Science.gov

Sample records for fixed point unravelling

  1. Multiple Fixed-Point Cell

    NASA Astrophysics Data System (ADS)

    Edler, F.; Ederer, P.

    2014-07-01

    The paper describes the construction and investigation of multiple fixed-point cells usable for the calibration of thermocouples at temperatures above 1100 C. These fixed-point cells made of pure graphite are characterized by a simple construction as well as by a flexible application. The cylindrical basic mount is equipped with a central hole for the insertion of a thermocouple, and with eight drill holes containing exchangeable cartridges which surround the central bore axially symmetrically. The cartridges are filled with different metal-carbon (Me-C) eutectics: cobalt-carbon (Co-C), nickel-carbon (Ni-C), palladium-carbon (Pd-C), and rhodium-carbon (Rh-C). The melting temperatures of the different Me-C eutectics of the cartridges were compared to the melting temperatures of commonly used Me-C eutectic fixed-point cells of the Physikalisch-Technische Bundesanstalt by using a Pt/Pd thermocouple (Co-C, Ni-C) and Type B thermocouples (Pd-C, Rh-C). The uncertainties () of the emfs measured at the inflection points of the melting curves are in the order of a few V which correspond to temperature equivalents between 0.3 K and 0.6 K. Furthermore, the difference between the melting temperatures of the Co-C and Ni-C cartridges was found to be 4.2 K by using simultaneously two sets of four cartridges filled with the two materials and placed alternately in the eight outer holes of one basic mount.

  2. Anderson Acceleration for Fixed-Point Iterations

    SciTech Connect

    Walker, Homer F.

    2015-08-31

    The purpose of this grant was to support research on acceleration methods for fixed-point iterations, with applications to computational frameworks and simulation problems that are of interest to DOE.

  3. Characterizations of fixed points of quantum operations

    SciTech Connect

    Li Yuan

    2011-05-15

    Let {phi}{sub A} be a general quantum operation. An operator B is said to be a fixed point of {phi}{sub A}, if {phi}{sub A}(B)=B. In this note, we shall show conditions under which B, a fixed point {phi}{sub A}, implies that B is compatible with the operation element of {phi}{sub A}. In particular, we offer an extension of the generalized Lueders theorem.

  4. ASIC For Complex Fixed-Point Arithmetic

    NASA Technical Reports Server (NTRS)

    Petilli, Stephen G.; Grimm, Michael J.; Olson, Erlend M.

    1995-01-01

    Application-specific integrated circuit (ASIC) performs 24-bit, fixed-point arithmetic operations on arrays of complex-valued input data. High-performance, wide-band arithmetic logic unit (ALU) designed for use in computing fast Fourier transforms (FFTs) and for performing ditigal filtering functions. Other applications include general computations involved in analysis of spectra and digital signal processing.

  5. Precise Point Positioning with Partial Ambiguity Fixing.

    PubMed

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  6. Precise Point Positioning with Partial Ambiguity Fixing

    PubMed Central

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  7. Secure Computation with Fixed-Point Numbers

    NASA Astrophysics Data System (ADS)

    Catrina, Octavian; Saxena, Amitabh

    Secure computation is a promising approach to business problems in which several parties want to run a joint application and cannot reveal their inputs. Secure computation preserves the privacy of input data using cryptographic protocols, allowing the parties to obtain the benefits of data sharing and at the same time avoid the associated risks. These business applications need protocols that support all the primitive data types and allow secure protocol composition and efficient application development. Secure computation with rational numbers has been a challenging problem. We present in this paper a family of protocols for multiparty computation with rational numbers using fixed-point representation. This approach offers more efficient solutions for secure computation than other usual representations.

  8. Floating-to-Fixed-Point Conversion for Digital Signal Processors

    NASA Astrophysics Data System (ADS)

    Menard, Daniel; Chillet, Daniel; Sentieys, Olivier

    2006-12-01

    Digital signal processing applications are specified with floating-point data types but they are usually implemented in embedded systems with fixed-point arithmetic to minimise cost and power consumption. Thus, methodologies which establish automatically the fixed-point specification are required to reduce the application time-to-market. In this paper, a new methodology for the floating-to-fixed point conversion is proposed for software implementations. The aim of our approach is to determine the fixed-point specification which minimises the code execution time for a given accuracy constraint. Compared to previous methodologies, our approach takes into account the DSP architecture to optimise the fixed-point formats and the floating-to-fixed-point conversion process is coupled with the code generation process. The fixed-point data types and the position of the scaling operations are optimised to reduce the code execution time. To evaluate the fixed-point computation accuracy, an analytical approach is used to reduce the optimisation time compared to the existing methods based on simulation. The methodology stages are described and several experiment results are presented to underline the efficiency of this approach.

  9. Fixed points for weakly inward mappings in Banach spaces

    NASA Astrophysics Data System (ADS)

    Xu, Shaoyuan; Jia, Baoguo; Li, Guo-Zhen

    2006-07-01

    S. Hu and Y. Sun [S. Hu, Y. Sun, Fixed point index for weakly inward mappings, J. Math. Anal. Appl. 172 (1993) 266-273] defined the fixed point index for weakly inward mappings, investigated its properties and studied the fixed points for such mappings. In this paper, following S. Hu and Y. Sun, we continue to investigate boundary conditions, under which the fixed point index for the completely continuous and weakly inward mapping, denoted by i(A,[Omega],P), is equal to 1 or 0. Correspondingly, we can obtain some new fixed point theorems of the completely continuous and weakly inward mappings and existence theorems of solutions for the equations Ax=[mu]x, which extend many famous theorems such as Leray-Schauder's theorem, Rothe's two theorems, Krasnoselskii's theorem, Altman's theorem, Petryshyn's theorem, etc., to the case of weakly inward mappings. In addition, our conclusions and methods are different from the ones in many recent works.

  10. A new compact fixed-point blackbody furnace

    SciTech Connect

    Hiraka, K.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T.; Yamada, Y.; Ishii, J.

    2013-09-11

    More and more NMIs are realizing their primary scale themselves with fixed-point blackbodies as their reference standard. However, commercially available fixed-point blackbody furnaces of sufficient quality are not always easy to obtain. CHINO Corp. and NMIJ, AIST jointly developed a new compact fixed-point blackbody furnace. The new furnace has such features as 1) improved temperature uniformity when compared to previous products, enabling better plateau quality, 2) adoption of the hybrid fixed-point cell structure with internal insulation to improve robustness and thereby to extend lifetime, 3) easily ejectable and replaceable heater unit and fixed-point cell design, leading to reduced maintenance cost, 4) interchangeability among multiple fixed points from In to Cu points. The replaceable cell feature facilitates long term maintenance of the scale through management of a group of fixed-point cells of the same type. The compact furnace is easily transportable and therefore can also function as a traveling standard for disseminating the radiation temperature scale, and for maintaining the scale at the secondary level and industrial calibration laboratories. It is expected that the furnace will play a key role of the traveling standard in the anticipated APMP supplementary comparison of the radiation thermometry scale.

  11. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  12. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  13. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  14. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  15. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  16. Contractive multifunctions, fixed point inclusions and iterated multifunction systems

    NASA Astrophysics Data System (ADS)

    Kunze, H. E.; La Torre, D.; Vrscay, E. R.

    2007-06-01

    We study the properties of multifunction operators that are contractive in the Covitz-Nadler sense. In this situation, such operators T possess fixed points satisfying the relation x[set membership, variant]Tx. We introduce an iterative method involving projections that guarantees convergence from any starting point x0[set membership, variant]X to a point x[set membership, variant]XT, the set of all fixed points of a multifunction operator T. We also prove a continuity result for fixed point sets XT as well as a "generalized collage theorem" for contractive multifunctions. These results can then be used to solve inverse problems involving contractive multifunctions. Two applications of contractive multifunctions are introduced: (i) integral inclusions and (ii) iterated multifunction systems.

  17. Stray thermal influences in zinc fixed-point cells

    SciTech Connect

    Rudtsch, S.; Aulich, A.; Monte, C.

    2013-09-11

    The influence of thermal effects is a major uncertainty contribution to the calibration of Standard Platinum Resistance Thermometers (SPRTs) in fixed-point cells. Axial heat losses strongly depend on the fixed-point temperature, constructional details of cells and SPRTs and the resulting heat transfer between cell, thermometer, furnace and environment. At the zinc point contributions by heat conduction and thermal radiation must be considered. Although the measurement of temperature gradients in the re-entrant well of a fixed-point cell provides very important information about the influence of axial heat losses, further investigations are required for a reliable estimate of the resulting uncertainty contribution. It is shown that specific modifications of a zinc fixed-point cell, following generally accepted principles, may result in systematic deviations of the measured fixed-point temperatures larger than typically stated in the uncertainty budget of National Metrology Institutes (NMIs). The underlying heat transport processes are investigated and the consequences for the construction of zinc cells are discussed.

  18. Design and DSP Implementation of Fixed-Point Systems

    NASA Astrophysics Data System (ADS)

    Coors, Martin; Keding, Holger; Lüthje, Olaf; Meyr, Heinrich

    2002-12-01

    This article is an introduction to the FRIDGE design environment which supports the design and DSP implementation of fixed-point digital signal processing systems. We present the tool-supported transformation of signal processing algorithms coded in floating-point ANSI C to a fixed-point representation in SystemC. We introduce the novel approach to control and data flow analysis, which is necessary for the transformation. The design environment enables fast bit-true simulation by mapping the fixed-point algorithm to integral data types of the host machine. A speedup by a factor of 20 to 400 can be achieved compared to C++-library-based bit-true simulation. FRIDGE also provides a direct link to DSP implementation by processor specific C code generation and advanced code optimization.

  19. Border collisions inside the stability domain of a fixed point

    NASA Astrophysics Data System (ADS)

    Avrutin, Viktor; Zhusubaliyev, Zhanybai T.; Mosekilde, Erik

    2016-05-01

    Recent studies on a power electronic DC/AC converter (inverter) have demonstrated that such systems may undergo a transition from regular dynamics (associated with a globally attracting fixed point of a suitable stroboscopic map) to chaos through an irregular sequence of border-collision events. Chaotic dynamics of an inverter is not suitable for practical purposes. However, the parameter domain in which the stroboscopic map has a globally attracting fixed point has generally been considered to be uniform and suitable for practical use. In the present paper we show that this domain actually has a complicated interior structure formed by boundaries defined by persistence border collisions. We describe a simple approach that is based on symbolic dynamics and makes it possible to detect such boundaries numerically. Using this approach we describe several regions in the parameter space leading to qualitatively different output signals of the inverter although all associated with globally attracting fixed points of the corresponding stroboscopic map.

  20. Fixed point structure of the Abelian Higgs model

    NASA Astrophysics Data System (ADS)

    Fejős, G.; Hatsuda, T.

    2016-06-01

    The order of the superconducting phase transition is analyzed via the functional renormalization group approach. For the first time, we derive fully analytic expressions for the β functions of the charge and the self-coupling in the Abelian Higgs model with one complex scalar field in d =3 dimensions that support the existence of two charged fixed points: an infrared (IR) stable fixed point describing a second-order phase transition and a tricritical fixed point controlling the region of the parameter space that is attracted by the former one. It is found that the region separating first- and second-order transitions can be uniquely characterized by the Ginzburg-Landau parameter κ , and the system undergoes a second-order transition only if κ >κc≈0.62 /√{2 }.

  1. Fixed-Rate Compressed Floating-Point Arrays.

    PubMed

    Lindstrom, Peter

    2014-12-01

    Current compression schemes for floating-point data commonly take fixed-precision values and compress them to a variable-length bit stream, complicating memory management and random access. We present a fixed-rate, near-lossless compression scheme that maps small blocks of 4(d) values in d dimensions to a fixed, user-specified number of bits per block, thereby allowing read and write random access to compressed floating-point data at block granularity. Our approach is inspired by fixed-rate texture compression methods widely adopted in graphics hardware, but has been tailored to the high dynamic range and precision demands of scientific applications. Our compressor is based on a new, lifted, orthogonal block transform and embedded coding, allowing each per-block bit stream to be truncated at any point if desired, thus facilitating bit rate selection using a single compression scheme. To avoid compression or decompression upon every data access, we employ a software write-back cache of uncompressed blocks. Our compressor has been designed with computational simplicity and speed in mind to allow for the possibility of a hardware implementation, and uses only a small number of fixed-point arithmetic operations per compressed value. We demonstrate the viability and benefits of lossy compression in several applications, including visualization, quantitative data analysis, and numerical simulation. PMID:26356981

  2. Measurement of thermodynamic temperature of high temperature fixed points

    SciTech Connect

    Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I.

    2013-09-11

    The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 'Radiation Thermometry'. The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.

  3. Fixed Point Problems for Linear Transformations on Pythagorean Triples

    ERIC Educational Resources Information Center

    Zhan, M.-Q.; Tong, J.-C.; Braza, P.

    2006-01-01

    In this article, an attempt is made to find all linear transformations that map a standard Pythagorean triple (a Pythagorean triple [x y z][superscript T] with y being even) into a standard Pythagorean triple, which have [3 4 5][superscript T] as their fixed point. All such transformations form a monoid S* under matrix product. It is found that S*…

  4. Partial Rectangular Metric Spaces and Fixed Point Theorems

    PubMed Central

    2014-01-01

    The purpose of this paper is to introduce the concept of partial rectangular metric spaces as a generalization of rectangular metric and partial metric spaces. Some properties of partial rectangular metric spaces and some fixed point results for quasitype contraction in partial rectangular metric spaces are proved. Some examples are given to illustrate the observed results. PMID:24672366

  5. A fixed-point framework for launch vehicle ascent guidance

    NASA Astrophysics Data System (ADS)

    Zhang, Lijun

    Recent interests in responsive launch have highlighted the need for rapid and fully automated ascent guidance planning and guidance parameter generation for launch vehicles. This dissertation aims at developing methodology and algorithms for on-demand generation of optimal launch vehicle ascent trajectories from lift-off to achieving targeting conditions outside the atmosphere. The entire ascent trajectory from lift-off to final target point is divided into two parts: atmospheric ascent portion and vacuum ascent portion. The two portions are integrated via a fixed-point iteration based on the continuity condition at the switch point between atmospheric ascent portion and vacuum ascent portion. The previous research works on closed-loop endo-atmospheric ascent guidance shows that the classical finite difference method is well suited for fast solution of the constrained optimal three-dimensional ascent problem. The exploitation of certain unique features in the integration procedure between the atmospheric portion and vacuum portion and the finite difference method, allows us to cast the atmospheric ascent problem into a nested fixed-point iteration problem. Therefore a novel Fixed-Point Iteration algorithm is presented for solving the endo-atmospheric ascent guidance problem. Several approaches are also provided for facilitating the convergence of the fixed-point iteration. The exo-atmospheric ascent portion allows an optimal coast in between the two vacuum powered stages. The optimal coast enables more efficient usage of the propellant. The Analytical Multiple-Shooting algorithm is developed to find the optimal trajectory for this portion. A generic launch vehicle model is adopted in the numerical simulation. A series of open-loop and closed-loop simulations are performed. The results verify the effectiveness, robustness and reliability of the Fixed-Point Iteration (FPI) algorithm and Analytical Multiple-Shooting (AMS) algorithm developed in this research. In

  6. Fixed-rate compressed floating-point arrays

    Energy Science and Technology Software Center (ESTSC)

    2014-03-30

    ZFP is a library for lossy compression of single- and double-precision floating-point data. One of the unique features of ZFP is its support for fixed-rate compression, which enables random read and write access at the granularity of small blocks of values. Using a C++ interface, this allows declaring compressed arrays (1D, 2D, and 3D arrays are supported) that through operator overloading can be treated just like conventional, uncompressed arrays, but which allow the user tomore » specify the exact number of bits to allocate to the array. ZFP also has variable-rate fixed-precision and fixed-accuracy modes, which allow the user to specify a tolerance on the relative or absolute error.« less

  7. Gravity Duals of Lifshitz-Like Fixed Points

    SciTech Connect

    Kachru, Shamit; Liu, Xiao; Mulligan, Michael; /Stanford U., Phys. Dept. /SLAC

    2008-11-05

    We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our theories are characterized by a dynamical critical exponent z, which governs the anisotropy between spatial and temporal scaling t {yields} {lambda}{sup z}t, x {yields} {lambda}x; we focus on the case with z = 2. Such theories describe multicritical points in certain magnetic materials and liquid crystals, and have been shown to arise at quantum critical points in toy models of the cuprate superconductors. This work can be considered a small step towards making useful dual descriptions of such critical points.

  8. Fixed points, stable manifolds, weather regimes, and their predictability

    DOE PAGESBeta

    Deremble, Bruno; D'Andrea, Fabio; Ghil, Michael

    2009-10-27

    In a simple, one-layer atmospheric model, we study the links between low-frequency variability and the model’s fixed points in phase space. The model dynamics is characterized by the coexistence of multiple ''weather regimes.'' To investigate the transitions from one regime to another, we focus on the identification of stable manifolds associated with fixed points. We show that these manifolds act as separatrices between regimes. We track each manifold by making use of two local predictability measures arising from the meteorological applications of nonlinear dynamics, namely, ''bred vectors'' and singular vectors. These results are then verified in the framework of ensemblemore » forecasts issued from clouds (ensembles) of initial states. The divergence of the trajectories allows us to establish the connections between zones of low predictability, the geometry of the stable manifolds, and transitions between regimes.« less

  9. Fixed points, stable manifolds, weather regimes, and their predictability

    SciTech Connect

    Deremble, Bruno; D'Andrea, Fabio; Ghil, Michael

    2009-10-27

    In a simple, one-layer atmospheric model, we study the links between low-frequency variability and the model’s fixed points in phase space. The model dynamics is characterized by the coexistence of multiple ''weather regimes.'' To investigate the transitions from one regime to another, we focus on the identification of stable manifolds associated with fixed points. We show that these manifolds act as separatrices between regimes. We track each manifold by making use of two local predictability measures arising from the meteorological applications of nonlinear dynamics, namely, ''bred vectors'' and singular vectors. These results are then verified in the framework of ensemble forecasts issued from clouds (ensembles) of initial states. The divergence of the trajectories allows us to establish the connections between zones of low predictability, the geometry of the stable manifolds, and transitions between regimes.

  10. The computational core and fixed point organization in Boolean networks

    NASA Astrophysics Data System (ADS)

    Correale, L.; Leone, M.; Pagnani, A.; Weigt, M.; Zecchina, R.

    2006-03-01

    In this paper, we analyse large random Boolean networks in terms of a constraint satisfaction problem. We first develop an algorithmic scheme which allows us to prune simple logical cascades and underdetermined variables, returning thereby the computational core of the network. Second, we apply the cavity method to analyse the number and organization of fixed points. We find in particular a phase transition between an easy and a complex regulatory phase, the latter being characterized by the existence of an exponential number of macroscopically separated fixed point clusters. The different techniques developed are reinterpreted as algorithms for the analysis of single Boolean networks, and they are applied in the analysis of and in silico experiments on the gene regulatory networks of baker's yeast (Saccharomyces cerevisiae) and the segment-polarity genes of the fruitfly Drosophila melanogaster.

  11. Fixed point structure of quenched, planar quantum electrodynamics

    SciTech Connect

    Love, S.T.

    1986-07-01

    Gauge theories exhibiting a hierarchy of fermion mass scales may contain a pseudo-Nambu-Boldstone boson of spontaneously broken scale invariance. The relation between scale and chiral symmetry breaking is studied analytically in quenched, planar quantum electrodynamics in four dimensions. The model possesses a novel nonperturbative ultraviolet fixed point governing its strong coupling phase which requires the mixing of four fermion operators. 12 refs.

  12. Fate of CPN-1 fixed points with q monopoles.

    PubMed

    Block, Matthew S; Melko, Roger G; Kaul, Ribhu K

    2013-09-27

    We present an extensive quantum Monte Carlo study of the Néel to valence-bond solid (VBS) phase transition on rectangular- and honeycomb-lattice SU(N) antiferromagnets in sign-problem-free models. We find that in contrast to the honeycomb lattice and previously studied square-lattice systems, on the rectangular lattice for small N, a first-order Néel-VBS transition is realized. On increasing N≥4, we observe that the transition becomes continuous and with the same universal exponents as found on the honeycomb and square lattices (studied here for N=5, 7, 10), providing strong support for a deconfined quantum critical point. Combining our new results with previous numerical and analytical studies, we present a general phase diagram of the stability of CPN-1 fixed points with q monopoles. PMID:24116811

  13. Accuracy and Efficiency in Fixed-Point Neural ODE Solvers.

    PubMed

    Hopkins, Michael; Furber, Steve

    2015-10-01

    Simulation of neural behavior on digital architectures often requires the solution of ordinary differential equations (ODEs) at each step of the simulation. For some neural models, this is a significant computational burden, so efficiency is important. Accuracy is also relevant because solutions can be sensitive to model parameterization and time step. These issues are emphasized on fixed-point processors like the ARM unit used in the SpiNNaker architecture. Using the Izhikevich neural model as an example, we explore some solution methods, showing how specific techniques can be used to find balanced solutions. We have investigated a number of important and related issues, such as introducing explicit solver reduction (ESR) for merging an explicit ODE solver and autonomous ODE into one algebraic formula, with benefits for both accuracy and speed; a simple, efficient mechanism for cancelling the cumulative lag in state variables caused by threshold crossing between time steps; an exact result for the membrane potential of the Izhikevich model with the other state variable held fixed. Parametric variations of the Izhikevich neuron show both similarities and differences in terms of algorithms and arithmetic types that perform well, making an overall best solution challenging to identify, but we show that particular cases can be improved significantly using the techniques described. Using a 1 ms simulation time step and 32-bit fixed-point arithmetic to promote real-time performance, one of the second-order Runge-Kutta methods looks to be the best compromise; Midpoint for speed or Trapezoid for accuracy. SpiNNaker offers an unusual combination of low energy use and real-time performance, so some compromises on accuracy might be expected. However, with a careful choice of approach, results comparable to those of general-purpose systems should be possible in many realistic cases. PMID:26313605

  14. Epidemiological study of fixed drug eruption in Pointe-Noire.

    PubMed

    Ognongo-Ibiaho, A N; Atanda, H L

    2012-11-01

    A prospective study was conducted over a 27 month period in order to determine the epidemiological profile of fixed drug eruption (FDE) observed during a dermatological consultation at Pointe-Noire. During the study period 54 out of 9,070 persons consulting (0.6%) suffered from clinically diagnosed FDE. The variables studied were: age, sex, medicine and point of sale. The average age of onset was 30 years. The frequency of onset was higher in males (38 patients) than in females (16 patients). The incriminated medicines were: the sulfamides (48 patients) including Cotrimoxazole (45 patients ) and Sulfadoxine and Pyremethamine (3 patients) Coartem(®) + Doliprane(®) (1 patient), Chloramphenicol(®) (1 patient), Amidol(®) (1 patient), Duocotexin(®) + Paracetamol(®) (1 patient), Surquina(®) (1 patient), Amodiaquine(®) (1 patient). The point of sale was illicit (peddlers, markets) for 44 patients; for 10 patients it was a lawful outlet (pharmacies). This study shows that cotrimoxazole bought at illicit points of sale is the main etiology of FDE in the department, confirming that these medicines are counterfeit. The involvement of dermatologists in the fight against the illicit sale of medicines should be made a priority. PMID:23210952

  15. Fixed Point Transformations Based Iterative Control of a Polymerization Reaction

    NASA Astrophysics Data System (ADS)

    Tar, József K.; Rudas, Imre J.

    As a paradigm of strongly coupled non-linear multi-variable dynamic systems the mathematical model of the free-radical polymerization of methyl-metachrylate with azobis (isobutyro-nitrile) as an initiator and toluene as a solvent taking place in a jacketed Continuous Stirred Tank Reactor (CSTR) is considered. In the adaptive control of this system only a single input variable is used as the control signal (the process input, i.e. dimensionless volumetric flow rate of the initiator), and a single output variable is observed (the process output, i.e. the number-average molecular weight of the polymer). Simulation examples illustrate that on the basis of a very rough and primitive model consisting of two scalar variables various fixed-point transformations based convergent iterations result in a novel, sophisticated adaptive control.

  16. A Fixed-Point Iteration Method with Quadratic Convergence

    SciTech Connect

    Walker, Kevin P.; Sham, Sam

    2012-01-01

    The fixed-point iteration algorithm is turned into a quadratically convergent scheme for a system of nonlinear equations. Most of the usual methods for obtaining the roots of a system of nonlinear equations rely on expanding the equation system about the roots in a Taylor series, and neglecting the higher order terms. Rearrangement of the resulting truncated system then results in the usual Newton-Raphson and Halley type approximations. In this paper the introduction of unit root functions avoids the direct expansion of the nonlinear system about the root, and relies, instead, on approximations which enable the unit root functions to considerably widen the radius of convergence of the iteration method. Methods for obtaining higher order rates of convergence and larger radii of convergence are discussed.

  17. Fixed-point error analysis of Winograd Fourier transform algorithms

    NASA Technical Reports Server (NTRS)

    Patterson, R. W.; Mcclellan, J. H.

    1978-01-01

    The quantization error introduced by the Winograd Fourier transform algorithm (WFTA) when implemented in fixed-point arithmetic is studied and compared with that of the fast Fourier transform (FFT). The effect of ordering the computational modules and the relative contributions of data quantization error and coefficient quantization error are determined. In addition, the quantization error introduced by the Good-Winograd (GW) algorithm, which uses Good's prime-factor decomposition for the discrete Fourier transform (DFT) together with Winograd's short length DFT algorithms, is studied. Error introduced by the WFTA is, in all cases, worse than that of the FFT. In general, the WFTA requires one or two more bits for data representation to give an error similar to that of the FFT. Error introduced by the GW algorithm is approximately the same as that of the FFT.

  18. Fixed-Point Optimization of Atoms and Density in DFT.

    PubMed

    Marks, L D

    2013-06-11

    I describe an algorithm for simultaneous fixed-point optimization (mixing) of the density and atomic positions in Density Functional Theory calculations which is approximately twice as fast as conventional methods, is robust, and requires minimal to no user intervention or input. The underlying numerical algorithm differs from ones previously proposed in a number of aspects and is an autoadaptive hybrid of standard Broyden methods. To understand how the algorithm works in terms of the underlying quantum mechanics, the concept of algorithmic greed for different Broyden methods is introduced, leading to the conclusion that if a linear model holds that the first Broyden method is optimal, the second if a linear model is a poor approximation. How this relates to the algorithm is discussed in terms of electronic phase transitions during a self-consistent run which results in discontinuous changes in the Jacobian. This leads to the need for a nongreedy algorithm when the charge density crosses phase boundaries, as well as a greedy algorithm within a given phase. An ansatz for selecting the algorithm structure is introduced based upon requiring the extrapolated component of the curvature condition to have projected positive eigenvalues. The general convergence of the fixed-point methods is briefly discussed in terms of the dielectric response and elastic waves using known results for quasi-Newton methods. The analysis indicates that both should show sublinear dependence with system size, depending more upon the number of different chemical environments than upon the number of atoms, consistent with the performance of the algorithm and prior literature. This is followed by details of algorithm ranging from preconditioning to trust region control. A number of results are shown, finishing up with a discussion of some of the many open questions. PMID:26583869

  19. Consistent Perturbative Fixed Point Calculations in QCD and Supersymmetric QCD

    NASA Astrophysics Data System (ADS)

    Ryttov, Thomas A.

    2016-08-01

    We suggest how to consistently calculate the anomalous dimension γ* of the ψ ¯ ψ operator in finite order perturbation theory at an infrared fixed point for asymptotically free theories. If the n +1 loop beta function and n loop anomalous dimension are known, then γ* can be calculated exactly and fully scheme independently in a Banks-Zaks expansion through O (Δfn) , where Δf=N¯ f-Nf , Nf is the number of flavors, and N¯f is the number of flavors above which asymptotic freedom is lost. For a supersymmetric theory, the calculation preserves supersymmetry order by order in Δf. We then compute γ* through O (Δf2) for supersymmetric QCD in the dimensional reduction scheme and find that it matches the exact known result. We find that γ* is astonishingly well described in perturbation theory already at the few loops level throughout the entire conformal window. We finally compute γ* through O (Δf3) for QCD and a variety of other nonsupersymmetric fermionic gauge theories. Small values of γ* are observed for a large range of flavors.

  20. Consistent Perturbative Fixed Point Calculations in QCD and Supersymmetric QCD.

    PubMed

    Ryttov, Thomas A

    2016-08-12

    We suggest how to consistently calculate the anomalous dimension γ_{*} of the ψ[over ¯]ψ operator in finite order perturbation theory at an infrared fixed point for asymptotically free theories. If the n+1 loop beta function and n loop anomalous dimension are known, then γ_{*} can be calculated exactly and fully scheme independently in a Banks-Zaks expansion through O(Δ_{f}^{n}), where Δ_{f}=N[over ¯]_{f}-N_{f}, N_{f} is the number of flavors, and N[over ¯]_{f} is the number of flavors above which asymptotic freedom is lost. For a supersymmetric theory, the calculation preserves supersymmetry order by order in Δ_{f}. We then compute γ_{*} through O(Δ_{f}^{2}) for supersymmetric QCD in the dimensional reduction scheme and find that it matches the exact known result. We find that γ_{*} is astonishingly well described in perturbation theory already at the few loops level throughout the entire conformal window. We finally compute γ_{*} through O(Δ_{f}^{3}) for QCD and a variety of other nonsupersymmetric fermionic gauge theories. Small values of γ_{*} are observed for a large range of flavors. PMID:27563948

  1. Some Extensions of Discrete Fixed Point Theorems and Their Applications to the Game Theory

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hidefumi

    2009-09-01

    As is well-known in the game theory, fixed point theorems are useful to show the existence of Nash equilibrium. Since they are mathematical tools in continuous variables, it is expected that discrete fixed point theorems also useful to guarantee the existence of pure-strategy Nash equilibrium. In this talk, we review three types of discrete fixed point theorems, give some extensions, and apply them to non-cooperative games.

  2. Existence and comparison results for fixed points of multifunctions with applications to normal-form games

    NASA Astrophysics Data System (ADS)

    Heikkila, S.

    2007-08-01

    In this paper we apply generalized iteration methods to prove comparison results which show how fixed points of a multifunction can be bounded by least and greatest fixed points of single-valued functions. As an application we prove existence and comparison results for fixed points of multifunctions. These results are applied to normal-form games, by proving existence and comparison results for pure and mixed Nash equilibria and their utilities.

  3. Composition analysis of large samples with PGNAA using a fixed point iteration

    NASA Astrophysics Data System (ADS)

    Akkurt, Hatice

    2002-09-01

    The composition problem in large sample prompt gamma neutron activation analysis (PGNAA) is a nonlinear inverse problem. The basic form of the nonlinear inverse composition problem is presented. This problem is then formulated in a general way, as a fixed point problem, without addressing any specific application or sample type or linearization approach. This approach of formulating the problem as a fixed point problem suggested a natural fixed point iteration. The algorithm of the fixed point iteration solves the nonlinear composition problem using a combination of measured and computed data. The effectiveness of the fixed point iteration for composition analysis is demonstrated using purely numerical experiments. These numerical experiments showed that the fixed point iteration can be successfully applied to find the bulk composition of large samples, with excellent agreement between the estimated and true composition of the samples, in a few iterations, independent of the initial guess. In order to test the fixed point iteration using real experimental data, a series of large sample PGNAA measurements were performed at ANL-W. These experiments are described and the measured spectra for the samples are presented. Then, the fixed point iteration is applied for these real experiments to find the composition of the samples. In all of the cases, except borated polyethylene, the composition of the large samples are found in a few iterations with errors less than +/-1.3%. The effectiveness of the fixed point iteration is thus demonstrated with many proof-of-principle measurements. While testing the fixed point iteration algorithm, published values of the source spectrum and relative detector efficiencies are used. The sensitivity of the fixed point iteration to source spectrum is investigated and it is shown that the estimated composition results are not very sensitive to the change in the source spectrum. The reason behind the slow convergence for the borated

  4. Triple point of e-deuterium as an accurate thermometric fixed point

    SciTech Connect

    Pavese, F.; McConville, G.T.

    1986-01-01

    The triple point of deuterium (18.7/sup 0/K) is the only possibility for excluding vapor pressure measurements in the definition of a temperature scale based on fixed points between 13.81 and 24.562/sup 0/K. This paper reports an investigation made at the Istituto di Metrologia and Mound Laboratory, using extremely pure deuterium directly sealed at the production plant into small metal cells. The large contamination by HD of commercially available gas, that cannot be accounted and corrected for due to its increase in handling, was found to be very stable with time after sealing in IMGC cells. HD contamination can be limited to less than 100 ppM in Monsanto cells, both with n-D/sub 2/ and e-D/sub 2/, when filled directly from the thermal diffusion column and sealed at the factory. e-D/sub 2/ requires a special deuterated catalyst. The triple point temperature of e-D/sub 2/ has been determined to be: T(NPL-IPTS-68) = 18.7011 +- 0.002/sup 0/K. 20 refs., 3 figs., 2 tabs.

  5. Area law for fixed points of rapidly mixing dissipative quantum systems

    SciTech Connect

    Brandão, Fernando G. S. L.; Cubitt, Toby S.; Lucia, Angelo; Michalakis, Spyridon; Perez-Garcia, David

    2015-10-15

    We prove an area law with a logarithmic correction for the mutual information for fixed points of local dissipative quantum system satisfying a rapid mixing condition, under either of the following assumptions: the fixed point is pure or the system is frustration free.

  6. A 64-bit orthorectification algorithm using fixed-point arithmetic

    NASA Astrophysics Data System (ADS)

    French, Joseph C.; Balster, Eric J.; Turri, William F.

    2013-10-01

    As the cost of imaging systems have decreased, the quality and size has increased. This dynamic has made the practicality of many aerial imaging applications achievable such as cost line monitoring and vegetation indexing. Orthorectification is required for many of these applications; however, it is also expensive, computationally. The computational cost is due to oating point operations and divisions inherent in the orthorecti cation process. Two novel algorithm modi cations are proposed which signi cantly reduce the computational cost. The rst modi cation uses xed-point arithmetic in place of the oating point operations. The second replaces the division with a multiplication of the inverse. The result in an increase of 2x of the throughput while remaining within 15% of a pixel size in position.

  7. A fixed point theorem for certain operator valued maps

    NASA Technical Reports Server (NTRS)

    Brown, D. R.; Omalley, M. J.

    1978-01-01

    In this paper, we develop a family of Neuberger-like results to find points z epsilon H satisfying L(z)z = z and P(z) = z. This family includes Neuberger's theorem and has the additional property that most of the sequences q sub n converge to idempotent elements of B sub 1(H).

  8. Parameter Space of Fixed Points of the Damped Driven Pendulum Susceptible to Control of Chaos Algorithms

    NASA Astrophysics Data System (ADS)

    Dittmore, Andrew; Trail, Collin; Olsen, Thomas; Wiener, Richard J.

    2003-11-01

    We have previously demonstrated the experimental control of chaos in a Modified Taylor-Couette system with hourglass geometry( Richard J. Wiener et al), Phys. Rev. Lett. 83, 2340 (1999).. Identifying fixed points susceptible to algorithms for the control of chaos is key. We seek to learn about this process in the accessible numerical model of the damped, driven pendulum. Following Baker(Gregory L. Baker, Am. J. Phys. 63), 832 (1995)., we seek points susceptible to the OGY(E. Ott, C. Grebogi, and J. A. Yorke, Phys. Rev. Lett. 64), 1196 (1990). algorithm. We automate the search for fixed points that are candidates for control. We present comparisons of the space of candidate fixed points with the bifurcation diagrams and Poincare sections of the system. We demonstrate control at fixed points which do not appear on the attractor. We also show that the control algorithm may be employed to shift the system between non-communicating branches of the attractor.

  9. Fixed point sensitivity analysis of interacting structured populations.

    PubMed

    Barabás, György; Meszéna, Géza; Ostling, Annette

    2014-03-01

    Sensitivity analysis of structured populations is a useful tool in population ecology. Historically, methodological development of sensitivity analysis has focused on the sensitivity of eigenvalues in linear matrix models, and on single populations. More recently there have been extensions to the sensitivity of nonlinear models, and to communities of interacting populations. Here we derive a fully general mathematical expression for the sensitivity of equilibrium abundances in communities of interacting structured populations. Our method yields the response of an arbitrary function of the stage class abundances to perturbations of any model parameters. As a demonstration, we apply this sensitivity analysis to a two-species model of ontogenetic niche shift where each species has two stage classes, juveniles and adults. In the context of this model, we demonstrate that our theory is quite robust to violating two of its technical assumptions: the assumption that the community is at a point equilibrium and the assumption of infinitesimally small parameter perturbations. Our results on the sensitivity of a community are also interpreted in a niche theoretical context: we determine how the niche of a structured population is composed of the niches of the individual states, and how the sensitivity of the community depends on niche segregation. PMID:24368160

  10. Correspondence between energy levels and evolution curves of fixed points in nonlinear Landau-Zener model

    NASA Astrophysics Data System (ADS)

    Liu, Xuan-Zuo; Tian, Dong-Ping; Chong, Bo

    2016-06-01

    Liu et al. [Phys. Rev. Lett. 90(17), 170404 (2003)] proved that the characters of transition probabilities in the adiabatic limit should be entirely determined by the topology of energy levels and the stability of fixed points in the classical Hamiltonian system, according to the adiabatic theorem. In the special case of nonlinear Landau-Zener model, we simplify their results to be that the properties of transition probabilities in the adiabatic limit should just be determined by the attributes of fixed points. It is because the topology of energy levels is governed by the behavior and symmetries of fixed points, and intuitively this fact is represented as a correspondence between energy levels and evolution curves of the fixed points which can be quantitatively described as the same complexity numbers.

  11. Analysis of fixed point FFT for Fourier domain optical coherence tomography systems.

    PubMed

    Ali, Murtaza; Parlapalli, Renuka; Magee, David P; Dasgupta, Udayan

    2009-01-01

    Optical coherence tomography (OCT) is a new imaging modality gaining popularity in the medical community. Its application includes ophthalmology, gastroenterology, dermatology etc. As the use of OCT increases, the need for portable, low power devices also increases. Digital signal processors (DSP) are well suited to meet the signal processing requirements of such a system. These processors usually operate on fixed precision. This paper analyzes the issues that a system implementer faces implementing signal processing algorithms on fixed point processor. Specifically, we show the effect of different fixed point precisions in the implementation of FFT on the sensitivity of Fourier domain OCT systems. PMID:19965018

  12. Extending the Nonlinear-Beam-Dynamics Concept of 1D Fixed Points to 2D Fixed Lines

    NASA Astrophysics Data System (ADS)

    Franchetti, G.; Schmidt, F.

    2015-06-01

    The origin of nonlinear dynamics traces back to the study of the dynamics of planets with the seminal work of Poincaré at the end of the nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his work he introduced a methodology fruitful for investigating the dynamical properties of complex systems, which led to the so-called "Poincaré surface of section," which allows one to capture the global dynamical properties of a system, characterized by fixed points and separatrices with respect to regular and chaotic motion. For two-dimensional phase space (one degree of freedom) this approach has been extremely useful and applied to particle accelerators for controlling their beam dynamics as of the second half of the twentieth century. We describe here an extension of the concept of 1D fixed points to fixed lines in two dimensions. These structures become the fundamental entities for characterizing the nonlinear motion in the four-dimensional phase space (two degrees of freedom).

  13. Extending the Nonlinear-Beam-Dynamics Concept of 1D Fixed Points to 2D Fixed Lines.

    PubMed

    Franchetti, G; Schmidt, F

    2015-06-12

    The origin of nonlinear dynamics traces back to the study of the dynamics of planets with the seminal work of Poincaré at the end of the nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his work he introduced a methodology fruitful for investigating the dynamical properties of complex systems, which led to the so-called "Poincaré surface of section," which allows one to capture the global dynamical properties of a system, characterized by fixed points and separatrices with respect to regular and chaotic motion. For two-dimensional phase space (one degree of freedom) this approach has been extremely useful and applied to particle accelerators for controlling their beam dynamics as of the second half of the twentieth century. We describe here an extension of the concept of 1D fixed points to fixed lines in two dimensions. These structures become the fundamental entities for characterizing the nonlinear motion in the four-dimensional phase space (two degrees of freedom). PMID:26196806

  14. Slip instability development and earthquake nucleation as a dynamical system's fixed-point attraction

    NASA Astrophysics Data System (ADS)

    Viesca, R. C.

    2014-12-01

    A fault's transition from slow creep to the propagation of an earthquake-generating dynamic rupture is thought to start as a quasi-static slip instability. Here we examine how such an instability develops on a sliding interface whose strength is governed by a slip rate- and state-dependent friction, where the state variable evolves according to the aging law. We find that the development occurs as the attraction of a dynamical system to a fixed point. The fixed points are such that the state of slip and the rate at which velocity diverges (and its spatial distribution) are known. The fixed points are independent of the manner of external forcing and the values of slip rate and state before the onset of instability. For a fault under uniform normal stress and frictional properties, the sole parameter that determines the fixed point (to within a translational invariance) is the ratio of the frictional parameters, a/b (where, for steady-state rate weakening, 0fixed points are asymptotically stable; however, stability is lost for a/b above that value. Increasing a/b above this critical value leads to a series of Hopf bifurcations. This cascade of bifurcations signals a quasi-periodic route to chaos, implying the existence of a second, larger, critical value of a/b (corresponding to the value at which the third Hopf bifurcation occurs), above which the slip instability may develop in a chaotic fashion. The fixed-point solutions, as well as the critical thresholds concerning their stability, depend on the configuration of slip (e.g., in/anti-plane or mixed-mode slip) and the elastic environment in which the interface is embedded (e.g., a slip surface between elastic half-spaces or one lying below and parallel to a free surface); solving for a fixed point reduces to the solution of an equivalent problem of an equilibrium slip-weakening fracture; and fixed-point stability is determined by linear stability analysis. Solutions of

  15. Infrared fixed point in SU(2) gauge theory with adjoint fermions

    SciTech Connect

    DeGrand, Thomas; Shamir, Yigal; Svetitsky, Benjamin

    2011-04-01

    We apply Schroedinger-functional techniques to the SU(2) lattice gauge theory with N{sub f}=2 flavors of fermions in the adjoint representation. Our use of hypercubic smearing enables us to work at stronger couplings than did previous studies, before encountering a critical point and a bulk phase boundary. Measurement of the running coupling constant gives evidence of an infrared fixed point g{sub *} where 1/g{sub *}{sup 2}=0.20(4)(3). At the fixed point, we find a mass anomalous dimension {gamma}{sub m}(g{sub *})=0.31(6).

  16. Dark energy as a fixed point of the Einstein Yang-Mills Higgs equations

    NASA Astrophysics Data System (ADS)

    Rinaldi, Massimiliano

    2015-10-01

    We study the Einstein Yang-Mills Higgs equations in the SO(3) representation on a isotropic and homogeneous flat Universe, in the presence of radiation and matter fluids. We map the equations of motion into an autonomous dynamical system of first-order differential equations and we find the equilibrium points. We show that there is only one stable fixed point that corresponds to an accelerated expanding Universe in the future. In the past, instead, there is an unstable fixed point that implies a stiff-matter domination. In between, we find three other unstable fixed points, corresponding, in chronological order, to radiation domination, to matter domination, and, finally, to a transition from decelerated expansion to accelerated expansion. We solve the system numerically and we confirm that there are smooth trajectories that correctly describe the evolution of the Universe, from a remote past dominated by radiation to a remote future dominated by dark energy, passing through a matter-dominated phase.

  17. Considerations for estimating remote operator dust exposure using fixed-point samples on continuous mining sections

    SciTech Connect

    Listak, J.M.; Goodman, G.V.R.; Jankowski, R.A.

    1999-07-01

    Respirable dust studies were conducted at several underground coal mining operations to evaluate and compare the dust measurements of fixed-point machine-mounted samples on a continuous miner and personal samples of the remote miner operator. Fixed-point sampling was conducted at the right rear corner of the continuous miner which corresponded to the traditional location of the operator's cab. Although it has been documented that higher concentrations of dust are present at the machine-mounted position, this work sought to determine whether a relationship exists between the concentrations at the fixed-point position and the dust levels experienced at the remote operator position and whether this relationship could be applied on an industry-wide basis. To achieve this objective, gravimetric samplers were used to collect respirable dust data on continuous miner sections. These samplers were placed at a fixed position at the cab location of the continuous mining machine and on or near the remote miner operator during the 1 shift/day sampling periods. Dust sampling took place at mines with a variety of geographic locations and in-mine conditions. The dust concentration data collected at each site and for each sampling period were reduced to ratios of fixed-point to operator concentration. The ratios were calculated to determine similarities, differences, and/or variability at the two positions. The data show that dust concentrations at the remote operator position were always lower than dust concentrations measured at the fixed-point continuous miner location. However, the ratios of fixed-point to remote operator dust levels showed little consistency from shift to shift or from operation to operation. The fact that these ratios are so variable may introduce some uncertainty into attempting to correlate dust exposures of the remote operator to dust levels measured on the continuous mining machine.

  18. Common Coupled Fixed Point Theorems for Two Hybrid Pairs of Mappings under φ-ψ Contraction

    PubMed Central

    Handa, Amrish

    2014-01-01

    We introduce the concept of (EA) property and occasional w-compatibility for hybrid pair F : X × X → 2X and f : X → X. We also introduce common (EA) property for two hybrid pairs F, G : X → 2X and f, g : X → X. We establish some common coupled fixed point theorems for two hybrid pairs of mappings under φ-ψ contraction on noncomplete metric spaces. An example is also given to validate our results. We improve, extend and generalize several known results. The results of this paper generalize the common fixed point theorems for hybrid pairs of mappings and essentially contain fixed point theorems for hybrid pair of mappings. PMID:27340688

  19. Entanglement storage by classical fixed points in the two-axis countertwisting model

    NASA Astrophysics Data System (ADS)

    Kajtoch, Dariusz; Pawłowski, Krzysztof; Witkowska, Emilia

    2016-02-01

    We analyze a scheme for storage of entanglement quantified by the quantum Fisher information in the two-axis countertwisting model. A characteristic feature of the two-axis countertwisting Hamiltonian is the existence of the four stable center and two unstable saddle fixed points in the mean-field phase portrait. The entangled state is generated dynamically from an initial spin-coherent state located around an unstable saddle fixed point. At an optimal moment of time the state is shifted to a position around the stable center fixed points by a single rotation, where its dynamics and properties are approximately frozen. We also discuss evolution with noise. In some cases the effect of noise turns out to be relatively weak, which is explained by parity conservation.

  20. Existence and data dependence of fixed points for multivalued operators on gauge spaces

    NASA Astrophysics Data System (ADS)

    Espínola, Rafael; Petrusel, Adrian

    2005-09-01

    The purpose of this note is to present some fixed point and data dependence theorems in complete gauge spaces and in hyperconvex metric spaces for the so-called Meir-Keeler multivalued operators and admissible multivalued a[alpha]-contractions. Our results extend and generalize several theorems of Espínola and Kirk [R. Espínola, W.A. Kirk, Set-valued contractions and fixed points, Nonlinear Anal. 54 (2003) 485-494] and Rus, Petrusel, and Sîntamarian [I.A. Rus, A. Petrusel, A. Sîntamarian, Data dependence of the fixed point set of some multivalued weakly Picard operators, Nonlinear Anal. 52 (2003) 1947-1959].

  1. Discovering and quantifying nontrivial fixed points in multi-field models

    NASA Astrophysics Data System (ADS)

    Eichhorn, A.; Helfer, T.; Mesterházy, D.; Scherer, M. M.

    2016-02-01

    We use the functional renormalization group and the ɛ -expansion concertedly to explore multicritical universality classes for coupled bigoplus _i O(N_i) vector-field models in three Euclidean dimensions. Exploiting the complementary strengths of these two methods we show how to make progress in theories with large numbers of interactions, and a large number of possible symmetry-breaking patterns. For the three- and four-field models we find a new fixed point that arises from the mutual interaction between different field sectors, and we establish the absence of infrared-stable fixed-point solutions for the regime of small N_i. Moreover, we explore these systems as toy models for theories that are both asymptotically safe and infrared complete. In particular, we show that these models exhibit complete renormalization group trajectories that begin and end at nontrivial fixed points.

  2. Normal form solutions of dynamical systems in the basin of attraction of their fixed points

    NASA Astrophysics Data System (ADS)

    Bountis, Tassos; Tsarouhas, George; Herman, Russell

    1998-10-01

    The normal form theory of Poincaré, Siegel and Arnol'd is applied to an analytically solvable Lotka-Volterra system in the plane, and a periodically forced, dissipative Duffing's equation with chaotic orbits in its 3-dimensional phase space. For the planar model, we determine exactly how the convergence region of normal forms about a nodal fixed point is limited by the presence of singularities of the solutions in the complex t-plane. Despite such limitations, however, we show, in the case of a periodically driven system, that normal forms can be used to obtain useful estimates of the basin of attraction of a stable fixed point of the Poincaré map, whose ``boundary'' is formed by the intersecting invariant manifolds of a second hyperbolic fixed point nearby.

  3. Entanglement entropy at infinite-randomness fixed points in higher dimensions.

    PubMed

    Lin, Yu-Cheng; Iglói, Ferenc; Rieger, Heiko

    2007-10-01

    The entanglement entropy of the two-dimensional random transverse Ising model is studied with a numerical implementation of the strong-disorder renormalization group. The asymptotic behavior of the entropy per surface area diverges at, and only at, the quantum phase transition that is governed by an infinite-randomness fixed point. Here we identify a double-logarithmic multiplicative correction to the area law for the entanglement entropy. This contrasts with the pure area law valid at the infinite-randomness fixed point in the diluted transverse Ising model in higher dimensions. PMID:17930713

  4. Parallel fixed point implementation of a radial basis function network in an FPGA.

    PubMed

    de Souza, Alisson C D; Fernandes, Marcelo A C

    2014-01-01

    This paper proposes a parallel fixed point radial basis function (RBF) artificial neural network (ANN), implemented in a field programmable gate array (FPGA) trained online with a least mean square (LMS) algorithm. The processing time and occupied area were analyzed for various fixed point formats. The problems of precision of the ANN response for nonlinear classification using the XOR gate and interpolation using the sine function were also analyzed in a hardware implementation. The entire project was developed using the System Generator platform (Xilinx), with a Virtex-6 xc6vcx240t-1ff1156 as the target FPGA. PMID:25268918

  5. Parallel Fixed Point Implementation of a Radial Basis Function Network in an FPGA

    PubMed Central

    de Souza, Alisson C. D.; Fernandes, Marcelo A. C.

    2014-01-01

    This paper proposes a parallel fixed point radial basis function (RBF) artificial neural network (ANN), implemented in a field programmable gate array (FPGA) trained online with a least mean square (LMS) algorithm. The processing time and occupied area were analyzed for various fixed point formats. The problems of precision of the ANN response for nonlinear classification using the XOR gate and interpolation using the sine function were also analyzed in a hardware implementation. The entire project was developed using the System Generator platform (Xilinx), with a Virtex-6 xc6vcx240t-1ff1156 as the target FPGA. PMID:25268918

  6. Chiral symmetry breaking in three-dimensional quantum electrodynamics as fixed point annihilation

    NASA Astrophysics Data System (ADS)

    Herbut, Igor F.

    2016-07-01

    Spontaneous chiral symmetry breaking in three-dimensional (d =3 ) quantum electrodynamics is understood as annihilation of an infrared-stable fixed point that describes the large-N conformal phase by another unstable fixed point at a critical number of fermions N =Nc. We discuss the root of universality of Nc in this picture, together with some features of the phase boundary in the (d ,N ) plane. In particular, it is shown that as d →4 , Nc→0 with a constant slope, our best estimate of which suggests that Nc=2.89 in d =3 .

  7. Fixing the fixed-point system—Applying Dynamic Renormalization Group to systems with long-range interactions

    NASA Astrophysics Data System (ADS)

    Katzav, Eytan

    2013-04-01

    In this paper, a mode of using the Dynamic Renormalization Group (DRG) method is suggested in order to cope with inconsistent results obtained when applying it to a continuous family of one-dimensional nonlocal models. The key observation is that the correct fixed-point dynamical system has to be identified during the analysis in order to account for all the relevant terms that are generated under renormalization. This is well established for static problems, however poorly implemented in dynamical ones. An application of this approach to a nonlocal extension of the Kardar-Parisi-Zhang equation resolves certain problems in one-dimension. Namely, obviously problematic predictions are eliminated and the existing exact analytic results are recovered.

  8. Fixed-point distributions of short-range Ising spin glasses on hierarchical lattices

    NASA Astrophysics Data System (ADS)

    Almeida, Sebastião T. O.; Nobre, Fernando D.

    2015-03-01

    Fixed-point distributions for the couplings of Ising spin glasses with nearest-neighbor interactions on hierarchical lattices are investigated numerically. Hierarchical lattices within the Migdal-Kadanoff family with fractal dimensions in the range 2.58 ≤D ≤7 , as well as a lattice of the Wheatstone-Bridge family with fractal dimension D ≈3.58 are considered. Three initial distributions for the couplings are analyzed, namely, the Gaussian, bimodal, and uniform ones. In all cases, after a few iterations of the renormalization-group procedure, the associated probability distributions approached universal fixed shapes. For hierarchical lattices of the Migdal-Kadanoff family, the fixed-point distributions were well fitted either by stretched exponentials, or by q -Gaussian distributions; both fittings recover the expected Gaussian limit as D →∞ . In the case of the Wheatstone-Bridge lattice, the best fit was found by means of a stretched-exponential distribution.

  9. Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities

    PubMed Central

    Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun

    2014-01-01

    Precise point positioning (PPP) technology is mostly implemented with an ambiguity-float solution. Its performance may be further improved by performing ambiguity-fixed resolution. Currently, the PPP integer ambiguity resolutions (IARs) are mainly based on GPS-only measurements. The integration of GPS and GLONASS can speed up the convergence and increase the accuracy of float ambiguity estimates, which contributes to enhancing the success rate and reliability of fixing ambiguities. This paper presents an approach of combined GPS/GLONASS PPP with fixed GPS ambiguities (GGPPP-FGA) in which GPS ambiguities are fixed into integers, while all GLONASS ambiguities are kept as float values. An improved minimum constellation method (MCM) is proposed to enhance the efficiency of GPS ambiguity fixing. Datasets from 20 globally distributed stations on two consecutive days are employed to investigate the performance of the GGPPP-FGA, including the positioning accuracy, convergence time and the time to first fix (TTFF). All datasets are processed for a time span of three hours in three scenarios, i.e., the GPS ambiguity-float solution, the GPS ambiguity-fixed resolution and the GGPPP-FGA resolution. The results indicate that the performance of the GPS ambiguity-fixed resolutions is significantly better than that of the GPS ambiguity-float solutions. In addition, the GGPPP-FGA improves the positioning accuracy by 38%, 25% and 44% and reduces the convergence time by 36%, 36% and 29% in the east, north and up coordinate components over the GPS-only ambiguity-fixed resolutions, respectively. Moreover, the TTFF is reduced by 27% after adding GLONASS observations. Wilcoxon rank sum tests and chi-square two-sample tests are made to examine the significance of the improvement on the positioning accuracy, convergence time and TTFF. PMID:25237901

  10. Fixed-point arithmetic for mobile devices: a fingerprinting verification case study

    NASA Astrophysics Data System (ADS)

    Moon, Yiu S.; Luk, Franklin T.; Ho, Ho C.; Tang, T. Y.; Chan, Kit C.; Leung, C. W.

    2002-12-01

    Mobile devices use embedded processors with low computing capabilities to reduce power consumption. Since floating-point arithmetic units are power hungry, computationally intensive jobs must be accomplished with either digital signal processors or hardware co-processors. In this paper, we propose to perform fixed-point arithmetic on an integer hardware unit. We illustrate the advantages of our approach by implementing fingerprint verification on mobile devices.

  11. Long-Term Stability of WC-C Peritectic Fixed Point

    NASA Astrophysics Data System (ADS)

    Khlevnoy, B. B.; Grigoryeva, I. A.

    2015-03-01

    The tungsten carbide-carbon peritectic (WC-C) melting transition is an attractive high-temperature fixed point with a temperature of . Earlier investigations showed high repeatability, small melting range, low sensitivity to impurities, and robustness of WC-C that makes it a prospective candidate for the highest fixed point of the temperature scale. This paper presents further study of the fixed point, namely the investigation of the long-term stability of the WC-C melting temperature. For this purpose, a new WC-C cell of the blackbody type was built using tungsten powder of 99.999 % purity. The stability of the cell was investigated during the cell aging for 50 h at the cell working temperature that tooks 140 melting/freezing cycles. The method of investigation was based on the comparison of the WC-C tested cell with a reference Re-C fixed-point cell that reduces an influence of the probable instability of a radiation thermometer. It was shown that after the aging period, the deviation of the WC-C cell melting temperature was with an uncertainty of.

  12. Fixed point analysis of a scalar theory with an external field

    SciTech Connect

    Bonanno, A.; Zappala, D.

    1997-09-01

    A momentum dependent projection of the Wegner-Hougton equation is derived for a scalar theory coupled to an external field. This formalism is useful to discuss the phase diagram of the theory. In particular we study some properties of the Gaussian fixed point. {copyright} {ital 1997} {ital The American Physical Society}

  13. 47 CFR 90.473 - Operation of internal transmitter control systems through licensed fixed control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation of internal transmitter control... Transmitter Control Internal Transmitter Control Systems § 90.473 Operation of internal transmitter control systems through licensed fixed control points. An internal transmitter control system may be...

  14. Bilateral Comparison of Mercury and Gallium Fixed-Point Cells Using Standard Platinum Resistance Thermometer

    NASA Astrophysics Data System (ADS)

    Bojkovski, J.; Veliki, T.; Zvizdić, D.; Drnovšek, J.

    2011-08-01

    The objective of project EURAMET 1127 (Bilateral comparison of triple point of mercury and melting point of gallium) in the field of thermometry is to compare realization of a triple point of mercury (-38.8344 °C) and melting point of gallium (29.7646 °C) between the Slovenian national laboratory MIRS/UL-FE/LMK and the Croatian national laboratory HMI/FSB-LPM using a long-stem 25 Ω standard platinum resistance thermometer (SPRT). MIRS/UL/FE-LMK participated in a number of intercomparisons on the level of EURAMET. On the other hand, the HMI/LPM-FSB laboratory recently acquired new fixed-point cells which had to be evaluated in the process of intercomparisons. A quartz-sheathed SPRT has been selected and calibrated at HMI/LPM-FSB at the triple point of mercury, the melting point of gallium, and the water triple point. A second set of measurements was made at MIRS/UL/FE-LMK. After its return, the SPRT was again recalibrated at HMI/LPM-FSB. In the comparison, the W value of the SPRT has been used. Results of the bilateral intercomparison confirmed that the new gallium cell of the HMI/LPM-FSB has a value that is within uncertainty limits of both laboratories that participated in the exercise, while the mercury cell experienced problems. After further research, a small leakage in the mercury fixed-point cell has been found.

  15. Liquidus slopes of impurities in ITS-90 fixed points from the mercury point to the copper point in the low concentration limit

    NASA Astrophysics Data System (ADS)

    Pearce, Jonathan V.; Gisby, John A.; Steur, Peter P. M.

    2016-08-01

    A knowledge of the effect of impurities at the level of parts per million on the freezing temperature of very pure metals is essential for realisation of ITS-90 fixed points. New information has become available for use with the thermodynamic modelling software MTDATA, permitting calculation of liquidus slopes, in the low concentration limit, of a wider range of binary alloy systems than was previously possible. In total, calculated values for 536 binary systems are given. In addition, new experimental determinations of phase diagrams, in the low impurity concentration limit, have recently appeared. All available data have been combined to provide a comprehensive set of liquidus slopes for impurities in ITS-90 metal fixed points. In total, liquidus slopes for 838 systems are tabulated for the fixed points Hg, Ga, In, Sn, Zn, Al, Ag, Au, and Cu. It is shown that the value of the liquidus slope as a function of impurity element atomic number can be approximated using a simple formula, and good qualitative agreement with the existing data is observed for the fixed points Al, Ag, Au and Cu, but curiously the formula is not applicable to the fixed points Hg, Ga, In, Sn, and Zn. Some discussion is made concerning the influence of oxygen on the liquidus slopes, and some calculations using MTDATA are discussed. The BIPM’s consultative committee for thermometry has long recognised that the sum of individual estimates method is the ideal approach for assessing uncertainties due to impurities, but the community has been largely powerless to use the model due to lack of data. Here, not only is data provided, but a simple model is given to enable known thermophysical data to be used directly to estimate impurity effects for a large fraction of the ITS-90 fixed points.

  16. Searching for fixed point combinators by using automated theorem proving: A preliminary report

    SciTech Connect

    Wos, L.; McCune, W.

    1988-09-01

    In this report, we establish that the use of an automated theorem- proving program to study deep questions from mathematics and logic is indeed an excellent move. Among such problems, we focus mainly on that concerning the construction of fixed point combinators---a problem considered by logicians to be significant and difficult to solve, and often computationally intensive and arduous. To be a fixed point combinator, THETA must satisfy the equation THETAx = x(THETAx) for all combinators x. The specific questions on which we focus most heavily ask, for each chosen set of combinators, whether a fixed point combinator can be constructed from the members of that set. For answering questions of this type, we present a new, sound, and efficient method, called the kernel method, which can be applied quite easily by hand and very easily by an automated theorem-proving program. For the application of the kernel method by a theorem-proving program, we illustrate the vital role that is played by both paramodulation and demodulation---two of the powerful features frequently offered by an automated theorem-proving program for treating equality as if it is ''understood.'' We also state a conjecture that, if proved, establishes the completeness of the kernel method. From what we can ascertain, this method---which relies on the introduced concepts of kernel and superkernel---offers the first systematic approach for searching for fixed point combinators. We successfully apply the new kernel method to various sets of combinators and, for the set consisting of the combinators B and W, construct an infinite set of fixed point combinators such that no two of the combinators are equal even in the presence of extensionality---a law that asserts that two combinators are equal if they behave the same. 18 refs.

  17. Device-independent test of causal order and relations to fixed-points

    NASA Astrophysics Data System (ADS)

    Baumeler, Ämin; Wolf, Stefan

    2016-03-01

    Bell non-local correlations cannot be naturally explained in a fixed causal structure. This serves as a motivation for considering models where no global assumption is made beyond logical consistency. The assumption of a fixed causal order between a set of parties, together with free randomness, implies device-independent inequalities—just as the assumption of locality does. It is known that local validity of quantum theory is consistent with violating such inequalities. Moreover, for three parties or more, even the (stronger) assumption of local classical probability theory plus logical consistency allows for violating causal inequalities. Here, we show that a classical environment (with which the parties interact), possibly containing loops, is logically consistent if and only if whatever the involved parties do, there is exactly one fixed-point, the latter being representable as a mixture of deterministic fixed-points. We further show that the non-causal view allows for a model of computation strictly more powerful than computation in a world of fixed causal orders.

  18. Fully developed isotropic turbulence: Nonperturbative renormalization group formalism and fixed-point solution

    NASA Astrophysics Data System (ADS)

    Canet, Léonie; Delamotte, Bertrand; Wschebor, Nicolás

    2016-06-01

    We investigate the regime of fully developed homogeneous and isotropic turbulence of the Navier-Stokes (NS) equation in the presence of a stochastic forcing, using the nonperturbative (functional) renormalization group (NPRG). Within a simple approximation based on symmetries, we obtain the fixed-point solution of the NPRG flow equations that corresponds to fully developed turbulence both in d =2 and 3 dimensions. Deviations to the dimensional scalings (Kolmogorov in d =3 or Kraichnan-Batchelor in d =2 ) are found for the two-point functions. To further analyze these deviations, we derive exact flow equations in the large wave-number limit, and show that the fixed point does not entail the usual scale invariance, thereby identifying the mechanism for the emergence of intermittency within the NPRG framework. The purpose of this work is to provide a detailed basis for NPRG studies of NS turbulence; the determination of the ensuing intermittency exponents is left for future work.

  19. A Fixed-Point Phase Lock Loop in a Software Defined Radio

    NASA Astrophysics Data System (ADS)

    Johannes, Michael T.

    2002-09-01

    A software defined radio is a much more flexible platform than traditional, hardware implemented radios, By implementing radio functions in software, and putting those functions on a Field Programmable Gate Array (FPGA) chip, users will have the ability to download mission specific radio capabilities. This thesis examines a fundamental piece of the receiver, the Phase-Lock Loop (PLL), simulates a software PLL, and investigates the effects of fixed-point versus floating point mathematics required for an FPGA based PLL. With a fixed-point PLL simulator, figures of merit such as lock-time, lock range, and pull-in range are determined% for typical signal-to-noise ratio (SNR) levels.

  20. Bilateral Comparison Between NPL and INMETRO Using a High-Temperature Fixed Point of Unknown Temperature

    NASA Astrophysics Data System (ADS)

    Machin, G.; Teixeira, R.; Lu, X.; Lowe, D.

    2015-03-01

    There is an on-going requirement to perform scale comparisons above the silver point with reduced uncertainties. Previous comparisons have been performed with high stability lamps or radiation thermometers, neither of which were able to achieve the required uncertainty. Ideally a set of driftless unknown temperature fixed points would be used to compare scales, but up to now such artifacts did not exist. This study develops blind high-temperature comparison artifacts based on doped versions of the high-temperature fixed point (HTFP) Ni-C (nominal temperature ). At INMETRO three HTFP blackbodies were constructed, one of pure Ni-C and two doped with different levels of Cu. To ascertain the effect of doping on the transition temperature, the cells were compared to the reference pure Ni-C cell. The doped cells were then transported to NPL and their temperatures measured. NPL was not informed of the INMETRO result ensuring that the measurements remained blind. The cells were then returned to INMETRO and re-measured to establish their stability. The temperatures measured at INMETRO and NPL were then compared and showed very good equivalence of the scale at the fixed-point temperatures. The results of the comparison of the NPL and INMETRO temperature scale, at nominally , are reported, along with evidence of the stability of the artifacts determined from repeat measurements. These promising results indicate that it may be possible to make HTFPs with altered temperatures which are stable enough to serve as comparison artifacts.

  1. Tympanic thermometer performance validation by use of a body-temperature fixed point blackbody

    NASA Astrophysics Data System (ADS)

    Machin, Graham; Simpson, Robert

    2003-04-01

    The use of infrared tympanic thermometers within the medical community (and more generically in the public domain) has recently grown rapidly, displacing more traditional forms of thermometry such as mercury-in-glass. Besides the obvious health concerns over mercury the increase in the use of tympanic thermometers is related to a number of factors such as their speed and relatively non-invasive method of operation. The calibration and testing of such devices is covered by a number of international standards (ASTM1, prEN2, JIS3) which specify the design of calibration blackbodies. However these calibration sources are impractical for day-to-day in-situ validation purposes. In addition several studies (e.g. Modell et al4, Craig et al5) have thrown doubt on the accuracy of tympanic thermometers in clinical use. With this in mind the NPL is developing a practical, portable and robust primary reference fixed point source for tympanic thermometer validation. The aim of this simple device is to give the clinician a rapid way of validating the performance of their tympanic thermometer, enabling the detection of mal-functioning thermometers and giving confidence in the measurement to the clinician (and patient!) at point of use. The reference fixed point operates at a temperature of 36.3 °C (97.3 °F) with a repeatability of approximately +/- 20 mK. The fixed-point design has taken into consideration the optical characteristics of tympanic thermometers enabling wide-angled field of view devices to be successfully tested. The overall uncertainty of the device is estimated to be is less than 0.1°C. The paper gives a description of the fixed point, its design and construction as well as the results to date of validation tests.

  2. The fixed point formulation for large sample PGNAA—Part 1: theory

    NASA Astrophysics Data System (ADS)

    Holloway, J. P.; Akkurt, H.

    2004-04-01

    The determination of large sample composition via prompt gamma measurements is examined as a non-linear inverse problem. We show that this non-linear problem can be formulated as a fixed point problem that always has a physically meaningful solution, even in the presence of significant contributions to photopeak area from gammas emitted by the surroundings. The formulation involves only ratios of measured photopeak areas, and, separately, ratios of modeled photopeak areas. It therefore does not require the absolute comparison of measured or modeled quantities. The proof of the existence of meaningful solutions relies on very simple and natural hypotheses of positivity and continuity. The natural fixed point iteration is examined, and certain physical limits where its global convergence can be guaranteed are examined. Several computational examples are presented.

  3. The fixed point formulation for large sample PGNAA—Part 2: experimental demonstration

    NASA Astrophysics Data System (ADS)

    Akkurt, H.; Holloway, J. P.; Smith, L. E.

    2004-04-01

    We present composition estimation results using fixed point iteration compared to the true composition of sample for prompt gamma measurements. The analysis showed that the fixed point iteration algorithm converges very rapidly to true composition of the sample independent of the initial guess when there is no significant background contribution. Even in the presence of significant background contribution, the true composition of the sample was estimated with high precision but with slower convergence. Although approximate data for neutron source spectrum and relative efficiency of the detector was used for analysis, the results showed that the method is not very sensitive to the details of the model since it is based on ratios. Despite the approximate data used for computations, the composition estimation results are in excellent agreement with chemical analysis.

  4. Infrared fixed point of the top Yukawa coupling in split supersymmetry

    SciTech Connect

    Huitu, Katri; Laamanen, Jari; Roy, Probir; Roy, Sourov

    2005-09-01

    The severe constraints imposed on the parameter space of the minimal split supersymmetry model by the infrared fixed point solution of the top Yukawa coupling Y{sub t} are studied in detail in terms of the value of the top-quark mass measured at the Tevatron together with the lower bound on the lightest Higgs mass established by LEP. The dependence of the Higgsino mass parameter {mu}, the gaugino coupling strengths g-tilde{sub u,d}, g-tilde{sub u,d}{sup '} and of the Higgs quartic self-coupling {lambda} on the value of Y{sub t} in the vicinity of the Landau pole is discussed. A few interesting features emerge, though the model is found to be disfavored within the infrared fixed point scenario because of the need to have several unnatural cancellations at work on account of the requirement of a low upper bound on tan{beta}.

  5. New Experimental Technique for the Study of Phase Transition Evolution in Fixed-Point Cells

    NASA Astrophysics Data System (ADS)

    Nemeth, T.; Nemeth, S.; Turzo-Andras, E.

    2015-08-01

    A new advanced technique was developed at the Hungarian Metrological Institute (MKEH), devoted to optimizing the realization of the International Temperature Scale ITS-90. The work was performed within the framework of the European project "Novel techniques for traceable temperature dissemination." The paper is devoted to describing this new measurement technique and its setup. The time evolution of the solid fraction and melt fraction along the phase transformation has been followed, using a technique based on the difference of the electrical conductivity between the solid and liquid phases of the metal. The measurement technique provides electrical signals, which are suitable for improving the quality of the freezing plateaus realized in the case of different fixed-point realizations, covering the temperature range from to . The ideal section of the freezing plateau can be maintained by ensuring a continuous flow of mass and energy of the fixed-point substance in the axial direction. The intervention is achieved by modifying the temperatures of the different zones of the furnace controller with more degrees, with the aid of developed intervening devices. Recent developments permit the selection of the ideal section of a freezing plateau and, what is more, the increase of this plateau section to practically unlimited for all metal fixed points.

  6. Fixed points of the SRG evolution and the on-shell limit of the nuclear force

    NASA Astrophysics Data System (ADS)

    Arriola, E. Ruiz; Szpigel, S.; Timóteo, V. S.

    2016-08-01

    We study the infrared limit of the similarity renormalization group (SRG) using a simple toy model for the nuclear force aiming to investigate the fixed points of the SRG evolution with both the Wilson and the Wegner generators. We show how a fully diagonal interaction at the similarity cutoff λ → 0 may be obtained from the eigenvalues of the Hamiltonian and quantify the diagonalness by means of operator norms. While the fixed points for both generators are equivalent when no bound-states are allowed by the interaction, the differences arising from the presence of the Deuteron bound-state can be disentangled very clearly by analyzing the evolved interactions in the infrared limit λ → 0 on a finite momentum grid. Another issue we investigate is the location on the diagonal of the Hamiltonian in momentum-space where the SRG evolution places the Deuteron bound-state eigenvalue once it reaches the fixed point. This finite momentum grid setup provides an alternative derivation of the celebrated trace identities, as a by product. The different effects due to either the Wilson or the Wegner generators on the binding energies of A = 2 , 3 , 4 systems are investigated and related to the occurrence of a Tjon-line which emerges as the minimum of an avoided crossing between Eα = 4Et - 3Ed and Eα = 2Et. All infrared features of the flow equations are illustrated using the toy model for the two-nucleon S-waves.

  7. A new constrained fixed-point algorithm for ordering independent components

    NASA Astrophysics Data System (ADS)

    Zhang, Hongjuan; Guo, Chonghui; Shi, Zhenwei; Feng, Enmin

    2008-10-01

    Independent component analysis (ICA) aims to recover a set of unknown mutually independent components (ICs) from their observed mixtures without knowledge of the mixing coefficients. In the classical ICA model there exists ICs' indeterminacy on permutation and dilation. Constrained ICA is one of methods for solving this problem through introducing constraints into the classical ICA model. In this paper we first present a new constrained ICA model which composed of three parts: a maximum likelihood criterion as an objective function, statistical measures as inequality constraints and the normalization of demixing matrix as equality constraints. Next, we incorporate the new fixed-point (newFP) algorithm into this constrained ICA model to construct a new constrained fixed-point algorithm. Computation simulations on synthesized signals and speech signals demonstrate that this combination both can eliminate ICs' indeterminacy to a certain extent, and can provide better performance. Moreover, comparison results with the existing algorithm verify the efficiency of our new algorithm furthermore, and show that it is more simple to implement than the existing algorithm due to its advantage of not using the learning rate. Finally, this new algorithm is also applied for the real-world fetal ECG data, experiment results further indicate the efficiency of the new constrained fixed-point algorithm.

  8. Study on the Impurity Effect in the Realization of Silver Fixed Point

    NASA Astrophysics Data System (ADS)

    Tsai, S. F.

    2016-03-01

    The application of a thermal analysis model to estimate the temperature depression from the ideal fixed-point temperature is important, especially when the chemical analysis of the sample in a cell is insufficient or the cell might have been contaminated during fabrication. This study extends previous work, on thermal analysis with the tin point, to an investigation of the impurity dependence of the silver-point temperature. Close agreement was found between the temperature depression (-0.36 mK) inferred from the thermal analysis of the measured fixed-point plateau and the temperature depression (-0.32 mK) inferred using the sum of individual estimates (SIE) method with an impurity analysis based on glow discharge mass spectrometry. Additionally, the results of the thermal analysis manifest no significant dependence on the rate of solidification, and the scatter of observed gradients was within 0.36 mK among five plateaux with different temperature settings of the furnace. Although the results support the application of both the SIE method and thermal analysis for the silver point, further experiments with cell-to-cell comparisons linked to thermal analysis, a study of the thermometer-furnace systematic effects, the oxygen effect, and the locus of the freezing plateau should be investigated to reach a firm conclusion.

  9. Nonthermal fixed points: effective weak coupling for strongly correlated systems far from equilibrium.

    PubMed

    Berges, Jürgen; Rothkopf, Alexander; Schmidt, Jonas

    2008-07-25

    Strongly correlated systems far from equilibrium can exhibit scaling solutions with a dynamically generated weak coupling. We show this by investigating isolated systems described by relativistic quantum field theories for initial conditions leading to nonequilibrium instabilities, such as parametric resonance or spinodal decomposition. The nonthermal fixed points prevent fast thermalization if classical-statistical fluctuations dominate over quantum fluctuations. We comment on the possible significance of these results for the heating of the early Universe after inflation and the question of fast thermalization in heavy-ion collision experiments. PMID:18764319

  10. Infinite-randomness fixed points for chains of non-Abelian quasiparticles.

    PubMed

    Bonesteel, N E; Yang, Kun

    2007-10-01

    One-dimensional chains of non-Abelian quasiparticles described by SU(2)k Chern-Simons-Witten theory can enter random singlet phases analogous to that of a random chain of ordinary spin-1/2 particles (corresponding to k-->infinity). For k=2 this phase provides a random singlet description of the infinite-randomness fixed point of the critical transverse field Ising model. The entanglement entropy of a region of size L in these phases scales as S(L) approximately lnd/3 log(2)L for large L, where d is the quantum dimension of the particles. PMID:17930652

  11. Infinite randomness fixed point of the superconductor-metal quantum phase transition.

    PubMed

    Del Maestro, Adrian; Rosenow, Bernd; Müller, Markus; Sachdev, Subir

    2008-07-18

    We examine the influence of quenched disorder on the superconductor-metal transition, as described by a theory of overdamped Cooper pairs which repel each other. The self-consistent pairing eigenmodes of a quasi-one-dimensional wire are determined numerically. Our results support the recent proposal by Hoyos et al. [Phys. Rev. Lett. 99, 230601 (2007)10.1103/PhysRevLett.99.230601] that the transition is characterized by the same strong-disorder fixed point describing the onset of ferromagnetism in the random quantum Ising chain in a transverse field. PMID:18764263

  12. Unitarity violation at the Wilson-Fisher fixed point in 4 -ɛ dimensions

    NASA Astrophysics Data System (ADS)

    Hogervorst, Matthijs; Rychkov, Slava; van Rees, Balt C.

    2016-06-01

    We consider the continuation of free and interacting scalar field theory to noninteger spacetime dimension d . We find that the correlation functions in these theories are necessarily incompatible with unitarity (or with reflection positivity in Euclidean signature). In particular, the theories contain negative-norm states unless d is a positive integer. These negative-norm states can be obtained via the operator product expansion from simple positive-norm operators, and are therefore an integral part of the theory. At the Wilson-Fisher fixed point the nonunitarity leads to the existence of complex anomalous dimensions. We demonstrate that they appear already at leading order in the epsilon expansion.

  13. Infinite Randomness Fixed Point of the Superconductor-Metal Quantum Phase Transition

    NASA Astrophysics Data System (ADS)

    Del Maestro, Adrian; Rosenow, Bernd; Müller, Markus; Sachdev, Subir

    2008-07-01

    We examine the influence of quenched disorder on the superconductor-metal transition, as described by a theory of overdamped Cooper pairs which repel each other. The self-consistent pairing eigenmodes of a quasi-one-dimensional wire are determined numerically. Our results support the recent proposal by Hoyos et al. [Phys. Rev. Lett. 99, 230601 (2007)PRLTAO0031-900710.1103/PhysRevLett.99.230601] that the transition is characterized by the same strong-disorder fixed point describing the onset of ferromagnetism in the random quantum Ising chain in a transverse field.

  14. Uncertainty due to non-linearity in radiation thermometers calibrated by multiple fixed points

    SciTech Connect

    Yamaguchi, Y.; Yamada, Y.

    2013-09-11

    A new method to estimate the uncertainty due to non-linearity is described on the n= 3 scheme basis. The expression of uncertainty is mathematically derived applying the random walk method. The expression is simple and requires only the temperatures of the fixed points and a relative uncertainty value for each flux-doubling derived from the non-linearity measurement. We also present an example of the method, in which the uncertainty of temperature measurement by a radiation thermometer is calculated on the basis of non-linearity measurement.

  15. Isotopic effects in the neon fixed point: uncertainty of the calibration data correction

    NASA Astrophysics Data System (ADS)

    Steur, Peter P. M.; Pavese, Franco; Fellmuth, Bernd; Hermier, Yves; Hill, Kenneth D.; Seog Kim, Jin; Lipinski, Leszek; Nagao, Keisuke; Nakano, Tohru; Peruzzi, Andrea; Sparasci, Fernando; Szmyrka-Grzebyk, Anna; Tamura, Osamu; Tew, Weston L.; Valkiers, Staf; van Geel, Jan

    2015-02-01

    The neon triple point is one of the defining fixed points of the International Temperature Scale of 1990 (ITS-90). Although recognizing that natural neon is a mixture of isotopes, the ITS-90 definition only states that the neon should be of ‘natural isotopic composition’, without any further requirements. A preliminary study in 2005 indicated that most of the observed variability in the realized neon triple point temperatures within a range of about 0.5 mK can be attributed to the variability in isotopic composition among different samples of ‘natural’ neon. Based on the results of an International Project (EUROMET Project No. 770), the Consultative Committee for Thermometry decided to improve the realization of the neon fixed point by assigning the ITS-90 temperature value 24.5561 K to neon with the isotopic composition recommended by IUPAC, accompanied by a quadratic equation to take the deviations from the reference composition into account. In this paper, the uncertainties of the equation are discussed and an uncertainty budget is presented. The resulting standard uncertainty due to the isotopic effect (k = 1) after correction of the calibration data is reduced to (4 to 40) μK when using neon of ‘natural’ isotopic composition or to 30 μK when using 20Ne. For comparison, an uncertainty component of 0.15 mK should be included in the uncertainty budget for the neon triple point if the isotopic composition is unknown, i.e. whenever the correction cannot be applied.

  16. Finiteness of fixed equilibrium configurations of point vortices in the plane with a background flow

    NASA Astrophysics Data System (ADS)

    Cheung, Pak-Leong; Ng, Tuen Wai

    2014-10-01

    For a dynamic system consisting of n point vortices in an ideal plane fluid with a steady, incompressible and irrotational background flow, a more physically significant definition of a fixed equilibrium configuration is suggested. Under this new definition, if the complex polynomial w that determines the aforesaid background flow is non-constant, we have found an attainable generic upper bound \\frac{(m+n-1)!}{(m-1)!\\,n_1!\\cdots n_{i_0}!} for the number of fixed equilibrium configurations. Here, m = deg w, i0 is the number of species, and each ni is the number of vortices in a species. We transform the rational function system arising from fixed equilibria into a polynomial system, whose form is good enough to apply the BKK theory (named after Bernshtein (1975 Funct. Anal. Appl. 9 183-5), Khovanskii (1978 Funct. Anal. Appl. 12 38-46) and Kushnirenko (1976 Funct. Anal. Appl. 10 233-5)) to show the finiteness of its number of solutions. Having this finiteness, the required bound follows from Bézout's theorem or the BKK root count by Li and Wang (1996 Math. Comput. 65 1477-84).

  17. On Essential Fixed Points of Compact Mappings on Arbitrary Absolute Neighborhood Retracts and Their Application to Multivalued Fractals

    NASA Astrophysics Data System (ADS)

    Andres, Jan; Górniewicz, Lech

    The existence of essential fixed points is proved for compact self-maps of arbitrary absolute neighborhood retracts, provided the generalized Lefschetz number is nontrivial and the topological dimension of a fixed point set is equal to zero. Furthermore, continuous self-maps of some special compact absolute neighborhood retracts, whose Lefschetz number is nontrivial, are shown to possess pseudo-essential fixed points even without the zero dimensionality assumption. Both results are applied to the existence of essential and pseudo-essential multivalued fractals. An illustrative example of this application is supplied.

  18. Development of a new radiometer for the thermodynamic measurement of high temperature fixed points

    NASA Astrophysics Data System (ADS)

    Dury, M. R.; Goodman, T. M.; Lowe, D. H.; Machin, G.; Woolliams, E. R.

    2013-09-01

    The National Physical Laboratory (NPL) has developed a new radiometer to measure the thermodynamic melting point temperatures of high temperature fixed points with ultra-low uncertainties. In comparison with the NPL's Absolute Radiation Thermometer (ART), the "THermodynamic Optical Radiometer" (THOR) is more portable and compact, with a much lower size-of-source effect and improved performance in other parameters such as temperature sensitivity. It has been designed for calibration as a whole instrument via the radiance method, removing the need to calibrate the individual subcomponents, as required by ART, and thereby reducing uncertainties. In addition, the calibration approach has been improved through a new integrating sphere that has been designed to have greater uniformity.

  19. Non-thermal fixed points and solitons in a one-dimensional Bose gas

    NASA Astrophysics Data System (ADS)

    Schmidt, Maximilian; Erne, Sebastian; Nowak, Boris; Sexty, Dénes; Gasenzer, Thomas

    2012-07-01

    Single-particle momentum spectra for a dynamically evolving one-dimensional Bose gas are analysed in the semi-classical wave limit. Representing one of the simplest correlation functions, these provide information on a possible universal scaling behaviour. Motivated by the previously discovered connection between (quasi-) topological field configurations, strong wave turbulence and non-thermal fixed points of quantum field dynamics, soliton formation is studied with respect to the appearance of transient power-law spectra. A random-soliton model is developed for describing the spectra analytically, and the analogies and differences between the emerging power laws and those found in a field theory approach to strong wave turbulence are discussed. The results open a new perspective on solitary wave dynamics from the point of view of critical phenomena far from thermal equilibrium and the possibility of studying this dynamics by experiment without the need for detecting solitons in situ.

  20. Development of a new radiometer for the thermodynamic measurement of high temperature fixed points

    SciTech Connect

    Dury, M. R.; Goodman, T. M.; Lowe, D. H.; Machin, G.; Woolliams, E. R.

    2013-09-11

    The National Physical Laboratory (NPL) has developed a new radiometer to measure the thermodynamic melting point temperatures of high temperature fixed points with ultra-low uncertainties. In comparison with the NPL's Absolute Radiation Thermometer (ART), the 'THermodynamic Optical Radiometer' (THOR) is more portable and compact, with a much lower size-of-source effect and improved performance in other parameters such as temperature sensitivity. It has been designed for calibration as a whole instrument via the radiance method, removing the need to calibrate the individual subcomponents, as required by ART, and thereby reducing uncertainties. In addition, the calibration approach has been improved through a new integrating sphere that has been designed to have greater uniformity.

  1. Influence of Impurities and Filling Protocol on the Aluminum Fixed Point

    NASA Astrophysics Data System (ADS)

    Renaot, E.; Valin, M. H.; Elgourdou, M.

    2008-06-01

    To improve the uncertainty of the aluminum fixed point, a study was launched by LNE-INM/CNAM in the framework of the EUROMET Project 732 “Toward more accurate temperature fixed points” (Coordinating laboratory: LNE-INM/CNAM, 17 partner countries). A new open cell was filled with aluminum of 99.99995% purity. A French laboratory carried out elemental analysis of the sample using glow discharge-mass spectrometry (GD-MS). The values of the equilibrium distribution coefficient k and of the derivative {δ T_{{l}}/δ ci_{{l}}} of the temperature of the liquidus line with respect to the concentration of impurity i will be obtained through collaboration with a French physical and chemical laboratory. In the past, some aluminum cells were opened after several melts and freezes. The aluminum ingot was sticking to the graphite crucible, indicating that physicochemical reactions had likely occurred between Al and C. To avoid this reaction, an effort was made to draw benefit from the Al2O3 film that appears immediately on the surface of the aluminum ingot when it is exposed to oxygen. The open aluminum cell was tested in different furnaces and with different thermal insulator arrangements inside the fixed-point assembly. The observed drifts of the plateaux were always larger than the expected values. The cell was opened to inspect the aluminum ingot. The ingot was extracted easily, since no sticking to the crucible had occurred. The aluminum showed a very bright surface, but the presence of many “craters” throughout the thickness of the ingot was surprising. In some cases, the thermometer well was even apparent.

  2. Automatic Contour Detection Using a "Fixed-Point Hachimura-Kuwahara Filter" for SPECT Attenuation Correction.

    PubMed

    Minato, K; Tang, Y N; Bennett, G W; Brill, A

    1987-01-01

    Attenuation correction for single-photon emission computed tomography (SPECT) usually assumes a uniform attenuation distribution within the body surface contour. Previous methods to estimate this contour have used thresholding of a reconstructed section image. This method is often very sensitive to the selection of a threshold value, especially for nonuniform activity distributions within the body. We have proposed the "fixed-point Hachimura-Kuwahara filter" to extract contour primitives from SPECT images. The Hachimura-Kuwahara filter, which preserves edges but smoothes nonedge regions, is applied repeatedly to identify the invariant set-the fixed-point image-which is unchanged by this nonlinear, two-dimensional filtering operation. This image usually becomes a piecewise constant array. In order to detect the contour, the tracing algorithm based on the minimum distance connection criterion is applied to the extracted contour primitives. This procedure does not require choice of a threshold value in determining the contour. SPECT data from a water-filled elliptical phantom containing three sources was obtained and scattered projections were reconstructed. The automatic edge detection procedure was applied to the scattered window reconstruction, resulting in a reasonable outline of the phantom. PMID:18230438

  3. An optimized treatment for algorithmic differentiation of an important glaciological fixed-point problem

    NASA Astrophysics Data System (ADS)

    Goldberg, Daniel N.; Krishna Narayanan, Sri Hari; Hascoet, Laurent; Utke, Jean

    2016-05-01

    We apply an optimized method to the adjoint generation of a time-evolving land ice model through algorithmic differentiation (AD). The optimization involves a special treatment of the fixed-point iteration required to solve the nonlinear stress balance, which differs from a straightforward application of AD software, and leads to smaller memory requirements and in some cases shorter computation times of the adjoint. The optimization is done via implementation of the algorithm of Christianson (1994) for reverse accumulation of fixed-point problems, with the AD tool OpenAD. For test problems, the optimized adjoint is shown to have far lower memory requirements, potentially enabling larger problem sizes on memory-limited machines. In the case of the land ice model, implementation of the algorithm allows further optimization by having the adjoint model solve a sequence of linear systems with identical (as opposed to varying) matrices, greatly improving performance. The methods introduced here will be of value to other efforts applying AD tools to ice models, particularly ones which solve a hybrid shallow ice/shallow shelf approximation to the Stokes equations.

  4. Optimization of the thermogauge furnace for realizing high temperature fixed points

    SciTech Connect

    Wang, T.; Dong, W.; Liu, F.

    2013-09-11

    The thermogauge furnace was commonly used in many NMIs as a blackbody source for calibration of the radiation thermometer. It can also be used for realizing the high temperature fixed point(HTFP). According to our experience, when realizing HTFP we need the furnace provide relative good temperature uniformity to avoid the possible damage to the HTFP. To improve temperature uniformity in the furnace, the furnace tube was machined near the tube ends with a help of a simulation analysis by 'ansys workbench'. Temperature distributions before and after optimization were measured and compared at 1300 °C, 1700°C, 2500 °C, which roughly correspond to Co-C(1324 °C), Pt-C(1738 °C) and Re-C(2474 °C), respectively. The results clearly indicate that through machining the tube the temperature uniformity of the Thermogage furnace can be remarkably improved. A Pt-C high temperature fixed point was realized in the modified Thermogauge furnace subsequently, the plateaus were compared with what obtained using old heater, and the results were presented in this paper.

  5. Use of Eutectic Fixed Points to Characterize a Spectrometer for Earth Observations

    NASA Astrophysics Data System (ADS)

    Salim, Saber G. R.; Fox, Nigel P.; Woolliams, Emma R.; Winkler, Rainer; Pegrum, Heather M.; Sun, Tong; Grattan, Ken T. V.

    2007-12-01

    A small palm-sized, reference spectrometer, mounted on a remote-controlled model helicopter is being developed and tested by the National Physical Laboratory (NPL) in conjunction with City University, London. The developed system will be used as a key element for field vicarious calibration of optical earth observation systems in the visible-near infrared (VNIR) region. The spectrometer is hand held, low weight, and uses a photodiode array. It has good stray light rejection and wide spectral coverage, allowing simultaneous measurements from 400 to 900 nm. The spectrometer is traceable to NPL’s primary standard cryogenic radiometer via a high-temperature metal-carbon eutectic fixed-point blackbody. Once the fixed-point temperature has been determined (using filter radiometry), the eutectic provides a high emissivity and high stability source of known spectral radiance over the emitted spectral range. All wavelength channels of the spectrometer can be calibrated simultaneously using the eutectic transition without the need for additional instrumentation. The spectrometer itself has been characterized for stray light performance and wavelength accuracy. Its long-term and transportation stability has been proven in an experiment that determined the “World’s Bluest Sky”—a process that involved 56 flights, covering 100,000 km in 72 days. This vicarious calibration methodology using a eutectic standard is presented alongside the preliminary results of an evaluation study of the spectrometer characteristics.

  6. Stability of cobalt-carbon high temperature fixed points doped with iron and platinum

    NASA Astrophysics Data System (ADS)

    Kňazovická, L.; Lowe, D.; Machin, G.; Davies, H.; Rani, A.

    2015-04-01

    High temperature fixed points (HTFPs) are stable and repeatable and make comparison of temperature scales possible at a level of uncertainty not previously possible. However, they potentially lack objectivity if the fixed-point temperature is known. Five HTFPs were constructed, one pure Co-C, two Co-C doped with Fe and two Co-C doped with Pt of differing concentrations. The candidate dopants were identified through thermochemical modelling as likely to give maximum temperature shift with minimum increase in melting range. The temperature differences of the doped systems from the pure system were determined and it was found that the addition of Fe depressed the melting temperature and the addition of Pt elevated the melting temperature, qualitatively in line with the thermochemical modelling. The higher concentration doped HTFPs were then aged for approximately 100 h with continuous melting-freezing cycles and the difference to the undoped Co-C HTFP remeasured. These differences were found to agree with those of the unaged results within the measurement uncertainties, confirming artefact stability. It is clear that the doping of HTFPs is a powerful way of constructing stable and reliable high temperature scale comparison artefacts of unknown temperature.

  7. Stability of a cubic fixed point in three dimensions: Critical exponents for generic N

    NASA Astrophysics Data System (ADS)

    Varnashev, K. B.

    2000-06-01

    The detailed analysis of the global structure of the renormalization-group (RG) flow diagram for a model with isotropic and cubic interactions is carried out in the framework of the massive field theory directly in three dimensions (3D) within an assumption of isotropic exchange. Perturbative expansions for RG functions are calculated for arbitrary N up to four-loop order and resummed by means of the generalized Padé-Borel-Leroy technique. Coordinates and stability matrix eigenvalues for the cubic fixed point are found under the optimal value of the transformation parameter. Critical dimensionality of the model is proved to be equal to Nc=2.89+/-0.02 that agrees well with the estimate obtained on the basis of the five-loop ɛ expansion [H. Kleinert and V. Schulte-Frohlinde, Phys. Lett. B 342, 284 (1995)] resummed by the above method. As a consequence, the cubic fixed point should be stable in 3D for N>=3, and the critical exponents controlling phase transitions in three-dimensional magnets should belong to the cubic universality class. The critical behavior of the random Ising model being the nontrivial particular case of the cubic model when N=0 is also investigated. For all physical quantities of interest the most accurate numerical estimates with their error bounds are obtained. The results achieved in the work are discussed along with the predictions given by other theoretical approaches and experimental data.

  8. Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points.

    PubMed

    Woolliams, E R; Anhalt, K; Ballico, M; Bloembergen, P; Bourson, F; Briaudeau, S; Campos, J; Cox, M G; del Campo, D; Dong, W; Dury, M R; Gavrilov, V; Grigoryeva, I; Hernanz, M L; Jahan, F; Khlevnoy, B; Khromchenko, V; Lowe, D H; Lu, X; Machin, G; Mantilla, J M; Martin, M J; McEvoy, H C; Rougié, B; Sadli, M; Salim, S G R; Sasajima, N; Taubert, D R; Todd, A D W; Van den Bossche, R; van der Ham, E; Wang, T; Whittam, A; Wilthan, B; Woods, D J; Woodward, J T; Yamada, Y; Yamaguchi, Y; Yoon, H W; Yuan, Z

    2016-03-28

    The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature. PMID:26903099

  9. Fixed point Open Ocean Observatory network (FixO3): Multidisciplinary observations from the air-sea interface to the deep seafloor

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard; Cristini, Luisa

    2014-05-01

    The Fixed point Open Ocean Observatory network (FixO3) seeks to integrate the 23 European open ocean fixed point observatories and to improve access to these key installations for the broader community. These will provide multidisciplinary observations in all parts of the oceans from the air-sea interface to the deep seafloor. Coordinated by the National Oceanography Centre, UK, FixO3 builds on the significant advances achieved through the previous Europe-funded FP7 programmes EuroSITES, ESONET and CARBOOCEAN. Started in September 2013 with a budget of 7 Million Euros over 4 years the project has 29 partners drawn from academia, research institutions and SME's. In addition 12 international experts from a wide range of disciplines comprise an Advisory Board. On behalf of the FixO3 Consortium, we present the programme that will be achieved through the activities of 12 Work Packages: 1. Coordination activities to integrate and harmonise the current procedures and processes. Strong links will be fostered with the wider community across academia, industry, policy and the general public through outreach, knowledge exchange and training. 2. Support actions to offer a) free access to observatory infrastructures to those who do not have such access, and b) free and open data services and products. 3. Joint research activities to innovate and enhance the current capability for multidisciplinary in situ ocean observation. Support actions include Transnational Access (TNA) to FixO3 infrastructure, meaning that European organizations can apply to free-of-charge access to the observatories for research and testing in two international calls during the project lifetime. The first call for TNA opens in summer 2014. More information can be found on FixO3 website (www.fixo3.eu/). Open ocean observation is currently a high priority for European marine and maritime activities. FixO3 will provide important data on environmental products and services to address the Marine Strategy

  10. The European Fixed point Open Ocean Observatory network (FixO3): Multidisciplinary observations from the air-sea interface to the deep seafloor

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard; Cristini, Luisa; Alexiou, Sofia

    2015-04-01

    The Fixed point Open Ocean Observatory network (FixO3, http://www.fixo3.eu/ ) integrates 23 European open ocean fixed point observatories and improves access to these infrastructures for the broader community. These provide multidisciplinary observations in all parts of the oceans from the air-sea interface to the deep seafloor. Started in September 2013 with a budget of 7 Million Euros over 4 years, the project has 29 partners drawn from academia, research institutions and SME's coordinated by the National Oceanography Centre, UK. Here we present the programme's achievements in the 18 months and the activities of the 12 Work Packages which have the objectives to: • integrate and harmonise the current procedures and processes • offer free access to observatory infrastructures to those who do not have such access, and free and open data services and products • innovate and enhance the current capability for multidisciplinary in situ ocean observation Open ocean observation is a high priority for European marine and maritime activities. FixO3 provides important data and services to address the Marine Strategy Framework Directive and in support of the European Integrated Maritime Policy. FixO3 provides a strong integrated framework of open ocean facilities in the Atlantic from the Arctic to the Antarctic and throughout the Mediterranean, enabling an integrated, regional and multidisciplinary approach to understand natural and anthropogenic change in the ocean.

  11. New Filling Technique and Performance Evaluations of the Cr3C2-C Peritectic Fixed Point

    NASA Astrophysics Data System (ADS)

    Sasajima, N.; Lowe, D.; Bai, C.; Yamada, Y.; Ara, C.

    2011-12-01

    The Cr3C2-C peritectic fixed point was investigated to test its capability to serve as a practical high-temperature fixed point. An improved filling technique where C/C sheet works as a wick and graphite paper as a hopper was applied successfully, and the long-term stability of the peritectic cell was evaluated by means of radiation thermometry. The repeatability of the melting point in one day was 7 mK with a melting range of approximately 100 mK. The cell was aged for 7 days, and the evaluated 56 melting temperatures during this period all fall within 90 mK, with a standard deviation of 19 mK. X-ray transmission photos showed that the ingot was filled uniformly in the crucible. After the evaluation of long-term stability, no clear degradation of the ingot shape and no leakage of molten metal were observed. From these results, it can be concluded that the Cr3C2-C peritectic cell has good stability and robustness, and the new filling technique was established. The impurity effect on the Cr3C2-C peritectic cell was also investigated by adding tungsten powder to another cell as the impurity component. After the observation of melting and freezing plateaux, the cell was cut in half to analyze the microstructure by means of electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The high concentration of impurity was observed in the area of the chromium-rich domain (eutectic mixture of Cr7C3 and Cr3C2), which suggests that impurities were rejected from the Cr3C2 peritectic phase during the peritectic freezing and were accumulated in the Cr7C3-Cr3C2 eutectic phase. This explains why the impurity effect is more severe for the Cr7C3-Cr3C2 eutectic point than for the Cr3C2-C peritectic point.

  12. Fixed points and stability in the two-network frustrated Kuramoto model

    NASA Astrophysics Data System (ADS)

    Kalloniatis, Alexander C.; Zuparic, Mathew L.

    2016-04-01

    We examine a modification of the Kuramoto model for phase oscillators coupled on a network. Here, two populations of oscillators are considered, each with different network topologies, internal and cross-network couplings and frequencies. Additionally, frustration parameters for the interactions of the cross-network phases are introduced. This may be regarded as a model of competing populations: internal to any one network phase synchronisation is a target state, while externally one or both populations seek to frequency synchronise to a phase in relation to the competitor. We conduct fixed point analyses for two regimes: one, where internal phase synchronisation occurs for each population with the potential for instability in the phase of one population in relation to the other; the second where one part of a population remains fixed in phase in relation to the other population, but where instability may occur within the first population leading to 'fragmentation'. We compare analytic results to numerical solutions for the system at various critical thresholds.

  13. Development and investigation of WC-C fixed-point cells

    NASA Astrophysics Data System (ADS)

    Khlevnoy, B. B.; Grigoryeva, I. A.; Otryaskin, D. A.

    2012-04-01

    Three cells of the WC-C peritectic fixed point with a temperature of about 3021 K were built and investigated. Two different sources of tungsten with nominal purities of 5N and 3N were used, and two different filling techniques were applied. There was no difference in plateau shapes between the cells. The 3N purity cell showed a small difference (0.22 K) in the melting temperature from the 5N cell, which indicates significant purification of initially contaminated tungsten. The typical melting range and repeatability of the observed peritectic melting plateaux were 100 mK and 15 mK, respectively. The melting point was stable and reproducible within 25 mK per two weeks. T90 temperature of the WC-C melting point was found to be (2747.6 ± 1.1) °C (k = 2). The observed freezing plateaux were flat and repeatable within 50 mK and 15 mK, respectively. The WC1-x-WC eutectic transition showed a melting temperature about 29 K lower than the peritectic one with a repeatability of about 0.2 K. The problem of deep supercooling is discussed and a method for its solution is shown and tested.

  14. Progress report for the CCT-WG5 high temperature fixed point research plan

    SciTech Connect

    Machin, G.; Woolliams, E. R.; Anhalt, K.; Bloembergen, P.; Sadli, M.; Yamada, Y.

    2013-09-11

    An overview of the progress in High Temperature Fixed Point (HTFP) research conducted under the auspices of the CCT-WG5 research plan is reported. In brief highlights are: Provisional long term stability of HTFPs has been demonstrated. Optimum construction methods for HTFPs have been established and high quality HTFPs of Co-C, Pt-C and Re-C have been constructed for thermodynamic temperature assignment. The major sources of uncertainty in the assignment of thermodynamic temperature have been identified and quantified. The status of absolute radiometric temperature measurement has been quantified through the circulation of a set of HTFPs. The measurement campaign to assign low uncertainty thermodynamic temperatures to a selected set of HTFPs will begin in mid-2012. It is envisaged that this will be complete by 2015 leading to HTFPs becoming routine reference standards for radiometry and high temperature metrology.

  15. Adaptive Control for Buck Power Converter Using Fixed Point Inducting Control and Zero Average Dynamics Strategies

    NASA Astrophysics Data System (ADS)

    Hoyos Velasco, Fredy Edimer; García, Nicolás Toro; Garcés Gómez, Yeison Alberto

    In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD-FPIC control techniques are shown.

  16. Infra-red fixed point structure characterising SUSY SU(5) symmetry breaking

    NASA Astrophysics Data System (ADS)

    Allanach, B. C.; Amelino-Camelia, G.; Philipsen, O.

    1997-02-01

    We analyze the one-loop renormalisation group equations for the parameters of the Higgs potential of a supersymmetric SU(5) model with first step of symmetry breaking involving an adjoint Higgs. In particular, we investigate the running of the parameters that decide the first step of symmetry breaking in an attempt to establish which symmetry-breaking scenarios would be most likely if the model is the effective low-energy description of some more fundamental theory. An infra-red fixed point is identified analytically. We show that it is located at the boundary between the region of Higgs parameter space corresponding to unbroken SU(5) and the region corresponding to the breaking of SU(5) to the Standard Model, and we elaborate on its implications. We also observe that certain forms of the Higgs potential discussed at tree level in the literature are not renormalisation group invariant.

  17. Matrix triangularization by fixed-point redundant CORDIC with constant scale factor

    NASA Astrophysics Data System (ADS)

    Lee, Jeong-A.; Lang, Tomas

    1990-11-01

    We develop a redundani CORDIC scheme where the scale factor is forced to be constant while computing angles for 2 x 1 plane rotations. Based on the scheme we present a fixed-point implementation of matrix triangularization by Luk''s parallel algorithm with the following additional features: (1) the final scaling operation is done by shifting (2) the number of iterations in CORDIC rotation unit is reduced by about 25 by expressing the direction of the rotation in radix-2 and radix-4 and (3) the conventional number representation of rotated output is obtained on-thefly not from a carry-propagate adder. The number of hardware modules and the speed are evaluated and compared with the previous CORDIC schemes.

  18. Density equalized map projections: a method for analysing clustering around a fixed point.

    PubMed

    Schulman, J; Selvin, S; Merrill, D W

    1988-04-01

    Cases plotted on a geopolitical map entail difficulties in interpretation and analysis because of variable population density in the study area. Density equalized map projections (DEMPs) eliminate the distribution of the resident population as an interfering influence by transforming map area to be proportional to population. This paper discusses a transformation algorithm, its properties, and develops statistical methods to detect clustering of cases around a fixed point for data plotted on DEMPs. We suggest two numeric methods where exact solutions are too complicated or do not exist. Finally, we illustrate these methods using data from Denver and Jefferson counties in Colorado to investigate whether lung cancer and leukaemia incidence patterns are associated with plutonium exposure from the Rocky Flats plant site. PMID:3368676

  19. Point and Fixed Plot Sampling Inventory Estimates at the Savannah River Site, South Carolina.

    SciTech Connect

    Parresol, Bernard, R.

    2004-02-01

    This report provides calculation of systematic point sampling volume estimates for trees greater than or equal to 5 inches diameter breast height (dbh) and fixed radius plot volume estimates for trees < 5 inches dbh at the Savannah River Site (SRS), Aiken County, South Carolina. The inventory of 622 plots was started in March 1999 and completed in January 2002 (Figure 1). Estimates are given in cubic foot volume. The analyses are presented in a series of Tables and Figures. In addition, a preliminary analysis of fuel levels on the SRS is given, based on depth measurements of the duff and litter layers on the 622 inventory plots plus line transect samples of down coarse woody material. Potential standing live fuels are also included. The fuels analyses are presented in a series of tables.

  20. Steering quantum dynamics via bang-bang control: Implementing optimal fixed-point quantum search algorithm

    NASA Astrophysics Data System (ADS)

    Bhole, Gaurav; Anjusha, V. S.; Mahesh, T. S.

    2016-04-01

    A robust control over quantum dynamics is of paramount importance for quantum technologies. Many of the existing control techniques are based on smooth Hamiltonian modulations involving repeated calculations of basic unitaries resulting in time complexities scaling rapidly with the length of the control sequence. Here we show that bang-bang controls need one-time calculation of basic unitaries and hence scale much more efficiently. By employing a global optimization routine such as the genetic algorithm, it is possible to synthesize not only highly intricate unitaries, but also certain nonunitary operations. We demonstrate the unitary control through the implementation of the optimal fixed-point quantum search algorithm in a three-qubit nuclear magnetic resonance (NMR) system. Moreover, by combining the bang-bang pulses with the crusher gradients, we also demonstrate nonunitary transformations of thermal equilibrium states into effective pure states in three- as well as five-qubit NMR systems.

  1. On the fixed points of monotonic operators in the critical case

    NASA Astrophysics Data System (ADS)

    Engibaryan, N. B.

    2006-10-01

    We consider the problem of constructing positive fixed points x of monotonic operators \\varphi acting on a cone K in a Banach space E. We assume that \\Vert\\varphi x\\Vert\\le\\Vert x\\Vert+\\gamma, \\gamma>0, for all x\\in K. In the case when \\varphi has a so-called non-trivial dissipation functional we construct a solution in an extension of E, which is a Banach space or a Fréchet space. We consider examples in which we prove the solubility of a conservative integral equation on the half-line with a sum-difference kernel, and of a non-linear integral equation of Urysohn type in the critical case.

  2. Crustal deformation measurements in central Japan determined by a Global Positioning System fixed-point network

    NASA Technical Reports Server (NTRS)

    Shimada, Seiichi; Bock, Yehuda

    1992-01-01

    Results are presented from temporally dense measurements of crustal deformation associated with the convergence of the Eurasian (EUR), Pacific, North American, and Philippine Sea (PHS) plates, carried out in April 1988 by a 10-station GPS fixed-point network established in central Japan. Using regional orbit relaxation methods, the analysis of the first 17-month data revealed significant horizontal deformation across the Suruga trough. Namely, it was found that a site in the northern tip of PHS plate moved nearly westward with a velocity of 28 +/-5 mm per year, and a site at the southeastern tip of EUR plate moved south-southwestward with a velocity of 18 +/-5 mm per year. A significant vertical uplift with a velocity of 20 mm/yr was detected at a site inland of the Tokai district located in the Akaishi uplift zone and at a site on the Hatsushima Island in Sagami Bay.

  3. Bratu's problem: A novel approach using fixed-point iterations and Green's functions

    NASA Astrophysics Data System (ADS)

    Kafri, H. Q.; Khuri, S. A.

    2016-01-01

    In this article, the one-dimensional non-linear Bratu's boundary value problem is solved via a novel approach that combines Green's function and fixed point iterative schemes, such as Picard's and Krasnoselskii-Mann's. The convergence of the introduced iterative algorithm is proved using the contraction principle. The method is supported by considering a number of numerical examples that correspond to different cases of eigenvalues. The procedure underlying the strategy reduces calculations and provides highly accurate results in comparison with the exact solution and/or numerical solutions provided in the literature. The current method overcomes the difficulty of treating the problem for eigenvalues near and at the critical value, such as λ = 3 and λ = 3.51, and handles them reliably and very efficiently.

  4. Infrared cameras are potential traceable "fixed points" for future thermometry studies.

    PubMed

    Yap Kannan, R; Keresztes, K; Hussain, S; Coats, T J; Bown, M J

    2015-01-01

    The National physical laboratory (NPL) requires "fixed points" whose temperatures have been established by the International Temperature Scale of 1990 (ITS 90) be used for device calibration. In practice, "near" blackbody radiators together with the standard platinum resistance thermometer is accepted as a standard. The aim of this study was to report the correlation and limits of agreement (LOA) of the thermal infrared camera and non-contact infrared temporal thermometer against each other and the "near" blackbody radiator. Temperature readings from an infrared thermography camera (FLIR T650sc) and a non-contact infrared temporal thermometer (Hubdic FS-700) were compared to a near blackbody (Hyperion R blackbody model 982) at 0.5 °C increments between 20-40 °C. At each increment, blackbody cavity temperature was confirmed with the platinum resistance thermometer. Measurements were taken initially with the thermal infrared camera followed by the infrared thermometer, with each device mounted in turn on a stand at a fixed distance of 20 cm and 5 cm from the blackbody aperture, respectively. The platinum thermometer under-estimated the blackbody temperature by 0.015 °C (95% LOA: -0.08 °C to 0.05 °C), in contrast to the thermal infrared camera and infrared thermometer which over-estimated the blackbody temperature by 0.16 °C (95% LOA: 0.03 °C to 0.28 °C) and 0.75 °C (95% LOA: -0.30 °C to 1.79 °C), respectively. Infrared thermometer over-estimates thermal infrared camera measurements by 0.6 °C (95% LOA: -0.46 °C to 1.65 °C). In conclusion, the thermal infrared camera is a potential temperature reference "fixed point" that could substitute mercury thermometers. However, further repeatability and reproducibility studies will be required with different models of thermal infrared cameras. PMID:26468981

  5. Realization of the WC-C peritectic fixed point at NIM and NMIJ

    SciTech Connect

    Wang, T.; Bai, C.; Yuan, Z.; Dong, W.; Lu, X.; Sasajima, N.; Yamada, Y.; Ara, C.

    2013-09-11

    Three WC-C peritectic fixed point cells, constructed from different sources of tungsten with different nominal purities, were measured at NIM and NMIJ. The three cells were constructed at NMIJ by NIM and NMIJ staffs, and T{sub 90} values of the three cells were measured at NMIJ during the period 31 Aug. to 25 Dec. 2009. Thereafter, the three cells were then transported to NIM, and T{sub 90} values of these cells were measured from 7 Dec. 2011 to 9 Jan. 2012. The results showed that T{sub 90} values of the three cells measured at the two institutes agreed within 0.4 °C with the combined scale comparison uncertainty of 1.7 °C (k= 2). The main component of the uncertainty is not the uncertainty due to impurities of the cells but the scale uncertainty and the stability of the measurement system. From these results it can be concluded that the WC-C cell is stable enough to provide new means of international high-temperature scale comparison above 3000 K.

  6. Universal self-similar dynamics of relativistic and nonrelativistic field theories near nonthermal fixed points

    NASA Astrophysics Data System (ADS)

    Piñeiro Orioli, Asier; Boguslavski, Kirill; Berges, Jürgen

    2015-07-01

    We investigate universal behavior of isolated many-body systems far from equilibrium, which is relevant for a wide range of applications from ultracold quantum gases to high-energy particle physics. The universality is based on the existence of nonthermal fixed points, which represent nonequilibrium attractor solutions with self-similar scaling behavior. The corresponding dynamic universality classes turn out to be remarkably large, encompassing both relativistic as well as nonrelativistic quantum and classical systems. For the examples of nonrelativistic (Gross-Pitaevskii) and relativistic scalar field theory with quartic self-interactions, we demonstrate that infrared scaling exponents as well as scaling functions agree. We perform two independent nonperturbative calculations, first by using classical-statistical lattice simulation techniques and second by applying a vertex-resummed kinetic theory. The latter extends kinetic descriptions to the nonperturbative regime of overoccupied modes. Our results open new perspectives to learn from experiments with cold atoms aspects about the dynamics during the early stages of our universe.

  7. Resource and Performance Evaluations of Fixed Point QRD-RLS Systolic Array through FPGA Implementation

    NASA Astrophysics Data System (ADS)

    Yokoyama, Yoshiaki; Kim, Minseok; Arai, Hiroyuki

    At present, when using space-time processing techniques with multiple antennas for mobile radio communication, real-time weight adaptation is necessary. Due to the progress of integrated circuit technology, dedicated processor implementation with ASIC or FPGA can be employed to implement various wireless applications. This paper presents a resource and performance evaluation of the QRD-RLS systolic array processor based on fixed-point CORDIC algorithm with FPGA. In this paper, to save hardware resources, we propose the shared architecture of a complex CORDIC processor. The required precision of internal calculation, the circuit area for the number of antenna elements and wordlength, and the processing speed will be evaluated. The resource estimation provides a possible processor configuration with a current FPGA on the market. Computer simulations assuming a fading channel will show a fast convergence property with a finite number of training symbols. The proposed architecture has also been implemented and its operation was verified by beamforming evaluation through a radio propagation experiment.

  8. Artifact Removal from Biosignal using Fixed Point ICA Algorithm for Pre-processing in Biometric Recognition

    NASA Astrophysics Data System (ADS)

    Mishra, Puneet; Singla, Sunil Kumar

    2013-01-01

    In the modern world of automation, biological signals, especially Electroencephalogram (EEG) and Electrocardiogram (ECG), are gaining wide attention as a source of biometric information. Earlier studies have shown that EEG and ECG show versatility with individuals and every individual has distinct EEG and ECG spectrum. EEG (which can be recorded from the scalp due to the effect of millions of neurons) may contain noise signals such as eye blink, eye movement, muscular movement, line noise, etc. Similarly, ECG may contain artifact like line noise, tremor artifacts, baseline wandering, etc. These noise signals are required to be separated from the EEG and ECG signals to obtain the accurate results. This paper proposes a technique for the removal of eye blink artifact from EEG and ECG signal using fixed point or FastICA algorithm of Independent Component Analysis (ICA). For validation, FastICA algorithm has been applied to synthetic signal prepared by adding random noise to the Electrocardiogram (ECG) signal. FastICA algorithm separates the signal into two independent components, i.e. ECG pure and artifact signal. Similarly, the same algorithm has been applied to remove the artifacts (Electrooculogram or eye blink) from the EEG signal.

  9. Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

    SciTech Connect

    Gotoh, M.

    2013-09-11

    Four Type A thermocouples and two Type C thermocouples were calibrated at the Au fixed point and Co-C and Pd-C eutectic fixed points. The thermocouples were exposed to 1330 °C for a total of 100 hours. The maximum drift due to the exposure was found to be 4.8 °C. The fixed-point calibration EMF of these thermocouples deviated by less than 0.86% from the temperature specified by the standards ASTM E230-2003 for Type C and GOSTR 8.585-2001 for Type A. The length of one of Type A thermocouples A52 is longer than the others by 150mm. Making use of this provision it was possible to place annealed part of A52 to the temperature gradient part of calibration arrangement every time. Therefore observed aging effect was as low as 0.5 °C compared to the other thermocouples.

  10. An InGaAs detector based radiation thermometer and fixed-point blackbodies for temperature scale realization at NIM

    SciTech Connect

    Hao, X.; Yuan, Z.; Wang, J.; Lu, X.

    2013-09-11

    In this paper, we describe an InGaAs detector based radiation thermometer (IRT) and new design of fixed-point blackbodies, including Sn, Zn, Al and Cu, for the establishment of a temperature scale from 200 °C to 1085 °C at the National Institute of Metrology of China. The construction and calibration of the IRT with the four fixed-point blackbodies are described. Characteristics of the IRT, such as the size-of-source effect, the amplifier performance and its stability are determined. The design of the four fixed-points, with 10 mm diameter of aperture and 0.9999 emissivity, is described. The uncertainty of the scale realization is elaborated.

  11. An InGaAs detector based radiation thermometer and fixed-point blackbodies for temperature scale realization at NIM

    NASA Astrophysics Data System (ADS)

    Hao, X.; Yuan, Z.; Wang, J.; Lu, X.

    2013-09-01

    In this paper, we describe an InGaAs detector based radiation thermometer (IRT) and new design of fixed-point blackbodies, including Sn, Zn, Al and Cu, for the establishment of a temperature scale from 200 °C to 1085 °C at the National Institute of Metrology of China. The construction and calibration of the IRT with the four fixed-point blackbodies are described. Characteristics of the IRT, such as the size-of-source effect, the amplifier performance and its stability are determined. The design of the four fixed-points, with 10 mm diameter of aperture and 0.9999 emissivity, is described. The uncertainty of the scale realization is elaborated.

  12. Manufacturing of MC Eutectics and Reproducibility of Pt-C Eutectic Fixed Points using a Thermogauge Furnace

    NASA Astrophysics Data System (ADS)

    Wang, T.; Lowe, D.; Machin, G.

    2009-02-01

    National Institute of Metrology (NIM) (China) and National Physical Laboratory (NPL) (UK) have collaborated to construct metal-carbon eutectic alloy fixed points at NPL. A modified NPL Thermogauge furnace was vertically used to construct fixed points of Pd-C, Pt-C, Ru-C, and Ir-C. Breakage of Pd-C and Ru-C cells was traced to changes in furnace temperature gradients resulting from changing from horizontal to vertical operation. Subsequently, it was found that positioning the cell being filled so that the metal melting always starts from the top and freezing from the bottom to solve this problem. The constructed Pt-C cell was then compared to a Pt-C fixed point previously constructed by NIM. The results indicate that the two cells made independently agreed to be better than 40 mK.

  13. A Jiles-Atherton and fixed-point combined technique for time periodic magnetic field problems with hysteresis

    SciTech Connect

    Chiampi, M.; Repetto, M.; Chiarabaglio, D.

    1995-11-01

    The hysteresis phenomenon can significantly affect the behavior of magnetic cores in electrical machines and devices. This paper presents a finite element solution of periodic steady state magnetic field problems in soft materials with scalar hysteresis. The Jiles-Atherton model is employed for the generation of symmetric B-H loops and it is coupled with the Fixed Point Technique for handling magnetic nonlinearities. The proposed procedure is applied to a hysteretic model problem whose analytical solution is available. The results show that the Fixed Point Technique can efficiently deal with non-single valued material characteristics under periodic operating conditions.

  14. Thermodynamic Temperatures of High-Temperature Fixed Points: Uncertainties Due to Temperature Drop and Emissivity

    NASA Astrophysics Data System (ADS)

    Castro, P.; Machin, G.; Bloembergen, P.; Lowe, D.; Whittam, A.

    2014-07-01

    This study forms part of the European Metrology Research Programme project implementing the New Kelvin to assign thermodynamic temperatures to a selected set of high-temperature fixed points (HTFPs), Cu, Co-C, Pt-C, and Re-C. A realistic thermal model of these HTFPs, developed in finite volume software ANSYS FLUENT, was constructed to quantify the uncertainty associated with the temperature drop across the back wall of the cell. In addition, the widely applied software package, STEEP3 was used to investigate the influence of cell emissivity. The temperature drop, , relates to the temperature difference due to the net loss of heat from the aperture of the cavity between the back wall of the cavity, viewed by the thermometer, defining the radiance temperature, and the solid-liquid interface of the alloy, defining the transition temperature of the HTFP. The actual value of can be used either as a correction (with associated uncertainty) to thermodynamic temperature evaluations of HTFPs, or as an uncertainty contribution to the overall estimated uncertainty. In addition, the effect of a range of furnace temperature profiles on the temperature drop was calculated and found to be negligible for Cu, Co-C, and Pt-C and small only for Re-C. The effective isothermal emissivity is calculated over the wavelength range from 450 nm to 850 nm for different assumed values of surface emissivity. Even when furnace temperature profiles are taken into account, the estimated emissivities change only slightly from the effective isothermal emissivity of the bare cell. These emissivity calculations are used to estimate the uncertainty in the temperature assignment due to the uncertainty in the emissivity of the blackbody.

  15. Duelling 'CyanoHABs': unravelling the environmental drivers controlling dominance and succession among diazotrophic and non-N2 -fixing harmful cyanobacteria.

    PubMed

    Paerl, Hans W; Otten, Timothy G

    2016-02-01

    Eutrophication often manifests itself by increased frequencies and magnitudes of cyanobacterial harmful algal blooms (CyanoHABs) in freshwater systems. It is generally assumed that nitrogen-fixing cyanobacteria will dominate when nitrogen (N) is limiting and non-N2 fixers dominate when N is present in excess. However, this is rarely observed in temperate lakes, where N2 fixers often bloom when N is replete, and non-fixers (e.g. Microcystis) dominate when N concentrations are lowest. This review integrates observations from previous studies with insights into the environmental factors that select for CyanoHAB groups. This information may be used to predict how nutrient reduction strategies targeting N, phosphorus (P) or both N and P may alter cyanobacterial community composition. One underexplored concern is that as N inputs are reduced, CyanoHABs may switch from non-N2 fixing to diazotrophic taxa, with no net improvement in water quality. However, monitoring and experimental observations indicate that in eutrophic systems, minimizing both N and P loading will lead to the most significant reductions in total phytoplankton biomass without this shift occurring, because successional patterns appear to be strongly driven by physical factors, including temperature, irradiance and hydrology. Notably, water temperature is a primary driver of cyanobacterial community succession, with warming favouring non-diazotrophic taxa. PMID:26310611

  16. The Grenville orogenic cycle of southern Laurentia: Unraveling sutures, rifts, and shear zones as potential piercing points for Amazonia

    NASA Astrophysics Data System (ADS)

    Bartholomew, Mervin J.; Hatcher, Robert D., Jr.

    2010-01-01

    region. Following the Rigolet phase, the Appalachian region continued to be characterized by NW-SE extension during the passage of a possible hotspot along a NE-track (760-600 Ma) across the Blue Ridge and other terranes, and during initial Iapetan rifting (565 Ma). The palinspastic rifted-margin of Laurentia crosses many of these terranes and sutures as well as the possible region of Rigolet extension and the possible hotspot track, thus providing many potential piercing points within the Grenville orogen for comparison with Paleozoic terranes like the Precordillera in South America.

  17. Unraveling expressionism

    NASA Astrophysics Data System (ADS)

    Truscott, Tadd; Darbois-Texier, Baptiste; Lovett, Benjamin; Brandenbourger, Martin; Maquet, Laurent; Pan, Zhao; Gilet, Tristan; Strivay, David; Dorbolo, Stéphane

    2015-11-01

    From the large facades of our buildings to the refinement of art canvas, paintings literally surround us and make our lives colorful. Artists are continually looking for novel methods to complement their expression and ideas, while instinctively manipulating the underlying physics. We attempt to unravel a phenomenon common to many modern canvas artists. In some paintings small droplets (0.1 - 5 mm) appear as a single color, however, on closer inspection are actually composed of multicolored spiral patterns (e.g., non-newtonian acrylic paint). High-speed imaging reveals that these assemblies occur when a droplet impinges on the edge of a small pool of paint. Upon impact, the droplet creates a crown with the falling droplet color on the inside of the crown and the pool colors on the outside. Ripping occurs in thin film feeding a rapid roll-up in the thicker ridge-line regions. These twisted formations are projected outward and break into small droplets that form the paint spirals. These beautiful formations, appreciated in their static form on canvas in museums around the world, are formed by equally beautiful physical phenomena.

  18. Formalin Fixed Paraffin Embedded Tissue as a Starting Point for PrPSc Detection by ELISA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Formalin fixed paraffin embedded tissue are regularly employed in TSE diagnosis by IHC, the standard by which all other diagnostic protocols are currently judged. While IHC affords advantages over diagnostic approaches that typically utilize fresh or frozen tissue, such as Western blot...

  19. Unraveling Parkinson's: Three Clues

    MedlinePlus

    ... Bar Home Current Issue Past Issues Unraveling Parkinson's: Three Clues Past Issues / Summer 2006 Table of Contents ... Dream Robber: Living with Parkinson's disease / Unraveling Parkinson's: Three Clues / Parkinson's Disease: The Newest Advances Summer 2006 ...

  20. The EuroSITES network: Integrating and enhancing fixed-point open ocean observatories around Europe

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard S.; Larkin, Kate E.; EuroSITES Consortium

    2010-05-01

    EuroSITES is a 3 year (2008-2011) EU collaborative project (3.5MEuro) with the objective to integrate and enhance the nine existing open ocean fixed point observatories around Europe (www.eurosites.info). These observatories are primarily composed of full depth moorings and make multidisciplinary in situ observations within the water column as the European contribution to the global array OceanSITES (www.oceansites.org). In the first 18 months, all 9 observatories have been active and integration has been significant through the maintenance and enhancement of observatory hardware. Highlights include the enhancement of observatories with sensors to measure O2, pCO2, chlorophyll, and nitrate in near real-time from the upper 1000 m. In addition, some seafloor missions are also actively supported. These include seafloor platforms currently deployed in the Mediterranean, one for tsunami detection and one to monitor fluid flow related to seismic activity and slope stability. Upcoming seafloor science missions in 2010 include monitoring benthic biological communities and associated biogeochemistry as indicators of climate change in both the Northeast Atlantic and Mediterranean. EuroSITES also promotes the development of innovative sensors and samplers in order to progress capability to measure climate-relevant properties of the ocean. These include further developing current technologies for autonomous long-term monitoring of oxygen consumption in the mesopelagic, pH and mesozooplankton abundance. Many of these science missions are directly related to complementary activities in other European projects such as EPOCA, HYPOX and ESONET. In 2010 a direct collaboration including in situ field work will take place between ESONET and EuroSITES. The demonstration mission MODOO (funded by ESONET) will be implemented in 2010 at the EuroSITES PAP observatory. Field work will include deployment of a seafloor lander system with various sensors which will send data to shore in real

  1. Two-stage fixed-bed gasifier with selectable middle gas off-take point

    DOEpatents

    Strickland, Larry D.; Bissett, Larry A.

    1992-01-01

    A two-stage fixed bed coal gasifier wherein an annular region is in registry with a gasification zone underlying a devolatilization zone for extracting a side stream of high temperature substantially tar-free gas from the gasifier. A vertically displaceable skirt means is positioned within the gasifier to define the lower portion of the annular region so that vertical displacement of the skirt means positions the inlet into the annular region in a selected location within or in close proximity to the gasification zone for providing a positive control over the composition of the side stream gas.

  2. Two-stage fixed-bed gasifier with selectable middle gas off-take point

    SciTech Connect

    Strickland, L.D.; Bissett, L.A.

    1991-12-31

    A two-stage fixed bed coal gasifier wherein an annular region is in registry with a gasification zone underlying a devolatilization zone for extracting a side stream of high temperature substantially tar-free gas from the gasifier. A vertically displaceable skirt means is positioned within the gasifier to define the lower portion of the annular region so that vertical displacement of the skirt means positions the inlet into the annular region in a selected location within or in close proximity to the gasification zone for providing a positive control over the composition of the side stream gas.

  3. On combining Thole's induced point dipole model with fixed charge distributions in molecular mechanics force fields.

    PubMed

    Antila, Hanne S; Salonen, Emppu

    2015-04-15

    The Thole induced point dipole model is combined with three different point charge fitting methods, Merz-Kollman (MK), charges from electrostatic potentials using a grid (CHELPG), and restrained electrostatic potential (RESP), and two multipole algorithms, distributed multipole analysis (DMA) and Gaussian multipole model (GMM), which can be used to describe the electrostatic potential (ESP) around molecules in molecular mechanics force fields. This is done to study how the different methods perform when intramolecular polarizability contributions are self-consistently removed from the fitting done in the force field parametrization. It is demonstrated that the polarizable versions of the partial charge models provide a good compromise between accuracy and computational efficiency in describing the ESP of small organic molecules undergoing conformational changes. For the point charge models, the inclusion of polarizability reduced the the average root mean square error of ESP over the test set by 4-10%. PMID:25753482

  4. SU-E-T-539: Fixed Versus Variable Optimization Points in Combined-Mode Modulated Arc Therapy Planning

    SciTech Connect

    Kainz, K; Prah, D; Ahunbay, E; Li, X

    2014-06-01

    Purpose: A novel modulated arc therapy technique, mARC, enables superposition of step-and-shoot IMRT segments upon a subset of the optimization points (OPs) of a continuous-arc delivery. We compare two approaches to mARC planning: one with the number of OPs fixed throughout optimization, and another where the planning system determines the number of OPs in the final plan, subject to an upper limit defined at the outset. Methods: Fixed-OP mARC planning was performed for representative cases using Panther v. 5.01 (Prowess, Inc.), while variable-OP mARC planning used Monaco v. 5.00 (Elekta, Inc.). All Monaco planning used an upper limit of 91 OPs; those OPs with minimal MU were removed during optimization. Plans were delivered, and delivery times recorded, on a Siemens Artiste accelerator using a flat 6MV beam with 300 MU/min rate. Dose distributions measured using ArcCheck (Sun Nuclear Corporation, Inc.) were compared with the plan calculation; the two were deemed consistent if they agreed to within 3.5% in absolute dose and 3.5 mm in distance-to-agreement among > 95% of the diodes within the direct beam. Results: Example cases included a prostate and a head-and-neck planned with a single arc and fraction doses of 1.8 and 2.0 Gy, respectively. Aside from slightly more uniform target dose for the variable-OP plans, the DVHs for the two techniques were similar. For the fixed-OP technique, the number of OPs was 38 and 39, and the delivery time was 228 and 259 seconds, respectively, for the prostate and head-and-neck cases. For the final variable-OP plans, there were 91 and 85 OPs, and the delivery time was 296 and 440 seconds, correspondingly longer than for fixed-OP. Conclusion: For mARC, both the fixed-OP and variable-OP approaches produced comparable-quality plans whose delivery was successfully verified. To keep delivery time per fraction short, a fixed-OP planning approach is preferred.

  5. Typical Orbits of Quadratic Polynomials with a Neutral Fixed Point: Brjuno Type

    NASA Astrophysics Data System (ADS)

    Cheraghi, Davoud

    2013-09-01

    We describe the topological behavior of typical orbits of complex quadratic polynomials {P_{α}(z) = e^{2 π α {i}} z + z2}, with α of high return type. Here we prove that for such Brjuno values of α the closure of the critical orbit, which is the measure theoretic attractor of the map, has zero area. Then we show that the limit set of the orbit of a typical point in the Julia set of P α is equal to the closure of the critical orbit. Our method is based on the near parabolic renormalization of Inou-Shishikura, and a uniform optimal estimate on the derivative of the Fatou coordinate that we prove here.

  6. Construction of Home-Made Tin Fixed-Point Cell at TUBITAK UME

    NASA Astrophysics Data System (ADS)

    Kalemci, M.; Arifovic, N.; Bağçe, A.; Aytekin, S. O.; Ince, A. T.

    2015-08-01

    TUBITAK UME Temperature Laboratory initiated a new study which focuses on the construction of a tin freezing-point cell as a primary temperature standard. The design is an open-cell type similar to the National Institute of Standards and Technology design. With this aim, a brand new vacuum and filling line employing an oil diffusion pump and two cold traps (liquid nitrogen and dry ice) was set-up. The graphite parts (crucible, thermometer well, etc.) have been baked at high temperature under vacuum. Each cell was filled with approximately 1 kg of high-purity tin (99.9999 %) in a three-zone furnace. Then several melting and freezing curves were obtained to assess the quality of the home-made cell, and also the new cell was compared with the existing reference cell of the laboratory. The results obtained are very close to the reference cell of UME, indicating that the method used for fabrication was promising and satisfactory and also seems to meet the requirements to have a primary level temperature standard.

  7. A Phase-Field Solidification Model of Almost Pure ITS-90 Fixed Points

    NASA Astrophysics Data System (ADS)

    Large, M. J.; Pearce, J. V.

    2014-07-01

    A two-dimensional axisymmetric phase-field model of thermo-solutal solidification in freezing-point cells used for calibrating standard platinum resistance thermometers for realization and dissemination of the International Temperature Scale of 1990 is presented. The cell is essentially a graphite crucible containing an ingot of very pure metal (of order 99.9999 %). A graphite tube is inserted along the axis of the ingot to enable immersion of the thermometer in the metal. In this study, the metal is tin (freezing temperature of ). During the freezing of these cells, a steady, reproducible temperature is realized, with a defined temperature that can be used to calibrate thermometers with uncertainties mK. The model is applied to understand the effect of experimental parameters, such as initiation technique and furnace homogeneity, on the measured freezing curve. Results show that freezing curves whose behavior is consistent with the Scheil theory of solidification can be obtained with a specific furnace temperature profile, and provided that the freeze is of a long duration, the results are consistent with previous one-dimensional models and experiments. Morphological instability is observed with the inner interface initiation technique, causing the interface to adopt a cellular structure. This elevates the measured temperature, in accordance with the Gibbs-Thomson effect. In addition, the influence of initiation techniques on the solidification behavior is examined. The model indicates that an initially smooth inner mantle can `de-wet' from the thermometer well-forming agglomerated solid droplets, following recalescence, under certain conditions. This manifests as a measured temperature depression due to the Gibbs-Thomson effect, with a magnitude of to in simulations. The temperature rises to that of the stable outer mantle as freezing progresses and the droplets re-melt. It is demonstrated that the effect occurs below a critical mantle thickness. A physical

  8. Thermodynamic temperature measurements of the melting temperatures of Co-C, Pt-C and Re-C fixed points at NRC

    NASA Astrophysics Data System (ADS)

    Todd, A. D. W.; Woods, D. J.

    2013-02-01

    This paper outlines measurements made at the National Research Council Canada (NRC) of the thermodynamic melting temperatures of Co-C, Pt-C and Re-C fixed points that have been part of the high-temperature fixed-point research plan of Working Group 5 of the Consultative Committee for Thermometry (CCT-WG5) to assign melting temperatures to those fixed points. This document will outline the equipment used, describe the scheme used to calibrate a pyrometer with traceability to a cryogenic electrical substitution radiometer, and detail the method of measuring the fixed points. It will then report the uncertainties in the measurements and the results. A brief description of the improvements that we plan to implement to the scheme to reduce the uncertainties for future measurements will be given. The thermodynamic temperatures determined for the three fixed points are: 1597.776 K with an expanded uncertainty of 0.36 K, 2011.390 K with an expanded uncertainty of 0.55 K, and 2748.056 K with an expanded uncertainty of 0.95 K, for the Co-C, Pt-C and Re-C fixed points, respectively (all expanded uncertainties assume a 95% confidence interval and a Gaussian distribution).

  9. A new approach based on embedding Green's functions into fixed-point iterations for highly accurate solution to Troesch's problem

    NASA Astrophysics Data System (ADS)

    Kafri, H. Q.; Khuri, S. A.; Sayfy, A.

    2016-03-01

    In this paper, a novel approach is introduced for the solution of the non-linear Troesch's boundary value problem. The underlying strategy is based on Green's functions and fixed-point iterations, including Picard's and Krasnoselskii-Mann's schemes. The resulting numerical solutions are compared with both the analytical solutions and numerical solutions that exist in the literature. Convergence of the iterative schemes is proved via manipulation of the contraction principle. It is observed that the method handles the boundary layer very efficiently, reduces lengthy calculations, provides rapid convergence, and yields accurate results particularly for large eigenvalues. Indeed, to our knowledge, this is the first time that this problem is solved successfully for very large eigenvalues, actually the rate of convergence increases as the magnitude of the eigenvalues increases.

  10. Characterizing the size distribution of particles in urban stormwater by use of fixed-point sample-collection methods

    USGS Publications Warehouse

    Selbig, William R.; Bannerman, Roger T.

    2011-01-01

    The U.S Geological Survey, in cooperation with the Wisconsin Department of Natural Resources (WDNR) and in collaboration with the Root River Municipal Stormwater Permit Group monitored eight urban source areas representing six types of source areas in or near Madison, Wis. in an effort to improve characterization of particle-size distributions in urban stormwater by use of fixed-point sample collection methods. The types of source areas were parking lot, feeder street, collector street, arterial street, rooftop, and mixed use. This information can then be used by environmental managers and engineers when selecting the most appropriate control devices for the removal of solids from urban stormwater. Mixed-use and parking-lot study areas had the lowest median particle sizes (42 and 54 (u or mu)m, respectively), followed by the collector street study area (70 (u or mu)m). Both arterial street and institutional roof study areas had similar median particle sizes of approximately 95 (u or mu)m. Finally, the feeder street study area showed the largest median particle size of nearly 200 (u or mu)m. Median particle sizes measured as part of this study were somewhat comparable to those reported in previous studies from similar source areas. The majority of particle mass in four out of six source areas was silt and clay particles that are less than 32 (u or mu)m in size. Distributions of particles ranging from 500 (u or mu)m were highly variable both within and between source areas. Results of this study suggest substantial variability in data can inhibit the development of a single particle-size distribution that is representative of stormwater runoff generated from a single source area or land use. Continued development of improved sample collection methods, such as the depth-integrated sample arm, may reduce variability in particle-size distributions by mitigating the effect of sediment bias inherent with a fixed-point sampler.

  11. Experiments with powdered CMN thermometers between 10 mK and 4K, and a comparison with an NBS SRM 768 fixed-point device

    SciTech Connect

    Fogle, W.E.; Hornung, E.W.; Mayberry, M.C.; Phillips, N.E.

    1981-08-01

    Comparison of a powdered CMN thermometer with an NBS fixed point device demonstrates an internal inconsistency in the T/sub c/'s assigned to the fixed point device. T/sub c/'s between 100 and 200 mK are in excellent agreement with a temperature scale interpolated between He vapor pressure temperatures and nuclear orientation temperatures, but there is a discrepancy of 8% at the 15 mK point. Evidence for different susceptibility-temperature relations for superficially similar CMN thermometers is also presented.

  12. Factorization of the (2+1)-dimensional BLP integrable system by the periodic fixed points of its Bäcklund transformations

    NASA Astrophysics Data System (ADS)

    Weiss, John

    1991-11-01

    Previously, we have found a factorization of the (1+1)-dimensional Toda lattice by the periodic fixed points of its Bäcklund transformations. The Toda flow is realized by two commuting, one-dimensional Hamiltonian flows. By a result of Konopelchenko, the Laplace-Darboux transformation is a Bäcklund transformation for the (2+1)-dimensional Boiti-Leon-Pempinelli (BLP) equation. A periodic fixed point of the Laplace transformation is an invariant manifold of the BLP flow. This manifold is determined by solutions of the (1+1)-dimensional Toda lattice equations. From these results we find that the 2+1 BLP flow is factored by three commuting, one-dimensional Hamiltonian flows that are the periodic fixed points of its Bäcklund transformations.

  13. A Comparison of Deterministic and Stochastic Modeling Approaches for Biochemical Reaction Systems: On Fixed Points, Means, and Modes

    PubMed Central

    Hahl, Sayuri K.; Kremling, Andreas

    2016-01-01

    In the mathematical modeling of biochemical reactions, a convenient standard approach is to use ordinary differential equations (ODEs) that follow the law of mass action. However, this deterministic ansatz is based on simplifications; in particular, it neglects noise, which is inherent to biological processes. In contrast, the stochasticity of reactions is captured in detail by the discrete chemical master equation (CME). Therefore, the CME is frequently applied to mesoscopic systems, where copy numbers of involved components are small and random fluctuations are thus significant. Here, we compare those two common modeling approaches, aiming at identifying parallels and discrepancies between deterministic variables and possible stochastic counterparts like the mean or modes of the state space probability distribution. To that end, a mathematically flexible reaction scheme of autoregulatory gene expression is translated into the corresponding ODE and CME formulations. We show that in the thermodynamic limit, deterministic stable fixed points usually correspond well to the modes in the stationary probability distribution. However, this connection might be disrupted in small systems. The discrepancies are characterized and systematically traced back to the magnitude of the stoichiometric coefficients and to the presence of nonlinear reactions. These factors are found to synergistically promote large and highly asymmetric fluctuations. As a consequence, bistable but unimodal, and monostable but bimodal systems can emerge. This clearly challenges the role of ODE modeling in the description of cellular signaling and regulation, where some of the involved components usually occur in low copy numbers. Nevertheless, systems whose bimodality originates from deterministic bistability are found to sustain a more robust separation of the two states compared to bimodal, but monostable systems. In regulatory circuits that require precise coordination, ODE modeling is thus still

  14. Analogies between the Torque-Free Motion of a Rigid Body about a Fixed Point and Light Propagation in Anisotropic Media

    ERIC Educational Resources Information Center

    Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

    2009-01-01

    An apparently unnoticed analogy between the torque-free motion of a rotating rigid body about a fixed point and the propagation of light in anisotropic media is stated. First, a new plane construction for visualizing this torque-free motion is proposed. This method uses an intrinsic representation alternative to angular momentum and independent of…

  15. Strong Convergence Theorems for a Common Fixed Point of a Finite Family of Bregman Weak Relativity Nonexpansive Mappings in Reflexive Banach Spaces

    PubMed Central

    2014-01-01

    We introduce an iterative process for finding an element of a common fixed point of a finite family of Bregman weak relatively nonexpansive mappings. Our theorems improve and unify most of the results that have been proved for this important class of nonlinear operators. PMID:24757423

  16. Centrifugal multiplexing fixed-volume dispenser on a plastic lab-on-a-disk for parallel biochemical single-end-point assays

    PubMed Central

    La, Moonwoo; Park, Sang Min; Kim, Dong Sung

    2015-01-01

    In this study, a multiple sample dispenser for precisely metered fixed volumes was successfully designed, fabricated, and fully characterized on a plastic centrifugal lab-on-a-disk (LOD) for parallel biochemical single-end-point assays. The dispenser, namely, a centrifugal multiplexing fixed-volume dispenser (C-MUFID) was designed with microfluidic structures based on the theoretical modeling about a centrifugal circumferential filling flow. The designed LODs were fabricated with a polystyrene substrate through micromachining and they were thermally bonded with a flat substrate. Furthermore, six parallel metering and dispensing assays were conducted at the same fixed-volume (1.27 μl) with a relative variation of ±0.02 μl. Moreover, the samples were metered and dispensed at different sub-volumes. To visualize the metering and dispensing performances, the C-MUFID was integrated with a serpentine micromixer during parallel centrifugal mixing tests. Parallel biochemical single-end-point assays were successfully conducted on the developed LOD using a standard serum with albumin, glucose, and total protein reagents. The developed LOD could be widely applied to various biochemical single-end-point assays which require different volume ratios of the sample and reagent by controlling the design of the C-MUFID. The proposed LOD is feasible for point-of-care diagnostics because of its mass-producible structures, reliable metering/dispensing performance, and parallel biochemical single-end-point assays, which can identify numerous biochemical. PMID:25610516

  17. The Humanities, Unraveled

    ERIC Educational Resources Information Center

    Berube, Michael

    2013-01-01

    Graduate education in the humanities is in crisis. Every aspect, from the most specific details of the curriculum to the broadest questions about its purpose, is in crisis. It is a seamless garment of crisis: If one pulls on any one thread, the entire thing unravels. It is therefore exceptionally difficult to discuss any one aspect of graduate…

  18. Unraveling energy conversion modeling in the intrinsic persistent upconverted luminescence of solids: a study of native point defects in antiferromagnetic Er2O3.

    PubMed

    Huang, Bolong

    2016-05-11

    We investigated the mechanism of the intrinsic persistent luminescence of Er2O3 in the A-type lattice based on first-principles calculations. We found that the native point defects were engaged in mutual subtle interactions in the form of chemical reactions between different charge states. The release of energy related to lattice distortion facilitates the conversion of energy for electrons to be transported between the valence band and the trap levels or even between the deep trap levels so as to generate persistent luminescence. The defect transitions that take place along the zero-phonon line release energy to enable optical transitions, with the exact amount of negative effective correlation energy determined by the lattice distortions. Our calculations on the thermodynamic transition levels confirm that both the visible and NIR experimentally observed intrinsic persistent luminescence (phosphor or afterglow) are related to the thermodynamic transition levels of oxygen-related defects, and the thermodynamic transition levels within different charge states for these defects are independent of the chemical potentials of the given species. Lattice distortion defects such as anion Frenkel (a-Fr) pair defects play an important role in transporting O-related defects between different lattice sites. To obtain red persistent luminescence that matches the biological therapeutic window, it is suggested to increase the electron transition levels between high-coordinated O vacancies and related metastable a-Fr defects; a close-packed core-shell structure is required to quench low-coordinated O-related defects so as to reduce the green band luminescence. We further established a conversed chain reaction (CCR) model to interpret the energy conversion process of persistent luminescence in terms of the inter-reactions of native point defects between different charge states. It is advantageous to use the study of defect levels combined with formation energies to suggest limits

  19. Entanglement, quantum phase transition and fixed-point bifurcation in the N-atom Jaynes Cummings model with an additional symmetry breaking term

    NASA Astrophysics Data System (ADS)

    Chagas, E. A.; Furuya, K.

    2008-08-01

    In the present work we analyze the quantum phase transition (QPT) in the N-atom Jaynes-Cummings model (NJCM) with an additional symmetry breaking interaction term in the Hamiltonian. We show that depending on the type of symmetry breaking term added the transition order can change or not and also the fixed point associated to the classical analogue of the Hamiltonian can bifurcate or not. We present two examples of symmetry broken Hamiltonians and discuss based on them, the interconnection between the transition order, appearance of bifurcation and the behavior of the entanglement.

  20. The optimal launching of a space vehicle from the surface of the moon to a fixed point on the circular orbit of its artificial satellite

    NASA Astrophysics Data System (ADS)

    Grigor'ev, K. G.; Zapletina, E. V.; Zapletin, M. P.

    1992-06-01

    The paper presents an analysis and results of a numerical solution, based on the maximum principle, of three types of problems concerning the optimal launching of a space vehicle with a high-thrust rocket engine from the lunar surface to a fixed point on the circular orbit of a lunar artificial satellite. Attention is given to the problems of the fastest possible launching time, launching with minimal mass expenditure, and minimal trade-off functional (a compromise between expenditures for launch time and mass). The shooting method is used to obtain exact numerical solutions for the appropriate maximum principle boundary problems.

  1. Zinc-Bismuth and Aluminum-Indium Monotectic Alloy-Based Fixed-Point Cells with Double Phase Transition for In Situ Calibration of Thermocouples

    NASA Astrophysics Data System (ADS)

    Lowe, Dave; Kodwani, Darsh

    2015-11-01

    Re-calibration of a thermocouple after it has been installed in a process is often not practical. In situ monitoring of performance is desirable and can be done with built-in reference standards based on melting or freezing phase transitions. Binary alloys with a monotectic reaction frequently have two invariant melt/freeze phase transitions taking place in the same material over a range of compositions. This makes them potentially well suited to be in situ temperature calibration artifacts, enabling correction for thermocouple drift without the need to disturb the thermocouple. A zinc-bismuth fixed-point cell was constructed and has been shown to be stable with two well-defined melting plateaus at nominally 255°C and 415°C. Two miniature fixed-point cells (each designed to be permanently installed with a thermocouple) based on zinc-bismuth and aluminum-indium alloys were made. Measurements have shown that the phase transitions can be identified despite the small quantity of metals used and that the alloys were sufficiently stable to have the potential to provide improved long-term confidence in process control and monitoring.

  2. Tightly Coupled Integration of GPS Ambiguity Fixed Precise Point Positioning and MEMS-INS through a Troposphere-Constrained Adaptive Kalman Filter

    PubMed Central

    Han, Houzeng; Xu, Tianhe; Wang, Jian

    2016-01-01

    Precise Point Positioning (PPP) makes use of the undifferenced pseudorange and carrier phase measurements with ionospheric-free (IF) combinations to achieve centimeter-level positioning accuracy. Conventionally, the IF ambiguities are estimated as float values. To improve the PPP positioning accuracy and shorten the convergence time, the integer phase clock model with between-satellites single-difference (BSSD) operation is used to recover the integer property. However, the continuity and availability of stand-alone PPP is largely restricted by the observation environment. The positioning performance will be significantly degraded when GPS operates under challenging environments, if less than five satellites are present. A commonly used approach is integrating a low cost inertial sensor to improve the positioning performance and robustness. In this study, a tightly coupled (TC) algorithm is implemented by integrating PPP with inertial navigation system (INS) using an Extended Kalman filter (EKF). The navigation states, inertial sensor errors and GPS error states are estimated together. The troposphere constrained approach, which utilizes external tropospheric delay as virtual observation, is applied to further improve the ambiguity-fixed height positioning accuracy, and an improved adaptive filtering strategy is implemented to improve the covariance modelling considering the realistic noise effect. A field vehicular test with a geodetic GPS receiver and a low cost inertial sensor was conducted to validate the improvement on positioning performance with the proposed approach. The results show that the positioning accuracy has been improved with inertial aiding. Centimeter-level positioning accuracy is achievable during the test, and the PPP/INS TC integration achieves a fast re-convergence after signal outages. For troposphere constrained solutions, a significant improvement for the height component has been obtained. The overall positioning accuracies of the height

  3. Tightly Coupled Integration of GPS Ambiguity Fixed Precise Point Positioning and MEMS-INS through a Troposphere-Constrained Adaptive Kalman Filter.

    PubMed

    Han, Houzeng; Xu, Tianhe; Wang, Jian

    2016-01-01

    Precise Point Positioning (PPP) makes use of the undifferenced pseudorange and carrier phase measurements with ionospheric-free (IF) combinations to achieve centimeter-level positioning accuracy. Conventionally, the IF ambiguities are estimated as float values. To improve the PPP positioning accuracy and shorten the convergence time, the integer phase clock model with between-satellites single-difference (BSSD) operation is used to recover the integer property. However, the continuity and availability of stand-alone PPP is largely restricted by the observation environment. The positioning performance will be significantly degraded when GPS operates under challenging environments, if less than five satellites are present. A commonly used approach is integrating a low cost inertial sensor to improve the positioning performance and robustness. In this study, a tightly coupled (TC) algorithm is implemented by integrating PPP with inertial navigation system (INS) using an Extended Kalman filter (EKF). The navigation states, inertial sensor errors and GPS error states are estimated together. The troposphere constrained approach, which utilizes external tropospheric delay as virtual observation, is applied to further improve the ambiguity-fixed height positioning accuracy, and an improved adaptive filtering strategy is implemented to improve the covariance modelling considering the realistic noise effect. A field vehicular test with a geodetic GPS receiver and a low cost inertial sensor was conducted to validate the improvement on positioning performance with the proposed approach. The results show that the positioning accuracy has been improved with inertial aiding. Centimeter-level positioning accuracy is achievable during the test, and the PPP/INS TC integration achieves a fast re-convergence after signal outages. For troposphere constrained solutions, a significant improvement for the height component has been obtained. The overall positioning accuracies of the height

  4. REPLICATION OF "UNRAVELING JUVENILE DELINQUENCY" IN PUERTO RICO.

    ERIC Educational Resources Information Center

    GLUECK, SHELDON; AND OTHERS

    THE 1ST YEAR OF A 5- TO 6-YEAR PROJECT TO REPLICATE A BOSTON STUDY OF JUVENILE DELINQUENCY IN PUERTO RICO WAS REPORTED. THIS FINAL REPORT COVERS ONLY THE PILOT PHASE OF THE PROJECT. THE PROBLEM ON WHICH THE RESEARCH IS FOCUSED IS TO DETERMINE WHICH OF THE FINDINGS OF "UNRAVELING JUVENILE DELINQUENCY," AS THE STARTING POINT FOR THE PUERTO RICAN…

  5. Performance of Pt-C, CrC-CrC, CrC-C, and Ru-C Fixed Points for Thermocouple Calibrations Above 1600 C

    NASA Astrophysics Data System (ADS)

    Pearce, J. V.; Elliott, C. J.; Lowe, D. H.; Failleau, G.; Deuzé, T.; Bourson, F.; Sadli, M.; Machin, G.

    2014-04-01

    A series of high-temperature fixed points (HTFPs) Pt-C (1738 , and Ru-C (1953 ) have been constructed at the National Physical Laboratory (NPL) and the Laboratoire National de métrologie et d'Essais and Conservatoire national des arts et métiers (LNE-Cnam). These are required for the calibration of high-temperature thermocouples in the framework of work package 6 of the European Metrology Research Programme IND01 project "HiTeMS." The goal of this work package is to establish a European capability that can determine low-uncertainty reference functions of non-standard high-temperature thermocouples. For reference functions to be widely applicable, measurements must be performed by more than one institute and preferably by more than one method. Due to the high price of the ingot materials, miniature HTFP cells are used. NPL and LNE-Cnam constructed their HTFP cells with different designs; these are described here, together with the performance of the cells using both radiation thermometry and thermocouples. The melting temperature of the Ru-C cells (for thermocouple calibrations) was determined using radiation thermometry at both NPL and LNE-Cnam, and the two results are compared. The suitability of the cells for calibration of W-Re and Rh-Ir thermocouples is evaluated, and some results are presented. Some discussion is given regarding the materials challenges when calibrating Rh-Ir thermocouples up to 2000 C.

  6. Fixed-point observation of mixed layer evolution in seasonally ice-free Chukchi Sea: Turbulent mixing due to gale winds and internal gravity waves

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Y.; Inoue, J.; Nishino, S.

    2015-12-01

    A fixed-point observation using the R/V Mirai was conducted in the ice-free northern Chukchi Sea of the Arctic Ocean during September of 2013. During the program the authors performed repeated microstructure measurements to reveal the temporal evolution of the surface mixed layer and mixing processes in the upper water column. The shelf region was initially characterized by a distinct two-layer system comprising a warmer/ fresher top layer and a colder/saltier bottom layer. During the two-week observation period, the top-layer water showed two types of mixing processes: near-surface turbulence due to strong wind forcing and subsurface mixing due to internal gravity waves. In the first week, when the top layer was stratified with fresh sea ice meltwater, turbulent energy related to internal waves propagated through the subsurface stratification, resulting in a mechanical overturning near the pycnocline, followed by enhanced mixing there. In the second week, gale winds directly stirred up the upper water and then established a deeper homogenous layer. The combination of internal wave mixing and wind-driven turbulence may contribute to releasing the oceanic heat into the atmosphere, consequently promoting the preconditioning of surface water freezing.

  7. Biophysical chemistry: Unravelling capsid transformations

    NASA Astrophysics Data System (ADS)

    Uchida, Masaki; Douglas, Trevor

    2013-06-01

    The interactions between a virus capsid and its cargo are essential for viral infection as well as in the design of synthetic virus-like particles. Now a combination of analytical techniques has unravelled key steps in the transformation of a model virus and the release of its RNA cargo.

  8. Influences of diurnal sampling bias on fixed-point monitoring of plankton biodiversity determined using a massively parallel sequencing-based technique.

    PubMed

    Nagai, Satoshi; Hida, Kohsuke; Urushizaki, Shingo; Onitsuka, Goh; Yasuike, Motoshige; Nakamura, Yoji; Fujiwara, Atushi; Tajimi, Seisuke; Kimoto, Katsunori; Kobayashi, Takanori; Gojobori, Takashi; Ototake, Mitsuru

    2016-02-01

    In this study, we investigated the influence of diurnal sampling bias on the community structure of plankton by comparing the biodiversity among seawater samples (n=9) obtained every 3h for 24h by using massively parallel sequencing (MPS)-based plankton monitoring at a fixed point conducted at Himedo seaport in Yatsushiro Sea, Japan. The number of raw operational taxonomy units (OTUs) and OTUs after re-sampling was 507-658 (558 ± 104, mean ± standard deviation) and 448-544 (467 ± 81), respectively, indicating high plankton biodiversity at the sampling location. The relative abundance of the top 20 OTUs in the samples from Himedo seaport was 48.8-67.7% (58.0 ± 5.8%), and the highest-ranked OTU was Pseudo-nitzschia species (Bacillariophyta) with a relative abundance of 17.3-39.2%, followed by Oithona sp. 1 and Oithona sp. 2 (Arthropoda). During seawater sampling, the semidiurnal tidal current having an amplitude of 0.3ms(-1) was dominant, and the westward residual current driven by the northeasterly wind was continuously observed during the 24-h monitoring. Therefore, the relative abundance of plankton species apparently fluctuated among the samples, but no significant difference was noted according to G-test (p>0.05). Significant differences were observed between the samples obtained from a different locality (Kusuura in Yatsushiro Sea) and at different dates, suggesting that the influence of diurnal sampling bias on plankton diversity, determined using the MPS-based survey, was not significant and acceptable. PMID:26475937

  9. NASA's SDO Sees Unraveling Solar Prominence

    NASA Video Gallery

    An elongated solar prominence rose up above the sun’s surface and slowly unraveled on Feb. 3, 2016, as seen in this video by NASA’s Solar Dynamics Observatory, or SDO. The sun appears to move in th...

  10. Research and operational products from the combination of a monthly hydrographic station and an oceanic buoy: The Biscay AGL fixed-point water column observatory.

    NASA Astrophysics Data System (ADS)

    Lavin, Alicia; Cano, Daniel; González-Pola, Cesar; Tel, Elena; Rodriguez, Carmen; Ruiz, Manuel; Somavilla, Raquel

    2015-04-01

    , but Dissolved Oxygen sensor is also problematic. Periods of realistic smooth variations present strong offset that is corrected based on the Winkler analysis of water samples. The incorporation of these observatories on larger scale research programs, as done in 2003 in the framework of the VACLAN and COVACLAN projects, is important in order to provide them with a larger spatial dimension and maximize its utility for process-oriented studies. In 2003, the Santander section was extended 90 miles offshore in the framework of a large-scale hydrographic and circulation monitoring program. Partnerships in a large EU project as FixO3 has provided tools for coordination, homogenization and data validation as well as improve the use of chemical-biological data.

  11. Primitive models of chemical association. III. Totally flexible sticky two-point model for multicomponent heteronuclear fixed-chain-length polymerization

    SciTech Connect

    Lin, C.; Kalyuzhnyi, Y.V. |; Stell, G.

    1998-04-01

    A multidensity integral-equation theory for polymerization into freely jointed hard-sphere homonuclear chain fluids proposed earlier [J. Chem. Phys. {bold 106}, 1940 (1997)] is extended to the case of multicomponent heteronuclear chain polymerization. The theory is based on the analytical solution of the polymer Percus{endash}Yevick (PPY) approximation for the totally flexible sticky two-point (S2P) model of associating fluids. The model consists of an n-component mixture of hard spheres of different sizes with species 2,{hor_ellipsis},n{minus}1 bearing two sticky sites A and B, randomly distributed on its surface, and species 1 and n with only one B and A site per particle, respectively. Due to some specific restrictions imposed on the possibility of forming bonds between particles of various species, the present version of the S2P model represents an associating fluid that is able to polymerize into a mixture of heteronuclear chain macromolecules. The structural properties of such a model are studied in the complete-association limit and compared with computer-simulation results for homonuclear hard-sphere chain mixtures, symmetrical diblock copolymers, alternating copolymers, and homonuclear hard-sphere chains in a hard-sphere solvent. Some results for the case of partial association are also presented. The PPY theory represents a quantitatively successful theory for the mixtures of short homonuclear chains and the short copolymer systems studied here. We also expect that the theory will prove to be of the same order of accuracy in investigating the case of partial association. {copyright} {ital 1998 American Institute of Physics.}

  12. Doing Class Analysis in Singapore's Elite Education: Unravelling the Smokescreen of "Meritocratic Talk"

    ERIC Educational Resources Information Center

    Koh, Aaron

    2014-01-01

    This paper examines the specificity of the education-class nexus in an elite independent school in Singapore. It seeks to unravel the puzzle that meritocracy is dogmatically believed in Singapore in spite of evidences that point to the contrary. The paper draws on discursive (analysis of media materials) and institutional (analysis of interview…

  13. Alarm points for fixed oxygen monitors

    SciTech Connect

    Miller, G.C.

    1987-05-01

    Oxygen concentration monitors were installed in a vault where numerous pipes carried inert cryogens and gases to the Mirror Fusion Test Facility (MFTF-B) experimental vessel at Lawrence Livermore National Laboratory (LLNL). The problems associated with oxygen-monitoring systems and the reasons why such monitors were installed were reviewed. As a result of this review, the MFTF-B monitors were set to sound an evacuation alarm when the oxygen concentration fell below 18%. We chose the 18% alarm criterion to minimize false alarms and to allow time for personnel to escape in an oxygen-deficient environment.

  14. Final report on EURAMET.T-K3.1: Bilateral comparison of the realisations of the ITS-90 at the fixed points of Hg, H2O, Ga, Sn and Zn

    NASA Astrophysics Data System (ADS)

    Nedialkov, Sasho; Bosma, Rien; Dierikx, Erik

    2013-01-01

    A bilateral comparison has been organized between VSL, The Netherlands, and BIM, Bulgaria, of the realisations of the international temperature scale ITS-90 at the fixed points of Hg, H2O, Ga, In, Sn and Zn using a long-stem SPRT of very good stability as the transfer device. This comparison is registered as EURAMET project T-K3.1 in the BIPM key comparison database and its results are linked to those of key comparison CCT-K3. This comparison was organized in the framework of Phare project BG 2005/017-353.02.02, Lot 1, and is in this framework financed by the EU. This project ran from March 2008 to the end of February 2009. For all points of the measurements, a good agreement between the results obtained by BIM and in CCT-K3 could be demonstrated. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  15. Algorithmic-Reducibility = Renormalization-Group Fixed-Points; ``Noise''-Induced Phase-Transitions (NITs) to Accelerate Algorithmics (``NIT-Picking'') Replacing CRUTCHES!!!: Gauss Modular/Clock-Arithmetic Congruences = Signal X Noise PRODUCTS..

    NASA Astrophysics Data System (ADS)

    Siegel, J.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Cook-Levin computational-"complexity"(C-C) algorithmic-equivalence reduction-theorem reducibility equivalence to renormalization-(semi)-group phase-transitions critical-phenomena statistical-physics universality-classes fixed-points, is exploited with Gauss modular/clock-arithmetic/model congruences = signal X noise PRODUCT reinterpretation. Siegel-Baez FUZZYICS=CATEGORYICS(SON of ``TRIZ''): Category-Semantics(C-S) tabular list-format truth-table matrix analytics predicts and implements "noise"-induced phase-transitions (NITs) to accelerate versus to decelerate Harel [Algorithmics(1987)]-Sipser[Intro. Theory Computation(1997) algorithmic C-C: "NIT-picking" to optimize optimization-problems optimally(OOPO). Versus iso-"noise" power-spectrum quantitative-only amplitude/magnitude-only variation stochastic-resonance, this "NIT-picking" is "noise" power-spectrum QUALitative-type variation via quantitative critical-exponents variation. Computer-"science" algorithmic C-C models: Turing-machine, finite-state-models/automata, are identified as early-days once-workable but NOW ONLY LIMITING CRUTCHES IMPEDING latter-days new-insights!!!

  16. Unraveling photosystems. Final technical report

    SciTech Connect

    1997-09-01

    This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 leads to the activation of the cryptic psbG2 gene. The genes psbG1 and psbG2 in cyanobacterium Synechocystis sp. PCC 6803 are homologous. The psbG1 gene is located on the chromosome and is part of the ndhC-psbG1-ORF157 operon, while psbG2 is located on a plasmid and is not flanked by equivalent ndhC or ORF157 genes. (4) Deletion of the structural gene for the NADH-dehydrogenase subunit 4 of Synechocystis 6803 alters respiratory properties. Chloroplasts and cyanobacteria contain genes encoding polypeptides homologous to some subunits of the mitochondrial respiratory NADH-ubiquinol oxidoreductase complex (NADH dehydrogenase). Nothing is known of the role of the NADH dehydrogenase complex in photosynthesis, respiration, or other functions in chloroplasts, and little is known about their specific roles in the perhaps 42 subunits of this complex in the mitochondrion.

  17. Full and partial gauge fixing

    SciTech Connect

    Shirzad, A.

    2007-08-15

    Gauge fixing may be done in different ways. We show that using the chain structure to describe a constrained system enables us to use either a full gauge, in which all gauged degrees of freedom are determined, or a partial gauge, in which some first class constraints remain as subsidiary conditions to be imposed on the solutions of the equations of motion. We also show that the number of constants of motion depends on the level in a constraint chain in which the gauge fixing condition is imposed. The relativistic point particle, electromagnetism, and the Polyakov string are discussed as examples and full or partial gauges are distinguished.

  18. Toward Unraveling the Photochemistry of TATB

    SciTech Connect

    Schmidt, R.; Overturf, G.; Watkins, B.; Fried, L.

    1999-11-02

    A combined theoretical and experimental chemical analysis has been conducted to unravel the mechanism underlying the color change of yellow TATB (1,3,5 triamino-trinitro-benzene) to green upon UV irradiation. There is strong evidence to conclude that the process is photochemical in nature and due to the formation of the mono nitroso derivative. They have identified a chemical synthesis by which this derivative compound can be produced in the laboratory, thus allowing for direct testing and determination of its chemical and physical properties. Calculations also show only a slight decrease in the sensitivity and performance of the irradiated materials, attributed to the formation of this previously unidentified species.

  19. Unraveling Flow Patterns through Nonlinear Manifold Learning

    PubMed Central

    Tauro, Flavia; Grimaldi, Salvatore; Porfiri, Maurizio

    2014-01-01

    From climatology to biofluidics, the characterization of complex flows relies on computationally expensive kinematic and kinetic measurements. In addition, such big data are difficult to handle in real time, thereby hampering advancements in the area of flow control and distributed sensing. Here, we propose a novel framework for unsupervised characterization of flow patterns through nonlinear manifold learning. Specifically, we apply the isometric feature mapping (Isomap) to experimental video data of the wake past a circular cylinder from steady to turbulent flows. Without direct velocity measurements, we show that manifold topology is intrinsically related to flow regime and that Isomap global coordinates can unravel salient flow features. PMID:24614890

  20. Unraveling the Miswired Connectome: A Developmental Perspective

    PubMed Central

    Di Martino, Adriana; Fair, Damien A.; Kelly, Clare; Satterthwaite, Theodore D.; Castellanos, F. Xavier; Thomason, Moriah E.; Craddock, R. Cameron; Luna, Beatriz; Leventhal, Bennett L.; Zuo, Xi-Nian; Milham, Michael P.

    2014-01-01

    Summary The vast majority of mental illnesses can be conceptualized as developmental disorders of neural interactions within the connectome, or developmental miswiring. The recent maturation of pediatric in vivo brain imaging is bringing within reach the identification of clinically meaningful brain-based biomarkers of developmental disorders. Even more auspicious, is the ability to study the evolving connectome throughout life, beginning in utero, which promises to move the field from topological phenomenology to etiological nosology. Here, we scope advances in pediatric imaging of the brain connectome as the field faces the challenge of unraveling developmental miswiring. We highlight promises while also providing a pragmatic review of the many obstacles ahead that must be overcome to significantly impact public health. PMID:25233316

  1. Unraveling the miswired connectome: a developmental perspective.

    PubMed

    Di Martino, Adriana; Fair, Damien A; Kelly, Clare; Satterthwaite, Theodore D; Castellanos, F Xavier; Thomason, Moriah E; Craddock, R Cameron; Luna, Beatriz; Leventhal, Bennett L; Zuo, Xi-Nian; Milham, Michael P

    2014-09-17

    The vast majority of mental illnesses can be conceptualized as developmental disorders of neural interactions within the connectome, or developmental miswiring. The recent maturation of pediatric in vivo brain imaging is bringing the identification of clinically meaningful brain-based biomarkers of developmental disorders within reach. Even more auspicious is the ability to study the evolving connectome throughout life, beginning in utero, which promises to move the field from topological phenomenology to etiological nosology. Here, we scope advances in pediatric imaging of the brain connectome as the field faces the challenge of unraveling developmental miswiring. We highlight promises while also providing a pragmatic review of the many obstacles ahead that must be overcome to significantly impact public health. PMID:25233316

  2. Geometric phase for open quantum systems and stochastic unravelings

    SciTech Connect

    Bassi, Angelo; Ippoliti, Emiliano

    2006-06-15

    We analyze the geometric phase for an open quantum system when computed by resorting to a stochastic unraveling of the reduced density matrix (quantum jump approach or stochastic Schroedinger equations). We show that the resulting phase strongly depends on the type of unraveling used for the calculations: as such, this phase is not a geometric object since it depends on nonphysical parameters, which are not related to the path followed by the density matrix during the evolution of the system.

  3. Unraveling the complex metabolic nature of astrocytes

    PubMed Central

    Bouzier-Sore, Anne-Karine; Pellerin, Luc

    2013-01-01

    Since the initial description of astrocytes by neuroanatomists of the nineteenth century, a critical metabolic role for these cells has been suggested in the central nervous system. Nonetheless, it took several technological and conceptual advances over many years before we could start to understand how they fulfill such a role. One of the important and early recognized metabolic function of astrocytes concerns the reuptake and recycling of the neurotransmitter glutamate. But the description of this initial property will be followed by several others including an implication in the supply of energetic substrates to neurons. Indeed, despite the fact that like most eukaryotic non-proliferative cells, astrocytes rely on oxidative metabolism for energy production, they exhibit a prominent aerobic glycolysis capacity. Moreover, this unusual metabolic feature was found to be modulated by glutamatergic activity constituting the initial step of the neurometabolic coupling mechanism. Several approaches, including biochemical measurements in cultured cells, genetic screening, dynamic cell imaging, nuclear magnetic resonance spectroscopy and mathematical modeling, have provided further insights into the intrinsic characteristics giving rise to these key features of astrocytes. This review will provide an account of the different results obtained over several decades that contributed to unravel the complex metabolic nature of astrocytes that make this cell type unique. PMID:24130515

  4. Unraveling Researcher Subjectivity through Multivocality in Autoethnography

    ERIC Educational Resources Information Center

    Mizzi, Robert

    2010-01-01

    This article analyzes and discusses the notion of including multivocality as an autoethnographic method to: (a) illustrate that there is no single and temporally-fixed voice that a researcher possesses, (b) unfix identity in a way that exposes the fluid nature of identity as it moves through particular contexts, and (c) deconstruct competing…

  5. [Advantages of fixed combinations].

    PubMed

    Lachkar, Y

    2008-07-01

    Fixed combinations are indicated in the treatment of glaucoma and ocular hypertension when monotherapy does not sufficiently reduce IOP. Fixed combinations show better efficacy than the instillation of each separate component and are at least equivalent to the administration of both components in a separate association. They simplify treatment, increase compliance and quality of life, and decrease exposure to preservatives. Although they are less aggressive for patients when a new drug needs to be added, the use of fixed combinations should not decrease the follow-up. PMID:18957922

  6. Unravelling the chemical characteristics of YSOs

    NASA Astrophysics Data System (ADS)

    van Dishoeck, Ewine F.

    1999-10-01

    The formation of stars is accompanied by orders of magnitude changes in the physical conditions, with densities in the envelopes and disks increasing from 104 cm-3 to > 1013 cm-3 and temperatures from ~ 10 K in the cold quiescent gas to 10,000 K in shocked regions. The abundances and excitation of the various molecules respond to these changes, and are therefore excellent probes of the physical evolution of YSOs. Moreover, a comprehensive inventory of the chemical composition of envelopes and disks at different evolutionary stages is essential to study the chemistry of matter as it is incorporated into new solar systems. Recent observations of the envelopes of YSOs using single-dish telescopes and millimeter interferometers clearly reveal the potential of submillimeter lines to probe these physical and chemical changes. However, the existing data generally lack the spatial resolution to separate the different physical components, such as the warm inner envelope or `hot core', the region of interaction of the outflow with the envelope and any possible circumstellar disk. ALMA will be essential to provide an `unblurred' view of the YSO environment and unravel the chemical evolution during star formation. In this talk, an overview will be given of recent single-dish and interferometer results of the chemistry in the envelopes and disks around low- and high-mass young stellar objects. Together with ISO data on solid-state material, these observations lead to a chemical scenario in which both gas-phase and gas-grain chemistry (in particular freeze-out and evaporation) play an important role. The evaporated molecules drive a rich chemistry in the warm gas, which can result in complex organic molecules. The potential of ALMA to test chemical theories and determine the composition of gas and dust as it enters forming planetary systems will be illustrated.

  7. Future Fixed Target Facilities

    SciTech Connect

    Melnitchouk, Wolodymyr

    2009-01-01

    We review plans for future fixed target lepton- and hadron-scattering facilities, including the 12 GeV upgraded CEBAF accelerator at Jefferson Lab, neutrino beam facilities at Fermilab, and the antiproton PANDA facility at FAIR. We also briefly review recent theoretical developments which will aid in the interpretation of the data expected from these facilities.

  8. Fixing Dataset Search

    NASA Technical Reports Server (NTRS)

    Lynnes, Chris

    2014-01-01

    Three current search engines are queried for ozone data at the GES DISC. The results range from sub-optimal to counter-intuitive. We propose a method to fix dataset search by implementing a robust relevancy ranking scheme. The relevancy ranking scheme is based on several heuristics culled from more than 20 years of helping users select datasets.

  9. Unraveling "Braid": Puzzle Games and Storytelling in the Imperative Mood

    ERIC Educational Resources Information Center

    Arnott, Luke

    2012-01-01

    "Unraveling Braid" analyzes how unconventional, non-linear narrative fiction can help explain the ways in which video games signify. Specifically, this essay looks at the links between the semiotic features of Jonathan Blow's 2008 puzzle-platform video game Braid and similar elements in Georges Perec's 1978 novel "Life A User's Manual," as well as…

  10. Unraveling of a detailed-balance-preserved quantum master equation and continuous feedback control of a measured qubit

    NASA Astrophysics Data System (ADS)

    Luo, JunYan; Jin, Jinshuang; Wang, Shi-Kuan; Hu, Jing; Huang, Yixiao; He, Xiao-Ling

    2016-03-01

    We present a generic unraveling scheme for a detailed-balance-preserved quantum master equation applicable for stochastic point processes in mesoscopic transport. It enables us to investigate continuous measurement of a qubit on the level of single quantum trajectories, where essential correlations between the inherent dynamics of the qubit and detector current fluctuations are revealed. Based on this unraveling scheme, feedback control of the charge qubit is implemented to achieve a desired pure state in the presence of the detailed-balance condition. With sufficient feedback strength, coherent oscillations of the measured qubit can be maintained for arbitrary qubit-detector coupling. Competition between the loss and restoration of coherence entailed, respectively, by measurement back action and feedback control is reflected in the noise power spectrum of the detector's output. It is demonstrated unambiguously that the signal-to-noise ratio is significantly enhanced with increasing feedback strength and could even exceed the well-known Korotkov-Averin bound in quantum measurement. The proposed unraveling and feedback scheme offers a transparent and straightforward approach to effectively sustaining ideal coherent oscillations of a charge qubit in the field of quantum computation.

  11. Fixed target facility at the SSC

    SciTech Connect

    Loken, S.C.; Morfin, J.G.

    1985-01-01

    The question of whether a facility for fixed target physics should be provided at the SSC must be answered before the final technical design of the SSC can be completed, particularly if the eventual form of extraction would influence the magnet design. To this end, an enthusiastic group of experimentalists, theoreticians and accelerator specialists have studied this point. The accelerator physics issues were addressed by a group led by E. Colton whose report is contained in these proceedings. The physics addressable by fixed target was considered by many of the Physics area working groups and in particular by the Structure Function Group. This report is the summary of the working group which considered various SSC fixed target experiments and determined which types of beams and detectors would be required. 13 references, 5 figures.

  12. THE DYNAMICS OF CATEGORIZATION: UNRAVELING RAPID CATEGORIZATION

    PubMed Central

    Mack, Michael L.; Palmeri, Thomas J.

    2015-01-01

    We explore a puzzle of visual object categorization: Under normal viewing conditions, you spot something as a dog fastest, but at a glance, you spot it faster as an animal. During speeded category verification, a classic basic-level advantage is commonly observed (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976), with categorization as a dog faster than as an animal (superordinate) or Golden Retriever (subordinate). A different story emerges during ultra-rapid categorization with limited exposure duration (<30ms), with superordinate categorization faster than basic or subordinate categorization (Thorpe, Fize, & Marlot, 1996). These two widely cited findings paint contrary theoretical pictures about the time course of object categorization, yet no study has previously investigated them together. Over five experiments, we systematically examined two experimental factors that could explain the qualitative difference in categorization across the two paradigms: exposure duration and category trial context. Mapping out the time course of object categorization by manipulating exposure duration and the timing of a post-stimulus mask revealed that brief exposure durations favor superordinate-level categorization, but with more time a basic-level advantage emerges. But this superordinate advantage was modulated significantly by target category trial context. With randomized target categories, the superordinate advantage was eliminated; and with “blocks” of only four repetitions of superordinate categorization within an otherwise randomized context, the advantage for the basic-level was eliminated. Contrary to some theoretical accounts that dictate a fixed priority for certain levels of abstraction in visual processing and access to semantic knowledge, the dynamics of object categorization are flexible, depending jointly on the level of abstraction, time for perceptual encoding, and category context. PMID:25938178

  13. 22. VIEW OF FIXED SPAN SUBSTRUCTURE, EAST SPAN, SHOWING CANTILEVEREDBEAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. VIEW OF FIXED SPAN SUBSTRUCTURE, EAST SPAN, SHOWING CANTILEVERED-BEAM SIDEWALK SUPPORTS, LONGITUDINAL GIRDER AND TRANSVERSE ROADBED BEAMS, LOOKING SOUTHEAST - Congress Street Bascule Bridge, Spanning Fort Point Channel at Congress Street, Boston, Suffolk County, MA

  14. Fixed and Sunk Costs Revisited.

    ERIC Educational Resources Information Center

    Wang, X. Henry; Yang, Bill Z.

    2001-01-01

    Attempts to clarify the concepts of, and the link between, fixed costs and sunk costs. Argues that the root of confusion is the inconsistency in defining the term fixed costs. Consistently defines fixed and sunk costs, and describes how instructors must teach under these definitions. (RLH)

  15. Unraveling liver complexity from molecular to organ level: challenges and perspectives.

    PubMed

    D'Alessandro, L A; Hoehme, S; Henney, A; Drasdo, D; Klingmüller, U

    2015-01-01

    Biological responses are determined by information processing at multiple and highly interconnected scales. Within a tissue the individual cells respond to extracellular stimuli by regulating intracellular signaling pathways that in turn determine cell fate decisions and influence the behavior of neighboring cells. As a consequence the cellular responses critically impact tissue composition and architecture. Understanding the regulation of these mechanisms at different scales is key to unravel the emergent properties of biological systems. In this perspective, a multidisciplinary approach combining experimental data with mathematical modeling is introduced. We report the approach applied within the Virtual Liver Network to analyze processes that regulate liver functions from single cell responses to the organ level using a number of examples. By facilitating interdisciplinary collaborations, the Virtual Liver Network studies liver regeneration and inflammatory processes as well as liver metabolic functions at multiple scales, and thus provides a suitable example to identify challenges and point out potential future application of multi-scale systems biology. PMID:25433231

  16. Unravelling emotional viewpoints on a bio-based economy using Q methodology.

    PubMed

    Sleenhoff, Susanne; Cuppen, Eefje; Osseweijer, Patricia

    2015-10-01

    A transition to a bio-based economy will affect society and requires collective action from a broad range of stakeholders. This includes the public, who are largely unaware of this transition. For meaningful public engagement people's emotional viewpoints play an important role. However, what the public's emotions about the transition are and how they can be taken into account is underexposed in public engagement literature and practice. This article aims to unravel the public's emotional views of the bio-based economy as a starting point for public engagement. Using Q methodology with visual representations of a bio-based economy we found four emotional viewpoints: (1) compassionate environmentalist, (2) principled optimist, (3) hopeful motorist and (4) cynical environmentalist. These provide insight into the distinct and shared ways through which members of the public connect with the transition. Implications for public engagement are discussed. PMID:24928568

  17. From fixed points to chaos: three models of delayed discrimination.

    PubMed

    Barak, Omri; Sussillo, David; Romo, Ranulfo; Tsodyks, Misha; Abbott, L F

    2013-04-01

    Working memory is a crucial component of most cognitive tasks. Its neuronal mechanisms are still unclear despite intensive experimental and theoretical explorations. Most theoretical models of working memory assume both time-invariant neural representations and precise connectivity schemes based on the tuning properties of network neurons. A different, more recent class of models assumes randomly connected neurons that have no tuning to any particular task, and bases task performance purely on adjustment of network readout. Intermediate between these schemes are networks that start out random but are trained by a learning scheme. Experimental studies of a delayed vibrotactile discrimination task indicate that some of the neurons in prefrontal cortex are persistently tuned to the frequency of a remembered stimulus, but the majority exhibit more complex relationships to the stimulus that vary considerably across time. We compare three models, ranging from a highly organized line attractor model to a randomly connected network with chaotic activity, with data recorded during this task. The random network does a surprisingly good job of both performing the task and matching certain aspects of the data. The intermediate model, in which an initially random network is partially trained to perform the working memory task by tuning its recurrent and readout connections, provides a better description, although none of the models matches all features of the data. Our results suggest that prefrontal networks may begin in a random state relative to the task and initially rely on modified readout for task performance. With further training, however, more tuned neurons with less time-varying responses should emerge as the networks become more structured. PMID:23438479

  18. Using a Card Trick to Illustrate Fixed Points and Stability

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti; Jani, Mahendra

    2015-01-01

    Mathematical ideas from number theory, group theory, dynamical systems, and computer science have often been used to explain card tricks. Conversely, playing cards have been often used to illustrate the mathematical concepts of probability distributions and group theory. In this paper, we describe how the 21-card trick may be used to illustrate…

  19. Apparatus for fixing latency

    DOEpatents

    Hall, David R.; Bartholomew, David B.; Moon, Justin; Koehler, Roger O.

    2009-09-08

    An apparatus for fixing computational latency within a deterministic region on a network comprises a network interface modem, a high priority module and at least one deterministic peripheral device. The network interface modem is in communication with the network. The high priority module is in communication with the network interface modem. The at least one deterministic peripheral device is connected to the high priority module. The high priority module comprises a packet assembler/disassembler, and hardware for performing at least one operation. Also disclosed is an apparatus for executing at least one instruction on a downhole device within a deterministic region, the apparatus comprising a control device, a downhole network, and a downhole device. The control device is near the surface of a downhole tool string. The downhole network is integrated into the tool string. The downhole device is in communication with the downhole network.

  20. [Fixed-dose combination].

    PubMed

    Nagai, Yoshio

    2015-03-01

    Many patients with type 2 diabetes mellitus(T2DM) do not achieve satisfactory glycemic control by monotherapy alone, and often require multiple oral hypoglycemic agents (OHAs). Combining OHAs with complementary mechanisms of action is fundamental to the management of T2DM. Fixed-dose combination therapy(FDC) offers a method of simplifying complex regimens. Efficacy and tolerability appear to be similar between FDC and treatment with individual agents. In addition, FDC can enhance adherence and improved adherence may result in improved glycemic control. Four FDC agents are available in Japan: pioglitazone-glimepiride, pioglitazone-metformin, pioglitazone-alogliptin, and voglibose-mitiglinide. In this review, the advantages and disadvantages of these four combinations are identified and discussed. PMID:25812374

  1. Fixed Access Network Sharing

    NASA Astrophysics Data System (ADS)

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  2. 47 CFR 22.591 - Channels for point-to-point operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Channels for point-to-point operation. 22.591... PUBLIC MOBILE SERVICES Paging and Radiotelephone Service Point-To-Point Operation § 22.591 Channels for point-to-point operation. The following channels are allocated for assignment to fixed transmitters...

  3. 47 CFR 22.591 - Channels for point-to-point operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Channels for point-to-point operation. 22.591... PUBLIC MOBILE SERVICES Paging and Radiotelephone Service Point-To-Point Operation § 22.591 Channels for point-to-point operation. The following channels are allocated for assignment to fixed transmitters...

  4. Unraveling Executive Functioning in Dual Diagnosis.

    PubMed

    Duijkers, Judith C L M; Vissers, Constance Th W M; Egger, Jos I M

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in daily life. Thus, several aspects of executive functioning like inhibitory, shifting and updating processes seem impaired in dual-diagnosis. Executive (dys-)function is currently even seen as a shared underlying key component of most mental disorders. However, the number of studies on diverse aspects of executive functioning in dual-diagnosis is limited. In the present review, a systematic overview of various aspects of executive functioning in dual-diagnosis is presented, striving for a prototypical profile of patients with dual-diagnosis. Looking at empirical results, inhibitory and shifting processes appear to be impaired for SUD combined with schizophrenia, bipolar disorder or cluster B personality disorders. Studies involving updating process tasks for dual-diagnosis were limited. More research that zooms in to the full diversity of these executive functions is needed in order to strengthen these findings. Detailed insight in the profile of strengths and weaknesses that underlies one's behavior and is related to diagnostic classifications, can lead to tailor-made assessment and indications for treatment, pointing out which aspects need attention and/or training in one's self-regulative abilities. PMID:27445939

  5. Unraveling Executive Functioning in Dual Diagnosis

    PubMed Central

    Duijkers, Judith C. L. M.; Vissers, Constance Th. W. M.; Egger, Jos I. M.

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other’s expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in daily life. Thus, several aspects of executive functioning like inhibitory, shifting and updating processes seem impaired in dual-diagnosis. Executive (dys-)function is currently even seen as a shared underlying key component of most mental disorders. However, the number of studies on diverse aspects of executive functioning in dual-diagnosis is limited. In the present review, a systematic overview of various aspects of executive functioning in dual-diagnosis is presented, striving for a prototypical profile of patients with dual-diagnosis. Looking at empirical results, inhibitory and shifting processes appear to be impaired for SUD combined with schizophrenia, bipolar disorder or cluster B personality disorders. Studies involving updating process tasks for dual-diagnosis were limited. More research that zooms in to the full diversity of these executive functions is needed in order to strengthen these findings. Detailed insight in the profile of strengths and weaknesses that underlies one’s behavior and is related to diagnostic classifications, can lead to tailor-made assessment and indications for treatment, pointing out which aspects need attention and/or training in one’s self-regulative abilities. PMID:27445939

  6. Unraveling multiple changes in complex climate time series using Bayesian inference

    NASA Astrophysics Data System (ADS)

    Berner, Nadine; Trauth, Martin H.; Holschneider, Matthias

    2016-04-01

    Change points in time series are perceived as heterogeneities in the statistical or dynamical characteristics of observations. Unraveling such transitions yields essential information for the understanding of the observed system. The precise detection and basic characterization of underlying changes is therefore of particular importance in environmental sciences. We present a kernel-based Bayesian inference approach to investigate direct as well as indirect climate observations for multiple generic transition events. In order to develop a diagnostic approach designed to capture a variety of natural processes, the basic statistical features of central tendency and dispersion are used to locally approximate a complex time series by a generic transition model. A Bayesian inversion approach is developed to robustly infer on the location and the generic patterns of such a transition. To systematically investigate time series for multiple changes occurring at different temporal scales, the Bayesian inversion is extended to a kernel-based inference approach. By introducing basic kernel measures, the kernel inference results are composed into a proxy probability to a posterior distribution of multiple transitions. Thus, based on a generic transition model a probability expression is derived that is capable to indicate multiple changes within a complex time series. We discuss the method's performance by investigating direct and indirect climate observations. The approach is applied to environmental time series (about 100 a), from the weather station in Tuscaloosa, Alabama, and confirms documented instrumentation changes. Moreover, the approach is used to investigate a set of complex terrigenous dust records from the ODP sites 659, 721/722 and 967 interpreted as climate indicators of the African region of the Plio-Pleistocene period (about 5 Ma). The detailed inference unravels multiple transitions underlying the indirect climate observations coinciding with established

  7. Cook-Levin Theorem Algorithmic-Reducibility/Completeness = Wilson Renormalization-(Semi)-Group Fixed-Points; ``Noise''-Induced Phase-Transitions (NITs) to Accelerate Algorithmics (``NIT-Picking'') REPLACING CRUTCHES!!!: Models: Turing-machine, finite-state-models, finite-automata

    NASA Astrophysics Data System (ADS)

    Young, Frederic; Siegel, Edward

    Cook-Levin theorem theorem algorithmic computational-complexity(C-C) algorithmic-equivalence reducibility/completeness equivalence to renormalization-(semi)-group phase-transitions critical-phenomena statistical-physics universality-classes fixed-points, is exploited via Siegel FUZZYICS =CATEGORYICS = ANALOGYICS =PRAGMATYICS/CATEGORY-SEMANTICS ONTOLOGY COGNITION ANALYTICS-Aristotle ``square-of-opposition'' tabular list-format truth-table matrix analytics predicts and implements ''noise''-induced phase-transitions (NITs) to accelerate versus to decelerate Harel [Algorithmics (1987)]-Sipser[Intro.Thy. Computation(`97)] algorithmic C-C: ''NIT-picking''(!!!), to optimize optimization-problems optimally(OOPO). Versus iso-''noise'' power-spectrum quantitative-only amplitude/magnitude-only variation stochastic-resonance, ''NIT-picking'' is ''noise'' power-spectrum QUALitative-type variation via quantitative critical-exponents variation. Computer-''science''/SEANCE algorithmic C-C models: Turing-machine, finite-state-models, finite-automata,..., discrete-maths graph-theory equivalence to physics Feynman-diagrams are identified as early-days once-workable valid but limiting IMPEDING CRUTCHES(!!!), ONLY IMPEDE latter-days new-insights!!!

  8. Inhibitory Avoidance Learning in Zebrafish (Danio Rerio): Effects of Shock Intensity and Unraveling Differences in Task Performance

    PubMed Central

    Gorissen, Marnix; Piza Roca, Carme; Zethof, Jan; van de Vis, Hans; Flik, Gert; van den Bos, Ruud

    2014-01-01

    Abstract The zebrafish (Danio rerio) is increasingly used as a model in neurobehavioral and neuroendocrine studies. The inhibitory avoidance paradigm has been proposed as tool to study mechanisms underlying learning and memory in zebrafish. In this paradigm subjects receive a shock after entering the black compartment of a black-white box. On the next day, latency to enter the black compartment is assessed; higher latencies are indicative of increased avoidance learning. Here, we aimed to understand the effects of different shock intensities (0, 1, 3, and 9 V) and to unravel variation in inhibitory avoidance learning in an in-house reared Tuebingen Long-Fin zebrafish (D. rerio) strain. While median latencies had increased in the 1, 3, and 9 V groups, no increase in median latency was found in the 0 V group. In addition, higher shock intensities resulted in a higher number of avoiders (latency ≥180 s) over nonavoiders (latency <60 s). Both changes are indicative of increased avoidance learning. We assessed whole-body cortisol content and the expression levels of genes relevant to stress, anxiety, fear, and learning 2 h after testing. Shock intensity was associated with whole-body cortisol content and the expression of glucocorticoid receptor alpha [nr3c1(alpha)], cocaine- and amphetamine-regulated transcript (cart4), and mineralocorticoid receptor (nr3c2), while avoidance behavior was associated with whole-body cortisol content only. The inhibitory avoidance paradigm in combination with measuring whole-body cortisol content and gene expression is suitable to unravel (genetic) mechanisms of fear avoidance learning. Our data further show differences in brain-behavior relationships underlying fear avoidance learning and memory in zebrafish. These findings serve as starting point for further unraveling differences in brain-behavior relationships underlying (fear avoidance) learning and memory in zebrafish. PMID:25004302

  9. Systems biology unravels interferon responses to respiratory virus infections

    PubMed Central

    Kroeker, Andrea L; Coombs, Kevin M

    2014-01-01

    Interferon production is an important defence against viral replication and its activation is an attractive therapeutic target. However, it has long been known that viruses perpetually evolve a multitude of strategies to evade these host immune responses. In recent years there has been an explosion of information on virus-induced alterations of the host immune response that have resulted from data-rich omics technologies. Unravelling how these systems interact and determining the overall outcome of the host response to viral infection will play an important role in future treatment and vaccine development. In this review we focus primarily on the interferon pathway and its regulation as well as mechanisms by which respiratory RNA viruses interfere with its signalling capacity. PMID:24600511

  10. Unraveling heavy oil desulfurization chemistry: targeting clean fuels.

    PubMed

    Choudhary, Tushar V; Parrott, Stephen; Johnson, Byron

    2008-03-15

    The sulfur removal chemistry of heavy oils has been unraveled by systematically investigating several heavy oils with an extremely wide range of properties. The heavy oil feed and product properties have been characterized by advanced analytical methods, and these properties have been related to the sulfur conversion data observed in pilot hydrotreating units. These studies coupled with kinetic treatment of the data have revealed that the desulfurization chemistry of heavy oils is essentially controlled by the strongly inhibiting three and larger ring aromatic hydrocarbon content and surprisingly not by the content of the "hard-to-remove" sulfur compounds. Such enhanced understanding of the heavy oil sulfur removal is expected to open new avenues for catalyst/process optimization for heavy oil desulfurization and thereby assist the efficent production of clean transporation fuels. PMID:18409618

  11. Dyspraxia or developmental coordination disorder? Unravelling the enigma.

    PubMed

    Gibbs, John; Appleton, Jeanette; Appleton, Richard

    2007-06-01

    Dyspraxia is an enigma to many people, both professional and lay alike--what is it, how does it relate to developmental coordination disorder and associated conditions, how common is it, how is it recognised and diagnosed and how should it be managed? This article attempts to unravel this enigma by: dealing with the terminology of coordination difficulties from the "clumsy child syndrome" through "dyspraxia" to "developmental coordination disorder (DCD)"; briefly examining the debate as to whether dyspraxia or DCD should be regarded as a medical or social disorder; discussing the differential diagnosis of dyspraxia or DCD; considering the assessment of children with dyspraxia or DCD; reviewing the range of current treatment approaches in the UK. PMID:17515623

  12. Dyspraxia or developmental coordination disorder? Unravelling the enigma

    PubMed Central

    Gibbs, John; Appleton, Jeanette; Appleton, Richard

    2007-01-01

    Dyspraxia is an enigma to many people, both professional and lay alike—what is it, how does it relate to developmental coordination disorder and associated conditions, how common is it, how is it recognised and diagnosed and how should it be managed? This article attempts to unravel this enigma by: dealing with the terminology of coordination difficulties from the “clumsy child syndrome” through “dyspraxia” to “developmental coordination disorder (DCD)”; briefly examining the debate as to whether dyspraxia or DCD should be regarded as a medical or social disorder; discussing the differential diagnosis of dyspraxia or DCD; considering the assessment of children with dyspraxia or DCD; reviewing the range of current treatment approaches in the UK. PMID:17515623

  13. Funding human services: fixed utility versus fixed budget.

    PubMed

    McCready, D J; Rahn, S L

    1986-01-01

    It is argued in this paper that government allocations for human services based on inputs rather than outcomes, reduce efficiency in social and health service provision. An alternative system of budgeting or contracting on the basis of cost-per-closed case and case outcome is discussed. An interdependency between fixed budget and fixed utility models of allocation is affirmed. The locus of decision-making for operationalizing this interdependency is seen as the program and budget review panel to which operating agencies and government departments must submit financial and program accounting information from year to year. In isolation, the fixed budget approach degenerates into routine allocation or contract renewal with a focus on such input and output variables as volume of service and unit cost, and the fixed utility approach, into political stalemate. Simulated examples are given to demonstrate how allocation on the basis of inputs and outputs alone provides an incentive to inefficiency, and a fixed utility orientation to efficiency. PMID:10311890

  14. Procrastination by pigeons with fixed-interval response requirements.

    PubMed

    Mazur, J E

    1998-03-01

    Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

  15. Procrastination by pigeons with fixed-interval response requirements.

    PubMed Central

    Mazur, J E

    1998-01-01

    Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

  16. Evidence of the big fix

    NASA Astrophysics Data System (ADS)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2014-06-01

    We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value vh. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self-coupling are fixed when we vary vh. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental law in our case.

  17. The Double Fixed Charge Membrane

    PubMed Central

    Coster, H. G. L.

    1973-01-01

    An analysis is made of the AC characteristics of a membrane consisting of two fixed charge regions of opposite sign, in contact. It is shown that the equivalent parallel capacitance and conductance of such a membrane undergo a strong dispersion at low frequencies. The dielectric dispersion is a result of polarization effects in the diffusion of coions in each of the two fixed charge lattices. This, at low frequencies, gives rise to a very large diffusion capacitance. The form of the dispersion characteristics is very similar to those observed for synthetic-fused anion-cation membranes and various cellular membranes. PMID:4702011

  18. Fixed Costs and Hours Constraints

    ERIC Educational Resources Information Center

    Johnson, William R.

    2011-01-01

    Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

  19. Unravelling the community structure of the climate system by using lags and symbolic time-series analysis

    NASA Astrophysics Data System (ADS)

    Tirabassi, Giulio; Masoller, Cristina

    2016-07-01

    Many natural systems can be represented by complex networks of dynamical units with modular structure in the form of communities of densely interconnected nodes. Unraveling this community structure from observed data requires the development of appropriate tools, particularly when the nodes are embedded in a regular space grid and the datasets are short and noisy. Here we propose two methods to identify communities, and validate them with the analysis of climate datasets recorded at a regular grid of geographical locations covering the Earth surface. By identifying mutual lags among time-series recorded at different grid points, and by applying symbolic time-series analysis, we are able to extract meaningful regional communities, which can be interpreted in terms of large-scale climate phenomena. The methods proposed here are valuable tools for the study of other systems represented by networks of dynamical units, allowing the identification of communities, through time-series analysis of the observed output signals.

  20. Unravelling the community structure of the climate system by using lags and symbolic time-series analysis

    PubMed Central

    Tirabassi, Giulio; Masoller, Cristina

    2016-01-01

    Many natural systems can be represented by complex networks of dynamical units with modular structure in the form of communities of densely interconnected nodes. Unraveling this community structure from observed data requires the development of appropriate tools, particularly when the nodes are embedded in a regular space grid and the datasets are short and noisy. Here we propose two methods to identify communities, and validate them with the analysis of climate datasets recorded at a regular grid of geographical locations covering the Earth surface. By identifying mutual lags among time-series recorded at different grid points, and by applying symbolic time-series analysis, we are able to extract meaningful regional communities, which can be interpreted in terms of large-scale climate phenomena. The methods proposed here are valuable tools for the study of other systems represented by networks of dynamical units, allowing the identification of communities, through time-series analysis of the observed output signals. PMID:27406342

  1. Unravelling the community structure of the climate system by using lags and symbolic time-series analysis.

    PubMed

    Tirabassi, Giulio; Masoller, Cristina

    2016-01-01

    Many natural systems can be represented by complex networks of dynamical units with modular structure in the form of communities of densely interconnected nodes. Unraveling this community structure from observed data requires the development of appropriate tools, particularly when the nodes are embedded in a regular space grid and the datasets are short and noisy. Here we propose two methods to identify communities, and validate them with the analysis of climate datasets recorded at a regular grid of geographical locations covering the Earth surface. By identifying mutual lags among time-series recorded at different grid points, and by applying symbolic time-series analysis, we are able to extract meaningful regional communities, which can be interpreted in terms of large-scale climate phenomena. The methods proposed here are valuable tools for the study of other systems represented by networks of dynamical units, allowing the identification of communities, through time-series analysis of the observed output signals. PMID:27406342

  2. Unraveling Shock-Induced Chemistry Using Ultrafast Lasers

    NASA Astrophysics Data System (ADS)

    Moore, D. S.

    2009-12-01

    The exquisite time synchronicity between shock and diagnostics needed to unravel chemical events occurring in picoseconds has been achieved using a shaped ultrafast laser pulse to both drive the shocks and interrogate the sample via a multiplicity of optical diagnostics. The shaped laser drive pulse can produce well-controlled shock states of sub-ns duration with sub-10 ps rise times, sufficient for investigation of fast reactions or phase transformations in a thin layer with picosecond time resolution. The shock state is characterized using ultrafast dynamic ellipsometry (UDE) in either planar or Gaussian spatial geometries, the latter allowing measurements of the equation of state of materials at a range of stresses in a single laser pulse. Time-resolved processes in materials are being interrogated using UDE, ultrafast infrared absorption, ultrafast UV/visible absorption, and femtosecond stimulated Raman spectroscopy. Using these tools we showed that chemistry in an energetic thin film starts only after an induction time of a few tens of ps, an observation that allows differentiation between proposed shock-induced reaction mechanisms. These tools are presently being applied to a variety of energetic and reactive sample systems, from nitromethane and carbon disulfide, to micro-engineered interfaces in tunable energetic mixtures.

  3. Unraveling shock-induced chemistry using ultrafast lasers

    SciTech Connect

    Moore, David S

    2009-01-01

    The exquisite time synchronicity between shock and diagnostics needed to unravel chemical events occurring in picoseconds has been achieved using a shaped ultrafast laser pulse to both drive the shocks and interrogate the sample via a multiplicity of optical diagnostics. The shaped laser drive pulse can produce well-controlled shock states of sub-ns duration with sub-10 ps risetimes, sufficient for investigation of fast reactions or phase transformations in a thin layer with picosecond time resolution. The shock state is characterized using ultrafast dynamic ellipsometry (UDE) in either planar or Gaussian spatial geometries, the latter allowing measurements of the equation of state of materials at a range of stresses in a single laser pulse. Time-resolved processes in materials are being interrogated using UDE, ultrafast infrared absorption, ultrafast UV/visible absorption, and femtosecond stimulated Raman spectroscopy. Using these tools we showed that chemistry in an energetic thin film starts only after an induction time of a few tens of ps, an observation that allows differentiation between proposed shock-induced reaction mechanisms. These tools are presently being applied to a variety of energetic and reactive sample systems, from nitromethane and carbon disulfide, to micro-engineered interfaces in tunable energetic mixtures.

  4. Uncontrolled immune response in acute myocardial infarction: unraveling the thread.

    PubMed

    Bodi, Vicente; Sanchis, Juan; Nunez, Julio; Mainar, Luis; Minana, Gema; Benet, Isabel; Solano, Carlos; Chorro, Francisco J; Llacer, Angel

    2008-12-01

    Recently, the theory that hyperinflammation is the body's primary response to potent stimulus has been challenged. Indeed, a deregulation of the immune system could be the cause of multiple organ failure. So far, clinicians have focused on the last steps of the inflammatory cascade. However, little attention has been paid to lymphocytes, which play an important role as strategists of the inflammatory response. Experimental evidence suggests a crucial role of T lymphocytes in the pathophysiology of atherosclerosis and acute myocardial infarction (AMI). In summary, from the bottom of an imaginary inverted pyramid, a few regulatory T-cells control the upper parts represented by the wide spectrum of the inflammatory cascade. In AMI, a loss of regulation of the inflammatory system occurs in patients with a decreased activity of regulatory T-cells. As a consequence, aggressive T-cells boost and anti-inflammatory T-cells drop. A pleiotropic proinflammatory imbalance with damaging effects in terms of left ventricular performance and patient outcome is the result of this uncontrolled immune response. It is needed to unravel the thread of the inflammatory cells to better understand the pathophysiology as well as to open innovative therapeutic options in AMI. PMID:19033000

  5. Unraveling shock-induced chemistry using ultrafast lasers

    SciTech Connect

    Moore, David Steven

    2010-12-06

    The exquisite time synchronicity between shock and diagnostics needed to unravel chemical events occurring in picoseconds has been achieved using a shaped ultrafast laser pulse to both drive the shocks and interrogate the sample via a multiplicity of optical diagnostics. The shaped laser drive pulse can produce well-controlled shock states of sub-ns duration with sub-10 ps risetimes, sufficient for investigation offast reactions or phase transformations in a thin layer with picosecond time resolution. The shock state is characterized using ultrafast dynamic ellipsometry (UDE) in either planar or Gaussian spatial geometries, the latter allowing measurements of the equation of state of materials at a range of stresses in a single laser pulse. Time-resolved processes in materials are being interrogated using UDE, ultrafast infrared absorption, ultrafast UV/visible absorption, and femtosecond stimulated Raman spectroscopy. Using these tools we showed that chemistry in an energetic thin film starts only after an induction time of a few tens of ps, an observation that allows differentiation between proposed shock-induced reaction mechanisms. These tools are presently being applied to a variety of energetic and reactive sample systems, from nitromethane and carbon disulfide, to microengineered interfaces in tunable energetic mixtures. Recent results will be presented, and future trends outlined.

  6. Tipping Point

    MedlinePlus Videos and Cool Tools

    ... Tipping Point by CPSC Blogger September 22 appliance child Childproofing CPSC danger death electrical fall furniture head ... TV falls with about the same force as child falling from the third story of a building. ...

  7. Variable delivery, fixed displacement pump

    SciTech Connect

    Sommars, Mark F.

    2001-01-01

    A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

  8. Partial gauge fixing and equivariant cohomology

    NASA Astrophysics Data System (ADS)

    Ferrari, Frank

    2014-05-01

    Given a gauge theory with gauge group G, it is sometimes useful to find an equivalent formulation in terms of a nontrivial gauge subgroup H ⊂G. This amounts to fixing the gauge partially from G down to H. We study this problem systematically, both from the algebraic and from the path integral points of view. We find that the usual BRST cohomology must be replaced by an equivariant version and that the ghost Lagrangian must always include quartic ghost terms, even at tree level. Both the Cartan and Weil models for equivariant cohomology play a role and find natural interpretations within the physics framework. Applications include the construction of D-brane models of emergent space, the 't Hooft Abelian projection scenario in quantum chromodynamics and the formulation of the low-energy effective theories of grand unified models.

  9. Settling of fixed erythrocyte suspension droplets

    NASA Technical Reports Server (NTRS)

    Omenyi, S. N.; Snyder, R. S.

    1983-01-01

    It is pointed out that when particles behave collectively rather than individually, the fractionation of micron-size particles on the basis of size, density, and surface characteristics by centrifugation and electrophoresis is hindered. The formation and sedimentation of droplets containing particles represent an extreme example of collective behavior and pose a major problem for these separation methods when large quantities of particles need to be fractionated. Experiments are described that measure droplet sizes and settling rates for a variety of particles and droplets. Expressions relating the particle concentration in a drop to measurable quantities of the fluids and particles are developed. The number of particles in each droplet is then estimated, together with the effective droplet density. Red blood cells from different animals fixed in glutaraldehyde provide model particle groups.

  10. The triple point of sulfur hexafluoride

    NASA Astrophysics Data System (ADS)

    Rourke, P. M. C.

    2016-04-01

    A cryogenic fixed point cell has been filled with high purity (99.999%) sulfur hexafluoride (SF6) and measured in an adiabatic closed-cycle cryostat system. Temperature measurements of the SF6 melting curve were performed using a capsule-type standard platinum resistance thermometer (CSPRT) calibrated over the International Temperature Scale of 1990 (ITS-90) subrange from the triple point of equilibrium hydrogen to the triple point of water. The measured temperatures were corrected by 0.37 mK for the effects of thermometer self-heating, and the liquidus-point temperature estimated by extrapolation to melted fraction F  =  1 of a simple linear regression versus melted fraction F in the range F  =  0.53 to 0.84. Based on this measurement, the temperature of the triple point of sulfur hexafluoride is shown to be 223.555 23(49) K (k  =  1) on the ITS-90. This value is in excellent agreement with the best prior measurements reported in the literature, but with considerably smaller uncertainty. An analysis of the detailed uncertainty budget of this measurement suggests that if the triple point of sulfur hexafluoride were to be included as a defining fixed point of the next revision of the International Temperature Scale, it could do so with a total realization uncertainty of approximately 0.43 mK, slightly larger than the realization uncertainties of the defining fixed points of the ITS-90. Since the combined standard uncertainty of this SF6 triple point temperature determination is dominated by chemical impurity effects, further research exploring gas purification techniques and the influence of specific impurity species on the SF6 triple point temperature may bring the realization uncertainty of SF6 as a fixed point material into the range of the defining fixed points of the ITS-90.

  11. Unravelling genetics at the top: mountain islands or isolated belts?

    PubMed Central

    García-Fernández, Alfredo; Segarra-Moragues, Jose Gabriel; Widmer, Alex; Escudero, Adrian; Iriondo, José María

    2012-01-01

    Background and Aims In mountain plant populations, local adaptation has been described as one of the main responses to climate warming, allowing plants to persist under stressful conditions. This is especially the case for marginal populations at their lowest elevation, as they are highly vulnerable. Adequate levels of genetic diversity are required for selection to take place, while high levels of altitudinal gene flow are seen as a major limiting factor potentially precluding local adaptation processes. Thus, a compromise between genetic diversity and gene flow seems necessary to guarantee persistence under oncoming conditions. It is therefore critical to determine if gene flow occurs preferentially between mountains at similar altitudinal belts, promoting local adaptation at the lowest populations, or conversely along altitude within each mountain. Methods Microsatellite markers were used to unravel genetic diversity and population structure, inbreeding and gene flow of populations at two nearby altitudinal gradients of Silene ciliata, a Mediterranean high-mountain cushion plant. Key Results Genetic diversity and inbreeding coefficients were similar in all populations. Substantial gene flow was found both along altitudinal gradients and horizontally within each elevation belt, although greater values were obtained along altitudinal gradients. Gene flow may be responsible for the homogeneous levels of genetic diversity found among populations. Bayesian cluster analyses also suggested that shifts along altitudinal gradients are the most plausible scenario. Conclusions Past population shifts associated with glaciations and interglacial periods in temperate mountains may partially explain current distributions of genetic diversity and population structure. In spite of the predominance of gene flow along the altitudinal gradients, local genetic differentiation of one of the lower populations together with the detection of one outlier locus might support the existence

  12. 47 CFR 74.644 - Minimum path lengths for fixed links.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Minimum path lengths for fixed links. 74.644... Auxiliary Stations § 74.644 Minimum path lengths for fixed links. (a) The distance between end points of a... accordance with the equation set forth below. Frequency band(MHz) Minimum path length(km) Below 1,990 n/a...

  13. 47 CFR 74.644 - Minimum path lengths for fixed links.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Minimum path lengths for fixed links. 74.644... Auxiliary Stations § 74.644 Minimum path lengths for fixed links. (a) The distance between end points of a... accordance with the equation set forth below. Frequency band(MHz) Minimum path length(km) Below 1,990 n/a...

  14. 47 CFR 74.644 - Minimum path lengths for fixed links.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Minimum path lengths for fixed links. 74.644... Auxiliary Stations § 74.644 Minimum path lengths for fixed links. (a) The distance between end points of a... accordance with the equation set forth below. Frequency band(MHz) Minimum path length(km) Below 1,990 n/a...

  15. Comparison of slurry versus fixed-bed reactor costs for indirect liquefaction applications

    SciTech Connect

    Prakash, A.; Bendale, P.G.

    1991-12-01

    This work is a comparative evaluation of slurry reactors and fixed-bed reactors, with special emphasis on cost. Relative differences between slurry reactors and fixed-bed reactors have been pointed out in previous reviews; the differences pertinent to indirect liquefaction are summarized here. Design of both types is outlined.

  16. Genetic and structural analysis of the Rhizobium meliloti fixA, fixB, fixC, and fixX genes.

    PubMed Central

    Earl, C D; Ronson, C W; Ausubel, F M

    1987-01-01

    The fixA, fixB, fixC, and fixX genes of Rhizobium meliloti 1021 constitute an operon and are required for nitrogen fixation in alfalfa nodules. DNA homologous to the R. meliloti fixABC genes is present in all other Rhizobium and Bradyrhizobium species examined, but fixABC-homologous sequences were found in only one free-living diazotroph, Azotobacter vinelandii. To determine whether the fixABCX genes share sequence homology with any of the 17 Klebsiella pneumoniae nif genes, we determined the entire nucleotide sequence of the fixA, fixB, fixC, and fixX genes and defined four open reading frames that code for polypeptides of molecular weights 31,146, 37,786, 47,288, and 10,937, respectively. Neither DNA nor amino acid sequence homology to the R. meliloti fixA, -B, -C, and -X genes was found in the K. pneumoniae nif operon. The fixX gene contains a cluster of cysteine residues characteristic of ferredoxins and is highly homologous to an Azotobacter ferredoxin which has been shown to donate electrons to nitrogenase. The fixABC operon contains a promoter region that is highly homologous to other nifA-activated promoters. We also found a duplication of the 5' end of the fixABCX operon; a 250-bp region located 520 bp upstream of the fixABCX promoter bears more than 65% homology to the 5' end of the transcribed region, including the first 32 codons of fixA. Images PMID:3029021

  17. Unraveling the reaction mechanisms governing methanol-to-olefins catalysis by theory and experiment.

    PubMed

    Hemelsoet, Karen; Van der Mynsbrugge, Jeroen; De Wispelaere, Kristof; Waroquier, Michel; Van Speybroeck, Veronique

    2013-06-01

    The conversion of methanol to olefins (MTO) over a heterogeneous nanoporous catalyst material is a highly complex process involving a cascade of elementary reactions. The elucidation of the reaction mechanisms leading to either the desired production of ethene and/or propene or undesired deactivation has challenged researchers for many decades. Clearly, catalyst choice, in particular topology and acidity, as well as the specific process conditions determine the overall MTO activity and selectivity; however, the subtle balances between these factors remain not fully understood. In this review, an overview of proposed reaction mechanisms for the MTO process is given, focusing on the archetypal MTO catalysts, H-ZSM-5 and H-SAPO-34. The presence of organic species, that is, the so-called hydrocarbon pool, in the inorganic framework forms the starting point for the majority of the mechanistic routes. The combination of theory and experiment enables a detailed description of reaction mechanisms and corresponding reaction intermediates. The identification of such intermediates occurs by different spectroscopic techniques, for which theory and experiment also complement each other. Depending on the catalyst topology, reaction mechanisms proposed thus far involve aromatic or aliphatic intermediates. Ab initio simulations taking into account the zeolitic environment can nowadays be used to obtain reliable reaction barriers and chemical kinetics of individual reactions. As a result, computational chemistry and by extension computational spectroscopy have matured to the level at which reliable theoretical data can be obtained, supplying information that is very hard to acquire experimentally. Special emphasis is given to theoretical developments that open new perspectives and possibilities that aid to unravel a process as complex as methanol conversion over an acidic porous material. PMID:23595911

  18. 29 CFR 1917.118 - Fixed ladders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Fixed ladders. 1917.118 Section 1917.118 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.118 Fixed ladders. (a) Scope and applicability. This section applies to all fixed ladders...

  19. 29 CFR 1917.118 - Fixed ladders.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Fixed ladders. 1917.118 Section 1917.118 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.118 Fixed ladders. (a) Scope and applicability. This section applies to all fixed ladders...

  20. 29 CFR 1917.120 - Fixed stairways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Fixed stairways. 1917.120 Section 1917.120 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.120 Fixed stairways. (a) Definition. “Fixed...

  1. 29 CFR 1917.120 - Fixed stairways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Fixed stairways. 1917.120 Section 1917.120 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.120 Fixed stairways. (a) Definition. “Fixed...

  2. Unraveling the chemical space of terrestrial and meteoritic organic matter

    NASA Astrophysics Data System (ADS)

    Schmitt-Kopplin, Philippe; Harir, Mourad; Hertkorn, Norbert; Kanawati, Basem; Ruf, Alexander; Quirico, Eric; Bonal, Lydie; Beck, Pierre; Gabelica, Zelimir

    2015-04-01

    )High resolution analytical approaches will be presented in their application to unravel the chemical nature and organic signatures in bio-geosystems and especially in selected chondritic (organic and ordinary) and achondritic meteorites. We will focus on thermal effects in CM types of materials and describe the effect of shock events on the changes in chemodiversity and the formation of unique novel organic compounds using high magnetic field ultrahigh resolution mass spectrometry (12 Tesla ion cyclotron resonance Fourier transform mass spectrometry - ICR-FT/MS) and nuclear magnetic resonance spectroscopy (Cryo 800MHz NMR).

  3. FixO3 Network Project: Integration, harmonization and innovation

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard; Cristini, Luisa

    2016-04-01

    The Fixed point Open Ocean Observatory network (FixO3, http://www.fixo3.eu/) seeks to integrate 23 European open ocean fixed point observatories in the Atlantic Ocean and Mediterranean Sea and to improve access to these infrastructures for the broader community. These provide multidisciplinary observations from the air-sea interface to the deep seafloor. Started in September 2013 with a budget of 7 Million Euros over 4 years, the project has 29 partners drawn from academia, research institutions and SME's coordinated by the National Oceanography Centre, UK. The project is structured in 12 Work Packages aimed to: • integrate and harmonise the current infrastructures and processes • offer free access to observatory infrastructures to those who do not have such access, and free and open data services and products • innovate and enhance the current capability for multidisciplinary in situ ocean observation Here we present the programme's key achievements mid-way, the current activities and expected results. Emphasis will be on FixO3-generated tools and products and their applications for the wider oceanographic community for the benefit of science, industry and policy.

  4. Global Positioning System Antenna Fixed Height Tripod Adapter

    NASA Technical Reports Server (NTRS)

    Dinardo, Steven J.; Smith, Mark A.

    1997-01-01

    An improved Global Positioning em antenna adaptor allows fixed antenna height measurements by removably attaching an adaptor plate to a conventional surveyor's tripod. Antenna height is controlled by an antenna boom which is a fixed length rod. The antenna is attached to one end of the boom. The opposite end of the boom tapers to a point sized to fit into a depression at the center of survey markers. The boom passes through the hollow center of a universal ball joint which is mounted at the center of the adaptor plate so that the point of the rod can be fixed in the marker's central depression. The mountains of the ball joint allow the joint to be moved horizontally in any direction relative to the tripod. When the ball joint is moved horizontally, the angle between the boom and the vertical changes because the boom's position is fixed at its lower end. A spirit level attached to the rod allows an operator to determine when the boom is plumb. The position of the ball joint is adjusted horizontally until the boom is plumb. At that time the antenna is positioned exactly over the center of the monument and the elevation of the antenna is precisely set by the length of the boom.

  5. Simple Fixed Functional Space Maintainer

    PubMed Central

    Sarawgi, Aditi; Marwah, Nikhil; Gumber, Parvind; Dutta, Samir

    2014-01-01

    ABSTRACT% Premature loss of a primary tooth is one of the most common etiology for malocclusion. Space maintainers are employed to prevent this complication. In anterior region, esthetics is an important concern along with function and space management. Fiber-reinforced composite (FRC) retained space maintainer solves all these purposes ef ficiently and ef fectively. In addition, the technique is simple and the appliance is very comfortable inside the oral cavity. Here is a case of premature loss of anterior primary tooth which was replaced by FRC retained esthetic functional space maintainer. The appliance was found to be functioning satisfactorily inside the oral cavity till the last visit (1 Year). How to cite this article: Goenka P, Sarawgi A, Marwah N, Gumber P, Dutta S. Simple Fixed Functional Space Maintainer. Int J Clin Pediatr Dent 2014;7(3):225-228. PMID:25709309

  6. Unraveling topography around subduction zones from laboratory models

    NASA Astrophysics Data System (ADS)

    Husson, Laurent; Guillaume, Benjamin; Funiciello, Francesca; Faccenna, Claudio; Royden, Leigh H.

    2012-03-01

    The relief around subduction zones results from the interplay of dynamic processes that may locally exceed the (iso)static contributions. The viscous dissipation of the energy in and around subduction zones is capable of generating kilometer scale vertical ground movements. In order to evaluate dynamic topography in a self-consistent subduction system, we carried out a set of laboratory experiments, wherein the lithosphere and mantle are simulated by means of Newtonian viscous materials, namely silicone putty and glucose syrup. Models are kept in their most simple form and are made of negative buoyancy plates, of variable width and thickness, freely plunging into the syrup. The surface of the model and the top of the slab are scanned in three dimensions. A forebulge systematically emerges from the bending of the viscous plate, adjacent to the trench. With a large wavelength, dynamic pressure offsets the foreside and backside of the slab by ~ 500 m on average. The suction, that accompanies the vertical descent of the slab depresses the surface on both sides. At a distance equal to the half-width of the slab, the topographic depression amounts to ~ 500 m on average and becomes negligible at a distance that equals the width of the slab. In order to explore the impact of slab rollback on the topography, the trailing edge of the plates is alternatively fixed to (fixed mode) and freed from (free mode) the end wall of the tank. Both the pressure and suction components of the topography are ~ 30% lower in the free mode, indicating that slab rollback fosters the dynamic subsidence of upper plates. Our models are compatible with first order observations of the topography around the East Scotia, Tonga, Kermadec and Banda subduction zones, which exhibit anomalous depths of nearly 1 km as compared to adjacent sea floor of comparable age.

  7. Unraveling the Effects of Critical Thinking Instructions, Practice, and Self-Explanation on Students' Reasoning Performance

    ERIC Educational Resources Information Center

    Heijltjes, Anita; van Gog, Tamara; Leppink, Jimmie; Paas, Fred

    2015-01-01

    Acquisition of critical thinking skills is considered an important goal in higher education, but it is still unclear which specific instructional techniques are effective for fostering it. The main aim of this study was to unravel the impact of critical thinking instructions, practice, and self-explanation prompts during practice, on students'…

  8. Unraveling the Complexity of Student Teachers' Learning in and from the Workplace

    ERIC Educational Resources Information Center

    Leeferink, Han; Koopman, Maaike; Beijaard, Douwe; Ketelaar, Evelien

    2015-01-01

    This study reports on how student teachers' workplace experiences were transformed into learning experiences. In total, 26 stories from 10 student teachers were collected by means of digital logs and in-depth interviews and unraveled using a new technique of reconstructing stories into webs. In these webs, the factors that played a role in student…

  9. Unravelling the Sources of Adolescent Substance Use: A Test of Rival Theories

    ERIC Educational Resources Information Center

    Jonson, Cheryl Lero; McArthur, Rachel; Cullen, Francis T.; Wilcox, Pamela

    2012-01-01

    Among any cohort of American youths, some will use drugs and alcohol whereas others will not. Further, some youngsters will not only use these illegal substances but also abuse them, at times wreaking havoc with their lives and ruining their futures. The purpose of this study is to attempt to unravel this heterogeneity of substance abuse; that is,…

  10. Realization of the Temperature Scale in the Range from 234.3 K (Hg Triple Point) to 1084.62°C (Cu Freezing Point) in Croatia

    NASA Astrophysics Data System (ADS)

    Zvizdic, Davor; Veliki, Tomislav; Grgec Bermanec, Lovorka

    2008-06-01

    This article describes the realization of the International Temperature Scale in the range from 234.3 K (mercury triple point) to 1084.62°C (copper freezing point) at the Laboratory for Process Measurement (LPM), Faculty of Mechanical Engineering and Naval Architecture (FSB), University of Zagreb. The system for the realization of the ITS-90 consists of the sealed fixed-point cells (mercury triple point, water triple point and gallium melting point) and the apparatus designed for the optimal realization of open fixed-point cells which include the gallium melting point, tin freezing point, zinc freezing point, aluminum freezing point, and copper freezing point. The maintenance of the open fixed-point cells is described, including the system for filling the cells with pure argon and for maintaining the pressure during the realization.

  11. Fixed drug eruptions with modafinil

    PubMed Central

    Ghoshal, Loknath; Sinha, Mausumi

    2015-01-01

    Modafinil is a psychostimulant drug, which has been approved by the US Food and Drug Administration for the treatment of narcolepsy associated excessive daytime sleepiness, sleep disorder related to shift work, and obstructive sleep apnea syndrome. However, presently it is being used as a lifestyle medicine; in India, it has been misused as an “over the counter” drug. Modafinil is known to have several cutaneous side effects. Fixed drug eruption (FDE) is a distinctive drug induced reaction pattern characterized by recurrence of eruption at the same site of the skin or mucous membrane with repeated systemic administration. Only two case reports exist in the literature describing modafinil induced FDE until date. Here, we report two similar cases. The increasing use of this class of drug amongst the medical personnel might be posing a threat to the proper use and encouraging subsequent abuse. There might be a considerable population using these drugs unaware of the possible adverse effects. Authorities should be more alert regarding the sale and distribution of such medicines. PMID:25878389

  12. Seven lean years. [No quick fix available

    SciTech Connect

    Byron, C.

    1980-12-22

    The end of the cheap oil era is having a more profound impact than any other single issue or event since World War II, making the everything crisis a more-appropriate label than energy crisis. Warnings from OPEC that oil may rise to $60 per barrel will not have worldwide inventories as a moderating force because the Iran-Iraq war has reduced OPEC production to the point where oil companies are unwilling to draw down their stockpiles. The cartel's prices have merely exploited a worldwide increase in demand for oil that would have pushed prices up anyway. The social and economic havoc is straining the economies of developed countries and could bankrupt and destabilize much of the Third World. The search for non-OPEC oil sources and alternatives to oil prompted a global race to discover new reserves, exploit renewable fuel sources, and initiate conservation. With no quick fix available, a painful period is foreseen while people learn to husband natural resources. (DCK)

  13. Controlling superconductivity by tunable quantum critical points.

    PubMed

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-01-01

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5. PMID:25737108

  14. Expanding the regulatory network that controls nitrogen fixation in Sinorhizobium meliloti: elucidating the role of the two-component system hFixL-FxkR.

    PubMed

    Reyes-González, Alma; Talbi, Chouhra; Rodríguez, Susana; Rivera, Patricia; Zamorano-Sánchez, David; Girard, Lourdes

    2016-06-01

    In Sinorhizobium meliloti, nitrogen fixation is regulated in response to oxygen concentration through the FixL-FixJ two-component system (TCS). Besides this conserved TCS, the field isolate SM11 also encodes the hFixL-FxkR TCS, which is responsible for the microoxic response in Rhizobium etli. Through genetic and physiological assays, we evaluated the role of the hFixL-FxkR TCS in S. meliloti SM11. Our results revealed that this regulatory system activates the expression of a fixKf orthologue (fixKa), in response to low oxygen concentration. Null mutations in either hFixL or FxkR promote upregulation of fixK1, a direct target of FixJ. Furthermore, the absence of this TCS translates into higher nitrogen fixation values as well as higher expression of fixN1 in nodules. Individual mutations in each of the fixK-like regulators encoded in the S. meliloti SM11 genome do not completely restrict fixN1 or fixN2 expression, pointing towards redundancy among these regulators. Both copies of fixN are necessary to achieve optimal levels of nitrogen fixation. This work provides evidence that the hFixL-FxkR TCS is activated in response to low oxygen concentration in S. meliloti SM11 and that it negatively regulates the expression of fixK1, fixN1 and nitrogen fixation. PMID:27010660

  15. NASA's Great Observatories May Unravel 400-Year Old Supernova Mystery

    NASA Astrophysics Data System (ADS)

    2004-10-01

    Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, best known as the discoverer of the laws of planetary motion, were startled by the sudden appearance of a "new star" in the western sky, rivaling the brilliance of the nearby planets. Kepler's Supernova Remnant Multiple Images of Kepler's Supernova Remnant Modern astronomers, using NASA's three orbiting Great Observatories, are unraveling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy. When a new star appeared Oct. 9, 1604, observers could use only their eyes to study it. The telescope would not be invented for another four years. A team of modern astronomers has the combined abilities of NASA's Great Observatories, the Spitzer Space Telescope (SST), Hubble Space Telescope (HST), and Chandra X-ray Observatory, to analyze the remains in infrared radiation, visible light, and X-rays. Ravi Sankrit and William Blair of the Johns Hopkins University in Baltimore lead the team. The combined image unveils a bubble-shaped shroud of gas and dust, 14 light-years wide and expanding at 4 million mph. Observations from each telescope highlight distinct features of the supernova, a fast-moving shell of iron-rich material, surrounded by an expanding shock wave sweeping up interstellar gas and dust. Interview with Dr. Ravi Sankrit Interview with Dr. Ravi Sankrit "Multi-wavelength studies are absolutely essential for putting together a complete picture of how supernova remnants evolve," Sankrit said. Sankrit is an associate research scientist, Center for Astrophysical Sciences at Hopkins and lead for HST astronomer observations. "For instance, the infrared data are dominated by heated interstellar dust, while optical and X-ray observations sample different temperatures of gas," Blair added. Blair is a research professor, Physics and Astronomy Department at Hopkins and lead astronomer for SST observations. "A range of

  16. The VLT Unravels the Nature of the Fastest Binary Star

    NASA Astrophysics Data System (ADS)

    2002-03-01

    Two Hot White Dwarfs Perform a Tight Dance Summary Observations with ESO's Very Large Telescope (VLT) in Chile and the Italian Telescopio Nazionale Galileo (TNG) on the Canary Islands during the past two years have enabled an international group of astronomers [1] to unravel the true nature of an exceptional binary stellar system. This system, designated RX J0806.3+1527 , was first discovered as an X-ray source of variable brightness - once every five minutes, it "switches off" for a short moment. The new observations have shown beyond doubt that this period reflects the orbital motion of two "white dwarf" stars that revolve around each other at a distance of only 80,000 km . Each of the stars is about as large as the Earth and this is the shortest orbital period known for any binary stellar system. The VLT spectrum displays lines of ionized helium, indicating that the presence of an exceedingly hot area on one of the stars - a "hot spot" with a temperature of approx. 250,000 degrees. The system is currently in a rarely seen, transitory evolutionary state . PR Photo 10a/02 : U- and R-band images of RX J0806.3+1527. PR Photo 10b/02 : Spectrum of RX J0806.3+1527 An amazing stellar binary system ESO PR Photo 10a/02 ESO PR Photo 10a/02 [Preview - JPEG: 800 x 400 pix - 440k] [Normal - JPEG: 1600 x 800 pix - 1.1M] Caption : PR Photo 10a/02 shows U and R filter images of the sky field around RX J0806.3+1527 (at centre of circle), obtained with the FORS2 multi-mode instrument on VLT KUEYEN. The object is brightest at the shorter wavelength (U-band) - reflecting its very high temperature. Technical information about the photo is available below. One year is the time it takes the Earth to move once around the Sun, our central star. This may seem quite fast when measured on the scale of the Universe, but this is a snail's motion compared to the the speed of two recently discovered stars. They revolve around each other 100,000 times faster; one full revolution takes only 321

  17. NASA's Great Observatories May Unravel 400-Year Old Supernova Mystery

    NASA Astrophysics Data System (ADS)

    2004-10-01

    Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, best known as the discoverer of the laws of planetary motion, were startled by the sudden appearance of a "new star" in the western sky, rivaling the brilliance of the nearby planets. Kepler's Supernova Remnant Multiple Images of Kepler's Supernova Remnant Modern astronomers, using NASA's three orbiting Great Observatories, are unraveling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy. When a new star appeared Oct. 9, 1604, observers could use only their eyes to study it. The telescope would not be invented for another four years. A team of modern astronomers has the combined abilities of NASA's Great Observatories, the Spitzer Space Telescope (SST), Hubble Space Telescope (HST), and Chandra X-ray Observatory, to analyze the remains in infrared radiation, visible light, and X-rays. Ravi Sankrit and William Blair of the Johns Hopkins University in Baltimore lead the team. The combined image unveils a bubble-shaped shroud of gas and dust, 14 light-years wide and expanding at 4 million mph. Observations from each telescope highlight distinct features of the supernova, a fast-moving shell of iron-rich material, surrounded by an expanding shock wave sweeping up interstellar gas and dust. Interview with Dr. Ravi Sankrit Interview with Dr. Ravi Sankrit "Multi-wavelength studies are absolutely essential for putting together a complete picture of how supernova remnants evolve," Sankrit said. Sankrit is an associate research scientist, Center for Astrophysical Sciences at Hopkins and lead for HST astronomer observations. "For instance, the infrared data are dominated by heated interstellar dust, while optical and X-ray observations sample different temperatures of gas," Blair added. Blair is a research professor, Physics and Astronomy Department at Hopkins and lead astronomer for SST observations. "A range of

  18. Unravelling the impact of inheritance within the Wilson Cycle: a combined mapping and numerical modelling approach

    NASA Astrophysics Data System (ADS)

    Chenin, Pauline; Manatschal, Gianreto; Lavier, Luc

    2015-04-01

    Our study aims to unravel how structural, lithological and thermal heterogeneities may influence both orogenic and rift systems within the Wilson Cycle. To do this, we map first-order rift structural domains, timing of the main rift events as well as major heterogeneities and structures inherited from previous orogenies. Besides, we design numerical modelling experiments to investigate the relationships highlighted from the comparison of these maps. We apply this approach to the North Atlantic region, which underwent two major orogenic phases during the Palaeozoic: (1) the Caledonian orogeny - now extending from United-Kingdom to northern Norway and Eastern Greenland - resulted from the Late Ordovician closure of the large Iapetus ocean (> 2 000 km) and smaller Tornquist Seaway. It was followed by purely mechanical extensional orogenic collapse; (2) the Variscides of Southwestern Europe were essentially built from the Devono-Carboniferous suturing of several small oceanic basins (< 200 km) in addition to the large Rheic Ocean. The subsequent orogenic collapse was accompanied by significant magmatic activity, which resulted in mafic underplating and associated mantle depletion over the whole orogenic area. Our study is twofolds: On the one hand, we investigate how the size and maturity of the intervening oceanic basins affect subduction and orogeny, considering two end-members: (a) immature oceanic basins defined as hyperextended rift systems that never achieved steady state seafloor spreading; and (b) mature oceans characterized by a self-sustained magmatic system forming homogeneous oceanic crust. On the other hand, we study how post-orogenic collapse-related underplating and associated mantle depletion may impact subsequent rifting depending on the thermal state (e.g. the duration of relaxation time between the magmatic episode and the onset of rifting). Our results highlight a very different behaviour of the North Atlantic rift with respect to the Caledonian and

  19. Statistical analysis of fixed income market

    NASA Astrophysics Data System (ADS)

    Bernaschi, Massimo; Grilli, Luca; Vergni, Davide

    2002-05-01

    We present cross and time series analysis of price fluctuations in the US Treasury fixed income market. Bonds have been classified according to a suitable metric based on the correlation among them. The classification shows how the correlation among fixed income securities depends strongly on their maturity. We study also the structure of price fluctuations for single time series.

  20. Fixed-Response Questions with a Difference.

    ERIC Educational Resources Information Center

    Johnstone, Alex H.; Ambusaidi, Abdullah

    2002-01-01

    Offers three types of fixed-response questions that are designed to overcome drawbacks appearing in the conventional forms of fixed-response questions such as not allowing the examiner to investigate reasoning, background, or prevent guessing. (Contains 14 references.) (Author/YDS)

  1. 29 CFR 1910.27 - Fixed ladders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...). For fixed ladders consisting of wood side rails and wood rungs or cleats, used at a pitch in the range..., cleats, and steps shall be free of splinters, sharp edges, burrs, or projections which may be a hazard... of fixed ladders shall be considered to come in the range of 75 degrees and 90 degrees with...

  2. Negotiating a Fixed-Unit Price Contract.

    ERIC Educational Resources Information Center

    Pasquale, Mathew; Morrison, Wade

    1986-01-01

    Discusses the concept of "fixed-unit price contracting," an arrangement that is becoming popular with private industry councils (PICs). Guidelines include (1) find out as much as you can about the PIC's requirements; (2) figure out whether you can meet the PIC's requirements; and (3) keep in mind that most elements of a fixed-unit price contract…

  3. Gaining Insight into an Organization's Fixed Assets.

    ERIC Educational Resources Information Center

    Hardy, Elisabet

    2003-01-01

    Discusses issues related to school district implementation of June 2001 Government Accounting Standards Board (GASB) Statement 34 designed to change how schools report fixed assets. Includes planning for GASB implementation, conducting fixed-asset inventories, and making time for GASB reporting. (PKP)

  4. 78 FR 20705 - Fixed Income Roundtable

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-05

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Fixed Income Roundtable AGENCY: Securities and Exchange Commission. ACTION: Notice of roundtable..., efficiency, and other aspects of fixed income markets. The roundtable will focus on the municipal...

  5. Optimal mixing and optimal stirring for fixed energy, fixed power, or fixed palenstrophy flows

    NASA Astrophysics Data System (ADS)

    Lunasin, Evelyn; Lin, Zhi; Novikov, Alexei; Mazzucato, Anna; Doering, Charles R.

    2012-11-01

    We consider passive scalar mixing by a prescribed divergence-free velocity vector field in a periodic box and address the following question: Starting from a given initial inhomogeneous distribution of passive tracers, and given a certain energy budget, power budget, or finite palenstrophy budget, what incompressible flow field best mixes the scalar quantity? We focus on the optimal stirring strategy recently proposed by Lin et al. ["Optimal stirring strategies for passive scalar mixing," J. Fluid Mech. 675, 465 (2011)], 10.1017/S0022112011000292 that determines the flow field that instantaneously maximizes the depletion of the H-1 mix-norm. In this work, we bridge some of the gap between the best available a priori analysis and simulation results. After recalling some previous analysis, we present an explicit example demonstrating finite-time perfect mixing with a finite energy constraint on the stirring flow. On the other hand, using a recent result by Wirosoetisno et al. ["Long time stability of a classical efficient scheme for two dimensional Navier-Stokes equations," SIAM J. Numer. Anal. 50(1), 126-150 (2012)], 10.1137/110834901 we establish that the H-1 mix-norm decays at most exponentially in time if the two-dimensional incompressible flow is constrained to have constant palenstrophy. Finite-time perfect mixing is thus ruled out when too much cost is incurred by small scale structures in the stirring. Direct numerical simulations in two dimensions suggest the impossibility of finite-time perfect mixing for flows with fixed power constraint and we conjecture an exponential lower bound on the H-1 mix-norm in this case. We also discuss some related problems from other areas of analysis that are similarly suggestive of an exponential lower bound for the H-1 mix-norm.

  6. Fixed-sample optimization using a probability density function

    SciTech Connect

    Barnett, R.N.; Sun, Zhiwei; Lester, W.A. Jr. |

    1997-12-31

    We consider the problem of optimizing parameters in a trial function that is to be used in fixed-node diffusion Monte Carlo calculations. We employ a trial function with a Boys-Handy correlation function and a one-particle basis set of high quality. By employing sample points picked from a positive definite distribution, parameters that determine the nodes of the trial function can be varied without introducing singularities into the optimization. For CH as a test system, we find that a trial function of high quality is obtained and that this trial function yields an improved fixed-node energy. This result sheds light on the important question of how to improve the nodal structure and, thereby, the accuracy of diffusion Monte Carlo.

  7. Unraveling bed slope from relative roughness in initial sediment motion

    NASA Astrophysics Data System (ADS)

    Prancevic, Jeff P.; Lamb, Michael P.

    2015-03-01

    Understanding incipient sediment transport is crucial for predicting landscape evolution, mitigating flood hazards, and restoring riverine habitats. Observations show that the critical Shields stress increases with increasing channel bed slope, and proposed explanations for this counterintuitive finding include enhanced form drag from bed forms, particle interlocking across the channel width, and large bed sediment relative to flow depth (relative roughness). Here we use scaled flume experiments with variable channel widths, bed slopes, and particle densities to separate these effects which otherwise covary in natural streams. The critical Shields stress increased with bed slope for both natural gravel (ρs = 2.65 g/cm3) and acrylic particles (ρs = 1.15 g/cm3), and adjusting channel width had no significant effect. However, the lighter acrylic particles required a threefold higher critical Shields stress for mobilization relative to the natural gravel at a fixed slope, which is unexpected because particle density is accounted for directly in the definition of Shields stress. A comparison with model predictions indicates that changes in local velocity and turbulence associated with increasing relative roughness for lighter materials are responsible for increasing the critical Shields stress in our experiments. These changes lead to concurrent changes in the hydraulic resistance and a nearly constant critical stream power value at initial motion. Increased relative roughness can explain much of the observed heightened critical Shields stresses and reduced sediment transport rates in steep channels and also may bias paleohydraulic reconstructions in environments with exotic submerged densities such as iron ore, pumice, or ice clasts on Titan.

  8. Unraveling the Equine Lymphocyte Proteome: Differential Septin 7 Expression Associates with Immune Cells in Equine Recurrent Uveitis

    PubMed Central

    Degroote, Roxane L.; Hauck, Stefanie M.; Amann, Barbara; Hirmer, Sieglinde; Ueffing, Marius; Deeg, Cornelia A.

    2014-01-01

    Equine recurrent uveitis is a spontaneous, lymphocyte-driven autoimmune disease. It affects horses worldwide and presents with painful remitting-relapsing inflammatory attacks of inner eye structures eventually leading to blindness. Since lymphocytes are the key players in equine recurrent uveitis, we were interested in potential changes of their protein repertoire which may be involved in disease pathogenesis. To create a reference for differential proteome analysis, we first unraveled the equine lymphocyte proteome by two-dimensional sodium dodecyl sulfate - polyacrylamide gel electrophoresis and subsequently identified 352 protein spots. Next, we compared lymphocytes from ERU cases and healthy horses with a two-dimensional fluorescence difference in gel electrophoresis approach. With this technique, we identified seven differentially expressed proteins between conditions. One of the significantly lower expressed candidates, septin 7, plays a role in regulation of cell shape, motility and migration. Further analyses revealed T cells as the main cell type with decreased septin 7 abundance in equine recurrent uveitis. These findings point to a possible pathogenetic role of septin 7 in this sight-threatening disease. PMID:24614191

  9. Quantum critical points of j =3/2 Dirac electrons in antiperovskite topological crystalline insulators

    NASA Astrophysics Data System (ADS)

    Isobe, Hiroki; Fu, Liang

    2016-06-01

    We study the effect of the long-range Coulomb interaction in j =3 /2 Dirac electrons in cubic crystals with the Oh symmetry, which serves as an effective model for antiperovskite topological crystalline insulators. The renormalization group analysis reveals three fixed points that are Lorentz invariant, rotationally invariant, and Oh invariant. Among them, the Lorentz- and Oh-invariant fixed points are stable in the low-energy limit, while the rotationally invariant fixed point is unstable. The existence of a stable Oh-invariant fixed point of Dirac fermions with finite velocity anisotropy presents an interesting counterexample to emergent Lorentz invariance in solids.

  10. Unraveled mechanism in silk engineering: Fast reeling induced silk toughening

    NASA Astrophysics Data System (ADS)

    Wu, Xiang; Liu, Xiang-Yang; Du, Ning; Xu, Gangqin; Li, Baowen

    2009-08-01

    We theoretically and experimentally study the mechanical response of silkworm and spider silks against stretching and the relationship with the underlying structural factors. It is found that the typical stress-strain profiles are predicted in good agreement with experimental measurements by implementing the "β-sheet splitting" mechanism we discovered and verified, primarily varying the secondary structure of protein macromolecules. The functions of experimentally observed structural factors responding to the external stress have been clearly addressed, and optimization of the microscopic structures to enhance the mechanical strength will be pointed out, beneficial to their biomedical and textile applications.

  11. ON LYAPUNOV FAMILIES AROUND COLLINEAR LIBRATION POINTS

    SciTech Connect

    Hou, X. Y.; Liu, L.

    2009-06-15

    Evolution details of the planar and vertical Lyapunov families around the three collinear libration points in the restricted three-body problem were studied. Researches before were generally restricted to be within the colliding orbits with the primaries and for fixed mass parameters {mu}. In this paper, members after colliding orbits were computed. With increasing {mu}, how these families evolve was studied.

  12. Photogrammetric Measurements in Fixed Wing Uav Imagery

    NASA Astrophysics Data System (ADS)

    Gülch, E.

    2012-07-01

    Several flights have been undertaken with PAMS (Photogrammetric Aerial Mapping System) by Germap, Germany, which is briefly introduced. This system is based on the SmartPlane fixed-wing UAV and a CANON IXUS camera system. The plane is equipped with GPS and has an infrared sensor system to estimate attitude values. A software has been developed to link the PAMS output to a standard photogrammetric processing chain built on Trimble INPHO. The linking of the image files and image IDs and the handling of different cases with partly corrupted output have to be solved to generate an INPHO project file. Based on this project file the software packages MATCH-AT, MATCH-T DSM, OrthoMaster and OrthoVista for digital aerial triangulation, DTM/DSM generation and finally digital orthomosaik generation are applied. The focus has been on investigations on how to adapt the "usual" parameters for the digital aerial triangulation and other software to the UAV flight conditions, which are showing high overlaps, large kappa angles and a certain image blur in case of turbulences. It was found, that the selected parameter setup shows a quite stable behaviour and can be applied to other flights. A comparison is made to results from other open source multi-ray matching software to handle the issue of the described flight conditions. Flights over the same area at different times have been compared to each other. The major objective was here to see, on how far differences occur relative to each other, without having access to ground control data, which would have a potential for applications with low requirements on the absolute accuracy. The results show, that there are influences of weather and illumination visible. The "unusual" flight pattern, which shows big time differences for neighbouring strips has an influence on the AT and DTM/DSM generation. The results obtained so far do indicate problems in the stability of the camera calibration. This clearly requests a usage of GCPs for all

  13. [FIXED COMBINATION ATORVASTATIN-EZETIMIBE (ATOZET®)].

    PubMed

    Scheen, A J

    2016-01-01

    Cardiovascular prevention in subjects at high or very high risk requires a drastic reduction in LDL cholesterol according to the concept "the lower, the better". The combination of an inhibitor of cholesterol synthesis and a selective inhibitor of intestinal absorption results in a complementary and synergistic LDL-lowering activity. Besides a first fixed combination ezetimibe-simvastatin (Inegy®), a new fixed combination is presented, Atozet® that combines atorvastatin and ezetimibe. Because atorvastatin is more potent than simvastatin, this novel fixed combination should facilitate reaching therapeutic goals in terms of LDL cholesterol amongst patients with severe hypercholesterolaemia and/or at high or very high cardiovascular risk. PMID:26983314

  14. The 1994 Fermilab Fixed Target Program

    SciTech Connect

    Conrad, J. |

    1994-11-01

    This paper highlights the results of the Fermilab Fixed Target Program that were announced between October, 1993 and October, 1994. These results are drawn from 18 experiments that took data in the 1985, 1987 and 1990/91 fixed target running periods. For this discussion, the Fermilab Fixed Target Program is divided into 5 major topics: hadron structure, precision electroweak measurements, heavy quark production, polarization and magnetic moments, and searches for new phenomena. However, it should be noted that most experiments span several subtopics. Also, measurements within each subtopic often affect the results in other subtopics. For example, parton distributions from hadron structure measurements are used in the studies of heavy quark production.

  15. Updraft Fixed Bed Gasification Aspen Plus Model

    Energy Science and Technology Software Center (ESTSC)

    2007-09-27

    The updraft fixed bed gasification model provides predictive modeling capabilities for updraft fixed bed gasifiers, when devolatilization data is available. The fixed bed model is constructed using Aspen Plus, process modeling software, coupled with a FORTRAN user kinetic subroutine. Current updraft gasification models created in Aspen Plus have limited predictive capabilities and must be "tuned" to reflect a generalized gas composition as specified in literature or by the gasifier manufacturer. This limits the applicability ofmore » the process model.« less

  16. Quality and matching performance analysis of three-dimensional unraveled fingerprints

    NASA Astrophysics Data System (ADS)

    Wang, Yongchang; Hao, Qi; Fatehpuria, Abhishika; Hassebrook, Laurence G.; Lau, Daniel L.

    2010-07-01

    The use of fingerprints as a biometric is both the oldest mode of computer-aided personal identification and the most-relied-on technology in use today. However, current acquisition methods have some challenging and peculiar difficulties. For higher performance fingerprint data acquisition and verification, a novel noncontact 3-D fingerprint scanner is investigated, where both the detailed 3-D and albedo information of the finger is obtained. The obtained high-resolution 3-D prints are further converted into 3-D unraveled prints, to be compatible with traditional 2-D automatic fingerprint identification systems. As a result, many limitations imposed on conventional fingerprint capture and processing can be reduced by the unobtrusiveness of this approach and the extra depth information acquired. To compare the quality and matching performances of 3-D unraveled with traditional 2-D plain fingerprints, we collect both 3-D prints and their 2-D plain counterparts. The print quality and matching performances are evaluated and analyzed by using National Institute of Standard Technology fingerprint software. Experimental results show that the 3-D unraveled print outperforms the 2-D print in both quality and matching performances.

  17. Preliminary Measurements of the Xenon Triple Point

    NASA Astrophysics Data System (ADS)

    Steur, P. P. M.; Giraudi, D.

    2014-04-01

    Ever since the construction and definition of the highly successful International Temperature Scale of 1990 (ITS-90), one severe deficiency of the scale has been recognized, without a reliable remedy. The problem is the fact that the only then available high-quality fixed point between the argon triple point and the water triple point was the mercury triple point, which unfortunately is situated rather closely to the water triple point, thus having an extremely strong influence on the interpolation function of SPRTs in the range. Already before 1990, measurements on possible fixed points better placed in this temperature range have been investigated, such as the triple points of krypton and xenon. However, results have been rather elusive, mainly regarding the rather large melting range of their transition. A turning point was the 2005 paper from the National Research Council (NRC, Canada), where it was established that the relatively high content of krypton was the culprit for the large melting range of the xenon transitions published previously. Indeed, measurements on a xenon sample with very low krypton content produced a very high-quality plateau, of the same level as other ITS-90 fixed points. However, no follow-up measurements have been reported, and thus neither have comparison measurements been reported. Shortly, after the appearance of the NRC paper, Istituto Nazionale di Ricerca Metrologica (INRIM, Italy) acquired a batch of the same high-purity xenon as used by NRC with the aim of preparing a few sealed cells with it and trying to reproduce the NRC results. However, with the start of the Neon Project (Euromet Project 770), the realization of these intentions had to be postponed until now. Last December, three cells of different design have been filled with this high-quality xenon and preliminary results of the measurements on the triple point are reported.

  18. The VLT Unravels the Nature of the Fastest Binary Star

    NASA Astrophysics Data System (ADS)

    2002-03-01

    Two Hot White Dwarfs Perform a Tight Dance Summary Observations with ESO's Very Large Telescope (VLT) in Chile and the Italian Telescopio Nazionale Galileo (TNG) on the Canary Islands during the past two years have enabled an international group of astronomers [1] to unravel the true nature of an exceptional binary stellar system. This system, designated RX J0806.3+1527 , was first discovered as an X-ray source of variable brightness - once every five minutes, it "switches off" for a short moment. The new observations have shown beyond doubt that this period reflects the orbital motion of two "white dwarf" stars that revolve around each other at a distance of only 80,000 km . Each of the stars is about as large as the Earth and this is the shortest orbital period known for any binary stellar system. The VLT spectrum displays lines of ionized helium, indicating that the presence of an exceedingly hot area on one of the stars - a "hot spot" with a temperature of approx. 250,000 degrees. The system is currently in a rarely seen, transitory evolutionary state . PR Photo 10a/02 : U- and R-band images of RX J0806.3+1527. PR Photo 10b/02 : Spectrum of RX J0806.3+1527 An amazing stellar binary system ESO PR Photo 10a/02 ESO PR Photo 10a/02 [Preview - JPEG: 800 x 400 pix - 440k] [Normal - JPEG: 1600 x 800 pix - 1.1M] Caption : PR Photo 10a/02 shows U and R filter images of the sky field around RX J0806.3+1527 (at centre of circle), obtained with the FORS2 multi-mode instrument on VLT KUEYEN. The object is brightest at the shorter wavelength (U-band) - reflecting its very high temperature. Technical information about the photo is available below. One year is the time it takes the Earth to move once around the Sun, our central star. This may seem quite fast when measured on the scale of the Universe, but this is a snail's motion compared to the the speed of two recently discovered stars. They revolve around each other 100,000 times faster; one full revolution takes only 321

  19. Preference for Reinforcers under Progressive- and Fixed-Ratio Schedules: A Comparison of Single and Concurrent Arrangements

    ERIC Educational Resources Information Center

    Glover, Ashley C.; Roane, Henry S.; Kadey, Heather J.; Grow, Laura L.

    2008-01-01

    Progressive-ratio (PR) schedules were used to identify the break point (i.e., the last schedule value completed) for 2 reinforcers under single and concurrent schedules. After the respective break points were established, the same reinforcers were presented under concurrent fixed-ratio (FR) schedules that were yoked to the break points obtained…

  20. EVALUATING MULTICOMPONENT COMPETITIVE ADSORPTION IN FIXED BEDS

    EPA Science Inventory

    An equilibrium column model (ECM) was developed to evaluate multicomponent competition in fixed-bed adsorption columns. The model ignores mass transfer resistances and uses ideal adsorbed solution theory to predict the competitive effects in multicomponent mixtures. The bed capac...

  1. Fixed-target physics at Fermilab

    SciTech Connect

    Bjorken, J.D.

    1985-03-01

    The Fermilab Energy Saver is now successfully commissioned and fixed-target experimentation at high energy (800 GeV) has begun. In addition, a number of new experiments designed to exploit the unique features of the Tevatron are yet to come on-line. In this talk, we will review recent accomplishments in the fixed-target program and describe experiments in progress and others yet to come.

  2. Experiences with Light Weight Fixed Wing Aerial Mapping UAVs

    NASA Astrophysics Data System (ADS)

    Mayr, W.

    2014-11-01

    UAVs seem to be the next "cloud" like topic, not only in geomatics. Unmanned Airborne Vehicles are not a wonder-tool, but a complementary approach to resolve some tasks more efficiently than before or at all. Since 2006 we commercially apply fixed wing, light weight UAVs for aerial mapping purposes. In this paper we like to share our experiences with UAVs of less than 5 kg and illuminate some limitations as well as potentials. Whereas multicopters seem to be in use everywhere, fixed wing UAVs more frequently seem to be applied in specific and geospatially oriented applications. Having processed several hundred UAV aerial mapping projects there forms a stable picture of this technology. Our impressions on durability, handling, and reliability of fixed wing UAVs get presented. We report on our day-to-day experiences and point to often simple hurdles to overcome. Various cameras were flown, different approaches of handling their geometries with different software packages were undertaken. Remarks to achieved geometric accuracies as well as the consequences of using dual frequency GPS instead of simple yet great single frequency GPS are discussed. All of this packed into the subsequent paper.

  3. Flight demonstration of image fix-taking with SAR

    SciTech Connect

    Gibbs, R.; Bottkol, M.; Owen, T.

    1993-06-11

    Airborne Synthetic Aperture Radar (SAR) uses coherent radar processing techniques to image ground reflectors. After processing, range and Doppler can be associated with any feature of interest in the final image. The location of any imaged feature can be estimated using a Kalman filter to combine these data with GPS and INS navigation data. This paper reports on the results of a flight demonstration of such a system, using an airborne SAR developed at Sandia. Collected data consisted of multiple SAR images containing surveyed reflectors. GPS/INS output taken aboard the aircraft, and GPS output recorded at surveyed ground stations. These data were post-processed at Sandia and at Draper Laboratory to obtain a navigation solution based on differential GPS and to demonstrate SAR fix-taking performance. This study successfully demonstrates accuracy of about 1 meter for fixing the position of a point imaged with SAR from an airborne platform. Because differential GPS was used, the navigation error was of about the same magnitude as the SAR range measurement error. Consequently, the measurements served primarily to fix the SAR image rather than to update the navigator.

  4. Event Display for the Fixed Target Experiment BM@N

    NASA Astrophysics Data System (ADS)

    Gertsenberger, Konstantin

    2016-02-01

    One of the main problems to be solved in modern high energy physics experiments on particle collisions with a fixed target is the visual representation of the events during the experiment run. The article briefly describes the structure of the BM@N facility at the Nuclotron being under construction at the Joint Institute for Nuclear Research with the aim to study properties of the baryonic matter in collisions of ions with fixed target at energies up to 4 GeV/nucleon (for Au79+). Aspects concerning the visualization of data and detector details at the modern experiments and possibilities of practical applications are discussed. We present event display system intended to visualize the detector geometries and events of particle collisions with the fixed target, its options and features as well as integration with BMNRoot software. The examples of graphical representation of simulated and reconstructed points and particle tracks with BM@N geometry are given for central collisions of Au79+ ions with gold target and deuterons with carbon target.

  5. The Fixed Irreducible Bridge Ensemble for Self-Avoiding Walks

    NASA Astrophysics Data System (ADS)

    Gilbert, Michael James

    2015-04-01

    We define a new ensemble for self-avoiding walks in the upper half-plane, the fixed irredicible bridge ensemble, by considering self-avoiding walks in the upper half-plane up to their -th bridge height, , and scaling the walk by to obtain a curve in the unit strip, and then taking . We then conjecture a relationship between this ensemble to in the unit strip from 0 to a fixed point along the upper boundary of the strip, integrated over the conjectured exit density of self-avoiding walk spanning a strip in the scaling limit. We conjecture that there exists a positive constant such that converges in distribution to that of a stable random variable as . Then the conjectured relationship between the fixed irreducible bridge scaling limit and can be described as follows: If one takes a SAW considered up to and scales by and then weights the walk by to an appropriate power, then in the limit , one should obtain a curve from the scaling limit of the self-avoiding walk spanning the unit strip. In addition to a heuristic derivation, we provide numerical evidence to support the conjecture and give estimates for the boundary scaling exponent.

  6. Unraveling the nature of interaction between substituted phenol and amiodarone.

    PubMed

    Hassan, Walid M I; Abo Dena, Ahmed S

    2014-02-01

    A comprehensive study of the interaction between nitrophenols (π-acceptors) and amiodarone (AM) was performed using electronic absorption spectra. The key point is to clarify the erroneous interpretation of the interaction between nitrophenols and one of the basic organic drugs. Matching of the experimental UV-vis spectra and the theoretical ones obtained by DFT calculations revealed that the tertiary amino group of AM reacts with the phenol compounds under investigation via proton-transfer but not charge-transfer (C.T.) mechanisms, unlike what is commonly known about this type of interaction. The interaction was carried out in solutions of different basic pH values to study the effect of hydrogen ion concentration on the reaction. The results show that the reaction is a simple acid-base reaction. As a result, this reaction cannot be used by analytical chemists for determination of one of the studied compounds due to its very low selectivity. TD-DFT as well as geometry optimization of the nitrophenols were calculated with the B3LYP functional, using aug-cc-pvDZ and LanL2DZ as basis sets for ionic and neutral compounds, respectively. The theoretical spectra of possible interactions between AM and nitrophenols result in the same spectra of ionized nitrophenols alone, indicating no possibility for the formation of charge-transfer complexes. PMID:24428617

  7. Unraveling the tapestry of life. Can we mend our earth?

    PubMed

    Sherman, D

    1991-12-01

    The industrial revolution has reached its most significant turning point. For the 1st time in its history the limiting factor in its growth has not been our ability to utilize resources, but rather a lack of the resources themselves. At the same time the largest problem to ever face our species, the loss of biodiversity, is threatening our own survival. Clearly we can not support our current numbers under the current consumptive system. All our food is provided by wild species that have been genetically manipulated to serve our ends. Of the 80,000 known edible plant species only about 200 are cultivated regularly and only 3 (corn, wheat, rice) function as staples. Many of our industrial resources come from natural sources. 40% of our pharmaceuticals come from wild sources. It is impossible to isolate ourselves from the Earth ecosystem. Soil microorganisms are but one example of our dependence upon nature. The rainforests also serve as our planets lungs, without them we will choke to death. Yet we continue to destroy them at an alarming rate. They account for only 7% of our land area, and they have already shrunk some 40%. In purely economic terms the wholesale destruction of the rainforests is bad business: in rubber and fruit, 2.5 acres of rainforest is worth $9000 annually compared to cow pasture ($2500) and logging ($1000). Of course with fruit and rubber the rainforest remains sustainable while cow pasture and logging mean the destruction of the rainforest. PMID:12343498

  8. Unravelling and controlling hidden imprint fields in ferroelectric capacitors

    PubMed Central

    Liu, Fanmao; Fina, Ignasi; Bertacco, Riccardo; Fontcuberta, Josep

    2016-01-01

    Ferroelectric materials have a spontaneous polarization that can point along energetically equivalent, opposite directions. However, when ferroelectric layers are sandwiched between different metallic electrodes, asymmetric electrostatic boundary conditions may induce the appearance of an electric field (imprint field, Eimp) that breaks the degeneracy of the polarization directions, favouring one of them. This has dramatic consequences on functionality of ferroelectric-based devices such as ferroelectric memories or photodetectors. Therefore, to cancel out the Eimp, ferroelectric components are commonly built using symmetric contact configuration. Indeed, in this symmetric contact configuration, when measurements are done under time-varying electric fields of relatively low frequency, an archetypical symmetric single-step switching process is observed, indicating Eimp ≈ 0. However, we report here on the discovery that when measurements are performed at high frequency, a well-defined double-step switching is observed, indicating the presence of Eimp. We argue that this frequency dependence originates from short-living head-to-head or tail-to-tail ferroelectric capacitors in the device. We demonstrate that we can modulate Eimp and the life-time of head-to-head or tail-to-tail polarization configurations by adjusting the polarization screening charges by suitable illumination. These findings are of relevance to understand the effects of internal electric fields on pivotal ferroelectric properties, such as memory retention and photoresponse. PMID:27122309

  9. Unravelling and controlling hidden imprint fields in ferroelectric capacitors

    NASA Astrophysics Data System (ADS)

    Liu, Fanmao; Fina, Ignasi; Bertacco, Riccardo; Fontcuberta, Josep

    2016-04-01

    Ferroelectric materials have a spontaneous polarization that can point along energetically equivalent, opposite directions. However, when ferroelectric layers are sandwiched between different metallic electrodes, asymmetric electrostatic boundary conditions may induce the appearance of an electric field (imprint field, Eimp) that breaks the degeneracy of the polarization directions, favouring one of them. This has dramatic consequences on functionality of ferroelectric-based devices such as ferroelectric memories or photodetectors. Therefore, to cancel out the Eimp, ferroelectric components are commonly built using symmetric contact configuration. Indeed, in this symmetric contact configuration, when measurements are done under time-varying electric fields of relatively low frequency, an archetypical symmetric single-step switching process is observed, indicating Eimp ≈ 0. However, we report here on the discovery that when measurements are performed at high frequency, a well-defined double-step switching is observed, indicating the presence of Eimp. We argue that this frequency dependence originates from short-living head-to-head or tail-to-tail ferroelectric capacitors in the device. We demonstrate that we can modulate Eimp and the life-time of head-to-head or tail-to-tail polarization configurations by adjusting the polarization screening charges by suitable illumination. These findings are of relevance to understand the effects of internal electric fields on pivotal ferroelectric properties, such as memory retention and photoresponse.

  10. Unravelling and controlling hidden imprint fields in ferroelectric capacitors.

    PubMed

    Liu, Fanmao; Fina, Ignasi; Bertacco, Riccardo; Fontcuberta, Josep

    2016-01-01

    Ferroelectric materials have a spontaneous polarization that can point along energetically equivalent, opposite directions. However, when ferroelectric layers are sandwiched between different metallic electrodes, asymmetric electrostatic boundary conditions may induce the appearance of an electric field (imprint field, Eimp) that breaks the degeneracy of the polarization directions, favouring one of them. This has dramatic consequences on functionality of ferroelectric-based devices such as ferroelectric memories or photodetectors. Therefore, to cancel out the Eimp, ferroelectric components are commonly built using symmetric contact configuration. Indeed, in this symmetric contact configuration, when measurements are done under time-varying electric fields of relatively low frequency, an archetypical symmetric single-step switching process is observed, indicating Eimp ≈ 0. However, we report here on the discovery that when measurements are performed at high frequency, a well-defined double-step switching is observed, indicating the presence of Eimp. We argue that this frequency dependence originates from short-living head-to-head or tail-to-tail ferroelectric capacitors in the device. We demonstrate that we can modulate Eimp and the life-time of head-to-head or tail-to-tail polarization configurations by adjusting the polarization screening charges by suitable illumination. These findings are of relevance to understand the effects of internal electric fields on pivotal ferroelectric properties, such as memory retention and photoresponse. PMID:27122309

  11. 48 CFR 16.204 - Fixed-price incentive contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Fixed-price incentive... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Fixed-Price Contracts 16.204 Fixed-price incentive contracts. A fixed-price incentive contract is a fixed-price contract that provides for adjusting profit...

  12. 48 CFR 16.204 - Fixed-price incentive contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Fixed-price incentive... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Fixed-Price Contracts 16.204 Fixed-price incentive contracts. A fixed-price incentive contract is a fixed-price contract that provides for adjusting profit...

  13. 48 CFR 16.204 - Fixed-price incentive contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Fixed-price incentive... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Fixed-Price Contracts 16.204 Fixed-price incentive contracts. A fixed-price incentive contract is a fixed-price contract that provides for adjusting profit...

  14. Optical simulation for a fixed spherical solar collector.

    PubMed

    Authier, B; Hill, L; Duban, M; Trarieux, P; Sarazin, M; Nadeau, P

    1979-09-15

    To calculate the absorber dimensions for a fixed spherical solar collector, an optical simulation of the raytracing type is proposed. The physical quantities, which have an effect upon these dimensions, are described as well as the measurement methods. Once the dimensions are determined, the incident flux on the absorber surface can be calculated by the same program in terms of different zenith distances. These calculations can be checked by comparing the calculated flux on the surface of the absorber with the measured flux at different points along the absorber aimed at the full moon instead of at the sun. Through the data obtained from the measurements, fluctuating points of high flux and permanent zones which receive double and triple reflection rays have been studied. PMID:20212809

  15. A comparison of carbide fracture during fixed depth and fixed load scratch tests

    SciTech Connect

    Prasad, S.V.; Kosel, T.H.

    1985-01-01

    In order to simulate abrasion of dual-phase materials containing large carbides under fixed depth conditions an apparatus has been designed and used to perform scratch tests at a fixed depth of cut on such materials. The scratch test consists of two support arms tipped with small steel balls held in contact with surface by /sup 700/ g, while the scratch tool is mounted on the tip of a central arm whose adjustable length allow control of the depth of cut. The scratch tool does not deflect significant when it encounters a large carbide. Scratch tests with the new apparatus have been performed on Co-base Stellite alloys containing large Cr-rich carbides, using individual particles of alumina as scratch tools to generate fixed depth scratches. A in situ SEM scratch test apparatus has also been used to genrate fixed load scratches. Comparison of the scratches shows that for comparable average scratch depths, under fixed load conditions the scratch tool deflects over the carbides without causing fracture, but that since it cannot deflect under fixed depth conditions it induces gross carbide fracture. Results suggest that the fixed depth scratch test can be successfully employed to simulate fixed depth abrasion, which has been previously shown to generate gross carbide fracture in these alloys. The in situ SEM scratch test simulates fixed load abrasion conditions such as those which occur in rubber wheel abrasion tests. 12 refs., 9 figs

  16. Combined Label-Free Quantitative Proteomics and microRNA Expression Analysis of Breast Cancer Unravel Molecular Differences with Clinical Implications.

    PubMed

    Gámez-Pozo, Angelo; Berges-Soria, Julia; Arevalillo, Jorge M; Nanni, Paolo; López-Vacas, Rocío; Navarro, Hilario; Grossmann, Jonas; Castaneda, Carlos A; Main, Paloma; Díaz-Almirón, Mariana; Espinosa, Enrique; Ciruelos, Eva; Fresno Vara, Juan Ángel

    2015-06-01

    Better knowledge of the biology of breast cancer has allowed the use of new targeted therapies, leading to improved outcome. High-throughput technologies allow deepening into the molecular architecture of breast cancer, integrating different levels of information, which is important if it helps in making clinical decisions. microRNA (miRNA) and protein expression profiles were obtained from 71 estrogen receptor-positive (ER(+)) and 25 triple-negative breast cancer (TNBC) samples. RNA and proteins obtained from formalin-fixed, paraffin-embedded tumors were analyzed by RT-qPCR and LC/MS-MS, respectively. We applied probabilistic graphical models representing complex biologic systems as networks, confirming that ER(+) and TNBC subtypes are distinct biologic entities. The integration of miRNA and protein expression data unravels molecular processes that can be related to differences in the genesis and clinical evolution of these types of breast cancer. Our results confirm that TNBC has a unique metabolic profile that may be exploited for therapeutic intervention. PMID:25883093

  17. Inadvertent tooth movement with fixed lingual retainers.

    PubMed

    Shaughnessy, Timothy G; Proffit, William R; Samara, Said A

    2016-02-01

    Fixed retainers are effective in maintaining the alignment of the anterior teeth more than 90% of the time, but they can produce inadvertent tooth movement that in the most severe instances requires orthodontic retreatment managed with a periodontist. This is different from relapse into crowding when a fixed retainer is lost. These problems arise when the retainer breaks but remains bonded to some or all teeth, or when an intact retainer is distorted by function or was not passive when bonded. In both instances, torque of the affected teeth is the predominant outcome. A fixed retainer made with dead soft wire is the least likely to create torque problems but is the most likely to break. Highly flexible twist wires bonded to all the teeth appear to be the most likely to produce inadvertent tooth movement, but this also can occur with stiffer wires bonded only to the canines. Orthodontists, general dentists, and patients should be aware of possible problems with fixed retainers, especially those with all teeth bonded, because the patient might not notice partial debonding. Regular observations of patients wearing fixed retainers by orthodontists in the short term and family dentists in the long term are needed. PMID:26827985

  18. Controlling Cyanobacterial Blooms in Hypertrophic Lake Taihu, China: Will Nitrogen Reductions Cause Replacement of Non-N2 Fixing by N2 Fixing Taxa?

    PubMed Central

    Paerl, Hans W.; Xu, Hai; Hall, Nathan S.; Zhu, Guangwei; Qin, Boqiang; Wu, Yali; Rossignol, Karen L.; Dong, Linghan; McCarthy, Mark J.; Joyner, Alan R.

    2014-01-01

    Excessive anthropogenic nitrogen (N) and phosphorus (P) inputs have caused an alarming increase in harmful cyanobacterial blooms, threatening sustainability of lakes and reservoirs worldwide. Hypertrophic Lake Taihu, China’s third largest freshwater lake, typifies this predicament, with toxic blooms of the non-N2 fixing cyanobacteria Microcystis spp. dominating from spring through fall. Previous studies indicate N and P reductions are needed to reduce bloom magnitude and duration. However, N reductions may encourage replacement of non-N2 fixing with N2 fixing cyanobacteria. This potentially counterproductive scenario was evaluated using replicate, large (1000 L), in-lake mesocosms during summer bloom periods. N+P additions led to maximum phytoplankton production. Phosphorus enrichment, which promoted N limitation, resulted in increases in N2 fixing taxa (Anabaena spp.), but it did not lead to significant replacement of non-N2 fixing with N2 fixing cyanobacteria, and N2 fixation rates remained ecologically insignificant. Furthermore, P enrichment failed to increase phytoplankton production relative to controls, indicating that N was the most limiting nutrient throughout this period. We propose that Microcystis spp. and other non-N2 fixing genera can maintain dominance in this shallow, highly turbid, nutrient-enriched lake by outcompeting N2 fixing taxa for existing sources of N and P stored and cycled in the lake. To bring Taihu and other hypertrophic systems below the bloom threshold, both N and P reductions will be needed until the legacy of high N and P loading and sediment nutrient storage in these systems is depleted. At that point, a more exclusive focus on P reductions may be feasible. PMID:25405474

  19. Radiative convection with a fixed heat flux

    NASA Astrophysics Data System (ADS)

    Aumaı̂tre, S.

    2001-10-01

    We have determined the marginal stability curve of convective instability in the usual Rayleigh-Bénard configuration with radiative transfer and a fixed total heat flux at the boundaries instead of a fixed temperature. In the Milne-Eddington approximation, radiative transfer introduces a new length scale and breaks the invariance of the Boussinesq equations under an arbitrary temperature shift, which occurs when the heat flux is fixed at the boundaries. The convergence to the limits where the non-radiative cases are expected is studied in this approximation. Then, using a second-order perturbative calculation, we show that the presence of radiation can change qualitatively the instability pattern: there is a range of optical parameters where the Cahn-Hillard equation is not anymore the one appropriate to describe the instability near the threshold.

  20. [Fixed-drug combinations for hypertension].

    PubMed

    Sato, Nobuyuki; Hasebe, Naoyuki

    2014-08-01

    The recent guidelines for the treatment of hypertension recommend a fixed-dose combination (polypill) therapy to achieve optimal blood pressure (BP) control. Among them, angiotensin receptor blockers (ARBs) with calcium channel blockers (CCBs) or diuretics are the representative recommended combination since each drug has evidence of reducing cardiovascular events. Recent studies using ambulatory blood pressure monitoring have also suggested that the fixed-dose ARB-based combination therapies with either CCBs or diuretics are well tolerated and effectively lower the BP throughout a 24-hour interval by their long-acting half-lives, nighttime BP lowering effect and improving adherence. It will become more important to use these fixed-dose antihypertensive drugs adequately for controlling the 24-hour blood pressure. PMID:25167756

  1. Unraveling the complexities of disaster management: a framework for critical social infrastructure to promote population health and resilience.

    PubMed

    O'Sullivan, Tracey L; Kuziemsky, Craig E; Toal-Sullivan, Darene; Corneil, Wayne

    2013-09-01

    Complexity is a useful frame of reference for disaster management and understanding population health. An important means to unraveling the complexities of disaster management is to recognize the interdependencies between health care and broader social systems and how they intersect to promote health and resilience before, during and after a crisis. While recent literature has expanded our understanding of the complexity of disasters at the macro level, few studies have examined empirically how dynamic elements of critical social infrastructure at the micro level influence community capacity. The purpose of this study was to explore empirically the complexity of disasters, to determine levers for action where interventions can be used to facilitate collaborative action and promote health among high risk populations. A second purpose was to build a framework for critical social infrastructure and develop a model to identify potential points of intervention to promote population health and resilience. A community-based participatory research design was used in nine focus group consultations (n = 143) held in five communities in Canada, between October 2010 and March 2011, using the Structured Interview Matrix facilitation technique. The findings underscore the importance of interconnectedness of hard and soft systems at the micro level, with culture providing the backdrop for the social fabric of each community. Open coding drawing upon the tenets of complexity theory was used to develop four core themes that provide structure for the framework that evolved; they relate to dynamic context, situational awareness and connectedness, flexible planning, and collaboration, which are needed to foster adaptive responses to disasters. Seven action recommendations are presented, to promote community resilience and population health. PMID:22898721

  2. Carbon-Fixing Reactions of Photosynthesis.

    PubMed

    2016-07-01

    Summaryplantcell;28/7/tpc.116.tt0716/FIG1F1fig1Photosynthesis in plants converts the energy of sunlight into chemical energy. Although photosynthesis involves many proteins and catalytic processes, it often is described as two sets of reactions, the light-dependent reactions and the carbon-fixing reactions. This lesson introduces the core biochemistry of the carbon-fixing reactions of photosynthesis, as well as its variations, C4 and CAM. Finally, it addresses how and why plants are affected by rising atmospheric CO2 levels, and research efforts to increase photosynthetic efficiency in current and future conditions. PMID:27493209

  3. The Hilbert scheme of points for supersingular abelian surfaces

    NASA Astrophysics Data System (ADS)

    Schröer, Stefan

    2009-04-01

    We study the geometry of Hilbert schemes of points on abelian surfaces and Beauville’s generalized Kummer varieties in positive characteristics. The main result is that, in characteristic two, the addition map from the Hilbert scheme of two points to the abelian surface is a quasifibration such that all fibers are nonsmooth. In particular, the corresponding generalized Kummer surface is nonsmooth, and minimally elliptic singularities occur in the supersingular case. We unravel the structure of the singularities in dependence of p-rank and a-number of the abelian surface. To do so, we establish a McKay Correspondence for Artin’s wild involutions on surfaces. Along the line, we find examples of canonical singularities that are not rational singularities.

  4. Vibration suppression of fixed-time jib crane maneuvers

    SciTech Connect

    Parker, G.G.; Petterson, B.; Dohrmann, C.R.; Robinett, R.D.

    1995-02-01

    A jib crane consists of a pendulum-like end line attached to a rotatable jib. Within this general category of cranes there exist devices with multiple degrees of freedom including variable load-line length and variable jib length. These cranes are commonly used for construction and transportation applications. Point-to-point payload maneuvers using jib cranes are performed so as not to excite the spherical pendulum modes of their cable and payload assemblies. Typically, these pendulum modes, although time-varying, exhibit low frequencies. The resulting maneuvers are therefore performed slowly, contributing to high construction and transportation costs. The crane considered here consists of a spherical pendulum attached to a rigid jib. The other end of the jib is attached to a direct drive motor for generating rotational motion. A general approach is presented for determining the open-loop trajectories for the jib rotation for accomplishing fixed-time, point-to-point, residual oscillation free, symmetric maneuvers. These residual oscillation free trajectories purposely excite the pendulum modes in such a way that at the end of the maneuver the oscillatory degrees of freedom are quiescent. Simulation results are presented with experimental verification.

  5. Management strategy 3: fixed rate fertilizer applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous chapters outlined management strategies for pond fertilization that take into account specific individual pond nutrient needs. Those methods would most likely be more ecologically efficient than a pre-determined fixed-rate nutrient addition strategy. However, the vast majority of available ...

  6. Fixed Drug Eruption Due to Ornidazole

    PubMed Central

    Gupta, Ramji

    2014-01-01

    A 56-year-old male developed an ulcer on his glans penis and mucosae of upper and lower lips 3 days after taking ofloxacin, cephalexin, and ornidazole. Clinically, a provisional diagnosis of fixed drug eruption was made. The causative drug was confirmed by an oral provocation test which triggered a reactivation of all lesions only with ornidazole. PMID:25484435

  7. Fixing the Shadows While Moving the Gnomon

    ERIC Educational Resources Information Center

    Gangui, Alejandro

    2015-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows…

  8. Why to Treat Subjects as Fixed Effects

    ERIC Educational Resources Information Center

    Adelman, James S.; Estes, Zachary

    2015-01-01

    Adelman, Marquis, Sabatos-DeVito, and Estes (2013) collected word naming latencies from 4 participants who read 2,820 words 50 times each. Their recommendation and practice was that R2 targets set for models should take into account subject idiosyncrasies as replicable patterns, equivalent to a subjects-as-fixed-effects assumption. In light of an…

  9. Long-term fixed income market structure

    NASA Astrophysics Data System (ADS)

    Grilli, Luca

    2004-02-01

    Long-term fixed income market securities present a strong positive correlation in daily returns. By using a metrical approach and considering “modified” time series, I show how it is possible to show a more complex structure which depends strictly on the maturity date.

  10. Physics landscape-fixed target energies

    SciTech Connect

    Berger, E.L.

    1989-10-01

    An introductory review is presented of physics issues and opportunities at Fermilab fixed-target energies. Included are discussions of precision electroweak studies; deep inelastic lepton scattering; heavy quark production, spectroscopy, and decays; perturbative QCD; prompt photon production; massive lepton production; and spin dependence. 79 refs., 7 figs.

  11. Fixed drug eruption against rupatadine fumarate.

    PubMed

    Fidan, Vural; Fidan, Tulin

    2011-09-01

    Second generation of antihistaminics have better therapeutic efficacy and more predictable pharmacological responses at lower doses than older compounds. However, new compounds have a reduced adverse reaction profile; clinicians can also encounter some unexpected adverse effects of these newer compounds. We report the first case of fixed drug eruption of rupatadine fumarate, which was confirmed by oral provocation test. PMID:21959412

  12. 29 CFR 1910.27 - Fixed ladders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... details shall be such as to prevent or minimize the accumulation of water on wood parts. (iii) When... and fastenings. (2) Design stresses. Design stresses for wood components of ladders shall not exceed those specified in § 1910.25. All wood parts of fixed ladders shall meet the requirements of §...

  13. 29 CFR 1910.27 - Fixed ladders.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... details shall be such as to prevent or minimize the accumulation of water on wood parts. (iii) When... and fastenings. (2) Design stresses. Design stresses for wood components of ladders shall not exceed those specified in § 1910.25. All wood parts of fixed ladders shall meet the requirements of §...

  14. 29 CFR 1910.27 - Fixed ladders.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... details shall be such as to prevent or minimize the accumulation of water on wood parts. (iii) When... and fastenings. (2) Design stresses. Design stresses for wood components of ladders shall not exceed those specified in § 1910.25. All wood parts of fixed ladders shall meet the requirements of §...

  15. 29 CFR 1910.27 - Fixed ladders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... details shall be such as to prevent or minimize the accumulation of water on wood parts. (iii) When... and fastenings. (2) Design stresses. Design stresses for wood components of ladders shall not exceed those specified in § 1910.25. All wood parts of fixed ladders shall meet the requirements of §...

  16. Deep Learning Experiences within a Fixed Schedule

    ERIC Educational Resources Information Center

    Green, Julie; Olmstead, Laurie

    2011-01-01

    Two and a half years ago, elementary school librarians in the Birmingham Public School district (Troy, Michigan) had to change to a fixed schedule for half the day with kindergarten through second grade students. This change was due to cutbacks and the need for common planning time among classroom teachers. School librarians found themselves…

  17. Stress tolerant crops from nitrogen fixing trees

    SciTech Connect

    Becker, R.; Saunders, R.M.

    1983-01-01

    Notes are given on the nutritional quality and uses of: pods of Geoffroea decorticans, a species tolerant of saline and limed soils and saline water; seeds of Olneya tesota which nodulates readily and fixes nitrogen and photosynthesizes at low water potential; and pods of Prosopis chilensis and P. tamarugo which tolerate long periods without rain. 3 references.

  18. Fixing Advising: A Model for Faculty Advising

    ERIC Educational Resources Information Center

    Crocker, Robert M.; Kahla, Marlene; Allen, Charlotte

    2014-01-01

    This paper addresses mandates to fix the advising process with a focus on faculty advising systems. Measures of student success and satisfaction, administrative issues, and faculty concerns are among the many factors discussed. Regression analysis is used to explore long-voiced faculty complaints that students do not follow advice. A case study is…

  19. Fixed Versus Flexible MMPI Diagnostic Rules.

    ERIC Educational Resources Information Center

    Hsu, Louis M.

    1988-01-01

    Demonstrates the consequences on total misdiagnosis rates of using conventional (fixed) rather than flexible (Bayesian) rules when using the Minnesota Multiphasic Personality Inventory in diagnosis. Concludes that the range of base rates and the separation of distributions of normal and abnormal scores affect the difference in the misdiagnosis…

  20. Exterior building details of Building A; east façade: fixed fiveoverfive ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior building details of Building A; east façade: fixed five-over-five wood windows with five-light hoppers with concrete sills; westerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  1. Determinants of Human Fixed-Interval Performance Following Varied Exposure to Reinforcement Schedules

    ERIC Educational Resources Information Center

    Torgrud, Laine J.; Holborn, Stephen W.; Zak, Robert D.

    2006-01-01

    Undergraduates given accurate instructions pressed keys for token points under either a variety of reinforcement schedules (variety training) or under a single schedule. Response rates on a fixed-interval (FI) test schedule then were assessed. Experiment 1 compared variety training inclusive of FI-optimal rates (functional) to training excluding…

  2. Unraveling dual feeding associated molecular complexity of salivary glands in the mosquito Anopheles culicifacies

    PubMed Central

    Sharma, Punita; Sharma, Swati; Mishra, Ashwani Kumar; Thomas, Tina; Das De, Tanwee; Rohilla, Suman Lata; Singh, Namita; Pandey, Kailash C.; Valecha, Neena; Dixit, Rajnikant

    2015-01-01

    ABSTRACT Mosquito salivary glands are well known to facilitate meal acquisition, however the fundamental question on how adult female salivary gland manages molecular responses during sugar versus blood meal uptake remains unanswered. To investigate these responses, we analyzed a total of 58.5 million raw reads generated from two independent RNAseq libraries of the salivary glands collected from 3–4 day-old sugar and blood fed Anopheles culicifacies mosquitoes. Comprehensive functional annotation analysis of 10,931 contigs unraveled that salivary glands may encode diverse nature of proteins in response to distinct physiological feeding status. Digital gene expression analysis and PCR validation indicated that first blood meal significantly alters the molecular architecture of the salivary glands. Comparative microscopic analysis also revealed that first blood meal uptake not only causes an alteration of at least 12–22% of morphological features of the salivary glands but also results in cellular changes e.g. apoptosis, confirming together that adult female salivary glands are specialized organs to manage meal specific responses. Unraveling the underlying mechanism of mosquito salivary gene expression, controlling dual feeding associated responses may provide a new opportunity to control vector borne diseases. PMID:26163527

  3. Unraveling dual feeding associated molecular complexity of salivary glands in the mosquito Anopheles culicifacies.

    PubMed

    Sharma, Punita; Sharma, Swati; Mishra, Ashwani Kumar; Thomas, Tina; Das De, Tanwee; Rohilla, Suman Lata; Singh, Namita; Pandey, Kailash C; Valecha, Neena; Dixit, Rajnikant

    2015-01-01

    Mosquito salivary glands are well known to facilitate meal acquisition, however the fundamental question on how adult female salivary gland manages molecular responses during sugar versus blood meal uptake remains unanswered. To investigate these responses, we analyzed a total of 58.5 million raw reads generated from two independent RNAseq libraries of the salivary glands collected from 3-4 day-old sugar and blood fed Anopheles culicifacies mosquitoes. Comprehensive functional annotation analysis of 10,931 contigs unraveled that salivary glands may encode diverse nature of proteins in response to distinct physiological feeding status. Digital gene expression analysis and PCR validation indicated that first blood meal significantly alters the molecular architecture of the salivary glands. Comparative microscopic analysis also revealed that first blood meal uptake not only causes an alteration of at least 12-22% of morphological features of the salivary glands but also results in cellular changes e.g. apoptosis, confirming together that adult female salivary glands are specialized organs to manage meal specific responses. Unraveling the underlying mechanism of mosquito salivary gene expression, controlling dual feeding associated responses may provide a new opportunity to control vector borne diseases. PMID:26163527

  4. 46 CFR 28.260 - Electronic position fixing devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Electronic position fixing devices. 28.260 Section 28... Trade § 28.260 Electronic position fixing devices. Each vessel 79 feet (24 meters) or more in length must be equipped with an electronic position fixing device capable of providing accurate fixes for...

  5. 46 CFR 28.260 - Electronic position fixing devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Electronic position fixing devices. 28.260 Section 28... Trade § 28.260 Electronic position fixing devices. Each vessel 79 feet (24 meters) or more in length must be equipped with an electronic position fixing device capable of providing accurate fixes for...

  6. 46 CFR 28.260 - Electronic position fixing devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Electronic position fixing devices. 28.260 Section 28... Trade § 28.260 Electronic position fixing devices. Each vessel 79 feet (24 meters) or more in length must be equipped with an electronic position fixing device capable of providing accurate fixes for...

  7. 46 CFR 28.260 - Electronic position fixing devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Electronic position fixing devices. 28.260 Section 28... Trade § 28.260 Electronic position fixing devices. Each vessel 79 feet (24 meters) or more in length must be equipped with an electronic position fixing device capable of providing accurate fixes for...

  8. 46 CFR 28.260 - Electronic position fixing devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Electronic position fixing devices. 28.260 Section 28... Trade § 28.260 Electronic position fixing devices. Each vessel 79 feet (24 meters) or more in length must be equipped with an electronic position fixing device capable of providing accurate fixes for...

  9. 48 CFR 16.403 - Fixed-price incentive contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Fixed-price incentive... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 16.403 Fixed-price incentive contracts. (a) Description. A fixed-price incentive contract is a fixed-price contract that provides...

  10. 48 CFR 1852.216-78 - Firm fixed price.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Firm fixed price. 1852.216... 1852.216-78 Firm fixed price. As prescribed in 1816.202-70, insert the following clause: Firm Fixed Price (DEC 1988) The total firm fixed price of this contract is $ . (End of clause)...

  11. 48 CFR 16.403 - Fixed-price incentive contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Fixed-price incentive... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 16.403 Fixed-price incentive contracts. (a) Description. A fixed-price incentive contract is a fixed-price contract that provides...

  12. 48 CFR 52.216-9 - Fixed Fee-Construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Fixed Fee-Construction. 52....216-9 Fixed Fee—Construction. As prescribed in 16.307(c), insert the following clause in solicitations and contracts when a cost-plus-fixed-fee construction contract is contemplated: Fixed...

  13. Unravelling DNA

    NASA Astrophysics Data System (ADS)

    Conroy, Rs; Danilowicz, C.

    2004-04-01

    The forces involved in the biology of life are carefully balanced between stopping thermal fluctuations ripping our DNA apart and having bonds weak enough to allow enzymes to function. The application of recently developed techniques for measuring piconewton forces and imaging at the nanometre scale on a molecule-by-molecule basis has dramatically increased the impact of single-molecule biophysics. This article describes the most commonly used techniques for imaging and manipulating single biomolecules. Using these techniques, the mechanical properties of DNA can be investigated, for example through measurements of the forces required to stretch and unzip the DNA double helix. These properties determine the ease with which DNA can be folded into the cell nucleus and the size and complexity of the accompanying cellular machinery. Part of this cellular machinery is enzymes, which manipulate, repair and transcribe the DNA helix. Enzymatic function is increasingly being investigated at the single molecule level to give better understanding of the forces and processes involved in the genetic cycle. One of the challenges is to transfer this understanding of single molecules into living systems. Already there have been some notable successes, such as the development of techniques for gene expression through the application of mechanical forces to cells, and the imaging and control of viral infection of a cell. This understanding and control of DNA has also been used to design molecules, which can self-assemble into a range of structures.

  14. Anomalous scaling at nonthermal fixed points of Burgers' and Gross-Pitaevskii turbulence

    NASA Astrophysics Data System (ADS)

    Mathey, Steven; Gasenzer, Thomas; Pawlowski, Jan M.

    2015-08-01

    Scaling in the dynamical properties of complex many-body systems has been of strong interest since turbulence phenomena became the subject of systematic mathematical studies. In this article, dynamical critical phenomena far from equilibrium are investigated with functional renormalization-group equations. The focus is set on scaling solutions of the stochastic driven-dissipative Burgers equation and their relation to solutions known in the literature for Burgers' and Kardar-Parisi-Zhang dynamics. We furthermore relate superfluid as well as acoustic turbulence described by the Gross-Pitaevskii model to known analytic and numerical results for scaling solutions. In this way, the canonical Kolmogorov exponent 5/3 for the energy cascade in superfluid turbulence is obtained analytically. We also get results for anomalous exponents of acoustic and quantum turbulence. These are consistent with existing experimental data. Our results should be relevant for future experiments with, e.g., exciton-polariton condensates in solid-state systems as well as with ultracold atomic gases.

  15. Balance between absorbing and positive fixed points in resource consumption models

    NASA Astrophysics Data System (ADS)

    Behar, Hilla; Shnerb, Nadav; Louzoun, Yoram

    2012-09-01

    The effect of resource usage on economic growth has been studied in multiple models. However, the generic effect of improving resource usage efficacy through improved technical skills has not been studied in detail. We here analyze a model incorporating resource usage by capital and the parallel production of technical skill in order to study the effect of improving the efficacy of resources usage with advanced technologies. We show that a practically inevitable result of such a model is that improving the resource usage efficacy leads to a lower steady-state level of resources. A surprising conclusion from ordinary differential equations realization of the model is an extreme sensitivity to parameters, where a small parameter change can lead to an irreversible state through a hysteresis mechanism between a scenario of a collapse of the economy and a scenario of sustainable economy. This sensitivity is lost when spatial stochastic simulations are performed. In the stochastic regime the two scenarios coexist, with different fractions of the lattice residing in each state. Changing parameters smoothly changes the fraction of lattice sites in each state. The transition between the collapsed economy and the sustainable one is not symmetrical. Escape from the collapsed situation can only occur through diffusion from neighboring sustained lattice sites. On the other hand, the collapse can occur even in the absence of diffusion. This difference leads to diffusion dependent capital growth, where an optimal capital is obtained for middiffusion values. Such a transition may actually be generic phenomena in ecological and economic systems.

  16. Analysis and optimisation for inerter-based isolators via fixed-point theory and algebraic solution

    NASA Astrophysics Data System (ADS)

    Hu, Yinlong; Chen, Michael Z. Q.; Shu, Zhan; Huang, Lixi

    2015-06-01

    This paper is concerned with the problem of analysis and optimisation of the inerter-based isolators based on a "uni-axial" single-degree-of-freedom isolation system. In the first part, in order to gain an in-depth understanding of inerter from the prospective of vibration, the frequency responses of both parallel-connected and series-connected inerters are analysed. In the second part, three other inerter-based isolators are introduced and the tuning procedures in both the H∞ optimisation and the H2 optimisation are proposed in an analytical manner. The achieved H2 and H∞ performance of the inerter-based isolators is superior to that achieved by the traditional dynamic vibration absorber (DVA) when the same inertance-to-mass (or mass) ratio is considered. Moreover, the inerter-based isolators have two unique properties, which are more attractive than the traditional DVA: first, the inertance-to-mass ratio of the inerter-based isolators can easily be larger than the mass ratio of the traditional DVA without increasing the physical mass of the whole system; second, there is no need to mount an additional mass on the object to be isolated.

  17. Final Report for "Infrared Fixed Points in Multiflavor Lattice Gauge Theory"

    SciTech Connect

    Meurice, Yannick; Sinclair, Donald K.

    2013-09-27

    The goal of the grant was to apply methods that we have developed with spin and pure gauge models to models with dynamical fermions which are considered as candidates for an alternative to the Higgs mechanism. The work on SU(3) with fundamental quarks and with sextet quarks is described.

  18. LONG PATH DIFFERENTIAL OPTICAL ABSORPTION SPECTROMETER AND EPA-APPROVED FIXED POINT METHODS INTERCOMPARISON

    EPA Science Inventory

    Differential optical absorption spectrometry (DOAS) has been used by a number of investigators over the past 10 years to measure a wide range of gaseous air pollutants. ecently OPSIS AB, Lund, Sweden, has developed and made commercially available DOAS instrument that has a number...

  19. Periodic solutions in the Kovalevskaya case of a rigid body in rotation about a fixed point

    NASA Astrophysics Data System (ADS)

    El-Sabaa, F. M. F.

    1992-07-01

    The method of small parameters introduced by Poincare is used to obtain the period solution of the problem of a rigid body in the Kovalevskaya case with k (the Kovalevskaya constant of integration) as a small parameter. The asymptotic solution is obtained in terms of elliptic integrals for the (complete integrable) Kovalevskaya top.

  20. Fixed points and limit cycles in the population dynamics of lysogenic viruses and their hosts.

    PubMed

    Wang, Zhenyu; Goldenfeld, Nigel

    2010-07-01

    Starting with stochastic rate equations for the fundamental interactions between microbes and their viruses, we derive a mean-field theory for the population dynamics of microbe-virus systems, including the effects of lysogeny. In the absence of lysogeny, our model is a generalization of that proposed phenomenologically by Weitz and Dushoff. In the presence of lysogeny, we analyze the possible states of the system, identifying a limit cycle, which we interpret physically. To test the robustness of our mean-field calculations to demographic fluctuations, we have compared our results with stochastic simulations using the Gillespie algorithm. Finally, we estimate the range of parameters that delineate the various steady states of our model. PMID:20866659

  1. Fixed points and limit cycles in the population dynamics of lysogenic viruses and their hosts

    NASA Astrophysics Data System (ADS)

    Wang, Zhenyu; Goldenfeld, Nigel

    2010-07-01

    Starting with stochastic rate equations for the fundamental interactions between microbes and their viruses, we derive a mean-field theory for the population dynamics of microbe-virus systems, including the effects of lysogeny. In the absence of lysogeny, our model is a generalization of that proposed phenomenologically by Weitz and Dushoff. In the presence of lysogeny, we analyze the possible states of the system, identifying a limit cycle, which we interpret physically. To test the robustness of our mean-field calculations to demographic fluctuations, we have compared our results with stochastic simulations using the Gillespie algorithm. Finally, we estimate the range of parameters that delineate the various steady states of our model.

  2. Competition Between Transients in the Rate of Approach to a Fixed Point*

    PubMed Central

    Day, Judy; Rubin, Jonathan E.; Chow, Carson C.

    2009-01-01

    The goal of this paper is to provide and apply tools for analyzing a specific aspect of transient dynamics not covered by previous theory. The question we address is whether one component of a perturbed solution to a system of differential equations can overtake the corresponding component of a reference solution as both converge to a stable node at the origin, given that the perturbed solution was initially farther away and that both solutions are nonnegative for all time. We call this phenomenon tolerance, for its relation to a biological effect. We show using geometric arguments that tolerance will exist in generic linear systems with a complete set of eigenvectors and in excitable nonlinear systems. We also define a notion of inhibition that may constrain the regions in phase space where the possibility of tolerance arises in general systems. However, these general existence theorems do not not yield an assessment of tolerance for specific initial conditions. To address that issue, we develop some analytical tools for determining if particular perturbed and reference solution initial conditions will exhibit tolerance. PMID:20011076

  3. Equilibria of three constrained point charges

    NASA Astrophysics Data System (ADS)

    Khimshiashvili, G.; Panina, G.; Siersma, D.

    2016-08-01

    We study the critical points of Coulomb energy considered as a function on configuration spaces associated with certain geometric constraints. Two settings of such kind are discussed in some detail. The first setting arises by considering polygons of fixed perimeter with freely sliding positively charged vertices. The second one is concerned with triples of positive charges constrained to three concentric circles. In each of these cases the Coulomb energy is generically a Morse function. We describe the minima and other stationary points of Coulomb energy and show that, for three charges, a pitchfork bifurcation takes place accompanied by an effect of the Euler's Buckling Beam type.

  4. 24 CFR 84.80 - Conditions for use of Lump Sum (fixed price or fixed amount) grants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (fixed price or fixed amount) grants. 84.80 Section 84.80 Housing and Urban Development Office of the... AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Use of Lump Sum Grants § 84.80 Conditions for use of Lump Sum (fixed price or fixed amount) grants. (a) Heads...

  5. Fixed-Cell Imaging of Schizosaccharomyces pombe.

    PubMed

    Hagan, Iain M; Bagley, Steven

    2016-01-01

    The acknowledged genetic malleability of fission yeast has been matched by impressive cytology to drive major advances in our understanding of basic molecular cell biological processes. In many of the more recent studies, traditional approaches of fixation followed by processing to accommodate classical staining procedures have been superseded by live-cell imaging approaches that monitor the distribution of fusion proteins between a molecule of interest and a fluorescent protein. Although such live-cell imaging is uniquely informative for many questions, fixed-cell imaging remains the better option for others and is an important-sometimes critical-complement to the analysis of fluorescent fusion proteins by live-cell imaging. Here, we discuss the merits of fixed- and live-cell imaging as well as specific issues for fluorescence microscopy imaging of fission yeast. PMID:27371603

  6. Fixed drug eruptions with intraoral presentation

    PubMed Central

    Srivastava, Rahul; Bihari, Manorama; Bhuvan, Jyoti; Saad, Ahmed

    2015-01-01

    Fixed-drug eruption (FDE) is an unusual and rare adverse drug reaction. This type of reaction is actually a delayed type of hypersensitivity reaction that occurs as lesions recurring at the same skin site due to repeated intake of an offending drug. Here is a case report of a 58-year-old male patient who developed intraoral FDEs after ingestion of the first dose of ornidazole. PMID:26097341

  7. Azithromycin induced bullous fixed drug eruption

    PubMed Central

    Das, Anupam; Sancheti, Karan; Podder, Indrashis; Das, Nilay Kanti

    2016-01-01

    Fixed drug eruption (FDE) is a common type of drug eruption seen in skin clinics. It is characterized by solitary or multiple, round to oval erythematous patches with dusky red centers, some of which may progress to bulla formation. Bullous FDE may be caused by a number of drugs. We hereby describe a case of azithromycin-induced bullous FDE; to the best of our knowledge, this is the first such case being reported. PMID:26997729

  8. Topology of the Two Fixed Centers Problem

    NASA Astrophysics Data System (ADS)

    Cordero, A.; Martínez Alfaro, J.; Vindel, P.

    2002-02-01

    In this paper we give a complete topological characterization of the Two Fixed Centers (TFC) problem flow. This characterization is based on the link formed by some basic periodic orbits. The Restricted Circular Three-Body (RCTB) problem is considered as a perturbation of the TFC in the case of two primaries with equal masses. The basic periodic orbits of the integrable problem can be continued in the non-integrable one.

  9. RSRM nozzle fixed housing cooldown test

    NASA Technical Reports Server (NTRS)

    Bolieau, D. J.

    1989-01-01

    Flight 5 aft segments with nozzles were exposed to -17 F temperatures while awaiting shipment to KSC in February, 1989. No records were found which show that any previous nozzles were exposed to air temperatures as low as those seen by the Flight 5 nozzles. Thermal analysis shows that the temperature of the fixed housing, and forward and aft exit cone components dropped as low as -10 F. Structural analysis of the nozzles at these low temperatures show the forward and aft exit cone adhesive bonds to have a positive margin of safety, based on a 2.0 safety factor. These analyses show the normal and shear stresses in the fixed housing bond as low values. However, the hoop and meridinal stresses were predicted to be in the 4000 psi range; the failure stress allowable of EA913NA adhesive at -7 F. If the bonds did break in directions perpendicular to the surfaces, called bond crazing, no normal bond strength would be lost. Testing was conducted in two phases, showing that no degradation to the adhesive bonds occurred while the Flight 5 nozzles were subjected to subzero temperatures. The results of these tests are documented. Phase 1 testing cooled a full-scale RSRM insulated fixed housing to -13 F, with extensive bondline inspections. Phase 2 testing cooled the witness panel adhesive tensile buttions to -13 F, with failure strengths recorded before, during, and after the cooldown.

  10. Fixed-combination and emerging glaucoma therapies.

    PubMed

    Woodward, David F; Chen, June

    2007-05-01

    Ocular hypotensive agents are the only approved pharmacotherapy for glaucoma. Despite significant advances during the past two decades, a large proportion of glaucoma patients require more than one drug. The most recent additions to the armamentarium of antiglaucoma drugs are fixed-combination products for the glaucoma patient who is insufficiently responsive to monotherapy. Fixed-combination products have the combined efficacy of two ocular hypotensive drugs, and the convenience of a two-drug treatment regimen in a single container, which may aid patient adherence to treatment. Available fixed-combination products consist of timolol 0.5% as an invariant with brimonidine 0.2%, dorzolamide 2%, travoprost 0.004%, latanoprost 0.005% or bimatoprost 0.03%. Research on more advanced antiglaucoma medications continues. Promising new directions appear to be the Rho-kinase inhibitors, microtubule-disrupting agents, serotonergics and cannabimimetics. Efforts continue to improve existing antiglaucoma drugs in an attempt to design second-generation cholinomimetics, adrenergics, prostaglandins and prostamides. PMID:17604504

  11. Zirconia in fixed prosthesis. A literature review

    PubMed Central

    Román-Rodríguez, Juan L.; Ferreiroa, Alberto; Solá-Ruíz, María F.; Fons-Font, Antonio

    2014-01-01

    Statement of problem: Evidence is limited on the efficacy of zirconia-based fixed dental prostheses. Objective: To carry out a literature review of the behavior of zirconium oxide dental restorations. Material and Methods: This literature review searched the Pubmed, Scopus, Medline and Cochrane Library databases using key search words “zirconium oxide,” “zirconia,” “non-metal restorations,” “ceramic oxides,” “veneering ceramic,” “zirconia-based fixed dental prostheses”. Both in vivo and in vitro studies into zirconia-based prosthodontic restoration behavior were included. Results: Clinical studies have revealed a high rate of fracture for porcelain-veneered zirconia-based restorations that varies between 6% and 15% over a 3- to 5-year period, while for ceramo-metallic restorations the fracture rate ranges between 4 and 10% over ten years. These results provoke uncertainty as to the long-term prognosis for this material in the oral medium. The cause of veneering porcelain fractures is unknown but hypothetically they could be associated with bond failure between the veneer material and the zirconia sub-structure. Key words:Veneering ceramic, zirconia-based ceramic restoration, crown, zirconia, tooth-supported fixed prosthesis. PMID:24596638

  12. Floating Point Control Library

    Energy Science and Technology Software Center (ESTSC)

    2007-08-02

    Floating Point Control is a Library that allows for the manipulation of floating point unit exception masking funtions control exceptions in both the Streaming "Single Instruction, Multiple Data" Extension 2 (SSE2) unit and the floating point unit simultaneously. FPC also provides macros to set floating point rounding and precision control.

  13. Voltage controlled core reversal of fixed magnetic skyrmions without a magnetic field

    PubMed Central

    Bhattacharya, Dhritiman; Al-Rashid, Md Mamun; Atulasimha, Jayasimha

    2016-01-01

    Using micromagnetic simulations we demonstrate core reversal of a fixed magnetic skyrmion by modulating the perpendicular magnetic anisotropy of a nanomagnet with an electric field. We can switch reversibly between two skyrmion states and two ferromagnetic states, i.e. skyrmion states with the magnetization of the core pointing down/up and periphery pointing up/down, and ferromagnetic states with magnetization pointing up/down, by sequential increase and decrease of the perpendicular magnetic anisotropy. The switching between these states is explained by the fact that the spin texture corresponding to each of these stable states minimizes the sum of the magnetic anisotropy, demagnetization, Dzyaloshinskii-Moriya interaction (DMI) and exchange energies. This could lead to the possibility of energy efficient nanomagnetic memory and logic devices implemented with fixed skyrmions without using a magnetic field and without moving skyrmions with a current. PMID:27506159

  14. Voltage controlled core reversal of fixed magnetic skyrmions without a magnetic field.

    PubMed

    Bhattacharya, Dhritiman; Al-Rashid, Md Mamun; Atulasimha, Jayasimha

    2016-01-01

    Using micromagnetic simulations we demonstrate core reversal of a fixed magnetic skyrmion by modulating the perpendicular magnetic anisotropy of a nanomagnet with an electric field. We can switch reversibly between two skyrmion states and two ferromagnetic states, i.e. skyrmion states with the magnetization of the core pointing down/up and periphery pointing up/down, and ferromagnetic states with magnetization pointing up/down, by sequential increase and decrease of the perpendicular magnetic anisotropy. The switching between these states is explained by the fact that the spin texture corresponding to each of these stable states minimizes the sum of the magnetic anisotropy, demagnetization, Dzyaloshinskii-Moriya interaction (DMI) and exchange energies. This could lead to the possibility of energy efficient nanomagnetic memory and logic devices implemented with fixed skyrmions without using a magnetic field and without moving skyrmions with a current. PMID:27506159

  15. Voltage controlled core reversal of fixed magnetic skyrmions without a magnetic field

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Dhritiman; Al-Rashid, Md Mamun; Atulasimha, Jayasimha

    2016-08-01

    Using micromagnetic simulations we demonstrate core reversal of a fixed magnetic skyrmion by modulating the perpendicular magnetic anisotropy of a nanomagnet with an electric field. We can switch reversibly between two skyrmion states and two ferromagnetic states, i.e. skyrmion states with the magnetization of the core pointing down/up and periphery pointing up/down, and ferromagnetic states with magnetization pointing up/down, by sequential increase and decrease of the perpendicular magnetic anisotropy. The switching between these states is explained by the fact that the spin texture corresponding to each of these stable states minimizes the sum of the magnetic anisotropy, demagnetization, Dzyaloshinskii-Moriya interaction (DMI) and exchange energies. This could lead to the possibility of energy efficient nanomagnetic memory and logic devices implemented with fixed skyrmions without using a magnetic field and without moving skyrmions with a current.

  16. A proper fixed functional for four-dimensional Quantum Einstein Gravity

    NASA Astrophysics Data System (ADS)

    Demmel, Maximilian; Saueressig, Frank; Zanusso, Omar

    2015-08-01

    Realizing a quantum theory for gravity based on Asymptotic Safety hinges on the existence of a non-Gaussian fixed point of the theory's renormalization group flow. In this work, we use the functional renormalization group equation for the effective average action to study the fixed point underlying Quantum Einstein Gravity at the functional level including an infinite number of scale-dependent coupling constants. We formulate a list of guiding principles underlying the construction of a partial differential equation encoding the scale-dependence of f( R)-gravity. We show that this equation admits a unique, globally well-defined fixed functional describing the non-Gaussian fixed point at the level of functions of the scalar curvature. This solution is constructed explicitly via a numerical double-shooting method. In the UV, this solution is in good agreement with results from polynomial expansions including a finite number of coupling constants, while it scales proportional to R 2, dressed up with non-analytic terms, in the IR. We demonstrate that its structure is mainly governed by the conformal sector of the flow equation. The relation of our work to previous, partial constructions of similar scaling solutions is discussed.

  17. Human choice in "counterintuitive" situations: fixed- versus progressive-ratio schedules.

    PubMed Central

    Wanchisen, B A; Tatham, T A; Hineline, P N

    1992-01-01

    College undergraduates were given repeated opportunities to choose between a fixed-ratio and a progressive-ratio schedule of reinforcement. Completions of a progressive-ratio schedule produced points (exchangeable for money) and incremented that response requirement by 20 responses with each consecutive choice. In the reset condition, completion of a fixed ratio produced the same number of points and also reset the progressive ratio back to its initial value. In the no-reset condition, the progressive ratio continued to increase by increments of 20 throughout the session with each successive selection of this schedule, irrespective of fixed-ratio choices. Subjects' schedule choices were sensitive to parametric manipulations of the size of the fixed-ratio schedule and were consistent with predictions made on the basis of minimizing the number of responses emitted per point earned, which is a principle of most optimality theories. Also, the present results suggest that if data from human performances are to be compared with results for other species, humans should be exposed to schedules of reinforcement for long periods of time, as is commonly done with nonhuman subjects. PMID:1645102

  18. Unraveling the Motivational Effects and Challenges of Web-Based Collaborative Inquiry Learning across Different Groups of Learners

    ERIC Educational Resources Information Center

    Raes, Annelies; Schellens, Tammy

    2015-01-01

    This study deals with the implementation of a web-based collaborative inquiry (WISE) project in secondary science education and unravels the contribution and challenges of this learning approach to foster students' motivation to learn science, and its relation with student and class-level characteristics. An empirical mixed methods study in 13…

  19. A complete and explicit solution to the three-dimensional problem of two fixed centres

    NASA Astrophysics Data System (ADS)

    Biscani, Francesco; Izzo, Dario

    2016-02-01

    We present for the first time an explicit, complete and closed-form solution to the three-dimensional problem of two fixed centres, based on Weierstrass elliptic and related functions. With respect to previous treatments of the problem, our solution is exact, valid for all initial conditions and physical parameters of the system (including unbounded orbits and repulsive forces), and expressed via a unique set of formulae. Various properties of the three-dimensional problem of two fixed centres are investigated and analysed, with a particular emphasis on quasi-periodic and periodic orbits, regions of motion and equilibrium points.

  20. Myofascial trigger point pain.

    PubMed

    Jaeger, Bernadette

    2013-01-01

    Myofascial trigger point pain is an extremely prevalent cause of persistent pain disorders in all parts of the body, not just the head, neck, and face. Features include deep aching pain in any structure, referred from focally tender points in taut bands of skeletal muscle (the trigger points). Diagnosis depends on accurate palpation with 2-4 kg/cm2 of pressure for 10 to 20 seconds over the suspected trigger point to allow the referred pain pattern to develop. In the head and neck region, cervical muscle trigger points (key trigger points) often incite and perpetuate trigger points (satellite trigger points) and referred pain from masticatory muscles. Management requires identification and control of as many perpetuating factors as possible (posture, body mechanics, psychological stress or depression, poor sleep or nutrition). Trigger point therapies such as spray and stretch or trigger point injections are best used as adjunctive therapy. PMID:24864393

  1. Unraveling the storage mechanism in organic carbonyl electrodes for sodium-ion batteries

    PubMed Central

    Wu, Xiaoyan; Jin, Shifeng; Zhang, Zhizhen; Jiang, Liwei; Mu, Linqin; Hu, Yong-Sheng; Li, Hong; Chen, Xiaolong; Armand, Michel; Chen, Liquan; Huang, Xuejie

    2015-01-01

    Organic carbonyl compounds represent a promising class of electrode materials for secondary batteries; however, the storage mechanism still remains unclear. We take Na2C6H2O4 as an example to unravel the mechanism. It consists of alternating Na-O octahedral inorganic layer and π-stacked benzene organic layer in spatial separation, delivering a high reversible capacity and first coulombic efficiency. The experiment and calculation results reveal that the Na-O inorganic layer provides both Na+ ion transport pathway and storage site, whereas the benzene organic layer provides electron transport pathway and redox center. Our contribution provides a brand-new insight in understanding the storage mechanism in inorganic-organic layered host and opens up a new exciting direction for designing new materials for secondary batteries. PMID:26601260

  2. Unraveling Markov Processes in Movement Patterns of Indicator Species in Response to Chemical Stressors

    NASA Astrophysics Data System (ADS)

    Nguyen, Tuyen Van; Liu, Yuedan; Jung, Il-Hyo; Chon, Tae-Soo; Lee, Sang-Hee

    Revealing biological responses of organisms in responding to environmental stressors is the critical issue in contemporary ecological sciences. Markov processes in behavioral data were unraveled by utilizing the hidden Markov model (HMM). Individual organisms of daphnia (Daphnia magna) and zebrafish (Danio rerio) were exposed to diazinon at low concentrations. The transition probability matrix (TPM) and the emission probability matrix (EPM) were accordingly estimated by training with the HMM and were verified before and after the treatments with 10-6 tolerance in 103 iterations. Structured property in behavioral changes was accordingly revealed to characterize dynamic processes in movement patterns. Parameters and sequences produced through the HMM training could be a suitable means of monitoring toxic chemicals in environment.

  3. Unraveling the Mechanism of Nanoscale Mechanical Reinforcement in Glassy Polymer Nanocomposites

    DOE PAGESBeta

    Cheng, Shiwang; Bocharova, Vera; Belianinov, Alex; Xiong, Shaomin; Kisliuk, Alexander; Somnath, Suhas; Holt, Adam P.; Ovchinnikova, Olga S.; Jesse, Stephen; Martin, Halie J.; et al

    2016-05-20

    The mechanical reinforcement of polymer nanocomposites (PNCs) above the glass transition temperature, Tg, has been extensively researched. However, not much is known about the origin of this effect below Tg. In this paper, we unravel the mechanism of PNC reinforcement within the glassy state by directly probing nanoscale mechanical properties with atomic force microscopy and macroscopic properties with Brillouin light scattering. Our results unambiguously show that the "glassy" Young's modulus in the interfacial polymer layer of PNCs is two-times higher than in the bulk polymer, which results in significant reinforcement below Tg. We ascribe this phenomenon to a high stretchingmore » of the chains within the interfacial layer. Since the interfacial chain packing is essentially temperature independent, these findings provide a new insight into the mechanical reinforcement of PNCs also above Tg.« less

  4. Unraveling Photoinduced Spin Dynamics in the Topological Insulator Bi(2)Se(3).

    PubMed

    Wang, M C; Qiao, S; Jiang, Z; Luo, S N; Qi, J

    2016-01-22

    We report on a time-resolved ultrafast optical spectroscopy study of the topological insulator Bi_{2}Se_{3}. We unravel that a net spin polarization cannot only be generated using circularly polarized light via interband transitions between topological surface states (SSs), but also via transitions between SSs and bulk states. Our experiment demonstrates that tuning photon energy or temperature can essentially allow for photoexcitation of spin-polarized electrons to unoccupied topological SSs with two distinct spin relaxation times (∼25 and ∼300  fs), depending on the coupling between SSs and bulk states. The intrinsic mechanism leading to such distinctive spin dynamics is the scattering in SSs and bulk states which is dominated by E_{g}^{2} and A_{1g}^{1} phonon modes, respectively. These findings are suggestive of novel ways to manipulate the photoinduced coherent spins in topological insulators. PMID:26849605

  5. Unraveling chaotic attractors by complex networks and measurements of stock market complexity

    SciTech Connect

    Cao, Hongduo; Li, Ying

    2014-03-15

    We present a novel method for measuring the complexity of a time series by unraveling a chaotic attractor modeled on complex networks. The complexity index R, which can potentially be exploited for prediction, has a similar meaning to the Kolmogorov complexity (calculated from the Lempel–Ziv complexity), and is an appropriate measure of a series' complexity. The proposed method is used to research the complexity of the world's major capital markets. None of these markets are completely random, and they have different degrees of complexity, both over the entire length of their time series and at a level of detail. However, developing markets differ significantly from mature markets. Specifically, the complexity of mature stock markets is stronger and more stable over time, whereas developing markets exhibit relatively low and unstable complexity over certain time periods, implying a stronger long-term price memory process.

  6. Unravelling the nature of non-specific effects of vaccines-A challenge for innate immunologists.

    PubMed

    Jensen, Kristoffer Jarlov; Benn, Christine Stabell; van Crevel, Reinout

    2016-08-01

    Epidemiological observations have shown that vaccines can influence morbidity and mortality more than can be ascribed to target-disease immunity. A growing number of immunological studies have helped identify possible biological mechanisms to explain these so-called nonspecific effects (NSE) of vaccines, including heterologous T-cell reactivity and innate immune memory or 'trained innate immunity', which involves epigenetic reprogramming of innate immune cells. Here, we review the epidemiological evidence for NSE as well as human, animal and in vitro immunological data that could explain these NSE, and discuss priorities for future epidemiologic and immunologic studies to further unravel the biology and optimize the benefits of current and new vaccines. PMID:27354354

  7. Unraveling the Mechanism of Nanoscale Mechanical Reinforcement in Glassy Polymer Nanocomposites

    SciTech Connect

    Cheng, Shiwang; Bocharova, Vera; Belianinov, Alex; Xiong, Shaomin; Kisliuk, Alexander; Somnath, Suhas; Holt, Adam P; Ovchinnikova, Olga S; Jesse, Stephen; Martin, Halie J; Etampawala, Thusitha N; Dadmun, Mark D; Sokolov, Alexei P

    2016-01-01

    The mechanical reinforcement of polymer nanocomposites (PNCs) above the glass transition temperature, Tg, has been extensively studied. However, not much is known about the origin of this effect below Tg. In this Letter, we unravel the mechanism of PNC reinforcement within the glassy state by directly probing nanoscale mechanical properties with atomic force microscopy and macroscopic properties with Brillouin light scattering. Our results unambiguously show that the glassy Young s modulus in the interfacial polymer layer of PNCs is two-times higher than in the bulk polymer, which results in significant reinforcement below Tg. We ascribe this phenomenon to a high stretching of the chains within the interfacial layer. Since the interfacial chain packing is essentially temperature independent, these findings provide a new insight into the mechanical reinforcement of PNCs also above Tg.

  8. Unraveling the complexity of mitochondrial complex I assembly: A dynamic process.

    PubMed

    Sánchez-Caballero, Laura; Guerrero-Castillo, Sergio; Nijtmans, Leo

    2016-07-01

    Mammalian complex I is composed of 44 different subunits and its assembly requires at least 13 specific assembly factors. Proper function of the mitochondrial respiratory chain enzyme is of crucial importance for cell survival due to its major participation in energy production and cell signaling. Complex I assembly depends on the coordination of several crucial processes that need to be tightly interconnected and orchestrated by a number of assembly factors. The understanding of complex I assembly evolved from simple sequential concept to the more sophisticated modular assembly model describing a convoluted process. According to this model, the different modules assemble independently and associate afterwards with each other to form the final enzyme. In this review, we aim to unravel the complexity of complex I assembly and provide the latest insights in this fundamental and fascinating process. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt. PMID:27040506

  9. Unraveling the Mechanism of Nanoscale Mechanical Reinforcement in Glassy Polymer Nanocomposites.

    PubMed

    Cheng, Shiwang; Bocharova, Vera; Belianinov, Alex; Xiong, Shaomin; Kisliuk, Alexander; Somnath, Suhas; Holt, Adam P; Ovchinnikova, Olga S; Jesse, Stephen; Martin, Halie; Etampawala, Thusitha; Dadmun, Mark; Sokolov, Alexei P

    2016-06-01

    The mechanical reinforcement of polymer nanocomposites (PNCs) above the glass transition temperature, Tg, has been extensively studied. However, not much is known about the origin of this effect below Tg. In this Letter, we unravel the mechanism of PNC reinforcement within the glassy state by directly probing nanoscale mechanical properties with atomic force microscopy and macroscopic properties with Brillouin light scattering. Our results unambiguously show that the "glassy" Young's modulus in the interfacial polymer layer of PNCs is two-times higher than in the bulk polymer, which results in significant reinforcement below Tg. We ascribe this phenomenon to a high stretching of the chains within the interfacial layer. Since the interfacial chain packing is essentially temperature independent, these findings provide a new insight into the mechanical reinforcement of PNCs also above Tg. PMID:27203453

  10. Unravelling a 'miner's myth' that environmental contamination in mining towns is naturally occurring.

    PubMed

    Kristensen, Louise Jane; Taylor, Mark Patrick

    2016-08-01

    Australia has a long history of metal mining and smelting. Extraction and processing have resulted in elevated levels of toxic metals surrounding mining operations, which have adverse health effects, particularly to children. Resource companies, government agencies and employees often construct 'myths' to down play potential exposure risks and responsibility arising from operating emissions. Typical statements include: contaminants are naturally occurring, the wind blows emissions away from residential areas, contaminants are not bioavailable, or the problem is a legacy issue and not related to current operations. Evidence from mining and smelting towns shows that such 'myths' are exactly that. In mining towns, the default and primary defence against contamination is that elevated metals in adjacent urban environments are from the erosion and weathering of the ore bodies over millennia-hence 'naturally occurring'. Not only is this a difficult argument to unravel from an evidence-based perspective, but also it causes confusion and delays remediation work, hindering efforts to reduce harmful exposures to children. An example of this situation is from Broken Hill, New South Wales, home to one of the world's largest lead-zinc-silver ore body, which has been mined continuously for over 130 years. Environmental metal concentration and lead isotopic data from soil samples collected from across Broken Hill are used to establish the nature and timing of lead contamination. We use multiple lines of evidence to unravel a 'miner's myth' by evaluating current soil metal concentrations and lead isotopic compositions, geological data, historical environmental assessments and old photographic evidence to assess the impacts from early smelting along with mining to the surface soils in the city. PMID:26919836

  11. Comparison of slurry versus fixed-bed reactor costs for indirect liquefaction applications. A supplement to final report: Design of slurry reactor for indirect liquefaction applications

    SciTech Connect

    Prakash, A.; Bendale, P.G.

    1991-12-01

    This work is a comparative evaluation of slurry reactors and fixed-bed reactors, with special emphasis on cost. Relative differences between slurry reactors and fixed-bed reactors have been pointed out in previous reviews; the differences pertinent to indirect liquefaction are summarized here. Design of both types is outlined.

  12. A Theory-based Comparison of the Reliabilities of Fixed-length and Trials-to-criterion Scoring of Physical Education Skills Tests.

    ERIC Educational Resources Information Center

    Feldt, Leonard S.

    This paper considers, from a theoretical point of view, two measurement approaches used in measuring success and failure in skills tests in physical education. The first, "fixed length" (FL) testing, entails counting the number of successful performances in a fixed number of trials. The second, "trials-to-criterion" (TTC) testing, involves…

  13. Impaired Inhibitory Force Feedback in Fixed Dystonia.

    PubMed

    Mugge, Winfred; Schouten, Alfred C; van Hilten, Jacobus J; van der Helm, Frans C T

    2016-04-01

    Complex regional pain syndrome (CRPS) is a multifactorial disorder associated with an aberrant host response to tissue injury. About 25% of CRPS patients suffer poorly understood involuntary sustained muscle contractions associated with dysfunctional reflexes that result in abnormal postures (fixed dystonia). A recent modeling study simulated fixed dystonia (FD) caused by aberrant force feedback. The current study aims to validate this hypothesis by experimentally recording the modulation of reflexive force feedback in patients with FD. CRPS patients with and without FD, patients with FD but without CRPS, as well as healthy controls participated in the experiment. Three task instructions and three perturbation characteristics were used to evoke a wide range of responses to force perturbations. During position tasks ("maintain posture"), healthy subjects as well as patients resisted the perturbations, becoming more stiff than when being relaxed (i.e., the relax task). Healthy subjects and CRPS patients without FD were both more compliant during force tasks ("maintain force") than during relax tasks, meaning they actively gave way to the imposed forces. Remarkably, the patients with FD failed to do so. A neuromuscular model was fitted to the experimental data to separate the distinct contributions of position, velocity and force feedback, as well as co-contraction to the motor behavior. The neuromuscular modeling indicated that inhibitory force feedback is deregulated in patients with FD, for both CRPS and non-CRPS patients. From previously published simulation results and the present experimental study, it is concluded that aberrant force feedback plays a role in fixed dystonia. PMID:25955788

  14. Temporal correlations imaging fixed targets through turbulence.

    PubMed

    Gulich, Damián

    2016-06-15

    We study the temporal correlations from dynamic imaging through turbulence using incoherent light from fixed high-contrast targets. We conduct our experiment in controlled laboratory conditions using several values of the Cn2 constant from the weak to strong fluctuation regime. We employ detrended fluctuation analysis to measure long-range correlations while considering scintillation information for every recorded pixel. We find that turbulence strength generally increases temporal correlations in time series from pixels in high-contrast regions of the image. PMID:27304306

  15. Fixed Target Beauty Physics Experimental Programs

    SciTech Connect

    Garbincius, P.H.

    1987-11-01

    The current and near term future fixed target physics efforts in observing particles with open beauty are reviewed. This includes a compilation of the non-observation upper limits and the observation of both upsilon and b-states. A short discussion of the theoretical predictions for the hadro-produced beauty pairs is included. The major part of this review is devoted to the techniques and tricks employed, a survey of the current and proposed experiments. A personal summary of the experimental prospects concludes this report. 28 refs., 26 figs.

  16. Improvements in the realization of the ITS-90 over the temperature range from the melting point of gallium to the freezing point of silver at NIM

    SciTech Connect

    Sun, J.; Zhang, J. T.; Ping, Q.

    2013-09-11

    The temperature primary standard over the range from the melting point of gallium to the freezing point of silver in National institute of Metrology (NIM), China, was established in the early 1990s. The performance of all of fixed-point furnaces degraded and needs to be updated due to many years of use. Nowadays, the satisfactory fixed point materials can be available with the development of the modern purification techniques. NIM plans to use a group of three cells for each defining fixed point temperature. In this way the eventual drift of individual cells can be evidenced by periodic intercomparison and this will increase the reliability in disseminating the ITS-90 in China. This article describes the recent improvements in realization of ITS-90 over temperature range from the melting point of gallium to the freezing point of silver at NIM. Taking advantages of the technological advances in the design and manufacture of furnaces, the new three-zone furnaces and the open-type fixed points were developed from the freezing point of indium to the freezing point of silver, and a furnace with the three-zone semiconductor cooling was designed to automatically realize the melting point of gallium. The reproducibility of the new melting point of gallium and the new open-type freezing points of In, Sn, Zn. Al and Ag is improved, especially the freezing points of Al and Ag with the reproducibility of 0.2mK and 0.5mK respectively. The expanded uncertainty in the realization of these defining fixed point temperatures is 0.34mK, 0.44mK, 0.54mK, 0.60mK, 1.30mK and 1.88mK respectively.

  17. 47 CFR 22.1031 - Temporary fixed stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MOBILE SERVICES Offshore Radiotelephone Service § 22.1031 Temporary fixed stations. The FCC may, upon proper application therefor, authorize the construction and operation of temporary fixed stations in...

  18. 47 CFR 22.1031 - Temporary fixed stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MOBILE SERVICES Offshore Radiotelephone Service § 22.1031 Temporary fixed stations. The FCC may, upon proper application therefor, authorize the construction and operation of temporary fixed stations in...

  19. 48 CFR 31.102 - Fixed-price contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Applicability 31.102 Fixed-price contracts... fixed-price contract clause requires the determination or negotiation of costs. However, application...

  20. Ash level meter for a fixed-bed coal gasifier

    DOEpatents

    Fasching, George E.

    1984-01-01

    An ash level meter for a fixed-bed coal gasifier is provided which utilizes the known ash level temperature profile to monitor the ash bed level. A bed stirrer which travels up and down through the extent of the bed ash level is modified by installing thermocouples to measure the bed temperature as the stirrer travels through the stirring cycle. The temperature measurement signals are transmitted to an electronic signal process system by an FM/FM telemetry system. The processing system uses the temperature signals together with an analog stirrer position signal, taken from a position transducer disposed to measure the stirrer position to compute the vertical location of the ash zone upper boundary. The circuit determines the fraction of each total stirrer cycle time the stirrer-derived bed temperature is below a selected set point, multiplies this fraction by the average stirrer signal level, multiplies this result by an appropriate constant and adds another constant such that a 1 to 5 volt signal from the processor corresponds to a 0 to 30 inch span of the ash upper boundary level. Three individual counters in the processor store clock counts that are representative of: (1) the time the stirrer temperature is below the set point (500.degree. F.), (2) the time duration of the corresponding stirrer travel cycle, and (3) the corresponding average stirrer vertical position. The inputs to all three counters are disconnected during any period that the stirrer is stopped, eliminating corruption of the measurement by stirrer stoppage.

  1. Non-Gimbaled Antenna Pointing

    NASA Technical Reports Server (NTRS)

    Vigil, Jeannine S.

    1997-01-01

    The small satellite community has been interested in accessing fixed ground stations for means of space-to-ground transmissions, although a problem arises from the limited global coverage. There is a growing interest for using the Space Network (SN) or Tracking and Data Relay Satellites (TDRS) as the primary support for communications because of the coverage it provides. This thesis will address the potential for satellite access of the Space Network with a non-gimbaled antenna configuration and low-power, coded transmission. The non-gimbaled antenna and the TDRS satellites, TDRS-East, TDRS-West, and TDRS-Zone of Exclusion, were configured in an orbital analysis software package called Satellite Tool Kit to emulate the three-dimensional position of the satellites. The access potential, which is the average number of contacts per day and the average time per contact, were obtained through simulations run over a 30-day period to gain all the possible orientations. The orbital altitude was varied from 600 km through 1200 km with the results being a function of orbital inclination angles varying from 20 deg through 100 deg and pointing half-angles of I0 deg through 40 deg. To compare the validity of the simulations, Jet Propulsion Laboratory granted the use of the TOPEX satellite. The TOPEX satellite was configured to emulate a spin-stabilized antenna with its communications antenna stowed in the zenith-pointing direction. This mimicked the antenna pointing spin-stabilized satellite in the simulations. To make valid comparisons, the TOPEX orbital parameters were entered into Satellite Tool Kit and simulated over five test times provided by Jet Propulsion Laboratory.

  2. Point-to-Point Multicast Communications Protocol

    NASA Technical Reports Server (NTRS)

    Byrd, Gregory T.; Nakano, Russell; Delagi, Bruce A.

    1987-01-01

    This paper describes a protocol to support point-to-point interprocessor communications with multicast. Dynamic, cut-through routing with local flow control is used to provide a high-throughput, low-latency communications path between processors. In addition multicast transmissions are available, in which copies of a packet are sent to multiple destinations using common resources as much as possible. Special packet terminators and selective buffering are introduced to avoid a deadlock during multicasts. A simulated implementation of the protocol is also described.

  3. Fixed film phosphorus removal--flexible enough?

    PubMed

    Rogalla, F; Johnson, T L; McQuarrie, J

    2006-01-01

    While biological phosphorus removal (BPR) has been practised for 30 years, up to recently it has been restricted mainly to activated sludge processes, with the corresponding need for large basin volumes. Yet, research with biofilm reactors showed that the principle of alternate anaerobic and aerated conditions was applicable to fixed bacteria by changing the conditions in time rather than in space. Attached growth enhanced biological phosphorus removal (EBPR) systems are attractive because of their compactness and capability to retain high biomass levels. However, the phosphorus extraction depends on backwashes to enhance the phosphorus-rich attached biomass, and correct control of unsteady effluent quality created by frequently modified process conditions. Accordingly, EBPR remains a challenging task in terms of combining nitrogen and phosphorus removal using attached growth systems. Nevertheless, a combination of activated sludge and biofilm carriers, in the integrated fixed-film activated sludge system, provides treatment opportunities not readily available using suspended growth systems. Current practice is only at the beginning of exploiting the full potential of this combination, but the first full-scale results show that compact tankage and low nutrient results based on biological principles are possible. PMID:16889243

  4. Fixed Drug Eruption due to Achiote Dye

    PubMed Central

    Tattersall, Ian; Reddy, Bobby Y.

    2016-01-01

    Fixed drug eruption (FDE) is a localized type IV sensitivity reaction to a systemically introduced allergen. It usually occurs as a result of new medication, making identification and avoidance of the trigger medication straightforward; however, in a rare subset of cases no pharmacological source is identified. In such cases, the causative agent is often a food or food additive. In this report we describe a case of a FDE in a 12-year-old girl recently immigrated to the United States from Ecuador who had no medication exposure over the course of her illness. Through an exhaustive patient history and literature review, we were able to hypothesize that her presentation was caused by a dietary change of the natural achiote dye used in the preparation of yellow rice to a locally available commercial dye mix containing tartrazine, or Yellow 5, which has previously been implicated in both systemic hypersensitivity reactions and specifically in FDE. This report adds to the small body of available literature on non-pharmacological fixed hypersensitivity eruptions and illustrates an effective approach to the management of such a presentation when history is not immediately revealing. PMID:26933409

  5. Fixed Drug Eruption due to Achiote Dye.

    PubMed

    Tattersall, Ian; Reddy, Bobby Y

    2016-01-01

    Fixed drug eruption (FDE) is a localized type IV sensitivity reaction to a systemically introduced allergen. It usually occurs as a result of new medication, making identification and avoidance of the trigger medication straightforward; however, in a rare subset of cases no pharmacological source is identified. In such cases, the causative agent is often a food or food additive. In this report we describe a case of a FDE in a 12-year-old girl recently immigrated to the United States from Ecuador who had no medication exposure over the course of her illness. Through an exhaustive patient history and literature review, we were able to hypothesize that her presentation was caused by a dietary change of the natural achiote dye used in the preparation of yellow rice to a locally available commercial dye mix containing tartrazine, or Yellow 5, which has previously been implicated in both systemic hypersensitivity reactions and specifically in FDE. This report adds to the small body of available literature on non-pharmacological fixed hypersensitivity eruptions and illustrates an effective approach to the management of such a presentation when history is not immediately revealing. PMID:26933409

  6. Regulatory requirements for marketing fixed dose combinations

    PubMed Central

    Jayasheel, B. G.

    2010-01-01

    The development of fixed-dose combinations (FDCs) is becoming increasingly important from a public health perspective. FDCs have advantages when there is an identifiable patient population for whom treatment with a particular combination of actives in a fixed ratio is safe and effective and when all of the actives contribute to the overall therapeutic effect. Such combinations of drugs are particularly useful in the management of chronic diseases. In addition, there can be real clinical benefits in the form of increased efficacy and/or a reduced incidence of adverse effects. Additional advantages of FDCs are potentially lower costs of manufacturing compared to the costs of producing separate products administered concurrently, simpler logistics of distribution and reduced development of resistance in the case of antimicrobials. Above all, FDC therapy reduces pill burden and improves medication compliance. Although, FDCs seem to be ideal under certain pre-defined circumstances, if a dosing adjustment is warranted, there may not be an FDC available in the most appropriate strength for the patient and if an adverse drug reaction occurs from using an FDC, it may be difficult to identify the active ingredient responsible for causing the reaction. Appendix VI of Schedule Y (Drugs & Cosmetics Rules 1945, India) states the requirements for marketing approval of various types of FDCs. The same is further elaborated in this article to provide a detailed guidance including the clinical trial requirements. However, the heterogeneity of the therapeutic field makes it difficult to develop a standard guidance document. PMID:21350725

  7. Fixed-dose combination therapy for psoriasis.

    PubMed

    Guenther, Lyn C

    2004-01-01

    Fixed-dose combination therapy offers stable products containing two or more medications with different mechanisms of action and safety profiles. It is also convenient for patients since only one product rather than two or more needs to be applied. Topical corticosteroids are often the mainstay of therapy in psoriasis. Diprosalic and Nerisalic contain a topical corticosteroid (betamethasone dipropionate and diflucortolone, respectively) and salicylic acid. A left/right study showed that both products have comparable efficacy. It has also been shown that betamethasone dipropionate + salicylic acid ointment has similar efficacy to clobetasol and calcipotriene (calcipotriol) ointments. Betamethasone dipropionate + salicylic acid lotion has similar efficacy to clobetasol lotion. Faster improvement of scaling, itching, and redness was noted with betamethasone dipropionate + salicylic acid lotion compared with betamethasone dipropionate alone. Dovobet (Daivobet) ointment is a fixed-dose combination product containing betamethasone dipropionate and calcipotriene. Clinical studies have shown that it has greater efficacy and a faster speed of onset than the individual components or tacalcitol. Once daily and twice daily treatments have similar efficacy. Psoriasis Area and Severity Index reductions of approximately 40% after 1 week and 70% after 4 weeks of therapy were consistently noted in six large international studies involving >6000 patients. Betamethasone dipropionate + calcipotriene treatment is associated with approximately 75% less adverse cutaneous events as compared with tacalcitol, 50% less compared with calcipotriene, and a similar number as treatment with betamethasone dipropionate. PMID:15109271

  8. [Fiber-reinforced composite in fixed prosthodontics].

    PubMed

    Pilo, R; Abu Rass, Z; Shmidt, A

    2010-07-01

    Fiber reinforced composite (FRC) is composed of resin matrix and fibers filler. Common types of fibers: polyethylene, carbon and glass. Fibers can be continuous and aligned, discontinuous and aligned, discontinuous and randomly oriented. The architecture of the fibers is unidirectional, woven or braided. The two main types are: dry fibers or impregnated. Inclusion of fibers to resin composite increased its average flexural strength in 100-200 MPa. FRC can be utilized by the dentist in direct approach (splinting, temporary winged bridge) or indirect approach (laboratory made fixed partial denture). Laboratory fixed partial denture (FPD) is made from FRC substructure and Hybrid/Microfill particulate composite veneer. Main indications: interim temporary FPD or FPD in cases of questionable abutment teeth, in aesthetic cases where All Ceram FPD is not feasible. Retention is attained by adhesive cementation to minimally prepared teeth or to conventionally prepared teeth; other options are inlay-onlay bridges or hybrid bridges. Contraindications are: poor hygiene, inability to control humidity, parafunction habits, and more than two pontics. Survival rate of FRC FPD over 5 years is 75%, lower compared to porcelain fused to metal FPD which is 95%. Main reasons for failure are: fracture of framework and delamination of the veneer. Part of the failures is repairable. PMID:21485555

  9. Experimental Study on Nonlinear Vibrations of Fixed-Fixed Curved Beams

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay; Patel, B. P.

    2016-07-01

    Nonlinear dynamic behavior of fixed-fixed shallow and deep curved beams is studied experimentally using non-contact type of electromagnetic shaker and acceleration measurements. The frequency response obtained from acceleration measurements is found to be in fairly good agreement with the computational response. The travellingwave phenomenon along with participation of higher harmonics and softening nonlinearity are observed. The experimental results on the internal resonance of curved beams due to direct excitation of anti-symmetric mode are reported for the first time. The deep curved beam depicts chaotic response at higher excitation amplitude.

  10. FixO3 : Early progress towards Open Ocean observatory Data Management Harmonisation

    NASA Astrophysics Data System (ADS)

    Pagnani, Maureen; Huber, Robert; Lampitt, Richard

    2014-05-01

    . The data management efforts are central to FixO3. Combined with the procedural and technological harmonisation, tackled in separate work packages, the FixO3 network of observatories will efficiently and cost effectively provide a consistent resource of quality controlled accessible oceanographic data The project website www.fixo3.eu is being developed as both a data showcase and single distribution point, and with database driven tools will enable the sharing of information between the observatories in the most smart and cost effective way. The network of knowledge built throughout the project will become a legacy resource that will ensure access to the unique ensemble data sets only achievable at these key observatories.

  11. 46 CFR 130.320 - Electronic position-fixing device.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Electronic position-fixing device. 130.320 Section 130... CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Navigational Equipment § 130.320 Electronic position-fixing device. Each vessel must be equipped with an electronic position-fixing device satisfactory...

  12. 46 CFR 130.320 - Electronic position-fixing device.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Electronic position-fixing device. 130.320 Section 130... CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Navigational Equipment § 130.320 Electronic position-fixing device. Each vessel must be equipped with an electronic position-fixing device satisfactory...

  13. 46 CFR 130.320 - Electronic position-fixing device.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Electronic position-fixing device. 130.320 Section 130... CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Navigational Equipment § 130.320 Electronic position-fixing device. Each vessel must be equipped with an electronic position-fixing device satisfactory...

  14. 49 CFR 587.18 - Dimensions of fixed rigid barrier.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Dimensions of fixed rigid barrier. 587.18 Section 587.18 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... Deformable Barrier § 587.18 Dimensions of fixed rigid barrier. (a) The fixed rigid barrier has a mass of...

  15. 49 CFR 587.18 - Dimensions of fixed rigid barrier.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Dimensions of fixed rigid barrier. 587.18 Section 587.18 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... Deformable Barrier § 587.18 Dimensions of fixed rigid barrier. (a) The fixed rigid barrier has a mass of...

  16. 29 CFR 1910.24 - Fixed industrial stairs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Fixed industrial stairs. 1910.24 Section 1910.24 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.24 Fixed industrial stairs. (a... fixed general industrial stairs. This classification includes interior and exterior stairs...

  17. 29 CFR 1910.24 - Fixed industrial stairs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Fixed industrial stairs. 1910.24 Section 1910.24 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.24 Fixed industrial stairs. (a... fixed general industrial stairs. This classification includes interior and exterior stairs...

  18. 29 CFR 1910.24 - Fixed industrial stairs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Fixed industrial stairs. 1910.24 Section 1910.24 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.24 Fixed industrial stairs. (a... fixed general industrial stairs. This classification includes interior and exterior stairs...

  19. 29 CFR 1910.24 - Fixed industrial stairs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Fixed industrial stairs. 1910.24 Section 1910.24 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.24 Fixed industrial stairs. (a... fixed general industrial stairs. This classification includes interior and exterior stairs...

  20. 29 CFR 1910.24 - Fixed industrial stairs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Fixed industrial stairs. 1910.24 Section 1910.24 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.24 Fixed industrial stairs. (a... fixed general industrial stairs. This classification includes interior and exterior stairs...

  1. 46 CFR 121.410 - Electronic position fixing devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Electronic position fixing devices. 121.410 Section 121... AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 121.410 Electronic position fixing devices. A vessel on an oceans route must be equipped with an electronic position fixing device,...

  2. 46 CFR 121.410 - Electronic position fixing devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Electronic position fixing devices. 121.410 Section 121... AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 121.410 Electronic position fixing devices. A vessel on an oceans route must be equipped with an electronic position fixing device,...

  3. 46 CFR 130.320 - Electronic position-fixing device.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Electronic position-fixing device. 130.320 Section 130... CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Navigational Equipment § 130.320 Electronic position-fixing device. Each vessel must be equipped with an electronic position-fixing device satisfactory...

  4. 46 CFR 130.320 - Electronic position-fixing device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Electronic position-fixing device. 130.320 Section 130... CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Navigational Equipment § 130.320 Electronic position-fixing device. Each vessel must be equipped with an electronic position-fixing device satisfactory...

  5. 47 CFR 25.277 - Temporary fixed earth station operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Temporary fixed earth station operations. 25... SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.277 Temporary fixed earth station operations. (a) When an earth station in the Fixed-Satellite Service is to remain at a single location for...

  6. 47 CFR 25.277 - Temporary fixed earth station operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Temporary fixed earth station operations. 25... SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.277 Temporary fixed earth station operations. (a) When an earth station in the Fixed-Satellite Service is to remain at a single location for...

  7. 47 CFR 25.277 - Temporary fixed earth station operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Temporary fixed earth station operations. 25... SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.277 Temporary fixed earth station operations. (a) When an earth station in the Fixed-Satellite Service is to remain at a single location for...

  8. 33 CFR 118.65 - Lights on fixed bridges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  9. 33 CFR 118.65 - Lights on fixed bridges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  10. 33 CFR 118.65 - Lights on fixed bridges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  11. 33 CFR 118.65 - Lights on fixed bridges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  12. 33 CFR 118.65 - Lights on fixed bridges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  13. 48 CFR 46.304 - Fixed-price service contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Fixed-price service... CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 46.304 Fixed-price service contracts. The contracting officer shall insert the clause at 52.246-4, Inspection of Services—Fixed-Price, in...

  14. 48 CFR 1852.216-83 - Fixed price incentive.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Fixed price incentive... 1852.216-83 Fixed price incentive. As prescribed in 1816.406-70(c), insert the following clause: Fixed Price Incentive (OCT 1996) The target cost of this contract is $___. The Target profit of this...

  15. 48 CFR 1828.370 - Fixed-price contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Fixed-price contract... ADMINISTRATION GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 1828.370 Fixed-price contract... Risk, in all negotiated fixed-price contracts for the development, production,...

  16. 48 CFR 47.104-2 - Fixed-price contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Fixed-price contracts. 47... MANAGEMENT TRANSPORTATION General 47.104-2 Fixed-price contracts. (a) F.o.b. destination. 49 U.S.C. 10721 and 13712 rates do not apply to shipments under fixed-price f.o.b. destination contracts (delivered...

  17. 48 CFR 1816.202 - Firm-fixed-price contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Firm-fixed-price contracts... ADMINISTRATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Fixed-Price Contracts 1816.202 Firm-fixed-price contracts....

  18. 48 CFR 1828.370 - Fixed-price contract clauses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Fixed-price contract... ADMINISTRATION GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 1828.370 Fixed-price contract... Risk, in all negotiated fixed-price contracts for the development, production,...

  19. 48 CFR 31.102 - Fixed-price contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Fixed-price contracts. 31... CONTRACTING REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Applicability 31.102 Fixed-price contracts. The applicable subparts of part 31 shall be used in the pricing of fixed-price contracts,...

  20. 48 CFR 46.302 - Fixed-price supply contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Fixed-price supply... CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 46.302 Fixed-price supply contracts. The contracting officer shall insert the clause at 52.246-2, Inspection of Supplies—Fixed-Price, in solicitations...

  1. 48 CFR 46.304 - Fixed-price service contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Fixed-price service... CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 46.304 Fixed-price service contracts. The contracting officer shall insert the clause at 52.246-4, Inspection of Services—Fixed-Price, in...

  2. 48 CFR 47.104-2 - Fixed-price contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Fixed-price contracts. 47... MANAGEMENT TRANSPORTATION General 47.104-2 Fixed-price contracts. (a) F.o.b. destination. 49 U.S.C. 10721 and 13712 rates do not apply to shipments under fixed-price f.o.b. destination contracts (delivered...

  3. 48 CFR 52.243-1 - Changes-Fixed-Price.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Changes-Fixed-Price. 52....243-1 Changes—Fixed-Price. As prescribed in 43.205(e), insert the following clause: Changes—Fixed-Price (AUG 1987) (a) The Contracting Officer may at any time, by written order, and without notice...

  4. 48 CFR 1816.202 - Firm-fixed-price contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Firm-fixed-price contracts... ADMINISTRATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Fixed-Price Contracts 1816.202 Firm-fixed-price contracts....

  5. 48 CFR 52.243-1 - Changes-Fixed-Price.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Changes-Fixed-Price. 52....243-1 Changes—Fixed-Price. As prescribed in 43.205(e), insert the following clause: Changes—Fixed-Price (AUG 1987) (a) The Contracting Officer may at any time, by written order, and without notice...

  6. 48 CFR 52.243-1 - Changes-Fixed-Price.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false Changes-Fixed-Price. 52....243-1 Changes—Fixed-Price. As prescribed in 43.205(e), insert the following clause: Changes—Fixed-Price (AUG 1987) (a) The Contracting Officer may at any time, by written order, and without notice...

  7. 48 CFR 46.302 - Fixed-price supply contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Fixed-price supply... CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 46.302 Fixed-price supply contracts. The contracting officer shall insert the clause at 52.246-2, Inspection of Supplies—Fixed-Price, in solicitations...

  8. 48 CFR 52.243-1 - Changes-Fixed-Price.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false Changes-Fixed-Price. 52....243-1 Changes—Fixed-Price. As prescribed in 43.205(e), insert the following clause: Changes—Fixed-Price (AUG 1987) (a) The Contracting Officer may at any time, by written order, and without notice...

  9. 48 CFR 31.102 - Fixed-price contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Fixed-price contracts. 31... CONTRACTING REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Applicability 31.102 Fixed-price contracts. The applicable subparts of part 31 shall be used in the pricing of fixed-price contracts,...

  10. 50 CFR 660.219 - Fixed gear identification and marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Fixed gear identification and marking. 660.219 Section 660.219 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Groundfish-Limited Entry Fixed Gear Fisheries § 660.219 Fixed gear identification and marking. (a)...

  11. 29 CFR 1910.161 - Fixed extinguishing systems, dry chemical.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Fixed extinguishing systems, dry chemical. 1910.161 Section... § 1910.161 Fixed extinguishing systems, dry chemical. (a) Scope and application. This section applies to all fixed extinguishing systems, using dry chemical as the extinguishing agent, installed to meet...

  12. 29 CFR 1910.161 - Fixed extinguishing systems, dry chemical.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Fixed extinguishing systems, dry chemical. 1910.161 Section... § 1910.161 Fixed extinguishing systems, dry chemical. (a) Scope and application. This section applies to all fixed extinguishing systems, using dry chemical as the extinguishing agent, installed to meet...

  13. 29 CFR 1910.161 - Fixed extinguishing systems, dry chemical.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Fixed extinguishing systems, dry chemical. 1910.161 Section... § 1910.161 Fixed extinguishing systems, dry chemical. (a) Scope and application. This section applies to all fixed extinguishing systems, using dry chemical as the extinguishing agent, installed to meet...

  14. 29 CFR 1910.161 - Fixed extinguishing systems, dry chemical.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Fixed extinguishing systems, dry chemical. 1910.161 Section... § 1910.161 Fixed extinguishing systems, dry chemical. (a) Scope and application. This section applies to all fixed extinguishing systems, using dry chemical as the extinguishing agent, installed to meet...

  15. Charm and beauty measurements at Fermilab fixed target

    SciTech Connect

    Mishra, C.S.

    1993-10-01

    Eighteen months after a successful run of the Fermilab fixed target program, interesting results from several experiments are available. This is the first time that more than one Fermilab fixed target experiment has reported the observation of beauty mesons. In this paper we review recent results from charm and beauty fixed target experiments at Fermilab.

  16. 10 CFR 600.29 - Fixed obligation awards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Fixed obligation awards. 600.29 Section 600.29 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS FINANCIAL ASSISTANCE RULES General § 600.29 Fixed obligation awards. (a) General. This section contains provisions applicable to the award of financial assistance instruments on a fixed amount...

  17. 47 CFR 101.125 - Temporary fixed antenna height restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Temporary fixed antenna height restrictions... SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.125 Temporary fixed antenna height restrictions. The overall antenna structure heights employed by mobile stations in the...

  18. 47 CFR 101.125 - Temporary fixed antenna height restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Temporary fixed antenna height restrictions... SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.125 Temporary fixed antenna height restrictions. The overall antenna structure heights employed by mobile stations in the...

  19. 47 CFR 101.125 - Temporary fixed antenna height restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Temporary fixed antenna height restrictions... SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.125 Temporary fixed antenna height restrictions. The overall antenna structure heights employed by mobile stations in the...

  20. 47 CFR 101.125 - Temporary fixed antenna height restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Temporary fixed antenna height restrictions... SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.125 Temporary fixed antenna height restrictions. The overall antenna structure heights employed by mobile stations in the...

  1. 47 CFR 101.125 - Temporary fixed antenna height restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Temporary fixed antenna height restrictions... SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.125 Temporary fixed antenna height restrictions. The overall antenna structure heights employed by mobile stations in the...

  2. 48 CFR 1852.216-83 - Fixed price incentive.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Fixed price incentive. 1852... 1852.216-83 Fixed price incentive. As prescribed in 1816.406-70(c), insert the following clause: Fixed Price Incentive (OCT 1996) The target cost of this contract is $___. The Target profit of this...

  3. 47 CFR 15.307 - Coordination with fixed microwave service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Coordination with fixed microwave service. 15... Unlicensed Personal Communications Service Devices § 15.307 Coordination with fixed microwave service. (a... Private Operational-Fixed Microwave Service (OFS) operating under part 101 of this chapter to...

  4. 47 CFR 15.307 - Coordination with fixed microwave service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Coordination with fixed microwave service. 15... Unlicensed Personal Communications Service Devices § 15.307 Coordination with fixed microwave service. (a... Private Operational-Fixed Microwave Service (OFS) operating under part 101 of this chapter to...

  5. 47 CFR 25.277 - Temporary fixed earth station operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Temporary fixed earth station operations. 25... SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.277 Temporary fixed earth station operations. (a) When an earth station in the Fixed-Satellite Service is to remain at a single location for...

  6. 47 CFR 25.277 - Temporary fixed earth station operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Temporary fixed earth station operations. 25... SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.277 Temporary fixed earth station operations. (a) When an earth station in the Fixed-Satellite Service is to remain at a single location for...

  7. 46 CFR 108.631 - Fixed fire extinguishing system controls.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.631 Fixed fire extinguishing system controls. (a) Each cabinet or space that contains a valve, control, or manifold of a fixed fire... 46 Shipping 4 2011-10-01 2011-10-01 false Fixed fire extinguishing system controls....

  8. 46 CFR 108.631 - Fixed fire extinguishing system controls.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.631 Fixed fire extinguishing system controls. (a) Each cabinet or space that contains a valve, control, or manifold of a fixed fire... 46 Shipping 4 2010-10-01 2010-10-01 false Fixed fire extinguishing system controls....

  9. Point by Point: Adding up Motivation

    ERIC Educational Resources Information Center

    Marchionda, Denise

    2010-01-01

    Students often view their course grades as a mysterious equation of teacher-given grades, teacher-given grace, and some other ethereal components based on luck. However, giving students the power to earn points based on numerous daily/weekly assignments and attendance makes the grading process objective and personal, freeing the instructor to…

  10. Splitting the Cartesian point

    SciTech Connect

    Blodwell, J.F.

    1987-10-01

    It is argued that the point structure of space and time must be constructed from the primitive extensional character of space and time. A procedure for doing this is laid down and applied to one-dimensional and two-dimensional systems of abstract extensions. Topological and metrical properties of the constructed point systems, which differ nontrivially from the usual R and R/sup 2/ models, are examined. Briefly, constructed points are associated with directions and the Cartesian point is split. In one-dimension each point splits into a point pair compatible with the linear ordering. An application to one-dimensional particle motion is given, with the result that natural topological assumptions force the number of left point, right point transitions to remain locally finite in a continuous motion. In general, Cartesian points are seen to correspond to certain filters on a suitable Boolean algebra. Constructed points correspond to ultrafilters. Thus, point construction gives a natural refinement of the Cartesian systems.

  11. Solar sail surfing along families of equilibrium points

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel

    2008-07-01

    We have considered the planar circular RTBP + solar radiation pressure to model the movement of a solar sail in the Earth-Sun system. It is known that for a fixed value of the sail lightness number this model has three 1-parametric families of equilibria parametrised by the sail orientation. Most of these fixed points are unstable and require a control strategy to keep a sail close to them. We have studied the linear dynamic around them and how it varies when the sail orientation is changed. We have used this information to derive strategies to move along these families and control the trajectory of the sail close to a given fixed point. Finally, we have tested our strategies for a particular mission.

  12. Using Technology to Unify Geometric Theorems about the Power of a Point

    ERIC Educational Resources Information Center

    Contreras, Jose N.

    2011-01-01

    In this article, I describe a classroom investigation in which a group of prospective secondary mathematics teachers discovered theorems related to the power of a point using "The Geometer's Sketchpad" (GSP). The power of a point is defines as follows: Let "P" be a fixed point coplanar with a circle. If line "PA" is a secant line that intersects…

  13. Thermal conductivity at a disordered quantum critical point

    NASA Astrophysics Data System (ADS)

    Hartnoll, Sean A.; Ramirez, David M.; Santos, Jorge E.

    2016-04-01

    Strongly disordered and strongly interacting quantum critical points are difficult to access with conventional field theoretic methods. They are, however, both experimentally important and theoretically interesting. In particular, they are expected to realize universal incoherent transport. Such disordered quantum critical theories have recently been constructed holographically by deforming a CFT by marginally relevant disorder. In this paper we find additional disordered fixed points via relevant disordered deformations of a holographic CFT. Using recently developed methods in holographic transport, we characterize the thermal conductivity in both sets of theories in 1+1 dimensions. The thermal conductivity is found to tend to a constant at low temperatures in one class of fixed points, and to scale as T 0.3 in the other. Furthermore, in all cases the thermal conductivity exhibits discrete scale invariance, with logarithmic in temperature oscillations superimposed on the low temperature scaling behavior. At no point do we use the replica trick.

  14. Fixed target experiments at the Fermilab Tevatron

    DOE PAGESBeta

    Gutierrez, Gaston; Reyes, Marco A.

    2014-11-10

    This paper presents a review of the study of Exclusive Central Production at a Center of Mass energy of √s = 40 GeV at the Fermilab Fixed Target program. In all reactions reviewed in this paper, protons with an energy of 800 GeV were extracted from the Tevatron accelerator at Fermilab and directed to a Liquid Hydrogen target. The states reviewed include π⁺π⁻, K⁰s K⁰s, K⁰s K±π∓, φφ and D*±. Partial Wave Analysis results will be presented on the light states but only the cross-section will be reviewed in the diffractive production of D*±.

  15. Quality of fixed prosthodontics after 15 years.

    PubMed

    Glantz, P O; Nilner, K; Jendresen, M D; Sundberg, H

    1993-08-01

    Interviews and/or clinical examinations by means of the California Dental Association quality evaluation system were carried out in a group of persons who had received extensive restorative treatments with fixed partial dentures 15 years before this study. The studied group consisted of 77 persons who agreed to participate from an original group of 150 persons selected at random from the Swedish Dental Insurance System records. Of the original group 20 had died, 17 were not traceable or not able to participate for medical reasons, and 36 declined to participate. Thirty-two per cent of the recorded reconstructions had been lost, and 8% partially lost during the 15-year period. Thirty-five per cent of the reconstructions were rated as Satisfactory, whereas the remaining ones had mixed clinical quality ratings. Failures and Not Acceptable quality ratings were found to be caused mainly by fractures, loss of retention, and/or dental caries. PMID:8237309

  16. Fixed drug eruption due to levocetirizine.

    PubMed

    Jhaj, Ratinder; Asati, Dinesh Prasad; Chaudhary, Deepa

    2016-01-01

    A fixed drug eruption (FDE) is a cutaneous adverse drug reaction due to Type IV or delayed cell-mediated hypersensitivity. Antihistamines, which antagonize the action of histamine during an allergic reaction by blocking the H1 histamine receptors, are used routinely for the treatment of various allergic disorders such as urticaria, eczemas, and also in itchy lesions of skin like scabies. Levocetirizine, an active (R)-enantiomer of cetirizine, is a newer or second generation antihistamine, with more specific actions and fewer side effects, including cutaneous reactions. FDE due to levocetirizine as well as with cetirizine are rare. We report a case of levocetirizine induced FDE in a 49-year-old male patient with scabies. The patient had a history of cetirizine induced FDE in the past. PMID:27440959

  17. Ursodeoxycholic acid induced generalized fixed drug eruption.

    PubMed

    Ozkol, Hatice Uce; Calka, Omer; Dulger, Ahmet Cumhur; Bulut, Gulay

    2014-09-01

    Fixed drug eruption (FDE) is a rare form of drug allergies that recur at the same cutaneous or mucosal site in every usage of drug. Single or multiple round, sharply demarcated and dusky red plaques appear soon after drug exposure. Ursodeoxycholic acid (UDCA: 3α,7β-dihydroxy-5β-cholanic acid) is used for the treatment of cholestatic liver diseases. Some side effects may be observed, such as diarrhea, dyspepsia, pruritus and headaches. We encountered only three cases of lichenoid reaction regarding the use of UDCA among previous studies. In this article, we reported a generalized FDE case related to UDCA intake in a 59-year-old male patient with cholestasis for the first time in the literature. PMID:24147950

  18. Fixed target experiments at the Fermilab Tevatron

    SciTech Connect

    Gutierrez, Gaston; Reyes, Marco A.

    2014-11-10

    This paper presents a review of the study of Exclusive Central Production at a Center of Mass energy of √s = 40 GeV at the Fermilab Fixed Target program. In all reactions reviewed in this paper, protons with an energy of 800 GeV were extracted from the Tevatron accelerator at Fermilab and directed to a Liquid Hydrogen target. The states reviewed include π⁺π⁻, K⁰s K⁰s, K⁰s K±π, φφ and D. Partial Wave Analysis results will be presented on the light states but only the cross-section will be reviewed in the diffractive production of D.

  19. Fixed-target hadron production experiments

    NASA Astrophysics Data System (ADS)

    Popov, Boris A.

    2015-08-01

    Results from fixed-target hadroproduction experiments (HARP, MIPP, NA49 and NA61/SHINE) as well as their implications for cosmic ray and neutrino physics are reviewed. HARP measurements have been used for predictions of neutrino beams in K2K and MiniBooNE/SciBooNE experiments and are also being used to improve predictions of the muon yields in EAS and of the atmospheric neutrino fluxes as well as to help in the optimization of neutrino factory and super-beam designs. Recent measurements released by the NA61/SHINE experiment are of significant importance for a precise prediction of the J-PARC neutrino beam used for the T2K experiment and for interpretation of EAS data. These hadroproduction experiments provide also a large amount of input for validation and tuning of hadron production models in Monte-Carlo generators.

  20. Fixed drug eruption due to levocetirizine

    PubMed Central

    Jhaj, Ratinder; Asati, Dinesh Prasad; Chaudhary, Deepa

    2016-01-01

    A fixed drug eruption (FDE) is a cutaneous adverse drug reaction due to Type IV or delayed cell-mediated hypersensitivity. Antihistamines, which antagonize the action of histamine during an allergic reaction by blocking the H1 histamine receptors, are used routinely for the treatment of various allergic disorders such as urticaria, eczemas, and also in itchy lesions of skin like scabies. Levocetirizine, an active (R)-enantiomer of cetirizine, is a newer or second generation antihistamine, with more specific actions and fewer side effects, including cutaneous reactions. FDE due to levocetirizine as well as with cetirizine are rare. We report a case of levocetirizine induced FDE in a 49-year-old male patient with scabies. The patient had a history of cetirizine induced FDE in the past. PMID:27440959

  1. Fixed Eigenvector Analysis of Thermographic NDE Data

    NASA Technical Reports Server (NTRS)

    Cramer, K. Elliott; Winfree, William P.

    2011-01-01

    Principal Component Analysis (PCA) has been shown effective for reducing thermographic NDE data. This paper will discuss an alternative method of analysis that has been developed where a predetermined set of eigenvectors is used to process the thermal data from both reinforced carbon-carbon (RCC) and graphiteepoxy honeycomb materials. These eigenvectors can be generated either from an analytic model of the thermal response of the material system under examination, or from a large set of experimental data. This paper provides the details of the analytic model, an overview of the PCA process, as well as a quantitative signal-to-noise comparison of the results of performing both conventional PCA and fixed eigenvector analysis on thermographic data from two specimens, one Reinforced Carbon-Carbon with flat bottom holes and the second a sandwich construction with graphite-epoxy face sheets and aluminum honeycomb core.

  2. Meprobamate-induced fixed drug eruption.

    PubMed

    Zaïem, Ahmed; Kaabi, Widd; Badri, Talel; Lakhoua, Ghozlane; Sahnoun, Rym; Kastalli, Sarrah; Daghfous, Riadh; Lakhal, Mohamed; El Aidli, Sihem

    2014-01-01

    Meprobamate is usually a safe drug prescribed for anxiety disorders. Fixed drug eruption (FDE) is an exceptional cutaneous adverse effect of this drug. We report a case of FDE induced by meprobamate with positive patch test. A 22-year-old woman was prescribed for depression meprobamate, aceprometazine, valpromide and lorazepam. On the second day of treatment, the patient presented red erythematous and pruriginous plaques in the limbs and the face. After stopping the previous treatment, the patient's lesions resolved completely within 3 weeks with residual pigmentation. One month later, patch tests were performed and were positive to meprobamate. Exceptional cases of FDE were reported in literature with meprobamate. None has reported the use of patch test to confirm the diagnosis. PMID:24446836

  3. Link and subgraph likelihoods in random undirected networks with fixed and partially fixed degree sequences

    NASA Astrophysics Data System (ADS)

    Foster, Jacob G.; Foster, David V.; Grassberger, Peter; Paczuski, Maya

    2007-10-01

    The simplest null models for networks, used to distinguish significant features of a particular network from a priori expected features, are random ensembles with the degree sequence fixed by the specific network of interest. These “fixed degree sequence” (FDS) ensembles are, however, famously resistant to analytic attack. In this paper we introduce ensembles with partially-fixed degree sequences (PFDS) and compare analytic results obtained for them with Monte Carlo results for the FDS ensemble. These results include link likelihoods, subgraph likelihoods, and degree correlations. We find that local structural features in the FDS ensemble can be reasonably well estimated by simultaneously fixing only the degrees of a few nodes, in addition to the total number of nodes and links. As test cases we use two protein interaction networks (Escherichia coli, Saccharomyces cerevisiae), the internet on the autonomous system (AS) level, and the World Wide Web. Fixing just the degrees of two nodes gives the mean neighbor degree as a function of node degree, ⟨k'⟩k , in agreement with results explicitly obtained from rewiring. For power law degree distributions, we derive the disassortativity analytically. In the PFDS ensemble the partition function can be expanded diagrammatically. We obtain an explicit expression for the link likelihood to lowest order, which reduces in the limit of large, sparse undirected networks with L links and with kmax≪L to the simple formula P(k,k')=kk'/(2L+kk') . In a similar limit, the probability for three nodes to be linked into a triangle reduces to the factorized expression PΔ(k1,k2,k3)=P(k1,k2)P(k1,k3)P(k2,k3) .

  4. Do foliar endophytic bacteria fix nitrogen?

    NASA Astrophysics Data System (ADS)

    Kueppers, L. M.; Moyes, A. B.; Frank, C.; Pett-Ridge, J.; Carper, D.; Vandehey, N.; O'Neil, J.; Dekas, A.

    2015-12-01

    Endophytic microorganisms - bacteria and fungi that live inside healthy plant tissue - are a relatively unexplored source of functional diversity in natural ecosystems. Prior to modern sequencing technology, detecting uncultured endophytic bacteria and assessing their putative functions was challenging. However, recent work has revealed a remarkable diversity of as yet non-culturable endophytic taxa and is beginning to identify functional roles within plant microbiomes. We recently examined bacterial communities in the foliage of a long-lived, high-elevation conifer species, limber pine (Pinus flexilis), and discovered a community strongly dominated by acetic acid bacteria (Acetobacteraceae), with several taxa closely related to known nitrogen fixers. Given limber pine's status as a pioneer species that is able to grow in low fertility soils, we hypothesized that this bacterial community has a potential functional role in fixing atmospheric nitrogen, providing a source of this limiting nutrient to the host tree. We used the radioisotope 13N2 to confirm that N2 rapidly diffuses into pine needles, where it could potentially be fixed. With an acetylene reduction assay we confirmed nitrogenase enzyme activity inside excised twigs 4 times over a growing season, and estimate potential rates of N2 fixation at 0.1 nmol N2 g needle-1 hr-1. Scaled to the stand level, this N input could be on the order of ~20 mg N m-2 d-1 over a growing season. While these rates are low, the long lifespan of individual trees (~1000 years) makes them biologically meaningful. Still, measured rates of acetylene reduction and bulk 15N2 incorporation are quite variable in space and time. Much work remains to better characterize the plant-microbial interactions in this system, including the rates of nitrogen fixation and their variability over the growing season, across edaphic conditions, among host species, and through plant development; and to determine which community members are responsible

  5. Magnetic monopoles and Abelian gauge fixing in SU(4) gauge group

    NASA Astrophysics Data System (ADS)

    Rafibakhsh, Shahnoosh; Eshraghi, Mojtaba; Kahnemuii, Mohammad Javad

    2016-01-01

    Abelian gauge fixing procedure is used to create the SU (4) magnetic monopoles in the vicinity of the points where the gluon field becomes singular. The matrix of the scalar field is considered as almost diagonal in the SU (2) and SU (3) subspaces. The gauge transformation which diagonalizes the hedgehog filed, transforms the gluon field into two regular and singular parts. The abelian magnetic monopoles which appear in the latter part obey the quantization condition.

  6. Scattering of point source illumination by an arbitrary configuration

    NASA Technical Reports Server (NTRS)

    Solakiewicz, Richard

    1994-01-01

    The problem of electromagnetic scattering of an incident plane wave by an arbitrary configuration of obstacles was solved by Twersky. In this report, the results are extended to point source incidence corresponding to a Hertz dipole. Knowledge of the response of a fixed configuration of scatterers excited by a point source may provide insight to improve the accuracy of the values of bulk parameters for clouds which have been found using plane wave excitation.

  7. 47 CFR 80.477 - AMTS points of communication.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....477 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Public Coast Stations Automated Systems § 80.477 AMTS points of... frequencies on a secondary basis for fixed service communications to support offshore AMTS operations....

  8. 47 CFR 80.477 - AMTS points of communication.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....477 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Public Coast Stations Automated Systems § 80.477 AMTS points of... frequencies on a secondary basis for fixed service communications to support offshore AMTS operations....

  9. 47 CFR 80.477 - AMTS points of communication.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....477 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Public Coast Stations Automated Systems § 80.477 AMTS points of... frequencies on a secondary basis for fixed service communications to support offshore AMTS operations....

  10. 47 CFR 80.477 - AMTS points of communication.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....477 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Public Coast Stations Automated Systems § 80.477 AMTS points of... frequencies on a secondary basis for fixed service communications to support offshore AMTS operations....

  11. The influence of some relevant metallic impurities in the triple point of mercury temperature

    NASA Astrophysics Data System (ADS)

    Tabacaru, C.; del Campo, D.; Gómez, E.; García Izquiedo, C.; Welna, A.; Kalemci, M.; Pehlivan, Ö.

    2016-02-01

    The influence of impurities on the defined fixed points of the International Temperature Scale of 1990 is one of the most relevant sources of uncertainty in their use. Namely, the triple point of mercury is one of the fixed points most used because its assigned triple point temperature (-39,8344 °C) is within a temperature range of high interest for science and industry. Mercury can be obtained with high purity, usually better that 8N and it is realized with a high accuracy, what makes impurities a significant contributor on the final uncertainty. The best procedure to quantify this influence is by means of doping experiments which consist of the addition of a controlled amount of an impurity, determined gravimetrically, in a fixed point cell. This paper presents a summary of the results obtained from a series of doping experiments performed with some relevant metallic impurities on the triple point of mercury temperature.

  12. Set point calculations for RAPID project

    SciTech Connect

    HICKMAN, G.L.

    1999-11-19

    This change modifies accuracies of the water skid temperature indicators and controllers TIC-410. TI-412, TI-413, TIC-413, TIC-414, TIC-415. Acknowledges ability to calibrate PQIT-367 and modifies the accuracy of that instrument loop. Adjusts the allowable dilution dater temperature from 110-130F to 102-130F based on PCP Rev.2 and adjusts alarm and other points to reflect that change. Removes revision numbers for all references. Numerous additional changes (fixing typos, more detailed explanations etc.) throughout.

  13. Maxwell's conjecture on three point charges with equal magnitudes

    NASA Astrophysics Data System (ADS)

    Tsai, Ya-Lun

    2015-08-01

    Maxwell's conjecture on three point charges states that the number of non-degenerate equilibrium points of the electrostatic field generated by them in R3 is at most four. We prove the conjecture in the cases when three point charges have equal magnitudes and show the number of isolated equilibrium points can only be zero, two, three, or four. Specifically, fixing positions of two positive charges in R3, we know exactly where to place the third positive charge to have two, three, or four equilibrium points. All equilibrium points are isolated and there are no other possibilities for the number of isolated equilibrium points. On the other hand, if both two of the fixed charges have negative charge values, there are always two equilibrium points except when the third positive charge lies in the line segment connecting the two negative charges. The exception cases are when the field contains only a curve of equilibrium points. In this paper, computations assisted by computer involve symbolic and exact integer computations. Therefore, all the results are proved rigorously.

  14. Unravelling merging behaviors and electrostatic properties of CVD-grown monolayer MoS2 domains.

    PubMed

    Hao, Song; Yang, Bingchu; Gao, Yongli

    2016-08-28

    The presence of grain boundaries is inevitable for chemical vapor deposition (CVD)-grown MoS2 domains owing to various merging behaviors, which greatly limits its potential applications in novel electronic and optoelectronic devices. It is therefore of great significance to unravel the merging behaviors of the synthesized polygon shape MoS2 domains. Here we provide systematic investigations of merging behaviors and electrostatic properties of CVD-grown polycrystalline MoS2 crystals by multiple means. Morphological results exhibit various polygon shape features, ascribed to polycrystalline crystals merged with triangle shape MoS2 single crystals. The thickness of triangle and polygon shape MoS2 crystals is identical manifested by Raman intensity and peak position mappings. Three merging behaviors are proposed to illustrate the formation mechanisms of observed various polygon shaped MoS2 crystals. The combined photoemission electron microscopy and kelvin probe force microscopy results reveal that the surface potential of perfect merged crystals is identical, which has an important implication for fabricating MoS2-based devices. PMID:27586938

  15. Unraveling the aggregation effect on amorphous phase AIE luminogens: a computational study.

    PubMed

    Zheng, Xiaoyan; Peng, Qian; Zhu, Lizhe; Xie, Yujun; Huang, Xuhui; Shuai, Zhigang

    2016-08-18

    To achieve the efficient and precise regulation of aggregation-induced emission (AIE), unraveling the aggregation effects on amorphous AIE luminogens is of vital importance. Using a theoretical protocol combining molecular dynamics simulations and quantum mechanics/molecular mechanics calculations, we explored the relationship between molecular packing, optical spectra and fluorescence quantum efficiency of amorphous AIE luminogens hexaphenylsilole (HPS). We confirmed that the redshifted emission of amorphous aggregates as compared to crystalline HPS is caused by the lower packing density of amorphous HPS aggregates and the reduced restrictions on their intramolecular low-frequency vibrational motions. Strikingly, our calculations revealed the size independent fluorescence quantum efficiency of nanosized HPS aggregates and predicted the linear relationship between the fluorescence intensity and aggregate size. This is because the nanosized aggregates are dominated by embedded HPS molecules which exhibit similar fluorescence quantum efficiency at different aggregate sizes. In addition, our results provided a direct explanation for the crystallization-enhanced emission phenomenon of propeller-shaped AIE luminogens in experiments. Our theoretical protocol is general and applicable to other AIE luminogens, thus laying solid foundation for the rational design of advanced AIE materials. PMID:27417250

  16. Systems-based approaches to unravel multi-species microbial community functioning

    PubMed Central

    Abram, Florence

    2014-01-01

    Some of the most transformative discoveries promising to enable the resolution of this century's grand societal challenges will most likely arise from environmental science and particularly environmental microbiology and biotechnology. Understanding how microbes interact in situ, and how microbial communities respond to environmental changes remains an enormous challenge for science. Systems biology offers a powerful experimental strategy to tackle the exciting task of deciphering microbial interactions. In this framework, entire microbial communities are considered as metaorganisms and each level of biological information (DNA, RNA, proteins and metabolites) is investigated along with in situ environmental characteristics. In this way, systems biology can help unravel the interactions between the different parts of an ecosystem ultimately responsible for its emergent properties. Indeed each level of biological information provides a different level of characterisation of the microbial communities. Metagenomics, metatranscriptomics, metaproteomics, metabolomics and SIP-omics can be employed to investigate collectively microbial community structure, potential, function, activity and interactions. Omics approaches are enabled by high-throughput 21st century technologies and this review will discuss how their implementation has revolutionised our understanding of microbial communities. PMID:25750697

  17. How can EPR spectroscopy help to unravel molecular mechanisms of flavin-dependent photoreceptors?

    PubMed Central

    Nohr, Daniel; Rodriguez, Ryan; Weber, Stefan; Schleicher, Erik

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy is a well-established spectroscopic method for the examination of paramagnetic molecules. Proteins can contain paramagnetic moieties in form of stable cofactors, transiently formed intermediates, or spin labels artificially introduced to cysteine sites. The focus of this review is to evaluate potential scopes of application of EPR to the emerging field of optogenetics. The main objective for EPR spectroscopy in this context is to unravel the complex mechanisms of light-active proteins, from their primary photoreaction to downstream signal transduction. An overview of recent results from the family of flavin-containing, blue-light dependent photoreceptors is given. In detail, mechanistic similarities and differences are condensed from the three classes of flavoproteins, the cryptochromes, LOV (Light-oxygen-voltage), and BLUF (blue-light using FAD) domains. Additionally, a concept that includes spin-labeled proteins and examination using modern pulsed EPR is introduced, which allows for a precise mapping of light-induced conformational changes. PMID:26389123

  18. Unravelling the geometry of data matrices: effects of water stress regimes on winemaking.

    PubMed

    Fushing, Hsieh; Hsueh, Chih-Hsin; Heitkamp, Constantin; Matthews, Mark A; Koehl, Patrice

    2015-10-01

    A new method is proposed for unravelling the patterns between a set of experiments and the features that characterize those experiments. The aims are to extract these patterns in the form of a coupling between the rows and columns of the corresponding data matrix and to use this geometry as a support for model testing. These aims are reached through two key steps, namely application of an iterative geometric approach to couple the metric spaces associated with the rows and columns, and use of statistical physics to generate matrices that mimic the original data while maintaining their inherent structure, thereby providing the basis for hypothesis testing and statistical inference. The power of this new method is illustrated on the study of the impact of water stress conditions on the attributes of 'Cabernet Sauvignon' Grapes, Juice, Wine and Bottled Wine from two vintages. The first step, named data mechanics, de-convolutes the intrinsic effects of grape berries and wine attributes due to the experimental irrigation conditions from the extrinsic effects of the environment. The second step provides an analysis of the associations of some attributes of the bottled wine with characteristics of either the matured grape berries or the resulting juice, thereby identifying statistically significant associations between the juice pH, yeast assimilable nitrogen, and sugar content and the bottled wine alcohol level. PMID:26468072

  19. Unraveling the Role of Monovalent Halides in Mixed-Halide Organic-Inorganic Perovskites.

    PubMed

    Deepa, Melepurath; Ramos, F Javier; Shivaprasad, S M; Ahmad, Shahzada

    2016-03-16

    The performance of perovskite solar cells is strongly influenced by the composition and microstructure of the perovskite. A recent approach to improve the power conversion efficiencies utilized mixed-halide perovskites, but the halide ions and their roles were not directly studied. Unraveling their precise location in the perovskite layer is of paramount importance. Here, we investigated four different perovskites by using X-ray photoelectron spectroscopy, and found that among the three studied mixed-halide perovskites, CH3 NH3 Pb(I0.74 Br0.26 )3 and CH3 NH3 PbBr3-x Clx show peaks that unambiguously demonstrate the presence of iodide and bromide in the former, and bromide and chloride in the latter. The CH3 NH3 PbI3-x Clx perovskite shows anomalous behavior, the iodide content far outweighs that of the chloride; a small proportion of chloride, in all likelihood, resides deep within the TiO2 /absorber layer. Our study reveals that there are many distinguishable structural differences between these perovskites, and that these directly impact the photovoltaic performances. PMID:26717046

  20. Unravelling the impact of ethnicity on health in Europe: the HELIUS study

    PubMed Central

    2013-01-01

    Background Populations in Europe are becoming increasingly ethnically diverse, and health risks differ between ethnic groups. The aim of the HELIUS (HEalthy LIfe in an Urban Setting) study is to unravel the mechanisms underlying the impact of ethnicity on communicable and non-communicable diseases. Methods/design HELIUS is a large-scale prospective cohort study being carried out in Amsterdam, the Netherlands. The sample is made up of Amsterdam residents of Surinamese (with Afro-Caribbean Surinamese and South Asian-Surinamese as the main ethnic groups), Turkish, Moroccan, Ghanaian, and ethnic Dutch origin. HELIUS focuses on three disease categories: cardiovascular disease (including diabetes), mental health (depressive disorders and substance use disorders), and infectious diseases. The explanatory mechanisms being studied include genetic profile, culture, migration history, ethnic identity, socio-economic factors and discrimination. These might affect disease risks through specific risk factors including health-related behaviour and living and working conditions. Every five years, participants complete a standardized questionnaire and undergo a medical examination. Biological samples are obtained for diagnostic tests and storage. Participants’ data are linked to morbidity and mortality registries. The aim is to recruit a minimum of 5,000 respondents per ethnic group, to a total of 30,000 participants. Discussion This paper describes the rationale, conceptual framework, and design and methods of the HELIUS study. HELIUS will contribute to an understanding of inequalities in health between ethnic groups and the mechanisms that link ethnicity to health in Europe. PMID:23621920

  1. Direct observation of ultrafast-electron-transfer reactions unravels high effectiveness of reductive DNA damage.

    PubMed

    Nguyen, Jenny; Ma, Yuhan; Luo, Ting; Bristow, Robert G; Jaffray, David A; Lu, Qing-Bin

    2011-07-19

    Both water and electron-transfer reactions play important roles in chemistry, physics, biology, and the environment. Oxidative DNA damage is a well-known mechanism, whereas the relative role of reductive DNA damage is unknown. The prehydrated electron (e(pre)-), a novel species of electrons in water, is a fascinating species due to its fundamental importance in chemistry, biology, and the environment. e(pre)- is an ideal agent to observe reductive DNA damage. Here, we report both the first in situ femtosecond time-resolved laser spectroscopy measurements of ultrafast-electron-transfer (UET) reactions of e(pre)- with various scavengers (KNO(3), isopropanol, and dimethyl sulfoxide) and the first gel electrophoresis measurements of DNA strand breaks induced by e(pre)- and OH(•) radicals co-produced by two-UV-photon photolysis of water. We strikingly found that the yield of reductive DNA strand breaks induced by each e(pre)- is twice the yield of oxidative DNA strand breaks induced by each OH(•) radical. Our results not only unravel the long-standing mystery about the relative role of radicals in inducing DNA damage under ionizing radiation, but also challenge the conventional notion that oxidative damage is the main pathway for DNA damage. The results also show the potential of femtomedicine as a new transdisciplinary frontier and the broad significance of UET reactions of e(pre)- in many processes in chemistry, physics, biology, and the environment. PMID:21730183

  2. Novel Techniques and Approaches to Unravel the Nature of X-Ray Absorption Spectra

    SciTech Connect

    Groot, F. M. F. de

    2007-02-02

    This paper discusses the role of resonant inelastic X-ray scattering (RIXS) to unravel the nature of the states that are visible in the pre-edge region of the 3d metal K edges. The traditional pre-edge analysis into quadrupole transitions to the 3d-states plus dipole transitions to the 4p states is outlined, with special attention to the situation of TiO2. The general possibilities of RIXS are described, including the various possible cross-sections through the 2D RIXS plane. Recent developments in High-Energy Resolution Fluorescence Detection (HERFD) are discussed, that yield XANES-like spectra with unprecedented resolution. Using the 1s2p RIXS of LiCoO2 as example, the presence of an extra peak due to non-local dipole transitions is explained. The non-local nature of this dipole pre-edge peak is proven from its behavior in the 2D RIXS plane. The paper also discusses a range of selective X-ray absorption experiments, where the selectivity is towards (a) the spin-state, (b) the valence, (c) the neighbor atom and (d) the edge. In the outlook, a number of additional experimental routes is suggested, which shows that the use of RIXS, HERFD and selective XAS techniques is only just starting.

  3. Exploring the N-glycosylation Pathway in Chlamydomonas reinhardtii Unravels Novel Complex Structures*

    PubMed Central

    Mathieu-Rivet, Elodie; Scholz, Martin; Arias, Carolina; Dardelle, Flavien; Schulze, Stefan; Le Mauff, François; Teo, Gavin; Hochmal, Ana Karina; Blanco-Rivero, Amaya; Loutelier-Bourhis, Corinne; Kiefer-Meyer, Marie-Christine; Fufezan, Christian; Burel, Carole; Lerouge, Patrice; Martinez, Flor; Bardor, Muriel; Hippler, Michael

    2013-01-01

    Chlamydomonas reinhardtii is a green unicellular eukaryotic model organism for studying relevant biological and biotechnological questions. The availability of genomic resources and the growing interest in C. reinhardtii as an emerging cell factory for the industrial production of biopharmaceuticals require an in-depth analysis of protein N-glycosylation in this organism. Accordingly, we used a comprehensive approach including genomic, glycomic, and glycoproteomic techniques to unravel the N-glycosylation pathway of C. reinhardtii. Using mass-spectrometry-based approaches, we found that both endogenous soluble and membrane-bound proteins carry predominantly oligomannosides ranging from Man-2 to Man-5. In addition, minor complex N-linked glycans were identified as being composed of partially 6-O-methylated Man-3 to Man-5 carrying one or two xylose residues. These findings were supported by results from a glycoproteomic approach that led to the identification of 86 glycoproteins. Here, a combination of in-source collision-induced dissodiation (CID) for glycan fragmentation followed by mass tag-triggered CID for peptide sequencing and PNGase F treatment of glycopeptides in the presence of 18O-labeled water in conjunction with CID mass spectrometric analyses were employed. In conclusion, our data support the notion that the biosynthesis and maturation of N-linked glycans in the endoplasmic reticulum and Golgi apparatus occur via a GnT I-independent pathway yielding novel complex N-linked glycans that maturate differently from their counterparts in land plants. PMID:23912651

  4. Unraveling hidden order in the dynamics of developed and emerging markets.

    PubMed

    Berman, Yonatan; Shapira, Yoash; Ben-Jacob, Eshel

    2014-01-01

    The characterization of asset price returns is an important subject in modern finance. Traditionally, the dynamics of stock returns are assumed to lack any temporal order. Here we present an analysis of the autocovariance of stock market indices and unravel temporal order in several major stock markets. We also demonstrate a fundamental difference between developed and emerging markets in the past decade - emerging markets are marked by positive order in contrast to developed markets whose dynamics are marked by weakly negative order. In addition, the reaction to financial crises was found to be reversed among developed and emerging markets, presenting large positive/negative autocovariance spikes following the onset of these crises. Notably, the Chinese market shows neutral or no order while being regarded as an emerging market. These findings show that despite the coupling between international markets and global trading, major differences exist between different markets, and demonstrate that the autocovariance of markets is correlated with their stability, as well as with their state of development. PMID:25383630

  5. Unravelling druggable signalling networks that control F508del-CFTR proteostasis.

    PubMed

    Hegde, Ramanath Narayana; Parashuraman, Seetharaman; Iorio, Francesco; Ciciriello, Fabiana; Capuani, Fabrizio; Carissimo, Annamaria; Carrella, Diego; Belcastro, Vincenzo; Subramanian, Advait; Bounti, Laura; Persico, Maria; Carlile, Graeme; Galietta, Luis; Thomas, David Y; Di Bernardo, Diego; Luini, Alberto

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether 'classical' signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect. PMID:26701908

  6. Unravelling druggable signalling networks that control F508del-CFTR proteostasis

    PubMed Central

    Hegde, Ramanath Narayana; Parashuraman, Seetharaman; Capuani, Fabrizio; Carissimo, Annamaria; Carrella, Diego; Belcastro, Vincenzo; Subramanian, Advait; Bounti, Laura; Persico, Maria; Carlile, Graeme; Galietta, Luis; Thomas, David Y; Di Bernardo, Diego; Luini, Alberto

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether ‘classical’ signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect. DOI: http://dx.doi.org/10.7554/eLife.10365.001 PMID:26701908

  7. Unraveling the Secrets of Bacterial Adhesion Organelles Using Single-Molecule Force Spectroscopy

    NASA Astrophysics Data System (ADS)

    Axner, Ove; Björnham, Oscar; Castelain, Mickaël; Koutris, Efstratios; Schedin, Staffan; Fällman, Erik; Andersson, Magnus

    Many types of bacterium express micrometer-long attachment organelles (so-called pili) whose role is to mediate adhesion to host tissue. Until recently, little was known about their function in the adhesion process. Force-measuring optical tweezers (FMOT) have since then been used to unravel the biomechanical properties of various types of pili, primarily those from uropathogenic E. coli, in particular their force-vs.-elongation response, but lately also some properties of the adhesin are situated at the distal end of the pilus. This knowledge provides an understanding of how piliated bacteria can sustain external shear forces caused by rinsing processes, e.g., urine flow. It has been found that many types of pilus exhibit unique and complex force-vs.-elongation responses. It has been conjectured that their dissimilar properties impose significant differences in their ability to sustain external forces and that different types of pilus therefore have dissimilar predisposition to withstand different types of rinsing conditions. An understanding of these properties is of high importance since it can serve as a basis for finding new means to combat bacterial adhesion, including that caused by antibiotic-resistance bacteria. This work presents a review of the current status of the assessment of biophysical properties of individual pili on single bacteria exposed to strain/stress, primarily by the FMOT technique. It also addresses, for the first time, how the elongation and retraction properties of the rod couple to the adhesive properties of the tip adhesin.

  8. Unraveling Hidden Order in the Dynamics of Developed and Emerging Markets

    PubMed Central

    Berman, Yonatan; Shapira, Yoash; Ben-Jacob, Eshel

    2014-01-01

    The characterization of asset price returns is an important subject in modern finance. Traditionally, the dynamics of stock returns are assumed to lack any temporal order. Here we present an analysis of the autocovariance of stock market indices and unravel temporal order in several major stock markets. We also demonstrate a fundamental difference between developed and emerging markets in the past decade - emerging markets are marked by positive order in contrast to developed markets whose dynamics are marked by weakly negative order. In addition, the reaction to financial crises was found to be reversed among developed and emerging markets, presenting large positive/negative autocovariance spikes following the onset of these crises. Notably, the Chinese market shows neutral or no order while being regarded as an emerging market. These findings show that despite the coupling between international markets and global trading, major differences exist between different markets, and demonstrate that the autocovariance of markets is correlated with their stability, as well as with their state of development. PMID:25383630

  9. Unraveling the Structure of Viral Replication Complexes at Super-Resolution

    PubMed Central

    Linnik, Olga; Liesche, Johannes; Tilsner, Jens; Oparka, Karl J.

    2013-01-01

    During infection, many RNA viruses produce characteristic inclusion bodies that contain both viral and host components. These structures were first described over a century ago and originally termed “X-bodies,” as their function was not immediately appreciated. Whilst some inclusion bodies may represent cytopathic by-products of viral protein over-accumulation, X-bodies have emerged as virus “factories,” quasi-organelles that coordinate diverse viral infection processes such as replication, protein expression, evasion of host defenses, virion assembly, and intercellular transport. Accordingly, they are now generally referred to as viral replication complexes (VRCs). We previously used confocal fluorescence microscopy to unravel the complex structure of X-bodies produced by Potato virus X (PVX). Here we used 3D-structured illumination (3D-SIM) super-resolution microscopy to map the PVX X-body at a finer scale. We identify a previously unrecognized membrane structure induced by the PVX “triple gene block” (TGB) proteins, providing new insights into the complex interplay between virus and host within the X-body. PMID:23386855

  10. Unraveling the structure of viral replication complexes at super-resolution.

    PubMed

    Linnik, Olga; Liesche, Johannes; Tilsner, Jens; Oparka, Karl J

    2013-01-01

    During infection, many RNA viruses produce characteristic inclusion bodies that contain both viral and host components. These structures were first described over a century ago and originally termed "X-bodies," as their function was not immediately appreciated. Whilst some inclusion bodies may represent cytopathic by-products of viral protein over-accumulation, X-bodies have emerged as virus "factories," quasi-organelles that coordinate diverse viral infection processes such as replication, protein expression, evasion of host defenses, virion assembly, and intercellular transport. Accordingly, they are now generally referred to as viral replication complexes (VRCs). We previously used confocal fluorescence microscopy to unravel the complex structure of X-bodies produced by Potato virus X (PVX). Here we used 3D-structured illumination (3D-SIM) super-resolution microscopy to map the PVX X-body at a finer scale. We identify a previously unrecognized membrane structure induced by the PVX "triple gene block" (TGB) proteins, providing new insights into the complex interplay between virus and host within the X-body. PMID:23386855

  11. Unraveling the Interaction of Silver Nanoparticles with Mammalian and Bacterial DNA.

    PubMed

    Pramanik, Srikrishna; Chatterjee, Sabyasachi; Saha, Arindam; Devi, Parukuttyamma Sujatha; Suresh Kumar, Gopinatha

    2016-06-23

    The focus of this study was to understand and unravel the interaction of silver nanoparticles (AgNPs) with different types of Deoxyribonucleic acid (DNA), mammalian and bacterial, having different base pair compositions. Binding of spherical silver nanoparticles (AgNPs) to Calf thymus (CT) DNA, Escherichia coli (EC) DNA and Micrococcus lysodeikticus (ML) DNA has been studied to gain insights into their mode of interaction and specificity. Interaction of AgNPs with synthetic DNA has also been carried out. On the basis of absorption, thermal melting, isothermal calorimetry and viscosity studies, we could establish the mode of binding and specificity of the synthesized silver nanoparticles with mammalian and bacterial DNA. Thermal melting (Tm) studies indicated a decrease in the Tm of all the DNAs, confirming the destabilization of DNA stacks on interaction with AgNPs. Comparative interaction studies with single stranded (ss) and double stranded (ds) DNAs further confirmed the specificity of the particles toward ds DNA. On the basis of the results we could confirm that the synthesized AgNPs could be used for selective detection of DNA through their DNA binding mechanism. In addition, the AgNPs-DNA complexes exhibited distinct differences in the SERS spectra making it an interesting SERS platform for identifying ds DNA. The optical and physical properties of AgNPs help in differentiating the DNAs of different base pair compositions through their binding affinity and specificity. PMID:27294883

  12. Biclustering with Flexible Plaid Models to Unravel Interactions between Biological Processes.

    PubMed

    Henriques, Rui; Madeira, Sara C

    2015-01-01

    Genes can participate in multiple biological processes at a time and thus their expression can be seen as a composition of the contributions from the active processes. Biclustering under a plaid assumption allows the modeling of interactions between transcriptional modules or biclusters (subsets of genes with coherence across subsets of conditions) by assuming an additive composition of contributions in their overlapping areas. Despite the biological interest of plaid models, few biclustering algorithms consider plaid effects and, when they do, they place restrictions on the allowed types and structures of biclusters, and suffer from robustness problems by seizing exact additive matchings. We propose BiP (Biclustering using Plaid models), a biclustering algorithm with relaxations to allow expression levels to change in overlapping areas according to biologically meaningful assumptions (weighted and noise-tolerant composition of contributions). BiP can be used over existing biclustering solutions (seizing their benefits) as it is able to recover excluded areas due to unaccounted plaid effects and detect noisy areas non-explained by a plaid assumption, thus producing an explanatory model of overlapping transcriptional activity. Experiments on synthetic data support BiP's efficiency and effectiveness. The learned models from expression data unravel meaningful and non-trivial functional interactions between biological processes associated with putative regulatory modules. PMID:26357312

  13. A bivariate mann-whitney approach for unraveling genetic variants and interactions contributing to comorbidity.

    PubMed

    Wen, Yalu; Schaid, Daniel J; Lu, Qing

    2013-04-01

    Although comorbidity among complex diseases (e.g., drug dependence syndromes) is well documented, genetic variants contributing to the comorbidity are still largely unknown. The discovery of genetic variants and their interactions contributing to comorbidity will likely shed light on underlying pathophysiological and etiological processes, and promote effective treatments for comorbid conditions. For this reason, studies to discover genetic variants that foster the development of comorbidity represent high-priority research projects, as manifested in the behavioral genetics studies now underway. The yield from these studies can be enhanced by adopting novel statistical approaches, with the capacity of considering multiple genetic variants and possible interactions. For this purpose, we propose a bivariate Mann-Whitney (BMW) approach to unravel genetic variants and interactions contributing to comorbidity, as well as those unique to each comorbid condition. Through simulations, we found BMW outperformed two commonly adopted approaches in a variety of underlying disease and comorbidity models. We further applied BMW to datasets from the Study of Addiction: Genetics and Environment, investigating the contribution of 184 known nicotine dependence (ND) and alcohol dependence (AD) single nucleotide polymorphisms (SNPs) to the comorbidity of ND and AD. The analysis revealed a candidate SNP from CHRNA5, rs16969968, associated with both ND and AD, and replicated the findings in an independent dataset with a P-value of 1.06 × 10(-03) . PMID:23334941

  14. Unraveling Health Risk and Speciation of Arsenic from Groundwater in Rural Areas of Punjab, Pakistan

    PubMed Central

    Shakoor, Muhammad Bilal; Niazi, Nabeel Khan; Bibi, Irshad; Rahman, Mohammad Mahmudur; Naidu, Ravi; Dong, Zhaomin; Shahid, Muhammad; Arshad, Muhammad

    2015-01-01

    This study determined the total and speciated arsenic (As) concentrations and other health-related water quality parameters for unraveling the health risk of As from drinking water to humans. Groundwater samples (n = 62) were collected from three previously unexplored rural areas (Chichawatni, Vehari, Rahim Yar Khan) of Punjab in Pakistan. The mean and median As concentrations in groundwater were 37.9 and 12.7 µg·L−1 (range = 1.5–201 µg·L−1). Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 µg·L−1. Speciation of As in groundwater samples (n = 13) showed the presence of inorganic As only; arsenite (As(III)) constituted 13%–67% of total As and arsenate (As(V)) ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11–18 and 46–600 times higher than the recommended values of US-EPA (i.e., 1.00 and 10−6, respectively). In addition to As, various water quality parameters (e.g., electrical conductivity, Na, Ca, Cl−, NO3−, SO42−, Fe, Mn, Pb) also enhanced the health risk. The results show that consumption of As-contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures. PMID:26445051

  15. Unraveling multiple binding modes of acridine orange to DNA using a multispectroscopic approach.

    PubMed

    Sayed, Mhejabeen; Krishnamurthy, Bhavana; Pal, Haridas

    2016-09-21

    The interaction of acridine orange (AOH(+)) with calf thymus DNA (ct-DNA) under different dye-DNA conditions has been investigated in detail using multispectroscopic techniques, unraveling a number of hitherto unexplored intricacies of dye-DNA binding. The observed results intriguingly show contrasting binding features when low (2.4 μM) and significantly high (23 μM) dye concentrations are used. It is conclusively inferred from absorption, steady-state fluorescence, circular dichroism, fluorescence decay and anisotropy decay studies that at low [DNA] to [dye] ratio, especially with higher dye concentration, dimeric AOH(+) predominantly binds externally to DNA surfaces through electrostatic interactions. At sufficiently high [DNA] to [dye] ratios, however, the interaction intriguingly changes to monomeric AOH(+) bound to DNA, predominantly in the intercalative mode between DNA base pairs, with partly an electrostatic binding on DNA surfaces. With very low initial dye concentration, monomeric (AOH(+)) mostly binds to DNA through intercalative and electrostatic modes for most DNA to dye ratios. The present study demonstrates a systematic correlation of the striking changes in the photophysical properties of the dye upon multimode binding with DNA. The observed results are of great significance in understanding the fundamental insights of dye/drug binding to DNA hosts, of use in the design of effective therapeutic agents. PMID:27545984

  16. On the power and limits of evolutionary conservation—unraveling bacterial gene regulatory networks

    PubMed Central

    Baumbach, Jan

    2010-01-01

    The National Center for Biotechnology Information (NCBI) recently announced ‘1000 prokaryotic genomes are now completed and available in the Genome database’. The increasing trend will provide us with thousands of sequenced microbial organisms over the next years. However, this is only the first step in understanding how cells survive, reproduce and adapt their behavior while being exposed to changing environmental conditions. One major control mechanism is transcriptional gene regulation. Here, striking is the direct juxtaposition of the handful of bacterial model organisms to the 1000 prokaryotic genomes. Next-generation sequencing technologies will further widen this gap drastically. However, several computational approaches have proven to be helpful. The main idea is to use the known transcriptional regulatory network of reference organisms as template in order to unravel evolutionarily conserved gene regulations in newly sequenced species. This transfer essentially depends on the reliable identification of several types of conserved DNA sequences. We decompose this problem into three computational processes, review the state of the art and illustrate future perspectives. PMID:20699275

  17. ODE constrained mixture modelling: a method for unraveling subpopulation structures and dynamics.

    PubMed

    Hasenauer, Jan; Hasenauer, Christine; Hucho, Tim; Theis, Fabian J

    2014-07-01

    Functional cell-to-cell variability is ubiquitous in multicellular organisms as well as bacterial populations. Even genetically identical cells of the same cell type can respond differently to identical stimuli. Methods have been developed to analyse heterogeneous populations, e.g., mixture models and stochastic population models. The available methods are, however, either incapable of simultaneously analysing different experimental conditions or are computationally demanding and difficult to apply. Furthermore, they do not account for biological information available in the literature. To overcome disadvantages of existing methods, we combine mixture models and ordinary differential equation (ODE) models. The ODE models provide a mechanistic description of the underlying processes while mixture models provide an easy way to capture variability. In a simulation study, we show that the class of ODE constrained mixture models can unravel the subpopulation structure and determine the sources of cell-to-cell variability. In addition, the method provides reliable estimates for kinetic rates and subpopulation characteristics. We use ODE constrained mixture modelling to study NGF-induced Erk1/2 phosphorylation in primary sensory neurones, a process relevant in inflammatory and neuropathic pain. We propose a mechanistic pathway model for this process and reconstructed static and dynamical subpopulation characteristics across experimental conditions. We validate the model predictions experimentally, which verifies the capabilities of ODE constrained mixture models. These results illustrate that ODE constrained mixture models can reveal novel mechanistic insights and possess a high sensitivity. PMID:24992156

  18. Unravelling the structure of species extinction risk for predictive conservation science

    PubMed Central

    Lee, Tien Ming; Jetz, Walter

    2011-01-01

    Extinction risk varies across species and space owing to the combined and interactive effects of ecology/life history and geography. For predictive conservation science to be effective, large datasets and integrative models that quantify the relative importance of potential factors and separate rapidly changing from relatively static threat drivers are urgently required. Here, we integrate and map in space the relative and joint effects of key correlates of The International Union for Conservation of Nature-assessed extinction risk for 8700 living birds. Extinction risk varies significantly with species' broad-scale environmental niche, geographical range size, and life-history and ecological traits such as body size, developmental mode, primary diet and foraging height. Even at this broad scale, simple quantifications of past human encroachment across species' ranges emerge as key in predicting extinction risk, supporting the use of land-cover change projections for estimating future threat in an integrative setting. A final joint model explains much of the interspecific variation in extinction risk and provides a remarkably strong prediction of its observed global geography. Our approach unravels the species-level structure underlying geographical gradients in extinction risk and offers a means of disentangling static from changing components of current and future threat. This reconciliation of intrinsic and extrinsic, and of past and future extinction risk factors may offer a critical step towards a more continuous, forward-looking assessment of species' threat status based on geographically explicit environmental change projections, potentially advancing global predictive conservation science. PMID:20943690

  19. Microarray: gateway to unravel the mystery of abiotic stresses in plants.

    PubMed

    Gul, Ambreen; Ahad, Ammara; Akhtar, Sidra; Ahmad, Zarnab; Rashid, Bushra; Husnain, Tayyab

    2016-04-01

    Environmental factors, such as drought, salinity, extreme temperature, ozone poisoning, metal toxicity etc., significantly affect crops. To study these factors and to design a possible remedy, biological experimental data concerning these crops requires the quantification of gene expression and comparative analyses at high throughput level. Development of microarrays is the platform to study the differential expression profiling of the targeted genes. This technology can be applied to gene expression studies, ranging from individual genes to whole genome level. It is now possible to perform the quantification of the differential expression of genes on a glass slide in a single experiment. This review documents recently published reports on the use of microarrays for the identification of genes in different plant species playing their role in different cellular networks under abiotic stresses. The regulation pattern of differentially-expressed genes, individually or in group form, may help us to study different pathways and functions at the cellular and molecular level. These studies can provide us with a lot of useful information to unravel the mystery of abiotic stresses in important crop plants. PMID:26667130

  20. Unravelling the optical responses of nanoplasmonic mirror-on-mirror metamaterials.

    PubMed

    Sikdar, Debabrata; Hasan, Shakeeb B; Urbakh, Michael; Edel, Joshua B; Kornyshev, Alexei A

    2016-07-27

    Mirror-on-mirror platforms based on arrays of metallic nanoparticles, arranged top-down or self-assembled on a thin metallic film, have interesting optical properties. Interaction of localized surface-plasmons in nanoparticles with propagating surface-plasmons in the film underpins the exotic features of such platforms. Here, we present a comprehensive theoretical framework which emulates such a system using a five-layer-stack model and calculate its reflectance, transmittance, and absorbance spectra. The theory rests on dipolar quasi-static approximations incorporating image-forces and effective medium theory. Systematically tested against full-wave simulations, this simple approach proves to be adequate within its obvious applicability limits. It is used to study optical signals as a function of nanoparticle dimensions, interparticle separation, metal film thickness, the gap between the film and nanoparticles, and incident light characteristics. Several peculiar features are found, e.g., quenching of reflectivity in certain frequency domains or shift of the reflectivity spectra. Schemes are proposed to tailor those as functions of the mentioned parameters. Calculating the system's optical responses in seconds, as compared to much longer running simulations, this theory helps to momentarily unravel the role of each system parameter in light reflection, transmission, and absorption, facilitating thereby the design and optimisation of novel mirror-on-mirror systems. PMID:27406066