ROTATION PERIODS AND AGES OF SOLAR ANALOGS AND SOLAR TWINS REVEALED BY THE KEPLER MISSION

Energy Technology Data Exchange (ETDEWEB)

Do Nascimento Jr, J.-D.; Meibom, S. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); García, R. A.; Salabert, D.; Ceillier, T. [Laboratoire AIM, CEA/DSM,CNRS, Univ. Paris Diderot-IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Mathur, S. [Space Science Institute, 4750 Walnut Street Suite 205, Boulder CO 80301 (United States); Anthony, F.; Da Costa, J. S.; Castro, M. [Universidade Federal do Rio Grande do Norte, UFRN, Dep. de Física Teórica e Experimental, DFTE, CP 1641, 59072-970 Natal, RN (Brazil); Barnes, S. A., E-mail: jdonascimento@cfa.harvard.edu [Leibniz-Institute for Astrophysics, Potsdam D-14467 (Germany)

2014-08-01

A new sample of solar analogs and twin candidates has been constructed and studied, paying particular attention to their light curves from NASA's Kepler mission. This Letter aims to assess their evolutionary status, derive their rotation and ages, and identify those which are solar analogs or solar twin candidates. We separate out the subgiants that compose a large fraction of the asteroseismic sample, and which show an increase in the average rotation period as the stars ascend the subgiant branch. The rotation periods of the dwarfs, ranging from 6 to 30 days and averaging 19 days, allow us to assess their individual evolutionary states on the main sequence and to derive their ages using gyrochronology. These ages are found to be in agreement with a correlation coefficient of r = 0.79 with independent asteroseismic ages, where available. As a result of this investigation, we are able to identify 34 stars as solar analogs and 22 of them as solar twin candidates.

Rotation stability of high speed neutron time-of-flight mechanical chopper

International Nuclear Information System (INIS)

Habib, N.; Adib, M.

1998-01-01

A modified rotation stabilization system has been designed to maintain the stability of a neutron time-of-flight (TOF) mechanical chopper rates from 460 rpm to 16000 rpm. The main principle of the system is based on comparing the chopper's rotation period with the preselected one from a quartz timer. The result of comparison is used to control the current driver of the chopper's motor. A 600 Hz three phase generator controlled by a magnetic amplifier was used as a current driver. The stability of the chopper's rotation rate at 16000 rpm was 0.02%. An improved method precise time scale calibration of the TOF spectrometer is applied

FIRST OBSERVATIONAL SIGNATURE OF ROTATIONAL DECELERATION IN A MASSIVE, INTERMEDIATE-AGE STAR CLUSTER IN THE MAGELLANIC CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Wu, Xiaohan [School of Physics, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Li, Chengyuan; De Grijs, Richard [Kavli Institute for Astronomy and Astrophysics and Department of Astronomy, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Deng, Licai, E-mail: grijs@pku.edu.cn [Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China)

2016-07-20

While the extended main-sequence turnoffs (eMSTOs) found in almost all 1–2 Gyr old star clusters in the Magellanic Clouds are often explained by postulating extended star formation histories (SFHs), the tight subgiant branches (SGBs) seen in some clusters challenge this popular scenario. Puzzlingly, the SGB of the eMSTO cluster NGC 419 is significantly broader at bluer than at redder colors. We carefully assess and confirm the reality of this observational trend. If we would assume that the widths of the features in color–magnitude space were entirely owing to a range in stellar ages, the SFHs of the eMSTO stars and the blue SGB region would be significantly more prolonged than that of the red part of the SGB. This cannot be explained by assuming an internal age spread. We show that rotational deceleration of a population of rapidly rotating stars, a currently hotly debated alternative scenario, naturally explains the observed trend along the SGB. Our analysis shows that a “converging” SGB could be produced if the cluster is mostly composed of rapidly rotating stars that slow down over time owing to the conservation of angular momentum during their evolutionary expansion from main-sequence turnoff stars to red giants.

The relationship between age, rotator cuff integrity, and osseous microarchitecture of greater tuberosity: Where should we put anchor?

Science.gov (United States)

Kholinne, Erica; Lee, Hyun Joo; Kim, Sung Jung; Park, So Hyun; Jeon, In-Ho

2018-01-01

The aim of this study was to compare the microarchitecture of the greater tuberosity with or without rotator cuff tear and to obtain optimum location for anchor screw insertion for rotator cuff repair. Twenty-five humeral heads were harvested from 13 male cadavers of mean age 58.4 years, including 6 humeri with rotator cuff tear and 19 intact humeri. Six regions of interest (proximal, intermediate, and distal zones of the superficial and deep regions) were divided into the anterior (G1), middle (G2), and posterior (G3) areas of the greater tuberosity. Trabecular bone volume and cortical thickness were evaluated. Total trabecular bone volume was greater in subjects 50 years old but did not differ significantly in subjects with and without rotator cuff tear. Cortical thickness in both intact and torn rotator cuff groups was significantly greater in the proximal and intermediate zones than in the distal zone. Cortical thickness was related to anatomic location rather than age or cuff tear. The optimal location for anchor screw insertion during rotator cuff repair is either the proximal or intermediate region of the greater tuberosity. Age has more influence in terms of trabecular bone volume loss than rotator cuff integrity. Copyright © 2017. Production and hosting by Elsevier B.V.

Evaluation of the results from arthroscopic surgical treatment of rotator cuff injuries in patients aged 65 years and over

Directory of Open Access Journals (Sweden)

Alberto Naoki Miyazaki

2015-06-01

Full Text Available OBJECTIVES: To evaluate the results from arthroscopic surgical treatment of rotator cuff injuries in patients aged 65 years and over.METHODS: Between 1998 and 2009, 168 patients underwent operations. Five cases were excluded. The remaining 163 patients were stratified according to their age group: 65-69 years (49.1%, 70-74 (26.4% and 75 years and over (24.5%. Their mean age was 71 years (range: 65-83. There were 63 male patients (38.7%. The mean length of time with pain, from the onset of symptoms to the surgery, was 23 months (range: 2 days to 240 months. Sixty-two patients (38% reported histories of trauma and 26 (16% reported that their pain worsened through exertion.RESULTS: From the UCLA criteria, 80.4% of the results were excellent, 16% good, 1.8% fair and 1.8% poor. Complications occurred in 11%. The final clinical result did not show any correlation with age progression, injury size or tendons affected. However, there was a significant association (p < 0.001 between the presence of trauma and larger injuries. The length of time between the onset of symptoms and the surgical procedure had a significant relationship (p < 0.027 with the postoperative results: the longer this time was, the worse the results were.CONCLUSION: Arthroscopic treatment of rotator cuff injuries in patients aged 65 years and over presented excellent and good results in 96.4% of the cases, according to the UCLA assessment, with a low complication rate. Advanced age did not show any influence on the postoperative clinical evolution, but the earlier the surgical treatment was instituted, the better the results were.

Rotation in the dynamic factor modeling of multivariate stationary time series.

NARCIS (Netherlands)

Molenaar, P.C.M.; Nesselroade, J.R.

2001-01-01

A special rotation procedure is proposed for the exploratory dynamic factor model for stationary multivariate time series. The rotation procedure applies separately to each univariate component series of a q-variate latent factor series and transforms such a component, initially represented as white

Rates and timing of vertical-axis block rotations across the Sierra Nevada-Walker Lane transition in the Bodie Hills

Science.gov (United States)

Rood, D. H.; Herman, S.; Burbank, D.; Bogue, S.

2008-12-01

We use paleomagnetic data from Tertiary volcanic rocks to address the rates and timing of vertical-axis block rotation across the Sierra Nevada-Walker Lane transition in the Bodie Hills, California/Nevada. In zones of continental deformation, block rotations are an important mechanism for permanent stain accommodation, and thus may be crucial to testing geodetic block models and resolving geologic-geodetic slip discrepancies. In our study, data included in the paleomagetic site means are high quality AF demagnetization results (least squared fits that generally include 5-7 points with MAD values less than 1). Thermal demagnetization results match the AF directions, and both thermal demag and rockmag results indicate strong ChRM, mostly carried by single domain magnetite. The site means used to calculate the VGPs all have a95 values less than 10 (mostly 2-5) and include 6-11 sites each. Each site (and thus site mean) has a reasonably well-known structural correction. The VGP scatter values range from 12 to 16 degrees, indicating that they include appropriate secular variation. The mean declinations and 95 percent confidence limits for each VGP timeslice are statistically distinct from one another (71 ± 9, 39 ± 13, and 11 ± 11 degrees). The slope of a linear regression fit to the age versus declination data gives a rate of vertical axis block rotation of approximately 3-4 degrees/Myr. Fitting two separate lines to the age vs. declination data would indicate an increase in the rates of rotation since ~10 Ma. Two possible interpretations of the data are: (1) the rotations began during or before the Middle Miocene, or (2) rates of rotation were high initially (e.g. ~10 Ma) and decelerated until the Pliocene. These data have implications for the (1) timing and spatial extent of distributed strain accumulation related to the initiation of the San Andreas Fault-Eastern California Shear Zone-Walker Lane transform plate boundary, (2) transfer of transform plate boundary

Rotation in the Dynamic Factor Modeling of Multivariate Stationary Time Series.

Science.gov (United States)

Molenaar, Peter C. M.; Nesselroade, John R.

2001-01-01

Proposes a special rotation procedure for the exploratory dynamic factor model for stationary multivariate time series. The rotation procedure applies separately to each univariate component series of a q-variate latent factor series and transforms such a component, initially represented as white noise, into a univariate moving-average.…

Modal Analysis in Periodic, Time-Varying Systems with emphasis to the Coupling between Flexible Rotating Beams and Non-Rotating Flexible Structures

DEFF Research Database (Denmark)

Saracho, C. M.; Santos, Ilmar

2003-01-01

The analysis of dynamical response of a system built by a non-rotating structure coupled to flexible rotating beams is the purpose of this work. The effect of rotational speed upon the beam natural frequencies is well-known, so that an increase in the angular speeds leads to an increase in beam...... natural frequencies, the so-called centrifugal stiffening. The equations of motion of such a global system present matrices with time-depending coefficients, which vary periodically with the angular rotor speed, and introduce parametric vibrations into the system response. The principles of modal analysis...... for time-invariant linear systems are expanded to investigate time-varying systems. Concepts as eigenvalues and eigenvectors, which in this special case are also time-varying, are used to analyse the dynamical response of global system. The time-varying frequencies and modes are also illustrated....

Gyrochronology of Low-mass Stars - Age-Rotation-Activity Relations for Young M Dwarfs

Science.gov (United States)

Kidder, Benjamin; Shkolnik, E.; Skiff, B.

2014-01-01

New rotation periods for 34 young understanding of the underlying mechanisms that govern angular momentum evolution. Yet, on average, the data still support the predicted trends for spin-up during contraction and spin-down on the main sequence, with the turnover occurring at around 150 Myr for early Ms. This suggests that rotation period distributions can be helpful in evaluating the ages of coeval groups of stars. Many thanks to the National Science Foundation for their support through the Research Experience for Undergraduates Grant AST- 1004107.

Regulating forest rotation to increase CO{sub 2} sequestration

Energy Technology Data Exchange (ETDEWEB)

Gong, P.; Kristroem, B.

1999-06-01

Previous studies have shown that the optimal forest rotation age increases considerably if the benefits of CO{sub 2} sequestration are included in rotation decisions. While these studies provide some guidelines for managing public forests, private forest owners may not choose the socially optimal rotation age. This paper discusses a regulation measure to increase CO{sub 2} sequestration in privately owned forests. The regulation problem is treated as a sequential game, where the regulator chooses a subsidy scheme and forest owners respond by changing rotation ages. A private forest owner receives a subsidy at the time of harvesting if he/she changes the rotation age towards the socially optimal one. The subsidy is proportional to the associated change in timber yield. The forest owner`s objective is to maximize the net present value of after-tax timber production profits and subsidies. The regulator`s decision problem is to find the subsidy rate that maximizes the net benefits of implementing the policy (the net of increased CO{sub 2} sequestration benefits, subsidy costs, and changes in forestry taxation income). Empirical results for Swedish examples show that the optimal subsidy rate is sensitive to the marginal benefit of CO{sub 2} sequestration, the social discount rate, and site quality. The optimal subsidy rate is found to be significantly lower than the marginal benefit of CO{sub 2} sequestration. With the proposed subsidy scheme, private forest owners will choose rotation ages longer than the Faustmann rotation, but significantly shorter than the socially optimal rotation age 21 refs, 6 tabs. Arbetsrapport 272

Time-scales of stellar rotational variability and starspot diagnostics

Science.gov (United States)

Arkhypov, Oleksiy V.; Khodachenko, Maxim L.; Lammer, Helmut; Güdel, Manuel; Lüftinger, Teresa; Johnstone, Colin P.

2018-01-01

The difference in stability of starspot distribution on the global and hemispherical scales is studied in the rotational spot variability of 1998 main-sequence stars observed by Kepler mission. It is found that the largest patterns are much more stable than smaller ones for cool, slow rotators, whereas the difference is less pronounced for hotter stars and/or faster rotators. This distinction is interpreted in terms of two mechanisms: (1) the diffusive decay of long-living spots in activity complexes of stars with saturated magnetic dynamos, and (2) the spot emergence, which is modulated by gigantic turbulent flows in convection zones of stars with a weaker magnetism. This opens a way for investigation of stellar deep convection, which is yet inaccessible for asteroseismology. Moreover, a subdiffusion in stellar photospheres was revealed from observations for the first time. A diagnostic diagram was proposed that allows differentiation and selection of stars for more detailed studies of these phenomena.

Time-odd mean fields in covariant density functional theory: Rotating systems

International Nuclear Information System (INIS)

Afanasjev, A. V.; Abusara, H.

2010-01-01

Time-odd mean fields (nuclear magnetism) and their impact on physical observables in rotating nuclei are studied in the framework of covariant density functional theory (CDFT). It is shown that they have profound effect on the dynamic and kinematic moments of inertia. Particle number, configuration, and rotational frequency dependencies of their impact on the moments of inertia have been analyzed in a systematic way. Nuclear magnetism can also considerably modify the band crossing features such as crossing frequencies and the properties of the kinematic and dynamic moments of inertia in the band crossing region. The impact of time-odd mean fields on the moments of inertia in the regions away from band crossing only weakly depends on the relativistic mean-field parametrization, reflecting good localization of the properties of time-odd mean fields in CDFT. The moments of inertia of normal-deformed nuclei considerably deviate from the rigid-body value. On the contrary, superdeformed and hyperdeformed nuclei have the moments of inertia which are close to rigid-body value. The structure of the currents in rotating frame, their microscopic origin, and the relations to the moments of inertia have been systematically analyzed. The phenomenon of signature separation in odd-odd nuclei, induced by time-odd mean fields, has been analyzed in detail.

Hybrid state-space time integration of rotating beams

DEFF Research Database (Denmark)

Krenk, Steen; Nielsen, Martin Bjerre

2012-01-01

An efficient time integration algorithm for the dynamic equations of flexible beams in a rotating frame of reference is presented. The equations of motion are formulated in a hybrid state-space format in terms of local displacements and local components of the absolute velocity. With inspiration...... of the system rotation enter via global operations with the angular velocity vector. The algorithm is based on an integrated form of the equations of motion with energy and momentum conserving properties, if a kinematically consistent non-linear formulation is used. A consistent monotonic scheme for algorithmic...... energy dissipation in terms of local displacements and velocities, typical of structural vibrations, is developed and implemented in the form of forward weighting of appropriate mean value terms in the algorithm. The algorithm is implemented for a beam theory with consistent quadratic non...

A new approach to defining rotation ages on the basis of productive and technological aspects. Application to natural Pinus sylvestris L. stands in Central Spain

International Nuclear Information System (INIS)

Rojo-Alboreca, A.; García-Villabrille, J.D.; Corral-Rivas, J.J.; Alía, R.; Montero, G.

2017-01-01

Aim of study: To propose a new approach to defining rotation ages on the basis of productive and technological aspects and to present an example of application of the methodology to natural Pinus sylvestris stands in relation to silvicultural treatment (light or heavy thinning) and site index. Area of study: Central Spain. Material and methods: We assumed that the price per m3 of logwood suitable for veneer is four times higher than logwood not apt for veneer. Considering the yield distribution for different technological and commercial classes, a model of diameter distributions and yield tables, the variation in an average price index for different age classes, site indexes and silvicultural treatments was calculated. The age at which the price index rises by less than 3%, the proportion of trees with d.b.h. higher than 40 cm, and other aspects such as the possible presence of fungal decay in old-growth stands were also taken into account to establish three criteria for defining rotation ages. Main results: The proposed methodology generates a wide range of rotation ages between 100 and 140 years for lightly thinned stands, and between 90 and 140 years for heavily thinned stands, depending on the site index. Research highlights: The proposed approach is based on technological and productive criteria, with the limitations imposed by sanitary risks. The methodology can be applied to generate rotation ages in relation to different site indexes and silvicultural treatments, provided that the timber market prices and the yield distribution for different technological and commercial classes are known, and that a model of diameter distributions and yield tables are available.

A new approach to defining rotation ages on the basis of productive and technological aspects. Application to natural Pinus sylvestris L. stands in Central Spain

Energy Technology Data Exchange (ETDEWEB)

Rojo-Alboreca, A.; García-Villabrille, J.D.; Corral-Rivas, J.J.; Alía, R.; Montero, G.

2017-11-01

Aim of study: To propose a new approach to defining rotation ages on the basis of productive and technological aspects and to present an example of application of the methodology to natural Pinus sylvestris stands in relation to silvicultural treatment (light or heavy thinning) and site index. Area of study: Central Spain. Material and methods: We assumed that the price per m3 of logwood suitable for veneer is four times higher than logwood not apt for veneer. Considering the yield distribution for different technological and commercial classes, a model of diameter distributions and yield tables, the variation in an average price index for different age classes, site indexes and silvicultural treatments was calculated. The age at which the price index rises by less than 3%, the proportion of trees with d.b.h. higher than 40 cm, and other aspects such as the possible presence of fungal decay in old-growth stands were also taken into account to establish three criteria for defining rotation ages. Main results: The proposed methodology generates a wide range of rotation ages between 100 and 140 years for lightly thinned stands, and between 90 and 140 years for heavily thinned stands, depending on the site index. Research highlights: The proposed approach is based on technological and productive criteria, with the limitations imposed by sanitary risks. The methodology can be applied to generate rotation ages in relation to different site indexes and silvicultural treatments, provided that the timber market prices and the yield distribution for different technological and commercial classes are known, and that a model of diameter distributions and yield tables are available.

Rotator cuff injury in patients over the age of 65 years: evaluation of function, integrity and strength

Directory of Open Access Journals (Sweden)

Marco Antonio de Castro Veado

2015-06-01

Full Text Available OBJECTIVE: To retrospectively evaluate the results from patients who underwent arthroscopic treatment for rotator cuff injuries, among those aged over 65 years, observing integrity, function and strength.METHODS: Thirty-five shoulders were operated between July 2005 and July 2010, and 28 shoulders were re-evaluated regarding elevation strength and external rotation, using a digital dynamometer. Integrity was evaluated by means of ultrasound examinations. The patients, whose mean age was 70.54 years (ranging from 65 to 82 years, were followed up for a minimum of 26 months and mean of 51.18 months (ranging from 26 to 82 months. To evaluate function, the UCLA score, the Simple Shoulder Test (SST and a visual analog scale (VAS for pain were used.RESULTS: In analyzing the ultrasound scans, it was observed that the integrity of the rotator cuff was maintained in 75% of the cases at the end of the follow-up, along with the improvement in the UCLA score, which evolved from 17.46 to 32.39, i.e. excellent and good results in 89.28%. The mean SST and VAS indices were 9.86 and 1.5 respectively.CONCLUSION: Arthroscopic surgery to repair rotator cuff injuries in patients over the age of 65 years leads to improved function and pain relief, with maintenance of the integrity of the repair. The data on muscle strength were inconclusive.

Glenohumeral joint translation and muscle activity in patients with symptomatic rotator cuff pathology: An ultrasonographic and electromyographic study with age-matched controls.

Science.gov (United States)

Rathi, Sangeeta; Taylor, Nicholas F; Soo, Brendan; Green, Rodney A

2018-03-02

To determine whether patients with symptomatic rotator cuff pathology had more glenohumeral joint translation and different patterns of rotator cuff muscle activity compared to controls. Repeated measurements of glenohumeral translation and muscle activity in two positions and six testing conditions in two groups. Twenty participants with a symptomatic and diagnosed rotator cuff tear and 20 age, and gender matched controls were included. Neuromuscular activity was tested by inserting intramuscular electrodes in the rotator cuff muscles. Anterior and posterior glenohumeral translations were measured using real time ultrasound in testing conditions (with and without translation force, with and without isometric internal and external rotation), in two positions (shoulder neutral, 90° of abduction) and two force directions (anterior, posterior). Symptomatic pathology group demonstrated increased passive glenohumeral translation with posterior translation force (protator cuff muscle contraction in the pathology group limited joint translation in a similar manner to the control group, but they did not show the normal direction specific pattern in the neutral posterior position (protator cuff still controlled glenohumeral translation. These results highlight the need to consider joint translation in the assessment and management of patients with rotator cuff injury. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Counterclockwise and Clockwise Rotation of QRS Transitional Zone: Prospective Correlates of Change and Time-Varying Associations With Cardiovascular Outcomes.

Science.gov (United States)

Patel, Siddharth; Kwak, Lucia; Agarwal, Sunil K; Tereshchenko, Larisa G; Coresh, Josef; Soliman, Elsayed Z; Matsushita, Kunihiro

2017-11-03

A few studies have recently reported clockwise and counterclockwise rotations of QRS transition zone as predictors of mortality. However, their prospective correlates and associations with individual cardiovascular disease (CVD) outcomes are yet to be investigated. Among 13 567 ARIC (Atherosclerosis Risk in Communities) study participants aged 45 to 64 years, we studied key correlates of changes in the status of clockwise and counterclockwise rotation over time as well as the association of rotation status with incidence of coronary heart disease (2408 events), heart failure (2196 events), stroke (991 events), composite CVD (4124 events), 898 CVD deaths, and 3469 non-CVD deaths over 23 years of follow-up. At baseline, counterclockwise rotation was most prevalent (52.9%), followed by no (40.5%) and clockwise (6.6%) rotation. Of patients with no rotation, 57.9% experienced counterclockwise or clockwise rotation during follow-up, with diabetes mellitus and black race significantly predicting clockwise and counterclockwise conversion, respectively. Clockwise rotation was significantly associated with higher risk of heart failure (hazard ratio, 1.20; 95% confidence interval [CI], 1.02-1.41) and non-CVD death (hazard ratio, 1.28; 95% CI, 1.12-1.46) after adjusting for potential confounders including other ECG parameters. On the contrary, counterclockwise rotation was significantly related to lower risk of composite CVD (hazard ratio, 0.93; 95% CI, 0.87-0.99]), CVD mortality (hazard ratio, 0.76; 95% CI, 0.65-0.88), and non-CVD deaths (hazard ratio, 0.92; 95% CI, 0.85-0.99 [borderline significance with heart failure]). Counterclockwise rotation, the most prevalent QRS transition zone pattern, demonstrated the lowest risk of CVD and mortality, whereas clockwise rotation was associated with the highest risk of heart failure and non-CVD mortality. These results have implications on how to interpret QRS transition zone rotation when ECG was recorded. © 2017 The Authors

Cystic Lesions in the Greater Tuberosity of the Humerus: The Relation to Rotator Cuff Tears and Age

International Nuclear Information System (INIS)

Kim, Gang Deuk; Oh, Jung Taek

2008-01-01

This study was designed to investigate the location of cystic lesions in the greater tuberosity of the humerus and the relationship to rotator cuff tears and age. A total of 78 patients (age range, 19-82 years; mean age, 51 years) who underwent arthroscopy or open surgery after MR arthrography (MRA) for a painful shoulder were enrolled in the study. The location of the cystic lesions were classified as 'A' for a supraspinatus insertion site, as 'C' for an infraspinatus insertion site, as 'B' for both a supraspinatus and infraspinatus insertion site, as 'BG' for a site posterior to the bicipital groove and as 'P' for a site at the bare area of the humeral head. The location of cystic lesions and supraspinatus and infraspinatus tears were evaluated on MRA. Statistical analyses used the chi-squared test and logistic regression. 'BG' and 'A' cystic lesions were related to the presence of a supraspinatus tear, 'C' cystic lesions were related to the presence of an infraspinatus tear and 'B' cystic lesions were related to the presence of both supraspinatus and infraspinatus tears (p < 0.05). 'P' cystic lesions were not related to the presence of rotator cuff tears. The incidence of cystic lesions increased with age, but with no statistical correlation. Cystic lesions at the supraspinatus and infraspinatus insertion sites are useful to predict the presence of a rotator cuff tear, but cystic lesions were not age related

The Living with a Red Dwarf / Goldiloks Program: The Activity-Rotation-Age Relationships of M and K Dwarfs

Science.gov (United States)

Engle, Scott; Guinan, Edward Francis

2018-01-01

Over the past several years, the database of M dwarfs with determined ages has continually expanded, allowing us to furnish Activity-Rotation-Age Relationships as part of the Living with a Red Dwarf program. We have now begun to expand this successful program to also cover K dwarfs - the Goldiloks program. Both M and K dwarfs suffer from the same limitation - due to their long lifetimes and very slow nuclear evolution, the best method for determining ages for a large number of M and K dwarf targets is through “magnetic tracers” such as X-UV activity levels and stellar rotation rates. We report on the current results of our relationships: deriving photometric rotation rates; gathering X-UV measures with HST, IUE Chandra and XMM (both proposed by us, and archival); and assessing their impacts on our understanding of the evolutions and habitability of these stellar types.We gratefully acknowledge the support from NSF/RUI Grant AST 1009903, Chandra Grant GO-13200633, HST Grants GO-12124X and GO-13020X.

Preferred 11 different job rotation types in automotive company and their effects on productivity, quality and musculoskeletal disorders: comparison between subjective and actual scores by workers' age.

Science.gov (United States)

Jeon, In Sik; Jeong, Byung Yong; Jeong, Ji Hyun

2016-10-01

This study investigates workers' favoured rotation types by their age and compares means between subjective and actual scores on productivity, quality and musculoskeletal disorders (MSDs). The subjects of research were 422 assembly line units in Hyundai Motor Company. The survey of 422 units focused on the workers' preference for 11 different rotation types and subjective scores for each type's perceived benefits, both by the workers' age. Then, actual scores on production-related indices were traced over a five-year period. The results suggest that different rotation types lead to different results in productivity, product quality and MSDs. Workers tend to perceive job rotation as a helpful method to enhance satisfaction, productivity and product quality more so than the actual production data suggests. Job rotation was especially effective in preventing MSDs for workers aged under 45, while its effects were not clear for the workers aged 45 years or older. Practitioner's Summary: This research presents appropriate rotation type for different age groups. Taking workers' age into account, administrators can use the paper's outcomes to select and implement the suitable rotation type to attain specific goals such as enhancing productivity, improving product quality or reducing MSDs.

Cystic Lesions in the Greater Tuberosity of the Humerus: The Relation to Rotator Cuff Tears and Age

Energy Technology Data Exchange (ETDEWEB)

Kim, Gang Deuk; Oh, Jung Taek [Wonkwang University Hospital, Iksan (Korea, Republic of)

2008-12-15

This study was designed to investigate the location of cystic lesions in the greater tuberosity of the humerus and the relationship to rotator cuff tears and age. A total of 78 patients (age range, 19-82 years; mean age, 51 years) who underwent arthroscopy or open surgery after MR arthrography (MRA) for a painful shoulder were enrolled in the study. The location of the cystic lesions were classified as 'A' for a supraspinatus insertion site, as 'C' for an infraspinatus insertion site, as 'B' for both a supraspinatus and infraspinatus insertion site, as 'BG' for a site posterior to the bicipital groove and as 'P' for a site at the bare area of the humeral head. The location of cystic lesions and supraspinatus and infraspinatus tears were evaluated on MRA. Statistical analyses used the chi-squared test and logistic regression. 'BG' and 'A' cystic lesions were related to the presence of a supraspinatus tear, 'C' cystic lesions were related to the presence of an infraspinatus tear and 'B' cystic lesions were related to the presence of both supraspinatus and infraspinatus tears (p < 0.05). 'P' cystic lesions were not related to the presence of rotator cuff tears. The incidence of cystic lesions increased with age, but with no statistical correlation. Cystic lesions at the supraspinatus and infraspinatus insertion sites are useful to predict the presence of a rotator cuff tear, but cystic lesions were not age related

The role of rotational hand movements and general motor ability in children’s mental rotation performance

Directory of Open Access Journals (Sweden)

Petra eJansen

2015-07-01

Full Text Available Mental rotation of visual images of body parts and abstract shapes can be influenced by simultaneous motor activity. Children in particular seem to have a strong coupling between motor and cognitive processes. We investigated the influence of a rotational hand movement performed by rotating a knob on mental rotation performance in primary school-age children (N= 83; Age range: 7.0-8.3 and 9.0-10.11 years. In addition, we assessed the role of motor ability in this relationship. Boys in the 7-8-year-old group were faster when mentally and manually rotating in the same direction than in the opposite direction. For girls and older children this effect was not found. A positive relationship was found between motor ability and accuracy on the mental rotation task: stronger motor ability related to improved mental rotation performance. In both age groups, children with more advanced motor abilities were more likely to adopt motor processes to solve mental rotation tasks if the mental rotation task was primed by a motor task. Our evidence supports the idea that an overlap between motor and visual cognitive processes in children is influenced by motor ability.

On the Rotating and Oscillating strings in $(AdS_3\\times S^3)_{\\varkappa}$

CERN Document Server

Banerjee, Aritra

2014-01-01

We study rigidly rotating strings in the $\\varkappa$-deformed $AdS_3 \\times S^3$ background. We find out two classes of solutions corresponding to the giant magnon and single spike solutions of the string rotating is two $S^2_{\\varkappa}$ subspace of rotations reduced along two different isometries. We verify that the dispersion relations reduce to the well known relation in the $\\varkappa\\rightarrow 0$ limit. We further study some oscillating string solutions in the $S^3_{\\varkappa}$ subspace.

RACE-OC project: Rotation and variability of young stellar associations within 100 pc

Science.gov (United States)

Messina, S.; Desidera, S.; Turatto, M.; Lanzafame, A. C.; Guinan, E. F.

2010-09-01

Context. Examining the angular momentum of stars and its interplay with their magnetic fields represent a promising way to probe the stellar internal structure and evolution of low-mass stars. Aims: We attempt to determine the rotational and magnetic-related activity properties of stars at different stages of evolution.We focused our attention primarily on members of clusters and young stellar associations of known ages. In this study, our targets are 6 young loose stellar associations within 100 pc and with ages in the range 8-70 Myr: TW Hydrae (~8 Myr), β Pictoris (~10 Myr), Tucana/Horologium, Columba, Carina (~30 Myr), and AB Doradus (~70 Myr). Additional rotational data for α Persei and the Pleiades from the literature are also considered. Methods: Rotational periods of stars exhibiting rotational modulation due to photospheric magnetic activity (i.e., starspots) were determined by applying the Lomb-Scargle periodogram technique to photometric time-series data obtained by the All Sky Automated Survey (ASAS). The magnetic activity level was derived from the amplitude of the V lightcurves. The statistical significance of the rotational evolution at different ages was inferred by applying a two-sided Kolmogorov-Smirnov test to subsequent age-bins. Results: We detected the rotational modulation and measured the rotation periods of 93 stars for the first time, and confirmed the periods of 41 stars already known from the literature. For an additional 10 stars, we revised the period determinations by other authors. The sample was augmented with periods of 21 additional stars retrieved from the literature. In this way, for the first time we were able to determine the largest set of rotation periods at ages of ~8, ~10 and ~30 Myr, as well as increase by 150% the number of known periodic members of AB Dor. Conclusions: The analysis of the rotation periods in young stellar associations, supplemented by Orion Nebula Cluster (ONC) and NGC 2264 data from the literature

Robotic real-time translational and rotational head motion correction during frameless stereotactic radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Liu, Xinmin; Belcher, Andrew H.; Grelewicz, Zachary; Wiersma, Rodney D., E-mail: rwiersma@uchicago.edu [Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States)

2015-06-15

Purpose: To develop a control system to correct both translational and rotational head motion deviations in real-time during frameless stereotactic radiosurgery (SRS). Methods: A novel feedback control with a feed-forward algorithm was utilized to correct for the coupling of translation and rotation present in serial kinematic robotic systems. Input parameters for the algorithm include the real-time 6DOF target position, the frame pitch pivot point to target distance constant, and the translational and angular Linac beam off (gating) tolerance constants for patient safety. Testing of the algorithm was done using a 4D (XY Z + pitch) robotic stage, an infrared head position sensing unit and a control computer. The measured head position signal was processed and a resulting command was sent to the interface of a four-axis motor controller, through which four stepper motors were driven to perform motion compensation. Results: The control of the translation of a brain target was decoupled with the control of the rotation. For a phantom study, the corrected position was within a translational displacement of 0.35 mm and a pitch displacement of 0.15° 100% of the time. For a volunteer study, the corrected position was within displacements of 0.4 mm and 0.2° over 98.5% of the time, while it was 10.7% without correction. Conclusions: The authors report a control design approach for both translational and rotational head motion correction. The experiments demonstrated that control performance of the 4D robotic stage meets the submillimeter and subdegree accuracy required by SRS.

Robotic real-time translational and rotational head motion correction during frameless stereotactic radiosurgery

International Nuclear Information System (INIS)

Liu, Xinmin; Belcher, Andrew H.; Grelewicz, Zachary; Wiersma, Rodney D.

2015-01-01

Purpose: To develop a control system to correct both translational and rotational head motion deviations in real-time during frameless stereotactic radiosurgery (SRS). Methods: A novel feedback control with a feed-forward algorithm was utilized to correct for the coupling of translation and rotation present in serial kinematic robotic systems. Input parameters for the algorithm include the real-time 6DOF target position, the frame pitch pivot point to target distance constant, and the translational and angular Linac beam off (gating) tolerance constants for patient safety. Testing of the algorithm was done using a 4D (XY Z + pitch) robotic stage, an infrared head position sensing unit and a control computer. The measured head position signal was processed and a resulting command was sent to the interface of a four-axis motor controller, through which four stepper motors were driven to perform motion compensation. Results: The control of the translation of a brain target was decoupled with the control of the rotation. For a phantom study, the corrected position was within a translational displacement of 0.35 mm and a pitch displacement of 0.15° 100% of the time. For a volunteer study, the corrected position was within displacements of 0.4 mm and 0.2° over 98.5% of the time, while it was 10.7% without correction. Conclusions: The authors report a control design approach for both translational and rotational head motion correction. The experiments demonstrated that control performance of the 4D robotic stage meets the submillimeter and subdegree accuracy required by SRS

Factors predicting rotator cuff retears: an analysis of 1000 consecutive rotator cuff repairs.

Science.gov (United States)

Le, Brian T N; Wu, Xiao L; Lam, Patrick H; Murrell, George A C

2014-05-01

The rate of retears after rotator cuff repair varies from 11% to 94%. A retear is associated with poorer subjective and objective clinical outcomes than intact repair. This study was designed to determine which preoperative and/or intraoperative factors held the greatest association with retears after arthroscopic rotator cuff repair. Cohort study; Level of evidence, 3. This study retrospectively evaluated 1000 consecutive patients who had undergone a primary rotator cuff repair by a single surgeon using an arthroscopic inverted-mattress knotless technique and who had undergone an ultrasound evaluation 6 months after surgery to assess repair integrity. Exclusion criteria included previous rotator cuff repair on the same shoulder, incomplete repair, and repair using a synthetic polytetrafluoroethylene patch. All patients had completed the modified L'Insalata Questionnaire and underwent a clinical examination before surgery. Measurements of tear size, tear thickness, associated shoulder injury, tissue quality, and tendon mobility were recorded intraoperatively. The overall retear rate at 6 months after surgery was 17%. Retears occurred in 27% of full-thickness tears and 5% of partial-thickness tears (P < .0001). The best independent predictors of retears were anteroposterior tear length (correlation coefficient r = 0.41, P < .0001), tear size area (r = 0.40, P < .0001), mediolateral tear length (r = 0.34, P < .0001), tear thickness (r = 0.29, P < .0001), age at surgery (r = 0.27, P < .0001), and operative time (r = 0.18, P < .0001). These factors produced a predictive model for retears: logit P = (0.039 × age at surgery in years) + (0.027 × tear thickness in %) + (1 × anteroposterior tear length in cm) + (0.76 × mediolateral tear length in cm) - (0.17 × tear size area in cm(2)) + (0.018 × operative time in minutes) -9.7. Logit P can be transformed into P, which is the chance of retears at 6 months after surgery. A rotator cuff retear is a multifactorial process

Rotational displacement skills in rhesus macaques (Macaca mulatta).

Science.gov (United States)

Hughes, Kelly D; Santos, Laurie R

2012-11-01

Rotational displacement tasks, in which participants must track an object at a hiding location within an array while the array rotates, exhibit a puzzling developmental pattern in humans. Human children take an unusually long time to master this task and tend to solve rotational problems through the use of nongeometric features or landmarks as opposed to other kinds of spatial cues. We investigated whether these developmental characteristics are unique to humans by testing rotational displacement skills in a monkey species, the rhesus macaque (Macaca mulatta), using a looking-time method. Monkeys first saw food hidden in two differently colored boxes within an array. The array was then rotated 180° and the boxes reopened to reveal the food in an expected or unexpected location. Our first two experiments explored the developmental time-course of performance on this rotational displacement task. We found that adult macaques looked longer at the unexpected event, but such performance was not mirrored in younger-aged macaques. In a third study, we systematically varied featural information and visible access to the array to investigate which strategies adult macaques used in solving rotational displacements. Our results show that adult macaques need both sets of information to solve the task. Taken together, these results suggest both similarities and differences in mechanisms by which human and nonhuman primates develop this spatial skill.

Paleomagnetic constraints on the timing and distribution of Cenozoic rotations in Central and Eastern Anatolia

Science.gov (United States)

Gürer, Derya; van Hinsbergen, Douwe J. J.; Özkaptan, Murat; Creton, Iverna; Koymans, Mathijs R.; Cascella, Antonio; Langereis, Cornelis G.

2018-03-01

To quantitatively reconstruct the kinematic evolution of Central and Eastern Anatolia within the framework of Neotethyan subduction accommodating Africa-Eurasia convergence, we paleomagnetically assess the timing and amount of vertical axis rotations across the Ulukışla and Sivas regions. We show paleomagnetic results from ˜ 30 localities identifying a coherent rotation of a SE Anatolian rotating block comprised of the southern Kırşehir Block, the Ulukışla Basin, the Central and Eastern Taurides, and the southern part of the Sivas Basin. Using our new and published results, we compute an apparent polar wander path (APWP) for this block since the Late Cretaceous, showing that it experienced a ˜ 30-35° counterclockwise vertical axis rotation since the Oligocene time relative to Eurasia. Sediments in the northern Sivas region show clockwise rotations. We use the rotation patterns together with known fault zones to argue that the counterclockwise-rotating domain of south-central Anatolia was bounded by the Savcılı Thrust Zone and Deliler-Tecer Fault Zone in the north and by the African-Arabian trench in the south, the western boundary of which is poorly constrained and requires future study. Our new paleomagnetic constraints provide a key ingredient for future kinematic restorations of the Anatolian tectonic collage.

Paleomagnetic constraints on the timing and distribution of Cenozoic rotations in Central and Eastern Anatolia

Directory of Open Access Journals (Sweden)

D. Gürer

2018-03-01

Full Text Available To quantitatively reconstruct the kinematic evolution of Central and Eastern Anatolia within the framework of Neotethyan subduction accommodating Africa–Eurasia convergence, we paleomagnetically assess the timing and amount of vertical axis rotations across the Ulukışla and Sivas regions. We show paleomagnetic results from ∼ 30 localities identifying a coherent rotation of a SE Anatolian rotating block comprised of the southern Kırşehir Block, the Ulukışla Basin, the Central and Eastern Taurides, and the southern part of the Sivas Basin. Using our new and published results, we compute an apparent polar wander path (APWP for this block since the Late Cretaceous, showing that it experienced a ∼ 30–35° counterclockwise vertical axis rotation since the Oligocene time relative to Eurasia. Sediments in the northern Sivas region show clockwise rotations. We use the rotation patterns together with known fault zones to argue that the counterclockwise-rotating domain of south-central Anatolia was bounded by the Savcılı Thrust Zone and Deliler–Tecer Fault Zone in the north and by the African–Arabian trench in the south, the western boundary of which is poorly constrained and requires future study. Our new paleomagnetic constraints provide a key ingredient for future kinematic restorations of the Anatolian tectonic collage.

Late-time dynamics of rapidly rotating black holes

International Nuclear Information System (INIS)

Glampedakis, K.; Andersson, N.

2001-01-01

We study the late-time behaviour of a dynamically perturbed rapidly rotating black hole. Considering an extreme Kerr black hole, we show that the large number of virtually undamped quasinormal modes (that exist for nonzero values of the azimuthal eigenvalue m) combine in such a way that the field (as observed at infinity) oscillates with an amplitude that decays as 1/t at late times. For a near extreme black hole, these modes, collectively, give rise to an exponentially decaying field which, however, is considerably 'long-lived'. Our analytic results are verified using numerical time-evolutions of the Teukolsky equation. Moreover, we argue that the physical mechanism behind the observed behaviour is the presence of a 'superradiance resonance cavity' immediately outside the black hole. We present this new feature in detail, and discuss whether it may be relevant for astrophysical black holes. (author)

Excitation of Earth Rotation Variations "Observed" by Time-Variable Gravity

Science.gov (United States)

Chao, Ben F.; Cox, C. M.

2005-01-01

Time variable gravity measurements have been made over the past two decades using the space geodetic technique of satellite laser ranging, and more recently by the GRACE satellite mission with improved spatial resolutions. The degree-2 harmonic components of the time-variable gravity contain important information about the Earth s length-of-day and polar motion excitation functions, in a way independent to the traditional "direct" Earth rotation measurements made by, for example, the very-long-baseline interferometry and GPS. In particular, the (degree=2, order= 1) components give the mass term of the polar motion excitation; the (2,O) component, under certain mass conservation conditions, gives the mass term of the length-of-day excitation. Combining these with yet another independent source of angular momentum estimation calculated from global geophysical fluid models (for example the atmospheric angular momentum, in both mass and motion terms), in principle can lead to new insights into the dynamics, particularly the role or the lack thereof of the cores, in the excitation processes of the Earth rotation variations.

Rotator cuff tendon connections with the rotator cable.

Science.gov (United States)

Rahu, Madis; Kolts, Ivo; Põldoja, Elle; Kask, Kristo

2017-07-01

The literature currently contains no descriptions of the rotator cuff tendons, which also describes in relation to the presence and characteristics of the rotator cable (anatomically known as the ligamentum semicirculare humeri). The aim of the current study was to elucidate the detailed anatomy of the rotator cuff tendons in association with the rotator cable. Anatomic dissection was performed on 21 fresh-frozen shoulder specimens with an average age of 68 years. The rotator cuff tendons were dissected from each other and from the glenohumeral joint capsule, and the superior glenohumeral, coracohumeral, coracoglenoidal and semicircular (rotator cable) ligaments were dissected. Dissection was performed layer by layer and from the bursal side to the joint. All ligaments and tendons were dissected in fine detail. The rotator cable was found in all specimens. It was tightly connected to the supraspinatus (SSP) tendon, which was partly covered by the infraspinatus (ISP) tendon. The posterior insertion area of the rotator cable was located in the region between the middle and inferior facets of the greater tubercle of the humerus insertion areas for the teres minor (TM), and ISP tendons were also present and fibres from the SSP extended through the rotator cable to those areas. The connection between the rotator cable and rotator cuff tendons is tight and confirms the suspension bridge theory for rotator cuff tears in most areas between the SSP tendons and rotator cable. In its posterior insertion area, the rotator cable is a connecting structure between the TM, ISP and SSP tendons. These findings might explain why some patients with relatively large rotator cuff tears can maintain seamless shoulder function.

Numerical simulation in three space dimensions of time-dependent thermal convection in a rotating fluid

International Nuclear Information System (INIS)

Hathaway, D.H.; Somerville, R.C.J.; National Solar Observatory, Sunspot, NM; California Univ., La Jolla)

1985-01-01

Three-dimensional, time-dependent convection in a plane layer of fluid, uniformly heated from below and subject to vertical shear and to rotation about an axis tilted from the vertical, was simulated by the numerical solution of the Boussinesq equations, including all Coriolis terms. Rotation about a vertical axis produces smaller convection cells with diminished heat fluxes and considerable vorticity. When the rotation axis is tilted from the vertical to represent tropical latitudes, the convection cells become elongated in a N-S direction. Imposed flows with constant vertical shear produce convective rolls aligned with the mean flow. When the rotation vector is tilted from the vertical, the competing effects due to rotation and shear can stabilize the convective motions. 15 references

A MODEL OF MAGNETIC BRAKING OF SOLAR ROTATION THAT SATISFIES OBSERVATIONAL CONSTRAINTS

International Nuclear Information System (INIS)

Denissenkov, Pavel A.

2010-01-01

The model of magnetic braking of solar rotation considered by Charbonneau and MacGregor has been modified so that it is able to reproduce for the first time the rotational evolution of both the fastest and slowest rotators among solar-type stars in open clusters of different ages, without coming into conflict with other observational constraints, such as the time evolution of the atmospheric Li abundance in solar twins and the thinness of the solar tachocline. This new model assumes that rotation-driven turbulent diffusion, which is thought to amplify the viscosity and magnetic diffusivity in stellar radiative zones, is strongly anisotropic with the horizontal components of the transport coefficients strongly dominating over those in the vertical direction. Also taken into account is the poloidal field decay that helps to confine the width of the tachocline at the solar age. The model's properties are investigated by numerically solving the azimuthal components of the coupled momentum and magnetic induction equations in two dimensions using a finite element method.

Mental rotation of faces in healthy aging and Alzheimer's disease.

Directory of Open Access Journals (Sweden)

Cassandra A Adduri

Full Text Available BACKGROUND: Previous research has shown that individuals with Alzheimer's disease (AD develop visuospatial difficulties that affect their ability to mentally rotate objects. Surprisingly, the existing literature has generally ignored the impact of this mental rotation deficit on the ability of AD patients to recognize faces from different angles. Instead, the devastating loss of the ability to recognize friends and family members in AD has primarily been attributed to memory loss and agnosia in later stages of the disorder. The impact of AD on areas of the brain important for mental rotation should not be overlooked by face processing investigations -- even in early stages of the disorder. METHODOLOGY/PRINCIPAL FINDINGS: This study investigated the sensitivity of face processing in AD, young controls and older non-neurological controls to two changes of the stimuli -- a rotation in depth and an inversion. The control groups showed a systematic effect of depth rotation, with errors increasing with the angle of rotation, and with inversion. The majority of the AD group was not impaired when faces were presented upright and no transformation in depth was required, and were most accurate when all faces were presented in frontal views, but accuracy was severely impaired with any rotation or inversion. CONCLUSIONS/SIGNIFICANCE: These results suggest that with the onset of AD, mental rotation difficulties arise that affect the ability to recognize faces presented at different angles. The finding that a frontal view is "preferred" by these patients provides a valuable communication strategy for health care workers.

Electronic structure and time-dependent description of rotational predissociation of LiH

DEFF Research Database (Denmark)

Jasik, P.; Sienkiewicz, J. E.; Domsta, J.

2017-01-01

parameters and the experimental ones. The dynamics of the rotational predissociation process of the 11Π state were studied by solving the time-dependent Schrödinger equation. The classical experiment of Velasco [Can. J. Phys., 1957, 35, 1204] on dissociation in the 11Π state is explained for the first time...

A possible interrelation between Earth rotation and climatic variability at decadal time-scale

Directory of Open Access Journals (Sweden)

Leonid Zotov

2016-05-01

Full Text Available Using multichannel singular spectrum analysis (MSSA we decomposed climatic time series into principal components, and compared them with Earth rotation parameters. The global warming trends were initially subtracted. Similar quasi 60 and 20 year periodic oscillations have been found in the global mean Earth temperature anomaly (HadCRUT4 and global mean sea level (GMSL. Similar cycles were also found in Earth rotation variation. Over the last 160 years multi-decadal change of Earth's rotation velocity is correlated with the 60-year temperature anomaly, and Chandler wobble envelope reproduces the form of the 60-year oscillation noticed in GMSL. The quasi 20-year oscillation observed in GMSL is correlated with the Chandler wobble excitation. So, we assume that Earth's rotation and climate indexes are connected. Despite of all the clues hinting this connection, no sound conclusion can be done as far as ocean circulation modelling is not able to correctly catch angular momentum of the oscillatory modes.

Characteristic time for halo current growth and rotation

Energy Technology Data Exchange (ETDEWEB)

Boozer, Allen H., E-mail: ahb17@columbia.edu [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

2015-10-15

A halo current flows for part of its path through the plasma edge and for part through the chamber walls and during tokamak disruptions can be as large as tenths of the plasma current. The primary interest in halo currents is the large force that they can exert on machine components particularly if the toriodal rotation of the halo current resonates with a natural oscillation frequency of the tokamak device. Halo currents arise when required to slow down the growth of a kink that is too unstable to be stabilized by the chamber walls. The width of the current channel in the halo plasma is comparable to the amplitude of the kink, and the halo current grows linearly, not exponentially, in time. The current density in the halo is comparable to that of the main plasma body. The rocket force due to plasma flowing out of the halo and recombining on the chamber walls can cause the non-axisymmetric magnetic structure produced by the kink to rotate toroidally at a speed comparable to the halo speed of sound. Gerhardt's observations of the halo current in NSTX shot 141 687 [Nucl. Fusion 53, 023005 (2013)] illustrate many features of the theory of halo currents and are discussed as a summary of the theory.

Time-of-flight mass spectrometer using an imaging detector and a rotating electric field

International Nuclear Information System (INIS)

Katayama, Atsushi; Kameo, Yutaka; Nakashima, Mikio

2008-01-01

A new technique for minor isotope analysis that uses a rotating electric field and an imaging detector is described. The rotating electric field is generated by six cylindrically arranged plane electrodes with multi-phase sinusoidal wave voltage. When ion packets that are discriminated by time-of-flight enter the rotating electric field, they are circularly deflected, rendering a spiral image on the fluorescent screen of the detector. This spiral image represents m/z values of ions as the position and abundance of ions as brightness. For minor isotopes analyses, the micro channel plate detector under gate control operation is used to eliminate the influence of high intensity of major isotopes. (author)

Implementation of a two-qubit controlled-rotation gate based on unconventional geometric phase with a constant gating time

International Nuclear Information System (INIS)

Yabu-uti, B.F.C.; Roversi, J.A.

2011-01-01

We propose an alternative scheme to implement a two-qubit controlled-R (rotation) gate in the hybrid atom-CCA (coupled cavities array) system. Our scheme results in a constant gating time and, with an adjustable qubit-bus coupling (atom-resonator), one can specify a particular rotation R on the target qubit. We believe that this proposal may open promising perspectives for networking quantum information processors and implementing distributed and scalable quantum computation. -- Highlights: → We propose an alternative two-qubit controlled-rotation gate implementation. → Our gate is realized in a constant gating time for any rotation. → A particular rotation on the target qubit can be specified by an adjustable qubit-bus coupling. → Our proposal may open promising perspectives for implementing distributed and scalable quantum computation.

Humeral head cysts and rotator cuff tears: an MR arthrographic study

Energy Technology Data Exchange (ETDEWEB)

Williams, Martin [Southmead Hospital, Department of Radiology, Westbury-on-Trym, Bristol (United Kingdom); Lambert, Robert G.W.; Jhangri, Gian S.; Grace, Michael; Zelaso, Jay; Wong, Ben; Dhillon, Sukhvinder S. [University of Alberta Hospital, Department of Radiology and Diagnostic Imaging, Edmonton (Canada)

2006-12-15

Humeral tuberosity cysts are a common finding, with previous reports suggesting they are related to rotator cuff tear or aging. The aim of this study was to investigate the characteristics of cysts in the tuberosities of the humeral head and their relationship with rotator cuff tear and age. Shoulder MR arthrograms were reviewed in 120 consecutive patients - 83 males (mean age 38.0, range 19-59 years) and 37 females (mean age 41.2, range 15-59 years). Patients were referred for investigation of a variety of conditions, and instability was suspected in only a minority of cases. MR was performed before and after direct arthrography with 0.01% solution of gadolinium. Cysts were defined as well-demarcated circular/ovoid foci in two planes that demonstrated high signal on pre-arthrographic T2W sequences. Location, size and numbers of cysts and post-arthrographic enhancement were documented, along with the location of rotator cuff tears, if present. Cysts in the tuberosities of the humerus were identified in 84 patients (70%), and were seen seven times more frequently in the posterior aspect of the greater tuberosity than anteriorly. Most cysts (94%) demonstrated communication with the joint post-arthrogram. Rotator cuff tears were present in 36 patients, and 79% of all tears occurred in supraspinatus tendon. There was no significant difference in the occurrence of cysts between patients older or younger than age 40 or between genders, but rotator cuff tears were seen significantly more often in the older age group (p<0.01). Tuberosity cysts and rotator cuff tears did not appear to be related (p=0.55). However, whilst this lack of association was quite obvious posteriorly (p=0.84), the trend in the anterior aspect of the greater tuberosity is not as clear (p=0.14). Humeral cysts are most often located in the posterior aspect of the greater tuberosity, communicate with the joint space and, in this location, are not related to aging or rotator cuff tear. (orig.)

Humeral head cysts and rotator cuff tears: an MR arthrographic study

International Nuclear Information System (INIS)

Williams, Martin; Lambert, Robert G.W.; Jhangri, Gian S.; Grace, Michael; Zelaso, Jay; Wong, Ben; Dhillon, Sukhvinder S.

2006-01-01

Humeral tuberosity cysts are a common finding, with previous reports suggesting they are related to rotator cuff tear or aging. The aim of this study was to investigate the characteristics of cysts in the tuberosities of the humeral head and their relationship with rotator cuff tear and age. Shoulder MR arthrograms were reviewed in 120 consecutive patients - 83 males (mean age 38.0, range 19-59 years) and 37 females (mean age 41.2, range 15-59 years). Patients were referred for investigation of a variety of conditions, and instability was suspected in only a minority of cases. MR was performed before and after direct arthrography with 0.01% solution of gadolinium. Cysts were defined as well-demarcated circular/ovoid foci in two planes that demonstrated high signal on pre-arthrographic T2W sequences. Location, size and numbers of cysts and post-arthrographic enhancement were documented, along with the location of rotator cuff tears, if present. Cysts in the tuberosities of the humerus were identified in 84 patients (70%), and were seen seven times more frequently in the posterior aspect of the greater tuberosity than anteriorly. Most cysts (94%) demonstrated communication with the joint post-arthrogram. Rotator cuff tears were present in 36 patients, and 79% of all tears occurred in supraspinatus tendon. There was no significant difference in the occurrence of cysts between patients older or younger than age 40 or between genders, but rotator cuff tears were seen significantly more often in the older age group (p<0.01). Tuberosity cysts and rotator cuff tears did not appear to be related (p=0.55). However, whilst this lack of association was quite obvious posteriorly (p=0.84), the trend in the anterior aspect of the greater tuberosity is not as clear (p=0.14). Humeral cysts are most often located in the posterior aspect of the greater tuberosity, communicate with the joint space and, in this location, are not related to aging or rotator cuff tear. (orig.)

Multi-relaxation-time Lattice Boltzman model for uniform-shear flow over a rotating circular cylinder

Directory of Open Access Journals (Sweden)

Nemati Hasan

2011-01-01

Full Text Available A numerical investigation of the two-dimensional laminar flow and heat transfer a rotating circular cylinder with uniform planar shear, where the free-stream velocity varies linearly across the cylinder using Multi-Relaxation-Time Lattice Boltzmann method is conducted. The effects of variation of Reynolds number, rotational speed ratio at shear rate 0.1, blockage ratio 0.1 and Prandtl number 0.71 are studied. The Reynolds number changing from 50 to 160 for three rotational speed ratios of 0, 0.5, 1 is investigated. Results show that flow and heat transfer depends significantly on the rotational speed ratio as well as the Reynolds number. The effect of Reynolds number on the vortex-shedding frequency and period-surface Nusselt numbers is overall very strong compared with rotational speed ratio. Flow and heat conditions characteristics such as lift and drag coefficients, Strouhal number and Nusselt numbers are studied.

Real-time estimation of prostate tumor rotation and translation with a kV imaging system based on an iterative closest point algorithm

International Nuclear Information System (INIS)

Tehrani, Joubin Nasehi; O’Brien, Ricky T; Keall, Paul; Poulsen, Per Rugaard

2013-01-01

Previous studies have shown that during cancer radiotherapy a small translation or rotation of the tumor can lead to errors in dose delivery. Current best practice in radiotherapy accounts for tumor translations, but is unable to address rotation due to a lack of a reliable real-time estimate. We have developed a method based on the iterative closest point (ICP) algorithm that can compute rotation from kilovoltage x-ray images acquired during radiation treatment delivery. A total of 11 748 kilovoltage (kV) images acquired from ten patients (one fraction for each patient) were used to evaluate our tumor rotation algorithm. For each kV image, the three dimensional coordinates of three fiducial markers inside the prostate were calculated. The three dimensional coordinates were used as input to the ICP algorithm to calculate the real-time tumor rotation and translation around three axes. The results show that the root mean square error was improved for real-time calculation of tumor displacement from a mean of 0.97 mm with the stand alone translation to a mean of 0.16 mm by adding real-time rotation and translation displacement with the ICP algorithm. The standard deviation (SD) of rotation for the ten patients was 2.3°, 0.89° and 0.72° for rotation around the right–left (RL), anterior–posterior (AP) and superior–inferior (SI) directions respectively. The correlation between all six degrees of freedom showed that the highest correlation belonged to the AP and SI translation with a correlation of 0.67. The second highest correlation in our study was between the rotation around RL and rotation around AP, with a correlation of −0.33. Our real-time algorithm for calculation of rotation also confirms previous studies that have shown the maximum SD belongs to AP translation and rotation around RL. ICP is a reliable and fast algorithm for estimating real-time tumor rotation which could create a pathway to investigational clinical treatment studies requiring

COMBINED EFFECTS OF BINARIES AND STELLAR ROTATION ON THE COLOR-MAGNITUDE DIAGRAMS OF INTERMEDIATE-AGE STAR CLUSTERS

International Nuclear Information System (INIS)

Li Zhongmu; Mao Caiyan; Chen Li; Zhang Qian

2012-01-01

About 70% of intermediate-age star clusters in the Large Magellanic Clouds have been confirmed to have broad main sequence, multiple or extended turnoffs, and dual red giant clumps. The observed result seems to be at odds with the classical idea that such clusters are simple stellar populations. Although many models have been used to explain the results via factors such as prolonged star formation history, metallicity spread, differential reddening, selection effect, observational uncertainty, stellar rotation, and binary interaction, the reason for the special color-magnitude diagrams is still uncertain. We revisit this question via the combination of stellar rotation and binary effects. As a result, it shows 'golf club' color-magnitude diagrams with broad or multiple turnoffs, dual red clumps, blue stragglers, red stragglers, and extended main sequences. Because both binaries and massive rotators are common, our result suggests that most color-magnitude diagrams, including extended turnoff or multiple turnoffs, can be explained using simple stellar populations including both binary and stellar rotation effects, or composite populations with two components.

Self-rotations in simulated microgravity: performance effects of strategy training.

Science.gov (United States)

Stirling, Leia; Newman, Dava; Willcox, Karen

2009-01-01

This research studies reorientation methodologies in a simulated microgravity environment using an experimental framework to reduce astronaut adaptation time and provide for a safety countermeasure during extravehicular activity. There were 20 subjects (10 men, 10 women, mean age of 23.6 +/- 3.5) who were divided into 2 groups, fully trained and minimally trained, which determined the amount of motion strategy training received. Subjects performed a total of 48 rotations about their pitch, roll, and yaw axes in a suspension system that simulated microgravity. In each trial subjects either rotated 90 degrees in pitch, 90 degrees in roll, or 180 degrees in yaw. Experimental measures include subject coordination, performance time, cognitive workload assessments, and qualitative motion control strategies. Subjects in the fully trained group had better initial performance with respect to performance time and workload scores for the pitch and yaw rotations. Further, trained subjects reached a steady-state performance time in fewer trials than those with minimal training. The subjects with minimal training tended to use motions that were common in an Earth environment since no technique was provided. For roll rotations they developed motions that would have led to significant off-axis (pitch and yaw) rotations in a true microgravity environment. We have shown that certain body axes are easier to rotate about than others and that fully trained subjects had an easier time performing the body rotations than the minimally trained subjects. This study has provided the groundwork for the development of an astronaut motion-control training program.

Time-dependent dynamical behavior of surface tension on rotating fluids under microgravity environment

Science.gov (United States)

Hung, R. J.; Tsao, Y. D.; Hong, B. B.; Leslie, F. W.

1988-01-01

Time dependent evolutions of the profile of free surface (bubble shapes) for a cylindrical container partially filled with a Newtonian fluid of constant density, rotating about its axis of symmetry, have been studied. Numerical computations of the dynamics of bubble shapes have been carried out with the following situations: (1) linear functions of spin-up and spin-down in low and microgravity environments, (2) step functions of spin-up and spin-down in a low gravity environment, and (3) sinusoidal function oscillation of gravity environment in high and low rotating cylinder speeds.

Global rotation

International Nuclear Information System (INIS)

Rosquist, K.

1980-01-01

Global rotation in cosmological models is defined on an observational basis. A theorem is proved saying that, for rigid motion, the global rotation is equal to the ordinary local vorticity. The global rotation is calculated in the space-time homogeneous class III models, with Godel's model as a special case. It is shown that, with the exception of Godel's model, the rotation in these models becomes infinite for finite affine parameter values. In some directions the rotation changes sign and becomes infinite in a direction opposite to the local vorticity. The points of infinite rotation are identified as conjugate points along the null geodesics. The physical interpretation of the infinite rotation is discussed, and a comparison with the behaviour of the area distance at conjugate points is given. (author)

Magnetostrictive patch sensor system for battery-less real-time measurement of torsional vibrations of rotating shafts

Science.gov (United States)

Lee, Jun Kyu; Seung, Hong Min; Park, Chung Il; Lee, Joo Kyung; Lim, Do Hyeong; Kim, Yoon Young

2018-02-01

Real-time uninterrupted measurement for torsional vibrations of rotating shafts is crucial for permanent health monitoring. So far, strain gauge systems with telemetry units have been used for real-time monitoring. However, they have a critical disadvantage in that shaft operations must be stopped intermittently to replace telemetry unit batteries. To find an alternative method to carry out battery-less real-time measurement for torsional vibrations of rotating shafts, a magnetostrictive patch sensor system was proposed in the present study. Since the proposed sensor does not use any powered telemetry system, no battery is needed and thus there is no need to stop rotating shafts for battery replacement. The proposed sensor consists of magnetostrictive patches and small magnets tightly bonded onto a shaft. A solenoid coil is placed around the shaft to convert magnetostrictive patch deformation by shaft torsional vibration into electric voltage output. For sensor design and characterization, investigations were performed in a laboratory on relatively small-sized stationary solid shaft. A magnetostrictive patch sensor system was then designed and installed on a large rotating propulsion shaft of an LPG carrier ship in operation. Vibration signals were measured using the proposed sensor system and compared to those measured with a telemetry unit-equipped strain gauge system.

Gender differences in rotation of the shank during single-legged drop landing and its relation to rotational muscle strength of the knee.

Science.gov (United States)

Kiriyama, Shinya; Sato, Haruhiko; Takahira, Naonobu

2009-01-01

Increased shank rotation during landing has been considered to be one of the factors for noncontact anterior cruciate ligament injuries in female athletes. There have been no known gender differences in rotational knee muscle strength, which is expected to inhibit exaggerated shank rotation. Women have less knee external rotator strength than do men. Lower external rotator strength is associated with increased internal shank rotation at the time of landing. Controlled laboratory study. One hundred sixty-nine healthy young subjects (81 female and 88 male; age, 17.0 +/- 1.0 years) volunteered to participate in this study. The subjects performed single-legged drop landings from a 20-cm height. Femoral and shank kinematics were measured using a 3D optoelectronic tracking system during the drop landings, and then the joint angles around the knee (flexion/extension, valgus/varus, and internal/external rotation) were calculated. The maximal isometric rotational muscle strength of the knee was measured at 30 degrees of knee flexion in a supine position using a dynamometer. The female subjects had significantly less external shank rotation strength than did the male subjects (P external rotation strength and the peak shank internal rotation angle during landing (r = -0.322, P external rotator strength. This may lead to large shank internal rotation movement during the single-legged drop landing. Improving strength training of the external rotator muscle may help decrease the rates of anterior cruciate ligament injury in female athletes.

Timing Solution and Single-pulse Properties for Eight Rotating Radio Transients

Energy Technology Data Exchange (ETDEWEB)

Cui, B.-Y.; McLaughlin, M. A. [Department of Physics and Astronomy West Virginia University Morgantown, WV 26506 (United States); Boyles, J. [Department of Physics and Astronomy West Kentucky University Bowling Green, KY 42101 (United States); Palliyaguru, N. [Physics and Astronomy Department Texas Tech University Lubbock, TX 79409-1051 (United States)

2017-05-01

Rotating radio transients (RRATs), loosely defined as objects that are discovered through only their single pulses, are sporadic pulsars that have a wide range of emission properties. For many of them, we must measure their periods and determine timing solutions relying on the timing of their individual pulses, while some of the less sporadic RRATs can be timed by using folding techniques as we do for other pulsars. Here, based on Parkes and Green Bank Telescope (GBT) observations, we introduce our results on eight RRATs including their timing-derived rotation parameters, positions, and dispersion measures (DMs), along with a comparison of the spin-down properties of RRATs and normal pulsars. Using data for 24 RRATs, we find that their period derivatives are generally larger than those of normal pulsars, independent of any intrinsic correlation with period, indicating that RRATs’ highly sporadic emission may be associated with intrinsically larger magnetic fields. We carry out Lomb–Scargle tests to search for periodicities in RRATs’ pulse detection times with long timescales. Periodicities are detected for all targets, with significant candidates of roughly 3.4 hr for PSR J1623−0841 and 0.7 hr for PSR J1839−0141. We also analyze their single-pulse amplitude distributions, finding that log-normal distributions provide the best fits, as is the case for most pulsars. However, several RRATs exhibit power-law tails, as seen for pulsars emitting giant pulses. This, along with consideration of the selection effects against the detection of weak pulses, imply that RRAT pulses generally represent the tail of a normal intensity distribution.

Timing Solution and Single-pulse Properties for Eight Rotating Radio Transients

Science.gov (United States)

Cui, B.-Y.; Boyles, J.; McLaughlin, M. A.; Palliyaguru, N.

2017-05-01

Rotating radio transients (RRATs), loosely defined as objects that are discovered through only their single pulses, are sporadic pulsars that have a wide range of emission properties. For many of them, we must measure their periods and determine timing solutions relying on the timing of their individual pulses, while some of the less sporadic RRATs can be timed by using folding techniques as we do for other pulsars. Here, based on Parkes and Green Bank Telescope (GBT) observations, we introduce our results on eight RRATs including their timing-derived rotation parameters, positions, and dispersion measures (DMs), along with a comparison of the spin-down properties of RRATs and normal pulsars. Using data for 24 RRATs, we find that their period derivatives are generally larger than those of normal pulsars, independent of any intrinsic correlation with period, indicating that RRATs’ highly sporadic emission may be associated with intrinsically larger magnetic fields. We carry out Lomb-Scargle tests to search for periodicities in RRATs’ pulse detection times with long timescales. Periodicities are detected for all targets, with significant candidates of roughly 3.4 hr for PSR J1623-0841 and 0.7 hr for PSR J1839-0141. We also analyze their single-pulse amplitude distributions, finding that log-normal distributions provide the best fits, as is the case for most pulsars. However, several RRATs exhibit power-law tails, as seen for pulsars emitting giant pulses. This, along with consideration of the selection effects against the detection of weak pulses, imply that RRAT pulses generally represent the tail of a normal intensity distribution.

Rotational velocities of low-mass stars

International Nuclear Information System (INIS)

Stauffer, J.B.; Hartmann, L.W.; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA)

1986-01-01

The rotational velocities of stars provide important clues to how stars form and evolve. Yet until recently, studies of stellar rotation were limited to stars more massive than the sun. This is beginning to change, and an observational outline of the rotational velocity evolution of stars less massive than the sun can now be provided. Low-mass stars rotate slowly during the early stages of premain-sequence evolution, and spin up as they contract to the main sequence. This spin-up culminates in a brief period of very rapid rotation at an age of order 50 million years. Physical interpretation of this increase in rotation and the subsequent main-sequence spin-down are complicated by the possibility of differential internal rotation. The observed rapidity of spin-down among G dwarfs suggests that initially only the outer convective envelopes of these stars are slowed. The data suggest an intrinsic spread in angular momentum among young stars of the same mass and age, a spread which is apparently minimized by the angular-momentum loss mechanism in old low-mass stars. 83 references

Ten Year Follow-Up of Gap Balanced, Rotating Platform Total Knee Arthroplasty in Patients Under 60 Years of Age.

Science.gov (United States)

Lee, Jason H; Barnett, Steven L; Patel, Jay J; Nassif, Nader A; Cummings, Dennis J; Gorab, Robert S

2016-01-01

68 patients (91 primary total knee arthroplasties) were evaluated at a mean 10-year, minimum 5 year follow up in patients younger than sixty years of age utilizing the gap balanced, rotating platform design. Follow up assessment included implant survivorship, adverse events, x-rays, Knee Society rating system and clinical evaluation. Three revisions were performed with only one for aseptic loosening at 45 months. Two manipulations were performed in the early postoperative period. Survivorship of the rotating platform, gap balanced knee was 96.7% using surgical revision for any reason and 98.9% using aseptic loosening as endpoints. The rotating platform design using the gap balancing technique in young patients had excellent survivorship at 10-year mean follow up. Copyright © 2016 Elsevier Inc. All rights reserved.

Original article The effect of three-dimensional imaging of well-known objects on time and accuracy of mental rotation

Directory of Open Access Journals (Sweden)

Piotr Francuz

2014-07-01

Full Text Available Background The purpose of this study was to verify hypotheses concerning the effect of three-dimensional imaging and the canonicity of objects presented in the original position on the reaction time (RT and the accuracy (A of mental rotation task (MRT execution. The classical paradigm of MRT, developed by Shepard and Metzler (1971, was used in the experiment. Participants and procedure One hundred fifty-eight undergraduate students (88 female and 70 male, aged 18-30 years, participated in the experiment. All participants had normal vision or corrected vision, and reported no stereo blindness. The sequential version of the MRT was used in the experiment. Participants answered whether the object observed in the second position was only rotated or both rotated and mirror-reversed, in comparison to its original position. The answer (accuracy and its latency (RT were recorded. Results As predicted by the mental rotation model, both the “U”-shaped A-MRT distribution and the inverted “U”-shaped RT-MRT distribution were found, due to the angular disparity. For the RT-MRT, this effect was more pronounced when the objects were displayed stereoscopically than in a plane, and when the objects were presented in the original position from the canonical orientation rather than an unusual point of view. On the other hand, in the case of the A-MRT, an effect of the orientation of objects presented in the original position on strengthening the relationship between accuracy and angular disparity was found. Conclusions The results indicated that the interactions between the presentation of the objects in the mental rotation task (stereoscopically vs. in a plane and the orientation of the object in its original position (canonically vs. unusual are more complicated than would appear from predictions of classical theories of mental rotation. The results of this study are discussed in relation to the theories of recognition and categorization.

Optical rotation calculated with time-dependent density functional theory: the OR45 benchmark.

Science.gov (United States)

Srebro, Monika; Govind, Niranjan; de Jong, Wibe A; Autschbach, Jochen

2011-10-13

Time-dependent density functional theory (TDDFT) computations are performed for 42 organic molecules and three transition metal complexes, with experimental molar optical rotations ranging from 2 to 2 × 10(4) deg cm(2) dmol(-1). The performances of the global hybrid functionals B3LYP, PBE0, and BHLYP, and of the range-separated functionals CAM-B3LYP and LC-PBE0 (the latter being fully long-range corrected), are investigated. The performance of different basis sets is studied. When compared to liquid-phase experimental data, the range-separated functionals do, on average, not perform better than B3LYP and PBE0. Median relative deviations between calculations and experiment range from 25 to 29%. A basis set recently proposed for optical rotation calculations (LPol-ds) on average does not give improved results compared to aug-cc-pVDZ in TDDFT calculations with B3LYP. Individual cases are discussed in some detail, among them norbornenone for which the LC-PBE0 functional produced an optical rotation that is close to available data from coupled-cluster calculations, but significantly smaller in magnitude than the liquid-phase experimental value. Range-separated functionals and BHLYP perform well for helicenes and helicene derivatives. Metal complexes pose a challenge to first-principles calculations of optical rotation.

Exponential time-dependent perturbation theory in rotationally inelastic scattering

International Nuclear Information System (INIS)

Cross, R.J.

1983-01-01

An exponential form of time-dependent perturbation theory (the Magnus approximation) is developed for rotationally inelastic scattering. A phase-shift matrix is calculated as an integral in time over the anisotropic part of the potential. The trajectory used for this integral is specified by the diagonal part of the potential matrix and the arithmetic average of the initial and final velocities and the average orbital angular momentum. The exponential of the phase-shift matrix gives the scattering matrix and the various cross sections. A special representation is used where the orbital angular momentum is either treated classically or may be frozen out to yield the orbital sudden approximation. Calculations on Ar+N 2 and Ar+TIF show that the theory generally gives very good agreement with accurate calculations, even where the orbital sudden approximation (coupled-states) results are seriously in error

EARTH’S ROTATIONAL DECELERATION: DETERMINATION OF TIDAL FRICTION INDEPENDENT OF TIMESCALES

International Nuclear Information System (INIS)

Deines, Steven D.; Williams, Carol A.

2016-01-01

This paper determines Earth's rotational deceleration without relying on atomic or ephemeris timescales. Earth's rotation defines the civil time standard called Universal Time (UT). Our previous paper did not examine tidal friction in depth when analyzing the timescale divergence between UT and International Atomic Time (TAI). We examine all available paleontological fossils and deposits for the direct measurements of Earth's past rotation rates, because that record includes all contributing effects. We examine paleontological reports that date Earth's rotation rate using corals, bivalves, brachiopods, rhythmites, and stromatolites. Contributions that vary Earth's moment of inertia, such as continental plate drifts, coastline changes, ice age formations, and viscous glacial rebounds, are superimposed with the secular deceleration. The average deceleration of Earth's rotation rate from all available fossil data is found to be (5.969 ± 1.762) × 10 −7 rad yr −2 . Our value is 99.8% of the total rotational deceleration determined by Christodoulidis et al., who used artificial satellite data, and our value is 96.6% of the expected tidal friction value obtained by Stephenson and Morrison. Taking the derivative of conserved angular momentum, the predicted lunar orbital deceleration caused by the average rotational deceleration corresponds closely to lunar models. When evaluating the significant time gaps between UT and TAI, Earth's rotational deceleration is a minor contributing factor. Also, the secular deceleration rate is necessary to correctly date ancient astronomical events. We strongly encourage that more ocean paleontological evidence be found to supplement the record to separate the many periodic variations embedded in these data

EARTH’S ROTATIONAL DECELERATION: DETERMINATION OF TIDAL FRICTION INDEPENDENT OF TIMESCALES

Energy Technology Data Exchange (ETDEWEB)

Deines, Steven D. [Donatech Corporation, Fairfield, IA 52556 (United States); Williams, Carol A., E-mail: steven.deines@gmail.com, E-mail: cw@math.usf.edu [Department of Mathematics and Statistics (Prof. emeritus), University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620 (United States)

2016-04-15

This paper determines Earth's rotational deceleration without relying on atomic or ephemeris timescales. Earth's rotation defines the civil time standard called Universal Time (UT). Our previous paper did not examine tidal friction in depth when analyzing the timescale divergence between UT and International Atomic Time (TAI). We examine all available paleontological fossils and deposits for the direct measurements of Earth's past rotation rates, because that record includes all contributing effects. We examine paleontological reports that date Earth's rotation rate using corals, bivalves, brachiopods, rhythmites, and stromatolites. Contributions that vary Earth's moment of inertia, such as continental plate drifts, coastline changes, ice age formations, and viscous glacial rebounds, are superimposed with the secular deceleration. The average deceleration of Earth's rotation rate from all available fossil data is found to be (5.969 ± 1.762) × 10{sup −7} rad yr{sup −2}. Our value is 99.8% of the total rotational deceleration determined by Christodoulidis et al., who used artificial satellite data, and our value is 96.6% of the expected tidal friction value obtained by Stephenson and Morrison. Taking the derivative of conserved angular momentum, the predicted lunar orbital deceleration caused by the average rotational deceleration corresponds closely to lunar models. When evaluating the significant time gaps between UT and TAI, Earth's rotational deceleration is a minor contributing factor. Also, the secular deceleration rate is necessary to correctly date ancient astronomical events. We strongly encourage that more ocean paleontological evidence be found to supplement the record to separate the many periodic variations embedded in these data.

Motor Processes in Children's Mental Rotation

Science.gov (United States)

Frick, Andrea; Daum, Moritz M.; Walser, Simone; Mast, Fred W.

2009-01-01

Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a…

Epidemiology, natural history, and indications for treatment of rotator cuff tears.

Science.gov (United States)

Tashjian, Robert Z

2012-10-01

The etiology of rotator cuff disease is likely multifactorial, including age-related degeneration and microtrauma and macrotrauma. The incidence of rotator cuff tears increases with aging with more than half of individuals in their 80s having a rotator cuff tear. Smoking, hypercholesterolemia, and genetics have all been shown to influence the development of rotator cuff tearing. Substantial full-thickness rotator cuff tears, in general, progress and enlarge with time. Pain, or worsening pain, usually signals tear progression in both asymptomatic and symptomatic tears and should warrant further investigation if the tear is treated conservatively. Larger (>1-1.5 cm) symptomatic full-thickness cuff tears have a high rate of tear progression and, therefore, should be considered for earlier surgical repair in younger patients if the tear is reparable and there is limited muscle degeneration to avoid irreversible changes to the cuff, including tear enlargement and degenerative muscle changes. Smaller symptomatic full-thickness tears have been shown to have a slower rate of progression, similar to partial-thickness tears, and can be considered for initial nonoperative treatment due to the limited risk for rapid tear progression. In both small full-thickness tears and partial-thickness tears, increasing pain should alert physicians to obtain further imaging as it can signal tear progression. Natural history data, along with information on factors affecting healing after rotator cuff repair, can help guide surgeons in making appropriate decisions regarding the treatment of rotator cuff tears. The management of rotator cuff tears should be considered in the context of the risks and benefits of operative versus nonoperative treatment. Tear size and acuity, the presence of irreparable changes to the rotator cuff or glenohumeral joint, and patient age should all be considered in making this decision. Initial nonoperative care can be safely undertaken in older patients (>70

Forest value and optimal rotations in continuous cover forestry

DEFF Research Database (Denmark)

Jacobsen, Jette Bredahl; Jensen, Frank; Thorsen, Bo Jellesmark

2018-01-01

The Faustmann forest rotation model is a celebrated contribution in economics. The model provides a forest value expression and allows a solution to the optimal rotation problem valid for perpetual rotations of even-aged forest stands. However, continuous forest cover forest management systems......, but rigorous mathematical model of the continuous cover forest, which strictly focuses on the area use dynamics that such an uneven-aged forest must have in equilibrium. This implies explicitly accounting for area reallocation and for weighting the productivity of each age class by the area occupied. We...... present results for unrestricted as well as area-restricted versions of the models. We find that land values are unambiguously higher in the continuous cover forest models compared with the even-aged models. Under area restrictions, the optimal rotation age in a continuous cover forest model...

Ultrafast time-resolved faraday rotation in EuO thin films.

Science.gov (United States)

Liu, F; Makino, T; Yamasaki, T; Ueno, K; Tsukazaki, A; Fukumura, T; Kong, Y; Kawasaki, M

2012-06-22

We have investigated the ultrafast spin dynamics in EuO thin films by time-resolved Faraday rotation spectroscopy. The photoinduced magnetization is found to be increased in a transient manner, accompanied with subsequent demagnetization. The dynamical magnetization enhancement showed a maximum slightly below the Curie temperature with prolonged tails toward both lower and higher temperatures and dominates the demagnetization counterpart at 55 K. The magnetization enhancement component decays in ~1 ns. The realization of the transient collective ordering is attributable to the enhancement of the f-d exchange interaction.

Vibration analysis for trending ageing in rotating machinery

International Nuclear Information System (INIS)

Sinha, S.K.; Rama Rao, A.

2006-01-01

The need for condition monitoring system for important equipment and machinery is a growing requirement in every industry and more so in the nuclear power plants because of stringent safety requirements. This is largely because of the inherent benefit of being able to promote predictive maintenance practice rather than uneconomical preventive maintenance practice in the plant. Forerunner among the condition monitoring parameter is vibration signatures measured on a rotating machine. It is known that every moving element in a rotating machine generates vibration signal that is uniquely its own. Detection of such signals and monitoring the changing conditions in a machine through vibration analysis is a technique involving the knowledge of engineering art and the mathematical theory. This blend of sound engineering judgement and vibration data interpretation skill is in fact the basis of vibration diagnostic techniques. (author)

Time-varying Entry Heating Profile Replication with a Rotating Arc Jet Test Article

Science.gov (United States)

Grinstead, Jay Henderson; Venkatapathy, Ethiraj; Noyes, Eric A.; Mach, Jeffrey J.; Empey, Daniel M.; White, Todd R.

2014-01-01

A new approach for arc jet testing of thermal protection materials at conditions approximating the time-varying conditions of atmospheric entry was developed and demonstrated. The approach relies upon the spatial variation of heat flux and pressure over a cylindrical test model. By slowly rotating a cylindrical arc jet test model during exposure to an arc jet stream, each point on the test model will experience constantly changing applied heat flux. The predicted temporal profile of heat flux at a point on a vehicle can be replicated by rotating the cylinder at a prescribed speed and direction. An electromechanical test model mechanism was designed, built, and operated during an arc jet test to demonstrate the technique.

Time Perspective and Age: A Review of Age Associated Differences.

Science.gov (United States)

Laureiro-Martinez, Daniella; Trujillo, Carlos A; Unda, Juliana

2017-01-01

We investigate the relationship between age and the five dimensions of time perspective measured by the Zimbardo Time Perspective Inventory (ZTPI) (past negative, past positive, present hedonistic, present fatalistic, and future). Time perspective is related to well-being, decision-making, level of development, and many other psychological issues. Hence, the existence of a systematic relationship between time perspective and age should be considered in all studies for which time is a relevant variable. However, no specific research about this has been conducted. We collected 407 papers that referenced the ZTPI between 2001 and 2015. From those, 72 studies met our inclusion criteria. They included 29,815 participants from 19 countries whose age spans most phases of adulthood (from 13.5 to 75.5 years, mean 28.7). We analyzed these studies adapting meta-analytical techniques. We found that present hedonistic and past negative dimensions are negatively related to aging with partial eta squared effect sizes of roughly 0.15. Our results have implications for the design of studies related to time as our findings highlight the importance of taking into account the differences associated with age.

Rotational and translational diffusions of fluorescent probes during gelation process

Science.gov (United States)

Hattori, Yusuke; Panizza, Pascal; Letamendia, Louis; Ushiki, Hideharu

2006-04-01

Gelation process has been investigated by using light scattering techniques in recent years. We measured both of rotational and translational motions of fluorescent probes during gelation process. The measurements were performed after the temperature quenched at 30 °C. As the results, rotational diffusion coefficient of fluorescein was decreased after 6.0 × 10 4 s and energy transfer rate was reduced after 2.0 × 10 4 s. We sorted the gelation process into the following three parts, (I) pre-gelation, (II) reduction of translational diffusion (aging), and (III) reduction of rotational diffusion with saturating translational diffusion (post-gelation). The time scale of the process was completely different from the results of other methods.

Intra- and interrater reliability of the 'lumbar-locked thoracic rotation test' in competitive swimmers ages 10 through 18 years.

Science.gov (United States)

Feijen, Stef; Kuppens, Kevin; Tate, Angela; Baert, Isabel; Struyf, Thomas; Struyf, Filip

2018-04-17

Measuring thoracic spine mobility can be of interest to competitive swimmers as it has been associated with shoulder girdle function and scapular position in subjects with and without shoulder pain. At present, no reliability data of thoracic spine mobility measurements are available in the swimming population. This study aims to evaluate the within-session intra- and interrater reliability of the "lumbar-locked rotation test" for thoracic spine rotation in competitive swimmers aged 10 to 18 years. This reliability study is part of a larger prospective cohort study investigating potential risk factors for the development of shoulder pain in competitive swimmers. Within-session, intra- and inter-rater reliability. Competitive swimming clubs in Belgium. 21 competitive swimmers. Intra- and inter-rater reliability of the lumbar-locked thoracic rotation test. Intraclass correlation coefficients (ICCs) ranged from 0.91 (95% CI 0.78 to 0.96) to 0.96 (0.89-0.98) for intra-rater reliability. Results for inter-rater reliability ranged from 0.89 (0.72-0.95) to 0.86 (0.65-0.94) respectively for right and left thoracic rotation. Results suggest good to excellent reliability of the lumbar-locked thoracic rotation test, indicating this test can be used reliably in clinical practice. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rotated sigmoid structures in managed uneven-aged northern hardwood stands: a look at the Burr Type III distribution

Science.gov (United States)

Jeffrey H. Gove; Mark J. Ducey; William B. Leak; Lianjun Zhang

2008-01-01

Stand structures from a combined density manipulation and even- to uneven-aged conversion experiment on the Bartlett Experimental Forest (New Hampshire, USA) were examined 25 years after initial treatment for rotated sigmoidal diameter distributions. A comparison was made on these stands between two probability density functions for fitting these residual structures:...

Laterality-Specific Training Improves Mental Rotation Performance in Young Soccer Players.

Science.gov (United States)

Pietsch, Stefanie; Jansen, Petra

2018-01-01

This study investigates the influence of specific soccer training with the non-dominant leg on mental rotation performance of 20 adolescent soccer players between 10 and 11 years of age. While the experimental group performed soccer specific tasks only with the non-dominant foot once a week for 10 weeks, the control group absolved the same exercises with the dominant foot for the same period of time. Both groups performed a mental rotation task and shot, dribbling and ball control tests before and after the 10 week intervention. The most relevant result was that the experimental group showed a significantly larger increase in mental rotation ability than the control group.

Arthroscopic undersurface rotator cuff repair versus conventional arthroscopic double-row rotator cuff repair - Comparable results at 2-year follow-up.

Science.gov (United States)

Ang, Benjamin Fu Hong; Chen, Jerry Yongqiang; Yeo, William; Lie, Denny Tijauw Tjoen; Chang, Paul Chee Cheng

2018-01-01

The aim of our study is to compare the improvement in clinical outcomes after conventional arthroscopic double-row rotator cuff repair and arthroscopic undersurface rotator cuff repair. A consecutive series of 120 patients who underwent arthroscopic rotator cuff repair was analysed. Sixty-one patients underwent conventional double-row rotator cuff repair and 59 patients underwent undersurface rotator cuff repair. Several clinical outcomes, including numerical pain rating scale (NPRS), constant shoulder score (CSS), Oxford shoulder score (OSS) and University of California Los Angeles shoulder score (UCLASS), were prospectively recorded by a trained healthcare professional preoperatively and at 3, 6, 12 and 24 months after surgery. Comparing both groups, there were no differences in age, gender and preoperative NPRS, CSS, OSS and UCLASS. However, the tear size was 0.7 ± 0.2 (95% confidence interval (CI) 0.3-1.1) cm larger in the conventional group ( p = 0.002). There was no difference in the improvement of NPRS, CSS, OSS and UCLASS at all time points of follow-up, that is, at 3, 6, 12 and 24 months after surgery. The duration of operation was shorter by 35 ± 3 (95% CI 28-42) min in the undersurface group ( p rotator cuff repair and conventional arthroscopic double-row rotator cuff repair showed marked improvements in clinical scores when compared preoperatively, and there was no difference in improvements between both groups. Arthroscopic undersurface rotator cuff repair is a faster technique compared to the conventional arthroscopic double-row rotator cuff repair.

Variations in VLT/UVES-based OH rotational temperatures for time scales from hours to 15 years

Science.gov (United States)

Noll, Stefan; Kimeswenger, Stefan; Proxauf, Bastian; Kausch, Wolfgang; Unterguggenberger, Stefanie; Jones, Amy M.

2017-04-01

Hydroxyl (OH) emission is an important tracer of the climate, chemistry, and dynamics of the Earth's mesopause region. However, the relation of intensity variations in different OH lines is not well understood yet. This is critical for the most popular use of OH lines: the estimate of ambient temperatures based on transitions at low rotational levels of the same band. It is possible that the measured variability of the derived rotational temperature does not coincide with changes in the ambient temperature. Such differences can be caused by varying deviations from the local thermodynamic equilibrium (LTE) for the population distribution over the considered rotational levels. The non-LTE effects depend on the ratio of the thermalising collisions (mostly related to molecular oxygen) and competing radiative transitions or collisions without thermalisation of the rotational level distribution. Therefore, significant changes in the vertical structure of excited OH and its main quenchers can affect the temperature measurements. We have investigated the variability of OH rotational temperatures and the corresponding contributions of non-LTE effects for different OH bands and time scales up to 15 years based on data of the high-resolution echelle spectrograph UVES at the Very Large Telescope at Cerro Paranal in Chile. In order to link the measured rotational temperatures with the structure of the OH emission layer, we have also studied OH emission and kinetic temperature profiles from the multi-channel radiometer SABER on the TIMED satellite taken between 2002 and 2015. The results show that non-LTE contributions can significantly affect the OH rotational temperatures. Their variations can be especially strong during the night and for high upper vibrational levels of the transitions, where amplitudes of several Kelvins can be measured. They appear to be weak if long-term variations such as those caused by the solar cycle are investigated. These differences in the response

Evaluation of the Risk Factors for a Rotator Cuff Retear After Repair Surgery.

Science.gov (United States)

Lee, Yeong Seok; Jeong, Jeung Yeol; Park, Chan-Deok; Kang, Seung Gyoon; Yoo, Jae Chul

2017-07-01

A retear is a significant clinical problem after rotator cuff repair. However, no study has evaluated the retear rate with regard to the extent of footprint coverage. To evaluate the preoperative and intraoperative factors for a retear after rotator cuff repair, and to confirm the relationship with the extent of footprint coverage. Cohort study; Level of evidence, 3. Data were retrospectively collected from 693 patients who underwent arthroscopic rotator cuff repair between January 2006 and December 2014. All repairs were classified into 4 types of completeness of repair according to the amount of footprint coverage at the end of surgery. All patients underwent magnetic resonance imaging (MRI) after a mean postoperative duration of 5.4 months. Preoperative demographic data, functional scores, range of motion, and global fatty degeneration on preoperative MRI and intraoperative variables including the tear size, completeness of rotator cuff repair, concomitant subscapularis repair, number of suture anchors used, repair technique (single-row or transosseous-equivalent double-row repair), and surgical duration were evaluated. Furthermore, the factors associated with failure using the single-row technique and transosseous-equivalent double-row technique were analyzed separately. The retear rate was 7.22%. Univariate analysis revealed that rotator cuff retears were affected by age; the presence of inflammatory arthritis; the completeness of rotator cuff repair; the initial tear size; the number of suture anchors; mean operative time; functional visual analog scale scores; Simple Shoulder Test findings; American Shoulder and Elbow Surgeons scores; and fatty degeneration of the supraspinatus, infraspinatus, and subscapularis. Multivariate logistic regression analysis revealed patient age, initial tear size, and fatty degeneration of the supraspinatus as independent risk factors for a rotator cuff retear. Multivariate logistic regression analysis of the single-row group

Factors impacting arthroscopic rotator cuff repair operational throughput time at an ambulatory care center

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Emily J. Curry

2018-03-01

Full Text Available Identifying patient factors influencing operational throughput time is becoming more imperative due to an increasing focus on value and cost savings in healthcare. The primary objective of this study was to determine patient factors influencing throughput time for primary rotator cuff repairs. Demographic information, medical history and operative reports of 318 patients from one ambulatory care center were retrospectively reviewed. Operating room set up, incision to closure and recovery room time were collected from anesthesia records. Univariate analysis was performed for both continuous and categorical variables. A stepwise, multivariable regression analysis was performed to determine factors associated with operating room time (incision to closure and recovery room time. Of the 318 patients, the mean age was 54.4±10.0 and 197 (61% were male. Male patients had a significantly longer OR time than females (115.5 vs. 100.8 minutes; P<0.001. Furthermore, patients set up in the beach chair position had a significantly longer OR time than patients positioned lateral decubitus (115.8 vs. 89.6 mins, P<0.0001. Number of tendons involved, and inclusion of distal clavicle excision, biceps tenodesis and labral debridement also added significant OR time. Type and number of support staff present also significantly affected OR time. Recovery room time was significantly longer patients who had surgery in the beach chair position (+9.61 minutes and for those who had a cardiac-related medical comorbidity (+11.7 minutes. Our study found that patients positioned in a beach chair spent significantly more time in the operating and recovery rooms. While ease of set up has been a stated advantage ofbeach chair position, we found the perceived ease of set up does not result in more efficient OR throughput.

Comparison of self-report and interview administration methods based on the Brazilian versions of the Western Ontario Rotator Cuff Index and Disabilities of the Arm, Shoulder and Hand Questionnaire in patients with rotator cuff disorders

Directory of Open Access Journals (Sweden)

Andréa Diniz Lopes

2009-02-01

Full Text Available OBJECTIVE: The purpose of the present study was to compare self-report and interview administration methods using the Western Ontario Rotator Cuff Index (WORC and Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH in patients with rotator cuff disorders. METHODS: Thirty male and female patients over 18 years of age with rotator cuff disorders (tendinopathy or rotator cuff tear and Brazilian Portuguese as their primary language were recruited for assessment via administration of the Western Ontario Rotator Cuff Index and and Disabilities of the Arm, Shoulder and Hand Questionnaire. A randomization method was used to determine whether the questionnaires would be self-reported (n=15 or administered by an interviewer (n=15. Pearson correlation coefficients were used to evaluate the correlation between the Western Ontario Rotator Cuff Index and and Disabilities of the Arm, Shoulder and Hand Questionnaire in each group. The t-test was used to determine whether the difference in mean questionnaire scores and administration time was statistically significant. For statistical analysis, the level of significance was set at 5%. RESULTS: The mean subject age was 55.07 years, ranging from 27 to 74 years. Most patients had a diagnosis of tendinopathy (n=21. With regard to level of schooling, the majority (n=26 of subjects had completed a college degree or higher. The mean questionnaire scores and administration times did not significantly differ between the two groups (p>0.05. There were statistically significant correlations (p<0.05 between Western Ontario Rotator Cuff Index and and Disabilities of the Arm, Shoulder and Hand Questionnaire, and strong correlations were found between the questionnaires in both groups. CONCLUSION: There are no differences between the Western Ontario Rotator Cuff Index and Disabilities of the Arm, Shoulder and Hand Questionnaire administration methods with regard to administration time or correlations between the

Forest value and optimal rotations in continuous cover forestry

DEFF Research Database (Denmark)

Jacobsen, Jette Bredahl; Jensen, Frank; Thorsen, Bo Jellesmark

The Faustmann forest rotation model is a celebrated contribution in economics. The model provides a forest value expression and allows a solution to the optimal rotation problem valid for perpetual rotations of even-aged forest stands. However, continuous forest cover forest management systems......, but rigorous mathematical model of the continuous cover forest, which strictly focuses on the area use dynamics that such an uneven-aged forest must have in equilibrium. This implies explicitly accounting for area reallocation and for weighting the productivity of each age class by the area occupied. The model...... allows for a simple expression for forest value and the derivation of conditions for the optimal rotation age. The model also makes straightforward comparisons with the well-known Faustmann model possible. We present results for unrestricted as well as area-restricted versions of the models. We find...

SOLAR CYCLE VARIABILITY AND SURFACE DIFFERENTIAL ROTATION FROM Ca II K-LINE TIME SERIES DATA

Energy Technology Data Exchange (ETDEWEB)

Scargle, Jeffrey D.; Worden, Simon P. [NASA Ames Research Center, Moffett Field, CA, 94035 (United States); Keil, Stephen L. [National Solar Observatory, P.O. Box 57, Sunspot, NM 88349 (United States)

2013-07-01

Analysis of over 36 yr of time series data from the NSO/AFRL/Sac Peak K-line monitoring program elucidates 5 components of the variation of the 7 measured chromospheric parameters: (a) the solar cycle (period {approx} 11 yr), (b) quasi-periodic variations (periods {approx} 100 days), (c) a broadband stochastic process (wide range of periods), (d) rotational modulation, and (e) random observational errors, independent of (a)-(d). Correlation and power spectrum analyses elucidate periodic and aperiodic variation of these parameters. Time-frequency analysis illuminates periodic and quasi-periodic signals, details of frequency modulation due to differential rotation, and in particular elucidates the rather complex harmonic structure (a) and (b) at timescales in the range {approx}0.1-10 yr. These results using only full-disk data suggest that similar analyses will be useful for detecting and characterizing differential rotation in stars from stellar light curves such as those being produced by NASA's Kepler observatory. Component (c) consists of variations over a range of timescales, in the manner of a 1/f random process with a power-law slope index that varies in a systematic way. A time-dependent Wilson-Bappu effect appears to be present in the solar cycle variations (a), but not in the more rapid variations of the stochastic process (c). Component (d) characterizes differential rotation of the active regions. Component (e) is of course not characteristic of solar variability, but the fact that the observational errors are quite small greatly facilitates the analysis of the other components. The data analyzed in this paper can be found at the National Solar Observatory Web site http://nsosp.nso.edu/cak{sub m}on/, or by file transfer protocol at ftp://ftp.nso.edu/idl/cak.parameters.

Surgical Versus Nonsurgical Management of Rotator Cuff Tears: Predictors of Treatment Allocation.

Science.gov (United States)

Kweon, Christopher; Gagnier, Joel J; Robbins, Christopher B; Bedi, Asheesh; Carpenter, James E; Miller, Bruce S

2015-10-01

Rotator cuff tears are a common shoulder disorder resulting in significant disability to patients and financial burden on the health care system. While both surgical and nonsurgical management are accepted treatment options, there is a paucity of data to support a treatment algorithm for care providers. Defining variables to guide treatment allocation may be important for patient education and counseling, as well as to deliver the most efficient care plan at the time of presentation. To identify independent variables at the time of initial clinical presentation that are associated with preferred allocation to surgical versus nonsurgical management for patients with known full-thickness rotator cuff tears. Case control study; Level of evidence, 3. A total of 196 consecutive adult patients with known full-thickness rotator cuff tears were enrolled into a prospective cohort study. Robust data were collected for each subject at baseline, including age, sex, body mass index (BMI), shoulder activity score, smoking status, size of cuff tear, duration of symptoms, functional comorbidity index, the American Shoulder and Elbow Surgeons (ASES) score, the Western Ontario Rotator Cuff index (WORC), and the Veterans Rand 12-Item Health Survey (VR-12). Logistic regression was performed to identify variables associated with treatment allocation, and the corresponding odds ratios were calculated. Of the 196 patients enrolled, 112 underwent surgical intervention and 84 nonoperative management. With covariates controlled for, significant baseline patient characteristics predictive of eventual allocation to surgical treatment included younger age, lower BMI, and durations of symptoms less than 1 year. Increasing age, higher BMI, and duration of symptoms longer than 1 year were predictive of nonsurgical treatment. Factors that were not associated with treatment allocation included sex, tear size, functional comorbidity score, or any of the patient-derived outcome scores at presentation

SU-E-I-60: The Correct Selection of Pitch and Rotation Time for Optimal CT Scanning : The Big Misconception

International Nuclear Information System (INIS)

Ranallo, F; Szczykutowicz, T

2014-01-01

Purpose: To provide correct guidance in the proper selection of pitch and rotation time for optimal CT imaging with multi-slice scanners. Methods: There exists a widespread misconception concerning the role of pitch in patient dose with modern multi-slice scanners, particularly with the use of mA modulation techniques. We investigated the relationship of pitch and rotation time to image quality, dose, and scan duration, with CT scanners from different manufacturers in a way that clarifies this misconception. This source of this misconception may concern the role of pitch in single slice CT scanners. Results: We found that the image noise and dose are generally independent of the selected effective mAs (mA*time/ pitch) with manual mA technique settings and are generally independent of the selected pitch and /or rotation time with automatic mA modulation techniques. However we did find that on certain scanners the use of a pitch just above 0.5 provided images of equal image noise at a lower dose compared to the use of a pitch just below 1.0. Conclusion: The misconception that the use of a lower pitch over-irradiates patients by wasting dose is clearly false. The use of a lower pitch provides images of equal or better image quality at the same patient dose, whether using manual mA or automatic mA modulation techniques. By decreasing the pitch and the rotation times by equal amounts, both helical and patient motion artifacts can be reduced without affecting the exam time. The use of lower helical pitch also allows better scanning of larger patients by allowing a greater scan effective mAs, if the exam time can be extended. The one caution with the use of low pitch is not related to patient dose, but to the length of the scan time if the rotation time is not set short enough. Partial Research funding from GE HealthCare

Locally Rotationally Symmetric Bianchi Type-I Model with Time Varying Λ Term

International Nuclear Information System (INIS)

Tiwari, R. K.; Jha, Navin Kumar

2009-01-01

We investigate the locally rotationally symmetric (LRS) Bianchi type-I cosmological model for stiff matter and a vacuum solution with a cosmological term proportional to R −m (R is the scale factor and m is a positive constant). The cosmological term decreases with time. We obtain that for both the cases the present universe is accelerating with a large fraction of cosmological density in the form of a cosmological term

Laterality-Specific Training Improves Mental Rotation Performance in Young Soccer Players

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Stefanie Pietsch

2018-02-01

Full Text Available This study investigates the influence of specific soccer training with the non-dominant leg on mental rotation performance of 20 adolescent soccer players between 10 and 11 years of age. While the experimental group performed soccer specific tasks only with the non-dominant foot once a week for 10 weeks, the control group absolved the same exercises with the dominant foot for the same period of time. Both groups performed a mental rotation task and shot, dribbling and ball control tests before and after the 10 week intervention. The most relevant result was that the experimental group showed a significantly larger increase in mental rotation ability than the control group.

Analysis of failed rotator cuff repair – Retrospective survey of revisions after open rotator cuff repair

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Rupert Schupfner

2017-07-01

Full Text Available Background Rotator cuff defects are frequently occurring shoulder pathologies associated with pain and movement impairment. Aims The aim of the study was to analyse the pathologies that lead to operative revisions after primary open rotator cuff repair. Methods In 216 patients who underwent primary rotator cuff repair and later required operative revision between 1996 to 2005, pathologies found intraoperatively during the primary operation and during revision surgery were collected, analysed and compared. Results The average age at the time of revision surgery was 54.3 years. The right shoulder (61.6 per cent was more often affected than the left, males (63.4 per cent more often than females. At primary operation – apart from rotator cuff repair – there were the following surgical procedures performed: 190 acromioplasty, 86 Acromiclavicular joint resections, 68 tenodesis, 40 adhesiolysis and 1 tenotomy. If an ACJ-resection had been performed in the primary operation, ACJ-problems were rare in revision surgery (p<0.01. Primary gleno-humeral adhesions were associated with a significant rise in re-tearing rate (p=0.049. Primary absence of adhesions went along with a significant lower rate of adhesions found at revision (p=0.018. Primary performed acromioplasty had no influence on re-tearing rate (p=0.408 or on the rate of subacromial impingement at revision surgery (p=0.709. Conclusion To avoid operative revision after rotator cuff repair relevant copathologies of the shoulder have to be identified before or during operation and treated accordingly. Therefore, even during open rotator cuff repair, the surgeon should initially start with arthroscopy of the shoulder joint and subacromial space to recognise co-pathologies.

A conservative quaternion-based time integration algorithm for rigid body rotations with implicit constraints

DEFF Research Database (Denmark)

Nielsen, Martin Bjerre; Krenk, Steen

2012-01-01

A conservative time integration algorithm for rigid body rotations is presented in a purely algebraic form in terms of the four quaternions components and the four conjugate momentum variables via Hamilton’s equations. The introduction of an extended mass matrix leads to a symmetric set of eight...

Effect of time step size and turbulence model on the open water hydrodynamic performance prediction of contra-rotating propellers

Science.gov (United States)

Wang, Zhan-zhi; Xiong, Ying

2013-04-01

A growing interest has been devoted to the contra-rotating propellers (CRPs) due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibration. Compared with the single-screw system, it is more difficult for the open water performance prediction because forward and aft propellers interact with each other and generate a more complicated flow field around the CRPs system. The current work focuses on the open water performance prediction of contra-rotating propellers by RANS and sliding mesh method considering the effect of computational time step size and turbulence model. The validation study has been performed on two sets of contra-rotating propellers developed by David W Taylor Naval Ship R & D center. Compared with the experimental data, it shows that RANS with sliding mesh method and SST k-ω turbulence model has a good precision in the open water performance prediction of contra-rotating propellers, and small time step size can improve the level of accuracy for CRPs with the same blade number of forward and aft propellers, while a relatively large time step size is a better choice for CRPs with different blade numbers.

The rotating universe

International Nuclear Information System (INIS)

Ruben, G.; Treder, H.J.

1987-01-01

For a long time the question whether the universe rotates or not is discussed. Aspects of Huygens, Newton, Mach and other important historical scientists in this field are reported. The investigations of the mathematician Kurt Groedel in order to prove the rotation of the universe are illustrated. Kurt Groedel has shown that Einstein's gravitational equations of general relativity theory and the cosmological postulate of global homogeneity of cosmic matter (that is the Copernical principle) are not contradictionary to a rotating universe. Abberation measurements, position determination by means of radiointerferometry and methods for the determination of the rotation of the universe from the isotropy of the background radiation are presented. From these experiments it can be concluded that the universe seems not to rotate as already Einstein expected

Linking age, survival, and transit time distributions

Science.gov (United States)

Calabrese, Salvatore; Porporato, Amilcare

2015-10-01

Although the concepts of age, survival, and transit time have been widely used in many fields, including population dynamics, chemical engineering, and hydrology, a comprehensive mathematical framework is still missing. Here we discuss several relationships among these quantities by starting from the evolution equation for the joint distribution of age and survival, from which the equations for age and survival time readily follow. It also becomes apparent how the statistical dependence between age and survival is directly related to either the age dependence of the loss function or the survival-time dependence of the input function. The solution of the joint distribution equation also allows us to obtain the relationships between the age at exit (or death) and the survival time at input (or birth), as well as to stress the symmetries of the various distributions under time reversal. The transit time is then obtained as a sum of the age and survival time, and its properties are discussed along with the general relationships between their mean values. The special case of steady state case is analyzed in detail. Some examples, inspired by hydrologic applications, are presented to illustrate the theory with the specific results. This article was corrected on 11 Nov 2015. See the end of the full text for details.

Dynamic Time-Resolved Chirped-Pulse Rotational Spectroscopy of Vinyl Cyanide Photoproducts in a Room Temperature Flow Reactor

Science.gov (United States)

Zaleski, Daniel P.; Prozument, Kirill

2017-06-01

Chirped-pulsed (CP) Fourier transform rotational spectroscopy invented by Brooks Pate and coworkers a decade ago is an attractive tool for gas phase chemical dynamics and kinetics studies. A good reactor for such a purpose would have well-defined (and variable) temperature and pressure conditions to be amenable to accurate kinetic modeling. Furthermore, in low pressure samples with large enough number of molecular emitters, reaction dynamics can be observable directly, rather than mediated by supersonic expansion. In the present work, we are evaluating feasibility of in situ time-resolved CP spectroscopy in a room temperature flow tube reactor. Vinyl cyanide (CH_2CHCN), neat or mixed with inert gasses, flows through the reactor at pressures 1-50 μbar (0.76-38 mTorr) where it is photodissociated by a 193 nm laser. Millimeter-wave beam of the CP spectrometer co-propagates with the laser beam along the reactor tube and interacts with nascent photoproducts. Rotational transitions of HCN, HNC, and HCCCN are detected, with ≥10 μs time-steps for 500 ms following photolysis of CH_2CHCN. The post-photolysis evolution of the photoproducts' rotational line intensities is investigated for the effects of rotational and vibrational thermalization of energized photoproducts. Possible contributions from bimolecular and wall-mediated chemistry are evaluated as well.

Mental rotation and working memory in musicians' dystonia.

Science.gov (United States)

Erro, Roberto; Hirschbichler, Stephanie T; Ricciardi, Lucia; Ryterska, Agata; Antelmi, Elena; Ganos, Christos; Cordivari, Carla; Tinazzi, Michele; Edwards, Mark J; Bhatia, Kailash P

2016-11-01

Mental rotation of body parts engages cortical-subcortical areas that are actually involved in the execution of a movement. Musicians' dystonia is a type of focal hand dystonia that is grouped together with writer's cramp under the rubric of "occupational dystonia", but it is unclear to which extent these two disorders share common pathophysiological mechanisms. Previous research has demonstrated patients with writer's cramp to have deficits in mental rotation of body parts. It is unknown whether patients with musicians' dystonia would display similar deficits, reinforcing the concept of shared pathophysiology. Eight patients with musicians' dystonia and eight healthy musicians matched for age, gender and musical education, performed a number of tasks assessing mental rotation of body parts and objects as well as verbal and spatial working memories abilities. There were no differences between patients and healthy musicians as to accuracy and reaction times in any of the tasks. Patients with musicians' dystonia have intact abilities in mentally rotating body parts, suggesting that this disorder relies on a highly selective disruption of movement planning and execution that manifests only upon playing a specific instrument. We further demonstrated that mental rotation of body parts and objects engages, at least partially, different cognitive networks. Copyright © 2016 Elsevier Inc. All rights reserved.

Paleomagnetic constraints on the timing and distribution of Cenozoic rotations in Central and Eastern Anatolia

NARCIS (Netherlands)

Gürer, Derya; Van Hinsbergen, Douwe J.J.; Özkaptan, Murat; Creton, Iverna; Koymans, Mathijs R.; Cascella, Antonio; Langereis, Cornelis G.

2018-01-01

To quantitatively reconstruct the kinematic evolution of Central and Eastern Anatolia within the framework of Neotethyan subduction accommodating Africa-Eurasia convergence, we paleomagnetically assess the timing and amount of vertical axis rotations across the Uluklisla and Sivas regions. We show

Earth Rotation

Science.gov (United States)

Dickey, Jean O.

1995-01-01

The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

Inertial wave beams and inertial wave modes in a rotating cylinder with time-modulated rotation rate

Science.gov (United States)

Borcia, Ion D.; Ghasemi V., Abouzar; Harlander, Uwe

2014-05-01

Inertial gravity waves play an crucial role in atmospheres, oceans, and the fluid inside of planets and moons. In the atmosphere, the effect of rotation is neglected for small wavelength and the waves bear the character of internal gravity waves. For long waves, the hydrostatic assumption is made which in turn makes the atmosphere inelastic with respect to inertial motion. In contrast, in the Earth's interior, pure inertial waves are considered as an important fundamental part of the motion. Moreover, as the deep ocean is nearly homogeneous, there the inertial gravity waves bear the character of inertial waves. Excited at the oceans surface mainly due to weather systems the waves can propagate downward and influence the deep oceans motion. In the light of the aforesaid it is important to understand better fundamental inertial wave dynamics. We investigate inertial wave modes by experimental and numerical methods. Inertial modes are excited in a fluid filled rotating annulus by modulating the rotation rate of the outer cylinder and the upper and lower lids. This forcing leads to inertial wave beams emitted from the corner regions of the annulus due to periodic motions in the boundary layers (Klein et al., 2013). When the forcing frequency matches with the eigenfrequency of the rotating annulus the beam pattern amplitude is increasing, the beams broaden and mode structures can be observed (Borcia et al., 2013a). The eigenmodes are compared with analytical solutions of the corresponding inviscid problem (Borcia et al, 2013b). In particular for the pressure field a good agreement can be found. However, shear layers related to the excited wave beams are present for all frequencies. This becomes obvious in particular in the experimental visualizations that are done by using Kalliroscope particles, highlighting relative motion in the fluid. Comparing the eigenfrequencies we find that relative to the analytical frequencies, the experimental and numerical ones show a small

Superior glenoid inclination and rotator cuff tears.

Science.gov (United States)

Chalmers, Peter N; Beck, Lindsay; Granger, Erin; Henninger, Heath; Tashjian, Robert Z

2018-03-23

The objectives of this study were to determine whether glenoid inclination (1) could be measured accurately on magnetic resonance imaging (MRI) using computed tomography (CT) as a gold standard, (2) could be measured reliably on MRI, and (3) whether it differed between patients with rotator cuff tears and age-matched controls without evidence of rotator cuff tears or glenohumeral osteoarthritis. In this comparative retrospective radiographic study, we measured glenoid inclination on T1 coronal MRI corrected into the plane of the scapula. We determined accuracy by comparison with CT and inter-rater reliability. We compared glenoid inclination between patients with full-thickness rotator cuff tears and patients aged >50 years without evidence of a rotator cuff tear or glenohumeral arthritis. An a priori power analysis determined adequate power to detect a 2° difference in glenoid inclination. (1) In a validation cohort of 37 patients with MRI and CT, the intraclass correlation coefficient was 0.877, with a mean difference of 0° (95% confidence interval, -1° to 1°). (2) For MRI inclination, the inter-rater intraclass correlation coefficient was 0.911. (3) Superior glenoid inclination was 2° higher (range, 1°-4°, P rotator cuff tear group of 192 patients than in the control cohort of 107 patients. Glenoid inclination can be accurately and reliably measured on MRI. Although superior glenoid inclination is statistically greater in those with rotator cuff tears than in patients of similar age without rotator cuff tears or glenohumeral arthritis, the difference is likely below clinical significance. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Aging in a Relativistic Biological Space-Time

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Davide Maestrini

2018-05-01

Full Text Available Here we present a theoretical and mathematical perspective on the process of aging. We extend the concepts of physical space and time to an abstract, mathematically-defined space, which we associate with a concept of “biological space-time” in which biological dynamics may be represented. We hypothesize that biological dynamics, represented as trajectories in biological space-time, may be used to model and study different rates of biological aging. As a consequence of this hypothesis, we show how dilation or contraction of time analogous to relativistic corrections of physical time resulting from accelerated or decelerated biological dynamics may be used to study precipitous or protracted aging. We show specific examples of how these principles may be used to model different rates of aging, with an emphasis on cancer in aging. We discuss how this theory may be tested or falsified, as well as novel concepts and implications of this theory that may improve our interpretation of biological aging.

Differential rotation of viscous neutron matter

International Nuclear Information System (INIS)

Nitsch, J.; Pfarr, J.; Heintzmann, H.

1976-08-01

The reaction of homogeneous sphere of neutron matter set in rotational motion under the influence of an external torque acting on its surface is investigated. For neutron matter with a typical neutron star density of 10 15 gcm -3 and a temperature varying between 10 6 and 10 9 K originally in uniform rotation, a time dependent differential motion sets in, which lasts a time scale of hours to some decades, resulting finally in co-rotation. During these times the braking index of a magnetic neutron sphere very sensitively depends on time

Natural History of Rotator Cuff Disease and Implications on Management

Science.gov (United States)

Hsu, Jason

2015-01-01

Degenerative rotator cuff disease is commonly associated with ageing and is often asymptomatic. The factors related to tear progression and pain development are just now being defined through longitudinal natural history studies. The majority of studies that follow conservatively treated painful cuff tears or asymptomatic tears that are monitored at regular intervals show slow progression of tear enlargement and muscle degeneration over time. These studies have highlighted greater risks for disease progression for certain variables, such as the presence of a full-thickness tear and involvement of the anterior aspect supraspinatus tendon. Coupling the knowledge of the natural history of degenerative cuff tear progression with variables associated with greater likelihood of successful tendon healing following surgery will allow better refinement of surgical indications for rotator cuff disease. In addition, natural history studies may better define the risks of nonoperative treatment over time. This article will review pertinent literature regarding degenerative rotator cuff disease with emphasis on variables important to defining appropriate initial treatments and refining surgical indications. PMID:26726288

[Rotator cuff tear athropathy prevalence].

Science.gov (United States)

Guerra-Soriano, F; Encalada-Díaz, M I; Ruiz-Suárez, M; Valero-González, F S

2017-01-01

Glenohumeral arthritis secondary to massive rotator cuff tear presents with a superior displacement and femoralization of the humeral head with coracoacromial arch acetabularization. The purpose of this study was to establish prevalence of rotator cuff tear artropathy (CTA) at our institution. Four hundred electronic records were reviewed from which we identified 136 patients with rotator cuff tears. A second group was composed with patients with massive cuff tears that were analized and staged by the Seebauer cuff tear arthropathy classification. Thirty four patients with massive rotator cuff tears were identified, 8 male and 26 female (age 60.1 ± 10.26 years). Massive rotator cuff tear prevalence was 25%. CTA prevalence found in the rotator cuff group was 19 and 76% in the massive cuff tears group. Patients were staged according to the classification with 32% in stage 1a, 11% 1b, 32% 2a and 0% 2b. CTA prevalence in patients with rotator cuff tears and massive cuff tears is higher than the one reported in American population. We consider that a revision of the Seebauer classification to be appropriate to determine its reliability.

Regularity of the Rotation Number for the One-Dimensional Time-Continuous Schroedinger Equation

Energy Technology Data Exchange (ETDEWEB)

Amor, Sana Hadj, E-mail: sana_hadjamor@yahoo.fr [Ecole Nationale d' Ingenieurs de Monastir (Tunisia)

2012-12-15

Starting from results already obtained for quasi-periodic co-cycles in SL(2, R), we show that the rotation number of the one-dimensional time-continuous Schroedinger equation with Diophantine frequencies and a small analytic potential has the behavior of a 1/2-Hoelder function. We give also a sub-exponential estimate of the length of the gaps which depends on its label given by the gap-labeling theorem.

Rotating night shift work and physical activity of nurses and midwives in the cross-sectional study in Łódź, Poland.

Science.gov (United States)

Peplonska, Beata; Bukowska, Agnieszka; Sobala, Wojciech

2014-12-01

Shift work have been thought to restrict participation in leisure time activities, but the knowledge about physical activity in rotating night shift nurses has been limited so far. We investigated the associations between the rotating night shift work and physical activity using data from a cross-sectional study among nurses and midwives. This study included 354 nurses and midwives (aged 40-60) currently working rotating night shifts and 371 ones working days only. The information on the work characteristics and potential covariates was collected via a personal interview. Weight and height were measured and BMI was calculated. Physical activity was assessed according to the international questionnaire on physical activity - IPAQ, and four domains: leisure time, occupational, transport related and household were analyzed. Women who reported none leisure time activity were defined as recreationally "inactive". The associations were examined with multiple linear or logistic regression models adjusted for age, season of the year, number of full term births, marital status and BMI. Total and occupational physical activity was significantly higher among nurses working rotating night shifts. However, leisure time activity was significantly affected among rotating night shift nurses and midwives, compared to women working during the days only, with increased odds ratio for recreational "inactivity" (OR = 1.57, 95% CI: 1.11-2.20). Rotating night shift work among nurses and midwives is associated with higher occupational physical activity but lower leisure time activity. Initiatives supporting exercising among night shift workers are recommended.

Estimating the implicit component of visuomotor rotation learning by constraining movement preparation time.

Science.gov (United States)

Leow, Li-Ann; Gunn, Reece; Marinovic, Welber; Carroll, Timothy J

2017-08-01

When sensory feedback is perturbed, accurate movement is restored by a combination of implicit processes and deliberate reaiming to strategically compensate for errors. Here, we directly compare two methods used previously to dissociate implicit from explicit learning on a trial-by-trial basis: 1 ) asking participants to report the direction that they aim their movements, and contrasting this with the directions of the target and the movement that they actually produce, and 2 ) manipulating movement preparation time. By instructing participants to reaim without a sensory perturbation, we show that reaiming is possible even with the shortest possible preparation times, particularly when targets are narrowly distributed. Nonetheless, reaiming is effortful and comes at the cost of increased variability, so we tested whether constraining preparation time is sufficient to suppress strategic reaiming during adaptation to visuomotor rotation with a broad target distribution. The rate and extent of error reduction under preparation time constraints were similar to estimates of implicit learning obtained from self-report without time pressure, suggesting that participants chose not to apply a reaiming strategy to correct visual errors under time pressure. Surprisingly, participants who reported aiming directions showed less implicit learning according to an alternative measure, obtained during trials performed without visual feedback. This suggests that the process of reporting can affect the extent or persistence of implicit learning. The data extend existing evidence that restricting preparation time can suppress explicit reaiming and provide an estimate of implicit visuomotor rotation learning that does not require participants to report their aiming directions. NEW & NOTEWORTHY During sensorimotor adaptation, implicit error-driven learning can be isolated from explicit strategy-driven reaiming by subtracting self-reported aiming directions from movement directions, or

Hawking fluxes and anomalies in rotating regular black holes with a time-delay

International Nuclear Information System (INIS)

Takeuchi, Shingo

2016-01-01

Based on the anomaly cancellation method we compute the Hawking fluxes (the Hawking thermal flux and the total flux of energy-momentum tensor) from a four-dimensional rotating regular black hole with a time-delay. To this purpose, in the three metrics proposed in [1], we try to perform the dimensional reduction in which the anomaly cancellation method is feasible at the near-horizon region in a general scalar field theory. As a result we can demonstrate that the dimensional reduction is possible in two of those metrics. Hence we perform the anomaly cancellation method and compute the Hawking fluxes in those two metrics. Our Hawking fluxes involve three effects: (1) quantum gravity effect regularizing the core of the black holes, (2) rotation of the black hole, (3) time-delay. Further in this paper toward the metric in which the dimensional could not be performed, we argue that it would be some problematic metric, and mention its cause. The Hawking fluxes we compute in this study could be considered to correspond to more realistic Hawking fluxes. Further what Hawking fluxes can be obtained from the anomaly cancellation method would be interesting in terms of the relation between a consistency of quantum field theories and black hole thermodynamics. (paper)

Rotating quantum states

International Nuclear Information System (INIS)

Ambruş, Victor E.; Winstanley, Elizabeth

2014-01-01

We revisit the definition of rotating thermal states for scalar and fermion fields in unbounded Minkowski space–time. For scalar fields such states are ill-defined everywhere, but for fermion fields an appropriate definition of the vacuum gives thermal states regular inside the speed-of-light surface. For a massless fermion field, we derive analytic expressions for the thermal expectation values of the fermion current and stress–energy tensor. These expressions may provide qualitative insights into the behaviour of thermal rotating states on more complex space–time geometries

Degenerative full thickness rotator cuff tears : Towards optimal management

NARCIS (Netherlands)

Lambers Heerspink, Frederik

2016-01-01

The shoulder is one of the most complex joints in the body. Besides a wide range of motion it also has to be stable. The rotator cuff is a major stabiliser of the glenohumoral joint. With increasing age rotator cuff tears are common. Successful treatment is described following surgical (rotator cuff

Flow past a rotating cylinder

Science.gov (United States)

Mittal, Sanjay; Kumar, Bhaskar

2003-02-01

Flow past a spinning circular cylinder placed in a uniform stream is investigated via two-dimensional computations. A stabilized finite element method is utilized to solve the incompressible Navier Stokes equations in the primitive variables formulation. The Reynolds number based on the cylinder diameter and free-stream speed of the flow is 200. The non-dimensional rotation rate, [alpha] (ratio of the surface speed and freestream speed), is varied between 0 and 5. The time integration of the flow equations is carried out for very large dimensionless time. Vortex shedding is observed for [alpha] cylinder. The results from the stability analysis for the rotating cylinder are in very good agreement with those from direct numerical simulations. For large rotation rates, very large lift coefficients can be obtained via the Magnus effect. However, the power requirement for rotating the cylinder increases rapidly with rotation rate.

Initial results of shoulder MRI in external rotation after primary shoulder dislocation and after immobilization in external rotation

International Nuclear Information System (INIS)

Pennekamp, W.; Nicolas, V.; Gekle, C.; Seybold, D.

2006-01-01

Purpose: A change in the strategy for treating primary anterior traumatic dislocation of the shoulder has occurred. To date, brief fixation of internal rotation via a Gilchrist bandage has been used. Depending on the patient's age, a redislocation is seen in up to 90% of cases. This is due to healing of the internally rotated labrum-ligament tear in an incorrect position. In the case of external rotation of the humerus, better repositioning of the labrum ligament complex is achieved. Using MRI of the shoulder in external rotation, the extent of the improved labrum-ligament adjustment can be documented, and the indication of immobilization of the shoulder in external rotation can be derived. The aim of this investigation is to describe the degree of position changing of the labrum-ligament tear in internal and external rotation. Materials and Methods: 10 patients (9 male, 1 female, mean age 30.4 years, range 15-43 years) with a primary anterior dislocation of the shoulder without hyper laxity of the contra lateral side and labrum-ligament lesion substantiated by MRI were investigated using a standard shoulder MRI protocol (PD-TSE axial fs, PD-TSE coronar fs, T2-TSE sagittal, T1-TSE coronar) by an axial PD-TSE sequence in internal and external rotation. The dislocation and separation of the anterior labrum-ligament complex were measured. The shoulders were immobilized in 10 external rotation for 3 weeks. After 6 weeks a shoulder MRI in internal rotation was performed. Results: In all patients there was a significantly better position of the labrum-ligament complex of the inferior rim in external rotation, because of the tension of the ventral capsule and the subscapular muscle. In the initial investigation, the separation of the labrum-ligament complex in internal rotation was 0.44±0.27 mm and the dislocation was 0.45±0.33 mm. In external rotation the separation was 0.01±0.19 mm and the dislocation was -0.08±0.28 mm. After 6 weeks of immobilization in 10 external

Russian State Time and Earth Rotation Service: Observations, Eop Series, Prediction

Science.gov (United States)

Kaufman, M.; Pasynok, S.

2010-01-01

Russian State Time, Frequency and Earth Rotation Service provides the official EOP data and time for use in scientific, technical and metrological works in Russia. The observations of GLONASS and GPS on 30 stations in Russia, and also the Russian and worldwide observations data of VLBI (35 stations) and SLR (20 stations) are used now. To these three series of EOP the data calculated in two other Russian analysis centers are added: IAA (VLBI, GPS and SLR series) and MCC (SLR). Joint processing of these 7 series is carried out every day (the operational EOP data for the last day and the predicted values for 50 days). The EOP values are weekly refined and systematic errors of every individual series are corrected. The combined results become accessible on the VNIIFTRI server (ftp.imvp.ru) approximately at 6h UT daily.

Hand-operated and rotary ProTaper instruments: a comparison of working time and number of rotations in simulated root canals.

Science.gov (United States)

Pasqualini, Damiano; Scotti, Nicola; Tamagnone, Lorenzo; Ellena, Federica; Berutti, Elio

2008-03-01

The aim of this study was to compare the effective shaping time and number of rotations required by an endodontist working with hand and rotary ProTaper instruments to completely shape simulated root canals. Eighty Endo Training Blocks (curved canal shape) were used. Manual preflaring was performed with K-Flexofiles #08-10-12-15-17 and #20 Nitiflex at a working length of 18 mm. Specimens were then randomly assigned to 2 different groups (n = 40); group 1 was shaped by using hand ProTaper and group 2 with ProTaper rotary. The number of rotations made in the canal and the effective time required to achieve complete canal shaping were recorded for each instrument. Differences between groups were analyzed with the nonparametric Mann-Whitney U test (P Hand ProTaper required significantly fewer rotations (P ProTaper, whereas the effective working time to fully shape the simulated canal was significantly higher (P hand ProTaper.

The Societal and Economic Value of Rotator Cuff Repair

Science.gov (United States)

Mather, Richard C.; Koenig, Lane; Acevedo, Daniel; Dall, Timothy M.; Gallo, Paul; Romeo, Anthony; Tongue, John; Williams, Gerald

2013-01-01

Background: Although rotator cuff disease is a common musculoskeletal problem in the United States, the impact of this condition on earnings, missed workdays, and disability payments is largely unknown. This study examines the value of surgical treatment for full-thickness rotator cuff tears from a societal perspective. Methods: A Markov decision model was constructed to estimate lifetime direct and indirect costs associated with surgical and continued nonoperative treatment for symptomatic full-thickness rotator cuff tears. All patients were assumed to have been unresponsive to one six-week trial of nonoperative treatment prior to entering the model. Model assumptions were obtained from the literature and data analysis. We obtained estimates of indirect costs using national survey data and patient-reported outcomes. Four indirect costs were modeled: probability of employment, household income, missed workdays, and disability payments. Direct cost estimates were based on average Medicare reimbursements with adjustments to an all-payer population. Effectiveness was expressed in quality-adjusted life years (QALYs). Results: The age-weighted mean total societal savings from rotator cuff repair compared with nonoperative treatment was $13,771 over a patient’s lifetime. Savings ranged from $77,662 for patients who are thirty to thirty-nine years old to a net cost to society of $11,997 for those who are seventy to seventy-nine years old. In addition, surgical treatment results in an average improvement of 0.62 QALY. Societal savings were highly sensitive to age, with savings being positive at the age of sixty-one years and younger. The estimated lifetime societal savings of the approximately 250,000 rotator cuff repairs performed in the U.S. each year was $3.44 billion. Conclusions: Rotator cuff repair for full-thickness tears produces net societal cost savings for patients under the age of sixty-one years and greater QALYs for all patients. Rotator cuff repair is cost

On the stability of rotational discontinuities

International Nuclear Information System (INIS)

Richter, P.; Scholer, M.

1989-01-01

The stability of symmetric rotational discontinuities in which the magnetic field rotates by 180 degree is investigated by means of a one-dimensional self-consistent hybrid code. Rotational discontinuities with an angle Θ > 45 degree between the discontinuity normal direction and the upstream magnetic field are found to be relatively stable. The discontinuity normal is in the x direction and the initial magnetic field has finite y component only in the transition region. In the case of the ion (left-handed) sense of rotation of the tangential magnetic field, the transition region does not broaden with time. In the case of the electron (right-handed) sense of rotation, a damped wavetrain builds up in the B y component downstream of the rotational discontinuity and the discontinuity broadens with time. Rotational discontinuities with smaller angles, Θ, are unstable. Examples for a rotational discontinuity with Θ = 30 degree and the electron sense of rotation as well as a rotational discontinuity with Θ = 15 degree and the ion sense of rotation show that these discontinuities into waves. These waves travel approximately with Alfven velocity in the upstream direction and are therefore phase standing in the simulation system. The magnetic hodograms of these disintegrated discontinuities are S-shaped. The upstream portion of the hodogram is always right-handed; the downstream portion is always left-handed

Comparison of rotational temperature derived from ground-based OH airglow observations with TIMED/SABER to evaluate the Einstein Coefficients

Science.gov (United States)

Liu, W.; Xu, J.; Smith, A. K.; Yuan, W.

2017-12-01

Ground-based observations of the OH(9-4, 8-3, 6-2, 5-1, 3-0) band airglows over Xinglong, China (40°24'N, 117°35'E) from December 2011 to 2014 are used to calculate rotational temperatures. The temperatures are calculated using five commonly used Einstein coefficient datasets. The kinetic temperature from TIMED/SABER is completely independent of the OH rotational temperature. SABER temperatures are weighted vertically by weighting functions calculated for each emitting vibrational state from two SABER OH volume emission rate profiles. By comparing the ground-based OH rotational temperature with SABER's, five Einstein coefficient datasets are evaluated. The results show that temporal variations of the rotational temperatures are well correlated with SABER's; the linear correlation coefficients are higher than 0.72, but the slopes of the fit between the SABER and rotational temperatures are not equal to 1. The rotational temperatures calculated using each set of Einstein coefficients produce a different bias with respect to SABER; these are evaluated over each of vibrational levels to assess the best match. It is concluded that rotational temperatures determined using any of the available Einstein coefficient datasets have systematic errors. However, of the five sets of coefficients, the rotational temperature derived with the Langhoff et al.'s (1986) set is most consistent with SABER. In order to get a set of optimal Einstein coefficients for rotational temperature derivation, we derive the relative values from ground-based OH spectra and SABER temperatures statistically using three year data. The use of a standard set of Einstein coefficients will be beneficial for comparing rotational temperatures observed at different sites.

Comparison of Clinical and Radiological Results in the Arthroscopic Repair of Full-Thickness Rotator Cuff Tears With and Without the Anterior Attachment of the Rotator Cable.

Science.gov (United States)

Cho, Nam Su; Moon, Seong Cheol; Hong, Se Jung; Bae, Seong Hae; Rhee, Yong Girl

2017-09-01

The anterior rotator cable is critical in force transmission of the rotator cuff. However, few clinical studies have examined the correlation between the integrity of the anterior supraspinatus tendon and surgical outcomes in patients with rotator cuff tears. To compare the clinical and structural outcomes of the arthroscopic repair of full-thickness rotator cuff tears with and without anterior disruption of the supraspinatus tendon. Cohort study; Level of evidence, 3. One hundred eighty-one shoulders available for magnetic resonance imaging (MRI) at least 6 months after arthroscopic rotator cuff repair, with a minimum 1-year follow-up, were enrolled. The anterior attachment of the rotator cable was disrupted in 113 shoulders (group A) and intact in 68 shoulders (group B). The mean age at the time of surgery in groups A and B was 59.6 and 59.2 years, respectively, and the mean follow-up period was 24.2 and 25.1 months, respectively. There were statistically significant differences in the preoperative tear size and pattern and muscle fatty degeneration between the 2 groups ( P = .004, P = .008, and P rotator cable, the mean 24-month follow-up demonstrated excellent pain relief and improvement in the ability to perform activities of daily living after arthroscopic rotator cuff repair. However, tears with anterior disruption of the rotator cable showed a significantly larger and more complex tear pattern and more advanced fatty degeneration. Additionally, the retear rate was significantly higher in patients with a tear involving the anterior attachment of the rotator cable.

Patient reported activities after reverse total shoulder arthroplasty in rotator cuff arthropathy patients.

Science.gov (United States)

Alcobía-Díaz, B; Lópiz, Y; García-Fernández, C; Rizo de Álvaro, B; Marco, F

Reverse total shoulder arthroplasty in rotator cuff arthropathy patients, improves anteversion and abduction, but not rotational, outcomes. The main aim of this study is to determine its repercussions on daily life activities in our patients. Between 2009 and 2011 we implanted 210 shoulder arthroplasties, 126 of them were reverse total shoulder arthroplasty in a rotator cuff arthropathy context. About 88% were women, with a mean age at time of surgery of 81 years, 95% were retired. The mean follow up was 53 months. The Constant scale, Visual Analogue Scale, Charlson Comorbidity Index, range of motion were measured for each patient and whether they could manage 40 daily life activities by means of a new questionnaire, classifying them according toshoulder functional demand. Mean normalized by sex and age Constant value was 81.2%. Mean Visual Analogue Scale and Charlson Index were 3.56 and 1.69 respectively. Improvement in anteversion and abduction, not in rotational range of motion. Limitation was found in low and high functional demand activities in 20% and 51% respectively, especially those which involved internal rotation. Reverse total shoulder arthroplasty treatment for RCA in the elderly, achieves adequate pain management and good functional outcomes. Nevertheless, an important risk of DLA limitation must be accepted in those which involve internal rotation or shoulder high functional demand. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Stellar rotation, dynamo, electromagnetic braking, age an lithium burning

International Nuclear Information System (INIS)

Schatzmann, E.

1989-01-01

After an introduction describing the problem and the observational tests of the theory a consistant model of the dynamo mechanism in rotating star is presented. This provides for the electromagnetic braking a law Ω ∼ (1.t/t c har) -3 / 4 , in good agreement with the observations. This rests on the hypothesis that the main contribution to the EM braking is due to the magnetic field present in bipolar magnetic spots at the surface of the stellar disk. The premain sequence EM braking provides an initial angular velocity on arrival on the main sequence which is slightly smaller than the angular velocity when the dynamo turns on. Starting the dynamo takes place when the level at which the (αΩ) dynamo number becomes larger than one drops below the ionization level of hydrogen. Before that time, the surface dynamo mechanism would take place in a region of low ionization, where the magnetic Reynods number is so small that dissipation overtakes the building of the magnetic field. Turbulent mixing with a turbulent diffusion coefficient proportional to Ω 2 provides a consistant picture of the time and mass dependance of the surface abundance of Lithium. When the level of Li-burning is sufficiently far from the bottom of the convective zone an asymptotic value of lithium abundance is reached. This can explain the anomalous Li abundance of pop.II stars. (author). 40 refs

Mental rotation and the human body: Children's inflexible use of embodiment mirrors that of adults.

Science.gov (United States)

Krüger, Markus; Ebersbach, Mirjam

2017-12-25

Adults' mental rotation performance with body-like stimuli is enhanced if these stimuli are anatomically compatible with a human body, but decreased by anatomically incompatible stimuli. In this study, we investigated these effects for kindergartners and first-graders: When asked to mentally rotate cube configurations attached with human body parts in an anatomically compatible way, allowing for the projection of a human body, children performed better than with pure cube combinations. By contrast, when body parts were attached in an anatomically incompatible way, disallowing the projection of a human body, children performed worse than with pure combinations. This experiment is of specific interest against the background of two different theoretical approaches concerning imagery and the motor system in development: One approach assumes an increasing integration of motor processes and imagery over time that enables older children and adults to requisition motor resources for imagery processes, while the other postulates that imagery stems from early sensorimotor processes in the first place, and is disentangled from it over time. The finding that children of the two age groups tested show exactly the same effects as adults when mentally rotating anatomically compatible and incompatible stimuli is interpreted in favour of the latter approach. Statement of contribution What is already known on this subject? In mental rotation, adults perform better when rotating anatomically possible stimuli as compared to rotating standard cube combinations. Performance is worse when rotating anatomically impossible stimuli. What does this study add? The present study shows that children's mental transformations mirror those of adults in these respects. In case of the anatomically impossible stimuli, this highlights an inflexible use of embodiment in both age groups. This is in line with the Piagetian assumption of imagery being based on sensorimotor processes. © 2017 The British

Differences in Risk Factors for Rotator Cuff Tears between Elderly Patients and Young Patients.

Science.gov (United States)

Watanabe, Akihisa; Ono, Qana; Nishigami, Tomohiko; Hirooka, Takahiko; Machida, Hirohisa

2018-02-01

It has been unclear whether the risk factors for rotator cuff tears are the same at all ages or differ between young and older populations. In this study, we examined the risk factors for rotator cuff tears using classification and regression tree analysis as methods of nonlinear regression analysis. There were 65 patients in the rotator cuff tears group and 45 patients in the intact rotator cuff group. Classification and regression tree analysis was performed to predict rotator cuff tears. The target factor was rotator cuff tears; explanatory variables were age, sex, trauma, and critical shoulder angle≥35°. In the results of classification and regression tree analysis, the tree was divided at age 64. For patients aged≥64, the tree was divided at trauma. For patients agedrotator cuff tears in this study. However, these risk factors showed different trends according to age group, not a linear relationship.

Subjective Age in Early Adolescence: Relationships with Chronological Age, Pubertal Timing, Desired Age, and Problem Behaviors

Science.gov (United States)

Hubley, Anita M.; Arim, Rubab G.

2012-01-01

Subjective age generally refers to the age that one feels. In a cross-sectional questionnaire study of 245 adolescents ages 10-14 years, we examined (a) whether, and when, a cross-over in subjective age occurs, (b) differences in subjective age among pubertal timing groups, (c) correlations between subjective age and each of desired age and five…

Rotating preventers

International Nuclear Information System (INIS)

Tangedahl, M.J.; Stone, C.R.

1992-01-01

This paper reports that recent changes in the oil and gas industry and ongoing developments in horizontal and underbalanced drilling necessitated development of a better rotating head. A new device called the rotating blowout preventer (RBOP) was developed by Seal-Tech. It is designed to replace the conventional rotating control head on top of BOP stacks and allows drilling operations to continue even on live (underbalanced) wells. Its low wear characteristics and high working pressure (1,500 psi) allow drilling rig crews to drill safely in slightly underbalanced conditions or handle severe well control problems during the time required to actuate other BOPs in the stack. Drilling with a RBOP allows wellbores to be completely closed in tat the drill floor rather than open as with conventional BOPs

Mid-rotation silviculture timing influences nitrogen mineralization of loblolly pine plantations in the mid-south USA

Science.gov (United States)

Michael A. Blazier; D. Andrew Scott; Ryan Coleman

2015-01-01

Intensively managed loblolly pine (Pinus taeda L.) plantations often develop nutrient deficiencies near mid-rotation. Common silvicultural treatments for improving stand nutrition at this stage include thinning, fertilization, and vegetation control. It is important to better understand the influence of timing fertilization and vegetation control...

Palaeomagnetic Constrains on the Timing and the Geographical Distribution of Tectonic Rotations in the Betic Chain, Southern Spain. A Review

Science.gov (United States)

Osete, M. L.; Villalain, J. J.; Pavon-Carrasco, F. J.; Palencia, A.

2009-05-01

The Betic Cordillera is the northern branch of the Betic-Rifean orogen, the westernmost segment of the Mediterranean Alpine orogenic system. Several palaeomagnetic studies have enhanced the important role that block rotations about vertical axes have played in the tectonic evolution of the region. In this work we present a review of published palaeomagnetic data. According with the rotational deformation, the Betics are divided into the central-western area and the eastern Betics. A sequence of rotations for the two regions is also proposed. In central and western Subbetics almost constant clockwise rotations of about 60 are documented in Jurassic limestones. The existence of a pervasive remagnetization of Jurassic limestones, which was coeval with the folding of the studied units and dated as post-Palaeogene, constrains the timing of tectonic rotations in western Subbetics. New palaeomagnetic data from Neogene sedimentary sequences in central Betics indicate that palaeomagnetic clockwise rotations continued after late Miocene. A similar pattern of 40 CW rotations occurred after 20-17 Ma was obtained from the study of the Ronda-Malaga peridotites (western Internal Betics). In eastern Subbetics a more heterogeneous pattern, including very high CW rotations has been observed. But recent rotational deformation in the Internal part of eastern Betics is CCW and related to the left-lateral strike-slip fault systems. Proposed kinematics models for the Betics are discussed under the light of the present available palaeomagnetic information.

Narayanaswamy's 1971 aging theory and material time

Science.gov (United States)

Dyre, Jeppe C.

2015-09-01

The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy's phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the "unique-triangles property" according to which any three points on the system's path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)].

Spectra and ages of blue stragglers

International Nuclear Information System (INIS)

Abt, H.A.

1985-01-01

A mechanism similar to Wheeler's quasi-homogeneous evolution and Finzi and Wolf's proposal for blue stragglers is proposed as the origin of the blue stragglers in intermediate-age clusters. Blue stragglers are stars whose positions in color-magnitude diagrams of open and globular clusters are significantly above the turn-off points and in the region of the (former) main sequence; they seem to represent a conflict with the general conclusion that all stars in a cluster originated at about the same time. It is concluded that there are at least two kinds of blue stragglers: (1) those stars of types about B3-A2 are primarily Ap stars and slow rotators, occur in the intermediate age clusters and remain in the main sequence region probably through magnetic mixing; and (2) the stars of type O6-B2 frequently have emission lines, are rapid rotators, occur in the young cluster, and remain in the main sequence region probably by rotational mixing. 30 references

Ultrasound determination of rotator cuff tear repairability

Science.gov (United States)

Tse, Andrew K; Lam, Patrick H; Walton, Judie R; Hackett, Lisa

2015-01-01

Background Rotator cuff repair aims to reattach the torn tendon to the greater tuberosity footprint with suture anchors. The present study aimed to assess the diagnostic accuracy of ultrasound in predicting rotator cuff tear repairability and to assess which sonographic and pre-operative features are strongest in predicting repairability. Methods The study was a retrospective analysis of measurements made prospectively in a cohort of 373 patients who had ultrasounds of their shoulder and underwent rotator cuff repair. Measurements of rotator cuff tear size and muscle atrophy were made pre-operatively by ultrasound to enable prediction of rotator cuff repairability. Tears were classified following ultrasound as repairable or irreparable, and were correlated with intra-operative repairability. Results Ultrasound assessment of rotator cuff tear repairability has a sensitivity of 86% (p tear size (p tear size ≥4 cm2 or anteroposterior tear length ≥25 mm indicated an irreparable rotator cuff tear. Conclusions Ultrasound assessment is accurate in predicting rotator cuff tear repairability. Tear size or anteroposterior tear length and age were the best predictors of repairability. PMID:27582996

The metastable dynamo model of stellar rotational evolution

International Nuclear Information System (INIS)

Brown, Timothy M.

2014-01-01

This paper introduces a new empirical model for the rotational evolution of Sun-like stars—those with surface convection zones and non-convective interior regions. Previous models do not match the morphology of observed (rotation period)-color diagrams, notably the existence of a relatively long-lived 'C-sequence' of fast rotators first identified by Barnes. This failure motivates the Metastable Dynamo Model (MDM) described here. The MDM posits that stars are born with their magnetic dynamos operating in a mode that couples very weakly to the stellar wind, so their (initially very short) rotation periods at first change little with time. At some point, this mode spontaneously and randomly changes to a strongly coupled mode, the transition occurring with a mass-dependent lifetime that is of the order of 100 Myr. I show that with this assumption, one can obtain good fits to observations of young clusters, particularly for ages of 150-200 Myr. Previous models and the MDM both give qualitative agreement with the morphology of the slower-rotating 'I-sequence' stars, but none of them have been shown to accurately reproduce the stellar-mass-dependent evolution of the I-sequence stars, especially for clusters older than a few hundred million years. I discuss observational experiments that can test aspects of the MDM, and speculate that the physics underlying the MDM may be related to other situations described in the literature, in which stellar dynamos may have a multi-modal character.

Vorticity vector-potential method based on time-dependent curvilinear coordinates for two-dimensional rotating flows in closed configurations

Science.gov (United States)

Fu, Yuan; Zhang, Da-peng; Xie, Xi-lin

2018-04-01

In this study, a vorticity vector-potential method for two-dimensional viscous incompressible rotating driven flows is developed in the time-dependent curvilinear coordinates. The method is applicable in both inertial and non-inertial frames of reference with the advantage of a fixed and regular calculation domain. The numerical method is applied to triangle and curved triangle configurations in constant and varying rotational angular velocity cases respectively. The evolutions of flow field are studied. The geostrophic effect, unsteady effect and curvature effect on the evolutions are discussed.

Sonographic Visualization of the Rotator Cable in Patients With Symptomatic Full-Thickness Rotator Cuff Tears: Correlation With Tear Size, Muscular Fatty Infiltration and Atrophy, and Functional Outcome.

Science.gov (United States)

Bureau, Nathalie J; Blain-Paré, Etienne; Tétreault, Patrice; Rouleau, Dominique M; Hagemeister, Nicola

2016-09-01

To assess the prevalence of sonographic visualization of the rotator cable in patients with symptomatic full-thickness rotator cuff tears and asymptomatic controls and to correlate rotator cable visualization with tear size, muscular fatty infiltration and atrophy, and the functional outcome in the patients with rotator cuff tears. Fifty-seven patients with rotator cuff tears and 30 asymptomatic volunteers underwent shoulder sonography for prospective assessment of the rotator cable and rotator cuff tear and responded to 2 functional outcome questionnaires (shortened Disabilities of the Arm, Shoulder, and Hand [QuickDASH] and Constant). In the patients with rotator cuff tears, appropriate tests were used to correlate rotator cable visualization with the tear size, functional outcome, muscular fatty infiltration, and atrophy. The patients with rotator cuff tears included 25 women and 32 men (mean age,57 years; range, 39-67 years), and the volunteers included 13 women and 17 men (mean age, 56 years; range, 35-64 years). The rotator cable was identified in 77% (23 of 30) of controls and 23% (13 of 57) of patients with rotator cuff tears. In the patients, nonvisualization of the rotator cable correlated with larger tears (P tears than asymptomatic controls and was associated with a larger tear size and greater supraspinatus fatty infiltration and atrophy. Diligent assessment of the supraspinatus muscle should be done in patients with rotator cuff tears without a visible rotator cable, as the integrity of these anatomic structures may be interdependent.

A correlative study of aortic valve rotation angle and thoracic aortic sizes using ECG gated CT angiography

Energy Technology Data Exchange (ETDEWEB)

Saremi, Farhood, E-mail: fsaremi@usc.edu; Cen, Steven; Tayari, Nazila; Alizadeh, Houman; Emami, Amir; Lin, Leah; Fleischman, Fernando

2017-04-15

Objective: Various degrees of aortic valve rotation may be seen in individuals with no history of congenital cardiovascular malformations, but its association with aortic sizes has not been studied. Methods: Gated computed tomographic (CT angiograms in 217 patients were studied (66.7 ± 15; 22–97 years old)). Aortic diameters were determined at 5 anatomic locations. The length of the aorta from sinus to left subclavian artery was measured. The angle of valve rotation was recorded by measuring the angle between a line connecting the midpoint of the non-coronary sinus to the anterior commissure and another line along the interatrial septum. Rotation angles were correlated with aortic measurements. Patients were separated into two groups based on aortic sizes and into three groups based on age. The threshold for aortic dilatation was set at maximum ascending aorta diameter ≥40 mm (≥21 mm body surface area [BSA] indexed). Results: No significant difference in rotation angles was seen between the three age groups or between genders. Rotation angles were significantly correlated with maximal, average, and BSA adjustment of the aortic root and ascending aortic measurements. The aortic root angles were significantly different between the dilated versus nondilated aortas. There was no significant association between the rotation angles and age, length of ascending aorta, or diameters of descending aorta. Multivariate adaptive regression splines showed 25° of aortic root rotation as the diagnostic cut off for ascending aorta dilation. Above the 25° rotation, every 10° of increasing rotation was associated with a 3.78 ± 0.87 mm increase in aortic diameter (p < 0.01) and a 1.73 ± 0.25 times increased risk for having a dilated aorta (p < 0.01). Conclusion: Rotation angles of the aortic valve may be an independent non-invasive imaging marker for dilatation of the ascending aorta. Patients with increased rotation angle of the aortic valve may have higher risk for

Relativistic rotation and the anholonomic object

International Nuclear Information System (INIS)

Corum, J.F.

1977-01-01

The purpose of this communication is to call attention to the conceptual economy provided by the object of anholonomity for the theory of relativity. This geometric object expresses certain consequences of relativity theory and provides a single, simple framework for discussing a variety of phenomena. It particularly clarifies the description of relativistic rotation. The relativistic rotational transformation of the four coordinate differentials of flat space--time generates a set of anholonomic, or inexact differentials, whose duals are an orthogonal set of basis vectors. How should a rotating observer interpret physical events referred to such orthogonal, but anholonomic frames The answer to this question rests upon the origin and physical significance of the object of anholonomity. It is demonstrated that not only is the rotational Lorentz transformation an anholonomic transformation, but that the intrinsic anholonomic effects are essential to interpreting rotational phenomena. In particular, the Sagnac effect may be interpreted as the physical manifestation of temporal anholonomity under rotation. The Thomas precession of a reference axis may be interpreted as a consequence of the spatial anholonomity of the rotating frame. Further, the full four-dimensional covariance of Maxwellian electrodynamics, under a relativistic Lorentz rotation, is possible only with the inclusion of anholonomic effects. The anholonomic approach clarifies the distinction between the physically different operations of source rotation and observer rotation in a flat space--time. It is finally concluded that a consistant theory of relativistic rotation, satisfying the principle of general covariance, inherently requires the presence of the object of anholonomity

No Effect of Assisted Hip Rotation on Bat Velocity.

Science.gov (United States)

Rivera, Michelle; Leyva, Whitney D; Archer, David C; Munger, Cameron N; Watkins, Casey M; Wong, Megan A; Dobbs, Ian J; Galpin, Andrew J; Coburn, Jared W; Brown, Lee E

2018-01-01

Softball and baseball are games that require multiple skill sets such as throwing, hitting and fielding. Players spend a copious amount of time in batting practice in order to be successful hitters. Variables commonly associated with successful hitting include bat velocity and torso rotation. The concept of overspeed bodyweight assistance (BWA) has shown increases in vertical jump and sprint times, but not hip rotation and batting. The purpose of this study was to examine the effects of assisted hip rotation on bat velocity. Twenty-one male and female recreational softball and baseball players (15 males, age 23.8 ± 3.1yrs; height 177.67 ± 6.71cm; body mass 85.38 ± 14.83kg; 6 females, age 21.5 ± 2.1yrs; height 162.20 ± 9.82cm; body mass 60.28 ± 9.72kg) volunteered to participate. Four different BWA conditions (0%, 10%, 20%, and 30%) were randomly applied and their effects on bat velocity were analyzed. Subjects performed three maximal effort swings under each condition in a custom measurement device and average bat velocity (MPH) was used for analysis. A mixed factor ANOVA revealed no interaction (p=0.841) or main effect for condition, but there was a main effect for sex where males had greater bat velocity (43.82±4.40 - 0% BWA, 41.52±6.09 - 10% BWA, 42.59±7.24 - 20% BWA, 42.69±6.42 - 30% BWA) than females (32.57±5.33 - 0% BWA, 31.69±3.40 - 10% BWA, 32.43±5.06 - 20% BWA, 32.08±4.83 - 30% BWA) across all conditions Using the concept of overspeed training with assisted hip rotation up to 30% BWA did not result in an increase in bat velocity. Future research should examine elastic band angle and hip translation at set-up.

No Effect of Assisted Hip Rotation on Bat Velocity

Science.gov (United States)

RIVERA, MICHELLE; LEYVA, WHITNEY D.; ARCHER, DAVID C.; MUNGER, CAMERON N.; WATKINS, CASEY M.; WONG, MEGAN A.; DOBBS, IAN J.; GALPIN, ANDREW J.; COBURN, JARED W.; BROWN, LEE E.

2018-01-01

Softball and baseball are games that require multiple skill sets such as throwing, hitting and fielding. Players spend a copious amount of time in batting practice in order to be successful hitters. Variables commonly associated with successful hitting include bat velocity and torso rotation. The concept of overspeed bodyweight assistance (BWA) has shown increases in vertical jump and sprint times, but not hip rotation and batting. The purpose of this study was to examine the effects of assisted hip rotation on bat velocity. Twenty-one male and female recreational softball and baseball players (15 males, age 23.8 ± 3.1yrs; height 177.67 ± 6.71cm; body mass 85.38 ± 14.83kg; 6 females, age 21.5 ± 2.1yrs; height 162.20 ± 9.82cm; body mass 60.28 ± 9.72kg) volunteered to participate. Four different BWA conditions (0%, 10%, 20%, and 30%) were randomly applied and their effects on bat velocity were analyzed. Subjects performed three maximal effort swings under each condition in a custom measurement device and average bat velocity (MPH) was used for analysis. A mixed factor ANOVA revealed no interaction (p=0.841) or main effect for condition, but there was a main effect for sex where males had greater bat velocity (43.82±4.40 - 0% BWA, 41.52±6.09 - 10% BWA, 42.59±7.24 - 20% BWA, 42.69±6.42 - 30% BWA) than females (32.57±5.33 - 0% BWA, 31.69±3.40 - 10% BWA, 32.43±5.06 - 20% BWA, 32.08±4.83 - 30% BWA) across all conditions Using the concept of overspeed training with assisted hip rotation up to 30% BWA did not result in an increase in bat velocity. Future research should examine elastic band angle and hip translation at set-up. PMID:29795730

A Simple and Efficient Numerical Method for Computing the Dynamics of Rotating Bose--Einstein Condensates via Rotating Lagrangian Coordinates

KAUST Repository

Bao, Weizhu

2013-01-01

We propose a simple, efficient, and accurate numerical method for simulating the dynamics of rotating Bose-Einstein condensates (BECs) in a rotational frame with or without longrange dipole-dipole interaction (DDI). We begin with the three-dimensional (3D) Gross-Pitaevskii equation (GPE) with an angular momentum rotation term and/or long-range DDI, state the twodimensional (2D) GPE obtained from the 3D GPE via dimension reduction under anisotropic external potential, and review some dynamical laws related to the 2D and 3D GPEs. By introducing a rotating Lagrangian coordinate system, the original GPEs are reformulated to GPEs without the angular momentum rotation, which is replaced by a time-dependent potential in the new coordinate system. We then cast the conserved quantities and dynamical laws in the new rotating Lagrangian coordinates. Based on the new formulation of the GPE for rotating BECs in the rotating Lagrangian coordinates, a time-splitting spectral method is presented for computing the dynamics of rotating BECs. The new numerical method is explicit, simple to implement, unconditionally stable, and very efficient in computation. It is spectral-order accurate in space and second-order accurate in time and conserves the mass on the discrete level. We compare our method with some representative methods in the literature to demonstrate its efficiency and accuracy. In addition, the numerical method is applied to test the dynamical laws of rotating BECs such as the dynamics of condensate width, angular momentum expectation, and center of mass, and to investigate numerically the dynamics and interaction of quantized vortex lattices in rotating BECs without or with the long-range DDI.Copyright © by SIAM.

Role of ultrasound in rotator cuff tears

International Nuclear Information System (INIS)

Siddiqi, H.A.; Mirza, T.

2010-01-01

The study was designed to evaluate the efficacy of ultrasound in rotator cuff tears and to compare it with MRI. Total number of patients was thirty. All of these were above thirty years of age and were referred by clinicians, with shoulder pain for diagnostic workup. Post operative patients were excluded. Ultrasound and Magnetic Resonance Imaging (MRI) were performed on each patient. Same operator performed ultrasound in all patients. Ultrasound (US) and Magnetic Resonance Imaging (MRI) detected equal number of full thickness tears while two partial thickness tears were missed on US. Hypoechoic defect was the most important primary sign while cortical irregularity and fluid in subacromial and subdeltroid busra were the most important secondary signs on US. US was equally effective to MRI in detection of rotator cuff tears. It should be the primary investigation because of its availability, cost effective and real time evaluation provided significant expertise is developed, as it is highly operator dependent. (author)

Time evolution of some quantum-mechanical systems. Wavefunction cloning in evolving rotating systems. Finite range boundary conditions for time dependent Schroedinger Equation

International Nuclear Information System (INIS)

Arvieu, R.; Carbonell, J.; Gignoux, C.; Mangin-Brinet, M.; Rozmej, P.

1997-01-01

The time evolution of coherent rotational wave packets associated to a diatomic molecule or to a deformed nucleus has been studied. Assuming a rigid body dynamics the J(J+1) law leads to a mechanism of cloning: the way function is divided into wave packets identical to the initial one at specific time. Applications are studied for a nuclear wave packed formed by Coulomb excitation. Exact boundary conditions at finite distance for the solution of the time-dependent Schroedinger equation are derived. A numerical scheme based on Crank-Nicholson method is proposed to illustrate its applicability in several examples. (authors)

Three-dimensional motion of the uncovertebral joint during head rotation.

Science.gov (United States)

Nagamoto, Yukitaka; Ishii, Takahiro; Iwasaki, Motoki; Sakaura, Hironobu; Moritomo, Hisao; Fujimori, Takahito; Kashii, Masafumi; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

2012-10-01

The uncovertebral joints are peculiar but clinically important anatomical structures of the cervical vertebrae. In the aged or degenerative cervical spine, osteophytes arising from an uncovertebral joint can cause cervical radiculopathy, often necessitating decompression surgery. Although these joints are believed to bear some relationship to head rotation, how the uncovertebral joints work during head rotation remains unclear. The purpose of this study is to elucidate 3D motion of the uncovertebral joints during head rotation. Study participants were 10 healthy volunteers who underwent 3D MRI of the cervical spine in 11 positions during head rotation: neutral (0°) and 15° increments to maximal head rotation on each side (left and right). Relative motions of the cervical spine were calculated by automatically superimposing a segmented 3D MR image of the vertebra in the neutral position over images of each position using the volume registration method. The 3D intervertebral motions of all 10 volunteers were standardized, and the 3D motion of uncovertebral joints was visualized on animations using data for the standardized motion. Inferred contact areas of uncovertebral joints were also calculated using a proximity mapping technique. The 3D animation of uncovertebral joints during head rotation showed that the joints alternate between contact and separation. Inferred contact areas of uncovertebral joints were situated directly lateral at the middle cervical spine and dorsolateral at the lower cervical spine. With increasing angle of rotation, inferred contact areas increased in the middle cervical spine, whereas areas in the lower cervical spine slightly decreased. In this study, the 3D motions of uncovertebral joints during head rotation were depicted precisely for the first time.

Stationary axially symmetric perturbations of a rotating black hole. [Space-time perturbation, Newman-Penrose formalism

Energy Technology Data Exchange (ETDEWEB)

Demianski, M [California Inst. of Tech., Pasadena (USA)

1976-07-01

A stationary axially symmetric perturbation of a rotating black hole due to a distribution of test matter is investigated. The Newman-Penrose spin coefficient formalism is used to derive a general set of equations describing the perturbed space-time. In a linear approximation it is shown that the mass and angular momentum of a rotating black hole is not affected by the perturbation. The metric perturbations near the horizon are given. It is concluded that given a perturbing test fluid distribution, one can always find a corresponding metric perturbation such that the mass and angular momentum of the black hole are not changed. It was also noticed that when a tends to M, those perturbed spin coefficients and components of the Weyl tensor which determine the intrinsic properties of the incoming null cone near the horizon grow indefinitely.

Shoulder Strength Requirements for Upper Limb Functional Tasks: Do Age and Rotator Cuff Tear Status Matter?

Science.gov (United States)

Santago, Anthony C; Vidt, Meghan E; Li, Xiaotong; Tuohy, Christopher J; Poehling, Gary G; Freehill, Michael T; Saul, Katherine R

2017-12-01

Understanding upper limb strength requirements for daily tasks is imperative for early detection of strength loss that may progress to disability due to age or rotator cuff tear. We quantified shoulder strength requirements for 5 upper limb tasks performed by 3 groups: uninjured young adults and older adults, and older adults with a degenerative supraspinatus tear prior to repair. Musculoskeletal models were developed for each group representing age, sex, and tear-related strength losses. Percentage of available strength used was quantified for the subset of tasks requiring the largest amount of shoulder strength. Significant differences in strength requirements existed across tasks: upward reach 105° required the largest average strength; axilla wash required the largest peak strength. However, there were limited differences across participant groups. Older adults with and without a tear used a larger percentage of their shoulder elevation (p functional tasks to effectively detect early strength loss, which may lead to disability.

TIME-SERIES PHOTOMETRY OF STARS IN AND AROUND THE LAGOON NEBULA. I. ROTATION PERIODS OF 290 LOW-MASS PRE-MAIN-SEQUENCE STARS IN NGC 6530

International Nuclear Information System (INIS)

Henderson, Calen B.; Stassun, Keivan G.

2012-01-01

We have conducted a long-term, wide-field, high-cadence photometric monitoring survey of ∼50,000 stars in the Lagoon Nebula H II region. This first paper presents rotation periods for 290 low-mass stars in NGC 6530, the young cluster illuminating the nebula, and for which we assemble a catalog of infrared and spectroscopic disk indicators, estimated masses and ages, and X-ray luminosities. The distribution of rotation periods we measure is broadly uniform for 0.5 days X /L bol ≈ –3.3). However, we find a significant positive correlation between L X /L bol and corotation radius, suggesting that the observed X-ray luminosities are regulated by centrifugal stripping of the stellar coronae. The period-mass relationship in NGC 6530 is broadly similar to that of the Orion Nebula Cluster (ONC), but the slope of the relationship among the slowest rotators differs from that in the ONC and other young clusters. We show that the slope of the period-mass relationship for the slowest rotators can be used as a proxy for the age of a young cluster, and we argue that NGC 6530 may be slightly younger than the ONC, making it a particularly important touchstone for models of angular momentum evolution in young, low-mass stars.

Rotated balance in humans due to repetitive rotational movement

Science.gov (United States)

Zakynthinaki, M. S.; Madera Milla, J.; López Diaz De Durana, A.; Cordente Martínez, C. A.; Rodríguez Romo, G.; Sillero Quintana, M.; Sampedro Molinuevo, J.

2010-03-01

We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic "asymmetric" elite athletes and to a "symmetric" elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.

INTERNAL-CYCLE VARIATION OF SOLAR DIFFERENTIAL ROTATION

International Nuclear Information System (INIS)

Li, K. J.; Xie, J. L.; Shi, X. J.

2013-01-01

The latitudinal distributions of the yearly mean rotation rates measured by Suzuki in 1998 and 2012 and Pulkkinen and Tuominen in 1998 are utilized to investigate internal-cycle variation of solar differential rotation. The rotation rate at the solar equator seems to have decreased since cycle 10 onward. The coefficient B of solar differential rotation, which represents the latitudinal gradient of rotation, is found to be smaller in the several years after the minimum of a solar cycle than in the several years after the maximum time of the cycle, and it peaks several years after the maximum time of the solar cycle. The internal-cycle variation of the solar rotation rates looks similar in profile to that of the coefficient B. A new explanation is proposed to address such a solar-cycle-related variation of the solar rotation rates. Weak magnetic fields may more effectively reflect differentiation at low latitudes with high rotation rates than at high latitudes with low rotation rates, and strong magnetic fields may more effectively repress differentiation at relatively low latitudes than at high latitudes. The internal-cycle variation is inferred as the result of both the latitudinal migration of the surface torsional pattern and the repression of strong magnetic activity in differentiation.

Magnetic cycles and rotation periods of late-type stars from photometric time series

Science.gov (United States)

Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.

2016-10-01

Aims: We investigate the photometric modulation induced by magnetic activity cycles and study the relationship between rotation period and activity cycle(s) in late-type (FGKM) stars. Methods: We analysed light curves, spanning up to nine years, of 125 nearby stars provided by the All Sky Automated Survey (ASAS). The sample is mainly composed of low-activity, main-sequence late-A to mid-M-type stars. We performed a search for short (days) and long-term (years) periodic variations in the photometry. We modelled the light curves with combinations of sinusoids to measure the properties of these periodic signals. To provide a better statistical interpretation of our results, we complement our new results with results from previous similar works. Results: We have been able to measure long-term photometric cycles of 47 stars, out of which 39 have been derived with false alarm probabilities (FAP) of less than 0.1 per cent. Rotational modulation was also detected and rotational periods were measured in 36 stars. For 28 stars we have simultaneous measurements of activity cycles and rotational periods, 17 of which are M-type stars. We measured both photometric amplitudes and periods from sinusoidal fits. The measured cycle periods range from 2 to 14 yr with photometric amplitudes in the range of 5-20 mmag. We found that the distribution of cycle lengths for the different spectral types is similar, as the mean cycle is 9.5 yr for F-type stars, 6.7 yr for G-type stars, 8.5 yr for K-type stars, 6.0 yr for early M-type stars, and 7.1 yr for mid-M-type stars. On the other hand, the distribution of rotation periods is completely different, trending to longer periods for later type stars, from a mean rotation of 8.6 days for F-type stars to 85.4 days in mid-M-type stars. The amplitudes induced by magnetic cycles and rotation show a clear correlation. A trend of photometric amplitudes with rotation period is also outlined in the data. The amplitudes of the photometric variability

Do overhead sports increase risk for rotator cuff tears in wheelchair users?

Science.gov (United States)

Akbar, Michael; Brunner, Manuela; Ewerbeck, Volker; Wiedenhöfer, Bernd; Grieser, Thomas; Bruckner, Thomas; Loew, Markus; Raiss, Patric

2015-03-01

To analyze whether frequent overhead-sports activity increases the risk for rotator cuff disease in patients with spinal cord injuries (SCIs) who are wheelchair dependent. Cross-sectional study, risk analysis. Department of Orthopaedic Surgery, Trauma Surgery and Spinal Cord Injury. Patients (N=296) with SCI requiring the full-time use of a manual wheelchair were recruited for this study. The total population was divided into 2 groups (sports vs no sports), among them 103 patients playing overhead sports on a regular basis (at least 1-2 times/wk) and 193 patients involved in overhead sports less than once a week or in no sports activity at all. The mean age of the sports group was 49.1 years. The mean duration of wheelchair dependence was 26.5 years. The mean age of the no-sports group was 48 years. The mean duration of wheelchair dependence was 25.2 years. Each individual completed a questionnaire designed to identify overhead-sports activity on a regular basis and was asked about shoulder problems. Magnetic resonance imaging scans of both shoulders were performed in each patient and analyzed in a standardized fashion. None. Possible differences in continuous data between patients with and without rotator cuff tear were evaluated. The relative risk of suffering from a rotator cuff tear between patients playing overhead sports and those not playing overhead sports was calculated. One hundred three patients played overhead sports regularly and 193 did not. There was no difference between groups regarding age, sex, level of SCI, and duration of wheelchair dependence. The body mass index was significantly lower in the sports group than in the no-sports group (Psports group and in 36.3% of the patients in the no-sports group (Psports group to develop rotator cuff tears was twice as high as for the no-sports group (95% confidence interval, 1.7-2.6; Psports activities have been identified as an additional risk factor, along with age and duration of wheelchair dependence

[Surgical treatment of pronation and supination external rotation trimalleolar fractures].

Science.gov (United States)

Xu, Ye-qing; Zhan, Bei-lei; He, Fei-xiong; Wei, Hong-da

2008-04-01

To explore the operative method and its clinical effects of pronation and supination external rotation trimalleolar fractures. From March 2000 to July 2006,42 patients of the pronation and supination external rotation trimalleolar fractures treated with open reduction and internal fixation. Thirty-one were males and 11 were females,with an average age of 40.5 years (from 19 to 76 years). Four cases were open fractures and 38 cases close fractures. The fractures were classified as pronation-external rotation (grade IV) injury in 18 cases and supination-external rotation (grade IV)in 24 cases according to the system of Lauge-Hansen. The time of injury to operation was 2 hours to 27 days. The medial, lateral and posterior malleolus were exposed by standard anteromedial and Gatellier-Chastang approaches. The reduction and internal fixation started with the posterior,then the medial and the lateral malleolus and distal tibiofibular syndesmosis in sequence. The anteroposterior, lateral and mostise X-ray films were taken after operation. All the patients were followed up for an average time of 13.5 months(from 6 to 24 months). The time of union was from 12 to 16 weeks. The results were excellent in 20,good in 16, fair in 4 and poor in 2 cases according to Baird-Jackson ankle scoring system based on pain, stability, walking ability,range of motion and radiological manifestations. The excellent and good rate was 85.7%. There were no infection,malunion and nonunion of the fractures except that the inserted screw to distal tibiofibular syndesmosis was broken in 1 case. The key of operative treatment is to restore the anatomy of ankle and to regain the ankle function maximally.

Investigating the effect of a targets time-varying doppler generating axis of rotation on isar image distortion

CSIR Research Space (South Africa)

Abdul Gaffar, MY

2007-10-01

Full Text Available , contributes to ISAR image blurring. Quaternion algebra is used to aid the characterisation of a time-varying Doppler generating axis of rotation on the migration through cross-range cells. Real motion data of a sailing yacht is used to examine the effects of 3...

Rotator Cuff Repair in Adolescent Athletes.

Science.gov (United States)

Azzam, Michael G; Dugas, Jeffrey R; Andrews, James R; Goldstein, Samuel R; Emblom, Benton A; Cain, E Lyle

2018-04-01

Rotator cuff tears are rare injuries in adolescents but cause significant morbidity if unrecognized. Previous literature on rotator cuff repairs in adolescents is limited to small case series, with few data to guide treatment. Adolescent patients would have excellent functional outcome scores and return to the same level of sports participation after rotator cuff repair but would have some difficulty with returning to overhead sports. Case series; Level of evidence 4. A retrospective search of the practice's billing records identified all patients participating in at least 1 sport who underwent rotator cuff repair between 2006 and 2014 with an age Rotator Cuff Index. Thirty-two consecutive adolescent athletes (28 boys and 4 girls) with a mean age of 16.1 years (range, 13.2-17.9 years) met inclusion criteria. Twenty-nine patients (91%) had a traumatic event, and 27 of these patients (93%) had no symptoms before the trauma. The most common single tendon injury was to the supraspinatus (21 patients, 66%), of which 2 were complete tendon tears, 1 was a bony avulsion of the tendon, and 18 were high-grade partial tears. Fourteen patients (56%) underwent single-row repair of their rotator cuff tear, and 11 (44%) underwent double-row repair. All subscapularis injuries were repaired in open fashion, while all other tears were repaired arthroscopically. Twenty-seven patients (84%) completed the outcome questionnaires at a mean 6.2 years after surgery (range, 2-10 years). The mean ASES score was 93 (range, 65-100; SD = 9); mean Western Ontario Rotator Cuff Index, 89% (range, 60%-100%; SD = 13%); and mean numeric pain rating, 0.3 (range, 0-3; SD = 0.8). Overall, 25 patients (93%) returned to the same level of play or higher. Among overhead athletes, 13 (93%) were able to return to the same level of play, but 8 (57%) were forced to change positions. There were no surgical complications, but 2 patients did undergo a subsequent operation. Surgical repair of high-grade partial

Paleomagnetism of Jurassic and Cretaceous rocks in central Patagonia: a key to constrain the timing of rotations during the breakup of southwestern Gondwana?

Science.gov (United States)

Geuna, Silvana E.; Somoza, Rubén; Vizán, Haroldo; Figari, Eduardo G.; Rinaldi, Carlos A.

2000-08-01

A paleomagnetic study in Jurassic and Cretaceous rocks from the Cañadón Asfalto basin, central Patagonia, indicates the occurrence of about 25-30° clockwise rotation in Upper Jurassic-lowermost Cretaceous rocks, whereas the overlying mid-Cretaceous rocks do not show evidence of rotation. This constrains the tectonic rotation to be related to a major regional unconformity in Patagonia, which in turn seems to be close in time with the early opening of the South Atlantic Ocean. The sense and probably the timing of this rotation are similar to those of other paleomagnetically detected rotations in different areas of southwestern Gondwana, suggesting a possible relationship between these and major tectonic processes related with fragmentation of the supercontinent. On the other hand, the mid-Cretaceous rocks in the region yield a paleopole located at Lat. 87° South, Long. 159° East, A95=3.8°. This pole position is consistent with coeval high-quality paleopoles of other plates when transferred to South American coordinates, implying it is an accurate determination of the Aptian (circa 116 Ma) geomagnetic field in South America.

Effects of Successive Rotation Regimes on Carbon Stocks in Eucalyptus Plantations in Subtropical China Measured over a Full Rotation.

Science.gov (United States)

Li, Xiaoqiong; Ye, Duo; Liang, Hongwen; Zhu, Hongguang; Qin, Lin; Zhu, Yuling; Wen, Yuanguang

2015-01-01

Plantations play an important role in carbon sequestration and the global carbon cycle. However, there is a dilemma in that most plantations are managed on short rotations, and the carbon sequestration capacities of these short-rotation plantations remain understudied. Eucalyptus has been widely planted in the tropics and subtropics due to its rapid growth, high adaptability, and large economic return. Eucalyptus plantations are primarily planted in successive rotations with a short rotation length of 6~8 years. In order to estimate the carbon-stock potential of eucalyptus plantations over successive rotations, we chose a first rotation (FR) and a second rotation (SR) stand and monitored the carbon stock dynamics over a full rotation from 1998 to 2005. Our results showed that carbon stock in eucalyptus trees (TC) did not significantly differ between rotations, while understory vegetation (UC) and soil organic matter (SOC) stored less carbon in the SR (1.01 vs. 2.76 Mg.ha(-1) and 70.68 vs. 81.08 Mg. ha(-1), respectively) and forest floor carbon (FFC) conversely stored more (2.80 vs. 2.34 Mg. ha(-1)). The lower UC and SOC stocks in the SR stand resulted in 1.13 times lower overall ecosystem carbon stock. Mineral soils and overstory trees were the two dominant carbon pools in eucalyptus plantations, accounting for 73.77%~75.06% and 20.50%~22.39%, respectively, of the ecosystem carbon pool. However, the relative contribution (to the ecosystem pool) of FFC stocks increased 1.38 times and that of UC decreased 2.30 times in the SR versus FR stand. These carbon pool changes over successive rotations were attributed to intensive successive rotation regimes of eucalyptus plantations. Our eight year study suggests that for the sustainable development of short-rotation plantations, a sound silvicultural strategy is required to achieve the best combination of high wood yield and carbon stock potential.

Effects of Successive Rotation Regimes on Carbon Stocks in Eucalyptus Plantations in Subtropical China Measured over a Full Rotation.

Directory of Open Access Journals (Sweden)

Xiaoqiong Li

Full Text Available Plantations play an important role in carbon sequestration and the global carbon cycle. However, there is a dilemma in that most plantations are managed on short rotations, and the carbon sequestration capacities of these short-rotation plantations remain understudied. Eucalyptus has been widely planted in the tropics and subtropics due to its rapid growth, high adaptability, and large economic return. Eucalyptus plantations are primarily planted in successive rotations with a short rotation length of 6~8 years. In order to estimate the carbon-stock potential of eucalyptus plantations over successive rotations, we chose a first rotation (FR and a second rotation (SR stand and monitored the carbon stock dynamics over a full rotation from 1998 to 2005. Our results showed that carbon stock in eucalyptus trees (TC did not significantly differ between rotations, while understory vegetation (UC and soil organic matter (SOC stored less carbon in the SR (1.01 vs. 2.76 Mg.ha(-1 and 70.68 vs. 81.08 Mg. ha(-1, respectively and forest floor carbon (FFC conversely stored more (2.80 vs. 2.34 Mg. ha(-1. The lower UC and SOC stocks in the SR stand resulted in 1.13 times lower overall ecosystem carbon stock. Mineral soils and overstory trees were the two dominant carbon pools in eucalyptus plantations, accounting for 73.77%~75.06% and 20.50%~22.39%, respectively, of the ecosystem carbon pool. However, the relative contribution (to the ecosystem pool of FFC stocks increased 1.38 times and that of UC decreased 2.30 times in the SR versus FR stand. These carbon pool changes over successive rotations were attributed to intensive successive rotation regimes of eucalyptus plantations. Our eight year study suggests that for the sustainable development of short-rotation plantations, a sound silvicultural strategy is required to achieve the best combination of high wood yield and carbon stock potential.

Rotational Angiography Based Three-Dimensional Left Atrial Reconstruction: A New Approach for Transseptal Puncture.

Science.gov (United States)

Koektuerk, Buelent; Yorgun, Hikmet; Koektuerk, Oezlem; Turan, Cem H; Gorr, Eduard; Horlitz, Marc; Turan, Ramazan G

2016-02-01

Rotational angiography is a well-known method for the three-dimensional (3-D) reconstruction of left atrium and pulmonary veins during left-sided atrial arrhythmia ablation procedures. In our study, we aimed to review our experience in transseptal puncture (TSP) using 3-D rotational angiography. We included a total of 271 patients who underwent atrial fibrillation ablation using cryoballoon. Rotational angiography was performed to get the three-dimensional left atrial and pulmonary vein reconstructions using cardiac C-arm computed tomography. The image reconstruction was made using the DynaCT Cardiac software (Siemens, Erlangen, Germany). The mean age of the study population was 61 ± 10 years. The indications for left atrial arrhythmia ablation were paroxysmal AF in 140 patients (52%) and persistent AF patients in 131 (48%) patients. The success rate of TSP using only rotational guidance was (264/271 patients, 97.4%). In the remaining seven patients, transesophageal guidance was used after the initial attempt due to thick interatrial septum in five patients and difficult TSP due to abnormal anatomy and mild pericardial effusion in the remaining two patients. Mean fluoroscopy dosage of the rotational angiography was 4896.4 ± 825.3 μGym(2). The mean time beginning from femoral vein puncture to TSP was 12.3 ± 5.5 min. TSP guided by rotational angiography is a safe and effective method. Our results indicate that integration of rotational angiographic images into the real-time fluoroscopy can guide the TSP during the procedure. © 2015 John Wiley & Sons Ltd.

Arthroscopic rotator cuff repair in elite rugby players.

Science.gov (United States)

Tambe, Amol; Badge, Ravi; Funk, Lennard

2009-01-01

Rugby is an increasingly popular collision sport. A wide spectrum of injuries can be sustained during training and match play. Rotator cuff injury is uncommon in contact sports and there is little published literature on the treatment of rotator cuff tears in rugby players. We therefore reviewed the results and functional outcomes of arthroscopic rotator cuff repair in elite rugby players. Eleven professional rugby players underwent arthroscopic rotator cuff repair at our hospital over a 2-year period. We collected data on these patients from the operative records. The patients were recalled for outcome scoring and ultrasound scans. There were seven rugby league players and four rugby union players, including six internationals. Their mean age was 25.7 years. All had had a traumatic episode during match play and could not return to the game after the injury. The mean time to surgery was 5 weeks. The mean width of the cuff tear was 1.8 cm. All were full- thickness cuff tears. Associated injuries included two Bankart lesions, one bony Bankart lesion, one posterior labral tear, and two 360 degrees labral tears. The biceps was involved in three cases. Two were debrided and a tenodesis was performed in one. Repair was with suture anchors. Following surgery, all patients underwent a supervised accelerated rehabilitation programme. The final follow-up was at 18 months (range: 6-31 months) post surgery. The Constant scores improved from 44 preoperatively to 99 at the last follow-up. The mean score at 3 months was 95. The Oxford shoulder score improved from 34 to 12, with the mean third month score being 18. The mean time taken to return to full match play at the preinjury level was 4.8 months. There were no complications in any of the patients and postoperative scans in nine patients confirmed that the repairs had healed. We conclude that full-thickness rotator cuff tears in the contact athlete can be addressed successfully by arthroscopic repair, with a rapid return to

Modified forest rotation lengths: Long-term effects on landscape-scale habitat availability for specialized species.

Science.gov (United States)

Roberge, Jean-Michel; Öhman, Karin; Lämås, Tomas; Felton, Adam; Ranius, Thomas; Lundmark, Tomas; Nordin, Annika

2018-03-15

We evaluated the long-term implications from modifying rotation lengths in production forests for four forest-reliant species with different habitat requirements. By combining simulations of forest development with habitat models, and accounting both for stand and landscape scale influences, we projected habitat availability over 150 years in a large Swedish landscape, using rotation lengths which are longer (+22% and +50%) and shorter (-22%) compared to current practices. In terms of mean habitat availability through time, species requiring older forest were affected positively by extended rotations, and negatively by shortened rotations. For example, the mean habitat area for the treecreeper Certhia familiaris (a bird preferring forest with larger trees) increased by 31% when rotations were increased by 22%, at a 5% cost to net present value (NPV) and a 7% decrease in harvested volume. Extending rotation lengths by 50% provided more habitat for this species compared to a 22% extension, but at a much higher marginal cost. In contrast, the beetle Hadreule elongatula, which is dependent on sun-exposed dead wood, benefited from shortened rather than prolonged rotations. Due to an uneven distribution of stand-ages within the landscape, the relative amounts of habitat provided by different rotation length scenarios for a given species were not always consistent through time during the simulation period. If implemented as a conservation measure, prolonging rotations will require long-term strategic planning to avoid future bottlenecks in habitat availability, and will need to be accompanied by complementary measures accounting for the diversity of habitats necessary for the conservation of forest biodiversity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Design of a real-time spectroscopic rotating compensator ellipsometer without systematic errors

Energy Technology Data Exchange (ETDEWEB)

Broch, Laurent, E-mail: laurent.broch@univ-lorraine.fr [Laboratoire de Chimie Physique-Approche Multi-echelle des Milieux Complexes (LCP-A2MC, EA 4632), Universite de Lorraine, 1 boulevard Arago CP 87811, F-57078 Metz Cedex 3 (France); Stein, Nicolas [Institut Jean Lamour, Universite de Lorraine, UMR 7198 CNRS, 1 boulevard Arago CP 87811, F-57078 Metz Cedex 3 (France); Zimmer, Alexandre [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary BP 47870, F-21078 Dijon Cedex (France); Battie, Yann; Naciri, Aotmane En [Laboratoire de Chimie Physique-Approche Multi-echelle des Milieux Complexes (LCP-A2MC, EA 4632), Universite de Lorraine, 1 boulevard Arago CP 87811, F-57078 Metz Cedex 3 (France)

2014-11-28

We describe a spectroscopic ellipsometer in the visible domain (400–800 nm) based on a rotating compensator technology using two detectors. The classical analyzer is replaced by a fixed Rochon birefringent beamsplitter which splits the incidence light wave into two perpendicularly polarized waves, one oriented at + 45° and the other one at − 45° according to the plane of incidence. Both emergent optical signals are analyzed by two identical CCD detectors which are synchronized by an optical encoder fixed on the shaft of the step-by-step motor of the compensator. The final spectrum is the result of the two averaged Ψ and Δ spectra acquired by both detectors. We show that Ψ and Δ spectra are acquired without systematic errors on a spectral range fixed from 400 to 800 nm. The acquisition time can be adjusted down to 25 ms. The setup was validated by monitoring the first steps of bismuth telluride film electrocrystallization. The results exhibit that induced experimental growth parameters, such as film thickness and volumic fraction of deposited material can be extracted with a better trueness. - Highlights: • High-speed rotating compensator ellipsometer equipped with 2 detectors. • Ellipsometric angles without systematic errors • In-situ monitoring of electrocrystallization of bismuth telluride thin layer • High-accuracy of fitted physical parameters.

Identifiability analysis of rotational diffusion tensor and electronic transition moments measured in time-resolved fluorescence depolarization experiment

International Nuclear Information System (INIS)

Szubiakowski, Jacek P.

2014-01-01

The subject of this paper is studies of the deterministic identifiability of molecular parameters, such as rotational diffusion tensor components and orientation of electronic transition moments, resulting from the time-resolved fluorescence anisotropy experiment. In the most general case considered, a pair of perpendicularly polarized emissions enables the unique determination of all the rotational diffusion tensor's principal components. The influence of the tensor's symmetry and the associated degeneration of its eigenvalues on the identifiability of the electronic transitions moments is systematically investigated. The analysis reveals that independently of the rotational diffusion tensor's symmetry, the transition moments involved in photoselection and emission processes cannot be uniquely identified without a priori information about their mutual orientation or their orientation with respect to the principal axes of the tensor. Moreover, it is shown that increasing the symmetry of the rotational diffusion tensor deteriorates the degree of the transition moments identifiability. To obtain these results analytically, a novel approach to solve bilinear system of equations for Markov parameters is applied. The effect of the additional information, obtained from fluorescence measurements for different molecular mobilities, to improve the identifiability at various levels of analysis is shown. The effectiveness and reliability of the target analysis method for experimental determination of the molecular parameters is also discussed

Grids of rotating stellar models with masses between 1.0 and 3.0 M⊙

International Nuclear Information System (INIS)

Yang Wu-Ming; Bi Shao-Lan; Meng Xiang-Cun

2013-01-01

We calculated a grid of evolutionary tracks of rotating models with masses between 1.0 and 3.0 M ⊙ and resolution δM ≤ 0.02 M ⊙ , which can be used to study the effects of rotation on stellar evolution and on the characteristics of star clusters. The value of ∼ 2.05 M ⊙ is a critical mass for the effects of rotation on stellar structure and evolution. For stars with M > 2.05 M ⊙ , rotation leads to an increase in the convective core and prolongs their lifetime on the main sequence (MS); rotating models evolve more slowly than non-rotating ones; the effects of rotation on the evolution of these stars are similar to those of convective core overshooting. However for stars with 1.1 < M/M ⊙ < 2.05, rotation results in a decrease in the convective core and shortens the duration of the MS stage; rotating models evolve faster than non-rotating ones. When the mass has values in the range ∼ 1.7–2.0 M ⊙ , the mixing caused by rotationally induced instabilities is not efficient; the hydrostatic effects dominate processes associated with the evolution of these stars. For models with masses between about 1.6 and 2.0 M ⊙ , rotating models always exhibit lower effective temperatures than non-rotating ones at the same age during the MS stage. For a given age, the lower the mass, the smaller the change in the effective temperature. Thus rotations could lead to a color spread near the MS turnoff in the color-magnitude diagram for intermediate-age star clusters

EVOLUTION OF ROTATIONAL VELOCITIES OF A-TYPE STARS

International Nuclear Information System (INIS)

Yang Wuming; Bi Shaolan; Tian Zhijia; Meng Xiangcun

2013-01-01

The equatorial velocity of A-type stars undergoes an acceleration in the first third of the main sequence (MS) stage, but the velocity decreases as if the stars were not undergoing any redistribution of angular momentum in the external layers in the last stage of the MS phase. Our calculations show that the acceleration and the decrease of the equatorial velocity can be reproduced by the evolution of the differential rotation zero-age MS model with the angular momentum transport caused by hydrodynamic instabilities during the MS stage. The acceleration results from the fact that the angular momentum stored in the interiors of the stars is transported outward. In the last stage, the core and the radiative envelope are uncoupling, and the rotation of the envelope is a quasi-solid rotation; the uncoupling and the expansion of the envelope indicate that the decrease of the equatorial velocity approximately follows the slope for the change in the equatorial velocity of the model without any redistribution of angular momentum. When the fractional age 0.3 ∼ MS ∼< 0.5, the equatorial velocity remains almost constant for stars whose central density increases with age in the early stage of the MS phase, while the velocity decreases with age for stars whose central density decreases with age in the early stage of the MS phase.

Outcome of Expedited Rotator Cuff Surgery in Injured Workers: Determinants of Successful Recovery.

Science.gov (United States)

Razmjou, Helen; Boljanovic, Dragana; Lincoln, Sandra; Holtby, Richard; Gallay, Stephen; Henry, Patrick; Macritchie, Iona; Borthwick, Cheryl; Mayer, Lauren; Roknic, Carolyn; Shore, Deborah; Kamino, Allison; Grossman, Julie; Hill, Joanne; Singh, Gargi; Travers, Niki; Yanofsky, Loraine; Wilson, Marni; Sumar, Shellina; Savona, Alicia; De Medeiros, Filomena; Mann, Helen; Champsi, Aisha; Chau, Stefanie; Medeiros, Danielle; Richards, Robin R

2017-05-01

Work-related rotator cuff injuries are a common cause of disability and employee time loss. To examine the effectiveness of expedited rotator cuff surgery in injured workers who underwent rotator cuff decompression or repair and to explore the impact of demographic, clinical, and psychosocial factors in predicting the outcome of surgery. Case series; Level of evidence, 4. Injured workers who were seen at a shoulder specialty program and who underwent expedited arthroscopic rotator cuff decompression or repair were observed for a period of 6 to 12 months based on their type of surgery and recovery trajectory. The primary outcome measure was the American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment Form. The impact of surgery was assessed by whether the change in the ASES score exceeded the minimal clinically important difference (MCID) of 17 points. Secondary outcomes were range of motion (ROM), medication consumption, and work status. One hundred forty-six patients (43 women [29%], 103 men [71%]; mean age, 52 years; SD, 8 years) completed the study. Sixty-seven (46%) patients underwent rotator cuff repair. The mean time between the date the patient consented to have surgery and the date of surgery was 82 (SD, 44) days. There was a statistically significant improvement in ASES score and ROM and work status (52 returned to regular duties and 59 to modified duties) ( P satisfaction with the job. Expedited rotator cuff surgery improved disability, ROM, and work status in injured workers. Successful recovery after work-related shoulder injuries may further be facilitated by improving the psychosocial work environment and increasing access to care.

Development of a fast response rotating polarimeter for a faraday rotation measurement

International Nuclear Information System (INIS)

Maeno, Masaki; Ogiwara, Norio; Ogawa, Hiroaki; Matsuda, Toshiaki

1994-03-01

This paper describes a method for using a spindle sustained with active magnetic bearing to make a rotating half waveplate frequency more fast. The time interval of the zero-cross phase measurement is 189 μsec in this experiment. The magnetic bearing is applicable to increase the rotating waveplate frequency by a factor of 2-3 compared with the conventional one. The waveplate speed as well as the deviation with respect to the stationary laser beam has no influence on the amplitude and phase shift of the rotating polarized beam signal. There is also no influence of the mirror reflections on the phase shift. The overall phase resolution is estimated to be about 0.1 degrees. (author)

Narayanaswamy’s 1971 aging theory and material time

International Nuclear Information System (INIS)

Dyre, Jeppe C.

2015-01-01

The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy’s phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the “unique-triangles property” according to which any three points on the system’s path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)

Faraday's Rotating Wire--The Homopolar Motor: Time to Update?

Science.gov (United States)

Auty, Geoff

2010-01-01

Answering some of the questions raised in the production of a previous article led to the development of a simple alternative design for the rotating wire demonstration. Significantly, this demonstration avoids the use of mercury as a conducting liquid. The attempt to explain variations in performance of another model and seeking the best…

Acromion Index in Korean Population and Its Relationship with Rotator Cuff Tears.

Science.gov (United States)

Kum, Dong Ho; Kim, Jun Ho; Park, Keun Min; Lee, Eun Su; Park, Yong Bok; Yoo, Jae Chul

2017-06-01

Among the many causes of rotator cuff tears, scapular morphology is associated with the accelerating degenerative process of the rotator cuff. Acromion index (AI) was previously introduced and compared in two populations. We enrolled 100 Korean patients diagnosed with full-thickness rotator cuff tears by magnetic resonance imaging and intraoperative arthroscopic findings between January and December 2013. Another 100 Korean patients with an intact rotator cuff tendon identified on magnetic resonance imaging and other shoulder diseases, such as frozen shoulder and instability, were enrolled as controls. We retrospectively compared these 100 rotator cuff tear patients (mean age, 63 years) and 100 controls (mean age, 51 years) in this study. Two independent orthopedic surgeons assessed the AI on radiographs. We performed an interobserver reliability test of the AI assessment, and then compared the AI between two groups. The measurement of the AI showed excellent reliability (intraclass correlation coefficient, 0.82). The mean AI in the rotator cuff tear group was 0.68 and it was significantly different between groups ( p rotator cuff tears in a Korean population.

Microstructure evolution of 7050 Al alloy during age-forming

International Nuclear Information System (INIS)

Chen, Junfeng; Zou, Linchi; Li, Qiang; Chen, Yulong

2015-01-01

The microstructure evolution of the 7050 Al alloy treated by age-forming was studied using a designed device which can simulate the age-forming process. The grain shape, grain boundary misorientation and grain orientation evolution of 7050 Al alloy during age-forming have been quantitatively characterized by electron backscattering diffraction technique. The results show that age-forming produced abundant low-angle boundaries and elongated grains, which attributed to stress induced dislocation movement and grain boundary migration during the age-forming process. On the other side, the stress along rolling direction caused some unstable orientation grains to rotate towards the Brass and S orientations during the age-forming process. Hence, the intensity of the rolling texture orientation in age-formed samples is enhanced. But this effect decays gradually with increasing aging time, since stress decreases and precipitation hardening occurs during the age-forming process. - Highlights: • Quantitative analysis of grain evolution of 7050 Al alloys during age-forming • Stress induces some grain rotation of 7050 Al alloys during age-forming. • Creep leads to elongate grain of 7050 Al alloys during age-forming. • Obtains a trend on texture evolution during age-forming applied stress

Using service-time profiles for distributed planning of container barge rotations along terminals

NARCIS (Netherlands)

Douma, A.M.; Schuur, Peter; Schutten, Johannes M.J.

2008-01-01

We consider the barge rotation planning and quay scheduling problem in the Port of Rotterdam. This problem concerns the alignment of barge rotations and terminal quay schedules. We use a Multi-Agent based approach for the problem, since such a Multi-Agent based system can mirror to a large extent

Semiclassical approach to giant resonances of rotating nuclei

International Nuclear Information System (INIS)

Winter, J.

1983-01-01

Quadrupole and isovector dipole resonances of rotating nuclei are investigated in the frame-work of Vlasov equations transformed to a rotating system of reference, which are based on the time-dependent Hartree-method for schematic forces. The parameter free model of the self-consistent vibrating harmonic oscillator potential for the quadrupole mode is extended to a coupling to rotation, which also includes large-amplitude behaviour. A generalization to an exactly solvable two-liquid model describing the isovector mode is established; for rotating nuclei Hilton's explicit result for the eigenfrequencies is obtained. The advantage of using the concept of the classical kinetic momentum in a rotating system also in quantum-mechanical descriptions is demonstrated. It completes the standard transformation of density matrices by a time-odd part realized in a phase-factor and permits a more direct interpretation of rotation effects in terms of the classical forces of inertia. (author)

Time variable cosmological constants from the age of universe

International Nuclear Information System (INIS)

Xu Lixin; Lu Jianbo; Li Wenbo

2010-01-01

In this Letter, time variable cosmological constant, dubbed age cosmological constant, is investigated motivated by the fact: any cosmological length scale and time scale can introduce a cosmological constant or vacuum energy density into Einstein's theory. The age cosmological constant takes the form ρ Λ =3c 2 M P 2 /t Λ 2 , where t Λ is the age or conformal age of our universe. The effective equation of state (EoS) of age cosmological constant are w Λ eff =-1+2/3 (√(Ω Λ ))/c and w Λ eff =-1+2/3 (√(Ω Λ ))/c (1+z) when the age and conformal age of universe are taken as the role of cosmological time scales respectively. The EoS are the same as the so-called agegraphic dark energy models. However, the evolution histories are different from the agegraphic ones for their different evolution equations.

Effect of ageing time and temperature on the strain ageing behaviour of quenched zircaloy-4

International Nuclear Information System (INIS)

Rheem, K.S.; Park, W.K.; Yook, C.C.

1977-01-01

The strain ageing behaviour of quenched Zircaloy-4 has been studied as a function of ageing time and temperature in the temperature range 523-588 K for a short-ageing time of 1 to 52 seconds. A the test conditions, the strain ageing stress increased with ageing time and temperature at a strain rate of 5.55x10 -4 sec -1 . Applying stress on the quenched Zircaloy-4, the strain ageing effect indicated following two states: an initial stage having an activation energy of 0.39ev considered to be due to Snoek type ordering of interstitial oxygen atoms in the stress field of a dislocaiton and a second stage havingan activation energy of 0.60 ev, due to mainly long range diffusion of oxygen atoms. (author)

Normal isometric strength of rotator cuff muscles in adults

OpenAIRE

Chezar, A.; Berkovitch, Y.; Haddad, M.; Keren, Y.; Soudry, M.; Rosenberg, N.

2013-01-01

Objectives The most prevalent disorders of the shoulder are related to the muscles of rotator cuff. In order to develop a mechanical method for the evaluation of the rotator cuff muscles, we created a database of isometric force generation by the rotator cuff muscles in normal adult population. We hypothesised the existence of variations according to age, gender and dominancy of limb. Methods A total of 400 healthy adult volunteers were tested, classified into groups of 50 men and women for e...

Competitive swimmers with hypermobility have strength and fatigue deficits in shoulder medial rotation

DEFF Research Database (Denmark)

Liaghat, Behnam; Juul-Kristensen, Birgit; Frydendal, Thomas

2018-01-01

rotation (60°/s). Swimmers with GJHS showed significantly larger isokinetic fatigue at 180°/s (0.321 J/repetition; p = .010), and tendencies to lower levels of muscle activity in infraspinatus (20%, p = .066) and pectoralis major (34%, p = .092) at 60°/s during medial rotation. Young competitive swimmers...... rotations. Totally, 38 competitive swimmers (aged 13-17 years) participated, 19 were competitive swimmers with GJHS and 19 were age, sex and club matched swimmers without GJHS. Concentric isokinetic force in medial and lateral rotations were measured at 60°/s (5 repetitions) and 180°/s (10 repetitions...

Rotating Arc Jet Test Model: Time-Accurate Trajectory Heat Flux Replication in a Ground Test Environment

Science.gov (United States)

Laub, Bernard; Grinstead, Jay; Dyakonov, Artem; Venkatapathy, Ethiraj

2011-01-01

Though arc jet testing has been the proven method employed for development testing and certification of TPS and TPS instrumentation, the operational aspects of arc jets limit testing to selected, but constant, conditions. Flight, on the other hand, produces timevarying entry conditions in which the heat flux increases, peaks, and recedes as a vehicle descends through an atmosphere. As a result, we are unable to "test as we fly." Attempts to replicate the time-dependent aerothermal environment of atmospheric entry by varying the arc jet facility operating conditions during a test have proven to be difficult, expensive, and only partially successful. A promising alternative is to rotate the test model exposed to a constant-condition arc jet flow to yield a time-varying test condition at a point on a test article (Fig. 1). The model shape and rotation rate can be engineered so that the heat flux at a point on the model replicates the predicted profile for a particular point on a flight vehicle. This simple concept will enable, for example, calibration of the TPS sensors on the Mars Science Laboratory (MSL) aeroshell for anticipated flight environments.

The rotation of Titan and Ganymede

Science.gov (United States)

Van Hoolst, Tim; Coyette, Alexis; Baland, Rose-Marie; Trinh, Antony

2016-10-01

The rotation rates of Titan and Ganymede, the largest satellites of Saturn and Jupiter, are on average equal to their orbital mean motion. Here we discuss small deviations from the average rotation for both satellites and evaluate the polar motion of Titan induced by its surface fluid layers. We examine different causes at various time scales and assess possible consequences and the potential of using librations and polar motion as probes of the interior structure of the satellites.The rotation rate of Titan and Ganymede cannot be constant on the orbital time scale as a result of the gravitational torque of the central planet acting on the satellites. Titan is moreover expected to show significant polar motion and additional variations in the rotation rate due to angular momentum exchange with the atmosphere, mainly at seasonal periods. Observational evidence for deviations from the synchronous state has been reported several times for Titan but is unfortunately inconclusive. The measurements of the rotation variations are based on determinations of the shift in position of Cassini radar images taken during different flybys. The ESA JUICE (JUpiter ICy moons Explorer) mission will measure the rotation variations of Ganymede during its orbital phase around the satellite starting in 2032.We report on different theoretical aspects of the librations and polar motion. We consider the influence of the rheology of the ice shell and take into account Cassini measurements of the external gravitational field and of the topography of Titan and similar Galileo data about Ganymede. We also evaluate the librations and polar motion induced by Titan's hydrocarbon seas and use the most recent results of Titan's atmosphere dynamics. We finally evaluate the potential of rotation variations to constrain the satellite's interior structure, in particular its ice shell and ocean.

Hybrid state‐space time integration in a rotating frame of reference

DEFF Research Database (Denmark)

Krenk, Steen; Nielsen, Martin Bjerre

2011-01-01

displacements and the global velocities are represented by the same shape functions. This leads to a simple generalization of the corresponding equations of motion in a stationary frame in which all inertial effects are represented via the classic global mass matrix. The formulation introduces two gyroscopic......A time integration algorithm is developed for the equations of motion of a flexible body in a rotating frame of reference. The equations are formulated in a hybrid state‐space, formed by the local displacement components and the global velocity components. In the spatial discretization the local...... terms, while the centrifugal forces are represented implicitly via the hybrid state‐space format. An angular momentum and energy conserving algorithm is developed, in which the angular velocity of the frame is represented by its mean value. A consistent algorithmic damping scheme is identified...

Socio-ecological implications of modifying rotation lengths in forestry.

Science.gov (United States)

Roberge, Jean-Michel; Laudon, Hjalmar; Björkman, Christer; Ranius, Thomas; Sandström, Camilla; Felton, Adam; Sténs, Anna; Nordin, Annika; Granström, Anders; Widemo, Fredrik; Bergh, Johan; Sonesson, Johan; Stenlid, Jan; Lundmark, Tomas

2016-02-01

The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today's major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.

A Note on Classification of Spatially Homogeneous Rotating Space-Times According to Their Teleparallel Killing Vector Fields in Teleparallel Theory of Gravitation

International Nuclear Information System (INIS)

Shabbir, Ghulam; Khan, Suhail; Ali, Amjad

2011-01-01

In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique. It turns out that the dimension of the teleparallel Killing vector fields is 5 or 10. In the case of 10 teleparallel Killing vector fields the space-time becomes Minkowski and all the torsion components are zero. Teleparallel Killing vector fields in this case are exactly the same as in general relativity. In the cases of 5 teleparallel Killing vector fields we get two more conservation laws in the teleparallel theory of gravitation. Here we also discuss some well-known examples of spatially homogeneous rotating space-times according to their teleparallel Killing vector fields. (general)

Rotator cuff tears in children and adolescents: experience at a large pediatric hospital

International Nuclear Information System (INIS)

Zbojniewicz, Andrew M.; Emery, Kathleen H.; Maeder, Matthew E.; Salisbury, Shelia R.

2014-01-01

Prior literature, limited to small case series and case reports, suggests that rotator cuff tears are rare in adolescents. However, we have identified rotator cuff tears in numerous children and adolescents who have undergone shoulder MRI evaluation. The purpose of this study is to describe the prevalence and characteristics of rotator cuff tears in children and adolescents referred for MRI evaluation of the shoulder at a large pediatric hospital and to correlate the presence of rotator cuff tears with concurrent labral pathology, skeletal maturity and patient activity and outcomes. We reviewed reports from 455 consecutive non-contrast MRI and magnetic resonance arthrogram examinations of the shoulder performed during a 2-year period, and following exclusions we yielded 205 examinations in 201 patients (ages 8-18 years; 75 girls, 126 boys). Rotator cuff tears were classified by tendon involved, tear thickness (partial or full), surface and location of tear (when partial) and presence of delamination. We recorded concurrent labral pathology when present. Physeal patency of the proximal humerus was considered open, closing or closed. Statistical analysis was performed to evaluate for a relationship between rotator cuff tears and degree of physeal patency. We obtained patient activity at the time of injury, surgical reports and outcomes from clinical records when available. Twenty-five (12.2%) rotator cuff tears were identified in 17 boys and 7 girls (ages 10-18 years; one patient had bilateral tears). The supraspinatus tendon was most frequently involved (56%). There were 2 full-thickness and 23 partial-thickness tears with articular-side partial-thickness tears most frequent (78%). Insertional partial-thickness tears were more common (78%) than critical zone tears (22%) and 10 (43%) partial-thickness tears were delamination tears. Nine (36%) patients with rotator cuff tears had concurrent labral pathology. There was no statistically significant relationship between

Rotator cuff tears in children and adolescents: experience at a large pediatric hospital

Energy Technology Data Exchange (ETDEWEB)

Zbojniewicz, Andrew M.; Emery, Kathleen H. [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Maeder, Matthew E. [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Lenox Hill Hospital, Department of Radiology, New York, NY (United States); Salisbury, Shelia R. [University of Cincinnati College of Medicine, Division of Biostatistics and Epidemiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States)

2014-06-15

Prior literature, limited to small case series and case reports, suggests that rotator cuff tears are rare in adolescents. However, we have identified rotator cuff tears in numerous children and adolescents who have undergone shoulder MRI evaluation. The purpose of this study is to describe the prevalence and characteristics of rotator cuff tears in children and adolescents referred for MRI evaluation of the shoulder at a large pediatric hospital and to correlate the presence of rotator cuff tears with concurrent labral pathology, skeletal maturity and patient activity and outcomes. We reviewed reports from 455 consecutive non-contrast MRI and magnetic resonance arthrogram examinations of the shoulder performed during a 2-year period, and following exclusions we yielded 205 examinations in 201 patients (ages 8-18 years; 75 girls, 126 boys). Rotator cuff tears were classified by tendon involved, tear thickness (partial or full), surface and location of tear (when partial) and presence of delamination. We recorded concurrent labral pathology when present. Physeal patency of the proximal humerus was considered open, closing or closed. Statistical analysis was performed to evaluate for a relationship between rotator cuff tears and degree of physeal patency. We obtained patient activity at the time of injury, surgical reports and outcomes from clinical records when available. Twenty-five (12.2%) rotator cuff tears were identified in 17 boys and 7 girls (ages 10-18 years; one patient had bilateral tears). The supraspinatus tendon was most frequently involved (56%). There were 2 full-thickness and 23 partial-thickness tears with articular-side partial-thickness tears most frequent (78%). Insertional partial-thickness tears were more common (78%) than critical zone tears (22%) and 10 (43%) partial-thickness tears were delamination tears. Nine (36%) patients with rotator cuff tears had concurrent labral pathology. There was no statistically significant relationship between

Titrating decision processes in the mental rotation task.

Science.gov (United States)

Provost, Alexander; Heathcote, Andrew

2015-10-01

Shepard and Metzler's (1971) seminal mental-rotation task-which requires participants to decide if 1 object is a rotated version of another or its mirror image-has played a central role in the study of spatial cognition. We provide the first quantitative model of behavior in this task that is comprehensive in the sense of simultaneously providing an account of both error rates and the full distribution of response times. We used Brown and Heathcote's (2008) model of choice processing to separate out the contributions of mental rotation and decision stages. This model-based titration process was applied to data from a paradigm where converging evidence supported performance being based on rotation rather than other strategies. Stimuli were similar to Shepard and Metzler's block figures except a long major axis made rotation angle well defined for mirror stimuli, enabling comprehensive modeling of both mirror and normal responses. Results supported a mental rotation stage based on Larsen's (2014) model, where rotation takes a variable amount of time with a mean and variance that increase linearly with rotation angle. Differences in response threshold differences were largely responsible for mirror responses being slowed, and for errors increasing with rotation angle for some participants. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Narayanaswamy’s 1971 aging theory and material time

DEFF Research Database (Denmark)

Dyre, Jeppe C.

2015-01-01

The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy’s phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging...... description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time...

Rotational studies of late-type stars. II. Ages of solar-type stars and the rotational history of the sun

International Nuclear Information System (INIS)

Soderblom, D.R.

1983-01-01

In the first part of this investigation, age indicators for solar-type stars are discussed. A Li abundance-age calibration is derived; it indicates that 1 M/sub sun/ stars have lost as much as 80% of their initial Li before reaching the main sequence. The e-folding time for Li depletion on the main sequence is 1 1/4 Gyr. The distribution of Li abundances for 1 M/sub sun/ stars is consistent with a uniform initial Li abundance for all stars

Coherent spin-rotational dynamics of oxygen superrotors

Science.gov (United States)

Milner, Alexander A.; Korobenko, Aleksey; Milner, Valery

2014-09-01

We use state- and time-resolved coherent Raman spectroscopy to study the rotational dynamics of oxygen molecules in ultra-high rotational states. While it is possible to reach rotational quantum numbers up to N≈ 50 by increasing the gas temperature to 1500 K, low population levels and gas densities result in correspondingly weak optical response. By spinning {{O}2} molecules with an optical centrifuge, we efficiently excite extreme rotational states with N≤slant 109 in high-density room temperature ensembles. Fast molecular rotation results in the enhanced robustness of the created rotational wave packets against collisions, enabling us to observe the effects of weak spin-rotation coupling in the coherent rotational dynamics of oxygen. The decay rate of spin-rotational coherence due to collisions is measured as a function of the molecular angular momentum and its dependence on the collisional adiabaticity parameter is discussed. We find that at high values of N, the rotational decoherence of oxygen is much faster than that of the previously studied non-magnetic nitrogen molecules, pointing at the effects of spin relaxation in paramagnetic gases.

Rotation commensurate echo of asymmetric molecules—Molecular fingerprints in the time domain

Energy Technology Data Exchange (ETDEWEB)

Chesnokov, E. N., E-mail: chesnok@kinetics.nsc.ru [Institute of Chemical Kinetics and Combustion, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Kubarev, V. V. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Koshlyakov, P. V. [Institute of Chemical Kinetics and Combustion, Novosibirsk 630090 (Russian Federation)

2014-12-29

Using the pulses of terahertz free electron laser and ultra-fast Schottky diode detectors, we observed the coherent transients within a free induction decay of gaseous nitrogen dioxide NO{sub 2}. The laser excited different sub-bands of rotation spectra of NO{sub 2} containing about 50–70 lines. The free induction signal continued more than 30 ns and consisted of many echo-like bursts duration about 0.2 ns. Unlike the similar effect observed previously for linear and symmetric top molecules, the sequence of echo bursts is not periodic. The values for delay of individual echo are stable, and the set of these delays can be considered as a “molecular fingerprint” in the time domain.

Reducing Postoperative Pterygium Recurrence: Comparison of Free Conjunctival Auto-Graft and Conjunctival Rotation Flap Techniques

International Nuclear Information System (INIS)

Akhter, W.; Tayyab, A.; Kausar, A.; Masrur, A.

2014-01-01

Objective: To compare the recurrence of pterygium between free conjunctival auto-graft and conjunctival rotation flap following simple surgical excision of pterygium. Study Design: Quasi-experimental study. Place and Duration of Study: Shifa Foundation Community Health Clinic, Shifa College of Medicine, Islamabad, from January to November 2012. Methodology: Fifty seven cases aged above 18 years, with a pterygium corneal encroachment of 2 mm which was responsible for visual disability or was cosmetically undesirable were recruited for the study and randomly assigned to conjunctival auto-graft group and conjunctival rotation flap group. Cases with a history of glaucoma or glaucoma suspect, prior pterygium surgery, pterygium with concurrent ocular surface and lid disease, conjunctival inflammation and scarring, pseudo-pterygium or collagen vascular disease were excluded. After simple pterygium excision conjunctival auto-graft group (n=26) cases received a free conjunctival flap was transplanted, while conjunctival rotation flap group (n=31) cases received a conjunctival rotation flap. All cases were followed-up for 6 months after surgery for recurrence and complications. Frequency distribution and significance of association of recurrence using Fisher's exact test and Mann- Whitney U-test was carried out using Statistical Package for Social Sciences (SPSS) version 20. Results: The median (and inter-quartile range) age and surgery duration in conjunctival auto-graft group and conjunctival rotation flap group were 60 (51.50 - 63.00) and 57 (45.00 - 60.00) years, 28.50 (27.00 - 30.50) and 16.00 (15.00 - 17.00) minutes respectively. Recurrence was seen in 2 (7.96%) and 3 (9.76%) cases in auto-graft and rotation flap groups respectively. No significant difference was seen in postoperative complications between the two groups (p=0.60). Conclusion: The surgical time for conjunctival rotation flap procedure is less as compared to free auto-graft, while their recurrence and

INFORMATIONAL MODEL OF MENTAL ROTATION OF FIGURES

Directory of Open Access Journals (Sweden)

V. A. Lyakhovetskiy

2016-01-01

Full Text Available Subject of Study.The subject of research is the information structure of objects internal representations and operations over them, used by man to solve the problem of mental rotation of figures. To analyze this informational structure we considered not only classical dependencies of the correct answers on the angle of rotation, but also the other dependencies obtained recently in cognitive psychology. Method.The language of technical computing Matlab R2010b was used for developing information model of the mental rotation of figures. Such model parameters as the number of bits in the internal representation, an error probability in a single bit, discrete rotation angle, comparison threshold, and the degree of difference during rotation can be changed. Main Results.The model reproduces qualitatively such psychological dependencies as the linear increase of time of correct answers and the number of errors on the angle of rotation for identical figures, "flat" dependence of the time of correct answers and the number of errors on the angle of rotation for mirror-like figures. The simulation results suggest that mental rotation is an iterative process of finding a match between the two figures, each step of which can lead to a significant distortion of the internal representation of the stored objects. Matching is carried out within the internal representations that have no high invariance to rotation angle. Practical Significance.The results may be useful for understanding the role of learning (including the learning with a teacher in the development of effective information representation and operations on them in artificial intelligence systems.

Wave-driven Rotation in Supersonically Rotating Mirrors

Energy Technology Data Exchange (ETDEWEB)

A. Fetterman and N.J. Fisch

2010-02-15

Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

Wave-driven Rotation in Supersonically Rotating Mirrors

International Nuclear Information System (INIS)

Fetterman, A.; Fisch, N.J.

2010-01-01

Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

Rotator manşetin kalsifiye tendinitinin artroskopik tedavisi

OpenAIRE

Ozkoc, Gurkan; Akpinar, Sercan; Hersekli, Murat; Ozalay, Metin; Tandogan, Reha

2004-01-01

Objectives: We evaluated the effectiveness of arthroscopic treatment in patients with rotator cuff calcifying tendinitis unresponsive to conservative treatment.Methods: Arthroscopic treatment was performed in 10 patients (6 females, 4 males; mean age 46 years; range 34 to 53 years) in whom pain and functional disability persisted for more than a year despite conservative therapy for rotator cuff calcifying tendinitis. Arthroscopic bursectomy was also carried out. One patient underwent repair ...

Design of a high speed rotating mechanical shutter

International Nuclear Information System (INIS)

Stowers, I.F.; Merritt, B.T.; McFann, C.B.

1979-01-01

A high-speed rotating shutter was designed to operate in a 10 -6 Torr vacuum at the optical focus of a laser spatial filter. The shutter is basically a wheel, with a single 3 x 10-mm slot at the perimeter, which rotates with a peripheral speed of 1 km/s. The motor to drive the rotating wheel is magnetically suspended and synchronously wound. The wheel achieves a 4 μs opening time and a timing accuracy of better than 0.2 μs

Three-dimensional real-time synthetic aperture imaging using a rotating phased array transducer

DEFF Research Database (Denmark)

Nikolov, Svetoslav; Dufait, Remi; Schoisswohl, Armin

2002-01-01

phased array, which is rotated over the volume of interest. The data is acquired using coded signals and synthetic transmit aperture imaging. Only one group of elements transmits at a time. The delays are set such as to form a cylindrical wave. The back-scattered signal carries information not only from......Current 3D real-time imaging is done either with sparse 2D arrays, or with mechanically moved phased arrays. The former results in a poor resolution and contrast due to a limited amount of elements. The latter has the disadvantage of low frame rates due to the sequential acquisition of the volume...... line-by-line and plane-by-plane. This paper describes an approach which combines mechanically moved phased array with synthetic transmit aperture imaging, resulting in high volume acquisition rates without a trade-off in image quality. The scan method uses a conventional fully populated 64 element...

ECONOMIC ROTATION OF Eucalyptus grandis PLANTATIONS FOR PULP PRODUCTION

Directory of Open Access Journals (Sweden)

Thais Cunha Ferreira

2004-07-01

Full Text Available The objectives of the research were: to determine the economic impact of several minimum diameter and length of logs in economic rotation age, economic feasibility of Eucalyptus grandis plantation for cellulose production; to determine the economic loss of cutting the stand before or after the optimal economic rotation age. A biometric model for making wood volume prognosis was developed using data of a trial of Eucalyptus grandis plantation envisaging pulp production. Eucalyptus grandis stands of 19 and 103 months old, in the spacing 3 x 2 and 3 x 3 m in site index of 30; 28; 26 and 24 m were used. Theprognosis started at the age zero, considering logs of 2.5; 2.8; 4.0 and 6.0 m of length for minimum diameter varying from 4 to 10 cm, in intervals of 2 cm. Net Present Worth (VPL was used the economic criterion, considering an infinite horizon and a cost relation including reestablishment, yearly maintenance, logging and wood transportation costs. The main conclusions were: increases in the minimum diameter and or in logs length increase the rotation age; harvesting the stands in ages different from the optimal one cause large economic loss mainly in the better sites; the economic loss is larger if the harvest is made before the optimal economic rotation than if it is make after; economic feasibility increases when the minimum diameter is smaller and when the length of the logs is shorter. Any way, before making any decision it is necessary to take into account possible technical restrictions and effect on harvest and transportation costs caused by changer in the length of logs and in the size of the minimum commercial diameter.

Rotating flow

CERN Document Server

Childs, Peter R N

2010-01-01

Rotating flow is critically important across a wide range of scientific, engineering and product applications, providing design and modeling capability for diverse products such as jet engines, pumps and vacuum cleaners, as well as geophysical flows. Developed over the course of 20 years' research into rotating fluids and associated heat transfer at the University of Sussex Thermo-Fluid Mechanics Research Centre (TFMRC), Rotating Flow is an indispensable reference and resource for all those working within the gas turbine and rotating machinery industries. Traditional fluid and flow dynamics titles offer the essential background but generally include very sparse coverage of rotating flows-which is where this book comes in. Beginning with an accessible introduction to rotating flow, recognized expert Peter Childs takes you through fundamental equations, vorticity and vortices, rotating disc flow, flow around rotating cylinders and flow in rotating cavities, with an introduction to atmospheric and oceanic circul...

Rotational seismology

Science.gov (United States)

Lee, William H K.

2016-01-01

Rotational seismology is an emerging study of all aspects of rotational motions induced by earthquakes, explosions, and ambient vibrations. It is of interest to several disciplines, including seismology, earthquake engineering, geodesy, and earth-based detection of Einstein’s gravitation waves.Rotational effects of seismic waves, together with rotations caused by soil–structure interaction, have been observed for centuries (e.g., rotated chimneys, monuments, and tombstones). Figure 1a shows the rotated monument to George Inglis observed after the 1897 Great Shillong earthquake. This monument had the form of an obelisk rising over 19 metres high from a 4 metre base. During the earthquake, the top part broke off and the remnant of some 6 metres rotated about 15° relative to the base. The study of rotational seismology began only recently when sensitive rotational sensors became available due to advances in aeronautical and astronomical instrumentations.

Statistical model of exotic rotational correlations in emergent space-time

Energy Technology Data Exchange (ETDEWEB)

Hogan, Craig; Kwon, Ohkyung; Richardson, Jonathan

2017-06-06

A statistical model is formulated to compute exotic rotational correlations that arise as inertial frames and causal structure emerge on large scales from entangled Planck scale quantum systems. Noncommutative quantum dynamics are represented by random transverse displacements that respect causal symmetry. Entanglement is represented by covariance of these displacements in Planck scale intervals defined by future null cones of events on an observer's world line. Light that propagates in a nonradial direction inherits a projected component of the exotic rotational correlation that accumulates as a random walk in phase. A calculation of the projection and accumulation leads to exact predictions for statistical properties of exotic Planck scale correlations in an interferometer of any configuration. The cross-covariance for two nearly co-located interferometers is shown to depart only slightly from the autocovariance. Specific examples are computed for configurations that approximate realistic experiments, and show that the model can be rigorously tested.

The Effect of Shoulder Plyometric Training on Amortization Time and Upper-Extremity Kinematics.

Science.gov (United States)

Swanik, Kathleen A; Thomas, Stephen J; Struminger, Aaron H; Bliven, Kellie C Huxel; Kelly, John D; Swanik, Charles B

2016-12-01

Plyometric training is credited with providing benefits in performance and dynamic restraint. However, limited prospective data exist quantifying kinematic adaptations such as amortization time, glenohumeral rotation, and scapulothoracic position, which may underlie the efficacy of plyometric training for upper-extremity rehabilitation or performance enhancement. To measure upper-extremity kinematics and plyometric phase times before and after an 8-wk upper-extremity strength- and plyometric-training program. Randomized pretest-posttest design. Research laboratory. 40 recreationally active men (plyometric group, age 20.43 ± 1.40 y, height 180.00 ± 8.80 cm, weight 73.07 ± 7.21 kg; strength group, age 21.95 ± 3.40 y, height 173.98 ± 11.91 cm, weight 74.79 ± 13.55 kg). Participants were randomly assigned to either a strength-training group or a strength- and plyometric-training group. Each participant performed the assigned training for 8 wk. Dynamic and static glenohumeral and scapular-rotation measurements were taken before and after the training programs. Dynamic measurement of scapular rotation and time spent in each plyometric phase (concentric, eccentric, and amortization) during a ball-toss exercise were recorded while the subjects were fitted with an electromagnetic tracking system. Static measures included scapular upward rotation at 3 different glenohumeral-abduction angles, glenohumeral internal rotation, and glenohumeral external rotation. Posttesting showed that both groups significantly decreased the time spent in the amortization, concentric, and eccentric phases of a ball-toss exercise (P plyometric-training group exhibited an increase in internal rotation that was not present in the strength-training group (P plyometrics and strength training for reducing commonly identified upper-extremity-injury risk factors and improving upper-extremity performance.

The effect of expedited rotator cuff surgery in injured workers: a case-control study.

Science.gov (United States)

Razmjou, Helen; Lincoln, Sandra; Boljanovic, Dragana; Gallay, Stephen; Henry, Patrick; Richards, Robin R; Holtby, Richard

2017-07-01

Expediting rotator cuff surgery is expected to facilitate recovery and return to work in injured workers. This case-control study examined the effect of expedited rotator cuff surgery on recovery and work status in injured workers. Injured workers who had undergone an expedited rotator cuff surgery funded by parallel-pay insurance (study group) were compared with workers who had used the public health insurance (control group) while adjusting for sex, age, severity of pathology, and follow-up period. Disability was measured by the American Shoulder and Elbow Surgeons (ASES) Standardized Assessment Form score. The percentage of patients who exceeded the minimal clinically important difference of 17 points in the ASES was calculated. The study group waited less time to have surgery than the control group (P workers who underwent expedited rotator cuff surgery reported less disability and had a more successful return to work after surgery than injured workers who waited longer for specialist assessment and surgery within the public health system. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Growth-related problems of aging and senescence in fast growing trees grown on short rotations

Energy Technology Data Exchange (ETDEWEB)

Blake, T J

1981-06-01

The paper is aimed at identifying some possible problem areas in the future management of coppice stands on short rotations. The paper considers the possible role of plant hormones, water, cultural and enviromental factors in regulating shoot production, growth and senescence in hardwoods grown on short rotations for biomass production. 77 references.

Immobilization in External Rotation Versus Internal Rotation After Primary Anterior Shoulder Dislocation: A Meta-analysis of Randomized Controlled Trials.

Science.gov (United States)

Whelan, Daniel B; Kletke, Stephanie N; Schemitsch, Geoffrey; Chahal, Jaskarndip

2016-02-01

The recurrence rate after primary anterior shoulder dislocation is high, especially in young, active individuals. Recent studies have suggested external rotation immobilization as a method to reduce the rate of recurrent shoulder dislocation in comparison to traditional sling immobilization. To assess and summarize evidence from randomized controlled trials on the effect of internal rotation versus external rotation immobilization on the rate of recurrence after primary anterior shoulder dislocation. Meta-analysis. PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and abstracts from recent proceedings were searched for eligible studies. Two reviewers selected studies for inclusion, assessed methodological quality, and extracted data. Six randomized controlled trials (632 patients) were included in this review. Demographic and prognostic variables measured at baseline were similar in the pooled groups. The average age was 30.1 years in the pooled external rotation group and 30.3 years in the pooled internal rotation group. Two studies found that external rotation immobilization reduced the rate of recurrence after initial anterior shoulder dislocation compared with conventional internal rotation immobilization, whereas 4 studies failed to find a significant difference between the 2 groups. This meta-analysis suggested no overall significant difference in the rate of recurrence among patients treated with internal rotation versus external rotation immobilization (risk ratio, 0.69; 95% CI, 0.42-1.14; P = .15). There was no significant difference in the rate of compliance between internal and external rotation immobilization (P = .43). The Western Ontario Shoulder Instability Index scores were pooled across 3 studies, and there was no significant difference between the 2 groups (P = .54). Immobilization in external rotation is not significantly more effective in reducing the recurrence rate after primary anterior shoulder dislocation than

Time averaging, ageing and delay analysis of financial time series

Science.gov (United States)

Cherstvy, Andrey G.; Vinod, Deepak; Aghion, Erez; Chechkin, Aleksei V.; Metzler, Ralf

2017-06-01

We introduce three strategies for the analysis of financial time series based on time averaged observables. These comprise the time averaged mean squared displacement (MSD) as well as the ageing and delay time methods for varying fractions of the financial time series. We explore these concepts via statistical analysis of historic time series for several Dow Jones Industrial indices for the period from the 1960s to 2015. Remarkably, we discover a simple universal law for the delay time averaged MSD. The observed features of the financial time series dynamics agree well with our analytical results for the time averaged measurables for geometric Brownian motion, underlying the famed Black-Scholes-Merton model. The concepts we promote here are shown to be useful for financial data analysis and enable one to unveil new universal features of stock market dynamics.

Investigating stellar surface rotation using observations of starspots

DEFF Research Database (Denmark)

Korhonen, Heidi Helena

2011-01-01

Rapid rotation enhances the dynamo operating in stars, and thus also introduces significantly stronger magnetic activity than is seen in slower rotators. Many young cool stars still have the rapid, primordial rotation rates induced by the interstellar molecular cloud from which they were formed....... Also older stars in close binary systems are often rapid rotators. These types of stars can show strong magnetic activity and large starspots. In the case of large starspots which cause observable changes in the brightness of the star, and even in the shapes of the spectral line profiles, one can get...... information on the rotation of the star. At times even information on the spot rotation at different stellar latitudes can be obtained, similarly to the solar surface differential rotation measurements using magnetic features as tracers. Here, I will review investigations of stellar rotation based...

The effects of time, temperature and rotation of water on the corrosion rate of different types of steels

International Nuclear Information System (INIS)

Muhamad Daud; Jamaliah Shariff.

1984-01-01

By using hot plate/magnetic stirrer and immersion technique, the steel corroded uniformly and their corrosion rates vary due to type of steel, time of immersion, temperature and rotation of water. Therefore the rate of general corrosion, or sealing, of steel alloys is influenced by a number of factors, those best established being the composition of the metal, time, temperature, velocity, cleanliness or roughness of the metal surface and direct contact with solutions of the other materials. (author)

Differences of RNA Expression in the Tendon According to Anatomic Outcomes in Rotator Cuff Repair.

Science.gov (United States)

Ahn, Jin-Ok; Chung, Jin-Young; Kim, Do Hoon; Im, Wooseok; Kim, Sae Hoon

2017-11-01

Despite increased understanding of the pathophysiology of rotator cuff tears and the evolution of rotator cuff repair, healing failure remains a substantial problem. The critical roles played by biological factors have been emphasized, but little is known of the implications of gene expression profile differences at the time of repair. To document the relationship between the perioperative gene expression of healed and unhealed rotator cuffs by RNA microarray analysis. Case-control study; Level of evidence, 3. Superior (supraspinatus involvement) and posterosuperior (supraspinatus and infraspinatus involvement) tears were included in the study. Samples of rotator cuff tendons were prospectively collected during rotator cuff surgery. Three samples were harvested at the tendon ends of tears from the anterior, middle (apex), and posterior parts using an arthroscopic punch. Seven patients with an unhealed rotator cuff were matched one-to-one with patients with a healed rotator cuff by sex, age, tear size, and fatty degeneration of rotator cuff muscles. mRNA microarray analysis was used to identify genetic differences between healed and unhealed rotator cuff tendons. Gene ontology and gene association files were obtained from the Gene Ontology Consortium, and the Gene Ontology system in DAVID was used to identify enhanced biological processes. Microarray analyses identified 262 genes that were differentially expressed by at least 1.5-fold between the healed and unhealed groups. Overall, in the healed group, 103 genes were significantly downregulated, and 159 were significantly upregulated. DAVID Functional Annotation Cluster analysis showed that in the healed group, the genes most upregulated were related to the G protein-coupled receptor protein signaling pathway and to the neurological system. On the other hand, the genes most downregulated were related to immune and inflammatory responses. BMP5 was the gene most upregulated in the healed group, and the majority of

Gastrointestinal mean transit times in young and middle-aged healthy subjects

DEFF Research Database (Denmark)

Graff, J; Brinch, K; Madsen, Jan Lysgård

2001-01-01

To investigate the effects of age and gender on gastric, small intestinal and colonic mean transit times, a study was conducted in 32 healthy volunteers: eight young women (22-30 years), eight young men (20-28 years), eight middle-aged women (43-51 years) and eight middle-aged men (38-53 years......, small intestinal and colonic mean transit times were calculated. The gastric, small intestinal and colonic mean transit times were significantly longer in women. Ageing was shown to accelerate the gastric and small intestinal transit significantly. In the group of men the colonic mean transit time...... was unaffected by age, but middle-aged women had a significantly slower colonic transit than young women. We therefore conclude that both age and gender have to be considered when reference values for gastric, small intestinal and colonic mean transit times have to be established....

Does the Rotator Cuff Tear Pattern Influence Clinical Outcomes After Surgical Repair?

Science.gov (United States)

Watson, Scott; Allen, Benjamin; Robbins, Chris; Bedi, Asheesh; Gagnier, Joel J; Miller, Bruce

2018-03-01

Limited literature exists regarding the influence of rotator cuff tear morphology on patient outcomes. To determine the effect of rotator cuff tear pattern (crescent, U-shape, L-shape) on patient-reported outcomes after rotator cuff repair. Cohort study; Level of evidence, 3. Patients undergoing arthroscopic repair of known full-thickness rotator cuff tears were observed prospectively at regular intervals from baseline to 1 year. The tear pattern was classified at the time of surgery as crescent, U-shaped, or L-shaped. Primary outcome measures were the Western Ontario Rotator Cuff Index (WORC), the American Shoulder and Elbow Surgeons (ASES), and a visual analog scale (VAS) for pain. The tear pattern was evaluated as the primary predictor while controlling for variables known to affect rotator cuff outcomes. Mixed-methods regression and analysis of variance (ANOVA) were used to examine the effects of tear morphology on patient-reported outcomes after surgical repair from baseline to 1 year. A total of 82 patients were included in the study (53 male, 29 female; mean age, 58 years [range, 41-75 years]). A crescent shape was the most common tear pattern (54%), followed by U-shaped (25%) and L-shaped tears (21%). There were no significant differences in outcome scores between the 3 groups at baseline. All 3 groups showed statistically significant improvement from baseline to 1 year, but analysis failed to show any predictive effect in the change in outcome scores from baseline to 1 year for the WORC, ASES, or VAS when tear pattern was the primary predictor. Further ANOVA also failed to show any significant difference in the change in outcome scores from baseline to 1 year for the WORC ( P = .96), ASES ( P = .71), or VAS ( P = .86). Rotator cuff tear pattern is not a predictor of functional outcomes after arthroscopic rotator cuff repair.

Establishing a New Screening System for Mild Cognitive Impairment and Alzheimer's Disease with Mental Rotation Tasks that Evaluate Visuospatial Function.

Science.gov (United States)

Suzuki, Ayuko; Shinozaki, Jun; Yazawa, Shogo; Ueki, Yoshino; Matsukawa, Noriyuki; Shimohama, Shun; Nagamine, Takashi

2018-01-01

The mental rotation task is well-known for the assessment of visuospatial function; however, it has not been used for screening of dementia patients. The aim of this study was to create a simple screening test for patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) by focusing on non-amnestic symptoms. Age-matched healthy controls (age 75.3±6.8), patients with MCI (76.5±5.5), and AD (78.2±5.0) participated in this study. They carried out mental rotation tasks targeting geometric graphics or alphabetical characters with three rotating angles (0°, 90°, and 180°) and indicated the correct answer. Response accuracy and reaction time were recorded along with their eye movements using an eye tracker. To quantify their visual processing strategy, the run count ratio (RC ratio) was calculated by dividing the mean number of fixations in incorrect answers by that in correct answers. AD patients showed lower accuracy and longer reaction time than controls. They also showed a significantly greater number of fixation and smaller saccade amplitude than controls, while fixation duration did not differ significantly. The RC ratio was higher for AD, followed by MCI and control groups. By setting the cut-off value to 0.47 in the 180° rotating angle task, we could differentiate MCI patients from controls with a probability of 80.0%. We established a new screening system for dementia patients by evaluating visuospatial function. The RC ratio during a mental rotation task is useful for discriminating MCI patients from controls.

Shoulder rotator isokinetic strength profile in young swimmers

Directory of Open Access Journals (Sweden)

Nuno Miguel Prazeres Batalha

2012-08-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2012v14n5p545  Considering that some studies suggest that shoulder rotators muscle imbal­ances are related to joint pain and injury, and that there are no normative data for young swimmers, the aim of this study was: i to describe the muscle balance, fatigue and isokinetic strength profile of the shoulder rotators in young swimmers; ii to compare the results between swimmers and a group of young non-practitioners; iii to contribute to the acquisition of normative data of unilateral ratios of shoulder rotators. We evaluated the shoulder rotators concentric strength and unilateral ratios (ratio between torque of external and internal rotators of 60 swimmers (age: 14.55 ± 0.5 years old; body mass: 61.16 ± 7.08 kg and 60 non-practitioners (age: 14.62 ± 0.49 years old; body mass: 60.22 ± 10.01 kg. The evaluation was performed in the sitting position (90° abduction and elbow flexion at 60º.s-1 and 180º.s-1 angular speeds using an isokinetic dynamometer (Biodex System 3. The results of the fatigue ratios revealed no differences between the groups. Swimmers showed unilateral ratios of 73.39 ± 17.26% in the dominant limb (DL and 77.89 ± 15,23% in the non-dominant limb (NDL for assessments at 60º.s-1. At 180º.s-1, ratios were 74.77± 13.99% for DL and 70.11 ± 14.57% for NDL. Swimmers presented greater muscle imbalance, and differed from non-practitioners in the ability to produce power with the internal rotators, which was significantly higher in the former group.

Rotational and translational dynamics and their relation to hydrogen bond lifetimes in an ionic liquid by means of NMR relaxation time experiments and molecular dynamics simulation

Science.gov (United States)

Strate, Anne; Neumann, Jan; Overbeck, Viviane; Bonsa, Anne-Marie; Michalik, Dirk; Paschek, Dietmar; Ludwig, Ralf

2018-05-01

We report a concerted theoretical and experimental effort to determine the reorientational dynamics as well as hydrogen bond lifetimes for the doubly ionic hydrogen bond +OH⋯O- in the ionic liquid (2-hydroxyethyl)trimethylammonium bis(trifluoromethylsulfonyl)imide [Ch][NTf2] by using a combination of NMR relaxation time experiments, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations. Due to fast proton exchange, the determination of rotational correlation times is challenging. For molecular liquids, 17O-enhanced proton relaxation time experiments have been used to determine the rotational correlation times for the OH vectors in water or alcohols. As an alternative to those expensive isotopic substitution experiments, we employed a recently introduced approach which is providing access to the rotational dynamics from a single NMR deuteron quadrupolar relaxation time experiment. Here, the deuteron quadrupole coupling constants (DQCCs) are obtained from a relation between the DQCC and the δ1H proton chemical shifts determined from a set of DFT calculated clusters in combination with experimentally determined proton chemical shifts. The NMR-obtained rotational correlation times were compared to those obtained from MD simulations and then related to viscosities for testing the applicability of popular hydrodynamic models. In addition, hydrogen bond lifetimes were derived, using hydrogen bond population correlation functions computed from MD simulations. Here, two different time domains were observed: The short-time contributions to the hydrogen lifetimes and the reorientational correlation times have roughly the same size and are located in the picosecond range, whereas the long-time contributions decay with relaxation times in the nanosecond regime and are related to rather slow diffusion processes. The computed average hydrogen bond lifetime is dominated by the long-time process, highlighting the importance and longevity of

The two-week pediatric surgery rotation: is it time wasted?

Science.gov (United States)

Dutta, S; Wales, P W; Fecteau, A

2004-05-01

With increasing medical school emphasis on generalist training and decreasing enrollment in surgical residency, the authors assessed the adequacy of a 2-week pediatric surgery rotation on meeting the learning and competency objectives outlined in The Canadian Association of Pediatric Surgeons' Self-Directed Evaluation Tool. A prospective survey was conducted of 39 clinical clerks. An anonymous self-assessment scale measuring competency objectives (medical and psychosocial) was administered pre-and postrotation. Also, exposure to pediatric surgical conditions from a list of "essential" and "nonessential" learning objectives was measured. Statistical analysis was performed using paired t test with significance at.05 level. Response rate was 77% and 54% for the competency and learning objectives, respectively. Students reported improvement in medical (P awareness of the breadth of pediatric surgical practice (P <.0001; 95% CI 2.06, 3.18). A 2-week rotation in pediatric surgery appears adequate in fulfilling most competency and learning objectives, but discussion is needed about how to best assess student competency, which topics are considered essential, and the long-term effect on recruitment to the profession.

The various contributions in Venus rotation rate and LOD

Science.gov (United States)

Cottereau, L.; Rambaux, N.; Lebonnois, S.; Souchay, J.

2011-07-01

Context. Thanks to the Venus Express Mission, new data on the properties of Venus could be obtained, in particular concerning its rotation. Aims: In view of these upcoming results, the purpose of this paper is to determine and compare the major physical processes influencing the rotation of Venus and, more particularly, the angular rotation rate. Methods: Applying models already used for Earth, the effect of the triaxiality of a rigid Venus on its period of rotation are computed. Then the variations of Venus rotation caused by the elasticity, the atmosphere, and the core of the planet are evaluated. Results: Although the largest irregularities in the rotation rate of the Earth on short time scales are caused by its atmosphere and elastic deformations, we show that the irregularities for Venus are dominated by the tidal torque exerted by the Sun on its solid body. Indeed, as Venus has a slow rotation, these effects have a large amplitude of two minutes of time (mn). These variations in the rotation rate are greater than the one induced by atmospheric wind variations that can reach 25-50 s of time (s), depending on the simulation used. The variations due to the core effects that vary with its size between 3 and 20 s are smaller. Compared to these effects, the influence of the elastic deformation caused by the zonal tidal potential is negligible. Conclusions: As the variations in the rotation of Venus reported here are close to 3 mn peak to peak, they should influence past, present, and future observations, thereby providing further constraints on the planet's internal structure and atmosphere.

Study of insomnia in rotating shift-workers

Directory of Open Access Journals (Sweden)

Kaushik Chatterjee

2017-01-01

Full Text Available Background: Shift-workers commonly suffer from insomnia. This study evaluates different domains of insomnia. Aim: This study was aimed to study sleep and insomnia in rotating shift-workers and compare with day-workers. Materials and Methods: This was case–control study. The sleep of rotating shift-workers is compared with day workers using Athens Insomnia Scale. Results: Rotating shift-workers had significantly higher scores on Athens insomnia scale on domains of initial, intermediate and terminal insomnia than day workers. Duration and quality of sleep and sense of well-being are lower in rotating shift-workers. Rotating shift-workers also experienced more day-time sleepiness than day workers. However, there was no difference in perceived physical and mental functioning between the two groups. Conclusion: Individuals working in rotating shifts for more than 15 days have significantly higher prevalence of insomnia than day-workers.

The role of time and time perspective in age-related processes: Introduction to the special issue.

Science.gov (United States)

Fung, Helene H; Isaacowitz, Derek M

2016-09-01

There currently appears to be a general consensus on the relationship between time perspective and aging, such that (a) future time is perceived as more limited with age and (b) older people are more present-focused and less future-focused than younger people. At the same time, there are debates about whether these age differences are positively related to well-being and to what extent there are boundary conditions beyond which these age differences would cease to occur. The 8 manuscripts included in this Special Issue attempt to shed light on these debates. In doing so, they refine the dominant theoretical perspective on the topic-socioemotional selectivity theory-and introduce new theoretical perspectives. New measures and methodologies for studying time perspective and aging are also discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Hydromagnetic rotational braking of magnetic stars

International Nuclear Information System (INIS)

Fleck, R.C. Jr.

1980-01-01

It is suggested that the magnetic Ap stars can be rotationally decelerated to long periods by the braking action of the associated magnetic field on time scales of order 10 7 --10 10 years depending on whether the star's dipole field is aligned perpendicular or parallel to the rotation axis. Rotation includes a toroidal magnetic field in the plasma surrounding a star, and the accompanying magnetic stresses produce a net torque acting to despin the star. These results indicate that it is not necessary to postulate mass loss or mass accretion for this purely hydromagnetic braking effect

Comorbidities in rotator cuff disease: a case-control study.

Science.gov (United States)

Titchener, Andrew G; White, Jonathan J E; Hinchliffe, Sally R; Tambe, Amol A; Hubbard, Richard B; Clark, David I

2014-09-01

Rotator cuff disease is a common condition in the general population, but relatively little is known about its associated risk factors. We have undertaken a large case-control study using The Health Improvement Network database to assess and to quantify the relative contributions of some constitutional and environmental risk factors for rotator cuff disease in the community. Our data set included 5000 patients with rotator cuff disease who were individually matched with a single control by age, sex, and general practice (primary care practice). The median age at diagnosis was 55 years (interquartile range, 44-65 years). Multivariate analysis showed that the risk factors associated with rotator cuff disease were Achilles tendinitis (odds ratio [OR] = 1.78), trigger finger (OR = 1.99), lateral epicondylitis (OR = 1.71), and carpal tunnel syndrome (OR = 1.55). Oral corticosteroid therapy (OR = 2.03), oral antidiabetic use (OR = 1.66), insulin use (OR = 1.77), and "overweight" body mass index of 25.1 to 30 (OR = 1.15) were also significantly associated. Current or previous smoking history, body mass index of greater than 30, any alcohol intake, medial epicondylitis, de Quervain syndrome, cubital tunnel syndrome, and rheumatoid arthritis were not found to be associated with rotator cuff disease. We have identified a number of comorbidities and risk factors for rotator cuff disease. These include lateral epicondylitis, carpal tunnel syndrome, trigger finger, Achilles tendinitis, oral corticosteroid use, and diabetes mellitus. The findings should alert the clinician to comorbid pathologic processes and guide future research into the etiology of this condition. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

THE ROTATION PERIOD OF HD-77581 (VELA X-1)

NARCIS (Netherlands)

ZUIDERWIJK, EJ

The rotation period of HD 77581, supergiant primary in the X-ray binary Vela X-1, is determined from an analysis of selected absorption line profiles. The rotation rate determined from He I line profiles is 0.67 +/- 0.04 times that of the binary angular velocity, corresponding to a rotation velocity

Convergence in Sleep Time Accomplished? Gender Gap in Sleep Time for Middle-Aged Adults in Korea.

Science.gov (United States)

Cha, Seung-Eun; Eun, Ki-Soo

2018-04-19

Although the gender gap in sleep time has narrowed significantly in the last decade, middle-aged women between ages 35 and 60 still sleep less than their male counterparts in Korea. This study examines and provides evidence for factors contributing to the gender gap in this age group. Using Korean Time Use Survey (KTUS) data from 2004, 2009 and 2014, we find that middle-aged women’s difficulty in managing work-life balance and traditional role expectations placed upon women are the main causes of the gender gap in sleep time. The decomposition analysis reveals that the improved socioeconomic status and recent changes in familial expectations for women may have helped them sleep more than in the past. However, there remain fundamental differences in attitude and time use patterns between men and women that prevent middle-aged women from getting the same amount of sleep.

Nystagmus responses in a group of normal humans during earth-horizontal axis rotation

Science.gov (United States)

Wall, Conrad, III; Furman, Joseph M. R.

1989-01-01

Horizontal eye movement responses to earth-horizontal yaw axis rotation were evaluated in 50 normal human subjects who were uniformly distributed in age (20-69 years) and each age group was then divided by gender. Subjects were rotated with eyes open in the dark, using clockwise and counter-clockwise 60 deg velocity trapezoids. The nystagmus slow component velocity is analyzed. It is shown that, despite large intersubject variability, parameters which describe earth-horizontal yaw axis responses are loosely interrelated, and some of them vary significantly with gender and age.

General relativistic collapse of rotating stars

International Nuclear Information System (INIS)

Nakamura, T.

1984-01-01

When a rotating star begins to collapse, the gravity becomes so strong that there appears a region from which even a photon cannot escape. After the distortion of space-time is radiated as gravitational waves, a Kerr black hole is formed finally. One of the main goals for numerical relativity is to simulate the collapse of a rotating star under realistic conditions. However, to know both the dynamics of matter and the propagation of gravitational radiation seems to be very difficult. Therefore, in this paper the problem is divided into 4 stages. They are: (1) The time evolution of pure gravitational waves is calculated in a 2-D code. (2) In this stage, the author tries to understand the dynamics of a collapsing, rotating star in 2D code. (3) Combining the techniques from stages 1, 2, the author tries to know both the dynamics of matter and the propagation of gravitational waves generated by the nonspherical motion of matter. (4) The author simulates the gravitational collapse of a rotating star to a black hole in 3D. 25 references, 12 figures, 1 table

Reversibility of Supraspinatus Muscle Atrophy in Tendon-Bone Healing After Arthroscopic Rotator Cuff Repair.

Science.gov (United States)

Park, Yong Bok; Ryu, Ho Young; Hong, Jin Ho; Ko, Young Hoo; Yoo, Jae Chul

2016-04-01

To date, there are few reports of the definite reversibility of rotator cuff muscle atrophy after repair. To evaluate the reversibility of rotator cuff muscle atrophy after successful arthroscopic repair. Case series; Level of evidence, 4. Included in this study were 47 patients (mean age, 61.2 ± 7.3 years; range, 49-73 years) who underwent arthroscopic rotator cuff repair as well as magnetic resonance imaging (MRI) preoperatively and at 6-month and last follow-up. Patients who had confirmed rotator cuff healing (grades 1-3 according to the Sugaya classification) on both series of postoperative MRI were enrolled in the study. The mean time from the onset of symptoms to surgery was 24.7 ± 25.6 months (range, 3-120 months). The minimum follow-up was 2 years, and the mean follow-up duration was 41.8 ± 14.4 months. Serial changes in the supraspinatus muscle area on the most matching MRI scans (sagittal-oblique view) were evaluated. The area was measured by 2 independent observers. Both independent observers reported no significant difference in the area of the supraspinatus muscle between the preoperative time point and 6-month follow-up (observer 1: P = .135; observer 2: P = .189). However, there was a significant difference between the 6-month and last follow-up (mean, 41.8 months; observers 1 and 2: P .999) or from 6-month to final follow-up (P = .077). After successful arthroscopic rotator cuff repair, there was a slight (11.3%-13.9%) increase in muscle volume from preoperatively to final follow-up, as seen on serial MRI. Fatty infiltration according to the Goutallier grade was not reversed (P = .077). Some reversibility of supraspinatus muscle atrophy may exist in tendon-bone healing after arthroscopic rotator cuff repair; further follow-up is needed to better elucidate this result. © 2016 The Author(s).

Magnetic resonance described in the excitation dependent rotating frame of reference.

Science.gov (United States)

Tahayori, Bahman; Johnston, Leigh A; Mareels, Iven M Y; Farrell, Peter M

2008-01-01

An excitation dependent rotating frame of reference to observe the magnetic resonance phenomenon is introduced in this paper that, to the best of our knowledge, has not been used previously in the nuclear magnetic resonance context. The mathematical framework for this new rotating frame of reference is presented based on time scaling the Bloch equation after transformation to the classical rotating frame of reference whose transverse plane is rotating at the Larmor frequency. To this end, the Bloch equation is rewritten in terms of a magnetisation vector observed from the excitation dependent rotating frame of reference. The resultant Bloch equation is referred to as the time scaled Bloch equation. In the excitation dependent rotating frame of reference whose coordinates are rotating at the instantaneous Rabi frequency the observed magnetisation vector is a much slower signal than the true magnetisation in the rotating frame of reference. As a result the ordinary differential equation solvers have the ability to solve the time scaled version of the Bloch equation with a larger step size resulting in a smaller number of samples for solving the equation to a desired level of accuracy. The simulation results for different types of excitation are presented in this paper. This method may be used in true Bloch simulators in order to reduce the simulation time or increase the accuracy of the numerical solution. Moreover, the time scaled Bloch equation may be employed to determine the optimal excitation pattern in magnetic resonance imaging as well as designing pulses with better slice selectivity which is an active area of research in this field.

A novel rotational invariants target recognition method for rotating motion blurred images

Science.gov (United States)

Lan, Jinhui; Gong, Meiling; Dong, Mingwei; Zeng, Yiliang; Zhang, Yuzhen

2017-11-01

The imaging of the image sensor is blurred due to the rotational motion of the carrier and reducing the target recognition rate greatly. Although the traditional mode that restores the image first and then identifies the target can improve the recognition rate, it takes a long time to recognize. In order to solve this problem, a rotating fuzzy invariants extracted model was constructed that recognizes target directly. The model includes three metric layers. The object description capability of metric algorithms that contain gray value statistical algorithm, improved round projection transformation algorithm and rotation-convolution moment invariants in the three metric layers ranges from low to high, and the metric layer with the lowest description ability among them is as the input which can eliminate non pixel points of target region from degenerate image gradually. Experimental results show that the proposed model can improve the correct target recognition rate of blurred image and optimum allocation between the computational complexity and function of region.

Integrated rotating-compensator polarimeter for real-time measurements and analysis of organometallic chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Flock, K.; Kim, S.-J.; Asar, M.; Kim, I.K.; Aspnes, D.E

2004-05-01

We describe a single-beam rotating-compensator rotating-sample spectroscopic polarimeter (RCSSP) integrated with an organometallic chemical vapor deposition (OMCVD) reactor for in-situ diagnostics and control of epitaxial growth, and report representative results. The rotating compensator generates Fourier coefficients that provide information about layer thicknesses and compositions, while sample rotation provides information about optical anisotropy and therefore surface chemistry. We illustrate capabilities with various examples, including the simultaneous determination of <{epsilon}> and {alpha}{sub 10} during exposure of (001)GaAs to TMG, the heteroepitaxial growth of GaP on GaAs, and the growth of (001)GaSb with TMG and TMSb. Using a recently developed approach for quantitatively determining thickness and dielectric function of depositing layers, we find the presence of metallic Ga on TMG-exposed (001)GaAs. The (001)GaSb data show that Sb deposition is self-limiting, in contrast to expectations.

Use of a shoulder abduction brace after arthroscopic rotator cuff repair: A study on gait performance and falls.

Science.gov (United States)

Sonoda, Yuma; Nishioka, Takashi; Nakajima, Ryo; Imai, Shinji; Vigers, Piers; Kawasaki, Taku

2018-04-01

Fall prevention is essential in patients after arthroscopic rotator cuff repair because of the high risk of re-rupture. However, there are no reports related to falls that occur during the early postoperative period, while the affected limb is immobilized. This study assessed gait performance and falls in patients using a shoulder abduction brace after arthroscopic rotator cuff repair. Prospective cohort and postoperative repeated measures. This study included 29 patients (mean age, 67.1 ± 7.4 years) who underwent arthroscopic rotator cuff repair followed by rehabilitation. The timed up and go test, Geriatric Depression Scale, and Falls Efficacy Scale were measured, and the numbers of falls were compared between those shoulder abduction brace users and patients who had undergone total hip or knee arthroplasty. In arthroscopic rotator cuff repair patients, there were significant improvements in timed up and go test and Geriatric Depression Scale, but no significant differences in Falls Efficacy Scale, between the second and fifth postoperative weeks ( p rotator cuff repair patients fell more often than patients with total hip arthroplasty or total knee arthroplasty during the same period. The findings suggest that rehabilitation in arthroscopic rotator cuff repair patients is beneficial, but decreased gait performance due to the immobilizing shoulder abduction brace can lead to falls. Clinical relevance Although rehabilitation helps motor function and mental health after arthroscopic rotator cuff repair, shoulder abduction brace use is associated with impaired gait performance, high Falls Efficacy Scale scores, and risk of falls, so awareness of risk factors including medications and lower limb dysfunctions is especially important after arthroscopic rotator cuff repair.

The pace of aging: Intrinsic time scales in demography

Directory of Open Access Journals (Sweden)

Tomasz Wrycza

2014-05-01

Full Text Available Background: The pace of aging is a concept that captures the time-related aspect of aging. It formalizesthe idea of a characteristic life span or intrinsic population time scale. In the rapidly developing field of comparative biodemography, measures that account for inter-speciesdifferences in life span are needed to compare how species age. Objective: We aim to provide a mathematical foundation for the concept of pace. We derive desiredmathematical properties of pace measures and suggest candidates which satisfy these properties. Subsequently, we introduce the concept of pace-standardization, which reveals differences in demographic quantities that are not due to pace. Examples and consequences are discussed. Conclusions: Mean life span (i.e., life expectancy from birth or from maturity is intuitively appealing,theoretically justified, and the most appropriate measure of pace. Pace-standardizationprovides a serviceable method for comparative aging studies to explore differences indemographic patterns of aging across species, and it may considerably alter conclusionsabout the strength of aging.

Determining optimum aging time using novel core flooding equipment

DEFF Research Database (Denmark)

Ahkami, Mehrdad; Chakravarty, Krishna Hara; Xiarchos, Ioannis

2016-01-01

the optimum aging time regardless of variations in crude oil, rock, and brine properties. State of the art core flooding equipment has been developed that can be used for consistently determining the resistivity of the coreplug during aging and waterflooding using advanced data acquisition software......New methods for enhanced oil recovery are typically developed using core flooding techniques. Establishing reservoir conditions is essential before the experimental campaign commences. The realistic oil-rock wettability can be obtained through optimum aging of the core. Aging time is affected....... In the proposed equipment, independent axial and sleeve pressure can be applied to mimic stresses at reservoir conditions. 10 coreplugs (four sandstones and six chalk samples) from the North Sea have been aged for more than 408 days in total and more than 29000 resistivity data points have been measured...

Muscle atrophy as a consequence of rotator cuff tears: should we compare the muscles of the rotator cuff with those of the deltoid?

Energy Technology Data Exchange (ETDEWEB)

Ashry, Reem; Schweitzer, Mark E.; Cunningham, Patricia; Cohen, Jodi; Babb, James; Cantos, Andrew [Hospital for Joint Diseases, NYU Medical Center, Department of Radiology, New York, NY (United States)

2007-09-15

The quantitative assessment of muscle atrophy has a degree of importance in prognosticating rotator cuff treatment. However, it has been conjectured that muscle fat increases with aging. Therefore, we thought that the quantitative assessment of the supraspinatous would be better if made in comparison with a standard of reference such as the deltoid. Consequently, we performed a two-part study, first evaluating supraspinatous changes compared with the deltoid in ''normals'' with aging, and second, determining if in patients with cuff tears the supraspinatous fat exceeds that of the deltoid. In part 1, we studied 50 patients stratified by decade. In the first sitting, two blinded independent observers quantitatively graded the deltoid (with the supraspinatous obscured) and in the second sitting the same two observers quantitatively graded the supraspinatous (with the deltoid obscured). In part 2 of the study, we evaluated patients with moderate rotator cuff tears (>2 cm) and performed the same blinded, two-sitting, quantitative assessment (with the comparison muscle obscured). We found that muscle atrophy increases with age in patients without tears (0.011/0.028 U/year), although to a greater degree in the deltoid (p = 0.032). Also, in similarly aged patients, quantitative scores of the deltoid closely matched those of the supraspinatous (p = 0.071). Notably, however, in patients with large tears, the supraspinatous showed significant changes disproportionate to those of the deltoid, regardless of patient age (p = 0.044). In the presence of a normal rotator cuff, fatty infiltration increases with age. Age-related changes occur more frequently in the deltoid, verifying this muscle's potential as a standard of reference. With cuff tears, supraspinatous atrophy was disproportionate to that of the deltoid. Therefore, systematic assessment of supraspinatous muscle atrophy may be more reliable using the deltoid as a control for comparison than

Muscle atrophy as a consequence of rotator cuff tears: should we compare the muscles of the rotator cuff with those of the deltoid?

International Nuclear Information System (INIS)

Ashry, Reem; Schweitzer, Mark E.; Cunningham, Patricia; Cohen, Jodi; Babb, James; Cantos, Andrew

2007-01-01

The quantitative assessment of muscle atrophy has a degree of importance in prognosticating rotator cuff treatment. However, it has been conjectured that muscle fat increases with aging. Therefore, we thought that the quantitative assessment of the supraspinatous would be better if made in comparison with a standard of reference such as the deltoid. Consequently, we performed a two-part study, first evaluating supraspinatous changes compared with the deltoid in ''normals'' with aging, and second, determining if in patients with cuff tears the supraspinatous fat exceeds that of the deltoid. In part 1, we studied 50 patients stratified by decade. In the first sitting, two blinded independent observers quantitatively graded the deltoid (with the supraspinatous obscured) and in the second sitting the same two observers quantitatively graded the supraspinatous (with the deltoid obscured). In part 2 of the study, we evaluated patients with moderate rotator cuff tears (>2 cm) and performed the same blinded, two-sitting, quantitative assessment (with the comparison muscle obscured). We found that muscle atrophy increases with age in patients without tears (0.011/0.028 U/year), although to a greater degree in the deltoid (p 0.032). Also, in similarly aged patients, quantitative scores of the deltoid closely matched those of the supraspinatous (p = 0.071). Notably, however, in patients with large tears, the supraspinatous showed significant changes disproportionate to those of the deltoid, regardless of patient age (p = 0.044). In the presence of a normal rotator cuff, fatty infiltration increases with age. Age-related changes occur more frequently in the deltoid, verifying this muscle's potential as a standard of reference. With cuff tears, supraspinatous atrophy was disproportionate to that of the deltoid. Therefore, systematic assessment of supraspinatous muscle atrophy may be more reliable using the deltoid as a control for comparison than assessing it in isolation

Variability of OH rotational temperatures on time scales from hours to 15 years by kinetic temperature variations, emission layer changes, and non-LTE effects

Science.gov (United States)

Noll, Stefan

2016-07-01

Rotational temperatures derived from hydroxyl (OH) line emission are frequently used to study atmospheric temperatures at altitudes of about 87 km. While the measurement only requires intensities of a few bright lines of an OH band, the interpretation can be complicated. Ground-based temperatures are averages for the entire, typically 8 km wide emission layer. Variations in the rotational temperature are then caused by changes of the kinetic temperature and the OH emission profile. The latter can also be accompanied by differences in the layer-averaged efficiency of the thermalisation of the OH rotational level populations. Since this especially depends on the frequency of collisions with O_2, which is low at high altitudes, the non-local thermodynamic equilibrium (non-LTE) contribution to the measured temperatures can be significant and variable. In order to understand the impact of the different sources of OH rotational temperature variations from time scales of hours to a solar cycle, we have studied spectra from the astronomical echelle spectrographs X-shooter and UVES located at Cerro Paranal in Chile. While the X-shooter data spanning 3.5 years allowed us to measure temperatures for 25 OH and two O_2 bands, the UVES spectra cover no more than 10 OH bands simultaneously but a period of about 15 years. These data have been complemented by kinetic temperature and OH and O_2 emission profiles from the multi-channel radiometer SABER on the TIMED satellite. Taking the O_2 and SABER kinetic temperatures as reference and considering the different band-dependent emission profiles, we could evaluate the contribution of non-LTE effects to the measured OH rotational temperatures depending on line set, band, and time. Non-LTE contributions are significant for most bands and can exceed 10 K. The amplitudes of their average nocturnal and seasonal variation are of the order of 1 to 2 K.

Enstrophy-based proper orthogonal decomposition of flow past rotating cylinder at super-critical rotating rate

Science.gov (United States)

Sengupta, Tapan K.; Gullapalli, Atchyut

2016-11-01

Spinning cylinder rotating about its axis experiences a transverse force/lift, an account of this basic aerodynamic phenomenon is known as the Robins-Magnus effect in text books. Prandtl studied this flow by an inviscid irrotational model and postulated an upper limit of the lift experienced by the cylinder for a critical rotation rate. This non-dimensional rate is the ratio of oncoming free stream speed and the surface speed due to rotation. Prandtl predicted a maximum lift coefficient as CLmax = 4π for the critical rotation rate of two. In recent times, evidences show the violation of this upper limit, as in the experiments of Tokumaru and Dimotakis ["The lift of a cylinder executing rotary motions in a uniform flow," J. Fluid Mech. 255, 1-10 (1993)] and in the computed solution in Sengupta et al. ["Temporal flow instability for Magnus-robins effect at high rotation rates," J. Fluids Struct. 17, 941-953 (2003)]. In the latter reference, this was explained as the temporal instability affecting the flow at higher Reynolds number and rotation rates (>2). Here, we analyze the flow past a rotating cylinder at a super-critical rotation rate (=2.5) by the enstrophy-based proper orthogonal decomposition (POD) of direct simulation results. POD identifies the most energetic modes and helps flow field reconstruction by reduced number of modes. One of the motivations for the present study is to explain the shedding of puffs of vortices at low Reynolds number (Re = 60), for the high rotation rate, due to an instability originating in the vicinity of the cylinder, using the computed Navier-Stokes equation (NSE) from t = 0 to t = 300 following an impulsive start. This instability is also explained through the disturbance mechanical energy equation, which has been established earlier in Sengupta et al. ["Temporal flow instability for Magnus-robins effect at high rotation rates," J. Fluids Struct. 17, 941-953 (2003)].

Diameter Growth, Biological Rotation Age and Biomass of Chinese Fir in Burning and Clearing Site Preparations in Subtropical China

Directory of Open Access Journals (Sweden)

Hua Zhou

2016-08-01

Full Text Available Sustained forest management of Cunninghamia lanceolata (Chinese fir plantations in subtropical China is restricted by the limited availability of quantitative data. This study combines inventory data and tree-ring analysis of Chinese fir from natural and plantation forests that were subjected to controlled burning or brush clearing site preparations. Inter-annual variation of Chinese fir tree-ring widths were measured for the controlled burning, brush clearing and natural forest sites. The mean annual diametric growth of Chinese fir was 0.56 cm·year−1 for the natural forest, 0.80 cm·year−1 for the brush clearing site and 1.10 cm·year−1 for the controlled burning site. The time needed to reach the minimum cutting/logging diameter of 15 cm was 14 years in the controlled burning site, 19 years in the brush clearing site and >40 years in the natural forest. The biological rotation ages for the burning, cutting and natural forest sites were 15, 26 and >100 years, respectively. The total aboveground biomasses for the burning and clearing sites were 269.8 t·ha−1 and 252 t·ha−1, respectively. These results suggest that the current 25-year cutting cycle greatly underestimates the growth rate of Chinese fir plantations.

Surgical Pathology Resident Rotation Restructuring at a Tertiary Care Academic Center.

Science.gov (United States)

Mehr, Chelsea R; Obstfeld, Amrom E; Barrett, Amanda C; Montone, Kathleen T; Schwartz, Lauren E

2017-01-01

Changes in the field of pathology and resident education necessitate ongoing evaluation of residency training. Evolutionary change is particularly important for surgical pathology rotations, which form the core of anatomic pathology training programs. In the past, we organized this rotation based on subjective insight. When faced with the recent need to restructure the rotation, we strove for a more evidence-based process. Our approach involved 2 primary sources of data. We quantified the number of cases and blocks submitted per case type to estimate workload and surveyed residents about the time required to gross specimens in all organ systems. A multidisciplinary committee including faculty, residents, and staff evaluated the results and used the data to model how various changes to the rotation would affect resident workload, turnaround time, and other variables. Finally, we identified rotation structures that equally distributed work and created a point-based system that capped grossing time for residents of different experience. Following implementation, we retrospectively compared turnaround time and duty hour violations before and after these changes and surveyed residents about their experiences with both systems. We evaluated the accuracy of the point-based system by examining grossing times and comparing them to the assigned point values. We found overall improvement in the rotation following the implementation. As there is essentially no literature on the subject of surgical pathology rotation organization, we hope that our experience will provide a road map to improve pathology resident education at other institutions.

Surgical Pathology Resident Rotation Restructuring at a Tertiary Care Academic Center

Directory of Open Access Journals (Sweden)

Chelsea R. Mehr MD

2017-11-01

Full Text Available Changes in the field of pathology and resident education necessitate ongoing evaluation of residency training. Evolutionary change is particularly important for surgical pathology rotations, which form the core of anatomic pathology training programs. In the past, we organized this rotation based on subjective insight. When faced with the recent need to restructure the rotation, we strove for a more evidence-based process. Our approach involved 2 primary sources of data. We quantified the number of cases and blocks submitted per case type to estimate workload and surveyed residents about the time required to gross specimens in all organ systems. A multidisciplinary committee including faculty, residents, and staff evaluated the results and used the data to model how various changes to the rotation would affect resident workload, turnaround time, and other variables. Finally, we identified rotation structures that equally distributed work and created a point-based system that capped grossing time for residents of different experience. Following implementation, we retrospectively compared turnaround time and duty hour violations before and after these changes and surveyed residents about their experiences with both systems. We evaluated the accuracy of the point-based system by examining grossing times and comparing them to the assigned point values. We found overall improvement in the rotation following the implementation. As there is essentially no literature on the subject of surgical pathology rotation organization, we hope that our experience will provide a road map to improve pathology resident education at other institutions.

Multiscale singular value manifold for rotating machinery fault diagnosis

Energy Technology Data Exchange (ETDEWEB)

Feng, Yi; Lu, BaoChun; Zhang, Deng Feng [School of Mechanical Engineering, Nanjing University of Science and Technology,Nanjing (United States)

2017-01-15

Time-frequency distribution of vibration signal can be considered as an image that contains more information than signal in time domain. Manifold learning is a novel theory for image recognition that can be also applied to rotating machinery fault pattern recognition based on time-frequency distributions. However, the vibration signal of rotating machinery in fault condition contains cyclical transient impulses with different phrases which are detrimental to image recognition for time-frequency distribution. To eliminate the effects of phase differences and extract the inherent features of time-frequency distributions, a multiscale singular value manifold method is proposed. The obtained low-dimensional multiscale singular value manifold features can reveal the differences of different fault patterns and they are applicable to classification and diagnosis. Experimental verification proves that the performance of the proposed method is superior in rotating machinery fault diagnosis.

Medical Student Experiences on Consultation-Liaison Psychiatry Rotations: A Nationwide Survey.

Science.gov (United States)

Meyer, Fremonta; Abbasi, Omair; Kasick, David; Lee, Kewchang; Pelic, Christine; Zinser, Jennifer; Harris, Thomas; Funk, Margo

Consultation-liaison (C-L) psychiatry clerkship rotations may improve medical students' understanding of psychiatric principles relevant to the settings in which they will ultimately practice. This study aimed to characterize students' experiences on C-L rotations. This cross-sectional survey study, sponsored by the Academy of Psychosomatic Medicine Subcommittee on Medical Student Education, was conducted at 5 US medical schools between 2012 and 2016. After the C-L rotation, students completed a voluntary 17-item survey. A total of 235 surveys were collected (mean response rate = 92%). The most frequently endorsed benefit of C-L was learning to manage psychiatric disorders in the context of medical illness (89%). The most frequently endorsed drawback was inconsistent/excessively variable workload (40%). Overall, 82% of respondents recommended C-L to other students; 80% reported that the ideal clerkship would include exposure to both C-L and inpatient psychiatry. Overall, 38% reported that their C-L experience increased their interest in psychiatry as a career. Effect of C-L on interest in psychiatry did not differ by study site, age, sex, clerkship length, or time spent on C-L. Respondents who noted more positive role-modeling on C-L compared to other clerkship rotations were more likely to report increased interest in a psychiatry career (odds ratio = 2.70). Most medical students perceive C-L rotations favorably. Positive role modeling may increase their consideration of psychiatry specialization. The findings that C-L rotation length did not correlate with attitudes and that most students preferred exposure to both inpatient and C-L psychiatry suggest that C-L exposure can beneficially be integrated into core clerkships containing other elements. Copyright © 2018 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

Real-time Monitoring System for Rotating Machinery with IoT-based Cloud Platform

Energy Technology Data Exchange (ETDEWEB)

Jeong, Haedong; Kim, Suhyun; Woo, Sunhee; Kim, Songhyun; Lee, Seungchul [Ulsan Nat’l Institute Science and Technology, Ulsan (Korea, Republic of)

2017-06-15

The objective of this research is to improve the efficiency of data collection from many machine components on smart factory floors using IoT(Internet of things) techniques and cloud platform, and to make it easy to update outdated diagnostic schemes through online deployment methods from cloud resources. The short-term analysis is implemented by a micro-controller, and it includes machine-learning algorithms for inferring snapshot information of the machine components. For long-term analysis, time-series and high-dimension data are used for root cause analysis by combining a cloud platform and multivariate analysis techniques. The diagnostic results are visualized in a webbased display dashboard for an unconstrained user access. The implementation is demonstrated to identify its performance in data acquisition and analysis for rotating machinery.

Real-time Monitoring System for Rotating Machinery with IoT-based Cloud Platform

International Nuclear Information System (INIS)

Jeong, Haedong; Kim, Suhyun; Woo, Sunhee; Kim, Songhyun; Lee, Seungchul

2017-01-01

The objective of this research is to improve the efficiency of data collection from many machine components on smart factory floors using IoT(Internet of things) techniques and cloud platform, and to make it easy to update outdated diagnostic schemes through online deployment methods from cloud resources. The short-term analysis is implemented by a micro-controller, and it includes machine-learning algorithms for inferring snapshot information of the machine components. For long-term analysis, time-series and high-dimension data are used for root cause analysis by combining a cloud platform and multivariate analysis techniques. The diagnostic results are visualized in a webbased display dashboard for an unconstrained user access. The implementation is demonstrated to identify its performance in data acquisition and analysis for rotating machinery.

Multiple operating system rotation environment moving target defense

Science.gov (United States)

Evans, Nathaniel; Thompson, Michael

2016-03-22

Systems and methods for providing a multiple operating system rotation environment ("MORE") moving target defense ("MTD") computing system are described. The MORE-MTD system provides enhanced computer system security through a rotation of multiple operating systems. The MORE-MTD system increases attacker uncertainty, increases the cost of attacking the system, reduces the likelihood of an attacker locating a vulnerability, and reduces the exposure time of any located vulnerability. The MORE-MTD environment is effectuated by rotation of the operating systems at a given interval. The rotating operating systems create a consistently changing attack surface for remote attackers.

Collapse and equilibrium of rotating, adiabatic clouds

International Nuclear Information System (INIS)

Boss, A.P.

1980-01-01

A numerical hydrodynamics computer code has been used to follow the collapse and establishment of equilibrium of adiabatic gas clouds restricted to axial symmetry. The clouds are initially uniform in density and rotation, with adiabatic exponents γ=5/3 and 7/5. The numerical technique allows, for the first time, a direct comparison to be made between the dynamic collapse and approach to equilibrium of unconstrained clouds on the one hand, and the results for incompressible, uniformly rotating equilibrium clouds, and the equilibrium structures of differentially rotating polytropes, on the other hand

Effects of Sustained Otolith-Only Stimulation on Post-Rotational Nystagmus.

Science.gov (United States)

Shaikh, Aasef G; Solomon, David

2017-06-01

Constant velocity rotations in darkness evoke vestibulo-ocular reflex in form of pre- and post-rotational nystagmus under cerebellar supervision. Reorientation of the head with respect to gravity, stimulating otolith and semicircular canal, during post-rotational phase rapidly suppresses the post-rotational nystagmus. We asked if pure otolith stimulation without semicircular canal signal is sufficient for the suppression of post-rotational nystagmus. The experimental paradigm comprised of on-axis rotations in the horizontal plane when the subject was sitting upright, followed by a novel stimulus that combined off-axis centrifugation in the horizontal plane with amplitude matched, yet out-of-phase, on-axis horizontal rotation-double centrifugation. The resultant effect of double centrifugation was pure otolith stimulation that constantly changed direction, yet completely canceled out angular velocity (no horizontal semicircular canal stimulation). Double centrifugation without pre-existing on-axis rotations evoked mixture of horizontal and vertical eye movements, latter reflected the known uncertainty of the vestibular system to differentiate whether the sensory signal is related to low-frequency translations in horizontal plane or head tilts relative to the gravity. Double centrifugation during post-rotational phase suppressed the peak slow phase eye velocity of the post-rotational nystagmus, hence affecting the vestibular ocular reflex gain (eye velocity/head velocity) matrix. The decay time constant, however, was unchanged. Amount of suppression of the peak slow phase eye velocity of the post-rotational nystagmus during double centrifugation correlated with the peak vertical eye velocity evoked by the pure otolith stimuli in the absence of pre-existing on axis rotations. In post-rotational phase, the pure otolith signal affects vestibular ocular reflex gain matrix but does not affect the time constant.

Establishing Maximal Medical Improvement After Arthroscopic Rotator Cuff Repair.

Science.gov (United States)

Zuke, William A; Leroux, Timothy S; Gregory, Bonnie P; Black, Austin; Forsythe, Brian; Romeo, Anthony A; Verma, Nikhil N

2018-03-01

As health care transitions from a pay-for-service to a pay-for-performance infrastructure, the value of orthopaedic care must be defined accurately. Significant efforts have been made in defining quality and cost in arthroplasty; however, there remains a lag in ambulatory orthopaedic care. Two-year follow-up has been a general requirement for reporting outcomes after rotator cuff repair. However, this time requirement has not been established scientifically and is of increasing importance in the era of value-based health care. Given that arthroscopic rotator cuff repair is a common ambulatory orthopaedic procedure, the purpose of this study was to establish a time frame for maximal medical improvement (the state when improvement has stabilized) after arthroscopic rotator cuff repair. Systematic review. A systematic review of the literature was conducted, identifying studies reporting sequential patient-reported outcomes up to a minimum of 2 years after arthroscopic rotator cuff repair. The primary clinical outcome was patient-reported outcomes at 3-month, 6-month, 1-year, and 2-year follow-up. Secondary clinical outcomes included range of motion, strength, retears, and complications. Clinically significant improvement was determined between various time intervals by use of the minimal clinically important difference. The review included 19 studies including 1370 patients who underwent rotator cuff repair. Clinically significant improvement in patient-reported outcomes was seen up to 1 year after rotator cuff repair, but no clinical significance was noted from 1 year to 2 years. The majority of improvement in strength and range of motion was seen up to 6 months, but no clinically meaningful improvement was seen thereafter. All reported complications and the majority of retears occurred within 6 months after rotator cuff repair. After rotator cuff repair, a clinically significant improvement in patient-reported outcomes, range of motion, and strength was seen up to 1

Rotational and radial velocities of 1.3-2.2 M {sub ☉} red giants in open clusters

Energy Technology Data Exchange (ETDEWEB)

Carlberg, Joleen K., E-mail: jcarlberg@dtm.ciw.edu [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States)

2014-06-01

This study presents the rotational distribution of red giant (RG) stars in 11 old to intermediate age open clusters. The masses of these stars are all above the Kraft break, so they lose negligible amounts of their birth angular momentum (AM) during the main-sequence (MS) evolution. However, they do span a mass range with quite different AM distributions imparted during formation, with the stars less massive than ∼1.6M {sub ☉} arriving on the MS with lower rotation rates than the more massive stars. The majority of RGs in this study are slow rotators across the entire red giant branch regardless of mass, supporting the picture that intermediate-mass stars rapidly spin down when they evolve off the MS and develop convection zones capable of driving a magnetic dynamo. Nevertheless, a small fraction of RGs in open clusters show some level of enhanced rotation, and faster rotators are as common in these clusters as in the field RG population. Most of these enhanced rotators appear to be red clump stars, which is also true of the underlying stellar sample, while others are clearly RGs that are above or below the clump. In addition to rotational velocities, the radial velocities (RVs) and membership probabilities of individual stars are also presented. Cluster heliocentric RVs for NGC 6005 and Pismis 18 are reported for the first time.

[Risk factors for the development of rotator cuff tears in individuals with paraplegia : A cross-sectional study].

Science.gov (United States)

Pepke, W; Brunner, M; Abel, R; Almansour, H; Gerner, H J; Hug, A; Zeifang, F; Kentar, Y; Bruckner, T; Akbar, M

2018-02-27

Shoulder pain and rotator cuff tears are highly prevalent among wheelchair dependent individuals with paraplegia. The purpose of this study was to identify potential risk factors associated with the development of rotator cuff tears in this population. A total of 217 wheelchair dependent individuals with paraplegia were included in this cross-sectional study (level of evidence III). The mean age of this population was 47.9 years and the mean duration of wheelchair dependence was 24.1 years. Each individual was asked to complete a questionnaire designed to identify risk factors for rotator cuff tears and underwent a standardized clinical examination with the documentation of the Constant-Murley shoulder outcome score and magnetic resonance imaging (MRI) of both shoulder joints. MRI analysis revealed at least one rotator cuff tear in 93 patients (43%). Multiple logistic regression analysis identified the following factors to be associated with the presence of rotator cuff tear: patient age, duration of spinal cord injury/wheelchair dependence, gender, and wheelchair athletic activity. Neither BMI nor the level of spinal cord injury was found to pose a risk factor in the population studied. With respect to patient age, the risk of developing a rotator cuff tear increased by 11% per annum. In terms of duration of spinal cord injury, the analysis revealed a 6% increased risk per year of wheelchair dependence (OR = 1.06). Females had a 2.6-fold higher risk of developing rotator cuff tears than males and wheelchair sport activity increased the risk 2.3-fold. There is a high prevalence of rotator cuff tears in wheel-chair dependent persons with paraplegia. Risk factors such as age, gender, duration of paraplegia, and wheel chair sport activity seem to play an important role in the development of rotator cuff tears.

M Dwarf Rotation from the K2 Young Clusters to the Field. I. A Mass-Rotation Correlation at 10 Myr

Science.gov (United States)

Somers, Garrett; Stauffer, John; Rebull, Luisa; Cody, Ann Marie; Pinsonneault, Marc

2017-12-01

Recent observations of the low-mass (0.1-0.6 {M}⊙ ) rotation distributions of the Pleiades and Praesepe clusters have revealed a ubiquitous correlation between mass and rotation, such that late M dwarfs rotate an order-of-magnitude faster than early M dwarfs. In this paper, we demonstrate that this mass-rotation correlation is present in the 10 Myr Upper Scorpius association, as revealed by new K2 rotation measurements. Using rotational evolution models, we show that the low-mass rotation distribution of the 125 Myr Pleiades cluster can only be produced if it hosted an equally strong mass-rotation correlation at 10 Myr. This suggests that physical processes important in the early pre-main sequence (PMS; star formation, accretion, disk-locking) are primarily responsible for the M dwarf rotation morphology, and not quirks of later angular momentum (AM) evolution. Such early mass trends must be taken into account when constructing initial conditions for future studies of stellar rotation. Finally, we show that the average M star loses ˜25%-40% of its AM between 10 and 125 Myr, a figure accurately and generically predicted by modern solar-calibrated wind models. Their success rules out a lossless PMS and validates the extrapolation of magnetic wind laws designed for solar-type stars to the low-mass regime at early times.

Shoulder-Rotator Strength, Range of Motion, and Acromiohumeral Distance in Asymptomatic Adolescent Volleyball Attackers.

Science.gov (United States)

Harput, Gulcan; Guney, Hande; Toprak, Ugur; Kaya, Tunca; Colakoglu, Fatma Filiz; Baltaci, Gul

2016-09-01

Sport-specific adaptations at the glenohumeral joint could occur in adolescent athletes because they start participating in high-performance sports in early childhood. To investigate shoulder-rotator strength, internal-rotation (IR) and external-rotation (ER) range of motion (ROM), and acromiohumeral distance (AHD) in asymptomatic adolescent volleyball attackers to determine if they have risk factors for injury. Cross-sectional study. University laboratory. Thirty-nine adolescent high school-aged volleyball attackers (22 boys, 17 girls; age = 16.0 ± 1.4 years, height = 179.2 ± 9.0 cm, mass = 67.1 ± 10.9 kg, body mass index = 20.7 ± 2.6 kg/m 2 ). Shoulder IR and ER ROM, total-rotation ROM, glenohumeral IR deficit, AHD, and concentric and eccentric strength of the shoulder internal and external rotators were tested bilaterally. External-rotation ROM was greater (t 38 = 4.92, P 18°). We observed greater concentric internal-rotator (t 38 = 2.89, P = .006) and eccentric external-rotator (t 38 = 2.65, P = .01) strength in the dominant than in the nondominant shoulder. The AHD was less in the dominant shoulder (t 38 = -3.60, P volleyball attackers demonstrated decreased IR ROM, total ROM, and AHD and increased ER ROM in their dominant shoulder. Therefore, routine screening of adolescent athletes and designing training programs for hazardous adaptive changes could be important in preventing shoulder injuries.

Visual and Haptic Mental Rotation

Directory of Open Access Journals (Sweden)

Satoshi Shioiri

2011-10-01

Full Text Available It is well known that visual information can be retained in several types of memory systems. Haptic information can also be retained in a memory because we can repeat a hand movement. There may be a common memory system for vision and action. On the one hand, it may be convenient to have a common system for acting with visual information. On the other hand, different modalities may have their own memory and use retained information without transforming specific to the modality. We compared memory properties of visual and haptic information. There is a phenomenon known as mental rotation, which is possibly unique to visual representation. The mental rotation is a phenomenon where reaction time increases with the angle of visual target (eg,, a letter to identify. The phenomenon is explained by the difference in time to rotate the representation of the target in the visual sytem. In this study, we compared the effect of stimulus angle on visual and haptic shape identification (two-line shapes were used. We found that a typical effect of mental rotation for the visual stimulus. However, no such effect was found for the haptic stimulus. This difference cannot be explained by the modality differences in response because similar difference was found even when haptical response was used for visual representation and visual response was used for haptic representation. These results indicate that there are independent systems for visual and haptic representations.

Stellar dynamism. Activity and rotation of solar stars observed from the Kepler satellite

International Nuclear Information System (INIS)

Ceillier, Tugdual

2015-01-01

This thesis concerns the study of seismic solar-like stars' rotation and magnetic activity. We use data from the Kepler satellite to study the rotational history of these stars throughout their evolution. This allows to have a more complete picture of stellar rotation and magnetism. In the first part, we present the context of this PhD: astro-seismology, the seismic study of stars. We continue by describing the tool we developed to measure surface rotation of stars using photometric data from Kepler. We compare it to other methodologies used by the community and show that its efficiency is very high. In the second part, we apply this tool to around 500 main-sequence and sub-giant solar-like stars. We measure surface rotation periods and activity levels for 300 of them. We show that the measured periods and the ages from astro-seismology do not agree well with the standard period-age relationships and propose to modify these relationships for stars older than the Sun. We also use the surface rotation as a constraint to estimate the internal rotation of a small number of seismic targets. We demonstrate that these stars have, like the Sun, a very low differential rotation ratio. In the third part, we apply our surface rotation-measuring tool to the most extensive sample of red giants observed by Kepler, comprising more than 17,000 stars. We identify more than 360 fast rotating red giants and compare our detection rates with the ones predicted by theory to better understand the reasons for this rapid rotation. We also use stellar modelling to reproduce the internal rotation profile of a particular red giant. This allows us to emphasize how important implementing new angular momentum transport mechanisms in stellar evolution codes is. This work offers new results that are useful to a very wide community of stellar physicists. It also puts strong constraints on the evolution of solar-like stars' rotation and magnetic activity. (author) [fr

Coherent distributions for the rigid rotator

Energy Technology Data Exchange (ETDEWEB)

Grigorescu, Marius [CP 15-645, Bucharest 014700 (Romania)

2016-06-15

Coherent solutions of the classical Liouville equation for the rigid rotator are presented as positive phase-space distributions localized on the Lagrangian submanifolds of Hamilton-Jacobi theory. These solutions become Wigner-type quasiprobability distributions by a formal discretization of the left-invariant vector fields from their Fourier transform in angular momentum. The results are consistent with the usual quantization of the anisotropic rotator, but the expected value of the Hamiltonian contains a finite “zero point” energy term. It is shown that during the time when a quasiprobability distribution evolves according to the Liouville equation, the related quantum wave function should satisfy the time-dependent Schrödinger equation.

Rotation and solvation of ammonium ion

International Nuclear Information System (INIS)

Perrin, C.L.; Gipe, R.K.

1987-01-01

From nitrogen-15 spin-lattice relaxation times and nuclear Overhauser enhancements, the rotational correlations time tau/sub c/ for 15 NH 4 + was determined in s series of solvents. Values of tau/sub c/ range from 0.46 to 20 picoseconds. The solvent dependent of tau/sub c/ cannot be explained in terms of solvent polarity, molecular dipole moment, solvent basicity, solvent dielectric relaxation, or solvent viscosity. The rapid rotation and the variation with solvent can be accounted for by a model that involves hydrogen bonding of an NH proton to more than one solvent molecule in a disordered solvation environment. 25 references, 1 table

Risk Factors, Pathobiomechanics and Physical Examination of Rotator Cuff Tears

Science.gov (United States)

Moulton, Samuel G.; Greenspoon, Joshua A.; Millett, Peter J.; Petri, Maximilian

2016-01-01

Background: It is important to appreciate the risk factors for the development of rotator cuff tears and specific physical examination maneuvers. Methods: A selective literature search was performed. Results: Numerous well-designed studies have demonstrated that common risk factors include age, occupation, and anatomic considerations such as the critical shoulder angle. Recently, research has also reported a genetic component as well. The rotator cuff axially compresses the humeral head in the glenohumeral joint and provides rotational motion and abduction. Forces are grouped into coronal and axial force couples. Rotator cuff tears are thought to occur when the force couples become imbalanced. Conclusion: Physical examination is essential to determining whether a patient has an anterosuperior or posterosuperior tear. Diagnostic accuracy increases when combining a series of examination maneuvers. PMID:27708731

Vibrational and Rotational Energy Relaxation in Liquids

DEFF Research Database (Denmark)

Petersen, Jakob

Vibrational and rotational energy relaxation in liquids are studied by means of computer simulations. As a precursor for studying vibrational energy relaxation of a solute molecule subsequent to the formation of a chemical bond, the validity of the classical Bersohn-Zewail model for describing......, the vibrational energy relaxation of I2 subsequent to photodissociation and recombination in CCl4 is studied using classical Molecular Dynamics simulations. The vibrational relaxation times and the time-dependent I-I pair distribution function are compared to new experimental results, and a qualitative agreement...... is found in both cases. Furthermore, the rotational energy relaxation of H2O in liquid water is studied via simulations and a power-and-work analysis. The mechanism of the energy transfer from the rotationally excited H2O molecule to its water neighbors is elucidated, i.e. the energy-accepting degrees...

U-shape rotating anti-cathode compact X-ray generator: 20 times stronger than the commercially available X-ray source

Energy Technology Data Exchange (ETDEWEB)

Sakabe, N., E-mail: sakabe-dsb@sbsp.jp; Sakabe, K. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Foundation for Advancement of International Science (FAIS), Kasuga 3-chome, Tsukuba, Ibaraki 305-0821 (Japan); Ohsawa, S.; Sakai, T.; Kobayakawa, H.; Sugimura, T.; Ikeda, M.; Tawada, M. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Watanabe, N.; Sasaki, K. [Nagoya University, Chikusa, Nagoya, Aichi 464-8603 (Japan); Wakatsuki, M. [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8568 (Japan)

2013-11-01

A new type of U-shape anti-cathode X-ray generator in which the inner surface of a cylindrical target is irradiated by an electron beam has been made by modifying a conventional rotating anti-cathode X-ray generator whose brightness in the catalog is 12 kW mm{sup −2}. A brightness of 129 kW mm{sup −2} was thereby obtained with this new U-shape-type X-ray generator. This new X-ray generator is expected to be of keen interest for applications in academia, industry and in hospitals. A new type of U-shape anti-cathode X-ray generator in which the inner surface of a cylindrical target is irradiated by an electron beam has been made by modifying a conventional rotating anti-cathode X-ray generator whose brightness in the catalog is 12 kW mm{sup −2}. The target material (Cu), target radius (50 mm) and rotating speed (6000 r.p.m.) were not changed in this modification. A brightness of 52 kW mm{sup −2} was obtained by this U-shape-type X-ray generator. This means that the brightness of the new type is 4.3 times greater than that of the old unmodified one. Furthermore, the new-type X-ray generator yielded a brightness of 129 kW mm{sup −2} by adding a carbon coating on the Cu target. This means an overall increase of brightness of ten times. The original generator has the highest brightness in the generators of the same class (having a radius of 50 mm and rotation speed of 6000 r.p.m.). Observations showed that Cu Kα counts at vertical incidence of the electron beam onto the surface of the new target, which is initially optically smooth, decrease as the surface is roughened by a severe thermal stress caused by strong electron beam exposure. Further observation reveals, however, that oblique incidence of the electron beam onto the roughened surface drastically increased the X-ray output and amounts to twice as much as that from a smooth surface at vertical incidence. Thus, at the present stage, an overall increase of brightness has been realised at a level 20 times

DISK BRAKING IN YOUNG STARS: PROBING ROTATION IN CHAMAELEON I AND TAURUS-AURIGA

International Nuclear Information System (INIS)

Duy Cuong Nguyen; Jayawardhana, Ray; Van Kerkwijk, Marten H.; Damjanov, Ivana; Brandeker, Alexis; Scholz, Alexander

2009-01-01

We present a comprehensive study of rotation, disk, and accretion signatures for 144 T Tauri stars in the young (∼2 Myr old) Chamaeleon I and Taurus-Auriga star-forming regions based on multi-epoch high-resolution optical spectra from the Magellan Clay 6.5 m telescope supplemented by mid-infrared photometry from the Spitzer Space Telescope. In contrast to previous studies in the Orion Nebula Cluster and NGC 2264, we do not see a clear signature of disk braking in Tau-Aur and Cha I. We find that both accretors and non-accretors have similar distributions of vsin i. This result could be due to different initial conditions, insufficient time for disk braking, or a significant age spread within the regions. The rotational velocities in both regions show a clear mass dependence, with F-K stars rotating on average about twice as fast as M stars, consistent with results reported for other clusters of similar age. Similarly, we find the upper envelope of the observed values of specific angular momentum j varies as M 0.5 for our sample which spans a mass range of ∼0.16-3 M sun . This power law complements previous studies in Orion which estimated j ∝ M 0.25 for ∼ sun . Furthermore, the overall specific angular momentum of this ∼10 Myr population is five times lower than that of non-accretors in our sample, and implies a stellar braking mechanism other than disk braking could be at work. For a subsample of 67 objects with mid-infrared photometry, we examine the connection between accretion signatures and dusty disks: in the vast majority of cases (63/67), the two properties correlate well, which suggests that the timescale of gas accretion is similar to the lifetime of inner disks.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

Science.gov (United States)

Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

2015-10-01

This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

Directory of Open Access Journals (Sweden)

Luo Jun

2015-10-01

Full Text Available This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

On Averaging Rotations

DEFF Research Database (Denmark)

Gramkow, Claus

1999-01-01

In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belo...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion......In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

Accretion-induced luminosity spreads in young clusters: evidence from stellar rotation

Science.gov (United States)

Littlefair, S. P.; Naylor, Tim; Mayne, N. J.; Saunders, Eric; Jeffries, R. D.

2011-05-01

We present an analysis of the rotation of young stars in the associations Cepheus OB3b, NGC 2264, 2362 and the Orion Nebula Cluster (ONC). We discover a correlation between rotation rate and position in a colour-magnitude diagram (CMD) such that stars which lie above an empirically determined median pre-main sequence rotate more rapidly than stars which lie below this sequence. The same correlation is seen, with a high degree of statistical significance, in each association studied here. If position within the CMD is interpreted as being due to genuine age spreads within a cluster, then the stars above the median pre-main sequence would be the youngest stars. This would in turn imply that the most rapidly rotating stars in an association are the youngest, and hence those with the largest moments of inertia and highest likelihood of ongoing accretion. Such a result does not fit naturally into the existing picture of angular momentum evolution in young stars, where the stars are braked effectively by their accretion discs until the disc disperses. Instead, we argue that, for a given association of young stars, position within the CMD is not primarily a function of age, but of accretion history. We show that this hypothesis could explain the correlation we observe between rotation rate and position within the CMD.

Prognostic Factors Affecting Rotator Cuff Healing After Arthroscopic Repair in Small to Medium-sized Tears.

Science.gov (United States)

Park, Ji Soon; Park, Hyung Jun; Kim, Sae Hoon; Oh, Joo Han

2015-10-01

Small and medium-sized rotator cuff tears usually have good clinical and anatomic outcomes. However, healing failure still occurs in some cases. To evaluate prognostic factors for rotator cuff healing in patients with only small to medium-sized rotator cuff tears. Case-control study; Level of evidence, 3. Data were prospectively collected from 339 patients with small to medium-sized rotator cuff tears who underwent arthroscopic repair by a single surgeon between March 2004 and August 2012 and who underwent magnetic resonance imaging or computed tomographic arthrography at least 1 year after surgery. The mean age of the patients was 59.8 years (range, 39-80 years), and the mean follow-up time was 20.8 months (range, 12-66 months). The functional evaluation included the visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons score, Constant-Murley score, and Simple Shoulder Test. Postoperative VAS for pain and functional scores improved significantly compared with preoperative values (P rotator cuff healing (P 2 cm in size (34.2%) compared with patients with a tear ≤2 cm (10.6%) (P rotator cuff tears, grade II fatty degeneration of the infraspinatus muscle according to the Goutallier classification could be a reference point for successful healing, and anatomic outcomes might be better if repair is performed before the patient is 69 years old and the tear size exceeds 2 cm. © 2015 The Author(s).

Functional evaluation of patient after arthroscopic repair of rotator cuff tear.

Science.gov (United States)

Kumar, Rohit; Jadhav, Umesh

2014-06-01

Rotator cuff tear is a common problem either after trauma or after degenerative tear in old age group. Arthroscopic repair is the current concept of rotator cuff repair. Here, we are trying to evaluate the functional outcome after arthroscopic repair of full thickness rotator cuff tear (single row) in Indian population. Twenty five patients (14 males and 11 females) who underwent arthroscopic repair of full thickness rotator cuff tear at a single institution were included in the study. Postoperatively patient's shoulder was rated according to UCLA score, pain was graded according to the visual analog score. The range of motion was analysed and documented. The mean age of the patients were 50.48 years. The preoperative VAS score mode was 7 and post operative VAS was 1 (p value fair in 12% (n = 3), excellent in 8% (n = 2) and poor results were seen in none of the patients. The mean UCLA improved from a score of 15.84 to 30.28 with a p value advantages, hence we used a single row repair considering the Indian population and the cost effectiveness of the surgery with good to excellent results.

Association Between Rotating Night Shift Work and Risk of Coronary Heart Disease Among Women.

Science.gov (United States)

Vetter, Céline; Devore, Elizabeth E; Wegrzyn, Lani R; Massa, Jennifer; Speizer, Frank E; Kawachi, Ichiro; Rosner, Bernard; Stampfer, Meir J; Schernhammer, Eva S

2016-04-26

Prospective studies linking shift work to coronary heart disease (CHD) have been inconsistent and limited by short follow-up. To determine whether rotating night shift work is associated with CHD risk. Prospective cohort study of 189,158 initially healthy women followed up over 24 years in the Nurses' Health Studies (NHS [1988-2012]: N = 73,623 and NHS2 [1989-2013]: N = 115,535). Lifetime history of rotating night shift work (≥3 night shifts per month in addition to day and evening shifts) at baseline (updated every 2 to 4 years in the NHS2). Incident CHD; ie, nonfatal myocardial infarction, CHD death, angiogram-confirmed angina pectoris, coronary artery bypass graft surgery, stents, and angioplasty. During follow-up, 7303 incident CHD cases occurred in the NHS (mean age at baseline, 54.5 years) and 3519 in the NHS2 (mean age, 34.8 years). In multivariable-adjusted Cox proportional hazards models, increasing years of baseline rotating night shift work was associated with significantly higher CHD risk in both cohorts. In the NHS, the association between duration of shift work and CHD was stronger in the first half of follow-up than in the second half (P=.02 for interaction), suggesting waning risk after cessation of shift work. Longer time since quitting shift work was associated with decreased CHD risk among ever shift workers in the NHS2 (Pwomen who worked as registered nurses, longer duration of rotating night shift work was associated with a statistically significant but small absolute increase in CHD risk. Further research is needed to explore whether the association is related to specific work hours and individual characteristics.

Asteroseismic measurement of surface-to-core rotation in a main-sequence star*

Directory of Open Access Journals (Sweden)

Kurtz Donald W.

2015-01-01

Full Text Available We have discovered rotationally split core g-mode triplets and surface p-mode triplets and quintuplets in a terminal age main-sequence A star, KIC 11145123, that shows both δ Sct p-mode pulsations and γ Dor g-mode pulsations. This gives the first robust determination of the rotation of the deep core and surface of a main-sequence star, essentially model-independently. We find its rotation to be nearly uniform with a period near 100 d, but we show with high confidence that the surface rotates slightly faster than the core. A strong angular momentum transfer mechanism must be operating to produce the nearly rigid rotation, and a mechanism other than viscosity must be operating to produce a more rapidly rotating surface than core. Our asteroseismic result, along with previous asteroseismic constraints on internal rotation in some B stars, and measurements of internal rotation in some subgiant, giant and white dwarf stars, has made angular momentum transport in stars throughout their lifetimes an observational science.

Physician training rotations in a large urban health department.

Science.gov (United States)

Alkon, Ellen; Kim-Farley, Robert; Gunzenhauser, Jeffrey

2014-01-01

Hospitals are the normal setting for physician residency training within the United States. When a hospital cannot provide the specific training needed, a special rotation for that experience is arranged. Linkages between clinical and public health systems are vital to achieving improvements in overall health status in the United States. Nevertheless, most physicians in postgraduate residency programs receive neither training nor practical experience in the practice of public health. For many years, public health rotations have been available within the Los Angeles County Department of Public Health (and its antecedent organizations). Arrangements that existed with local medical schools for residents to rotate with Los Angeles County Department of Health hospitals were extended to include a public health rotation. A general model for the rotation ensured that each resident received education and training relevant to the clinician in practice. Some parts of the model for experience have changed over time while others have not. Also, the challenges and opportunities for both trainees and preceptors have evolved and varied over time. A logic model demonstrates the components and changes with the public health rotation. Changes included alterations in recruitment, expectations, evaluation, formal education, and concepts related to the experience. Changes in the rotation model occurred in the context of other major environmental changes such as new electronic technology, changing expectations for residents, and evolving health services and public health systems. Each impacted the public health rotation. The evaluation method developed included content tests, assessment of competencies by residents and preceptors, and satisfaction measures. Results from the evaluation showed increases in competency and a high level of satisfaction after a public health rotation. The article includes examples of challenges and benefits to a local health department in providing a public

Speed of recovery after arthroscopic rotator cuff repair.

Science.gov (United States)

Kurowicki, Jennifer; Berglund, Derek D; Momoh, Enesi; Disla, Shanell; Horn, Brandon; Giveans, M Russell; Levy, Jonathan C

2017-07-01

The purpose of this study was to delineate the time taken to achieve maximum improvement (plateau of recovery) and the degree of recovery observed at various time points (speed of recovery) for pain and function after arthroscopic rotator cuff repair. An institutional shoulder surgery registry query identified 627 patients who underwent arthroscopic rotator cuff repair between 2006 and 2015. Measured range of motion, patient satisfaction, and patient-reported outcome measures were analyzed for preoperative, 3-month, 6-month, 1-year, and 2-year intervals. Subgroup analysis was performed on the basis of tear size by retraction grade and number of anchors used. As an entire group, the plateau of maximum recovery for pain, function, and motion occurred at 1 year. Satisfaction with surgery was >96% at all time points. At 3 months, 74% of improvement in pain and 45% to 58% of functional improvement were realized. However, only 22% of elevation improvement was achieved (P rotation. Smaller tears had higher motion and functional scores across all time points. Tear size did not influence pain levels. The plateau of maximum recovery after rotator cuff repair occurred at 1 year with high satisfaction rates at all time points. At 3 months, approximately 75% of pain relief and 50% of functional recovery can be expected. Larger tears have a slower speed of recovery. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Partial repair in irreparable rotator cuff tear: our experience in long-term follow-up.

Science.gov (United States)

Di Benedetto, E D; Di Benedetto, Paolo; Fiocchi, Andrea; Beltrame, Alessandro; Causero, Araldo

2017-10-18

Massive rotator cuff tears are a common source of shoulder pain and dysfunction, especially in middle age patient; these lesions represent about 20% of all rotator cuff tears and 80% of recurrent tears. Some lesions are not repairable or should not be repaired: in this case, a rotator cuff partial repair should be recommended. The aim of the study is to evaluate the outcome of rotator cuff partial repair in irreparable rotator cuff massive tear at medium and long-term follow-up. We have evaluated 74 consecutive patients treated with functional repair of rotator cuff by the same surgeon between 2006 and 2014. We divided patients into 2 groups, obtaining 2 average follow-up: at about 6,5 (group A) and 3 years (group B). In December 2015, we evaluated in every patient ROM and Constant Score. We analyzed difference between pre-operatory data and the 2 groups.  Results: We found statistical significant difference in ROM and in Constant Score between pre-operatory data and group A and group B. Between group A and group B there is relevant difference in Constant Score but not in ROM. Partial repair can give good results in a medium follow-up, in terms of pain relief and improvement of ROM, as well as in quality of life. Difference in ROM and Constant Score between group A and group B may indicate the begin of partial repair failure; according to our data, 6-7 years may be the time limit for this surgery technique.

Lithium depletion and rotation in main-sequence stars

International Nuclear Information System (INIS)

Balachandran, S.

1990-01-01

Lithium abundances were measured in nearly 200 old disk-population F stars to examine the effects of rotational braking on the depletion of Li. The sample was selected to be slightly evolved off the main sequence so that the stars have completed all the Li depletion they will undergo on the main sequence. A large scatter in Li abundances in the late F stars is found, indicating that the Li depletion is not related to age and spectral type alone. Conventional depletion mechanisms like convective overshoot and microscopic diffusion are unable to explain Li depletion in F stars with thin convective envelopes and are doubly taxed to explain such a scatter. No correlation is found between Li abundance and the present projected rotational velocity and some of the most rapid rotators are undepleted, ruling out meridional circulation as the cause of Li depletion. There is a somewhat larger spread in Li abundances in the spun-down late F stars compared to the early F stars which should remain rotationally unaltered on the main sequence. 85 refs

The roles of chronological age and time perspective in memory positivity.

Science.gov (United States)

Kan, Irene P; Garrison, Shaina L; Drummey, Anna B; Emmert, Brian E; Rogers, Leeland L

2018-07-01

The observation that older adults show enhanced cognition for emotionally positive information has been labeled the positivity effect (Reed, Chan, & Mikels, 2014). According to the Socioemotional Selectivity Theory (SST, Carstensen, 1991), a prominent lifespan development theory, cognition is strongly influenced by motivational goals, and these goals are impacted by subjective time perspective. Although the positivity effect is most commonly observed in older adults, as age usually co-varies with time perspective, the SST posits that time perspective, not age, is the key explanatory factor of positivity. We examined the effects of these predictors on positivity in an episodic memory task in younger and older adults and found that age, not time perspective, was a key predictor of memory positivity. Our results add to the growing literature that challenge the notion that time perspective is the driving force behind age-related differences in emotional processing and functioning.

Quark Deconfinement in Rotating Neutron Stars

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Richard D. Mellinger

2017-01-01

Full Text Available In this paper, we use a three flavor non-local Nambu–Jona-Lasinio (NJL model, an improved effective model of Quantum Chromodynamics (QCD at low energies, to investigate the existence of deconfined quarks in the cores of neutron stars. Particular emphasis is put on the possible existence of quark matter in the cores of rotating neutron stars (pulsars. In contrast to non-rotating neutron stars, whose particle compositions do not change with time (are frozen in, the type and structure of the matter in the cores of rotating neutron stars depends on the spin frequencies of these stars, which opens up a possible new window on the nature of matter deep in the cores of neutron stars. Our study shows that, depending on mass and rotational frequency, up to around 8% of the mass of a massive neutron star may be in the mixed quark-hadron phase, if the phase transition is treated as a Gibbs transition. We also find that the gravitational mass at which quark deconfinement occurs in rotating neutron stars varies quadratically with spin frequency, which can be fitted by a simple formula.

Physics of Rotating and Expanding Black Hole Universe

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Seshavatharam U. V. S.

2010-04-01

Full Text Available Throughout its journey universe follows strong gravity. By unifying general theory of relativity and quantum mechanics a simple derivation is given for rotating black hole's temperature. It is shown that when the rotation speed approaches light speed temperature approaches Hawking's black hole temperature. Applying this idea to the cosmic black hole it is noticed that there is "no cosmic temperature" if there is "no cosmic rotation". Starting from the Planck scale it is assumed that universe is a rotating and expanding black hole. Another key assumption is that at any time cosmic black hole rotates with light speed. For this cosmic sphere as a whole while in light speed rotation "rate of decrease" in temperature or "rate of increase" in cosmic red shift is a measure of "rate of cosmic expansion". Since 1992, measured CMBR data indicates that, present CMB is same in all directions equal to $2.726^circ$ K, smooth to 1 part in 100,000 and there is no continuous decrease! This directly indicates that, at present rate of decrease in temperature is practically zero and rate of expansion is practically zero. Universe is isotropic and hence static and is rotating as a rigid sphere with light speed. At present galaxies are revolving with speeds proportional to their distances from the cosmic axis of rotation. If present CMBR temperature is $2.726^circ$ K, present value of obtained angular velocity is $2.17 imes 10^{-18}$ rad/sec $cong$ 67 Km/sec$imes$Mpc. Present cosmic mass density and cosmic time are fitted with a $ln (volume ratio$ parameter. Finally it can be suggested that dark matter and dark energy are ad-hoc and misleading concepts.

Nonlinearity in the rotational dynamics of Haidinger's brushes

Science.gov (United States)

Rothmayer, Mark; Dultz, Wolfgang; Frins, Erna; Zhan, Qiwen; Tierney, Dennis; Schmitzer, Heidrun

2007-10-01

Haidinger's brushes are an entoptic effect of the human visual system that enables us to detect polarized light. However, individual perceptions of Haidinger's brushes can vary significantly. We find that the birefringence of the cornea influences the rotational motion and the contrast of Haidinger's brushes and may offer an explanation for individual differences. We have devised an experimental setup to simulate various phase shifts of the cornea and found a switching effect in the rotational dynamics of Haidinger's brushes. In addition, age related macular degeneration reduces the polarization effect of the macula and thus also leads to changes in the brush pattern.

Pleiades rapid rotators - evidence for an evolutionary sequence

International Nuclear Information System (INIS)

Butler, R.P.; Marcy, G.W.; Cohen, R.D.; Duncan, D.K.; California Univ., La Jolla; Space Telescope Science Institute, Baltimore, MD)

1987-01-01

Four rapidly rotating early-K dwarfs in the Pleiades are shown to contain an order of magnitude more Li than four slow rotators of the same spectral type, as would be expected if they were systematically younger. This supports the idea that late-type stars first arrive on the main sequence with V(rot) greater than about 100 km/s, that they spin down to V(rot) less than about 10 km/s in 10 to the 7th to 10 to the 8th yr, and that the Pleiades lower main sequence shows such an age spread. 14 references

Time Perspective and Emotion Regulation as Predictors of Age-Related Subjective Passage of Time.

Science.gov (United States)

Wittmann, Marc; Rudolph, Tina; Linares Gutierrez, Damisela; Winkler, Isabell

2015-12-17

Hardly any empirical work exists concerning the relationship between the intra-individually stable time perspective relating to the past, present, and future and the subjective speed of time passing in everyday life. Moreover, studies consistently show that the subjective passage of time over the period of the last ten years speeds up as we get older. Modulating variables influencing this phenomenon are still unknown. To investigate these two unresolved issues, we conducted an online survey with n = 423 participants ranging in age between 17 and 81 assessing trait time perspective of the past, present, and future, and relating these subscales with a battery of measures pertaining to the subjective passage of time. Moreover, the subjective passage of time as an age-dependent variable was probed in relationship to emotion awareness, appraisal and regulation. Results show how present hedonism is linked with having fewer routines in life and a faster passage of the last week; the past negative perspective is related to time pressure, time expansion and more routine; a pronounced future perspective is related to a general faster passage of time. Importantly, increased emotion regulation and a balanced time perspective are related to a slower passage of the last ten years. These novel findings are discussed within models of time perception and the time perspective.

Verifying the gravitational shift due to the earth's rotation

International Nuclear Information System (INIS)

Briatore, L.; Leschiutta, S.

1976-01-01

Data on various independent time scales kept in different laboratories are elaborated in order to verify the gravitational shift due to the earth's rotation. It is shown that the state of the art in the measurement of time is just now resulting in the possibility to make measurement of Δ t/t approximately 10 -13 . Moreover it is shown an experimental evidence of the earth's rotation relativistic effects

ROTATIONAL VELOCITIES FOR M DWARFS

International Nuclear Information System (INIS)

Jenkins, J. S.; Ramsey, L. W.; Jones, H. R. A.; Pavlenko, Y.; Barnes, J. R.; Pinfield, D. J.; Gallardo, J.

2009-01-01

We present spectroscopic rotation velocities (v sin i) for 56 M dwarf stars using high-resolution Hobby-Eberly Telescope High Resolution Spectrograph red spectroscopy. In addition, we have also determined photometric effective temperatures, masses, and metallicities ([Fe/H]) for some stars observed here and in the literature where we could acquire accurate parallax measurements and relevant photometry. We have increased the number of known v sin i values for mid M stars by around 80% and can confirm a weakly increasing rotation velocity with decreasing effective temperature. Our sample of v sin is peak at low velocities (∼3 km s -1 ). We find a change in the rotational velocity distribution between early M and late M stars, which is likely due to the changing field topology between partially and fully convective stars. There is also a possible further change in the rotational distribution toward the late M dwarfs where dust begins to play a role in the stellar atmospheres. We also link v sin i to age and show how it can be used to provide mid-M star age limits. When all literature velocities for M dwarfs are added to our sample, there are 198 with v sin i ≤ 10 km s -1 and 124 in the mid-to-late M star regime (M3.0-M9.5) where measuring precision optical radial velocities is difficult. In addition, we also search the spectra for any significant Hα emission or absorption. Forty three percent were found to exhibit such emission and could represent young, active objects with high levels of radial-velocity noise. We acquired two epochs of spectra for the star GJ1253 spread by almost one month and the Hα profile changed from showing no clear signs of emission, to exhibiting a clear emission peak. Four stars in our sample appear to be low-mass binaries (GJ1080, GJ3129, Gl802, and LHS3080), with both GJ3129 and Gl802 exhibiting double Hα emission features. The tables presented here will aid any future M star planet search target selection to extract stars with low v

Prospects of real-time ion temperature and rotation profiles based on neural-network charge exchange analysis

Energy Technology Data Exchange (ETDEWEB)

Koenig, R W.T.; Von Hellermann, M [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Svensson, J [Royal Inst. of Tech., Stockholm (Sweden)

1994-07-01

A back-propagation neural network technique is used at JET to extract plasma parameters like ion temperature, rotation velocities or spectral line intensities from charge exchange (CX) spectra. It is shown that in the case of the C VI CX spectra, neural networks can give a good estimation (better than +-20% accuracy) for the main plasma parameters (Ti, V{sub rot}). Since the neural network approach involves no iterations or initial guesses the speed with which a spectrum is processed is so high (0.2 ms/spectrum) that real time analysis will be achieved in the near future. 4 refs., 8 figs.

Prospects of real-time ion temperature and rotation profiles based on neural-network charge exchange analysis

International Nuclear Information System (INIS)

Koenig, R.W.T.; Von Hellermann, M.

1994-01-01

A back-propagation neural network technique is used at JET to extract plasma parameters like ion temperature, rotation velocities or spectral line intensities from charge exchange (CX) spectra. It is shown that in the case of the C VI CX spectra, neural networks can give a good estimation (better than +-20% accuracy) for the main plasma parameters (Ti, V rot ). Since the neural network approach involves no iterations or initial guesses the speed with which a spectrum is processed is so high (0.2 ms/spectrum) that real time analysis will be achieved in the near future. 4 refs., 8 figs

Performance of intact and castrated beef cattle in an intensive croppasture rotation system

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Tercilio Turini

2015-07-01

Full Text Available This research had as objective to evaluate the performance of intact or castrated beef cattle in a croppasture rotation system. The experiment was conducted during 2004 and 2005, and carried out at the Cooperativa Agropecuária Mourãoense (COAMO Experimental Farm, in Campo Mourão city, Paraná state. It was used a completely randomized design, with two treatments, intact or castrated. Forty ½Angus+½Nelore crossbred animals, with average age of nine months, were used. Half of the animals were castrated at weaning, and the other half was kept intact. Pasture was composed of two areas. The winter field, established after soybean crop, was composed by a mixture of black oat (Avena strigosa and Italian ryegrass (Lolium multiforum. The summer field was composed by stargrass (Cynodon nlemfuensis and Mombaça grass (Panicum maximum. During the winter time it was used a continues grazing system, with regulator animals (put and take, and during the summer an intensive rotational system, with regulator animals and fixed grazing period. Intact animals presented higher average daily weight gain (0.907 vs 0.698 kg, slaughter weight (490.9 vs 442.2 kg, and hot carcass weight (250.2 vs 232.6 kg. Slaughter age was influenced by sexual condition, being lesser in the intact animals. Carcass dressing percentage was similar for the groups. Castrated animals showed better finishing fat cover and backfat thickness (3.45 vs 2.70 mm compared to intact ones. Therefore, it can be concluded that intact animals presents better performance than castrated ones when finished in an intensive crop-pasture rotation system, however, they may not present the minimum required fat cover, when slaughter at young ages.

The β Pictoris association low-mass members: Membership assessment, rotation period distribution, and dependence on multiplicity

Science.gov (United States)

Messina, S.; Lanzafame, A. C.; Malo, L.; Desidera, S.; Buccino, A.; Zhang, L.; Artemenko, S.; Millward, M.; Hambsch, F.-J.

2017-10-01

Context. Low-mass members of young loose stellar associations and open clusters exhibit a wide spread of rotation periods. Such a spread originates from the distributions of masses and initial rotation periods. However, multiplicity can also play a significant role. Aims: We aim to investigate the role played by physical companions in multiple systems in shortening the primordial disk lifetime, anticipating the rotation spin up with respect to single stars. Methods: We have compiled the most extensive list to date of low-mass bona fide and candidate members of the young 25-Myr β Pictoris association. We have measured from our own photometric time series or from archival time series the rotation periods of almost all members. In a few cases the rotation periods were retrieved from the literature. We used updated UVWXYZ components to assess the membership of the whole stellar sample. Thanks to the known basic properties of most members we built the rotation period distribution distinguishing between bona fide members and candidate members and according to their multiplicity status. Results: We find that single stars and components of multiple systems in wide orbits (>80 AU) have rotation periods that exhibit a well defined sequence arising from mass distribution with some level of spread likely arising from initial rotation period distribution. All components of multiple systems in close orbits (Pleiades shows that whereas the evolution of F-G stars is well reproduced by angular momentum evolution models, this is not the case for the slow K and early-M stars. Finally, we find that the amplitude of their light curves is correlated neither with rotation nor with mass. Conclusions: Once single stars and wide components of multiple systems are separated from close components of multiple systems, the rotation period distributions exhibit a well defined dependence on mass that allows us to make a meaningful comparison with similar distributions of either younger or older

Ultra high energy electrons powered by pulsar rotation.

Science.gov (United States)

Mahajan, Swadesh; Machabeli, George; Osmanov, Zaza; Chkheidze, Nino

2013-01-01

A new mechanism of particle acceleration, driven by the rotational slow down of the Crab pulsar, is explored. The rotation, through the time dependent centrifugal force, can efficiently excite unstable Langmuir waves in the electron-positron (hereafter e(±)) plasma of the star magnetosphere. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV (~ 100 TeV) and even PeV energy domain. It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

Asteroid rotation rates

International Nuclear Information System (INIS)

Binzel, R.P.; Farinella, P.

1989-01-01

Within the last decade the data base of asteroid rotation parameters (rotation rates and lightcurve amplitudes) has become sufficiently large to identify some definite rends and properties which can help us to interpret asteroid collisional evolution. Many significant correlations are found between rotation parameters and diameter, with distinct changes occurring near 125 km. The size range, which is also the diameter above which self-gravity may become important, perhaps represents a division between surviving primordial asteroids and collisional fragments. A Maxwellian is able to fit the observed rotation rate distributions of asteroids with D>125 km, implying that their rotation rates may be determined by collisional evolution. Asteroids with D<125 km show an excess of slow rotators and their non-Maxwellian distributions suggests that their rotation rates are more strongly influenced by other processes, such as the distribution resulting from their formation in catastrophic disruption events. Other correlations observed in the data set include different mean rotation rates for C, S and M type asteroids implying that their surface spectra are indicative of bulk properties

Evaluation of Repair Tension in Arthroscopic Rotator Cuff Repair: Does It Really Matter to the Integrity of the Rotator Cuff?

Science.gov (United States)

Kim, Do Hoon; Jang, Young Hoon; Choi, Young Eun; Lee, Hwa-Ryeong; Kim, Sae Hoon

2016-11-01

Repair tension of a torn rotator cuff can affect healing after repair. However, a measurement of the actual tension during arthroscopic rotator cuff repair is not feasible. The relationship between repair tension and healing of a rotator cuff repair remains unclear. The purpose of this study was to evaluate the effect of repair tension on healing at the repair site. The hypothesis was that repair tension would be a major factor in determining the anatomic outcome of rotator cuff repair. Cohort study; Level of evidence, 2. Arthroscopic rotator cuff repairs (132 patients) for full-thickness rotator cuff tears were analyzed. An intraoperative model was designed for the estimation of repair tension using a tensiometer. Magnetic resonance imaging (MRI) was performed approximately 1 year (mean [±SD], 12.7 ± 3.2 months) postoperatively for the evaluation of healing at the repair site. Multivariable analysis was performed for tear size, amount of retraction, and fatty degeneration (FD) of rotator cuff muscles. The mean repair tension measured during the arthroscopic procedure was 28.5 ± 23.1 N. There was a statistically significant correlation between tension and tear size (Pearson correlation coefficient [PCC], 0.529; P repair tension also showed a significant inverse correlation with healing at the repair site (SCC, 0.195; P = .025). However, when sex, age, tear size, amount of retraction, tendon quality, and FD of rotator cuff muscles were included for multivariable logistic regression analysis, only FD of the infraspinatus showed an association with the anatomic outcome of repair (Exp(B) = 0.596; P = .010). Our intraoperative model for the estimation of rotator cuff repair tension showed an inverse correlation of repair tension with healing at the repair site, suggesting that complete healing is less likely with high-tension repairs. A significant association was observed on MRI between a high level of FD of the infraspinatus and repaired tendon integrity. © 2016

On Averaging Rotations

DEFF Research Database (Denmark)

Gramkow, Claus

2001-01-01

In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong ...... approximations to the Riemannian metric, and that the subsequent corrections are inherent in the least squares estimation.......In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

COMPARISON OF ASTYM THERAPY AND KINESIOTAPING FOR ROTATOR CUFF TENDINOPATHY IN DIABETIC PATIENTS: RANDOMIZED CONTROLLED TRIAL

Directory of Open Access Journals (Sweden)

Azza Atya

2017-09-01

Full Text Available Background: Rotator cuff tendinopathy is a significant problem among diabetics that frequently restricts patient’s activity in terms of pain and disability. The purpose of this study was to compare between the effect of Astym therapy and kinesiotaping in treating diabetic patients with chronic rotator cuff tendinopathy. Methods: 56 diabetic patients diagnosed with chronic rotator cuff tendinopathy were randomly assigned into Astym therapy group (n=28 or kinesiotaping group (n= 28. All patients received conventional program in addition to Astym treatment or Kinesiotaping for 24 sessions (2times/week. Patients were assessed at baseline and at the end of corresponding intervention with visual analogy scale (VAS for pain intensity, shoulder disability questioner (SDQ for shoulder disability, and electrogoniometer for shoulder range of motion. Results: For the 56 study participants (21 males and 35 females; mean age=41.9±6.9 years there were significant differences in all measuring outcomes in both group when compared to baseline measurements (p 0.05. Conclusion: kinesiotaping appears to be more effective than Astym therapy in reducing pain for diabetic patients with chronic rotator cuff tendinopathy.

Quantum measurement of a rapidly rotating spin qubit in diamond.

Science.gov (United States)

Wood, Alexander A; Lilette, Emmanuel; Fein, Yaakov Y; Tomek, Nikolas; McGuinness, Liam P; Hollenberg, Lloyd C L; Scholten, Robert E; Martin, Andy M

2018-05-01

A controlled qubit in a rotating frame opens new opportunities to probe fundamental quantum physics, such as geometric phases in physically rotating frames, and can potentially enhance detection of magnetic fields. Realizing a single qubit that can be measured and controlled during physical rotation is experimentally challenging. We demonstrate quantum control of a single nitrogen-vacancy (NV) center within a diamond rotated at 200,000 rpm, a rotational period comparable to the NV spin coherence time T 2 . We stroboscopically image individual NV centers that execute rapid circular motion in addition to rotation and demonstrate preparation, control, and readout of the qubit quantum state with lasers and microwaves. Using spin-echo interferometry of the rotating qubit, we are able to detect modulation of the NV Zeeman shift arising from the rotating NV axis and an external DC magnetic field. Our work establishes single NV qubits in diamond as quantum sensors in the physically rotating frame and paves the way for the realization of single-qubit diamond-based rotation sensors.

An active balance board system with real-time control of stiffness and time-delay to assess mechanisms of postural stability.

Science.gov (United States)

Cruise, Denise R; Chagdes, James R; Liddy, Joshua J; Rietdyk, Shirley; Haddad, Jeffrey M; Zelaznik, Howard N; Raman, Arvind

2017-07-26

Increased time-delay in the neuromuscular system caused by neurological disorders, concussions, or advancing age is an important factor contributing to balance loss (Chagdes et al., 2013, 2016a,b). We present the design and fabrication of an active balance board system that allows for a systematic study of stiffness and time-delay induced instabilities in standing posture. Although current commercial balance boards allow for variable stiffness, they do not allow for manipulation of time-delay. Having two controllable parameters can more accurately determine the cause of balance deficiencies, and allows us to induce instabilities even in healthy populations. An inverted pendulum model of human posture on such an active balance board predicts that reduced board rotational stiffness destabilizes upright posture through board tipping, and limit cycle oscillations about the upright position emerge as feedback time-delay is increased. We validate these two mechanisms of instability on the designed balance board, showing that rotational stiffness and board time-delay induced the predicted postural instabilities in healthy, young adults. Although current commercial balance boards utilize control of rotational stiffness, real-time control of both stiffness and time-delay on an active balance board is a novel and innovative manipulation to reveal balance deficiencies and potentially improve individualized balance training by targeting multiple dimensions contributing to standing balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physics of Rotating and Expanding Black Hole Universe

Directory of Open Access Journals (Sweden)

Seshavatharam U. V. S.

2010-04-01

Full Text Available Throughout its journey universe follows strong gravity. By unifying general theory of relativity and quantum mechanics a simple derivation is given for rotating black hole’s temperature. It is shown that when the rotation speed approaches light speed temperature approaches Hawking’s black hole temperature. Applying this idea to the cosmic black hole it is noticed that there is “no cosmic temperature” if there is “no cosmic rotation”. Starting from the Planck scale it is assumed that- universe is a rotating and expanding black hole. Another key assumption is that at any time cosmic black hole rotates with light speed. For this cosmic sphere as a whole while in light speed rotation “rate of decrease” in temperature or “rate of increase” in cosmic red shift is a measure of “rate of cosmic expansion”. Since 1992, measured CMBR data indicates that, present CMB is same in all directions equal to 2 : 726 K ; smooth to 1 part in 100,000 and there is no continuous decrease! This directly indicates that, at present rate of decrease in temperature is practically zero and rate of expansion is practically zero. Universe is isotropic and hence static and is rotating as a rigid sphere with light speed. At present galaxies are revolving with speeds proportional to their distances from the cosmic axis of rotation. If present CMBR temperature is 2 : 726 K, present value of obtained angular velocity is 2 : 17 10 Present cosmic mass density and cosmic time are fitted with a ln ( volume ratio parameter. Finally it can be suggested that dark matter and dark energy are ad-hoc and misleading concepts.

Factors affecting rotator cuff healing after arthroscopic repair: osteoporosis as one of the independent risk factors.

Science.gov (United States)

Chung, Seok Won; Oh, Joo Han; Gong, Hyun Sik; Kim, Joon Yub; Kim, Sae Hoon

2011-10-01

The prognostic factors associated with structural outcome after arthroscopic rotator cuff repair have not yet been fully determined. The hypothesis of this study was that bone mineral density (BMD) is an important prognostic factor affecting rotator cuff healing after arthroscopic cuff repair. Cohort study; Level of evidence, 3. Among 408 patients who underwent arthroscopic repair for full-thickness rotator cuff tear between January 2004 and July 2008, 272 patients were included whose postoperative cuff integrity was verified by computed tomography arthrography (CTA) or ultrasonography (USG) and simultaneously who were evaluated by various functional outcome instruments. The mean age at the time of operation was 59.5 ± 7.9 years. Postoperative CTA or USG was performed at a mean 13.0 ± 5.1 months after surgery, and the mean follow-up period was 37.2 ± 10.0 months (range, 24-65 months). The clinical, structural, and surgery-related factors affecting cuff integrity including BMD were analyzed using both univariate and multivariate analysis. Evaluation of postoperative cuff integrity was performed by musculoskeletal radiologists who were unaware of the present study. The failure rate of rotator cuff healing was 22.8% (62 of 272). The failure rate was significantly higher in patients with lower BMD (P cuff healing failure following arthroscopic rotator cuff repair. Bone mineral density, as well as FI of the infraspinatus and amount of retraction, was an independent determining factor affecting postoperative rotator cuff healing. Further studies with prospective, randomized, and controlled design are needed to confirm the relationship between BMD and postoperative rotator cuff healing.

A Rotating-Bears Optical Dipole Trap for Cold Aatoms

International Nuclear Information System (INIS)

Friedman, N.; Ozeri, R.; Khaykovich, L.; Davidson, N.

1999-01-01

In the last few years, several optical dipole traps for cold atoms were demonstrated and used to study cold atomic collisions, long atomic coherence times and quantum collective effects. Blue-detuned dipole traps, where repulsive light forces confines atoms mostly in dark, offer long storage, and photon-scattering times, combined with strong confinement forces. Unfortunately, such blue-detuned dipole traps involve complicated light intensity distributions that require either multiple laser beams or complicated phase elements. Here, we propose and demonstrate a novel configuration for a single-beam blue-detuned dipole trap, which enables larger trapping volume, and fast temporal changes in the trap size and shape. Our trap consists of a tightly-focused laser beam which is rapidly rotated (with rotation frequency up to 400 khz) with two orthogonal acousto optical scanners. For very high rotation frequencies the atoms feel a time-averaged static dipole potential. Therefore, when the radius of rotation is larger than the beam size, a dark volume which is completely surrounded by light is obtained around the focal region. By changing the rotation radius and the trapping laser intensity and detuning, the trap dimensions and oscillation frequency could be changed over a large parameter range. In particular trap diameters were changed between 50 to 220 microns and trap length was changed between 3.5 to 16 mm. ∼10 6 atoms were loaded into the rotating-beam dipole trap from a magneto optical trap. The density of the trapped atoms was 4x10 10 atoms/cm 3 ,their temperature was -6 pK. and the trap (1/e) lifetime was 0.65 sec, limited by collisions with background atoms. When the rotation frequency was decreased below the oscillation frequency of the atoms in the trap, the trap became unstable, and a sharp reduction of the trap lifetime was observed, in agreement with our theoretical analysis. Finally, we demonstrated adiabatic compression of atoms in the trap by decreasing

Fault Diagnosis of Rotating Machinery Based on Multisensor Information Fusion Using SVM and Time-Domain Features

Directory of Open Access Journals (Sweden)

Ling-li Jiang

2014-01-01

Full Text Available Multisensor information fusion, when applied to fault diagnosis, the time-space scope, and the quantity of information are expanded compared to what could be acquired by a single sensor, so the diagnostic object can be described more comprehensively. This paper presents a methodology of fault diagnosis in rotating machinery using multisensor information fusion that all the features are calculated using vibration data in time domain to constitute fusional vector and the support vector machine (SVM is used for classification. The effectiveness of the presented methodology is tested by three case studies: diagnostic of faulty gear, rolling bearing, and identification of rotor crack. For each case study, the sensibilities of the features are analyzed. The results indicate that the peak factor is the most sensitive feature in the twelve time-domain features for identifying gear defect, and the mean, amplitude square, root mean square, root amplitude, and standard deviation are all sensitive for identifying gear, rolling bearing, and rotor crack defect comparatively.

Feedback Control of Resistive Wall Modes in Slowly Rotating DIII-D Plasmas

Science.gov (United States)

Okabayashi, M.; Chance, M. S.; Takahashi, H.; Garofalo, A. M.; Reimerdes, H.; in, Y.; Chu, M. S.; Jackson, G. L.; La Haye, R. J.; Strait, E. J.

2006-10-01

In slowly rotating plasmas on DIII-D, the requirement of RWM control feedback have been identified, using a MHD code along with measured power supply characteristics. It was found that a small time delay is essential for achieving high beta if no rotation stabilization exists. The overall system delay or the band pass time constant should be in the range of 0.4 of the RWM growth time. Recently the control system was upgraded using twelve linear audio amplifiers and a faster digital control system, reducing the time-delay from 600 to 100 μs. The advantage has been clearly observed when the RWMs excited by ELMs were effectively controlled by feedback even if the rotation transiently slowed nearly to zero. This study provides insight on stability in the low- rotation plasmasw with balanced NBI in DIII-D and also in ITER.

RACE-OC Project: Rotation and variability in young stellar associations within 100 pc

OpenAIRE

Messina, S.; Desidera, S.; Turatto, M.; Lanzafame, A. C.; Guinan, E. F.

2010-01-01

Our goal is to determine the rotational and magnetic-related activity properties of stars at different stages of evolution. We have focussed our attention on 6 young loose stellar associations within 100 pc and ages in the range 8-70 Myr: TW Hydrae (~8 Myr), beta Pictoris (~10 Myr), Tucana/Horologium, Columba, Carina (~30 Myr), and AB Doradus (~70 Myr). Additional data on alpha Persei and the Pleiades from the literature is also considered. Rotational periods of stars showing rotational modul...

Quantitative rotating frame relaxometry methods in MRI.

Science.gov (United States)

Gilani, Irtiza Ali; Sepponen, Raimo

2016-06-01

Macromolecular degeneration and biochemical changes in tissue can be quantified using rotating frame relaxometry in MRI. It has been shown in several studies that the rotating frame longitudinal relaxation rate constant (R1ρ ) and the rotating frame transverse relaxation rate constant (R2ρ ) are sensitive biomarkers of phenomena at the cellular level. In this comprehensive review, existing MRI methods for probing the biophysical mechanisms that affect the rotating frame relaxation rates of the tissue (i.e. R1ρ and R2ρ ) are presented. Long acquisition times and high radiofrequency (RF) energy deposition into tissue during the process of spin-locking in rotating frame relaxometry are the major barriers to the establishment of these relaxation contrasts at high magnetic fields. Therefore, clinical applications of R1ρ and R2ρ MRI using on- or off-resonance RF excitation methods remain challenging. Accordingly, this review describes the theoretical and experimental approaches to the design of hard RF pulse cluster- and adiabatic RF pulse-based excitation schemes for accurate and precise measurements of R1ρ and R2ρ . The merits and drawbacks of different MRI acquisition strategies for quantitative relaxation rate measurement in the rotating frame regime are reviewed. In addition, this review summarizes current clinical applications of rotating frame MRI sequences. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Fano-Agarwal couplings and non-rotating wave approximation in single-photon timed Dicke subradiance

Science.gov (United States)

Mirza, Imran M.; Begzjav, Tuguldur

2016-04-01

Recently a new class of single-photon timed Dicke (TD) subradiant states has been introduced with possible applications in single-photon-based quantum information storage and on demand ultrafast retrieval (Scully M. O., Phys. Rev. Lett., 115 (2015) 243602). However, the influence of any kind of virtual processes on the decay of these new kind of subradiant states has been left as an open question. In the present paper, we focus on this problem in detail. In particular, we investigate how pure Fano-Agarwal couplings and other virtual processes arising from non-rotating wave approximation impact the decay of otherwise sub- and superradiant states. In addition to the overall virtual couplings among all TD states, we also focus on the dominant role played by the couplings between specific TD states.

Influence of toroidal rotation on resistive tearing modes in tokamaks

International Nuclear Information System (INIS)

Wang, S.; Ma, Z. W.

2015-01-01

Influence of toroidal equilibrium plasma rotation on m/n = 2/1 resistive tearing modes is studied numerically using a 3D toroidal MHD code (CLT). It is found that the toroidal rotation with or without shear can suppress the tearing instability and the Coriolis effect in the toroidal geometry plays a dominant role on the rotation induced stabilization. For a high viscosity plasma (τ R /τ V  ≫ 1, where τ R and τ V represent resistive and viscous diffusion time, respectively), the effect of the rotation shear combined with the viscosity appears to be stabilizing. For a low viscosity plasmas (τ R /τ V  ≪ 1), the rotation shear shows a destabilizing effect when the rotation is large

Shouldering the blame for impingement: the rotator cuff continuum

African Journals Online (AJOL)

postural abnormalities.5 SIS can be defined as compression of the rotator cuff and ... is often the cause, but an acromial bony spur may occur in older age groups .... Management. Conservative treatment is successful in most patients. Patients.

Rotator cuff exercises

Science.gov (United States)

... 25560729 . Read More Frozen shoulder Rotator cuff problems Rotator cuff repair Shoulder arthroscopy Shoulder CT scan Shoulder MRI scan Shoulder pain Patient Instructions Rotator cuff - self-care Shoulder surgery - discharge Using your ...

Gastrointestinal mean transit times in young and middle-aged healthy subjects

DEFF Research Database (Denmark)

Graff, J; Brinch, K; Madsen, Jan Lysgård

2001-01-01

To investigate the effects of age and gender on gastric, small intestinal and colonic mean transit times, a study was conducted in 32 healthy volunteers: eight young women (22-30 years), eight young men (20-28 years), eight middle-aged women (43-51 years) and eight middle-aged men (38-53 years......). After ingestion of a meal containing 111Indium-labelled water and 99mTechnetium-labelled omelette imaging of the abdomen was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric......, small intestinal and colonic mean transit times were calculated. The gastric, small intestinal and colonic mean transit times were significantly longer in women. Ageing was shown to accelerate the gastric and small intestinal transit significantly. In the group of men the colonic mean transit time...

Improper trunk rotation sequence is associated with increased maximal shoulder external rotation angle and shoulder joint force in high school baseball pitchers.

Science.gov (United States)

Oyama, Sakiko; Yu, Bing; Blackburn, J Troy; Padua, Darin A; Li, Li; Myers, Joseph B

2014-09-01

In a properly coordinated throwing motion, peak pelvic rotation velocity is reached before peak upper torso rotation velocity, so that angular momentum can be transferred effectively from the proximal (pelvis) to distal (upper torso) segment. However, the effects of trunk rotation sequence on pitching biomechanics and performance have not been investigated. The aim of this study was to investigate the effects of trunk rotation sequence on ball speed and on upper extremity biomechanics that are linked to injuries in high school baseball pitchers. The hypothesis was that pitchers with improper trunk rotation sequence would demonstrate lower ball velocity and greater stress to the joint. Descriptive laboratory study. Three-dimensional pitching kinematics data were captured from 72 high school pitchers. Subjects were considered to have proper or improper trunk rotation sequences when the peak pelvic rotation velocity was reached either before or after the peak upper torso rotation velocity beyond the margin of error (±3.7% of the time from stride-foot contact to ball release). Maximal shoulder external rotation angle, elbow extension angle at ball release, peak shoulder proximal force, shoulder internal rotation moment, and elbow varus moment were compared between groups using independent t tests (α ways that may influence injury risk. As such, exercises that reinforce the use of a proper trunk rotation sequence during the pitching motion may reduce the stress placed on the structures around the shoulder joint and lead to the prevention of injuries. © 2014 The Author(s).

Effect of aging time and aging temperature on fatigue and fracture behavior of 6063 aluminum alloy under seawater influence

International Nuclear Information System (INIS)

Siddiqui, R.A.; Abdul-Wahab, S.A.; Pervez, T.

2008-01-01

This paper describes experimentally the effect of seawater corrosion, aging time, and aging temperature on the fatigue resistance property of 6063 aluminum alloy. The 6063 aluminum alloy that was used for the study was heat treated and soaked in seawater for different intervals of time between 2 and 30 weeks. It was found that the maximum fatigue resistance property in the 6063 aluminum alloy was observed when aged between 7 and 9 h and heat treated at temperatures between 160 o C and 200 o C. Generally at constant load, the results indicated that the number of cycles to fail the 6063 aluminum alloy decreased with increasing the soaking time in seawater. Moreover, fracture surfaces were considered and studied under a scanning electron microscope (SEM). The results showed that the brittle fracture pattern tended to occur with the increase in aging time and temperature. The fatigue striations were observed very clearly at low and peak aging temperature. The increase in the fatigue resistance property with aging time was linked with the vacancies assisted diffusion mechanism and also by the hindering of dislocation movement by impure atoms

Time Perspective and Emotion Regulation as Predictors of Age-Related Subjective Passage of Time

Science.gov (United States)

Wittmann, Marc; Rudolph, Tina; Linares Gutierrez, Damisela; Winkler, Isabell

2015-01-01

Hardly any empirical work exists concerning the relationship between the intra-individually stable time perspective relating to the past, present, and future and the subjective speed of time passing in everyday life. Moreover, studies consistently show that the subjective passage of time over the period of the last ten years speeds up as we get older. Modulating variables influencing this phenomenon are still unknown. To investigate these two unresolved issues, we conducted an online survey with n = 423 participants ranging in age between 17 and 81 assessing trait time perspective of the past, present, and future, and relating these subscales with a battery of measures pertaining to the subjective passage of time. Moreover, the subjective passage of time as an age-dependent variable was probed in relationship to emotion awareness, appraisal and regulation. Results show how present hedonism is linked with having fewer routines in life and a faster passage of the last week; the past negative perspective is related to time pressure, time expansion and more routine; a pronounced future perspective is related to a general faster passage of time. Importantly, increased emotion regulation and a balanced time perspective are related to a slower passage of the last ten years. These novel findings are discussed within models of time perception and the time perspective. PMID:26694439

Time Perspective and Emotion Regulation as Predictors of Age-Related Subjective Passage of Time

Directory of Open Access Journals (Sweden)

Marc Wittmann

2015-12-01

Full Text Available Hardly any empirical work exists concerning the relationship between the intra-individually stable time perspective relating to the past, present, and future and the subjective speed of time passing in everyday life. Moreover, studies consistently show that the subjective passage of time over the period of the last ten years speeds up as we get older. Modulating variables influencing this phenomenon are still unknown. To investigate these two unresolved issues, we conducted an online survey with n = 423 participants ranging in age between 17 and 81 assessing trait time perspective of the past, present, and future, and relating these subscales with a battery of measures pertaining to the subjective passage of time. Moreover, the subjective passage of time as an age-dependent variable was probed in relationship to emotion awareness, appraisal and regulation. Results show how present hedonism is linked with having fewer routines in life and a faster passage of the last week; the past negative perspective is related to time pressure, time expansion and more routine; a pronounced future perspective is related to a general faster passage of time. Importantly, increased emotion regulation and a balanced time perspective are related to a slower passage of the last ten years. These novel findings are discussed within models of time perception and the time perspective.

Effect of rotating electric field on 3D complex (dusty) plasma

Science.gov (United States)

Wörner, L.; Nosenko, V.; Ivlev, A. V.; Zhdanov, S. K.; Thomas, H. M.; Morfill, G. E.; Kroll, M.; Schablinski, J.; Block, D.

2011-06-01

The effect of rotating electric field on 3D particle clusters suspended in rf plasma was studied experimentally. Spheroidal clusters were suspended inside a glass box mounted on the lower horizontal rf electrode, with gravity partially balanced by thermophoretic force. Clusters rotated in the horizontal plane, in response to rotating electric field that was created inside the box using conducting coating on its inner surfaces ("rotating wall" technique). Cluster rotation was always in the direction of applied field and had a shear in the vertical direction. The angular speed of rotation was 104-107 times lower than applied frequency. The experiment is compared to a recent theory.

Cosmic radiation and the Earth rotation

International Nuclear Information System (INIS)

Pil'nik, G.P.

1986-01-01

On the basis of classical astronomical observations of time, waves of nonuniformity in the Earth rotation were found. The wave with the period of 159sup(m).566 is very close to the period of global oscillations of the Sun surface 160sup(m).r-1 and to the period of the Germinga gamma-ray radiatnon 159sup(m).96. The necessity is pointed out of a detailed study of the Earth rotation in the days of great developments of astrophysical and geophysical research

Similarity estimators for irregular and age uncertain time series

Science.gov (United States)

Rehfeld, K.; Kurths, J.

2013-09-01

Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many datasets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age uncertain time series. We compare the Gaussian-kernel based cross correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

Similarity estimators for irregular and age-uncertain time series

Science.gov (United States)

Rehfeld, K.; Kurths, J.

2014-01-01

Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many data sets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age-uncertain time series. We compare the Gaussian-kernel-based cross-correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case, coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

Is rotator cuff repair worthwhile in patients with co-morbidities?

OpenAIRE

Yash Kishore Shah; Rohan Kiran Khavte; Parag Kishore Munshi

2015-01-01

Background: Rotator cuff tears are a common source of shoulder pain. The incidence increases with age and is most frequently due to degeneration of the tendon, rather than injury. This study is done to see whether in patients having established rotator cuff tears with co-morbidities like hypertension diabetes, epilepsy, etc. a surgical repair is worthwhile or whether it is better to leave such patients alone in order to give them a better quality of life. Methods: A total of 35 patients w...

Aging, Disablement, and Dying: Using Time-as-Process and Time-as-Resources Metrics to Chart Late-Life Change.

Science.gov (United States)

Ram, Nilam; Gerstorf, Denis; Fauth, Elizabeth; Zarit, Steven; Malmberg, Bo

2010-01-01

Time is a vehicle that can be used to represent aging-related processes and to index the amount of aging-related resources or burdens individuals have accumulated. Using data on cognitive (memory) performance from two Swedish studies of the elderly (OCTO and OCTO-TWIN), we illustrate how time-as-process and time-as-resources/burdens time metrics can be articulated and incorporated within a growth curve modeling framework. Our results highlight the possibilities for representing the contributions of primary, secondary, and tertiary aspects of aging to late-life changes in cognitive and other domains of functioning.

A numerical strategy for modelling rotating stall in core compressors

Science.gov (United States)

Vahdati, M.

2007-03-01

The paper will focus on one specific core-compressor instability, rotating stall, because of the pressing industrial need to improve current design methods. The determination of the blade response during rotating stall is a difficult problem for which there is no reliable procedure. During rotating stall, the blades encounter the stall cells and the excitation depends on the number, size, exact shape and rotational speed of these cells. The long-term aim is to minimize the forced response due to rotating stall excitation by avoiding potential matches between the vibration modes and the rotating stall pattern characteristics. Accurate numerical simulations of core-compressor rotating stall phenomena require the modelling of a large number of bladerows using grids containing several tens of millions of points. The time-accurate unsteady-flow computations may need to be run for several engine revolutions for rotating stall to get initiated and many more before it is fully developed. The difficulty in rotating stall initiation arises from a lack of representation of the triggering disturbances which are inherently present in aeroengines. Since the numerical model represents a symmetric assembly, the only random mechanism for rotating stall initiation is provided by numerical round-off errors. In this work, rotating stall is initiated by introducing a small amount of geometric mistuning to the rotor blades. Another major obstacle in modelling flows near stall is the specification of appropriate upstream and downstream boundary conditions. Obtaining reliable boundary conditions for such flows can be very difficult. In the present study, the low-pressure compression (LPC) domain is placed upstream of the core compressor. With such an approach, only far field atmospheric boundary conditions are specified which are obtained from aircraft speed and altitude. A chocked variable-area nozzle, placed after the last compressor bladerow in the model, is used to impose boundary

Energy transfer in scattering by rotating potentials

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Quantum mechanical scattering theory is studied for time-dependent. Schrödinger ... the energy transferred to a particle by collision with a rotating blade. Keywords. ..... terms of the unitary group for some time-independent generator. This will ...

Your Aging Eyes: How You See as Time Goes By

Science.gov (United States)

... Subscribe Special Issue: Seniors Print this issue Your Aging Eyes How You See as Time Goes By ... Building Social Bonds Coping with Caregiving Osteoporosis in Aging Wise Choices Protect Your Vision Have a comprehensive ...

Architectural and biochemical adaptations in skeletal muscle and bone following rotator cuff injury in a rat model.

Science.gov (United States)

Sato, Eugene J; Killian, Megan L; Choi, Anthony J; Lin, Evie; Choo, Alexander D; Rodriguez-Soto, Ana E; Lim, Chanteak T; Thomopoulos, Stavros; Galatz, Leesa M; Ward, Samuel R

2015-04-01

Injury to the rotator cuff can cause irreversible changes to the structure and function of the associated muscles and bones. The temporal progression and pathomechanisms associated with these adaptations are unclear. The purpose of this study was to investigate the time course of structural muscle and osseous changes in a rat model of a massive rotator cuff tear. Supraspinatus and infraspinatus muscle architecture and biochemistry and humeral and scapular morphological parameters were measured three days, eight weeks, and sixteen weeks after dual tenotomy with and without chemical paralysis via botulinum toxin A (BTX). Muscle mass and physiological cross-sectional area increased over time in the age-matched control animals, decreased over time in the tenotomy+BTX group, and remained nearly the same in the tenotomy-alone group. Tenotomy+BTX led to increased extracellular collagen in the muscle. Changes in scapular bone morphology were observed in both experimental groups, consistent with reductions in load transmission across the joint. These data suggest that tenotomy alone interferes with normal age-related muscle growth. The addition of chemical paralysis yielded profound structural changes to the muscle and bone, potentially leading to impaired muscle function, increased muscle stiffness, and decreased bone strength. Structural musculoskeletal changes occur after tendon injury, and these changes are severely exacerbated with the addition of neuromuscular compromise. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

CdS films deposited by chemical bath under rotation

International Nuclear Information System (INIS)

Oliva-Aviles, A.I.; Patino, R.; Oliva, A.I.

2010-01-01

Cadmium sulfide (CdS) films were deposited on rotating substrates by the chemical bath technique. The effects of the rotation speed on the morphological, optical, and structural properties of the films were discussed. A rotating substrate-holder was fabricated such that substrates can be taken out from the bath during the deposition. CdS films were deposited at different deposition times (10, 20, 30, 40 and 50 min) onto Corning glass substrates at different rotation velocities (150, 300, 450, and 600 rpm) during chemical deposition. The chemical bath was composed by CdCl 2 , KOH, NH 4 NO 3 and CS(NH 2 ) 2 as chemical reagents and heated at 75 deg. C. The results show no critical effects on the band gap energy and the surface roughness of the CdS films when the rotation speed changes. However, a linear increase on the deposition rate with the rotation energy was observed, meanwhile the stoichiometry was strongly affected by the rotation speed, resulting a better 1:1 Cd/S ratio as speed increases. Rotation effects may be of interest in industrial production of CdTe/CdS solar cells.

CdS films deposited by chemical bath under rotation

Energy Technology Data Exchange (ETDEWEB)

Oliva-Aviles, A.I., E-mail: aoliva@mda.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados Unidad Merida, Departamento de Fisica Aplicada. A.P. 73-Cordemex, 97310 Merida, Yucatan (Mexico); Patino, R.; Oliva, A.I. [Centro de Investigacion y de Estudios Avanzados Unidad Merida, Departamento de Fisica Aplicada. A.P. 73-Cordemex, 97310 Merida, Yucatan (Mexico)

2010-08-01

Cadmium sulfide (CdS) films were deposited on rotating substrates by the chemical bath technique. The effects of the rotation speed on the morphological, optical, and structural properties of the films were discussed. A rotating substrate-holder was fabricated such that substrates can be taken out from the bath during the deposition. CdS films were deposited at different deposition times (10, 20, 30, 40 and 50 min) onto Corning glass substrates at different rotation velocities (150, 300, 450, and 600 rpm) during chemical deposition. The chemical bath was composed by CdCl{sub 2}, KOH, NH{sub 4}NO{sub 3} and CS(NH{sub 2}){sub 2} as chemical reagents and heated at 75 deg. C. The results show no critical effects on the band gap energy and the surface roughness of the CdS films when the rotation speed changes. However, a linear increase on the deposition rate with the rotation energy was observed, meanwhile the stoichiometry was strongly affected by the rotation speed, resulting a better 1:1 Cd/S ratio as speed increases. Rotation effects may be of interest in industrial production of CdTe/CdS solar cells.

Tilt stability of rotating current rings with passive conductors

International Nuclear Information System (INIS)

Zweibel, E.G.; Pomphrey, N.

1984-12-01

We study the combined effects of rotation and resistive passive conductors on the stability of a rigid current in an external magnetic field. We present numerical and approximate analytical solutions to the equations of motion, which show that the ring is always tilt unstable on the resistive decay timescale of the conductors, although rotation and eddy currents may stabilize it over short times. Possible applications of our model include spheromaks which rotate or which are encircled by energetic particle rings

Influence of toroidal rotation on resistive tearing modes in tokamaks

Energy Technology Data Exchange (ETDEWEB)

Wang, S.; Ma, Z. W., E-mail: zwma@zju.edu.cn [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)

2015-12-15

Influence of toroidal equilibrium plasma rotation on m/n = 2/1 resistive tearing modes is studied numerically using a 3D toroidal MHD code (CLT). It is found that the toroidal rotation with or without shear can suppress the tearing instability and the Coriolis effect in the toroidal geometry plays a dominant role on the rotation induced stabilization. For a high viscosity plasma (τ{sub R}/τ{sub V} ≫ 1, where τ{sub R} and τ{sub V} represent resistive and viscous diffusion time, respectively), the effect of the rotation shear combined with the viscosity appears to be stabilizing. For a low viscosity plasmas (τ{sub R}/τ{sub V} ≪ 1), the rotation shear shows a destabilizing effect when the rotation is large.

Plasma rotation under a driven radial current in a tokamak

International Nuclear Information System (INIS)

Chang, C.S.

1999-01-01

The neoclassical behaviour of plasma rotation under a driven radial electrical current is studied in a tokamak geometry. An ambipolar radial electric field develops instantly in such a way that the driven current is balanced by a return current j p in the plasma. The j p x B torque pushes the plasma into a new rotation state both toroidally and poloidally. An anomalous toroidal viscosity is needed to avoid an extreme toroidal rotation speed. It is shown that the poloidal rotation relaxes to a new equilibrium speed, which is in general smaller than the E x B poloidal speed, and that the timescale for the relaxation of poloidal rotation is the same as that of toroidal rotation generation, which is usually much longer than the ion-ion collision time. (author)

ROTATING BULLETS FROM A VARIABLE PROTOSTAR

Energy Technology Data Exchange (ETDEWEB)

Chen, Xuepeng [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); Arce, Héctor G. [Department of Astronomy, Yale University, Box 208101, New Haven, CT 06520-8101 (United States); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Launhardt, Ralf; Henning, Thomas, E-mail: xpchen@pmo.ac.cn [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

2016-06-20

We present Submillimeter Array (SMA) CO (2–1) observations toward the protostellar jet driven by SVS 13 A, a variable protostar in the NGC 1333 star-forming region. The SMA CO (2–1) images show an extremely high-velocity jet composed of a series of molecular “bullets.” Based on the SMA CO observations, we discover clear and large systematic velocity gradients, perpendicular to the jet axis, in the blueshifted and redshifted bullets. After discussing several alternative interpretations, such as twin-jets, jet precession, warped disk, and internal helical shock, we suggest that the systematic velocity gradients observed in the bullets result from the rotation of the SVS 13 A jet. From the SMA CO images, the measured rotation velocities are 11.7–13.7 km s{sup −1} for the blueshifted bullet and 4.7 ± 0.5 km s{sup −1} for the redshifted bullet. The estimated specific angular momenta of the two bullets are comparable to those of dense cores, about 10 times larger than those of protostellar envelopes, and about 20 times larger than those of circumstellar disks. If the velocity gradients are due to the rotation of the SVS 13 A jet, the significant amount of specific angular momenta of the bullets indicates that the rotation of jets/outflows is a key mechanism to resolve the so-called “angular momentum problem” in the field of star formation. The kinematics of the bullets suggests that the jet launching footprint on the disk has a radius of ∼7.2–7.7 au, which appears to support the extended disk-wind model. We note that further observations are needed to comprehensively understand the kinematics of the SVS 13 A jet, in order to confirm the rotation nature of the bullets.

Time to Computerized Tomography Scan, Age, and Mortality in Acute Stroke.

Science.gov (United States)

Myint, Phyo Kyaw; Kidd, Andrew C; Kwok, Chun Shing; Musgrave, Stanley D; Redmayne, Oliver; Metcalf, Anthony K; Ngeh, Joseph; Nicolson, Anne; Owusu-Agyei, Peter; Shekhar, Raj; Walsh, Kevin; Day, Diana J; Warburton, Elizabeth A; Bachmann, Max O; Potter, John F

2016-12-01

Time to computerized tomography (CT) is important to institute appropriate and timely hyperacute management in stroke. We aimed to evaluate mortality outcomes in relation to age and time to CT scan. We used routinely collected data in 8 National Health Service trusts in East of England between September 2008 and April 2011. Stroke cases were prospectively identified and confirmed. Odds ratios (ORs) for unadjusted and adjusted models for age categories (24 hours) and in-hospital and early (<7 days) mortality outcomes were calculated. Of the 7693 patients (mean age 76.1 years, 50% male) included, 1151 (16%) died as inpatients and 336 (4%) died within 7 days. Older patients and those admitted from care home had a significantly longer time from admission until CT (P < .001). Patients who had earlier CT scans were admitted to stroke units more frequently (P < .001) but had higher in-patient (P < .001) and 7-day mortality (P < .001). Whereas older age was associated with increased odds of mortality outcomes, longer time to CT was associated with significantly reduced mortality within 7 days (corresponding ORs for the above time periods were 1.00, .61 [95% confidence interval {CI}: .39-.95], .39 [.24-.64], and .16 [.08-.33]) and in-hospital mortality (ORs 1.00, .86 [.64-1.15], .57 [.42-.78] and .71 [.52-.98]). Older age was associated with a significantly longer time to CT. However, using CT scan time as a benchmarking tool in stroke may have inherent limitations and does not appear to be a suitable quality marker. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Response of plasma rotation to resonant magnetic perturbations in J-TEXT tokamak

Science.gov (United States)

Yan, W.; Chen, Z. Y.; Huang, D. W.; Hu, Q. M.; Shi, Y. J.; Ding, Y. H.; Cheng, Z. F.; Yang, Z. J.; Pan, X. M.; Lee, S. G.; Tong, R. H.; Wei, Y. N.; Dong, Y. B.; J-TEXT Team

2018-03-01

The response of plasma toroidal rotation to the external resonant magnetic perturbations (RMP) has been investigated in Joint Texas Experimental Tokamak (J-TEXT) ohmic heating plasmas. For the J-TEXT’s plasmas without the application of RMP, the core toroidal rotation is in the counter-current direction while the edge rotation is near zero or slightly in the co-current direction. Both static RMP experiments and rotating RMP experiments have been applied to investigate the plasma toroidal rotation. The core toroidal rotation decreases to lower level with static RMP. At the same time, the edge rotation can spin to more than 20 km s-1 in co-current direction. On the other hand, the core plasma rotation can be slowed down or be accelerated with the rotating RMP. When the rotating RMP frequency is higher than mode frequency, the plasma rotation can be accelerated to the rotating RMP frequency. The plasma confinement is improved with high frequency rotating RMP. The plasma rotation is decelerated to the rotating RMP frequency when the rotating RMP frequency is lower than the mode frequency. The plasma confinement also degrades with low frequency rotating RMP.

Rotational motion in nuclei

International Nuclear Information System (INIS)

Bohr, A.

1976-01-01

Nuclear structure theories are reviewed concerned with nuclei rotational motion. The development of the deformed nucleus model facilitated a discovery of rotational spectra of nuclei. Comprehensive verification of the rotational scheme and a successful classification of corresponding spectra stimulated investigations of the rotational movement dynamics. Values of nuclear moments of inertia proved to fall between two marginal values corresponding to rotation of a solid and hydrodynamic pattern of an unrotating flow, respectively. The discovery of governing role of the deformation and a degree of a symmetry violence for determining rotational degrees of freedon is pointed out to pave the way for generalization of the rotational spectra

Effect of forearm axially rotated posture on shoulder load and shoulder abduction / flexion angles in one-armed arrest of forward falls.

Science.gov (United States)

Hsu, Hsiu-Hao; Chou, You-Li; Lou, Shu-Zon; Huang, Ming-Jer; Chou, Paul Pei-Hsi

2011-03-01

Falling onto the outstretched hand is the most common cause of upper extremity injury. This study develops an experimental model for evaluating the shoulder load during a simulated forward fall onto one hand with three different forearm axially rotated postures, and examines the shoulder abduction angle and shoulder flexion angle in each case. Fifteen healthy young male subjects with an average age of 23.7 years performed a series of one-armed arrests from a height of 5 cm onto a force plate. The kinematics and kinetics of the upper extremity were analyzed for three different forearm postures, namely 45° externally rotated, non-rotated, and 45° internally rotated. The shoulder joint load and shoulder abduction/flexion angles were significantly dependent on the rotational posture of the forearm. The shoulder medio-lateral shear forces in the externally rotated group were found to be 1.61 and 2.94 times higher than those in the non-rotated and internally rotated groups, respectively. The shoulder flexion angles in the externally rotated, non-rotated and internally rotated groups were 0.6°, 8.0° and 19.2°, respectively, while the corresponding shoulder abduction angles were 6.1°, 34.1° and 46.3°, respectively. In falls onto the outstretched hand, an externally rotated forearm posture should be avoided in order to reduce the medio-lateral shear force acting on the shoulder joint. In falls of this type, a 45° internally rotated forearm posture represents the most effective fall strategy in terms of minimizing the risk of upper extremity injuries. Copyright © 2010 Elsevier Ltd. All rights reserved.

Inferring probabilistic stellar rotation periods using Gaussian processes

Science.gov (United States)

Angus, Ruth; Morton, Timothy; Aigrain, Suzanne; Foreman-Mackey, Daniel; Rajpaul, Vinesh

2018-02-01

Variability in the light curves of spotted, rotating stars is often non-sinusoidal and quasi-periodic - spots move on the stellar surface and have finite lifetimes, causing stellar flux variations to slowly shift in phase. A strictly periodic sinusoid therefore cannot accurately model a rotationally modulated stellar light curve. Physical models of stellar surfaces have many drawbacks preventing effective inference, such as highly degenerate or high-dimensional parameter spaces. In this work, we test an appropriate effective model: a Gaussian Process with a quasi-periodic covariance kernel function. This highly flexible model allows sampling of the posterior probability density function of the periodic parameter, marginalizing over the other kernel hyperparameters using a Markov Chain Monte Carlo approach. To test the effectiveness of this method, we infer rotation periods from 333 simulated stellar light curves, demonstrating that the Gaussian process method produces periods that are more accurate than both a sine-fitting periodogram and an autocorrelation function method. We also demonstrate that it works well on real data, by inferring rotation periods for 275 Kepler stars with previously measured periods. We provide a table of rotation periods for these and many more, altogether 1102 Kepler objects of interest, and their posterior probability density function samples. Because this method delivers posterior probability density functions, it will enable hierarchical studies involving stellar rotation, particularly those involving population modelling, such as inferring stellar ages, obliquities in exoplanet systems, or characterizing star-planet interactions. The code used to implement this method is available online.

Rotational synkineses of occiput and atlas on lateral inclination

Energy Technology Data Exchange (ETDEWEB)

Jirout, J.

1981-02-01

An X-ray analysis was performed with regard to the question of synkinetic rotational movements of occiput and atlas on lateral inclination of the head and neck. It was found that the frequent synkinetic rotation of the head from the side of inclination can be taken for a stereotype that is ten times more frequent than the rotation towards the side of inclination. However, it does not represent an essential or indispensable feature of the synkinetic reaction. The associated rotation of the atlas from the side of inclination cannot be looked upon as a normal and constant element of the synkinetic response on lateral inclination, as it does not occur in nearly one-half of cases. Moreover, these studies have shown that the rotational movement between occiput and atlas is possible not only in the final stage of maximum forced rotation of the head, but that it belongs to normal dynamic features of the synkinetic response on lateral inclination of the head and neck.

Rotational synkineses of occiput and atlas on lateral inclination

International Nuclear Information System (INIS)

Jirout, J.

1981-01-01

An X-ray analysis was performed with regard to the question of synkinetic rotational movements of occiput and atlas on lateral inclination of the head and neck. It was found that the frequent synkinetic rotation of the head from the side of inclination can be taken for a stereotype that is ten times more frequent than the rotation towards the side of inclination. However, it does not represent an essential or indispensable feature of the synkinetic reaction. The associated rotation of the atlas from the side of inclination cannot be looked upon as a normal and constant element of the synkinetic response on lateral inclination, as it does not occur in nearly one-half of cases. Moreover, these studies have shown that the rotational movement between occiput and atlas is possible not only in the final stage of maximum forced rotation of the head, but that it belongs to normal dynamic features of the synkinetic response on lateral inclination of the head and neck. (orig.)

Optimal control of lift/drag ratios on a rotating cylinder

Science.gov (United States)

Ou, Yuh-Roung; Burns, John A.

1992-01-01

We present the numerical solution to a problem of maximizing the lift to drag ratio by rotating a circular cylinder in a two-dimensional viscous incompressible flow. This problem is viewed as a test case for the newly developing theoretical and computational methods for control of fluid dynamic systems. We show that the time averaged lift to drag ratio for a fixed finite-time interval achieves its maximum value at an optimal rotation rate that depends on the time interval.

Relationships between rotator cuff tear types and radiographic abnormalities

Energy Technology Data Exchange (ETDEWEB)

Lee, Soo Hyun; Chun, Kyung Ah; Lee Soo Jung; Kang, Min Ho; Yi, Kyung Sik; Zhang, Ying [Dept. of Diagnostic Radiology, College of Medicine, Chungbuk National University, Cheongju (Korea, Republic of)

2014-11-15

To determine relationships between different types of rotator cuff tears and radiographic abnormalities. The shoulder radiographs of 104 patients with an arthroscopically proven rotator cuff tear were compared with similar radiographs of 54 age-matched controls with intact cuffs. Two radiologists independently interpreted all radiographs for; cortical thickening with subcortical sclerosis, subcortical cysts, osteophytes in the humeral greater tuberosity, humeral migration, degenerations of the acromioclavicular and glenohumeral joints, and subacromial spurs. Statistical analysis was performed to determine relationships between each type of rotator cuff tears and radiographic abnormalities. Inter-observer agreements with respect to radiographic findings were analyzed. Humeral migration and degenerative change of the greater tuberosity, including sclerosis, subcortical cysts, and osteophytes, were more associated with full-thickness tears (p < 0.01). Subacromial spurs were more common for full-thickness and bursal-sided tears (p < 0.01). No association was found between degeneration of the acromioclavicular or glenohumeral joint and the presence of a cuff tear. Different types of rotator cuff tears are associated with different radiographic abnormalities.

Relationships between rotator cuff tear types and radiographic abnormalities

International Nuclear Information System (INIS)

Lee, Soo Hyun; Chun, Kyung Ah; Lee Soo Jung; Kang, Min Ho; Yi, Kyung Sik; Zhang, Ying

2014-01-01

To determine relationships between different types of rotator cuff tears and radiographic abnormalities. The shoulder radiographs of 104 patients with an arthroscopically proven rotator cuff tear were compared with similar radiographs of 54 age-matched controls with intact cuffs. Two radiologists independently interpreted all radiographs for; cortical thickening with subcortical sclerosis, subcortical cysts, osteophytes in the humeral greater tuberosity, humeral migration, degenerations of the acromioclavicular and glenohumeral joints, and subacromial spurs. Statistical analysis was performed to determine relationships between each type of rotator cuff tears and radiographic abnormalities. Inter-observer agreements with respect to radiographic findings were analyzed. Humeral migration and degenerative change of the greater tuberosity, including sclerosis, subcortical cysts, and osteophytes, were more associated with full-thickness tears (p < 0.01). Subacromial spurs were more common for full-thickness and bursal-sided tears (p < 0.01). No association was found between degeneration of the acromioclavicular or glenohumeral joint and the presence of a cuff tear. Different types of rotator cuff tears are associated with different radiographic abnormalities.

Electro-mechanical coupling of rotating 3D beams

Directory of Open Access Journals (Sweden)

Stoykov S.

2016-01-01

Full Text Available A rotating thin-walled beam with piezoelectric element is analysed. The beam is considered to vibrate in space, hence the longitudinal, transverse and torsional deformations are taken into account. The bending deformations of the beam are modelled by assuming Timoshenko's theory. Torsion is included by considering that the cross section rotates as a rigid body but can deform in longitudinal direction due to warping. The warping function is computed preliminary by the finite element method. The equation of motion is derived by the principle of virtual work and discretized in space by the Ritz method. Electro-mechanical coupling is included in the model by considering the internal electrical energy and the electric charge output. The piezo-electric constitutive relations are used in reduced form. The beam is assumed to rotate about a fixed axis with constant speed. The equation of motion is derived in rotating coordinate system, but the influence of the rotation of the coordinate system is taken into account through the inertia forces. Results in time domain are presented for different speeds of rotation and frequencies of vibration. The influence of the speed of rotation and of the frequency of vibration on the electrical output is presented and analysed.

External rotation immobilization for primary shoulder dislocation: a randomized controlled trial.

Science.gov (United States)

Whelan, Daniel B; Litchfield, Robert; Wambolt, Elizabeth; Dainty, Katie N

2014-08-01

The traditional treatment for primary anterior shoulder dislocations has been immobilization in a sling with the arm in a position of adduction and internal rotation. However, recent basic science and clinical data have suggested recurrent instability may be reduced with immobilization in external rotation after primary shoulder dislocation. We performed a randomized controlled trial to compare the (1) frequency of recurrent instability and (2) disease-specific quality-of-life scores after treatment of first-time shoulder dislocation using either immobilization in external rotation or immobilization in internal rotation in a group of young patients. Sixty patients younger than 35 years of age with primary, traumatic, anterior shoulder dislocations were randomized (concealed, computer-generated) to immobilization with either an internal rotation sling (n = 29) or an external rotation brace (n = 31) at a mean of 4 days after closed reduction (range, 1-7 days). Patients with large bony lesions or polytrauma were excluded. The two groups were similar at baseline. Both groups were immobilized for 4 weeks with identical therapy protocols thereafter. Blinded assessments were completed by independent observers for a minimum of 12 months (mean, 25 months; range, 12-43 months). Recurrent instability was defined as a second documented anterior dislocation or multiple episodes of shoulder subluxation severe enough for the patient to request surgical stabilization. Validated disease-specific quality-of-life data (Western Ontario Shoulder Instability index [WOSI], American Shoulder and Elbow Surgeons evaluation [ASES]) were also collected. Ten patients (17%, five from each group) were lost to followup. Reported compliance with immobilization in both groups was excellent (80%). With the numbers available, there was no difference in the rate of recurrent instability between groups: 10 of 27 patients (37%) with the external rotation brace versus 10 of 25 patients (40%) with the

Isokinetic strength of shoulder internal and external rotators in cricket bowlers

Directory of Open Access Journals (Sweden)

X.M. Mabasa

2002-02-01

Full Text Available The strength of the shoulder internal and external rotators incricket bowlers, may not be sufficient to cope with the demands of bowling.As very little research has been done on cricketers, this study was done to establish the isokinetic strength profile of the shoulder internal andexternal rotators in cricket bowlers.Isokinetic, shoulder rotational strength was evaluated in thirty malecricket volunteers with a mean age of 23.9 years and mean body weight of 70.3 kgs. The Cybex 340 dynamometer multi joint system was used to collect data on shoulder rotation strength in a standing neutral position. Data were collected at four different speeds (60,90,180 and 300deg/sec and were computed for peak torque values for internal and external ratios for both dominant and non dominant shoulders.The results showed no statistically significant difference in the mean shoulder rotational torque between the bowlingand non-bowling shoulders for external rotation (p>0.05, and indicated statistically significant differences in themean shoulder rotational torque between the bowling and non-bowling shoulders for internal rotation (p<0.05. Therewas a significant decrease in isokinetic peak torque production for the external/internal rotator muscles as the speedof contraction increased (p<0.05. The peak torque ratio for the external/internal rotator muscles of the bowling armwere significantly less than of the non-bowling arm (p<0.05. These findings suggest that the strength ratios of thebowling arm need to be considered when managing young cricketers and their injuries.

Noise test system of rotating machinery in nuclear power station based on microphone array

Science.gov (United States)

Chang, Xincai; Guan, Jishi; Qi, Liangcai

2017-12-01

Rotating machinery plays an important role in all walks of life. Once the equipment fails, equipment maintenance and shutdown will cause great social harm and economic losses. Equipment safety operations at nuclear power stations have always been of top priority. It is prone to noise when the equipment is out of order or aging. Failure to find or develop equipment at the initial stage of equipment failure or ageing will pose a serious threat to the safety of the plant’s equipment. In this paper, sound imaging diagnosis technology is applied as a supplementary method to the condition monitoring and diagnosis system of rotating machinery in nuclear power stations. It provides a powerful guarantee for the condition monitoring and fault diagnosis of rotating machinery in nuclear power stations.

Percutaneous vertebroplasty with the rotational fluoroscopy imaging technique

Energy Technology Data Exchange (ETDEWEB)

Cannavale, Alessandro; Salvatori, Filippo Maria; Wlderk, Andrea; Cirelli, Carlo; D' Adamo, Alessandro; Fanelli, Fabrizio [University of Rome, Vascular and Interventional Unit, Department of Radiological Sciences, Rome (Italy)

2014-11-15

To evaluate the feasibility of the rotational angiography unit (RAU) as a single technique to guide percutaneous vertebroplasty (PVP). Twenty-five consecutive patients (35 vertebral bodies, 20 lumbar and 15 thoracic) were treated using RA fluoroscopy. Using a state-of-the-art flat-panel angiographer (Artis zee, Siemens, Erlangen, Germany), rotational acquisitions were obtained in all patients for immediate post-procedure 2D/3D reconstructions. Pre- and postoperative back pain was assessed with the visual analog scale (VAS). Fluoroscopy time, patient radiation dose exposure, technical success, mean procedure time, mean number of rotational acquisitions and procedural complications were recorded. All features were compared with a historical cohort of patients (N = 25) who underwent PVP under CT and mobile C-arm fluoroscopy guidance. In all cases, safe and accurate control of the needle insertion and bone-cement injection was successfully obtained with high-quality fluoroscopy images. One cement leakage was detected in the RAU group, and two leakages were detected in the CT and C-arm fluoroscopy group. Technical features were significantly different between the two groups (RAU vs. CT): mean procedure time: 38.2 min vs. 60.2 min (p = 0.02); median fluoroscopy time: 14.58 and 4.58 min (p = 0.02); median number of rotational acquisitions: 5 vs. 10 (p = 0.02); mean patient dose: 6 ± 1.3 mSv vs. 23 ± 1.3 mSv (p = 0.02). There were minor complications (pain, small hematoma) in two patients (8%) in the study group and three cases (12%) in the control group. RAU guidance is an effective and safe technique for performing PVP because it reduces the procedural time and radiation exposure. (orig.)

Differential rotation of stars with multiple transiting planets

Science.gov (United States)

Netto, Yuri; Valio, Adriana

2017-10-01

If a star hosts a planet in an orbit such that it eclipses the star periodically, can be estimated the rotation profile of this star. If planets in multiplanetary system occult different stellar areas, spots in more than one latitude of the stellar disc can be detected. The monitored study of theses starspots in different latitudes allow us to infer the rotation profile of the star. We use the model described in Silva (2003) to characterize the starspots of Kepler-210, an active star with two planets. Kepler-210 is a late K star with an estimated age of 350 +/- 50 Myrs, average rotation period of 12.33 days, mass of 0.63 M⊙ and radius of 0.69 R⊙. The planets that eclipses this star have radii of 0.0498 R s and 0.0635 R s with orbital periods of 2.4532 +/- 0.0007 days and 7.9725 +/- 0.0014 days, respectively, where R s is the star radius.

Beyond chronological age: examining time and health as age-related mediators in relations to work motives

NARCIS (Netherlands)

Kooij, T.A.M.; de Lange, A.H.; Jansen, P.G.W.; Dikkers, J.S.E.

2013-01-01

Since workforces across the world are aging, researchers and organizations need more insight into how and why occupational well-being, together with work-related attitudes and motivations, change with age. Lifespan theories point to subjective health and future time perspective (i.e. an individual's

Rotational spectrum of tryptophan

Energy Technology Data Exchange (ETDEWEB)

Sanz, M. Eugenia, E-mail: maria.sanz@kcl.ac.uk; Cabezas, Carlos, E-mail: ccabezas@qf.uva.es; Mata, Santiago, E-mail: santiago.mata@uva.es; Alonso, Josè L., E-mail: jlalonso@qf.uva.es [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico Uva, Universidad de Valladolid, 47011 Valladolid (Spain)

2014-05-28

The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the {sup 14}N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O–H···N hydrogen bond in the side chain and a N–H···π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

Surface dimpling on rotating work piece using rotation cutting tool

Science.gov (United States)

Bhapkar, Rohit Arun; Larsen, Eric Richard

2015-03-31

A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

The analysis on centrifugal compressor rotating stall

International Nuclear Information System (INIS)

Kim, Ji Hwan; Kim, Kwang Ho; Shin, You Hwan

2003-01-01

In the present study, the performance characteristics and the number of stall cell during rotating stall of a centrifugal air compressor were experimentally investigated. Rotating stall in the vaneless diffuser were investigated by measuring unsteady pressure fluctuations at several different diffuser radius using a high frequency pressure transducer. The number of stall cell and their rotational speeds are distinctive features of the rotating stall phenomenon. The present study is mainly forced on the analysis for the stall cell number and its propagation speed unstable operating region of the compressor. The interpretation method of visualization is based on the pressure distribution in the circumference pressure fields while plotting the pressure and its harmonics variations in time in polar coordinates. To obtain the visualize the existence rotating stall, auto-correlation function and the frequency spectra of the pressure fluctuations were measured at r/r2=1.52. When the flow coefficient is lower than 0.150, the static pressure at impeller inlet is higher than that at inlet duct of the compressor. And the flow coefficient is lower than 0.086, several stall cell groups of discrete frequencies are observed

Effect of head rotation in whiplash-type rear impacts.

Science.gov (United States)

Kumar, Shrawan; Ferrari, Robert; Narayan, Yogesh

2005-01-01

Knowledge is increasing about the electromyographic and kinematic response of the neck muscles to rear impact, and also recent information is available on the effect of a rear impact offset to the left (posterolateral). The effect of head rotation, however, at the time of rear impact is not known. The purpose of this study was to examine the effects of head rotation to the left and right on the cervical muscle response to increasing low-velocity posterolateral impacts. Twenty healthy volunteers were subjected to rear impacts of 4.7, 8.3, 10.9 and 13.7 m/s2 acceleration, offset by 45 degrees to the subject's left, with head rotation to right and left. Bilateral electromyograms of the sternocleidomastoids, trapezii and splenii capitis were recorded. Triaxial accelerometers recorded the acceleration of the sled, torso at the shoulder level, and head of the participant. With the head rotated to the right, at an acceleration of 13.7 m/s2, the left sternocleidomastoid generated 59% and the right sternocleidomastoid 20% of their maximal voluntary contraction (MVC) electromyogram (EMG). Under these conditions, the remaining muscles (both splenii capitis and trapezius) generated 25% or less of their MVC. With the head rotated to the left, at an acceleration of 13.7 m/s2, the right sternocleidomastoid generated 65% and the left sternocleidomastoid only 11% of the MVC EMG. Under these conditions, again the remaining muscles had low EMG activity (27% or less) with the exception of the left trapezius which generated 47% of its MVC. Electromyographic variables were significantly affected by the levels of acceleration (pfactor in determining the muscle response to whiplash, but head rotation at the time of impact is also important in this regard. More specifically, when a rear impact is left posterolateral, it results in increased EMG generation mainly in the contralateral sternocleidomastoid, as expected, but head rotation at the same time in this type of impact reduces the EMG

A new corrective technique for adolescent idiopathic scoliosis (Ucar′s convex rod rotation

Directory of Open Access Journals (Sweden)

Bekir Yavuz Ucar

2014-01-01

Full Text Available Study Design: Prospective single-center study. Objective: To analyze the efficacy and safety of a new technique of global vertebral correction with convex rod rotation performed on the patients with adolescent idiopathic scoliosis. Summary of Background Data: Surgical goal is to obtain an optimal curve correction in scoliosis surgery. There are various correction techniques. This report describes a new technique of global vertebral correction with convex rod rotation. Materials and Methods: A total of 12 consecutive patients with Lenke type I adolescent idiopathic scoliosis and managed by convex rod rotation technique between years 2012 and 2013 having more than 1 year follow-up were included. Mean age was 14.5 (range = 13-17 years years at the time of operation. The hospital charts were reviewed for demographic data. Measurements of curve magnitude and balance were made on 36-inch standing anteroposterior and lateral radiographs taken before surgery and at most recent follow up to assess deformity correction, spinal balance, and complications related to the instrumentation. Results: Preoperative coronal plane major curve of 62° (range = 50°-72° with flexibility of less than 30% was corrected to 11.5°(range = 10°-14° showing a 81% scoliosis correction at the final follow-up. Coronal imbalance was improved 72% at the most recent follow-up assessment. No complications were found. Conclusion: The new technique of global vertebral correction with Ucar′s convex rod rotation is an effective technique. This method is a vertebral rotation procedure from convex side and it allows to put screws easily to the concave side.

Rotation sensor switch

International Nuclear Information System (INIS)

Sevec, J.B.

1978-01-01

A protective device to provide a warning if a piece of rotating machinery slows or stops is comprised of a pair of hinged weights disposed to rotate on a rotating shaft of the equipment. When the equipment is rotating, the weights remain in a plane essentially perpendicular to the shaft and constitute part of an electrical circuit that is open. When the shaft slows or stops, the weights are attracted to a pair of concentric electrically conducting disks disposed in a plane perpendicular to the shaft and parallel to the plane of the weights when rotating. A disk magnet attracts the weights to the electrically conducting plates and maintains the electrical contact at the plates to complete an electrical circuit that can then provide an alarm signal

Rotational dynamics in supercooled water from nuclear spin relaxation and molecular simulations.

Science.gov (United States)

Qvist, Johan; Mattea, Carlos; Sunde, Erik P; Halle, Bertil

2012-05-28

Structural dynamics in liquid water slow down dramatically in the supercooled regime. To shed further light on the origin of this super-Arrhenius temperature dependence, we report high-precision (17)O and (2)H NMR relaxation data for H(2)O and D(2)O, respectively, down to 37 K below the equilibrium freezing point. With the aid of molecular dynamics (MD) simulations, we provide a detailed analysis of the rotational motions probed by the NMR experiments. The NMR-derived rotational correlation time τ(R) is the integral of a time correlation function (TCF) that, after a subpicosecond librational decay, can be described as a sum of two exponentials. Using a coarse-graining algorithm to map the MD trajectory on a continuous-time random walk (CTRW) in angular space, we show that the slowest TCF component can be attributed to large-angle molecular jumps. The mean jump angle is ∼48° at all temperatures and the waiting time distribution is non-exponential, implying dynamical heterogeneity. We have previously used an analogous CTRW model to analyze quasielastic neutron scattering data from supercooled water. Although the translational and rotational waiting times are of similar magnitude, most translational jumps are not synchronized with a rotational jump of the same molecule. The rotational waiting time has a stronger temperature dependence than the translation one, consistent with the strong increase of the experimentally derived product τ(R) D(T) at low temperatures. The present CTRW jump model is related to, but differs in essential ways from the extended jump model proposed by Laage and co-workers. Our analysis traces the super-Arrhenius temperature dependence of τ(R) to the rotational waiting time. We present arguments against interpreting this temperature dependence in terms of mode-coupling theory or in terms of mixture models of water structure.

Rotational Response of Toe-Restrained Retaining Walls to Earthquake Ground Motions

National Research Council Canada - National Science Library

Ebeling, Robert M; White, Barry C

2006-01-01

.... The PC software CorpsWallRotate (sometimes referred to as CWRotate) was developed to perform an analysis of permanent wall rotation for each proposed retaining wall section to a user-specified earthquake acceleration time-history...

An Improved Model of Cryogenic Propellant Stratification in a Rotating, Reduced Gravity Environment

Science.gov (United States)

Oliveira, Justin; Kirk, Daniel R.; Schallhorn, Paul A.; Piquero, Jorge L.; Campbell, Mike; Chase, Sukhdeep

2007-01-01

This paper builds on a series of analytical literature models used to predict thermal stratification within rocket propellant tanks. The primary contribution to the literature is to add the effect of tank rotation and to demonstrate the influence of rotation on stratification times and temperatures. This work also looks levels of thermal stratification for generic propellant tanks (cylindrical shapes) over a parametric range of upper-stage coast times, heating levels, rotation rates, and gravity levels.

Improved apparatus for predictive diagnosis of rotator cuff disease

Science.gov (United States)

Pillai, Anup; Hall, Brittany N.; Thigpen, Charles A.; Kwartowitz, David M.

2014-03-01

Rotator cuff disease impacts over 50% of the population over 60, with reports of incidence being as high as 90% within this population, causing pain and possible loss of function. The rotator cuff is composed of muscles and tendons that work in tandem to support the shoulder. Heavy use of these muscles can lead to rotator cuff tear, with the most common causes is age-related degeneration or sport injuries, both being a function of overuse. Tears ranges in severity from partial thickness tear to total rupture. Diagnostic techniques are based on physical assessment, detailed patient history, and medical imaging; primarily X-ray, MRI and ultrasonography are the chosen modalities for assessment. The final treatment technique and imaging modality; however, is chosen by the clinician is at their discretion. Ultrasound has been shown to have good accuracy for identification and measurement of full-thickness and partial-thickness rotator cuff tears. In this study, we report on the progress and improvement of our method of transduction and analysis of in situ measurement of rotator cuff biomechanics. We have improved the ability of the clinician to apply a uniform force to the underlying musculotendentious tissues while simultaneously obtaining the ultrasound image. This measurement protocol combined with region of interest (ROI) based image processing will help in developing a predictive diagnostic model for treatment of rotator cuff disease and help the clinicians choose the best treatment technique.

Medial Entorhinal Grid Cells and Head Direction Cells Rotate with a T-Maze More Often During Less Recently Experienced Rotations

Science.gov (United States)

Gupta, Kishan; Beer, Nathan J.; Keller, Lauren A.; Hasselmo, Michael E.

2014-01-01

Prior studies of head direction (HD) cells indicate strong landmark control over the preferred firing direction of these cells, with few studies exhibiting shifts away from local reference frames over time. We recorded spiking activity of grid and HD cells in the medial entorhinal cortex of rats, testing correlations of local environmental cues with the spatial tuning curves of these cells' firing fields as animals performed continuous spatial alternation on a T-maze that shared the boundaries of an open-field arena. The environment was rotated into configurations the animal had either seen or not seen in the past recording week. Tuning curves of both cell types demonstrated commensurate shifts of tuning with T-maze rotations during less recent rotations, more so than recent rotations. This strongly suggests that animals are shifting their reference frame away from the local environmental cues over time, learning to use a different reference frame more likely reliant on distal or idiothetic cues. In addition, grid fields demonstrated varying levels of “fragmentation” on the T-maze. The propensity for fragmentation does not depend on grid spacing and grid score, nor animal trajectory, indicating the cognitive treatment of environmental subcompartments is likely driven by task demands. PMID:23382518

Rotation number of integrable symplectic mappings of the plane

Energy Technology Data Exchange (ETDEWEB)

Zolkin, Timofey [Fermilab; Nagaitsev, Sergei [Fermilab; Danilov, Viatcheslav [Oak Ridge

2017-04-11

Symplectic mappings are discrete-time analogs of Hamiltonian systems. They appear in many areas of physics, including, for example, accelerators, plasma, and fluids. Integrable mappings, a subclass of symplectic mappings, are equivalent to a Twist map, with a rotation number, constant along the phase trajectory. In this letter, we propose a succinct expression to determine the rotation number and present two examples. Similar to the period of the bounded motion in Hamiltonian systems, the rotation number is the most fundamental property of integrable maps and it provides a way to analyze the phase-space dynamics.

An Improved Rotation Forest for Multi-Feature Remote-Sensing Imagery Classification

Directory of Open Access Journals (Sweden)

Yingchang Xiu

2017-11-01

Full Text Available Multi-feature, especially multi-temporal, remote-sensing data have the potential to improve land cover classification accuracy. However, sometimes it is difficult to utilize all the features efficiently. To enhance classification performance based on multi-feature imagery, an improved rotation forest, combining Principal Component Analysis (PCA and a boosting naïve Bayesian tree (NBTree, is proposed. First, feature extraction was carried out with PCA. The feature set was randomly split into several disjoint subsets; then, PCA was applied to each subset, and new training data for linear extracted features based on original training data were obtained. These steps were repeated several times. Second, based on the new training data, a boosting naïve Bayesian tree was constructed as the base classifier, which aims to achieve lower prediction error than a decision tree in the original rotation forest. At the classification phase, the improved rotation forest has two-layer voting. It first obtains several predictions through weighted voting in a boosting naïve Bayesian tree; then, the first-layer vote predicts by majority to obtain the final result. To examine the classification performance, the improved rotation forest was applied to multi-feature remote-sensing images, including MODIS Enhanced Vegetation Index (EVI imagery time series, MODIS Surface Reflectance products and ancillary data in Shandong Province for 2013. The EVI imagery time series was preprocessed using harmonic analysis of time series (HANTS to reduce the noise effects. The overall accuracy of the final classification result was 89.17%, and the Kappa coefficient was 0.71, which outperforms the original rotation forest and other classifier ensemble results, as well as the NASA land cover product. However, this new algorithm requires more computational time, meaning the efficiency needs to be further improved. Generally, the improved rotation forest has a potential advantage in

Helical modes generate antimagnetic rotational spectra in nuclei

Science.gov (United States)

Malik, Sham S.

2018-03-01

A systematic analysis of the antimagnetic rotation band using r -helicity formalism is carried out for the first time. The observed octupole correlation in a nucleus is likely to play a role in establishing the antimagnetic spectrum. Such octupole correlations are explained within the helical orbits. In a rotating field, two identical fermions (generally protons) with paired spins generate these helical orbits in such a way that its positive (i.e., up) spin along the axis of quantization refers to one helicity (right-handedness) while negative (down) spin along the same quantization-axis decides another helicity (left-handedness). Since the helicity remains invariant under rotation, therefore, the quantum state of a fermion is represented by definite angular momentum and helicity. These helicity represented states support a pear-shaped structure of a rotating system having z axis as the symmetry axis. A combined operation of parity, time-reversal, and signature symmetries ensures an absence of one of the signature partner band from the observed antimagnetic spectrum. This formalism has also been tested for the recently observed negative parity Δ I =2 antimagnetic spectrum in odd-A 101Pd nucleus and explains nicely its energy spectrum as well as the B (E 2 ) values. Further, this formalism is found to be fully consistent with twin-shears mechanism popularly known for such type of rotational bands. It also provides significant clue for extending these experiments in various mass regions spread over the nuclear chart.

Rotational Mal-Alignment after Reamed Intramedullary Nailing for tibial shaft fracture.

Science.gov (United States)

Khan, Sher Baz; Mohib, Yasir; Rashid, Rizwan Haroon; Rashid, Haroonur

2016-10-01

Intra-medullary (IM) nailing is standard of care for unstable tibial shaft fractures. Malrotation is very common but it is under-recognised, inpart because of variation in normal anatomy and partly due to difficulty in accurately assessing rotation. This study was planned to evaluate the frequency of rotational mal-alignment after reamed tibia IMnailing. This cross-sectional study was conducted at Aga khan University Hospital, Karachi, and comprised patients with tibia shaft fractures managed with IMnailing from January to December 2014. All the patients were assessed intra-operatively for rotational alignment using the knee and ankle fluoroscopic images. There were 81 patients with a mean age of 38±16.9 years. There were 64(79%) male patients. Overall the incidence of malrotation was in 20(24.7%) cases. Rotational mal-alignment is one of the preventable complications after IMnailing which can be assesed intra-operatively under fluoroscope.

Experimental studies of rotating exchange flow

Science.gov (United States)

Rabe, B.; Smeed, D. A.; Dalziel, S. B.; Lane-Serff, G. F.

2007-02-01

Ocean basins are connected by straits and passages, geometrically limiting important heat and salt exchanges which in turn influence the global thermohaline circulation and climate. Such exchange can be modeled in an idealized way by taking into consideration the density-driven two-layer flow along a strait under the influence of rotation. We use a laboratory model of a lock exchange between two reservoirs of different density through a flat-bottom channel with a horizontal narrows, set up on two different platforms: a 1 m diameter turntable, where density interface position was measured by dye attenuation, and the 14 m diameter turntable at Coriolis/LEGI (Grenoble, France), where correlation imaging velocimetry, a particle imaging technique, allowed us to obtain for the first time detailed measurements of the velocity fields in these flows. The influence of rotation is studied by varying a parameter, Bu, a type of Burger number given by the ratio of the Rossby radius to the channel width at the narrows. In addition, a two-layer version of the Miami Isopycnic Coordinate Model (MICOM) is used, to study the cases with low Burger number. Results from experiments by Dalziel [1988. Two-layer hydraulics: maximal exchange flows. Ph.D. Thesis, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, see also people/sd103/papers/1988/Thesis_Dalziel.pdf>] are also included for comparison. Time-mean exchange fluxes for any Bu are in close agreement with the inviscid zero-potential vorticity theory of Dalziel [1990. Rotating two-layer sill flows. In: Pratt, L.J. (Ed.), The Physical Oceanography of Sea Straits. Kluwer Academic, Dordrecht, pp. 343-371] and Whitehead et al. [1974. Rotating hydraulics of strait and sill flows. Geophysical Fluid Dynamics 6, 101-125], who found that fluxes for Bu>1 mainly vary with channel width, similar to non-rotating flow, but for Bu1 a steady, two-layer flow was observed that persisted across the channel at the narrows

Identify the Rotating Stall in Centrifugal Compressors by Fractal Dimension in Reconstructed Phase Space

Directory of Open Access Journals (Sweden)

Le Wang

2015-11-01

Full Text Available Based on phase space reconstruction and fractal dynamics in nonlinear dynamics, a method is proposed to extract and analyze the dynamics of the rotating stall in the impeller of centrifugal compressor, and some numerical examples are given to verify the results as well. First, the rotating stall of an existing low speed centrifugal compressor (LSCC is numerically simulated, and the time series of pressure in the rotating stall is obtained at various locations near the impeller outlet. Then, the phase space reconstruction is applied to these pressure time series, and a low-dimensional dynamical system, which the dynamics properties are included in, is reconstructed. In phase space reconstruction, C–C method is used to obtain the key parameters, such as time delay and the embedding dimension of the reconstructed phase space. Further, the fractal characteristics of the rotating stall are analyzed in detail, and the fractal dimensions are given for some examples to measure the complexity of the flow in the post-rotating stall. The results show that the fractal structures could reveal the intrinsic dynamics of the rotating stall flow and could be considered as a characteristic to identify the rotating stall.

EBR-II rotating plug seal maintenance

International Nuclear Information System (INIS)

Allen, K.J.

1986-01-01

The EBR-II rotating plug seals require frequent cleaning and maintenance to keep the plugs from sticking during fuel handling. Time consuming cleaning on the cover gas and air sides of the dip ring seal is required to remove oxidation and sodium reaction products that accumulate and stop plug rotation. Despite severely limited access, effective seal cleaning techniques have removed 11 800 lb (5 352 kg) of deposits from the seals since 1964. Temperature control modifications and repairs have also required major maintenance work. Suggested seal design recommendations could significantly reduce maintenance on future similar seals

Effecting aging time of epoxy molding compound to molding process for integrated circuit packaging

Science.gov (United States)

Tachapitunsuk, Jirayu; Ugsornrat, Kessararat; Srisuwitthanon, Warayoot; Thonglor, Panakamon

2017-09-01

This research studied about effecting aging time of epoxy molding compound (EMC) that effect to reliability performance of integrated circuit (IC) package in molding process. Molding process is so important of IC packaging process for protecting IC chip (or die) from temperature and humidity environment using encapsulated EMC. For general molding process, EMC are stored in the frozen at 5°C and left at room temperature at 25 °C for aging time on self before molding of die onto lead frame is 24 hours. The aging time effect to reliability performance of IC package due to different temperature and humidity inside the package. In experiment, aging time of EMC were varied from 0 to 24 hours for molding process of SOIC-8L packages. For analysis, these packages were tested by x-ray and scanning acoustic microscope to analyze properties of EMC with an aging time and also analyzed delamination, internal void, and wire sweep inside the packages with different aging time. The results revealed that different aging time of EMC effect to properties and reliability performance of molding process.

Rotationally invariant correlation filtering

International Nuclear Information System (INIS)

Schils, G.F.; Sweeney, D.W.

1985-01-01

A method is presented for analyzing and designing optical correlation filters that have tailored rotational invariance properties. The concept of a correlation of an image with a rotation of itself is introduced. A unified theory of rotation-invariant filtering is then formulated. The unified approach describes matched filters (with no rotation invariance) and circular-harmonic filters (with full rotation invariance) as special cases. The continuum of intermediate cases is described in terms of a cyclic convolution operation over angle. The angular filtering approach allows an exact choice for the continuous trade-off between loss of the correlation energy (or specificity regarding the image) and the amount of rotational invariance desired

High-Frequency Dynamic Nuclear Polarization in the Nuclear Rotating Frame

DEFF Research Database (Denmark)

Farrar, C. T.; Hall, D. A.; Gerfen, G. J.

2000-01-01

A proton dynamic nuclear polarization (DNP) NMR signal enhancement (ϵ) close to thermal equilibrium, ϵ = 0.89, has been obtained at high field (B0 = 5 T, νepr = 139.5 GHz) using 15 mM trityl radical in a 40:60 water/glycerol frozen solution at 11 K. The electron-nuclear polarization transfer...... is performed in the nuclear rotating frame with microwave irradiation during a nuclear spin-lock pulse. The growth of the signal enhancement is governed by the rotating frame nuclear spin–lattice relaxation time (T1ρ), which is four orders of magnitude shorter than the nuclear spin–lattice relaxation time (T1n......). Due to the rapid polarization transfer in the nuclear rotating frame the experiment can be recycled at a rate of 1/T1ρ and is not limited by the much slower lab frame nuclear spin–lattice relaxation rate (1/T1n). The increased repetition rate allowed in the nuclear rotating frame provides an effective...

Earth Rotation Dynamics: Review and Prospects

Science.gov (United States)

Chao, Benjamin F.

2004-01-01

Modem space geodetic measurement of Earth rotation variations, particularly by means of the VLBI technique, has over the years allowed studies of Earth rotation dynamics to advance in ever-increasing precision, accuracy, and temporal resolution. A review will be presented on our understanding of the geophysical and climatic causes, or "excitations", for length-of-day change, polar motion, and nutations. These excitations sources come from mass transports that constantly take place in the Earth system comprised of the atmosphere, hydrosphere, cryosphere, lithosphere, mantle, and the cores. In this sense, together with other space geodetic measurements of time-variable gravity and geocenter motion, Earth rotation variations become a remote-sensing tool for the integral of all mass transports, providing valuable information about the latter on a wide range of spatial and temporal scales. Future prospects with respect to geophysical studies with even higher accuracy and resolution will be discussed.

KIC 9451096: Magnetic Activity, Flares and Differential Rotation

Science.gov (United States)

Özdarcan, O.; Yoldaş, E.; Dal, H. A.

2018-04-01

We present a spectroscopic and photometric analysis of KIC 9451096. The combined spectroscopic and photometric modelling shows that the system is a detached eclipsing binary in a circular orbit and composed of F5V + K2V components. Subtracting the best-fitting light curve model from the whole long cadence data reveals additional low (mmag) amplitude light variations in time and occasional flares, suggesting a low, but still remarkable level of magnetic spot activity on the K2V component. Analyzing the rotational modulation of the light curve residuals enables us to estimate the differential rotation coefficient of the K2V component as k = 0.069 ± 0.008, which is 3 times weaker compared with the solar value of k = 0.19, assuming a solar type differential rotation. We find the stellar flare activity frequency for the K2V component as 0.000368411 h-1 indicating a low magnetic activity level.

A high-resolution spectropolarimetric survey of Herbig Ae/Be stars - II. Rotation

Science.gov (United States)

Alecian, E.; Wade, G. A.; Catala, C.; Grunhut, J. H.; Landstreet, J. D.; Böhm, T.; Folsom, C. P.; Marsden, S.

2013-02-01

We report the analysis of the rotational properties of our sample of Herbig Ae/Be (HAeBe) and related stars for which we have obtained high-resolution spectropolarimetric observations. Using the projected rotational velocities measured at the surface of the stars, we have calculated the angular momentum of the sample and plotted it as a function of age. We have then compared the angular momentum and the v sin i distributions of the magnetic to the non-magnetic HAeBe stars. Finally, we have predicted v sin i of the non-magnetic, non-binary (`normal') stars in our sample when they reach the zero-age main sequence (ZAMS), and compared them to various catalogues of v sin i of main-sequence stars. First, we observe that magnetic HAeBe stars are much slower rotators than normal stars, indicating that they have been more efficiently braked than the normal stars. In fact, the magnetic stars have already lost most of their angular momentum, despite their young ages (lower than 1 Myr for some of them). Secondly, our analysis suggests that the low-mass (1.5 5 M⊙) are losing angular momentum. We propose that winds, which are expected to be stronger in massive stars, are at the origin of this phenomenon.

Critical period and risk factors for retear following arthroscopic repair of the rotator cuff

NARCIS (Netherlands)

Barth, J.; Andrieu, K.; Fotiadis, E.; Hannink, G.J.; Barthelemy, R.; Saffarini, M.

2017-01-01

PURPOSE: The incidence of retear following rotator cuff repair remains a major concern, and the cause and timing of retear remain unclear. The aim of this study was to prospectively investigate the timing of retears following rotator cuff repair at multiple time intervals. The hypothesis was that

High-efficiency free-form condenser overcoming rotational symmetry limitations.

Science.gov (United States)

Miñano, Juan C; Benítez, Pablo; Blen, José; Santamaría, Asunción

2008-12-08

Conventional condensers using rotational symmetric devices perform far from their theoretical limits when transferring optical power from sources such as arc lamps or halogen bulbs to the rectangular entrance of homogenizing prisms (target). We present a free-form condenser design (calculated with the SMS method) that overcomes the limitations inherent to rotational devices and can send to the target 1.8 times the power sent by an equivalent elliptical condenser for a 4:1 target aspect ratio and 1.5 times for 16:9 target and for practical values of target etendue.

Relative Age Effect and Academic Timing in American Junior College Baseball.

Science.gov (United States)

Beals, Thomas C; Furtado, Ovande; Fontana, Fabio E

2018-02-01

Previous research has shown that older athletes within age groupings are often perceived to be more talented simply due to advanced maturity, leading to biased selection in higher levels of sports competition, now commonly termed relative age effect (RAE). This study's goals were to determine whether (a) RAE influenced the selection of junior college baseball participants and (b) academic timing ( Glamser & Marciani, 1992 ), in which academic status determines age groupings more than strict age guidelines for college sports, influenced the formation of RAE. Participants were 150 junior college baseball players. Our results showed that RAE was only a significant factor, comparing the birth distribution of participants born before and after the midpoint of the participation year, when academic timing was also a factor in determining age groupings. In addition, the birth rate distribution, though not significantly different than expected, was greater only when those participants born during the expected participation year were included. The results of this study indicate that RAE could bear more influence among American student-athletes than was previously reported in that RAE in conjunction with academic timing does influence the selection of collegiate athletes.

NH3 quantum rotators in Hofmann clathrates: intensity and width of rotational transition lines

International Nuclear Information System (INIS)

Vorderwisch, Peter; Sobolev, Oleg; Desmedt, Arnaud

2004-01-01

Inelastic structure factors for rotational transitions of uniaxial NH 3 quantum rotators, measured in a Hofmann clathrate with biphenyl as guest molecule, agree with those calculated for free rotators. A finite intrinsic line width, found for rotational transitions involving the rotational level j=3 at low temperature, supports a recently suggested model based on resonant rotor-rotor coupling

Rotation Frequencies of Small Jovian Trojan Asteroids: An Excess of Slow Rotators

Science.gov (United States)

French, Linda M.; Stephens, Robert D.; James, David J.; Coley, Daniel; Connour, Kyle

2015-11-01

Several lines of evidence support a common origin for, and possible hereditary link between, cometary nuclei and jovian Trojan asteroids. Due to their distance and low albedos, few comet-sized Trojans have been studied. We discuss the rotation properties of Jovian Trojan asteroids less than 30 km in diameter. Approximately half the 131 objects discussed here were studied using densely sampled lightcurves (French et al. 2015a, b); Stephens et al. 2015), and the other half were sparse lightcurves obtained by the Palomar Transient Factory (PTF; Waszcazk et al. 2015).A significant fraction (~40%) of the objects in the ground-based sample rotate slowly (P > 24h), with measured periods as long as 375 h (Warner and Stephens 2011). The PTF data show a similar excess of slow rotators. Only 5 objects in the combined data set have rotation periods of less than six hours. Three of these fast rotators were contained in the data set of French et al. these three had a geometric mean rotation period of 5.29 hours. A prolate spheroid held together by gravity rotating with this period would have a critical density of 0.43 gm/cm3, a density similar to that of comets (Lamy et al. 2004).Harris et al. (2012) and Warner et al. (2011) have explored the possible effects on asteroid rotational statistics with the results from wide-field surveys. We will examine Trojan rotation statistics with and without the results from the PTF.

Steady supersonic rotation in the Maryland Centrifugal Experiment

International Nuclear Information System (INIS)

Ellis, R.F.; Messer, S.; Case, A.; DeSilva, A.; Elton, R.; Ghosh, J.; Griem, H.; Gupta, D.; Hassam, A.; Lunsford, R.; McLaren, R.; Rodgers, J.; Teodorescu, C.

2005-01-01

The Maryland Centrifugal Experiment (MCX) studies enhanced confinement and stability produced by sheared supersonic rotation about a linear confining magnetic field. MCX has a mirror geometry of 2.5 m length, mirror ratio 2-20, maximum mirror field 1.9T, maximum midplane field 0.33T. Biasing of an inner electrode relative to the outer wall produces a radial electric field which drives azimuthal rotation. MCX has achieved high density (n>10 20 m -3 ) fully ionized plasmas rotating supersonically with velocities of ∼100 km/sec for times exceeding 8 ms under a wide range of conditions. Ion temperatures are 30 eV and confinement times ∼100 microseconds. Sonic Mach numbers are 1-2 and Alfven Mach numbers somewhat less than 0.5 for standard discharges. Plasmas remain grossly stable, or steady, for many milliseconds, much longer than MHD instability timescales for MCX, though significant magnetic fluctuations are clearly seen on magnetic probes. Recently MCX has demonstrated an enhanced mode of operation with sonic Mach numbers greater than 3, confinement times of several hundred microseconds and Alfven Mach numbers near one. (author)

A ROTATIONALLY POWERED MAGNETAR NEBULA AROUND SWIFT J1834.9–0846

Energy Technology Data Exchange (ETDEWEB)

Torres, Diego F. [Institute of Space Sciences (IEEC-CSIC), Campus UAB, Carrer de Magrans s/n, E-08193 Barcelona (Spain)

2017-01-20

A wind nebula generating extended X-ray emission was recently detected surrounding Swift J1834.9–0846. This is the first magnetar for which such a wind nebula was found. Here, we investigate whether there is a plausible scenario where the pulsar wind nebula (PWN) can be sustained without the need of advocating for additional sources of energy other than rotational. We do this by using a detailed radiative and dynamical code that studies the evolution of the nebula and its particle population in time. We find that such a scenario indeed exists: Swift J1834.9–0846's nebula can be explained as being rotationally powered, as all other known PWNe are, if it is currently being compressed by the environment. The latter introduces several effects, the most important of which is the appearance of adiabatic heating, being increasingly dominant over the escape of particles as reverberation goes by. The need of reverberation naturally explains why this is the only magnetar nebula detected and provides estimates for Swift 1834.9–0846's age.

Energy Transfer in Scattering by Rotating Potentials

Indian Academy of Sciences (India)

Quantum mechanical scattering theory is studied for time-dependent Schrödinger operators, in particular for particles in a rotating potential. Under various assumptions about the decay rate at infinity we show uniform boundedness in time for the kinetic energy of scattering states, existence and completeness of wave ...

Demonstration of pumping efficiency for rotating disks by Monte Carlo simulation

International Nuclear Information System (INIS)

Ogiwara, Norio

2010-01-01

We investigated the concept of creating a gas radial flow by employing the molecular drag effect upon gas molecules on rotating disks. All the gas molecules have a circumferential velocity rω (r: distance from the rotating axis, and ω: angular velocity) each time they leave a surface of the rotating disks. As a result, the gas molecules between the rotating disks tend on average to move outward from the center. That is, a radial flow appears. This idea was demonstrated by Monte Carlo simulation of 2 types of rotating disks (flat and corrugated ones). Pumping efficiency was clearly demonstrated for both types of disks when the velocity ratio rω/ ( : mean velocity) became larger than 1. (author)

Polarity and Nonpolarity of Ionic Liquids Viewed from the Rotational Dynamics of Carbon Monoxide.

Science.gov (United States)

Yasaka, Y; Kimura, Y

2015-12-17

The rotational dynamics of carbon monoxide (CO) in a molten salt, ionic liquids (ILs), and alkanes were investigated by (17)O NMR T1 measurements using labeled C(17)O. The molten salt and the studied ILs have the bis(trifluoromethanesulfonyl)imide anion ([NTf2](-)) in common. In hexane near room temperature, the rotational relaxation times are close to the values predicted from the slip boundary condition in the Stokes-Einstein-Debye (SED) theory. However, in contradiction to the theoretical prediction, the rotational relaxation times decrease as the value of η/T increases, where η and T are the viscosity and absolute temperature, respectively. In other alkanes and ILs used in this study, the rotational relaxation times are much faster than those predicted by SED, and show a unique dependence on the number of alkyl carbons. For the same value of η/T, the CO rotational relaxation times in ILs composed of short-alkyl-chain-length imidazolium cations (1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium) are close to those for a molten salt (Cs[NTf2]). On the other hand, the rotational relaxation times in ILs composed of long-chain-length imidazolium (1-methyl-3-octylimidazolium) and phosphonium (tributylmethylphosphonium and tetraoctylphosphonium) cations are much shorter than the SED predictions. This deviation from theory increases as the alkyl chain length increases. We also found that the rotational relaxation times in dodecane and squalane are similar to those in ILs with a similar number of alkyl carbons. These results are discussed in terms of heterogeneous solvation and in comparison with the translational diffusion of CO in ILs.

Age and Time Population Differences: Young Adults, Gen Xers, and Millennials

Science.gov (United States)

Menard, Lauren A.

2013-01-01

Age and Time disparities in young adult research populations are common because young adults are defined by varying age spans; members of Generation X and Millennial generations may both be considered young adults; study years vary, affecting populations; and qualitative methods with limited age/year samples are frequently utilized. The current…

Semiclassical description of quantum rotator in terms of SU(2) coherent states

International Nuclear Information System (INIS)

Gitman, D M; Petrusevich, D A; Shelepin, A L

2013-01-01

We introduce coordinates of the rigid body (rotator) using mutual positions between body-fixed and space-fixed reference frames. Wave functions that depend on such coordinates can be treated as scalar functions of the group SU(2). Irreducible representations of the group SU(2) × SU(2) in the space of such functions describe their possible transformations under independent rotations of the both reference frames. We construct sets of the corresponding group SU(2) × SU(2) Perelomov coherent states (CS) with a fixed angular momentum j of the rotator as special orbits of the latter group. Minimization of different uncertainty relations is discussed. The classical limit corresponds to the limit j → ∞. Considering Hamiltonians of rotators with different characteristics, we study the time evolution of the constructed CS. In some cases, the CS time evolution is completely or partially reduced to their parameter time evolution. If these parameters are chosen as Euler angles, then they obey the Euler equations in the classical limit. Quantum corrections to the motion of the quantum rotator can be found from exact equations on the CS parameters. (paper)

α+12C rotational bands in 16O

Directory of Open Access Journals (Sweden)

Katsuma M.

2014-03-01

Full Text Available The total quantum number N of the α+12C rotational bands in 16O is determined by a study of α+12C elastic scattering. The 8+ and 9− states are found around the excitation energy Ex = 30 MeV and they are the member of the known rotational bands. At the same time, the 02+ state (Ex = 6.05 MeV is found to be dominated by N = 8.

The relationship between quality of sleep and night shift rotation interval.

Science.gov (United States)

Kim, Jae Youn; Chae, Chang Ho; Kim, Young Ouk; Son, Jun Seok; Kim, Ja Hyun; Kim, Chan Woo; Park, Hyoung Ouk; Lee, Jun Ho; Kwon, Soon Il; Kwon, Sun Il

2015-01-01

Shift work is closely related with workers' health. In particular, sleep is thought to be affected by shift work. In addition, shift work has been reported to be associated with the type or direction of shift rotation, number of consecutive night shifts, and number of off-duty days. We aimed to analyze the association between the night shift rotation interval and the quality of sleep reported by Korean female shift workers. In total, 2,818 female shift workers from the manufacturing industry who received an employee physical examination at a single university hospital from January to August in 2014 were included. Subjects were classified into three groups (A, B, and C) by their night shift rotation interval. The quality of sleep was measured using the Korean version of the Pittsburgh Sleep Quality Index (PSQI). Descriptive analysis, univariate logistic regression, and multivariate logistic regression were performed. With group A as the reference, the odds ratio (OR) for having a seriously low quality of sleep was 1.456 (95% CI 1.171-1.811) and 2.348 (95% CI 1.852-2.977) for groups B and C, respectively. Thus, group C with the shortest night shift rotation interval was most likely to have a low quality of sleep. After adjustment for age, obesity, smoking status, alcohol consumption, exercise, being allowed to sleep during night shifts, work experience, and shift work experience, groups B and C had ORs of 1.419 (95% CI 1.134-1.777) and 2.238 (95% CI 1.737-2.882), respectively, compared to group A. Our data suggest that a shorter night shift rotation interval does not provide enough recovery time to adjust the circadian rhythm, resulting in a low quality of sleep. Because shift work is influenced by many different factors, future studies should aim to determine the most optimal shift work model and collect accurate, prospective data.

Rotational motion in nuclei

International Nuclear Information System (INIS)

Bohr, A.

1977-01-01

History is surveyed of the development of the theory of rotational states in nuclei. The situation in the 40's when ideas formed of the collective states of a nucleus is evoked. The general rotation theory and the relation between the single-particle and rotational motion are briefly discussed. Future prospects of the rotation theory development are indicated. (I.W.)

Rotations with Rodrigues' vector

International Nuclear Information System (INIS)

Pina, E

2011-01-01

The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears to be a fundamental matrix that is used to express the components of the angular velocity, the rotation matrix and the angular momentum vector. The Hamiltonian formalism of rotational dynamics in terms of this vector uses the same matrix. The quantization of the rotational dynamics is performed with simple rules if one uses Rodrigues' vector and similar formal expressions for the quantum operators that mimic the Hamiltonian classical dynamics.

Effect of rotation on convective mass transfer in rotating channels

International Nuclear Information System (INIS)

Pharoah, J.G.; Djilali, N.

2002-01-01

Laminar flow and mass transfer in rotating channels is investigated in the context of centrifugal membrane separation. The effect of orientation with respect to the rotational axis is examined for rectangular channels of aspect ratio 3 and the Rossby number is varied from 0.3 to 20.9. Both Ro and the channel orientation are found to have a significant effect on the flow. Mass transfer calculations corresponding to reverse osmosis desalination are carried out at various operating pressures and all rotating cases exhibit significant process enhancements at relatively low rotation rates. Finally, while it is common in the membrane literature to correlate mass transfer performance with membrane shear rates this is shown not to be valid in the cases presented herein. (author)

WHY ARE RAPIDLY ROTATING M DWARFS IN THE PLEIADES SO (INFRA)RED? NEW PERIOD MEASUREMENTS CONFIRM ROTATION-DEPENDENT COLOR OFFSETS FROM THE CLUSTER SEQUENCE

Energy Technology Data Exchange (ETDEWEB)

Covey, Kevin R. [Department of Physics and Astronomy, Western Washington University, Bellingham WA 98225-9164 (United States); Agüeros, Marcel A.; Liu, Jiyu [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Ahmadi, Aida [Max Planck Institute for Radioastronomy, Auf dem Hügel 69, D-53121 Bonn (Germany); Laher, Russ; Surace, Jason [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Levitan, David [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Sesar, Branimir, E-mail: kevin.covey@wwu.edu [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

2016-05-10

Stellar rotation periods ( P {sub rot}) measured in open clusters have proved to be extremely useful for studying stars’ angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While P {sub rot} measurements have been obtained for hundreds of solar-mass members of the Pleiades, measurements exist for only a few low-mass (<0.5 M {sub ⊙}) members of this key laboratory for stellar evolution theory. To fill this gap, we report P {sub rot} for 132 low-mass Pleiades members (including nearly 100 with M ≤ 0.45 M {sub ⊙}), measured from photometric monitoring of the cluster conducted by the Palomar Transient Factory in late 2011 and early 2012. These periods extend the portrait of stellar rotation at 125 Myr to the lowest-mass stars and re-establish the Pleiades as a key benchmark for models of the transport and evolution of stellar angular momentum. Combining our new P {sub rot} with precise BVIJHK photometry reported by Stauffer et al. and Kamai et al., we investigate known anomalies in the photometric properties of K and M Pleiades members. We confirm the correlation detected by Kamai et al. between a star's P {sub rot} and position relative to the main sequence in the cluster's color–magnitude diagram. We find that rapid rotators have redder ( V − K ) colors than slower rotators at the same V , indicating that rapid and slow rotators have different binary frequencies and/or photospheric properties. We find no difference in the photometric amplitudes of rapid and slow rotators, indicating that asymmetries in the longitudinal distribution of starspots do not scale grossly with rotation rate.

Preoperative and post-operative sleep quality evaluation in rotator cuff tear patients.

Science.gov (United States)

Serbest, Sancar; Tiftikçi, Uğur; Askın, Aydogan; Yaman, Ferda; Alpua, Murat

2017-07-01

The aim of this study was to examine the potential relationship between subjective sleep quality and degree of pain in patients with rotator cuff repair. Thirty-one patients who underwent rotator cuff repair prospectively completed the Pittsburgh Sleep Quality Index, the Western Ontario Rotator Cuff Index, and the Constant and Murley shoulder scores before surgery and at 6 months after surgery. Preoperative demographic, clinical, and radiologic parameters were also evaluated. The study analysed 31 patients with a median age of 61 years. There was a significant difference preoperatively versus post-operatively in terms of all PSQI global scores and subdivisions (p Rotator Cuff Scale and the Constant and Murley shoulder scores (p ˂ 0.001). Sleep disorders are commonly seen in patients with rotator cuff tear, and after repair, there is an increase in the quality of sleep with a parallel improvement in shoulder functions. However, no statistically significant correlation was determined between arthroscopic procedures and the size of the tear and sleep quality. It is suggested that rotator cuff tear repair improves the quality of sleep and the quality of life. IV.

Gout Can Increase the Risk of Receiving Rotator Cuff Tear Repair Surgery.

Science.gov (United States)

Huang, Shih-Wei; Wu, Chin-Wen; Lin, Li-Fong; Liou, Tsan-Hon; Lin, Hui-Wen

2017-08-01

Gout commonly involves joint inflammation, and clinical epidemiological studies on involved tendons are scant. Rotator cuff tears are the most common cause of shoulder disability, and surgery is one of the choices often adopted to regain previous function. To investigate the risk of receiving rotator cuff repair surgery among patients with gout and to analyze possible risk factors to design an effective prevention strategy. Cohort study; Level of evidence, 3. The authors studied a 7-year longitudinal follow-up of patients from the Taiwan Longitudinal Health Insurance Database 2005 (LHID2005). This included a cohort of patients who received a diagnosis of gout during 2004-2008 (gout cohort) and a cohort matched by propensity scores (control cohort). A 2-stage approach that used the National Health Interview Survey 2005 was used to obtain missing confounding variables from the LHID2005. The crude hazard ratio (HR) and adjusted HR were estimated between the gout and control cohorts. The gout and control cohorts comprised 32,723 patients with gout and 65,446 people matched at a ratio of 1:2. The incidence of rotator cuff repair was 31 and 18 per 100,000 person-years in the gout and control cohorts, respectively. The crude HR for rotator cuff repair in the gout cohort was 1.73 (95% confidence interval [CI], 1.23-2.44; P gout cohort. Further analysis revealed that the adjusted HR was 1.73 (95% CI, 1.20-2.50; P gout who did not take hypouricemic medication and 2.70 (95% CI, 1.31-5.59; P gout aged 50 years or younger. Patients with gout, particularly those aged 50 years or younger and without hypouricemic medication control, are at a relatively higher risk of receiving rotator cuff repair surgery. Strict control of uric acid levels with hypouricemic medication may effectively reduce the risk of rotator cuff repair.

Hemispheric dominance during the mental rotation task in patients with schizophrenia.

Science.gov (United States)

Chen, Jiu; Yang, Laiqi; Zhao, Jin; Li, Lanlan; Liu, Guangxiong; Ma, Wentao; Zhang, Yan; Wu, Xingqu; Deng, Zihe; Tuo, Ran

2012-04-01

Mental rotation is a spatial representation conversion capability using an imagined object and either object or self-rotation. This capability is impaired in schizophrenia. To provide a more detailed assessment of impaired cognitive functioning in schizophrenia by comparing the electrophysiological profiles of patients with schizophrenia and controls while completing a mental rotation task using both normally-oriented images and mirror images. This electroencephalographic study compared error rates, reaction times and the topographic map of event-related potentials in 32 participants with schizophrenia and 29 healthy controls during mental rotation tasks involving both normal images and mirror images. Among controls the mean error rate and the mean reaction time for normal images and mirror images were not significantly different but in the patient group the mean (sd) error rate was higher for mirror images than for normal images (42% [6%] vs. 32% [9%], t=2.64, p=0.031) and the mean reaction time was longer for mirror images than for normal images (587 [11] ms vs. 571 [18] ms, t=2.83, p=0.028). The amplitude of the P500 component at Pz (parietal area), Cz (central area), P3 (left parietal area) and P4 (right parietal area) were significantly lower in the patient group than in the control group for both normal images and mirror images. In both groups the P500 for both the normal and mirror images was significantly higher in the right parietal area (P4) compared with left parietal area (P3). The mental rotation abilities of patients with schizophrenia for both normally-oriented images and mirror images are impaired. Patients with schizophrenia show a diminished left cerebral contribution to the mental rotation task, a more rapid response time, and a differential response to normal images versus mirror images not seen in healthy controls. Specific topographic characteristics of the EEG during mental rotation tasks are potential biomarkers for schizophrenia.

Power dependence on the rotational strength in a quartz crystal

International Nuclear Information System (INIS)

Joshi, N.V.; Salcedo, D.; Gil, H.

2007-01-01

The rotational strength of optical activity has been examined as a function of power of the incident radiation in a quartz crystal for the first time. It has been observed that the angle of rotation is proportional to the square root of the intensity of the radiation. The present experimental data directly support the recently proposed model which takes into account the electronic polarizability rather than the atomic polarizability. This model explicitly explains the role of the incident power in estimating the angle of rotation

Stationary strings near a higher-dimensional rotating black hole

International Nuclear Information System (INIS)

Frolov, Valeri P.; Stevens, Kory A.

2004-01-01

We study stationary string configurations in a space-time of a higher-dimensional rotating black hole. We demonstrate that the Nambu-Goto equations for a stationary string in the 5D (five-dimensional) Myers-Perry metric allow a separation of variables. We present these equations in the first-order form and study their properties. We prove that the only stationary string configuration that crosses the infinite redshift surface and remains regular there is a principal Killing string. A worldsheet of such a string is generated by a principal null geodesic and a timelike at infinity Killing vector field. We obtain principal Killing string solutions in the Myers-Perry metrics with an arbitrary number of dimensions. It is shown that due to the interaction of a string with a rotating black hole, there is an angular momentum transfer from the black hole to the string. We calculate the rate of this transfer in a space-time with an arbitrary number of dimensions. This effect slows down the rotation of the black hole. We discuss possible final stationary configurations of a rotating black hole interacting with a string

A Numerical-Analytical Approach to Modeling the Axial Rotation of the Earth

Science.gov (United States)

Markov, Yu. G.; Perepelkin, V. V.; Rykhlova, L. V.; Filippova, A. S.

2018-04-01

A model for the non-uniform axial rotation of the Earth is studied using a celestial-mechanical approach and numerical simulations. The application of an approximate model containing a small number of parameters to predict variations of the axial rotation velocity of the Earth over short time intervals is justified. This approximate model is obtained by averaging variable parameters that are subject to small variations due to non-stationarity of the perturbing factors. The model is verified and compared with predictions over a long time interval published by the International Earth Rotation and Reference Systems Service (IERS).

MRS2016: Rigid Moon Rotation Series in the Relativistic Approximation

Science.gov (United States)

Pashkevich, V. V.

2017-03-01

The rigid Moon rotation problem is studied for the relativistic (kinematical) case, in which the geodetic perturbations in the Moon rotation are taken into account. As the result of this research the high-precision Moon Rotation Series MRS2016 in the relativistic approximation was constructed for the first time and the discrepancies between the high-precision numerical and the semi-analytical solutions of the rigid Moon rotation were investigated with respect to the fixed ecliptic of epoch J2000, by the numerical and analytical methods. The residuals between the numerical solution and MRS2016 in the perturbing terms of the physical librations do not exceed 80 mas and 10 arc seconds over 2000 and 6000 years, respectively.

Rotated alphanumeric characters do not automatically activate frontoparietal areas subserving mental rotation

DEFF Research Database (Denmark)

Weiss, Michael M; Wolbers, Thomas; Peller, Martin

2008-01-01

Functional neuroimaging studies have identified a set of areas in the intraparietal sulcus and dorsal precentral cortex which show a linear increase in activity with the angle of rotation across a variety of mental rotation tasks. This linear increase in activity with angular disparity suggests t...... modulated by angular disparity during the stimulus categorization task. These results suggest that at least for alphanumerical characters, areas implicated in mental rotation will only be called into action if the task requires a rotational transformation....

Determination of the axial rotation rate using apsidal motion for early-type eclipsing binaries

Science.gov (United States)

Khaliullin, Kh. F.; Khaliullina, A. I.

2007-11-01

Because the modern theory of stellar structure and evolution has a sound observational basis, we can consider that the apsidal parameters k2 computed in terms of this theory correctly reflect the radial density distribution in stars of different masses and spectral types. This allows us to address the problem of apsidal motion in close binary systems in a new way. Unlike the traditional approach, in this paper we use the observed apsidal periods Uobs to estimate the angular axial velocities of components, ωr, at fixed model values of k2. We use this approach to analyse the observational data for 28 eclipsing systems with known Uobs and early-type primaries (M >= 1.6 Msolar or Te >= 6000 K). We measure the age of the system in units of the synchronization time, t/tsyn. Our analysis yielded the following results. (i) There is a clear correlation between ωr/ωsyn and t/tsyn: the younger a star, the higher the angular velocity of its axial rotation in units of ωsyn, the angular velocity at pseudo-synchronization. This correlation is more significant and obvious if the synchronization time, tsyn, is computed in terms of the Zahn theory. (ii) This observational fact implies that the synchronization of early-type components in close binary systems continues on the main sequence. The synchronization times for the inner layers of the components (i.e. those that are responsible for apsidal motion) are about 1.6 and 3.1 dex longer than those predicted by the theories of Zahn and Tassoul, respectively. The average initial angular velocities (for the zero-age main sequence) are equal to ω0/ωsyn ~ 2.0. The dependence of the parameter E2 on stellar mass probably needs to be refined in the Zahn theory. (iii) Some components of the eclipsing systems of the sample studied show radially differential axial rotation. This is consistent with the Zahn theory, which predicts that the synchronization starts at the surface, where radiative damping of dynamical tides occurs, and