A sphingolipid-dependent diffusion barrier confines ER stress to the yeast mother cell

Science.gov (United States)

Clay, Lori; Caudron, Fabrice; Denoth-Lippuner, Annina; Boettcher, Barbara; Buvelot Frei, Stéphanie; Snapp, Erik Lee; Barral, Yves

2014-01-01

In many cell types, lateral diffusion barriers compartmentalize the plasma membrane and, at least in budding yeast, the endoplasmic reticulum (ER). However, the molecular nature of these barriers, their mode of action and their cellular functions are unclear. Here, we show that misfolded proteins of the ER remain confined into the mother compartment of budding yeast cells. Confinement required the formation of a lateral diffusion barrier in the form of a distinct domain of the ER-membrane at the bud neck, in a septin-, Bud1 GTPase- and sphingolipid-dependent manner. The sphingolipids, but not Bud1, also contributed to barrier formation in the outer membrane of the dividing nucleus. Barrier-dependent confinement of ER stress into the mother cell promoted aging. Together, our data clarify the physical nature of lateral diffusion barriers in the ER and establish the role of such barriers in the asymmetric segregation of proteotoxic misfolded proteins during cell division and aging. DOI: http://dx.doi.org/10.7554/eLife.01883.001 PMID:24843009

Triaxial behaviour of a micro-concrete complete stress-strain curves for confining pressures ranging from 0 to 100 MPa

International Nuclear Information System (INIS)

Jamet, P.; Millard, A.; Nahas, G.

1984-05-01

A series of triaxial tests has been performed on micro-concrete cylinders. The specimens have been strained with a constant displacement rate, up to a deformation of about 10%. Two different domains were distinguihed. For low confining pressures strain softening is observed, the behaviour of the material becomes ductile for high confining pressures. Continuous measurement of the volume of fluid which had to be injected or withdrawn from the cell, to keep the confining pressure constant during the test, allowed to obtain data, concerning the overall lateral deformations of the specimens. Some specimens were also subjected to successive loadings with different confining pressures, in order to study the influence of stress path

Electromagnetic effects on the NET first wall caused by a plasma disruption event

International Nuclear Information System (INIS)

Crutzen, Y.R.; Biggio, M.; Farfaletti-Casali, F.

1987-01-01

During the event of a major plasma disruption, the structural components of the NET fusion reactor, such as the First Wall (FW), are subjected to strong electromagnetic transients arising from the interaction of the induced eddy currents with the large magnetic field which confines and equilibrates the plasma ring. Finite element structural analyses (static, vibration, transient dynamic) have been performed to examine stresses, deformations and reactions, generated by the electromagnetic loads, in the modular blanket-enveloping box outboard FW segment. Considering the last three engineering design variations of the outboard FW module, an improvement is obtained for the new Double Null FW configuration because of the drastic reduction of electromagnetic effects and induced stresses, mainly due to increased segmentation of the internal components

Stress of Rescue Team Members Working in Confined Spaces During a Disaster : Effectiveness of Individual Wireless Communication Devices

OpenAIRE

Kitabayashi, Tsukasa; Kudo, Seiko; Kitajima, Maiko; Takamaki, Shizuka; Chiba, Tomohiro; Tachioka, Nobuaki; Kudo, Shungetsu; Kudo, Hiromi

2016-01-01

This study evaluated stress experienced by rescue team members during a simulated search and rescue operation in a confined space and determine if wireless communication reduces stress. A total of 57 rescue team members of X prefecture participated. The stress visualization indices were ptyalin （i.e., salivary amylase）, salivary cortisol, autonomic nervous system response, visual analog scale, and a short version of the profile of mood states. The subjects were randomized to perform a simulat...

Influence of oxidative stress onto fibrin net formation, architecture and lysis

Czech Academy of Sciences Publication Activity Database

Štikarová, J.; Kotlín, R.; Suttnar, J.; Riedel, T.; Šácha, Pavel; Májek, P.; Chrastinová, L.; Hlaváčková, A.; Dyr, J. E.

2015-01-01

Roč. 13, Suppl 2 (2015), s. 837-838 ISSN 1538-7933. [ISTH 2015. Congress of the International Society on Thrombosis and Haemostasis /25./ and Annual SSC Meeting /61./. 20.06.2015-25.06.2015, Toronto] Grant - others:GA ČR(CZ) GBP205/12/G118; OPPK(CZ) CZ.2.16/3.1.00/24001 Program:GB Institutional support: RVO:61388963 Keywords : fibrinogen modification * fibrin net * oxidative stress Subject RIV: CE - Biochemistry

History of Solitary Confinement Is Associated with Post-Traumatic Stress Disorder Symptoms among Individuals Recently Released from Prison.

Science.gov (United States)

Hagan, Brian O; Wang, Emily A; Aminawung, Jenerius A; Albizu-Garcia, Carmen E; Zaller, Nickolas; Nyamu, Sylviah; Shavit, Shira; Deluca, Joseph; Fox, Aaron D

2018-04-01

This study assessed the relationship between solitary confinement and post-traumatic stress disorder (PTSD) symptoms in a cohort of recently released former prisoners. The cross-sectional design utilized baseline data from the Transitions Clinic Network, a multi-site prospective longitudinal cohort study of post-incarceration medical care. Our main independent variable was self-reported solitary confinement during the participants' most recent incarceration; the dependent variable was the presence of PTSD symptoms determined by primary care (PC)-PTSD screening when participants initiated primary care in the community. We used multivariable logistic regression to adjust for potential confounders, such as prior mental health conditions, age, and gender. Among 119 participants, 43% had a history of solitary confinement and 28% screened positive for PTSD symptoms. Those who reported a history of solitary confinement were more likely to report PTSD symptoms than those without solitary confinement (43 vs. 16%, p history of solitary confinement (OR = 3.93, 95% CI 1.57-9.83) and chronic mental health conditions (OR = 4.04, 95% CI 1.52-10.68) were significantly associated with a positive PTSD screen after adjustment for the potential confounders. Experiencing solitary confinement was significantly associated with PTSD symptoms among individuals accessing primary care following release from prison. Larger studies should confirm these findings.

An overview of the NeT international round-robin programme: weld residual stress measurement and modelling in nuclear materials

International Nuclear Information System (INIS)

Reid, M.H.; Hamelin, C.J.

2016-01-01

This talk provides an overview of the European Network on Neutron Techniques Standardisation for Structural Integrity (NeT). The network involves some 35 organisations from industry and academia, whose goal is to identify best practice in the application of modern experimental and numerical techniques to problems related to the structural integrity of components, mainly relevant to nuclear applications. While the programme was originally built around neutron scattering techniques for residual stress measurement, it has grown considerably to include studies of X-ray diffraction, deep-hole drilling, the contour method and other measurement techniques. Significant efforts have also been made within NeT to understand and predict weld residual stresses, often employing commercially available finite element (FE) codes. Several Task Groups have been developed to address unique challenges found in nuclear applications, from stress development in multi-pass AISI 316LN austenitic steel welds to the effects of solid-state phase transformation on residual stress development in SA508 ferritic steel, which is often used for reactor pressure vessel (RPV) construction. Some current and future work performed under the auspices of NeT are provided, with a focus on work Conducted at ANSTO. The aim is to give the audience a comprehensive overview of the work undertaken in NeT, and to shed some light on the potential present in this kind of collaborative effort. (author)

Effects of Predamaged Level on Confined HSC Columns

Directory of Open Access Journals (Sweden)

Ma Chau-Khun

2017-01-01

Full Text Available In the design of repair works for damaged concrete, an accurate and representative stress-strain model is of important. The stress-strain model for damaged high strength concrete (HSC repaired with post-tensioning steel straps confinement yet available, although the confining method has been proven to be effective in improving the performance of non-damaged HSC. A series of experimental test was carried out to investigate the stress-strain relationships of such concrete. A total of 24 HSC cylinders were compressed until certain damaged levels, then repaired by using steel straps. Two important parameters have been identified to have significant effects on the stress-strain relationship of such repaired concrete, namely the confining volumetric ratio and damaged levels. These parameters were incorporated into the development of stressstrain model, which later was shown to correlate well with the experimental results. This paper also has evidenced that existing stressstrain models of damaged concrete are not suitable to be directly applied to the design of repair works using post-tensioning steel straps confinement that produce external lateral stress on damaged columns before subsequent loading applied.

Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D

Energy Technology Data Exchange (ETDEWEB)

Burrell, K. H.; Chen, X.; Garofalo, A. M.; Groebner, R. J.; Muscatello, C. M.; Osborne, T. H.; Petty, C. C.; Snyder, P. B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Barada, K.; Rhodes, T. L.; Zeng, L. [University of California-Los Angeles, Los Angeles, California 90024 (United States); Solomon, W. M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Yan, Z. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2016-05-15

Recent experiments in DIII-D [J. L. Luxon et al., in Plasma Physics and Controlled Nuclear Fusion Research 1996 (International Atomic Energy Agency, Vienna, 1987), Vol. I, p. 159] have led to the discovery of a means of modifying edge turbulence to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no net external torque input. Eliminating the ELM-induced heat bursts and controlling plasma stability at low rotation represent two of the great challenges for fusion energy. By exploiting edge turbulence in a novel manner, we achieved excellent tokamak performance, well above the H{sub 98y2} international tokamak energy confinement scaling (H{sub 98y2} = 1.25), thus meeting an additional confinement challenge that is usually difficult at low torque. The new regime is triggered in double null plasmas by ramping the injected torque to zero and then maintaining it there. This lowers E × B rotation shear in the plasma edge, allowing low-k, broadband, electromagnetic turbulence to increase. In the H-mode edge, a narrow transport barrier usually grows until MHD instability (a peeling ballooning mode) leads to the ELM heat burst. However, the increased turbulence reduces the pressure gradient, allowing the development of a broader and thus higher transport barrier. A 60% increase in pedestal pressure and 40% increase in energy confinement result. An increase in the E × B shearing rate inside of the edge pedestal is a key factor in the confinement increase. Strong double-null plasma shaping raises the threshold for the ELM instability, allowing the plasma to reach a transport-limited state near but below the explosive ELM stability boundary. The resulting plasmas have burning-plasma-relevant β{sub N} = 1.6–1.8 and run without the need for extra torque from 3D magnetic fields. To date, stationary conditions have been produced for 2 s or 12 energy confinement times, limited only by external hardware constraints

Plasma cortisol and metabolite level profiles in two isogenic strains of common carp during confinement

NARCIS (Netherlands)

Ruane, N.M.; Huisman, E.A.; Komen, J.

2001-01-01

A rapid increase in common carp Cyprinus carpio plasma cortisol levels was noted, in two experiments, after 30 mins of a 3 h net confinement, which was sustained while the fish were held in the nets. After release from the nets, cortisol levels returned to control values in 1 h. Plasma glucose and

Elastic stress transmission and transformation (ESTT) by confined liquid: A new mechanics for fracture in elastic lithosphere of the earth

Science.gov (United States)

Xu, Xing-Wang; Peters, Stephen; Liang, Guang-He; Zhang, Bao-Lin

2016-01-01

We report on a new mechanical principle, which suggests that a confined liquid in the elastic lithosphere has the potential to transmit a maximum applied compressive stress. This stress can be transmitted to the internal contacts between rock and liquid and would then be transformed into a normal compressive stress with tangential tensile stress components. During this process, both effective compressive normal stress and tensile tangential stresses arise along the liquid–rock contact. The minimum effective tensile tangential stress causes the surrounding rock to rupture. Liquid-driven fracture initiates at the point along the rock–liquid boundary where the maximum compressive stress is applied and propagates along a plane that is perpendicular to the minimum effective tensile tangential stress and also is perpendicular to the minimum principal stress.

FRP confined smart concrete/mortar

Science.gov (United States)

Xiao, Y.; Zhu, P. S.; Choi, K. G.; Wu, Y. T.; Huang, Z. Y.; Shan, B.

2006-03-01

In this study, fiber reinforced polymer (FRP) confined smart concrete/mortar sensors were invented and validated for significantly improved measurement range. Several trial mixes were made using cement mortar and micron-phase graphite powders at different mix proportions. Compressive loading tests were conducted on smart mortar cylinder specimens with or without FRP confinement. Two-probe method was used to detect the electrical resistance of the smart cement mortar specimens. Strong correlation was recognized between the stress and electric resistance of the smart mortar. The test results indicated that the FRP wrapping could significantly enlarge the range of such self-sensing property as a consequence of confinement.

Power requirements for superior H-mode confinement on Alcator C-Mod: experiments in support of ITER

International Nuclear Information System (INIS)

Hughes, J.W.; Reinke, M.L.; Terry, J.L.; Brunner, D.; Greenwald, M.; Hubbard, A.E.; LaBombard, B.; Lipschultz, B.; Ma, Y.; Wolfe, S.; Wukitch, S.J.; Loarte, A.

2011-01-01

Power requirements for maintaining sufficiently high confinement (i.e. normalized energy confinement time H 98 ≥ 1) in H-mode and its relation to H-mode threshold power scaling, P th , are of critical importance to ITER. In order to better characterize these power requirements, recent experiments on the Alcator C-Mod tokamak have investigated H-mode properties, including the edge pedestal and global confinement, over a range of input powers near and above P th . In addition, we have examined the compatibility of impurity seeding with high performance operation, and the influence of plasma radiation and its spatial distribution on performance. Experiments were performed at 5.4 T at ITER relevant densities, utilizing bulk metal plasma facing surfaces and an ion cyclotron range of frequency waves for auxiliary heating. Input power was scanned both in stationary enhanced D α (EDA) H-modes with no large edge localized modes (ELMs) and in ELMy H-modes in order to relate the resulting pedestal and confinement to the amount of power flowing into the scrape-off layer, P net , and also to the divertor targets. In both EDA and ELMy H-mode, energy confinement is generally good, with H 98 near unity. As P net is reduced to levels approaching that in L-mode, pedestal temperature diminishes significantly and normalized confinement time drops. By seeding with low-Z impurities, such as Ne and N 2 , high total radiated power fractions are possible, along with substantial reductions in divertor heat flux (>4x), all while maintaining H 98 ∼ 1. When the power radiated from the confined versus unconfined plasma is examined, pedestal and confinement properties are clearly seen to be an increasing function of P net , helping to unify the results with those from unseeded H-modes. This provides increased confidence that the power flow across the separatrix is the correct physics basis for ITER extrapolation. The experiments show that P net /P th of one or greater is likely to lead to H

Holographic (de)confinement transitions in cosmological backgrounds

International Nuclear Information System (INIS)

Erdmenger, Johanna; Ghoroku, Kazuo; Meyer, Rene

2011-01-01

For type IIB supergravity with a running axio-dilaton, we construct bulk solutions which admit a cosmological background metric of Friedmann-Robertson-Walker type. These solutions include both a dark radiation term in the bulk as well as a four-dimensional (boundary) cosmological constant, while gravity at the boundary remains nondynamical. We holographically calculate the stress-energy tensor, showing that it consists of two contributions: The first one, generated by the dark radiation term, leads to the thermal fluid of N=4 SYM theory, while the second, the conformal anomaly, originates from the boundary cosmological constant. Conservation of the boundary stress-tensor implies that the boundary cosmological constant is time-independent, such that there is no exchange between the two stress-tensor contributions. We then study (de)confinement by evaluating the Wilson loop in these backgrounds. While the dark radiation term favors deconfinement, a negative cosmological constant drives the system into a confined phase. When both contributions are present, we find an oscillating universe with negative cosmological constant which undergoes periodic (de)confinement transitions as the scale of three-space expands and recontracts.

Experimental study of vertical stress profiles of a confined granular bed under static and dynamic conditions.

Science.gov (United States)

Mandato, S; Cuq, B; Ruiz, T

2012-07-01

In a wet agglomeration process inside a low shear mixer, the blade function is to induce i) homogenization of the liquid sprayed on the powder surface and ii) a stress field able to transfer the mechanical energy at the particle scale. In this work we study the mechanical state of a confined powder bed through the analysis of stress distributions (by force measurements) in a rectangular cell in two cases: for a classical model powder (i.e. glass beads) and a complex powder (i.e. wheat semolina). Two types of vertical stress profiles are obtained according to the type of measurements carried out in the powder bed, either locally (at different positions in the cell) or globally (at the entire base). The global vertical stress profile follows Janssen's model and the local vertical stress profile highlights a critical length, identified as the percolation threshold of the force network, and a shielding length near the bottom, which is similar to an influence length of the side walls. In the context of wet agglomeration, the results allow to consider the role of the characteristic lengths in the mixing bowl under vertical mechanical solicitation.

Shearing Nanometer-Thick Confined Hydrocarbon Films: Friction and Adhesion

DEFF Research Database (Denmark)

Sivebæk, I. M.; Persson, B. N. J.

2016-01-01

We present molecular dynamics (MD) friction and adhesion calculations for nanometer-thick confined hydrocarbon films with molecular lengths 20, 100 and 1400 carbon atoms. We study the dependency of the frictional shear stress on the confining pressure and sliding speed. We present results...

Effect of confinement and starvation on stress parameters in the American lobster (Homarus americanus

Directory of Open Access Journals (Sweden)

Edo D'Agaro

2014-12-01

Full Text Available The American lobster (Homarus americanus is one of the most important crustacean resources in North America. In Italy and Europe, this fishery product is available throughout the year and it has a high and increasing commercial demand. American lobsters are traditionally marketed live and stocked, without feed, in temperature controlled recirculating systems for several weeks before being sold in the market places. The current Italian legislation does not fix a maximum length of time for the crustacean confinement and specific welfare requirements. In the present research, a 4-week experiment was carried out using 42 adult H. americanus reared in 4 recirculating aquaculture tanks. After one month of confinement, mean glucose, protein and total haemocyte count levels in the hemolymph of H. americanus were stable and similar (P>0.05 to the values observed at the beginning of the experiment. Results of the proximate analysis of the abdominal muscles of H. americanus showed no significant differences in concentrations of crude protein, lipid and ash during the trial. At the end of the experiment, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analysis revealed a marked degradation of the muscle myofibrillar proteins. A number of fragments, possibly from myosin, were evident in the range between 50 and 220 kDa between time t0 and t28. Results of this study show that the main hemolymphatic variables and degradation analysis of the muscle myofibrillar proteins can be used as sensitive indicators of the crustacean stress response to confinement and starvation.

Linear and nonlinear characterization of low-stress high-confinement silicon-rich nitride waveguides.

Science.gov (United States)

Krückel, Clemens J; Fülöp, Attila; Klintberg, Thomas; Bengtsson, Jörgen; Andrekson, Peter A; Torres-Company, Víctor

2015-10-05

In this paper we introduce a low-stress silicon enriched nitride platform that has potential for nonlinear and highly integrated optics. The manufacturing process of this platform is CMOS compatible and the increased silicon content allows tensile stress reduction and crack free layer growth of 700 nm. Additional benefits of the silicon enriched nitride is a measured nonlinear Kerr coefficient n(2) of 1.4·10(-18) m(2)/W (5 times higher than stoichiometric silicon nitride) and a refractive index of 2.1 at 1550 nm that enables high optical field confinement allowing high intensity nonlinear optics and light guidance even with small bending radii. We analyze the waveguide loss (∼1 dB/cm) in a spectrally resolved fashion and include scattering loss simulations based on waveguide surface roughness measurements. Detailed simulations show the possibility for fine dispersion and nonlinear engineering. In nonlinear experiments we present continuous-wave wavelength conversion and demonstrate that the material does not show nonlinear absorption effects. Finally, we demonstrate microfabrication of resonators with high Q-factors (∼10(5)).

Space confinement and rotation stress induced self-organization of double-helix nanostructure: a nanotube twist with a moving catalyst head.

Science.gov (United States)

Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Huang, Jia-Qi; Wei, Fei

2012-05-22

Inorganic materials with double-helix structure have attracted intensive attention due to not only their elegant morphology but also their amazing morphology-related potential applications. The investigation on the formation mechanism of the inorganic double-helix nanostructure is the first step for the fundamental studies of their materials or physical properties. Herein, we demonstrated the space confinement and rotation stress induced self-organization mechanism of the carbon nanotube (CNT)-array double helices under scanning electron microscopy by directly observing their formation process from individual layered double hydroxide flakes, which is a kind of hydrotalcite-like material composed of positively charged layers and charge-balancing interlayer anions. Space confinement is considered to be the most important extrinsic factor for the formation of CNT-array double helices. Synchronous growth of the CNT arrays oppositely from LDH flakes with space confinement on both sides at the same time is essential for the growth of CNT-array double helices. Coiling of the as-grown CNT arrays into double helices will proceed by self-organization, tending to the most stable morphology in order to release their internal rotation stress. Based on the demonstrated mechanism, effective routes were carried out to improve the selectivity for CNT-array double helices. The work provides a promising method for the fabrication of double-helix nanostructures with their two helices connected at the end by self-assembly.

Helical Confinement Concepts

Energy Technology Data Exchange (ETDEWEB)

Beidler, C; Brakel, R; Burhenn, R; Dinklage, A; Erckmann, V; Feng, Y; Geiger, J; Hartmann, D; Hirsch, M; Jaenicke, R; Koenig, R; Laqua, H P; Maassberg, H; Wagner, F; Weller, A; Wobig, H [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, Greifswald (Germany)

2012-09-15

Stellarators, conceived 1951 by Lyman Spitzer in Princeton, are toroidal devices that confine a plasma in a magnetic field which originates from currents in coils outside the plasma. A plasma current driven by external means, for example by an ohmic transformer, is not required for confinement. Supplying the desired poloidal field component by external coils leads to a helically structured plasma topology. Thus stellarators - or helical confinement devices - are fully three-dimensional in contrast to the toroidal (rotational) symmetry of tokamaks. As stellarators can be free of an inductive current, whose radial distribution depends on the plasma parameters, their equilibrium must not be established via the evolving plasma itself, but to a first order already given by the vacuum magnetic field. They do not need an active control (like positional feedback) and therefore cannot suffer from its failure. The outstanding conceptual advantage of stellarators is the potential of steady state plasma operation without current drive. As there is no need for current drive, the recirculating power is expected to be smaller than in equivalent tokamaks. The lack of a net current avoids current driven instabilities; specifically, no disruptions, no resistive wall modes and no conventional or neoclassical tearing modes appear. Second order pressure-driven currents (Pfirsch-Schlueter, bootstrap) exist but they can be modified and even minimized by the magnetic design. The magnetic configuration of helical devices naturally possesses a separatrix, which allows the implementation of a helically structured divertor for exhaust and impurity control. (author)

Estimation of toroidal field coil stresses from magnetic loads in FER and NET using analytic methods and improved computer subroutine for TFC stress estimation in TRESCODE

International Nuclear Information System (INIS)

Riemer, B.W.; Miki, Nobuharu; Hashizume, Takashi.

1988-06-01

This report describes the comparison of TF coil stresses in NET and FER. The analyses focus on the straight part of the inner legs, since it is this part of the coil which most directly influences the radial build of the machine. NET's TF coils are wedged together and the centering force on each of the coils is reacted by toroidal compression of the inner legs. The forces that act out of the plane of each coil are reacted by friction between adjacent inner legs such that the set of legs behave much like a cylinder under torsion. In contrast, the FER device employs a bucking cylinder to react the centering load, which incurs a penalty in radial thickness, and the out of plane forces are reacted by the use of shear keys between adjacent inner legs. Analytic techniques or ''hand methods'' have been used to estimate and compare the strains and stresses at the inner leg mid-plane section resulting from both in-plane and out-of-plane magnetic forces. Such techniques forced a more thorough understanding of the structural behavior of the coils. The amount of effort in analyzing the NET coil is greater than for FER as the reaction of centering load in its wedged design is more complex, and because it was found that friction plays a very important part in determining the coil stresses. The FER coil is simpler in this regard, and a ''hand estimation'' of its coil stresses was straightfoward. In this report, the program written to perform these analyses is also described. It was desired to provide new capabilities to the original TF stress subroutine in TRESCODE and to review and improve it where possible. This has been accomplished, and subroutines are now available for use in JAERI's system code, TRESCODE. It is hoped that the inner leg radial thickness can be better optimized by using the program. (author)

Confined compressive strength model of rock for drilling optimization

Directory of Open Access Journals (Sweden)

Xiangchao Shi

2015-03-01

Full Text Available The confined compressive strength (CCS plays a vital role in drilling optimization. On the basis of Jizba's experimental results, a new CCS model considering the effects of the porosity and nonlinear characteristics with increasing confining pressure has been developed. Because the confining pressure plays a fundamental role in determining the CCS of bottom-hole rock and because the theory of Terzaghi's effective stress principle is founded upon soil mechanics, which is not suitable for calculating the confining pressure in rock mechanics, the double effective stress theory, which treats the porosity as a weighting factor of the formation pore pressure, is adopted in this study. The new CCS model combined with the mechanical specific energy equation is employed to optimize the drilling parameters in two practical wells located in Sichuan basin, China, and the calculated results show that they can be used to identify the inefficient drilling situations of underbalanced drilling (UBD and overbalanced drilling (OBD.

Frictional properties of confined polymers

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, Vladimir N; Persson, Bo N J

2008-01-01

We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively i...

Net carbon allocation in soybean seedlings as influenced by soil water stress at two soil temperatures

International Nuclear Information System (INIS)

McCoy, E.L.; Boersma, L.; Ekasingh, M.

1990-01-01

The influence of water stress at two soil temperatures on allocation of net photoassimilated carbon in soybean (Glycine max [L.] Merr.) was investigated using compartmental analysis. The experimental phase employed classical 14 C labeling methodology with plants equilibrated at soil water potentials of -0.04, -0.25 and -0.50 MPa; and soil temperatures of 25 and 10C. Carbon immobilization in the shoot apex generally followed leaf elongation rates with decreases in both parameters at increasing water stress at both soil temperatures. However, where moderate water stress resulted in dramatic declines in leaf elongation rates, carbon immobilization rates were sharply decreased only at severe water stress levels. Carbon immobilization was decreased in the roots and nodules of the nonwater stressed treatment by the lower soil temperature. This relation was reversed with severe water stress, and carbon immobilization in the roots and nodules was increased at the lower soil temperature. Apparently, the increased demand for growth and/or carbon storage in these tissues with increased water stress overcame the low soil temperature limitations. Both carbon pool sizes and partitioning of carbon to the sink tissues increased with moderate water stress at 25C soil temperature. Increased pool sizes were consistent with whole plant osmotic adjustment at moderate water stress. Increased partitioning to the sinks was consistent with carbon translocation processes being less severely influenced by water stress than is photosynthesis

Neutron diffraction study of internal stresses in brazed CFC/Mo divertor structures for NET/ITER

Energy Technology Data Exchange (ETDEWEB)

Ceretti, M [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France); Coppola, R [ENEA/Casaccia, INN-FIS, C.P. 2400, I-00100 Rome (Italy); Di Pietro, E [ENEA/Frascati, Dip. FUS, C.P. 2400, I-00100 Rome (Italy); Lodini, A [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France) Universite de Champagne-Ardennes, Reims (France); Perrin, M [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France); Piant, A [Laboratoire Leon-Brillouin, CEA/CE Saclay, F-91191, Gif-sur-Yvette (France); Rustichelli, F [Istituto di Scienze Fisiche, Universita di Ancona (Italy)

1994-09-01

This contribution presents the first results of a study, performed by neutron diffraction, on the internal stresses remaining after brazing at 860 C in graphite/molybdenum samples developed for NET/ITER. Samples of polycrystalline graphite and a carbon-fiber composite are considered. The deformation field is characterized close to the brazing interface, within a linear spatial resolution of approximately 2 mm. The results are discussed with reference to those obtainable by other methods and to theoretical considerations. ((orig.))

Leaf water relations and net gas exchange responses of salinized Carrizo citrange seedlings during drought stress and recovery.

Science.gov (United States)

Pérez-Pérez, J G; Syvertsen, J P; Botía, P; García-Sánchez, F

2007-08-01

Since salinity and drought stress can occur together, an assessment was made of their interacting effects on leaf water relations, osmotic adjustment and net gas exchange in seedlings of the relatively chloride-sensitive Carrizo citrange, Citrus sinensis x Poncirus trifoliata. Plants were fertilized with nutrient solution with or without additional 100 mm NaCl (salt and no-salt treatments). After 7 d, half of the plants were drought stressed by withholding irrigation water for 10 d. Thus, there were four treatments: salinized and non-salinized plants under drought-stress or well-watered conditions. After the drought period, plants from all stressed treatments were re-watered with nutrient solution without salt for 8 d to study recovery. Leaf water relations, gas exchange parameters, chlorophyll fluorescence, proline, quaternary ammonium compounds and leaf and root concentrations of Cl(-) and Na(+) were measured. Salinity increased leaf Cl(-) and Na(+) concentrations and decreased osmotic potential (Psi(pi)) such that leaf relative water content (RWC) was maintained during drought stress. However, in non-salinized drought-stressed plants, osmotic adjustment did not occur and RWC decreased. The salinity-induced osmotic adjustment was not related to any accumulation of proline, quaternary ammonium compounds or soluble sugars. Net CO(2) assimilation rate (A(CO2)) was reduced in leaves from all stressed treatments but the mechanisms were different. In non-salinized drought-stressed plants, lower A(CO2) was related to low RWC, whereas in salinized plants decreased A(CO2) was related to high levels of leaf Cl(-) and Na(+). A(CO2) recovered after irrigation in all the treatments except in previously salinized drought-stressed leaves which had lower RWC and less chlorophyll but maintained high levels of Cl(-), Na(+) and quaternary ammonium compounds after recovery. High leaf levels of Cl(-) and Na(+) after recovery apparently came from the roots. Plants preconditioned by

Effect of stress during handling, seawater acclimation, confinement, and induced spawning on plasma ion levels and somatolactin-expressing cells in mature female Liza ramada.

Science.gov (United States)

Khalil, Noha A; Hashem, Amal M; Ibrahim, Amal A E; Mousa, Mostafa A

2012-08-01

The present experiments were designed to determine the effect of different stress factors; handling, seawater acclimation, confinement, and induced spawning on plasma cortisol, hydro mineral balance as well as changes in size, number and integrated intensity of somatolactin (SL)-expressing cells in Liza ramada mature females confined to fresh water ponds. The plasma levels of cortisol, PO(4)(3-), Na(+), and K(+) were higher, while Ca(2+) and Mg(2+) were lower than controls during transportation without anesthesia. By using clove oil (5 mg L(-1)) as an anesthetic during transportation, the plasma cortisol, PO(4) (3-), Na(+), and K(+) were similar to controls, while Ca(2+) and Mg(2+) were higher. During seawater acclimation, the plasma cortisol and minerals were significantly higher except Na(+) which was lower than controls. In addition, during induction of spawning, the plasma levels of cortisol, PO(4)(3-), Na(+), K(+), and Mg(2+) were significantly higher than controls. The SL-producing cells are located in the pars intermedia (PI) bordering the neurohypophysis. The stress affected the number, size, and immunostaining of SL-expressing cells. During seawater acclimation, the size and the integrated intensity of SL immunoreactivity were lower, but the number of these cells was higher than controls. Furthermore, the number, size, and the integrated intensity of SL immunoreactivity were significantly lower than controls during handling and after spawning, which was opposite to confinement. The response of SL-expressing cells in PI in parallel with changes in cortisol and hydro mineral balance induced by stress support the possible role of SL in the adaptive response of fish to stress. © 2012 WILEY PERIODICALS, INC.

GEM2Net: from gene expression modeling to -omics networks, a new CATdb module to investigate Arabidopsis thaliana genes involved in stress response.

Science.gov (United States)

Zaag, Rim; Tamby, Jean Philippe; Guichard, Cécile; Tariq, Zakia; Rigaill, Guillem; Delannoy, Etienne; Renou, Jean-Pierre; Balzergue, Sandrine; Mary-Huard, Tristan; Aubourg, Sébastien; Martin-Magniette, Marie-Laure; Brunaud, Véronique

2015-01-01

CATdb (http://urgv.evry.inra.fr/CATdb) is a database providing a public access to a large collection of transcriptomic data, mainly for Arabidopsis but also for other plants. This resource has the rare advantage to contain several thousands of microarray experiments obtained with the same technical protocol and analyzed by the same statistical pipelines. In this paper, we present GEM2Net, a new module of CATdb that takes advantage of this homogeneous dataset to mine co-expression units and decipher Arabidopsis gene functions. GEM2Net explores 387 stress conditions organized into 18 biotic and abiotic stress categories. For each one, a model-based clustering is applied on expression differences to identify clusters of co-expressed genes. To characterize functions associated with these clusters, various resources are analyzed and integrated: Gene Ontology, subcellular localization of proteins, Hormone Families, Transcription Factor Families and a refined stress-related gene list associated to publications. Exploiting protein-protein interactions and transcription factors-targets interactions enables to display gene networks. GEM2Net presents the analysis of the 18 stress categories, in which 17,264 genes are involved and organized within 681 co-expression clusters. The meta-data analyses were stored and organized to compose a dynamic Web resource. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

The conservatism of the net-section stress procedure for predicting the failure of cracked piping systems: The effect of crack location on the degree of conservatism

International Nuclear Information System (INIS)

Smith, E.

1993-01-01

Interest in the integrity of cracked piping systems fabricated from ductile materials has been motivated, in large part, by the technological problem of intergranular stress corrosion cracking of Type 304 stainless steel piping in boiling water nuclear reactor piping systems. The failure of cracked steel piping is often predicted by assuming that failure conforms to a net-section stress criterion using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stresses at the cracked section are usually calculated via a purely elastic analysis based on the piping being uncracked. However because the piping is built-in at the ends into a larger component, and since the onset of crack extension requires some plastic deformation, use of the net-section stress approach can give overly conservative failure predictions. An earlier paper has quantified the extent of this conservatism, and has shown how it depends on the material ductility and the elastic flexibility of a piping system. Using the results of analyses for simple model systems, the present paper shows that, for the same cracked section geometry, the degree of conservatism is markedly influenced by the location of the cracked section within the system

High-Energy Electron Confinement in a Magnetic Cusp Configuration

Directory of Open Access Journals (Sweden)

Jaeyoung Park

2015-06-01

Full Text Available We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when β (plasma pressure/magnetic field pressure is of order unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high β a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. While not able to confirm the details of Grad’s work, the current experiment does validate, for the first time, the conjecture that confinement is substantially improved at high β. This represents critical progress toward an understanding of the plasma dynamics in a high-β cusp system. We hope that these results will stimulate a renewed interest in the cusp configuration as a fusion confinement candidate. In addition, the enhanced high-energy electron confinement resolves a key impediment to progress of the Polywell fusion concept, which combines a high-β cusp configuration with electrostatic fusion for a compact, power-producing nuclear fusion reactor.

Impact of confinement physics on reactor design and economics

International Nuclear Information System (INIS)

DeFreece, D.A.; Campbell, R.B.; Waganer, L.M.

1977-01-01

A variety of confinement laws were employed in a transient, zero dimensional plasma code, which was coupled to the TOCOMO systems code. The purpose was to determine the impact of the confinement laws on reactor design, power costs and changes in the utility interface. A satisfactory reactor and power plant has been defined for the large majority of combinations of confinement law, power plant size and plasma shape. Trapped ion mode (TIM) has been the easiest to work with, since the plasma is thermally stable with a good power density and minimal alpha particle build up. Neoclassical and pseudoclassical along with TEMII result in satisfactory reactor performance, but require active feedback control (by injecting impurities) to prevent plasma temperature excursions. These laws also require some form and degree of confinement time spoiling to allow long burn times, otherwise, alpha particles build up to an unacceptable level. TEM I results in thermal equilibrium at 5 keV and must be driven to provide a reactor quality plasma. The continuous injected power required for a 4300 MW thermal reactor is 540 MW. This added to the other circulating loads results in a net power output of 600 MWe at a very high relative cost. Daughney (empirical) confinement results in a satisfactory, competitive reactor

Effect of laser peening with glycerol as plasma confinement layer

Science.gov (United States)

Tsuyama, Miho; Ehara, Naoya; Yamashita, Kazuma; Heya, Manabu; Nakano, Hitoshi

2018-03-01

The effects of controlling the plasma confinement layer on laser peening were investigated by measuring the hardness and residual stress of laser-peened stainless steels. The plasma confinement layer contributes to increasing the pressure of shock waves by suppressing the expansion of the laser-produced plasma. Most previous studies on laser peening have employed water as the plasma confinement layer. In this study, a glycerol solution is used in the context of a large acoustic impedance. It is found that this glycerol solution is superior to water in its ability to confine plasma and that suitable conditions exist for the glycerol solution to act as a plasma confinement layer to achieve efficient laser peening.

The causal role of fatigue in the stress-perceived health relationship: a MetroNet study.

Science.gov (United States)

Maghout-Juratli, Sham; Janisse, James; Schwartz, Kendra; Arnetz, Bengt B

2010-01-01

We conducted a cross-sectional survey of 4 primary care MetroNet centers in metropolitan Detroit. Our objective was to describe the causal role of fatigue in the relationship among stress, stress resiliency, and perceived health in primary care. Fatigue is a public health problem that has been linked to stress and poor health. The causal role of fatigue between stress and perceived health is unknown. Four hundred surveys were distributed to adult patients in 4 primary care centers in metropolitan Detroit between 2006 and 2007. Internal consistency reliabilities and principal factor analyses were calculated for the key psychological scales. Perceived health is the primary outcome. Path models were used to study the relationship among stress, fatigue, and perceived health. We also modeled the impact of select stress resiliency factors including sleep, recovery, and social support. Of the 400 distributed surveys, 315 (78.7%) had a response rate of 70% or more and were included in the analysis. Respondents were predominantly middle aged (median age, 43 years); female (58.7%); and African American (52.0%). The majority worked full time (56.5%); did not have a college degree (77.7%); and were not married (55.2%). Fatigue was reported by 59% of respondents, 42.7% of which was unexplained. The path model supported the causal role of fatigue between stress and perceived health. The positive effects of sleep, recovery, and social support on fatigue, stress, and perceived health were validated. Fatigue was common in this metropolitan primary care environment and completely mediated the relationship between stress and poor perceived health. Therefore, stress, when significant enough to cause fatigue, may lead to poor health.

Laboratory Investigation to Assess the Impact of Pore Pressure Decline and Confining Stress on Shale Gas Reservoirs

Directory of Open Access Journals (Sweden)

khalil Rehman Memon

2018-01-01

Full Text Available Four core samples of outcrop type shale from Mancos, Marcellus, Eagle Ford, and Barnett shale formations were studied to evaluate the productivity performance and reservoir connectivity at elevated temperature and pressure. These laboratory experiments were conducted using hydrostatic permeability system with helium as test gas primarily to avoid potential significant effects of adsorption and/or associated swelling that might affect permeability. It was found that the permeability reduction was observed due to increasing confining stress and permeability improvement was observed related to Knudsen flow and molecular slippage related to Klinkenberg effect. Through the effective permeability of rock is improved at lower pore pressures, as 1000 psi. The effective stress with relatively high flow path was identified, as 100-200 nm, in Eagle Ford core sample. However other three samples showed low marginal flow paths in low connectivity.

Masonry Columns Confined by Steel Fiber Composite Wraps

Directory of Open Access Journals (Sweden)

Marco Corradi

2011-01-01

Full Text Available The application of steel fiber reinforced polymer (SRP as a means of increasing the capacity of masonry columns is investigated in this study. The behavior of 23 solid-brick specimens that are externally wrapped by SRP sheets in low volumetric ratios is presented. The specimens are subjected to axial monotonic load until failure occurs. Two widely used types of masonry columns of differing square cross-sections were tested in compression (square and octagonal cross-sections. It is concluded that SRP-confined masonry behaves very much like fiber reinforced polymers (FRP-confined masonry. Confinement increases both the load-carrying capacity and the deformability of masonry almost linearly with average confining stress. A comparative analysis between experimental and theoretical values computed in compliance with the Italian Council of Research (CNR was also developed.

The conservatism of the net-section stress procedure for predicting the failure of cracked piping systems: the effect of crack shape complexity on the degree of conservatism

International Nuclear Information System (INIS)

Smith, E.

1996-01-01

The failure of circumferentially cracked steel piping is often predicted by assuming that failure conforms to a net-section stress criterion using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stress at the cracked section is usually calculated via a purely elastic analysis based on the piping being uncracked. however, because the piping is built-in at the ends into a larger component, and since the onset of crack extension requires some plastic deformation, use of the net-section stress approach can give overly conservative failure predictions. In earlier work, the author has quantified the extent of this conservatism, and has shown how it depends on the geometry of the cracked section, the material ductility and the elastic flexibility of a piping system. This paper quantifies the conservatism with regard to the case where a through-wall crack extends over a prescribed fraction of the pipe circumference, while there is also an internal circumferential crack extending around the remainder of the pipe section. This is an extreme form of circumferential cracking but nevertheless, simulates the well-known Duane Arnold safe-end crack. (Author)

Magnetic confinement fusion plasma theory, Task 1

International Nuclear Information System (INIS)

Callen, J.D.

1991-07-01

The research performed under this grant during the current year has concentrated on a few key tokamak plasma confinement and heating theory issues: extensive development of a new Chapman-Enskog-like fluid/kinetic hybrid approach to deriving rigorously valid fluid moment equations; applications (neoclassical viscous force, instabilities in the banana-plateau collisionality regime, nonlinear gyroviscous force, unified plasma microinstability equations and their implications, semi-collisional presheath modeling, etc.) of this new formalism; interactions of fluctuating bootstrap-current-driven magnetic islands; determination of net transport processes and equations for a tokamak; and some other topics (extracting more information from heat-pulse-propagation data, modeling of BES fluctuation data, exploring sawtooth effects on energy confinement in DIII-D, divertor X-point modeling). Recent progress and publications in these areas, and in the management of the local NERSC node and fusion theory DECstation 5000 at UW-Madison are summarized briefly in this report

SAFIRE: A systems analysis code for ICF [inertial confinement fusion] reactor economics

International Nuclear Information System (INIS)

McCarville, T.J.; Meier, W.R.; Carson, C.F.; Glasgow, B.B.

1987-01-01

The SAFIRE (Systems Analysis for ICF Reactor Economics) code incorporates analytical models for scaling the cost and performance of several inertial confinement fusion reactor concepts for electric power. The code allows us to vary design parameters (e.g., driver energy, chamber pulse rate, net electric power) and evaluate the resulting change in capital cost of power plant and the busbar cost of electricity. The SAFIRE code can be used to identify the most attractive operating space and to identify those design parameters with the greatest leverage for improving the economics of inertial confinement fusion electric power plants

Confinement of Stellarator plasmas with neutral beam and RF heating in W VII-A

International Nuclear Information System (INIS)

Grieger, G.; Cattanei, G.; Dorst, D.

1986-01-01

WENDELSTEIN VII-A has been operated for ten years. It is a low-shear, high-aspect-ratio device. The confinement properties have been thoroughly studied for both ohmically heated and net-current free plasmas. For the latter case, NBI- and ECF-maintained plasmas were of particular importance. It was found that under optimized conditions the core of high-pressure, net-current free plasmas is mainly governed by collisional effects. The experiment will now be shut down for upgrading it into the Advanced Stellarator WEDNDELSTEIN VII-AS. (author)

Velocity Dependence of Friction of Confined Hydrocarbons

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

2010-01-01

We present molecular dynamics friction calculations for confined hydrocarbon “polymer” solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate and (b) polymer sliding on polymer. We discuss the velocity dependence of the f......We present molecular dynamics friction calculations for confined hydrocarbon “polymer” solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate and (b) polymer sliding on polymer. We discuss the velocity dependence...... of the frictional shear stress for both cases. In our simulations, the polymer films are very thin (∼3 nm), and the solid walls are connected to a thermostat at a short distance from the polymer slab. Under these circumstances we find that frictional heating effects are not important, and the effective temperature...... in the polymer film is always close to the thermostat temperature. In the first setup (a), for hydrocarbons with molecular lengths from 60 to 1400 carbon atoms, the shear stresses are nearly independent of molecular length, but for the shortest hydrocarbon C20H42 the frictional shear stress is lower. In all...

Spatial variation in tuber depletion by swans explained by differences in net intake rates

NARCIS (Netherlands)

Nolet, BA; Langevoord, O; Bevan, RM; Engelaar, KR; Klaassen, M; Mulder, RJW

We tested whether the spatial variation in resource depletion by Tundra Swans (Cygnus columbianus) foraging on belowground tubers of sage pondweed (Potnmogeton pectinatus) was caused by differences in net energy intake rates. The variation in giving up densities within the confines of one lake was

Strength curves for shales and sandstones under hydrostatic confining pressures

International Nuclear Information System (INIS)

Gupta, S.C.; Sikka, S.K.

1978-01-01

The experimental data for the effect of confining pressures on the fracture stress have been analysed for shales and sandstones. The normalized compressive strengths are found to lie in a narrow region so that Ohnaka's equation for crystalline rocks, can be fitted to the data. The fitted parameters are physically reasonable and indicate that the functional dependence of strength on porosity, strain rate and temperature is independent of the confining pressures. (author)

Prediction of transverse asymmetries in MHD ducts with zero net Hall current

International Nuclear Information System (INIS)

Swean, T.F. Jr.; Oliver, D.A.; Maxwell, C.D.; Demetriades, S.T.

1981-01-01

A new class of fluid-electrical asymmetries in MHD generator channel flow are predicted. It is shown that the existence of interelectrode asymmetries is not confined to generators in which there exists a nonzero net axial current, but rather they are induced even in the case of the Faraday generators. Also demonstrated is the impact of these asymmetries upon the generator and diffuser flow. It is concluded that in MHD generators, the net axial current in the cross plane is identically zero, while at any given point in the plane, the local Hall current density is in general nonzero

Shape and 'gap' effects on the behavior of variably confined concrete

International Nuclear Information System (INIS)

Harries, Kent A.; Carey, Shawn A.

2003-01-01

Factors affecting the behavior of variably confined concrete are presented. The effect of debonding the fiber-reinforced polymer (FRP) jacket to the concrete substrate and providing a gap between the concrete and confining jacket is investigated. A second parameter--the shape of the cross section--is also investigated. An experimental program involving the compression testing of standard cylinders and similarly sized square specimens having external FRP jackets providing passive confinement is presented. Factors affecting jacket efficiency and the appropriateness of factors accounting for specimen shape are determined experimentally and discussed. The provision of a gap affected the axial stress at which the confining jacket was engaged, resulting in a reduced maximum attainable concrete strength. The jacket efficiency was not affected by the provision of the gap. The shape of the specimens was observed to affect the level of confinement generated. Square specimens exhibit lower confinement levels than circular specimens having the same jacket

Lateral stress-induced propagation characteristics in photonic crystal fibres

Institute of Scientific and Technical Information of China (English)

Tian Hong-Da; Yu Zhong-Yuan; Han Li-Hong; Liu Yu-Min

2009-01-01

Using the finite element method, this paper investigates lateral stress-induced propagation characteristics in a pho-tonic crystal fibre of hexagonal symmetry. The results of simulation show the strong stress dependence of effective index of the fundamental guided mode, phase modal birefringence and confinement loss. It also finds that the contribution of the geometrical effect that is related only to deformation of the photonic crystal fibre and the stress-related contribution to phase modal birefringence and confinement loss are entirely different. Furthermore, polarization-dependent stress sensitivity of confinement loss is proposed in this paper.

Confinement of NORMAL- AND HIGH-STRENGTH CONCRETE by Shape Memory Alloy (SMA) Spirals

Science.gov (United States)

Gholampour, A.; Ozbakkaloglu, T.

2018-01-01

This paper presents the results of an experimental study on the axial compressive behaviour of normal- and high-strength concrete (NSC and HSC) confined by shape memory alloy (SMA) spirals. A spiral pitch space of 36 and 20 mm was used for SMA confinement of NSC and HSC columns, respectively. The confining pressure was applied on the concrete cylinders by SMA spirals that were prestrained at 0, 5.5, and 9.5%. The compression test results on the SMA-confined specimens indicate that the prestrain level of SMA significantly affects the axial compressive behaviour of both NSC and HSC. An increase in the level of prestrain leads to an increase in the peak axial stress and corresponding strain of SMA-confined concrete.

Monotonic and cyclic bond behavior of confined concrete using NiTiNb SMA wires

International Nuclear Information System (INIS)

Choi, Eunsoo; Chung, Young-Soo; Kim, Yeon-Wook; Kim, Joo-Woo

2011-01-01

This study conducts bond tests of reinforced concrete confined by shape memory alloy (SMA) wires which provide active and passive confinement of concrete. This study uses NiTiNb SMA which usually shows wide temperature hysteresis; this is a good advantage for the application of shape memory effects. The aims of this study are to investigate the behavior of SMA wire under residual stress and the performance of SMA wire jackets in improving bond behavior through monotonic-loading tests. This study also conducts cyclic bond tests and analyzes cyclic bond behavior. The use of SMA wire jackets transfers the bond failure from splitting to pull-out mode and satisfactorily increases bond strength and ductile behavior. The active confinement provided by the SMA plays a major role in providing external pressure on the concrete because the developed passive confinement is much smaller than the active confinement. For cyclic behavior, slip and circumferential strain are recovered more with larger bond stress. This recovery of slip and circumferential strain are mainly due to the external pressure of the SMA wires since cracked concrete cannot provide any elastic recovery

Effects of acute temperature change, confinement and housing on plasma corticosterone in water snakes, Nerodia sipedon (Colubridae: Natricinae).

Science.gov (United States)

Sykes, Kyle Lea; Klukowski, Matthew

2009-03-01

Body temperature affects many aspects of reptilian behavior and physiology, but its effect on hormonal secretion has been little studied, especially in snakes. Major objectives of this study were to determine if acute changes in body temperature during confinement influenced plasma corticosterone levels and if initial body temperatures upon capture in the field were related to baseline corticosterone levels in water snakes (Nerodia sipedon). Water snakes were bled upon capture in the field and after one hour of confinement in a cooled, control, or heated incubator. Since little is known about the potential metabolic changes in response to stress in reptiles, plasma triglyceride levels were also measured. Upon completion of the field study, snakes were housed for 5-8 days without food to determine the effect of chronic stress on both corticosterone and triglyceride levels. Plasma corticosterone concentrations were measured using enzyme-linked immunosorbant assay (ELISA) and plasma triglycerides were determined enzymatically. In the field, experimental alterations of body temperature during confinement had no effect on corticosterone levels. Similarly, there was no correlation between initial body temperature and baseline plasma corticosterone concentrations. However, post-confinement corticosterone levels were approximately three-times greater in females than males. Plasma triglyceride levels were not affected by temperature treatment, confinement, or sex. Compared to field values, both baseline and post-confinement corticosterone levels were elevated after the chronic stress of short-term laboratory housing but triglyceride levels decreased. Overall, these results indicate that sex but not body temperature has a major influence on the adrenocortical stress response in Nerodia sipedon.

A new and effective method for thermostatting confined fluids

DEFF Research Database (Denmark)

De Luca, Sergio; Billy, Todd; Hansen, Jesper Schmidt

2014-01-01

not interact with wall atoms or each other, thus behaving as virtual particles. Their displacements violate the Lindemann criterion for melting, in such a way that the net effect would not amount to an additional confining surface. One advantage over standard techniques is the reduced computational cost......, particularly for large walls, since they can be kept rigid. Another advantage over accepted strategies is the opportunity to freeze complex charged walls such as β-cristobalite. The method furthermore overcomes the problem with polar fluids such as water, as thermalized charged surfaces require higher spring...

Acute exposure to offshore produced water has an effect on stress- and secondary stress responses in three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Knag, Anne Christine; Taugbøl, Annette

2013-09-01

Pollution is one of today's greatest problems, and the release of contaminants into the environment can cause adverse changes in vitally important biological pathways. In this study, we exposed three-spined stickleback Gasterosteus aculeatus to produced water (PW), i.e. wastewater from offshore petroleum production. PW contains substances such as alkylphenols (APs) and aromatic hydrocarbons (PAHs) known to induce toxicant stress and endocrine disruption in a variety of organisms. Following exposure to PW, a standardized confinement treatment was applied as a second stressor (PW-stress), testing how fish already under stress from the pollutant would respond to an additional stressor. The endpoint for analysis was a combination of blood levels of cortisol and glucose, in addition to transcribed levels of a set of genes related to toxicant stress, endocrine disruption and general stress. The findings of this study indicate that low doses of PW do not induce vitellogenin in immature female stickleback, but do cause an upregulation of cytochrome (CYP1A) and UDP-glucuronsyltransferase (UDP-GT), two biomarkers related to toxicant stress. However, when the second stressor was applied, both genes were downregulated, indicating that the confinement exposure had a suppressive effect on the expression of toxicant biomarkers (CYP1A and UDP-GT). Further, two of the stress related genes, heat shock protein 90 (HSP90) and stress-induced phosphoprotein (STIP), were upregulated in both PW- and PW-stress-treatment, but not in the water control confinement treatment, indicating that PW posed as a larger stress-factor than confinement for these genes. The confinement stressor caused an increased level of glucose in both control and PW-treated fish, indicating hyperglycemia, a commonly reported stress response in fish. © 2013.

Confining pressure effects on stress intensity factors: A 3D finite ...

African Journals Online (AJOL)

. MRM Aliha, MR Ayatollahi, MMS Mousavi. Abstract. At great depths of earth, fracture in rock masses occurs under the influence of confining pressure. However, most of the previous rock fracture studies deal only with ambient conditions and ...

Structural and mechanical properties of glassy water in nanoscale confinement.

Science.gov (United States)

Lombardo, Thomas G; Giovambattista, Nicolás; Debenedetti, Pablo G

2009-01-01

We investigate the structure and mechanical properties of glassy water confined between silica-based surfaces with continuously tunable hydrophobicity and hydrophilicity by computing and analyzing minimum energy, mechanically stable configurations (inherent structures). The structured silica substrate imposes long-range order on the first layer of water molecules under hydrophobic confinement at high density (p > or = 1.0 g cm(-3)). This proximal layer is also structured in hydrophilic confinement at very low density (p approximately 0.4 g cm(-3)). The ordering of water next to the hydrophobic surface greatly enhances the mechanical strength of thin films (0.8 nm). This leads to a substantial stress anisotropy; the transverse strength of the film exceeds the normal strength by 500 MPa. The large transverse strength results in a minimum in the equation of state of the energy landscape that does not correspond to a mechanical instability, but represents disruption of the ordered layer of water next to the wall. In addition, we find that the mode of mechanical failure is dependent on the type of confinement. Under large lateral strain, water confined by hydrophilic surfaces preferentially forms voids in the middle of the film and fails cohesively. In contrast, water under hydrophobic confinement tends to form voids near the walls and fails by loss of adhesion.

Pulsed power systems for inertial confinement fusion

International Nuclear Information System (INIS)

VanDevender, J.P.

1979-01-01

Sandis's Particle Beam Fusion Program is investigating pulsed electron and light ion beam accelerators with the goal of demonstrating the practical application of such drivers as igniters in inertial confinement fusion (ICF) reactors. The power and energy requirements for net energy gain are 10 14 to 10 15 W and 1 to 10 MJ. Recent advances in pulsed power and power flow technologies permit suitable accelerators to be built. The first accelerator of this new generation is PBFA I. It operates at 2 MV, 15 MA, 30 TW for 35 ns and is scheduled for completion in June 1980. The principles of this new accelerator technology and their application to ICF will be presented

The quark-hadron transition in systems with net baryon number

International Nuclear Information System (INIS)

Olive, K.A.; Harvard Univ., Cambridge, MA

1982-01-01

The transition from quark matter to hadronic matter is examined in systems with arbitrary chemical potentials corresponding to net baryon number. In the hardron phase, both a Reid-type potential for nucleons and the ππ potential derived from Weinberg's effective lagrangian have been included. In the quark phase, a linear confining potential has been considered. Results are most sensitive to the slope of the confining potential, although qualitatively the behavior of the thermodynamic properties remain unchanged. The critical baryon density is found to remain roughly constant for all temperatures below the critical temperature, Tsub(c), then falls rapidly to zero as T → Tsub(c). Below Tsub(c) this density is about 30n 0 for K = 0.18 GeV 2 (the slope of the quark potential) and 23n 0 for K = 0.10 GeV 2 . (orig.)

Structure in a confined smectic liquid crystal with competing surface and sample elasticities

International Nuclear Information System (INIS)

Idziak, S.H.; Koltover, I.; Israelachvili, J.N.; Safinya, C.R.

1996-01-01

We report on studies using the x-ray surface forces apparatus (XSFA) to compare the structure of a liquid crystal confined between hard surfaces and, for the first time, between soft surfaces that can deform due to the stresses imposed by the confined fluid. We find that the alignment of smectic domains in confined films depends critically on both the shape and compliance of the confining walls or surfaces: open-quote open-quote Soft surfaces close-quote close-quote exhibit a critical gap thickness of 3.4 μm for the liquid crystal studied at which maximum alignment occurs, while open-quote open-quote hard surfaces close-quote close-quote do not exhibit gap-dependent alignment. copyright 1996 The American Physical Society

Shearing of saturated clays in rock joints at high confining pressures

International Nuclear Information System (INIS)

Wang, C.; Mao, N.

1979-01-01

Saturated clays are sheared between rock joints at various pore water pressures and at confining pressures up to 3 kb (300 Mpa). Sliding on these joints is stable. For a given clay, the shear stress required to initiate sliding increases linearly with the effective normal stress across the sliding surface, with a slope of 0.08 +- 0.01 for joints filled with saturated montmorillonite, 0.12 +- 0.01 with saturated chlorite, 0.15 +- 0.01 with saturated kaolinite, and 0.22 +- 0.02 with saturated silty illite. Thus at high confining pressures the shear stress required to initiate sliding on joints filled with saturated clays are very much smaller than that required to initiate sliding on clean rock joints or on joints filled with dry gouge materials. In the crust, saturation of gouge materials along active faults would greatly lower the frictional resistance to faulting and would stabilize fault movement. Different fault behaviors such as stable creep along some faults and intermittent but sudden slip along others may reflect in part different degrees of saturation of fault zones at depth

A gene expression signature of confinement in peripheral blood of red wolves (Canis rufus).

Science.gov (United States)

Kennerly, Erin; Ballmann, Anne; Martin, Stanton; Wolfinger, Russ; Gregory, Simon; Stoskopf, Michael; Gibson, Greg

2008-06-01

The stresses that animals experience as a result of modification of their ecological circumstances induce physiological changes that leave a signature in profiles of gene expression. We illustrate this concept in a comparison of free range and confined North American red wolves (Canis rufus). Transcription profiling of peripheral blood samples from 13 red wolf individuals in the Alligator River region of North Carolina revealed a strong signal of differentiation. Four hundred eighty-two out of 2980 transcripts detected on Illumina HumanRef8 oligonucleotide bead arrays were found to differentiate free range and confined wolves at a false discovery rate of 12.8% and P stress responses in confined animals. Consequently, characterization of differential transcript abundance in an accessible tissue such as peripheral blood identifies biomarkers that could be useful in animal management practices and for evaluating the impact of habitat changes on population health, particularly as attention turns to the impact of climate change on physiology and in turn species distributions.

Selection for stress responsiveness and slaughter stress affect flesh quality in pan-size rainbow trout, Oncorhynchus mykiss

OpenAIRE

Lefevre, Florence; Cos, Isabelle; Pottinger, Tom G.; Bugeon, Jérôme

2016-01-01

The control of slaughter stress is of importance with regard to both fish welfare and flesh quality. Muscle characteristics and instrumentally measured quality parameters were determined in rainbow trout lines selected for high-responsiveness (HR) or low-responsiveness (LR) of plasma cortisol to an acute confinement stressor. Measurements were made in both unstressed and stressed fish (a 15 min period of confinement before slaughter) from both lines. Compared to LR fish, HR fish were smaller,...

How Confinement-Induced Structures Alter the Contribution of Hydrodynamic and Short-Ranged Repulsion Forces to the Viscosity of Colloidal Suspensions

Directory of Open Access Journals (Sweden)

Meera Ramaswamy

2017-10-01

Full Text Available Confined systems ranging from the atomic to the granular are ubiquitous in nature. Experiments and simulations of such atomic and granular systems have shown a complex relationship between the microstructural arrangements under confinement, the short-ranged particle stresses, and flow fields. Understanding the same correlation between structure and rheology in the colloidal regime is important due to the significance of such suspensions in industrial applications. Moreover, colloidal suspensions exhibit a wide range of structures under confinement that could considerably modify such force balances and the resulting viscosity. Here, we use a combination of experiments and simulations to elucidate how confinement-induced structures alter the relative contributions of hydrodynamic and short-range repulsive forces to produce up to a tenfold change in the viscosity. In the experiments we use a custom-built confocal rheoscope to image the particle configurations of a colloidal suspension while simultaneously measuring its stress response. We find that as the gap decreases below 15 particle diameters, the viscosity first decreases from its bulk value, shows fluctuations with the gap, and then sharply increases for gaps below 3 particle diameters. These trends in the viscosity are shown to strongly correlate with the suspension microstructure. Further, we compare our experimental results to those from two different simulations techniques, which enables us to determine the relative contributions of hydrodynamic and short-range repulsive stresses to the suspension rheology. The first method uses the lubrication approximation to find the hydrodynamic stress and includes a short-range repulsive force between the particles while the second is a Stokesian dynamics simulation that calculates the full hydrodynamic stress in the suspension. We find that the decrease in the viscosity at moderate confinements has a significant contribution from both the

Studies in the evolution of hydrodynamic instabilities and their role in inertial confinement fusion

International Nuclear Information System (INIS)

Shvarts, D.; Oron, D.; Sadot, O.

2001-01-01

Hydrodynamic instabilities, such as the Rayleigh-Taylor and Richtmyer-Meshkov instabilities, have a central role when trying to achieve net thermonuclear fusion energy via the method of Inertial Confinement Fusion. We shall review recent theoretical, numerical and experimental work that describes the evolution of two- and three-dimensional perturbations. Finally, the effects of these perturbation on the ignition conditions, using new self-similar solutions for perturbed burn wave propagation will be discussed. (author)

Experimental characterization of the concrete behaviour under high confinement: influence of the saturation ratio and of the water/cement ratio

International Nuclear Information System (INIS)

Vu, X.H.

2007-08-01

The objective of this thesis is to experimentally characterize the influence of the saturation ratio and of the water/cement ratio of concrete on its behaviour under high confinement. This thesis lies within a more general scope of the understanding of concrete behaviour under severe loading situations (near field detonation or ballistic impacts). A near field detonation or an impact on a concrete structure generate very high levels of stress associated with complex loading paths in the concrete material. To validate concrete behaviour models, experimental results are required. The work presented in this thesis concerns tests conducted using a static triaxial press that allows to obtain stress levels of the order of the giga Pascal. The porous character of concrete and the high confinement required on the one hand, a development of a specimen protection device, and on the other hand, a development of an instrumentation with strain gauges, which is unprecedented for such high confinements. Hydrostatic and triaxial tests, conducted on the one hand on model materials and on the other hand on concrete, allowed to validate the developed experimental procedures as well as the technique of strain and stress measurements. The studies concerning the influence of the saturation ratio and of the water/cement ratio of concrete on its behaviour required the formulation of a plain baseline concrete and of two modified concretes with different water/cement ratios. The analysis of triaxial tests performed on the baseline concrete shows that the saturation ratio of concrete has a major influence on its static behaviour under high confinement. This influence is particularly marked for the concrete loading capacity and for the shape of limit state curves for saturation ratios greater than 50%. The concrete loading capacity increases with the confinement pressure for tests on dry concrete whereas beyond a given confinement pressure, it remains limited for wet or saturated concrete

Velocity dependence of friction of confined polymers

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, V.N.; Persson, B.N.J.

2009-01-01

We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate, and (b) polymer sliding on polymer. We discuss the velocity dependence of the frictional...... shear stress for both cases. In our simulations, the polymer films are very thin (approx. 3 nm), and the solid walls are connected to a thermostat at a short distance from the polymer slab. Under these circumstances we find that frictional heating effects are not important, and the effective temperature...... in the polymer film is always close to the thermostat temperature. In the first setup (a), for hydrocarbons with molecular lengths from 60 to 1400 carbon atoms, the shear stresses are nearly independent of molecular length, but for the shortest hydrocarbon C20H42 the frictional shear stress is lower. In all...

Kinetic studies of chemical shrinkage and residual stress formation in thermoset epoxy adhesives under confined curing conditions

Science.gov (United States)

Schumann, M.; Geiß, P. L.

2015-05-01

Faultless processing of thermoset polymers in demanding applications requires a profound mastering of the curing kinetics considering both the physico-chemical changes in the transition from the liquid to the solid state and the consolidation of the polymers network in the diffusion controlled curing regime past the gel point. Especially in adhesive joints shrinkage stress occurring at an early state of the curing process under confined conditions is likely to cause defects due to local debonding and thus reduce their strength and durability1. Rheometry is considered the method of choice to investigate the change of elastic and viscous properties in the progress of curing. Drawbacks however relate to experimental challenges in accessing the full range of kinetic parameters of thermoset resins with low initial viscosity from the very beginning of the curing reaction to the post-cure consolidation of the polymer due to the formation of secondary chemical bonds. Therefore the scope of this study was to interrelate rheological data with results from in-situ measurements of the shrinkage stress formation in adhesive joints and with the change of refractive index in the progress of curing. This combination of different methods has shown to be valuable in gaining advanced insight into the kinetics of the curing reaction. The experimental results are based on a multi component thermoset epoxy-amine adhesive.

Some aspects on alternative lines of magnetic confinement

International Nuclear Information System (INIS)

Lehnert, B.

1991-02-01

Facing the year 2000, some proposals for a balanced strategy of fusion research are given in this paper. Fusion research by the world community has made substantial progress, and it is now possible to build an experimental test reactor based on the tokamak confinement principle, in the form of a global commitment such as the ITER/NET project. Nevertheless further investigations are needed before the practical use of fusion energy becomes a reality. With regard to this, and to the time gap formed by the planning and construction period of ITER/NET, continued activities have to take place at the national laboratories, to preserve the quality of plasma physical research and the competence of fusion scientists and engineers, as well as to guarantee research on alternative lines aiming at an improved reactor concept. Some aspects are given in this context on the desired properties of an optimal fusion reactor, including a high plasma beta value, a minimized imposed toroidal magnetic field, controlled or non-existent disruptions, steady-state operation, minimized plasma-wall interaction, and the absence both of a stabilizing conducting wall and of active feedback systems. (au)

Influence of loading and unloading velocity of confining pressure on strength and permeability characteristics of crystalline sandstone

Science.gov (United States)

Zhang, Dong-ming; Yang, Yu-shun; Chu, Ya-pei; Zhang, Xiang; Xue, Yan-guang

2018-06-01

The triaxial compression test of crystalline sandstone under different loading and unloading velocity of confining pressure is carried out by using the self-made "THM coupled with servo-controlled seepage apparatus for containing-gas coal", analyzed the strength, deformation and permeability characteristics of the sample, the results show that: with the increase of confining pressures loading-unloading velocity, Mohr's stress circle center of the specimen shift to the right, and the ultimate intensity, peak strain and residual stress of the specimens increase gradually. With the decrease of unloading velocity of confining pressure, the axial strain, the radial strain and the volumetric strain of the sample decrease first and then increases, but the radial strain decreases more greatly. The loading and unloading of confining pressure has greater influence on axial strain of specimens. The deformation modulus decreases rapidly with the increase of axial strain and the Poisson's ratio decreases gradually at the initial stage of loading. When the confining pressure is loaded, the deformation modulus decrease gradually, and the Poisson's ratio increases gradually. When the confining pressure is unloaded, the deformation modulus increase gradually, and the Poisson's ratio decreases gradually. When the specimen reaches the ultimate intensity, the deformation modulus decreases rapidly, while the Poisson's ratio increases rapidly. The fitting curve of the confining pressure and the deformation modulus and the Poisson's ratio in accordance with the distribution of quadratic polynomial function in the loading-unloading confining pressure. There is a corresponding relationship between the evolution of rock permeability and damage deformation during the process of loading and unloading. In the late stage of yielding, the permeability increases slowly, and the permeability increases sharply after the rock sample is destroyed. Fitting the permeability and confining pressure

Fusion, magnetic confinement

International Nuclear Information System (INIS)

Berk, H.L.

1992-01-01

An overview is presented of the principles of magnetic confinement of plasmas for the purpose of achieving controlled fusion conditions. Sec. 1 discusses the different nuclear fusion reactions which can be exploited in prospective fusion reactors and explains why special technologies need to be developed for the supply of tritium or 3 He, the probable fuels. In Sec. 2 the Lawson condition, a criterion that is a measure of the quality of confinement relative to achieving fusion conditions, is explained. In Sec. 3 fluid equations are used to describe plasma confinement. Specific confinement configurations are considered. In Sec. 4 the orbits of particle sin magneti and electric fields are discussed. In Sec. 5 stability considerations are discussed. It is noted that confinement systems usually need to satisfy stability constraints imposed by ideal magnetohydrodynamic (MHD) theory. The paper culminates with a summary of experimental progress in magnetic confinement. Present experiments in tokamaks have reached the point that the conditions necessary to achieve fusion are being satisfied

Mechanical confinement regulates cartilage matrix formation by chondrocytes

Science.gov (United States)

Lee, Hong-Pyo; Gu, Luo; Mooney, David J.; Levenston, Marc E.; Chaudhuri, Ovijit

2017-12-01

Cartilage tissue equivalents formed from hydrogels containing chondrocytes could provide a solution for replacing damaged cartilage. Previous approaches have often utilized elastic hydrogels. However, elastic stresses may restrict cartilage matrix formation and alter the chondrocyte phenotype. Here we investigated the use of viscoelastic hydrogels, in which stresses are relaxed over time and which exhibit creep, for three-dimensional (3D) culture of chondrocytes. We found that faster relaxation promoted a striking increase in the volume of interconnected cartilage matrix formed by chondrocytes. In slower relaxing gels, restriction of cell volume expansion by elastic stresses led to increased secretion of IL-1β, which in turn drove strong up-regulation of genes associated with cartilage degradation and cell death. As no cell-adhesion ligands are presented by the hydrogels, these results reveal cell sensing of cell volume confinement as an adhesion-independent mechanism of mechanotransduction in 3D culture, and highlight stress relaxation as a key design parameter for cartilage tissue engineering.

Reynolds stress and shear flow generation

DEFF Research Database (Denmark)

Korsholm, Søren Bang; Michelsen, Poul; Naulin, V.

2001-01-01

The so-called Reynolds stress may give a measure of the self-consistent flow generation in turbulent fluids and plasmas by the small-scale turbulent fluctuations. A measurement of the Reynolds stress can thus help to predict flows, e.g. shear flows in plasmas. This may assist the understanding...... of improved confinement scenarios such as H-mode confinement regimes. However, the determination of the Reynolds stress requires measurements of the plasma potential, a task that is difficult in general and nearly impossible in hot plasmas in large devices. In this work we investigate an alternative method......, based on density measurements, to estimate the Reynolds stress, and demonstrate the validity range of this quantity, which we term the pseudo-Reynolds stress. The advantage of such a quantity is that accurate measurements of density fluctuations are much easier to obtain experimentally. Prior...

[Complex posttraumatic stress disorder].

Science.gov (United States)

Green, Tamar; Kotler, Moshe

2007-11-01

The characteristic symptoms resulting from exposure to an extreme trauma include three clusters of symptoms: persistent experience of the traumatic event, persistent avoidance of stimuli associated with the trauma and persistent symptoms of increased arousal. Beyond the accepted clusters of symptoms for posttraumatic stress disorder exists a formation of symptoms related to exposure to extreme or prolonged stress e.g. childhood abuse, physical violence, rape, and confinement within a concentration camp. With accumulated evidence of the existence of these symptoms began a trail to classify a more complex syndrome, which included, but was not confined to the symptoms of posttraumatic stress disorder. This review addresses several subjects for study in complex posttraumatic stress disorder, which is a complicated and controversial topic. Firstly, the concept of complex posttraumatic stress disorder is presented. Secondly, the professional literature relevant to this disturbance is reviewed and finally, the authors present the polemic being conducted between the researchers of posttraumatic disturbances regarding validity, reliability and the need for separate diagnosis for these symptoms.

Eleven years of net network research activity - inr contributions

International Nuclear Information System (INIS)

Deaconu, V.; Ionita, I.; Meleg, T.; Deaconu, M.; Truta, C.; Oncioiu, G.

2013-01-01

The European Network on Neutron Techniques Standardization for Structural Integrity (NeT) was established in 2002, grouping institutions from industry, research and academic media. Coordinated by the European Commission.s Joint Research Centre, the main mission of this network is to develop experimental and numerical techniques and standards for the reliable characterisation of residual stresses in structural welds. Each problem is tackled by creating a dedicated Task Group which manages measurement and modelling round robin studies and undertakes a thorough analysis and interpretation of the results. Over forty institutions are active NeT partners, their specific involvement and contributions being summarised in this paper. The Institute for Nuclear Research Pitesti (INR) is one of NeT founders and its contribution is related to numerical modelling, specimen analysis, material characterisation, data analysis or SANS support. This is also emphasised throughout this paper, together with the specific NeT research topics presentation. (authors)

Laser drivers for inertial confinement fusion

International Nuclear Information System (INIS)

Holzrichter, J.F.

1983-01-01

Inertial Confinement Fusion (ICF) is the technology that we are developing to access the vast stored energy potential of deuterium fuel located in the world's water supply. This form of fusion is accomplished by compressing and heating small volumes of D-T fuel to very high temperatures (greater than 100M 0 C) and to very high densities (greater than 1000 times the normal liquid density). Under these fuel conditions, a thermonuclear reaction can occur, leading to a net energy release compared to the energy used to heat the fuel initially. To accomplish the condition where fusion reactions begin, effective drivers are required. These are lasers or particle beam accelerators which can provide greater than 10 14 W/cm 2 over millimeter scale targets with an appropriately programmed intensity vs time. At present, we are using research lasers to obtain an understanding of the physics and engineering of fuel compression

Stress-Strain Relationship of Synthetic Fiber Reinforced Concrete Columns

Directory of Open Access Journals (Sweden)

Rosidawani

2017-01-01

Full Text Available Many empirical confinement models for normal and high strength concrete have been developed. Nevertheless, reported studies in the term of confinement of fiber reinforced concrete are limited. Whereas, the use of fiber reinforced concrete in structural elements has become the subject of the research and has indicated positive experiences. Since the stress-strain relationship of concrete in compression is required for analysis of structural members, the study of the stress-strain relationship for synthetic fiber reinforced concrete is substantial. The aim of the study is to examine the capabilities of the various models available in the literature to predict the actual experimental behavior of synthetic fiber reinforced high-strength concrete columns. The experimental data used are the results of the circular column specimens with the spiral spacing and the volume fraction of synthetic fiber as the test variables. The axial stress-strain curves from the tests are then compared with the various models of confinement from the literature. The performance index of each model is measured by using the coefficient of variation (COV concept of stress and strain behavior parameter. Among the confinement models, Cusson model shows the closest valid value of the coefficient of variation.

Fusion Plasma Theory: Task 1, Magnetic confinement Fusion Plasma Theory

International Nuclear Information System (INIS)

Callen, J.D.

1993-01-01

The research performed under this grant during the current year has concentrated on few tokamak plasma confinement issues: applications of our new Chapman-Enskog-like approach for developing hybrid fluid/kinetic descriptions of tokamak plasmas; multi-faceted studies as part of our development of a new interacting island paradigm for the tokamak equilibrium'' and transport; investigations of the resolution power of BES and ECE diagnostics for measuring core plasma fluctuations; and studies of net transport in the presence of fluctuating surfaces. Recent progress and publications in these areas, and in the management of the NERSC node and the fusion theory workstations are summarized briefly in this report

Confinement models for gluons

International Nuclear Information System (INIS)

Khadkikar, S.B.; Vinodkumar, P.C.

1987-04-01

Confinement model for gluons using a 'colour super current' is formulated. An attempt has been made to derive a suitable dielectric function corresponding to the current confinement model. A simple inhomogeneous dielectric confinement model for gluons is studied for comparison. The model Hamiltonians are second quantized and the glueball states are constructed. The spurious motion of the centre of confinement is accounted for. The results of the current confinement scheme are found to be in good agreement with the experimental candidates for glueballs. (author). 16 refs, 3 tabs

Modal gain and confinement factors in top- and bottom-emitting photonic-crystal VCSEL

International Nuclear Information System (INIS)

Czyszanowski, T; Thienpont, H; Panajotov, K; Dems, M

2008-01-01

We investigate the modal characteristics of a phosphide photonic-crystal vertical-cavity surface-emitting diode laser (VCSEL) by using the three-dimensional, full vectorial plane wave admittance method. A single-defect, photonic crystal is defined as a regular, hexagonal net of holes with varying depths. The modal gain and confinement factors are compared for two VCSEL structures: with emission either through the DBR with the photonic crystal or through the DBR free of photonic crystal. Significant improvement in the beam quality is demonstrated for the second design

Comments on confinement criteria

International Nuclear Information System (INIS)

Kurak, V.; Schroer, B.; Swieca, J.A.

1977-01-01

For a QED 2 model with SU(n) flavour, the nature of the physical states space is more subtle than one expects on the basis of the loop criterion for confinement. One may have colour confinement without confinement of the fundamental flavour representation. Attempts to formulate confinement criteria in which the quark fields play a more fundamental role are discussed [pt

Response of a lithium fall to an inertially confined fusion microexplosion

International Nuclear Information System (INIS)

Hovingh, J.; Blink, J.; Glenn, L.

1978-01-01

One of the most difficult technology problems in an inertially confined fusion reactor is the survival of the structure from the repeated stresses caused by the microexplosion products. To mitigate the damage from the microexplosion products, a thick lithium fall can be circulated in front of the structure. This fall will absorb the short-ranged products and moderate and attenuate the neutrons. This paper discusses the response of the fall to the microexplosion products, and estimates the resulting loading and stresses in the first structural wall

Electrical charging effects on the sliding friction of a model nano-confined ionic liquid

Energy Technology Data Exchange (ETDEWEB)

Capozza, R.; Vanossi, A. [International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste (Italy); CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste (Italy); Benassi, A. [CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste (Italy); Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, 01062 Dresden (Germany); Tosatti, E. [International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste (Italy); CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste (Italy); International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34014 Trieste (Italy)

2015-10-14

Recent measurements suggest the possibility to exploit ionic liquids (ILs) as smart lubricants for nano-contacts, tuning their tribological and rheological properties by charging the sliding interfaces. Following our earlier theoretical study of charging effects on nanoscale confinement and squeezout of a model IL, we present here molecular dynamics simulations of the frictional and lubrication properties of that model under charging conditions. First, we describe the case when two equally charged plates slide while being held together to a confinement distance of a few molecular layers. The shear sliding stress is found to rise strongly and discontinuously as the number of IL layers decreases stepwise. However, the shear stress shows, within each given number of layers, only a weak dependence upon the precise value of the normal load, a result in agreement with data extracted from recent experiments. We subsequently describe the case of opposite charging of the sliding plates and follow the shear stress when the charging is slowly and adiabatically reversed in the course of time, under fixed load. Despite the fixed load, the number and structure of the confined IL layers change with changing charge, and that in turn drives strong friction variations. The latter involves first of all charging-induced freezing of the IL film, followed by a discharging-induced melting, both made possible by the nanoscale confinement. Another mechanism for charging-induced frictional changes is a shift of the plane of maximum shear from mid-film to the plate-film interface, and vice versa. While these occurrences and results invariably depend upon the parameters of the model IL and upon its specific interaction with the plates, the present study helps identifying a variety of possible behavior, obtained under very simple assumptions, while connecting it to an underlying equilibrium thermodynamics picture.

The effect of pressure loadings on the conservatism of the net-section stress criterion for the failure of cracked stainless steel piping

International Nuclear Information System (INIS)

Smith, E.

1994-01-01

The technological problem of intergranular stress corrosion cracking (IGSCC) of type 304 stainless steel piping in boiling water reactor piping systems, has provided the motivation for the considerable research interest in the integrity of cracked piping systems that are fabricated by ductile materials. IGSCC cracks are able to form at the inner surfaces of pipes. The cracks are circumferential and are able to grow slowly in service by a time dependent environmentally assisted mechanism. From a safety standpoint, it is important to know whether accident condition loadings will drive a part-through IGSCC crack unstably across the pipe thickness by a non-environmentally assisted fracture mechanism, and the resulting through-wall crack then propagate around the pipe circumference leading to a complete pipe severance. A methodology that has been developed to address this problem is a net-section stress methodology. The net-section stress approach for predicting the onset of crack extension in a piping system can give overly conservative predictions because a piping system is built-in at its end points and because crack extension requires some plastic deformation. The present paper is concerned with identifying the role of system pressure on the degree of conservatism, and two effects are important. Firstly, by inducing an axial tensile force at the cracked section, it is shown that the factor of conservatism can be increased. Secondly it is shown that the pressure induced moment at the cracked section behaves no differently to other contributions to this moment, in that all sources are associated with the same limited amount of elastic follow-up. All sources are associated with the same elastic flexibility parameter L*, which depends solely on the flexibility of the system and not on the nature of the loading

Inclusion of biotic stress (consumer pressure) alters predictions from the stress gradient hypothesis

NARCIS (Netherlands)

Smit, Christian; Rietkerk, Max; Wassen, Martin J.

2009-01-01

The stress gradient hypothesis (SGH) predicts a shift from net negative interactions in benign environments towards net positive in harsh environments in ecological communities. While several studies found support for the SGH, others found evidence against it, leading to a debate on how nature and

Magnetic force micropiston: An integrated force/microfluidic device for the application of compressive forces in a confined environment

Science.gov (United States)

Fisher, J. K.; Kleckner, N.

2014-02-01

Cellular biology takes place inside confining spaces. For example, bacteria grow in crevices, red blood cells squeeze through capillaries, and chromosomes replicate inside the nucleus. Frequently, the extent of this confinement varies. Bacteria grow longer and divide, red blood cells move through smaller and smaller passages as they travel to capillary beds, and replication doubles the amount of DNA inside the nucleus. This increase in confinement, either due to a decrease in the available space or an increase in the amount of material contained in a constant volume, has the potential to squeeze and stress objects in ways that may lead to changes in morphology, dynamics, and ultimately biological function. Here, we describe a device developed to probe the interplay between confinement and the mechanical properties of cells and cellular structures, and forces that arise due to changes in a structure's state. In this system, the manipulation of a magnetic bead exerts a compressive force upon a target contained in the confining space of a microfluidic channel. This magnetic force microfluidic piston is constructed in such a way that we can measure (a) target compliance and changes in compliance as induced by changes in buffer, extract, or biochemical composition, (b) target expansion force generated by changes in the same parameters, and (c) the effects of compression stress on a target's structure and function. Beyond these issues, our system has general applicability to a variety of questions requiring the combination of mechanical forces, confinement, and optical imaging.

Quantitative trait loci for magnitude of the plasma cortisol response to confinement in rainbow trout.

Science.gov (United States)

Quillet, E; Krieg, F; Dechamp, N; Hervet, C; Bérard, A; Le Roy, P; Guyomard, R; Prunet, P; Pottinger, T G

2014-04-01

Better understanding of the mechanisms underlying interindividual variation in stress responses and their links with production traits is a key issue for sustainable animal breeding. In this study, we searched for quantitative trait loci (QTL) controlling the magnitude of the plasma cortisol stress response and compared them to body size traits in five F2 full-sib families issued from two rainbow trout lines divergently selected for high or low post-confinement plasma cortisol level. Approximately 1000 F2 individuals were individually tagged and exposed to two successive acute confinement challenges (1 month interval). Post-stress plasma cortisol concentrations were determined for each fish. A medium density genome scan was carried out (268 markers, overall marker spacing less than 10 cM). QTL detection was performed using qtlmap software, based on an interval mapping method (http://www.inra.fr/qtlmap). Overall, QTL of medium individual effects on cortisol responsiveness (confinement stressor are distinct traits sharing only part of their genetic control. Chromosomal location of the steroidogenic acute regulatory protein (STAR) makes it a good potential candidate gene for one of the QTL. Finally, comparison of body size traits QTL (weight, length and body conformation) with cortisol-associated QTL did not support evidence for negative genetic relationships between the two types of traits. © 2014 Stichting International Foundation for Animal Genetics.

Gluon confinement

International Nuclear Information System (INIS)

Novello, M.; Lorenci, V.A. de; Elbaz, E.

1997-02-01

In this paper we present a new model for a gauge field theory such that self-interacting spin-one particles can be confined in a compact domain. The necessary conditions to produce the confining potential appear already in the properties of the eikonal structure generated by the particular choice of the dynamics. (author)

Building solids inside nano-space: from confined amorphous through confined solvate to confined 'metastable' polymorph.

Science.gov (United States)

Nartowski, K P; Tedder, J; Braun, D E; Fábián, L; Khimyak, Y Z

2015-10-14

The nanocrystallisation of complex molecules inside mesoporous hosts and control over the resulting structure is a significant challenge. To date the largest organic molecule crystallised inside the nano-pores is a known pharmaceutical intermediate - ROY (259.3 g mol(-1)). In this work we demonstrate smart manipulation of the phase of a larger confined pharmaceutical - indomethacin (IMC, 357.8 g mol(-1)), a substance with known conformational flexibility and complex polymorphic behaviour. We show the detailed structural analysis and the control of solid state transformations of encapsulated molecules inside the pores of mesoscopic cellular foam (MCF, pore size ca. 29 nm) and controlled pore glass (CPG, pore size ca. 55 nm). Starting from confined amorphous IMC we drive crystallisation into a confined methanol solvate, which upon vacuum drying leads to the stabilised rare form V of IMC inside the MCF host. In contrast to the pure form, encapsulated form V does not transform into a more stable polymorph upon heating. The size of the constraining pores and the drug concentration within the pores determine whether the amorphous state of the drug is stabilised or it recrystallises into confined nanocrystals. The work presents, in a critical manner, an application of complementary techniques (DSC, PXRD, solid-state NMR, N2 adsorption) to confirm unambiguously the phase transitions under confinement and offers a comprehensive strategy towards the formation and control of nano-crystalline encapsulated organic solids.

Horizontal ichthyoplankton tow-net system with unobstructed net opening

Science.gov (United States)

Nester, Robert T.

1987-01-01

The larval fish sampler described here consists of a modified bridle, frame, and net system with an obstruction-free net opening and is small enough for use on boats 10 m or less in length. The tow net features a square net frame attached to a 0.5-m-diameter cylinder-on-cone plankton net with a bridle designed to eliminate all obstructions forward of the net opening, significantly reducing currents and vibrations in the water directly preceding the net. This system was effective in collecting larvae representing more than 25 species of fish at sampling depths ranging from surface to 10 m and could easily be used at greater depths.

Higher-moment measurements of net-kaon, net-charge and net-proton multiplicity distributions at STAR

International Nuclear Information System (INIS)

Sarkar, Amal

2014-01-01

In this paper, we report the measurements of the various moments, such as mean, standard deviation (σ), skewness (S) and kurtosis (κ) of the net-kaon, net-charge and net-proton multiplicity distributions at mid-rapidity in Au + Au collisions from √(s NN )=7.7 to 200 GeV with the STAR experiment at RHIC. This work has been done with the aim to locate the critical point on the QCD phase diagram. These moments and their products are related to the thermodynamic susceptibilities of conserved quantities such as net baryon number, net charge, and net strangeness as well as to the correlation length of the system which diverges in an ideal infinite thermodynamic system at the critical point. For a finite system, existing for a finite time, a non-monotonic behavior of these variables would indicate the presence of the critical point. Furthermore, we also present the moment products Sσ, κσ 2 of net-kaon, net-charge and net-proton multiplicity distributions as a function of collision centrality and energy. The energy and the centrality dependence of higher moments and their products have been compared with different models

Geomorphic effects, flood power, and channel competence of a catastrophic flood in confined and unconfined reaches of the upper Lockyer valley, southeast Queensland, Australia

Science.gov (United States)

Thompson, Chris; Croke, Jacky

2013-09-01

Flooding is a persistent natural hazard, and even modest changes in future climate are believed to lead to large increases in flood magnitude. Previous studies of extreme floods have reported a range of geomorphic responses from negligible change to catastrophic channel change. This paper provides an assessment of the geomorphic effects of a rare, high magnitude event that occurred in the Lockyer valley, southeast Queensland in January 2011. The average return interval of the resulting flood was ~ 2000 years in the upper catchment and decreased to ~ 30 years downstream. A multitemporal LiDAR-derived DEM of Difference (DoD) is used to quantify morphological change in two study reaches with contrasting valley settings (confined and unconfined). Differences in geomorphic response between reaches are examined in the context of changes in flood power, channel competence and degree of valley confinement using a combination of one-dimensional (1-D) and two-dimensional (2-D) hydraulic modelling. Flood power peaked at 9800 W m- 2 along the confined reach and was 2-3 times lower along the unconfined reach. Results from the DoD confirm that the confined reach was net erosional, exporting ~ 287,000 m3 of sediment whilst the unconfined reach was net depositional gaining ~ 209,000 m3 of sediment, 70% of the amount exported from the upstream, confined reach. The major sources of eroded sediment in the confined reach were within channel benches and macrochannel banks resulting in a significant increase of channel width. In the unconfined reach, the benches and floodplains were the major loci for deposition, whilst the inner channel exhibited minor width increases. The presence of high stream power values, and resultant high erosion rates, within the confined reach is a function of the higher energy gradient of the steeper channel that is associated with knickpoint development. Dramatic differences in geomorphic responses were observed between the two adjacent reaches of

Confinement of Reinforced-Concrete Columns with Non-Code Compliant Confining Reinforcement plus Supplemental Pen-Binder

Directory of Open Access Journals (Sweden)

Anang Kristianto

2012-11-01

Full Text Available One of the important requirements for earthquake resistant building related to confinement is the use of seismic hooks in the hoop or confining reinforcement of reinforced-concrete column elements. However, installation of a confining reinforcement with a 135-degree hook is not easy. Therefore, in practice, many construction workers apply a confining reinforcement with a 90-degreehook (non-code compliant. Based on research and records of recent earthquakes in Indonesia, the use of a non-code compliant confining reinforcement for concrete columns produces structures with poor seismic performance. This paper presents a study that introduces an additional element that is expected to improve the effectiveness of concrete columns confined with a non-code compliant confining reinforcement. The additional element, named a pen-binder, is used to keep the non-code compliant confining reinforcement in place. The effectiveness of this element under pure axial concentric loading was investigatedcomprehensively.The specimens tested in this study were 18 concrete columns,with a cross-section of 170 mm x 170 mm and a height of 480 mm. The main test variables were the material type of the pen-binder, the angle of the hook, and the confining reinforcement configuration.The test results indicate that adding pen-binders can effectively improve the strength and ductility of the column specimens confined with a non-code compliant confining reinforcement

Non-dissipative energy capture of confined liquid in nanopores

Energy Technology Data Exchange (ETDEWEB)

Xu, Baoxing; Chen, Xi [Columbia Nanomechanics Research Center, Department of Earth and Environmental Engineering, Columbia University, New York, New York 10027 (United States); Lu, Weiyi; Zhao, Cang [Department of Structural Engineering, University of California–San Diego, La Jolla, California 92093-0085 (United States); Qiao, Yu, E-mail: yqiao@ucsd.edu [Department of Structural Engineering, University of California–San Diego, La Jolla, California 92093-0085 (United States); Program of Materials Science and Engineering, University of California–San Diego, La Jolla, CA 92093 (United States)

2014-05-19

In the past, energy absorption of protection/damping materials is mainly based on energy dissipation, which causes a fundamental conflict between the requirements of safety/comfort and efficiency. In the current study, a nanofluidic “energy capture” system is reported, which is based on nanoporous materials and nonwetting liquid. Both molecular dynamics simulations and experiments show that as the liquid overcomes the capillary effect and infiltrates into the nanopores, the mechanical energy of a stress wave could be temporarily stored by the confined liquid phase and isolated from the wave energy transmission path. Such a system can work under a relatively low pressure for mitigating high-pressure stress waves, not necessarily involved in any energy dissipation processes.

Non-dissipative energy capture of confined liquid in nanopores

International Nuclear Information System (INIS)

Xu, Baoxing; Chen, Xi; Lu, Weiyi; Zhao, Cang; Qiao, Yu

2014-01-01

In the past, energy absorption of protection/damping materials is mainly based on energy dissipation, which causes a fundamental conflict between the requirements of safety/comfort and efficiency. In the current study, a nanofluidic “energy capture” system is reported, which is based on nanoporous materials and nonwetting liquid. Both molecular dynamics simulations and experiments show that as the liquid overcomes the capillary effect and infiltrates into the nanopores, the mechanical energy of a stress wave could be temporarily stored by the confined liquid phase and isolated from the wave energy transmission path. Such a system can work under a relatively low pressure for mitigating high-pressure stress waves, not necessarily involved in any energy dissipation processes.

Plasma confinement

CERN Document Server

Hazeltine, R D

2003-01-01

Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

Numerical Investigations On The Seismic Behaviour Of Confined Masonry Walls

International Nuclear Information System (INIS)

Calderini, Chiara; Cattari, Serena; Lagomarsino, Sergio

2008-01-01

In the last century, severe earthquakes highlighted the seismic vulnerability of unreinforced masonry buildings. Many technological innovations have been introduced in time in order to improve resistance, ductility, and dissipation properties of this type of constructions. The most widely diffused are reinforced masonry and confined masonry. Damage observation of recent earthquakes demonstrated the effectiveness of the response of confined masonry structures to seismic actions. In general, in this type of structures, reinforced concrete beams and columns are not main structural elements, however, they have the following functions: to confine masonry in order to increase its ductility; to bear tensile stresses derived from bending; to contrast the out-of-plane overturning of masonry panels. It is well evident that these functions are as much effectively performed as the connection between masonry and reinforced concrete elements is good (for example by mean of local interlocking or reinforcements). Confined masonry structures have been extensively studied in the last decades both from a theoretical point of view and by experimental tests Aims of this paper is to give a contribution to the understanding of the seismic behaviour of confined masonry walls by means of numerical parametrical analyses. There latter are performed by mean of the finite element method; a nonlinear anisotropic constitutive law recently developed for masonry is adopted. Comparison with available experimental results are carried out in order to validate the results. A comparison between the resistance obtained from the numerical analyses and the prevision provided by simplified resistance criteria proposed in literature and in codes is finally provided

Quantum confinement in Si and Ge nanostructures: Theory and experiment

International Nuclear Information System (INIS)

Barbagiovanni, Eric G.; Lockwood, David J.; Simpson, Peter J.; Goncharova, Lyudmila V.

2014-01-01

The role of quantum confinement (QC) in Si and Ge nanostructures (NSs) including quantum dots, quantum wires, and quantum wells is assessed under a wide variety of fabrication methods in terms of both their structural and optical properties. Structural properties include interface states, defect states in a matrix material, and stress, all of which alter the electronic states and hence the measured optical properties. We demonstrate how variations in the fabrication method lead to differences in the NS properties, where the most relevant parameters for each type of fabrication method are highlighted. Si embedded in, or layered between, SiO 2 , and the role of the sub-oxide interface states embodies much of the discussion. Other matrix materials include Si 3 N 4 and Al 2 O 3 . Si NSs exhibit a complicated optical spectrum, because the coupling between the interface states and the confined carriers manifests with varying magnitude depending on the dimension of confinement. Ge NSs do not produce well-defined luminescence due to confined carriers, because of the strong influence from oxygen vacancy defect states. Variations in Si and Ge NS properties are considered in terms of different theoretical models of QC (effective mass approximation, tight binding method, and pseudopotential method). For each theoretical model, we discuss the treatment of the relevant experimental parameters

Fluvial gravel stabilization by net-spinning Hydropsychid caddisflies: exploring the magnitude and geographic scope of ecosystem engineering effect and evaluating resistance to anthropogenic stresses

Science.gov (United States)

Daniels, M.; Albertson, L.; Sklar, L. S.; Tumolo, B.; Mclaughlin, M. K.

2017-12-01

Several studies have demonstrated the substantial effects that organisms can have on earth surface processes. Known as ecosystem engineers, in streams these organisms maintain, modify, or create physical habitat structure by influencing fluvial processes such as gravel movement, fine sediment deposition and bank erosion. However, the ecology of ecosystem engineers and the magnitude of ecosystem engineering effects in a world increasingly influence by anthropogenically-driven changes is not well understood. Here we present a synthesis of research findings on the potential gravel stabilization effects of Hydropsychid caddisflies, a globally distributed group of net-spinning insects that live in the benthic substrate of most freshwater streams. Hydropsychid caddisflies act as ecosystem engineers because these silk structures can fundamentally alter sediment transport conditions, including sediment stability and flow currents. The silk nets spun by these insects attach gravel grains to one another, increasing the shear stress required to initiate grain entrainment. In a series of independent laboratory experiments, we investigate the gravel size fractions most affected by these silk attachments. We also investigate the role of anthropogenic environmental stresses on ecosystem engineering potential by assessing the impact of two common stressors, high fine sediment loads and stream drying, on silk structures. Finally, an extensive field survey of grain size and Hydropsychid caddisfly population densities informs a watershed-scale network model of Hydropsychid caddisfly gravel stabilizing potential. Our findings provide some of the first evidence that caddisfly silk may be a biological structure that is resilient to various forms of human-mediated stress and that the effects of animal ecosystem engineers are underappreciated as an agent of resistance and recovery for aquatic communities experiencing changes in sediment loads and hydrologic regimes.

Quark confinement

International Nuclear Information System (INIS)

Joos, H.

1976-07-01

The main topics of these lectures are: phenomenological approach to quark confinement, standard Lagrangian of hadrondynamics, Lagrangian field theory and quark confinement, classical soliton solutions in a simple model, quantization of extended systems, colour charge screening and quantization on a lattice and remarks on applications. A survey of the scientific publications listed according to the topics until 26 March 1976 is supplemented. (BJ) [de

L-histidine enhances learning in stressed zebrafish

Directory of Open Access Journals (Sweden)

L.P.V. Cofiel

2009-01-01

Full Text Available The aim of the present study was to determine the effect of the histaminergic precursor L-histidine and the H3 receptor antagonist thioperamide on the learning process of zebrafish submitted or not to confinement stress. On each of the 5 consecutive days of experiment (D1, D2, D3, D4, D5, animals had to associate an interruption of the aquarium air supply with food offering. Non-stressed zebrafish received an intraperitoneal injection of 100 mg/kg L-histidine, 10 mg/kg thioperamide or saline after training. Stressed animals received drug treatment and then were submitted to confinement stress for 1 h before the learning procedure. Time to approach the feeder was measured (in seconds and was considered to be indicative of learning. A decrease in time to approach the feeder was observed in the saline-treated group (D1 = 141.92 ± 13.57; D3 = 55 ± 13.54, indicating learning. A delay in learning of stressed animals treated with saline was observed (D1 = 217.5 ± 25.66. L-histidine facilitated learning in stressed (D1 = 118.68 ± 13.9; D2 = 45.88 ± 8.2 and non-stressed (D1 = 151.11 ± 19.20; D5 = 62 ± 14.68 animals. Thioperamide inhibited learning in non-stressed (D1 = 110.38 ± 9.49; D4 = 58.79 ± 16.83 and stressed animals (D1 = 167.3 ± 26.39; D5 = 172.15 ± 27.35. L-histidine prevented the increase in blood glucose after one session of confinement (L-histidine = 65.88 ± 4.50; control = 53 ± 3.50 mg/dL. These results suggest that the histaminergic system enhances learning and modulates stress responses in zebrafish.

Multiobjective Shape Optimization for Deployment and Adjustment Properties of Cable-Net of Deployable Antenna

Directory of Open Access Journals (Sweden)

Guoqiang You

2015-01-01

Full Text Available Based on structural features of cable-net of deployable antenna, a multiobjective shape optimization method is proposed to help to engineer antenna’s cable-net structure that has better deployment and adjustment properties. In this method, the multiobjective optimum mathematical model is built with lower nodes’ locations of cable-net as variables, the average stress ratio of cable elements and strain energy as objectives, and surface precision and natural frequency of cable-net as constraints. Sequential quadratic programming method is used to solve this nonlinear mathematical model in conditions with different weighting coefficients, and the results show the validity and effectiveness of the proposed method and model.

Banana fluxes in the plateau regime for a nonaxisymmetrically confined plasma

International Nuclear Information System (INIS)

Balescu, R.; Fantechi, S.

1990-01-01

The banana (or banana-plateau) fluxes, related to the generalized stresses left-angle B·∇·π α(n) right-angle, left-angle B T ·∇·π α(n) right-angle have been determined in the plateau regime, for a plasma confined by a toroidal magnetic field of arbitrary geometry. The complete set of transport coefficients for both the ''parallel'' (ambipolar) and ''toroidal'' (nonambipolar) banana fluxes was obtained in the 13-moment (13M) approximation, going beyond the previously known expressions in the nonaxisymmetric case. The main emphasis is laid on the structure of the transport matrix and of its coefficients. It is shown that the Onsager symmetry of this matrix partly breaks down (for the mixed electron--ion coefficients) in a nonaxisymmetrically confined plasma

Chernobyl new safe confinement

International Nuclear Information System (INIS)

Dodd, L.

2011-01-01

The author presents the new safe confinement that will be commissioned at Unit 4 of the Chernobyl NPP in 2015. The confinement will ensure that Chernobyl Unit 4 will be placed in an environmentally safe condition for at least next 100 years. The article highlights the current work status, future perspectives and the feasibility of confinement concept [ru

Experience with the construction of the cable net cooling tower at Schmehausen

International Nuclear Information System (INIS)

Erdmann, W.

1977-01-01

The static system of the cooling tower consists of a concrete column 181 metres high from which a 145 meter high cable with a base diameter of 141 metres is suspended and tensioned. The cable net is covered on the inside with aluminium sheeting. Banks of tubes, which constitute the actual coding system, are arranged in the form of rings around the column in a self-supporting structure. Of the very wide range of problems which occurred in the construction of this cooling tower, the following are discussed in the paper: 1) Stressing of the concrete column during the construction period. 2) Stiffening the net using separation rings. 3) Net connection points on the ring foundation. 4) Control of the cable forces and the cable net geometry. 5) Start of sheeting erection. (orig.) [de

Development of net-current free heliotron plasmas in the Large Helical Device

International Nuclear Information System (INIS)

Komori, A.; Yamada, H.; Kaneko, O.; Kawahata, K.; Mutoh, T.; Ohyabu, N.; Imagawa, S.; Ida, K.; Nagayama, Y.; Shimozuma, T.; Watanabe, K.Y.; Mito, T.; Kobayashi, M.; Nagaoka, K.; Sakamoto, R.; Ohdachi, S.; Sakakibara, S.; Ashikawa, N.; Igami, H.; Kasahara, H.; Kubo, S.; Kumazawa, R.; Nishiura, M.; Masuzaki, S.; Tanaka, K.; Toi, K.; Yoshinuma, M.; Narushima, Y.; Tamura, N.; Saito, K.; Seki, T.; Sudo, S.; Tanaka, H.; Tokuzawa, T.; Yanagi, N.; Yokoyama, M.; Yoshimura, Y.; Akiyama, T.; Chikaraishi, H.; Emoto, M.; Funaba, H.; Goncharov, P.; Goto, M.; Ichiguchi, K.; Ido, T.; Ikeda, K.; Yoshida, N.; Inagaki, S.; Idei, H.; Feng, Y.; Weller, A.; Fukuda, T.; Mitarai, O.; Murakami, S.; Nakamura, Y.; Hino, T.; Ohno, N.; Okamura, T.; Iio, S.; Chowdhuri, M.; Ezumi, N.; Garcia, L.; Ichimura, M.; Irie, M.; Isayama, Akihiko; Iwamae, Atsushi; Takenaga, Hidenobu; Urano, Hajime

2008-10-01

Remarkable progress in the physical parameters of net-current free plasmas has been made in the Large Helical Device (LHD) since the last Fusion Energy Conference in Chengdu, 2006 (O. Motojima et al., Nucl. Fusion 47 (2007) S668). The beta value reached 5 % and a high beta state beyond 4.5% from the diamagnetic measurement has been maintained for longer than 100 times the energy confinement time. The density and temperature regimes also have been extended. The central density has exceeded 1.0x10 21 m -3 due to the formation of an Internal Diffusion Barrier (IDB). The ion temperature has reached 6.8 keV at the density of 2x10 19 m -3 , which is associated with the suppression of ion heat conduction loss. Although these parameters have been obtained in separated discharges, each fusion-reactor relevant parameter has elucidated the potential of net-current free heliotron plasmas. Diversified studies in recent LHD experiments are reviewed in this paper. (author)

Net-baryon-, net-proton-, and net-charge kurtosis in heavy-ion collisions within a relativistic transport approach

International Nuclear Information System (INIS)

Nahrgang, Marlene; Schuster, Tim; Stock, Reinhard; Mitrovski, Michael; Bleicher, Marcus

2012-01-01

We explore the potential of net-baryon, net-proton and net-charge kurtosis measurements to investigate the properties of hot and dense matter created in relativistic heavy-ion collisions. Contrary to calculations in a grand-canonical ensemble we explicitly take into account exact electric and baryon charge conservation on an event-by-event basis. This drastically limits the width of baryon fluctuations. A simple model to account for this is to assume a grand-canonical distribution with a sharp cut-off at the tails. We present baseline predictions of the energy dependence of the net-baryon, net-proton and net-charge kurtosis for central (b≤2.75 fm) Pb+Pb/Au+Au collisions from E lab =2A GeV to √(s NN )=200 GeV from the UrQMD model. While the net-charge kurtosis is compatible with values around zero, the net-baryon number decreases to large negative values with decreasing beam energy. The net-proton kurtosis becomes only slightly negative for low √(s NN ). (orig.)

Fracture mechanics of hydroxyapatite single crystals under geometric confinement.

Science.gov (United States)

Libonati, Flavia; Nair, Arun K; Vergani, Laura; Buehler, Markus J

2013-04-01

Geometric confinement to the nanoscale, a concept that refers to the characteristic dimensions of structural features of materials at this length scale, has been shown to control the mechanical behavior of many biological materials or their building blocks, and such effects have also been suggested to play a crucial role in enhancing the strength and toughness of bone. Here we study the effect of geometric confinement on the fracture mechanism of hydroxyapatite (HAP) crystals that form the mineralized phase in bone. We report a series of molecular simulations of HAP crystals with an edge crack on the (001) plane under tensile loading, and we systematically vary the sample height whilst keeping the sample and the crack length constant. We find that by decreasing the sample height the stress concentration at the tip of the crack disappears for samples with a height smaller than 4.15nm, below which the material shows a different failure mode characterized by a more ductile mechanism with much larger failure strains, and the strength approaching that of a flaw-less crystal. This study directly confirms an earlier suggestion of a flaw-tolerant state that appears under geometric confinement and may explain the mechanical stability of the reinforcing HAP platelets in bone. Copyright © 2012 Elsevier Ltd. All rights reserved.

Model test study on propagation law of plane stress wave in jointed rock mass under different in-situ stresses

Science.gov (United States)

Dong, Qian

2017-12-01

The study of propagation law of plane stress wave in jointed rock mass under in-situ stress has important significance for safety excavation of underground rock mass engineering. A model test of the blasting stress waves propagating in the intact rock and jointed rock mass under different in-situ stresses was carried out, and the influencing factors on the propagation law, such as the scale of static loads and the number of joints were studied respectively. The results show that the transmission coefficient of intact rock is larger than that of jointed rock mass under the same loading condition. With the increase of confining pressure, the transmission coefficients of intact rock and jointed rock mass both show an trend of increasing first and then decreasing, and the variation of transmission coefficients in intact rock is smaller than that of jointed rock mass. Transmission coefficient of jointed rock mass decreases with the increase of the number of joints under the same loading condition, when the confining pressure is relatively small, the reduction of transmission coefficients decreases with the increasing of the number of joints, and the variation law of the reduction of transmission coefficients is contrary when the confining pressure is large.

Impact of confinement housing on study end-points in the calf model of cryptosporidiosis.

Science.gov (United States)

Graef, Geneva; Hurst, Natalie J; Kidder, Lance; Sy, Tracy L; Goodman, Laura B; Preston, Whitney D; Arnold, Samuel L M; Zambriski, Jennifer A

2018-04-01

Diarrhea is the second leading cause of death in children confinement housing, and Interval Collection (IC), which permits use of box stalls. CFC mimics human challenge model methodology but it is unknown if confinement housing impacts study end-points and if data gathered via this method is suitable for generalization to human populations. Using a modified crossover study design we compared CFC and IC and evaluated the impact of housing on study end-points. At birth, calves were randomly assigned to confinement (n = 14) or box stall housing (n = 9), or were challenged with 5 x 107 C. parvum oocysts, and followed for 10 days. Study end-points included fecal oocyst shedding, severity of diarrhea, degree of dehydration, and plasma cortisol. Calves in confinement had no significant differences in mean log oocysts enumerated per gram of fecal dry matter between CFC and IC samples (P = 0.6), nor were there diurnal variations in oocyst shedding (P = 0.1). Confinement housed calves shed significantly more oocysts (P = 0.05), had higher plasma cortisol (P = 0.001), and required more supportive care (P = 0.0009) than calves in box stalls. Housing method confounds study end-points in the calf model of cryptosporidiosis. Due to increased stress data collected from calves in confinement housing may not accurately estimate the efficacy of chemotherapeutics targeting C. parvum.

Stress gradients in CrN coatings

NARCIS (Netherlands)

Janssen, G.C.A.M.; Tichelaar, F.D.; Visser, C.C.G.

2006-01-01

Stress in hard films is the net sum of tensile stress generated at the grain boundaries, compressive stress due to ion peening, and thermal stress due to the difference in thermal expansion of the coating and substrate. The tensile part due to grain boundaries is thickness dependent. The other two

Models and analyses for inertial-confinement fusion-reactor studies

International Nuclear Information System (INIS)

Bohachevsky, I.O.

1981-05-01

This report describes models and analyses devised at Los Alamos National Laboratory to determine the technical characteristics of different inertial confinement fusion (ICF) reactor elements required for component integration into a functional unit. We emphasize the generic properties of the different elements rather than specific designs. The topics discussed are general ICF reactor design considerations; reactor cavity phenomena, including the restoration of interpulse ambient conditions; first-wall temperature increases and material losses; reactor neutronics and hydrodynamic blanket response to neutron energy deposition; and analyses of loads and stresses in the reactor vessel walls, including remarks about the generation and propagation of very short wavelength stress waves. A discussion of analytic approaches useful in integrations and optimizations of ICF reactor systems concludes the report

Dynamics in geometrical confinement

CERN Document Server

Kremer, Friedrich

2014-01-01

This book describes the dynamics of low molecular weight and polymeric molecules when they are constrained under conditions of geometrical confinement. It covers geometrical confinement in different dimensionalities: (i) in nanometer thin layers or self supporting films (1-dimensional confinement) (ii) in pores or tubes with nanometric diameters (2-dimensional confinement) (iii) as micelles embedded in matrices (3-dimensional) or as nanodroplets.The dynamics under such conditions have been a much discussed and central topic in the focus of intense worldwide research activities within the last two decades. The present book discusses how the resulting molecular mobility is influenced by the subtle counterbalance between surface effects (typically slowing down molecular dynamics through attractive guest/host interactions) and confinement effects (typically increasing the mobility). It also explains how these influences can be modified and tuned, e.g. through appropriate surface coatings, film thicknesses or pore...

Tokamak confinement scaling laws

International Nuclear Information System (INIS)

Connor, J.

1998-01-01

The scaling of energy confinement with engineering parameters, such as plasma current and major radius, is important for establishing the size of an ignited fusion device. Tokamaks exhibit a variety of modes of operation with different confinement properties. At present there is no adequate first principles theory to predict tokamak energy confinement and the empirical scaling method is the preferred approach to designing next step tokamaks. This paper reviews a number of robust theoretical concepts, such as dimensional analysis and stability boundaries, which provide a framework for characterising and understanding tokamak confinement and, therefore, generate more confidence in using empirical laws for extrapolation to future devices. (author)

A bacterial cytotoxin identifies the RhoA exchange factor Net1 as a key effector in the response to DNA damage.

Directory of Open Access Journals (Sweden)

Lina Guerra

Full Text Available BACKGROUND: Exposure of adherent cells to DNA damaging agents, such as the bacterial cytolethal distending toxin (CDT or ionizing radiations (IR, activates the small GTPase RhoA, which promotes the formation of actin stress fibers and delays cell death. The signalling intermediates that regulate RhoA activation and promote cell survival are unknown. PRINCIPAL FINDINGS: We demonstrate that the nuclear RhoA-specific Guanine nucleotide Exchange Factor (GEF Net1 becomes dephosphorylated at a critical inhibitory site in cells exposed to CDT or IR. Expression of a dominant negative Net1 or Net1 knock down by iRNA prevented RhoA activation, inhibited the formation of stress fibers, and enhanced cell death, indicating that Net1 activation is required for this RhoA-mediated responses to genotoxic stress. The Net1 and RhoA-dependent signals involved activation of the Mitogen-Activated Protein Kinase p38 and its downstream target MAPK-activated protein kinase 2. SIGNIFICANCE: Our data highlight the importance of Net1 in controlling RhoA and p38 MAPK mediated cell survival in cells exposed to DNA damaging agents and illustrate a molecular pathway whereby chronic exposure to a bacterial toxin may promote genomic instability.

Anomalous Transport in Natural Fracture Networks Induced by Tectonic Stress

Science.gov (United States)

Kang, P. K.; Lei, Q.; Lee, S.; Dentz, M.; Juanes, R.

2017-12-01

Fluid flow and transport in fractured rock controls many natural and engineered processes in the subsurface. However, characterizing flow and transport through fractured media is challenging due to the high uncertainty and large heterogeneity associated with fractured rock properties. In addition to these "static" challenges, geologic fractures are always under significant overburden stress, and changes in the stress state can lead to changes in the fracture's ability to conduct fluids. While confining stress has been shown to impact fluid flow through fractures in a fundamental way, the impact of confining stress on transportthrough fractured rock remains poorly understood. The link between anomalous (non-Fickian) transport and confining stress has been shown, only recently, at the level of a single rough fracture [1]. Here, we investigate the impact of geologic (tectonic) stress on flow and tracer transport through natural fracture networks. We model geomechanical effects in 2D fractured rock by means of a finite-discrete element method (FEMDEM) [2], which can capture the deformation of matrix blocks, reactivation of pre-existing fractures, and propagation of new cracks, upon changes in the stress field. We apply the model to a fracture network extracted from the geological map of an actual rock outcrop to obtain the aperture field at different stress conditions. We then simulate fluid flow and particle transport through the stressed fracture networks. We observe that anomalous transport emerges in response to confining stress on the fracture network, and show that the stress state is a powerful determinant of transport behavior: (1) An anisotropic stress state induces preferential flow paths through shear dilation; (2) An increase in geologic stress increases aperture heterogeneity that induces late-time tailing of particle breakthrough curves. Finally, we develop an effective transport model that captures the anomalous transport through the stressed fracture

Net metering study of switching effects on electromechanical meters[Report prepared for the Measurement Canada Electricity Net Metering Project

Energy Technology Data Exchange (ETDEWEB)

Van Overberghe, L. [Measurement Canada, London, ON (Canada)

2006-03-03

The feasibility of introducing net metering in the electricity sector was evaluated with particular reference to a project administered by Measurement Canada and Electro-Federation Canada (MicroPower Connect) in collaboration with Natural Resources Canada. The objective of the Measurement Canada Electricity Net Metering Project is to identify and eliminate the barriers introduced by the Electricity and Gas Inspection Act regarding the introduction of net metering. The purpose was to design a device that would allow rotation reversal in a residential electromechanical single phase meter. The device should approximate any fluctuations found in a typical net metering system. A series of tests were conducted to understand the influences, on errors, of forward-to-reverse and reverse-to-forward transitions, specifically to find evidence of error migration and mechanical stress. The project was designed to find and measure the effects of forward reverse switching on an electromechanical meter resulting from a change in energy flow. Twenty metres were calibrated in the forward direction in series from light load to high load. Power factor was not adjustable. Test points were then applied in both the forward and reverse directions. The exercise yielded individual errors which were aggregated to show average found errors after 3,000 transitions. Small shifts in errors were apparent and there was no evidence to support a disk flutter theory. refs., tabs., figs.

Petri Nets

Indian Academy of Sciences (India)

In a computer system, for example, typical discrete events ... This project brought out a series of influential reports on Petri net theory in the mid and late ... Technology became a leading centre for Petri net research and from then on, Petri nets ...

Bond behavior between CFRP sheet and concrete. Part 2. Improvement of bond strength by out-of plane confinement; CFRP sheet to concrete no fuchaku kyodo (2). Mengai kosoku ni yoru fuchaku tairyoku no kaizen

Energy Technology Data Exchange (ETDEWEB)

Sato, Y.; Kimura, K.; Kobatake, Y. [Obayashigumi Research Inst., Tokyo (Japan)

1998-07-30

Behavior of phase at the bond interface between CFRP sheet and concrete is modeled basing on the result of anchoring experiment, and specimens are subjected to finite element analysis to investigate necessary confining stress and anchoring length. Improvement of bonding strength is confirmed by providing lateral sheet for anchoring on the sheet bonded on concrete. The out-of-plane stress acted on the sheet and the out-of-plane displacement during confinement in the experiment are estimated as average 0.5MPa and 0.16mm, respectively. Providing appropriate angle to a two-node joint and setting proper stress/deformation relation of springs crossing each other, the behavior of the phase at the bond interface subjected to out-of-plane confinement is modeled. The maximum bond stress is improved from 4.56MPa to 5.10MPa, and the area where the bond stress becomes larger than 4.56MPa increases from 25mm to 30mm. To anchor the sheet employed in this experiment, larger than 30mm out-of-plane confining stress of 0.5MPa must be provided in the direction of fiber. 16 refs., 17 figs., (plus 1 appended fig.), 3 tabs.

The confinement problem

International Nuclear Information System (INIS)

Seiler, E.

1985-01-01

Confinement of quarks is sometimes taken as some kind of dogma in the contemporary theory of strong interactions - quantum chromo-dynamics (QCD). Scientists should not be content with that. What is meant by ''permanent confinement'' should be formulated more precisely to see whether the theory has this property or not. The author looks at some possible interpretations of ''confinement'' and their shortcomings and then turns to the most widely used rather pragmatic definition based on the somewhat unphysical notion of infinitely heavy external sources. He describes what is known about the problem and tries to bring into focus some aspects that are insufficiently understood in his opinion

Maximal Fluctuations of Confined Actomyosin Gels: Dynamics of the Cell Nucleus.

Science.gov (United States)

Rupprecht, J-F; Singh Vishen, A; Shivashankar, G V; Rao, M; Prost, J

2018-03-02

We investigate the effect of stress fluctuations on the stochastic dynamics of an inclusion embedded in a viscous gel. We show that, in nonequilibrium systems, stress fluctuations give rise to an effective attraction towards the boundaries of the confining domain, which is reminiscent of an active Casimir effect. We apply this generic result to the dynamics of deformations of the cell nucleus, and we demonstrate the appearance of a fluctuation maximum at a critical level of activity, in agreement with recent experiments [E. Makhija, D. S. Jokhun, and G. V. Shivashankar, Proc. Natl. Acad. Sci. U.S.A. 113, E32 (2016)PNASA60027-842410.1073/pnas.1513189113].

The equivalency between logic Petri workflow nets and workflow nets.

Science.gov (United States)

Wang, Jing; Yu, ShuXia; Du, YuYue

2015-01-01

Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented.

The Equivalency between Logic Petri Workflow Nets and Workflow Nets

Science.gov (United States)

Wang, Jing; Yu, ShuXia; Du, YuYue

2015-01-01

Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented. PMID:25821845

Pattern replication by confined dewetting

NARCIS (Netherlands)

Harkema, S.; Schäffer, E.; Morariu, M.D.; Steiner, U

2003-01-01

The dewetting of a polymer film in a confined geometry was employed in a pattern-replication process. The instability of dewetting films is pinned by a structured confining surface, thereby replicating its topographic pattern. Depending on the surface energy of the confining surface, two different

Study of the compressive behavior of short concrete columns confined by fiber reinforced composite

International Nuclear Information System (INIS)

Benzaid, Riad; Mesbah, Habib; Chikh, Nasr eddine

2009-01-01

Fiber reinforced polymer (FRP) composites are very attractive for use in civil engineering applications due to their high strength-to-weight and stiffness-to-weight ratios, corrosion resistance, light weight, and potentially high durability. There is a growing interest in the use of FRP for strengthening of concrete structures such as buildings, bridges, chimneys, etc. This is mainly due to their tailorable performance characteristics, ease of application, and low life cycle costs. The present paper deals with the analysis of experimental results, in terms of load carrying capacity and strains, obtained from tests on circular and square prismatic high strength concrete specimens, strengthened with external E-glass fiber reinforced polymer (GFRP). The parameters considered are the number of composite layers, the corner radius for square shape, and the relation of GFRP confinement with steel reinforcement. All the test specimens were loaded to failure in axial compression and the behavior of the specimens in the axial directions was investigated. The obtained results showed that the efficiency of the confinement was very sensitive to the specimen cross section geometry (circular and square) and the confining stress expressed in the number of the GFRP sheet layers applied. In square cross sections, the stress-strain curve was influenced by the radius to which the corners of the section are rounded off, in order to avoid the breakage of the fibers. (author)

Optical stimulation of the hearing and deaf cochlea under thermal and stress confinement condition

Science.gov (United States)

Schultz, M.; Baumhoff, P.; Kallweit, N.; Sato, M.; Krüger, A.; Ripken, T.; Lenarz, T.; Kral, A.

2014-03-01

There is a controversy, to which extend cochlear stimulation with near infrared laser pulses at a wavelength of 1860 nm is based on optoacoustic stimulation of intact hair cells or -in contrast- is based on direct stimulation of the nerve cells in absence of functional hair cells. Thermal and stress confinement conditions apply, because of the pulse duration range (5 ns, 10 μs-20 ms) of the two lasers used. The dependency of the signal characteristics on pulse peak power and pulse duration was investigated in this study. The compound action potential (CAP) was measured during stimulation of the cochlea of four anaesthetized guinea pigs, which were hearing at first and afterwards acutely deafened using intracochlear neomycin-rinsing. For comparison hydrophone measurements in a water tank were performed to investigate the optoacoustic signals at different laser interaction regimes. With rising pulse peak power CAPs of the hearing animals showed first a threshold, then a positively correlated and finally a saturating dependency. CAPs also showed distinct responses at laser onset and offset separated with the pulse duration. At pulse durations shorter than physiological response times the signals merged. Basically the same signal characteristics were observed in the optoacoustic hydrophone measurements, scaled with the sensitivity and response time of the hydrophone. Taking together the qualitative correspondence in the signal response and the absence of any CAPs in deafened animals our results speak in favor of an optoacoustic stimulation of intact hair cells rather than a direct stimulation of nerve cells.

Stress, social support and problem drinking among women in poverty.

Science.gov (United States)

Mulia, Nina; Schmidt, Laura; Bond, Jason; Jacobs, Laurie; Korcha, Rachael

2008-08-01

Previous studies have found that stress contributes to problem drinking, while social support can buffer its effects. However, these studies are confined largely to middle-class and general populations. We extend what is known by examining how the unique stressors and forms of social support experienced by women in poverty impact alcohol problems over a 4-year time-period. This prospective study used generalized estimating equations (GEE) transition modeling and four annual waves of survey data from 392 American mothers receiving Temporary Assistance for Needy Families (TANF) in a large Northern California county. We examined the effects of neighborhood disorder, stressful life events and economic hardship on psychological distress and problem drinking over time, and whether social support moderated these relationships for women in poverty. Neighborhood disorder and stressful life events increased significantly the risk for problem drinking, largely through their effect on psychological distress. We found little evidence, however, that social support buffers poor women from the effects of these stressors. Women in poverty are exposed to severe, chronic stressors within their communities and immediate social networks which increase vulnerability to psychological distress and problem drinking. The finding that social support does not buffer stress among these women may reflect their high level of exposure to stressors, as well as the hardships and scarce resources within their networks. If the 'private safety net' of the social network fails to provide a strong buffer, more effective environmental interventions that reduce exposure to stressors may be needed to prevent alcohol problems in poor women's lives.

Individualized Stress Detection System, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Given the extended duration of future missions and the isolated, extreme, and confined environments, there is the possibility that stress-related behavioral...

Individualized Stress Detection System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Given the extended duration of future missions and the isolated, extreme and confined environments, there is the possibility that stress-related behavioral...

Coloured Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt

1987-01-01

The author describes a Petri net model, called coloured Petri nets (CP-nets), by means of which it is possible to describe large systems without having to cope with unnecessary details. The author introduces CP-nets and provide a first impression of their modeling power and the suitability...

Net one, net two: the primary care network income statement.

Science.gov (United States)

Halley, M D; Little, A W

1999-10-01

Although hospital-owned primary care practices have been unprofitable for most hospitals, some hospitals are achieving competitive advantage and sustainable practice operations. A key to the success of some has been a net income reporting tool that separates practice operating expenses from the costs of creating and operating a network of practices to help healthcare organization managers, physicians, and staff to identify opportunities to improve the network's financial performance. This "Net One, Net Two" reporting allows operations leadership to be held accountable for Net One expenses and strategic leadership to be held accountable for Net Two expenses.

Fusion energy in an inertial electrostatic confinement device using a magnetically shielded grid

Energy Technology Data Exchange (ETDEWEB)

Hedditch, John, E-mail: john.hedditch@sydney.edu.au; Bowden-Reid, Richard, E-mail: rbow3948@physics.usyd.edu.au; Khachan, Joe, E-mail: joe.khachan@sydney.edu.au [School of Physics, The University of Sydney, Sydney, New South Whales 2006 (Australia)

2015-10-15

Theory for a gridded inertial electrostatic confinement (IEC) fusion system is presented, which shows a net energy gain is possible if the grid is magnetically shielded from ion impact. A simplified grid geometry is studied, consisting of two negatively biased coaxial current-carrying rings, oriented such that their opposing magnetic fields produce a spindle cusp. Our analysis indicates that better than break-even performance is possible even in a deuterium-deuterium system at bench-top scales. The proposed device has the unusual property that it can avoid both the cusp losses of traditional magnetic fusion systems and the grid losses of traditional IEC configurations.

SynechoNET: integrated protein-protein interaction database of a model cyanobacterium Synechocystis sp. PCC 6803

OpenAIRE

Kim, Woo-Yeon; Kang, Sungsoo; Kim, Byoung-Chul; Oh, Jeehyun; Cho, Seongwoong; Bhak, Jong; Choi, Jong-Soon

2008-01-01

Background Cyanobacteria are model organisms for studying photosynthesis, carbon and nitrogen assimilation, evolution of plant plastids, and adaptability to environmental stresses. Despite many studies on cyanobacteria, there is no web-based database of their regulatory and signaling protein-protein interaction networks to date. Description We report a database and website SynechoNET that provides predicted protein-protein interactions. SynechoNET shows cyanobacterial domain-domain interactio...

Full-f gyrokinetic simulation over a confinement time

Energy Technology Data Exchange (ETDEWEB)

Idomura, Yasuhiro, E-mail: idomura.yasuhiro@jaea.go.jp [Japan Atomic Energy Agency, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8587 (Japan)

2014-02-15

A long time ion temperature gradient driven turbulence simulation over a confinement time is performed using the full-f gyrokinetic Eulerian code GT5D. The convergence of steady temperature and rotation profiles is examined, and it is shown that the profile relaxation can be significantly accelerated when the simulation is initialized with linearly unstable temperature profiles. In the steady state, the temperature profile and the ion heat diffusivity are self-consistently determined by the power balance condition, while the intrinsic rotation profile is sustained by complicated momentum transport processes without momentum input. The steady turbulent momentum transport is characterized by bursty non-diffusive fluxes, and the resulting turbulent residual stress is consistent with the profile shear stress theory [Y. Camenen et al., “Consequences of profile shearing on toroidal momentum transport,” Nucl. Fusion 51, 073039 (2011)] in which the residual stress depends not only on the profile shear and the radial electric field shear but also on the radial electric field itself. Based on the toroidal angular momentum conservation, it is found that in the steady null momentum transport state, the turbulent residual stress is cancelled by the neoclassical counterpart, which is greatly enhanced in the presence of turbulent fluctuations.

Dynamics and reactivity of confined water

International Nuclear Information System (INIS)

Musat, R.

2008-01-01

In the context of new sustainable energy sources quest, the nuclear energy remains a key solution. However, with the development of nuclear technology, problems relating to nuclear waste disposal arise; thus, the radiolysis of water in confined media is extremely important with respect to matters related to long time storage of nuclear waste. Studies in model porous media would allow the projection of a confined water radiolysis simulator. A first step in this direction was made by studying the radiolysis of water confined in Vycor and CPG glasses; this study continues the trend set and investigates the effects of confinement in metal materials upon the water radiolysis allowing the understanding of metal - water radiation induced corrosion. A further/complete understanding of the radiolytic process under confinement requires knowledge of the effect of confinement upon the dynamics of confined molecules and on the evolution of the species produced upon ionizing radiation. In this respect, we have used the OH vibrator as a probe of the hydrogen bond network properties and thus investigated the dynamics of confined water using IR time resolved spectroscopy. The evolution of the hydrated electron under confinement was studied on a nano and picosecond time scale using UV pump - visible probe technique and single shot spectroscopy. (author) [fr

Conference summary: Experiments in confinement and plasma-wall interaction and innovative confinement concept

International Nuclear Information System (INIS)

Ninomiya, H.

2005-01-01

This paper summarizes the results presented at the 20th IAEA Fusion Energy Conference 2004 in the sessions of confinement, plasma-wall interaction and innovative confinement concept. The highlights of the presentations are as follows. Long pulse operation with high beta and high bootstrap fraction much longer than the current diffusion time has been achieved. The discharge scenario optimization and its extrapolation towards ITER have progressed remarkably. Significant progress has been made in understanding of global confinement and transport physics. (author)

The effects of confining pressure and stress difference on static fatigue of granite

Science.gov (United States)

Kranz, R. L.

1980-01-01

Samples of Barre granite have been creep tested at room temperature at confining pressures up to 2 kbar. Experimental procedures are described and the results of observations and analysis are presented. It is noted that the effect of pressure is to increase the amount of inelastic deformation the rock can sustain before becoming unstable. It is also shown that this increased deformation is due to longer and more numerous microcracks.

Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

Institute of Scientific and Technical Information of China (English)

FU Xi; ZHOU Guang-Hui

2009-01-01

We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors.Both the quantum wire and conductors are described by a hard-wall confining potential.Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density jTs,xi and jTs,yi(I = x, y, z).We lind that the elements jTs,xx and jTs,yy have a antisymmetrical relation and the element jTs,yz has the same amount level jTs,xx and jTs,yy.We also find a net linear spin current density, which has peaks at the center of quantum wire.The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

The confining trailing string

CERN Document Server

Kiritsis, E; Nitti, F

2014-01-01

We extend the holographic trailing string picture of a heavy quark to the case of a bulk geometry dual to a confining gauge theory. We compute the classical trailing confining string solution for a static as well as a uniformly moving quark. The trailing string is infinitely extended and approaches a confining horizon, situated at a critical value of the radial coordinate, along one of the space-time directions, breaking boundary rotational invariance. We compute the equations for the fluctuations around the classical solutions, which are used to obtain boundary force correlators controlling the Langevin dynamics of the quark. The imaginary part of the correlators has a non-trivial low-frequency limit, which gives rise to a viscous friction coefficient induced by the confining vacuum. The vacuum correlators are used to define finite-temperature dressed Langevin correlators with an appropriate high-frequency behavior.

Brief narrative exposure therapy for posttraumatic stress in Iraqi refugees: a preliminary randomized clinical trial.

Science.gov (United States)

Hijazi, Alaa M; Lumley, Mark A; Ziadni, Maisa S; Haddad, Luay; Rapport, Lisa J; Arnetz, Bengt B

2014-06-01

Many Iraqi refugees suffer from posttraumatic stress. Efficient, culturally sensitive interventions are needed, and so we adapted narrative exposure therapy into a brief version (brief NET) and tested its effects in a sample of traumatized Iraqi refugees. Iraqi refugees in the United States reporting elevated posttraumatic stress (N = 63) were randomized to brief NET or waitlist control conditions in a 2:1 ratio; brief NET was 3 sessions, conducted individually, in Arabic. Positive indicators (posttraumatic growth and well-being) and symptoms (posttraumatic stress, depressive, and somatic) were assessed at baseline and 2- and 4-month follow-up. Treatment participation (95.1% completion) and study retention (98.4% provided follow-up data) were very high. Significant condition by time interactions showed that those receiving brief NET had greater posttraumatic growth (d = 0.83) and well-being (d = 0.54) through 4 months than controls. Brief NET reduced symptoms of posttraumatic stress (d = -0.48) and depression (d = -0.46) more, but only at 2 months; symptoms of controls also decreased from 2 to 4 months, eliminating condition differences at 4 months. Three sessions of brief NET increased growth and well-being and led to symptom reduction in highly traumatized Iraqi refugees. This preliminary study suggests that brief NET is both acceptable and potentially efficacious in traumatized Iraqi refugees. Copyright © 2014 International Society for Traumatic Stress Studies.

Dynamic mechanical properties and anisotropy of synthetic shales with different clay minerals under confining pressure

Science.gov (United States)

Gong, Fei; Di, Bangrang; Wei, Jianxin; Ding, Pinbo; Shuai, Da

2018-03-01

The presence of clay minerals can alter the elastic behaviour of reservoir rocks significantly as the type of clay minerals, their volume and distribution, and their orientation control the shale's intrinsic anisotropic behaviours. Clay minerals are the most abundant materials in shale, and it has been proven extremely difficult to measure the elastic properties of natural shale by means of a single variable (in this case, the type of clay minerals), due to the influences of multiple factors, including water, TOC content and complex mineral compositions. We used quartz, clay (kaolinite, illite and smectite), carbonate and kerogen extract as the primary materials to construct synthetic shale with different clay minerals. Ultrasonic experiments were conducted to investigate the anisotropy of velocity and mechanical properties in dry synthetic and natural shale as a function of confining pressure. Velocities in synthetic shale are sensitive to the type of clay minerals, possibly due to the different structures of the clay minerals. The velocities increase with confining pressure and show higher rate of velocity increase at low pressures, and P-wave velocity is usually more sensitive than S-wave velocity to confining pressure according to our results. Similarly, the dynamic Young's modulus and Poisson's ratio increase with applied pressure, and the results also reveal that E11 is always larger than E33 and ν31 is smaller than ν12. Velocity and mechanical anisotropy decrease with increasing stress, and are sensitive to stress and the type of clay minerals. However, the changes of mechanical anisotropy with applied stress are larger compared with the velocity anisotropy, indicating that mechanical properties are more sensitive to the change of rock properties.

Measuring and predicting the dynamic effects of a confined thin metal plate pulse heated into the liquid-vapor regime

International Nuclear Information System (INIS)

Baxter, R.C.

1977-01-01

The dynamic response of a confined thin layer of lead heated rapidly and uniformly to a supercritical state was investigated. Lead targets 0.025 mm and 0.05 mm thick were contained between a thin titanium tamping layer and a thick layer of fused quartz with several different gap widths between the lead and the confining surfaces. After being heated by an electron beam for about 50 ns, lead specimens expanded to a state of approximately half liquid and half vapor. Measurements of the stress in the quartz and the velocity of the tamper produced by the expanding lead were compared with one dimensional hydrodynamic computer program predictions. Measured and predicted peak stresses in the quartz for no gaps were approximately 12 kilobars and agreed within one kilobar. Peak stresses decreased rapidly with gap size to values, at 0.02 mm gaps, of about one kilobar for the 0.025 mm lead targets and five kilobars for the 0.05 mm targets. These values were confirmed by measurements. Predictions and measurements of tamper velocity (momentum) were within 10% only when the lead and confining walls were in close contact. The observed velocities for even very small gaps were substantially below predictions. These differences are attributed primarily to separation of the liquid and vapor phases during the expansion

A Review of Quantum Confinement

Science.gov (United States)

Connerade, Jean-Patrick

2009-12-01

A succinct history of the Confined Atom problem is presented. The hydrogen atom confined to the centre of an impenetrable sphere counts amongst the exactly soluble problems of physics, alongside much more noted exact solutions such as Black Body Radiation and the free Hydrogen atom in absence of any radiation field. It shares with them the disadvantage of being an idealisation, while at the same time encapsulating in a simple way particular aspects of physical reality. The problem was first formulated by Sommerfeld and Welker [1]—henceforth cited as SW—in connection with the behaviour of atoms at very high pressures, and the solution was published on the occasion of Pauli's 60th birthday celebration. At the time, it seemed that there was not much other connection with physical reality beyond a few simple aspects connected to the properties of atoms in solids, for which more appropriate models were soon developed. Thus, confined atoms attracted little attention until the advent of the metallofullerene, which provided the first example of a confined atom with properties quite closely related to those originally considered by SW. Since then, the problem has received much more attention, and many more new features of quantum confinement, quantum compression, the quantum Faraday cage, electronic reorganisation, cavity resonances, etc have been described, which are relevant to real systems. Also, a number of other situations have been uncovered experimentally to which quantum confinement is relevant. Thus, studies of the confined atom are now more numerous, and have been extended both in terms of the models used and the systems to which they can be applied. Connections to thermodynamics are explored through the properties of a confined two-level atom adapted from Einstein's celebrated model, and issues of dynamical screening of electromagnetic radiation by the confining shell are discussed in connection with the Faraday cage produced by a confining conducting shell

A Review of Quantum Confinement

International Nuclear Information System (INIS)

Connerade, Jean-Patrick

2009-01-01

A succinct history of the Confined Atom problem is presented. The hydrogen atom confined to the centre of an impenetrable sphere counts amongst the exactly soluble problems of physics, alongside much more noted exact solutions such as Black Body Radiation and the free Hydrogen atom in absence of any radiation field. It shares with them the disadvantage of being an idealisation, while at the same time encapsulating in a simple way particular aspects of physical reality. The problem was first formulated by Sommerfeld and Welker - henceforth cited as SW - in connection with the behaviour of atoms at very high pressures, and the solution was published on the occasion of Pauli's 60th birthday celebration. At the time, it seemed that there was not much other connection with physical reality beyond a few simple aspects connected to the properties of atoms in solids, for which more appropriate models were soon developed. Thus, confined atoms attracted little attention until the advent of the metallofullerene, which provided the first example of a confined atom with properties quite closely related to those originally considered by SW. Since then, the problem has received much more attention, and many more new features of quantum confinement, quantum compression, the quantum Faraday cage, electronic reorganisation, cavity resonances, etc have been described, which are relevant to real systems. Also, a number of other situations have been uncovered experimentally to which quantum confinement is relevant. Thus, studies of the confined atom are now more numerous, and have been extended both in terms of the models used and the systems to which they can be applied. Connections to thermodynamics are explored through the properties of a confined two-level atom adapted from Einstein's celebrated model, and issues of dynamical screening of electromagnetic radiation by the confining shell are discussed in connection with the Faraday cage produced by a confining conducting shell. The

Evolution of Cement-Casing Interface in Wellbore Microannuli under Stress

Science.gov (United States)

Matteo, E. N.; Gomez, S. P.; Sobolik, S. R.; Taha, M. R.; Stormont, J.

2017-12-01

Laboratory tests measured the compressibility and flow characteristics of wellbore microannuli. Specimens, consisting of a cement sheath cast on a steel casing with microannuli, were subjected to confining pressures and casing pressures in a pressure vessel that allows simultaneous measurement of gas flow along the axis of the specimen. The flow was interpreted as the hydraulic aperture of the microannuli. We found the hydraulic aperture decreases as confining stress is increased. The larger the initial hydraulic aperture, the more it decreases as confining stress increases. The changes in measured hydraulic aperture correspond to changes of many orders of magnitude in permeability of the wellbore system, suggesting that microannulus response to stress changes may have a significant impact on estimates of wellbore leakage. A finite element model of a wellbore system was developed that included elements representing the microannulus that incorporated the hyperbolic joint model. The thickness of the microannulus elements is equivalent to the hydraulic aperture. The calculated normal stress across the microannulus used in the numerical implementation was found to be similar to the applied confining pressure in the laboratory tests. The microannulus elements were found to reasonably reproduce laboratory behavior during loading from confining pressure increases. The calculated microannulus response to internal casing pressure changes was less stiff than measured, which may be due to hardening of the microannulus during testing. In particular, the microannulus model could be used to estimate CO2 leakage as a function of formation stress changes and/or displacements, or loading from casing expansion or contraction during wellbore operations. Recommendations for future work include an application of the joint model with a thermally active large-scale reservoir coupled with pore pressure caused by dynamic CO2 injection and subsequent microannulus region affects. Sandia

Parameters estimation of Drucker-Prager plasticity criteria for steel confined circular concrete columns in compression

Directory of Open Access Journals (Sweden)

Al-Kutti Walid A.

2018-01-01

Full Text Available This paper explores the possibility to use Drucker-Prager model in Steel-Concrete composite section. Numerical simulation was conducted using finite element package to simulate the steel-concrete composite section subjected to uniaxial compressive loading. After calibration with experimental study, parametric study was conducted to evaluate the effect of the friction angle and the cohesion constant c on the stress-strain curve of composite section. Empirical relationship between the friction angle and the confined concrete compressive strength was developed and a range of cohesion constant c between 5-10 MPa was suggested for confined concrete strength range of 25 to 100 MPa, respectively.

The effect of deformation on two-phase flow through proppant-packed fractured shale samples: A micro-scale experimental investigation

Science.gov (United States)

Arshadi, Maziar; Zolfaghari, Arsalan; Piri, Mohammad; Al-Muntasheri, Ghaithan A.; Sayed, Mohammed

2017-07-01

We present the results of an extensive micro-scale experimental investigation of two-phase flow through miniature, fractured reservoir shale samples that contained different packings of proppant grains. We investigated permeability reduction in the samples by conducting experiments under a wide range of net confining pressures. Three different proppant grain distributions in three individual fractured shale samples were studied: i) multi-layer, ii) uniform mono-layer, and iii) non-uniform mono-layer. We performed oil-displacing-brine (drainage) and brine-displacing-oil (imbibition) flow experiments in the proppant packs under net confining pressures ranging from 200 to 6000 psi. The flow experiments were performed using a state-of-the-art miniature core-flooding apparatus integrated with a high-resolution, X-ray microtomography system. We visualized fluid occupancies, proppant embedment, and shale deformation under different flow and stress conditions. We examined deformation of pore space within the proppant packs and its impact on permeability and residual trapping, proppant embedment due to changes in net confining stress, shale surface deformation, and disintegration of proppant grains at high stress conditions. In particular, geometrical deformation and two-phase flow effects within the proppant pack impacting hydraulic conductivity of the medium were probed. A significant reduction in effective oil permeability at irreducible water saturation was observed due to increase in confining pressure. We propose different mechanisms responsible for the observed permeability reduction in different fracture packings. Samples with dissimilar proppant grain distributions showed significantly different proppant embedment behavior. Thinner proppant layer increased embedment significantly and lowered the onset confining pressure of embedment. As confining stress was increased, small embedments caused the surface of the shale to fracture. The produced shale fragments were

Energy Evolution Mechanism and Confining Pressure Effect of Granite under Triaxial Loading-Unloading Cycles

Science.gov (United States)

Wang, Hao; Miao, Sheng-jun

2018-05-01

Rock mass undergoes some deformational failure under the action of external loads, a process known to be associated with energy dissipation and release. A triaxial loading-unloading cycle test was conducted on granite in order to investigate the energy evolution pattern of rock mass under the action of external loads. The study results demonstrated: (1) The stress peaks increased by 50% and 22% respectively and the pre-peak weakening became more apparent in the ascending process of the confining pressure from 10MPa to 30MPa; the area enclosed by the hysteresis loop corresponding to 30MPa diminished by nearly 60% than that corresponding to 10MPa, indicating a higher confining pressure prohibits rock mass from plastic deformation and shifts strain toward elastic deformation. (2) In the vicinity of the strength limit, the slope of dissipation energy increased to 1.6 from the original 0.7 and the dissipation energy grew at an accelerating rate, demonstrating stronger propagation and convergence of internal cracks. (3) At a pressure of 70% of the stress peak, the elastic energy of the granite accounted for 88% of its peak value, suggesting the rock mechanical energy from the outside mostly changes into the elastic energy inside the rock, with little energy loss.(4) Prior to test specimen failure, the axial bearing capacity dropped with a decreasing confining pressure in an essentially linear way, and the existence of confirming pressure played a role in stabilizing the axial bearing capacity.

Psychological and behavioral changes during confinement in a 520-day simulated interplanetary mission to mars.

Directory of Open Access Journals (Sweden)

Mathias Basner

Full Text Available Behavioral health risks are among the most serious and difficult to mitigate risks of confinement in space craft during long-duration space exploration missions. We report on behavioral and psychological reactions of a multinational crew of 6 healthy males confined in a 550 m(3 chamber for 520 days during the first Earth-based, high-fidelity simulated mission to Mars. Rest-activity of crewmembers was objectively measured throughout the mission with wrist-worn actigraphs. Once weekly throughout the mission crewmembers completed the Beck Depression Inventory-II (BDI-II, Profile of Moods State short form (POMS, conflict questionnaire, the Psychomotor Vigilance Test (PVT-B, and series of visual analogue scales on stress and fatigue. We observed substantial inter-individual differences in the behavioral responses of crewmembers to the prolonged mission confinement and isolation. The crewmember with the highest average POMS total mood disturbance score throughout the mission also reported symptoms of depression in 93% of mission weeks, which reached mild-to-moderate levels in >10% of mission weeks. Conflicts with mission control were reported five times more often than conflicts among crewmembers. Two crewmembers who had the highest ratings of stress and physical exhaustion accounted for 85% of the perceived conflicts. One of them developed a persistent sleep onset insomnia with ratings of poor sleep quality, which resulted in chronic partial sleep deprivation, elevated ratings of daytime tiredness, and frequent deficits in behavioral alertness. Sleep-wake timing was altered in two other crewmembers, beginning in the first few months of the mission and persisting throughout. Two crewmembers showed neither behavioral disturbances nor reports of psychological distress during the 17-month period of mission confinement. These results highlight the importance of identifying behavioral, psychological, and biological markers of characteristics that

Confinement at large-N

International Nuclear Information System (INIS)

Klinkhamer, F.R.

1985-06-01

Recent numerical results indicate that QCD in the limit of an infinite number (N) of colors also has confinement and moreover that it looks rather similar to normal QCD with N = 3 colors. This imposes severe restrictions on what the mechanism of confinement can be

Net Rotation of the Lithosphere in Mantle Convection Models with Self-consistent Plate Generation

Science.gov (United States)

Gerault, M.; Coltice, N.

2017-12-01

Lateral variations in the viscosity structure of the lithosphere and the mantle give rise to a discordant motion between the two. In a deep mantle reference frame, this motion is called the net rotation of the lithosphere. Plate motion reconstructions, mantle flow computations, and inferences from seismic anisotropy all indicate some amount of net rotation using different mantle reference frames. While the direction of rotation is somewhat consistent across studies, the predicted amplitudes range from 0.1 deg/Myr to 0.3 deg/Myr at the present-day. How net rotation rates could have differed in the past is also a subject of debate and strong geodynamic arguments are missing from the discussion. This study provides the first net rotation calculations in 3-D spherical mantle convection models with self-consistent plate generation. We run the computations for billions of years of numerical integration. We look into how sensitive the net rotation is to major tectonic events, such as subduction initiation, continental breakup and plate reorganisations, and whether some governing principles from the models could guide plate motion reconstructions. The mantle convection problem is solved with the finite volume code StagYY using a visco-pseudo-plastic rheology. Mantle flow velocities are solely driven by buoyancy forces internal to the system, with free slip upper and lower boundary conditions. We investigate how the yield stress, the mantle viscosity structure and the properties of continents affect the net rotation over time. Models with large lateral viscosity variations from continents predict net rotations that are at least threefold faster than those without continents. Models where continents cover a third of the surface produce net rotation rates that vary from nearly zero to over 0.3 deg/Myr with rapide increase during continental breakup. The pole of rotation appears to migrate along no particular path. For all models, regardless of the yield stress and the

Shear-Alfven dynamics of toroidally confined plasmas. Part A

International Nuclear Information System (INIS)

Hazeltine, R.D.; Meiss, J.D.

1984-08-01

Recent developments in the stability theory of toroidally confined plasmas are reviewed, with the intention of providing a picture comprehensible to non-specialists. The review considers a class of low-frequency, electromagnetic disturbances that seem especially pertinent to modern high-temperature confinement experiments. It is shown that such disturbances are best unified and understood through consideration of a single, exact fluid moment: the shear-Alfven law. Appropriate versions of this law and its corresponding closure relations are derived - essentially from first principles - and applied in a variety of mostly, but not exclusively, linear contexts. Among the specific topics considered are: flux coordinates (including Hamada coordinates), the Newcomb solubility condition. Shafranov geometry, magnetic island evolution, reduced MHD and its generalizations, drift-kinetic electron response, classical tearing, twisting, and kink instabilities, pressure-modified tearing instability (Δ-critical), collisionless and semi-collisional tearing modes, the ballooning representation in general geometry, ideal ballooning instability, Mercier criterion, near-axis expansions, the second stability region, and resistive and kinetic ballooning modes. The fundamental importance of toroidal topology and curvature is stressed

Early resistance change and stress/electromigrationmodeling in aluminium interconnects

NARCIS (Netherlands)

Petrescu, V.; Mouthaan, A.J.; Schoenmaker, W.

1997-01-01

A complete description for early resistance change and two dimensional simulation of mechanical stress evolution in confined Al interconnects, related to the electromigration, is given in this paper. The model, combines the stress/ vacancy concentration evolution with the early resistance change of

Block copolymer morphologies confined by square-shaped particle: Hard and soft confinement

International Nuclear Information System (INIS)

Zhang Qiyi; Yang Wenyan; Hu Kaiyan

2016-01-01

The self-assembly of diblock copolymers confined around one square-shaped particle is studied systematically within two-dimensional self-consistent field theory (SCFT). In this model, we assume that the thin block copolymer film is confined in the vicinity of a square-shaped particle by a homopolymer melt, which is equivalent to the poor solvents. Multiple sequences of square-shaped particle-induced copolymer aggregates with different shapes and self-assembled internal morphologies are predicted as functions of the particle size, the structural portion of the copolymer, and the volume fraction of the copolymer. A rich variety of aggregates are found with complex internal self-assembled morphologies including complex structures of the vesicle, with one or several inverted micelle surrounded by the outer monolayer with the particle confined in the core. These results demonstrate that the assemblies of diblock copolymers formed around the square-shaped particle in poor solvents are of immediate interest to the assembly of copolymer and the morphology of biomembrane in the confined environment, as well as to the transitions of vesicles to micelles. (paper)

Alternate fusion -- continuous inertial confinement

International Nuclear Information System (INIS)

Barnes, D.C.; Turner, L.; Nebel, R.A.

1993-01-01

The authors argue that alternate approaches to large tokamak confinement are appropriate for fusion applications if: (1) They do not require magnetic confinement of a much higher quality than demonstrated in tokamaks; (2) Their physics basis may be succinctly stated and experimentally tested; (3) They offer near-term applications to important technical problems; and (4) Their cost to proof-of-principle is low enough to be consistent with current budget realities. An approach satisfying all of these criteria is presented. Fusion systems based on continuous inertial confinement are described. In these approaches, the inertia of a nonequilibrium plasma is used to produce local concentrations of plasma density in space and/or time. One implementation (inertial electrostatic confinement) which has been investigated both experimentally and theoretically uses a system of electrostatic grids to accelerate plasma ions toward a spherical focus. This system produced a steady 2 x 10 10 D-T neutrons/second with an overall fusion gain of 10 -5 in a sphere of about 9 cm radius. Recent theoretical developments show how to raise the fusion gain to order unity or greater by replacing the internal grids by a combination of applied magnetic and electrostatic fields. In these approaches, useful thermonuclear conditions may be produced in a system as small as a few mm radius. Confinement is that of a nonneutralized plasma. A pure electron plasma with a radial beam velocity distribution is absolutely confined by an applied Penning trap field. Spherical convergence of the confined electrons forms a deep virtual cathode near r = 0, in which thermonuclear ions are absolutely confined at useful densities. The authors have examined the equilibrium, stability, and classical relaxation of such systems, and obtained many positive physics results. Equilibria exist for both pure electron and partially charge-neutralized systems with arbitrarily high core-plasma densities

Stress-Dilatancy of Cambria Sand for Triaxial Tests at High Pressures

Science.gov (United States)

Szypcio, Zenon

2017-12-01

In this paper, the stress-dilatancy relationship of Cambria sand for drained triaxial compression and extension tests at high stress level is investigated. The stress dilatancy relationship is obtained by use of frictional state theory and experimental tests data published in literature. It is shown that stress-dilatancy relationship is bilinear, described by three parameters of frictional state theory: critical frictional angle and two other parameters. It is accepted that critical friction angle is independent of confining pressure. The two additional parameters are strongly dependent on confining pressure and different for initial and advanced stages. The point at which the values of these parameters change is termed as Transformation Shear Point. This point is not simply visible either in stress ratio-strain or the volume strain-shear strain relationship which are traditionally shown in soil mechanics papers. Transformation Shear Point is very characteristic in stress ratio-plastic dilatancy plane. Thus, stress ratio- plastic dilatancy is very important for describing stress-strain behaviour of soils. The relationship shown in the paper can be used in soil modelling in the future.

Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

International Nuclear Information System (INIS)

Fu Xi; Zhou Guanghui

2009-01-01

We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors. Both the quantum wire and conductors are described by a hard-wall confining potential. Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density j s,xi T and j s,yi T (i = x, y, z). We find that the elements j T s,xx and j T s,yy have a antisymmetrical relation and the element j T s,yz has the same amount level as j s,xx T and j s,yy T . We also find a net linear spin current density, which has peaks at the center of quantum wire. The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

Impact of rotational-transform profile control on plasma confinement and stability in CHS

International Nuclear Information System (INIS)

Toi, K.; Morisaki, T.; Sakakibara, S.

1994-08-01

In neutral beam heated plasmas of CHS, which is a low aspect-ration heliotron/torsatron device, the effect of rotational transform (ι) profile shape on plasma confinement and stability is studied by inducing a net plasma current (Ip). In the case that the external ι is increased by Ip, very rapid H-mode transition (within ∼0.2 ms) is observed at the thresholds of Ip and heating power, having all characteristics found in the tokamak H-mode. There is no obvious difference in the H-mode characteristics between deuterium and hydrogen plasmas. In the opposite case that the external ι is decreased by reversing Ip, the H-mode transition is not observed. (author)

Application of deconvolution interferometry with both Hi-net and KiK-net data

Science.gov (United States)

Nakata, N.

2013-12-01

Application of deconvolution interferometry to wavefields observed by KiK-net, a strong-motion recording network in Japan, is useful for estimating wave velocities and S-wave splitting in the near surface. Using this technique, for example, Nakata and Snieder (2011, 2012) found changed in velocities caused by Tohoku-Oki earthquake in Japan. At the location of the borehole accelerometer of each KiK-net station, a velocity sensor is also installed as a part of a high-sensitivity seismograph network (Hi-net). I present a technique that uses both Hi-net and KiK-net records for computing deconvolution interferometry. The deconvolved waveform obtained from the combination of Hi-net and KiK-net data is similar to the waveform computed from KiK-net data only, which indicates that one can use Hi-net wavefields for deconvolution interferometry. Because Hi-net records have a high signal-to-noise ratio (S/N) and high dynamic resolution, the S/N and the quality of amplitude and phase of deconvolved waveforms can be improved with Hi-net data. These advantages are especially important for short-time moving-window seismic interferometry and deconvolution interferometry using later coda waves.

A new confined high pressure rotary shear apparatus: preliminary results

Science.gov (United States)

Faulkner, D.; Coughlan, G.; Bedford, J. D.

2017-12-01

The frictional properties of fault zone materials, and their evolution during slip, are of paramount importance for determining the earthquake mechanics of large tectonic faults. Friction is a parameter that is difficult to determine from seismological methods so much of our understanding comes from experiment. Rotary shear apparatuses have been widely used in experimental studies to elucidate the frictional properties of faults under realistic earthquake slip velocities (0.1-10 m/s) and displacements (>20 m). However one technical limitation of rotary shear experiments at seismic slip rates has been the lack of confinement. This has led to a limit on the normal stress (due to the strength of the forcing blocks) and also a lack of control of measurements of the pore fluid pressure. Here we present the first preliminary results from a rotary shear apparatus that has been developed to attempt to address this issue. The new fully confined ring shear apparatus has a fast-acting servo-hydraulic confining pressure system of up to 200 MPa and a servo-controlled upstream and downstream pore pressure system of up to 200 MPa. Displacement rates of 0.01μ/s to 2 m/s can be achieved. Fault gouge samples can therefore be sheared at earthquake speed whilst being subject to pressures typically associated with the depth of earthquake nucleation.

Elmo bumpy square plasma confinement device

Science.gov (United States)

Owen, L.W.

1985-01-01

The invention is an Elmo bumpy type plasma confinement device having a polygonal configuration of closed magnet field lines for improved plasma confinement. In the preferred embodiment, the device is of a square configuration which is referred to as an Elmo bumpy square (EBS). The EBS is formed by four linear magnetic mirror sections each comprising a plurality of axisymmetric assemblies connected in series and linked by 90/sup 0/ sections of a high magnetic field toroidal solenoid type field generating coils. These coils provide corner confinement with a minimum of radial dispersion of the confined plasma to minimize the detrimental effects of the toroidal curvature of the magnetic field. Each corner is formed by a plurality of circular or elliptical coils aligned about the corner radius to provide maximum continuity in the closing of the magnetic field lines about the square configuration confining the plasma within a vacuum vessel located within the various coils forming the square configuration confinement geometry.

The influence of the anisotropic stress state on the intermediate strain properties of granular material

KAUST Repository

Goudarzy, M.

2017-07-20

This paper shows the effect of anisotropic stress state on intermediate strain properties of cylindrical samples containing spherical glass particles. Tests were carried out with the modified resonant column device available at Ruhr-Universität Bochum. Dry samples were subjected to two anisotropic stress states: (a) cell pressure, σ′h, constant and vertical stress, σ′v, increased (stress state GB-I) and (b) σ′v/σ′h equal to 2 (stress state GB-II). The experimental results revealed that the effect of stress state GB-II on the modulus and damping ratio was more significant and obvious than stress state GB-I. The effect of the anisotropic stress state was explained through the impact of confining pressure and anisotropic stress components on the stiffness and damping ratio. The results showed that: (a) G(γ) increased, η(γ) decreased and their strain non-linearity decreased with an increase in the confining pressure component σ′vσ′h; (b) G(γ) decreased, η(γ) increased and their strain non-linearity increased with an increase in the anisotropic stress component, σ′v/σ′h. The analysis of results revealed that reference shear strain was also affected by anisotropic stress state. Therefore, an empirical relationship was developed to predict the reference shear strain, as a function of confining pressure and anisotropic stress components. Additionally, the damping ratio was written as a function of the minimum damping ratio and the reference shear strain.

Fault condition stress analysis of NET 16 TF coil model

International Nuclear Information System (INIS)

Jong, C.T.J.

1992-04-01

As part of the design process of the NET/ITER toroidal field coils (TFCs), the mechanical behaviour of the magnetic system under fault conditions has to be analysed in some detail. Under fault conditions, either electrical or mechanical, the magnetic loading of the coils becomes extreme and further mechanical failure of parts of the overall structure might occur (e.g. failure of the coil, gravitational support, intercoil structure). The mechanical behaviour of the magnetic system under fault conditions has been analysed with a finite element model of the complete TFC system. The analysed fault conditions consist of: a thermal fault, electrical faults and mechanical faults. The mechanical faults have been applied simultaneously with an electrical fault. This report described the work carried out to create the finite element model of 16 TFCs and contains an extensive presentation of the results, obtained with this model, of a normal operating condition analysis and 9 fault condition analyses. Chapter 2-5 contains a detailed description of the finite element model, boundary conditions and loading conditions of the analyses made. Chapters 2-4 can be skipped if the reader is only interested in results. To understand the results presented chapter 6 is recommended, which contains a detailed description of all analysed fault conditions. The dimensions and geometry of the model correspond to the status of the NET/ITER TFC design of May 1990. Compared with previous models of the complete magnetic system, the finite element model of 16 TFCs is 'detailed', and can be used for linear elastic analysis with faulted loads. (author). 8 refs.; 204 figs.; 134 tabs

Generating equilateral random polygons in confinement III

International Nuclear Information System (INIS)

Diao, Y; Ernst, C; Montemayor, A; Ziegler, U

2012-01-01

In this paper we continue our earlier studies (Diao et al 2011 J. Phys. A: Math. Theor. 44 405202, Diao et al J. Phys. A: Math. Theor. 45 275203) on the generation methods of random equilateral polygons confined in a sphere. The first half of this paper is concerned with the generation of confined equilateral random walks. We show that if the selection of a vertex is uniform subject to the position of its previous vertex and the confining condition, then the distributions of the vertices are not uniform, although there exists a distribution such that if the initial vertex is selected following this distribution, then all vertices of the random walk follow this same distribution. Thus in order to generate a confined equilateral random walk, the selection of a vertex cannot be uniform subject to the position of its previous vertex and the confining condition. We provide a simple algorithm capable of generating confined equilateral random walks whose vertex distribution is almost uniform in the confinement sphere. In the second half of this paper we show that any process generating confined equilateral random walks can be turned into a process generating confined equilateral random polygons with the property that the vertex distribution of the polygons approaches the vertex distribution of the walks as the polygons get longer and longer. In our earlier studies, the starting point of the confined polygon is fixed at the center of the sphere. The new approach here allows us to move the starting point of the confined polygon off the center of the sphere. (paper)

Confining jackets for concrete cylinders using NiTiNb and NiTi shape memory alloy wires

Energy Technology Data Exchange (ETDEWEB)

Choi, Eunsoo; Yoon, Soon-Jong [Department of Civil Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Nam, Tae-Hyun [School of Materials Science and Engineering and ERI, Gyeongsang National University, Jinju, Gyeongnam 600-701 (Korea, Republic of); Cho, Sun-Kyu [School of Civil Engineering, Seoul National University of Technology, Seoul 139-743 (Korea, Republic of); Park, Joonam, E-mail: eunsoochoi@hongik.ac.k [Department of Railroad Structure Research, Korea Railroad Research Institute, Uiwang 437-050, Korea (Korea, Republic of)

2010-05-01

This study used prestrained NiTiNb and NiTi shape memory alloy (SMA) wires to confine concrete cylinders. The recovery stress of the wires was measured with respect to the maximal prestrain of the wires. SMA wires were preelongated during the manufacturing process and then wrapped around concrete cylinders of 150 mmx300 mm ({phi}xL). Unconfined concrete cylinders were tested for compressive strength and the results were compared to those of cylinders confined by SMA wires. NiTiNb SMA wires increased the compressive strength and ductility of the cylinders due to the confining effect. NiTiNb wires were found to be more effective in increasing the peak strength of the cylinders and dissipating energy than NiTi wires. This study showed the potential of the proposed method to retrofit reinforced concrete columns using SMA wires to protect them from earthquakes.

Phenomenology and theory of confinement

International Nuclear Information System (INIS)

Pervushin, V.N.

1987-01-01

Phenomenological and theoretical arguments of the separation of the hadronization dynamics from confinement and the idea of the ''kinematic'' confinement are discussed. The recent theory contains results which point out that the Wilson criterion and the confinement potentials are not sufficient for explaining the phenomenological confinement in the sense of zero color amplitudes or Green functions. However, these potentials well explain the hadron spectrum and spontaneous breaking of chiral symmetry, i.e., the hadronization dynamics. The ''kinematic'' confinement can be explained by the topological degeneration of all color-particle physical states in QCD. This degeneration arises if the theory is quantized by explicitly solving the gauge and dynamic constraints: all color states are defined up to gauge(phase) factors describing the map of the three-dimensional space onto SU(3) c -group (π 3 (SU(3) c =Z). The total probability of the color particle generation is equal to zero due to the destructive interference of these phase factors. As a result, in QCD there remains only a hadron sector used in the phenomenology

On confinement and duality

Energy Technology Data Exchange (ETDEWEB)

Strassler, M J [University of Pennsylvania, Philadelphia, PA (United States)

2002-05-15

Confinement in four-dimensional gauge theories is considered from several points of view. General features are discussed, and the mechanism of confinement is investigated. Dualities between field theories, and duality between field theory and string theory, are both put to use. In these lectures I have given an overview of some of the key ideas underlying confinement as a property of field theory, and now, of string theory as well. This is a tiny fraction of what field theory (and now string theory) is capable of, and we are still uncovering new features on a monthly basis. In fact, most field theories do not have confinement, for reasons entirely different from those of QCD. Many become nontrivial conformal field theories at low energy. Others become composite, weakly-coupled gauge theories. Dualities of many stripes are found everywhere. Ordinary dimensional analysis in string theory is totally wrong in the regime where it looks like weakly-coupled field theory, and ordinary dimensional analysis in field theory is totally wrong in the regime where it looks like weakly-coupled supergravity.

ATR confinement leakage determination

International Nuclear Information System (INIS)

Kuan, P.; Buescher, B.J.

1998-01-01

The air leakage rate from the Advanced Test Reactor (ATR) confinement is an important parameter in estimating hypothesized accidental releases of radiation to the environment. The leakage rate must be determined periodically to assure that the confinement has not degraded with time and such determination is one of the technical safety requirements of ATR operation. This paper reviews the methods of confinement leakage determination and presents an analysis of leakage determination under windy conditions, which can complicate the interpretation of the determined leakage rates. The paper also presents results of analyses of building air exchange under windy conditions. High wind can enhance air exchange and this could increase the release rates of radioisotopes following an accident

Generating equilateral random polygons in confinement

International Nuclear Information System (INIS)

Diao, Y; Ernst, C; Montemayor, A; Ziegler, U

2011-01-01

One challenging problem in biology is to understand the mechanism of DNA packing in a confined volume such as a cell. It is known that confined circular DNA is often knotted and hence the topology of the extracted (and relaxed) circular DNA can be used as a probe of the DNA packing mechanism. However, in order to properly estimate the topological properties of the confined circular DNA structures using mathematical models, it is necessary to generate large ensembles of simulated closed chains (i.e. polygons) of equal edge lengths that are confined in a volume such as a sphere of certain fixed radius. Finding efficient algorithms that properly sample the space of such confined equilateral random polygons is a difficult problem. In this paper, we propose a method that generates confined equilateral random polygons based on their probability distribution. This method requires the creation of a large database initially. However, once the database has been created, a confined equilateral random polygon of length n can be generated in linear time in terms of n. The errors introduced by the method can be controlled and reduced by the refinement of the database. Furthermore, our numerical simulations indicate that these errors are unbiased and tend to cancel each other in a long polygon. (paper)

Net Neutrality

DEFF Research Database (Denmark)

Savin, Andrej

2017-01-01

Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

Progressive friction mobilization and enhanced Janssen's screening in confined granular rafts

Science.gov (United States)

Saavedra V., Oscar; Elettro, Hervé; Melo, Francisco

2018-04-01

Confined two-dimensional assemblies of floating particles, known as granular rafts, are prone to develop a highly nonlinear response under compression. Here we investigate the transition to the friction-dominated jammed state and map the gradual development of the internal stress profile with flexible pressure sensors distributed along the raft surface. Surprisingly, we observe that the surface stress screening builds up much more slowly than previously thought and that the typical screening distance later dramatically decreases. We explain this behavior in terms of progressive friction mobilization, where the full amplitude of the frictional forces is only reached after a macroscopic local displacement. At further stages of compression, rafts of large length-to-width aspect ratio experience much stronger screenings than the full mobilization limit described by the Janssen's model. We solve this paradox using a simple mathematical analysis and show that such enhanced screening can be attributed to a localized compaction front, essentially shielding the far field from compressive stresses.

Annotating Coloured Petri Nets

DEFF Research Database (Denmark)

Lindstrøm, Bo; Wells, Lisa Marie

2002-01-01

Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP......-net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... of the same basic CP-net. One solution to this problem is that the auxiliary information is not integrated into colour sets and arc inscriptions of a CP-net, but is kept separately. This makes it easy to disable this auxiliary information if a CP-net is to be used for another purpose. This paper proposes...

Thermal stress in flexible interdigital transducers with anisotropic electroactive cellulose substrates

Science.gov (United States)

Yoon, Sean J.; Kim, Jung Woong; Kim, Hyun Chan; Kang, Jinmo; Kim, Jaehwan

2017-12-01

Thermal stress in flexible interdigital transducers a reliability concern in the development of flexible devices, which may lead to interface delamination, stress voiding and plastic deformation. In this paper, a mathematical model is presented to investigate the effect of material selections on the thermal stress in interdigital transducers. We modified the linear relationships in the composite materials theory with the effect of high curvature, anisotropic substrate and small substrate thickness. We evaluated the thermal stresses of interdigital transducers, fabricated with various electrodes, insulators and substrate materials for the comparison. The results show that, among various insulators, organic polymer developed the highest stress level while oxide showed the lowest stress level. Aluminium shows a higher stress level and curvature as an electrode than gold. As substrate materials, polyimide and electroactive cellulose show similar stress levels except the opposite sign convention to each other. Polyimide shows positive curvatures while electroactive cellulose shows negative curvatures, which is attributed to the stress and thermal expansion state of the metal/insulator composite. The results show that the insulator is found to be responsible for the confinement across the metal lines while the substrate is responsible for the confinement along the metal lines.

Global confinement characteristics of Jet limiter plasmas

International Nuclear Information System (INIS)

Campbell, D.J.; Christiansen, J.P.; Cordey, J.G.; Thomas, P.R.; Thomsen, K.

1989-01-01

Data from a wide variety of plasma pulses on JET (aux. heating, current, field, minority species, plasma shape, etc) are analysed in order to assess the characteristics of global confinement. The scaling of confinement in ohmically and auxiliary heated discharges is examined. The ohmic confinement in the present new JET configuration (Belt Limiter) is essentially the same as previously. Confinement in auxiliary heated discharges shows presently a slight improvement since 1986. Both ohmic and non-ohmic data is used in a set of confinement time regression analyses and certain constraints derived from theory are imposed

Phase transitions and quark confinement

International Nuclear Information System (INIS)

Polyakov, A.M.; Gava, E.

1978-02-01

The publication collects six lectures on the following themes: quantum field theory and classical statistical mechanics, continuous symmetries, lattice gauge theories, the nature of confinement, a criterion for confinement and non-abelian Yang-Mills theories

Confined Space Evaluation Student Manual, #19613

Energy Technology Data Exchange (ETDEWEB)

Wilmot, David Ezekiel [Los Alamos National Laboratory

2016-08-29

Many workplaces contain spaces that are considered to be “confined” because their configuration hinders the activities of employees who must enter into, work in, and exit from them. In general, the permit-required confined spaces (PRCSs) Occupational Safety and Health Administration (OSHA) standard requires that Los Alamos National Laboratory (LANL) evaluate the workplace to determine if any spaces are PRCSs. The standard specifies strict procedures for the evaluation and atmospheric testing of a space before and during an entry by workers. The OSHA PRCS standard provides for alternative (less stringent than full-permit) entry procedures in cases where the only hazard in a space is atmospheric and the hazard can be controlled by forced air. At LANL, all confined spaces or potential confined spaces on LANL-owned or -operated property must be identified and evaluated by a confined space evaluator accompanied by a knowledgeable person. This course provides the information needed by confined space evaluators to make judgements about whether a space is a confined space, and if so, whether the space will require a permit for entry.

NetSig

DEFF Research Database (Denmark)

Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

2018-01-01

Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

Learning Visual Basic NET

CERN Document Server

Liberty, Jesse

2009-01-01

Learning Visual Basic .NET is a complete introduction to VB.NET and object-oriented programming. By using hundreds of examples, this book demonstrates how to develop various kinds of applications--including those that work with databases--and web services. Learning Visual Basic .NET will help you build a solid foundation in .NET.

Atom-atom scattering under cylindrical harmonic confinement: Numerical and analytic studies of the confinement induced resonance

International Nuclear Information System (INIS)

Bergeman, T.; Moore, M.G.; Olshanii, M.

2003-01-01

It was recently predicted [Phys. Rev. Lett. 81, 938 (1998)10.1103/PhysRevLett.81.938] that atom-atom scattering under transverse harmonic confinement is subject to a 'confinement-induced resonance' where the effective one-dimensional coupling strength diverges at a particular ratio of the confinement and scattering lengths. As the initial prediction made use of the zero-range pseudopotential approximation, we now report numerical results for finite-range interaction potentials that corroborate this resonance. In addition, we now present a physical interpretation of this effect as a novel type of Feshbach resonance in which the transverse modes of the confining potential assume the roles of 'open' and 'closed' scattering channels

Observation of the L-H confinement bifurcation triggered by a turbulence-driven shear flow in a tokamak plasma.

Science.gov (United States)

Yan, Z; McKee, G R; Fonck, R; Gohil, P; Groebner, R J; Osborne, T H

2014-03-28

Comprehensive 2D turbulence and eddy flow velocity measurements on DIII-D demonstrate a rapidly increasing turbulence-driven shear flow that develops ∼100  μs prior to the low-confinement (L mode) to high-confinement (H mode) transition and appears to trigger it. These changes are localized to a narrow layer 1-2 cm inside the magnetic boundary. Increasing heating power increases the Reynolds stress, the energy transfer from turbulence to the poloidal flow, and the edge flow shearing rate that then exceeds the decorrelation rate, suppressing turbulence and triggering the transition.

Confinement effects and mechanistic aspects for montmorillonite nanopores.

Science.gov (United States)

Li, Xiong; Zhu, Chang; Jia, Zengqiang; Yang, Gang

2018-08-01

Owing to the ubiquity, critical importance and special properties, confined microenvironments have recently triggered overwhelming interest. In this work, all-atom molecular dynamics simulations have been conducted to address the confinement effects and ion-specific effects for electrolyte solutions within montmorillonite nanopores, where the pore widths vary with a wide range. The adsorption number, structure, dynamics and stability of inner- and outer-sphere metal ions are affected by the change of pore widths (confinement effects), while the extents are significantly dependent on the type of adsorbed species. The type of adsorbed species is, however, not altered by the magnitude of confinement effects, and confinement effects are similar for different electrolyte concentrations. Ion-specific effects are pronounced for all magnitudes of confinement effects (from non- to strong confined conditions), and Hofmeister sequences of outer-sphere species are closely associated with the magnitude of confinement effects while those of inner-sphere species remain consistent. In addition, mechanistic aspects of confinement have been posed using the electrical double layer theories, and the results can be generalized to other confined systems that are ubiquitous in biology, chemistry, geology and nanotechnology. Copyright © 2018 Elsevier Inc. All rights reserved.

BY FRUSTUM CONFINING VESSEL

Directory of Open Access Journals (Sweden)

Javad Khazaei

2016-09-01

Full Text Available Helical piles are environmentally friendly and economical deep foundations that, due to environmental considerations, are excellent additions to a variety of deep foundation alternatives available to the practitioner. Helical piles performance depends on soil properties, the pile geometry and soil-pile interaction. Helical piles can be a proper alternative in sensitive environmental sites if their bearing capacity is sufficient to support applied loads. The failure capacity of helical piles in this study was measured via an experimental research program that was carried out by Frustum Confining Vessel (FCV. FCV is a frustum chamber by approximately linear increase in vertical and lateral stresses along depth from top to bottom. Due to special geometry and applied bottom pressure, this apparatus is a proper choice to test small model piles which can simulate field stress conditions. Small scale helical piles are made with either single helix or more helixes and installed in fine grained sand with three various densities. Axial loading tests including compression and tension tests were performed to achieve pile ultimate capacity. The results indicate the helical piles behavior depends essentially on pile geometric characteristics, i.e. helix configuration and soil properties. According to the achievements, axial uplift capacity of helical model piles is about equal to usual steel model piles that have the helixes diameter. Helical pile compression bearing capacity is too sufficient to act as a medium pile, thus it can be substituted other piles in special geoenvironmental conditions. The bearing capacity also depends on spacing ratio, S/D, and helixes diameter.

Pattern recognition in probability spaces for visualization and identification of plasma confinement regimes and confinement time scaling

International Nuclear Information System (INIS)

Verdoolaege, G; Karagounis, G; Oost, G Van; Tendler, M

2012-01-01

Pattern recognition is becoming an increasingly important tool for making inferences from the massive amounts of data produced in fusion experiments. The purpose is to contribute to physics studies and plasma control. In this work, we address the visualization of plasma confinement data, the (real-time) identification of confinement regimes and the establishment of a scaling law for the energy confinement time. We take an intrinsically probabilistic approach, modeling data from the International Global H-mode Confinement Database with Gaussian distributions. We show that pattern recognition operations working in the associated probability space are considerably more powerful than their counterparts in a Euclidean data space. This opens up new possibilities for analyzing confinement data and for fusion data processing in general. We hence advocate the essential role played by measurement uncertainty for data interpretation in fusion experiments. (paper)

Ductility of reinforced concrete columns confined with stapled strips

International Nuclear Information System (INIS)

Tahir, M.F.; Khan, Q.U.Z.; Shabbir, F.; Sharif, M.B.; Ijaz, N.

2015-01-01

Response of three 150x150x450mm short reinforced concrete (RC) columns confined with different types of confining steel was investigated. Standard stirrups, strips and stapled strips, each having same cross-sectional area, were employed as confining steel around four comer column bars. Experimental work was aimed at probing into the affect of stapled strip confinement on post elastic behavior and ductility level under cyclic axial load. Ductility ratios, strength enhancement factor and core concrete strengths were compared to study the affect of confinement. Results indicate that strength enhancement in RC columns due to strip and stapled strip confinement was not remarkable as compared to stirrup confined column. It was found that as compared to stirrup confined column, stapled strip confinement enhanced the ductility of RC column by 183% and observed axial capacity of stapled strip confined columns was 41 % higher than the strip confined columns. (author)

Static and kinetic friction of granite at high normal stress

Science.gov (United States)

Byerlee, J.D.

1970-01-01

Frictional sliding on ground surfaces of granite, angle of sliding planes 30?? and 45??, was investigated as a function of confining pressure. Over the normal stress range of 2-12 kb, the static frictional shear stress ??s follows the relationship ??s = 0??5 + 0?? ??n and the kinetic frictional shear stress ??k was calculated to be ??k = 0??25 + 0??47 ??n. ?? 1970.

Pro-Nets versus No-Nets: Differences in Urban Older Adults' Predilections for Internet Use

Science.gov (United States)

Cresci, M. Kay; Yarandi, Hossein N.; Morrell, Roger W.

2010-01-01

Enthusiasm for information technology (IT) is growing among older adults. Many older adults enjoy IT and the Internet (Pro-Nets), but others have no desire to use it (No-Nets). This study found that Pro-Nets and No-Nets were different on a number of variables that might predict IT use. No-Nets were older, had less education and income, were…

Global energy confinement in TORE SUPRA

International Nuclear Information System (INIS)

Hoang, G.T.; Bizarro, J.P.; Genile, B. de; Hutter, Th.; Laurent, L.; Litaudon, X.; Moreau, D.; Peysson, Y.; Tonon, G.; Houtte, D. van

1992-01-01

The global energy confinement behaviour of mixed Ohmic/Lower Hybrid driven Tore Supra plasmas has been analysed at various densities. In contradiction with L-mode ITER scaling law, this analysis indicates that the global energy confinement time depends strongly on the plasma density and the isotopic dependence seems not to be observed. The thermal electron energy content of steady-state discharges is in good agreement with the offset linear Rebut-Lallia scaling law. During current ramp experiments, the global energy confinement time was found to depend on the internal self-inductance (li). Improved confinement has been obtained for a steady-state 0.8 MA plasma where the plasma current profile is peaked by LH waves (li ∼1.8). In this case, the global confinement time is found to be about 40% higher than the value predicted by the Rebut-Lallia scaling law. (author) 3 refs., 6 figs

An introduction to the confinement problem

International Nuclear Information System (INIS)

Greensite, Jeff

2011-01-01

This book addresses the confinement problem, which quite generally deals with the behavior of non-abelian gauge theories, and the force which is mediated by gauge fields, at large distances.The word ''confinement'' in the context of hadronic physics originally referred to the fact that quarks and gluons appear to be trapped inside mesons and baryons, from which they cannot escape. There are other, and possibly deeper meanings that can be attached to the term, and these will be explored in this book. Although the confinement problem is far from solved, much is now known about the general features of the confining force, and there are a number of very well motivated theories of confinement which are under active investigation. This volume gives a both pedagogical and concise introduction and overview of the main ideas in this field, their attractive features, and, as appropriate, their shortcomings. (orig.)

Confinement dynamics in the reversed field pinch

International Nuclear Information System (INIS)

Schoenberg, K.F.

1988-01-01

The study of basic transport and confinement dynamics is central to the development of the reversed field pinch (RFP) as a confinement concept. Thus, the goal of RFP research is to understand the connection between processes that sustain the RFP configuration and related transport/confinement properties. Recently, new insights into confinement have emerged from a detailed investigation of RFP electron and ion physics. These insights derive from the recognition that both magnetohydrodynamic (MHD) and electron kinetic effects play an important and strongly coupled role in RFP sustainment and confinement dynamics. In this paper, we summarize the results of these studies on the ZT-40M experiment. 8 refs

Experiments and simulation of a net closing mechanism for tether-net capture of space debris

Science.gov (United States)

Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

2017-10-01

This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

From Pauli's birthday to 'Confinement Resonances' – a potted history of Quantum Confinement

International Nuclear Information System (INIS)

Connerade, J P

2013-01-01

Quantum Confinement is in some sense a new subject. International meetings dedicated to Quantum Confinement have occurred only recently in Mexico City (the first in 2010 and the second, in September 2011). However, at least in principle, the subject has existed since a very long time. Surprisingly perhaps, it lay dormant for many years, for want of suitable experimental examples. However, when one looks carefully at its origin, it turns out to have a long and distinguished history. In fact, the problem of quantum confinement raises a number of very interesting issues concerning boundary conditions in elementary quantum mechanics and how they should be applied to real problems. Some of these issues were missed in the earliest papers, but are implicit in the structure of quantum mechanics, and lead to the notion of Confinement Resonances, the existence of which was predicted theoretically more than ten years ago. Although, for several reasons, these resonances remained elusive for a very long time, they have now been observed experimentally, which puts the whole subject in much better shape and, together with the advent of metallofullerenes, has contributed to its revival.

Behavior of NiTiNb SMA wires under recovery stress or prestressing.

Science.gov (United States)

Choi, Eunsoo; Nam, Tae-Hyun; Chung, Young-Soo; Kim, Yeon-Wook; Lee, Seung-Yong

2012-01-05

The recovery stress of martensitic shape-memory alloy [SMA] wires can be used to confine concrete, and the confining effectiveness of the SMA wires was previously proved through experimental tests. However, the behavior of SMA wires under recovery stress has not been seriously investigated. Thus, this study conducted a series of tests of NiTiNb martensitic SMA wires under recovery stress with varying degrees of prestrain on the wires and compared the behavior under recovery stress with that under prestressing of the wires. The remaining stress was reduced by the procedure of additional strain loading and unloading. More additional strains reduced more remaining stresses. When the SMA wires were heated up to the transformation temperature under prestress, the stress on the wires increased due to the state transformation. Furthermore, the stress decreased with a decreasing temperature of the wires down to room temperature. The stress of the NiTiNb wires was higher than the prestress, and the developed stress seemed to depend on the composition of the SMAs. When an additional strain was subsequently loaded and unloaded on the prestressed SMA wires, the remaining stress decreased. Finally, the remaining stress becomes zero when loading and unloading a specific large strain.

Momentum confinement at low torque

Energy Technology Data Exchange (ETDEWEB)

Solomon, W M [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Burrell, K H [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); De Grassie, J S [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Budny, R [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Groebner, R J [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Kinsey, J E [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Kramer, G J [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Luce, T C [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Makowski, M A [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Mikkelsen, D [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Nazikian, R [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Petty, C C [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Politzer, P A [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Scott, S D [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Zeeland, M A Van [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Zarnstorff, M C [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States)

2007-12-15

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

Confinement-induced resonances in anharmonic waveguides

Energy Technology Data Exchange (ETDEWEB)

Peng Shiguo [Department of Physics, Tsinghua University, Beijing 100084 (China); Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia); Hu Hui; Liu Xiaji; Drummond, Peter D. [Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia)

2011-10-15

We develop the theory of anharmonic confinement-induced resonances (ACIRs). These are caused by anharmonic excitation of the transverse motion of the center of mass (c.m.) of two bound atoms in a waveguide. As the transverse confinement becomes anisotropic, we find that the c.m. resonant solutions split for a quasi-one-dimensional (1D) system, in agreement with recent experiments. This is not found in harmonic confinement theories. A new resonance appears for repulsive couplings (a{sub 3D}>0) for a quasi-two-dimensional (2D) system, which is also not seen with harmonic confinement. After inclusion of anharmonic energy corrections within perturbation theory, we find that these ACIRs agree extremely well with anomalous 1D and 2D confinement-induced resonance positions observed in recent experiments. Multiple even- and odd-order transverse ACIRs are identified in experimental data, including up to N=4 transverse c.m. quantum numbers.

Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations

International Nuclear Information System (INIS)

McDowell, M.W.; Murray, K.A.

1984-01-01

A conceptual heat transfer loop and balance of plant design for the Pulse*Star Inertial Confinement Fusion Reactor has been investigated and results are presented. The Pulse*Star reaction vessel, a perforated steel bell jar approximately 11 m in diameter, is immersed in Li 17 Pb 83 coolant which flows through the perforations and forms a 1.5 m thick plenum of droplets around an 8 m diameter inner chamber. The reactor and associated pumps, piping, and steam generators are contained within a 17 m diameter pool of Li 17 Pb 83 coolant to minimize structural requirements and occupied space, resulting in reduced cost. Four parallel heat transfer loops with flow rates of 5.5 m 3 /s each are necessary to transfer 3300 MWt of power. The steam generator design was optimized by finding the most cost-effective combination of heat exchanger area and pumping power. Power balance calculations based on an improved electrical conversion efficiency revealed a net electrical output of 1260 MWe to the bus bar and a resulting net efficiency of 39%. Suggested balance-of-plant layouts are also presented

The Physics Basis of ITER Confinement

International Nuclear Information System (INIS)

Wagner, F.

2009-01-01

ITER will be the first fusion reactor and the 50 year old dream of fusion scientists will become reality. The quality of magnetic confinement will decide about the success of ITER, directly in the form of the confinement time and indirectly because it decides about the plasma parameters and the fluxes, which cross the separatrix and have to be handled externally by technical means. This lecture portrays some of the basic principles which govern plasma confinement, uses dimensionless scaling to set the limits for the predictions for ITER, an approach which also shows the limitations of the predictions, and describes briefly the major characteristics and physics behind the H-mode--the preferred confinement regime of ITER.

On the implications of confinement

International Nuclear Information System (INIS)

Roberts, C.D.

1992-01-01

In this paper, the authors consider some implications of confinement starting from the basic observation that cross-sections for the production of colored asymptotic states, such as free quarks and gluons, from color singlet initial states must be zero if QCD is to be confining. The authors discuss two pictures of confinement: the failure of the cluster decomposition property and the absence of a pole at timelike momenta in the propagator of a confined particle. The authors use QCD-based models as a framework to relate the failure of the cluster decomposition property to other ideas, such as the role of a nonzero gluon condensate. The authors' primary interest is to address the question of the absence of a mass pole through a study of model Schwinger-Dyson equations. These equations contain some of the dynamical information that is present in the study of the cluster decomposition property. The authors discuss the problems within this idea and its study using the Schwinger-Dyson equations

Mechanical collapse of confined fluid membrane vesicles.

Science.gov (United States)

Rim, Jee E; Purohit, Prashant K; Klug, William S

2014-11-01

Compact cylindrical and spherical invaginations are common structural motifs found in cellular and developmental biology. To understand the basic physical mechanisms that produce and maintain such structures, we present here a simple model of vesicles in confinement, in which mechanical equilibrium configurations are computed by energy minimization, balancing the effects of curvature elasticity, contact of the membrane with itself and the confining geometry, and adhesion. For cylindrical confinement, the shape equations are solved both analytically and numerically by finite element analysis. For spherical confinement, axisymmetric configurations are obtained numerically. We find that the geometry of invaginations is controlled by a dimensionless ratio of the adhesion strength to the bending energy of an equal area spherical vesicle. Larger adhesion produces more concentrated curvatures, which are mainly localized to the "neck" region where the invagination breaks away from its confining container. Under spherical confinement, axisymmetric invaginations are approximately spherical. For extreme confinement, multiple invaginations may form, bifurcating along multiple equilibrium branches. The results of the model are useful for understanding the physical mechanisms controlling the structure of lipid membranes of cells and their organelles, and developing tissue membranes.

ROOT.NET: Using ROOT from .NET languages like C# and F#

Science.gov (United States)

Watts, G.

2012-12-01

ROOT.NET provides an interface between Microsoft's Common Language Runtime (CLR) and .NET technology and the ubiquitous particle physics analysis tool, ROOT. ROOT.NET automatically generates a series of efficient wrappers around the ROOT API. Unlike pyROOT, these wrappers are statically typed and so are highly efficient as compared to the Python wrappers. The connection to .NET means that one gains access to the full series of languages developed for the CLR including functional languages like F# (based on OCaml). Many features that make ROOT objects work well in the .NET world are added (properties, IEnumerable interface, LINQ compatibility, etc.). Dynamic languages based on the CLR can be used as well, of course (Python, for example). Additionally it is now possible to access ROOT objects that are unknown to the translation tool. This poster will describe the techniques used to effect this translation, along with performance comparisons, and examples. All described source code is posted on the open source site CodePlex.

ROOT.NET: Using ROOT from .NET languages like C and F

International Nuclear Information System (INIS)

Watts, G

2012-01-01

ROOT.NET provides an interface between Microsoft's Common Language Runtime (CLR) and .NET technology and the ubiquitous particle physics analysis tool, ROOT. ROOT.NET automatically generates a series of efficient wrappers around the ROOT API. Unlike pyROOT, these wrappers are statically typed and so are highly efficient as compared to the Python wrappers. The connection to .NET means that one gains access to the full series of languages developed for the CLR including functional languages like F (based on OCaml). Many features that make ROOT objects work well in the .NET world are added (properties, IEnumerable interface, LINQ compatibility, etc.). Dynamic languages based on the CLR can be used as well, of course (Python, for example). Additionally it is now possible to access ROOT objects that are unknown to the translation tool. This poster will describe the techniques used to effect this translation, along with performance comparisons, and examples. All described source code is posted on the open source site CodePlex.

Confinement and the Pomeron

International Nuclear Information System (INIS)

White, A.R.

1989-01-01

The importance of confinement for obtaining a unitary high-energy limit for QCD is discussed. ''Minijets'' are argued to build up non-unitary behavior endash when k T > Λ is imposed. For minijets to mix with low k T Pomeron Field Theory describing confinement, and give consistent asymptotic behavior, new ''quarks'' must enter the theory above the minijet transverse momentum scale. The Critical Pomeron is the resulting high-energy limit. 22 refs

FINITE ELEMENT ANALYSIS OF THE BEHAVIOUR OF REINFORCED CONCRETE COLUMNS CONFINED BY OVERLAPPING HOOPS SUBJECTED TO RAPID CONCENTRIC LOADING

Directory of Open Access Journals (Sweden)

Xiang Zeng

2017-12-01

Full Text Available The strain rate sensitivity of concrete material was discovered approximately one hundred years ago, and it has a marked effect on the behaviour of concrete members subjected to dynamic loadings such as strong earthquake and impact loading. Because of the great importance of the confined reinforced concrete (RC columns in RC structures, the dynamic behaviour of the columns induced by the strain rate effect has been studied, but only few experiments and analyses have been conducted. To investigate the behaviour of overlapping hoop-confined square reinforced normal-strength concrete columns, considering the strain rate effect at a strain rate of 10-5/sec to 10-1/sec induced by earthquake excitation, an explicit dynamic finite element analysis (FEA model was developed in ABAQUS to predict the behaviour of confined RC columns subjected to the rapid concentric loading. A locally modified stress-strain relation of confined concrete with the strain rate sensitivity of the concrete material and the confining effect of overlapping hoops were proposed to complete the simulation of the dynamic behaviour of concrete with the concrete plastic-constitutive model in ABAQUS. The finite element predictions are consistent with the existing test results. Based on the FEA model, a parametric investigation was conducted to capture more information about the behaviour of confined RC columns under varying loading rates.

NET European Network on Neutron Techniques Standardization for Structural Integrity

International Nuclear Information System (INIS)

Youtsos, A.

2004-01-01

Improved performance and safety of European energy production systems is essential for providing safe, clean and inexpensive electricity to the citizens of the enlarged EU. The state of the art in assessing internal stresses, micro-structure and defects in welded nuclear components -as well as their evolution due to complex thermo-mechanical loads and irradiation exposure -needs to be improved before relevant structural integrity assessment code requirements can safely become less conservative. This is valid for both experimental characterization techniques and predictive numerical algorithms. In the course of the last two decades neutron methods have proven to be excellent means for providing valuable information required in structural integrity assessment of advanced engineering applications. However, the European industry is hampered from broadly using neutron research due to lack of harmonised and standardized testing methods. 35 European major industrial and research/academic organizations have joined forces, under JRC coordination, to launch the NET European Network on Neutron Techniques Standardization for Structural Integrity in May 2002. The NET collaborative research initiative aims at further development and harmonisation of neutron scattering methods, in support of structural integrity assessment. This is pursued through a number of testing round robin campaigns on neutron diffraction and small angle neutron scattering - SANS and supported by data provided by other more conventional destructive and non-destructive methods, such as X-ray diffraction and deep and surface hole drilling. NET also strives to develop more reliable and harmonized simulation procedures for the prediction of residual stress and damage in steel welded power plant components. This is pursued through a number of computational round robin campaigns based on advanced FEM techniques, and on reliable data obtained by such novel and harmonized experimental methods. The final goal of

Stresses in equilibrium configurations of inextensible nets with slack

Czech Academy of Sciences Publication Activity Database

Šilhavý, Miroslav

2017-01-01

Roč. 22, č. 4 (2017), s. 649-665 ISSN 1081-2865 Institutional support: RVO:67985840 Keywords : three-dimensional space * stresses in equilibrium configurations Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 2.953, year: 2016 http://journals.sagepub.com/doi/full/10.1177/1081286515599597

Stresses in equilibrium configurations of inextensible nets with slack

Czech Academy of Sciences Publication Activity Database

Šilhavý, Miroslav

2017-01-01

Roč. 22, č. 4 (2017), s. 649-665 ISSN 1081-2865 Institutional support: RVO:67985840 Keywords : three-dimensional space * stresses in equilibrium configurations Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 2.953, year: 2016 http:// journals .sagepub.com/doi/full/10.1177/1081286515599597

INMARSAT-C SafetyNET

Science.gov (United States)

Tsunamis 406 EPIRB's National Weather Service Marine Forecasts INMARSAT-C SafetyNET Marine Forecast Offices greater danger near shore or any shallow waters? NATIONAL WEATHER SERVICE PRODUCTS VIA INMARSAT-C SafetyNET Inmarsat-C SafetyNET is an internationally adopted, automated satellite system for promulgating

Compression Behavior of Confined Columns with High-Volume Fly Ash Concrete

Directory of Open Access Journals (Sweden)

Sung-Won Yoo

2017-01-01

Full Text Available The use of fly ash in ordinary concrete provides practical benefits to concrete structures, such as a gain in long-term strength, reduced hydration heat, improved resistance to chloride, and enhanced workability. However, few studies with high-volume fly ash (HVFA concrete have been conducted that focus on the structural applications such as a column. Thus, there is a need to promote field applications of HVFA concrete as a sustainable construction material. To this end, this study investigated the compressive behavior of reinforced concrete columns that contain HVFA with a 50 percent replacement rate. Six columns were fabricated for this study. The study variables were the HVFA replacement rate, tied steel ratio, and tie steel spacing. The computed ultimate strength by the American Concrete Institute (ACI code conservatively predicted the measured values, and, thus, the existing equation in the ACI code is feasible for confined RC columns that contain HVFA. In addition, an analysis model was calibrated based on the experimental results and is recommended for predicting the stress-strain relationship of confined reinforced concrete columns that contain HVFA.

Confinement of quarks

International Nuclear Information System (INIS)

Nambu, J.

1978-01-01

Three quark models of hadron structure, which suggest an explanation of quarks confinement mechanism in hadrons are considered. Quark classifications, quark flawors and colours, symmetry model of hadron structure based on the colour theory of strong interaction are discussed. Diagrams of colour combinations of quarks and antiquarks, exchange of gluons, binding quarks in hadron. Quark confinement models based on the field theory, string model rotating and bag model are discussed. Diagrams of the colour charge distribution explaining the phenomena of infrared ''slavery'' and ultraviolet ''freedom'' are given. The models considered explain but some quark properties, creating prerequisites for the development of the consequent theory of hadron structure

Quantum net dynamics

International Nuclear Information System (INIS)

Finkelstein, D.

1989-01-01

The quantum net unifies the basic principles of quantum theory and relativity in a quantum spacetime having no ultraviolet infinities, supporting the Dirac equation, and having the usual vacuum as a quantum condensation. A correspondence principle connects nets to Schwinger sources and further unifies the vertical structure of the theory, so that the functions of the many hierarchic levels of quantum field theory (predicate algebra, set theory, topology,hor-ellipsis, quantum dynamics) are served by one in quantum net dynamics

High-level Petri Nets

DEFF Research Database (Denmark)

various journals and collections. As a result, much of this knowledge is not readily available to people who may be interested in using high-level nets. Within the Petri net community this problem has been discussed many times, and as an outcome this book has been compiled. The book contains reprints...... of some of the most important papers on the application and theory of high-level Petri nets. In this way it makes the relevant literature more available. It is our hope that the book will be a useful source of information and that, e.g., it can be used in the organization of Petri net courses. To make......High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...

Increased stocking density influences the acute physiological stress response of common carp (Cyprinus carpio (L.))

NARCIS (Netherlands)

Ruane, N.M.; Carballo, E.C.; Komen, J.

2002-01-01

The physiological response of common carp, Cyprinus carpio (L.) to increased stocking density and an additional acute net confinement stressor was investigated. Stocking densities were increased from 28.4 to 56.8 or 113.6 kg m¿3 by the use of crowding screens and fish were sampled from the crowded

Energy confinement in Ohmic H-mode in TUMAN-3M

International Nuclear Information System (INIS)

Andrejko, M.V.; Askinazi, L.G.; Golant, V.E.; Kornev, V.A.; Lebedev, S.V.; Levin, L.S.; Tukachinsky, A.S.

1997-01-01

The spontaneous transition from Ohmically heated limiter discharges into the regime with improved confinement termed as ''Ohmic H-mode'' has been investigated in ''TUMAN-3''. The typical signatures of H-mode in tokamaks with powerful auxiliary heating have been observed: sharp drop of D α radiation with simultaneous increase in the electron density and stored energy, suppression of the density fluctuations and establishing the steep gradient near the periphery. In 1994 new vacuum vessel had been installed in TUMAN-3 tokamak. The vessel has the same sizes as old one (R 0 =0.55 m, a 1 =0.24 m). New vessel was designed to reduce mechanical stresses in the walls during B T ramp phase of a shot. Therefore modified device - TUMAN-3M is able to produce higher B T and I p , up to 2 T and 0.2 MA respectively. During first experimental run device was operated in Ohmic Regime. In these experiments the possibility to achieve Ohmic H-mode was studied. The study of the parametric dependencies of the energy confinement time in both OH and Ohmic H-mode was performed. In Ohmic H-mode strong dependencies of τ E on plasma current and on input power and weak dependence on density were found. Energy confinement time in TUMAN-3/TUMAN-3M Ohmic H-mode has revealed good agreement with JET/DIII-D/ASDEX scaling for ELM-free H-mode, resulting in very long τ E at the high plasma current discharges. (author)

Combined confinement system applied to tokamaks

International Nuclear Information System (INIS)

Ohkawa, Tihiro

1986-01-01

From particle orbit point of view, a tokamak is a combined confinement configuration where a closed toroidal volume is surrounded by an open confinement system like a magnetic mirror. By eliminating a cold halo plasma, the energy loss from the plasma becomes convective. The H-mode in diverted tokamaks is an example. Because of the favorable scaling of the energy confinement time with temperature, the performance of the tokamak may be significantly improved by taking advantage of this effect. (author)

Planning of nets

International Nuclear Information System (INIS)

Carberry, M

1996-01-01

The paper is about the planning of nets in areas of low density like it is the case of the rural areas. The author includes economic and technological aspects, planning of nets, demands and management among others

Dimensional crossover in fluids under nanometer-scale confinement.

Science.gov (United States)

Das, Amit; Chakrabarti, J

2012-05-01

Several earlier studies have shown signatures of crossover in various static and dynamics properties of a confined fluid when the confining dimension decreases to about a nanometer. The density fluctuations govern the majority of such properties of a fluid. Here, we illustrate the crossover in density fluctuation in a confined fluid, to provide a generic understanding of confinement-induced crossover of fluid properties, using computer simulations. The crossover can be understood as a manifestation of changes in the long-wavelength behavior of fluctuation in density due to geometrical constraints. We further show that the confining potential significantly affects the crossover behavior.

Programming NET Web Services

CERN Document Server

Ferrara, Alex

2007-01-01

Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

Plasma confinement in a magnetic dipole

International Nuclear Information System (INIS)

Kesner, J.; Bromberg, L.; Garnier, D.; Mauel, M.

1999-01-01

A dipole fusion confinement device is stable to MHD interchange and ballooning modes when the pressure profile is sufficiently gentle. The plasma can be confined at high beta, is steady state and disruption free. Theory indicates that when the pressure gradient is sufficiently gentle to satisfy MHD requirements drift waves will also be stable. The dipole approach is particularly applicable for advanced fuels. A new experimental facility is presently being built to test the stability and transport properties of a dipole-confined plasma. (author)

Plasma confinement in a magnetic dipole

International Nuclear Information System (INIS)

Kesner, J.; Bromberg, L.; Garnier, D.; Mauel, M.

2001-01-01

A dipole fusion confinement device is stable to MHD interchange and ballooning modes when the pressure profile is sufficiently gentle. The plasma can be confined at high beta, is steady state and disruption free. Theory indicates that when the pressure gradient is sufficiently gentle to satisfy MHD requirements drift waves will also be stable. The dipole approach is particularly applicable for advanced fuels. A new experimental facility is presently being built to test the stability and transport properties of a dipole-confined plasma. (author)

Bifurcated equilibria in centrifugally confined plasma

International Nuclear Information System (INIS)

Shamim, I.; Teodorescu, C.; Guzdar, P. N.; Hassam, A. B.; Clary, R.; Ellis, R.; Lunsford, R.

2008-01-01

A bifurcation theory and associated computational model are developed to account for abrupt transitions observed recently on the Maryland Centrifugal eXperiment (MCX) [R. F. Ellis et al. Phys. Plasmas 8, 2057 (2001)], a supersonically rotating magnetized plasma that relies on centrifugal forces to prevent thermal expansion of plasma along the magnetic field. The observed transitions are from a well-confined, high-rotation state (HR-mode) to a lower-rotation, lesser-confined state (O-mode). A two-dimensional time-dependent magnetohydrodynamics code is used to simulate the dynamical equilibrium states of the MCX configuration. In addition to the expected viscous drag on the core plasma rotation, a momentum loss term is added that models the friction of plasma on the enhanced level of neutrals expected in the vicinity of the insulators at the throats of the magnetic mirror geometry. At small values of the external rotation drive, the plasma is not well-centrifugally confined and hence experiences the drag from near the insulators. Beyond a critical value of the external drive, the system makes an abrupt transition to a well-centrifugally confined state in which the plasma has pulled away from the end insulator plates; more effective centrifugal confinement lowers the plasma mass near the insulators allowing runaway increases in the rotation speed. The well-confined steady state is reached when the external drive is balanced by only the viscosity of the core plasma. A clear hysteresis phenomenon is shown.

A Study of Confined Helium Atom

International Nuclear Information System (INIS)

Xie Wenfang

2007-01-01

The helium atom confined by a spherical parabolic potential well is studied employing the adiabatic hyperspherical approach method. Total energies of the ground and three low-excited states are obtained as a function of the confined potential radii. We find that the energies of a spherical parabolic potential well are in good agreement with those of an impenetrable spherical box for the larger confined potential radius. We find also that the confinement may cause accidental degeneracies between levels with different low-excited states and the inversion of the energy values. The results for the three-dimensional spherical potential well and the two-dimensional disc-like potential well are compared with each other. We find that the energy difference between states in a two-dimensional parabolic potential is also obviously larger than the corresponding levels for a spherical parabolic potential.

Is the effect of alcohol on risk of stroke confined to highly stressed persons?

DEFF Research Database (Denmark)

Nielsen, N R; Truelsen, T; Barefoot, J C

2005-01-01

BACKGROUND: Psychological stress and alcohol are both suggested as risk factors for stroke. Further, there appears to be a close relation between stress and alcohol consumption. Several experimental studies have found alcohol consumption to reduce the immediate effects of stress in a laboratory...... setting. We aimed to examine whether the association between alcohol and stroke depends on level of self-reported stress in a large prospective cohort. METHODS: The 5,373 men and 6,723 women participating in the second examination of the Copenhagen City Heart Study in 1981-1983 were asked at baseline...... about their self-reported level of stress and their weekly alcohol consumption. The participants were followed-up until 31st of December 1997 during which 880 first ever stroke events occurred. Data were analysed by means of Cox regression modelling. RESULTS: At a high stress level, weekly total...

Ground Motion Prediction Equations Empowered by Stress Drop Measurement

Science.gov (United States)

Miyake, H.; Oth, A.

2015-12-01

Significant variation of stress drop is a crucial issue for ground motion prediction equations and probabilistic seismic hazard assessment, since only a few ground motion prediction equations take into account stress drop. In addition to average and sigma studies of stress drop and ground motion prediction equations (e.g., Cotton et al., 2013; Baltay and Hanks, 2014), we explore 1-to-1 relationship for each earthquake between stress drop and between-event residual of a ground motion prediction equation. We used the stress drop dataset of Oth (2013) for Japanese crustal earthquakes ranging 0.1 to 100 MPa and K-NET/KiK-net ground motion dataset against for several ground motion prediction equations with volcanic front treatment. Between-event residuals for ground accelerations and velocities are generally coincident with stress drop, as investigated by seismic intensity measures of Oth et al. (2015). Moreover, we found faster attenuation of ground acceleration and velocities for large stress drop events for the similar fault distance range and focal depth. It may suggest an alternative parameterization of stress drop to control attenuation distance rate for ground motion prediction equations. We also investigate 1-to-1 relationship and sigma for regional/national-scale stress drop variation and current national-scale ground motion equations.

NET in-vessel vehicle system

International Nuclear Information System (INIS)

Jones, H.

1991-02-01

The CFFTP/Spar In-vessel Vehicle System concept for in-vessel remote maintenance of the NET/ITER machine is described. It comprises a curved deployable boom, a vehicle which can travel on the boom and an end effector or work unit mounted on the vehicle. The stowed boom, vehicle, and work unit are inserted via the equatorial access port of the torus. Following insertion the boom is deployed and locked in place. The vehicle may then travel along the boom to transport the work unit to any desired location. A novel feature of the concept is the deployable boom. When fully deployed, it closely resembles a conventional curved truss structure in configuration and characteristics. However, the joints of the truss structure are hinged so that it can fold into a compact package, of less than 20% of deployed volume for storage, transportation and insertion into the torus. A full-scale 2-metre long section of this boom was produced for demonstration purposes. As part of the concept definition the work unit for divertor handling was studied to demonstrate that large payloads could be manipulated within the confines of the torus using the in-vessel vehicle system. Principal advantages of the IVVS are its high load capacity and rigidity, low weight and stowed volume, simplicity of control and operation, and its relatively high speed of transportation

Topology of polymer chains under nanoscale confinement.

Science.gov (United States)

Satarifard, Vahid; Heidari, Maziar; Mashaghi, Samaneh; Tans, Sander J; Ejtehadi, Mohammad Reza; Mashaghi, Alireza

2017-08-24

Spatial confinement limits the conformational space accessible to biomolecules but the implications for bimolecular topology are not yet known. Folded linear biopolymers can be seen as molecular circuits formed by intramolecular contacts. The pairwise arrangement of intra-chain contacts can be categorized as parallel, series or cross, and has been identified as a topological property. Using molecular dynamics simulations, we determine the contact order distributions and topological circuits of short semi-flexible linear and ring polymer chains with a persistence length of l p under a spherical confinement of radius R c . At low values of l p /R c , the entropy of the linear chain leads to the formation of independent contacts along the chain and accordingly, increases the fraction of series topology with respect to other topologies. However, at high l p /R c , the fraction of cross and parallel topologies are enhanced in the chain topological circuits with cross becoming predominant. At an intermediate confining regime, we identify a critical value of l p /R c , at which all topological states have equal probability. Confinement thus equalizes the probability of more complex cross and parallel topologies to the level of the more simple, non-cooperative series topology. Moreover, our topology analysis reveals distinct behaviours for ring- and linear polymers under weak confinement; however, we find no difference between ring- and linear polymers under strong confinement. Under weak confinement, ring polymers adopt parallel and series topologies with equal likelihood, while linear polymers show a higher tendency for series arrangement. The radial distribution analysis of the topology reveals a non-uniform effect of confinement on the topology of polymer chains, thereby imposing more pronounced effects on the core region than on the confinement surface. Additionally, our results reveal that over a wide range of confining radii, loops arranged in parallel and cross

Fault gouge rheology under confined, high-velocity conditions

Science.gov (United States)

Reches, Z.; Madden, A. S.; Chen, X.

2012-12-01

We recently developed the experimental capability to investigate the shear properties of fine-grain gouge under confined conditions and high-velocity. The experimental system includes a rotary apparatus that can apply large displacements of tens of meters, slip velocity of 0.001- 2.0 m/s, and normal stress of 35 MPa (Reches and Lockner, 2010). The key new component is a Confined ROtary Cell (CROC) that can shear a gouge layer either dry or under pore-pressure. The pore pressure is controlled by two syringe pumps. CROC includes a ring-shape gouge chamber of 62.5 mm inner diameter, 81.25 mm outer diameter, and up to 3 mm thick gouge sample. The lower, rotating part of CROC contains the sample chamber, and the upper, stationary part includes the loading, hollow cylinder and setting for temperature, and dilation measurements, and pore-pressure control. Each side of the gouge chamber has two pairs of industrial, spring-energized, self-lubricating, teflon-graphite seals, built for particle media and can work at temperature up to 250 ded C. The space between each of the two sets of seals is pressurized by nitrogen. This design generates 'zero-differential pressure' on the inner seal (which is in contact with the gouge powder), and prevents gouge leaks. For the preliminary dry experiments, we used ~2.0 mm thick layers of room-dry kaolinite powder. Total displacements were on the order of meters and normal stress up to 4 MPa. The initial shear was accommodated by multiple internal slip surfaces within the kaolinite layer accommodated as oriented Riedel shear structures. Later, the shear was localized within a thin, plate-parallel Y-surface. The kaolinite layer was compacted at a quasi-asymptotic rate, and displayed a steady-state friction coefficient of ~ 0.5 with no clear dependence on slip velocity up to 0.15 m/s. Further experiments with loose quartz sand (grain size ~ 125 micron) included both dry runs and pore-pressure (distilled water) controlled runs. The sand was

Alleviation of mortality induced by salicylate and stress.

Science.gov (United States)

Jastreboff, P J; Brennan, J F

1994-05-15

Protection from the deleterious effects of the interaction of environmental stress and salicylate by calcium supplement was investigated in 96 pigmented rats. Within a 2 x 2 x 4 factorial design, rats were assigned to groups defined by: A) ad lib access to 1) plain tap water, or 2) 50 mM calcium chloride solution; B) exposure to stressors consisting of daily 10 h periods of 1) 98 dB SPL noise, or 2) confinement precluding movements; C) daily injections of 233, 350, or 410 mg/kg of sodium salicylate or the saline vehicle. For subjects maintained on tap water, weight loss and mortality increased with salicylate levels, with all subjects dying in the group drinking water and injected with 410 mg/kg. Calcium protected all of the subjects in the noise stress group but not in the confined group.

Energy confinement scaling from the international stellarator database

Energy Technology Data Exchange (ETDEWEB)

Stroth, U [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Murakami, M; Dory, R A; Yamada, H; Okamura, S; Sano, F; Obiki, T

1995-09-01

An international stellarator database on global energy confinement is presented comprising data from the ATF, CHS and Heliotron E heliotron/torsatrons and the W7-A and W7-AS shearless stellarators. Regression expressions for the energy confinement time are given for the individual devices and the combined dataset. A comparison with tokamak L mode confinement is discussed on the basis of various scaling expressions. In order to make this database available to interested colleagues, the structure of the database and the parameter list are explained in detail. More recent confinement results incorporating data from enhanced confinement regimes such as H mode are reported elsewhere. (author).

Game Coloured Petri Nets

DEFF Research Database (Denmark)

Westergaard, Michael

2006-01-01

This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

Quark confinement in a constituent quark model

International Nuclear Information System (INIS)

Langfeld, K.; Rho, M.

1995-01-01

On the level of an effective quark theory, we define confinement by the absence of quark anti-quark thresholds in correlation function. We then propose a confining Nambu-Jona-Lasinio-type model. The confinement is implemented in analogy to Anderson localization in condensed matter systems. We study the model's phase structure as well as its behavior under extreme conditions, i.e. high temperature and/or high density

Neuro emotional technique effects on brain physiology in cancer patients with traumatic stress symptoms: preliminary findings.

Science.gov (United States)

Monti, Daniel A; Tobia, Anna; Stoner, Marie; Wintering, Nancy; Matthews, Michael; He, Xiao-Song; Doucet, Gaelle; Chervoneva, Inna; Tracy, Joseph I; Newberg, Andrew B

2017-08-01

The purpose of this study was to characterize the neurophysiological and clinical effects that may result from the neuro emotional technique (NET) in patients with traumatic stress symptoms associated with a cancer-related event. We hypothesized that self-regulatory processing of traumatic memories would be observable as physiological changes in key brain areas after undergoing the NET intervention and that these changes would be associated with improvement of traumatic stress symptoms. We enrolled 23 participants with a prior cancer diagnosis who expressed a distressing cancer-related memory that was associated with traumatic stress symptoms of at least 6 months in duration. Participants were randomized to either the NET intervention or a waitlist control condition. To evaluate the primary outcome of neurophysiological effects, all participants received functional magnetic resonance imaging (fMRI) during the auditory presentation of both a neutral stimulus and a description of the specific traumatic event. Pre/post-comparisons were performed between the traumatic and neutral condition, within and between groups. Psychological measures included the Impact of Event Scale (IES), State Trait Anxiety Index (STAI), Brief Symptom Inventory (BSI)-18, and Posttraumatic Cognitions Inventory (PTCI). The initial fMRI scans in both groups showed significant increases in the bilateral parahippocampus and brainstem. After NET, reactivity in the parahippocampus, brainstem, anterior cingulate, and insula was significantly decreased during the traumatic stimulus. Likewise, participants receiving the NET intervention had significant reductions (p stress as measured by the IES and PTCI. This study is an initial step towards understanding mechanistic features of the NET intervention. Specifically, brain regions involved with traumatic memories and distress such as the brainstem, insula, anterior cingulate gyrus, and parahippocampus had significantly reduced activity after the NET

Momentum Confinement at Low Torque

International Nuclear Information System (INIS)

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

2007-01-01

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

Coloured Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt

1991-01-01

This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...

Net zero water

CSIR Research Space (South Africa)

Lindeque, M

2013-01-01

Full Text Available the national grid. The unfortunate situation with water is that there is no replacement technology for water. Water can be supplied from many different sources. A net zero energy development will move closer to a net zero water development by reducing...

Social stress and population cycles: an assessment

International Nuclear Information System (INIS)

Novak, M.A.

1978-01-01

Social stress is a population hypothesis that is invoked to explain the precipitous declines observed in population levels of such rodent species as Microtus pennsylvanicus. According to this hypothesis, stress is produced by the increase in aggressive contacts between animals in a growing population. Continued contacts produce profound hormonal and behavioral changes in these animals which lead to decreases in reproduction and viability. Several theoretical weaknesses of the hypothesis are raised. First, increases in density may not be positively correlated with the number of contacts. Animals may merely build more runways. Second, even if contacts do increase, they may not necessarily be aggressive in nature. Finally, confined populations which reach excessively high densities and for which contacts between animals must increase, fail to show a precipitous decline in numbers. In addition, a major methodological problem is revealed. Although researchers tend to causally connect social stress and precipitous population declines, most studies are correlational in nature. Of those studies that involve actual manipulations of populations, these manipulations are usually performed on confined populations that fail to exhibit the desired phenomonen. The difficulties associated with manipulating unconfined populations are discussed

Infrared slavery and quark confinement

CERN Document Server

Alabiso, C

1976-01-01

The question is considered of whether the so-called infrared slavery mechanism as, e.g., being manifest in non-Abelian gauge theories, necessarily confines quarks. Making a specific ansatz for the long- range forces, the Schwinger-Dyson equation is solved for the quark Green function. Besides having a confining solution, it appears that quarks may by-pass the long-range forces and be produced. (20 refs).

Infrared slavery and quark confinement

International Nuclear Information System (INIS)

Alabiso, C.; Schierholz, G.

1976-01-01

The question of whether the so-called infrared slavery mechanism as, e.g., being manifest in non-Abelian gauge theories, necessarily confines quarks is posed. Making a specific ansatz for the long-range forces, the Schwinger-Dyson equation is solved for the quark Green function. Besides having a confining solution, it appears that quarks may by-pass the long-range forces and be produced. (Auth.)

Towards new information resources for public health--from WordNet to MedicalWordNet.

Science.gov (United States)

Fellbaum, Christiane; Hahn, Udo; Smith, Barry

2006-06-01

In the last two decades, WordNet has evolved as the most comprehensive computational lexicon of general English. In this article, we discuss its potential for supporting the creation of an entirely new kind of information resource for public health, viz. MedicalWordNet. This resource is not to be conceived merely as a lexical extension of the original WordNet to medical terminology; indeed, there is already a considerable degree of overlap between WordNet and the vocabulary of medicine. Instead, we propose a new type of repository, consisting of three large collections of (1) medically relevant word forms, structured along the lines of the existing Princeton WordNet; (2) medically validated propositions, referred to here as medical facts, which will constitute what we shall call MedicalFactNet; and (3) propositions reflecting laypersons' medical beliefs, which will constitute what we shall call the MedicalBeliefNet. We introduce a methodology for setting up the MedicalWordNet. We then turn to the discussion of research challenges that have to be met to build this new type of information resource. We build a database of sentences relevant to the medical domain. The sentences are generated from WordNet via its relations as well as from medical statements broken down into elementary propositions. Two subcorpora of sentences are distinguished, MedicalBeliefNet and MedicalFactNet. The former is rated for assent by laypersons; the latter for correctness by medical experts. The sentence corpora will be valuable for a variety of applications in information retrieval as well as in research in linguistics and psychology with respect to the study of expert and non-expert beliefs and their linguistic expressions. Our work has to meet several considerable challenges. These include accounting for the distinction between medical experts and laypersons, the social issues of expert-layperson communication in different media, the linguistic aspects of encoding medical knowledge, and

Vortex Ring Dynamics in Radially Confined Domains

Science.gov (United States)

Stewart, Kelley; Niebel, Casandra; Jung, Sunghwan; Vlachos, Pavlos

2010-11-01

Vortex ring dynamics have been studied extensively in semi-infinite quiescent volumes. However, very little is known about vortex-ring formation in wall-bounded domains where vortex wall interaction will affect both the vortex ring pinch-off and propagation velocity. This study addresses this limitation and studies vortex formation in radially confined domains to analyze the affect of vortex-ring wall interaction on the formation and propagation of the vortex ring. Vortex rings were produced using a pneumatically driven piston cylinder arrangement and were ejected into a long cylindrical tube which defined the confined downstream domain. A range of confinement domains were studied with varying confinement diameters Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) and were processed using an in-house developed cross-correlation PIV algorithm. The experimental analysis was used to facilitate the development of a theoretical model to predict the variations in vortex ring circulation over time within confined domains.

Multiflavor string-net models

Science.gov (United States)

Lin, Chien-Hung

2017-05-01

We generalize the string-net construction to multiple flavors of strings, each of which is labeled by the elements of an Abelian group Gi. The same flavor of strings can branch, while different flavors of strings can cross one another and thus they form intersecting string nets. We systematically construct the exactly soluble lattice Hamiltonians and the ground-state wave functions for the intersecting string-net condensed phases. We analyze the braiding statistics of the low-energy quasiparticle excitations and find that our model can realize all the topological phases as the string-net model with group G =∏iGi . In this respect, our construction provides various ways of building lattice models which realize topological order G , corresponding to different partitions of G and thus different flavors of string nets. In fact, our construction concretely demonstrates the Künneth formula by constructing various lattice models with the same topological order. As an example, we construct the G =Z2×Z2×Z2 string-net model which realizes a non-Abelian topological phase by properly intersecting three copies of toric codes.

Rare, but challenging tumors: NET

International Nuclear Information System (INIS)

Ivanova, D.; Balev, B.

2013-01-01

Full text: Introduction: Gastroenteropancreatic Neuroendocrine Tumors (GEP - NET) are a heterogeneous group of tumors with different locations and many different clinical, histological, and imaging performance. In a part of them a secretion of various organic substances is present. The morbidity of GEP - NET in the EU is growing, and this leads to increase the attention to them. What you will learn: Imaging methods used for localization and staging of GEP - NET, characteristics of the study’s protocols; Classification of GEP - NET; Demonstration of typical and atypical imaging features of GEP - NET in patients registered at the NET Center at University Hospital ‘St. Marina’, Varna; Features of metastatic NET, The role of imaging in the evaluation of treatment response and follow-up of the patients. Discussion: The image semiotics analysis is based on 19 cases of GEP - NET registered NET Center at University Hospital ‘St. Marina’. The main imaging method is multidetector CT (MDCT), and magnetic resonance imaging (MRI ) has advantages in the evaluation of liver lesions and the local prevalence of anorectal tumors. In patients with advanced disease and liver lesions the assessment of skeletal involvement (MRI/ nuclear medical method) is mandatory. The majority of GEP - NET have not any specific imaging findings. Therefore it is extremely important proper planning and conducting of the study (MDCT and MR enterography; accurate assessment phase of scanning, positive and negative contrast). Conclusion: GEP - NET is a major diagnostic challenge due to the absence of typical imaging characteristics and often an overlap with those of the tumors of different origin can be observed. Therefore, a good knowledge of clinical and imaging changes occurring at different locations is needed. MDCT is the basis for the diagnosis, staging and follow-up of these neoplasms

Correlations In Confined Quantum Plasmas

International Nuclear Information System (INIS)

Dufty, J.W.

2012-01-01

This is the final report for the project 'Correlations in Confined Quantum Plasmas', NSF-DOE Partnership Grant DE FG02 07ER54946, 8/1/2007 - 7/30/2010. The research was performed in collaboration with a group at Christian Albrechts University (CAU), Kiel, Germany. That collaboration, almost 15 years old, was formalized during the past four years under this NSF-DOE Partnership Grant to support graduate students at the two institutions and to facilitate frequent exchange visits. The research was focused on exploring the frontiers of charged particle physics evolving from new experimental access to unusual states associated with confinement. Particular attention was paid to combined effects of quantum mechanics and confinement. A suite of analytical and numerical tools tailored to the specific inquiry has been developed and employed

Cylindrical fabric-confined soil structures

Science.gov (United States)

Harrison, Richard A.

A cylindrical fabric-soil structural concept for implementation on the moon and Mars which provides many advantages is proposed. The most efficient use of fabric is to fashion it into cylindrical tubes, creating cylindrical fabric-confined soil structures. The length, diameter, and curvature of the tubes will depend on the intended application. The cylindrical hoop forces provide radial confinement while end caps provide axial confinement. One of the ends is designed to allow passage of the soil into the fabric tube before sealing. Transportation requirements are reduced due to the low mass and volume of the fabric. Construction requirements are reduced due to the self-erection capability via the pneumatic exoskeleton. Maintenance requirements are reduced due to the passive nature of the concept. The structure's natural ductility is well suited for any seismic activity.

Reinforced confinement in a nuclear reactor

International Nuclear Information System (INIS)

Norman, H.

1988-01-01

The present invention concerns a nuclear reactor containing a reactor core, a swimming pool space that is filled and pressurized with a neutron-absorbing solution, a reactor tank, at least one heat exchanger, at least one inlet line, at least one return line and at least one circulation pump, where the said reactor tank is confined in the said swimming pool space and designed to be cooled with the aid of relatively pure water, which is fed by means of the said at least one circulating pump to the said reactor tank from the said heat exchanger via the said at least one inlet line and is returned to the heat exchanger via the said at least one return line. The problem that is to be solved by the invention is to design a reactor of the above type in such a way that a complete confinement of the primary circuit of the reactor is achieved at relatively low extra cost. This problem is solved by providing the reactor with a special confinement space that confines the heat exchanger, but not the reactor tank, with the confinement space and the swimming pool space being fashioned in the same concrete body

Limitations of shallow nets approximation.

Science.gov (United States)

Lin, Shao-Bo

2017-10-01

In this paper, we aim at analyzing the approximation abilities of shallow networks in reproducing kernel Hilbert spaces (RKHSs). We prove that there is a probability measure such that the achievable lower bound for approximating by shallow nets can be realized for all functions in balls of reproducing kernel Hilbert space with high probability, which is different with the classical minimax approximation error estimates. This result together with the existing approximation results for deep nets shows the limitations for shallow nets and provides a theoretical explanation on why deep nets perform better than shallow nets. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clays in natural and engineered barriers for radioactive waste confinement

International Nuclear Information System (INIS)

2007-01-01

The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO 2 geological sequestration, chemical waste isolation

Clays in natural and engineered barriers for radioactive waste confinement

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO{sub 2} geological sequestration, chemical waste isolation

Exceptional confinement in G(2) gauge theory

International Nuclear Information System (INIS)

Holland, K.; Minkowski, P.; Pepe, M.; Wiese, U.-J.

2003-01-01

We study theories with the exceptional gauge group G(2). The 14 adjoint 'gluons' of a G(2) gauge theory transform as {3}, {3-bar} and {8} under the subgroup SU(3), and hence have the color quantum numbers of ordinary quarks, anti-quarks and gluons in QCD. Since G(2) has a trivial center, a 'quark' in the {7} representation of G(2) can be screened by 'gluons'. As a result, in G(2) Yang-Mills theory the string between a pair of static 'quarks' can break. In G(2) QCD there is a hybrid consisting of one 'quark' and three 'gluons'. In supersymmetric G(2) Yang-Mills theory with a {14} Majorana 'gluino' the chiral symmetry is Z(4) χ . Chiral symmetry breaking gives rise to distinct confined phases separated by confined-confined domain walls. A scalar Higgs field in the {7} representation breaks G(2) to SU(3) and allows us to interpolate between theories with exceptional and ordinary confinement. We also present strong coupling lattice calculations that reveal basic features of G(2) confinement. Just as in QCD, where dynamical quarks break the Z(3) symmetry explicitly, G(2) gauge theories confine even without a center. However, there is not necessarily a deconfinement phase transition at finite temperature

Energy Confinement of both Ohmic and LHW Plasma on EAST

International Nuclear Information System (INIS)

Yang Yao; Gao Xiang

2011-01-01

Study on the characters of energy confinement in both Ohmic and lower hybrid wave (LHW) discharges on EAST is conducted and the linear Ohmic confinement (LOC), saturated ohmic confinement (SOC) and improved Ohmic confinement (IOC) regimes are investigated in this paper. It is observed that an improved confinement mode characterized by both a drop of D α line intensity and an increase in line average density can be triggered by a gas puffing pulse. (magnetically confined plasma)

Energy confinement in Doublet III with high-Z limiters

Energy Technology Data Exchange (ETDEWEB)

Marcus, F.B.; Adcock, S.J.; Baker, D.R.; Blau, F.P.; Brooks, N.H.; Chase, R.P.; DeBoo, J.C.; Ejima, S.; Fairbanks, E.S.; Fisher, R.K.

1980-02-01

This report describes the experimental measurements and data analysis techniques used to evaluate the energy confinement in noncircular plasmas produced in Doublet III. Major aspects of the confinement measurements and analysis techniques are summarized. Machine parameters, diagnostic systems and discharge parameters relavent to the confinement measurements are given. Magnetic analysis techniques used to determine the plasma shape are reviewed. Scaling of the on-axis values of electron temperature, confinement time and Z/sub eff/ with plasma density is presented. Comparison with scaling results from other circular tokamaks is discussed. Numerical and analytic techniques developed for calculating the plasma energy confinement time and self-consistent profiles of density, temperature, current, and flux in non-circular geometries are described. These techniques are applied to the data and used to determine the central and global electron energy confinement time for a typical doublet plasma. Additional aspects of the confinement such as the radial dependence of the electron thermal conductivity and the estimated ion temperature are explored with the aid of a non-circular transport simulation code. The results of the confinement measurements are summarized and discussed. A brief summary of the theoretically expected effects of noncircularity on plasma confinement is included for reference as Appendix I.

Monopole current dynamics and color confinement

International Nuclear Information System (INIS)

Ichie, H.; Suganuma, H.; Tanaka, A.

1998-01-01

Color confinement can be understood by the dual Higgs theory, where monopole condensation leads to the exclusion of the electric flux from the QCD vacuum. We study the role of the monopole for color confinement by investigating the monopole current system. When the self-energy of the monopole current is small enough, long and complicated monopole world-lines appear, which is a signal of monopole condensation. In the dense monopole system, the Wilson loop obeys the area-law, and the string tension and the monopole density have similar behavior as the function of the self-energy, which seems that monopole condensation leads to color confinement. On the long-distance physics, the monopole current system almost reproduces essential features of confinement properties in lattice QCD. In the short-distance physics, however, the monopole-current theory would become nonlocal and complicated due to the monopole size effect. This monopole size would provide a critical scale of QCD in terms of the dual Higgs mechanism. (orig.)

Extended BRS algebra and color confinement

International Nuclear Information System (INIS)

Shintani, Meiun.

1984-02-01

We examine the color confinement scheme and its realizations proposed by Kugo and Ojima. Using the Nakanishi's theorem, we obtain a representation of the extended BRS algebra compatible with the so-called K-O condition of their confinement criteria. However, it turns out that the representation is not physically acceptable, and thus their scheme lacks self-consistency at the level of realizations. We also clarify what kind of ghost structures are suggested by the well-definedness or ill-definedness of the charge operator Nsup(a) constituting a part of the global color charge operator. It is shown that there are four possible cancellation mechanisms of ghosts. In particular, it turns out that the octet of ghosts suggested by Nishijima in his confinement theory arises from the well-definedness of the Nsup(a) charge, whereas the elementary quartet arises from the ill-definedness of the Nsup(a). Moreover, from the octet structures, we deduce the confinement condition which replaces the K-O condition. (author)

The effect of netting solidity ratio and inclined angle on the hydrodynamic characteristics of knotless polyethylene netting

Science.gov (United States)

Tang, Hao; Hu, Fuxiang; Xu, Liuxiong; Dong, Shuchuang; Zhou, Cheng; Wang, Xuefang

2017-10-01

Knotless polyethylene (PE) netting has been widely used in aquaculture cages and fishing gears, especially in Japan. In this study, the hydrodynamic coefficient of six knotless PE netting panels with different solidity ratios were assessed in a flume tank under various attack angles of netting from 0° (parallel to flow) to 90° (perpendicular to flow) and current speeds from 40 cm s-1 to 130 cm s-1. It was found that the drag coefficient was related to Reynolds number, solidity ratio and attack angle of netting. The solidity ratio was positively related with drag coefficient for netting panel perpendicular to flow, whereas when setting the netting panel parallel to the flow the opposite result was obtained. For netting panels placed at an angle to the flow, the lift coefficient reached the maximum at an attack angle of 50° and then decreased as the attack angle further increased. The solidity ratio had a dual influence on drag coefficient of inclined netting panels. Compared to result in the literature, the normal drag coefficient of knotless PE netting measured in this study is larger than that of nylon netting or Dyneema netting.

Physics of inertial confinement pellets

International Nuclear Information System (INIS)

Mead, W.C.

1979-01-01

An overview of inertial confinement fusion pellet physics is given. A discussion is presented of current estimated ICF driver requirements and a couple of pellet examples. The physics of driver/plasma coupling for two drivers which are being considered, namely a laser driver and a heavy ion accelerator driver, is described. Progress towards inertial confinement fusion that has been made using laser drivers in target experiments to date is discussed

Use of bed nets and factors that influence bed net use among Jinuo Ethnic Minority in southern China.

Science.gov (United States)

Xu, Jian-wei; Liao, Yuan-mei; Liu, Hui; Nie, Ren-hua; Havumaki, Joshua

2014-01-01

Insecticide-treated nets (ITNs) are an integral part of vector control recommendations for malaria elimination in China. This study investigated the extent to which bed nets were used and which factors influence bed net use among Jinuo Ethnic Minority in China-Myanmar-Laos border areas. This study combined a quantitative household questionnaire survey and qualitative semi-structured in-depth interviews (SDI). Questionnaires were administered to 352 heads of households. SDIs were given to 20 key informants. The bed net to person ratio was 1∶2.1 (i.e., nearly one net for every two people), however only 169 (48.0%) households owned at least one net and 623 (47.2%) residents slept under bed nets the prior night. The percentages of residents who regularly slept under nets (RSUN) and slept under nets the prior night (SUNPN) were similar (48.0% vs. 47.2%, P>0.05), however the percentage correct use of nets (CUN) was significantly lower (34.5%, Pcash income per person (ACIP) was an independent factor that influenced bed net use (PHigh bed net availability does not necessarily mean higher coverage or bed net use. Household income, house type and knowledge of the ability of bed nets to prevent malaria are all independent factors that influence bed net use among Jinuo Ethnic Minority.

Fusion through the NET

International Nuclear Information System (INIS)

Spears, B.

1987-01-01

The paper concerns the next generation of fusion machines which are intended to demonstrate the technical viability of fusion. In Europe, the device that will follow on from JET is known as NET - the Next European Torus. If the design programme for NET proceeds, Europe could start to build the machine in 1994. The present JET programme hopes to achieve breakeven in the early 1990's. NET hopes to reach ignition in the next century, and so lay the foundation for a demonstration reactor. A description is given of the technical specifications of the components of NET, including: the first wall, the divertors to protect the wall, the array of magnets that provide the fields containing the plasma, the superconducting magnets, and the shield of the machine. NET's research programme is briefly outlined, including the testing programme to optimise conditions in the machine to achieve ignition, and its safety work. (U.K.)

NetView technical research

Science.gov (United States)

1993-01-01

This is the Final Technical Report for the NetView Technical Research task. This report is prepared in accordance with Contract Data Requirements List (CDRL) item A002. NetView assistance was provided and details are presented under the following headings: NetView Management Systems (NMS) project tasks; WBAFB IBM 3090; WPAFB AMDAHL; WPAFB IBM 3084; Hill AFB; McClellan AFB AMDAHL; McClellan AFB IBM 3090; and Warner-Robins AFB.

Heritability of cortisol response to confinement stress in European sea bass dicentrarchus labrax

NARCIS (Netherlands)

Volckaert, F.A.M.; Hellemans, B.; Batargias, C.; Louro, B.; Massault, C.; Houdt, Van J.K.J.; Haley, C.; Koning, de D.J.; Canario, A.V.M.

2012-01-01

Background: In fish, the most studied production traits in terms of heritability are body weight or growth, stress or disease resistance, while heritability of cortisol levels, widely used as a measure of response to stress, is less studied. In this study, we have estimated heritabilities of two

Efficacy of PermaNet® 3.0 and PermaNet® 2.0 nets against laboratory-reared and wild Anopheles gambiae sensu lato populations in northern Tanzania.

Science.gov (United States)

Kweka, Eliningaya J; Lyaruu, Lucile J; Mahande, Aneth M

2017-01-18

Mosquitoes have developed resistance against pyrethroids, the only class of insecticides approved for use on long-lasting insecticidal nets (LLINs). The present study sought to evaluate the efficacy of the pyrethroid synergist PermaNet® 3.0 LLIN versus the pyrethroid-only PermaNet® 2.0 LLIN, in an East African hut design in Lower Moshi, northern Tanzania. In this setting, resistance to pyrethroid insecticides has been identified in Anopheles gambiae mosquitoes. Standard World Health Organization bioefficacy evaluations were conducted in both laboratory and experimental huts. Experimental hut evaluations were conducted in an area where there was presence of a population of highly pyrethroid-resistant An. arabiensis mosquitoes. All nets used were subjected to cone bioassays and then to experimental hut trials. Mosquito mortality, blood-feeding inhibition and personal protection rate were compared between untreated nets, unwashed LLINs and LLINs that were washed 20 times. Both washed and unwashed PermaNet® 2.0 and PermaNet® 3.0 LLINs had knockdown and mortality rates of 100% against a susceptible strain of An. gambiae sensu stricto. The adjusted mortality rate of the wild mosquito population after use of the unwashed PermaNet® 3.0 and PermaNet® 2.0 nets was found to be higher than after use of the washed PermaNet® 2.0 and PermaNet® 3.0 nets. Given the increasing incidence of pyrethroid resistance in An. gambiae mosquitoes in Tanzania, we recommend that consideration is given to its distribution in areas with pyrethroid-resistant malaria vectors within the framework of a national insecticide-resistance management plan.

PODATKOVNE STORITVE ADO.NET IN ADO.NET ENTITY FRAMEWORK

OpenAIRE

Volavc, Franc

2012-01-01

V diplomskem delu smo predstavili Microsoftovi ogrodji ADO.NET in ADO.NET Entity Framework. Preučili in analizirali smo metode za dostop do podatkovnih virov, ki jih ponujata ogrodji, ter nato te ugotovitve preslikati v odločitveno drevo, katero bo programerjem in razvijalcem informacijskih sistemov pomagalo pri odločanju glede pristopa za dostop do podatkovnih virov. Ker bomo v diplomskem delu predstavili Microsoftovi ogrodji, bomo posledično omejeni zgolj na Microsoftovo tehnologijo, se pra...

Combined Transverse Steel-External FRP Confinement Model for Rectangular Reinforced Concrete Columns

Directory of Open Access Journals (Sweden)

Ahmed Al-Rahmani

2016-02-01

Full Text Available Recently, the need to increase the strength of reinforced concrete members has become a subject that civil engineers are interested in tackling. Of the many proposed solutions, fiber-reinforced polymer (FRP materials have attracted attention due to their superior properties, such as high strength-to-weight ratio, high energy absorption and excellent corrosion resistance. FRP wrapping of concrete columns is done to enhance the ultimate strength due to the confinement effect, which is normally induced by steel ties. The existence of the two confinement systems changes the nature of the problem, thus necessitating specialized nonlinear analysis to obtain the column’s ultimate capacity. Existing research focused on a single confinement system. Furthermore, very limited research on rectangular sections was found in the literature. In this work, a model to estimate the combined behavior of the two systems in rectangular columns is proposed. The calculation of the effective lateral pressure is based on the Lam and Teng model and the Mander model for FRP wraps and steel ties, respectively. The model then generates stress-strain diagrams for both the concrete core and the cover. The model was developed for the analysis in extreme load events, where all possible contributions to the column’s ultimate capacity should be accounted for without any margin of safety. The model was validated against experiments, and the results obtained showed good agreement with almost all of the available experimental data.

Climate conditions in bedded confinement buildings

Science.gov (United States)

Confinement buildings are utilized for finishing cattle to allow more efficient collection of animal waste and to buffer animals against adverse climatic conditions. Environmental data were obtained from a 29 m wide x 318 m long bedded confinement building with the long axis oriented east to west. T...

Blanket testing in NET

International Nuclear Information System (INIS)

Chazalon, M.; Daenner, W.; Libin, B.

1989-01-01

The testing stages in NET for the performance assessment of the various breeding blanket concepts developed at the present time in Europe for DEMO (LiPb and ceramic blankets) and the requirements upon NET to perform these tests are reviewed. Typical locations available in NET for blanket testing are the central outboard segments and the horizontal ports of in-vessel sectors. These test positions will be connectable with external test loops. The number of test loops (helium, water, liquid metal) will be such that each major class of blankets can be tested in NET. The test positions, the boundary conditions and the external test loops are identified and the requirements for test blankets are summarized (author). 6

Environmental blue light prevents stress in the fish Nile tilapia

Directory of Open Access Journals (Sweden)

Volpato G.L.

2001-01-01

Full Text Available The present study aimed to test the effects of blue, green or white light on the stress response of the Nile tilapia, Oreochromis niloticus (L.. Each color was tested on two groups of isolated adult Nile tilapia (8 replicates each: one being subjected to confinement stress, and the other not (control. A different environmental color was imposed on each compartment by covering the light source with cellophane of the respective color (green or blue; no cellophane was used for white light. The intensity of green, white and blue lights was 250, 590 and 250 lux, respectively. Basal plasma cortisol levels were determined for each fish prior to the experimental procedures. The fish were confined by being displaced toward one side of the aquarium using an opaque partition for 1 h both in the morning and the afternoon of the two consecutive days of the test. At the end of this 48-h period, plasma cortisol levels were measured again. Basal cortisol levels (ng/ml were similar for each group (ANOVA, F(2;42 = 0.77, P = 0.47. Thus, plasma cortisol levels were analyzed in terms of variation from their respective basal level. After confinement, plasma cortisol levels were not increased in fish submitted to a blue light environment. Thus, blue light prevents the confinement-induced cortisol response, an effect not necessarily related to light intensity.

Quark propagators and correlators in a confining vacuum

International Nuclear Information System (INIS)

Simonov, Yu.A.

1987-01-01

Quark propagators, quark-antiquark Green functions and photon selfenergy operator Π (2) (k) are considered in the background (anti)selfdual field. The cases of a homogeneous selfdual field in d=4 and magnetic field in d=2 are studied in detail. Isolated quarks and quark-antiquark pairs are shown to be confined in those cases with the quadratic form of confining potential. In the space filled with domains of the homogeneous field with random directions the confining potential is of linear form, and the colorless qq-bar pair is not confined

Plasma confinement system and methods for use

Science.gov (United States)

Jarboe, Thomas R.; Sutherland, Derek

2017-09-05

A plasma confinement system is provided that includes a confinement chamber that includes one or more enclosures of respective helicity injectors. The one or more enclosures are coupled to ports at an outer radius of the confinement chamber. The system further includes one or more conductive coils aligned substantially parallel to the one or more enclosures and a further set of one or more conductive coils respectively surrounding portions of the one or more enclosures. Currents may be provided to the sets of conductive coils to energize a gas within the confinement chamber into a plasma. Further, a heat-exchange system is provided that includes an inner wall, an intermediate wall, an outer wall, and pipe sections configured to carry coolant through cavities formed by the walls.

A compliant mechanism for inspecting extremely confined spaces

Science.gov (United States)

Mascareñas, David; Moreu, Fernando; Cantu, Precious; Shields, Daniel; Wadden, Jack; El Hadedy, Mohamed; Farrar, Charles

2017-11-01

We present a novel, compliant mechanism that provides the capability to navigate extremely confined spaces for the purpose of infrastructure inspection. Extremely confined spaces are commonly encountered during infrastructure inspection. Examples of such spaces can include pipes, conduits, and ventilation ducts. Often these infrastructure features go uninspected simply because there is no viable way to access their interior. In addition, it is not uncommon for extremely confined spaces to possess a maze-like architecture that must be selectively navigated in order to properly perform an inspection. Efforts by the imaging sensor community have resulted in the development of imaging sensors on the millimeter length scale. Due to their compact size, they are able to inspect many extremely confined spaces of interest, however, the means to deliver these sensors to the proper location to obtain the desired images are lacking. To address this problem, we draw inspiration from the field of endoscopic surgery. Specifically we consider the work that has already been done to create long flexible needles that are capable of being steered through the human body. These devices are typically referred to as ‘steerable needles.’ Steerable needle technology is not directly applicable to the problem of navigating maze-like arrangements of extremely confined spaces, but it does provide guidance on how this problem should be approached. Specifically, the super-elastic nitinol tubing material that allows steerable needles to operate is also appropriate for the problem of navigating maze-like arrangements of extremely confined spaces. Furthermore, the portion of the mechanism that enters the extremely confined space is completely mechanical in nature. The mechanical nature of the device is an advantage when the extremely confined space features environmental hazards such as radiation that could degrade an electromechanically operated mechanism. Here, we present a compliant mechanism

A Cascade Disaster Caused by Geological and Coupled Hydro-Mechanical Factors—Water Inrush Mechanism from Karst Collapse Column under Confining Pressure

Directory of Open Access Journals (Sweden)

Hao Li

2017-11-01

Full Text Available The water inrush from karst collapse column (KCC is a cascading, vicious cycle disaster caused by geological and mining activities, that can cause serious casualties and property losses. The key to preventing this risk is to study the mechanism of water inrush under confining pressure. Aiming at the investigationg the characteristics of the KCC named X1 in Chensilou mine, a series of methods, including connectivity experiments, water pressure monitoring tests in two side-walls, and numerical simulations based on plastic damage-seepage (PD-S theory have been developed. The methods are used to test the security of the 2519 mining area, the damage thickness, pore water pressure, and seepage vector in the X1. The results indicate that the X1 has a certain water blocking capacity. In addition, with the decrease of confining pressure and increase of shear stress, deviatoric stress could cause the increase of permeability, the reduction of strength, and the reduction of pore water pressure in KCC. Therefore the increased effective stress in the rock will force the rock to become more fractured. Conversely, the broken rock could cause the change of stress, and further initiate new plastic strains, damage and pore water pressure until a new equilibrium is reached. This cascading water inrush mechanism will contribute to the exploitation of deep coal resources in complex geological and hydrogeological conditions.

Density and Phase State of a Confined Nonpolar Fluid

Science.gov (United States)

Kienle, Daniel F.; Kuhl, Tonya L.

2016-07-01

Measurements of the mean refractive index of a spherelike nonpolar fluid, octamethytetracylclosiloxane (OMCTS), confined between mica sheets, demonstrate direct and conclusive experimental evidence of the absence of a first-order liquid-to-solid phase transition in the fluid when confined, which has been suggested to occur from previous experimental and simulation results. The results also show that the density remains constant throughout confinement, and that the fluid is incompressible. This, along with the observation of very large increases (many orders of magnitude) in viscosity during confinement from the literature, demonstrate that the molecular motion is limited by the confining wall and not the molecular packing. In addition, the recently developed refractive index profile correction method, which enables the structural perturbation inherent at a solid-liquid interface and that of a liquid in confinement to be determined independently, was used to show that there was no measurable excess or depleted mass of OMCTS near the mica surface in bulk films or confined films of only two molecular layers.

Cardiovascular outcomes after pharmacologic stress myocardial perfusion imaging.

Science.gov (United States)

Lee, Douglas S; Husain, Mansoor; Wang, Xuesong; Austin, Peter C; Iwanochko, Robert M

2016-04-01

While pharmacologic stress single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) is used for noninvasive evaluation of patients who are unable to perform treadmill exercise, its impact on net reclassification improvement (NRI) of prognosis is unknown. We evaluated the prognostic value of pharmacologic stress MPI for prediction of cardiovascular death or non-fatal myocardial infarction (MI) within 1 year at a single-center, university-based laboratory. We examined continuous and categorical NRI of pharmacologic SPECT-MPI for prediction of outcomes beyond clinical factors alone. Six thousand two hundred forty patients (median age 66 years [IQR 56-74], 3466 men) were studied and followed for 5963 person-years. SPECT-MPI variables associated with increased risk of cardiovascular death or non-fatal MI included summed stress score, stress ST-shift, and post-stress resting left ventricular ejection fraction ≤50%. Compared to a clinical model which included age, sex, cardiovascular disease, risk factors, and medications, model χ(2) (210.5 vs. 281.9, P statistic (0.74 vs. 0.78, P stress score, stress ST-shift and stress resting left ventricular ejection fraction). SPECT-MPI predictors increased continuous NRI by 49.4% (P 3% annualized risk of cardiovascular death or non-fatal MI, yielded a 15.0% improvement in NRI (95% CI 7.6%-27.6%, P stress MPI substantially improved net reclassification of cardiovascular death or MI risk beyond that afforded by clinical factors. Copyright © 2016 Elsevier Inc. All rights reserved.

The structure of nematic model of liquid crystal with cylindrical and ellipsoidal molecules confined in between walls

Directory of Open Access Journals (Sweden)

M. Moradi

2004-12-01

Full Text Available   The density functional theory analogue of Percus Yevick (PY and Hyper-Netted chain (HNC has been used to write the grand potential of a liquid with cylindrical and ellipsoidal molecules. The integral equations for the density can be obtained by minimizing the grand potential with respect to the density. Some kinds of liquid crystals, can have the cylindrical or ellipsoidal rigid molecules. In this study we have calculated the density profile of this kind of liquids confined between hard walls and we compared the results. As it is seen from the graphs of the density profiles the molecules can be arranged as layers with respect to the walls.

LOW-MASS PLANETS IN PROTOPLANETARY DISKS WITH NET VERTICAL MAGNETIC FIELDS: THE PLANETARY WAKE AND GAP OPENING

Energy Technology Data Exchange (ETDEWEB)

Zhu Zhaohuan; Stone, James M.; Rafikov, Roman R., E-mail: zhzhu@astro.princeton.edu, E-mail: jstone@astro.princeton.edu, E-mail: rrr@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ, 08544 (United States)

2013-05-10

Some regions in protoplanetary disks are turbulent, while some regions are quiescent (e.g. the dead zone). In order to study how planets open gaps in both inviscid hydrodynamic disk (e.g. the dead zone) and the disk subject to magnetorotational instability (MRI), we carried out both shearing box two-dimensional inviscid hydrodynamical simulations and three-dimensional unstratified magnetohydrodynamical (MHD) simulations (having net vertical magnetic fields) with a planet at the box center. We found that, due to the nonlinear wave steepening, even a low mass planet can open gaps in both cases, in contradiction to the ''thermal criterion'' for gap opening. In order to understand if we can represent the MRI turbulent stress with the viscous {alpha} prescription for studying gap opening, we compare gap properties in MRI-turbulent disks to those in viscous HD disks having the same stress, and found that the same mass planet opens a significantly deeper and wider gap in net vertical flux MHD disks than in viscous HD disks. This difference arises due to the efficient magnetic field transport into the gap region in MRI disks, leading to a larger effective {alpha} within the gap. Thus, across the gap, the Maxwell stress profile is smoother than the gap density profile, and a deeper gap is needed for the Maxwell stress gradient to balance the planetary torque density. Comparison with previous results from net toroidal flux/zero flux MHD simulations indicates that the magnetic field geometry plays an important role in the gap opening process. We also found that long-lived density features (termed zonal flows) produced by the MRI can affect planet migration. Overall, our results suggest that gaps can be commonly produced by low mass planets in realistic protoplanetary disks, and caution the use of a constant {alpha}-viscosity to model gaps in protoplanetary disks.

LOW-MASS PLANETS IN PROTOPLANETARY DISKS WITH NET VERTICAL MAGNETIC FIELDS: THE PLANETARY WAKE AND GAP OPENING

International Nuclear Information System (INIS)

Zhu Zhaohuan; Stone, James M.; Rafikov, Roman R.

2013-01-01

Some regions in protoplanetary disks are turbulent, while some regions are quiescent (e.g. the dead zone). In order to study how planets open gaps in both inviscid hydrodynamic disk (e.g. the dead zone) and the disk subject to magnetorotational instability (MRI), we carried out both shearing box two-dimensional inviscid hydrodynamical simulations and three-dimensional unstratified magnetohydrodynamical (MHD) simulations (having net vertical magnetic fields) with a planet at the box center. We found that, due to the nonlinear wave steepening, even a low mass planet can open gaps in both cases, in contradiction to the ''thermal criterion'' for gap opening. In order to understand if we can represent the MRI turbulent stress with the viscous α prescription for studying gap opening, we compare gap properties in MRI-turbulent disks to those in viscous HD disks having the same stress, and found that the same mass planet opens a significantly deeper and wider gap in net vertical flux MHD disks than in viscous HD disks. This difference arises due to the efficient magnetic field transport into the gap region in MRI disks, leading to a larger effective α within the gap. Thus, across the gap, the Maxwell stress profile is smoother than the gap density profile, and a deeper gap is needed for the Maxwell stress gradient to balance the planetary torque density. Comparison with previous results from net toroidal flux/zero flux MHD simulations indicates that the magnetic field geometry plays an important role in the gap opening process. We also found that long-lived density features (termed zonal flows) produced by the MRI can affect planet migration. Overall, our results suggest that gaps can be commonly produced by low mass planets in realistic protoplanetary disks, and caution the use of a constant α-viscosity to model gaps in protoplanetary disks.

3D characterization of coal strains induced by compression, carbon dioxide sorption, and desorption at in-situ stress conditions

International Nuclear Information System (INIS)

Pone, J. Denis N.; Halleck, Phillip M.; Mathews, Jonathan P.

2010-01-01

Sequestration of carbon dioxide in unmineable coal seams is an option to combat climate change and an opportunity to enhance coalbed methane production. Prediction of sequestration potential in coal requires characterization of porosity, permeability, sorption capacity and the magnitude of swelling due to carbon dioxide uptake or shrinkage due to methane and water loss. Unfortunately, the majority of data characterizing coal-gas systems have been obtained from powdered, unconfined coal samples. Little is known about confined coal behavior during carbon dioxide uptake and methane desorption. The present work focuses on the characterization of lithotype specific deformation, and strain behavior during CO 2 uptake at simulated in-situ stress conditions. It includes the evaluation of three-dimensional strain induced by the confining stress, the sorption, and the desorption of carbon dioxide. X-ray computed tomography allowed three-dimensional characterization of the bituminous coal deformation samples under hydrostatic stress. The application of 6.9 MPa of confining stress contributes an average of - 0.34% volumetric strain. Normal strains due to confining stress were - 0.08%, - 0.15% and - 0.11% along the x, y and z axes respectively. Gas injection pressure was 3.1 MPa and the excess sorption was 0.85 mmol/g. Confined coal exposed to CO 2 for 26 days displays an average volumetric expansion of 0.4%. Normal strains due to CO 2 sorption were 0.11%, 0.22% and 0.11% along x, y and z axes. Drainage of the CO 2 induced an average of - 0.33% volumetric shrinkage. Normal strains due to CO 2 desorption were - 0.23%, - 0.08% and - 0.02% along x, y and z axes. Alternating positive and negative strain values observed along the sample length during compression, sorption and desorption respectively emphasized that both localized compression/compaction and expansion of coal will occur during CO 2 sequestration. (author)

Diffusion of Finite-Size Particles in Confined Geometries

KAUST Repository

Bruna, Maria; Chapman, S. Jonathan

2013-01-01

The diffusion of finite-size hard-core interacting particles in two- or three-dimensional confined domains is considered in the limit that the confinement dimensions become comparable to the particle's dimensions. The result is a nonlinear diffusion equation for the one-particle probability density function, with an overall collective diffusion that depends on both the excluded-volume and the narrow confinement. By including both these effects, the equation is able to interpolate between severe confinement (for example, single-file diffusion) and unconfined diffusion. Numerical solutions of both the effective nonlinear diffusion equation and the stochastic particle system are presented and compared. As an application, the case of diffusion under a ratchet potential is considered, and the change in transport properties due to excluded-volume and confinement effects is examined. © 2013 Society for Mathematical Biology.

Current Status and Future Prospect of K-NET and KiK-net

Science.gov (United States)

Aoi, S.; Kunugi, T.; Suzuki, W.; Nakamura, H.; Fujiwara, H.

2014-12-01

During 18 years since the deployment of K-NET following the Kobe earthquake, our attention has mainly focused on rapidity of the data collection and an unfailing and reliable observation. In this presentation, we review three generations of the instruments employed by K-NET and KiK-net from these two points of view.At beginning of the 2000's, we newly developed the second generation instruments (K-NET02, K-NET02A, KiK-net06) to replace the first generation instruments (K-NET95, SMAC-MDK) employed when the networks were constructed in the 1990's. These instruments have an automatic dial-out function. It takes typically 2-5 s to establish communication and a few seconds to send the pre-trigger data. After that, data is available typically within a 1.5 s delay. Not only waveform data but also strong motion indexes such as real-time intensity, PGA, PGV, PGD, and response spectra are continuously sent once a second.After the 2011 Tohoku earthquake, we have developed the third generation instruments (K-NET11, KiK-net11) and have replaced almost half of the all stations country wide. Main improvement of this instrument is more unfailing and reliable observation. Because we have often experienced very large ground motions (e.g. 45 records exceeding gravity), the maximum measureable range was expanded from 2000 gal to 4000 gal for the second generation instrument, and to 8000 gal for the third. For the third generation instrument, in case of power failure, observation (including transmission of data) works for seven days thanks to the backup battery, while for the second generation instruments it works only for one day. By adding an oblique component to the three-component accelerometers, we could automatically distinguish shaking data from noise such as electric pulses which may cause a false alarm in EEW. Implementation to guarantee the continuity of observation under severe conditions such as during the Tohoku earthquake is very important, as well as a highly efficient

Simulations of water nano-confined between corrugated planes

Science.gov (United States)

Zubeltzu, Jon; Artacho, Emilio

2017-11-01

Water confined to nanoscale widths in two dimensions between ideal planar walls has been the subject of ample study, aiming at understanding the intrinsic response of water to confinement, avoiding the consideration of the chemistry of actual confining materials. In this work, we study the response of such nanoconfined water to the imposition of a periodicity in the confinement by means of computer simulations, both using empirical potentials and from first-principles. For that we propose a periodic confining potential emulating the atomistic oscillation of the confining walls, which allows varying the lattice parameter and amplitude of the oscillation. We do it for a triangular lattice, with several values of the lattice parameter: one which is ideal for commensuration with layers of Ih ice and other values that would correspond to more realistic substrates. For the former, the phase diagram shows an overall rise of the melting temperature. The liquid maintains a bi-layer triangular structure, however, despite the fact that it is not favoured by the external periodicity. The first-principles liquid is significantly affected by the modulation in its layering and stacking even at relatively small amplitudes of the confinement modulation. Beyond some critical modulation amplitude, the hexatic phase present in flat confinement is replaced by a trilayer crystalline phase unlike any of the phases encountered for flat confinement. For more realistic lattice parameters, the liquid does not display higher tendency to freeze, but it clearly shows inhomogeneous behaviour as the strength of the rugosity increases. In spite of this expected inhomogeneity, the structural and dynamical response of the liquid is surprisingly insensitive to the external modulation. Although the first-principles calculations give a more triangular liquid than the one observed with empirical potentials (TIP4P/2005), both agree remarkably well for the main conclusions of the study.

Impurity confinement and transport in high confinement regimes without edge localized modes on DIII-D

Energy Technology Data Exchange (ETDEWEB)

Grierson, B. A., E-mail: bgriers@pppl.gov; Nazikian, R. M.; Solomon, W. M. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Garofalo, A. M.; Belli, E. A.; Staebler, G. M.; Evans, T. E.; Smith, S. P.; Chrobak, C. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Fenstermacher, M. E. [Lawerence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); McKee, G. R. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53796 (United States); Orlov, D. M. [Center for Energy Research, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Chrystal, C. [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States)

2015-05-15

Impurity transport in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] is investigated in stationary high confinement (H-mode) regimes without edge localized modes (ELMs). In plasmas maintained by resonant magnetic perturbation (RMP), ELM-suppression, and QH-mode, the confinement time of fluorine (Z = 9) is equivalent to that in ELMing discharges with 40 Hz ELMs. For selected discharges with impurity injection, the impurity particle confinement time compared to the energy confinement time is in the range of τ{sub p}/τ{sub e}≈2−3. In QH-mode operation, the impurity confinement time is shown to be smaller for intense, coherent magnetic, and density fluctuations of the edge harmonic oscillation than weaker fluctuations. Transport coefficients are derived from the time evolution of the impurity density profile and compared to neoclassical and turbulent transport models NEO and TGLF. Neoclassical transport of fluorine is found to be small compared to the experimental values. In the ELMing and RMP ELM-suppressed plasma, the impurity transport is affected by the presence of tearing modes. For radii larger than the mode radius, the TGLF diffusion coefficient is smaller than the experimental value by a factor of 2–3, while the convective velocity is within error estimates. Low levels of diffusion are observed for radii smaller than the tearing mode radius. In the QH-mode plasma investigated, the TGLF diffusion coefficient is higher inside of ρ=0.4 and lower outside of 0.4 than the experiment, and the TGLF convective velocity is more negative by a factor of approximately 1.7.

Markets, voucher subsidies and free nets combine to achieve high bed net coverage in rural Tanzania

Directory of Open Access Journals (Sweden)

Gerrets Rene PM

2008-06-01

Full Text Available Abstract Background Tanzania has a well-developed network of commercial ITN retailers. In 2004, the government introduced a voucher subsidy for pregnant women and, in mid 2005, helped distribute free nets to under-fives in small number of districts, including Rufiji on the southern coast, during a child health campaign. Contributions of these multiple insecticide-treated net delivery strategies existing at the same time and place to coverage in a poor rural community were assessed. Methods Cross-sectional household survey in 6,331 members of randomly selected 1,752 households of 31 rural villages of Demographic Surveillance System in Rufiji district, Southern Tanzania was conducted in 2006. A questionnaire was administered to every consenting respondent about net use, treatment status and delivery mechanism. Findings Net use was 62.7% overall, 87.2% amongst infants (0 to1 year, 81.8% amongst young children (>1 to 5 years, 54.5% amongst older children (6 to 15 years and 59.6% amongst adults (>15 years. 30.2% of all nets had been treated six months prior to interview. The biggest source of nets used by infants was purchase from the private sector with a voucher subsidy (41.8%. Half of nets used by young children (50.0% and over a third of those used by older children (37.2% were obtained free of charge through the vaccination campaign. The largest source of nets amongst the population overall was commercial purchase (45.1% use and was the primary means for protecting adults (60.2% use. All delivery mechanisms, especially sale of nets at full market price, under-served the poorest but no difference in equity was observed between voucher-subsidized and freely distributed nets. Conclusion All three delivery strategies enabled a poor rural community to achieve net coverage high enough to yield both personal and community level protection for the entire population. Each of them reached their relevant target group and free nets only temporarily

Effects of ACTH, capture, and short term confinement on glucocorticoid concentrations in harlequin ducks (Histrionicus histrionicus)

Science.gov (United States)

Nilsson, P.B.; Hollmén, Tuula E.; Atkinson, S.; Mashburn, K.L.; Tuomi, P.A.; Esler, Daniel N.; Mulcahy, D.M.; Rizzolo, D.J.

2008-01-01

Little is known about baseline concentrations of adrenal hormones and hormonal responses to stress in sea ducks, although significant population declines documented in several species suggest that sea ducks are exposed to increased levels of environmental stress. Such declines have been observed in geographically distinct harlequin duck populations. We performed an adrenocorticotropic hormone (ACTH) challenge to evaluate adrenal function and characterize corticosterone concentrations in captive harlequin ducks and investigated the effects of capture, surgery, and short term confinement on corticosterone concentrations in wild harlequin ducks. Harlequin ducks responded to the ACTH challenge with an average three-fold increase in serum corticosterone concentration approximately 90 min post injection, and a four- to five-fold increase in fecal glucocorticoid concentration 2 to 4 h post injection. Serum corticosterone concentrations in wild harlequin ducks increased within min of capture and elevated levels were found for several hours post capture, indicating that surgery and confinement maintain elevated corticosterone concentrations in this species. Mean corticosterone concentrations in wild harlequin ducks held in temporary captivity were similar to the maximum response levels during the ACTH challenge in captive birds. However, large variation among individuals was observed in responses of wild birds, and we found additional evidence suggesting that corticosterone responses varied between hatch year and after hatch year birds.

Initial CAD investigations for NET

International Nuclear Information System (INIS)

Katz, F.; Leinemann, K.; Ludwig, A.; Marek, U.; Olbrich, W.; Schlechtendahl, E.G.

1985-11-01

This report summarizes the work done under contract no. 164/84-7/FU-D-/NET between the Commission of the European Communities and KfK during the period from June 1, 1984, through May 31, 1985. The following topics are covered in this report: Initial modelling of NET version NET2A, CAD system extension for remote handling studies, analysis of the CAD information structure, work related to the transfer of CAD information between KfK and the NET team. (orig.) [de

Random walks and polygons in tight confinement

International Nuclear Information System (INIS)

Diao, Y; Ernst, C; Ziegler, U

2014-01-01

We discuss the effect of confinement on the topology and geometry of tightly confined random walks and polygons. Here the walks and polygons are confined in a sphere of radius R ≥ 1/2 and the polygons are equilateral with n edges of unit length. We illustrate numerically that for a fixed length of random polygons the knotting probability increases to one as the radius decreases to 1/2. We also demonstrate that for random polygons (walks) the curvature increases to πn (π(n – 1)) as the radius approaches 1/2 and that the torsion decreases to ≈ πn/3 (≈ π(n – 1)/3). In addition we show the effect of length and confinement on the average crossing number of a random polygon

The cruel and unusual phenomenology of solitary confinement.

Science.gov (United States)

Gallagher, Shaun

2014-01-01

What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a "cruel and unusual punishment," there is no consensus on the definition of the term "cruel" in the use of that legal phrase. I argue that we can find a moral consensus on the meaning of "cruelty" by looking specifically at the phenomenology and psychology of solitary confinement.

NetBeans IDE 8 cookbook

CERN Document Server

Salter, David

2014-01-01

If you're a Java developer of any level using NetBeans and want to learn how to get the most out of NetBeans, then this book is for you. Learning how to utilize NetBeans will provide a firm foundation for your Java application development.

The Net Advance of Physics

Science.gov (United States)

THE NET ADVANCE OF PHYSICS Review Articles and Tutorials in an Encyclopædic Format Established 1995 [Link to MIT] Computer support for The Net Advance of Physics is furnished by The Massachusetts Newest Additions SPECIAL FEATURES: Net Advance RETRO: Nineteenth Century Physics History of Science

Higher representations: Confinement and large N

International Nuclear Information System (INIS)

Sannino, Francesco

2005-01-01

We investigate the confining phase transition as a function of temperature for theories with dynamical fermions in the two index symmetric and antisymmetric representation of the gauge group. By studying the properties of the center of the gauge group we predict for an even number of colors a confining phase transition, if second order, to be in the universality class of Ising in three dimensions. This is due to the fact that the center group symmetry does not break completely for an even number of colors. For an odd number of colors the center group symmetry breaks completely. This pattern remains unaltered at a large number of colors. The confining/deconfining phase transition in these theories at large and finite N is not mapped in the one of super Yang-Mills theory. We extend the Polyakov loop effective theory to describe the confining phase transition of the theories studied here for a generic number of colors. Our results are not modified when adding matter in the same higher dimensional representations of the gauge group. We comment on the interplay between confinement and chiral symmetry in these theories and suggest that they are ideal laboratories to shed light on this issue also for ordinary QCD. We compare the free energy as a function of temperature for different theories. We find that the conjectured thermal inequality between the infrared and ultraviolet degrees of freedom computed using the free energy does not lead to new constraints on asymptotically free theories with fermions in higher dimensional representations of the gauge group. Since the center of the gauge group is an important quantity for the confinement properties at zero temperature our results are relevant here as well

Improved netting

International Nuclear Information System (INIS)

Bramley, A.; Clabburn, R.J.T.

1976-01-01

A method is described for producing netting composed of longitudinal and transverse threads of irradiation cross linked thermoplastic material, the threads being joined together at their crossings by moulded masses of cross linked thermoplastic material. The thread may be formed of polyethylene filaments, subjected to a radiation dose of 15 to 25 MR. The moulding can be conducted at 245 0 to 260 0 C or higher. The product is claimed to be an improved quality of netting, with bonds of increased strength between crossing threads. (U.K.)

Magnetic well for plasma confinement

International Nuclear Information System (INIS)

Valfells, A.; Chiu, Y.C.

1977-01-01

A multipole magnetic well for plasma confinement includes a plurality of current-carrying coils placed on planes corresponding to the facets of a regular polyhedron that can be symmetrically circumscribed about a sphere. The direction of current in the coils is such as to minimize the flux density at the center of the polyhedron, thereby providing a confinement well with three-dimensional symmetry having an increasing flux density in all directions from the center. 16 claims, 18 figures

Neutron spectroscopy for confinement studies

International Nuclear Information System (INIS)

Zorn, R.

2010-01-01

Neutron spectroscopy is an important method for the study of microscopic dynamics because it captures the spatial as well as the temporal aspects of the atomic or molecular motion. In this article techniques will be presented which are of special importance for the study of confined systems. Many of these are based on the fact that neutron scattering is isotope-dependent. Possible sources of systematic errors in measurements of confined systems will be pointed out. (author)

Diffusion of Finite-Size Particles in Confined Geometries

KAUST Repository

Bruna, Maria

2013-05-10

The diffusion of finite-size hard-core interacting particles in two- or three-dimensional confined domains is considered in the limit that the confinement dimensions become comparable to the particle\\'s dimensions. The result is a nonlinear diffusion equation for the one-particle probability density function, with an overall collective diffusion that depends on both the excluded-volume and the narrow confinement. By including both these effects, the equation is able to interpolate between severe confinement (for example, single-file diffusion) and unconfined diffusion. Numerical solutions of both the effective nonlinear diffusion equation and the stochastic particle system are presented and compared. As an application, the case of diffusion under a ratchet potential is considered, and the change in transport properties due to excluded-volume and confinement effects is examined. © 2013 Society for Mathematical Biology.

Perspectives on confinement in helical systems

International Nuclear Information System (INIS)

Itoh, Kimitaka; Itoh, Sanae

1989-01-01

A review on recent experimental results and theoretical models on anomalous transport and density limit in toroidal helical devices is presented. Importance of transport problems is discussed. Experiments on Heliotron-E, Wendelstein-VIIA and new devices, i.e., ATF, Wendelstein-VIIAS and CHS, are reviewed and an overview on confinement property is given. From recent experimental results one sees that there are anomalous transport, which increases with temperature, and density limit, and that they limit the energy confinement time as well as the attainable beta value. The confinement characteristics of the scrape off layer plasma and loss cone loss are discussed, and perspectives on the high temperature plasma are given. These anomalous transport and density limit will be difficult obstacles in realizing a reactor grade plasma in helical systems. It is an urgent task to draw a realistic picture of the confinement based on the present data base. The relevant knowledge now would be critically essential for the successful development of the research in 1990's. (author) 102 refs

Comments on experimental results of energy confinement of tokamak plasmas

International Nuclear Information System (INIS)

Chu, T.K.

1989-04-01

The results of energy-confinement experiments on steady-state tokamak plasmas are examined. For plasmas with auxiliary heating, an analysis based on the heat diffusion equation is used to define heat confinement time (the incremental energy confinement time). For ohmically sustained plasmas, experiments show that the onset of the saturation regime of energy confinement, marfeing, detachment, and disruption are marked by distinct values of the parameter /bar n//sub e///bar j/. The confinement results of the two types of experiments can be described by a single surface in 3-dimensional space spanned by the plasma energy, the heating power, and the plasma density: the incremental energy confinement time /tau//sub inc/ = ΔW/ΔP is the correct concept for describing results of heat confinement in a heating experiment; the commonly used energy confinement time defined by /tau//sub E/ = W/P is not. A further examination shows that the change of edge parameters, as characterized by the change of the effective collision frequency ν/sub e/*, governs the change of confinement properties. The totality of the results of tokamak experiments on energy confinement appears to support a hypothesis that energy transport is determined by the preservation of the pressure gradient scale length. 70 refs., 6 figs., 1 tab

Net alkalinity and net acidity 1: Theoretical considerations

International Nuclear Information System (INIS)

Kirby, Carl S.; Cravotta, Charles A.

2005-01-01

Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO 2 , and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined 'CO 2 -acidity' is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO 2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass-action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mgL -1 as CaCO 3 (based on pH and analytical concentrations of dissolved Fe II , Fe III , Mn, and Al in mgL -1 ):acidity calculated =50{1000(10 -pH )+[2(Fe II )+3(Fe III )]/56+2(Mn) /55+3(Al)/27}underestimates contributions from HSO 4 - and H + , but overestimates the acidity due to Fe 3+ and Al 3+ . However, these errors tend to approximately cancel each other. It is demonstrated that 'net alkalinity' is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the

Net alkalinity and net acidity 1: Theoretical considerations

Science.gov (United States)

Kirby, C.S.; Cravotta, C.A.

2005-01-01

Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

Proof Nets for Lambek Calculus

NARCIS (Netherlands)

Roorda, Dirk

1992-01-01

The proof nets of linear logic are adapted to the non-commutative Lambek calculus. A different criterion for soundness of proof nets is given, which gives rise to new algorithms for proof search. The order sensitiveness of the Lambek calculus is reflected by the planarity condition on proof nets;

Confinement and quark structure of light hadrons

International Nuclear Information System (INIS)

Efimov, G.V.; Ivanov, M.A.

1988-01-01

We present a quark confinement model (QCM) for the description of the low-energy physics of light hadrons (mesons and baryons). The model is based on two hypotheses. First, the quark confinement is realized as averaging over vacuum gluon fields which are believed to provide the confinement of any colour objects. Second, hadrons are treated as collective colourless excitations of quark-gluon interactions. The description of strong, electromagnetic and weak interactions of mesons and baryons at the low energy is given from a unique point of view

Properties of porous netted materials

International Nuclear Information System (INIS)

Daragan, V.D.; Drozdov, B.G.; Kotov, A.Yu.; Mel'nikov, G.N.; Pustogarov, A.V.

1987-01-01

Hydraulic and strength characteristics, efficient heat conduction and inner heat exchange coefficient are experimentally studied for porous netted materials on the base of the brass nets as dependent on porosity, cell size and method of net laying. Results of the studies are presented. It is shown that due to anisotropy of the material properties the hydraulic resistance in the direction parallel to the nets plane is 1.3-1.6 times higher than in the perpendicular one. Values of the effective heat conduction in the direction perpendicular to the nets plane at Π>0.45 agree with the data from literature, at Π<0.45 a deviation from the calculated values is marked in the direction of the heat conduction decrease

High temperature L- and H-mode confinement in JET

International Nuclear Information System (INIS)

Balet, B.; Boyd, D.A.; Campbell, D.J.

1990-01-01

The energy confinement properties of low density, high ion temperature L- and H-mode plasmas are investigated. For L-mode plasmas it is shown that, although the global confinement is independent of density, the energy confinement in the central region is significantly better at low densities than at higher densities. The improved confinement appears to be associated with the steepness of the density gradient. For the H-mode phase, although the confinement at the edge is dramatically improved, which is once again associated with the steep density gradient in the edge region, the central confinement properties are essentially the same as for the standard L-mode. The results are compared in a qualitative manner with the predictions of the ion temperature gradient instability theory and appear to be in disagreement with some aspects of this theory. (author). 13 refs, 15 figs

Drought stress had a predominant effect over heat stress on three tomato cultivars subjected to combined

DEFF Research Database (Denmark)

Zhou, Rong; Yu, Xiaqing; Ottosen, Carl-Otto

2017-01-01

and relative water content of all cultivars significantly decreased under drought and combined stress as compared to control. The net photosynthesis and starch content were significantly lower under drought and combined stress than control in the three cultivars. Stomata and pore length of the three cultivars......BACKGROUND: Abiotic stresses due to environmental factors could adversely affect the growth and development of crops. Among the abiotic stresses, drought and heat stress are two critical threats to crop growth and sustainable agriculture worldwide. Considering global climate change, incidence...... of combined drought and heat stress is likely to increase. The aim of this study was to shed light on plant growth performance and leaf physiology of three tomatoes cultivars ('Arvento', 'LA1994' and 'LA2093') under control, drought, heat and combined stress. RESULTS: Shoot fresh and dry weight, leaf area...

Net-section limit moments and approximate J estimates for circumferential cracks at the interface between elbows and pipes

International Nuclear Information System (INIS)

Song, Tae-Kwang; Kim, Yun-Jae; Oh, Chang-Kyun; Jin, Tae-Eun; Kim, Jong-Sung

2009-01-01

This paper firstly presents net-section limit moments for circumferential through-wall and part-through surface cracks at the interface between elbows and attached straight pipes under in-plane bending. Closed-form solutions are proposed based on fitting results from small strain FE limit analyses using elastic-perfectly plastic materials. Net-section limit moments for circumferential cracks at the interface between elbows and attached straight pipes are found to be close to those for cracks in the centre of elbows, implying that the location of the circumferential crack within an elbow has a minimal effect on the net-section limit moment. Accordingly it is also found that the assumption that the crack locates in a straight pipe could significantly overestimate the net-section limit load (and thus maximum load-carrying capacity) of the cracked component. Based on the proposed net-section limit moment, a method to estimate elastic-plastic J based on the reference stress approach is proposed for circumferential cracks at the interface between elbows and attached straight pipes under in-plane bending.

Solitons and confinement

International Nuclear Information System (INIS)

Swieca, J.A.

1976-01-01

Some aspects of two recent developments in quantum field theory are discussed. First, related with 'extended particles' such as soliton, kink and the 't Hooft monopole. Second, with confinement of particles which are realized in the Schwinger model [pt

Ion distribution in the hot spot of an inertial confinement fusion plasma

Science.gov (United States)

Tang, Xianzhu; Guo, Zehua; Berk, Herb

2012-10-01

Maximizing the fusion gain of inertial confinement fusion (ICF) for inertial fusion energy (IFE) applications leads to the standard scenario of central hot spot ignition followed by propagating burn wave through the cold/dense assembled fuel. The fact that the hot spot is surrounded by cold but dense fuel layer introduces subtle plasma physics which requires a kinetic description. Here we perform Fokker-Planck calculations and kinetic PIC simulations for an ICF plasma initially in pressure balance but having large temperature gradient over a narrow transition layer. The loss of the fast ion tail from the hot spot, which is important for fusion reactivity, is quantified by Fokker-Planck models. The role of electron energy transport and the ambipolar electric field is investigated via kinetic simulations and the fluid moment models. The net effect on both hot spot ion temperature and the ion tail distribution, and hence the fusion reactivity, is elucidated.

Evaluation of the confinement option for LMRs

International Nuclear Information System (INIS)

Himes, D.A.; Stepnewski, D.D.; Franz, G.R.

1985-12-01

The coolant in liquid metal cooled reactors operates at low pressures and therefore contains relatively little stored energy compared to LWR systems. This presents the possibility of using a more conventional building for containment coupled with a confinement system which vents the internal volume of the building through a filter/scrubber. The confinement system would be designed to keep the internal pressure in the containment near atmospheric thereby minimizing unfiltered leakage. The principal benefits of such an arrangement would be lower capital cost and less stringent leaktightness requirements permitting simpler and less disruptive testing. In conclusion, the confinement system assumed here would reduce consequences to the public of an LMR HCDA to acceptable levels. However control room doses are unacceptable due to the noble gas concentration inside the control room. A confinement system is therefore a viable design option for LMR's provided means are included for keeping noble gases out of the control room. Such means are readily available including, for example, selectable remote air intakes, an exhaust stack, or a noble gas filter. Probably the most satisfactory alternative would be a large cryogenic filter on the confinement system exhaust

Generating equilateral random polygons in confinement II

International Nuclear Information System (INIS)

Diao, Y; Ernst, C; Montemayor, A; Ziegler, U

2012-01-01

In this paper we continue an earlier study (Diao et al 2011 J. Phys. A: Math. Theor. 44 405202) on the generation algorithms of random equilateral polygons confined in a sphere. Here, the equilateral random polygons are rooted at the center of the confining sphere and the confining sphere behaves like an absorbing boundary. One way to generate such a random polygon is the accept/reject method in which an unconditioned equilateral random polygon rooted at origin is generated. The polygon is accepted if it is within the confining sphere, otherwise it is rejected and the process is repeated. The algorithm proposed in this paper offers an alternative to the accept/reject method, yielding a faster generation process when the confining sphere is small. In order to use this algorithm effectively, a large, reusable data set needs to be pre-computed only once. We derive the theoretical distribution of the given random polygon model and demonstrate, with strong numerical evidence, that our implementation of the algorithm follows this distribution. A run time analysis and a numerical error estimate are given at the end of the paper. (paper)

Packing frustration in dense confined fluids.

Science.gov (United States)

Nygård, Kim; Sarman, Sten; Kjellander, Roland

2014-09-07

Packing frustration for confined fluids, i.e., the incompatibility between the preferred packing of the fluid particles and the packing constraints imposed by the confining surfaces, is studied for a dense hard-sphere fluid confined between planar hard surfaces at short separations. The detailed mechanism for the frustration is investigated via an analysis of the anisotropic pair distributions of the confined fluid, as obtained from integral equation theory for inhomogeneous fluids at pair correlation level within the anisotropic Percus-Yevick approximation. By examining the mean forces that arise from interparticle collisions around the periphery of each particle in the slit, we calculate the principal components of the mean force for the density profile--each component being the sum of collisional forces on a particle's hemisphere facing either surface. The variations of these components with the slit width give rise to rather intricate changes in the layer structure between the surfaces, but, as shown in this paper, the basis of these variations can be easily understood qualitatively and often also semi-quantitatively. It is found that the ordering of the fluid is in essence governed locally by the packing constraints at each single solid-fluid interface. A simple superposition of forces due to the presence of each surface gives surprisingly good estimates of the density profiles, but there remain nontrivial confinement effects that cannot be explained by superposition, most notably the magnitude of the excess adsorption of particles in the slit relative to bulk.

Understanding Net Zero Energy Buildings

DEFF Research Database (Denmark)

Salom, Jaume; Widén, Joakim; Candanedo, José

2011-01-01

Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid...

History-dependent stochastic Petri nets

NARCIS (Netherlands)

Schonenberg, H.; Sidorova, N.; Aalst, van der W.M.P.; Hee, van K.M.; Pnueli, A.; Virbitskaite, I.; Voronkov, A.

2010-01-01

Stochastic Petri Nets are a useful and well-known tool for performance analysis. However, an implicit assumption in the different types of Stochastic Petri Nets is the Markov property. It is assumed that a choice in the Petri net only depends on the current state and not on earlier choices. For many

Plasma confinement in the TMX tandem mirror

International Nuclear Information System (INIS)

Hooper, E.B. Jr.; Allen, S.L.; Casper, T.A.

1981-01-01

Plasma confinement in the Tandem Mirror Experiment (TMX) is described. Axially confining potentials are shown to exist throughout the central 20-cm core of TMX. Axial electron-confinement time is up to 100 times that of single-cell mirror machines. Radial transport of ions is smaller than axial transport near the axis. It has two parts at large radii: nonambipolar, in rough agreement with predictions from resonant-neoclassical transport theory, and ambipolar, observed near the plasma edge under certain conditions, accompanied by a low-frequency, m = 1 instability or strong turbulence

The cruel and unusual phenomenology of solitary confinement

Directory of Open Access Journals (Sweden)

Shaun eGallagher

2014-06-01

Full Text Available What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a cruel and unusual punishment, there is no consensus on the definition of the term ‘cruel’ in the use of that legal phrase. I argue that we can find a moral consensus on the meaning of ‘cruelty’ by looking specifically at the phenomenology and psychology of solitary confinement.

Pro ASP.NET 4 in VB 2010

CERN Document Server

MacDonald, Matthew; Freeman, Adam; Szpuszta, Mario; Agarwal, Vidya Vrat

2010-01-01

ASP.NET 4 is the latest version of Microsoft's revolutionary ASP.NET technology. It is the principal standard for creating dynamic web pages on the Windows platform. Pro ASP.NET 4 in VB 2010 raises the bar for high-quality, practical advice on learning and deploying Microsoft's dynamic web solution. This new edition is updated with everything you need to come to grips with the latest version of ASP.NET, including coverage of ASP.NET MVC, ASP.NET AJAX 4, ASP.NET Dynamic Data, and Silverlight 3. Seasoned .NET professionals Matthew MacDonald and Mario Szpuszta explain how you can get the most fro

Fluctuations and confinement in ATF

International Nuclear Information System (INIS)

Isler, R.C.; Harris, J.H.; Murakami, M.

1993-01-01

In the period immediately prior to the suspension of ATF operation in November, 1991, a great deal of emphasis was palced on investigations of the fundamental mechanisms controlling confinement in this device. At that time, measurements of the density fluctuations throughout the plasma volume indicated the existence of theoretically predicted dissipative trapped electron and resistive interchange instabilities. These identifications were supported by results of dynamic configuration scans of the magnetic fields during which the extent of the magnetic well, shear, and fraction of confined trapped particles were changed continuously. Interpretation of the data from these experiments has been an ongoing exercise. Most recently, analysis of discharges employing strong gas puffing to change density gradients and fluctuation levels have strengthened the view that dissipative trapped electron modes may be present but do not play a significant direct role in energy transport. The present paper summarizes the current understanding concerning the identification of instabilities and their relationship to confinement in ATF

Confinement and strings in MQCD

International Nuclear Information System (INIS)

Hanany, A.; Strassler, M.J.; Zaffaroni, A.

1998-01-01

We study aspects of confinement in the M-theory fivebrane version of QCD (MQCD). We show heavy quarks are confined in hadrons (which take the form of membrane-fivebrane bound states) for N=1 and softly broken N=2 SU(N) MQCD. We explore and clarify the transition from the exotic physics of the latter to the standard physics of the former. In particular, the many strings and quark-antiquark mesons found in N=2 field theory by Douglas and Shenker are reproduced. It is seen that in the N=1 limit all but one such meson disappears while all of the strings survive. The strings of softly broken N=2, N=1, and even non-supersymmetric SU(N) MQCD have a common ratio for their tensions as a function of the amount of flux they carry. We also comment on the almost BPS properties of the Douglas-Shenker strings and discuss the brane picture for monopole confinement on N=2 QCD Higgs branches. (orig.)

NASA Net Zero Energy Buildings Roadmap

Energy Technology Data Exchange (ETDEWEB)

Pless, S.; Scheib, J.; Torcellini, P.; Hendron, B.; Slovensky, M.

2014-10-01

In preparation for the time-phased net zero energy requirement for new federal buildings starting in 2020, set forth in Executive Order 13514, NASA requested that the National Renewable Energy Laboratory (NREL) to develop a roadmap for NASA's compliance. NASA detailed a Statement of Work that requested information on strategic, organizational, and tactical aspects of net zero energy buildings. In response, this document presents a high-level approach to net zero energy planning, design, construction, and operations, based on NREL's first-hand experience procuring net zero energy construction, and based on NREL and other industry research on net zero energy feasibility. The strategic approach to net zero energy starts with an interpretation of the executive order language relating to net zero energy. Specifically, this roadmap defines a net zero energy acquisition process as one that sets an aggressive energy use intensity goal for the building in project planning, meets the reduced demand goal through energy efficiency strategies and technologies, then adds renewable energy in a prioritized manner, using building-associated, emission- free sources first, to offset the annual energy use required at the building; the net zero energy process extends through the life of the building, requiring a balance of energy use and production in each calendar year.

Critical quench dynamics in confined systems.

Science.gov (United States)

Collura, Mario; Karevski, Dragi

2010-05-21

We analyze the coherent quantum evolution of a many-particle system after slowly sweeping a power-law confining potential. The amplitude of the confining potential is varied in time along a power-law ramp such that the many-particle system finally reaches or crosses a critical point. Under this protocol we derive general scaling laws for the density of excitations created during the nonadiabatic sweep of the confining potential. It is found that the mean excitation density follows an algebraic law as a function of the sweeping rate with an exponent that depends on the space-time properties of the potential. We confirm our scaling laws by first order adiabatic calculation and exact results on the Ising quantum chain with a varying transverse field.

RESTful NET

CERN Document Server

Flanders, Jon

2008-01-01

RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

Getting to Net Zero

Energy Technology Data Exchange (ETDEWEB)

2016-09-01

The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

Net Zero Energy Buildings

DEFF Research Database (Denmark)

Marszal, Anna Joanna; Bourrelle, Julien S.; Gustavsen, Arild

2010-01-01

and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...

Pro NET Best Practices

CERN Document Server

Ritchie, Stephen D

2011-01-01

Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

Achieving effective confinement through utilization of non-Newtonian fluid mixture as stemming structure

Directory of Open Access Journals (Sweden)

Luís Felipe Gomes Marinho

Full Text Available Abstract The economics of a mining operation is directly influenced by blasting outcomes, where blasting aims to comminute the rock mass in order to attain smaller grain sizes to be loaded and hauled at a minimum cost for its first processing stage. In order to promote adequate rock breakage, the stemming structure needs to provide proper confinement for the borehole charged with explosives, reflecting the energy released during the detonation in form of shock waves and gases to act throughout the in situ rock mass, enlarging its failures and fractures, and also creating new ones. To build up a stemming column, literature recommends the usage of dry granular materials instead of elements with plastic behavior. However, a study was performed using Gypsum plaster as stemming; a kind of material that exhibits solid-like behavior when it is dry. Following this theory, this test verified improvements regarding confinement effectiveness and energy propagation throughout the rock mass when a non-Newtonian mixture (NNM was applied as stemming; a material that shows a solid-like behavior when is under shear stress. When the stemming arrangement was composed of NNM, it was able to reduce energy and gas losses to the atmosphere, because of the liquid's property of filling voids into the borehole. The NNM yielded high results due to its better confinement effectiveness, a reduction of air overpressure, and an increase of the strain propagation and ground vibration throughout the rock.

ASP.NET web API build RESTful web applications and services on the .NET framework

CERN Document Server

Kanjilal, Joydip

2013-01-01

This book is a step-by-step, practical tutorial with a simple approach to help you build RESTful web applications and services on the .NET framework quickly and efficiently.This book is for ASP.NET web developers who want to explore REST-based services with C# 5. This book contains many real-world code examples with explanations whenever necessary. Some experience with C# and ASP.NET 4 is expected.

Crack tip stress and strain

International Nuclear Information System (INIS)

Francois, D.

1975-01-01

The study of potential energy variations in a loaded elastic solid containing a crack leads to determination of the crack driving force G. Generalization of this concept to cases other than linear elasticity leads to definition of the integral J. In a linear solid, the crack tip stress field is characterized by a single parameter: the stress-intensity factor K. When the crack tip plastic zone size is confined to the elastic singularity J=G, it is possible to establish relationship between these parameters and plastic strain (and in particular the crack tip opening displacement delta). The stress increases because of the triaxiality effect. This overload rises with increasing strain hardening. When the plastic zone size expands, using certain hypotheses, delta can be calculated. The plastic strain intensity is exclusively dependent on parameter J [fr

Computation of shrinkage stresses in prestressed concrete containments

International Nuclear Information System (INIS)

Wu, R.F.; Ouyang, H.

1989-01-01

According to a survey, surface cracking on PCRVs and PCCs under the investigations is confined to drying shrinkage and thermal strain effects and no instances of structurally significant cracking was been found. In this paper, the authors use FEM to compute humidity distribution in drying concrete and shrinkage stresses by internal restraint. Since PCC is built segment by segment in several years, a computational model taking into account construction sequence is presented and shrinkage stresses by external restraints are calculated with the model

Translating Colored Control Flow Nets into Readable Java via Annotated Java Workflow Nets

DEFF Research Database (Denmark)

Lassen, Kristian Bisgaard; Tjell, Simon

2007-01-01

In this paper, we present a method for developing Java applications from Colored Control Flow Nets (CCFNs), which is a special kind of Colored Petri Nets (CPNs) that we introduce. CCFN makes an explicit distinction between the representation of: The system, the environment of the system, and the ......In this paper, we present a method for developing Java applications from Colored Control Flow Nets (CCFNs), which is a special kind of Colored Petri Nets (CPNs) that we introduce. CCFN makes an explicit distinction between the representation of: The system, the environment of the system......, and the interface between the system and the environment. Our translation maps CCFNs into Anno- tated Java Workflow Nets (AJWNs) as an intermediate step, and these AJWNs are finally mapped to Java. CCFN is intended to enforce the modeler to describe the system in an imperative manner which makes the subsequent...... translation to Java easier to define. The translation to Java preserves data dependencies and control-flow aspects of the source CCFN. This paper contributes to the model-driven software development paradigm, by showing how to model a system, environment, and their interface, as a CCFN and presenting a fully...

Programming NET 35

CERN Document Server

Liberty, Jesse

2009-01-01

Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

Enhancement of confinement in tokamaks

International Nuclear Information System (INIS)

Furth, H.P.

1986-05-01

A plausible interpretation of the experimental evidence is that energy confinement in tokamaks is governed by two separate considerations: (1) the need for resistive MHD kink-stability, which limits the permissible range of current profiles - and therefore normally also the range of temperature profiles; and (2) the presence of strongly anomalous microscopic energy transport near the plasma edge, which calibrates the amplitude of the global temperature profile, thus determining the energy confinement time tau/sub E/. Correspondingly, there are two main paths towards the enhancement of tokamak confinement: (1) Configurational optimization, to increase the MHD-stable energy content of the plasma core, can evidently be pursued by varying the cross-sectional shape of the plasma and/or finding stable radial profiles with central q-values substantially below unity - but crossing from ''first'' to ''second'' stability within the peak-pressure region would have the greatest ultimate potential. (2) Suppression of edge turbulence, so as to improve the heat insulation in the outer plasma shell, can be pursued by various local stabilizing techniques, such as use of a poloidal divertor. The present confinement model and initial TFTR pellet-injection results suggest that the introduction of a super-high-density region within the plasma core should be particularly valuable for enhancing ntau/subE/. In D-T operation, a centrally peaked plasma pressure profile could possibly lend itself to alpha-particle-driven entry into the second-stability regime

Net metering: zero electricity bill

International Nuclear Information System (INIS)

Mangi, A.; Khan, Z.

2011-01-01

Worldwide move towards renewable energy sources, environmental concerns and decentralization of the power sector have made net metering an attractive option for power generation at small scale. This paper discusses the net metering, economical issues of renewable sources in Pakistan, technical aspects, installation suitability according to varying terrain, existing utility rules and formulation of legislation for net metering making it economically attractive. (author)

Fluorescence Microscopy of Nanochannel-Confined DNA.

Science.gov (United States)

Westerlund, Fredrik; Persson, Fredrik; Fritzsche, Joachim; Beech, Jason P; Tegenfeldt, Jonas O

2018-01-01

Stretching of DNA in nanoscale confinement allows for several important studies. The genetic contents of the DNA can be visualized on the single DNA molecule level and both the polymer physics of confined DNA and also DNA/protein and other DNA/DNA-binding molecule interactions can be explored. This chapter describes the basic steps to fabricate the nanostructures, perform the experiments and analyze the data.

Development-specific responses to drought stress in Aleppo pine (Pinus halepensis Mill.) seedlings.

Science.gov (United States)

Alexou, Maria

2013-10-01

Aleppo pine (Pinus halepensis Mill.) is a pioneer species, highly competitive due to exceptional resistance to drought. To investigate the stress resistance in the first and second year of development, a steady-state drought experiment was implemented. Photosynthesis (A(net)), stomatal conductance and transpiration (E) were measured on three different sampling dates together with phloem soluble sugars, amino acids and non-structural proteins. Needle ascorbic acid (AsA) and reactive oxygen species were measured to evaluate the seedlings' drought stress condition in the final sampling. Drought impaired A(net) and E by 35 and 31%, respectively, and increased AsA levels up to 10-fold, without significant impact on the phloem metabolites. Phloem sugars related to temperature fluctuations rather than soil moisture and did not relate closely to A(net) levels. Sugars and proteins decreased between the second and third sampling date by 56 and 61%, respectively, and the ratio of sugars to amino acids decreased between the first and third sampling by 81%, while A(net) and water-use efficiency (A(net)/E) decreased only in the older seedlings. Although gas exchange was higher in the older seedlings, ascorbic acid and phloem metabolites were higher in the younger seedlings. It was concluded that the drought stress responses depended significantly on developmental stage, and research on the physiology of Aleppo pine regeneration should focus more on temperature conditions and the duration of drought than its severity.

Dynamic Failure Processes Under Confining Stress in AlON, a Transparent Polycrystalline Ceramic

Science.gov (United States)

2009-09-01

homogeneous compressive stress state in the specimen, a 500 µm thick, soft-annealed AISI 4140 steel ‘cushion’ is sandwiched between the specimen and the...1. The AlON prismatic specimen (shown in green in the figure) is placed between two very hard steel “T-blocks” made from ~ HRC 55 hardened AISI ... 4140 steel alloy. The blocks were polished to obtain precise dimensions and a mirror surface finish. Compressive stress was generated by tightening

Behaviour of FRP confined concrete in square columns

OpenAIRE

Diego Villalón, Ana de; Arteaga Iriarte, Ángel; Fernandez Gomez, Jaime Antonio; Perera Velamazán, Ricardo; Cisneros, Daniel

2015-01-01

A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and duc...

The treatment of residual stress in fracture assessment of pressure vessels

International Nuclear Information System (INIS)

Green, D.; Knowles, J.

1992-01-01

The treatment of weld residual stress in the fracture assessment of cylindrical pressure vessels is considered through partitioning the stress into membrane, bending and self-balancing through wall components. The influence of each on fracture behavior is discussed. Stress intensity factor solutions appropriate to each type of stress are presented. Short range, medium range and long range stress categories are identified according to simple rules relating the effect of increasing crack length to stress intensity factor and ligament net stress. Proposals are made on how the stress intensity factor from these stress types may be incorporated into a Kr, Lr based fracture assessment

Hermitian relativity, chromodynamics and confinement

International Nuclear Information System (INIS)

Treder, H.J.

1983-01-01

The extension of the Riemann metrics of General Relativity to the complex domain (substitution of the symmetry conditions for the fundamental tensor, the affinity and the Ricci curvature by the conditions of hermicity) leads to a 'Generalized Theory of Gravity' (Einstein) describing the Newton-Einstein gravodynamics combined with the chromodynamics of quarks. The interaction of gravodynamics and chromodynamics implied by the Einstein-Schroedinger field equations of the hermitian relativity theory enforces the 'confinement'. The 'confinement' prevents the gravitational potential from divergence which would result in the lack of a Riemann space-time metric

Finite temperature approach to confinement

International Nuclear Information System (INIS)

Gave, E.; Jengo, R.; Omero, C.

1980-06-01

The finite temperature treatment of gauge theories, formulated in terms of a gauge invariant variable as in a Polyakov method, is used as a device for obtaining an effective theory where the confinement test takes the form of a correlation function. The formalism is discussed for the abelian CPsup(n-1) model in various dimensionalities and for the pure Yang-Mills theory in the limit of zero temperature. In the latter case a class of vortex like configurations of the effective theory which induce confinement correspond in particular to the instanton solutions. (author)

Pellet injection and toroidal confinement

International Nuclear Information System (INIS)

1989-12-01

The proceedings of a technical committee meeting on pellet injection and toroidal confinement, held in Gut Ising, Federal Republic of Germany, 24-26 October, 1988, are given in this report. Most of the major fusion experiments are using pellet injectors; these were reported at this meeting. Studies of confinement, which is favorably affected, impurity transport, radiative energy losses, and affects on the ion temperature gradient instability were given. Studies of pellet ablation and effects on plasma profiles were presented. Finally, several papers described present and proposed injection guns. Refs, figs and tabs

INERT Atmosphere confinement operability test procedure

International Nuclear Information System (INIS)

RISENMAY, H.R.

1999-01-01

This Operability Test Procedure (OTP) provides instructions for testing operability of the Inert Atmosphere Confinement (IAC). The Inert Atmosphere Confinement was designed and built for opening cans of metal items that might have hydrided surfaces. Unreviewed Safety Question (USQ) PFP-97-005 addresses the discovery of suspected plutonium hydride forming on plutonium metal currently stored in the Plutonium Finishing Plant vaults. Plutonium hydride reacts quickly with air, liberating energy. The Inert Atmosphere Confinement was designed to prevent this sudden liberation of energy by opening the material in an inert argon atmosphere instead of the normal glovebox atmosphere. The IAC is located in glovebox HC-21A, room 230B of the 234-5Z Building at the Plutonium Finishing Plant (PFP) in the 200-West Area of the Hanford Site

Deep processes in non-relativistic confining potentials

International Nuclear Information System (INIS)

Fishbane, P.M.; Grisaru, M.T.

1978-01-01

The authors study deep inelastic and hard scattering processes for non-relativistic particles confined in deep potentials. The mechanisms by which the effects of confinement disappear and the particles scatter as if free are useful in understanding the analogous results for a relativistic field theory. (Auth.)

Potential Role of Inorganic Confined Environments in Prebiotic Phosphorylation.

Science.gov (United States)

Dass, Avinash Vicholous; Jaber, Maguy; Brack, André; Foucher, Frédéric; Kee, Terence P; Georgelin, Thomas; Westall, Frances

2018-03-05

A concise outlook on the potential role of confinement in phosphorylation and phosphate condensation pertaining to prebiotic chemistry is presented. Inorganic confinement is a relatively uncharted domain in studies concerning prebiotic chemistry, and even more so in terms of experimentation. However, molecular crowding within confined dimensions is central to the functioning of contemporary biology. There are numerous advantages to confined environments and an attempt to highlight this fact, within this article, has been undertaken, keeping in context the limitations of aqueous phase chemistry in phosphorylation and, to a certain extent, traditional approaches in prebiotic chemistry.

Interaction between confined phonons and photons in periodic silicon resonators

Science.gov (United States)

Iskandar, A.; Gwiazda, A.; Younes, J.; Kazan, M.; Bruyant, A.; Tabbal, M.; Lerondel, G.

2018-03-01

In this paper, we demonstrate that phonons and photons of different momenta can be confined and interact with each other within the same nanostructure. The interaction between confined phonons and confined photons in silicon resonator arrays is observed by means of Raman scattering. The Raman spectra from large arrays of dielectric silicon resonators exhibited Raman enhancement accompanied with a downshift and broadening. The analysis of the Raman intensity and line shape using finite-difference time-domain simulations and a spatial correlation model demonstrated an interaction between photons confined in the resonators and phonons confined in highly defective regions prompted by the structuring process. It was shown that the Raman enhancement is due to collective lattice resonance inducing field confinement in the resonators, while the spectra downshift and broadening are signatures of the relaxation of the phonon wave vector due to phonon confinement in defective regions located in the surface layer of the Si resonators. We found that as the resonators increase in height and their shape becomes cylindrical, the amplitude of their coherent oscillation increases and hence their ability to confine the incoming electric field increases.

Improved confinement in L-mode JET plasmas

International Nuclear Information System (INIS)

Jones, T.T.C.; Balet, B.; Bhatnagar, V.; Bures, M.; Campbell, D.J.; Christiansen, J.P.; Cordey, J.G.; Core, W.F.; Corti, S.; Costley, A.E.; Cottrell, G.A.; Edwards, A.; Ehrenberg, J.; Jacquinot, J.; Lallia, P.; Lomas, P.J.; Lowry, C.; Malacarne, M.; Muir, D.G.; Nave, M.F.; Nielsen, P.; Sack, C.; Sadler, G.; Start, D.F.H.; Taroni, A.; Thomas, P.R.; Thomsen, K.

1989-01-01

The JET confinement data show considerable variations of stored plasma energy W (thermal + fast ions) at fixed input power P, plasma current I, toroidal field B and plasma configuration C. The data on confinement properties, e.g. the confinement time τ E or its incremental value τ E (inc), derived from variations of P at fixed I, B, C thus exhibit scatter which makes the scaling of τ E with P, I, B, C difficult to establish. The effects from sawteeth, from variations in the power deposition profiles and from plasma edge physics on confinement do not depend on P, I, B, C in any simple way which would permit a deduced scaling law to be identified with a single (or more) physics loss mechanism(s). In this paper we examine the response of confinement to variations in plasma configuration at fixed I and B (3 MA and 3 T). Results from global and local transport analysis are discussed in sections 2 and 3; section 4 describes the role of fast ions produced by ICRF and NBI heating. High confinement in the L-mode regime at increased plasma currents up to 6 MA is also studied, in particular the effects from sawteeth on stored energy W. Such effects increase with current and presently only predictive transport studies (section 5) can estimate what may be achieved at high current without sawteeth effects. The predictive studies also assess the benefits which may arise from an increase of the neutral beam energy at high plasma currents (section 6). The conclusions are based on extensive study of data from JET pulses with up to 14 MW of ICRH, 21 MW of NBI and 6 MW of ohmic power. None of the pulses included in the study show the sudden reduction of D α emission characteristic of the L to H mode transition of confinement. 7 refs., 4 figs

Net Locality

DEFF Research Database (Denmark)

de Souza e Silva, Adriana Araujo; Gordon, Eric

Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

Construction of monophase nets

International Nuclear Information System (INIS)

Suarez A, Jose Antonio

1996-01-01

The paper refers to the use of monophase loads in commercial residential urbanizations and in small industries, for this reason it is considered unnecessary the construction of three-phase nets. The author makes a historical recount of these nets in Bogota, his capacities, uses and energy savings

Qualitative quark confinement

International Nuclear Information System (INIS)

Jackson, T.L.

1976-01-01

The infrared limit in asymptotically free non-abelian gauge theories using recently developed non-perturbative methods which allow derivation of zero momentum theorems for Green's functions and vertices is described. These low-energy theorems are compared to the infrared behavior predicted from the renormalization group equation when the existence of an infrared fixed point is assumed. A set of objects is exhibited whose low energy theorems violate the scaling behavior predicted by the renormalization group. This shows that the assumed fixed point cannot exist and that in the Landau gauge the effective charge becomes infinite in the infrared. Qualitatively this implies that as an attempt is made to separate elementary quanta the interaction between the quanta becomes arbitrarily strong. This indicates at least that the theories studied are capable of color confinement. Results are true only for theories with large numbers of quarks. This opens the possibility that large numbers of quarks are actually necessary for confinement

Greater-confinement disposal

International Nuclear Information System (INIS)

Trevorrow, L.E.; Schubert, J.P.

1989-01-01

Greater-confinement disposal (GCD) is a general term for low-level waste (LLW) disposal technologies that employ natural and/or engineered barriers and provide a degree of confinement greater than that of shallow-land burial (SLB) but possibly less than that of a geologic repository. Thus GCD is associated with lower risk/hazard ratios than SLB. Although any number of disposal technologies might satisfy the definition of GCD, eight have been selected for consideration in this discussion. These technologies include: (1) earth-covered tumuli, (2) concrete structures, both above and below grade, (3) deep trenches, (4) augered shafts, (5) rock cavities, (6) abandoned mines, (7) high-integrity containers, and (8) hydrofracture. Each of these technologies employ several operations that are mature,however, some are at more advanced stages of development and demonstration than others. Each is defined and further described by information on design, advantages and disadvantages, special equipment requirements, and characteristic operations such as construction, waste emplacement, and closure

Caught in the Net: Perineuronal Nets and Addiction

Directory of Open Access Journals (Sweden)

Megan Slaker

2016-01-01

Full Text Available Exposure to drugs of abuse induces plasticity in the brain and creates persistent drug-related memories. These changes in plasticity and persistent drug memories are believed to produce aberrant motivation and reinforcement contributing to addiction. Most studies have explored the effect drugs of abuse have on pre- and postsynaptic cells and astrocytes; however, more recently, attention has shifted to explore the effect these drugs have on the extracellular matrix (ECM. Within the ECM are unique structures arranged in a net-like manner, surrounding a subset of neurons called perineuronal nets (PNNs. This review focuses on drug-induced changes in PNNs, the molecules that regulate PNNs, and the expression of PNNs within brain circuitry mediating motivation, reward, and reinforcement as it pertains to addiction.

Curvature of random walks and random polygons in confinement

International Nuclear Information System (INIS)

Diao, Y; Ernst, C; Montemayor, A; Ziegler, U

2013-01-01

The purpose of this paper is to study the curvature of equilateral random walks and polygons that are confined in a sphere. Curvature is one of several basic geometric properties that can be used to describe random walks and polygons. We show that confinement affects curvature quite strongly, and in the limit case where the confinement diameter equals the edge length the unconfined expected curvature value doubles from π/2 to π. To study curvature a simple model of an equilateral random walk in spherical confinement in dimensions 2 and 3 is introduced. For this simple model we derive explicit integral expressions for the expected value of the total curvature in both dimensions. These expressions are functions that depend only on the radius R of the confinement sphere. We then show that the values obtained by numeric integration of these expressions agrees with numerical average curvature estimates obtained from simulations of random walks. Finally, we compare the confinement effect on curvature of random walks with random polygons. (paper)

Percolating cluster of center vortices and confinement

International Nuclear Information System (INIS)

Gliozzi, Ferdinando; Panero, Marco; Provero, Paolo

2003-01-01

We study the role of percolating clusters of center vortices in configurations of an Ising gauge theory in 3D. It is known that low energy features of gauge theories can be described in terms of an 'effective string picture', and that confinement properties are associated with topologically non-trivial configurations. We focus our attention upon percolating clusters of center vortices, and present numerical evidence for the fact that these objects play a preminent role in confinement phenomenon, since their removal sweeps off confinement altogether. Moreover, numerical simulations show that the string fluctuations, and in particular the Mischer term, are completely encoded in the percolating cluster

Method for confining the magnetic field of the cross-tail current inside the magnetopause

Science.gov (United States)

Sotirelis, T.; Tsyganenko, N. A.; Stern, D. P.

1994-01-01

A method is presented for analytically representing the magnetic field due to the cross-tail current and its closure on the magnetopause. It is an extension of a method used by Tsyganenko (1989b) to confine the dipole field inside an ellipsoidal magnetopause using a scalar potential. Given a model of the cross-tail current, the implied net magnetic field is obtained by adding to the cross-tail current field a potential field B = - del gamma, which makes all field lines divide into two disjoint groups, separated by the magnetopause (i.e., the combined field is made to have zero normal component with the magnetopause). The magnetopause is assumed to be an ellipsoid of revolution (a prolate spheroid) as an approximation to observations (Sibeck et al., 1991). This assumption permits the potential gamma to be expressed in spheroidal coordinates, expanded in spheroidal harmonics and its terms evaluated by performing inversion integrals. Finally, the field outside the magnetopause is replaced by zero, resulting in a consistent current closure along the magnetopause. This procedure can also be used to confine the modeled field of any other interior magnetic source, though the model current must always flow in closed circuits. The method is demonstrated on the T87 cross-tail current, examples illustrate the effect of changing the size and shape of the prescribed magnetopause and a comparison is made to an independent numerical scheme based on the Biot-Savart equation.

3D characterization of coal strains induced by compression, carbon dioxide sorption, and desorption at in-situ stress conditions

Energy Technology Data Exchange (ETDEWEB)

Pone, J. Denis N.; Halleck, Phillip M.; Mathews, Jonathan P. [Department of Energy and Mineral Engineering and The EMS Energy Institute, The Pennsylvania State University, University Park, PA 16802 (United States)

2010-06-01

Sequestration of carbon dioxide in unmineable coal seams is an option to combat climate change and an opportunity to enhance coalbed methane production. Prediction of sequestration potential in coal requires characterization of porosity, permeability, sorption capacity and the magnitude of swelling due to carbon dioxide uptake or shrinkage due to methane and water loss. Unfortunately, the majority of data characterizing coal-gas systems have been obtained from powdered, unconfined coal samples. Little is known about confined coal behavior during carbon dioxide uptake and methane desorption. The present work focuses on the characterization of lithotype specific deformation, and strain behavior during CO{sub 2} uptake at simulated in-situ stress conditions. It includes the evaluation of three-dimensional strain induced by the confining stress, the sorption, and the desorption of carbon dioxide. X-ray computed tomography allowed three-dimensional characterization of the bituminous coal deformation samples under hydrostatic stress. The application of 6.9 MPa of confining stress contributes an average of - 0.34% volumetric strain. Normal strains due to confining stress were - 0.08%, - 0.15% and - 0.11% along the x, y and z axes respectively. Gas injection pressure was 3.1 MPa and the excess sorption was 0.85 mmol/g. Confined coal exposed to CO{sub 2} for 26 days displays an average volumetric expansion of 0.4%. Normal strains due to CO{sub 2} sorption were 0.11%, 0.22% and 0.11% along x, y and z axes. Drainage of the CO{sub 2} induced an average of - 0.33% volumetric shrinkage. Normal strains due to CO{sub 2} desorption were - 0.23%, - 0.08% and - 0.02% along x, y and z axes. Alternating positive and negative strain values observed along the sample length during compression, sorption and desorption respectively emphasized that both localized compression/compaction and expansion of coal will occur during CO{sub 2} sequestration. (author)

The K-NET - A year after

International Nuclear Information System (INIS)

Kinoshita, S.; Ohtani, K.; Katayama, T.

2001-01-01

We started to release the K-NET strong-motion data from June 1996 and about one year passed. In this article, we report the development of K-NET and some applications using the K-NET information released on the Internet. (author)

Spatial and Temporal Stress Drop Variations of the 2011 Tohoku Earthquake Sequence

Science.gov (United States)

Miyake, H.

2013-12-01

The 2011 Tohoku earthquake sequence consists of foreshocks, mainshock, aftershocks, and repeating earthquakes. To quantify spatial and temporal stress drop variations is important for understanding M9-class megathrust earthquakes. Variability and spatial and temporal pattern of stress drop is a basic information for rupture dynamics as well as useful to source modeling. As pointed in the ground motion prediction equations by Campbell and Bozorgnia [2008, Earthquake Spectra], mainshock-aftershock pairs often provide significant decrease of stress drop. We here focus strong motion records before and after the Tohoku earthquake, and analyze source spectral ratios considering azimuth- and distance dependency [Miyake et al., 2001, GRL]. Due to the limitation of station locations on land, spatial and temporal stress drop variations are estimated by adjusting shifts from the omega-squared source spectral model. The adjustment is based on the stochastic Green's function simulations of source spectra considering azimuth- and distance dependency. We assumed the same Green's functions for event pairs for each station, both the propagation path and site amplification effects are cancelled out. Precise studies of spatial and temporal stress drop variations have been performed [e.g., Allmann and Shearer, 2007, JGR], this study targets the relations between stress drop vs. progression of slow slip prior to the Tohoku earthquake by Kato et al. [2012, Science] and plate structures. Acknowledgement: This study is partly supported by ERI Joint Research (2013-B-05). We used the JMA unified earthquake catalogue and K-NET, KiK-net, and F-net data provided by NIED.

Confined granular flow in silos experimental and numerical investigations

CERN Document Server

Tejchman, Jacek

2013-01-01

  During confined flow of bulk solids in silos some characteristic phenomena can be created, such as: —         sudden and significant increase of wall stresses, —         different flow patterns, —         formation and propagation of wall and interior shear zones, —         fluctuation of pressures and, —         strong autogenous dynamic effects. These phenomena have not been described or explained in detail yet. The main intention of the experimental and theoretical research presented in this book is to explain the above mentioned phenomena in granular bulk solids and to describe them with numerical FE models verified by experimental results.

Mars MetNet Mission Status

Science.gov (United States)

Harri, A.-M.; Aleksashkin, S.; Arruego, I.; Schmidt, W.; Genzer, M.; Vazquez, L.; Haukka, H.; Palin, M.; Nikkanen, T.

2015-10-01

New kind of planetary exploration mission for Mars is under development in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA). The Mars MetNet mission is based on a new semihard landing vehicle called MetNet Lander (MNL). The scientific payload of the Mars MetNet Precursor [1] mission is divided into three categories: Atmospheric instruments, Optical devices and Composition and structure devices. Each of the payload instruments will provide significant insights in to the Martian atmospheric behavior. The key technologies of the MetNet Lander have been qualified and the electrical qualification model (EQM) of the payload bay has been built and successfully tested.

FRP-Confined Recycled Coarse Aggregate Concrete: Experimental Investigation and Model Comparison

Directory of Open Access Journals (Sweden)

Yingwu Zhou

2016-10-01

Full Text Available The in situ application of recycled aggregate concrete (RAC is of great significance in environmental protection and construction resources sustainability. However, it has been limited to nonstructural purposes due to its poor mechanical performance. External confinement using steel tubes and fiber-reinforced polymer (FRP can significantly improve the mechanical performance of RAC and thus the first-ever study on the axial compressive behavior of glass FRP (GFRP-confined RAC was recently reported. To have a full understanding of FRP-confined RAC, this paper has extended the type of FRP and presents a systematic experimental study on the axial compressive performance of carbon FRP (CFRP-confined RAC. The mechanical properties of CFRP-confined RAC from the perspective of the failure mode, ultimate strength and strain, and stress–strain relationship responses were analyzed. Integrated with existing experimental data of FRP-confined RAC, the paper compiles a database for the mechanical properties of FRP-confined RAC. Based on the database, the effects of FRP type (i.e., GFRP and CFRP and the replacement ratio of recycled coarse aggregate were investigated. The results indicated that the stress–stain behavior of FRP-confined RAC depended heavily on the unconfined concrete strength and the FRP confining pressure instead of the replacement ratio. Therefore, this study adopted eleven high-performance ultimate strength and strain models developed for FRP-confined normal aggregate concrete (NAC to predict the mechanical properties of FRP-confined RAC. All the predictions had good agreement with the test results, which further confirmed similar roles played by FRP confinement in improving the mechanical properties of RAC and improving those of NAC. On this basis, this paper finally recommended a stress–strain relationship model for FRP-confined RAC.

NET SALARY ADJUSTMENT

CERN Multimedia

Finance Division

2001-01-01

On 15 June 2001 the Council approved the correction of the discrepancy identified in the net salary adjustment implemented on 1st January 2001 by retroactively increasing the scale of basic salaries to achieve the 2.8% average net salary adjustment approved in December 2000. We should like to inform you that the corresponding adjustment will be made to your July salary. Full details of the retroactive adjustments will consequently be shown on your pay slip.

Structure and spectra of a confined HeH molecule

International Nuclear Information System (INIS)

Lo, J M H; Klobukowski, M; Bielinska-Wacz, D; Schreiner, E W S; Diercksen, G H F

2006-01-01

The influence of spatial confinement on the structure and spectra of the Rydberg HeH molecule is analysed at the level of the variational full configuration interaction approach. The confining potential is assumed to have cylindrical symmetry, with the symmetry axis of the potential overlapping with the molecular bond. In the direction perpendicular to the axis quadratic dependence of the potential on the electron coordinates is assumed. The influence of the confining potential on the form of the potential energy curves (in particular on the bond lengths), on the electronic spectra and on the ionization due to the confinement is studied in detail

The cruel and unusual phenomenology of solitary confinement

OpenAIRE

Shaun eGallagher; Shaun eGallagher; Shaun eGallagher

2014-01-01

What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a cruel and unusual punishment, there is no consensus on the definition of the term ‘cruel’ in the use of that legal phrase. I argue that we ...

Entropic transport without external force in confined channel with oscillatory boundary

Energy Technology Data Exchange (ETDEWEB)

Ding, Huai; Jiang, Huijun; Hou, Zhonghuai, E-mail: hzhlj@ustc.edu.cn [Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at Microscales, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2015-12-28

The dynamics of point-like Brownian particles in a periodic confined channel with oscillating boundaries has been studied. Directional transport (DT) behavior, characterized by net displacement along the horizontal direction, is observed even without external force which is necessary for the conventional DT where the boundaries are static. For typical parameter values, the average velocity V{sub t} of DT reaches a maximum with the variation of the noise intensity D, being alike to the phenomenon of stochastic resonance. Interestingly, we find that V{sub t} shows nontrivial dependences on the particle gravity G depending on the noise level. When the noise is large, V{sub t} increases monotonically with G indicating that heavier particle moves faster, while for small noise, V{sub t} shows a bell-shape dependence on G, suggesting that a particle with an intermediate weight may move the fastest. Such results were not observed for DT in a channel with static boundaries. To understand these findings, we have adopted an effective one-dimensional coarsening description, which facilitates us to introduce an effective entropic force along the horizontal direction. The average force is apparently nonzero due to the oscillatory boundary, hence leading to the net transport, and it shows similar dependences as V{sub t} on the noise intensity D and particle gravity G. The dependences of the DT behavior on other parameters describing the oscillatory channel have also been investigated, showing that DT is more pronounced for larger oscillation amplitude and frequency, and asymmetric geometry within a channel period and phase difference between neighboring periods are both necessary for the occurrence of DT.

Confined catalysis under two-dimensional materials

OpenAIRE

Li, Haobo; Xiao, Jianping; Fu, Qiang; Bao, Xinhe

2017-01-01

Small spaces in nanoreactors may have big implications in chemistry, because the chemical nature of molecules and reactions within the nanospaces can be changed significantly due to the nanoconfinement effect. Two-dimensional (2D) nanoreactor formed under 2D materials can provide a well-defined model system to explore the confined catalysis. We demonstrate a general tendency for weakened surface adsorption under the confinement of graphene overlayer, illustrating the feasible modulation of su...

Chiral symmetry breaking and confinement - solutions of relativistic wave equations

International Nuclear Information System (INIS)

Murugesan, P.

1983-01-01

In this thesis, an attempt is made to explore the question whether confinement automatically leads to chiral symmetry breaking. While it should be accepted that chiral symmetry breaking manifests in nature in the absence of scalar partners of pseudoscalar mesons, it does not necessarily follow that confinement should lead to chiral symmetry breaking. If chiral conserving forces give rise to observed spectrum of hadrons, then the conjuncture that confinement is responsible for chiral symmetry breaking is not valid. The method employed to answer the question whether confinement leads to chiral symmetry breaking or not is to solve relativistic wave equations by introducing chiral conserving as well as chiral breaking confining potentials and compare the results with experimental observations. It is concluded that even though chiral symmetry is broken in nature, confinement of quarks need not be the cause of it

CONFINEMENT OF HIGH TEMPERATURE PLASMA

Science.gov (United States)

Koenig, H.R.

1963-05-01

The confinement of a high temperature plasma in a stellarator in which the magnetic confinement has tended to shift the plasma from the center of the curved, U-shaped end loops is described. Magnetic means are provided for counteracting this tendency of the plasma to be shifted away from the center of the end loops, and in one embodiment this magnetic means is a longitudinally extending magnetic field such as is provided by two sets of parallel conductors bent to follow the U-shaped curvature of the end loops and energized oppositely on the inside and outside of this curvature. (AEC)

Net energy gain from DT fusion

International Nuclear Information System (INIS)

Buende, R.

1985-01-01

The net energy which can be gained from an energy raw material by means of a certain conversion system is deduced as the figure-of-merit which adequately characterizes the net energy balance of utilizing an energy source. This potential net energy gain is determined for DT fusion power plants. It is represented as a function of the degree of exploitation of the energy raw material lithium ore and is compared with the net energy which can be gained with LW and FBR power plants by exploiting uranium ore. The comparison clearly demonstrates the net energetic advantage of DT fusion. A sensitivity study shows that this holds even if the energy expenditure for constructing and operating is drastically increased

Net alkalinity and net acidity 2: Practical considerations

Science.gov (United States)

Kirby, C.S.; Cravotta, C.A.

2005-01-01

The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH mine drainage treatment can lead to systems with insufficient Alkalinity to neutralize metal and H+ acidity and is not recommended. The use of net alkalinity = -Hot Acidity titration is recommended for the planning of mine drainage treatment. The use of net alkalinity = (Alkalinitymeasured - Aciditycalculated) is recommended with some cautions

Bed net ownership in Kenya: the impact of 3.4 million free bed nets

Directory of Open Access Journals (Sweden)

Vulule John

2010-06-01

Full Text Available Abstract Background In July and September 2006, 3.4 million long-lasting insecticide-treated bed nets (LLINs were distributed free in a campaign targeting children 0-59 months old (CU5s in the 46 districts with malaria in Kenya. A survey was conducted one month after the distribution to evaluate who received campaign LLINs, who owned insecticide-treated bed nets and other bed nets received through other channels, and how these nets were being used. The feasibility of a distribution strategy aimed at a high-risk target group to meet bed net ownership and usage targets is evaluated. Methods A stratified, two-stage cluster survey sampled districts and enumeration areas with probability proportional to size. Handheld computers (PDAs with attached global positioning systems (GPS were used to develop the sampling frame, guide interviewers back to chosen households, and collect survey data. Results In targeted areas, 67.5% (95% CI: 64.6, 70.3% of all households with CU5s received campaign LLINs. Including previously owned nets, 74.4% (95% CI: 71.8, 77.0% of all households with CU5s had an ITN. Over half of CU5s (51.7%, 95% CI: 48.8, 54.7% slept under an ITN during the previous evening. Nearly forty percent (39.1% of all households received a campaign net, elevating overall household ownership of ITNs to 50.7% (95% CI: 48.4, 52.9%. Conclusions The campaign was successful in reaching the target population, families with CU5s, the risk group most vulnerable to malaria. Targeted distribution strategies will help Kenya approach indicator targets, but will need to be combined with other strategies to achieve desired population coverage levels.

The cruel and unusual phenomenology of solitary confinement

OpenAIRE

Gallagher, Shaun

2014-01-01

What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a “cruel and unusual punishment,” there is no consensus on the definition of the term “cruel” in the use of that legal phrase. I argue that we ca...

Measurement of suprathermal electron confinement by cyclotron transmission

International Nuclear Information System (INIS)

Kirkwood, R.; Hutchinson, I.H.; Luckhardt, S.C.; Porkolab, M.; Squire, J.P.

1990-01-01

The confinement time of suprathermal electrons is determined experimentally from the distribution function determined via wave transmission measurements. Measurements of the lowest moment of the distribution perpendicular to the B field as a function of the parallel electron momentum as well as the global input power allow the suprathermal electron confinement time (τ se ) to be calculated during lower-hybrid and inductive current drive. Finite particle confinement is found to be the dominant energy loss term for the suprathermals and improves with plasma current and density

47 CFR 65.450 - Net income.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net income. 65.450 Section 65.450... OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Exchange Carriers § 65.450 Net income. (a) Net income shall consist of all revenues derived from the provision of interstate telecommunications services...

Business Profile of Boat Lift Net and Stationary Lift Net Fishing Gear in Morodemak Waters Central Java

Science.gov (United States)

Hapsari, Trisnani D.; Jayanto, Bogi B.; Fitri, Aristi D. P.; Triarso, I.

2018-02-01

Lift net is one of the fishing gears that is used widely in the Morodemak coastal fishing port (PPP) for catching pelagic fish. The yield of fish captured by these fishing gear has high economic value, such as fish belt (Trichiurus sp), squids (Loligo sp) and anchovies (Stelophorus sp). The aims of this research were to determine the technical aspects of boat lift net and stationary lift net fishing gear in Morodemak Waters Demak Regency; to find out the financial aspect of those fishing gears and to analyze the financial feasibility by counting PP, NPV, IRR, and B/C ratio criteria. This research used case study method with descriptive analysis. The sampling method was purposive sampling with 22 fishermen as respondents. The result of the research showed that the average of boat lift net acceptance was Rp 388,580,000. The financial analysis of fisheries boat lift net with the result of NPV Rp 836,149,272, PP 2.44 years, IRR value 54%, and B/C ratio 1.73. The average of stationary lift net acceptance was Rp 27,750,000. The financial analysis lift net with the result of NPV Rp 37,937,601; PP 1.96 years, IRR value 86%, and B/C ratio 1.32. This research had a positive NPV value, B/C ratio >1, and IRR > discount rate (12 %). This study concluded that the fishery business of boat lift net and stationary lift net in Morodemak coastal fishing port (PPP) was worth running.

Electrostatically confined quantum rings in bilayer graphene.

Science.gov (United States)

Zarenia, M; Pereira, J M; Peeters, F M; Farias, G A

2009-12-01

We propose a new system where electron and hole states are electrostatically confined into a quantum ring in bilayer graphene. These structures can be created by tuning the gap of the graphene bilayer using nanostructured gates or by position-dependent doping. The energy levels have a magnetic field (B(0)) dependence that is strikingly distinct from that of usual semiconductor quantum rings. In particular, the eigenvalues are not invariant under a B(0) --> -B(0) transformation and, for a fixed total angular momentum index m, their field dependence is not parabolic, but displays two minima separated by a saddle point. The spectra also display several anticrossings, which arise due to the overlap of gate-confined and magnetically confined states.

Holographic repulsion and confinement in gauge theory

Science.gov (United States)

Husain, Viqar; Kothawala, Dawood

2013-02-01

We show that for asymptotically anti-de Sitter (AdS) backgrounds with negative energy, such as the AdS soliton and regulated negative-mass AdS-Schwarzshild metrics, the Wilson loop expectation value in the AdS/CFT conjecture exhibits a Coulomb to confinement transition. We also show that the quark-antiquark (q \\bar{q}) potential can be interpreted as affine time along null geodesics on the minimal string worldsheet and that its intrinsic curvature provides a signature of transition to confinement phase. Our results suggest a generic (holographic) relationship between confinement in gauge theory and repulsive gravity, which in turn is connected with singularity avoidance in quantum gravity. Communicated by P R L V Moniz

Progress in toroidal confinement and fusion research

International Nuclear Information System (INIS)

Furth, H.P.

1987-10-01

During the past 30 years, the characteristic T/sub i/n tau/sub E/-value of toroidal-confinement experiments has advanced by more than seven orders of magnitude. Part of this advance has been due to an increase of gross machine parameters. Most of this advance has been due to an increase of gross machine parameters. Most of the advance is associated with improvements in the ''quality of plasma confinement.'' The combined evidence of spherator and tokamak research clarifies the role of magnetic-field geometry in determining confinement and points to the importance of shielding out plasma edge effects. A true physical understanding of anomalous transport remains to be achieved. 39 refs., 11 figs., 1 tab

Net neutrality and audiovisual services

OpenAIRE

van Eijk, N.; Nikoltchev, S.

2011-01-01

Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

Theory of plasma confinement in non-axisymmetric magnetic fields.

Science.gov (United States)

Helander, Per

2014-08-01

The theory of plasma confinement by non-axisymmetric magnetic fields is reviewed. Such fields are used to confine fusion plasmas in stellarators, where in contrast to tokamaks and reversed-field pinches the magnetic field generally does not possess any continuous symmetry. The discussion is focussed on magnetohydrodynamic equilibrium conditions, collisionless particle orbits, and the kinetic theory of equilbrium and transport. Each of these topics is fundamentally affected by the absence of symmetry in the magnetic field: the field lines need not trace out nested flux surfaces, the particle orbits may not be confined, and the cross-field transport can be very large. Nevertheless, by tailoring the magnetic field appropriately, well-behaved equilibria with good confinement can be constructed, potentially offering an attractive route to magnetic fusion. In this article, the mathematical apparatus to describe stellarator plasmas is developed from first principles and basic elements underlying confinement optimization are introduced.

Wet scrubber technology for tritium confinement at ITER

Energy Technology Data Exchange (ETDEWEB)

Perevezentsev, A.N., E-mail: alexander.perevezentsev@iter.org [ITER Organization, CS 90 046, 13067 St Paul lez Durance Cedex (France); Andreev, B.M.; Rozenkevich, M.B.; Pak, Yu.S.; Ovcharov, A.V.; Marunich, S.A. [Mendeleev University of Chemical Technology, 125047 Miusskaya Sq. 9, Moscow (Russian Federation)

2010-12-15

Operation of the ITER machine with tritium plasma requires tritium confinement systems to protect workers and the environment. Tritium confinement at ITER is based on multistage approach. The final stage provides tritium confinement in building sectors and consists of building's walls as physical barriers and control of sub-atmospheric pressure in those volumes as a dynamic barrier. The dynamic part of the confinement function shall be provided by safety important components that are available all the time when required. Detritiation of air prior to its release to the environment is based on catalytic conversion of tritium containing gaseous species to water vapour followed by their isotopic exchange with liquid water in scrubber column of packed bed type. Wet scrubber technology has been selected because of its advantages over conventional air detritiation technique based on gas drying by water adsorption. The most important design target of system availability was very difficult to meet with conventional water adsorption driers. This paper presents results of experimental trial for validation of wet scrubber technology application in the ITER tritium confinement system and process evaluation using developed simulation computer code.

47 CFR 65.500 - Net income.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net income. 65.500 Section 65.500... OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Interexchange Carriers § 65.500 Net income. The net income methodology specified in § 65.450 shall be utilized by all interexchange carriers that are...

Aplicació Microsoft .Net : Hotel Spa

OpenAIRE

Marquès Palmer, Jordi

2010-01-01

Desenvolupament d'una aplicació amb Microsoft .NET, WCF, WPF, Linq2SQL, d'un Hotel Spa. Desarrollo de una aplicación con Microsoft .NET, WCF, WPF, Linq2SQL, de un Hotel Spa. Application development using Microsoft .NET, WCF, WPF, Linq2SQL, for a Spa Hotel.

Automatic Prompt System in the Process of Mapping plWordNet on Princeton WordNet

Directory of Open Access Journals (Sweden)

Paweł Kędzia

2015-06-01

Full Text Available Automatic Prompt System in the Process of Mapping plWordNet on Princeton WordNet The paper offers a critical evaluation of the power and usefulness of an automatic prompt system based on the extended Relaxation Labelling algorithm in the process of (manual mapping plWordNet on Princeton WordNet. To this end the results of manual mapping – that is inter-lingual relations between plWN and PWN synsets – are juxtaposed with the automatic prompts that were generated for the source language synsets to be mapped. We check the number and type of inter-lingual relations introduced on the basis of automatic prompts and the distance of the respective prompt synsets from the actual target language synsets.

Particle-confinement criteria for axisymmetric field-reversed magnetic configurations

International Nuclear Information System (INIS)

Hsiao, M.Y.; Miley, G.H.

1984-01-01

Based on two constants of motion, H and Psub(theta), where H is the total energy of a particle and Psub(theta) is its canonical angular momentum, particle confinement criteria are derived which impose constraints on H and Psub(theta). With no electric field at the ends of field-reversed magnetic configurations, confinement criteria for closed-field and absolute confinements are obtained explicitly, including both lower and upper bounds of Psub(theta)/q, where q is the charge of the species considered, for a class of Hill's vortex field-reversed magnetic configurations. The commonly used criterion for the Hamiltonian, H 0 Psub(theta), where ω 0 is identical to qB 0 /mc, is deduced from a more general form as a special case. In this special case, it is found necessary to impose a new criterion, -B 0 R 2 sub(w)/2c 0 is the vacuum field, which reduces the confinement region in (H,Psub(theta)) space. With the presence of electric fields at the ends of field-reversed magnetic configurations, confinement criteria are obtained for two interesting cases. In addition to lower and upper bounds of H, both lower and upper bounds of Psub(theta)/q are found. For axially confined particles, the lower bound of Psub(theta)/q reduces the confinement region in (H,Psub(theta)) space and represents a new criterion. These results can be applied to calculations for field-reversed mirrors and field-reversed theta pinches. (author)

Quantum-confined nanowires as vehicles for enhanced electrical transport

International Nuclear Information System (INIS)

Mohammad, S Noor

2012-01-01

Electrical transport in semiconductor nanowires taking quantum confinement and dielectric confinement into account has been studied. A distinctly new route has been employed for the study. The fundamental science underlying the model is based on a relationship between the quantum confinement and the structural disorder of the nanowire surface. The role of surface energy and thermodynamic imbalance in nanowire structural disorder has been described. A model for the diameter dependence of energy bandgap of nanowires has been developed. Ionized impurity scattering, dislocation scattering and acoustic phonon scattering have been taken into account to study carrier mobility. A series of calculations on silicon nanowires show that carrier mobility in nanowires can be greatly enhanced by quantum confinement and dielectric confinement. The electron mobility can, for example, be a factor of 2–10 higher at room temperature than the mobility in a free-standing silicon nanowire. The calculated results agree well with almost all experimental and theoretical results available in the literature. They successfully explain experimental observations not understood before. The model is general and applicable to nanowires from all possible semiconductors. It is perhaps the first physical model highlighting the impact of both quantum confinement and dielectric confinement on carrier transport. It underscores the basic causes of thin, lowly doped nanowires in the temperature range 200 K ≤ T ≤ 500 K yielding very high carrier mobility. It suggests that the scattering by dislocations (stacking faults) can be very detrimental for carrier mobility. (paper)

Fusion radioactivity confinement and application to postulated ITER accidents

International Nuclear Information System (INIS)

Piet, S.J.; Brereton, S.J.

1991-01-01

An assessment of the ITER radioactivity confinement shows reduction of potential accidental releases to the environment by two orders of magnitude. Important credits are the 1% volume/day confinement leakage rate, radioactivity decay for short-lived isotopes, resumption of detritiation/negative pressure within seven days of the accident, and wind meander during the slow confinement leakage. Achieving this two order of magnitude credit in practice requires appropriate design details, especially the leakage rate and detritiation/negative pressure equipment, and research to validate some key assumptions. The confinement maximizes dependence on passive safety features, thereby working toward using fusion's potential safety advantages. The confinement includes several confinement zones with varying human access allowances. Some confinement areas are normally isolated from the environment, the closed ventilation zone. Some areas have an inert cover gas to inhibit combustion. If future assessments of accidental overpressure show the need, we propose a filter/vent system. This report documents our work for the ITER Conceptual Design Activity (CDA). The report is consistent with the final CDA design reports and descriptions, except that our analysis includes a filter/vent. For gaseous or vapor tritium and for most activated aerosols, the reference release fraction is about 2%. For short-lived tungsten-rhenium aerosols, the reference release fraction is somewhat lower, as low as 0.5% for some accident scenarios. Even without resumption of detritiation/decontamination or negative pressure within seven days of the accident, the release fraction for stays below 4%

Bistability in a self-assembling system confined by elastic walls: Exact results in a one-dimensional lattice model

Energy Technology Data Exchange (ETDEWEB)

Pȩkalski, J.; Ciach, A. [Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warszawa (Poland); Almarza, N. G. [Instituto de Química Física Rocasolano, CSIC, Serrano 119, E-28006 Madrid (Spain)

2015-01-07

The impact of confinement on self-assembly of particles interacting with short-range attraction and long-range repulsion potential is studied for thermodynamic states corresponding to local ordering of clusters or layers in the bulk. Exact and asymptotic expressions for the local density and for the effective potential between the confining surfaces are obtained for a one-dimensional lattice model introduced by J. Pȩkalski et al. [J. Chem. Phys. 138, 144903 (2013)]. The simple asymptotic formulas are shown to be in good quantitative agreement with exact results for slits containing at least 5 layers. We observe that the incommensurability of the system size and the average distance between the clusters or layers in the bulk leads to structural deformations that are different for different values of the chemical potential μ. The change of the type of defects is reflected in the dependence of density on μ that has a shape characteristic for phase transitions. Our results may help to avoid misinterpretation of the change of the type of defects as a phase transition in simulations of inhomogeneous systems. Finally, we show that a system confined by soft elastic walls may exhibit bistability such that two system sizes that differ approximately by the average distance between the clusters or layers are almost equally probable. This may happen when the equilibrium separation between the soft boundaries of an empty slit corresponds to the largest stress in the confined self-assembling system.

Loss of protection with insecticide-treated nets against pyrethroid-resistant Culex quinquefasciatus mosquitoes once nets become holed: an experimental hut study

Directory of Open Access Journals (Sweden)

Irish SR

2008-06-01

Full Text Available Abstract Background An important advantage of pyrethroid-treated nets over untreated nets is that once nets become worn or holed a pyrethroid treatment will normally restore protection. The capacity of pyrethroids to kill or irritate any mosquito that comes into contact with the net and prevent penetration of holes or feeding through the sides are the main reasons why treated nets continue to provide protection despite their condition deteriorating over time. Pyrethroid resistance is a growing problem among Anopheline and Culicine mosquitoes in many parts of Africa. When mosquitoes become resistant the capacity of treated nets to provide protection might be diminished, particularly when holed. An experimental hut trial against pyrethroid-resistant Culex quinquefasciatus was therefore undertaken in southern Benin using a series of intact and holed nets, both untreated and treated, to assess any loss of protection as nets deteriorate with use and time. Results There was loss of protection when untreated nets became holed; the proportion of mosquitoes blood feeding increased from 36.2% when nets were intact to between 59.7% and 68.5% when nets were holed to differing extents. The proportion of mosquitoes blood feeding when treated nets were intact was 29.4% which increased to 43.6–57.4% when nets were holed. The greater the number of holes the greater the loss of protection regardless of whether nets were untreated or treated. Mosquito mortality in huts with untreated nets was 12.9–13.6%; treatment induced mortality was less than 12%. The exiting rate of mosquitoes into the verandas was higher in huts with intact nets. Conclusion As nets deteriorate with use and become increasingly holed the capacity of pyrethroid treatments to restore protection is greatly diminished against resistant Culex quinquefasciatus mosquitoes.

Traditional nets interfere with the uptake of long-lasting insecticidal nets in the Peruvian Amazon: the relevance of net preference for achieving high coverage and use.

Directory of Open Access Journals (Sweden)

Koen Peeters Grietens

Full Text Available While coverage of long-lasting insecticide-treated nets (LLIN has steadily increased, a growing number of studies report gaps between net ownership and use. We conducted a mixed-methods social science study assessing the importance of net preference and use after Olyset® LLINs were distributed through a mass campaign in rural communities surrounding Iquitos, the capital city of the Amazonian region of Peru.The study was conducted in the catchment area of the Paujil and Cahuide Health Centres (San Juan district between July 2007 and November 2008. During a first qualitative phase, participant observation and in-depth interviews collected information on key determinants for net preference and use. In a second quantitative phase, a survey among recently confirmed malaria patients evaluated the acceptability and use of both LLINs and traditional nets, and a case control study assessed the association between net preference/use and housing structure (open vs. closed houses.A total of 10 communities were selected for the anthropological fieldwork and 228 households participated in the quantitative studies. In the study area, bed nets are considered part of the housing structure and are therefore required to fulfil specific architectural and social functions, such as providing privacy and shelter, which the newly distributed Olyset® LLINs ultimately did not. The LLINs' failure to meet these criteria could mainly be attributed to their large mesh size, transparency and perceived ineffectiveness to protect against mosquitoes and other insects, resulting in 63.3% of households not using any of the distributed LLINs. Notably, LLIN usage was significantly lower in houses with no interior or exterior walls (35.2% than in those with walls (73.8% (OR = 5.2, 95CI [2.2; 12.3], p<0.001.Net preference can interfere with optimal LLIN use. In order to improve the number of effective days of LLIN protection per dollar spent, appropriate quantitative and qualitative

Electrostatic-Dipole (ED) Fusion Confinement Studies

Science.gov (United States)

Miley, George H.; Shrestha, Prajakti J.; Yang, Yang; Thomas, Robert

2004-11-01

The Electrostatic-Dipole (ED) concept significantly differs from a "pure" dipole confinement device [1] in that the charged particles are preferentially confined to the high-pressure region interior of the dipole coil by the assistance of a surrounding spherical electrostatic grid. In present ED experiments, a current carrying coil is embedded inside the grid of an IEC such as to produce a magnetic dipole field. Charged particles are injected axisymmetrically from an ion gun (or duo-plasmatron) into the center of the ED confinement grid/dipole ring where they oscillate along the magnetic field lines and pass the peak field region at the center of the dipole region. As particles begin accelerating away from the center region towards the outer electrostatic grid region, they encounter a strong electrostatic potential (order of 10's of kilovolts) retarding force. The particles then decelerate, reverse direction and re-enter the dipole field region where again magnetic confinement dominates. This process continues, emulating a complex harmonic oscillator motion. The resulting pressure profile averaged over the field curvature offers good plasma stability in the ED configuration. The basic concept and results from preliminary experiments will be described. [1] M.E. Mauel, et al. "Dipole Equilibrium and Stability," 18th IAEA Conference of Plasma Phys. and Control. Nuclear Fusion, Varenna, Italy 2000, IAEA-F1-CN-70/TH

HANPP Collection: Human Appropriation of Net Primary Productivity as a Percentage of Net Primary Productivity

Data.gov (United States)

National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) as a Percentage of Net Primary Product (NPP) portion of the HANPP Collection represents a map identifying...

A plastic damage model with stress triaxiality-dependent hardening

International Nuclear Information System (INIS)

Shen Xinpu; Shen Guoxiao; Zhou Lin

2005-01-01

Emphases of this study were placed on the modelling of plastic damage behaviour of prestressed structural concrete, with special attention being paid to the stress-triaxiality dependent plastic hardening law and the corresponding damage evolution law. A definition of stress triaxiality was proposed and introduced in the model presented here. Drucker-Prager -type plasticity was adopted in the formulation of the plastic damage constitutive equations. Numerical validations were performed for the proposed plasticity-based damage model with a driver subroutine developed in this study. The predicted stress-strain behaviour seems reasonably accurate for the uniaxial tension and uniaxial compression compared with the experimental data reported in references. Numerical calculations of compressions under various hydrostatic stress confinements were carried out in order to validate the stress triaxiality dependent properties of the model. (authors)

Experimental Study of Damage Evolution in Circular Stirrup-Confined Concrete.

Science.gov (United States)

Li, Zuohua; Peng, Zhihan; Teng, Jun; Wang, Ying

2016-04-08

This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the stirrup confinement. Firstly, the concrete damage evolution can be relatively restrained with the increase of the stirrup volume ratio. Secondly, higher stirrup yield strength usually causes larger confining pressures and slower concrete damage evolution. In contrast, higher concrete strength leads to higher brittleness, which accelerates the concrete damage evolution. A plastic strain expression is obtained through curve fitting, and a damage evolution equation for circular stirrup-confined concrete is proposed by introducing a confinement factor ( C ) based on the experimental data. The comparison results demonstrate that the proposed damage evolution model can accurately describe the experimental results.

Experimental Study of Damage Evolution in Circular Stirrup-Confined Concrete

Science.gov (United States)

Li, Zuohua; Peng, Zhihan; Teng, Jun; Wang, Ying

2016-01-01

This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the stirrup confinement. Firstly, the concrete damage evolution can be relatively restrained with the increase of the stirrup volume ratio. Secondly, higher stirrup yield strength usually causes larger confining pressures and slower concrete damage evolution. In contrast, higher concrete strength leads to higher brittleness, which accelerates the concrete damage evolution. A plastic strain expression is obtained through curve fitting, and a damage evolution equation for circular stirrup-confined concrete is proposed by introducing a confinement factor (C) based on the experimental data. The comparison results demonstrate that the proposed damage evolution model can accurately describe the experimental results. PMID:28773402

Delta Semantics Defined By Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

Issues in tokamak/stellarator transport and confinement enhancement mechanisms

International Nuclear Information System (INIS)

Perkins, F.W.

1990-08-01

At present, the mechanism for anomalous energy transport in low-β toroidal plasmas -- tokamaks and stellarators -- remains unclear, although transport by turbulent E x B velocities associated with nonlinear, fine-scale microinstabilities is a leading candidate. This article discusses basic theoretical concepts of various transport and confinement enhancement mechanisms as well as experimental ramifications which would enable one to distinguish among them and hence identify a dominant transport mechanism. While many of the predictions of fine-scale turbulence are born out by experiment, notable contradictions exist. Projections of ignition margin rest both on the scaling properties of the confinement mechanism and on the criteria for entering enhanced confinement regimes. At present, the greatest uncertainties lie with the basis for scaling confinement enhancement criteria. A series of questions, to be answered by new experimental/theoretical work, is posed to resolve these outstanding contradictions (or refute the fine-scale turbulence model) and to establish confinement enhancement criteria. 73 refs., 4 figs., 5 tabs

Large Eddy Simulation of the spray formation in confinements

International Nuclear Information System (INIS)

Lampa, A.; Fritsching, U.

2013-01-01

Highlights: • Process stability of confined spray processes is affected by the geometric design of the spray confinement. • LES simulations of confined spray flow have been performed successfully. • Clustering processes of droplets is predicted in simulations and validated with experiments. • Criteria for specific coherent gas flow patterns and droplet clustering behaviour are found. -- Abstract: The particle and powder properties produced within spray drying processes are influenced by various unsteady transport phenomena in the dispersed multiphase spray flow in a confined spray chamber. In this context differently scaled spray structures in a confined spray environment have been analyzed in experiments and numerical simulations. The experimental investigations have been carried out with Particle-Image-Velocimetry to determine the velocity of the gas and the discrete phase. Large-Eddy-Simulations have been set up to predict the transient behaviour of the spray process and have given more insight into the sensitivity of the spray flow structures in dependency from the spray chamber design

Some aspects of geometrical confinement

Energy Technology Data Exchange (ETDEWEB)

Novello, M.; De Lorenci, V.A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Elbaz, E. [Lyon-1 Univ., 69 - Villeurbanne (France)

1998-04-01

In this paper we present a toy model for the dynamics of a gauge field theory in such way that spin-one particles can be confined in a compact domain. We show that the property of confinement can be associated to the formation of a null surface identified to a horizon. This is due to the presence of an effective geometry generated by the self-interaction of the gauge field that guides the wave propagation of the field. This phenomenon has a striking analogy to the gravitational black hole in Einstein general theory of relativity, separating two domains of spacetime that can be trespassed only into one direction. (author) 4 refs.

Unconfined versus confined speleogenetic settings: variations of solution porosity.

Directory of Open Access Journals (Sweden)

Klimchouk Alexander

2006-01-01

Full Text Available Speleogenesis in confined settings generates cave morphologies that differ much from those formed in unconfined settings. Cavesdeveloped in unconfined settings are characterised by broadly dendritic patterns of channels due to highly competing development.In contrast, caves originated under confined conditions tend to form two- or three-dimensional mazes with densely packed conduits.This paper illustrates variations of solution (channel porosity resulted from speleogenesis in unconfined and confined settings by theanalysis of morphometric parameters of typical cave patterns. Two samples of typical cave systems formed in the respective settingsare compared. The sample that represents unconfined speleogenesis consists of solely limestone caves, whereas gypsum cavesof this type tend to be less dendritic and more linear. The sample that represents confined speleogenesis consists of both limestoneand gypsum maze caves. The comparison shows considerable differences in average values of some parameters between thesettings. Passage network density (the ratio of the cave length to the area of the cave field, km/km2 is one order of magnitudegreater in confined settings than in unconfined (average 167.3 km/km2 versus 16.6 km/km2. Similarly, an order of magnitudedifference is observed in cave porosity (a fraction of the volume of a cave block, occupied by mapped cavities; 5.0 % versus 0.4 %.This illustrates that storage in maturely karstified confined aquifers is generally much greater than in unconfined. The average areal coverage (a fraction of the area of the cave field occupied by passages in a plan view is about 5 times greater in confined settingsthan in unconfined (29.7 % versus 6.4 %. This indicates that conduit permeability in confined aquifers is appreciably easier to targetwith drilling than the widely spaced conduits in unconfined aquifers.

Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees

Energy Technology Data Exchange (ETDEWEB)

Leon, V

2006-07-15

Physico-chemical properties of materials can be strongly modified by confinement because of the quantum effects that appear at such small length scales and also because of the effects of the confinement itself. The aim of this thesis is to show that both the nature of the confining material and the size of the pores and cavities have a strong impact on the confined material. We first show the effect of the pore size of the host meso-porous silica on the temperature of the solid-solid phase transition of silver selenide, a semiconducting material with enhanced magnetoresistive properties under non-stoichiometric conditions. Narrowing the pores from 20 nm to 2 nm raises the phase transition temperature from 139 C to 146 C. This result can be explained by considering the interaction between the confining and confined materials as a driving force. The effects of confinement are also studied in the case of hydrogen and deuterium inside cavities of organized carbon nano-structures. The effects that appear in the adsorption/desorption cycles are much stronger with carbon nano-horns as the host material than with C60 pea-pods and single-walled carbon nano-tubes. (author)

Coloured Petri Nets and the Invariant Method

DEFF Research Database (Denmark)

Jensen, Kurt

1981-01-01

processes to be described by a common subnet, without losing the ability to distinguish between them. Our generalization, called coloured Petri nets, is heavily influenced by predicate transition-nets introduced by H.J. Genrich and K. Lautenbach. Moreover our paper shows how the invariant-method, introduced...... for Petri nets by K. Lautenbach, can be generalized to coloured Petri nets....

Experimental Studies on Permeability of Intact and Singly Jointed Meta-Sedimentary Rocks Under Confining Pressure

Science.gov (United States)

Wong, Louis Ngai Yuen; Li, Diyuan; Liu, Gang

2013-01-01

Three different types of permeability tests were conducted on 23 intact and singly jointed rock specimens, which were cored from rock blocks collected from a rock cavern under construction in Singapore. The studied rock types belong to inter-bedded meta-sandstone and meta-siltstone with very low porosity and high uniaxial compressive strength. The transient pulse water flow method was employed to measure the permeability of intact meta-sandstone under a confining pressure up to 30 MPa. It showed that the magnitude order of meta-sandstone's intrinsic permeability is about 10-18 m2. The steady-state gas flow method was used to measure the permeability of both intact meta-siltstone and meta-sandstone in a triaxial cell under different confining pressures spanning from 2.5 to 10 MPa. The measured permeability of both rock types ranged from 10-21 to 10-20 m2. The influence of a single natural joint on the permeability of both rock types was studied by using the steady-state water flow method under different confining pressures spanning from 1.25 to 5.0 MPa, including loading and unloading phases. The measured permeability of both jointed rocks ranged from 10-13 to 10-11 m2, where the permeability of jointed meta-siltstone was usually slightly lower than that of jointed meta-sandstone. The permeability of jointed rocks decreases with increasing confining pressure, which can be well fitted by an empirical power law relationship between the permeability and confining pressure or effective pressure. The permeability of partly open cracked specimens is lower than that of open cracked specimens, but it is higher than that of the specimen with a dominant vein for the meta-sandstone under the same confining pressure. The permeability of open cracked rock specimens will partially recover during the unloading confining pressure process. The equivalent crack (joint) aperture is as narrow as a magnitude order of 10-6 m (1 μm) in the rock specimens under confining pressures

A response analysis with effective stress model by using vertical input motions

International Nuclear Information System (INIS)

Yamanouchi, H.; Ohkawa, I.; Chiba, O.; Tohdo, M.; Kaneko, O.

1987-01-01

The nuclear power plant reactor buildings are to be directly supported on a hard soil as a rule in Japan. In case of determining the input motions in order to design those buildings, the amplifications of the hard soil deposits are examined by the total stress analysis in general. However, when the supporting hard soil is replaced with the slightly softer medium such as sandy or gravelly soil, the existence of pore water, in other words, the contribution of the pore water pressure to the total stress cannot be ignored even in a practical sense. In this paper the authors defined an analytical model considering the effective stress-strain relation. In the analyses, the response in the vertical direction is used to evaluate the confining pressure, at first. In the next step, the process of the generation and dissipation of the pore water pressure, is taken into account, together with the effect of the confining pressure. They applied these procedures for the response computations of the horizontally layered soil deposits

Net metering in British Columbia : white paper

International Nuclear Information System (INIS)

Berry, T.

2003-01-01

Net metering was described as being the reverse registration of an electricity customer's revenue meter when interconnected with a utility's grid. It is a provincial policy designed to encourage small-distributed renewable power generation such as micro-hydro, solar energy, fuel cells, and larger-scale wind energy. It was noted that interconnection standards for small generation is an important issue that must be addressed. The British Columbia Utilities Commission has asked BC Hydro to prepare a report on the merits of net metering in order to support consultations on a potential net metering tariff application by the utility. This report provides information on net metering with reference to experience in other jurisdictions with net metering, and the possible costs and benefits associated with net metering from both a utility and consumer perspective. Some of the barriers and policy considerations for successful implementation of net metering were also discussed. refs., tabs., figs

Quark confinement potential and color Van der Waals force

International Nuclear Information System (INIS)

Zheng Yuming; Hua Daping; Liu Zuhua

1985-01-01

The color-analog Van der Waals force between two hadrons is studied by use of the coupling channel resonating group method in the framework of the Gaussian-type quark confinement potential. The problem of the boundary values for the two channel coupling differential equations is changed to the problem of the initial values. The equations are solved numerically by use of the Gear mehtod. The calculated results show that there is no color Van der Waals force between hadrons in the confinement potential model. This indicates that the confinement potential model not only can describe the internal structure of hadrons but also can be used to calculate the hadron-hadron interactions if the quark confinement potential is chosen properly

Biological Petri Nets

CERN Document Server

Wingender, E

2011-01-01

It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

Comparative study on the mechanical mechanism of confined concrete supporting arches in underground engineering.

Science.gov (United States)

Lv, Zhijin; Qin, Qian; Jiang, Bei; Luan, Yingcheng; Yu, Hengchang

2018-01-01

In order to solve the supporting problem in underground engineering with high stress, square steel confined concrete (SQCC) supporting method is adopted to enhance the control on surrounding rocks, and the control effect is remarkable. The commonly used cross section shapes of confined concrete arch are square and circular. At present, designers have no consensus on which kind is more proper. To search for the answer, this paper makes an analysis on the mechanical properties of the two shapes of the cross-sections. A full-scale indoor comparative test was carried out on the commonly used straight-wall semi-circular SQCC arch and circular steel confined concrete arch (CCC arch). This test is based on self-developed full-scale test system for confined concrete arch. Our research, combining with the numerical analysis, shows: (1) SQCC arch is consistent with CCC arch in the deformation and failure mode. The largest damages parts are at the legs of both of them. (2) The SQCC arch's bearing capability is 1286.9 kN, and the CCC arch's ultimate bearing capability is 1072.4kN. Thus, the SQCC arch's bearing capability is 1.2 times that of the CCC arch. (3) The arches are subjected to combined compression and bending, bending moment is the main reason for the arch failure. The section moment of inertia of SQCC arch is 1.26 times of that of CCC arch, and the former is better than the latter in bending performance. The ultimate bearing capacity is positively correlated with the size of the moment of inertia. Based on the above research, the engineering suggestions are as follows: (1) To improve the bearing capacity of the arch, the cross-sectional shape of the chamber should be optimized and the arch bearing mode changed accordingly. (2) The key damaged positions, such as the arch leg, should be reinforced, optimizing the state of force on the arch. SQCC arches should be used for supporting in underground engineering, which is under stronger influence of the bending moment and

An experiment to test centrifugal confinement for fusion

International Nuclear Information System (INIS)

Ellis, R.F.; Hassam, A.B.; Messer, S.; Osborn, B.R.

2001-01-01

The basic idea of centrifugal confinement is to use centrifugal forces from supersonic rotation to augment conventional magnetic confinement. Optimizing this 'knob' results in a fusion device that features four advantages: steady state, no disruptions, superior cross-field confinement, and a simpler coil configuration. The idea rests on two prongs: first, centrifugal forces can confine plasmas to desired regions of shaped magnetic fields; second, the accompanying large velocity shear can stabilize even magnetohydrodynamic (MHD) instabilities. A third feature is that the velocity shear also viscously heats the plasma; no auxiliary heating is necessary to reach fusion temperatures. Regarding transport, the velocity shear can also quell microturbulence, leading to fully classical confinement, as there are no neoclassical effects. Classical parallel electron transport then sets the confinement time. These losses are minimized by a large Pastukhov factor resulting from the deep centrifugal potential well: at Mach 4-5, the Lawson criterion is accessible. One key issue is whether velocity shear will be sufficient by itself to stabilize MHD interchanges. Numerical simulations indicate that laminar equilibria can be obtained at Mach numbers of 4-5 but that the progression toward laminarity with increasing Mach number is accompanied by residual convection from the interchanges. The central goal of the Maryland Centrifugal Torus (MCT) [R. F. Ellis et al., Bull. Am. Phys. Soc. 44, 48 (1998)] is to obtain MHD stability from velocity shear. As an assist to accessing laminarity, MCT will incorporate two unique features: plasma elongation and toroidal magnetic field. The former raises velocity shear efficiency, and modest magnetic shear should suppress residual convection

Confinement Effect on Material Properties of RC Beams Under Flexure

Science.gov (United States)

Kulkarni, Sumant; Shiyekar, Mukund Ramchandra; Shiyekar, Sandip Mukund

2017-12-01

In structural analysis, especially in indeterminate structures, it becomes essential to know the material and geometrical properties of members. The codal provisions recommend elastic properties of concrete and steel and these are fairly accurate enough. The stress-strain curve for concrete cylinder or a cube specimen is plotted. The slope of this curve is modulus of elasticity of plain concrete. Another method of determining modulus of elasticity of concrete is by flexural test of a beam specimen. The modulus of elasticity most commonly used for concrete is secant modulus. The modulus of elasticity of steel is obtained by performing a tension test of steel bar. While performing analysis by any software for high rise building, cross area of plain concrete is taken into consideration whereas effects of reinforcement bars and concrete confined by stirrups are neglected. Present aim of study is to determine elastic properties of reinforced cement concrete beam. Two important stiffness properties such as AE and EI play important role in analysis of high rise RCC building idealized as plane frame. The experimental program consists of testing of beams (model size 150 × 150 × 700 mm) with percentage of reinforcement varying from 0.54 to 1.63% which commensurate with existing Codal provisions of IS:456-2000 for flexural member. The effect of confinement is considered in this study. The experimental results are verified by using 3D finite element techniques.

Influence of error fields on the plasma confining field and the plasma confinement in tokamak

International Nuclear Information System (INIS)

Matsuda, Shinzaburo

1977-05-01

Influence of error fields on the plasma confining field and the plasma confinement is treated in the standpoint of design. In the initial breakdown phase before formation of the closed magnetic surfaces, the vertical field properly applied is the most important. Once the magnetic surfaces are formed, the non-axisymmetric error field is important. Effect of the shell gap associated with iron core and with pulsed vertical coils is thus studied. The formation of magnetic islands due to the external non-axisymmetric error field is studied with a simple model. A method of suppressing the islands by choosing the minor periodicity is proposed. (auth.)

Modelling of current loads on aquaculture net cages

Science.gov (United States)

Kristiansen, Trygve; Faltinsen, Odd M.

2012-10-01

In this paper we propose and discuss a screen type of force model for the viscous hydrodynamic load on nets. The screen model assumes that the net is divided into a number of flat net panels, or screens. It may thus be applied to any kind of net geometry. In this paper we focus on circular net cages for fish farms. The net structure itself is modelled by an existing truss model. The net shape is solved for in a time-stepping procedure that involves solving a linear system of equations for the unknown tensions at each time step. We present comparisons to experiments with circular net cages in steady current, and discuss the sensitivity of the numerical results to a set of chosen parameters. Satisfactory agreement between experimental and numerical prediction of drag and lift as function of the solidity ratio of the net and the current velocity is documented.

Confinement and Tritium Stripping Systems for APT Tritium Processing

Energy Technology Data Exchange (ETDEWEB)

Hsu, R.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Heung, L.K.

1997-10-20

This report identifies functions and requirements for the tritium process confinement and clean-up system (PCCS) and provides supporting technical information for the selection and design of tritium confinement, clean-up (stripping) and recovery technologies for new tritium processing facilities in the Accelerator for the Production of Tritium (APT). The results of a survey of tritium confinement and clean-up systems for large-scale tritium handling facilities and recommendations for the APT are also presented.

Confinement and Tritium Stripping Systems for APT Tritium Processing

International Nuclear Information System (INIS)

Hsu, R.H.; Heung, L.K.

1997-01-01

This report identifies functions and requirements for the tritium process confinement and clean-up system (PCCS) and provides supporting technical information for the selection and design of tritium confinement, clean-up (stripping) and recovery technologies for new tritium processing facilities in the Accelerator for the Production of Tritium (APT). The results of a survey of tritium confinement and clean-up systems for large-scale tritium handling facilities and recommendations for the APT are also presented

Mesoscale simulations of confined Nafion thin films

Science.gov (United States)

Vanya, P.; Sharman, J.; Elliott, J. A.

2017-12-01

The morphology and transport properties of thin films of the ionomer Nafion, with thicknesses on the order of the bulk cluster size, have been investigated as a model system to explain the anomalous behaviour of catalyst/electrode-polymer interfaces in membrane electrode assemblies. We have employed dissipative particle dynamics (DPD) to investigate the interaction of water and fluorocarbon chains, with carbon and quartz as confining materials, for a wide range of operational water contents and film thicknesses. We found confinement-induced clustering of water perpendicular to the thin film. Hydrophobic carbon forms a water depletion zone near the film interface, whereas hydrophilic quartz results in a zone with excess water. There are, on average, oscillating water-rich and fluorocarbon-rich regions, in agreement with experimental results from neutron reflectometry. Water diffusivity shows increasing directional anisotropy of up to 30% with decreasing film thickness, depending on the hydrophilicity of the confining material. A percolation analysis revealed significant differences in water clustering and connectivity with the confining material. These findings indicate the fundamentally different nature of ionomer thin films, compared to membranes, and suggest explanations for increased ionic resistances observed in the catalyst layer.

Cluster Analysis of the International Stellarator Confinement Database

International Nuclear Information System (INIS)

Kus, A.; Dinklage, A.; Preuss, R.; Ascasibar, E.; Harris, J. H.; Okamura, S.; Yamada, H.; Sano, F.; Stroth, U.; Talmadge, J.

2008-01-01

Heterogeneous structure of collected data is one of the problems that occur during derivation of scalings for energy confinement time, and whose analysis tourns out to be wide and complicated matter. The International Stellarator Confinement Database [1], shortly ISCDB, comprises in its latest version 21 a total of 3647 observations from 8 experimental devices, 2067 therefrom beeing so far completed for upcoming analyses. For confinement scaling studies 1933 observation were chosen as the standard dataset. Here we describe a statistical method of cluster analysis for identification of possible cohesive substructures in ISDCB and present some preliminary results

PhysioNet

Data.gov (United States)

U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

Pro Agile NET Development with Scrum

CERN Document Server

Blankenship, Jerrel; Millett, Scott

2011-01-01

Pro Agile .NET Development with SCRUM guides you through a real-world ASP.NET project and shows how agile methodology is put into practice. There is plenty of literature on the theory behind agile methodologies, but no book on the market takes the concepts of agile practices and applies these in a practical manner to an end-to-end ASP.NET project, especially the estimating, requirements and management aspects of a project. Pro Agile .NET Development with SCRUM takes you through the initial stages of a project - gathering requirements and setting up an environment - through to the development a

High efficiency confinement mode by electron cyclotron heating

International Nuclear Information System (INIS)

Funahashi, Akimasa

1987-01-01

In the medium size nuclear fusion experiment facility JFT-2M in the Japan Atomic Energy Research Institute, the research on the high efficiency plasma confinement mode has been advanced, and in the experiment in June, 1987, the formation of a high efficiency confinement mode was successfully controlled by electron cyclotron heating, for the first time in the world. This result further advanced the control of the formation of a high efficiency plasma confinement mode and the elucidation of the physical mechanism of that mode, and promoted the research and development of the plasma heating by electron cyclotron heating. In this paper, the recent results of the research on a high efficiency confinement mode at the JFT-2M are reported, and the role of the JFT-2M and the experiment on the improvement of core plasma performance are outlined. Now the plasma temperature exceeding 100 million deg C has been attained in large tokamaks, and in medium size facilities, the various measures for improving confinement performance are to be brought forth and their scientific basis is elucidated to assist large facilities. The JFT-2M started the operation in April, 1983, and has accumulated the results smoothly since then. (Kako, I.)

Surface-Activated Coupling Reactions Confined on a Surface.

Science.gov (United States)

Dong, Lei; Liu, Pei Nian; Lin, Nian

2015-10-20

Chemical reactions may take place in a pure phase of gas or liquid or at the interface of two phases (gas-solid or liquid-solid). Recently, the emerging field of "surface-confined coupling reactions" has attracted intensive attention. In this process, reactants, intermediates, and products of a coupling reaction are adsorbed on a solid-vacuum or a solid-liquid interface. The solid surface restricts all reaction steps on the interface, in other words, the reaction takes place within a lower-dimensional, for example, two-dimensional, space. Surface atoms that are fixed in the surface and adatoms that move on the surface often activate the surface-confined coupling reactions. The synergy of surface morphology and activity allow some reactions that are inefficient or prohibited in the gas or liquid phase to proceed efficiently when the reactions are confined on a surface. Over the past decade, dozens of well-known "textbook" coupling reactions have been shown to proceed as surface-confined coupling reactions. In most cases, the surface-confined coupling reactions were discovered by trial and error, and the reaction pathways are largely unknown. It is thus highly desirable to unravel the mechanisms, mechanisms of surface activation in particular, of the surface-confined coupling reactions. Because the reactions take place on surfaces, advanced surface science techniques can be applied to study the surface-confined coupling reactions. Among them, scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) are the two most extensively used experimental tools. The former resolves submolecular structures of individual reactants, intermediates, and products in real space, while the latter monitors the chemical states during the reactions in real time. Combination of the two methods provides unprecedented spatial and temporal information on the reaction pathways. The experimental findings are complemented by theoretical modeling. In particular, density

KONVERGENSI DALAM PROGRAM NET CITIZEN JOURNALISM

Directory of Open Access Journals (Sweden)

Rhafidilla Vebrynda

2017-06-01

Full Text Available Di dalam artikel ini, peneliti ingin melihat perkembangan teknologi di Indonesia sebagai sebuah peluang untuk menjalankan sebuah program berita berbasis video kiriman masyarakat. Perkembangan teknologi tersebut adalah teknologi penyiaran, teknologi sosial media dan teknologi dalam proses produksi sebuah video. Di Indonesia, jumlah televisi semakin banyak. Setiap stasiun televisi harus bersaing untuk dapat bertahan hidup. Net TV merupakan sebuah stasiun televisi baru di Indonesia yang harus memiliki berbagai program unggulan baru agar dapat bersaing dengan televisi lainnya yang sudah ada. Net TV menggunakan berbagai platform media untuk menjalankan program Net Citizen Journalism (Net CJ. Penggunaan berbagai platform media dikenal dengan istilah multiplatform dan secara teoritis dikenal dengan istilah konvergensi. Konvergensi yaitu saat meleburnya domain-domain dalam berbagai media komunikasi. Artikel ini menggunakan metode studi kasus untuk melihat bagaimana konvergensi terjadi dalam proses pengelolaan program Net CJ. Teknik pengumpulan data adalah dengan wawancara mendalam, observasi dan studi dokumen. Wawancara mendalam dilakukan dari tiga sudut pandang yaitu dari pengelola program, pengguna/audience dan pengamat media. Penelitian ini menemukan bahwa dengan menggunakan berbagai platform media yang fungsinya berbeda, memiliki satu tujuan yang sama yaitu untuk menjalankan program Net CJ. Adapun berbagai platform dalam proses produksi program yaitu tayangan TV konvensional, streaming TV, website, aplikasi Net CJ, facebook, twitter, instagram dan path. Konvergensi media dijalankan dalam dua proses, yaitu proses produksi dan proses promosi program berita.

Waste-acceptance criteria for greater confinement disposal

International Nuclear Information System (INIS)

Gilbert, T.L.; Meshkov, N.K.

1987-01-01

A methodology for establishing waste-acceptance criteria based on quantitative performance factors that characterize the confinement capabilities of a waste disposal site and facility has been developed. The methodology starts from the basic objective of protecting public health and safety by providing assurance that disposal of the waste will not result in a radiation dose to any member of the general public, in either the short or long term, in excess of an established basic dose limit. The method is based on an explicit, straight-forward, and quantitative relationship among individual risk, confinement capabilities, and waste characteristics. A key aspect of the methodology is introduction of a confinement factor that characterizes the overall confinement capability of a particular facility and can be used for quantitative assessments of the performance of different disposal sites and facilities, as well as for establishing site-specific waste acceptance criteria. Confinement factors are derived by means of site-specific pathway analyses. They make possible a direct and simple conversion of a basic dose limit into waste-acceptance criteria, specified as concentration limits on radionuclides in the waste streams and expressed in quantitative form as a function of parameters that characterize the site, facility design, waste containers, and waste form. Waste acceptance criteria can be represented visually as activity/time plots for various waste streams. These plots show the concentrations of radionuclides in a waste stream as a function of time and permit a visual, quantitative assessment of long-term performance, relative risks from different radionuclides in the waste stream, and contributions from ingrowth. 13 references, 7 figures

Waste-acceptance criteria for greater-confinement disposal

International Nuclear Information System (INIS)

Gilbert, T.L.; Meshkov, N.K.

1986-01-01

A methodology for establishing waste-acceptance criteria based on quantitative performance factors that characterize the confinement capabilities of a waste-disposal site and facility has been developed. The methodology starts from the basic objective of protecting public health and safety by providing assurance that dispsoal of the waste will not result in a radiation dose to any member of the general public, in either the short or long term, in excess of an established basic dose limit. The method is based on an explicit, straightforward, and quantitative relationship among individual risk, confinement capabilities, and waste characteristics. A key aspect of the methodology is the introduction of a confinement factor that characterizes the overall confinement capability of a particular facility and can be used for quantitative assessments of the performance of different disposal sites and facilities, as well as for establishing site-specific waste-acceptance criteria. Confinement factors are derived by means of site-specific pathway analyses. They make possible a direct and simple conversion of a basic dose limit into waste-acceptance criteria, specified as concentration limits on radionuclides in the waste streams and expressed in quantitative form as a function of parameters that characterize the site, facility design, waste containers, and waste form. Waste-acceptance criteria can be represented visually as activity/time plots for various waste streams. These plots show the concentrations of radionuclides in a waste stream as a function of time and permit a visual, quantitative assessment of long-term performance, relative risks from different radionuclides in the waste stream, and contributions from ingrowth. 13 refs

Isotope effect on confinement in DT plasmas

International Nuclear Information System (INIS)

Fukuyama, A.; Itoh, K.; Itoh, S.; Yagi, M.; Azumi, M.

1994-03-01

Isotope effect on the energy confinement time is discussed for the DT plasma. The transport theory which is based on the ballooning mode turbulence is applied. When the DT plasma is produced under the condition of β p >1, the energy confinement time of DT plasma (50% mixture) is expected to be about 1.2 times better than the D plasma with the same operation condition. (author)

Which family members use the best nets? An analysis of the condition of mosquito nets and their distribution within households in Tanzania

Directory of Open Access Journals (Sweden)

Lines Jo

2010-07-01

Full Text Available Abstract Background Household ownership of insecticide-treated mosquito nets (ITNs is increasing, and coverage targets have been revised to address universal coverage with ITNs. However, many households do not have enough nets to cover everyone, and the nets available vary in physical condition and insecticide treatment status. Since 2004, the Government of Tanzania has been implementing the Tanzania National Voucher Scheme (TNVS, which distributes vouchers for ITNs through antenatal clinics to target pregnant women and their infants. This analysis aimed to determine the following: (1 coverage patterns of bed nets within households according to physical condition and treatment status; (2 who might be at risk if mosquitoes were diverted from occupants of untreated nets to those not using nets? (3 the degree to which those at highest risk of malaria use the most protective nets. Methods Data from the 2006 TNVS household survey were analysed to assess within-household distribution of net use. The associations between net characteristics and net user were also evaluated. Multivariate analysis was applied to the relationship between the number of holes per net and user characteristics while adjusting for confounders. Results In households with a net:person ratio better than 1:4 (one net for every four household members, more than 80% of the people in such households reported using a net the previous night. ITNs were most likely to be used by infants, young children (1-4 y, and women of childbearing age; they were least likely to be used by older women (≥50 y, older children (5-14 y, and adult men. The nets used by infants and women of childbearing age were in better-than-average physical condition; the nets used by older women and older children were in worse-than-average condition; while young children and adult men used nets in intermediate (average condition. When adjusted for confounders, the nets used by young and older children had more holes

MMPM - Mars MetNet Precursor Mission

Science.gov (United States)

Harri, A.-M.; Schmidt, W.; Pichkhadze, K.; Linkin, V.; Vazquez, L.; Uspensky, M.; Polkko, J.; Genzer, M.; Lipatov, A.; Guerrero, H.; Alexashkin, S.; Haukka, H.; Savijarvi, H.; Kauhanen, J.

2008-09-01

We are developing a new kind of planetary exploration mission for Mars - MetNet in situ observation network based on a new semi-hard landing vehicle called the Met-Net Lander (MNL). The eventual scope of the MetNet Mission is to deploy some 20 MNLs on the Martian surface using inflatable descent system structures, which will be supported by observations from the orbit around Mars. Currently we are working on the MetNet Mars Precursor Mission (MMPM) to deploy one MetNet Lander to Mars in the 2009/2011 launch window as a technology and science demonstration mission. The MNL will have a versatile science payload focused on the atmospheric science of Mars. Detailed characterization of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatology cycles, require simultaneous in-situ measurements by a network of observation posts on the Martian surface. The scientific payload of the MetNet Mission encompasses separate instrument packages for the atmospheric entry and descent phase and for the surface operation phase. The MetNet mission concept and key probe technologies have been developed and the critical subsystems have been qualified to meet the Martian environmental and functional conditions. Prototyping of the payload instrumentation with final dimensions was carried out in 2003-2006.This huge development effort has been fulfilled in collaboration between the Finnish Meteorological Institute (FMI), the Russian Lavoschkin Association (LA) and the Russian Space Research Institute (IKI) since August 2001. Currently the INTA (Instituto Nacional de Técnica Aeroespacial) from Spain is also participating in the MetNet payload development. To understand the behavior and dynamics of the Martian atmosphere, a wealth of simultaneous in situ observations are needed on varying types of Martian orography, terrain and altitude spanning all latitudes and longitudes. This will be performed by the Mars MetNet Mission. In addition to the science aspects the

The Definitive Guide to NetBeans Platform

CERN Document Server

Bock, Heiko

2009-01-01

The Definitive Guide to NetBeans(t) Platform is a thorough and definitive introduction to the NetBeans Platform, covering all its major APIs in detail, with relevant code examples used throughout. The original German book on which this title is based was well received. The NetBeans Platform Community has put together this English translation, which author Heiko Bock updated to cover the latest NetBeans Platform 6.5 APIs. With an introduction by known NetBeans Platform experts Jaroslav Tulach, Tim Boudreau, and Geertjan Wielenga, this is the most up-to-date book on this topic at the moment. All

Effects of free-range and confined housing on joint health in a herd of fattening pigs.

Science.gov (United States)

Etterlin, Pernille Engelsen; Ytrehus, Bjørnar; Lundeheim, Nils; Heldmer, Eva; Österberg, Julia; Ekman, Stina

2014-09-11

Free-range housing, in which pigs have access to both indoor and outdoor areas, is mandatory in organic pig production in Europe, but little is known about the effects of this housing on joint health in pigs. A high level of joint condemnations at slaughter has been reported in organic free-range pigs in Sweden, compared with pigs raised in conventional confined housing. We hypothesised that biomechanical forces imposed on the joints of pigs that range freely promote the development of osteochondrosis and lead to joint condemnation. We compared the prevalence of osteochondrosis and other joint lesions (e.g. arthritis, traumatic) in the elbow and hock joints of 91 crossbred Hampshire (Yorkshire × Landrace) fattening pigs that were housed in a free-range indoor/outdoor system with that in 45 pigs housed in confined indoor pens. A larger proportion of free-range than confined pigs had osteochondrosis in the elbow joints (69 vs. 50%, p free-range pigs showed moderate or severe lesions (33 vs. 16%, p free-range pigs also showed a higher prevalence of osteochondrosis in the hock joints (83 vs. 62%, p free-range pigs had condemned joints, all of which showed severe osteochondrosis, while no joints of confined pigs were condemned. In this experiment the prevalence of osteochondrosis in the elbow and the hock was higher, and lesions were more severe, in free-range than in confined pigs, suggesting that free-range housing increases the risk of acquiring osteochondrosis. Increased biomechanical stress to vulnerable joint structures may be the mechanism behind this effect, however more studies are needed to verify these results. This study suggests that modification of housing, and breeding for joints that are more adapted to free-range movement may be needed in free-range pig production. Severe osteochondrosis is a cause of joint condemnation, but the condemnation rate at slaughter underestimates the actual frequency of joint lesions and hence is a poor assessment of joint

Confinement of hydrogen at high pressure in carbon nanotubes

Science.gov (United States)

Lassila, David H [Aptos, CA; Bonner, Brian P [Livermore, CA

2011-12-13

A high pressure hydrogen confinement apparatus according to one embodiment includes carbon nanotubes capped at one or both ends thereof with a hydrogen-permeable membrane to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough. A hydrogen confinement apparatus according to another embodiment includes an array of multi-walled carbon nanotubes each having first and second ends, the second ends being capped with palladium (Pd) to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough as a function of palladium temperature, wherein the array of carbon nanotubes is capable of storing hydrogen gas at a pressure of at least 1 GPa for greater than 24 hours. Additional apparatuses and methods are also presented.

Confined-but-Connected Quantum Solids via Controlled Ligand Displacement

KAUST Repository

Baumgardner, William J.

2013-07-10

Confined-but-connected quantum dot solids (QDS) combine the advantages of tunable, quantum-confined energy levels with efficient charge transport through enhanced electronic interdot coupling. We report the fabrication of QDS by treating self-assembled films of colloidal PbSe quantum dots with polar nonsolvents. Treatment with dimethylformamide balances the rates of self-assembly and ligand displacement to yield confined-but-connected QDS structures with cubic ordering and quasi-epitaxial interdot connections through facets of neighboring dots. The QDS structure was analyzed by a combination of transmission electron microscopy and wide-angle and small-angle X-ray scattering. Excitonic absorption signatures in optical spectroscopy confirm that quantum confinement is preserved. Transport measurements show significantly enhanced conductivity in treated films. © 2013 American Chemical Society.

Static and Dynamic Properties of DNA Confined in Nanochannels

Science.gov (United States)

Gupta, Damini

Next-generation sequencing (NGS) techniques have considerably reduced the cost of high-throughput DNA sequencing. However, it is challenging to detect large-scale genomic variations by NGS due to short read lengths. Genome mapping can easily detect large-scale structural variations because it operates on extremely large intact molecules of DNA with adequate resolution. One of the promising methods of genome mapping is based on confining large DNA molecules inside a nanochannel whose cross-sectional dimensions are approximately 50 nm. Even though this genome mapping technology has been commercialized, the current understanding of the polymer physics of DNA in nanochannel confinement is based on theories and lacks much needed experimental support. The results of this dissertation are aimed at providing a detailed experimental understanding of equilibrium properties of nanochannel-confined DNA molecules. The results are divided into three parts. In first part, we evaluate the role of channel shape on thermodynamic properties of channel confined DNA molecules using a combination of fluorescence microscopy and simulations. Specifically, we show that high aspect ratio of rectangular channels significantly alters the chain statistics as compared to an equivalent square channel with same cross-sectional area. In the second part, we present experimental evidence that weak excluded volume effects arise in DNA nanochannel confinement, which form the physical basis for the extended de Gennes regime. We also show how confinement spectroscopy and simulations can be combined to reduce molecular weight dispersity effects arising from shearing, photo-cleavage, and nonuniform staining of DNA. Finally, the third part of the thesis concerns the dynamic properties of nanochannel confined DNA. We directly measure the center-of-mass diffusivity of single DNA molecules in confinement and show that that it is necessary to modify the classical results of de Gennes to account for local chain

Confinement studies of ohmically heated plasmas in TFTR

International Nuclear Information System (INIS)

Efthimion, P.C.; Bretz, N.L.; Bell, M.G.

1985-03-01

Systematic scans of density in large deuterium plasmas (a = 0.83 m) at several values of plasma current and toroidal magnetic field strength indicate that the total energy confinement time, tau/sub E/, is proportional to the line-average density anti n/sub e/ and the limiter q. Confinement times of approx. 0.3 s have been observed for anti n/sub e/ = 2.8 x 10 19 m -3 . Plasma size scaling experiments with plasmas of minor radii a = 0.83, 0.69, 0.55, and 0.41 m at constant limiter q reveal a confinement dependence on minor radius. The major-radius dependence of tau/sub E/, based on a comparison between TFTR and PLT results, is consistent with R 2 scaling. From the power balance, the thermal diffusivity chi/sub e/ is found to be significantly less than the INTOR value. In the a = 0.41 m plasmas, saturation of confinement is due to neoclassical ion conduction (chi/sub i/ neoclassical >> chi/sub e/)

Universal evaporation dynamics of a confined sessile droplet

Science.gov (United States)

Bansal, Lalit; Hatte, Sandeep; Basu, Saptarshi; Chakraborty, Suman

2017-09-01

Droplet evaporation under confinement is ubiquitous to multitude of applications such as microfluidics, surface patterning, and ink-jet printing. However, the rich physics governing the universality in the underlying dynamics remains grossly elusive. Here, we bring out hitherto unexplored universal features of the evaporation dynamics of a sessile droplet entrapped in a 3D confined fluidic environment. We show, through extensive set of experiments and theoretical formulations, that the evaporation timescale for such a droplet can be represented by a unique function of the initial conditions. Moreover, using same theoretical considerations, we are able to trace and universally merge the volume evolution history of the droplets along with evaporation lifetimes, irrespective of the extent of confinement. We also showcase the internal flow transitions caused by spatio-temporal variation of evaporation flux due to confinement. These findings may be of profound importance in designing functionalized droplet evaporation devices for emerging engineering and biomedical applications.

Core electron-root confinement (CERC) in helical plasmas

International Nuclear Information System (INIS)

Yokoyama, M.; Ida, K.; Maassbcrg, H.

2006-10-01

The improvement of core electron heat confinement has been realized in a wide range of helical devices such as CHS, LHD, TJ-II and W7-AS. Strongly peaked electron temperature profiles and large positive radial electric field, E r , in the core region are common fractures for this improved confinement. Such observations are consistent with a transition to the electron-root' solution of the ambipolarity condition for E r in the context of the neoclassical transport, which is unique to non-axisymmetric configurations. Based on this background, this improved confinement has been collectively dubbed 'core electron-root confinement' (CERC). The electron heat diffusivity is much reduced due to the electron-root E r compared to that with E r =0 assumed, which clearly demonstrates that 1/v ripple diffusion (ν being the collision frequency) in low-collisional helical plasmas could be overcome. The magnetic configuration properties play important roles in this transition, and thresholds are found for the collisionality and electron cyclotron heating (ECH) power. (author)

Topological superconductivity, topological confinement, and the vortex quantum Hall effect

International Nuclear Information System (INIS)

Diamantini, M. Cristina; Trugenberger, Carlo A.

2011-01-01

Topological matter is characterized by the presence of a topological BF term in its long-distance effective action. Topological defects due to the compactness of the U(1) gauge fields induce quantum phase transitions between topological insulators, topological superconductors, and topological confinement. In conventional superconductivity, because of spontaneous symmetry breaking, the photon acquires a mass due to the Anderson-Higgs mechanism. In this paper we derive the corresponding effective actions for the electromagnetic field in topological superconductors and topological confinement phases. In topological superconductors magnetic flux is confined and the photon acquires a topological mass through the BF mechanism: no symmetry breaking is involved, the ground state has topological order, and the transition is induced by quantum fluctuations. In topological confinement, instead, electric charge is linearly confined and the photon becomes a massive antisymmetric tensor via the Stueckelberg mechanism. Oblique confinement phases arise when the string condensate carries both magnetic and electric flux (dyonic strings). Such phases are characterized by a vortex quantum Hall effect potentially relevant for the dissipationless transport of information stored on vortices.

Cold pulse and rotation reversals with turbulence spreading and residual stress

DEFF Research Database (Denmark)

Hariri, F.; Naulin, Volker; Rasmussen, Jens Juul

2016-01-01

and the corresponding residual stress is absent. Our simulations are in qualitative agreement with measurements from ohmically heated plasmas. Rotation reversal at a finite radius is found in situations not displaying saturated confinement, which we identify as situations where the plasma is nearly everywhere unstable...

Visual Studio 2010 and NET 4 Six-in-One

CERN Document Server

Novak, Istvan; Granicz, Adam

2010-01-01

Complete coverage of all key .NET 4 and Visual Studio 2010 languages and technologies. .NET 4 is Microsoft's latest version of their core programming platform, and Visual Studio 2010 is the toolset that helps write .NET 4 applications. This comprehensive resource offers one-stop shopping for all you need to know to get productive with .NET 4. Experienced author and .NET guru Mitchel Sellers reviews all the important new features of .NET 4, including .NET charting and ASP.NET charting, ASP.NET dynamic data and jQuery, and the addition of F# as a supported package language. The expansive coverag

Confined aquifer vulnerability induced by a pumping well in a leakage area

Directory of Open Access Journals (Sweden)

X. Meng

2015-05-01

Full Text Available Due to the pollution of shallow groundwater and the rapid development of society and economy which consume more freshwater, the exploitation of confined groundwater is steadily increasing in north China. Therefore, the rapid decline of the confined groundwater head increases the risk of confined aquifer pollution by leaky recharge from shallow aquifers. In this paper, a quantitative method for assessing confined aquifer vulnerability to contamination due to pumping has been developed. This method is based on the shallow and confined groundwater flow model and the advection and dispersion in the aquitard, including sorption. The cumulative time for the pollutant concentration at the top boundary of confined aquifer exceeding the maximum allowable level is defined as the confined aquifer vulnerability index, which can be obtained by numerically solving the solute transport equation. A hypothetical example is chosen as a case study to illustrate the whole process. The results indicate that the proposed method is a practical and reasonable assessment method of confined aquifer vulnerability.

Synthesis of Polyimides in Molecular-Scale Confinement for Low-Density Hybrid Nanocomposites.

Science.gov (United States)

Isaacson, Scott G; Fostvedt, Jade I; Koerner, Hilmar; Baur, Jeffery W; Lionti, Krystelle; Volksen, Willi; Dubois, Geraud; Dauskardt, Reinhold H

2017-11-08

In this work, we exploit a confinement-induced molecular synthesis and a resulting bridging mechanism to create confined polyimide thermoset nanocomposites that couple molecular confinement-enhanced toughening with an unprecedented combination of high-temperature properties at low density. We describe a synthesis strategy that involves the infiltration of individual polymer chains through a nanoscale porous network while simultaneous imidization reactions increase the molecular backbone stiffness. In the extreme limit where the confinement length scale is much smaller than the polymer's molecular size, confinement-induced molecular mechanisms give rise to exceptional mechanical properties. We find that polyimide oligomers can undergo cross-linking reactions even in such molecular-scale confinement, increasing the molecular weight of the organic phase and toughening the nanocomposite through a confinement-induced energy dissipation mechanism. This work demonstrates that the confinement-induced molecular bridging mechanism can be extended to thermoset polymers with multifunctional properties, such as excellent thermo-oxidative stability and high service temperatures (>350 °C).

Neutron Assay System for Confinement Vessel Disposition

International Nuclear Information System (INIS)

Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

2012-01-01

Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1-inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the CVs. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of special nuclear material (SNM) in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of (le)100-g 239 Pu equivalent in a vessel for safeguards termination. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements.

Which nets are being used: factors associated with mosquito net use in Amhara, Oromia and Southern Nations, Nationalities and Peoples' Regions of Ethiopia.

Science.gov (United States)

Ngondi, Jeremiah M; Graves, Patricia M; Gebre, Teshome; Mosher, Aryc W; Shargie, Estifanos B; Emerson, Paul M; Richards, Frank O

2011-04-17

There has been recent large scale-up of malaria control interventions in Ethiopia where transmission is unstable. While household ownership of long-lasting insecticidal nets (LLIN) has increased greatly, there are concerns about inadequate net use. This study aimed to investigate factors associated with net use at two time points, before and after mass distribution of nets. Two cross sectional surveys were carried out in 2006 and 2007 in Amhara, Oromia and SNNP regions. The latter was a sub-sample of the national Malaria Indicator Survey (MIS 3R). Each survey wave used multi-stage cluster random sampling with 25 households per cluster (224 clusters with 5,730 households in Baseline 2006 and 245 clusters with 5,910 households in MIS 3R 2007). Net ownership was assessed by visual inspection while net utilization was reported as use of the net the previous night. This net level analysis was restricted to households owning at least one net of any type. Logistic regression models of association between net use and explanatory variables including net type, age, condition, cost and other household characteristics were undertaken using generalized linear latent and mixed models (GLLAMM). A total of 3,784 nets in 2,430 households were included in the baseline 2006 analysis while the MIS 3R 2007 analysis comprised 5,413 nets in 3,328 households. The proportion of nets used the previous night decreased from 85.1% to 56.0% between baseline 2006 and MIS 3R 2007, respectively. Factors independently associated with increased proportion of nets used were: LLIN net type (at baseline 2006); indoor residual spraying (at MIS 3R 2007); and increasing wealth index at both surveys. At both baseline 2006 and MIS 3R 2007, reduced proportion of nets used was independently associated with increasing net age, increasing damage of nets, increasing household net density, and increasing altitude (>2,000 m). This study identified modifiable factors affecting use of nets that were consistent

Which nets are being used: factors associated with mosquito net use in Amhara, Oromia and Southern Nations, Nationalities and Peoples' Regions of Ethiopia

Directory of Open Access Journals (Sweden)

Mosher Aryc W

2011-04-01

Full Text Available Abstract Background There has been recent large scale-up of malaria control interventions in Ethiopia where transmission is unstable. While household ownership of long-lasting insecticidal nets (LLIN has increased greatly, there are concerns about inadequate net use. This study aimed to investigate factors associated with net use at two time points, before and after mass distribution of nets. Methods Two cross sectional surveys were carried out in 2006 and 2007 in Amhara, Oromia and SNNP regions. The latter was a sub-sample of the national Malaria Indicator Survey (MIS 3R. Each survey wave used multi-stage cluster random sampling with 25 households per cluster (224 clusters with 5,730 households in Baseline 2006 and 245 clusters with 5,910 households in MIS 3R 2007. Net ownership was assessed by visual inspection while net utilization was reported as use of the net the previous night. This net level analysis was restricted to households owning at least one net of any type. Logistic regression models of association between net use and explanatory variables including net type, age, condition, cost and other household characteristics were undertaken using generalized linear latent and mixed models (GLLAMM. Results A total of 3,784 nets in 2,430 households were included in the baseline 2006 analysis while the MIS 3R 2007 analysis comprised 5,413 nets in 3,328 households. The proportion of nets used the previous night decreased from 85.1% to 56.0% between baseline 2006 and MIS 3R 2007, respectively. Factors independently associated with increased proportion of nets used were: LLIN net type (at baseline 2006; indoor residual spraying (at MIS 3R 2007; and increasing wealth index at both surveys. At both baseline 2006 and MIS 3R 2007, reduced proportion of nets used was independently associated with increasing net age, increasing damage of nets, increasing household net density, and increasing altitude (>2,000 m. Conclusion This study identified

Expected Net Present Value, Expected Net Future Value, and the Ramsey Rule

OpenAIRE

Gollier, Christian

2010-01-01

Weitzman (1998) showed that when future interest rates are uncertain, using the expected net present value implies a term structure of discount rates that is decreasing to the smallest possible interest rate. On the contrary, using the expected net future value criteria implies an increasing term structure of discount rates up to the largest possible interest rate. We reconcile the two approaches by introducing risk aversion and utility maximization. We show that if the aggregate consumption ...

Heat stress of two tropical seagrass species during low tides - impact on underwater net photosynthesis, dark respiration and diel in situ internal aeration

DEFF Research Database (Denmark)

Pedersen, Ole; Colmer, Timothy D.; Borum, Jens

2016-01-01

Seagrasses grow submerged in aerated seawater but often in low O2 sediments. Elevated temperatures and low O2 are stress factors. Internal aeration was measured in two tropical seagrasses, Thalassia hemprichii and Enhalus acoroides, growing with extreme tides and diel temperature amplitudes....... Temperature effects on net photosynthesis (PN) and dark respiration (RD) of leaves were evaluated. Daytime low tide was characterized by high pO2 (54 kPa), pH (8.8) and temperature (38°C) in shallow pools. As PN was maximum at 33°C (9.1 and 7.2 μmol O2 m-2 s-1 in T. hemprichii and E. acoroides, respectively......), the high temperatures and reduced CO2 would have diminished PN, whereas RD increased (Q10 of 2.0-2.7) above that at 33°C (0.45 and 0.33 μmol O2 m-2 s-1, respectively). During night-time low tides, O2 declined resulting in shoot base anoxia in both species, but incoming water containing c. 20 kPa O2...

Ion Transport and Precipitation Kinetics as Key Aspects of Stress Generation on Pore Walls Induced by Salt Crystallization

Science.gov (United States)

Naillon, A.; Joseph, P.; Prat, M.

2018-01-01

The stress generation on pore walls due to the growth of a sodium chloride crystal in a confined aqueous solution is studied from evaporation experiments in microfluidic channels in conjunction with numerical computations of crystal growth. The study indicates that the stress buildup on the pore walls is a highly transient process taking place over a very short period of time (in less than 1 s in our experiments). The analysis makes clear that what matters for the stress generation is not the maximum supersaturation at the onset of the crystal growth but the supersaturation at the interface between the solution and the crystal when the latter is about to be confined between the pore walls. The stress generation is summarized in a simple stress diagram involving the pore aspect ratio and the Damkhöler number characterizing the competition between the precipitation reaction kinetics and the ion transport towards the growing crystal. This opens up the route for a better understanding of the damage of porous materials induced by salt crystallization, an important issue in Earth sciences, reservoir engineering, and civil engineering.

Studies on the quark confinement in a non-relativistic quark model

International Nuclear Information System (INIS)

Pfenninger, T.

1988-01-01

In the framework of the non-relativistic quark model we have studied several aspects of the description of the confinement by a confinement potential. A first consideration applied to the effects of the long-range color van-der-Waals forces on the nucleon-nucleon scattering. Regarding color dipole states as an additional closed channel in a dynamical and nonlocal resonating-group calculation we found a strong attraction. Additionally it was possible by means of the RGM kernels to derive an against earlier calculations improved color van-der-Waals potential in adiabatic approximation which regards correctly the internal kinetic and the confinement energy of the color octet states. This potential is not confined to large NN distances and shows asymptotically a 1/R 2 behaviour if it is based on a harmonic confinement. A further study applied to the question how far a possible vector character of the confinement, which is suggested by the elementary quark-gluon vertex, has effects on baryon properties and the NN interaction. Here it resulted that the vector confinement reacts in view of the model parameters very sensitively in the baryon properties whereas the scalar confinement did not show this dependence. In the NN scattering this vector confinement however plays a more secondary role. Because of the difficulties of the usual confinement potential with long-range color van-der-Waals forces we proposed in the last part a new potential and additional orthogonality relations for the quark wave functions in order to accomodate in the potential model to the string degrees of freedom. In scattering calculations we again studied the effects of the modification on the NN interaction. (orig./HSI) [de

Confined exciton spectroscopy

International Nuclear Information System (INIS)

Torres, Clivia M.S.

1998-01-01

Full text: In this work, the exciton is considered as a sensor of the electronic and optical properties of materials such as semiconductors, which have size compared to the exciton De Broglie wavelength, approximately 20 nm, depending on the semiconductor. Examples of electron-phonon, electron-electron, photon-electron, exciton-polariton, phonon-plasmon, are presented, under different confinement conditions such as quantum wells, superlattices

Discrete, continuous, and hybrid petri nets

CERN Document Server

David, René

2004-01-01

Petri nets do not designate a single modeling formalism. In fact, newcomers to the field confess sometimes to be a little puzzled by the diversity of formalisms that are recognized under this "umbrella". Disregarding some extensions to the theoretical modeling capabilities, and looking at the level of abstraction of the formalisms, Condition/Event, Elementary, Place/Transition, Predicate/Transition, Colored, Object Oriented... net systems are frequently encountered in the literature. On the other side, provided with appropriate interpretative extensions, Controled Net Systems, Marking Diagrams (the Petri net generalization of State Diagrams), or the many-many variants in which time can be explicitly incorporated -Time(d), Deterministic, (Generalized) Stochastic, Fuzzy...- are defined. This represents another way to define practical formalisms that can be obtained by the "cro- product" of the two mentioned dimensions. Thus Petri nets constitute a modeling paradigm, understandable in a broad sense as "the total...

Alternative lines with magnetic plasma confinement

International Nuclear Information System (INIS)

Wobig, H.

1981-01-01

Plasma confinement with the aid of a magnetic field is the most common and also the most frequently investigated principle on the way to controlled nuclear fusion. Apart from the Tokamak principle, which is the most advanced principle as far as fusion-relevant plasma parameters are concerned, also other approaches are being investigated, e.g. the mirror device, the bumpy tons, and the stellarator. In principle, all three concepts permit 'stationary' plasma confinement in a stationary fusion reactor. Compared with the pulsed Tokamak reactor, this is a considerable advantage. (orig./GG) [de

Magnetic properties of confined electron gas

International Nuclear Information System (INIS)

Felicio, J.R.D. de.

1977-04-01

The effects of confinement by a two or three-dimensional harmonic potential on the magnetic properties of a free electron gas are investigated using the grand-canonical ensemble framework. At high temperatures an extension of Darwin's, Felderhof and Raval's works is made taking into account spin effects at low temperature. A comprehensive description of the magnetic properties of a free electron gas is given. The system is regarded as finite, but the boundary condition psi=0 is not introduced. The limits of weak and strong confinement are also analysed [pt

Surface motion and confinement potential for a microwave confined corona

International Nuclear Information System (INIS)

Ensley, D.L.

1979-07-01