These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

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

2

Production Experiences with the Cray-Enabled TORQUE Resource Manager  

SciTech Connect

High performance computing resources utilize batch systems to manage the user workload. Cray systems are uniquely different from typical clusters due to Cray s Application Level Placement Scheduler (ALPS). ALPS manages binary transfer, job launch and monitoring, and error handling. Batch systems require special support to integrate with ALPS using an XML protocol called BASIL. Previous versions of Adaptive Computing s TORQUE and Moab batch suite integrated with ALPS from within Moab, using PERL scripts to interface with BASIL. This would occasionally lead to problems when all the components would become unsynchronized. Version 4.1 of the TORQUE Resource Manager introduced new features that allow it to directly integrate with ALPS using BASIL. This paper describes production experiences at Oak Ridge National Laboratory using the new TORQUE software versions, as well as ongoing and future work to improve TORQUE.

Ezell, Matthew A [ORNL] [ORNL; Maxwell, Don E [ORNL] [ORNL; Beer, David [Adaptive Computing] [Adaptive Computing

2013-01-01

3

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

4

Fatigue affects peak joint torque angle in hamstrings but not in quadriceps.  

PubMed

Primary aim of this study was to investigate peak joint torque angle (i.e. the angle of peak torque) changes recorded during an isokinetic test before and after a fatiguing soccer match simulation. Secondarily we want to investigate functional Hecc:Qconc and conventional Hconc:Qconc ratio changes due to fatigue. Before and after a standardised soccer match simulation, twenty-two healthy male amateur soccer players performed maximal isokinetic strength tests both for hamstrings and for quadriceps muscles at 1.05 rad · s(?1), 3.14 rad · s(?1) and 5.24 rad · s(?1). Peak joint torque angle, peak torque and both functional Hecc:Qconc and conventional Hconc:Qconc ratios were examined. Both dominant and non-dominant limbs were tested. Peak joint torque angle significantly increased only in knee flexors. Both eccentric and concentric contractions resulted in such increment, which occurred in both limbs. No changes were found in quadriceps peak joint torque angle. Participants experienced a significant decrease in torque both in hamstrings and in quadriceps. Functional Hecc:Qconc ratio was lower only in dominant limb at higher velocities, while Hconc:Qconc did not change. This study showed after specific fatiguing task changes in hamstrings only torque/angle relationship. Hamstrings injury risk could depend on altered torque when knee is close to extension, coupled with a greater peak torque decrement compared to quadriceps. These results suggest the use eccentric based training to prevent hamstrings shift towards shorter length. PMID:25517892

Coratella, Giuseppe; Bellin, Giuseppe; Beato, Marco; Schena, Federico

2015-06-01

5

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

6

Amplitude and frequency measures of surface electromyography during dual task elbow torque production  

Microsoft Academic Search

Summary  Studies of motor unit recruitment thresholds have demonstrated the existence of task-specific motor units within the muscles controlling the elbow. Two degree-of-freedom (df) task specificity was investigated at higher levels of elbow torque using the amplitude and frequency characteristics of surface electromyography (EMG). Flexion and supination torque data were collected together with EMG from electrode pairs on the brachioradialis (BRAD),

G. E. Caldwell; J. C. Jamison; S. Lee

1993-01-01

7

Management Practices Affect Production and Profitability  

E-print Network

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

8

The marketing implications of affective product design.  

PubMed

Emotions are compelling human experiences and product designers can take advantage of this by conceptualizing emotion-engendering products that sell well in the market. This study hypothesized that product attributes influence users' emotions and that the relationship is moderated by the adherence of these product attributes to purchase criteria. It was further hypothesized that the emotional experience of the user influences purchase intention. A laboratory study was conducted to validate the hypotheses using mobile phones as test products. Sixty-two participants were asked to assess eight phones from a display of 10 phones and indicate their emotional experiences after assessment. Results suggest that some product attributes can cause intense emotional experience. The attributes relate to the phone's dimensions and the relationship between these dimensions. The study validated the notion of integrating affect in designing products that convey users' personalities. PMID:17303064

Seva, Rosemary R; Duh, Henry Been-Lirn; Helander, Martin G

2007-11-01

9

Torque sensor  

Microsoft Academic Search

Mechanical means for sensing turning torque generated by the load forces in a rotary drive system is described. The sensing means is designed to operate with minimal effect on normal operation of the drive system. The invention can be employed in various drive systems, e.g., automotive engine-transmission power plants, electric motor-operated tools, and metal cutting machines. In such drive systems,

E. Fgeppert

1984-01-01

10

Tennis in hot and cool conditions decreases the rapid muscle torque production capacity of the knee extensors but not of the plantar flexors  

PubMed Central

Objectives To assess the time course of changes in rapid muscle force/torque production capacity and neuromuscular activity of lower limb muscles in response to prolonged (?2?h) match-play tennis under heat stress. Methods The rates of torque development (RTD) and electromyographic activity (EMG; ie, root mean square) rise were recorded from 0 to 30, –50, –100 and –200?ms during brief (3–5?s) explosive maximal isometric voluntary contractions (MVC) of the knee extensors (KE) and plantar flexors (PF), along with the peak RTD within the entirety of the torque-time curve. These values were recorded in 12 male tennis players before (prematch) and after (postmatch, 24 and 48?h) match-play in HOT (?37°C) and COOL (?22°C) conditions. Results The postmatch core temperature was greater in the HOT (?39.4°C) vs COOL (?38.7°C) condition (p<0.05). Reductions in KE RTD occurred within the 0–200?ms epoch after contraction onset postmatch and at 24?h, compared with prematch, independent of environmental conditions (p<0.05). A similar reduction in the KE peak RTD was also observed postmatch relative to prematch (p<0.05). No differences in KE RTD values were observed after normalisation to MVC torque. Furthermore, the rate of KE EMG activity rise remained unchanged. Conversely, the PF contractile RTD and rate of EMG activity rise were unaffected by the exercise or environmental conditions. Conclusions In the KE, a reduction in maximal torque production capacity following prolonged match-play tennis appears to account for the decrease in the rate of torque development, independent of environmental conditions, while remaining unchanged in the PF. PMID:24668381

Girard, Olivier; Racinais, Sébastien; Périard, Julien D

2014-01-01

11

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

12

Evaluating how electronic charting affects resident productivity.  

PubMed

Electronic medical records (EMRs) are becoming standard to improve the communication of information and longevity of patient records. Using an EMR in the emergency department (ED) could potentially slow residents evaluating patients. We evaluated how introducing an EMR affected resident productivity in an academic ED. We retrospectively studied first year emergency medicine residents from a large, academic, tertiary care center before-and-after the institution of an EMR on July 1st, 2010. No residents from the 2009-2010 class used the EMR, while all of the 2010-2011 residents used the EMR. We performed univariate and multivariate analyses using productivity, measured in patients per hour (pt/hr), as the primary outcome. A mixed-model multivariate regression, stratified by acuity zone, was created incorporating EMR and other possible confounders: admissions, signouts, daily ED volume, and days after July 1st for each shift. The study was granted IRB waiver of informed. We reviewed 2,405 shifts: 1,259 shifts before and 1,146 shifts after EMR implementation. When using the EMR, the univariate analysis estimated a 0.084 pt/hr increase in the high acuity zone (p = 0.1317) and 0.029 pt/hr decrease (p = 0.7085) in the low acuity zone. The multivariate regression estimated a 0.038 pt/hr increase (p = 0.3413) in the high acuity zone and a 0.009 pt/hr increase (p = 0.9049) in the low acuity zone with the EMR. Despite the expectation that electronic charting is detrimental to resident productivity, our analyses do not suggest a significant relationship between resident productivity and using the EMR. PMID:23334927

Henning, Daniel; Horng, Steven; Sanchez, Leon

2013-03-01

13

Hex ball torque test  

NASA Technical Reports Server (NTRS)

A series of torque tests were performed on four flight-type hex ball universal joints in order to characterize and determine the actual load-carrying capability of this device. The universal joint is a part of manual actuation rods for scientific instruments within the Hubble Space Telescope. It was found that the hex ball will bind slightly during the initial load application. This binding did not affect the function of the universal joint, and the units would wear-in after a few additional loading cycles. The torsional yield load was approximately 50 ft-lb, and was consistent among the four test specimens. Also, the torque required to cause complete failure exceeded 80 ft-lb. It is concluded that the hex ball universal joint is suitable for its intended applications.

Robinson, B. A.; Foster, C. L.

1986-01-01

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

Parameters affecting solvent production by Clostridium pasteurianum  

SciTech Connect

The effect of pH, growth rate, phosphate and iron limitation, carbon monoxide, and carbon source on product formation by Clostridium pasteurianum was determined. Under phosphate limitation, glucose was fermented almost exclusively to acetate and butyrate independently of the pH and growth rate. Iron limitation caused lactate production (38 mol/100 mol) from glucose in batch and continuous culture. At 15% (vol/vol) carbon monoxide in the atmosphere, glucose was fermented to ethanol (24 mol/100 mol), lactate (32 mol/100 mol), and butanol (36 mol/100 mol) in addition to the usual products, acetate (38 mol/100 mol) and butyrate (17 mol/100 mol). During glycerol fermentation, a completely different product pattern was found. In continuous culture under phosphate limitation, acetate and butyrate were produced only in trace amounts, whereas ethanol (30 mol/10 mol), butanol (18 mol/100 mol), and 1,3-propanediol (18 mol/100 mol) were the major products. Under iron limitation, the ratio of these products could be changed in favor of 1,3-propanediol (34 mol/100 mol). In addition, lactate was produced in significant amounts (25 mol/100 mol). The tolerance of C. pasteurianum to glycerol was remarkably high; growth was not inhibited by glycerol concentrations up to 17% (wt/vol). Increasing glycerol concentrations favored the production of 1,3-propanediol.

Dabrock, B.; Bahl, H.; Gottschalk, G. (Georg-August-Univ. Goettingen (Germany))

1992-04-01

16

Do Intangible Investments Affect Companies' Productivity Performance?  

Microsoft Academic Search

Using company accounts data for 5 countries (US, UK, Japan, France and Germany) we analyse the relationship between intangibles and productivity. We integrate the company data with industry information on tangible and intangible investments and skill composition of the labour force. The industry data are summarised in two different taxonomies, factor and skill intensive groups, obtained using cluster analysis. These

Mary OMahony; Michela Vecchi

2002-01-01

17

PRODUCT MEANING, AFFECTIVE USE EVALUATION, AND TRANSFER: A PRELIMINARY STUDY  

Microsoft Academic Search

The first part of this investigation explored the multidimensional nature of product meaning, referring to the variety of connotations and functions a consumer associates with a particular product category. The subsequent experiment examined the moderation effects of product meaning and other attributes of the user on (a) the affective evaluation of an obstructed use interaction, and (b) the transfer of

Sacha Helfenstein

18

Original article Rose flower production and quality as affected  

E-print Network

Original article Rose flower production and quality as affected by Ca concentration in the petal) Abstract ­ The quality of cut rose flowers at the post-harvest stage is affected by the susceptibility to Botrytis flower blight. This parameter may be related to Ca concentration in the flowers. The objective

Paris-Sud XI, Université de

19

An affective-cognitive framework of product ecosystem design  

Microsoft Academic Search

Companies have been constantly confronting the challenge of designing products for a totality of user experience, both affectively pleasurable with optimal intensity and cognitively convenient with appropriate intuition. It becomes more common that consumer products turn to be correlated with one another, in conjunction with services, use environments, along with many use context-related factors. This leads to a scenario of

F. Zhou; R. J. Jiao; Q. Xu; S. Chen; X. Qu; M. G. Helander

2009-01-01

20

Metabolic differences in temperamental Brahman cattle can affect productivity  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many factors may adversely affect the growth and productivity of livestock. These include stressors associated with management practices, such as weaning, handling relative to transportation, and vaccination, that can modulate growth through the production of stress-related hormones (i.e., cortisol,...

21

Thomas precession and torque  

NASA Astrophysics Data System (ADS)

The spin of a gyroscope that undergoes Thomas precession seems to change its direction without any torque, which would mean that conservation of angular momentum is violated. To resolve this paradox, it is shown that the spin dynamics equation describing Thomas precession (the BMT equation) can be written in terms of a torque applied to the spin. A simple method of finding an explicit expression for the torque is presented in the case of a gyroscope performing circular motion. An unexpected oscillatory character of the torque is explained in terms of the difference between the proper spin and the spin observed in the laboratory frame.

Rebilas, Krzysztof

2015-03-01

22

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

23

RESEARCH ARTICLE Colony pollen reserves affect body size, sperm production  

E-print Network

of large size variation in males of stingless bees that is related with the amount of pollen reservesRESEARCH ARTICLE Colony pollen reserves affect body size, sperm production and sexual development in males of the stingless bee Melipona beecheii F. G. Pech-May · L. Medina-Medina · W. de J. May-Itza´ · R

Paxton, Robert

24

Power torque wrench concept for precision torque application  

NASA Technical Reports Server (NTRS)

Precision electromechanical power wrench applies a given amount of torque to a series of fasteners. It uses a commercially available dc permanent magnet torque motor with a current-controllable torque output and torque value indicator designed to the principles of human engineering.

Peters, G. A.; Warming, K.

1967-01-01

25

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

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

Food and predators affect egg production in song sparrows.  

PubMed

Although the possibility that food and predators may interact in limiting avian populations has long been recognized, there have been few attempts to test this experimentally in the field. We conducted a manipulative food addition experiment on the demography of Song Sparrows (Melospiza melodia) across sites that varied in predator abundance, near Victoria, British Columbia, Canada, over three consecutive breeding seasons. We previously showed that food and predators had interactive effects on annual reproductive success (young fledged per female). Here, we report the effects on egg production. Our results show that food limits the total number of eggs laid over the breeding season ("total egg production") and that interactive food and predator effects, including food effects on nest predation, determine how those eggs are "parceled out" into different nests. Food addition alone significantly affected total egg production, and there was no significant interannual variability in this result. At the same time, both food and predators affected the two determinants of total egg production: "clutch number" (total number of clutches laid) and average clutch size. Both clutch number and size were affected by a food x predator x year interaction. Clutch number was lower at low-predator locations because there was less nest predation and thus less renesting. Food addition also significantly reduced nest predation, but there was significant interannual variation in this effect. This interannual variation was responsible for the food x predator x year interactions because the larger the effect of food on nest predation in a given year, the smaller was the effect of food on clutch number; and the smaller the effect of food on clutch number, the larger was the effect of food on clutch size. Potential predator and year effects on total egg production were thus cancelled out by an inverse relationship between clutch number and clutch size. We suggest that combined food and predator effects on demography could be the norm in both birds and mammals. PMID:17089655

Zanette, Liana; Clinchy, Michael; Smith, James N M

2006-10-01

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

How does burnout affect physician productivity? A systematic literature review  

PubMed Central

Background Interest in the well-being of physicians has increased because of their contributions to the healthcare system quality. There is growing recognition that physicians are exposed to workplace factors that increase the risk of work stress. Long-term exposure to high work stress can result in burnout. Reports from around the world suggest that about one-third to one-half of physicians experience burnout. Understanding the outcomes associated with burnout is critical to understanding its affects on the healthcare system. Productivity outcomes are among those that could have the most immediate effects on the healthcare system. This systematic literature review is one of the first to explore the evidence for the types of physician productivity outcomes associated with physician burnout. It answers the question, “How does burnout affect physician productivity?” Methods A systematic search was performed of: Medline Current, Medline in process, PsycInfo, Embase and Web of Science. The search period covered 2002 to 2012. The searches identified articles about practicing physicians working in civilian settings. Articles that primarily looked only at residents or medical students were excluded. Productivity was captured by hours worked, patients seen, sick leave, leaving the profession, retirement, workload and presenteeism. Studies also were excluded if: (1) the study sample was not comprised of at least 50% physicians, (2) the study did not examine the relationship between burnout and productivity or (3) a validated measure of burnout was not used. Results The search identified 870 unique citations; 5 met the inclusion/exclusion criteria. This review indicates that globally there is recognition of the potential impact of physician burnout on productivity. Productivity was examined using: number of sick leave days, work ability, intent to either continue practicing or change jobs. The majority of the studies indicate there is a negative relationship between burnout and productivity. However, there is variation depending on the type of productivity outcome examined. Conclusions There is evidence that burnout is associated with decreased productivity. However, this line of inquiry is still developing. A number of gaps are yet to be filled including understanding how to quantify the changes in productivity related to burnout. PMID:25066375

2014-01-01

31

Parameters Affecting Ethyl Ester Production by Saccharomyces cerevisiae during Fermentation?  

PubMed Central

Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of unsaturated fatty acids in the fermentation medium resulted in a general decrease in ethyl ester production. On the other hand, a higher fermentation temperature resulted in greater ethyl octanoate and decanoate production, while a higher carbon or nitrogen content of the fermentation medium resulted in only moderate changes in ethyl ester production. Analysis of the expression of the ethyl ester biosynthesis genes EEB1 and EHT1 after addition of medium-chain fatty acid precursors suggested that the expression level is not the limiting factor for ethyl ester production, as opposed to acetate ester production. Together with the previous demonstration that provision of medium-chain fatty acids, which are the substrates for ethyl ester formation, to the fermentation medium causes a strong increase in the formation of the corresponding ethyl esters, this result further supports the hypothesis that precursor availability has an important role in ethyl ester production. We concluded that, at least in our fermentation conditions and with our yeast strain, the fatty acid precursor level rather than the activity of the biosynthetic enzymes is the major limiting factor for ethyl ester production. The expression level and activity of the fatty acid biosynthetic enzymes therefore appear to be prime targets for flavor modification by alteration of process parameters or through strain selection. PMID:17993562

Saerens, S. M. G.; Delvaux, F.; Verstrepen, K. J.; Van Dijck, P.; Thevelein, J. M.; Delvaux, F. R.

2008-01-01

32

Analysis of cogging torque considering tolerance of axial displacement on BLDC motor by using a stochastic simulation coupled with 3-D EMCN  

Microsoft Academic Search

In this paper, a tolerance analysis concerned with an axial displacement on a brushless dc motor is studied. The axial displacement occurring in productions of a brushless dc motor directly affects its torque ripple. Therefore, the tolerance analysis is very important to improve the robustness of its production. This work is accomplished by stochastic simulation in order to overcome disadvantages

Young-Kyoun Kim; Jeong-Jong Lee; Jung-Pyo Hong; Yoon Hur

2004-01-01

33

Detailed methodology for determining torque limits to maximize preload for high-strength threaded fasteners  

NASA Astrophysics Data System (ADS)

High-strength threaded fasteners are an amazing product of engineering, and one of the most common methods of making structural attachments. They are frequently used in structural joints because of two important features: such fasteners allow disassembly and reassembly of the joint, and they can generate high clamping loads called preload. To achieve the full benefit of threaded fasteners, the initial preload must be maximized. The benefits of high preload are well documented and include improved fatigue resistance, increased joint stiffness, and better resistance to vibration loosening. For joints in shear, preload resists relative motion, or slip, of the clamped members. Many factors, like elastic interactions and embedment, tend to lower the initial preload placed on the fastener. These factors provide additional motivation to maximize the initial preload. Also, in aerospace applications, maximized preloads help to achieve the full structural capacity from the fasteners, thereby minimizing weight. Of the available methods for controlling fastener preload, "torque control" is the most common. Unfortunately, determining the torque to maximize preload is problematic and greatly complicated by the large preload scatter generally seen with torque control. This dissertation presents a detailed methodology for generating torque limits to maximize preload for high-strength threaded fasteners. The methodology accounts for the large scatter in preload found with torque control, and therefore, addresses the statistical challenges of dealing with preload uncertainty. In developing this methodology, the probabilities of yielding the bolt during installation were calculated. To calculate these probabilities, the expected scatter in effective stress had to be determined. The scatter (or uncertainty) in the bolt's effective stress was shown to be less than the scatter in bolt preload. This result was observed in the torque-tension test data and also predicted by propagation of uncertainty theory. Prevailing torque is the torque required to overcome a locking feature in a fastener. The locking feature, typically added to the nut, helps to maintain preload and provide resistance to vibration loosening. Using this methodology, the prevailing torque of each locking nut is measured at installation to ensure that it is within specification. However, the measured prevailing torque is not added to the specified torque limit because its effect is already included in the torque limit value. Prevailing torque was shown to slightly reduce the achievable preload. Finally, the methodology was developed for specific fastener combinations; defined as a specific bolt type, nut, washer, and lubricant. Since friction is known to be the main influence on preload and preload scatter, testing specific fastener combinations limits the variables that affect friction. Once a torque limit is determined for a specific fastener combination, it can be applied to any joint using that combination. Taking this approach eliminates the need and the cost of lot-specific or joint-specific testing. A wide range of torque-tension fastener testing was conducted in support of this work. The results from this research should enable design engineers and structural analysts to produce more optimized bolted joints, leading to better structural designs.

Hissam, D. Andy

34

Negative Optical Torque  

PubMed Central

Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of “negative optical torque”, meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained. PMID:25226863

Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C. T.

2014-01-01

35

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.

36

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

37

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

38

Methyl salicylate production in tomato affects biotic interactions.  

PubMed

The role of methyl salicylate (MeSA) production was studied in indirect and direct defence responses of tomato (Solanum lycopersicum) to the spider mite Tetranychus urticae and the root-invading fungus Fusarium oxysporum f. sp. lycopersici, respectively. To this end, we silenced the tomato gene encoding salicylic acid methyl transferase (SAMT). Silencing of SAMT led to a major reduction in SAMT expression and MeSA emission upon herbivory by spider mites, without affecting the induced emission of other volatiles (terpenoids). The predatory mite Phytoseiulus persimilis, which preys on T. urticae, could not discriminate between infested and non-infested SAMT-silenced lines, as it could for wild-type tomato plants. Moreover, when given the choice between infested SAMT-silenced and infested wild-type plants, they preferred the latter. These findings are supportive of a major role for MeSA in this indirect defence response of tomato. SAMT-silenced tomato plants were less susceptible to a virulent strain of F. oxysporum f. sp. lycopersici, indicating that the direct defense responses in the roots are also affected in these plants. Our studies show that the conversion of SA to MeSA can affect both direct and indirect plant defence responses. PMID:20059742

Ament, Kai; Krasikov, Vladimir; Allmann, Silke; Rep, Martijn; Takken, Frank L W; Schuurink, Robert C

2010-04-01

39

Variable torque prescription: state of art.  

PubMed

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

40

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.; Dinoi, Maria Teresa; Monaco, Annalisa; Marzo, Giuseppe; Capogreco, Mario

2015-01-01

41

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

42

Mesoscale physical variability affects zooplankton production in the Labrador Sea  

NASA Astrophysics Data System (ADS)

Surface distribution (0-100 m) of zooplankton biomass and specific aminoacyl-tRNA synthetases (AARS) activity, as a proxy of structural growth, were assessed during winter 2002 and spring 2004 in the Labrador Sea. Two fronts formed by strong boundary currents, several anticyclonic eddies and a cyclonic eddy were studied. The spatial contrasts observed in seawater temperature, salinity and fluorescence, associated with those mesoscale structures, affected the distributions of both zooplankton biomass and specific AARS activity, particularly those of the smaller individuals. Production rates of large organisms (200-1000 ?m) were significantly related to microzooplankton biomass (63-200 ?m), suggesting a cascade effect from hydrography through microzooplankton to large zooplankton. Water masses defined the biomass distribution of the three dominant species: Calanus glacialis was restricted to cold waters on the shelves while Calanus hyperboreus and Calanus finmarchicus were widespread from Canada to Greenland. Zooplankton production was up to ten-fold higher inside anticyclonic eddies than in the surrounding waters. The recent warming tendency observed in the Labrador Sea will likely generate weaker convection and less energetic mesoscale eddies. This may lead to a decrease in zooplankton growth and production in the Labrador basin.

Yebra, L.; Harris, R. P.; Head, E. J. H.; Yashayaev, I.; Harris, L. R.; Hirst, A. G.

2009-05-01

43

Bending and Torque Activities  

NSDL National Science Digital Library

This page presents activities related to Bending and Torque from the Science & Engineering in the Lives of Students project. Activities include Foam Bricks, Nut and Bolt Torsion, Skateboarding, and Tennis Serve Bending & Torsion Activity. Each activity includes a detailed description, list of the materials needed, science concepts covered, and reflection questions.

44

Controlled-Torque Starting of Textile Machinery  

Microsoft Academic Search

Control of the starting torque of textile machinery drives has become an important factor in the effective performance of textile machinery. Increased operating speeds to achieve greater production requires more precise acceleration of machine components to ensure efficient operation. Controlled acceleration also eliminates premature failure of the machine elements. Many factors must be considered in determining the optimum system for

W. Harvey Darke; Harold L. Prescott

1971-01-01

45

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

46

Influence of gastrocnemius muscle length on triceps surae torque development and electromyographic activity in man  

Microsoft Academic Search

The present study was designed to determine the relative contribution of the gastrocnemius muscle to isometric plantar flexor torque production at varying knee angles, while investigating the activation of the gastrocnemius muscle at standardised non-optimal lengths. Voluntary plantar flexor torque, supramaximally stimulated twitch torque and myoelectric activity (EMG) from the triceps surae were measured at different knee angles. Surface and

A. G. Cresswell; W. N. Löscher; A. Thorstensson

1995-01-01

47

Issues in reducing the cogging torque of mass-produced permanent-magnet brushless DC motor  

Microsoft Academic Search

A variety of techniques are available to reduce cogging torque in permanent-magnet brushless DC motors. Theoretically, all the techniques are quite effective for minimizing the cogging torque. This paper presents the efficacy of these methods in mass production subject to manufacturing tolerances\\/variations. The cogging torque minimization becomes a challenging task when the requirement is very stringent in applications such as

Mohammad S. Islam; Sayeed Mir; Tomy Sebastian

2004-01-01

48

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

49

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

50

Torque on an ideal plasma.  

PubMed

Ripples in the confining field may exert a torque on a rotating plasma. Time reversal symmetry implies that this torque should vanish for an ideal plasma. However, even in an apparently ideal plasma, singularities can give rise to a nonzero torque. This torque is evaluated for a simple configuration. Although the primary force is magnetic, an essential contribution arises from other nonlinear terms in the equations of motion. The net force is confined to the singular layer, in the direction of the ripple wave vector and related to the energy absorbed in the layer. PMID:14525433

Taylor, J B

2003-09-12

51

Electron spin torque in atoms  

NASA Astrophysics Data System (ADS)

The spin torque and zeta force, which govern spin dynamics, are studied by using monoatoms in their steady states. We find nonzero local spin torque in transition metal atoms, which is in balance with the counter torque, the zeta force. We show that d-orbital electrons have a crucial effect on these torques. Nonzero local chirality density in transition metal atoms is also found, though the electron mass has the effect to wash out nonzero chirality density. Distribution patterns of the chirality density are the same for Sc-Ni atoms, though the electron density distributions are different.

Hara, Takaaki; Senami, Masato; Tachibana, Akitomo

2012-03-01

52

Thermostable extracellular protease of Bacillus stearothermophilus : factors affecting its production  

Microsoft Academic Search

A strain of protease-producing Bacillus stearothermophilus has been isolated. Glycerol was the best carbon source for production whereas yeast extract was the best nitrogen source. The bacterium could grow up to 70°C but optimum protease production was at 60°C. Best initial pH for protease production was 5. Alkaline pH inhibited production. The enzyme was stable at 60°C for 18 h

N. A. Razak; M. Y. A. Samad; M. Basri; W. M. Z. W. Yunus; K. Ampon; A. B. Salleh

1994-01-01

53

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

54

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

55

Statistical Frequency in Perception Affects Children's Lexical Production  

ERIC Educational Resources Information Center

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…

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

2009-01-01

56

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

57

Planting Date Affects Production and Quality of Grass Pea Forage.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The rising cost of commercial nitrogen (N) fertilizer has generated interest in including legumes in cropping systems. Research on agronomic practices required to integrate legumes into cereal-based systems of the Southern Great Plains (SGP) is required. This study examined how planting date affect...

58

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

59

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...

60

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

61

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

62

Birefringent torque sensor for motors  

NASA Astrophysics Data System (ADS)

Birefringent optical materials can be used to convert mechanical strain into fringe patterns of optical intensity which have typically been used to measure surface stains or stresses. In this paper a system will be described that uses a photoelastic transducer, linear sensor array, and neural network image processing to estimate the load torque for stationary and rotating motor shafts up to 1500 rpm. A photoelastic polymer coupling is attached to the shaft, and illuminated by polarized light. As the shaft torque varies the photoelastic plastic coupling experiences torsional strain. This results in a corresponding 2D fringe pattern when viewed through an optical polarizer. The strain that causes this observed pattern in a complex function of the applied torque applied to the shaft. A neural network is trained with the fringe patterns corresponding to calibrated load torques as measured by a laboratory strain gauge torque sensor. Experimental results show that the neural network torque estimator can accurately estimate the applied torque for both static and rotating shafts.

Chung, Dukki; Merat, Francis L.; Discenzo, Fred M.; Harris, James S.

1998-12-01

63

Factors Affecting the Production of Vietnamese Tones: A Study of American Learners  

ERIC Educational Resources Information Center

This study investigates factors that affect the accuracy of tone production by American students of Vietnamese as a second language (L2). Nine hypotheses are examined, each of which isolates a factor expected to affect production accuracy: (a) task type, (b) the position of a tone in a clause, (c) discourse distance between a model provided by a…

Nguyen, Hanh thi; Macken, Marlys A.

2008-01-01

64

Thermomagnetic Torque in Nh3  

E-print Network

of (H/P) significantly less than (H/P), q, except for oxygen, which has two peaks one T, Vf . AD AI R, III AND G. R. M c C I U RG TABLE I . Senftleben-Beenakker parameter (H/I') f /2 for thermal conductivity and viscosity compared to Scott- torque... 5 000 14 800 DISCUSSION Measurements here indicate that NH3 has a Scott torque in the positive direction. A torque in the of which gives (H/P) ~ larger than (H/P)?2. The gas HD likewise has two Scott peaks and exhibits an anomalously small...

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

1970-01-01

65

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

66

Polysaccharide production by Aureobasidium pullulans: factors affecting polysaccharide formation  

Microsoft Academic Search

Aureobasidium pullulans NRRL 6220 synthesized polysaccharide most actively in media containing sucrose, fructose or maltose with (NH4)2SO4 (0.6 g\\/l) or ammonium acetate giving greatest yields of the polysaccharide. With (NH4)2SO4 at =1.2 g\\/l, production of polysaccharide was decreased considerably. Polysaccharide production was highest with an initial pH of 6.5 while biomass formation was better below an initial pH of 5.5.

S. M. Badr-Eldin; O. M. El-Tayeb; H. G. El-Masry; F. H. A. Mohamad; O. A. Abd El-Rahman

1994-01-01

67

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

68

Does breed of ram affect ewe and lamb productivity?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Systematic use of breed diversity in terminal crossbreeding systems can improve the efficiency of commercial lamb production. Data from controlled research should be used to select the genetic line or lines of rams to use in terminal crossbreeding systems. Thus, research is underway at the USDA, ARS...

69

Will Water Scarcity Affect Agricultural Production in China?  

Microsoft Academic Search

China has achieved impressive increases in grain production over the last 50 years due in large part to the expansion of irrigation, but many observers are beginning to question whether irrigated agriculture is sustainable in areas of China where water is relatively scarce. Despite competition from rapidly growing industry and increasingly wealthy consumers, farmers still receive over two-thirds of China's

Bryan Lohmar; Jinxia Wang

70

The FRIABLE1 Gene Product Affects Cell Adhesion in Arabidopsis  

PubMed Central

Cell adhesion in plants is mediated predominantly by pectins, a group of complex cell wall associated polysaccharides. An Arabidopsis mutant, friable1 (frb1), was identified through a screen of T-DNA insertion lines that exhibited defective cell adhesion. Interestingly, the frb1 plants displayed both cell and organ dissociations and also ectopic defects in organ separation. The FRB1 gene encodes a Golgi-localized, plant specific protein with only weak sequence similarities to known proteins (DUF246). Unlike other cell adhesion deficient mutants, frb1 mutants do not have reduced levels of adhesion related cell wall polymers, such as pectins. Instead, FRB1 affects the abundance of galactose- and arabinose-containing oligosaccharides in the Golgi. Furthermore, frb1 mutants displayed alteration in pectin methylesterification, cell wall associated extensins and xyloglucan microstructure. We propose that abnormal FRB1 action has pleiotropic consequences on wall architecture, affecting both the extensin and pectin matrices, with consequent changes to the biomechanical properties of the wall and middle lamella, thereby influencing cell-cell adhesion. PMID:22916179

Neumetzler, Lutz; Humphrey, Tania; Lumba, Shelley; Snyder, Stephen; Yeats, Trevor H.; Usadel, Björn; Vasilevski, Aleksandar; Patel, Jignasha; Rose, Jocelyn K. C.; Persson, Staffan; Bonetta, Dario

2012-01-01

71

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

72

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

73

Magnetically controlled torque wrench prevents overtorquing  

NASA Technical Reports Server (NTRS)

Magnetically controlled torque wrench produces the required torque values accurately, and prevents overtorquing. The force between a magnet and a soft iron bar on the arms of the wrench constitutes a predetermined maximum torque that cannot be exceeded. So long as the magnetic flux remain constant, the torque remains the same.

Rohrer, J. A.

1968-01-01

74

Damping assembly for a torque converter clutch  

Microsoft Academic Search

This patent describes a turbine damped torque converter and clutch. It comprises: a pressure plate; a torque converter turbine; a torque converter impeller; means including a control chamber for the pressure plate means for controlling the apply and release of the clutch for engaging the clutch with the impeller; a torque converter output shaft; a planetary gear arrangement including an

Dull

1989-01-01

75

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

76

Environmental and genetic factors affecting udder characters and milk production in Chios sheep  

E-print Network

Environmental and genetic factors affecting udder characters and milk production in Chios sheep A environmental and genetic factors influencing udder characteristics and milk production in Chios sheep. All. Seasonal effects were significant for udder circumference, test-day milk and total milk production

Paris-Sud XI, Université de

77

Tree species richness affects litter production and decomposition rates in a tropical biodiversity experiment  

E-print Network

Tree species richness affects litter production and decomposition rates in a tropical biodiversity. We report data on leaf litter production and decomposition from a manipulative biodiversity native tree species, with 1-, 3-, and 6-species mixtures. We estimated litter production during the dry

Bermingham, Eldredge

78

How hollow melanosomes affect iridescent colour production in birds  

PubMed Central

Developmental constraints and trade-offs can limit diversity, but organisms have repeatedly evolved morphological innovations that overcome these limits by expanding the range and functionality of traits. Iridescent colours in birds are commonly produced by melanin-containing organelles (melanosomes) organized into nanostructured arrays within feather barbules. Variation in array type (e.g. multilayers and photonic crystals, PCs) is known to have remarkable effects on plumage colour, but the optical consequences of variation in melanosome shape remain poorly understood. Here, we used a combination of spectrophotometric, experimental and theoretical methods to test how melanosome hollowness—a morphological innovation largely restricted to birds—affects feather colour. Optical analyses of hexagonal close-packed arrays of hollow melanosomes in two species, wild turkeys (Meleagris gallopavo) and violet-backed starlings (Cinnyricinclus leucogaster), indicated that they function as two-dimensional PCs. Incorporation of a larger dataset and optical modelling showed that, compared with solid melanosomes, hollow melanosomes allow birds to produce distinct colours with the same energetically favourable, close-packed configurations. These data suggest that a morphological novelty has, at least in part, allowed birds to achieve their vast morphological and colour diversity. PMID:23902909

Eliason, Chad M.; Bitton, Pierre-Paul; Shawkey, Matthew D.

2013-01-01

79

How hollow melanosomes affect iridescent colour production in birds.  

PubMed

Developmental constraints and trade-offs can limit diversity, but organisms have repeatedly evolved morphological innovations that overcome these limits by expanding the range and functionality of traits. Iridescent colours in birds are commonly produced by melanin-containing organelles (melanosomes) organized into nanostructured arrays within feather barbules. Variation in array type (e.g. multilayers and photonic crystals, PCs) is known to have remarkable effects on plumage colour, but the optical consequences of variation in melanosome shape remain poorly understood. Here, we used a combination of spectrophotometric, experimental and theoretical methods to test how melanosome hollowness--a morphological innovation largely restricted to birds--affects feather colour. Optical analyses of hexagonal close-packed arrays of hollow melanosomes in two species, wild turkeys (Meleagris gallopavo) and violet-backed starlings (Cinnyricinclus leucogaster), indicated that they function as two-dimensional PCs. Incorporation of a larger dataset and optical modelling showed that, compared with solid melanosomes, hollow melanosomes allow birds to produce distinct colours with the same energetically favourable, close-packed configurations. These data suggest that a morphological novelty has, at least in part, allowed birds to achieve their vast morphological and colour diversity. PMID:23902909

Eliason, Chad M; Bitton, Pierre-Paul; Shawkey, Matthew D

2013-09-22

80

Procyanidins modify insulinemia by affecting insulin production and degradation.  

PubMed

Previous studies from our research group have suggested that procyanidins modify glycemia and insulinemia. The aim of this work was to evaluate the effects of procyanidins on ?-cell functionality in a nonpathological system. Four groups of healthy rats were studied. The animals were given daily acute doses of grape seed procyanidin extract (GSPE) for different time periods and at different daily amounts. A ?-cell line (INS-1E) was treated with 25 mg GSPE/L for 24 h to identify possible mechanisms of action for the procyanidins. In vivo experiments showed that different doses of GSPE affected insulinemia in different ways by modifying ?-cell functionality and/or insulin degradation. The islets isolated from rats that were treated with 25 mg GSPE/kg of body weight for 45 days exhibited a limited response to glucose stimulation. In addition, insulin gene expression, insulin synthesis and expression of genes related to insulin secretion were all down-regulated. In vitro studies revealed that GSPE decreased the ability of ?-cells to secrete insulin in response to glucose. GSPE increased glucose uptake in ?-cells under high-glucose conditions but impaired glucose-induced mitochondrial hyperpolarization, decreased adenosine triphosphate (ATP) synthesis and altered cellular membrane potentials. GSPE also modified Glut2, glucokinase and Ucp2 gene expression as well as altered the expression of hepatic insulin-degrading enzyme (Ide), thereby altering insulin degradation. At some doses, procyanidins changed ?-cell functionality by modifying insulin synthesis, secretion and degradation under nonpathological conditions. Membrane potentials and Ide provide putative targets for procyanidins to induce these effects. PMID:22444499

Castell-Auví, Anna; Cedó, Lídia; Pallarès, Victor; Blay, M Teresa; Pinent, Montserrat; Motilva, M José; Garcia-Vallvé, Santiago; Pujadas, Gerard; Maechler, Pierre; Ardévol, Anna

2012-12-01

81

Calculation and study on cogging torque of small wind turbine PMSG  

Microsoft Academic Search

Cogging torque is inherent characteristic of PMSG, it affects significantly the cut-in speed of the turbine of wind energy PMSG generation systems. FEM has proved to be the most powerful tool to calculate cogging torque and other important performance of PMSG. In this paper, an improved Maxwell stress tensor method, which can take into account the detailed variation of flux

Zhenhong Guo; Liuchen Chang

2008-01-01

82

Research on the stabilization of friction torque of precision ball screw  

Microsoft Academic Search

Taking into account the influence of the error in the contact points of balls and the groove on the contact force, the influence of manufacturing errors of grooves on friction torque was analyzed. The view that the manufacturing errors of groove in ball screw mechanism affect the value of the friction torque averagely was brought forward. The characteristic of fiction

Zhang Zuoying; Zhang Wanli; Song Xianchun

2009-01-01

83

Clinorotation affects morphology and ethylene production in soybean seedlings  

NASA Technical Reports Server (NTRS)

The microgravity environment of spaceflight influences growth, morphology and metabolism in etiolated germinating soybean. To determine if clinorotation will similarly impact these processes, we conducted ground-based studies in conjunction with two space experiment opportunities. Soybean (Glycine max [L.] Merr.) seeds were planted within BRIC (Biological Research In Canister) canisters and grown for seven days at 20 degrees C under clinorotation (1 rpm) conditions or in a stationary upright mode. Gas samples were taken daily and plants were harvested after seven days for measurement of growth and morphology. Compared to the stationary upright controls, plants exposed to clinorotation exhibited increased root length (125% greater) and fresh weight (42% greater), whereas shoot length and fresh weight decreased by 33% and 16% respectively. Plants grown under clinorotation produced twice as much ethylene as the stationary controls. Seedlings treated with triiodo benzoic acid (TIBA), an auxin transport inhibitor, under clinorotation produced 50% less ethylene than the untreated control subjected to the same gravity treatment, whereas a treatment with 2,4-D increased ethylene by five-fold in the clinorotated plants. These data suggest that slow clinorotation influences biomass partitioning and ethylene production in etiolated soybean plants.

Hilaire, E.; Peterson, B. V.; Guikema, J. A.; Brown, C. S.; Sager, J. C. (Principal Investigator)

1996-01-01

84

A fundamental mechanism of legged locomotion with hip torque and leg damping.  

PubMed

New models and theories of legged locomotion are needed to better explain and predict the robustly stable legged locomotion of animals and some bio-inspired robots. In this paper we observe that a hip-torque and leg-damping mechanism is fundamental to many legged robots and some animals and determine its affect on locomotion dynamics. We discuss why this hip-torque-and-leg-damping mechanism is not so easily understood. We investigate how hip-torque and leg-damping affect the stability and robustness of locomotion using a mathematical model: First, we extend the canonical spring-loaded-inverted-pendulum model to include constant hip torque and leg damping proportional to leg length speed. Then, we calculate the stability and robustness of locomotion as a function of increasing levels of torque and damping, starting from zero-the energy conserving and marginally stable special case-to high levels of torque and damping. We find that the stabilizing effects of hip-torque and leg-damping occur in the context of the piecewise-continuous dynamics of legged locomotion, and so linear intuition does not apply. We discover that adding hip torque and leg damping changes the stability of legged locomotion in an unexpected way. When a small amount of torque and damping are added, legged locomotion is initially destabilized. As more torque and damping are added, legged locomotion turns stable and becomes increasingly more stable and more robust the more torque and damping are added. Also, stable locomotion becomes more probable over the biologically-relevant region of the parameter space, indicating greater prediction and explanatory capabilities of the model. These results provide a more clear understanding of the hip-torque-and-leg-damping mechanism of legged locomotion, and extend existing theory of legged locomotion towards a greater understanding of robustly stable locomotion. PMID:22989956

Shen, Z H; Seipel, J E

2012-12-01

85

CO2, nitrogen, and diversity differentially affect seed production of prairie plants.  

PubMed

Plant species composition and diversity is often influenced by early life history stages; thus, global change could dramatically affect plant community structure by altering seed production. Unfortunately, plant reproductive responses to global change are rarely studied in field settings, making it difficult to assess this possibility. To address this issue, we quantified the effects of elevated CO2, nitrogen deposition, and declining diversity on inflorescence production and inflorescence mass of 11 perennial grassland species in central Minnesota, U.S.A. We analyzed these data to ask whether (1) global change differentially affects seed production of co-occurring species; (2) seed production responses to global change are similar for species within the same functional group (defined by ecophysiology and growth form); and (3) seed production responses to global change match productivity responses: We found that, on average, allocation to seed production decreased under elevated CO2, although individual species responses were rarely significant due to low power (CO2 treatment df = 2). The effects of nitrogen deposition on seed production were similar within functional groups: C4 grasses tended to increase while C3 grasses tended to decrease allocation to seed production. Responses to nitrogen deposition were negatively correlated to productivity responses, suggesting a trade-off. Allocation to seed production of some species responded to a diversity gradient, but responses were uncorrelated to productivity responses and not similar within functional groups. Presumably, species richness has complex effects on the biotic and abiotic variables that influence seed production. In total, our results suggest that seed production of co-occurring species will be altered by global change, which may affect plant communities in unpredictable ways. Although functional groups could be used to generalize seed production responses to nitrogen deposition in Minnesota prairies, we caution against relying on them for predictive purposes without a mechanistic understanding of how resource availability and biotic interactions affect seed production. PMID:19694130

HilleRisLambers, J; Harpole, W S; Schnitzer, S; Tilman, D; Reich, P B

2009-07-01

86

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

Code of Federal Regulations, 2014 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984 What emission limits must I...

2014-07-01

87

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

Code of Federal Regulations, 2013 CFR

... National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 1 Table...exceed 0.024 grams per megagram (0.00005 pounds per ton) of rubber used at the tire production affected...

2013-07-01

88

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

Code of Federal Regulations, 2014 CFR

... National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 1 Table...exceed 0.024 grams per megagram (0.00005 pounds per ton) of rubber used at the tire production affected...

2014-07-01

89

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

Code of Federal Regulations, 2012 CFR

... National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 1 Table...exceed 0.024 grams per megagram (0.00005 pounds per ton) of rubber used at the tire production affected...

2012-07-01

90

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

Code of Federal Regulations, 2010 CFR

... National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 1 Table...exceed 0.024 grams per megagram (0.00005 pounds per ton) of rubber used at the tire production affected...

2010-07-01

91

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

Code of Federal Regulations, 2011 CFR

... National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 1 Table...exceed 0.024 grams per megagram (0.00005 pounds per ton) of rubber used at the tire production affected...

2011-07-01

92

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

93

Factors Affecting Carbohydrate Production and the Formation of Transparent Exopolymer Particles (TEP) by Diatoms  

E-print Network

, the efficiency of the biological carbon pump. The objective of this research was to determine how different factors affect carbohydrate production and the formation of TEP by diatoms, and their role in aggregation. Diatoms were grown in laboratory cultures...

Chen, Jie

2014-03-25

94

Detection of Quantitative Trait Loci Affecting Milk Production, Health, and Reproductive Traits in Holstein Cattle  

Microsoft Academic Search

We report putative quantitative trait loci affecting female fertility and milk production traits using the merged data from two research groups that conducted independent genome scans in Dairy Bull DNA Reposi- tory grandsire families to identify quantitative trait loci (QTL) affecting economically important traits. Six families used by both groups had been genotyped for 367 microsatellite markers covering 2713.5 cM

M. S. Ashwell; D. W. Heyen; T. S. Sonstegard; C. P. Van Tassell; Y. Da; P. M. VanRaden; M. Ron; J. I. Weller; H. A. Lewin

2004-01-01

95

DETECTION OF QUANTITATIVE TRAIT LOCI AFFECTING MILK PRODUCTION, HEALTH, AND REPRODUCTIVE TRAITS IN HOLSTEIN CATTLE  

Technology Transfer Automated Retrieval System (TEKTRAN)

We report putative quantitative trait loci affecting female fertility and milk production traits using the merged data from groups that conducted independent genome scans in Dairy Bull DNA Repository grandsire families to identify quantitative trait loci affecting economically important traits. Six ...

96

Firing of antagonist small-diameter muscle afferents reduces voluntary activation and torque of elbow flexors  

PubMed Central

During muscle fatigue, firing of small-diameter muscle afferents can decrease voluntary activation of the fatigued muscle. However, these afferents may have a more widespread effect on other muscles in the exercising limb. We examined if the firing of fatigue-sensitive afferents from elbow extensor muscles in the same arm reduces torque production and voluntary activation of elbow flexors. In nine subjects we examined voluntary activation of elbow flexors by measuring changes in superimposed twitches evoked by transcranial magnetic stimulation of the motor cortex during brief (2–3 s) maximal voluntary contractions (MVC). Inflation of a blood pressure cuff following a 2-min sustained MVC blocked blood flow to the fatigued muscle and maintained firing of small-diameter afferents. After a fatiguing elbow flexion contraction, maximal flexion torque was lower (26.0 ± 4.4%versus 67.9 ± 5.2% of initial maximal torque; means ±s.d.; P < 0.001) and superimposed twitches were larger (4.1 ± 1.1%versus 1.8 ± 0.2% ongoing MVC, P= 0.01) with than without ischaemia. After a fatiguing elbow extensor contraction, maximal flexion torque was also reduced (82.2 ± 4.9%versus 91.4 ± 2.3% of initial maximal torque; P= 0.007), superimposed twitches were larger (2.7 ± 0.7%versus 1.3 ± 0.2% ongoing MVC; P= 0.02) and voluntary activation lower (81.6 ± 8.2%versus 95.5 ± 6.9%; P= 0.04) with than without ischaemia. After a fatiguing contraction, voluntary drive to the fatigued muscles is reduced with continued input from small-diameter muscle afferents. Furthermore, fatigue of the elbow extensor muscles decreases voluntary drive to unfatigued elbow flexors of the same arm. Therefore, firing of small-diameter muscle afferents from one muscle can affect voluntary activation and hence torque generation of another muscle in the same limb. PMID:23652589

Kennedy, David S; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

2013-01-01

97

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

98

Somatotype Variables Related to Muscle Torque and Power in Judoists  

PubMed Central

The purpose of this study was to examine the relationship between somatotype, muscle torque and power output in judoists. Thirteen judoists (age 18.4±3.1 years, body height 178.6±8.2 cm, body mass 82.3±15.9 kg) volunteered to participate in this study. Somatotype was determined using the Heath-Carter method. Maximal muscle torques of elbow, shoulder, knee, hip and trunk flexors as well as extensors were measured under static conditions. Power outputs were measured in 5 maximal cycle ergometer exercise bouts, 10 s each, at increasing external loads equal to 2.5, 5.0, 7.5, 10.0 and 12.5% of body weight. The Pearson’s correlation coefficients were calculated between all parameters. The mean somatotype of judoists was: 3.5-5.9-1.8 (values for endomorphy, mesomorphy and ectomorphy, respectively). The values (mean±SD) of sum of muscle torque of ten muscle groups (TOTAL) was 3702.2±862.9 N x m. The power output ranged from 393.2±79.4 to 1077.2±275.4 W. The values of sum of muscle torque of right and left upper extremities (SUE), sum of muscle torque of right and left lower extremities (SLE), sum of muscle torque of the trunk (ST) and TOTAL were significantly correlated with the mesomorphic component (0.68, 0.80, 0.71 and 0.78, respectively). The ectomorphic component correlated significantly with values of SUE, SLE, ST and TOTAL (?0.69, ?0.81, ?0.71 and ?0.79, respectively). Power output was also strongly correlated with both mesomorphy (positively) and ectomorphy (negatively). The results indicated that the values of mesomorphic and ectomorphic somatotype components influence muscle torque and power output, thus body build could be an important factor affecting results in judo. PMID:23487284

Lewandowska, Joanna; Bu?ko, Krzysztof; Pastuszak, Anna; Boguszewska, Katarzyna

2011-01-01

99

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...

100

Direct mechanical torque sensor for model wind turbines  

NASA Astrophysics Data System (ADS)

A torque sensor is developed to measure the mechanical power extracted by model wind turbines. The torque is measured by mounting the model generator (a small dc motor) through ball bearings to the hub and by preventing its rotation by the deflection of a strain-gauge-instrumented plate. By multiplying the measured torque and rotor angular velocity, a direct measurement of the fluid mechanical power extracted from the flow is obtained. Such a measurement is more advantageous compared to measuring the electrical power generated by the model generator (dc motor), since the electrical power is largely affected by internal frictional, electric and magnetic losses. Calibration experiments are performed, and during testing, the torque sensor is mounted on a model wind turbine in a 3 rows × 3 columns array of wind turbines in a wind tunnel experiment. The resulting electrical and mechanical powers are quantified and compared over a range of applied loads, for three different incoming wind velocities. Also, the power coefficients are obtained as a function of the tip speed ratio. Significant differences between the electrical and mechanical powers are observed, which highlights the importance of using the direct mechanical power measurement for fluid dynamically meaningful results. A direct calibration with the measured current is also explored. The new torque sensor is expected to contribute to more accurate model wind tunnel tests which should provide added flexibility in model studies of the power that can be harvested from wind turbines and wind-turbine farms.

Kang, Hyung Suk; Meneveau, Charles

2010-10-01

101

Fig. 1: Structure of drive consisting of motor, gear and load Abstract--In this paper the product of torque and acceleration  

E-print Network

MOTOR LOAD MMG, M MGL, LMM ML GEAR Fig. 1: Structure of drive consisting of motor, gear and load because both products are transmitted unchanged by an ideal gear. By use of M-product design procedure because mechanical power is transmitted unchanged by an ideal gear. Consequently each motor is suitable

Paderborn, Universität

102

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

103

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

104

Factors affecting the production of terpenes in seedlings of Pinus elliottii  

E-print Network

FACTORS AFFECTING THE PRODUCTION OF TERPENES IN SEEDLINGS OF PINUS FLLIOITII A Thesis HIROICHI ISHIHARA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... ( ember) J. Charles Lee (Department Head) May 1987 ABSTRACT Factors Affecting the Prcduction of Terpenes in Seedlings of Pinus elliottii. (May 1987) Hiroichi Ishihara, B. S. , Kyoto University, Japan Chairman of Advisory Committee: Dr. Ed J. Soltes...

Ishihara, Hiroichi

1987-01-01

105

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

E-print Network

the desired results. The operator can exercise only partial control over the system. The lack of fine control over the conditions developed inside of the extruder barrel appears to have been the major cause for product variation within a single production.... The main components of high pressure cooking extruders are: feeder, compression screw, barrel, die and heating system. High pressure cooking and forming is characterized by sufficient work and heat being applied to the product to completely cook...

Taranto, Michael Vincent

1974-01-01

106

Health-seeking Behavior, Product Characteristics, and Social Factors Affect Dairy Product Consumption By Elders  

Microsoft Academic Search

A national telephone survey of 495 adults aged in their 60s (n=155), 70s (n=187) and 80+ (n = 151) was conducted to assess behaviors and attitudes concerning dairy product intake. Participants were asked how frequently they consumed milk, yogurt, frozen yogurt, ice cream, cottage cheese, and cheese. Total dairy product intake was the sum of the frequencies of all dairy

J. G. Fischer; V. Burden; S. Elbon; M. A. Johnson

1995-01-01

107

Calculating Horsepower, RPM, and Torque  

NSDL National Science Digital Library

This interactive presentation, created by James Bourassa and John Rosz for the Electromechanical Digital Library, discusses the calculation of horsepower, RPMs, and torque. Bourassa and Rosz begin by providing detailed definitions of all three topics and then provide mathematical examples for computing each measure. Once this basic explanation is complete, the authors allow students to practice these theories in a set of self-correcting quiz questions. Bourassa and Rosz explain each using helpful interactive flash animations. These are not only useful in explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction to calculating horsepower, RPMs, and torque. This could be a valuable learning resource in everything from a physics to a technical education classroom.

Bourassa, James

108

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 ...

109

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

110

Factors that Affect Student Motivation in a Dairy Products Elective Course  

ERIC Educational Resources Information Center

Student motivation is influenced by instructional approach. Motivation is a function of initiating and sustaining goal-directed behavior. The objective of this study was to identify factors (positive and negative) that affect motivation in a junior-level dairy products elective course. Student attitudes were surveyed each year half-way through the…

Ismail, Baraem; Hayes, Kirby

2005-01-01

111

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

E-print Network

populations. We examined the factorial effects of insect herbivore exclusion (via insecticide) and fungal 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

Crews, Stephen

112

Indian ricegrass (Oryzopsis hymenoides) Germination affected by irrigation and bagging during seed production  

Microsoft Academic Search

Seed dormancy is the primary factor limiting stand establishment of Indian ricegrass [Oryzopsis hymenoides (Roem. & Schult.) Ricker] in rangeland reseedings in western North America. Our objective was to determine if irrigation or bagging of plants during seed production affected dormancy of two Indian ricegrass accessions, the cultivar Paloma and the experimental population PI 478833. Bagging of inflorescences for research

T. A. Jones; D. C. Nielson

1994-01-01

113

Urban noise affects song structure and daily patterns of song production in Red-winged Blackbirds  

E-print Network

Urban noise affects song structure and daily patterns of song production in Red-winged Blackbirds on Red-winged Blackbird (Agelaius phoeniceus) song structure and song timing. We recorded bird songs results indicate that at sites with high traffic noise, Red-winged Blackbirds sing songs with fewer

Wilson, David R.

114

Reproductive schedule and factors affecting soldier production in the eusocial bamboo aphid Pseudoregma bambucicola (Homoptera, Aphididae)  

Microsoft Academic Search

Summary: The reproductive characteristics of the soldier-producing aphid Pseudoregma bambucicola were studied in Kagoshima, Southern Japan, to know the factors affecting soldier production of eusocial aphids. The soldier proportion in aphid colonies was highest from October to November. In some large colonies, soldiers were observed in all seasons except in July when colony size was relatively small. Multiple regression analysis

H. Shibao

1999-01-01

115

EARTHWORM ADDITIONS AFFECT LEACHATE PRODUCTION AND NITROGEN LOSSES IN TYPICAL MIDWESTERN AGROECOSYSTEMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Earthworms affect soil structure and the movement of agrochemicals. Yet, there are few field-scale studies that quantify the effect of earthworms on dissolved nitrogen fluxes in agroecosystems. We investigated the influence of biannual deep-burrowing earthworm additions on leachate production and qu...

116

Torque magnetometry in unconventional superconductors  

NASA Astrophysics Data System (ADS)

This thesis describes torque magnetometry studies on unconventional superconductors. Torque magnetometry measures the anisotropic magnetization of samples by recording their torque signals in a tilted magnetic field. Applied to superconductors, this method provides a reliable way to measure the field dependence of magnetization with high resolution under extreme conditions: DC magnetic fields from zero to 45.2 T, and temperature from 300 mK to 300K. The results can be used to determine many important parameters, such as the upper critical field H c2, the superconducting condensation energy, the onset temperature of diamagnetic signals, and so on. We carried out the torque magnetometry measurements on unconventional superconductors---high Tc superconductors and the p-wave superconductor Sr2RuO4---and uncovered new features that do not exist in conventional BCS superconductors. In high Tc superconductors, our torque magnetometry studies focus on the properties of the vortex liquid state. First, by comparing the observed magnetization curves with the Nernst effect results in Bi 2Sr2CaCu2O8+delta, we confirm that the unusually large Nernst effect signals originate from the surviving vortex liquid state above Tc. Second, the M-H curves near the critical temperature Tc suggest that the nature of the transition is the Kosterlitz-Thouless transition. Near Tc, the magnetization response at low field is strongly nonlinear, and the T dependence of the magnetic susceptibility in the low-field limit approaches the predicted curve from the Kosterlitz-Thouless transition. Third, the measurements in intense magnetic field up to 45 T reveal the unusual, weak T-dependence of Hc2. These observations strongly support the existence of the vortex liquid state above Tc. The superconducting state is destroyed by the phase fluctuation of the pair condensate, while the pair condensate keeps its amplitude above T c. Further studies in single-layered high Tc superconductors reveal more interesting features. The diamagnetic magnetization is observed in the lightly-doped non-superconducting La2-xSr xCuO4, and the inferred Hc 2 values are finite and constant at different T. The observations indicate that the vortex liquid state exists in the lightly doped region. The determination of Hc2 and Tonset at different doping levels x display the dome-like x-dependence of these two quantities. Hc2 is found to be linear with T onset with the g-factor being about 2.1. In the p-wave superconductor Sr2RuO 4, the magnetic hysteresis in the mixed state below Tc displays unusual features: the M-H curves are strongly skewed with a break-in-slope at zero field and reversible M-H curves at low field. These features are different from the hysteretic behaviors in conventional type-II superconductors. These features may be explained by the existence of reversible edge currents at low field, which are intrinsic properties of the p-wave superconducting order parameter. The torque magnetometry turns to be an effective tool to probe the exotic properties in unconventional superconductors. Our results clarify the phase-disordering nature of the superconducting transition in high Tc superconductors, and reveal a possible edge current in Sr2RuO 4. Further exploring other systems with the torque magnetometry may result in more interesting findings.

Li, Lu

117

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

118

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...

119

Detection of fatigue cracks and torque loss in bolted joints  

NASA Astrophysics Data System (ADS)

Fatigue crack growth during the service life of aging aircraft is a critical issue and monitoring of such cracks in structural hotspots is the goal of this research. This paper presents a procedure for classification and detection of cracks generated in bolted joints which are used at numerous locations in aircraft structures. Single lap bolted joints were equipped with surface mounted piezoelectric (pzt) sensors and actuators and were subjected to cyclic loading. Crack length measurements and sensor data were collected at different number of cycles and with different torque levels. A classification algorithm based on Support Vector Machines (SVMs) was used to compare signals from a healthy and damaged joint to classify fatigue damage at the bolts. The algorithm was also used to classify the amount of torque in the bolt of interest and determine if the level of torque affected the quantification and localization of the crack emanating from the bolt hole. The results show that it is easier to detect the completely loose bolt but certain changes in torque, combined with damage, can produce some non-unique classifier solutions.

Coelho, Clyde K.; Das, Santanu; Chattopadhyay, Aditi; Papandreou-Suppappola, Antonia; Peralta, Pedro

2007-04-01

120

Metaphor priming in sentence production: Concrete pictures affect abstract language production.  

PubMed

People speak metaphorically about abstract concepts-for instance, a person can be "full of love" or "have a lot of love to give." Over the past decade, research has begun to focus on how metaphors are processed during language comprehension. Much of this work suggests that understanding a metaphorical expression involves activating brain and body systems involved in perception and motor control. However, no research to date has asked whether the same is true while speakers produce language. We address this gap using a sentence production task. Its results demonstrate that visually activating a concrete source domain can trigger the use of metaphorical language drawn from that same concrete domain, even in sentences that are thematically unrelated to the primes, a metaphorical priming effect. This effect suggests that conceptual metaphors play a part in language production. It also shows that activation in the perceptual system that is not part of an intended message can nevertheless influence sentence formulation. PMID:25443987

Sato, Manami; Schafer, Amy J; Bergen, Benjamin K

2015-03-01

121

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

122

Quantifying Magnetic Stellar Wind Torques  

NASA Astrophysics Data System (ADS)

In order to be able to understand the evolution of stellar spin rates and differential rotation, it is necessary to have a rigorous theory for predicting angular momentum loss via magnetic stellar winds that is applicable over a wide range of conditions. Based upon the results of multidimensional, numerical simulations and semi-analytic calculations, we present an improved formulation for predicting the stellar wind torque, which is valid for varying degrees of magnetization in the wind, as well as for stellar spin rates that range from the slow- to the fast-magnetic-rotator regimes.

Matt, Sean; MacGregor, K. B.; Pinsonneault, M. H.; Greene, T. P.

2011-01-01

123

Torque limited drive for manual valves  

DOEpatents

The present invention is directed to a torque-limiting handwheel device for preventing manual valves from being damaged due to the application of excessive torque during the opening or closing operation of the valves. Torque can only be applied when ridges in the handwheel assembly engage in channels machined in the face of the baseplate. The amount of torque required for disengagement of the ridges from the channels is determined by the force exerted by various Bellville springs and the inclination of the side faces of the channels.

Elliott, Philip G. (Metropolis, IL); Underwood, Daniel E. (Paducah, KY)

1989-01-01

124

Herbivore and fungal pathogen exclusion affects the seed production of four common grassland species.  

PubMed

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

125

Dimensionality of joint torques and muscle patterns for reaching.  

PubMed

Muscle activities underlying many motor behaviors can be generated by a small number of basic activation patterns with specific features shared across movement conditions. Such low-dimensionality suggests that the central nervous system (CNS) relies on a modular organization to simplify control. However, the relationship between the dimensionality of muscle patterns and that of joint torques is not fixed, because of redundancy and non-linearity in mapping the former into the latter, and needs to be investigated. We compared the torques acting at four arm joints during fast reaching movements in different directions in the frontal and sagittal planes and the underlying muscle patterns. The dimensionality of the non-gravitational components of torques and muscle patterns in the spatial, temporal, and spatiotemporal domains was estimated by multidimensional decomposition techniques. The spatial organization of torques was captured by two or three generators, indicating that not all the available coordination patterns are employed by the CNS. A single temporal generator with a biphasic profile was identified, generalizing previous observations on a single plane. The number of spatiotemporal generators was equal to the product of the spatial and temporal dimensionalities and their organization was essentially synchronous. Muscle pattern dimensionalities were higher than torques dimensionalities but also higher than the minimum imposed by the inherent non-negativity of muscle activations. The spatiotemporal dimensionality of the muscle patterns was lower than the product of their spatial and temporal dimensionality, indicating the existence of specific asynchronous coordination patterns. Thus, the larger dimensionalities of the muscle patterns may be required for CNS to overcome the non-linearities of the musculoskeletal system and to flexibly generate endpoint trajectories with simple kinematic features using a limited number of building blocks. PMID:24624078

Russo, Marta; D'Andola, Mattia; Portone, Alessandro; Lacquaniti, Francesco; d'Avella, Andrea

2014-01-01

126

Dimensionality of joint torques and muscle patterns for reaching  

PubMed Central

Muscle activities underlying many motor behaviors can be generated by a small number of basic activation patterns with specific features shared across movement conditions. Such low-dimensionality suggests that the central nervous system (CNS) relies on a modular organization to simplify control. However, the relationship between the dimensionality of muscle patterns and that of joint torques is not fixed, because of redundancy and non-linearity in mapping the former into the latter, and needs to be investigated. We compared the torques acting at four arm joints during fast reaching movements in different directions in the frontal and sagittal planes and the underlying muscle patterns. The dimensionality of the non-gravitational components of torques and muscle patterns in the spatial, temporal, and spatiotemporal domains was estimated by multidimensional decomposition techniques. The spatial organization of torques was captured by two or three generators, indicating that not all the available coordination patterns are employed by the CNS. A single temporal generator with a biphasic profile was identified, generalizing previous observations on a single plane. The number of spatiotemporal generators was equal to the product of the spatial and temporal dimensionalities and their organization was essentially synchronous. Muscle pattern dimensionalities were higher than torques dimensionalities but also higher than the minimum imposed by the inherent non-negativity of muscle activations. The spatiotemporal dimensionality of the muscle patterns was lower than the product of their spatial and temporal dimensionality, indicating the existence of specific asynchronous coordination patterns. Thus, the larger dimensionalities of the muscle patterns may be required for CNS to overcome the non-linearities of the musculoskeletal system and to flexibly generate endpoint trajectories with simple kinematic features using a limited number of building blocks. PMID:24624078

Russo, Marta; D'Andola, Mattia; Portone, Alessandro; Lacquaniti, Francesco; d'Avella, Andrea

2014-01-01

127

Reduction of torque ripple in brushless DC motors  

Microsoft Academic Search

For permanent magnet (PM) brushless DC motors, torque ripple, is an important origin of vibration, acoustic noise and speed fluctuation. In this paper, the output torque profile of a PM motor with one phase energized is decomposed into the commutation torque, the reluctance torque and the armature reaction according to their source origins. It verifies that the output torque profile

S. M. Hwang; D. K. Lieu

1995-01-01

128

Motion Control Systems with Positive Joint Torque Feedback  

Microsoft Academic Search

Positive joint torque feedback (JTF) can compensate the detrimental effects of load torques on position tracking perfor- mance. However, with (real world) nonideal torque sources, simple unity gain positive torque feedback can actually deteriorate the performance, or even result in instability. In this work, a new joint torque feedback approach is proposed which takes into ac- count the actuator's finite

Farhad Aghili; Martin Buehler; John M. Hollerbach

129

A Novel Direct Torque Control Algorithm for IPMSM With Minimum Harmonics and Torque Ripples  

Microsoft Academic Search

This paper describes a new direct torque control algorithm for interior permanent-magnet synchronous motor (IPMSM) to improve the performance of hysteresis direct torque control (HDTC). The algorithm uses the output of two hysteresis controllers used in the traditional HDTC to determine two adjacent active vectors. It also uses the magnitude of the torque error and stator flux linkage position to

Kayhan Gulez; Ali Ahmed Adam; Halit Pastaci

2007-01-01

130

12Sector Methodology of Torque Ripple Reduction in a Direct Torque Controlled Induction Motor Drive  

Microsoft Academic Search

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. 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 stator flux linkages. This

Borra Suresh Kumar; R. A. Gupta; Rajesh Kumar

2006-01-01

131

Magnetically Torqued Thin Accretion Disks  

E-print Network

We compute the properties of a geometrically thin, steady accretion disk surrounding a central rotating, magnetized star. The magnetosphere is assumed to entrain the disk over a wide range of radii. The model is simplified in that we adopt two (alternate) ad hoc, but plausible, expressions for the azimuthal component of the magnetic field as a function of radial distance. We find a solution for the angular velocity profile tending to corotation close to the central star, and smoothly matching a Keplerian curve at a radius where the viscous stress vanishes. The value of this ''transition'' radius is nearly the same for both of our adopted B-field models. We then solve analytically for the torques on the central star and for the disk luminosity due to gravity and magnetic torques. When expressed in a dimensionless form, the resulting quantities depend on one parameter alone, the ratio of the transition radius to the corotation radius. For rapid rotators, the accretion disk may be powered mostly by spin-down of the central star. These results are independent of the viscosity prescription in the disk. We also solve for the disk structure for the special case of an optically thick alpha disk. Our results are applicable to a range of astrophysical systems including accreting neutron stars, intermediate polar cataclysmic variables, and T Tauri systems.

W. Kluzniak; S. Rappaport

2007-10-01

132

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

133

Spatial pattern affects diversity-productivity relationships in experimental meadow communities  

NASA Astrophysics Data System (ADS)

Plant species create aggregations of conspecifics as a consequence of limited seed dispersal, clonal growth and heterogeneous environment. Such intraspecific aggregation increases the importance of intraspecific competition relative to interspecific competition which may slow down competitive exclusion and promote species coexistence. To examine how spatial aggregation impacts the functioning of experimental assemblages of varying species richness, eight perennial grassland species of different growth form were grown in random and aggregated patterns in monocultures, two-, four-, and eight-species mixtures. In mixtures with an aggregated pattern, monospecific clumps were interspecifically segregated. Mixed model ANOVA was used to test (i) how the total productivity and productivity of individual species is affected by the number of species in a mixture, and (ii) how these relationships are affected by spatial pattern of sown plants. The main patterns of productivity response to species richness conform to other studies: non-transgressive overyielding is omnipresent (the productivity of mixtures is higher than the average of its constituent species so that the net diversity, selection and complementarity effects are positive), whereas transgressive overyielding is found only in a minority of cases (average of log(overyielding) being close to zero or negative). The theoretical prediction that plants in a random pattern should produce more than in an aggregated pattern (the distances to neighbours are smaller and consequently the competition among neighbours stronger) was confirmed in monocultures of all the eight species. The situation is more complicated in mixtures, probably as a consequence of complicated interplay between interspecific and intraspecific competition. The most productive species ( Achillea, Holcus, Plantago) were competitively superior and increased their relative productivity with mixture richness. The intraspecific competition of these species is stronger than that of most other species. The aggregated pattern in the full mixture increased the survival of subordinate species, and consequently, we conclude that an aggregated pattern can promote species coexistence (or at least postpone competitive exclusion), particularly in comparison with homogeneously sown mixtures.

Lamošová, Tereza; Doležal, Ji?í; Lanta, Vojt?ch; Lepš, Jan

2010-05-01

134

Torque Ripple Suppression Control for PM Motor Considering the Bandwidth of Torque Meter  

NASA Astrophysics Data System (ADS)

PM motor drive systems are widely used for industrial drives. However, PM motors basically produce the torque ripple due to the fluctuation of the magnetic field distribution. Dead time of the inverter, offset of sensors and current measurement errors lead to the torque ripple, too. The torque ripple leads vibration noises. In this paper, we proposed a torque ripple suppression method based on perfect tracking control, in which the torque ripple is measured by a low-bandwidth sensor. Finally, we show the advantages of the proposed method by simulations and experiments with a SPMSM.

Nakamura, Kento; Fujimoto, Hiroshi; Fujitsuna, Masami

135

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

136

Casimir torque on a cylindrical gear  

NASA Astrophysics Data System (ADS)

I utilize effective field theory(EFT) techniques to calculate the Casimir torque on a cylindrical gear in the presence of a polarizable but neutral object and present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

Vaidya, Varun

2014-08-01

137

Torques and instabilities in intermediate polars  

Microsoft Academic Search

The observed spin periods of the primaries in intermediate polars require the presence of torques additional to the standard expectation of material and magnetic torques from an accretion disc. In an extension of earlier work by Wickramasinghe, Wu and Ferrario, from rates of mass transfer deduced from optical and X-ray fluxes, and assuming surface magnetic fields similar to those observed

Brian Warner; Karl Schwarzschild Strasse

1996-01-01

138

Parasitic Torques of Saturised Asynchronous Motors  

Microsoft Academic Search

The paper deals with the analysis of field harmonics in an asynchronous machine. It is proved that with increasing saturation of the magnetic circuit, the influence of the higher space harmonics on the field form is reduced. This causes reduction of the parasitic torques. Results of theoretical calculations have been compared with measurements of synchronous and asynchronous parasitic torques, which

Michael Erlicki

1972-01-01

139

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

140

The Casimir Torque on a Cylindrical Gear  

E-print Network

We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

Vaidya, Varun

2013-01-01

141

The Casimir Torque on a Cylindrical Gear  

E-print Network

We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

Varun Vaidya

2013-09-02

142

New Calculations of Stellar Wind Torques  

NASA Astrophysics Data System (ADS)

Using numerical simulations of magnetized stellar winds, we carry out a parameter study to find the dependence of the stellar wind torque on observable parameters. We find that the power-law dependencies of the torque on parameters is significantly different than what has been used in all spin evolution models to date.

Matt, Sean P.; Pudritz, Ralph E.

2009-02-01

143

Direct torque control of permanent magnet drives  

Microsoft Academic Search

Many permanent magnet motor drives use an open loop form of torque control, based on the assumption that output torque is proportional to applied current. In a practical motor this assumption may not always be correct, due to suboptimal alignment of magnets, nonuniformity of magnetic material, current sensor nonlinearities, and current controller limitations. These factors, together with nonoptimized current references,

Chris French; Paul Acarnley

1996-01-01

144

Torques in atmospheres of rotating planets  

E-print Network

Molecular motion in combination with planetary rotation and gravity causes a torque in gas when seen from a coordinate system fixed in the planet. The torque is caused by the difference in centrifugal forces when gas molecules are moving along or opposite to the planets rotation.

Jonsson, David

2010-01-01

145

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

146

In-line rotating capacitive torque sensor  

DOEpatents

Disclosed are 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. 18 figures.

Kronberg, J.W.

1991-09-10

147

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

148

76 FR 63822 - Special Conditions: Gulfstream Aerospace LP (GALP) Model G280 Airplane, Limit Engine Torque Loads...  

Federal Register 2010, 2011, 2012, 2013, 2014

...novel or unusual design feature involving engine size and related torque load that affect sudden engine-stoppage conditions. Discussion The size, configuration, and failure modes of jet engines have changed considerably from those...

2011-10-14

149

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

150

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

151

Ovarian steroids affect prostaglandin production in equine endometrial cells in vitro.  

PubMed

This study aimed to evaluate the influence of ovarian steroids on equine endometrial epithelial and stromal cells, specifically i) prostaglandin (PG) production in a time-dependent manner, ii) specific PG synthases mRNA transcription and protein expression, and iii) cell proliferation. After passage I, cells were exposed to vehicle, oxytocin (OT, positive control, 10(-7) M), progesterone (P4, 10(-7) M), 17? estradiol (E2, 10(-9) M), or P4+E2 for 12, 24, 48, or 72?h. Following treatment, PG concentration was determined using the direct enzyme immunoassay (EIA) method. Alterations in PG synthases mRNA transcriptions, PG synthases protein expression, and cell proliferation in response to the treatments were determined after 24?h using real-time PCR, western blot, or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide respectively. After 24?h, E2 and P4+E2 increased PGE2 and PGF2? secretion as well as specific prostaglandin-endoperoxide synthase-2 (PTGS2), PGE2 synthases (PGES), and PGF2? synthases (PGFS) expression in the epithelial cells (P<0.05). Additionally, E2 and P4+E2 increased PTGS2 expression in stromal cells after 24?h (P<0.05). In stromal cells, P4+E2 increased PGE2 production as well as PGES expression after 24?h (P<0.05). Both E2 and P4+E2 increased PGF2? production by stromal cells after 24?h (P<0.05). Ovarian steroids affected proliferation of stromal and epithelial cells during the 24-h incubation period (P<0.05). We provide evidence that ovarian steroids affect PG production in equine endometrial cells, upregulating PTGS2, PGES, and PGFS expression. Ovarian steroid-stimulated PG production could be an important mechanism occurring in the equine endometrium that is involved in the regulation of the estrous cycle and early pregnancy. PMID:24481966

Szóstek, Anna Z; Galvão, António M; Ferreira-Dias, Graça M; Skarzynski, Dariusz J

2014-03-01

152

Torque control of engine clutch to improve the driving quality of hybrid electric vehicles  

Microsoft Academic Search

As a powertrain for hybrid electric vehicles (HEVs), the automatic transmission (AT) is not only convenient for the driver\\u000a but also reduces hybridization costs because the existing production line is used to produce the AT. However, it has low fuel\\u000a economy due to the torque converter. To overcome this disadvantage, this paper studies HEVs equipped an AT without a torque

H. S. Hwang; D. H. Yang; H. K. Choi; H. S. Kim; S. H. Hwang

2011-01-01

153

Friction coefficient, torque estimation, smooth shift control law for an automatic power transmission  

Microsoft Academic Search

For shift quality improvement, torque sensors are currently too expensive to be used on production vehicles. To achieve smooth\\u000a acceleration shift, the reference trajectory of the clutch slip speed for accomplishing the shift process within a designated\\u000a shift completion time and its relationship with the clutch actuating torque were suggested by Jeong and Lee (1999). In order\\u000a to facilitate the

Heon-Sul Jeong; Kyo-Ill Lee

2000-01-01

154

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

155

Nuclear DNA content affects the productivity of conifer forests by altering hydraulic architecture  

NASA Astrophysics Data System (ADS)

Predictions of future global climate rely on feedbacks between terrestrial vegetation and the global carbon cycle, but the exact mechanisms underlying this relationship are still being discussed. One of the key knowledge gaps lies on the scaling of cellular processes to the ecosystem level. Here we examine whether an under-explored plant trait, inter-specific variation in the bulk amount of DNA in unreplicated somatic cells (2C DNA content), can explain inter-specific variation in the maximum productivity of conifer forests. We expected 2C DNA content to be negatively related to conifer productivity because: 1) it is positively correlated with cell volume (which, in turn, potentially affects structural features such as leaf mass area, a strong predictor of photosynthetic capacity); 2) it is positively correlated with stomatal size (with larger stomata leading to lower overall stomatal conductance and, by extension, lower CO2 uptake); and 3) larger genome sizes may reduce P availability in RNA (which has been hypothesized to slow growth). We present the results of regression and independent contrasts in different monospecific forests encompassing a 52º latitudinal gradient, each being dominated by 1 of 35 different conifer species. Contrary to expectations, we observed a positive correlation between genome size and maximum Gross Primary Productivity (R2 = 0.47) and also between genome size maximum tree height (R2 = 0.27). This correlation was apparently driven by the effects of genome size on stem hydraulics, since 2C DNA was positively correlated with wood density (R2 = 0.40) and also with resistance to cavitation (P50, R2 = 0.28). That is, increased genome sizes have a positive effect on the productivity of conifer forests by affecting the vascular tissues to increase their capacity for water transport. Our results shed a new light on the evolution of the vascular system of conifer forests and how they affect ecosystem productivity, and indicate the potential to further explore the trait of genome size for understanding global patterns of forest productivity.

Alday, Josu; Resco de Dios, Víctor

2014-05-01

156

Intracolonial genetic variation affects reproductive skew and colony productivity during colony foundation in a parthenogenetic termite  

PubMed Central

Background In insect societies, intracolonial genetic variation is predicted to affect both colony efficiency and reproductive skew. However, because the effects of genetic variation on these two colony characteristics have been tested independently, it remains unclear whether they are affected by genetic variation independently or in a related manner. Here we test the effect of genetic variation on colony efficiency and reproductive skew in a rhinotermitid termite, Reticulitermes speratus, a species in which female-female pairs can facultatively found colonies. We established colonies using two types of female-female pairs: colonies founded by sisters (i.e., sister-pair colonies) and those founded by females from different colonies (i.e., unrelated-pair colonies). Colony growth and reproductive skew were then compared between the two types of incipient colonies. Results At 15 months after colony foundation, unrelated-pair colonies were larger than sister-pair colonies, although the caste ratio between workers and nymphs, which were alternatively differentiated from young larvae, did not differ significantly. Microsatellite DNA analyses of both founders and their parthenogenetically produced offspring indicated that, in both sister-pair and unrelated-pair colonies, there was no significant skew in the production of eggs, larvae, workers and soldiers. Nymph production, however, was significantly more skewed in the sister-pair colonies than in unrelated-pair colonies. Because nymphs can develop into winged adults (alates) or nymphoid reproductives, they have a higher chance of direct reproduction than workers in this species. Conclusions Our results support the idea that higher genetic variation among colony members could provide an increase in colony productivity, as shown in hymenopteran social insects. Moreover, this study suggests that low genetic variation (high relatedness) between founding females increases reproductive skew via one female preferentially channeling her relatives along the reproductive track. This study thus demonstrated that, in social insects, intracolonial genetic variation can simultaneously affect both colony efficiency and reproductive skew. PMID:25123355

2014-01-01

157

Switching Torque Converter: Concept and Preliminary Implementation  

NASA Astrophysics Data System (ADS)

It is preferable to refrain from switching the torque in mechanical systems because the abrupt change tends to cause vibration and noise. However, such vibration can be beneficial if it is used to store mechanical energy. Moreover, torque switching operations at higher frequencies are becoming possible because of the recent advances in clutch devices. This paper describes a novel torque conversion mechanism based on torque switching operations. The fundamental principle of the mechanism is the reciprocal translation between the work to and from axles and the rotational energy of a flywheel. Clutches are used to intermittently connect or disconnect the axles with the flywheel; the output torque is controlled by changing the time ratio of the connection. By performing switching operations at a higher frequency, almost continuous torque conversion can be realized. A prototype was created using electrorheological fluid clutches, and it showed the potential for torque conversion. The performance of the prototype was also analyzed by numerical simulation; this showed that the prototype worked in accordance with the principle. Moreover, the potential capability of the principle was investigated using a numerical model and the results suggest that by improving the mechanical design, a considerable improvement in performance is possible.

Hirota, Koichi; Ikei, Yasushi

158

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

PubMed

Surgical operating rooms are cost-intensive parts of health service production. Managing operating units efficiently is essential when hospitals and healthcare systems aim to maximize health outcomes with limited resources. Previous research about operating room management has focused on studying the effect of management practices and decisions on efficiency by utilizing mainly modeling approach or before-after analysis in single hospital case. The purpose of this research is to analyze the synergic effect of strategic decisions and operative management practices on operating room productivity and to use a multiple case study method enabling statistical hypothesis testing with empirical data. 11 hypotheses that propose connections between the use of strategic and operative practices and productivity were tested in a multi-hospital study that included 26 units. The results indicate that operative practices, such as personnel management, case scheduling and performance measurement, affect productivity more remarkably than do strategic decisions that relate to, e.g., units' size, scope or academic status. Units with different strategic positions should apply different operative practices: Focused hospital units benefit most from sophisticated case scheduling and parallel processing whereas central and ambulatory units should apply flexible working hours, incentives and multi-skilled personnel. Operating units should be more active in applying management practices which are adequate for their strategic orientation. PMID:21814829

Peltokorpi, Antti

2011-12-01

159

Mutations in nicastrin protein differentially affect amyloid beta-peptide production and Notch protein processing.  

PubMed

The ?-secretase complex is responsible for intramembrane processing of over 60 substrates and is involved in Notch signaling as well as in the generation of the amyloid ?-peptide (A?). Aggregated forms of A? have a pathogenic role in Alzheimer disease and, thus, reducing the A? levels by inhibiting ?-secretase is a possible treatment strategy for Alzheimer disease. Regrettably, clinical trials have shown that inhibition of ?-secretase results in Notch-related side effects. Therefore, it is of great importance to find ways to inhibit amyloid precursor protein (APP) processing without disturbing vital signaling pathways such as Notch. Nicastrin (Nct) is part of the ?-secretase complex and has been proposed to be involved in substrate recognition and selection. We have investigated how the four evenly spaced and conserved cysteine residues in the Nct ectodomain affect APP and Notch processing. We mutated these cysteines to serines and analyzed them in cells lacking endogenous Nct. We found that two mutants, C213S (C2) and C230S (C3), differentially affected APP and Notch processing. Both the formation of A? and the intracellular domain of amyloid precursor protein (AICD) were reduced, whereas the production of Notch intracellular domain (NICD) was maintained on a high level, although C230S (C3) showed impaired complex assembly. Our data demonstrate that single residues in a ?-secretase component besides presenilin are able to differentially affect APP and Notch processing. PMID:21768095

Pamrén, Annelie; Wanngren, Johanna; Tjernberg, Lars O; Winblad, Bengt; Bhat, Ratan; Näslund, Jan; Karlström, Helena

2011-09-01

160

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

161

Torquing preload in a lubricated bolt  

NASA Technical Reports Server (NTRS)

The tension preload obtained by torquing a 7/8 in. diam UNC high strength bolt was determined for lubricated and dry conditions. Consistent preload with a variation of + or - 3% was obtained when the bolt head area was lubricated prior to each torque application. Preload tensions nearly 70% greater than the value predicted with the commonly used formula occurred with the lubricated bolt. A reduction to 39% of the initial preload was observed during 50 torque applications without relubrication. Little evidence of wear was noted after 203 cycles of tightening.

Seegmiller, H. L.

1978-01-01

162

Nedocromil sodium acts directly on human B cells to inhibit immunoglobulin production without affecting cell growth.  

PubMed Central

The effect of nedocromil sodium (NES) on human immunoglobulin (Ig) isotypes, IgG subclasses and IgA subclasses was studied. NES inhibited IgM and IgA1 production from human lymphoblastoid B-cell lines CBL and GM-1056, respectively, in a dose-dependent fashion. This inhibition was not due to decreased cell growth as cell proliferation was not affected by NES and cell viability was always greater than 98%. Of the various cytokines tested, interleukin-4 (IL-4) reduced the NES-induced inhibition of Ig production, whereas other cytokines, including IL-1 beta, IL-2, IL-3, IL-5, IL-6, interferon-alpha (IFN-alpha), IFN-gamma, granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (Epo) failed to do so. The reducing effect of IL-4 was blocked by anti-IL-4 antibody but not by control IgG. Moreover, IFN-alpha and IFN-gamma, but not GM-CSF, overcame the reducing effect of IL-4. NES also inhibited production of IgM, IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2 by tonsillar B cells stimulated with Staphylococcus aureus Cowan strain I (SAC) and IL-6 without affecting proliferation. This inhibition was reduced by IL-4 specifically. These results indicate that in addition to its anti-allergic function, NES may act as a B-cell regulatory reagent. PMID:8132219

Kimata, H; Fujimoto, M; Mikawa, H

1994-01-01

163

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

Code of Federal Regulations, 2014 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5985 What are my alternatives for...

2014-07-01

164

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

Code of Federal Regulations, 2014 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Testing and Initial Compliance Requirements for Tire Production Affected Sources § 63.5996...

2014-07-01

165

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

Code of Federal Regulations, 2013 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Cord Production Affected Sources § 63.5987 What are my alternatives...

2013-07-01

166

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

Code of Federal Regulations, 2014 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Cord Production Affected Sources § 63.5987 What are my alternatives...

2014-07-01

167

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

Code of Federal Regulations, 2011 CFR

...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Continuous Compliance Requirements for Tire Production Affected Sources § 63.6004 How do I...

2011-07-01

168

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

Code of Federal Regulations, 2010 CFR

...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Testing and Initial Compliance Requirements for Tire Production Affected Sources § 63.5996...

2010-07-01

169

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

Code of Federal Regulations, 2011 CFR

...the Emission Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of Environment ...Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial...

2011-07-01

170

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

Code of Federal Regulations, 2013 CFR

...the Emission Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of Environment ...Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial...

2013-07-01

171

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

...the Emission Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of Environment ...Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial...

2010-07-01

172

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

Code of Federal Regulations, 2012 CFR

...the Emission Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of Environment ...Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial...

2012-07-01

173

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

Code of Federal Regulations, 2014 CFR

...the Emission Limits for Tire Production Affected Sources 6 Table 6 to Subpart XXXX of Part 63 Protection of Environment ...Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 6 Table 6 to Subpart XXXX of Part 63—Initial...

2014-07-01

174

Instantaneous Torque Estimation in Sensorless Direct-Torque-Controlled Brushless DC Motors  

Microsoft Academic Search

A key issue in the direct torque control of permanent-magnet brushless dc motors is the estimation of the instantaneous electromagnetic torque, while sensorless control is often advantageous. A sliding-mode observer is employed to estimate the nonsinusoidal back-electromotive-force waveform, and a simplified extended Kalman filter is used to estimate the rotor speed. Both are combined to calculate the instantaneous electromagnetic torque.

Yong Liu; Zi Qiang Zhu; David Howe

2006-01-01

175

Soft torque rotary system reduces drillstring failures  

SciTech Connect

This paper reports that the use of the soft torque system has significantly reduced torque fluctuations (up to 80%), torsional drillstring vibrations, and bit slip-stick conditions to help reduce drillstring failures and improve penetration rates in deep directional wells. The system was instrumental in eliminating expensive ($5-10 million) drillstring failures on Well SL 531 No. 3, a complex directional well in Mobile Bay. The soft torque rotary system attenuates and interrupts the torsional oscillations of the drillstring and thus prevents the buildup of energy in torsional waves that are reflected back and forth between the bit and the rotary table. The soft torque rotary system can be installed on any rig equipped with an independent electronically driven rotary table or top drive. The system is relatively inexpensive and easy to install.

Javanmardi, K.; Gaspard, D. (Shell Offshore Inc., New Orleans, LA (United States))

1992-10-12

176

Damping assembly for a torque converter clutch  

SciTech Connect

This patent describes a turbine damped torque converter and clutch. It comprises: a pressure plate; a torque converter turbine; a torque converter impeller; means including a control chamber for the pressure plate means for controlling the apply and release of the clutch for engaging the clutch with the impeller; a torque converter output shaft; a planetary gear arrangement including an input gear drivingly connected with the pressure plate, a reaction gear drivingly connected with the turbine, an output member drivingly connected with the output shaft and pinion gear means meshing with the input gear and the reaction gear for drivingly interconnecting the turbine and the pressure plate at a drive ratio of the turbine to the pressure plate of less than 1:1; and one-way drive means disposed between the turbine and the output shaft for preventing the turbine from overrunning the output shaft.

Dull, D.C.

1989-12-26

177

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

178

Oral administration of ?-aminobutyric acid affects heat production in a hot environment in resting humans  

PubMed Central

Background Central administration of ?-amino butyric acid (GABA) induces lower body temperature in animals in hot ambient air. However, it is still unknown whether oral GABA administration affects temperature regulation at rest in a hot environment in humans. Therefore, in the present study, we specifically hypothesized that systemic administration of GABA in humans would induce hypothermia in a hot environment and that this response would be observed in association with decreased heat production. Methods Eight male participants drank a 200-ml sports drink with 1 g of GABA (trial G) or without GABA (trial C), then rested for 30 minutes in a sitting position in a hot environment (ambient air temperature 33°C, relative humidity 50%). Results We found that changes in esophageal temperature from before drinking the sports drink were lower in trial G than in trial C (-0.046 ± 0.079°C vs 0.001 ± 0.063°C; P < 0.05), with lower heat production calculated by oxygen consumption (41 ± 5 W/m2 vs 47 ± 8 W/m2; P < 0.05). Conclusions In this study, we have demonstrated that a single oral administration of GABA induced a larger decrease in body core temperature compared to a control condition during rest in a hot environment and that this response was concomitant with a decrease in total heat production. PMID:22738209

2012-01-01

179

Compliant humanoid robot control by the torque transformer  

Microsoft Academic Search

This paper presents a new control architecture for compliant motion control and safe physical interaction between humanoid robot and human. One of the key technologies in this framework is the torque transformer, which enables the implementation of joint torque control on the traditional joint position controlled robots. In this framework, the torque control is accomplished by converting desired joint torque

Taizo Yoshikawa; Oussama Khatib

2009-01-01

180

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

181

Selecting custom torque prescriptions for the straight-wire appliance.  

PubMed

Selecting custom torque prescriptions based on the treatment needs of each patient can reduce the amount of routine archwire torque adjustment needed and speed torque correction, thus reducing the total treatment time. Using the appropriate torque prescription prevents iatrogenic torque problems and allows most torque corrections to be done earlier with more resilient nickel-titanium and beta-titanium wires. As a result, fewer time-consuming final torque adjustments are needed with stainless steel finishing wires, resulting in shorter treatment time. PMID:23540633

Johnson, Earl

2013-04-01

182

Validation of dynamic torque response of an electrorheological (ER) clutch  

NASA Astrophysics Data System (ADS)

It is now well established that using actuators, which have faster speeds of response than d.c. servomotors, can solve the positional errors of the robot arms. One of the possible robotic actuators can be an electro-rheological (ER) clutch. To justify this objective, the authors measured the output torque response of a co-axial ER clutch. However, due to the dynamic inefficiency of a torque transducer, the measured torque response is inaccurate for analytical studies. Therefore, this measured torque is signal processed by using the transfer functions of this torque sensor and a filter to yield the ER torque response. The validity of this ER torque is investigated by comparing the numerical errors between the measured torque and its inverse torque response. From the torque error analysis, it is concluded that the ER clutch can be an actuator to improve the positioning accuracies of the robot arms.

Tan, K. P.; Stanway, R.; Bullough, W. A.

2006-02-01

183

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

184

Torque on an exoplanet from an anisotropic evaporative wind  

E-print Network

Winds from short-period Earth and Neptune mass exoplanets, driven by high energy radiation from a young star, may evaporate a significant fraction of a planet's mass. If the momentum flux from the evaporative wind is not aligned with the planet/star axis, then it can exert a torque on the planet's orbit. Using steady-state one-dimensional evaporative wind models we estimate this torque using a lag angle that depends on the product of the speed of the planet's upper atmosphere and a flow timescale for the wind to reach its sonic radius. We also estimate the momentum flux from time-dependent one-dimensional hydrodynamical simulations. We find that only in a very narrow regime in planet radius, mass and stellar radiation flux is a wind capable of exerting a significant torque on the planet's orbit. Similar to the Yarkovsky effect, the wind causes the planet to drift outward if atmospheric circulation is prograde (super-rotating) and in the opposite direction if the circulation is retrograde. A close-in super Ear...

Teyssandier, Jean; Adams, Fred C; Quillen, Alice C

2015-01-01

185

Decreased summer drought affects plant productivity and soil carbon dynamics in Mediterranean woodland  

NASA Astrophysics Data System (ADS)

Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. The throughfall manipulation experiment started in 2004 and we report data up to the 2009 growing season. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 50 % and 220 %, respectively, as compared to control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction of precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodland. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long term soil C stocks.

Cotrufo, M. F.; Alberti, G.; Inglima, I.; Marjanovi?, H.; Lecain, D.; Zaldei, A.; Peressotti, A.; Miglietta, F.

2011-06-01

186

Decreased summer drought affects plant productivity and soil carbon dynamics in a Mediterranean woodland  

NASA Astrophysics Data System (ADS)

Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 58 % and 220 %, respectively, as compared to the control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction in precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodlands. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long-term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long-term soil C stocks.

Cotrufo, M. F.; Alberti, G.; Inglima, I.; Marjanovi?, H.; Lecain, D.; Zaldei, A.; Peressotti, A.; Miglietta, F.

2011-09-01

187

EMG-Torque Estimation of Constant-Posture, Quasi-Constant-Torque Contractions at Varied Joint Angles  

E-print Network

EMG-Torque Estimation of Constant-Posture, Quasi- Constant-Torque Contractions at Varied Joint relates the simultaneous biceps/triceps surface electromyogram (EMG) of 12 subjects to elbow torque at seven joint angles during constant-posture, quasi-constant-torque contractions. Advanced EMG amplitude

Clancy, Ted

188

Robust speed control of IM with torque feedforward control  

Microsoft Academic Search

The authors describe a digital signal processor-based (DSP-based) robust speed control for an induction motor (IM) with the load-torque observer and the torque feedforward control. In the proposed system, the load torque is estimated by the minimal-order state observer based on the torque component of a vector-controlled IM. Using the load-torque observer, a speed controller can be provided with a

Makoto Iwasaki; N. Matusi

1993-01-01

189

Consumers' willingness to pay for organic food : Factors that affect it and variation per organic product type  

Microsoft Academic Search

Purpose – Seeks to provide answers to two questions: is willingness to pay (WTP) for organic products influenced by the same set of factors that affect purchasing of conventional foods? Does WTP for organic products vary according to different food categories? Design\\/methodology\\/approach – Purchasers were approached during their food shopping in retail chains in Athens in July 2003. Sample inclusion

Athanasios Krystallis; George Chryssohoidis

2005-01-01

190

SigF Controls Carotenoid Pigment Production and Affects Transformation Efficiency and Hydrogen Peroxide Sensitivity in Mycobacterium smegmatis  

Microsoft Academic Search

Carotenoids are complex lipids that are known for acting against photodynamic injury and free radicals. We demonstrate here that F is required for carotenoid pigment production in Mycobacterium smegmatis .W e further show that a sigF mutant exhibits a transformation efficiency 104-fold higher than that of the parental strain, suggesting that F regulates the production of components affecting cell wall

Roberta Provvedi; D. Kocincova; Valentina Dona; Daniel Euphrasie; Mamadou Daffe; Gilles Etienne; Riccardo Manganelli; Jean-Marc Reyrat

2008-01-01

191

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

192

Microvesicle formulations used in topical drugs and cosmetics affect product efficiency, performance and allergenicity.  

PubMed

Attempts to improve the formulations of topical products are continuing processes (ie, to increase cosmetic performance, enhance effects, and protect ingredients from degradation). The development of micro- and nanovesicular systems has led to the marketing of topical drugs and cosmetics that use these technologies. Several articles have reported improved clinical efficacy by the encapsulation of pharmaceuticals in vesicular systems, and the numbers of publications and patents are rising. Some vesicular systems may deliver the drug deeper in the skin as compared to conventional vehicles, or even make transdermal delivery more efficient for a number of drugs. Vesicular systems may also allow a more precise drug delivery to the site of action (ie, the hair follicles) and thereby minimize the applied drug concentration, reducing potential side effects. On the other hand, this may increase the risk of other side effects. Few case reports have suggested that microvesicle formulations may affect the allergenicity of topical products. This article gives an overview of the current knowledge about the topical use of microvesicular systems and the dermatoallergologic aspects. PMID:20920408

Madsen, Jakob Torp; Andersen, Klaus Ejner

2010-01-01

193

Developmental and communicative factors affecting VOT production in English and Arabic bilingual and monolingual speakers  

NASA Astrophysics Data System (ADS)

VOT patterns were investigated in the production of three Lebanese-English bilinguals' aged 5, 7, and 10, six aged-matched monolingual controls from the bilinguals' immediate communities, and the parents of bilinguals and monolinguals. The aim was to examine the extent to which children exposed to two languages acquire separate VOT patterns for each language and to determine the factors that affect such acquisition. Results showed that VOT patterns for each bilingual child differed significantly across the two languages. But while the contrast in English resembled a monolingual-like model, that for Arabic exhibited persisting developmental features; explanations were offered in terms of the relationship between input and complexity of voicing lead production. Evidence was used from developmental changes that were noted for two of the bilingual subjects over a period of 18 months. English code-switches produced by the bilinguals during Arabic sessions exhibited different VOT patterns from those produced during English sessions, which underlined the importance of taking the language context into consideration. Finally, results from monolinguals and bilinguals showed that the short lag categories for the two languages were different despite a degree of overlap. Such findings require finer divisions of the three universal VOT categories to account for language-specific patterns.

Khattab, Ghada

2001-05-01

194

Tassel Removal Positively Affects Biomass Production Coupled with Significantly Increasing Stem Digestibility in Switchgrass  

PubMed Central

In this study, tassels of Cave-in-Rock (upland) and Alamo (lowland) were removed at or near tassel emergence to explore its effects on biomass production and quality. Tassel-removed (TR) Cave-in-Rock and Alamo both exhibited a significant (P<0.05) increase in plant heights (not including tassel length), tiller number, and aboveground biomass dry weight (10% and 12%, 30% and 13%, 13% and 18%, respectively by variety) compared to a control (CK) treatment. Notably, total sugar yields of TR Cave-in-Rock and Alamo stems increased significantly (P<0.05 or 0.01) by 19% and 19%, 21% and 14%, 52% and 18%, respectively by variety, compared to those of control switchgrass under 3 treatments by direct enzymatic hydrolysis (DEH), enzymatic hydrolysis after 1% NaOH pretreatment (EHAL) and enzymatic hydrolysis after 1% H2SO4 pretreatment (EHAC). These differences were mainly due to significantly (P<0.05 or 0.01) higher cellulose content, lower cellulose crystallinity indexes (CrI) caused by higher arabinose (Ara) substitution in xylans, and lower S/G ratio in lignin. However, the increases of nitrogen (N) and sulphur (S) concentration negatively affects the combustion quality of switchgrass aboveground biomass. This work provides information for increasing biomass production and quality in switchgrass and also facilitates the inhibition of gene dispersal of switchgrass in China. PMID:25849123

Zhao, Chunqiao; Fan, Xifeng; Hou, Xincun; Zhu, Yi; Yue, Yuesen; Zhang, Shuang; Wu, Juying

2015-01-01

195

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

196

IL-27 affects helper T cell responses via regulation of PGE2 production by macrophages.  

PubMed

IL-27 is a heterodimeric cytokine that regulates both innate and adaptive immunity. The immunosuppressive effect of IL-27 largely depends on induction of IL-10-producing Tr1 cells. To date, however, effects of IL-27 on regulation of immune responses via mediators other than cytokines remain poorly understood. To address this issue, we examined immunoregulatory effects of conditional medium of bone marrow-derived macrophages (BMDMs) from WSX-1 (IL-27R?)-deficient mice and found enhanced IFN-? and IL-17A secretion by CD4(+) T cells as compared with that of control BMDMs. We then found that PGE2 production and COX-2 expression by BMDMs from WSX-1-deficient mice was increased compared to control macrophages in response to LPS. The enhanced production of IFN-? and IL-17A was abolished by EP2 and EP4 antagonists, demonstrating PGE2 was responsible for enhanced cytokine production. Murine WSX-1-expressing Raw264.7 cells (mWSX-1-Raw264.7) showed phosphorylation of both STAT1 and STAT3 in response to IL-27 and produced less amounts of PGE2 and COX-2 compared to parental RAW264.7 cells. STAT1 knockdown in parental RAW264.7 cells and STAT1-deficiency in BMDMs showed higher COX-2 expression than their respective control cells. Collectively, our result indicated that IL-27/WSX-1 regulated PGE2 secretion via STAT1-COX-2 pathway in macrophages and affected helper T cell response in a PGE2-mediated fashion. PMID:25088998

Sato, Yayoi; Hara, Hiromitsu; Okuno, Toshiaki; Ozaki, Naoko; Suzuki, Shinobu; Yokomizo, Takehiko; Kaisho, Tsuneyasu; Yoshida, Hiroki

2014-08-22

197

Torque Ripple Reduction in BLDC Torque Motor With Nonideal Back EMF  

Microsoft Academic Search

In order to improve the speed precision and stabilization of the gimbal servo system of double gimbal magnetically suspended control moment gyro, a comprehensive analysis of the reason of electromagnetic torque ripples of brushless direct current motor with nonideal back electromotive force (EMF) drives in the conduction and commutation regions is presented. A novel automatic control method of torque is

Jiancheng Fang; Haitao Li; Bangcheng Han

2012-01-01

198

A method to accurately estimate the muscular torques of human wearing exoskeletons by torque sensors.  

PubMed

In exoskeletal robots, the quantification of the user's muscular effort is important to recognize the user's motion intentions and evaluate motor abilities. In this paper, we attempt to estimate users' muscular efforts accurately using joint torque sensor which contains the measurements of dynamic effect of human body such as the inertial, Coriolis, and gravitational torques as well as torque by active muscular effort. It is important to extract the dynamic effects of the user's limb accurately from the measured torque. The user's limb dynamics are formulated and a convenient method of identifying user-specific parameters is suggested for estimating the user's muscular torque in robotic exoskeletons. Experiments were carried out on a wheelchair-integrated lower limb exoskeleton, EXOwheel, which was equipped with torque sensors in the hip and knee joints. The proposed methods were evaluated by 10 healthy participants during body weight-supported gait training. The experimental results show that the torque sensors are to estimate the muscular torque accurately in cases of relaxed and activated muscle conditions. PMID:25860074

Hwang, Beomsoo; Jeon, Doyoung

2015-01-01

199

Comparison of the MODIS Active Fire Product and Burned Area Product in Detecting Fire Affected Pixels in the Ecosystems of Belize 2003 - 2009   

E-print Network

The MODIS Active Fire Product (AFP) and the Burned Area Product (BAP) were used to analyze the spatial and temporal distribution of fire affected pixels in the ecosystems of Belize from 2003-2009. There was an overall trend of decreasing fire...

van, Warmerdam

2010-11-24

200

Prevailing Torque Locking Feature Wear-out  

NASA Astrophysics Data System (ADS)

This thesis provides much needed representative sample data for reuse life of fully seated and torqued locknuts. Most national requirements for prevailing torque locking fasteners only specify unseated reuse life. This could create a potentially dangerous situation if unseated is misinterpreted for seated. This thesis provides comparative data for seated verses unseated configuration. Six aerospace, 3 all-metal and 3 nylon insert, and one non-aerospace locknuts were tested at preloads levels of unseated, 66%, 75%, and 85% of yield of bolt. The locknuts tested are MS21043-4, NAS1291-4, NAS1805-4, MS17825-4, MS21044D4, NAS1021N4, and Grade 8. A fixture was created in order to allow for the simultaneous data collection of the applied preload and torque, along with the removal of preload without loosening the locknut. The results from testing indicate the number of reuse cycles is greater for nylon locknuts than the all-metal locknuts. Large losses, on the order of 20-50%, in prevailing torque occur between the first and second cycle of each locknut under all preloads. Tightening Torque required to achieve a certain preload was found to increase with reuse. Application of lubrication to nylon locknuts had a significant effect, reducing the reuse life and prevailing torque performance. The testing indicated the effect of preload reduced the number of reuse cycles to failure, failure occurs when the prevailing torque is measured outside the range of 3.5 to 30 in-lb. All locknuts survived unseated and 66% Y preload testing, except MS21043 which lasted about 14.5 reuse cycles at 66% Y and NAS1805 which survived 8 reuse cycles for unseated and 12.67 reuse cycles at 66% Y. NAS1805's loss of reuse life is due to hardness and material compatibility issues. The scatter of the torque measurements was low for the first three to five cycles, then as the coatings and lubrications are worn the scatter increases. The data collected from testing agrees with the torque friction equation.

Zimandy, Adam J. C.

201

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

202

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

203

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

204

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

205

Model Predictive Control of Velocity and Torque Split in a Parallel Hybrid Vehicle  

Microsoft Academic Search

Fuel economy of parallel hybrid electric vehicles is affected by both the torque split ratio and the vehicle velocity. To optimally schedule both variables, information about the surrounding traffic is necessary, but may be made available through telemetry. Consequently, in this paper, a nonlinear model predictive control algorithm is proposed for the vehicle control system to maximise fuel economy while

Tae Soo Kim; Chris Manzie; Rahul Sharma

2009-01-01

206

A robust digital position control of brushless DC motor with dead beat load torque observer  

Microsoft Academic Search

A method for the robust position control of brushless DC (BLDC) motors is presented. The linear quadratic controller plus load torque observer is used to obtain an approximately linearized robust BLDC motor system for an AC servo, using the field-orientation method. The gains are obtained systematically from a discrete state space analysis. The robustness is obtained without affecting the overall

Jong Sun KO; Jung Hoon Lee; Se Kyo Chung; Myung Joong Youn

1993-01-01

207

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

208

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

209

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

210

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

211

Torque for an Inertial Piezoelectric Rotary Motor  

PubMed Central

For a novel inertial piezoelectric rotary motor, the equation of the strain energy in the piezoceramic bimorph and the equations of the strain energy and the kinetic energy in the rotor are given. Based on them, the dynamic equation of the motor is obtained. Using these equations, the inertial driving torque of the motor is investigated. The results show that the impulsive driving torque changes with changing peak voltage of the excitation signal, the piezoelectric stress constant, the thickness of the piezoceramic bimorph, and the rotor radius obviously. Tests about the motor torque are completed which verifies the theory analysis here in. The results can be used to design the operating performance of the motor. PMID:24470794

Xing, Jichun

2013-01-01

212

Helicopter Anti-Torque System Using Strakes  

NASA Technical Reports Server (NTRS)

A helicopter is disclosed with a system for controlling main-rotor torque which reduces the power and size requirements of conventional anti-torque means. The torque countering forces are generated by disrupting the main rotor downwash flowing around the fuselage. The downwash flow is separated from the fuselage surface by a strake positioned at a specified location on the fuselage. This location is determined by the particular helicopter wash pattern and fuselage configuration, generally being located between 20 deg before top dead center (TDC) and 80 deg from TDC on the fuselage side to which the main rotor blade approaches during rotation. The strake extends along the fuselage from the cabin section to the aft end and can be continuous or separated for aerodynamic surfaces such as a horizontal stabilizer.

Kelley, H. L.; Wilson, J. C.; Phelps, A. E. (inventors)

1984-01-01

213

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

214

Assessment of Cultivation Factors that Affect Biomass and Geraniol Production in Transgenic Tobacco Cell Suspension Cultures  

PubMed Central

A large-scale statistical experimental design was used to determine essential cultivation parameters that affect biomass accumulation and geraniol production in transgenic tobacco (Nicotiana tabacum cv. Samsun NN) cell suspension cultures. The carbohydrate source played a major role in determining the geraniol yield and factors such as filling volume, inoculum size and light were less important. Sucrose, filling volume and inoculum size had a positive effect on geraniol yield by boosting growth of plant cell cultures whereas illumination of the cultures stimulated the geraniol biosynthesis. We also found that the carbohydrates sucrose and mannitol showed polarizing effects on biomass and geraniol accumulation. Factors such as shaking frequency, the presence of conditioned medium and solubilizers had minor influence on both plant cell growth and geraniol content. When cells were cultivated under the screened conditions for all the investigated factors, the cultures produced ?5.2 mg/l geraniol after 12 days of cultivation in shaking flasks which is comparable to the yield obtained in microbial expression systems. Our data suggest that industrial experimental designs based on orthogonal arrays are suitable for the selection of initial cultivation parameters prior to the essential medium optimization steps. Such designs are particularly beneficial in the early optimization steps when many factors must be screened, increasing the statistical power of the experiments without increasing the demand on time and resources. PMID:25117009

Vasilev, Nikolay; Schmitz, Christian; Grömping, Ulrike; Fischer, Rainer; Schillberg, Stefan

2014-01-01

215

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

216

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

217

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

218

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

219

Reduced elbow extension torque during vibrations.  

PubMed

Impact sports and vibration platforms trigger vibrations within soft tissues and the skeleton. Although the long-term effects of vibrations on the body have been studied extensively, the acute effects of vibrations are little understood. This study determined the influence of acute vibrations at different frequencies and elbow angles on maximal isometric elbow extension torque and muscle activity. Vibrations were generated by a pneumatic vibrator attached to the lever of a dynamometer, and were applied on the forearm of 15 healthy female subjects. The subjects were instructed to push maximally against the lever at three different elbow angles, while extension torque and muscle activity were quantified and compared between vibration and non-vibration (control) conditions. A change in vibration frequency had no significant effects on torque and muscle activity although vibrations in general decreased the maximal extension torque relative to the control by 1.8% (±5.7%, p>0.05), 7.4% (±7.9%, p<0.01), and 5.0% (±8.2%, p<0.01) at elbow angles of 60°, 90°, and 120°, respectively. Electromyographic activity increased significantly between ?30% and 40% in both triceps and biceps with vibrations. It is speculated that a similar increase in muscle activity between agonist and antagonist, in combination with an unequal increase in muscle moment arms about the elbow joint, limit the maximal extension torque during exposure to vibrations. This study showed that maximal extension torque decreased during vibration exposure while muscle activity increased and suggests that vibrations may be counterproductive during activities requiring maximal strength but potentially beneficial for strength training. PMID:22771229

Friesenbichler, Bernd; Coza, Aurel; Nigg, Benno M

2012-08-31

220

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

221

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

222

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

223

New Simple Torque-Sensorless Torque Control for Quasi-Perfect Compensation of 6th Harmonic Torque Ripple Due to Nonsinusoidal Distribution of Back EMF of PMSM  

NASA Astrophysics Data System (ADS)

This paper proposes a new torque-sensorless torque control method for permanent-magnet synchronous motors (PMSMs). The proposed method can almost perfectly compensate the 6th harmonic torque ripple that is caused by the nonsinusoidal distributions of the back EMF and rotor magnetic flux of PMSMs. The torque control system is, in principle, constructed on the basis of the vector control, but has two new dedicated speed-varying devices—a harmonic torque observer and current controller. The speed-varying harmonic torque observer can estimate the harmonic component over a wide speed range, even in the case where the produced torque is constant, and generate a suitable compensating signal. The speed-varying current controller shows stable control performance over a wide speed range, it can fully track the compensated current command containing the dc and 6th harmonic components. The effectiveness of the proposed method is examined and verified through extensive numerical experiments.

Shinnaka, Shinji; Kishida, Hideo

224

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

PubMed Central

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 of eicosapentaenoic acid [EPA] and 1.0 g of docosahexaenoic acid [DHA]) or placebo oil (5.0 g of corn/soy mixture). A total of 116 subjects (68% female, 20–59 years old) of African American ancestry enrolled, and 98 subjects completed the study. Neither ALOX5 protein nor arachidonic acid-derived LTB4, LTD4, and LTE4 varied by genotype, but 5-hydroxyeicosatetraenoate (5-HETE), 6-trans-LTB4, 5-oxo-ETE, 15-HETE, and 5,15-diHETE levels were higher in subjects homozygous for the ALOX5 promoter allele containing five Sp1 element tandem repeats (“55” genotype) than in subjects with one deletion (d) (three or four repeats) and one common (“d5” genotype) allele or with two deletion (“dd”) alleles. The EPA-derived metabolites 5-HEPE and 15-HEPE and the DHA-derived metabolite 17-HDoHE had similar associations with genotype and increased with supplementation; 5-HEPE and 15-HEPE increased, and 5-oxo-ETE decreased to a greater degree in the 55 than in the other genotypes. This differential eicosanoid response is consistent with the previously observed interaction of these variants with dietary intake of omega-3 fatty acids in predicting cardiovascular disease risk. PMID:21296957

Stephensen, Charles B.; Armstrong, Patrice; Newman, John W.; Pedersen, Theresa L.; Legault, Jillian; Schuster, Gertrud U.; Kelley, Darshan; Vikman, Susanna; Hartiala, Jaana; Nassir, Rami; Seldin, Michael F.; Allayee, Hooman

2011-01-01

225

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

226

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

227

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

228

Robust torque optimization for BLDC spindle motors  

Microsoft Academic Search

A robust design for torque optimization of brushless DC spindle motors applied in a hard disk drive, using the Taguchi method, is described and illustrated in this paper. The optimal design process takes into consideration noises that arise in the manufacturing process, such as manufacturing tolerances for the stator tooth shape and variation of the rotor magnet magnetization distribution due

Teck-Seng Low; Shixin Chen; Xianke Gao

2001-01-01

229

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

Michael Horton

2009-05-30

230

Permanent magnet torque\\/force transfer apparatus  

Microsoft Academic Search

There is presented a torque\\/force transfer apparatus including an annular ring having therein permanent first magnets side by side about the interior of the ring. The first magnets are arranged so as to alternate in polar orientation to present an inside circumference of alternating north and south magnetic poles. The apparatus further comprises a cylindrical central member having therein permanent

Chahee P. Cho; Ralph A. Bidingfield

1994-01-01

231

Torque Limits for Fasteners in Composites  

NASA Technical Reports Server (NTRS)

The two major classes of laminate joints are bonded and bolted. Often the two classes are combined as bonded-bolted joints. Several characteristics of fiber reinforced composite materials render them more susceptible to joint problems than conventional metals. These characteristics include weakness in in-plane shear, transverse tension/compression, interlaminar shear, and bearing strength relative to the strength and stiffness in the fiber direction. Studies on bolted joints of composite materials have been focused on joining assembly subject to in-plane loads. Modes of failure under these loading conditions are net-tension failure, cleavage tension failure, shear-out failure, bearing failure, etc. Although the studies of torque load can be found in literature, they mainly discussed the effect of the torque load on in-plane strength. Existing methods for calculating torque limit for a mechanical fastener do not consider connecting members. The concern that a composite member could be crushed by a preload inspired the initiation of this study. The purpose is to develop a fundamental knowledge base on how to determine a torque limit when a composite member is taken into account. Two simplified analytical models were used: a stress failure analysis model based on maximum stress criterion, and a strain failure analysis model based on maximum strain criterion.

Zhao, Yi

2002-01-01

232

Force\\/torque sensing applied to industrial robotic deburring  

Microsoft Academic Search

Force\\/torque sensing is very important for several automatic and industrial robotic applications. Basically, if precise control of the forces that arise from contact between tools and parts is required to successfully complete the automatic task, then a force\\/torque sensor is needed along with some force\\/torque control technique. In this paper we focus on force\\/torque sensing aspects applied to industrial robotic

J. Norberto Pires; John Ramming; Stephen Rauch; Ricardo Araújo

2002-01-01

233

Specific gravity — dry matter relationship and reducing sugar changes affected by potato variety, production area and storage  

Microsoft Academic Search

The validity of the specific gravity-dry matter relationship in potato tubers is affected by factors such as variety, area of production and storage conditions. Previous work reported by Woodbury and Weinheimer (10) showed that regression coefficients for percent dry matter on specific gravity increased with storage length. Ross and co-workers (8) reported an increase in percent dry matter for a

William M. Agle; G. W. Woodbury

1968-01-01

234

Variable Isoflavone Contents of Red Clover Products Affect Intestinal Disposition of Biochanin A, Formononetin, Genistein and Daidzein  

PubMed Central

Marketed red clover products use a wide variety of labels and the isoflavone contents from the lable is ambiguous. In the present study, we analyzed the content of various isoflavone products, and determined a) the content and b) how sample matrix of red clover products affects intestinal disposition of main isoflavones within it using the human intestinal Caco-2 cell model. Analysis using high and ultra-performance liquid chromatography indicates that the isoflavone content varied significantly (p<0.05) between the chosen products. Consequently, rates of isoflavone absorption across the Caco-2 cell monolayers varied (p<0.05) greatly. Unexpectedly, permeabilities of biochanin A and formononetin (two key biomarkers) were found to be significantly affected (p<0.05) by the product matrix. As expected, biochanin A was the only isoflavone with noticeable metabolite peaks in both apical and basolateral sides. Interestingly, rates of metabolism and the polarity of the glucuronidated biochanin A excretion were also significantly altered (p<0.05) by product matrix. Studies using breast cancer resistance protein inhibitor dipyridamole showed that both the apical and basolateral excretion of biochanin A glucuronides were significantly (P<0.05) reduced (7.5 and 9.4-fold, respectively) when dipyridamole is present. This provides evidence that BCRP is the main transporter responsible for the apical efflux of isoflavone glucuronides. In conclusion, the isoflavone contents of the marketed red clover products are highly variable, and product matrix significantly affected intestinal disposition of red clover isoflavones by altering their absorption rates, permeabilities, biochanin A glucuronide excretion rates, and the polarity of biochanin A glucuronide excretion. This research provides scientific evidence to support the standardization effort so that consumers can make intelligent product choices. PMID:18370585

Wang, Stephen W.J.; Chen, Yan; Joseph, Tiby; Hu, Ming

2009-01-01

235

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

236

Increasing the High Speed Torque of Bipolar Stepper  

E-print Network

Increasing the High Speed Torque of Bipolar Stepper Motors Introduction To successfully follow at the desired rates, and drive the load torque at the desired speeds. While the size of a bipolar stepper motor rates of the winding currents in a bipolar stepper motor pushes the motor to deliver more torque at high

Peters, Dennis

237

Design and development of a segmented magnet homopolar torque converter  

Microsoft Academic Search

This program is for the research and development of a new mechanical power transmission concept (the segmented magnet homopolar torque converter). The purpose of this device is to convert unidirectional torque of constant speed such as from a steam turbine prime mover into variable speed output torque in either the forward or reverse directions. The concept offers an efficient, lightweight

C. J. Mole; F. G. Arcella; E. Berkey; D. J. Boes; V. B. Doshi; R. A. Feranchak; H. E. Haller III; J. L. Johnson; S. A. Karpathy; A. R. Keeton

1976-01-01

238

Design and development of a segmented magnet homopolar torque converter  

Microsoft Academic Search

The program is for the research and development of a new mechanical power transmission concept: the segmented magnet homopolar torque converter. The purpose of this device is to convert unidirectional torque of constant speed (such as from a steam turbine prime mover) into variable speed output torque in either the forward or reverse directions. The concept offers an efficient, lightweight

C. J. Mole; F. G. Arcella; E. Berkey; D. J. Bodes; V. B. Doshi

1975-01-01

239

Clutch torque formulation and calibration for dry dual clutch transmissions  

Microsoft Academic Search

This paper focuses on the clutch torque formulation and calibration for dry dual clutch transmissions (DCT). The correlation on the theoretical clutch torque and control parameters is established based on constant friction power and clutch actuator kinematics. An algorithm based on powertrain dynamics is proposed for the calculation of clutch torque during vehicle launch and shift operations. This algorithm uses

Yonggang Liu; Datong Qin; Hong Jiang; Charles Liu; Yi Zhang

2011-01-01

240

Torque Calculation and Analysis of Permanent-Magnetic Gears  

Microsoft Academic Search

Permanent-magnetic gears are magneto-mechanical devices that are widely used to replace the ordinary mechanical gears and to transmit torque without any mechanical contact. The transmitted torque is one of the most important properties of magnetic gears. The torque characteristics of radial type permanent magnetic gears are investigated using ANSYS Program. The Maxwell stress tensor technique is used to calculate the

Yang Zhiyi; Zhao Han

241

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

242

February 2004 The production of discourse in four subjects affected with psychosis1  

E-print Network

speeches of three subjects affected with schizophrenia and one affected with paranoïa. We present instance, are vocabulary and syntax really impoverished in patients?) and what exactly accounts 1992) that schizophrenia may be the result of deficits in self-consciousness and self

Paris-Sud XI, Université de

243

Performances improvements and torque ripple minimization for VSI fed induction machine with direct control torque.  

PubMed

This paper describes a torque ripple reduction technique with constant switching frequency for direct torque control (DTC) of an induction motor (IM). This method enables a minimum torque ripple control. In order to obtain a constant switching frequency and hence a torque ripple reduction, we propose a control technique for IM. It consists of controlling directly the electromagnetic torque by using a modulated hysteresis controller. The design methodology is based on space vector modulation (SVM) of electrical machines with digital vector control. MATLAB simulations supported with experimental study are used. The simulation and experimental results of this proposed algorithm show an adequate dynamic to IM; however, the research can be extended to include synchronous motors as well. The implementation of the proposed algorithm is described. It doesn't require any PI controller in the torque control loop. The hardware inverter is controlled digitally using a Texas Instruments TMS320F240 digital signal processor (DSP) with composed C codes for generating the required references. The results obtained from simulation and experiments confirmed the feasibility of the proposed strategy compared to the conventional one. PMID:21193193

Abdelli, R; Rekioua, D; Rekioua, T

2011-04-01

244

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

245

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

246

A control system for maintaining constant braking torque on a disk brake dynamometer  

Microsoft Academic Search

Most manufacturers of composite friction materials do not possess adequate facilities to test their products dynamically. A practical solution is to simulate the braking process in the laboratory mechanically by means of a disc brake dynamometer. The authors describe a control-system design for the dynamometer. The function of the control system is to maintain a constant braking torque for the

G. P. Hancke; R. E. Zietsman

1989-01-01

247

Optimal Design of Motor and Gear for Drives with High Acceleration and Load Torque  

E-print Network

Optimal Design of Motor and Gear for Drives with High Acceleration and Load Torque H. Grotstollen-acceleration product are transmitted unchanged by an ideal gear. At a first step those motors can be selected which offer sufficient rated power and power rate. When designing gears for each of these motors two ranges

Paderborn, Universität

248

A Study of Factors Affecting Consumer Evaluations and Memory of Product Placements in Movies  

Microsoft Academic Search

An important issue for a firm wishing to invest in a product placement is deciding how its product or brand is going to be presented within the movie. Accordingly, the objective of this research study is to examine the impact of objective and subjective characteristics of product placements on consumer evaluations and memory. A sample of 103 movie goers viewed

Alain DAstous; Francis Chartier

2000-01-01

249

A modified direct torque control of IPM synchronous machine drive with constant switching frequency and low ripple in torque  

Microsoft Academic Search

A modified direct torque control (DTC) scheme for interior permanent magnet synchronous machine (IPMSM) is investigated in this paper, which features in very low flux and torque ripple and almost fixed switching frequency. The new scheme provides a variable option for the improvement of DTC controlled IPMSM. Two PI controllers regulate the flux and torque respectively and the stator voltage

A. Daghigh; M. B. B. Sharifian; M. Farasat

2010-01-01

250

A global analysis of fine root production as affected by soil nitrogen and phosphorus.  

PubMed

Fine root production is the largest component of belowground production and plays substantial roles in the biogeochemical cycles of terrestrial ecosystems. The increasing availability of nitrogen (N) and phosphorus (P) due to human activities is expected to increase aboveground net primary production (ANNP), but the response of fine root production to N and P remains unclear. If roots respond to nutrients as ANNP, fine root production is anticipated to increase with increasing soil N and P. Here, by synthesizing data along the nutrient gradient from 410 natural habitats and from 469 N and/or P addition experiments, we showed that fine root production increased in terrestrial ecosystems with an average increase along the natural N gradient of up to 0.5 per cent with increasing soil N. Fine root production also increased with soil P in natural conditions, particularly at P < 300 mg kg(-1). With N, P and combined N + P addition, fine root production increased by a global average of 27, 21 and 40 per cent, respectively. However, its responses differed among ecosystems and soil types. The global average increases in fine root production are lower than those of ANNP, indicating that above- and belowground counterparts are coupled, but production allocation shifts more to aboveground with higher soil nutrients. Our results suggest that the increasing fertilizer use and combined N deposition at present and in the future will stimulate fine root production, together with ANPP, probably providing a significant influence on atmospheric CO(2) emissions. PMID:22764168

Yuan, Z Y; Chen, Han Y H

2012-09-22

251

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

252

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

253

Spin-orbit-torque engineering via oxygen manipulation.  

PubMed

Spin transfer torques allow the electrical manipulation of magnetization at room temperature, which is desirable in spintronic devices such as spin transfer torque memories. When combined with spin-orbit coupling, they give rise to spin-orbit torques, which are a more powerful tool for controlling magnetization and can enrich device functionalities. The engineering of spin-orbit torques, based mostly on the spin Hall effect, is being intensely pursued. Here, we report that the oxidation of spin-orbit-torque devices triggers a new mechanism of spin-orbit torque, which is about two times stronger than that based on the spin Hall effect. We thus introduce a way to engineer spin-orbit torques via oxygen manipulation. Combined with electrical gating of the oxygen level, our findings may also pave the way towards reconfigurable logic devices. PMID:25730601

Qiu, Xuepeng; Narayanapillai, Kulothungasagaran; Wu, Yang; Deorani, Praveen; Yang, Dong-Hyuk; Noh, Woo-Suk; Park, Jae-Hoon; Lee, Kyung-Jin; Lee, Hyun-Woo; Yang, Hyunsoo

2015-05-01

254

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

255

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

256

Sex hormones affect the production of recombinant Factor IX in CHO and HEK-293 cell lines.  

PubMed

Recombinant human Factor IX (rFIX) was cloned in a mammalian expression vector and transfected into CHO and HEK-293. Treatment with 10(-9) M methyl testosterone increased rFIX production by 30-50% in CHO and HEK clones. However, 10(-9) M 17beta-oestradiol increased production of rFIX by ~50% in CHO-F7 clone and decreased production by 48% and 37% in CHO-F8 and HEK-F2-6, respectively. Progesterone treatment inhibited rFIX production in both cell lines. Production of rFIX can thus be increased by sex hormone treatment and therefore used to enhance biotechnological production in mammalian cells. PMID:18581062

Dadehbeigi, Nazanin; Ostad, Seyed Nasser; Faramarzi, Mohammad Ali; Ghahremani, Mohammad Hossein

2008-11-01

257

A Reference Value Calculation Scheme for Torque and Flux and an Anti-Windup Implementation of Torque Controller for Direct Torque Control of Permanent Magnet Synchronous Motor  

NASA Astrophysics Data System (ADS)

This paper discusses a permanent magnet synchronous motor (PMSM) drive system based on direct torque control. First, in this paper we propose a novel torque-limiting and flux-weakening method. Torque limiting method capable of current limiting is based on the power equation instead of the motor model in the rotating d-q frame, which is synchronized to the rotor magnet. In this torque limiting method, the motor parameters need not be determined and this simplifies the limitation calculation. The proposed method incorporates a flux-weakening control that does not require motor parameters other than the armature resistance. These proposed schemes are implemented in a calculator for calculating the reference torque and reference flux. Second, we also propose an anti-windup scheme for torque control based on proportional and integral control. Generally, the controller winds up when the terminal output voltage of the inverter is saturated. The wind-up degrades the torque limiting and torque control performance. In the proposed anti-windup scheme, the gain of the integral element is varied on the basis of the degree of voltage saturation, which is detected by using the estimated flux-linkage. In this paper, the direct-torque-control-based drive system combined with a speed controller is presented, and the proposed system achieves stable operation. The proposed system is validated through experiments.

Inoue, Yukinori; Morimoto, Shigeo; Sanada, Masayuki

258

Quantum transport in Spin Torque Transfer Devices  

NASA Astrophysics Data System (ADS)

We present a simulation of tunneling based Spin Torque Transfer (STT) devices using the Non Equilibrium Greens Function (NEGF) formalism in the ballistic regime. Our method is based on effective mass treatment of the magnetic contacts and tunneling oxide, including the effect of transverse modes in the transverse direction. We show that it is possible to achieve a quantitative agreement with experiments for both the tunneling magneto resistance (TMR) and the amplitude of the switching current with the same set of device parameters [1]. We shall talk about some implications of these results in the context of improving the device performance. We shall also briefly discuss how the nature of the torque may change if there is spin flip scattering. [1] S.Salahuddin, Deepanjan Datta, Prabhakar Srivastava and Supriyo Datta, proceedings of International Electron Devices Meeting (IEDM), 2007.

Salahuddin, Sayeef; Datta, Deepanjan; Srivastava, Prabhakar; Datta, Supriyo

2008-03-01

259

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

260

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

261

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. ...

262

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

263

Distribution and abundance of predators that affect duck production--prairie pothole region  

USGS Publications Warehouse

During 1983-88, the relative abundance of 18 species and species-groups of mammalian and avian predators affecting duck production in the prairie pothole region was determined in 33 widely scattered study areas ranging in size from 23-26 km2. Accounts of each studied species and species-group include habitat and history, population structure and reported densities, and information on distribution and abundance from the present study. Index values of undetected, scarce, uncommon, common, or numerous were used to rate abundance of nearly all species in each study area. Principal survey methods were livetrapping of striped skunks (Mephitis mephitis) and Franklin's ground squirrels (Spermophilus franklinii), systematic searches for carnivore tracks in quarter sections (0.65 km2), daily records of sightings of individual predator species, and systematic searches for occupied nests of tree-nesting avian predators. Abundances of predators in individual areas were studied 1-3 years.The distribution and abundance of predator species throughout the prairie pothole region have undergone continual change since settlement of the region by Europeans in the late 1800's. Predator populations in areas we studied differed markedly from those of pristine times. The changes occurred from habitat alterations, human-inflicted mortality of predators, and interspecific relations among predator species. Indices from surveys of tracks revealed a decline in the abundance of red foxes (Vulpes vulpes) and an albeit less consistent decline in the abundance of raccoons (Procyon lotor) with an increase in the abundance of coyotes (Canis latrans). Records of locations of occupied nests revealed great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) tended to nest 0.5 km apart, and American crows (Corvus brachyrhynchos) tended to avoid nesting 0.5 km of nests of red-tailed hawks. Excluding large gulls, for which no measurements of abundance were obtained, the number of predator species averaged 12.2 (SD = 1.60) per study area; common or numerous predator species averaged 6.0 (SD = 1.54) per study area (minimal because the abundance of weasels [Mustela erminea; M. frenata] in all areas and of minks [Mustela vison] and raptors in some areas was not rated). Major changes in relative abundance of individual predator species studied >1 year were few. Predator species most restricted to the aspen parkland were the Franklin's ground squirrel, black-billed magpie (Pica pica), American crow (Corvus brachyrlus), and red-tailed hawk; species most restricted to the prairie were the badger (Taxidea taxus), Swainson's hawk (Buteo swainsoni), and ferruginous hawk (B. regalis). The coyote, black-billed magpie, and American crow were most numerous in Canada, whereas the red fox, raccoon, mink, ferruginous hawk, and great horned owl were most numerous in the United States. The number of common or numerous egg-eating predator species (excludes large gulls and weasels, which were not rated) averaged 4.6 (SD = 0.90) per study area. The average numbers of common or numerous egg-eating species per study area did not differ among provinces and states, but birds gradually replaced mammals from southeast to northwest across the region. Investigators are urged to assess composition of predator populations and relative abundance of predator species for evaluations of waterfowl recruitment.

Sargeant, A.B.; Greenwood, R.J.; Sovada, M.A.; Shaffer, T.L.

1993-01-01

264

HdaA, a class 2 histone deacetylase of Aspergillus fumigatus, affects germination and secondary metabolite production  

PubMed Central

Histone deacetylases (HDACs) play an important role in regulation of gene expression through histone modifications. Here we show that the Aspergillus fumigatus HDAC HdaA is involved in regulation of secondary metabolite production and is required for normal germination and vegetative growth. Deletion of the hdaA gene increased the production of several secondary metabolites but decreased production of gliotoxin whereas over-expression hdaA increased production of gliotoxin. RT-PCR analysis of 14 non-ribosomal peptide synthases indicated HdaA regulation of up to 9 of them. A mammalian cell toxicity assay indicated increased activity in the over-expression strain. Neither mutant affected virulence of the fungus as measured by macrophage engulfment of conidia or virulence in a neutropenic mouse model. PMID:19563902

Lee, Inhyung; Oh, Jee-Hwan; Shwab, E. Keats; Dagenais, Taylor R. T.; Andes, David; Keller, Nancy P.

2009-01-01

265

Key factors affecting microbial anode potential in a microbial electrolysis cell for H 2 production  

Microsoft Academic Search

In order to optimize operations of microbial electrolysis cell (MEC) for hydrogen production, microbial anode potential (MAP) was analyzed as a function of factors in biofilm anode system, including pH, substrate and applied voltage. The results in “H” shape reactor showed that MAP reflected the information when any factor became limiting for hydrogen production. Commonly, hydrogen generation started around anode

Aijie Wang; Wenzong Liu; Nanqi Ren; Jizhong Zhou; Shaoan Cheng

2010-01-01

266

How can varieties and rain-fed production environments affect malting quality in spring barley?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rain-fed barley production environments can be highly variable across a region and across years. Almost all malting barley production in Washington State is under rain-fed conditions. The industry has noticed that in some cases malt beta-glucan levels and other malting quality parameters have been u...

267

They Raise Them Differently Up North - Different Production Practices in Australian Growing Areas May Affect Mycorrhizae  

Technology Transfer Automated Retrieval System (TEKTRAN)

This report briefly summarizes the results from a survey to determine cultural blueberry practices and production differences used in New South Wales (NSW), Victoria, Tasmania, and Queensland. The purpose of the survey was to collect information on a number of production practices that had been s...

268

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

269

Mould growth and mycotoxin production as affected by Equisetum arvense and Stevia rebaudiana extracts  

Microsoft Academic Search

Cereals are very important for human and animal diet. However, agricultural products can be contaminated by moulds and their mycotoxins. On the other hand, natural plant products with antimicrobial properties could be a possibility to control mycotoxigenic fungi in foods and feeds. In this study, Equisetum arvense and Stevia rebaudiana extracts were tested for their efficacy against a range of

Daiana Garcia; Esther Garcia-Cela; Antonio J. Ramos; Vicente Sanchis; Sonia Marín

2011-01-01

270

Environmental, management and genetic factors affecting semen production in French Montbéliard bulls  

Microsoft Academic Search

The objectives of this study were to evaluate the importance of physiological, environmental, management and genetic factors on semen production (semen volume, sperm concentration and number of sperm per ejaculate) and to estimate the correlation between sexual performance of bulls at early age in the test station and at later ages in AI units. Semen production data from three AI

M Mathevon; J. C. M Dekkers; M. M Buhr

1998-01-01

271

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

272

Spin Torque in Magnetic Tunnel Junctions  

NASA Astrophysics Data System (ADS)

The effect of current-induced switching in the orientation of magnetic moments has attracted much attention both experimentally[1] and theoretically in the past several years due to its potential application to spin electronics. The origin of the current-induced switching is the spin torque due to the local exchange interactions between the conduction electrons and the magnetic moments. Using a simple tight-binding Hamiltonian[2] for the magnetic metal-insulator-magnetic metal tunneling junction and the Keldysh formalism for the non-equilibrium Green functions, we have calculated the spin torque and the tunneling current in non-collinear magnetic junctions. We have studied the effect of the bias voltage, the thickness of the barrier and the angle between the magnetizations of the ferromagnetic electrodes on the spin torque and the tunneling current. *E. Myers, D. Ralph, J. Katine, R. Louie, R. Buhrman, Science 285, 867 (1999). *C. Caroli, R. Combescot, P. Nozieres, D. Saint-James, J. Phys. C: Solid St. Phys., 4, 916 (1971). *Supported through the NSF grant No. DMR-0097187

Kalitsov, Alan; Butler, William

2005-03-01

273

Magnetorheological torque transmission devices with permanent magnets  

NASA Astrophysics Data System (ADS)

A novel type of magnetorheological (MR) clutch whose magnetic circuit contains a combination of a permanent magnet and an electromagnet is described. Without the support of the electromagnet, the permanent magnet generates a magnetic field in the MR fluid shear gap which enables the MR clutch to transmit a torque without the supply of any electric energy. Hence, the operational states of this clutch are reversed with respect to the common MR clutches equipped with an electromagnet only. Three different MR clutches with hybrid magnetic circuits containing permanent magnet and electromagnet were designed, manufactured and tested. The three clutches differ in their number of mechanical parts which can rotate with respect to each other as well as in their size and weight and in their maximum transmittable torque. The largest MR clutch is capable to transmit torques up to nearly 800 Nm. The designs of the three novel MR clutches and the results of the mechanical tests upon variation of the coil current are presented in this paper.

Böse, H.; Gerlach, T.; Ehrlich, J.

2013-02-01

274

Nature and measurements of torque ripple of permanent-magnet adjustable-speed motors  

SciTech Connect

Torque ripple of permanent-magnet motors can be classified into four types depending on the nature of their origin. The four types are pulsating torque, fluctuating torque, reluctance cogging torque, and inertia and mechanical system torque. Pulsating torques are inherently produced by the trapezoidal back-emf`s and trapezoidal currents used in certain permanent-magnet adjustable-speed motors. The torque ripples caused by pulsating torques may be reduced by purposely produced fluctuating counter torques. Air-gap torque measurements are conducted on a sample motor. Experimental results agree with theoretical expectations.

Hsu, J.S.; Scoggins, B.P.; Scudiere, M.B.; Marlino, L.D.; Adams, D.J.; Pillay, P.

1995-08-01

275

How can farming intensification affect the environmental impact of milk production?  

PubMed

The intensification process of the livestock sector has been characterized in recent decades by increasing output of product per hectare, increasing stocking rate, including more concentrated feed in the diet, and improving the genetic merit of the breeds. In dairy farming, the effects of intensification on the environmental impact of milk production are not completely clarified. The aim of the current study was to assess the environmental impacts of dairy production by a life cycle approach and to identify relations between farming intensity and environmental performances expressed on milk and land units. A group of 28 dairy farms located in northern Italy was involved in the study; data collected during personal interviews of farmers were analyzed to estimate emissions (global warming potential, acidification, and eutrophication potentials) and nonrenewable source consumption (energy and land use). The environmental impacts of milk production obtained from the life cycle assessment were similar to those of other recent studies and showed high variability among the farms. From a cluster analysis, 3 groups of farms were identified, characterized by different levels of production intensity. Clusters of farms showed similar environmental performances on product basis, despite important differences in terms of intensification level, management, and structural characteristics. Our study pointed out that, from a product perspective, the most environmentally friendly way to produce milk is not clearly identifiable. However, the principal component analysis showed that some characteristics related to farming intensification, such as milk production per cow, dairy efficiency, and stocking density, were negatively related to the impacts per kilogram of product, suggesting a role of these factors in the mitigation strategy of environmental burden of milk production on a global scale. Considering the environmental burden on a local perspective, the impacts per hectare were positively associated with the intensification level. PMID:24792806

Bava, L; Sandrucci, A; Zucali, M; Guerci, M; Tamburini, A

2014-07-01

276

The Spin Torque Lego - from spin torque nano-devices to advanced computing architectures  

NASA Astrophysics Data System (ADS)

Spin transfer torque (STT), predicted in 1996 [1], and first observed around 2000, brought spintronic devices to the realm of active elements. A whole class of new devices, based on the combined effects of STT for writing and Giant Magneto-Resistance or Tunnel Magneto-Resistance for reading has emerged. The second generation of MRAMs, based on spin torque writing : the STT-RAM, is under industrial development and should be out on the market in three years. But spin torque devices are not limited to binary memories. We will rapidly present how the spin torque effect also allows to implement non-linear nano-oscillators, spin-wave emitters, controlled stochastic devices and microwave nano-detectors. What is extremely interesting is that all these functionalities can be obtained using the same materials, the exact same stack, simply by changing the device geometry and its bias conditions. So these different devices can be seen as Lego bricks, each brick with its own functionality. During this talk, I will show how spin torque can be engineered to build new bricks, such as the Spintronic Memristor, an artificial magnetic nano-synapse. I will then give hints on how to assemble these bricks in order to build novel types of computing architectures, with a special focus on neuromorphic circuits. [4pt] [1] J. C. Slonczewski, J. Magn. Magn. Mater. 159, 1 (1996) & L. Berger, Phys. Rev. B 54, 9353 (1996)

Grollier, Julie

2013-03-01

277

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

Code of Federal Regulations, 2010 CFR

...affected source. For each HCl process vent and each HCl storage...and the number of traverse points a. Method 1 or 1A in appendix A to 40...Cl2 concentration from HCl process vents a. Method 26A in appendix A to 40...

2010-07-01

278

The affective and cognitive components of country image : Perceptions of American products in Kuwait  

Microsoft Academic Search

Purpose – The purpose of this paper is to utilize the BIAS map from the social psychology literature to operationalize and simultaneously examine the effects of the affective and cognitive components of country image. Design\\/methodology\\/approach – The researchers collected survey data using a snowball sample of undergraduates from a prominent university in Kuwait. The final sample consisted of 410 Kuwaitis

Amro A. Maher; Larry L. Carter

2011-01-01

279

Gamma hydroxybutyric acid (GHB) concentrations in humans and factors affecting endogenous production  

Microsoft Academic Search

The endogenous nature of the drug of abuse gamma hydroxybutyric acid (GHB) has caused various interpretative problems for toxicologists. In order to obtain data for the presence of endogenous GHB in humans and to investigate any factors that may affect this, a volunteer study was undertaken. The GHB concentrations in 119 urine specimens from GHB-free subjects and 25 urine specimens

Simon P Elliott

2003-01-01

280

How body mass and lifestyle affect juvenile biomass production in placental mammals  

PubMed Central

In mammals, the mass-specific rate of biomass production during gestation and lactation, here called maternal productivity, has been shown to vary with body size and lifestyle. Metabolic theory predicts that post-weaning growth of offspring, here termed juvenile productivity, should be higher than maternal productivity, and juveniles of smaller species should be more productive than those of larger species. Furthermore because juveniles generally have similar lifestyles to their mothers, across species juvenile and maternal productivities should be correlated. We evaluated these predictions with data from 270 species of placental mammals in 14 taxonomic/lifestyle groups. All three predictions were supported. Lagomorphs, perissodactyls and artiodactyls were very productive both as juveniles and as mothers as expected from the abundance and reliability of their foods. Primates and bats were unproductive as juveniles and as mothers, as expected as an indirect consequence of their low predation risk and consequent low mortality. Our results point the way to a mechanistic explanation for the suite of correlated life-history traits that has been called the slow–fast continuum. PMID:24403339

Sibly, Richard M.; Grady, John M.; Venditti, Chris; Brown, James H.

2014-01-01

281

Factors affecting the work productivity of Oraon agricultural laborers of Jalpaiguri district, West Bengal.  

PubMed

In developing countries like India, where the incidence of protein-calorie malnutrition is high and mechanization is at a minimum, human labor provides much of the power for physical activity. This study presents anthropometric measurements, somatotypes, food intakes, energy expenditures, and work outputs of Oraon agricultural laborers of the Jalpaiguri district, West Bengal, in an attempt to identify the factors that predict high work productivity. Specifically, this study investigates 1) the relationship between morphological variation (anthropometric measurements and somatotype) and work productivity, 2) the nature and extent of the relationship between nutritional status and work productivity, and 3) the best predictor variables of work output. Classification of groups on the basis of median values of work output show that in the aggregate, the high productive groups are significantly younger than low-productive groups in both sexes. Before age-adjustment, the high productive groups show higher mean values of a few body dimensions, though these differ by sex, and both males and females exhibit a normal range of blood pressure and pulse rate values. Mean values of grip strength and back strength are higher in high-output men and women. Mean values of both food intake and energy expenditure are also higher among men in high-output groups, with only food intake higher in high-output women. However, after eliminating the effects of age, the differences between low-productive groups and high-productive groups in most of the variables are not significant. Productivity predictors in males consist of age, food intake and chest girth (inhalation). Females, on the other hand, show age and grip strength (left) as work output predictors. PMID:11842402

Roy, Subrata K

2002-03-01

282

Sex hormones affect the production of recombinant Factor IX in CHO and HEK293 cell lines  

Microsoft Academic Search

Recombinant human Factor IX (rFIX) was cloned in a mammalian expression vector and transfected into CHO and HEK-293. Treatment\\u000a with 10?9 M methyl testosterone increased rFIX production by 30–50% in CHO and HEK clones. However, 10?9 M 17?-oestradiol increased production of rFIX by ~50% in CHO-F7 clone and decreased production by 48% and 37% in CHO-F8 and\\u000a HEK-F2-6, respectively. Progesterone treatment inhibited

Nazanin Dadehbeigi; Seyed Nasser Ostad; Mohammad Ali Faramarzi; Mohammad Hossein Ghahremani

2008-01-01

283

Factors Affecting Carbohydrate Production and Loss in Salt Marsh Sediments of Galveston Bay  

E-print Network

Benthic microalgae (BMA) living within the surface sediment of salt marshes are highly productive organisms that provide a significant proportion of organic carbon inputs into estuarine systems. BMA secrete extracellular carbohydrates in the form...

Wilson, Carolyn E.

2010-10-12

284

Factors affecting binder properties between production and construction and their impact on quality assurance programs  

E-print Network

. In Texas, QA testing is done immediately after binder production, regardless of the fact that the material undergoes several storage and transfer processes before it reaches the construction site or hot mix asphalt (HMA) plant. Storage at elevated...

Arambula Mercado, Edith

2002-01-01

285

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...

286

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

287

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

288

Modelling grain alignment by radiative torques and hydrogen formation torques in reflection nebula  

NASA Astrophysics Data System (ADS)

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 modelling of grain alignment by RATs for the IC 63 reflection nebula illuminated both by a nearby ? 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?/AV) with visual extinction AV across the cloud. Our results show that the variation of pV/AV versus AV from the dayside of IC 63 to its centre can be represented by a power law (p_V/A_V? A_V^{? }) with different slopes depending on AV. We find a shallow slope ? ˜ -0.1 for AV < 3 and a very steep slope ? ˜ -2 for AV > 4. We then consider the effects of additional torques due to H2 formation and model grain alignment by joint action of RATs and H2 torques. We find that pV/AV tends to increase with an increasing magnitude of H2 torques. In particular, the theoretical predictions obtained for pV/AV and peak wavelength ?max in this case show an improved agreement with the observational data. Our results reinforce the predictive power of the RAT alignment mechanism in a broad range of environmental conditions and show the effect of pinwheel torques in environments with efficient H2 formation. Physical parameters involved in H2 formation may be constrained using detailed modelling of grain alignment combined with observational data. In addition, we discuss implications of our modelling for interpreting latest observational data by Planck and other ground-based instruments.

Hoang, Thiem; Lazarian, A.; Andersson, B.-G.

2015-04-01

289

Factors affecting the polycyclic aromatic hydrocarbon content of cereals, fats and other food products  

Microsoft Academic Search

Factors affecting polycyclic aromatic hydrocarbon (PAH) concentrations in oils and fats, cereals and related foodstuffs have been investigated. Levels of PAHs were low in retail fish and animal?derived oils and fats, such as butter, where the mean benzo(a)pyrene concentration was 0.06 ?g\\/kg. Higher and more variable amounts were present in retail vegetable oils for which the mean level of benzo(a)pyrene

M. J. Dennis; R. C. Massey; G. Cripps; I. Venn; N. Howarth; G. Lee

1991-01-01

290

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

...2010-07-01 true Minimum Data for Continuous Compliance...Tire Production Affected Sources 9 Table 9 to Subpart...of Part 63—Minimum Data for Continuous Compliance...Tire Production Affected Sources As stated in § 63...must maintain minimum data to show continuous...

2010-07-01

291

Electromagnetic torques in the core and resonant excitation of decadal polar motion  

NASA Astrophysics Data System (ADS)

Motion of the rotation axis of the Earth contains decadal variations with amplitudes on the order of 10 mas. The origin of these decadal polar motions is unknown. A class of rotational normal modes of the core-mantle system termed torsional oscillations are known to affect the length of day (LOD) at decadal periods and have also been suggested as a possible excitation source for the observed decadal polar motion. Torsional oscillations involve relative motion between the outer core and the surrounding solid bodies, producing electromagnetic torques at the inner-core boundary (ICB) and core-mantle boundary (CMB). It has been proposed that the ICB torque can explain the excitation of the approximately 30-yr-period polar motion termed the Markowitz wobble. This paper uses the results of a torsional oscillation model to calculate the torques generated at Markowitz and other decadal periods and finds, in contrast to previous results, that electromagnetic torques at the ICB can not explain the observed polar motion.

Mound, Jon E.

2005-02-01

292

Distinct promoters affect pyrroloquinoline quinone production in recombinant Escherichia coli and Klebsiella pneumoniae.  

PubMed

Pyrroloquinoline quinone (PQQ) is a versatile quinone cofactor participating in numerous biological processes. Klebsiella pneumoniae can naturally synthesize PQQ for harboring intact PQQ synthesis genes. Previous metabolic engineering of K. pneumoniae failed to overproduce PQQ due to the employment of strong promoter in expression vector. Here we report that a moderate rather than strong promoter is efficient for PQQ production. To screen an appropriate promoter, a total of four distinct promoters-lac promoter, pk promoter of glycerol dehydratase gene (dhaB1), promoter of kanamycin resistance gene, and T7 promoter (as the control)-were individually used for overexpressing the endogenous PQQ genes in K. pneumoniae along with heterologous expression in Escherichia coli. We found that all recombinant K. pneumoniae strains produced more PQQ than recombinant E. coli strains that carried corresponding vectors, indicating that K. pneumoniae is superior to E. coli for the production of PQQ. Particularly, the recombinant K. pneumoniae recruiting the promoter of kanamycin resistance gene produced the highest PQQ (1,700 nmol), revealing that a moderate rather than strong promoter is efficient for PQQ production. Furthermore, PQQ production was roughly proportional to glucose concentration increasing from 0.5 to 1.5 g/L, implying the synergism between PQQ biosynthesis and glucose utilization. This study not only provides a feasible strategy for production of PQQ in K. pneumoniae, but also reveals the exquisite synchronization among PQQ biosynthesis, glucose metabolism, and cell proliferation. PMID:24858816

Sun, Jiguo; Han, Zengye; Ge, Xizhen; Tian, Pingfang

2014-10-01

293

An experimental study on fermentative H? production from food waste as affected by pH.  

PubMed

Batch dark fermentation experiments were performed on food waste and mixtures of food waste and wastewater activated sludge to evaluate the influence of pH on biological H2 production and compare the process performance with and without inoculum addition. The effect of a preliminary thermal shock treatment of the inoculum was also investigated as a means to harvest the hydrogenogenic biomass. The best performance in terms of both H2 generation potential and process kinetics was observed at pH=6.5 under all experimental conditions (no inoculum, and untreated or thermally treated inoculum added). H2 production from food waste was found to be feasible even without inoculum addition, although thermal pre-treatment of the inoculum notably increased the maximum production and reduced the lag phase duration. The analysis of the fermentation products indicated that the biological hydrogen production could be mainly ascribed to a mixed acetate/butyrate-type fermentation. However, the presence of additional metabolites in the digestate, including propionate and ethanol, also indicated that other metabolic pathways were active during the process, reducing substrate conversion into hydrogen. The plateau in H2 generation was found to mirror the condition at which soluble carbohydrates were depleted. Beyond this condition, homoacetogenesis probably started to play a role in the degradation process. PMID:24833177

Cappai, G; De Gioannis, G; Friargiu, M; Massi, E; Muntoni, A; Polettini, A; Pomi, R; Spiga, D

2014-08-01

294

Temperature Dependence of Scott Thermomagnetic Torque in N2, Ch4, and Hd  

E-print Network

and McCourt. We report in this paper new measurements on the temperature dependence of the Scott thermo- magnetic torque in the three gases nitrogen, meth- ane, and deuterium hydride. Temperature changes affect the collision frequency... and the occupation number of the molecule's rotational energy levels. Nitrogen was studied and is reported here because extensive measurements at room temperature and initial temperature-dependence measurements' have been made on this gas. Deuterium hydride has...

Adair, Thomas W.

1972-01-01

295

Friction- and mountain-torque estimates from global atmospheric data  

NASA Technical Reports Server (NTRS)

Seasonal, zonal surface torques between the atmosphere and the earth are estimated and compared, using data from a number of independent sources. The mountain torque is computed both from surface pressure data and from isobaric height data. The friction torque is estimated from the oceanic stress data of Hellerman and Rosenstein. Results for the total torque are inferred from atmospheric angular momentum data. Finally, the globally integrated total torque is compared with astronomical observations of the earth's rotation rate. These comparisons help us to assess the quality of the different results. Zonal torques are also computed using results from a GFDL general circulation model of the atmosphere. A comparison with the corresponding results inferred from real data is presented and interpreted in terms of model accuracy.

Wahr, J. M.; Oort, A. H.

1984-01-01

296

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

297

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

298

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

299

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

300

Heat and moisture production of growing-finishing gilts as affected by environmental temperature  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heat and moisture production (HMP) values are used to size ventilation fans in animal housing. The HMP values that are currently published in the ASABE (American Society of Agricultural and Biological Engineers) standards were from data collected in the early 1950. This study is one of a series of...

301

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

302

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

Microsoft Academic Search

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

Alberto Jiménez; María A Santos; José L Revuelta

2008-01-01

303

HYDROLOGIC CONDITIONS AFFECTING THE TROPOSPHERIC FLUX OF VINCLOZOLIN AND ITS DEGRADATION PRODUCTS  

EPA Science Inventory

A laboratory chamber was used to determine hydrologic conditions that lead to the tropospheric flux of a suspected anti-androgenic dicarboximide fungicide, vinclozolin (3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-oxzoli-dine-2,4-dione) and three degradation products from sterilized...

304

INDIRECT IMPACTS OF CLIMATE CHANGE THAT AFFECT AGRICULTURAL PRODUCTION: SOIL EROSION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land degradation poses an increasing threat to agricultural production. Under natural conditions, topsoil in the aggregate is renewed at a rate approximately equal to the rate at which degradation occurs. However, much agricultural land degrades at faster than "tolerable rates". Pimental et al. (1...

305

Restoration of eroded landscapes to reduce variability in soil properties affecting productivity  

Technology Transfer Automated Retrieval System (TEKTRAN)

In hilly landscapes, tillage and water erosion combine to induce large variability in soil productivity at the field scale. Approaches to manage this variability have been proposed, including restoring the landscape by physically moving soil from areas of net deposition to areas of net soil loss. We...

306

Restoring a landscape to reduce erosion-induced variability in soil properties affecting productivity  

Technology Transfer Automated Retrieval System (TEKTRAN)

In hilly landscapes, tillage and water erosion can combine to induce large variability in soil productivity at the field scale. Approaches to manage this variability have been proposed, including restoring the landscape by physically moving soil from areas of net deposition to areas of net soil loss...

307

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

308

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...

309

Factors affecting the fermentative production of a lysozyme-binding antibody fragment in Escherichia coli.  

PubMed

Fed-batch fermentation for production of a single-chain Fv antibody fragment (scFv) expressed as a recombinant periplastic protein from Escherichia coli was investigated. A high cell density of 50 g dry cell weight per liter was routinely achieved in a 14-L vessel by controlled exponential feeding of glucose to impose a constant specific growth rate. Following biomass accumulation, induction of the tac promoter by addition of IPTG was accompaied by a linear feed of yeast extract. The concentration of yeast extract feed was found to be highly influential upon both concentration and location of active product. Although scFv fragments were specifically targeted to the periplasmic space, at yeast extract feed rates of 0.72 g/h the final location was largely extracellular (68% to 79%). Total concentrations (extracellular + periplasmic) were of the order of 5 to 8 mg/L. A ten-fold increase in yeast extract supply increased total scFv concentration to almost 200 mg/L and 78% of this yield was retained in the periplasm. Control of such leakage of the recombinant product is fundamental to process design of downstream operations for product recovery. PMID:18634062

Harrison, J S; Keshavarz-Moore, E; Dunnill, P; Berry, M J; Fellinger, A; Frenken, L

1997-03-20

310

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

311

Milk production traits of beef cows as affected by horn fly count and sire breed type  

Technology Transfer Automated Retrieval System (TEKTRAN)

Horn fly infestations on beef cattle results in decreased productivity and challenges enterprise sustainability. Objective of this experiment was to determine the relationships among, cattle breed, heat shock protein 70 (Hsp70) genotype, and horn fly density. Angus (n = 20), Brahman (n = 17), and ...

312

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...

313

Lesion-Site Affects Grammatical Gender Assignment in German: Perception and Production Data  

ERIC Educational Resources Information Center

Two experiments investigated phonological, derivational-morphological and semantic aspects of grammatical gender assignment in a perception and a production task in German aphasic patients and age-matched controls. The agreement of a gender indicating adjective (feminine, masculine or neuter) and a noun was evaluated during perception in…

Hofmann, Juliane; Kotz, Sonja A.; Marschhauser, Anke; von Cramon, D. Yves; Friederici, Angela D.

2007-01-01

314

Agronomic factors affecting dryland grain sorghum maturity and production in northeast Colorado  

Technology Transfer Automated Retrieval System (TEKTRAN)

Grain sorghum [Sorghum bicolor (L.) Moench] is an important dryland crop in southeast Colorado, but expansion into northeast Colorado is thought to be limited due to the shorter growing season. The study examined whether sorghum production could be expanded into northeast Colorado. A 2-year study ...

315

Environmental, Management, and Genetic Factors Affecting Semen Production in Holstein Bulls  

Microsoft Academic Search

The objective of this study was to evaluate the importance of environment, management, physiologi- cal status, and genetics on semen quality (volume of the ejaculate, sperm concentration, sperm motility, number of sperm, and number of motile spermatozoa per ejaculate) of Canadian Holstein bulls. For this purpose, semen production data from 198 bulls were analyzed using mixed linear models. Young bulls

M. Mathevon; M. M. Buhr; J. C. M. Dekkers

1998-01-01

316

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...

317

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...

318

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

Microsoft Academic Search

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,

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

2010-01-01

319

Food from the Water: How the Fish Production Revolution Affects Aquatic Biodiversity and Food Security  

Microsoft Academic Search

The production of food from marine and freshwaters is undergoing a profound revolution—from hunting to farming or from fishing to aquaculture. Fishing and aquaculture exploit and alter the biodiversity on which they are based, each in different but convergent ways. Fishing harvests a much larger range of biodiversity at ecosystem, species and genetic levels than aquaculture. Nearly 400 aquatic species

Meryl J. Williams

2010-01-01

320

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

321

Operational patterns affecting lactic acid production in ultrafiltration cell recycle bioreactor.  

PubMed

Lactic acid production with cell recycling on an ultrafiltration tubular membrane reactor was studied; higher lactic acid concentrations as well as productivities were obtained under long-term fermentations compared with other high cell density systems. Different operational conditions, namely dilution rates and start-up modes, were assessed. Performances were very different at the three different dilution rates tested (D = 0.20 h(-1), D = 0.40 h(-1), or D = 0.58 h(-1)). The different behaviours are discussed and factors responsible for them are presented. The best way to operate for lactic acid production is chosen, the dilution rate of D = 0.40 h(-1) being the one providing the best overall performance. On the other hand, results show that of the two start-up modes tested, continuous start (membrane open) permits higher permeabilities throughout the operational runs than batch start (membrane closed). Operational stability was found to be directly associated with membranes that work at "steady state," the membrane permeability being kept around 15 L/m(2) h. Optimized cell bleed can improve time of operation if such membrane permeability can be maintained for a longer time. A comparison of results with those obtained in other lactic acid production systems is presented; such comparison shows that this tubular ultrafiltration membrane cell recycle reactor presents three important advantages: (1) concomitant lactic acid concentrations and productivities; (2) long periods of operation at reasonable permeabilities; and (3) good mechanical stability permitting the use of steam sterilization. (c) 1995 John Wiley & Sons, Inc. PMID:18623185

Xavier, A M; Gonçalves, L M; Moreira, J L; Carrondo, M J

1995-02-20

322

Precession-nutation torque in terms of the Stokes constants  

NASA Astrophysics Data System (ADS)

The precession-nutation torque of the earth-moon system is determined analytically for all degrees of spherical harmonics by combining and generalizing the standard approach of Melchior (1978) and the method of Bursa (1982, 1983). The results are given in terms of the Stokes constants of the earth. The classical and Bursa methods are shown to give the same correct results for the total torque, but only the Bursa approach correctly differentiates the partial torques.

Sidlichovsky, M.

323

Conservation of Angular-Momentum in Thermomagnetic Torque Experiments  

E-print Network

PHYSICA j REVIK W A VOLUME 11, NUMBER I JANUARY 1975 Conservation of angular momentum in thermomagnetic torque experiments* H. Vestner~ and T. W. Adair III Department of Physics, Texas 3 4 M University, College Station, Texas 77843 (Received 3... June 1974) The conservation of orbital angular momentum has the following consequence for Scott-effect experiments: The torque exerted on the outer cylinder is equal in size but opposite in direction to the torque on the inner cylinder. This is true...

Vestner, H.; Adair, Thomas W.

1975-01-01

324

Damping and synchronizing torque computation in multimachine power systems  

SciTech Connect

The paper presents a method for calculating the damping and synchronizing torques in multimachine power systems. This method is applied to evaluate the damping and synchronizing torques in interconnected power system, weakly coupled and closely coupled machines for different operating conditions and machine parameters. The investigation is enhanced by modal analysis. It is found that other approaches; namely the damping and synchronizing torques and modal analysis complement each other to provide insight into the stability of multimachine power systems.

Shaltout, A.A. (Dept. of Electrical Engineering, Jordan Univ. of Science and Technology, Irbid (JO)); Al-Feilat, E.A.A. (Dept. of Electrical Engineering, King Fahd Univ. of Petroleum and Minerals, Dhahran (SA))

1992-02-01

325

Electronic measurement of variable torques in precision work technology  

NASA Technical Reports Server (NTRS)

Approaches for the determination of torques on the basis of length measurements are discussed. Attention is given to torque determinations in which the deformation of a shaft is measured, an electric measurement of the torsion angle, and an approach proposed by Buschmann (1970). Methods for a torque determination conducted with the aid of force measurements make use of piezoelectric approaches. The components used by these methods include a quartz crystal and a charge amplifier.

Maehr, M.

1978-01-01

326

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

327

T-handle wrench has torque-limiting action  

NASA Technical Reports Server (NTRS)

T-handle wrench can be preset to release when a certain torque value is exceeded by means of a spring-loaded roller and groove torque-limiting mechanism contained in the handle of the wrench. The wrench is also equipped with a push button in the handle that permits the operator to lock the handle to the spindle shaft, thus eliminating the torque-limiting function.

Kemple, S. B.

1966-01-01

328

Small-Bolt Torque-Tension Tester  

NASA Technical Reports Server (NTRS)

The device described here measures the torque-tension relationship for fasteners as small as #0. The small-bolt tester consists of a plate of high-strength steel into which three miniature load cells are recessed. The depth of the recess is sized so that the three load cells can be shimmed, the optimum height depending upon the test hardware. The three miniature load cells are arranged in an equilateral triangular configuration with the test bolt aligned with the centroid of the three. This is a kinematic arrangement.

Posey, Alan J.

2009-01-01

329

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

330

High-Q oscillator torque magnetometer  

NASA Astrophysics Data System (ADS)

We describe a torque magnetometer for use at low temperatures based on a high-Q silicon torsional oscillator. The oscillator is fabricated using standard lithographic techniques from a single-crystal silicon wafer. The sample stage of the oscillator has an area of 0.57 cm2 and is suitable for deposition of thin magnetic film samples. Oscillator motion is detected through a capacitance measurement. The small torsion constant of the oscillator combined with a Q value >106 allow detection of magnetic moments as small as 10-13A m2. Magnetometer sensitivity is measured using small superconducting open cylinders machined from aluminum.

Biggar, R. D.; Parpia, J. M.

1998-10-01

331

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

332

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

E-print Network

Noodle Extrusion with Different Dies. Surface Gelatinization of Noodles. Di f f erent Drying Methods Salt Addition to the Sorghum Noodle Formulation. Finely and Coarsely Ground Flours. . . Standard Method Developed for Sorghum Noodle Pr oduct ion... formulations. Generally, a suitable flour for noodle production must have a bright color, good machinability to pass readily through the process, and produce an elastic cooked noodle with a clean bite (Moss 1982). Both Japanese and Chinese noodles are made...

Lekalake, Rosemary Ikalafeng

1993-01-01

333

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

334

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

335

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

336

Factors Affecting Conidial Production of Beauveria bassianafrom Fungus-Killed Cadavers of Rhodnius prolixus  

Microsoft Academic Search

The epizootic potential ofBeauveria bassianafor control of the triatomine vectors of Chagas' disease was investigated by studying the effects of both biotic and abiotic factors on the recycling of a highly virulent fungal isolate from fungus-killed cadavers ofRhodnius prolixus.The conidial production ofB. bassianafrom mummified cadavers ofR. prolixusrequired high RH levels of at least 96.5% RH. At 97% RH and 25°C,

Christian Luz; Jacques Fargues

1998-01-01

337

Competition Affects the Production of First Backcross Offspring on F 1 -hybrids, Brassica Napus × B. Rapa  

Microsoft Academic Search

Summary  Interspecific F1-hybrids may arise in fields with transplastomic oilseed rape where B. rapa occurs as a weed. Spilled seeds, including transplastomic F1-hybrids with B. rapa, may germinate, which creates an opportunity for production of transplastomic BC1 with B. rapa as father (BC1r). Field trials were made with three different proportions of B. napus, B. rapa and F1-hybrids and three different

Marina Mosbæk Johannessen; Christian Damgaard; Bente Anni Andersen; Rikke Bagger Jørgensen

2006-01-01

338

Do Commodity Prices and Food Production Affect the Volume of United States Foreign Food Aid?  

Microsoft Academic Search

The main focus of this paper is to analyze whether a country-specific commodity price index and a food production index have strong explanatory power on determining the volume of United States foreign food aid flows to low-income countries. The study uses panel data for seventy-six countries spanning from 2001-2007. I ran three regression models: two ordinary least squares regressions with

Jim Wiltsee

2009-01-01

339

The organic precursors affecting the formation of disinfection by-products with chlorine dioxide  

Microsoft Academic Search

The object of this research was to study the formation of disinfection by-products by using chlorine dioxide (ClO2) as a disinfectant reacting with different properties of organic substance in natural aquatic environment. The adsorbent resin (XAD-4, XAD-7) was used to divide the organic matters in raw water into three groups. The influence of the function groups on structure, reaction tendency,

Chen-Yu Chang; Yung-Hsu Hsieh; Yu-Min Lin; Po-Yu Hu; Chin-Chuan Liu; Kuo-Hua Wang

2001-01-01

340

Electromagnetic Torque Tweezers: A Versatile Approach for Measurement of Single-Molecule Twist and Torque  

E-print Network

of freedom. Here we present electromagnetic torque tweezers (eMTT) that combine permanent and electromagnets degrees of freedom: for example, current MTT instruments employ permanent magnets that control bothMTT combine permanent and electromagnets to enable the application of a wide range of stretching forces (from

Dekker, Nynke

341

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

342

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

343

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

344

Direct torque control of brushless DC motor with nonideal trapezoidal back EMF  

Microsoft Academic Search

In this paper a method of the torque control attenuating the undesired torque pulsation for brushless DC motor with nonideal trapezoidal back EMF is presented. It is the direct torque control method in which the applied output voltage is calculated from the reference torque and the torque of the previous step in the two-phase conducting period and in the commutation

Seog-Joo Kang; Seung-Ki Sul

1995-01-01

345

Torque-ripple minimization in switched reluctance motors using adaptive fuzzy control  

Microsoft Academic Search

An adaptive fuzzy control scheme for the torque-ripple minimization of switched reluctance machines is presented. The fuzzy parameters are initially chosen randomly and then adjusted to optimize the control. The controller produces smooth torque up to the motor base speed. The torque is generated over the maximum positive torque-producing region of a phase. This increases the torque density and avoids

S. Mir; M. E. Elbuluk; I. Husain

1999-01-01

346

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

347

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

348

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

349

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

350

Factors affecting egg production, body weight, and feed efficiency, of selected strains of cage layers  

E-print Network

throughout the experiment as shown in Tables I, and VII, and illustrated in Figure 3 ~ Ths 1 hits i. egl:orna had the lowest average sgg weight of the three production stocks involved, and the Inbred Hybrid No. 2's produced eggs of intermediate weight...FACTOHS AFF:'CTING HGG I H( DUCTION BODY HHIGHT, R(D F~D L'FFI C IHNCY, OF S"-LHCTHD S". 'H el HS OF C AGH LAYHHS By KAHSHALL MIDDLETON 1AILLsH A Thesi, s Submitted to the Graduate School of the Agricultural and hieohanlca1 College of Texas...

Miller, Marshall Middleton

1956-01-01

351

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

352

Electromagnetic force and torque in ponderable media.  

PubMed

Maxwell's macroscopic equations combined with a generalized form of the Lorentz law of force are a complete and consistent set of equations. Not only are these five equations fully compatible with special relativity, they also conform with conservation laws of energy, momentum, and angular momentum. We demonstrate consistency with the conservation laws by showing that, when a beam of light enters a magnetic dielectric, a fraction of the incident linear (or angular) momentum pours into the medium at a rate determined by the Abraham momentum density, E x H/c(2), and the group velocity V(g) of the electromagnetic field. The balance of the incident, reflected, and transmitted momenta is subsequently transferred to the medium as force (or torque) at the leading edge of the beam, which propagates through the medium with velocity V(g). Our analysis does not require "hidden" momenta to comply with the conservation laws, nor does it dissolve into ambiguities with regard to the nature of electromagnetic momentum in ponderable media. The linear and angular momenta of the electromagnetic field are clearly associated with the Abraham momentum, and the phase and group refractive indices (n(p) and n(g)) play distinct yet definitive roles in the expressions of force, torque, and momentum densities. PMID:18795019

Mansuripur, Masud

2008-09-15

353

A Clostridium acetobutylicum regulator gene (regA) affecting amylase production in Bacillus subtilis.  

PubMed

Plasmid pMET7C containing a 6.05 kb DNA insert from Clostridium acetobutylicum P262 made Escherichia coli F19 cells sensitive to metronidazole. The nucleotide sequence of the C. acetobutylicum DNA controlling metronidazole sensitivity in E. coli F19 revealed an ORF of 972 bp which encoded a protein of 324 amino acids with a calculated Mr of 35,000. The amino acid sequence encoded by the ORF contained a helix-turn-helix DNA-binding domain and was homologous to the catabolite control protein, CcpA, from Bacillus subtilis and Bacillus megaterium, a tRNA repressor of E. coli encoded by the shl gene, and the GalR, Lacl and PurR repressors of E. coli. The C. acetobutylicum ORF, which was termed regA, complemented a B. subtilis ccpA mutant and an E. coli shl mutant, but was unable to complement E. coli galR, lacl or purR mutants. To determine whether the regA gene product was involved in the regulation of amylase gene expression in C. acetobutylicum, a starch-degrading enzyme gene (staA) from C. acetobutylicum NCIMB 8052 was cloned. The RegA protein inhibited the degradation of starch by the C. acetobutylicum staA gene product in E. coli. PMID:7539689

Davison, S P; Santangelo, J D; Reid, S J; Woods, D R

1995-04-01

354

A mutation in the aroE gene affects pigment production, virulence, and chemotaxis in Xanthomonas oryzae pv. oryzae.  

PubMed

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB) in rice. To study its function, a random insertion mutation library of Xoo was constructed using the Tn5 transposon. A mutant strain with decreased virulence against the susceptible rice cultivar IR24 was isolated from the library (aroE mutant), which also had extremely low pigment production. Thermal asymmetric interlaced-polymerase chain reaction (TAIL-PCR) and sequence analysis of the mutant revealed that the transposon was inserted into the aroE gene (encoding shikimate dehydrogenase). To investigate gene expression changes in the pigment- and virulence-deficient mutant, DNA microarray analysis was performed, which showed downregulation of 20 genes involved in the chemotaxis of Xoo. Our findings reveal that mutation of the aroE gene affects virulence and pigment production, as well as expression of genes involved in Xoo chemotaxis. PMID:25213405

Kim, Hong-Il; Noh, Tae-Hwan; Lee, Chang-Soo; Park, Young-Jin

2015-01-01

355

Galactoglucomannan oligosaccharide supplementation affects nutrient digestibility, fermentation end-product production, and large bowel microbiota of the dog.  

PubMed

A galactoglucomannan oligosaccharide (GGMO) obtained from fiberboard production was evaluated as a dietary supplement for dogs. The GGMO substrate contained increased concentrations of oligosaccharides containing mannose, xylose, and glucose, with the mannose component accounting for 35% of DM. Adult dogs assigned to a 6 × 6 Latin square design were fed 6 diets, each containing a different concentration of supplemental GGMO (0, 0.5, 1, 2, 4, and 8%) that replaced dietary cellulose. Total tract DM and OM apparent digestibilities increased (P < 0.001) linearly, whereas total tract CP apparent digestibility decreased (P < 0.001) linearly as dietary GGMO substrate concentration increased. Fecal concentrations of acetate, propionate, and total short-chain fatty acids increased (P ? 0.001) linearly, whereas butyrate concentration decreased (P ? 0.001) linearly with increasing dietary concentrations of GGMO. Fecal pH decreased (P ? 0.001) linearly as dietary GGMO substrate concentration increased, whereas fecal score increased quadratically (P ? 0.001). Fecal phenol (P ? 0.05) and indole (P ? 0.01) concentrations decreased linearly with GGMO supplementation. Fecal biogenic amine concentrations were not different among treatments except for phenylethylamine, which decreased (P < 0.001) linearly as dietary GGMO substrate concentration increased. Fecal microbial concentrations of Escherichia coli, Lactobacillus spp., and Clostridium perfringens were not different among treatments. A quadratic increase (P ? 0.01) was noted for Bifidobacterium spp. as dietary GGMO substrate concentration increased. The data suggest positive nutritional properties of supplemental GGMO when incorporated in a good-quality dog food. PMID:20852078

Faber, T A; Hopkins, A C; Middelbos, I S; Price, N P; Fahey, G C

2011-01-01

356

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

357

How wing kinematics affect power requirements and aerodynamic force production in a robotic bat wing.  

PubMed

Bats display a wide variety of behaviors that require different amounts of aerodynamic force. To control and modulate aerodynamic force, bats change wing kinematics, which, in turn, may change the power required for wing motion. There are many kinematic mechanisms that bats, and other flapping animals, can use to increase aerodynamic force, e.g. increasing wingbeat frequency or amplitude. However, we do not know if there is a difference in energetic cost between these different kinematic mechanisms. To assess the relationship between mechanical power input and aerodynamic force output across different isolated kinematic parameters, we programmed a robotic bat wing to flap over a range of kinematic parameters and measured aerodynamic force and mechanical power. We systematically varied five kinematic parameters: wingbeat frequency, wingbeat amplitude, stroke plane angle, downstroke ratio, and wing folding. Kinematic values were based on observed values from free flying Cynopterus brachyotis, the species on which the robot was based. We describe how lift, thrust, and power change with increases in each kinematic variable. We compare the power costs associated with generating additional force through the four kinematic mechanisms controlled at the shoulder, and show that all four mechanisms require approximately the same power to generate a given force. This result suggests that no single parameter offers an energetic advantage over the others. Finally, we show that retracting the wing during upstroke reduces power requirements for flapping and increases net lift production, but decreases net thrust production. These results compare well with studies performed on C. brachyotis, offering insight into natural flight kinematics. PMID:24851830

Bahlman, Joseph W; Swartz, Sharon M; Breuer, Kenneth S

2014-06-01

358

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

359

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

360

Flux harmonic spectrum processing of direct torque controlled induction motor  

Microsoft Academic Search

The flux spectrum is greatly influenced by flux and torque controller hysteresis loops (dead bands) in direct torque control of AC motors. On the other hand, iron loss in induction motors is closely related to flux harmonics. Hence, the flux spectrum must be observed in the control process to minimize motor losses. In this paper, the relation between the magnetic-flux

S. Kaboli; M. R. Zolghadri

2003-01-01

361

14 CFR 23.397 - Limit control forces and -torques.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Limit control forces and -torques. 23.397 Section 23...System Loads § 23.397 Limit control forces and -torques. (a) In the control...flight from the application of any pilot force within the ranges specified in...

2010-01-01

362

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

363

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

364

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

365

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

366

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

367

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

368

Direct torque control, induction motor vector control without an encoder  

Microsoft Academic Search

The basic evolution of direct torque control from other drive types is explained. Qualitative comparisons with other drives are included. The basic concepts behind direct torque control are clarified. An explanation of direct self control and the field-orientation concepts implemented in the adaptive motor model block is presented. The reliance of the control method on fast processing techniques is stressed.

James N. Nash

1997-01-01

369

Minimization of Torque Ripple in Brushless DC Motor Drives  

Microsoft Academic Search

Torque characteristics of brushless dc motors are studied in terms of the EMF and the feed currents for two feeding schemes: two-phase feeding and three-phase feeding. Various techniques for minimizing torque ripple are considered and discussed. For three-phase feeding systems, a selective harmonics elimination technique is studied and its effectiveness is evaluated.

Hoang Le-Huy; Robert Perret; Rene Feuillet

1986-01-01

370

Driving torque distribution control system for 4wd vehicle  

Microsoft Academic Search

This patent describes a four wheel drive system for a vehicle having at least an engine, a primary driving wheel pair and a secondary driving wheel pair, comprising; a transfer mechanism for transmitting torque from the engine to the primary driving wheel pair, and transmitting torque from the engine to the secondary driving wheel pair through a transfer clutch capable

G. Naito; S. Toril; K. Ozaki

1988-01-01

371

FRICTION TORQUE AND EFFICIENCY IN BALL - SCREW SYSTEMS  

Microsoft Academic Search

Complex relations for the friction torque and efficiency in a ball-screw system has been developed. The relations was adapted for a ball-screw system and influence of the speed and load on total friction torque were investigated. The efficiency of the system was computed and good agreement with the literature results was obtained. Also, a relation for the global friction coefficient

George V. Puiu; Dumitru N. Olaru; Vasile Puiu

372

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

373

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

374

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

375

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

376

Motion control systems with ℋ? positive joint torque feedback  

Microsoft Academic Search

In this work, a new ℋ? joint torque feedback approach is proposed which takes into account the actuator's finite bandwidth dynamics, and minimizes the system's sensitivity to load torque disturbances and load dynamics. We also address implementation issues such as the development of a hydraulic dynamometer testbed for measurement of the disturbance sensitivity and of an innovative method for identifying

Farhad Aghili; Martin Buehler; John M. Hollerbach

2001-01-01

377

Analysis of torque ripple in BLDC motor with commutation time  

Microsoft Academic Search

Torque ripple generated in the commutation period is the main drawback of the brushless DC (BLDC) motor, which deteriorates its precision. Many methods to solve this problem have been studied. In many control methods, torque ripple reduction was considered at the point of current control, which means that if current can be controlled properly, the BLDC motor does not produce

Byoung-Hee Kang; Choel-Ju Kim; Hyung-Su Mok; Gyu-Ha Choe

2001-01-01

378

Core shape optimization for cogging torque reduction of BLDC motor  

Microsoft Academic Search

The cogging torque in the small brushless DC (BLDC) motors used in the digital versatile disk (DVD) driving system or hard disk drive (HDD) system can cause some serious vibration problems. In this paper, some core shapes that reduce cogging torque are found by using a reluctance network method (RNM) for magnetic field analysis and a genetic algorithm (GA) for

Ki-Jin Han; Han-Sam Cho; Dong-Hyeok Cho; Hyun-Rae Cho; Hae-Seok Lee; Hyun-Kyo Jung

1999-01-01

379

Torque feedback on the steering wheel of agricultural vehicles  

Microsoft Academic Search

The torque feedback on the steering wheel of automobiles, also known as “road feel”, is important in some driving situations. New electronic and electro-hydraulic steering systems remove the mechanical connection between the road wheel and the steering wheel, but make it possible for the designer to provide any desired torque feedback to the driver. This study was performed to investigate

Davood Karimi; Danny Mann

2009-01-01

380

Torque transmission mechanism with nonlinear passive stiffness using mechanical singularity  

Microsoft Academic Search

To introduce a passive compliant mechanism for robot joints is an effective way for impact absorption. However, because robot joints also require high torque transmission characteristic, the simultaneous implementation of stiffness and softness is a significant issue. In this paper, we develop a torque transmission mechanism with nonlinear passive stiffness that realizes from zero to extremely high stiffness based on

Masafumi Okada; Shintaro Kino

2008-01-01

381

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

382

Runners do not push off the ground but fall forwards via a gravitational torque.  

PubMed

The relationship between the affect and timing of the four forces involved in running (gravity, ground reaction force, muscle force, and potential strain energy) is presented. These forces only increase horizontal acceleration of the centre of mass during stance but not flight. The current hierarchical models of running are critiqued because they do not show gravity, a constant force, in affect during stance. A new gravitational model of running is developed, which shows gravity as the motive force. Gravity is shown to cause a torque as the runner's centre of mass moves forward of the support foot. Ground reaction force is not a motive force but operates according to Newton's third law; therefore, the ground can only propel a runner forward in combination with muscle activity. However, leg and hip extensor muscles have consistently proven to be silent during leg extension (mid-terminal stance). Instead, high muscle-tendon forces at terminal stance suggest elastic recoil regains most of the centre of mass's height. Therefore, the only external motive force from mid-terminal stance is gravity via a gravitational torque, which causes a horizontal displacement. The aim of this paper is to establish a definitive biomechanical technique (Pose method) that is easily taught to runners (Romanov, 2002): falling forwards via a gravitational torque while pulling the support foot rapidly from the ground using the hamstring muscles. PMID:17933203

Romanov, Nicholas; Fletcher, Graham

2007-09-01

383

A study of the relationship between applied and effective torque on screw fastenings  

E-print Network

and Haok-Off Torque with no Lockvasher in the Systea. . . . . . . . . . . . . . . 37 4 - F Test Results betveen Applied Torque and Hack-Off Torque with a Lockvasher in the System . . . . . . . . . . . . . . . 39 5 - F Tests Results between Applied...

Lewis, Robert Miller

1959-01-01

384

Low torque ripple control of current-fed switched reluctance motors  

Microsoft Academic Search

The paper addresses a basic control issue in switched reluctance motor (SRM) drives-the production of ripple-free torque. Simple and largely model-independent conventional switching patterns are not able to satisfy this requirement. Our goal is to improve SRM dynamical performance by compensating for motor nonlinearities while maintaining the robustness of conventional methods in a simple position and current feedback. Our method

A. M. Stankovic; GILEAD TADMOR; Z. J. Coric

1996-01-01

385

Rheological characterization of microcrystalline cellulose and silicified microcrystalline cellulose wet masses using a mixer torque rheometer.  

PubMed

The rheological properties of silicified microcrystalline cellulose (Prosolv 50) were compared with those of standard grades of microcrystalline cellulose (Emcocel 50 and Avicel PH 101). Cellulose samples were analyzed using nitrogen adsorption together with particle size, flowability, density and swelling volume studies. The rheological behaviour of the wet powder masses was studied as a function of mixing time using a mixer torque rheometer (MTR). Silicified microcrystalline cellulose exhibited improved flow characteristics and increased specific surface area compared to standard microcrystalline cellulose grades. Although the silicification process affected the swelling properties and, furthermore, the mixing kinetics of microcrystalline cellulose, the source of the microcrystalline cellulose had a stronger influence than silicification on the liquid requirement at peak torque. PMID:10518674

Luukkonen, P; Schaefer, T; Hellén, L; Juppo, A M; Yliruusi, J

1999-10-25

386

Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays  

NASA Technical Reports Server (NTRS)

Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum that the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical strategies for distributing a prescribed torque or momentum among the n wheels are presented, with special emphasis on configurations of four, five, and six wheels.

Markley, F. Landis; Reynolds, Reid G.; Liu, Frank X.; Lebsock, Kenneth L.

2009-01-01

387

Electromagnetic Torques, Precession and Evolution of Magnetic Inclination of Pulsars  

E-print Network

We present analytic calculations of the electromagnetic torques acting on a magnetic neutron star rotating in vacuum, including near-zone torques associated with the inertia of dipole and quadrupole magnetic fields. We incorporate these torques into the rotational dynamics of a rigid-body neutron star, and show that the effects of the inertial torque can be understood as a modification of the moment of inertia tensor of the star. We apply our rotational dynamics equation to the Crab pulsar, including intrinsic distortions of the star and various electromagnetic torques, to investigate the possibility that the counter-alignment of the magnetic inclination angle, as suggested by recent observations, could be explained by pulsar precession. We find that if the effective principal axis of the pulsar is nearly aligned with either the magnetic dipole axis or the rotation axis, then precession may account for the observed counter-alignment over decade timescales. Over the spindown timescale of the pulsar, the magnet...

Zanazzi, J J

2015-01-01

388

Torque Sensor Based on Tunnel-Diode Oscillator  

NASA Technical Reports Server (NTRS)

A proposed torque sensor would be capable of operating over the temperature range from 1 to 400 K, whereas a typical commercially available torque sensor is limited to the narrower temperature range of 244 to 338 K. The design of this sensor would exploit the wide temperature range and other desirable attributes of differential transducers based on tunnel-diode oscillators as described in "Multiplexing Transducers Based on Tunnel-Diode Oscillators". The proposed torque sensor would include three flexural springs that would couple torque between a hollow outer drive shaft and a solid inner drive shaft. The torque would be deduced from the torsional relative deflection of the two shafts, which would be sensed via changes in capacitances of two capacitors defined by two electrodes attached to the inner shaft and a common middle electrode attached to the outer shaft.

Chui, Talso; Young, Joseph

2008-01-01

389

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

390

Nitrate leaching to subsurface drains as affected by drain spacing and changes in crop production system.  

PubMed

Subsurface drainage is a beneficial water management practice in poorly drained soils but may also contribute substantial nitrate N loads to surface waters. This paper summarizes results from a 15-yr drainage study in Indiana that includes three drain spacings (5, 10, and 20 m) managed for 10 yr with chisel tillage in monoculture corn (Zea mays L.) and currently managed under a no-till corn-soybean [Glycine max (L.) Merr.] rotation. In general, drainflow and nitrate N losses per unit area were greater for narrower drain spacings. Drainflow removed between 8 and 26% of annual rainfall, depending on year and drain spacing. Nitrate N concentrations in drainflow did not vary with spacing, but concentrations have significantly decreased from the beginning to the end of the experiment. Flow-weighted mean concentrations decreased from 28 mg L(-1) in the 1986-1988 period to 8 mg L(-1) in the 1997-1999 period. The reduction in concentration was due to both a reduction in fertilizer N rates over the study period and to the addition of a winter cover crop as a "trap crop" after corn in the corn-soybean rotation. Annual nitrate N loads decreased from 38 kg ha(-1) in the 1986-1988 period to 15 kg ha(-1) in the 1997-1999 period. Most of the nitrate N losses occurred during the fallow season, when most of the drainage occurred. Results of this study underscore the necessity of long-term research on different soil types and in different climatic zones, to develop appropriate management strategies for both economic crop production and protection of environmental quality. PMID:15356241

Kladivko, E J; Frankenberger, J R; Jaynes, D B; Meek, D W; Jenkinson, B J; Fausey, N R

2004-01-01

391

The effect of collisions on the resonant satellite torque distribution  

NASA Astrophysics Data System (ADS)

We present numerical results of the behavior of the torque exerted by a satellite over a particulate annulus centered at a first order resonance. Results for both collisionless and collisonal annuli are presented and compared. Our results show that in the absence of particle interactions, the time required for this problem to become nonlinear scales with the satellite to planet mass ratio as ( Ms/ Mp) -2/3. In the absence of collisions, the total initial (transient) torque over the annulus is a strong function of the width of the annulus, W', around the resonance (located at rL), so that if W' ? rL( Ms/ Mp) 23, then the torque value always remains significantly below the linear standard torque. On the other hand, if W' > rL( Ms/ Mp) 23 the annulus reaches ?95% of the linear standard torque before the problem becomes nonlinear. These simulations show that when collisions are present, the critical width to obtain 95% of the linear standard torque is substantially increased, even for very low optical depth annuli. The torque value for a fixed width also depends on the time; it asymptotically approaches the linear standard torque as long as nonlinearities remain small. When collisions are introduced, initially the torque value grows up to the value it would have in the absence of collisions at time t = tcoll (for the given width), where tcoll is the mean time between collisions; for t > tcoll the torque becomes independent of the time (although not independent of the width) for the duration of the simulations.

Espresate, Julia; Lissauer, Jack J.

1999-05-01

392

Torque Splitting by a Concentric Face Gear Transmission  

NASA Technical Reports Server (NTRS)

Tests of a 167 Kilowatt (224 Horsepower) split torque face gearbox were performed by the Boeing Company in Mesa, Arizona, while working under a Defense Advanced Research Projects Agency (DARPA) Technology Reinvestment Program (TRP). This paper provides a summary of these cooperative tests, which were jointly funded by Boeing and DARPA. Design, manufacture and testing of the scaled-power TRP proof-of-concept (POC) split torque gearbox followed preliminary evaluations of the concept performed early in the program. The split torque tests were run using 200 N-m (1767 in-lbs) torque input to each side of the transmission. During tests, two input pinions were slow rolled while in mesh with the two face gears. Two idler gears were also used in the configuration to recombine torque near the output. Resistance was applied at the output face gear to create the required loading conditions in the gear teeth. A system of weights, pulleys and cables were used in the test rig to provide both the input and output loading. Strain gages applied in the tooth root fillets provided strain indication used to determine torque splitting conditions at the input pinions. The final two pinion-two idler tests indicated 52% to 48% average torque split capabilities for the two pinions. During the same tests, a 57% to 43% average distribution of the torque being recombined to the upper face gear from the lower face gear was measured between the two idlers. The POC split torque tests demonstrated that face gears can be applied effectively in split torque rotorcraft transmissions, yielding good potential for significant weight, cost and reliability improvements over existing equipment using spiral bevel gearing.

Filler, Robert R.; Heath, Gregory F.; Slaughter, Stephen C.; Lewicki, David G.

2002-01-01

393

Forces and torques on rotating spirochete flagella.  

PubMed

Spirochetes are a unique group of motile bacteria that are distinguished by their helical or flat-wave shapes and the location of their flagella, which reside within the tiny space between the bacterial cell wall and the outer membrane (the periplasm). In Borrelia burgdorferi, rotation of the flagella produces cellular undulations that drive swimming. How these shape changes arise due to the forces and torques that act between the flagella and the cell body is unknown. It is possible that resistive forces come from friction or from fluid drag, depending on whether or not the flagella are in contact with the cell wall. Here, we consider both of these cases. By analyzing the motion of an elastic flagellum rotating in the periplasmic space, we show that the flagella are most likely separated from the bacterial cell wall by a lubricating layer of fluid. This analysis then provides drag coefficients for rotation and sliding of a flagellum within the periplasm. PMID:22243185

Yang, Jing; Huber, Greg; Wolgemuth, Charles W

2011-12-23

394

Forces and Torques on Rotating Spirochete Flagella  

NASA Astrophysics Data System (ADS)

Spirochetes are a unique group of motile bacteria that are distinguished by their helical or flat-wave shapes and the location of their flagella, which reside within the tiny space between the bacterial cell wall and the outer membrane (the periplasm). In Borrelia burgdorferi, rotation of the flagella produces cellular undulations that drive swimming. How these shape changes arise due to the forces and torques that act between the flagella and the cell body is unknown. It is possible that resistive forces come from friction or from fluid drag, depending on whether or not the flagella are in contact with the cell wall. Here, we consider both of these cases. By analyzing the motion of an elastic flagellum rotating in the periplasmic space, we show that the flagella are most likely separated from the bacterial cell wall by a lubricating layer of fluid. This analysis then provides drag coefficients for rotation and sliding of a flagellum within the periplasm.

Yang, Jing; Huber, Greg; Wolgemuth, Charles W.

2011-12-01

395

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

396

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, 2011 CFR

(a) A reinforced plastic composites production facility is a new affected source if it meets all the criteria in paragraphs (a)(1) and (2) of this section. (1) You commence construction of the source after August 2,...

2011-07-01

397

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

(a) A reinforced plastic composites production facility is a new affected source if it meets all the criteria in paragraphs (a)(1) and (2) of this section. (1) You commence construction of the source after August 2,...

2010-07-01

398

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, 2012 CFR

(a) A reinforced plastic composites production facility is a new affected source if it meets all the criteria in paragraphs (a)(1) and (2) of this section. (1) You commence construction of the source after August 2,...

2012-07-01

399

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, 2013 CFR

(a) A reinforced plastic composites production facility is a new affected source if it meets all the criteria in paragraphs (a)(1) and (2) of this section. (1) You commence construction of the source after August 2,...

2013-07-01

400

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, 2014 CFR

(a) A reinforced plastic composites production facility is a new affected source if it meets all the criteria in paragraphs (a)(1) and (2) of this section. (1) You commence construction of the source after August 2,...

2014-07-01

401

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

Microsoft Academic Search

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

J. S. Hsu; D. C. W. Ayers; C. L. Coomer; R. H. Wiles

2004-01-01

402

Functional torque ratios and torque curve analysis of shoulder rotations in overhead athletes with and without impingement symptoms.  

PubMed

In this study, we evaluated the peak torque, functional torque ratios, and torque curve profile of the shoulder rotators in overhead athletes with impingement symptoms so as to examine possible alterations in response to sports training and shoulder pain. Twenty-one overhead athletes with impingement symptoms were compared with 25 overhead athletes and 21 non-athletes, none of whom were symptomatic for impingement. The participants performed five maximal isokinetic concentric and eccentric contractions of medial and lateral shoulder rotations at 1.57 rad · s(-1) and 3.14 rad · s(-1). Isokinetic peak torque was used to calculate the eccentric lateral rotation-to-concentric medial rotation and the eccentric medial rotation-to-concentric lateral rotation ratios. An analysis of the torque curve profiles was also carried out. The eccentric lateral rotation-to-concentric medial rotation torque ratio of asymptomatic athletes was lower than that of non-athletes at both test velocities. The concentric medial rotation isokinetic peak torque of the asymptomatic athletes, at 3.14 rad · s(-1), was greater than that of the non-athletes, and the peak appeared to occur earlier in the movement for athletes than non-athletes. These findings suggest that there may be adaptations to shoulder function in response to throwing practice. The eccentric medial rotation-to-concentric lateral rotation torque ratio was altered neither by the practice of university-level overhead sports nor impingement symptoms. PMID:22092229

Zanca, Gisele G; Oliveira, Ana B; Saccol, Michele F; Ejnisman, Benno; Mattiello-Rosa, Stela M

2011-12-01

403

A New Torque Control Method for Torque Ripple Minimization of BLDC Motors With UnIdeal Back EMF  

Microsoft Academic Search

In classical control of brushless dc (BLDC) motors, flux distribution is assumed trapezoidal and fed current is controlled rectangular to obtain a desired constant torque. However, in reality, this assumption may not always be correct, due to nonuniformity of magnetic material and design trade-offs. These factors, together with current controller limitation, can lead to an undesirable torque ripple. This paper

Haifeng Lu; Lei Zhang; Wenlong Qu

2008-01-01

404

Accretion Disk Torqued by a Black Hole  

E-print Network

If a Kerr black hole is connected to a disk rotating around it by a magnetic field, the rotational energy of the Kerr black hole provides an energy source for the radiation of the disk in addition to disk accretion. The black hole exerts a torque on the disk, which transfers energy and angular momentum between the black hole and the disk. If the black hole rotates faster than the disk, energy and angular momentum are extracted from the black hole and transfered to the disk. The energy deposited into the disk is eventually radiated away by the disk, which will increase the efficiency of the disk. If the black hole rotates slower than the disk, energy and angular momentum are transfered from the disk to the black hole, which will lower the efficiency of the disk. With suitable boundary conditions, quasi-steady state solutions are obtained for a thin Keplerian disk magnetically coupled to a Kerr black hole. By ``quasi-steady state'' we mean that any macroscopic quantity at a given radius in the disk slowly changes with time: the integrated change within one rotation period of the disk is much smaller than the quantity itself. We find that, the torque produced by the magnetic coupling propagates only outward in the disk, the total radiation flux of the disk is a superposition of the radiation flux produced by the magnetic coupling and that produced by accretion. Most interestingly, a disk magnetically coupled to a rapidly rotating black hole can radiate without accretion. Such a disk has an infinite efficiency. For a specific example that the magnetic field touches the disk at the inner boundary, the radial radiation profile is very different from that of a standard accretion disk: the emissivity index is significantly bigger, most radiation comes from a region which is closer to the center of the disk.

Li-Xin Li

2001-03-09

405

Hydrolysis and redox factors affecting analysis of common phenolic marker compounds in botanical extracts and finished products.  

PubMed

Many of the marker compounds analyzed in herbal products are redox-active phenolic molecules, which are commonly found in plants as components of glycosides and starch polymers. Variability in degree of sample hydrolysis can occur due to differences in water content, pH, and temperature. Sonication versus shaking during extraction can also influence hydrolysis and oxidation of sensitive compounds. Some traditional botanical extract marker compounds are esters and glycosides of phenolics such as echinacoside from Echinacea while others are free phenolics, such as quercetin from glycosides in Ginkgo. Optimizing hydrolysis conditions maximizes free quercetin levels, but lowers echinacoside levels. Furthermore, acidic hydrolysis conditions mimic stomach conditions encountered by oral supplements and protect resulting free phenolics from oxidation. Oxidative degradation of botanical phenolic markers can be initiated by light, sonication, oxygen, basic pH conditions, heat, redox-active solvents, and formulation additives. Some phenolic markers reversibly cycle through multiple oxidation states creating a formula-specific equilibrium of oxidation states. Finished product formulations that include easily oxidized phenolics, carbonates, phosphates, and transition metals affect sample hydrolysis degree and redox equilibria, and quantitation. By recognizing and controlling hydrolysis and oxidation variables, more accurate and rugged methods can be developed allowing for improved botanical standardization and finished product analysis. PMID:11048854

Baugh, S; Ignelzi, S

2000-01-01

406

Milk production traits of beef cows as affected by horn fly count and sire breed type.  

PubMed

Horn fly infestations negatively impact economic traits of beef cattle. Our objective was to determine the impact of horn flies on beef cattle milk yield and quality. Cows (n = 53) were derived from Brangus dams and sired by Bonsmara (n = 7), Brangus (n = 13), Charolais (n = 8), Gelbvieh (n = 5), Hereford (n = 12), and Romosinuano (n = 8) bulls. Horn fly counts and estimates of milk yield and quality were recorded monthly from May through October on individual cows. Data for milk yield and quality and horn fly count were analyzed by mixed model least squares using a linear model including sire breed, cow in sire breed, month, and month × sire breed. Effects of horn fly count on milk yield and quality were estimated by analysis of covariance using log horn fly count and log horn fly count × sire breed. Horn fly counts varied by month (P < 0.0001), with lowest population recorded in May (99 flies) and peaked in August (520 flies). Bonsmara and Gelbvieh sired cows had greater (P < 0.05) milk yield compared to Hereford sired cows (8.75 and 8.62 vs. 6.02 kg/d, respectively). Milk yield from Charolais, Romosinuano, and Brangus sired cows was intermediate (7.28, 7.00, and 7.06 kg/d, respectively). Regression of milk yield on fly count differed (P < 0.05) among sire breeds. Milk yield was reduced (P < 0.05) by 0.99 and 0.64 kg/d per unit increase in log horn fly count in Gelbvieh and Bonsmara sired cows. Regression coefficient for milk yield on log horn fly count was reduced (P < 0.01) in Gelbvieh sired cows when compared with Brangus, Charolais, Hereford, and Romosinuano sired cows, and coefficients for Bonsmara sired cows were reduced (P < 0.05) in comparison to Brangus sired cows. Increases in log fly count were associated with decreases (P < 0.05) in milk fat, solids-not-fat, and milk urea nitrogen. Milk yield was reduced (P < 0.05) by increased fly numbers depending on month of lactation and interaction with log horn fly count. In May, June, and July milk yield was reduced 0.72, 0.68, and 0.71 kg/d per unit increase in log horn fly count. Our results indicate that horn fly infestations reduce milk yield and quality of spring-calving beef cows depending on sire breed and month of lactation. Development of sustainable beef production systems may include selecting breed types whose milk yield and quality is less influenced by horn flies, allowing for better expression of genetic potential for milk yield in nutritionally challenging environments. PMID:24492544

Mays, A R; Brown, M A; von Tunglen, D L; Rosenkrans, C F

2014-03-01

407

In situ production of ethane and propane in dust-rich Greenland ice core samples: is methane also affected?  

NASA Astrophysics Data System (ADS)

The analysis of methane and the stable isotopic composition extracted from ice core samples provides a suite of valuable climatic sensitive parameters like CH4 mixing ratios, d13C(CH4), dD(CH4) and the respective interhemispheric differences of these parameters. Their interpretation as palaeoclimatic proxies relies on the assumption that the measured properties represent true atmospheric concentrations after correction for the well-known diffusive processes in the firn column. Up to now, methane is assumed to be unaffected from in situ production with the exception of melt layers and alpine ice cores which show elevated concentrations. In contrast, other trace gases like CO2 and N2O show in situ production under certain conditions, especially in dust-rich Greenland ice core samples. Also other trace gases which are chemically more related to methane, like the hydrocarbons ethane and propane as well as methyl chloride show pronounced in situ production in some ice cores. To explore the processes leading to situ production for ethane and propane and a possible link to methane it is helpful to measure these parameters simultaneously on a single ice core sample. For this task we present a new online preparation line for extraction and measurement of several trace gas species (isotope ratios and/or mixing ratios) of 150-200 g ice samples. The analytical setup comprises continuous flow-isotope ratio mass spectrometry and a custom-built online pre-concentration system with a vacuum extraction part and a continuous He flow GC line. Our setup allows for analysing isotope ratios of CH4(13C) and N2O (d15N, d18O) as well as their mixing ratios and, additionally, the mixing ratios of ethane, propane and methyl chloride. We measured ice core samples on the NGRIP ice core during, selected time intervals covering DO events, the LGM and, the Bølling/Allerød Younger Dryas. Where possible, we focused on intervals where dust showed its larges variability. In summary, we see a strong in situ production for ethane, propane and methyl chloride related to dust concentrations in Greenland ice. However, methane is likely not affected by this production pathway or the contribution is so small that it is hidden in the atmospheric signal so far. A better sampling strategy focusing with a denser temporal coverage on intervals with variable dust loading could further constrain a possible contribution of methane from in situ production.

Schmitt, J.; Seth, B.; Fischer, H.

2012-04-01

408

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

409

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

410

Algorithm for calculating torque base in vehicle traction control system  

NASA Astrophysics Data System (ADS)

Existing research on the traction control system(TCS) mainly focuses on control methods, such as the PID control, fuzzy logic control, etc, aiming at achieving an ideal slip rate of the drive wheel over long control periods. The initial output of the TCS (referred to as the torque base in this paper), which has a great impact on the driving performance of the vehicle in early cycles, remains to be investigated. In order to improve the control performance of the TCS in the first several cycles, an algorithm is proposed to determine the torque base. First, torque bases are calculated by two different methods, one based on states judgment and the other based on the vehicle dynamics. The confidence level of the torque base calculated based on the vehicle dynamics is also obtained. The final torque base is then determined based on the two torque bases and the confidence level. Hardware-in-the-loop(HIL) simulation and vehicle tests emulating sudden start on low friction roads have been conducted to verify the proposed algorithm. The control performance of a PID-controlled TCS with and without the proposed torque base algorithm is compared, showing that the proposed algorithm improves the performance of the TCS over the first several cycles and enhances about 5% vehicle speed by contrast. The proposed research provides a more proper initial value for TCS control, and improves the performance of the first several control cycles of the TCS.

Li, Hongzhi; Li, Liang; Song, Jian; Wu, Kaihui; Qiao, Yanjuan; Liu, Xingchun; Xia, Yongguang

2012-11-01

411

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

412

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

413

Accurate torque-speed performance prediction for brushless dc motors  

NASA Astrophysics Data System (ADS)

Desirable characteristics of the brushless dc motor (BLDCM) have resulted in their application for electrohydrostatic (EH) and electromechanical (EM) actuation systems. But to effectively apply the BLDCM requires accurate prediction of performance. The minimum necessary performance characteristics are motor torque versus speed, peak and average supply current and efficiency. BLDCM nonlinear simulation software specifically adapted for torque-speed prediction is presented. The capability of the software to quickly and accurately predict performance has been verified on fractional to integral HP motor sizes, and is presented. Additionally, the capability of torque-speed prediction with commutation angle advance is demonstrated.

Gipper, Patrick D.

414

High torque DC motor fabrication and test program  

NASA Technical Reports Server (NTRS)

The testing of a standard iron and standard alnico permanent magnet two-phase, brushless dc spin motor for potential application to the space telescope has been concluded. The purpose of this study was to determine spin motor power losses, magnetic drag, efficiency and torque speed characteristics of a high torque dc motor. The motor was designed and built to fit an existing reaction wheel as a test vehicle and to use existing brass-board commutation and torque command electronics. The results of the tests are included in this report.

Makus, P.

1976-01-01

415

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

416

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

417

A Sensorless Direct Torque Control Scheme Suitable for Electric Vehicles  

E-print Network

the vehicle dynamics. Simulations were first carried out on a test vehicle propelled by a 37-kW induction, direct torque control, vehicle dynamics. I. INTRODUCTION Recently a lot of effort was focused

Paris-Sud XI, Université de

418

On the stress and torque tensors in fluid membranes  

E-print Network

We derive the membrane elastic stress and torque tensors using the standard Helfrich model and a direct variational method in which the edges of a membrane are infinitesimally translated and rotated. We give simple expressions of the stress and torque tensors both in the local tangent frame and in projection onto a fixed frame. We recover and extend the results of Capovilla and Guven [J. Phys. A, 2002, \\textbf{35}, 6233], which were obtained using covariant geometry and Noether's theorem: we show that the Gaussian rigidity contributes to the torque tensor and we include the effect of a surface potential in the stress tensor. Many interesting situations may be investigated directly using force and torque balances instead of full energy minimization. As examples, we consider the force exerted at the end of a membrane tubule, membrane adhesion and domain contact conditions.

Jean-Baptiste Fournier

2007-02-12

419

Mechanism and assessment of spin transfer torque (STT) based memory  

E-print Network

When a sufficient current density passes through the MTJ, the spin-polarized current will exert a spin transfer torque to switch the magnetization of the free layer. This is the fundamental of the novel write mechanism in ...

Loh, Iong Ying

2009-01-01

420

Reflection mechanism for generating spin transfer torque without charge current  

NASA Astrophysics Data System (ADS)

A reflection mechanism for generating spin-transfer torque is proposed. It is due to interference of bias-driven nonequilibrium electrons incident on a switching junction, with the electrons reflected from an insulating barrier inserted in the junction after the switching magnet. It is shown, using the rigorous Keldysh formalism, that this out-of-plane torque T? is proportional to an applied bias and is as large as the torque in a conventional junction generated by a strong charge current. However, the charge current and the in-plane torque T? are almost completely suppressed by the insulating barrier. This junction thus offers the highly applicable possibility of bias-induced switching of magnetization without charge current.

Autès, G.; Mathon, J.; Umerski, A.

2012-03-01

421

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

422

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

423

Pathogenesis and genetic diversity of rodent Torque teno virus   

E-print Network

Torque teno virus (TTV) is a single stranded circular DNA virus and, despite its widespread nature in the human population, its pathogenesis is still unknown. Factors complicating TTV research include its huge genetic diversity, difficulties...

Nishiyama, Shoko

2013-11-29

424

Spin-transfer torques in antiferromagnetic metals from first principles.  

PubMed

In spite of the absence of a macroscopic magnetic moment, an antiferromagnet is spin-polarized on an atomic scale. The electric current passing through a conducting antiferromagnet is polarized as well, leading to spin-transfer torques when the order parameter is textured, such as in antiferromagnetic noncollinear spin valves and domain walls. We report a first principles study on the electronic transport properties of antiferromagnetic systems. The current-induced spin torques acting on the magnetic moments are comparable with those in conventional ferromagnetic materials, leading to measurable angular resistances and current-induced magnetization dynamics. In contrast to ferromagnets, spin torques in antiferromagnets are very nonlocal. The torques acting far away from the center of an antiferromagnetic domain wall should facilitate current-induced domain wall motion. PMID:18643438

Xu, Yuan; Wang, Shuai; Xia, Ke

2008-06-01

425

Helicopter transmission arrangements with split-torque gear trains  

NASA Technical Reports Server (NTRS)

As an alternative to component development, the case for improved drive-train configuration is argued. In particular, the use of torque-splitting gear trains is proposed as a practicable means of improving the effectiveness of helicopter main gearboxes.

White, G.

1983-01-01

426

Estimation of Coriolis Force and Torque Acting on Ares-1  

NASA Technical Reports Server (NTRS)

A document describes work on the origin of Coriolis force and estimating Coriolis force and torque applied to the Ares-1 vehicle during its ascent, based on an internal ballistics model for a multi-segmented solid rocket booster (SRB).

Mackey, Ryan M.; Kulikov, Igor K.; Smelyanskiy, Vadim; Luchinsky, Dmitry; Orr, Jeb

2011-01-01

427

Design considerations of sinusoidally excited permanent magnet machines for low torque ripple applications  

Microsoft Academic Search

Several high performance applications such as electric power steering require, the motor drive to produce smooth torque with very stringent torque ripple requirement. This paper is focused on various machine design considerations that can be used in reducing the torque ripple of a sinusoidally excited permanent magnet (PM) brushless DC (BLDC) motor. The paper quantifies the various sources of torque

Mohammad S. Islam; Sayeed Mir; Tomy Sebastian; Samuel Underwood

2004-01-01

428

Orion - Super Koropon(Registered Trademark) Torque/Tension Report  

NASA Technical Reports Server (NTRS)

The primary objective of this testing was to obtain torque tension data for the use of Super Koropon Primer Base which was proposed for use on the Orion project. This compound is a corrosion inhibitor/sealer used on threaded fasteners and inserts as specified per NASA/JSC PRC-4004, Sealing of Joints and Faying Surfaces. Some secondary objectives of this testing, were to identify the effect on torque coefficient of several variables. This document contains the outcome of the testing.

Hemminger, Edgar G.; McLeod, Christopher; Peil, John

2012-01-01

429

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

430

Advanced Torque and Drag Considerations in Extended-Reach Wells  

Microsoft Academic Search

Excessive torque and drag can be critical limitations in extended-reach drilling (ERD). This paper details issues related to torque-and-drag prediction, monitoring, and management in ERD wells. Results are presented from sensitivity analyses of extreme ERD trajectories such as 7- to 8-km departures at 1,600 m true vertical depth (TVD). Several such wells have now been successfully drilled at the Wytch

M. L. Payne; F. Abbassian

1997-01-01

431

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

432

Torques without Rotation: the Right-Angle Lever  

E-print Network

An extended body subject to external forces which exert zero net force and zero total torque in the rest frame, may experience a nonzero torque in another inertial frame, and nonetheless does not rotate. Long known as the Trouton-Noble or right-angle lever paradox, there has been extensive discussion and indeed controversy, but a clear understanding comes from a suitable treatment of angular momentum and simultaneity.

Joel A. Shapiro

2012-06-20

433

Torques without Rotation: the Right-Angle Lever  

E-print Network

An extended body subject to external forces which exert zero net force and zero total torque in the rest frame, may experience a nonzero torque in another inertial frame, and nonetheless does not rotate. Long known as the Trouton-Noble or right-angle lever paradox, there has been extensive discussion and indeed controversy, but a clear understanding comes from a suitable treatment of angular momentum and simultaneity.

Shapiro, Joel A

2012-01-01

434

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

435

Torque-velocity relationship in isokinetic cycling exercise.  

PubMed

Seven healthy female subjects performed brief (less than 10 s) periods of maximal exercise on a constant-velocity cycle ergometer, over the functional range of pedaling velocities, and an isometric contraction with each leg. There was an inverse relationship between peak torque and pedal crank velocity in all subjects; isometric torque was (mean +/- SE) 19.8 +/- 8.3% greater than the torque recorded at the slowest velocity of 11 rpm. The torque-velocity relationship was described best by a single exponential equation: y = 189.6 X e-0.0834x, where y is peak torque in Newton . meters and x is crank velocity in revolutions per minute. Peak power was a parabolic function of crank velocity; the data were fitted suitably by a second-order polynomial equation: y = -0.0589x2 + 14.504x + 47.092, where y is peak power in watts and x is crank velocity in revolutions per minute. Maximal peak power occurred at crank velocities ranging from 120 to 160 rpm, when the torque was 0.36 +/- 0.06 of the maximal isometric tension. These results demonstrate the importance of recording velocity in measurements of dynamic maximal power. PMID:3997712

McCartney, N; Obminski, G; Heigenhauser, G J

1985-05-01

436

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

437

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

438

Helicopter anti-torque system using fuselage strakes  

NASA Technical Reports Server (NTRS)

The improvement of the helicopter torque control system is discussed. At low to medium forward speeds helicopter performance is limited by the effectiveness of the means for counteracting main rotor torque and controlling sideslip airloads. These problems may be overcome by mounting strakes on the aft fuselage section. For single rotor helicopters whose main rotor rotates counter-clockwise as viewed from above, one of the strakes would be mounted in the upper lefthand quadrant and the second in the lower left hand quadrant. The strakes alter the air flow around the fuselage by separating the flow so as to produce lateral airloads on the tail boom which oppose main-rotor torque. The upper strake operates in a right crosswind to oppose main rotor torque, and the lower strake has effect in left crosswinds. The novelty of this invention resides in the simple and economical manner in which the helicopter tail boom may be modified by the addition of strakes in order to increase torque control, and reduce the need for supplemental mechanical means of torque control.

Kelley, Henry L. (inventor); Wilson, John C. (inventor)

1987-01-01

439

Immediate compensation for variations in self-generated Coriolis torques related to body dynamics and carried objects  

PubMed Central

We have previously shown that the Coriolis torques that result when an arm movement is performed during torso rotation do not affect movement trajectory. Our purpose in the present study was to examine whether torso motion-induced Coriolis and other interaction torques are counteracted during a turn and reach (T&R) movement when the effective mass of the hand is augmented, and whether the dominant arm has an advantage in coordinating intersegmental dynamics as predicted by the dynamic dominance hypothesis (Sainburg RL. Exp Brain Res 142: 241–258, 2002). Subjects made slow and fast T&R movements in the dark to just extinguished targets with either arm, while holding or not holding a 454-g object. Movement endpoints were equally accurate at both speeds, with either hand, and in both weight conditions, but subjects tended to angularly undershoot and produce more variable endpoints for targets requiring greater torso rotation. There were no changes in endpoint accuracy or trajectory deviation over repeated movements. The dominant right arm was more stable in its control of trajectory direction across targets, whereas the nondominant left arm had an improved ability to stop accurately on the target for higher levels of interaction torques. The trajectories to more eccentric targets were straighter when performed at higher speeds but slightly more deviated when subjects held the weight. Subjects did not slow their torso velocity or change the timing of the arm and torso velocities when holding the weight, although there was a slight decrease in their hand velocity relative to the torso. The delay between the onsets of torso and finger movements was almost twice as large for the right arm than the left, suggesting the right arm was better able to account for torso rotation in the arm movement. Holding the weight increased the peak Coriolis torque by 40% at the shoulder and 45% at the elbow and, for the most eccentric target, increased the peak net torque by 12% at the shoulder and 34% at the elbow. In accordance with Sainburg's dynamic dominance hypothesis, the right arm exhibited an advantage for coordinating intersegmental dynamics, showing a more stable finger velocity in relation to the torso across targets, decreasing error variability with movement speed, and more synchronized peaks of finger relative and torso angular velocities in conditions with greater joint torque requirements. The arm used had little effect on the movement path and the magnitude of the joint torques in any of the conditions. These results indicate that compensations for forthcoming Coriolis torque variations take into account the dynamic properties of the body and of external objects, as well as the planned velocities of the torso and arm. PMID:23803330

DiZio, Paul; Lackner, James R.

2013-01-01

440

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

441

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

442

Environmental Factors Affecting Production, Release, and Field Populations of Conidia of Alternaria alternata, the Cause of Brown Spot of Citrus.  

PubMed

ABSTRACT Alternaria brown spot, caused by Alternaria alternata pv. citri, affects many tangerines and their hybrids, causing loss of immature leaves and fruit and reducing the marketability of the remaining fruit. Conidial production of A. alternata was greatest on mature leaves moistened and maintained at near 100% relative humidity (RH) for 24 h, whereas leaves that had been soaked or maintained at moderate RH produced few conidia. Conidial release from filter paper cultures and infected leaves was studied in a computer-controlled environmental chamber. Release of large numbers of conidia was triggered from both substrates by sudden drops in RH or by simulated rainfall events. Vibration induced release of low numbers of conidia, but red/infrared irradiation had no effect. In field studies from 1994 to 1996, air sampling with a 7-day recording volumetric spore trap indicated that conidia were present throughout the year with periodic large peaks. The number of conidia captured was not closely related to rainfall amounts or average wind speed, but was weakly related to the duration of leaf wetness. Likewise, disease severity on trap plants placed in the field weekly during 1995 to 1996 was not closely related to conidial numbers or rainfall amounts, but was weakly related to leaf wetness duration. Sufficient inoculum appears to be available to allow infection to occur throughout the year whenever susceptible host tissue and moisture are available. PMID:18944857

Timmer, L W; Solel, Z; Gottwald, T R; Ibañez, A M; Zitko, S E

1998-11-01

443

The catabolite control protein E (CcpE) affects virulence determinant production and pathogenesis of Staphylococcus aureus.  

PubMed

Carbon metabolism and virulence determinant production are often linked in pathogenic bacteria, and several regulatory elements have been reported to mediate this linkage in Staphylococcus aureus. Previously, we described a novel protein, catabolite control protein E (CcpE) that functions as a regulator of the tricarboxylic acid cycle. Here we demonstrate that CcpE also regulates virulence determinant biosynthesis and pathogenesis. Specifically, deletion of ccpE in S. aureus strain Newman revealed that CcpE affects transcription of virulence factors such as capA, the first gene in the capsule biosynthetic operon; hla, encoding ?-toxin; and psm?, encoding the phenol-soluble modulin cluster ?. Electrophoretic mobility shift assays demonstrated that CcpE binds to the hla promoter. Mice challenged with S. aureus strain Newman or its isogenic ?ccpE derivative revealed increased disease severity in the ?ccpE mutant using two animal models; an acute lung infection model and a skin infection model. Complementation of the mutant with the ccpE wild-type allele restored all phenotypes, demonstrating that CcpE is negative regulator of virulence in S. aureus. PMID:25193664

Hartmann, Torsten; Baronian, Grégory; Nippe, Nadine; Voss, Meike; Schulthess, Bettina; Wolz, Christiane; Eisenbeis, Janina; Schmidt-Hohagen, Kerstin; Gaupp, Rosmarie; Sunderkötter, Cord; Beisswenger, Christoph; Bals, Robert; Somerville, Greg A; Herrmann, Mathias; Molle, Virginie; Bischoff, Markus

2014-10-24

444

Minimization of torque pulsations in a trapezoidal back-EMF permanent magnet brushless DC motor  

Microsoft Academic Search

This paper discusses the different methods used to reduce the torque pulsations (i.e. cogging torque and torque ripple) in a trapezoidal back-EMF permanent magnet (PM) brushless DC motor. The paper covers the design options to reduce both cogging torque and torque ripple. The effect of stator ampere-turns, the influence of rotor magnetization and the effect of the processing of electrical

Sunil Murthy; Benoit Derouane; Buyun Liu; Tomy Sebastian

1999-01-01

445

A Complex Fuzzy Controller for Reducing Torque Ripple of Brushless DC Motor  

Microsoft Academic Search

\\u000a The Brushless DC Motor (BLDC) has been applied widely for its high torque density, high efficiency and small size, but its\\u000a torque ripple is relatively high. In recent years, some scholars apply direct torque control to BLDC, for reducing torque\\u000a ripple by means of the fast response of torque. Based on this theory, this paper presents a complex fuzzy controller

Zhanyou Wang; Shunyi Xie; Zhirong Guo

2009-01-01

446

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

447

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

448

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

449

Advanced Glycation End-Products Reduce Collagen Molecular Sliding to Affect Collagen Fibril Damage Mechanisms but Not Stiffness  

PubMed Central

Advanced glycation end-products (AGE) contribute to age-related connective tissue damage and functional deficit. The documented association between AGE formation on collagens and the correlated progressive stiffening of tissues has widely been presumed causative, despite the lack of mechanistic understanding. The present study investigates precisely how AGEs affect mechanical function of the collagen fibril – the supramolecular functional load-bearing unit within most tissues. We employed synchrotron small-angle X-ray scattering (SAXS) and carefully controlled mechanical testing after introducing AGEs in explants of rat-tail tendon using the metabolite methylglyoxal (MGO). Mass spectrometry and collagen fluorescence verified substantial formation of AGEs by the treatment. Associated mechanical changes of the tissue (increased stiffness and failure strength, decreased stress relaxation) were consistent with reports from the literature. SAXS analysis revealed clear changes in molecular deformation within MGO treated fibrils. Underlying the associated increase in tissue strength, we infer from the data that MGO modified collagen fibrils supported higher loads to failure by maintaining an intact quarter-staggered conformation to nearly twice the level of fibril strain in controls. This apparent increase in fibril failure resistance was characterized by reduced side-by-side sliding of collagen molecules within fibrils, reflecting lateral molecular interconnectivity by AGEs. Surprisingly, no change in maximum fibril modulus (2.5 GPa) accompanied the changes in fibril failure behavior, strongly contradicting the widespread assumption that tissue stiffening in ageing and diabetes is directly related to AGE increased fibril stiffness. We conclude that AGEs can alter physiologically relevant failure behavior of collagen fibrils, but that tissue level changes in stiffness likely occur at higher levels of tissue architecture. PMID:25364829

Fessel, Gion; Li, Yufei; Diederich, Vincent; Guizar-Sicairos, Manuel; Schneider, Philipp; Sell, David R.; Monnier, Vincent M.; Snedeker, Jess G.

2014-01-01

450

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

451

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

452

Nanomagnonic devices based on the spin-transfer torque  

NASA Astrophysics Data System (ADS)

Magnonics is based on signal transmission and processing by spin waves (or their quanta, called magnons) propagating in a magnetic medium. In the same way as nanoplasmonics makes use of metallic nanostructures to confine and guide optical-frequency plasmon-polaritons, nanomagnonics uses nanoscale magnetic waveguides to control the propagation of spin waves. Recent advances in the physics of nanomagnetism, such as the discovery of spin-transfer torque, have created possibilities for nanomagnonics. In particular, it was recently demonstrated that nanocontact spin-torque devices can radiate spin waves, serving as local nanoscale sources of signals for magnonic applications. However, the integration of spin-torque sources with nanoscale magnetic waveguides, which is necessary for the implementation of integrated spin-torque magnonic circuits, has not been achieved to date. Here, we suggest and experimentally demonstrate a new approach to this integration, utilizing dipolar field-induced magnonic nanowaveguides. The waveguides exhibit good spectral matching with spin-torque nano-oscillators and enable efficient directional transmission of spin waves. Our results provide a practical route for the implementation of integrated magnonic circuits utilizing spin transfer.

Urazhdin, S.; Demidov, V. E.; Ulrichs, H.; Kendziorczyk, T.; Kuhn, T.; Leuthold, J.; Wilde, G.; Demokritov, S. O.

2014-07-01

453

Estimation of muscle torque in various combat sports.  

PubMed

The purpose of the research was to compare muscle torque of elite combat groups. Twelve taekwondo WTF athletes, twelve taekwondo ITF athletes and nine boxers participated in the study. Measurements of muscle torques were done under static conditions on a special stand which belonged to the Department of Biomechanics. The sum of muscle torque of lower right and left extremities of relative values was significantly higher for taekwondo WTF athletes than for boxers (16%, p < 0.001 for right and 10%, p < 0.05 for left extremities) and taekwondo ITF (10%, p < 0.05 for right and 8% for left extremities). Taekwondo ITF athletes attained significantly higher absolute muscle torque values than boxers for elbow flexors (20%, p < 0.05 for right and 11% for left extremities) and extensors (14% for right and 18%, p < 0.05 for left extremities) and shoulder flexors (10% for right and 12%, p < 0.05 for left extremities) and extensors (11% for right and 1% for left extremities). Taekwondo WTF and taekwondo ITF athletes obtained significantly different relative values of muscle torque of the hip flexors (16%, p < 0.05) and extensors (11%, p < 0.05) of the right extremities. PMID:23394114

P?dzich, Wioletta; Mastalerz, Andrzej; Sadowski, Jerzy

2012-01-01

454

Joint torque reduction of a three dimensional redundant planar manipulator.  

PubMed

Research on joint torque reduction in robot manipulators has received considerable attention in recent years. Minimizing the computational complexity of torque optimization and the ability to calculate the magnitude of the joint torque accurately will result in a safe operation without overloading the joint actuators. This paper presents a mechanical design for a three dimensional planar redundant manipulator with the advantage of the reduction in the number of motors needed to control the joint angle, leading to a decrease in the weight of the manipulator. Many efforts have been focused on decreasing the weight of manipulators, such as using lightweight joints design or setting the actuators at the base of the manipulator and using tendons for the transmission of power to these joints. By using the design of this paper, only three motors are needed to control any n degrees of freedom in a three dimensional planar redundant manipulator instead of n motors. Therefore this design is very effective to decrease the weight of the manipulator as well as the number of motors needed to control the manipulator. In this paper, the torque of all the joints are calculated for the proposed manipulator (with three motors) and the conventional three dimensional planar manipulator (with one motor for each degree of freedom) to show the effectiveness of the proposed manipulator for decreasing the weight of the manipulator and minimizing driving joint torques. PMID:22969326

Yahya, Samer; Moghavvemi, Mahmoud; Almurib, Haider Abbas F

2012-01-01

455

Spin-transfer torque in spin filter tunnel junctions  

NASA Astrophysics Data System (ADS)

Spin-transfer torque in a class of magnetic tunnel junctions with noncollinear magnetizations, referred to as spin filter tunnel junctions, is studied within the tight-binding model using the nonequilibrium Green's function technique within Keldysh formalism. These junctions consist of one ferromagnet (FM) adjacent to a magnetic insulator (MI) or two FM separated by a MI. We find that the presence of the magnetic insulator dramatically enhances the magnitude of the spin-torque components compared to conventional magnetic tunnel junctions. The fieldlike torque is driven by the spin-dependent reflection at the MI/FM interface, which results in a small reduction of its amplitude when an insulating spacer (S) is inserted to decouple MI and FM layers. Meanwhile, the dampinglike torque is dominated by the tunneling electrons that experience the lowest barrier height. We propose a device of the form FM/(S)/MI/(S)/FM that takes advantage of these characteristics and allows for tuning the spin-torque magnitudes over a wide range just by rotation of the magnetization of the insulating layer.

Ortiz Pauyac, Christian; Kalitsov, Alan; Manchon, Aurelien; Chshiev, Mairbek

2014-12-01

456

Torque on birefringent plates induced by quantum fluctuations  

SciTech Connect

We present detailed numerical calculations of the mechanical torque induced by quantum fluctuations on two parallel birefringent plates with in-plane optical anisotropy, separated by either vacuum or a liquid (ethanol). The torque is found to vary as sin(2{theta}), where {theta} represents the angle between the two optical axes, and its magnitude rapidly increases with decreasing plate separation d. For a 40 {mu}m diameter disk, made out of either quartz or calcite, kept parallel to a barium titanate plate at d{approx_equal}100 nm, the maximum torque (at {theta}={pi}/4) is of the order of {approx_equal}10{sup -19} N m. We propose an experiment to observe this torque when the barium titanate plate is immersed in ethanol and the other birefringent disk is placed on top of it. In this case the retarded van der Waals (or Casimir-Lifshitz) force between the two birefringent slabs is repulsive. The disk would float parallel to the plate at a distance where its net weight is counterbalanced by the retarded van der Waals repulsion, free to rotate in response to very small driving torques.

Munday, Jeremy N. [Harvard University, Department of Physics, Cambridge, Massachusetts 02138 (United States); Iannuzzi, Davide; Capasso, Federico [Harvard University, Division of Engineering and Applied Sciences, Cambridge, Massachusetts 02138 (United States); Barash, Yuri [Institute of Solid State Physics, Russian Academy of Sciences, Institutskaya ul. 2, Chernogolovka, Moscow region 142432 (Russian Federation)

2005-04-01

457

Reconstruction of Twist Torque in Main Parachute Risers  

NASA Technical Reports Server (NTRS)

The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

Day, Joshua D.

2015-01-01

458

EMG activity of trunk muscles and torque output during isometric axial rotation exertion: a comparison between back pain patients and matched controls  

Microsoft Academic Search

Abnormal patterns of trunk muscle activity could affect the biomechanics of spinal movements and result in back pain. The present study aimed to examine electromyographic (EMG) activity of abdominal and back muscles as well as triaxial torque output during isometric axial rotation at different exertion levels in back pain patients and matched controls. Twelve back pain patients and 12 matched

Joseph K.-F. Ng; Carolyn A. Richardson; Mohamad Parnianpour; Vaughan Kippers

2002-01-01

459

A testing machine for dental air-turbine handpiece characteristics: free-running speed, stall torque, bearing resistance.  

PubMed

The measurement of performance characteristics of dental air turbine handpieces is of interest with respect to product comparisons, standards specifications and monitoring of bearing longevity in clinical service. Previously, however, bulky and expensive laboratory equipment was required. A portable test machine is described for determining three key characteristics of dental air-turbine handpieces: free-running speed, stall torque and bearing resistance. It relies on a special circuit design for performing a hardware integration of a force signal with respect to rotational position, independent of the rate at which the turbine is allowed to turn during both stall torque and bearing resistance measurements. Free-running speed without the introduction of any imbalance can be readily monitored. From the essential linear relationship between torque and speed, dynamic torque and, hence, power, can then be calculated. In order for these measurements to be performed routinely with the necessary precision of location on the test stage, a detailed procedure for ensuring proper gripping of the handpiece is described. The machine may be used to verify performance claims, standard compliance checks should this be established as appropriate, monitor deterioration with time and usage in the clinical environment and for laboratory investigation of design development. PMID:15765954

Darvell, Brain W; Dyson, J E

2005-01-01

460

Motor impairments related to brain injury timing in early hemiparesis Part II: abnormal upper extremity joint torque synergies  

PubMed Central

Background Extensive neuromotor development occurs early in human life, and the timing of brain injury may affect the resulting motor impairment. In part I of this paper series it was demonstrated that the distribution of weakness in the upper extremity depended on the timing of brain injury in individuals with childhood-onset hemiparesis. Objective The goal of this study was to characterize how timing of brain injury impacts joint torque synergies, or losses of independent joint control. Method Twenty-four individuals with hemiparesis were divided into three groups based on the timing of their injury: before birth (PRE-natal, n=8), around the time of birth (PERI-natal, n=8) and after 6 months of age (POST-natal, n=8). Individuals with hemiparesis, as well as 8 typically developing peers participated in maximal isometric shoulder, elbow, wrist, and finger torque generation tasks while their efforts were recorded by a multiple degree-of-freedom load cell. Motor output in 4 joints of the upper extremity were concurrently measured during 8 primary torque generation tasks to quantify joint torque synergies. Results There were a number of significant coupling patterns identified in individuals with hemiparesis that differed from the typically developing group. POST-natal differences were most noted in the coupling of shoulder abductors with elbow, wrist, and finger flexors, while the PRE-natal group demonstrated significant distal joint coupling with elbow flexion. Conclusion The torque synergies measured provide indirect evidence for the use of bulbospinal pathways in the POST-natal group, while those with earlier injury may utilize relatively preserved ipsilateral corticospinal motor pathways. PMID:23911972

Sukal-Moulton, Theresa; Krosschell, Kristin J.; Gaebler-Spira, Deborah J.; Dewald, Julius P.A.

2014-01-01