-mechanisms...it alone can produce higher control surface loads than the human...torques are as follows: Control Maximum forces or torques...lbs 4 40 D in.-lbs.4 Elevator: Stick 167 lbs 100...

2012-01-01

313

Evaluation of steel shafts for magnetostrictive torque sensors (abstract)  

Microsoft Academic Search

Based on the magnetostrictive effect in steel, a robust, noncontacting shaft torque sensor can be obtained. A fundamental problem in this scheme is compatibility between mechanical strength required for a shaft and a magnetic one needed for a torque sensor. In order to find shaft material accommodating these two requirements, we investigated basic characteristics, such as hysteresis, linearity, and zero-level

F. Koga; K. Yoshida; I. Sasada

1997-01-01

314

40 CFR 90.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Dynamometer torque cell calibration. 90.306 Section 90...Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2011-07-01

315

40 CFR 91.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Dynamometer torque cell calibration. 91.306 Section 91...Provisions § 91.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2012-07-01

316

40 CFR 91.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dynamometer torque cell calibration. 91.306 Section 91...Provisions § 91.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2010-07-01

317

40 CFR 90.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Dynamometer torque cell calibration. 90.306 Section 90...Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2013-07-01

318

40 CFR 91.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Dynamometer torque cell calibration. 91.306 Section 91...Provisions § 91.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2011-07-01

319

40 CFR 90.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dynamometer torque cell calibration. 90.306 Section 90...Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2010-07-01

320

40 CFR 91.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2014 CFR

...2013-07-01 true Dynamometer torque cell calibration. 91.306 Section 91...Provisions § 91.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2014-07-01

321

40 CFR 91.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Dynamometer torque cell calibration. 91.306 Section 91...Provisions § 91.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2013-07-01

322

40 CFR 90.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Dynamometer torque cell calibration. 90.306 Section 90...Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2012-07-01

323

40 CFR 90.306 - Dynamometer torque cell calibration.  

Code of Federal Regulations, 2014 CFR

...2013-07-01 true Dynamometer torque cell calibration. 90.306 Section 90...Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever...system. (b) Option. A master load-cell or transfer standard may be used to...

2014-07-01

324

Capillary torque in a liquid bridge between two angled filaments  

NASA Astrophysics Data System (ADS)

Capillary torque is induced when a liquid bridge forms between two angle-positioned filaments. This paper aims to study the dependency of such capillary torque upon the filament orientation angle, filament spacing, contact angle, and liquid volume through detailed numerical simulation using a surface finite element scheme. Numerical results show that for hydrophilic liquid with contact angle below 90° and at given liquid volume as well as filament spacing, the surface energy of the system grows nonlinearly with increasing filament orientation angle from 0° (parallel filaments) to 90° (cross-positioned filaments). Accordingly, the capillary torque induced by the distorted liquid bridge increases from a torque-free state at 0° to the peak value and then decreases to the second torque-free state at 90°. At fixed filament orientation angle, the capillary torque grows with the liquid volume while decreases rapidly with increasing either contact angle or filament spacing. The peak value of capillary torque depends upon both the geometries and wetting property of the liquid bridge-filament system. A family of characteristic curves in terms of capillary torque with the filament orientation angle is determined at varying volume of liquid bridge, filament spacing ratio, and contact angle. The results and concepts developed in work are applicable for the study of wetting and spreading of liquids in fiber networks, microfluidics-based microstructural assembly, biological cell operation, etc.

Bedarkar, Amol; Wu, Xiang-Fa

2009-12-01

325

Spin-transfer-torque effect in ferromagnets and antiferromagnets  

NASA Astrophysics Data System (ADS)

Spintronics in metallic multilayers, composed of ferromagnetic (F) and non-magnetic (N) metals, grew out of two complementary discoveries. The first, Giant Magneto-resistance (GMR), refers to a change in multilayer resistance when the relative orientation of magnetic moments in adjacent F-layers is altered by an applied magnetic field. The second, Spin-Transfer-Torque (STT), involves a change in the relative orientation of F-layer moments by an electrical current. This novel physical phenomenon offers unprecedented spatial and temporal control over the magnetic state of a ferromagnet and has tremendous potential in a broad range of technologies, including magnetic memory and recording. Because of its small size (<10nm), point contact is a very efficient probe of electrical transport properties in extremely small sample volumes yet inaccessible with other techniques. We have observed the point-contact excitations in magnetic multilayers at room temperature and extended the capabilities of our point-contact technique to include the sensitivity to wavelengths of the current-induced spin waves. Recently MacDonald and coworkers have predicted that similar to ferromagnetic multilayers, the magnetic state of an antiferromagnetic (AFM) system can affect its transport properties and result in antiferromagnetic analogue of giant magnetoresistance (GMR) = AGMR; while high enough electrical current density can affect the magnetic state of the system via spin-transfer-torque effect. We show that a high density dc current injected from a point contact into an exchange-biased spin valve (EBSV) can systematically change the exchange bias, increasing or decreasing it depending on the current direction. This is the first evidence for current-induced effects on magnetic moments in antiferromagnetic (FeMn or IrMn) metals. We searched for AGMR in multilayers containing different combinations of AFM=FeMn and F=CoFe layers. At low currents, no magnetoresistance (MR) was observed in any samples suggesting that no AGMR is present in these samples. In samples containing F-layers, high current densities sometimes produced a small positive MR -- largest resistance at high fields. For a given contact resistance, this MR was usually larger for thicker F-layers, and for a given current, it was usually larger for larger contact resistances (smaller contacts). We tentatively attribute this positive MR to suppression at high currents of spin accumulation induced around and within the F-layers.

Wei, Zhen

326

Optimization of torque-balanced asymmetric head gradient coils.  

PubMed

Local gradient coils can improve the performance of echo-planar, diffusion, and short TE imaging in the brain. A modified singular value decomposition algorithm, which allows the rapid optimization and comparison of designs, was employed to optimize head size gradient coils. A theoretical expression for the torque on a cylindrical coil is presented and used to design coils that are free from torque while pulsed within a magnetic field. Gradient coils of various lengths both with and without torque constraints were compared; although torque-free coils do not perform as well as unbalanced coils, asymmetric torque-balanced coils can achieve comparable homogeneity with only a modest increase in inductance and resistance. Both types of coils outperform body size gradient coils by a dramatic margin. A three-axis head gradient designed using these techniques was constructed and used for brain imaging on a clinical scanner. PMID:8744016

Alsop, D C; Connick, T J

1996-06-01

327

Magnetization dynamics with a spin-transfer torque  

NASA Astrophysics Data System (ADS)

The magnetization reversal and dynamics of a spin valve pillar, whose lateral size is 64×64 nm2, are studied by using micromagnetic simulation in the presence of spin-transfer torque. Spin torques display both characteristics of magnetic damping (or antidamping) and of an effective magnetic field. For a steady-state current, both M-I and M-H hysteresis loops show unique features, including multiple jumps, unusual plateaus, and precessional states. These states originate from the competition between the energy dissipation due to Gilbert damping and the energy accumulation due to the spin torque supplied by the spin current. The magnetic energy oscillates as a function of time even for a steady-state current. For a pulsed current, the minimum width and amplitude of the spin torque for achieving current-driven magnetization reversal are quantitatively determined. The spin torque also shows very interesting thermal activation that is fundamentally different from an ordinary damping effect.

Li, Z.; Zhang, S.

2003-07-01

328

Magnon-mediated Dzyaloshinskii-Moriya torque in homogeneous ferromagnets  

NASA Astrophysics Data System (ADS)

In thin magnetic layers with structural inversion asymmetry and spin-orbit coupling, the Dzyaloshinskii-Moriya interaction arises at the interface. When a spin-wave current jm flows in a system with a homogeneous magnetization m, this interaction produces an effective fieldlike torque of the form TFL?m ×(z ×jm) as well as a dampinglike torque, TDL?m ×[(z ×jm) ×m ] , the latter only in the presence of spin-wave relaxation (z is normal to the interface). These torques mediated by the magnon flow can reorient the time-averaged magnetization direction and display a number of similarities with the torques arising from the electron flow in a magnetic two-dimensional electron gas with Rashba spin-orbit coupling. This magnon-mediated spin-orbit torque can be efficient in the case of magnons driven by a thermal gradient.

Manchon, Aurélien; Ndiaye, Papa Birame; Moon, Jung-Hwan; Lee, Hyun-Woo; Lee, Kyung-Jin

2014-12-01

329

Optical torque from enhanced scattering by multipolar plasmonic resonance  

NASA Astrophysics Data System (ADS)

We present a theoretical study of the optical angular momentum transfer from a circularly polarized plane wave to thin metal nanoparticles of different rotational symmetries. While absorption has been regarded as the predominant mechanism of torque generation on the nanoscale, we demonstrate numerically how the contribution from scattering can be enhanced by using multipolar plasmon resonance. The multipolar modes in non-circular particles can convert the angular momentum carried by the scattered field and thereby produce scattering-dominant optical torque, while a circularly symmetric particle cannot. Our results show that the optical torque induced by resonant scattering can contribute to 80% of the total optical torque in gold particles. This scattering-dominant torque generation is extremely mode-specific, and deserves to be distinguished from the absorption-dominant mechanism. Our findings might have applications in optical manipulation on the nanoscale as well as new designs in plasmonics and metamaterials.

Lee, Yoonkyung E.; Fung, Kin Hung; Jin, Dafei; Fang, Nicholas X.

2014-12-01

330

Alternating bending-steady torque fatigue reliability  

NASA Technical Reports Server (NTRS)

Results generated by three unique fatigue reliability research machines which can apply alternating-bending loads combined with steady torque are presented. Six-inch long, AISI steel, grooved specimens with a stress concentration factor of 1.42 and Rockwell C 35/40 hardness were subjected to various combinations of these loads and cycled to failure. The generated cycles-to-failure and staircase-testing data are statistically analyzed to develop distributional S-N and Goodman diagrams. Various failure theories are investigated to determine which one best represents the data. The effect of the groove and of the various combined bending-torsion loads on the finite and endurance life strength of such components, as well as on the Goodman diagram, are determined. Design applications are presented.

Kececioglu, D.; Chester, L. B.; Dodge, T. M.

1974-01-01

331

Coherence of spin-torque microwave oscillators  

NASA Astrophysics Data System (ADS)

Recently discovered effect of microwave generation in current-driven magnetic nano-structures caused by the spin-transfer torque opens a possibility for the development of a new class of tunable microwave auto-oscillators. The spin-torque oscillators (STO) are strongly nonlinear as their frequency ?(P) and total (positive plus negative) damping ?(P) are dependent on the oscillation power P . We developed a theory of the generation linewidth of a nonlinear auto-oscillator, and showed that the nonlinear frequency shift (characterized by the coefficientN=d?/dP) leads to an effective increase of the phase noise. In a strongly supercritical regime, when the oscillation energy E(P) is much larger than the thermal energy kBT, the generation linewidth of a STO can be written as ??=??0[1+(N/?eff)^2], where ??0=?(0)[kBT/E(P)] is the oscillator linewidth without account for the nonlinear frequency shift and ?eff=d?/dP is the effective nonlinear damping of the oscillator. Our theory explains the following features of the STO linewidth observed in experiment: (i) general linewidth narrowing with the increases in the bias current I and the oscillation energy E(P); (ii) presence of a minimum in the linewidth dependence on the orientation of the external bias magnetic field; (iii) linear dependence of the linewidth on the absolute temperature. Our theory also demonstrates that in the array of n phase-locked STO the generation linewidth decreases linearly with the increase on the number of oscillators n, while the generated power P increases as n^2.

Slavin, Andrei

2008-03-01

332

Improvement of Torque Response and Examination of Sensorless Drive System Based on Direct Torque Control for IPMSM  

NASA Astrophysics Data System (ADS)

This paper examines the sensorless control system based on the direct torque control (DTC) for an interior permanent magnet synchronous motor (IPMSM). In the DTC system, the rotor position is not required, and the rotor speed is estimated from the estimated position of stator flux-linkage vector. In addition, the maximum torque per ampere (MTPA) control and the flux weakening (FW) control can be applied to the DTC as well as the current control method in the d-q reference frame. Therefore the DTC can operate over a wide speed range. The characteristic of the maximum power operation is shown by the experimental result. The torque response is investigated by the simulation and experimental results. A relationship between the controller gain and torque response is shown, and an improvement method of the torque response is proposed.

Inoue, Yukinori; Morimoto, Shigeo; Sanada, Masayuki

333

N-acetyl-L-cysteine affects growth, extracellular polysaccharide production, and bacterial biofilm formation on solid surfaces.  

PubMed

N-Acetyl-L-cysteine (NAC) is used in medical treatment of patients with chronic bronchitis. The positive effects of NAC treatment have primarily been attributed to the mucus-dissolving properties of NAC, as well as its ability to decrease biofilm formation, which reduces bacterial infections. Our results suggest that NAC also may be an interesting candidate for use as an agent to reduce and prevent biofilm formation on stainless steel surfaces in environments typical of paper mill plants. Using 10 different bacterial strains isolated from a paper mill, we found that the mode of action of NAC is chemical, as well as biological, in the case of bacterial adhesion to stainless steel surfaces. The initial adhesion of bacteria is dependent on the wettability of the substratum. NAC was shown to bind to stainless steel, increasing the wettability of the surface. Moreover, NAC decreased bacterial adhesion and even detached bacteria that were adhering to stainless steel surfaces. Growth of various bacteria, as monocultures or in a multispecies community, was inhibited at different concentrations of NAC. We also found that there was no detectable degradation of extracellular polysaccharides (EPS) by NAC, indicating that NAC reduced the production of EPS, in most bacteria tested, even at concentrations at which growth was not affected. Altogether, the presence of NAC changes the texture of the biofilm formed and makes NAC an interesting candidate for use as a general inhibitor of formation of bacterial biofilms on stainless steel surfaces. PMID:12902275

Olofsson, Ann-Cathrin; Hermansson, Malte; Elwing, Hans

2003-08-01

334

28 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 49, NO. 1, FEBRUARY 2002 Minimization of Torque Ripple in SRM Drives  

E-print Network

- acteristics of the motor dictate the amount of torque ripple during operation. Both machine design of the motor, while the other is to use sophisticated electronic control techniques. The machine designers production mechanisms be- tween the SRM and other conventional dc or ac machines is the dependency

Husain, Iqbal

335

Standard practice for torque calibration of testing machines and devices  

E-print Network

1.1 This practice covers procedures and requirements for the calibration of torque for static and quasi-static torque capable testing machines or devices. These may, or may not, have torque indicating systems and include those devices used for the calibration of hand torque tools. Testing machines may be calibrated by one of the three following methods or combination thereof: 1.1.1 Use of standard weights and lever arms. 1.1.2 Use of elastic torque measuring devices. 1.1.3 Use of elastic force measuring devices and lever arms. 1.1.4 Any of the methods require a specific uncertainty of measurement and a traceability derived from national standards of mass and length. 1.2 The procedures of 1.1.1, 1.1.2, and 1.1.3 apply to the calibration of the torque-indicating systems associated with the testing machine, such as a scale, dial, marked or unmarked recorder chart, digital display, etc. In all cases the buyer/owner/user must designate the torque-indicating system(s) to be calibrated and included in the repor...

American Society for Testing and Materials. Philadelphia

2009-01-01

336

Development of a multilayered wide-ranged torque magnetorheological brake  

NASA Astrophysics Data System (ADS)

This paper presents the design of a multilayered magnetorheological brake from modelling to prototyping and characterization. A magnetostatic model intended to provide a specific magnetic flux density over a fluid gap regardless of the dimensions of the fluid surface is proposed. The ferromagnetic path and the coil are dimensioned in consequence. The model needs only three inputs to completely define the brake, i.e. the number of fluid gaps, the inner radius of the smallest fluid gap and the fluid gap depth. The evaluation criteria are defined by the torque density, the controllability and the reactivity, described as a function of the dimensions and the number of fluid gaps. The model has been optimized to improve the torque density. The brake has four fluid gaps and has been built and characterized. The expected torque when the fluid reaches the desired induction is 3.4 N m and the measured torque is 3.6 N m. This represents a relative error of 5.5%. The brake has 60 mm diameter, 39 mm width with a hollow shaft of 12 mm diameter. When exploited up to complete saturation, the measured torque is 5.3 N m with 19 W power consumption. The brake has a torque density of 48.1 kN m-2 and a maximum-to-minimum torque ratio of 176, with 50 ms electromechanical time constant.

Rossa, Carlos; Jaegy, Adrien; Micaelli, Alain; Lozada, José

2014-02-01

337

Lunar and Solar Torques on the Oceanic Tides  

NASA Technical Reports Server (NTRS)

Brosche and Seiler recently suggested that direct lunar and solar tidal torques on the oceanic tides play a significant role in the earth's short-period angular momentum balance ("short-period" here meaning daily and sub-daily). We reexamine that suggestion here, concentrating on axial torques and hence on variations in rotation rate. Only those spherical harmonic components of the ocean tide having the same degree and order as the tidal potential induce nonzero torques. Prograde components (those moving in the same direction as the tide-generating body) produce the familiar secular braking of the earth's rotation. Retrograde components, however, produce rapid variations in UTI at twice the tidal frequency. There also exist interaction torques between tidal constituents, e.g. solar torques on lunar tides. They generate UTI variations at frequencies equal to the sums and differences of the original tidal frequencies. We give estimates of the torques and angular momentum variations for each of the important regimes, secular to quarter-diurnal. For the M(sub 2) potential acting on the M(sub 2) ocean tide, we find an associated angular momentum variation of amplitude 3 x 10(exp 19) N m. This is 5 to 6 orders of magnitude smaller than the angular momentum variations associated with tidal currents. We conclude that these torques do not play a significant role in the short-period angular momentum balance.

Ray, Richard D.; Bills, Bruce G.; Chao, Benjamin F.

1998-01-01

338

Analyzing the installation angle error of a SAW torque sensor  

NASA Astrophysics Data System (ADS)

When a torque is applied to a shaft, normal strain oriented at ±45° direction to the shaft axis is at its maximum, which requires two one-port SAW resonators to be bonded to the shaft at ±45° to the shaft axis. In order to make the SAW torque sensitivity high enough, the installation angle error of two SAW resonators must be confined within ±5° according to our design requirement. However, there are few studies devoted to the installation angle analysis of a SAW torque sensor presently and the angle error was usually obtained by a manual method. Hence, we propose an approximation method to analyze the angle error. First, according to the sensitive mechanism of the SAW device to torque, the SAW torque sensitivity is deduced based on the linear piezoelectric constitutive equation and the perturbation theory. Then, when a torque is applied to the tested shaft, the stress condition of two SAW resonators mounted with an angle deviating from ±45° to the shaft axis, is analyzed. The angle error is obtained by means of the torque sensitivities of two orthogonal SAW resonators. Finally, the torque measurement system is constructed and the loading and unloading experiments are performed twice. The torque sensitivities of two SAW resonators are obtained by applying average and least square method to the experimental results. Based on the derived angle error estimation function, the angle error is estimated about 3.447°, which is close to the actual angle error 2.915°. The difference between the estimated angle and the actual angle is discussed. The validity of the proposed angle error analysis method is testified to by the experimental results.

Fan, Yanping; Ji, Xiaojun; Cai, Ping

2014-09-01

339

Torque characteristics of solid lubricated precision bearings during oscillatory motion  

NASA Astrophysics Data System (ADS)

MoS2 sputter-coated as well as uncoated (bare) angular-contact ball bearings were tested with various cage materials in a low-speed regime. Various self-lubricating polymers either neat or with additives and metallic cages were tested. The emphasis of this paper is to report on significant torque increases torque bumps observed during non-ball overlap, oscillatory motion for some race/cage combinations. In some race/cage combinations torque bumps can be minimized by proper run-in. No attempt was made to run the bearings to failure, although certain race/cage combinations did in fact fail before the end of test.

Bauer, Reinhold; Fleischauer, Paul D.

1994-01-01

340

Surface modification of clutch plates to reduce disengaged drag torque  

NASA Astrophysics Data System (ADS)

Viscous drag torque in disengaged clutches is a significant source of power loss in modern transportation. The main way to reduce this drag torque is to introduce air between the plates when disengaged without reducing the transmission fluid flow eventually needed for reengagement. Six different groove patterns are tested experimentally to determine which have the lowest drag characteristics. Our computations using Fluent showed that the contact angle made by oil with the stationary plate is critical in determining aeration initiation. Experiments coating the stationary plate with an oleophobic substance like Teflon, confirmed these simulations. We will show torque comparisons and visualization through a quartz disk acting as one of the clutch plates.

Aphale, Chinar R.

2005-11-01

341

The effect of annealing on the spin-transfer torques of MgO MTJ nanopillars  

NASA Astrophysics Data System (ADS)

Thermal annealing is essential for enhancing the tunneling magnetoresistane (TMR) of magnetic tunnel junctions, and many studies have focused on the effect of annealing on MTJ chemical, structural, and electrical transport properties. Here, we report the magnetic, electronic properties and the in-plane and field-like spin-transfer torques (STT) in both as-grown and post-annealed FeCoB/MgO/FeCoB MTJs nanopillars. We find that the 350 C vacuum annealing breaks the symmetry of the bias dependence of the TMR, conductivity, and switching phase diagram (SPD). Moreover STT-FMR measurements indicate that annealing substantially increases the in-plane torque asymmetry with bias voltage direction, as well as affecting the field-like torque magnitude, with the latter indicating a very significant enhancement of interlayer exchange coupling across the barrier. This STT change is consistent with the change in chemical composition and structural coherency of the MTJ interfaces and electrodes, indicated by XRD and analytical STEM analyzes.

Li, Yun; Tseng, Hsin-Wei; Huang, Pinshane; Read, John; Ralph, Dan; Buhrman, Robert

2011-03-01

342

Changes in the carboxyl-terminal repeat region affect extracellular activity and glucan products of Streptococcus gordonii glucosyltransferase.  

PubMed Central

Glucans produced by the glucosyltransferase (GTF) of Streptococcus gordonii confer a hard, cohesive phenotype (Spp+) on colonies grown on sucrose agar plates. S. gordonii strains with specific mutations in the region of gtfG that encodes the GTF carboxyl terminus were characterized. In the parental strain Challis CH1, this region included a series of six direct repeats thought to function in glucan binding. The spontaneous mutant strain CH107 had a 585-bp deletion resulting in the loss of three internal direct repeats. Insertional mutagenesis was used to construct strain CH2RPE, which had the parental repeat region but was missing 14 carboxyl-terminal amino acids. The similarly constructed strain CH4RPE had an in-frame addition of 390 nucleotides encoding two additional direct repeats. Although strains CH1, CH2RPE, and CH4RPE all had similar levels of extracellular GTF activity, strain CH107 had less than 15% of the parental activity; however, Western blots (immunoblots) indicated that the amounts of extracellular GTF protein in all four strains were similar. 13C NMR analyses indicated that partially purified GTFs from the Spp+ strains CH1, CH2RPE, and CH4RPE all produced glucans with similar ratios of alpha1,6 and alpha1,3 glucosidic linkages, whereas the Spp- strain CH107 GTF produced primarily alpha1,6-linked glucans. Transformation of strain CH107 with pAMS57, which carries the gtfG positive regulatory determinant, rgg, increased the amount of GTF activity and GTF antibody-reactive protein ca. fivefold but did not confer a hard colony phenotype on sucrose agar plates, suggesting that the type of glucan product affects the sucrose-promoted colony phenotype. PMID:8945555

Vickerman, M M; Sulavik, M C; Minick, P E; Clewell, D B

1996-01-01

343

Micro-leakage at the implant-abutment interface with different tightening torques in vitro  

PubMed Central

Objectives This study evaluated the microleakage at the implant/abutment interface of external hexagon (EH) implants and abutments with different amounts of bacteria and tightening torques. Material and Methods A bacterial suspension was prepared to inoculate the implants. The first phase of this study used nine EH implants and abutments that were divided into three groups with different amounts of bacterial suspension (n=3): V0.5: 0.5 µL; V1.0: 1.0 µL e V1.5: 1.5 µL, and tightened to the manufacturer's recommended torque. The second phase of this experiment used 27 assemblies that were similar to those used in the first phase. These samples were inoculated with 0.5 µL of bacterial suspension and divided into three groups (n=9). T10: 10 Ncm; T20: 20 Ncm and T32: 32 Ncm. The samples were evaluated according to the turbidity of the broth every 24 hours for 14 days, and the bacteria viability was tested after that period. The statistical evaluation was conducted by Kruskal-Wallis testing (p<.05). Results During the first phase, groups V1.0 and V1.5 was presented with bacterial contamination in all samples after 24 h. During the second phase, two samples from group T10 and one from T20 presented positive results for bacterial contamination. Different amounts of bacterial solution led to overflow and contamination during the first 24 h of the experiment. The tightening torques did not statistically affect the microleakage in the assemblies. However, the group that was tightened to 32 Ncm torque did not show any bacterial contamination. Conclusion After 14 days of experimentation, the bacteria were proven to remain viable inside the implant internal cavity. PMID:23138747

da SILVA-NETO, João Paulo; PRUDENTE, Marcel Santana; CARNEIRO, Thiago de Almeida Prado Naves; NÓBILO, Mauro Antônio de Arruda; PENATTI, Mario Paulo Amante; NEVES, Flávio Domingues das

2012-01-01

344

The Effect of Sex and Age on Isokinetic Hip-Abduction Torques  

PubMed Central

Context As high school female athletes demonstrate a rate of noncontact anterior cruciate ligament (ACL) injury 3–6 times higher than their male counterparts, research suggests that sagittal-plane hip strength plays a role in factors associated with ACL injuries. Objective To determine if gender or age affect hip-abductor strength in a functional standing position in young female and male athletes. Design Prospective cohort design. Setting Biomechanical laboratory. Participants Over a 3-y time period, 852 isokinetic hip-abduction evaluations were conducted on 351 (272 female, 79 male) adolescent soccer and basketball players. Intervention Before testing, athletes were secured in a standing position, facing the dynamometer head, with a strap secured from the uninvolved side and extending around the waist just above the iliac crest. The dynamometer head was positioned in line with the body in the coronal plane by aligning the axis of rotation of the dynamometer with the center of hip rotation. Subjects performed 5 maximum-effort repetitions at a speed of 120°/s. The peak torque was recorded and normalized to body mass. All test trials were conducted by a single tester to limit potential interrater test error. Main Outcome Measure Standing isokinetic hip-abduction torque. Results Hip-abduction torque increased in both males and females with age (P < .001) on both the dominant and nondominant sides. A significant interaction of gender and age was observed (P < .001), which indicated that males experienced greater increases in peak torque relative to body weight than did females as they matured. Conclusions Males exhibit a significant increase in normative hip-abduction strength, while females do not. Future study may determine if the absence of similar increased relative hip-abduction strength in adolescent females, as they age, may be related to their increased risk of ACL injury compared with males. PMID:22715125

Brent, Jensen L.; Myer, Gregory D.; Ford, Kevin R.; Paterno, Mark V.; Hewett, Timothy E.

2014-01-01

345

Highly sensitive nanoscale spin-torque diode.  

PubMed

Highly sensitive microwave devices that are operational at room temperature are important for high-speed multiplex telecommunications. Quantum devices such as superconducting bolometers possess high performance but work only at low temperature. On the other hand, semiconductor devices, although enabling high-speed operation at room temperature, have poor signal-to-noise ratios. In this regard, the demonstration of a diode based on spin-torque-induced ferromagnetic resonance between nanomagnets represented a promising development, even though the rectification output was too small for applications (1.4?mV?mW(-1)). Here we show that by applying d.c. bias currents to nanomagnets while precisely controlling their magnetization-potential profiles, a much greater radiofrequency detection sensitivity of 12,000?mV?mW(-1) is achievable at room temperature, exceeding that of semiconductor diode detectors (3,800?mV?mW(-1)). Theoretical analysis reveals essential roles for nonlinear ferromagnetic resonance, which enhances the signal-to-noise ratio even at room temperature as the size of the magnets decreases. PMID:24141450

Miwa, S; Ishibashi, S; Tomita, H; Nozaki, T; Tamura, E; Ando, K; Mizuochi, N; Saruya, T; Kubota, H; Yakushiji, K; Taniguchi, T; Imamura, H; Fukushima, A; Yuasa, S; Suzuki, Y

2014-01-01

346

Mechanics of torque generation in the bacterial flagellar motor  

E-print Network

The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well-established that the passage of ions down a transmembrane gradient through the stator complex provides the energy needed for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, while steric forces comprise the actual 'power stroke'. Specifically, we predict that ion-induced conformational changes about a proline 'hinge' residue in an $\\alpha$-helix of the stator are directly responsible for generating the power stroke. Our model predictions f...

Mandadapu, Kranthi K; Berry, Richard M; Oster, George

2015-01-01

347

Knudsen torque: a rotational mechanism driven by thermal force.  

PubMed

Thermally induced mechanical loading has been shown to have significant effects on micro- and nano-objects immersed in a gas with a nonuniform temperature field. While the majority of existing studies and related applications focus on forces, we investigate the torque, and thus the rotational motion, produced by such a mechanism. Our study has found that a torque can be induced if the configuration of the system is asymmetric. In addition, both the magnitude and the direction of the torque depend highly on the system configuration, indicating the possibility of manipulating the rotational motion via geometrical design. Based on this feature, two types of rotational micromotor that are of practical importance, namely pendulum motor and unidirectional motor, are designed. The magnitude of the torque at Kn=0.5 can reach to around 2nN×?m for a rectangular microbeam with a length of 100?m. PMID:25314531

Li, Qi; Liang, Tengfei; Ye, Wenjing

2014-09-01

348

Knudsen torque: A rotational mechanism driven by thermal force  

NASA Astrophysics Data System (ADS)

Thermally induced mechanical loading has been shown to have significant effects on micro- and nano-objects immersed in a gas with a nonuniform temperature field. While the majority of existing studies and related applications focus on forces, we investigate the torque, and thus the rotational motion, produced by such a mechanism. Our study has found that a torque can be induced if the configuration of the system is asymmetric. In addition, both the magnitude and the direction of the torque depend highly on the system configuration, indicating the possibility of manipulating the rotational motion via geometrical design. Based on this feature, two types of rotational micromotor that are of practical importance, namely pendulum motor and unidirectional motor, are designed. The magnitude of the torque at Kn =0.5 can reach to around 2nN×?m for a rectangular microbeam with a length of 100?m.

Li, Qi; Liang, Tengfei; Ye, Wenjing

2014-09-01

349

Torque fluctuations caused by upstream mean flow and turbulence  

NASA Astrophysics Data System (ADS)

A series of studies are in progress investigating the effects of turbine-array-wake interactions for a range of atmospheric boundary layer states by means of the EnFlo meteorological wind tunnel. The small, three-blade model wind turbines drive 4-quadrant motor-generators. Only a single turbine in neutral flow is considered here. The motor-generator current can be measured with adequate sensitivity by means of a current sensor allowing the mean and fluctuating torque to be inferred. Spectra of torque fluctuations and streamwise velocity fluctuations ahead of the rotor, between 0.1 and 2 diameters, show that only the large-scale turbulent motions contribute significantly to the torque fluctuations. Time-lagged cross-correlation between upstream velocity and torque fluctuations are largest over the inner part of the blade. They also show the turbulence to be frozen in behaviour over the 2 diameters upstream of the turbine.

Farr, T. D.; Hancock, P. E.

2014-12-01

350

The stall torque of the bacterial flagellar motor.  

PubMed Central

The bacterial flagellar motor couples the flow of protons across the cytoplasmic membrane to the rotation of a helical flagellar filament. Using tethered cells, we have measured the stall torque required to block this rotation and compared it with the torque of the running motor over a wide range of values of proton-motive force and pH. The stall torque and the running torque vary identically: both appear to saturate at large values of the proton-motive force and both decrease at low or high pH. This suggests that up to speeds of approximately 5 Hz the operation of the motor is not limited by the mobility of its internal components or the rates of proton transfer reactions coupled to flagellar rotation. Images FIGURE 1 PMID:3651560

Meister, M; Berg, H C

1987-01-01

351

Chiral spin torque arising from proximity-induced magnetization  

NASA Astrophysics Data System (ADS)

Domain walls can be driven by current at very high speeds in nanowires formed from ultra-thin, perpendicularly magnetized cobalt layers and cobalt/nickel multilayers deposited on platinum underlayers due to a chiral spin torque. An important feature of this torque is a magnetic chiral exchange field that each domain wall senses and that can be measured by the applied magnetic field amplitude along the nanowire where the domain walls stop moving irrespective of the magnitude of the current. Here we show that this torque is manifested when the magnetic layer is interfaced with metals that display a large proximity-induced magnetization, including iridium, palladium and platinum but not gold. A correlation between the strength of the chiral spin torque and the proximity-induced magnetic moment is demonstrated by interface engineering using atomically thin dusting layers. High domain velocities are found where there are large proximity-induced magnetizations in the interfaced metal layers.

Ryu, Kwang-Su; Yang, See-Hun; Thomas, Luc; Parkin, Stuart S. P.

2014-05-01

352

Chiral spin torque arising from proximity-induced magnetization.  

PubMed

Domain walls can be driven by current at very high speeds in nanowires formed from ultra-thin, perpendicularly magnetized cobalt layers and cobalt/nickel multilayers deposited on platinum underlayers due to a chiral spin torque. An important feature of this torque is a magnetic chiral exchange field that each domain wall senses and that can be measured by the applied magnetic field amplitude along the nanowire where the domain walls stop moving irrespective of the magnitude of the current. Here we show that this torque is manifested when the magnetic layer is interfaced with metals that display a large proximity-induced magnetization, including iridium, palladium and platinum but not gold. A correlation between the strength of the chiral spin torque and the proximity-induced magnetic moment is demonstrated by interface engineering using atomically thin dusting layers. High domain velocities are found where there are large proximity-induced magnetizations in the interfaced metal layers. PMID:24852680

Ryu, Kwang-Su; Yang, See-Hun; Thomas, Luc; Parkin, Stuart S P

2014-01-01

353

Robust maximum torque per amp (MTPA) control of PM-assisted synchronous reluctance motor  

Microsoft Academic Search

In this paper, a practical maximum torque per ampere control scheme along with a simple parameter estimator for PMa-SynRM is introduced. In this method, MTPA condition is achieved by calculation of the output torque and perturbing one variable while seeking the maximum output torque at the particular operating point. The maximization of the electromagnetic torque might be sensitive to the

Peyman Niazi; Hamid A. Toliyat

2006-01-01

354

Direct torque control scheme of IM drive with 12-sided polygonal voltage space vectors  

Microsoft Academic Search

The application like electric vehicles requires frequent torque control to control speed of IM Drives. The direct torque control is very good control scheme for fast torque control and it is easy to implement and decoupling of motor variables along rotor flux axis is not required. In this paper, direct torque control scheme is proposed using 12-sided polygonal space vector

Chintan Patel; Rijil Ramchand; P. P. Rajeevan; K. Sivakumar; Anandarup Das; K. Gopakumar; Marian P. Kazmierkowski

2011-01-01

355

Modeling and Analysis of a High Torque, Hydrostatic Actuator for Robotic Applications  

Microsoft Academic Search

The goal of this research is to develop a robot actuator capable of producing and controlling large output torques. Because of friction and backlash, it is difficult to control large output torques if they are obtained from an electric motor through a gear train. If no gearing is used, it is possible to accurately control torque output, but large torques

James E. Bobrow; Jayesh Desai

1989-01-01

356

A position sensor based torque control method for a DC motor with reduction gears  

Microsoft Academic Search

A control structure suitable for torque control using a geared DC servomotor discussed. The torque sensory feedback is advantageous for the fine torque generation by geared DC motors. However, it reduces the structural stiffness and in turn causes a low response in both the torque and position controls. To improve this, it is suggested that the natural frequency of the

K. Tanie; K. Yokoi; M. Kaneko; T. Fukuda

1988-01-01

357

Spintronic Memristor Through Spin-Torque-Induced Magnetization Motion  

Microsoft Academic Search

Existence of spintronic memristor in nanoscale is demonstrated based upon spin-torque-induced magnetization switching and magnetic-domain-wall motion. Our examples show that memristive effects are quite universal for spin-torque spintronic device at the time scale that explicitly involves the interactions between magnetization dynamics and electronic charge transport. We also proved that the spintronic device can be designed to explore and memorize the

Xiaobin Wang; Yiran Chen; Haiwen Xi; Hai Li; Dimitar Dimitrov

2009-01-01

358

Direct shaft torque measurements in a transient turbine facility  

NASA Astrophysics Data System (ADS)

This paper describes the development and implementation of a shaft torque measurement system for the Oxford Turbine Research Facility (formerly the Turbine Test Facility (TTF) at QinetiQ, Farnborough), or OTRF. As part of the recent EU TATEF II programme, the facility was upgraded to allow turbine efficiency measurements to be performed. A shaft torque measurement system was developed as part of this upgrade. The system is unique in that, to the authors' knowledge, it provided the first direct measurement of shaft torque in a transient turbine facility although the system has wider applicability to rotating test facilities in which power measurement is a requirement. The adopted approach removes the requirement to quantify bearing friction, which can be difficult to accurately calibrate under representative operating conditions. The OTRF is a short duration (approximately 0.4 s run time) isentropic light-piston facility capable of matching all of the non-dimensional parameters important for aerodynamic and heat studies, namely Mach number, Reynolds number, non-dimensional speed, stage pressure ratio and gas-to-wall temperature ratio. The single-stage MT1 turbine used for this study is a highly loaded unshrouded design, and as such is relevant to modern military, or future civil aero-engine design. Shaft torque was measured directly using a custom-built strain gauge-based torque measurement system in the rotating frame of reference. This paper describes the development of this measurement system. The system was calibrated, including the effects of temperature, to a traceable primary standard using a purpose-built facility. The bias and precision uncertainties of the measured torque were ±0.117% and ±0.183%, respectively. To accurately determine the shaft torque developed by a turbine in the OTRF, small corrections due to inertial torque (associated with changes in the rotational speed) and aerodynamic drag (windage) are required. The methods for performing these corrections are described.

Beard, Paul F.; Povey, Thomas

2011-03-01

359

Torque magnetometry on thin magnetite films at low temperatures  

Microsoft Academic Search

Torque magnetometry was used to investigate the magnetic anisotropy of epitaxial Fe3O4 films of thicknesses 420 and 40nm grown by pulsed laser deposition on (001) MgO substrates. Torque measurements at 130K in the (11?0) plane allow us to evaluate the influence of shape and stress anisotropy. As in bulk material field-cooled measurements performed at T=5K show that the magnetic anisotropy

R. Höhne; C. A Kleint; A. V. Pan; M. K Krause; M. Ziese; P. Esquinazi

2000-01-01

360

Estimates of the dissipative heat and axial torque generated by ocean tides on icy satellites in the outer solar system.  

NASA Astrophysics Data System (ADS)

The tidal flow response generated in a satellite ocean depends strongly on the ocean configuration parameters as these parameters control the form and frequencies of the ocean's natural modes of oscillation; if there is a near match between the form and frequency of one of these natural modes and that of one of the available tidal forcing constituents, the ocean can be resonantly excited, producing a strong tidal response. The fundamental elements of the response are described by the tidal flow and surface fluctuations. Derivative elements of the response include the associated dissipative heat, stress, and forces/torques. The dissipative heat has received much previous attention as it may be important in explaining the heat budget on several of the satellites in the Outer Solar System. While these estimates will be reviewed and compared with the tidal dissipation estimates compiled in Hussman et al. (2010), the primary goal in this presentation is to extend the analysis to consider the tidally generated axial torque on the satellites and the potential consquences for rotation. Interestingly, even a synchronously rotating satellite will, if a global fluid layer is included, experience a complex set of opportunities for torques in both the prograde and retrograde sense. The amplitude and sense of the torque sensitively depends on the ocean parameters controlling the tidal response. This sensitivity, combined with expected feedbacks whereby the tides affect the orbital parameters, suggests that the evolution of the satellite system will experience phases of both prograde and retrograde tidal torques during its evolution. A related point is that parameters of the ocean might be inferred from inferences or observations of torque or rotational deviations. In the panels to the right we show the nondimensional tidal torques associated with obliquity (top) and eccentricity (bottom). The parameters described in the labeling are the fluid density ?, surface gravity g, ocean surface area A, tidal equilibrium height ?F, dissipation quality factor Q,and c=(gh)1/2, cr=?a, with ocean thickness h, rotation rate ?, and radius a. Torque due to tides forced by obliquity as a function of the parameters c/cr and Q. Retrograde ("Westward") and prograde ("Eastward") components shown in left and right panels, respectively. Log10 scale shown in colorbar.

Tyler, R.

2012-09-01

361

Mechanics of torque generation in the bacterial flagellar motor  

E-print Network

The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well-established that the passage of ions down a transmembrane gradient through the stator complex provides the energy needed for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, while steric forces comprise the actual 'power stroke'. Specifically, we predict that ion-induced conformational changes about a proline 'hinge' residue in an $\\alpha$-helix of the stator are directly responsible for generating the power stroke. Our model predictions fit well with recent experiments on a single-stator motor. Furthermore, we propose several experiments to elucidate the torque-speed relationship in motors where the number of stators may not be constant. The proposed model provides a mechanical explanation for several fundamental features of the flagellar motor, including: torque-speed and speed-ion motive force relationships, backstepping, variation in step sizes, and the puzzle of swarming experiments.

Kranthi K. Mandadapu; Jasmine A. Nirody; Richard M. Berry; George Oster

2015-01-13

362

Torqued fireballs in relativistic heavy-ion collisions  

E-print Network

We show that the fluctuations in the wounded-nucleon model of the initial stage of relativistic heavy-ion collisions, together with the natural assumption that the forward (backward) moving wounded nucleons emit particles preferably in the forward (backward) direction, lead to an event-by-event torqued fireball. The principal axes associated with the transverse shape are rotated in the forward region in the opposite direction than in the backward region. On the average, the standard deviation of the relative torque angle between the forward and backward rapidity regions is about 20deg for the central and 10deg for the mid-peripheral collisions. The hydrodynamic expansion of a torqued fireball leads to a torqued collective flow, yielding, in turn, torqued principal axes of the transverse-momentum distributions at different rapidities. We propose experimental measures, based on cumulants involving particles in different rapidity regions, which should allow for a quantitative determination of the effect from the data. To estimate the non-flow contributions from resonance decays we run Monte Carlo simulations with THERMINATOR. If the event-by-event torque effect is found in the data, it will support the assumptions concerning the fluctuations in the early stage of the fireball formation, as well as the hypothesis of the asymmetric rapidity shape of the emission functions of the moving sources in the nucleus-nucleus collisions.

Piotr Bozek; Wojciech Broniowski; Joao Moreira

2012-03-29

363

Torqued fireballs in relativistic heavy-ion collisions  

SciTech Connect

We show that the fluctuations in the wounded-nucleon model of the initial stage of relativistic heavy-ion collisions, together with the natural assumption that the forward- (backward-) moving wounded nucleons emit particles preferably in the forward (backward) direction, lead to an event-by-event torqued fireball. The principal axes associated with the transverse shape are rotated in the forward region in the opposite direction than in the backward region. On the average, the standard deviation of the relative torque angle between the forward and backward rapidity regions is {approx}20 deg. for the central and 10 deg. for the midperipheral collisions. The hydrodynamic expansion of a torqued fireball leads to a torqued collective flow, yielding, in turn, torqued principal axes of the transverse-momentum distributions at different rapidities. We propose experimental measures, based on cumulants involving particles in different rapidity regions, which should allow for a quantitative determination of the effect from the data. To estimate the nonflow contributions from resonance decays we run Monte Carlo simulations with therminator, a thermal heavy-ion generator. If the event-by-event torque effect is found in the data, it will support the assumptions concerning the fluctuations in the early stage of the fireball formation, as well as the hypothesis of the asymmetric rapidity shape of the emission functions of the moving sources in the nucleus-nucleus collisions.

Bozek, Piotr [H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow (Poland); Institute of Physics, Rzeszow University, PL-35959 Rzeszow (Poland); Broniowski, Wojciech [H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow (Poland); Institute of Physics, Jan Kochanowski University, PL-25406 Kielce (Poland); Moreira, Joao [Centro de Fisica Computacional, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

2011-03-15

364

Lunar and Solar Torques on the Oceanic Tides  

NASA Technical Reports Server (NTRS)

A general framework for calculating lunar and solar torques on the oceanic tides is developed in terms of harmonic constituents. Axial torques and their associated angular momentum and earth-rotation variations are deduced from recent satellite-altimeter and satellite-tracking tide solutions. Torques on the prograde components of the tide produce the familiar secular braking of the rotation rate. The estimated secular acceleration is approximately -1300 sec/century(sup 2) (less 4% after including atmospheric tides); the implied rate of change in the length of day is 2.28 milliseconds/century. Torques on the retrograde components of the tide produce periodic rotation variations at twice the tidal frequency. Interaction torques, e.g. solar torques on lunar tides, generate a large suite of rotation-rate variations at sums and differences of the original tidal frequencies. These are estimated for periods from 18.6 years to quarter-diurnal. At subdaily periods the angular momentum variations are 5 to 6 orders of magnitude smaller than the variations caused by ocean tidal currents.

Ray, Richard D.; Bills, Bruce G.; Chao, Benjamin Fong

1998-01-01

365

Torque Oscillations of Synchronous Motors Under Starting Conditions.  

NASA Astrophysics Data System (ADS)

Salient pole synchronous motors develop an average torque and an oscillatory torque at twice slip frequency during starting. If coupled to a complex mechanical system, with resonances in the oscillatory torque frequency range, severe stresses may result in shafts, gearing and coupling. The objective of this research was to develop motor and mechanical system models which can be computerized to analyze the torsional response of a motor with given parameters on a specific, previously designed, mechanical system, and if necessary, avoid the use of motors that yield excessive values of stress as to take steps to mitigate the oscillation magnitudes. In addition to the development of models and algorithms to calculate performance and predict possible failure, such as deformation of components during starting, the effect of the magnitude of external field resistance, during starting, on peak oscillatory torque magnitudes, slip ring voltages, average torque, and the slip at which maximum torque occurs is as investigated. It was found that the value of external field resistance used had a marked effect on these quantities.

de La Ree Lopez, Jaime

366

Negative Thrust and Torque Characteristics of an Adjustable-Pitch Metal Propeller  

NASA Technical Reports Server (NTRS)

This report presents the results of a series of negative thrust and torque measurements made with a 4 foot diameter model of a conventional aluminum-alloy propeller. The tests were made in the 20-foot propeller-research tunnel of the National Advisory Committee for Aeronautics. The results show that the negative thrust is considerably affected by the shape and size of the body behind the propeller, that the maximum negative thrust increases with decrease in blade-angle setting, and that the drag of a locked propeller may be greatly reduced by feathering it into the wind. Several examples of possible applications of the data are given.

Hartman, Edwin P

1934-01-01

367

Optimum torque determination and selection of rotary shouldered drill collar connections  

E-print Network

Torque Values Average Shoulder. Stress Average Shoulder Force 35 37 LIST OF FIGURES Figure Page Location of areas affecting connection performance. Location of sections used to calculate section moduli. Effect of make-up on pin root stress.... Strain gage locations. 17 Test setup. Pin end of collar sub ready for testing. 19 8 Make-up test. Close ? up of make-up test. 20 20 10 Bending test, Close-up of bending test. Transducer locations. 22 22 23 12 Beam model. 30 13 Stress...

Marlow, Roy Stone

2012-06-07

368

Effects of rotational speed and feed rate on temperature rise, feed force and cutting torque when drilling bovine cortical bone  

NASA Astrophysics Data System (ADS)

Surgical procedures that affect the human bone structure often entail drilling operations of bone. The post-operative evolution of these interventions is conditioned largely by the damage generated during the operation. The aim of this study was to determine clearly the influence of the cutting conditions on temperatures and forces when drilling bovine cortical bone, in the interests of further optimization of cutting conditions to minimize the generated damage. The infrared thermography technique and a piezoelectric dynamometer were employed as measurement devices. It was observed that the main parameter affecting temperatures was the feed per tooth. The temperatures obtained were lower when drilling with high feed per tooth, even though an opposite effect was noticed on the feed force and torque, with an increase of them. From the experimental results, prediction models of temperature rise, feed force and cutting torque were created, in order to predict the response based on the selected cutting conditions.

Soriano, J.; Iriarte, L. M.; Eguren, J. A.; Aristimuño, P.; Garay, A.; Arrazola, P. J.

2012-04-01

369

Report on Toyota/Prius Motor Torque-Capability, Torque-Property, No-Load Back EMF, and Mechanical Losses  

SciTech Connect

In today's hybrid vehicle market, the Toyota Prius drive system is currently considered the leader in electrical, mechanical, and manufacturing innovations. It is significant that in today's marketplace, Toyota is able to manufacture and sell the vehicle for a profit. This project's objective is to test the torque capability of the 2004 Prius motor and to analyze the torque properties relating to the rotor structure. The tested values of no-load back electromotive force (emf) and mechanical losses are also presented.

Hsu, J.S.

2004-09-30

370

Spin-orbit torques in L 10-FePt /Pt thin films driven by electrical and thermal currents  

NASA Astrophysics Data System (ADS)

Using the linear response formalism, we compute from first principles the spin-orbit torque (SOT) in a system of two layers of L1 0-FePt (001 ) deposited on an fcc Pt(001) substrate of varying thickness. We find that at room temperature the values of the SOTs that are even and odd with respect to magnetization generally lie in the range of values measured and computed for Co/Pt bilayers. We also observe that the even SOT is much more robust with respect to changing the number of layers in the substrate, and as a function of energy it follows the general trend of the even SOT exerted by the spin Hall current in fcc Pt. The odd torque, on the other hand, is strongly affected by modification of the electronic structure for a specific energy window in the limit of very thin films. Moreover, taking the system at hand as an example, we compute the values of the thermal spin-orbit torque (TSOT). We predict that the gradients of temperature which can be experimentally created in this type of system will cause a detectable torque on the magnetization. We also underline the correlation between the even TSOT and the spin Nernst effect, thus motivating a more intensive experimental effort aimed at an observation of both phenomena.

Géranton, Guillaume; Freimuth, Frank; Blügel, Stefan; Mokrousov, Yuriy

2015-01-01

371

Implementation of a New Torque and Flux Controllers for Direct Torque Control (DTC) of Induction Machine Utilizing Digital Signal Processor (DSP) and Field Programmable Gate Arrays (FPGA)  

Microsoft Academic Search

This paper presents the simulation and experimental results of a new torque and flux controllers for the direct torque control (DTC) of induction motor drives. The controllers provide a simple solution to the variable switching frequency and high torque ripples problems encountered in the hysteresis-based DTC drives. The controllers operate based on the comparison between the compensated error signals and

C. L. Toh; N. R. N. Idris; A. H. M. Yatim; N. D. Muhamad; M. Elbuluk

2005-01-01

372

Ankle and hip postural strategies defined by joint torques  

NASA Technical Reports Server (NTRS)

Previous studies have identified two discrete strategies for the control of posture in the sagittal plane based on EMG activations, body kinematics, and ground reaction forces. The ankle strategy was characterized by body sway resembling a single-segment-inverted pendulum and was elicited on flat support surfaces. In contrast, the hip strategy was characterized by body sway resembling a double-segment inverted pendulum divided at the hip and was elicited on short or compliant support surfaces. However, biomechanical optimization models have suggested that hip strategy should be observed in response to fast translations on a flat surface also, provided the feet are constrained to remain in contact with the floor and the knee is constrained to remain straight. The purpose of this study was to examine the experimental evidence for hip strategy in postural responses to backward translations of a flat support surface and to determine whether analyses of joint torques would provide evidence for two separate postural strategies. Normal subjects standing on a flat support surface were translated backward with a range of velocities from fast (55 cm/s) to slow (5 cm/s). EMG activations and joint kinematics showed pattern changes consistent with previous experimental descriptions of mixed hip and ankle strategy with increasing platform velocity. Joint torque analyses revealed the addition of a hip flexor torque to the ankle plantarflexor torque during fast translations. This finding indicates the addition of hip strategy to ankle strategy to produce a continuum of postural responses. Hip torque without accompanying ankle torque (pure hip strategy) was not observed. Although postural control strategies have previously been defined by how the body moves, we conclude that joint torques, which indicate how body movements are produced, are useful in defining postural control strategies. These results also illustrate how the biomechanics of the body can transform discrete control patterns into a continuum of postural corrections.

Runge, C. F.; Shupert, C. L.; Horak, F. B.; Zajac, F. E.; Peterson, B. W. (Principal Investigator)

1999-01-01

373

Sowing date, transplanting, plant density and nitrogen fertilization affect indigo production from Isatis species in a Mediterranean region of Spain  

Microsoft Academic Search

The increasing interest in natural products from a renewable source has encouraged growers to reintroduce indigo-producing crops into the European agriculture. We studied agronomic conditions (sowing date, plant density, nitrogen fertilization, irrigation rate, seedling transplanting) influencing production of the blue pigment indigo, from Isatis tinctoria and I. indigotica crops in a Mediterranean region of Spain (Valencia). I. tinctoria was more

Ester Sales; Rodolphe Kanhonou; Carlos Baixauli; Alfonso Giner; David Cooke; Kerry Gilbert; Isabel Arrillaga; Juan Segura; Roc Ros

2006-01-01

374

Lipase production from a novel thermophilic Bacillus sp.: application of Plackett-Burman design for evaluating culture conditions affecting enzyme formation.  

PubMed

A novel thermophilic Bacillus sp. capable of producing lipase was locally isolated. Phylogenetic analysis based on 16SrDNA sequence revealed its close relationship to Bacillus thermoleovorans. Plackett-Burman experimental design was used to evaluate cultural conditions affecting lipase production process. Fifteen variables and four dummy variables were examined in the experimental design. Tween 80, temperature, olive oil, aeration, beef extract and inoculum age were found to be the highest positive significant variables affecting lipase activity, whereas pH and calcium chloride were the highest negative significant variables. Moreover, Tween 80, temperature and olive oil positively affected lipase specific activity. On the other hand, gum arabic, inoculum size and calcium chloride had the highest negative effect on lipase specific activity. This study would improve the further optimization steps on the bioprocess development track. PMID:12708824

Abdel-Fattah, Yasser R; Soliman, Nadia A; Gaballa, Ahmed A; Sabry, Soraya A; El-Diwany, Ahmed I

2002-01-01

375

Results and Analysis from Space Suit Joint Torque Testing  

NASA Technical Reports Server (NTRS)

A space suit's mobility is critical to an astronaut's ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. Mobility can be broken down into two parts: range of motion (ROM) and torque. These two measurements describe how the suit moves and how much force it takes to move. Two methods were chosen to define mobility requirements for the Constellation Space Suit Element (CSSE). One method focuses on range of motion and the second method centers on joint torque. A joint torque test was conducted to determine a baseline for current advanced space suit joint torques. This test utilized the following space suits: Extravehicular Mobility Unit (EMU), Advanced Crew Escape Suit (ACES), I-Suit, D-Suit, Enhanced Mobility (EM)- ACES, and Mark III (MK-III). Data was collected data from 16 different joint movements of each suit. The results were then reviewed and CSSE joint torque requirement values were selected. The focus of this paper is to discuss trends observed during data analysis.

Matty, Jennifer

2010-01-01

376

Real-time brake torque estimation for internal combustion engines  

NASA Astrophysics Data System (ADS)

Presented is a real-time engine brake torque estimation model where the instantaneous measured engine speed serves as the model input. The model is comprised of notch filters executed in the crank-angle domain to extract mean engine speed and the nth frequency component from the instantaneous engine speed signal in real-time. Here n denotes the number of engine cylinders. Moreover, the engine brake torque estimation is separated into two parts: steady-state and transient. It will be shown that the nth harmonic (in units of periods per engine cycle) of engine speed and mean engine speed are sufficient to estimate the engine brake torque. The steady-state portion of the model is developed using orthogonal least-squares estimation and results in a model with 15 regressors for our particular case. The transient portion is identified using a time domain identification method. Validation of the engine brake torque model is provided using a computational engine model for a 6-cylinder heavy duty diesel engine. Transient engine speed and torque conditions in the presence of sensor noise are evaluated as well as cylinder power imbalance scenarios.

Franco, Javier; Franchek, Matthew A.; Grigoriadis, Karolos

2008-02-01

377

Acceleration and torque feedback for robotic control - Experimental results  

NASA Technical Reports Server (NTRS)

Gross motion control of robotic manipulators typically requires significant on-line computations to compensate for nonlinear dynamics due to gravity, Coriolis, centripetal, and friction nonlinearities. One controller proposed by Luo and Saridis avoids these computations by feeding back joint acceleration and torque. This study implements the controller on a Puma 600 robotic manipulator. Joint acceleration measurement is obtained by measuring linear accelerations of each joint, and deriving a computationally efficient transformation from the linear measurements to the angular accelerations. Torque feedback is obtained by using the previous torque sent to the joints. The implementation has stability problems on the Puma 600 due to the extremely high gains inherent in the feedback structure. Since these high gains excite frequency modes in the Puma 600, the algorithm is modified to decrease the gain inherent in the feedback structure. The resulting compensator is stable and insensitive to high frequency unmodeled dynamics. Moreover, a second compensator is proposed which uses acceleration and torque feedback, but still allows nonlinear terms to be fed forward. Thus, by feeding the increment in the easily calculated gravity terms forward, improved responses are obtained. Both proposed compensators are implemented, and the real time results are compared to those obtained with the computed torque algorithm.

Mclnroy, John E.; Saridis, George N.

1990-01-01

378

Position Sensorless Vector Control for Permanent Magnet Synchronous Motors Based on Maximum Torque Control Frame  

NASA Astrophysics Data System (ADS)

High efficiency drive can be achieved by the maximum torque-per-ampere (MTPA) control which used reluctance torque effectively. However, the calculations for estimating rotor position and for controlling the d-axis current are required. The motor parameters of inductance etc. that are easily affected by magnetic saturation are included in those calculations. This paper proposes a new MTPA control method, which is robust against changes of motor parameters caused by magnetic saturation. In addition, complex calculation for d-axis current or reference to the table is not necessary. In this method, we define a novel coordinate frame, which has one axis aligned with the current vector of the MTPA control, and estimate the frame directly. Because the parameter Lqm for estimating the frame is less affected by the magnetic saturation than the conventional Lq, the effect of magnetic saturation on the position estimation can be greatly suppressed. First, an extended electromotive force model based on the proposed frame and a parameter Lqm for an estimation of the frame are derived. Next, the effectiveness of this proposed method is confirmed by simulations and experiments.

Hida, Hajime; Tomigashi, Yoshio; Kishimoto, Keiji

379

How does co-product handling affect the carbon footprint of milk? Case study of milk production in New Zealand and Sweden  

Microsoft Academic Search

Purpose  This paper investigates different methodologies of handling co-products in life cycle assessment (LCA) or carbon footprint\\u000a (CF) studies. Co-product handling can have a significant effect on final LCA\\/CF results, and although there are guidelines\\u000a on the preferred order for different methods for handling co-products, no agreed understanding on applicable methods is available.\\u000a In the present study, the greenhouse gases (GHG)

Anna Flysjö; Christel Cederberg; Maria Henriksson; Stewart Ledgard

2011-01-01

380

Asymmetric ferromagnetic resonance, universal Walker breakdown, and counterflow domain wall motion in the presence of multiple spin-orbit torques  

NASA Astrophysics Data System (ADS)

We study the motion of several types of domain wall profiles in spin-orbit coupled magnetic nanowires and also the influence of spin-orbit interaction on the ferromagnetic resonance of uniform magnetic films. Whereas domain wall motion in systems without correlations between spin space and real space is not sensitive to the precise magnetization texture of the domain wall, spin-orbit interactions break the equivalence between such textures due to the coupling between the momentum and spin of the electrons. In particular, we extend previous studies by fully considering not only the fieldlike contribution from the spin-orbit torque, but also the recently derived Slonczewski-like spin-orbit torque. We show that the latter interaction affects both the domain wall velocity and the Walker breakdown threshold nontrivially, which suggests that it should be accounted for in experimental data analysis. We find that the presence of multiple spin-orbit torques may render the Walker breakdown universal in the sense that the threshold is completely independent on the material-dependent Gilbert damping ?, nonadiabaticity ?, and the chirality ? of the domain wall. We also find that domain wall motion against the current injection is sustained in the presence of multiple spin-orbit torques and that the wall profile will determine the qualitative influence of these different types of torques (e.g., fieldlike and Slonczewski-like). In addition, we consider a uniform ferromagnetic layer under a current bias, and find that the resonance frequency becomes asymmetric against the current direction in the presence of Slonczewski-like spin-orbit coupling. This is in contrast with those cases where such an interaction is absent, where the frequency is found to be symmetric with respect to the current direction. This finding shows that spin-orbit interactions may offer additional control over pumped and absorbed energy in a ferromagnetic resonance setup by manipulating the injected current direction.

Linder, Jacob; Alidoust, Mohammad

2013-08-01

381

40 CFR 63.5994 - How do I conduct tests and procedures for tire production affected sources?  

Code of Federal Regulations, 2013 CFR

...to determine the mass percent of HAP in cements and solvents. To determine the HAP content in the cements and solvents used at your tire production...for determining the HAP content of your cements and solvents. Other reasonable...

2013-07-01

382

40 CFR 63.5994 - How do I conduct tests and procedures for tire production affected sources?  

Code of Federal Regulations, 2012 CFR

...to determine the mass percent of HAP in cements and solvents. To determine the HAP content in the cements and solvents used at your tire production...for determining the HAP content of your cements and solvents. Other reasonable...

2012-07-01

383

40 CFR 63.5994 - How do I conduct tests and procedures for tire production affected sources?  

Code of Federal Regulations, 2011 CFR

...to determine the mass percent of HAP in cements and solvents. To determine the HAP content in the cements and solvents used at your tire production...for determining the HAP content of your cements and solvents. Other...

2011-07-01

384

40 CFR 63.5994 - How do I conduct tests and procedures for tire production affected sources?  

Code of Federal Regulations, 2014 CFR

...to determine the mass percent of HAP in cements and solvents. To determine the HAP content in the cements and solvents used at your tire production...for determining the HAP content of your cements and solvents. Other reasonable...

2014-07-01

385

40 CFR 63.5994 - How do I conduct tests and procedures for tire production affected sources?  

Code of Federal Regulations, 2010 CFR

...to determine the mass percent of HAP in cements and solvents. To determine the HAP content in the cements and solvents used at your tire production...for determining the HAP content of your cements and solvents. Other...

2010-07-01

386

40 CFR Table 4 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the Source...  

Code of Federal Regulations, 2010 CFR

...National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table...Emission point Emission point compliance option Emission, work practice, and equipment standards Monitoring...

2010-07-01

387

40 CFR Table 3 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the...  

Code of Federal Regulations, 2010 CFR

...National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table...Emission point Emission point compliance option Emission, work practice, and equipment standards Monitoring...

2010-07-01

388

Estimating benthic secondary production from aquatic insect emergence in streams affected by mountaintop removal coal mining, West Virginia USA  

EPA Science Inventory

Mountaintop removal and valley fill (MTR/VF) coal mining recountours the Appalachian landscape, buries headwater stream channels, and degrades downstream water quality. The goal of this study was to compare benthic community production estimates, based on seasonal insect emergen...

389

40 CFR Table 4 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the Source...  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 4 Table 4 to Subpart III of Part 63—Compliance Requirements for...

2012-07-01

390

40 CFR Table 4 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the Source...  

Code of Federal Regulations, 2013 CFR

...AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 4 Table 4 to Subpart III of Part 63—Compliance Requirements for...

2013-07-01

391

40 CFR Table 3 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the...  

Code of Federal Regulations, 2011 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 3 Table 3 to Subpart III of Part 63—Compliance Requirements for...

2011-07-01

392

40 CFR Table 3 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the...  

Code of Federal Regulations, 2014 CFR

...AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 3 Table 3 to Subpart III of Part 63—Compliance Requirements for...

2014-07-01

393

40 CFR Table 3 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the...  

Code of Federal Regulations, 2013 CFR

...AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 3 Table 3 to Subpart III of Part 63—Compliance Requirements for...

2013-07-01

394

40 CFR Table 4 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the Source...  

Code of Federal Regulations, 2011 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 4 Table 4 to Subpart III of Part 63—Compliance Requirements for...

2011-07-01

395

40 CFR Table 3 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the...  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 3 Table 3 to Subpart III of Part 63—Compliance Requirements for...

2012-07-01

396

40 CFR Table 4 to Subpart III of... - Compliance Requirements for Slabstock Foam Production Affected Sources Complying With the Source...  

Code of Federal Regulations, 2014 CFR

...AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 4 Table 4 to Subpart III of Part 63—Compliance Requirements for...

2014-07-01

397

Water discharge affects Atlantic salmon Salmo salar smolt production: a 27 year study in the River Orkla, Norway.  

PubMed

A model that explains 48% of the annual variation in Atlantic salmon Salmo salar smolt production in the River Orkla, Norway, has been established. This variation could be explained by egg deposition, minimum daily discharge during the previous winter and minimum weekly discharge during the summer 3 years before smolt migration. All coefficients in the model were positive, which indicates that more eggs and higher minimum discharge levels during the winter before smolt migration and the summer after hatching benefit smolt production. Hence, when the spawning target of the river is reached, the minimum levels of river discharge, in both winter and summer, are the main bottlenecks for the parr survival, and hence for smolt production. The River Orkla was developed for hydropower production in the early 1980s by the construction of four reservoirs upstream of the river stretch accessible to S. salar. Although no water has been removed from the catchment, the dynamics of water flow has been altered, mainly by increasing discharges during winter and reducing spring floods. In spite of the higher than natural winter discharges, minimum winter discharge is still a determinant of smolt production. Hence, in regulated rivers, the maintenance of discharges to ensure that they are as high as possible during dry periods is an important means of securing high S. salar smolt production. PMID:25418585

Hvidsten, N A; Diserud, O H; Jensen, A J; Jensås, J G; Johnsen, B O; Ugedal, O

2015-01-01

398

Heat engine and electric motor torque distribution strategy for a hybrid electric vehicle  

DOEpatents

A method is provided for controlling a power train system for a hybrid electric vehicle. The method includes a torque distribution strategy for controlling the engine and the electric motor. The engine and motor commands are determined based upon the accelerator position, the battery state of charge and the amount of engine and motor torque available. The amount of torque requested for the engine is restricted by a limited rate of rise in order to reduce the emissions from the engine. The limited engine torque is supplemented by motor torque in order to meet a torque request determined based upon the accelerator position.

Boberg, Evan S. (Hazel Park, MI); Gebby, Brian P. (Hazel Park, MI)

1999-09-28

399

Radiation torque on nonspherical particles in the transition matrix formalism  

NASA Astrophysics Data System (ADS)

The torque exerted by radiation on small particles is recognized to have a considerable relevance, e.g., on the dynamics of cosmic dust grains and for the manipulation of micro and nanoparticles under controlled conditions. In the present paper we derive, in the transition matrix formalism, the radiation torque applied by a plane polarized wave on nonspherical particles. In case of circularly polarized waves impinging on spherical particles our equations reproduce the findings of Marston and Crichton [Phys. Rev. A 30, 2508 2516 (1984)]. Our equations were applied to calculate the torque on a few model particles shaped as aggregates of identical spheres, both axially symmetric and lacking any symmetry, and the conditions for the stability of the induced rotational motion are discussed.

Borghese, Ferdinando; Denti, Paolo; Saija, Rosalba; Iatì, Maria A.

2006-10-01

400

Reduction of torque pulsation of Stirling engine-compressor system  

NASA Astrophysics Data System (ADS)

The refrigerant compressor driven by a Stirling engine is built into the heat pump system. The Stirling engine-compressor unit generates rolling vibration due to a fluctuation in combined torque. In order to reduce the rolling vibration, the torque characteristics and the linkage construction of the crankshafts are investigated. The investigation was undertaken for the beta-displacer-type and the two-piston-type configurations. In addition to the Stirling engine, a four-stroke internal combustion engine was considered as a reference. When the Stirling engine drives the compressor, the vibration characteristics depend on its linkage construction. The combined torque which caused the rolling vibration was calculated on the Stirling engine-compressor unit.

Koda, Toshihide; Fujiwara, Michio; Suganami, Takuya

401

Study of ball bearing torque under elastohydrodynamic lubrication  

NASA Technical Reports Server (NTRS)

Spinning and rolling torques were measured in an angular-contact ball bearing with and without a cage under several lubrication regimes in a modified NASA spinning torque apparatus. Two lubricants were used, a di-2 ethylhexyl sebacate and a synthetic paraffinic oil, at shaft speeds of 1000, 2000, and 3000 rpm and bearing loads from 10 lbs to 90 lbs. An analytical model was developed from previous spinning friction models to include rolling with spinning under lubrication regimes from thin film to flooded conditions. The bearing torque values have a wide variation, under any condition of speed and load, depending on the amount of lubricant present in the bearing. The analytical model compared favorably with experimental results under several lubrication regimes.

Townsend, D. P.; Allen, C. W.; Zaretsky, E. V.

1973-01-01

402

Study of ball bearing torque under elastohydrodynamic lubrication  

NASA Technical Reports Server (NTRS)

Spinning and rolling torques were measured in an angular-contact ball bearing with and without a cage under several lubrication regimes in a modified NASA spinning torque apparatus. Two lubricants were used - a di-2 ethylhexyl sebacate and a synthetic paraffinic oil, at shaft speeds of 1000, 2000, and 3000 rpm and bearing loads from 45 newtons (10 lb) to 403 newtons (90 lb). An analytical model was developed from previous spinning friction models to include rolling with spinning under lubrication regimes from thin film to flooded conditions. The bearing torque values have a wide variation, under any condition of speed and load, depending on the amount of lubricant present in the bearing. The analytical model compared favorably with experimental results under several lubrication regimes.

Townsend, D. P.; Zaretsky, E. V.; Allen, C. W.

1973-01-01

403

Dynamic evaluation on friction torque of bearing for space use  

NASA Astrophysics Data System (ADS)

As the important index of evaluating the operational sensitivity of the rolling bearings, the friction torque of bearing for space using influences the signal transferring accuracy and the system stability of the spacecraft directly. It is difficult to do the large number of tests based on the particularity of the bearing for space using. Therefore, considering the limitation of the statistical principle, a dynamic evaluation model called the grey bootstrap modeling (GBM) is proposed in the paper to dynamically evaluate the friction torque of bearing for space using. The test shows under the condition of the minimum of the mean uncertainty, choosing the suitable rolling factor, the number of resampling and the confidence level, the GBM can describe the fluctuation interval of the friction torque on-line much better, and also can separate the systematic error. So, the GBM has the better performance of dynamic forecasting and its liability is quite high.

Chen, Shichao; Xia, Xintao; Wang, Zhongyu; Wang, Changxing

2008-10-01

404

Controlled torque on superparamagnetic beads for functional biosensors.  

PubMed

We demonstrate that a rotating magnetic field can be used to apply a controlled torque on superparamagnetic beads which leads to a tunable bead rotation frequency in fluid. Smooth rotation is obtained for field rotation frequencies many orders of magnitude higher than the bead rotation frequency. A quantitative model is developed, based on results from a comprehensive set of experiments at different field strengths and frequencies. At low frequencies (<10Hz), rotation is due to a small permanent magnetic moment in the bead. At high frequencies (kHz-MHz), the torque results from a phase lag between the applied field and the induced magnetic moment, caused by the non-zero relaxation time of magnetic nanoparticles in the bead. The control of torque and rotation will enable novel functional assays in bead-based biosensors. PMID:19022651

Janssen, X J A; Schellekens, A J; van Ommering, K; van Ijzendoorn, L J; Prins, M W J

2009-03-15

405

Advanced torque converters for robotics and space applications  

NASA Technical Reports Server (NTRS)

This report describes the results of the evaluation of a novel torque converter concept. Features of the concept include: (1) automatic and rapid adjustment of effective gear ratio in response to changes in external torque (2) maintenance of output torque at zero output velocity without loading the input power source and (3) isolation of input power source from load. Two working models of the concept were fabricated and tested, and a theoretical analysis was performed to determine the limits of performance. It was found that the devices are apparently suited to certain types of tool driver applications, such as screwdrivers, nut drivers and valve actuators. However, quantiative information was insufficient to draw final conclusion as to robotic applications.

1985-01-01

406

Dietary inclusion of diallyl disulfide, yucca powder, calcium fumarate, an extruded linseed product, or medium-chain fatty acids does not affect methane production in lactating dairy cows  

Microsoft Academic Search

Two similar experiments were conducted to assess the effect of diallyl disulfide (DADS), yucca powder (YP), calcium fumarate (CAFU), an extruded linseed product (UNSAT), or a mixture of capric and caprylic acid (MCFA) on methane production, energy balance, and dairy cow performance. In experiment 1, a control diet (CON1) and diets supplemented with 56mg of DADS\\/kg of dry matter (DM),

S. M. van Zijderveld; J. Dijkstra; H. B. Perdok; J. R. Newbold; W. J. J. Gerrits

2011-01-01

407

Fluidized bed combustion by?product treatment and leaching of acid soil affects growth and boron acquisition of maize  

Microsoft Academic Search

Fluidized bed combustion bottom ash (FBCBA) from coal burning power plants often contain substances that detrimentally affect plant growth [(e.g., boron (B)] when applied to soil. Leaf symptoms similar to B toxicity appeared when maize (Zea mays L.) was grown during Year?1 of a field experiment where FBCBA was incorporated (6,790 and 13,580 kg ha) in an acidic soil (Aquic

M. Zaifnejad; K. D. Ritchey; R. B. Clark; V. C. Baligar; D. C. Martens

1998-01-01

408

The ROK Family Regulator Rok7B7 Pleiotropically Affects Xylose Utilization, Carbon Catabolite Repression, and Antibiotic Production in Streptomyces coelicolor  

PubMed Central

Members of the ROK family of proteins are mostly transcriptional regulators and kinases that generally relate to the control of primary metabolism, whereby its member glucose kinase acts as the central control protein in carbon control in Streptomyces. Here, we show that deletion of SCO6008 (rok7B7) strongly affects carbon catabolite repression (CCR), growth, and antibiotic production in Streptomyces coelicolor. Deletion of SCO7543 also affected antibiotic production, while no major changes were observed after deletion of the rok family genes SCO0794, SCO1060, SCO2846, SCO6566, or SCO6600. Global expression profiling of the rok7B7 mutant by proteomics and microarray analysis revealed strong upregulation of the xylose transporter operon xylFGH, which lies immediately downstream of rok7B7, consistent with the improved growth and delayed development of the mutant on xylose. The enhanced CCR, which was especially obvious on rich or xylose-containing media, correlated with elevated expression of glucose kinase and of the glucose transporter GlcP. In liquid-grown cultures, expression of the biosynthetic enzymes for production of prodigionines, siderophores, and calcium-dependent antibiotic (CDA) was enhanced in the mutant, and overproduction of prodigionines was corroborated by matrix-assisted laser desorption ionization–time-of-flight analysis. These data present Rok7B7 as a pleiotropic regulator of growth, CCR, and antibiotic production in Streptomyces. PMID:23292782

?wi?tek, Magdalena A.; Gubbens, Jacob; Bucca, Giselda; Song, Eunjung; Yang, Yung-Hun; Laing, Emma; Kim, Byung-Gee; Smith, Colin P.

2013-01-01

409

The ROK family regulator Rok7B7 pleiotropically affects xylose utilization, carbon catabolite repression, and antibiotic production in streptomyces coelicolor.  

PubMed

Members of the ROK family of proteins are mostly transcriptional regulators and kinases that generally relate to the control of primary metabolism, whereby its member glucose kinase acts as the central control protein in carbon control in Streptomyces. Here, we show that deletion of SCO6008 (rok7B7) strongly affects carbon catabolite repression (CCR), growth, and antibiotic production in Streptomyces coelicolor. Deletion of SCO7543 also affected antibiotic production, while no major changes were observed after deletion of the rok family genes SCO0794, SCO1060, SCO2846, SCO6566, or SCO6600. Global expression profiling of the rok7B7 mutant by proteomics and microarray analysis revealed strong upregulation of the xylose transporter operon xylFGH, which lies immediately downstream of rok7B7, consistent with the improved growth and delayed development of the mutant on xylose. The enhanced CCR, which was especially obvious on rich or xylose-containing media, correlated with elevated expression of glucose kinase and of the glucose transporter GlcP. In liquid-grown cultures, expression of the biosynthetic enzymes for production of prodigionines, siderophores, and calcium-dependent antibiotic (CDA) was enhanced in the mutant, and overproduction of prodigionines was corroborated by matrix-assisted laser desorption ionization-time-of-flight analysis. These data present Rok7B7 as a pleiotropic regulator of growth, CCR, and antibiotic production in Streptomyces. PMID:23292782

?wi?tek, Magdalena A; Gubbens, Jacob; Bucca, Giselda; Song, Eunjung; Yang, Yung-Hun; Laing, Emma; Kim, Byung-Gee; Smith, Colin P; van Wezel, Gilles P

2013-03-01

410

Synchronization of spin torque nano-oscillators through dipolar interactions  

SciTech Connect

In an array of spin-torque nano-oscillators (STNOs) that combine a perpendicular polarized fixed layer with strong in-plane anisotropy in the free layers, magnetic dipolar interactions can effectively phase-lock the array, thus further enhancing the power of the output microwave signals. We perform a qualitative analysis of the synchronization of an array based on the Landau-Lifshitz-Gilbert equation, with a spin-transfer torque that assumes strong in-plane anisotropy. Finally, we present the numerical results for four coupled STNOs to provide further evidence for the proposed theory.

Chen, Hao-Hsuan, E-mail: d95222014@ntu.edu.tw; Wu, Jong-Ching, E-mail: phjcwu@cc.ncue.edu.tw; Horng, Lance [Department of Physics, National Changhua University of Education, Changhua 500, Taiwan (China); Lee, Ching-Ming [Graduate School of Materials Science, National Yunlin University of Science and Technology, Douliou, 64002, Taiwan (China); Chang, Ching-Ray, E-mail: crchang@phys.ntu.edu.tw; Chang, Jui-Hang [Department of Physics and Center for Quantum Sciences and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

2014-04-07

411

Analysis and simulation of a torque assist automated manual transmission  

NASA Astrophysics Data System (ADS)

The paper presents the kinematic and dynamic analysis of a power-shift automated manual transmission (AMT) characterised by a wet clutch, called assist clutch (ACL), replacing the fifth gear synchroniser. This torque assist mechanism becomes a torque transfer path during gearshifts, in order to overcome a typical dynamic problem of the AMTs, that is the driving force interruption. The mean power contributions during gearshifts are computed for different engine and ACL interventions, thus allowing to draw considerations useful for developing the control algorithms. The simulation results prove the advantages in terms of gearshift quality and ride comfort of the analysed transmission.

Galvagno, E.; Velardocchia, M.; Vigliani, A.

2011-08-01

412

Kinetic Energy Principle And Neoclassical Toroidal Torque In Tokamaks  

SciTech Connect

It is shown that when tokamaks are perturbed the kinetic energy principle is closely related to the neoclassical toroidal torque by the action invariance of particles. Especially when tokamaks are perturbed from scalar pressure equilibria, the imaginary part of the potential energy in the kinetic energy principle is equivalent to the toroidal torque by the Neoclassical Toroidal Viscosity (NTV). A unified description therefore should be made for both physics. It is also shown in this case that the potential energy operator can be self-adjoint and thus the stability calculation can be simplified by minimizing the potential energy

Jong-Kyu Park

2011-11-07

413

PWM Switching Strategy for Torque Ripple Minimization in BLDC Motor  

NASA Astrophysics Data System (ADS)

This paper describes a new PWM switching strategy to minimize the torque ripples in BLDC motor which is based on sensored rotor position control. The scheme has been implemented using a PIC microcontroller to generate a modified Pulse Width Modulation (PWM) signals for driving power inverter bridge. The modified PWM signals are successfully applied to the next up-coming phase current such that its current rise is slightly delayed during the commutation instant. Experimental results show that the current waveforms of the modified PWM are smoother than that in conventional PWM technique. Hence, the output torque exhibits lower ripple contents.

Salah, Wael A.; Ishak, Dahaman; Hammadi, Khaleel J.

2011-05-01

414

A mixture of phytosterols from Dunaliella tertiolecta affects proliferation of peripheral blood mononuclear cells and cytokine production in sheep.  

PubMed

The aim of this study was to investigate the immunomodulatory and anti-inflammatory role of a mixture of phytosterols extracted from the microalga Dunaliella tertiolecta on peripheral blood mononuclear cells (PBMC) isolated from sheep. PBMC were treated to determine cell proliferation and cytokine production with different sterols: ergosterol (E), a mixture of eleven Algae sterols extracted and purified from D. tertiolecta (Algae Extract, AE), a mixture of ergosterol and 7-dehydroporiferasterol extracted and purified from D. tertiolecta (Purified Extract, PE). Cytokine production (TNF-?, IL-6, IL-1?, and IL-10) was evaluated after cell treatment with Concanavalin A (Con A) and lipopolysaccharide (LPS). The mixture of ergosterol and 7-dehydroporiferasterol extracted and purified from D. tertiolecta showed a suppressive effect on cell proliferation, and a reduction of pro-inflammatory cytokines production. Furthermore, a stimulatory effect on the production of the regulatory cytokine IL-10 was found. The immunosuppressive effect exerted by the mixture of ergosterol and 7-dehydroporiferasterol from D. tertiolecta was dose-dependent both in suppressing cell proliferation and in stimulating IL-10 production. Present results showed that the immunomodulatory and anti-inflammatory activities were more apparent in the purified extract characterized by the mixture of ergosterol and 7-dehydroporiferasterol, and might depend on the existence of a synergic effect of the structures of the two phytosterols. Furthermore, findings from our study suggest that the purified extract characterized by the mixture of ergosterol and 7-dehydroporiferasterol from D. tertiolecta could be used to reduce immune reactions resulting from inflammatory diseases in sheep production systems, and could have innovative implications on the modulation of sheep immune system when used as feed supplements. PMID:22985633

Caroprese, Mariangela; Albenzio, Marzia; Ciliberti, Maria Giovanna; Francavilla, Matteo; Sevi, Agostino

2012-11-15

415

Growth control of A431 cells in protein-free medium: Secretory products do not affect cell growth  

Microsoft Academic Search

Summary  A431 cells grew at similar rates in protein-free Coon's modified Ham's F12 medium (PF-C-F12) with and without added bovine\\u000a calf serum. The cells secreted a heparin-binding growth factor and a type-? transforming growth factor, but their growth in\\u000a PF-C-F12 was not affected by these factors, or by DNA synthesis factor from Rhodamine fibrosarcoma, basic fibroblast growth\\u000a factor, insulin, human transferrin,

Yoshishige Masuda; Yoshino Yoshitake; Katsuzo Nishikawa

1988-01-01

416

One Frog, Two Frog, Red Frog, Blue Frog: Factors Affecting Children's Syntactic Choices in Production and Comprehension  

Microsoft Academic Search

Two experiments are reported which examine children's ability to use referential context when making syntactic choices in language production and comprehension. In a recent on-line study of auditory comprehension, Trueswell, Sekerina, Hill, and Logrip (1999) examined children's and adults' abilities to resolve temporary syntactic ambiguities involving prepositional phrases (e.g., “Put the frog on the napkin into ¨”). Although adults and

Felicia Hurewitz; Sarah Brown-Schmidt; Kirsten Thorpe; Lila R. Gleitman; John C. Trueswell

2000-01-01

417

ALTERING THE PHYSICAL ENVIRONMENT AFFECTS GROWTH, MORPHOGENESIS AND ESSENTIAL OIL PRODUCTION IN MENTHA SPICATA L. SHOOTS IN VITRO  

Technology Transfer Automated Retrieval System (TEKTRAN)

Altering the physical environment profoundly alters the growth (fresh weight), morphogenesis (leave, root and shoot numbers) and secondary metabolism [i.e., production of the monoterpene (-)-carvone] of Mentha spicata L. (spearmint) shoots cultured on Murashige and Skoog medium. The type of physica...

418

INCREASED BIOFUEL PRODUCTION IN THE COMING DECADE: TO WHAT EXTENT WILL IT AFFECT GLOBAL FRESHWATER RESOURCES?y  

Microsoft Academic Search

Irrigated agriculture accounts for 70% of global water withdrawals and therefore contributes substantially to global water scarcity. This article focuses on the impact of the increasing demand for biofuel on global water resources in the coming decade. Based on biofuel production projections for 2008 and 2017, it was estimated that currently around 1% of all water withdrawn for irrigation is

JIPPE HOOGEVEEN; JEAN-MARC FAURES; NICK VAN DE GIESSEN

419

Voluntary and involuntary processes affect the production of verbal and non-verbal signals by the human voice.  

PubMed

We argue that a comprehensive model of human vocal behaviour must address both voluntary and involuntary aspects of articulate speech and non-verbal vocalizations. Within this, plasticity of vocal output should be acknowledged and explained as part of the mature speech production system. PMID:25514954

McGettigan, Carolyn; Scott, Sophie Kerttu

2014-12-01

420

Light affects fumonisin production in strains of Fusarium fujikuroi, Fusarium proliferatum, and Fusarium verticillioides isolated from rice.  

PubMed

Three Fusarium species associated with bakanae disease of rice (Fusarium fujikuroi, Fusarium proliferatum, and Fusarium verticillioides) were investigated for their ability to produce fumonisins (FB1 and FB2) under different light conditions, and for pathogenicity. Compared to darkness, the conditions that highly stimulated fumonisin production were yellow and green light in F. verticillioides strains; white and blue light, and light/dark alternation in F. fujikuroi and F. proliferatum strains. In general, all light conditions positively influenced fumonisin production with respect to the dark. Expression of the FUM1 gene, which is necessary for the initiation of fumonisin production, was in accordance with the fumonisin biosynthetic profile. High and low fumonisin-producing F. fujikuroi strains showed typical symptoms of bakanae disease, abundant fumonisin-producing F. verticillioides strains exhibited chlorosis and stunting of rice plants, while fumonisin-producing F. proliferatum strains were asymptomatic on rice. We report that F. fujikuroi might be an abundant fumonisin producer with levels comparable to that of F. verticillioides and F. proliferatum, highlighting the need of deeper mycotoxicological analyses on rice isolates of F. fujikuroi. Our results showed for the first time the influence of light on fumonisin production in isolates of F. fujikuroi, F. proliferatum, and F. verticillioides from rice. PMID:24055868

Mati?, Slavica; Spadaro, Davide; Prelle, Ambra; Gullino, Maria Lodovica; Garibaldi, Angelo

2013-09-16

421

Overexpression of luxS Cannot Increase Autoinducer-2 Production, Only Affect the Growth and Biofilm Formation in Streptococcus suis  

PubMed Central

LuxS/AI-2 quorum sensing (QS) system involves the production of cell signaling molecules via luxS-based autoinducer-2 (AI-2). LuxS has been reported to plays critical roles in regulating various behaviors of bacteria. AI-2 is a byproduct of the catabolism of S-adenosylhomocysteine (SAH) performed by the LuxS and Pfs enzymes. In our previous study, the function of LuxS in AI-2 production was verified in Streptococcus suis (SS). Decreased levels of SS biofilm formation and host-cell adherence as well as an inability to produce AI-2 were observed in bacteria having a luxS mutant gene. In this study, the level of AI-2 activity exhibits a growth-phase dependence with a maximum in late exponential culture in SS. An SS strain that overexpressed luxS was constructed to comprehensively understand the function of AI-2. Overexpressed luxS was not able to increase the level of pfs expression and produce additional AI-2, and the bacteria were slower growing and produced only slightly more biofilm than the wild type. Thus, AI-2 production is not correlated with luxS transcription. luxS expression is constitutive, but the transcription of pfs is perhaps correlated with AI-2 production in SS. PMID:24324385

Wang, Yang; Yi, Li; Zhang, Zhicheng; Fan, Hongjie; Cheng, Xiangchao; Lu, Chengping

2013-01-01

422

The torque dependence of the H-mode power threshold in hydrogen, deuterium and helium plasmas in DIII-D  

SciTech Connect

On DIII-D, the H-mode power threshold has been determined for hydrogen, deuterium and helium plasmas heated by neutral beam injection and/or by electron cyclotron heating and as a function of the applied torque plasmas for plasma configurations in the favourable ion grad-B drift direction. The H-mode threshold power has been determined to increase with input torque for all the main ion species (hydrogen, deuterium and helium). The H-mode threshold power for similar plasma parameters and configurations is the least for deuterium, followed by helium and hydrogen in that order. The plasma geometry also affects the power threshold, which is dependent on the X-point height.

Gohil, P. [General Atomics; Jernigan, T. C. [Oak Ridge National Laboratory (ORNL); Osborne, T.H. [General Atomics, San Diego; Scoville, J. T. [General Atomics, San Diego; Strait, E. J. [General Atomics

2010-01-01

423

Alterations of the in vivo torque-velocity relationship of human skeletal muscle following 30 days exposure to simulated microgravity  

NASA Technical Reports Server (NTRS)

The effect of a continuous 30-d-long 6-deg headdown bedrest (BR) on the force output ability of skeletal muscles was investigated in human subjects by measuring peak angle specific torque of the knee extensor (KE) and knee flexor (KF) muscle groups of both limbs during unilateral efforts at four speeds (0.52. 1.74, 2.97, and 4.19 rad/sec) during eccentric action. It was found that, for the KE muscle group, the headdown BR resulted in decreases, by 19 percent on the average, of peak angle specific torque; on the other hand, the strength of the KF muscles was not altered significantly. A post-BR recovery for 30 days was found to restore muscle strength of the KE muscle group to about 92 percent of the pre-BR values. Changes of strength were not affected by the type of speed of muscle action.

Dudley, Gary A.; Duvoisin, Marc; Convertino, Victor A.; Buchanan, Paul

1989-01-01

424

Studies on Contact Geometry and Limiting Resistant Torque Characteristics of the Variable Torque Slipping Clutch with Skewed Rollers  

NASA Astrophysics Data System (ADS)

A slipping clutch capable of delivering a constant resistant torque is described in this paper. Its principle is based on the resistance to slipping offered by the askew disposed cylindrical rollers rolling and slipping between the two specially shaped races. There are three types of this slipping clutch, namely the Right, Left and Cross Skewing respectively, which are distinguished by the directions of the roller askew arrangement and the rotation of the driving race. As a newly developed engineering surface, the surface of the races is in the spatial line contact with the skewed cylindrical rollers. After the equations of the race surface is established, the contact geometry of the tangency between the roller and races is investigated. This is essential for understanding the clutch properties and furthering the contact stress and EHL analyses. In addition, the analyzing procedure used here is also helpful for the study of other sophisticated line contact problems. Based on the assumptions of the maximum static friction force and the uniform distribution of the applied axial force along the contact line, the limiting torque characteristics are discussed in detail. The analysis of the maximum resistant torque clarifies the existence of self-locking problems under certain design parameters. On the other hand, the analysis of the minimum resistant torque shows how the resistant torque approaches the minimum values with changes of the geometrical parameters. These analyses provide the design principals for this slipping clutch in order to optimize the torque characteristics. The preliminary experiments are conducted with two types out of the three and the results prove those concluded from the theoretical analyses very well.

Feng, Ming; Ono, Kyosuke; Mimura, Kenji

425

Factors affecting hydrogen production from cassava wastewater by a co-culture of anaerobic sludge and Rhodospirillum rubrum.  

PubMed

Series of batch experiments were used to investigate the effects of environmental factors, i.e., total nitrogen and total phosphorus concentrations, initial pH, illumination pattern and stirring conditions on hydrogen production from cassava wastewater by a co-culture of anaerobic sludge and Rhodospirillum rubrum. The maximum of the hydrogen yield of 150.46 and 340.19 mL g-COD(-1) was obtained at the total nitrogen and total phosphorus concentrations of 0.2 and 0.04 M, respectively. An effect of initial pH was investigated at COD:N:P ratio of 100:10:1. Results indicated that an optimum initial pH for hydrogen production was pH 7 with a high hydrogen yield of 158.78 mL g-COD(-1) was obtained. No significantly different (p < 0.05) in the effect of illumination pattern (24 h of light and 12 h dark/light cycle) on hydrogen production were observed under continuous-illumination and periodic-illumination with hydrogen yield of 131.84 and 126.92 mL g-COD(-1), respectively. Therefore, a periodic-illumination was applicable in hydrogen fermentation due to its cost-effective. Hydrogen fermentation with a stirring at 100 rpm provided more effective hydrogen production (164.83 mL g-COD(-1)) than static-fermentation (93.93 mL g-COD(-1)). The major soluble products from hydrogen fermentation were acetic and butyric acids, in the ranges of 28.33-48.30 and 35.23-66.07%, respectively, confirming an ability of a co-culture to produce hydrogen from cassava wastewater. PMID:19093464

Reungsang, Alissara; Sangyoka, Suksaman; Chaiprasert, Pawinee; Imai, Tsuyoshi

2007-10-15

426

Auto-oscillation and narrow spectral lines in spin-torque oscillators based on MgO magnetic tunnel junctions  

Microsoft Academic Search

We demonstrate spin-torque induced coherent auto-oscillation in magnetic tunnel junctions of composition PtMn\\/CoFe\\/Ru\\/CoFeB\\/MgO\\/CoFeB and of low resistance-area product. At the generation threshold, we observe a strong line narrowing down to 6 MHz at 300 K and a dramatic increase in oscillator power, yielding spectrally pure oscillations with extremely low flicker noise. The induced auto-oscillations are observed even at zero applied

T. Devolder; L. Bianchini; Joo-Von Kim; P. Crozat; C. Chappert; S. Cornelissen; M. Op de Beeck; L. Lagae

2009-01-01

427

Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation.  

PubMed

Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylation-related product quality. In this work, different fed-batch processes with two chemically defined proprietary media and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards energy and recombinant product, respectively. Accumulation of by-products such as NH4(+) and lactate as a consequence of unbalanced nutrient supply to cell activities inhibits cell growth. The levels of Leu and Arg in the culture, which relate to cell growth and IgG productivity, need to be well controlled. Amino acids with the highest consumption rates correlate with the most abundant amino acids present in the produced IgG, and thus require sufficient availability during culture. Case-by-case analysis is necessary for understanding the effect of media and process optimization on glycosylation. We found that in certain cases the presence of Man5 glycan can be linked to limitation of UDP-GlcNAc biosynthesis as a result of insufficient extracellular Gln. However, under different culture conditions, high Man5 levels can also result from low ?-1,3-mannosyl-glycoprotein 2-?-N-acetylglucosaminyltransferase (GnTI) and UDP-GlcNAc transporter activities, which may be attributed to high level of NH4+ in the cell culture. Furthermore, galactosylation of the mAb Fc glycans was found to be limited by UDP-Gal biosynthesis, which was observed to be both cell line and cultivation condition-dependent. Extracellular glucose and glutamine concentrations and uptake rates were positively correlated with intracellular UDP-Gal availability. All these findings are important for optimization of fed-batch culture for improving IgG production and directing glycosylation quality. Biotechnol. Bioeng. 2015;112: 521-535. © 2014 Wiley Periodicals, Inc. PMID:25220616

Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian; Wagtberg Sen, Jette; Rasmussen, Søren Kofoed; Kontoravdi, Cleo; Weilguny, Dietmar; Andersen, Mikael Rørdam

2015-03-01

428

Design and testing of a non-intrusive torque measurement system  

E-print Network

This thesis details the initial development of a non-intrusive torque measurement system to measure torque in a rotating driveshaft like those commonly found on internal combustion engine powered irrigation pumping plants. A typical driveshaft used...

Wilson, Edwin Ernest

1998-01-01

429

Torque characteristics of a 122-centimeter butterfly valve with a hydro/pneumatic actuator  

NASA Technical Reports Server (NTRS)

Actuating torque data from field testing of a 122-centimeter (48 in.) butterfly valve with a hydro/pneumatic actuator is presented. The hydraulic cylinder functions as either a forward or a reverse brake. Its resistance torque increases when the valve speeds up and decreases when the valve slows down. A reduction of flow resistance in the hydraulic flow path from one end of the hydraulic cylinder to the other will effectively reduce the hydraulic resistance torque and hence increase the actuating torque. The sum of hydrodynamic and friction torques (combined resistance torque) of a butterfly valve is a function of valve opening time. An increase in the pneumatic actuating pressure will result in a decrease in both the combined resistance torque and the actuator opening torque; however, it does shorten the valve opening time. As the pneumatic pressure increases, the valve opening time for a given configuration approaches an asymptotical value.

Lin, F. N.; Moore, W. I.; Lundy, F. E.

1981-01-01

430

Porcine catabolin stimulates prostaglandin E2 secretion but does not affect intracellular cyclic AMP production in pig synovial fibroblasts.  

PubMed Central

Responses in vitro to partially purified porcine leucocyte catabolin were studied in pig synovial fibroblasts.In serum-free cultures catabolin was found to stimulate secretion of prostaglandin E2 (PGE2) in a time and concentration-dependent manner. The initial stimulation of PGE2 secretion occurred only after a latent interval of six hours. In the same cell line catabolin was found to have no effect on the production of cyclic adenosine monophosphate (cAMP) at times ranging from 30 s to 20 min, even at concentrations up to 15 times greater than that required to promote accelerated release of glycosaminoglycans from cultured bovine nasal cartilage. It is therefore concluded that in pig synovial fibroblasts catabolin evokes a delayed secretion of PGE2 but does not alter cyclic AMP production. PMID:2994582

Carroll, G J

1985-01-01

431

Production Processes Affected Prokaryotic amoA Gene Abundance and Distribution in High-Temperature Petroleum Reservoirs  

Microsoft Academic Search

Although the presence and activity of ammonia-oxidation archaea (AOA) and ammonia-oxidation bacteria (AOB) were observed in thermophilic habitats recently, their existence in the geothermal subterranean oil reservoirs is still not available. This study investigated the abundance and distribution of AOA and AOB in the production waters of high-temperature oil reservoirs by using real-time PCR and phylogenetic analysis based on amoA

Hui Li; Bo-Zhong Mu; Yan Jiang; Ji-Dong Gu

2011-01-01

432

Productive infection of bovine papillomavirus type 2 in the placenta of pregnant cows affected with urinary bladder tumors.  

PubMed

Papillomaviruses (PVs) are believed to be highly epitheliotropic as they usually establish productive infections within stratified epithelia. In vitro, various PVs appear to complete their entire life-cycle in different trophoblastic cell lines. In this study, infection by and protein expression of bovine papillomavirus type 2 (BPV-2) in the uterine and chorionic epithelium of the placenta has been described in four cows suffering from naturally occurring papillomavirus-associated urothelial bladder tumors. E5 oncoprotein was detected both by Western blot analysis and immunohistochemically. It appears to be complexed and perfectly co-localized with the activated platelet-derived growth factor ß receptor (PDGFßR) by laser scanning confocal microscopy. The activated PDGFßR might be involved in organogenesis and neo-angiogenesis rather than in cell transformation during pregnancy. The major capsid protein, L1, believed to be only expressed in productive papillomavirus infection has been detected by Western blot analysis. Immunohistochemical investigations confirmed the presence of L1 protein both in the cytoplasm and nuclei of cells of the uterine and chorionic epithelium. Trophoblastic cells appear to be the major target for L1 protein expression. Finally, the early protein E2, required for viral DNA replication and known to be expressed during a productive infection, has been detected by Western blot and immunohistochemically. Electron microscopic investigations detected viral particles in nuclei of uterine and chorionic epithelium. This study shows that both active and productive infections by BPV-2 in the placenta of pregnant cows can occur in vivo. PMID:22479413

Roperto, Sante; Borzacchiello, Giuseppe; Esposito, Iolanda; Riccardi, Marita; Urraro, Chiara; Lucà, Roberta; Corteggio, Annunziata; Tatè, Rosarita; Cermola, Michele; Paciello, Orlando; Roperto, Franco

2012-01-01

433

Red light and carbon dioxide differentially affect growth, lipid production, and quality in the microalga, Ettlia oleoabundans.  

PubMed

Ettlia oleoabundans, a freshwater unicellular green microalga, was grown under different light qualities ± carbon dioxide-enriched air to determine the combined effects on growth and lipid production of this oleaginous species. Keeping total light intensity constant, when a portion of the cool white was replaced by red, volumetric lipid yield increased 2.8-fold mainly due to the greater yield of oleic acid, a desirable biodiesel precursor. Only 30 min of red light treatment was sufficient to increase lipid yield and quality to the same level as cultures provided red light for >14 days, indicating the potential role of red light in stimulating lipid production of this species. Carbon dioxide enrichment via air sparging enhanced exponential growth, carbon conversion efficiency, and nutrient consumption. Together, these results showed that light quality plays an important role in microalgal lipid production. Adjustment in light quality and gas delivery efficiency with carbon dioxide enrichment improved lipid yield and quality in this and possibly other oleaginous algal species. PMID:25359469

Yang, Ying; Weathers, Pamela

2014-10-31

434

Precipitation timing and magnitude differentially affect aboveground annual net primary productivity in three perennial species in a Chihuahuan Desert grassland.  

PubMed

Plant productivity in deserts may be more directly responsive to soil water availability than to precipitation. However, measurement of soil moisture alone may not be enough to elucidate plant responses to precipitation pulses, as edaphic factors may influence productivity when soil moisture is adequate. The first objective of the study was to determine the responses of the aboveground annual net primary productivity (ANPP) of three perennial species (from different functional groups) in a Chihuahuan Desert grassland to variation in natural precipitation (annual and seasonal) and a 25% increase in seasonal precipitation (supplemental watering in summer and winter). Secondly, ANPP responses to other key environmental and soil parameters were explored during dry, average, and wet years over a 5-yr period. ANPP predictors for each species were dynamic. High ANPP in Dasylirion leiophyllum was positively associated with higher soil NH(4)-N and frequent larger precipitation events, while that in Bouteloua curtipendula was positively correlated with frequent small summer precipitation events with short inter-pulse periods and supplemental winter water. Opuntia phaeacantha was responsive to small precipitation events with short inter-pulse periods. Although several studies have shown ANPP increases with increases in precipitation and soil moisture in desert systems, this was not observed here as a universal predictor of ANPP, particularly in dry years. PMID:19076724

Robertson, Traesha R; Bell, Colin W; Zak, John C; Tissue, David T

2009-01-01

435

Tidal torque induced by orbital decay in compact object binaries  

NASA Astrophysics Data System (ADS)

As we observe in the moon-earth system, tidal interactions in binary systems can lead to angular momentum exchange. The presence of viscosity is generally regarded as the condition for such transfer to happen. In this paper, we show how the orbital evolution can cause a persistent torque between the binary components, even for inviscid bodies. This preferentially occurs at the final stage of coalescence of compact binaries, when the orbit shrinks successively by gravitational waves and plunging on a time-scale shorter than the viscous time-scale. The total orbital energy transferred to the secondary by this torque is ˜10-2 of its binding energy. We further show that this persistent torque induces a differentially rotating quadrupolar perturbation. Specializing to the case of a secondary neutron star, we find that this non-equilibrium state has an associated free energy of 1047-1048 erg, just prior to coalescence. This energy is likely stored in internal fluid motions, with a sizeable amount of differential rotation. By tapping this free energy reservoir, a pre-existing weak magnetic field could be amplified up to a strength of ?1015 G. Such a dynamically driven tidal torque can thus recycle an old neutron star into a magnetar, with possible observational consequences at merger.

Dall'Osso, Simone; Rossi, Elena M.

2013-01-01

436

Stick-Slip Behavior of Torque Converter Clutch  

Microsoft Academic Search

The chief objective of this paper is to study the non-linear behavior of torque converter clutch within the context of an automotive drivetrain. An analytical procedure to determine the pure stick to stick-slip motions is developed based on the linear system analysis. This procedure can efficiently and accurately identify the frequency ranges where linear or non -linear studies are needed.

Chengwu Duan; Rajendra Singh

2005-01-01

437

Magnetic tweezers for the measurement of twist and torque.  

PubMed

Single-molecule techniques make it possible to investigate the behavior of individual biological molecules in solution in real time. These techniques include so-called force spectroscopy approaches such as atomic force microscopy, optical tweezers, flow stretching, and magnetic tweezers. Amongst these approaches, magnetic tweezers have distinguished themselves by their ability to apply torque while maintaining a constant stretching force. Here, it is illustrated how such a "conventional" magnetic tweezers experimental configuration can, through a straightforward modification of its field configuration to minimize the magnitude of the transverse field, be adapted to measure the degree of twist in a biological molecule. The resulting configuration is termed the freely-orbiting magnetic tweezers. Additionally, it is shown how further modification of the field configuration can yield a transverse field with a magnitude intermediate between that of the "conventional" magnetic tweezers and the freely-orbiting magnetic tweezers, which makes it possible to directly measure the torque stored in a biological molecule. This configuration is termed the magnetic torque tweezers. The accompanying video explains in detail how the conversion of conventional magnetic tweezers into freely-orbiting magnetic tweezers and magnetic torque tweezers can be accomplished, and demonstrates the use of these techniques. These adaptations maintain all the strengths of conventional magnetic tweezers while greatly expanding the versatility of this powerful instrument. PMID:24894412

Lipfert, Jan; Lee, Mina; Ordu, Orkide; Kerssemakers, Jacob W J; Dekker, Nynke H

2014-01-01

438

Theory comparison and numerical benchmarking on neoclassical toroidal viscosity torque  

NASA Astrophysics Data System (ADS)

Systematic comparison and numerical benchmarking have been successfully carried out among three different approaches of neoclassical toroidal viscosity (NTV) theory and the corresponding codes: IPEC-PENT is developed based on the combined NTV theory but without geometric simplifications [Park et al., Phys. Rev. Lett. 102, 065002 (2009)]; MARS-Q includes smoothly connected NTV formula [Shaing et al., Nucl. Fusion 50, 025022 (2010)] based on Shaing's analytic formulation in various collisionality regimes; MARS-K, originally computing the drift kinetic energy, is upgraded to compute the NTV torque based on the equivalence between drift kinetic energy and NTV torque [J.-K. Park, Phys. Plasma 18, 110702 (2011)]. The derivation and numerical results both indicate that the imaginary part of drift kinetic energy computed by MARS-K is equivalent to the NTV torque in IPEC-PENT. In the benchmark of precession resonance between MARS-Q and MARS-K/IPEC-PENT, the agreement and correlation between the connected NTV formula and the combined NTV theory in different collisionality regimes are shown for the first time. Additionally, both IPEC-PENT and MARS-K indicate the importance of the bounce harmonic resonance which can greatly enhance the NTV torque when E ×B drift frequency reaches the bounce resonance condition.

Wang, Zhirui; Park, Jong-Kyu; Liu, Yueqiang; Logan, Nikolas; Kim, Kimin; Menard, Jonathan E.

2014-04-01

439

Interaction torque contributes to planar reaching at slow speed  

Microsoft Academic Search

BACKGROUND: How the central nervous system (CNS) organizes the joint dynamics for multi-joint movement is a complex problem, because of the passive interaction among segmental movements. Previous studies have demonstrated that the CNS predictively compensates for interaction torque (INT) which is arising from the movement of the adjacent joints. However, most of these studies have mainly examined quick movements, presumably

Hiroshi Yamasaki; Yoshiyuki Tagami; Hiroyuki Fujisawa; Fumihiko Hoshi; Hiroshi Nagasaki

2008-01-01

440

A Sensorless Direct Torque Control Scheme Suitable for Electric Vehicles  

E-print Network

A Sensorless Direct Torque Control Scheme Suitable for Electric Vehicles Farid Khoucha, Khoudir an Electric Vehicle (EV). The proposed scheme uses an adaptive flux and speed observer that is based on a full is a good candidate for EVs propulsion. Index Terms--Electric vehicle, Induction motor, sensorless drive

Paris-Sud XI, Université de

441

Neuromuscular fatigue following isometric contractions with similar torque time integral.  

PubMed

Torque time integral (TTI) is the combination of intensity and duration of a contraction. The aim of this study was to compare neuromuscular alterations following different isometric sub-maximal contractions of the knee extensor muscles but with similar TTI. Sixteen participants performed 3 sustained contractions at different intensities (25%, 50%, and 75% of Maximal Voluntary Contraction (MVC) torque) with different durations (68.5±33.4?s, 35.1±16.8?s and 24.8±12.9?s, respectively) but similar TTI value. MVC torque, maximal voluntary activation level (VAL), M-wave characteristics and potentiated doublet amplitude were assessed before and immediately after the sustained contractions. EMG activity of the vastus lateralis (VL) and -rectus femoris (RF) muscles was recorded during the sustained contractions. MVC torque reduction was similar in the 3 conditions after the exercise (-23.4±2.7%). VAL decreased significantly in a similar extent (-3.1±1.3%) after the 3 sustained contractions. Potentiated doublet amplitude was similarly reduced in the 3 conditions (-19.7±1.5%), but VL and RF M-wave amplitudes remained unchanged. EMG activity of VL and RF muscles increased in the same extent during the 3 contractions (VL: 54.5±40.4%; RF: 53.1±48.7%). These results suggest that central and peripheral alterations accounting for muscle fatigue are similar following isometric contractions with similar TTI. TTI should be considered in the exploration of muscle fatigue during sustained isometric contractions. PMID:25285471

Rozand, V; Cattagni, T; Theurel, J; Martin, A; Lepers, R

2015-01-01

442

Torque magnetometry of an amorphous-alumina/strontium-titanate interface  

E-print Network

We report torque magnetometry measurements of an oxide heterostructure consisting of an amorphous Al[subscript 2]O[subscript 3] thin film grown on a crystalline SrTiO[subscript 3] substrate (a-AO/STO) by atomic layer ...

Lee, S. W.

443

Optimized Joint-Torques Trajectory Planning for Bipedal Walking Robots  

Microsoft Academic Search

This paper proposes a new method of trajectory planning for biped robots walking on flat terrain. In this approach, the hip and foot trajectories are designed in Cartesian space using polynomial interpolation. The key parameters which define the hip and foot trajectories are searched by genetic algorithm. The objective is to obtain stable walking trajectory with minimized joint-torques requirement. ZMP

Van-huan Dau; Chee-Meng Chewt; Aun-neow Poo

2008-01-01

444

Drive torque actuation in active surge control of centrifugal compressors  

E-print Network

Drive torque actuation in active surge control of centrifugal compressors Jan Tommy Gravdahl , Olav to active surge control is presented for a centrifugal compressor driven by an electrical motor. The main speed Compressor performance control Figure 1: The compression system consists of a centrifugal

Gravdahl, Jan Tommy

445

Theory comparison and numerical benchmarking on neoclassical toroidal viscosity torque  

SciTech Connect

Systematic comparison and numerical benchmarking have been successfully carried out among three different approaches of neoclassical toroidal viscosity (NTV) theory and the corresponding codes: IPEC-PENT is developed based on the combined NTV theory but without geometric simplifications [Park et al., Phys. Rev. Lett. 102, 065002 (2009)]; MARS-Q includes smoothly connected NTV formula [Shaing et al., Nucl. Fusion 50, 025022 (2010)] based on Shaing's analytic formulation in various collisionality regimes; MARS-K, originally computing the drift kinetic energy, is upgraded to compute the NTV torque based on the equivalence between drift kinetic energy and NTV torque [J.-K. Park, Phys. Plasma 18, 110702 (2011)]. The derivation and numerical results both indicate that the imaginary part of drift kinetic energy computed by MARS-K is equivalent to the NTV torque in IPEC-PENT. In the benchmark of precession resonance between MARS-Q and MARS-K/IPEC-PENT, the agreement and correlation between the connected NTV formula and the combined NTV theory in different collisionality regimes are shown for the first time. Additionally, both IPEC-PENT and MARS-K indicate the importance of the bounce harmonic resonance which can greatly enhance the NTV torque when E×B drift frequency reaches the bounce resonance condition.

Wang, Zhirui; Park, Jong-Kyu; Logan, Nikolas; Kim, Kimin; Menard, Jonathan E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Liu, Yueqiang [Euratom/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)] [Euratom/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2014-04-15

446

TORQUE AND DRAG CALCULATIONS IN THREE-DIMENSIONAL WELLBORES  

E-print Network

Torque and drag (T&D) modeling is regarded as extremely helpful in well planning because it helps to predict and prevent drilling problems that might occur during the drilling process. Although T&D software has existed since the 1990s, some...

Prurapark, Ruktai A.

2010-07-14

447

Instantaneous engine frictional torque: Its components and piston assembly friction  

Microsoft Academic Search

The overall goal of this report is to document the work done to determine the instantaneous frictional torque of an internal combustion engine by using a new approach known as the P-(omega) method developed at Wayne State University. The emphasis has been to improve the accuracy of the method, and apply it to both diesel and gasoline engines under different

Fred A. Nichols; N. A. Henein

1992-01-01

448

Active surge control of centrifugal compressors using drive torque  

E-print Network

recycling, and there is a potential for reduced energy consumption of the compressor. Electric driveActive surge control of centrifugal compressors using drive torque Jan Tommy Gravdahl , Olav control is presented. A centrifugal compressor driven by an electrical motor is studied, and the drive

Gravdahl, Jan Tommy

449

High Horsepower and High Torque Performance of EP Gear Lubricants  

Microsoft Academic Search

In recent months a series of premature gear failures in field operated vehicles produced indications of insufficient load carrying qualities in extreme pressure lubricants of the GL-4 specification conforming to the new Military L-2105A. This condition prompted dynamometer testing in an investigation of horsepower absorption and high torque absorption of these lubricants as compared with extreme pressure lubricants conforming to

R. K. Nelson; L. J. Valentine

1960-01-01

450

A quantitative assessment of torque-transducer models for magnetoreception  

PubMed Central

Although ferrimagnetic material appears suitable as a basis of magnetic field perception in animals, it is not known by which mechanism magnetic particles may transduce the magnetic field into a nerve signal. Provided that magnetic particles have remanence or anisotropic magnetic susceptibility, an external magnetic field will exert a torque and may physically twist them. Several models of such biological magnetic-torque transducers on the basis of magnetite have been proposed in the literature. We analyse from first principles the conditions under which they are viable. Models based on biogenic single-domain magnetite prove both effective and efficient, irrespective of whether the magnetic structure is coupled to mechanosensitive ion channels or to an indirect transduction pathway that exploits the strayfield produced by the magnetic structure at different field orientations. On the other hand, torque-detector models that are based on magnetic multi-domain particles in the vestibular organs turn out to be ineffective. Also, we provide a generic classification scheme of torque transducers in terms of axial or polar output, within which we discuss the results from behavioural experiments conducted under altered field conditions or with pulsed fields. We find that the common assertion that a magnetoreceptor based on single-domain magnetite could not form the basis for an inclination compass does not always hold. PMID:20086054

Winklhofer, Michael; Kirschvink, Joseph L.

2010-01-01

451