Physical Limitations of Empirical Field Models: Force Balance and Plasma Pressure

International Nuclear Information System (INIS)

Sorin Zaharia; Cheng, C.Z.

2002-01-01

In this paper, we study whether the magnetic field of the T96 empirical model can be in force balance with an isotropic plasma pressure distribution. Using the field of T96, we obtain values for the pressure P by solving a Poisson-type equation (gradient) 2 P = (gradient) · (J x B) in the equatorial plane, and 1-D profiles on the Sun-Earth axis by integrating (gradient)P = J x B. We work in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials. Our results lead to the conclusion that the T96 model field cannot be in equilibrium with an isotropic pressure. We also analyze in detail the computation of Birkeland currents using the Vasyliunas relation and the T96 field, which yields unphysical results, again indicating the lack of force balance in the empirical model. The underlying reason for the force imbalance is likely the fact that the derivatives of the least-square fitted model B are not accurate predictions of the actual magnetospheric field derivatives. Finally, we discuss a possible solution to the problem of lack of force balance in empirical field models

Evaluation of the chondromalacia patella using a microscopy coil: comparison of the two-dimensional fast spin echo techniques and the three-dimensional fast field echo techniques.

Science.gov (United States)

Kim, Hyun-joo; Lee, Sang Hoon; Kang, Chang Ho; Ryu, Jeong Ah; Shin, Myung Jin; Cho, Kyung-Ja; Cho, Woo Shin

2011-01-01

We wanted to compare the two-dimensional (2D) fast spin echo (FSE) techniques and the three-dimensional (3D) fast field echo techniques for the evaluation of the chondromalacia patella using a microscopy coil. Twenty five patients who underwent total knee arthroplasty were included in this study. Preoperative MRI evaluation of the patella was performed using a microscopy coil (47 mm). The proton density-weighted fast spin echo images (PD), the fat-suppressed PD images (FS-PD), the intermediate weighted-fat suppressed fast spin echo images (iw-FS-FSE), the 3D balanced-fast field echo images (B-FFE), the 3D water selective cartilage scan (WATS-c) and the 3D water selective fluid scan (WATS-f) were obtained on a 1.5T MRI scanner. The patellar cartilage was evaluated in nine areas: the superior, middle and the inferior portions that were subdivided into the medial, central and lateral facets in a total of 215 areas. Employing the Noyes grading system, the MRI grade 0-I, II and III lesions were compared using the gross and microscopic findings. The sensitivity, specificity and accuracy were evaluated for each sequence. The significance of the differences for the individual sequences was calculated using the McNemar test. The gross and microscopic findings demonstrated 167 grade 0-I lesions, 40 grade II lesions and eight grade III lesions. Iw-FS-FSE had the highest accuracy (sensitivity/specificity/accuracy = 88%/98%/96%), followed by FS-PD (78%/98%/93%, respectively), PD (76%/98%/93%, respectively), B-FFE (71%/100%/93%, respectively), WATS-c (67%/100%/92%, respectively) and WATS-f (58%/99%/89%, respectively). There were statistically significant differences for the iw-FS-FSE and WATS-f and for the PD-FS and WATS-f (p chondromalacia patella.

The Association of Glaucomatous Visual Field Loss and Balance

Science.gov (United States)

de Luna, Regina A.; Mihailovic, Aleksandra; Nguyen, Angeline M.; Friedman, David S.; Gitlin, Laura N.; Ramulu, Pradeep Y.

2017-01-01

Purpose To relate balance measures to visual field (VF) damage from glaucoma. Methods The OPAL kinematic system measured balance, as root mean square (RMS) sway, on 236 patients with suspect/diagnosed glaucoma. Balance was measured with feet shoulder width apart while standing on a firm/foam surface with eyes opened/closed (Instrumental Clinical Test of Sensory Integration and Balance [ICTSIB] conditions), and eyes open on a firm surface under feet together, semi-tandem, or tandem positions (standing balance conditions). Integrated VF (IVF) sensitivities were calculated by merging right and left eye 24-2 VF data. Results Mean age was 71 years (range, 57–93) and mean IVF sensitivity was 27.1 dB (normal = 31 dB). Lower IVF sensitivity was associated with greater RMS sway during eyes-open foam-surface testing (β = 0.23 z-score units/5 dB IVF sensitivity decrement, P = 0.001), but not during other ICTSIB conditions. Lower IVF sensitivity also was associated with greater RMS sway during feet together standing balance testing (0.10 z-score units/5 dB IVF sensitivity decrement, P = 0.049), but not during other standing balance conditions. Visual dependence of balance was lower in patients with worse IVF sensitivity (β = −21%/5 dB IVF sensitivity decrement, P falls and patients with VF loss from glaucoma may be at higher risk of falls because of poor balance. PMID:28553562

The IAEA Activities in the Field of Fast Reactors Technology Development

International Nuclear Information System (INIS)

Monti, Stefano

2011-01-01

Main activities of the IAEA Programme on Fast Reactor: Carry out Collaborative Research Projects (CRPs) of common interest to the TWG-FR Member States in the field of FRs and ADS; Secure Training and Education in the field of fast neutron system physics, technology and applications; Support Fast Reactor data retrieval and knowledge preservation activities in MSs; Provide support to IAEA Nuclear Safety and Security Department for preparation of fast reactor Safety standards / requirements / guides. IAEA TWG-FR Functions: Provide advice and guidance, and marshal support in their countries for implementation of IAEA’s programmatic activities in the area of advanced technologies and R&D for fast reactors and sub-critical hybrid systems for energy production and for utilization/transmutation of long-lived nuclides; Provide a forum for information and knowledge sharing on national and international development programs; Act as a link between IAEA’s activities in the specific area of the TWG-FR and national scientific communities, delivering information from and to national communities

Geosynchronous magnetic field responses to fast solar wind dynamic pressure enhancements: MHD field model

Directory of Open Access Journals (Sweden)

T. R. Sun

2012-08-01

Full Text Available We performed global MHD simulations of the geosynchronous magnetic field in response to fast solar wind dynamic pressure (Pd enhancements. Taking three Pd enhancement events in 2000 as examples, we found that the main features of the total field B and the dominant component Bz can be efficiently predicted by the MHD model. The predicted B and Bz varies with local time, with the highest level near noon and a slightly lower level around mid-night. However, it is more challenging to accurately predict the responses of the smaller component at the geosynchronous orbit (i.e., Bx and By. In contrast, the limitations of T01 model in predicting responses to fast Pd enhancements are presented.

On the parallel momentum balance in low pressure plasmas with an inhomogeneous magnetic field

International Nuclear Information System (INIS)

Smolyakov, A.I.; Garbet, X.; Bourdelle, C.

2009-01-01

This paper describes the structure of the parallel momentum balance in low pressure plasmas with an inhomogeneous magnetic field. The parallel momentum balance equation is derived from magnetohydrodynamic equations by an expansion in the inverse magnetic field 1/B as a small parameter. Contributions of the gyroviscosity and inertia terms are clarified. It is shown that magnetic field curvature leads to important coupling of parallel flow with fluctuations of the electric field and plasma pressure.

Simultaneous fast scanning XRF, dark field, phase-, and absorption contrast tomography

Science.gov (United States)

Medjoubi, Kadda; Bonissent, Alain; Leclercq, Nicolas; Langlois, Florent; Mercère, Pascal; Somogyi, Andrea

2013-09-01

Scanning hard X-ray nanoprobe imaging provides a unique tool for probing specimens with high sensitivity and large penetration depth. Moreover, the combination of complementary techniques such as X-ray fluorescence, absorption, phase contrast and dark field imaging gives complete quantitative information on the sample structure, composition and chemistry. The multi-technique "FLYSCAN" data acquisition scheme developed at Synchrotron SOLEIL permits to perform fast continuous scanning imaging and as such makes scanning tomography techniques feasible in a time-frame well-adapted to typical user experiments. Here we present the recent results of simultaneous fast scanning multi-technique tomography performed at Soleil. This fast scanning scheme will be implemented at the Nanoscopium beamline for large field of view 2D and 3D multimodal imaging.

Lifetime, turnover time, and fast magnetic field regeneration in random flows

International Nuclear Information System (INIS)

Tanner, S. E. M.

2007-01-01

The fast dynamo is thought to be relevant in the regeneration of magnetic fields in astrophysics where the value of the magnetic Reynolds number (Rm) is immense. The fast dynamo picture is one in which chaotic flows provide a mechanism for the stretching of magnetic field lines. Furthermore, a cascade of energy down to small scales results in intermittent regions of a small-scale, intense magnetic field. Given this scenario it is natural to invoke the use of kinematic random flows in order to understand field regeneration mechanisms better. Here a family of random flows is used to study the effects that L, the lifetime of the cell, and τ, the turnover time of the cell, may have on magnetic field regeneration. Defining the parameter Γ=L/τ, it has been varied according to Γ>1, Γ<1, Γ∼O(1). In the kinematic regime, dynamo growth rates and Lyapunov exponents are examined at varying values of Rm. The possibility of fast dynamo action is considered. In the nonlinear regime, magnetic and kinetic energies are examined. Results indicate that there does appear to be a relationship between Γ and dynamo efficiency. In particular, the most efficient dynamos seem to operate at lower values of Γ

Commission of the European Communities - Activities in the field of fast reactors

International Nuclear Information System (INIS)

Balz, W.

1977-01-01

The Commission of the European Communities is performing activities in the field of fast reactor on two lines: a) activities aiming to prepare the commercialization of fast reactors by coordination and collaboration between national programmes. b) the execution of an own programme in the Joint Research Centre at Ispra (Italy) and Karlsruhe (Federal Republic of Germany) in the field of FBR safety and research on Pu-bearing fuel

How to use the Fast Fourier Transform in Large Finite Fields

OpenAIRE

Petersen, Petur Birgir

2011-01-01

The article contents suggestions on how to perform the Fast Fourier Transform over Large Finite Fields. The technique is to use the fact that the multiplicative groups of specific prime fields are surprisingly composite.

Balancing of linkages and robot manipulators advanced methods with illustrative examples

CERN Document Server

Arakelian, Vigen

2015-01-01

In this book advanced balancing methods for planar and spatial linkages, hand operated and automatic robot manipulators are presented. It is organized into three main parts and eight chapters. The main parts are the introduction to balancing, the balancing of linkages and the balancing of robot manipulators. The review of state-of-the-art literature including more than 500 references discloses particularities of shaking force/moment balancing and gravity compensation methods. Then new methods for balancing of linkages are considered. Methods provided in the second part of the book deal with the partial and complete shaking force/moment balancing of various linkages. A new field for balancing methods applications is the design of mechanical systems for fast manipulation. Special attention is given to the shaking force/moment balancing of robot manipulators. Gravity balancing methods are also discussed. The suggested balancing methods are illustrated by numerous examples.

Neutral particle balance in GDT with fast titanium coating of the first wall

International Nuclear Information System (INIS)

Bagryansky, P.A.; Bender, E.D.; Ivanov, A.A.; Krahl, S.; Noack, K.; Karpushov, A.N.; Murakhtin, S.V.; Shikhovtsev, I.V.

1995-01-01

The GDT is an axisymmetric open trap with a high mirror ratio for confinement of a collisional plasma. The experimental program of the GDT was focused on the generation of plasma physics database necessary for a GDT-based neutron source. A distinct feature of both GDT and the GDT-based neutron source is that the Larmor radius of the fast sloshing ions is comparable to plasma radius. In this case, the sloshing ions can not be well shielded by the plasma halo from penetration of the neutral gas from periphery that results in high charge exchange losses. The plasma parameters are then very sensitive to gas pressure near the plasma boundary. To reduce the gas pressure to desured value during the beam heating, the authors have used arc-type evaporators developed at the Budker INP for fast titanium coating of the GDT first wall. If needed, the coating can be done a few seconds before each shot. They investigated the neutral particle balance in presence of NB-heating. The inverted magnetron gauges were used to study the temporal dependence of gas pressure inside the central cell. Pyroelectric bolometers were employed to measure the flux of charge exchange neutrals. Neutral particle balance has also been studied numerically by using a gas-transport code. The results of the investigations are the following: (1) sloshing ion lifetime was increased about 10 times compared to that without the coating of the first wall; and (2) wall recycling coefficient of the Ti-coated wall does not exceed 1 for 8 keV mean energy of the neutral hydrogen atoms striking the wall

Balancing the Interactions of Ions, Water, and DNA in the Drude Polarizable Force Field

OpenAIRE

Savelyev, Alexey; MacKerell, Alexander D.

2014-01-01

Recently we presented a first-generation all-atom Drude polarizable force field for DNA based on the classical Drude oscillator model, focusing on optimization of key dihedral angles followed by extensive validation of the force field parameters. Presently, we describe the procedure for balancing the electrostatic interactions between ions, water, and DNA as required for development of the Drude force field for DNA. The proper balance of these interactions is shown to impact DNA stability and...

Coupled force-balance and particle-occupation rate equations for high-field electron transport

International Nuclear Information System (INIS)

Lei, X. L.

2008-01-01

It is pointed out that in the framework of balance-equation approach, the coupled force-balance and particle-occupation rate equations can be used as a complete set of equations to determine the high-field transport of semiconductors in both strong and weak electron-electron interaction limits. We call to attention that the occupation rate equation conserves the total particle number and maintains the energy balance of the relative electron system, and there is no need to introduce any other term in it. The addition of an energy-drift term in the particle-occupation rate equation [Phys. Rev. B 71, 195205 (2005)] is physically inadequate for the violation of the total particle-number conservation and the energy balance. It may lead to a substantial unphysical increase of the total particle number by the application of a dc electric field

40 CFR 1065.295 - PM inertial balance for field-testing analysis.

Science.gov (United States)

2010-07-01

... net PM on a sample medium for field testing. (b) Component requirements. We recommend that you use a... 40 Protection of Environment 32 2010-07-01 2010-07-01 false PM inertial balance for field-testing analysis. 1065.295 Section 1065.295 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

Multistatic Array Sampling Scheme for Fast Near-Field Image Reconstruction

Science.gov (United States)

2016-01-01

human-sized scene in 0.048sec− 0.101sec. Index Terms—Microwave imaging, multistatic radar, Fast Fourier Transform (FFT). I. INTRODUCTION Near-field...configuration, but its computational demands are extreme. Fast Fourier Transform (FFT) imaging has long been used to efficiently construct images sampled...with the block diagram depicted in Fig. 4. It is noted that the multistatic to monostatic correction is valid over a finite imaging domain. However, as

Field evaluation of a fast anti-Leishmania antibody detection assay in Ethiopia

NARCIS (Netherlands)

Hailu, A.; Schoone, G. J.; Diro, E.; Tesfaye, A.; Techane, Y.; Tefera, T.; Assefa, Y.; Genetu, A.; Kebede, Y.; Kebede, T.; Schallig, H. D. F. H.

2006-01-01

A fast agglutination screening test (FAST) for the detection of Leishmania antibodies in human serum samples was evaluated under harsh field conditions in northern Ethiopia. Test performance was compared with a standard serological test, namely the direct agglutination test (DAT), and with

Activities of the OECD-NEA in the field of fast reactors

International Nuclear Information System (INIS)

Royen, J.

1977-01-01

The OECD-NEA is performing the following activities in the field of fast reactors: Held ad hoc meetings of senior experts on safety, development and economics of LMFBR type reactors; publishing a Nuclear Safety Research Index (the index is now expanded to cover fast reactors) and distribution; collect test computer programmes, as well as neutron data

The Field Assessment Stroke Triage for Emergency Destination (FAST-ED): a Simple and Accurate Pre-Hospital Scale to Detect Large Vessel Occlusion Strokes

Science.gov (United States)

Lima, Fabricio O.; Silva, Gisele S.; Furie, Karen L.; Frankel, Michael R.; Lev, Michael H.; Camargo, Érica CS; Haussen, Diogo C.; Singhal, Aneesh B.; Koroshetz, Walter J.; Smith, Wade S.; Nogueira, Raul G.

2016-01-01

Background and Purpose Patients with large vessel occlusion strokes (LVOS) may be better served by direct transfer to endovascular capable centers avoiding hazardous delays between primary and comprehensive stroke centers. However, accurate stroke field triage remains challenging. We aimed to develop a simple field scale to identify LVOS. Methods The FAST-ED scale was based on items of the NIHSS with higher predictive value for LVOS and tested in the STOPStroke cohort, in which patients underwent CT angiography within the first 24 hours of stroke onset. LVOS were defined by total occlusions involving the intracranial-ICA, MCA-M1, MCA-2, or basilar arteries. Patients with partial, bi-hemispheric, and/or anterior + posterior circulation occlusions were excluded. Receiver operating characteristic (ROC) curve, sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of FAST-ED were compared with the NIHSS, Rapid Arterial oCclusion Evaluation (RACE) scale and Cincinnati Prehospital Stroke Severity Scale (CPSSS). Results LVO was detected in 240 of the 727 qualifying patients (33%). FAST-ED had comparable accuracy to predict LVO to the NIHSS and higher accuracy than RACE and CPSS (area under the ROC curve: FAST-ED=0.81 as reference; NIHSS=0.80, p=0.28; RACE=0.77, p=0.02; and CPSS=0.75, p=0.002). A FAST-ED ≥4 had sensitivity of 0.60, specificity 0.89, PPV 0.72, and NPV 0.82 versus RACE ≥5 of 0.55, 0.87, 0.68, 0.79 and CPSS ≥2 of 0.56, 0.85, 0.65, 0.78, respectively. Conclusions FAST-ED is a simple scale that if successfully validated in the field may be used by medical emergency professionals to identify LVOS in the pre-hospital setting enabling rapid triage of patients. PMID:27364531

MR Imaging of the Internal Auditory Canal and Inner Ear at 3T: Comparison between 3D Driven Equilibrium and 3D Balanced Fast Field Echo Sequences

Energy Technology Data Exchange (ETDEWEB)

Byun, Jun Soo; Kim, Hyung Jin; Yim, Yoo Jeong; Kim, Sung Tae; Jeon, Pyoung; Kim, Keon Ha [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sam Soo; Jeon, Yong Hwan; Lee, Ji Won [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

2008-06-15

To compare the use of 3D driven equilibrium (DRIVE) imaging with 3D balanced fast field echo (bFFE) imaging in the assessment of the anatomic structures of the internal auditory canal (IAC) and inner ear at 3 Tesla (T). Thirty ears of 15 subjects (7 men and 8 women; age range, 22 71 years; average age, 50 years) without evidence of ear problems were examined on a whole-body 3T MR scanner with both 3D DRIVE and 3D bFFE sequences by using an 8-channel sensitivity encoding (SENSE) head coil. Two neuroradiologists reviewed both MR images with particular attention to the visibility of the anatomic structures, including four branches of the cranial nerves within the IAC, anatomic structures of the cochlea, vestibule, and three semicircular canals. Although both techniques provided images of relatively good quality, the 3D DRIVE sequence was somewhat superior to the 3D bFFE sequence. The discrepancies were more prominent for the basal turn of the cochlea, vestibule, and all semicircular canals, and were thought to be attributed to the presence of greater magnetic susceptibility artifacts inherent to gradient-echo techniques such as bFFE. Because of higher image quality and less susceptibility artifacts, we highly recommend the employment of 3D DRIVE imaging as the MR imaging choice for the IAC and inner ear

Axial distribution of absorbed doses in fast neutron field at the RB reactor

International Nuclear Information System (INIS)

Sokcic-Kostic, M.; Pesic, M.; Antic, D.; Ninkovic, M.

1988-11-01

The coupled fast thermal system CFTS at the RB reactor is created for obtaining fast neutron fields. The axial distribution of fast neutron flux density in its second configuration (CFTS-2) is measured. The axial distribution of absorbed doses is computed on the basis of mentioned experimental results. At the end these experimental and computed results are given. (Author)

Field Balancing in the Real World: Part 2

International Nuclear Information System (INIS)

Bracher, R.K.; Surrett, C.L.

1999-01-01

This paper is a follow-up to an earlier paper, Field Balancing in the Real World, which was presented at CSI Reliability Week 1997 in Nashville. Case studies of excessive vibrations on fans at ORNL will be discussed. Except for a few small sections from the earlier paper, this paper is entirely new. The case studies are new. As in the first paper, all fans are rigid-rotor type fans. Normal operation, therefore, is at less than the shaft's first critical speed. The presentation of case studies with root cause problems other than unbalance is a major departure from the first paper. We believe they belong here, since unbalance is suspected most of the time when a fan is vibrating excessively, even when it is not the root cause. In reality, unbalance is the underlying cause of the excess vibration on fans we have fixed at ORNL only about half the time. Furthermore, the analyst's credibility could be called into question upon an unsuccessful attempt at field balancing when underlying causes are later discovered and fixed. A demonstration will follow the case study presentation. The additional tests described in this paper to confirm centrifugal force (probable unbalance) will be performed

Fast static field CIPT mapping of unpatterned MRAM film stacks

DEFF Research Database (Denmark)

Kjær, Daniel; Hansen, Ole; Henrichsen, Henrik Hartmann

2015-01-01

Current In-Plane Tunneling (CIPT) method measures both RA and TMR, but the usefulness for uniformity mapping, e.g. for tool optimization, is limited by excessive measurement time. Thus, we develop and demonstrate a fast complementary static magnetic field method focused only on measurement of RA. We...... compare the static field method to the standard CIPT method and find perfect agreement between the extracted RA values and measurement repeatability while the static field method is several times faster. The static field CIPT method is demonstrated for 200 mm wafer mapping showing radial as well...

Adaptasi Fisiologis Selama Puasa (Physiological Adaptation During Fasting)

OpenAIRE

Fauziyati, Ana

2009-01-01

Fasting is an activity that has been done by people for long time. It is believed that fasting is good for health. During fasting people restrict food and water intake. How fasting makes body healthy and how body maintains the balance of energy and fluid during fasting are very interesting to learn. The objective of this review essay is to describe how the body maintain the balance of energy and fluid during fasting. During fasting, body lacks of food or energy intake, that means there is a r...

Maintaining balance when looking at a virtual reality three dimensional display of a field of moving dots or at a virtual reality scene

Directory of Open Access Journals (Sweden)

Elodie eChiarovano

2015-07-01

Full Text Available Experimental objective. To provide a safe, simple, relatively inexpensive, fast, accurate way of quantifying balance performance either in isolation, or in the face of challenges provided by 3D high definition moving visual stimuli as well as by the proprioceptive challenge from standing on a foam pad. This method uses the new technology of the Wii balance board to measure postural stability during powerful, realistic visual challenges from immersive virtual reality. Limitations of current techniques. Present computerized methods for measuring postural stability are large, complex, slow and expensive, and do not allow for testing the response to realistic visual challenges.Protocol. Subjects stand on a 6cm thick, firm, foam pad on a Wii balance board. They wear a fast, high resolution, low persistence, virtual reality head set (Oculus Rift DK2. This allows displays of varying speed, direction, depth and complexity to be delivered. The subject experiences a visual illusion of real objects fixed relative to the world, and any of these displays can be perturbed in an unpredictable fashion. A special app (Balance Rite used the same procedures for analysing postural analysis as used by the Equitest.Power of the technique. Four simple proof of concept experiments demonstrate that this technique matches the gold standard Equitest in terms of the measurement of postural stability but goes beyond the Equitest by measuring stability in the face of visual challenges, which are so powerful that even healthy subjects fall. The response to these challenges presents an opportunity for predicting falls and for rehabilitation of seniors and patients with poor postural stability.Significance for the field. This new method provides a simpler, quicker, cheaper method of measurement than the Equitest. It may provide a new mode of training to prevent falls, by maintaining postural stability in the face of visual and proprioceptive challenges similar to those

Detailed balance condition and ultraviolet stability of scalar field in Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Borzou, Ahmad; Lin, Kai; Wang, Anzhong

2011-01-01

Detailed balance and projectability conditions are two main assumptions when Horava recently formulated his theory of quantum gravity - the Horava-Lifshitz (HL) theory. While the latter represents an important ingredient, the former often believed needs to be abandoned, in order to obtain an ultraviolet stable scalar field, among other things. In this paper, because of several attractive features of this condition, we revisit it, and show that the scalar field can be stabilized, if the detailed balance condition is allowed to be softly broken. Although this is done explicitly in the non-relativistic general covariant setup of Horava-Melby-Thompson with an arbitrary coupling constant λ, generalized lately by da Silva, it is also true in other versions of the HL theory. With the detailed balance condition softly breaking, the number of independent coupling constants can be still significantly reduced. It is remarkable to note that, unlike other setups, in this da Silva generalization, there exists a master equation for the linear perturbations of the scalar field in the flat Friedmann-Robertson-Walker background

Cloud-based calculators for fast and reliable access to NOAA's geomagnetic field models

Science.gov (United States)

Woods, A.; Nair, M. C.; Boneh, N.; Chulliat, A.

2017-12-01

While the Global Positioning System (GPS) provides accurate point locations, it does not provide pointing directions. Therefore, the absolute directional information provided by the Earth's magnetic field is of primary importance for navigation and for the pointing of technical devices such as aircrafts, satellites and lately, mobile phones. The major magnetic sources that affect compass-based navigation are the Earth's core, its magnetized crust and the electric currents in the ionosphere and magnetosphere. NOAA/CIRES Geomagnetism (ngdc.noaa.gov/geomag/) group develops and distributes models that describe all these important sources to aid navigation. Our geomagnetic models are used in variety of platforms including airplanes, ships, submarines and smartphones. While the magnetic field from Earth's core can be described in relatively fewer parameters and is suitable for offline computation, the magnetic sources from Earth's crust, ionosphere and magnetosphere require either significant computational resources or real-time capabilities and are not suitable for offline calculation. This is especially important for small navigational devices or embedded systems, where computational resources are limited. Recognizing the need for a fast and reliable access to our geomagnetic field models, we developed cloud-based application program interfaces (APIs) for NOAA's ionospheric and magnetospheric magnetic field models. In this paper we will describe the need for reliable magnetic calculators, the challenges faced in running geomagnetic field models in the cloud in real-time and the feedback from our user community. We discuss lessons learned harvesting and validating the data which powers our cloud services, as well as our strategies for maintaining near real-time service, including load-balancing, real-time monitoring, and instance cloning. We will also briefly talk about the progress we achieved on NOAA's Big Earth Data Initiative (BEDI) funded project to develop API

Fast ion loss and radial electric field in high-aspect-ratio stellarator

International Nuclear Information System (INIS)

Itoh, Kimitaka; Sanuki, Heiji; Itoh, Sanae

1992-01-01

Theoretical model is developed to determine the radial electric field and the fast ion loss simultaneously in stellarators, and is applied to the Wendelstein VII-A stellarator. The predicted value of the radial electric field is more close to experiments than the purely neoclassical calculation. The loss rate, which is determined simultaneously, is in the range of experimental observations. The partition of the injection energy by the bulk heating, direct orbit loss and shine through is estimated by using the selfconsistent electric field profile. The orbit loss becomes noticeable as the injection energy increases. The influence of the neutral particles is also studied. Neutral particles enhance the negative radial electric field, and reduce the direct orbit loss by the expense of the charge exchange loss. The impact of the increased radial electric field on the neoclassical ion thermal energy loss is compared to the direct loss of fast ions. The reduction of the neoclassical loss is much smaller than the orbit loss. (author)

Fast ion loss and radial electric field in Wendelstein VII-Λ stellarator

International Nuclear Information System (INIS)

Itoh, K.; Sanuki, H.; Itoh, S.

1991-10-01

Theoretical model is developed to determine the radial electric field and the fast ion loss simultaneously in stellarators, and is applied to the Wendelstein VII-A stellarator. The predicted value of the radial electric field is more closer to experiments than the purely neoclassical calculation. The loss rate, which is determined simultaneously, is in the range of experimental observations. The partition of the injection energy by the bulk heating, direct orbit loss and shine through is estimated by using the self consistent electric field profile. The orbit loss become noticeable as the injection energy increases. The influence of the neutral particles is also studied. Neutral particles enhances the negative radial electric field, and reduces the direct orbit loss by the expense of the charge exchange loss. The impact of the increased radial electric field on the neoclassical ion thermal energy loss is compared to the direct loss of fast ions. The reduction of the neoclassical loss is much smaller than the orbit loss. (author)

Effects of a longitudinal magnetic field on current pulses and fast ionization-wave structure

International Nuclear Information System (INIS)

Asinovskii, E.I.; Lagar'kov, A.N.; Markovets, V.V.; Rutkevich, I.M.; Ul'yanov, A.M.; Filyugin, I.V.

1988-01-01

A longitudinal magnetic field affects the fast ionization-wave structure in a discharge tube surrounded by a metal screen. The field does not alter the wave speed, but the current amplitude is increased. This is explained from a theory for fast-wave propagation in a cylindrical guide containing an axial field. Numerical solutions have been obtained for the stationary nonlinear waves, which are compared with measurements. A theoretical study has been made on the ionization-wave features for large values of the Hall parameter

Fast Advection of Magnetic Fields by Hot Electrons

International Nuclear Information System (INIS)

Willingale, L.; Thomas, A. G. R.; Krushelnick, K.; Nilson, P. M.; Kaluza, M. C.; Dangor, A. E.; Evans, R. G.; Fernandes, P.; Haines, M. G.; Kamperidis, C.; Kingham, R. J.; Ridgers, C. P.; Sherlock, M.; Wei, M. S.; Najmudin, Z.; Bandyopadhyay, S.; Notley, M.; Minardi, S.; Tatarakis, M.; Rozmus, W.

2010-01-01

Experiments where a laser-generated proton beam is used to probe the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target are presented. At intensities of 10 15 W cm -2 and under conditions of significant fast electron production and strong heat fluxes, the electron mean-free-path is long compared with the temperature gradient scale length and hence nonlocal transport is important for the dynamics of the magnetic field in the plasma. The hot electron flux transports self-generated magnetic fields away from the focal region through the Nernst effect [A. Nishiguchi et al., Phys. Rev. Lett. 53, 262 (1984)] at significantly higher velocities than the fluid velocity. Two-dimensional implicit Vlasov-Fokker-Planck modeling shows that the Nernst effect allows advection and self-generation transports magnetic fields at significantly faster than the ion fluid velocity, v N /c s ≅10.

Evaluation of the Chondromalacia Patella Using a Microscopy Coil: Comparison of the Two-Dimensional Fast Spin Echo Techniques and the Three-Dimensional Fast Field Echo Techniques

International Nuclear Information System (INIS)

Kim, Hyun Joo; Lee, Sang Hoon; Kang, Chang Ho; Ryu, Jeong Ah; Shin, Myung Jin; Cho, Kyung Ja; Cho, Woo Shin

2011-01-01

We wanted to compare the two-dimensional (2D) fast spin echo (FSE) techniques and the three-dimensional (3D) fast field echo techniques for the evaluation of the chondromalacia patella using a microscopy coil. Twenty five patients who underwent total knee arthroplasty were included in this study. Preoperative MRI evaluation of the patella was performed using a microscopy coil (47 mm). The proton density-weighted fast spin echo images (PD), the fat-suppressed PD images (FS-PD), the intermediate weighted-fat suppressed fast spin echo images (iw-FS-FSE), the 3D balanced-fast fi eld echo images (B-FFE), the 3D water selective cartilage scan (WATS-c) and the 3D water selective fluid scan (WATS-f) were obtained on a 1.5T MRI scanner. The patellar cartilage was evaluated in nine areas: the superior, middle and the inferior portions that were subdivided into the medial, central and lateral facets in a total of 215 areas. Employing the Noyes grading system, the MRI grade 0-I, II and III lesions were compared using the gross and microscopic findings. The sensitivity, specificity and accuracy were evaluated for each sequence. The significance of the differences for the individual sequences was calculated using the McNemar test. The gross and microscopic findings demonstrated 167 grade 0-I lesions, 40 grade II lesions and eight grade III lesions. Iw-FS-FSE had the highest accuracy (sensitivity/specificity/accuracy = 88%/98%/96%), followed by FSPD (78%/98%/93%, respectively), PD (76%/98%/93%, respectively), B-FFE (71%/100%/93%, respectively), WATS-c (67%/100%/92%, respectively) and WATS-f (58%/99%/89%, respectively). There were statistically significant differences for the iw-FS-FSE and WATS-f and for the PD-FS and WATS-f (p < 0.01). The iw-FS-FSE images obtained with a microscopy coil show best diagnostic performance among the 2D and 3D GRE images for evaluating the chondromalacia patella

Evaluation of the Chondromalacia Patella Using a Microscopy Coil: Comparison of the Two-Dimensional Fast Spin Echo Techniques and the Three-Dimensional Fast Field Echo Techniques

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Joo; Lee, Sang Hoon; Kang, Chang Ho; Ryu, Jeong Ah; Shin, Myung Jin; Cho, Kyung Ja; Cho, Woo Shin [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

2011-02-15

We wanted to compare the two-dimensional (2D) fast spin echo (FSE) techniques and the three-dimensional (3D) fast field echo techniques for the evaluation of the chondromalacia patella using a microscopy coil. Twenty five patients who underwent total knee arthroplasty were included in this study. Preoperative MRI evaluation of the patella was performed using a microscopy coil (47 mm). The proton density-weighted fast spin echo images (PD), the fat-suppressed PD images (FS-PD), the intermediate weighted-fat suppressed fast spin echo images (iw-FS-FSE), the 3D balanced-fast fi eld echo images (B-FFE), the 3D water selective cartilage scan (WATS-c) and the 3D water selective fluid scan (WATS-f) were obtained on a 1.5T MRI scanner. The patellar cartilage was evaluated in nine areas: the superior, middle and the inferior portions that were subdivided into the medial, central and lateral facets in a total of 215 areas. Employing the Noyes grading system, the MRI grade 0-I, II and III lesions were compared using the gross and microscopic findings. The sensitivity, specificity and accuracy were evaluated for each sequence. The significance of the differences for the individual sequences was calculated using the McNemar test. The gross and microscopic findings demonstrated 167 grade 0-I lesions, 40 grade II lesions and eight grade III lesions. Iw-FS-FSE had the highest accuracy (sensitivity/specificity/accuracy = 88%/98%/96%), followed by FSPD (78%/98%/93%, respectively), PD (76%/98%/93%, respectively), B-FFE (71%/100%/93%, respectively), WATS-c (67%/100%/92%, respectively) and WATS-f (58%/99%/89%, respectively). There were statistically significant differences for the iw-FS-FSE and WATS-f and for the PD-FS and WATS-f (p < 0.01). The iw-FS-FSE images obtained with a microscopy coil show best diagnostic performance among the 2D and 3D GRE images for evaluating the chondromalacia patella

Neutron spectrum determination by activation method in fast neutron fields at the RB reactor

International Nuclear Information System (INIS)

Sokcic-Kostic, M.; Pesic, M.; Antic, D.

1994-01-01

The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (author)

Ionization signals from diamond detectors in fast-neutron fields

Energy Technology Data Exchange (ETDEWEB)

Weiss, C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); CIVIDEC Instrumentation, Wien (Austria); Frais-Koelbl, H. [University of Applied Sciences, Wiener Neustadt (Austria); Griesmayer, E.; Kavrigin, P. [CIVIDEC Instrumentation, Wien (Austria); Vienna University of Technology, Wien (Austria)

2016-09-15

In this paper we introduce a novel analysis technique for measurements with single-crystal chemical vapor deposition (sCVD) diamond detectors in fast-neutron fields. This method exploits the unique electronic property of sCVD diamond sensors that the signal shape of the detector current is directly proportional to the initial ionization profile. In fast-neutron fields the diamond sensor acts simultaneously as target and sensor. The interaction of neutrons with the stable isotopes {sup 12}C and {sup 13}C is of interest for fast-neutron diagnostics. The measured signal shapes of detector current pulses are used to identify individual types of interactions in the diamond with the goal to select neutron-induced reactions in the diamond and to suppress neutron-induced background reactions as well as γ-background. The method is verified with experimental data from a measurement in a 14.3 MeV neutron beam at JRC-IRMM, Geel/Belgium, where the {sup 13}C(n, α){sup 10}Be reaction was successfully extracted from the dominating background of recoil protons and γ-rays and the energy resolution of the {sup 12}C(n, α){sup 9}Be reaction was substantially improved. The presented analysis technique is especially relevant for diagnostics in harsh radiation environments, like fission and fusion reactors. It allows to extract the neutron spectrum from the background, and is particularly applicable to neutron flux monitoring and neutron spectroscopy. (orig.)

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

Science.gov (United States)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-06-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first field deployment of an iGrav superconducting gravimeter (SG) in a minimized enclosure for long-term integrative monitoring of water storage changes. Results of the field SG on a grassland site under wet-temperate climate conditions were compared to data provided by a nearby SG located in the controlled environment of an observatory building. The field system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily timescales. With about 99 and 85 % of the gravity signal due to local water storage changes originating within a radius of 4000 and 200 m around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field-monitoring technique at the landscape scale.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

Directory of Open Access Journals (Sweden)

A. Güntner

2017-06-01

Full Text Available In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first field deployment of an iGrav superconducting gravimeter (SG in a minimized enclosure for long-term integrative monitoring of water storage changes. Results of the field SG on a grassland site under wet–temperate climate conditions were compared to data provided by a nearby SG located in the controlled environment of an observatory building. The field system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings, and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily timescales. With about 99 and 85 % of the gravity signal due to local water storage changes originating within a radius of 4000 and 200 m around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field-monitoring technique at the landscape scale.

Emerging therapies for gait disability and balance impairment: promises and pitfalls.

Science.gov (United States)

Maetzler, Walter; Nieuwhof, Freek; Hasmann, Sandra E; Bloem, Bastiaan R

2013-09-15

Therapeutic management of gait and balance impairment during aging and neurodegeneration has long been a neglected topic. This has changed considerably during recent years, for several reasons: (1) an increasing recognition that gait and balance deficits are among the most relevant determinants of an impaired quality of life and increased mortality for affected individuals; (2) the arrival of new technology, which has allowed for new insights into the anatomy and functional (dis)integrity of gait and balance circuits; and (3) based in part on these improved insights, the development of new, more specific treatment strategies in the field of pharmacotherapy, deep brain surgery, and physiotherapy. The initial experience with these emerging treatments is encouraging, although much work remains to be done. The objective of this narrative review is to discuss several promising developments in the field of gait and balance treatment. We also address several pitfalls that can potentially hinder a fast and efficient continuation of this vital progress. Important issues that should be considered in future research include a clear differentiation between gait and balance as two distinctive targets for treatment and recognition of compensatory mechanisms as a separate target for therapeutic intervention. © 2013 Movement Disorder Society.

Neutron spectrum determination by activation method in fast neutron fields at the RB reactors

International Nuclear Information System (INIS)

Sokcic-Kostic, M.S.; Pesic, M.P.; Antic, D.P.

1994-01-01

The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (authors). 7 refs., 3 tabs

Fast-forward of quantum adiabatic dynamics in electro-magnetic field

OpenAIRE

Masuda, Shumpei; Nakamura, Katsuhiro

2010-01-01

We show a method to accelerate quantum adiabatic dynamics of wavefunctions under electro-magnetic field by developing the previous theory (Masuda & Nakamura 2008 and 2010). Firstly we investigate the orbital dynamics of a charged particle. We derive the driving field which accelerates quantum adiabatic dynamics in order to obtain the final adiabatic states except for the spatially uniform phase such as the adiabatic phase in any desired short time. Fast-forward of adiabatic squeezing and tran...

Self-field calculation of CICC with fast direct Biot–Savart integration

Energy Technology Data Exchange (ETDEWEB)

Wang, Xu; Li, Yingxu [Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou, Gansu 730000 (China); Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China); Gao, Yuanwen, E-mail: ywgao@lzu.edu.cn [Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou, Gansu 730000 (China); Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China); Zhou, Youhe [Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou, Gansu 730000 (China); Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China)

2014-04-15

Highlights: • An algorithm of fast direct Biot–Savart integration (FDBS) is proposed. • FDBS calculates the self-field of ITER cable-in-conduit conductor (CICC). • FDBS is more effective and easier to implement. • This new method will benefit future magnet design. - Abstract: ITER magnetic device (Tokamak) requires a strong magnetic field produced by charged cable conductors and external sources to arrive at stable and reliable magnetic confinement performance. Before manufacturing and assembling conductors, preliminary analysis of self-field induction is helpful for reducing the cost of varying-parameter experiments. Spatial helix shape of numerous strand elements and multi-level twist of the finalized cable, known as CICC type, make it unpractical to direct use finite-element methods and other numerical procedures for self-field calculation. An algorithm FDBS (fast direct Biot–Savart integration) is proposed to surmount this difficulty, which improves the traditional method (DBS, direct implementing Biot–Savart law for all strand sources) in terms of computational effort. As such the complexity reduces to O(N) from the original O(N{sup 2}) and speed enhancement is achieved in the parallel computation environment. FDBS calculates out a detailed self-field profile for the uncompressed ITER TF conductors carrying uniform current at each cabling level; the layered self-field distribution becomes more indistinct for higher level subcable.

Self-field calculation of CICC with fast direct Biot–Savart integration

International Nuclear Information System (INIS)

Wang, Xu; Li, Yingxu; Gao, Yuanwen; Zhou, Youhe

2014-01-01

Highlights: • An algorithm of fast direct Biot–Savart integration (FDBS) is proposed. • FDBS calculates the self-field of ITER cable-in-conduit conductor (CICC). • FDBS is more effective and easier to implement. • This new method will benefit future magnet design. - Abstract: ITER magnetic device (Tokamak) requires a strong magnetic field produced by charged cable conductors and external sources to arrive at stable and reliable magnetic confinement performance. Before manufacturing and assembling conductors, preliminary analysis of self-field induction is helpful for reducing the cost of varying-parameter experiments. Spatial helix shape of numerous strand elements and multi-level twist of the finalized cable, known as CICC type, make it unpractical to direct use finite-element methods and other numerical procedures for self-field calculation. An algorithm FDBS (fast direct Biot–Savart integration) is proposed to surmount this difficulty, which improves the traditional method (DBS, direct implementing Biot–Savart law for all strand sources) in terms of computational effort. As such the complexity reduces to O(N) from the original O(N 2 ) and speed enhancement is achieved in the parallel computation environment. FDBS calculates out a detailed self-field profile for the uncompressed ITER TF conductors carrying uniform current at each cabling level; the layered self-field distribution becomes more indistinct for higher level subcable

Response of six neutron survey meters in mixed fields of fast and thermal neutrons.

Science.gov (United States)

Kim, S I; Kim, B H; Chang, I; Lee, J I; Kim, J L; Pradhan, A S

2013-10-01

Calibration neutron fields have been developed at KAERI (Korea Atomic Energy Research Institute) to study the responses of commonly used neutron survey meters in the presence of fast neutrons of energy around 10 MeV. The neutron fields were produced by using neutrons from the (241)Am-Be sources held in a graphite pile and a DT neutron generator. The spectral details and the ambient dose equivalent rates of the calibration fields were established, and the responses of six neutron survey meters were evaluated. Four single-moderator-based survey meters exhibited an under-responses ranging from ∼9 to 55 %. DINEUTRUN, commonly used in fields around nuclear reactors, exhibited an over-response by a factor of three in the thermal neutron field and an under-response of ∼85 % in the mixed fields. REM-500 (tissue-equivalent proportional counter) exhibited a response close to 1.0 in the fast neutron fields and an under-response of ∼50 % in the thermal neutron field.

Adaptation of multi-joint balance coordination to whole body force fields

NARCIS (Netherlands)

Engelhart, Denise; Schouten, Alfred Christiaan; Pasma, Jantsje; Aarts, Ronald G.K.M.; Pasma, J.; Meskers, Carel; Maier, Andrea; van der Kooij, Herman

2014-01-01

Background and aim: The ankles and the hips play an important role in standing balance. Multi-joint coordination adapts with task, the magnitude and type of disturbance [1]. Arm studies show that postural responses are highly dependent on externally applied force fields [2]. Our aim is to study how

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasaka, Naotaka

2004-04-01

Effects of Coulomb collisions on neutral beam (NB) injected fast ions into Field-Reversed Configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing down and pitch angle collisions. The Monte-Carlo method is used for the pitch angle scattering, and the friction term is added to the equation of motion to show effects of slowing down collision such as the deposited power profile. Calculation parameters used are relevant to the NB injection on the FRC Injection Experiment (FIX) device. It is found that the dominant local power deposition occurs in the open field region between the X-point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found negligible. The loss mechanism due to non-adiabatic fast ion motion, which is intrinsic in non-uniform FRC plasmas, affects much greater than the pitch angle scattering by Coulomb collision. (author)

Magnetic-field generation and electron-collimation analysis for propagating fast electron beams in overdense plasmas

International Nuclear Information System (INIS)

Cai Hongbo; Zhu Shaoping; Chen Mo; Wu Sizhong; He, X. T.; Mima, Kunioki

2011-01-01

An analytical fluid model is proposed for artificially collimating fast electron beams produced in the interaction of ultraintense laser pulses with specially engineered low-density-core-high-density-cladding structure targets. Since this theory clearly predicts the characteristics of the spontaneously generated magnetic field and its dependence on the plasma parameters of the targets transporting fast electrons, it is of substantial relevance to the target design for fast ignition. The theory also reveals that the rapid changing of the flow velocity of the background electrons in a transverse direction (perpendicular to the flow velocity) caused by the density jump dominates the generation of a spontaneous interface magnetic field for these kinds of targets. It is found that the spontaneously generated magnetic field reaches as high as 100 MG, which is large enough to collimate fast electron transport in overdense plasmas. This theory is also supported by numerical simulations performed using a two-dimensional particle-in-cell code. It is found that the simulation results agree well with the theoretical analysis.

Fast electric field waveforms and near-surface electric field images of lightning discharges detected on Mt. Aragats in Armenia

International Nuclear Information System (INIS)

Chilingarian, A.; Khanikyants, Y.; Kozliner, L.; Soghomonyan, S.

2016-01-01

We present the observational data on fast electric waveforms that are detected at 3200 m altitudes above sea level on Mt. Aragats in Armenia during thunderstorms. We analyse the relations of these forms with count rates of particle flux (during Thunderstorm Ground Enhancements -TGEs); to the slow disturbance of the near-surface electrostatic field; and to the lightning location data from the World Wide Lightning Location Network (WWLLN). An observed negative lightning that decreases a negative charge overhead often abruptly terminates TGEs. By analysing the recorded fast electric field waveforms and comparing them with similar classified waveforms reported previously, we could identify the type and polarity of the observed lightnings. (author)

Measuring and modeling the temporal dynamics of nitrogen balance in an experimental-scale paddy field

Science.gov (United States)

Tseng, C.; Lin, Y.

2013-12-01

Nitrogen balance involves many mechanisms and plays an important role to maintain the function of nature. Fertilizer application in agriculture activity is usually seen as a common and significant nitrogen input to environment. Improper fertilizer application on paddy field can result in great amount of various types of nitrogen losses. Hence, it is essential to understand and quantify the nitrogen dynamics in paddy field for fertilizer management and pollution control. In this study, we develop a model which considers major transformation processes of nitrogen (e.g. volatilization, nitrification, denitrification and plant uptake). In addition, we measured different types of nitrogen in plants, soil and water at plant growth stages in an experimental-scale paddy field in Taiwan. The measurement includes total nitrogen in plants and soil, and ammonium-N (NH4+-N), nitrate-N (NO3--N) and organic nitrogen in water. The measured data were used to calibrate the model parameters and validate the model for nitrogen balance simulation. The results showed that the model can accurately estimate the temporal dynamics of nitrogen balance in paddy field during the whole growth stage. This model might be helpful and useful for future fertilizer management and pollution control in paddy field.

Fast Near-Field Calculation for Volume Integral Equations for Layered Media

DEFF Research Database (Denmark)

Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav

2005-01-01

. Afterwards, the scattered electric field can be easily computed at a regular rectangular grid on any horizontal plane us-ing a 2-dimensional FFT. This approach provides significant speedup in the near-field calculation in comparison to a straightforward numerical evaluation of the ra-diation integral since......An efficient technique based on the Fast Fourier Transform (FFT) for calculating near-field scattering by dielectric objects in layered media is presented. A higher or-der method of moments technique is employed to solve the volume integral equation for the unknown induced volume current density...

Designing research of fast neutron radiation field based on the reactor

International Nuclear Information System (INIS)

Zhang Wenzhong; Zhang Xiaomin

2009-01-01

Based on the Tsinghua University experimental nuclear reactor neutron source, this research designed moderate theory technical scheme, and the thickness of materials in the scheme were selected by means of Monte Carlo simulating method. An fast neutron radiation field was gained. (authors)

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasawa, Naotaka

2004-01-01

The effects of Coulomb collisions on neutral beam (NB) injected fast ions into field-reversed configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing-down and pitch-angle collisions. The Monte Carlo method is used for the pitch-angle scattering, and the friction term is added to the equation of motion to show the effects of the slowing-down collision, such as the deposited power profile. The calculation parameters used are relevant to the NB injection on the FRC injection experiment device [T. Asai, Y. Suzuki, T. Yoneda, F. Kodera, M. Okubo, and S. Goto, Phys. Plasmas 7, 2294 (2000)]. It is found that the dominant local power deposition occurs in the open field region between the X point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch-angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found to be negligible. The loss mechanism due to nonadiabatic fast ion motion, which is intrinsic in nonuniform FRC plasmas, has a much greater effect than the pitch-angle scattering by Coulomb collision

Coupled energy-drift and force-balance equations for high-field hot-carrier transport

International Nuclear Information System (INIS)

Huang, Danhong; Alsing, P.M.; Apostolova, T.; Cardimona, D.A.

2005-01-01

Coupled energy-drift and force-balance equations that contain a frictional force for the center-of-mass motion of electrons are derived for hot-electron transport under a strong dc electric field. The frictional force is found to be related to the net rate of phonon emission, which takes away the momentum of a phonon from an electron during each phonon-emission event. The net rate of phonon emission is determined by the Boltzmann scattering equation, which depends on the distribution of electrons interacting with phonons. The work done by the frictional force is included into the energy-drift equation for the electron-relative scattering motion and is found to increase the thermal energy of the electrons. The importance of the hot-electron effect in the energy-drift term under a strong dc field is demonstrated in reducing the field-dependent drift velocity and mobility. The Doppler shift in the energy conservation of scattering electrons interacting with impurities and phonons is found to lead to an anisotropic distribution of electrons in the momentum space along the field direction. The importance of this anisotropic distribution is demonstrated through a comparison with the isotropic energy-balance equation, from which we find that defining a state-independent electron temperature becomes impossible. To the leading order, the energy-drift equation is linearized with a distribution function by expanding it into a Fokker-Planck-type equation, along with the expansions of both the force-balance equation and the Boltzmann scattering equation for hot phonons

Pregnancy outcomes after paternal radiofrequency field exposure aboard fast patrol boats.

Science.gov (United States)

Baste, Valborg; Moen, Bente E; Oftedal, Gunnhild; Strand, Leif Age; Bjørge, Line; Mild, Kjell Hansson

2012-04-01

To investigate adverse reproductive outcomes among male employees in the Royal Norwegian Navy exposed to radiofrequency electromagnetic fields aboard fast patrol boats. Cohort study of Royal Norwegian Navy servicemen linked to the Medical Birth Registry of Norway, including singleton offspring born between 1967 and 2008 (n = 37,920). Exposure during the last 3 months before conception (acute) and exposure more than 3 months before conception (nonacute) were analyzed. Perinatal mortality and preeclampsia increased after service aboard fast patrol boats during an acute period and also after increased estimated radiofrequency exposure during an acute period, compared with service aboard other vessels. No associations were found between nonacute exposure and any of the reproductive outcomes. Paternal work aboard fast patrol boats during an acute period was associated with perinatal mortality and preeclampsia, but the cause is not clear.

Detection of fast oscillating magnetic fields using dynamic multiple TR imaging and Fourier analysis.

Directory of Open Access Journals (Sweden)

Ki Hwan Kim

Full Text Available Neuronal oscillations produce oscillating magnetic fields. There have been trials to detect neuronal oscillations using MRI, but the detectability in in vivo is still in debate. Major obstacles to detecting neuronal oscillations are (i weak amplitudes, (ii fast oscillations, which are faster than MRI temporal resolution, and (iii random frequencies and on/off intervals. In this study, we proposed a new approach for direct detection of weak and fast oscillating magnetic fields. The approach consists of (i dynamic acquisitions using multiple times to repeats (TRs and (ii an expanded frequency spectral analysis. Gradient echo echo-planar imaging was used to test the feasibility of the proposed approach with a phantom generating oscillating magnetic fields with various frequencies and amplitudes and random on/off intervals. The results showed that the proposed approach could precisely detect the weak and fast oscillating magnetic fields with random frequencies and on/off intervals. Complex and phase spectra showed reliable signals, while no meaningful signals were observed in magnitude spectra. A two-TR approach provided an absolute frequency spectrum above Nyquist sampling frequency pixel by pixel with no a priori target frequency information. The proposed dynamic multiple-TR imaging and Fourier analysis are promising for direct detection of neuronal oscillations and potentially applicable to any pulse sequences.

Convergence of highly parallel stray field calculation using the fast multipole method on irregular meshes

Science.gov (United States)

Palmesi, P.; Abert, C.; Bruckner, F.; Suess, D.

2018-05-01

Fast stray field calculation is commonly considered of great importance for micromagnetic simulations, since it is the most time consuming part of the simulation. The Fast Multipole Method (FMM) has displayed linear O(N) parallelization behavior on many cores. This article investigates the error of a recent FMM approach approximating sources using linear—instead of constant—finite elements in the singular integral for calculating the stray field and the corresponding potential. After measuring performance in an earlier manuscript, this manuscript investigates the convergence of the relative L2 error for several FMM simulation parameters. Various scenarios either calculating the stray field directly or via potential are discussed.

A compact wideband precision impedance measurement system based on digital auto-balancing bridge

International Nuclear Information System (INIS)

Hu, Binxin; Wang, Jinyu; Song, Guangdong; Zhang, Faxiang

2016-01-01

The ac impedance spectroscopy measurements are predominantly taken by using impedance analyzers based on analog auto-balancing bridge. However, those bench-top analyzers are generally complicated, bulky and expensive, thus limiting their usage in industrial field applications. This paper presents the development of a compact wideband precision measurement system based on digital auto-balancing bridge. The methods of digital auto-balancing bridge and digital lock-in amplifier are analyzed theoretically. The overall design and several key sections including null detector, direct digital synthesizer-based sampling clock, and digital control unit are introduced in detail. The results show that the system achieves a basic measurement accuracy of 0.05% with a frequency range of 20 Hz–2 MHz. The advantages of versatile measurement capacity, fast measurement speed, small size and low cost make it quite suitable for industrial field applications. It is demonstrated that this system is practical and effective by applying in determining the impedance-temperature characteristic of a motor starter PTC thermistor. (paper)

Magnetic activity in the Galactic Centre region - fast downflows along rising magnetic loops

Science.gov (United States)

Kakiuchi, Kensuke; Suzuki, Takeru K.; Fukui, Yasuo; Torii, Kazufumi; Enokiya, Rei; Machida, Mami; Matsumoto, Ryoji

2018-06-01

We studied roles of the magnetic field on the gas dynamics in the Galactic bulge by a three-dimensional global magnetohydrodynamical simulation data, particularly focusing on vertical flows that are ubiquitously excited by magnetic activity. In local regions where the magnetic field is stronger, it is frequently seen that fast downflows slide along inclined magnetic field lines that are associated with buoyantly rising magnetic loops. The vertical velocity of these downflows reaches ˜100 km s-1 near the footpoint of the loops by the gravitational acceleration towards the Galactic plane. The two footpoints of rising magnetic loops are generally located at different radial locations and the field lines are deformed by the differential rotation. The angular momentum is transported along the field lines, and the radial force balance breaks down. As a result, a fast downflow is often observed only at the one footpoint located at the inner radial position. The fast downflow compresses the gas to form a dense region near the footpoint, which will be important in star formation afterwards. Furthermore, the horizontal components of the velocity are also fast near the footpoint because the downflow is accelerated along the magnetic sliding slope. As a result, the high-velocity flow creates various characteristic features in a simulated position-velocity diagram, depending on the viewing angle.

Energetic-particle-driven instabilities and induced fast-ion transport in a reversed field pinch

International Nuclear Information System (INIS)

Lin, L.; Brower, D. L.; Ding, W. X.; Anderson, J. K.; Capecchi, W.; Eilerman, S.; Forest, C. B.; Koliner, J. J.; Nornberg, M. D.; Reusch, J.; Sarff, J. S.; Liu, D.

2014-01-01

Multiple bursty energetic-particle (EP) driven modes with fishbone-like structure are observed during 1 MW tangential neutral-beam injection in a reversed field pinch (RFP) device. The distinguishing features of the RFP, including large magnetic shear (tending to add stability) and weak toroidal magnetic field (leading to stronger drive), provide a complementary environment to tokamak and stellarator configurations for exploring basic understanding of EP instabilities. Detailed measurements of the EP mode characteristics and temporal-spatial dynamics reveal their influence on fast ion transport. Density fluctuations exhibit a dynamically evolving, inboard-outboard asymmetric spatial structure that peaks in the core where fast ions reside. The measured mode frequencies are close to the computed shear Alfvén frequency, a feature consistent with continuum modes destabilized by strong drive. The frequency pattern of the dominant mode depends on the fast-ion species. Multiple frequencies occur with deuterium fast ions compared to single frequency for hydrogen fast ions. Furthermore, as the safety factor (q) decreases, the toroidal mode number of the dominant EP mode transits from n=5 to n=6 while retaining the same poloidal mode number m=1. The transition occurs when the m=1, n=5 wave-particle resonance condition cannot be satisfied as the fast-ion safety factor (q fi ) decreases. The fast-ion temporal dynamics, measured by a neutral particle analyzer, resemble a classical predator-prey relaxation oscillation. It contains a slow-growth phase arising from the beam fueling followed by a rapid drop when the EP modes peak, indicating that the fluctuation-induced transport maintains a stiff fast-ion density profile. The inferred transport rate is strongly enhanced with the onset of multiple EP modes

Fast propagation of electromagnetic fields through graded-index media.

Science.gov (United States)

Zhong, Huiying; Zhang, Site; Shi, Rui; Hellmann, Christian; Wyrowski, Frank

2018-04-01

Graded-index (GRIN) media are widely used for modeling different situations: some components are designed considering GRIN modulation, e.g., multi-mode fibers, optical lenses, or acousto-optical modulators; on the other hand, there are other components where the refractive-index variation is undesired due to, e.g., stress or heating; and finally, some effects in nature are characterized by a GRIN variation, like turbulence in air or biological tissues. Modeling electromagnetic fields propagating in GRIN media is then of high importance for optical simulation and design. Though ray tracing can be used to evaluate some basic effects in GRIN media, the field properties are not considered and evaluated. The general physical optics techniques, like finite element method or finite difference time domain, can be used to calculate fields in GRIN media, but they need great numerical effort or may even be impractical for large-scale components. Therefore, there still exists a demand for a fast physical optics model of field propagation through GRIN media on a large scale, which will be explored in this paper.

Fast dose planning Monte Carlo simulations in inhomogeneous phantoms submerged in uniform, static magnetic fields

International Nuclear Information System (INIS)

Yanez, R.; Dempsey, J. F.

2007-01-01

We present studies in support of the development of a magnetic resonance imaging (MRI) guided intensity modulated radiation therapy (IMRT) device for the treatment of cancer patients. Fast and accurate computation of the absorbed ionizing radiation dose delivered in the presence of the MRI magnetic field are required for clinical implementation. The fast Monte Carlo simulation code DPM, optimized for radiotherapy treatment planning, is modified to simulate absorbed doses in uniform, static magnetic fields, and benchmarked against PENELOPE. Simulations of dose deposition in inhomogeneous phantoms in which a low density material is sandwiched in water shows that a lower MRI field strength (0.3 T) is to prefer in order to avoid dose build-up near material boundaries. (authors)

Mean field theory for a balanced hypercolumn model of orientation selectivity in primary visual cortex

DEFF Research Database (Denmark)

Lerchner, Alexander; Sterner, G.; Hertz, J.

2006-01-01

We present a complete mean field theory for a balanced state of a simple model of an orientation hypercolumn, with a numerical procedure for solving the mean-field equations quantitatively. With our treatment, one can determine self-consistently both the firing rates and the firing correlations...

Proton probe measurement of fast advection of magnetic fields by hot electrons

International Nuclear Information System (INIS)

Willingale, L; Thomas, A G R; Nilson, P M; Kaluza, M C; Dangor, A E; Evans, R G; Fernandes, P; Haines, M G; Kamperidis, C; Kingham, R J; Ridgers, C P; Sherlock, M; Wei, M S; Najmudin, Z; Krushelnick, K; Bandyopadhyay, S; Notley, M; Minardi, S; Rozmus, W; Tatarakis, M

2011-01-01

A laser generated proton beam was used to measure the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target. At intensities of 10 15 W cm −2 , the significant hot electron production and strong heat fluxes result in non-local transport becoming important to describe the magnetic field dynamics. Two-dimensional implicit Vlasov–Fokker–Planck modeling shows that fast advection of the magnetic field from the focal region occurs via the Nernst effect at significantly higher velocities than the sound speed, v N /c s ≈ 10.

Moessbauer study of the fast magnetization reversal forced in permalloy and invar by an external rf magnetic field

International Nuclear Information System (INIS)

Kopcewicz, M.

1978-01-01

The effect of fast magnetization reversal leading to fast relaxation of the hyperfine field (collapse effect) forced by an external rf magnetic field is studied using the Moessbauer technique for permalloy and invar. The rf collapse and sideband effects are investigated as a function of external rf field, frequency, and intensity. The collapse of the hfs spectrum through unresolved hfs spectrum, triangular shape to a single line, as well as the formation of sidebands is observed. The rf collapse effect is attributed to the rf forced uniform rotation of internal magnetization which causes fast magnetization reversal leading to fast relaxation of the hyperfine field as a result of which the average field at the Moessbauer nuclei is reduced to zero. The difference of the magnetization reversal process in permalloy and invar are discussed. It is shown that the origin of collapse and sideband effects is totaly different: the collapse effect being of purely magnetic origin while the formation of sidebands is due to the rf induced mechanical vibrations of iron atoms within the sample. It is possible to damp sidebands without affecting the collapse effect. The results obtained show that the application of the rf field to ferromagnetic materials gives a unique possibility to force, simulate, and control the relaxation effects in ferromagnetic materials. (author)

Balance and gait in children with dyslexia.

Science.gov (United States)

Moe-Nilssen, Rolf; Helbostad, Jorunn L; Talcott, Joel B; Toennessen, Finn Egil

2003-05-01

Tests of postural stability have provided some evidence of a link between deficits in gross motor skills and developmental dyslexia. The ordinal-level scales used previously, however, have limited measurement sensitivity, and no studies have investigated motor performance during walking in participants with dyslexia. The purpose of this study was to investigate if continuous-scaled measures of standing balance and gait could discriminate between groups of impaired and normal readers when investigators were blind to group membership during testing. Children with dyslexia ( n=22) and controls ( n=18), aged 10-12 years, performed walking tests at four different speeds (slow-preferred-fast-very fast) on an even and an uneven surface, and tests of unperturbed and perturbed body sway during standing. Body movements were registered by a triaxial accelerometer over the lower trunk, and measures of reaction time, body sway, walking speed, step length and cadence were calculated. Results were controlled for gender differences. Tests of standing balance with eyes closed did not discriminate between groups. All unperturbed standing tests with eyes open showed significant group differences ( Pwalking speed during very fast walking on both flat and uneven surface was > or =0.2 m/s ( Pwalking speed ( Pwalking speed as well as cadence at a normalised speed discriminated better between groups when subjects were walking on an uneven surface compared to a flat floor. Continuous-scaled walking tests performed in field settings may be suitable for motor skill assessment as a component of a screening tool for developmental dyslexia.

Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

Science.gov (United States)

Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

2012-10-01

A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

General remarks on fast neutron reactor physics

International Nuclear Information System (INIS)

Barre, J.Y.

1980-01-01

The main aspects of fast reactor physics, presented in these lecture notes, are restricted to LMFBR's. The emphasis is placed on the core neutronic balance and the burn-up problems. After a brief description of the power reactor main components and of the fast reactor chronology, the fundamental parameters of the one-group neutronic balance are briefly reviewed. Then the neutronic burn-up problems related to the Pu production and to the doubling time are considered

Active tower damping and pitch balancing - design, simulation and field test

Science.gov (United States)

Duckwitz, Daniel; Shan, Martin

2014-12-01

The tower is one of the major components in wind turbines with a contribution to the cost of energy of 8 to 12% [1]. In this overview the load situation of the tower will be described in terms of sources of loads, load components and fatigue contribution. Then two load reduction control schemes are described along with simulation and field test results. Pitch Balancing is described as a method to reduce aerodynamic asymmetry and the resulting fatigue loads. Active Tower Damping is reducing the tower oscillations by applying appropiate pitch angle changes. A field test was conducted on an Areva M5000 wind turbine.

Aquatic Exposure Predictions of Insecticide Field Concentrations Using a Multimedia Mass-Balance Model.

Science.gov (United States)

Knäbel, Anja; Scheringer, Martin; Stehle, Sebastian; Schulz, Ralf

2016-04-05

Highly complex process-driven mechanistic fate and transport models and multimedia mass balance models can be used for the exposure prediction of pesticides in different environmental compartments. Generally, both types of models differ in spatial and temporal resolution. Process-driven mechanistic fate models are very complex, and calculations are time-intensive. This type of model is currently used within the European regulatory pesticide registration (FOCUS). Multimedia mass-balance models require fewer input parameters to calculate concentration ranges and the partitioning between different environmental media. In this study, we used the fugacity-based small-region model (SRM) to calculate predicted environmental concentrations (PEC) for 466 cases of insecticide field concentrations measured in European surface waters. We were able to show that the PECs of the multimedia model are more protective in comparison to FOCUS. In addition, our results show that the multimedia model results have a higher predictive power to simulate varying field concentrations at a higher level of field relevance. The adaptation of the model scenario to actual field conditions suggests that the performance of the SRM increases when worst-case conditions are replaced by real field data. Therefore, this study shows that a less complex modeling approach than that used in the regulatory risk assessment exhibits a higher level of protectiveness and predictiveness and that there is a need to develop and evaluate new ecologically relevant scenarios in the context of pesticide exposure modeling.

Balanced growth path solutions of a Boltzmann mean field game model for knowledge growth

KAUST Repository

Burger, Martin

2016-11-18

In this paper we study balanced growth path solutions of a Boltzmann mean field game model proposed by Lucas and Moll [15] to model knowledge growth in an economy. Agents can either increase their knowledge level by exchanging ideas in learning events or by producing goods with the knowledge they already have. The existence of balanced growth path solutions implies exponential growth of the overall production in time. We prove existence of balanced growth path solutions if the initial distribution of individuals with respect to their knowledge level satisfies a Pareto-tail condition. Furthermore we give first insights into the existence of such solutions if in addition to production and knowledge exchange the knowledge level evolves by geometric Brownian motion.

Estimate of an environmental magnetic field of fast radio bursts

International Nuclear Information System (INIS)

Lin, Wei-Li; Dai, Zi-Gao

2016-01-01

Fast radio bursts (FRBs) are a type of newly-discovered transient astronomical phenomenon. They have short durations, high dispersion measures and a high event rate. However, due to unknown distances and undetected electromagnetic counterparts at other wavebands, it is difficult to further investigate FRBs. Here we propose a method to study their environmental magnetic field using an indirect method. Starting with dispersion measures and rotation measures (RMs), we try to obtain the parallel magnetic field component B-bar ‖ which is the average value along the line of sight in the host galaxy. Because both RMs and redshifts are now unavailable, we demonstrate the dependence of B-bar ‖ on these two separate quantities. This result, if the RM and redshift of an FRB are measured, would be expected to provide a clue towards understanding an environmental magnetic field of an FRB. (paper)

A self-consistent model of a thermally balanced quiescent prominence in magnetostatic equilibrium in a uniform gravitational field

International Nuclear Information System (INIS)

Lerche, I.; Low, B.C.

1977-01-01

A theoretical model of quiescent prominences in the form of an infinite vertical sheet is presented. Self-consistent solutions are obtained by integrating simultaneously the set of nonlinear equations of magnetostatic equilibrium and thermal balance. The basic features of the models are: (1) The prominence matter is confined to a sheet and supported against gravity by a bowed magnetic field. (2) The thermal flux is channelled along magnetic field lines. (3) The thermal flux is everywhere balanced by Low's (1975) hypothetical heat sink which is proportional to the local density. (4) A constant component of the magnetic field along the length of the prominence shields the cool plasma from the hot surrounding. It is assumed that the prominence plasma emits more radiation than it absorbes from the radiation fields of the photosphere, chromosphere and corona, and the above hypothetical heat sink is interpreted to represent the amount of radiative loss that must be balanced by a nonradiative energy input. Using a central density and temperature of 10 11 particles cm -3 and 5000 K respectively, a magnetic field strength between 2 to 10 gauss and a thermal conductivity that varies linearly with temperature, the physical properties implied by the model are discussed. The analytic treatment can also be carried out for a class of more complex thermal conductivities. These models provide a useful starting point for investigating the combined requirements of magnetostatic equilibrium and thermal balance in the quiescent prominence. (Auth.)

White-light full-field OCT resolution improvement by image sensor colour balance adjustment: numerical simulation

International Nuclear Information System (INIS)

Kalyanov, A L; Lychagov, V V; Ryabukho, V P; Smirnov, I V

2012-01-01

The possibility of improving white-light full-field optical coherence tomography (OCT) resolution by image sensor colour balance tuning is shown numerically. We calculated the full-width at half-maximum (FWHM) of a coherence pulse registered by a silicon colour image sensor under various colour balance settings. The calculations were made for both a halogen lamp and white LED sources. The results show that the interference pulse width can be reduced by the proper choice of colour balance coefficients. The reduction is up to 18%, as compared with a colour image sensor with regular settings, and up to 20%, as compared with a monochrome sensor. (paper)

River Basin Water Assessment and Balance in fast developing areas in Viet Nam

Science.gov (United States)

Le, Van Chin; Ranzi, Roberto

2010-05-01

Uneven precipitation in space and time together with mismanagement and lack of knowledge about quantity and quality of water resources, have caused water shortages for water supply to large cities and irrigation areas in many regions of Viet Nam in the dry season. The rainy season (from June to October) counts for 80% of the total annual rainfall, while the water volume of dry season (from November to May of the following year) accounts for 20% only. Lack of sufficient water volumes occurs in some areas where the pressure of a fast increasing population (1.3% per year on average in the last decade in Viet Nam), intensive agricultural and industrial uses is one of the major problems facing sustainable development. For those areas an accurate water assessment and balance at the riverbasin scale is needed to manage the exploitation and appropriate use of water resources and plan future development. The paper describes the preliminary phase of the pilot development of the river basin water balance for the Day River Basin in the Red River delta in Viet Nam. The Day river basin includes a 7,897 km² area in the south-western part of the Red River in Viet Nam. The total population in the Day river basin exceeds 8 millions inhabitants, including the Hanoi capital, Nam Dinh and other large towns. Agricultural land covered 390,294 ha in 2000 and this area is going to be increased by 14,000 ha in 2010 due to land reclamation and expansion toward the sea. Agricultural uses exploit about 90% of surface water resources in the Day river basin but have to compete with industrial and civil needs in the recent years. At the background of the brief characterization of the Day River Basin, we concentrate on the application of a water balance model integrated by an assessment of water quality after consumptive uses for civil, agricultural and industrial needs to assist water management in the basin. In addition, future development scenarios are taken into account, considering less

Optimization of field homogeneity of Helmholtz-like coils for measuring the balance of planar gradiometers

International Nuclear Information System (INIS)

Nordahn, M.A.; Holst, T.; Shen, Y.Q.

1999-01-01

Measuring the balance of planar SQUID gradiometers using a relatively small Helmholtz-like coil system requires a careful design of the coils in order to have a high degree of field uniformity along the radial direction. The level to which planar gradiometers can be balanced will be affected by any misalignment of the gradiometer relative to the ideal central position. Therefore, the maximum degree of balancing possible is calculated numerically for the Helmholtz geometry under various perturbations, including misalignment of the gradiometer along the cylindrical and the radial axis, and angular tilting relative to the normal plane. Furthermore, if the ratio between the coil separation and coil radius is chosen to be less than unity, calculations show that the expected radial uniformity of the field can be improved considerably compared to the traditional Helmholtz geometry. The optimized coil geometry is compared to the Helmholtz geometry and is found to yield up to an order of magnitude improvement of the worst case error signal within a volume spanned by the uncertainty in the alignment. (author)

Detailed balance principle and finite-difference stochastic equation in a field theory

International Nuclear Information System (INIS)

Kozhamkulov, T.A.

1986-01-01

A finite-difference equation, which is a generalization of the Langevin equation in field theory, has been obtained basing upon the principle of detailed balance for the Markov chain. Advantages of the present approach as compared with the conventional Parisi-Wu method are shown for examples of an exactly solvable problem of zero-dimensional quantum theory and a simple numerical simulation

The impact of previous knee injury on force plate and field-based measures of balance.

Science.gov (United States)

Baltich, Jennifer; Whittaker, Jackie; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Nigg, Benno M; Emery, Carolyn

2015-10-01

Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease. This study examines the association between youth sport-related knee injury and balance, 3-10years post-injury. Participants included 50 individuals (ages 15-26years) with a sport-related intra-articular knee injury sustained 3-10years previously and 50 uninjured age-, sex- and sport-matched controls. Force-plate measures during single-limb stance (center-of-pressure 95% ellipse-area, path length, excursion, entropic half-life) and field-based balance scores (triple single-leg hop, star-excursion, unipedal dynamic balance) were collected. Descriptive statistics (mean within-pair difference; 95% confidence intervals) were used to compare groups. Linear regression (adjusted for injury history) was used to assess the relationship between ellipse-area and field-based scores. Injured participants on average demonstrated greater medio-lateral excursion [mean within-pair difference (95% confidence interval); 2.8mm (1.0, 4.5)], more regular medio-lateral position [10ms (2, 18)], and shorter triple single-leg hop distances [-30.9% (-8.1, -53.7)] than controls, while no between group differences existed for the remaining outcomes. After taking into consideration injury history, triple single leg hop scores demonstrated a linear association with ellipse area (β=0.52, 95% confidence interval 0.01, 1.01). On average the injured participants adjusted their position less frequently and demonstrated a larger magnitude of movement during single-limb stance compared to controls. These findings support the evaluation of balance outcomes in the period between knee injury and post-traumatic osteoarthritis onset. Copyright © 2015 Elsevier Ltd. All rights

An investigation of the field-aligned currents associated with a large-scale ULF wave using data from CUTLASS and FAST

Directory of Open Access Journals (Sweden)

H. C. Scoffield

2005-02-01

Full Text Available On 14 December 1999, a large-scale ULF wave event was observed by the Hankasalmi radar of the SuperDARN chain. Simultaneously, the FAST satellite passed through the Hankasalmi field-of-view, measuring the magnetic field oscillations of the wave at around 2000km altitude, along with the precipitating ion and electron populations associated with these fields. A simple field line resonance model of the wave has been created and scaled using the wave's spatial and temporal characteristics inferred from SuperDARN and IMAGE magnetometer data. Here the model calculated field-aligned current is compared with field-aligned currents derived from the FAST energetic particle spectra and magnetic field measurements. This comparison reveals the small-scale structuring and energies of the current carriers in a large-scale Alfvén wave, a topic, which at present, is of considerable theoretical interest. When FAST traverses a region of the wave involving low upward field-aligned current densities, the current appears to be carried by unstructured downgoing electrons of energies less than 30eV. A downward current region appears to be carried partially by upgoing electrons below the FAST energy detection threshold, but also consists of a mixture of hotter downgoing magnetospheric electrons and upgoing ionospheric electrons of energies <30eV, with the hotter upgoing electrons presumably representing those upgoing electrons which have been accelerated by the wave field above the low energy detection threshold of FAST. A stronger interval of upward current shows that small-scale structuring of scale ~50km has been imposed on the current carriers, which are downgoing magnetospheric electrons of energy 0-500eV.

On a role of the Bsub(z) component of interplanetary magnetic field in a force balance in the day time magnetopause

International Nuclear Information System (INIS)

Kuznetsova, T.V.

1980-01-01

The role of interplanetary magnetic field (IMF) in the force balance in the day time magnetopause is discussed. The effect of the circular DR-current on the balance of pressures in the magnetopause is taken into account in the calculations. It is shown that IMF plays a significant role in the balance of forces in the day time magnetopause. The ratio of magnetic pressure to the thermal pressure of solar wind in subsolar point is k=0.5. The field observed in magnetosphere near the neutral line is lower by the value of transition region field. All the conclusions are obtained for Bsub(z) [ru

A fast continuous magnetic field measurement system based on digital signal processors

International Nuclear Information System (INIS)

Velev, G.V.; Carcagno, R.; DiMarco, J.; Kotelnikov, S.; Lamm, M.; Makulski, A.; Maroussov, V.; Nehring, R.; Nogiec, J.; Orris, D.; Poukhov, O.; Prakoshyn, F.; Schlabach, P.; Tompkins, J.C.

2005-01-01

In order to study dynamic effects in accelerator magnets, such as the decay of the magnetic field during the dwell at injection and the rapid so-called ''snapback'' during the first few seconds of the resumption of the energy ramp, a fast continuous harmonics measurement system was required. A new magnetic field measurement system, based on the use of digital signal processors (DSP) and Analog to Digital (A/D) converters, was developed and prototyped at Fermilab. This system uses Pentek 6102 16 bit A/D converters and the Pentek 4288 DSP board with the SHARC ADSP-2106 family digital signal processor. It was designed to acquire multiple channels of data with a wide dynamic range of input signals, which are typically generated by a rotating coil probe. Data acquisition is performed under a RTOS, whereas processing and visualization are performed under a host computer. Firmware code was developed for the DSP to perform fast continuous readout of the A/D FIFO memory and integration over specified intervals, synchronized to the probe's rotation in the magnetic field. C, C++ and Java code was written to control the data acquisition devices and to process a continuous stream of data. The paper summarizes the characteristics of the system and presents the results of initial tests and measurements

Ramadan fasting influences on food intake consumption, sleep ...

African Journals Online (AJOL)

AJL

2013-05-22

May 22, 2013 ... Key words: Ramadan fasting, food intake consumption, sleep schedule, body weight, plasma parameters, ... month of intermittent fasting (Nomani et al. ..... ponses to exercise, fluid, and energy balances during Ramadan in.

Numerical studies of fast ion slowing down rates in cool magnetized plasma using LSP

Science.gov (United States)

Evans, Eugene S.; Kolmes, Elijah; Cohen, Samuel A.; Rognlien, Tom; Cohen, Bruce; Meier, Eric; Welch, Dale R.

2016-10-01

In MFE devices, rapid transport of fusion products from the core into the scrape-off layer (SOL) could perform the dual roles of energy and ash removal. The first-orbit trajectories of most fusion products from small field-reversed configuration (FRC) devices will traverse the SOL, allowing those particles to deposit their energy in the SOL and be exhausted along the open field lines. Thus, the fast ion slowing-down time should affect the energy balance of an FRC reactor and its neutron emissions. However, the dynamics of fast ion energy loss processes under the conditions expected in the FRC SOL (with ρe code, to examine the effects of SOL density and background B-field on the slowing-down time of fast ions in a cool plasma. As we use explicit algorithms, these simulations must spatially resolve both ρe and λDe, as well as temporally resolve both Ωe and ωpe, increasing computation time. Scaling studies of the fast ion charge (Z) and background plasma density are in good agreement with unmagnetized slowing down theory. Notably, Z-scaling represents a viable way to dramatically reduce the required CPU time for each simulation. This work was supported, in part, by DOE Contract Number DE-AC02-09CH11466.

Two-dimensional calculation by finite element method of velocity field and temperature field development in fast reactor fuel assembly. II

International Nuclear Information System (INIS)

Schmid, J.

1985-11-01

A package of updated computer codes for velocity and temperature field calculations for a fast reactor fuel subassembly (or its part) by the finite element method is described. Isoparametric triangular elements of the second degree are used. (author)

Field assessment of balance in 10 to 14 year old children, reproducibility and validity of the Nintendo Wii board

DEFF Research Database (Denmark)

Larsen, Lisbeth Runge; Jørgensen, Martin Grønbech; Junge, Tina

2014-01-01

and adults. When assessing static balance, it is essential to use objective, sensitive tools, and these types of measurement have previously been performed in laboratory settings. However, the emergence of technologies like the Nintendo Wii Board (NWB) might allow balance assessment in field settings....... As the NWB has only been validated and tested for reproducibility in adults, the purpose of this study was to examine reproducibility and validity of the NWB in a field setting, in a population of children. METHODS: Fifty-four 10-14 year-olds from the CHAMPS-Study DK performed four different balance tests...... of the reproducibility study. CONCLUSION: Both NWB and AMTI have satisfactory reproducibility for testing static balance in a population of children. Concurrent validity of NWB compared with AMTI was satisfactory. Furthermore, the results from the concurrent validity study were comparable to the reproducibility results...

Solution-Processable Balanced Ambipolar Field-Effect Transistors Based on Carbonyl-Regulated Copolymers.

Science.gov (United States)

Yang, Chengdong; Fang, Renren; Yang, Xiongfa; Chen, Ru; Gao, Jianhua; Fan, Hanghong; Li, Hongxiang; Hu, Wenping

2018-04-04

It is very important to develop ambipolar field effect transistors to construct complementary circuits. To obtain balanced hole- and electron-transport properties, one of the key issues is to regulate the energy levels of the frontier orbitals of the semiconductor materials by structural tailoring, so that they match well with the electrode Fermi levels. Five conjugated copolymers were synthesized and exhibited low LUMO energy levels and narrow bandgaps on account of the strong electron-withdrawing effect of the carbonyl groups. Polymer thin film transistors were prepared by using a solution method and exhibited high and balanced hole and electron mobility of up to 0.46 cm 2  V -1  s -1 , which suggested that these copolymers are promising ambipolar semiconductor materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Active tower damping and pitch balancing – design, simulation and field test

International Nuclear Information System (INIS)

Duckwitz, Daniel; Shan, Martin

2014-01-01

The tower is one of the major components in wind turbines with a contribution to the cost of energy of 8 to 12% [1]. In this overview the load situation of the tower will be described in terms of sources of loads, load components and fatigue contribution. Then two load reduction control schemes are described along with simulation and field test results. Pitch Balancing is described as a method to reduce aerodynamic asymmetry and the resulting fatigue loads. Active Tower Damping is reducing the tower oscillations by applying appropiate pitch angle changes. A field test was conducted on an Areva M5000 wind turbine

Fast imaging of live organisms with sculpted light sheets

Science.gov (United States)

Chmielewski, Aleksander K.; Kyrsting, Anders; Mahou, Pierre; Wayland, Matthew T.; Muresan, Leila; Evers, Jan Felix; Kaminski, Clemens F.

2015-04-01

Light-sheet microscopy is an increasingly popular technique in the life sciences due to its fast 3D imaging capability of fluorescent samples with low photo toxicity compared to confocal methods. In this work we present a new, fast, flexible and simple to implement method to optimize the illumination light-sheet to the requirement at hand. A telescope composed of two electrically tuneable lenses enables us to define thickness and position of the light-sheet independently but accurately within milliseconds, and therefore optimize image quality of the features of interest interactively. We demonstrated the practical benefit of this technique by 1) assembling large field of views from tiled single exposure each with individually optimized illumination settings; 2) sculpting the light-sheet to trace complex sample shapes within single exposures. This technique proved compatible with confocal line scanning detection, further improving image contrast and resolution. Finally, we determined the effect of light-sheet optimization in the context of scattering tissue, devising procedures for balancing image quality, field of view and acquisition speed.

Fast penetration of megagauss fields into metallic conductors

International Nuclear Information System (INIS)

Schnitzer, Ory

2014-01-01

Megagauss magnetic-field penetration into a conducting material is studied via a simplified but representative model, wherein the magnetic-diffusion equation is coupled with a thermal-energy balance. The specific scenario considered is that of a prescribed magnetic field rising (in proportion to an arbitrary power r of time) at the surface of a conducting half-space whose electric conductivity is assumed proportional to an arbitrary inverse power γ of temperature. We employ a systematic asymptotic scheme in which the case of a strong surface field corresponds to a singular asymptotic limit. In this limit, the highly magnetized and hot “skin” terminates at a distinct propagating wave-front. Employing the method of matched asymptotic expansions, we find self-similar solutions of the magnetized region which match a narrow boundary-layer region about the advancing wave front. The rapidly decaying magnetic-field profile in the latter region is also self similar; when scaled by the instantaneous propagation speed, its shape is time-invariant, depending only on the parameter γ. The analysis furnishes a simple asymptotic formula for the skin-depth (i.e., the wave-front position), which substantially generalizes existing approximations. It scales with the power γr + 1∕2 of time and the power γ of field strength, and is much larger than the field-independent skin depth predicted by an athermal model. The formula further involves a dimensionless O(1) pre-factor which depends on r and γ. It is determined by solving a nonlinear eigenvalue problem governing the magnetized region. Another main result of the analysis, apparently unprecedented, is an asymptotic formula for the magnitude of the current-density peak characterizing the wave-front region. Complementary to these systematic results, we provide a closed-form but ad hoc generalization of the theory approximately applicable to arbitrary monotonically rising surface fields. Our results are in excellent agreement

Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.

Science.gov (United States)

Taylor, Nigel A S; Burdon, Catriona A; van den Heuvel, Anne M J; Fogarty, Alison L; Notley, Sean R; Hunt, Andrew P; Billing, Daniel C; Drain, Jace R; Silk, Aaron J; Patterson, Mark J; Peoples, Gregory E

2016-02-01

This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.

Principle of detailed balance and the finite-difference stochastic equation in field theory

International Nuclear Information System (INIS)

Kozhamkulov, T.A.

1986-01-01

The principle of detailed balance for the Markov chain is used to obtain a finite-difference equation which generalizes the Langevin equation in field theory. The advantages of using this approach compared to the conventional Parisi-Wu method are demonstrated for the examples of an exactly solvable problem in zero-dimensional quantum theory and a simple numerical simulation

Fast elastic e-H(2s) scattering in laser fields

International Nuclear Information System (INIS)

Vucic, S.; Hewitt, R.; Hewitt, R.

1997-01-01

A numerical method for the evaluation of the Born endash Floquet amplitude for laser-assisted scattering is proposed for the case when a large basis set is required to achieve convergence. The method is applied to analyze the elastic scattering of fast electrons by the H(2s) state in a low-intensity laser field of varying frequency and to study the resonant scattering with increasing laser intensity. While the behavior of an atom in a resonant field of low intensity is determined by virtual transitions between resonant levels, at high intensity a great number of nonresonant virtual transitions may significantly influence laser-assisted processes. As a consequence, the attenuation of resonant effects could appear, as well as the open-quotes localclose quotes stabilization of the atom against ionization. copyright 1997 The American Physical Society

A fast continuous magnetic field measurement system based on digital signal processors

Energy Technology Data Exchange (ETDEWEB)

Velev, G.V.; Carcagno, R.; DiMarco, J.; Kotelnikov, S.; Lamm, M.; Makulski, A.; /Fermilab; Maroussov, V.; /Purdue U.; Nehring, R.; Nogiec, J.; Orris, D.; /Fermilab; Poukhov,; Prakoshyn, F.; /Dubna, JINR; Schlabach, P.; Tompkins, J.C.; /Fermilab

2005-09-01

In order to study dynamic effects in accelerator magnets, such as the decay of the magnetic field during the dwell at injection and the rapid so-called ''snapback'' during the first few seconds of the resumption of the energy ramp, a fast continuous harmonics measurement system was required. A new magnetic field measurement system, based on the use of digital signal processors (DSP) and Analog to Digital (A/D) converters, was developed and prototyped at Fermilab. This system uses Pentek 6102 16 bit A/D converters and the Pentek 4288 DSP board with the SHARC ADSP-2106 family digital signal processor. It was designed to acquire multiple channels of data with a wide dynamic range of input signals, which are typically generated by a rotating coil probe. Data acquisition is performed under a RTOS, whereas processing and visualization are performed under a host computer. Firmware code was developed for the DSP to perform fast continuous readout of the A/D FIFO memory and integration over specified intervals, synchronized to the probe's rotation in the magnetic field. C, C++ and Java code was written to control the data acquisition devices and to process a continuous stream of data. The paper summarizes the characteristics of the system and presents the results of initial tests and measurements.

On a mean field game optimal control approach modeling fast exit scenarios in human crowds

KAUST Repository

Burger, Martin; Di Francesco, Marco; Markowich, Peter A.; Wolfram, Marie Therese

2013-01-01

The understanding of fast exit and evacuation situations in crowd motion research has received a lot of scientific interest in the last decades. Security issues in larger facilities, like shopping malls, sports centers, or festivals necessitate a better understanding of the major driving forces in crowd dynamics. In this paper we present an optimal control approach modeling fast exit scenarios in pedestrian crowds. The model is formulated in the framework of mean field games and based on a parabolic optimal control problem. We consider the case of a large human crowd trying to exit a room as fast as possible. The motion of every pedestrian is determined by minimizing a cost functional, which depends on his/her position and velocity, the overall density of people, and the time to exit. This microscopic setup leads in a mean-field formulation to a nonlinear macroscopic optimal control problem, which raises challenging questions for the analysis and numerical simulations.We discuss different aspects of the mathematical modeling and illustrate them with various computational results. ©2013 IEEE.

On a mean field game optimal control approach modeling fast exit scenarios in human crowds

KAUST Repository

Burger, Martin

2013-12-01

The understanding of fast exit and evacuation situations in crowd motion research has received a lot of scientific interest in the last decades. Security issues in larger facilities, like shopping malls, sports centers, or festivals necessitate a better understanding of the major driving forces in crowd dynamics. In this paper we present an optimal control approach modeling fast exit scenarios in pedestrian crowds. The model is formulated in the framework of mean field games and based on a parabolic optimal control problem. We consider the case of a large human crowd trying to exit a room as fast as possible. The motion of every pedestrian is determined by minimizing a cost functional, which depends on his/her position and velocity, the overall density of people, and the time to exit. This microscopic setup leads in a mean-field formulation to a nonlinear macroscopic optimal control problem, which raises challenging questions for the analysis and numerical simulations.We discuss different aspects of the mathematical modeling and illustrate them with various computational results. ©2013 IEEE.

Fast time-domain balanced homodyne detection of light

Czech Academy of Sciences Publication Activity Database

Haderka, Ondřej; Michálek, Václav; Urbášek, Vladimír; Ježek, M.

2009-01-01

Roč. 48, č. 15 (2009), 2884-2889 ISSN 0003-6935 R&D Projects: GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100522 Keywords : balanced homodyne detection * high-speed quantum-optical measurement * quantum cryptography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.410, year: 2009

Inexpensive and fast pathogenic bacteria screening using field-effect transistors.

Science.gov (United States)

Formisano, Nello; Bhalla, Nikhil; Heeran, Mel; Reyes Martinez, Juana; Sarkar, Amrita; Laabei, Maisem; Jolly, Pawan; Bowen, Chris R; Taylor, John T; Flitsch, Sabine; Estrela, Pedro

2016-11-15

While pathogenic bacteria contribute to a large number of globally important diseases and infections, current clinical diagnosis is based on processes that often involve culturing which can be time-consuming. Therefore, innovative, simple, rapid and low-cost solutions to effectively reduce the burden of bacterial infections are urgently needed. Here we demonstrate a label-free sensor for fast bacterial detection based on metal-oxide-semiconductor field-effect transistors (MOSFETs). The electric charge of bacteria binding to the glycosylated gates of a MOSFET enables quantification in a straightforward manner. We show that the limit of quantitation is 1.9×10(5) CFU/mL with this simple device, which is more than 10,000-times lower than is achieved with electrochemical impedance spectroscopy (EIS) and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-ToF) on the same modified surfaces. Moreover, the measurements are extremely fast and the sensor can be mass produced at trivial cost as a tool for initial screening of pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

Eddy Covariance Measurements Over a Maize Field: The Contribution of Minor Flux Terms to the Energy Balance Gap

Science.gov (United States)

Smidt, J.; Ingwersen, J.; Streck, T.

2015-12-01

The lack of energy balance closure is a long-standing problem in eddy covariance (EC) measurements. The energy balance equation is defined as Rn - G = H + λE, where Rn is net radiation, G is the ground heat flux, H is the sensible heat flux and λE is the latent heat flux. In most cases of energy imbalance, either Rn is overestimated or the ground heat and turbulent fluxes are underestimated. Multiple studies have shown that calculations, incorrect instrument installation/calibration and measurement errors alone do not entirely account for this imbalance. Rather, research is now focused on previously neglected sources of heat storage in the soil, biomass and air beneath the EC station. This project examined the potential of five "minor flux terms" - soil heat storage, biomass heat storage, energy consumption by photosynthesis, air heat storage and atmospheric moisture change, to further close the energy balance gap. Eddy covariance measurements were conducted at a maize (Zea mays) field in southwest Germany during summer 2014. Soil heat storage was measured for six weeks at 11 sites around the field footprint. Biomass and air heat storage were measured for six subsequent weeks at seven sites around the field footprint. Energy consumption by photosynthesis was calculated using the CO2 flux data. Evapotranspiration was calculated using the water balance method and then compared to the flux data processed with three post-closure methods: the sensible heat flux, the latent heat flux and the Bowen ratio post-closure methods. An energy balance closure of 66% was achieved by the EC station measurements over the entire investigation period. During the soil heat flux campaign, EC station closure was 74.1%, and the field footprint soil heat storage contributed 3.3% additional closure. During the second minor flux term measurement period, closure with the EC station data was 91%. Biomass heat storage resulted in 1.1% additional closure, the photosynthesis flux closed the gap

Fast Ignition Thermonuclear Fusion: Enhancement of the Pellet Gain by the Colossal-Magnetic-Field Shells

Science.gov (United States)

Stefan, V. Alexander

2013-10-01

The fast ignition fusion pellet gain can be enhanced by a laser generated B-field shell. The B-field shell, (similar to Earth's B-field, but with the alternating B-poles), follows the pellet compression in a frozen-in B-field regime. A properly designed laser-pellet coupling can lead to the generation of a B-field shell, (up to 100 MG), which inhibits electron thermal transport and confines the alpha-particles. In principle, a pellet gain of few-100s can be achieved in this manner. Supported in part by Nikola Tesla Labs, Stefan University, 1010 Pearl, La Jolla, CA 92038-1007.

A coupled remote sensing and simplified surface energy balance approach to estimate actual evapotranspiration from irrigated fields

Science.gov (United States)

Senay, G.B.; Budde, Michael; Verdin, J.P.; Melesse, Assefa M.

2007-01-01

Accurate crop performance monitoring and production estimation are critical for timely assessment of the food balance of several countries in the world. Since 2001, the Famine Early Warning Systems Network (FEWS NET) has been monitoring crop performance and relative production using satellite-derived data and simulation models in Africa, Central America, and Afghanistan where ground-based monitoring is limited because of a scarcity of weather stations. The commonly used crop monitoring models are based on a crop water-balance algorithm with inputs from satellite-derived rainfall estimates. These models are useful to monitor rainfed agriculture, but they are ineffective for irrigated areas. This study focused on Afghanistan, where over 80 percent of agricultural production comes from irrigated lands. We developed and implemented a Simplified Surface Energy Balance (SSEB) model to monitor and assess the performance of irrigated agriculture in Afghanistan using a combination of 1-km thermal data and 250m Normalized Difference Vegetation Index (NDVI) data, both from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. We estimated seasonal actual evapotranspiration (ETa) over a period of six years (2000-2005) for two major irrigated river basins in Afghanistan, the Kabul and the Helmand, by analyzing up to 19 cloud-free thermal and NDVI images from each year. These seasonal ETa estimates were used as relative indicators of year-to-year production magnitude differences. The temporal water-use pattern of the two irrigated basins was indicative of the cropping patterns specific to each region. Our results were comparable to field reports and to estimates based on watershed-wide crop water-balance model results. For example, both methods found that the 2003 seasonal ETa was the highest of all six years. The method also captured water management scenarios where a unique year-to-year variability was identified in addition to water-use differences between

Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke.

Science.gov (United States)

Madhavan, Sangeetha; Bishnoi, Alka

2017-12-01

The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored. The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke. A retrospective exploratory design. Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers. Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p = 0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers. The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers.

FastMag: Fast micromagnetic simulator for complex magnetic structures (invited)

Science.gov (United States)

Chang, R.; Li, S.; Lubarda, M. V.; Livshitz, B.; Lomakin, V.

2011-04-01

A fast micromagnetic simulator (FastMag) for general problems is presented. FastMag solves the Landau-Lifshitz-Gilbert equation and can handle multiscale problems with a high computational efficiency. The simulator derives its high performance from efficient methods for evaluating the effective field and from implementations on massively parallel graphics processing unit (GPU) architectures. FastMag discretizes the computational domain into tetrahedral elements and therefore is highly flexible for general problems. The magnetostatic field is computed via the superposition principle for both volume and surface parts of the computational domain. This is accomplished by implementing efficient quadrature rules and analytical integration for overlapping elements in which the integral kernel is singular. Thus, discretized superposition integrals are computed using a nonuniform grid interpolation method, which evaluates the field from N sources at N collocated observers in O(N) operations. This approach allows handling objects of arbitrary shape, allows easily calculating of the field outside the magnetized domains, does not require solving a linear system of equations, and requires little memory. FastMag is implemented on GPUs with ?> GPU-central processing unit speed-ups of 2 orders of magnitude. Simulations are shown of a large array of magnetic dots and a recording head fully discretized down to the exchange length, with over a hundred million tetrahedral elements on an inexpensive desktop computer.

Wnt signaling balances specification of the cardiac and pharyngeal muscle fields

Science.gov (United States)

Mandal, Amrita; Holowiecki, Andrew; Song, Yuntao Charlie; Waxman, Joshua S.

2017-01-01

Canonical Wnt/β-catenin (Wnt) signaling plays multiple conserved roles during fate specification of cardiac progenitors in developing vertebrate embryos. Although lineage analysis in ascidians and mice has indicated there is a close relationship between the cardiac second heart field (SHF) and pharyngeal muscle (PM) progenitors, the signals underlying directional fate decisions of the cells within the cardio-pharyngeal muscle field in vertebrates are not yet understood. Here, we examined the temporal requirements of Wnt signaling in cardiac and PM development. In contrast to a previous report in chicken embryos that suggested Wnt inhibits PM development during somitogenesis, we find that in zebrafish embryos Wnt signaling is sufficient to repress PM development during anterior-posterior patterning. Importantly, the temporal sensitivity of dorso-anterior PMs to increased Wnt signaling largely overlaps with when Wnt signaling promotes specification of the adjacent cardiac progenitors. Furthermore, we find that excess early Wnt signaling can cell autonomously promote expansion of the first heart field (FHF) progenitors at the expense of PM and SHF within the anterior lateral plate mesoderm (ALPM). Our study provides insight into an antagonistic developmental mechanism that balances the sizes of the adjacent cardiac and PM progenitor fields in early vertebrate embryos. PMID:28087459

Microdosimetry of intermediate energy neutrons in fast neutron fields

International Nuclear Information System (INIS)

Saion, E.B.; Watt, D.E.

1988-01-01

A coaxial double cylindrical proportional counter has been constructed for microdosimetry of intermediate energy neutrons in mixed fields. Details are given of the measured gas gain and resolution characteristics of the counter for a wide range of anode voltages. Event spectra due to intermediate neutrons in any desired energy band is achieved by an appropriate choice of thickness of the common dividing wall in the counter and by appropriate use of the coincidence, anticoincidence pulse counting arrangements. Calculated estimates indicate that the dose contribution by fast neutrons to the energy deposition events in the intermediate neutron range may be as large as 25%. Empirical procedures being investigated aim to determine the necessary corrections to be applied to the microdose distributions, with a precision of 10%. (author)

Evaluation of Fast-Time Wake Models Using Denver 2006 Field Experiment Data

Science.gov (United States)

Ahmad, Nash’at N.; Pruis, Matthew J.

2015-01-01

The National Aeronautics and Space Administration conducted a series of wake vortex field experiments at Denver in 2003, 2005, and 2006. This paper describes the lidar wake vortex measurements and associated meteorological data collected during the 2006 deployment, and includes results of recent reprocessing of the lidar data using a new wake vortex algorithm and estimates of the atmospheric turbulence using a new algorithm to estimate eddy dissipation rate from the lidar data. The configuration and set-up of the 2006 field experiment allowed out-of-ground effect vortices to be tracked in lateral transport further than any previous campaign and thereby provides an opportunity to study long-lived wake vortices in moderate to low crosswinds. An evaluation of NASA's fast-time wake vortex transport and decay models using the dataset shows similar performance as previous studies using other field data.

Losses of neutral injected fast ions due to adiabaticity breaking processes in a field-reversed configuration

International Nuclear Information System (INIS)

Takahashi, Toshiki; Inoue, Koji; Ishizuka, Takashi; Kondoh, Yoshiomi; Iwasawa, Naotaka

2004-02-01

Losses of neutral beam (NB) injected fast ions from the confinement region of a Field-Reversed Configuration (FRC) with a strong magnetic mirror are numerically analyzed for parameters relevant to NB injection experiments on the FIX (FRC injection experiment) device [T. Asai et al., Phys. Plasmas 7, 2294 (2000)]. Ionization processes of beam particles are calculated by the Monte Carlo method. The confinement of beam ions is discussed with the concept of accessible regions that restrict the ion excursion and are determined from two constants of motion, the kinetic energy and canonical angular momentum, in the case of an axisymmetric and a steady state FRC without an electrostatic field. From the calculation of the accessible regions, it is found that all the fast ions suffer from the orbit loss on the wall surface and/or the end loss. Single particle orbits are also calculated to find a difference of confinement properties from the results by employing the accessible regions. The magnetic moment is observed to show non-adiabatic motions of the beam ions, which cause a gradual orbit loss on the wall even in a case that a strong magnetic mirror is applied. The results show that the correlation of the magnetic moment disappears as the fast ions experience the density gradient around the separatrix surface and the field-null points. (author)

Morphometric Controls on Glacier Mass Balance of the Puruogangri Ice Field, Central Tibetan Plateau

Directory of Open Access Journals (Sweden)

Lin Liu

2016-11-01

Full Text Available Evaluating the impacts of climatic changes and morphometric features on glacier mass balance is crucial to providing insight into glacier changes and their effects on regional water resources and ecosystems. Here, we presented an evaluation of morphometric effects on the glacier mass balances of the Puruogangri ice field (PIF on the Tibetan Plateau. A clear spatial variability of glacier mass balances, ranging from −0.035 to +0.019 m·w.e.·year−1, was estimated by comparing the TanDEM-X DEM (2012 with the SRTM-X DEM (2000. In general, the observed glacier mass changes were consistent with our fieldwork investigations. Furthermore, by applying the method of linear regression analysis, we found that the mass changes of individual glaciers on the PIF were mainly dominated by the mean altitude (R = 0.84, p < 0.001, however, they were statistically independent of glacier size, aspect, and surface velocity. At a local scale (grid size of 10 × 10 pixels, apart from the factor of altitude, surface velocity was correlated with glacier mass change.

TEMP-M program for thermal-hydraulic calculation of fast reactor fuel assemblies

International Nuclear Information System (INIS)

Bogoslovskaya, C.P.; Sorokin, A.P.; Tikhomirov, B.B.; Titov, P.A.; Ushakov, P.A.

1983-01-01

TEMP-M program (Fortran, BESM-6 computer) for thermal-hydraulic calculation of fast reactor fuel assemblies is described. Results of calculation of temperature field in a 127 fuel element assembly of BN-600, reactor accomplished according to TEMP-N program are considered as an example. Algorithm, realized in the program, enables to calculate the distributions of coolant heating, fuel element temperature (over perimeter and length) and assembly shell temperature. The distribution of coolant heating in assembly channels is determined from a solution of the balance equation system which accounts for interchannel exchange, nonadiabatic conditions on the assembly shell. The TEMP-M program gives necessary information for calculation of strength, seviceability of fast reactor core elements, serves an effective instrument for calculations when projecting reactor cores and analyzing thermal-hydraulic characteristics of operating reactor fuel assemblies

Fast algorithms for coordinate processors in Galois field for multiplicity t = 4.5 and t > 5

International Nuclear Information System (INIS)

Nikityuk, N.M.

1989-01-01

Fast algorithms for solving the coordinate equations for special-purpose processors at multiplicity t = 4.5 and t > 5 are described. Block diagrams of coordinate processor for t 4 in Galois field GF(2 m ) is presented which is solved by a table method. Economical algorithms for solving the coordinate equations by serial methods at t > 5 are described. The algorithms and devices proposed could be applied when creating fast processors in high energy physics spectrometers. 9 refs.; 3 figs

Fast wave power flow along SOL field lines in NSTX

Science.gov (United States)

Perkins, R. J.; Bell, R. E.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; Leblanc, B. P.; Kramer, G. J.; Phillips, C. K.; Roquemore, L.; Taylor, G.; Wilson, J. R.; Ahn, J.-W.; Gray, T. K.; Green, D. L.; McLean, A.; Maingi, R.; Ryan, P. M.; Jaeger, E. F.; Sabbagh, S.

2012-10-01

On NSTX, a major loss of high-harmonic fast wave (HHFW) power can occur along open field lines passing in front of the antenna over the width of the scrape-off layer (SOL). Up to 60% of the RF power can be lost and at least partially deposited in bright spirals on the divertor floor and ceiling [1,2]. The flow of HHFW power from the antenna region to the divertor is mostly aligned along the SOL magnetic field [3], which explains the pattern of heat deposition as measured with infrared (IR) cameras. By tracing field lines from the divertor back to the midplane, the IR data can be used to estimate the profile of HHFW power coupled to SOL field lines. We hypothesize that surface waves are being excited in the SOL, and these results should benchmark advanced simulations of the RF power deposition in the SOL (e.g., [4]). Minimizing this loss is critical optimal high-power long-pulse ICRF heating on ITER while guarding against excessive divertor erosion.[4pt] [1] J.C. Hosea et al., AIP Conf Proceedings 1187 (2009) 105. [0pt] [2] G. Taylor et al., Phys. Plasmas 17 (2010) 056114. [0pt] [3] R.J. Perkins et al., to appear in Phys. Rev. Lett. [0pt] [4] D.L. Green et al., Phys. Rev. Lett. 107 (2011) 145001.

High-field transport of electrons and radiative effects using coupled force-balance and Fokker-Planck equations beyond the relaxation-time approximation

International Nuclear Information System (INIS)

Huang, Danhong; Apostolova, T.; Alsing, P.M.; Cardimona, D.A.

2004-01-01

The dynamics of a many-electron system under both dc and infrared fields is separated into a center-of-mass and a relative motion. The first-order force-balance equation is employed for the slow center-of-mass motion of electrons, and the Fokker-Planck equation is used for the ultrafast relative scattering motion of degenerate electrons. This approach allows us to include the anisotropic energy-relaxation process which has been neglected in the energy-balance equation in the past. It also leads us to include the anisotropic coupling to the incident infrared field with different polarizations. Based on this model, the transport of electrons is explored under strong dc and infrared fields by going beyond the relaxation-time approximation. The anisotropic dependence of the electron distribution function on the parallel and perpendicular kinetic energies of electrons is displayed with respect to the dc field direction, and the effect of anisotropic coupling to an incident infrared field with polarizations parallel and perpendicular to the applied dc electric field is shown. The heating of electrons is more accurately described beyond the energy-balance equation with the inclusion of an anisotropic coupling to the infrared field. The drift velocity of electrons is found to increase with the amplitude of the infrared field due to a suppressed momentum-relaxation process (or frictional force) under parallel polarization but decreases with the amplitude due to an enhanced momentum-relaxation process under perpendicular polarization

Recent IAEA Achievements in the Field of Fast Reactors and Presentation of the Scope and Objectives of the Meeting

International Nuclear Information System (INIS)

Monti, Stefano

2013-01-01

Scope of the Technical Meeting: • Fast reactors deployment scenario are intensely being assessed worldwide, taking into consideration the main technical aspects and requirements, the different marked drivers including resource utilization, fuel cycle options, waste management, economic competitiveness and proliferation issues. • The theme of fast reactor deployment, scenarios and economics has been largely debated during the recent IAEA FR13 conference; Several papers discussed the economics of fast reactors from different national and regional perspectives. • This technical meeting addresses Member States’ expressed need for information exchange in the field, with the aim of identifying the main open issues and launching possible activities under the IAEA’s aegis. Main Objectives of the Meeting: • Identify issues and technical features that affect capital and energy production costs of fast reactors and related fuel cycle facilities. • Present FR concepts with enhanced economic characteristics, as well as innovative technical solutions that have the potential to reduce the capital costs of FR and related fuel cycle facilities. • Present energy models and advanced tools for the cost assessment of innovative fast reactors and associated nuclear fuel cycles. • Discuss the results of studies and on-going R&D activities that address cost reduction and the future economic competitiveness of fast reactors; and • Identify R&DT needs in the field, also in view of new IAEA initiatives to help and support Member States in improving the economic competitiveness of fast reactors and associated nuclear fuel cycles

Load Balancing Scientific Applications

Energy Technology Data Exchange (ETDEWEB)

Pearce, Olga Tkachyshyn [Texas A & M Univ., College Station, TX (United States)

2014-12-01

The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

Unified Dark Matter scalar field models with fast transition

Energy Technology Data Exchange (ETDEWEB)

Bertacca, Daniele [Dipartimento di Fisica Galileo Galilei, Università di Padova, via F. Marzolo 8, I-35131 Padova (Italy); Bruni, Marco [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom); Piattella, Oliver F. [Department of Physics, Universidade Federal do Espírito Santo, avenida Ferrari 514, 29075-910, Vitória, ES (Brazil); Pietrobon, Davide, E-mail: daniele.bertacca@pd.infn.it, E-mail: marco.bruni@port.ac.uk, E-mail: oliver.piattella@gmail.com, E-mail: davide.pietrobon@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109 Pasadena CA U.S.A. (United States)

2011-02-01

We investigate the general properties of Unified Dark Matter (UDM) scalar field models with Lagrangians with a non-canonical kinetic term, looking specifically for models that can produce a fast transition between an early Einstein-de Sitter CDM-like era and a later Dark Energy like phase, similarly to the barotropic fluid UDM models in JCAP01(2010)014. However, while the background evolution can be very similar in the two cases, the perturbations are naturally adiabatic in fluid models, while in the scalar field case they are necessarily non-adiabatic. The new approach to building UDM Lagrangians proposed here allows to escape the common problem of the fine-tuning of the parameters which plague many UDM models. We analyse the properties of perturbations in our model, focusing on the the evolution of the effective speed of sound and that of the Jeans length. With this insight, we can set theoretical constraints on the parameters of the model, predicting sufficient conditions for the model to be viable. An interesting feature of our models is that what can be interpreted as w{sub DE} can be < −1 without violating the null energy conditions.

Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric fields

International Nuclear Information System (INIS)

Liu, Chong; Dobrynin, Danil; Fridman, Alexander

2014-01-01

In this study, we report experimental results on fast intensified charge-coupled device (ICCD) imaging of the development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of the electric field in the discharge. The uniformity of the discharge images obtained with nanosecond exposure times was analysed using chi-square test. The results indicate that DBD uniformity strongly depends on the applied (global) electric field in the discharge gap, which is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is a transition from filamentary to uniform DBD mode that correlates to the corresponding decrease of the maximum local electric field in the discharge. (fast track communication)

Fast identification of the conduction-type of nanomaterials by field emission technique.

Science.gov (United States)

Yang, Xun; Gan, Haibo; Tian, Yan; Peng, Luxi; Xu, Ningsheng; Chen, Jun; Chen, Huanjun; Deng, Shaozhi; Liang, Shi-Dong; Liu, Fei

2017-10-12

There are more or less dopants or defects existing in nanomaterials, so they usually have different conduct-types even for the same substrate. Therefore, fast identification of the conduction-type of nanomaterials is very essential for their practical application in functional nanodevices. Here we use the field emission (FE) technique to research nanomaterials and establish a generalized Schottky-Nordheim (SN) model, in which an important parameter λ (the image potential factor) is first introduced to describe the effective image potential. By regarding λ as the criterion, their energy-band structure can be identified: (a) λ = 1: metal; (b) 0.5 p-type semiconductor. Moreover, this method can be utilized to qualitatively evaluate the doping-degree for a given semiconductor. We test numerically and experimentally a group of nanomaterial emitters and all results agree with our theoretical results very well, which suggests that our method based on FE measurements should be an ideal and powerful tool to fast ascertain the conduction-type of nanomaterials.

Z a Fast Pulsed Power Generator for Ultra-High Magnetic Field Generation

Science.gov (United States)

Spielman, R. B.; Stygar, W. A.; Struve, K. W.; Asay, J. R.; Hall, C. A.; Bernard, M. A.; Bailey, J. E.; McDaniel, D. H.

2004-11-01

Advances in fast, pulsed-power technologies have resulted in the development of very high current drivers that have current rise times ~100 ns. The largest such pulsed power driver today is the new Z accelerator located at Sandia National Laboratories in Albuquerque, New Mexico. Z can deliver more than 20 MA with a time-to-peak of 105 ns to low inductance (~1 nH) loads. Such large drivers are capable of directly generating magnetic fields approaching 3 kT in small, 1 cm3 volumes. In addition to direct field generation, Z can be used to compress an applied, axial seed field with a plasma. Flux compression schemes are not new and are, in fact, the basis of all explosive flux-compression generators, but we propose the use of plasma armatures rather than solid, conducting armatures. We present experimental results from the Z accelerator in which magnetic fields of ~2 kT are generated and measured with several diagnostics. Issues such as energy loss in solid conductors and dynamic response of current-carrying conductors to very large magnetic fields are reviewed in context with Z experiments. We describe planned flux-compression experiments that are expected to create the highest-magnitude uniform-field volumes yet attained in the laboratory.

A thermodynamical analysis of rf current drive with fast electrons

Energy Technology Data Exchange (ETDEWEB)

Bizarro, João P. S., E-mail: bizarro@ipfn.tecnico.ulisboa.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal)

2015-08-15

The problem of rf current drive (CD) by pushing fast electrons with high-parallel-phase-velocity waves, such as lower-hybrid (LH) or electron-cyclotron (EC) waves, is revisited using the first and second laws, the former to retrieve the well-known one-dimensional (1D) steady-state CD efficiency, and the latter to calculate a lower bound for the rate of entropy production when approaching steady state. The laws of thermodynamics are written in a form that explicitly takes care of frictional dissipation and are thus applied to a population of fast electrons evolving under the influence of a dc electric field, rf waves, and collisions while in contact with a thermal, Maxwellian reservoir with a well-defined temperature. Besides the laws of macroscopic thermodynamics, there is recourse to basic elements of kinetic theory only, being assumed a residual dc electric field and a strong rf drive, capable of sustaining in the resonant region, where waves interact with electrons, a raised fast-electron tail distribution, which becomes an essentially flat plateau in the case of the 1D theory for LHCD. Within the 1D model, particularly suited for LHCD as it solely retains fast-electron dynamics in velocity space parallel to the ambient magnetic field, an H theorem for rf CD is also derived, which is written in different forms, and additional physics is recovered, such as the synergy between the dc and rf power sources, including the rf-induced hot conductivity, as well as the equation for electron-bulk heating. As much as possible 1D results are extended to 2D, to account for ECCD by also considering fast-electron velocity-space dynamics in the direction perpendicular to the magnetic field, which leads to a detailed discussion on how the definition of an rf-induced conductivity may depend on whether one works at constant rf current or power. Moreover, working out the collisional dissipated power and entropy-production rate written in terms of the fast-electron distribution, it

Air core notch-coil magnet with variable geometry for fast-field-cycling NMR.

Science.gov (United States)

Kruber, S; Farrher, G D; Anoardo, E

2015-10-01

In this manuscript we present details on the optimization, construction and performance of a wide-bore (71 mm) α-helical-cut notch-coil magnet with variable geometry for fast-field-cycling NMR. In addition to the usual requirements for this kind of magnets (high field-to-power ratio, good magnetic field homogeneity, low inductance and resistance values) a tunable homogeneity and a more uniform heat dissipation along the magnet body are considered. The presented magnet consists of only one machined metallic cylinder combined with two external movable pieces. The optimal configuration is calculated through an evaluation of the magnetic flux density within the entire volume of interest. The magnet has a field-to-current constant of 0.728 mT/A, allowing to switch from zero to 0.125 T in less than 3 ms without energy storage assistance. For a cylindrical sample volume of 35 cm(3) the effective magnet homogeneity is lower than 130 ppm. Copyright © 2015 Elsevier Inc. All rights reserved.

Tests of stepping as indicators of mobility, balance, and fall risk in balance-impaired older adults.

Science.gov (United States)

Cho, Be-long; Scarpace, Diane; Alexander, Neil B

2004-07-01

To determine the relationships between two tests of stepping ability (the maximal step length (MSL) and rapid step test (RST)) and standard tests of standing balance, gait, mobility, and functional impairment in a group of at-risk older adults. Cross-sectional study. University-based laboratory. One hundred sixty-seven mildly balance-impaired older adults recruited for a balance-training and fall-reduction program (mean age 78, range 65-90). Measures of stepping maximally (MSL, the ability to maximally step out and return to the initial position) and rapidly (RST, the time taken to step out and return in multiple directions as fast as possible); standard measures of balance, gait, and mobility including timed tandem stance (TS), tandem walk (TW, both timing and errors), timed unipedal stance (US), timed up and go (TUG), performance oriented mobility assessment (POMA), and 6-minute walk (SMW); measures of leg strength (peak knee and ankle torque and power at slow and fast speeds); self-report measures of frequent falls (>2 per 12 months), disability (Established Population for Epidemiologic Studies of the Elderly (EPESE) physical function), and confidence to avoid falls (Activity-specific Balance Confidence (ABC) Scale). Spearman and Pearson correlation, intraclass correlation coefficient, logistic regression, and linear regression were used for data analysis. MSL consistently predicted a number of self-report and performance measures at least as well as other standard balance measures. MSL correlations with EPESE physical function, ABC, TUG, and POMA scores; SMW; and peak maximum knee and ankle torque and power were at least as high as those correlations seen with TS, TW, or US. MSL score was associated with the risk of being a frequent faller. In addition, the six MSL directions were highly correlated (up to 0.96), and any one of the leg directions yielded similar relationships with functional measures and a history of falls. Relationships between RST and these

Balancing anisotropic curvature with gauge fields in a class of shear-free cosmological models

Science.gov (United States)

Thorsrud, Mikjel

2018-05-01

We present a complete list of general relativistic shear-free solutions in a class of anisotropic, spatially homogeneous and orthogonal cosmological models containing a collection of n independent p-form gauge fields, where p\\in\\{0, 1, 2, 3\\} , in addition to standard ΛCDM matter fields modelled as perfect fluids. Here a (collection of) gauge field(s) balances anisotropic spatial curvature on the right-hand side of the shear propagation equation. The result is a class of solutions dynamically equivalent to standard FLRW cosmologies, with an effective curvature constant Keff that depends both on spatial curvature and the energy density of the gauge field(s). In the case of a single gauge field (n  =  1) we show that the only spacetimes that admit such solutions are the LRS Bianchi type III, Bianchi type VI0 and Kantowski–Sachs metric, which are dynamically equivalent to open (Keff0 ) FLRW models, respectively. With a collection of gauge fields (n  >  1) also Bianchi type II admits a shear-free solution (Keff>0 ). We identify the LRS Bianchi type III solution to be the unique shear-free solution with a gauge field Hamiltonian bounded from below in the entire class of models.

A technique for determining fast and thermal neutron flux densities in intense high-energy (8-30 MeV) photon fields

International Nuclear Information System (INIS)

Price, K.W.; Holeman, G.R.; Nath, R.

1978-01-01

A technique for measuring fast and thermal neutron fluxes in intense high-energy photon fields has been developed. Samples of phorphorous pentoxide are exposed to a mixed photon-neutron field. The irradiated samples are then dissolved in distilled water and their activation products are counted in a liquid scintillation spectrometer at 95-97% efficiency. The radioactive decay characteristics of the samples are then analyzed to determine fast and thermal neutron fluxes. Sensitivity of this neutron detector to high energy photons has been measured and found to be small. (author)

Maintaining Balance when Looking at a Virtual Reality Three-Dimensional Display of a Field of Moving Dots or at a Virtual Reality Scene.

Science.gov (United States)

Chiarovano, Elodie; de Waele, Catherine; MacDougall, Hamish G; Rogers, Stephen J; Burgess, Ann M; Curthoys, Ian S

2015-01-01

To provide a safe, simple, relatively inexpensive, fast, accurate way of quantifying balance performance either in isolation, or in the face of challenges provided by 3D high definition moving visual stimuli as well as by the proprioceptive challenge from standing on a foam pad. This method uses the new technology of the Wii balance board to measure postural stability during powerful, realistic visual challenges from immersive virtual reality. Present computerized methods for measuring postural stability are large, complex, slow, and expensive, and do not allow for testing the response to realistic visual challenges. Subjects stand on a 6 cm thick, firm, foam pad on a Wii balance board. They wear a fast, high resolution, low persistence, virtual reality head set (Oculus Rift DK2). This allows displays of varying speed, direction, depth, and complexity to be delivered. The subject experiences a visual illusion of real objects fixed relative to the world, and any of these displays can be perturbed in an unpredictable fashion. A special app (BalanceRite) used the same procedures for analyzing postural analysis as used by the Equitest. Four simple "proof of concept" experiments demonstrate that this technique matches the gold standard Equitest in terms of the measurement of postural stability but goes beyond the Equitest by measuring stability in the face of visual challenges, which are so powerful that even healthy subjects fall. The response to these challenges presents an opportunity for predicting falls and for rehabilitation of seniors and patients with poor postural stability. This new method provides a simpler, quicker, cheaper method of measurement than the Equitest. It may provide a new mode of training to prevent falls, by maintaining postural stability in the face of visual and proprioceptive challenges similar to those encountered in life.

Computation of the velocity field and mass balance in the finite-element modeling of groundwater flow

International Nuclear Information System (INIS)

Yeh, G.T.

1980-01-01

Darcian velocity has been conventionally calculated in the finite-element modeling of groundwater flow by taking the derivatives of the computed pressure field. This results in discontinuities in the velocity field at nodal points and element boundaries. Discontinuities become enormous when the computed pressure field is far from a linear distribution. It is proposed in this paper that the finite element procedure that is used to simulate the pressure field or the moisture content field also be applied to Darcy's law with the derivatives of the computed pressure field as the load function. The problem of discontinuity is then eliminated, and the error of mass balance over the region of interest is much reduced. The reduction is from 23.8 to 2.2% by one numerical scheme and from 29.7 to -3.6% by another for a transient problem

Three-dimensional earthward fast flow in the near-Earth plasma sheet in a sheared field: comparisons between simulations and observations

Directory of Open Access Journals (Sweden)

K. Kondoh

2009-06-01

Full Text Available Three-dimensional configuration of earthward fast flow in the near-Earth plasma sheet is studied using three-dimensional magnetohydrodynamics (MHD simulations on the basis of the spontaneous fast reconnection model. In this study, the sheared magnetic field in the plasma sheet is newly considered in order to investigate the effects of it to the earthward fast flow, and the results are discussed in comparison with no-shear simulations. The virtual probes located at different positions in our simulation domain in shear/no-shear cases could explain different behavior of fast flows in the real observations.

BE-FAST (Balance, Eyes, Face, Arm, Speech, Time): Reducing the Proportion of Strokes Missed Using the FAST Mnemonic.

Science.gov (United States)

Aroor, Sushanth; Singh, Rajpreet; Goldstein, Larry B

2017-02-01

The FAST algorithm (Face, Arm, Speech, Time) helps identify persons having an acute stroke. We determined the proportion of patients with acute ischemic stroke not captured by FAST and evaluated a revised mnemonic. Records of all patients admitted to the University of Kentucky Stroke Center between January and December 2014 with a discharge International Classification of Diseases, Ninth Revision, Clinical Modification code for acute ischemic stroke were reviewed. Those misclassified, having missing National Institutes of Health Stroke Scale data, or were comatose or intubated were excluded. Presenting symptoms, demographics, and examination findings based on the National Institutes of Health Stroke Scale data were abstracted. Of 858 consecutive records identified, 736 met inclusion criteria; 14.1% did not have any FAST symptoms at presentation. Of these, 42% had gait imbalance or leg weakness, 40% visual symptoms, and 70% either symptom. With their addition, the proportion of stroke patients not identified was reduced to 4.4% (Pface weakness, arm weakness, or speech impairment on admission examination were considered in addition to a history of FAST symptoms, the proportion missed was reduced to 9.9% (P=0.0010). The proportion of stroke patients not identified was also reduced (2.6%) with the addition of a history of gait imbalance/leg weakness or visual symptoms (P<0.0001). Of patients with ischemic stroke with deficits potentially amenable to acute intervention, 14% are not identified using FAST. The inclusion of gait/leg and visual symptoms leads to a reduction in missed strokes. If validated in a prospective study, a revision of public educational programs may be warranted. © 2017 American Heart Association, Inc.

Particle and energy balance in the SOL generated by a limiter in a RFP plasma

International Nuclear Information System (INIS)

Antoni, V.; Bagatin, M.; Desideri, D.; Serianni, G.

1992-01-01

The plasma outer region of the RFP experiment ETA BETA II has been extensively investigated. In particular by an insertable graphite limiter, instrumented with thermocouples and Langmuir probes, the energy and particle fluxes in the shadow of the limiter have been measured at different insertions. The results are compared with those obtained by small-sized calorimeter/Langmuir probes inserted to investigate, with fine space resolution, the outer region without limiter. Almost 80% of the power to the limiter is estimated to be carried by fast suprathermal electrons flowing along the magnetic field line direction. From an energy balance equation, applied in the SOL locally generated, the connection length of the limiter has been derived. Thus a particle balance has been applied to determine the particle diffusion coefficient at the plasma edge. (orig.)

Highly parallel demagnetization field calculation using the fast multipole method on tetrahedral meshes with continuous sources

Science.gov (United States)

Palmesi, P.; Exl, L.; Bruckner, F.; Abert, C.; Suess, D.

2017-11-01

The long-range magnetic field is the most time-consuming part in micromagnetic simulations. Computational improvements can relieve problems related to this bottleneck. This work presents an efficient implementation of the Fast Multipole Method [FMM] for the magnetic scalar potential as used in micromagnetics. The novelty lies in extending FMM to linearly magnetized tetrahedral sources making it interesting also for other areas of computational physics. We treat the near field directly and in use (exact) numerical integration on the multipole expansion in the far field. This approach tackles important issues like the vectorial and continuous nature of the magnetic field. By using FMM the calculations scale linearly in time and memory.

Effect of crop rotation on soil nutrient balance and weediness in soddy podzolic organic farming fields

Science.gov (United States)

Zarina, Livija; Zarina, Liga

2017-04-01

The nutrient balance in different crop rotations under organic cropping system has been investigated in Latvia at the Institute of Agricultural Resources and Economics since 2006. Latvia is located in a humid and moderate climatic region where the rainfall exceeds evaporation (soil moisture coefficient > 1) and the soil moisture regime is characteristic with percolation. The average annual precipitation is 670-850 mm. The average temperature varies from -6.7° C in January to 16.5 °C in July. The growing season is 175 - 185 days. The most widespread are podzolic soils and mainly they are present in agricultural fields in all regions of Latvia. In a wider sense the goal of the soil management in organic farming is a creation of the biologically active flora and fauna in the soil by maintaining a high level of soil organic matter which is good for crops nutrient balance. Crop rotation is a central component of organic farming systems and has many benefits, including growth of soil microbial activity, which may increase nutrient availability. The aim of the present study was to calculate nutrient balance for each crop in the rotations and average in each rotation. Taking into account that crop rotations can limit build-up of weeds, additionally within the ERA-net CORE Organic Plus transnational programs supported project PRODIVA the information required for a better utilization of crop diversification for weed management in North European organic arable cropping systems was summarized. It was found that the nutrient balance was influenced by nutrients uptake by biomass of growing crops in crop rotation. The number of weeds in the organic farming fields with crop rotation is dependent on the cultivated crops and the succession of crops in the crop rotation.

FAST and SAFE Passive Safety Devices for Sodium-cooled Fast Reactor

Energy Technology Data Exchange (ETDEWEB)

Hartanto, Donny; Kim, Chihyung; Kim, In-Hyung; Kim, Yonghee [KAIST, Daejeon (Korea, Republic of)

2015-05-15

The major factor is the impact of the neutron spectral hardening. The second factor that affects the CVR is reduced capture by the coolant when the coolant voiding occurs. To improve the CVR, many ideas and concepts have been proposed, which include introduction of an internal blanket, spectrum softening, or increasing the neutron leakage. These ideas may reduce the CVR, but they deteriorate the neutron economy. Another potential solution is to adopt a passive safety injection device such as the ARC (autonomous reactivity control) system, which is still under development. In this paper, two new concepts of passive safety devices are proposed. The devices are called FAST (Floating Absorber for Safety at Transient) and SAFE (Static Absorber Feedback Equipment). Their purpose is to enhance the negative reactivity feedback originating from the coolant in fast reactors. SAFE is derived to balance the positive reactivity feedback due to sodium coolant temperature increases. It has been demonstrated that SAFE allows a low-leakage SFR to achieve a self-shutdown and self-controllability even though the generic coolant temperature coefficient is quite positive and the coolant void reactivity can be largely managed by the new FAST device. It is concluded that both FAST and SAFE devices will improve substantially the fast reactor safety and they deserve more detailed investigations.

Effects of resistive magnetic field on fast electron divergence measured in experiment

Czech Academy of Sciences Publication Activity Database

Yang, H.X.; Zhuo, H.B.; Ma, Y.Y.; Xu, H.; Yu, T.P.; Zou, D.B.; Ge, Z.Y.; Xu, B.B.; Zhu, Q.J.; Shao, F.Q.; Borghesi, Marco

2015-01-01

Roč. 57, č. 2 (2015), s. 025011 ISSN 0741-3335 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279 Institutional support: RVO:68378271 Keywords : fast electron * divergence measument * resistive magnetic field * laser-plasma interactions * short-pulse * acceleration Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.404, year: 2015

Fast simulation of non-linear pulsed ultrasound fields using an angular spectrum approach

DEFF Research Database (Denmark)

Du, Yigang; Jensen, Jørgen Arendt

2013-01-01

A fast non-linear pulsed ultrasound field simulation is presented. It is implemented based on an angular spectrum approach (ASA), which analytically solves the non-linear wave equation. The ASA solution to the Westervelt equation is derived in detail. The calculation speed is significantly...... increased compared to a numerical solution using an operator splitting method (OSM). The ASA has been modified and extended to pulsed non-linear ultrasound fields in combination with Field II, where any array transducer with arbitrary geometry, excitation, focusing and apodization can be simulated...... with a center frequency of 5 MHz. The speed is increased approximately by a factor of 140 and the calculation time is 12 min with a standard PC, when simulating the second harmonic pulse at the focal point. For the second harmonic point spread function the full width error is 1.5% at 6 dB and 6.4% at 12 d...

Influence of perturbation velocity on balance control in Parkinson's disease.

Directory of Open Access Journals (Sweden)

Lars B Oude Nijhuis

Full Text Available Underlying somatosensory processing deficits of joint rotation velocities may cause patients with Parkinson's disease (PD to be more unstable for fast rather than slow balance perturbations. Such deficits could lead to reduced proprioceptive amplitude feedback triggered by perturbations, and thereby to smaller or delayed stabilizing postural responses. For this reason, we investigated whether support surface perturbation velocity affects balance reactions in PD patients. We examined postural responses of seven PD patients (OFF medication and eight age-matched controls following backward rotations of a support-surface platform. Rotations occurred at three different speeds: fast (60 deg/s, medium (30 deg/s or slow (3.8 deg/s, presented in random order. Each subject completed the protocol under eyes open and closed conditions. Full body kinematics, ankle torques and the number of near-falls were recorded. Patients were significantly more unstable than controls following fast perturbations (26% larger displacements of the body's centre of mass; P<0.01, but not following slow perturbations. Also, more near-falls occurred in patients for fast rotations. Balance correcting ankle torques were weaker for patients than controls on the most affected side, but were stronger than controls for the least affected side. These differences were present both with eyes open and eyes closed (P<0.01. Fast support surface rotations caused greater instability and discriminated Parkinson patients better from controls than slow rotations. Although ankle torques on the most affected side were weaker, patients partially compensated for this by generating larger than normal stabilizing torques about the ankle joint on the least affected side. Without this compensation, instability may have been greater.

Velocity, safety, or both? How do balance and strength of goal conflicts affect drivers' behaviour, feelings and physiological responses?

Science.gov (United States)

Schmidt-Daffy, Martin; Brandenburg, Stefan; Beliavski, Alina

2013-06-01

Motivational models of driving behaviour agree that choice of speed is modulated by drivers' goals. Whilst it is accepted that some goals favour fast driving and others favour safe driving, little is known about the interplay of these conflicting goals. In the present study, two aspects of this interplay are investigated: the balance of conflict and the strength of conflict. Thirty-two participants completed several simulated driving runs in which fast driving was rewarded with a monetary gain if the end of the track was reached. However, unpredictably, some runs ended with the appearance of a deer. In these runs, fast driving was punished with a monetary loss. The ratio between the magnitudes of gains and losses varied in order to manipulate the balance of conflict. The absolute magnitudes of both gains and losses altered the strength of conflict. Participants drove slower, reported an increase in anxiety-related feelings, and showed indications of physiological arousal if there was more money at stake. In contrast, only marginal effects of varying the ratio between gains and losses were observed. Results confirm that the strength of a safety-velocity conflict is an important determinant of drivers' behaviour, feelings, and physiological responses. The lack of evidence for the balance of conflict playing a role suggests that in each condition, participants subjectively weighted the loss higher than the gain (loss aversion). It is concluded that the interplay of the subjective values that drivers attribute to objective incentives for fast and safe driving is a promising field for future research. Incorporating this knowledge into motivational theories of driving behaviour might improve their contribution to the design of adequate road safety measures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fast directional changes in the geomagnetic field recovered from archaeomagnetism of ancient Israel

Science.gov (United States)

Shaar, R.; Hassul, E.; Raphael, K.; Ebert, Y.; Marco, S.; Nowaczyk, N. R.; Ben-Yosef, E.; Agnon, A.

2017-12-01

Recent archaeomagnetic intensity data from the Levant revealed short-term sub-centennial changes in the geomagnetic field such as `archaeomagnetic jerks' and `geomagnetic spikes'. To fully understand the nature of these fast variations a complementary high-precision time-series of geomagnetic field direction is required. To this end we investigated 35 heat impacted archaeological objects from Israel, including cooking ovens, furnaces, and burnt walls. We combine the new dataset with previously unpublished data and construct the first archaeomagnetic compilation of Israel which, at the moment, consists of a total of 57 directions. Screening out poor quality data leaves 30 acceptable archaeomagnetic directions, 25 of which spanning the period between 1700 BCE to 400 BCE. The most striking result of this dataset is a large directional anomaly with deviation of 20°-25° from geocentric axial dipole direction during the 9th century BCE. This anomaly in field direction is contemporaneous with the Levantine Iron Age Anomaly (LIAA) - a local geomagnetic anomaly over the Levant that was characterized by a high averaged geomagnetic field (nearly twice of today's field) and short decadal-scale geomagnetic spikes.

Correlations at large scales and the onset of turbulence in the fast solar wind

International Nuclear Information System (INIS)

Wicks, R. T.; Roberts, D. A.; Mallet, A.; Schekochihin, A. A.; Horbury, T. S.; Chen, C. H. K.

2013-01-01

We show that the scaling of structure functions of magnetic and velocity fields in a mostly highly Alfvénic fast solar wind stream depends strongly on the joint distribution of the dimensionless measures of cross helicity and residual energy. Already at very low frequencies, fluctuations that are both more balanced (cross helicity ∼0) and equipartitioned (residual energy ∼0) have steep structure functions reminiscent of 'turbulent' scalings usually associated with the inertial range. Fluctuations that are magnetically dominated (residual energy ∼–1), and so have closely anti-aligned Elsasser-field vectors, or are imbalanced (cross helicity ∼1), and so have closely aligned magnetic and velocity vectors, have wide '1/f' ranges typical of fast solar wind. We conclude that the strength of nonlinear interactions of individual fluctuations within a stream, diagnosed by the degree of correlation in direction and magnitude of magnetic and velocity fluctuations, determines the extent of the 1/f region observed, and thus the onset scale for the turbulent cascade.

Balanced Ambipolar Organic Field-Effect Transistors by Polymer Preaggregation.

Science.gov (United States)

Janasz, Lukasz; Luczak, Adam; Marszalek, Tomasz; Dupont, Bertrand G R; Jung, Jaroslaw; Ulanski, Jacek; Pisula, Wojciech

2017-06-21

Ambipolar organic field-effect transistors (OFETs) based on heterojunction active films still suffer from an imbalance in the transport of electrons and holes. This problem is related to an uncontrolled phase separation between the donor and acceptor organic semiconductors in the thin films. In this work, we have developed a concept to improve the phase separation in heterojunction transistors to enhance their ambipolar performance. This concept is based on preaggregation of the donor polymer, in this case poly(3-hexylthiophene) (P3HT), before solution mixing with the small-molecular-weight acceptor, phenyl-C61-butyric acid methyl ester (PCBM). The resulting heterojunction transistor morphology consists of self-assembled P3HT fibers embedded in a PCBM matrix, ensuring balanced mobilities reaching 0.01 cm 2 /V s for both holes and electrons. These are the highest mobility values reported so far for ambipolar OFETs based on P3HT/PCBM blends. Preaggregation of the conjugated polymer before fabricating binary blends can be regarded as a general concept for a wider range of semiconducting systems applicable in organic electronic devices.

Analysis of the stress field in a wedge using the fast expansions with pointwise determined coefficients

Science.gov (United States)

Chernyshov, A. D.; Goryainov, V. V.; Danshin, A. A.

2018-03-01

The stress problem for the elastic wedge-shaped cutter of finite dimensions with mixed boundary conditions is considered. The differential problem is reduced to the system of linear algebraic equations by applying twice the fast expansions with respect to the angular and radial coordinate. In order to determine the unknown coefficients of fast expansions, the pointwise method is utilized. The problem solution derived has explicit analytical form and it’s valid for the entire domain including its boundary. The computed profiles of the displacements and stresses in a cross-section of the cutter are provided. The stress field is investigated for various values of opening angle and cusp’s radius.

Assessment of magnetic field interactions and radiofrequency‐radiation‐induced heating of metallic spinal implants in 7 T field

Science.gov (United States)

Tsukimura, Itsuko; Sasaki, Makoto; Endo, Hirooki; Yamabe, Daisuke; Oikawa, Ryosuke; Doita, Minoru

2017-01-01

ABSTRACT The safety of metallic spinal implants in magnetic resonance imaging (MRI) performed using ultrahigh fields has not been established. Hence, we examined whether the displacement forces caused by a static magnetic field and the heating induced by radiofrequency radiation are substantial for spinal implants in a 7 T field. We investigated spinal rods of various lengths and materials, a screw, and a cross‐linking bridge in accordance with the American Society for Testing and Materials guidelines. The displacement forces of the metallic implants in static 7 T and 3 T static magnetic fields were measured and compared. The temperature changes of the implants during 15‐min‐long fast spin‐echo and balanced gradient‐echo image acquisition sequences were measured in the 7 T field. The deflection angles of the metallic spinal materials in the 7 T field were 5.0–21.0° [median: 6.7°], significantly larger than those in the 3 T field (1.0–6.3° [2.2°]). Among the metallic rods, the cobalt–chrome rods had significantly larger deflection angles (17.8–21.0° [19.8°]) than the pure titanium and titanium alloy rods (5.0–7.7° [6.2°]). The temperature changes of the implants, including the cross‐linked rods, were 0.7–1.0°C [0.8°C] and 0.6–1.0°C [0.7°C] during the fast spin‐echo and balanced gradient‐echo sequences, respectively; these changes were slightly larger than those of the controls (0.4–1.1°C [0.5°C] and 0.3–0.9°C [0.6°C], respectively). All of the metallic spinal implants exhibited small displacement forces and minimal heating, indicating that MRI examinations using 7 T fields may be performed safely on patients with these implants. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:1831–1837, 2017. PMID:27769107

Assessment of magnetic field interactions and radiofrequency-radiation-induced heating of metallic spinal implants in 7 T field.

Science.gov (United States)

Tsukimura, Itsuko; Murakami, Hideki; Sasaki, Makoto; Endo, Hirooki; Yamabe, Daisuke; Oikawa, Ryosuke; Doita, Minoru

2017-08-01

The safety of metallic spinal implants in magnetic resonance imaging (MRI) performed using ultrahigh fields has not been established. Hence, we examined whether the displacement forces caused by a static magnetic field and the heating induced by radiofrequency radiation are substantial for spinal implants in a 7 T field. We investigated spinal rods of various lengths and materials, a screw, and a cross-linking bridge in accordance with the American Society for Testing and Materials guidelines. The displacement forces of the metallic implants in static 7 T and 3 T static magnetic fields were measured and compared. The temperature changes of the implants during 15-min-long fast spin-echo and balanced gradient-echo image acquisition sequences were measured in the 7 T field. The deflection angles of the metallic spinal materials in the 7 T field were 5.0-21.0° [median: 6.7°], significantly larger than those in the 3 T field (1.0-6.3° [2.2°]). Among the metallic rods, the cobalt-chrome rods had significantly larger deflection angles (17.8-21.0° [19.8°]) than the pure titanium and titanium alloy rods (5.0-7.7° [6.2°]). The temperature changes of the implants, including the cross-linked rods, were 0.7-1.0°C [0.8°C] and 0.6-1.0°C [0.7°C] during the fast spin-echo and balanced gradient-echo sequences, respectively; these changes were slightly larger than those of the controls (0.4-1.1°C [0.5°C] and 0.3-0.9°C [0.6°C], respectively). All of the metallic spinal implants exhibited small displacement forces and minimal heating, indicating that MRI examinations using 7 T fields may be performed safely on patients with these implants. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:1831-1837, 2017. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society.

Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field.

Science.gov (United States)

Liu, Chong; Dobrynin, Danil; Fridman, Alexander

2014-06-25

In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge.

Radial distributions of magnetic field strength in the solar corona as derived from data on fast halo CMEs

Science.gov (United States)

Fainshtein, Victor; Egorov, Yaroslav

2018-03-01

In recent years, information about the distance between the body of rapid coronal mass ejection (CME) and the associated shock wave has been used to measure the magnetic field in the solar corona. In all cases, this technique allows us to find coronal magnetic field radial profiles B(R) applied to the directions almost perpendicular to the line of sight. We have determined radial distributions of magnetic field strength along the directions close to the Sun-Earth axis. For this purpose, using the "ice-cream cone" model and SOHO/LASCO data, we found 3D characteristics for fast halo coronal mass ejections (HCMEs) and for HCME-related shocks. With these data, we managed to obtain the B(R) distributions as far as ≈43 solar radii from the Sun's center, which is approximately twice as far as those in other studies based on LASCO data. We have concluded that to improve the accuracy of this method for finding the coronal magnetic field we should develop a technique for detecting CME sites moving in the slow and fast solar wind. We propose a technique for selecting CMEs whose central (paraxial) part actually moves in the slow wind.

Experiments and numerical modeling of fast flowing liquid metal thin films under spatially varying magnetic field conditions

Science.gov (United States)

Narula, Manmeet Singh

Innovative concepts using fast flowing thin films of liquid metals (like lithium) have been proposed for the protection of the divertor surface in magnetic fusion devices. However, concerns exist about the possibility of establishing the required flow of liquid metal thin films because of the presence of strong magnetic fields which can cause flow disrupting MHD effects. A plan is underway to design liquid lithium based divertor protection concepts for NSTX, a small spherical torus experiment at Princeton. Of these, a promising concept is the use of modularized fast flowing liquid lithium film zones, as the divertor (called the NSTX liquid surface module concept or NSTX LSM). The dynamic response of the liquid metal film flow in a spatially varying magnetic field configuration is still unknown and it is suspected that some unpredicted effects might be lurking. The primary goal of the research work being reported in this dissertation is to provide qualitative and quantitative information on the liquid metal film flow dynamics under spatially varying magnetic field conditions, typical of the divertor region of a magnetic fusion device. The liquid metal film flow dynamics have been studied through a synergic experimental and numerical modeling effort. The Magneto Thermofluid Omnibus Research (MTOR) facility at UCLA has been used to design several experiments to study the MHD interaction of liquid gallium films under a scaled NSTX outboard divertor magnetic field environment. A 3D multi-material, free surface MHD modeling capability is under development in collaboration with HyPerComp Inc., an SBIR vendor. This numerical code called HIMAG provides a unique capability to model the equations of incompressible MHD with a free surface. Some parts of this modeling capability have been developed in this research work, in the form of subroutines for HIMAG. Extensive code debugging and benchmarking exercise has also been carried out. Finally, HIMAG has been used to study the

Deprivation and food access and balance in Saskatoon, Saskatchewan.

Science.gov (United States)

Cushon, J; Creighton, T; Kershaw, T; Marko, J; Markham, T

2013-06-01

We explored food access and balance in Saskatoon, Saskatchewan, Canada in relation to material and social deprivation. We mapped the location of all large supermarkets and fast food retailers in Saskatoon. Supermarket accessibility index scores and food balance scores were compared to material and social deprivation indexes to determine significant associations. Our results indicate that the poorest access to supermarkets occurred in areas west of the South Saskatchewan River and also in suburban areas around the perimeter of the city. Areas west of the river are some of the most deprived areas in the city. Saskatoon's mean food balance ratio of 2.3 indicates that access favours fast food. However, we did not find a clear pattern or clear socio-economic gradient for most measures. This study highlights the importance of contextual studies of food access. This study also highlighted a number of other issues that should be explored in the Saskatoon context such as individual-level food consumption patterns, mobility, temporal dimensions of food access and economic access as well as interventions that could improve food access in the city.

Microchip capillary gel electrophoresis using programmed field strength gradients for the ultra-fast analysis of genetically modified organisms in soybeans.

Science.gov (United States)

Kim, Yun-Jeong; Chae, Joon-Seok; Chang, Jun Keun; Kang, Seong Ho

2005-08-12

We have developed a novel method for the ultra-fast analysis of genetically modified organisms (GMOs) in soybeans by microchip capillary gel electrophoresis (MCGE) using programmed field strength gradients (PFSG) in a conventional glass double-T microchip. Under the programmed electric field strength and 0.3% poly(ethylene oxide) sieving matrix, the GMO in soybeans was analyzed within only 11 s of the microchip. The MCGE-PFSG method was a program that changes the electric field strength during GMO analysis, and was also applied to the ultra-fast analysis of PCR products. Compared to MCGE using a conventional and constantly applied electric field, the MCGE-PFSG analysis generated faster results without the loss of resolving power and reproducibility for specific DNA fragments (100- and 250-bp DNA) of GM-soybeans. The MCGE-PFSG technique may prove to be a new tool in the GMO analysis due to its speed, simplicity, and high efficiency.

Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest China

Science.gov (United States)

Ming, G.

2017-12-01

Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest ChinaGuanghui Ming1, Fuqiang Tian1*, Hongchang Hu11State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China,Abstracts: Agricultural ecosystems have the potential to offset rising CO2 concentration in the atmosphere but the potential is often altered by agricultural management. Plastic film mulching and drip irrigation (PMDI) have been widespread for saving water and improving crop yield worldwide. To comprehensively assess the carbon balance and to detect the controlling factors of the carbon flux in a PMDI cotton field, experiments combining eddy covariance (EC) system, chamber method and crop sampling were implemented in an arid oasis of Xinjiang from the year 2012 to 2016. The annual net ecosystem exchange (NEE) was -250.18 ± 80.41 g C m-2 in the five years, which indicated that the filed was a much stronger carbon sink. After removal of the harvest of cotton as seed oil (Ch) of 108.81±7.57 g C m-2, the field was still a moderate carbon sink with net biome productivity (NBP) of 141.37±73.7 g C m-2. Soil temperature can explain 82% of seasonal variation of nighttime NEE while PAR can explain 36-81% of daytime NEE varying with crop development and photosynthetic activity. NEE was separated into total ecosystem respiration (Reco, 1214.20±144.42 g C m-2) and gross primary productivity (GPP, 1464.38±122.78 g C m-2). Interannual Reco changed more drastically than GPP and respiration may be the main determinant of carbon balance in the PMDI field. Seasonal NPP measured by cop sampling method (NPPCS) agreed well with NPP calculated with EC (NPPEC), with the annual NPP of 708.86 ± 52.26 g C m-2, which indicated that our carbon flux measurements and separating methods reasonable. The PMDI cotton field induced more GPP and Reco than other croplands with larger light use efficiency (LUE) but relatively

The effects of moderate fatigue on dynamic balance control and attentional demands

Directory of Open Access Journals (Sweden)

Teasdale Normand

2006-09-01

Full Text Available Abstract Background During daily activities, the active control of balance often is a task per se (for example, when standing in a moving bus. Other constraints like fatigue can add to the complexity of this balance task. In the present experiment, we examined how moderate fatigue induced by fast walking on a treadmill challenged dynamic balance control. We also examined if the attentional demands for performing the balance task varied with fatigue. Methods Subjects (n = 10 performed simultaneously a dynamic balance control task and a probe reaction time task (RT (serving as an indicator of attentional demands before and after three periods of moderate fatigue (fast walking on a treadmill. For the balance control task, the real-time displacement of the centre of pressure (CP was provided on a monitor placed in front of the subject, at eye level. Subjects were asked to keep their CP within a target (moving box moving upward and downward on the monitor. The tracking performance was measured (time spent outside the moving box and the CP behavior analyzed (mean CP speed and mean frequency of the CP velocity. Results Moderate fatigue led to an immediate decrement of the performance on the balance control task; increase of the percentage of time spent outside the box and increase of the mean CP speed. Across the three fatigue periods, subjects improved their tracking performance and reduced their mean CP speed. This was achieved by increasing their frequency of actions; mean frequency of the CP velocity were higher for the fatigue periods than for the no fatigue periods. Fatigue also induced an increase in the attentional demands suggesting that more cognitive resources had to be allocated to the balance task with than without fatigue. Conclusion Fatigue induced by fast walking had an initial negative impact on the control of balance. Nonetheless, subjects were able to compensate the effect of the moderate fatigue by increasing the frequency of

Harmonic balancing approach to nonlinear oscillations of a punctual charge in the electric field of charged ring

International Nuclear Information System (INIS)

Belendez, A.; Fernandez, E.; Rodes, J.J.; Fuentes, R.; Pascual, I.

2009-01-01

The harmonic balance method is used to construct approximate frequency-amplitude relations and periodic solutions to an oscillating charge in the electric field of a ring. By combining linearization of the governing equation with the harmonic balance method, we construct analytical approximations to the oscillation frequencies and periodic solutions for the oscillator. To solve the nonlinear differential equation, firstly we make a change of variable and secondly the differential equation is rewritten in a form that does not contain the square-root expression. The approximate frequencies obtained are valid for the complete range of oscillation amplitudes and excellent agreement of the approximate frequencies and periodic solutions with the exact ones are demonstrated and discussed

Effects of Ramadan Gasting on Postural Balance and Attentional Capacities in Elderly People.

Science.gov (United States)

Laatar, R; Borji, R; Baccouch, R; Zahaf, F; Rebai, H; Sahli, S

2016-01-01

To evaluate the effects of Ramadan fasting on postural balance and attentional capacities in older adults. the Neurophysiology department of a University Hospital. Fifteen males aged between 65 and 80 years were asked to perform a postural balance protocol and a simple reaction time (SRT) test in four testing phases: one week before Ramadan (BR), during the second (SWR) and the fourth week of Ramadan (FWR) and 3 weeks after Ramadan (AR). Postural balance measurements were recorded in the bipedal stance in four different conditions: firm surface/eyes open (EO), firm surface/eyes closed (EC), foam surface/EO and foam surface/EC using a force platform. Results of the present study demonstrated that center of pressure (CoP) mean velocity (CoPVm), medio-lateral length (CoPLX) and antero-posterior length (CoPLY) were significantly higher during the SWR than BR. Likewise, values of CoPVm and CoPLX increased significantly during the FWR compared to BR. The CoPLX decreased significantly in the FWR compared to the SWR. Values of CoPVm and CoPLX were significantly higher AR in comparison with BR. In addition, SRT values increased significantly during the SWR and the FWR than BR. Ramadan fasting affects postural balance and attentional capacities in the elderly mainly in the SWR and it may, therefore, increase the risk of fall and fall-related injuries. More than three weeks are needed for older adults to recover postural balance impairment due to Ramadan fasting.

Energy consumption in Hodgkin–Huxley type fast spiking neuron model exposed to an external electric field

Directory of Open Access Journals (Sweden)

K. Usha

2016-09-01

Full Text Available This paper evaluates the change in metabolic energy required to maintain the signalling activity of neurons in the presence of an external electric field. We have analysed the Hodgkin–Huxley type conductance based fast spiking neuron model as electrical circuit by changing the frequency and amplitude of the applied electric field. The study has shown that, the presence of electric field increases the membrane potential, electrical energy supply and metabolic energy consumption. As the amplitude of applied electric field increases by keeping a constant frequency, the membrane potential increases and consequently the electrical energy supply and metabolic energy consumption increases. On increasing the frequency of the applied field, the peak value of membrane potential after depolarization gradually decreases as a result electrical energy supply decreases which results in a lower rate of hydrolysis of ATP molecules.

Eigenmode field structure of the fast magnetosonic wave in a Tokamak and loading impedance of coupling structures

International Nuclear Information System (INIS)

Adam, J.; Jacquinot, J.

1977-04-01

Detailed calculations concerning the field structure and excitation of the fast magnetosonic wave are presented keeping in mind RF heating of a Tokamak near the ion cyclotron harmonic. The new contributions are - a discussion of the cylindrical problem in an inhomogeneous plasma including surface waves and the splitting of the eigenmodes by the poloidal field - a calculation of the field structure in the toroidal cavity resonator and the application to mode tracking - a formulation of the loading impedance of various coupling structures: array of coils in the low frequency limit or transmission lines in the high frequency case

Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field

Science.gov (United States)

Liu, Chong; Dobrynin, Danil; Fridman, Alexander

2014-01-01

In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge. PMID:25071294

Design of a fast runback feature for PRISM control

International Nuclear Information System (INIS)

Wagner, W.K.; Rhow, S.K.; Daniel, W.R.; Dayal, Y.; Gaubatz, D.C.

1988-01-01

The nine power reactor inherently safe modules (PRISM) are controlled and their operation coordinated by a hierarchical, distributed, digital plant control system (PCS). This paper describes the fast runback features of the PCS. Fast runback consists of PCS directed reactor module shutdown with accompanying reductions of coolant flows. Analyses have shown that the PCS fast runback adequately terminates duty cycle events initiated in the balance of plant and the steam generating system, results in lower thermal shock to the reactor than scram, and reduces the number of scrams by approximately a factor of five

Integral test of JENDL dosimetry file using fast neutron field in the Experimental Fast Reactor JOYO

International Nuclear Information System (INIS)

Aoyama, Takafumi; Sekine, Takashi

1999-09-01

In order to evaluate the applicability of the JENDL dosimetry file, an integral test using a fast neutron spectrum field in the Experimental Fast Reactor JOYO Mark-II core was performed. The dosimeter set consisting of eight reactions of 46 Ti(n,p) 46 Sc, 54 Fe(n,p) 54 Mn, 58 Fe(n,γ) 59 Fe, 58 Ni(n,p) 58 Co, 59 Co(n,γ) 60 Co, 63 Cu(n,α) 60 Co, 238 U fission and 237 Np fission was irradiated for approximately 30 days near the core center of the JOYO Mk-II. Neutron flux at the dosimeter position was calculated using the two dimensional discrete ordinate transport code 'DORT'. The core configuration was modeled in XY geometry, and the 100 group cross section set of JSD-J2 / JFT-J2, which was processed from JENDL-2, was utilized. The absolute value of neutron flux was normalized so that the 235 U fission rate using the calculated neutron spectrum agreed with the measured reaction rate. The 103 group cross section data were processed by 'NJOY' code for nuclides to be used in the JOYO dosimetry. As the results of integral test for JENDL/D-99 (new file) and JENDL/D-91 (previous file), calculated values by JENDL/D-99 agreed well with the experimental values, and the C/E ratios ranged from 0.95 to 1.22. By comparing the results between JENDL/D-99 and JENDL/D-91, small differences exist, except for 58 Fe(n, γ) 59 Fe reaction, which was improved significantly in JENDL/D-99. (author)

Islamic fasting and multiple sclerosis

Science.gov (United States)

2014-01-01

Background Month-long daytime Ramadan fasting pose s major challenges to multiple sclerosis (MS) patients in Muslim countries. Physicians should have practical knowledge on the implications of fasting on MS. We present a summary of database searches (Cochrane Database of Systematic Reviews, PubMed) and a mini-symposium on Ramadan fasting and MS. In this symposium, we aimed to review the effect of fasting on MS and suggest practical guidelines on management. Discussion In general, fasting is possible for most stable patients. Appropriate amendment of drug regimens, careful monitoring of symptoms, as well as providing patients with available evidence on fasting and MS are important parts of management. Evidence from experimental studies suggests that calorie restriction before disease induction reduces inflammation and subsequent demyelination and attenuates disease severity. Fasting does not appear to have unfavorable effects on disease course in patients with mild disability (Expanded Disability Status Scale (EDSS) score ≤3). Most experts believed that during fasting (especially in summer), some MS symptoms (fatigue, fatigue perception, dizziness, spasticity, cognitive problems, weakness, vision, balance, gait) might worsen but return to normal levels during feasting. There was a general consensus that fasting is not safe for patients: on high doses of anti-convulsants, anti-spastics, and corticosteroids; with coagulopathy or active disease; during attacks; with EDSS score ≥7. Summary These data suggest that MS patients should have tailored care. Fasting in MS patients is a challenge that is directly associated with the spiritual belief of the patient. PMID:24655543

Balance velocities of the Greenland ice sheet

DEFF Research Database (Denmark)

Joughin, I.; Fahnestock, M.; Ekholm, Simon

1997-01-01

We present a map of balance velocities for the Greenland ice sheet. The resolution of the underlying DEM, which was derived primarily from radar altimetery data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail......, the balance map is useful for ice-sheet modelling, mass balance studies, and field planning....

Electric power balance sheet 2013

International Nuclear Information System (INIS)

2014-01-01

The mission of RTE, the French electricity Transportation grid, a public service assignment, is to balance the electricity supply and demand in real time. This report presents RTE's technical results for the year 2013: stabilisation of the electricity consumption in France, high level of hydropower generation, fast evolution of the European power network, electricity markets in a transition situation, adaptation of RTE's network to the evolutions of the energy system

Smooth and fast versus instantaneous quenches in quantum field theory

Science.gov (United States)

Das, Sumit R.; Galante, Damián A.; Myers, Robert C.

2015-08-01

We examine in detail the relationship between smooth fast quantum quenches, characterized by a time scale δ t, and instantaneous quenches, within the framework of exactly solvable mass quenches in free scalar field theory. Our earlier studies [1, 2] highlighted that the two protocols remain distinct in the limit δ t → 0 because of the relation of the quench rate to the UV cut-off, i.e., 1 /δ t ≪ Λ always holds in the fast smooth quenches while 1 /δ t ˜ Λ for instantaneous quenches. Here we study UV finite quantities like correlators at finite spatial distances and the excess energy produced above the final ground state energy. We show that at late times and large distances (compared to the quench time scale) the smooth quench correlator approaches that for the instantaneous quench. At early times, we find that for small spatial separation and small δ t, the correlator scales universally with δ t, exactly as in the scaling of renormalized one point functions found in earlier work. At larger separation, the dependence on δ t drops out. The excess energy density is finite (for finite mδ t) and scales in a universal fashion for all d. However, the scaling behaviour produces a divergent result in the limit mδ t → 0 for d ≥ 4, just as in an instantaneous quench, where it is UV divergent for d ≥ 4. We argue that similar results hold for arbitrary interacting theories: the excess energy density produced is expected to diverge for scaling dimensions Δ > d/2.

Radial distributions of magnetic field strength in the solar corona as derived from data on fast halo CMEs

Directory of Open Access Journals (Sweden)

Fainshtein V.G.

2018-03-01

Full Text Available In recent years, information about the distance between the body of rapid coronal mass ejection (CME and the associated shock wave has been used to measure the magnetic field in the solar corona. In all cases, this technique allows us to find coronal magnetic field radial profiles B(R applied to the directions almost perpendicular to the line of sight. We have determined radial distributions of magnetic field strength along the directions close to the Sun–Earth axis. For this purpose, using the “ice-cream cone” model and SOHO/LASCO data, we found 3D characteristics for fast halo coronal mass ejections (HCMEs and for HCME-related shocks. With these data we managed to obtain the B(R distributions as far as ≈43 solar radii from the Sun's center, which is approximately twice as far as those in other studies based on LASCO data. We have concluded that to improve the accuracy of this method for finding the coronal magnetic field we should develop a technique for detecting CME parts moving in the slow and fast solar wind. We propose a technique for selecting CMEs whose central (paraxial part actually moves in the slow wind.

Fast fluence measurement for JOYO irradiation field using niobium dosimeter

International Nuclear Information System (INIS)

Ito, Chikara

2004-03-01

Neutron fluence and spectrum are key parameters in various irradiation tests and material surveillance tests so they need to be evaluated accurately. The reactor dosimetry test has been conducted by the multiple foil activation method, and a niobium dosimeter has been developed for measurement of fast neutron fluence in the experimental fast reactor JOYO. The inelastic scattering reaction of 93 Nb has a low threshold energy, about 30 keV, and the energy distribution of reaction cross section is similar to the displacement cross section for iron. Therefore, a niobium dosimeter is suitable for evaluation of the fast neutron fluence and the displacement per atom for iron. Moreover, a niobium dosimeter is suited to measure neutron fluence in long-term irradiation test because 93 Nb, which is produced by the reaction, has a long half-life (16.4 years). This study established a high precision measurement technique using the niobium reaction rate. The effect of self-absorption was decreased by the solution and evaporation to dryness of niobium dosimeter. The dosimeter weight was precisely measured using the inductively coupled plasma mass spectrometer. This technique was applied to JOYO dosimetry. The fast neutron fluences (E > 0.1 MeV) found by measuring the reaction rate in the niobium dosimeter were compared with the values evaluated using the multiple foil activation method. The ratio of measured fast neutron fluences by means of niobium dosimeter and multiple foil activation method range from 0.97 to 1.03 and agree within the experimental uncertainty. The measurement errors of fast neutron fluence by niobium dosimeter range from 4.5% (fuel region) to 10.1% (in-vessel storage rack). As a result of this study, the high precision measurement of fast neutron fluence by niobium dosimeters was confirmed. The accuracy of fast reactor dosimetry will be improved by application of niobium dosimeters to the irradiation tests in the JOYO MK-III core. (author)

Field test and evaluation of the passive neutron coincidence collar for prototype fast reactor fuel subassemblies

International Nuclear Information System (INIS)

Menlove, H.O.; Keddar, A.

1982-08-01

The passive neutron Coincidence Collar, which was developed for the verification of plutonium content in fast reactor fuel subassemblies, has been field tested using Prototype Fast Reactor fuel. For passive applications, the system measures the 240 Pu-effective mass from the spontaneous fission rate, and in addition, a self-interrogation technique is used to determine the fissile content in the subassembly. Both the passive and active modes were evaluated at the Windscale Works in the United Kingdom. The results of the tests gave a standard deviation 0.75% for the passive count and 3 to 7% for the active measurement for a 1000-s counting time. The unit will be used in the future for the verification of plutonium in fresh fuel assemblies

Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

Energy Technology Data Exchange (ETDEWEB)

Yikilmaz, Ali; Koc, Ali; Coskun, Abdulhakim (Dept. of Radiology, Erciyes Medical School, Kayseri (Turkey)); Ozturk, Mustafa K (Dept. of Pediatric Infectious Diseases, Erciyes Medical School, Kayseri (Turkey)); Mulkern, Robert V; Lee, Edward Y (Dept. of Radiology and Dept. of Medicine, Pulmonary Div., Children' s Hospital Boston and Harvard Medical School, Boston (United States)), email: Edward.lee@childrens.harvard.edu

2011-10-15

Background Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children. Purpose To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs. Material and Methods This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years +- 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weighted B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics. Results All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30). Conclusion MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children

Very fast isotopic and mass balance calculations used for strategic planing of the nuclear fuel cycle

International Nuclear Information System (INIS)

Marguet, S.D.

1993-01-01

Owing to the prevalence in France of nuclear generated electricity, the french utility, EDF focuses much research on fuel cycle strategy. In this context, analysis of scenarios combining problems related to planning and economics, but also reactor physics, necessitate a relatively thorough understanding of fuel response to irradiation. The main purpose of the fuel strategy program codes is to predict mass balance modifications with time for the main actinides involved in the cycle, including the minor actinides associated with the current back end fuel cycle key issues. Considering the large number of calculations performed by a strategy code in an iterative process covering a range of about a hundred years, it was important to develop basic computation modules for both the ''reactor'' and ''fabrication'' items. These had to be high speed routines, but on an accuracy level compatible with the strategy code efficiency. At the end of 1992, the EDF Research and Development Division (EDF/DER) developed a very simple, extremely fast method of calculating transuranian isotope masses. This approach, which resulted in the STRAPONTIN software, considerably increased the scope of the EDF/DER fuel strategy code TIRELIRE without undue impairment of machine time requirements for a scenario. (author). 2 figs., 2 tabs., 3 refs

Bias correction for the estimation of sensitivity indices based on random balance designs

International Nuclear Information System (INIS)

Tissot, Jean-Yves; Prieur, Clémentine

2012-01-01

This paper deals with the random balance design method (RBD) and its hybrid approach, RBD-FAST. Both these global sensitivity analysis methods originate from Fourier amplitude sensitivity test (FAST) and consequently face the main problems inherent to discrete harmonic analysis. We present here a general way to correct a bias which occurs when estimating sensitivity indices (SIs) of any order – except total SI of single factor or group of factors – by the random balance design method (RBD) and its hybrid version, RBD-FAST. In the RBD case, this positive bias has been recently identified in a paper by Xu and Gertner [1]. Following their work, we propose a bias correction method for first-order SIs estimates in RBD. We then extend the correction method to the SIs of any order in RBD-FAST. At last, we suggest an efficient strategy to estimate all the first- and second-order SIs using RBD-FAST. - Highlights: ► We provide a bias correction method for the global sensitivity analysis methods: RBD and RBD-FAST. ► In RBD, first-order sensitivity estimates are corrected. ► In RBD-FAST, sensitivity indices of any order and closed sensitivity indices are corrected. ► We propose an efficient strategy to estimate all the first- and second-order indices of a model.

Mean field theory for a balanced hypercolumn model of orientation selectivity in primary visual cortex

CERN Document Server

Lerchner, A; Hertz, J; Ahmadi, M

2004-01-01

We present a complete mean field theory for a balanced state of a simple model of an orientation hypercolumn. The theory is complemented by a description of a numerical procedure for solving the mean-field equations quantitatively. With our treatment, we can determine self-consistently both the firing rates and the firing correlations, without being restricted to specific neuron models. Here, we solve the analytically derived mean-field equations numerically for integrate-and-fire neurons. Several known key properties of orientation selective cortical neurons emerge naturally from the description: Irregular firing with statistics close to -- but not restricted to -- Poisson statistics; an almost linear gain function (firing frequency as a function of stimulus contrast) of the neurons within the network; and a contrast-invariant tuning width of the neuronal firing. We find that the irregularity in firing depends sensitively on synaptic strengths. If Fano factors are bigger than 1, then they are so for all stim...

High Performance Ambipolar Diketopyrrolopyrrole-Thieno[3,2-b]thiophene Copolymer Field-Effect Transistors with Balanced Hole and Electron Mobilities

DEFF Research Database (Denmark)

Chen, Zhuoying; Lee, Mi Jung; Ashraf, Raja Shahid

2012-01-01

Ambipolar OFETs with balanced hole and electron field-effect mobilities both exceeding 1 cm2 V−1 s−1 are achieved based on a single-solution-processed conjugated polymer, DPPT-TT, upon careful optimization of the device architecture, charge injection, and polymer processing. Such high-performance...

Self-consistent analysis of radial electric field and fast ion losses in CHS Torsatron/Heliotron

International Nuclear Information System (INIS)

Sanuki, H.; Itoh, K.; Itoh, S.

1992-09-01

A self-consistent analysis is developed to determine the radial electric field and loss cone boundary in Torsatron/Heliotron plasmas under the influence of non-classical ion losses such as the loss cone loss ans charge exchange loss of fast ions with neutrals. Analysis is applied to the NBI heated plasmas in the Compact Helical System (CHS) device. Comparison is made between theoretical results and experimental observations. The increased ion particle losses caused by the orbit loss and charge exchange loss with neutrals make the radial electric field more negative than the value of purely neoclassical calculation. The partition of the injection energy among the shine through, direct orbit loss, change exchange loss and bulk heating is evaluated by using the self-consistent electric field profile. On-going experiments in the CHS device are briefly introduced. (author)

Balance training with multi-task exercises improves fall-related self-efficacy, gait, balance performance and physical function in older adults with osteoporosis: a randomized controlled trial.

Science.gov (United States)

Halvarsson, Alexandra; Franzén, Erika; Ståhle, Agneta

2015-04-01

To evaluate the effects of a balance training program including dual- and multi-task exercises on fall-related self-efficacy, fear of falling, gait and balance performance, and physical function in older adults with osteoporosis with an increased risk of falling and to evaluate whether additional physical activity would further improve the effects. Randomized controlled trial, including three groups: two intervention groups (Training, or Training+Physical activity) and one Control group, with a 12-week follow-up. Stockholm County, Sweden. Ninety-six older adults, aged 66-87, with verified osteoporosis. A specific and progressive balance training program including dual- and multi-task three times/week for 12 weeks, and physical activity for 30 minutes, three times/week. Fall-related self-efficacy (Falls Efficacy Scale-International), fear of falling (single-item question - 'In general, are you afraid of falling?'), gait speed with and without a cognitive dual-task at preferred pace and fast walking (GAITRite®), balance performance tests (one-leg stance, and modified figure of eight), and physical function (Late-Life Function and Disability Instrument). Both intervention groups significantly improved their fall-related self-efficacy as compared to the controls (p ≤ 0.034, 4 points) and improved their balance performance. Significant differences over time and between groups in favour of the intervention groups were found for walking speed with a dual-task (p=0.003), at fast walking speed (p=0.008), and for advanced lower extremity physical function (p=0.034). This balance training program, including dual- and multi-task, improves fall-related self-efficacy, gait speed, balance performance, and physical function in older adults with osteoporosis. © The Author(s) 2014.

Smooth and fast versus instantaneous quenches in quantum field theory

International Nuclear Information System (INIS)

Das, Sumit R.; Galante, Damián A.; Myers, Robert C.

2015-01-01

We examine in detail the relationship between smooth fast quantum quenches, characterized by a time scale δt, and instantaneous quenches, within the framework of exactly solvable mass quenches in free scalar field theory. Our earlier studies http://dx.doi.org/10.1103/PhysRevLett.112.171601 and http://dx.doi.org/10.1007/JHEP02(2015)167 highlighted that the two protocols remain distinct in the limit δt→0 because of the relation of the quench rate to the UV cut-off, i.e., 1/δt≪Λ always holds in the fast smooth quenches while 1/δt∼Λ for instantaneous quenches. Here we study UV finite quantities like correlators at finite spatial distances and the excess energy produced above the final ground state energy. We show that at late times and large distances (compared to the quench time scale) the smooth quench correlator approaches that for the instantaneous quench. At early times, we find that for small spatial separation and small δt, the correlator scales universally with δt, exactly as in the scaling of renormalized one point functions found in earlier work. At larger separation, the dependence on δt drops out. The excess energy density is finite (for finite mδt) and scales in a universal fashion for all d. However, the scaling behaviour produces a divergent result in the limit mδt→0 for d≥4, just as in an instantaneous quench, where it is UV divergent for d≥4. We argue that similar results hold for arbitrary interacting theories: the excess energy density produced is expected to diverge for scaling dimensions Δ>d/2.

Balancing Near-Field Enhancement, Absorption, and Scattering for Effective Antenna-Reactor Plasmonic Photocatalysis.

Science.gov (United States)

Li, Kun; Hogan, Nathaniel J; Kale, Matthew J; Halas, Naomi J; Nordlander, Peter; Christopher, Phillip

2017-06-14

Efficient photocatalysis requires multifunctional materials that absorb photons and generate energetic charge carriers at catalytic active sites to facilitate a desired chemical reaction. Antenna-reactor complexes are an emerging multifunctional photocatalytic structure where the strong, localized near field of the plasmonic metal nanoparticle (e.g., Ag) is coupled to the catalytic properties of the nonplasmonic metal nanoparticle (e.g., Pt) to enable chemical transformations. With an eye toward sustainable solar driven photocatalysis, we investigate how the structure of antenna-reactor complexes governs their photocatalytic activity in the light-limited regime, where all photons need to be effectively utilized. By synthesizing core@shell/satellite (Ag@SiO 2 /Pt) antenna-reactor complexes with varying Ag nanoparticle diameters and performing photocatalytic CO oxidation, we observed plasmon-enhanced photocatalysis only for antenna-reactor complexes with antenna components of intermediate sizes (25 and 50 nm). Optimal photocatalytic performance was shown to be determined by a balance between maximized local field enhancements at the catalytically active Pt surface, minimized collective scattering of photons out of the catalyst bed by the complexes, and minimal light absorption in the Ag nanoparticle antenna. These results elucidate the critical aspects of local field enhancement, light scattering, and absorption in plasmonic photocatalyst design, especially under light-limited illumination conditions.

Decreased insulin response in dairy cows following a four-day fast to induce hepatic lipidosis.

Science.gov (United States)

Oikawa, S; Oetzel, G R

2006-08-01

Negative energy balance has been implicated in the development of fatty liver, insulin resistance, and impaired health in dairy cows. A 4-d fasting model previously was reported to increase liver triglycerides more than 2.5-fold. The purpose of the present study was to evaluate insulin response in this fasting model. Nonlactating, nonpregnant Holstein cows were fasted for 4 d (6 cows) or fed continuously as control cows (4 cows). Samples were collected 5 d before fasting, during fasting, and immediately after the 4-d fast, 8 d after the fast, and 16 d after the fast. Fasted cows had greater liver triglyceride content (49.4 vs. 16.2 mg/g, wet-weight basis) at the end of the fasting period compared with control cows. Fasted cows also had increased plasma nonesterified fatty acid (NEFA) concentrations (1.24 vs. 0.21 mmol/L) and increased plasma beta-hydroxybutyrate (BHBA) concentrations at the end of the fasting period. Liver triglyceride, plasma NEFA, and plasma BHBA in fasted cows returned to prefasting concentrations by the end of the experiment. Plasma glucose concentrations were not affected by fasting. Plasma insulin concentrations were decreased (6.3 vs. 14.1 microU/mL) and insulin-stimulated blood glucose reduction was decreased (24.9 vs. 48.6%) in the fasted cows compared with control cows at the end of the fast, indicating reduced insulin response. Insulin response was negatively correlated with plasma NEFA and liver triglycerides. Decreased insulin response may be an important complication of negative energy balance and hepatic lipidosis.

The deficit of current account balances and budgetary deficit in countries in transition

OpenAIRE

Sandra Krtalic; Ines Kersan

1998-01-01

In restructuring process of their own economies, countries in transition deal with many common problems. One of the problems that transition brought to those countries is deficit in current account, as well as budget deficit. Deficits represent limit to a healthy and fast economic development and progress. Balance in balance of payments, as well as balanced budget are components of macroeconomic system. The authors will give an review of activities on deficits in countries in transition, and ...

A fast point-cloud computing method based on spatial symmetry of Fresnel field

Science.gov (United States)

Wang, Xiangxiang; Zhang, Kai; Shen, Chuan; Zhu, Wenliang; Wei, Sui

2017-10-01

Aiming at the great challenge for Computer Generated Hologram (CGH) duo to the production of high spatial-bandwidth product (SBP) is required in the real-time holographic video display systems. The paper is based on point-cloud method and it takes advantage of the propagating reversibility of Fresnel diffraction in the propagating direction and the fringe pattern of a point source, known as Gabor zone plate has spatial symmetry, so it can be used as a basis for fast calculation of diffraction field in CGH. A fast Fresnel CGH method based on the novel look-up table (N-LUT) method is proposed, the principle fringe patterns (PFPs) at the virtual plane is pre-calculated by the acceleration algorithm and be stored. Secondly, the Fresnel diffraction fringe pattern at dummy plane can be obtained. Finally, the Fresnel propagation from dummy plan to hologram plane. The simulation experiments and optical experiments based on Liquid Crystal On Silicon (LCOS) is setup to demonstrate the validity of the proposed method under the premise of ensuring the quality of 3D reconstruction the method proposed in the paper can be applied to shorten the computational time and improve computational efficiency.

Bayesian site selection for fast Gaussian process regression

KAUST Repository

Pourhabib, Arash; Liang, Faming; Ding, Yu

2014-01-01

Gaussian Process (GP) regression is a popular method in the field of machine learning and computer experiment designs; however, its ability to handle large data sets is hindered by the computational difficulty in inverting a large covariance matrix. Likelihood approximation methods were developed as a fast GP approximation, thereby reducing the computation cost of GP regression by utilizing a much smaller set of unobserved latent variables called pseudo points. This article reports a further improvement to the likelihood approximation methods by simultaneously deciding both the number and locations of the pseudo points. The proposed approach is a Bayesian site selection method where both the number and locations of the pseudo inputs are parameters in the model, and the Bayesian model is solved using a reversible jump Markov chain Monte Carlo technique. Through a number of simulated and real data sets, it is demonstrated that with appropriate priors chosen, the Bayesian site selection method can produce a good balance between computation time and prediction accuracy: it is fast enough to handle large data sets that a full GP is unable to handle, and it improves, quite often remarkably, the prediction accuracy, compared with the existing likelihood approximations. © 2014 Taylor and Francis Group, LLC.

Bayesian site selection for fast Gaussian process regression

KAUST Repository

Pourhabib, Arash

2014-02-05

Gaussian Process (GP) regression is a popular method in the field of machine learning and computer experiment designs; however, its ability to handle large data sets is hindered by the computational difficulty in inverting a large covariance matrix. Likelihood approximation methods were developed as a fast GP approximation, thereby reducing the computation cost of GP regression by utilizing a much smaller set of unobserved latent variables called pseudo points. This article reports a further improvement to the likelihood approximation methods by simultaneously deciding both the number and locations of the pseudo points. The proposed approach is a Bayesian site selection method where both the number and locations of the pseudo inputs are parameters in the model, and the Bayesian model is solved using a reversible jump Markov chain Monte Carlo technique. Through a number of simulated and real data sets, it is demonstrated that with appropriate priors chosen, the Bayesian site selection method can produce a good balance between computation time and prediction accuracy: it is fast enough to handle large data sets that a full GP is unable to handle, and it improves, quite often remarkably, the prediction accuracy, compared with the existing likelihood approximations. © 2014 Taylor and Francis Group, LLC.

Oral calcium carbonate affects calcium but not phosphorus balance in stage 3–4 chronic kidney disease

Science.gov (United States)

Hill, Kathleen M.; Martin, Berdine R.; Wastney, Meryl; McCabe, George P.; Moe, Sharon M.; Weaver, Connie M.; Peacock, Munro

2014-01-01

Chronic kidney disease (CKD) patients are given calcium carbonate to bind dietary phosphorus and reduce phosphorus retention, and to prevent negative calcium balance. Data are limited on calcium and phosphorus balance in CKD to support this. The aim of this study was to determine calcium and phosphorus balance and calcium kinetics with and without calcium carbonate in CKD patients. Eight stage 3/4 CKD patients, eGFR 36 mL/min, participated in two 3-week balances in a randomized placebo-controlled cross-over study of calcium carbonate (1500 mg/d calcium). Calcium and phosphorus balance were determined on a controlled diet. Oral and intravenous 45calcium with blood sampling and urine and fecal collections were used for calcium kinetics. Fasting blood and urine were collected at baseline and end of each week of each balance period for biochemical analyses. Results showed that patients were in neutral calcium and phosphorus balance while on placebo. Calcium carbonate produced positive calcium balance, did not affect phosphorus balance, and produced only a modest reduction in urine phosphorus excretion compared with placebo. Calcium kinetics demonstrated positive net bone balance but less than overall calcium balance suggesting tissue deposition. Fasting biochemistries of calcium and phosphate homeostasis were unaffected by calcium carbonate. If they can be extrapolated to effects of chronic therapy, these data caution against the use of calcium carbonate as a phosphate binder. PMID:23254903

Dynamic analysis of fast-acting solenoid valves using finite element method

International Nuclear Information System (INIS)

Kwon, Ki Tae; Han, Hwa Taik

2001-01-01

It is intended to develop an algorithm for dynamic simulation of fast-acting solenoid valves. The coupled equations of the electric, magnetic, and mechanical systems should be solved simultaneously in a transient nonlinear manner. The transient nonlinear electromagnetic field is analyzed by the Finite Element Method (FEM), which is coupled with nonlinear electronic circuitry. The dynamic movement of the solenoid valve is analyzed at every time step from the force balances acting on the plunger, which include the electromagnetic force calculated from the finite element analysis as well as the elastic force by a spring and the hydrodynamic pressure force along the flow passage. Dynamic responses of the solenoid valves predicted by this algorithm agree well the experimental results including bouncing effects

3-D Force-balanced Magnetospheric Configurations

International Nuclear Information System (INIS)

Sorin Zaharia; Cheng, C.Z.; Maezawa, K.

2003-01-01

The knowledge of plasma pressure is essential for many physics applications in the magnetosphere, such as computing magnetospheric currents and deriving magnetosphere-ionosphere coupling. A thorough knowledge of the 3-D pressure distribution has however eluded the community, as most in-situ pressure observations are either in the ionosphere or the equatorial region of the magnetosphere. With the assumption of pressure isotropy there have been attempts to obtain the pressure at different locations by either (a) mapping observed data (e.g., in the ionosphere) along the field lines of an empirical magnetospheric field model or (b) computing a pressure profile in the equatorial plane (in 2-D) or along the Sun-Earth axis (in 1-D) that is in force balance with the magnetic stresses of an empirical model. However, the pressure distributions obtained through these methods are not in force balance with the empirical magnetic field at all locations. In order to find a global 3-D plasma pressure distribution in force balance with the magnetospheric magnetic field, we have developed the MAG-3D code, that solves the 3-D force balance equation J x B = (upside-down delta) P computationally. Our calculation is performed in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials as B = (upside-down delta) psi x (upside-down delta) alpha. The pressure distribution, P = P(psi,alpha), is prescribed in the equatorial plane and is based on satellite measurements. In addition, computational boundary conditions for y surfaces are imposed using empirical field models. Our results provide 3-D distributions of magnetic field and plasma pressure as well as parallel and transverse currents for both quiet-time and disturbed magnetospheric conditions

Computer-Simulation of Balance Handling

NARCIS (Netherlands)

Massen, C.H.; Swüste, C.H.W.; Robens, E.; Poulis, J.A.

1999-01-01

Several decades ago, when working in the field of magnetism, we had to use a balance the sensitivity of which was limited only by Brownian motion. This balance was a very slow one and to calculate the moment of force measured by it we used its equation of motion, T=Ja+ka+Ca, where we measured the

Comparison of 30-2 Standard and Fast programs of Swedish Interactive Threshold Algorithm of Humphrey Field Analyzer for perimetry in patients with intracranial tumors.

Science.gov (United States)

Singh, Manav Deep; Jain, Kanika

2017-11-01

To find out whether 30-2 Swedish Interactive Threshold Algorithm (SITA) Fast is comparable to 30-2 SITA Standard as a tool for perimetry among the patients with intracranial tumors. This was a prospective cross-sectional study involving 80 patients aged ≥18 years with imaging proven intracranial tumors and visual acuity better than 20/60. The patients underwent multiple visual field examinations using the two algorithms till consistent and repeatable results were obtained. A total of 140 eyes of 80 patients were analyzed. Almost 60% of patients undergoing perimetry with SITA Standard required two or more sessions to obtain consistent results, whereas the same could be obtained in 81.42% with SITA Fast in the first session itself. Of 140 eyes, 70 eyes had recordable field defects and the rest had no defects as detected by either of the two algorithms. Mean deviation (MD) (P = 0.56), pattern standard deviation (PSD) (P = 0.22), visual field index (P = 0.83) and number of depressed points at P 0.5% on MD and PSD probability plots showed no statistically significant difference between two algorithms. Bland-Altman test showed that considerable variability existed between two algorithms. Perimetry performed by SITA Standard and SITA Fast algorithm of Humphrey Field Analyzer gives comparable results among the patients of intracranial tumors. Being more time efficient and with a shorter learning curve, SITA Fast my be recommended as a standard test for the purpose of perimetry among these patients.

Fast-wave power flow along SOL field lines in NSTX and the associated power deposition profile across the SOL in front of the antenna

International Nuclear Information System (INIS)

Perkins, R.J.; Bell, R.E.; Diallo, A.; Gerhardt, S.; Hosea, J.C.; Jaworski, M.A.; LeBlanc, B.P.; Kramer, G.J.; Maingi, R.; Phillips, C.K.; Podestà, M.; Roquemore, L.; Scotti, F.; Ahn, J.-W.; Gray, T.K.; Green, D.L.; McLean, A.; Ryan, P.M.; Jaeger, E.F.; Sabbagh, S.

2013-01-01

Fast-wave heating and current drive efficiencies can be reduced by a number of processes in the vicinity of the antenna and in the scrape-off layer (SOL). On NSTX from around 25% to more than 60% of the high-harmonic fast-wave power can be lost to the SOL regions, and a large part of this lost power flows along SOL magnetic field lines and is deposited in bright spirals on the divertor floor and ceiling. We show that field-line mapping matches the location of heat deposition on the lower divertor, albeit with a portion of the heat outside of the predictions. The field-line mapping can then be used to partially reconstruct the profile of lost fast-wave power at the midplane in front of the antenna, and the losses peak close to the last closed flux surface as well as the antenna. This profile suggests a radial standing-wave pattern formed by fast-wave propagation in the SOL, and this hypothesis will be tested on NSTX-U. RF codes must reproduce these results so that such codes can be used to understand this edge loss and to minimize RF heat deposition and erosion in the divertor region on ITER. (paper)

TPSS plasma engineering studies: profile effects and plasma power balance

International Nuclear Information System (INIS)

Borowski, S.K.; Strickler, D.J.

1985-01-01

A computationally fast profile-averaged, steady-state plasma model has been developed to allow studies of radial effects in ignited and driven tokamak systems. This code was used to search for the smallest size tokamak consistent with power balance calculations

Balance Treatment Ameliorates Anxiety and Increases Self-Esteem in Children with Comorbid Anxiety and Balance Disorder

Science.gov (United States)

Bart, Orit; Bar-Haim, Yair; Weizman, Einat; Levin, Moran; Sadeh, Avi; Mintz, Matti

2009-01-01

Comorbidity between balance and anxiety disorders in adult population is a well-studied clinical entity. Children might be particularly prone to develop balance-anxiety comorbidity, but surprisingly they are practically neglected in this field of research. The consequence is that children are treated for what seems to be the primary disorder…

[Effects of reduced nitrogen application and soybean intercropping on nitrogen balance of sugarcane field].

Science.gov (United States)

Liu, Yu; Zhang, Ying; Yang, Wen-ting; Li, Zhi-xian; Guan, Ao-mei

2015-03-01

A four-year (2010-2013) field experiment was carried out to explore the effects of three planting patterns (sugarcane, soybean monoculture and sugarcane-soybean 1:2 intercropping) with two nitrogen input levels (300 and 525 kg . hm-2) on soybean nitrogen fixation, sugarcane and soybean nitrogen accumulation, and ammonia volatilization and nitrogen leaching in sugarcane field. The results showed that the soybean nitrogen fixation efficiency (NFE) of sugarcane-soybean inter-cropping was lower than that of soybean monoculture. There was no significant difference in NFE among the treatments with the two nitrogen application rates. The nitrogen application rate and inter-cropping did not remarkably affect nitrogen accumulation of sugarcane and soybean. The ammonia volatilization of the reduced nitrogen input treatment was significantly lower than that of the conventional nitrogen input treatment. Furthermore, there was no significant difference in nitrogen leaching at different nitrogen input levels and among different planting patterns. The sugarcane field nitrogen balance analysis indicated that the nitrogen application rate dominated the nitrogen budget of sugarcane field. During the four-year experiment, all treatments leaved a nitrogen surplus (from 73.10 to 400.03 kg . hm-2) , except a nitrogen deficit of 66.22 kg . hm-2 in 2011 in the treatment of sugarcane monoculture with the reduced nitrogen application. The excessive nitrogen surplus might increase the risk of nitrogen pollution in the field. In conclusion, sugarcane-soybean intercropping with reduced nitrogen application is feasible to practice in consideration of enriching the soil fertility, reducing nitrogen pollution and saving production cost in sugarcane field.

Heavy-metal balances of agro-ecosystems in the Netherlands.

NARCIS (Netherlands)

Moolenaar, S.W.; Lexmond, Th.M.

1998-01-01

Heavy-metal flows (Cd, Cu, Pb, and Zn) of arable, dairy and mixed farming systems in the Netherlands were studied, and farm-gate and field-scale balances calculated. On the field-scale, static and dynamic balances were distinguished. By determining the characteristic metal flows, it became possible

Converting Paddy Rice Field to Urban Use Dramatically Altered the Water and Energy Balances in Southern China

Science.gov (United States)

Hao, L.; Sun, G.; Liu, Y.; Qin, M.; Huang, X.; Fang, D.

2017-12-01

Paddy rice wetlands are the main land use type across southern China, which impact the regional environments by affecting evapotranspiration (ET) and other water and energy related processes. Our study focuses on the effects of land-cover change on water and energy processes in the Qinhuai River Basin, a typical subtropical humid region that is under rapid ecological and economical transformations. This study integrates multiple methods and techniques including remote sensing, water and energy balance model (i.e., Surface Energy Balance Algorithm for Land, SEBAL), ecohydrological model (i.e., Soil and Water Assessment Tool, SWAT), and ground observation (Eddy Covariance measurement, etc.). We found that conversion of paddy rice field to urban use led to rise in vapor pressure deficit (VPD) and reduction in ET, and thus resulted in changes in local and regional water and heat balance. The effects of the land-use change on ET and VPD overwhelmed the effects of regional climate warming and climate variability. We conclude that the ongoing large-scale urbanization of the rice paddy-dominated regions in humid southern China and East Asia will likely exacerbate environmental consequences (e.g., elevated storm-flow volume, aggravated flood risks, and intensified urban heat island and urban dry island effects). The potential role of vegetated land cover in moderating water and energy balances and maintaining a stable climate should be considered in massive urban planning and global change impact assessment in southern China.

Simulating polar bear energetics during a seasonal fast using a mechanistic model.

Directory of Open Access Journals (Sweden)

Paul D Mathewson

Full Text Available In this study we tested the ability of a mechanistic model (Niche Mapper™ to accurately model adult, non-denning polar bear (Ursus maritimus energetics while fasting during the ice-free season in the western Hudson Bay. The model uses a steady state heat balance approach, which calculates the metabolic rate that will allow an animal to maintain its core temperature in its particular microclimate conditions. Predicted weight loss for a 120 day fast typical of the 1990s was comparable to empirical studies of the population, and the model was able to reach a heat balance at the target metabolic rate for the entire fast, supporting use of the model to explore the impacts of climate change on polar bears. Niche Mapper predicted that all but the poorest condition bears would survive a 120 day fast under current climate conditions. When the fast extended to 180 days, Niche Mapper predicted mortality of up to 18% for males. Our results illustrate how environmental conditions, variation in animal properties, and thermoregulation processes may impact survival during extended fasts because polar bears were predicted to require additional energetic expenditure for thermoregulation during a 180 day fast. A uniform 3°C temperature increase reduced male mortality during a 180 day fast from 18% to 15%. Niche Mapper explicitly links an animal's energetics to environmental conditions and thus can be a valuable tool to help inform predictions of climate-related population changes. Since Niche Mapper is a generic model, it can make energetic predictions for other species threatened by climate change.

Simulating polar bear energetics during a seasonal fast using a mechanistic model.

Science.gov (United States)

Mathewson, Paul D; Porter, Warren P

2013-01-01

In this study we tested the ability of a mechanistic model (Niche Mapper™) to accurately model adult, non-denning polar bear (Ursus maritimus) energetics while fasting during the ice-free season in the western Hudson Bay. The model uses a steady state heat balance approach, which calculates the metabolic rate that will allow an animal to maintain its core temperature in its particular microclimate conditions. Predicted weight loss for a 120 day fast typical of the 1990s was comparable to empirical studies of the population, and the model was able to reach a heat balance at the target metabolic rate for the entire fast, supporting use of the model to explore the impacts of climate change on polar bears. Niche Mapper predicted that all but the poorest condition bears would survive a 120 day fast under current climate conditions. When the fast extended to 180 days, Niche Mapper predicted mortality of up to 18% for males. Our results illustrate how environmental conditions, variation in animal properties, and thermoregulation processes may impact survival during extended fasts because polar bears were predicted to require additional energetic expenditure for thermoregulation during a 180 day fast. A uniform 3°C temperature increase reduced male mortality during a 180 day fast from 18% to 15%. Niche Mapper explicitly links an animal's energetics to environmental conditions and thus can be a valuable tool to help inform predictions of climate-related population changes. Since Niche Mapper is a generic model, it can make energetic predictions for other species threatened by climate change.

Fast Nonconvex Model Predictive Control for Commercial Refrigeration

DEFF Research Database (Denmark)

Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Jørgensen, John Bagterp

2012-01-01

in fewer than 5 or so iterations. We employ a fast convex quadratic programming solver to carry out the iterations, which is more than fast enough to run in real-time. We demonstrate our method on a realistic model, with a full year simulation, using real historical data. These simulations show substantial...... cost savings, and reveal how the method exhibits sophisticated response to real-time variations in electricity prices. This demand response is critical to help balance real-time uncertainties associated with large penetration of intermittent renewable energy sources in a future smart grid....

Health Benefits of Fasting and Caloric Restriction.

Science.gov (United States)

Golbidi, Saeid; Daiber, Andreas; Korac, Bato; Li, Huige; Essop, M Faadiel; Laher, Ismail

2017-10-23

Obesity and obesity-related diseases, largely resulting from urbanization and behavioral changes, are now of global importance. Energy restriction, though, is associated with health improvements and increased longevity. We review some important mechanisms related to calorie limitation aimed at controlling of metabolic diseases, particularly diabetes. Calorie restriction triggers a complex series of intricate events, including activation of cellular stress response elements, improved autophagy, modification of apoptosis, and alteration in hormonal balance. Intermittent fasting is not only more acceptable to patients, but it also prevents some of the adverse effects of chronic calorie restriction, especially malnutrition. There are many somatic and potentially psychologic benefits of fasting or intermittent calorie restriction. However, some behavioral modifications related to abstinence of binge eating following a fasting period are crucial in maintaining the desired favorable outcomes.

Neutron balance as indicator of long-term resource availability in growing nuclear energy system

Energy Technology Data Exchange (ETDEWEB)

Blandinskiy, Victor [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

2017-09-15

The article describes neutron balance in nuclear energy system as necessary but not sufficient indicator of long-term sustainability. Three models are introduced to evaluate neutron balance based on nuclide chain evolution and reaction rates comparison. The indicator introduced is used to compare several nuclear energy systems consisting of thermal, fast and molten salt reactors.

Field assessment of balance in 10 to 14 year old children, reproducibility and validity of the Nintendo Wii board.

Science.gov (United States)

Larsen, Lisbeth Runge; Jørgensen, Martin Grønbech; Junge, Tina; Juul-Kristensen, Birgit; Wedderkopp, Niels

2014-06-10

Because body proportions in childhood are different to those in adulthood, children have a relatively higher centre of mass location. This biomechanical difference and the fact that children's movements have not yet fully matured result in different sway performances in children and adults. When assessing static balance, it is essential to use objective, sensitive tools, and these types of measurement have previously been performed in laboratory settings. However, the emergence of technologies like the Nintendo Wii Board (NWB) might allow balance assessment in field settings. As the NWB has only been validated and tested for reproducibility in adults, the purpose of this study was to examine reproducibility and validity of the NWB in a field setting, in a population of children. Fifty-four 10-14 year-olds from the CHAMPS-Study DK performed four different balance tests: bilateral stance with eyes open (1), unilateral stance on dominant (2) and non-dominant leg (3) with eyes open, and bilateral stance with eyes closed (4). Three rounds of the four tests were completed with the NWB and with a force platform (AMTI). To assess reproducibility, an intra-day test-retest design was applied with a two-hour break between sessions. Bland-Altman plots supplemented by Minimum Detectable Change (MDC) and concordance correlation coefficient (CCC) demonstrated satisfactory reproducibility for the NWB and the AMTI (MDC: 26.3-28.2%, CCC: 0.76-0.86) using Centre Of Pressure path Length as measurement parameter. Bland-Altman plots demonstrated satisfactory concurrent validity between the NWB and the AMTI, supplemented by satisfactory CCC in all tests (CCC: 0.74-0.87). The ranges of the limits of agreement in the validity study were comparable to the limits of agreement of the reproducibility study. Both NWB and AMTI have satisfactory reproducibility for testing static balance in a population of children. Concurrent validity of NWB compared with AMTI was satisfactory. Furthermore, the

Macroscopic electromagnetic properties of the Irvine Field-Reversed Configuration: Equilibrium, power balance and fluctuations

Science.gov (United States)

Trask, Erik Harold

The plasma parameters and characteristics of the Irvine Field-Reversed Configuration (IFRC) are summarized in this thesis. Particular emphasis is placed on the development of the different diagnostics used to make measurements in the experiment, as well as the measurements themselves. Whenever possible, actual measurements are used in lieu of theoretical or analytical fits to data. Analysis of magnetic probes (B-dots) comprises the bulk of what is known about the IFRC. From these B-dot probes, the magnetic field structure in a two dimensional plane at constant toroidal position has been determined, and has been found to be consistent with a field-reversed configuration. Peak reversed fields of approximately 250 Gauss have been observed. Further analyses have been developed to extract information from the magnetic field structure, including components of the electric field, the current density, and plasma pressure in the same two dimensional plane. Electric field magnitudes reach 600 V/m, concurrent with current densities greater than 105 Amps/m2 and thermal pressures over 200 Pa. Spectroscopic analysis of hydrogen lines has been done to make estimates of the electron temperature, while spectroscopic measurements of the Doppler broadening of the Halpha line31 have allowed an estimate of the ion temperature. Particle losses out one axial end plane measured by an array of Faraday cups quantify the how well the configuration traps particles. Spectral information derived from B-dot probes indicates that there is substantial power present at frequencies lying between the hydrogen cyclotron and mean gyrofrequency. These various measurements are used to find the following parameters that characterize the Irvine FRC: (1) Electromagnetic and thermal stored energies as functions of time. (2) Power balance, including input power from the field coils, resistive heating, power lost by particle transport and radiation, and particle and energy confinement times. (3) Strong

Fast neutron dosimeter with wide base silicon diode

International Nuclear Information System (INIS)

Ma Lu

1986-01-01

This paper briefly introduces a wide base silicon diode fast neutron dosimeter with wide measuring range and good energy response to fast neutron. It is suitable to be used to detect fast neutrons in the mixed field of γ-ray, thermal neutrons and fast neutrons

Mode Conversion of High-Field-Side-Launched Fast Waves at the Second Harmonic of Minority Hydrogen in Advanced Tokamak Reactors

International Nuclear Information System (INIS)

Sund, R.; Scharer, J.

2003-01-01

Under advanced tokamak reactor conditions, the Ion-Bernstein wave (IBW) can be generated by mode conversion of a fast magnetosonic wave incident from the high-field side on the second harmonic resonance of a minority hydrogen component, with near 100% efficiency. IBWs have the recognized capacity to create internal transport barriers through sheared plasma flows resulting from ion absorption. The relatively high frequency (around 200 MHz) minimizes parasitic electron absorption and permits the converted IBW to approach the 5th tritium harmonic. It also facilitates compact antennas and feeds, and efficient fast wave launch. The scheme is applicable to reactors with aspect ratios < 3 such that the conversion and absorption layers are both on the high field side of the magnetic axis. Large machine size and adequate separation of the mode conversion layer from the magnetic axis minimize poloidal field effects in the conversion zone and permit a 1-D full-wave analysis. 2-D ray tracing of the IBW indicates a slightly bean-shaped equilibrium allows access to the tritium resonance

Impact of health and recreation on work-life balance: a case study of expatriates

OpenAIRE

Naithani, Pranav

2016-01-01

Factors influencing work-life balance are evolving at a very fast pace, thus creating a fecund ground for innovative work-life balance tools and techniques. The increasing significance of expatriates in the global workforce necessitates a targeted set of work-life balance initiatives to help expatriate workers contribute more effectively in the competitive work environment. Health and recreation are the two important life spheres which play a very important role in success or failure of an ex...

Influence of field emission on the propagation of cylindrical fast ionization wave in atmospheric-pressure nitrogen

Energy Technology Data Exchange (ETDEWEB)

Levko, Dmitry; Raja, Laxminarayan L. [Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712 (United States)

2016-04-21

The influence of field emission of electrons from surfaces on the fast ionization wave (FIW) propagation in high-voltage nanosecond pulse discharge in the atmospheric-pressure nitrogen is studied by a one-dimensional Particle-in-Cell Monte Carlo Collisions model. A strong influence of field emission on the FIW dynamics and plasma parameters is obtained. Namely, the accounting for the field emission makes possible the bridging of the cathode–anode gap by rather dense plasma (∼10{sup 13 }cm{sup −3}) in less than 1 ns. This is explained by the generation of runaway electrons from the field emitted electrons. These electrons are able to cross the entire gap pre-ionizing it and promoting the ionization wave propagation. We have found that the propagation of runaway electrons through the gap cannot be accompanied by the streamer propagation, because the runaway electrons align the plasma density gradients. In addition, we have obtained that the field enhancement factor allows controlling the speed of ionization wave propagation.

Logistical and economic obstacles to a fast reactor programme

International Nuclear Information System (INIS)

Sweet, C.

1982-01-01

Fast reactor studies used to place great emphasis on its role as a breeder of plutonium, thereby raising the prospect of a nuclear power system free from the constraint of uranium supplies. Today, not only the timing of fast reactor introduction has slipped (by two or three decades) but the perspective which was central to energy policy has changed dramatically. This article first examines the fast reactor as a system and looks at the interaction of four key variables in its logistics. It then looks at the rise in real costs, especially capital costs. Given the parameters that determine the plutonium balance and the economics of the fast reactor system, the author questions whether there is a sound basis for its introduction, and concludes by suggesting that the most pressing requirement is a study of the opportunity costs of fast reactor R and D expenditures. (author)

Interface conditions for fast-reaction fronts in wet porous mineral materials: the case of concrete carbonation

NARCIS (Netherlands)

Muntean, A.; Böhm, M.

2009-01-01

Reaction–diffusion processes, where slow diffusion balances fast reaction, usually exhibit internal loci where the reactions are concentrated. Some modeling and simulation aspects of using kinetic free-boundary conditions to drive fast carbonation reaction fronts into unsaturated porous cement-based

Integral test on activation cross section of tag gas nuclides using fast neutron spectrum fields

Energy Technology Data Exchange (ETDEWEB)

Aoyama, Takafumi; Suzuki, Soju [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1997-03-01

Activation cross sections of tag gas nuclides, which will be used for the failed fuel detection and location in FBR plants, were evaluated by the irradiation tests in the fast neutron spectrum fields in JOYO and YAYOI. The comparison of their measured radioactivities and the calculated values using the JENDL-3.2 cross section set showed that the C/E values ranged from 0.8 to 2.8 for the calibration tests in YAYOI and that the present accuracies of these cross sections were confirmed. (author)

Fast beam radiofrequency spectroscopy

International Nuclear Information System (INIS)

Pipkin, F.M.

1983-01-01

The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment

Energy Technology Data Exchange (ETDEWEB)

Holley, A. T.; Pattie, R. W.; Young, A. R. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Broussard, L. J. [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Davis, J. L.; Ito, T. M.; Lyles, J. T. M.; Makela, M.; Morris, C. L.; Mortensen, R.; Saunders, A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hickerson, K.; Mendenhall, M. P. [W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Liu, C.-Y. [Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States); Mammei, R. R. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States); Rios, R. [Department of Physics, Idaho State University, Pocatello, Idaho 83209 (United States)

2012-07-15

The UCNA collaboration is making a precision measurement of the {beta} asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during the 2007 run cycle of the Los Alamos Neutron Science Center's 800 MeV proton accelerator is detailed. These studies determined the flipping efficiency of the device, averaged over the UCN spectrum present at the location of the spin flipper, to be {epsilon}=0.9985(4).

Associations of knee extensor strength and standing balance with physical function in knee osteoarthritis.

Science.gov (United States)

Pua, Yong-Hao; Liang, Zhiqi; Ong, Peck-Hoon; Bryant, Adam L; Lo, Ngai-Nung; Clark, Ross A

2011-12-01

Knee extensor strength is an important correlate of physical function in patients with knee osteoarthritis; however, it remains unclear whether standing balance is also a correlate. The purpose of this study was to evaluate the cross-sectional associations of knee extensor strength, standing balance, and their interaction with physical function. One hundred four older adults with end-stage knee osteoarthritis awaiting a total knee replacement (mean ± SD age 67 ± 8 years) participated. Isometric knee extensor strength was measured using an isokinetic dynamometer. Standing balance performance was measured by the center of pressure displacement during quiet standing on a balance board. Physical function was measured by the self-report Short Form 36 (SF-36) questionnaire and by the 10-meter fast-pace gait speed test. After adjustment for demographic and knee pain variables, we detected significant knee strength by standing balance interaction terms for both SF-36 physical function and fast-pace gait speed. Interrogation of the interaction revealed that standing balance in the anteroposterior plane was positively related to physical function among patients with lower knee extensor strength. Conversely, among patients with higher knee extensor strength, the standing balance-physical function associations were, or tended to be, negative. These findings suggest that although standing balance was related to physical function in patients with knee osteoarthritis, this relationship was complex and dependent on knee extensor strength level. These results are of importance in developing intervention strategies and refining theoretical models, but they call for further study. Copyright © 2011 by the American College of Rheumatology.

Sufentanil Vs Fentanyl for Fast-Track Cardiac Anaesthesia

Directory of Open Access Journals (Sweden)

C M Deshpande

2009-01-01

Full Text Available A perioperative anaesthetic management that aims to facilitate tracheal extubation of patients within 1-6 hrs after cardiac surgery is called "fast-track′. Main advantage of ′fast-track" method is better usage of medical resources and lowering hospital costs without increasing morbidity and mortality of the patients. Standard fast-track protocols contain short acting anaesthetic agents, smaller incisions and decreased pump times without hypothermia. In this study we compared two short acting opioid drugs, fentanyl versus Sufentanil when used as a part of the balanced anaesthesia technique for fast track in cardiac surgery patients& evaluated the time taken for extubation, haemodynamic stability, analgesia requirements& incidence of awareness. The results from the study show thatboth agents provide good haemodynamic stability and postoperative analgesia. Although Sufentanil provides earlier extuba-tion, both agents reduce the ICU stay equally. In conclusion both agents can be used effectively for fasttrack cardiac anaesthesia.

Engineering the mobility increment in pentacene-based field-effect transistors by fast cooling of polymeric modification layer

Science.gov (United States)

Ling, Haifeng; Zhang, Chenxi; Chen, Yan; Shao, Yaqing; Li, Wen; Li, Huanqun; Chen, Xudong; Yi, Mingdong; Xie, Linghai; Huang, Wei

2017-06-01

In this work, we investigate the effect of the cooling rate of polymeric modification layers (PMLs) on the mobility improvement of pentacene-based organic field-effect transistors (OFETs). In contrast to slow cooling (SC), the OFETs fabricated through fast cooling (FC) with PMLs containing side chain-phenyl rings, such as polystyrene (PS) and poly (4-vinylphenol) (PVP), show an obvious mobility incensement compared with that of π-group free polymethylmethacrylate (PMMA). Atomic force microscopy (AFM) images and x-ray diffraction (XRD) characterizations have showed that fast-cooled PMLs could effectively enhance the crystallinity of pentacene, which might be related to the optimized homogeneity of surface energy on the surface of polymeric dielectrics. Our work has demonstrated that FC treatment could be a potential strategy for performance modulation of OFETs.

Steering the osteoclast through the demineralization-collagenolysis balance

DEFF Research Database (Denmark)

Søe, Kent; Merrild, Ditte Marie Horslev; Delaissé, Jean-Marie

2013-01-01

are generated when collagen degradation is slower than demineralization, and trenches when collagen degradation is as fast as demineralization. Next we treated the osteoclasts with a low dose of a carbonic anhydrase inhibitor to slightly decrease the rate of demineralization, thereby allowing collagen......, forming a pit, and continues parallel to the bone surface, forming a trench. Importantly, we show that the progress of the osteoclast along this route depends on the balance between the rate of collagenolysis and demineralization. We propose that the osteocytes and bone lining cells surrounding...... the osteoclast may act on this balance to steer the osteoclast resorptive activity in order to give the excavations a specific shape....

Adaptive Equilibrium Regulation: A Balancing Act in Two Timescales

Science.gov (United States)

Boker, Steven M.

2015-01-01

An equilibrium involves a balancing of forces. Just as one maintains upright posture in standing or walking, many self-regulatory and interpersonal behaviors can be framed as a balancing act between an ever changing environment and within-person processes. The emerging balance between person and environment, the equilibria, are dynamic and adaptive in response to development and learning. A distinction is made between equilibrium achieved solely due to a short timescale balancing of forces and a longer timescale preferred equilibrium which we define as a state towards which the system slowly adapts. Together, these are developed into a framework that this article calls Adaptive Equilibrium Regulation (ÆR), which separates a regulatory process into two timescales: a faster regulation that automatically balances forces and a slower timescale adaptation process that reconfigures the fast regulation so as to move the system towards its preferred equilibrium when an environmental force persists over the longer timescale. This way of thinking leads to novel models for the interplay between multiple timescales of behavior, learning, and development. PMID:27066197

Quantifying mass balance processes on the Southern Patagonia Icefield

DEFF Research Database (Denmark)

Schaefer, M.; Machguth, Horst; Falvey, M.

2015-01-01

We present surface mass balance simulations of the Southern Patagonia Icefield (SPI) driven by downscaled reanalysis data. The simulations were evaluated and interpreted using geodetic mass balances, measured point balances and a complete velocity field of the icefield for spring 2004. The high m...

Balance Systems and the Variational Bicomplex

Directory of Open Access Journals (Sweden)

Serge Preston

2011-07-01

Full Text Available In this work we show that the systems of balance equations (balance systems of continuum thermodynamics occupy a natural place in the variational bicomplex formalism. We apply the vertical homotopy decomposition to get a local splitting (in a convenient domain of a general balance system as the sum of a Lagrangian part and a complemental ''pure non-Lagrangian'' balance system. In the case when derivatives of the dynamical fields do not enter the constitutive relations of the balance system, the ''pure non-Lagrangian'' systems coincide with the systems introduced by S. Godunov [Soviet Math. Dokl. 2 (1961, 947-948] and, later, asserted as the canonical hyperbolic form of balance systems in [Müller I., Ruggeri T., Rational extended thermodynamics, 2nd ed., Springer Tracts in Natural Philosophy, Vol. 37, Springer-Verlag, New York, 1998].

Plasma-ring, fast-opening switch

International Nuclear Information System (INIS)

Hartman, C.W.; Eddleman, J.; Hammer, J.H.

1986-01-01

The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap

Fast particle tracking with wake fields

Energy Technology Data Exchange (ETDEWEB)

Dohlus, M.; Floettmann, K.; Henning, C.

2012-01-15

Tracking calculations of charged particles in electromagnetic fields require in principle the simultaneous solution of the equation of motion and of Maxwell's equations. In many tracking codes a simpler and more efficient approach is used: external fields like that of the accelerating structures are provided as field maps, generated in separate computations and for the calculation of self fields the model of a particle bunch in uniform motion is used. We describe how an externally computed wake function can be approximated by a table of Taylor coefficients and how the wake field kick can be calculated for the particle distribution in a tracking calculation. The integrated kick, representing the effect of a distributed structure, is applied at a discrete time. As an example, we use our approach to calculate the emittance growth of a bunch in an undulator beam pipe due to resistive wall wake field effects. (orig.)

Water conservation in fasting northern elephant seals (Mirounga angustirostris).

Science.gov (United States)

Lester, Christopher W; Costa, Daniel P

2006-11-01

Prolonged terrestrial fasting is a key element in the life history of elephant seals. While on land seals typically fast without access to fresh water, and thus must maintain positive water balance by reductions in water loss such that they can subsist primarily on metabolic water production (MWP). The terrestrial apnea demonstrated by seals may reduce respiratory evaporative water loss (REWL) to levels that allow seals to make a net gain of water from MWP. We empirically measured REWL in 13 fasting northern elephant seal pups and determined the effects on water conservation of a breathing mode that incorporates a regular pattern of apneas, of > or =1 min in duration, followed by eupneic recovery, compared with a breathing mode with no apneas longer than 20 s and resembling typical breathing patterns in other mammals (normative breathing). Overall REWL fell 41% from 0.075+/-0.013 g min(-1) (mean +/- s.d.) during normative breathing to 0.044+/-0.006 g min(-1) during apneic breathing. The decline in REWL is attributed to a decrease in overall ventilation rate, made possible by a decline in metabolic rate along with an increase in oxygen extraction that would occur during apneic breathing. Data on the range of ambient humidity conditions at the local breeding site were collected and used to bound the range of environmental conditions used in laboratory measurements. Our data showed that the observed variations in ambient humidity had no significant effect on REWL. A combination of apneic breathing and the complex nasal turbinates allows fasting elephant seals to reduce REWL well below the rate of MWP so that they can maintain water balance during the fast.

Loss of Balance between Striatal Feedforward Inhibition and Corticostriatal Excitation Leads to Tremor.

Science.gov (United States)

Oran, Yael; Bar-Gad, Izhar

2018-02-14

Fast-spiking interneurons (FSIs) exert powerful inhibitory control over the striatum and are hypothesized to balance the massive excitatory cortical and thalamic input to this structure. We recorded neuronal activity in the dorsolateral striatum and globus pallidus (GP) concurrently with the detailed movement kinematics of freely behaving female rats before and after selective inhibition of FSI activity using IEM-1460 microinjections. The inhibition led to the appearance of episodic rest tremor in the body part that depended on the somatotopic location of the injection within the striatum. The tremor was accompanied by coherent oscillations in the local field potential (LFP). Individual neuron activity patterns became oscillatory and coherent in the tremor frequency. Striatal neurons, but not GP neurons, displayed additional temporal, nonoscillatory correlations. The subsequent reduction in the corticostriatal input following muscimol injection to the corresponding somatotopic location in the primary motor cortex led to disruption of the tremor and a reduction of the LFP oscillations and individual neuron's phase-locked activity. The breakdown of the normal balance of excitation and inhibition in the striatum has been shown previously to be related to different motor abnormalities. Our results further indicate that the balance between excitatory corticostriatal input and feedforward FSI inhibition is sufficient to break down the striatal decorrelation process and generate oscillations resulting in rest tremor typical of multiple basal ganglia disorders. SIGNIFICANCE STATEMENT Fast-spiking interneurons (FSIs) play a key role in normal striatal processing by exerting powerful inhibitory control over the network. FSI malfunctions have been associated with abnormal processing of information within the striatum that leads to multiple movement disorders. Here, we study the changes in neuronal activity and movement kinematics following selective inhibition of these

Effects of exposure to electromagnetic field radiation (EMFR generated by activated mobile phones on fasting blood glucose

Directory of Open Access Journals (Sweden)

Sultan Ayoub Meo

2013-04-01

Full Text Available Objective: Extensive use of mobile phones has been accompanied by a common public debate about possible adverse effects on human health. No study has been published so far to establish any association between the fastest growing innovation of mobile phone and fasting blood glucose. The aim was to determine the effects of exposure to electromagnetic field radiation generated by mobile phones on fasting blood glucose in Wistar Albino rats. Materials and Methods: 40 Male Albino rats (Wistar Strain were divided into 5 equally numerous groups. Group A served as the control one, group B received mobile phone radiation for less than 15 min/day, group C: 15-30 min/day, group D: 31-45 min/day, and group E: 46-60 min/day for a total period of 3 months. Fasting blood glucose was determined by using Spectrophotometer and serum insulin by Enzyme-linked Immunosorbent Assay (ELISA. The Homeostatic Model (HOMA-B was applied for the assessment of β-cell function and (HOMA-IR for resistance to insulin. Results: Wister Albino rats exposed to mobile phone radiation for longer than 15 min a day for a total period of 3 months had significantly higher fasting blood glucose (p < 0.015 and serum insulin (p < 0.01 compared to the control group. HOMA-IR for insulin resistance was significantly increased (p < 0.003 in the groups that were exposed for 15-30 and 46-60 min/day compared to the control rats. Conclusion: The results of the present study show an association between long-term exposure to activated mobile phones and increase in fasting blood glucose and serum insulin in Albino rats.

SPECTRUM WEIGHTED RESPONSES OF SEVERAL DETECTORS IN MIXED FIELDS OF FAST AND THERMAL NEUTRONS

Directory of Open Access Journals (Sweden)

SANG IN KIM

2014-04-01

Full Text Available The spectrum weighted responses of various detectors were calculated to provide guidance on the proper selection and use of survey instruments on the basis of their energy response characteristics on the neutron fields. To yield the spectrum weighted response, the detector response functions of 17 neutron-measuring devices were numerically folded with each of the produced calibration neutron spectra through the in-house developed software ‘K-SWR’. The detectors’ response functions were taken from the IAEA Technical Reports Series No. 403 (TRS-403. The reference neutron fields of 21 kinds with 2 spectra groups with different proportions of thermal and fast neutrons have been produced using neutrons from the 241Am-Be sources held in a graphite pile, a bare 241Am-Be source, and a DT neutron generator. Fluence-average energy (Eave varied from 3.8 MeV to 16.9 MeV, and the ambient-dose-equivalent rate [H*(10/h] varied from 0.99 to 16.5 mSv/h.

Field assessment of balance in 10 to 14 year old children, reproducibility and validity of the Nintendo Wii board

Science.gov (United States)

2014-01-01

Background Because body proportions in childhood are different to those in adulthood, children have a relatively higher centre of mass location. This biomechanical difference and the fact that children’s movements have not yet fully matured result in different sway performances in children and adults. When assessing static balance, it is essential to use objective, sensitive tools, and these types of measurement have previously been performed in laboratory settings. However, the emergence of technologies like the Nintendo Wii Board (NWB) might allow balance assessment in field settings. As the NWB has only been validated and tested for reproducibility in adults, the purpose of this study was to examine reproducibility and validity of the NWB in a field setting, in a population of children. Methods Fifty-four 10–14 year-olds from the CHAMPS-Study DK performed four different balance tests: bilateral stance with eyes open (1), unilateral stance on dominant (2) and non-dominant leg (3) with eyes open, and bilateral stance with eyes closed (4). Three rounds of the four tests were completed with the NWB and with a force platform (AMTI). To assess reproducibility, an intra-day test-retest design was applied with a two-hour break between sessions. Results Bland-Altman plots supplemented by Minimum Detectable Change (MDC) and concordance correlation coefficient (CCC) demonstrated satisfactory reproducibility for the NWB and the AMTI (MDC: 26.3-28.2%, CCC: 0.76-0.86) using Centre Of Pressure path Length as measurement parameter. Bland-Altman plots demonstrated satisfactory concurrent validity between the NWB and the AMTI, supplemented by satisfactory CCC in all tests (CCC: 0.74-0.87). The ranges of the limits of agreement in the validity study were comparable to the limits of agreement of the reproducibility study. Conclusion Both NWB and AMTI have satisfactory reproducibility for testing static balance in a population of children. Concurrent validity of NWB compared

Radiation balances and the solar constant

Science.gov (United States)

Crommelynck, D.

1981-01-01

The radiometric concepts are defined in order to consider various types of radiation balances and relate them to the diabetic form of the energy balance. Variability in space and time of the components of the radiation field are presented. A specific concept for sweeping which is tailored to the requirements is proposed. Finally, after establishing the truncated character of the present knowledge of the radiation balance. The results of the last observations of the solar constant are given. Ground and satellite measurement techniques are discussed.

Fast, large field-of-view, telecentric optical-CT scanning system for 3D radiochromic dosimetry

Energy Technology Data Exchange (ETDEWEB)

Thomas, A; Oldham, M, E-mail: ast5@duke.ed [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

2010-11-01

We describe initial experiences with an in-house, fast, large field-of-view optical-CT telecentric scanner (the Duke Large field of view Optical-CT Scanner (DLOS)). The DLOS system is designed to enable telecentric optical-CT imaging of dosimeters up to 24 cm in diameter with a spatial resolution of 1 mm{sup 3}, in approximately 10 minutes. These capabilities render the DLOS system a unique device at present. The system is a scaled up version of early prototypes in our lab. This scaling introduces several challenges, including the accurate measurement of a greatly increased range of light attenuation within the dosimeter, and the need to reduce even minor reflections and scattered light within the imaging chain. We present several corrections and techniques that enable accurate, low noise, 3D dosimetery with the DLOS system.

Method and apparatus for balancing the magnetic field detecting loops of a cryogenic gradiometer using trimming coils and superconducting disks

International Nuclear Information System (INIS)

Lutes, C.L.

1982-01-01

An apparatus for and a method of measuring the difference in intensity between two coplanar magnetic field vector components at two different points in space. The device is comprised of two interconnected, relatively large, loop patterns of opposite, flux cancelling, winding sense. One or both loops include a trimming element that is itself formed of two interconnected, relatively small, loop patterns of opposite, flux cancelling, winding sense. The device is analyzed for imbalance between the two large loops and is then balanced by placing a balancing superconducting disk of the proper characteristic in or near one of the two small loops of the trimming element. The so-trimmed apparatus forms a gradiometer of substantially improved mensuration

Interactions of fast molecular ions traversing thin foils. The contribution from field ionized Rydberg atoms in measurements on convoy electrons

International Nuclear Information System (INIS)

Gemmell, D.S.

1983-01-01

Experiments with fast (MeV) molecular-ion beams offer many attractive possibilities for studying atomic collisions in solids. Of particular value in such experiments is the possibility of determining the force fields (primarily in the induced electric field) that surround ionic fragments traversing a solid. One has the opportunity to evaluate these fields not just at the fragments themselves (as one would, for example, in stopping-power measurements with monatomic projectiles) but in the spatial regions extending out to several Angstroms from the fragment positions. In this paper we give a brief introduction to the subject and present some recent results

High-resolution nuclear magnetic resonance measurements in inhomogeneous magnetic fields: A fast two-dimensional J-resolved experiment

Energy Technology Data Exchange (ETDEWEB)

Huang, Yuqing; Cai, Shuhui; Yang, Yu; Sun, Huijun; Lin, Yanqin, E-mail: linyq@xmu.edu.cn, E-mail: chenz@xmu.edu.cn; Chen, Zhong, E-mail: linyq@xmu.edu.cn, E-mail: chenz@xmu.edu.cn [Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005 (China); Lin, Yung-Ya [Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095 (United States)

2016-03-14

High spectral resolution in nuclear magnetic resonance (NMR) is a prerequisite for achieving accurate information relevant to molecular structures and composition assignments. The continuous development of superconducting magnets guarantees strong and homogeneous static magnetic fields for satisfactory spectral resolution. However, there exist circumstances, such as measurements on biological tissues and heterogeneous chemical samples, where the field homogeneity is degraded and spectral line broadening seems inevitable. Here we propose an NMR method, named intermolecular zero-quantum coherence J-resolved spectroscopy (iZQC-JRES), to face the challenge of field inhomogeneity and obtain desired high-resolution two-dimensional J-resolved spectra with fast acquisition. Theoretical analyses for this method are given according to the intermolecular multiple-quantum coherence treatment. Experiments on (a) a simple chemical solution and (b) an aqueous solution of mixed metabolites under externally deshimmed fields, and on (c) a table grape sample with intrinsic field inhomogeneity from magnetic susceptibility variations demonstrate the feasibility and applicability of the iZQC-JRES method. The application of this method to inhomogeneous chemical and biological samples, maybe in vivo samples, appears promising.

Force Balance at the Magnetopause Determined with MMS: Application to Flux Transfer Events

Science.gov (United States)

Zhao, C.; Russell, C. T.; Strangeway, R. J.; Petrinec, S. M.; Paterson, W. R.; Zhou, M.; Anderson, B. J.; Baumjohann, W.; Bromund, K. R.; Chutter, M.;

Mass-balance measurements in Alaska and suggestions for simplified observation programs

Science.gov (United States)

Trabant, D.C.; March, R.S.

1999-01-01

US Geological Survey glacier fieldwork in Alaska includes repetitious measurements, corrections for leaning or bending stakes, an ability to reliably measure seasonal snow as deep as 10 m, absolute identification of summer surfaces in the accumulation area, and annual evaluation of internal accumulation, internal ablation, and glacier-thickness changes. Prescribed field measurement and note-taking techniques help eliminate field errors and expedite the interpretative process. In the office, field notes are transferred to computerized spread-sheets for analysis, release on the World Wide Web, and archival storage. The spreadsheets have error traps to help eliminate note-taking and transcription errors. Rigorous error analysis ends when mass-balance measurements are extrapolated and integrated with area to determine glacier and basin mass balances. Unassessable errors in the glacier and basin mass-balance data reduce the value of the data set for correlations with climate change indices. The minimum glacier mass-balance program has at least three measurement sites on a glacier and the measurements must include the seasonal components of mass balance as well as the annual balance.

Neutron transport. Physics and calculation of nuclear reactors with applications to pressurized water reactors and fast neutron reactors. 2 ed.

International Nuclear Information System (INIS)

Bussac, J.; Reuss, P.

1985-01-01

This book presents the main physical bases of neutron theory and nuclear reactor calculation. 1) Interactions of neutrons with matter and basic principles of neutron transport; 2) Neutron transport in homogeneous medium and the neutron field: kinetic behaviour, slowing-down, resonance absorption, diffusion equation, processing methods; 3) Theory of a reactor constituted with homogeneous zones: critical condition, kinetics, separation of variables, calculation and neutron balance of the fundamental mode, one-group and multigroup theories; 4) Study of heterogeneous cell lattices: fast fission factor, resonance absorption, thermal output factor, diffusion coefficient, computer codes; 5) Operation and control of reactors: perturbation theory, reactivity, fuel properties evolution, poisoning by fission products, calculation of a reactor and fuel management; 6) Study of some types of reactors: PWR and fast breeder reactors, the main reactor types of the present French program [fr

Remote field eddy current testing for steam generator inspection of fast reactor

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Noriyasu, E-mail: noriyasu.kobayashi@toshiba.co.jp [Power and Industrial Systems Research and Development Center, Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Ueno, Souichi; Nagai, Satoshi; Ochiai, Makoto [Power and Industrial Systems Research and Development Center, Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Jimbo, Noboru [Isogo Nuclear Engineering Center, Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan)

2011-12-15

Highlights: Black-Right-Pointing-Pointer We confirmed defect detection performances of remote field eddy current testing. Black-Right-Pointing-Pointer It is difficult to inspect outer surface of double wall tube steam generator. Black-Right-Pointing-Pointer We used coils with flux guide made of iron-nickel alloy for high sensitivity. Black-Right-Pointing-Pointer Output voltage of detector coil increased more than 100 times. Black-Right-Pointing-Pointer We were able to detect small hole defect of 1mm in diameter on outer surface. - Abstract: We confirmed the defect detection performances of the remote field eddy current testing (RFECT) in order to inspect the helical-coil-type double wall tube steam generator (DWTSG) with the wire mesh layer for the new small fast reactor 4S (Super-Safe, Small and Simple). As the high sensitivity techniques, we tried to increase the direct magnetic field intensity in the vicinity of the inner wall of the tube and decrease the direct magnetic field around the central axis of the tube using the exciter coil with the flux guide made of the iron-nickel alloy. We adopted the horizontal type multiple detector coils with the flux guides arrayed circumferentially to enhance the sensitivity of the radial component. According to the experimental results, the output voltage of the detector coil in the region of indirect magnetic field increased more than 100 times by the application of the exciter and detector coils with the flux guides. Finally, we were able to detect the small hole defect of 1 mm in diameter and 20% of the outer tube thickness in depth over the wire mesh layer by the adoption of the exciter coil and horizontal type multiple detector coils with the flux guides. We also confirmed that the RFECT probe is useful for detecting thinning defects. These experimental results indicated that there is the possibility that we can inspect the double wall tube with the wire mesh layer using the RFECT.

Fasting and Urinary Stones

Directory of Open Access Journals (Sweden)

Ali Shamsa

2013-11-01

Full Text Available Introduction: Fasting is considered as one of the most important practices of Islam, and according to Prophet Mohammad, fasting is obligatory upon Muslims. The aim of this study is to evaluate the effects of fasting on urinary stones. Materials and Methods: Very few studies have been carried out on urinary stones and the effect of Ramadan fasting. The sources of the present study are Medline and articles presented by local and Muslim researchers. Meanwhile, since we are acquainted with three well-known researchers in the field of urology, we contacted them via email and asked for their professional opinions. Results: The results of studies about the relationship of urinary stones and their incidence in Ramadan are not alike, and are even sometimes contradictory. Some believe that increased incidence of urinary stones in Ramadan is related not to fasting, but to the rise of weather temperature in hot months, and an increase in humidity. Conclusion: Numerous biological and behavioral changes occur in people who fast in Ramadan and some researchers believe that urinary stone increases during this month.

A fast response miniature probe for wet steam flow field measurements

International Nuclear Information System (INIS)

Bosdas, Ilias; Mansour, Michel; Abhari, Reza S; Kalfas, Anestis I

2016-01-01

Modern steam turbines require operational flexibility due to renewable energies’ increasing share of the electrical grid. Additionally, the continuous increase in energy demand necessitates efficient design of the steam turbines as well as power output augmentation. The long turbine rotor blades at the machines’ last stages are prone to mechanical vibrations and as a consequence time-resolved experimental data under wet steam conditions are essential for the development of large-scale low-pressure steam turbines. This paper presents a novel fast response miniature heated probe for unsteady wet steam flow field measurements. The probe has a tip diameter of 2.5 mm, and a miniature heater cartridge ensures uncontaminated pressure taps from condensed water. The probe is capable of providing the unsteady flow angles, total and static pressure as well as the flow Mach number. The operating principle and calibration procedure are described in the current work and a detailed uncertainty analysis demonstrates the capability of the new probe to perform accurate flow field measurements under wet steam conditions. In order to exclude any data possibly corrupted by droplets’ impact or evaporation from the heating process, a filtering algorithm was developed and implemented in the post-processing phase of the measured data. In the last part of this paper the probe is used in an experimental steam turbine test facility and measurements are conducted at the inlet and exit of the last stage with an average wetness mass fraction of 8.0%. (paper)

Wave properties near the subsolar magnetopause - Pc 3-4 energy coupling for northward interplanetary magnetic field

Science.gov (United States)

Song, P.; Russell, C. T.; Strangeway, R. J.; Wygant, J. R.; Cattell, C. A.; Fitzenreiter, R. J.; Anderson, R. R.

1993-01-01

Strong slow mode waves in the Pc 3-4 frequency range are found in the magnetosheath close to the magnetopause. We have studied these waves at one of the ISEE subsolar magnetopause crossings using the magnetic field, electric field, and plasma measurements. We use the pressure balance at the magnetopause to calibrate the Fast Plasma Experiment data versus the magnetometer data. When we perform such a calibration and renormalization, we find that the slow mode structures are not in pressure balance and small scale fluctuations in the total pressure still remain in the Pc 3-4 range. Energy in the total pressure fluctuations can be transmitted through the magnetopause by boundary motions. The Poynting flux calculated from the electric and magnetic field measurements suggests that a net Poynting flux is transmitted into the magnetopause. The two independent measurements show a similar energy transmission coefficient. The transmitted energy flux is about 18 percent of the magnetic energy flux of the waves in the magnetosheath. Part of this transmitted energy is lost in the sheath transition layer before it enters the closed field line region. The waves reaching the boundary layer decay rapidly. Little wave power is transmitted into the magnetosphere.

Conclusions drawn of tritium balance in light water reactors

International Nuclear Information System (INIS)

Dolle, L.; Bazin, J.

1978-01-01

In the tritium balance of pressurized water reactors, using boric acid and lithium in the cooling water, contribution of the tritium produced by fission, diffusing through the zircalloy of the fuel cladding estimated to 0.1%, was not in agreement with quantities measured in reactors. It is still difficult to estimate what percentage is represented by the tritium formed by fission in the fuel, owing to diffusion through cladding. The tritium balance in different working nuclear power stations is consequently of interest. The tritium balance method in the water of the cooling circuit of PWR is fast and experimentally simple. It is less sensitive to errors originating from fission yields than balance of tritium produced by fission in the fuel. A tritium balance in the water of the cooling circuit of Biblis-A, with a specific burn-up of 18000 MWd/t gives a better precision. Diffusion rate of tritium produced by fission was less than 0.2%. So low a contribution is a justification to the use of lithium with an isotopic purity of 99.9% of lithium 7 to limit at a low value the residual lithium 6 [fr

New Real-Time Market Facilitating Demand-Side Resources for System Balancing

DEFF Research Database (Denmark)

Feng, Donghan; Nyeng, Preben; Xie, Jun

2011-01-01

Many demand side resources have the potential to provide fast and low cost balancing services. Switching these devices on and off can be executed in seconds and have limited consequences for the customers if the duration is not long. With carefully designed market rules, tens of thousands...... the participation of demand-side resources. In light of the future environment of increasing intermittent renewable power and distributed energy/storage resources, stochastic time-series and Monte-Carlo simulation are used to analyze the relationship between balancing requirement and generation/demand uncertainties...

Research on the effect of the external magnetic field in the joule balance at NIM

Science.gov (United States)

Xu, Jinxin; You, Qiang; Li, Zhengkun; Bai, Yang; Lu, Yunfeng; Zhang, Zhonghua; He, Qing

2018-06-01

The first determination of the Planck constant with the second generation of the joule balance, NIM-2, was completed in 2017 with an uncertainty of 2.4  ×  10‑7. Due to the movement of the magnet during the measurement process, the effect of the external field is a critical problem in NIM-2. At present, the electromagnet system is used in NIM-2. By taking the average of the results with positive and negative exciting currents, the uncertainty from the external field is reduced to 1.7  ×  10‑7, which is still the largest source in the uncertainty budget as all the other items are less than 1  ×  10‑7. In the near future, a permanent magnet system will be applied in NIM-2 and the main field cannot be reversed. Although the coupling of the external magnetic field in the permanent magnet system is about 40 times less than that in the electromagnet system, further reduction of this effect is still required in the permanent magnet system. In this paper, the effect of the external field is analyzed in both an electromagnet system and a permanent magnet system based on simulations and experiments. Then, the methods of magnetic shielding and compensation coils are proposed and simulated in the permanent magnet system. The results show that it may be possible to reduce the uncertainty of the external field to less than 2  ×  10‑8 in the permanent magnet system by employing the two methods.

Gait characteristics, balance performance and falls in ambulant adults with cerebral palsy: An observational study.

Science.gov (United States)

Morgan, P; Murphy, A; Opheim, A; McGinley, J

2016-07-01

The relationship between spatiotemporal gait parameters, balance performance and falls history was investigated in ambulant adults with cerebral palsy (CP). Participants completed a single assessment of gait using an instrumented walkway at preferred and fast speeds, balance testing (Balance Evaluation Systems Test; BESTest), and reported falls history. Seventeen ambulatory adults with CP, mean age 37 years, participated. Gait speed was typically slow at both preferred and fast speeds (mean 0.97 and 1.21m/s, respectively), with short stride length and high cadence relative to speed. There was a significant, large positive relationship between preferred gait speed and BESTest total score (ρ=0.573; pfalls taking shorter strides. Faster gait speed was associated with better performance on tests of anticipatory and postural response components of the BESTest, suggesting potential therapeutic training targets to address either gait speed or balance performance. Future exploration of the implications of slow walking speed and reduced stride length on falls and community engagement, and the potential prognostic value of stride length on identifying falls risk is recommended. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

A fasting inducible switch modulates gluconeogenesis via activator/coactivator exchange

DEFF Research Database (Denmark)

Liu, Yi; Dentin, Renaud; Chen, Danica

2008-01-01

During early fasting, increases in skeletal muscle proteolysis liberate free amino acids for hepatic gluconeogenesis in response to pancreatic glucagon. Hepatic glucose output diminishes during the late protein-sparing phase of fasting, when ketone body production by the liver supplies compensatory...... expression through the dephosphorylation and nuclear shuttling of forkhead box O1 (FOXO1). Here we show that a fasting-inducible switch, consisting of the histone acetyltransferase p300 and the nutrient-sensing deacetylase sirtuin 1 (SIRT1), maintains energy balance in mice through the sequential induction...... of CRTC2 and FOXO1. After glucagon induction, CRTC2 stimulated gluconeogenic gene expression by an association with p300, which we show here is also activated by dephosphorylation at Ser 89 during fasting. In turn, p300 increased hepatic CRTC2 activity by acetylating it at Lys 628, a site that also...

Thermal strategies of king penguins during prolonged fasting in water.

Science.gov (United States)

Lewden, Agnès; Enstipp, Manfred R; Bonnet, Batshéva; Bost, Caroline; Georges, Jean-Yves; Handrich, Yves

2017-12-15

Most animals experience periods of unfavourable conditions, challenging their daily energy balance. During breeding, king penguins fast voluntarily for up to 1.5 months in the colony, after which they replenish their energy stores at sea. However, at sea, birds might encounter periods of low foraging profitability, forcing them to draw from previously stored energy (e.g. subcutaneous fat). Accessing peripheral fat stores requires perfusion, increasing heat loss and thermoregulatory costs. Hence, how these birds balance the conflicting demands of nutritional needs and thermoregulation is unclear. We investigated the physiological responses of king penguins to fasting in cold water by: (1) monitoring tissue temperatures, as a proxy of tissue perfusion, at four distinct sites (deep and peripheral); and (2) recording their oxygen consumption rate while birds floated inside a water tank. Despite frequent oscillations, temperatures of all tissues often reached near-normothermic levels, indicating that birds maintained perfusion to peripheral tissues throughout their fasting period in water. The oxygen consumption rate of birds increased with fasting duration in water, while it was also higher when the flank tissue was warmer, indicating greater perfusion. Hence, fasting king penguins in water maintained peripheral perfusion, despite the associated greater heat loss and, therefore, thermoregulatory costs, probably to access subcutaneous fat stores. Hence, the observed normothermia in peripheral tissues of king penguins at sea, upon completion of a foraging bout, is likely explained by their nutritional needs: depositing free fatty acids (FFA) in subcutaneous tissues after profitable foraging or mobilizing FFA to fuel metabolism when foraging success was insufficient. © 2017. Published by The Company of Biologists Ltd.

The ionisation balance of C0 to C+4

International Nuclear Information System (INIS)

Nussbaumer, H.; Storey, P.J.

1975-01-01

The ionisation balance for the ions C 0 -C +4 has been calculated for 10 8 -3 ] 12 and 2 x 10 4 K 5 K. The presence of metastable terms is included in the calculation of the collisional dielectronic recombination and ionisation coefficients. The influence of the observed solar radiation field on the ionisation balance is investigated. Changes in that field do strongly influence the results. (orig.) [de

Fast T1 mapping of the brain at high field using Look-Locker and fast imaging.

Science.gov (United States)

Jiang, Ke; Zhu, Yanjie; Jia, Sen; Wu, Yin; Liu, Xin; Chung, Yiu-Cho

2017-02-01

This study aims to develop and evaluate a new method for fast high resolution T1 mapping of the brain based on the Look-Locker technique. Single-shot turboflash sequence with high temporal acceleration is used to sample the recovery of inverted magnetization. Multi-slice interleaved acquisition within one inversion slab is used to reduce the number of inversion pulses and hence SAR. Accuracy of the proposed method was studied using simulation and validated in phantoms. It was then evaluated in healthy volunteers and stroke patients. In-vivo results were compared to values obtained by inversion recovery fast spin echo (IR-FSE) and literatures. With the new method, T 1 values in phantom experiments agreed with reference values with median error map was acquired in 3.35s and the T1 maps of the whole brain were acquired in 2min with two-slice interleaving, with a spatial resolution of 1.1×1.1×4mm 3 . The T 1 values obtained were comparable to those measured with IR-FSE and those reported in literatures. These results demonstrated the feasibility of the proposed method for fast T1 mapping of the brain in both healthy volunteers and stroke patients at 3T. Copyright © 2016 Elsevier Inc. All rights reserved.

Utility of two types of MR cisternography for patency evaluation of aqueduct and third ventriculostomy site: Three dimentsional sagittal fast spin echo sequence and steady-state coherent fast gradient echo sequence

Energy Technology Data Exchange (ETDEWEB)

Park, Jung Hyun; Kim, Eun Hee; Park, Jong Bin; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheol Kyu; Bae, Yun Jung; Lee, Kyung Mi [Dept. of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2015-07-15

We aimed to evaluate the utility of two types of MR cisternography [fast spin echo sequence and steady-state coherent gradient echo (GRE) sequence] in addition to phase contrast-cine imaging (PC-cine), for assessing patency at the aqueduct and third ventriculostomy site. 43 patients (35 patients with suspected aqueductal stenosis and 8 patients with third ventriculostomy) were retrospectively analyzed. PC-cine, 3 dimensional sagittal fast spin echo sequence [driven-equilibrium imaging (DRIVE) or volumetric isotrophic T2-weighted acquisition (T2 VISTA)] and steady-state coherent fast GRE sequence (balanced turbo field echo; bTFE) imaging were performed in all patients. The patency of the aqueduct or third ventriculostomy site was scored. Some pitfalls of each sequence were also analyzed in individual cases. 93% of all cases showed consistent scores in PC-cine, DRIVE/T2 VISTA, and bTFE imaging. DRIVE/T2 VISTA imaging provided functional information of cerebrospinal fluid flow with flow-related artifacts, while bTFE imaging allowed direct visualization of the aqueduct or ventriculostomy site. However, evaluation of anatomical structures was difficult in three cases with strong flow-related artifacts on DRIVE/T2 VISTA and in 2 cases with susceptibility artifacts on bTFE. Both DRIVE/T2 VISTA and bTFE imaging have complementary roles in evaluating the patency of the aqueduct and 3rd ventriculostomy site.

Utility of two types of MR cisternography for patency evaluation of aqueduct and third ventriculostomy site: Three dimentsional sagittal fast spin echo sequence and steady-state coherent fast gradient echo sequence

International Nuclear Information System (INIS)

Park, Jung Hyun; Kim, Eun Hee; Park, Jong Bin; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheol Kyu; Bae, Yun Jung; Lee, Kyung Mi

2015-01-01

We aimed to evaluate the utility of two types of MR cisternography [fast spin echo sequence and steady-state coherent gradient echo (GRE) sequence] in addition to phase contrast-cine imaging (PC-cine), for assessing patency at the aqueduct and third ventriculostomy site. 43 patients (35 patients with suspected aqueductal stenosis and 8 patients with third ventriculostomy) were retrospectively analyzed. PC-cine, 3 dimensional sagittal fast spin echo sequence [driven-equilibrium imaging (DRIVE) or volumetric isotrophic T2-weighted acquisition (T2 VISTA)] and steady-state coherent fast GRE sequence (balanced turbo field echo; bTFE) imaging were performed in all patients. The patency of the aqueduct or third ventriculostomy site was scored. Some pitfalls of each sequence were also analyzed in individual cases. 93% of all cases showed consistent scores in PC-cine, DRIVE/T2 VISTA, and bTFE imaging. DRIVE/T2 VISTA imaging provided functional information of cerebrospinal fluid flow with flow-related artifacts, while bTFE imaging allowed direct visualization of the aqueduct or ventriculostomy site. However, evaluation of anatomical structures was difficult in three cases with strong flow-related artifacts on DRIVE/T2 VISTA and in 2 cases with susceptibility artifacts on bTFE. Both DRIVE/T2 VISTA and bTFE imaging have complementary roles in evaluating the patency of the aqueduct and 3rd ventriculostomy site

A method for the measurement of fission rates in fast neutron fields using solid state track detectors

International Nuclear Information System (INIS)

Hansen, W.; Vogel, W.

1984-04-01

Solid state track detectors (SSTDs) are increasingly used for the registration of radiation in different fields of nuclear physics. Because of their small sizes and masses and the absence of any electronics during exposure SSTDs do not cause distortions in the system to be investigated and are useful for measurements at such places being difficult of access. The elaboration of a method is described for fission rate measurements in fast neutron fields applying SSTDs and different fissionable isotopes which were electrodeposited on stainless steel backings. Experiences of the electrodeposition and results of quality checks are presented. The evaluation of the etched tracks is performed with spark counter technique. The dependence of the counting result on essential influence parameters is discussed. (author)

Balance Velocities of the Greenland Ice Sheet

Science.gov (United States)

Joughin, Ian; Fahnestock, Mark; Ekholm, Simon; Kwok, Ron

1997-01-01

We present a map of balance velocities for the Greenland ice sheet. The resolution of the underlying DEM, which was derived primarily from radar altimetry data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail the location of an ice stream in northeastern Greenland, which was only recently discovered using satellite imagery. Enhanced flow associated with all of the major outlets is clearly visible, although small errors in the source data result in less accurate estimates of the absolute flow speeds. Nevertheless, the balance map is useful for ice-sheet modelling, mass balance studies, and field planning.

Energy measurement of fast ions trapped in the toroidal field ripple of Tore Supra

International Nuclear Information System (INIS)

Basiuk, V.; Becoulet, A.; Hutter, T.; Martin, G.; Pecquet, A.L.; Saoutic, B.

1993-09-01

During additional heating in Tore Supra (ICRF or NBI) fast ion losses due to the toroidal field ripple were clearly measured by a set of graphite probes. This diagnostic collects the flow of fast ions entering a vertical port and usually shows a maximum flux for ions originating from the vicinity of surface δ * = 0. During the monster sawteeth regime, achieved with ICRF, a remarkable phenomenon was observed: the ejection of fast ions, not correlated with any measured MHD activity. The radial distribution of these ions is quite different from that usually observed exhibiting a peak located in the central section of the plasma. In order to measure the energy distribution of these ions, from 80 keV (energy of the neutral beam injected in Tore Supra) up to 1 MeV (expected during ICRF), a new diagnostic is under construction. The principle of the diagnostic is to discriminate the ions in energy using their Larmor radius (p = 1.3 cm for 100 keV → p = 3.6 cm for 700 keV, B = 4T). The detector is made of a hollow graphite cylinder with a small entrance slot, located in a vertical port on the ion drift side. An array of six metallic collectors placed inside the graphite cylinder intercepts the ions. The current on each collector was estimated at 10 → 100 nA, during ICRF heating. The energy resolution of this diagnostic is expected to be about 20 keV for the lowest energy range and 100 keV for the highest. This type of ruggedized detector might be extrapolated for the measurements of alpha particle losses in future DT experiments. It should also be suitable for the studies of stochastic ripple diffusion. (authors). 3 refs., 9 figs

Scalable fast multipole accelerated vortex methods

KAUST Repository

Hu, Qi

2014-05-01

The fast multipole method (FMM) is often used to accelerate the calculation of particle interactions in particle-based methods to simulate incompressible flows. To evaluate the most time-consuming kernels - the Biot-Savart equation and stretching term of the vorticity equation, we mathematically reformulated it so that only two Laplace scalar potentials are used instead of six. This automatically ensuring divergence-free far-field computation. Based on this formulation, we developed a new FMM-based vortex method on heterogeneous architectures, which distributed the work between multicore CPUs and GPUs to best utilize the hardware resources and achieve excellent scalability. The algorithm uses new data structures which can dynamically manage inter-node communication and load balance efficiently, with only a small parallel construction overhead. This algorithm can scale to large-sized clusters showing both strong and weak scalability. Careful error and timing trade-off analysis are also performed for the cutoff functions induced by the vortex particle method. Our implementation can perform one time step of the velocity+stretching calculation for one billion particles on 32 nodes in 55.9 seconds, which yields 49.12 Tflop/s.

Effect of the Power Balance® hologram on balance, flexibility, strength and speed-coordination among university students

Directory of Open Access Journals (Sweden)

Rafael Merino Marban, Daniel Mayorga Vega, Emilio Fernández Rodríguez, Francisco José Santana Pérez, Oscar Romero Ramos

2011-01-01

Full Text Available Based on the body’s energy field, the inventors of Power Balance® have created a hologram that theoretically runs through frequencies that are in our natural environment. Its creators say that people may experience improve balance, strength, flexibility, endurance, concentration, coordination and recovery time, among others. The purpose of this research is to evaluate the effect of Power Balance® hologram on balance, flexibility, strength and speed-coordination in university students. A sample of 105 young volunteers’ physical education students (age 20.91 ± 3.36 years, mass 69.69 ± 11.35 kg, height 171.70 ± 8.07 cm was used. A between-group experimental design with double-blind control group was used to evaluate the possible effects of the Power Balance ® on the dynamic balance, flexibility, abdominal strength, endurance and speed-coordination measured with the Dynamic Balance Test, Sit and Reach, Sit-ups in 30 seconds and Race 10 x 5 m, respectively. A t of Student for independent and dependent samples was used to assess the potential effects between-group and intra-group, respectively. Power Balance®’s hologram produces no significant effects on the balance, flexibility, strength and speed-coordination among university students

The energy balance experiment EBEX-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods

OpenAIRE

Mauder, M.; Oncley, S.P.; Vogt, R.; Weidinger, T.; Ribeiro, L.; Bernhofer, C.; Foken, T.; Kohsiek, W.; Bruin, de, H.A.R.; Liu, H.

2007-01-01

The eddy-covariance method is the primary way of measuring turbulent fluxes directly. Many investigators have found that these flux measurements often do not satisfy a fundamental criterion¿closure of the surface energy balance. This study investigates to what extent the eddy-covariance measurement technology can be made responsible for this deficiency, in particular the effects of instrumentation or of the post-field data processing. Therefore, current eddy-covariance sensors and several pos...

NPY modulates PYY function in the regulation of energy balance and glucose homeostasis.

Science.gov (United States)

Zhang, L; Nguyen, A D; Lee, I-C J; Yulyaningsih, E; Riepler, S J; Stehrer, B; Enriquez, R F; Lin, S; Shi, Y-C; Baldock, P A; Sainsbury, A; Herzog, H

2012-08-01

Both the neuronal-derived neuropeptide Y (NPY) and the gut hormone peptide YY (PYY) have been implicated in the regulation of energy balance and glucose homeostasis. However, despite similar affinities for the same Y receptors, the co-ordinated actions of these two peptides in energy and glucose homeostasis remain largely unknown. To investigate the mechanisms and possible interactions between PYY with NPY in the regulation of these processes, we utilized NPY/PYY single and double mutant mouse models and examined parameters of energy balance and glucose homeostasis. PYY(-/-) mice exhibited increased fasting-induced food intake, enhanced fasting and oral glucose-induced serum insulin levels, and an impaired insulin tolerance, - changes not observed in NPY(-/-) mice. Interestingly, whereas PYY deficiency-induced impairment in insulin tolerance remained in NPY(-/-) PYY(-/-) mice, effects of PYY deficiency on fasting-induced food intake and serum insulin concentrations at baseline and after the oral glucose bolus were absent in NPY(-/-) PYY(-/-) mice, suggesting that NPY signalling may be required for PYY's action on insulin secretion and fasting-induced hyperphagia. Moreover, NPY(-/-) PYY(-/-) , but not NPY(-/-) or PYY(-/-) mice had significantly decreased daily food intake, indicating interactive control by NPY and PYY on spontaneous food intake. Furthermore, both NPY(-/-) and PYY(-/-) mice showed significantly reduced respiratory exchange ratio during the light phase, with no additive effects observed in NPY(-/-) PYY(-/-) mice, indicating that NPY and PYY may regulate oxidative fuel selection via partly shared mechanisms. Overall, physical activity and energy expenditure, however, are not significantly altered by NPY and PYY single or double deficiencies. These findings show significant and diverse interactions between NPY and PYY signalling in the regulation of different aspects of energy balance and glucose homeostasis. © 2012 Blackwell Publishing Ltd.

Equity and career-life balance in marine mammal science?

OpenAIRE

Hooker, Sascha K.; Simmons, Samantha E.; Stimpert, Alison K.; McDonald, Birgitte I.

2017-01-01

It is widely acknowledged that family and care-giving responsibilities are driving women away from Science, Technology, Engineering, and Mathematics (STEM) fields. Marine mammal science often incurs heavy fieldwork and travel obligations, which make it a challenging career in which to find work-life balance. This opinion piece explores gender equality, equity (the principles of fairness that lead to equality), and work-life balance in science generally and in this field in particular. We aim ...

FAST MAGNETIC FIELD AMPLIFICATION IN THE EARLY UNIVERSE: GROWTH OF COLLISIONLESS PLASMA INSTABILITIES IN TURBULENT MEDIA

Energy Technology Data Exchange (ETDEWEB)

Falceta-Gonçalves, D. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Kowal, G. [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, Rua Arlindo Bettio, 1000, São Paulo, SP 03828-000 (Brazil)

2015-07-20

In this work we report on a numerical study of the cosmic magnetic field amplification due to collisionless plasma instabilities. The collisionless magnetohydrodynamic equations derived account for the pressure anisotropy that leads, in specific conditions, to the firehose and mirror instabilities. We study the time evolution of seed fields in turbulence under the influence of such instabilities. An approximate analytical time evolution of the magnetic field is provided. The numerical simulations and the analytical predictions are compared. We found that (i) amplification of the magnetic field was efficient in firehose-unstable turbulent regimes, but not in the mirror-unstable models; (ii) the growth rate of the magnetic energy density is much faster than the turbulent dynamo; and (iii) the efficient amplification occurs at small scales. The analytical prediction for the correlation between the growth timescales and pressure anisotropy is confirmed by the numerical simulations. These results reinforce the idea that pressure anisotropies—driven naturally in a turbulent collisionless medium, e.g., the intergalactic medium, could efficiently amplify the magnetic field in the early universe (post-recombination era), previous to the collapse of the first large-scale gravitational structures. This mechanism, though fast for the small-scale fields (∼kpc scales), is unable to provide relatively strong magnetic fields at large scales. Other mechanisms that were not accounted for here (e.g., collisional turbulence once instabilities are quenched, velocity shear, or gravitationally induced inflows of gas into galaxies and clusters) could operate afterward to build up large-scale coherent field structures in the long time evolution.

Preliminary design characteristics of the RB fast-thermal core 'HERBE'

International Nuclear Information System (INIS)

Pesic, M.; Marinkovic, P.

1989-01-01

The 'RB' is zero power heavy water critical assembly designed in 1958 in Yugoslavia. The reactor operated using natural metal uranium, 2% enriched metal uranium, and 80% enriched UO 2 fuel of Soviet origin. A study of design of fast neutron fields began in 1976 and three fast neutron fields were designed up to 1983: the external neutron converter, the experimental fuel channel and the internal neutron converter, as the first step to fast-thermal coupled system. The preliminary design characteristics of the HERBE - a new fast - thermal core at the RB reactor are shown in this paper. (author)

Glycemic allostasis during mental activities on fasting in non alcohol ...

African Journals Online (AJOL)

Glycemic allostasis is the process by which blood glucose stabilization is achieved through the balancing of glucose consumption rate and release into the blood stream under a variety of stressors.This paper reviews findings on the dynamics of glycemic levels during mental activities on fasting in non‑alcohol users and ...

A regional field-based assessment of organic C sequestration and GHG balances in irrigated agriculture in Mediterranean semi-arid land

Science.gov (United States)

Virto, Inigo; Antón, Rodrigo; Arias, Nerea; Orcaray, Luis; Enrique, Alberto; Bescansa, Paloma

2016-04-01

In a context of global change and increasing food demand, agriculture faces the challenge of ensuring food security making a sustainable use of resources, especially arable land and water. This implies in many areas a transition towards agricultural systems with increased and stable productivity and a more efficient use of inputs. The introduction of irrigation is, within this framework, a widespread strategy. However, the C cycle and the net GHG emissions can be significantly affected by irrigation. The net effect of this change needs to be quantified at a regional scale. In the region of Navarra (NE Spain) more than 22,300 ha of rainfed agricultural land have been converted to irrigation in the last years, adding to the previous existing irrigated area of 70,000 ha. In this framework the project Life+ Regadiox (LIFE12 ENV/ES/000426, http://life-regadiox.es/) has the objective of evaluating the net GHG balances and atmospheric CO2 fixation rates of different management strategies in irrigated agriculture in the region. The project involved the identification of areas representative of the different pedocllimatic conditions in the region. This required soil and climate characterizations, and the design of a network of agricultural fields representative of the most common dryland and irrigation managements in these areas. This was done from available public datasets on climate and soil, and from soil pits especially sampled for this study. Two areas were then delimited, mostly based on their degree of aridity. Within each of those areas, fields were selected to allow for comparisons at three levels: (i) dryland vs irrigation, (ii) soil and crop management systems for non-permanent crops, and (iii) soil management strategies for permanent crops (namely olive orchards and vineyards). In a second step, the objective of this work was to quantify net SOC variations and GHG balances corresponding to the different managements identified in the previous step. These

Comparative impacts of Tai Chi, balance training, and a specially-designed yoga program on balance in older fallers.

Science.gov (United States)

Ni, Meng; Mooney, Kiersten; Richards, Luca; Balachandran, Anoop; Sun, Mingwei; Harriell, Kysha; Potiaumpai, Melanie; Signorile, Joseph F

2014-09-01

To compare the effect of a custom-designed yoga program with 2 other balance training programs. Randomized controlled trial. Research laboratory. A group of older adults (N=39; mean age, 74.15 ± 6.99 y) with a history of falling. Three different exercise interventions (Tai Chi, standard balance training, yoga) were given for 12 weeks. Balance performance was examined during pre- and posttest using field tests, including the 8-foot up-and-go test, 1-leg stance, functional reach, and usual and maximal walking speed. The static and dynamic balances were also assessed by postural sway and dynamic posturography, respectively. Training produced significant improvements in all field tests (Ptime × group interaction were not detected. For postural sway, significant decreases in the area of the center of pressure with eyes open (P=.001) and eyes closed (P=.002) were detected after training. For eyes open, maximum medial-lateral velocity significantly decreased for the sample (P=.013). For eyes closed, medial-lateral displacement decreased for Tai Chi (Ptime on the test (P=.006), and 2 linear measures in lateral (P=.001) and anterior-posterior (P<.001) directions were seen for the sample. Yoga was as effective as Tai Chi and standard balance training for improving postural stability and may offer an alternative to more traditional programs. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Warfighter Physiological Status Monitoring (WPSM): Energy Balance and Thermal Status During a 10-Day Cold Weather U.S. Marine Corps Infantry Officer Course Field Exercise

National Research Council Canada - National Science Library

Hoyt, Reed

2001-01-01

...) during a 10-day field exercise (FEX) at Quantico, VA. Question: Does intense physical activity, limited sleep, and restricted rations, combined with cold/damp weather, result in excessively negative energy balance and hypothermia? Methods...

Effects of buried high-Z layers on fast electron propagation

International Nuclear Information System (INIS)

Yang, Xiaohu; Zhuo, Hongbin; Ma, Yanyun; Shao, Fuqiu; Xu, Han; Yin Yan; Borghesi, M.

2014-01-01

The transport through high density plasmas of relativistic electron beams generated by ultra-intense laser-plasma interaction has potential applications in laser-driven ion acceleration and in the fast igniter scheme for inertial confinement fusion. By extending a prior model [A.R. Bell, J.R. Davies, S.M. Guerin, Phys. Rev. E 58, 2471 (1998)], the magnetic field generated during the transport of a fast electron beam driven by an ultra-intense laser in a solid target is derived analytically and applied to estimate the effect of such field on fast electron propagation through a buried high-Z layer in a lower-Z target. It is found that the effect gets weaker with the increase of the depth of the buried layer, the divergence of the fast electrons, and the laser intensity, indicating that magnetic field effects on the fast electron divergence as measured from K a X-ray emission may need to be considered for moderate laser intensities. On the basis of the calculations, some considerations are made on how one can mitigate the effect of the magnetic field generated at the interface. (authors)

Fast Aerial Video Stitching

Directory of Open Access Journals (Sweden)

Jing Li

2014-10-01

Full Text Available The highly efficient and robust stitching of aerial video captured by unmanned aerial vehicles (UAVs is a challenging problem in the field of robot vision. Existing commercial image stitching systems have seen success with offline stitching tasks, but they cannot guarantee high-speed performance when dealing with online aerial video sequences. In this paper, we present a novel system which has an unique ability to stitch high-frame rate aerial video at a speed of 150 frames per second (FPS. In addition, rather than using a high-speed vision platform such as FPGA or CUDA, our system is running on a normal personal computer. To achieve this, after the careful comparison of the existing invariant features, we choose the FAST corner and binary descriptor for efficient feature extraction and representation, and present a spatial and temporal coherent filter to fuse the UAV motion information into the feature matching. The proposed filter can remove the majority of feature correspondence outliers and significantly increase the speed of robust feature matching by up to 20 times. To achieve a balance between robustness and efficiency, a dynamic key frame-based stitching framework is used to reduce the accumulation errors. Extensive experiments on challenging UAV datasets demonstrate that our approach can break through the speed limitation and generate an accurate stitching image for aerial video stitching tasks.

Force balance near an X line along which E x J is less than 0. [plasma transfer from closed to open field lines in geomagnetic tail

Science.gov (United States)

Lyons, L. R.; Pridmore-Brown, D. C.

1992-01-01

Conditions for which particle motion within the current sheet in the vicinity of an X line can give a current in the direction appropriate for E x J is less than 0. The way in which the balance between gyroviscosity and the electric force along an X line is maintained for any E x J is shown. It is concluded that observational evidence for the occasional existence of E x J is less than 0 along an X line provides support for the suggestion that collisionless graviscosity, rather than resistivity, balances the electric force along an X line. It is found that there is a maximum electric field magnitude for particles to be able to carry a significant current. For parameters typical of the distant magnetotail, the critical electric field magnitude was found to be about 0.15 mV/m, which is of the order of, though somewhat less than, the potential electric field magnitudes expected in the magnetotail. This maximum allowable field magnitude is about the same for protons as it is for electrons in the magnetotail.

Water and salt balance in young male football players in training during the holy month of Ramadan.

Science.gov (United States)

Shirreffs, Susan M; Maughan, Ronald J

2008-12-01

The aim of this study was to assess water and salt balance in young football players in training during Ramadan. Measurements were made in 92 young male football players before and during the month of Ramadan. Fifty-five participants were observing Ramadan fasting, while the other 37 participants were eating and drinking without restriction. In week 3 of Ramadan, water and salt balance measures were made during a training session of 60-70 min duration that was performed at an ambient temperature of 25-28 degrees C and relative humidity of 50-53%. Body mass was recorded before and after training. Fluid intake was assessed in non-fasting players by weighing drink bottles before and after training, and the volume of any urine output was recorded. Sweat composition was estimated from absorbent patches applied to four skin sites for the duration of training. Mean sweat loss of players amounted to 1.41 litres (s = 0.36) in fasting players and 1.61 litres (s = 0.51) in non-fasting players (P = 0.038). Mean fluid intake during training in non-fasting players was 1.92 litres (s = 0.66). Sweat sodium concentration was 20 mmol . l(-1) (s = 8) in fasting players and 17 mmol . l(-1) (s = 7) in non-fasting players, and total sweat sodium loss during training was 0.67 g (s = 0.41) and 0.65 g (s = 0.37) [corresponding to a salt loss of 1.7 g (s = 1.1) and 1.7 g (s = 0.9)] respectively, with no difference between fasting and non-fasting players. Sweat sodium loss was not related to estimated dietary sodium intake (r = -0.07). These descriptive data show large individual variations in all measured parameters with relatively little difference in sweat parameters between fasting and non-fasting individuals.

Energy balance and photochemical processes in the inner coma

International Nuclear Information System (INIS)

Huebner, W.F.; Keady, J.J.

1982-01-01

Energy balance and multifluid flow in the coma are described. Expansion cooling, radiative cooling, photodissociative heating, chemical heating, and relative multifluid flow are the processes determining the energy budget. In the fluid dynamics, fast atomic and molecular hydrogen are considered as separate fluids with larger collision mean free paths than the cold bulk fluid that has a larger mean molecular weight. The transition from fluid flow to free molecular flow is approximated. The model predicts hydrogen and bulk fluid flow velocities in general agreement with observations. The effects of the temperature profile and the fast hydrogen flow on the chemistry in the inner coma are investigated. Results from a model approximating conditions in Halley's comet are presented

Watt and joule balances

Science.gov (United States)

Robinson, Ian A.

2014-04-01

The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated

Adverse health effects associated with Islamic fasting -A literature review

Directory of Open Access Journals (Sweden)

Nania Mohamed Pakkir Maideen

2017-09-01

Full Text Available Introduction: Millions of Muslims across the world observe Islamic fasting during the holy month of Ramadan, as well as the other specific dates in the lunar calendar year. While fasting during this month, Muslims refrain from eating or drinking from dawn to dusk. Islamic fasting is similar to alternate day fasting (ADF since it incorporates an average of 12 hours of fasting and 12 hours of feasting periods. This present review study is aimed to find out the common adverse health effects associated with Islamic fasting and the preventive measures to be followed to avoid them. Methods: The literature was reviewed through searching in databases such as PubMed, Google Scholar, and reference lists to identify the related articles. Results: Many health benefits have been attributed to Islamic fasting, including the reduced risk of cardiovascular diseases, diabetes, cancer, hypertension, and asthma. On the other hand, some studies have mentioned a few health problems associated with Islamic fasting, such as headaches, heartburn, constipation, dehydration, decreased sleep quality, and anemia, which may occur in some fasting individuals during Ramadan. Conclusion: Islamic fasting could be beneficial for health if it is performed correctly. During Ramadan, fasting individuals are advised to adhere to a balanced diet that contains sufficient portions of fruits and vegetables, whole grains, pulses, meat, fish, milk, and dairy products. Moreover, fasting individuals must drink adequate fluids, such as water, fresh fruit juices, and soups, in order to prevent the possible adverse health effects associated with Islamic fasting.

Magnetically Assisted Fast Ignition

OpenAIRE

Wang, W.-M.; Gibbon, P.; Sheng, Z.-M.; Li, Y.-T.

2015-01-01

Fast ignition (FI) is investigated via integrated particle-in-cell simulation including both generation andtransport of fast electrons, where petawatt ignition lasers of 2 ps and compressed targets of a peak density of300 g cm−3 and areal density of 0.49 g cm−2 at the core are taken. When a 20 MG static magnetic field isimposed across a conventional cone-free target, the energy coupling from the laser to the core is enhancedby sevenfold and reaches 14%. This value even exceeds that obtained u...

Coil motion effects in watt balances: a theoretical check

Science.gov (United States)

Li, Shisong; Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Pratt, Jon R.

2016-04-01

A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was historically used to realize the unit of current in terms of the kilogram, the watt balance relates electrical and mechanical units through a virtual power measurement and has far greater precision. However, because the virtual power measurement requires the execution of a prescribed motion of a coil in a fixed magnetic field, systematic errors introduced by horizontal and rotational deviations of the coil from its prescribed path will compromise the accuracy. We model these potential errors using an analysis that accounts for the fringing field in the magnet, creating a framework for assessing the impact of this class of errors on the uncertainty of watt balance results.

Flexible Assembly Solar Technology (FAST) Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Toister, Elad [BrightSource Energy Inc., Jerusalem (Israel)

2014-11-06

The Flexible Assembly Solar Technology (FAST) project was initiated by BrightSource in an attempt to provide potential solar field EPC contractors with an effective set of tools to perform specific construction tasks. These tasks are mostly associated with heliostat assembly and installation, and require customized non-standard tools. The FAST concept focuses on low equipment cost, reduced setup time and increased assembly throughput as compared to the Ivanpah solar field construction tools.

What is the future for fast reactor technology?

International Nuclear Information System (INIS)

Kraev, Kamen

2017-01-01

NucNet spoke to Vladimir Kriventsev, team leader for fast reactor technology development at the International Atomic Energy Agency (IAEA), about the possibilities and challenges of technology development in the fast reactor sector. Today, the field of fast reactors is vibrant and full of fascinating developments, some which will have an impact in the nearer term and others in the longer term.

What is the future for fast reactor technology?

Energy Technology Data Exchange (ETDEWEB)

Kraev, Kamen [NucNet, Brussels (Belgium). The Independent Global Nuclear News Agency

2017-08-15

NucNet spoke to Vladimir Kriventsev, team leader for fast reactor technology development at the International Atomic Energy Agency (IAEA), about the possibilities and challenges of technology development in the fast reactor sector. Today, the field of fast reactors is vibrant and full of fascinating developments, some which will have an impact in the nearer term and others in the longer term.

Review of fast reactor activities

International Nuclear Information System (INIS)

1982-01-01

A description of some highlights of the activities performed by the Commission of the European Communities in the field of fast reactors is given. They fall into two categories: coordinating and harmonizing activities and research activities. The former are essentially performed in the frame of the Fast Reactor Coordinating Committee (FRCC), the latter in the Commission's Joint Research Center and to some extent under contract in research centers of the Member States

Non-Maxwellian fast particle effects in gyrokinetic GENE simulations

Science.gov (United States)

Di Siena, A.; Görler, T.; Doerk, H.; Bilato, R.; Citrin, J.; Johnson, T.; Schneider, M.; Poli, E.; JET Contributors

2018-04-01

Fast ions have recently been found to significantly impact and partially suppress plasma turbulence both in experimental and numerical studies in a number of scenarios. Understanding the underlying physics and identifying the range of their beneficial effect is an essential task for future fusion reactors, where highly energetic ions are generated through fusion reactions and external heating schemes. However, in many of the gyrokinetic codes fast ions are, for simplicity, treated as equivalent-Maxwellian-distributed particle species, although it is well known that to rigorously model highly non-thermalised particles, a non-Maxwellian background distribution function is needed. To study the impact of this assumption, the gyrokinetic code GENE has recently been extended to support arbitrary background distribution functions which might be either analytical, e.g., slowing down and bi-Maxwellian, or obtained from numerical fast ion models. A particular JET plasma with strong fast-ion related turbulence suppression is revised with these new code capabilities both with linear and nonlinear gyrokinetic simulations. It appears that the fast ion stabilization tends to be less strong but still substantial with more realistic distributions, and this improves the quantitative power balance agreement with experiments.

Preservation of potassium balance is strongly associated with insect cold tolerance in the field: a seasonal study of Drosophila subobscura.

Science.gov (United States)

MacMillan, Heath A; Schou, Mads F; Kristensen, Torsten N; Overgaard, Johannes

2016-05-01

There is interest in pinpointing genes and physiological mechanisms explaining intra- and interspecific variations in cold tolerance, because thermal tolerance phenotypes strongly impact the distribution and abundance of wild animals. Laboratory studies have highlighted that the capacity to preserve water and ion homeostasis is linked to low temperature survival in insects. It remains unknown, however, whether adaptive seasonal acclimatization in free-ranging insects is governed by the same physiological mechanisms. Here, we test whether cold tolerance in field-caught Drosophila subobscura is high in early spring and lower during summer and whether this transition is associated with seasonal changes in the capacity of flies to preserve water and ion balance during cold stress. Indeed, flies caught during summer were less cold tolerant, and exposure of these flies to sub-zero temperatures caused a loss of haemolymph water and increased the concentration of K(+) in the haemolymph (as in laboratory-reared insects). This pattern of ion and water balance disruption was not observed in more cold-tolerant flies caught in early spring. Thus, we here provide a field verification of hypotheses based on laboratory studies and conclude that the ability to maintain ion homeostasis is important for the ability of free-ranging insects to cope with chilling. © 2016 The Author(s).

Line Balancing Using Largest Candidate Rule Algorithm In A Garment Industry: A Case Study

Directory of Open Access Journals (Sweden)

V. P.Jaganathan

2014-12-01

Full Text Available The emergence of fast changes in fashion has given rise to the need to shorten production cycle times in the garment industry. As effective usage of resources has a significant effect on the productivity and efficiency of production operations, garment manufacturers are urged to utilize their resources effectively in order to meet dynamic customer demand. This paper focuses specifically on line balancing and layout modification. The aim of assembly line balance in sewing lines is to assign tasks to the workstations, so that the machines of the workstation can perform the assigned tasks with a balanced loading. Largest Candidate Rule Algorithm (LCR has been deployed in this paper.

NMR relaxation in natural soils: Fast Field Cycling and T1-T2 Determination by IR-MEMS

Science.gov (United States)

Haber-Pohlmeier, S.; Pohlmeier, A.; Stapf, S.; van Dusschoten, D.

2009-04-01

Soils are natural porous media of highest importance for food production and sustainment of water resources. For these functions, prominent properties are their ability of water retainment and transport, which are mainly controlled by pore size distribution. The latter is related to NMR relaxation times of water molecules, of which the longitudinal relaxation time can be determined non-invasively by fast-field cycling relaxometry (FFC) and both are obtainable by inversion recovery - multi-echo- imaging (IR-MEMS) methods. The advantage of the FFC method is the determination of the field dependent dispersion of the spin-lattice relaxation rate, whereas MRI at high field is capable of yielding spatially resolved T1 and T2 times. Here we present results of T1- relaxation time distributions of water in three natural soils, obtained by the analysis of FFC data by means of the inverse Laplace transformation (CONTIN)1. Kaldenkirchen soil shows relatively broad bimodal distribution functions D(T1) which shift to higher relaxation rates with increasing relaxation field. These data are compared to spatially resolved T1- and T2 distributions, obtained by IR-MEMS. The distribution of T1 corresponds well to that obtained by FFC.

Carbon balances during land conversion in early bioenergy systems

Science.gov (United States)

Zenone, T.; Chen, J.; Gelfand, I.; Robertson, G. P.; Hamilton, S. K.

2012-12-01

In this study, we established a field experiment and deployed seven eddy-covariance towers to quantify the roles of land use change and the subsequent carbon (C) balances of three different bioenergy systems (corn, switchgrass, and mixed prairie species) that were developed from two historical land use types: monocultural grasslands dominated by smooth brome (Bromus inermis Leyss) and lands in the Conservation Reserve Program (CRP). Three CRP fields and three cropland fields were converted to soybean in 2009 (conversion year) before establishing the cellulosic biofuel cropping systems in 2010 (establishment year). A CRP perennial grassland site was kept undisturbed as a reference. Conversion of CRP to soybean induced net C emissions during the conversion year (134 -262 g C m-2 yr-1), while in the same year the net C balance at the CRP grassland reference was -35 g C m-2 yr-1 (i.e., net C sequestration). The establishment of switchgrass and mixed prairie induced a cumulative C balance of -113 g C m-2 (switchgrass from CRP), 250 g C m-2 (switchgrass from cropland), 706 g C m-2 (mixed prairie from CRP), and 59 g C m-2 (mixed prairie from cropland) over the three-year study period. The cumulative three-year C balance of corn converted from CRP and from cropland was -151 g C m-2 and -183 g C m-2, respectively. Eddy flux measurements during cellulosic biofuel crop establishment reveal annual changes in C balance that cannot be detected using conventional mass balance approaches. When end-use of harvested biomass was considered, the C balances for all studied systems, except the reference site, exhibited large C emissions ranging from 150 to 990 g C m-2 over the three-year conversion phase.

Earth's magnetic field enabled scalar coupling relaxation of 13C nuclei bound to fast-relaxing quadrupolar 14N in amide groups.

Science.gov (United States)

Chiavazza, Enrico; Kubala, Eugen; Gringeri, Concetta V; Düwel, Stephan; Durst, Markus; Schulte, Rolf F; Menzel, Marion I

2013-02-01

Scalar coupling relaxation, which is usually only associated with closely resonant nuclei (e.g., (79)Br-(13)C), can be a very effective relaxation mechanism. While working on hyperpolarized [5-(13)C]glutamine, fast liquid-state polarization decay during transfer to the MRI scanner was observed. This behavior could hypothetically be explained by substantial T(1) shortening due to a scalar coupling contribution (type II) to the relaxation caused by the fast-relaxing quadrupolar (14)N adjacent to the (13)C nucleus in the amide group. This contribution is only effective in low magnetic fields (i.e., less than 800 μT) and prevents the use of molecules bearing the (13)C-amide group as hyperpolarized MRS/MRI probes. In the present work, this hypothesis is explored both theoretically and experimentally. The results show that high hyperpolarization levels can be retained using either a (15)N-labeled amide or by applying a magnetic field during transfer of the sample from the polarizer to the MRI scanner. Copyright © 2012 Elsevier Inc. All rights reserved.

Alignment of the NPL Mark II watt balance

International Nuclear Information System (INIS)

Robinson, I A

2012-01-01

To reach uncertainties in the region of 1 part in 10 8 a moving-coil watt balance not only requires the accurate measurement of voltage, resistance, velocity, mass and the acceleration due to gravity but, in addition, requires the apparatus to be adjusted correctly to minimize the second order effects which can reduce the accuracy of the measurement. This paper collects together the alignment and correction techniques that have been developed at NPL over many years and are required to minimize the uncertainty of the measurement. Some of these techniques are applicable to all watt balances, whilst a few are specific to watt balances that employ a conventional beam balance to support a circular coil in a radial magnetic field, such as the NPL Mark II watt balance, now known as the NRC watt balance. (paper)

Status of national programmes on fast reactors 1997/98. 31. annual meeting of the International Working Group on Fast Reactors

International Nuclear Information System (INIS)

1998-01-01

The objective of the meeting was to co-ordinate the exchange of information on the status of fast reactor development and operational experience, including experience with experimental types of reactor; to consider meeting arrangements for 1998 and 1999; and to review the IAEA co-ordinated research activities in the field of fast reactor, as well as co-ordination of the International Working Group on Fast Reactors activities with other organizations

Flexural properties of four fast-growing eucalypts woods deteriorated by three different field tests

Directory of Open Access Journals (Sweden)

Rafael de Avila Delucis

2017-02-01

Full Text Available Durability is a wood characteristic determined by several factors, making it difficult to investigate the service life of pieces designated for outdoor use. In this study, the decaying of juvenile and adult woods of four fast-growing eucalypts from southern Brazil subjected to three different exposure environments was monitored through mechanical properties (flexural test. The study material was obtained from adult trees of Eucalyptus botryoides, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus tereticornis. Field tests were conducted in the city of Piratini, southern Brazil, and samplings were carried out during 540 days of experiment. Comparing the four eucalypts, the decreasing order of biological resistance was: Eucalyptus tereticornis, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus botryoides. The mature wood showed greater and more stable physical-mechanical properties than juvenile wood.

Effect of manual therapy versus proprioceptive neuromuscular facilitation in dynamic balance, mobility and flexibility in field hockey players. A randomized controlled trial.

Science.gov (United States)

Espí-López, Gemma V; López-Martínez, Susana; Inglés, Marta; Serra-Añó, Pilar; Aguilar-Rodríguez, Marta

2018-04-22

To compare the effectiveness of a specific Manual Therapy (MT) protocol applied to field hockey players (FHP), versus a Proprioceptive Neuromuscular Facilitation (PNF) protocol, in the improvement of dynamic balance, active range of movement and lumbar flexibility one-week and four-weeks after the treatment. Randomized controlled trial. Participants were assigned to 2 groups: MT and PNF. 30 min' sessions were performed once a week for three weeks. Three evaluations were performed: basal, one-week and four-weeks post-treatment. University of Valencia (Spain). 22 in MT group and 20 in PNF group. Dynamic Balance, measured with Star Excursion Balance Test; Active Range of Motion (ROM), using a manual goniometer and Lumbar Flexibility, assessed with Fingertip-to-floor test. Both groups significantly improved in lateral and medial dynamic balance one-week post-treatment (p < 0.05); but the improvement in the MT group lasted until the fourth-week after treatment in both reaches (lateral and medial) (p < 0.05). MT group also obtained significant improvements in dorsal flexion of the ankle in the fourth-week post-treatment (p < 0.05) and in lumbar flexibility one-week post-treatment (p < 0.05). MT and PNF improve dynamic balance one-week post-treatment; however, the improvement obtained through MT is maintained four-weeks later. Only MT improves dorsal flexion of the ankle four-weeks post-treatment and lumbar flexibility one-week post-treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Carbon Balance in an Irrigated Corn Field after Inorganic Fertilizer or Manure Application

Science.gov (United States)

Lentz, R. D.; Lehrsch, G. A.

2014-12-01

Little is known about inorganic fertilizer or manure effects on organic carbon (OC) and inorganic C (IC) losses from a furrow irrigated field, particularly in the context of other system C gains or losses. In 2003 and 2004, we measured dissolved organic and inorganic C (DOC, DIC), particulate OC and IC (POC, PIC) concentrations in irrigation inflow, runoff, and percolation waters (6-7 irrigations/y); C inputs from soil amendments and crop biomass; harvested C; and gaseous C emissions from field plots cropped to silage corn (Zea mays L.) in southern Idaho. Annual treatments included: (M) 13 (y 1) and 34 Mg/ha (y 2) stockpiled dairy manure; (F) 78 (yr 1) and 195 kg N/ha (y 2) inorganic N fertilizer; or (NA) no amendment--control. The mean annual total C input into M plots averaged 16.1 Mg/ha, 1.4-times greater than that for NA (11.5 Mg/ha) or F (11.1 Mg/ha), while total C outputs for the three treatments were similar, averaging 11.8 Mg/ha. Thus, the manure plots ended each growing season with an average net gain of 3.8 Mg C/ha (a positive net C flux), while the control (-0.5 Mg C/ha) and fertilizer (-0.4 Mg C/ha) treatments finished the season with a net C loss. Atmospheric CO2 incorporated into the crop biomass contributed 96% of the mean annual C input to NA and F plots but only 68% to M plots. We conclude that nutrient amendments substantially influence the short-term carbon balance of our furrow-irrigated system. Amendments had both direct and indirect influences on individual C components, such as the losses of DIC and POC in runoff and DOC in percolation water, producing temporally complex outcomes which may depend on environmental conditions external to the field.

Static and dynamic balance ability, lumbo-pelvic movement control and injury incidence in cricket pace bowlers.

Science.gov (United States)

Olivier, B; Stewart, A V; Olorunju, S A S; McKinon, W

2015-01-01

This study aimed to establish the difference in lumbo-pelvic movement control, static and dynamic balance at the start and at the end of a cricket season in pace bowlers who sustained an injury during the season and those who did not. This is a longitudinal, observational study. Thirty-two, healthy, injury free, male premier league fast, fast-medium and medium pace bowlers between the ages of 18 and 26 years (mean age 21.8 years, standard deviation 1.8 years) participated in the study. The main outcome measures were injury incidence, lumbo-pelvic movement control, static and dynamic balance ability. Fifty-three percent of the bowlers (n=17) sustained injuries during the reviewed cricket season. Lumbo-pelvic movement control tests could not discriminate between bowlers who sustained an injury during the cricket season and bowlers who did not. However, performance in the single leg balance test (p=0.03; confidence interval 4.74-29.24) and the star excursion balance test (p=0.02; confidence interval 1.28-11.93) as measured at the start of the season was better in bowlers who did not sustain an injury during the season. The improvement in the lumbo-pelvic movement control and balance tests suggests that the intensity and type of physical conditioning that happens throughout the season may have been responsible for this improvement. Poor performance in the single leg balance test and the star excursion balance test at the start of the cricket season may be an indication that a bowler is at heightened risk of injury. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

PeerFlow: Secure Load Balancing in Tor

Directory of Open Access Journals (Sweden)

Johnson Aaron

2017-04-01

Full Text Available We present PeerFlow, a system to securely load balance client traffic in Tor. Security in Tor requires that no adversary handle too much traffic. However, Tor relays are run by volunteers who cannot be trusted to report the relay bandwidths, which Tor clients use for load balancing. We show that existing methods to determine the bandwidths of Tor relays allow an adversary with little bandwidth to attack large amounts of client traffic. These methods include Tor’s current bandwidth-scanning system, TorFlow, and the peer-measurement system EigenSpeed. We present an improved design called PeerFlow that uses a peer-measurement process both to limit an adversary’s ability to increase his measured bandwidth and to improve accuracy. We show our system to be secure, fast, and efficient. We implement PeerFlow in Tor and demonstrate its speed and accuracy in large-scale network simulations.

Impacts of lost fast ions on the TJ-II Vacuum Vessel during NBI

International Nuclear Information System (INIS)

Guasp, J.

1995-01-01

The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed. (Author) 6 refs

Impacts of lost fast ions on the TJ-II Vacuum vessel during NBI

International Nuclear Information System (INIS)

Guasp, J.

1995-09-01

The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed

Balanced growth path solutions of a Boltzmann mean field game model for knowledge growth

KAUST Repository

Burger, Martin; Lorz, Alexander; Wolfram, Marie Therese

2016-01-01

events or by producing goods with the knowledge they already have. The existence of balanced growth path solutions implies exponential growth of the overall production in time. We prove existence of balanced growth path solutions if the initial

Hatha yoga on body balance

Science.gov (United States)

Prado, Erick Tadeu; Raso, Vagner; Scharlach, Renata Coelho; Kasse, Cristiane Akemi

2014-01-01

Background: A good body balance requires a proper function of vestibular, visual, and somatosensory systems which can be reach with exercise practice and/or yoga. Aim: To determine the effects of a 5-month hatha yoga training program on body balance in young adults. Materials and Methods: This study used a controlled, nonrandomized design, where the experimental group underwent a 5-month training program and were then compared with the control group that had a sedentary lifestyle. A convenience sample of 34 out of 40 men aged 25-55 years old (34.0 ± 0.9) were deemed eligible for this study. They were randomly divided into two groups: Experimental and control groups. Subjects in the experimental group were engaged in 60 min sessions of hatha yoga three times a week for 5 months. We evaluated postural control by measuring the limit of stability and velocity of oscillation (VOS) in three conditions of the balance rehabilitation unit (BRU) and through field procedures (four position, plane, flamingo, hopscotch, and dynamic test). Results: We observed differences (P < 0.05) in postintervention scores between the groups regardless of BRU parameters and field procedures (except for flamingo) even after adjusting for preintervention scores, suggesting that these changes were induced by hatha yoga training. The partial eta squared on BRU parameters ranged from 0.78 (VOS1)-0.97 (COP2), and from 0.00 (flamingo)-0.94 (four position) for the field procedures. Conclusions: Our results provide substantial evidence that postural control in healthy young adults can be improved through practicing hatha yoga. PMID:25035623

Fast-electron self-collimation in a plasma density gradient

International Nuclear Information System (INIS)

Yang, X. H.; Borghesi, M.; Robinson, A. P. L.

2012-01-01

A theoretical and numerical study of fast electron transport in solid and compressed fast ignition relevant targets is presented. The principal aim of the study is to assess how localized increases in the target density (e.g., by engineering of the density profile) can enhance magnetic field generation and thus pinching of the fast electron beam through reducing the rate of temperature rise. The extent to which this might benefit fast ignition is discussed.

Theoretical and experimental investigation of a balanced phase-locked loop based clock recovery at a bit rate of 160 Gb/s

DEFF Research Database (Denmark)

Zibar, Darko; Oxenløwe, Leif Katsuo; Clausen, Anders

2003-01-01

This paper describes a mathematical model of a balanced opto-electronic phase-locked loop (OPLL), which is required to be very fast for some network applications. OPLL is investigated in terms of clock pulse width, loop filter gain and residuals of the balancing DC level. Based on the guidelines ...

Tucurui`s 500 kV S F{sub 6} gas-insulated substation modeling for fast transients - field tests comparison

Energy Technology Data Exchange (ETDEWEB)

Lima Filho, Joao Ferreira de; Pazo Blanco, Flavio A.F.; D` Ajuz, Ary; Nascimento, Lidio F.A. [ELETRONORTE, Brasilia, DF (Brazil)

1994-12-31

Many problems in insulation, devices and equipment have been resulted from switching operations in the 500 kV Gas-Insulated Substation (GIS) of Tucurui power plant. Disconnector closing or opening action can subject the GIS components to great stresses from excessive voltages at high frequencies caused by successive reflections of travelling waves at discontinuities (1,2,3). Field tests were carried out in September 18-23, 1991 to verify the actual GIS stresses at Tucurui. From these results simulations on the Alternative Transients Program (ATP) were performed in order to check the substation modeling. This paper presents and discusses the Tucurui GIS modeling for switching fast transients and its field test validation. (author) 8 refs., 6 figs.

Seismic responses of a pool-type fast reactor with different core support designs

International Nuclear Information System (INIS)

Wu, Ting-shu; Seidensticker, R.W.

1989-01-01

In designing the core support system for a pool-type fast reactor, there are many issues which must be considered in order to achieve an optimum and balanced design. These issues include safety, reliability, as well as costs. Several design options are possible to support the reactor core. Different core support options yield different frequency ranges and responses. Seismic responses of a large pool-type fast reactor incorporated with different core support designs have been investigated. 4 refs., 3 figs

Fast Geodesic Active Fields for Image Registration Based on Splitting and Augmented Lagrangian Approaches.

Science.gov (United States)

Zosso, Dominique; Bresson, Xavier; Thiran, Jean-Philippe

2014-02-01

In this paper, we present an efficient numerical scheme for the recently introduced geodesic active fields (GAF) framework for geometric image registration. This framework considers the registration task as a weighted minimal surface problem. Hence, the data-term and the regularization-term are combined through multiplication in a single, parametrization invariant and geometric cost functional. The multiplicative coupling provides an intrinsic, spatially varying and data-dependent tuning of the regularization strength, and the parametrization invariance allows working with images of nonflat geometry, generally defined on any smoothly parametrizable manifold. The resulting energy-minimizing flow, however, has poor numerical properties. Here, we provide an efficient numerical scheme that uses a splitting approach; data and regularity terms are optimized over two distinct deformation fields that are constrained to be equal via an augmented Lagrangian approach. Our approach is more flexible than standard Gaussian regularization, since one can interpolate freely between isotropic Gaussian and anisotropic TV-like smoothing. In this paper, we compare the geodesic active fields method with the popular Demons method and three more recent state-of-the-art algorithms: NL-optical flow, MRF image registration, and landmark-enhanced large displacement optical flow. Thus, we can show the advantages of the proposed FastGAF method. It compares favorably against Demons, both in terms of registration speed and quality. Over the range of example applications, it also consistently produces results not far from more dedicated state-of-the-art methods, illustrating the flexibility of the proposed framework.

Global properties of ohmically heated reversed-field pinches

International Nuclear Information System (INIS)

Gerwin, R.A.

The simultaneous requirements of power balance and pressure balance have been considered. The treatment generalizes the Pease-Braginskii pinch current limit by including toroidal magnetic field, anomalous resistivity, nonradiative losses, and time-dependent fields. The rise of the temperature to a state of power balance proves to be amenable to a very simple and unified description. Finally, the practical parameter windows implied by the joint action of power balance and pressure balance are displayed

Ultra-fast silicon detectors

Energy Technology Data Exchange (ETDEWEB)

Sadrozinski, H. F.-W., E-mail: hartmut@scipp.ucsc.edu [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Ely, S.; Fadeyev, V.; Galloway, Z.; Ngo, J.; Parker, C.; Petersen, B.; Seiden, A.; Zatserklyaniy, A. [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Cartiglia, N.; Marchetto, F. [INFN Torino, Torino (Italy); Bruzzi, M.; Mori, R.; Scaringella, M.; Vinattieri, A. [University of Florence, Department of Physics and Astronomy, Sesto Fiorentino, Firenze (Italy)

2013-12-01

We propose to develop a fast, thin silicon sensor with gain capable to concurrently measure with high precision the space (∼10 μm) and time (∼10 ps) coordinates of a particle. This will open up new application of silicon detector systems in many fields. Our analysis of detector properties indicates that it is possible to improve the timing characteristics of silicon-based tracking sensors, which already have sufficient position resolution, to achieve four-dimensional high-precision measurements. The basic sensor characteristics and the expected performance are listed, the wide field of applications are mentioned and the required R and D topics are discussed. -- Highlights: •We are proposing thin pixel silicon sensors with 10's of picoseconds time resolution. •Fast charge collection is coupled with internal charge multiplication. •The truly 4-D sensors will revolutionize imaging and particle counting in many applications.

Fast Neutral Pressure Gauges in NSTX

International Nuclear Information System (INIS)

Raman, R.; Kugel, H.W.; Gernhardt, R.; Provost, T.; Jarboe, T.R.; Soukhanovskii, V.

2004-01-01

Successful operation in NSTX of two prototype fast-response micro ionization gauges during plasma operations has motivated us to install five gauges at different toroidal and poloidal locations to measure the edge neutral pressure and its dependence on the type of discharge (L-mode, H-mode, CHI) and the fueling method and location. The edge neutral pressure is also used as an input to the transport analysis codes TRANSP and DEGAS-2. The modified PDX-type Penning gauges are well suited for pressure measurements in the NSTX divertor where the toroidal field is relatively high. Behind the NSTX outer divertor plates where the field is lower, an unshielded fast ion gauge of a new design has been installed. This gauge was developed after laboratory testing of several different designs in a vacuum chamber with applied magnetic fields

Impairments in static standing balance are highly prevalent among older adults receiving home-based physical therapy.

Science.gov (United States)

Bohannon, Richard W

2012-01-01

Measures of balance are an important component of the physical therapist examination. This study investigated the usefulness of timed static stance durations for identifying balance impairments among patients receiving home-based physical therapy. This study involved the retrospective retrieval of data from the records of 48 patients at least 60 years of age. Their balance was measured under 3 foot configurations; that is, feet apart, feet together, and on each foot. Every patient demonstrated impaired standing balance. Most, but not all could balance 30 seconds with the feet apart or together. Only 19 could maintain balance on each of both feet. Of those who could so balance, none was able to achieve the average time of normal individuals of comparable age. Although not able to identify all aspects of balance, timed durations of stance under different configurations demonstrate a high prevalence of balance impairments among patients receiving home-based physical therapy. As the tests are objective, fast, and require little space, they can be advocated in such a setting.

Conditions for substorm onset by the fast reconnection mechanism

Directory of Open Access Journals (Sweden)

M. Ugai

2008-12-01

Full Text Available The fast reconnection mechanism, involving slow shocks and Alfvénic fast plasma jets, is most responsible for the explosive conversion of magnetic energy associated with geomagnetic substorms and solar flares. In this paper, the spontaneous fast reconnection model is applied to well-known phenomena of substorms. When the east-west width of the tail current sheet becomes 3–4 times larger than its north-south thickness, the fast reconnection mechanism can fully be established, which may lead to substorm onset. The resulting Alfvénic jet can exactly explain, both qualitatively and quantitatively, the in-situ satellite observations of the traveling compression regions (TCRs associated with large-scale plasmoids propagating down the tail. Also, the earthward fast reconnection jet causes drastic magnetic field dipolarization, so that the sheet current ahead of the magnetic loop of closed field lines suddenly turns its direction toward the loop footpoint and a large-scale current wedge is formed according to the growth of field-aligned currents. It is demonstrated that an MHD generator arises ahead of the magnetic loop and drives the current wedge to distinctly enhance the current density in a pair of thin layers of the loop footpoint, giving rise to drastic heating in the form of two ribbons.

Long term continuous field survey to assess nutrient emission impact from irrigated paddy field into river catchment

Science.gov (United States)

Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

2017-04-01

In order to achieve good river environment, it is very important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. As we could reduce impact from urban and industrial activities by wastewater treatment, pollution from point sources are likely to be controlled. Besides them, nutrient emission from agricultural activity is dominant pollution source into the river system. In many countries in Asia and Africa, rice is widely cultivated and paddy field covers large areas. In Japan 54% of its arable land is occupied with irrigated paddy field. While paddy field can deteriorate river water quality due to fertilization, it is also suggested that paddy field can purify water. We carried out field survey in middle reach of the Tone River Basin with focus on a paddy field IM. The objectives of the research are 1) understanding of water and nutrient balance in paddy field, 2) data collection for assessing nutrient emission. Field survey was conducted from June 2015 to October 2016 covering two flooding seasons in summer. In our measurement, all input and output were measured regarding water, N and P to quantify water and nutrient balance in the paddy field. By measuring water quality and flow rate of inflow, outflow, infiltrating water, ground water and flooding water, we tried to quantitatively understand water, N and P cycle in a paddy field including seasonal trends, and changes accompanied with rainy events and agricultural activities like fertilization. Concerning water balance, infiltration rate was estimated by following equation. Infiltration=Irrigation water + Precipitation - Evapotranspiration -Outflow We estimated mean daily water balance during flooding season. Infiltration is 11.9mm/day in our estimation for summer in 2015. Daily water reduction depth (WRD) is sum of Evapotranspiration and Infiltration. WRD is 21.5mm/day in IM and agrees with average value in previous research. Regarding nutrient balance, we estimated an annual N and

Study on process design of partially-balanced, hydraulically lifting vertical ship lift

Science.gov (United States)

Xin, Shen; Xiaofeng, Xu; Lu, Zhang; Bing, Zhu; Fei, Li

2017-11-01

The hub ship lift in Panjin is the first navigation structure in China for the link between the inland and open seas, which adopts a novel partially-balanced, hydraulically lifting ship lift; it can meet such requirements as fast and sharp water level change in open sea, large draft of a yacht, and launching of a ship reception chamber; its balancing weight system can effectively reduce the load of the primary lifting cylinder, and optimize the force distribution of the ship reception chamber. The paper provides an introduction to main equipment, basic principles, main features and system composition of a ship lift. The unique power system and balancing system of the completed ship lift has offered some experience for the construction of the tourism-type ship lifts with a lower lifting height.

Hielke is a Bayesian, balancing field robot

NARCIS (Netherlands)

Evert, van F.K.; Lamaker, E.J.J.; Polder, G.; Jong, de A.; Heijden, van der G.W.A.M.; Groendijk, E.J.K.; Lotz, L.A.P.; Zalm, van der A.J.A.

2008-01-01

Driven by the success of the previous events in Wageningen in 2003, 2004 and 2005 and the Field Robot Event hosted by Hohenheim University in Stuttgart, Germany in 2006, Wageningen University organized the 5th Field Robot Event on June 14-16, 2007. This event was accompanied by a workshop and a fair

The Automated Assessment of Postural Stability: Balance Detection Algorithm.

Science.gov (United States)

Napoli, Alessandro; Glass, Stephen M; Tucker, Carole; Obeid, Iyad

2017-12-01

Impaired balance is a common indicator of mild traumatic brain injury, concussion and musculoskeletal injury. Given the clinical relevance of such injuries, especially in military settings, it is paramount to develop more accurate and reliable on-field evaluation tools. This work presents the design and implementation of the automated assessment of postural stability (AAPS) system, for on-field evaluations following concussion. The AAPS is a computer system, based on inexpensive off-the-shelf components and custom software, that aims to automatically and reliably evaluate balance deficits, by replicating a known on-field clinical test, namely, the Balance Error Scoring System (BESS). The AAPS main innovation is its balance error detection algorithm that has been designed to acquire data from a Microsoft Kinect ® sensor and convert them into clinically-relevant BESS scores, using the same detection criteria defined by the original BESS test. In order to assess the AAPS balance evaluation capability, a total of 15 healthy subjects (7 male, 8 female) were required to perform the BESS test, while simultaneously being tracked by a Kinect 2.0 sensor and a professional-grade motion capture system (Qualisys AB, Gothenburg, Sweden). High definition videos with BESS trials were scored off-line by three experienced observers for reference scores. AAPS performance was assessed by comparing the AAPS automated scores to those derived by three experienced observers. Our results show that the AAPS error detection algorithm presented here can accurately and precisely detect balance deficits with performance levels that are comparable to those of experienced medical personnel. Specifically, agreement levels between the AAPS algorithm and the human average BESS scores ranging between 87.9% (single-leg on foam) and 99.8% (double-leg on firm ground) were detected. Moreover, statistically significant differences in balance scores were not detected by an ANOVA test with alpha equal to 0

The Effects of Balanced Low Calorie Diet on Weight Loss and Insulin Resistance among Obese Women in Ardabil City

Directory of Open Access Journals (Sweden)

Fatemeh Ghannadiasl

2016-07-01

Full Text Available Background & Objectives: Obesity is associated with metabolic abnormalities such as insulin resistance. Weight loss is always recommended for meaningful reduction in these abnormalities. Therefore, we examined the effects of balanced low calorie diet on weight loss, fasting insulin and insulin resistance in obese women attending the nutrition clinic. Methods: In this clinical trial, forty five volunteer apparently healthy obese women (body mass index: 33.28 ± 2.90 kg/m2 and age: 28.40 ± 7.98 years were recruited from the nutrition clinic in their first visit. The participants were received a balanced low calorie diet over 6 months after anthropometry measurement and blood sampling for determination of fasting insulin and insulin resistance level. Balanced low calorie diet was an individualized diet with an energy deficit of 500 calories of daily energy intake that was calculated from 3-day food records for every person. At 6 months after intervention, continuous and dichotomous variables were assessed using paired t-test and McNemar test, respectively. Results: The mean recommended energy intake was 2241.78 ± 219.02(kcal. After 6 months, there were significant reductions in body weight (p=0.003, body mass index (p=0.005, waist and hip circumferences (p<0.001 and p<0.001, respectively. There was also significant improvement in fasting insulin level (13.47 ± 6.55 vs. 11.95 ± 4.17 µU/ml, p=0.01. Whereas, insulin resistance had not significant reduction (p=0.1. Conclusion: In obese women attending the nutrition clinic, the balanced low calorie diet resulted in weight loss and improvement in fasting insulin. These positive changes can help to decrease the risk factor profile in obese individuals.

Adaptive Load Balancing of Parallel Applications with Multi-Agent Reinforcement Learning on Heterogeneous Systems

Directory of Open Access Journals (Sweden)

Johan Parent

2004-01-01

Full Text Available We report on the improvements that can be achieved by applying machine learning techniques, in particular reinforcement learning, for the dynamic load balancing of parallel applications. The applications being considered in this paper are coarse grain data intensive applications. Such applications put high pressure on the interconnect of the hardware. Synchronization and load balancing in complex, heterogeneous networks need fast, flexible, adaptive load balancing algorithms. Viewing a parallel application as a one-state coordination game in the framework of multi-agent reinforcement learning, and by using a recently introduced multi-agent exploration technique, we are able to improve upon the classic job farming approach. The improvements are achieved with limited computation and communication overhead.

Status of National Programmes on Fast Breeder Reactors. International Working Group on Fast Reactors Twenty-First Annual Meeting, Seattle, USA, 9-12 May 1988

International Nuclear Information System (INIS)

1988-11-01

The following papers on the status of national programmes on fast breeder reactors are presented in this report: Fast breeder reactor development in France during 1987; Status of fast breeder reactor development in the Federal Republic of Germany, Belgium and the Netherlands; A review of the Indian fast reactor programme; A review of the Italian fast reactor programme; A review of the fast reactor programme in Japan; Status of fast reactor activities in the USSR; A review of the United Kingdom fast reactor programme; Status of liquid metal reactor development in the United States of America; Review of activities of the Commission of European Communities relating to fast reactors in 1987; European co-operation in the field of fast reactor research and development — 1987 progress report; A review of fast reactor activities in Switzerland

Fast magnetic resonance fingerprinting for dynamic contrast-enhanced studies in mice.

Science.gov (United States)

Gu, Yuning; Wang, Charlie Y; Anderson, Christian E; Liu, Yuchi; Hu, He; Johansen, Mette L; Ma, Dan; Jiang, Yun; Ramos-Estebanez, Ciro; Brady-Kalnay, Susann; Griswold, Mark A; Flask, Chris A; Yu, Xin

2018-05-09

The goal of this study was to develop a fast MR fingerprinting (MRF) method for simultaneous T 1 and T 2 mapping in DCE-MRI studies in mice. The MRF sequences based on balanced SSFP and fast imaging with steady-state precession were implemented and evaluated on a 7T preclinical scanner. The readout used a zeroth-moment-compensated variable-density spiral trajectory that fully sampled the entire k-space and the inner 10 × 10 k-space with 48 and 4 interleaves, respectively. In vitro and in vivo studies of mouse brain were performed to evaluate the accuracy of MRF measurements with both fully sampled and undersampled data. The application of MRF to dynamic T 1 and T 2 mapping in DCE-MRI studies were demonstrated in a mouse model of heterotopic glioblastoma using gadolinium-based and dysprosium-based contrast agents. The T 1 and T 2 measurements in phantom showed strong agreement between the MRF and the conventional methods. The MRF with spiral encoding allowed up to 8-fold undersampling without loss of measurement accuracy. This enabled simultaneous T 1 and T 2 mapping with 2-minute temporal resolution in DCE-MRI studies. Magnetic resonance fingerprinting provides the opportunity for dynamic quantification of contrast agent distribution in preclinical tumor models on high-field MRI scanners. © 2018 International Society for Magnetic Resonance in Medicine.

Multishot echo-planar MREIT for fast imaging of conductivity, current density, and electric field distributions.

Science.gov (United States)

Chauhan, Munish; Vidya Shankar, Rohini; Ashok Kumar, Neeta; Kodibagkar, Vikram D; Sadleir, Rosalind

2018-01-01

Magnetic resonance electrical impedance tomography (MREIT) sequences typically use conventional spin or gradient echo-based acquisition methods for reconstruction of conductivity and current density maps. Use of MREIT in functional and electroporation studies requires higher temporal resolution and faster sequences. Here, single and multishot echo planar imaging (EPI) based MREIT sequences were evaluated to see whether high-quality MREIT phase data could be obtained for rapid reconstruction of current density, conductivity, and electric fields. A gel phantom with an insulating inclusion was used as a test object. Ghost artifact, geometric distortion, and MREIT correction algorithms were applied to the data. The EPI-MREIT-derived phase-projected current density and conductivity images were compared with simulations and spin-echo images as a function of EPI shot number. Good agreement among measures in simulated, spin echo, and EPI data was achieved. Current density errors were stable and below 9% as the shot number decreased from 64 to 2, but increased for single-shot images. Conductivity reconstruction relative contrast ratios were stable as the shot number decreased. The derived electric fields also agreed with the simulated data. The EPI methods can be combined successfully with MREIT reconstruction algorithms to achieve fast imaging of current density, conductivity, and electric field. Magn Reson Med 79:71-82, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Method for measuring and evaluation dose equivalent rate from fast neutrons in mixed gamma-neutron fields around particles accelerators

International Nuclear Information System (INIS)

Cruceru, I.; Sandu, M.; Cruceru, M.

1994-01-01

A method for measuring and evaluation of doses and dose equivalent rate in mixed gamma- neutron fields is discussed in this paper. The method is basedon a double detector system consist of an ionization chamber with components made from a plastic scintillator, coupled to on photomultiplier. Generally the radiation fields around accelerators are complex, often consisting of many different ionizing radiations extending over a broad range of energies. This method solve two major difficulties: determination of response functions of radiation detectors; interpretation of measurement and determination of accuracy. The discrimination gamma-fast neutrons is assured directly without a pulse shape discrimination circuit. The method is applied to mixed fields in which particle energies are situated in the energy range under 20 MeV and an izotropic emision (Φ=10 4 -10 11 n.s -1 ). The dose equivalent rates explored is 0.01mSV--0.1SV

{sup 20}F power measurement for generation IV sodium fast reactors

Energy Technology Data Exchange (ETDEWEB)

Coulon, R.; Normand, S.; Michel, M.; Barbot, L.; Domenech, T.; Boudergui, K.; Bourbotte, J.M.; Kondrasovs, V.; Frelin-Labalme, A.M.; Hamrita, H. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); BAN, G. [ENSICAEN, 6 Boulevard Marechal Juin, F-14050 Caen Cedex 4 (France); Barat, E.; Dautremer, T.; Montagu, T.; Carrel, F. [CEA, LIST, Laboratoire Modelisation Simulation et Systemes, F-91191 Gif-sur-Yvette (France); Brau, H.P. [ICSM, Centre de Marcoule, BP 17171 F-30207 Bagnols sur Ceze (France); Dumarcher, V. [AREVA NP, SET, F-84500 Bollene (France); Portier, J.L. [Centrale PHENIX, Centre de Marcoule, Groupe Essais Statistiques, F-30207 Bagnols sur Ceze (France); Jousset, P. [CEA, LIST, Laboratoire Capteurs Diamant, F-91191 Gif-sur-Yvette (France); Saurel, N. [CEA, DAM, Laboratoire Mesure de Dechets et Expertise, F-21120 Is-sur-Tille, France.F-84500 Bollene (France)

2010-07-01

The Phenix nuclear power plant has been a French Sodium Fast Reactor (SFR) prototype producing electrical power between 1973 and 2010. The power was monitored using ex-core neutron measurements. This kind of measurement instantly estimates the power but needs to be often calibrated with the heat balance thermodynamic measurement. Large safety and security margins have then been set not to derive above the nominal operating point. It is important for future SFR to reduce this margin and working closer to the nominal operating point. This work deals with the use of delayed gamma to measure the power. The main activation product contained in the primary sodium coolant is the {sup 24}Na which is not convenient for neutron flux measurement due to its long decay period. The experimental study done at the Phenix reactor shows that the use of {sup 20}F as power tagging agent gives a fast and accurate power measurement closed to the thermal balance measurement thanks to its high energy photon emission (1.634 MeV) and its short decay period (11 s). (authors)

Annual Fasting; the Early Calories Restriction for Cancer Prevention

Directory of Open Access Journals (Sweden)

Solat Eslami

2012-12-01

Full Text Available Essentially, people’s diet and nutritional status has been changed substantially worldwide and several lines of evidence suggest that these changes are to the detriment of their health. Additionally, it has been well documented that unhealthy diet especially the fast foods, untraditional foods or bad-eating-habits influence the human gut microbiome. The gut microbiota shapes immune responses during human life and affects his/her metabolomic profiles. Furthermore, many studies highlight the molecular pathways that mediate host and symbiont interactions that regulate proper immune function and prevention of cancer in the body. Intriguingly, if cancer forms in a human body due to the weakness of immune system in detriment of microbiome, the removal of cancer stem cells can be carried out through early Calories Restriction with Annual Fasting (AF before tumor development or progress. Besides, fasting can b balance the gut microbiome for enhancement of immune system against cancer formation.

Opportunities and Challenges in Enhancing Value of Annual Glacier Mass Balance Monitoring Examples from Western North America

Science.gov (United States)

Pelto, M. S.

2017-12-01

Alpine glacier mass balance is the most accurate indicator of glacier response to climate and with retreat of alpine glaciers is one of the clearest signals of global climate change. Completion of long term, representative and homogenous mass balance field measurement of mass balance, compiled by WGMS, is a key climate data record. To ensure a monitoring program remains vital and funded local collaboration and connecting the research to local societal impacts is crucial. Working with local partners in collecting and providing the right data is critical whether their interest is in hydropower, irrigation, municipal supply, hazard reduction and/or aquatic ecosystems. The expansion of remote sensing and modeling capability provides both a challenge to continued relevance and an opportunity for field mass balance programs to expand relevance. In modelling studies of both glacier mass balance and glacier runoff transient balance data has equivalent value with annual balance data, for both calibration runs and as an input variable. This increases the utility of mid-season field observations. Remote sensing provides repeat imagery that often identifies the AAR and transient snowline of a glacier. For runoff assessment understanding the specific percent of glacier surface area that is glacier ice, older firn, and retained snowpack from the previous winter at frequent intervals during the melt season is vital since each region has a different melt factor. A denser field observation network combined with this imagery can provide additional point balance values of ablation that complement the mass balance record. Periodic measurement of mass balance at a denser network using GPR, LIDAR, TLS or probing is required to better understand long term point balance locations and is important at end of the melt season not just beginning, and has value mid-season for modelling. Applications of each of utility of field mass balance observations will be illustrated.

[BALANCED SCORECARD AS A MANAGEMENT TOOL IN CLINICAL NUTRITION].

Science.gov (United States)

Gutiérrez López, Cristina; Mauriz, Jose L; Culebras, Jesús M

2015-07-01

Nowadays, balanced scorecards have updated traditional management systems in the business sector. In this way, Kaplan and Norton propose performance measurement through several perspectives with a logical sequence: internal processes and learning impact client services, so that financial performance is affected. The aim of the present paper is to analyze the main characteristics of balanced scorecard when it is applied to non-for-profit companies and, specifically to the health sector in the clinical nutrition field. This model improves the economic vision of management with clinical indicators that represent healthcare professional's perspective. The balanced scorecard would allow a proper monitoring and tracking system for the main healthcare indicators. This contributes to a better control in comparison with standards that are associated with adequate quality assistance. Owing to the role of management accounting and cost calculations, the definition of healthcare professionals as clients or users, and clinical results relevance, it is necessary to adapt the balanced scorecard to the specific characteristics of the clinical field, redefining both perspectives and indicators. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Effects of Fast-Ion Injection on a Magnetized Sheath near a Floating Wall

International Nuclear Information System (INIS)

Li Jiajia; Hu Zhanghu; Song Yuanhong; Wang Younian

2013-01-01

A fully kinetic particle-in-cell/Monte Carlo model is employed to self-consistently study the effects of fast-ion injection on sheath potential and electric field profile in collisional magnetized plasma with a floating absorbing wall. The influences of the fast-ion injection velocity and density, the magnetic field and angle θ 0 formed by the magnetic field and the x-axis on the sheath potential and electric field are discussed in detail. Numerical results show that increasing fast-ion injection density or decreasing injection velocity can enhance the potential drop and electric field in the sheath. Also, increasing the magnetic field strength can weaken the loss of charged particles to the wall and thus decrease the potential and electric field in the sheath. The time evolution of ion flux and velocity distribution on the wall is found to be significantly affected by the magnetic field.

Nutrient-sensing nuclear receptors PPARα and FXR control liver energy balance.

Science.gov (United States)

Preidis, Geoffrey A; Kim, Kang Ho; Moore, David D

2017-04-03

The nuclear receptors PPARα (encoded by NR1C1) and farnesoid X receptor (FXR, encoded by NR1H4) are activated in the liver in the fasted and fed state, respectively. PPARα activation induces fatty acid oxidation, while FXR controls bile acid homeostasis, but both nuclear receptors also regulate numerous other metabolic pathways relevant to liver energy balance. Here we review evidence that they function coordinately to control key nutrient pathways, including fatty acid oxidation and gluconeogenesis in the fasted state and lipogenesis and glycolysis in the fed state. We have also recently reported that these receptors have mutually antagonistic impacts on autophagy, which is induced by PPARα but suppressed by FXR. Secretion of multiple blood proteins is a major drain on liver energy and nutrient resources, and we present preliminary evidence that the liver secretome may be directly suppressed by PPARα, but induced by FXR. Finally, previous studies demonstrated a striking deficiency in bile acid levels in malnourished mice that is consistent with results in malnourished children. We present evidence that hepatic targets of PPARα and FXR are dysregulated in chronic undernutrition. We conclude that PPARα and FXR function coordinately to integrate liver energy balance.

A new Recoil Proton Telescope for energy and fluence measurement of fast neutron fields

Energy Technology Data Exchange (ETDEWEB)

Lebreton, Lena; Bachaalany, Mario [IRSN / LMDN (Institut de Radioprotection et de Surete nucleaire / Laboratoire de Metrologie et de dosimetrie des neutrons), Cadarache Bat.159, 13115 Saint Paul-lez-Durance, (France); Husson, Daniel; Higueret, Stephane [IPHC / RaMsEs (Institut Pluridisciplinaire Hubert Curien / Radioprotection et Mesures Environnementales), 23 rue du loess - BP28, 67037 Strasbourg cedex 2, (France)

2015-07-01

The spectrometer ATHENA (Accurate Telescope for High Energy Neutron metrology Applications), is being developed at the IRSN / LMDN (Institut de Radioprotection et de Surete nucleaire / Laboratoire de Metrologie et de dosimetrie des neutrons) and aims at characterizing energy and fluence of fast neutron fields. The detector is a Recoil Proton Telescope and measures neutron fields in the range of 5 to 20 MeV. This telescope is intended to become a primary standard for both energy and fluence measurements. The neutron detection is achieved by a polyethylene radiator for n-p conversion, three 50{sub m} thick silicon sensors that use CMOS technology for the proton tracking and a 3 mm thick silicon diode to measure the residual proton energy. This first prototype used CMOS sensors called MIMOSTAR, initially developed for heavy ion physics. The use of CMOS sensors and silicon diode increases the intrinsic efficiency of the detector by a factor of ten compared with conventional designs. The first prototype has already been done and was a successful study giving the results it offered in terms of energy and fluence measurements. For mono energetic beams going from 5 to 19 MeV, the telescope offered an energy resolution between 5 and 11% and fluence difference going from 5 to 7% compared to other home standards. A second and final prototype of the detector is being designed. It will hold upgraded CMOS sensors called FastPixN. These CMOS sensors are supposed to run 400 times faster than the older version and therefore give the telescope the ability to support neutron flux in the order of 107 to 108cm{sup 2}:s{sup 1}. The first prototypes results showed that a 50 m pixel size is enough for a precise scattering angle reconstruction. Simulations using MCNPX and GEANT4 are already in place for further improvements. A DeltaE diode will replace the third CMOS sensor and will be installed right before the silicon diode for a better recoil proton selection. The final prototype with

[Brief disserting on the balance of internal environment in burn disease].

Science.gov (United States)

Han, C M; Wang, X G

2017-08-20

The essential internal environment in human being involves water, electrolyte, and acid-base balance, which is the basis of balance and stability of internal environment in other systems. For burn patients, the balance of internal environment, referring to metabolism, nutrition, inflammatory response, and immunoreaction, is one of the most important aspects in burn disease. This paper aims to briefly elaborate the balance of internal environment after burn, with the purpose to promote the basic and clinical research in this field.

An Elastic Charging Service Fee-Based Load Guiding Strategy for Fast Charging Stations

Directory of Open Access Journals (Sweden)

Shu Su

2017-05-01

Full Text Available Compared with the traditional slow charging loads, random integration of large scale fast charging loads will exert more serious impacts on the security of power network operation. Besides, to maximize social benefits, effective scheduling strategies guiding fast charging behaviors should be formulated rather than simply increasing infrastructure construction investments on the power grid. This paper first analyzes the charging users’ various responses to an elastic charging service fee, and introduces the index of charging balance degree to a target region by considering the influence of fast charging loads on the power grid. Then, a multi-objective optimization model of the fast charging service fee is constructed, whose service fee can be further optimized by employing a fuzzy programming method. Therefore, both users’ satisfaction degree and the equilibrium of charging loads can be maintained simultaneously by reasonably guiding electric vehicles (EVs to different fast charging stations. The simulation results demonstrate the effectiveness of the proposed dynamic charging service pricing and the corresponding fast charging load guidance strategy.

Pre evaluation for heat balance of prototype sodium cooled fast reactor

International Nuclear Information System (INIS)

Han, Ji Woong; Kim, De Hee; Yoon, Jung; Kim, Eui Kwang; Lee, Tae Ho

2012-01-01

Under the long term advanced SFR R and D plan, the design of prototype reactor has been carried out toward the construction of the prototype SFR plant by 2028. The R and D efforts in fluid system design will be focused on developing a prototype design of primary heat transport system(PHTS), intermediate heat transport system (IHTS), decay heat removal system(DHRS), steam generation system(SGS), and related auxiliary system design for a prototype reactor as shown in Fig. 1. In order to make progress system design, top tier requirements for prototype reactor related to design parameters of NSSS and BOP should be decided at first. The top tier requirement includes general design basis, capacity and characteristics of reactor, various requirements related to safety, performance, securities, economics, site, and etc.. Extensive discussion has been done within Korea Atomic Energy Research Institute(KAERI) for the decision of top tier requirements of the prototype reactor. The core outlet temperature, which should be described as top tier requirements, is one of the critical parameter for system design. The higher core exit temperature could contribute to increase the plant efficiency. However, it could also contribute to decrease the design margin for structure and safety. Therefore various operating strategies based on different core outlet temperatures should be examined and evaluated. For the prototype reactor two core outlet temperatures are taken into accounted. The lower temperature is for the operation condition and the higher temperature is for the system design and licensing process of the prototype reactor. In order to evaluate the operability of prototype reactor designed based on higher temperature, the heat balance calculations have been performed at different core outlet temperature conditions. The electrical power of prototype reactor was assumed to be 100MWe and reference operating conditions were decided based on existing available data. The

Effect of ramadan fasting on body composition and physical performance in female athletes.

Science.gov (United States)

Memari, Amir-Hossein; Kordi, Ramin; Panahi, Nekoo; Nikookar, Laya R; Abdollahi, Mohammad; Akbarnejad, Ali

2011-09-01

The aim of this study was to determine the effect of Ramadan fasting on body composition, calorie intake and physical performance in young female athletes undertaking training sessions during Ramadan. Twelve voluntary female athletes (15-27 years old) were assigned to the research. A prospective study was conducted to investigate the athletes on four different occasions: one week before Ramadan (T1), the second (T2) and fourth (T3) weeks of Ramadan, and two weeks after the end of Ramadan (T4). Food intake, body composition and physical performance (agility, balance and explosive leg power) were investigated on each occasion. Further, Physical performance was assessed by agility, vertical jump and balance tests. There was a significant main effect for time for body composition indices. A significant decrease was observed in weight (P=0.01) and body mass index (BMI) (P=0.01) in T2 compared with T1, further decrease in weight (Peffect for time for agility performance (P=0.03), but no significant main effect for time was observed for vertical jumping (P=0.1) and balance performance (P=0.3). This study has found that Ramadan fasting could affect the body composition, but not physical performance in female athletes during Ramadan.

A permanent magnet system for Kibble balances

Science.gov (United States)

Li, Shisong; Bielsa, Franck; Stock, Michael; Kiss, Adrien; Fang, Hao

2017-10-01

The magnet is one of the fundamental elements in Kibble balances. The Kibble balance group at the Bureau International des Poids et Mesures (BIPM) proposed a permanent magnet with a radial field, which has been widely employed in other Kibble balance experiments. In this paper, we discuss a different method of operation for the BIPM-type magnet, i.e. only the lower half of the magnetic circuit is closed. The merit of such a magnet is its convenience for opening the air gap and adjusting the coil. A disadvantage is that it can yield a lower and sloped magnetic field profile with less shielding. In the approach described, high permeability yokes are used to flatten the magnetic profile, which has proven to be a novel and convenient approach for removing the nonuniformity of the magnetic profile due to magnet magnetization asymmetries. The performance of the half-closed BIPM magnet is evaluated using experimental measurements. The results show that the half-closed magnetic circuit retains most of the main features of the fully-closed magnet and is a good option for the early stages of Kibble balance operations. In addition, the profile change due to the coil current is predicted and experimentally verified with a bifilar coil. Related systematic effects are discussed for the Planck constant measurement.

Advances in fast-atom-bombardment mass spectroscopy

International Nuclear Information System (INIS)

Hemling, M.E.

1986-01-01

A comparison of fast atom bombardment and field desorption mass spectrometry was made to determine relative sensitivity and applicability. A series of glycosphingolipids and a series of protected oligonucleotides of known structure were analyzed to ascertain the potential utility of fast atom bombardment mass spectrometry in the structural elucidation of novel compounds in these classes. Negative ion mass markers were also developed. Fast atom bombardment was found to be one-to-two orders of magnitude more sensitive than field desorption based on the analysis of a limited number of compounds from several classes. Superior sensitivity was not universal and field desorption was clearly better in certain cases. In the negative ion mode in particular, fast atom bombardment was found to be a useful tool for the determination of the primary structure of glycosphingolipids and oligonucleotides. Carbohydrate sequence and branching information, and a fatty acid and lipid base composition were readily obtained from the mass spectra of glycosphingolipids while bidirectional nucleotide sequence, nucleotide base, and protecting group assignments were obtained for oligonucleotides. Based on this knowledge, a tentative structure of a human peripheral nervous system glycosphingolipid implicated in certain cases of disorders such as amyotrophic lateral sclerosis, Lou Gehrig's Disease, was proposed. Suitable negative ion mass markers were found in dispersions of poly(ethylene) and poly(propylene)glycols in a triethylenetetramine matrix, a matrix which also proved useful in the analysis of glycosphingolipids. These polyglycol dispersions provided ions for calibration to 2300 daltons

Balanced Reed-Solomon codes for all parameters

KAUST Repository

Halbawi, Wael; Liu, Zihan; Hassibi, Babak

2016-01-01

We construct balanced and sparsest generator matrices for cyclic Reed-Solomon codes with any length n and dimension k. By sparsest, we mean that each row has the least possible number of nonzeros, while balanced means that the number of nonzeros in any two columns differs by at most one. Codes allowing such encoding schemes are useful in distributed settings where computational load-balancing is critical. The problem was first studied by Dau et al. who showed, using probabilistic arguments, that there always exists an MDS code over a sufficiently large field such that its generator matrix is both sparsest and balanced. Motivated by the need for an explicit construction with efficient decoding, the authors of the current paper showed that the generator matrix of a cyclic Reed-Solomon code of length n and dimension k can always be transformed to one that is both sparsest and balanced, when n and k are such that k/n (n-k+1) is an integer. In this paper, we lift this condition and construct balanced and sparsest generator matrices for cyclic Reed-Solomon codes for any set of parameters.

Balanced Reed-Solomon codes for all parameters

KAUST Repository

Halbawi, Wael

2016-10-27

We construct balanced and sparsest generator matrices for cyclic Reed-Solomon codes with any length n and dimension k. By sparsest, we mean that each row has the least possible number of nonzeros, while balanced means that the number of nonzeros in any two columns differs by at most one. Codes allowing such encoding schemes are useful in distributed settings where computational load-balancing is critical. The problem was first studied by Dau et al. who showed, using probabilistic arguments, that there always exists an MDS code over a sufficiently large field such that its generator matrix is both sparsest and balanced. Motivated by the need for an explicit construction with efficient decoding, the authors of the current paper showed that the generator matrix of a cyclic Reed-Solomon code of length n and dimension k can always be transformed to one that is both sparsest and balanced, when n and k are such that k/n (n-k+1) is an integer. In this paper, we lift this condition and construct balanced and sparsest generator matrices for cyclic Reed-Solomon codes for any set of parameters.

Balance Performance Is Task Specific in Older Adults

Directory of Open Access Journals (Sweden)

Ayelet Dunsky

2017-01-01

Full Text Available Balance ability among the elderly is a key component in the activities of daily living and is divided into two types: static and dynamic. For clinicians who wish to assess the risk of falling among their elderly patients, it is unclear if more than one type of balance test can be used to measure their balance impairment. In this study, we examined the association between static balance measures and two dynamic balance field tests. One hundred and twelve community-dwelling older adults (mean age 74.6 participated in the study. They underwent the Tetrax static postural assessment and then performed the Timed Up and Go (TUG and the Functional Reach (FR Test as dynamic balance tests. In general, low-moderate correlations were found between the two types of balance tests. For women, age and static balance parameters explained 28.1–40.4% of the variance of TUG scores and 14.6–24% of the variance of FR scores. For men, age and static balance parameters explained 9.5–31.2% of the variance of TUG scores and 23.9–41.7% of the variance of FR scores. Based on our findings, it is suggested that a combination of both static and dynamic tests be used for assessing postural balance ability.

Balancing your personal and professional lives: help for busy medical practice employees.

Science.gov (United States)

Hills, Laura Sachs

2008-01-01

It is extremely difficult for most people to balance work and home life. This is especially true of employees who work in fast-paced medical practices where they are on the go all day. Each medical practice employee must find his or her own way to balance work and life, but fortunately, the process can usually be boiled down to some basics. This article outlines a strategy for establishing the top five priorities in the medical practice employee's life. It suggests that medical practice personnel can develop and use a personal mission statement as a life guide. This article also suggests specific strategies medical practice employees can use to protect and make the best use of their private time. It provides examples of how medical practice personnel have changed their lives by dropping unnecessary activities from their daily schedules. Finally, this article offers guidance about getting children to help working parents balance their work and private lives, 10 additional tips for work/life balance, a work/life balance self-assessment quiz, and a template the medical practice employee can use to create a customized personal mission statement.

Fast ignition realization experiment with high-contrast kilo-joule peta-watt LFEX laser and strong external magnetic field

Science.gov (United States)

Fujioka, Shinsuke; Arikawa, Yasunobu; Kojima, Sadaoki; Johzaki, Tomoyuki; Nagatomo, Hideo; Sawada, Hiroshi; Lee, Seung Ho; Shiroto, Takashi; Ohnishi, Naofumi; Morace, Alessio; Vaisseau, Xavier; Sakata, Shohei; Abe, Yuki; Matsuo, Kazuki; Farley Law, King Fai; Tosaki, Shota; Yogo, Akifumi; Shigemori, Keisuke; Hironaka, Yoichiro; Zhang, Zhe; Sunahara, Atsushi; Ozaki, Tetsuo; Sakagami, Hitoshi; Mima, Kunioki; Fujimoto, Yasushi; Yamanoi, Kohei; Norimatsu, Takayoshi; Tokita, Shigeki; Nakata, Yoshiki; Kawanaka, Junji; Jitsuno, Takahisa; Miyanaga, Noriaki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Kondo, Kotaro; Bailly-Grandvaux, Mathieu; Bellei, Claudio; Santos, João Jorge; Azechi, Hiroshi

2016-05-01

A petawatt laser for fast ignition experiments (LFEX) laser system [N. Miyanaga et al., J. Phys. IV France 133, 81 (2006)], which is currently capable of delivering 2 kJ in a 1.5 ps pulse using 4 laser beams, has been constructed beside the GEKKO-XII laser facility for demonstrating efficient fast heating of a dense plasma up to the ignition temperature under the auspices of the Fast Ignition Realization EXperiment (FIREX) project [H. Azechi et al., Nucl. Fusion 49, 104024 (2009)]. In the FIREX experiment, a cone is attached to a spherical target containing a fuel to prevent a corona plasma from entering the path of the intense heating LFEX laser beams. The LFEX laser beams are focused at the tip of the cone to generate a relativistic electron beam (REB), which heats a dense fuel core generated by compression of a spherical deuterized plastic target induced by the GEKKO-XII laser beams. Recent studies indicate that the current heating efficiency is only 0.4%, and three requirements to achieve higher efficiency of the fast ignition (FI) scheme with the current GEKKO and LFEX systems have been identified: (i) reduction of the high energy tail of the REB; (ii) formation of a fuel core with high areal density using a limited number (twelve) of GEKKO-XII laser beams as well as a limited energy (4 kJ of 0.53-μm light in a 1.3 ns pulse); (iii) guiding and focusing of the REB to the fuel core. Laser-plasma interactions in a long-scale plasma generate electrons that are too energetic to efficiently heat the fuel core. Three actions were taken to meet the first requirement. First, the intensity contrast of the foot pulses to the main pulses of the LFEX was improved to >109. Second, a 5.5-mm-long cone was introduced to reduce pre-heating of the inner cone wall caused by illumination of the unconverted 1.053-μm light of implosion beam (GEKKO-XII). Third, the outside of the cone wall was coated with a 40-μm plastic layer to protect it from the pressure caused by imploding

Fast ignition realization experiment with high-contrast kilo-joule peta-watt LFEX laser and strong external magnetic field

Energy Technology Data Exchange (ETDEWEB)

Fujioka, Shinsuke, E-mail: sfujioka@ile.osaka-u.ac.jp; Arikawa, Yasunobu; Kojima, Sadaoki; Nagatomo, Hideo; Lee, Seung Ho; Morace, Alessio; Vaisseau, Xavier; Sakata, Shohei; Abe, Yuki; Matsuo, Kazuki; Farley Law, King Fai; Tosaki, Shota; Yogo, Akifumi; Shigemori, Keisuke; Hironaka, Yoichiro; Fujimoto, Yasushi; Yamanoi, Kohei; Norimatsu, Takayoshi; Tokita, Shigeki; Nakata, Yoshiki [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871 Japan (Japan); and others

2016-05-15

A petawatt laser for fast ignition experiments (LFEX) laser system [N. Miyanaga et al., J. Phys. IV France 133, 81 (2006)], which is currently capable of delivering 2 kJ in a 1.5 ps pulse using 4 laser beams, has been constructed beside the GEKKO-XII laser facility for demonstrating efficient fast heating of a dense plasma up to the ignition temperature under the auspices of the Fast Ignition Realization EXperiment (FIREX) project [H. Azechi et al., Nucl. Fusion 49, 104024 (2009)]. In the FIREX experiment, a cone is attached to a spherical target containing a fuel to prevent a corona plasma from entering the path of the intense heating LFEX laser beams. The LFEX laser beams are focused at the tip of the cone to generate a relativistic electron beam (REB), which heats a dense fuel core generated by compression of a spherical deuterized plastic target induced by the GEKKO-XII laser beams. Recent studies indicate that the current heating efficiency is only 0.4%, and three requirements to achieve higher efficiency of the fast ignition (FI) scheme with the current GEKKO and LFEX systems have been identified: (i) reduction of the high energy tail of the REB; (ii) formation of a fuel core with high areal density using a limited number (twelve) of GEKKO-XII laser beams as well as a limited energy (4 kJ of 0.53-μm light in a 1.3 ns pulse); (iii) guiding and focusing of the REB to the fuel core. Laser–plasma interactions in a long-scale plasma generate electrons that are too energetic to efficiently heat the fuel core. Three actions were taken to meet the first requirement. First, the intensity contrast of the foot pulses to the main pulses of the LFEX was improved to >10{sup 9}. Second, a 5.5-mm-long cone was introduced to reduce pre-heating of the inner cone wall caused by illumination of the unconverted 1.053-μm light of implosion beam (GEKKO-XII). Third, the outside of the cone wall was coated with a 40-μm plastic layer to protect it from the pressure caused

Carbon dioxide emissions and energy balance closure before, during, and after biomass burning in mid-South rice fields

Science.gov (United States)

Fong, B.; Adviento-Borbe, A.; Reba, M. L.; Runkle, B.; Suvocarev, K.

2017-12-01

Biomass burning or field burning is a crop management practice that removes rice straw, reduces tillage, controls pests and releases nutrients for the next cropping season. Current field burning emissions are not included in agricultural field annual emissions largely because of the lack of studies, especially on the field scale. Field burning measurements are important for greenhouse gas emission inventories and quantifying the annual carbon footprint of rice. Paired eddy covariance systems were used to measure energy balance, CO2 fluxes, and H2O fluxes in mid-South US rice fields (total area of 25 ha) before, during and after biomass burning for 20 days after harvest. During the biomass burning, air temperatures increased 29°C, while ambient CO2 concentration increased from 402 to 16,567 ppm and H2O concentrations increased from 18.73 to 25.62 ppt. For the burning period, 67-86 kg CO2 ha-1 period-1 was emitted calculated by integrating fluxes over the biomass burning event. However, the estimated emission using aboveground biomass and combustion factors was calculated as 11,733 kg CO2 ha-1 period-1. Part of the difference could be attributed to sensor sensitivity decreasing 80% during burning for two minutes due to smoke. Net ecosystem exchange (NEE) increased by a factor of two, 1.14 before burning to 2.44 μmol m-2 s-1 possibly due to greater reduction of plant material and photosynthesis following burning. This study highlights the contribution of rice straw burning to total CO2 emissions from rice production.

BALANCE

Science.gov (United States)

Carmichael, H.

1953-01-01

A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

Bath Breakfast Project (BBP - Examining the role of extended daily fasting in human energy balance and associated health outcomes: Study protocol for a randomised controlled trial [ISRCTN31521726

Directory of Open Access Journals (Sweden)

Jeans Matthew

2011-07-01

Full Text Available Abstract Background Current guidance regarding the role of daily breakfast in human health is largely grounded in cross-sectional observations. However, the causal nature of these relationships has not been fully explored and what limited information is emerging from controlled laboratory-based experiments appears inconsistent with much existing data. Further progress in our understanding therefore requires a direct examination of how daily breakfast impacts human health under free-living conditions. Methods/Design The Bath Breakfast Project (BBP is a randomised controlled trial comparing the effects of daily breakfast consumption relative to extended fasting on energy balance and human health. Approximately 70 men and women will undergo extensive laboratory-based assessments of their acute metabolic responses under fasted and post-prandial conditions, to include: resting metabolic rate, substrate oxidation, dietary-induced thermogenesis and systemic concentrations of key metabolites/hormones. Physiological and psychological indices of appetite will also be monitored both over the first few hours of the day (i.e. whether fed or fasted and also following a standardised test lunch used to assess voluntary energy intake under controlled conditions. Baseline measurements of participants' anthropometric characteristics (e.g. DEXA will be recorded prior to intervention, along with an oral glucose tolerance test and acquisition of adipose tissue samples to determine expression of key genes and estimates of tissue-specific insulin action. Participants will then be randomly assigned either to a group prescribed an energy intake of ≥3000 kJ before 1100 each day or a group to extend their overnight fast by abstaining from ingestion of energy-providing nutrients until 1200 each day, with all laboratory-based measurements followed-up 6 weeks later. Free-living assessments of energy intake (via direct weighed food diaries and energy expenditure (via

Fast breeder reactor research

International Nuclear Information System (INIS)

1975-01-01

Full text: The meeting was attended by 15 participants from seven countries and two international organizations. The Eighth Annual Meeting of the International Working Group on Fast Reactors (IWGFR) was attended by representatives from France, Fed. Rep. Germany, Italy, Japan, United Kingdom, Union of Soviet Socialist Republics and the United States of America - countries that have made significant progress in developing the technology and physics of sodium cooled fast reactors and have extensive national programmes in this field - as well as by representatives of the Commission of the European Communities and the IAEA. The design of fast-reactor power plants is a more difficult task than developing facilities with thermal reactors. Different reactor kinetics and dynamics, a hard neutron spectrum, larger integral doses of fuel and structural material irradiation, higher core temperatures, the use of an essentially novel coolant, and, as a result of all these factors, the additional reliability and safety requirements that are imposed on the planning and operation of sodium cooled fast reactors - all these factors pose problems that can be solved comprehensively only by countries with a high level of scientific and technical development. The exchange of experience between these countries and their combined efforts in solving the fundamental problems that arise in planning, constructing and operating fast reactors are promoting technical progress and reducing the relative expenditure required for various studies on developing and introducing commercial fast reactors. For this reason, the meeting concentrated on reviewing and discussing national fast reactor programmes. The situation with regard to planning, constructing and operating fast experimental and demonstration reactors in the countries concerned, the experience accumulated in operating them, the difficulties arising during operation and ways of over-coming them, the search for optimal designs for the power

Short–Term Exposure to Electromagnetic Fields Generated by Mobile Phone Jammers Decreases the Fasting Blood Sugar in Adult Male Rats

Directory of Open Access Journals (Sweden)

Shekoohi Shooli F.

2016-03-01

Full Text Available Background: Substantial evidence indicates that exposure to electromagnetic fields (EMF above certain levels can affect human health through triggering some biological responses. According to WHO, short-term exposure to EMF at the levels present in the home/environment do not cause any apparent detrimental effects in healthy individuals. However, now, there is a debate on whether long-term exposure to low level EMF can evoke detrimental biological responses. Although based on the Communications Act of 1934, selling, advertising, using, or importing mobile jammers which block cell phone calls and text messages are illegal acts, in some countries these devices are being used for security purpose and for prevention of cheating during examinations. Methods: In this study 30 male Wistar rats were randomly divided into 3 groups of 10 each. The control group received no radiation. The sham exposure group was exposed to a switched-off jammer device. After fasting for 12 hours, the exposure group was exposed to EMFs at a distance of 50 cm from the jammer. Blood samples were collected from the tail vein after 24, 48 and72 hours and fasting blood sugar was measured by using a common blood glucose monitor (BIONIME GM110, Taiwan. The significance level was considered 5% and SPSS Ver. 21 was used for statistical analysis. The data were analyzed by ANOVA followed by Tukey’s test. Results: A statistically significant difference was observed between blood sugar level in the control and exposure groups after 24, 48 and 72 hours of continuous irradiation (p values were <0.001, <0.001 and 0.002, respectively. No significant difference was found between the level of fasting blood sugar in control and sham groups. Conclusion: Short-term exposure to electromagnetic field generated by mobile phone jammer can reduce blood sugar level in adult male rats. These findings, in contrast with our previous results, lead us to this conclusion that the use of these signal

Dissolution mechanism of crystalline cellulose in H3PO4 as assessed by high-field NMR spectroscopy and fast field cycling NMR relaxometry.

Science.gov (United States)

Conte, Pellegrino; Maccotta, Antonella; De Pasquale, Claudio; Bubici, Salvatore; Alonzo, Giuseppe

2009-10-14

Many processes have been proposed to produce glucose as a substrate for bacterial fermentation to obtain bioethanol. Among others, cellulose degradation appears as the most convenient way to achieve reliable amounts of glucose units. In fact, cellulose is the most widespread biopolymer, and it is considered also as a renewable resource. Due to extended intra- and interchain hydrogen bonds that provide a very efficient packing structure, however, cellulose is also a very stable polymer, the degradation of which is not easily achievable. In the past decade, researchers enhanced cellulose reactivity by increasing its solubility in many solvents, among which concentrated phosphoric acid (H(3)PO(4)) played the major role because of its low volatility and nontoxicity. In the present study, the solubilization mechanism of crystalline cellulose in H(3)PO(4) has been elucidated by using high- and low-field NMR spectroscopy. In particular, high-field NMR spectra showed formation of direct bonding between phosphoric acid and dissolved cellulose. On the other hand, molecular dynamics studies by low-field NMR with a fast field cycling (FFC) setup revealed two different H(3)PO(4) relaxing components. The first component, described by the fastest longitudinal relaxation rate (R(1)), was assigned to the H(3)PO(4) molecules bound to the biopolymer. Conversely, the second component, characterized by the slowest R(1), was attributed to the bulk solvent. The understanding of cellulose dissolution in H(3)PO(4) represents a very important issue because comprehension of chemical mechanisms is fundamental for process ameliorations to produce bioenergy from biomasses.

Energy Balance in an Electrostatic Accelerator

OpenAIRE

Zolotorev, Max S.; McDonald, Kirk T.

2000-01-01

The principle of an electrostatic accelerator is that when a charge e escapes from a conducting plane that supports a uniform electric field of strength E_0, then the charge gains energy e E_0 d as it moves distance d from the plane. Where does this energy come from? We that the mechanical energy gain of the electron is balanced by the decrease in the electrostatic field energy of the system.

A fast algorithm for forward-modeling of gravitational fields in spherical coordinates with 3D Gauss-Legendre quadrature

Science.gov (United States)

Zhao, G.; Liu, J.; Chen, B.; Guo, R.; Chen, L.

2017-12-01

Forward modeling of gravitational fields at large-scale requires to consider the curvature of the Earth and to evaluate the Newton's volume integral in spherical coordinates. To acquire fast and accurate gravitational effects for subsurface structures, subsurface mass distribution is usually discretized into small spherical prisms (called tesseroids). The gravity fields of tesseroids are generally calculated numerically. One of the commonly used numerical methods is the 3D Gauss-Legendre quadrature (GLQ). However, the traditional GLQ integration suffers from low computational efficiency and relatively poor accuracy when the observation surface is close to the source region. We developed a fast and high accuracy 3D GLQ integration based on the equivalence of kernel matrix, adaptive discretization and parallelization using OpenMP. The equivalence of kernel matrix strategy increases efficiency and reduces memory consumption by calculating and storing the same matrix elements in each kernel matrix just one time. In this method, the adaptive discretization strategy is used to improve the accuracy. The numerical investigations show that the executing time of the proposed method is reduced by two orders of magnitude compared with the traditional method that without these optimized strategies. High accuracy results can also be guaranteed no matter how close the computation points to the source region. In addition, the algorithm dramatically reduces the memory requirement by N times compared with the traditional method, where N is the number of discretization of the source region in the longitudinal direction. It makes the large-scale gravity forward modeling and inversion with a fine discretization possible.

Intermittent fasting results in tissue-specific changes in bioenergetics and redox state.

Science.gov (United States)

Chausse, Bruno; Vieira-Lara, Marcel A; Sanchez, Angélica B; Medeiros, Marisa H G; Kowaltowski, Alicia J

2015-01-01

Intermittent fasting (IF) is a dietary intervention often used as an alternative to caloric restriction (CR) and characterized by 24 hour cycles alternating ad libitum feeding and fasting. Although the consequences of CR are well studied, the effects of IF on redox status are not. Here, we address the effects of IF on redox state markers in different tissues in order to uncover how changes in feeding frequency alter redox balance in rats. IF rats displayed lower body mass due to decreased energy conversion efficiency. Livers in IF rats presented increased mitochondrial respiratory capacity and enhanced levels of protein carbonyls. Surprisingly, IF animals also presented an increase in oxidative damage in the brain that was not related to changes in mitochondrial bioenergetics. Conversely, IF promoted a substantial protection against oxidative damage in the heart. No difference in mitochondrial bioenergetics or redox homeostasis was observed in skeletal muscles of IF animals. Overall, IF affects redox balance in a tissue-specific manner, leading to redox imbalance in the liver and brain and protection against oxidative damage in the heart.

Intermittent fasting results in tissue-specific changes in bioenergetics and redox state.

Directory of Open Access Journals (Sweden)

Bruno Chausse

Full Text Available Intermittent fasting (IF is a dietary intervention often used as an alternative to caloric restriction (CR and characterized by 24 hour cycles alternating ad libitum feeding and fasting. Although the consequences of CR are well studied, the effects of IF on redox status are not. Here, we address the effects of IF on redox state markers in different tissues in order to uncover how changes in feeding frequency alter redox balance in rats. IF rats displayed lower body mass due to decreased energy conversion efficiency. Livers in IF rats presented increased mitochondrial respiratory capacity and enhanced levels of protein carbonyls. Surprisingly, IF animals also presented an increase in oxidative damage in the brain that was not related to changes in mitochondrial bioenergetics. Conversely, IF promoted a substantial protection against oxidative damage in the heart. No difference in mitochondrial bioenergetics or redox homeostasis was observed in skeletal muscles of IF animals. Overall, IF affects redox balance in a tissue-specific manner, leading to redox imbalance in the liver and brain and protection against oxidative damage in the heart.

Dynamic Balanced Scorecard for companies in the business field of power supply; Dynamic Balanced Scorecard fuer Unternehmen im Geschaeftsfeld der dezentralen Energieversorgung

Energy Technology Data Exchange (ETDEWEB)

Hollmann, M.; Roy, I. [Paderborn Univ. (Germany). Lehrstuhl fuer Nachhaltige Energiekonzepte

2006-06-19

Due to deregulation and liberalisation of the power market and due to the opting out of the nuclear energy, the decentralized power supply increasingly gains in importance in comparison to the classical power supply. Thus, the entrepreneur who wants to engage in the decentralized power supply needs a management tool for conversion and supervision his strategy. A pertinent means for this already is the Dynamic Balanced Scorecard. By means of an evaluation of a simple balanced scorecard, the entrepreneur realizes his vision and strategy in order to determine the success-critical factors. These success-critical factors are related together in a causal chain. By this, the entrepreneur can recognize, what has to be done in order to act successfully on the market, and in order to secure the success on a long-term basis. The modelling of the Dynamic balanced Scorecard enables the examination of the corporate strategy, before it is implemented in the enterprise. Thus, the entrepreneur saves time and minimizes the corporate risk.

IAEA Technical Meeting on Status of IAEA Fast Reactor Knowledge Preservation Initiative. Presentations

International Nuclear Information System (INIS)

2013-01-01

The objectives of the technical meeting were to: • exchange information between the Member States/International Organizations on national and international initiatives addressing knowledge preservation and data retrieval/collection in the field of fast neutron systems; • present and discuss the Member States’/International Organizations’ policies and conditions for releasing to the IAEA both publicly available and confidential information on fast neutron systems; • collect data on fast neutron systems provided by participating Member States/International Organizations and encourage participants to contribute in data collection; • provide recommendations for further IAEA initiatives in the field of fast reactor knowledge preservation

The development of fast simulation program for marine reactor parameters

International Nuclear Information System (INIS)

Chen Zhiyun; Hao Jianli; Chen Wenzhen

2012-01-01

Highlights: ► The simplified physical and mathematical models are proposed for a marine reactor system. ► A program is developed with Simulink module and Matlab file. ► The program developed has the merit of easy input preparation, output processing and fast running. ► The program can be used for the fast simulation of marine reactor parameters on the operating field. - Abstract: The fast simulation program for marine reactor parameters is developed based on the Simulink simulating software according to the characteristics of marine reactor with requirement of maneuverability and acute and fast response. The simplified core physical and thermal model, pressurizer model, steam generator model, control rod model, reactivity model and the corresponding Simulink modules are established. The whole program is developed by coupling all the Simulink modules. Two typical transient processes of marine reactor with fast load increase at low power level and load rejection at high power level are adopted to verify the program. The results are compared with those of Relap5/Mod3.2 with good consistency, and the program runs very fast. It is shown that the program is correct and suitable for the fast and accurate simulation of marine reactor parameters on the operating field, which is significant to the marine reactor safe operation.

FAST: FAST Analysis of Sequences Toolbox

Directory of Open Access Journals (Sweden)

Travis J. Lawrence

2015-05-01

Full Text Available FAST (FAST Analysis of Sequences Toolbox provides simple, powerful open source command-line tools to filter, transform, annotate and analyze biological sequence data. Modeled after the GNU (GNU’s Not Unix Textutils such as grep, cut, and tr, FAST tools such as fasgrep, fascut, and fastr make it easy to rapidly prototype expressive bioinformatic workflows in a compact and generic command vocabulary. Compact combinatorial encoding of data workflows with FAST commands can simplify the documentation and reproducibility of bioinformatic protocols, supporting better transparency in biological data science. Interface self-consistency and conformity with conventions of GNU, Matlab, Perl, BioPerl, R and GenBank help make FAST easy and rewarding to learn. FAST automates numerical, taxonomic, and text-based sorting, selection and transformation of sequence records and alignment sites based on content, index ranges, descriptive tags, annotated features, and in-line calculated analytics, including composition and codon usage. Automated content- and feature-based extraction of sites and support for molecular population genetic statistics makes FAST useful for molecular evolutionary analysis. FAST is portable, easy to install and secure thanks to the relative maturity of its Perl and BioPerl foundations, with stable releases posted to CPAN. Development as well as a publicly accessible Cookbook and Wiki are available on the FAST GitHub repository at https://github.com/tlawrence3/FAST. The default data exchange format in FAST is Multi-FastA (specifically, a restriction of BioPerl FastA format. Sanger and Illumina 1.8+ FastQ formatted files are also supported. FAST makes it easier for non-programmer biologists to interactively investigate and control biological data at the speed of thought.

Simulation of a Centrifugal Pump by Using the Harmonic Balance Method

Directory of Open Access Journals (Sweden)

Franco Magagnato

2015-01-01

Full Text Available The harmonic balance method was used for the flow simulation in a centrifugal pump. Independence studies have been done to choose proper number of harmonic modes and inlet eddy viscosity ratio value. The results from harmonic balance method show good agreements with PIV experiments and unsteady calculation results (which is based on the dual time stepping method for the predicted head and the phase-averaged velocity. A detailed analysis of the flow fields at different flow rates shows that the flow rate has an evident influence on the flow fields. At 0.6Qd, some vortices begin to appear in the impeller, and at 0.4Qd some vortices have blocked the flow passage. The flow fields at different positions at 0.6Qd and 0.4Qd show how the complicated flow phenomena are forming, developing, and even disappearing. The harmonic balance method can be used for the flow simulation in pumps, showing the same accuracy as unsteady methods, but is considerably faster.

Balancing Chemical Equations: The Role of Developmental Level and Mental Capacity.

Science.gov (United States)

Niaz, Mansoor; Lawson, Anton E.

1985-01-01

Tested two hypotheses: (1) formal reasoning is required to balance simple one-step equations; and (2) formal reasoning plus sufficient mental capacity are required to balance many-step equations. Independent variables included intellectual development, mental capacity, and degree of field dependence/independence. With 25 subjects, significance was…

Measurement control design and performance assessment in the Integral Fast Reactor fuel cycle

International Nuclear Information System (INIS)

Orechwa, Y.; Bucher, R.G.

1994-01-01

The Integral Fast Reactor (IFR)--consisting of a metal fueled and liquid metal cooled reactor together with an attendant fuel cycle facility (FCF)--is currently undergoing a phased demonstration of the closed fuel cycle at Argonne National Laboratory. The recycle technology is pyrometalurgical based with incomplete fission product separation and all transuranics following plutonium for recycle. The equipment operates in batch mode at 500 to 1,300 C. The materials are highly radioactive and pyrophoric, thus the FCF requires remote operation. Central to the material control and accounting system for the FCF are the balances for mass measurements. The remote operation of the balances limits direct adjustment. The radiation environment requires that removal and replacement of the balances be minimized. The uniqueness of the facility precludes historical data for design and performance assessment. To assure efficient operation of the facility, the design of the measurement control system has called for procedures which assess the performance of the balances in great detail and will support capabilities for the correction of systematic changes in the performance of the balances through software

Osmoregulation during Long-Term Fasting in Lungfish and Elephant Seal: Old and New Lessons for the Nephrologist.

Science.gov (United States)

Rossier, Bernard C

2016-01-01

Vertebrates control the osmolality of their extra- and intra-cellular compartments despite large variations in salt and water intake. Aldosterone-dependent sodium reabsorption and vasopressin-dependent water transport in the distal nephron and collecting duct play a critical role in the final control of sodium and water balance. Long-term fasting (no eating, no drinking) represents an osmotic challenge for survival. Evolution has found very different solutions to meet this challenge. To illustrate this point, I will discuss osmoregulation of a mammal (elephant seal pup) and of a fish (lungfish) that are able to survive long-term fasting for months or even years. Homer W. Smith taught us how informative comparative anatomy and physiology of the kidney could help physiologists and nephrologists to better understand how the kidney works. In recent years, comparative genomics, transcriptomics and proteomics across the tree of life have led to the emergence of a new discipline, evolutionary medicine. In the near future, physiologists and nephrologists will benefit from this new field of investigation, thanks to its potential for the identification of novel drug targets and therapies. © 2016 S. Karger AG, Basel.

Fast reactor database. 2006 update

International Nuclear Information System (INIS)

2006-12-01

Liquid metal cooled fast reactors (LMFRs) have been under development for about 50 years. Ten experimental fast reactors and six prototype and commercial size fast reactor plants have been constructed and operated. In many cases, the overall experience with LMFRs has been rather good, with the reactors themselves and also the various components showing remarkable performances, well in accordance with the design expectations. The fast reactor system has also been shown to have very attractive safety characteristics, resulting to a large extent from the fact that the fast reactor is a low pressure system with large thermal inertia and negative power and temperature coefficients. In addition to the LMFRs that have been constructed and operated, more than ten advanced LMFR projects have been developed, and the latest designs are now close to achieving economic competitivity with other reactor types. In the current world economic climate, the introduction of a new nuclear energy system based on the LMFR may not be considered by utilities as a near future option when compared to other potential power plants. However, there is a strong agreement between experts in the nuclear energy field that, for sustainability reasons, long term development of nuclear power as a part of the world's future energy mix will require the fast reactor technology, and that, given the decline in fast reactor development projects, data retrieval and knowledge preservation efforts in this area are of particular importance. This publication contains detailed design data and main operational data on experimental, prototype, demonstration, and commercial size LMFRs. Each LMFR plant is characterized by about 500 parameters: physics, thermohydraulics, thermomechanics, by design and technical data, and by relevant sketches. The focus is on practical issues that are useful to engineers, scientists, managers, university students and professors with complete technical information of a total of 37 LMFR

Balance and behavior of gaseous radionuclides released during initial fast reactor fuel reprocessing operations

International Nuclear Information System (INIS)

Leudet, A.; Goumondy, J.P.; Charrier, G.

1985-10-01

Five pins from the fast reactor Phenix are cut and dissolved in a specially designed cell for the accurate determination of gas released during the operation. Amount and activity of gaseous radionuclides: Kr, Xe, Kr-85, I, I-129, H-3 and C-14 are determined in the fuel pins and also their distribution between shearing and dissolution [fr

Professional Balance and it’s Psychological Valences

Directory of Open Access Journals (Sweden)

Mariana ZUBENSCHI

2017-06-01

Full Text Available The harmony in the workplace of psycho-emotional stability, presents a revolutionary assurance of balance theory, launched in 1958, by the notorious scholar in cognitive psychology Fritz Heider, who studied at the Institute of Psychology in Berlin, with Kohler, Wertheimer and Lewin. Heider researched the environmental factors and their perception by different objects. The balance theory demonstrates a broad applicability in socio-psychology as it addresses either classical research, or attribution, or exploration of new attributive ideas and extensions: such as implicit causality of the verb in communication. Also, the balance theory provides apprehensions about the mechanism of causal reasoning that underlies at the retrospective base of prejudice, also about the justification of personal actions by attributing relational models, and the attribution of errors and successes in the contexts of organizational psychology. The balance theory in professional field, assumes the phrase of an adequate mental state in carrying out the professional activity. Therefore, an increasing number of employed people, became concerned about the ability to achieve the balance between the professional and the personal sphere, which was called "the Graal of the job" by Buckner and Sandholz in 2003. This article, comes with the novelty, in disscussing the relations of psychosocial components on professional balance.

Slow Versus Fast Robot-Assisted Locomotor Training After Severe Stroke: A Randomized Controlled Trial.

Science.gov (United States)

Rodrigues, Thais Amanda; Goroso, Daniel Gustavo; Westgate, Philip M; Carrico, Cheryl; Batistella, Linamara R; Sawaki, Lumy

2017-10-01

Robot-assisted locomotor training on a bodyweight-supported treadmill is a rehabilitation intervention that compels repetitive practice of gait movements. Standard treadmill speed may elicit rhythmic movements generated primarily by spinal circuits. Slower-than-standard treadmill speed may elicit discrete movements, which are more complex than rhythmic movements and involve cortical areas. Compare effects of fast (i.e., rhythmic) versus slow (i.e., discrete) robot-assisted locomotor training on a bodyweight-supported treadmill in subjects with chronic, severe gait deficit after stroke. Subjects (N = 18) were randomized to receive 30 sessions (5 d/wk) of either fast or slow robot-assisted locomotor training on a bodyweight-supported treadmill in an inpatient setting. Functional ambulation category, time up and go, 6-min walk test, 10-m walk test, Berg Balance Scale, and Fugl-Meyer Assessment were administered at baseline and postintervention. The slow group had statistically significant improvement on functional ambulation category (first quartile-third quartile, P = 0.004), 6-min walk test (95% confidence interval [CI] = 1.8 to 49.0, P = 0.040), Berg Balance Scale (95% CI = 7.4 to 14.8, P locomotor training on a bodyweight-supported treadmill after severe stroke, slow training targeting discrete movement may yield greater benefit than fast training.

A Modularized Discharge-Type Balancing Topology for Series-Connected Super Capacitor String

Directory of Open Access Journals (Sweden)

Shaogui Fan

2018-06-01

Full Text Available This paper proposed a modularized discharge-type topology for the voltage balance of series-connected super capacitor (SC string. The proposed topology consists of cascaded converter modules and a boost converter. The cascaded converter modules discharge the higher voltage SCs directly with the ideal output current to realize a fast balancing speed and the boost converter feedbacks the extra energy from the higher voltage SCs to the super capacitor energy storage system (SCESS. The modular design of the cascaded converter modules makes the balancing system suitable for different voltage levels of SCESS. Unlike the charge-type topologies which discharge the higher voltage SCs indirectly, the proposed topology discharges the higher voltage SCs directly with a big current, and the over voltage phenomenon of SCs is then avoided, which means the reliability of the SCESS can be improved. The voltage stress of the switches inside the cascaded converter modules is low, which is different from the existing modularized discharge-type balancing topology. What is more, the control of cascaded converter modules and the boost converter can be implemented by analog devices which will simplify the control of the whole system. The control degree of freedom is high and the voltage of each cell can be controlled. An in-depth comparison analysis with the charge-type balancing topology is performed from the perspective of balancing speed and round-trip energy efficiency. The proposed topology and the balancing performance are confirmed by experimental results.

Collisional destruction of fast hydrogen Rydberg atoms

International Nuclear Information System (INIS)

King, M.R.

1984-01-01

A new modulated electric field technique was developed to study Rydberg atom destruction processes in a fast beam. The process of destruction of a band of Rydberg atom destruction of a band of Rydberg atoms through the combined processes of ionization, excitation, and deexcitation was studied for collisions with gas targets. Rydberg atoms of hydrogen were formed by electron capture, and detected by field ionization. The modulated field technique described proved to be an effective technique for producing a large signal for accurate cross section measurements. The independent particle model for Rydberg atom destruction processes was found to hold well for collisions with molecular nitrogen, argon, and carbon dioxide. The resonances in the cross sections for the free electron scattering with these targets were found to also occur in Rydberg destruction. Suggestions for future investigations of Rydberg atom collision processes in the fast beam regime are given

A Randomized Field Trial of the Fast ForWord Language Computer-Based Training Program

Science.gov (United States)

Borman, Geoffrey D.; Benson, James G.; Overman, Laura

2009-01-01

This article describes an independent assessment of the Fast ForWord Language computer-based training program developed by Scientific Learning Corporation. Previous laboratory research involving children with language-based learning impairments showed strong effects on their abilities to recognize brief and fast sequences of nonspeech and speech…

The Biases of Thinking Fast and Thinking Slow

OpenAIRE

Streeb, Dirk; Chen, Min; Keim, Daniel A.

2017-01-01

Visualization is a human-centric process, which is inevitably as- sociated with potential biases in humans’ judgment and decision making. While the discussions on humans’ biases have been heavily influenced the work of Daniel Kahneman as summarized in his book “Thinking, Fast and Slow” [8], there have also been viewpoints in psychology in favor of heuristics (e.g., [6]). In this paper, we present a balanced discourse on the humans’ heuristics and biases as the two sides of the same coin. In p...

Energy balance in a coaxial plasma diode

International Nuclear Information System (INIS)

Ivanov, A.A. Jr.

1999-01-01

The energy fluxes in a coaxial system with a propagating convective magnetic-field wave are considered in an electron MHD model with inertia-free electrons. In contrast to the previous results obtained by other authors, it is shown that, with allowance for a finite electron pressure after the passage of the wave front, the energy flux at the boundary between the generator and coaxial system is continuous. The balance of energy fluxes in the system is studied. The angular anode point is shown to play an important role in this balance

Characteristics of a stable arc based on FAST and MIRACLE observations

Directory of Open Access Journals (Sweden)

P. Janhunen

2000-02-01

Full Text Available A stable evening sector arc is studied using observations from the FAST satellite at 1250 km altitude and the MIRACLE ground-based network, which contains all-sky cameras, coherent radars (STARE, and magnetometers. Both FAST and STARE observe a northward electric field region of about 200 km width and a field magnitude of about 50 mV/m southward of the arc, which is a typical signature for an evening-sector arc. The field-aligned current determined from FAST electron and magnetometer data are in rather good agreement within the arcs. Outside the arcs, the electron data misses the current carriers of the downward FAC probably because it is mainly carried by electrons of smaller energy than the instrument threshold. Studying the westward propagation speed of small undulations associated with the arc using the all-sky cameras gives a velocity of about 2 km/s. This speed is higher than the background ionospheric plasma speed (about 1 km/s, but it agrees rather well with the idea originally proposed by Davis that the undulations reflect an E × B motion in the acceleration region. The ground magnetograms indicate that the main current flows slightly south of the arc. Computing the ionospheric conductivity from FAST electron data and using the ground magnetograms to estimate the current yields an ionospheric electric field pattern, in rather good agreement with FAST results.Key words: Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions - Magnetospheric physics (auroral phenomena

SU(8) family unification with boson-fermion balance

CERN Multimedia

CERN. Geneva

2014-01-01

Grand unification has been intensively investigated for over forty years, and many different approaches have been tried. In this talk I propose a model that involves three ingredients that do not appear in the usual constructions: (1) boson--fermion balance without full supersymmetry, (2) canceling the spin 1/2 fermion gauge anomalies against the anomaly from a gauged spin 3/2 gravitino, and (3) using a scalar field representation with non-zero U(1) generator to break the SU(8) gauge symmetry through a ground state which, before dynamical symmetry breaking, has a periodic U(1) generator structure. The model has a number of promising features: (1) natural incorporation of three families, (2) incorporation of the experimentally viable flipped SU(5) model, (3) a symmetry breaking pathway to the standard model using the scalar field required by boson-fermion balance, together with a stage of most attractive channel dynamical symmetry breaking, without postulating additional Higgs fields, (4) vanishing of bare Yuk...

Fast-ion stabilization of tokamak plasma turbulence

Science.gov (United States)

Di Siena, A.; Görler, T.; Doerk, H.; Poli, E.; Bilato, R.

2018-05-01

A significant reduction of the turbulence-induced anomalous heat transport has been observed in recent studies of magnetically confined plasmas in the presence of a significant fast-ion fractions. Therefore, the control of fast-ion populations with external heating might open the way to more optimistic scenarios for future fusion devices. However, little is known about the parameter range of relevance of these fast-ion effects which are often only highlighted in correlation with substantial electromagnetic fluctuations. Here, a significant fast ion induced stabilization is also found in both linear and nonlinear electrostatic gyrokinetic simulations which cannot be explained with the conventional assumptions based on pressure profile and dilution effects. Strong wave-fast particle resonant interactions are observed for realistic parameters where the fast particle trace approximation clearly failed and explained with the help of a reduced Vlasov model. In contrast to previous interpretations, fast particles can actively modify the Poisson field equation—even at low fast particle densities where dilution tends to be negligible and at relatively high temperatures, i.e. T  <  30T e . Further key parameters controlling the role of the fast ions are identified in the following and various ways of further optimizing their beneficial impact are explored. Finally, possible extensions into the electromagnetic regime are briefly discussed and the relevance of these findings for ITER standard scenarios is highlighted.

Two-dimensional fast marching for geometrical optics.

Science.gov (United States)

Capozzoli, Amedeo; Curcio, Claudio; Liseno, Angelo; Savarese, Salvatore

2014-11-03

We develop an approach for the fast and accurate determination of geometrical optics solutions to Maxwell's equations in inhomogeneous 2D media and for TM polarized electric fields. The eikonal equation is solved by the fast marching method. Particular attention is paid to consistently discretizing the scatterers' boundaries and matching the discretization to that of the computational domain. The ray tracing is performed, in a direct and inverse way, by using a technique introduced in computer graphics for the fast and accurate generation of textured images from vector fields. The transport equation is solved by resorting only to its integral form, the transport of polarization being trivial for the considered geometry and polarization. Numerical results for the plane wave scattering of two perfectly conducting circular cylinders and for a Luneburg lens prove the accuracy of the algorithm. In particular, it is shown how the approach is capable of properly accounting for the multiple scattering occurring between the two metallic cylinders and how inverse ray tracing should be preferred to direct ray tracing in the case of the Luneburg lens.

Concept of a staged FEL enabled by fast synchrotron radiation cooling of laser-plasma accelerated beam by solenoidal magnetic fields in plasma bubble

Science.gov (United States)

Seryi, Andrei; Lesz, Zsolt; Andreev, Alexander; Konoplev, Ivan

2017-03-01

A novel method for generating GigaGauss solenoidal fields in a laser-plasma bubble, using screw-shaped laser pulses, has been recently presented. Such magnetic fields enable fast synchrotron radiation cooling of the beam emittance of laser-plasma accelerated leptons. This recent finding opens a novel approach for design of laser-plasma FELs or colliders, where the acceleration stages are interleaved with laser-plasma emittance cooling stages. In this concept paper, we present an outline of what a staged plasma-acceleration FEL could look like, and discuss further studies needed to investigate the feasibility of the concept in detail.

SEMIC: an efficient surface energy and mass balance model applied to the Greenland ice sheet

Directory of Open Access Journals (Sweden)

M. Krapp

2017-07-01

Full Text Available We present SEMIC, a Surface Energy and Mass balance model of Intermediate Complexity for snow- and ice-covered surfaces such as the Greenland ice sheet. SEMIC is fast enough for glacial cycle applications, making it a suitable replacement for simpler methods such as the positive degree day (PDD method often used in ice sheet modelling. Our model explicitly calculates the main processes involved in the surface energy and mass balance, while maintaining a simple interface and requiring minimal data input to drive it. In this novel approach, we parameterise diurnal temperature variations in order to more realistically capture the daily thaw–freeze cycles that characterise the ice sheet mass balance. We show how to derive optimal model parameters for SEMIC specifically to reproduce surface characteristics and day-to-day variations similar to the regional climate model MAR (Modèle Atmosphérique Régional, version 2 and its incorporated multilayer snowpack model SISVAT (Soil Ice Snow Vegetation Atmosphere Transfer. A validation test shows that SEMIC simulates future changes in surface temperature and surface mass balance in good agreement with the more sophisticated multilayer snowpack model SISVAT included in MAR. With this paper, we present a physically based surface model to the ice sheet modelling community that is general enough to be used with in situ observations, climate model, or reanalysis data, and that is at the same time computationally fast enough for long-term integrations, such as glacial cycles or future climate change scenarios.

A Survey of Empty Container Flow Balance in Turkish Ports

Directory of Open Access Journals (Sweden)

Ünal ÖZDEMİR

2015-11-01

Full Text Available Container transportation is the most preferred maritime commercial freight distribution in entire world except liquefied product transportation by tankers and bulk carriers. Totally 95% volume of general cargo is transported by container ships in the world due to fast, cheap and safe carrying potential of the goods transfer. Containerization has become recent phenomena in the field of maritime transportation and the quantity of goods transported by containers is increasing day by day as well as the total container number to use for the commercial activity. Due to very high mobility in the field of container transportation, port traffic estimation, availability of containers, storage, deposition and allocation of empty containers have become recent problems in maritime transportation area. In this study some major container ports of Turkey which are stand for 80 % of total container operations are analyzed to seek for empty container balance. After detailed statistical evaluation of national container transportation figures for Haydarpaşa, Kumport, İzmir, Mardaş, Marport and Mersin, several interviews and discussions have been made with port authorities and governing departments. As a result, it is observed that there is no empty container accumulation problem in the examined ports except Haydarpaşa and Kumport. Based on general statistics, Turkish container ports currently do not suffer from empty container problem as overall container circulation close to equilibrium but the problem has a potential to create a risk on developing international trade of Turkey.

Fast electron generation and transport in a turbulent, magnetized plasma

International Nuclear Information System (INIS)

Stoneking, W.R.

1994-05-01

The nature of fast electron generation and transport in the Madison Symmetric Torus (MST) reversed field pinch (RFP) is investigated using two electron energy analyzer (EEA) probes and a thermocouple calorimeter. The parallel velocity distribution of the fast electron population is well fit by a drifted Maxwellian distribution with temperature of about 100 eV and drift velocity of about 2 x 10 6 m/s. Cross-calibration of the EEA with the calorimeter provides a measurement of the fast electron perpendicular temperature of 30 eV, much lower than the parallel temperature, and is evidence that the kinetic dynamo mechanism (KDT) is not operative in MST. The fast electron current is found to match to the parallel current at the edge, and the fast electron density is about 4 x 10 11 cm -3 independent of the ratio of the applied toroidal electric field to the critical electric field for runaways. First time measurements of magnetic fluctuation induced particle transport are reported. By correlating electron current fluctuations with radial magnetic fluctuations the transported flux of electrons is found to be negligible outside r/a∼0.9, but rises the level of the expected total particle losses inside r/a∼0.85. A comparison of the measured diffusion coefficient is made with the ausilinear stochastic diffusion coefficient. Evidence exists that the reduction of the transport is due to the presence of a radial ambipolar electric field of magnitude 500 V/m, that acts to equilibrate the ion and electron transport rates. The convective energy transport associated with the measured particle transport is large enough to account for the observed magnetic fluctuation induced energy transport in MST

Status of the DEBENE fast breeder reactor development, March 1979

International Nuclear Information System (INIS)

Daeunert, U.; Kessler, G.

1979-01-01

Status report of the Fast-breeder reactor development in Germany covers the following: description of the political situation in Federal republic of germany during 1978; international cooperation in the field of fast reactor technology development; operation description of the KNK-II fast core experimental power plant; status of construction of the SNR-300; results of the research and development programs concerned with fuel element, cladding, absorber rods and core structural materials development; sodium effects; neutron irradiation effects on SS properties; reactor physics related to experiments in fast critical assemblies; fast reactor safety issues; core disruption accidents; sodium boiling experiments, measuring methods developed; component tests

Status of the DEBENE fast breeder reactor development, March 1979

Energy Technology Data Exchange (ETDEWEB)

Daeunert, U; Kessler, G

1979-07-01

Status report of the Fast-breeder reactor development in Germany covers the following: description of the political situation in Federal republic of germany during 1978; international cooperation in the field of fast reactor technology development; operation description of the KNK-II fast core experimental power plant; status of construction of the SNR-300; results of the research and development programs concerned with fuel element, cladding, absorber rods and core structural materials development; sodium effects; neutron irradiation effects on SS properties; reactor physics related to experiments in fast critical assemblies; fast reactor safety issues; core disruption accidents; sodium boiling experiments, measuring methods developed; component tests.

3D wake measurements from a scanning wind lidar in combination with a fast wind field reconstruction model

DEFF Research Database (Denmark)

Mikkelsen, Torben Krogh; Herges, T. G.; Astrup, Poul

2017-01-01

University of Denmark. The purpose of the SpinnerLidar measurements at SWIFT is to measure the response of a V27 turbine wake to varying inflow conditions and turbine operating states. Although our fast scanning SpinnerLidar is able to measure the line-of-sight projected wind speed at up to 400 points per......-Stokes CFD code “Lincom Cyclop-buster model,”3 the corresponding 3D wind vector field (u, v, w) can be reconstructed under constraints for conservation of mass and momentum. The resulting model calculated line-of-sight projections of the 3D wind velocity vectors will become consistent with the line...

Balancing of generators at wind power plants. Operational balancing in normal operation at wind power plants; Auswuchten von Generatoren auf Windkraftanlagen. Betriebsauswuchten im Normalbetrieb der Windkraftanlage

Energy Technology Data Exchange (ETDEWEB)

Franke, Dieter [IDF vibrodiagnose GmbH, Dresden (Germany); Schmidt, Gerrit [WSB Service GmbH (Germany)

2010-07-01

An increasing or suddenly arising unbalanced state in the generator of a wind power plant can be recognized by means of condition monitoring systems and regularly accomplished oscillation diagnoses. A strong unbalanced state results in a fast bearing wear, increases the risk of outage and reduces the profit. The risk of a further damage of the generator by means of a clearly increased vibration severity often is substantial. The counterbalancing takes place at the extended rotor at work benches in workshops. Among other things, the substantial cost is based on the expense of the disassembly and remounting of the generator. The total costs may amount several ten thousand Euro. As an alternative to balancing in the workshop, an operating balancing is recommended on the plant in order to reduce the costs. This was successfully realized by the engineer's office IDF vibrodiagnose GmbH (Dresden, Federal Republic of Germany) by the example of a Vestas V44 plant. The authors of the contribution under consideration describe the approach and advantages of an operating balancing. The main vibration stimulation at generators are described.

Particle-in-cell studies of fast-ion slowing-down rates in cool tenuous magnetized plasma

Science.gov (United States)

Evans, Eugene S.; Cohen, Samuel A.; Welch, Dale R.

2018-04-01

We report on 3D-3V particle-in-cell simulations of fast-ion energy-loss rates in a cold, weakly-magnetized, weakly-coupled plasma where the electron gyroradius, ρe, is comparable to or less than the Debye length, λDe, and the fast-ion velocity exceeds the electron thermal velocity, a regime in which the electron response may be impeded. These simulations use explicit algorithms, spatially resolve ρe and λDe, and temporally resolve the electron cyclotron and plasma frequencies. For mono-energetic dilute fast ions with isotropic velocity distributions, these scaling studies of the slowing-down time, τs, versus fast-ion charge are in agreement with unmagnetized slowing-down theory; with an applied magnetic field, no consistent anisotropy between τs in the cross-field and field-parallel directions could be resolved. Scaling the fast-ion charge is confirmed as a viable way to reduce the required computational time for each simulation. The implications of these slowing down processes are described for one magnetic-confinement fusion concept, the small, advanced-fuel, field-reversed configuration device.

Fast ion beam-laser interactions

International Nuclear Information System (INIS)

Berry, H.G.; Young, L.; Engstroem, L.; Hardis, J.E.; Somerville, L.P.; Ray, W.J.; Kurtz, C.

1985-01-01

The authors are using collinear laser excitation of fast ion beams to study a number of atomic structure problems. The problems include the determination of fine and hyperfine structure in light positive and negative ions, plus measurements of absolute wavelengths of light from two-electron ions. In addition the authors intend to use a similar experimental arrangement to study excitation and decay of high Rydberg states first in the absence of fields and then in crossed electric and magnetic fields

Balancing the dual responsibilities of business unit controllers: field and survey evidence

NARCIS (Netherlands)

Maas, V.S.; Matejka, M.

2009-01-01

We examine how business unit (BU) controllers balance their dual roles of providing information for both local decision-making (local responsibility) and corporate control (functional responsibility). The existing literature suggests that organizations can improve the quality of financial reporting

INTERVENTIONS FOR INCREASING BALANCE & CONFIDENCE IN OLDER ADULTS: A REVIEW

OpenAIRE

Foram Dhebar

2014-01-01

Elderly is defined as being 65 years of age or older. Geriatrics or geriatric medicine is a specialty that focuses on health care of elderly people. The number of persons above the age of 60 years is fast growing, especially in India. Falls are the leading cause of traumatic brain injury, fractures & the leading cause of emergency department visits by older adults. Low balance confidence is a major health problem among older adults restricting their participation in daily life. Objective of t...

Comparação entre testes de equilíbrio de campo e plataforma de força Comparison between field balance tests and force platform

Directory of Open Access Journals (Sweden)

Renata Alyne Czajka Sabchuk

2012-12-01

Full Text Available Vários testes de equilíbrio têm sido utilizados para identificar o controle postural e o risco de quedas em idosos. Entretanto, não se sabe quais testes refletem mais efetivamente a capacidade em manter o equilíbrio. O objetivo deste estudo foi comparar um conjunto de testes de campo de equilíbrio (TC com os testes de posturografia em plataforma de força (PF e verificar se esses testes são capazes de discriminar diferenças no equilíbrio entre jovens e idosos. Participaram do estudo 21 jovens (21,7 ± 2,0 anos e 18 idosos (69,3 ± 7,0 anos de ambos os gêneros. Os TC foram: escala de equilíbrio de Berg (BBS, escala de equilíbrio orientado pelo desempenho, (POMA, alcance funcional (AF e levantar e caminhar cronometrado (TUGT. As variáveis analisadas na PF foram: amplitude de deslocamento nas direções anteroposterior (AMP-AP e médio-lateral (AMP-ML e trajetória do centro de pressão (TRAJ-CP. Os sujeitos foram avaliados em cinco condições durante 60s cada. Uma ANOVA one-way foi aplicada para determinar diferenças nos testes de equilíbrio entre grupos (jovens x idosos. Além disso, o teste de correlação de Spearman foi aplicado para identificar a associação entre os TC e PF. Os TC foram capazes de diferenciar jovens de idosos (p Several balance tests have been used to identify postural control and the risk of falls in the elderly. However, it is not known which tests better reflect effectively the ability to maintain balance. The objective of this study was to compare a number of field tests (FT designed to determine balance with stabilometric tests using force platforms (FP to determine whether these tests are able to discriminate differences in balance between young and older adults. Twenty-one young (21.7±2.0 years and 18 older adults (69.3±7.0 years of both genders volunteered to participate in the study. The field tests were: Berg Balance Scale (BBS, Performance Oriented Mobility Assessment (POMA, Functional Reach (FR

Teaching Children To Love: 80 Games & Fun Activities for Raising Balanced Children in Unbalanced Times.

Science.gov (United States)

Childre, Doc Lew; Paddison, Sara Hatch, Ed.

Raising children in today's fast-paced society requires love and technique. Ways that parents can teach children to love, teach them values, and help them balance their lives are discussed in this activity book. The text opens with a discussion of heart intelligence (what is sometimes equated with emotional intelligence). Heart intelligence…

基于LabVIEW的现场动平衡测试系统的开发%Development of field dynamic balance testing system based on LabVIEW

Institute of Scientific and Technical Information of China (English)

粱召华; 李智

2014-01-01

In order to adapt to the needs of the rotor field dynamic balance and improve the testing accuracy,the field dy-namic balance testing system based on virtual instrument technology was developed,which uses correlation method to extract the amplitude and phase of the vibration signal accurately , and adopts single-side dynamic balance and double-side dynamic balance method based on influence coefficient method to do the dynamic balance experiment. Many rotor dynamic balance experi-ments on the multi-function rotor testing bench show that the unbalance vibration has been effectively suppressed and the vibra-tion amplitude has been reduced obviously after adding appropriate testing weight on the rotor. This has important significance for reducing machine noise and the bearing wear,and improving the performance and life of the machine. It is also helpful to im-prove the machine's work efficiency and to ensure the safety of machining operators.%为了适应转子现场动平衡的需要，提高测试精度，开发了基于虚拟仪器技术的现场动平衡测试系统，它利用相关法准确提取出振动信号的幅值和相位，采用基于影响系数法的单面动平衡和双面动平衡的方法进行动平衡实验。通过在多功能转子试验台上做了多次转子动平衡试验，实验结果表明：转子在加适当的试重后不平衡振动得到了有效的抑制，振动幅度明显减小。这对于减小机器噪声和轴承磨损，提高机器的性能和寿命有着重要意义，同时也有助于提高机器的工作效率和保障机械加工操作者的安全。

Fast modal decomposition for optical fibers using digital holography.

Science.gov (United States)

Lyu, Meng; Lin, Zhiquan; Li, Guowei; Situ, Guohai

2017-07-26

Eigenmode decomposition of the light field at the output end of optical fibers can provide fundamental insights into the nature of electromagnetic-wave propagation through the fibers. Here we present a fast and complete modal decomposition technique for step-index optical fibers. The proposed technique employs digital holography to measure the light field at the output end of the multimode optical fiber, and utilizes the modal orthonormal property of the basis modes to calculate the modal coefficients of each mode. Optical experiments were carried out to demonstrate the proposed decomposition technique, showing that this approach is fast, accurate and cost-effective.

Including spatial data in nutrient balance modelling on dairy farms

Science.gov (United States)

van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

2017-04-01

The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies

Construction schedule management of China Experimental Fast Reactor

International Nuclear Information System (INIS)

Wang Yue

2012-01-01

China Experimental Fast Reactor (CEFR) in the first Fast Reactor in China, which is one of large project of the National High Technology Research and Development Program ('863' Program). On 21 st July 2011, CEFR had succeeded to connect to power grid, the target of construction had come true. To a large item, schedule management is one of the most important management, this paper a overall discussion about CEFR item. It has proved that the management of CEFR project is scientific, normative and high-efficiency, it will be valuable for lager Fast Reactor item and designers in interrelated field. (author)

Fast Winds and Mass Loss from Metal-Poor Field Giants

Science.gov (United States)

Dupree, A. K.; Smith, Graeme H.; Strader, Jay

2009-11-01

Echelle spectra of the infrared He I λ10830 line were obtained with NIRSPEC on the Keck 2 telescope for 41 metal-deficient field giant stars including those on the red giant branch (RGB), asymptotic giant branch (AGB), and red horizontal branch (RHB). The presence of this He I line is ubiquitous in stars with T effgsim 4500 K and MV fainter than -1.5, and reveals the dynamics of the atmosphere. The line strength increases with effective temperature for T effgsim 5300 K in RHB stars. In AGB and RGB stars, the line strength increases with luminosity. Fast outflows (gsim 60 km s-1) are detected from the majority of the stars and about 40% of the outflows have sufficient speed as to allow escape of material from the star as well as from a globular cluster. Outflow speeds and line strengths do not depend on metallicity for our sample ([Fe/H]= -0.7 to -3.0), suggesting the driving mechanism for these winds derives from magnetic and/or hydrodynamic processes. Gas outflows are present in every luminous giant, but are not detected in all stars of lower luminosity indicating possible variability. Mass loss rates ranging from ~3 × 10-10 to ~6 × 10-8 M sun yr-1 estimated from the Sobolev approximation for line formation represent values with evolutionary significance for red giants and RHB stars. We estimate that 0.2 M sun will be lost on the RGB, and the torque of this wind can account for observations of slowly rotating RHB stars in the field. About 0.1-0.2 M sun will be lost on the RHB itself. This first empirical determination of mass loss on the RHB may contribute to the appearance of extended horizontal branches in globular clusters. The spectra appear to resolve the problem of missing intracluster material in globular clusters. Opportunities exist for "wind smothering" of dwarf stars by winds from the evolved population, possibly leading to surface pollution in regions of high stellar density. Data presented herein were obtained at the W. M. Keck Observatory, which

Maximum Entropy Closure of Balance Equations for Miniband Semiconductor Superlattices

Directory of Open Access Journals (Sweden)

Luis L. Bonilla

2016-07-01

Full Text Available Charge transport in nanosized electronic systems is described by semiclassical or quantum kinetic equations that are often costly to solve numerically and difficult to reduce systematically to macroscopic balance equations for densities, currents, temperatures and other moments of macroscopic variables. The maximum entropy principle can be used to close the system of equations for the moments but its accuracy or range of validity are not always clear. In this paper, we compare numerical solutions of balance equations for nonlinear electron transport in semiconductor superlattices. The equations have been obtained from Boltzmann–Poisson kinetic equations very far from equilibrium for strong fields, either by the maximum entropy principle or by a systematic Chapman–Enskog perturbation procedure. Both approaches produce the same current-voltage characteristic curve for uniform fields. When the superlattices are DC voltage biased in a region where there are stable time periodic solutions corresponding to recycling and motion of electric field pulses, the differences between the numerical solutions produced by numerically solving both types of balance equations are smaller than the expansion parameter used in the perturbation procedure. These results and possible new research venues are discussed.

Fast Output-sensitive Matrix Multiplication

DEFF Research Database (Denmark)

Jacob, Riko; Stöckel, Morten

2015-01-01

We consider the problem of multiplying two $U \\times U$ matrices $A$ and $C$ of elements from a field $\\F$. We present a new randomized algorithm that can use the known fast square matrix multiplication algorithms to perform fewer arithmetic operations than the current state of the art for output...

Fast Response Three Phase Induction Motor Using Indirect Field Oriented Control (IFOC Based On Fuzzy-Backstepping

Directory of Open Access Journals (Sweden)

Rizana Fauzi

2015-06-01

Full Text Available Induction Motor in Electrical drive system at a accelleration speed for example in electric cars have a hard speed setting is set on a wide range, causing an inconvenience for motorists and a fast response is required any change of speed. It is necessary for good system performance in control motor speed and torque at low speed or fast speed response, which is operated by Indirect Field Oriented Control (IFOC. Speed control on IFOC methods should be better to improving the performance of rapid response in the induction motor. In this paper presented a method of incorporation of Fuzzy Logic Controller and Backstepping (Fuzzy-Backstepping to improve the dynamically response speed and torque in Induction Motor on electric car, so we get smoothness at any speed change and braking as well as maximum torque of induction motor. Test results showed that Fuzzy-Backstepping can increase the response to changes speed in electric car. System testing is done with variations of the reference point setting speed control system, the simulation results of the research showed that the IFOC method is not perfect in terms of induction motor speed regulation if it’s not use speed control. Fuzzy-Backstepping control is needed which can improve the response of output, so that the induction motor has a good performance, small oscillations when start working up to speed reference. Keywords: Fuzzy-Backstepping, IFOC, induction motor

Typical balance exercises or exergames for balance improvement?

Science.gov (United States)

Gioftsidou, Asimenia; Vernadakis, Nikolaos; Malliou, Paraskevi; Batzios, Stavros; Sofokleous, Polina; Antoniou, Panagiotis; Kouli, Olga; Tsapralis, Kyriakos; Godolias, George

2013-01-01

Balance training is an effective intervention to improve static postural sway and balance. The purpose of the present study was to investigate the effectiveness of the Nintendo Wii Fit Plus exercises for improving balance ability in healthy collegiate students in comparison with a typical balance training program. Forty students were randomly divided into two groups, a traditional (T group) and a Nintendo Wii group (W group) performed an 8 week balance program. The "W group" used the interactive games as a training method, while the "T group" used an exercise program with mini trampoline and inflatable discs (BOSU). Pre and Post-training participants completed balance assessments. Two-way repeated measures analyses of variance (ANOVAs) were conducted to determine the effect of training program. Analysis of the data illustrated that both training program groups demonstrated an improvement in Total, Anterior-posterior and Medial Lateral Stability Index scores for both limbs. Only at the test performed in the balance board with anterior-posterior motion, the improvement in balance ability was greater in the "T group" than the "W group", when the assessment was performed post-training (p=0.023). Findings support the effectiveness of using the Nintendo Wii gaming console as a balance training intervention tool.

Scalable fast multipole methods for vortex element methods

KAUST Repository

Hu, Qi

2012-11-01

We use a particle-based method to simulate incompressible flows, where the Fast Multipole Method (FMM) is used to accelerate the calculation of particle interactions. The most time-consuming kernelsâ\\'the Biot-Savart equation and stretching term of the vorticity equationâ\\'are mathematically reformulated so that only two Laplace scalar potentials are used instead of six, while automatically ensuring divergence-free far-field computation. Based on this formulation, and on our previous work for a scalar heterogeneous FMM algorithm, we develop a new FMM-based vortex method capable of simulating general flows including turbulence on heterogeneous architectures, which distributes the work between multi-core CPUs and GPUs to best utilize the hardware resources and achieve excellent scalability. The algorithm also uses new data structures which can dynamically manage inter-node communication and load balance efficiently but with only a small parallel construction overhead. This algorithm can scale to large-sized clusters showing both strong and weak scalability. Careful error and timing trade-off analysis are also performed for the cutoff functions induced by the vortex particle method. Our implementation can perform one time step of the velocity+stretching for one billion particles on 32 nodes in 55.9 seconds, which yields 49.12 Tflop/s. © 2012 IEEE.

The Ulysses fast latitude scans: COSPIN/KET results

Directory of Open Access Journals (Sweden)

B. Heber

2003-06-01

Full Text Available Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in December 1997, and its second fast latitude scan in September 2000. In contrast to the first fast latitude scan in 1994/1995, during the second fast latitude scan solar activity was close to maximum. The solar magnetic field reversed its polarity around July 2000. While the first latitude scan mainly gave a snapshot of the spatial distribution of galactic cosmic rays, the second one is dominated by temporal variations. Solar particle increases are observed at all heliographic latitudes, including events that produce >250 MeV protons and 50 MeV electrons. Using observations from the University of Chicago’s instrument on board IMP8 at Earth, we find that most solar particle events are observed at both high and low latitudes, indicating either acceleration of these particles over a broad latitude range or an efficient latitudinal transport. The latter is supported by "quiet time" variations in the MeV electron background, if interpreted as Jovian electrons. No latitudinal gradient was found for >106 MeV galactic cosmic ray protons, during the solar maximum fast latitude scan. The electron to proton ratio remains constant and has practically the same value as in the previous solar maximum. Both results indicate that drift is of minor importance. It was expected that, with the reversal of the solar magnetic field and in the declining phase of the solar cycle, this ratio should increase. This was, however, not observed, probably because the transition to the new magnetic cycle was not completely terminated within the heliosphere, as indicated by the Ulysses magnetic field and solar wind measurements. We argue that the new A<0-solar magnetic modulation epoch will establish itself once both polar coronal holes have developed.Key words. Interplanetary physics (cosmic rays; energetic particles; interplanetary magnetic fields

Adaptive control of dynamic balance in human gait on a split-belt treadmill.

Science.gov (United States)

Buurke, Tom J W; Lamoth, Claudine J C; Vervoort, Danique; van der Woude, Lucas H V; den Otter, Rob

2018-05-17

Human bipedal gait is inherently unstable and staying upright requires adaptive control of dynamic balance. Little is known about adaptive control of dynamic balance in reaction to long-term, continuous perturbations. We examined how dynamic balance control adapts to a continuous perturbation in gait, by letting people walk faster with one leg than the other on a treadmill with two belts (i.e. split-belt walking). In addition, we assessed whether changes in mediolateral dynamic balance control coincide with changes in energy use during split-belt adaptation. In nine minutes of split-belt gait, mediolateral margins of stability and mediolateral foot roll-off changed during adaptation to the imposed gait asymmetry, especially on the fast side, and returned to baseline during washout. Interestingly, no changes in mediolateral foot placement (i.e. step width) were found during split-belt adaptation. Furthermore, the initial margin of stability and subsequent mediolateral foot roll-off were strongly coupled to maintain mediolateral dynamic balance throughout the gait cycle. Consistent with previous results net metabolic power was reduced during split-belt adaptation, but changes in mediolateral dynamic balance control were not correlated with the reduction of net metabolic power during split-belt adaptation. Overall, this study has shown that a complementary mechanism of relative foot positioning and mediolateral foot roll-off adapts to continuously imposed gait asymmetry to maintain dynamic balance in human bipedal gait. © 2018. Published by The Company of Biologists Ltd.

Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains.

Science.gov (United States)

Nielsen, B L

2012-09-01

Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 26°C), one (HC; 16°C to 26°C) or no (CC; 16°C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

Orthostatic intolerance during early mobilization after fast-track hip arthroplasty

DEFF Research Database (Denmark)

Jans, O; Bundgaard-Nielsen, M; Solgaard, S

2012-01-01

has not been established after THA. This study evaluated the cardiovascular response and tissue oxygenation to mobilization before and after surgery in relation to OI in fast-track THA patients. METHODS: /st>OI and the cardiovascular response to standing were evaluated with a standardized mobilization......BACKGROUND: /st>Early postoperative mobilization is a cornerstone in fast-track total hip arthroplasty (THA), but postoperative orthostatic intolerance (OI) may delay early recovery or lead to fainting, falls, and prosthesis dislocation or fracture. However, the prevalence and pathophysiology of OI...... protocol, before, 6, and 24 h after surgery in 26 patients undergoing THA with spinal anaesthesia and an opioid-sparing analgesic regime. Haemoglobin, fluid balance, and opioid use were recorded. Systolic (SAP) and diastolic (DAP) arterial pressure, heart rate (HR), stroke volume (SV), cardiac output (CO...

Fast Fourier transform telescope

International Nuclear Information System (INIS)

Tegmark, Max; Zaldarriaga, Matias

2009-01-01

We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of fast Fourier transforms recovers simultaneous multifrequency images of up to half the sky. Thanks to Moore's law, the bandwidth up to which this is feasible has now reached about 1 GHz, and will likely continue doubling every couple of years. The main advantages over a single dish telescope are cost and orders of magnitude larger field-of-view, translating into dramatically better sensitivity for large-area surveys. The key advantages over traditional interferometers are cost (the correlator computational cost for an N-element array scales as Nlog 2 N rather than N 2 ) and a compact synthesized beam. We argue that 21 cm tomography could be an ideal first application of a very large fast Fourier transform telescope, which would provide both massive sensitivity improvements per dollar and mitigate the off-beam point source foreground problem with its clean beam. Another potentially interesting application is cosmic microwave background polarization.

Commission of the European Communities review of fast reactor activities, March 1981

Energy Technology Data Exchange (ETDEWEB)

Balz, W [Commission of the European Communities, Brussels (Belgium)

1981-05-01

The Commission of the European Communities continued its activities in the field of fast reactors development essentially in the frame of the Fast Reactor Coordinating Committee (FRCC) and by execution of a Reactor Programme at its Joint Research Center (JRC). The study was concerned with introducing fast reactors into European Community, elaboration of preliminary safety criteria and guidelines for typical fast reactor accidents; codes and standards; LMFBR safety, fuel, fuel cycle safety.

Commission of the European Communities review of fast reactor activities, March 1981

International Nuclear Information System (INIS)

Balz, W.

1981-01-01

The Commission of the European Communities continued its activities in the field of fast reactors development essentially in the frame of the Fast Reactor Coordinating Committee (FRCC) and by execution of a Reactor Programme at its Joint Research Center (JRC). The study was concerned with introducing fast reactors into European Community, elaboration of preliminary safety criteria and guidelines for typical fast reactor accidents; codes and standards; LMFBR safety, fuel, fuel cycle safety

The behaviour of materials in fast reactors

International Nuclear Information System (INIS)

Matthews, J.R.

1977-01-01

Fast neutron damage in fast reactors can limit the life of structural components through the growth voids. The main features of the current theory of point defect production and condensation are surveyed. The role of metallurgical structures and radiation produced extended defects is outlined and used to demonstrate the development of volume swelling and radiation hardening. Mechanisms of radiation creep are described in the context of the preceding treatment of point defect behaviour. Finally, future trends in the field are briefly explored. (author)

An Electromagnet for Precession of the Polarization of Fast-Neutrons

International Nuclear Information System (INIS)

Aspesund, O.; Bjorkman, J.; Trumpy, G.

1965-05-01

The advantages of using a transverse magnetic field for precessing the polarization of fast-neutrons are discussed. Design details of a powerful electromagnet supplying a transverse field of approximately 20 kGauss are given. Precession characteristics for polarized fast neutrons obtained at 50 deg (lab. syst.) from the Li 7 (p, n) Be 7 reaction are reported, using elastic scattering at 42 deg (lab. syst.) off natural carbon as an analyser. Correlation of the precession data with theoretical predictions presented elsewhere is made, and good agreement is found

An Electromagnet for Precession of the Polarization of Fast-Neutrons

Energy Technology Data Exchange (ETDEWEB)

Aspesund, O; Bjorkman, J; Trumpy, G

1965-05-15

The advantages of using a transverse magnetic field for precessing the polarization of fast-neutrons are discussed. Design details of a powerful electromagnet supplying a transverse field of approximately 20 kGauss are given. Precession characteristics for polarized fast neutrons obtained at 50 deg (lab. syst.) from the Li{sup 7} (p, n) Be{sup 7} reaction are reported, using elastic scattering at 42 deg (lab. syst.) off natural carbon as an analyser. Correlation of the precession data with theoretical predictions presented elsewhere is made, and good agreement is found.

Balance Problems

Science.gov (United States)

... fully trust your sense of balance. Loss of balance also raises the risk of falls. This is a serious and even life-threatening ... 65. Balance disorders are serious because of the risk of falls. But occasionally balance problems may warn of another health condition, such ...

Glacier mass balance in high-arctic areas with anomalous gravity

Science.gov (United States)

Sharov, A.; Rieser, D.; Nikolskiy, D.

2012-04-01

All known glaciological models describing the evolution of Arctic land- and sea-ice masses in changing climate treat the Earth's gravity as horizontally constant, but it isn't. In the High Arctic, the strength of the gravitational field varies considerably across even short distances under the influence of a density gradient, and the magnitude of free air gravity anomalies attains 100 mGal and more. On long-term base, instantaneous deviations of gravity can have a noticeable effect on the regime and mass budget of glaciological objects. At best, the gravity-induced component of ice mass variations can be determined on topographically smooth, open and steady surfaces, like those of arctic planes, regular ice caps and landfast sea ice. The present research is devoted to studying gravity-driven impacts on glacier mass balance in the outer periphery of four Eurasian shelf seas with a very cold, dry climate and rather episodic character of winter precipitation. As main study objects we had chosen a dozen Russia's northernmost insular ice caps, tens to hundreds of square kilometres in extent, situated in a close vicinity of strong gravity anomalies and surrounded with extensive fields of fast and/or drift ice for most of the year. The supposition about gravitational forcing on glacioclimatic settings in the study region is based on the results of quantitative comparison and joint interpretation of existing glacier change maps and available data on the Arctic gravity field and solid precipitation. The overall mapping of medium-term (from decadal to half-centennial) changes in glacier volumes and quantification of mass balance characteristics in the study region was performed by comparing reference elevation models of study glaciers derived from Russian topographic maps 1:200,000 (CI = 20 or 40 m) representing the glacier state as in the 1950s-1980s with modern elevation data obtained from satellite radar interferometry and lidar altimetry. Free-air gravity anomalies were

Centralized and Distributed Solutions for Fast Muting Adaptation in LTE-Advanced HetNets

DEFF Research Database (Denmark)

Soret, Beatriz; Pedersen, Klaus I.

2015-01-01

Enhanced Intercell Interference Coordination (eICIC) is known to provide promising performance benefits for LTE-Advanced Heterogeneous Networks. The use of eICIC facilitates more flexible inter-layer load balancing by means of small cell Range Extension (RE) and Almost Blank Subframes (ABS). Even...... though the eICIC configuration (RE and ABS) ideally should be instantaneously adapted to follow the fluctuations of the traffic and the channel conditions over time, previous studies have focused on slow intercell coordination. In this paper, we investigate fast dynamic eICIC solutions for centralized....... Two different fast muting adaptation algorithms are derived, and it is shown how those can be appplied to both the centralized and the distributed architecture. Performance results with bursty traffic show that the fast dynamic adaptation provides significant gains, both in 5%-ile and 50%-ile user...

Effects of dynamic posturographic balance training versus conventional balance training on mobility and balance in elderly

International Nuclear Information System (INIS)

Saddiqi, F.A.; Masood, T.

2017-01-01

To determine the effects of dynamic posturographic balance training versus conventional balance training in improving mobility and balance in elderly. Methodology: Forty subjects between 50 to 80 years of age were selected via non-probability convenience sampling technique, for this randomized controlled trial. Both females and males with no major co-morbid conditions and cognitive impairments were recruited and randomized via coin toss method into two equal groups: Dynamic Posturographic balance training (DPG) group and Conventional balance training (CBT) group. The DPG training was provided via Biodex Balance System (Static and Dynamic). Both groups received interventions 3 times (35 to 45min each day) a week for 8 weeks, after which terminal assessment was done. Data were collected on demographic profile, balance via berg balance score and mobility by using Timed Up and Go Test. Independent samples t test was used to check difference between CBT group and DPG Group and repeated measures Analysis of Variance (ANOVA) was used for within-group analysis. Results: Baseline analysis of Berg balance scale and timed up and go test between two groups showed no significant difference with (p 0.805 and 0.251, respectively). After 8 weeks of intervention, there was significant difference between the groups in both variables (p 0.019 and 0.001, respectively). Conclusion: Dynamic posturographic balance training was more effective in improving dynamic balance and mobility in elderly population in comparison to conventional balance training. (author)

The Energy Balance of Plasma in a Coaxial Plasma Opening Switch

International Nuclear Information System (INIS)

Xu Xiang; Wang Younian

2006-01-01

The two-dimensional energy balance in a coaxial plasma opening switch (POS) is studied based on the single-fluid magnetohydrodynamic (MHD) equations coupled with the generalized Ohm's law. The energy transfers between the plasma and the magnetic field are considered during the penetration of the magnetic field as the Ohmic heating is included in the energy-balance equation. The focus is on the energy partition between the magnetic-field energy and the dissipated magnetic-field energy in a high-density POS with different rise-in-time electric currents at the generator boundary. The simulation code is tested in two cases: the constant-in-time current case and the linear rise-in-time current case. For the sinusoidally rise-in-time current similar to that of the experiments, it is shown that at the end of the conduction phase the dissipated magnetic-field energy is 36.5% of the input electromagnetic energy, which is consistent with the experimental results

Why fast magnetic reconnection is so prevalent

Science.gov (United States)

Boozer, Allen H.

2018-02-01

Evolving magnetic fields are shown to generically reach a state of fast magnetic reconnection in which magnetic field line connections change and magnetic energy is released at an Alfvénic rate. This occurs even in plasmas with zero resistivity; only the finiteness of the mass of the lightest charged particle, an electron, is required. The speed and prevalence of Alfvénic or fast magnetic reconnection imply that its cause must be contained within the ideal evolution equation for magnetic fields, , where is the velocity of the magnetic field lines. For a generic , neighbouring magnetic field lines develop a separation that increases exponentially, as \\unicode[STIX]{x1D70E(\\ell ,t)}$ with the distance along a line. This exponentially enhances the sensitivity of the evolution to non-ideal effects. An analogous effect, the importance of stirring to produce a large-scale flow and enhance mixing, has been recognized by cooks through many millennia, but the importance of the large-scale flow to reconnection is customarily ignored. In part this is due to the sixty-year focus of recognition theory on two-coordinate models, which eliminate the exponential enhancement that is generic with three coordinates. A simple three-coordinate model is developed, which could be used to address many unanswered questions.

Flipping the Metabolic Switch: Understanding and Applying Health Benefits of Fasting

Science.gov (United States)

Anton, Stephen D.; Moehl, Keelin; Donahoo, William T.; Marosi, Krisztina; Lee, Stephanie; Mainous, Arch G.; Leeuwenburgh, Christiaan; Mattson, Mark P.

2017-01-01

Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. Here we focus on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch – the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). Emerging findings suggest the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty-acid derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. Moreover, IF regimens also induce the coordinated activation of signaling pathways that optimize physiological function, enhance performance, and slow aging and disease processes. Future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and the magnitude of negative energy balance during the fasting period. PMID:29086496

Suppression of fast electron leakage from large openings in a plasma neutralizer for N-NB systems

International Nuclear Information System (INIS)

Kashiwagi, Mieko; Hanada, Masaya; Yamana, Takashi; Inoue, Takashi; Imai, Tsuyoshi; Taniguchi, Masaki; Watanabe, Kazuhiro

2006-01-01

To produce highly ionized plasmas at low operating pressure in a plasma neutralizer of negative ion based neutral beam (N-NB) systems, it is a critical issue to suppress leakage of fast electrons through large openings as the beam entrance/exit. The authors propose to form weak transverse magnetic fields without a significant beam deflection, called the shield field, across the large openings of the neutralizer. A numerical study showed that the shield field of only few tens of Gauss is sufficient to suppress the fast electron leakage from the openings. By measuring of an electron energy distribution function (EEDF), it was confirmed that such a weak magnetic field is enough to repel the fast electrons back into the neutralizer plasma. As the result, the plasma density increased with the shield field strength and saturated at 30 G. The plasma density reached 50% higher value than that without the shield field. Thus it was found that reflected fast electrons by the shield field of only 30 G work effectively for the plasma generation. It was also estimated that such a weak magnetic field sufficiently suppresses the deflection of a 1 MeV beam. This weak magnetic field would be applicable to the plasma neutralizer for the fusion demonstration (DEMO) plant

Three-dimensional core analysis on a super fast reactor with negative local void reactivity

International Nuclear Information System (INIS)

Cao Liangzhi; Oka, Yoshiaki; Ishiwatari, Yuki; Ikejiri, Satoshi

2009-01-01

Keeping negative void reactivity throughout the cycle life is one of the most important requirements for the design of a supercritical water-cooled fast reactor (super fast reactor). Previous conceptual design has negative overall void reactivity. But the local void reactivity, which is defined as the reactivity change when the coolant of one fuel assembly disappears, also needs to be kept negative throughout the cycle life because the super fast reactor is designed with closed fuel assemblies. The mechanism of the local void reactivity is theoretically analyzed from the neutrons balance point of view. Three-dimensional neutronics/thermal-hydraulic coupling calculation is employed to analyze the characteristics of the super fast reactor including the local void reactivity. Some configurations of the core are optimized to decrease the local void reactivity. A reference core is successfully designed with keeping both overall and local void reactivity negative. The maximum local void reactivity is less than -30 pcm

Short- and Long-Term Efficacy of Intensive Rehabilitation Treatment on Balance and Gait in Parkinsonian Patients: A Preliminary Study with a 1-Year Followup

Directory of Open Access Journals (Sweden)

Giuseppe Frazzitta

2013-01-01

Full Text Available Parkinson’s disease (PD is a neurodegenerative disease in which gait and balance disturbances are relevant symptoms that respond poorly to pharmacological treatment. The aim of this study was to investigate whether a 4-week inpatient multidisciplinary intensive rehabilitation treatment (MIRT is effective in improving balance and gait and whether improvements persist at a one-year followup. We studied 20 PD inpatients (stage 3 Hoehn-Yahr who underwent a MIRT. Outcome measures were UPDRS items for balance (30, falls (13, and walk (29, Berg Balance Scale, six-minute walking test, Timed Up and Go Test, and Comfortable-Fast gait speeds. Patients were evaluated at admission, at the end of the 4-week treatment, and at a 1-year followup. Pharmacological therapy was unchanged during MIRT and follow-up. All outcome measures improved significantly at the end of treatment. At 1-year follow-up control, UPDRS walk and Comfortable-Fast gait speeds still maintained better values with respect to admission (P=0.009, P=0.03, and P=0.02, resp., while the remaining scales did not differ significantly. Our results demonstrate that the MIRT was effective in improving balance and gait and that the improvement in gait performances was partially maintained also after 1 year.

The FAST (FRC Acceleration Space Thruster) Experiment

Science.gov (United States)

Martin, Adam; Eskridge, R.; Lee, M.; Richeson, J.; Smith, J.; Thio, Y. C. F.; Slough, J.; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

The Field Reverse Configuration (FRC) is a magnetized plasmoid that has been developed for use in magnetic confinement fusion. Several of its properties suggest that it may also be useful as a thruster for in-space propulsion. The FRC is a compact toroid that has only poloidal field, and is characterized by a high plasma beta = (P)/(B (sup 2) /2Mu0), the ratio of plasma pressure to magnetic field pressure, so that it makes efficient use of magnetic field to confine a plasma. In an FRC thruster, plasmoids would be repetitively formed and accelerated to high velocity; velocities of = 250 km/s (Isp = 25,000s) have already been achieved in fusion experiments. The FRC is inductively formed and accelerated, and so is not subject to the problem of electrode erosion. As the plasmoid may be accelerated over an extended length, it can in principle be made very efficient. And the achievable jet powers should be scalable to the MW range. A 10 kW thruster experiment - FAST (FRC Acceleration Space Thruster) has just started at the Marshall Space Flight Center. The design of FAST and the status of construction and operation will be presented.

Energy balance in TM-1-MH Tokamak (ohmical heating)

Science.gov (United States)

Stoeckel, J.; Koerbel, S.; Kryska, L.; Kopecky, V.; Dadalec, V.; Datlov, J.; Jakubka, K.; Magula, P.; Zacek, F.; Pereverzev, G. V.

1981-10-01

Plasma in the TM-1-MH Tokamak was experimentally studied in the parameter range: tor. mg. field B = 1,3 T, plasma current I sub p = 14 kA, electron density N sub E 3.10 to the 19th power cubic meters. The two numerical codes are available for the comparison with experimental data. TOKATA-code solves simplified energy balance equations for electron and ion components. TOKSAS-code solves the detailed energy balance of the ion component.

Prolonged fasting reduces IGF-1/PKA to promote hematopoietic-stem-cell-based regeneration and reverse immunosuppression.

Science.gov (United States)

Cheng, Chia-Wei; Adams, Gregor B; Perin, Laura; Wei, Min; Zhou, Xiaoying; Lam, Ben S; Da Sacco, Stefano; Mirisola, Mario; Quinn, David I; Dorff, Tanya B; Kopchick, John J; Longo, Valter D

2014-06-05

Immune system defects are at the center of aging and a range of diseases. Here, we show that prolonged fasting reduces circulating IGF-1 levels and PKA activity in various cell populations, leading to signal transduction changes in long-term hematopoietic stem cells (LT-HSCs) and niche cells that promote stress resistance, self-renewal, and lineage-balanced regeneration. Multiple cycles of fasting abated the immunosuppression and mortality caused by chemotherapy and reversed age-dependent myeloid-bias in mice, in agreement with preliminary data on the protection of lymphocytes from chemotoxicity in fasting patients. The proregenerative effects of fasting on stem cells were recapitulated by deficiencies in either IGF-1 or PKA and blunted by exogenous IGF-1. These findings link the reduced levels of IGF-1 caused by fasting to PKA signaling and establish their crucial role in regulating hematopoietic stem cell protection, self-renewal, and regeneration. Copyright © 2014 Elsevier Inc. All rights reserved.

BRIEF COMMUNICATION: Fast-ion redistribution due to sawtooth crash in the TEXTOR tokamak measured by collective Thomson scattering

Science.gov (United States)

Nielsen, S. K.; Bindslev, H.; Salewski, M.; Bürger, A.; Delabie, E.; Furtula, V.; Kantor, M.; Korsholm, S. B.; Leipold, F.; Meo, F.; Michelsen, P. K.; Moseev, D.; Oosterbeek, J. W.; Stejner, M.; Westerhof, E.; Woskov, P.; TEXTOR Team

2010-09-01

Here we present collective Thomson scattering measurements of 1D fast-ion velocity distribution functions in neutral beam heated TEXTOR plasmas with sawtooth oscillations. Up to 50% of the fast ions in the centre are redistributed as a consequence of a sawtooth crash. We resolve various directions to the magnetic field. The fast-ion distribution is found to be anisotropic as expected. For a resolved angle of 39° to the magnetic field we find a drop in the fast-ion distribution of 20-40%. For a resolved angle of 83° to the magnetic field the drop is no larger than 20%.

Triglyceride kinetics in fasted and fed E.coli septic rats

International Nuclear Information System (INIS)

Lanza-Jacoby, S.; Tabares, A.

1990-01-01

The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studies by examining the liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess the liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant intravenous infusion of [2- 3 H] glycerol-labeled VLDL in fasted control, fasted E. coli-treated, fed control, and fed E.coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 x 10 7 live E.coli colonies per 100 g body weight. Twenty-four hours following E.coli injection serum TG of fasted E.coli-treated rats was elevated by 170% which was attributed to a 67% decrease in the clearance rate of VLDL-TG in fasted E.coli-treated rats compared with their fasted controls. The secretion of VLDL-TG declined by 31% in the livers of the fasted E.coli-treated rats which was accompanied by a 2-fold increase in the composition of liver TG. In a second series of experiments control and E.coli-treated rats were fed intragastrically (IG) a balanced solution containing glucose plus fat as the sources of nonprotein calories. Serum TG were 26% lower in the fed E.coli-treated rats because the clearance rate increased by 86%. The secretion of TG in the fed septic rats increased by 40% but this difference was not significant. In the septic rat the ability to clear triglycerides from the plasma depends upon the nutritional state

Interchangeability of the Wii Balance Board for Bipedal Balance Assessment.

Science.gov (United States)

Bonnechère, Bruno; Jansen, Bart; Omelina, Lubos; Rooze, Marcel; Van Sint Jan, Serge

2015-08-27

Since 2010, an increasing interest in more portable and flexible hardware for balance and posture assessment led to previously published studies determining whether or not the Wii Balance Board could be used to assess balance and posture, both scientifically and clinically. However, no previous studies aimed at comparing results from different Wii Balance Boards for clinical balance evaluation exist. The objective of this crossover study is to assess the interchangeability of the Wii Balance Board. A total of 6 subjects participated in the study and their balance was assessed using 4 different Wii Balance Boards. Trials were recorded simultaneously with Wii Balance Boards and with a laboratory force plate. Nine relevant clinical parameters were derived from center of pressure displacement data obtained from Wii Balance Board and force plate systems. Intraclass correlation coefficients (ICC), F tests, and Friedman tests were computed to assess the agreement between trials and to compare the Wii Balance Board and force plate results. Excellent correlations were found between the Wii Balance Board and force plate (mean ρ =.83). With the exception of 2 parameters, strong to excellent agreements were found for the 7 remaining parameters (ICC=.96). No significant differences were found between trials recorded with different Wii Balance Boards. Our results indicate that for most of the parameters analyzed, balance and posture assessed with one Wii Balance Board were statistically similar to results obtained from another. Furthermore, the good correlation between the Wii Balance Board and force plate results shows that Wii Balance Boards can be reliably used for scientific assessment using most of the parameters analyzed in this study. These results also suggest that the Wii Balance Board could be used in multicenter studies and therefore, would allow for the creation of larger populations for clinical studies. Ethical Committee of the Erasme Hospital (CCB B406201215142

Epilepsy, E/I balance and GABAA receptor plasticity

Directory of Open Access Journals (Sweden)

Jean-Marc Fritschy

2008-03-01

Full Text Available GABAA receptors mediate most of the fast inhibitory transmission in the CNS. They form heteromeric complexes assembled from a large family of subunit genes. The existence of multiple GABAA receptor subtypes differing in subunit composition, localization and functional properties underlies their role for fi ne-tuning of neuronal circuits and genesis of network oscillations. The differential regulation of GABAA receptor subtypes represents a major facet of homeostatic synaptic plasticity and contributes to the excitation/inhibition (E/I balance under physiological conditions and upon pathological challenges. The purpose of this review is to discuss recent fi ndings highlighting the signifi cance of GABAA receptor heterogeneity for the concept of E/I balance and its relevance for epilepsy. Specifi cally, we address the following issues: (1 role for tonic inhibition, mediated by extrasynaptic GABAA receptors, for controlling neuronal excitability; (2 signifi cance of chloride ion transport for maintenance of the E/I balance in adult brain; and (3 molecular mechanisms underlying GABAA receptor regulation (traffi cking, posttranslational modifi cation, gene transcription that are important for homoeostatic plasticity. Finally, the relevance of these fi ndings is discussed in light of the involvement of GABAA receptors in epileptic disorders, based on recent experimental studies of temporal lobe epilepsy (TLE and absence seizures and on the identifi cation of mutations in GABAA receptor subunit genes underlying familial forms of epilepsy.

Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Annual report, March 1996--March 1997

Energy Technology Data Exchange (ETDEWEB)

Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Groshong, R.H.

1997-08-01

Gilbertown Field is the oldest oil field in Alabama and produces oil from chalk of the Upper Cretaceous Selma Group and from sandstone of the Eutaw Formation along the southern margin of the Gilbertown fault system. Most of the field has been in primary recovery since establishment, but production has declined to marginally economic levels. This investigation applies advanced geologic concepts designed to aid implementation of improved recovery programs. The Gilbertown fault system is detached at the base of Jurassic salt. The fault system began forming as a half graben and evolved in to a full graben by the Late Cretaceous. Conventional trapping mechanisms are effective in Eutaw sandstone, whereas oil in Selma chalk is trapped in faults and fault-related fractures. Burial modeling establishes that the subsidence history of the Gilbertown area is typical of extensional basins and includes a major component of sediment loading and compaction. Surface mapping and fracture analysis indicate that faults offset strata as young as Miocene and that joints may be related to regional uplift postdating fault movement. Preliminary balanced structural models of the Gilbertown fault system indicate that synsedimentary growth factors need to be incorporated into the basic equations of area balance to model strain and predict fractures in Selma and Eutaw reservoirs.

Balance equations for a viscous fluid from a Hamilton type variational principle

International Nuclear Information System (INIS)

Fierros Palacios, A.

1992-01-01

The partial differential field equations for any viscous fluid are obtained from the Lagrangian formalism as in classical field theory. An action functional is introduced as a space-time integral over a region of three-dimensional Euclidean space, of a Lagrangian density function of certain field variables. A Hamilton type extremum action principle is postulated with adequate boundary conditions, and a set of differential field equations is derived. With an appropriate Lagrangian density of the T-V type, the equation of motion for any viscous fluid is reproduced. A theorem referring to the invariance of the action under time variations lead to the generalized energy balance equation for the viscous fluid and to the energy balance equation proper. The same theoretical approach can be used to solve the problem of potential flow. (Author)

Risk of falls in older people during fast-walking--the TASCOG study.

Science.gov (United States)

Callisaya, M L; Blizzard, L; McGinley, J L; Srikanth, V K

2012-07-01

To investigate the relationship between fast-walking and falls in older people. Individuals aged 60-86 years were randomly selected from the electoral roll (n=176). Gait speed, step length, cadence and a walk ratio were recorded during preferred- and fast-walking using an instrumented walkway. Falls were recorded prospectively over 12 months. Log multinomial regression was used to estimate the relative risk of single and multiple falls associated with gait variables during fast-walking and change between preferred- and fast-walking. Covariates included age, sex, mood, physical activity, sensorimotor and cognitive measures. The risk of multiple falls was increased for those with a smaller walk ratio (shorter steps, faster cadence) during fast-walking (RR 0.92, CI 0.87, 0.97) and greater reduction in the walk ratio (smaller increase in step length, larger increase in cadence) when changing to fast-walking (RR 0.73, CI 0.63, 0.85). These gait patterns were associated with poorer physiological and cognitive function (prisk of multiple falls was also seen for those in the fastest quarter of gait speed (p=0.01) at fast-walking. A trend for better reaction time, balance, memory and physical activity for higher categories of gait speed was stronger for fallers than non-fallers (prisk of multiple falls. There may be two distinct groups at risk--the frail person with short shuffling steps, and the healthy person exposed to greater risk. Copyright © 2012 Elsevier B.V. All rights reserved.

Fast conjugate phase image reconstruction based on a Chebyshev approximation to correct for B0 field inhomogeneity and concomitant gradients.

Science.gov (United States)

Chen, Weitian; Sica, Christopher T; Meyer, Craig H

2008-11-01

Off-resonance effects can cause image blurring in spiral scanning and various forms of image degradation in other MRI methods. Off-resonance effects can be caused by both B0 inhomogeneity and concomitant gradient fields. Previously developed off-resonance correction methods focus on the correction of a single source of off-resonance. This work introduces a computationally efficient method of correcting for B0 inhomogeneity and concomitant gradients simultaneously. The method is a fast alternative to conjugate phase reconstruction, with the off-resonance phase term approximated by Chebyshev polynomials. The proposed algorithm is well suited for semiautomatic off-resonance correction, which works well even with an inaccurate or low-resolution field map. The proposed algorithm is demonstrated using phantom and in vivo data sets acquired by spiral scanning. Semiautomatic off-resonance correction alone is shown to provide a moderate amount of correction for concomitant gradient field effects, in addition to B0 imhomogeneity effects. However, better correction is provided by the proposed combined method. The best results were produced using the semiautomatic version of the proposed combined method.

Chance for balance: Chance for balance

OpenAIRE

Sævild, Katariina; Skov Sørensen, Katrine; Kildahl Lauritsen, Louise; Fuglsang, Sofie Olivia; Arnbjerg, Stine Høegh

2015-01-01

This project investigates how (im) balance between family and career influences Danish women's desire to have children. In order to answer this question, we have chosen to use qualitative method and our analysis is based on two semi-structured research interviews with two chosen women. Thus these women’s definition of balance and their view on children define the project. We have chosen to use of work-life balance theories, Thomas Hoejrup’s lifeform-analysis and Anthony Giddens’ theories of s...

THE NONLINEAR OHM'S LAW: PLASMA HEATING BY STRONG ELECTRIC FIELDS AND ITS EFFECTS ON THE IONIZATION BALANCE IN PROTOPLANETARY DISKS

Energy Technology Data Exchange (ETDEWEB)

Okuzumi, Satoshi [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Inutsuka, Shu-ichiro, E-mail: okuzumi@geo.titech.ac.jp [Department of Physics, Nagoya University, Nagoya, Aichi 464-8602 (Japan)

2015-02-10

The ionization state of the gas plays a key role in the magnetohydrodynamics (MHD) of protoplanetary disks. However, the ionization state can depend on the gas dynamics, because electric fields induced by MHD turbulence can heat up plasmas and thereby affect the ionization balance. To study this nonlinear feedback, we construct an ionization model that includes plasma heating by electric fields and impact ionization by heated electrons, as well as charging of dust grains. We show that when plasma sticking onto grains is the dominant recombination process, the electron abundance in the gas decreases with increasing electric field strength. This is a natural consequence of electron-grain collisions whose frequency increases with the electron's random velocity. The decreasing electron abundance may lead to a self-regulation of MHD turbulence. In some cases, not only the electron abundance but also the electric current decreases with increasing field strength in a certain field range. The resulting N-shaped current-field relation violates the fundamental assumption of the non-relativistic MHD that the electric field is uniquely determined by the current density. At even higher field strengths, impact ionization causes an abrupt increase of the electric current as expected by previous studies. We find that this discharge current is multi-valued (i.e., the current-field relation is S-shaped) under some circumstances, and that the intermediate branch is unstable. The N/S-shaped current-field relations may yield hysteresis in the evolution of MHD turbulence in some parts of protoplanetary disks.

Diagnosis of balanced and unbalanced motions in a synoptic-scale baroclinic wave life cycle

International Nuclear Information System (INIS)

Bush, A.B.G.; Peltier, W.R.; McWilliams, J.C.

1994-01-01

For numerical simulations of large scale dynamics, balanced models are attractive because their governing equations preclude gravity waves and one is thereby free to use a larger time step than is possible with a model governed by the primitive equations. Recent comparative studies have proven the so-called balance equations to be the most accurate of the intermediate models. In this particular study, a new set of balance equations is derived for a three-dimensional anelastic primitive equation simulation of a synoptic-scale baroclinic wave. Results indicate that both forms of imbalance. slow higher-order corrections and fast gravity wave motions, arise in the simulation. Investigations into the origin of these gravity waves reveal that the frontal slope near the time of occlusion decreases in the lower 2 kilometers to a value beyond compatability with the vertical and horizontal resolution employed, and we conclude that the waves are numerically generated

EVOLUTION OF FAST MAGNETOACOUSTIC PULSES IN RANDOMLY STRUCTURED CORONAL PLASMAS

International Nuclear Information System (INIS)

Yuan, D.; Li, B.; Pascoe, D. J.; Nakariakov, V. M.; Keppens, R.

2015-01-01

We investigate the evolution of fast magnetoacoustic pulses in randomly structured plasmas, in the context of large-scale propagating waves in the solar atmosphere. We perform one-dimensional numerical simulations of fast wave pulses propagating perpendicular to a constant magnetic field in a low-β plasma with a random density profile across the field. Both linear and nonlinear regimes are considered. We study how the evolution of the pulse amplitude and width depends on their initial values and the parameters of the random structuring. Acting as a dispersive medium, a randomly structured plasma causes amplitude attenuation and width broadening of the fast wave pulses. After the passage of the main pulse, secondary propagating and standing fast waves appear. Width evolution of both linear and nonlinear pulses can be well approximated by linear functions; however, narrow pulses may have zero or negative broadening. This arises because narrow pulses are prone to splitting, while broad pulses usually deviate less from their initial Gaussian shape and form ripple structures on top of the main pulse. Linear pulses decay at an almost constant rate, while nonlinear pulses decay exponentially. A pulse interacts most efficiently with a random medium with a correlation length of about half of the initial pulse width. This detailed model of fast wave pulses propagating in highly structured media substantiates the interpretation of EIT waves as fast magnetoacoustic waves. Evolution of a fast pulse provides us with a novel method to diagnose the sub-resolution filamentation of the solar atmosphere

Dynamic calibration and validation of an accelerometer force balance for hypersonic lifting models.

Science.gov (United States)

Singh, Prakash; Trivedi, Sharad; Menezes, Viren; Hosseini, Hamid

2014-01-01

An accelerometer-based force balance was designed and developed for the measurement of drag, lift, and rolling moment on a blunt-nosed, flapped delta wing in a short-duration hypersonic shock tunnel. Calibration and validation of the balance were carried out by a convolution technique using hammer pulse test and surface pressure measurements. In the hammer pulse test, a known impulse was applied to the model in the appropriate direction using an impulse hammer, and the corresponding output of the balance (acceleration) was recorded. Fast Fourier Transform (FFT) was operated on the output of the balance to generate a system response function, relating the signal output to the corresponding load input. Impulse response functions for three components of the balance, namely, axial, normal, and angular, were obtained for a range of input load. The angular system response function was corresponding to rolling of the model. The impulse response functions thus obtained, through dynamic calibration, were operated on the output (signals) of the balance under hypersonic aerodynamic loading conditions in the tunnel to get the time history of the unknown aerodynamic forces and moments acting on the model. Surface pressure measurements were carried out on the model using high frequency pressure transducers, and forces and moments were deduced thereon. Tests were carried out at model angles of incidence of 0, 5, 10, and 15 degrees. A good agreement was observed among the results of different experimental methods. The balance developed is a comprehensive force/moment measurement device that can be used on complex, lifting, aerodynamic geometries in ground-based hypersonic test facilities.

Calculation of local characteristics of velocity field in turbulent coolant flow in fast reactor fuel assembly

International Nuclear Information System (INIS)

Muehlbauer, P.

1981-08-01

Experience is described gained with the application of computer code VELASCO in calculating the velocity field in fast reactor fuel assemblies taking into account configuration disturbances due to fuel pin displacement. Theoretical results are compared with the results of experiments conducted by UJV on aerodynamic models HEM-1 (model of the fuel assembly central part) and HEM-2 (model of the fuel assembly peripheral part). The results are reported of calculating the distribution of shear stress in wetted rod surfaces and in the assembly wall (model HEM-2) and the corresponding experimental results are shown. The shear stress distribution in wetted surfaces obtained using the VELASCO code allowed forming an opinion on the code capability of comprising local parameters of turbulent flow through a fuel rod bundle. The applicability was also tested of the code for calculating mean velocities in the individual zones, eg., in elementary cells. (B.S.)

Fast electron transport in shaped solid targets

International Nuclear Information System (INIS)

Anle Lei; Cao, L.H.; He, X.T.; Zhang, W.Y.; Tanaka, K.A.; Kodama, R.; Mima, K.; Nakamura, T.; Normatsu, T.; Yu, W.

2010-01-01

Complete text of publication follows. The scheme of fast ignition fusion energy relies on the ultra-intense ultra-short (UIUS) laser energy transport into the compressed core plasma. One solution is to insert a hollow cone in the fuel shell to block the UIUS laser from the coronal plasma, thus allowing it to reach the core plasma. The cone not only can guide the UIUS laser to its tip, but can play important roles in the specific cone-in-shell target designed for FI. It was found in a PIC simulation that the cone can guide the fast electrons generated at the inner wall to propagate along the wall surface toward its tip, which would increase the energy density at the tip and might enhance the heating of the core plasma. Surface guiding of fast electrons with planar foil targets has been demonstrated experimentally. However, the guided fast electrons will mix the electrons generated ahead by the laser light with a planar target, and hence one cannot experimentally quantitatively validate the guide of the fast electrons. We investigate the cone guiding of fast electrons with an inverse cone target. We found a novel surface current of fast electrons propagating along the cone wall. The fast electrons generated at the planar outer tip of the inverse cone are guided and confined to propagate along the inverse cone wall to form a surface current by induced transient electric and magnetic fields associated with the current itself. Once departing from the source at the outer tip, this surface current of fast electrons is 'clean', neither experiencing the interacting laser light nor mixing fast electrons ahead, unlike those in cone or planar targets. This surface current in the inverse cone may explicitly give the capability of the guide of fast electron energy by the cone wall. The guiding and confinement of fast electrons is of important for fast ignition in inertial confinement fusion and several applications in high energy density science.

The relevance of clinical balance assessment tools to differentiate balance deficits

OpenAIRE

Mancini, Martina; Horak, Fay B

2010-01-01

Control of balance is complex and involves maintaining postures, facilitating movement, and recovering equilibrium. Balance control consists of controlling the body center of mass over its limits of stability. Clinical balance assessment can help assess fall risk and/or determine the underlying reasons for balance disorders. Most functional balance assessment scales assess fall risk and the need for balance rehabilitation but do not differentiate types of balance deficits. A system approach t...

Fast Multiscale Reservoir Simulations using POD-DEIM Model Reduction

KAUST Repository

Ghasemi, Mohammadreza

2015-02-23

In this paper, we present a global-local model reduction for fast multiscale reservoir simulations in highly heterogeneous porous media with applications to optimization and history matching. Our proposed approach identifies a low dimensional structure of the solution space. We introduce an auxiliary variable (the velocity field) in our model reduction that allows achieving a high degree of model reduction. The latter is due to the fact that the velocity field is conservative for any low-order reduced model in our framework. Because a typical global model reduction based on POD is a Galerkin finite element method, and thus it can not guarantee local mass conservation. This can be observed in numerical simulations that use finite volume based approaches. Discrete Empirical Interpolation Method (DEIM) is used to approximate the nonlinear functions of fine-grid functions in Newton iterations. This approach allows achieving the computational cost that is independent of the fine grid dimension. POD snapshots are inexpensively computed using local model reduction techniques based on Generalized Multiscale Finite Element Method (GMsFEM) which provides (1) a hierarchical approximation of snapshot vectors (2) adaptive computations by using coarse grids (3) inexpensive global POD operations in a small dimensional spaces on a coarse grid. By balancing the errors of the global and local reduced-order models, our new methodology can provide an error bound in simulations. Our numerical results, utilizing a two-phase immiscible flow, show a substantial speed-up and we compare our results to the standard POD-DEIM in finite volume setup.

Neighborhood fast food availability and fast food consumption.

Science.gov (United States)

Oexle, Nathalie; Barnes, Timothy L; Blake, Christine E; Bell, Bethany A; Liese, Angela D

2015-09-01

Recent nutritional and public health research has focused on how the availability of various types of food in a person's immediate area or neighborhood influences his or her food choices and eating habits. It has been theorized that people living in areas with a wealth of unhealthy fast-food options may show higher levels of fast-food consumption, a factor that often coincides with being overweight or obese. However, measuring food availability in a particular area is difficult to achieve consistently: there may be differences in the strict physical locations of food options as compared to how individuals perceive their personal food availability, and various studies may use either one or both of these measures. The aim of this study was to evaluate the association between weekly fast-food consumption and both a person's perceived availability of fast-food and an objective measure of fast-food presence - Geographic Information Systems (GIS) - within that person's neighborhood. A randomly selected population-based sample of eight counties in South Carolina was used to conduct a cross-sectional telephone survey assessing self-report fast-food consumption and perceived availability of fast food. GIS was used to determine the actual number of fast-food outlets within each participant's neighborhood. Using multinomial logistic regression analyses, we found that neither perceived availability nor GIS-based presence of fast-food was significantly associated with weekly fast-food consumption. Our findings indicate that availability might not be the dominant factor influencing fast-food consumption. We recommend using subjective availability measures and considering individual characteristics that could influence both perceived availability of fast food and its impact on fast-food consumption. If replicated, our findings suggest that interventions aimed at reducing fast-food consumption by limiting neighborhood fast-food availability might not be completely effective

Serum Lipid Profile: Fasting or Non-fasting?

OpenAIRE

Nigam, P. K.

2010-01-01

Serum lipid profile has now become almost a routine test. It is usually done in fasting state due to certain limitations in non-fasting serum sample. In the recent past efforts have been made to simplify blood sampling by replacing fasting lipid profile with non-fasting lipid profile. However, fasting specimen is preferred if cardiovascular risk assessment is based on total cholesterol, LDL cholesterol or non-HDL cholesterol. A lot has yet to be done in this area. Till then we have to believe...

Considerations on 'Harmonic balancing approach to nonlinear oscillations of a punctual charge in the electric field of charged ring'

International Nuclear Information System (INIS)

Belendez, A.; Fernandez, E.; Rodes, J.J.; Fuentes, R.; Pascual, I.

2009-01-01

In a previous short communication [A. Belendez, E. Fernandez, J.J. Rodes, R. Fuentes, I. Pascual, Phys. Lett. A 373 (2009) 735] the nonlinear oscillations of a punctual charge in the electric field of a charged ring were analyzed. Approximate frequency-amplitude relations and periodic solutions were obtained using the harmonic balance method. Now we clarify an important aspect about of this oscillation charge. Taking into account Earnshaw's theorem, this punctual charge cannot be a free charge and so it must be confined, for example, on a finite conducting wire placed along the axis of the ring. Then, the oscillatory system may consist of a punctual charge on a conducting wire placed along the axis of the uniformly charged ring.

Balance Problems

Science.gov (United States)

... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

Fast delta Hadamard transform