Effect of chronic hypoxia on the capillarity of dog skeletal muscle

NASA Astrophysics Data System (ADS)

Sillau, A. H.

1980-12-01

Capillarity and fiber composition were studied by the ATPase technique in frozen samples of sternothyroid muscle of dogs from sea level (SL) and high altitude (3,300 4,300 m) (HA). Capillary density (CD), capillary to fiber ratio (C:F) and fiber cross sectional area (FCSA) were measured. The mean CD was 791/mm2 at SL and 743/mm2 at HA. CD was linearly related to FCSA in the SL animals (CD=1112.8 0.10 FCSA; r=-0.63). In both SL and HA animals, C:F was linearly and positively correlated with FCSA. There was no significant difference between the two regression lines; therefore, only one line represents all the data (C:F=0.78+(5.19×10-4) FCSA; r=0.77). Thus, at a given FCSA the C:F was the same for SL and HA dogs. Two types of fibers were identified: type I (slow twitch) (42%) and type II (fast twitch) (58%). No differences in fiber composition or FCSA were observed between the SL and HA dogs. These results indicate that moderate levels of hypoxia do not affect the capillarity of dog skeletal muscle.

Vanishing Point Extraction and Refinement for Robust Camera Calibration

PubMed Central

Tsai, Fuan

2017-01-01

This paper describes a flexible camera calibration method using refined vanishing points without prior information. Vanishing points are estimated from human-made features like parallel lines and repeated patterns. With the vanishing points extracted from the three mutually orthogonal directions, the interior and exterior orientation parameters can be further calculated using collinearity condition equations. A vanishing point refinement process is proposed to reduce the uncertainty caused by vanishing point localization errors. The fine-tuning algorithm is based on the divergence of grouped feature points projected onto the reference plane, minimizing the standard deviation of each of the grouped collinear points with an O(1) computational complexity. This paper also presents an automated vanishing point estimation approach based on the cascade Hough transform. The experiment results indicate that the vanishing point refinement process can significantly improve camera calibration parameters and the root mean square error (RMSE) of the constructed 3D model can be reduced by about 30%. PMID:29280966

Microfluidic Capillaric Circuit for Rapid and Facile Bacteria Detection.

PubMed

Olanrewaju, Ayokunle Oluwafemi; Ng, Andy; DeCorwin-Martin, Philippe; Robillard, Alessandra; Juncker, David

2017-06-20

Urinary tract infections (UTI) are one of the most common bacterial infections and would greatly benefit from a rapid point-of-care diagnostic test. Although significant progress has been made in developing microfluidic systems for nucleic acid and whole bacteria immunoassay tests, their practical application is limited by complex protocols, bulky peripherals, and slow operation. Here we present a microfluidic capillaric circuit (CC) optimized for rapid and automated detection of bacteria in urine. Molds for CCs were constructed using previously established design rules, then 3D-printed and replicated into poly(dimethylsiloxane). CCs autonomously and sequentially performed all liquid delivery steps required for the assay. For efficient bacteria capture, on-the-spot packing of antibody-functionalized microbeads was completed in <20 s followed by autonomous sequential delivery of 100 μL of bacteria sample, biotinylated detection antibodies, fluorescent streptavidin conjugate, and wash buffer for a total volume ≈115 μL. The assay was completed in <7 min. Fluorescence images of the microbead column revealed captured bacteria as bright spots that were easily counted manually or using an automated script for user-independent assay readout. The limit of detection of E. coli in synthetic urine was 1.2 × 10 2 colony-forming-units per mL (CFU/mL), which is well below the clinical diagnostic criterion (>10 5 CFU/mL) for UTI. The self-powered, peripheral-free CC presented here has potential for use in rapid point-of-care UTI screening.

Capillarity, oxidative capacity and fibre composition of the soleus and gastrocnemius muscles of rats in hypothyroidism.

PubMed Central

Sillau, A H

1985-01-01

Muscle capillarity, mean and maximal diffusion distances and muscle fibre composition were evaluated in frozen sections stained for myosin ATPase of the soleus and the white area of the gastrocnemius medial head (gastrocnemius) of rats made hypothyroid by the injection of propylthiouracil (PTU) (50 mg kg-1) every day for 21 or 42 days. Oxygen consumption in the presence of excess ADP and Pi with pyruvate plus malate as substrates and the activity of cytochrome c oxidase were measured in muscle homogenates. Treatment with PTU decreased body oxygen consumption and the concentration of triiodothyronine in plasma. The capacity of the soleus and gastrocnemius muscles' homogenates to oxidize pyruvate plus malate and their cytochrome c oxidase activity were reduced after 21 or 42 days of treatment with PTU. Fibre composition in the soleus muscle was changed by treatment with PTU. There was a decrease in the proportion of type IIa or fast glycolytic oxidative fibres and an increase in type I or slow oxidative fibres. After 21 days of PTU administration there was also an increase in the proportion of fibres classified as IIc. The changes in fibre composition are believed to be the result of changes in the types of myosin synthesized by the fibres. Therefore, the fibres classified as IIc are, most probably, IIa fibres in the process of changing their myosin to that of the type I fibres. No changes in fibre composition were evident in the white area of the gastrocnemius medial head, an area made up of IIb or fast glycolytic fibres. The indices of capillarity: capillary density and capillary to fibre ratio, as well as mean and maximal diffusion distances from the capillaries, were not changed by the treatment with PTU in the muscles studied. The lack of changes in capillarity in spite of significant changes in oxidative capacity indicates that in skeletal muscle capillarity is not necessarily related to the oxidative capacity of the fibres. PMID:3989729

The Vanishing Latino Male in Higher Education

ERIC Educational Resources Information Center

Saenz, Victor B.; Ponjuan, Luis

2009-01-01

Latino male students are "vanishing" from the American education pipeline, a trend that is especially evident at the secondary and postsecondary levels. The question of why Latino males are vanishing from America's colleges is complex, and this scholarly article explores some of the socio-cultural factors, peer dynamics, and labor force demands…

Hand-Held Femtogram Detection of Hazardous Picric Acid with Hydrophobic Ag Nanopillar SERS Substrates and Mechanism of Elasto-Capillarity.

PubMed

Hakonen, Aron; Wang, FengChao; Andersson, Per Ola; Wingfors, Håkan; Rindzevicius, Tomas; Schmidt, Michael Stenbæk; Soma, Venugopal Rao; Xu, Shicai; Li, YingQi; Boisen, Anja; Wu, HengAn

2017-02-24

Picric acid (PA) is a severe environmental and security risk due to its unstable, toxic, and explosive properties. It is also challenging to detect in trace amounts and in situ because of its highly acidic and anionic character. Here, we assess sensing of PA under nonlaboratory conditions using surface-enhanced Raman scattering (SERS) silver nanopillar substrates and hand-held Raman spectroscopy equipment. The advancing elasto-capillarity effects are explained by molecular dynamics simulations. We obtain a SERS PA detection limit on the order of 20 ppt, corresponding attomole amounts, which together with the simple analysis methodology demonstrates that the presented approach is highly competitive for ultrasensitive analysis in the field.

Capillarics: pre-programmed, self-powered microfluidic circuits built from capillary elements.

PubMed

Safavieh, Roozbeh; Juncker, David

2013-11-07

Microfluidic capillary systems employ surface tension effects to manipulate liquids, and are thus self-powered and self-regulated as liquid handling is structurally and chemically encoded in microscale conduits. However, capillary systems have been limited to perform simple fluidic operations. Here, we introduce complex capillary flow circuits that encode sequential flow of multiple liquids with distinct flow rates and flow reversal. We first introduce two novel microfluidic capillary elements including (i) retention burst valves and (ii) robust low aspect ratio trigger valves. These elements are combined with flow resistors, capillary retention valves, capillary pumps, and open and closed reservoirs to build a capillary circuit that, following sample addition, autonomously delivers a defined sequence of multiple chemicals according to a preprogrammed and predetermined flow rate and time. Such a circuit was used to measure the concentration of C-reactive protein. This work illustrates that as in electronics, complex capillary circuits may be built by combining simple capillary elements. We define such circuits as "capillarics", and introduce symbolic representations. We believe that more complex circuits will become possible by expanding the library of building elements and formulating abstract design rules.

Electromagnetic liquid pistons for capillarity-based pumping

NASA Astrophysics Data System (ADS)

Malouin, Bernard; Olles, Joseph; Cheng, Lili; Hirsa, Amir; Vogel, Michael

2011-11-01

Two adjoining ferrofluid droplets can behave as an electronically-controlled oscillator or switch by an appropriate balance of magnetic, capillary, and inertial forces. Their motion can be exploited to displace a surrounding liquid, forming electromagnetic liquid pistons. Such ferrofluid pistons can pump a precise volume of liquid via finely tunable amplitudes or resonant frequencies with no solid moving parts. Here we demonstrate the use of these liquid pistons in capillarity-dominated systems for variable focal distance liquid lenses with nearly perfect spherical interfaces. These liquid/liquid lenses feature many promising qualities not previously realized together in a liquid lens, including large apertures, immunity to evaporation, invariance to orientation relative to gravity, and low driving voltages. The dynamics of these liquid pistons is examined, with experimental measurements showing good agreement with a spherical cap model. A centimeter-scale lens was shown to respond in excess of 30 Hz, with resonant frequencies over 1 kHz predicted for scaled down systems.

Muscle fibre capillarization is a critical factor in muscle fibre hypertrophy during resistance exercise training in older men.

PubMed

Snijders, Tim; Nederveen, Joshua P; Joanisse, Sophie; Leenders, Marika; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

2017-04-01

Adequate muscle fibre perfusion is critical for the maintenance of muscle mass; it is essential in the rapid delivery of oxygen, nutrients and growth factors to the muscle, stimulating muscle fibre growth. Muscle fibre capillarization is known to decrease substantially with advancing age. However, whether (relative) low muscle fibre capillarization negatively impacts the muscle hypertrophic response following resistance exercise training in older adults is unknown. Twenty-two healthy older men (71 ± 1 years) performed 24 weeks of progressive resistance type exercise training. To assess the change in muscle fibre characteristics, percutaneous biopsies from the vastus lateralis muscle were taken before and following 12 and 24 weeks of the intervention programme. A comparison was made between participants who had a relatively low type II muscle fibre capillary-to-fibre perimeter exchange index (CFPE; LOW group) and high type II muscle fibre CFPE (HIGH group) at baseline. Type I and type II muscle fibre size, satellite cell, capillary content and distance between satellite cells to the nearest capillary were determined by immunohistochemistry. Overall, type II muscle fibre size (from 5150 ± 234 to 6719 ± 446 µm 2 , P < 0.05) and satellite cell content (from 0.058 ± 0.006 to 0.090 ± 0.010 satellite cells per muscle fibre, P < 0.05) had increased significantly in response to 24 weeks of resistance exercise training. However, these improvements where mainly driven by differences in baseline type II muscle fibre capillarization, whereas muscle fibre size (from 5170 ± 390 to 7133 ± 314 µm 2 , P < 0.05) and satellite cell content (from 0.059 ± 0.009 to 0.102 ± 0.017 satellite cells per muscle fibre, P < 0.05) increased significantly in the HIGH group, no significant changes were observed in LOW group following exercise training. No significant changes in type I and type II muscle fibre capillarization

Enhancement of multiple cranial and spinal nerves in vanishing white matter: expanding the differential diagnosis.

PubMed

Eluvathingal Muttikkal, Thomas Jose; Montealegre, Denia Ramirez; Matsumoto, Julie Ann

2018-03-01

Abnormal cranial or spinal nerve contrast enhancement on MRI in cases of suspected pediatric leukodystrophy is recognized as an important clue to the diagnosis of either metachromatic leukodystrophy or globoid cell leukodystrophy (Krabbe disease). We report a case of genetically confirmed childhood vanishing white matter with enhancement of multiple cranial and spinal nerves in addition to the more typical intracranial findings. This case expands the limited differential diagnosis of cranial nerve or spinal nerve enhancement in cases of suspected leukodystrophy and may aid in more efficient work-up and earlier diagnosis of vanishing white matter.

Natural occupation numbers: when do they vanish?

PubMed

Giesbertz, K J H; van Leeuwen, R

2013-09-14

The non-vanishing of the natural orbital (NO) occupation numbers of the one-particle density matrix of many-body systems has important consequences for the existence of a density matrix-potential mapping for nonlocal potentials in reduced density matrix functional theory and for the validity of the extended Koopmans' theorem. On the basis of Weyl's theorem we give a connection between the differentiability properties of the ground state wavefunction and the rate at which the natural occupations approach zero when ordered as a descending series. We show, in particular, that the presence of a Coulomb cusp in the wavefunction leads, in general, to a power law decay of the natural occupations, whereas infinitely differentiable wavefunctions typically have natural occupations that decay exponentially. We analyze for a number of explicit examples of two-particle systems that in case the wavefunction is non-analytic at its spatial diagonal (for instance, due to the presence of a Coulomb cusp) the natural orbital occupations are non-vanishing. We further derive a more general criterium for the non-vanishing of NO occupations for two-particle wavefunctions with a certain separability structure. On the basis of this criterium we show that for a two-particle system of harmonically confined electrons with a Coulombic interaction (the so-called Hookium) the natural orbital occupations never vanish.

Phase-contrast CT: Qualitative and Quantitative Evaluation of Capillarized Sinusoids and Trabecular Structure in Human Hepatocellular Carcinoma Tissues.

PubMed

Jian, Jianbo; Zhang, Wenxue; Yang, Hao; Zhao, Xinyan; Xuan, Ruijiao; Li, Dongyue; Hu, Chunhong

2017-01-01

Capillarization of sinusoids and change of trabecular thickness are the main histologic features in hepatocellular carcinoma (HCC). Of particular interest are the three-dimensional (3D) visualization and quantitative evaluation of such alterations in the HCC progression. X-ray phase-contrast computed tomography (PCCT) is an emerging imaging method that provides excellent image contrast for soft tissues. This study aimed to explore the potential of in-line PCCT in microstructure imaging of capillarized sinusoids and trabecular structure in human HCC tissues and to quantitatively evaluate the alterations of those fine structures during the development of HCC. This project was designed as an ex vivo experimental study. The study was approved by the institutional review board, and informed consent was obtained from the patients. Eight human resected HCC tissue samples were imaged using in-line PCCT. After histologic processing, PCCT images and histopathologic data were matched. Fine structures in HCC tissues were revealed. Quantitative analyses of capillarized sinusoids (ie, percentage of sinusoidal area [PSA], sinusoidal volume) and trabecular structure (ie, trabecular thickness, surface-area-to-volume ratio [SA/V]) in low-grade (well or moderately differentiated) and high-grade (poorly differentiated) HCC groups were performed. Using PCCT, the alterations of capillarized sinusoids and trabecular structure were clearly observed in 3D geometry, which was confirmed by the corresponding histologic sections. The 3D qualitative analyses of sinusoids in the high-grade HCC group were significantly different (P < 0.05) in PSA (7.8 ± 2.5%) and sinusoidal volume (2.9 ± 0.6 × 10 7  µm 3 ) from those in the low-grade HCC group (PSA, 12.9 ± 2.2%; sinusoidal volume, 2.4 ± 0.3 × 10 7  µm 3 ). Moreover, the 3D quantitative evaluation of the trabecular structure in the high-grade HCC group showed a significant change (P < 0.05) in the

The Bragg gap vanishing phenomena in one-dimensional photonic crystals.

PubMed

Zhang, Hui; Chen, Xi; Li, Youquan; Fu, Yunqi; Yuan, Naichang

2009-05-11

We theoretically deduce the Bragg gap vanishing conditions in one-dimensional photonic crystals and experimentally demonstrate the m=0 band-gap vanishing phenomena at microwave frequencies. In the case of mismatched impedance, the Bragg gap will vanish as long as the discrete modes appear in photonic crystals containing dispersive materials, while for the matched impedance cases, Bragg gaps will always disappear. The experimental results and the simulations agree extremely well with the theoretical expectation.

Error Distribution Evaluation of the Third Vanishing Point Based on Random Statistical Simulation

NASA Astrophysics Data System (ADS)

Li, C.

2012-07-01

POS, integrated by GPS / INS (Inertial Navigation Systems), has allowed rapid and accurate determination of position and attitude of remote sensing equipment for MMS (Mobile Mapping Systems). However, not only does INS have system error, but also it is very expensive. Therefore, in this paper error distributions of vanishing points are studied and tested in order to substitute INS for MMS in some special land-based scene, such as ground façade where usually only two vanishing points can be detected. Thus, the traditional calibration approach based on three orthogonal vanishing points is being challenged. In this article, firstly, the line clusters, which parallel to each others in object space and correspond to the vanishing points, are detected based on RANSAC (Random Sample Consensus) and parallelism geometric constraint. Secondly, condition adjustment with parameters is utilized to estimate nonlinear error equations of two vanishing points (VX, VY). How to set initial weights for the adjustment solution of single image vanishing points is presented. Solving vanishing points and estimating their error distributions base on iteration method with variable weights, co-factor matrix and error ellipse theory. Thirdly, under the condition of known error ellipses of two vanishing points (VX, VY) and on the basis of the triangle geometric relationship of three vanishing points, the error distribution of the third vanishing point (VZ) is calculated and evaluated by random statistical simulation with ignoring camera distortion. Moreover, Monte Carlo methods utilized for random statistical estimation are presented. Finally, experimental results of vanishing points coordinate and their error distributions are shown and analyzed.

When Dijkstra Meets Vanishing Point: A Stereo Vision Approach for Road Detection.

PubMed

Zhang, Yigong; Su, Yingna; Yang, Jian; Ponce, Jean; Kong, Hui

2018-05-01

In this paper, we propose a vanishing-point constrained Dijkstra road model for road detection in a stereo-vision paradigm. First, the stereo-camera is used to generate the u- and v-disparity maps of road image, from which the horizon can be extracted. With the horizon and ground region constraints, we can robustly locate the vanishing point of road region. Second, a weighted graph is constructed using all pixels of the image, and the detected vanishing point is treated as the source node of the graph. By computing a vanishing-point constrained Dijkstra minimum-cost map, where both disparity and gradient of gray image are used to calculate cost between two neighbor pixels, the problem of detecting road borders in image is transformed into that of finding two shortest paths that originate from the vanishing point to two pixels in the last row of image. The proposed approach has been implemented and tested over 2600 grayscale images of different road scenes in the KITTI data set. The experimental results demonstrate that this training-free approach can detect horizon, vanishing point, and road regions very accurately and robustly. It can achieve promising performance.

Capillarity-induced folds fuel extreme shape changes in thin wicked membranes.

PubMed

Grandgeorge, Paul; Krins, Natacha; Hourlier-Fargette, Aurélie; Laberty-Robert, Christel; Neukirch, Sébastien; Antkowiak, Arnaud

2018-04-20

Soft deformable materials are needed for applications such as stretchable electronics, smart textiles, or soft biomedical devices. However, the design of a durable, cost-effective, or biologically compatible version of such a material remains challenging. Living animal cells routinely cope with extreme deformations by unfolding preformed membrane reservoirs available in the form of microvilli or membrane folds. We synthetically mimicked this behavior by creating nanofibrous liquid-infused tissues that spontaneously form similar reservoirs through capillarity-induced folding. By understanding the physics of membrane buckling within the liquid film, we developed proof-of-concept conformable chemical surface treatments and stretchable basic electronic circuits. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

On the vanishing couplings in ADE affine Toda field theories

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

Saitoh, Y.; Shimada, T.

In this paper, the authors show that certain vanishing couplins in the ADE affine Toda field theories remain vanishing even after higher-order corrections are included. This is a requisite property for the Lagrangian formulation of the theory. The authors develop a new perturbative formulation and treat affine Toda field theories as a massless theory with exponential interaction terms. The authors shown that the nonrenormalization comes from the Dynkin automorphism of the Lie algebra associated with these theories. A charge balance conditions plays an important role in our scheme. The all-order nonrenormalization of vanishing couplings in [bar A][sub n] affine Todamore » field theory is also proved in a standard massive scheme.« less

Vanishing White Matter Disease: A Review with Focus on Its Genetics

ERIC Educational Resources Information Center

Pronk, Jan C.; van Kollenburg, Barbara; Scheper, Gert C.; van der Knaap, Marjo S.

2006-01-01

Leukoencephalopathy with vanishing white matter (VWM) is an autosomal recessive brain disorder, most often with a childhood onset. Magnetic resonance imaging and spectroscopy indicate that, with time, increasing amounts of cerebral white matter vanish and are replaced by fluid. Autopsy confirms white matter rarefaction and cystic degeneration. The…

Vanishing points detection using combination of fast Hough transform and deep learning

NASA Astrophysics Data System (ADS)

Sheshkus, Alexander; Ingacheva, Anastasia; Nikolaev, Dmitry

2018-04-01

In this paper we propose a novel method for vanishing points detection based on convolutional neural network (CNN) approach and fast Hough transform algorithm. We show how to determine fast Hough transform neural network layer and how to use it in order to increase usability of the neural network approach to the vanishing point detection task. Our algorithm includes CNN with consequence of convolutional and fast Hough transform layers. We are building estimator for distribution of possible vanishing points in the image. This distribution can be used to find candidates of vanishing point. We provide experimental results from tests of suggested method using images collected from videos of road trips. Our approach shows stable result on test images with different projective distortions and noise. Described approach can be effectively implemented for mobile GPU and CPU.

Axonal abnormalities in vanishing white matter.

PubMed

Klok, Melanie D; Bugiani, Marianna; de Vries, Sharon I; Gerritsen, Wouter; Breur, Marjolein; van der Sluis, Sophie; Heine, Vivi M; Kole, Maarten H P; Baron, Wia; van der Knaap, Marjo S

2018-04-01

We aimed to study the occurrence and development of axonal pathology and the influence of astrocytes in vanishing white matter. Axons and myelin were analyzed using electron microscopy and immunohistochemistry on Eif2b4 and Eif2b5 single- and double-mutant mice and patient brain tissue. In addition, astrocyte-forebrain co-culture studies were performed. In the corpus callosum of Eif2b5- mutant mice, myelin sheath thickness, axonal diameter, and G-ratio developed normally up to 4 months. At 7 months, however, axons had become thinner, while in control mice axonal diameters had increased further. Myelin sheath thickness remained close to normal, resulting in an abnormally low G-ratio in Eif2b5- mutant mice. In more severely affected Eif2b4-Eif2b5 double-mutants, similar abnormalities were already present at 4 months, while in milder affected Eif2b4 mutants, few abnormalities were observed at 7 months. Additionally, from 2 months onward an increased percentage of thin, unmyelinated axons and increased axonal density were present in Eif2b5 -mutant mice. Co-cultures showed that Eif2b5 mutant astrocytes induced increased axonal density, also in control forebrain tissue, and that control astrocytes induced normal axonal density, also in mutant forebrain tissue. In vanishing white matter patient brains, axons and myelin sheaths were thinner than normal in moderately and severely affected white matter. In mutant mice and patients, signs of axonal transport defects and cytoskeletal abnormalities were minimal. In vanishing white matter, axons are initially normal and atrophy later. Astrocytes are central in this process. If therapy becomes available, axonal pathology may be prevented with early intervention.

Role of hemoglobin and capillarization for oxygen delivery and extraction in muscular exercise.

PubMed

Saltin, B; Kiens, B; Savard, G; Pedersen, P K

1986-01-01

Through the years the role of the various links in the transport of oxygen in the human body has been discussed extensively, and especially whether one of these links could be singled out as limiting oxygen uptake during exercise. In his thesis work Lars Hermansen dealt with several of these variables related to oxygen transport and uptake. Two of these were the hemoglobin concentration of the blood (Hb) and skeletal muscle capillarization. These are the focus of this article. It can be demonstrated that variation in arterial oxygen content due to different Hb concentrations is fully compensated for at the level of the muscle, i.e. the amount of oxygen delivered to contracting muscles is adjusted by a variation in the blood flow so that it is the same regardless of Hb concentration in the range of 118-172 g X l-1. At the systemic level, with a large fraction of the muscle exercising, this causes an increase in submaximal heart rate and a lowering in maximal oxygen uptake in people with low as compared to normal or high Hb concentration. The primary significance of an enlarged capillary network in the muscle does not appear to be for accommodating a larger flow, but rather to allow for a long enough mean transit time and large enough surface area for optimal exchange of gases, substrates and metabolites.

Asymptotically Vanishing Cosmological Constant in the Multiverse

NASA Astrophysics Data System (ADS)

Kawai, Hikaru; Okada, Takashi

We study the problem of the cosmological constant in the context of the multiverse in Lorentzian space-time, and show that the cosmological constant will vanish in the future. This sort of argument was started by Sidney Coleman in 1989, and he argued that the Euclidean wormholes make the multiverse partition function a superposition of various values of the cosmological constant Λ, which has a sharp peak at Λ = 0. However, the implication of the Euclidean analysis to our Lorentzian space-time is unclear. With this motivation, we analyze the quantum state of the multiverse in Lorentzian space-time by the WKB method, and calculate the density matrix of our universe by tracing out the other universes. Our result predicts vanishing cosmological constant. While Coleman obtained the enhancement at Λ = 0 through the action itself, in our Lorentzian analysis the similar enhancement arises from the front factor of eiS in the universe wave function, which is in the next leading order in the WKB approximation.

Selective separation of oil and water with mesh membranes by capillarity.

PubMed

Yu, Yuanlie; Chen, Hua; Liu, Yun; Craig, Vincent S J; Lai, Zhiping

2016-09-01

The separation of oil and water from wastewater generated in the oil-production industries, as well as in frequent oil spillage events, is important in mitigating severe environmental and ecological damage. Additionally, a wide arrange of industrial processes require oils or fats to be removed from aqueous systems. The immiscibility of oil and water allows for the wettability of solid surfaces to be engineered to achieve the separation of oil and water through capillarity. Mesh membranes with extreme, selective wettability can efficiently remove oil or water from oil/water mixtures through a simple filtration process using gravity. A wide range of different types of mesh membranes have been successfully rendered with extreme wettability and applied to oil/water separation in the laboratory. These mesh materials have typically shown good durability, stability as well as reusability, which makes them promising candidates for an ever widening range of practical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

The Vanishing Black Family: Myth or Reality?

ERIC Educational Resources Information Center

Banks, Ivan W.

Recent media reports have characterized the black family as vanishing and being replaced by institutionalized chaos, indifference, and "benign neglect." Journalists point to the high rate of teen pregnancies and the increased proportions of black families headed by single women, and describe black men as having little regard for the role of…

Vanishing spin stiffness in the spin-1/2 Heisenberg chain for any nonzero temperature

NASA Astrophysics Data System (ADS)

Carmelo, J. M. P.; Prosen, T.; Campbell, D. K.

2015-10-01

Whether at the zero spin density m =0 and finite temperatures T >0 the spin stiffness of the spin-1 /2 X X X chain is finite or vanishes remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we explicitly compute the stiffness at m =0 and find strong evidence that it vanishes. In particular, we derive an upper bound on the stiffness within a canonical ensemble at any fixed value of spin density m that is proportional to m2L in the thermodynamic limit of chain length L →∞ , for any finite, nonzero temperature, which implies the absence of ballistic transport for T >0 for m =0 . Although our method relies in part on the thermodynamic Bethe ansatz (TBA), it does not evaluate the stiffness through the second derivative of the TBA energy eigenvalues relative to a uniform vector potential. Moreover, we provide strong evidence that in the thermodynamic limit the upper bounds on the spin current and stiffness used in our derivation remain valid under string deviations. Our results also provide strong evidence that in the thermodynamic limit the TBA method used by X. Zotos [Phys. Rev. Lett. 82, 1764 (1999), 10.1103/PhysRevLett.82.1764] leads to the exact stiffness values at finite temperature T >0 for models whose stiffness is finite at T =0 , similar to the spin stiffness of the spin-1 /2 Heisenberg chain but unlike the charge stiffness of the half-filled 1D Hubbard model.

Slope and curvature of the hadronic vacuum polarization at vanishing virtuality from lattice QCD

NASA Astrophysics Data System (ADS)

Borsanyi, Sz.; Fodor, Z.; Kawanai, T.; Krieg, S.; Lellouch, L.; Malak, R.; Miura, K.; Szabo, K. K.; Torrero, C.; Toth, B. C.

2017-10-01

We compute the slope and curvature, at vanishing four-momentum transfer squared, of the leading order hadronic vacuum polarization function, using lattice quantum chromodynamics. Calculations are performed with 2 +1 +1 flavors of staggered fermions directly at the physical values of the quark masses and in volumes of linear extent larger than 6 fm. The continuum limit is carried out using six different lattice spacings. All connected and disconnected contributions are calculated, up to and including those of the charm.

Analysis of the spectral vanishing viscosity method for periodic conservation laws

NASA Technical Reports Server (NTRS)

Maday, Yvon; Tadmor, Eitan

1988-01-01

The convergence of the spectral vanishing method for both the spectral and pseudospectral discretizations of the inviscid Burgers' equation is analyzed. It is proven that this kind of vanishing viscosity is responsible for a spectral decay of those Fourier coefficients located toward the end of the computed spectrum; consequently, the discretization error is shown to be spectrally small independent of whether the underlying solution is smooth or not. This in turn implies that the numerical solution remains uniformly bounded and convergence follows by compensated compactness arguments.

Vanishing twin syndrome among ART singletons and pregnancy outcomes

PubMed Central

Magnus, Maria C; Ghaderi, Sara; Morken, Nils-Halvdan; Magnus, Per; Bente Romundstad, Liv; Skjærven, Rolv; Wilcox, Allen J; Eldevik Håberg, Siri

2017-01-01

born SGA, with an adjusted odds ratio (OR) (95% CI) of 1.48 (1.07, 2.03) compared to all ART singletons without VTS, and 2.79 (1.12, 6.91) in the sibship analyses. ART singletons with VTS were also more likely to be born preterm, although this difference did not reach statistical significance. LIMITATIONS REASONS FOR CAUTION We did not have information on maternal socio-economic status, but this factor is accounted for in the sibship analyses. We also had no information on whether fresh or frozen embryos were replaced. WIDER IMPLICATIONS OF THE FINDINGS The reduction in birth weight and increased risk of SGA in ART singletons with VTS may suggest the presence of harmful intrauterine factors with long-term health impact. While vanishing twins are not routinely observed in naturally conceived pregnancies, loss of a twin is potentially a risk factor for the surviving foetus in any pregnancy. This could be further explored in large samples of naturally conceived pregnancies with the necessary information. STUDY FUNDING/COMPETING INTEREST(S) The authors of this study are supported in part by the UK Medical Research Council, US National Institute of Environmental Health Sciences and the Norwegian Research Council. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER N/A. PMID:29025107

Photocatalytic quartz fiber felts with carbon-connected TiO2 nanoparticles for capillarity-driven continuous-flow water treatment

NASA Astrophysics Data System (ADS)

Zhang, Xiaofei; Su, Xiaowen; Gao, Wenqiang; Wang, Fulei; Liu, Zhihe; Zhan, Jie; Liu, Baishan; Wang, Ruosong; Liu, Hong; Sang, Yuanhua

2018-06-01

Immobility of photocatalysts on substrates is a vital factor for the practical application of photocatalysis in polluted water/air treatment. In this study, TiO2 homogenously loaded quartz fiber felt was prepared by assembling of carboxyl-contained organic molecules functionalized TiO2 nanoparticles on the surface of amino group-modified quartz fiber by electrostatic adsorption between them and followed by an anneal process. The immobilization of TiO2 nanoparticles overcomes one main obstacle of the photocatalysts recycling in photocatalysis application. In addition, a plasma treatment endowed the hybrid photocatalyst a high hydrophilic property. Due to the homogeneous distribution of TiO2, charge carriers' separation by carbon, and full contact between water and the photocatalyst derived from the high hydrophilia, the TiO2/quartz fiber felt shows excellent photocatalytic performance. Based on the stable loading and the capillarity effect of the contacted fibers photocatalyst, a demo capillarity-driven continuous-flow water treatment photocatalysis reactor was designed and built up. The TiO2 nanoparticle/quartz fiber hybrid photocatalyst can disposal organic contaminants in actual industrial waste water from a dyeing factory in the continuous-flow reactor. The chemical oxygen demand (COD) of the industrial waste water was decreased from 104 to 45 mg/L, overcoming the problem of deep water treatment which is difficult to solve by other methods. This study provides a new photocatalyst and reaction mode for the continuous-flow photocatalysis application.

A Lagrangian model for soil water dynamics: can we step beyond Richard's equation while preserving capillarity as first order control?

NASA Astrophysics Data System (ADS)

Zehe, Erwin; Jackisch, Conrad

2016-04-01

Water storage in the unsaturated zone is controlled by capillary forces which increase nonlinearly with decreasing pore size, because water acts as a wetting fluid in soil. The standard approach to represent capillary and gravity controlled soil water dynamics is the Darcy-Richards equation in combination with suitable soil water characteristics. This continuum model essentially assumes capillarity controlled diffusive fluxes to dominate soil water dynamics under local thermodynamic equilibrium conditions. Today we know that the assumptions of local equilibrium conditions e.g. and a mainly diffusive flow are often not appropriate, particularly during rainfall events in structured soils. Rapid or preferential flow imply a strong local disequilibrium and imperfect mixing between a fast fraction of soil water, traveling in interconnected coarse pores or non-capillary macropores, and the slower diffusive flow in finer fractions of the pore space. Although various concepts have been proposed to overcome the inability of the Darcy - Richards concept to cope with not-well mixed preferential flow, we still lack an approach that is commonly accepted. Notwithstanding the listed short comings, one should not mistake the limitations of the Richards equation with non-importance of capillary forces in soil. Without capillarity infiltrating rainfall would drain into groundwater bodies, leaving an empty soil as the local equilibrium state - there would be no soil water dynamics at all, probably even no terrestrial vegetation without capillary forces. Better alternatives for the Darcy-Richards approach are thus highly desirable, as long they preserve the grain of "truth" about capillarity as first order control. Here we propose such an alternative approach to simulate soil moisture dynamics in a stochastic and yet physical way. Soil water is represented by particles of constant mass, which travel according to the Itô form of the Fokker Planck equation. The model concept builds on

On the monoaxial stabilization of a rigid body under vanishing restoring torque

NASA Astrophysics Data System (ADS)

Aleksandrov, A. Yu.; Aleksandrova, E. B.; Tikhonov, A. A.

2018-05-01

The problem of monoaxial stabilization of a rigid body is studied. It is assumed that a linear time-invariant dissipative torque and a time-varying restoring torque vanishing as time increases act on the body. Both the case of linear restoring torque and that of essentially nonlinear one are considered. With the aid of the decomposition method, conditions are obtained under which we can guarantee the asymptotic stability of an equilibrium position of the body despite the vanishing of the restoring torque. A numerical simulation is provided to demonstrate the effectiveness of our theoretical results.

Vanishing of local non-Gaussianity in canonical single field inflation

NASA Astrophysics Data System (ADS)

Bravo, Rafael; Mooij, Sander; Palma, Gonzalo A.; Pradenas, Bastián

2018-05-01

We study the production of observable primordial local non-Gaussianity in two opposite regimes of canonical single field inflation: attractor (standard single field slow-roll inflation) and non attractor (ultra slow-roll inflation). In the attractor regime, the standard derivation of the bispectrum's squeezed limit using co-moving coordinates gives the well known Maldacena's consistency relation fNL = 5 (1‑ns) / 12. On the other hand, in the non-attractor regime, the squeezed limit offers a substantial violation of this relation given by fNL = 5/2. In this work we argue that, independently of whether inflation is attractor or non-attractor, the size of the observable primordial local non-Gaussianity is predicted to be fNLobs = 0 (a result that was already understood to hold in the case of attractor models). To show this, we follow the use of the so-called Conformal Fermi Coordinates (CFC), recently introduced in the literature. These coordinates parametrize the local environment of inertial observers in a perturbed FRW spacetime, allowing one to identify and compute gauge invariant quantities, such as n-point correlation functions. Concretely, we find that during inflation, after all the modes have exited the horizon, the squeezed limit of the 3-point correlation function of curvature perturbations vanishes in the CFC frame, regardless of the inflationary regime. We argue that such a cancellation should persist after inflation ends.

The Vanishing Tetrad Test: Another Test of Model Misspecification

ERIC Educational Resources Information Center

Roos, J. Micah

2014-01-01

The Vanishing Tetrad Test (VTT) (Bollen, Lennox, & Dahly, 2009; Bollen & Ting, 2000; Hipp, Bauer, & Bollen, 2005) is an extension of the Confirmatory Tetrad Analysis (CTA) proposed by Bollen and Ting (Bollen & Ting, 1993). VTT is a powerful tool for detecting model misspecification and can be particularly useful in cases in which…

Strong Capillarity, Chemisorption, and Electrocatalytic Capability of Crisscrossed Nanostraws Enabled Flexible, High-Rate, and Long-Cycling Lithium-Sulfur Batteries.

PubMed

Ma, Lianbo; Zhang, Wenjun; Wang, Lei; Hu, Yi; Zhu, Guoyin; Wang, Yanrong; Chen, Renpeng; Chen, Tao; Tie, Zuoxiu; Liu, Jie; Jin, Zhong

2018-05-22

The development of flexible lithium-sulfur (Li-S) batteries with high energy density and long cycling life are very appealing for the emerging flexible, portable, and wearable electronics. However, the progress on flexible Li-S batteries was limited by the poor flexibility and serious performance decay of existing sulfur composite cathodes. Herein, we report a freestanding and highly flexible sulfur host that can simultaneously meet the flexibility, stability, and capacity requirements of flexible Li-S batteries. The host consists of a crisscrossed network of carbon nanotubes reinforced CoS nanostraws (CNTs/CoS-NSs). The CNTs/CoS-NSs with large inner space and high conductivity enable high loading and efficient utilization of sulfur. The strong capillarity effect and chemisorption of CNTs/CoS-NSs to sulfur species were verified, which can efficiently suppress the shuttle effect and promote the redox kinetics of polysulfides. The sulfur-encapsulated CNTs/CoS-NSs (S@CNTs/CoS-NSs) cathode in Li-S batteries exhibits superior performance, including high discharge capacity, rate capability (1045 mAh g -1 at 0.5 C and 573 mAh g -1 at 5.0 C), and cycling stability. Intriguingly, the soft-packed Li-S batteries based on S@CNTs/CoS-NSs cathode show good flexibility and stability upon bending.

Vanishing Ice: Art as a Tool for Documenting Climate Change

ERIC Educational Resources Information Center

Kothe, Elsa Lenz; Maute, Mary Jo; Brewer, Chris

2015-01-01

The work of artists as naturalists, scientists, documentarians, and explorers has long been part of an interdisciplinary approach to scientific studies. As museum educators, this group of authors has gained inspiration from the exhibition Vanishing Ice: Alpine and Polar Landscapes in Art, 1775-2012 (Matilsky, 2013) and discovered how historical…

Capillarization in skeletal muscle of rats with cardiac hypertrophy.

PubMed

Degens, Hans; Anderson, Rebecca K; Alway, Stephen E

2002-02-01

Exercise intolerance during chronic heart failure (CHF) is localized mainly in skeletal muscle. A decreased capillarization may impair exchange of oxygen between capillaries and muscle tissue and in this way contribute to exercise intolerance. We assessed changes in capillary supply in plantaris and diaphragm muscles of a rat aorta-caval fistula (ACF) preparation, a volume overload model for CHF. An ACF was created under equithesin anesthesia. Plantaris and diaphragm muscles were removed 6 wk postsurgery and examined for myosin heavy chain (MyHC) content and capillary supply. Cardiac hypertrophy was 96% (P < 0.002) after ACF. The Type IIb MyHC content of the plantaris muscles increased (33.9 +/- 3.3 vs 49.8 +/- 3.8%; mean +/- SEM) at the expense of Type IIa MyHC (17.6 +/- 1.8 vs 11.2 +/- 1.7%) in ACF rats (P < 0.05). In the diaphragm, the number of Type I (32.1 +/- 2.3 vs 40.6 +/- 2.7%) and IIb fibers (40.6 +/- 1.9 vs 49.6 +/- 3.6%) increased at the expense of Type IIa fibers (26.8 +/- 2.5 vs 9.4 +/- 0.9%) (P < 0.05). The capillary number per fiber did not change, and this indicated that no capillary loss occurred with ACF. Also, the capillary density was maintained in the diaphragm and plantaris muscles of ACF rats. Furthermore, the coupling between fiber type, size, and metabolic type of surrounding fibers, with the capillary supply to a fiber, was maintained in rats with an ACF. The cardiac hypertrophy induced by volume overload seems adequate to prevent atrophy and changes in the microcirculation of limb and diaphragm muscles.

Programmable colloidal molecules from sequential capillarity-assisted particle assembly

PubMed Central

Ni, Songbo; Leemann, Jessica; Buttinoni, Ivo; Isa, Lucio; Wolf, Heiko

2016-01-01

The assembly of artificial nanostructured and microstructured materials which display structures and functionalities that mimic nature’s complexity requires building blocks with specific and directional interactions, analogous to those displayed at the molecular level. Despite remarkable progress in synthesizing “patchy” particles encoding anisotropic interactions, most current methods are restricted to integrating up to two compositional patches on a single “molecule” and to objects with simple shapes. Currently, decoupling functionality and shape to achieve full compositional and geometrical programmability remains an elusive task. We use sequential capillarity-assisted particle assembly which uniquely fulfills the demands described above. This is a new method based on simple, yet essential, adaptations to the well-known capillary assembly of particles over topographical templates. Tuning the depth of the assembly sites (traps) and the surface tension of moving droplets of colloidal suspensions enables controlled stepwise filling of traps to “synthesize” colloidal molecules. After deposition and mechanical linkage, the colloidal molecules can be dispersed in a solvent. The template’s shape solely controls the molecule’s geometry, whereas the filling sequence independently determines its composition. No specific surface chemistry is required, and multifunctional molecules with organic and inorganic moieties can be fabricated. We demonstrate the “synthesis” of a library of structures, ranging from dumbbells and triangles to units resembling bar codes, block copolymers, surfactants, and three-dimensional chiral objects. The full programmability of our approach opens up new directions not only for assembling and studying complex materials with single-particle-level control but also for fabricating new microscale devices for sensing, patterning, and delivery applications. PMID:27051882

Vanishing thyroid gland tumors: Infarction as consequence of FNA?

PubMed

Kholová, Ivana

2016-07-01

Fine-needle aspiration (FNA)-induced secondary changes were described in various organs. Complete replacement of tumor by necrosis causes diagnostic and management problems. Seven cases of totally or partially vanished thyroid lesions were identified from the archive of Department of Pathology, Fimlab Laboratories within 5 year period. Histopathological slides were revised in all cases. Total thyroidectomy or lobectomy samples were from 4 females and 3 males patients aged 37-83 years (mean 67.1 years). Imaging data were available in 6 cases. Cytology slides and data were available only in 3 cases: two revealed follicular neoplasm and one was insufficient according to Bethesda system. In 5 cases, final histopathology revealed total necrosis of the lesion with only one case with available cytological diagnosis of oncocytic follicular neoplasm. In remaining 2 cases, replacement by necrosis was partial. Of note, in three cases, oncocytic metaplasia was present. Total histopathological blocking with thorough check of capsular areas is recommended in necrotic tumors. Vanishing thyroid lesion phenomenon is rare, but in cases of disappearance of tumor, preoperative cytology diagnosis is the only clue for the patient management. Diagn. Cytopathol. 2016;44:568-573. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

On the existence of horizons in spacetimes with vanishing curvature invariants

NASA Astrophysics Data System (ADS)

Senovilla, José M. M.

2003-11-01

A direct very simple proof that there can be no closed trapped surfaces (ergo no black hole regions) in spacetimes with all curvature scalar invariants vanishing is given. Explicit examples of the recently introduced ``dynamical horizons'' which nevertheless do not enclose any trapped region are presented too.

Capillary wave propagation during the delamination of graphene by the precursor films in electro-elasto-capillarity

PubMed Central

Zhu, Xueyan; Yuan, Quanzi; Zhao, Ya-Pu

2012-01-01

Molecular dynamics simulations were carried out to explore the capillary wave propagation induced by the competition between one upper precursor film (PF) on the graphene and one lower PF on the substrate in electro-elasto-capillarity (EEC). During the wave propagation, the graphene was gradually delaminated from the substrate by the lower PF. The physics of the capillary wave was explored by the molecular kinetic theory. Besides, the dispersion relation of the wave was obtained theoretically. The theory showed that the wave was controlled by the driving work difference of the two PFs. Simulating the EEC process under different electric field intensities (E), the wave velocity was found insensitive to E. We hope this research could expand our knowledge on the wetting, electrowetting and EEC. As a potential application, the electrowetting of the PF between the graphene and the substrate is a promising candidate for delaminating graphene from substrate. PMID:23226593

Further Comments on a Vanishing Singlet Axial Vector Charge

NASA Astrophysics Data System (ADS)

Cheng, T. P.; Kochelev, N. I.; Vento, Vicente

The recent suggestion of a vanishing flavor-singlet axial-charge of nucleon due to a nontrivial vacuum structure is further amplified. A perturbative QCD discussion, applicable for the heavy quark contributions, relates it to the physics of the decoupling theorem. It is also shown that gA0˜= 0 leads to a negative η‧-meson-quark coupling, which has been found to be compatible with the chiral quark model phenomenology.

Vanishing twin syndrome among ART singletons and pregnancy outcomes.

PubMed

Magnus, Maria C; Ghaderi, Sara; Morken, Nils-Halvdan; Magnus, Per; Bente Romundstad, Liv; Skjærven, Rolv; Wilcox, Allen J; Eldevik Håberg, Siri

2017-11-01

Among babies born by ART, do singleton survivors of a vanishing twin have lower birth weight than other singletons? Vanishing twin syndrome (VTS) was associated with lower birth weight among ART singletons; a sibship analysis indicated that the association was not confounded by maternal characteristics that remain stable between deliveries. Previous studies indicate that ART singletons with VTS have increased risk of adverse pregnancy outcomes, compared with other ART singletons. The potential contribution of unmeasured maternal background characteristics has been unclear. This was a Norwegian population-based registry study, including 17 368 mothers with 20 410 ART singleton deliveries between January 1984 and December 2013. The study population included 17 291 ART singletons without VTS, 638 ART singletons with VTS and 2418 ART singletons with uncertain vanishing twin status. We estimated differences in birth weight and gestational age comparing ART singletons with VTS first to all ART singletons without VTS, and subsequently to their ART siblings without VTS, using random- and fixed-effects linear regression, respectively. The corresponding comparisons for the associations with preterm birth and small for gestational age (SGA) were conducted using random-and fixed-effects logistic regression. The sibling analysis of preterm birth included 587 discordant siblings, while the sibling analysis of SGA included 674 discordant siblings. ART singletons with VTS had lower birth weight when compared to all ART singletons without VTS, with an adjusted mean difference (95% CI) of -116 g (-165, -67). When we compared ART singletons with VTS to their ART singletons sibling without VTS, the adjusted mean difference was -112 g (-209, -15). ART singletons with VTS also had increased risk of being born SGA, with an adjusted odds ratio (OR) (95% CI) of 1.48 (1.07, 2.03) compared to all ART singletons without VTS, and 2.79 (1.12, 6.91) in the sibship analyses. ART singletons with

Chiral phase structure of three flavor QCD at vanishing baryon number density

DOE PAGES

Bazavov, A.; Ding, H. -T.; Hegde, P.; ...

2017-04-12

In this paper, we investigate the phase structure of QCD with three degenerate quark flavors as a function of the degenerate quark masses at vanishing baryon number density. We use the highly improved staggered quarks on lattices with temporal extent N τ = 6 and perform calculations for six values of quark masses, which in the continuum limit correspond to pion masses in the range 80 MeV ≲ m π ≲ 230 MeV. By analyzing the volume and temperature dependence of the chiral condensate and chiral susceptibility, we find no direct evidence for a first-order phase transition in this rangemore » of pion mass values. Finally, relying on the universal scaling behaviors of the chiral observables near an anticipated chiral critical point, we estimate an upper bound for the critical pion mass m c π ≲ 50 MeV, below which a region of first-order chiral phase transition is favored.« less

The Vanishing Ball Illusion: A new perspective on the perception of dynamic events.

PubMed

Kuhn, Gustav; Rensink, Ronald A

2016-03-01

Our perceptual experience is largely based on prediction, and as such can be influenced by knowledge of forthcoming events. This susceptibility is commonly exploited by magicians. In the Vanishing Ball Illusion, for example, a magician tosses a ball in the air a few times and then pretends to throw the ball again, whilst secretly concealing it in his hand. Most people claim to see the ball moving upwards and then vanishing, even though it did not leave the magician's hand (Kuhn & Land, 2006; Triplett, 1900). But what exactly can such illusions tell us? We investigated here whether seeing a real action before the pretend one was necessary for the Vanishing Ball Illusion. Participants either saw a real action immediately before the fake one, or only a fake action. Nearly one third of participants experienced the illusion with the fake action alone, while seeing the real action beforehand enhanced this effect even further. Our results therefore suggest that perceptual experience relies both on long-term knowledge of what an action should look like, as well as exemplars from the immediate past. In addition, whilst there was a forward displacement of perceived location in perceptual experience, this was not found for oculomotor responses, consistent with the proposal that two separate systems are involved in visual perception. Copyright © 2015 Elsevier B.V. All rights reserved.

Anti-levitation of Landau levels in vanishing magnetic fields

NASA Astrophysics Data System (ADS)

Pan, W.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

Soon after the discovery of the quantum Hall effects in two-dimensional electron systems, the question on the fate of the extended states in a Landau level in vanishing magnetic (B) field arose. Many theoretical models have since been proposed, and experimental results remain inconclusive. In this talk, we report experimental observation of anti-levitation behavior of Landau levels in vanishing B fields (down to as low as B 58 mT) in a high quality heterojunction insulated-gated field-effect transistor (HIGFET). We observed that, in the Landau fan diagram of electron density versus magnetic field, the positions of the magneto-resistance minima at Landau level fillings ν = 4, 5, 6 move below the ``traditional'' Landau level line to lower electron densities. This clearly differs from what was observed in the earlier experiments where in the same Landau fan plot the density moved up. Our result strongly supports the anti-levitation behavior predicted recently. Moreover, the even and odd Landau level filling states show quantitatively different behaviors in anti-levitation, suggesting that the exchange interactions, which are important at odd fillings, may play a role. SNL is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000.

Nonequilibrium capillarity effects in multiphase flow through small volume fractured porous media

NASA Astrophysics Data System (ADS)

Tang, M.; Zhan, H.; Lu, S.

2017-12-01

Analyzing and understanding the capillary pressure curves in fractured porous media is a crucial subject in a number of industrial applications, such as crude oil recovery in the fractured reservoir, CO2 sequestration in fractured brine aquifers and shale gas development. Many studies have observed the significant nonequilibrium capillarity effects in multiphase flow through porous media and proposed that conventional equilibrium capillary pressure may not accurately describe transient two-phase flow behavior under dynamical conditions. To date, only several laboratory experiments and numerical models have been conducted into investigating the characteristic of nonequilibrium capillary pressure in unfractured porous media, a clear picture of the effects of fractures on the dynamic capillary pressure in fractured porous media remains elusive. In this study, four digital porous models were built based on CT image data from ZEISS Xradia 520 Versa CT scanning, a series of direct simulations of multiphase flow in fractured porous media were carried out based on lattice Boltzmann method and three-dimensional porous models. The results show that both the aperture and orientation of the fractures have significant effects on the nonequilibrium capillary pressure coefficients and multiphase flow behaviors. The nonequilibrium capillary pressure coefficients in fractured porous media are one to two orders of magnitude lower than unfractured porous media. This study presents a new direct simulation based methodology for the detailed analysis of nonequilibrium capillary pressure in fractured porous media.

Daily muscle stretching enhances blood flow, endothelial function, capillarity, vascular volume and connectivity in aged skeletal muscle.

PubMed

Hotta, Kazuki; Behnke, Bradley J; Arjmandi, Bahram; Ghosh, Payal; Chen, Bei; Brooks, Rachael; Maraj, Joshua J; Elam, Marcus L; Maher, Patrick; Kurien, Daniel; Churchill, Alexandra; Sepulveda, Jaime L; Kabolowsky, Max B; Christou, Demetra D; Muller-Delp, Judy M

2018-05-15

In aged rats, daily muscle stretching increases blood flow to skeletal muscle during exercise. Daily muscle stretching enhanced endothelium-dependent vasodilatation of skeletal muscle resistance arterioles of aged rats. Angiogenic markers and capillarity increased in response to daily stretching in muscles of aged rats. Muscle stretching performed with a splint could provide a feasible means of improving muscle blood flow and function in elderly patients who cannot perform regular aerobic exercise. Mechanical stretch stimuli alter the morphology and function of cultured endothelial cells; however, little is known about the effects of daily muscle stretching on adaptations of endothelial function and muscle blood flow. The present study aimed to determine the effects of daily muscle stretching on endothelium-dependent vasodilatation and muscle blood flow in aged rats. The lower hindlimb muscles of aged Fischer rats were passively stretched by placing an ankle dorsiflexion splint for 30 min day -1 , 5 days week -1 , for 4 weeks. Blood flow to the stretched limb and the non-stretched contralateral limb was determined at rest and during treadmill exercise. Endothelium-dependent/independent vasodilatation was evaluated in soleus muscle arterioles. Levels of hypoxia-induced factor-1α, vascular endothelial growth factor A and neuronal nitric oxide synthase were determined in soleus muscle fibres. Levels of endothelial nitric oxide synthase and superoxide dismutase were determined in soleus muscle arterioles, and microvascular volume and capillarity were evaluated by microcomputed tomography and lectin staining, respectively. During exercise, blood flow to plantar flexor muscles was significantly higher in the stretched limb. Endothelium-dependent vasodilatation was enhanced in arterioles from the soleus muscle from the stretched limb. Microvascular volume, number of capillaries per muscle fibre, and levels of hypoxia-induced factor-1α, vascular endothelial growth

On the impossibility of defining adhesive hard spheres as sticky limit of a hard-sphere-Yukawa potential.

PubMed

Gazzillo, Domenico

2011-03-28

For fluids of molecules with short-ranged hard-sphere-Yukawa (HSY) interactions, it is proven that the Noro-Frenkel "extended law of corresponding states" cannot be applied down to the vanishing attraction range, since the exact HSY second virial coefficient diverges in such a limit. It is also shown that, besides Baxter's original approach, a fully correct alternative definition of "adhesive hard spheres" can be obtained by taking the vanishing-range-limit (sticky limit) not of a Yukawa tail, as is commonly done, but of a slightly different potential with a logarithmic-Yukawa attraction.

An unusual neuroimaging finding and response to immunotherapy in a child with genetically confirmed vanishing white matter disease.

PubMed

Singh, Rahul Raman; Livingston, John; Lim, Ming; Berry, Ian R; Siddiqui, Ata

2017-03-01

We present an unusual neuroimaging finding in a young girl with genetically confirmed vanishing white matter disease and a possible response to immunotherapy. 2.5 yr old girl, presented with acute onset unsteadiness and encephalopathy following a viral illness. MRI showed global symmetric white matter abnormality, with symmetric enhancement of cranial nerves (III and V) and of cervical and lumbar roots. She received immunotherapy for her encephalopathic illness with white matter changes. Follow up neuroimaging showed resolution of white matter edema and resolution of the change in the brainstem. Genetic testing confirmed a diagnosis of vanishing white matter disease (VWMD). Craniospinal nerve enhancement and possible response to immunotherapy has not been described in vanishing white matter disease. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Vanishing Boundaries: When Teaching "about" Religion Becomes "Spiritual Guidance" in the Classroom

ERIC Educational Resources Information Center

Simmons, John K.

2006-01-01

This article revisits the pedagogical dilemma of maintaining neutrality in the religious studies/theology classroom. I argue that if the boundary between teaching about religion and actually teaching spirituality seems to be vanishing, it is because the boundary was inappropriately constructed in the first place. To the extent that the religious…

Vanishing white matter disease presenting as opsoclonus myoclonus syndrome in childhood--a case report and review of the literature.

PubMed

Klingelhoefer, Lisa; Misbahuddin, Anjum; Jawad, Tania; Mellers, John; Jarosz, Jozef; Weeks, Robert; Ray Chaudhuri, Kallol

2014-07-01

Vanishing white matter disease is caused by mutations of the eukaryotic translation initiation factor 2B (EIF2B) and is a prevalent cause of inherited childhood leukoencephalopathy. Infantile and early childhood onset forms are associated with chronic progressive neurological signs, with episodes of rapid, neurological, and poor prognosis, with death in few months or years. In contrast, onset in late childhood and adult onset is rare and is associated with long-term survival because of milder signs and slow progression. We present a patient with a genetically proven vanishing white matter disease, typical brain MRI, presenting with opsoclonus myoclonus in early childhood and a delayed development of adult multifocal dystonia and schizoaffective disorder with continued survival. In addition we have also reviewed the relevant literature based on 42 previous articles summarizing clinical details of 318 individuals with vanishing white matter disease (single case reports to case series). In 283, genetic mutation of EIF2B was confirmed with the onset of vanishing white matter disease reported as antenatal (seven), infantile (eight), early childhood (107), between infantile and early childhood (20), late childhood (25), between early and late childhood (three), adult (68), and between late childhood and adult (21). Various movement disorders have been described with vanishing white matter disease either at presentation (mimicking an opsoclonus myoclonus syndrome) or in adulthood (dystonia and myoclonus) with continuing survival. Relatively preserved cognition is a novel presentation and is reported in this article along with a comprehensive literature review. Copyright © 2014 Elsevier Inc. All rights reserved.

Local invariants vanishing on stationary horizons: a diagnostic for locating black holes.

PubMed

Page, Don N; Shoom, Andrey A

2015-04-10

Inspired by the example of Abdelqader and Lake for the Kerr metric, we construct local scalar polynomial curvature invariants that vanish on the horizon of any stationary black hole: the squared norms of the wedge products of n linearly independent gradients of scalar polynomial curvature invariants, where n is the local cohomogeneity of the spacetime.

Ursodeoxycholic acid treatment of vanishing bile duct syndromes

PubMed Central

Pusl, Thomas; Beuers, Ulrich

2006-01-01

Vanishing bile duct syndromes (VBDS) are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Ursodeoxycholic acid (UDCA), a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids. PMID:16773706

Design of a projection display screen with vanishing color shift for rear-projection HDTV

NASA Astrophysics Data System (ADS)

Liu, Xiu; Zhu, Jin-lin

1996-09-01

Using bi-convex cylinder lens with matrix structure, the transmissive projection display screen with high contrast and wider viewing angle has been widely used in large rear projection TV and video projectors, it obtained a inhere color shift and puzzled the designer of display screen for RGB projection tube in-line adjustment. Based on the method of light beam racing, the general software of designing projection display screen has been developed and the computer model of vanishing color shift for rear projection HDTV has bee completed. This paper discussed the practical designing method to vanish the defect of color shift and mentioned the relations between the primary optical parameters of display screen and relative geometry sizes of lens' surface. The distributions of optical gain to viewing angle and the influences on engineering design are briefly analyzed.

Non-vanishing superpotentials in heterotic string theory and discrete torsion

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

Buchbinder, Evgeny I.; Ovrut, Burt A.

Here, we study the non-perturbative superpotential in E8 E8 heterotic string theory on a non-simply connected Calabi-Yau manifold X, as well as on its simply connected covering space ~X . The superpotential is induced by the string wrapping holomorphic, isolated, genus 0 curves. According to the residue theorem of Beasley and Witten, the non-perturbative superpotential must vanish in a large class of heterotic vacua because the contributions from curves in the same homology class cancel each other. We point out, however, that in certain cases the curves treated in the residue theorem as lying in the same homology class, canmore » actually have different area with respect to the physical Kahler form and can be in different homology classes. In these cases, the residue theorem is not directly applicable and the structure of the superpotential is more subtle. We also show, in a specific example, that the superpotential is non-zero both on ~X and on X. On the non-simply connected manifold X, we explicitly compute the leading contribution to the superpotential from all holomorphic, isolated, genus 0 curves with minimal area. Furthermore, the reason for the non-vanishing of the superpotental on X is that the second homology class contains a finite part called discrete torsion. As a result, the curves with the same area are distributed among different torsion classes and, hence, do not cancel each other« less

Non-vanishing superpotentials in heterotic string theory and discrete torsion

DOE PAGES

Buchbinder, Evgeny I.; Ovrut, Burt A.

2017-01-10

Here, we study the non-perturbative superpotential in E8 E8 heterotic string theory on a non-simply connected Calabi-Yau manifold X, as well as on its simply connected covering space ~X . The superpotential is induced by the string wrapping holomorphic, isolated, genus 0 curves. According to the residue theorem of Beasley and Witten, the non-perturbative superpotential must vanish in a large class of heterotic vacua because the contributions from curves in the same homology class cancel each other. We point out, however, that in certain cases the curves treated in the residue theorem as lying in the same homology class, canmore » actually have different area with respect to the physical Kahler form and can be in different homology classes. In these cases, the residue theorem is not directly applicable and the structure of the superpotential is more subtle. We also show, in a specific example, that the superpotential is non-zero both on ~X and on X. On the non-simply connected manifold X, we explicitly compute the leading contribution to the superpotential from all holomorphic, isolated, genus 0 curves with minimal area. Furthermore, the reason for the non-vanishing of the superpotental on X is that the second homology class contains a finite part called discrete torsion. As a result, the curves with the same area are distributed among different torsion classes and, hence, do not cancel each other« less

Critique of Coleman's Theory of the Vanishing Cosmological Constant

NASA Astrophysics Data System (ADS)

Susskind, Leonard

In these lectures I would like to review some of the criticisms to the Coleman worm-hole theory of the vanishing cosmological constant. In particular, I would like to focus on the most fundamental assumption that the path integral over topologies defines a probability for the cosmological constant which has the form EXP(A) with A being the Baum-Hawking-Coleman saddle point. Coleman argues that the euclideam path integral over all geometries may be dominated by special configurations which consist of large smooth "spheres" connected by any number of narrow wormholes. Formally summing up such configurations gives a very divergent expression for the path integral…

Rate limits in silicon sheet growth - The connections between vertical and horizontal methods

NASA Technical Reports Server (NTRS)

Thomas, Paul D.; Brown, Robert A.

1987-01-01

Meniscus-defined techniques for the growth of thin silicon sheets fall into two categories: vertical and horizontal growth. The interactions of the temperature field and the crystal shape are analyzed for both methods using two-dimensional finite-element models which include heat transfer and capillarity. Heat transfer in vertical growth systems is dominated by conduction in the melt and the crystal, with almost flat melt/crystal interfaces that are perpendicular to the direction of growth. The high axial temperature gradients characteristic of vertical growth lead to high thermal stresses. The maximum growth rate is also limited by capillarity which can restrict the conduction of heat from the melt into the crystal. In horizontal growth the melt/crystal interface stretches across the surface of the melt pool many times the crystal thickness, and low growth rates are achievable with careful temperature control. With a moderate axial temperature gradient in the sheet a substantial portion of the latent heat conducts along the sheet and the surface of the melt pool becomes supercooled, leading to dendritic growth. The thermal supercooling is surpressed by lowering the axial gradient in the crystal; this configuration is the most desirable for the growth of high quality crystals. An expression derived from scaling analysis relating the growth rate and the crucible temperature is shown to be reliable for horizontal growth.

Vanishing white matter disease with a novel EIF2B5 mutation: A 10-year follow-up.

PubMed

Bektaş, Gonca; Yeşil, Gözde; Özkan, Melis Ulak; Yıldız, Edibe Pembegül; Uzunhan, Tuğçe Aksu; Çalışkan, Mine

2018-06-19

Vanishing white matter disease is a heterogeneous disorder caused by mutation in one of the five genes encoding subunits of the eukaryotic initiation factor eIF2B. It is a heterogeneous disorder due to phenotypic variation and a clear genotype-phenotype correlation could not be established so far. We describe a novel mutation in the EIF2B5 gene by analyzing the clinical phenotype and the progression of brain lesions for 10 years. A novel mutation in the EIF2B5 gene was detected in the heterozygous state; c.1688G > A (p. Arg563Gln) mutation in exon 12, accompanied by a previously detected c.806G > A (p. Arg269Gln) mutation in exon 6, leading to substitution of arginine for a glutamine. This compound heterozygous mutation was associated with disease onset at early childhood and relatively slow progression of neurological deterioration. In contrast to previous findings indicated the association of c.806G > A mutation and peripheral neuropathy in patients with vanishing white matter disease, electromyography of our case was normal. The corpus callosum inner rim was the affected area at early stages, which may be remarkable for early diagnosis of vanishing white matter disease. Serial follow-up magnetic resonance imaging revealed the white matter signal abnormality, subsequently cystic degeneration and decrease in white matter volume. The novel mutation c.1688G > A in compound heterozygous state leads to intermediate phenotype of the vanishing white matter disease. In the early stages of the disease the signal abnormality in the corpus callosum inner rim might be remarkable. Copyright © 2018 Elsevier B.V. All rights reserved.

Vanishing "tattoo" multisensor for biomedical diagnostics

NASA Astrophysics Data System (ADS)

Moczko, E.; Meglinski, I.; Piletsky, S.

2008-02-01

Currently, precise non-invasive diagnostics systems for the real-time multi detection and monitoring of physiological parameters and chemical analytes in the human body are urgently required by clinicians, physiologists and bio-medical researchers. We have developed a novel cost effective smart 'vanishing tattoo' (similar to temporary child's tattoos) consisting of environmental-sensitive dyes. Painlessly impregnated into the skin the smart tattoo is capable of generating optical/fluorescence changes (absorbance, transmission, reflectance, emission and/or luminescence within UV, VIS or NIR regions) in response to physical or chemical changes. These changes allow the identification of colour pattern changes similar to bar-code scanning. Such a system allows an easy, cheap and robust comprehensive detection of various parameters and analytes in a small volume of sample (e.g. variations in pH, temperature, ionic strength, solvent polarity, presence of redox species, surfactants, oxygen). These smart tattoos have possible applications in monitoring the progress of disease and transcutaneous drug delivery. The potential of this highly innovative diagnostic tool is wide and diverse and can impact on routine clinical diagnostics, general therapeutic management, skin care and cosmetic products testing as well as fundamental physiological investigations.

Existence of the passage to the limit of an inviscid fluid.

PubMed

Goldobin, Denis S

2017-11-24

In the dynamics of a viscous fluid, the case of vanishing kinematic viscosity is actually equivalent to the Reynolds number tending to infinity. Hence, in the limit of vanishing viscosity the fluid flow is essentially turbulent. On the other hand, the Euler equation, which is conventionally adopted for the description of the flow of an inviscid fluid, does not possess proper turbulent behaviour. This raises the question of the existence of the passage to the limit of an inviscid fluid for real low-viscosity fluids. To address this question, one should employ the theory of turbulent boundary layer near an inflexible boundary (e.g., rigid wall). On the basis of this theory, one can see how the solutions to the Euler equation become relevant for the description of the flow of low-viscosity fluids, and obtain the small parameter quantifying accuracy of this description for real fluids.

The Vanishing West: 1964-2010--The Disappearance of Western Civilization from the American Undergraduate Curriculum

ERIC Educational Resources Information Center

Ricketts, Glenn; Wood, Peter R.; Balch, Stephen H.; Thorne, Ashley

2011-01-01

"The Vanishing West" traces the decline and near extinction of the Western Civilization history survey course in America's top colleges and universities from 1964 to 2010. This course, covering classical antiquity to the present, was once part of the undergraduate curriculum's intellectual bedrock, not only because it was often a graduation…

Vanishing tattoo multi-sensor for biomedical diagnostics

NASA Astrophysics Data System (ADS)

Moczko, E.; Meglinski, I.; Piletsky, S.

2008-04-01

Currently, precise non-invasive diagnostics systems for the real-time multi detection and monitoring of physiological parameters and chemical analytes in the human body are urgently required by clinicians, physiologists and bio-medical researchers. We have developed a novel cost effective smart 'vanishing tattoo' (similar to temporary child's tattoos) consisting of environmental-sensitive dyes. Painlessly impregnated into the skin the smart tattoo is capable of generating optical/fluorescence changes (absorbance, transmission, reflectance, emission and/or luminescence within UV, VIS or NIR regions) in response to physical or chemical changes. These changes allow the identification of colour pattern changes similar to bar-code scanning. Such a system allows an easy, cheap and robust comprehensive detection of various parameters and analytes in a small volume of sample (e.g. variations in pH, temperature, ionic strength, solvent polarity, presence of redox species, surfactants, oxygen). These smart tattoos have possible applications in monitoring the progress of disease and transcutaneous drug delivery. The potential of this highly innovative diagnostic tool is wide and diverse and can impact on routine clinical diagnostics, general therapeutic management, skin care and cosmetic products testing as well as fundamental physiological investigations.

Vanishing flora--lost chemistry: the scents of endangered plants around the world.

PubMed

Kaiser, Roman

2004-01-01

As part of our broad and ongoing evaluation of the olfactory components of fragrant plants and flowers during the past 25 years, we have encountered an astounding number of interestingly scented, but endangered plant species. In appreciation of nature's marvels in these species, we are compiling a report on their scent compositions and complementary information in an upcoming book 'Vanishing Flora--Lost Chemistry'. In this paper, a few examples of endangered plant species and their scent components are presented as a brief introduction to the concept of the book project.

Upper limit on NUT charge from the observed terrestrial Sagnac effect

NASA Astrophysics Data System (ADS)

Kulbakova, A.; Karimov, R. Kh; Izmailov, R. N.; Nandi, K. K.

2018-06-01

The exact Sagnac delay in the Kerr–Taub–NUT (Newman–Unti–Tamburino) spacetime is derived in the equatorial plane for non-geodesic as well as geodesic circular orbits. The resulting formula, being exact, can be directly applied to motion in the vicinity of any spinning object including black holes but here we are considering only the terrestrial case since observational data are available. The formula reveals that, in the limit of spin , the delay does not vanish. This fact is similar to the non-vanishing of Lense–Thirring precession under even though the two effects originate from different premises. Assuming a reasonable input that the Kerr–Taub–NUT corrections are subsumed in the average residual uncertainty in the measured Sagnac delay, we compute upper limits on the NUT charge n. It is found that the upper limits on n are far larger than the Earth’s gravitational mass, which has not been detected in observations, implying that the Sagnac effect cannot constrain n to smaller values near zero. We find a curious difference between the delays for non-geodesic and geodesic clock orbits and point out its implication for the well known ‘twin paradox’ of special relativity.

Accretion of Jupiter-mass planets in the limit of vanishing viscosity

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

Szulágyi, J.; Morbidelli, A.; Crida, A.

In the core-accretion model, the nominal runaway gas-accretion phase brings most planets to multiple Jupiter masses. However, known giant planets are predominantly Jupiter mass bodies. Obtaining longer timescales for gas accretion may require using realistic equations of states, or accounting for the dynamics of the circumplanetary disk (CPD) in the low-viscosity regime, or both. Here we explore the second way by using global, three-dimensional isothermal hydrodynamical simulations with eight levels of nested grids around the planet. In our simulations, the vertical inflow from the circumstellar disk (CSD) to the CPD determines the shape of the CPD and its accretion rate.more » Even without a prescribed viscosity, Jupiter's mass-doubling time is ∼10{sup 4} yr, assuming the planet at 5.2 AU and a Minimum Mass Solar Nebula. However, we show that this high accretion rate is due to resolution-dependent numerical viscosity. Furthermore, we consider the scenario of a layered CSD, viscous only in its surface layer, and an inviscid CPD. We identify two planet-accretion mechanisms that are independent of the viscosity in the CPD: (1) the polar inflow—defined as a part of the vertical inflow with a centrifugal radius smaller than two Jupiter radii and (2) the torque exerted by the star on the CPD. In the limit of zero effective viscosity, these two mechanisms would produce an accretion rate 40 times smaller than in the simulation.« less

Towards Practical Application of Paper based Printed Circuits: Capillarity Effectively Enhances Conductivity of the Thermoplastic Electrically Conductive Adhesives

PubMed Central

Wu, Haoyi; Chiang, Sum Wai; Lin, Wei; Yang, Cheng; Li, Zhuo; Liu, Jingping; Cui, Xiaoya; Kang, Feiyu; Wong, Ching Ping

2014-01-01

Direct printing nanoparticle-based conductive inks onto paper substrates has encountered difficulties e.g. the nanoparticles are prone to penetrate into the pores of the paper and become partially segmented, and the necessary low-temperature-sintering process is harmful to the dimension-stability of paper. Here we prototyped the paper-based circuit substrate in combination with printed thermoplastic electrically conductive adhesives (ECA), which takes the advantage of the capillarity of paper and thus both the conductivity and mechanical robustness of the printed circuitsweredrastically improved without sintering process. For instance, the electrical resistivity of the ECA specimen on a pulp paper (6 × 10−5Ω·cm, with 50 wt% loading of Ag) was only 14% of that on PET film than that on PET film. This improvement has been found directly related to the sizing degree of paper, in agreement with the effective medium approximation simulation results in this work. The thermoplastic nature also enables excellent mechanical strength of the printed ECA to resist repeated folding. Considering the generality of the process and the wide acceptance of ECA technique in the modern electronic packages, this method may find vast applications in e.g. circuit boards, capacitive touch pads, and radio frequency identification antennas, which have been prototyped in the manuscript. PMID:25182052

Texture one zero Dirac neutrino mass matrix with vanishing determinant or trace condition

NASA Astrophysics Data System (ADS)

Singh, Madan

2018-06-01

In the light of non-zero and relatively large value of rector mixing angle (θ13), we have performed a detailed analysis of texture one zero neutrino mass matrix Mν in the scenario of vanishing determinant/trace conditions, assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of Mν, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at 3σ confidence level. Numerical and some approximate analytical results are presented.

Remarks on High Reynolds Numbers Hydrodynamics and the Inviscid Limit

NASA Astrophysics Data System (ADS)

Constantin, Peter; Vicol, Vlad

2018-04-01

We prove that any weak space-time L^2 vanishing viscosity limit of a sequence of strong solutions of Navier-Stokes equations in a bounded domain of R^2 satisfies the Euler equation if the solutions' local enstrophies are uniformly bounded. We also prove that t-a.e. weak L^2 inviscid limits of solutions of 3D Navier-Stokes equations in bounded domains are weak solutions of the Euler equation if they locally satisfy a scaling property of their second-order structure function. The conditions imposed are far away from boundaries, and wild solutions of Euler equations are not a priori excluded in the limit.

On the adiabatic limit of Hadamard states

NASA Astrophysics Data System (ADS)

Drago, Nicolò; Gérard, Christian

2017-08-01

We consider the adiabatic limit of Hadamard states for free quantum Klein-Gordon fields, when the background metric and the field mass are slowly varied from their initial to final values. If the Klein-Gordon field stays massive, we prove that the adiabatic limit of the initial vacuum state is the (final) vacuum state, by extending to the symplectic framework the adiabatic theorem of Avron-Seiler-Yaffe. In cases when only the field mass is varied, using an abstract version of the mode decomposition method we can also consider the case when the initial or final mass vanishes, and the initial state is either a thermal state or a more general Hadamard state.

Tachyon cosmology with non-vanishing minimum potential: a unified model

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

Li, Huiquan, E-mail: hqli@ustc.edu.cn

2012-07-01

We investigate the tachyon condensation process in the effective theory with non-vanishing minimum potential and its implications to cosmology. It is shown that the tachyon condensation on an unstable three-brane described by this modified tachyon field theory leads to lower-dimensional branes (defects) forming within a stable three-brane. Thus, in the cosmological background, we can get well-behaved tachyon matter after tachyon inflation, (partially) avoiding difficulties encountered in the original tachyon cosmological models. This feature also implies that the tachyon inflated and reheated universe is followed by a Chaplygin gas dark matter and dark energy universe. Hence, such an unstable three-brane behavesmore » quite like our universe, reproducing the key features of the whole evolutionary history of the universe and providing a unified description of inflaton, dark matter and dark energy in a very simple single-scalar field model.« less

LETTER TO THE EDITOR: Solving the Kadomtsev - Petviashvili equation with initial data not vanishing at large distances

NASA Astrophysics Data System (ADS)

Boiti, M.; Pempinelli, F.; Pogrebkov, A.

1997-06-01

We consider, in the framework of the inverse scattering method, the solution of the Kadomtsev - Petviashvili equation in its version called KPI. The spectral theory is extended to the case in which the initial data 0266-5611/13/3/001/img1 are not vanishing along a finite number of directions at large distances on the plane.

[Clinicopathologic features of drug-induced vanishing bile duct syndrome].

PubMed

Ye, L H; Wang, C K; Zhang, H C; Liu, Z Q; Zheng, H W

2017-04-20

Vanishing bile duct syndrome (VBDS) manifests as progressive destruction and disappearance of the intrahepatic bile duct caused by various factors and cholestasis. VBDS associated with drug-induced liver injury (D-VBDS) is an important etiology of VBDS, and immune disorder or immune imbalance may be the main pathogenesis. According to its clinical symptoms, serological markers, and course of the disease, D-VBDS is classified into major form and minor form, and its clinical features are based on various pathomorphological findings. Its prognosis is associated various factors including regeneration of bile duct cells, number of bile duct injuries, level and range of bile duct injury, bile duct proliferation, and compensatory shunt of bile duct branches. This disease has various clinical outcomes; most patients have good prognosis after drug withdrawal, and some patients may experience cholestatic cirrhosis, liver failure, and even death. Due to the clinical manifestation and biochemical changes are similar to the primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), it need to identify by clinical physician.

Vanishing bronchus intermedius syndrome in a pediatric patient with cystic fibrosis after lung transplantation.

PubMed

Hayes, Don; Mansour, Heidi M

2012-12-01

Airway complications occur frequently after lung transplantation. Bronchial stenosis is the most frequently encountered complication with the most severe form of that being the vanishing bronchus intermedius syndrome (VBIS). This rare disorder has never been reported in the pediatric population. This is the first report of VBIS in a pediatric patient, specifically a 16-yr-old male patient with cystic fibrosis whose course was complicated by a lower airway infection with Aspergillus fumigatus. The VBIS responded to bronchoscopic balloon dilation and placement of an airway stent. © 2012 John Wiley & Sons A/S.

De Rham-Hodge decomposition and vanishing of harmonic forms by derivation operators on the Poisson space

NASA Astrophysics Data System (ADS)

Privault, Nicolas

2016-05-01

We construct differential forms of all orders and a covariant derivative together with its adjoint on the probability space of a standard Poisson process, using derivation operators. In this framewok we derive a de Rham-Hodge-Kodaira decomposition as well as Weitzenböck and Clark-Ocone formulas for random differential forms. As in the Wiener space setting, this construction provides two distinct approaches to the vanishing of harmonic differential forms.

Vanishing Hall conductance in the phase-glass Bose metal at zero temperature

NASA Astrophysics Data System (ADS)

May-Mann, Julian; Phillips, Philip W.

2018-01-01

Motivated in part by numerical simulations [H. G. Katzgraber and A. P. Young, Phys. Rev. B 66, 224507 (2002), 10.1103/PhysRevB.66.224507; J. M. Kosterlitz and N. Akino, Phys. Rev. Lett. 81, 4672 (1998), 10.1103/PhysRevLett.81.4672; Phys. Rev. Lett. 81, 4672 (1998), 10.1103/PhysRevLett.81.4672] that reveal that the energy to create a defect in a gauge or phase glass scales as Lθ with θ <0 for two dimensions, thereby implying a vanishing stiffness, we reexamine the relevance of these kinds of models to the Bose metal in light of the new experiments [N. P. Breznay and Kapitulnik (unpublished); Y. Wang, I. Tamir, D. Shahar, and N. P. Armitage, arXiv:1708.01908 [cond-mat.supr-con

A comparison of automatic and intentional instructions when using the method of vanishing cues in acquired brain injury.

PubMed

Riley, Gerard A; Venn, Paul

2015-01-01

Thirty-four participants with acquired brain injury learned word lists under two forms of vanishing cues - one in which the learning trial instructions encouraged intentional retrieval (i.e., explicit memory) and one in which they encouraged automatic retrieval (which encompasses implicit memory). The automatic instructions represented a novel approach in which the cooperation of participants was actively sought to avoid intentional retrieval. Intentional instructions resulted in fewer errors during the learning trials and better performance on immediate and delayed retrieval tests. The advantage of intentional over automatic instructions was generally less for those who had more severe memory and/or executive impairments. Most participants performed better under intentional instructions on both the immediate and the delayed tests. Although those who were more severely impaired in both memory and executive function also did better with intentional instructions on the immediate retrieval test, they were significantly more likely to show an advantage for automatic instructions on the delayed test. It is suggested that this pattern of results may reflect impairments in the consolidation of intentional memories in this group. When using vanishing cues, automatic instructions may be better for those with severe consolidation impairments, but otherwise intentional instructions may be better.

Vanishing point: Scale independence in geomorphological hierarchies

NASA Astrophysics Data System (ADS)

Phillips, Jonathan D.

2016-08-01

Scale linkage problems in geosciences are often associated with a hierarchy of components. Both dynamical systems perspectives and intuition suggest that processes or relationships operating at fundamentally different scales are independent with respect to influences on system dynamics. But how far apart is ;fundamentally different;-that is, what is the ;vanishing point; at which scales are no longer interdependent? And how do we reconcile that with the idea (again, supported by both theory and intuition) that we can work our way along scale hierarchies from microscale to planetary (and vice-versa)? Graph and network theory are employed here to address these questions. Analysis of two archetypal hierarchical networks shows low algebraic connectivity, indicating low levels of inferential synchronization. This explains the apparent paradox between scale independence and hierarchical linkages. Incorporating more hierarchical levels results in an increase in complexity or entropy of the network as a whole, but at a nonlinear rate. Complexity increases as a power α of the number of levels in the hierarchy, with α < 1 and usually ≤ 0.6. However, algebraic connectivity decreases at a more rapid rate. Thus, the ability to infer one part of the hierarchical network from other level decays rapidly as more levels are added. Relatedness among system components decreases with differences in scale or resolution, analogous to distance decay in the spatial domain. These findings suggest a strategy of identifying and focusing on the most important or interesting scale levels, rather than attempting to identify the smallest or largest scale levels and work top-down or bottom-up from there. Examples are given from soil geomorphology and karst flow networks.

Can increases in capillarization explain the early adaptations in metabolic regulation in human muscle to short-term training?

PubMed

Green, Howard J; Burnett, Margaret; Kollias, Helen; Ouyang, Jing; Smith, Ian; Tupling, Susan

2012-05-01

To investigate the hypothesis that increases in fibre capillary density would precede increases in oxidative potential following training onset, tissue was extracted from the vastus lateralis prior to (0 days) and following 3 and 6 consecutive days of submaximal cycle exercise (2 h·day(-1)). Participants were untrained males (age = 21.4 ± 0.58 years; peak oxygen consumption = 46.2 ± 1.6 mL·kg(-1)·min(-1); mean ± standard error (SE)). Tissue was assessed for succinic dehydrogenase activity (SDH) by microphotometry and indices of capillarization based on histochemically assessed area and capillary counts (CC) in specific fibre types. Three days of training (n = 13) resulted in a generalized decrease (p < 0.05) in fibre area (-14.2% ± 3.0%; mean ± SE) and increase (p < 0.05) in CC/Area (20.4% ± 2.7%) and no change in either CC or SDH activity. Following 6 days of treatment (n = 6), increases (p < 0.05) in CC (18.2% ± 4.2%), CC/Area (28.9% ± 3.2%), and SDH activity (22.9% ± 6.0%) occurred that was not specific to major fibre type. No changes in either fibre area or fibre-type distribution were observed with additional training. We conclude that increases in angiogenic-based capillary density and oxidative potential occur coincidentally following training onset, while increases in capillary density, mediated by reductions in fibre area, represent an initial isolated response, the significance of which may be linked to the metabolic alterations that also result.

The Lagrangian Multiplier Method of Finding Upper and Lower Limits to Critical Stresses of Clamped Plates

DTIC Science & Technology

1946-01-01

geometrica ~ boundary condi- tions of the problem. (2) The energy of the load-plate system is computed for this deflection surface and is then minimized...and interpolating to find the k that makes the seriw vanish. The correct value of m is that which gives the lowest value of k. For two half waves (m=2...the square plate, the present rekdively simple upper- and lower-limit calcula- tions show that his est,imatd limit of error is correct for this case

Dynamical vanishing of the order parameter in a confined Bardeen-Cooper-Schrieffer Fermi gas after an interaction quench

NASA Astrophysics Data System (ADS)

Hannibal, S.; Kettmann, P.; Croitoru, M. D.; Axt, V. M.; Kuhn, T.

2018-01-01

We present a numerical study of the Higgs mode in an ultracold confined Fermi gas after an interaction quench and find a dynamical vanishing of the superfluid order parameter. Our calculations are done within a microscopic density-matrix approach in the Bogoliubov-de Gennes framework which takes the three-dimensional cigar-shaped confinement explicitly into account. In this framework, we study the amplitude mode of the order parameter after interaction quenches starting on the BCS side of the BEC-BCS crossover close to the transition and ending in the BCS regime. We demonstrate the emergence of a dynamically vanishing superfluid order parameter in the spatiotemporal dynamics in a three-dimensional trap. Further, we show that the signal averaged over the whole trap mirrors the spatiotemporal behavior and allows us to systematically study the effects of the system size and aspect ratio on the observed dynamics. Our analysis enables us to connect the confinement-induced modifications of the dynamics to the pairing properties of the system. Finally, we demonstrate that the signature of the Higgs mode is contained in the dynamical signal of the condensate fraction, which, therefore, might provide a new experimental access to the nonadiabatic regime of the Higgs mode.

Incoherent Scatterer in a Luttinger Liquid: A New Paradigmatic Limit

NASA Astrophysics Data System (ADS)

Altland, Alexander; Gefen, Yuval; Rosenow, Bernd

2012-03-01

We address the problem of a Luttinger liquid with a scatterer that allows for both coherent and incoherent scattering channels. The asymptotic behavior at zero temperature is governed by a new stable fixed point: A Goldstone mode dominates the low energy dynamics, leading to universal behavior. This limit is marked by equal probabilities for forward and backward scattering. Notwithstanding this nontrivial scattering pattern, we find that the shot noise as well as cross-current correlations vanish. We thus present a paradigmatic picture of an impurity in the Luttinger model, alternative to the Kane-Fisher picture.

The ball vanishes in the air: can we blame representational momentum?

PubMed

Thomas, Cyril; Didierjean, André

2016-12-01

In the vanishing ball illusion (VBI), the magician throws a ball up into the air twice and then pretends to do a third throw. On the third (fake) throw, the audience sees the ball go up and then disappear. In this article, we study the psychological mechanisms at play in this magic trick. We test the hypothesis that the illusion is based on representational momentum (RM), a psychological phenomenon in which the observer perceives the stopping point of a moving scene as being located farther ahead in the direction of motion than it really is. To determine whether the mechanisms involved in VBI are similar to those underlying RM, we compared the results of a standard VBI task to those obtained on an RM task designed to be very close to the VBI task. The results showed that VBI sensitivity was not associated with a higher anticipation score on the RM task. Unexpectedly, we found that participants who were sensitive to the illusion even obtained a weaker RM effect. We discuss several hypotheses that might account for these results.

Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

NASA Astrophysics Data System (ADS)

Adame, J.; Warzel, S.

2015-11-01

In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM.

Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

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

Adame, J.; Warzel, S., E-mail: warzel@ma.tum.de

In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM.

Limit cycles and conformal invariance

NASA Astrophysics Data System (ADS)

Fortin, Jean-François; Grinstein, Benjamín; Stergiou, Andreas

2013-01-01

There is a widely held belief that conformal field theories (CFTs) require zero beta functions. Nevertheless, the work of Jack and Osborn implies that the beta functions are not actually the quantites that decide conformality, but until recently no such behavior had been exhibited. Our recent work has led to the discovery of CFTs with nonzero beta functions, more precisely CFTs that live on recurrent trajectories, e.g., limit cycles, of the beta-function vector field. To demonstrate this we study the S function of Jack and Osborn. We use Weyl consistency conditions to show that it vanishes at fixed points and agrees with the generator Q of limit cycles on them. Moreover, we compute S to third order in perturbation theory, and explicitly verify that it agrees with our previous determinations of Q. A byproduct of our analysis is that, in perturbation theory, unitarity and scale invariance imply conformal invariance in four-dimensional quantum field theories. Finally, we study some properties of these new, "cyclic" CFTs, and point out that the a-theorem still governs the asymptotic behavior of renormalization-group flows.

Prevalences and pregnancy outcome of vanishing twin pregnancies achieved by in vitro fertilization versus natural conception.

PubMed

Márton, Virág; Zádori, János; Kozinszky, Zoltan; Keresztúri, Attila

2016-11-01

To evaluate whether vanishing twin (VT) pregnancies achieved by in vitro fertilization and intracytoplasmic sperm injection (IVF-ICSI) had a more adverse perinatal outcome than those after natural conception. Longitudinal, retrospective cohort study. Tertiary university hospital. Three hundred and six (78 after IVF-ICSI and 228 after natural conception) VT pregnancies over a 22-year period, with VT cases matched to primarily singleton controls. None. Obstetric and neonatal outcome data. The incidence of VT was statistically significantly higher after natural conception (18.2% of twins) than after IVF-ICSI (12.6% of twins). The odds of VT in pregnancies complicated with pregestational or gestational diabetes were disproportionally higher in IVF-ICSI cases than in spontaneously conceived VT pregnancies (adjusted odds ratio [AOR]: 0.80 vs. 3.10 and 1.00 vs. 1.07, respectively). Previous induced abortion (AOR 1.34) or second-trimester fetal loss (AOR 3.3) increased the risk of VT pregnancies after spontaneous conception. Gestational diabetes mellitus in both the previous (AOR 5.41) and the present (AOR 2.3) pregnancy as well as chronic maternal diseases (AOR 3.5) and placentation anomalies all represented independent risk factors for VT after IVF-ICSI. Vanishing twin pregnancies had a lower prevalence and a worse perinatal outcome after IVF-ICSI as compared with those of their spontaneously conceived counterparts. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Vanishing amplitude of backbone dynamics causes a true protein dynamical transition: H2 NMR studies on perdeuterated C-phycocyanin

NASA Astrophysics Data System (ADS)

Kämpf, Kerstin; Kremmling, Beke; Vogel, Michael

2014-03-01

Using a combination of H2 nuclear magnetic resonance (NMR) methods, we study internal rotational dynamics of the perdeuterated protein C-phycocyanin (CPC) in dry and hydrated states over broad temperature and dynamic ranges with high angular resolution. Separating H2 NMR signals from methyl deuterons, we show that basically all backbone deuterons exhibit highly restricted motion occurring on time scales faster than microseconds. The amplitude of this motion increases when a hydration shell exists, while it decreases upon cooling and vanishes near 175 K. We conclude that the vanishing of the highly restricted motion marks a dynamical transition, which is independent of the time window and of a fundamental importance. This conclusion is supported by results from experimental and computational studies of the proteins myoglobin and elastin. In particular, we argue based on findings in molecular dynamics simulations that the behavior of the highly restricted motion of proteins at the dynamical transition resembles that of a characteristic secondary relaxation of liquids at the glass transition, namely the nearly constant loss. Furthermore, H2 NMR studies on perdeuterated CPC reveal that, in addition to highly restricted motion, small fractions of backbone segments exhibit weakly restricted dynamics when temperature and hydration are sufficiently high.

Homogenization limit for a multiband effective mass model in heterostructures

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

Morandi, O., E-mail: morandi@ipcms.unistra.fr

We study the homogenization limit of a multiband model that describes the quantum mechanical motion of an electron in a quasi-periodic crystal. In this approach, the distance among the atoms that constitute the material (lattice parameter) is considered a small quantity. Our model include the description of materials with variable chemical composition, intergrowth compounds, and heterostructures. We derive the effective multiband evolution system in the framework of the kp approach. We study the well posedness of the mathematical problem. We compare the effective mass model with the standard kp models for uniform and non-uniforms crystals. We show that in themore » limit of vanishing lattice parameter, the particle density obtained by the effective mass model, converges to the exact probability density of the particle.« less

Exercise training during chemotherapy preserves skeletal muscle fiber area, capillarization, and mitochondrial content in patients with breast cancer.

PubMed

Mijwel, Sara; Cardinale, Daniele A; Norrbom, Jessica; Chapman, Mark; Ivarsson, Niklas; Wengström, Yvonne; Sundberg, Carl Johan; Rundqvist, Helene

2018-05-11

Exercise has been suggested to ameliorate the detrimental effects of chemotherapy on skeletal muscle. The aim of this study was to compare the effects of different exercise regimens with usual care on skeletal muscle morphology and mitochondrial markers in patients being treated with chemotherapy for breast cancer. Specifically, we compared moderate-intensity aerobic training combined with high-intensity interval training (AT-HIIT) and resistance training combined with high-intensity interval training (RT-HIIT) with usual care (UC). Resting skeletal muscle biopsies were obtained pre- and postintervention from 23 randomly selected women from the OptiTrain breast cancer trial who underwent RT-HIIT, AT-HIIT, or UC for 16 wk. Over the intervention, citrate synthase activity, muscle fiber cross-sectional area, capillaries per fiber, and myosin heavy chain isoform type I were reduced in UC, whereas RT-HIIT and AT-HIIT were able to counteract these declines. AT-HIIT promoted up-regulation of the electron transport chain protein levels vs. UC. RT-HIIT favored satellite cell count vs. UC and AT-HIIT. There was a significant association between change in citrate synthase activity and self-reported fatigue. AT-HIIT and RT-HIIT maintained or improved markers of skeletal muscle function compared with the declines found in the UC group, indicating a sustained trainability in addition to the preservation of skeletal muscle structural and metabolic characteristics during chemotherapy. These findings highlight the importance of supervised exercise programs for patients with breast cancer during chemotherapy.-Mijwel, S., Cardinale, D. A., Norrbom, J., Chapman, M., Ivarsson, N., Wengström, Y., Sundberg, C. J., Rundqvist, H. Exercise training during chemotherapy preserves skeletal muscle fiber area, capillarization, and mitochondrial content in patients with breast cancer.

Spreading and vanishing in a West Nile virus model with expanding fronts

NASA Astrophysics Data System (ADS)

Tarboush, Abdelrazig K.; Lin, ZhiGui; Zhang, MengYun

2017-05-01

In this paper, we study a simplified version of a West Nile virus model discussed by Lewis et al. [28], which was considered as a first approximation for the spatial spread of WNv. The basic reproduction number $R_0$ for the non-spatial epidemic model is defined and a threshold parameter $R_0 ^D$ for the corresponding problem with null Dirichlet boundary condition is introduced. We consider a free boundary problem with coupled system, which describes the diffusion of birds by a PDE and the movement of mosquitoes by a ODE. The risk index $R_0^F (t)$ associated with the disease in spatial setting is represented. Sufficient conditions for the WNv to eradicate or to spread are given. The asymptotic behavior of the solution to system when the spreading occurs are considered. It is shown that the initial number of infected populations, the diffusion rate of birds and the length of initial habitat exhibit important impacts on the vanishing or spreading of the virus. Numerical simulations are presented to illustrate the analytical results.

Spreading-vanishing dichotomy in a diffusive logistic model with a free boundary, II

NASA Astrophysics Data System (ADS)

Du, Yihong; Guo, Zongming

We study the diffusive logistic equation with a free boundary in higher space dimensions and heterogeneous environment. Such a model may be used to describe the spreading of a new or invasive species, with the free boundary representing the expanding front. For simplicity, we assume that the environment and the solution are radially symmetric. In the special case of one space dimension and homogeneous environment, this free boundary problem was investigated in Du and Lin (2010) [10]. We prove that the spreading-vanishing dichotomy established in Du and Lin (2010) [10] still holds in the more general and ecologically realistic setting considered here. Moreover, when spreading occurs, we obtain best possible upper and lower bounds for the spreading speed of the expanding front. When the environment is asymptotically homogeneous at infinity, these two bounds coincide. Our results indicate that the asymptotic spreading speed determined by this model does not depend on the spatial dimension.

Periodic three-body orbits with vanishing angular momentum in the Jacobi-Poincaré ‘strong’ potential

NASA Astrophysics Data System (ADS)

Dmitrašinović, V.; Petrović, Luka V.; Šuvakov, Milovan

2017-10-01

Moore (1993 Phys. Rev. Lett. 70 3675) and Montgomery (2005 Ergod. Theor. Dynam. Syst. 25 921-947) have argued that planar periodic orbits of three bodies moving in the Jacobi-Poincaré, or the ‘strong’ pairwise potential \\sumi>j\\frac{-1}{rij^2} , can have all possible topologies. Here we search systematically for such orbits with vanishing angular momentum and find 24 topologically distinct orbits, 22 of which are new, in a small section of the allowed phase space, with a tendency to overcrowd, due to overlapping initial conditions. The topologies of these 24 orbits belong to three algebraic sequences defined as functions of integer n=0, 1, 2, \\ldots . Each sequence extends to n \\to ∞ , but the separation of initial conditions for orbits with n ≥slant 10 becomes practically impossible with a numerical precision of 16 decimal places. Nevertheless, even with a precision of 16 decimals, it is clear that in each sequence both the orbit’s initial angle φn and its period T n approach finite values in the asymptotic limit (n \\to ∞ ). Two of three sequences are overlapping in the sense that their initial angles ϕ occupy the same segment on the circle and their asymptotic values φ∞ are (very) close to each other. The actions of these orbits rise linearly with the index n that describes the orbit’s topology, which is in agreement with the Newtonian case. We show that this behaviour is consistent with the assumption of analyticity of the action as a function of period.

Concentration and limit behaviors of stationary measures

NASA Astrophysics Data System (ADS)

Huang, Wen; Ji, Min; Liu, Zhenxin; Yi, Yingfei

2018-04-01

In this paper, we study limit behaviors of stationary measures of the Fokker-Planck equations associated with a system of ordinary differential equations perturbed by a class of multiplicative noise including additive white noise case. As the noises are vanishing, various results on the invariance and concentration of the limit measures are obtained. In particular, we show that if the noise perturbed systems admit a uniform Lyapunov function, then the stationary measures form a relatively sequentially compact set whose weak∗-limits are invariant measures of the unperturbed system concentrated on its global attractor. In the case that the global attractor contains a strong local attractor, we further show that there exists a family of admissible multiplicative noises with respect to which all limit measures are actually concentrated on the local attractor; and on the contrary, in the presence of a strong local repeller in the global attractor, there exists a family of admissible multiplicative noises with respect to which no limit measure can be concentrated on the local repeller. Moreover, we show that if there is a strongly repelling equilibrium in the global attractor, then limit measures with respect to typical families of multiplicative noises are always concentrated away from the equilibrium. As applications of these results, an example of stochastic Hopf bifurcation and an example with non-decomposable ω-limit sets are provided. Our study is closely related to the problem of noise stability of compact invariant sets and invariant measures of the unperturbed system.

Proteomics-level analysis of myelin formation and regeneration in a mouse model for Vanishing White Matter disease.

PubMed

Gat-Viks, Irit; Geiger, Tamar; Barbi, Mali; Raini, Gali; Elroy-Stein, Orna

2015-08-01

Vanishing white matter (VWM) is a recessive neurodegenerative disease caused by mutations in translation initiation factor eIF2B and leading to progressive brain myelin deterioration, secondary axonal damage, and death in early adolescence. Eif2b5(R132H/R132H) mice exhibit delayed developmental myelination, mild early neurodegeneration and a robust remyelination defect in response to cuprizone-induced demyelination. In the current study we used Eif2b5(R132H/R132H) mice for mass-spectrometry analyses, to follow the changes in brain protein abundance in normal- versus cuprizone-diet fed mice during the remyelination recovery phase. Analysis of proteome profiles suggested that dysregulation of mitochondrial functions, altered proteasomal activity and impaired balance between protein synthesis and degradation play a role in VWM pathology. Consistent with these findings, we detected elevated levels of reactive oxygen species in mutant-derived primary fibroblasts and reduced 20S proteasome activity in mutant brain homogenates. These observations highlight the importance of tight translational control to precise coordination of processes involved in myelin formation and regeneration and point at cellular functions that may contribute to VWM pathology. Eif2b5(R132H/R132H) mouse model for vanishing white matter (VWM) disease was used for mass spectrometry of brain proteins at two time points under normal conditions and along recovery from cuprizone-induced demyelination. Comparisons of proteome profiles revealed the importance of mitochondrial function and tight coordination between protein synthesis and degradation to myelination formation and regeneration, pointing at cellular functions that contribute to VWM pathology. © 2015 International Society for Neurochemistry.

Vanishing honey bees: Is the dying of adult worker bees a consequence of short telomeres and premature aging?

PubMed

Stindl, Reinhard; Stindl, Wolfgang

2010-10-01

Einstein is often quoted to have said that without the bee, mankind would have but 4years to live. It is highly unlikely that he made this comment, which was even mentioned in a Lancet article on honey bees. However, the current vanishing of the bees can have serious consequences for human health, because 35% of the human diet is thought to benefit from pollination. Colony collapse disorder (CCD) in honey bees is characterized by the rapid decline of the adult bee population, leaving the brood and the queen poorly or completely unattended, with no dead bodies in or around the hive. A large study found no evidence that the presence or amount of any individual pesticide or infectious agent occurred more frequently or abundantly in CCD-affected colonies. The growing consensus is that honey bees are suffering from comprised immune systems, which allow various infectious pathogens to invade. The question remains, what causes immunosuppression in many colonies of Apis mellifera in North America and Europe? Telomeres are protective DNA structures located at eukaryotic chromosome tips that shorten in the somatic tissues of animals with age. Lifelong tissue regeneration takes place in Apis mellifera, and worker bees have been shown to senesce. In humans, a vast amount of literature has accumulated on exhausted telomere reserves causing impaired tissue regeneration and age-associated diseases, specifically cancer and immunosuppression. Therefore, we propose a new causative mechanism for the vanishing of the bees: critically short telomeres in long-lived winter bees. We term this the telomere premature aging syndrome. Copyright 2010 Elsevier Ltd. All rights reserved.

New limits on neutrino magnetic moment through nonvanishing 13-mixing

NASA Astrophysics Data System (ADS)

Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.

2018-05-01

The relatively large value of the neutrino mixing angle θ13 set by recent measurements allows us to use solar neutrinos to set a limit on the neutrino magnetic moment involving the second and third flavor families, μ23. The existence of a random magnetic field in the solar convective zone can produce a significant antineutrino flux when a nonvanishing neutrino magnetic moment is assumed. Even if we consider a vanishing neutrino magnetic moment involving the first family, electron antineutrinos are indirectly produced through the mixing between the first and third families and μ23≠0 . Using KamLAND limits on the solar flux of electron antineutrino, we set the limit μ23<0.95 ×10-11μB as a reasonable assumption on the behavior of solar magnetic fields. This is the first time that a limit on μ23 has been established in the literature directly from neutrino interactions with magnetic fields, and, interestingly enough, is comparable with the limits on the neutrino magnetic moment involving the first family and with the ones coming from modifications to the electroweak cross section.

The limits of the Bohm criterion in collisional plasmas

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

Valentini, H.-B.; Kaiser, D.

2015-05-15

The sheath formation within a low-pressure collisional plasma is analysed by means of a two-fluid model. The Bohm criterion takes into account the effects of the electric field and the inertia of the ions. Numerical results yield that these effects contribute to the space charge formation, only, if the collisionality is lower than a relatively small threshold. It follows that a lower and an upper limit of the drift speed of the ions exist where the effects treated by Bohm can form a sheath. This interval becomes narrower as the collisionality increases and vanishes at the mentioned threshold. Above themore » threshold, the sheath is mainly created by collisions and the ionisation. Under these conditions, the sheath formation cannot be described by means of Bohm like criteria. In a few references, a so-called upper limit of the Bohm criterion is stated for collisional plasmas where the momentum equation of the ions is taken into account, only. However, the present paper shows that this limit results in an unrealistically steep increase of the space charge density towards the wall, and, therefore, it yields no useful limit of the Bohm velocity.« less

Characteristics of early MRI in children and adolescents with vanishing white matter.

PubMed

van der Lei, Hannemieke D; Steenweg, Marjan E; Barkhof, Frederik; de Grauw, Ton; d'Hooghe, Marc; Morton, Richard; Shah, Siddharth; Wolf, Nicole; van der Knaap, Marjo S

2012-02-01

MRI in vanishing white matter typically shows diffuse abnormality of the cerebral white matter, which becomes increasingly rarefied and cystic. We investigated the MRI characteristics preceding this stage. In a retrospective observational study, we evaluated all available MRIs in our database of DNA-confirmed VWM patients and selected MRIs without diffuse cerebral white matter abnormalities and without signs of rarefaction or cystic degeneration in patients below 20 years of age. A previously established scoring list was used to evaluate the MRIs. An MRI of seven patients fulfilled the criteria. All had confluent and symmetrical abnormalities in the periventricular and bordering deep white matter. In young patients, myelination was delayed. The inner rim of the corpus callosum was affected in all patients. In early stages of VWM, MRI does not necessarily display diffuse cerebral white matter involvement and rarefaction or cystic degeneration. If the MRI abnormalities do not meet the criteria for VWM, it helps to look at the corpus callosum. If the inner rim (the callosal-septal interface) is affected, VWM should be considered. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Thermodynamic limit and boundary energy of the su(3) spin chain with non-diagonal boundary fields

NASA Astrophysics Data System (ADS)

Wen, Fakai; Yang, Tao; Yang, Zhanying; Cao, Junpeng; Hao, Kun; Yang, Wen-Li

2017-02-01

We investigate the thermodynamic limit of the su (n)-invariant spin chain models with unparallel boundary fields. It is found that the contribution of the inhomogeneous term in the associated T-Q relation to the ground state energy does vanish in the thermodynamic limit. This fact allows us to calculate the boundary energy of the system. Taking the su (2) (or the XXX) spin chain and the su (3) spin chain as concrete examples, we have studied the corresponding boundary energies of the models. The method used in this paper can be generalized to study the thermodynamic properties and boundary energy of other high rank models with non-diagonal boundary fields.

A Vanishing Star Revisited

NASA Astrophysics Data System (ADS)

1999-07-01

VLT Observations of an Unusual Stellar System Reinhold Häfner of the Munich University Observatory (Germany) is a happy astronomer. In 1988, when he was working at a telescope at the ESO La Silla observatory, he came across a strange star that suddenly vanished off the computer screen. He had to wait for more than a decade to get the full explanation of this unusual event. On June 10-11, 1999, he observed the same star with the first VLT 8.2-m Unit Telescope (ANTU) and the FORS1 astronomical instrument at Paranal [1]. With the vast power of this new research facility, he was now able to determine the physical properties of a very strange stellar system in which two planet-size stars orbit each other. One is an exceedingly hot white dwarf star , weighing half as much as the Sun, but only twice as big as the Earth. The other is a much cooler and less massive red dwarf star , one-and-a-half times the size of planet Jupiter. Once every three hours, the hot star disappears behind the other, as seen from the Earth. For a few minutes, the brightness of the system drops by a factor of more than 250 and it "vanishes" from view in telescopes smaller than the VLT. A variable star named NN Serpentis ESO PR Photo 30a/99 ESO PR Photo 30a/99 [Preview - JPEG: 400 x 468 pix - 152k] [Normal - JPEG: 800 x 936 pix - 576k] [High-Res - JPEG: 2304 x 2695 pix - 4.4M] Caption to ESO PR Photo 30a/99 : The sky field around the 17-mag variable stellar system NN Serpentis , as seen in a 5 sec exposure through a V(isual) filter with VLT ANTU and FORS1. It was obtained just before the observation of an eclipse of this unsual object and served to centre the telescope on the corresponding sky position. The field shown here measures 4.5 x 4.5 armin 2 (1365 x 1365 pix 2 ; 0.20 arcsec/pix). The field is somewhat larger than that shown in Photo 30b/99 and has the same orientation to allow comparison: North is about 20° anticlockwise from the top and East is 90° clockwise from that direction. The

Acquisition of 3d Information for Vanished Structure by Using Only AN Ancient Picture

NASA Astrophysics Data System (ADS)

Kunii, Y.; Sakamoto, R.

2016-06-01

In order to acquire 3D information for reconstruction of vanished historical structure, grasp of 3D shape of such structure was attempted by using an ancient picture. Generally, 3D information of a structure is acquired by photogrammetric theory which requires two or more pictures. This paper clarifies that the geometrical information of the structure was obtained only from an ancient picture, and 3D information was acquired. This kind of method was applied for an ancient picture of the Old Imperial Theatre. The Old Imperial Theatre in the picture is constituted by two-point perspective. Therefore, estimated value of focal length of camera, length of camera to the Old Imperial Theatre and some parameters were calculated by estimation of field angle, using body height as an index of length and some geometrical information. Consequently, 3D coordinate of 120 measurement points on the surface of the Old Imperial Theatre were calculated respectively, and 3DCG modeling of the Old Imperial Theatre was realized.

A notable difference between ideal gas and infinite molar volume limit of van der Waals gas

NASA Astrophysics Data System (ADS)

Liu, Q. H.; Shen, Y.; Bai, R. L.; Wang, X.

2010-05-01

The van der Waals equation of state does not sufficiently represent a gas unless a thermodynamic potential with two proper and independent variables is simultaneously determined. The limiting procedures under which the behaviour of the van der Waals gas approaches that of an ideal gas are letting two van der Waals coefficients be zero rather than letting the molar volume become infinitely large; otherwise, the partial derivative of internal energy with respect to pressure at a fixed temperature does not vanish.

Crossmodal Connections of Primary Sensory Cortices Largely Vanish During Normal Aging

PubMed Central

Henschke, Julia U.; Ohl, Frank W.; Budinger, Eike

2018-01-01

During aging, human response times (RTs) to unisensory and crossmodal stimuli decrease. However, the elderly benefit more from crossmodal stimulus representations than younger people. The underlying short-latency multisensory integration process is mediated by direct crossmodal connections at the level of primary sensory cortices. We investigate the age-related changes of these connections using a rodent model (Mongolian gerbil), retrograde tracer injections into the primary auditory (A1), somatosensory (S1), and visual cortex (V1), and immunohistochemistry for markers of apoptosis (Caspase-3), axonal plasticity (Growth associated protein 43, GAP 43), and a calcium-binding protein (Parvalbumin, PV). In adult animals, primary sensory cortices receive a substantial number of direct thalamic inputs from nuclei of their matched, but also from nuclei of non-matched sensory modalities. There are also direct intracortical connections among primary sensory cortices and connections with secondary sensory cortices of other modalities. In very old animals, the crossmodal connections strongly decrease in number or vanish entirely. This is likely due to a retraction of the projection neuron axonal branches rather than ongoing programmed cell death. The loss of crossmodal connections is also accompanied by changes in anatomical correlates of inhibition and excitation in the sensory thalamus and cortex. Together, the loss and restructuring of crossmodal connections during aging suggest a shift of multisensory processing from primary cortices towards other sensory brain areas in elderly individuals. PMID:29551970

Crossmodal Connections of Primary Sensory Cortices Largely Vanish During Normal Aging.

PubMed

Henschke, Julia U; Ohl, Frank W; Budinger, Eike

2018-01-01

During aging, human response times (RTs) to unisensory and crossmodal stimuli decrease. However, the elderly benefit more from crossmodal stimulus representations than younger people. The underlying short-latency multisensory integration process is mediated by direct crossmodal connections at the level of primary sensory cortices. We investigate the age-related changes of these connections using a rodent model (Mongolian gerbil), retrograde tracer injections into the primary auditory (A1), somatosensory (S1), and visual cortex (V1), and immunohistochemistry for markers of apoptosis (Caspase-3), axonal plasticity (Growth associated protein 43, GAP 43), and a calcium-binding protein (Parvalbumin, PV). In adult animals, primary sensory cortices receive a substantial number of direct thalamic inputs from nuclei of their matched, but also from nuclei of non-matched sensory modalities. There are also direct intracortical connections among primary sensory cortices and connections with secondary sensory cortices of other modalities. In very old animals, the crossmodal connections strongly decrease in number or vanish entirely. This is likely due to a retraction of the projection neuron axonal branches rather than ongoing programmed cell death. The loss of crossmodal connections is also accompanied by changes in anatomical correlates of inhibition and excitation in the sensory thalamus and cortex. Together, the loss and restructuring of crossmodal connections during aging suggest a shift of multisensory processing from primary cortices towards other sensory brain areas in elderly individuals.

High-order corrections on the laser cooling limit in the Lamb-Dicke regime.

PubMed

Yi, Zhen; Gu, Wen-Ju

2017-01-23

We investigate corrections on the cooling limit of high-order Lamb-Dicke (LD) parameters in the double electromagnetically induced transparency (EIT) cooling scheme. Via utilizing quantum interferences, the single-phonon heating mechanism vanishes and the system evolves to a double dark state, from which we will obtain the mechanical occupation on the single-phonon excitation state. In addition, the further correction induced by two-phonon heating transitions is included to achieve a more accurate cooling limit. There exist two pathways of two-phonon heating transitions: direct two-phonon excitation from the dark state and further excitation from the single-phonon excited state. By adding up these two parts of correction, the obtained analytical predictions show a well consistence with numerical results. Moreover, we find that the two pathways can destructively interfere with each other, leading to the elimination of two-phonon heating transitions and achieving a lower cooling limit.

Automated segmentation reveals silent radiographic progression in adult-onset vanishing white-matter disease.

PubMed

Huber, Thomas; Herwerth, Marina; Alberts, Esther; Kirschke, Jan S; Zimmer, Claus; Ilg, Ruediger

2017-02-01

Adult-onset vanishing white-matter disease (VWM) is a rare autosomal recessive disease with neurological symptoms such as ataxia and paraparesis, showing extensive white-matter hyperintensities (WMH) on magnetic resonance (MR) imaging. Besides symptom-specific scores like the International Cooperative Ataxia Rating Scale (ICARS), there is no established tool to monitor disease progression. Because of extensive WMH, visual comparison of MR images is challenging. Here, we report the results of an automated method of segmentation to detect alterations in T2-weighted fluid-attenuated-inversion-recovery (FLAIR) sequences in a one-year follow-up study of a clinically stable patient with genetically diagnosed VWM. Signal alterations in MR imaging were quantified with a recently published WMH segmentation method by means of extreme value distribution (EVD). Our analysis revealed progressive FLAIR alterations of 5.84% in the course of one year, whereas no significant WMH change could be detected in a stable multiple sclerosis (MS) control group. This result demonstrates that automated EVD-based segmentation allows a precise and rapid quantification of extensive FLAIR alterations like in VWM and might be a powerful tool for the clinical and scientific monitoring of degenerative white-matter diseases and potential therapeutic interventions.

Predicting Sediment Thickness on Vanished Ocean Crust Since 200 Ma

NASA Astrophysics Data System (ADS)

Dutkiewicz, A.; Müller, R. D.; Wang, X.; O'Callaghan, S.; Cannon, J.; Wright, N. M.

2017-12-01

Tracing sedimentation through time on existing and vanished seafloor is imperative for constraining long-term eustasy and for calculating volumes of subducted deep-sea sediments that contribute to global geochemical cycles. We present regression algorithms that incorporate the age of the ocean crust and the mean distance to the nearest passive margin to predict sediment thicknesses and long-term decompacted sedimentation rates since 200 Ma. The mean sediment thickness decreases from ˜220 m at 200 Ma to a minimum of ˜140 m at 130 Ma, reflecting the replacement of old Panthalassic ocean floor with young sediment-poor mid-ocean ridges, followed by an increase to ˜365 m at present-day. This increase reflects the accumulation of sediments on ageing abyssal plains proximal to passive margins, coupled with a decrease in the mean distance of any parcel of ocean crust to the nearest passive margin by over 700 km, and a doubling of the total passive margin length at present-day. Mean long-term sedimentation rates increase from ˜0.5 cm/ky at 160 Ma to over 0.8 cm/ky today, caused by enhanced terrigenous sediment influx along lengthened passive margins, superimposed by the onset of ocean-wide carbonate sedimentation. Our predictive algorithms, coupled to a plate tectonic model, provide a framework for constraining the seafloor sediment-driven eustatic sea-level component, which has grown from ˜80 to 210 m since 120 Ma. This implies a long-term sea-level rise component of 130 m, partly counteracting the contemporaneous increase in ocean basin depth due to progressive crustal ageing.

Chronic Inflammatory Demyelinating Polyneuropathy Variant with Creatine-Kinase Elevation and Vanishing Effect of Immunoglobulins.

PubMed

Finsterer, Josef; Aliyev, Rahim

2017-07-27

BACKGROUND Whether creatine-kinase (CK) is elevated or not in chronic inflammatory demyelinating polyneuropathy (CIDP) and its variants is not comprehensively investigated. CASE REPORT We report the case of a 47-year-old male who developed weakness of the left lower leg and the right index finger at age 42 years. At age 44 years, paresthesias and dysesthesias of both lower legs and mild right lower leg weakness additionally developed. CK was recurrently elevated since age 42 years but paraprotein and anti-myelin-associated glycoprotein (MAG)-antibodies were negative. Nerve conduction studies at age 43 years showed an axonal and demyelinating lesion with conduction blocks. Cerebrospinal fluid (CSF) investigations revealed mild pleocytosis and elevated protein, which is why CIDP variant was diagnosed. Immunoglobulins were administered with success. Because of recurrent relapses, immunoglobulins were increased at age 45 years, resulting in stabilization. Currently, the patient is infusing immunoglobulins subcutaneously himself. CONCLUSIONS CIDP variants may go along with CK elevation, an axonal lesion, pleocytosis, and asymmetry of the lesion. A vanishing effect of immunoglobulins over time may be characteristic of CIDP variants.

Hilbert's sixth problem and the failure of the Boltzmann to Euler limit

NASA Astrophysics Data System (ADS)

Slemrod, Marshall

2018-04-01

This paper addresses the main issue of Hilbert's sixth problem, namely the rigorous passage of solutions to the mesoscopic Boltzmann equation to macroscopic solutions of the Euler equations of compressible gas dynamics. The results of the paper are that (i) in general Hilbert's program will fail because of the appearance of van der Waals-Korteweg capillarity terms in a macroscopic description of motion of a gas, and (ii) the van der Waals-Korteweg theory itself might satisfy Hilbert's quest for a map from the `atomistic view' to the laws of motion of continua. This article is part of the theme issue `Hilbert's sixth problem'.

Refraction limit of miniaturized optical systems: a ball-lens example.

PubMed

Kim, Myun-Sik; Scharf, Toralf; Mühlig, Stefan; Fruhnert, Martin; Rockstuhl, Carsten; Bitterli, Roland; Noell, Wilfried; Voelkel, Reinhard; Herzig, Hans Peter

2016-04-04

We study experimentally and theoretically the electromagnetic field in amplitude and phase behind ball-lenses across a wide range of diameters, ranging from a millimeter scale down to a micrometer. Based on the observation, we study the transition between the refraction and diffraction regime. The former regime is dominated by observables for which it is sufficient to use a ray-optical picture for an explanation, e.g., a cusp catastrophe and caustics. A wave-optical picture, i.e. Mie theory, is required to explain the features, e.g., photonic nanojets, in the latter regime. The vanishing of the cusp catastrophe and the emergence of the photonic nanojet is here understood as the refraction limit. Three different criteria are used to identify the limit: focal length, spot size, and amount of cross-polarization generated in the scattering process. We identify at a wavelength of 642 nm and while considering ordinary glass as the ball-lens material, a diameter of approximately 10 µm as the refraction limit. With our study, we shed new light on the means necessary to describe micro-optical system. This is useful when designing optical devices for imaging or illumination.

Entropy production of a Brownian ellipsoid in the overdamped limit.

PubMed

Marino, Raffaele; Eichhorn, Ralf; Aurell, Erik

2016-01-01

We analyze the translational and rotational motion of an ellipsoidal Brownian particle from the viewpoint of stochastic thermodynamics. The particle's Brownian motion is driven by external forces and torques and takes place in an heterogeneous thermal environment where friction coefficients and (local) temperature depend on space and time. Our analysis of the particle's stochastic thermodynamics is based on the entropy production associated with single particle trajectories. It is motivated by the recent discovery that the overdamped limit of vanishing inertia effects (as compared to viscous fricion) produces a so-called "anomalous" contribution to the entropy production, which has no counterpart in the overdamped approximation, when inertia effects are simply discarded. Here we show that rotational Brownian motion in the overdamped limit generates an additional contribution to the "anomalous" entropy. We calculate its specific form by performing a systematic singular perturbation analysis for the generating function of the entropy production. As a side result, we also obtain the (well-known) equations of motion in the overdamped limit. We furthermore investigate the effects of particle shape and give explicit expressions of the "anomalous entropy" for prolate and oblate spheroids and for near-spherical Brownian particles.

Extending the limits of complex learning in organic amnesia: computer training in a vocational domain.

PubMed

Glisky, E L; Schacter, D L

1989-01-01

This study explored the limits of learning that could be achieved by an amnesic patient in a complex real-world domain. Using a cuing procedure known as the method of vanishing cues, a severely amnesic encephalitic patient was taught over 250 discrete pieces of new information concerning the rules and procedures for performing a task involving data entry into a computer. Subsequently, she was able to use this acquired knowledge to perform the task accurately and efficiently in the workplace. These results suggest that amnesic patients' preserved learning abilities can be extended well beyond what has been reported previously.

Vanishing bile duct syndrome in Hodgkin's lymphoma: A case report and literature review.

PubMed

Bakhit, Mena; McCarty, Thomas R; Park, Sunhee; Njei, Basile; Cho, Margaret; Karagozian, Raffi; Liapakis, AnnMarie

2017-01-14

Vanishing bile duct syndrome (VBDS) has been described in different pathologic conditions including infection, ischemia, adverse drug reactions, autoimmune diseases, allograft rejection, and humoral factors associated with malignancy. It is an acquired condition characterized by progressive destruction and loss of the intra-hepatic bile ducts leading to cholestasis. Prognosis is variable and partially dependent upon the etiology of bile duct injury. Irreversible bile duct loss leads to significant ductopenia, biliary cirrhosis, liver failure, and death. If biliary epithelial regeneration occurs, clinical recovery may occur over a period of months to years. VBDS has been described in a number of cases of patients with Hodgkin's lymphoma (HL) where it is thought to be a paraneoplastic phenomenon. This case describes a 25-year-old man found on liver biopsy to have VBDS. Given poor response to medical treatment, the patient underwent transplant evaluation at that time and was found to have classical stage IIB HL. Early recognition of this underlying cause or association of VBDS, including laboratory screening, and physical exam for lymphadenopathy are paramount to identifying potential underlying VBDS-associated malignancy. Here we review the literature of HL-associated VBDS and report a case of diagnosed HL with biopsy proven VBDS.

Radiative decay of the fermionic state with vanishing angular momentum in the field of a magnetic monopole

NASA Astrophysics Data System (ADS)

Itoh, Katsumi; Kazama, Yoichi

1986-03-01

As one of the possible mechanisms which may reduce the rate for the monopole-catalyzed proton decay, the radiative transition of the fermionic state with vanishing angular momentum ( J) into those with higher J is investigated. The lowest-order formula for the transition rate, which nevertheless takes full account of the interaction with the background monopole field, is derived and numerically evaluated. It is found that the decay rate for a light fermion is unusually large. (e.g. one photon emission rate for a positron, with an incident energy of 300 MeV, is about 30 MeV.) Our results indicate that by itself the one gauge boson emission rate is not expected to affect the catalysis substantially, but that it is large enough to call for further study of multiple emissions and higher-order corrections.

Evaluating Small Sphere Limit of the Wang-Yau Quasi-Local Energy

NASA Astrophysics Data System (ADS)

Chen, Po-Ning; Wang, Mu-Tao; Yau, Shing-Tung

2018-01-01

In this article, we study the small sphere limit of the Wang-Yau quasi-local energy defined in Wang and Yau (Phys Rev Lett 102(2):021101, 2009, Commun Math Phys 288(3):919-942, 2009). Given a point p in a spacetime N, we consider a canonical family of surfaces approaching p along its future null cone and evaluate the limit of the Wang-Yau quasi-local energy. The evaluation relies on solving an "optimal embedding equation" whose solutions represent critical points of the quasi-local energy. For a spacetime with matter fields, the scenario is similar to that of the large sphere limit found in Chen et al. (Commun Math Phys 308(3):845-863, 2011). Namely, there is a natural solution which is a local minimum, and the limit of its quasi-local energy recovers the stress-energy tensor at p. For a vacuum spacetime, the quasi-local energy vanishes to higher order and the solution of the optimal embedding equation is more complicated. Nevertheless, we are able to show that there exists a solution that is a local minimum and that the limit of its quasi-local energy is related to the Bel-Robinson tensor. Together with earlier work (Chen et al. 2011), this completes the consistency verification of the Wang-Yau quasi-local energy with all classical limits.

Isospin effects on the system mass dependence of nuclear stopping around the energy of vanishing flow

NASA Astrophysics Data System (ADS)

Jain, Anupriya; Kumar, Suneel

2014-10-01

We study the effect of isospin degree of freedom on nuclear stopping throughout the mass range 50 and 350 for two sets of isotopic systems with N/Z ≈ 1.5 and 1.8, as well as isobaric systems with N/Z = 1.0 and 1.4. Analysis is carried out at incident energies below, at, and above the energy of vanishing flow (EVF) using the isospin-dependent quantum molecular dynamics model. Our findings reveal that nuclear stopping does not show any particular behavior at the EVF. Moreover, system size effects dominate the isospin effects throughout the range of colliding geometry. The Coulomb effects, however, become important at peripheral geometry. The comparative study of the counterbalancing of Coulomb and mean field by removing the nucleon-nucleon collisions and symmetry potential clearly indicates the dominance of nucleon-nucleon cross-section over the Coulomb repulsions. Moreover, the theoretical results presented in this manuscript for the set of reactions can be experimentally verified.

Acute vanishing bile duct syndrome after therapy with cephalosporin, metronidazole, and clotrimazole: A case report.

PubMed

Zhao, Zonghao; Bao, Lei; Yu, Xiaolan; Zhu, Chuanlong; Xu, Jing; Wang, Yu; Yin, Ming; Li, Yi; Li, Wenting

2017-09-01

Vanishing bile duct syndrome (VBDS) consists of a series of diseases characterized by the loss of >50% bile duct in portal areas. Many factors are associated with VBDS including infections, neoplasms, and drugs. Antibiotic is one of the most frequently reported causes of VBDS. A 29-year-old female was admitted because of liver injury for over 3 months. Tests for viruses that can cause hepatitis and autoantibodies were all negative. She was prescribed with antibiotics approximately a week before liver injury while there was no history of alcohol consumption. Liver biopsy demonstrated a loss of intrahepatic bile duct in most of the portal tracts. This patient was treated with ursodeoxycholic acid, polyene phosphatidylcholine, and bicyclol. Most importantly, the treatments in our hospital were proved by the ethics committee of Department of Infectious Disease, Anhui Provincial Hospital. The symptoms were improved. She is still under treatment. VBDS is rare but can be severe. A liver biopsy offers an important evidence for the diagnosis of VBDS, especially for those with a history of susceptible drugs taking.

The dynamic generalization of the Eshelby inclusion problem and its static limit

PubMed Central

2016-01-01

The dynamic generalization of the celebrated Eshelby inclusion with transformation strain is the (subsonically) self-similarly expanding ellipsoidal inclusion starting from the zero dimension. The solution of the governing system of partial differential equations was obtained recently by Ni & Markenscoff (In press. J. Mech. Phys. Solids (doi:10.1016/j.jmps.2016.02.025)) on the basis of the Radon transformation, while here an alternative method is presented. In the self-similarly expanding motion, the Eshelby property of constant constrained strain is valid in the interior domain of the expanding ellipsoid where the particle velocity vanishes (lacuna). The dynamic Eshelby tensor is obtained in integral form. From it, the static Eshelby tensor is obtained by a limiting procedure, as the axes' expansion velocities tend to zero and time to infinity, while their product is equal to the length of the static axis. This makes the Eshelby problem the limit of its dynamic generalization. PMID:27493574

Similarities and differences between infantile and early childhood onset vanishing white matter disease.

PubMed

Zhou, Ling; Zhang, Haihua; Chen, Na; Zhang, Zhongbin; Liu, Ming; Dai, Lifang; Wang, Jingmin; Jiang, Yuwu; Wu, Ye

2018-06-01

Vanishing white matter disease (VWM) is one of the most prevalent inherited leukoencephalopathies in childhood. Infantile VWM is more severe but less understood than the classic early childhood type. We performed a follow-up study on 14 infantile and 26 childhood patients to delineate the natural history and neuroimaging features of VWM. Infantile and childhood patients shared similarities in the incidence of epileptic seizure (35.7 vs. 38.5%) and episodic aggravation (92.9 vs. 84.6%). Developmental delay before disease onset was more common in infantile patients. Motor disability was earlier and more severe in infantile VWM. In survivors with disease durations of 1-3 years, the Gross Motor Function Classification System (GMFCS) was classified as IV-V in 66.7% of infantile and only 29.4% of childhood patients. Kaplan-Meier survival curve analysis indicated that the 5-year survival rates were 21.6 and 91.3% in infantile and childhood VWM, respectively. In terms of MRI, infantile patients showed more extensive involvement and earlier rarefaction, with more common involvement of subcortical white matter, internal capsule, brain stem and dentate nuclei of the cerebellum. Restricted diffusion was more diffuse or extensive in infantile patients. In addition, four novel mutations were identified. In conclusion, we identified some similarities and differences in the natural history and neuroimaging features between infantile and early childhood VWM.

Vanishing bile duct syndrome in Hodgkin’s lymphoma: A case report and literature review

PubMed Central

Bakhit, Mena; McCarty, Thomas R; Park, Sunhee; Njei, Basile; Cho, Margaret; Karagozian, Raffi; Liapakis, AnnMarie

2017-01-01

Vanishing bile duct syndrome (VBDS) has been described in different pathologic conditions including infection, ischemia, adverse drug reactions, autoimmune diseases, allograft rejection, and humoral factors associated with malignancy. It is an acquired condition characterized by progressive destruction and loss of the intra-hepatic bile ducts leading to cholestasis. Prognosis is variable and partially dependent upon the etiology of bile duct injury. Irreversible bile duct loss leads to significant ductopenia, biliary cirrhosis, liver failure, and death. If biliary epithelial regeneration occurs, clinical recovery may occur over a period of months to years. VBDS has been described in a number of cases of patients with Hodgkin’s lymphoma (HL) where it is thought to be a paraneoplastic phenomenon. This case describes a 25-year-old man found on liver biopsy to have VBDS. Given poor response to medical treatment, the patient underwent transplant evaluation at that time and was found to have classical stage IIB HL. Early recognition of this underlying cause or association of VBDS, including laboratory screening, and physical exam for lymphadenopathy are paramount to identifying potential underlying VBDS-associated malignancy. Here we review the literature of HL-associated VBDS and report a case of diagnosed HL with biopsy proven VBDS. PMID:28127210

Bore holes and the vanishing of guinea worm disease in Ghana's upper region.

PubMed

Hunter, J M

1997-07-01

Ghana's Upper Region provides an excellent example of the beneficial effects of improved water security provided by hand-pump tube wells. Following a Ghana-Canada bilateral development project that installed some 2500 pumps, protection rates against guinea worm disease may be estimated as 88% in the west, and 96% in the east. Survey comparisons between ca 1960 and 1990 show that dracunculiasis declined in 32 of a total of 38 areas. The shadow of guinea worm has been lifted from the land and, in many areas, a true "vanishing" has occurred. The few areas of disease increase are characterized by the lowest population densities, pioneer settlement for cotton farming, and an absence of bore holes. Vagaries of development have inadvertently produced disease transformations or "metamorphoses" from dracunculiasis to elephantiasis (lymphatic filariasis) in one area, and to red water disease (schistosomiasis hematobium) in other areas. Correlative associations between pump densities and guinea worm disease are weakened by the large size of areas for which disease is reported in 1990. One preliminary finding is that geographical distance to the pump is a stronger influence than demographic pressure on pumps, regarding dracunculiasis. Diminishing returns on higher pump densities in many areas support the idea of making fuller, safer use of supplementary non-pump water. Despite crises of fee payment and pump maintenance, the rural bore hole project has struck a mortal blow against guinea worm, and permanently raised the quality of life in the Upper Region.

[Association between homozygous c.318A>GT mutation in exon 2 of the EIF2B5 gene and the infantile form of vanishing white matter leukoencephalopathy].

PubMed

Esmer, Carmen; Blanco Hernández, Gabriela; Saavedra Alanís, Víctor; Reyes Vaca, Jorge Guillermo; Bravo Oro, Antonio

Vanishing white matter disease is one of the most frequent leukodystrophies in childhood with an autosomal recessive inheritance. A mutation in one of the genes encoding the five subunits of the eukaryotic initiation factor 2 (EIF2B5) is present in 90% of the cases. The diagnosis can be accomplished by the clinical and neuroradiological findings and molecular tests. We describe a thirteen-month-old male with previous normal neurodevelopment, who was hospitalized for vomiting, hyperthermia and irritability. On examination, cephalic perimeter and cranial pairs were normal. Hypotonia, increased muscle stretching reflexes, generalized white matter hypodensity on cranial tomography were found. Fifteen days after discharge, he suffered minor head trauma presenting drowsiness and focal seizures. Magnetic resonance showed generalized hypointensity of white matter. Vanishing white matter disease was suspected, and confirmed by sequencing of the EIF2B5 gene, revealing a homozygous c.318A> T mutation in exon 2. Subsequently, visual acuity was lost and cognitive and motor deterioration was evident. The patient died at six years of age due to severe pneumonia. This case contributes to the knowledge of the mutational spectrum present in Mexican patients and allows to extend the phenotype associated to this mutation. Copyright © 2017. Publicado por Masson Doyma México S.A.

Fear of Circumcision in Boys Considerably Vanishes within Ten Days of Procedure.

PubMed

Sancar, Serpil; Demirci, Hakan; Guzelsoy, Muhammet; Coban, Soner; Askin, Rustem; Uzun, Mehmet Erdem; Turkoglu, Ali Riza

2016-03-05

To compare fear of circumcision, before, immediately after, and ten days after the operation. This was a case-control study in which participants in the operation group consisted of children admitted for circumcision at the outpatient clinics of a hospital. The Children's Fear Scale and the Venham Picture Test were administered by face-to-face interviews. The sample consisted of 100 boys who were circumcised and 99 who have not been circumcised yet. Children's Fear Scale scores measured before (P = .000) and immediately after the operation (P = .000) were significantly different from scores obtained on the 10th day after the operation. Total fear scores of the Venham Picture Test of boys whose families were in the higher economic level were higher than those of boys from low-income families (P < .05). The primary reason for admission for circumcision was religious, and the reason for the remaining boys was a combination of religious and hygienic factors. The boys who came to have circumcision solely because of religious reasons were found to be less fearful compared with the boys who were brought to surgery for both religious and medical reasons (P < .05). The lowest fear scores were obtained for boys who were six years of age or older. Boys who knew what the circumcision meant were less afraid of circumcision compared with those who were unaware of the procedure. Fear from circumcision does not persist; it considerably vanishes within ten days. It seems reasonable to recommend circumcision for boys six years of age or older. Pre-operative education may help boys to overcome fear originated from circumcision.

Limitation to Communication of Fermionic System in Accelerated Frame

NASA Astrophysics Data System (ADS)

Chang, Jinho; Kwon, Younghun

2015-03-01

In this article, we investigate communication between an inertial observer and an accelerated observer, sharing fermionic system, when they use classical and quantum communication using single rail or dual rail encoding. The purpose of this work is to understand the limit to the communication between an inertial observer and an accelerated observer, with single rail or dual rail encoding of fermionic system. We observe that at the infinite acceleration, the coherent information of single(or double) rail quantum channel vanishes, but those of classical ones may have finite values. In addition, we see that even when considering a method beyond the single-mode approximation, for the communication between Alice and Bob, the dual rail entangled state seems to provide better information transfer than the single rail entangled state, when we take a fixed choice of the Unruh mode. Moreover, we find that the single-mode approximation may not be sufficient to analyze communication of fermionic system in an accelerated frame.

High Risk Behaviors in Marine Mammals: Linking Behavioral Responses to Anthropogenic Disturbance to Biological Consequences

DTIC Science & Technology

2014-09-30

98) Prescribed by ANSI Std Z39-18 2 injury via cardiovascular performance during submergence. Neuro -protection through globin deposition and...relationships for stroking costs, aerobic dive limits, types of neuro -protection (globin deposition, capillarity), and cardiac risk factors that will be mapped...Greenland. A custom built ECG recorder with 3- axis accelerometer recorder and pressure transducer was combined with retrieval transmitters (Argos

The limitation and applicability of Musher-Sturman equation to two dimensional lower hybrid wave collapse

NASA Technical Reports Server (NTRS)

Tam, Sunny W. Y.; Chang, Tom

1995-01-01

The existence of localized regions of intense lower hybrid waves in the auroral ionosphere recently observed by rocket and satellite experiments can be understood by the study of a non-linear two-timescale coupling process. In this Letter, we demonstrate that the leading non-linear term in the standard Musher-Sturman equation vanishes identically in strict two-dimensions (normal to the magnetic field). Instead, the new two-dimensional equation is characterized by a much weaker non-linear term which arises from the ponderomotive force perpendicular to the magnetic field, particularly that due to the ions. The old and new equations are compared by means of time-evolution calculations of wave fields. The results exhibit a remarkable difference in the evolution of the waves as governed by the two equations. Such dissimilar outcomes motivate our investigation of the limitation of Musher-Sturman equation in quasi-two-dimensions. Only within all these limits can Musher-Sturman equation adequately describe the collapse of lower hybrid waves.

Capillarity creates single-crystal calcite nanowires from amorphous calcium carbonate.

PubMed

Kim, Yi-Yeoun; Hetherington, Nicola B J; Noel, Elizabeth H; Kröger, Roland; Charnock, John M; Christenson, Hugo K; Meldrum, Fiona C

2011-12-23

Single-crystal calcite nanowires are formed by crystallization of morphologically equivalent amorphous calcium carbonate (ACC) particles within the pores of track etch membranes. The polyaspartic acid stabilized ACC is drawn into the membrane pores by capillary action, and the single-crystal nature of the nanowires is attributed to the limited contact of the intramembrane ACC particle with the bulk solution. The reaction environment then supports transformation to a single-crystal product. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals.

PubMed

Pörtner, H O

2001-04-01

Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed.

Vanishing Viscosity Approach to the Compressible Euler Equations for Transonic Nozzle and Spherically Symmetric Flows

NASA Astrophysics Data System (ADS)

Chen, Gui-Qiang G.; Schrecker, Matthew R. I.

2018-04-01

We are concerned with globally defined entropy solutions to the Euler equations for compressible fluid flows in transonic nozzles with general cross-sectional areas. Such nozzles include the de Laval nozzles and other more general nozzles whose cross-sectional area functions are allowed at the nozzle ends to be either zero (closed ends) or infinity (unbounded ends). To achieve this, in this paper, we develop a vanishing viscosity method to construct globally defined approximate solutions and then establish essential uniform estimates in weighted L p norms for the whole range of physical adiabatic exponents γ\\in (1, ∞) , so that the viscosity approximate solutions satisfy the general L p compensated compactness framework. The viscosity method is designed to incorporate artificial viscosity terms with the natural Dirichlet boundary conditions to ensure the uniform estimates. Then such estimates lead to both the convergence of the approximate solutions and the existence theory of globally defined finite-energy entropy solutions to the Euler equations for transonic flows that may have different end-states in the class of nozzles with general cross-sectional areas for all γ\\in (1, ∞) . The approach and techniques developed here apply to other problems with similar difficulties. In particular, we successfully apply them to construct globally defined spherically symmetric entropy solutions to the Euler equations for all γ\\in (1, ∞).

Vacuum stability in the U(1)χ extended model with vanishing scalar potential at the Planck scale

NASA Astrophysics Data System (ADS)

Haba, Naoyuki; Yamaguchi, Yuya

2015-09-01

We investigate the vacuum stability in a scale invariant local {U}(1)_χ model with vanishing scalar potential at the Planck scale. We find that it is impossible to realize the Higgs mass of 125 GeV while keeping the Higgs quartic coupling λ _H positive in all energy scales, that is, the same as the standard model. Once one allows λ _H<0, the lower bounds of the Z' boson mass ares obtained through the positive definiteness of the scalar mass squared eigenvalues, while the bounds are smaller than the LHC bounds. On the other hand, the upper bounds strongly depend on the number of relevant Majorana Yukawa couplings of the right-handed neutrinos N_ν . Considering decoupling effects of the Z' boson and the right-handed neutrinos, the condition of the singlet scalar quartic coupling λ _φ >0 gives the upper bound in the N_ν =1 case, while it does not constrain the N_ν =2 and 3 cases. In particular, we find that the Z' boson mass is tightly restricted for the N_ν =1 case as M_{Z'} &lsim 3.7 TeV.

Capillarity-Driven Bubble Separations

NASA Astrophysics Data System (ADS)

Wollman, Andrew; Weislogel, Mark; Dreyer, Michael

2013-11-01

Techniques for phase separation in the absence of gravity continue to be sought after 5 decades of space flight. This work focuses on the fundamental problem of gas bubble separation in bubbly flows through open wedge-shaped channel in a microgravity environment. The bubbles appear to rise in the channel and coalesce with the free surface. Forces acting on the bubble are the combined effects of surface tension, wetting conditions, and geometry; not buoyancy. A single dimensionless group is identified that characterizes the bubble behavior and supportive experiments are conducted in a terrestrial laboratory, in a 2.1 second drop tower, and aboard the International Space Station as part of the Capillary Channel Flow (CCF) experiments. The data is organized into regime maps that provide insight on passive phase separations for applications ranging from liquid management aboard spacecraft to lab-on-chip technologies. NASA NNX09AP66A, NASA Oregon Space Grant NNX10AK68H, NASA NNX12AO47A, DLR 50WM0535/0845/1145

Effect of chronic ethanol ingestion and exercise training on skeletal muscle in rat.

PubMed

Vila, L; Ferrando, A; Voces, J; Cabral de Oliveira, C; Prieto, J G; Alvarez, A I

2001-09-01

The aim of this study was to investigate the interactive effects of exercise training and chronic ethanol consumption on metabolism, capillarity, and myofibrillar composition in rat limb muscles. Male Wistar rats were treated in separate groups as follows: non exercised-control; ethanol (15%) in animals' drinking water for 12 weeks; exercise training in treadmill and ethanol administration plus exercise for 12 weeks. Ethanol administration decreased capillarity and increased piruvate kinase and lactate dehydrogenase activities in white gastrocnemius; in plantaris muscle, ethanol increased citrate synthase activity and decreased cross-sectional area of type I, IIa, and IIb fibres. Exercise increased capillarity in all four limb muscles and decreased type I fibre area in plantaris. The decreased capillarity effect induced by ethanol in some muscles, was ameliorated when alcohol was combined with exercise. While alcoholic myopathy affects predominantly type IIb fibres, ethanol administration and aerobic exercise in some cases can affect type I and type IIa fibre areas. The exercise can decrease some harmful effects produced by ethanol in the muscle, including the decrease in the fibre area and capillary density.

The Phantom Vanish Magic Trick: Investigating the Disappearance of a Non-existent Object in a Dynamic Scene

PubMed Central

Tompkins, Matthew L.; Woods, Andy T.; Aimola Davies, Anne M.

2016-01-01

Drawing inspiration from sleight-of-hand magic tricks, we developed an experimental paradigm to investigate whether magicians’ misdirection techniques could be used to induce the misperception of “phantom” objects. While previous experiments investigating sleight-of-hand magic tricks have focused on creating false assumptions about the movement of an object in a scene, our experiment investigated creating false assumptions about the presence of an object in a scene. Participants watched a sequence of silent videos depicting a magician performing with a single object. Following each video, participants were asked to write a description of the events in the video. In the final video, participants watched the Phantom Vanish Magic Trick, a novel magic trick developed for this experiment, in which the magician pantomimed the actions of presenting an object and then making it magically disappear. No object was presented during the final video. The silent videos precluded the use of false verbal suggestions, and participants were not asked leading questions about the objects. Nevertheless, 32% of participants reported having visual impressions of non-existent objects. These findings support an inferential model of perception, wherein top-down expectations can be manipulated by the magician to generate vivid illusory experiences, even in the absence of corresponding bottom-up information. PMID:27493635

Limits on amplification by Aharonov-Albert-Vaidman weak measurement

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

Koike, Tatsuhiko; Tanaka, Saki

2011-12-15

We analyze the amplification by the Aharonov-Albert-Vaidman weak quantum measurement on a Sagnac interferometer [Dixon et al., Phys. Rev. Lett. 102, 173601 (2009)] up to all orders of the coupling strength between the measured system and the measuring device. The amplifier transforms a small tilt of a mirror into a large transverse displacement of the laser beam. The conventional analysis has shown that the measured value is proportional to the weak value, so that the amplification can be made arbitrarily large in the cost of decreasing output laser intensity. It is shown that the measured displacement and the amplification factormore » are in fact not proportional to the weak value and rather vanish in the limit of infinitesimal output intensity. We derive the optimal overlap of the pre- and postselected states with which the amplification become maximum. We also show that the nonlinear effects begin to arise in the performed experiments so that any improvements in the experiment, typically with an amplification greater than 100, should require the nonlinear theory in translating the observed value to the original displacement.« less

Magnetodynamic stability of a fluid cylinder under the Lundquist force-free magnetic field

NASA Astrophysics Data System (ADS)

Radwan, Ahmed E.; Halawa, Mohamed A.

1990-04-01

The magnetodynamic (in)stability of a conducting fluid cylinder subject to the capillarity and electromagnetic forces has been developed. The cylinder is pervaded by a uniform magnetic field but embedded in the Lundquist force-free varying field that allows for flowing a current surrounding the fluid. A general eigenvalue relation is derived based on a study of the equilibrium and perturbed states. The stability criterion is discussed analytically in general terms. The surface tension is destabilizing for small axisymmetric mode and stable for all others. The principle of the exchange of stability is allowed for the present problem due to the non-uniform behavior of the force-free field. Each of the axial and transverse force-free fields separately exerts a stabilizing influence in the most dangerous mode but the combined contribution of them is strongly destabilizing. Whether the model is acted upon the electromagnetic force (with the Lundquist field) the stability restrictions or/and the capillarity force are identified. Several reported works can be recovered as limiting cases with appropriate simplifications.

Determination of glucosinolates in rapeseed and Thlaspi caerulescens plants by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

PubMed

Tolrà, R P; Alonso, R; Poschenrieder, C; Barceló, D; Barceló, J

2000-08-11

Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry was used to identify glucosinolates in plant extracts. Optimization of the analytical conditions and the determination of the method detection limit was performed using commercial 2-propenylglucosinolate (sinigrin). Optimal values for the following parameters were determined: nebulization pressure, gas temperature, flux of drying gas, capillar voltage, corona current and fragmentor conditions. The method detection limit for sinigrin was 2.85 ng. For validation of the method the glucosinolates in reference material (rapeseed) from the Community Bureau of Reference Materials (BCR) were analyzed. The method was applied for the determination of glucosinolates in Thlaspi caerulescens plants.

Limit of Kerr-de Sitter spacetime with infinite angular-momentum parameter a

NASA Astrophysics Data System (ADS)

Mars, Marc; Paetz, Tim-Torben; Senovilla, José M. M.

2018-01-01

We consider the limit a →∞ of the Kerr-de Sitter spacetime. The spacetime is a Petrov type-D solution of the vacuum Einstein field equations with a positive cosmological constant Λ , vanishing Mars-Simon tensor and conformally flat ℐ . It possesses an Abelian 2-dimensional group of symmetries whose orbits are spacelike or timelike in different regions, and it includes, as a particular case, de Sitter spacetime. The global structure of the solution is analyzed in detail, with particular attention to its Killing horizons: they are foliated by noncompact marginally trapped surfaces of finite area, and one of them "touches" the curvature singularity, which resembles a null 2-dimensional surface. Outside the region between these horizons there exist trapped surfaces that again are noncompact. The solution contains, apart from Λ , a unique free parameter which can be related to the angular momentum of the nonsingular horizon in a precise way. A maximal extension of the (axis of the) spacetime is explicitly built. We also analyze the structure of ℐ , whose topology is R3.

Vanishing Croplands.

ERIC Educational Resources Information Center

Brown, Lester R.

1978-01-01

Natural soil fertility is now declining on an estimated one-fifth of the world's croplands. Direct evidence of the mounting pressures on the global cropland base is seen in accelerating soil erosion, the spread of deserts, and the loss of cropland to nonfarm uses. (Author/BB)

Towards Cryogenic Liquid-Vapor Energy Storage Units for space applications

NASA Astrophysics Data System (ADS)

Afonso, Josiana Prado

With the development of mechanical coolers and very sensitive cryogenic sensors, it could be interesting to use Energy Storage Units (ESU) and turn off the cryocooler to operate in a free micro vibration environment. An ESU would also avoid cryogenic systems oversized to attenuate temperature fluctuations due to thermal load variations which is useful particularly for space applications. In both cases, the temperature drift must remain limited to keep good detector performances. In this thesis, ESUs based on the high latent heat associated to liquid-vapor phase change to store energy have been studied. To limit temperature drifts while keeping small size cell at low temperature, a potential solution consists in splitting the ESU in two volumes: a low temperature cell coupled to a cryocooler cold finger through a thermal heat switch and an expansion volume at room temperature to reduce the temperature increase occurring during liquid evaporation. To obtain a vanishing temperature drift, a new improvement has been tested using two-phase nitrogen: a controlled valve was inserted between the two volumes in order to control the cold cell pressure. In addition, a porous material was used inside the cell to turn the ESU gravity independent and suitable for space applications. In this case, experiments reveal not fully understood results concerning both energy storage and liquid-wall temperature difference. To capture the thermal influence of the porous media, a dedicated cell with poorly conductive lateral wall was built and operated with two-phase helium. After its characterization outside the saturation conditions (conduction, convection), experiments were performed, with and without porous media, heating at the top or the bottom of the cell with various heat fluxes and for different saturation temperatures. In parallel, a model describing the thermal response for a cell containing liquid and vapor with a porous medium heated at the top ("against gravity") was developed

Enhanced transport of materials into enamel nanopores via electrokinetic flow.

PubMed

Gan, H Y; Sousa, F B; Carlo, H L; Maciel, P P; Macena, M S; Han, J

2015-04-01

The ability to infiltrate various molecules and resins into dental enamel is highly desirable in dentistry, yet transporting materials into dental enamel is limited by the nanometric scale of their pores. Materials that cannot be infiltrated into enamel by diffusion/capillarity are often considered molecules with sizes above a critical threshold, which are often considered to be larger than the pores of enamel. We challenge this notion by reporting the use of electrokinetic flow to transport solutions with molecules with sizes above a critical threshold-namely, an aqueous solution with a high refractive index (Thoulet's solution) and a curable fluid resin infiltrant (without acid etching)-deep into the normal enamel layer. Volume infiltration by Thoulet's solution is increased by 5- to 6-fold, and resin infiltration depths as large as 600 to 2,000 µm were achieved, in contrast to ~10 µm resulting from diffusion/capillarity. Incubation with demineralization solution for 192 h resulted in significant demineralization at noninfiltrated histologic points but not at resin infiltrated. These results open new avenues for the transport of materials in dental enamel. © International & American Associations for Dental Research 2015.

Humidity-enhanced wet adhesion on insect-inspired fibrillar adhesive pads

PubMed Central

Xue, Longjian; Kovalev, Alexander; Eichler-Volf, Anna; Steinhart, Martin; Gorb, Stanislav N.

2015-01-01

Many insect species reversibly adhere to surfaces by combining contact splitting (contact formation via fibrillar contact elements) and wet adhesion (supply of liquid secretion via pores in the insects’ feet). Here, we fabricate insect-inspired fibrillar pads for wet adhesion containing continuous pore systems through which liquid is supplied to the contact interfaces. Synergistic interaction of capillarity and humidity-induced pad softening increases the pull-off force and the work of adhesion by two orders of magnitude. This increase and the independence of pull-off force on the applied load are caused by the capillarity-supported formation of solid–solid contact between pad and the surface. Solid–solid contact dominates adhesion at high humidity and capillarity at low humidity. At low humidity, the work of adhesion strongly depends on the amount of liquid deposited on the surface and, therefore, on contact duration. These results may pave the way for the design of insect-inspired adhesive pads. PMID:25791574

No need for a social cue! A masked magician can also trick the audience in the vanishing ball illusion.

PubMed

Thomas, Cyril; Didierjean, André

2016-01-01

In the vanishing ball illusion (VBI), a magician throws a ball up in the air twice, after which he pretends to toss it up again, when in fact it remains secretly concealed in his hand. Observers perceive an imaginary ball disappearing into the air. According to Kuhn and Land (2006), the VBI during the fake throw is mediated by the magician's gaze and/or head direction (also called "social cues") as he looks toward the imaginary ball. The aim of this article is to test an alternative interpretation. According to our hypothesis, the magician's social cues are not essential to the VBI. We compared the numbers of participants experiencing the VBI when the magician's social cues were directed toward the illusory ball and when the magician's social cues were either hidden behind a black mask (Exp. 1) or stationary (Exp. 2). The results showed that the number of observers experiencing the VBI was high (almost two-thirds of the participants), regardless of whether the magician's social cueing was directed toward the illusion, hidden behind a mask, or stationary. In a third experiment (Exp. 3), we replicated Kuhn and Land's initial results and attempted to further explain their "anti-illusion" social-cue effect. This study confirms that social cueing is not required in the VBI: Its presence did not increase the number of participants experiencing the illusion.

Infiltration behaviour of liquids over fibres or woven

NASA Astrophysics Data System (ADS)

Martinez, M. A.; Abenojar, J.; Enciso, B.; Lopez de Armentia, S.

2018-05-01

The high porosity of fabrics and fibres have hindered the study of the interaction between fluids and those kind of materials. In order to understand penetration mechanisms of polymeric matrices or woven sealing, some properties such as wettability or capillarity must be analysed. The fluid speed through some woven could be compared with metallic meshes in those is easy to determine pores size. In this work it is tried to solve these problems from a theoretical point of view by using hydrostatic laws and capillarity effect.

Blunted angiogenesis and hypertrophy are associated with increased fatigue resistance and unchanged aerobic capacity in old overloaded mouse muscle.

PubMed

Ballak, Sam B; Busé-Pot, Tinelies; Harding, Peter J; Yap, Moi H; Deldicque, Louise; de Haan, Arnold; Jaspers, Richard T; Degens, Hans

2016-04-01

We hypothesize that the attenuated hypertrophic response in old mouse muscle is (1) partly due to a reduced capillarization and angiogenesis, which is (2) accompanied by a reduced oxidative capacity and fatigue resistance in old control and overloaded muscles, that (3) can be rescued by the antioxidant resveratrol. To investigate this, the hypertrophic response, capillarization, oxidative capacity, and fatigue resistance of m. plantaris were compared in 9- and 25-month-old non-treated and 25-month-old resveratrol-treated mice. Overload increased the local capillary-to-fiber ratio less in old (15 %) than in adult (59 %) muscle (P < 0.05). Although muscles of old mice had a higher succinate dehydrogenase (SDH) activity (P < 0.05) and a slower fiber type profile (P < 0.05), the isometric fatigue resistance was similar in 9- and 25-month-old mice. In both age groups, the fatigue resistance was increased to the same extent after overload (P < 0.01), without a significant change in SDH activity, but an increased capillary density (P < 0.05). Attenuated angiogenesis during overload may contribute to the attenuated hypertrophic response in old age. Neither was rescued by resveratrol supplementation. Changes in fatigue resistance with overload and aging were dissociated from changes in SDH activity, but paralleled those in capillarization. This suggests that capillarization plays a more important role in fatigue resistance than oxidative capacity.

Eigensolution analysis of spectral/hp continuous Galerkin approximations to advection-diffusion problems: Insights into spectral vanishing viscosity

NASA Astrophysics Data System (ADS)

Moura, R. C.; Sherwin, S. J.; Peiró, J.

2016-02-01

This study addresses linear dispersion-diffusion analysis for the spectral/hp continuous Galerkin (CG) formulation in one dimension. First, numerical dispersion and diffusion curves are obtained for the advection-diffusion problem and the role of multiple eigencurves peculiar to spectral/hp methods is discussed. From the eigencurves' behaviour, we observe that CG might feature potentially undesirable non-smooth dispersion/diffusion characteristics for under-resolved simulations of problems strongly dominated by either convection or diffusion. Subsequently, the linear advection equation augmented with spectral vanishing viscosity (SVV) is analysed. Dispersion and diffusion characteristics of CG with SVV-based stabilization are verified to display similar non-smooth features in flow regions where convection is much stronger than dissipation or vice-versa, owing to a dependency of the standard SVV operator on a local Péclet number. First a modification is proposed to the traditional SVV scaling that enforces a globally constant Péclet number so as to avoid the previous issues. In addition, a new SVV kernel function is suggested and shown to provide a more regular behaviour for the eigencurves along with a consistent increase in resolution power for higher-order discretizations, as measured by the extent of the wavenumber range where numerical errors are negligible. The dissipation characteristics of CG with the SVV modifications suggested are then verified to be broadly equivalent to those obtained through upwinding in the discontinuous Galerkin (DG) scheme. Nevertheless, for the kernel function proposed, the full upwind DG scheme is found to have a slightly higher resolution power for the same dissipation levels. These results show that improved CG-SVV characteristics can be pursued via different kernel functions with the aid of optimization algorithms.

Conserved charge fluctuations at vanishing and non-vanishing chemical potential

NASA Astrophysics Data System (ADS)

Karsch, Frithjof

2017-11-01

Up to 6th order cumulants of fluctuations of net baryon-number, net electric charge and net strangeness as well as correlations among these conserved charge fluctuations are now being calculated in lattice QCD. These cumulants provide a wealth of information on the properties of strong-interaction matter in the transition region from the low temperature hadronic phase to the quark-gluon plasma phase. They can be used to quantify deviations from hadron resonance gas (HRG) model calculations which frequently are used to determine thermal conditions realized in heavy ion collision experiments. Already some second order cumulants like the correlations between net baryon-number and net strangeness or net electric charge differ significantly at temperatures above 155 MeV in QCD and HRG model calculations. We show that these differences increase at non-zero baryon chemical potential constraining the applicability range of HRG model calculations to even smaller values of the temperature.

Can quantum transition state theory be defined as an exact t = 0+ limit?

NASA Astrophysics Data System (ADS)

Jang, Seogjoo; Voth, Gregory A.

2016-02-01

that the t → 0+ limit of the new rate expression vanishes in the exact quantum limit.

Exploiting metasurface anisotropy for achieving near-perfect low-profile cloaks beyond the quasi-static limit

NASA Astrophysics Data System (ADS)

Hao Jiang, Zhi; Werner, Douglas H.

2013-12-01

In this paper, we report an approach for achieving near-perfect low-profile electromagnetic cloaking beyond the quasi-static limit. In contrast to previous works on metasurface cloaks where only the Leontovich surface impedance boundary condition has been considered, we employ a second-order surface impedance boundary condition to account for the radial response of the proposed anisotropic metasurfaces. This radial surface polarizability tensor parameter can be tailored to eliminate the higher order scattering modes. It is shown from analytical expressions that for a moderate-sized perfect electric conducting or dielectric cylinder (∼0.4λ0 in width), near-perfect scattering reduction, i.e. >98%, can be achieved by a single anisotropic metasurface with non-vanishing radial response, which is far superior to the conventional scalar impedance surface. A practical design of the metasurface is also presented and further validated by full-wave simulations. The physical mechanism of the metasurface cloaks is investigated in detail, revealing that the radiation cancellation of the induced surface currents is responsible for the scattering reduction. Importantly, it is shown that in addition to a ‘low-visibility coating’, the metasurface also functions to provide induced current enhancement which would be beneficial for the operation of a ‘cloaked sensor’. These findings will broaden the usage of metasurfaces to applications ranging from scattering reduction to noninvasive probing for objects beyond the quasi-static limit.

Visible near-diffraction-limited lucky imaging with full-sky laser-assisted adaptive optics

NASA Astrophysics Data System (ADS)

Basden, A. G.

2014-08-01

Both lucky imaging techniques and adaptive optics require natural guide stars, limiting sky-coverage, even when laser guide stars are used. Lucky imaging techniques become less successful on larger telescopes unless adaptive optics is used, as the fraction of images obtained with well-behaved turbulence across the whole telescope pupil becomes vanishingly small. Here, we introduce a technique combining lucky imaging techniques with tomographic laser guide star adaptive optics systems on large telescopes. This technique does not require any natural guide star for the adaptive optics, and hence offers full sky-coverage adaptive optics correction. In addition, we introduce a new method for lucky image selection based on residual wavefront phase measurements from the adaptive optics wavefront sensors. We perform Monte Carlo modelling of this technique, and demonstrate I-band Strehl ratios of up to 35 per cent in 0.7 arcsec mean seeing conditions with 0.5 m deformable mirror pitch and full adaptive optics sky-coverage. We show that this technique is suitable for use with lucky imaging reference stars as faint as magnitude 18, and fainter if more advanced image selection and centring techniques are used.

Limited Effects of Set Shifting Training in Healthy Older Adults

PubMed Central

Grönholm-Nyman, Petra; Soveri, Anna; Rinne, Juha O.; Ek, Emilia; Nyholm, Alexandra; Stigsdotter Neely, Anna; Laine, Matti

2017-01-01

Our ability to flexibly shift between tasks or task sets declines in older age. As this decline may have adverse effects on everyday life of elderly people, it is of interest to study whether set shifting ability can be trained, and if training effects generalize to other cognitive tasks. Here, we report a randomized controlled trial where healthy older adults trained set shifting with three different set shifting tasks. The training group (n = 17) performed adaptive set shifting training for 5 weeks with three training sessions a week (45 min/session), while the active control group (n = 16) played three different computer games for the same period. Both groups underwent extensive pre- and post-testing and a 1-year follow-up. Compared to the controls, the training group showed significant improvements on the trained tasks. Evidence for near transfer in the training group was very limited, as it was seen only on overall accuracy on an untrained computerized set shifting task. No far transfer to other cognitive functions was observed. One year later, the training group was still better on the trained tasks but the single near transfer effect had vanished. The results suggest that computerized set shifting training in the elderly shows long-lasting effects on the trained tasks but very little benefit in terms of generalization. PMID:28386226

Evaluation of a Heuristic Model for Tropical Cyclone Resilience

DTIC Science & Technology

2015-01-26

in which the effective static stability vanishes in rising and sinking regions, the 13 heuristic model yields a poor approximation to the simulated...tilt configuration. However, in the moist-neutral 12 limit, in which the effective static stability vanishes in rising and sinking regions, the 13...larger, leading to more effective 13 damping of the tilt mode (e.g., Schecter and Montgomery 2007; see their Figs. 10 and 11 14 and accompanying

Elasto-capillarity in insect fibrillar adhesion.

PubMed

Gernay, Sophie; Federle, Walter; Lambert, Pierre; Gilet, Tristan

2016-08-01

The manipulation of microscopic objects is challenging because of high adhesion forces, which render macroscopic gripping strategies unsuitable. Adhesive footpads of climbing insects could reveal principles relevant for micro-grippers, as they are able to attach and detach rapidly during locomotion. However, the underlying mechanisms are still not fully understood. In this work, we characterize the geometry and contact formation of the adhesive setae of dock beetles (Gastrophysa viridula) by interference reflection microscopy. We compare our experimental results to the model of an elastic beam loaded with capillary forces. Fitting the model to experimental data yielded not only estimates for seta adhesion and compliance in agreement with previous direct measurements, but also previously unknown parameters such as the volume of the fluid meniscus and the bending stiffness of the tip. In addition to confirming the primary role of surface tension for insect adhesion, our investigation reveals marked differences in geometry and compliance between the three main kinds of seta tips in leaf beetles. © 2016 The Author(s).

Infantile onset Vanishing White Matter disease associated with a novel EIF2B5 variant, remarkably long life span, severe epilepsy, and hypopituitarism.

PubMed

Woody, April L; Hsieh, David T; McIver, Harkirtin K; Thomas, Linda P; Rohena, Luis

2015-04-01

Vanishing White Matter disease (VWM) is an inherited progressive leukoencephalopathy caused by mutations in the genes EIF2B1-5, which encode for the 5 subunits of the eukaryotic initiation factor 2B (eIF2B), a regulator of protein synthesis. VWM typically presents with acute neurological decline following febrile infections or minor head trauma, and subsequent progressive neurological and cognitive regression. There is a varied clinical spectrum of VWM, with earlier onset associated with more severe phenotypes. Brain magnetic resonance imaging is usually diagnostic with diffusely abnormal white matter, progressing over time to cystic degeneration. We are reporting on a patient with infantile onset VWM associated with three heterozygous missense variants in EIF2B5, including a novel missense variant on exon 6 of EIF2B5 (D262N), as well as an interstitial duplication at 7q21.12. In addition, our case is unusual because of a severe epilepsy course, a novel clinical finding of hypopituitarism manifested by hypothyroidism and adrenal insufficiency, and a prolonged life span with current age of survival of 4 years and 11 months. © 2015 Wiley Periodicals, Inc.

Numerical methods for systems of conservation laws of mixed type using flux splitting

NASA Technical Reports Server (NTRS)

Shu, Chi-Wang

1990-01-01

The essentially non-oscillatory (ENO) finite difference scheme is applied to systems of conservation laws of mixed hyperbolic-elliptic type. A flux splitting, with the corresponding Jacobi matrices having real and positive/negative eigenvalues, is used. The hyperbolic ENO operator is applied separately. The scheme is numerically tested on the van der Waals equation in fluid dynamics. Convergence was observed with good resolution to weak solutions for various Riemann problems, which are then numerically checked to be admissible as the viscosity-capillarity limits. The interesting phenomena of the shrinking of elliptic regions if they are present in the initial conditions were also observed.

Effect of chamber characteristics, loading and analysis time on motility and kinetic variables analysed with the CASA-mot system in goat sperm.

PubMed

Del Gallego, R; Sadeghi, S; Blasco, E; Soler, C; Yániz, J L; Silvestre, M A

2017-02-01

Several factors unrelated to the semen samples could be influencing in the sperm motility analysis. The aim of the present research was to study the effect of four chambers with different characteristics, namely; slide-coverslip, Spermtrack, ISAS D4C10, and ISAS D4C20 on the sperm motility. The filling procedure (drop or capillarity) and analysis time (0, 120 and 240s), depth of chamber (10 or 20μm) and field on motility variables were analysed by use of the CASA-mot system in goat sperm. Use of the drop-filling chambers resulted in greater values than capillarity-filling chambers for all sperm motility and kinetic variables, except for LIN (64.5% compared with 56.3% of motility for drop- and capillarity-filling chambers respectively, P<0.05). There were no significant differences in total sperm motility between different chamber depths, however, use of the 20μm-chambers resulted in greater sperm progressive motility rate, VSL and LIN, and less VCL and VAP than chambers with a lesser depth. There was less sperm motility and lesser values for kinetic variables as time that elapsed increased between sample loading and sperm evaluation. For sperm motility, use of droplet-loaded chambers resulted in similar values of MOT in all microscopic fields, but sperm motility assessed in capillarity-loaded chambers was less in the central fields than in the outermost microscopic fields. For goats, it is recommended that sperm motility be analysed using the CASA-mot system with a drop-loaded chamber within 2min after filling the chamber. Copyright © 2016 Elsevier B.V. All rights reserved.

Capillary-Driven Flow in Liquid Filaments Connecting Orthogonal Channels

NASA Technical Reports Server (NTRS)

Allen, Jeffrey S.

2005-01-01

Capillary phenomena plays an important role in the management of product water in PEM fuel cells because of the length scales associated with the porous layers and the gas flow channels. The distribution of liquid water within the network of gas flow channels can be dramatically altered by capillary flow. We experimentally demonstrate the rapid movement of significant volumes of liquid via capillarity through thin liquid films which connect orthogonal channels. The microfluidic experiments discussed provide a good benchmark against which the proper modeling of capillarity by computational models may be tested. The effect of surface wettability, as expressed through the contact angle, on capillary flow will also be discussed.

Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble

NASA Astrophysics Data System (ADS)

Carmelo, J. M. P.; Prosen, T.

2017-01-01

Whether in the thermodynamic limit, vanishing magnetic field h → 0, and nonzero temperature the spin stiffness of the spin-1/2 XXX Heisenberg chain is finite or vanishes within the grand-canonical ensemble remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we provide an upper bound on the stiffness and show that within that ensemble it vanishes for h → 0 in the thermodynamic limit of chain length L → ∞, at high temperatures T → ∞. Our approach uses a representation in terms of the L physical spins 1/2. For all configurations that generate the exact spin-S energy and momentum eigenstates such a configuration involves a number 2S of unpaired spins 1/2 in multiplet configurations and L - 2 S spins 1/2 that are paired within Msp = L / 2 - S spin-singlet pairs. The Bethe-ansatz strings of length n = 1 and n > 1 describe a single unbound spin-singlet pair and a configuration within which n pairs are bound, respectively. In the case of n > 1 pairs this holds both for ideal and deformed strings associated with n complex rapidities with the same real part. The use of such a spin 1/2 representation provides useful physical information on the problem under investigation in contrast to often less controllable numerical studies. Our results provide strong evidence for the absence of ballistic transport in the spin-1/2 XXX Heisenberg chain in the thermodynamic limit, for high temperatures T → ∞, vanishing magnetic field h → 0 and within the grand-canonical ensemble.

Reply to "Comment on 'Calculations for the one-dimensional soft Coulomb problem and the hard Coulomb limit' ".

PubMed

Gebremedhin, Daniel H; Weatherford, Charles A

2015-02-01

This is a response to the comment we received on our recent paper "Calculations for the one-dimensional soft Coulomb problem and the hard Coulomb limit." In that paper, we introduced a computational algorithm that is appropriate for solving stiff initial value problems, and which we applied to the one-dimensional time-independent Schrödinger equation with a soft Coulomb potential. We solved for the eigenpairs using a shooting method and hence turned it into an initial value problem. In particular, we examined the behavior of the eigenpairs as the softening parameter approached zero (hard Coulomb limit). The commenters question the existence of the ground state of the hard Coulomb potential, which we inferred by extrapolation of the softening parameter to zero. A key distinction between the commenters' approach and ours is that they consider only the half-line while we considered the entire x axis. Based on mathematical considerations, the commenters consider only a vanishing solution function at the origin, and they question our conclusion that the ground state of the hard Coulomb potential exists. The ground state we inferred resembles a δ(x), and hence it cannot even be addressed based on their argument. For the excited states, there is agreement with the fact that the particle is always excluded from the origin. Our discussion with regard to the symmetry of the excited states is an extrapolation of the soft Coulomb case and is further explained herein.

Multi-scale diffuse interface modeling of multi-component two-phase flow with partial miscibility

NASA Astrophysics Data System (ADS)

Kou, Jisheng; Sun, Shuyu

2016-08-01

In this paper, we introduce a diffuse interface model to simulate multi-component two-phase flow with partial miscibility based on a realistic equation of state (e.g. Peng-Robinson equation of state). Because of partial miscibility, thermodynamic relations are used to model not only interfacial properties but also bulk properties, including density, composition, pressure, and realistic viscosity. As far as we know, this effort is the first time to use diffuse interface modeling based on equation of state for modeling of multi-component two-phase flow with partial miscibility. In numerical simulation, the key issue is to resolve the high contrast of scales from the microscopic interface composition to macroscale bulk fluid motion since the interface has a nanoscale thickness only. To efficiently solve this challenging problem, we develop a multi-scale simulation method. At the microscopic scale, we deduce a reduced interfacial equation under reasonable assumptions, and then we propose a formulation of capillary pressure, which is consistent with macroscale flow equations. Moreover, we show that Young-Laplace equation is an approximation of this capillarity formulation, and this formulation is also consistent with the concept of Tolman length, which is a correction of Young-Laplace equation. At the macroscopical scale, the interfaces are treated as discontinuous surfaces separating two phases of fluids. Our approach differs from conventional sharp-interface two-phase flow model in that we use the capillary pressure directly instead of a combination of surface tension and Young-Laplace equation because capillarity can be calculated from our proposed capillarity formulation. A compatible condition is also derived for the pressure in flow equations. Furthermore, based on the proposed capillarity formulation, we design an efficient numerical method for directly computing the capillary pressure between two fluids composed of multiple components. Finally, numerical tests

Effects of Physical Activity and Inactivity on Muscle Fatigue

PubMed Central

Bogdanis, Gregory C.

2012-01-01

The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural, and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity, and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short-duration exercise as a time-efficient method to achieve both anaerobic and aerobic/endurance type adaptations. The factors that determine the fatigue profile of a muscle during intense exercise include muscle fiber composition, neuromuscular characteristics, high energy metabolite stores, buffering capacity, ionic regulation, capillarization, and mitochondrial density. Muscle fiber-type transformation during exercise training is usually toward the intermediate type IIA at the expense of both type I and IIx myosin heavy-chain isoforms. High-intensity training results in increases of both glycolytic and oxidative enzymes, muscle capillarization, improved phosphocreatine resynthesis and regulation of K+, H+, and lactate ions. Decreases of the habitual activity level due to injury or sedentary lifestyle result in partial or even compete reversal of the adaptations due to previous training, manifested by reductions in fiber cross-sectional area, decreased oxidative capacity, and capillarization. Complete immobilization due to injury results in markedly decreased force output and fatigue resistance. Muscle unloading reduces electromyographic activity and causes muscle atrophy and significant decreases in capillarization and oxidative enzymes activity. The last part of the review discusses the beneficial effects of intermittent high-intensity exercise training in patients with different health conditions to demonstrate the powerful effect of exercise on health and well being. PMID

[Features of the structure and parameters of the intra-alveolar septa in residents of Western Siberia].

PubMed

Shishkin, G S; Ustiuzhaninova, N V

1998-01-01

In inhabitants of Novosibirsk and Moscow district intraalveolar septum, the basic functional element of the lung consists of interstitial connective tissue and capillar network, limited with basement membranes, on which cells of epithelial lining are placed. There are no principal differences in septal structure between individuals from both regions. The majority of morphometric parameters are statistically similar, although certain peculiarities were noted in human subjects from Siberia, the most important of which is that air-blood barrier in them is 33% thinner than those in inhabitants of Moscow district. Majority of capillaries possess the air-blood barrier from both sides. This increases diffous capacity of the lungs and blood oxygenation level.

Measure-valued solutions to the complete Euler system revisited

NASA Astrophysics Data System (ADS)

Březina, Jan; Feireisl, Eduard

2018-06-01

We consider the complete Euler system describing the time evolution of a general inviscid compressible fluid. We introduce a new concept of measure-valued solution based on the total energy balance and entropy inequality for the physical entropy without any renormalization. This class of so-called dissipative measure-valued solutions is large enough to include the vanishing dissipation limits of the Navier-Stokes-Fourier system. Our main result states that any sequence of weak solutions to the Navier-Stokes-Fourier system with vanishing viscosity and heat conductivity coefficients generates a dissipative measure-valued solution of the Euler system under some physically grounded constitutive relations. Finally, we discuss the same asymptotic limit for the bi-velocity fluid model introduced by H.Brenner.

Vanishing testes syndrome-related osteoporosis and high cardio-metabolic risk in an adult male with long term untreated hypergonadotropic hypogonadism.

PubMed

Carsote, Mara; Capatina, Cristina; Valea, Ana; Dumitrascu, Anda

2016-02-01

The male hypogonadism-related bone mass loss is often under diagnosed. Peak bone mass is severely affected if the hypogonadism occurs during puberty and is left untreated. We present an interesting; almost bizarre case of a male with non-functional testes early during childhood and undiagnosed and untreated hypogonadism until his fifth decade of life. Forty six year male is referred for goitre, complaining of back pain. Phenotype suggested intersexuality: gynoid proportions, micropenis, no palpable testes into the scrotum, no facial or truncal hair. His medical history had been unremarkable until the previous year when primary hypothyroidism was diagnosed and levothyroxine replacement was initiated. Later, he was diagnosed with ischemic heart disease, with inaugural unstable angina. On admission, the testosterone was 0.2 ng/mL (normal: 1.7-7.8 ng/mL), FSH markedly increased (56 mUI/mL), with normal adrenal axis, and TSH (under thyroxine replacement). High bone turnover markers, and blood cholesterol, and impaired glucose tolerance were diagnosed. The testes were not present in the scrotum. Abdominal computed tomography suggested bilateral masses of 1.6 cm diameter within the abdominal fat that were removed but no gonadal tissue was confirmed histopathologically. Vanishing testes syndrome was confirmed. The central DXA showed lumbar bone mineral density of 0.905 g/cm2, Z-score of -2.9SD. The spine profile X-Ray revealed multiple thoracic vertebral fractures. Alendronate therapy together with vitamin D and calcium supplements and trans-dermal testosterone were started. Four decades of hypogonadism associate increased cardiac risk, as well as decreased bone mass and high fracture risk.

On consistency of hydrodynamic approximation for chiral media

NASA Astrophysics Data System (ADS)

Avdoshkin, A.; Kirilin, V. P.; Sadofyev, A. V.; Zakharov, V. I.

2016-04-01

We consider chiral liquids, that is liquids consisting of massless fermions and right-left asymmetric. In such media, one expects existence of electromagnetic current flowing along an external magnetic field, associated with the chiral anomaly. The current is predicted to be dissipation-free. We consider dynamics of chiral liquids, concentrating on the issues of possible instabilities and infrared sensitivity. Instabilities arise, generally speaking, already in the limit of vanishing electromagnetic constant, αel → 0. In particular, liquids with non-vanishing chiral chemical potential might decay into right-left asymmetric states containing vortices.

DIFFUSED SOLUTE-SOLVENT INTERFACE WITH POISSON-BOLTZMANN ELECTROSTATICS: FREE-ENERGY VARIATION AND SHARP-INTERFACE LIMIT.

PubMed

Li, B O; Liu, Yuan

A phase-field free-energy functional for the solvation of charged molecules (e.g., proteins) in aqueous solvent (i.e., water or salted water) is constructed. The functional consists of the solute volumetric and solute-solvent interfacial energies, the solute-solvent van der Waals interaction energy, and the continuum electrostatic free energy described by the Poisson-Boltzmann theory. All these are expressed in terms of phase fields that, for low free-energy conformations, are close to one value in the solute phase and another in the solvent phase. A key property of the model is that the phase-field interpolation of dielectric coefficient has the vanishing derivative at both solute and solvent phases. The first variation of such an effective free-energy functional is derived. Matched asymptotic analysis is carried out for the resulting relaxation dynamics of the diffused solute-solvent interface. It is shown that the sharp-interface limit is exactly the variational implicit-solvent model that has successfully captured capillary evaporation in hydrophobic confinement and corresponding multiple equilibrium states of underlying biomolecular systems as found in experiment and molecular dynamics simulations. Our phase-field approach and analysis can be used to possibly couple the description of interfacial fluctuations for efficient numerical computations of biomolecular interactions.

Palaeolimnological evidence of vulnerability of Lake Neusiedl (Austria) toward climate related changes since the last "vanished-lake" stage.

NASA Astrophysics Data System (ADS)

Tolotti, Monica; Milan, Manuela; Boscaini, Adriano; Soja, Gerhard; Herzig, Alois

2013-04-01

The palaeolimnological reconstruction of secular evolution of Euroepan Lakes with key socio-economical relevance respect to large (climate change) and local scale (land use, tourism) environmental changes, represents one of the objectives of the project EuLakes (European Lakes Under Environmental Stressors, Supporting lake governance to mitigate the impact of climate change, Reg. N. 2CE243P3), launched in 2010 within the Central European Inititiative. The project consortium comprises lakes of different morphology and prevalent human uses, including the meso-eutrophic Lake Neusiedl, the largest Austrian lake (total area 315 km2), and the westernmost shallow (mean depth 1.2 m) steppe lake of the Euro-Asiatic continent. The volume of Lake Neusiedl can potentially change over the years, in relation with changing balance between atmospheric precipitation and lake water evapotranspiration. Changing water budget, together with high lake salinity and turbidity, have important implications over the lake ecosystem. This contribution illustrates results of the multi-proxi palaeolimnological reconstruction of ecologial changes occurred in Lake Neusiedl during the last ca. 140 years, i.e. since the end of the last "vanished-lake" stage (1865-1871). Geochemical and biological proxies anticipate the increase in lake productivity of ca. 10 years (1950s) respect to what reported in the literature. Diatom species composition indicate a biological lake recovery in the late 1980s, and suggest a second increment in lake productivity since the late 1990s, possibly in relation with the progressive increase in the nitrogen input from agriculture. Abundance of diatoms typical of brackish waters indicated no significant long-term change in lake salinity, while variations in species toleranting dessiccation confirm the vulnerability of Lake Neusiedl toward climate-driven changes in the lake water balance. This fragility is aggravated by the the semi-arid climate conditions of the catchemnt

Soft beams: When capillarity induces axial compression

NASA Astrophysics Data System (ADS)

Neukirch, S.; Antkowiak, A.; Marigo, J.-J.

2014-01-01

We study the interaction of an elastic beam with a liquid drop in the case where bending and extensional effects are both present. We use a variational approach to derive equilibrium equations and constitutive relation for the beam. This relation is shown to include a term due to surface energy in addition to the classical Young's modulus term, leading to a modification of Hooke's law. At the triple point where solid, liquid, and vapor phases meet, we find that the external force applied on the beam is parallel to the liquid-vapor interface. Moreover, in the case where solid-vapor and solid-liquid interface energies do not depend on the extension state of the beam, we show that the extension in the beam is continuous at the triple point and that the wetting angle satisfies the classical Young-Dupré relation.

Soft beams: when capillarity induces axial compression.

PubMed

Neukirch, S; Antkowiak, A; Marigo, J-J

2014-01-01

We study the interaction of an elastic beam with a liquid drop in the case where bending and extensional effects are both present. We use a variational approach to derive equilibrium equations and constitutive relation for the beam. This relation is shown to include a term due to surface energy in addition to the classical Young's modulus term, leading to a modification of Hooke's law. At the triple point where solid, liquid, and vapor phases meet, we find that the external force applied on the beam is parallel to the liquid-vapor interface. Moreover, in the case where solid-vapor and solid-liquid interface energies do not depend on the extension state of the beam, we show that the extension in the beam is continuous at the triple point and that the wetting angle satisfies the classical Young-Dupré relation.

College-age twins: university admission policies / twin research: birth weight and neuromotor performance; transfusion syndrome markers; vanishing twins and fetal sex determination; mz twin discordance for wilson's disease / media: big at birth; planned separation of conjoined twins; x factor twins; Cinema: the identical.

PubMed

Segal, Nancy L

2014-12-01

There is a lack of research findings addressing the unique college admissions issues faced by twins and other multiples. The advantages and disadvantage twins face, as reported by college administrators, twins and families are reviewed. Next, recent research addressing twins' birth weight and neuromotor performance, transfusion syndrome markers, the vanishing twin syndrome and monozygotic (MZ) twin discordance for Wilson's disease is described. News items concerning the birth of unusually large twins, the planned separation of conjoined twins, twin participants in the X Factor games and a film, The Identical, are also summarized.

The vanishing limit of the square-well fluid: The adhesive hard-sphere model as a reference system

NASA Astrophysics Data System (ADS)

Largo, J.; Miller, M. A.; Sciortino, F.

2008-04-01

We report a simulation study of the gas-liquid critical point for the square-well potential, for values of well width δ as small as 0.005 times the particle diameter σ. For small δ, the reduced second virial coefficient at the critical point B2*c is found to depend linearly on δ. The observed weak linear dependence is not sufficient to produce any significant observable effect if the critical temperature Tc is estimated via a constant B2*c assumption, due to the highly nonlinear transformation between B2*c and Tc. This explains the previously observed validity of the law of corresponding states. The critical density ρc is also found to be constant when measured in units of the cube of the average distance between two bonded particles (1+0.5δ)σ. The possibility of describing the δ →0 dependence with precise functional forms provides improved accurate estimates of the critical parameters of the adhesive hard-sphere model.

The vanishing limit of the square-well fluid: the adhesive hard-sphere model as a reference system.

PubMed

Largo, J; Miller, M A; Sciortino, F

2008-04-07

We report a simulation study of the gas-liquid critical point for the square-well potential, for values of well width delta as small as 0.005 times the particle diameter sigma. For small delta, the reduced second virial coefficient at the critical point B2*c is found to depend linearly on delta. The observed weak linear dependence is not sufficient to produce any significant observable effect if the critical temperature Tc is estimated via a constant B2*c assumption, due to the highly nonlinear transformation between B2*c and Tc. This explains the previously observed validity of the law of corresponding states. The critical density rho c is also found to be constant when measured in units of the cube of the average distance between two bonded particles (1+0.5 delta)sigma. The possibility of describing the delta-->0 dependence with precise functional forms provides improved accurate estimates of the critical parameters of the adhesive hard-sphere model.

Vanishing Black College Students?

ERIC Educational Resources Information Center

Malveaux, Julianne

2005-01-01

This article asserts low graduation rates, a lack of information for those who do graduate, and a perceived hostile environment on some campuses cut the college matriculation rates of African American students, making them an endangered species on some campuses. It discusses the root causes and effects of the low population of African American…

Enceladus: a vanishing satellite

NASA Astrophysics Data System (ADS)

Czechowski, Leszek

2014-05-01

Enceladus, a satellite of Saturn, is the smallest celestial body in the Solar System where volcanic activity is observed. Every second, the mass of ~200 kg is ejecting into space. The size of the satellite directly after accretion (this body is referred here as proto-Enceladus) is unknown. It can be estimated in two ways. First, if the average mass outflow is equal to the present rate then the satellite's original mass was ~30% bigger than today. Second, we assume here that density of proto-Enceladus was equal to the present density of Mimas because they were formed in the same part of the nebula. Mimas is dead, so it preserves original composition. Both approaches give similar initial Enceladus' radius (~296 km) and its surface area (~1.1×106 km2). The present values are: 252 km and 7.99×105 km2. The loss of matter should lead to global compression of the crust. Typical effects of compression are: thrust faults, folding, and subduction. However, such forms are not dominant on Enceladus. We propose here special tectonic model that could explain this paradox. The volatiles escape from the hot region through the fractures forming plumes in the space. The loss of the volatiles results in a void, an instability, and motion of solid matter into hot region to fill the void in statu nascendi. The motion includes: Subsidence of the lithosphere of SPT. Flow of matter in the mantle. Motion of lithospheric plates adjacent to SPT towards the active region. If emerging void is being filled by the subsidence of SPT only, then the velocity of subsidence is ~0.05 mm·yr-1. However, all three types of motion are probably important, so the subsidence is slower but mantle flow and plates' motion also play a role in filling the void. Note that in our model reduction of the crust area is not a result of compression but it is a result of the plate sinking. Therefore the compressional surface features do not have to be dominant. Note also that we do not know the present age of the satellite surface. Age assessment depends on the assumed model of the flux of meteorites. For the lunar-like flux, cratered plains of Enceladus are 4.2 Gyr old, and only 1.7 Gyr old, if cometary impact rates are used (1,2). If 'cometary' chronology is correct then we have no data concerning 2/3 of Enceladus history. During that time there could be a number of activity cycles, and the total decrease of the surface area could be 300,000 km2. If our hypothesis is confirmed, then Enceladus will be an exceptional body, possibly representing a new class of celestial bodies: bodies decreasing as a result of endogenic activity. Are other bodies similar to Enceladus? Dione seems be a good candidate. Its activity is predicted and observed(3,4). Its gravity is too low to retain gases. Its present high density could be a result of partial loss of volatiles in the past. Moreover, it is in orbit-orbit resonance, so substantial tidal heating is possible. Acknowledgments This work was partially supported by the National Science Centre (grant 2011/01/B/ST10/06653). References and Notes: 1. J.R., Spencer, et al. Enceladus: An Active Cryovolcanic Satellite, in: M.K. Dougherty et al. (eds.), Saturn from Cassini-Huygens, Springer Science, (2009), p. 683. 2. K. Zahnle et al., Cratering rates in the outer Solar System. Icarus 163, 263 (2003). 3. JPL press release. Cassini finds hints of activity at Saturn moon Dione, http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20130529/ May, 29 (2013) 4. L. Czechowski, Parameterized model of convection driven by tidal and radiogenic heating. Adv. Space Res. 38, 788 (2006).

Vanishing tumor in pregnancy

PubMed Central

Vimal, M. V.; Budyal, Sweta; Kasliwal, Rajeev; Jagtap, Varsha S.; Lila, Anurag R.; Bandgar, Tushar; Menon, Padmavathy; Shah, Nalini S.

2012-01-01

A patient with microprolactinoma, who had two successful pregnancies, is described for management issues. First pregnancy was uneventful. During the second pregnancy, the tumor enlarged to macroprolactinoma with headache and blurring of vision which was managed successfully with bromocriptine. Post delivery, complete disappearance of the tumor was documented. PMID:23226664

Enceladus: a vanishing satellite

NASA Astrophysics Data System (ADS)

Czechowski, Leszek

Enceladus, a satellite of Saturn, is the smallest celestial body in the Solar System where volcanic activity is observed. Every second, the mass of 200 kg is ejecting into space. The size of the satellite directly after accretion (this body is referred here as proto-Enceladus) is unknown. It can be estimated in two ways. First, if the average mass outflow is equal to the present rate then the satellite’s original mass was 30% bigger than today. Second, we assume here that density of proto-Enceladus was equal to the present density of Mimas because they were formed in the same part of the nebula. Mimas is dead, so it preserves original composition. Both approaches give similar initial Enceladus’ radius ( 296 km) and its surface area ( 1.1×106 km2). The present values are: 252 km and 7.99×105 km2. The loss of matter should lead to global compression of the crust. Typical effects of compression are: thrust faults, folding, and subduction. However, such forms are not dominant on Enceladus. We propose here special tectonic model that could explain this paradox. The volatiles escape from the hot region through the fractures forming plumes in the space. The loss of the volatiles results in a void, an instability, and motion of solid matter into hot region to fill the void in statu nascendi. The motion includes: (i) Subsidence of the lithosphere of SPT. (ii) Flow of matter in the mantle. (iii) Motion of lithospheric plates adjacent to SPT towards the active region. If emerging void is being filled by the subsidence of SPT only, then the velocity of subsidence is 0.05 mm·yr-1. However, all three types of motion are probably important, so the subsidence is slower but mantle flow and plates’ motion also play a role in filling the void. Note that in our model reduction of the crust area is not a result of compression but it is a result of the plate sinking. Therefore the compressional surface features do not have to be dominant. Note also that we do not know the present age of the satellite surface. Age assessment depends on the assumed model of the flux of meteorites. For the lunar-like flux, cratered plains of Enceladus are 4.2 Gyr old, and only 1.7 Gyr old, if cometary impact rates are used (1, 2). If ‘cometary’ chronology is correct then we have no data concerning 2/3 of Enceladus history. During that time there could be a number of activity cycles, and the total decrease of the surface area could be 300,000 km2. If our hypothesis is confirmed, then Enceladus will be an exceptional body, possibly representing a new class of celestial bodies: bodies decreasing as a result of endogenic activity. Are other bodies similar to Enceladus? Dione seems be a good candidate. Its activity is predicted and observed (3, 4). Its gravity is too low to retain gases. Its present high density could be a result of partial loss of volatiles in the past. Moreover, it is in orbit-orbit resonance, so substantial tidal heating is possible. Acknowledgments This work was partially supported by the National Science Centre (grant 2011/01/B/ST10/06653). References and Notes: 1. J.R., Spencer, et al. Enceladus: An Active Cryovolcanic Satellite, in: M.K. Dougherty et al. (eds.), Saturn from Cassini-Huygens, Springer Science, (2009), p. 683. 2. K. Zahnle et al., Cratering rates in the outer Solar System. Icarus 163, 263 (2003). 3. JPL press release. Cassini finds hints of activity at Saturn moon Dione, http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20130529/ May, 29 (2013) 4. L. Czechowski, Parameterized model of convection driven by tidal and radiogenic heating. Adv. Space Res. 38, 788 (2006).

Vanishing White Matter Disease

MedlinePlus

... which can result in lack of menstrual periods, fertility problems and early menopause. Mental decline may be ... production, especially the decrease in protein synthesis during stress conditions, such as fever and infection. It is ...

Paperless or vanishing society

NASA Astrophysics Data System (ADS)

Turner Luke, Joy

2002-06-01

In the 1940s color photography became available and within a few years, extremely popular. As people switched from black and white photographs made with the old metallic silver process to the new color films, pictures taken to record their lives and families began a slow disappearing act. The various color processes, coupled with the substrates they were printed on, affected their longevity, but many color photographs taken from the late 1950s through the 1970s, and even into the 1980s, faded not only when exposed to the light, but also when stored in the dark. Henry Wilhelm's excellent book 'The Permanence and Care of Color Photographs' documents this history in detail. Today we are making another transition in the storage of pictures and information. There are questions about the longevity of different types of digital storage, and also of the images printed by various types of inkjet printers, or by laser printers using colored toners. Very expensive and very beautiful works of art produced on Iris printers are appearing in art exhibitions. Some of these are referred to as Giclee prints and are offered on excellent papers. Artists are told the prints will last a lifetime; and if by change they don't it is only necessary to make another print. Henry Wilhelm has begun to test and rate these images for lightfastness; however, his test method was developed for examining longevity in colored photographs. It is of interest to find out how these prints will hold up in the tests required for fine art materials. Thus far companies producing digital inks and printers have not invested the time and money necessary to develop an American Society for Testing and Materials (ASTM) standard method for evaluating the lightfastness of digital prints. However, it is possible to use ASTM D 5383, Standard Practice for Visual Determination of the Lightfastness of Art Materials by Art Technologists, to pinpoint colors that will fade in a short time, even though the test is not as severe as ASTM D 4303, which is used to rate the lightfastness of artists's paint.

The Vanishing School Board.

ERIC Educational Resources Information Center

Chalker, Donald M.; Haynes, Richard M.

1997-01-01

Now that school boards have been replaced by parent advisory councils, there is virtually no local school governance in New Brunswick, Canada. Factors leading to school boards' demise include neglected democratic institutions, failure to understand local boards' needs, less qualified members, boards' failure to protect their special…

The Vanishing Neighborhood Campus

ERIC Educational Resources Information Center

Halfond, Jay A.

2012-01-01

Only a generation ago, universities like Northeastern and Boston University had campuses strategically sprinkled throughout eastern Massachusetts. Lesley University offered graduate education programs across the U.S. BU had a contract with the U.S. Army to deliver master's programs on military bases throughout Europe. Mega-high-tech companies,…

The Earth's Vanishing Species.

ERIC Educational Resources Information Center

USA Today, 1981

1981-01-01

Elaborates on the problem of expanding human activity to the world's plant and animal species. Concludes that preserving an individual species is largely a waste of time and effort and that the best way to protect the most species of plants and animals is to save their environments over large tracts of land. (DB)

The scattering analog for infiltration in porous media

NASA Astrophysics Data System (ADS)

Philip, J. R.

1989-11-01

This review takes the form of a set of Chinese boxes. The outermost box gives a brief general account of modem developments in the mathematical physics of unsaturated flow in soils and porous media. This provides the necessary foundations for the second box, which describes the quasi-linear analysis of steady multidimensional unsaturated flow, which is an essential prerequisite to the analog. Only then can we proceed to the innermost box, devoted to our major theme. An exact analog exists between steady quasi-linear flow in unsaturated soils and porous media and the scattering of plane pulses, and the analog carries over to the scattering of plane harmonic waves. Numerous established results, and powerful techniques such as Watson transforms, far-field scattering functions, and optical theorems, become available for the solution and understanding of problems of multidimensional infiltration. These are needed, in particular, to provide the asymptotics of the physically interesting and practically important limit of flows strongly dominated by gravity, with capillary effects weak but nonzero. This is the limit of large s, where s is a characteristic length of the water supply surface normalized with respect to the sorptive length of the soil. These problems are singular in the sense that ignoring capillarity gives a totally incorrect picture of the wetted region. In terms of the optical analog, neglecting capillarity is equivalent to using geometrical optics, with coherent shadows projected to infinity. When exact solutions involve exotic functions, difficulties of both analysis and series summation may be avoided through use of small-s and large-s expansions provided by the analog. Numerous examples are given of solutions obtained through the analog. The scope for extending the application to flows from surface sources, to anisotropic and heterogeneous media, to unsteady flows, and to linear convection-diffusion processes in general is described briefly.

Weak limit of the three-state quantum walk on the line

NASA Astrophysics Data System (ADS)

Falkner, Stefan; Boettcher, Stefan

2014-07-01

We revisit the one-dimensional discrete time quantum walk with three states and the Grover coin, the simplest model that exhibits localization in a quantum walk. We derive analytic expressions for the localization and a long-time approximation for the entire probability density function (PDF). We find the possibility for asymmetric localization to the extreme that it vanishes completely on one site of the initial conditions. We also connect the time-averaged approximation of the PDF found by Inui et al. [Phys. Rev. E 72, 056112 (2005), 10.1103/PhysRevE.72.056112] to a spatial average of the walk. We show that this smoothed approximation predicts moments of the real PDF accurately.

Multi-scale diffuse interface modeling of multi-component two-phase flow with partial miscibility

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

Kou, Jisheng; Sun, Shuyu, E-mail: shuyu.sun@kaust.edu.sa; School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an 710049

2016-08-01

In this paper, we introduce a diffuse interface model to simulate multi-component two-phase flow with partial miscibility based on a realistic equation of state (e.g. Peng–Robinson equation of state). Because of partial miscibility, thermodynamic relations are used to model not only interfacial properties but also bulk properties, including density, composition, pressure, and realistic viscosity. As far as we know, this effort is the first time to use diffuse interface modeling based on equation of state for modeling of multi-component two-phase flow with partial miscibility. In numerical simulation, the key issue is to resolve the high contrast of scales from themore » microscopic interface composition to macroscale bulk fluid motion since the interface has a nanoscale thickness only. To efficiently solve this challenging problem, we develop a multi-scale simulation method. At the microscopic scale, we deduce a reduced interfacial equation under reasonable assumptions, and then we propose a formulation of capillary pressure, which is consistent with macroscale flow equations. Moreover, we show that Young–Laplace equation is an approximation of this capillarity formulation, and this formulation is also consistent with the concept of Tolman length, which is a correction of Young–Laplace equation. At the macroscopical scale, the interfaces are treated as discontinuous surfaces separating two phases of fluids. Our approach differs from conventional sharp-interface two-phase flow model in that we use the capillary pressure directly instead of a combination of surface tension and Young–Laplace equation because capillarity can be calculated from our proposed capillarity formulation. A compatible condition is also derived for the pressure in flow equations. Furthermore, based on the proposed capillarity formulation, we design an efficient numerical method for directly computing the capillary pressure between two fluids composed of multiple components. Finally

Topological transport from a black hole

NASA Astrophysics Data System (ADS)

Melnikov, Dmitry

2018-03-01

In this paper the low temperature zero-frequency transport in a 2 + 1-dimensional theory dual to a dyonic black hole is discussed. It is shown that transport exhibits topological features: the transverse electric and heat conductivities satisfy the Wiedemann-Franz law of free electrons; the direct heat conductivity is measured in units of the central charge of CFT2+1, while the direct electric conductivity vanishes; the thermoelectric conductivity is non-zero at vanishing temperature, while the O (T) behavior, controlled by the Mott relation, is subleading. Provided that the entropy of the black hole, and the dual system, is non-vanishing at T = 0, the observations indicate that the dyonic black hole describes a ħ → 0 limit of a highly degenerate topological state, in which the black hole charge measures the density of excited non-abelian quasiparticles. The holographic description gives further evidence that non-abelian nature of quasiparticles can be determined by the low temperature behavior of the thermoelectric transport.

7 CFR 1400.204 - Limited partnerships, limited liability partnerships, limited liability companies, corporations...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Limited partnerships, limited liability partnerships..., limited liability partnerships, limited liability companies, corporations, and other similar legal entities. (a) A limited partnership, limited liability partnership, limited liability company, corporation...

From elasticity to capillarity in soft materials indentation

NASA Astrophysics Data System (ADS)

Pham, Jonathan T.; Schellenberger, Frank; Kappl, Michael; Butt, Hans-Jürgen

2017-06-01

For soft materials with Young's moduli below 100 kPa, quantifying mechanical and interfacial properties by small scale indentation is challenging because in addition to adhesion and elasticity, surface tension plays a critical role. Until now, microscale contact of very soft materials has only been studied by static experiments under zero external loading. Here we introduce a combination of the colloidal probe technique and confocal microscopy to characterize the force-indentation and force-contact radius relationships during microindentation of soft silicones. We confirm that the widespread Johnson-Kendall-Roberts theory must be extended to predict the mechanical contact for soft materials. Typically a liquid component is found within very soft materials. With a simple analytical model, we illustrate that accounting for this liquid surface tension can capture the contact behavior. Our results highlight the importance of considering liquid that is often associated with soft materials during small scale contact.

The electroosmotic droplet switch: countering capillarity with electrokinetics.

PubMed

Vogel, Michael J; Ehrhard, Peter; Steen, Paul H

2005-08-23

Electroosmosis, originating in the double-layer of a small liquid-filled pore (size R) and driven by a voltage V, is shown to be effective in pumping against the capillary pressure of a larger liquid droplet (size B) provided the dimensionless parameter sigmaR(2)/epsilon|zeta|VB is small enough. Here sigma is surface tension of the droplet liquid/gas interface, epsilon is the liquid dielectric constant, and zeta is the zeta potential of the solid/liquid pair. As droplet size diminishes, the voltage required to pump electroosmotically scales as V approximately R(2)/B. Accordingly, the voltage needed to pump against smaller higher-pressure droplets can actually decrease provided the pump poresize scales down with droplet size appropriately. The technological implication of this favorable scaling is that electromechanical transducers made of moving droplets, so-called "droplet transducers," become feasible. To illustrate, we demonstrate a switch whose bistable energy landscape derives from the surface energy of a droplet-droplet system and whose triggering derives from the electroosmosis effect. The switch is an electromechanical transducer characterized by individual addressability, fast switching time with low voltage, and no moving solid parts. We report experimental results for millimeter-scale droplets to verify key predictions of a mathematical model of the switch. With millimeter-size water droplets and micrometer-size pores, 5 V can yield switching times of 1 s. Switching time scales as B(3)/VR(2). Two possible "grab-and-release" applications of arrays of switches are described. One mimics the controlled adhesion of an insect, the palm beetle; the other uses wettability to move a particle along a trajectory.

Miscibility Gap Closure, Interface Morphology, and Phase Microstructure of 3D Li xFePO 4 Nanoparticles from Surface Wetting and Coherency Strain

DOE PAGES

Welland, Michael J.; Karpeyev, Dmitry; O’Connor, Devin T.; ...

2015-09-10

We study the mesoscopic effects which suppress phase-segregation in Li xFePO 4 nanoparticles using a multiphysics phase-field model implement on a high performance cluster. We simulate 3D spherical particles of radii from 3nm to 40nm and examine the equilibrium microstructure and voltage profiles as a they depend on size and overall lithiation. The model includes anisotropic, concentration-dependent elastic moduli, misfit strain, and facet dependent surface wetting within a Cahn-Hilliard formulation. Here, we find that the miscibility gap vanishes for particles of radius ~ 5 nm, and the solubility limits change with overall particle lithiation. The corresponding voltage plateau, indicative ofmore » phase-segregation, changes in extent and also vanishes. Surface wetting is found to have a strong effect on stabilizing a variety of microstructures, exaggerating the shifting of solubility limits, and shortening the voltage plateau.« less

All-Printed, Self-Aligned Carbon Nanotube Thin-Film Transistors on Imprinted Plastic Substrates.

PubMed

Song, Donghoon; Zare Bidoky, Fazel; Hyun, Woo Jin; Walker, S Brett; Lewis, Jennifer A; Frisbie, C Daniel

2018-05-09

We present a self-aligned process for printing thin-film transistors (TFTs) on plastic with single-walled carbon nanotube (SWCNT) networks as the channel material. The SCALE (self-aligned capillarity-assisted lithography for electronics) process combines imprint lithography with inkjet printing. Specifically, inks are jetted into imprinted reservoirs, where they then flow into narrow device cavities due to capillarity. Here, we incorporate a composite high- k gate dielectric and an aligned conducting polymer gate electrode in the SCALE process to enable a smaller areal footprint than prior designs that yields low-voltage SWCNT TFTs with average p-type carrier mobilities of 4 cm 2 /V·s and ON/OFF current ratios of 10 4 . Our work demonstrates the promising potential of the SCALE process to fabricate SWCNT-based TFTs with favorable I- V characteristics on plastic substrates.

Scaling of the polarization amplitude in quantum many-body systems in one dimension

NASA Astrophysics Data System (ADS)

Kobayashi, Ryohei; Nakagawa, Yuya O.; Fukusumi, Yoshiki; Oshikawa, Masaki

2018-04-01

Resta proposed a definition of the electric polarization in one-dimensional systems in terms of the ground-state expectation value of the large gauge transformation operator. Vanishing of the expectation value in the thermodynamic limit implies that the system is a conductor. We study Resta's polarization amplitude (expectation value) in the S =1 /2 XXZ chain and its several generalizations, in the gapless conducting Tomonaga-Luttinger liquid phase. We obtain an analytical expression in the lowest-order perturbation theory about the free fermion point (XY chain) and an exact result for the Haldane-Shastry model with long-range interactions. We also obtain numerical results, mostly using the exact diagonalization method. We find that the amplitude exhibits a power-law scaling in the system size (chain length) and vanishes in the thermodynamic limit. On the other hand, the exponent depends on the model even when the low-energy limit is described by the Tomonaga-Luttinger liquid with the same Luttinger parameter. We find that a change in the exponent occurs when the Umklapp term(s) are eliminated, suggesting the importance of the Umklapp terms.

Limiter

DOEpatents

Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

1984-10-19

A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

A Course in Colloid and Surface Science.

ERIC Educational Resources Information Center

Scamehorn, John F.

1984-01-01

Describes a course for chemical engineers, chemists, and petroleum engineers that focuses on colloid and surface science. Major topic areas in the course include capillarity, surface thermodynamics, adsorption contact angle, micelle formation, solubilization in micelles, emulsions, foams, and applications. (JN)

The hype cycle in 3D displays: inherent limits of autostereoscopy

NASA Astrophysics Data System (ADS)

Grasnick, Armin

2013-06-01

Since a couple of years, a renaissance of 3dimensional cinema can be observed. Even though the stereoscopy was quite popular within the last 150 years, the 3d cinema has disappeared and re-established itself several times. The first boom in the late 19th century stagnated and vanished after a few years of success, the same happened again in 50's and 80's of the 20th century. With the commercial success of the 3d blockbuster "Avatar" in 2009, at the latest, it is obvious that the 3d cinema is having a comeback. How long will it last this time? There are already some signs of a declining interest in 3d movies, as the discrepancy between expectations and the results delivered becomes more evident. From the former hypes it is known: After an initial phase of curiosity (high expectations and excessive fault tolerance), a phase of frustration and saturation (critical analysis and subsequent disappointment) will follow. This phenomenon is known as "Hype Cycle" The everyday experienced evolution of technology has conditioned the consumers. The expectation "any technical improvement will preserve all previous properties" cannot be fulfilled with present 3d technologies. This is an inherent problem of stereoscopy and autostereoscopy: The presentation of an additional dimension caused concessions in relevant characteristics (i.e. resolution, brightness, frequency, viewing area) or leads to undesirable physical side effects (i.e. subjective discomfort, eye strain, spatial disorientation, feeling of nausea). It will be verified that the 3d apparatus (3d glasses or 3d display) is also the source for these restrictions and a reason for decreasing fascination. The limitations of present autostereoscopic technologies will be explained.

Limiter

DOEpatents

Cohen, Samuel A.; Hosea, Joel C.; Timberlake, John R.

1986-01-01

A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

Smashing Bubbles and Vanishing Sugar.

ERIC Educational Resources Information Center

Ward, Alan

1979-01-01

Science activities with soap bubbles for primary school children are described in this article. Another activity involves children in determining the whereabouts of sugar as it dissolves in water. (SA)

Rural Blacks--A Vanishing Population.

ERIC Educational Resources Information Center

Jones, Lewis W.; Lee, Everett S.

The rural Negro population has been of public concern since the slave status was defined and an ideological defense of that status began to take shape. When slavery ended, a definition of the Negro status in custom and in law was undertaken wherever Negro people were concentrated. Controls were devised to "keep the Negro in his place."…

The vanishing cryovolcanoes of Ceres

USGS Publications Warehouse

Sori, Michael M.; Byrne, Shane; Bland, Michael T.; Bramson, Ali; Ermakov, Anton; Hamilton, Christoper; Otto, Katharina; Ruesch, Ottaviano; Russell, Christopher

2017-01-01

Ahuna Mons is a 4 km tall mountain on Ceres interpreted as a geologically young cryovolcanic dome. Other possible cryovolcanic features are more ambiguous, implying that cryovolcanism is only a recent phenomenon or that other cryovolcanic structures have been modified beyond easy identification. We test the hypothesis that Cerean cryovolcanic domes viscously relax, precluding ancient domes from recognition. We use numerical models to predict flow velocities of Ahuna Mons to be 10–500 m/Myr, depending upon assumptions about ice content, rheology, grain size, and thermal parameters. Slower flow rates in this range are sufficiently fast to induce extensive relaxation of cryovolcanic structures over 108–109 years, but gradual enough for Ahuna Mons to remain identifiable today. Positive topographic features, including a tholus underlying Ahuna Mons, may represent relaxed cryovolcanic structures. A composition for Ahuna Mons of >40% ice explains the observed distribution of cryovolcanic structures because viscous relaxation renders old cryovolcanoes unrecognizable.

The Vanishing Higher-Education Reporter

ERIC Educational Resources Information Center

Whitmire, Richard

2008-01-01

As the Internet continues to drain readers and advertising, newspapers are left with no choice but to cut back on coverage. Many papers have settled on higher education as an expendable beat. At the National Education Writers Association, which represents education reporters and editors around the country, the e-mail list for elementary- and…

An Onsager Singularity Theorem for Turbulent Solutions of Compressible Euler Equations

NASA Astrophysics Data System (ADS)

Drivas, Theodore D.; Eyink, Gregory L.

2017-12-01

We prove that bounded weak solutions of the compressible Euler equations will conserve thermodynamic entropy unless the solution fields have sufficiently low space-time Besov regularity. A quantity measuring kinetic energy cascade will also vanish for such Euler solutions, unless the same singularity conditions are satisfied. It is shown furthermore that strong limits of solutions of compressible Navier-Stokes equations that are bounded and exhibit anomalous dissipation are weak Euler solutions. These inviscid limit solutions have non-negative anomalous entropy production and kinetic energy dissipation, with both vanishing when solutions are above the critical degree of Besov regularity. Stationary, planar shocks in Euclidean space with an ideal-gas equation of state provide simple examples that satisfy the conditions of our theorems and which demonstrate sharpness of our L 3-based conditions. These conditions involve space-time Besov regularity, but we show that they are satisfied by Euler solutions that possess similar space regularity uniformly in time.

Elasto-capillary torsion at a liquid interface

NASA Astrophysics Data System (ADS)

Oratis, Alexandros; Farmer, Timothy; Bird, James

2016-11-01

When a liquid drop wets a solid, the droplet typically spreads over the solid. By contrast, for sufficiently compliant solids, the solid can instead spread around the drop. This wrapping phenomenon has been exploited to assemble 3-dimensional structures from 2-dimensional sheets, a process often referred to as capillary origami. Although existing studies of this self-assembly have demonstrated bending and folding, methods of inducing spontaneous twisting by means of capillarity are less clear. Here we demonstrate that spontaneous twist can be initiated in a compliant solid through a combination of surface chemistry and capillarity. Experimentally, we measure the angle of twist on a surface with binary patterns of surface wettability as we vary the solid's geometric and material properties. We develop a scaling law to relate this angle of twist to the elastic and interfacial properties, which compares well with our experimental results.

Statistical mechanics of two-dimensional shuffled foams: Geometry-topology correlation in small or large disorder limits

NASA Astrophysics Data System (ADS)

Durand, Marc; Kraynik, Andrew M.; van Swol, Frank; Käfer, Jos; Quilliet, Catherine; Cox, Simon; Ataei Talebi, Shirin; Graner, François

2014-06-01

Bubble monolayers are model systems for experiments and simulations of two-dimensional packing problems of deformable objects. We explore the relation between the distributions of the number of bubble sides (topology) and the bubble areas (geometry) in the low liquid fraction limit. We use a statistical model [M. Durand, Europhys. Lett. 90, 60002 (2010), 10.1209/0295-5075/90/60002] which takes into account Plateau laws. We predict the correlation between geometrical disorder (bubble size dispersity) and topological disorder (width of bubble side number distribution) over an extended range of bubble size dispersities. Extensive data sets arising from shuffled foam experiments, surface evolver simulations, and cellular Potts model simulations all collapse surprisingly well and coincide with the model predictions, even at extremely high size dispersity. At moderate size dispersity, we recover our earlier approximate predictions [M. Durand, J. Kafer, C. Quilliet, S. Cox, S. A. Talebi, and F. Graner, Phys. Rev. Lett. 107, 168304 (2011), 10.1103/PhysRevLett.107.168304]. At extremely low dispersity, when approaching the perfectly regular honeycomb pattern, we study how both geometrical and topological disorders vanish. We identify a crystallization mechanism and explore it quantitatively in the case of bidisperse foams. Due to the deformability of the bubbles, foams can crystallize over a larger range of size dispersities than hard disks. The model predicts that the crystallization transition occurs when the ratio of largest to smallest bubble radii is 1.4.

Periodic assessment of plasma sFlt-1 and PlGF concentrations and its association with placental morphometry in gestational hypertension (GH) - a prospective follow-up study.

PubMed

Jeevaratnam, Kamalan; Nadarajah, Vishna Devi; Judson, John Paul; Nalliah, Sivalingam; Abdullah, Mohd Farouk

2010-09-28

Hypertensive disorders in pregnancy contributes to about 12% of maternal deaths in Malaysia and similarly worldwide. Early detection and adequate management are preventable strategies. Biochemical markers of abnormal angiogenesis would be more specific in early detection than routine blood pressure and proteinuria measurements. The aim of this study was to estimate maternal plasma PlGF and sFlt-1 levels in pregnant women with gestational hypertension at three intervals of pregnancy and correlate these biomarker levels with placental morphometry. Venous blood samples (antepartum, intrapartum and post partum periods) were drawn to estimate for sFlt-1 and PlGF levels while placental tissue samples were examined for placental morphometry. PlGF levels were lower in gestational hypertension (GH) compared to normotensive during antepartum and intrapartum period, whereas sFlt-1 levels were elevated in GH at antepartum, intrapartum and postpartum intervals during pregnancy. An inverse relationship between these two biomarkers was observed through correlation analysis. PlGF levels were inversely correlated with total villous surface area of the placental periphery (TCsa-C) and villous capillarization (VC-C) of the placental periphery. We established periodic values of for sFlt-1 and PlGF levels for the first time in an ethnically diverse Malaysian setting. We suggest the development of GH in women is related to defective capillarization. In demonstrating periodic changes, this study suggest the possibility of developing GH and other long term health complications as a result of prolonged exposure to sFlt-1. The correlation between PlGF levels and morphometric findings also support possible capillarization defect.

Operation Everest II and the 1978 Habeler/Messner ascent of Everest without bottled O2: what might they have in common?

PubMed

Wagner, Peter D

2017-12-01

In 1978, Peter Habeler and Reinhold Messner climbed Everest without supplemental O 2 . Subsequently, Oelz et al. (Oelz O, Howald H, Di Prampero PE, Hoppeler H, Claassen H, Jenni R, Bühlmann A, Ferretti G, Brückner JC, Veicsteinas A, Gussoni M, Cerretelli P. J Appl Physiol (1985) 60: 1734-1742, 1986) assessed their cardiopulmonary function, finding no advantageous physiological attributes to explain their success, and leading West (West JB. High Life: A History of High-Altitude Physiology and Medicine. New York: Oxford University, 1998) to suggest that grit and determination were more important. In 1985, Charlie Houston, John Sutton, and Al Cymerman hosted a scientific project assessing a simulated ascent of Everest (OE II) at the U.S. Army Research Institute of Environmental Medicine. Included were measurements of O 2 transport. In particular, mixed venous Po 2 was measured at/near maximal exercise, for calculating pulmonary O 2 -diffusing capacity. A serendipitous observation was made: while both V̇o 2max and mixed venous Po 2 fell with altitude (as expected), it was how they fell-in direct proportion-that was remarkable. It later became clear that this reflected diffusion limitation of O 2 transport from muscle microvessels to the mitochondria, and that this last step in O 2 transport plays a major role in limiting V̇o 2max . Thus, how Habeler and Messner made it up Everest without bottled O 2 and no special cardiopulmonary attributes might be explained if their muscle O 2 -diffusing capacity, which depends largely on muscle capillarity, was unusually high. Oelz et al. mention that muscle capillary density was substantially-40%-above normal, but did not suggest that this accounted for the climbers' success. Therefore, high muscle capillarity, enhancing diffusive unloading of O 2 , may have been a major enabling physiological attribute for Habeler and Messner and that OE II, by chance, played a key role in bringing this to light.

Thermal smoothing of rough surfaces in vacuo

NASA Technical Reports Server (NTRS)

Wahl, G.

1986-01-01

The derivation of equations governing the smoothing of rough surfaces, based on Mullins' (1957, 1960, and 1963) theories of thermal grooving and of capillarity-governed solid surface morphology is presented. As an example, the smoothing of a one-dimensional sine-shaped surface is discussed.

The Longibrachiatum Clade of Trichoderma: a revision with new species

USDA-ARS?s Scientific Manuscript database

The Longibrachiatum Clade of Trichoderma is revised. Eight new species are described (T. aethiopicum, T. capillare, T. flagellatum, T. gillesii, T. gracile, T. pinnatum, T. saturnisporopsis, T. solani). The twenty-one species known to belong to the Longibrachiatum Clade are included in a synoptic ke...

Casimir free energy of dielectric films: classical limit, low-temperature behavior and control.

PubMed

Klimchitskaya, G L; Mostepanenko, V M

2017-07-12

The Casimir free energy of dielectric films, both free-standing in vacuum and deposited on metallic or dielectric plates, is investigated. It is shown that the values of the free energy depend considerably on whether the calculation approach used neglects or takes into account the dc conductivity of film material. We demonstrate that there are material-dependent and universal classical limits in the former and latter cases, respectively. The analytic behavior of the Casimir free energy and entropy for a free-standing dielectric film at low temperature is found. According to our results, the Casimir entropy goes to zero when the temperature vanishes if the calculation approach with neglected dc conductivity of a film is employed. If the dc conductivity is taken into account, the Casimir entropy takes the positive value at zero temperature, depending on the parameters of a film, i.e. the Nernst heat theorem is violated. By considering the Casimir free energy of SiO 2 and Al 2 O 3 films deposited on a Au plate in the framework of two calculation approaches, we argue that physically correct values are obtained by disregarding the role of dc conductivity. A comparison with the well known results for the configuration of two parallel plates is made. Finally, we compute the Casimir free energy of SiO 2 , Al 2 O 3 and Ge films deposited on high-resistivity Si plates of different thicknesses and demonstrate that it can be positive, negative and equal to zero. The effect of illumination of a Si plate with laser light is considered. Possible applications of the obtained results to thin films used in microelectronics are discussed.

Casimir free energy of dielectric films: classical limit, low-temperature behavior and control

NASA Astrophysics Data System (ADS)

Klimchitskaya, G. L.; Mostepanenko, V. M.

2017-07-01

The Casimir free energy of dielectric films, both free-standing in vacuum and deposited on metallic or dielectric plates, is investigated. It is shown that the values of the free energy depend considerably on whether the calculation approach used neglects or takes into account the dc conductivity of film material. We demonstrate that there are material-dependent and universal classical limits in the former and latter cases, respectively. The analytic behavior of the Casimir free energy and entropy for a free-standing dielectric film at low temperature is found. According to our results, the Casimir entropy goes to zero when the temperature vanishes if the calculation approach with neglected dc conductivity of a film is employed. If the dc conductivity is taken into account, the Casimir entropy takes the positive value at zero temperature, depending on the parameters of a film, i.e. the Nernst heat theorem is violated. By considering the Casimir free energy of SiO2 and Al2O3 films deposited on a Au plate in the framework of two calculation approaches, we argue that physically correct values are obtained by disregarding the role of dc conductivity. A comparison with the well known results for the configuration of two parallel plates is made. Finally, we compute the Casimir free energy of SiO2, Al2O3 and Ge films deposited on high-resistivity Si plates of different thicknesses and demonstrate that it can be positive, negative and equal to zero. The effect of illumination of a Si plate with laser light is considered. Possible applications of the obtained results to thin films used in microelectronics are discussed.

Limits on fundamental limits to computation.

PubMed

Markov, Igor L

2014-08-14

An indispensable part of our personal and working lives, computing has also become essential to industries and governments. Steady improvements in computer hardware have been supported by periodic doubling of transistor densities in integrated circuits over the past fifty years. Such Moore scaling now requires ever-increasing efforts, stimulating research in alternative hardware and stirring controversy. To help evaluate emerging technologies and increase our understanding of integrated-circuit scaling, here I review fundamental limits to computation in the areas of manufacturing, energy, physical space, design and verification effort, and algorithms. To outline what is achievable in principle and in practice, I recapitulate how some limits were circumvented, and compare loose and tight limits. Engineering difficulties encountered by emerging technologies may indicate yet unknown limits.

High-quality imaging in environmental scanning electron microscopy--optimizing the pressure limiting system and the secondary electron detection of a commercially available ESEM.

PubMed

Fitzek, H; Schroettner, H; Wagner, J; Hofer, F; Rattenberger, J

2016-04-01

In environmental scanning electron microscopy applications in the kPa regime are of increasing interest for the investigation of wet and biological samples, because neither sample preparation nor extensive cooling are necessary. Unfortunately, the applications are limited by poor image quality. In this work the image quality at high pressures of a FEI Quanta 600 (field emission gun) and a FEI Quanta 200 (thermionic gun) is greatly improved by optimizing the pressure limiting system and the secondary electron (SE) detection system. The scattering of the primary electron beam strongly increases with pressure and thus the image quality vanishes. The key to high-image quality at high pressures is to reduce scattering as far as possible while maintaining ideal operation conditions for the SE-detector. The amount of scattering is reduced by reducing both the additional stagnation gas thickness (aSGT) and the environmental distance (ED). A new aperture holder is presented that significantly reduces the aSGT while maintaining the same field-of-view (FOV) as the original design. With this aperture holder it is also possible to make the aSGT even smaller at the expense of a smaller FOV. A new blade-shaped SE-detector is presented yielding better image quality than usual flat SE-detectors. The electrode of the new SE detector is positioned on the sample table, which allows the SE-detector to operate at ideal conditions regardless of pressure and ED. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Logarithmic corrections to black hole entropy: the non-BPS branch

NASA Astrophysics Data System (ADS)

Castro, Alejandra; Godet, Victor; Larsen, Finn; Zeng, Yangwenxiao

2018-05-01

We compute the leading logarithmic correction to black hole entropy on the non-BPS branch of 4D N≥2 supergravity theories. This branch corresponds to finite temperature black holes whose extremal limit does not preserve supersymmetry, such as the D0 - D6 system in string theory. Starting from a black hole in minimal Kaluza-Klein theory, we discuss in detail its embedding into N=8 , 6, 4, 2 supergravity, its spectrum of quadratic fluctuations in all these environments, and the resulting quantum corrections. We find that the c-anomaly vanishes only when N≥6 , in contrast to the BPS branch where c vanishes for all N≥2 . We briefly discuss potential repercussions this feature could have in a microscopic description of these black holes.

High frequency lateral flow affinity assay using superparamagnetic nanoparticles

NASA Astrophysics Data System (ADS)

Lago-Cachón, D.; Rivas, M.; Martínez-García, J. C.; Oliveira-Rodríguez, M.; Blanco-López, M. C.; García, J. A.

2017-02-01

Lateral flow assay is one of the simplest and most extended techniques in medical diagnosis for point-of-care testing. Although it has been traditionally a positive/negative test, some work has been lately done to add quantitative abilities to lateral flow assay. One of the most successful strategies involves magnetic beads and magnetic sensors. Recently, a new technique of superparamagnetic nanoparticle detection has been reported, based on the increase of the impedance induced by the nanoparticles on a RF-current carrying copper conductor. This method requires no external magnetic field, which reduces the system complexity. In this work, nitrocellulose membranes have been installed on the sensor, and impedance measurements have been carried out during the sample diffusion by capillarity along the membrane. The impedance of the sensor changes because of the presence of magnetic nanoparticles. The results prove the potentiality of the method for point-of-care testing of biochemical substances and nanoparticle capillarity flow studies.

High-Throughput Printing Process for Flexible Electronics

NASA Astrophysics Data System (ADS)

Hyun, Woo Jin

Printed electronics is an emerging field for manufacturing electronic devices with low cost and minimal material waste for a variety of applications including displays, distributed sensing, smart packaging, and energy management. Moreover, its compatibility with roll-to-roll production formats and flexible substrates is desirable for continuous, high-throughput production of flexible electronics. Despite the promise, however, the roll-to-roll production of printed electronics is quite challenging due to web movement hindering accurate ink registration and high-fidelity printing. In this talk, I will present a promising strategy for roll-to-roll production using a novel printing process that we term SCALE (Self-aligned Capillarity-Assisted Lithography for Electronics). By utilizing capillarity of liquid inks on nano/micro-structured substrates, the SCALE process facilitates high-resolution and self-aligned patterning of electrically functional inks with greatly improved printing tolerance. I will show the fabrication of key building blocks (e.g. transistor, resistor, capacitor) for electronic circuits using the SCALE process on plastics.

Material limitations on the detection limit in refractometry.

PubMed

Skafte-Pedersen, Peder; Nunes, Pedro S; Xiao, Sanshui; Mortensen, Niels Asger

2009-01-01

We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

Discovering environmental cancer: Wilhelm Hueper, post-World War II epidemiology, and the vanishing clinician's eye.

PubMed Central

Sellers, C

1997-01-01

Today, our understanding of and approach to the exogenous causes of cancer are dominated by epidemiological practices that came into widespread use after World War II. This paper examines the forces, considerations, and controversies that shaped postwar risk factor epidemiology in the United States. It is argued that, for all of the new capabilities it brought, this risk factor epidemiology has left us with less of a clinical eye for unrecognized cancer hazards, especially from limited and localized exposures in the work-place. The focus here is on Wilhelm Hueper, author of the first textbook on occupational cancer (1942). Hueper became the foremost spokesman for earlier identification practices centering on occupational exposures. The new epidemiological methods and associated institutions that arose in the 1940s and 1950s bore an unsettled relation to earlier claims and methods that some, Hueper among them, interpreted as a challenge. Hueper's critique of the new epidemiology identified some of its limitations and potentially debilitating consequences that remain with us today. Images p1825-a p1827-a p1829-a PMID:9366640

Oliver Sacks: Our Correspondence About Twins/Twin Research: Vanishing Twins Syndrome; Discordant Sex in MZ Twins; Pregnancy Outcomes in IVF and ICSI Conceived Twins/Print and Media: Superfetated Twins; Twins Discordant for Smoking; Twins in Fashion; Yale University Twin Hockey Players; Conjoined Twin-Visiting Professor.

PubMed

Segal, Nancy L

2017-08-01

The late neurologist and author, Oliver Sacks, published an insightful 1986 review of Marjorie Wallace's book, The Silent Twins, in the New York Times. Taking exception to his assertion about Sir Francis Galton, I wrote a letter to the Times' editor. The letter was unpublished, but it brought a wonderful response from Sacks himself that is reproduced and examined. Next, brief reviews of twin research concerning the vanishing twin syndrome (VTS), discordant sex in a monozygotic (MZ) twin pair, and multiple pregnancy outcomes from assisted reproductive technology (ART) are presented. This section is followed by popular coverage of superfetated twins, smoking-discordant co-twins, twins in fashion, Yale University twin hockey players, and a visiting professor who was a conjoined twin.

Material Limitations on the Detection Limit in Refractometry

PubMed Central

Skafte-Pedersen, Peder; Nunes, Pedro S.; Xiao, Sanshui; Mortensen, Niels Asger

2009-01-01

We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly. PMID:22291513

Analysis of the Static Strength and Relative Endurance of Women Athletes

ERIC Educational Resources Information Center

Heyward, Vivian; McCreary, Leslie

1977-01-01

Investigations of static strength and relative endurance of the grip muscles of women athletes revealed that mean endurance time was significantly greater than for men. Results were discussed in light of evidence suggesting possible sex differences in muscle hypertrophy, capillarization of muscle tissue, critical occluding tension level, and…

(–)-Epicatechin enhances fatigue resistance and oxidative capacity in mouse muscle

PubMed Central

Nogueira, Leonardo; Ramirez-Sanchez, Israel; Perkins, Guy A; Murphy, Anne; Taub, Pam R; Ceballos, Guillermo; Villarreal, Francisco J; Hogan, Michael C; Malek, Moh H

2011-01-01

Abstract The flavanol (–)-epicatechin, a component of cacao (cocoa), has been shown to have multiple health benefits in humans. Using 1-year-old male mice, we examined the effects of 15 days of (–)-epicatechin treatment and regular exercise on: (1) exercise performance, (2) muscle fatigue, (3) capillarity, and (4) mitochondrial biogenesis in mouse hindlimb and heart muscles. Twenty-five male mice (C57BL/6N) were randomized into four groups: (1) water, (2) water–exercise (W-Ex), (3) (–)-epicatechin ((–)-Epi), and (4) (–)-epicatechin–exercise ((–)-Epi-Ex). Animals received 1 mg kg−1 of (–)-epicatechin or water (vehicle) via oral gavage (twice daily). Exercise groups underwent 15 days of treadmill exercise. Significant increases in treadmill performance (∼50%) and enhanced in situ muscle fatigue resistance (∼30%) were observed with (–)-epicatechin. Components of oxidative phosphorylation complexes, mitofilin, porin, nNOS, p-nNOS, and Tfam as well as mitochondrial volume and cristae abundance were significantly higher with (–)-epicatechin treatment for hindlimb and cardiac muscles than exercise alone. In addition, there were significant increases in skeletal muscle capillarity. The combination of (–)-epicatechin and exercise resulted in further increases in oxidative phosphorylation-complex proteins, mitofilin, porin and capillarity than (–)-epicatechin alone. These findings indicate that (–)-epicatechin alone or in combination with exercise induces an integrated response that includes structural and metabolic changes in skeletal and cardiac muscles resulting in greater endurance capacity. These results, therefore, warrant the further evaluation of the underlying mechanism of action of (–)-epicatechin and its potential clinical application as an exercise mimetic. PMID:21788351

A System for Governmental Virtual Institutions Based on Ontologies and Interaction Protocols

ERIC Educational Resources Information Center

de Araujo, Claudia J. Abrao; da Silva, Flavio S. Correa

2012-01-01

The authors believe that the adoption of virtual worlds is suitable for electronic government applications as it can increase the capillarity of public services, facilitate the access to government services and provide citizens with a natural and immersive experience. They present a Government Virtual Institution Model (GVI) for the provision of…

The Wetting Behavior of Imidazolium-Containing, Room-Temperature Molten Salt.

DTIC Science & Technology

1984-08-28

America, Inc.), Celgard 2500 and 3501 polypropylene film (Celanese Corp.) with 45% porosity and 0.04-pm pore size, and reticulated vitreous carbon or...E. Matijevic, ed., Wiley-Interscience, New York, pp. 85-153 (1969). (9) A. M. Schwartz , "Capillarity: Theory and Practice," Ind. Eng. Chem., 61, 10

First- and second-order metal-insulator phase transitions and topological aspects of a Hubbard-Rashba system

NASA Astrophysics Data System (ADS)

Marcelino, Edgar

2017-05-01

This paper considers a model consisting of a kinetic term, Rashba spin-orbit coupling and short-range Coulomb interaction at zero temperature. The Coulomb interaction is decoupled by a mean-field approximation in the spin channel using field theory methods. The results feature a first-order phase transition for any finite value of the chemical potential and quantum criticality for vanishing chemical potential. The Hall conductivity is also computed using the Kubo formula in a mean-field effective Hamiltonian. In the limit of infinite mass the kinetic term vanishes and all the phase transitions are of second order; in this case the spontaneous symmetry-breaking mechanism adds a ferromagnetic metallic phase to the system and features a zero-temperature quantization of the Hall conductivity in the insulating one.

Logamediate Inflation in f(T) Teleparallel Gravity

NASA Astrophysics Data System (ADS)

Rezazadeh, Kazem; Abdolmaleki, Asrin; Karami, Kayoomars

2017-02-01

We study logamediate inflation in the context of f(T) teleparallel gravity. f(T)-gravity is a generalization of the teleparallel gravity which is formulated on the Weitzenbock spacetime, characterized by the vanishing curvature tensor (absolute parallelism) and the non-vanishing torsion tensor. We consider an f(T)-gravity model which is sourced by a canonical scalar field. Assuming a power-law f(T) function in the action, we investigate an inflationary universe with a logamediate scale factor. Our results show that, although logamediate inflation is completely ruled out by observational data in the standard inflationary scenario based on Einstein gravity, it can be compatible with the 68% confidence limit joint region of Planck 2015 TT,TE,EE+lowP data in the framework of f(T)-gravity.

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

Rezazadeh, Kazem; Karami, Kayoomars; Abdolmaleki, Asrin, E-mail: rezazadeh86@gmail.com

We study logamediate inflation in the context of f ( T ) teleparallel gravity. f ( T )-gravity is a generalization of the teleparallel gravity which is formulated on the Weitzenbock spacetime, characterized by the vanishing curvature tensor (absolute parallelism) and the non-vanishing torsion tensor. We consider an f ( T )-gravity model which is sourced by a canonical scalar field. Assuming a power-law f ( T ) function in the action, we investigate an inflationary universe with a logamediate scale factor. Our results show that, although logamediate inflation is completely ruled out by observational data in the standard inflationarymore » scenario based on Einstein gravity, it can be compatible with the 68% confidence limit joint region of Planck 2015 TT,TE,EE+lowP data in the framework of f ( T )-gravity.« less

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

Carone, Christopher D.; Erlich, Joshua; Vaman, Diana

A constraint of vanishing energy-momentum tensor is motivated by a variety of perspectives on quantum gravity. We demonstrate in a concrete example how this constraint leads to a metric-independent theory in which quantum gravity emerges as a nonperturbative artifact of regularization-scale physics. We analyze a scalar theory similar to the Dirac-Born-Infeld (DBI) theory with vanishing gauge fields, with the DBI Lagrangian modulated by a scalar potential. In the limit of a large number of scalars, we explicitly demonstrate the existence of a composite massless spin-2 graviton in the spectrum that couples to matter as in Einstein gravity. As a result,more » we comment on the cosmological constant problem and the generalization to theories with fermions and gauge fields.« less

Opening up to Native Speaker Norms: The Use of /?/ in the Speech of Canadian French Immersion Students

ERIC Educational Resources Information Center

Nadasdi, Terry; Vickerman, Alison

2017-01-01

Our study examines the extent to which French immersion students use lax /?/ in the same linguistic context as native speakers of Canadian French. Our results show that the lax variant is vanishingly rare in the speech of immersion students and is used by only a small minority of individuals. This is interpreted as a limitation of French immersion…

Thermodynamic limit for coherence-limited solar power conversion

NASA Astrophysics Data System (ADS)

Mashaal, Heylal; Gordon, Jeffrey M.

2014-09-01

The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

Electromagnetic fields with vanishing quantum corrections

NASA Astrophysics Data System (ADS)

Ortaggio, Marcello; Pravda, Vojtěch

2018-04-01

We show that a large class of null electromagnetic fields are immune to any modifications of Maxwell's equations in the form of arbitrary powers and derivatives of the field strength. These are thus exact solutions to virtually any generalized classical electrodynamics containing both non-linear terms and higher derivatives, including, e.g., non-linear electrodynamics as well as QED- and string-motivated effective theories. This result holds not only in a flat or (anti-)de Sitter background, but also in a larger subset of Kundt spacetimes, which allow for the presence of aligned gravitational waves and pure radiation.

Assessment Is Learning: The Preposition Vanishes

ERIC Educational Resources Information Center

Hayward, Louise

2015-01-01

Scotland, in common with many countries internationally, has been learning how to align ideas from research with policy and practice. This article considers what Scotland learned from large-scale evaluations of its Assessment is for Learning (AifL) programme and the extent to which this evidence was used to inform future learning within the…

Who Will Replace Those Vanishing Execs?

ERIC Educational Resources Information Center

Geber, Beverly

2000-01-01

Many top-level managers are retiring early. Programs to prepare their replacements have been scaled back. Many companies are offering phased retirement plans, redesigning jobs, and paying for spouses to go along on business trips to keep their managers a little longer. (JOW)

[The physical examination - a vanishing art?

PubMed

Tönnesmann, Ernst; Goltz, Diane; Lewalter, Thorsten; Welz, Armin

2016-10-01

This report describes the case of a 63-year-old female patient who presented with progressive dyspnea to a specialized internal medicine practice. Prior consultations with her primary care physician and a cardiologist followed by hospitalizations in an acute care hospital and in a specialist clinic for cardiology had not yielded a conclusive diagnosis. During the physical examination, significant bilateral lower extremity edema, as well as pronounced jugular venous distention was noted while in a seated position. This prompted further targeted diagnostic examination and testing and resulted in the final diagnosis of constrictive pericarditis of tuberculous origin.The establishment of the diagnosis is discussed in the context of increasingly technologized medical practice, where clinical skills and the significance of the patient history and physical examination are declining. In addition, we discuss the problem of less common diseases of the myo- and pericardium with primarily diastolic (constrictive or restrictive) dysfunction being overlooked in routine cardiological diagnostic procedures, with a focus on coronary heart disease, valve disorders and the impairment of systolic ventricular function ("ejection fraction"). © Georg Thieme Verlag KG Stuttgart · New York.

The rheology of three-phase suspensions at low bubble capillary number

PubMed Central

Truby, J. M.; Mueller, S. P.; Llewellin, E. W.; Mader, H. M.

2015-01-01

We develop a model for the rheology of a three-phase suspension of bubbles and particles in a Newtonian liquid undergoing steady flow. We adopt an ‘effective-medium’ approach in which the bubbly liquid is treated as a continuous medium which suspends the particles. The resulting three-phase model combines separate two-phase models for bubble suspension rheology and particle suspension rheology, which are taken from the literature. The model is validated against new experimental data for three-phase suspensions of bubbles and spherical particles, collected in the low bubble capillary number regime. Good agreement is found across the experimental range of particle volume fraction (0≤ϕp≲0.5) and bubble volume fraction (0≤ϕb≲0.3). Consistent with model predictions, experimental results demonstrate that adding bubbles to a dilute particle suspension at low capillarity increases its viscosity, while adding bubbles to a concentrated particle suspension decreases its viscosity. The model accounts for particle anisometry and is easily extended to account for variable capillarity, but has not been experimentally validated for these cases. PMID:25568617

Experimentally Manipulating Items Informs on the (Limited) Construct and Criterion Validity of the Humor Styles Questionnaire

PubMed Central

Ruch, Willibald; Heintz, Sonja

2017-01-01

How strongly does humor (i.e., the construct-relevant content) in the Humor Styles Questionnaire (HSQ; Martin et al., 2003) determine the responses to this measure (i.e., construct validity)? Also, how much does humor influence the relationships of the four HSQ scales, namely affiliative, self-enhancing, aggressive, and self-defeating, with personality traits and subjective well-being (i.e., criterion validity)? The present paper answers these two questions by experimentally manipulating the 32 items of the HSQ to only (or mostly) contain humor (i.e., construct-relevant content) or to substitute the humor content with non-humorous alternatives (i.e., only assessing construct-irrelevant context). Study 1 (N = 187) showed that the HSQ affiliative scale was mainly determined by humor, self-enhancing and aggressive were determined by both humor and non-humorous context, and self-defeating was primarily determined by the context. This suggests that humor is not the primary source of the variance in three of the HQS scales, thereby limiting their construct validity. Study 2 (N = 261) showed that the relationships of the HSQ scales to the Big Five personality traits and subjective well-being (positive affect, negative affect, and life satisfaction) were consistently reduced (personality) or vanished (subjective well-being) when the non-humorous contexts in the HSQ items were controlled for. For the HSQ self-defeating scale, the pattern of relationships to personality was also altered, supporting an positive rather than a negative view of the humor in this humor style. The present findings thus call for a reevaluation of the role that humor plays in the HSQ (construct validity) and in the relationships to personality and well-being (criterion validity). PMID:28473794

Advances in wave turbulence: rapidly rotating flows

NASA Astrophysics Data System (ADS)

Cambon, C.; Rubinstein, R.; Godeferd, F. S.

2004-07-01

At asymptotically high rotation rates, rotating turbulence can be described as a field of interacting dispersive waves by the general theory of weak wave turbulence. However, rotating turbulence has some complicating features, including the anisotropy of the wave dispersion relation and the vanishing of the wave frequency on a non-vanishing set of 'slow' modes. These features prevent straightforward application of existing theories and lead to some interesting properties, including the transfer of energy towards the slow modes. This transfer competes with, and might even replace, the transfer to small scales envisioned in standard turbulence theories. In this paper, anisotropic spectra for rotating turbulence are proposed based on weak turbulence theory; some evidence for their existence is given based on numerical calculations of the wave turbulence equations. Previous arguments based on the properties of resonant wave interactions suggest that the slow modes decouple from the others. Here, an extended wave turbulence theory with non-resonant interactions is proposed in which all modes are coupled; these interactions are possible only because of the anisotropy of the dispersion relation. Finally, the vanishing of the wave frequency on the slow modes implies that these modes cannot be described by weak turbulence theory. A more comprehensive approach to rotating turbulence is proposed to overcome this limitation.

Squashed, magnetized black holes in D = 5 minimal gauged supergravity

NASA Astrophysics Data System (ADS)

Blázquez-Salcedo, Jose Luis; Kunz, Jutta; Navarro-Lérida, Francisco; Radu, Eugen

2018-02-01

We construct a new class of black hole solutions in five-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant. These configurations are cohomogeneity-1, with two equal-magnitude angular momenta. In the generic case, they possess a non-vanishing magnetic potential at infinity with a boundary metric which is the product of time and a squashed three-dimensional sphere. Both extremal and non-extremal black holes are studied. The non-extremal black holes satisfying a certain relation between electric charge, angular momenta and magnitude of the magnetic potential at infinity do not trivialize in the limit of vanishing event horizon size, becoming particle-like (non-topological) solitonic configurations. Among the extremal black holes, we show the existence of a new one-parameter family of supersymmetric solutions, which bifurcate from a critical Gutowski-Reall configuration.

Irregular wave functions of a hydrogen atom in a uniform magnetic field

NASA Technical Reports Server (NTRS)

Wintgen, D.; Hoenig, A.

1989-01-01

The highly excited irregular wave functions of a hydrogen atom in a uniform magnetic field are investigated analytically, with wave function scarring by periodic orbits considered quantitatively. The results obtained confirm that the contributions of closed classical orbits to the spatial wave functions vanish in the semiclassical limit. Their disappearance, however, is slow. This discussion is illustrated by numerical examples.

Chunk Limits and Length Limits in Immediate Recall: A Reconciliation

PubMed Central

Chen, Zhijian; Cowan, Nelson

2008-01-01

Whereas some research on immediate recall of verbal lists has suggested that it is limited by the number of chunks that can be recalled (e.g., Tulving & Patkau, 1962; Cowan, Chen, & Rouder, 2004), other research has suggested that it is limited by the length of the material to be recalled (e.g., Baddeley, Thomson, & Buchanan, 1975). We investigated this question by teaching new paired associations between words to create two-word chunks. The results suggest that both chunk capacity limits and length limits come into play. For the free recall of 12-word lists, 6 pre-learned pairs could be recalled about as well as 6 pre-exposed singletons, suggesting a chunk limit. However, for the serially-ordered recall of 8-word lists, 4 pre-learned pairs could be recalled about as well as 8 pre-exposed singletons, suggesting a length limit. Other conditions yielded intermediate results suggesting that sometimes both limits may operate together. PMID:16393043

Abrasion-set limits on Himalayan gravel flux.

PubMed

Dingle, Elizabeth H; Attal, Mikaël; Sinclair, Hugh D

2017-04-26

Rivers sourced in the Himalayan mountain range carry some of the largest sediment loads on the planet, yet coarse gravel in these rivers vanishes within approximately 10-40 kilometres on entering the Ganga Plain (the part of the North Indian River Plain containing the Ganges River). Understanding the fate of gravel is important for forecasting the response of rivers to large influxes of sediment triggered by earthquakes or storms. Rapid increase in gravel flux and subsequent channel bed aggradation (that is, sediment deposition by a river) following the 1999 Chi-Chi and 2008 Wenchuan earthquakes reduced channel capacity and increased flood inundation. Here we present an analysis of fan geometry, sediment grain size and lithology in the Ganga Basin. We find that the gravel fluxes from rivers draining the central Himalayan mountains, with upstream catchment areas ranging from about 350 to 50,000 square kilometres, are comparable. Our results show that abrasion of gravel during fluvial transport can explain this observation; most of the gravel sourced more than 100 kilometres upstream is converted into sand by the time it reaches the Ganga Plain. These findings indicate that earthquake-induced sediment pulses sourced from the Greater Himalayas, such as that following the 2015 Gorkha earthquake, are unlikely to drive increased gravel aggradation at the mountain front. Instead, we suggest that the sediment influx should result in an elevated sand flux, leading to distinct patterns of aggradation and flood risk in the densely populated, low-relief Ganga Plain.

Exercise Ventilatory Limitation: The Role Of Expiratory Flow Limitation

PubMed Central

Babb, Tony G.

2012-01-01

Ventilatory limitation to exercise remains an important unresolved clinical issue; as a result, many individuals misinterpret the effects of expiratory flow limitation as an all-or-nothing phenomenon. Expiratory flow limitation is not all-or-none; approaching maximal expiratory flow can have important effects not only on ventilatory capacity but also on breathing mechanics, ventilatory control, and possibly exertional dyspnea and exercise intolerance. PMID:23038244

Translation-aware semantic segmentation via conditional least-square generative adversarial networks

NASA Astrophysics Data System (ADS)

Zhang, Mi; Hu, Xiangyun; Zhao, Like; Pang, Shiyan; Gong, Jinqi; Luo, Min

2017-10-01

Semantic segmentation has recently made rapid progress in the field of remote sensing and computer vision. However, many leading approaches cannot simultaneously translate label maps to possible source images with a limited number of training images. The core issue is insufficient adversarial information to interpret the inverse process and proper objective loss function to overcome the vanishing gradient problem. We propose the use of conditional least squares generative adversarial networks (CLS-GAN) to delineate visual objects and solve these problems. We trained the CLS-GAN network for semantic segmentation to discriminate dense prediction information either from training images or generative networks. We show that the optimal objective function of CLS-GAN is a special class of f-divergence and yields a generator that lies on the decision boundary of discriminator that reduces possible vanished gradient. We also demonstrate the effectiveness of the proposed architecture at translating images from label maps in the learning process. Experiments on a limited number of high resolution images, including close-range and remote sensing datasets, indicate that the proposed method leads to the improved semantic segmentation accuracy and can simultaneously generate high quality images from label maps.

Properties of the Residual Stress of the Temporally Filtered Navier-Stokes Equations

NASA Technical Reports Server (NTRS)

Pruett, C. D.; Gatski, T. B.; Grosch, C. E.; Thacker, W. D.

2002-01-01

The development of a unifying framework among direct numerical simulations, large-eddy simulations, and statistically averaged formulations of the Navier-Stokes equations, is of current interest. Toward that goal, the properties of the residual (subgrid-scale) stress of the temporally filtered Navier-Stokes equations are carefully examined. Causal time-domain filters, parameterized by a temporal filter width 0 less than Delta less than infinity, are considered. For several reasons, the differential forms of such filters are preferred to their corresponding integral forms; among these, storage requirements for differential forms are typically much less than for integral forms and, for some filters, are independent of Delta. The behavior of the residual stress in the limits of both vanishing and in infinite filter widths is examined. It is shown analytically that, in the limit Delta to 0, the residual stress vanishes, in which case the Navier-Stokes equations are recovered from the temporally filtered equations. Alternately, in the limit Delta to infinity, the residual stress is equivalent to the long-time averaged stress, and the Reynolds-averaged Navier-Stokes equations are recovered from the temporally filtered equations. The predicted behavior at the asymptotic limits of filter width is further validated by numerical simulations of the temporally filtered forced, viscous Burger's equation. Finally, finite filter widths are also considered, and a priori analyses of temporal similarity and temporal approximate deconvolution models of the residual stress are conducted.

Predicting capillarity of mudrocks for geological storage of CO2

NASA Astrophysics Data System (ADS)

Busch, Andreas; Amann-Hildenbrand, Alexandra

2013-04-01

Various rock types were investigated, with the main focus on the determination and prediction of the capillary breakthrough and snap-off pressure in mudrocks (e.g. shales, siltstones, mudstones). Knowledge about these two critical pressures is important for the prediction of the capillary sealing capacity of CO2 storage sites. Capillary pressure experiments, when performed on low-permeable core plugs, are difficult and time consuming. Laboratory measurements on core plugs under in-situ conditions are mostly performed using nitrogen, but also with methane and carbon dioxide. Therefore, mercury porosimetry measurements (MIP) are preferably used in the industry to determine an equivalent value for the capillary breakthrough pressure. These measurements have the advantage to be quick and cheap and only require cuttings or trim samples. When evaluating the database in detail we find that (1) MIP data plot well with the drainage breakthrough pressures determined on sample plugs, while the conversion of the system Hg/air to CO2/brine using interfacial and wettability data does not provide a uniform match, potentially caused by non fully water-wet conditions; (2) brine permeability versus capillary breakthrough pressure determined on sample plugs shows a good match and could provide a first estimate of Pc-values since permeability is easier to determine than capillary breakthrough pressures. For imbibition snap-off pressures a good correlation was found for CH4 measured on sample plugs only; (3) porosity shows a fairly good correlation with permeability for sandstone only, and with plug-derived capillary breakthrough pressures for sandstones, carbonates and evaporates. No such correlations exist for mudrocks; (4) air and brine-derived permeabilities show an excellent correlation and (5) from the data used we do not infer any direct correlations between specific surface area (SSA), mineralogy or organic carbon content with permeability or capillary pressure however were able to predict permeabilities using a more sophisticated model that relies on several of these parameters.

A reconfigurable liquid metal antenna driven by electrochemically controlled capillarity

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

Wang, M.; Adams, J. J., E-mail: jjadams2@ncsu.edu; Trlica, C.

2015-05-21

We describe a new electrochemical method for reversible, pump-free control of liquid eutectic gallium and indium (EGaIn) in a capillary. Electrochemical deposition (or removal) of a surface oxide on the EGaIn significantly lowers (or increases) its interfacial tension as a means to induce the liquid metal in (or out) of the capillary. A fabricated prototype demonstrates this method in a reconfigurable antenna application in which EGaIn forms the radiating element. By inducing a change in the physical length of the EGaIn, the operating frequency of the antenna tunes over a large bandwidth. This purely electrochemical mechanism uses low, DC voltagesmore » to tune the antenna continuously and reversibly between 0.66 GHz and 3.4 GHz resulting in a 5:1 tuning range. Gain and radiation pattern measurements agree with electromagnetic simulations of the device, and its measured radiation efficiency varies from 41% to 70% over its tuning range.« less

Spatial patterns of lacustrine fish assemblages in a catchment of the Mississippi Alluvial Valley

USGS Publications Warehouse

Andrews, Caroline S.; Miranda, Leandro E.; Goetz, Daniel B.; Kroger, Robert

2014-01-01

Off-channel floodplain lakes are among the first landscape elements to vanish as a consequence of agricultural development. These habitats tend to accumulate sediments at fast rates and are converted to agricultural land as soon as suitable drainage can be attained. Considering that off-channel lakes with limited connectivity contribute greatly to the heterogeneity of fish assemblages, such losses pose great concerns to conservation of biodiversity.

Long-term Recurrent Convolutional Networks for Visual Recognition and Description

DTIC Science & Technology

2014-11-17

deep???, are effective for tasks involving sequences, visual and otherwise. We develop a novel recurrent convolutional architecture suitable for large...models which are also recurrent, or “temporally deep”, are effective for tasks involving sequences, visual and otherwise. We develop a novel recurrent...limitation of simple RNN models which strictly integrate state information over time is known as the “vanishing gradient” effect : the ability to

Hydrodynamic equations for electrons in graphene obtained from the maximum entropy principle

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

Barletti, Luigi, E-mail: luigi.barletti@unifi.it

2014-08-15

The maximum entropy principle is applied to the formal derivation of isothermal, Euler-like equations for semiclassical fermions (electrons and holes) in graphene. After proving general mathematical properties of the equations so obtained, their asymptotic form corresponding to significant physical regimes is investigated. In particular, the diffusive regime, the Maxwell-Boltzmann regime (high temperature), the collimation regime and the degenerate gas limit (vanishing temperature) are considered.

Polaron in the dilute critical Bose condensate

NASA Astrophysics Data System (ADS)

Pastukhov, Volodymyr

2018-05-01

The properties of an impurity immersed in a dilute D-dimensional Bose gas at temperatures close to its second-order phase transition point are considered. Particularly by means of the 1/N-expansion, we calculate the leading-order polaron energy and the damping rate in the limit of vanishing boson–boson interaction. It is shown that the perturbative effective mass and the quasiparticle residue diverge logarithmically in the long-length limit, signalling the non-analytic behavior of the impurity spectrum and pole-free structure of the polaron Green’s function in the infrared region, respectively.

Continuations of the nonlinear Schrödinger equation beyond the singularity

NASA Astrophysics Data System (ADS)

Fibich, G.; Klein, M.

2011-07-01

We present four continuations of the critical nonlinear Schrödinger equation (NLS) beyond the singularity: (1) a sub-threshold power continuation, (2) a shrinking-hole continuation for ring-type solutions, (3) a vanishing nonlinear-damping continuation and (4) a complex Ginzburg-Landau (CGL) continuation. Using asymptotic analysis, we explicitly calculate the limiting solutions beyond the singularity. These calculations show that for generic initial data that lead to a loglog collapse, the sub-threshold power limit is a Bourgain-Wang solution, both before and after the singularity, and the vanishing nonlinear-damping and CGL limits are a loglog solution before the singularity, and have an infinite-velocity expanding core after the singularity. Our results suggest that all NLS continuations share the universal feature that after the singularity time Tc, the phase of the singular core is only determined up to multiplication by eiθ. As a result, interactions between post-collapse beams (filaments) become chaotic. We also show that when the continuation model leads to a point singularity and preserves the NLS invariance under the transformation t → -t and ψ → ψ*, the singular core of the weak solution is symmetric with respect to Tc. Therefore, the sub-threshold power and the shrinking-hole continuations are symmetric with respect to Tc, but continuations which are based on perturbations of the NLS equation are generically asymmetric.

Interval Graph Limits

PubMed Central

Diaconis, Persi; Holmes, Susan; Janson, Svante

2015-01-01

We work out a graph limit theory for dense interval graphs. The theory developed departs from the usual description of a graph limit as a symmetric function W (x, y) on the unit square, with x and y uniform on the interval (0, 1). Instead, we fix a W and change the underlying distribution of the coordinates x and y. We find choices such that our limits are continuous. Connections to random interval graphs are given, including some examples. We also show a continuity result for the chromatic number and clique number of interval graphs. Some results on uniqueness of the limit description are given for general graph limits. PMID:26405368

Rapid and Simple Capillary-Rise/Vanishing Interfacial Tension Method To Determine Crude Oil Minimum Miscibility Pressure: Pure and Mixed CO 2 , Methane, and Ethane

DOE PAGES

Hawthorne, Steven B.; Miller, David J.; Jin, Lu; ...

2016-07-20

We report here a simplification of the capillary-rise/vanishing interfacial tension (IFT) method to measure minimum miscibility pressure (MMP) based on only requiring knowledge of when the interfacial tension approaches zero. Simply measuring the height of the crude oil in a capillary at several pressures from ambient to near the MMP pressure and extrapolating the oil height versus pressure plot to zero oil height yields the MMP without the need of the additional instrumentation and labor required to perform actual IFT measurements. A total of 2−4 MMP values can be determined per day with only one experimental apparatus, and the methodmore » greatly reduces the initial cost and complexity of the required instrumentation. The use of three capillaries having different inner diameters allows for triplicate determinations of MMP from each experiment. Because the actual MMP pressure need not be reached during the experiment, MMP values that exceed the pressure ratings of the equipment can be reasonably estimated (e.g., MMPs using pure nitrogen). The method was used to determine the MMP pressure for crude oil samples from a conventional Muddy Formation reservoir in the Powder River Basin [American Petroleum Institute (API) gravity of 35.8°] and an unconventional Bakken Formation reservoir in the Williston Basin (API gravity of 38.7°). The method is reproducible [typically <4% relative standard deviation (RSD)], and the method gave good agreement for a “live” Bakken oil with the results from a slim tube test of a commercial laboratory. Approximately 80 MMP values were measured using pure CO2, methane, and ethane as well as 0−100% mole ratios of methane/CO2 and methane/ethane. For both oil samples, ethane MMPs were ca. one-half those with CO2, while methane MMPs were ca. double or triple those with CO2. MMPs with mixed methane/CO2 showed a linear increase with mole percent methane for both crude oils, while both oils showed an exponential increase in MMP with

Rapid and Simple Capillary-Rise/Vanishing Interfacial Tension Method To Determine Crude Oil Minimum Miscibility Pressure: Pure and Mixed CO 2, Methane, and Ethane

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

Hawthorne, Steven B.; Miller, David J.; Jin, Lu

Here, we report a simplification of the capillary-rise/vanishing interfacial tension (IFT) method to measure minimum miscibility pressure (MMP) based on only requiring knowledge of when the interfacial tension approaches zero. Simply measuring the height of the crude oil in a capillary at several pressures from ambient to near the MMP pressure and extrapolating the oil height versus pressure plot to zero oil height yields the MMP without the need of the additional instrumentation and labor required to perform actual IFT measurements. A total of 2-4 MMP values can be determined per day with only one experimental apparatus, and the methodmore » greatly reduces the initial cost and complexity of the required instrumentation. The use of three capillaries having different inner diameters allows for triplicate determinations of MMP from each experiment. Because the actual MMP pressure need not be reached during the experiment, MMP values that exceed the pressure ratings of the equipment can be reasonably estimated (e.g., MMPs using pure nitrogen). The method was used to determine the MMP pressure for crude oil samples from a conventional Muddy Formation reservoir in the Powder River Basin [American Petroleum Institute (API) gravity of 35.8°] and an unconventional Bakken Formation reservoir in the Williston Basin (API gravity of 38.7°). The method is reproducible [typically <4% relative standard deviation (RSD)], and the method gave good agreement for a “live” Bakken oil with the results from a slim tube test of a commercial laboratory. Approximately 80 MMP values were measured using pure CO 2, methane, and ethane as well as 0-100% mole ratios of methane/CO 2 and methane/ethane. For both oil samples, ethane MMPs were ca. one-half those with CO 2, while methane MMPs were ca. double or triple those with CO 2. MMPs with mixed methane/CO 2 showed a linear increase with mole percent methane for both crude oils, while both oils showed an exponential increase in MMP with

Rapid and Simple Capillary-Rise/Vanishing Interfacial Tension Method To Determine Crude Oil Minimum Miscibility Pressure: Pure and Mixed CO 2, Methane, and Ethane

DOE PAGES

Hawthorne, Steven B.; Miller, David J.; Jin, Lu; ...

2016-07-10

Here, we report a simplification of the capillary-rise/vanishing interfacial tension (IFT) method to measure minimum miscibility pressure (MMP) based on only requiring knowledge of when the interfacial tension approaches zero. Simply measuring the height of the crude oil in a capillary at several pressures from ambient to near the MMP pressure and extrapolating the oil height versus pressure plot to zero oil height yields the MMP without the need of the additional instrumentation and labor required to perform actual IFT measurements. A total of 2-4 MMP values can be determined per day with only one experimental apparatus, and the methodmore » greatly reduces the initial cost and complexity of the required instrumentation. The use of three capillaries having different inner diameters allows for triplicate determinations of MMP from each experiment. Because the actual MMP pressure need not be reached during the experiment, MMP values that exceed the pressure ratings of the equipment can be reasonably estimated (e.g., MMPs using pure nitrogen). The method was used to determine the MMP pressure for crude oil samples from a conventional Muddy Formation reservoir in the Powder River Basin [American Petroleum Institute (API) gravity of 35.8°] and an unconventional Bakken Formation reservoir in the Williston Basin (API gravity of 38.7°). The method is reproducible [typically <4% relative standard deviation (RSD)], and the method gave good agreement for a “live” Bakken oil with the results from a slim tube test of a commercial laboratory. Approximately 80 MMP values were measured using pure CO 2, methane, and ethane as well as 0-100% mole ratios of methane/CO 2 and methane/ethane. For both oil samples, ethane MMPs were ca. one-half those with CO 2, while methane MMPs were ca. double or triple those with CO 2. MMPs with mixed methane/CO 2 showed a linear increase with mole percent methane for both crude oils, while both oils showed an exponential increase in MMP with

Electrostatic control of the coffee stain effect

NASA Astrophysics Data System (ADS)

Wray, Alex; Papageorgiou, Demetrios; Sefiane, Khellil; Matar, Omar

2013-11-01

The ``coffee stain effect,'' as first explained by Deegan et al. 1997, has received a great deal of attention amongst modellers and experimentalists in recent years, perhaps due in part to its obvious casual familiarity. However, it maintains interest because of its intriguing reliance on an interplay of a trio of effects: contact line pinning, inhomogeneous mass flux, and resulting capillarity-driven flow. What is more, the effect, and especially its suppression or reversal, find applications in fields as diverse as sample recovery, mass spectroscopy and the printing of Organic LEDs. We examine the motion a nanoparticle-laden droplet deposited on a precursor film, incorporating the effects of capillarity, concentration-dependent rheology, together with a heated substrate and resultant mass flux and Marangoni effects. We allow the substrate to act as an electrode and incorporate a second electrode above the droplet. The potential difference together with a disparity in electrical properties between the two regions results in electrical (Maxwell) stresses at the interface. We show via lubrication theory and via direct numerical simulations that the ring effect typically observed may be suppressed or augmented via appropriate use of electric fields. EPSRC DTG

Instability of the capillary bridge

NASA Astrophysics Data System (ADS)

Pare, Gounseti; Hoepffner, Jerome

2014-11-01

Capillary adhesion is a physical mechanism that maintains two bodies in contact by capillarity through a liquid ligament. The capillary bridge is an idealization of this capillary adhesion. In this study we first focus on the classical case of the stability of the capillary bridge. Secondly we study a slightly more complex configuration, imagining a flow in the capillary bridge as in the case of the dynamics of the neck of a liquid ligament, in its withdrawal under the effect of capillarity. Inspired by the experiments on soap films of Plateau, the configuration analyzed consists of an initially axisymmetric, mass of fluid held by surface tension forces between two parallel, coaxial, solid pipes of the same diameter. The results presented are obtained by numerical simulations using the free software, Gerris Flow Solver. We first focus on the capillary Venturi. In the static configuration the stability diagram of the capillary bridge obtained is in perfect agreement with the results of Lev A. Slobozhanin. In the dynamic case we develop a matlab code based on the one dimensional equations of Eggers and Dupont. The comparison of the bifurcation diagram obtained and the numerical simulations shows a good agreement.

Absence of ballistic charge transport in the half-filled 1D Hubbard model

NASA Astrophysics Data System (ADS)

Carmelo, J. M. P.; Nemati, S.; Prosen, T.

2018-05-01

Whether in the thermodynamic limit of lattice length L → ∞, hole concentration mηz = - 2 Sηz/L = 1 -ne → 0, nonzero temperature T > 0, and U / t > 0 the charge stiffness of the 1D Hubbard model with first neighbor transfer integral t and on-site repulsion U is finite or vanishes and thus whether there is or there is no ballistic charge transport, respectively, remains an unsolved and controversial issue, as different approaches yield contradictory results. (Here Sηz = - (L -Ne) / 2 is the η-spin projection and ne =Ne / L the electronic density.) In this paper we provide an upper bound on the charge stiffness and show that (similarly as at zero temperature), for T > 0 and U / t > 0 it vanishes for mηz → 0 within the canonical ensemble in the thermodynamic limit L → ∞. Moreover, we show that at high temperature T → ∞ the charge stiffness vanishes as well within the grand-canonical ensemble for L → ∞ and chemical potential μ →μu where (μ -μu) ≥ 0 and 2μu is the Mott-Hubbard gap. The lack of charge ballistic transport indicates that charge transport at finite temperatures is dominated by a diffusive contribution. Our scheme uses a suitable exact representation of the electrons in terms of rotated electrons for which the numbers of singly occupied and doubly occupied lattice sites are good quantum numbers for U / t > 0. In contrast to often less controllable numerical studies, the use of such a representation reveals the carriers that couple to the charge probes and provides useful physical information on the microscopic processes behind the exotic charge transport properties of the 1D electronic correlated system under study.

Zero-point angular momentum of supersymmetric Penning trap

NASA Astrophysics Data System (ADS)

Zhang, Jian-zu; Xu, Qiang

2000-10-01

The quantum behavior of supersymmetric Penning trap, specially the superpartner of its angular momentum, is investigated in the formulation of multi-dimensional semiunitary transformation of supersymmetric quantum mechanics. In the limit case of vanishing kinetic energy it is found that its lowest angular momentum is 3ℏ/2, which provides a possibility of directly checking the idea of supersymmetric quantum mechanics and thus suggests a possible experimental verification about this prediction.

The light bound states of N=1 supersymmetric SU(3) Yang-Mills theory on the lattice

NASA Astrophysics Data System (ADS)

Ali, Sajid; Bergner, Georg; Gerber, Henning; Giudice, Pietro; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp

2018-03-01

In this article we summarise our results from numerical simulations of N=1 supersymmetric Yang-Mills theory with gauge group SU(3). We use the formulation of Curci and Veneziano with clover-improved Wilson fermions. The masses of various bound states have been obtained at different values of the gluino mass and gauge coupling. Extrapolations to the limit of vanishing gluino mass indicate that the bound states form mass-degenerate supermultiplets.

On the assumption of vanishing temperature fluctuations at the wall for heat transfer modeling

NASA Technical Reports Server (NTRS)

Sommer, T. P.; So, R. M. C.; Zhang, H. S.

1993-01-01

Boundary conditions for fluctuating wall temperature are required for near-wall heat transfer modeling. However, their correct specifications for arbitrary thermal boundary conditions are not clear. The conventional approach is to assume zero fluctuating wall temperature or zero gradient for the temperature variance at the wall. These are idealized specifications and the latter condition could lead to an ill posed problem for fully-developed pipe and channel flows. In this paper, the validity and extent of the zero fluctuating wall temperature condition for heat transfer calculations is examined. The approach taken is to assume a Taylor expansion in the wall normal coordinate for the fluctuating temperature that is general enough to account for both zero and non-zero value at the wall. Turbulent conductivity is calculated from the temperature variance and its dissipation rate. Heat transfer calculations assuming both zero and non-zero fluctuating wall temperature reveal that the zero fluctuating wall temperature assumption is in general valid. The effects of non-zero fluctuating wall temperature are limited only to a very small region near the wall.

Shape dependent phoretic propulsion of slender active particles

NASA Astrophysics Data System (ADS)

Ibrahim, Y.; Golestanian, R.; Liverpool, T. B.

2018-03-01

We theoretically study the self-propulsion of a thin (slender) colloid driven by asymmetric chemical reactions on its surface at vanishing Reynolds number. Using the method of matched asymptotic expansions, we obtain the colloid self-propulsion velocity as a function of its shape and surface physicochemical properties. The mechanics of self-phoresis for rod-like swimmers has a richer spectrum of behaviors than spherical swimmers due to the presence of two small length scales, the slenderness of the rod and the width of the slip layer. This leads to subtleties in taking the limit of vanishing slenderness. As a result, even for very thin rods, the distribution of curvature along the surface of the swimmer, namely, its shape, plays a surprising role in determining the efficiency of propulsion. We find that thin cylindrical self-phoretic swimmers with blunt ends move faster than thin prolate spheroid shaped swimmers with the same aspect ratio.

PEAK LIMITING AMPLIFIER

DOEpatents

Goldsworthy, W.W.; Robinson, J.B.

1959-03-31

A peak voltage amplitude limiting system adapted for use with a cascade type amplifier is described. In its detailed aspects, the invention includes an amplifier having at least a first triode tube and a second triode tube, the cathode of the second tube being connected to the anode of the first tube. A peak limiter triode tube has its control grid coupled to thc anode of the second tube and its anode connected to the cathode of the second tube. The operation of the limiter is controlled by a bias voltage source connected to the control grid of the limiter tube and the output of the system is taken from the anode of the second tube.

Universities Seek Answers after Huge Sums Vanish

ERIC Educational Resources Information Center

Fain, Paul

2009-01-01

On February 13, administrators at the University of Pittsburgh and Carnegie Mellon University began to worry that $114-million they had invested with two Wall Street veterans might have disappeared. Their worst fears were realized two weeks later, as federal agents arrested Paul R. Greenwood and Stephen Walsh on multiple counts of fraud and…

Vanishing large ovarian cyst with thyroxine therapy.

PubMed

Dharmshaktu, Pramila; Kutiyal, Aditya; Dhanwal, Dinesh

2013-01-01

A 21-year-old female patient recently diagnosed with severe hypothyroidism was found to have a large ovarian cyst. In view of the large ovarian cyst, she was advised to undergo elective laparotomy in the gynaecology department. She was further evaluated in our medical out-patient department (OPD), and elective surgery was withheld. She was started on thyroxine replacement therapy, and within a period of 4 months, the size of the cyst regressed significantly, thereby improving the condition of the patient significantly. This case report highlights the rare and often missed association between hypothyroidism and ovarian cysts. Although very rare, profound hypothyroidism that can cause ovarian cysts in an adult should always be kept in the differential diagnosis to avoid unnecessary ovarian surgery. Hypothyroidism should be considered in the differential diagnosis of adult females presenting with multicystic ovarian tumours.Adequate thyroid hormone replacement therapy can prevent these patients from undergoing unnecessary and catastrophic ovarian resection.Surgical excision should be considered only when adequate thyroid replacement therapy fails to resolve ovarian enlargement.In younger women with ovarian cysts, it is also desirable to avoid unnecessary surgery so as to not compromise fertility in the future.

Vanishing large ovarian cyst with thyroxine therapy

PubMed Central

Dharmshaktu, Pramila; Kutiyal, Aditya; Dhanwal, Dinesh

2013-01-01

Summary A 21-year-old female patient recently diagnosed with severe hypothyroidism was found to have a large ovarian cyst. In view of the large ovarian cyst, she was advised to undergo elective laparotomy in the gynaecology department. She was further evaluated in our medical out-patient department (OPD), and elective surgery was withheld. She was started on thyroxine replacement therapy, and within a period of 4 months, the size of the cyst regressed significantly, thereby improving the condition of the patient significantly. This case report highlights the rare and often missed association between hypothyroidism and ovarian cysts. Although very rare, profound hypothyroidism that can cause ovarian cysts in an adult should always be kept in the differential diagnosis to avoid unnecessary ovarian surgery. Learning points Hypothyroidism should be considered in the differential diagnosis of adult females presenting with multicystic ovarian tumours.Adequate thyroid hormone replacement therapy can prevent these patients from undergoing unnecessary and catastrophic ovarian resection.Surgical excision should be considered only when adequate thyroid replacement therapy fails to resolve ovarian enlargement.In younger women with ovarian cysts, it is also desirable to avoid unnecessary surgery so as to not compromise fertility in the future. PMID:24683475

On singular cases in the design derivative of Green's functional

NASA Technical Reports Server (NTRS)

Reiss, Robert

1987-01-01

The author's prior development of a general abstract representation for the design sensitivities of Green's functional for linear structural systems is extended to the case where the structural stiffness vanishes at an internal location. This situation often occurs in the optimal design of structures. Most optimality criteria require that optimally designed beams be statically determinate. For clamped-pinned beams, for example, this is possible only if the flexural stiffness vanishes at some intermediate location. The Green's function for such structures depends upon the stiffness and the location where it vanishes. A precise representation for Green's function's sensitivity to the location of vanishing stiffness is presented for beams and axisymmetric plates.

Microwave spectroscopy evidence of superconducting pairing in the magnetic-field-induced metallic state of InO(x) films at zero temperature.

PubMed

Liu, Wei; Pan, LiDong; Wen, Jiajia; Kim, Minsoo; Sambandamurthy, G; Armitage, N P

2013-08-09

We investigate the field-tuned quantum phase transition in a 2D low-disorder amorphous InO(x) film in the frequency range of 0.05 to 16 GHz employing microwave spectroscopy. In the zero-temperature limit, the ac data are consistent with a scenario where this transition is from a superconductor to a metal instead of a direct transition to an insulator. The intervening metallic phase is unusual with a small but finite resistance that is much smaller than the normal state sheet resistance at the lowest measured temperatures. Moreover, it exhibits a superconducting response on short length and time scales while global superconductivity is destroyed. We present evidence that the true quantum critical point of this 2D superconductor metal transition is located at a field B(sm) far below the conventionally defined critical field B(cross) where different isotherms of magnetoresistance cross each other. The superfluid stiffness in the low-frequency limit and the superconducting fluctuation frequency from opposite sides of the transition both vanish at B≈B(sm). The lack of evidence for finite-frequency superfluid stiffness surviving B(cross) signifies that B(cross) is a crossover above which superconducting fluctuations make a vanishing contribution to dc and ac measurements.

A response to: Limitations within "The Limits to Tree Height".

PubMed

Koch, George W; Sillett, Stephen C

2009-02-01

Here we respond to the communication in American Journal of Botany (96: 542-544 in this issue) by Netting, who proposes several ways in which our paper "The Limits to Tree Height" (Nature 428: 851-854) may have erred in estimating the biophysical limits to height growth in Sequoia sempervirens. We first explain that because embolism repair requires long time periods and is generally incomplete, xylem vulnerability characteristics offer a sound basis for estimating performance limits in woody plants. We reaffirm our earlier use of vertical gradients of foliar carbon isotope composition with new data for S. sempervirens. We support these arguments with reference to studies in other tree species. We take exception with Netting's view that the turgor pressure-cell expansion relationship for Zea mays is applicable to S. sempervirens. Finally, we second Netting's call for more work on carbon allocation vis a vis height growth limits.

Dose limits for astronauts

NASA Technical Reports Server (NTRS)

Sinclair, W. K.

2000-01-01

Radiation exposures to individuals in space can greatly exceed natural radiation exposure on Earth and possibly normal occupational radiation exposures as well. Consequently, procedures limiting exposures would be necessary. Limitations were proposed by the Radiobiological Advisory Panel of the National Academy of Sciences/National Research Council in 1970. This panel recommended short-term limits to avoid deterministic effects and a single career limit (of 4 Sv) based on a doubling of the cancer risk in men aged 35 to 55. Later, when risk estimates for cancer had increased and were recognized to be age and sex dependent, the NCRP, in Report No. 98 in 1989, recommended a range of career limits based on age and sex from 1 to 4 Sv. NCRP is again in the process of revising recommendations for astronaut exposure, partly because risk estimates have increased further and partly to recognize trends in limiting radiation exposure occupationally on the ground. The result of these considerations is likely to be similar short-term limits for deterministic effects but modified career limits.

Finite-size Scaling of the Density of States in Photonic Band Gap Crystals

NASA Astrophysics Data System (ADS)

Hasan, Shakeeb Bin; Mosk, Allard P.; Vos, Willem L.; Lagendijk, Ad

2018-06-01

The famous vanishing of the density of states (DOS) in a band gap, be it photonic or electronic, pertains to the infinite-crystal limit. In contrast, all experiments and device applications refer to finite crystals, which raises the question: Upon increasing the linear size L of a crystal, how fast does the DOS approach the infinite-crystal limit? We present a theory for finite crystals that includes Bloch-mode broadening due to the presence of crystal boundaries. Our results demonstrate that the DOS for frequencies inside a band gap has a 1 /L scale dependence for crystals in one, two and three dimensions.

Statistical mechanics of free particles on space with Lie-type noncommutativity

NASA Astrophysics Data System (ADS)

Shariati, Ahmad; Khorrami, Mohammad; Fatollahi, Amir H.

2010-07-01

Effects of Lie-type noncommutativity on thermodynamic properties of a system of free identical particles are investigated. A definition for finite volume of the configuration space is given, and the grandcanonical partition function in the thermodynamic limit is calculated. Two possible definitions for the pressure are discussed, which are equivalent when the noncommutativity vanishes. The thermodynamic observables are extracted from the partition function. Different limits are discussed where either the noncommutativity or the quantum effects are important. Finally, specific cases are discussed where the group is SU(2) or SO(3), and the partition function of a nondegenerate gas is calculated.

Pore Scale Mechanistic Study of the Preferential Mode of Hydrate Formation in Sediments: Fluid Flow Aspects

NASA Astrophysics Data System (ADS)

Behseresht, J.; Prodanović, M.; Bryant, S. L.

2007-12-01

A spectrum of behavior is encountered in ocean sediments bearing methane hydrates, ranging from essentially static accumulations where hydrate and brine co-exist, to active cold seeps where hydrate and a methane gas phase co-exist in the hydrate stability zone (HSZ). In this and a companion paper (Jain and Juanes) we describe methods to test the following hypothesis: the coupling between drainage and fracturing, both induced by pore pressure, determines whether methane gas entering the HSZ is converted completely to hydrate. Here we describe a novel implementation of the level set method (LSM) to determine the capillarity-controlled displacement of brine by gas from sediment and from fractures within the sediment. Predictions of fluid configurations in infinite-acting model sediments indicate that the brine in drained sediment (after invasion by methane gas) is better connected than previously believed. This increases the availability of water and the rate of counter-diffusion of salinity ions, thus relaxing the limit on hydrate build-up within gas- invaded grain matrix. Simulated drainage of a fracture in sediment shows that points of contact between fracture faces are crucial. They allow residual water saturation to remain within an otherwise gas-filled fracture. Simulations of imbibition, which can occur for example after drainage into surrounding sediment reduces gas phase pressure in the fracture, indicate that the gas/water interfaces at contact points significantly shifts the threshold pressures for withdrawal of gas. During both drainage and imbibition, the contact points greatly increase water availability for hydrate formation within the fracture. We discuss coupling this capillarity-controlled displacement model with a discrete element model for grain-scale mechanics. The coupled model provides a basis for evaluating the macroscopic conditions (thickness of gas accumulation below the hydrate stability zone; average sediment grain size; principal earth

Agent-based models for latent liquidity and concave price impact

NASA Astrophysics Data System (ADS)

Mastromatteo, Iacopo; Tóth, Bence; Bouchaud, Jean-Philippe

2014-04-01

We revisit the "ɛ-intelligence" model of Tóth et al. [Phys. Rev. X 1, 021006 (2011), 10.1103/PhysRevX.1.021006], which was proposed as a minimal framework to understand the square-root dependence of the impact of meta-orders on volume in financial markets. The basic idea is that most of the daily liquidity is "latent" and furthermore vanishes linearly around the current price, as a consequence of the diffusion of the price itself. However, the numerical implementation of Tóth et al. (2011) was criticized as being unrealistic, in particular because all the "intelligence" was conferred to market orders, while limit orders were passive and random. In this work, we study various alternative specifications of the model, for example, allowing limit orders to react to the order flow or changing the execution protocols. By and large, our study lends strong support to the idea that the square-root impact law is a very generic and robust property that requires very few ingredients to be valid. We also show that the transition from superdiffusion to subdiffusion reported in Tóth et al. (2011) is in fact a crossover but that the original model can be slightly altered in order to give rise to a genuine phase transition, which is of interest on its own. We finally propose a general theoretical framework to understand how a nonlinear impact may appear even in the limit where the bias in the order flow is vanishingly small.

Agent-based models for latent liquidity and concave price impact.

PubMed

Mastromatteo, Iacopo; Tóth, Bence; Bouchaud, Jean-Philippe

2014-04-01

We revisit the "ɛ-intelligence" model of Tóth et al. [Phys. Rev. X 1, 021006 (2011)], which was proposed as a minimal framework to understand the square-root dependence of the impact of meta-orders on volume in financial markets. The basic idea is that most of the daily liquidity is "latent" and furthermore vanishes linearly around the current price, as a consequence of the diffusion of the price itself. However, the numerical implementation of Tóth et al. (2011) was criticized as being unrealistic, in particular because all the "intelligence" was conferred to market orders, while limit orders were passive and random. In this work, we study various alternative specifications of the model, for example, allowing limit orders to react to the order flow or changing the execution protocols. By and large, our study lends strong support to the idea that the square-root impact law is a very generic and robust property that requires very few ingredients to be valid. We also show that the transition from superdiffusion to subdiffusion reported in Tóth et al. (2011) is in fact a crossover but that the original model can be slightly altered in order to give rise to a genuine phase transition, which is of interest on its own. We finally propose a general theoretical framework to understand how a nonlinear impact may appear even in the limit where the bias in the order flow is vanishingly small.

Synchronization of Heterogeneous Oscillators by Noninvasive Time-Delayed Cross Coupling.

PubMed

Jüngling, Thomas; Fischer, Ingo; Schöll, Eckehard; Just, Wolfram

2015-11-06

We demonstrate that nonidentical systems, in particular, nonlinear oscillators with different time scales, can be synchronized if a mutual coupling via time-delayed control signals is implemented. Each oscillator settles on an unstable state, say a fixed point or an unstable periodic orbit, with a coupling force which vanishes in the long time limit. We present the underlying theoretical considerations and numerical simulations, and, moreover, demonstrate the concept experimentally in nonlinear electronic oscillators.

Goldstonic pseudoscalar mesons in Bethe-Salpeter-inspired setting

NASA Astrophysics Data System (ADS)

Lucha, Wolfgang; Schöberl, Franz F.

2018-03-01

For a two-particle bound-state equation closer to its Bethe-Salpeter origins than Salpeter’s equation, with effective interaction kernel deliberately forged such as to ensure, in the limit of zero mass of the bound-state constituents, the vanishing of the arising bound-state mass, we scrutinize the emerging features of the lightest pseudoscalar mesons for their agreement with the behavior predicted by a generalization of the Gell-Mann-Oakes-Renner relation.

High Risk Behaviors in Marine Mammals: Linking Behavioral Responses to Anthropogenic Disturbance to Biological Consequences

DTIC Science & Technology

2015-09-30

nitrogen) and metabolic byproducts ( lactic acid ) depends on heart rate, and the latter is correlated to stroke frequency in marine mammals, we are...for development of 3- D safety zones for diving marine mammals To promote the incorporation of data from these studies into US Navy environmental...capillarity), and cardiac risk factors that will be mapped on 3- D physical attributes (e.g., home range, hydrostatic pressure) of the marine

The microwave induced resistance response of a high mobility 2DEG from the quasi-classical limit to the quantum Hall regime

NASA Astrophysics Data System (ADS)

Studenikin, S. A.; Byszewski, M.; Maude, D. K.; Potemski, M.; Sachrajda, A.; Wasilewski, Z. R.; Hilke, M.; Pfeiffer, L. N.; West, K. W.

2006-08-01

Microwave induced resistance oscillations (MIROs) were studied experimentally over a very wide range of frequencies ranging from ∼20 GHz up to ∼4 THz, and from the quasi-classical regime to the quantum Hall effect regime. At low frequencies regular MIROs were observed, with a periodicity determined by the ratio of the microwave to cyclotron frequencies. For frequencies below 150 GHz the magnetic field dependence of MIROs waveform is well described by a simplified version of an existing theoretical model, where the damping is controlled by the width of the Landau levels. In the THz frequency range MIROs vanish and only pronounced resistance changes are observed at the cyclotron resonance. The evolution of MIROs with frequency is presented and discussed.

Designs of LiMIT as a Limiter in the EAST Tokamak

NASA Astrophysics Data System (ADS)

Szott, Matthew; Christenson, Michael; Kalathiparambil, Kishor; Ruzic, David

2016-10-01

Liquid metal plasma facing components (PFCs) provide a constantly refreshing, self-healing surface that can reduce erosion and thermal stress damage to prolong device lifetime, and additionally decrease edge recycling, reduce impurities, and enhance plasma performance. The Liquid Metal Infused Trench (LiMIT) system, developed at UIUC, has demonstrated thermoelectric magnetohydrodynamic (TEMHD) driven flow of liquid lithium through series of solid trenches. This TEMHD effect drives liquid lithium in fusion systems using the plasma heat flux and the toroidal magnetic field, and the surface tension of the liquid lithium maintains a fresh surface on top of the solid trenches. LiMIT has been successfully tested at UIUC as well as HT-7 and Magnum PSI at heat fluxes up to 3 MW/m2. The next step is demonstrating system viability in full-scale fusion-relevant conditions. In collaboration with a team in Hefei, design and testing has begun for a large scale LiMIT system that will act as a limiter in EAST. The designs improve upon previous versions of LiMIT tested at Illinois and incorporate lessons learned from earlier tests of liquid metal PFCs at EAST. Existing infrastructure is used to load and supply lithium to the system, and the LiMIT trenches will help maintain a smooth, fresh surface as well as aid in propelling the lithium out of direct plasma flux to improve heat transfer. Supported by DOE/ALPS DE-FG02-99ER54515.

CONTROL LIMITER DEVICE

DOEpatents

DeShong, J.A.

1960-03-01

A control-limiting device for monltoring a control system is described. The system comprises a conditionsensing device, a condition-varying device exerting a control over the condition, and a control means to actuate the condition-varying device. A control-limiting device integrates the total movement or other change of the condition-varying device over any interval of time during a continuum of overlapping periods of time, and if the tothl movement or change of the condition-varying device exceeds a preset value, the control- limiting device will switch the control of the operated apparatus from automatic to manual control.

Preliminary disposal limits, plume interaction factors, and final disposal limits

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

Flach, G.

In the 2008 E-Area Performance Assessment (PA), each final disposal limit was constructed as the product of a preliminary disposal limit and a plume interaction factor. The following mathematical development demonstrates that performance objectives are generally expected to be satisfied with high confidence under practical PA scenarios using this method. However, radionuclides that experience significant decay between a disposal unit and the 100-meter boundary, such as H-3 and Sr-90, can challenge performance objectives, depending on the disposed-of waste composition, facility geometry, and the significance of the plume interaction factor. Pros and cons of analyzing single disposal units or multiple disposalmore » units as a group in the preliminary disposal limits analysis are also identified.« less

Force Limited Vibration Testing

NASA Technical Reports Server (NTRS)

Scharton, Terry; Chang, Kurng Y.

2005-01-01

This slide presentation reviews the concept and applications of Force Limited Vibration Testing. The goal of vibration testing of aerospace hardware is to identify problems that would result in flight failures. The commonly used aerospace vibration tests uses artificially high shaker forces and responses at the resonance frequencies of the test item. It has become common to limit the acceleration responses in the test to those predicted for the flight. This requires an analysis of the acceleration response, and requires placing accelerometers on the test item. With the advent of piezoelectric gages it has become possible to improve vibration testing. The basic equations have are reviewed. Force limits are analogous and complementary to the acceleration specifications used in conventional vibration testing. Just as the acceleration specification is the frequency spectrum envelope of the in-flight acceleration at the interface between the test item and flight mounting structure, the force limit is the envelope of the in-flight force at the interface . In force limited vibration tests, both the acceleration and force specifications are needed, and the force specification is generally based on and proportional to the acceleration specification. Therefore, force limiting does not compensate for errors in the development of the acceleration specification, e.g., too much conservatism or the lack thereof. These errors will carry over into the force specification. Since in-flight vibratory force data are scarce, force limits are often derived from coupled system analyses and impedance information obtained from measurements or finite element models (FEM). Fortunately, data on the interface forces between systems and components are now available from system acoustic and vibration tests of development test models and from a few flight experiments. Semi-empirical methods of predicting force limits are currently being developed on the basis of the limited flight and system test

Advances and challenges in skeletal muscle angiogenesis

PubMed Central

Baum, Oliver; Hellsten, Ylva; Egginton, Stuart

2015-01-01

The role of capillaries is to serve as the interface for delivery of oxygen and removal of metabolites to/from tissues. During the past decade there has been a proliferation of studies that have advanced our understanding of angiogenesis, demonstrating that tissue capillary supply is under strict control during health but poorly controlled in disease, resulting in either excessive capillary growth (pathological angiogenesis) or losses in capillarity (rarefaction). Given that skeletal muscle comprises nearly 40% of body mass in humans, skeletal muscle capillary density has a significant impact on metabolism, endocrine function, and locomotion and is tightly regulated at many different levels. Skeletal muscle is also high adaptable and thus one of the few organ systems that can be experimentally manipulated (e.g., by exercise) to study physiological regulation of angiogenesis. This review will focus on the methodological concerns that have arisen in determining skeletal muscle capillarity and highlight the concepts that are reshaping our understanding of the angio-adaptation process. We also summarize selected new findings (physical influences, molecular changes, and ultrastructural rearrangement of capillaries) that identify areas of future research with the greatest potential to expand our understanding of how angiogenesis is normally regulated, and that may also help to better understand conditions of uncontrolled (pathological) angiogenesis. PMID:26608338

Global Well-Posedness and Decay Rates of Strong Solutions to a Non-Conservative Compressible Two-Fluid Model

NASA Astrophysics Data System (ADS)

Evje, Steinar; Wang, Wenjun; Wen, Huanyao

2016-09-01

In this paper, we consider a compressible two-fluid model with constant viscosity coefficients and unequal pressure functions {P^+neq P^-}. As mentioned in the seminal work by Bresch, Desjardins, et al. (Arch Rational Mech Anal 196:599-629, 2010) for the compressible two-fluid model, where {P^+=P^-} (common pressure) is used and capillarity effects are accounted for in terms of a third-order derivative of density, the case of constant viscosity coefficients cannot be handled in their settings. Besides, their analysis relies on a special choice for the density-dependent viscosity [refer also to another reference (Commun Math Phys 309:737-755, 2012) by Bresch, Huang and Li for a study of the same model in one dimension but without capillarity effects]. In this work, we obtain the global solution and its optimal decay rate (in time) with constant viscosity coefficients and some smallness assumptions. In particular, capillary pressure is taken into account in the sense that {Δ P=P^+ - P^-=fneq 0} where the difference function {f} is assumed to be a strictly decreasing function near the equilibrium relative to the fluid corresponding to {P^-}. This assumption plays an key role in the analysis and appears to have an essential stabilization effect on the model in question.

High-Intensity Strength Training Improves Function of Chronically Painful Muscles: Case-Control and RCT Studies

PubMed Central

Andersen, Christoffer H.; Skotte, Jørgen H.; Suetta, Charlotte; Søgaard, Karen; Saltin, Bengt; Sjøgaard, Gisela

2014-01-01

Aim. This study investigates consequences of chronic neck pain on muscle function and the rehabilitating effects of contrasting interventions. Methods. Women with trapezius myalgia (MYA, n = 42) and healthy controls (CON, n = 20) participated in a case-control study. Subsequently MYA were randomized to 10 weeks of specific strength training (SST, n = 18), general fitness training (GFT, n = 16), or a reference group without physical training (REF, n = 8). Participants performed tests of 100 consecutive cycles of 2 s isometric maximal voluntary contractions (MVC) of shoulder elevation followed by 2 s relaxation at baseline and 10-week follow-up. Results. In the case-control study, peak force, rate of force development, and rate of force relaxation as well as EMG amplitude were lower in MYA than CON throughout all 100 MVC. Muscle fiber capillarization was not significantly different between MYA and CON. In the intervention study, SST improved all force parameters significantly more than the two other groups, to levels comparable to that of CON. This was seen along with muscle fiber hypertrophy and increased capillarization. Conclusion. Women with trapezius myalgia have lower strength capacity during repetitive MVC of the trapezius muscle than healthy controls. High-intensity strength training effectively improves strength capacity during repetitive MVC of the painful trapezius muscle. PMID:24707475

Optical limiting materials

DOEpatents

McBranch, Duncan W.; Mattes, Benjamin R.; Koskelo, Aaron C.; Heeger, Alan J.; Robinson, Jeanne M.; Smilowitz, Laura B.; Klimov, Victor I.; Cha, Myoungsik; Sariciftci, N. Serdar; Hummelen, Jan C.

1998-01-01

Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

N-dark-dark solitons for the coupled higher-order nonlinear Schrödinger equations in optical fibers

NASA Astrophysics Data System (ADS)

Zhang, Hai-Qiang; Wang, Yue

2017-11-01

In this paper, we construct the binary Darboux transformation on the coupled higher-order dispersive nonlinear Schrödinger equations in optical fibers. We present the N-fold iterative transformation in terms of the determinants. By the limit technique, we derive the N-dark-dark soliton solutions from the non-vanishing background. Based on the obtained solutions, we find that the collision mechanisms of dark vector solitons exhibit the standard elastic collisions in both two components.

Initial-boundary layer associated with the nonlinear Darcy-Brinkman-Oberbeck-Boussinesq system

NASA Astrophysics Data System (ADS)

Fei, Mingwen; Han, Daozhi; Wang, Xiaoming

2017-01-01

In this paper, we study the vanishing Darcy number limit of the nonlinear Darcy-Brinkman-Oberbeck-Boussinesq system (DBOB). This singular perturbation problem involves singular structures both in time and in space giving rise to initial layers, boundary layers and initial-boundary layers. We construct an approximate solution to the DBOB system by the method of multiple scale expansions. The convergence with optimal convergence rates in certain Sobolev norms is established rigorously via the energy method.

Fast-dynamo action in unsteady flows and maps in three dimensions

NASA Technical Reports Server (NTRS)

Bayly, B. J.; Childress, S.

1987-01-01

Unsteady fast-dynamo action is obtained in a family of stretch-fold-shear maps applied to a spatially periodic magnetic field in three dimensions. Exponential growth of a mean field in the limit of vanishing diffusivity is demonstrated by a numerical method which alternates instantaneous deformations with molecular diffusion over a finite time interval. Analysis indicates that the dynamo is a coherent feature of the large scales, essentially independent of the cascade of structure to small scales.

Resurrecting Limited War Theory

DTIC Science & Technology

2008-05-01

indirectly with an appreciation of the principles and guidelines for limited war. 15. SUBJECT TERMS Limited War, Political Objectives, Total War...conflict between other nations may require the United States to act indirectly with an appreciation of the principles and guidelines for limited war...in war, echoing Clausewitz’s principle of political primacy. Like Clausewitz, he was also a student of

Academia vs Industry: vanishing boundaries between global earthquake seismology and exploration seismics.

NASA Astrophysics Data System (ADS)

van der Hilst, R. D.

2011-12-01

Global seismology and exploration seismics have long lived in parallel universes, with little cross-fertilization of methodologies and with interaction between the associated communities often limited to company recruitment of students. Fortunately, this traditional separation of technology and people has begun to disappear. This is driven not only by continuing demands for human and financial resources (for companies and academia, respectively) but increasingly also by overlapping intellectual interest. First, 'waves are waves' (that is, the fundamental physics - and math to describe/handle it - is scale invariant) and many artificial boundaries are being removed by use of better wave theory, faster computers, and new data acquisition paradigms. For example, the development of dense sensor arrays (in USA, Europe, Asia - mostly China and Japan) is increasing the attraction (and need) of industry-style interrogation of massive data sets. Examples include large scale seismic exploration of Earth's deep interior with inverse scattering of teleseismic wavefields (e.g., Van der Hilst et al., Science, 2007). On the other hand, reservoir exploration and production benefits from expertise in earthquake seismology, both for better characterization of reservoirs and their overburden and for (induced) micro-earthquake analysis. Passive source methods (including but not restricted to ambient noise tomography) are providing new, economic opportunities for velocity analysis and monitoring, and studies of (micro)seismicity (e.g., source location, parameters, and moment tensor) allow in situ stress determination, tomographic velocity analysis with natural sources in the reservoir, and 4D monitoring (e.g., for hydrocarbon production, carbon sequestration, enhanced geothermal systems, and unconventional gas production). Second, the gap between the frequency ranges traditionally considered by both communities is being bridged by better theory, new sensor technology, and through

Limits to Inclusion

ERIC Educational Resources Information Center

Hansen, Janne Hedegaard

2012-01-01

In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

Determination of the Limiting Magnitude

NASA Technical Reports Server (NTRS)

Kingery, Aaron; Blaauw, Rhiannon

2017-01-01

The limiting magnitude of an optical camera system is an important property to understand since it is used to find the completeness limit of observations. Limiting magnitude depends on the hardware and software of the system, current weather conditions, and the angular speed of the objects observed. If an object exhibits a substantial angular rate during the exposure, its light spreads out over more pixels than the stationary stars. This spreading causes the limiting magnitude to be brighter when compared to the stellar limiting magnitude. The effect, which begins to become important when the object moves a full width at half max during a single exposure or video frame. For targets with high angular speeds or camera systems with narrow field of view or long exposures, this correction can be significant, up to several magnitudes. The stars in an image are often used to measure the limiting magnitude since they are stationary, have known brightness, and are present in large numbers, making the determination of the limiting magnitude fairly simple. In order to transform stellar limiting magnitude to object limiting magnitude, a correction must be applied accounting for the angular velocity. This technique is adopted in meteor and other fast-moving object observations, as the lack of a statistically significant sample of targets makes it virtually impossible to determine the limiting magnitude before the weather conditions change. While the weather is the dominant factor in observing satellites, the limiting magnitude for meteors also changes throughout the night due to the motion of a meteor shower or sporadic source radiant across the sky. This paper presents methods for determining the limiting stellar magnitude and the conversion to the target limiting magnitude.

Interference and memory capacity limitations.

PubMed

Endress, Ansgar D; Szabó, Szilárd

2017-10-01

Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Wigner molecules: natural orbitals of strongly correlated two-electron harmonium.

PubMed

Cioslowski, Jerzy; Buchowiecki, Marcin

2006-08-14

Explicit asymptotic expressions for natural orbitals and their occupancies are derived for the harmonium atom at the strong-correlation limit at which the confinement strength omega tends to zero. Unlike in systems with moderate correlation effects, the occupancies at the omega-->0 limit (derived from occupation amplitudes with alternating sign patterns) are vanishingly small and asymptotically independent of the angular momentum, forming a geometric progression with the scale factor proportional to omega(1/3) and the common ratio of ca. 0.0186. The radial components of the natural orbitals are given by products of polynomials and Gaussian functions that, as expected, peak at approximately half of the equilibrium interelectron distance.

Dain’s invariant on non-time symmetric initial data sets

NASA Astrophysics Data System (ADS)

Valiente Kroon, J. A.; Williams, J. L.

2017-06-01

We extend Dain’s construction of a geometric invariant characterising static initial data sets for the vacuum Einstein field equations to situations with a non-vanishing extrinsic curvature. This invariant gives a measure of how much an initial data set with non-vanishing ADM 4-momentum deviates from stationarity. In particular, it vanishes if and only if the initial data set is stationary. Thus, the invariant provides a quantification of the amount of gravitational radiation contained in the initial data set.

Homogeneous nucleation in liquid nitrogen at negative pressures

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

Baidakov, V. G., E-mail: baidakov@itp.uran.ru; Vinogradov, V. E.; Pavlov, P. A.

2016-10-15

The kinetics of spontaneous cavitation in liquid nitrogen at positive and negative pressures has been studied in a tension wave formed by a compression pulse reflected from the liquid–vapor interface on a thin platinum wire heated by a current pulse. The limiting tensile stresses (Δp = p{sub s}–p, where p{sub s} is the saturation pressure), the corresponding bubble nucleation frequencies J (10{sup 20}–10{sup 22} s{sup –1} m{sup –3}), and temperature induced nucleation frequency growth rate G{sub T} = dlnJ/dT have been experimentally determined. At T = 90 K, the limiting tensile stress was Δp = 8.3 MPa, which was 4.9more » MPa lower than the value corresponding to the boundary of thermodynamic stability of the liquid phase (spinodal). The measurement results were compared to classical (homogeneous) nucleation theory (CNT) with and without neglect of the dependence of the surface tension of critical bubbles on their dimensions. In the latter case, the properties of new phase nuclei were described in terms of the Van der Waals theory of capillarity. The experimental data agree well with the CNT theory when it takes into account the “size effect.”.« less

Topological susceptibility with a single light quark flavour

NASA Astrophysics Data System (ADS)

Frison, Julien; Kitano, Ryuichiro; Yamada, Norikazu

2018-03-01

One of the historical suggestions to tackle the strong CP problem is to take the up quark mass to zero while keeping md finite. The θ angle is then supposed to become irrelevant, i.e. the topological susceptibility vanishes. However, the definition of the quark mass is scheme-dependent and identifying the mu = 0 point is not trivial, in particular with Wilson-like fermions. More specifically, up to our knowledge there is no theoretical argument guaranteeing that the topological susceptibility exactly vanishes when the PCAC mass does. We will present our recent progresses on the empirical check of this property using Nf = 1 + 2 flavours of clover fermions, where the lightest fermion is tuned very close to muPCAC= 0 and the mass of the other two is kept of the order of magnitude of the physical ms. This choice is indeed expected to amplify any unknown non-perturbative effect caused by mu ≠ md. The simulation is repeated for several βs and those results, although preliminary, give a hint about what happens in the continuum limit.

Flavours and infra-red instability in holography

NASA Astrophysics Data System (ADS)

Kundu, Arnab

2017-11-01

With a simple gravitational model in five dimensions, defined by Einstein-gravity with a negative cosmological constant, coupled to a Dirac-Born-Infeld and a Chern-Simons term, we explore the fate of BF-bound violation for a probe scalar field and a fluctuation mode of the corresponding geometry. We assume this simple model to capture the dynamics of a strongly coupled SU(N c ) gauge theory with N f fundamental matter, which in the limit O({N}_c)˜ O({N}_f) and with a non-vanishing matter density, is holographically described by an AdS2-geometry in the IR. We demonstrate that, superconductor/superfluid instabilities are facilitated and spontaneous breaking of translational invariance is inhibited with increasing values of ( N f /N c ). This is similar, in spirit, with known results in large N c Quantum Chromodynamics with N f quarks and a non-vanishing density, in which the chiral density wave phase becomes suppressed and superconducting instabilities become favoured as the number of quarks is increased.

Statistical Limits to Super Resolution

NASA Astrophysics Data System (ADS)

Lucy, L. B.

1992-08-01

The limits imposed by photon statistics on the degree to which Rayleigh's resolution limit for diffraction-limited images can be surpassed by applying image restoration techniques are investigated. An approximate statistical theory is given for the number of detected photons required in the image of an unresolved pair of equal point sources in order that its information content allows in principle resolution by restoration. This theory is confirmed by numerical restoration experiments on synthetic images, and quantitative limits are presented for restoration of diffraction-limited images formed by slit and circular apertures.

Updates on Force Limiting Improvements

NASA Technical Reports Server (NTRS)

Kolaini, Ali R.; Scharton, Terry

2013-01-01

The following conventional force limiting methods currently practiced in deriving force limiting specifications assume one-dimensional translation source and load apparent masses: Simple TDOF model; Semi-empirical force limits; Apparent mass, etc.; Impedance method. Uncorrelated motion of the mounting points for components mounted on panels and correlated, but out-of-phase, motions of the support structures are important and should be considered in deriving force limiting specifications. In this presentation "rock-n-roll" motions of the components supported by panels, which leads to a more realistic force limiting specifications are discussed.

Effect of Macroscopic Impurities on Resistive Measurements in Three Dimensions

NASA Astrophysics Data System (ADS)

Koon, Daniel W.

1997-03-01

The authors extend their study of the effect of macroscopic impurities on resistive measurements to include specimens of finite thickness. The effect of such impurities is calculated for a rectangular parallelepiped with two current and two voltage contacts on the corners of one of its faces. The weighting function(D. W. Koon and C. J. Knickerbocker, Rev. Sci. Instrum. 63, 207 (1992).) displays singularities near these contacts, but these are shown to vanish in the two-dimensional limit, in agreement with previous results.

On 3D minimal massive gravity

NASA Astrophysics Data System (ADS)

Alishahiha, Mohsen; Qaemmaqami, Mohammad M.; Naseh, Ali; Shirzad, Ahmad

2014-12-01

We study linearized equations of motion of the newly proposed three dimensional gravity, known as minimal massive gravity, using its metric formulation. By making use of a redefinition of the parameters of the model, we observe that the resulting linearized equations are exactly the same as that of TMG. In particular the model admits logarithmic modes at critical points. We also study several vacuum solutions of the model, specially at a certain limit where the contribution of Chern-Simons term vanishes.

Shape Descriptors for the Quantification of Microstructures

DTIC Science & Technology

2016-01-05

SUBJECT TERMS image analysis , microstructure 16.  SECURITY CLASSIFICATION OF: 17.  LIMITATION OF       ABSTRACT 18.  NUMBER        OF Standard Form...image entropy becomes nearly linearly dependent on temperature. The image analysis approach is capable of characterizing the range of strain domain...recognition and image analysis . The main hurdle to be overcome is the vanishing of these odd order moments for shapes which are symmetric about the

Quantum cybernetics: a new perspective for Nelson's stochastic theory, nonlocality, and the Klein-Gordon equation

NASA Astrophysics Data System (ADS)

Grössing, Gerhard

2002-04-01

The Klein-Gordon equation is shown to be equivalent to coupled partial differential equations for a sub-quantum Brownian movement of a “particle”, which is both passively affected by, and actively affecting, a diffusion process of its generally nonlocal environment. This indicates circularly causal, or “cybernetic”, relationships between “particles” and their surroundings. Moreover, in the relativistic domain, the original stochastic theory of Nelson is shown to hold as a limiting case only, i.e., for a vanishing quantum potential.

Evidence for Central Venous Pressure Resetting During Initial Exposure to Microgravity

DTIC Science & Technology

2001-12-01

to 10° HDT. During each experimental condition, water and food were provided ad libitum and intake amounts were recorded. A standard monkey diet ...biscuit (LabDiet) of ;3.5 g with a caloric density equal to 4 kcal/g (69% carbohy- drate, 13% fat, 18% protein) was used as the primary food source...effect of Dextran on water filtration from renal tubules to tubular capillar- ies, consequently reducing urine formation in a hypo - volemic state of HDT

Term limits and the tobacco industry.

PubMed

Apollonio, Dorie E; Glantz, Stanton A; Bero, Lisa A

2014-03-01

In the 1990s several American states passed term limits on legislators with the stated intention of reducing the influence of wealthy industries on career legislators. Although term limits in the United States do not have a direct relationship to public health, the tobacco industry anticipated that term limits could have indirect effects by either limiting or expanding industry influence. We detail the strategy of the tobacco industry in the wake of term limits using internal tobacco company documents and a database of campaign contributions made to legislators in term limited states between 1988 and 2002. Despite some expectations that term limits would limit tobacco industry access to state legislators, term limits appear to have had the opposite effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microbial limitation in a changing world: A stoichiometric approach for predicting microbial resource limitation and fluxes

NASA Astrophysics Data System (ADS)

Midgley, M.; Phillips, R.

2014-12-01

Microbes mediate fluxes of carbon (C), nitrogen (N), and phosphorus (P) in soils depending on ratios of available C, N, and P relative to microbial demand. Hence, characterizing microbial C and nutrient limitation in soils is critical for predicting how ecosystems will respond to human alterations of climate and nutrient availability. Here, we take a stoichiometric approach to assessing microbial C, N, and P limitation by using threshold element ratios (TERs). TERs enable shifting resource limitation to be assessed by matching C, N and P ratios from microbial biomass, extracellular enzyme activities, and soil nutrient concentrations. We assessed microbial nutrient limitation in temperate forests dominated by trees that associate with one of two mycorrhizal symbionts: arbsucular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. We found that both ECM and AM microbial communities were co-limited by C and N, supporting conventional wisdom that microbes are C-limited and temperate forests are N-limited. However, AM microbial communities were relatively more C-limited than ECM communities (P=0.001). In response to chronic field N fertilization, both AM and ECM communities became relatively more P-limited (P=0.011), but they remained N- and C-limited overall. Thus, realistic levels of N deposition may not dampen microbial N limitation. Reflecting differences in relative limitation, N mineralization rates were higher in AM soils than in ECM soils (P=0.004) while C mineralization rates were higher in ECM soils than in AM soils (P=0.023). There were no significant differences in P flux between AM and ECM soils or detectable mineralization responses to N addition, indicating that mineralization rates are closely tied to C and nutrient limitation. Overall, we found that 1) microbial resource limitation can be detected without resource addition; and 2) TERs and ratios of labile resources are viable tools for predicting mineralization responses to resource additions.

Why build limited access highways?.

DOT National Transportation Integrated Search

1991-01-01

This report first explains what a limited access highway is, then describes the benefits and advantages of limited access highways. As compared with highways with no control of access, limited access highways (especially those with full control) have...

26 CFR 1.1502-93 - Consolidated section 382 limitation (or subgroup section 382 limitation).

Code of Federal Regulations, 2011 CFR

2011-04-01

... section 382 limitation) for any post-change year is an amount equal to the value of the loss group (or... regulations thereunder. See, for example, section 382(b)(2) (relating to the carryforward of unused section 382 limitation), section 382(b)(3)(B) (relating to the section 382 limitation for the post-change year...

26 CFR 1.1502-93 - Consolidated section 382 limitation (or subgroup section 382 limitation).

Code of Federal Regulations, 2013 CFR

2013-04-01

... section 382 limitation) for any post-change year is an amount equal to the value of the loss group (or... regulations thereunder. See, for example, section 382(b)(2) (relating to the carryforward of unused section 382 limitation), section 382(b)(3)(B) (relating to the section 382 limitation for the post-change year...

26 CFR 1.1502-93 - Consolidated section 382 limitation (or subgroup section 382 limitation).

Code of Federal Regulations, 2012 CFR

2012-04-01

... section 382 limitation) for any post-change year is an amount equal to the value of the loss group (or... regulations thereunder. See, for example, section 382(b)(2) (relating to the carryforward of unused section 382 limitation), section 382(b)(3)(B) (relating to the section 382 limitation for the post-change year...

Estimating macroporosity in a forest watershed by use of a tension infiltrometer

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

Watson, K.W.; Luxmoore, R.J.

The ability to obtain sufficient field hydrologic data at reasonable cost can be an important limiting factor in applying transport models. A procedure is described for using ponded-flow- and tension-infiltration measurements to calculate transport parameters in a forest watershed. Thirty infiltration measurements were taken under ponded-flow conditions and at 3, 6, and 15 cm (H/sub 2/O) tension. It was assumed from capillarity theory that pores > 0.1-, 0.05-, and 0.02-cm diam, respectively, were excluded from the transport process during the tension infiltration measurements. Under ponded flow, 73% of the flux was conducted through macropores (i.e., pores > 0.1-cm diam.). Anmore » estimated 96% of the water flux was transmitted through only 0.32% of the soil volume. In general the larger the total water flux the larger the macropore contribution to total water flux. The Shapiro-Wilk normality test indicated that water flux through both matrix pore space and macropores was log-normally distributed in space.« less

A Second-Order Phase Transition as a Limit of the First-Order Phase Transitions —Coherent Anomalies and Critical Phenomena in the Potts Models—

NASA Astrophysics Data System (ADS)

Katori, Makoto

1988-12-01

A new scheme of the coherent-anomaly method (CAM) is proposed to study critical phenomena in the models for which a mean-field description gives spurious first-order phase transition. A canonical series of mean-field-type approximations are constructed so that the spurious discontinuity should vanish asymptotically as the approximate critical temperature approachs the true value. The true value of the critical exponents β and γ are related to the coherent-anomaly exponents defined among the classical approximations. The formulation is demonstrated in the two-dimensional q-state Potts models for q{=}3 and 4. The result shows that the present method enables us to estimate the critical exponents with high accuracy by using the date of the cluster-mean-field approximations.

Force Limit System

NASA Technical Reports Server (NTRS)

Pawlik, Ralph; Krause, David; Bremenour, Frank

2011-01-01

The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (non-electrical) device. When a test specimen is loaded via an electromechanical or hydraulic test system, a chance of an overload condition exists. An overload applied to a specimen could result in irreparable damage to the specimen and/or fixturing. The FLS restricts the maximum load that an actuator can apply to a test specimen. When testing limited-run test articles or using very expensive fixtures, the use of such a device is highly recommended. Test setups typically use electronic peak protection, which can be the source of overload due to malfunctioning components or the inability to react quickly enough to load spikes. The FLS works independently of the electronic overload protection.

Novel limiter pump topologies

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

Schultz, J.H.

1981-01-01

The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure.

Metrics, Business Plans, and the Vanishing Public Good

ERIC Educational Resources Information Center

Tuchman, Gaye

2011-01-01

For at least 30 years, professional work has been changing. Even such once-elite professionals as doctors, lawyers, and professors have become subject to significant control. Single-practitioner medical practices have given way to group practices subject to the rules of insurance plans; lawyers join mammoth firms where paralegals time the steps…

The Essence of Nonclassicality: Non-Vanishing Signal Deficit

NASA Astrophysics Data System (ADS)

Aravinda, S.; Srikanth, R.

2015-12-01

Nonclassical properties of correlations- like unpredictability, no-cloning and uncertainty- are known to follow from two assumptions: nonlocality and no-signaling. For two-input-two-output correlations, we derive these properties from a single, unified assumption: namely, the excess of the communication cost over the signaling in the correlation. This is relevant to quantum temporal correlations, resources to simulate quantum correlations and extensions of quantum mechanics. We generalize in the context of such correlations the nonclassicality result for nonlocal-nonsignaling correlations (Masanes et al., Phys. Rev. A 73, 012112 (2006)) and the uncertainty bound on nonlocality (Oppenheim and Wehner, Science 330(6007), 1072 (2010)), when the no-signaling condition is relaxed.

Genetics Home Reference: leukoencephalopathy with vanishing white matter

MedlinePlus

... The eIF2B protein helps regulate overall protein production (synthesis) in the cell by interacting with another protein, ... because it is involved in starting (initiating) protein synthesis. Proper regulation of protein synthesis is vital for ...

Washington, D.C.'s vanishing springs and waterways

USGS Publications Warehouse

Williams, Garnett P.

1977-01-01

This paper traces the disappearance or reduction of the many prominent springs and waterways that existed in Washington, D.C. , 200 years ago. The best known springs were the Smith Springs (now under the McMillan Reservoir), the Franklin Park Springs (13th and I Streets, NW.), Gibson 's Spring (15th and E Streets, NE.), Caffrey 's Spring (Ninth and F Streets, NW.), and the City Spring (C Street between Four and One-Half and Sixth Streets, NW.). Tiber Creek, flowing south to the Capitol and thence westward along Consititution Avenue, joined the Potomac River at 17th Street and Constitution Avenue. In the 1800's, the Constitution Avenue reach was made into a canal which was used by scows and steamboats up to about 1850. The canal was changed into a covered sewer in the 1870's, and the only remaining visible surface remnant is the lock-keeper 's little stone house at 17th and Constitution Avenue, NW. Because of sedimentation problems and reclamation projects, Rock Creek, the Potomac River , and the Anacostia River are considerably narrower and shallower today than they were in colonial times. For example, the mouth of Rock Creek at one time was a wide, busy ship harbor , which Georgetown used for an extensive foreign trade, and the Potomac River shore originally extended to 17th and Constitution Avenue, NW. (Woodard-USGS)

Vanishing Voices: The Extinction of the World's Languages.

ERIC Educational Resources Information Center

Nettle, Daniel; Romaine, Suzanne

This book holds that the evolution of the mind has given rise to great diversity of language and culture, each going along with a distinct adaptation to life specific ecosystems or geographical areas. Much like the wealth of plant and animal species is essential to biodiversity and ecological balance, diversity in the world's languages is vital to…

Social Learning Theory: A Vanishing or Expanding Presence?

ERIC Educational Resources Information Center

Stuart, Richard B.

1989-01-01

Reviews history and current status of social learning theory (SLT) including present conflict between "cognitive behaviorists" within the movement. Makes suggestions on how to resolve conflict in a way that will further secure the future role of SLT. Offers prescription for adoption of a multifaceted "indirect" approach to…

Detecting vanishing dimensions via primordial gravitational wave astronomy.

PubMed

Mureika, Jonas; Stojkovic, Dejan

2011-03-11

Lower dimensionality at higher energies has manifold theoretical advantages as recently pointed out by Anchordoqui et al. [arXiv:1003.5914]. Moreover, it appears that experimental evidence may already exist for it: A statistically significant planar alignment of events with energies higher than TeV has been observed in some earlier cosmic ray experiments. We propose a robust and independent test for this new paradigm. Since (2+1)-dimensional spacetimes have no gravitational degrees of freedom, gravity waves cannot be produced in that epoch. This places a universal maximum frequency at which primordial waves can propagate, marked by the transition between dimensions. We show that this cutoff frequency may be accessible to future gravitational wave detectors such as the Laser Interferometer Space Antenna.

Complete Sets of Radiating and Nonradiating Parts of a Source and Their Fields with Applications in Inverse Scattering Limited-Angle Problems

PubMed Central

Louis, A. K.

2006-01-01

Many algorithms applied in inverse scattering problems use source-field systems instead of the direct computation of the unknown scatterer. It is well known that the resulting source problem does not have a unique solution, since certain parts of the source totally vanish outside of the reconstruction area. This paper provides for the two-dimensional case special sets of functions, which include all radiating and all nonradiating parts of the source. These sets are used to solve an acoustic inverse problem in two steps. The problem under discussion consists of determining an inhomogeneous obstacle supported in a part of a disc, from data, known for a subset of a two-dimensional circle. In a first step, the radiating parts are computed by solving a linear problem. The second step is nonlinear and consists of determining the nonradiating parts. PMID:23165060

Conditionally Active Min-Max Limit Regulators

NASA Technical Reports Server (NTRS)

Garg, Sanjay (Inventor); May, Ryan D. (Inventor)

2017-01-01

A conditionally active limit regulator may be used to regulate the performance of engines or other limit regulated systems. A computing system may determine whether a variable to be limited is within a predetermined range of a limit value as a first condition. The computing system may also determine whether a current rate of increase or decrease of the variable to be limited is great enough that the variable will reach the limit within a predetermined period of time with no other changes as a second condition. When both conditions are true, the computing system may activate a simulated or physical limit regulator.

40 CFR 63.2378 - How do I demonstrate continuous compliance with the emission limitations, operating limits, and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... compliance with the emission limitations, operating limits, and work practice standards? 63.2378 Section 63... limits, and work practice standards? (a) You must demonstrate continuous compliance with each emission limitation, operating limit, and work practice standard in Tables 2 through 4 to this subpart that applies to...

Characteristics of chiral anomaly in view of various applications

NASA Astrophysics Data System (ADS)

Fujikawa, Kazuo

2018-01-01

In view of the recent applications of chiral anomaly to various fields beyond particle physics, we discuss some basic aspects of chiral anomaly which may help deepen our understanding of chiral anomaly in particle physics also. It is first shown that Berry's phase (and its generalization) for the Weyl model H =vFσ →.p →(t ) assumes a monopole form at the exact adiabatic limit but deviates from it off the adiabatic limit and vanishes in the high frequency limit of the Fourier transform of p →(t ) for bounded |p →(t )|. An effective action, which is consistent with the nonadiabatic limit of Berry's phase, combined with the Bjorken-Johnson-Low prescription, gives normal equal-time space-time commutators and no chiral anomaly. In contrast, an effective action with a monopole at the origin of the momentum space, which describes Berry's phase in the precise adiabatic limit but fails off the adiabatic limit, gives anomalous space-time commutators and a covariant anomaly to the gauge current. We regard this anomaly as an artifact of the postulated monopole and not a consequence of Berry's phase. As for the recent application of the chiral anomaly to the description of effective Weyl fermions in condensed matter and nuclear physics, which is closely related to the formulation of lattice chiral fermions, we point out that the chiral anomaly for each species doubler separately vanishes for a finite lattice spacing, contrary to the common assumption. Instead, a general form of pair creation associated with the spectral flow for the Dirac sea with finite depth takes place. This view is supported by the Ginsparg-Wilson fermion, which defines a single Weyl fermion without doublers on the lattice and gives a well-defined index (anomaly) even for a finite lattice spacing. A different use of anomaly in analogy to the partially conserved axial-vector current is also mentioned and could lead to an effect without fermion number nonconservation.

Psychological Disorders and Functional Limitations

ERIC Educational Resources Information Center

Brentar, John T.

2008-01-01

Psychological disorders lead to functional limitations that can impact a student's performance in school. These students are eligible for accommodations if they can demonstrate that a specific disability exists and that it substantially limits one or more major life activity. The most common functional limitations reported by this population…

Evolution of gas saturation and relative permeability during gas production from hydrate-bearing sediments: Gas invasion vs. gas nucleation

NASA Astrophysics Data System (ADS)

Jang, Jaewon; Santamarina, J. Carlos

2014-01-01

Capillarity and both gas and water permeabilities change as a function of gas saturation. Typical trends established in the discipline of unsaturated soil behavior are used when simulating gas production from hydrate-bearing sediments. However, the evolution of gas saturation and water drainage in gas invasion (i.e., classical soil behavior) and gas nucleation (i.e., gas production) is inherently different: micromodel experimental results show that gas invasion forms a continuous flow path while gas nucleation forms isolated gas clusters. Complementary simulations conducted using tube networks explore the implications of the two different desaturation processes. In spite of their distinct morphological differences in fluid displacement, numerical results show that the computed capillarity-saturation curves are very similar in gas invasion and nucleation (the gas-water interface confronts similar pore throat size distribution in both cases); the relative water permeability trends are similar (the mean free path for water flow is not affected by the topology of the gas phase); and the relative gas permeability is slightly lower in nucleation (delayed percolation of initially isolated gas-filled pores that do not contribute to gas conductivity). Models developed for unsaturated sediments can be used for reservoir simulation in the context of gas production from hydrate-bearing sediments, with minor adjustments to accommodate a lower gas invasion pressure Po and a higher gas percolation threshold.

Tunable nano-wrinkling of chiral surfaces: Structure and diffraction optics

NASA Astrophysics Data System (ADS)

Rofouie, P.; Pasini, D.; Rey, A. D.

2015-09-01

Periodic surface nano-wrinkling is found throughout biological liquid crystalline materials, such as collagen films, spider silk gland ducts, exoskeleton of beetles, and flower petals. These surface ultrastructures are responsible for structural colors observed in some beetles and plants that can dynamically respond to external conditions, such as humidity and temperature. In this paper, the formation of the surface undulations is investigated through the interaction of anisotropic interfacial tension, swelling through hydration, and capillarity at free surfaces. Focusing on the cellulosic cholesteric liquid crystal (CCLC) material model, the generalized shape equation for anisotropic interfaces using the Cahn-Hoffman capillarity vector and the Rapini-Papoular anchoring energy are applied to analyze periodic nano-wrinkling in plant-based plywood free surfaces with water-induced cholesteric pitch gradients. Scaling is used to derive the explicit relations between the undulations' amplitude expressed as a function of the anchoring strength and the spatially varying pitch. The optical responses of the periodic nano-structured surfaces are studied through finite difference time domain simulations indicating that CCLC surfaces with spatially varying pitch reflect light in a wavelength higher than that of a CCLC's surface with constant pitch. This structural color change is controlled by the pitch gradient through hydration. All these findings provide a foundation to understand structural color phenomena in nature and for the design of optical sensor devices.

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

Rofouie, P.; Rey, A. D., E-mail: alejandro.rey@mail.mcgill.ca; Pasini, D.

Periodic surface nano-wrinkling is found throughout biological liquid crystalline materials, such as collagen films, spider silk gland ducts, exoskeleton of beetles, and flower petals. These surface ultrastructures are responsible for structural colors observed in some beetles and plants that can dynamically respond to external conditions, such as humidity and temperature. In this paper, the formation of the surface undulations is investigated through the interaction of anisotropic interfacial tension, swelling through hydration, and capillarity at free surfaces. Focusing on the cellulosic cholesteric liquid crystal (CCLC) material model, the generalized shape equation for anisotropic interfaces using the Cahn-Hoffman capillarity vector and themore » Rapini-Papoular anchoring energy are applied to analyze periodic nano-wrinkling in plant-based plywood free surfaces with water-induced cholesteric pitch gradients. Scaling is used to derive the explicit relations between the undulations’ amplitude expressed as a function of the anchoring strength and the spatially varying pitch. The optical responses of the periodic nano-structured surfaces are studied through finite difference time domain simulations indicating that CCLC surfaces with spatially varying pitch reflect light in a wavelength higher than that of a CCLC’s surface with constant pitch. This structural color change is controlled by the pitch gradient through hydration. All these findings provide a foundation to understand structural color phenomena in nature and for the design of optical sensor devices.« less

g-LIMIT Status Briefing

NASA Technical Reports Server (NTRS)

Whorton, Mark; Perkins, Brad T.

2000-01-01

For many microgravity science experiments in the International Space Station, the ambient acceleration environment will be exceed desirable levels. To provide a more quiescent acceleration environment to the microgravity payloads, a vibration isolation system named g-LIMIT (GLovebox Integrated Microgravity Isolation Technology) is being designed. g-LIMIT is a sub-rack level isolation system that can be tailored to a variety of applications. Scheduled for launch on the UF-1 mission, the initial implementation of g-LIMIT will be a Characterization Test in the Microgravity Science Glovebox (MSG). g-LIMIT will be available to glovebox investigators immediately after characterization testing. Standard MSG structural and umbilical interfaces will be used so that the isolation mount is transparent to the user with no additional accommodation requirements. g-LIMIT consists of three integrated isolator modules, each of which is comprised of a dual axis actuator, two axes of acceleration sensing, two axes of position sensing, control electronics, and data transmission capabilities in a minimum-volume package. In addition, this system provides the unique capability for measuring absolute acceleration of the experiment independent of accelerometers as a by-product of the control system and will have the capability of generating pristine accelerations to enhance experiment operations.

7 CFR 773.8 - Limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... SPECIAL PROGRAMS SPECIAL APPLE LOAN PROGRAM § 773.8 Limitations. (a) The maximum loan amount any individual or business entity may receive under the Special Apple Loan Program is limited to $500,000. (b) The maximum loan is further limited to $300 per acre of apple trees in production in 1999 or 2000...

7 CFR 773.8 - Limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... SPECIAL PROGRAMS SPECIAL APPLE LOAN PROGRAM § 773.8 Limitations. (a) The maximum loan amount any individual or business entity may receive under the Special Apple Loan Program is limited to $500,000. (b) The maximum loan is further limited to $300 per acre of apple trees in production in 1999 or 2000...

7 CFR 773.8 - Limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... SPECIAL PROGRAMS SPECIAL APPLE LOAN PROGRAM § 773.8 Limitations. (a) The maximum loan amount any individual or business entity may receive under the Special Apple Loan Program is limited to $500,000. (b) The maximum loan is further limited to $300 per acre of apple trees in production in 1999 or 2000...

7 CFR 773.8 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... SPECIAL PROGRAMS SPECIAL APPLE LOAN PROGRAM § 773.8 Limitations. (a) The maximum loan amount any individual or business entity may receive under the Special Apple Loan Program is limited to $500,000. (b) The maximum loan is further limited to $300 per acre of apple trees in production in 1999 or 2000...

7 CFR 773.8 - Limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... SPECIAL PROGRAMS SPECIAL APPLE LOAN PROGRAM § 773.8 Limitations. (a) The maximum loan amount any individual or business entity may receive under the Special Apple Loan Program is limited to $500,000. (b) The maximum loan is further limited to $300 per acre of apple trees in production in 1999 or 2000...

Emissivity of freestanding membranes with thin metal coatings

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

Zwol, P. J. van, E-mail: Pieter-jan.van.zwol@asml.com; Vles, D. F.; Voorthuijzen, W. P.

Freestanding silicon nitride membranes with thicknesses down to a few tens of nanometers find use as TEM windows or soft X-ray spectral purity filters. As the thickness of a membrane decreases, emissivity vanishes, which limits radiative heat emission and resistance to heat loads. We show that thin metal layers with thicknesses in the order of 1 nm enhance the emissivity of thin membranes by two to three orders of magnitude close to the theoretical limit of 0.5. This considerably increases thermal load capacity of membranes in vacuum environments. Our experimental results are in line with classical theory in which we adaptmore » thickness dependent scattering terms in the Drude and Lorentz oscillators.« less

An asymptotically consistent approximant for the equatorial bending angle of light due to Kerr black holes

NASA Astrophysics Data System (ADS)

Barlow, Nathaniel S.; Weinstein, Steven J.; Faber, Joshua A.

2017-07-01

An accurate closed-form expression is provided to predict the bending angle of light as a function of impact parameter for equatorial orbits around Kerr black holes of arbitrary spin. This expression is constructed by assuring that the weak- and strong-deflection limits are explicitly satisfied while maintaining accuracy at intermediate values of impact parameter via the method of asymptotic approximants (Barlow et al 2017 Q. J. Mech. Appl. Math. 70 21-48). To this end, the strong deflection limit for a prograde orbit around an extremal black hole is examined, and the full non-vanishing asymptotic behavior is determined. The derived approximant may be an attractive alternative to computationally expensive elliptical integrals used in black hole simulations.

50 CFR 660.232 - Limited entry daily trip limit (DTL) fishery for sablefish.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Limited entry daily trip limit (DTL) fishery for sablefish. 660.232 Section 660.232 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST...

Space-charge limited photocurrent.

PubMed

Mihailetchi, V D; Wildeman, J; Blom, P W M

2005-04-01

In 1971 Goodman and Rose predicted the occurrence of a fundamental electrostatic limit for the photocurrent in semiconductors at high light intensities. Blends of conjugated polymers and fullerenes are an ideal model system to observe this space-charge limit experimentally, since they combine an unbalanced charge transport, long lifetimes, high charge carrier generation efficiencies, and low mobility of the slowest charge carrier. The experimental photocurrents reveal all the characteristics of a space-charge limited photocurrent: a one-half power dependence on voltage, a three-quarter power dependence on light intensity, and a one-half power scaling of the voltage at which the photocurrent switches into full saturation with light intensity.

Speed limits of aircraft

NASA Technical Reports Server (NTRS)

Everling, E

1923-01-01

This paper is restricted to the question of attainable speed limits and attacks the problem from different angles. Theoretical limits due to air resistance are presented along with design factors which may affect speed such as wing loads, wing areas, wing section shifting, landing speeds, drag-lift ratios, and power coefficients.

Viscocapillary Response of Gas Bubbles Probed by Thermal Noise Atomic Force Measurement.

PubMed

Wang, Yuliang; Zeng, Binglin; Alem, Hadush Tedros; Zhang, Zaicheng; Charlaix, Elisabeth; Maali, Abdelhamid

2018-01-30

We present thermal noise measurements of a vibrating sphere close to microsized air bubbles in water with an atomic force microscope. The sphere was glued at the end of a cantilever with a resonance frequency of few kHz. The subangstrom thermal motion of the microsphere reveals an elastohydrodynamic coupling between the sphere and the air bubble. The results are in perfect agreement with a model incorporating macroscopic capillarity and fluid flow on the bubble surface with full slip boundary conditions.

Fake conformal symmetry in unimodular gravity

NASA Astrophysics Data System (ADS)

Oda, Ichiro

2016-08-01

We study Weyl symmetry (local conformal symmetry) in unimodular gravity. It is shown that the Noether currents for both Weyl symmetry and global scale symmetry vanish exactly as in conformally invariant scalar-tensor gravity. We clearly explain why in the class of conformally invariant gravitational theories, the Noether currents vanish by starting with conformally invariant scalar-tensor gravity. Moreover, we comment on both classical and quantum-mechanical equivalences in Einstein's general relativity, conformally invariant scalar-tensor gravity, and the Weyl-transverse gravity. Finally, we discuss the Weyl current in the conformally invariant scalar action and see that it is also vanishing.

Hydrodynamic Limit of Multiple SLE

NASA Astrophysics Data System (ADS)

Hotta, Ikkei; Katori, Makoto

2018-04-01

Recently del Monaco and Schleißinger addressed an interesting problem whether one can take the limit of multiple Schramm-Loewner evolution (SLE) as the number of slits N goes to infinity. When the N slits grow from points on the real line R in a simultaneous way and go to infinity within the upper half plane H, an ordinary differential equation describing time evolution of the conformal map g_t(z) was derived in the N → ∞ limit, which is coupled with a complex Burgers equation in the inviscid limit. It is well known that the complex Burgers equation governs the hydrodynamic limit of the Dyson model defined on R studied in random matrix theory, and when all particles start from the origin, the solution of this Burgers equation is given by the Stieltjes transformation of the measure which follows a time-dependent version of Wigner's semicircle law. In the present paper, first we study the hydrodynamic limit of the multiple SLE in the case that all slits start from the origin. We show that the time-dependent version of Wigner's semicircle law determines the time evolution of the SLE hull, K_t \\subset H\\cup R, in this hydrodynamic limit. Next we consider the situation such that a half number of the slits start from a>0 and another half of slits start from -a < 0, and determine the multiple SLE in the hydrodynamic limit. After reporting these exact solutions, we will discuss the universal long-term behavior of the multiple SLE and its hull K_t in the hydrodynamic limit.

Passive fault current limiting device

DOEpatents

Evans, Daniel J.; Cha, Yung S.

1999-01-01

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

Passive fault current limiting device

DOEpatents

Evans, D.J.; Cha, Y.S.

1999-04-06

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

38 CFR 3.109 - Time limit.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Time limit. 3.109 Section..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time... and evidence originally submitted is not so included. (b) Extension of time limit. Time limits within...

38 CFR 3.109 - Time limit.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Time limit. 3.109 Section..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time... and evidence originally submitted is not so included. (b) Extension of time limit. Time limits within...

38 CFR 3.109 - Time limit.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Time limit. 3.109 Section..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time... and evidence originally submitted is not so included. (b) Extension of time limit. Time limits within...

38 CFR 3.109 - Time limit.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Time limit. 3.109 Section..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time... and evidence originally submitted is not so included. (b) Extension of time limit. Time limits within...

38 CFR 3.109 - Time limit.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Time limit. 3.109 Section..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time... and evidence originally submitted is not so included. (b) Extension of time limit. Time limits within...

7 CFR 762.122 - Loan limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Loan limitations. 762.122 Section 762.122 Agriculture... SPECIAL PROGRAMS GUARANTEED FARM LOANS § 762.122 Loan limitations. (a) Dollar limits. The Agency will not guarantee any loan that would result in the applicant's total indebtedness exceeding the limits established...

Fracture mechanics validity limits

NASA Technical Reports Server (NTRS)

Lambert, Dennis M.; Ernst, Hugo A.

1994-01-01

Fracture behavior is characteristics of a dramatic loss of strength compared to elastic deformation behavior. Fracture parameters have been developed and exhibit a range within which each is valid for predicting growth. Each is limited by the assumptions made in its development: all are defined within a specific context. For example, the stress intensity parameters, K, and the crack driving force, G, are derived using an assumption of linear elasticity. To use K or G, the zone of plasticity must be small as compared to the physical dimensions of the object being loaded. This insures an elastic response, and in this context, K and G will work well. Rice's J-integral has been used beyond the limits imposed on K and G. J requires an assumption of nonlinear elasticity, which is not characteristic of real material behavior, but is thought to be a reasonable approximation if unloading is kept to a minimum. As well, the constraint cannot change dramatically (typically, the crack extension is limited to ten-percent of the initial remaining ligament length). Rice, et al investigated the properties required of J-type parameters, J(sub x), and showed that the time rate, dJ(sub x)/dt, must not be a function of the crack extension rate, da/dt. Ernst devised the modified-J parameter, J(sub M), that meets this criterion. J(sub M) correlates fracture data to much higher crack growth than does J. Ultimately, a limit of the validity of J(sub M) is anticipated, and this has been estimated to be at a crack extension of about 40-percent of the initial remaining ligament length. None of the various parameters can be expected to describe fracture in an environment of gross plasticity, in which case the process is better described by deformation parameters, e.g., stress and strain. In the current study, various schemes to identify the onset of the plasticity-dominated behavior, i.e., the end of fracture mechanics validity, are presented. Each validity limit parameter is developed in

Measures of Cognitive Limitations and Their Relation to Perceived Work Limitations in Breast Cancer Survivors

DTIC Science & Technology

2009-03-06

impact work limitations in BCS and a Non-Cancer Comparison Group (NCCG) and to investigate the relationship between perceived and observed measures of...NCCG), and to investigate the relationship between perceived and observed measures of cognitive limitations, accounting for possible confounders in...accounting for proposed confounders; 3) replicate previous work indicating a stronger relationship between physical fatigue and work limitations in

5 CFR 2604.305 - Time limits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Time limits. 2604.305 Section 2604.305... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a... appeal. (c) Extension of time limits. The time limits specified in either paragraph (a) or (b) of this...

5 CFR 2604.305 - Time limits.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Time limits. 2604.305 Section 2604.305... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a... appeal. (c) Extension of time limits. The time limits specified in either paragraph (a) or (b) of this...

32 CFR 806.22 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Time limits. 806.22 Section 806.22 National... INFORMATION ACT PROGRAM § 806.22 Time limits. Any FOIA appeals received after the 60-day time limit are not processed, unless the requester provides adequate justification for failing to comply with the time limit...

32 CFR 806.22 - Time limits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Time limits. 806.22 Section 806.22 National... INFORMATION ACT PROGRAM § 806.22 Time limits. Any FOIA appeals received after the 60-day time limit are not processed, unless the requester provides adequate justification for failing to comply with the time limit...

5 CFR 2604.305 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Time limits. 2604.305 Section 2604.305... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a... appeal. (c) Extension of time limits. The time limits specified in either paragraph (a) or (b) of this...

5 CFR 2604.305 - Time limits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Time limits. 2604.305 Section 2604.305... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a... appeal. (c) Extension of time limits. The time limits specified in either paragraph (a) or (b) of this...

32 CFR 806.22 - Time limits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Time limits. 806.22 Section 806.22 National... INFORMATION ACT PROGRAM § 806.22 Time limits. Any FOIA appeals received after the 60-day time limit are not processed, unless the requester provides adequate justification for failing to comply with the time limit...

5 CFR 2604.305 - Time limits.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Time limits. 2604.305 Section 2604.305... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a... appeal. (c) Extension of time limits. The time limits specified in either paragraph (a) or (b) of this...

32 CFR 806.22 - Time limits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Time limits. 806.22 Section 806.22 National... INFORMATION ACT PROGRAM § 806.22 Time limits. Any FOIA appeals received after the 60-day time limit are not processed, unless the requester provides adequate justification for failing to comply with the time limit...

45 CFR 3.26 - Speed limit.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 1 2011-10-01 2011-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit. ...

45 CFR 3.26 - Speed limit.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit. ...

Nonlinearity Analysis for Efficient Modelling of Long-Term CO2 Storage

NASA Astrophysics Data System (ADS)

Li, Boxiao; Benson, Sally; Tchelepi, Hamdi

2014-05-01

Numerical simulation is widely used to predict the long-term fate of the injected CO2 in a storage formation. Performing large-scale simulations is often limited by the computational speed, where convergence failure of Newton iterations is one of the main bottlenecks. In order to design better numerical schemes and faster nonlinear solvers for modelling long-term CO2 storage, the nonlinearity in the simulations has to be analysed thoroughly, and the cause of convergence failures has to be identified clearly. We focus on the transport of CO2 and water in the presence of viscous, gravity, and heterogeneous capillary forces. We investigate the nonlinearity of the discrete transport equation obtained from finite-volume discretization with single-point phase-based upstream weighting, which is the industry standard. In particular, we study the discretized flux expressed as a function of saturations at the upstream and downstream (with respect to the total velocity) of each gridblock interface. We analyse the locations and complexity of the unit-flux, zero-flux, and inflection lines on the numerical flux. The unit- and zero-flux lines, referred to as kinks, correspond to a change of the flow direction, which often occurs when strong buoyancy and capillarity are present. We observe that these kinks and inflection lines are major sources of nonlinear convergence difficulties. We find that kinks create more challenges than inflection lines, especially when their locations depend on both the upstream and downstream saturations of the total velocity. When the flow is driven by viscous and gravity forces (e.g., during CO2 injection), one kink will occur in the numerical flux and its location depends only on the upstream saturation. However, when capillarity is dominant (e.g., during the post-injection period), two kinks will occur and both are functions of the upstream and downstream saturations, causing severe convergence difficulties particularly when heterogeneity is present

Persistence of the gapless spin liquid in the breathing kagome Heisenberg antiferromagnet

NASA Astrophysics Data System (ADS)

Iqbal, Yasir; Poilblanc, Didier; Thomale, Ronny; Becca, Federico

2018-03-01

The nature of the ground state of the spin S =1 /2 Heisenberg antiferromagnet on the kagome lattice with breathing anisotropy (i.e., with different superexchange couplings J▵ and J▿ within elementary up- and down-pointing triangles) is investigated within the framework of Gutzwiller projected fermionic wave functions and Monte Carlo methods. We analyze the stability of the U(1 ) Dirac spin liquid with respect to the presence of fermionic pairing that leads to a gapped Z2 spin liquid. For several values of the ratio J▿/J▵ , the size scaling of the energy gain due to the pairing fields and the variational parameters are reported. Our results show that the energy gain of the gapped spin liquid with respect to the gapless state either vanishes for large enough system size or scales to zero in the thermodynamic limit. Similarly, the optimized pairing amplitudes (responsible for opening the spin gap) are shown to vanish in the thermodynamic limit. Our outcome is corroborated by the application of one and two Lanczos steps to the gapless and gapped wave functions, for which no energy gain of the gapped state is detected when improving the quality of the variational states. Finally, we discuss the competition with the "simplex" Z2 resonating-valence-bond spin liquid, valence-bond crystal, and nematic states in the strongly anisotropic regime, i.e., J▿≪J▵ .

45 CFR 5.35 - Time limits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Time limits. 5.35 Section 5.35 Public Welfare... Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether... time limits, but if it appears that processing your request may take longer than we would wish, we will...

45 CFR 5.35 - Time limits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 1 2014-10-01 2014-10-01 false Time limits. 5.35 Section 5.35 Public Welfare... Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether... time limits, but if it appears that processing your request may take longer than we would wish, we will...

45 CFR 5.35 - Time limits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 1 2011-10-01 2011-10-01 false Time limits. 5.35 Section 5.35 Public Welfare... Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether... time limits, but if it appears that processing your request may take longer than we would wish, we will...

45 CFR 5.35 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 1 2012-10-01 2012-10-01 false Time limits. 5.35 Section 5.35 Public Welfare... Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether... time limits, but if it appears that processing your request may take longer than we would wish, we will...

45 CFR 5.35 - Time limits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 1 2013-10-01 2013-10-01 false Time limits. 5.35 Section 5.35 Public Welfare... Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether... time limits, but if it appears that processing your request may take longer than we would wish, we will...

Limits to magnetic resonance microscopy

NASA Astrophysics Data System (ADS)

Glover, Paul; Mansfield, Peter, Sir

2002-10-01

The last quarter of the twentieth century saw the development of magnetic resonance imaging (MRI) grow from a laboratory demonstration to a multi-billion dollar worldwide industry. There is a clinical body scanner in almost every hospital of the developed nations. The field of magnetic resonance microscopy (MRM), after mostly being abandoned by researchers in the first decade of MRI, has become an established branch of the science. This paper reviews the development of MRM over the last decade with an emphasis on the current state of the art. The fundamental principles of imaging and signal detection are examined to determine the physical principles which limit the available resolution. The limits are discussed with reference to liquid, solid and gas phase microscopy. In each area, the novel approaches employed by researchers to push back the limits of resolution are discussed. Although the limits to resolution are well known, the developments and applications of MRM have not reached their limit.

Force Limited Vibration Testing Monograph

NASA Technical Reports Server (NTRS)

Scharton, Terry D.

1997-01-01

The practice of limiting the shaker force in vibration tests was investigated at the NASA Jet Propulsion Laboratory (JPL) in 1990 after the mechanical failure of an aerospace component during a vibration test. Now force limiting is used in almost every major vibration test at JPL and in many vibration tests at NASA Goddard Space Flight Center (GSFC) and at many aerospace contractors. The basic ideas behind force limiting have been in the literature for several decades, but the piezo-electric force transducers necessary to conveniently implement force limiting have been available only in the last decade. In 1993, funding was obtained from the NASA headquarters Office of Chief Engineer to develop and document the technology needed to establish force limited vibration testing as a standard approach available to all NASA centers and aerospace contractors. This monograph is the final report on that effort and discusses the history, theory, and applications of the method in some detail.

The compensation of Gaussian curvature in developable cones is local

NASA Astrophysics Data System (ADS)

Wang, Jin; Witten, Thomas

2009-03-01

We use the angular deficit scheme[1] to determine numerically the distribution of Gaussian curvature in developable cones(d-cones)[2] formed by forcing a flat elastic sheet into a circular container so that the sheet buckles. This provides a new way to confirm the vanishing of mean-curvature[3] at the rim where the sheet touches the container. This angular deficit scheme also allows us to explore the potential role of the Gauss-Bonnet theorem in explaining the mean-curvature vanishing phenomenon. The theorem's global constraint on curvature resembles the global conditions observed to be relevant for vanishing mean curvature. However, our result suggests that the Gauss-Bonnet theorem does not explain the vanishing of mean-curvature. [1] V. Borrelli, F. Cazals, and J.-M. Morvan, Computer Aided Geometric Design 20, 319 (2003). [2] E. Cerda, S. Chaieb, F. Melo, and L. Mahadevan, Nature 401, 46 (1999). [3] T. Liang and T. A. Witten, Phys. Rev. E 73, 046604 (2006).

Quasilocal energy for three-dimensional massive gravity solutions with chiral deformations of AdS{sub 3} boundary conditions

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

Garbarz, Alan, E-mail: alan-at@df.uba.ar; Giribet, Gaston, E-mail: gaston-at@df.uba.ar, E-mail: af.goya-at@df.uba.ar; Goya, Andrés, E-mail: gaston-at@df.uba.ar, E-mail: af.goya-at@df.uba.ar

2015-03-26

We consider critical gravity in three dimensions; that is, the New Massive Gravity theory formulated about Anti-de Sitter (AdS) space with the specific value of the graviton mass for which it results dual to a two-dimensional conformai field theory with vanishing central charge. As it happens with Kerr black holes in four-dimensional critical gravity, in three-dimensional critical gravity the Bañados-Teitelboim-Zanelli black holes have vanishing mass and vanishing angular momentum. However, provided suitable asymptotic conditions are chosen, the theory may also admit solutions carrying non-vanishing charges. Here, we give simple examples of exact solutions that exhibit falling-off conditions that are evenmore » weaker than those of the so-called Log-gravity. For such solutions, we define the quasilocal stress-tensor and use it to compute conserved charges. Despite the drastic deformation of AdS{sub 3} asymptotic, these solutions have finite mass and angular momentum, which are shown to be non-zero.« less

One-dimensional photonic crystal optical limiter.

PubMed

Soon, Boon Yi; Haus, Joseph; Scalora, Michael; Sibilia, Concita

2003-08-25

We explore a new passive optical limiter design using transverse modulation instability in the one-dimensional photonic crystal (PC) using x(3) materials. The performance of PC optical limiters strongly depends on the choice of the materials and the geometry and it improves as the duration of the incident pulse is extended. PC optical limiter performance is compared with that of a device made from homogeneous material. We identify three criteria for benchmarking the PC optical limiter. We also include a discussion of the advantages and disadvantages of PC optical limiters for real world applications.

7 CFR 1400.106 - Payment limits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGRICULTURE GENERAL REGULATIONS AND POLICIES PAYMENT LIMITATION AND PAYMENT ELIGIBILITY FOR 2009 AND SUBSEQUENT CROP, PROGRAM, OR FISCAL YEARS Payment Limitation § 1400.106 Payment limits. (a) Payments made to...

On the Limitations of Biological Knowledge

PubMed Central

Dougherty, Edward R; Shmulevich, Ilya

2012-01-01

Scientific knowledge is grounded in a particular epistemology and, owing to the requirements of that epistemology, possesses limitations. Some limitations are intrinsic, in the sense that they depend inherently on the nature of scientific knowledge; others are contingent, depending on the present state of knowledge, including technology. Understanding limitations facilitates scientific research because one can then recognize when one is confronted by a limitation, as opposed to simply being unable to solve a problem within the existing bounds of possibility. In the hope that the role of limiting factors can be brought more clearly into focus and discussed, we consider several sources of limitation as they apply to biological knowledge: mathematical complexity, experimental constraints, validation, knowledge discovery, and human intellectual capacity. PMID:23633917

UV DRIVEN EVAPORATION OF CLOSE-IN PLANETS: ENERGY-LIMITED, RECOMBINATION-LIMITED, AND PHOTON-LIMITED FLOWS

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

Owen, James E.; Alvarez, Marcelo A., E-mail: jowen@ias.edu

2016-01-01

We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow timescale. When the recombination timescale is short compared to the flow timescale, the flow is in approximate local ionization equilibrium with a thin ionization front where the photon mean free path is short compared to the flow scale. In this “recombination-limited” flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow timescale the ionization frontmore » becomes thick and encompasses the entire flow with the mass-loss rate scaling linearly with flux. If the planet's potential is deep, then the flow is approximately “energy-limited”; however, if the planet's potential is shallow, then we identify a new limiting mass-loss regime, which we term “photon-limited.” In this scenario, the mass-loss rate is purely limited by the incoming flux of ionizing photons. We have developed a new numerical approach that takes into account the frequency dependence of the incoming ionizing spectrum and performed a large suite of 1D simulations to characterize UV driven mass-loss around low-mass planets. We find that the flow is “recombination-limited” at high fluxes but becomes “energy-limited” at low fluxes; however, the transition is broad occurring over several orders of magnitude in flux. Finally, we point out that the transitions between the different flow types do not occur at a single flux value but depend on the planet's properties, with higher-mass planets becoming “energy-limited” at lower fluxes.« less

Deriving exposure limits

NASA Astrophysics Data System (ADS)

Sliney, David H.

1990-07-01

Historically many different agencies and standards organizations have proposed laser occupational exposure limits (EL1s) or maximum permissible exposure (MPE) levels. Although some safety standards have been limited in scope to manufacturer system safety performance standards or to codes of practice most have included occupational EL''s. Initially in the 1960''s attention was drawn to setting EL''s however as greater experience accumulated in the use of lasers and some accident experience had been gained safety procedures were developed. It became clear by 1971 after the first decade of laser use that detailed hazard evaluation of each laser environment was too complex for most users and a scheme of hazard classification evolved. Today most countries follow a scheme of four major hazard classifications as defined in Document WS 825 of the International Electrotechnical Commission (IEC). The classifications and the associated accessible emission limits (AEL''s) were based upon the EL''s. The EL and AEL values today are in surprisingly good agreement worldwide. There exists a greater range of safety requirements for the user for each class of laser. The current MPE''s (i. e. EL''s) and their basis are highlighted in this presentation. 2. 0

Classical and sequential limit analysis revisited

NASA Astrophysics Data System (ADS)

Leblond, Jean-Baptiste; Kondo, Djimédo; Morin, Léo; Remmal, Almahdi

2018-04-01

Classical limit analysis applies to ideal plastic materials, and within a linearized geometrical framework implying small displacements and strains. Sequential limit analysis was proposed as a heuristic extension to materials exhibiting strain hardening, and within a fully general geometrical framework involving large displacements and strains. The purpose of this paper is to study and clearly state the precise conditions permitting such an extension. This is done by comparing the evolution equations of the full elastic-plastic problem, the equations of classical limit analysis, and those of sequential limit analysis. The main conclusion is that, whereas classical limit analysis applies to materials exhibiting elasticity - in the absence of hardening and within a linearized geometrical framework -, sequential limit analysis, to be applicable, strictly prohibits the presence of elasticity - although it tolerates strain hardening and large displacements and strains. For a given mechanical situation, the relevance of sequential limit analysis therefore essentially depends upon the importance of the elastic-plastic coupling in the specific case considered.

Optical limiting materials

DOEpatents

McBranch, D.W.; Mattes, B.R.; Koskelo, A.C.; Heeger, A.J.; Robinson, J.M.; Smilowitz, L.B.; Klimov, V.I.; Cha, M.; Sariciftci, N.S.; Hummelen, J.C.

1998-04-21

Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO{sub 2}) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400--1,100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes. 5 figs.

Metamorphosis

ERIC Educational Resources Information Center

Balch, Stephen H.

2012-01-01

One thing history's torrent appears to be sweeping away is, ironically, the study of its most productive wellspring, Western civilization. "The Vanishing West", a report the National Association of Scholars released in May 2011, documents the extent of this vanishing. The traditional Western civilization survey requirement, commonplace only…

48 CFR 1417.402 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 1417.402 Limitations. Use of leader company contracting for a product, subject to the limitations in FAR 17.402, shall require advance...

40 CFR 63.7500 - What emission limits, work practice standards, and operating limits must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Industrial, Commercial, and Institutional Boilers and Process Heaters Emission Limits and Work Practice... emission limit and work practice standard in Table 1 to this subpart that applies to your boiler or process... 40 Protection of Environment 13 2010-07-01 2010-07-01 false What emission limits, work practice...

Limits to Open Class Performance?

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2008-01-01

This presentation discusses open or unlimited class aircraft performance limitations and design solutions. Limitations in this class of aircraft include slow climbing flight which requires low wing loading, high cruise speed which requires high wing loading, gains in induced or viscous drag alone which result in only half the gain overall and other structural problems (yaw inertia and spins, flutter and static loads integrity). Design solutions include introducing minimum induced drag for a given span (elliptical span load or winglets) and introducing minimum induced drag for a bell shaped span load. It is concluded that open class performance limits (under current rules and technologies) is very close to absolute limits, though some gains remain to be made from unexplored areas and new technologies.

Transport of a Bose gas in 1D disordered lattices at the fluid-insulator transition.

PubMed

Tanzi, Luca; Lucioni, Eleonora; Chaudhuri, Saptarishi; Gori, Lorenzo; Kumar, Avinash; D'Errico, Chiara; Inguscio, Massimo; Modugno, Giovanni

2013-09-13

We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition.

Gaussian Mean Field Lattice Gas

NASA Astrophysics Data System (ADS)

Scoppola, Benedetto; Troiani, Alessio

2018-03-01

We study rigorously a lattice gas version of the Sherrington-Kirckpatrick spin glass model. In discrete optimization literature this problem is known as unconstrained binary quadratic programming and it belongs to the class NP-hard. We prove that the fluctuations of the ground state energy tend to vanish in the thermodynamic limit, and we give a lower bound of such ground state energy. Then we present a heuristic algorithm, based on a probabilistic cellular automaton, which seems to be able to find configurations with energy very close to the minimum, even for quite large instances.

Spectral sum rules for confining large-N theories

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

Cherman, Aleksey; McGady, David A.; Yamazaki, Masahito

2016-06-17

We consider asymptotically-free four-dimensional large-$N$ gauge theories with massive fermionic and bosonic adjoint matter fields, compactified on squashed three-spheres, and examine their regularized large-$N$ confined-phase spectral sums. The analysis is done in the limit of vanishing ’t Hooft coupling, which is justified by taking the size of the compactification manifold to be small compared to the inverse strong scale Λ ₋1. We find our results motivate us to conjecture some universal spectral sum rules for these large $N$ gauge theories.

Dense grid sibling frames with linear phase filters

NASA Astrophysics Data System (ADS)

Abdelnour, Farras

2013-09-01

We introduce new 5-band dyadic sibling frames with dense time-frequency grid. Given a lowpass filter satisfying certain conditions, the remaining filters are obtained using spectral factorization. The analysis and synthesis filterbanks share the same lowpass and bandpass filters but have different and oversampled highpass filters. This leads to wavelets approximating shift-invariance. The filters are FIR, have linear phase, and the resulting wavelets have vanishing moments. The filters are designed using spectral factorization method. The proposed method leads to smooth limit functions with higher approximation order, and computationally stable filterbanks.

Information processing occurs via critical avalanches in a model of the primary visual cortex

NASA Astrophysics Data System (ADS)

Bortolotto, G. S.; Girardi-Schappo, M.; Gonsalves, J. J.; Pinto, L. T.; Tragtenberg, M. H. R.

2016-01-01

We study a new biologically motivated model for the Macaque monkey primary visual cortex which presents power-law avalanches after a visual stimulus. The signal propagates through all the layers of the model via avalanches that depend on network structure and synaptic parameter. We identify four different avalanche profiles as a function of the excitatory postsynaptic potential. The avalanches follow a size-duration scaling relation and present critical exponents that match experiments. The structure of the network gives rise to a regime of two characteristic spatial scales, one of which vanishes in the thermodynamic limit.

Motion Among Random Obstacles on a Hyperbolic Space

NASA Astrophysics Data System (ADS)

Orsingher, Enzo; Ricciuti, Costantino; Sisti, Francesco

2016-02-01

We consider the motion of a particle along the geodesic lines of the Poincaré half-plane. The particle is specularly reflected when it hits randomly-distributed obstacles that are assumed to be motionless. This is the hyperbolic version of the well-known Lorentz Process studied in the Euclidean context. We analyse the limit in which the density of the obstacles increases to infinity and the size of each obstacle vanishes: under a suitable scaling, we prove that our process converges to a Markovian process, namely a random flight on the hyperbolic manifold.

Convergence of quantum electrodynamics in a curved modification of Minkowski space.

PubMed Central

Segal, I E; Zhou, Z

1994-01-01

The interaction and total hamiltonians for quantum electrodynamics, in the interaction representation, are entirely regular self-adjoint operators in Hilbert space, in the universal covering manifold M of the conformal compactification of Minkowski space Mo. (M is conformally equivalent to the Einstein universe E, in which Mo may be canonically imbedded.) In a fixed Lorentz frame this may be expressed as convergence in a spherical space with suitable periodic boundary conditions in time. The traditional relativistic theory is the formal limit of the present variant as the space curvature vanishes. PMID:11607455

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

Khan, Salman, E-mail: sksafi@comsats.edu.pk

The dynamics of tripartite entanglement of fermionic system in noninertial frames through linear contraction criterion when one or two observers are accelerated is investigated. In one observer accelerated case the entanglement measurement is not invariant with respect to the partial realignment of different subsystems and for two observers accelerated case it is invariant. It is shown that the acceleration of the frame does not generate entanglement in any bipartite subsystems. Unlike the bipartite states, the genuine tripartite entanglement does not completely vanish in both one observer accelerated and two observers accelerated cases even in the limit of infinite acceleration. Themore » degradation of tripartite entanglement is fast when two observers are accelerated than when one observer is accelerated. It is shown that tripartite entanglement is a better resource for quantum information processing than the bipartite entanglement in noninertial frames. - Highlights: • Tripartite entanglement of fermionic system in noninertial frames is studied. • Linear contraction criterion for quantifying tripartite entanglement is used. • Acceleration does not produce any bipartite entanglement. • The invariance of entanglement quantifier depends on accelerated observers. • The tripartite entanglement degrades against the acceleration, it never vanishes.« less

On the origin independence of the Verdet tensor†

NASA Astrophysics Data System (ADS)

Caputo, M. C.; Coriani, S.; Pelloni, S.; Lazzeretti, P.

2013-07-01

The condition for invariance under a translation of the coordinate system of the Verdet tensor and the Verdet constant, calculated via quantum chemical methods using gaugeless basis sets, is expressed by a vanishing sum rule involving a third-rank polar tensor. The sum rule is, in principle, satisfied only in the ideal case of optimal variational electronic wavefunctions. In general, it is not fulfilled in non-variational calculations and variational calculations allowing for the algebraic approximation, but it can be satisfied for reasons of molecular symmetry. Group-theoretical procedures have been used to determine (i) the total number of non-vanishing components and (ii) the unique components of both the polar tensor appearing in the sum rule and the axial Verdet tensor, for a series of symmetry groups. Test calculations at the random-phase approximation level of accuracy for water, hydrogen peroxide and ammonia molecules, using basis sets of increasing quality, show a smooth convergence to zero of the sum rule. Verdet tensor components calculated for the same molecules converge to limit values, estimated via large basis sets of gaugeless Gaussian functions and London orbitals.

Hydrodynamic mobility of a sphere moving on the centerline of an elastic tube

NASA Astrophysics Data System (ADS)

Daddi-Moussa-Ider, Abdallah; Lisicki, Maciej; Gekle, Stephan

2017-11-01

Elastic channels are an important component of many soft matter systems, in which hydrodynamic interactions with confining membranes determine the behavior of particles in flow. In this work, we derive analytical expressions for Green's functions associated with a point-force (Stokeslet) directed parallel or perpendicular to the axis of an elastic cylindrical channel exhibiting resistance against shear and bending. We then compute the leading order self- and pair mobility functions of particles on the cylinder axis, finding that the mobilities are primarily determined by membrane shear and that bending does not play a significant role. In the quasi-steady limit of vanishing frequency, the particle self- and pair mobilities near a no-slip hard cylinder are recovered only if the membrane possesses a non-vanishing shear rigidity. We further compute the membrane deformation, finding that deformation is generally more pronounced in the axial (radial) directions, for the motion along (perpendicular to) the cylinder centerline, respectively. Our analytical calculations for Green's functions in an elastic cylinder can serve as a fundamental building block for future studies and are verified by fully resolved boundary integral simulations where very good agreement is obtained.

Chiral current generation in QED by longitudinal photons

NASA Astrophysics Data System (ADS)

Acosta Avalo, J. L.; Pérez Rojas, H.

2016-08-01

We report the generation of a pseudovector electric current having imbalanced chirality in an electron-positron strongly magnetized gas in QED. It propagates along the external applied magnetic field B as a chiral magnetic effect in QED. It is triggered by a perturbative electric field parallel to B, associated to a pseudovector longitudinal mode propagating along B. An electromagnetic chemical potential was introduced, but our results remain valid even when it vanishes. A nonzero fermion mass was assumed, which is usually considered vanishing in the literature. In the quantum field theory formalism at finite temperature and density, an anomaly relation for the axial current was found for a medium of massive fermions. It bears some analogy to the Adler-Bell-Jackiw anomaly. From the expression for the chiral current in terms of the photon self-energy tensor in a medium, it is obtained that electrons and positrons scattered by longitudinal photons (inside the light cone) contribute to the chiral current, as well as the to pair creation due to longitudinal photons (out of light cone). In the static limit, an electric pseudovector current is obtained in the lowest Landau level.

Fate of inflation and the natural reduction of vacuum energy

NASA Astrophysics Data System (ADS)

Nakamichi, Akika; Morikawa, Masahiro

2014-04-01

In the standard cosmology, an artificial fine tuning of the potential is inevitable for vanishing cosmological constant, though slow-rolling uniform scalar field easily causes cosmic inflation. We focus on the general fact that any potential with negative region can temporally halt the cosmic expansion at the end of inflation, where the field tends to diverge. This violent evolution naturally causes particle production and strong instability of the uniform configuration of the fields. Decaying of this uniform scalar field would leave vanishing cosmological constant as well as locally collapsed objects. The universe then continues to evolve into the standard Freedman model. We study the detail of the instability, based on the linear analysis, and the subsequent fate of the scalar field, based on the non-linear numerical analysis. The collapsed scalar field would easily exceed the Kaup limiting mass and forms primordial black holes, which may play an important role in galaxy formation in later stages of cosmic expansion. We systematically describe the above scenario by identifying the scalar field as the boson field condensation (BEC) and the inflation as the process of phase transition of them.

Optimal Limited Contingency Planning

NASA Technical Reports Server (NTRS)

Meuleau, Nicolas; Smith, David E.

2003-01-01

For a given problem, the optimal Markov policy over a finite horizon is a conditional plan containing a potentially large number of branches. However, there are applications where it is desirable to strictly limit the number of decision points and branches in a plan. This raises the question of how one goes about finding optimal plans containing only a limited number of branches. In this paper, we present an any-time algorithm for optimal k-contingency planning. It is the first optimal algorithm for limited contingency planning that is not an explicit enumeration of possible contingent plans. By modelling the problem as a partially observable Markov decision process, it implements the Bellman optimality principle and prunes the solution space. We present experimental results of applying this algorithm to some simple test cases.

Vacuum currents in braneworlds on AdS bulk with compact dimensions

NASA Astrophysics Data System (ADS)

Bellucci, S.; Saharian, A. A.; Vardanyan, V.

2015-11-01

The two-point function and the vacuum expectation value (VEV) of the current density are investigated for a massive charged scalar field with arbitrary curvature coupling in the geometry of a brane on the background of AdS spacetime with partial toroidal compactification. The presence of a gauge field flux, enclosed by compact dimensions, is assumed. On the brane the field obeys Robin boundary condition and along compact dimensions periodicity conditions with general phases are imposed. There is a range in the space of the values for the coefficient in the boundary condition where the Poincaré vacuum is unstable. This range depends on the location of the brane and is different for the regions between the brane and AdS boundary and between the brane and the horizon. In models with compact dimensions the stability condition is less restrictive than that for the AdS bulk with trivial topology. The vacuum charge density and the components of the current along non-compact dimensions vanish. The VEV of the current density along compact dimensions is a periodic function of the gauge field flux with the period equal to the flux quantum. It is decomposed into the boundary-free and brane-induced contributions. The asymptotic behavior of the latter is investigated near the brane, near the AdS boundary and near the horizon. It is shown that, in contrast to the VEVs of the field squared an denergy-momentum tensor, the current density is finite on the brane and vanishes for the special case of Dirichlet boundary condition. Both the boundary-free and brane-induced contributions vanish on the AdS boundary. The brane-induced contribution vanishes on the horizon and for points near the horizon the current is dominated by the boundary-free part. In the near-horizon limit, the latter is connected to the corresponding quantity for a massless field in the Minkowski bulk by a simple conformal relation. Depending on the value of the Robin coefficient, the presence of the brane can either

Two phase flow and heat transfer in porous beds under variable body forces, part 2

NASA Technical Reports Server (NTRS)

Evers, J. L.; Henry, H. R.

1969-01-01

Analytical and experimental investigations of a pilot model of a channel for the study of two-phase flow under low or zero gravity are presented. The formulation of dimensionless parameters to indicate the relative magnitude of the effects of capillarity, gravity, pressure gradient, viscosity, and inertia is described. The investigation is based on the principal equations of fluid mechanics and thermodynamics. Techniques were investigated by using a laser velocimeter for measuring point velocities of the fluid within the porous material without disturbing the flow.

50 CFR 622.456 - Bag limits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of Puerto Rico and the U.S. Virgin Islands § 622.456 Bag limits. (a) Applicability. Section 622.11(a... fishing license issued by Puerto Rico or the U.S. Virgin Islands. (b) Bag limit. The bag limit for spiny...

40 CFR Table 3 to Subpart Jjjjjj... - Operating Limits for Boilers With Emission Limits

Code of Federal Regulations, 2012 CFR

2012-07-01

... performance test demonstrating compliance with the PM emission limitation. 4. Dry sorbent or carbon injection control Maintain the sorbent or carbon injection rate at or above the lowest 2-hour average sorbent flow... emissions limitation. When your boiler operates at lower loads, multiply your sorbent or carbon injection...

(0,2) elephants

NASA Astrophysics Data System (ADS)

Aspinwall, Paul S.; Melnikov, Ilarion V.; Plesser, M. Ronen

2012-01-01

We enumerate massless E6 singlets for (0,2)-compactifications of the heterotic string on a Calabi-Yau threefold with the "standard embedding" in three distinct ways. In the large radius limit of the threefold, these singlets count deformations of the Calabi-Yau together with its tangent bundle. In the "small-radius" limit we apply Landau-Ginzburg methods. In the orbifold limit we use a combination of geometry and free field methods. In general these counts differ. We show how to identify states between these phases and how certain states vanish from the massless spectrum as one deforms the complex structure or Kähler form away from the Gepner point. The appearance of extra singlets for particular values of complex structure is explored in all three pictures, and our results suggest that this does not depend on the Kähler moduli.

Enhanced Detectability of Community Structure in Multilayer Networks through Layer Aggregation.

PubMed

Taylor, Dane; Shai, Saray; Stanley, Natalie; Mucha, Peter J

2016-06-03

Many systems are naturally represented by a multilayer network in which edges exist in multiple layers that encode different, but potentially related, types of interactions, and it is important to understand limitations on the detectability of community structure in these networks. Using random matrix theory, we analyze detectability limitations for multilayer (specifically, multiplex) stochastic block models (SBMs) in which L layers are derived from a common SBM. We study the effect of layer aggregation on detectability for several aggregation methods, including summation of the layers' adjacency matrices for which we show the detectability limit vanishes as O(L^{-1/2}) with increasing number of layers, L. Importantly, we find a similar scaling behavior when the summation is thresholded at an optimal value, providing insight into the common-but not well understood-practice of thresholding pairwise-interaction data to obtain sparse network representations.

10 CFR 503.22 - Site limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... more specific physical limitations relevant to the location or operation of the proposed facility exist... of these regulations. Note: Examples of the types of site limitations to which a petitioner may... of a specific physical limitation; (ii) Unavailability of transportation facilities for alternate...

10 CFR 503.22 - Site limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... more specific physical limitations relevant to the location or operation of the proposed facility exist... of these regulations. Note: Examples of the types of site limitations to which a petitioner may... of a specific physical limitation; (ii) Unavailability of transportation facilities for alternate...

40 CFR 60.4860 - Do the emission limits, emission standards, and operating limits apply during periods of startup...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Do the emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and malfunction? 60.4860 Section... emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and...

40 CFR 60.4860 - Do the emission limits, emission standards, and operating limits apply during periods of startup...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Do the emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and malfunction? 60.4860 Section... emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and...

40 CFR 60.4860 - Do the emission limits, emission standards, and operating limits apply during periods of startup...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Do the emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and malfunction? 60.4860 Section... emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and...

40 CFR 60.4860 - Do the emission limits, emission standards, and operating limits apply during periods of startup...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Do the emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and malfunction? 60.4860 Section... emission limits, emission standards, and operating limits apply during periods of startup, shutdown, and...

50 CFR 622.43 - Commercial trip limits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Reef Fish Resources of the Gulf of Mexico § 622.43 Commercial trip limits. Commercial trip limits are limits on the... with any trip or possession limit applicable to state waters. A species subject to a trip limit...

The hydraulic limitation hypothesis revisited.

PubMed

Ryan, Michael G; Phillips, Nathan; Bond, Barbara J

2006-03-01

We proposed the hydraulic limitation hypothesis (HLH) as a mechanism to explain universal patterns in tree height, and tree and stand biomass growth: height growth slows down as trees grow taller, maximum height is lower for trees of the same species on resource-poor sites and annual wood production declines after canopy closure for even-aged forests. Our review of 51 studies that measured one or more of the components necessary for testing the hypothesis showed that taller trees differ physiologically from shorter, younger trees. Stomatal conductance to water vapour (g(s)), photosynthesis (A) and leaf-specific hydraulic conductance (K L) are often, but not always, lower in taller trees. Additionally, leaf mass per area is often greater in taller trees, and leaf area:sapwood area ratio changes with tree height. We conclude that hydraulic limitation of gas exchange with increasing tree size is common, but not universal. Where hydraulic limitations to A do occur, no evidence supports the original expectation that hydraulic limitation of carbon assimilation is sufficient to explain observed declines in wood production. Any limit to height or height growth does not appear to be related to the so-called age-related decline in wood production of forests after canopy closure. Future work on this problem should explicitly link leaf or canopy gas exchange with tree and stand growth, and consider a more fundamental assumption: whether tree biomass growth is limited by carbon availability.

40 CFR Table 3 to Subpart Jjjjjj... - Operating Limits for Boilers With Emission Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

... using . . . You must meet these operating limits except during periods of startup and shutdown . . . 1... the injection rate operating limit by 0.5). 5. Any other add-on air pollution control type. This... equal to 10 percent opacity (daily block average). 6. Fuel analysis Maintain the fuel type or fuel...

Grassland productivity limited by multiple nutrients.

PubMed

Fay, Philip A; Prober, Suzanne M; Harpole, W Stanley; Knops, Johannes M H; Bakker, Jonathan D; Borer, Elizabeth T; Lind, Eric M; MacDougall, Andrew S; Seabloom, Eric W; Wragg, Peter D; Adler, Peter B; Blumenthal, Dana M; Buckley, Yvonne M; Chu, Chengjin; Cleland, Elsa E; Collins, Scott L; Davies, Kendi F; Du, Guozhen; Feng, Xiaohui; Firn, Jennifer; Gruner, Daniel S; Hagenah, Nicole; Hautier, Yann; Heckman, Robert W; Jin, Virginia L; Kirkman, Kevin P; Klein, Julia; Ladwig, Laura M; Li, Qi; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Morgan, John W; Risch, Anita C; Schütz, Martin; Stevens, Carly J; Wedin, David A; Yang, Louie H

2015-07-06

Terrestrial ecosystem productivity is widely accepted to be nutrient limited(1). Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)(2,3), the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized(4-8). However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment.

STOCHASTIC DUELS OF LIMITED TIME-DURATION,

DTIC Science & Technology

This paper continues the development of the theory of stochastic duels to include the case where there is a time limitation on the duration of the... duel . An example of this situation is fighter-bomber combat in which the fighter has a very limited fuel supply. In this duel , two contestants (with...variable or (2) constant. The duel proceeds until one or both of the contestants are killed or until the time limit is exceeded. The time limit is either

Limits to Open Class Performance?

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2007-01-01

This viewgraph presentation describes the limits to open class performance. The contents include: 1) Standard Class; 2) 15m/Racing Class; 3) Open Class; and 4) Design Solutions associated with assumptions, limiting parameters, airfoil performance, current trends, and analysis.

10 CFR 503.33 - Site limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... more specific physical limitations relevant to the location or operation of the proposed facility exist... types of site limitations to which a petitioner may certify in order to qualify for this exemption include: (i) Inaccessibility of alternate fuels as a result of a specific physical limitation; (ii...

10 CFR 503.33 - Site limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... more specific physical limitations relevant to the location or operation of the proposed facility exist... types of site limitations to which a petitioner may certify in order to qualify for this exemption include: (i) Inaccessibility of alternate fuels as a result of a specific physical limitation; (ii...

10 CFR 503.33 - Site limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... more specific physical limitations relevant to the location or operation of the proposed facility exist... types of site limitations to which a petitioner may certify in order to qualify for this exemption include: (i) Inaccessibility of alternate fuels as a result of a specific physical limitation; (ii...

10 CFR 503.33 - Site limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... more specific physical limitations relevant to the location or operation of the proposed facility exist... types of site limitations to which a petitioner may certify in order to qualify for this exemption include: (i) Inaccessibility of alternate fuels as a result of a specific physical limitation; (ii...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

48 CFR 1346.705 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Limitations. 1346.705 Section 1346.705 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 1346.705 Limitations. Warranties in cost reimbursement contracts are authorized. ...

Electron and hole transport in the organic small molecule α-NPD

NASA Astrophysics Data System (ADS)

Rohloff, R.; Kotadiya, N. B.; Crǎciun, N. I.; Blom, P. W. M.; Wetzelaer, G. A. H.

2017-02-01

Electron and hole transport properties of the organic small molecule N,N'-Di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine are investigated by space-charge-limited current measurements. The hole transport shows trap-free behavior with a mobility of 2.3 × 10-8 m2/Vs at vanishing carrier density and electric field. The electron transport, on the other hand, shows heavily trap-limited behavior, which leads to highly unbalanced transport. A trap concentration of 1.3 × 1024 m-3 was found by modeling the electron currents, similar to the universal trap concentration found in conjugated polymers. This indicates that electron trapping is a generic property of organic semiconductors, ranging from vacuum-deposited small-molecules to solution-processed conjugated polymers.

Emergent SO(3) Symmetry of the Frictionless Shear Jamming Transition

NASA Astrophysics Data System (ADS)

Baity-Jesi, Marco; Goodrich, Carl P.; Liu, Andrea J.; Nagel, Sidney R.; Sethna, James P.

2017-05-01

We study the shear jamming of athermal frictionless soft spheres, and find that in the thermodynamic limit, a shear-jammed state exists with different elastic properties from the isotropically-jammed state. For example, shear-jammed states can have a non-zero residual shear stress in the thermodynamic limit that arises from long-range stress-stress correlations. As a result, the ratio of the shear and bulk moduli, which in isotropically-jammed systems vanishes as the jamming transition is approached from above, instead approaches a constant. Despite these striking differences, we argue that in a deeper sense, the shear jamming and isotropic jamming transitions actually have the same symmetry, and that the differences can be fully understood by rotating the six-dimensional basis of the elastic modulus tensor.

Thermal rectification in anharmonic chains under an energy-conserving noise.

PubMed

Guimarães, Pedro H; Landi, Gabriel T; de Oliveira, Mário J

2015-12-01

Systems in which the heat flux depends on the direction of the flow are said to present thermal rectification. This effect has attracted much theoretical and experimental interest in recent years. However, in most theoretical models the effect is found to vanish in the thermodynamic limit, in disagreement with experiment. The purpose of this paper is to show that the rectification may be restored by including an energy-conserving noise which randomly flips the velocity of the particles with a certain rate λ. It is shown that as long as λ is nonzero, the rectification remains finite in the thermodynamic limit. This is illustrated in a classical harmonic chain subject to a quartic pinning potential (the Φ(4) model) and coupled to heat baths by Langevin equations.

Communication: A simple full range analytical potential for H{sub 2} b{sup 3}∑{sub u}{sup +}, H–He {sup 2}∑{sup +}, and He{sub 2} {sup 1}∑{sub g}{sup +}

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

Warnecke, Sascha; Toennies, J. Peter, E-mail: jtoenni@gwdg.de; Tang, K. T.

The Tang-Toennies potential for the weakly interacting systems H{sub 2} b{sup 3}Σ{sub u}{sup +}, H–He {sup 2}Σ{sup +}, and He{sub 2} {sup 1}Σ{sub g}{sup +} is extended down to the united atom limit of vanishing internuclear distance. A simple analytic expression connects the united atom limiting potential with the Tang-Toennies potential in the well region. The new potential model is compared with the most recent ab initio calculations for all three systems. The agreement is better than 20% (H{sub 2} and He{sub 2}) or comparable with the differences in the available ab initio calculations (H–He) over six orders of magnitudemore » corresponding to the entire range of internuclear distances.« less

12 CFR 24.4 - Investment limits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Investment limits. 24.4 Section 24.4 Banks and... ENTITIES, COMMUNITY DEVELOPMENT PROJECTS, AND OTHER PUBLIC WELFARE INVESTMENTS § 24.4 Investment limits. (a) Limits on aggregate outstanding investments. A national bank's aggregate outstanding investments under...

12 CFR 24.4 - Investment limits.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Investment limits. 24.4 Section 24.4 Banks and... ENTITIES, COMMUNITY DEVELOPMENT PROJECTS, AND OTHER PUBLIC WELFARE INVESTMENTS § 24.4 Investment limits. (a) Limits on aggregate outstanding investments. A national bank's aggregate outstanding investments under...

7 CFR 762.122 - Loan limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 7 2014-01-01 2014-01-01 false Loan limitations. 762.122 Section 762.122 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS GUARANTEED FARM LOANS § 762.122 Loan limitations. (a) Dollar limits. The Agency will not...

43 CFR 10010.14 - Time limits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Time limits. 10010.14 Section 10010.14 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Initiating the NEPA Process § 10010.14 Time limits. When time limits are established to prepare an...

43 CFR 10010.14 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Time limits. 10010.14 Section 10010.14 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Initiating the NEPA Process § 10010.14 Time limits. When time limits are established to prepare an...

43 CFR 10010.14 - Time limits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Time limits. 10010.14 Section 10010.14 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Initiating the NEPA Process § 10010.14 Time limits. When time limits are established to prepare an...

High temperature superconducting fault current limiter

DOEpatents

Hull, J.R.

1997-02-04

A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

26 CFR 1.1502-93 - Consolidated section 382 limitation (or subgroup section 382 limitation).

Code of Federal Regulations, 2010 CFR

2010-04-01

...) for any post-change year is an amount equal to the value of the loss group (or loss subgroup), as.... See, for example, section 382(b)(2) (relating to the carryforward of unused section 382 limitation), section 382(b)(3)(B) (relating to the section 382 limitation for the post-change year that includes the...

48 CFR 1246.705 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Limitations. 1246.705 Section 1246.705 Federal Acquisition Regulations System DEPARTMENT OF TRANSPORTATION CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 1246.705 Limitations. (a) The following restrictions are applicable to DOT...

48 CFR 246.705 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Limitations. 246.705 Section 246.705 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 246.705 Limitations. (a) In addition to...

Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments

PubMed Central

Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

2017-01-01

Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum's long duration of vegetative growth increased water capture and biomass yield by ~30% compared to short season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by development

Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments.

PubMed

Truong, Sandra K; McCormick, Ryan F; Mullet, John E

2017-01-01

Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum's long duration of vegetative growth increased water capture and biomass yield by ~30% compared to short season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by development

Bioenergy sorghum crop model predicts VPD-limited transpiration traits enhance biomass yield in water-limited environments

DOE PAGES

Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

2017-03-21

Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum’s long duration of vegetative growth increased water capture and biomass yield by ~30% compared to shortmore » season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by

Bioenergy sorghum crop model predicts VPD-limited transpiration traits enhance biomass yield in water-limited environments

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

Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum’s long duration of vegetative growth increased water capture and biomass yield by ~30% compared to shortmore » season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by

42 CFR 93.105 - Time limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Time limitations. 93.105 Section 93.105 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH... MISCONDUCT General § 93.105 Time limitations. (a) Six-year limitation. This part applies only to research...

38 CFR 21.1033 - Time limits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Time limits. 21.1033... Time limits. The provisions of this section are applicable to informal claims and formal claims. (a) Failure to furnish form, information, or notice of time limit. VA's failure to give a claimant or...

38 CFR 21.1033 - Time limits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Time limits. 21.1033... Time limits. The provisions of this section are applicable to informal claims and formal claims. (a) Failure to furnish form, information, or notice of time limit. VA's failure to give a claimant or...

38 CFR 21.1033 - Time limits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Time limits. 21.1033... Time limits. The provisions of this section are applicable to informal claims and formal claims. (a) Failure to furnish form, information, or notice of time limit. VA's failure to give a claimant or...

38 CFR 21.1033 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Time limits. 21.1033... Time limits. The provisions of this section are applicable to informal claims and formal claims. (a) Failure to furnish form, information, or notice of time limit. VA's failure to give a claimant or...

42 CFR 93.105 - Time limitations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Time limitations. 93.105 Section 93.105 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH... MISCONDUCT General § 93.105 Time limitations. (a) Six-year limitation. This part applies only to research...

49 CFR 663.9 - Audit limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Audit limitations. 663.9 Section 663.9..., DEPARTMENT OF TRANSPORTATION PRE-AWARD AND POST-DELIVERY AUDITS OF ROLLING STOCK PURCHASES General § 663.9 Audit limitations. (a) An audit under this part is limited to verifying compliance with (1) Applicable...

High temperature superconducting fault current limiter

DOEpatents

Hull, John R.

1997-01-01

A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

46 CFR 45.187 - Weather limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

46 CFR 45.187 - Weather limitations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

46 CFR 45.187 - Weather limitations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

46 CFR 45.187 - Weather limitations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

46 CFR 45.187 - Weather limitations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Weather limitations. 45.187 Section 45.187 Shipping... River Barges on Lake Michigan Routes § 45.187 Weather limitations. (a) Tows on the Burns Harbor route must operate during fair weather conditions only. (b) The weather limits (ice conditions, wave height...

7 CFR 52.3185 - Moisture limits.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits for the applicable grades and kind and...

7 CFR 52.3185 - Moisture limits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits for...

7 CFR 52.3185 - Moisture limits.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits for...

50 CFR 38.13 - Speed limits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks...

50 CFR 622.56 - Size limits.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Shrimp Fishery of the Gulf of Mexico § 622.56 Size limits. Shrimp not in compliance with the applicable size limit as... shrimp harvested in the Gulf EEZ are subject to the minimum-size landing and possession limits of...

50 CFR 622.56 - Size limits.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Shrimp Fishery of the Gulf of Mexico § 622.56 Size limits. Shrimp not in compliance with the applicable size limit as... shrimp harvested in the Gulf EEZ are subject to the minimum-size landing and possession limits of...

47 CFR 73.1725 - Limited time.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Limited time. 73.1725 Section 73.1725... Rules Applicable to All Broadcast Stations § 73.1725 Limited time. (a) Operation is applicable only to... stations on the channel. (b) No authorization will be granted for: (1) A new limited time station; (2) A...

44 CFR 11.72 - Time limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Time limitations. 11.72... HOMELAND SECURITY GENERAL CLAIMS Personnel Claims Regulations § 11.72 Time limitations. (a) A claim under... after it accrues; (2) or if it cannot be filed within the time limits of paragraph (a)(1) of this...

18 CFR 401.109 - Time limitations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Time limitations. 401... ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Public Access to Records and Information § 401.109 Time limitations. (a) All time limitations established pursuant to this section shall begin as of the time at which...

22 CFR 503.4 - Time limits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Time limits. 503.4 Section 503.4 Foreign Relations BROADCASTING BOARD OF GOVERNORS FREEDOM OF INFORMATION ACT REGULATION § 503.4 Time limits. (a) General. The FOIA sets certain time limits for us to decide whether to disclose the records you requested...

18 CFR 401.109 - Time limitations.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Time limitations. 401... ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Public Access to Records and Information § 401.109 Time limitations. (a) All time limitations established pursuant to this section shall begin as of the time at which...

44 CFR 11.72 - Time limitations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Time limitations. 11.72... HOMELAND SECURITY GENERAL CLAIMS Personnel Claims Regulations § 11.72 Time limitations. (a) A claim under... after it accrues; (2) or if it cannot be filed within the time limits of paragraph (a)(1) of this...

19 CFR 145.23 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 2 2012-04-01 2012-04-01 false Time limits. 145.23 Section 145.23 Customs Duties... (CONTINUED) MAIL IMPORTATIONS Administrative Review of Mail Entries § 145.23 Time limits. A mail entry made.... 1520(c)), only if the addressee requests such amendment within the time limits prescribed therein (see...

44 CFR 11.72 - Time limitations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Time limitations. 11.72... HOMELAND SECURITY GENERAL CLAIMS Personnel Claims Regulations § 11.72 Time limitations. (a) A claim under... after it accrues; (2) or if it cannot be filed within the time limits of paragraph (a)(1) of this...

19 CFR 145.23 - Time limits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 2 2011-04-01 2011-04-01 false Time limits. 145.23 Section 145.23 Customs Duties... (CONTINUED) MAIL IMPORTATIONS Administrative Review of Mail Entries § 145.23 Time limits. A mail entry made.... 1520(c)), only if the addressee requests such amendment within the time limits prescribed therein (see...

18 CFR 401.109 - Time limitations.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Time limitations. 401... ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Public Access to Records and Information § 401.109 Time limitations. (a) All time limitations established pursuant to this section shall begin as of the time at which...

40 CFR 1501.8 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Time limits. 1501.8 Section 1501.8 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.8 Time limits. Although the Council has decided that prescribed universal time limits for the entire NEPA process are too...

22 CFR 503.4 - Time limits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Time limits. 503.4 Section 503.4 Foreign Relations BROADCASTING BOARD OF GOVERNORS FREEDOM OF INFORMATION ACT REGULATION § 503.4 Time limits. (a) General. The FOIA sets certain time limits for us to decide whether to disclose the records you requested...

47 CFR 73.1725 - Limited time.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Limited time. 73.1725 Section 73.1725... Rules Applicable to All Broadcast Stations § 73.1725 Limited time. (a) Operation is applicable only to... stations on the channel. (b) No authorization will be granted for: (1) A new limited time station; (2) A...

22 CFR 503.4 - Time limits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Time limits. 503.4 Section 503.4 Foreign Relations BROADCASTING BOARD OF GOVERNORS FREEDOM OF INFORMATION ACT REGULATION § 503.4 Time limits. (a) General. The FOIA sets certain time limits for us to decide whether to disclose the records you requested...

47 CFR 73.1725 - Limited time.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Limited time. 73.1725 Section 73.1725... Rules Applicable to All Broadcast Stations § 73.1725 Limited time. (a) Operation is applicable only to... stations on the channel. (b) No authorization will be granted for: (1) A new limited time station; (2) A...

22 CFR 503.4 - Time limits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Time limits. 503.4 Section 503.4 Foreign Relations BROADCASTING BOARD OF GOVERNORS FREEDOM OF INFORMATION ACT REGULATION § 503.4 Time limits. (a) General. The FOIA sets certain time limits for us to decide whether to disclose the records you requested...

18 CFR 401.109 - Time limitations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Time limitations. 401... ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Public Access to Records and Information § 401.109 Time limitations. (a) All time limitations established pursuant to this section shall begin as of the time at which...