NMC and the Fine-Tuning Problem on the Brane

Directory of Open Access Journals (Sweden)

A. Safsafi

2014-01-01

Full Text Available We propose a new solution to the fine-tuning problem related to coupling constant λ of the potential. We study a quartic potential of the form λϕ4 in the framework of the Randall-Sundrum type II braneworld model in the presence of a Higgs field which interacts nonminimally with gravity via a possible interaction term of the form -(ξ/2ϕ2R. Using the conformal transformation techniques, the slow-roll parameters in high energy limit are reformulated in the case of a nonminimally coupled scalar field. We show that, for some value of a coupling parameter ξ and brane tension T, we can eliminate the fine-tuning problem. Finally, we present graphically the solutions of several values of the free parameters of the model.

Modern Cosmology and Anthropic Fine-Tuning: Three approaches

Science.gov (United States)

Collins, Robin

The anthropic fine-tuning of the cosmos refers to the claim that the laws of nature, the constants of physics, and the initial conditions of the universe must be set to an enormous degree of precision for embodied conscious agents to exist. Three major responses have been offered to this fine-tuning: the multiverse explanation; theism; and the claim that it is just a brute fact that requires no further explanation. In this chapter, I will consider each explanation in turn, and provide some novel arguments for the superiority of a theistic or related explanation. In the last section, I will show how whether or not one adopts a theistic or related explanation can significantly influence what features of the universe one considers in need of further scientific explanation, and the type of scientific explanation that one should find satisfactory. In particular, I will argue that in some cases atheism, not theism, serves as a science stopper in discouraging a search for deeper scientific explanations of phenomena.

Testing SUSY at the LHC: Electroweak and Dark matter fine tuning at two-loop order

CERN Document Server

Cassel, S; Ross, G G

2010-01-01

In the framework of the Constrained Minimal Supersymmetric Standard Model (CMSSM) we evaluate the electroweak fine tuning measure that provides a quantitative test of supersymmetry as a solution to the hierarchy problem. Taking account of current experimental constraints we compute the fine tuning at two-loop order and determine the limits on the CMSSM parameter space and the measurements at the LHC most relevant in covering it. Without imposing the LEPII bound on the Higgs mass, it is shown that the fine tuning computed at two-loop has a minimum $\\Delta=8.8$ corresponding to a Higgs mass $m_h=114\\pm 2$ GeV. Adding the constraint that the SUSY dark matter relic density should be within present bounds we find $\\Delta=15$ corresponding to $m_h=114.7\\pm 2$ GeV and this rises to $\\Delta=17.8$ ($m_h=115.9\\pm 2$ GeV) for SUSY dark matter abundance within 3$\\sigma$ of the WMAP constraint. We extend the analysis to include the contribution of dark matter fine tuning. In this case the overall fine tuning and Higgs mas...

Scalar sector extensions and the Higgs mass fine-tuning problem

International Nuclear Information System (INIS)

Chakraborty, Indrani

2014-01-01

One of the ways to address the fine-tuning problem in the Standard Model is to assume the existence of some symmetry which keeps the quantum corrections to the Higgs mass to a manageable level. This condition, known after Veltman who first propounded it, is unfortunately not satisfied in the SM, given that we know all the masses. We discuss how one can get back the Veltman Condition if one or more gauge singlet scalars are introduced in the model. We show that the most favored solution is the case where the singlet scalar does not mix with the SM doublet, and thus can act as a viable cold dark matter candidate. Furthermore, the fine-tuning problem of the new scalars necessitates the introduction of vector like fermions. Thus, singlet scalar(s) and vector fermions are minimal enhancements over the Standard Model to alleviate the fine-tuning problem. We also show that the model predicts Landau poles for all the scalar couplings, whose positions depend only on the number of such singlets. Thus, introduction of some new physics at that scale becomes inevitable. We also discuss how the model confronts the LHC constraints and the latest XENON100 data. Some more such extensions, with higher scalar multiplets, are also discussed. (author)

Fine-tuning problem in renormalized perturbation theory: Spontaneously-broken gauge models

Energy Technology Data Exchange (ETDEWEB)

Foda, O.E. (Purdue Univ., Lafayette, IN (USA). Dept. of Physics)

1983-04-28

We study the stability of tree-level gauge hierarchies at higher orders in renormalized perturbation theory, in a model with spontaneously-broken gauge symmetries. We confirm previous results indicating that if the model is renormalized using BPHZ, then the tree-level hierarchy is not upset by the radiative corrections. Consequently, no fine-tuning of the initial parameters is required to maintain it, in contrast to the result obtained using Dimensional Renormalization. This verifies the conclusion that the need for fine-tuning, when it arises, is an artifact of the application of a certain class of renormalization schemes.

RF MEMS suspended band-stop resonator and filter for frequency and bandwidth continuous fine tuning

International Nuclear Information System (INIS)

Jang, Yun-Ho; Kim, Yong-Kweon; Llamas-Garro, Ignacio; Kim, Jung-Mu

2012-01-01

We firstly propose the concept of a frequency and bandwidth fine-tuning method using an RF MEMS-based suspended tunable band-stop resonator. We experimentally show the feasibility of the continuously tuned resonator, including a second-order filter, which consists of cascaded resonators to achieve center frequency and bandwidth fine tuning. The structure consists of a freestanding half-wavelength (λ/2) resonator connected to a large displacement comb actuator. The lateral movement of the λ/2 resonator over the main transmission line produces different electromagnetic decoupling values from the main transmission line. The decoupled energy leads to continuous center frequency and bandwidth tuning using the band-stop resonator circuit for fine-tuning applications. The freestanding λ/2 resonator plays the role of a variable capacitor as well as a decoupling resonator in the proposed structure. The fabricated tunable filter shows suitability for Ku-band wireless communication system applications with continuous reconfiguration

Improving the Fine-Tuning of Metaheuristics: An Approach Combining Design of Experiments and Racing Algorithms

Directory of Open Access Journals (Sweden)

Eduardo Batista de Moraes Barbosa

2017-01-01

Full Text Available Usually, metaheuristic algorithms are adapted to a large set of problems by applying few modifications on parameters for each specific case. However, this flexibility demands a huge effort to correctly tune such parameters. Therefore, the tuning of metaheuristics arises as one of the most important challenges in the context of research of these algorithms. Thus, this paper aims to present a methodology combining Statistical and Artificial Intelligence methods in the fine-tuning of metaheuristics. The key idea is a heuristic method, called Heuristic Oriented Racing Algorithm (HORA, which explores a search space of parameters looking for candidate configurations close to a promising alternative. To confirm the validity of this approach, we present a case study for fine-tuning two distinct metaheuristics: Simulated Annealing (SA and Genetic Algorithm (GA, in order to solve the classical traveling salesman problem. The results are compared considering the same metaheuristics tuned through a racing method. Broadly, the proposed approach proved to be effective in terms of the overall time of the tuning process. Our results reveal that metaheuristics tuned by means of HORA achieve, with much less computational effort, similar results compared to the case when they are tuned by the other fine-tuning approach.

Graphene-based fine-tunable optical delay line for optical beamforming in phased-array antennas.

Science.gov (United States)

Tatoli, Teresa; Conteduca, Donato; Dell'Olio, Francesco; Ciminelli, Caterina; Armenise, Mario N

2016-06-01

The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τg=920  ps) together with a compact footprint (4.15  mm2) and optical loss graphene-based Mach-Zehnder interferometer switches and two vertically stacked microring resonators between which a graphene capacitor is placed. The tuning range is obtained by varying the value of the voltage applied to the graphene electrodes, which controls the optical path of the light propagation and therefore the delay time. The graphene provides a faster reconfigurable time and low values of energy dissipation. Such significant advantages, together with a negligible beam-squint effect, allow us to overcome the limitations of conventional RF beamformers. A highly efficient fine-tunable optical delay line for the beamsteering of 20 radiating elements up to ±20° in the azimuth direction of a tile in a phased-array antenna of an X-band synthetic aperture radar has been designed.

Non-universal gaugino masses and fine tuning implications for SUSY searches in the MSSM and the GNMSSM

CERN Document Server

Kaminska, Anna; Schmidt-Hoberg, Kai

2013-01-01

For the case of the MSSM and the most general form of the NMSSM (GNMSSM) we determine the reduction in the fine tuning that follows from allowing gaugino masses to be non-degenerate at the unification scale, taking account of the LHC8 bounds on SUSY masses, the Higgs mass bound, gauge coupling unification and the requirement of an acceptable dark matter density. We show that low-fine tuned points fall in the region of gaugino mass ratios predicted by specific unified and string models. For the case of the MSSM the minimum fine tuning is still large, approximately 1:60 allowing for a 3 GeV uncertainty in the Higgs mass (1:500 for the central value), but for the GNMSSM it is below 1:20. We find that the spectrum of SUSY states corresponding to the low-fine tuned points in the GNMSSM is often compressed, weakening the LHC bounds on coloured states. The prospect for testing the remaining low-fine-tuned regions at LHC14 is discussed.

Non-universal gaugino masses and fine tuning implications for SUSY searches in the MSSM and the GNMSSM

Energy Technology Data Exchange (ETDEWEB)

Kaminska, Anna [Oxford Univ. (United Kingdom). Centre for Theoretical Physics; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ross, Graham G. [Oxford Univ. (United Kingdom). Centre for Theoretical Physics; Schmidt-Hoberg, Kai [European Lab. for Particle Physics (CERN), Geneva (Switzerland)

2013-08-15

For the case of the MSSM and the most general form of the NMSSM (GNMSSM) we determine the reduction in the fine tuning that follows from allowing gaugino masses to be non-degenerate at the unification scale, taking account of the LHC8 bounds on SUSY masses, the Higgs mass bound, gauge coupling unification and the requirement of an acceptable dark matter density. We show that low-fine tuned points fall in the region of gaugino mass ratios predicted by specific unified and string models. For the case of the MSSM the minimum fine tuning is still large, approximately 1:60 allowing for a 3 GeV uncertainty in the Higgs mass (1:500 for the central value), but for the GNMSSM it is below 1:20. We find that the spectrum of SUSY states corresponding to the low-fine tuned points in the GNMSSM is often compressed, weakening the LHC bounds on coloured states. The prospect for testing the remaining low-fine-tuned regions at LHC14 is discussed.

Fine-Tuning Neural Patient Question Retrieval Model with Generative Adversarial Networks.

Science.gov (United States)

Tang, Guoyu; Ni, Yuan; Wang, Keqiang; Yong, Qin

2018-01-01

The online patient question and answering (Q&A) system attracts an increasing amount of users in China. Patient will post their questions and wait for doctors' response. To avoid the lag time involved with the waiting and to reduce the workload on the doctors, a better method is to automatically retrieve the semantically equivalent question from the archive. We present a Generative Adversarial Networks (GAN) based approach to automatically retrieve patient question. We apply supervised deep learning based approaches to determine the similarity between patient questions. Then a GAN framework is used to fine-tune the pre-trained deep learning models. The experiment results show that fine-tuning by GAN can improve the performance.

The fine-tuning problem in renormalized perturbation theory: Spontaneously-broken gauge models

International Nuclear Information System (INIS)

Foda, O.E.

1983-01-01

We study the stability of tree-level gauge hierarchies at higher orders in renormalized perturbation theory, in a model with spontaneously-broken gauge symmetries. We confirm previous results indicating that if the model is renormalized using BPHZ, then the tree-level hierarchy is not upset by the radiative corrections. Consequently, no fine-tuning of the initial parameters is required to maintain it, in contrast to the result obtained using Dimensional Renormalization. This verifies the conclusion that the need for fine-tuning, when it arises, is an artifact of the application of a certain class of renormalization schemes. (orig.)

Soflty broken supersymmetry and the fine-tuning problem

Energy Technology Data Exchange (ETDEWEB)

Foda, O.E.

1984-02-20

The supersymmetry of the simple Wess-Zumino model is broken, in the tree-approximation, by adding all possible parity-even(mass)-dimension 2 and 3 terms. The model is then renormalized using BPHZ and the normal product algorithm, such that supersymmetry is only softly broken (in the original sense of Schroer and Symanzik). We show that, within the above renormalization scheme, none of the added breaking terms give rise to technical fine-tuning problems (defined in the sense of Gildener) in larger models, with scalar multiplets and hierarchy of mass scales, which is in contrast to what we obtain via analytic schemes such as dimensional renormalization, or supersymmetry extension of which. The discrepancy (which can be shown to persist in more general models) originates in the inherent local ambiguity in the finite parts of subtracted Feynman integrals. Emphasizing that the issue is purely technical (as opposed to physical) in origin, and that all physical properties are scheme-independent (as they should be), we conclude that the technical fine-tuning problem, in the specific sense used in this paper, being scheme dependent, is not a well-defined issue within the context of renormalized perturbation theory. 30 references.

Soflty broken supersymmetry and the fine-tuning problem

International Nuclear Information System (INIS)

Foda, O.E.

1984-01-01

The supersymmetry of the simple Wess-Zumino model is broken, in the tree-approximation, by adding all possible parity-even[mass]-dimension 2 and 3 terms. The model is then renormalized using BPHZ and the normal product algorithm, such that supersymmetry is only softly broken (in the original sense of Schroer and Symanzik). We show that, within the above renormalization scheme, none of the added breaking terms give rise to technical fine-tuning problems (defined in the sense of Gildener) in larger models, with scalar multiplets and hierarchy of mass scales, which is in contrast to what we obtain via analytic schemes such as dimensional renormalization, or supersymmetry extension of which. The discrepancy (which can be shown to persist in more general models) originates in the inherent local ambiguity in the finite parts of subtracted Feynman integrals. Emphasizing that the issue is purely technical (as opposed to physical) in origin, and that all physical properties are scheme-independent (as they should be), we conclude that the technical fine-tuning problem, in the specific sense used in this paper, being scheme dependent, is not a well-defined issue within the context of renormalized perturbation theory. (orig.)

Hearing aid fine-tuning based on Dutch descriptions.

Science.gov (United States)

Thielemans, Thijs; Pans, Donné; Chenault, Michelene; Anteunis, Lucien

2017-07-01

The aim of this study was to derive an independent fitting assistant based on expert consensus. Two questions were asked: (1) what (Dutch) terms do hearing impaired listeners use nowadays to describe their specific hearing aid fitting problems? (2) What is the expert consensus on how to resolve these complaints by adjusting hearing aid parameters? Hearing aid dispensers provided descriptors that impaired listeners use to describe their reactions to specific hearing aid fitting problems. Hearing aid fitting experts were asked "How would you adjust the hearing aid if its user reports that the aid sounds…?" with the blank filled with each of the 40 most frequently mentioned descriptors. 112 hearing aid dispensers and 15 hearing aid experts. The expert solution with the highest weight value was considered the best solution for that descriptor. Principal component analysis (PCA) was performed to identify a factor structure in fitting problems. Nine fitting problems could be identified resulting in an expert-based, hearing aid manufacturer independent, fine-tuning fitting assistant for clinical use. The construction of an expert-based, hearing aid manufacturer independent, fine-tuning fitting assistant to be used as an additional tool in the iterative fitting process is feasible.

Fine-tuning with brane-localized flux in 6D supergravity

Energy Technology Data Exchange (ETDEWEB)

Niedermann, Florian; Schneider, Robert [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität,Theresienstraße 37, 80333 Munich (Germany); Excellence Cluster Universe,Boltzmannstraße 2, 85748 Garching (Germany)

2016-02-03

There are claims in the literature that the cosmological constant problem could be solved in a braneworld model with two large (micron-sized) supersymmetric extra dimensions. The mechanism relies on two basic ingredients: first, the cosmological constant only curves the compact bulk geometry into a rugby shape while the 4D curvature stays flat. Second, a brane-localized flux term is introduced in order to circumvent Weinberg’s fine-tuning argument, which otherwise enters here through a backdoor via the flux quantization condition. In this paper, we show that the latter mechanism does not work in the way it was designed: the only localized flux coupling that guarantees a flat on-brane geometry is one which preserves the scale invariance of the bulk theory. Consequently, Weinberg’s argument applies, making a fine-tuning necessary again. The only remaining window of opportunity lies within scale invariance breaking brane couplings, for which the tuning could be avoided. Whether the corresponding 4D curvature could be kept under control and in agreement with the observed value will be answered in our companion paper http://arxiv.org/abs/1512.03800.

Fine-tuning with brane-localized flux in 6D supergravity

International Nuclear Information System (INIS)

Niedermann, Florian; Schneider, Robert

2016-01-01

There are claims in the literature that the cosmological constant problem could be solved in a braneworld model with two large (micron-sized) supersymmetric extra dimensions. The mechanism relies on two basic ingredients: first, the cosmological constant only curves the compact bulk geometry into a rugby shape while the 4D curvature stays flat. Second, a brane-localized flux term is introduced in order to circumvent Weinberg’s fine-tuning argument, which otherwise enters here through a backdoor via the flux quantization condition. In this paper, we show that the latter mechanism does not work in the way it was designed: the only localized flux coupling that guarantees a flat on-brane geometry is one which preserves the scale invariance of the bulk theory. Consequently, Weinberg’s argument applies, making a fine-tuning necessary again. The only remaining window of opportunity lies within scale invariance breaking brane couplings, for which the tuning could be avoided. Whether the corresponding 4D curvature could be kept under control and in agreement with the observed value will be answered in our companion paper http://arxiv.org/abs/1512.03800.

Pre - big bang inflation requires fine tuning

Energy Technology Data Exchange (ETDEWEB)

Turner, Michael S. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Weinberg, Erick J. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

1997-10-01

The pre-big-bang cosmology inspired by superstring theories has been suggested as an alternative to slow-roll inflation. We analyze, in both the Jordan and Einstein frames, the effect of spatial curvature on this scenario and show that too much curvature --- of either sign --- reduces the duration of the inflationary era to such an extent that the flatness and horizon problems are not solved. Hence, a fine-tuning of initial conditions is required to obtain enough inflation to solve the cosmological problems.

The microRNA-132/212 family fine-tunes multiple targets in Angiotensin II signalling in cardiac fibroblasts

DEFF Research Database (Denmark)

Eskildsen, Tilde V; Schneider, Mikael; Sandberg, Maria B

2015-01-01

INTRODUCTION: MicroRNAs (miRNAs) are emerging as key regulators of cardiovascular development and disease; however, the cardiac miRNA target molecules are not well understood. We and others have described the Angiotensin II (AngII)-induced miR-132/212 family as novel regulators of cardiovascular...... in silico and in vitro experiments to identify miR-132/212 molecular targets in primary rat cardiac fibroblasts. RESULTS: MiR-132/212 overexpression increased fibroblast cell size and mRNA arrays detected several hundred genes that were differentially expressed, including a wide panel of receptors...... pathways that fine-tuned by miR-132/212, suggesting a role for this miRNA family as master signalling switches in cardiac fibroblasts. Our data underscore the potential for miRNA tools to manipulate a large array of molecules and thereby control biological function....

Dynamic Mode Tuning of Ultrasonic Guided Wave Using an Array Transducer

International Nuclear Information System (INIS)

Kim, Young H.; Song, Sung J.; Park, Joon S.; Kim, Jae H.; Eom, Heung S.

2005-01-01

Ultrasonic guided waves have been widely employed for long range inspection of structures such as plates, rods and pipes. There are numerous modes with different wave velocities, and the appropriate mode selection is one of key techniques in the application of guided waves. In the present work, phase tuning by an array transducer was applied to generate ultrasonic guided waves. For this purpose, 8-channel ultrasonic pulser/receiver and their controller which enables sequential activation of each channels with given time delay were developed. Eight transducers were fabricated in order to generate guided waves by using an array transducer. The selective tuning of wave mode can be achieved by changing the interval between elements of an array transducer

Implications for new physics from fine-tuning arguments 1. Application to SUSY and seesaw cases

International Nuclear Information System (INIS)

Alberto Casas, J.; Hidalgo, Irene; Espinosa, Jose R.

2004-01-01

We revisit the standard argument to estimate the scale of new physics (NP) beyond the SM, based on the sensitivity of the Higgs mass to quadratic divergences. Although this argument is arguably naive, the corresponding estimate, Λ SM SM . One can obtain more precise implications from fine-tuning arguments in specific examples of NP. Here we consider SUSY and right-handed (seesaw) neutrinos. SUSY is a typical example for which the previous general estimate is indeed conservative: the MSSM is fine-tuned a few %, even for soft masses of a few hundred GeV. In contrast, other SUSY scenarios, in particular those with low-scale SUSY breaking, can easily saturate the general bound on Λ SM . The seesaw mechanism requires large fine-tuning if M R > or approx.10 7 GeV, unless there is additional NP (SUSY being a favourite option). (author)

Paediatric frontal chest radiograph screening with fine-tuned convolutional neural networks

CSIR Research Space (South Africa)

Gerrand, Jonathan D

2017-07-01

Full Text Available of fine-tuned convolutional neural networks (CNN). We use two popular CNN models that are pre-trained on a large natural image dataset and two distinct datasets containing paediatric and adult radiographs respectively. Evaluation is performed using a 5...

Fine tuning support vector machines for short-term wind speed forecasting

International Nuclear Information System (INIS)

Zhou Junyi; Shi Jing; Li Gong

2011-01-01

Research highlights: → A systematic approach to tuning SVM models for wind speed prediction is proposed. → Multiple kernel functions and a wide range of tuning parameters are evaluated, and optimal parameters for each kernel function are obtained. → It is found that the forecasting performance of SVM is closely related to the dynamic characteristics of wind speed. → Under the optimal combination of parameters, different kernels give comparable forecasting accuracy. -- Abstract: Accurate forecasting of wind speed is critical to the effective harvesting of wind energy and the integration of wind power into the existing electric power grid. Least-squares support vector machines (LS-SVM), a powerful technique that is widely applied in a variety of classification and function estimation problems, carries great potential for the application of short-term wind speed forecasting. In this case, tuning the model parameters for optimal forecasting accuracy is a fundamental issue. This paper, for the first time, presents a systematic study on fine tuning of LS-SVM model parameters for one-step ahead wind speed forecasting. Three SVM kernels, namely linear, Gaussian, and polynomial kernels, are implemented. The SVM parameters considered include the training sample size, SVM order, regularization parameter, and kernel parameters. The results show that (1) the performance of LS-SVM is closely related to the dynamic characteristics of wind speed; (2) all parameters investigated greatly affect the performance of LS-SVM models; (3) under the optimal combination of parameters after fine tuning, the three kernels give comparable forecasting accuracy; (4) the performance of linear kernel is worse than the other two kernels when the training sample size or SVM order is small. In addition, LS-SVMs are compared against the persistence approach, and it is found that they can outperform the persistence model in the majority of cases.

Enhanced photoconductivity and fine response tuning in nanostructured porous silicon microcavities

Energy Technology Data Exchange (ETDEWEB)

Urteaga, R; MarIn, O; Acquaroli, L N; Schmidt, J A; Koropecki, R R [INTEC-UNL-CONICET, Guemes 3450 - 3000 Santa Fe (Argentina); Comedi, D, E-mail: rkoro@intec.ceride.gov.a [CONICET y LAFISO, Departamento de Fisica, FACET, Universidad Nacional de Tucuman (Argentina)

2009-05-01

We used light confinement in optical microcavities to achieve a strong enhancement and a precise wavelength tunability of the electrical photoconductance of nanostructured porous silicon (PS). The devices consist of a periodic array of alternating PS layers, electrochemically etched to have high and low porosities - and therefore distinct dielectric functions. A central layer having a doubled thickness breaks up the symmetry of the one-dimensional photonic structure, producing a resonance in the photonic band gap that is clearly observed in the reflectance spectrum. The devices were transferred to a glass coated with a transparent SnO{sub 2} electrode, while an Al contact was evaporated on its back side. The electrical conductance was measured as a function of the photon energy. A strong enhancement of the conductance is obtained in a narrow (17nm FWHM) band peaking at the resonance. We present experimental results of the angular dependence of this photoconductance peak energy, and propose an explanation of the conductivity behaviour supported by calculations of the internal electromagnetic field. These devices are promising candidates for finely tuned photoresistors with potential application as chemical sensors and biosensors.

One-loop analysis of the electroweak breaking in supersymmetric models and the fine-tuning problem

CERN Document Server

De Carlos, B

1993-01-01

We examine the electroweak breaking mechanism in the minimal supersymmetric standard model (MSSM) using the {\\em complete} one-loop effective potential $V_1$. First, we study what is the region of the whole MSSM parameter space (i.e. $M_{1/2},m_o,\\mu,...$) that leads to a succesful $SU(2)\\times U(1)$ breaking with an acceptable top quark mass. In doing this it is observed that all the one-loop corrections to $V_1$ (even the apparently small ones) must be taken into account in order to get reliable results. We find that the allowed region of parameters is considerably enhanced with respect to former "improved" tree level results. Next, we study the fine-tuning problem associated with the high sensitivity of $M_Z$ to $h_t$ (the top Yukawa coupling). Again, we find that this fine-tuning is appreciably smaller once the one-loop effects are considered than in previous tree level calculations. Finally, we explore the ambiguities and limitations of the ordinary criterion to estimate the degree of fine-tuning. As a r...

Fine-tuning implications for complementary dark matter and LHC SUSY searches

CERN Document Server

Cassel, S; Kraml, S; Lessa, A; Ross, G G

2011-01-01

The requirement that SUSY should solve the hierarchy problem without undue fine-tuning imposes severe constraints on the new supersymmetric states. With the MSSM spectrum and soft SUSY breaking originating from universal scalar and gaugino masses at the Grand Unification scale, we show that the low-fine-tuned regions fall into two classes that will require complementary collider and dark matter searches to explore in the near future. The first class has relatively light gluinos or squarks which should be found by the LHC in its first run. We identify the multijet plus E_T^miss signal as the optimal channel and determine the discovery potential in the first run. The second class has heavier gluinos and squarks but the LSP has a significant Higgsino component and should be seen by the next generation of direct dark matter detection experiments. The combined information from the 7 TeV LHC run and the next generation of direct detection experiments can test almost all of the CMSSM parameter space consistent with ...

A systematic approach for fine-tuning of fuzzy controllers applied to WWTPs

DEFF Research Database (Denmark)

Ruano, M.V.; Ribes, J.; Sin, Gürkan

2010-01-01

A systematic approach for fine-tuning fuzzy controllers has been developed and evaluated for an aeration control system implemented in a WWTR The challenge with the application of fuzzy controllers to WWTPs is simply that they contain many parameters, which need to be adjusted for different WWTP ...

Fine tuning of work practices of common radiological investigations performed using computed radiography system

International Nuclear Information System (INIS)

Livingstone, Roshan S.; Timothy Peace, B.S.; Sunny, S.; Victor Raj, D.

2007-01-01

Introduction: The advent of the computed radiography (CR) has brought about remarkable changes in the field of diagnostic radiology. A relatively large cross-section of the human population is exposed to ionizing radiation on account of common radiological investigations. This study is intended to audit radiation doses imparted to patients during common radiological investigations involving the use of CR systems. Method: The entrance surface doses (ESD) were measured using thermoluminescent dosimeters (TLD) for various radiological investigations performed using the computed radiography (CR) systems. Optimization of radiographic techniques and radiation doses was done by fine tuning the work practices. Results and conclusion: Reduction of radiation doses as high as 47% was achieved during certain investigations with the use of optimized exposure factors and fine-tuned work practices

Two-dimensional diced scintillator array for innovative, fine-resolution gamma camera

International Nuclear Information System (INIS)

Fujita, T.; Kataoka, J.; Nishiyama, T.; Ohsuka, S.; Nakamura, S.; Yamamoto, S.

2014-01-01

We are developing a technique to fabricate fine spatial resolution (FWHM<0.5mm) and cost-effective photon counting detectors, by using silicon photomultipliers (SiPMs) coupled with a finely pixelated scintillator plate. Unlike traditional X-ray imagers that use a micro-columnar CsI(Tl) plate, we can pixelate various scintillation crystal plates more than 1 mm thick, and easily develop large-area, fine-pitch scintillator arrays with high precision. Coupling a fine pitch scintillator array with a SiPM array results in a compact, fast-response detector that is ideal for X-ray, gamma-ray, and charged particle detection as used in autoradiography, gamma cameras, and photon counting CTs. As the first step, we fabricated a 2-D, cerium-doped Gd 3 Al 2 Ga 3 O 12 (Ce:GAGG) scintillator array of 0.25 mm pitch, by using a dicing saw to cut micro-grooves 50μm wide into a 1.0 mm thick Ce:GAGG plate. The scintillator plate is optically coupled with a 3.0×3.0mm pixel 4×4 SiPM array and read-out via the resistive charge-division network. Even when using this simple system as a gamma camera, we obtained excellent spatial resolution of 0.48 mm (FWHM) for 122 keV gamma-rays. We will present our plans to further improve the signal-to-noise ratio in the image, and also discuss a variety of possible applications in the near future

Thyroid Nodule Classification in Ultrasound Images by Fine-Tuning Deep Convolutional Neural Network.

Science.gov (United States)

Chi, Jianning; Walia, Ekta; Babyn, Paul; Wang, Jimmy; Groot, Gary; Eramian, Mark

2017-08-01

With many thyroid nodules being incidentally detected, it is important to identify as many malignant nodules as possible while excluding those that are highly likely to be benign from fine needle aspiration (FNA) biopsies or surgeries. This paper presents a computer-aided diagnosis (CAD) system for classifying thyroid nodules in ultrasound images. We use deep learning approach to extract features from thyroid ultrasound images. Ultrasound images are pre-processed to calibrate their scale and remove the artifacts. A pre-trained GoogLeNet model is then fine-tuned using the pre-processed image samples which leads to superior feature extraction. The extracted features of the thyroid ultrasound images are sent to a Cost-sensitive Random Forest classifier to classify the images into "malignant" and "benign" cases. The experimental results show the proposed fine-tuned GoogLeNet model achieves excellent classification performance, attaining 98.29% classification accuracy, 99.10% sensitivity and 93.90% specificity for the images in an open access database (Pedraza et al. 16), while 96.34% classification accuracy, 86% sensitivity and 99% specificity for the images in our local health region database.

A novel approach to finely tuned supersymmetric standard models: The case of the non-universal Higgs mass model

Science.gov (United States)

Yamaguchi, Masahiro; Yin, Wen

2018-02-01

Discarding the prejudice about fine tuning, we propose a novel and efficient approach to identify relevant regions of fundamental parameter space in supersymmetric models with some amount of fine tuning. The essential idea is the mapping of experimental constraints at a low-energy scale, rather than the parameter sets, to those of the fundamental parameter space. Applying this method to the non-universal Higgs mass model, we identify a new interesting superparticle mass pattern where some of the first two generation squarks are light whilst the stops are kept heavy as 6 TeV. Furthermore, as another application of this method, we show that the discrepancy of the muon anomalous magnetic dipole moment can be filled by a supersymmetric contribution within the 1{σ} level of the experimental and theoretical errors, which was overlooked by previous studies due to the extremely fine tuning required.

Poster - 53: Improving inter-linac DMLC IMRT dose precision by fine tuning of MLC leaf calibration

International Nuclear Information System (INIS)

Nakonechny, Keith; Tran, Muoi; Sasaki, David; Beck, James; Poirier, Yannick; Malkoske, Kyle

2016-01-01

Purpose: To develop a method to improve the inter-linac precision of DMLC IMRT dosimetry. Methods: The distance between opposing MLC leaf banks (“gap size”) can be finely tuned on Varian linacs. The dosimetric effect due to small deviations from the nominal gap size (“gap error”) was studied by introducing known errors for several DMLC sliding gap sizes, and for clinical plans based on the TG119 test cases. The plans were delivered on a single Varian linac and the relationship between gap error and the corresponding change in dose was measured. The plans were also delivered on eight Varian 2100 series linacs (at two institutions) in order to quantify the inter-linac variation in dose before and after fine tuning the MLC calibration. Results: The measured dose differences for each field agreed well with the predictions of LoSasso et al. Using the default MLC calibration, the variation in the physical MLC gap size was determined to be less than 0.4 mm between all linacs studied. The dose difference between the linacs with the largest and smallest physical gap was up to 5.4% (spinal cord region of the head and neck TG119 test case). This difference was reduced to 2.5% after fine tuning the MLC gap calibration. Conclusions: The inter-linac dose precision for DMLC IMRT on Varian linacs can be improved using a simple modification of the MLC calibration procedure that involves fine adjustment of the nominal gap size.

Poster - 53: Improving inter-linac DMLC IMRT dose precision by fine tuning of MLC leaf calibration

Energy Technology Data Exchange (ETDEWEB)

Nakonechny, Keith; Tran, Muoi; Sasaki, David; Beck, James; Poirier, Yannick; Malkoske, Kyle [Simcoe-Muskoka Regional Cancer Centre (Canada)

2016-08-15

Purpose: To develop a method to improve the inter-linac precision of DMLC IMRT dosimetry. Methods: The distance between opposing MLC leaf banks (“gap size”) can be finely tuned on Varian linacs. The dosimetric effect due to small deviations from the nominal gap size (“gap error”) was studied by introducing known errors for several DMLC sliding gap sizes, and for clinical plans based on the TG119 test cases. The plans were delivered on a single Varian linac and the relationship between gap error and the corresponding change in dose was measured. The plans were also delivered on eight Varian 2100 series linacs (at two institutions) in order to quantify the inter-linac variation in dose before and after fine tuning the MLC calibration. Results: The measured dose differences for each field agreed well with the predictions of LoSasso et al. Using the default MLC calibration, the variation in the physical MLC gap size was determined to be less than 0.4 mm between all linacs studied. The dose difference between the linacs with the largest and smallest physical gap was up to 5.4% (spinal cord region of the head and neck TG119 test case). This difference was reduced to 2.5% after fine tuning the MLC gap calibration. Conclusions: The inter-linac dose precision for DMLC IMRT on Varian linacs can be improved using a simple modification of the MLC calibration procedure that involves fine adjustment of the nominal gap size.

MSSM fine tuning problem and dynamical suppression of the Higgs mass parameters

International Nuclear Information System (INIS)

Kobayashi, Tatsuo; Terao, Haruhiko

2004-01-01

There have been several proposals for extension of the MSSM so as to ameliorate the fine tuning problem, which may be classified roughly into two categories; scenarios with enhanced quartic Higgs couplings and scenarios with radiatively stable Higgs soft masses. After a brief remark on some generic aspects of these approaches, we show a scenario with use of superconformal dynamics suppressing the Higgs mass parameters. (author)

MSSM fine tuning problem and dynamical suppression of the Higgs mass parameters

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Tatsuo [Kyoto Univ., Dept. of Physics, Kyoto (Japan); Terao, Haruhiko [Kanazawa Univ., Institute for Theoretical Physics, Kanazawa, Ishikawa (Japan)

2004-12-01

There have been several proposals for extension of the MSSM so as to ameliorate the fine tuning problem, which may be classified roughly into two categories; scenarios with enhanced quartic Higgs couplings and scenarios with radiatively stable Higgs soft masses. After a brief remark on some generic aspects of these approaches, we show a scenario with use of superconformal dynamics suppressing the Higgs mass parameters. (author)

Automated tuning of an eight-channel cardiac transceive array at 7 tesla using piezoelectric actuators.

Science.gov (United States)

Keith, Graeme A; Rodgers, Christopher T; Hess, Aaron T; Snyder, Carl J; Vaughan, J Thomas; Robson, Matthew D

2015-06-01

Ultra-high field (UHF) MR scanning in the body requires novel coil designs due to B1 field inhomogeneities. In the transverse electromagnetic field (TEM) design, maximum B1 transmit power can only be achieved if each individual transmit element is tuned and matched for different coil loads, which requires a considerable amount of valuable scanner time. An integrated system for autotuning a multichannel parallel transmit (pTx) cardiac TEM array was devised, using piezoelectric actuators, power monitoring equipment and control software. The reproducibility and performance of the system were tested and the power responses of the coil elements were profiled. An automated optimization method was devised and evaluated. The time required to tune an eight-element pTx cardiac RF array was reduced from a mean of 30 min to less than 10 min with the use of this system. Piezoelectric actuators are an attractive means of tuning RF coil arrays to yield more efficient B1 transmission into the subject. An automated mechanism for tuning these elements provides a practical solution for cardiac imaging at UHF, bringing this technology closer to clinical use. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Automatic recognition of 3D GGO CT imaging signs through the fusion of hybrid resampling and layer-wise fine-tuning CNNs.

Science.gov (United States)

Han, Guanghui; Liu, Xiabi; Zheng, Guangyuan; Wang, Murong; Huang, Shan

2018-06-06

Ground-glass opacity (GGO) is a common CT imaging sign on high-resolution CT, which means the lesion is more likely to be malignant compared to common solid lung nodules. The automatic recognition of GGO CT imaging signs is of great importance for early diagnosis and possible cure of lung cancers. The present GGO recognition methods employ traditional low-level features and system performance improves slowly. Considering the high-performance of CNN model in computer vision field, we proposed an automatic recognition method of 3D GGO CT imaging signs through the fusion of hybrid resampling and layer-wise fine-tuning CNN models in this paper. Our hybrid resampling is performed on multi-views and multi-receptive fields, which reduces the risk of missing small or large GGOs by adopting representative sampling panels and processing GGOs with multiple scales simultaneously. The layer-wise fine-tuning strategy has the ability to obtain the optimal fine-tuning model. Multi-CNN models fusion strategy obtains better performance than any single trained model. We evaluated our method on the GGO nodule samples in publicly available LIDC-IDRI dataset of chest CT scans. The experimental results show that our method yields excellent results with 96.64% sensitivity, 71.43% specificity, and 0.83 F1 score. Our method is a promising approach to apply deep learning method to computer-aided analysis of specific CT imaging signs with insufficient labeled images. Graphical abstract We proposed an automatic recognition method of 3D GGO CT imaging signs through the fusion of hybrid resampling and layer-wise fine-tuning CNN models in this paper. Our hybrid resampling reduces the risk of missing small or large GGOs by adopting representative sampling panels and processing GGOs with multiple scales simultaneously. The layer-wise fine-tuning strategy has ability to obtain the optimal fine-tuning model. Our method is a promising approach to apply deep learning method to computer-aided analysis

Precision tests and fine tuning in twin Higgs models

Science.gov (United States)

Contino, Roberto; Greco, Davide; Mahbubani, Rakhi; Rattazzi, Riccardo; Torre, Riccardo

2017-11-01

We analyze the parametric structure of twin Higgs (TH) theories and assess the gain in fine tuning which they enable compared to extensions of the standard model with colored top partners. Estimates show that, at least in the simplest realizations of the TH idea, the separation between the mass of new colored particles and the electroweak scale is controlled by the coupling strength of the underlying UV theory, and that a parametric gain is achieved only for strongly-coupled dynamics. Motivated by this consideration we focus on one of these simple realizations, namely composite TH theories, and study how well such constructions can reproduce electroweak precision data. The most important effect of the twin states is found to be the infrared contribution to the Higgs quartic coupling, while direct corrections to electroweak observables are subleading and negligible. We perform a careful fit to the electroweak data including the leading-logarithmic corrections to the Higgs quartic up to three loops. Our analysis shows that agreement with electroweak precision tests can be achieved with only a moderate amount of tuning, in the range 5%-10%, in theories where colored states have mass of order 3-5 TeV and are thus out of reach of the LHC. For these levels of tuning, larger masses are excluded by a perturbativity bound, which makes these theories possibly discoverable, hence falsifiable, at a future 100 TeV collider.

Discrete tuning concept for fiber-integrated lasers based on tailored FBG arrays and a theta cavity layout.

Science.gov (United States)

Tiess, Tobias; Becker, Martin; Rothhardt, Manfred; Bartelt, Hartmut; Jäger, Matthias

2017-03-15

We demonstrate a novel tuning concept for pulsed fiber-integrated lasers with a fiber Bragg grating (FBG) array as a discrete and tailored spectral filter, as well as a modified laser design. Based on a theta cavity layout, the structural delay lines originating from the FBG array are balanced, enabling a constant repetition rate and stable pulse properties over the full tuning range. The emission wavelength is electrically tuned with respect to the filter properties based on an adapted temporal gating scheme using an acousto-optic modulator. This concept has been investigated with an Yb-doped fiber laser, demonstrating excellent emission properties with high signal contrast (>35  dB) and narrow linewidth (<150  pm) over a tuning range of 25 nm.

Do we live in the best of all possible worlds? The fine-tuning of the constants of nature

Directory of Open Access Journals (Sweden)

Naumann Thomas

2017-01-01

Full Text Available Our existence depends on a variety of constants which appear to be extremely fine-tuned to allow for the existence of life. These include the number of spatial dimensions, the strengths of the forces, the masses of the particles, the composition of the Universe and others. On the occasion of the 300th anniversary of the death of G.W. Leibniz we discuss the question of whether we live in the “Best of all Worlds”. The hypothesis of a multiverse could explain the mysterious fine tuning of so many fundamental quantities. Anthropic arguments are critically reviewed.

Do we live in the best of all possible worlds? The fine-tuning of the constants of nature

Science.gov (United States)

Naumann, Thomas

2017-12-01

Our existence depends on a variety of constants which appear to be extremely fine-tuned to allow for the existence of life. These include the number of spatial dimensions, the strengths of the forces, the masses of the particles, the composition of the Universe and others. On the occasion of the 300th anniversary of the death of G.W. Leibniz we discuss the question of whether we live in the "Best of all Worlds". The hypothesis of a multiverse could explain the mysterious fine tuning of so many fundamental quantities. Anthropic arguments are critically reviewed.

Relaxion cosmology and the price of fine-tuning

Science.gov (United States)

Di Chiara, Stefano; Kannike, Kristjan; Marzola, Luca; Racioppi, Antonio; Raidal, Martti; Spethmann, Christian

2016-05-01

The relaxion scenario presents an intriguing extension of the standard model in which the particle introduced to solve to the strong C P problem, the axion, also achieves the dynamical relaxation of the Higgs boson mass term. In this work we complete this framework by proposing a scenario of inflationary cosmology that is consistent with all the observational constraints: the relaxion hybrid inflation with an asymmetric waterfall. In our scheme, the vacuum energy of the inflaton drives inflation in a natural way while the relaxion slow rolls. The constraints on the present inflationary observables are then matched through a subsequent inflationary epoch driven by the inflaton. We quantify the amount of fine-tuning of the proposed inflation scenario, concluding that the inflaton sector severely decreases the naturalness of the theory.

Fine tuning power diodes with irradiation

International Nuclear Information System (INIS)

Tarneja, K.S.; Bartko, J.; Johnson, J.E.

1976-01-01

Diodes of a particular type are fine tuned with irradiation to optimize the reverse recovery time while minimizing forward voltage drop and providing more uniform electrical characcteristics. The initial and desired minority carrier lifetimes in the anode region of the type are determined as a function of forward voltage drop and reverse recovery time, and the minority carrier radiation damage factor is determined for a desired type of diode and radiation source. The radiation dosage to achieve the desired carrier lifetime with the radiation source is thereafter determined from the function 1/tau = 1/tau 0 + K phi, where tau is the desired minority carrier lifetime, tau 0 is the initial minority carrier lifetime, K is the determined minority carrier radiation damage factor and phi is the radiation dosage. A major surface and preferably the major surface adjoining the anode region of the diodes is then irradiated with the radiation source to the determined radiation dosage. Preferably, the radiation dosage is between about 1 X 10 12 and 5 X 10 13 e/cm 2 , with electron radiation of intensity between 1 and 3 MeV

Highly stable and finely tuned magnetic fields generated by permanent magnet assemblies.

Science.gov (United States)

Danieli, E; Perlo, J; Blümich, B; Casanova, F

2013-05-03

Permanent magnetic materials are the only magnetic source that can be used to generate magnetic fields without power consumption or maintenance. Such stand-alone magnets are very attractive for many scientific and engineering areas, but they suffer from poor temporal field stability, which arises from the strong sensitivity of the magnetic materials and mechanical support to temperature variation. In this work, we describe a highly efficient method useful to cancel the temperature coefficient of permanent magnet assemblies in a passive and accurate way. It is based on the combination of at least two units made of magnetic materials with different temperature coefficients arranged in such a way that the ratio of the fields generated by each unit matches the ratio of their effective temperature coefficients defined by both the magnetic and mechanical contributions. Although typically available magnetic materials have negative temperature coefficients, the cancellation is achieved by aligning the fields generated by each unit in the opposite direction. We demonstrate the performance of this approach by stabilizing the field generated by a dipolar Halbach magnet, recently proposed to achieve high field homogeneity. Both the field drift and the homogeneity are monitored via nuclear magnetic resonance spectroscopy experiments. The results demonstrate the compatibility of the thermal compensation approach with existing strategies useful to fine-tune the spatial dependence of the field generated by permanent magnet arrays.

Classical Causal Models for Bell and Kochen-Specker Inequality Violations Require Fine-Tuning

Directory of Open Access Journals (Sweden)

Eric G. Cavalcanti

2018-04-01

Full Text Available Nonlocality and contextuality are at the root of conceptual puzzles in quantum mechanics, and they are key resources for quantum advantage in information-processing tasks. Bell nonlocality is best understood as the incompatibility between quantum correlations and the classical theory of causality, applied to relativistic causal structure. Contextuality, on the other hand, is on a more controversial foundation. In this work, I provide a common conceptual ground between nonlocality and contextuality as violations of classical causality. First, I show that Bell inequalities can be derived solely from the assumptions of no signaling and no fine-tuning of the causal model. This removes two extra assumptions from a recent result from Wood and Spekkens and, remarkably, does not require any assumption related to independence of measurement settings—unlike all other derivations of Bell inequalities. I then introduce a formalism to represent contextuality scenarios within causal models and show that all classical causal models for violations of a Kochen-Specker inequality require fine-tuning. Thus, the quantum violation of classical causality goes beyond the case of spacelike-separated systems and already manifests in scenarios involving single systems.

Chiral Symmetry Restoration, Naturalness and the Absence of Fine-Tuning I: Global Theories

CERN Document Server

Lynn, Bryan W.

2013-01-01

The Standard Model (SM), and the scalar sector of its zero-gauge-coupling limit -- the chiral-symmetric limit of the Gell Mann-Levy Model (GML) -- have been shown not to suffer from a Higgs Fine-Tuning (FT) problem. All ultraviolet quadratic divergences (UVQD) are absorbed into the mass-squared of pseudo Nambu-Goldstone (pNGB) bosons, in GML. Since chiral SU(2)_{L-R} symmetry is restored as the pNGB mass-squared or as the Higgs vacuum expectation value (VEV) are taken to 0, small values of these quantities and of the Higgs mass are natural, and therefore not Fine-Tuned. In this letter, we extend our results on the absence of FT to a wide class of high-mass-scale (M_{Heavy}>>m_{Higgs}) extensions to a simplified SO(2) version of GML. We explicitly demonstrate naturalness and no-FT for two examples of heavy physics, both SO(2) singlets: a heavy (M_S >> m_{Higgs}) real scalar field (with or without a VEV); and a right-handed Type 1 See-Saw Majorana neutrino with M_R >> m_{Higgs}. We prove that for |q^2| <<...

On the fine-tuning problem in minimal SO(10) SUSY-GUT

International Nuclear Information System (INIS)

Hempfling, R.

1994-05-01

In grand unified theories (GUT) based on SO(10) all fermions of one generation are embedded in a single representation. As a result, the top quark, the bottom quark, and the τ lepton have the same Yukawa coupling at the GUT scale. This implies a very large ratio of Higgs vacuum expectation values, tanβ≅m t /m b . In this letter we show that GUT threshold correction to the universal Higgs mass parameter can solve the fine-tuning problem associated with such large values of tan β. (orig.)

Quantum Big Bang without fine-tuning in a toy-model

International Nuclear Information System (INIS)

Znojil, Miloslav

2012-01-01

The question of possible physics before Big Bang (or after Big Crunch) is addressed via a schematic non-covariant simulation of the loss of observability of the Universe. Our model is drastically simplified by the reduction of its degrees of freedom to the mere finite number. The Hilbert space of states is then allowed time-dependent and singular at the critical time t = t c . This option circumvents several traditional theoretical difficulties in a way illustrated via solvable examples. In particular, the unitary evolution of our toy-model quantum Universe is shown interruptible, without any fine-tuning, at the instant of its bang or collapse t = t c .

Quantum Big Bang without fine-tuning in a toy-model

Science.gov (United States)

Znojil, Miloslav

2012-02-01

The question of possible physics before Big Bang (or after Big Crunch) is addressed via a schematic non-covariant simulation of the loss of observability of the Universe. Our model is drastically simplified by the reduction of its degrees of freedom to the mere finite number. The Hilbert space of states is then allowed time-dependent and singular at the critical time t = tc. This option circumvents several traditional theoretical difficulties in a way illustrated via solvable examples. In particular, the unitary evolution of our toy-model quantum Universe is shown interruptible, without any fine-tuning, at the instant of its bang or collapse t = tc.

Chemically Tuning the Localized Surface Plasmon Resonances of Gold Nanostructure Arrays

KAUST Repository

Zheng, Yue Bing

2009-04-30

We report on chemical etching of ordered Au nanostructure arrays to continuously tune their localized surface plasmon resonances (LSPR). Real-time extinction spectra were recorded from both Au nanodisks and nanospheres immobilized on glass substrates when immersed in Au etchant. The time-dependent LSPR frequencies, intensities, and bandwidths were studied theoretically with discrete dipole approximations and the Mie solution, and they were correlated with the evolution of the etched Au nanostructures\\' morphology (as examined by atomic force microscopy). Since this chemical etching method can conveniently and accurately tune LSPR, it offers precise control of plasmonic properties and can be useful in applications such as surfaceenhanced Raman spectroscopy and molecular resonance spectroscopy. © 2009 American Chemical Society.

Convolutional Neural Networks for Medical Image Analysis: Full Training or Fine Tuning?

OpenAIRE

Tajbakhsh, Nima; Shin, Jae Y.; Gurudu, Suryakanth R.; Hurst, R. Todd; Kendall, Christopher B.; Gotway, Michael B.; Liang, Jianming

2017-01-01

Training a deep convolutional neural network (CNN) from scratch is difficult because it requires a large amount of labeled training data and a great deal of expertise to ensure proper convergence. A promising alternative is to fine-tune a CNN that has been pre-trained using, for instance, a large set of labeled natural images. However, the substantial differences between natural and medical images may advise against such knowledge transfer. In this paper, we seek to answer the following centr...

Nonparametric Fine Tuning of Mixtures: Application to Non-Life Insurance Claims Distribution Estimation

Science.gov (United States)

Sardet, Laure; Patilea, Valentin

When pricing a specific insurance premium, actuary needs to evaluate the claims cost distribution for the warranty. Traditional actuarial methods use parametric specifications to model claims distribution, like lognormal, Weibull and Pareto laws. Mixtures of such distributions allow to improve the flexibility of the parametric approach and seem to be quite well-adapted to capture the skewness, the long tails as well as the unobserved heterogeneity among the claims. In this paper, instead of looking for a finely tuned mixture with many components, we choose a parsimonious mixture modeling, typically a two or three-component mixture. Next, we use the mixture cumulative distribution function (CDF) to transform data into the unit interval where we apply a beta-kernel smoothing procedure. A bandwidth rule adapted to our methodology is proposed. Finally, the beta-kernel density estimate is back-transformed to recover an estimate of the original claims density. The beta-kernel smoothing provides an automatic fine-tuning of the parsimonious mixture and thus avoids inference in more complex mixture models with many parameters. We investigate the empirical performance of the new method in the estimation of the quantiles with simulated nonnegative data and the quantiles of the individual claims distribution in a non-life insurance application.

A fortunate universe life in a finely tuned cosmos

CERN Document Server

Lewis, Geraint F

2016-01-01

Over the last forty years, scientists have uncovered evidence that if the Universe had been forged with even slightly different properties, life as we know it - and life as we can imagine it - would be impossible. Join us on a journey through how we understand the Universe, from its most basic particles and forces, to planets, stars and galaxies, and back through cosmic history to the birth of the cosmos. Conflicting notions about our place in the Universe are defined, defended and critiqued from scientific, philosophical and religious viewpoints. The authors' engaging and witty style addresses what fine-tuning might mean for the future of physics and the search for the ultimate laws of nature. Tackling difficult questions and providing thought-provoking answers, this volumes challenges us to consider our place in the cosmos, regardless of our initial convictions.

Anthropic Reasoning about Fine-Tuning, and Neoclassical Cosmology: Providence, Omnipresence, and Observation Selection Theory

Science.gov (United States)

Walker, Theodore, Jr.

2011-10-01

Anthropic reasoning about observation selection effects upon the appearance of cosmic providential fine-tuning (fine-tuning that provides for life) is often motivated by a desire to avoid theological implications (implications favoring the idea of a divine cosmic provider) without appealing to sheer lucky-for-us-cosmic-jackpot happenstance and coincidence. Cosmic coincidence can be rendered less incredible by appealing to a multiverse context. Cosmic providence can be rendered non-theological by appealing to an agent-less providential purpose, or by appealing to less-than-omnipresent/local providers, such as alien intelligences creating life- providing baby universes. Instead of choosing either cosmic coincidence or cosmic providence, as though they were mutually exclusive; it is better to accept both. Neoclassical thought accepts coincidence and providence, plus many local providers and one omnipresent provider. Moreover, fundamental observation selection theory should distinguish the many local observers of some events from the one omnipresent observer of all events. Accepting both coincidence and providence avoids classical theology (providence without coincidence) and classical atheism (coincidence without providence), but not neoclassical theology (providence with coincidence). Cosmology cannot avoid the idea of an all-inclusive omnipresent providential dice-throwing living-creative whole of reality, an idea essential to neoclassical theology, and to neoclassical cosmology.

Avoiding the blue spectrum and the fine-tuning of initial conditions in hybrid inflation

International Nuclear Information System (INIS)

Clesse, Sebastien; Rocher, Jonathan

2009-01-01

Hybrid inflation faces two well-known problems: the blue spectrum of the nonsupersymmetric version of the model and the fine-tuning of the initial conditions of the fields leading to sufficient inflation to account for the standard cosmological problems. They are investigated by studying the exact two-fields dynamics instead of assuming slow-roll. When the field values are restricted to be less than the reduced Planck mass, a non-negligible part of the initial condition space (around 15% depending on potential parameters) leads to successful inflation. Most of it is located outside the usual inflationary valley and organized in continuous patterns instead of being isolated as previously found. Their existence is explained and their properties are studied. This shows that no excessive fine-tuning is required for successful hybrid inflation. Moreover, by extending the initial condition space to Planckian-like or super-Planckian values, inflation becomes generically sufficiently long and can produce a red-tilted scalar power spectrum due to slow-roll violations. The robustness of these properties is confirmed by conducting our analysis on three other models of hybrid-type inflation in various framework: 'smooth' and 'shifted' inflation in SUSY and SUGRA, and 'radion assisted' gauge inflation. A high percentage of successful inflation for smooth hybrid inflation (up to 80%) is observed.

Knowledge-guided golf course detection using a convolutional neural network fine-tuned on temporally augmented data

Science.gov (United States)

Chen, Jingbo; Wang, Chengyi; Yue, Anzhi; Chen, Jiansheng; He, Dongxu; Zhang, Xiuyan

2017-10-01

The tremendous success of deep learning models such as convolutional neural networks (CNNs) in computer vision provides a method for similar problems in the field of remote sensing. Although research on repurposing pretrained CNN to remote sensing tasks is emerging, the scarcity of labeled samples and the complexity of remote sensing imagery still pose challenges. We developed a knowledge-guided golf course detection approach using a CNN fine-tuned on temporally augmented data. The proposed approach is a combination of knowledge-driven region proposal, data-driven detection based on CNN, and knowledge-driven postprocessing. To confront data complexity, knowledge-derived cooccurrence, composition, and area-based rules are applied sequentially to propose candidate golf regions. To confront sample scarcity, we employed data augmentation in the temporal domain, which extracts samples from multitemporal images. The augmented samples were then used to fine-tune a pretrained CNN for golf detection. Finally, commission error was further suppressed by postprocessing. Experiments conducted on GF-1 imagery prove the effectiveness of the proposed approach.

Myosin phosphatase Fine-tunes Zebrafish Motoneuron Position during Axonogenesis.

Directory of Open Access Journals (Sweden)

Juliane Bremer

2016-11-01

Full Text Available During embryogenesis the spinal cord shifts position along the anterior-posterior axis relative to adjacent tissues. How motor neurons whose cell bodies are located in the spinal cord while their axons reside in adjacent tissues compensate for such tissue shift is not well understood. Using live cell imaging in zebrafish, we show that as motor axons exit from the spinal cord and extend through extracellular matrix produced by adjacent notochord cells, these cells shift several cell diameters caudally. Despite this pronounced shift, individual motoneuron cell bodies stay aligned with their extending axons. We find that this alignment requires myosin phosphatase activity within motoneurons, and that mutations in the myosin phosphatase subunit mypt1 increase myosin phosphorylation causing a displacement between motoneuron cell bodies and their axons. Thus, we demonstrate that spinal motoneurons fine-tune their position during axonogenesis and we identify the myosin II regulatory network as a key regulator.

Dynamic Tuning of Plasmon-Exciton Coupling in Arrays of Nanodisk-J-aggregate Complexes

KAUST Repository

Zheng, Yue Bing

2010-07-21

Figure Presented Dynamic tuning of plasmon-exclton resonant coupling in arrays of nanodisk-J-aggregate complexes is demonstrated. The angle-resolved spectra of an array of bare gold nanodisks exhibit continuous shifting of localized surface plasmon resonance. This characteristic enables the production of real-time, controllable spectral overlap between molecular resonance and plasmóme resonance. The resonant interaction strength as a function of spectral overlap is explored and the coupling strength changes with the incident angle of a probe light, in accord with simulations based on coupled dipóle approximation method. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fine-tuning by strigolactones of root response to low phosphate.

Science.gov (United States)

Kapulnik, Yoram; Koltai, Hinanit

2016-03-01

Strigolactones are plant hormones that regulate the development of different plant parts. In the shoot, they regulate axillary bud outgrowth and in the root, root architecture and root-hair length and density. Strigolactones are also involved with communication in the rhizosphere, including enhancement of hyphal branching of arbuscular mycorrhizal fungi. Here we present the role and activity of strigolactones under conditions of phosphate deprivation. Under these conditions, their levels of biosynthesis and exudation increase, leading to changes in shoot and root development. At least for the latter, these changes are likely to be associated with alterations in auxin transport and sensitivity. On the other hand, strigolactones may positively affect plant-mycorrhiza interactions and thereby promote phosphate acquisition by the plant. Strigolactones may be a way for plants to fine-tune their growth pattern under phosphate deprivation. © 2015 Institute of Botany, Chinese Academy of Sciences.

Pentagone internalises glypicans to fine-tune multiple signalling pathways

Science.gov (United States)

Norman, Mark; Vuilleumier, Robin; Springhorn, Alexander; Gawlik, Jennifer; Pyrowolakis, George

2016-01-01

Tight regulation of signalling activity is crucial for proper tissue patterning and growth. Here we investigate the function of Pentagone (Pent), a secreted protein that acts in a regulatory feedback during establishment and maintenance of BMP/Dpp morphogen signalling during Drosophila wing development. We show that Pent internalises the Dpp co-receptors, the glypicans Dally and Dally-like protein (Dlp), and propose that this internalisation is important in the establishment of a long range Dpp gradient. Pent-induced endocytosis and degradation of glypicans requires dynamin- and Rab5, but not clathrin or active BMP signalling. Thus, Pent modifies the ability of cells to trap and transduce BMP by fine-tuning the levels of the BMP reception system at the plasma membrane. In addition, and in accordance with the role of glypicans in multiple signalling pathways, we establish a requirement of Pent for Wg signalling. Our data propose a novel mechanism by which morphogen signalling is regulated. DOI: http://dx.doi.org/10.7554/eLife.13301.001 PMID:27269283

Theory and experiment of Fourier-Bessel field calculation and tuning of a pulsed wave annular array

DEFF Research Database (Denmark)

Fox, Paul D.; Jiqi, Cheng; Jian-yu, Lu

2003-01-01

A one-dimensional (1D) Fourier-Bessel series method for computing and tuning (beamforming) the linear lossless field of flat pulsed wave annular arrays is developed and supported with both numerical simulation and experimental verification. The technique represents a new method for modeling and t...

Fine-tuning of electronic properties in donor-acceptor conjugated polymers based on oligothiophenes

Science.gov (United States)

Imae, Ichiro; Sagawa, Hitoshi; Harima, Yutaka

2018-03-01

A novel series of donor-acceptor conjugated polymers having oligothiophenes with well-defined structures were synthesized and their optical, electrochemical, and photovoltaic properties were investigated. It was found that the absorption bands of polymers were red-shifted with increasing number of ethylenedioxy groups added to each oligothiophene unit and that their band edges reached over 1000 nm. The systematical fine-tuning of the electronic properties was achieved using the chemical structures of oligothiophene units. Photovoltaic cells based on polymer/(6,6)-phenyl C61 butyric acid methyl ester (PC61BM) exhibited power conversion efficiencies in the range from 0.004 to 1.10%, reflecting the electronic properties of the polymers.

Frequency Fine-tuning of a Spin-flip Cavity for Antihydrogen Atoms

CERN Document Server

Federmann, S; Mahner, E; Juhasz, B; Widmann, E

2012-01-01

As part of the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) physics program a spin-flip cavity, for measurements of the ground-state hyperfine transition frequency of antihydrogen atoms, is needed. The purpose of the cavity is to excite antihydrogen atoms depending on their polarisation by a microwave field operating at 1.42 GHz. The delicacy of designing such a cavity lies in achieving and maintaining the required properties of this field over a large aperture of 10 cm and for a long period of time (required amplitude stability is 1% over 12 h). This paper presents the frequency fine tuning techniques developed to obtain the desired centre frequency of 1.42GHz with a Q value below 500 as well as the circuit used for the frequency sweep over a bandwidth of 6MHz.

The minimally tuned minimal supersymmetric standard model

International Nuclear Information System (INIS)

Essig, Rouven; Fortin, Jean-Francois

2008-01-01

The regions in the Minimal Supersymmetric Standard Model with the minimal amount of fine-tuning of electroweak symmetry breaking are presented for general messenger scale. No a priori relations among the soft supersymmetry breaking parameters are assumed and fine-tuning is minimized with respect to all the important parameters which affect electroweak symmetry breaking. The superpartner spectra in the minimally tuned region of parameter space are quite distinctive with large stop mixing at the low scale and negative squark soft masses at the high scale. The minimal amount of tuning increases enormously for a Higgs mass beyond roughly 120 GeV

Invariant Set Theory: Violating Measurement Independence without Fine Tuning, Conspiracy, Constraints on Free Will or Retrocausality

Directory of Open Access Journals (Sweden)

Tim Palmer

2015-11-01

Full Text Available Invariant Set (IS theory is a locally causal ontic theory of physics based on the Cosmological Invariant Set postulate that the universe U can be considered a deterministic dynamical system evolving precisely on a (suitably constructed fractal dynamically invariant set in U's state space. IS theory violates the Bell inequalities by violating Measurement Independence. Despite this, IS theory is not fine tuned, is not conspiratorial, does not constrain experimenter free will and does not invoke retrocausality. The reasons behind these claims are discussed in this paper. These arise from properties not found in conventional ontic models: the invariant set has zero measure in its Euclidean embedding space, has Cantor Set structure homeomorphic to the p-adic integers (p>>0 and is non-computable. In particular, it is shown that the p-adic metric encapulates the physics of the Cosmological Invariant Set postulate, and provides the technical means to demonstrate no fine tuning or conspiracy. Quantum theory can be viewed as the singular limit of IS theory when when p is set equal to infinity. Since it is based around a top-down constraint from cosmology, IS theory suggests that gravitational and quantum physics will be unified by a gravitational theory of the quantum, rather than a quantum theory of gravity. Some implications arising from such a perspective are discussed.

Active thermal fine laser tuning in a broad spectral range and optical properties of cholesteric liquid crystal.

Science.gov (United States)

Jeong, Mi-Yun; Kwak, Keumcheol

2016-11-20

In this study, we achieved active fine laser tuning in a broad spectral range with dye-doped cholesteric liquid crystal wedge-type cells through temperature control. The spatial pitch gradient of each position of the wedge cell at room temperature was almost maintained after developing a temperature gradient. To achieve the maximum tuning range, the chiral dopant concentration, thickness, thickness gradient, and temperature gradient on the wedge cell should be matched properly. In order to understand the laser tuning mechanism for temperature change, we studied the temperature dependence of optical properties of the photonic bandgap of cholesteric liquid crystals. In our cholesteric liquid crystal samples, when temperature was increased, photonic bandgaps were shifted toward blue, while the width of the photonic bandgap was decreased, regardless of whether the helicity was left-handed or right-handed. This is mainly due to the combination of decreased refractive indices, higher molecular anisotropy of chiral molecules, and increased chiral molecular solubility. We envisage that this kind of study will prove useful in the development of practical active tunable CLC laser devices.

Phospho-Pon Binding-Mediated Fine-Tuning of Plk1 Activity.

Science.gov (United States)

Zhu, Kang; Shan, Zelin; Zhang, Lu; Wen, Wenyu

2016-07-06

In Drosophila neuroblasts (NBs), the asymmetrical localization and segregation of the cell-fate determinant Numb are regulated by its adaptor Partner of Numb (Pon) and the cell-cycle kinase Polo. Polo phosphorylates the Pon localization domain, thus leading to its basal distribution together with Numb, albeit through an unclear mechanism. Here, we find that Cdk1 phosphorylates Pon at Thr63, thus creating a docking site for the Polo-box domain (PBD) of Polo-like kinase 1 (Plk1). The crystal structure of the Plk1 PBD/phospho-Pon complex reveals that two phospho-Pon bound PBDs associate to form a dimer of dimers. We provide evidence that phospho-Pon binding-induced PBD dimerization relieves the autoinhibition of Plk1. Moreover, we demonstrate that the priming Cdk1 phosphorylation of Pon is important for sequential Plk1 phosphorylation. Our results not only provide structural insight into how phosphoprotein binding activates Plk1 but also suggest that binding to different phosphoproteins might mediate the fine-tuning of Plk1 activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fine-Tuning on the Effective Patch Radius Expression of the Circular Microstrip Patch Antennas

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A. E. Yilmaz

2010-09-01

Full Text Available In this study, the effective patch radius expression for the circular microstrip antennas is improved by means of several manipulations. Departing from previously proposed equations in the literature, one of the most accurate equations is picked up, and this equation is fine-tuned by means of Particle Swarm Optimization technique. Throughout the study, impacts of other parameters (such as the definition of the fitness/objective function, the degree-of-freedom in the proposed effective patch radius expression, the number of measured resonant frequency values are observed in a controlled manner. Finally, about 3% additional improvement is achieved over a very accurate formula, which was proposed earlier.

High-resolution dynamic pressure sensor array based on piezo-phototronic effect tuned photoluminescence imaging.

Science.gov (United States)

Peng, Mingzeng; Li, Zhou; Liu, Caihong; Zheng, Qiang; Shi, Xieqing; Song, Ming; Zhang, Yang; Du, Shiyu; Zhai, Junyi; Wang, Zhong Lin

2015-03-24

A high-resolution dynamic tactile/pressure display is indispensable to the comprehensive perception of force/mechanical stimulations such as electronic skin, biomechanical imaging/analysis, or personalized signatures. Here, we present a dynamic pressure sensor array based on pressure/strain tuned photoluminescence imaging without the need for electricity. Each sensor is a nanopillar that consists of InGaN/GaN multiple quantum wells. Its photoluminescence intensity can be modulated dramatically and linearly by small strain (0-0.15%) owing to the piezo-phototronic effect. The sensor array has a high pixel density of 6350 dpi and exceptional small standard deviation of photoluminescence. High-quality tactile/pressure sensing distribution can be real-time recorded by parallel photoluminescence imaging without any cross-talk. The sensor array can be inexpensively fabricated over large areas by semiconductor product lines. The proposed dynamic all-optical pressure imaging with excellent resolution, high sensitivity, good uniformity, and ultrafast response time offers a suitable way for smart sensing, micro/nano-opto-electromechanical systems.

Tuning temperature and size of hot spots and hot-spot arrays.

Science.gov (United States)

Saïdi, Elika; Babinet, Nicolas; Lalouat, Loïc; Lesueur, Jérôme; Aigouy, Lionel; Volz, Sébastian; Labéguerie-Egéa, Jessica; Mortier, Michel

2011-01-17

By using scanning thermal microscopy, it is shown that nanoscale constrictions in metallic microwires deposited on an oxidized silicon substrate can be tuned in terms of temperature and confinement size. High-resolution temperature maps indeed show that submicrometer hot spots and hot-spot arrays are obtained when the SiO(2) layer thickness decreases below 100 nm. When the SiO(2) thickness becomes larger, heat is less confined in the vicinity of the constrictions and laterally spreads all along the microwire. These results are in good agreement with numerical simulations, which provide dependences between silica-layer thickness and nanodot shape and temperature. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fine tuning a well-oiled machine: Influence of NK1.1 and NKG2D on NKT cell development and function.

Science.gov (United States)

Joshi, Sunil K; Lang, Mark L

2013-10-01

Natural killer T cells (NKT) represent a group of CD1d-restricted T-lineage cells that provide a functional interface between innate and adaptive immune responses in infectious disease, cancer, allergy and autoimmunity. There have been remarkable advances in understanding the molecular events that underpin NKT development in the thymus and in the complex array of functions in the periphery. Most functional studies have focused on activation of T cell antigen receptors expressed by NKT cells and their responses to CD1d presentation of glycolipid and related antigens. Receiving less attention has been several molecules that are hallmarks of Natural Killer (NK) cells, but nonetheless expressed by NKT cells. These include several activating and inhibitory receptors that may fine-tune NKT development and survival, as well as activation via antigen receptors. Herein, we review the possible roles of the NK1.1 and NKG2D receptors in regulating development and function of NKT cells in health and disease. We suggest that pharmacological alteration of NKT activity should consider the potential complexities commensurate with NK1.1 and NKG2D expression. Published by Elsevier B.V.

Fine-tuning of defensive behaviors in the dorsal periaqueductal gray by atypical neurotransmitters

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M.V. Fogaça

2012-04-01

Full Text Available This paper presents an up-to-date review of the evidence indicating that atypical neurotransmitters such as nitric oxide (NO and endocannabinoids (eCBs play an important role in the regulation of aversive responses in the periaqueductal gray (PAG. Among the results supporting this role, several studies have shown that inhibitors of neuronal NO synthase or cannabinoid receptor type 1 (CB1 receptor agonists cause clear anxiolytic responses when injected into this region. The nitrergic and eCB systems can regulate the activity of classical neurotransmitters such as glutamate and γ-aminobutyric acid (GABA that control PAG activity. We propose that they exert a ‘fine-tuning’ regulatory control of defensive responses in this area. This control, however, is probably complex, which may explain the usually bell-shaped dose-response curves observed with drugs that act on NO- or CB1-mediated neurotransmission. Even if the mechanisms responsible for this complex interaction are still poorly understood, they are beginning to be recognized. For example, activation of transient receptor potential vanilloid type-1 channel (TRPV1 receptors by anandamide seems to counteract the anxiolytic effects induced by CB1 receptor activation caused by this compound. Further studies, however, are needed to identify other mechanisms responsible for this fine-tuning effect.

Antenna Arrays and Automotive Applications

CERN Document Server

Rabinovich, Victor

2013-01-01

This book throws a lifeline to designers wading through mounds of antenna array patents looking for the most suitable systems for their projects. Drastically reducing the research time required to locate solutions to the latest challenges in automotive communications, it sorts and systematizes material on cutting-edge antenna arrays that feature multi-element communication systems with enormous potential for the automotive industry. These new systems promise to make driving safer and more efficient, opening up myriad applications, including vehicle-to-vehicle traffic that prevents collisions, automatic toll collection, vehicle location and fine-tuning for cruise control systems. This book’s exhaustive coverage begins with currently deployed systems, frequency ranges and key parameters. It proceeds to examine system geometry, analog and digital beam steering technology (including "smart" beams formed in noisy environments), maximizing signal-to-noise ratios, miniaturization, and base station technology that ...

Enhancement of impact strength of poly (methyl methacrylate) with surface fine-tuned nano-silica

International Nuclear Information System (INIS)

Wen, Bin; Dong, Yixiao; Wu, Lili; Long, Chao; Zhang, Chaocan

2015-01-01

Highly dispersible nanoparticles in organic solvent always receive wide interests due to their compatibility with polymer materials. This paper reported a kind of isopropanol alcohol silica dispersion which obtained using a method of azeotropic distillation. The isopropanol alcohol dispersed silica (IPADS) were treated with coupling agents to fine-tune their surface properties. Polymethyl methacrylate (PMMA) was then used as a research object to test the compatibility between IPADS and polymer. UV-vis spectra indicate that IPADS would reach its high compatibility with PMMA if coupling with trimethoxypropylsilane (PTMS). Followed experiments on PMMA proved that the high compatibility can prominently enhance the impact strength about 30%. The results may provide reference both for nano-silica modification and better understanding of nano-enhanced materials. (paper)

Enhancement of impact strength of poly (methyl methacrylate) with surface fine-tuned nano-silica

Science.gov (United States)

Wen, Bin; Dong, Yixiao; Wu, Lili; Long, Chao; Zhang, Chaocan

2015-07-01

Highly dispersible nanoparticles in organic solvent always receive wide interests due to their compatibility with polymer materials. This paper reported a kind of isopropanol alcohol silica dispersion which obtained using a method of azeotropic distillation. The isopropanol alcohol dispersed silica (IPADS) were treated with coupling agents to fine-tune their surface properties. Polymethyl methacrylate (PMMA) was then used as a research object to test the compatibility between IPADS and polymer. UV-vis spectra indicate that IPADS would reach its high compatibility with PMMA if coupling with trimethoxypropylsilane (PTMS). Followed experiments on PMMA proved that the high compatibility can prominently enhance the impact strength about 30%. The results may provide reference both for nano-silica modification and better understanding of nano-enhanced materials.

Au@Ag Core-Shell Nanocubes with Finely Tuned and Well-Controlled Sizes, Shell Thicknesses, and Optical Properties

OpenAIRE

Ma, Yanyun; Li, Weiyang; Cho, Eun Chul; Li, Zhiyuan; Yu, Taekyung; Zeng, Jie; Xie, Zhaoxiong; Xia, Younan

2010-01-01

This paper describes a facile method for generating Au@Ag core-shell nanocubes with edge lengths controllable in the range of 13.4 to 50 nm. The synthesis involved the use of single-crystal, spherical Au nanocrystals of 11 nm in size as the seeds in an aqueous system, with ascorbic acid serving as the reductant and cetyltrimethylammonium chloride (CTAC) as the capping agent. The thickness of the Ag shells could be finely tuned from 1.2 to 20 nm by varying the ratio of AgNO3 precursor to Au se...

Inflation with improved D3-brane potential and the fine tunings associated with the model

International Nuclear Information System (INIS)

Ali, Amna; Sami, M.; Deshamukhya, Atri; Panda, Sudhakar

2011-01-01

We revisit our earlier investigations of the brane-antibrane inflation in a warped deformed conifold background, reported in Phys. Lett. B 674, 131 (2009), where now we include the contributions to the inflation potential arising from imaginary anti-self-dual (IASD) fluxes including the term with irrational scaling dimension discovered recently in arXiv:0912.4268 and arXiv:1001.5028. We observe that these corrections to the effective potential help in relaxing the severe fine tunings associated with the earlier analysis. Required number of e-folds, observational constraint on COBE normalization and low value of the tensor to scalar ratio are achieved which is consistent with WMAP seven years data. (orig.)

Improving Genetic Algorithm with Fine-Tuned Crossover and Scaled Architecture

Directory of Open Access Journals (Sweden)

Ajay Shrestha

2016-01-01

Full Text Available Genetic Algorithm (GA is a metaheuristic used in solving combinatorial optimization problems. Inspired by evolutionary biology, GA uses selection, crossover, and mutation operators to efficiently traverse the solution search space. This paper proposes nature inspired fine-tuning to the crossover operator using the untapped idea of Mitochondrial DNA (mtDNA. mtDNA is a small subset of the overall DNA. It differentiates itself by inheriting entirely from the female, while the rest of the DNA is inherited equally from both parents. This unique characteristic of mtDNA can be an effective mechanism to identify members with similar genes and restrict crossover between them. It can reduce the rate of dilution of diversity and result in delayed convergence. In addition, we scale the well-known Island Model, where instances of GA are run independently and population members exchanged periodically, to a Continental Model. In this model, multiple web services are executed with each web service running an island model. We applied the concept of mtDNA in solving Traveling Salesman Problem and to train Neural Network for function approximation. Our implementation tests show that leveraging these new concepts of mtDNA and Continental Model results in relative improvement of the optimization quality of GA.

Transparently wrap-gated semiconductor nanowire arrays for studies of gate-controlled photoluminescence

Energy Technology Data Exchange (ETDEWEB)

Nylund, Gustav; Storm, Kristian; Torstensson, Henrik; Wallentin, Jesper; Borgström, Magnus T.; Hessman, Dan; Samuelson, Lars [Solid State Physics, Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund (Sweden)

2013-12-04

We present a technique to measure gate-controlled photoluminescence (PL) on arrays of semiconductor nanowire (NW) capacitors using a transparent film of Indium-Tin-Oxide (ITO) wrapping around the nanowires as the gate electrode. By tuning the wrap-gate voltage, it is possible to increase the PL peak intensity of an array of undoped InP NWs by more than an order of magnitude. The fine structure of the PL spectrum reveals three subpeaks whose relative peak intensities change with gate voltage. We interpret this as gate-controlled state-filling of luminescing quantum dot segments formed by zincblende stacking faults in the mainly wurtzite NW crystal structure.

Tuning Parameters in Heuristics by Using Design of Experiments Methods

Science.gov (United States)

Arin, Arif; Rabadi, Ghaith; Unal, Resit

2010-01-01

With the growing complexity of today's large scale problems, it has become more difficult to find optimal solutions by using exact mathematical methods. The need to find near-optimal solutions in an acceptable time frame requires heuristic approaches. In many cases, however, most heuristics have several parameters that need to be "tuned" before they can reach good results. The problem then turns into "finding best parameter setting" for the heuristics to solve the problems efficiently and timely. One-Factor-At-a-Time (OFAT) approach for parameter tuning neglects the interactions between parameters. Design of Experiments (DOE) tools can be instead employed to tune the parameters more effectively. In this paper, we seek the best parameter setting for a Genetic Algorithm (GA) to solve the single machine total weighted tardiness problem in which n jobs must be scheduled on a single machine without preemption, and the objective is to minimize the total weighted tardiness. Benchmark instances for the problem are available in the literature. To fine tune the GA parameters in the most efficient way, we compare multiple DOE models including 2-level (2k ) full factorial design, orthogonal array design, central composite design, D-optimal design and signal-to-noise (SIN) ratios. In each DOE method, a mathematical model is created using regression analysis, and solved to obtain the best parameter setting. After verification runs using the tuned parameter setting, the preliminary results for optimal solutions of multiple instances were found efficiently.

Java performance tuning

CERN Document Server

Shirazi, Jack

2003-01-01

Performance has been an important issue for Java developers ever since the first version hit the streets. Over the years, Java performance has improved dramatically, but tuning is essential to get the best results, especially for J2EE applications. You can never have code that runs too fast. Java Peformance Tuning, 2nd edition provides a comprehensive and indispensable guide to eliminating all types of performance problems. Using many real-life examples to work through the tuning process in detail, JPT shows how tricks such as minimizing object creation and replacing strings with arrays can

Fungal Endophytes as a Metabolic Fine-Tuning Regulator for Wine Grape.

Directory of Open Access Journals (Sweden)

Ming-Zhi Yang

Full Text Available Endophytes proved to exert multiple effects on host plants, including growth promotion, stress resistance. However, whether endophytes have a role in metabolites shaping of grape has not been fully understood. Eight endophytic fungal strains which originally isolated from grapevines were re-inoculated to field-grown grapevines in this study, and their effects on both leaves and berries of grapevines at maturity stage were assessed, with special focused on secondary metabolites and antioxidant activities. High-density inoculation of all these endophytic fungal strains modified the physio-chemical status of grapevine to different degrees. Fungal inoculations promoted the content of reducing sugar (RS, total flavonoids (TF, total phenols (TPh, trans-resveratrol (Res and activities of phenylalanine ammonia-lyase (PAL, in both leaves and berries of grapevine. Inoculation of endophytic fungal strains, CXB-11 (Nigrospora sp. and CXC-13 (Fusarium sp. conferred greater promotion effects in grape metabolic re-shaping, compared to other used fungal strains. Additionally, inoculation of different strains of fungal endophytes led to establish different metabolites patterns of wine grape. The work implies the possibility of using endophytic fungi as fine-tuning regulator to shape the quality and character of wine grape.

Structural control of ultra-fine CoPt nanodot arrays via electrodeposition process

Energy Technology Data Exchange (ETDEWEB)

Wodarz, Siggi [Department of Applied Chemistry, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Hasegawa, Takashi; Ishio, Shunji [Department of Materials Science, Akita University, Akita City 010-8502 (Japan); Homma, Takayuki, E-mail: t.homma@waseda.jp [Department of Applied Chemistry, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

2017-05-15

CoPt nanodot arrays were fabricated by combining electrodeposition and electron beam lithography (EBL) for the use of bit-patterned media (BPM). To achieve precise control of deposition uniformity and coercivity of the CoPt nanodot arrays, their crystal structure and magnetic properties were controlled by controlling the diffusion state of metal ions from the initial deposition stage with the application of bath agitation. Following bath agitation, the composition gradient of the CoPt alloy with thickness was mitigated to have a near-ideal alloy composition of Co:Pt =80:20, which induces epitaxial-like growth from Ru substrate, thus resulting in the improvement of the crystal orientation of the hcp (002) structure from its initial deposition stages. Furthermore, the cross-sectional transmission electron microscope (TEM) analysis of the nanodots deposited with bath agitation showed CoPt growth along its c-axis oriented in the perpendicular direction, having uniform lattice fringes on the hcp (002) plane from the Ru underlayer interface, which is a significant factor to induce perpendicular magnetic anisotropy. Magnetic characterization of the CoPt nanodot arrays showed increase in the perpendicular coercivity and squareness of the hysteresis loops from 2.0 kOe and 0.64 (without agitation) to 4.0 kOe and 0.87 with bath agitation. Based on the detailed characterization of nanodot arrays, the precise crystal structure control of the nanodot arrays with ultra-high recording density by electrochemical process was successfully demonstrated. - Highlights: • Ultra-fine CoPt nanodot arrays were fabricated by electrodeposition. • Crystallinity of hcp (002) was improved with uniform composition formation. • Uniform formation of hcp lattices leads to an increase in the coercivity.

Statistical-Mechanical Analysis of Pre-training and Fine Tuning in Deep Learning

Science.gov (United States)

Ohzeki, Masayuki

2015-03-01

In this paper, we present a statistical-mechanical analysis of deep learning. We elucidate some of the essential components of deep learning — pre-training by unsupervised learning and fine tuning by supervised learning. We formulate the extraction of features from the training data as a margin criterion in a high-dimensional feature-vector space. The self-organized classifier is then supplied with small amounts of labelled data, as in deep learning. Although we employ a simple single-layer perceptron model, rather than directly analyzing a multi-layer neural network, we find a nontrivial phase transition that is dependent on the number of unlabelled data in the generalization error of the resultant classifier. In this sense, we evaluate the efficacy of the unsupervised learning component of deep learning. The analysis is performed by the replica method, which is a sophisticated tool in statistical mechanics. We validate our result in the manner of deep learning, using a simple iterative algorithm to learn the weight vector on the basis of belief propagation.

A Transcriptional Regulatory Mechanism Finely Tunes the Firing of Type VI Secretion System in Response to Bacterial Enemies.

Science.gov (United States)

Lazzaro, Martina; Feldman, Mario F; García Véscovi, Eleonora

2017-08-22

also recently identified as one major component of the gut microbiome in familial Crohn disease dysbiosis. Type VI secretion systems (T6SSs) stand among the array of survival strategies that Serratia displays. They are contractile multiprotein complexes able to deliver toxic effectors directed to kill bacterial species sharing the same niche and, thus, competing for vital resources. Here, we show that Serratia is able to detect and measure the extent of damage generated through T6SS-delivered toxins from neighboring bacteria and responds by transcriptionally adjusting the expression level of its own T6SS machinery to counterattack the rival. This strategy allows Serratia to finely tune the production of costly T6SS devices to maximize the chances of successfully fighting against enemies and minimize energy investment. The knowledge of this novel mechanism provides insight to better understand bacterial interactions and design alternative treatments for polymicrobial infections. Copyright © 2017 Lazzaro et al.

Natural tuning: towards a proof of concept

Science.gov (United States)

Dubovsky, Sergei; Gorbenko, Victor; Mirbabayi, Mehrdad

2013-09-01

The cosmological constant problem and the absence of new natural physics at the electroweak scale, if confirmed by the LHC, may either indicate that the nature is fine-tuned or that a refined notion of naturalness is required. We construct a family of toy UV complete quantum theories providing a proof of concept for the second possibility. Low energy physics is described by a tuned effective field theory, which exhibits relevant interactions not protected by any symmetries and separated by an arbitrary large mass gap from the new "gravitational" physics, represented by a set of irrelevant operators. Nevertheless, the only available language to describe dynamics at all energy scales does not require any fine-tuning. The interesting novel feature of this construction is that UV physics is not described by a fixed point, but rather exhibits asymptotic fragility. Observation of additional unprotected scalars at the LHC would be a smoking gun for this scenario. Natural tuning also favors TeV scale unification.

Fine tuning of the lactate and diacetyl production through promoter engineering in Lactococcus lactis.

Directory of Open Access Journals (Sweden)

Tingting Guo

Full Text Available Lactococcus lactis is a well-studied bacterium widely used in dairy fermentation and capable of producing metabolites with organoleptic and nutritional characteristics. For fine tuning of the distribution of glycolytic flux at the pyruvate branch from lactate to diacetyl and balancing the production of the two metabolites under aerobic conditions, a constitutive promoter library was constructed by randomizing the promoter sequence of the H(2O-forming NADH oxidase gene in L. lactis. The library consisted of 30 promoters covering a wide range of activities from 7,000 to 380,000 relative fluorescence units using a green fluorescent protein as reporter. Eleven typical promoters of the library were selected for the constitutive expression of the H(2O-forming NADH oxidase gene in L. lactis, and the NADH oxidase activity increased from 9.43 to 58.17-fold of the wild-type strain in small steps of activity change under aerobic conditions. Meanwhile, the lactate yield decreased from 21.15 ± 0.08 mM to 9.94 ± 0.07 mM, and the corresponding diacetyl production increased from 1.07 ± 0.03 mM to 4.16 ± 0.06 mM with the intracellular NADH/NAD(+ ratios varying from 0.711 ± 0.005 to 0.383 ± 0.003. The results indicated that the reduced pyruvate to lactate flux was rerouted to the diacetyl with an almost linear flux variation via altered NADH/NAD(+ ratios. Therefore, we provided a novel strategy to precisely control the pyruvate distribution for fine tuning of the lactate and diacetyl production through promoter engineering in L. lactis. Interestingly, the increased H(2O-forming NADH oxidase activity led to 76.95% lower H(2O(2 concentration in the recombinant strain than that of the wild-type strain after 24 h of aerated cultivation. The viable cells were significantly elevated by four orders of magnitude within 28 days of storage at 4°C, suggesting that the increased enzyme activity could eliminate H(2O(2 accumulation and prolong cell survival.

Efficient receiver tuning using differential evolution strategies

Science.gov (United States)

Wheeler, Caleb H.; Toland, Trevor G.

2016-08-01

Differential evolution (DE) is a powerful and computationally inexpensive optimization strategy that can be used to search an entire parameter space or to converge quickly on a solution. The Kilopixel Array Pathfinder Project (KAPPa) is a heterodyne receiver system delivering 5 GHz of instantaneous bandwidth in the tuning range of 645-695 GHz. The fully automated KAPPa receiver test system finds optimal receiver tuning using performance feedback and DE. We present an adaptation of DE for use in rapid receiver characterization. The KAPPa DE algorithm is written in Python 2.7 and is fully integrated with the KAPPa instrument control, data processing, and visualization code. KAPPa develops the technologies needed to realize heterodyne focal plane arrays containing 1000 pixels. Finding optimal receiver tuning by investigating large parameter spaces is one of many challenges facing the characterization phase of KAPPa. This is a difficult task via by-hand techniques. Characterizing or tuning in an automated fashion without need for human intervention is desirable for future large scale arrays. While many optimization strategies exist, DE is ideal for time and performance constraints because it can be set to converge to a solution rapidly with minimal computational overhead. We discuss how DE is utilized in the KAPPa system and discuss its performance and look toward the future of 1000 pixel array receivers and consider how the KAPPa DE system might be applied.

Fine frequency tuning of the PHOENIX charge breeder used as a probe for ECRIS plasmas

International Nuclear Information System (INIS)

Lamy, T.; Angot, J.; Melanie, M.J.; Medard, J.; Sortais, P.; Thuillier, T.; Galata, A.; Koivisto, Hannu; Tarvainen, Olli

2012-01-01

Fine frequency tuning of ECR ion sources is a main issue to optimize the production of multiply charged ion beams. The PHOENIX charge breeder operation has been tested in the range 13.75 - 14.5 GHz with an HF power of about 400 W. The effect of this tuning is analyzed by measuring the multi-ionization efficiency obtained for various characterized injected 1+ ion beams (produced by the 2.45 GHz COMIC source). The 1+/n+ method includes the capture and the multi ionization processes of the 1+ beam and may be considered as a plasma probe. The n+ spectra obtained could be considered, in first approach, as an image of the plasma of the charge breeder. However, in certain conditions it has been observed that the injection of a few hundreds of nA of 1+ ions (i.e.: Xe+) in the plasma of the charge breeder, is able to destroy the charge state distribution of the support gas (i.e.: up to 40 % of O 6+ and O 7+ disappears). The study of this phenomenon will be presented along with plasma potential measurements for various charge states. This study may help to understand the creation (or destruction) of highly charged ions inside an ECRIS. The paper is followed by the slides of the presentation. (authors)

Fine-tuning of the spectral collection efficiency in multilayer junctions

International Nuclear Information System (INIS)

Fernandes, M.; Fantoni, A.; Louro, P.; Lavareda, G.; Carvalho, N.; Schwarz, R.; Vieira, M.

2006-01-01

a-SiC:H/a-Si:H p-i-n/p-i-n tandem cells with different i-layer thickness have been produced by PECVD and tested for a proper fine-tuning of the spectral collection efficiency. The tandem structure takes advantage on the radiation wavelength selectivity due to the different light penetration depth inside the a-Si:H and a-SiC:H absorbers. The thickness and the absorption coefficient of the front p-i-n cell were optimized for blue collection and red transmittance and the thickness of the back one adjusted to achieve full absorption in the green and high collection in the red spectral ranges. Preliminary results show that device optimization for red detection can be obtained by reducing the thickness of the internal recombination junction while by increasing the intrinsic layer of the bottom a-Si:H cell, a better detection of the green color under appropriated applied voltages is foreseen. The physics behind the device functioning is explained through a numerical simulation of the internal electrical configuration of the device in dark and under different wavelength irradiations. Considerations about conduction band offsets, electrical field profiles and inversion layers will be taken into account to explain the optical and voltage bias dependence of the spectral response. Experimental results about the spectral collection efficiency are presented and discussed from the point of view of the color sensor applications

Fine-tuning the onset of myogenesis by homeobox proteins that interact with the Myf5 limb enhancer

Directory of Open Access Journals (Sweden)

Philippe Daubas

2015-12-01

Full Text Available Skeletal myogenesis in vertebrates is initiated at different sites of skeletal muscle formation during development, by activation of specific control elements of the myogenic regulatory genes. In the mouse embryo, Myf5 is the first myogenic determination gene to be expressed and its spatiotemporal regulation requires multiple enhancer sequences, extending over 120 kb upstream of the Mrf4-Myf5 locus. An enhancer, located at −57/−58 kb from Myf5, is responsible for its activation in myogenic cells derived from the hypaxial domain of the somite, that will form limb muscles. Pax3 and Six1/4 transcription factors are essential activators of this enhancer, acting on a 145-bp core element. Myogenic progenitor cells that will form the future muscle masses of the limbs express the factors necessary for Myf5 activation when they delaminate from the hypaxial dermomyotome and migrate into the forelimb bud, however they do not activate Myf5 and the myogenic programme until they have populated the prospective muscle masses. We show that Msx1 and Meox2 homeodomain-containing transcription factors bind in vitro and in vivo to specific sites in the 145-bp element, and are implicated in fine-tuning activation of Myf5 in the forelimb. Msx1, when bound between Pax and Six sites, prevents the binding of these key activators, thus inhibiting transcription of Myf5 and consequent premature myogenic differentiation. Meox2 is required for Myf5 activation at the onset of myogenesis via direct binding to other homeodomain sites in this sequence. Thus, these homeodomain factors, acting in addition to Pax3 and Six1/4, fine-tune the entry of progenitor cells into myogenesis at early stages of forelimb development.

Fine-tuning the onset of myogenesis by homeobox proteins that interact with the Myf5 limb enhancer

Science.gov (United States)

Daubas, Philippe; Duval, Nathalie; Bajard, Lola; Langa Vives, Francina; Robert, Benoît; Mankoo, Baljinder S.; Buckingham, Margaret

2015-01-01

ABSTRACT Skeletal myogenesis in vertebrates is initiated at different sites of skeletal muscle formation during development, by activation of specific control elements of the myogenic regulatory genes. In the mouse embryo, Myf5 is the first myogenic determination gene to be expressed and its spatiotemporal regulation requires multiple enhancer sequences, extending over 120 kb upstream of the Mrf4-Myf5 locus. An enhancer, located at −57/−58 kb from Myf5, is responsible for its activation in myogenic cells derived from the hypaxial domain of the somite, that will form limb muscles. Pax3 and Six1/4 transcription factors are essential activators of this enhancer, acting on a 145-bp core element. Myogenic progenitor cells that will form the future muscle masses of the limbs express the factors necessary for Myf5 activation when they delaminate from the hypaxial dermomyotome and migrate into the forelimb bud, however they do not activate Myf5 and the myogenic programme until they have populated the prospective muscle masses. We show that Msx1 and Meox2 homeodomain-containing transcription factors bind in vitro and in vivo to specific sites in the 145-bp element, and are implicated in fine-tuning activation of Myf5 in the forelimb. Msx1, when bound between Pax and Six sites, prevents the binding of these key activators, thus inhibiting transcription of Myf5 and consequent premature myogenic differentiation. Meox2 is required for Myf5 activation at the onset of myogenesis via direct binding to other homeodomain sites in this sequence. Thus, these homeodomain factors, acting in addition to Pax3 and Six1/4, fine-tune the entry of progenitor cells into myogenesis at early stages of forelimb development. PMID:26538636

Tuning Piezo ion channels to detect molecular-scale movements relevant for fine touch

Science.gov (United States)

Poole, Kate; Herget, Regina; Lapatsina, Liudmila; Ngo, Ha-Duong; Lewin, Gary R.

2014-01-01

In sensory neurons, mechanotransduction is sensitive, fast and requires mechanosensitive ion channels. Here we develop a new method to directly monitor mechanotransduction at defined regions of the cell-substrate interface. We show that molecular-scale (~13 nm) displacements are sufficient to gate mechanosensitive currents in mouse touch receptors. Using neurons from knockout mice, we show that displacement thresholds increase by one order of magnitude in the absence of stomatin-like protein 3 (STOML3). Piezo1 is the founding member of a class of mammalian stretch-activated ion channels, and we show that STOML3, but not other stomatin-domain proteins, brings the activation threshold for Piezo1 and Piezo2 currents down to ~10 nm. Structure–function experiments localize the Piezo modulatory activity of STOML3 to the stomatin domain, and higher-order scaffolds are a prerequisite for function. STOML3 is the first potent modulator of Piezo channels that tunes the sensitivity of mechanically gated channels to detect molecular-scale stimuli relevant for fine touch. PMID:24662763

Bottom-Up Nanofabrication of Supported Noble Metal Alloy Nanoparticle Arrays for Plasmonics

DEFF Research Database (Denmark)

Nugroho, Ferry A. A.; Iandolo, Beniamino; Wagner, Jakob Birkedal

2016-01-01

Mixing different elements at the nanoscale to obtain alloy nanostructures with fine-tuned physical and chemical properties offers appealing opportunities for nanotechnology and nanoscience. However, despite widespread successful application of alloy nanoparticles made by colloidal synthesis...... in heterogeneous catalysis, nanoalloy systems have been used very rarely in solid-state devices and nanoplasmonics-related applications. One reason is that such applications require integration in arrays on a surface with compelling demands on nanoparticle arrangement, uniformity in surface coverage......, and optimization of the surface density. These cannot be fulfilled even using state-of-the-art self -assembly strategies of colloids. As a solution, we present here a generic bottom-up nanolithography-compatible fabrication approach for large-area arrays of alloy nanoparticles on surfaces. To illustrate...

Using membrane composition to fine-tune the pKa of an optical liposome pH sensor.

Science.gov (United States)

Clear, Kasey J; Virga, Katelyn; Gray, Lawrence; Smith, Bradley D

2016-04-14

Liposomes containing membrane-anchored pH-sensitive optical probes are valuable sensors for monitoring pH in various biomedical samples. The dynamic range of the sensor is maximized when the probe p K a is close to the expected sample pH. While some biomedical samples are close to neutral pH there are several circumstances where the pH is 1 or 2 units lower. Thus, there is a need to fine-tune the probe p K a in a predictable way. This investigation examined two lipid-conjugated optical probes, each with appended deep-red cyanine dyes containing indoline nitrogen atoms that are protonated in acid. The presence of anionic phospholipids in the liposomes stabilized the protonated probes and increased the probe p K a values by sensor for optimal pH sensing performance.

Mechanisms of input and output synaptic specificity: finding partners, building synapses, and fine-tuning communication.

Science.gov (United States)

Rawson, Randi L; Martin, E Anne; Williams, Megan E

2017-08-01

For most neurons to function properly, they need to develop synaptic specificity. This requires finding specific partner neurons, building the correct types of synapses, and fine-tuning these synapses in response to neural activity. Synaptic specificity is common at both a neuron's input and output synapses, whereby unique synapses are built depending on the partnering neuron. Neuroscientists have long appreciated the remarkable specificity of neural circuits but identifying molecular mechanisms mediating synaptic specificity has only recently accelerated. Here, we focus on recent progress in understanding input and output synaptic specificity in the mammalian brain. We review newly identified circuit examples for both and the latest research identifying molecular mediators including Kirrel3, FGFs, and DGLα. Lastly, we expect the pace of research on input and output specificity to continue to accelerate with the advent of new technologies in genomics, microscopy, and proteomics. Copyright © 2017 Elsevier Ltd. All rights reserved.

An optimal tuning strategy for tidal turbines

Science.gov (United States)

2016-01-01

Tuning wind and tidal turbines is critical to maximizing their power output. Adopting a wind turbine tuning strategy of maximizing the output at any given time is shown to be an extremely poor strategy for large arrays of tidal turbines in channels. This ‘impatient-tuning strategy’ results in far lower power output, much higher structural loads and greater environmental impacts due to flow reduction than an existing ‘patient-tuning strategy’ which maximizes the power output averaged over the tidal cycle. This paper presents a ‘smart patient tuning strategy’, which can increase array output by up to 35% over the existing strategy. This smart strategy forgoes some power generation early in the half tidal cycle in order to allow stronger flows to develop later in the cycle. It extracts enough power from these stronger flows to produce more power from the cycle as a whole than the existing strategy. Surprisingly, the smart strategy can often extract more power without increasing maximum structural loads on the turbines, while also maintaining stronger flows along the channel. This paper also shows that, counterintuitively, for some tuning strategies imposing a cap on turbine power output to limit loads can increase a turbine’s average power output. PMID:27956870

An optimal tuning strategy for tidal turbines.

Science.gov (United States)

Vennell, Ross

2016-11-01

Tuning wind and tidal turbines is critical to maximizing their power output. Adopting a wind turbine tuning strategy of maximizing the output at any given time is shown to be an extremely poor strategy for large arrays of tidal turbines in channels. This 'impatient-tuning strategy' results in far lower power output, much higher structural loads and greater environmental impacts due to flow reduction than an existing 'patient-tuning strategy' which maximizes the power output averaged over the tidal cycle. This paper presents a 'smart patient tuning strategy', which can increase array output by up to 35% over the existing strategy. This smart strategy forgoes some power generation early in the half tidal cycle in order to allow stronger flows to develop later in the cycle. It extracts enough power from these stronger flows to produce more power from the cycle as a whole than the existing strategy. Surprisingly, the smart strategy can often extract more power without increasing maximum structural loads on the turbines, while also maintaining stronger flows along the channel. This paper also shows that, counterintuitively, for some tuning strategies imposing a cap on turbine power output to limit loads can increase a turbine's average power output.

Fine-tuning the feature size of nanoporous silver

NARCIS (Netherlands)

Detsi, Eric; Vukovic, Zorica; Punzhin, Sergey; Bronsveld, Paul M.; Onck, Patrick R.; De Hosson, Jeff Th M.

2012-01-01

We show that the characteristic ligament size of nanoporous Ag synthesized by chemical dissolution of Al from Ag-Al alloys can be tuned from the current submicrometer size (similar to 100-500 nm) down to a much smaller length scale (similar to 30-60 nm). This is achieved by suppressing the formation

Fine-Tuning the Wall Thickness of Ordered Mesoporous Graphene by Exploiting Ligand Exchange of Colloidal Nanocrystals

Directory of Open Access Journals (Sweden)

Dandan Han

2017-12-01

Full Text Available Because of their unique physical properties, three-dimensional (3D graphene has attracted enormous attention over the past years. However, it is still a challenge to precisely control the layer thickness of 3D graphene. Here, we report a novel strategy to rationally adjust the wall thickness of ordered mesoporous graphene (OMG. By taking advantage of ligand exchange capability of colloidal Fe3O4 nanocrystals, we are able to fine-tune the wall thickness of OMG from 2 to 6 layers of graphene. When evaluated as electrocatalyst for oxygen reduction reaction upon S and N doping, the 4-layer OMG is found to show better catalytic performance compared with their 2- and 6-layer counterparts, which we attribute to the enhanced exposure of active sites arising from the thin wall thickness and high surface area.

Fine-tuning the ubiquitin code at DNA double-strand breaks: deubiquitinating enzymes at work

Directory of Open Access Journals (Sweden)

Elisabetta eCitterio

2015-09-01

Full Text Available Ubiquitination is a reversible protein modification broadly implicated in cellular functions. Signaling processes mediated by ubiquitin are crucial for the cellular response to DNA double-strand breaks (DSBs, one of the most dangerous types of DNA lesions. In particular, the DSB response critically relies on active ubiquitination by the RNF8 and RNF168 ubiquitin ligases at the chromatin, which is essential for proper DSB signaling and repair. How this pathway is fine-tuned and what the functional consequences are of its deregulation for genome integrity and tissue homeostasis are subject of intense investigation. One important regulatory mechanism is by reversal of substrate ubiquitination through the activity of specific deubiquitinating enzymes (DUBs, as supported by the implication of a growing number of DUBs in DNA damage response (DDR processes. Here, we discuss the current knowledge of how ubiquitin-mediated signaling at DSBs is controlled by deubiquitinating enzymes, with main focus on DUBs targeting histone H2A and on their recent implication in stem cell biology and cancer.

The BBX subfamily IV: additional cogs and sprockets to fine-tune light-dependent development.

Science.gov (United States)

Sarmiento, Felipe

2013-04-01

Plants depend on light during all phases of its life cycle, and have evolved a complex signaling network to constantly monitor its surroundings. Photomorphogenesis, a process during which the plant reprograms itself in order to dwell life in presence of light is one of the most studied phenomena in plants. Recent mutant analyses using model plant Arabidopsis thaliana and protein interaction assays have unraveled a new set of players, an 8-member subfamily of B-box proteins, known as BBX subfamily IV. For the members of this subfamily, positive (BBX21, BBX22) as well as negative (BBX24) functions have been described for its members, showing a strong association to two major players of the photomorphogenic cascade, HY5 and COP1. The roles of these new BBX regulators are not restricted to photomorphogenesis, but also have functions in other facets of light-dependent development. Therefore this newly identified set of regulators has opened up new insights into the understanding of the fine-tuning of this complex process.

Fine-tuning the Wall Thickness of Ordered Mesoporous Graphene by Exploiting Ligand Exchange of Colloidal Nanocrystals

Science.gov (United States)

Han, Dandan; Yan, Yancui; Wei, Jishi; Wang, Biwei; Li, Tongtao; Guo, Guannan; Yang, Dong; Xie, Songhai; Dong, Angang

2017-12-01

Because of their unique physical properties, three-dimensional (3D) graphene has attracted enormous attention over the past years. However, it is still a challenge to precisely control the layer thickness of 3D graphene. Here, we report a novel strategy to rationally adjust the wall thickness of ordered mesoporous graphene (OMG). By taking advantage of ligand exchange capability of colloidal Fe3O4 nanocrystals, we are able to fine-tune the wall thickness of OMG from 2 to 6 layers of graphene by tailoring the hydrocarbon ligands attached to the nanocrystal surface. When evaluated as electrocatalyst for oxygen reduction reaction upon S and N doping, the 4-layer OMG is found to show better catalytic performance compared with its 2- and 6-layer counterparts, which we attribute to the enhanced exposure of active sites resulting from its ultrathin wall thickness and high surface area.

Glycan shield and fusion activation of a deltacoronavirus spike glycoprotein fine-tuned for enteric infections.

Science.gov (United States)

Xiong, Xiaoli; Tortorici, M Alejandra; Snijder, Joost; Yoshioka, Craig; Walls, Alexandra C; Li, Wentao; McGuire, Andrew T; Rey, Félix A; Bosch, Berend-Jan; Veesler, David

2017-11-01

Coronaviruses recently emerged as major human pathogens causing outbreaks of severe acute respiratory syndrome and Middle-East respiratory syndrome. They utilize the spike (S) glycoprotein anchored in the viral envelope to mediate host attachment and fusion of the viral and cellular membranes to initiate infection. The S protein is a major determinant of the zoonotic potential of coronaviruses and is also the main target of the host humoral immune response. We report here the 3.5 Å resolution cryo-electron microscopy structure of the S glycoprotein trimer from the pathogenic porcine deltacoronavirus (PDCoV), which belongs to the recently identified delta genus. Structural and glycoproteomics data indicate that the glycans of PDCoV S are topologically conserved when compared with the human respiratory coronavirus HCoV-NL63 S, resulting in similar surface areas being shielded from neutralizing antibodies and implying that both viruses are under comparable immune pressure in their respective hosts. The structure further reveals a shortened S 2 ' activation loop, containing a reduced number of basic amino acids, which participates to rendering the spike largely protease-resistant. This property distinguishes PDCoV S from recently characterized betacoronavirus S proteins and suggests that the S protein of enterotropic PDCoV has evolved to tolerate the protease-rich environment of the small intestine and to fine-tune its fusion activation to avoid premature triggering and reduction of infectivity. IMPORTANCE Coronaviruses use transmembrane spike (S) glycoprotein trimers to promote host attachment and fusion of the viral and cellular membranes. We determined a near-atomic resolution cryo-electron microscopy structure of the S ectodomain trimer from the pathogenic porcine deltacoronavirus (PDCoV), which is responsible for diarrhea in piglets and has had devastating consequences for the swine industry worldwide. Structural and glycoproteomics data reveal that PDCoV S is

Regulation of mesenchymal stromal cells through fine tuning of canonical Wnt signaling

Directory of Open Access Journals (Sweden)

Jin-A Kim

2015-05-01

Full Text Available Mesenchymal stromal cells (MSCs have been extensively utilized for various cell therapeutic trials, but the signals regulating their stromal function remain largely unclear. Here, we show that canonical Wnt signals distinctively regulate MSCs in a biphasic manner depending on signal intensity, i.e., MSCs exhibit proliferation and progenitor self-renewal under low Wnt/β-catenin signaling, whereas they exhibit enhanced osteogenic differentiation with priming to osteoblast-like lineages under high Wnt/β-catenin signaling. Moreover, low or high levels of β-catenin in MSCs distinctly regulated the hematopoietic support of MSCs to promote proliferation or the undifferentiated state of hematopoietic progenitors, respectively. A gene expression study demonstrated that different intracellular levels of β-catenin in MSCs induce distinct transcriptomic changes in subsets of genes belonging to different gene function categories. Different β-catenin levels also induced differences in intracellular levels of the β-catenin co-factors, Tcf-1 and Lef-1. Moreover, nano-scale mass spectrometry of proteins that co-precipitated with β-catenin revealed distinctive spectra of proteins selectively interacting with β-catenin at specific expression levels. Together, these results show that Wnt/β-catenin signals can coax distinct transcription milieu to induce different transcription profiles in MSCs depending on the signal intensity and that fine-tuning of the canonical Wnt signaling intensity can regulate the phase-specific functionality of MSCs.

Deep learning in breast cancer risk assessment: evaluation of fine-tuned convolutional neural networks on a clinical dataset of FFDMs

Science.gov (United States)

Li, Hui; Mendel, Kayla R.; Lee, John H.; Lan, Li; Giger, Maryellen L.

2018-02-01

We evaluated the potential of deep learning in the assessment of breast cancer risk using convolutional neural networks (CNNs) fine-tuned on full-field digital mammographic (FFDM) images. This study included 456 clinical FFDM cases from two high-risk datasets: BRCA1/2 gene-mutation carriers (53 cases) and unilateral cancer patients (75 cases), and a low-risk dataset as the control group (328 cases). All FFDM images (12-bit quantization and 100 micron pixel) were acquired with a GE Senographe 2000D system and were retrospectively collected under an IRB-approved, HIPAA-compliant protocol. Regions of interest of 256x256 pixels were selected from the central breast region behind the nipple in the craniocaudal projection. VGG19 pre-trained on the ImageNet dataset was used to classify the images either as high-risk or as low-risk subjects. The last fully-connected layer of pre-trained VGG19 was fine-tuned on FFDM images for breast cancer risk assessment. Performance was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC) in the task of distinguishing between high-risk and low-risk subjects. AUC values of 0.84 (SE=0.05) and 0.72 (SE=0.06) were obtained in the task of distinguishing between the BRCA1/2 gene-mutation carriers and low-risk women and between unilateral cancer patients and low-risk women, respectively. Deep learning with CNNs appears to be able to extract parenchymal characteristics directly from FFDMs which are relevant to the task of distinguishing between cancer risk populations, and therefore has potential to aid clinicians in assessing mammographic parenchymal patterns for cancer risk assessment.

Fine tuning of optical signals in nanoporous anodic alumina photonic crystals by apodized sinusoidal pulse anodisation.

Science.gov (United States)

Santos, Abel; Law, Cheryl Suwen; Chin Lei, Dominique Wong; Pereira, Taj; Losic, Dusan

2016-11-03

In this study, we present an advanced nanofabrication approach to produce gradient-index photonic crystal structures based on nanoporous anodic alumina. An apodization strategy is for the first time applied to a sinusoidal pulse anodisation process in order to engineer the photonic stop band of nanoporous anodic alumina (NAA) in depth. Four apodization functions are explored, including linear positive, linear negative, logarithmic positive and logarithmic negative, with the aim of finely tuning the characteristic photonic stop band of these photonic crystal structures. We systematically analyse the effect of the amplitude difference (from 0.105 to 0.840 mA cm -2 ), the pore widening time (from 0 to 6 min), the anodisation period (from 650 to 950 s) and the anodisation time (from 15 to 30 h) on the quality and the position of the characteristic photonic stop band and the interferometric colour of these photonic crystal structures using the aforementioned apodization functions. Our results reveal that a logarithmic negative apodisation function is the most optimal approach to obtain unprecedented well-resolved and narrow photonic stop bands across the UV-visible-NIR spectrum of NAA-based gradient-index photonic crystals. Our study establishes a fully comprehensive rationale towards the development of unique NAA-based photonic crystal structures with finely engineered optical properties for advanced photonic devices such as ultra-sensitive optical sensors, selective optical filters and all-optical platforms for quantum computing.

Functional Role of PPARs in Ruminants: Potential Targets for Fine-Tuning Metabolism during Growth and Lactation

Science.gov (United States)

Chen, Shuowen; Khan, Muhammad J.; Loor, Juan J.

2013-01-01

Characterization and biological roles of the peroxisome proliferator-activated receptor (PPAR) isotypes are well known in monogastrics, but not in ruminants. However, a wealth of information has accumulated in little more than a decade on ruminant PPARs including isotype tissue distribution, response to synthetic and natural agonists, gene targets, and factors affecting their expression. Functional characterization demonstrated that, as in monogastrics, the PPAR isotypes control expression of genes involved in lipid metabolism, anti-inflammatory response, development, and growth. Contrary to mouse, however, the PPARγ gene network appears to controls milk fat synthesis in lactating ruminants. As in monogastrics, PPAR isotypes in ruminants are activated by long-chain fatty acids, therefore, making them ideal candidates for fine-tuning metabolism in this species via nutrients. In this regard, using information accumulated in ruminants and monogastrics, we propose a model of PPAR isotype-driven biological functions encompassing key tissues during the peripartal period in dairy cattle. PMID:23737762

Auto-Regulatory RNA Editing Fine-Tunes mRNA Re-Coding and Complex Behaviour in Drosophila

Science.gov (United States)

Savva, Yiannis A.; Jepson, James E.C; Sahin, Asli; Sugden, Arthur U.; Dorsky, Jacquelyn S.; Alpert, Lauren; Lawrence, Charles; Reenan, Robert A.

2014-01-01

Auto-regulatory feedback loops are a common molecular strategy used to optimize protein function. In Drosophila many mRNAs involved in neuro-transmission are re-coded at the RNA level by the RNA editing enzyme dADAR, leading to the incorporation of amino acids that are not directly encoded by the genome. dADAR also re-codes its own transcript, but the consequences of this auto-regulation in vivo are unclear. Here we show that hard-wiring or abolishing endogenous dADAR auto-regulation dramatically remodels the landscape of re-coding events in a site-specific manner. These molecular phenotypes correlate with altered localization of dADAR within the nuclear compartment. Furthermore, auto-editing exhibits sexually dimorphic patterns of spatial regulation and can be modified by abiotic environmental factors. Finally, we demonstrate that modifying dAdar auto-editing affects adaptive complex behaviors. Our results reveal the in vivo relevance of auto-regulatory control over post-transcriptional mRNA re-coding events in fine-tuning brain function and organismal behavior. PMID:22531175

One-dimensional array of gold nanoparticles fabricated using biotemplate and its application to fine FET

Science.gov (United States)

Ban, Takahiko; Uenuma, Mutsunori; Migita, Shinji; Okamoto, Naofumi; Ishikawa, Yasuaki; Uraoka, Yukiharu; Yamashita, Ichiro; Yamamoto, Shin-ichi

2018-06-01

By synthesizing AuS nanoparticles (NPs) with spherical shell protein (ferritin) and using a V-groove, a one-dimensional array of NPs was formed at the bottom of the V-groove. It has been reported that AuS NPs are converted to Au NPs by UV/ozone treatment. Floating gate memory (FGM) was fabricated by applying this one-dimensional array to V-grooved junctionless (JL) FETs, V-grooved nin-like-type FETs, and pip-like-type FETs, which are fine FETs. In JL-FETs, it is considered that conversion occurred because of good charge storage efficiency, and operation in the opposite direction to normal FGM operation was seen. In the nin-like and pip-like types devices, the same operation as in conventional FGM was shown, and the width of the memory window was about the same size as when one electron entered one NP. The one-dimensional arrangement of the metal NPs used in this study is considered to be applicable to various fields of nanotechnology.

Tuned Chamber Core Panel Acoustic Test Results

Science.gov (United States)

Schiller, Noah H.; Allen, Albert R.

2016-01-01

This report documents acoustic testing of tuned chamber core panels, which can be used to supplement the low-frequency performance of conventional acoustic treatment. The tuned chamber core concept incorporates low-frequency noise control directly within the primary structure and is applicable to sandwich constructions with a directional core, including corrugated-, truss-, and fluted-core designs. These types of sandwich structures have long, hollow channels (or chambers) in the core. By adding small holes through one of the facesheets, the hollow chambers can be utilized as an array of low-frequency acoustic resonators. These resonators can then be used to attenuate low-frequency noise (below 400 Hz) inside a vehicle compartment without increasing the weight or size of the structure. The results of this test program demonstrate that the tuned chamber core concept is effective when used in isolation or combined with acoustic foam treatments. Specifically, an array of acoustic resonators integrated within the core of the panels was shown to improve both the low-frequency absorption and transmission loss of the structure in targeted one-third octave bands.

Capability for Fine Tuning of the Refractive Index Sensing Properties of Long-Period Gratings by Atomic Layer Deposited Al2O3 Overlays

Directory of Open Access Journals (Sweden)

Mateusz Śmietana

2013-11-01

Full Text Available This work presents an application of thin aluminum oxide (Al2O3 films obtained using atomic layer deposition (ALD for fine tuning the spectral response and refractive-index (RI sensitivity of long-period gratings (LPGs induced in optical fibers. The technique allows for an efficient and well controlled deposition at monolayer level (resolution ~ 0.12 nm of excellent quality nano-films as required for optical sensors. The effect of Al2O3 deposition on the spectral properties of the LPGs is demonstrated experimentally and numerically. We correlated both the increase in Al2O3 thickness and changes in optical properties of the film with the shift of the LPG resonance wavelength and proved that similar films are deposited on fibers and oxidized silicon reference samples in the same process run. Since the thin overlay effectively changes the distribution of the cladding modes and thus also tunes the device’s RI sensitivity, the tuning can be simply realized by varying number of cycles, which is proportional to thickness of the high-refractive-index (n > 1.6 in infrared spectral range Al2O3 film. The advantage of this approach is the precision in determining the film properties resulting in RI sensitivity of the LPGs. To the best of our knowledge, this is the first time that an ultra-precise method for overlay deposition has been applied on LPGs for RI tuning purposes and the results have been compared with numerical simulations based on LP mode approximation.

Fine-Tuning the Quasi-3D Geometry: Enabling Efficient Nonfullerene Organic Solar Cells Based on Perylene Diimides.

Science.gov (United States)

Liu, Zhitian; Zhang, Linhua; Shao, Ming; Wu, Yao; Zeng, Di; Cai, Xiang; Duan, Jiashun; Zhang, Xiaolu; Gao, Xiang

2018-01-10

The geometries of acceptors based on perylene diimides (PDIs) are important for improving the phase separation and charge transport in organic solar cells. To fine-tune the geometry, biphenyl, spiro-bifluorene, and benzene were used as the core moiety to construct quasi-three-dimensional nonfullerene acceptors based on PDI building blocks. The molecular geometries, energy levels, optical properties, photovoltaic properties, and exciton kinetics were systematically studied. The structure-performance relationship was discussed as well. Owing to the finest phase separation, the highest charge mobility and smallest nongeminate recombination, the power conversion efficiency of nonfullerene solar cells using PDI derivatives with biphenyl core (BP-PDI 4 ) as acceptor reached 7.3% when high-performance wide band gap donor material poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))] was blended.

Characterization of electronic structures from CdS/Si nanoheterostructure array based on silicon nanoporous pillar array

Energy Technology Data Exchange (ETDEWEB)

Li, Yong, E-mail: liyong@pdsu.edu.cn [Department of Physics and Solar Energy Research Center, Pingdingshan University, Pingdingshan 467000 (China); Song, Xiao Yan [Department of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou 450045 (China); Song, Yue Li; Ji, Peng Fei; Zhou, Feng Qun; Tian, Ming Li; Huang, Hong Chun [Department of Physics and Solar Energy Research Center, Pingdingshan University, Pingdingshan 467000 (China); Li, Xin Jian [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China)

2016-02-15

Highlights: • CdS/Si nanoheterostructure array has been fabricated through a CBD method. • The electronic properties have been investigated by the I–V and C–V techniques. • The onset voltages, characteristic frequency and built-in potential are investigated. • The electronic structures can be tuned through the annealing treatments. - Abstract: The electronic properties of heterostructures are very important to its applications in the field of optoelectronic devices. Understanding and control of electronic properties are very necessary. CdS/Si nanoheterostructure array have been fabricated through growing CdS nanocrystals on the silicon nanoporous pillar array using a chemical bath deposition method. The electronic properties of CdS nanoheterostructure array have been investigated by the current–voltage, complex impedance spectroscopy and capacitance–voltage techniques. The onset voltages, characteristic frequency and built-in potential are gradually increased with increasing the annealing temperature. It is indicated that the electronic structures of CdS/Si nanoheterostructure array can be tuned through the annealing treatments.

Characterization of electronic structures from CdS/Si nanoheterostructure array based on silicon nanoporous pillar array

International Nuclear Information System (INIS)

Li, Yong; Song, Xiao Yan; Song, Yue Li; Ji, Peng Fei; Zhou, Feng Qun; Tian, Ming Li; Huang, Hong Chun; Li, Xin Jian

2016-01-01

Highlights: • CdS/Si nanoheterostructure array has been fabricated through a CBD method. • The electronic properties have been investigated by the I–V and C–V techniques. • The onset voltages, characteristic frequency and built-in potential are investigated. • The electronic structures can be tuned through the annealing treatments. - Abstract: The electronic properties of heterostructures are very important to its applications in the field of optoelectronic devices. Understanding and control of electronic properties are very necessary. CdS/Si nanoheterostructure array have been fabricated through growing CdS nanocrystals on the silicon nanoporous pillar array using a chemical bath deposition method. The electronic properties of CdS nanoheterostructure array have been investigated by the current–voltage, complex impedance spectroscopy and capacitance–voltage techniques. The onset voltages, characteristic frequency and built-in potential are gradually increased with increasing the annealing temperature. It is indicated that the electronic structures of CdS/Si nanoheterostructure array can be tuned through the annealing treatments.

New design concepts for ferrite-tuned low-energy-booster cavities

International Nuclear Information System (INIS)

Schaffer, G.

1991-05-01

The design concepts for ferrite-tuned accelerating cavities discussed in this paper differ from conventional solutions using thick ferrite toroids for frequency tuning. Instead, tuners consisting of an array of ferrite-loaded striplines are investigated. These promise more efficient cooling and higher operational reliability. Layout examples for the SSC-LEB rf system are presented (tuning range 47.5 to 59.8 MHz, repetition frequency 10 Hz). 15 refs., 4 figs., 1 tab

Vapor-melt Ratio in Laser Fine Cutting of Slot Arrays

International Nuclear Information System (INIS)

Wang Xuyue; Meng Qingxuan; Kang Renke; Xu Wenji; Guo Dongming; Wang Lianji

2011-01-01

In order to improve cut quality for slot arrays, a new method of laser fine cutting under the consideration of the ratio of vapor to melt is presented. Laser cutting of 6063 aluminum alloy sheet, 0.5 mm in thickness, was carried out on a JK701H Nd:YAG pulse laser cutting system. The effects of vapor-melt ratio on kerf width, surface roughness and recast layer were studied which relate cutting qualities. Observation on the cut samples with different vapor-melt ratios (0.687, 1.574, 3.601 varied with laser power increasing, and 1.535, 3.601, 7.661 with decreasing of beam cutting speed) shows that high vapor-melt ratio improves laser cut quality clearly. Kerf width 0.2 mm of smooth area on kerf top area and thickness 2.03 μm of recast layer are obtained. No dross was found on the kerf bottom and the percentage of the smooth area is up to 40% out of whole kerf side. The research on vapor-melt ratio provides a deeper understanding of laser cutting and improves laser cut quality effectively.

How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism.

Science.gov (United States)

Ezawa, Tatsuhiro; Saito, Katsuharu

2018-04-27

Contents Summary I. Introduction II. Foraging for phosphate III. Fine-tuning of phosphate homeostasis IV. The frontiers: phosphate translocation and export V. Conclusions and outlook Acknowledgements References SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

High energy, widely tunable Si-prism-array coupled terahertz-wave parametric oscillator with a deformed pump and optimal crystal location for angle tuning.

Science.gov (United States)

Zhang, Ruiliang; Qu, Yanchen; Zhao, Weijiang; Chen, Zhenlei

2017-03-20

A high energy, widely tunable Si-prism-array coupled terahertz-wave parametric oscillator (TPO) has been demonstrated by using a deformed pump. The deformed pump is cut from a beam spot of 2 mm in diameter by a 1-mm-wide slit. In comparison with a small pump spot (1-mm diameter), the THz-wave coupling area for the deformed pump is increased without limitation to the low-frequency end of the tuning range. Besides, the crystal location is specially designed to eliminate the alteration of the output position of the pump during angle tuning, so the initially adjusted nearest pumped region to the THz-wave exit surface is maintained throughout the tuning range. The tuning range is 0.58-2.5 THz for the deformed pump, while its low frequency end is limited at approximately 1.2 THz for the undeformed pump with 2 mm diameter. The highest THz-wave output of 2 μJ, which is 2.25 times as large as that from the pump of 1 mm in diameter, is obtained at 1.15 THz under 38 mJ (300  MW/cm2) pumping. The energy conversion efficiency is 5.3×10-5.

Deformable wire array: fiber drawn tunable metamaterials

DEFF Research Database (Denmark)

Fleming, Simon; Stefani, Alessio; Tang, Xiaoli

2017-01-01

By fiber drawing we fabricate a wire array metamaterial, the structure of which can be actively modified. The plasma frequency can be tuned by 50% by compressing the metamaterial; recovers when released and the process can be repeated.......By fiber drawing we fabricate a wire array metamaterial, the structure of which can be actively modified. The plasma frequency can be tuned by 50% by compressing the metamaterial; recovers when released and the process can be repeated....

Pore diameter control of anodic aluminum oxide with ordered array of nanopores

Energy Technology Data Exchange (ETDEWEB)

Bai, Allen; Yang, Yong-Feng [Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu, 30013 (China); Hu, Chi-Chang [Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 401 (China); Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 621 (China); Lin, Chi-Cheng [Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 621 (China)

2008-01-01

Highly uniform, self-ordered anodic aluminum oxide (AAO) with an ordered nanoporous array can be effectively formed from industrially pure (99.5%) aluminum sheets through an anodizing program in a mixture solution of sulfuric and oxalic acids. The influences of anodizing variables, such as applied voltage, solution temperature, oxalic acid concentration, agitation rate, and sulfuric acid concentration, on the average pore diameter of AAO were systematically investigated using fractional factorial design (FFD). The applied voltage, and sulfuric acid concentration were found to be the key factors affecting the pore diameter of AAO films in the FFD study. The pore diameter of AAO is regularly increased from ca. 50 to 150 nm when the applied voltage and the concentration of sulfuric acid are gradually increased from 53 to 80 V and from 3.5 to 8 M, respectively. Fine tuning of the pore diameter for AAO films with an ordered, nanoporous, arrayed structure from industrially pure aluminum sheets can be achieved. (author)

High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides

Science.gov (United States)

Charnukha, A.; Evtushinsky, D. V.; Matt, C. E.; Xu, N.; Shi, M.; Büchner, B.; Zhigadlo, N. D.; Batlogg, B.; Borisenko, S. V.

2015-12-01

In the family of the iron-based superconductors, the REFeAsO-type compounds (with RE being a rare-earth metal) exhibit the highest bulk superconducting transition temperatures (Tc) up to 55 K and thus hold the key to the elusive pairing mechanism. Recently, it has been demonstrated that the intrinsic electronic structure of SmFe0.92Co0.08AsO (Tc = 18 K) is highly nontrivial and consists of multiple band-edge singularities in close proximity to the Fermi level. However, it remains unclear whether these singularities are generic to the REFeAsO-type materials and if so, whether their exact topology is responsible for the aforementioned record Tc. In this work, we use angle-resolved photoemission spectroscopy (ARPES) to investigate the inherent electronic structure of the NdFeAsO0.6F0.4 compound with a twice higher Tc = 38 K. We find a similarly singular Fermi surface and further demonstrate that the dramatic enhancement of superconductivity in this compound correlates closely with the fine-tuning of one of the band-edge singularities to within a fraction of the superconducting energy gap Δ below the Fermi level. Our results provide compelling evidence that the band-structure singularities near the Fermi level in the iron-based superconductors must be explicitly accounted for in any attempt to understand the mechanism of superconducting pairing in these materials.

Model-independent particle accelerator tuning

Directory of Open Access Journals (Sweden)

Alexander Scheinker

2013-10-01

Full Text Available We present a new model-independent dynamic feedback technique, rotation rate tuning, for automatically and simultaneously tuning coupled components of uncertain, complex systems. The main advantages of the method are: (1 it has the ability to handle unknown, time-varying systems, (2 it gives known bounds on parameter update rates, (3 we give an analytic proof of its convergence and its stability, and (4 it has a simple digital implementation through a control system such as the experimental physics and industrial control system (EPICS. Because this technique is model independent it may be useful as a real-time, in-hardware, feedback-based optimization scheme for uncertain and time-varying systems. In particular, it is robust enough to handle uncertainty due to coupling, thermal cycling, misalignments, and manufacturing imperfections. As a result, it may be used as a fine-tuning supplement for existing accelerator tuning/control schemes. We present multiparticle simulation results demonstrating the scheme’s ability to simultaneously adaptively adjust the set points of 22 quadrupole magnets and two rf buncher cavities in the Los Alamos Neutron Science Center (LANSCE Linear Accelerator’s transport region, while the beam properties and rf phase shift are continuously varying. The tuning is based only on beam current readings, without knowledge of particle dynamics. We also present an outline of how to implement this general scheme in software for optimization, and in hardware for feedback-based control/tuning, for a wide range of systems.

Loss of Kdm5c Causes Spurious Transcription and Prevents the Fine-Tuning of Activity-Regulated Enhancers in Neurons

Directory of Open Access Journals (Sweden)

Marilyn Scandaglia

2017-10-01

Full Text Available During development, chromatin-modifying enzymes regulate both the timely establishment of cell-type-specific gene programs and the coordinated repression of alternative cell fates. To dissect the role of one such enzyme, the intellectual-disability-linked lysine demethylase 5C (Kdm5c, in the developing and adult brain, we conducted parallel behavioral, transcriptomic, and epigenomic studies in Kdm5c-null and forebrain-restricted inducible knockout mice. Together, genomic analyses and functional assays demonstrate that Kdm5c plays a critical role as a repressor responsible for the developmental silencing of germline genes during cellular differentiation and in fine-tuning activity-regulated enhancers during neuronal maturation. Although the importance of these functions declines after birth, Kdm5c retains an important genome surveillance role preventing the incorrect activation of non-neuronal and cryptic promoters in adult neurons.

Phased antenna arrays for fast wave power generation

International Nuclear Information System (INIS)

Bosia, G.; Jacquinot, J.

1991-01-01

A method for the generation of travelling waves in the Ion Cyclotron frequency range in JET is presented. The success of the method relies on the control of the array toroidal current, which in turn, is obtained by a coordinated vectorial control of the array power sources and tuning networks. This method has general application to present and future ICRF arrays. For uninterrupted, periodically fed and resonant toroidal arrays, phased operation requires only conventional tuning devices. For localised arrays, phased operation is inefficient at low plasma coupling. This inefficiency can be however removed with the addition of external coupling structures either at the antenna or at the generator ends. The performances of JET A1 antennae in phased operation is presented. The design philosophy for the JET A2 phased arrays is also discussed. These methods are applicable and extensible to Next Step Devices design

Fine-Tuned Intrinsically Ultramicroporous Polymers Redefine the Permeability/Selectivity Upper Bounds of Membrane-Based Air and Hydrogen Separations

KAUST Repository

Swaidan, Raja

2015-08-20

Intrinsically ultramicroporous (<7 Å) polymers represent a new paradigm in materials development for membrane-based gas separation. In particular, they demonstrate that uniting intrachain “rigidity”, the traditional design metric of highly permeable polymers of intrinsic microporosity (PIMs), with gas-sieving ultramicroporosity yields high-performance gas separation membranes. Highly ultramicroporous PIMs have redefined the state-of-the-art in large-scale air (e.g., O2/N2) and hydrogen recovery (e.g., H2/N2, H2/CH4) applications with unprecedented molecular sieving gas transport properties. Accordingly, presented herein are new 2015 permeability/selectivity “upper bounds” for large-scale commercial membrane-based air and hydrogen applications that accommodate the substantial performance enhancements of recent PIMs over preceding polymers. A subtle balance between intrachain rigidity and interchain spacing has been achieved in the amorphous microstructures of PIMs, fine-tuned using unique bridged-bicyclic building blocks (i.e., triptycene, ethanoanthracene and Tröger’s base) in both ladder and semiladder (e.g., polyimide) structures.

Efficiency analysis of using tailored individual doses of radioiodine and fine tuning using a low-dose antithyroid drug in the treatment of Graves' disease.

Science.gov (United States)

Liu, Chang-Jiang; Dong, Yan-Yu; Wang, Yi-Wei; Wang, Kai-Hua; Zeng, Qun-Yan

2011-03-01

To evaluate the effect of using tailored individual doses of radioiodine (¹³¹I) and fine tuning using low-dose antithyroid drug (ATD) in the treatment of Graves' disease, and an attempt to establish a therapeutic strategy that can keep both high rate of euthyroidism and low incidence of hypothyroidism. The dose of radioiodine was calculated using the calculated dose formula, and low-dose ATD was used as a way of fine tuning during follow-up. The intended dose of radioiodine was modified according to the patient's age at radioiodine therapy, thyroid size, and duration of hyperthyroidism before radioiodine therapy in the study group; it was set as 2.96 MBq/g of thyroid in the control group. Twenty patients with Graves' disease were nonrandomly assigned to the control group and 98 patients with Graves' disease to the study group. The outcomes, which included euthyroidism, hypothyroidism, and persistent hyperthyroidism, were determined according to the patients' states at the end of follow-up. In the study group, 74 patients (75.5%) achieved the euthyroid state, six patients (6.1%) became hypothyroid, and 18 patients (18.4%) remained hyperthyroid. The rate of euthyroidism was statistically different between the study group and the control group (75.5 vs. 50%, P=0.03). Of 98 patients with Graves' disease in the study group, 19 patients were additionally treated with ATD during follow-up, and 12 patients achieved euthyroidism. In different age groups or duration of hyperthyroidism groups, the rate of euthyroidism was not statistically different among subgroups of goiter grade 1, grade 2, and grade 3 (P>0.05). Similarly, in different age groups or duration of hyperthyroidism groups, the incidence of hypothyroidism was not statistically different among subgroups of goiter grade 1, grade 2, and grade 3 (P>0.05). However, binary logistic regression analysis showed that thyroid size was associated with overtreatment and undertreatment in our study. Individual doses of

Bandwidth Widening of Piezoelectric Cantilever Beam Arrays by Mass-Tip Tuning for Low-Frequency Vibration Energy Harvesting

Directory of Open Access Journals (Sweden)

Eduard Dechant

2017-12-01

Full Text Available Wireless sensor networks usually rely on internal permanent or rechargeable batteries as a power supply, causing high maintenance efforts. An alternative solution is to supply the entire system by harvesting the ambient energy, for example, by transducing ambient vibrations into electric energy by virtue of the piezoelectric effect. The purpose of this paper is to present a simple engineering approach for the bandwidth optimization of vibration energy harvesting systems comprising multiple piezoelectric cantilevers (PECs. The frequency tuning of a particular cantilever is achieved by changing the tip mass. It is shown that the bandwidth enhancement by mass tuning is limited and requires several PECs with close resonance frequencies. At a fixed frequency detuning between subsequent PECs, the achievable bandwidth shows a saturation behavior as a function of the number of cantilevers used. Since the resonance frequency of each PEC is different, the output voltages at a particular excitation frequency have different amplitudes and phases. A simple power-transfer circuit where several PECs with an individual full wave bridge rectifier are connected in parallel allows one to extract the electrical power close to the theoretical maximum excluding the diode losses. The experiments performed on two- and three-PEC arrays show reasonable agreement with simulations and demonstrate that this power-transfer circuit additionally influences the frequency dependence of the harvested electrical power.

'Fine-tuning' blood flow to the exercising muscle with advancing age: an update.

Science.gov (United States)

Wray, D Walter; Richardson, Russell S

2015-06-01

What is the topic of this review? This review focuses on age-related changes in the regulatory pathways that exist at the unique interface between the vascular smooth muscle and the endothelium of the skeletal muscle vasculature, and how these changes contribute to impairments in exercising skeletal muscle blood flow in the elderly. What advances does it highlight? Several recent in vivo human studies from our group and others are highlighted that have examined age-related changes in nitric oxide, endothelin-1, alpha adrenergic, and renin-angiotensin-aldosterone (RAAS) signaling. During dynamic exercise, oxygen demand from the exercising muscle is dramatically elevated, requiring a marked increase in skeletal muscle blood flow that is accomplished through a combination of systemic sympathoexcitation and local metabolic vasodilatation. With advancing age, the balance between these factors appears to be disrupted in favour of vasoconstriction, leading to an impairment in exercising skeletal muscle blood flow in the elderly. This 'hot topic' review aims to provide an update to our current knowledge of age-related changes in the neural and local mechanisms that contribute to this 'fine-tuning' of blood flow during exercise. The focus is on results from recent human studies that have adopted a reductionist approach to explore how age-related changes in both vasodilators (nitric oxide) and vasoconstrictors (endothelin-1, α-adrenergic agonists and angiotensin II) interact and how these changes impact blood flow to the exercising skeletal muscle with advancing age. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

Fine-grained, local maps and coarse, global representations support human spatial working memory.

Directory of Open Access Journals (Sweden)

Mohammad Zia Ul Haq Katshu

Full Text Available While sensory processes are tuned to particular features, such as an object's specific location, color or orientation, visual working memory (vWM is assumed to store information using representations, which generalize over a feature dimension. Additionally, current vWM models presume that different features or objects are stored independently. On the other hand, configurational effects, when observed, are supposed to mainly reflect encoding strategies. We show that the location of the target, relative to the display center and boundaries, and overall memory load influenced recall precision, indicating that, like sensory processes, capacity limited vWM resources are spatially tuned. When recalling one of three memory items the target distance from the display center was overestimated, similar to the error when only one item was memorized, but its distance from the memory items' average position was underestimated, showing that not only individual memory items' position, but also the global configuration of the memory array may be stored. Finally, presenting the non-target items at recall, consequently providing landmarks and configurational information, improved precision and accuracy of target recall. Similarly, when the non-target items were translated at recall, relative to their position in the initial display, a parallel displacement of the recalled target was observed. These findings suggest that fine-grained spatial information in vWM is represented in local maps whose resolution varies with distance from landmarks, such as the display center, while coarse representations are used to store the memory array configuration. Both these representations are updated at the time of recall.

Fine-Grained, Local Maps and Coarse, Global Representations Support Human Spatial Working Memory

Science.gov (United States)

Katshu, Mohammad Zia Ul Haq; d'Avossa, Giovanni

2014-01-01

While sensory processes are tuned to particular features, such as an object's specific location, color or orientation, visual working memory (vWM) is assumed to store information using representations, which generalize over a feature dimension. Additionally, current vWM models presume that different features or objects are stored independently. On the other hand, configurational effects, when observed, are supposed to mainly reflect encoding strategies. We show that the location of the target, relative to the display center and boundaries, and overall memory load influenced recall precision, indicating that, like sensory processes, capacity limited vWM resources are spatially tuned. When recalling one of three memory items the target distance from the display center was overestimated, similar to the error when only one item was memorized, but its distance from the memory items' average position was underestimated, showing that not only individual memory items' position, but also the global configuration of the memory array may be stored. Finally, presenting the non-target items at recall, consequently providing landmarks and configurational information, improved precision and accuracy of target recall. Similarly, when the non-target items were translated at recall, relative to their position in the initial display, a parallel displacement of the recalled target was observed. These findings suggest that fine-grained spatial information in vWM is represented in local maps whose resolution varies with distance from landmarks, such as the display center, while coarse representations are used to store the memory array configuration. Both these representations are updated at the time of recall. PMID:25259601

ZIF-8 gate tuning via terminal group modification: a computational study

KAUST Repository

Zheng, Bin

2016-06-24

Tuning the pore structure of zeolitic imidazolate frameworks (ZIFs) enables unique control of their material properties. In this work, we used computational methods to examine the gate structure of ZIF-8 tuned by substitution terminal groups. The substitution position and electron affinity of the added groups were shown to be key factors in gate size. Electrostatic interactions are responsible for the variation in gate opening. These results suggest that the post-modification of terminal group in ZIFs can be used to finely tune the pore gate, opening up new strategies in the design of ZIFs with desired properties.

Elastomeric composites with tuned electromagnetic characteristics

International Nuclear Information System (INIS)

Wheeland, Sara; Bayatpur, Farhad; Amirkhizi, Alireza V; Nemat-Nasser, Sia

2013-01-01

This paper presents a novel elastomeric composite that exhibits a deformation-induced change in chirality. Previous efforts primarily dealt with a coil array in air without chiral tuning. Here, a composite is created that consists of an array of parallel, metallic helices of the same handedness embedded in a polymer matrix. The chiral response of the composite depends on pitch, coil diameter, wire thickness and coil spacing; however, pitch has the greatest effect on electromagnetic performance. The present study explores this effect by using helical elements to construct a chiral medium that can be mechanically stretched to adjust pitch. This adjustment directly affects the overall chirality of the composite. A prototype sample of the composite, fabricated for operation between 5.5–12.5 GHz, demonstrates repeatable elastic deformation. Using a transmit/receive measurement setup, the composite scattering response is measured over the frequency interval. The results indicate substantial tuning of chirality through deformation. An increase in axial strain of up to 30% yields a ∼18% change in axial chirality. (paper)

Computer-automated tuning of semiconductor double quantum dots into the single-electron regime

NARCIS (Netherlands)

Baart, T.A.; Eendebak, P.T.; Reichl, C.; Wegscheider, W.; Vandersypen, L.M.K.

2016-01-01

We report the computer-automated tuning of gate-defined semiconductor double quantum dots in GaAs heterostructures. We benchmark the algorithm by creating three double quantum dots inside a linear array of four quantum dots. The algorithm sets the correct gate voltages for all the gates to tune the

Integration of spintronic interface for nanomagnetic arrays

Directory of Open Access Journals (Sweden)

Andrew Lyle

2011-12-01

Full Text Available An experimental demonstration utilizing a spintronic input/output (I/O interface for arrays of closely spaced nanomagnets is presented. The free layers of magnetic tunnel junctions (MTJs form dipole coupled nanomagnet arrays which can be applied to different contexts including Magnetic Quantum Cellular Automata (MQCA for logic applications and self-biased devices for field sensing applications. Dipole coupled nanomagnet arrays demonstrate adaptability to a variety of contexts due to the ability for tuning of magnetic response. Spintronics allows individual nanomagnets to be manipulated with spin transfer torque and monitored with magnetoresistance. This facilitates measurement of the magnetic coupling which is important for (yet to be demonstrated data propagation reliability studies. In addition, the same magnetic coupling can be tuned to reduce coercivity for field sensing. Dipole coupled nanomagnet arrays have the potential to be thousands of times more energy efficient than CMOS technology for logic applications, and they also have the potential to form multi-axis field sensors.

Fine-Tuning of Polymeric Resins and their Interfaces with Amorphous Calcium Phosphate. A Strategy for Designing Effective Remineralizing Dental Composites

Directory of Open Access Journals (Sweden)

Drago Skrtic

2010-09-01

Full Text Available For over a decade our group has been designing, preparing and evaluating bioactive, remineralizing composites based on amorphous calcium phosphate (ACP fillers embedded in polymerized methacrylate resin matrices. In these studies a major focus has been on exploring structure-property relationships of the matrix phase of these composites on their anti-cariogenic potential. The main challenges were to gain a better understanding of polymer matrix/filler interfacial properties through controlling the surface properties of the fillers or through fine-tuning of the resin matrix. In this work, we describe the effect of chemical structure and composition of the resin matrices on some of the critical physicochemical properties of the copolymers and their ACP composites. Such structure-property studies are essential in formulating clinically effective products, and this knowledge base is likely to have strong impact on the future design of therapeutic materials, appropriate for mineral restoration in defective tooth structures.

A ROP2-RIC1 pathway fine-tunes microtubule reorganization for salt tolerance in Arabidopsis.

Science.gov (United States)

Li, Changjiang; Lu, Hanmei; Li, Wei; Yuan, Ming; Fu, Ying

2017-07-01

The reorganization of microtubules induced by salt stress is required for Arabidopsis survival under high salinity conditions. RIC1 is an effector of Rho-related GTPase from plants (ROPs) and a known microtubule-associated protein. In this study, we demonstrated that RIC1 expression decreased with long-term NaCl treatment, and ric1-1 seedlings exhibited a higher survival rate under salt stress. We found that RIC1 reduced the frequency of microtubule transition from shortening to growing status and knockout of RIC1 improved the reassembly of depolymerized microtubules caused by either oryzalin treatment or salt stress. Further investigation showed that constitutively active ROP2 promoted the reassembly of microtubules and the survival of seedlings under salt stress. A rop2-1 ric1-1 double mutant rescued the salt-sensitive phenotype of rop2-1, indicating that ROP2 functions in salt tolerance through RIC1. Although ROP2 did not regulate RIC1 expression upon salt stress, a quick but mild increase of ROP2 activity was induced, led to reduction of RIC1 on microtubules. Collectively, our study reveals an ROP2-RIC1 pathway that fine-tunes microtubule dynamics in response to salt stress in Arabidopsis. This finding not only reveals a new regulatory mechanism for microtubule reorganization under salt stress but also the importance of ROP signalling for salinity tolerance. © 2017 John Wiley & Sons Ltd.

Formation of semi-IPN membrane composed of crosslinked SPS-[PVdF-co-HFP/Nafion] for application in DMFC: A fine tuning between crosslinker and initiator

Energy Technology Data Exchange (ETDEWEB)

Kumar, Piyush; Kundu, Patit Paban, E-mail: ppk923@yahoo.com

2015-08-15

The semi-interpenetrating (semi-IPN) membrane composed of crosslinked sulfonated polystyrene (SPS) within the host blend of PVdF-co-HFP (Polyvinylidenefluoride-co-hexafluoropropylene) and Nafion has already been tested as a promising polymer electrolyte membrane (PEM) in terms of improved water uptake, proton conductivity and electrical efficiency for application in the direct methanol fuel cell (DMFC). These desired results have generated further curiosity about a fine tuning between the contents of divinyl benzene (DVB) as a crosslinker and azobisisobutyronitrile (AIBN) as an initiator for the optimization of PEM characteristics. It has been observed that an increase in AIBN content leads to an acceptable degree of water uptake, swelling ratio and proton conductivity in PEM, while higher DVB content causes declined methanol crossover, leading to higher membrane selectivity. These two opposing effects are optimized in terms of proton conductivity, tensile strength and membrane selectivity for the membrane consisting of 0.4 wt% of AIBN and 1.2 wt% of DVB. Moreover, the maximum power density obtained for the membrane having optimum selectivity is 56 mW cm{sup −2}, when analyzed at 90 °C. These results indicate that one can achieve a high power density in comparison to Nafion by fine tuning the contents of initiator and cross-linker during the synthesis of the semi-IPN membrane. - Graphical abstract: Display Omitted - Highlights: • PEM composed of 0.4/1.2 wt% of AIBN/DVB produced best result. • Lower methanol crossover (1.02 × 10{sup −6} cm{sup 2} s{sup −1}) compare to Nafion-117. • Higher membrane selectivity i.e 3.05 × 10{sup 4} Ss cm{sup −3} was obtained. • A maximum power density of 56 mW cm{sup −2} was obtained at 90 °C.

Formation of semi-IPN membrane composed of crosslinked SPS-[PVdF-co-HFP/Nafion] for application in DMFC: A fine tuning between crosslinker and initiator

International Nuclear Information System (INIS)

Kumar, Piyush; Kundu, Patit Paban

2015-01-01

The semi-interpenetrating (semi-IPN) membrane composed of crosslinked sulfonated polystyrene (SPS) within the host blend of PVdF-co-HFP (Polyvinylidenefluoride-co-hexafluoropropylene) and Nafion has already been tested as a promising polymer electrolyte membrane (PEM) in terms of improved water uptake, proton conductivity and electrical efficiency for application in the direct methanol fuel cell (DMFC). These desired results have generated further curiosity about a fine tuning between the contents of divinyl benzene (DVB) as a crosslinker and azobisisobutyronitrile (AIBN) as an initiator for the optimization of PEM characteristics. It has been observed that an increase in AIBN content leads to an acceptable degree of water uptake, swelling ratio and proton conductivity in PEM, while higher DVB content causes declined methanol crossover, leading to higher membrane selectivity. These two opposing effects are optimized in terms of proton conductivity, tensile strength and membrane selectivity for the membrane consisting of 0.4 wt% of AIBN and 1.2 wt% of DVB. Moreover, the maximum power density obtained for the membrane having optimum selectivity is 56 mW cm −2 , when analyzed at 90 °C. These results indicate that one can achieve a high power density in comparison to Nafion by fine tuning the contents of initiator and cross-linker during the synthesis of the semi-IPN membrane. - Graphical abstract: Display Omitted - Highlights: • PEM composed of 0.4/1.2 wt% of AIBN/DVB produced best result. • Lower methanol crossover (1.02 × 10 −6 cm 2 s −1 ) compare to Nafion-117. • Higher membrane selectivity i.e 3.05 × 10 4 Ss cm −3 was obtained. • A maximum power density of 56 mW cm −2 was obtained at 90 °C

Multimodal tuned dynamic absorber for split Stirling linear cryocooler

Science.gov (United States)

Veprik, A.; Tuito, A.

2017-02-01

Forthcoming low size, weight, power and price split Stirling linear cryocoolers may rely on electro-dynamically driven single-piston compressors and pneumatically driven expanders interconnected by the configurable transfer line. For compactness, compressor and expander units may be placed in a side-by-side manner, thus producing tonal vibration export comprising force and moment components. In vibration sensitive applications, this may result in excessive angular line of sight jitter and translational defocusing affecting the image quality. The authors present Multimodal Tuned Dynamic Absorber (MTDA), having one translational and two tilting modes essentially tuned to the driving frequency. The dynamic reactions (force and moment) produced by such a MTDA are simultaneously counterbalancing force and moment vibration export produced by the cryocooler. The authors reveal the design details, the method of fine modal tuning and outcomes of numerical simulation on attainable performance.

Rate of hydrolysis in ATP synthase is fine-tuned by  -subunit motif controlling active site conformation

KAUST Repository

Beke-Somfai, T.; Lincoln, P.; Norden, B.

2013-01-01

Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. F(o)F(1) ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F(1) performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate.

Rate of hydrolysis in ATP synthase is fine-tuned by  -subunit motif controlling active site conformation

KAUST Repository

Beke-Somfai, T.

2013-01-23

Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. F(o)F(1) ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F(1) performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate.

Vortex lattice in effective type-I superconducting films with periodic arrays of submicron holes

International Nuclear Information System (INIS)

Berdiyorov, G.R.; Milosevic, M.V.; Peeters, F.M.

2006-01-01

The vortex matter and related phenomena in superconducting films with periodic arrays of microholes (antidots) are studied within the nonlinear Ginzburg-Landau (GL) theory. By varying the GL parameter κ, the vortex-vortex interaction is fine tuned, from repulsive to attractive behavior. This interaction is of crucial importance for equilibrium vortex structures, the saturation number of the antidots, and the related quantities, such as critical current. Due to vortex attraction in effectively type-I samples, the giant-vortex state becomes energetically favorable (contrary to the type-II behavior). For the same reason, the number of vortices which can be captured by antidots, increases with decreasing κ. As a result, for given magnetic field, the critical current is larger for effectively type-I superconductors than in conventional type-II cases

Nature-inspired Cuckoo Search Algorithm for Side Lobe Suppression in a Symmetric Linear Antenna Array

Directory of Open Access Journals (Sweden)

K. N. Abdul Rani

2012-09-01

Full Text Available In this paper, we proposed a newly modified cuckoo search (MCS algorithm integrated with the Roulette wheel selection operator and the inertia weight controlling the search ability towards synthesizing symmetric linear array geometry with minimum side lobe level (SLL and/or nulls control. The basic cuckoo search (CS algorithm is primarily based on the natural obligate brood parasitic behavior of some cuckoo species in combination with the Levy flight behavior of some birds and fruit flies. The CS metaheuristic approach is straightforward and capable of solving effectively general N-dimensional, linear and nonlinear optimization problems. The array geometry synthesis is first formulated as an optimization problem with the goal of SLL suppression and/or null prescribed placement in certain directions, and then solved by the newly MCS algorithm for the optimum element or isotropic radiator locations in the azimuth-plane or xy-plane. The study also focuses on the four internal parameters of MCS algorithm specifically on their implicit effects in the array synthesis. The optimal inter-element spacing solutions obtained by the MCS-optimizer are validated through comparisons with the standard CS-optimizer and the conventional array within the uniform and the Dolph-Chebyshev envelope patterns using MATLABTM. Finally, we also compared the fine-tuned MCS algorithm with two popular evolutionary algorithm (EA techniques include particle swarm optimization (PSO and genetic algorithms (GA.

Deep learning-based fine-grained car make/model classification for visual surveillance

Science.gov (United States)

Gundogdu, Erhan; Parıldı, Enes Sinan; Solmaz, Berkan; Yücesoy, Veysel; Koç, Aykut

2017-10-01

Fine-grained object recognition is a potential computer vision problem that has been recently addressed by utilizing deep Convolutional Neural Networks (CNNs). Nevertheless, the main disadvantage of classification methods relying on deep CNN models is the need for considerably large amount of data. In addition, there exists relatively less amount of annotated data for a real world application, such as the recognition of car models in a traffic surveillance system. To this end, we mainly concentrate on the classification of fine-grained car make and/or models for visual scenarios by the help of two different domains. First, a large-scale dataset including approximately 900K images is constructed from a website which includes fine-grained car models. According to their labels, a state-of-the-art CNN model is trained on the constructed dataset. The second domain that is dealt with is the set of images collected from a camera integrated to a traffic surveillance system. These images, which are over 260K, are gathered by a special license plate detection method on top of a motion detection algorithm. An appropriately selected size of the image is cropped from the region of interest provided by the detected license plate location. These sets of images and their provided labels for more than 30 classes are employed to fine-tune the CNN model which is already trained on the large scale dataset described above. To fine-tune the network, the last two fully-connected layers are randomly initialized and the remaining layers are fine-tuned in the second dataset. In this work, the transfer of a learned model on a large dataset to a smaller one has been successfully performed by utilizing both the limited annotated data of the traffic field and a large scale dataset with available annotations. Our experimental results both in the validation dataset and the real field show that the proposed methodology performs favorably against the training of the CNN model from scratch.

Fine tuning of transmission features in nanoporous anodic alumina distributed Bragg reflectors

Science.gov (United States)

Lim, Siew Yee; Law, Cheryl Suwen; Santos, Abel

2018-01-01

This study introduces an innovative apodisation strategy to tune the filtering features of distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs). The effective medium of NAA-DBRs, which is modulated in a stepwise fashion by a pulse-like anodisation approach, is apodised following a logarithmic negative function to engineer the transmission features of NAA-DBRs. We investigate the effect of various apodisation parameters such as apodisation amplitude difference, anodisation period, current density offset and pore widening time, to tune and optimise the optical properties of NAA-DBRs in terms of central wavelength position, full width at half maximum and quality of photonic stop band. The transmission features of NAA-DBRs are shown to be fully controllable with precision across the spectral regions by means of the apodisation parameters. Our study demonstrates that an apodisation strategy can significantly narrow the width and enhance the quality of the characteristic photonic stop band of NAA-DBRs. This rationally designed anodisation approach based on the combination of apodisation and stepwise pulse anodisation enables the development of optical filters with tuneable filtering features to be integrated into optical technologies acting as essential photonic elements in devices such as optical sensors and biosensors.

Hierarchical interactions between Fnr orthologs allows fine-tuning of transcription in response to oxygen in Herbaspirillum seropedicae.

Science.gov (United States)

Batista, Marcelo Bueno; Chandra, Govind; Monteiro, Rose Adele; de Souza, Emanuel Maltempi; Dixon, Ray

2018-05-04

Bacteria adjust the composition of their electron transport chain (ETC) to efficiently adapt to oxygen gradients. This involves differential expression of various ETC components to optimize energy generation. In Herbaspirillum seropedicae, reprogramming of gene expression in response to oxygen availability is controlled at the transcriptional level by three Fnr orthologs. Here, we characterised Fnr regulons using a combination of RNA-Seq and ChIP-Seq analysis. We found that Fnr1 and Fnr3 directly regulate discrete groups of promoters (Groups I and II, respectively), and that a third group (Group III) is co-regulated by both transcription factors. Comparison of DNA binding motifs between the three promoter groups suggests Group III promoters are potentially co-activated by Fnr3-Fnr1 heterodimers. Specific interaction between Fnr1 and Fnr3, detected in two-hybrid assays, was dependent on conserved residues in their dimerization interfaces, indicative of heterodimer formation in vivo. The requirements for co-activation of the fnr1 promoter, belonging to Group III, suggest either sequential activation by Fnr3 and Fnr1 homodimers or the involvement of Fnr3-Fnr1 heterodimers. Analysis of Fnr proteins with swapped activation domains provides evidence that co-activation by Fnr1 and Fnr3 at Group III promoters optimises interactions with RNA polymerase to fine-tune transcription in response to prevailing oxygen concentrations.

Computer-automated tuning of semiconductor double quantum dots into the single-electron regime

Energy Technology Data Exchange (ETDEWEB)

Baart, T. A.; Vandersypen, L. M. K. [QuTech, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Eendebak, P. T. [QuTech, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Netherlands Organisation for Applied Scientific Research (TNO), P.O. Box 155, 2600 AD Delft (Netherlands); Reichl, C.; Wegscheider, W. [Solid State Physics Laboratory, ETH Zürich, 8093 Zürich (Switzerland)

2016-05-23

We report the computer-automated tuning of gate-defined semiconductor double quantum dots in GaAs heterostructures. We benchmark the algorithm by creating three double quantum dots inside a linear array of four quantum dots. The algorithm sets the correct gate voltages for all the gates to tune the double quantum dots into the single-electron regime. The algorithm only requires (1) prior knowledge of the gate design and (2) the pinch-off value of the single gate T that is shared by all the quantum dots. This work significantly alleviates the user effort required to tune multiple quantum dot devices.

Quantitative (23) Na MRI of human knee cartilage using dual-tuned (1) H/(23) Na transceiver array radiofrequency coil at 7 tesla.

Science.gov (United States)

Moon, Chan Hong; Kim, Jung-Hwan; Zhao, Tiejun; Bae, Kyongtae Ty

2013-11-01

To develop quantitative dual-tuned (DT) (1) H/(23) Na MRI of human knee cartilage in vivo at 7 Tesla (T). A sensitive (23) Na transceiver array RF coil was developed at 7T. B1 fields generated by the transceiver array coil were characterized and corrected in the (23) Na images. Point spread function (PSF) of the (23) Na images was measured, and the signal decrease due to partial-volume-effect was compensated in [(23) Na] quantification of knee cartilage. SNR and [(23) Na] in anterior femoral cartilage were measured from seven healthy subjects. SNR of (23) Na image with the transceiver array coil was higher than that of birdcage coil. SNR in the cartilage at 2-mm isotropic resolution was 26.80 ± 3.69 (n = 7). B1 transmission and reception fields produced by the DT coil at 7T were similar to each other. Effective full-width-half-maximum of (23) Na image was ∼5 mm at 2-mm resolution. Mean [(23) Na] was 288.13 ± 29.50 mM (n = 7) in the anterior femoral cartilage of normal subjects. We developed a new high-sensitivity (23) Na RF coil for knee MRI at 7T. Our (1) H/(23) Na MRI allowed quantitative measurement of [(23) Na] in knee cartilage by measuring PSF and cartilage thickness from (23) Na and (1) H image, respectively. Copyright © 2013 Wiley Periodicals, Inc.

Rectangle Surface Coil Array in a Grid Arrangement for Resonance Imaging

Science.gov (United States)

2016-02-13

magnet wires with insulating coating for rectangular surface coils. The wires are formed into four one turn 145mm x 32mm rectangular coils...switchable array, RF magnetic field, NQR, MRI, NMR, tuning, decoupling I. INTRODUCTION ESONANCE imaging can be accomplished using Nuclear Magnetic ...grid array. This achieves the switchable array configuration. Later, investigations will have circuit controlled multiplexer for switching to

Controllability of the Coulomb charging energy in close-packed nanoparticle arrays.

Science.gov (United States)

Duan, Chao; Wang, Ying; Sun, Jinling; Guan, Changrong; Grunder, Sergio; Mayor, Marcel; Peng, Lianmao; Liao, Jianhui

2013-11-07

We studied the electronic transport properties of metal nanoparticle arrays, particularly focused on the Coulomb charging energy. By comparison, we confirmed that it is more reasonable to estimate the Coulomb charging energy using the activation energy from the temperature-dependent zero-voltage conductance. Based on this, we systematically and comprehensively investigated the parameters that could be used to tune the Coulomb charging energy in nanoparticle arrays. We found that four parameters, including the particle core size, the inter-particle distance, the nearest neighboring number, and the dielectric constant of ligand molecules, could significantly tune the Coulomb charging energy.

Pendant chain engineering to fine-tune the nanomorphologies and solid state luminescence of naphthalimide AIEEgens: application to phenolic nitro-explosive detection in water.

Science.gov (United States)

Meher, Niranjan; Iyer, Parameswar Krishnan

2017-06-08

Strategically, a series of five angular "V" shaped naphthalimide AIEEgens with varying pendant chains (butyl, hexyl, octyl, cyclohexyl and methylcyclohexyl) have been synthesized to fine-tune their nanomorphological and photophysical properties. With similar aromatic cores and electronic states, unexpected tuning of the condensed state emission colors and nanomorphologies (reproducible on any kind of surface) of naphthalimides has been achieved for the first time simply by varying their side chains. Conclusive analysis by various spectroscopic techniques (SC-XRD, powder-XRD, DLS, FESEM) and DFT computational studies confirmed the full control of the pendant chain (in terms of bulkiness around the naphthalimide core, which restricts the ease of intermolecular π-π interactions) over the nanoaggregate morphology and solid state emissive properties of the AIEEgens; this can be rationalized to all aggregation-prone systems. These comprehensive studies establish a conceptually unique yet simple and effective method to precisely tune the nanomorphologies and the emission colors of aggregation-prone small organic molecules by judicious choice of the non-conjugated pendant chain. Thus, considering the prime role of the active layer nanomorphology in all organic optoelectronic devices, this methodology may emerge as a promising tool to improve device performance. Among all the congeners, the hexyl chain-containing congener (HNQ) forms well-defined nanoribbons with smaller diameters (as confirmed from DLS: 166 nm and FESEM: 150 nm) and provides a larger surface area. Consequently, the HNQ-nanoribbons were employed as a fluorescent sensor for the discriminative detection of trinitrophenol (TNP) in pure aqueous media. FE-SEM images revealed that, upon gradual addition of TNP (10 nM to 100 μM), these nanoribbons undergo an aggregation/disaggregation process, forming non-fluorescent co-aggregates with TNP, and provide highly enhanced sensitivity compared to existing state

Performance of prototype segmented CdZnTe arrays

International Nuclear Information System (INIS)

Parsons, A.; Palmer, D.M.; Kurczynski, P.; Barbier, L.; Barthelmy, S.; Bartlett, L.; Gehrels, N.; Krizmanic, J.; Stahle, C.M.; Tueller, J.; Teegarden, B.

1998-01-01

The Burst and All Sky Imaging Survey (BASIS) is a proposed mission to provide ∼3 arc second locations of approximately 90 Gamma-Ray Bursts (GRBs) per year. The BASIS coded aperture imaging system requires a segmented detector plane able to detect the interaction position of (10--150 keV) photons to less than 100 microm. To develop prototype detector arrays with such fine position resolution the authors have fabricated many 15 mm x 15 mm x 2 mm 100 microm pitch CdZnTe strip detectors. They have assembled these fine pitch CdZnTe strip detectors into prototype 2 x 2 and 6 x 6 element arrays read out by ASIC electronics. The assembly and electronics readout of the 6 x 6 flight prototype array will be discussed, and preliminary data illustrating the uniformity and efficiency of the array will be presented

Self-assembly based plasmonic arrays tuned by atomic layer deposition for extreme visible light absorption.

Science.gov (United States)

Hägglund, Carl; Zeltzer, Gabriel; Ruiz, Ricardo; Thomann, Isabell; Lee, Han-Bo-Ram; Brongersma, Mark L; Bent, Stacey F

2013-07-10

Achieving complete absorption of visible light with a minimal amount of material is highly desirable for many applications, including solar energy conversion to fuel and electricity, where benefits in conversion efficiency and economy can be obtained. On a fundamental level, it is of great interest to explore whether the ultimate limits in light absorption per unit volume can be achieved by capitalizing on the advances in metamaterial science and nanosynthesis. Here, we combine block copolymer lithography and atomic layer deposition to tune the effective optical properties of a plasmonic array at the atomic scale. Critical coupling to the resulting nanocomposite layer is accomplished through guidance by a simple analytical model and measurements by spectroscopic ellipsometry. Thereby, a maximized absorption of light exceeding 99% is accomplished, of which up to about 93% occurs in a volume-equivalent thickness of gold of only 1.6 nm. This corresponds to a record effective absorption coefficient of 1.7 × 10(7) cm(-1) in the visible region, far exceeding those of solid metals, graphene, dye monolayers, and thin film solar cell materials. It is more than a factor of 2 higher than that previously obtained using a critically coupled dye J-aggregate, with a peak width exceeding the latter by 1 order of magnitude. These results thereby substantially push the limits for light harvesting in ultrathin, nanoengineered systems.

Full phosphorescent white-light organic light-emitting diodes with improved color stability and efficiency by fine tuning primary emission contributions

Directory of Open Access Journals (Sweden)

Wang Hua

2014-02-01

Full Text Available In this paper, a novel type of white-light organic light emitting diode (OLED with high color stability was reported, in which the yellow-light emission layer of (4,4′-N,N′-dicarbazolebiphenyl (CBP : tris(2-phenylquinoline-C2,N′iridium(III (Ir(2-phq3 was sandwiched by double blue-light emission layers of 1,1-bis-[(di-4-tolylaminopheny1]cyclohexane (TAPC : bis[4,6-(di-fluorophenyl-pyridinato-N,C2′]picolinate (FIrpic and tris[3-(3-pyridylmesityl]borane (3TPYMB:FIrpic. And, it exhibited the maximum current efficiency of 33.1 cd/A, the turn-on voltage at about 3 V and the maximum luminance in excess of 20000 cd/m2. More important, it realized very stable white-light emission, and its CIE(x, y coordinates only shift from (0.34, 0.37 to (0.33, 0.37 as applied voltage increased from 5 V to 12 V. It is believed that the new scheme in emission layer of white-light OLED can fine tune the contribution of primary emission with applied voltage changed, resulting in high quality white-light OLED.

Full phosphorescent white-light organic light-emitting diodes with improved color stability and efficiency by fine tuning primary emission contributions

Energy Technology Data Exchange (ETDEWEB)

Hua, Wang, E-mail: wmsu2008@sinano.ac.cn, E-mail: wanghua001@tyut.edu.cn; Du, Xiaogang [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Su, Wenming, E-mail: wmsu2008@sinano.ac.cn, E-mail: wanghua001@tyut.edu.cn; Zhang, Dongyu [Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China); Lin, Wenjing [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China)

2014-02-15

In this paper, a novel type of white-light organic light emitting diode (OLED) with high color stability was reported, in which the yellow-light emission layer of (4,4{sup ′}-N,N{sup ′}-dicarbazole)biphenyl (CBP) : tris(2-phenylquinoline-C2,N{sup ′})iridium(III) (Ir(2-phq){sub 3}) was sandwiched by double blue-light emission layers of 1,1-bis-[(di-4-tolylamino)pheny1]cyclohexane (TAPC) : bis[4,6-(di-fluorophenyl)-pyridinato-N,C2{sup ′}]picolinate (FIrpic) and tris[3-(3-pyridyl)mesityl]borane (3TPYMB):FIrpic. And, it exhibited the maximum current efficiency of 33.1 cd/A, the turn-on voltage at about 3 V and the maximum luminance in excess of 20000 cd/m{sup 2}. More important, it realized very stable white-light emission, and its CIE(x, y) coordinates only shift from (0.34, 0.37) to (0.33, 0.37) as applied voltage increased from 5 V to 12 V. It is believed that the new scheme in emission layer of white-light OLED can fine tune the contribution of primary emission with applied voltage changed, resulting in high quality white-light OLED.

Full phosphorescent white-light organic light-emitting diodes with improved color stability and efficiency by fine tuning primary emission contributions

Science.gov (United States)

Hua, Wang; Du, Xiaogang; Su, Wenming; Lin, Wenjing; Zhang, Dongyu

2014-02-01

In this paper, a novel type of white-light organic light emitting diode (OLED) with high color stability was reported, in which the yellow-light emission layer of (4,4'-N,N'-dicarbazole)biphenyl (CBP) : tris(2-phenylquinoline-C2,N')iridium(III) (Ir(2-phq)3) was sandwiched by double blue-light emission layers of 1,1-bis-[(di-4-tolylamino)pheny1]cyclohexane (TAPC) : bis[4,6-(di-fluorophenyl)-pyridinato-N,C2']picolinate (FIrpic) and tris[3-(3-pyridyl)mesityl]borane (3TPYMB):FIrpic. And, it exhibited the maximum current efficiency of 33.1 cd/A, the turn-on voltage at about 3 V and the maximum luminance in excess of 20000 cd/m2. More important, it realized very stable white-light emission, and its CIE(x, y) coordinates only shift from (0.34, 0.37) to (0.33, 0.37) as applied voltage increased from 5 V to 12 V. It is believed that the new scheme in emission layer of white-light OLED can fine tune the contribution of primary emission with applied voltage changed, resulting in high quality white-light OLED.

Au@Ag core-shell nanocubes with finely tuned and well-controlled sizes, shell thicknesses, and optical properties.

Science.gov (United States)

Ma, Yanyun; Li, Weiyang; Cho, Eun Chul; Li, Zhiyuan; Yu, Taekyung; Zeng, Jie; Xie, Zhaoxiong; Xia, Younan

2010-11-23

This paper describes a facile method for generating Au@Ag core-shell nanocubes with edge lengths controllable in the range of 13.4-50 nm. The synthesis involved the use of single-crystal, spherical Au nanocrystals of 11 nm in size as the seeds in an aqueous system, with ascorbic acid serving as the reductant and cetyltrimethylammonium chloride (CTAC) as the capping agent. The thickness of the Ag shells could be finely tuned from 1.2 to 20 nm by varying the ratio of AgNO(3) precursor to Au seeds. We also investigated the growth mechanism by examining the effects of seeds (capped by CTAC or cetyltrimethylammonium bromide(CTAB)) and capping agent (CTAC vs CTAB) on both size and shape of the resultant core-shell nanocrystals. Our results clearly indicate that CTAC worked much better than CTAB as a capping agent in both the syntheses of Au seeds and Au@Ag core-shell nanocubes. We further studied the localized surface plasmon resonance properties of the Au@Ag nanocubes as a function of the Ag shell thickness. By comparing with the extinction spectra obtained from theoretical calculations, we derived a critical value of ca. 3 nm for the shell thickness at which the plasmon excitation of the Au cores would be completely screened by the Ag shells. Moreover, these Au@Ag core-shell nanocubes could be converted into Au-based hollow nanostructures containing the original Au seeds in the interiors through a galvanic replacement reaction.

Leaf color is fine-tuned on the solar spectra to avoid strand direct solar radiation.

Science.gov (United States)

Kume, Atsushi; Akitsu, Tomoko; Nasahara, Kenlo Nishida

2016-07-01

The spectral distributions of light absorption rates by intact leaves are notably different from the incident solar radiation spectra, for reasons that remain elusive. Incident global radiation comprises two main components; direct radiation from the direction of the sun, and diffuse radiation, which is sunlight scattered by molecules, aerosols and clouds. Both irradiance and photon flux density spectra differ between direct and diffuse radiation in their magnitude and profile. However, most research has assumed that the spectra of photosynthetically active radiation (PAR) can be averaged, without considering the radiation classes. We used paired spectroradiometers to sample direct and diffuse solar radiation, and obtained relationships between the PAR spectra and the absorption spectra of photosynthetic pigments and organs. As monomers in solvent, the spectral absorbance of Chl a decreased with the increased spectral irradiance (W m(-2) nm(-1)) of global PAR at noon (R(2) = 0.76), and was suitable to avoid strong spectral irradiance (λmax = 480 nm) rather than absorb photon flux density (μmol m(-2) s(-1) nm(-1)) efficiently. The spectral absorption of photosystems and the intact thallus and leaves decreased linearly with the increased spectral irradiance of direct PAR at noon (I dir-max), where the wavelength was within the 450-650 nm range (R(2) = 0.81). The higher-order structure of photosystems systematically avoided the strong spectral irradiance of I dir-max. However, when whole leaves were considered, leaf anatomical structure and light scattering in leaf tissues made the leaves grey bodies for PAR and enabled high PAR use efficiency. Terrestrial green plants are fine-tuned to spectral dynamics of incident solar radiation and PAR absorption is increased in various structural hierarchies.

Neuroelectric Tuning of Cortical Oscillations by Apical Dendrites in Loop Circuits

Directory of Open Access Journals (Sweden)

David LaBerge

2017-06-01

Full Text Available Bundles of relatively long apical dendrites dominate the neurons that make up the thickness of the cerebral cortex. It is proposed that a major function of the apical dendrite is to produce sustained oscillations at a specific frequency that can serve as a common timing unit for the processing of information in circuits connected to that apical dendrite. Many layer 5 and 6 pyramidal neurons are connected to thalamic neurons in loop circuits. A model of the apical dendrites of these pyramidal neurons has been used to simulate the electric activity of the apical dendrite. The results of that simulation demonstrated that subthreshold electric pulses in these apical dendrites can be tuned to specific frequencies and also can be fine-tuned to narrow bandwidths of less than one Hertz (1 Hz. Synchronous pulse outputs from the circuit loops containing apical dendrites can tune subthreshold membrane oscillations of neurons they contact. When the pulse outputs are finely tuned, they function as a local “clock,” which enables the contacted neurons to synchronously communicate with each other. Thus, a shared tuning frequency can select neurons for membership in a circuit. Unlike layer 6 apical dendrites, layer 5 apical dendrites can produce burst firing in many of their neurons, which increases the amplitude of signals in the neurons they contact. This difference in amplitude of signals serves as basis of selecting a sub-circuit for specialized processing (e.g., sustained attention within the typically larger layer 6-based circuit. After examining the sustaining of oscillations in loop circuits and the processing of spikes in network circuits, we propose that cortical functioning can be globally viewed as two systems: a loop system and a network system. The loop system oscillations influence the network system’s timing and amplitude of pulse signals, both of which can select circuits that are momentarily dominant in cortical activity.

Graphene directed architecture of fine engineered nanostructures with electrochemical applications

DEFF Research Database (Denmark)

Hou, Chengyi; Zhang, Minwei; Halder, Arnab

2017-01-01

, and polymers has led to the possibility to create new electroactive and multifunctional nanostructures, which can serve as promising material platforms for electrochemical purposes. However, the precise control and fine-tuning of material structures and properties are still challenging and in demand...... classified nanostructures, including metallic nanostructures, self-assembled organic and supramolecular structures, and fine engineered metal oxides. In these cases, graphene templates either sacrificed during templating synthesis or retained as support for final products. We also discuss remained challenges....... In this review, we aim to highlight some recent efforts devoted to rational design, assembly and fine engineering of electrochemically active nanostructures using graphene or/and its derivatives as soft templates for controlled synthesis and directed growth. We organize the contents according to the chemically...

Magnetically tuned mass dampers for optimal vibration damping of large structures

International Nuclear Information System (INIS)

Bourquin, Frederic; Siegert, Dominique; Caruso, Giovanni; Peigney, Michael

2014-01-01

This paper deals with the theoretical and experimental analysis of magnetically tuned mass dampers, applied to the vibration damping of large structures of civil engineering interest. Two devices are analysed, for which both the frequency tuning ratio and the damping coefficient can be easily and finely calibrated. They are applied for the damping of the vibrations along two natural modes of a mock-up of a bridge under construction. An original analysis, based on the Maxwell receding image method, is developed for estimating the drag force arising inside the damping devices. It also takes into account self-inductance effects, yielding a complex nonlinear dependence of the drag force on the velocity. The analysis highlights the range of velocities for which the drag force can be assumed of viscous type, and shows its dependence on the involved geometrical parameters of the dampers. The model outcomes are then compared to the corresponding experimental calibration curves. A dynamic model of the controlled structure equipped with the two damping devices is presented, and used for the development of original optimization expressions and for determining the corresponding maximum achievable damping. Finally, several experimental results are presented, concerning both the free and harmonically forced vibration damping of the bridge mock-up, and compared to the corresponding theoretical predictions. The experimental results reveal that the maximum theoretical damping performance can be achieved, when both the tuning frequencies and damping coefficients of each device are finely calibrated according to the optimization expressions. (paper)

Process-morphology scaling relations quantify self-organization in capillary densified nanofiber arrays.

Science.gov (United States)

Kaiser, Ashley L; Stein, Itai Y; Cui, Kehang; Wardle, Brian L

2018-02-07

Capillary-mediated densification is an inexpensive and versatile approach to tune the application-specific properties and packing morphology of bulk nanofiber (NF) arrays, such as aligned carbon nanotubes. While NF length governs elasto-capillary self-assembly, the geometry of cellular patterns formed by capillary densified NFs cannot be precisely predicted by existing theories. This originates from the recently quantified orders of magnitude lower than expected NF array effective axial elastic modulus (E), and here we show via parametric experimentation and modeling that E determines the width, area, and wall thickness of the resulting cellular pattern. Both experiments and models show that further tuning of the cellular pattern is possible by altering the NF-substrate adhesion strength, which could enable the broad use of this facile approach to predictably pattern NF arrays for high value applications.

Thermal expansion behavior study of Co nanowire array with in situ x-ray diffraction and x-ray absorption fine structure techniques

Science.gov (United States)

Mo, Guang; Cai, Quan; Jiang, Longsheng; Wang, Wei; Zhang, Kunhao; Cheng, Weidong; Xing, Xueqing; Chen, Zhongjun; Wu, Zhonghua

2008-10-01

In situ x-ray diffraction and x-ray absorption fine structure techniques were used to study the structural change of ordered Co nanowire array with temperature. The results show that the Co nanowires are polycrystalline with hexagonal close packed structure without phase change up until 700 °C. A nonlinear thermal expansion behavior has been found and can be well described by a quadratic equation with the first-order thermal expansion coefficient of 4.3×10-6/°C and the second-order thermal expansion coefficient of 5.9×10-9/°C. The mechanism of this nonlinear thermal expansion behavior is discussed.

NGST fine guidance sensor

Science.gov (United States)

Rowlands, Neil; Hutchings, John; Murowinski, Richard G.; Alexander, Russ

2003-03-01

Instrumentation for the Next Generation Space Telescope (NGST) is currently in the Phase A definition stage. We have developed a concept for the NGST Fine Guidance Sensor or FGS. The FGS is a detector array based imager which resides in the NGST focal plane. We report here on tradeoff studies aimed at defining an overall configuration of the FGS which will meet the performance and interface requirements. A key performance requirement is a noise equivalent angle of 3 milli-arcseconds to be achieved with 95% probability for any pointing of the observatory in the celestial sphere. A key interface requirement is compatibility with the architecture of the Integrated Science Instrument Module (ISIM). The concept developed consists of two independent and redundant FGS modules, each with a 4' x 2' field of view covered by two 2048 x 2048 infrared detector arrays, providing 60 milli-arcsecond sampling. Performance modeling supporting the choice of this architecture and the trade space considered is presented. Each module has a set of readout electronics which perform star detection, pixel-by-pixel correction, and in fine guiding mode, centroid calculation. These readout electronics communicate with the ISIM Command &Data Handling Units where the FGS control software is based. Rationale for this choice of architecture is also presented.

SWNT array resonant gate MOS transistor.

Science.gov (United States)

Arun, A; Campidelli, S; Filoramo, A; Derycke, V; Salet, P; Ionescu, A M; Goffman, M F

2011-02-04

We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated silicon-based motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNT arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young's modulus in the order of 1-10 GPa and ultra-low mass. The resonant frequency can be tuned by the gate voltage and its dependence is well understood within the continuum mechanics framework.

SWNT array resonant gate MOS transistor

International Nuclear Information System (INIS)

Arun, A; Salet, P; Ionescu, A M; Campidelli, S; Filoramo, A; Derycke, V; Goffman, M F

2011-01-01

We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated silicon-based motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNT arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young's modulus in the order of 1-10 GPa and ultra-low mass. The resonant frequency can be tuned by the gate voltage and its dependence is well understood within the continuum mechanics framework.

Imaging spectroscopy using embedded diffractive optical arrays

Science.gov (United States)

Hinnrichs, Michele; Hinnrichs, Bradford

2017-09-01

Pacific Advanced Technology (PAT) has developed an infrared hyperspectral camera based on diffractive optic arrays. This approach to hyperspectral imaging has been demonstrated in all three infrared bands SWIR, MWIR and LWIR. The hyperspectral optical system has been integrated into the cold-shield of the sensor enabling the small size and weight of this infrared hyperspectral sensor. This new and innovative approach to an infrared hyperspectral imaging spectrometer uses micro-optics that are made up of an area array of diffractive optical elements where each element is tuned to image a different spectral region on a common focal plane array. The lenslet array is embedded in the cold-shield of the sensor and actuated with a miniature piezo-electric motor. This approach enables rapid infrared spectral imaging with multiple spectral images collected and processed simultaneously each frame of the camera. This paper will present our optical mechanical design approach which results in an infrared hyper-spectral imaging system that is small enough for a payload on a small satellite, mini-UAV, commercial quadcopter or man portable. Also, an application of how this spectral imaging technology can easily be used to quantify the mass and volume flow rates of hydrocarbon gases. The diffractive optical elements used in the lenslet array are blazed gratings where each lenslet is tuned for a different spectral bandpass. The lenslets are configured in an area array placed a few millimeters above the focal plane and embedded in the cold-shield to reduce the background signal normally associated with the optics. The detector array is divided into sub-images covered by each lenslet. We have developed various systems using a different number of lenslets in the area array. Depending on the size of the focal plane and the diameter of the lenslet array will determine the number of simultaneous different spectral images collected each frame of the camera. A 2 x 2 lenslet array will image

Listeria monocytogenes CadC Regulates Cadmium Efflux and Fine-tunes Lipoprotein Localization to Escape the Host Immune Response and Promote Infection.

Science.gov (United States)

Pombinho, Rita; Camejo, Ana; Vieira, Ana; Reis, Olga; Carvalho, Filipe; Almeida, Maria Teresa; Pinheiro, Jorge Campos; Sousa, Sandra; Cabanes, Didier

2017-05-01

Listeria monocytogenes is a major intracellular human foodborne bacterial pathogen. We previously revealed L. monocytogenes cadC as highly expressed during mouse infection. Here we show that L. monocytogenes CadC is a sequence-specific, DNA-binding and cadmium-dependent regulator of CadA, an efflux pump conferring cadmium resistance. CadC but not CadA is required for L. monocytogenes infection in vivo. Interestingly, CadC also directly represses lspB, a gene encoding a lipoprotein signal peptidase whose expression appears detrimental for infection. lspB overexpression promotes the release of the LpeA lipoprotein to the extracellular medium, inducing tumor necrosis factor α and interleukin 6 expression, thus impairing L. monocytogenes survival in macrophages. We propose that L. monocytogenes uses CadC to repress lspB expression during infection to avoid LpeA exposure to the host immune system, diminishing inflammatory cytokine expression and promoting intramacrophagic survival and virulence. CadC appears as the first metal efflux pump regulator repurposed during infection to fine-tune lipoprotein processing and host responses. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Nano-pyramid arrays for nano-particle trapping

NARCIS (Netherlands)

Sun, Xingwu; Veltkamp, Henk-Willem; Berenschot, Johan W.; Gardeniers, Johannes G.E.; Tas, Niels Roelof

2016-01-01

Abstract In this paper we present the drastic miniaturization of nano-wire pyramids fabricated by corner lithography. A particle trapping device was fabricated in a well-defined and symmetrical array. The entrance and exit hole-size can be tuned by adjusting fabrication parameters. We describe here

Macromolecular scaffolding: the relationship between nanoscale architecture and function in multichromophoric arrays for organic electronics.

Science.gov (United States)

Palermo, Vincenzo; Schwartz, Erik; Finlayson, Chris E; Liscio, Andrea; Otten, Matthijs B J; Trapani, Sara; Müllen, Klaus; Beljonne, David; Friend, Richard H; Nolte, Roeland J M; Rowan, Alan E; Samorì, Paolo

2010-02-23

The optimization of the electronic properties of molecular materials based on optically or electrically active organic building blocks requires a fine-tuning of their self-assembly properties at surfaces. Such a fine-tuning can be obtained on a scale up to 10 nm by mastering principles of supramolecular chemistry, i.e., by using suitably designed molecules interacting via pre-programmed noncovalent forces. The control and fine-tuning on a greater length scale is more difficult and challenging. This Research News highlights recent results we obtained on a new class of macromolecules that possess a very rigid backbone and side chains that point away from this backbone. Each side chain contains an organic semiconducting moiety, whose position and electronic interaction with neighboring moieties are dictated by the central macromolecular scaffold. A combined experimental and theoretical approach has made it possible to unravel the physical and chemical properties of this system across multiple length scales. The (opto)electronic properties of the new functional architectures have been explored by constructing prototypes of field-effect transistors and solar cells, thereby providing direct insight into the relationship between architecture and function.

PhMYB4 fine-tunes the floral volatile signature of Petunia x hybrida through PhC4H.

Science.gov (United States)

Colquhoun, Thomas A; Kim, Joo Young; Wedde, Ashlyn E; Levin, Laura A; Schmitt, Kyle C; Schuurink, Robert C; Clark, David G

2011-01-01

In Petunia × hybrida cv 'Mitchell Diploid' (MD), floral volatile benzenoid/phenylpropanoid (FVBP) biosynthesis is controlled spatially, developmentally, and daily at molecular, metabolic, and biochemical levels. Multiple genes have been shown to encode proteins that either directly catalyse a biochemical reaction yielding FVBP compounds or are involved in metabolite flux prior to the formation of FVBP compounds. It was hypothesized that multiple transcription factors are involved in the precise regulation of all necessary genes, resulting in the specific volatile signature of MD flowers. After acquiring all available petunia transcript sequences with homology to Arabidopsis thaliana R2R3-MYB transcription factors, PhMYB4 (named for its close identity to AtMYB4) was identified, cloned, and characterized. PhMYB4 transcripts accumulate to relatively high levels in floral tissues at anthesis and throughout open flower stages, which coincides with the spatial and developmental distribution of FVBP production and emission. Upon RNAi suppression of PhMYB4 (ir-PhMYB4) both petunia cinnamate-4-hydroxylase (PhC4H1 and PhC4H2) gene transcript levels were significantly increased. In addition, ir-PhMYB4 plants emit higher levels of FVBP compounds derived from p-coumaric acid (isoeugenol and eugenol) compared with MD. Together, these results indicate that PhMYB4 functions in the repression of C4H transcription, indirectly controlling the balance of FVBP production in petunia floral tissue (i.e. fine-tunes).

Capacitive micromachined ultrasonic transducer arrays as tunable acoustic metamaterials

Energy Technology Data Exchange (ETDEWEB)

Lani, Shane W., E-mail: shane.w.lani@gmail.com, E-mail: karim.sabra@me.gatech.edu, E-mail: levent.degertekin@me.gatech.edu; Sabra, Karim G. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405 (United States); Wasequr Rashid, M.; Hasler, Jennifer [School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250 (United States); Levent Degertekin, F. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405 (United States); School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250 (United States)

2014-02-03

Capacitive Micromachined Ultrasonic Transducers (CMUTs) operating in immersion support dispersive evanescent waves due to the subwavelength periodic structure of electrostatically actuated membranes in the array. Evanescent wave characteristics also depend on the membrane resonance which is modified by the externally applied bias voltage, offering a mechanism to tune the CMUT array as an acoustic metamaterial. The dispersion and tunability characteristics are examined using a computationally efficient, mutual radiation impedance based approach to model a finite-size array and realistic parameters of variation. The simulations are verified, and tunability is demonstrated by experiments on a linear CMUT array operating in 2-12 MHz range.

Bottom-up photonic crystal approach with top-down defect and heterostructure fine-tuning.

Science.gov (United States)

Ding, Tao; Song, Kai; Clays, Koen; Tung, Chen-Ho

2010-03-16

We combine the most efficient (chemical) approach toward three-dimensional photonic crystals with the most convenient (physical) technique for creating non-close-packed crystalline structures. Self-assembly of colloidal particles in artificial opals is followed by a carefully tuned plasma etching treatment. By covering the resulting top layer of more open structure with original dense opal, embedded defect layers and heterostructures can be conveniently designed for advanced photonic band gap and band edge engineering.

Orientation tuning of contrast masking caused by motion streaks.

Science.gov (United States)

Apthorp, Deborah; Cass, John; Alais, David

2010-08-01

We investigated whether the oriented trails of blur left by fast-moving dots (i.e., "motion streaks") effectively mask grating targets. Using a classic overlay masking paradigm, we varied mask contrast and target orientation to reveal underlying tuning. Fast-moving Gaussian blob arrays elevated thresholds for detection of static gratings, both monoptically and dichoptically. Monoptic masking at high mask (i.e., streak) contrasts is tuned for orientation and exhibits a similar bandwidth to masking functions obtained with grating stimuli (∼30 degrees). Dichoptic masking fails to show reliable orientation-tuned masking, but dichoptic masks at very low contrast produce a narrowly tuned facilitation (∼17 degrees). For iso-oriented streak masks and grating targets, we also explored masking as a function of mask contrast. Interestingly, dichoptic masking shows a classic "dipper"-like TVC function, whereas monoptic masking shows no dip and a steeper "handle". There is a very strong unoriented component to the masking, which we attribute to transiently biased temporal frequency masking. Fourier analysis of "motion streak" images shows interesting differences between dichoptic and monoptic functions and the information in the stimulus. Our data add weight to the growing body of evidence that the oriented blur of motion streaks contributes to the processing of fast motion signals.

SWNT array resonant gate MOS transistor

Energy Technology Data Exchange (ETDEWEB)

Arun, A; Salet, P; Ionescu, A M [NanoLab, Ecole Polytechnique Federale de Lausanne, CH-1015, Lausanne (Switzerland); Campidelli, S; Filoramo, A; Derycke, V; Goffman, M F, E-mail: marcelo.goffman@cea.fr [Laboratoire d' Electronique Moleculaire, SPEC (CNRS URA 2454), IRAMIS, CEA, Gif-sur-Yvette (France)

2011-02-04

We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated silicon-based motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNT arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young's modulus in the order of 1-10 GPa and ultra-low mass. The resonant frequency can be tuned by the gate voltage and its dependence is well understood within the continuum mechanics framework.

Tuned Liquid Dampers for the New European Court of Justice, Luxembourg

DEFF Research Database (Denmark)

Georgakis, Christos; Koss, Hans Holger

2005-01-01

As a consequence of their unique positioning and 3,5:1 plan ratio, the proposed twin 103m buildings of the latest expansion of the European Court of Justice (Luxembourg) led to the commissioning of a comprehensive set of wind-tunnel tests. Experimental testing and numerical analyses showed...... the buildings to be susceptible to unacceptably large wind-induced accelerations at the top levels. To mitigate these vibrations, a Tuned Liquid Damper (TLD) array is proposed and designed for both buildings. With an optimal design of the TLD array, total maximum reductions in top-level accelerations are found...

Performance tuning for CUDA-accelerated neighborhood denoising filters

Energy Technology Data Exchange (ETDEWEB)

Zheng, Ziyi; Mueller, Klaus [Stony Brook Univ., NY (United States). Center for Visual Computing, Computer Science; Xu, Wei

2011-07-01

Neighborhood denoising filters are powerful techniques in image processing and can effectively enhance the image quality in CT reconstructions. In this study, by taking the bilateral filter and the non-local mean filter as two examples, we discuss their implementations and perform fine-tuning on the targeted GPU architecture. Experimental results show that the straightforward GPU-based neighborhood filters can be further accelerated by pre-fetching. The optimized GPU-accelerated denoising filters are ready for plug-in into reconstruction framework to enable fast denoising without compromising image quality. (orig.)

Resonance spectra of diabolo optical antenna arrays

Directory of Open Access Journals (Sweden)

Hong Guo

2015-10-01

Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

Geometrical and fluidic tuning of periodically modulated thin metal films

DEFF Research Database (Denmark)

Gilardi, Giovanni; Xiao, Sanshui; Beccherelli, Romeo

2012-01-01

We numerically demonstrate near-zero transmission of light through two-dimensional arrays of isolated gold rings. The analysis of the device as an optofluidic sensor is presented to demonstrate the tuning of the device in relation to variations of volume and refractive index of an isotropic fluid...... positioned over the structure. We also evaluate the performance of the device with respect to geometrical parameters of the rings....

Active resonance tuning of stretchable plasmonic structures

DEFF Research Database (Denmark)

Zhu, Xiaolong; Xiao, Sanshui; Mortensen, N. Asger

2012-01-01

Active resonance tuning is highly desired for the applications of plasmonic structures, such as optical switches and surface enhanced Raman substrates. In this paper, we demonstrate the active tunable plasmonic structures, which composed of monolayer arrays of metallic semishells with dielectric...... cores on stretchable elastic substrates. These composite structures support Bragg-type surface plasmon resonances whose frequencies are sensitive to the arrangement of the metallic semishells. Under uniaxial stretching, the lattice symmetry of these plasmonic structures can be reconfigured from...... applications of the stretch-tunable plasmonic structures in sensing, switching, and filtering....

ΔF = 2 observables and fine-tuning in a warped extra dimension with custodial protection

International Nuclear Information System (INIS)

Blanke, Monika; Buras, Andrzej J.; Duling, Bjoern; Gori, Stefania; Weiler, Andreas

2009-01-01

We present a complete study of ΔS = 2 and ΔB = 2 processes in a warped extra dimensional model with a custodial protection of Zb L b-bar L , including ε K , ΔM K , ΔM s , ΔM d , A SL q , ΔΓ q , A CP (B d →ψK S ) and A CP (B s →ψφ). These processes are affected by tree level contributions from Kaluza-Klein gluons, the heavy KK photon, new heavy electroweak gauge bosons Z H and Z', and in principle by tree level Z contributions. We confirm recent findings that the fully anarchic approach where all the hierarchies in quark masses and weak mixing angles are geometrically explained seems implausible and we confirm that the KK mass scale M KK generically has to be at least ∼ 20 TeV to satisfy the ε K constraint. We point out, however, that there exist regions in parameter space with only modest fine-tuning in the 5D Yukawa couplings which satisfy all existing ΔF = 2 and electroweak precision constraints for scales M KK ≅ 3 TeV in reach of the LHC. Simultaneously we find that A CP (B s → ψφ) and A s SL can be much larger than in the SM as indicated by recent results from CDF and DOe data. We point out that for B d,s physics ΔF = 2 observables the complex (Z H ,Z') can compete with KK gluons, while the tree level Z and KK photon contributions are very small. In particular we point out that the Zd i L d-bar j L couplings are protected by the custodial symmetry. As a by-product we show the relation of the RS flavour model to the Froggatt-Nielsen mechanism and we provide analytic formulae for the effective flavour mixing matrices in terms of the fundamental 5D parameters.

Perspective: Extremely fine tuning of doping enabled by combinatorial molecular-beam epitaxy

Directory of Open Access Journals (Sweden)

J. Wu

2015-06-01

Full Text Available Chemical doping provides an effective method to control the electric properties of complex oxides. However, the state-of-art accuracy in controlling doping is limited to about 1%. This hampers elucidation of the precise doping dependences of physical properties and phenomena of interest, such as quantum phase transitions. Using the combinatorial molecular beam epitaxy, we improve the accuracy in tuning the doping level by two orders of magnitude. We illustrate this novel method by two examples: a systematic investigation of the doping dependence of interface superconductivity, and a study of the competing ground states in the vicinity of the insulator-to-superconductor transition.

Evaluation of heart tissue viability under redox-magnetohydrodynamics conditions: toward fine-tuning flow in biological microfluidics applications.

Science.gov (United States)

Cheah, Lih Tyng; Fritsch, Ingrid; Haswell, Stephen J; Greenman, John

2012-07-01

A microfluidic system containing a chamber for heart tissue biopsies, perfused with Krebs-Henseleit buffer containing glucose and antibiotic (KHGB) using peristaltic pumps and continuously stimulated, was used to evaluate tissue viability under redox-magnetohydrodynamics (redox-MHD) conditions. Redox-MHD possesses unique capabilities to control fluid flow using ionic current from oxidation and reduction processes at electrodes in a magnetic field, making it attractive to fine-tune fluid flow around tissues for "tissue-on-a-chip" applications. The manuscript describes a parallel setup to study two tissue samples simultaneously, and 6-min static incubation with Triton X100. Tissue viability was subsequently determined by assaying perfusate for lactate dehydrogenase (LDH) activity, where LDH serves as an injury marker. Incubation with KHGB containing 5 mM hexaammineruthenium(III) (ruhex) redox species with and without a pair of NdFeB magnets (∼ 0.39 T, placed parallel to the chamber) exhibited no additional tissue insult. MHD fluid flow, viewed by tracking microbeads with microscopy, occurred only when the magnet was present and stimulating electrodes were activated. Pulsating MHD flow with a frequency similar to the stimulating waveform was superimposed over thermal convection (from a hotplate) for Triton-KHGB, but fluid speed was up to twice as fast for ruhex-Triton-KHGB. A large transient ionic current, achieved when switching on the stimulating electrodes, generates MHD perturbations visible over varying peristaltic flow. The well-controlled flow methodology of redox-MHD is applicable to any tissue type, being useful in various drug uptake and toxicity studies, and can be combined equally with on- or off-device analysis modalities. Copyright © 2012 Wiley Periodicals, Inc.

Tuning the band gap in hybrid tin iodide perovskite semiconductors using structural templating.

Science.gov (United States)

Knutson, Jeremy L; Martin, James D; Mitzi, David B

2005-06-27

Structural distortions within the extensive family of organic/inorganic hybrid tin iodide perovskite semiconductors are correlated with their experimental exciton energies and calculated band gaps. The extent of the in- and out-of-plane angular distortion of the SnI4(2-) perovskite sheets is largely determined by the relative charge density and steric requirements of the organic cations. Variation of the in-plane Sn-I-Sn bond angle was demonstrated to have the greatest impact on the tuning of the band gap, and the equatorial Sn-I bond distances have a significant secondary influence. Extended Hückel tight-binding band calculations are employed to decipher the crystal orbital origins of the structural effects that fine-tune the band structure. The calculations suggest that it may be possible to tune the band gap by as much as 1 eV using the templating influence of the organic cation.

MKID digital readout tuning with deep learning

Science.gov (United States)

Dodkins, R.; Mahashabde, S.; O'Brien, K.; Thatte, N.; Fruitwala, N.; Walter, A. B.; Meeker, S. R.; Szypryt, P.; Mazin, B. A.

2018-04-01

Microwave Kinetic Inductance Detector (MKID) devices offer inherent spectral resolution, simultaneous read out of thousands of pixels, and photon-limited sensitivity at optical wavelengths. Before taking observations the readout power and frequency of each pixel must be individually tuned, and if the equilibrium state of the pixels change, then the readout must be retuned. This process has previously been performed through manual inspection, and typically takes one hour per 500 resonators (20 h for a ten-kilo-pixel array). We present an algorithm based on a deep convolution neural network (CNN) architecture to determine the optimal bias power for each resonator. The bias point classifications from this CNN model, and those from alternative automated methods, are compared to those from human decisions, and the accuracy of each method is assessed. On a test feed-line dataset, the CNN achieves an accuracy of 90% within 1 dB of the designated optimal value, which is equivalent accuracy to a randomly selected human operator, and superior to the highest scoring alternative automated method by 10%. On a full ten-kilopixel array, the CNN performs the characterization in a matter of minutes - paving the way for future mega-pixel MKID arrays.

Improvement of Electrochemical Water Oxidation by Fine-Tuning the Structure of Tetradentate N4 Ligands of Molecular Copper Catalysts.

Science.gov (United States)

Shen, Junyu; Wang, Mei; Gao, Jinsuo; Han, Hongxian; Liu, Hong; Sun, Licheng

2017-11-23

Two copper complexes, [(L1)Cu(OH 2 )](BF 4 ) 2 [1; L1=N,N'-dimethyl-N,N'-bis(pyridin-2-ylmethyl)-1,2-diaminoethane] and [(L2)Cu(OH 2 )](BF 4 ) 2 [2, L2=2,7-bis(2-pyridyl)-3,6-diaza-2,6-octadiene], were prepared as molecular water oxidation catalysts. Complex 1 displayed an overpotential (η) of 1.07 V at 1 mA cm -2 and an observed rate constant (k obs ) of 13.5 s -1 at η 1.0 V in pH 9.0 phosphate buffer solution, whereas 2 exhibited a significantly smaller η (0.70 V) to reach 1 mA cm -2 and a higher k obs (50.4 s -1 ) than 1 under identical test conditions. Additionally, 2 displayed better stability than 1 in controlled potential electrolysis experiments with a faradaic efficiency of 94 % for O 2 evolution at 1.58 V, when a casing tube was used for the Pt cathode. A possible mechanism for 1- and 2-catalyzed O 2 evolution reactions is discussed based on the experimental evidence. These comparative results indicate that fine-tuning the structures of tetradentate N 4 ligands can bring about significant change in the performance of copper complexes for electrochemical water oxidation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fine-tuning translation kinetics selection as the driving force of codon usage bias in the hepatitis A virus capsid.

Science.gov (United States)

Aragonès, Lluís; Guix, Susana; Ribes, Enric; Bosch, Albert; Pintó, Rosa M

2010-03-05

Hepatitis A virus (HAV), the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness.

Fine-tuning translation kinetics selection as the driving force of codon usage bias in the hepatitis A virus capsid.

Directory of Open Access Journals (Sweden)

Lluís Aragonès

2010-03-01

Full Text Available Hepatitis A virus (HAV, the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness.

Multilayered membranes with tuned well arrays to be used as regenerative patches.

Science.gov (United States)

Martins, Nádia I; Sousa, Maria P; Custódio, Catarina A; Pinto, Vânia C; Sousa, Paulo J; Minas, Graça; Cleymand, Franck; Mano, João F

2017-07-15

Membranes have been explored as patches in tissue repair and regeneration, most of them presenting a flat geometry or a patterned texture at the nano/micrometer scale. Herein, a new concept of a flexible membrane featuring well arrays forming pore-like environments to accommodate cell culture is proposed. The processing of such membranes using polysaccharides is based on the production of multilayers using the layer-by-layer methodology over a patterned PDMS substrate. The detached multilayered membrane exhibits a layer of open pores at one side and a total thickness of 38±2.2µm. The photolithography technology used to produce the molds allows obtaining wells on the final membranes with a tuned shape and micro-scale precision. The influence of post-processing procedures over chitosan/alginate films with 100 double layers, including crosslinking with genipin or fibronectin immobilization, on the adhesion and proliferation of human osteoblast-like cells is also investigated. The results suggest that the presence of patterned wells affects positively cell adhesion, morphology and proliferation. In particular, it is seen that cells colonized preferentially the well regions. The geometrical features with micro to sub-millimeter patterned wells, together with the nano-scale organization of the polymeric components along the thickness of the film will allow to engineer highly versatile multilayered membranes exhibiting a pore-like microstructure in just one of the sides, that could be adaptable in the regeneration of multiple tissues. Flexible multilayered membranes containing multiple micro-reservoirs are found as potential regenerative patches. Layer-by-layer (LbL) methodology over a featured PDMS substrate is used to produce patterned membranes, composed only by natural-based polymers, that can be easily detached from the PDMS substrate. The combination of nano-scale control of the polymeric organization along the thickness of the chitosan/alginate (CHT

An Accurate CT Saturation Classification Using a Deep Learning Approach Based on Unsupervised Feature Extraction and Supervised Fine-Tuning Strategy

Directory of Open Access Journals (Sweden)

Muhammad Ali

2017-11-01

Full Text Available Current transformer (CT saturation is one of the significant problems for protection engineers. If CT saturation is not tackled properly, it can cause a disastrous effect on the stability of the power system, and may even create a complete blackout. To cope with CT saturation properly, an accurate detection or classification should be preceded. Recently, deep learning (DL methods have brought a subversive revolution in the field of artificial intelligence (AI. This paper presents a new DL classification method based on unsupervised feature extraction and supervised fine-tuning strategy to classify the saturated and unsaturated regions in case of CT saturation. In other words, if protection system is subjected to a CT saturation, proposed method will correctly classify the different levels of saturation with a high accuracy. Traditional AI methods are mostly based on supervised learning and rely heavily on human crafted features. This paper contributes to an unsupervised feature extraction, using autoencoders and deep neural networks (DNNs to extract features automatically without prior knowledge of optimal features. To validate the effectiveness of proposed method, a variety of simulation tests are conducted, and classification results are analyzed using standard classification metrics. Simulation results confirm that proposed method classifies the different levels of CT saturation with a remarkable accuracy and has unique feature extraction capabilities. Lastly, we provided a potential future research direction to conclude this paper.

Fine-granularity electromagnetic calorimeter using plastic scintillator strip-array

International Nuclear Information System (INIS)

Nagano, A.; Yamauchi, S.; Matsunaga, H.; Kim, S.; Matsumoto, T.; Sekiguchi, K.; Uchida, N.; Yamada, Y.; Yamamoto, S.; Evtoukhovitch, P.; Fujii, Y.; Garutti, E.; Iba, S.; Itoh, S.; Kajino, F.; Kalinnikov, V.; Kallies, W.; Kanzaki, J.; Kawagoe, K.; Kishimoto, S.; Miyata, H.; Mzavia, D.; Nakajima, N.; Nakamura, R.; Ono, H.; Samoilov, V.; Sanchez, A.L.C.; Takeshita, T.; Tamura, Y.; Tsamalaidze, Z.

2006-01-01

For the future linear collider calorimetry, fine-granularity is indispensable for energy measurements based on particle flow algorithm, which could achieve better energy resolution for jets than the conventional method. To explore the possibility for such a calorimeter using scintillator, an electromagnetic calorimeter test module, made of scintillator-strips and lead plates, was constructed and tested with test beams. Performance of the test module is presented in this article, in terms of the shower profile studies as well as energy and spatial measurements

Fine tuning of optical transition energy of twisted bilayer graphene via interlayer distance modulation

Czech Academy of Sciences Publication Activity Database

del Corro, Elena; Peňa-Álvarez, Miriam; Sato, K.; Morales-García, A.; Bouša, Milan; Mračko, Michal; Kolman, Radek; Pacáková, Barbara; Kavan, Ladislav; Kalbáč, Martin; Frank, Otakar

2017-01-01

Roč. 95, č. 8 (2017), č. článku 085138. ISSN 2469-9950 R&D Projects: GA ČR GA14-15357S; GA MŠk LL1301; GA ČR GA16-03823S Institutional support: RVO:61388955 ; RVO:61388998 ; RVO:68378271 Keywords : twisted bilayer graphene * tuning * silicon Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

Electrodeposited highly-ordered manganese oxide nanowire arrays for supercapacitors

Science.gov (United States)

Liu, Haifeng; Lu, Bingqiang; Wei, Shuiqiang; Bao, Mi; Wen, Yanxuan; Wang, Fan

2012-07-01

Large arrays of well-aligned Mn oxide nanowires were prepared by electrodeposition using anodic aluminum oxide templates. The sizes of nanowires were tuned by varying the electrotype solution involved and the MnO2 nanowires with 10 μm in length were obtained in a neutral KMnO4 bath for 1 h. MnO2 nanowire arrays grown on conductor substance save the tedious electrode-making process, and electrochemical characterization demonstrates that the MnO2 nanowire arrays electrode has good capacitive behavior. Due to the limited mass transportation in narrow spacing, the spacing effects between the neighbor nanowires have show great influence to the electrochemical performance.

Enhanced photovoltaic performance of an inclined nanowire array solar cell.

Science.gov (United States)

Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

2015-11-30

An innovative solar cell based on inclined p-i-n nanowire array is designed and analyzed. The results show that the inclined geometry can sufficiently increase the conversion efficiency of solar cells by enhancing the absorption of light in the active region. By tuning the nanowire array density, nanowire diameter, nanowire length, as well as the proportion of intrinsic region of the inclined nanowire solar cell, a remarkable efficiency in excess of 16% can be obtained in GaAs. Similar results have been obtained in InP and Si nanowire solar cells, demonstrating the universality of the performance enhancement of inclined nanowire arrays.

Tuning In to Sound: Frequency-Selective Attentional Filter in Human Primary Auditory Cortex

Science.gov (United States)

Da Costa, Sandra; van der Zwaag, Wietske; Miller, Lee M.; Clarke, Stephanie

2013-01-01

Cocktail parties, busy streets, and other noisy environments pose a difficult challenge to the auditory system: how to focus attention on selected sounds while ignoring others? Neurons of primary auditory cortex, many of which are sharply tuned to sound frequency, could help solve this problem by filtering selected sound information based on frequency-content. To investigate whether this occurs, we used high-resolution fMRI at 7 tesla to map the fine-scale frequency-tuning (1.5 mm isotropic resolution) of primary auditory areas A1 and R in six human participants. Then, in a selective attention experiment, participants heard low (250 Hz)- and high (4000 Hz)-frequency streams of tones presented at the same time (dual-stream) and were instructed to focus attention onto one stream versus the other, switching back and forth every 30 s. Attention to low-frequency tones enhanced neural responses within low-frequency-tuned voxels relative to high, and when attention switched the pattern quickly reversed. Thus, like a radio, human primary auditory cortex is able to tune into attended frequency channels and can switch channels on demand. PMID:23365225

Plasma Membrane CRPK1-Mediated Phosphorylation of 14-3-3 Proteins Induces Their Nuclear Import to Fine-Tune CBF Signaling during Cold Response.

Science.gov (United States)

Liu, Ziyan; Jia, Yuxin; Ding, Yanglin; Shi, Yiting; Li, Zhen; Guo, Yan; Gong, Zhizhong; Yang, Shuhua

2017-04-06

In plant cells, changes in fluidity of the plasma membrane may serve as the primary sensor of cold stress; however, the precise mechanism and how the cell transduces and fine-tunes cold signals remain elusive. Here we show that the cold-activated plasma membrane protein cold-responsive protein kinase 1 (CRPK1) phosphorylates 14-3-3 proteins. The phosphorylated 14-3-3 proteins shuttle from the cytosol to the nucleus, where they interact with and destabilize the key cold-responsive C-repeat-binding factor (CBF) proteins. Consistent with this, the crpk1 and 14-3-3κλ mutants show enhanced freezing tolerance, and transgenic plants overexpressing 14-3-3λ show reduced freezing tolerance. Further study shows that CRPK1 is essential for the nuclear translocation of 14-3-3 proteins and for 14-3-3 function in freezing tolerance. Thus, our study reveals that the CRPK1-14-3-3 module transduces the cold signal from the plasma membrane to the nucleus to modulate CBF stability, which ensures a faithfully adjusted response to cold stress of plants. Copyright © 2017 Elsevier Inc. All rights reserved.

Angular tuning of the magnetic birefringence in rippled cobalt films

Energy Technology Data Exchange (ETDEWEB)

Arranz, Miguel A., E-mail: MiguelAngel.Arranz@uclm.es [Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo J. Cela 10, 13071 Ciudad Real (Spain); Colino, José M. [Instituto de Nanociencia, Nanotecnología y Materiales Moleculares, Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas, 45071 Toledo (Spain)

2015-06-22

We report the measurement of magnetically induced birefringence in rippled Co films. For this purpose, the magneto-optical properties of ion beam eroded ferromagnetic films were studied using Kerr magnetometry and magnetic birefringence in the transmitted light intensity. Upon sufficient ion sculpting, these ripple surface nanostructures developed a defined uniaxial anisotropy in the in-plane magnetization, finely tuning the magnetic birefringence effect. We have studied its dependence on the relative orientation between the ripple direction and the magnetic field, and found this effect to be dramatically correlated with the capability to neatly distinguish the mechanisms for the in-plane magnetization reversal, i.e., rotation and nucleation. This double refraction corresponds univocally to the two magnetization axes, parallel and perpendicular to the ripples direction. We have also observed that tuned birefringence in stack assemblies of rippled Co films, which enables us to technically manipulate the number and direction of refraction axes.

Angular tuning of the magnetic birefringence in rippled cobalt films

International Nuclear Information System (INIS)

Arranz, Miguel A.; Colino, José M.

2015-01-01

We report the measurement of magnetically induced birefringence in rippled Co films. For this purpose, the magneto-optical properties of ion beam eroded ferromagnetic films were studied using Kerr magnetometry and magnetic birefringence in the transmitted light intensity. Upon sufficient ion sculpting, these ripple surface nanostructures developed a defined uniaxial anisotropy in the in-plane magnetization, finely tuning the magnetic birefringence effect. We have studied its dependence on the relative orientation between the ripple direction and the magnetic field, and found this effect to be dramatically correlated with the capability to neatly distinguish the mechanisms for the in-plane magnetization reversal, i.e., rotation and nucleation. This double refraction corresponds univocally to the two magnetization axes, parallel and perpendicular to the ripples direction. We have also observed that tuned birefringence in stack assemblies of rippled Co films, which enables us to technically manipulate the number and direction of refraction axes

Towards an autonomous self-tuning vibration energy harvesting device for wireless sensor network applications

International Nuclear Information System (INIS)

Challa, Vinod R; Prasad, M G; Fisher, Frank T

2011-01-01

Future deployment of wireless sensor networks will ultimately require a self-sustainable local power source for each sensor, and vibration energy harvesting is a promising approach for such applications. A requirement for efficient vibration energy harvesting is to match the device and source frequencies. While techniques to tune the resonance frequency of an energy harvesting device have recently been described, in many applications optimization of such systems will require the energy harvesting device to be able to autonomously tune its resonance frequency. In this work a vibration energy harvesting device with autonomous resonance frequency tunability utilizing a magnetic stiffness technique is presented. Here a piezoelectric cantilever beam array is employed with magnets attached to the free ends of cantilever beams to enable magnetic force resonance frequency tuning. The device is successfully tuned from − 27% to + 22% of its untuned resonance frequency while outputting a peak power of approximately 1 mW. Since the magnetic force tuning technique is semi-active, energy is only consumed during the tuning process. The developed prototype consumed maximum energies of 3.3 and 3.9 J to tune to the farthest source frequencies with respect to the untuned resonance frequency of the device. The time necessary for this prototype device to harvest the energy expended during its most energy-intensive (largest resonant frequency adjustment) tuning operation is 88 min in a low amplitude 0.1g vibration environment, which could be further optimized using higher efficiency piezoelectric materials and system components

Individual differences in attention strategies during detection, fine discrimination, and coarse discrimination

Science.gov (United States)

Hecker, Elizabeth A.; Serences, John T.; Srinivasan, Ramesh

2013-01-01

Interacting with the environment requires the ability to flexibly direct attention to relevant features. We examined the degree to which individuals attend to visual features within and across Detection, Fine Discrimination, and Coarse Discrimination tasks. Electroencephalographic (EEG) responses were measured to an unattended peripheral flickering (4 or 6 Hz) grating while individuals (n = 33) attended to orientations that were offset by 0°, 10°, 20°, 30°, 40°, and 90° from the orientation of the unattended flicker. These unattended responses may be sensitive to attentional gain at the attended spatial location, since attention to features enhances early visual responses throughout the visual field. We found no significant differences in tuning curves across the three tasks in part due to individual differences in strategies. We sought to characterize individual attention strategies using hierarchical Bayesian modeling, which grouped individuals into families of curves that reflect attention to the physical target orientation (“on-channel”) or away from the target orientation (“off-channel”) or a uniform distribution of attention. The different curves were related to behavioral performance; individuals with “on-channel” curves had lower thresholds than individuals with uniform curves. Individuals with “off-channel” curves during Fine Discrimination additionally had lower thresholds than those assigned to uniform curves, highlighting the perceptual benefits of attending away from the physical target orientation during fine discriminations. Finally, we showed that a subset of individuals with optimal curves (“on-channel”) during Detection also demonstrated optimal curves (“off-channel”) during Fine Discrimination, indicating that a subset of individuals can modulate tuning optimally for detection and discrimination. PMID:23678013

The CCR4 Deadenylase Acts with Nanos and Pumilio in the Fine-Tuning of Mei-P26 Expression to Promote Germline Stem Cell Self-Renewal

Science.gov (United States)

Joly, Willy; Chartier, Aymeric; Rojas-Rios, Patricia; Busseau, Isabelle; Simonelig, Martine

2013-01-01

Summary Translational regulation plays an essential role in Drosophila ovarian germline stem cell (GSC) biology. GSC self-renewal requires two translational repressors, Nanos (Nos) and Pumilio (Pum), which repress the expression of differentiation factors in the stem cells. The molecular mechanisms underlying this translational repression remain unknown. Here, we show that the CCR4 deadenylase is required for GSC self-renewal and that Nos and Pum act through its recruitment onto specific mRNAs. We identify mei-P26 mRNA as a direct and major target of Nos/Pum/CCR4 translational repression in the GSCs. mei-P26 encodes a protein of the Trim-NHL tumor suppressor family that has conserved functions in stem cell lineages. We show that fine-tuning Mei-P26 expression by CCR4 plays a key role in GSC self-renewal. These results identify the molecular mechanism of Nos/Pum function in GSC self-renewal and reveal the role of CCR4-NOT-mediated deadenylation in regulating the balance between GSC self-renewal and differentiation. PMID:24286029

The CCR4 deadenylase acts with Nanos and Pumilio in the fine-tuning of Mei-P26 expression to promote germline stem cell self-renewal.

Science.gov (United States)

Joly, Willy; Chartier, Aymeric; Rojas-Rios, Patricia; Busseau, Isabelle; Simonelig, Martine

2013-01-01

Translational regulation plays an essential role in Drosophila ovarian germline stem cell (GSC) biology. GSC self-renewal requires two translational repressors, Nanos (Nos) and Pumilio (Pum), which repress the expression of differentiation factors in the stem cells. The molecular mechanisms underlying this translational repression remain unknown. Here, we show that the CCR4 deadenylase is required for GSC self-renewal and that Nos and Pum act through its recruitment onto specific mRNAs. We identify mei-P26 mRNA as a direct and major target of Nos/Pum/CCR4 translational repression in the GSCs. mei-P26 encodes a protein of the Trim-NHL tumor suppressor family that has conserved functions in stem cell lineages. We show that fine-tuning Mei-P26 expression by CCR4 plays a key role in GSC self-renewal. These results identify the molecular mechanism of Nos/Pum function in GSC self-renewal and reveal the role of CCR4-NOT-mediated deadenylation in regulating the balance between GSC self-renewal and differentiation.

Auto-tuning systems for J-PARC LINAC RF cavities

International Nuclear Information System (INIS)

Fang, Z.; Kobayashi, T.; Fukui, Y.; Futatsukawa, K.; Michizono, S.; Yamaguchi, S.; Anami, S.; Suzuki, H.; Sato, F.; Shinozaki, S.; Chishiro, E.

2014-01-01

The 400-MeV proton linear accelerator (LINAC) at the Japan Proton Accelerator Research Complex (J-PARC) consists of 324-MHz low-β and 972-MHz high-β accelerator sections. From October 2006 to May 2013, only the 324-MHz low-β accelerator section was in operation. From the summer of 2013 the J-PARC LINAC was upgraded by installing the 972-MHz high-β accelerator section, and the proton beam was successfully accelerated to 400 MeV in January 2014. Auto-tuning systems for the J-PARC LINAC RF cavities have been successfully developed. A first generation design, an auto-tuning system using a mechanical tuner controller, was developed and operated for the first 3 years. Then the second-generation auto-tuning system was developed using a new approach to the RF cavity warm-up process, and this was applied to the accelerator operation for the subsequent 4 years. During the RF cavity warm-up process in this system, the mechanical tuner is constantly fixed and the input RF frequency is automatically tuned to the cavity resonance frequency using the FPGA (Field-Programmable Gate Array) of the digital feedback RF control system. After the input power level reaches the required value, input RF frequency tuning is stopped and it is switched to the operation frequency. Then, the mechanical tuner control begins operation. This second-generation auto-tuning system was extremely effective for the 324-MHz cavity operation. However, if we apply this approach to the 972-MHz RF cavities, an interlock due to the RF cavity reflection amplitude occasionally occurs at the end of the warm-up process. In order to solve this problem a third generation novel auto-tuning system was successfully developed in December 2013 and applied to the operation of the J-PARC LINAC, including the 972-MHz ACS RF cavities. During the warm-up process both the mechanical tuner controller and the input RF frequency tuning are in operation, and good matching between the input RF frequency and the RF cavity is

Auto-tuning systems for J-PARC LINAC RF cavities

Energy Technology Data Exchange (ETDEWEB)

Fang, Z., E-mail: fang@post.kek.jp [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Kobayashi, T.; Fukui, Y.; Futatsukawa, K.; Michizono, S.; Yamaguchi, S.; Anami, S. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Suzuki, H.; Sato, F.; Shinozaki, S.; Chishiro, E. [Japan Atomic Energy Agency (JAEA), 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

2014-12-11

The 400-MeV proton linear accelerator (LINAC) at the Japan Proton Accelerator Research Complex (J-PARC) consists of 324-MHz low-β and 972-MHz high-β accelerator sections. From October 2006 to May 2013, only the 324-MHz low-β accelerator section was in operation. From the summer of 2013 the J-PARC LINAC was upgraded by installing the 972-MHz high-β accelerator section, and the proton beam was successfully accelerated to 400 MeV in January 2014. Auto-tuning systems for the J-PARC LINAC RF cavities have been successfully developed. A first generation design, an auto-tuning system using a mechanical tuner controller, was developed and operated for the first 3 years. Then the second-generation auto-tuning system was developed using a new approach to the RF cavity warm-up process, and this was applied to the accelerator operation for the subsequent 4 years. During the RF cavity warm-up process in this system, the mechanical tuner is constantly fixed and the input RF frequency is automatically tuned to the cavity resonance frequency using the FPGA (Field-Programmable Gate Array) of the digital feedback RF control system. After the input power level reaches the required value, input RF frequency tuning is stopped and it is switched to the operation frequency. Then, the mechanical tuner control begins operation. This second-generation auto-tuning system was extremely effective for the 324-MHz cavity operation. However, if we apply this approach to the 972-MHz RF cavities, an interlock due to the RF cavity reflection amplitude occasionally occurs at the end of the warm-up process. In order to solve this problem a third generation novel auto-tuning system was successfully developed in December 2013 and applied to the operation of the J-PARC LINAC, including the 972-MHz ACS RF cavities. During the warm-up process both the mechanical tuner controller and the input RF frequency tuning are in operation, and good matching between the input RF frequency and the RF cavity is

Re-tuning tuned mass dampers using ambient vibration measurements

International Nuclear Information System (INIS)

Hazra, B; Sadhu, A; Narasimhan, S; Lourenco, R

2010-01-01

Deterioration, accidental changes in the operating conditions, or incorrect estimates of the structure modal properties lead to de-tuning in tuned mass dampers (TMDs). To restore optimal performance, it is necessary to estimate the modal properties of the system, and re-tune the TMD to its optimal state. The presence of closely spaced modes and a relatively large amount of damping in the dominant modes renders the process of identification difficult. Furthermore, the process of estimating the modal properties of the bare structure using ambient vibration measurements of the structure with the TMD is challenging. In order to overcome these challenges, a novel identification and re-tuning algorithm is proposed. The process of identification consists of empirical mode decomposition to separate the closely spaced modes, followed by the blind identification of the remaining modes. Algorithms for estimating the fundamental frequency and the mode shape of the primary structure necessary for re-tuning the TMD are proposed. Experimental results from the application of the proposed algorithms to identify and re-tune a laboratory structure TMD system are presented

Adaptive Injection-locking Oscillator Array for RF Spectrum Analysis

International Nuclear Information System (INIS)

Leung, Daniel

2011-01-01

A highly parallel radio frequency receiver using an array of injection-locking oscillators for on-chip, rapid estimation of signal amplitudes and frequencies is considered. The oscillators are tuned to different natural frequencies, and variable gain amplifiers are used to provide negative feedback to adapt the locking band-width with the input signal to yield a combined measure of input signal amplitude and frequency detuning. To further this effort, an array of 16 two-stage differential ring oscillators and 16 Gilbert-cell mixers is designed for 40-400 MHz operation. The injection-locking oscillator array is assembled on a custom printed-circuit board. Control and calibration is achieved by on-board microcontroller.

Chameleon-Inspired Mechanochromic Photonic Films Composed of Non-Close-Packed Colloidal Arrays.

Science.gov (United States)

Lee, Gun Ho; Choi, Tae Min; Kim, Bomi; Han, Sang Hoon; Lee, Jung Min; Kim, Shin-Hyun

2017-11-28

Chameleons use a non-close-packed array of guanine nanocrystals in iridophores to develop and tune skin colors in the full visible range. Inspired by the biological process uncovered in panther chameleons, we designed photonic films containing a non-close-packed face-centered-cubic array of silica particles embedded in an elastomer. The non-close-packed array is formed by interparticle repulsion exerted by solvation layers on the particle surface, which is rapidly captured in the elastomer by photocuring of the dispersion medium. The artificial skin exhibits a structural color that shifts from red to blue under stretching or compression. The separation between inelastic particles enables tuning without experiencing significant rearrangement of particles, providing elastic deformation and reversible color change, as chameleons do. The simple fabrication procedure consists of film casting and UV irradiation, potentially enabling the continuous high-throughput production. The mechanochromic property of the photonic films enables the visualization of deformation or stress with colors, which is potentially beneficial for various applications, including mechanical sensors, sound-vision transformers, and color display.

Accurate, model-based tuning of synthetic gene expression using introns in S. cerevisiae.

Directory of Open Access Journals (Sweden)

Ido Yofe

2014-06-01

Full Text Available Introns are key regulators of eukaryotic gene expression and present a potentially powerful tool for the design of synthetic eukaryotic gene expression systems. However, intronic control over gene expression is governed by a multitude of complex, incompletely understood, regulatory mechanisms. Despite this lack of detailed mechanistic understanding, here we show how a relatively simple model enables accurate and predictable tuning of synthetic gene expression system in yeast using several predictive intron features such as transcript folding and sequence motifs. Using only natural Saccharomyces cerevisiae introns as regulators, we demonstrate fine and accurate control over gene expression spanning a 100 fold expression range. These results broaden the engineering toolbox of synthetic gene expression systems and provide a framework in which precise and robust tuning of gene expression is accomplished.

INJECTING FASTENING LOESS SOILS GROZNY FINE PARTICULATE MATTER SUCH AS «MIKRODUR»

Directory of Open Access Journals (Sweden)

S-A. Y. Murtazaev

2014-01-01

Full Text Available The paper is devoted to the actual problem of development and implementation of effective ways to increase the bearing capacity of foundations of buildings and structures by impregnating the soil very finely dispersed binders such as "Mikrodur", turning it into a constructive element of the structure.The article shows that the use of a fine binder improves impervious properties strengthened by arrays, resistance to aggressive influences, hardening in a negative temperature, the strength development, etc. 

Voltage splay modes and enhanced phase locking in a modified linear Josephson array

Science.gov (United States)

Harris, E. B.; Garland, J. C.

1997-02-01

We analyze a modified linear Josephson-junction array in which additional unbiased junctions are used to greatly enhance phase locking. This geometry exhibits strong correlated behavior, with an external magnetic field tuning the voltage splay angle between adjacent Josephson oscillators. The array displays a coherent in-phase mode for f=, where f is the magnetic frustration, while for 0tolerant of critical current disorder approaching 100%. The stability of the array has also been studied by computing Floquet exponents. These exponents are found to be negative for all array lengths, with a 1/N2 dependence, N being the number of series-connected junctions.

Tune-Based Halo Diagnostics

International Nuclear Information System (INIS)

Cameron, Peter

2003-01-01

Tune-based halo diagnostics can be divided into two categories -- diagnostics for halo prevention, and diagnostics for halo measurement. Diagnostics for halo prevention are standard fare in accumulators, synchrotrons, and storage rings, and again can be divided into two categories -- diagnostics to measure the tune distribution (primarily to avoid resonances), and diagnostics to identify instabilities (which will not be discussed here). These diagnostic systems include kicked (coherent) tune measurement, phase-locked loop (PLL) tune measurement, Schottky tune measurement, beam transfer function (BTF) measurements, and measurement of transverse quadrupole mode envelope oscillations. We refer briefly to tune diagnostics used at RHIC and intended for the SNS, and then present experimental results. Tune-based diagnostics for halo measurement (as opposed to prevention) are considerably more difficult. We present one brief example of tune-based halo measurement

Development of high-polarization Fe/Ge neutron polarizing supermirror: Possibility of fine-tuning of scattering length density in ion beam sputtering

Science.gov (United States)

Maruyama, R.; Yamazaki, D.; Akutsu, K.; Hanashima, T.; Miyata, N.; Aoki, H.; Takeda, M.; Soyama, K.

2018-04-01

The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. Bundesmann et al. (2015) have shown that the implantation of primary Ar ions backscattered at the target is responsible for the incorporation of Ar particles and that the fraction increases with increasing ion incidence angle and increasing polar emission angle. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with m = 5 fabricated under the same condition showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the qz range where the correction for the polarization inefficiencies of the beamline works properly. The result of the polarized neutron reflectivity measurement suggests that the "magnetically-dead" layers formed at both sides of the Fe layer, together with the SLD contrast, play a critical role in determining the polarization performance of a polarizing supermirror.

Dynamical Upheaval in Ice Giant Formation: A Solution to the Fine-tuning Problem in the Formation Story

Science.gov (United States)

Frelikh, Renata; Murray-Clay, Ruth

2018-04-01

We report on our recent theoretical work, where we suggest that a protoplanetary disk dynamical instability may have played a crucial role in determining the atmospheric size of the solar system’s ice giants. In contrast to the gas giants, the intermediate-size ice giants never underwent runaway gas accretion in a full gas disk. However, as their substantial core masses are comparable to those of the gas giants, they would have gone runaway, given enough time. In the standard scenario, the ice giants stay at roughly their current size for most of the disk lifetime, undergoing period of slow gas accretion onto ~full-sized cores that formed early-on. The gas disk dissipates before the ice giants accumulate too much gas, but we believe this is fine tuned. A considerable amount of solids is observed in outer disks in mm-to-cm sized particles (pebbles). Assisted by gas drag, these pebbles rapidly accrete onto cores. This would cause the growing ice giants to exceed their current core masses, and quickly turn into gas giants. To resolve this problem, we propose that Uranus and Neptune stayed small for the bulk of the disk lifetime. They only finished their core and atmospheric growth in a short timeframe just as the disk gas dissipated, accreting most of their gas from a disk depleted to ~1% of its original mass. The ice giants have atmospheric mass fractions comparable to the disk gas-to-solid ratio of this depleted disk. This coincides with a disk dynamical upheaval onset by the depletion of gas. We propose that the cores started growing closer-in, where they were kept small by proximity to Jupiter and Saturn. As the gas cleared, the cores were kicked out by the gas giants. Then, they finished their core growth and accreted their atmospheres from the remaining, sparse gas at their current locations. We predict that the gas giants may play a key role in forming intermediate-size atmospheres in the outer disk.

Enhancing long-term memory with stimulation tunes visual attention in one trial.

Science.gov (United States)

Reinhart, Robert M G; Woodman, Geoffrey F

2015-01-13

Scientists have long proposed that memory representations control the mechanisms of attention that focus processing on the task-relevant objects in our visual field. Modern theories specifically propose that we rely on working memory to store the object representations that provide top-down control over attentional selection. Here, we show that the tuning of perceptual attention can be sharply accelerated after 20 min of noninvasive brain stimulation over medial-frontal cortex. Contrary to prevailing theories of attention, these improvements did not appear to be caused by changes in the nature of the working memory representations of the search targets. Instead, improvements in attentional tuning were accompanied by changes in an electrophysiological signal hypothesized to index long-term memory. We found that this pattern of effects was reliably observed when we stimulated medial-frontal cortex, but when we stimulated posterior parietal cortex, we found that stimulation directly affected the perceptual processing of the search array elements, not the memory representations providing top-down control. Our findings appear to challenge dominant theories of attention by demonstrating that changes in the storage of target representations in long-term memory may underlie rapid changes in the efficiency with which humans can find targets in arrays of objects.

Tuning Light Emission of a Pressure-Sensitive Silicon/ZnO Nanowires Heterostructure Matrix through Piezo-phototronic Effects.

Science.gov (United States)

Chen, Mengxiao; Pan, Caofeng; Zhang, Taiping; Li, Xiaoyi; Liang, Renrong; Wang, Zhong Lin

2016-06-28

Based on white light emission at silicon (Si)/ZnO hetrerojunction, a pressure-sensitive Si/ZnO nanowires heterostructure matrix light emitting diode (LED) array is developed. The light emission intensity of a single heterostructure LED is tuned by external strain: when the applied stress keeps increasing, the emission intensity first increases and then decreases with a maximum value at a compressive strain of 0.15-0.2%. This result is attributed to the piezo-phototronic effect, which can efficiently modulate the LED emission intensity by utilizing the strain-induced piezo-polarization charges. It could tune the energy band diagrams at the junction area and regulate the optoelectronic processes such as charge carriers generation, separation, recombination, and transport. This study achieves tuning silicon based devices through piezo-phototronic effect.

Pore radius fine tuning of a silica matrix (MCM-41) based on the synthesis of alumina nanolayers with different thicknesses by atomic layer deposition

International Nuclear Information System (INIS)

Zemtsova, Elena G.; Arbenin, Andrei Yu.; Plotnikov, Alexander F.; Smirnov, Vladimir M.

2015-01-01

The authors investigated a new approach to modify the surface of the mesoporous silica matrix MCM-41. This approach is based on manipulating the chemical composition of the porous surface layer and also on fine tuning the pore radius by applying the atomic layer deposition (ALD) technique. The synthesis of alumina nanolayers was performed on the planar and the porous matrix (MCM-41) by the ALD technique using aluminum tri-sec-butoxide and water as precursors. The authors show that one cycle on silicon, using aluminum tri-sec-butoxide and water as precursors, results in a 1–1.2 Å increase in alumina nanolayer thickness. This is comparable to the increase in thickness per cycle for other precursors such as trimethylaluminum and aluminum chloride. The authors show that the synthesis of an Al 2 O 3 nanolayer on the pore surface of the mesoporous silica matrix MCM-41 by the ALD technique results in a regular change in the porous structure of the samples. The specific porosity (ml/g) of the MCM-41 was 0.95 and that of MCM-41 after 5 ALD cycles was 0.39. The pore diameter (nm) of MCM-41 was 3.3 and that of MCM-41 after 5 ALD cycles was 2.3

Tuning resistance states by thickness control in an electroforming-free nanometallic complementary resistance random access memory

Science.gov (United States)

Yang, Xiang; Lu, Yang; Lee, Jongho; Chen, I.-Wei

2016-01-01

Tuning low resistance state is crucial for resistance random access memory (RRAM) that aims to achieve optimal read margin and design flexibility. By back-to-back stacking two nanometallic bipolar RRAMs with different thickness into a complementary structure, we have found that its low resistance can be reliably tuned over several orders of magnitude. Such high tunability originates from the exponential thickness dependence of the high resistance state of nanometallic RRAM, in which electron wave localization in a random network gives rise to the unique scaling behavior. The complementary nanometallic RRAM provides electroforming-free, multi-resistance-state, sub-100 ns switching capability with advantageous characteristics for memory arrays.

Tuning resistance states by thickness control in an electroforming-free nanometallic complementary resistance random access memory

International Nuclear Information System (INIS)

Yang, Xiang; Lu, Yang; Lee, Jongho; Chen, I-Wei

2016-01-01

Tuning low resistance state is crucial for resistance random access memory (RRAM) that aims to achieve optimal read margin and design flexibility. By back-to-back stacking two nanometallic bipolar RRAMs with different thickness into a complementary structure, we have found that its low resistance can be reliably tuned over several orders of magnitude. Such high tunability originates from the exponential thickness dependence of the high resistance state of nanometallic RRAM, in which electron wave localization in a random network gives rise to the unique scaling behavior. The complementary nanometallic RRAM provides electroforming-free, multi-resistance-state, sub-100 ns switching capability with advantageous characteristics for memory arrays

PERI auto-tuning

Energy Technology Data Exchange (ETDEWEB)

Bailey, D H; Williams, S [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Chame, J; Chen, C; Hall, M [USC/ISI, Marina del Rey, CA 90292 (United States); Dongarra, J; Moore, S; Seymour, K; You, H [University of Tennessee, Knoxville, TN 37996 (United States); Hollingsworth, J K; Tiwari, A [University of Maryland, College Park, MD 20742 (United States); Hovland, P; Shin, J [Argonne National Laboratory, Argonne, IL 60439 (United States)], E-mail: mhall@isi.edu

2008-07-15

The enormous and growing complexity of today's high-end systems has increased the already significant challenges of obtaining high performance on equally complex scientific applications. Application scientists are faced with a daunting challenge in tuning their codes to exploit performance-enhancing architectural features. The Performance Engineering Research Institute (PERI) is working toward the goal of automating portions of the performance tuning process. This paper describes PERI's overall strategy for auto-tuning tools and recent progress in both building auto-tuning tools and demonstrating their success on kernels, some taken from large-scale applications.

Practical tuning for Oracle

International Nuclear Information System (INIS)

Kwon, Sun Yong

2005-02-01

This book deals with tuning for oracle application, which consists of twenty two chapters. These are the contents of this book : what is tuning?, procedure of tuning, collection of performance data using stats pack, collection of performance data in real time, disk IO dispersion, architecture on Index, partition and IOT, optimization of cluster Factor, optimizer, analysis on plan of operation, selection of Index, tuning of Index, parallel processing architecture, DML, analytic function join method, join type, analysis of application, Lock architecture, SGA architecture and wait event and segment tuning.

A self-tuning exact solution and the non-existence of horizons in 5d gravity-scalar system

International Nuclear Information System (INIS)

Zhu Chuan-Jie; Abdus Salam International Centre for Theoretical Physics, Trieste

2000-05-01

We present an exact thick domain wall solution with naked singularities to five dimensional gravity coupled with a scalar field with exponential potential. In our solution we found exactly the special coefficient of the exponent as coming from compactification of string theory with cosmological constant. We show that this solution is self-tuning when a 3-brane is included. In searching for a solution with horizon we found a similar exact solution with fine-tuned exponent coefficient with an integration constant. Failing to find a solution with horizon we prove the non-existence of horizons. These naked singularities actually can't be resolved by horizon. We also comment on the physical relevance of this solution. (author)

APRON: A Cellular Processor Array Simulation and Hardware Design Tool

Science.gov (United States)

Barr, David R. W.; Dudek, Piotr

2009-12-01

We present a software environment for the efficient simulation of cellular processor arrays (CPAs). This software (APRON) is used to explore algorithms that are designed for massively parallel fine-grained processor arrays, topographic multilayer neural networks, vision chips with SIMD processor arrays, and related architectures. The software uses a highly optimised core combined with a flexible compiler to provide the user with tools for the design of new processor array hardware architectures and the emulation of existing devices. We present performance benchmarks for the software processor array implemented on standard commodity microprocessors. APRON can be configured to use additional processing hardware if necessary and can be used as a complete graphical user interface and development environment for new or existing CPA systems, allowing more users to develop algorithms for CPA systems.

APRON: A Cellular Processor Array Simulation and Hardware Design Tool

Directory of Open Access Journals (Sweden)

David R. W. Barr

2009-01-01

Full Text Available We present a software environment for the efficient simulation of cellular processor arrays (CPAs. This software (APRON is used to explore algorithms that are designed for massively parallel fine-grained processor arrays, topographic multilayer neural networks, vision chips with SIMD processor arrays, and related architectures. The software uses a highly optimised core combined with a flexible compiler to provide the user with tools for the design of new processor array hardware architectures and the emulation of existing devices. We present performance benchmarks for the software processor array implemented on standard commodity microprocessors. APRON can be configured to use additional processing hardware if necessary and can be used as a complete graphical user interface and development environment for new or existing CPA systems, allowing more users to develop algorithms for CPA systems.

Charge sharing and charge loss in a cadmium-zinc-telluride fine-pixel detector array

International Nuclear Information System (INIS)

Gaskin, J.A.; Sharma, D.P.; Ramsey, B.D.

2003-01-01

Because of its high atomic number, room temperature operation, low noise, and high spatial resolution a cadmium-zinc-telluride multi-pixel detector is ideal for hard X-ray astrophysical observation. As part of on-going research at MSFC to develop multi-pixel CdZnTe detectors for this purpose, we have measured charge sharing and charge loss for a 4x4 (750 μm pitch), 1 mm thick pixel array and modeled these results using a Monte-Carlo simulation. This model was then used to predict the amount of charge sharing for a much finer pixel array (with a 300 μm pitch). Future work will enable us to compare the simulated results for the finer array to measured values

Specific gut commensal flora locally alters T cell tuning to endogenous ligands.

Science.gov (United States)

Chappert, Pascal; Bouladoux, Nicolas; Naik, Shruti; Schwartz, Ronald H

2013-06-27

Differences in gut commensal flora can dramatically influence autoimmune responses, but the mechanisms behind this are still unclear. We report, in a Th1-cell-driven murine model of autoimmune arthritis, that specific gut commensals, such as segmented filamentous bacteria, have the ability to modulate the activation threshold of self-reactive T cells. In the local microenvironment of gut-associated lymphoid tissues, inflammatory cytokines elicited by the commensal flora dynamically enhanced the antigen responsiveness of T cells that were otherwise tuned down to a systemic self-antigen. Together with subtle differences in early lineage differentiation, this ultimately led to an enhanced recruitment of pathogenic Th1 cells and the development of a more severe form of autoimmune arthritis. These findings define a key role for the gut commensal flora in sustaining ongoing autoimmune responses through the local fine tuning of T-cell-receptor-proximal activation events in autoreactive T cells. Copyright © 2013 Elsevier Inc. All rights reserved.

Amorphous and crystalline TiO2 nanotube arrays for enhanced Li-ion intercalation properties.

Science.gov (United States)

Guan, Dongsheng; Cai, Chuan; Wang, Ying

2011-04-01

We have employed a simple process of anodizing Ti foils to prepare TiO2 nanotube arrays which show enhanced electrochemical properties for applications as Li-ion battery electrode materials. The lengths and pore diameters of TiO2 nanotubes can be finely tuned by varying voltage, electrolyte composition, or anodization time. The as-prepared nanotubes are amorphous and can be converted into anatase nanotubes with heat treatment at 480 degrees C. Rutile crystallites emerge in the anatase nanotube when the annealing temperature is increased to 580 degrees C, resulting in TiO2 nanotubes of mixed phases. The morphological features of nanotubes remain unchanged after annealing. Li-ion insertion performance has been studied for amorphous and crystalline TiO2 nanotube arrays. Amorphous nanotubes with a length of 3.0 microm and an outer diameter of 125 nm deliver a capacity of 91.2 microA h cm(-2) at a current density of 400 microA cm(-2), while those with a length of 25 microm and an outer diameter of 158 nm display a capacity of 533 microA h cm-2. When the 3-microm long nanotubes become crystalline, they deliver lower capacities: the anatase nanotubes and nanotubes of mixed phases show capacities of 53.8 microA h cm-2 and 63.1 microA h cm(-2), respectively at the same current density. The amorphous nanotubes show excellent capacity retention ability over 50 cycles. The cycled nanotubes show little change in morphology compared to the nanotubes before electrochemical cycling. All the TiO2 nanotubes demonstrate higher capacities than amorphous TiO2 compact layer reported in literature. The amorphous TiO2 nanotubes with a length of 1.9 microm exhibit a capacity five times higher than that of TiO2 compact layer even when the nanotube array is cycled at a current density 80 times higher than that for the compact layer. These results suggest that anodic TiO2 nanotube arrays are promising electrode materials for rechargeable Li-ion batteries.

Chemical and biological sensing using tuning forks

Science.gov (United States)

Tao, Nongjian; Boussaad, Salah

2012-07-10

A device for sensing a chemical analyte is disclosed. The device is comprised of a vibrating structure having first and second surfaces and having an associated resonant frequency and a wire coupled between the first and second surfaces of the vibrating structure, wherein the analyte interacts with the wire and causes a change in the resonant frequency of the vibrating structure. The vibrating structure can include a tuning fork. The vibrating structure can be comprised of quartz. The wire can be comprised of polymer. A plurality of vibrating structures are arranged in an array to increase confidence by promoting a redundancy of measurement or to detect a plurality of chemical analytes. A method of making a device for sensing a chemical analyte is also disclosed.

Tuning method for multi-variable control system with PID controllers

International Nuclear Information System (INIS)

Fujiwara, Toshitaka

1983-01-01

Control systems, including thermal and nuclear power plants, generally and mainly use PID controllers consisting of proportional, integral and differential actions. These systems consist of multiple control loops which interfere with each other. Therefore, it is present status that the fine control of the system is carried out by the trial and error method because the adjusting procedure for a single control loop cannot be applied to a multi-loop system in most cases. In this report, a method to effectively adjust PID controller parameters in a short time in a control system which consists of multi-loops that interfere with each other. This method makes adjustment by using the control area as the evaluation function, which is the time-dependent integration of control deviation, the input to the PID controllers. In other words, the evaluation function is provided for each control result for every parameter (gain constant, reset rate, and differentiation time), and all parameters are simultaneously changed in the direction of minimizing the values of these evaluation functions. In the report, the principle of tuning method, the evaluation function for each of three parameters, and the adjusting system configuration for separately using for actual plant tuning and for control system design are described. It also shows the examples of application to the actual tuning of the control system for a thermal power plant and to a control system design. (Wakatsuki, Y.)

Control of magnonic spectra in cobalt nanohole arrays: the effects of density, symmetry and defects

International Nuclear Information System (INIS)

Barman, Anjan

2010-01-01

Magnetic nanohole arrays are important systems for propagation of magnetic excitations and are among the potential candidates for magnonic crystals. A thorough investigation of magnonic band structures and the effect of the geometry of the array on them are important. Here, we present a systematic micromagnetic simulation study of magnonic modes in cobalt nanohole (antidot) arrays. In particular, we investigate the effects of the areal density and symmetry of the array and defects introduced in the array. The magnonic modes are strongly dependent on the density and the symmetry of the array but are weakly dependent on the defects. We have further investigated the modes in a tailored array consisting of equally wide hexagonal arrays with varying density. The magnonic spectrum of the tailored array contains additional modes above the modes of the constituent arrays due to the appearance of irregular domain structures at the regions joining arrays of two different types. This opens up the possibility of tuning the magnonic bands in magnetic nanohole arrays by careful design of the structure of the array.

Tunable absorption resonances in the ultraviolet for InP nanowire arrays.

Science.gov (United States)

Aghaeipour, Mahtab; Anttu, Nicklas; Nylund, Gustav; Samuelson, Lars; Lehmann, Sebastian; Pistol, Mats-Erik

2014-11-17

The ability to tune the photon absorptance spectrum is an attracting way of tailoring the response of devices like photodetectors and solar cells. Here, we measure the reflectance spectra of InP substrates patterned with arrays of vertically standing InP nanowires. Using the reflectance spectra, we calculate and analyze the corresponding absorptance spectra of the nanowires. We show that we can tune absorption resonances for the nanowire arrays into the ultraviolet by decreasing the diameter of the nanowires. When we compare our measurements with electromagnetic modeling, we generally find good agreement. Interestingly, the remaining differences between modeled and measured spectra are attributed to a crystal-phase dependence in the refractive index of InP. Specifically, we find indication of significant differences in the refractive index between the modeled zinc-blende InP nanowires and the measured wurtzite InP nanowires in the ultraviolet. We believe that such crystal-phase dependent differences in the refractive index affect the possibility to excite optical resonances in the large wavelength range of 345 InP nanowire-based solar cells and photodetectors.

Spatial Steering of Cyclotron-Resonance Maser Array Antenna by Magnetic Fields

International Nuclear Information System (INIS)

Kesar, A.; Jerby, E.

2001-01-01

The novel concept of radiation lobe generation and steering by cyclotron-resonance maser (CRM) array is presented. In this scheme the gain and phase of each CRM-element in the array are tuned by magnetic fields which control the cyclotron synchronism condition and the pitch-ratio of each CRM-element. These operating parameters are controlled by the magnetic fields of the solenoid and the kicker, respectively. A numerical example of a CRM-array operating in a gyro-TWT mode is presented. The radiation pattern of a 10-element CRM phased array (15 kV, 1A each) is calculated. The radiation lobe steering by the magnetic field controls is demonstrated in this analysis. A 40 lobe steering range is shown for the 10-element CRM-array at 7.3 GHz. An experimental device is built in our laboratory to demonstrate the active CRM-array antenna concept. Preliminary experimental results of gain and phase-delay of a single CRM-element, as function of electron-beam parameters are presented. These results are compared to the numerical model

SQL Tuning

CERN Document Server

Tow, Dan

2003-01-01

A poorly performing database application not only costs users time, but also has an impact on other applications running on the same computer or the same network. SQL Tuning provides an essential next step for SQL developers and database administrators who want to extend their SQL tuning expertise and get the most from their database applications.There are two basic issues to focus on when tuning SQL: how to find and interpret the execution plan of an SQL statement and how to change SQL to get a specific alternate execution plan. SQL Tuning provides answers to these questions and addresses a third issue that's even more important: how to find the optimal execution plan for the query to use.Author Dan Tow outlines a timesaving method he's developed for finding the optimum execution plan--rapidly and systematically--regardless of the complexity of the SQL or the database platform being used. You'll learn how to understand and control SQL execution plans and how to diagram SQL queries to deduce the best executio...

Design and fabrication of adjustable red-green-blue LED light arrays for plant research

Directory of Open Access Journals (Sweden)

Kenitz J Dustin

2005-08-01

Full Text Available Abstract Background Although specific light attributes, such as color and fluence rate, influence plant growth and development, researchers generally cannot control the fine spectral conditions of artificial plant-growth environments. Plant growth chambers are typically outfitted with fluorescent and/or incandescent fixtures that provide a general spectrum that is accommodating to the human eye and not necessarily supportive to plant development. Many studies over the last several decades, primarily in Arabidopsis thaliana, have clearly shown that variation in light quantity, quality and photoperiod can be manipulated to affect growth and control developmental transitions. Light emitting diodes (LEDs has been used for decades to test plant responses to narrow-bandwidth light. LEDs are particularly well suited for plant growth chambers, as they have an extraordinary life (about 100,000 hours, require little maintenance, and use negligible energy. These factors render LED-based light strategies particularly appropriate for space-biology as well as terrestrial applications. However, there is a need for a versatile and inexpensive LED array platform where individual wavebands can be specifically tuned to produce a series of light combinations consisting of various quantities and qualities of individual wavelengths. Two plans are presented in this report. Results In this technical report we describe the practical construction of tunable red-green-blue LED arrays to support research in plant growth and development. Two light fixture designs and corresponding circuitry are presented. The first is well suited for a laboratory environment for use in a finite area with small plants, such as Arabidopsis. The second is expandable and appropriate for growth chambers. The application of these arrays to early plant developmental studies has been validated with assays of hypocotyl growth inhibition/promotion and phototropic curvature in Arabidopsis seedlings

Wettability control of micropore-array films by altering the surface nanostructures.

Science.gov (United States)

Chang, Chi-Jung; Hung, Shao-Tsu

2010-07-01

By controlling the surface nanostructure, the wettability of films with similar pore-array microstructure can be tuned from hydrophilic to nearly superhydrophobic without variation of the chemical composition. PA1 pore-array film consisting of the horizontal ZnO nanosheets was nearly superhydrophobic. PA2 pore-array film consisting of growth-hindered vertically-aligned ZnO nanorods was hydrophilic. The influences of the nanostructure shape, orientation and the micropore size on the contact angle of the PA1 films were studied. This study provides a new approach to control the wettability of films with similar pore-array structure at the micro-scale by changing their surface nanostructure. PA1 films exhibited irradiation induced reversible wettability transition. The feasibility of creating a wetted radial pattern by selective UV irradiation of PA1 film through a mask with radial pattern and water vapor condensation was also evaluated.

A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

KAUST Repository

Nafe, Ahmed A.; Ghaffar, Farhan A.; Farooqui, Muhammad Fahad; Shamim, Atif

2016-01-01

In this work, we present a novel configuration for realizing monolithic SIW-based phased antenna arrays using Ferrite LTCC technology. Unlike the current common schemes for realizing SIW phased arrays that rely on surface-mount component (p-i-n diodes, etc) for controlling the phase of the individual antenna elements, here the phase is tuned by biasing of the ferrite filling of the SIW. This approach eliminates the need for mounting of any additional RF components and enables seamless monolithic integration of phase shifters and antennas in SIW technology. As a proof of concept, a two-element slotted SIW-based phased array is designed, fabricated and measured. The prototype exhibits a gain of 4.9 dBi at 13.2 GHz and a maximum E-plane beam-scanning of 28 degrees using external windings for biasing the phase shifters. Moreover, the array can achieve a maximum beam-scanning of 19 degrees when biased with small windings that are embedded in the package. This demonstration marks the first time a fully monolithic SIW-based phased array is realized in Ferrite LTCC technology and paves the way for future larger-size implementations.

A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

KAUST Repository

Nafe, Ahmed

2016-11-17

In this work, we present a novel configuration for realizing monolithic SIW-based phased antenna arrays using Ferrite LTCC technology. Unlike the current common schemes for realizing SIW phased arrays that rely on surface-mount component (p-i-n diodes, etc) for controlling the phase of the individual antenna elements, here the phase is tuned by biasing of the ferrite filling of the SIW. This approach eliminates the need for mounting of any additional RF components and enables seamless monolithic integration of phase shifters and antennas in SIW technology. As a proof of concept, a two-element slotted SIW-based phased array is designed, fabricated and measured. The prototype exhibits a gain of 4.9 dBi at 13.2 GHz and a maximum E-plane beam-scanning of 28 degrees using external windings for biasing the phase shifters. Moreover, the array can achieve a maximum beam-scanning of 19 degrees when biased with small windings that are embedded in the package. This demonstration marks the first time a fully monolithic SIW-based phased array is realized in Ferrite LTCC technology and paves the way for future larger-size implementations.

Prospects for quantum computing with an array of ultracold polar paramagnetic molecules.

Science.gov (United States)

Karra, Mallikarjun; Sharma, Ketan; Friedrich, Bretislav; Kais, Sabre; Herschbach, Dudley

2016-03-07

Arrays of trapped ultracold molecules represent a promising platform for implementing a universal quantum computer. DeMille [Phys. Rev. Lett. 88, 067901 (2002)] has detailed a prototype design based on Stark states of polar (1)Σ molecules as qubits. Herein, we consider an array of polar (2)Σ molecules which are, in addition, inherently paramagnetic and whose Hund's case (b) free-rotor pair-eigenstates are Bell states. We show that by subjecting the array to combinations of concurrent homogeneous and inhomogeneous electric and magnetic fields, the entanglement of the array's Stark and Zeeman states can be tuned and the qubit sites addressed. Two schemes for implementing an optically controlled CNOT gate are proposed and their feasibility discussed in the face of the broadening of spectral lines due to dipole-dipole coupling and the inhomogeneity of the electric and magnetic fields.

Voltage splay modes and enhanced phase locking in a modified linear Josephson array

International Nuclear Information System (INIS)

Harris, E.B.; Garland, J.C.

1997-01-01

We analyze a modified linear Josephson-junction array in which additional unbiased junctions are used to greatly enhance phase locking. This geometry exhibits strong correlated behavior, with an external magnetic field tuning the voltage splay angle between adjacent Josephson oscillators. The array displays a coherent in-phase mode for f=(1)/(2), where f is the magnetic frustration, while for 0 p (f)=2aV dc /Φ 0 (1-2f). The locked splay modes are found to be tolerant of critical current disorder approaching 100%. The stability of the array has also been studied by computing Floquet exponents. These exponents are found to be negative for all array lengths, with a 1/N 2 dependence, N being the number of series-connected junctions. copyright 1996 The American Physical Society

Multi-spectral optical absorption in substrate-free nanowire arrays

Energy Technology Data Exchange (ETDEWEB)

Zhang, Junpeng; Chia, Andrew; Boulanger, Jonathan; LaPierre, Ray, E-mail: lapierr@mcmaster.ca [Department of Engineering Physics, McMaster University, 1280 Main St. West, Hamilton, Ontario L8S 4L7 (Canada); Dhindsa, Navneet; Khodadad, Iman; Saini, Simarjeet [Department of Electrical and Computer Engineering, University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1 (Canada); Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1 (Canada)

2014-09-22

A method is presented of fabricating gallium arsenide (GaAs) nanowire arrays of controlled diameter and period by reactive ion etching of a GaAs substrate containing an indium gallium arsenide (InGaP) etch stop layer, allowing the precise nanowire length to be controlled. The substrate is subsequently removed by selective etching, using the same InGaP etch stop layer, to create a substrate-free GaAs nanowire array. The optical absorptance of the nanowire array was then directly measured without absorption from a substrate. We directly observe absorptance spectra that can be tuned by the nanowire diameter, as explained with rigorous coupled wave analysis. These results illustrate strong optical absorption suitable for nanowire-based solar cells and multi-spectral absorption for wavelength discriminating photodetectors. The solar-weighted absorptance above the bandgap of GaAs was 94% for a nanowire surface coverage of only 15%.

A six-degree-of-freedom magnetic levitation fine stage for a high-precision and high-acceleration dual-servo stage

International Nuclear Information System (INIS)

Kim, MyeongHyeon; Jeong, Jae-heon; Gweon, DaeGab; Kim, HyoYoung

2015-01-01

This paper presents a novel six-degree-of-freedom magnetic levitation fine stage for a dual-servo stage. The proposed fine stage is levitated and actuated, using a voice coil motor actuator with a Halbach magnet array. For a dual-servo stage, fine stage performance is deeply intertwined with coarse stage performance. Because the fine stage is installed over the coarse stage, the overall size of the fine stage can be limited by the moving plate of the coarse stage. Therefore, magnetic flux modeling and optimization are performed to manufacture optimal fine stages. To control the fine stage, actuator kinetics and sensor kinematics are proposed. Homing control is implemented by using linear variable differential transformers, whereas fine control is implemented by capacitance sensors and laser interferometers. Finally, experimental results of in-position stability, moving range, and repeatability are presented. (paper)

Fine Structure in Helium-like Fluorine by Fast-Beam Laser Spectroscopy

Science.gov (United States)

Myers, E. G.; Thompson, J. K.; Silver, J. D.

1998-05-01

With the aim of providing an additional precise test of higher-order corrections to high precision calculations of fine structure in helium and helium-like ions(T. Zhang, Z.-C. Yan and G.W.F. Drake, Phys. Rev. Lett. 77), 1715 (1996)., a measurement of the 2^3P_2,F - 2^3P_1,F' fine structure in ^19F^7+ is in progress. The method involves doppler-tuned laser spectroscopy using a CO2 laser on a foil-stripped fluorine ion beam. We aim to achieve a higher precision, compared to an earlier measurement(E.G. Myers, P. Kuske, H.J. Andrae, I.A. Armour, H.A. Klein, J.D. Silver, and E. Traebert, Phys. Rev. Lett. 47), 87 (1981)., by using laser beams parallel and anti-parallel to the ion beam, to obtain partial cancellation of the doppler shift(J.K. Thompson, D.J.H. Howie and E.G. Myers, Phys. Rev. A 57), 180 (1998).. A calculation of the hyperfine structure, allowing for relativistic, QED and nuclear size effects, will be required to obtain the ``hyperfine-free'' fine structure interval from the measurements.

A drone detection with aircraft classification based on a camera array

Science.gov (United States)

Liu, Hao; Qu, Fangchao; Liu, Yingjian; Zhao, Wei; Chen, Yitong

2018-03-01

In recent years, because of the rapid popularity of drones, many people have begun to operate drones, bringing a range of security issues to sensitive areas such as airports and military locus. It is one of the important ways to solve these problems by realizing fine-grained classification and providing the fast and accurate detection of different models of drone. The main challenges of fine-grained classification are that: (1) there are various types of drones, and the models are more complex and diverse. (2) the recognition test is fast and accurate, in addition, the existing methods are not efficient. In this paper, we propose a fine-grained drone detection system based on the high resolution camera array. The system can quickly and accurately recognize the detection of fine grained drone based on hd camera.

Comparison between wire mesh and plate electrodes during Wide-pattern machining on invar fine sheet using through-mask electrochemical micromachining

Energy Technology Data Exchange (ETDEWEB)

Chun, Kwang-ho; Jin, Da-som; Kim, Seong-hyun; Lee, Eun-sang [Inha University, Incheon (Korea, Republic of)

2017-04-15

Many research on the fabrication of Organic light emitting diodes (OLED) shadow masks with high resolution have been carried out because of the development of the smart-display industry. It is the parts of display panel which has millions of micro holes on invar (Fe- Ni) fine sheet. Various techniques such as laser machining, chemical etching and Electrochemical micro-machining (EMM) are used to produce micro-hole arrays. In this study, Through-mask electrochemical machining (TMEMM) combine with portion of photolithography process was applied to fabricate micro-hole arrays on invar fine sheet. The sheet was coated with dry film photoresist. Two types of electrode, plate and mesh, was used to compare the influence of electrode type. The sheet was coated with dry film photoresist with micro- sized through holes. The results were compared in regard to uniformity and taper angle. Compared with the plate electrode, the mesh electrode has better uniformity and taper angle which is important criteria of OLED shadow mask. These results could be used to improve TMEMM for invar fine sheet when it is applied to fabricate micro-hole arrays and help to obtain optical uniformity and desired taper angles.

iTunes music

CERN Document Server

Katz, Bob

2013-01-01

Apple's exciting new Mastered for iTunes (MFiT) initiative, introduced in early 2012, introduces new possibilities for delivering high-quality audio. For the first time, record labels and program producers are encouraged to deliver audio materials to iTunes in a high resolution format, which can produce better-sounding masters. In iTunes Music, author and world-class mastering engineer Bob Katz starts out with the basics, surveys the recent past, and brings you quickly up to the present-where the current state of digital audio is bleak. Katz explains the evolution of

Gold nanostars reshaping and plasmon tuning mechanism

Science.gov (United States)

Kedia, Abhitosh; Kumar, P. Senthil

2013-02-01

Au nanostars are multi-branched nanoparticles with sharp tips which display enhanced plasmonic applications in SERS and nanophotonics. It has already been well documented that polyvinylpyrrolidone (PVP) dispersed in DMF solvent medium act as a unique candidate for realization of this 3-D complex branched metal nanostructures even under normal conditions. Interestingly, controlled addition of propanol to DMF brings about significant changes in the morphology of these gold nanostars visualized through gradual blue shifting of the localized surface plasmon resonance (LSPR) from 920 to 600 nm. Modified interaction between DMF-PVP arising due to introduction of alcohol results in fine tuning of LSPR correlated with corresponding aesthetic changes as clearly evidenced from TEM images. Thus, our ability in synthesizing anisotropic metal nanoparticles with wavelength tunable LSPRs through a simple yet elegant chemical solution synthesis procedure opens up a gamut of new applications in both linear and nonlinear optical spectroscopy.

Optimization of a nanotechnology based antimicrobial platform for food safety applications using Engineered Water Nanostructures (EWNS)

Science.gov (United States)

Pyrgiotakis, Georgios; Vedantam, Pallavi; Cirenza, Caroline; McDevitt, James; Eleftheriadou, Mary; Leonard, Stephen S.; Demokritou, Philip

2016-02-01

A chemical free, nanotechnology-based, antimicrobial platform using Engineered Water Nanostructures (EWNS) was recently developed. EWNS have high surface charge, are loaded with reactive oxygen species (ROS), and can interact-with, and inactivate an array of microorganisms, including foodborne pathogens. Here, it was demonstrated that their properties during synthesis can be fine tuned and optimized to further enhance their antimicrobial potential. A lab based EWNS platform was developed to enable fine-tuning of EWNS properties by modifying synthesis parameters. Characterization of EWNS properties (charge, size and ROS content) was performed using state-of-the art analytical methods. Further their microbial inactivation potential was evaluated with food related microorganisms such as Escherichia coli, Salmonella enterica, Listeria innocua, Mycobacterium parafortuitum, and Saccharomyces cerevisiae inoculated onto the surface of organic grape tomatoes. The results presented here indicate that EWNS properties can be fine-tuned during synthesis resulting in a multifold increase of the inactivation efficacy. More specifically, the surface charge quadrupled and the ROS content increased. Microbial removal rates were microorganism dependent and ranged between 1.0 to 3.8 logs after 45 mins of exposure to an EWNS aerosol dose of 40,000 #/cm3.

Optimization of a nanotechnology based antimicrobial platform for food safety applications using Engineered Water Nanostructures (EWNS)

Science.gov (United States)

Pyrgiotakis, Georgios; Vedantam, Pallavi; Cirenza, Caroline; McDevitt, James; Eleftheriadou, Mary; Leonard, Stephen S.; Demokritou, Philip

2016-01-01

A chemical free, nanotechnology-based, antimicrobial platform using Engineered Water Nanostructures (EWNS) was recently developed. EWNS have high surface charge, are loaded with reactive oxygen species (ROS), and can interact-with, and inactivate an array of microorganisms, including foodborne pathogens. Here, it was demonstrated that their properties during synthesis can be fine tuned and optimized to further enhance their antimicrobial potential. A lab based EWNS platform was developed to enable fine-tuning of EWNS properties by modifying synthesis parameters. Characterization of EWNS properties (charge, size and ROS content) was performed using state-of-the art analytical methods. Further their microbial inactivation potential was evaluated with food related microorganisms such as Escherichia coli, Salmonella enterica, Listeria innocua, Mycobacterium parafortuitum, and Saccharomyces cerevisiae inoculated onto the surface of organic grape tomatoes. The results presented here indicate that EWNS properties can be fine-tuned during synthesis resulting in a multifold increase of the inactivation efficacy. More specifically, the surface charge quadrupled and the ROS content increased. Microbial removal rates were microorganism dependent and ranged between 1.0 to 3.8 logs after 45 mins of exposure to an EWNS aerosol dose of 40,000 #/cm3. PMID:26875817

Optimization of a nanotechnology based antimicrobial platform for food safety applications using Engineered Water Nanostructures (EWNS).

Science.gov (United States)

Pyrgiotakis, Georgios; Vedantam, Pallavi; Cirenza, Caroline; McDevitt, James; Eleftheriadou, Mary; Leonard, Stephen S; Demokritou, Philip

2016-02-15

A chemical free, nanotechnology-based, antimicrobial platform using Engineered Water Nanostructures (EWNS) was recently developed. EWNS have high surface charge, are loaded with reactive oxygen species (ROS), and can interact-with, and inactivate an array of microorganisms, including foodborne pathogens. Here, it was demonstrated that their properties during synthesis can be fine tuned and optimized to further enhance their antimicrobial potential. A lab based EWNS platform was developed to enable fine-tuning of EWNS properties by modifying synthesis parameters. Characterization of EWNS properties (charge, size and ROS content) was performed using state-of-the art analytical methods. Further their microbial inactivation potential was evaluated with food related microorganisms such as Escherichia coli, Salmonella enterica, Listeria innocua, Mycobacterium parafortuitum, and Saccharomyces cerevisiae inoculated onto the surface of organic grape tomatoes. The results presented here indicate that EWNS properties can be fine-tuned during synthesis resulting in a multifold increase of the inactivation efficacy. More specifically, the surface charge quadrupled and the ROS content increased. Microbial removal rates were microorganism dependent and ranged between 1.0 to 3.8 logs after 45 mins of exposure to an EWNS aerosol dose of 40,000 #/cm(3).

Remote tuning of NMR probe circuits.

Science.gov (United States)

Kodibagkar, V D; Conradi, M S

2000-05-01

There are many circumstances in which the probe tuning adjustments cannot be located near the rf NMR coil. These may occur in high-temperature NMR, low-temperature NMR, and in the use of magnets with small diameter access bores. We address here circuitry for connecting a fixed-tuned probe circuit by a transmission line to a remotely located tuning network. In particular, the bandwidth over which the probe may be remotely tuned while keeping the losses in the transmission line acceptably low is considered. The results show that for all resonant circuit geometries (series, parallel, series-parallel), overcoupling of the line to the tuned circuit is key to obtaining a large tuning bandwidth. At equivalent extents of overcoupling, all resonant circuit geometries have nearly equal remote tuning bandwidths. Particularly for the case of low-loss transmission line, the tuning bandwidth can be many times the tuned circuit's bandwidth, f(o)/Q. Copyright 2000 Academic Press.

Plasmonic fluorescence enhancement of DBMBF2 monomers and DBMBF2-toluene exciplexes using al-hole arrays

NARCIS (Netherlands)

Schmidt, T.M.; Bochenkov, V.E.; Espinoza, J.D.A.; Smits, E.C.P.; Muzafarov, A.M.; Kononevich, Y.N.; Sutherland, D.S.

2014-01-01

The optical properties of aluminum hole arrays fabricated via colloidal lithography were investigated. By tuning the hole diameter and hole spacing independently, their influence on the Bloch wave-surface plasmon polariton (BW-SPP) and localized surface plasmon resonances resonances (LSPR) could be

Fine Tuning the CJ Detonation Speed of a High Explosive products Equation of State

Energy Technology Data Exchange (ETDEWEB)

Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-05-12

For high explosive (HE) simulations, inaccuracies of a per cent or two in the detonation wave speed can result from not suficiently resolving the reaction zone width or from small inaccuracies in calibrating the products equation of state (EOS) or from variation of HE lots. More accurate detonation speeds can be obtained by ne tuning the equation of state to compensate. Here we show that two simple EOS transformations can be used to adjust the CJ detonation speed by a couple of per cent with minimal effect on the CJ release isentrope. The two transformations are (1) a shift in the energy origin and (2) a linear scaling of the speci c volume. The effectiveness of the transformations is demonstrated with simulations of the cylinder test for PBX 9502 starting with a products EOS for which the CJ detonation speed is 1 per cent too low.

Real-time neural network-based self-tuning control of a nonlinear electro-hydraulic servomotor

Energy Technology Data Exchange (ETDEWEB)

Canelon, J.I.; Ortega, A.G. [Univ. del Zulia, Maracaibo, Zulia (Venezuela, Bolivarian Republic of). School of Electrical Engineering; Shieh, L.S. [Houston Univ., Houston, TX (United States). Dept. of Electrical and Computer Engineering; Bastidas, J.I. [Univ. del Zulia, Maracaibo, Zulia (Venezuela, Bolivarian Republic of). School of Mechanical Engineering; Zhang, Y.; Akujuobi, C.M. [Prairie View A and M Univ., Prairie View, TX (United States). Center of Excellence for Communication Systems Technology Research and Dept. of Engineering Technology

2010-08-13

For high power applications, hydraulic actuators offer many advantages over electromagnetic actuators, including higher torque/mass ratios; smaller control gains; excellent torque capability; filtered high frequency noise; better heat transfer characteristics; smaller size; higher speed of response of the servomechanism; cheaper hardware; and higher reliability. Therefore, any application that requires a large force applied smoothly by an actuator is a candidate for hydraulic power. Examples of such applications include vehicle steering and braking systems; roll mills; drilling rigs; heavy duty crane and presses; and industrial robots and actuators for aircraft control surfaces such as ailerons and flaps. It is extremely important to create effective control strategies for hydraulic systems. This paper outlined the real-time implementation of a neural network-based approach, for self-tuning control of the angular position of a nonlinear electro-hydraulic servomotor. Using an online training algorithm, a neural network autoregressive moving-average model with exogenous input (ARMAX) model of the system was identified and continuously updated and an optimal linear ARMAX model was determined. The paper briefly depicted the neural network-based self-tuning control approach and a description of the experimental equipment (hardware and software) was presented including the implementation details. The experimental results were discussed and conclusions were summarized. It was found that the approach proved to be very effective in the control of this fast dynamics system, outperforming a fine tuned PI controller. Therefore, although the self-tuning approach was computationally demanding, it was feasible for real-time implementation. 22 refs., 6 figs.

Simultaneous gains tuning in boiler/turbine PID-based controller clusters using iterative feedback tuning methodology.

Science.gov (United States)

Zhang, Shu; Taft, Cyrus W; Bentsman, Joseph; Hussey, Aaron; Petrus, Bryan

2012-09-01

Tuning a complex multi-loop PID based control system requires considerable experience. In today's power industry the number of available qualified tuners is dwindling and there is a great need for better tuning tools to maintain and improve the performance of complex multivariable processes. Multi-loop PID tuning is the procedure for the online tuning of a cluster of PID controllers operating in a closed loop with a multivariable process. This paper presents the first application of the simultaneous tuning technique to the multi-input-multi-output (MIMO) PID based nonlinear controller in the power plant control context, with the closed-loop system consisting of a MIMO nonlinear boiler/turbine model and a nonlinear cluster of six PID-type controllers. Although simplified, the dynamics and cross-coupling of the process and the PID cluster are similar to those used in a real power plant. The particular technique selected, iterative feedback tuning (IFT), utilizes the linearized version of the PID cluster for signal conditioning, but the data collection and tuning is carried out on the full nonlinear closed-loop system. Based on the figure of merit for the control system performance, the IFT is shown to deliver performance favorably comparable to that attained through the empirical tuning carried out by an experienced control engineer. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

A Global Perspective of Fine Particulate Matter Pollution and Its Health Effects.

Science.gov (United States)

Mukherjee, Arideep; Agrawal, Madhoolika

Fine particulate matter (PM) in the ambient air is implicated in a variety of human health issues throughout the globe. Regulation of fine PM in the atmosphere requires information on the dimension of the problem with respect to variations in concentrations and sources. To understand the current status of fine particles in the atmosphere and their potential harmful health effects in different regions of the world this review article was prepared based on peer-reviewed scientific papers, scientific reports, and database from government organizations published after the year 2000 to evaluate the global scenario of the PM 2.5 (particles levels and exceedances of national and international standards were several times higher in Asian countries, while levels in Europe and USA were mostly well below the respective standards. Vehicular traffic has a significant influence on PM 2.5 levels in urban areas; followed by combustion activities (biomass, industrial, and waste burning) and road dust. In urban atmosphere, fine particles are mostly associated with different health effects with old aged people, pregnant women, and more so children being the most susceptible ones. Fine PM chemical constituents severely effect health due to their carcinogenic or mutagenic nature. Most of the research indicated an exceedance of fine PM level of the standards with a diverse array of health effects based on PM 2.5 chemical constituents. Emission reduction policies with epidemiological studies are needed to understand the benefits of sustainable control measures for fine PM mitigation.

Adaptive Self-Tuning Networks

Science.gov (United States)

Knox, H. A.; Draelos, T.; Young, C. J.; Lawry, B.; Chael, E. P.; Faust, A.; Peterson, M. G.

2015-12-01

The quality of automatic detections from seismic sensor networks depends on a large number of data processing parameters that interact in complex ways. The largely manual process of identifying effective parameters is painstaking and does not guarantee that the resulting controls are the optimal configuration settings. Yet, achieving superior automatic detection of seismic events is closely related to these parameters. We present an automated sensor tuning (AST) system that learns near-optimal parameter settings for each event type using neuro-dynamic programming (reinforcement learning) trained with historic data. AST learns to test the raw signal against all event-settings and automatically self-tunes to an emerging event in real-time. The overall goal is to reduce the number of missed legitimate event detections and the number of false event detections. Reducing false alarms early in the seismic pipeline processing will have a significant impact on this goal. Applicable both for existing sensor performance boosting and new sensor deployment, this system provides an important new method to automatically tune complex remote sensing systems. Systems tuned in this way will achieve better performance than is currently possible by manual tuning, and with much less time and effort devoted to the tuning process. With ground truth on detections in seismic waveforms from a network of stations, we show that AST increases the probability of detection while decreasing false alarms.

Kernel Tuning and Nonuniform Influence on Optical and Electrochemical Gaps of Bimetal Nanoclusters.

Science.gov (United States)

He, Lizhong; Yuan, Jinyun; Xia, Nan; Liao, Lingwen; Liu, Xu; Gan, Zibao; Wang, Chengming; Yang, Jinlong; Wu, Zhikun

2018-03-14

Fine tuning nanoparticles with atomic precision is exciting and challenging and is critical for tuning the properties, understanding the structure-property correlation and determining the practical applications of nanoparticles. Some ultrasmall thiolated metal nanoparticles (metal nanoclusters) have been shown to be precisely doped, and even the protecting staple metal atom could be precisely reduced. However, the precise addition or reduction of the kernel atom while the other metal atoms in the nanocluster remain the same has not been successful until now, to the best of our knowledge. Here, by carefully selecting the protecting ligand with adequate steric hindrance, we synthesized a novel nanocluster in which the kernel can be regarded as that formed by the addition of two silver atoms to both ends of the Pt@Ag 12 icosohedral kernel of the Ag 24 Pt(SR) 18 (SR: thiolate) nanocluster, as revealed by single crystal X-ray crystallography. Interestingly, compared with the previously reported Ag 24 Pt(SR) 18 nanocluster, the as-obtained novel bimetal nanocluster exhibits a similar absorption but a different electrochemical gap. One possible explanation for this result is that the kernel tuning does not essentially change the electronic structure, but obviously influences the charge on the Pt@Ag 12 kernel, as demonstrated by natural population analysis, thus possibly resulting in the large electrochemical gap difference between the two nanoclusters. This work not only provides a novel strategy to tune metal nanoclusters but also reveals that the kernel change does not necessarily alter the optical and electrochemical gaps in a uniform manner, which has important implications for the structure-property correlation of nanoparticles.

Electronically Tuned Local Oscillators for the NOEMA Interferometer

Science.gov (United States)

Mattiocco, Francois; Garnier, Olivier; Maier, Doris; Navarrini, Alessandro; Serres, Patrice

2016-03-01

We present an overview of the electronically tuned local oscillator (LO) system developed at the Institut de RadioAstronomie millimetrique (IRAM) for the superconductor-insulator-superconductor (SIS) receivers of the NOrthern Extended Millimeter Array interferometer (NOEMA). We modified the frequency bands and extended the bandwidths of the LO designs developed by the National Radio Astronomy Observatory (NRAO) for the Atacama Large Millimeter Array (ALMA) project to cover the four NOEMA LO frequency ranges 82-108.3 GHz (Band 1), 138.6-171.3 GHz (Band 2), 207.7-264.4 GHz (Band 3), and 283-365 GHz (Band 4). The NOEMA LO system employs commercially available MMICs and GaAs millimeter MMICs from NRAO which are micro-assembled into active multiplied chain (AMC) and power amplifier (PA) modules. We discuss the problem of the LO spurious harmonics and of the LO signal directly multiplied by the SIS mixers that add extra noise and lead to detections of unwanted spectral lines from higher order sidebands. A waveguide filter in the LO path is used to reduce the higher order harmonics level of the LO at the output of the final frequency multiplier, thus mitigating the undesired effects and improving the system noise temperature.

The ATLAS Monte Carlo tuning system

CERN Document Server

Wahrmund, S

2012-01-01

The ATLAS experiment moved the tuning of the underlying event and minimum bias event shape modeling, previously done in a manual fashion, to the automated Professor tuning tool, employed in connection with the Rivet analysis framework, when the first corresponding experimental analysis from LHC became available. The tuning effort for the Pythia 8 generator, which includes improved models for diffraction, has been started in this automated way in ATLAS, with the aim of getting a good description of the pile-up generated by multiple minimum bias interactions. The first results for these Pythia 8 tunes, as well as Pythia 6 shower tunes are presented, including a study of tunes for various PDFs.

SC tuning fork

CERN Document Server

The tuning fork used to modulate the radiofrequency system of the synchro cyclotron (SC) from 1957 to 1973. This piece is an unused spare part. The SC was the 1st accelerator built at CERN. It operated from August 1957 until it was closed down at the end of 1990. In the SC the magnetic field did not change with time, and the particles were accelerated in successive pulses by a radiofrequency voltage of some 20kV which varied in frequency as they spiraled outwards towards the extraction radius. The frequency varied from 30MHz to about 17Mz in each pulse. The tuning fork vibrated at 55MHz in vacuum in an enclosure which formed a variable capacitor in the tuning circuit of the RF system, allowing the RF to vary over the appropriate range to accelerate protons from the centre of the macine up to 600Mev at extraction radius. In operation the tips of the tuning fork blade had an amplitude of movement of over 1 cm. The SC accelerator underwent extensive improvements from 1973 to 1975, including the installation of a...

Mapping the fine structure of cortical activity with different micro-ECoG electrode array geometries

Science.gov (United States)

Wang, Xi; Gkogkidis, C. Alexis; Iljina, Olga; Fiederer, Lukas D. J.; Henle, Christian; Mader, Irina; Kaminsky, Jan; Stieglitz, Thomas; Gierthmuehlen, Mortimer; Ball, Tonio

2017-10-01

Objective. Innovations in micro-electrocorticography (µECoG) electrode array manufacturing now allow for intricate designs with smaller contact diameters and/or pitch (i.e. inter-contact distance) down to the sub-mm range. The aims of the present study were: (i) to investigate whether frequency ranges up to 400 Hz can be reproducibly observed in µECoG recordings and (ii) to examine how differences in topographical substructure between these frequency bands and electrode array geometries can be quantified. We also investigated, for the first time, the influence of blood vessels on signal properties and assessed the influence of cortical vasculature on topographic mapping. Approach. The present study employed two µECoG electrode arrays with different contact diameters and inter-contact distances, which were used to characterize neural activity from the somatosensory cortex of minipigs in a broad frequency range up to 400 Hz. The analysed neural data were recorded in acute experiments under anaesthesia during peripheral electrical stimulation. Main results. We observed that µECoG recordings reliably revealed multi-focal cortical somatosensory response patterns, in which response peaks were often less than 1 cm apart and would thus not have been resolvable with conventional ECoG. The response patterns differed by stimulation site and intensity, they were distinct for different frequency bands, and the results of functional mapping proved independent of cortical vascular. Our analysis of different frequency bands exhibited differences in the number of activation peaks in topographical substructures. Notably, signal strength and signal-to-noise ratios differed between the two electrode arrays, possibly due to their different sensitivity for variations in spatial patterns and signal strengths. Significance. Our findings that the geometry of µECoG electrode arrays can strongly influence their recording performance can help to make informed decisions that maybe

Challenging aspects of contemporary cochlear implant electrode array design.

Science.gov (United States)

Mistrík, Pavel; Jolly, Claude; Sieber, Daniel; Hochmair, Ingeborg

2017-12-01

A design comparison of current perimodiolar and lateral wall electrode arrays of the cochlear implant (CI) is provided. The focus is on functional features such as acoustic frequency coverage and tonotopic mapping, battery consumption and dynamic range. A traumacity of their insertion is also evaluated. Review of up-to-date literature. Perimodiolar electrode arrays are positioned in the basal turn of the cochlea near the modiolus. They are designed to initiate the action potential in the proximity to the neural soma located in spiral ganglion. On the other hand, lateral wall electrode arrays can be inserted deeper inside the cochlea, as they are located along the lateral wall and such insertion trajectory is less traumatic. This class of arrays targets primarily surviving neural peripheral processes. Due to their larger insertion depth, lateral wall arrays can deliver lower acoustic frequencies in manner better corresponding to cochlear tonotopicity. In fact, spiral ganglion sections containing auditory nerve fibres tuned to low acoustic frequencies are located deeper than 1 and half turn inside the cochlea. For this reason, a significant frequency mismatch might be occurring for apical electrodes in perimodiolar arrays, detrimental to speech perception. Tonal languages such as Mandarin might be therefore better treated with lateral wall arrays. On the other hand, closer proximity to target tissue results in lower psychophysical threshold levels for perimodiolar arrays. However, the maximal comfort level is also lower, paradoxically resulting in narrower dynamic range than that of lateral wall arrays. Battery consumption is comparable for both types of arrays. Lateral wall arrays are less likely to cause trauma to cochlear structures. As the current trend in cochlear implantation is the maximal protection of residual acoustic hearing, the lateral wall arrays seem more suitable for hearing preservation CI surgeries. Future development could focus on combining the

A Strategy for Automatic Performance Tuning of Stencil Computations on GPUs

Directory of Open Access Journals (Sweden)

Joseph D. Garvey

2018-01-01

Full Text Available We propose and evaluate a novel strategy for tuning the performance of a class of stencil computations on Graphics Processing Units. The strategy uses a machine learning model to predict the optimal way to load data from memory followed by a heuristic that divides other optimizations into groups and exhaustively explores one group at a time. We use a set of 104 synthetic OpenCL stencil benchmarks that are representative of many real stencil computations. We first demonstrate the need for auto-tuning by showing that the optimization space is sufficiently complex that simple approaches to determining a high-performing configuration fail. We then demonstrate the effectiveness of our approach on NVIDIA and AMD GPUs. Relative to a random sampling of the space, we find configurations that are 12%/32% faster on the NVIDIA/AMD platform in 71% and 4% less time, respectively. Relative to an expert search, we achieve 5% and 9% better performance on the two platforms in 89% and 76% less time. We also evaluate our strategy for different stencil computational intensities, varying array sizes and shapes, and in combination with expert search.

Data Driven Tuning of Inventory Controllers

DEFF Research Database (Denmark)

Huusom, Jakob Kjøbsted; Santacoloma, Paloma Andrade; Poulsen, Niels Kjølstad

2007-01-01

A systematic method for criterion based tuning of inventory controllers based on data-driven iterative feedback tuning is presented. This tuning method circumvent problems with modeling bias. The process model used for the design of the inventory control is utilized in the tuning...... as an approximation to reduce time required on experiments. The method is illustrated in an application with a multivariable inventory control implementation on a four tank system....

Adaptive Sensor Tuning for Seismic Event Detection in Environment with Electromagnetic Noise

Science.gov (United States)

Ziegler, Abra E.

The goal of this research is to detect possible microseismic events at a carbon sequestration site. Data recorded on a continuous downhole microseismic array in the Farnsworth Field, an oil field in Northern Texas that hosts an ongoing carbon capture, utilization, and storage project, were evaluated using machine learning and reinforcement learning techniques to determine their effectiveness at seismic event detection on a dataset with electromagnetic noise. The data were recorded from a passive vertical monitoring array consisting of 16 levels of 3-component 15 Hz geophones installed in the field and continuously recording since January 2014. Electromagnetic and other noise recorded on the array has significantly impacted the utility of the data and it was necessary to characterize and filter the noise in order to attempt event detection. Traditional detection methods using short-term average/long-term average (STA/LTA) algorithms were evaluated and determined to be ineffective because of changing noise levels. To improve the performance of event detection and automatically and dynamically detect seismic events using effective data processing parameters, an adaptive sensor tuning (AST) algorithm developed by Sandia National Laboratories was utilized. AST exploits neuro-dynamic programming (reinforcement learning) trained with historic event data to automatically self-tune and determine optimal detection parameter settings. The key metric that guides the AST algorithm is consistency of each sensor with its nearest neighbors: parameters are automatically adjusted on a per station basis to be more or less sensitive to produce consistent agreement of detections in its neighborhood. The effects that changes in neighborhood configuration have on signal detection were explored, as it was determined that neighborhood-based detections significantly reduce the number of both missed and false detections in ground-truthed data. The performance of the AST algorithm was

Coexisting synchronous and asynchronous states in locally coupled array of oscillators by partial self-feedback control

Science.gov (United States)

Bera, Bidesh K.; Ghosh, Dibakar; Parmananda, Punit; Osipov, G. V.; Dana, Syamal K.

2017-07-01

We report the emergence of coexisting synchronous and asynchronous subpopulations of oscillators in one dimensional arrays of identical oscillators by applying a self-feedback control. When a self-feedback is applied to a subpopulation of the array, similar to chimera states, it splits into two/more sub-subpopulations coexisting in coherent and incoherent states for a range of self-feedback strength. By tuning the coupling between the nearest neighbors and the amount of self-feedback in the perturbed subpopulation, the size of the coherent and the incoherent sub-subpopulations in the array can be controlled, although the exact size of them is unpredictable. We present numerical evidence using the Landau-Stuart system and the Kuramoto-Sakaguchi phase model.

Transverse betatron tune measurements

International Nuclear Information System (INIS)

Serio, M.

1989-01-01

In this paper the concept of the betatron tune and the techniques to measure it are discussed. The smooth approximation is introduced along with the terminology of betatron oscillations, phase advance and tune. Single particle and beam spectra in the presence of synchro-betatron oscillations are treated with emphasis on the consequences of sampling the beam position. After a general presentation of various kinds of beam position monitors and transverse kickers, the time domain and frequency domain analysis of the beam response to a transverse excitation are discussed and several methods and applications of the tune measurements are listed

Broadband perfect infrared absorption by tuning epsilon-near-zero and epsilon-near-pole resonances of multilayer ITO nanowires.

Science.gov (United States)

Zhou, Kun; Cheng, Qiang; Song, Jinlin; Lu, Lu; Jia, Zhihao; Li, Junwei

2018-01-01

We numerically investigate the broadband perfect infrared absorption by tuning epsilon-near-zero (ENZ) and epsilon-near-pole (ENP) resonances of multilayer indium tin oxide nanowires (ITO NWs). The monolayer ITO NWs array shows intensive absorption at ENZ and ENP wavelengths for p polarization, while only at the ENP wavelength for s polarization. Moreover, the ENP resonances are almost omnidirectional and the ENZ resonances are angularly dependent. Therefore, the absorption bandwidth is broader for p polarization than that for s polarization when polarized waves are incident obliquely. The ENZ resonances can be tuned by altering the doping concentration and volume filling factor of ITO NWs. However, the ENP resonances only can be tuned by changing the doping concentration of ITO NWs, and volume filling factor impacts little on the ENP resonances. Based on the strong absorption properties of each layer at their own ENP and ENZ resonances, the tuned absorption of the bilayer ITO NWs with the different doping concentrations can be broader and stronger. Furthermore, multilayer ITO NWs can achieve broadband perfect absorption by controlling the doping concentration, volume filling factor, and length of the NWs in each layer. This study has the potential to apply to applications requiring efficient absorption and energy conversion.

Ultra-high-aspect-orthogonal and tunable three dimensional polymeric nanochannel stack array for BioMEMS applications

Science.gov (United States)

Heo, Joonseong; Kwon, Hyukjin J.; Jeon, Hyungkook; Kim, Bumjoo; Kim, Sung Jae; Lim, Geunbae

2014-07-01

Nanofabrication technologies have been a strong advocator for new scientific fundamentals that have never been described by traditional theory, and have played a seed role in ground-breaking nano-engineering applications. In this study, we fabricated ultra-high-aspect (~106 with O(100) nm nanochannel opening and O(100) mm length) orthogonal nanochannel array using only polymeric materials. Vertically aligned nanochannel arrays in parallel can be stacked to form a dense nano-structure. Due to the flexibility and stretchability of the material, one can tune the size and shape of the nanochannel using elongation and even roll the stack array to form a radial-uniformly distributed nanochannel array. The roll can be cut at discretionary lengths for incorporation with a micro/nanofluidic device. As examples, we demonstrated ion concentration polarization with the device for Ohmic-limiting/overlimiting current-voltage characteristics and preconcentrated charged species. The density of the nanochannel array was lower than conventional nanoporous membranes, such as anodic aluminum oxide membranes (AAO). However, accurate controllability over the nanochannel array dimensions enabled multiplexed one microstructure-on-one nanostructure interfacing for valuable biological/biomedical microelectromechanical system (BioMEMS) platforms, such as nano-electroporation.Nanofabrication technologies have been a strong advocator for new scientific fundamentals that have never been described by traditional theory, and have played a seed role in ground-breaking nano-engineering applications. In this study, we fabricated ultra-high-aspect (~106 with O(100) nm nanochannel opening and O(100) mm length) orthogonal nanochannel array using only polymeric materials. Vertically aligned nanochannel arrays in parallel can be stacked to form a dense nano-structure. Due to the flexibility and stretchability of the material, one can tune the size and shape of the nanochannel using elongation and even

The ATLAS Monte Carlo tuning system

CERN Document Server

Wahrmund, S; The ATLAS collaboration

2011-01-01

The ATLAS experiment moved the tuning of the underlying event and minimum bias event shape modeling, previously done in a manual fashion, to the automated Professor tuning tool, employed in connection with the Rivet analysis framework, when the first corresponding experimental analysis from LHC became available. The tuning effort for the Pythia 8 generator, which includes improved models for diffraction, has been started in this automated way in ATLAS, with the aim of getting a good description of the pile-up generated by multiple minimum bias interactions. The first results for these Pythia 8 tunes are presented, including a study of tunes for various PDFs.

Oracle SQL tuning with Oracle SQLTXPLAIN

CERN Document Server

Charalambides, Stelios

2013-01-01

Oracle SQL Tuning with SQLTXPLAIN is a practical guide to SQL tuning the way Oracle's own experts do it, using a freely downloadable tool called SQLTXPLAIN. Using this simple tool you'll learn how to tune even the most complex SQL, and you'll learn to do it quickly, without the huge learning curve usually associated with tuning as a whole.  Firmly based in real world problems, this book helps you reclaim system resources and avoid the most common bottleneck in overall performance, badly tuned SQL.  You'll learn how the optimizer works, how to take advantage of its latest features, and when it'

Tuning magnet power supply

International Nuclear Information System (INIS)

Han, B.M.; Karady, G.G.; Thiessen, H.A.

1989-01-01

The particles in a Rapid Cycling Accelerator are accelerated by rf cavities, which are tuned by dc biased ferrite cores. The tuning is achieved by the regulation of bias current, which is produced by a power supply. The tuning magnet power supply utilizes a bridge circuit, supplied by a three phase rectifier. During the rise of the current, when the particles are accelerated, the current is controlled with precision by the bridge which operates a power amplifier. During the fall of the current, the bridge operates in a switching mode and recovers the energy stored in the ferrites. The recovered energy is stored in a capacitor bank. The bridge circuit is built with 150 power transistors. The drive, protection and control circuit were designed and built from commercial component. The system will be used for a rf cavity experiment in Los Alamos and will serve as a prototype tuning power supply for future accelerators. 1 ref., 7 figs

Tuning antimicrobial properties of biomimetic nanopatterned surfaces.

Science.gov (United States)

Michalska, Martyna; Gambacorta, Francesca; Divan, Ralu; Aranson, Igor S; Sokolov, Andrey; Noirot, Philippe; Laible, Philip D

2018-04-05

Nature has amassed an impressive array of structures that afford protection from microbial colonization/infection when displayed on the exterior surfaces of organisms. Here, controlled variation of the features of mimetics derived from etched silicon allows for tuning of their antimicrobial efficacy. Materials with nanopillars up to 7 μm in length are extremely effective against a wide range of microbial species and exceed the performance of natural surfaces; in contrast, materials with shorter/blunter nanopillars (<2 μm) selectively killed specific species. Using a combination of microscopies, the mechanisms by which bacteria are killed are demonstrated, emphasizing the dependence upon pillar density and tip geometry. Additionally, real-time imaging reveals how cells are immobilized and killed rapidly. Generic or selective protection from microbial colonization could be conferred to surfaces [for, e.g., internal medicine, implants (joint, dental, and cosmetic), food preparation, and the agricultural industry] patterned with these materials as coatings.

ATLAS Run 1 Pythia8 tunes

CERN Document Server

The ATLAS collaboration

2014-01-01

We present tunes of the Pythia8 Monte~Carlo event generator's parton shower and multiple parton interaction parameters to a range of data observables from ATLAS Run 1. Four new tunes have been constructed, corresponding to the four leading-order parton density functions, CTEQ6L1, MSTW2008LO, NNPDF23LO, and HERAPDF15LO, each simultaneously tuning ten generator parameters. A set of systematic variations is provided for the NNPDF tune, based on the eigentune method. These tunes improve the modeling of observables that can be described by leading-order + parton shower simulation, and are primarily intended for use in situations where next-to-leading-order and/or multileg parton-showered simulations are unavailable or impractical.

Confined surface plasmon sensors based on strongly coupled disk-in-volcano arrays.

Science.gov (United States)

Ai, Bin; Wang, Limin; Möhwald, Helmuth; Yu, Ye; Zhang, Gang

2015-02-14

Disk-in-volcano arrays are reported to greatly enhance the sensing performance due to strong coupling in the nanogaps between the nanovolcanos and nanodisks. The designed structure, which is composed of a nanovolcano array film and a disk in each cavity, is fabricated by a simple and efficient colloidal lithography method. By tuning structural parameters, the disk-in-volcano arrays show greatly enhanced resonances in the nanogaps formed by the disks and the inner wall of the volcanos. Therefore they respond to the surrounding environment with a sensitivity as high as 977 nm per RIU and with excellent linear dependence on the refraction index. Moreover, through mastering the fabrication process, biological sensing can be easily confined to the cavities of the nanovolcanos. The local responsivity has the advantages of maximum surface plasmon energy density in the nanogaps, reducing the sensing background and saving expensive reagents. The disk-in-volcano arrays also possess great potential in applications of optical and electrical trapping and single-molecule analysis, because they enable establishment of electric fields across the gaps.

The fabrication techniques of Z-pinch targets. Techniques of fabricating self-adapted Z-pinch wire-arrays

International Nuclear Information System (INIS)

Qiu Longhui; Wei Yun; Liu Debin; Sun Zuoke; Yuan Yuping

2002-01-01

In order to fabricate wire arrays for use in the Z-pinch physical experiments, the fabrication techniques are investigated as follow: Thickness of about 1-1.5 μm of gold is electroplated on the surface of ultra-fine tungsten wires. Fibers of deuterated-polystyrene (DPS) with diameters from 30 to 100 microns are made from molten DPS. And two kinds of planar wire-arrays and four types of annular wire-arrays are designed, which are able to adapt to the variation of the distance between the cathode and anode inside the target chamber. Furthermore, wire-arrays with diameters form 5-24 μm are fabricated with tungsten wires, respectively. The on-site test shows that the wire-arrays can self-adapt to the distance changes perfectly

Integrated ZnO nanotube arrays as efficient dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Xi, Y., E-mail: yxi6@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Wu, W.Z.; Fang, H. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Hu, C.G. [Department of Applied Physics, Chongqing University, Chongqing 400044 (China)

2012-07-15

Highlights: Black-Right-Pointing-Pointer Tuning the reaction parameters, we got the best reaction conditions on ITO glass. Black-Right-Pointing-Pointer Introduce ZnO NTs design of photoanode featuring high aspect ratio structure. Black-Right-Pointing-Pointer The design strategy integrates the optical fibers or ITO with ZnO NTs grown. - Abstract: Zinc oxide (ZnO) is a wide band gap semiconducting material and has been considered as an alternative material in dye-sensitized solar cell (DSSC) applications. A high-performance nanotube (NT) photoanode must have a large surface area for dye adsorption in order to enhance conversion efficiency. In this work, the way of hydrothermally grown ZnO NT arrays on the indium tin oxide (ITO) substrate is presented by utilizing a systematic study. By adjusting the hydrothermal reaction parameters, we attained the optimizing reaction conditions on the ITO substrate. Moreover, ZnO NT arrays are introduced as a photoanode on various substrates, such as optical fiber and ITO glass, for DSSCs applications. We took the contrast test with conversion efficiency of the DSSC based on ZnO NT arrays versus ZnO nanowire arrays on the ITO substrate, which the DSSC based on ZnO NT arrays shows significantly enhanced power conversion efficiency. Furthermore, the conversion efficiency of DSSC based on the ZnO NT arrays grown on an optical fiber substrate is enhanced up to 1.44%.

Robust Self Tuning Controllers

DEFF Research Database (Denmark)

Poulsen, Niels Kjølstad

1985-01-01

The present thesis concerns robustness properties of adaptive controllers. It is addressed to methods for robustifying self tuning controllers with respect to abrupt changes in the plant parameters. In the thesis an algorithm for estimating abruptly changing parameters is presented. The estimator...... has several operation modes and a detector for controlling the mode. A special self tuning controller has been developed to regulate plant with changing time delay.......The present thesis concerns robustness properties of adaptive controllers. It is addressed to methods for robustifying self tuning controllers with respect to abrupt changes in the plant parameters. In the thesis an algorithm for estimating abruptly changing parameters is presented. The estimator...

Pre-tuning of TRISTAN superconducting RF cavities

International Nuclear Information System (INIS)

Tajima, Tsuyoshi; Furuya, Takaaki; Suzuki, Toshiji; Iino, Yohsuke.

1990-01-01

Pre-tuning of thirty-two TRISTAN superconducting cavities has been done. In this paper are described the pre-tuning system and the results of all the cavities. The average field flatness was 1.4 % after pre-tuning. From our experience, the followings are important, 1) to evacuate the cavity during the process of the pre-tuning to avoid the uncertainty in evacuation, 2) pre-tuning is needed after annealing because it causes changes of the cell length and the field profile and 3) field flatness sometimes changes when expanded and 4) cells should not be expanded more than 1.5 mm after pre-tuning since inelastic deformation occurs. (author)

Functional Characterization of MODY2 Mutations Highlights the Importance of the Fine-Tuning of Glucokinase and Its Role in Glucose Sensing

Science.gov (United States)

García-Herrero, Carmen-María; Rubio-Cabezas, Oscar; Azriel, Sharona; Gutierrez-Nogués, Angel; Aragonés, Angel; Vincent, Olivier; Campos-Barros, Angel; Argente, Jesús; Navas, María-Angeles

2012-01-01

Glucokinase (GK) acts as a glucose sensor in the pancreatic beta-cell and regulates insulin secretion. Heterozygous mutations in the human GK-encoding GCK gene that reduce the activity index increase the glucose-stimulated insulin secretion threshold and cause familial, mild fasting hyperglycaemia, also known as Maturity Onset Diabetes of the Young type 2 (MODY2). Here we describe the biochemical characterization of five missense GK mutations: p.Ile130Thr, p.Asp205His, p.Gly223Ser, p.His416Arg and p.Ala449Thr. The enzymatic analysis of the corresponding bacterially expressed GST-GK mutant proteins show that all of them impair the kinetic characteristics of the enzyme. In keeping with their position within the protein, mutations p.Ile130Thr, p.Asp205His, p.Gly223Ser, and p.His416Arg strongly decrease the activity index of GK, affecting to one or more kinetic parameters. In contrast, the p.Ala449Thr mutation, which is located in the allosteric activator site, does not affect significantly the activity index of GK, but dramatically modifies the main kinetic parameters responsible for the function of this enzyme as a glucose sensor. The reduced Kcat of the mutant (3.21±0.28 s−1 vs 47.86±2.78 s−1) is balanced by an increased glucose affinity (S0.5 = 1.33±0.08 mM vs 7.86±0.09 mM) and loss of cooperativity for this substrate. We further studied the mechanism by which this mutation impaired GK kinetics by measuring the differential effects of several competitive inhibitors and one allosteric activator on the mutant protein. Our results suggest that this mutation alters the equilibrium between the conformational states of glucokinase and highlights the importance of the fine-tuning of GK and its role in glucose sensing. PMID:22291974

How safe is tuning a radio?: using the radio tuning task as a benchmark for distracted driving.

Science.gov (United States)

Lee, Ja Young; Lee, John D; Bärgman, Jonas; Lee, Joonbum; Reimer, Bryan

2018-01-01

Drivers engage in non-driving tasks while driving, such as interactions entertainment systems. Studies have identified glance patterns related to such interactions, and manual radio tuning has been used as a reference task to set an upper bound on the acceptable demand of interactions. Consequently, some view the risk associated with radio tuning as defining the upper limit of glance measures associated with visual-manual in-vehicle activities. However, we have little knowledge about the actual degree of crash risk that radio tuning poses and, by extension, the risk of tasks that have similar glance patterns as the radio tuning task. In the current study, we use counterfactual simulation to take the glance patterns for manual radio tuning tasks from an on-road experiment and apply these patterns to lead-vehicle events observed in naturalistic driving studies. We then quantify how often the glance patterns from radio tuning are associated with rear-end crashes, compared to driving only situations. We used the pre-crash kinematics from 34 crash events from the SHRP2 naturalistic driving study to investigate the effect of radio tuning in crash-imminent situations, and we also investigated the effect of radio tuning on 2,475 routine braking events from the Safety Pilot project. The counterfactual simulation showed that off-road glances transform some near-crashes that could have been avoided into crashes, and glance patterns observed in on-road radio tuning experiment produced 2.85-5.00 times more crashes than baseline driving. Copyright © 2017 Elsevier Ltd. All rights reserved.

Manipulation of extinction spectra of P3HT/PMMA medium arrays on silicon substrate containing self-assembled gold nanoparticles

International Nuclear Information System (INIS)

Wu, Ming-Chung; Chen, Shih-Wen; Li, Jia-Han; Chou, Yi; Lin, Jhih-Fong; Chen, Yang-Fang; Su, Wei-Fang

2012-01-01

In this study, we report a simple novel approach to modulate the extinction spectra of P3HT/PMMA by manipulating the medium arrays on a substrate that is coated with self-assembled gold nanoparticles. The 20 nm gold nanoparticles were synthesized and then self-assembled on the APTMS/silicon substrate surface by immersing the substrate into the gold colloid suspension. A high-resolution P3HT/PMMA photoluminescent electron beam resist was used to fabricate various square hole arrays on the substrate containing gold nanoparticles. The P3HT/PMMA medium composition causes the blue shifts in the extinction peaks of up to 40.6 nm by decreasing the period from 500 nm to 200 nm for P3HT/PMMA square hole arrays with a diameter of 100 nm. The magnitude of blue shift is directly proportional to the product of the changes of medium refractive index and the array structure factor. These peak shifts and intensity of extinction spectra for various P3HT/PMMA medium arrays are well described by the finite-difference time-domain (FDTD) simulation results. Since this simple cost-effective technique can tune the extinction spectrum of medium and adding the gold nanoparticles can give more functionalities for sensing applications, such as surface-enhanced Raman scattering (SERS), that provides good opportunities for the design and fabrication of new optoelectronic devices and sensors. Highlights: ► We can tune the extinction spectra of P3HT/PMMA by manipulating the medium arrays. ► These optical behaviors of P3HT/PMMA medium arrays are well described by FDTD simulation results. ► Adding the Au nanoparticles can give more functionalities for sensing applications.

Manipulation of extinction spectra of P3HT/PMMA medium arrays on silicon substrate containing self-assembled gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Wu, Ming-Chung [Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 333-02, Taiwan (China); Chen, Shih-Wen; Li, Jia-Han [Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei 106-17, Taiwan (China); Chou, Yi; Lin, Jhih-Fong [Department of Materials Science and Engineering, National Taiwan University, Taipei 106-17, Taiwan (China); Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei 106-17, Taiwan (China); Su, Wei-Fang, E-mail: suwf@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, Taipei 106-17, Taiwan (China)

2012-11-15

In this study, we report a simple novel approach to modulate the extinction spectra of P3HT/PMMA by manipulating the medium arrays on a substrate that is coated with self-assembled gold nanoparticles. The 20 nm gold nanoparticles were synthesized and then self-assembled on the APTMS/silicon substrate surface by immersing the substrate into the gold colloid suspension. A high-resolution P3HT/PMMA photoluminescent electron beam resist was used to fabricate various square hole arrays on the substrate containing gold nanoparticles. The P3HT/PMMA medium composition causes the blue shifts in the extinction peaks of up to 40.6 nm by decreasing the period from 500 nm to 200 nm for P3HT/PMMA square hole arrays with a diameter of 100 nm. The magnitude of blue shift is directly proportional to the product of the changes of medium refractive index and the array structure factor. These peak shifts and intensity of extinction spectra for various P3HT/PMMA medium arrays are well described by the finite-difference time-domain (FDTD) simulation results. Since this simple cost-effective technique can tune the extinction spectrum of medium and adding the gold nanoparticles can give more functionalities for sensing applications, such as surface-enhanced Raman scattering (SERS), that provides good opportunities for the design and fabrication of new optoelectronic devices and sensors. Highlights: Black-Right-Pointing-Pointer We can tune the extinction spectra of P3HT/PMMA by manipulating the medium arrays. Black-Right-Pointing-Pointer These optical behaviors of P3HT/PMMA medium arrays are well described by FDTD simulation results. Black-Right-Pointing-Pointer Adding the Au nanoparticles can give more functionalities for sensing applications.

Mechanical Robustness of FPA in a-Si Microbolometer with Fine Pitch

Directory of Open Access Journals (Sweden)

Hee Yeoun Kim

2011-04-01

Full Text Available Microbolometer array sensors with fine pitch pixel arrays have been implemented using amorphous silicon supported by two contact pads. Simple beam test structures were fabricated and characterized for the purpose of designing a focal plane with geometrical flatness. As the beam length decreased, the effect of beam width on the bending was minimized. Membrane deformation of focal plane in a real pixel showed downward curvature by residual stress of a-Si and Ti layer. The tilting deformation was caused by the misalign effect of contact pad and confirmed by FEA (Finite Element Analysis simulation results. The electro-optical properties of bolometer have been measured to be noise equivalent temperature difference (NETD = 145 mK, temperature Coefficient of Resistance (TCR = −2 %/K, and thermal time constant = 1.99 ms.

Development of an On-Line Self-Tuning FPGA-PID-PWM Control Algorithm Design for DC-DC Buck Converter in Mobile Applications

Directory of Open Access Journals (Sweden)

Ahmed Sabah Al-Araji

2017-08-01

Full Text Available This paper presents a new development of an on-line hybrid self-tuning control algorithm of the Field Programmable Gate Array - Proportional Integral Derivative - Pulse Width Modulation (FPGA-PID-PWM controller for DC-DC buck converter which is used in battery operation of mobile applications. The main goal in this work is to propose structure of the hybrid Bees-PSO tuning control algorithm which has a capability of quickly and precisely searching in the global regions in order to obtain optimal gain parameters for the proposed controller to generate the best voltage control action to achieve the desired performance of the Buck converter output. Matlab simulation results and Xilinx development tool Integrated Software Environment (ISE experimental work show the robustness and effectiveness of the proposed on-line hybrid Bees-PSO tuning control algorithm in terms of obtaining smooth and unsaturated state voltage control action and minimizing the tracking voltage error of the Buck converter output. Moreover, the fitness evaluation number is reduced.

Development of impedance matching technologies for ICRF antenna arrays

International Nuclear Information System (INIS)

Pinsker, R.I.

1998-01-01

All high-power ion cyclotron range of frequency (ICRF) heating systems include devices for matching the input impedance of the antenna array to the generator output impedance. For most types of antennas used, the input impedance is strongly time dependent on timescales as rapid as 10 -1 s, while the radio frequency (RF) generators used are capable of producing full power only into a stationary load impedance. Hence, the dynamic response of the matching method is of great practical importance. In this paper, world-wide developments in this field over the past decade are reviewed. These techniques may be divided into several classes. The edge plasma parameters that determine the antenna array's input impedance may be controlled to maintain a fixed load impedance. The frequency of the RF source can be feedback controlled to compensate for changes in the edge plasma conditions, or fast variable tuning elements in the transmission line between the generator output and the antenna input connections can provide the necessary time-varying impedance transformation. In 'lossy passive schemes', reflected power due to the time-varying impedance of the antenna array is diverted to a dummy load. Each of these techniques can be applied to a pre-existing antenna system. If a new antenna is to be designed, recent advances allow the antenna array to have the intrinsic property of presenting a constant load to the feeding transmission lines despite the varying load seen by each antenna in the array. (author)

Development of impedance matching technologies for ICRF antenna arrays

International Nuclear Information System (INIS)

Pinsker, R.I.

1998-03-01

All high power ICRF heating systems include devices for matching the input impedance of the antenna array to the generator output impedance. For most types of antennas used, the input impedance is strongly time-dependent on timescales as rapid as 10-4 s, while the rf generators used are capable of producing full power only into a stationary load impedance. Hence, the dynamic response of the matching method is of great practical importance. In this paper, world-wide developments in this field over the past decade are reviewed. These techniques may be divided into several classes. The edge plasma parameters that determine the antenna array's input impedance may be controlled to maintain a fixed load impedance. The frequency of the rf source can be feedback controlled to compensate for changes in the edge plasma conditions, or fast variable tuning elements in the transmission line between the generator output and the antenna input connections can provide the necessary time-varying impedance transformation. In lossy passive schemes, reflected power due to the time-varying impedance of the antenna array is diverted to a dummy load. Each of these techniques can be applied to a pre-existing antenna system. If a new antenna is to be designed, recent advances allow the antenna array to have the intrinsic property of presenting a constant load to the feeding transmission lines despite the varying load seen by each antenna in the array

Betatron tune measurement

International Nuclear Information System (INIS)

Dinev, D.

2001-01-01

On the basis of the comparative review of the methods for the betatron tune measurement in cyclic accelerators of synchrotrons type, the research of these methods is carried out from the point of view of their applicability to Nuclotron. Both methods using measurement of the statistical fluctuations of the beam current (Schottky noise) and methods using coherent beam excitation have been discussed. The emphasis is on the final results of importance for the tune measurement practice. Signal processing is briefly discussed too

Upgrades to PEP-II Tune Measurements

Energy Technology Data Exchange (ETDEWEB)

Fisher, Alan S.

2002-07-30

The tune monitors for the two-ring PEP-II collider convert signals from one set of four BPM-type pickup buttons per ring into horizontal and vertical differences, which are then downconverted from 952 MHz (twice the RF) to baseband. Two-channel 10-MHz FFT spectrum analyzers show spectra in X-window displays in the Control Room, to assist PEP operators. When operating with the original system near the beam-beam limit, collisions broadened and flattened the tune peaks, often bringing them near the noise floor. We recently installed new downconverters that increase the signal-to-noise ratio by about 5 dB. In addition, we went from one to two sets of pickups per ring, near focusing and defocusing quadrupoles, so that signals for both planes originate at locations with large amplitudes. We also have just installed a tune tracker, based on a digital lock-in amplifier (one per tune plane) that is controlled by an EPICS software feedback loop. The tracker monitors the phase of the beam's response to a sinusoidal excitation, and adjusts the drive frequency to track the middle of the 1 go-degree phase transition across the tune resonance. We plan next to test an outer loop controlling the tune quadrupoles based on this tune measurement.

Upgrades to PEP-II Tune Measurements

Energy Technology Data Exchange (ETDEWEB)

Fisher, Alan S.

2002-07-30

The tune monitors for the two-ring PEP-II collider convert signals from one set of four BPM-type pickup buttons per ring into horizontal and vertical differences, which are then downconverted from 952 MHz (twice the RF) to baseband. Two-channel l0-MHz FFT spectrum analyzers show spectra in X-window displays in the Control Room, to assist PEP operators. When operating with the original system near the beam-beam limit, collisions broadened and flattened the tune peaks, often bringing them near the noise floor. We recently installed new downconverters that increase the signal-to-noise ratio by about 5 dB. In addition, we went from one to two sets of pickups per ring, near focusing and defocusing quadrupoles, so that signals for both planes originate at locations with large amplitudes. We also have just installed a tune tracker, based on a digital lock-in amplifier (one per tune plane) that is controlled by an EPICS software feedback loop. The tracker monitors the phase of the beam's response to a sinusoidal excitation, and adjusts the drive frequency to track the middle of the 180-degree phase transition across the tune resonance. We plan next to test an outer loop controlling the tune quadrupoles based on this tune measurement.

Upgrades to PEP-II tune measurements

International Nuclear Information System (INIS)

Fisher, Alan S.; Petree, Mark; Wienands, Uli; Allison, Stephanie; Laznovsky, Michael; Seeman, Michael; Robin, Jolene

2002-01-01

The tune monitors for the two-ring PEP-II collider convert signals from one set of four BPM-type pickup buttons per ring into horizontal and vertical differences, which are then downconverted from 952 MHz (twice the RF) to baseband. Two-channel 10-MHz FFT spectrum analyzers show spectra in X-window displays in the Control Room, to assist PEP operators. When operating with the original system near the beam-beam limit, collisions broadened and flattened the tune peaks, often bringing them near the noise floor. We recently installed new downconverters that increase the signal-to-noise ratio by about 5 dB. In addition, we went from one to two sets of pickups per ring, near focusing and defocusing quadrupoles, so that signals for both planes originate at locations with large amplitudes. We also have just installed a tune tracker, based on a digital lock-in amplifier (one per tune plane) that is controlled by an EPICS software feedback loop. The tracker monitors the phase of the beam's response to a sinusoidal excitation, and adjusts the drive frequency to track the middle of the 180-degree phase transition across the tune resonance. We plan next to test an outer loop controlling the tune quadrupoles based on this tune measurement

Enlargement of Tuning Range in a Ferrite-Tuned Cavity Through Superposed Orthogonal and Parallel Magnetic Bias

CERN Document Server

Vollinger, C

2013-01-01

Conventional ferrite-tuned cavities operate either with bias fields that are orthogonal or parallel to the magnetic RF-field. For a cavity that tunes rapidly over an overall frequency range around 100-400 MHz with high Q, we use ferrite garnets exposed to an innovative new biasing method consisting of a superposition of perpendicular and parallel magnetic fields. This method leads to a significant enlargement of the high-Q cavity tuning range by defining an operation point close to the magnetic saturation and thus improving ferrite material behaviour. A further advantage of this technique is the fast tuning speed resulting from the fact that tuning is carried out either with pure parallel biasing, or together with a very small change of operating point from perpendicular bias. In this paper, several scaled test models of ferrite-filled resonators are shown; measurements on the set-ups are compared and discussed.

Automatic tuning of free electron lasers

Energy Technology Data Exchange (ETDEWEB)

Agapov, Ilya; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL, Schenefeld (Germany); Tomin, Sergey [European XFEL, Schenefeld (Germany); NRC Kurchatov Institute, Moscow (Russian Federation)

2017-04-07

Existing FEL facilities often suffer from stability issues: so electron orbit, transverse electron optics, electron bunch compression and other parameters have to be readjusted often to account for drifts in performance of various components. The tuning procedures typically employed in operation are often manual and lengthy. We have been developing a combination of model-free and model-based automatic tuning methods to meet the needs of present and upcoming XFEL facilities. Our approach has been implemented at FLASH to achieve automatic SASE tuning using empirical control of orbit, electron optics and bunch compression. In this paper we describe our approach to empirical tuning, the software which implements it, and the results of using it at FLASH.We also discuss the potential of using machine learning and model-based techniques in tuning methods.

Automatic tuning of free electron lasers

International Nuclear Information System (INIS)

Agapov, Ilya; Zagorodnov, Igor; Geloni, Gianluca; Tomin, Sergey

2017-01-01

Existing FEL facilities often suffer from stability issues: so electron orbit, transverse electron optics, electron bunch compression and other parameters have to be readjusted often to account for drifts in performance of various components. The tuning procedures typically employed in operation are often manual and lengthy. We have been developing a combination of model-free and model-based automatic tuning methods to meet the needs of present and upcoming XFEL facilities. Our approach has been implemented at FLASH to achieve automatic SASE tuning using empirical control of orbit, electron optics and bunch compression. In this paper we describe our approach to empirical tuning, the software which implements it, and the results of using it at FLASH.We also discuss the potential of using machine learning and model-based techniques in tuning methods.

Thermal conductivity of vertically aligned carbon nanotube arrays: Growth conditions and tube inhomogeneity

Energy Technology Data Exchange (ETDEWEB)

Bauer, Matthew L.; Pham, Quang N.; Saltonstall, Christopher B.; Norris, Pamela M. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904-4746 (United States)

2014-10-13

The thermal conductivity of vertically aligned carbon nanotube arrays (VACNTAs) grown on silicon dioxide substrates via chemical vapor deposition is measured using a 3ω technique. For each sample, the VACNTA layer and substrate are pressed to a heating line at varying pressures to extract the sample's thermophysical properties. The nanotubes' structure is observed via transmission electron microscopy and Raman spectroscopy. The presence of hydrogen and water vapor in the fabrication process is tuned to observe the effect on measured thermal properties. The presence of iron catalyst particles within the individual nanotubes prevents the array from achieving the overall thermal conductivity anticipated based on reported measurements of individual nanotubes and the packing density.

Fine-grained visual marine vessel classification for coastal surveillance and defense applications

Science.gov (United States)

Solmaz, Berkan; Gundogdu, Erhan; Karaman, Kaan; Yücesoy, Veysel; Koç, Aykut

2017-10-01

The need for capabilities of automated visual content analysis has substantially increased due to presence of large number of images captured by surveillance cameras. With a focus on development of practical methods for extracting effective visual data representations, deep neural network based representations have received great attention due to their success in visual categorization of generic images. For fine-grained image categorization, a closely related yet a more challenging research problem compared to generic image categorization due to high visual similarities within subgroups, diverse applications were developed such as classifying images of vehicles, birds, food and plants. Here, we propose the use of deep neural network based representations for categorizing and identifying marine vessels for defense and security applications. First, we gather a large number of marine vessel images via online sources grouping them into four coarse categories; naval, civil, commercial and service vessels. Next, we subgroup naval vessels into fine categories such as corvettes, frigates and submarines. For distinguishing images, we extract state-of-the-art deep visual representations and train support-vector-machines. Furthermore, we fine tune deep representations for marine vessel images. Experiments address two scenarios, classification and verification of naval marine vessels. Classification experiment aims coarse categorization, as well as learning models of fine categories. Verification experiment embroils identification of specific naval vessels by revealing if a pair of images belongs to identical marine vessels by the help of learnt deep representations. Obtaining promising performance, we believe these presented capabilities would be essential components of future coastal and on-board surveillance systems.

Building the Support for Radar Processing across Memory Hierarchies: On the Development of an Array Class with Shapes using Expression Templates in C++̂

National Research Council Canada - National Science Library

Mullin, Lenore

2004-01-01

...), could be used to develop software for radar and other DSP applications. This software needs to be tuned to use the levels of memory hierarchies efficiently without the materialization of array valued temporaries 3...

Fully parallel write/read in resistive synaptic array for accelerating on-chip learning

Science.gov (United States)

Gao, Ligang; Wang, I.-Ting; Chen, Pai-Yu; Vrudhula, Sarma; Seo, Jae-sun; Cao, Yu; Hou, Tuo-Hung; Yu, Shimeng

2015-11-01

A neuro-inspired computing paradigm beyond the von Neumann architecture is emerging and it generally takes advantage of massive parallelism and is aimed at complex tasks that involve intelligence and learning. The cross-point array architecture with synaptic devices has been proposed for on-chip implementation of the weighted sum and weight update in the learning algorithms. In this work, forming-free, silicon-process-compatible Ta/TaO x /TiO2/Ti synaptic devices are fabricated, in which >200 levels of conductance states could be continuously tuned by identical programming pulses. In order to demonstrate the advantages of parallelism of the cross-point array architecture, a novel fully parallel write scheme is designed and experimentally demonstrated in a small-scale crossbar array to accelerate the weight update in the training process, at a speed that is independent of the array size. Compared to the conventional row-by-row write scheme, it achieves >30× speed-up and >30× improvement in energy efficiency as projected in a large-scale array. If realistic synaptic device characteristics such as device variations are taken into an array-level simulation, the proposed array architecture is able to achieve ∼95% recognition accuracy of MNIST handwritten digits, which is close to the accuracy achieved by software using the ideal sparse coding algorithm.

Fully parallel write/read in resistive synaptic array for accelerating on-chip learning

International Nuclear Information System (INIS)

Gao, Ligang; Chen, Pai-Yu; Seo, Jae-sun; Cao, Yu; Yu, Shimeng; Wang, I-Ting; Hou, Tuo-Hung; Vrudhula, Sarma

2015-01-01

A neuro-inspired computing paradigm beyond the von Neumann architecture is emerging and it generally takes advantage of massive parallelism and is aimed at complex tasks that involve intelligence and learning. The cross-point array architecture with synaptic devices has been proposed for on-chip implementation of the weighted sum and weight update in the learning algorithms. In this work, forming-free, silicon-process-compatible Ta/TaO_x/TiO_2/Ti synaptic devices are fabricated, in which >200 levels of conductance states could be continuously tuned by identical programming pulses. In order to demonstrate the advantages of parallelism of the cross-point array architecture, a novel fully parallel write scheme is designed and experimentally demonstrated in a small-scale crossbar array to accelerate the weight update in the training process, at a speed that is independent of the array size. Compared to the conventional row-by-row write scheme, it achieves >30× speed-up and >30× improvement in energy efficiency as projected in a large-scale array. If realistic synaptic device characteristics such as device variations are taken into an array-level simulation, the proposed array architecture is able to achieve ∼95% recognition accuracy of MNIST handwritten digits, which is close to the accuracy achieved by software using the ideal sparse coding algorithm. (paper)

Absolute transition probabilities in the NeI 3p-3s fine structure by beam-gas-dye laser spectroscopy

International Nuclear Information System (INIS)

Hartmetz, P.; Schmoranzer, H.

1983-01-01

The beam-gas-dye laser two-step excitation technique is further developed and applied to the direct measurement of absolute atomic transition probabilities in the NeI 3p-3s fine-structure transition array with a maximum experimental error of 5%. (orig.)

Superconducting Microwave Resonator Arrays for Submillimeter/Far-Infrared Imaging

Science.gov (United States)

Noroozian, Omid

Superconducting microwave resonators have the potential to revolutionize submillimeter and far-infrared astronomy, and with it our understanding of the universe. The field of low-temperature detector technology has reached a point where extremely sensitive devices like transition-edge sensors are now capable of detecting radiation limited by the background noise of the universe. However, the size of these detector arrays are limited to only a few thousand pixels. This is because of the cost and complexity of fabricating large-scale arrays of these detectors that can reach up to 10 lithographic levels on chip, and the complicated SQUID-based multiplexing circuitry and wiring for readout of each detector. In order to make substantial progress, next-generation ground-based telescopes such as CCAT or future space telescopes require focal planes with large-scale detector arrays of 104--10 6 pixels. Arrays using microwave kinetic inductance detectors (MKID) are a potential solution. These arrays can be easily made with a single layer of superconducting metal film deposited on a silicon substrate and pattered using conventional optical lithography. Furthermore, MKIDs are inherently multiplexable in the frequency domain, allowing ˜ 10 3 detectors to be read out using a single coaxial transmission line and cryogenic amplifier, drastically reducing cost and complexity. An MKID uses the change in the microwave surface impedance of a superconducting thin-film microresonator to detect photons. Absorption of photons in the superconductor breaks Cooper pairs into quasiparticles, changing the complex surface impedance, which results in a perturbation of resonator frequency and quality factor. For excitation and readout, the resonator is weakly coupled to a transmission line. The complex amplitude of a microwave probe signal tuned on-resonance and transmitted on the feedline past the resonator is perturbed as photons are absorbed in the superconductor. The perturbation can be

Tuning upconversion through energy migration in core-shell nanoparticles

KAUST Repository

Wang, Feng; Deng, Renren; Wang, Juan; Wang, Qingxiao; Han, Yu; Zhu, Haomiao; Chen, Xueyuan; Liu, Xiaogang

2011-01-01

Photon upconversion is promising for applications such as biological imaging, data storage or solar cells. Here, we have investigated upconversion processes in a broad range of gadolinium-based nanoparticles of varying composition. We show that by rational design of a core-shell structure with a set of lanthanide ions incorporated into separated layers at precisely defined concentrations, efficient upconversion emission can be realized through gadolinium sublattice-mediated energy migration for a wide range of lanthanide activators without long-lived intermediary energy states. Furthermore, the use of the core-shell structure allows the elimination of deleterious cross-relaxation. This effect enables fine-tuning of upconversion emission through trapping of the migrating energy by the activators. Indeed, the findings described here suggest a general approach to constructing a new class of luminescent materials with tunable upconversion emissions by controlled manipulation of energy transfer within a nanoscopic region. © 2011 Macmillan Publishers Limited. All rights reserved.

Tuning upconversion through energy migration in core-shell nanoparticles

KAUST Repository

Wang, Feng

2011-10-23

Photon upconversion is promising for applications such as biological imaging, data storage or solar cells. Here, we have investigated upconversion processes in a broad range of gadolinium-based nanoparticles of varying composition. We show that by rational design of a core-shell structure with a set of lanthanide ions incorporated into separated layers at precisely defined concentrations, efficient upconversion emission can be realized through gadolinium sublattice-mediated energy migration for a wide range of lanthanide activators without long-lived intermediary energy states. Furthermore, the use of the core-shell structure allows the elimination of deleterious cross-relaxation. This effect enables fine-tuning of upconversion emission through trapping of the migrating energy by the activators. Indeed, the findings described here suggest a general approach to constructing a new class of luminescent materials with tunable upconversion emissions by controlled manipulation of energy transfer within a nanoscopic region. © 2011 Macmillan Publishers Limited. All rights reserved.

Devil's staircase in a fully frustrated superconducting array

International Nuclear Information System (INIS)

Kim, S.; Choi, M.Y.

1993-01-01

A two-dimensional fully frustrated superconducting array with a combined direct and alternating applied current is studied both analytically and numerically. At zero temperature equations of motion can be reduced through the use of the translational symmetry present in the system. Remarkably, we find a series of subharmonic steps in addition to standard integer and half-integer giant Shapiro steps, leading to devil's staircase structure. We also present results of detailed numerical simulations, which indeed reveal such subharmonic fine structure. (orig.)

The fine art of ‘sourcery’

CERN Multimedia

2009-01-01

The commissioning of the new Linac4 source – first element of the new acceleration chain for the upgrade of the LHC (sLHC) – started at the beginning of July. After years of preparation but after only a few hours of fine-tuning of the numerous parameters involved, the source has delivered its first negative ions. The civil engineering work for the new Linac4 going on near Restaurant 2.While the LHC is preparing for restart, teams of experts involved in the sLHC project are also working on the new facilities that will allow the LHC to run at higher luminosity. The beginning of the new chain of accelerators is Linac4, whose excavation works started October last year. "The particle source that we are commissioning now will be installed at the beginning of the path", explains Maurizio Vretenar, Linac4 project leader. "It is a critical element of the chain as all protons that will circulate in the CERN accelerators will originate from it." The Linac 4 source is differ...

Gene expression analyses in tomato near isogenic lines provide evidence for ethylene and abscisic acid biosynthesis fine-tuning during arbuscular mycorrhiza development.

Science.gov (United States)

Fracetto, Giselle Gomes Monteiro; Peres, Lázaro Eustáquio Pereira; Lambais, Marcio Rodrigues

2017-07-01

colonization in tomato roots, indicating that, besides hormonal interactions, a fine-tuning of each hormone level is required for AM development.

Control of Fermilab Booster tunes

International Nuclear Information System (INIS)

Johnson, R.P; Meisner, K.; Sandberg, B.

1977-01-01

Control of the radial and vertical tunes of the booster is implemented using ramped correction quadrupoles. Minor modifications to the power supply cards for the 48 (previously) dc correction quadrupoles allow ''the tunes'' to be continuously programmed or held constant throughout the 33 ms acceleration cycle. This capability is in addition to the usual use of these quadrupoles to be independently varied to correct for harmonic distortions in the lattice. An automatic computer program measures and displays the tunes vs. time in the cycle to monitor performance and to allow the ramps to be adjusted by the machine operator

Mechanism of Fine-tuning pH Sensors in Proprotein Convertases: IDENTIFICATION OF A pH-SENSING HISTIDINE PAIR IN THE PROPEPTIDE OF PROPROTEIN CONVERTASE 1/3.

Science.gov (United States)

Williamson, Danielle M; Elferich, Johannes; Shinde, Ujwal

2015-09-18

The propeptides of proprotein convertases (PCs) regulate activation of cognate protease domains by sensing pH of their organellar compartments as they transit the secretory pathway. Earlier experimental work identified a conserved histidine-encoded pH sensor within the propeptide of the canonical PC, furin. To date, whether protonation of this conserved histidine is solely responsible for PC activation has remained unclear because of the observation that various PC paralogues are activated at different organellar pH values. To ascertain additional determinants of PC activation, we analyzed PC1/3, a paralogue of furin that is activated at a pH of ∼5.4. Using biophysical, biochemical, and cell-based methods, we mimicked the protonation status of various histidines within the propeptide of PC1/3 and examined how such alterations can modulate pH-dependent protease activation. Our results indicate that whereas the conserved histidine plays a crucial role in pH sensing and activation of this protease an additional histidine acts as a "gatekeeper" that fine-tunes the sensitivity of the PC1/3 propeptide to facilitate the release inhibition at higher proton concentrations when compared with furin. Coupled with earlier analyses that highlighted the enrichment of the amino acid histidine within propeptides of secreted eukaryotic proteases, our work elucidates how secreted proteases have evolved to exploit the pH of the secretory pathway by altering the spatial juxtaposition of titratable groups to regulate their activity in a spatiotemporal fashion. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Fine-Tuning ADAS Algorithm Parameters

Data.gov (United States)

U.S. Environmental Protection Agency — With the development of the Connected Vehicle technology that facilitates wirelessly communication among vehicles and road-side infrastructure, the Advanced Driver...

Baby universes, fine tuning problems

International Nuclear Information System (INIS)

Nielsen, H.B.; Ninomiya, Masao.

1988-12-01

We review the recently popular 'theory of baby universes' put forward by Banks, Coleman and Hawking. We then derive the strong CP breaking coefficient θ-bar to be very small, in a similar manner to the derivation of the cosmological constant being zero. A solution for an old controversy concerning the entropy creation in black holes is also discussed. We finally confront the baby universe theory with random dynamics. We conclude that the theory of baby universes is so successful that the essential features are likely true and might have to go into a right theory even if with some troubles at first. (author)

"Fine-tuning" durch interkulturelles Coaching

OpenAIRE

Steixner, Margret

2009-01-01

Margret Steixner plädiert in ihrem Beitrag für eine Integration des interkulturellen Coachings in andere Bereiche des Coachings. Basierend auf einer Coaching-Fallstudie entwickelt die Autorin einen hilfreichen Fragenkatalog für das interkulturelle Coaching. Intercultural Coaching identifies and develops intercultural competence as a key to success in the international and globalised work environment. Coaching in general has gained recognition as a very suitable method for competence develo...

Solar observations with the prototype of the Brazilian Decimetric Array

Science.gov (United States)

Sawant, H. S.; Ramesh, R.; Faria, C.; Cecatto, J. R.; Fernandes, F. C. R.; Madsen, F. H. R.; Subramanian, K. R.; Sundararajan, M. S.

The prototype of the Brazilian Decimetric Array BDA consists of 5 element alt-az mounted parabolic mesh type dishes of 4-meter diameter having base lines up to 220 meters in the E--W direction The array was put into regular operation at Cachoeira Paulista Brazil longitude 45 r 00 20 W and latitude 22 r 41 19 S This array operates in the frequency range of 1 2 -- 1 7 GHz Solar observations are carried at sim 1 4 GHz in transit and tracking modes Spatial fine structures superimposed on the one dimensional brightness map of the sun associated with active regions and or with solar activity and their time evolution will be presented In the second phase of the project the frequency range will be increased to 1 2 - 1 7 2 8 and 5 6 GHz Central part of the array will consist of 26 antennas with 4-meter diameter laid out randomically in the square of 256 by 256 meter with minimum and maximum base lines of 8 and 256 meters respectively Details of this array with imaging capabilities in snap shot mode for solar observations and procedure of the phase and amplitude calibrations will be presented The development of instrument will be completed by the beginning of 2008

Selective enhancement of orientation tuning before saccades.

Science.gov (United States)

Ohl, Sven; Kuper, Clara; Rolfs, Martin

2017-11-01

Saccadic eye movements cause a rapid sweep of the visual image across the retina and bring the saccade's target into high-acuity foveal vision. Even before saccade onset, visual processing is selectively prioritized at the saccade target. To determine how this presaccadic attention shift exerts its influence on visual selection, we compare the dynamics of perceptual tuning curves before movement onset at the saccade target and in the opposite hemifield. Participants monitored a 30-Hz sequence of randomly oriented gratings for a target orientation. Combining a reverse correlation technique previously used to study orientation tuning in neurons and general additive mixed modeling, we found that perceptual reports were tuned to the target orientation. The gain of orientation tuning increased markedly within the last 100 ms before saccade onset. In addition, we observed finer orientation tuning right before saccade onset. This increase in gain and tuning occurred at the saccade target location and was not observed at the incongruent location in the opposite hemifield. The present findings suggest, therefore, that presaccadic attention exerts its influence on vision in a spatially and feature-selective manner, enhancing performance and sharpening feature tuning at the future gaze location before the eyes start moving.

High-throughput controllable generation of droplet arrays with low consumption

Science.gov (United States)

Lin, Yinyin; Wu, Zhongsheng; Gao, Yibo; Wu, Jinbo; Wen, Weijia

2018-06-01

We describe a controllable sliding method for fabricating millions of isolated femto- to nanoliter-sized droplets with defined volume, geometry and position and a speed of up to 375 kHz. In this work, without using a superhydrophobic or superoleophobic surface, arrays of droplets are instantly formed on the patterned substrate by sliding a strip of liquid, including water, low-surface-tension organic solvents and solution, along the substrate. To precisely control the volume of the droplets, we systemically investigate the effects of the size of the wettable pattern, the viscosity of the liquid and sliding speed, which were found to vary independently to tune the height and volume of the droplets. Through this method, we successfully fabricated an oriented single metal-organic framework crystal array with control over their XY positioning on the surface, as characterized by microscopy and X-ray diffraction (XRD) techniques.

Engineering the on-axis intensity of Bessel beam by a feedback tuning loop

Science.gov (United States)

Li, Runze; Yu, Xianghua; Yang, Yanlong; Peng, Tong; Yao, Baoli; Zhang, Chunmin; Ye, Tong

2018-02-01

The Bessel beam belongs to a typical class of non-diffractive optical fields that are characterized by their invariant focal profiles along the propagation direction. However, ideal Bessel beams only rigorously exist in theory; Bessel beams generated in the lab are quasi-Bessel beams with finite focal extensions and varying intensity profiles along the propagation axis. The ability to engineer the on-axis intensity profile to the desired shape is essential for many applications. Here we demonstrate an iterative optimization-based approach to engineering the on-axis intensity of Bessel beams. The genetic algorithm is used to demonstrate this approach. Starting with a traditional axicon phase mask, in the design process, the computed on-axis beam profile is fed into a feedback tuning loop of an iterative optimization process, which searches for an optimal radial phase distribution that can generate a generalized Bessel beam with the desired onaxis intensity profile. The experimental implementation involves a fine-tuning process that adjusts the originally targeted profile so that the optimization process can optimize the phase mask to yield an improved on-axis profile. Our proposed method has been demonstrated in engineering several zeroth-order Bessel beams with customized on-axis profiles. High accuracy and high energy throughput merit its use in many applications.

Widespread auditory deficits in tune deafness.

Science.gov (United States)

Jones, Jennifer L; Zalewski, Christopher; Brewer, Carmen; Lucker, Jay; Drayna, Dennis

2009-02-01

The goal of this study was to investigate auditory function in individuals with deficits in musical pitch perception. We hypothesized that such individuals have deficits in nonspeech areas of auditory processing. We screened 865 randomly selected individuals to identify those who scored poorly on the Distorted Tunes test (DTT), a measure of musical pitch recognition ability. Those who scored poorly were given a comprehensive audiologic examination, and those with hearing loss or other confounding audiologic factors were excluded from further testing. Thirty-five individuals with tune deafness constituted the experimental group. Thirty-four individuals with normal hearing and normal DTT scores, matched for age, gender, handedness, and education, and without overt or reported psychiatric disorders made up the normal control group. Individual and group performance for pure-tone frequency discrimination at 1000 Hz was determined by measuring the difference limen for frequency (DLF). Auditory processing abilities were assessed using tests of pitch pattern recognition, duration pattern recognition, and auditory gap detection. In addition, we evaluated both attention and short- and long-term memory as variables that might influence performance on our experimental measures. Differences between groups were evaluated statistically using Wilcoxon nonparametric tests and t-tests as appropriate. The DLF at 1000 Hz in the group with tune deafness was significantly larger than that of the normal control group. However, approximately one-third of participants with tune deafness had DLFs within the range of performance observed in the control group. Many individuals with tune deafness also displayed a high degree of variability in their intertrial frequency discrimination performance that could not be explained by deficits in memory or attention. Pitch and duration pattern discrimination and auditory gap-detection ability were significantly poorer in the group with tune deafness

Tune splitting in the presence of linear coupling

International Nuclear Information System (INIS)

Parzen, G.

1991-01-01

The presence of random skew quadrupole field errors will couple the x and y motions. The x and y motions are then each given by the sum of 2 normal modes with the tunes v 1 and v 2 , which may differ appreciably from v x and v y , the unperturbed tunes. This is often called tune splitting since |v 1 - v 2 | is usually larger than |v x - v y |. This tune splitting may be large in proton accelerators using superconducting magnets, because of the relatively large random skew quadrupole field errors that are expected in these magnets. This effect is also increased by the required insertions in proton colliders which generate large β-functions in the insertion region. This tune splitting has been studied in the RHIC accelerator. For RHIC, a tune splitting as large as 0.2 was found in one worse case. A correction system has been developed for correcting this large tune splitting which uses two families of skew quadrupole correctors. It has been found that this correction system corrects most of the large tune splitting, but a residual tune splitting remains that is still appreciable. This paper discusses the corrections to this residual time

Telling in-tune from out-of-tune: widespread evidence for implicit absolute intonation.

Science.gov (United States)

Van Hedger, Stephen C; Heald, Shannon L M; Huang, Alex; Rutstein, Brooke; Nusbaum, Howard C

2017-04-01

Absolute pitch (AP) is the rare ability to name or produce an isolated musical note without the aid of a reference note. One skill thought to be unique to AP possessors is the ability to provide absolute intonation judgments (e.g., classifying an isolated note as "in-tune" or "out-of-tune"). Recent work has suggested that absolute intonation perception among AP possessors is not crystallized in a critical period of development, but is dynamically maintained by the listening environment, in which the vast majority of Western music is tuned to a specific cultural standard. Given that all listeners of Western music are constantly exposed to this specific cultural tuning standard, our experiments address whether absolute intonation perception extends beyond AP possessors. We demonstrate that non-AP listeners are able to accurately judge the intonation of completely isolated notes. Both musicians and nonmusicians showed evidence for absolute intonation recognition when listening to familiar timbres (piano and violin). When testing unfamiliar timbres (triangle and inverted sine waves), only musicians showed weak evidence of absolute intonation recognition (Experiment 2). Overall, these results highlight a previously unknown similarity between AP and non-AP possessors' long-term musical note representations, including evidence of sensitivity to frequency.

Apple iTunes music store

OpenAIRE

Lenzi, R.; Schmucker, M.; Spadoni, F.

2003-01-01

This technical report analyses the Apple iTunes Music Store and its success factors. Besides the technical aspects, user and customer aspects as well as content aspects are considered. Furthermore, iTunes Music Store's impact to online music distribution services is analysed and a short outlook to future music online distribution is given.

Direct electronic communication at bio-interfaces assisted by layered-metal-hydroxide slab arrays with controlled nano-micro structures.

Science.gov (United States)

An, Zhe; He, Jing

2011-10-28

The electronic transfer (eT) at bio-interfaces has been achieved by orientating 2D inorganic slabs in a regular arrangement with the slab ab-planes vertical to the electrode substrate. The eT rate is effectively promoted by tuning the nano-micro scale structures of perpendicular LDH arrays. This journal is © The Royal Society of Chemistry 2011

Site-specific nucleation and controlled growth of a vertical tellurium nanowire array for high performance field emitters

International Nuclear Information System (INIS)

Safdar, Muhammad; Zhan Xueying; Mirza, Misbah; Wang Zhenxing; Sun Lianfeng; He Jun; Niu Mutong; Zhang Jinping; Zhao Qing

2013-01-01

We report the controlled growth of highly ordered and well aligned one-dimensional tellurium nanostructure arrays via a one-step catalyst-free physical vapor deposition method. The density, size and fine structures of tellurium nanowires are systematically studied and optimized. Field emission measurement was performed to display notable dependence on nanostructure morphologies. The ordered nanowire array based field emitter has a turn-on field as low as 3.27 V μm −1 and a higher field enhancement factor of 3270. Our finding offers the possibility of controlling the growth of tellurium nanowire arrays and opens up new means for their potential applications in electronic devices and displays. (paper)

Application of genetic algorithms to tuning fuzzy control systems

Science.gov (United States)

Espy, Todd; Vombrack, Endre; Aldridge, Jack

1993-01-01

Real number genetic algorithms (GA) were applied for tuning fuzzy membership functions of three controller applications. The first application is our 'Fuzzy Pong' demonstration, a controller that controls a very responsive system. The performance of the automatically tuned membership functions exceeded that of manually tuned membership functions both when the algorithm started with randomly generated functions and with the best manually-tuned functions. The second GA tunes input membership functions to achieve a specified control surface. The third application is a practical one, a motor controller for a printed circuit manufacturing system. The GA alters the positions and overlaps of the membership functions to accomplish the tuning. The applications, the real number GA approach, the fitness function and population parameters, and the performance improvements achieved are discussed. Directions for further research in tuning input and output membership functions and in tuning fuzzy rules are described.

Evolutionarily Conserved, Growth Plate Zone-Specific Regulation of the Matrilin-1 Promoter: L-Sox5/Sox6 and Nfi Factors Bound near TATA Finely Tune Activation by Sox9 ▿

Science.gov (United States)

Nagy, Andrea; Kénesi, Erzsébet; Rentsendorj, Otgonchimeg; Molnár, Annamária; Szénási, Tibor; Sinkó, Ildikó; Zvara, Ágnes; Thottathil Oommen, Sajit; Barta, Endre; Puskás, László G.; Lefebvre, Veronique; Kiss, Ibolya

2011-01-01

To help uncover the mechanisms underlying the staggered expression of cartilage-specific genes in the growth plate, we dissected the transcriptional mechanisms driving expression of the matrilin-1 gene (Matn1). We show that a unique assembly of evolutionarily conserved cis-acting elements in the Matn1 proximal promoter restricts expression to the proliferative and prehypertrophic zones of the growth plate. These elements functionally interact with distal elements and likewise are capable of restricting the domain of activity of a pancartilaginous Col2a1 enhancer. The proximal elements include a Pe1 element binding the chondrogenic L-Sox5, Sox6, and Sox9 proteins, a SI element binding Nfi proteins, and an initiator Ine element binding the Sox trio and other factors. Sox9 binding to Pe1 is indispensable for functional interaction with the distal promoter. Binding of L-Sox5/Sox6 to Ine and Nfib to SI modulates Sox9 transactivation in a protein dose-dependent manner, possibly to enhance Sox9 activity in early stages of chondrogenesis and repress it at later stages. Hence, our data suggest a novel model whereby Sox and Nfi proteins bind to conserved Matn1 proximal elements and functionally interact with each other to finely tune gene expression in specific zones of the cartilage growth plate. PMID:21173167

A multi-step method with signal quality assessment and fine-tuning procedure to locate maternal and fetal QRS complexes from abdominal ECG recordings

International Nuclear Information System (INIS)

Liu, Chengyu; Li, Peng; Zhao, Lina; Di Maria, Costanzo; Zhang, Henggui; Chen, Zhiqing

2014-01-01

Non-invasive monitoring of fetal electrocardiogram (fECG) plays an important role in detecting and diagnosing fetal diseases. This study aimed to develop a multi-step method for locating both maternal and fetal QRS complexes from abdominal ECG (aECG) recordings. The proposed method included four major steps: abdominal ECG pre-processing, maternal QRS complex locating, maternal ECG cancellation and fetal QRS complex locating. Signal quality assessment (SQA) and fine-tuning for maternal ECG (FTM) were implemented in the first and third steps, respectively. The method was then evaluated using 75 non-invasive 4-channel aECG recordings provided by the PhysioNet/Computing in Cardiology Challenge 2013. The F 1 measure, which is a new index introduced by Behar et al (2013 Proc. Comput. Cardiol. 40 297–300), was used to assess the locating accuracy. The other two indices, mean squared error of heart rate (MSE H R) between the fetal HR signals estimated from the reference and our method (MSE H R in bpm 2 ) and root mean squared difference between the corresponding fetal RR intervals (MSE R R in ms) were also used to assess the locating accuracy. Overall, for the maternal QRS complex, the F 1 measure was 98.4% from the method without the implementation of SQA, and it was improved to 99.8% with SQA. For the fetal QRS complex, the F 1 measure, MSE H R and MSE R R were 84.9%, 185.6 bpm 2 and 19.4 ms for the method without both SQA and FTM procedures. They were improved to 93.9%, 47.5 bpm 2 and 7.6 ms with both SQA and FTM procedures. These improvements were observed from each individual subject. It can be concluded that implementing both SQA and FTM procedures could achieve better performance for locating both maternal and fetal QRS complexes. (paper)

A mechanism for tuning 5 GHz HTS filters

Energy Technology Data Exchange (ETDEWEB)

Ohsaka, M.; Takeuchi, S.; Ono, S.; Lee, J.H.; Saito, A. [Department of Electrical Engineering, Yamagata University, 4-3-16 Johnan, Yonezawa 992-8510 (Japan); Akasegawa, A.; Yamanaka, K.; Kurihara, K. [Fujitsu LTD., 10-1 Wakamiya, Morinosato, Atsugi, Kanagawa 243-0197 (Japan); Ohshima, S. [Department of Electrical Engineering, Yamagata University, 4-3-16 Johnan, Yonezawa 992-8510 (Japan)], E-mail: ohshima@yz.yamagata-u.ac.jp

2008-09-15

We developed a tuning mechanism of HTS filter with a dielectric tuning plate, dielectric trimming rods, and conducting trimming rods. The tuning plate has windows through which the dielectric and conducting trimming rods pass. The tuning plate was designed for a 3-pole filter with 5 GHz center frequency (f{sub c}) and 100 MHz bandwidth (BW) using a 3-dimensional electromagnetic simulator. We were able to shift the f{sub c} to frequencies below 500 MHz using the tuning plate with a dielectric constant of 45. However, the insertion loss (IL) and the pass-band ripple of the filter became more severe and the BW of the filter was narrower after tuning. We tried to improve the filter properties after tuning using the dielectric and conducting trimming rods. We decreased the IL and the pass-band ripple by adjusting the height of the dielectric trimming rods to above the resonators. Also, the BW was improved by using copper (Cu) trimming rods above the spaces between the resonators. The tuning plate and the trimming rods did not affect the IL. So, we simulated 500 MHz tuning without the filter properties deteriorating at f{sub c} = 5 GHz. Also, we experimentally evaluated that the f{sub c} could be shifted to 340 MHz using the dielectric plate, the pass-band ripple could be decreased by ripple trimming using the dielectric rods, and the BW could be increased 31 MHz by BW trimming using the Cu rods.

Using financial futures in trading and risk management

OpenAIRE

Mas, Ignacio; Saa-Requejo, Jesus

1995-01-01

The authors explain the features of an array of futures contracts and their basic pricing relationships and describe a few applications to show how investors and risk managers can use these contracts. Futures - and derivatives generally - allow economic agents to fine-tune the structure of their assets and liabilities to suit their risk preferences and market expectations. Futures are not a financing or investment vehicle per se, but a tool for transferring price risks associated with fluctua...

Fine Tuning of CaV1.3 Ca2+ channel properties in adult inner hair cells positioned in the most sensitive region of the Gerbil Cochlea.

Directory of Open Access Journals (Sweden)

Valeria Zampini

Full Text Available Hearing relies on faithful signal transmission by cochlear inner hair cells (IHCs onto auditory fibres over a wide frequency and intensity range. Exocytosis at IHC ribbon synapses is triggered by Ca(2+ inflow through Ca(V1.3 (L-type Ca(2+ channels. We investigated the macroscopic (whole-cell and elementary (cell-attached properties of Ca(2+ currents in IHCs positioned at the middle turn (frequency ∼ 2 kHz of the adult gerbil cochlea, which is their most sensitive hearing region. Using near physiological recordings conditions (body temperature and a Na(+ based extracellular solution, we found that the macroscopic Ca(2+ current activates and deactivates very rapidly (time constant below 1 ms and inactivates slowly and only partially. Single-channel recordings showed an elementary conductance of 15 pS, a sub-ms latency to first opening, and a very low steady-state open probability (Po: 0.024 in response to 500-ms depolarizing steps at ∼-18 mV. The value of Po was significantly larger (0.06 in the first 40 ms of membrane depolarization, which corresponds to the time when most Ca(2+ channel openings occurred clustered in bursts (mean burst duration: 19 ms. Both the Po and the mean burst duration were smaller than those previously reported in high-frequency basal IHCs. Finally, we found that middle turn IHCs are likely to express about 4 times more Ca(2+ channels per ribbon than basal cells. We propose that middle-turn IHCs finely-tune Ca(V1.3 Ca(2+ channel gating in order to provide reliable information upon timing and intensity of lower-frequency sounds.

Fine Tuning of CaV1.3 Ca2+ channel properties in adult inner hair cells positioned in the most sensitive region of the Gerbil Cochlea.

Science.gov (United States)

Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Knipper, Marlies; Holley, Matthew C; Magistretti, Jacopo; Russo, Giancarlo; Marcotti, Walter; Masetto, Sergio

2014-01-01

Hearing relies on faithful signal transmission by cochlear inner hair cells (IHCs) onto auditory fibres over a wide frequency and intensity range. Exocytosis at IHC ribbon synapses is triggered by Ca(2+) inflow through Ca(V)1.3 (L-type) Ca(2+) channels. We investigated the macroscopic (whole-cell) and elementary (cell-attached) properties of Ca(2+) currents in IHCs positioned at the middle turn (frequency ∼ 2 kHz) of the adult gerbil cochlea, which is their most sensitive hearing region. Using near physiological recordings conditions (body temperature and a Na(+) based extracellular solution), we found that the macroscopic Ca(2+) current activates and deactivates very rapidly (time constant below 1 ms) and inactivates slowly and only partially. Single-channel recordings showed an elementary conductance of 15 pS, a sub-ms latency to first opening, and a very low steady-state open probability (Po: 0.024 in response to 500-ms depolarizing steps at ∼-18 mV). The value of Po was significantly larger (0.06) in the first 40 ms of membrane depolarization, which corresponds to the time when most Ca(2+) channel openings occurred clustered in bursts (mean burst duration: 19 ms). Both the Po and the mean burst duration were smaller than those previously reported in high-frequency basal IHCs. Finally, we found that middle turn IHCs are likely to express about 4 times more Ca(2+) channels per ribbon than basal cells. We propose that middle-turn IHCs finely-tune Ca(V)1.3 Ca(2+) channel gating in order to provide reliable information upon timing and intensity of lower-frequency sounds.

High-volume image quality assessment systems: tuning performance with an interactive data visualization tool

Science.gov (United States)

Bresnahan, Patricia A.; Pukinskis, Madeleine; Wiggins, Michael

1999-03-01

Image quality assessment systems differ greatly with respect to the number and types of mags they need to evaluate, and their overall architectures. Managers of these systems, however, all need to be able to tune and evaluate system performance, requirements often overlooked or under-designed during project planning. Performance tuning tools allow users to define acceptable quality standards for image features and attributes by adjusting parameter settings. Performance analysis tools allow users to evaluate and/or predict how well a system performs in a given parameter state. While image assessment algorithms are becoming quite sophisticated, duplicating or surpassing the human decision making process in their speed and reliability, they often require a greater investment in 'training' or fine tuning of parameters in order to achieve optimum performance. This process may involve the analysis of hundreds or thousands of images, generating a large database of files and statistics that can be difficult to sort through and interpret. Compounding the difficulty is the fact that personnel charged with tuning and maintaining the production system may not have the statistical or analytical background required for the task. Meanwhile, hardware innovations have greatly increased the volume of images that can be handled in a given time frame, magnifying the consequences of running a production site with an inadequately tuned system. In this paper, some general requirements for a performance evaluation and tuning data visualization system are discussed. A custom engineered solution to the tuning and evaluation problem is then presented, developed within the context of a high volume image quality assessment, data entry, OCR, and image archival system. A key factor influencing the design of the system was the context-dependent definition of image quality, as perceived by a human interpreter. This led to the development of a five-level, hierarchical approach to image quality

Summary of ATLAS Pythia 8 tunes

CERN Document Server

The ATLAS collaboration

2012-01-01

We summarize the latest ATLAS Pythia 8 minimum bias and underlying event tunes. The Pythia 8 MPI tunes in this note have been constructed for nine different PDFs, making use of a new x-dependent hadronic matter distribution model.

An electrically tunable plenoptic camera using a liquid crystal microlens array

International Nuclear Information System (INIS)

Lei, Yu; Tong, Qing; Zhang, Xinyu; Sang, Hongshi; Ji, An; Xie, Changsheng

2015-01-01

Plenoptic cameras generally employ a microlens array positioned between the main lens and the image sensor to capture the three-dimensional target radiation in the visible range. Because the focal length of common refractive or diffractive microlenses is fixed, the depth of field (DOF) is limited so as to restrict their imaging capability. In this paper, we propose a new plenoptic camera using a liquid crystal microlens array (LCMLA) with electrically tunable focal length. The developed LCMLA is fabricated by traditional photolithography and standard microelectronic techniques, and then, its focusing performance is experimentally presented. The fabricated LCMLA is directly integrated with an image sensor to construct a prototyped LCMLA-based plenoptic camera for acquiring raw radiation of targets. Our experiments demonstrate that the focused region of the LCMLA-based plenoptic camera can be shifted efficiently through electrically tuning the LCMLA used, which is equivalent to the extension of the DOF

In response to partial plant shading, the lack of phytochrome A does not directly induce leaf senescence but alters the fine-tuning of chlorophyll biosynthesis

Science.gov (United States)

Brouwer, Bastiaan; Gardeström, Per; Keech, Olivier

2014-01-01

Phytochrome is thought to control the induction of leaf senescence directly, however, the signalling and molecular mechanisms remain unclear. In the present study, an ecophysiological approach was used to establish a functional connection between phytochrome signalling and the physiological processes underlying the induction of leaf senescence in response to shade. With shade it is important to distinguish between complete and partial shading, during which either the whole or only a part of the plant is shaded, respectively. It is first shown here that, while PHYB is required to maintain chlorophyll content in a completely shaded plant, only PHYA is involved in maintaining the leaf chlorophyll content in response to partial plant shading. Second, it is shown that leaf yellowing associated with strong partial shading in phyA-mutant plants actually correlates to a decreased biosynthesis of chlorophyll rather than to an increase of its degradation. Third, it is shown that the physiological impact of this decreased biosynthesis of chlorophyll in strongly shaded phyA-mutant leaves is accompanied by a decreased capacity to adjust the Light Compensation Point. However, the increased leaf yellowing in phyA-mutant plants is not accompanied by an increase of senescence-specific molecular markers, which argues against a direct role of PHYA in inducing leaf senescence in response to partial shade. In conclusion, it is proposed that PHYA, but not PHYB, is essential for fine-tuning the chlorophyll biosynthetic pathway in response to partial shading. In turn, this mechanism allows the shaded leaf to adjust its photosynthetic machinery to very low irradiances, thus maintaining a positive carbon balance and repressing the induction of leaf senescence, which can occur under prolonged periods of shade. PMID:24604733

Angular plasmon response of gold nanoparticles arrays: approaching the Rayleigh limit

Directory of Open Access Journals (Sweden)

Marae-Djouda Joseph

2016-07-01

Full Text Available The regular arrangement of metal nanoparticles influences their plasmonic behavior. It has been previously demonstrated that the coupling between diffracted waves and plasmon modes can give rise to extremely narrow plasmon resonances. This is the case when the single-particle localized surface plasmon resonance (λLSP is very close in value to the Rayleigh anomaly wavelength (λRA of the nanoparticles array. In this paper, we performed angle-resolved extinction measurements on a 2D array of gold nano-cylinders designed to fulfil the condition λRA<λLSP. Varying the angle of excitation offers a unique possibility to finely modify the value of λRA, thus gradually approaching the condition of coupling between diffracted waves and plasmon modes. The experimental observation of a collective dipolar resonance has been interpreted by exploiting a simplified model based on the coupling of evanescent diffracted waves with plasmon modes. Among other plasmon modes, the measurement technique has also evidenced and allowed the study of a vertical plasmon mode, only visible in TM polarization at off-normal excitation incidence. The results of numerical simulations, based on the periodic Green’s tensor formalism, match well with the experimental transmission spectra and show fine details that could go unnoticed by considering only experimental data.

Construction of 3D Metallic Nanowire Arrays on Arbitrarily-Shaped Substrate.

Science.gov (United States)

Chen, Fei; Li, Jingning; Yu, Fangfang; Peng, Ru-Wen; Wang, Mu; Mu Wang Team

Formation of three-dimensional (3D) nanostructures is an important step of advanced manufacture for new concept devices with novel functionality. Despite of great achievements in fabricating nanostructures with state of the art lithography approaches, these nanostructures are normally limited on flat substrates. Up to now it remains challenging to build metallic nanostructures directly on a rough and bumpy surface. Here we demonstrate a unique approach to fabricate metallic nanowire arrays on an arbitrarily-shaped surface by electrodeposition, which is unknown before 2016. Counterintuitively here the growth direction of the nanowires is perpendicular to their longitudinal axis, and the specific geometry of nanowires can be achieved by introducing specially designed shaped substrate. The spatial separation and the width of the nanowires can be tuned by voltage, electrolyte concentration and temperature in electrodeposition. By taking cobalt nanowire array as an example, we demonstrate that head-to-head and tail-to-tail magnetic domain walls can be easily introduced and modulated in the nanowire arrays, which is enlightening to construct new devices such as domain wall racetrack memory. We acknowledge the foundation from MOST and NSF(China).

Frequency Tuning of Vibration Absorber Using Topology Optimization

Science.gov (United States)

Harel, Swapnil Subhash

A tuned mass absorber is a system for reducing the amplitude in one oscillator by coupling it to a second oscillator. If tuned correctly, the maximum amplitude of the first oscillator in response to a periodic driver will be lowered, and much of the vibration will be 'transferred' to the second oscillator. The tuned vibration absorber (TVA) has been utilized for vibration control purposes in many sectors of Civil/Automotive/Aerospace Engineering for many decades since its inception. Time and again we come across a situation in which a vibratory system is required to run near resonance. In the past, approaches have been made to design such auxiliary spring mass tuned absorbers for the safety of the structures. This research focuses on the development and optimization of continuously tuned mass absorbers as a substitute to the discretely tuned mass absorbers (spring- mass system). After conducting the study of structural behavior, the boundary condition and frequency to which the absorber is to be tuned are determined. The Modal analysis approach is used to determine mode shapes and frequencies. The absorber is designed and optimized using the topology optimization tool, which simultaneously designs, optimizes and tunes the absorber to the desired frequency. The tuned, optimized absorber, after post processing, is attached to the target structure. The number of the absorbers are increased to amplify bandwidth and thereby upgrade the safety of structure for a wide range of frequency. The frequency response analysis is carried out using various combinations of structure and number of absorber cell.

Sahara Coal: the fine art of collecting fines for profit

Energy Technology Data Exchange (ETDEWEB)

Schreckengost, D.; Arnold, D.

1984-09-01

A considerable increase in the volume of fines in rom coal caused Sahara Coal in Illinois to redesign the fine coal system in their Harrisburg preparation plant. Details of the new design, and particularly the fine refuse system which dewaters and dries 28 mesh x O clean coal, are given. Results have exceeded expectations in reducing product losses, operating costs and slurry pond cleaning costs.

The Effect of Fin Pitch on Fluid Elastic Instability of Tube Arrays Subjected to Cross Flow of Water

Science.gov (United States)

Desai, Sandeep Rangrao; Pavitran, Sampat

2018-02-01

Failure of tubes in shell and tube exchangers is attributed to flow induced vibrations of such tubes. There are different excitations mechanisms due to which flow induced vibration occurs and among such mechanisms, fluid elastic instability is the most prominent one as it causes the most violent vibrations and may lead to rapid tube failures within short time. Fluid elastic instability is the fluid-structure interaction phenomenon which occurs when energy input by the fluid force exceeds energy expended in damping. This point is referred as instability threshold and corresponding velocity is referred as critical velocity. Once flow velocity exceeds critical flow velocity, the vibration amplitude increases very rapidly with flow velocity. An experimental program is carried out to determine the critical velocity at instability for plain and finned tube arrays subjected to cross flow of water. The tube array geometry is parallel triangular with cantilever end condition and pitch ratios considered are 2.6 and 2.1. The objective of research is to determine the effect of increase in pitch ratio on instability threshold for plain tube arrays and to assess the effect of addition of fins as well as increase in fin density on instability threshold for finned tube arrays. Plain tube array with two different pitch ratios; 2.1 and 2.6 and finned tube arrays with same pitch ratio; 2.6 but with two different fin pitches; such as fine (10 fpi) and coarse (4 fpi) are considered for the experimentation. Connors' equation that relates critical velocity at instability to different parameters, on which instability depends, has been used as the basis for analysis and the concept of effective diameter is used for the present investigation. The modal parameters are first suitably modified using natural frequency reduction setup that is already designed and developed to reduce natural frequency and hence to achieve experimental simulation of fluid elastic instability within the limited

An Array of Optical Receivers for Deep-Space Communications

Science.gov (United States)

Vilnrotter, Chi-Wung; Srinivasan, Meera; Andrews, Kenneth

2007-01-01

An array of small optical receivers is proposed as an alternative to a single large optical receiver for high-data-rate communications in NASA s Deep Space Network (DSN). Because the telescope for a single receiver capable of satisfying DSN requirements must be greater than 10 m in diameter, the design, building, and testing of the telescope would be very difficult and expensive. The proposed array would utilize commercially available telescopes of 1-m or smaller diameter and, therefore, could be developed and verified with considerably less difficulty and expense. The essential difference between a single-aperture optical-communications receiver and an optical-array receiver is that a single-aperture receiver focuses all of the light energy it collects onto the surface of an optical detector, whereas an array receiver focuses portions of the total collected energy onto separate detectors, optically detects each fractional energy component, then combines the electrical signal from the array of detector outputs to form the observable, or "decision statistic," used to decode the transmitted data. A conceptual block diagram identifying the key components of the optical-array receiver suitable for deep-space telemetry reception is shown in the figure. The most conspicuous feature of the receiver is the large number of small- to medium-size telescopes, with individual apertures and number of telescopes selected to make up the desired total collecting area. This array of telescopes is envisioned to be fully computer- controlled via the user interface and prediction-driven to achieve rough pointing and tracking of the desired spacecraft. Fine-pointing and tracking functions then take over to keep each telescope pointed toward the source, despite imperfect pointing predictions, telescope-drive errors, and vibration caused by wind.

Efficient tuning in supervised machine learning

NARCIS (Netherlands)

Koch, Patrick

2013-01-01

The tuning of learning algorithm parameters has become more and more important during the last years. With the fast growth of computational power and available memory databases have grown dramatically. This is very challenging for the tuning of parameters arising in machine learning, since the

Dynamic Performance Tuning Supported by Program Specification

Directory of Open Access Journals (Sweden)

Eduardo César

2002-01-01

Full Text Available Performance analysis and tuning of parallel/distributed applications are very difficult tasks for non-expert programmers. It is necessary to provide tools that automatically carry out these tasks. These can be static tools that carry out the analysis on a post-mortem phase or can tune the application on the fly. Both kind of tools have their target applications. Static automatic analysis tools are suitable for stable application while dynamic tuning tools are more appropriate to applications with dynamic behaviour. In this paper, we describe KappaPi as an example of a static automatic performance analysis tool, and also a general environment based on parallel patterns for developing and dynamically tuning parallel/distributed applications.

A tuning method for nonuniform traveling-wave accelerating structures

International Nuclear Information System (INIS)

Gong Cunkui; Zheng Shuxin; Shao Jiahang; Jia Xiaoyu; Chen Huaibi

2013-01-01

The tuning method of uniform traveling-wave structures based on non-resonant perturbation field distribution measurement has been widely used in tuning both constant-impedance and constant-gradient structures. In this paper, the method of tuning nonuniform structures is proposed on the basis of the above theory. The internal reflection coefficient of each cell is obtained from analyzing the normalized voltage distribution. A numerical simulation of tuning process according to the coupled cavity chain theory has been done and the result shows each cell is in right phase advance after tuning. The method will be used in the tuning of a disk-loaded traveling-wave structure being developed at the Accelerator Laboratory, Tsinghua University. (authors)

Uniform irradiation of adjustable target spots in high-power laser driver

International Nuclear Information System (INIS)

Jiang Xiujuan; Li Jinghui; Li Huagang; Li Yang; Lin Zunqi

2011-01-01

For smoothing and shaping the on-target laser patterns flexibly in high-power laser drivers, a scheme has been developed that includes a zoom lens array and two-dimensional smoothing by spectral dispersion (SSD). The size of the target pattern can be controlled handily by adjusting the focal length of the zoom lens array, while the profile of the pattern can be shaped by fine tuning the distance between the target and the focal plane of the principal focusing lens. High-frequency stripes inside the pattern caused by beamlet interference are wiped off by spectral dispersion. Detailed simulations indicate that SSD works somewhat differently for spots of different sizes. For small spots, SSD mainly smooths the intensity modulation of low-to-middle spatial frequency, while for large spots, SSD sweeps the fine speckle structure to reduce nonuniformity of middle-to-high frequency. Spatial spectra of the target patterns are given and their uniformity is evaluated.

Diameter- and current-density-dependent growth orientation of hexagonal CdSe nanowire arrays via electrodeposition

International Nuclear Information System (INIS)

Sun Hongyu; Li Xiaohong; Chen Yan; Guo Defeng; Xie Yanwu; Li Wei; Zhang Xiangyi; Liu Baoting

2009-01-01

Controlling the growth orientation of semiconductor nanowire arrays is of vital importance for their applications in the fields of nanodevices. In the present work, hexagonal CdSe nanowire arrays with various preferential growth orientations have been successfully yielded by employing the electrodeposition technique using porous alumina as templates (PATs). We demonstrate by experimental and theoretical efforts that the growth orientation of the CdSe nanowires can be effectively manipulated by varying either the nanopore diameter of the PATs or the deposited current density, which has significant effects on the optical properties of the CdSe nanowires. The present study provides an alternative approach to tuning the growth direction of electrodeposited nanowires and thus is of importance for the fabrication of nanodevices with controlled functional properties.

Diameter- and current-density-dependent growth orientation of hexagonal CdSe nanowire arrays via electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Sun Hongyu; Li Xiaohong; Chen Yan; Guo Defeng; Xie Yanwu; Li Wei; Zhang Xiangyi [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu Baoting, E-mail: xyzh66@ysu.edu.c [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

2009-10-21

Controlling the growth orientation of semiconductor nanowire arrays is of vital importance for their applications in the fields of nanodevices. In the present work, hexagonal CdSe nanowire arrays with various preferential growth orientations have been successfully yielded by employing the electrodeposition technique using porous alumina as templates (PATs). We demonstrate by experimental and theoretical efforts that the growth orientation of the CdSe nanowires can be effectively manipulated by varying either the nanopore diameter of the PATs or the deposited current density, which has significant effects on the optical properties of the CdSe nanowires. The present study provides an alternative approach to tuning the growth direction of electrodeposited nanowires and thus is of importance for the fabrication of nanodevices with controlled functional properties.

Iterative Feedback Tuning in district heating systems; Iterative Feedback Tuning i vaermeproduktionsanlaeggningar

Energy Technology Data Exchange (ETDEWEB)

Raaberg, Martin; Velut, Stephane; Bari, Siavosh Amanat

2010-10-15

The project goal is to evaluate and describe how Iterative Feedback Tuning (IFT) can be used to tune controllers in the typical control loops in heat- and power plants. There are only a few practical studies carried out for IFT and they are not really relevant for power and heat processes. It is the practical problems in implementing the IFT and the result of trimming that is the focus of this project. The project will start with theoretical studies of the IFT-method, then realization and simple simulations in scilab. The IFT equations are then implemented in Freelance 2000, an ABB control system, for practical tests on a SISO- and a MIMO-process. By performing reproducible experiments on the process and analyze the results IFT can adjust the controller parameters to minimize a cost function that represents the control goal. The project selected for SISO experiments a pressure controller in an oil transportation system. By controlling the valve position of a control valve for the reversal to the supply tank, the pressure in the oil transport system is regulated. A disturbance in oil pressure can be achieved by changing the position of a valve that lets oil through to the day tank. The selected MIMO-process is a pre-heater in a degassing process. In this process, a valve on the secondary side is utilized to control the flow in the secondary system. A valve on the primary side is utilized to control the district heating water flow through the heat exchanger to control the temperature on the secondary side. An increased secondary flow increases the heat demand and thus requiring an increase in primary flow to maintain the secondary side outlet temperature. This is the cross-coupling responsible for why it is an advantage to consider the process as multi-variable. Using the IFT method, the two original PID-controllers and a feed-forward controller is tuned simultaneously. IFT-method was difficult to implement but worked well in both simulations and in real processes

Small Commercial Building Re-tuning: A Primer

Energy Technology Data Exchange (ETDEWEB)

Cort, Katherine A.; Hostick, Donna J.; Underhill, Ronald M.; Fernandez, Nicholas; Katipamula, Srinivas

2013-09-30

To help building owners and managers address issues related to energy-efficient operation of small buildings, DOE has developed a Small Building Re-tuning training curriculum. This "primer" provides additional background information to understand some of the concepts presented in the Small Building Re-tuning training. The intent is that those who are less familiar with the buidling energy concepts will review this material before taking the building re-tuning training class.

Oracle SQL Tuning pocket Reference

CERN Document Server

Gurry, Mark

2002-01-01

One of the most important challenges faced by Oracle database administrators and Oracle developers is the need to tune SQL statements so that they execute efficiently. Poorly tuned SQL statements are one of the leading causes of substandard database performance and poor response time. SQL statements that perform poorly result in frustration for users, and can even prevent a company from serving its customers in a timely manner

Deep Learning versus Professional Healthcare Equipment: A Fine-Grained Breathing Rate Monitoring Model

Directory of Open Access Journals (Sweden)

Bang Liu

2018-01-01

Full Text Available In mHealth field, accurate breathing rate monitoring technique has benefited a broad array of healthcare-related applications. Many approaches try to use smartphone or wearable device with fine-grained monitoring algorithm to accomplish the task, which can only be done by professional medical equipment before. However, such schemes usually result in bad performance in comparison to professional medical equipment. In this paper, we propose DeepFilter, a deep learning-based fine-grained breathing rate monitoring algorithm that works on smartphone and achieves professional-level accuracy. DeepFilter is a bidirectional recurrent neural network (RNN stacked with convolutional layers and speeded up by batch normalization. Moreover, we collect 16.17 GB breathing sound recording data of 248 hours from 109 and another 10 volunteers to train and test our model, respectively. The results show a reasonably good accuracy of breathing rate monitoring.

Stress-tuned conductor-polymer composite for use in sensors

Science.gov (United States)

Martin, James E; Read, Douglas H

2013-10-22

A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.

Making oxidation potentials predictable: Coordination of additives applied to the electronic fine tuning of an iron(II) complex

KAUST Repository

Haslinger, Stefan

2014-11-03

This work examines the impact of axially coordinating additives on the electronic structure of a bioinspired octahedral low-spin iron(II) N-heterocyclic carbene (Fe-NHC) complex. Bearing two labile trans-acetonitrile ligands, the Fe-NHC complex, which is also an excellent oxidation catalyst, is prone to axial ligand exchange. Phosphine- and pyridine-based additives are used for substitution of the acetonitrile ligands. On the basis of the resulting defined complexes, predictability of the oxidation potentials is demonstrated, based on a correlation between cyclic voltammetry experiments and density functional theory calculated molecular orbital energies. Fundamental insights into changes of the electronic properties upon axial ligand exchange and the impact on related attributes will finally lead to target-oriented manipulation of the electronic properties and consequently to the effective tuning of the reactivity of bioinspired systems.

Making oxidation potentials predictable: Coordination of additives applied to the electronic fine tuning of an iron(II) complex

KAUST Repository

Haslinger, Stefan; Kü ck, Jens W.; Hahn, Eva M.; Cokoja, Mirza; Pö thig, Alexander; Basset, Jean-Marie; Kü hn, Fritz

2014-01-01

This work examines the impact of axially coordinating additives on the electronic structure of a bioinspired octahedral low-spin iron(II) N-heterocyclic carbene (Fe-NHC) complex. Bearing two labile trans-acetonitrile ligands, the Fe-NHC complex, which is also an excellent oxidation catalyst, is prone to axial ligand exchange. Phosphine- and pyridine-based additives are used for substitution of the acetonitrile ligands. On the basis of the resulting defined complexes, predictability of the oxidation potentials is demonstrated, based on a correlation between cyclic voltammetry experiments and density functional theory calculated molecular orbital energies. Fundamental insights into changes of the electronic properties upon axial ligand exchange and the impact on related attributes will finally lead to target-oriented manipulation of the electronic properties and consequently to the effective tuning of the reactivity of bioinspired systems.

New ATLAS event generator tunes to 2010 data

CERN Document Server

The ATLAS collaboration

2011-01-01

This note describes the Monte Carlo event generator tunings for the Pythia 6 and Herwig/Jimmy generators in the ATLAS MC11 simulation production. New tunes have been produced for these generators, making maximal use of available published data from ATLAS and from the Tevatron and LEP experiments. Particular emphasis has been placed on improvement of the description of e+ e− event shape and jet rate data, and on description of hadron collider event shape observables in Pythia, as well as the established procedure of tuning the multiple parton interactions of both models to describe underlying event and minimum bias data. The tuning of Pythia is provided at this time for the MRST LO∗∗ PDF, while the purely MPI tune of Herwig/Jimmy is performed for ten different PDFs.

The insulator protein SU(HW fine-tunes nuclear lamina interactions of the Drosophila genome.

Directory of Open Access Journals (Sweden)

Joke G van Bemmel

Full Text Available Specific interactions of the genome with the nuclear lamina (NL are thought to assist chromosome folding inside the nucleus and to contribute to the regulation of gene expression. High-resolution mapping has recently identified hundreds of large, sharply defined lamina-associated domains (LADs in the human genome, and suggested that the insulator protein CTCF may help to demarcate these domains. Here, we report the detailed structure of LADs in Drosophila cells, and investigate the putative roles of five insulator proteins in LAD organization. We found that the Drosophila genome is also organized in discrete LADs, which are about five times smaller than human LADs but contain on average a similar number of genes. Systematic comparison to new and published insulator binding maps shows that only SU(HW binds preferentially at LAD borders and at specific positions inside LADs, while GAF, CTCF, BEAF-32 and DWG are mostly absent from these regions. By knockdown and overexpression studies we demonstrate that SU(HW weakens genome - NL interactions through a local antagonistic effect, but we did not obtain evidence that it is essential for border formation. Our results provide insights into the evolution of LAD organization and identify SU(HW as a fine-tuner of genome - NL interactions.

An Ultra-High Element Density pMUT Array with Low Crosstalk for 3-D Medical Imaging

Directory of Open Access Journals (Sweden)

Tian-Ling Ren

2013-07-01

Full Text Available A ~1 MHz piezoelectric micromachined ultrasonic transducer (pMUT array with ultra-high element density and low crosstalk is proposed for the first time. This novel pMUT array is based on a nano-layer spin-coating lead zirconium titanium film technique and can be fabricated with high element density using a relatively simple process. Accordingly, key fabrication processes such as thick piezoelectric film deposition, low-stress Si-SOI bonding and bulk silicon removal have been successfully developed. The novel fine-pitch 6 × 6 pMUT arrays can all work at the desired frequency (~1 MHz with good uniformity, high performance and potential IC integration compatibility. The minimum interspace is ~20 μm, the smallest that has ever been achieved to the best of our knowledge. These arrays can be potentially used to steer ultrasound beams and implement high quality 3-D medical imaging applications.

Tuning and History: A Personal Overview

Science.gov (United States)

Isaacs, Ann Katherine

2017-01-01

The text places Tuning History in the context of the rapidly developing international collaboration among historians which began in Europe in 1989, with the ECTS Pilot project, and continued, from 2000 on, with the European History Networks (for research and for curriculum development) working in parallel and in collaboration with Tuning, in…

ICRF array module development and optimization for high power density

International Nuclear Information System (INIS)

Ryan, P.M.; Swain, D.W.

1997-02-01

This report describes the analysis and optimization of the proposed International Thermonuclear Experimental Reactor (ITER) Antenna Array for the ion cyclotron range of frequencies (ICRF). The objectives of this effort were to: (1) minimize the applied radiofrequency rf voltages occurring in vacuum by proper layout and shape of components, limit the component's surface/volumes where the rf voltage is high; (2) study the effects of magnetic insulation, as applied to the current design; (3) provide electrical characteristics of the antenna for the development and analysis of tuning, arc detection/suppression, and systems for discriminating between arcs and edge-localized modes (ELMs); (4) maintain close interface with mechanical design

Linear beam-beam tune shift calculations for the Tevatron Collider

International Nuclear Information System (INIS)

Johnson, D.

1989-01-01

A realistic estimate of the linear beam-beam tune shift is necessary for the selection of an optimum working point in the tune diagram. Estimates of the beam-beam tune shift using the ''Round Beam Approximation'' (RBA) have over estimated the tune shift for the Tevatron. For a hadron machine with unequal lattice functions and beam sizes, an explicit calculation using the beam size at the crossings is required. Calculations for various Tevatron lattices used in Collider operation are presented. Comparisons between the RBA and the explicit calculation, for elliptical beams, are presented. This paper discusses the calculation of the linear tune shift using the program SYNCH. Selection of a working point is discussed. The magnitude of the tune shift is influenced by the choice of crossing points in the lattice as determined by the pbar ''cogging effects''. Also discussed is current cogging procedures and presents results of calculations for tune shifts at various crossing points in the lattice. Finally, a comparison of early pbar tune measurements with the present linear tune shift calculations is presented. 17 refs., 13 figs., 3 tabs

Array capabilities and future arrays

International Nuclear Information System (INIS)

Radford, D.

1993-01-01

Early results from the new third-generation instruments GAMMASPHERE and EUROGAM are confirming the expectation that such arrays will have a revolutionary effect on the field of high-spin nuclear structure. When completed, GAMMASHPERE will have a resolving power am order of magnitude greater that of the best second-generation arrays. When combined with other instruments such as particle-detector arrays and fragment mass analysers, the capabilites of the arrays for the study of more exotic nuclei will be further enhanced. In order to better understand the limitations of these instruments, and to design improved future detector systems, it is important to have some intelligible and reliable calculation for the relative resolving power of different instrument designs. The derivation of such a figure of merit will be briefly presented, and the relative sensitivities of arrays currently proposed or under construction presented. The design of TRIGAM, a new third-generation array proposed for Chalk River, will also be discussed. It is instructive to consider how far arrays of Compton-suppressed Ge detectors could be taken. For example, it will be shown that an idealised open-quote perfectclose quotes third-generation array of 1000 detectors has a sensitivity an order of magnitude higher again than that of GAMMASPHERE. Less conventional options for new arrays will also be explored

Generalization and fine mapping of European ancestry-based central adiposity variants in African ancestry populations.

Science.gov (United States)

Yoneyama, S; Yao, J; Guo, X; Fernandez-Rhodes, L; Lim, U; Boston, J; Buzková, P; Carlson, C S; Cheng, I; Cochran, B; Cooper, R; Ehret, G; Fornage, M; Gong, J; Gross, M; Gu, C C; Haessler, J; Haiman, C A; Henderson, B; Hindorff, L A; Houston, D; Irvin, M R; Jackson, R; Kuller, L; Leppert, M; Lewis, C E; Li, R; Le Marchand, L; Matise, T C; Nguyen, K-Dh; Chakravarti, A; Pankow, J S; Pankratz, N; Pooler, L; Ritchie, M D; Bien, S A; Wassel, C L; Chen, Y-D I; Taylor, K D; Allison, M; Rotter, J I; Schreiner, P J; Schumacher, F; Wilkens, L; Boerwinkle, E; Kooperberg, C; Peters, U; Buyske, S; Graff, M; North, K E

2017-02-01

Central adiposity measures such as waist circumference (WC) and waist-to-hip ratio (WHR) are associated with cardiometabolic disorders independently of body mass index (BMI) and are gaining clinically utility. Several studies report genetic variants associated with central adiposity, but most utilize only European ancestry populations. Understanding whether the genetic associations discovered among mainly European descendants are shared with African ancestry populations will help elucidate the biological underpinnings of abdominal fat deposition. To identify the underlying functional genetic determinants of body fat distribution, we conducted an array-wide association meta-analysis among persons of African ancestry across seven studies/consortia participating in the Population Architecture using Genomics and Epidemiology (PAGE) consortium. We used the Metabochip array, designed for fine-mapping cardiovascular-associated loci, to explore novel array-wide associations with WC and WHR among 15 945 African descendants using all and sex-stratified groups. We further interrogated 17 known WHR regions for African ancestry-specific variants. Of the 17 WHR loci, eight single-nucleotide polymorphisms (SNPs) located in four loci were replicated in the sex-combined or sex-stratified meta-analyses. Two of these eight independently associated with WHR after conditioning on the known variant in European descendants (rs12096179 in TBX15-WARS2 and rs2059092 in ADAMTS9). In the fine-mapping assessment, the putative functional region was reduced across all four loci but to varying degrees (average 40% drop in number of putative SNPs and 20% drop in genomic region). Similar to previous studies, the significant SNPs in the female-stratified analysis were stronger than the significant SNPs from the sex-combined analysis. No novel associations were detected in the array-wide analyses. Of 17 previously identified loci, four loci replicated in the African ancestry populations of this

Generalization and fine mapping of European ancestry-based central adiposity variants in African ancestry populations

Science.gov (United States)

Yoneyama, Sachiko; Yao, Jie; Guo, Xiuqing; Fernandez-Rhodes, Lindsay; Lim, Unhee; Boston, Jonathan; Buzková, Petra; Carlson, Christopher S.; Cheng, Iona; Cochran, Barbara; Cooper, Richard; Ehret, Georg; Fornage, Myriam; Gong, Jian; Gross, Myron; Gu, C. Charles; Haessler, Jeff; Haiman, Christopher A.; Henderson, Brian; Hindorff, Lucia A.; Houston, Denise; Irvin, Marguerite R.; Jackson, Rebecca; Kuller, Lew; Leppert, Mark; Lewis, Cora E.; Li, Rongling; Le Marchand, Loic; Matise, Tara C.; Nguyen, Khanh-Dung H.; Chakravarti, Aravinda; Pankow, James S.; Pankratz, Nathan; Pooler, Loreall; Ritchie, Marylyn D.; Bien, Stephanie A.; Wassel, Christina L.; Chen, Yii-Der I.; Taylor, Kent D.; Allison, Matthew; Rotter, Jerome I.; Schreiner, Pamela J.; Schumacher, Fredrick; Wilkens, Lynne; Boerwinkle, Eric; Kooperberg, Charles; Peters, Ulrike; Buyske, Steven; Graff, Mariaelisa; North, Kari E.

2016-01-01

Background/Objectives Central adiposity measures such as waist circumference (WC) and waist-to-hip ratio (WHR) are associated with cardiometabolic disorders independently of BMI and are gaining clinically utility. Several studies report genetic variants associated with central adiposity, but most utilize only European ancestry populations. Understanding whether the genetic associations discovered among mainly European descendants are shared with African ancestry populations will help elucidate the biological underpinnings of abdominal fat deposition. Subjects/Methods To identify the underlying functional genetic determinants of body fat distribution, we conducted an array-wide association meta-analysis among persons of African ancestry across seven studies/consortia participating in the Population Architecture using Genomics and Epidemiology (PAGE) consortium. We used the Metabochip array, designed for fine mapping cardiovascular associated loci, to explore novel array-wide associations with WC and WHR among 15 945 African descendants using all and sex-stratified groups. We further interrogated 17 known WHR regions for African ancestry-specific variants. Results Of the 17 WHR loci, eight SNPs located in four loci were replicated in the sex-combined or sex-stratified meta-analyses. Two of these eight independently associated with WHR after conditioning on the known variant in European descendants (rs12096179 in TBX15-WARS2 and rs2059092 in ADAMTS9). In the fine mapping assessment, the putative functional region was reduced across all four loci but to varying degrees (average 40% drop in number of putative SNPs and 20% drop in genomic region). Similar to previous studies, the significant SNPs in the female stratified analysis were stronger than the significant SNPs from the sex-combined analysis. No novel associations were detected in the array-wide analyses. Conclusions Of 17 previously identified loci, four loci replicated in the African ancestry populations of

Tuning of Clic accelerating structure prototypes at CERN

CERN Document Server

Shi, J; Olyunin, A; Wuensch, W

2010-01-01

An RF measurement system has been set up at CERN for use in the X-band accelerating structure development program of the CLIC study. Using the system, S-parameters are measured and the field distribution is obtained automatically using a bead-pull technique. The corrections for tuning the structure are calculated from an initial measurement and cell-by-cell tuning is applied to obtain the correct phase advance and minimum reflection at the operation frequency. The detailed tuning procedure is presented and explained along with an example of measurement and tuning of CLIC accelerating structure prototypes.

The control of the growth orientations of electrodeposited single-crystal nanowire arrays: a case study for hexagonal CdS

Energy Technology Data Exchange (ETDEWEB)

Sun Hongyu; Li Xiaohong; Chen Yan; Li Wei; Zhang Xiangyi [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, 066004 Qinhuangdao (China); Li Feng; Liu Baoting [College of Physics Science and Technology, Hebei University, 071002 Baoding (China)], E-mail: xyzh66@ysu.edu.cn

2008-06-04

The controllable growth of highly aligned and ordered semiconductor nanowire arrays is crucial for their potential applications in nanodevices. In the present study, both the growth orientation and the microstructure of hexagonal CdS nanowire arrays electrodeposited in a porous alumina template with 40 nm diameter pores have been controlled by simply tuning the deposition current density. An extremely low current density of 0.05 mA cm{sup -2} is favorable for the growth of single-crystal CdS nanowires along the normal direction of the intrinsic low-surface-energy (103) face. This can be understood well by a modified critical dimension model given in the present work.

The control of the growth orientations of electrodeposited single-crystal nanowire arrays: a case study for hexagonal CdS

International Nuclear Information System (INIS)

Sun Hongyu; Li Xiaohong; Chen Yan; Li Wei; Zhang Xiangyi; Li Feng; Liu Baoting

2008-01-01

The controllable growth of highly aligned and ordered semiconductor nanowire arrays is crucial for their potential applications in nanodevices. In the present study, both the growth orientation and the microstructure of hexagonal CdS nanowire arrays electrodeposited in a porous alumina template with 40 nm diameter pores have been controlled by simply tuning the deposition current density. An extremely low current density of 0.05 mA cm -2 is favorable for the growth of single-crystal CdS nanowires along the normal direction of the intrinsic low-surface-energy (103) face. This can be understood well by a modified critical dimension model given in the present work

Spin tune dependence on closed orbit in RHIC

International Nuclear Information System (INIS)

Ptitsyn, V.; Bai, M.; Roser, T.

2010-01-01

Polarized proton beams are accelerated in RHIC to 250 GeV energy with the help of Siberian Snakes. The pair of Siberian Snakes in each RHIC ring holds the design spin tune at 1/2 to avoid polarization loss during acceleration. However, in the presence of closed orbit errors, the actual spin tune can be shifted away from the exact 1/2 value. It leads to a corresponding shift of locations of higher-order ('snake') resonances and limits the available betatron tune space. The largest closed orbit effect on the spin tune comes from the horizontal orbit angle between the two snakes. During RHIC Run in 2009 dedicated measurements with polarized proton beams were taken to verify the dependence of the spin tune on the local orbits at the Snakes. The experimental results are presented along with the comparison with analytical predictions.

Integrated unaligned resonant modulator tuning

Energy Technology Data Exchange (ETDEWEB)

Zortman, William A.; Lentine, Anthony L.

2017-10-03

Methods and systems for tuning a resonant modulator are disclosed. One method includes receiving a carrier signal modulated by the resonant modulator with a stream of data having an approximately equal number of high and low bits, determining an average power of the modulated carrier signal, comparing the average power to a predetermined threshold, and operating a tuning device coupled to the resonant modulator based on the comparison of the average power and the predetermined threshold. One system includes an input structure, a plurality of processing elements, and a digital control element. The input structure is configured to receive, from the resonant modulator, a modulated carrier signal. The plurality of processing elements are configured to determine an average power of the modulated carrier signal. The digital control element is configured to operate a tuning device coupled to the resonant modulator based on the average power of the modulated carrier signal.

Efficient Thermal Tuning Employing Metallic Microheater With Slow Light Effect

DEFF Research Database (Denmark)

Yan, Siqi; Chen, Hao; Gao, Shengqian

2018-01-01

Thermal tuning acts as one of the most fundamental roles in integrated silicon photonics since it can provide flexibility and reconfigurability. Low tuning power and fast tuning speed are long-term pursuing goals in terms of the performance of the thermal tuning. Here we propose and experimentall...

Online control loop tuning in Pickering Nuclear Generating Stations

International Nuclear Information System (INIS)

Yu, K.X.; Harrington, S.

2008-01-01

Most analog controllers in the Pickering B Nuclear Generating Stations adopted PID control scheme. In replacing the analog controllers with digital controllers, the PID control strategies, including the original tuning parameters were retained. The replacement strategy resulted in minimum effort on control loop tuning. In a few cases, however, it was found during commissioning that control loop tuning was required as a result of poor control loop performance, typically due to slow response and controlled process oscillation. Several factors are accounted for the necessities of control loop re-tuning. Our experience in commissioning the digital controllers showed that online control tuning posted some challenges in nuclear power plant. (author)

The concept of mixed organic ligands in metal-organic frameworks: design, tuning and functions.

Science.gov (United States)

Yin, Zheng; Zhou, Yan-Ling; Zeng, Ming-Hua; Kurmoo, Mohamedally

2015-03-28

The research on metal-organic frameworks (MOFs) has been developing at an extraordinary pace in its two decades of existence, as judged by the exponential growth of novel structures and the constant expansion of its applicability and research scope. A major part of the research and its success are due to the vital role of the concept of mixed organic ligands in the design, tuning and functions. This perspective, therefore, reviews the recent advances in MOFs based on this concept, which is generally based on employing a small polydentate ligand (here labelled as "nodal ligand") to form either clusters, rods or layers, which are then connected by a second ditopic linker ligand to form the framework. The structures of the materials can be grouped into the following three categories: layer-spacer (usually known as pillared-layer), rod-spacer, and cluster-spacer based MOFs. Depending on the size and geometry of the spacer ligands, interpenetrations of frameworks are occasionally found. These MOFs show a wide range of properties such as (a) crystal-to-crystal transformations upon solvent modifications, post-synthetic metal exchange or ligand reactions, (b) gas sorption, solvent selectivity and purification, (c) specific catalysis, (d) optical properties including colour change, luminescence, non-linear optic, (e) short- and long range magnetic ordering, metamagnetism and reversible ground-state modifications and (f) drug and iodine carriers with controlled release. In the following, we will highlight the importance of the above concept in the design, tuning, and functions of a selection of existing MOFs having mixed organic ligands and their associated structures and properties. The results obtained so far using this concept look very promising for fine-tuning the pore size and shape for selective adsorption and specificity in catalytic reactions, which appears to be one way to propel the advances in the application and commercialization of MOFs.

Charge neutrality of fine particle (dusty) plasmas and fine particle cloud under gravity

Energy Technology Data Exchange (ETDEWEB)

Totsuji, Hiroo, E-mail: totsuji-09@t.okadai.jp

2017-03-11

The enhancement of the charge neutrality due to the existence of fine particles is shown to occur generally under microgravity and in one-dimensional structures under gravity. As an application of the latter, the size and position of fine particle clouds relative to surrounding plasmas are determined under gravity. - Highlights: • In fine particle (dusty) plasmas, the charge neutrality is much enhanced by the existence of fine particles. • The enhancement of charge neutrality generally occurs under microgravity and gravity. • Structure of fine particle clouds under gravity is determined by applying the enhanced charge neutrality.

Fine Synchronization of the CMS Muon Drift-Tube Local Trigger using Cosmic Rays

CERN Document Server

Chatrchyan, S; Sirunyan, A M; Adam, W; Arnold, B; Bergauer, H; Bergauer, T; Dragicevic, M; Eichberger, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kastner, K; Krammer, M; Liko, D; Magrans de Abril, I; Mikulec, I; Mittermayr, F; Neuherz, B; Oberegger, M; Padrta, M; Pernicka, M; Rohringer, H; Schmid, S; Schöfbeck, R; Schreiner, T; Stark, R; Steininger, H; Strauss, J; Taurok, A; Teischinger, F; Themel, T; Uhl, D; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C E; Chekhovsky, V; Dvornikov, O; Emeliantchik, I; Litomin, A; Makarenko, V; Marfin, I; Mossolov, V; Shumeiko, N; Solin, A; Stefanovitch, R; Suarez Gonzalez, J; Tikhonov, A; Fedorov, A; Karneyeu, A; Korzhik, M; Panov, V; Zuyeuski, R; Kuchinsky, P; Beaumont, W; Benucci, L; Cardaci, M; De Wolf, E A; Delmeire, E; Druzhkin, D; Hashemi, M; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Adler, V; Beauceron, S; Blyweert, S; D'Hondt, J; De Weirdt, S; Devroede, O; Heyninck, J; Kalogeropoulos, A; Maes, J; Maes, M; Mozer, M U; Tavernier, S; Van Doninck, W; Van Mulders, P; Villella, I; Bouhali, O; Chabert, E C; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Elgammal, S; Gay, A P R; Hammad, G H; Marage, P E; Rugovac, S; Vander Velde, C; Vanlaer, P; Wickens, J; Grunewald, M; Klein, B; Marinov, A; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Basegmez, S; Bruno, G; Caudron, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Lemaitre, V; Militaru, O; Ovyn, S; Piotrzkowski, K; Quertenmont, L; Schul, N; Beliy, N; Daubie, E; Alves, G A; Pol, M E; Souza, M H G; Carvalho, W; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Mundim, L; Oguri, V; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Fernandez Perez Tomei, T R; Ferreira Dias, M A; Gregores, E M; Novaes, S F; Abadjiev, K; Anguelov, T; Damgov, J; Darmenov, N; Dimitrov, L; Genchev, V; Iaydjiev, P; Piperov, S; Stoykova, S; Sultanov, G; Trayanov, R; Vankov, I; Dimitrov, A; Dyulendarova, M; Kozhuharov, V; Litov, L; Marinova, E; Mateev, M; Pavlov, B; Petkov, P; Toteva, Z; Chen, G M; Chen, H S; Guan, W; Jiang, C H; Liang, D; Liu, B; Meng, X; Tao, J; Wang, J; Wang, Z; Xue, Z; Zhang, Z; Ban, Y; Cai, J; Ge, Y; Guo, S; Hu, Z; Mao, Y; Qian, S J; Teng, H; Zhu, B; Avila, C; Baquero Ruiz, M; Carrillo Montoya, C A; Gomez, A; Gomez Moreno, B; Ocampo Rios, A A; Osorio Oliveros, A F; Reyes Romero, D; Sanabria, J C; Godinovic, N; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Fereos, R; Galanti, M; Mousa, J; Papadakis, A; Ptochos, F; Razis, P A; Tsiakkouri, D; Zinonos, Z; Hektor, A; Kadastik, M; Kannike, K; Müntel, M; Raidal, M; Rebane, L; Anttila, E; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Klem, J; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Nysten, J; Tuominen, E; Tuominiemi, J; Ungaro, D; Wendland, L; Banzuzi, K; Korpela, A; Tuuva, T; Nedelec, P; Sillou, D; Besancon, M; Chipaux, R; Dejardin, M; Denegri, D; Descamps, J; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Gentit, F X; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Lemaire, M C; Locci, E; Malcles, J; Marionneau, M; Millischer, L; Rander, J; Rosowsky, A; Rousseau, D; Titov, M; Verrecchia, P; Baffioni, S; Bianchini, L; Bluj, M; Busson, P; Charlot, C; Dobrzynski, L; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Paganini, P; Sirois, Y; Thiebaux, C; Zabi, A; Agram, J L; Besson, A; Bloch, D; Bodin, D; Brom, J M; Conte, E; Drouhin, F; Fontaine, J C; Gelé, D; Goerlach, U; Gross, L; Juillot, P; Le Bihan, A C; Patois, Y; Speck, J; Van Hove, P; Baty, C; Bedjidian, M; Blaha, J; Boudoul, G; Brun, H; Chanon, N; Chierici, R; Contardo, D; Depasse, P; Dupasquier, T; El Mamouni, H; Fassi, F; Fay, J; Gascon, S; Ille, B; Kurca, T; Le Grand, T; Lethuillier, M; Lumb, N; Mirabito, L; Perries, S; Vander Donckt, M; Verdier, P; Djaoshvili, N; Roinishvili, N; Roinishvili, V; Amaglobeli, N; Adolphi, R; Anagnostou, G; Brauer, R; Braunschweig, W; Edelhoff, M; Esser, H; Feld, L; Karpinski, W; Khomich, A; Klein, K; Mohr, N; Ostaptchouk, A; Pandoulas, D; Pierschel, G; Raupach, F; Schael, S; Schultz von Dratzig, A; Schwering, G; Sprenger, D; Thomas, M; Weber, M; Wittmer, B; Wlochal, M; Actis, O; Altenhöfer, G; Bender, W; Biallass, P; Erdmann, M; Fetchenhauer, G; Frangenheim, J; Hebbeker, T; Hilgers, G; Hinzmann, A; Hoepfner, K; Hof, C; Kirsch, M; Klimkovich, T; Kreuzer, P; Lanske, D; Merschmeyer, M; Meyer, A; Philipps, B; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Sowa, M; Steggemann, J; Szczesny, H; Teyssier, D; Zeidler, C; Bontenackels, M; Davids, M; Duda, M; Flügge, G; Geenen, H; Giffels, M; Haj Ahmad, W; Hermanns, T; Heydhausen, D; Kalinin, S; Kress, T; Linn, A; Nowack, A; Perchalla, L; Poettgens, M; Pooth, O; Sauerland, P; Stahl, A; Tornier, D; Zoeller, M H; Aldaya Martin, M; Behrens, U; Borras, K; Campbell, A; Castro, E; Dammann, D; Eckerlin, G; Flossdorf, A; Flucke, G; Geiser, A; Hatton, D; Hauk, J; Jung, H; Kasemann, M; Katkov, I; Kleinwort, C; Kluge, H; Knutsson, A; Kuznetsova, E; Lange, W; Lohmann, W; Mankel, R; Marienfeld, M; Meyer, A B; Miglioranzi, S; Mnich, J; Ohlerich, M; Olzem, J; Parenti, A; Rosemann, C; Schmidt, R; Schoerner-Sadenius, T; Volyanskyy, D; Wissing, C; Zeuner, W D; Autermann, C; Bechtel, F; Draeger, J; Eckstein, D; Gebbert, U; Kaschube, K; Kaussen, G; Klanner, R; Mura, B; Naumann-Emme, S; Nowak, F; Pein, U; Sander, C; Schleper, P; Schum, T; Stadie, H; Steinbrück, G; Thomsen, J; Wolf, R; Bauer, J; Blüm, P; Buege, V; Cakir, A; Chwalek, T; De Boer, W; Dierlamm, A; Dirkes, G; Feindt, M; Felzmann, U; Frey, M; Furgeri, A; Gruschke, J; Hackstein, C; Hartmann, F; Heier, S; Heinrich, M; Held, H; Hirschbuehl, D; Hoffmann, K H; Honc, S; Jung, C; Kuhr, T; Liamsuwan, T; Martschei, D; Mueller, S; Müller, Th; Neuland, M B; Niegel, M; Oberst, O; Oehler, A; Ott, J; Peiffer, T; Piparo, D; Quast, G; Rabbertz, K; Ratnikov, F; Ratnikova, N; Renz, M; Saout, C; Sartisohn, G; Scheurer, A; Schieferdecker, P; Schilling, F P; Schott, G; Simonis, H J; Stober, F M; Sturm, P; Troendle, D; Trunov, A; Wagner, W; Wagner-Kuhr, J; Zeise, M; Zhukov, V; Ziebarth, E B; Daskalakis, G; Geralis, T; Karafasoulis, K; Kyriakis, A; Loukas, D; Markou, A; Markou, C; Mavrommatis, C; Petrakou, E; Zachariadou, A; Gouskos, L; Katsas, P; Panagiotou, A; Evangelou, I; Kokkas, P; Manthos, N; Papadopoulos, I; Patras, V; Triantis, F A; Bencze, G; Boldizsar, L; Debreczeni, G; Hajdu, C; Hernath, S; Hidas, P; Horvath, D; Krajczar, K; Laszlo, A; Patay, G; Sikler, F; Toth, N; Vesztergombi, G; Beni, N; Christian, G; Imrek, J; Molnar, J; Novak, D; Palinkas, J; Szekely, G; Szillasi, Z; Tokesi, K; Veszpremi, V; Kapusi, A; Marian, G; Raics, P; Szabo, Z; Trocsanyi, Z L; Ujvari, B; Zilizi, G; Bansal, S; Bawa, H S; Beri, S B; Bhatnagar, V; Jindal, M; Kaur, M; Kaur, R; Kohli, J M; Mehta, M Z; Nishu, N; Saini, L K; Sharma, A; Singh, A; Singh, J B; Singh, S P; Ahuja, S; Arora, S; Bhattacharya, S; Chauhan, S; Choudhary, B C; Gupta, P; Jain, S; Jha, M; Kumar, A; Ranjan, K; Shivpuri, R K; Srivastava, A K; Choudhury, R K; Dutta, D; Kailas, S; Kataria, S K; Mohanty, A K; Pant, L M; Shukla, P; Topkar, A; Aziz, T; Guchait, M; Gurtu, A; Maity, M; Majumder, D; Majumder, G; Mazumdar, K; Nayak, A; Saha, A; Sudhakar, K; Banerjee, S; Dugad, S; Mondal, N K; Arfaei, H; Bakhshiansohi, H; Fahim, A; Jafari, A; Mohammadi Najafabadi, M; Moshaii, A; Paktinat Mehdiabadi, S; Rouhani, S; Safarzadeh, B; Zeinali, M; Felcini, M; Abbrescia, M; Barbone, L; Chiumarulo, F; Clemente, A; Colaleo, A; Creanza, D; Cuscela, G; De Filippis, N; De Palma, M; De Robertis, G; Donvito, G; Fedele, F; Fiore, L; Franco, M; Iaselli, G; Lacalamita, N; Loddo, F; Lusito, L; Maggi, G; Maggi, M; Manna, N; Marangelli, B; My, S; Natali, S; Nuzzo, S; Papagni, G; Piccolomo, S; Pierro, G A; Pinto, C; Pompili, A; Pugliese, G; Rajan, R; Ranieri, A; Romano, F; Roselli, G; Selvaggi, G; Shinde, Y; Silvestris, L; Tupputi, S; Zito, G; Abbiendi, G; Bacchi, W; Benvenuti, A C; Boldini, M; Bonacorsi, D; Braibant-Giacomelli, S; Cafaro, V D; Caiazza, S S; Capiluppi, P; Castro, A; Cavallo, F R; Codispoti, G; Cuffiani, M; D'Antone, I; Dallavalle, G M; Fabbri, F; Fanfani, A; Fasanella, D; Giacomelli, P; Giordano, V; Giunta, M; Grandi, C; Guerzoni, M; Marcellini, S; Masetti, G; Montanari, A; Navarria, F L; Odorici, F; Pellegrini, G; Perrotta, A; Rossi, A M; Rovelli, T; Siroli, G; Torromeo, G; Travaglini, R; Albergo, S; Costa, S; Potenza, R; Tricomi, A; Tuve, C; Barbagli, G; Broccolo, G; Ciulli, V; Civinini, C; D'Alessandro, R; Focardi, E; Frosali, S; Gallo, E; Genta, C; Landi, G; Lenzi, P; Meschini, M; Paoletti, S; Sguazzoni, G; Tropiano, A; Benussi, L; Bertani, M; Bianco, S; Colafranceschi, S; Colonna, D; Fabbri, F; Giardoni, M; Passamonti, L; Piccolo, D; Pierluigi, D; Ponzio, B; Russo, A; Fabbricatore, P; Musenich, R; Benaglia, A; Calloni, M; Cerati, G B; D'Angelo, P; De Guio, F; Farina, F M; Ghezzi, A; Govoni, P; Malberti, M; Malvezzi, S; Martelli, A; Menasce, D; Miccio, V; Moroni, L; Negri, P; Paganoni, M; Pedrini, D; Pullia, A; Ragazzi, S; Redaelli, N; Sala, S; Salerno, R; Tabarelli de Fatis, T; Tancini, V; Taroni, S; Buontempo, S; Cavallo, N; Cimmino, A; De Gruttola, M; Fabozzi, F; Iorio, A O M; Lista, L; Lomidze, D; Noli, P; Paolucci, P; Sciacca, C; Azzi, P; Bacchetta, N; Barcellan, L; Bellan, P; Bellato, M; Benettoni, M; Biasotto, M; Bisello, D; Borsato, E; Branca, A; Carlin, R; Castellani, L; Checchia, P; Conti, E; Dal Corso, F; De Mattia, M; Dorigo, T; Dosselli, U; Fanzago, F; Gasparini, F; Gasparini, U; Giubilato, P; Gonella, F; Gresele, A; Gulmini, M; Kaminskiy, A; Lacaprara, S; Lazzizzera, I; Margoni, M; Maron, G; Mattiazzo, S; Mazzucato, M; Meneghelli, M; Meneguzzo, A T; Michelotto, M; Montecassiano, F; Nespolo, M; Passaseo, M; Pegoraro, M; Perrozzi, L; Pozzobon, N; Ronchese, P; Simonetto, F; Toniolo, N; Torassa, E; Tosi, M; Triossi, A; Vanini, S; Ventura, S; Zotto, P; Zumerle, G; Baesso, P; Berzano, U; Bricola, S; Necchi, M M; Pagano, D; Ratti, S P; Riccardi, C; Torre, P; Vicini, A; Vitulo, P; Viviani, C; Aisa, D; Aisa, S; Babucci, E; Biasini, M; Bilei, G M; Caponeri, B; Checcucci, B; Dinu, N; Fanò, L; Farnesini, L; Lariccia, P; Lucaroni, A; Mantovani, G; Nappi, A; Piluso, A; Postolache, V; Santocchia, A; Servoli, L; Tonoiu, D; Vedaee, A; Volpe, R; Azzurri, P; Bagliesi, G; Bernardini, J; Berretta, L; Boccali, T; Bocci, A; Borrello, L; Bosi, F; Calzolari, F; Castaldi, R; Dell'Orso, R; Fiori, F; Foà, L; Gennai, S; Giassi, A; Kraan, A; Ligabue, F; Lomtadze, T; Mariani, F; Martini, L; Massa, M; Messineo, A; Moggi, A; Palla, F; Palmonari, F; Petragnani, G; Petrucciani, G; Raffaelli, F; Sarkar, S; Segneri, G; Serban, A T; Spagnolo, P; Tenchini, R; Tolaini, S; Tonelli, G; Venturi, A; Verdini, P G; Baccaro, S; Barone, L; Bartoloni, A; Cavallari, F; Dafinei, I; Del Re, D; Di Marco, E; Diemoz, M; Franci, D; Longo, E; Organtini, G; Palma, A; Pandolfi, F; Paramatti, R; Pellegrino, F; Rahatlou, S; Rovelli, C; Alampi, G; Amapane, N; Arcidiacono, R; Argiro, S; Arneodo, M; Biino, C; Borgia, M A; Botta, C; Cartiglia, N; Castello, R; Cerminara, G; Costa, M; Dattola, D; Dellacasa, G; Demaria, N; Dughera, G; Dumitrache, F; Graziano, A; Mariotti, C; Marone, M; Maselli, S; Migliore, E; Mila, G; Monaco, V; Musich, M; Nervo, M; Obertino, M M; Oggero, S; Panero, R; Pastrone, N; Pelliccioni, M; Romero, A; Ruspa, M; Sacchi, R; Solano, A; Staiano, A; Trapani, P P; Trocino, D; Vilela Pereira, A; Visca, L; Zampieri, A; Ambroglini, F; Belforte, S; Cossutti, F; Della Ricca, G; Gobbo, B; Penzo, A; Chang, S; Chung, J; Kim, D H; Kim, G N; Kong, D J; Park, H; Son, D C; Bahk, S Y; Song, S; Jung, S Y; Hong, B; Kim, H; Kim, J H; Lee, K S; Moon, D H; Park, S K; Rhee, H B; Sim, K S; Kim, J; Choi, M; Hahn, G; Park, I C; Choi, S; Choi, Y; Goh, J; Jeong, H; Kim, T J; Lee, J; Lee, S; Janulis, M; Martisiute, D; Petrov, P; Sabonis, T; Castilla Valdez, H; Sánchez Hernández, A; Carrillo Moreno, S; Morelos Pineda, A; Allfrey, P; Gray, R N C; Krofcheck, D; Bernardino Rodrigues, N; Butler, P H; Signal, T; Williams, J C; Ahmad, M; Ahmed, I; Ahmed, W; Asghar, M I; Awan, M I M; Hoorani, H R; Hussain, I; Khan, W A; Khurshid, T; Muhammad, S; Qazi, S; Shahzad, H; Cwiok, M; Dabrowski, R; Dominik, W; Doroba, K; Konecki, M; Krolikowski, J; Pozniak, K; Romaniuk, Ryszard; Zabolotny, W; Zych, P; Frueboes, T; Gokieli, R; Goscilo, L; Górski, M; Kazana, M; Nawrocki, K; Szleper, M; Wrochna, G; Zalewski, P; Almeida, N; Antunes Pedro, L; Bargassa, P; David, A; Faccioli, P; Ferreira Parracho, P G; Freitas Ferreira, M; Gallinaro, M; Guerra Jordao, M; Martins, P; Mini, G; Musella, P; Pela, J; Raposo, L; Ribeiro, P Q; Sampaio, S; Seixas, J; Silva, J; Silva, P; Soares, D; Sousa, M; Varela, J; Wöhri, H K; Altsybeev, I; Belotelov, I; Bunin, P; Ershov, Y; Filozova, I; Finger, M; Finger, M., Jr.; Golunov, A; Golutvin, I; Gorbounov, N; Kalagin, V; Kamenev, A; Karjavin, V; Konoplyanikov, V; Korenkov, V; Kozlov, G; Kurenkov, A; Lanev, A; Makankin, A; Mitsyn, V V; Moisenz, P; Nikonov, E; Oleynik, D; Palichik, V; Perelygin, V; Petrosyan, A; Semenov, R; Shmatov, S; Smirnov, V; Smolin, D; Tikhonenko, E; Vasil'ev, S; Vishnevskiy, A; Volodko, A; Zarubin, A; Zhiltsov, V; Bondar, N; Chtchipounov, L; Denisov, A; Gavrikov, Y; Gavrilov, G; Golovtsov, V; Ivanov, Y; Kim, V; Kozlov, V; Levchenko, P; Obrant, G; Orishchin, E; Petrunin, A; Shcheglov, Y; Shchetkovskiy, A; Sknar, V; Smirnov, I; Sulimov, V; Tarakanov, V; Uvarov, L; Vavilov, S; Velichko, G; Volkov, S; Vorobyev, A; Andreev, Yu; Anisimov, A; Antipov, P; Dermenev, A; Gninenko, S; Golubev, N; Kirsanov, M; Krasnikov, N; Matveev, V; Pashenkov, A; Postoev, V E; Solovey, A; Toropin, A; Troitsky, S; Baud, A; Epshteyn, V; Gavrilov, V; Ilina, N; Kaftanov, V; Kolosov, V; Kossov, M; Krokhotin, A; Kuleshov, S; Oulianov, A; Safronov, G; Semenov, S; Shreyber, I; Stolin, V; Vlasov, E; Zhokin, A; Boos, E; Dubinin, M; Dudko, L; Ershov, A; Gribushin, A; Klyukhin, V; Kodolova, O; Lokhtin, I; Petrushanko, S; Sarycheva, L; Savrin, V; Snigirev, A; Vardanyan, I; Dremin, I; Kirakosyan, M; Konovalova, N; Rusakov, S V; Vinogradov, A; Akimenko, S; Artamonov, A; Azhgirey, I; Bitioukov, S; Burtovoy, V; Grishin, V; Kachanov, V; Konstantinov, D; Krychkine, V; Levine, A; Lobov, I; Lukanin, V; Mel'nik, Y; Petrov, V; Ryutin, R; Slabospitsky, S; Sobol, A; Sytine, A; Tourtchanovitch, L; Troshin, S; Tyurin, N; Uzunian, A; Volkov, A; Adzic, P; Djordjevic, M; Jovanovic, D; Krpic, D; Maletic, D; Puzovic, J; Smiljkovic, N; Aguilar-Benitez, M; Alberdi, J; Alcaraz Maestre, J; Arce, P; Barcala, J M; Battilana, C; Burgos Lazaro, C; Caballero Bejar, J; Calvo, E; Cardenas Montes, M; Cepeda, M; Cerrada, M; Chamizo Llatas, M; Clemente, F; Colino, N; Daniel, M; De La Cruz, B; Delgado Peris, A; Diez Pardos, C; Fernandez Bedoya, C; Fernández Ramos, J P; Ferrando, A; Flix, J; Fouz, M C; Garcia-Abia, P; Garcia-Bonilla, A C; Gonzalez Lopez, O; Goy Lopez, S; Hernandez, J M; Josa, M I; Marin, J; Merino, G; Molina, J; Molinero, A; Navarrete, J J; Oller, J C; Puerta Pelayo, J; Romero, L; Santaolalla, J; Villanueva Munoz, C; Willmott, C; Yuste, C; Albajar, C; Blanco Otano, M; de Trocóniz, J F; Garcia Raboso, A; Lopez Berengueres, J O; Cuevas, J; Fernandez Menendez, J; Gonzalez Caballero, I; Lloret Iglesias, L; Naves Sordo, H; Vizan Garcia, J M; Cabrillo, I J; Calderon, A; Chuang, S H; Diaz Merino, I; Diez Gonzalez, C; Duarte Campderros, J; Fernandez, M; Gomez, G; Gonzalez Sanchez, J; Gonzalez Suarez, R; Jorda, C; Lobelle Pardo, P; Lopez Virto, A; Marco, J; Marco, R; Martinez Rivero, C; Martinez Ruiz del Arbol, P; Matorras, F; Rodrigo, T; Ruiz Jimeno, A; Scodellaro, L; Sobron Sanudo, M; Vila, I; Vilar Cortabitarte, R; Abbaneo, D; Albert, E; Alidra, M; Ashby, S; Auffray, E; Baechler, J; Baillon, P; Ball, A H; Bally, S L; Barney, D; Beaudette, F; Bellan, R; Benedetti, D; Benelli, G; Bernet, C; Bloch, P; Bolognesi, S; Bona, M; Bos, J; Bourgeois, N; Bourrel, T; Breuker, H; Bunkowski, K; Campi, D; Camporesi, T; Cano, E; Cattai, A; Chatelain, J P; Chauvey, M; Christiansen, T; Coarasa Perez, J A; Conde Garcia, A; Covarelli, R; Curé, B; De Roeck, A; Delachenal, V; Deyrail, D; Di Vincenzo, S; Dos Santos, S; Dupont, T; Edera, L M; Elliott-Peisert, A; Eppard, M; Favre, M; Frank, N; Funk, W; Gaddi, A; Gastal, M; Gateau, M; Gerwig, H; Gigi, D; Gill, K; Giordano, D; Girod, J P; Glege, F; Gomez-Reino Garrido, R; Goudard, R; Gowdy, S; Guida, R; Guiducci, L; Gutleber, J; Hansen, M; Hartl, C; Harvey, J; Hegner, B; Hoffmann, H F; Holzner, A; Honma, A; Huhtinen, M; Innocente, V; Janot, P; Le Godec, G; Lecoq, P; Leonidopoulos, C; Loos, R; Lourenço, C; Lyonnet, A; Macpherson, A; Magini, N; Maillefaud, J D; Maire, G; Mäki, T; Malgeri, L; Mannelli, M; Masetti, L; Meijers, F; Meridiani, P; Mersi, S; Meschi, E; Meynet Cordonnier, A; Moser, R; Mulders, M; Mulon, J; Noy, M; Oh, A; Olesen, G; Onnela, A; Orimoto, T; Orsini, L; Perez, E; Perinic, G; Pernot, J F; Petagna, P; Petiot, P; Petrilli, A; Pfeiffer, A; Pierini, M; Pimiä, M; Pintus, R; Pirollet, B; Postema, H; Racz, A; Ravat, S; Rew, S B; Rodrigues Antunes, J; Rolandi, G; Rovere, M; Ryjov, V; Sakulin, H; Samyn, D; Sauce, H; Schäfer, C; Schlatter, W D; Schröder, M; Schwick, C; Sciaba, A; Segoni, I; Sharma, A; Siegrist, N; Siegrist, P; Sinanis, N; Sobrier, T; Sphicas, P; Spiga, D; Spiropulu, M; Stöckli, F; Traczyk, P; Tropea, P; Troska, J; Tsirou, A; Veillet, L; Veres, G I; Voutilainen, M; Wertelaers, P; Zanetti, M; Bertl, W; Deiters, K; Erdmann, W; Gabathuler, K; Horisberger, R; Ingram, Q; Kaestli, H C; König, S; Kotlinski, D; Langenegger, U; Meier, F; Renker, D; Rohe, T; Sibille, J; Starodumov, A; Betev, B; Caminada, L; Chen, Z; Cittolin, S; Da Silva Di Calafiori, D R; Dambach, S; Dissertori, G; Dittmar, M; Eggel, C; Eugster, J; Faber, G; Freudenreich, K; Grab, C; Hervé, A; Hintz, W; Lecomte, P; Luckey, P D; Lustermann, W; Marchica, C; Milenovic, P; Moortgat, F; Nardulli, A; Nessi-Tedaldi, F; Pape, L; Pauss, F; Punz, T; Rizzi, A; Ronga, F J; Sala, L; Sanchez, A K; Sawley, M C; Sordini, V; Stieger, B; Tauscher, L; Thea, A; Theofilatos, K; Treille, D; Trüb, P; Weber, M; Wehrli, L; Weng, J; Zelepoukine, S; Amsler, C; Chiochia, V; De Visscher, S; Regenfus, C; Robmann, P; Rommerskirchen, T; Schmidt, A; Tsirigkas, D; Wilke, L; Chang, Y H; Chen, E A; Chen, W T; Go, A; Kuo, C M; Li, S W; Lin, W; Bartalini, P; Chang, P; Chao, Y; Chen, K F; Hou, W S; Hsiung, Y; Lei, Y J; Lin, S W; Lu, R S; Schümann, J; Shiu, J G; Tzeng, Y M; Ueno, K; Velikzhanin, Y; Wang, C C; Wang, M; Adiguzel, A; Ayhan, A; Azman Gokce, A; Bakirci, M N; Cerci, S; Dumanoglu, I; Eskut, E; Girgis, S; Gurpinar, E; Hos, I; Karaman, T; Kayis Topaksu, A; Kurt, P; Önengüt, G; Önengüt Gökbulut, G; Ozdemir, K; Ozturk, S; Polatöz, A; Sogut, K; Tali, B; Topakli, H; Uzun, D; Vergili, L N; Vergili, M; Akin, I V; Aliev, T; Bilmis, S; Deniz, M; Gamsizkan, H; Guler, A M; Öcalan, K; Serin, M; Sever, R; Surat, U E; Zeyrek, M; Deliomeroglu, M; Demir, D; Gülmez, E; Halu, A; Isildak, B; Kaya, M; Kaya, O; Ozkorucuklu, S; Sonmez, N; Levchuk, L; Lukyanenko, S; Soroka, D; Zub, S; Bostock, F; Brooke, J J; Cheng, T L; Cussans, D; Frazier, R; Goldstein, J; Grant, N; Hansen, M; Heath, G P; Heath, H F; Hill, C; Huckvale, B; Jackson, J; Mackay, C K; Metson, S; Newbold, D M; Nirunpong, K; Smith, V J; Velthuis, J; Walton, R; Bell, K W; Brew, C; Brown, R M; Camanzi, B; Cockerill, D J A; Coughlan, J A; Geddes, N I; Harder, K; Harper, S; Kennedy, B W; Murray, P; Shepherd-Themistocleous, C H; Tomalin, I R; Williams, J H; Womersley, W J; Worm, S D; Bainbridge, R; Ball, G; Ballin, J; Beuselinck, R; Buchmuller, O; Colling, D; Cripps, N; Davies, G; Della Negra, M; Foudas, C; Fulcher, J; Futyan, D; Hall, G; Hays, J; Iles, G; Karapostoli, G; MacEvoy, B C; Magnan, A M; Marrouche, J; Nash, J; Nikitenko, A; Papageorgiou, A; Pesaresi, M; Petridis, K; Pioppi, M; Raymond, D M; Rompotis, N; Rose, A; Ryan, M J; Seez, C; Sharp, P; Sidiropoulos, G; Stettler, M; Stoye, M; Takahashi, M; Tapper, A; Timlin, C; Tourneur, S; Vazquez Acosta, M; Virdee, T; Wakefield, S; Wardrope, D; Whyntie, T; Wingham, M; Cole, J E; Goitom, I; Hobson, P R; Khan, A; Kyberd, P; Leslie, D; Munro, C; Reid, I D; Siamitros, C; Taylor, R; Teodorescu, L; Yaselli, I; Bose, T; Carleton, M; Hazen, E; Heering, A H; Heister, A; John, J St; Lawson, P; Lazic, D; Osborne, D; Rohlf, J; Sulak, L; Wu, S; Andrea, J; Avetisyan, A; Bhattacharya, S; Chou, J P; Cutts, D; Esen, S; Kukartsev, G; Landsberg, G; Narain, M; Nguyen, D; Speer, T; Tsang, K V; Breedon, R; Calderon De La Barca Sanchez, M; Case, M; Cebra, D; Chertok, M; Conway, J; Cox, P T; Dolen, J; Erbacher, R; Friis, E; Ko, W; Kopecky, A; Lander, R; Lister, A; Liu, H; Maruyama, S; Miceli, T; Nikolic, M; Pellett, D; Robles, J; Searle, M; Smith, J; Squires, M; Stilley, J; Tripathi, M; Vasquez Sierra, R; Veelken, C; Andreev, V; Arisaka, K; Cline, D; Cousins, R; Erhan, S; Hauser, J; Ignatenko, M; Jarvis, C; Mumford, J; Plager, C; Rakness, G; Schlein, P; Tucker, J; Valuev, V; Wallny, R; Yang, X; Babb, J; Bose, M; Chandra, A; Clare, R; Ellison, J A; Gary, J W; Hanson, G; Jeng, G Y; Kao, S C; Liu, F; Liu, H; Luthra, A; Nguyen, H; Pasztor, G; Satpathy, A; Shen, B C; Stringer, R; Sturdy, J; Sytnik, V; Wilken, R; Wimpenny, S; Branson, J G; Dusinberre, E; Evans, D; Golf, F; Kelley, R; Lebourgeois, M; Letts, J; Lipeles, E; Mangano, B; Muelmenstaedt, J; Norman, M; Padhi, S; Petrucci, A; Pi, H; Pieri, M; Ranieri, R; Sani, M; Sharma, V; Simon, S; Würthwein, F; Yagil, A; Campagnari, C; D'Alfonso, M; Danielson, T; Garberson, J; Incandela, J; Justus, C; Kalavase, P; Koay, S A; Kovalskyi, D; Krutelyov, V; Lamb, J; Lowette, S; Pavlunin, V; Rebassoo, F; Ribnik, J; Richman, J; Rossin, R; Stuart, D; To, W; Vlimant, J R; Witherell, M; Apresyan, A; Bornheim, A; Bunn, J; Chiorboli, M; Gataullin, M; Kcira, D; Litvine, V; Ma, Y; Newman, H B; Rogan, C; Timciuc, V; Veverka, J; Wilkinson, R; Yang, Y; Zhang, L; Zhu, K; Zhu, R Y; Akgun, B; Carroll, R; Ferguson, T; Jang, D W; Jun, S Y; Paulini, M; Russ, J; Terentyev, N; Vogel, H; Vorobiev, I; Cumalat, J P; Dinardo, M E; Drell, B R; Ford, W T; Heyburn, B; Luiggi Lopez, E; Nauenberg, U; Stenson, K; Ulmer, K; Wagner, S R; Zang, S L; Agostino, L; Alexander, J; Blekman, F; Cassel, D; Chatterjee, A; Das, S; Gibbons, L K; Heltsley, B; Hopkins, W; Khukhunaishvili, A; Kreis, B; Kuznetsov, V; Patterson, J R; Puigh, D; Ryd, A; Shi, X; Stroiney, S; Sun, W; Teo, W D; Thom, J; Vaughan, J; Weng, Y; Wittich, P; Beetz, C P; Cirino, G; Sanzeni, C; Winn, D; Abdullin, S; Afaq, M A; Albrow, M; Ananthan, B; Apollinari, G; Atac, M; Badgett, W; Bagby, L; Bakken, J A; Baldin, B; Banerjee, S; Banicz, K; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Biery, K; Binkley, M; Bloch, I; Borcherding, F; Brett, A M; Burkett, K; Butler, J N; Chetluru, V; Cheung, H W K; Chlebana, F; Churin, I; Cihangir, S; Crawford, M; Dagenhart, W; Demarteau, M; Derylo, G; Dykstra, D; Eartly, D P; Elias, J E; Elvira, V D; Evans, D; Feng, L; Fischler, M; Fisk, I; Foulkes, S; Freeman, J; Gartung, P; Gottschalk, E; Grassi, T; Green, D; Guo, Y; Gutsche, O; Hahn, A; Hanlon, J; Harris, R M; Holzman, B; Howell, J; Hufnagel, D; James, E; Jensen, H; Johnson, M; Jones, C D; Joshi, U; Juska, E; Kaiser, J; Klima, B; Kossiakov, S; Kousouris, K; Kwan, S; Lei, C M; Limon, P; Lopez Perez, J A; Los, S; Lueking, L; Lukhanin, G; Lusin, S; Lykken, J; Maeshima, K; Marraffino, J M; Mason, D; McBride, P; Miao, T; Mishra, K; Moccia, S; Mommsen, R; Mrenna, S; Muhammad, A S; Newman-Holmes, C; Noeding, C; O'Dell, V; Prokofyev, O; Rivera, R; Rivetta, C H; Ronzhin, A; Rossman, P; Ryu, S; Sekhri, V; Sexton-Kennedy, E; Sfiligoi, I; Sharma, S; Shaw, T M; Shpakov, D; Skup, E; Smith, R P; Soha, A; Spalding, W J; Spiegel, L; Suzuki, I; Tan, P; Tanenbaum, W; Tkaczyk, S; Trentadue, R; Uplegger, L; Vaandering, E W; Vidal, R; Whitmore, J; Wicklund, E; Wu, W; Yarba, J; Yumiceva, F; Yun, J C; Acosta, D; Avery, P; Barashko, V; Bourilkov, D; Chen, M; Di Giovanni, G P; Dobur, D; Drozdetskiy, A; Field, R D; Fu, Y; Furic, I K; Gartner, J; Holmes, D; Kim, B; Klimenko, S; Konigsberg, J; Korytov, A; Kotov, K; Kropivnitskaya, A; Kypreos, T; Madorsky, A; Matchev, K; Mitselmakher, G; Pakhotin, Y; Piedra Gomez, J; Prescott, C; Rapsevicius, V; Remington, R; Schmitt, M; Scurlock, B; Wang, D; Yelton, J; Ceron, C; Gaultney, V; Kramer, L; Lebolo, L M; Linn, S; Markowitz, P; Martinez, G; Rodriguez, J L; Adams, T; Askew, A; Baer, H; Bertoldi, M; Chen, J; Dharmaratna, W G D; Gleyzer, S V; Haas, J; Hagopian, S; Hagopian, V; Jenkins, M; Johnson, K F; Prettner, E; Prosper, H; Sekmen, S; Baarmand, M M; Guragain, S; Hohlmann, M; Kalakhety, H; Mermerkaya, H; Ralich, R; Vodopiyanov, I; Abelev, B; Adams, M R; Anghel, I M; Apanasevich, L; Bazterra, V E; Betts, R R; Callner, J; Castro, M A; Cavanaugh, R; Dragoiu, C; Garcia-Solis, E J; Gerber, C E; Hofman, D J; Khalatian, S; Mironov, C; Shabalina, E; Smoron, A; Varelas, N; Akgun, U; Albayrak, E A; Ayan, A S; Bilki, B; Briggs, R; Cankocak, K; Chung, K; Clarida, W; Debbins, P; Duru, F; Ingram, F D; Lae, C K; McCliment, E; Merlo, J P; Mestvirishvili, A; Miller, M J; Moeller, A; Nachtman, J; Newsom, C R; Norbeck, E; Olson, J; Onel, Y; Ozok, F; Parsons, J; Schmidt, I; Sen, S; Wetzel, J; Yetkin, T; Yi, K; Barnett, B A; Blumenfeld, B; Bonato, A; Chien, C Y; Fehling, D; Giurgiu, G; Gritsan, A V; Guo, Z J; Maksimovic, P; Rappoccio, S; Swartz, M; Tran, N V; Zhang, Y; Baringer, P; Bean, A; Grachov, O; Murray, M; Radicci, V; Sanders, S; Wood, J S; Zhukova, V; Bandurin, D; Bolton, T; Kaadze, K; Liu, A; Maravin, Y; Onoprienko, D; Svintradze, I; Wan, Z; Gronberg, J; Hollar, J; Lange, D; Wright, D; Baden, D; Bard, R; Boutemeur, M; Eno, S C; Ferencek, D; Hadley, N J; Kellogg, R G; Kirn, M; Kunori, S; Rossato, K; Rumerio, P; Santanastasio, F; Skuja, A; Temple, J; Tonjes, M B; Tonwar, S C; Toole, T; Twedt, E; Alver, B; Bauer, G; Bendavid, J; Busza, W; Butz, E; Cali, I A; Chan, M; D'Enterria, D; Everaerts, P; Gomez Ceballos, G; Hahn, K A; Harris, P; Jaditz, S; Kim, Y; Klute, M; Lee, Y J; Li, W; Loizides, C; Ma, T; Miller, M; Nahn, S; Paus, C; Roland, C; Roland, G; Rudolph, M; Stephans, G; Sumorok, K; Sung, K; Vaurynovich, S; Wenger, E A; Wyslouch, B; Xie, S; Yilmaz, Y; Yoon, A S; Bailleux, D; Cooper, S I; Cushman, P; Dahmes, B; De Benedetti, A; Dolgopolov, A; Dudero, P R; Egeland, R; Franzoni, G; Haupt, J; Inyakin, A; Klapoetke, K; Kubota, Y; Mans, J; Mirman, N; Petyt, D; Rekovic, V; Rusack, R; Schroeder, M; Singovsky, A; Zhang, J; Cremaldi, L M; Godang, R; Kroeger, R; Perera, L; Rahmat, R; Sanders, D A; Sonnek, P; Summers, D; Bloom, K; Bockelman, B; Bose, S; Butt, J; Claes, D R; Dominguez, A; Eads, M; Keller, J; Kelly, T; Kravchenko, I; Lazo-Flores, J; Lundstedt, C; Malbouisson, H; Malik, S; Snow, G R; Baur, U; Iashvili, I; Kharchilava, A; Kumar, A; Smith, K; Strang, M; Alverson, G; Barberis, E; Boeriu, O; Eulisse, G; Govi, G; McCauley, T; Musienko, Y; Muzaffar, S; Osborne, I; Paul, T; Reucroft, S; Swain, J; Taylor, L; Tuura, L; Anastassov, A; Gobbi, B; Kubik, A; Ofierzynski, R A; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Hildreth, M; Jessop, C; Karmgard, D J; Kolberg, T; Lannon, K; Lynch, S; Marinelli, N; Morse, D M; Ruchti, R; Slaunwhite, J; Warchol, J; Wayne, M; Bylsma, B; Durkin, L S; Gilmore, J; Gu, J; Killewald, P; Ling, T Y; Williams, G; Adam, N; Berry, E; Elmer, P; Garmash, A; Gerbaudo, D; Halyo, V; Hunt, A; Jones, J; Laird, E; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Stickland, D; Tully, C; Werner, J S; Wildish, T; Xie, Z; Zuranski, A; Acosta, J G; Bonnett Del Alamo, M; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Ramirez Vargas, J E; Santacruz, N; Zatzerklyany, A; Alagoz, E; Antillon, E; Barnes, V E; Bolla, G; Bortoletto, D; Everett, A; Garfinkel, A F; Gecse, Z; Gutay, L; Ippolito, N; Jones, M; Koybasi, O; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Sedov, A; Shipsey, I; Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

2010-01-01

The CMS experiment uses self-triggering arrays of drift tubes in the barrel muon trigger to perform the identification of the correct bunch crossing. The identification is unique only if the trigger chain is correctly synchronized. In this paper, the synchronization performed during an extended cosmic ray run is described and the results are reported. The random arrival time of cosmic ray muons allowed several synchronization aspects to be studied and a simple method for the fine synchronization of the Drift Tube Local Trigger at LHC to be developed.

Exploiting Molecular Weight Distribution Shape to Tune Domain Spacing in Block Copolymer Thin Films.

Science.gov (United States)

Gentekos, Dillon T; Jia, Junteng; Tirado, Erika S; Barteau, Katherine P; Smilgies, Detlef-M; DiStasio, Robert A; Fors, Brett P

2018-04-04

We report a method for tuning the domain spacing ( D sp ) of self-assembled block copolymer thin films of poly(styrene- block-methyl methacrylate) (PS- b-PMMA) over a large range of lamellar periods. By modifying the molecular weight distribution (MWD) shape (including both the breadth and skew) of the PS block via temporal control of polymer chain initiation in anionic polymerization, we observe increases of up to 41% in D sp for polymers with the same overall molecular weight ( M n ≈ 125 kg mol -1 ) without significantly changing the overall morphology or chemical composition of the final material. In conjunction with our experimental efforts, we have utilized concepts from population statistics and least-squares analysis to develop a model for predicting D sp based on the first three moments of the MWDs. This statistical model reproduces experimental D sp values with high fidelity (with mean absolute errors of 1.2 nm or 1.8%) and provides novel physical insight into the individual and collective roles played by the MWD moments in determining this property of interest. This work demonstrates that both MWD breadth and skew have a profound influence over D sp , thereby providing an experimental and conceptual platform for exploiting MWD shape as a simple and modular handle for fine-tuning D sp in block copolymer thin films.

Get out of Fines Free: Recruiting Student Usability Testers via Fine Waivers

Science.gov (United States)

Hockenberry, Benjamin; Blackburn, Kourtney

2016-01-01

St. John Fisher College's Lavery Library's Access Services and Systems departments began a pilot project in which students with overdue fines tested usability of library Web sites in exchange for fine waivers. Circulation staff promoted the program and redeemed fine waiver vouchers at the Checkout Desk, while Systems staff administered testing and…

Image tuning techniques for enhancing the performance of pure permanent magnet undulators with small gap/period ratios

Energy Technology Data Exchange (ETDEWEB)

Tatchyn, R. [Stanford Univ., CA (United States)

1995-12-31

The on-axis field of a small-gap undulator constricted out of pure permanent magnet (PM) blocks arranged in an alternating-dipole (i.e., 2 dipoles/period) array can be substantially varied by positioning monolithic permeable plates above and below the undulator jaws. This simple technique, which can be used to control the 1st harmonic energy in conventional synchrotron radiation (SR) or Free Electron Laser (FEL) applications requiring sub-octave tuning, can also be shown to suppress magnetic inhomogeneities that can contribute to the undulator`s on-axis field errors. If a standard 4 block/period Halbach undulator, composed of PM blocks with square cross sections, is rearranged into an alternating-dipole array with the same period, the peak field that can be generated with superimposed image plates can substantially exceed that of the pure-PM Halbach array. This design technique, which can be viewed as intermediate between the {open_quotes}pure-PM{close_quotes} and standard {open_quotes}hybrid/PM{close_quotes} configurations, provides a potentially cost-effective method of enhancing the performance of small-gap, pure-PM insertion devices. In this paper we report on the analysis and recent characterization of pure-PM undulator structures with superimposed image plates, and discuss possible applications to FEL research.

Heavy superpartners with less tuning from hidden sector renormalisation

International Nuclear Information System (INIS)

Hardy, Edward

2014-01-01

In supersymmetric extensions of the Standard Model, superpartner masses consistent with collider bounds typically introduce significant tuning of the electroweak scale. We show that hidden sector renormalisation can greatly reduce such a tuning if the supersymmetry breaking, or mediating, sector runs through a region of strong coupling not far from the weak scale. In the simplest models, only the tuning due to the gaugino masses is improved, and a weak scale gluino mass in the region of 5 TeV may be obtained with an associated tuning of only one part in ten. In models with more complex couplings between the visible and hidden sectors, the tuning with respect to sfermions can also be reduced. We give an example of a model, with low scale gauge mediation and superpartner masses allowed by current LHC bounds, that has an overall tuning of one part in twenty

Electric-Field-Induced Energy Tuning of On-Demand Entangled-Photon Emission from Self-Assembled Quantum Dots.

Science.gov (United States)

Zhang, Jiaxiang; Zallo, Eugenio; Höfer, Bianca; Chen, Yan; Keil, Robert; Zopf, Michael; Böttner, Stefan; Ding, Fei; Schmidt, Oliver G

2017-01-11

We explore a method to achieve electrical control over the energy of on-demand entangled-photon emission from self-assembled quantum dots (QDs). The device used in our work consists of an electrically tunable diode-like membrane integrated onto a piezoactuator, which is capable of exerting a uniaxial stress on QDs. We theoretically reveal that, through application of the quantum-confined Stark effect to QDs by a vertical electric field, the critical uniaxial stress used to eliminate the fine structure splitting of QDs can be linearly tuned. This feature allows experimental realization of a triggered source of energy-tunable entangled-photon emission. Our demonstration represents an important step toward realization of a solid-state quantum repeater using indistinguishable entangled photons in Bell state measurements.

Mammalian odorant receptor tuning breadth persists across distinct odorant panels.

Directory of Open Access Journals (Sweden)

Devin Kepchia

Full Text Available The molecular receptive range (MRR of a mammalian odorant receptor (OR is the set of odorant structures that activate the OR, while the distribution of these odorant structures across odor space is the tuning breadth of the OR. Variation in tuning breadth is thought to be an important property of ORs, with the MRRs of these receptors varying from narrowly to broadly tuned. However, defining the tuning breadth of an OR is a technical challenge. For practical reasons, a screening panel that broadly covers odor space must be limited to sparse coverage of the many potential structures in that space. When screened with such a panel, ORs with different odorant specificities, but equal tuning breadths, might appear to have different tuning breadths due to chance. We hypothesized that ORs would maintain their tuning breadths across distinct odorant panels. We constructed a new screening panel that was broadly distributed across an estimated odor space and contained compounds distinct from previous panels. We used this new screening panel to test several murine ORs that were previously characterized as having different tuning breadths. ORs were expressed in Xenopus laevis oocytes and assayed by two-electrode voltage clamp electrophysiology. MOR256-17, an OR previously characterized as broadly tuned, responded to nine novel compounds from our new screening panel that were structurally diverse and broadly dispersed across an estimated odor space. MOR256-22, an OR previously characterized as narrowly tuned, responded to a single novel compound that was structurally similar to a previously known ligand for this receptor. MOR174-9, a well-characterized receptor with a narrowly tuned MRR, did not respond to any novel compounds in our new panel. These results support the idea that variation in tuning breadth among these three ORs is not an artifact of the screening protocol, but is an intrinsic property of the receptors.

Ultra-fast dynamics in the nonlinear optical response of silver nanoprism ordered arrays.

Science.gov (United States)

Sánchez-Esquivel, Héctor; Raygoza-Sanchez, Karen Y; Rangel-Rojo, Raúl; Kalinic, Boris; Michieli, Niccolò; Cesca, Tiziana; Mattei, Giovanni

2018-03-15

In this work we present the study of the ultra-fast dynamics of the nonlinear optical response of a honeycomb array of silver triangular nanoprisms, performed using a femtosecond pulsed laser tuned with the dipolar surface plasmon resonance of the nanoarray. Nonlinear absorption and refraction, and their time-dependence, were explored using the z-scan and time-resolved excite-probe techniques. Nonlinear absorption is shown to change sign with the input irradiance and the behavior was explained on the basis of a three-level model. The response time was determined to be in the picosecond regime. A technique based on a variable frequency chopper was also used in order to discriminate the thermal and electronic contributions to the nonlinearity, which were found to have opposite signs. All these findings propel the investigated nanoprism arrays as good candidates for applications in advanced ultra-fast nonlinear nanophotonic devices.

Collective mechanical behavior of multilayer colloidal arrays of hollow nanoparticles.

Science.gov (United States)

Yin, Jie; Retsch, Markus; Thomas, Edwin L; Boyce, Mary C

2012-04-03

The collective mechanical behavior of multilayer colloidal arrays of hollow silica nanoparticles (HSNP) is explored under spherical nanoindentation through a combination of experimental, numerical, and theoretical approaches. The effective indentation modulus E(ind) is found to decrease with an increasing number of layers in a nonlinear manner. The indentation force versus penetration depth behavior for multilayer hollow particle arrays is predicted by an approximate analytical model based on the spring stiffness of the individual particles and the multipoint, multiparticle interactions as well as force transmission between the layers. The model is in good agreement with experiments and with detailed finite element simulations. The ability to tune the effective indentation modulus, E(ind), of the multilayer arrays by manipulating particle geometry and layering is revealed through the model, where E(ind) = (0.725m(-3/2) + 0.275)E(mon) and E(mon) is the monolayer modulus and m is number of layers. E(ind) is seen to plateau with increasing m to E(ind_plateau) = 0.275E(mon) and E(mon) scales with (t/R)(2), t being the particle shell thickness and R being the particle radius. The scaling law governing the nonlinear decrease in indentation modulus with an increase in layer number (E(ind) scaling with m(-3/2)) is found to be similar to that governing the indentation modulus of thin solid films E(ind_solid) on a stiff substrate (where E(ind_solid) scales with h(-1.4) and also decreases until reaching a plateau value) which also decreases with an increase in film thickness h. However, the mechanisms underlying this trend for the colloidal array are clearly different, where discrete particle-to-particle interactions govern the colloidal array behavior in contrast to the substrate constraint on deformation, which governs the thickness dependence of the continuous thin film indentation modulus.

Anne Fine

Directory of Open Access Journals (Sweden)

Philip Gaydon

2015-04-01

Full Text Available An interview with Anne Fine with an introduction and aside on the role of children’s literature in our lives and development, and our adult perceptions of the suitability of childhood reading material. Since graduating from Warwick in 1968 with a BA in Politics and History, Anne Fine has written over fifty books for children and eight for adults, won the Carnegie Medal twice (for Goggle-Eyes in 1989 and Flour Babies in 1992, been a highly commended runner-up three times (for Bill’s New Frock in 1989, The Tulip Touch in 1996, and Up on Cloud Nine in 2002, been shortlisted for the Hans Christian Andersen Award (the highest recognition available to a writer or illustrator of children’s books, 1998, undertaken the positon of Children’s Laureate (2001-2003, and been awarded an OBE for her services to literature (2003. Warwick presented Fine with an Honorary Doctorate in 2005. Philip Gaydon’s interview with Anne Fine was recorded as part of the ‘Voices of the University’ oral history project, co-ordinated by Warwick’s Institute of Advanced Study.

Optical frequency-domain reflectometry using multiple wavelength-swept elements of a DFB laser array

Science.gov (United States)

DiLazaro, Tom; Nehmetallah, Georges

2017-02-01

Coherent optical frequency-domain reflectometry (C-OFDR) is a distance measurement technique with significant sensitivity and detector bandwidth advantages over normal time-of-flight methods. Although several swept-wavelength laser sources exist, many exhibit short coherence lengths, or require precision mechanical tuning components. Semiconductor distributed feedback lasers (DFBs) are advantageous as a mid-to-long range OFDR source because they exhibit a narrow linewidth and can be rapidly tuned simply via injection current. However, the sweep range of an individual DFB is thermally limited. Here, we present a novel high-resolution OFDR system that uses a compact, monolithic 12-element DFB array to create a continuous, gap-free sweep over a wide wavelength range. Wavelength registration is provided by the incorporation of a HCN gas cell and reference interferometer. The wavelength-swept spectra of the 12 DFBs are combined in post-processing to achieve a continuous total wavelength sweep of more than 40 nm (5.4 THz) in the telecommunications C-Band range.

Numerical Study of a Crossed Loop Coil Array for Parallel Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Hernandez, J.; Solis, S. E.; Rodriguez, A. O.

2008-01-01

A coil design has been recently proposed by Temnikov (Instrum Exp Tech. 2005;48;636-637), with higher experimental signal-to-noise ratio than that of the birdcage coil. It is also claimed that it is possible to individually tune it with a single chip capacitor. This coil design shows a great resemble to the gradiometer coil. These results motivated us to numerically simulate a three-coil array for parallel magnetic resonance imaging and in vivo magnetic resonance spectroscopy with multi nuclear capability. The magnetic field was numerical simulated by solving Maxwell's equations with the finite element method. Uniformity profiles were calculated at the midsection for one single coil and showed a good agreement with the experimental data. Then, two more coils were added to form two different coil arrays: coil elements were equally distributed by an angle of a 30 deg. angle. Then, uniformity profiles were calculated again for all cases at the midsection. Despite the strong interaction among all coil elements, very good field uniformity can be achieved. These numerical results indicate that this coil array may be a good choice for magnetic resonance imaging parallel imaging

70 MeV injector auto tuning system handbook

International Nuclear Information System (INIS)

Ellis, J.E.; Munn, R.W.; Sandels, E.G.

1976-06-01

The handbook is in three sections: (1) description and location; (2) operating instructions; and (3) design notes on the tank and debuncher auto tuning systems for the 70 MeV injector. The purpose of the auto tuning system is to maintain the 'tune' of the four tanks and debuncher to within a few Hz, stabilizing against changes of temperature and other physical factors affecting the resonant frequency of the tanks. (U.K.)

Broader visual orientation tuning in patients with schizophrenia

Directory of Open Access Journals (Sweden)

Ariel eRokem

2011-11-01

Full Text Available Reduced gamma-aminobutyric acid (GABA levels in cerebral cortex are thought to contribute to information processing deficits in patients with schizophrenia (SZ, and we have previously reported lower in vivo GABA levels in the visual cortex of patients with SZ. GABA-mediated inhibition plays a role in sharpening orientation tuning of visual cortical neurons. Therefore, we predicted that tuning for visual stimulus orientation would be wider in SZ. We measured orientation tuning with a psychophysical procedure in which subjects performed a target detection task of a low-contrast oriented grating, following adaptation to a high-contrast grating. Contrast detection thresholds were determined for a range of adapter-target orientation offsets. For both SZ and healthy controls, contrast thresholds decreased as orientation offset increased, suggesting that this tuning curve reflects the selectivity of visual cortical neurons for stimulus orientation. After accounting for generalized deficits in task performance in SZ, there was no difference between patients and controls for detection of target stimuli having either the same orientation as the adapter or orientations far from the adapter. However, patients’ thresholds were significantly higher for intermediate adapter-target offsets. In addition, the mean width parameter of a Gaussian fit to the psychophysical orientation tuning curves was significantly larger for the patient group. We also present preliminary data relating visual cortical GABA levels, as measured with magnetic resonance spectroscopy, and orientation tuning width. These results suggest that our finding of broader orientation tuning in SZ may be due to diminished visual cortical GABA levels.

ATLAS tunes of PYTHIA 6 and Pythia 8 for MC11

CERN Document Server

The ATLAS collaboration

2011-01-01

We present the latest developments of the ATLAS MC generator tuning project for the Pythia family of event generators, including the C++ Pythia 8 code for the first time. The PYTHIA 6 tunes presented here, titled AMBT2B and AUET2B and constructed for a variety of PDFs, constitute alternatives to the AMBT2/AUET2 tunes previously presented as a candidate for MC11 event simulation. They systematically differ from the AMBT2/AUET2 PYTHIA 6 tunes in the treatment of alpha_S, to address concerns with those tunes. Systematic tune variations are also presented. The Pythia 8 tunes have been constructed for two different PDFs, and are aimed at an optimal description of minimum bias, for use in pile-up simulation. PDF-sensitive effects are observed and discussed in the MPI tunings of both generators.

Dark interactions and cosmological fine-tuning

Energy Technology Data Exchange (ETDEWEB)

Quartin, Miguel; Calvao, Mauricio O; Joras, Sergio E; Reis, Ribamar R R; Waga, Ioav, E-mail: mquartin@if.ufrj.br, E-mail: orca@if.ufrj.br, E-mail: joras@if.ufrj.br, E-mail: ribamar@if.ufrj.br, E-mail: ioav@if.ufrj.br [Instituto de Fisica, Universidade Federal do Rio de Janeiro, CEP 21941-972, Rio de Janeiro, RJ (Brazil)

2008-05-15

Cosmological models involving an interaction between dark matter and dark energy have been proposed in order to solve the so-called coincidence problem. Different forms of coupling have been studied, but there have been claims that observational data seem to narrow (some of) them down to something annoyingly close to the {Lambda}CDM (CDM: cold dark matter) model, thus greatly reducing their ability to deal with the problem in the first place. The smallness problem of the initial energy density of dark energy has also been a target of cosmological models in recent years. Making use of a moderately general coupling scheme, this paper aims to unite these different approaches and shed some light on whether this class of models has any true perspective in suppressing the aforementioned issues that plague our current understanding of the universe, in a quantitative and unambiguous way.

Fine-tuning satellite-based rainfall estimates

Science.gov (United States)

Harsa, Hastuadi; Buono, Agus; Hidayat, Rahmat; Achyar, Jaumil; Noviati, Sri; Kurniawan, Roni; Praja, Alfan S.

2018-05-01

Rainfall datasets are available from various sources, including satellite estimates and ground observation. The locations of ground observation scatter sparsely. Therefore, the use of satellite estimates is advantageous, because satellite estimates can provide data on places where the ground observations do not present. However, in general, the satellite estimates data contain bias, since they are product of algorithms that transform the sensors response into rainfall values. Another cause may come from the number of ground observations used by the algorithms as the reference in determining the rainfall values. This paper describe the application of bias correction method to modify the satellite-based dataset by adding a number of ground observation locations that have not been used before by the algorithm. The bias correction was performed by utilizing Quantile Mapping procedure between ground observation data and satellite estimates data. Since Quantile Mapping required mean and standard deviation of both the reference and the being-corrected data, thus the Inverse Distance Weighting scheme was applied beforehand to the mean and standard deviation of the observation data in order to provide a spatial composition of them, which were originally scattered. Therefore, it was possible to provide a reference data point at the same location with that of the satellite estimates. The results show that the new dataset have statistically better representation of the rainfall values recorded by the ground observation than the previous dataset.

Optimised dipper fine tunes shovel performance

Energy Technology Data Exchange (ETDEWEB)

Fiscor, S.

2005-06-01

Joint efforts between mine operators, OEMs, and researchers yields unexpected benefits from dippers for shovels for coal, oil, or hardrock mining that can now be tailored to meet site-specific conditions. The article outlines a process being developed by CRCMining and P & H MIning Equipment to optimise the dipper that involves rapid prototyping and scale modelling of the dipper and the mine conditions. Scale models have been successfully field tested. 2 photos.

Host Genetics: Fine-Tuning Innate Signaling

OpenAIRE

Fellay, Jacques; Goldstein, David B.

2007-01-01

A polymorphism modulating innate immunity signal transduction has recently been shown to influence human susceptibility to many different infections, providing one more indication of the potential of host genetics to reveal physiological pathways and mechanisms that influence resistance to infectious diseases.

Riboregulators: Fine-Tuning Virulence in Shigella.

Science.gov (United States)

Fris, Megan E; Murphy, Erin R

2016-01-01

Within the past several years, RNA-mediated regulation (ribo-regulation) has become increasingly recognized for its importance in controlling critical bacterial processes. Regulatory RNA molecules, or riboregulators, are perpetually responsive to changes within the micro-environment of a bacterium. Notably, several characterized riboregulators control virulence in pathogenic bacteria, as is the case for each riboregulator characterized to date in Shigella. The timing of virulence gene expression and the ability of the pathogen to adapt to rapidly changing environmental conditions is critical to the establishment and progression of infection by Shigella species; ribo-regulators mediate each of these important processes. This mini review will present the current state of knowledge regarding RNA-mediated regulation in Shigella by detailing the characterization and function of each identified riboregulator in these pathogens.

Fine-grained leukocyte classification with deep residual learning for microscopic images.

Science.gov (United States)

Qin, Feiwei; Gao, Nannan; Peng, Yong; Wu, Zizhao; Shen, Shuying; Grudtsin, Artur

2018-08-01

Leukocyte classification and cytometry have wide applications in medical domain, previous researches usually exploit machine learning techniques to classify leukocytes automatically. However, constrained by the past development of machine learning techniques, for example, extracting distinctive features from raw microscopic images are difficult, the widely used SVM classifier only has relative few parameters to tune, these methods cannot efficiently handle fine-grained classification cases when the white blood cells have up to 40 categories. Based on deep learning theory, a systematic study is conducted on finer leukocyte classification in this paper. A deep residual neural network based leukocyte classifier is constructed at first, which can imitate the domain expert's cell recognition process, and extract salient features robustly and automatically. Then the deep neural network classifier's topology is adjusted according to the prior knowledge of white blood cell test. After that the microscopic image dataset with almost one hundred thousand labeled leukocytes belonging to 40 categories is built, and combined training strategies are adopted to make the designed classifier has good generalization ability. The proposed deep residual neural network based classifier was tested on microscopic image dataset with 40 leukocyte categories. It achieves top-1 accuracy of 77.80%, top-5 accuracy of 98.75% during the training procedure. The average accuracy on the test set is nearly 76.84%. This paper presents a fine-grained leukocyte classification method for microscopic images, based on deep residual learning theory and medical domain knowledge. Experimental results validate the feasibility and effectiveness of our approach. Extended experiments support that the fine-grained leukocyte classifier could be used in real medical applications, assist doctors in diagnosing diseases, reduce human power significantly. Copyright © 2018 Elsevier B.V. All rights reserved.

Self-tuning control studies of the plasma vertical position problem

International Nuclear Information System (INIS)

Zheng, Guang Lin; Wellstead, P.E.; Browne, M.L.

1993-01-01

The plasma vertical position system in a tokamak device can be open-loop unstable with time-varying dynamics, such that the instability increases with system dynamical changes. Time-varying unstable dynamics makes the plasma vertical position a particularly difficult one to control with traditional fixed-coefficient controllers. A self-tuning technique offers a new solution of the plasma vertical position control problem by an adaptive control approach. Specifically, the self-tuning controller automatically tunes the controller parameters without an a priori knowledge of the system dynamics and continuously tracks dynamical changes within the system, thereby providing the system with auto-tuning and adaptive tuning capabilities. An overview of the self-tuning methods is given, and their applicability to a simulation of the Joint European Torus (JET) vertical plasma positions system is illustrated. Specifically, the applicability of pole-assignment and generalized predictive control self-tuning methods to the vertical plasma position system is demonstrated. 26 refs., 16 figs., 1 tab

Embodiment as First Affordance: Tinkering, Tuning, Tracking

Directory of Open Access Journals (Sweden)

Ben Spatz

2017-01-01

Full Text Available This article begins from a discussion of philosophical realism and the turn towards close analysis of skilled material practices that characterizes many recent critical interventions. I examine the roots of this turn and suggest that skilled practice is a privileged site for the enactment and testing of realist ontologies. However, I question the extent to which realist thinkers have emphasized practices in which materials outside the human body are central over those in which embodiment itself is the primary medium of practice. Thinkers of realist ontology, I argue, have neglected embodiment as the primary site of an engagement with the fine-grained detail of the world. In contrast, I propose that realist ontologies developed through reference to technological engagements not only apply equally well to embodied practices but actually find their original and primary manifestation there. The body itself is the ‘first affordance’ and the site at which questions of realism and objectivity are first encountered and resolved in practice. I illustrate this point by considering how three modes of material engagement — tinkering, tuning, and tracking — manifest in embodied practices ranging from dance and sport to those of everyday life. I conclude by emphasizing the continuing political importance of embodiment as first affordance and its crucial place as a ‘fragile junction’ between ecology and technology.

A frequency domain approach for MPC tuning

NARCIS (Netherlands)

Özkan, L.; Meijs, J.B.; Backx, A.C.P.M.; Karimi, I.A.; Srinivasan, R.

2012-01-01

This paper presents a frequency domain based approach to tune the penalty weights in the model predictive control (MPC) formulation. The two-step tuning method involves the design of a favourite controller taking into account the model-plant mismatch followed by the controller matching. We implement

Accurate guitar tuning by cochlear implant musicians.

Directory of Open Access Journals (Sweden)

Thomas Lu

Full Text Available Modern cochlear implant (CI users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼ 30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task.

Metal–organic frameworks to satisfy gas upgrading demands: fine-tuning the soc-MOF platform for the operative removal of H2S

KAUST Repository

Belmabkhout, Youssef

2017-01-06

A cooperative experimental/modeling strategy was used to unveil the structure/gas separation performance relationship for a series of isostructural metal-organic frameworks (MOFs) with soc-topology (square-octahedral) hosting different extra-framework counter ions (NO3-, Cl- and Br-). In3+-, Fe3+-, Ga3+-and the newly isolated Al(III)-based isostructural soc-MOF were extensively studied and evaluated for the separation-based production of high-quality fuels (i.e., CH4, C3H8 and n-C4H10) and olefins. The structural/chemical fine-tuning of the soc-MOF platform promoted equilibrium-based selectivity toward C2+ (C2H6, C2H4, C3H6 C3H8 and n-C4H10) and conferred the desired chemical stability toward H2S. The noted dual chemical stability and gas/vapor selectivity, which have rarely been reported for equilibrium-based separation agents, are essential for the production of high-purity H-2, CH4 and C2+ fractions in high yields. Interestingly, the evaluated soc-MOF analogues exhibited high selectivity for C2H4, C3H6 and n-C4H10. In particular, the Fe, Ga and Al analogues presented relatively enhanced C2+/CH4 adsorption selectivities. Notably, the Ga and Al analogues were found to be technically preferable because their structural integrities and separation performances were maintained upon exposure to H2S, indicating that these materials are highly tolerant to H2S. Therefore, the Ga-soc-MOF was further examined for the selective adsorption of H2S in the presence of CO2-and CH4-containing streams, such as refinery-off gases (ROG) and natural gas (NG). Grand canonical Monte Carlo (GCMC) simulations based on a specific force field describing the interactions between the guest molecules and the Ga sites supported and confirmed the considerably higher affinity of the Ga-soc-MOF for C2+ (as exemplified by n-C4H10) than for CH4. The careful selection of an appropriate metal for the trinuclear inorganic molecular building block (MBB), i. e., a Ga metal center, imbues the soc

Further ATLAS tunes of PYTHIA6 and Pythia 8

CERN Document Server

The ATLAS collaboration

2011-01-01

We present the latest developments of the ATLAS MC generator tuning project for the Pythia family of event generators, including the C++ Pythia 8 code. The PYTHIA 6 tunes presented here complete the ``AUET2B'' set by addition of parton shower and multi-parton interaction model tunings with three next-to-leading order (NLO) PDFs in addition to the leading-order and MC-adapted PDFs previously presented. This note also presents systematic variation ``eigentunes'' for the parton shower configurations in the AMBT2B/AUET2B tune series. The Pythia 8 MPI tunes in this note have been constructed for six different PDFs, making use of a new $x$-dependent hadronic matter distribution model. MPI eigentunes are constructed for the PDFs intended for use in ATLAS bulk MC production.

Superconducting-normal phase boundary of quasicrystalline arrays in a magnetic field

International Nuclear Information System (INIS)

Nori, F.; Niu, Q.; Fradkin, E.; Chang, S.

1987-01-01

We study the effect of frustration, induced by a mangnetic field, on the superconducting diamagnetic properties of two-dimensional quasicrystalline arrays. In particular, we calculate the superconducting-normal phase boundary, T/sub c/(H), for several geometries with quasicrystalline order. The agreement between our theoretically obtained phase boundaries and the experimentally obtained ones is very good. We also propose a new way of analytically analyzing the overall and the fine structure of T/sub c/(H) in terms of short- and long-range correlations among tiles

What is a natural SUSY scenario?

Energy Technology Data Exchange (ETDEWEB)

Casas, J. Alberto; Moreno, Jesús M.; Robles, Sandra; Rolbiecki, Krzysztof [Instituto de Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Zaldívar, Bryan [Service de Physique Théorique, Université Libre de Bruxelles,Boulevard du Triomphe, CP225, 1050 Brussels (Belgium)

2015-06-11

The idea of “Natural SUSY', understood as a supersymmetric scenario where the fine-tuning is as mild as possible, is a reasonable guide to explore supersymmetric phenomenology. In this paper, we re-examine this issue in the context of the MSSM including several improvements, such as the mixing of the fine-tuning conditions for different soft terms and the presence of potential extra fine-tunings that must be combined with the electroweak one. We give tables and plots that allow to easily evaluate the fine-tuning and the corresponding naturalness bounds for any theoretical model defined at any high-energy (HE) scale. Then, we analyze in detail the complete fine-tuning bounds for the unconstrained MSSM, defined at any HE scale. We show that Natural SUSY does not demand light stops. Actually, an average stop mass below 800 GeV is disfavored, though one of the stops might be very light. Regarding phenomenology, the most stringent upper bound from naturalness is the one on the gluino mass, which typically sets the present level fine-tuning at O(1%). However, this result presents a strong dependence on the HE scale. E.g. if the latter is 10{sup 7} GeV the level of fine-tuning is ∼ four times less severe. Finally, the most robust result of Natural SUSY is by far that Higgsinos should be rather light, certainly below 700 GeV for a fine-tuning of O(1%) or milder. Incidentally, this upper bound is not far from ≃1 TeV, which is the value required if dark matter is made of Higgsinos.

Predictive Performance Tuning of OpenACC Accelerated Applications

KAUST Repository

Siddiqui, Shahzeb

2014-05-04

Graphics Processing Units (GPUs) are gradually becoming mainstream in supercomputing as their capabilities to significantly accelerate a large spectrum of scientific applications have been clearly identified and proven. Moreover, with the introduction of high level programming models such as OpenACC [1] and OpenMP 4.0 [2], these devices are becoming more accessible and practical to use by a larger scientific community. However, performance optimization of OpenACC accelerated applications usually requires an in-depth knowledge of the hardware and software specifications. We suggest a prediction-based performance tuning mechanism [3] to quickly tune OpenACC parameters for a given application to dynamically adapt to the execution environment on a given system. This approach is applied to a finite difference kernel to tune the OpenACC gang and vector clauses for mapping the compute kernels into the underlying accelerator architecture. Our experiments show a significant performance improvement against the default compiler parameters and a faster tuning by an order of magnitude compared to the brute force search tuning.

Natural implementation of neutralino dark matter

International Nuclear Information System (INIS)

King, Steve F.; Roberts, Jonathan P.

2006-01-01

The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to 'supernatural dark matter' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed 'well tempered neutralino' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of 'supernatural dark matter' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains

Natural implementation of neutralino dark matter

Science.gov (United States)

King, Steve F.; Roberts, Jonathan P.

2006-09-01

The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to ``supernatural dark matter'' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed ``well tempered neutralino'' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of ``supernatural dark matter'' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains.

A novel two-level dynamic parallel data scheme for large 3-D SN calculations

International Nuclear Information System (INIS)

Sjoden, G.E.; Shedlock, D.; Haghighat, A.; Yi, C.

2005-01-01

We introduce a new dynamic parallel memory optimization scheme for executing large scale 3-D discrete ordinates (Sn) simulations on distributed memory parallel computers. In order for parallel transport codes to be truly scalable, they must use parallel data storage, where only the variables that are locally computed are locally stored. Even with parallel data storage for the angular variables, cumulative storage requirements for large discrete ordinates calculations can be prohibitive. To address this problem, Memory Tuning has been implemented into the PENTRAN 3-D parallel discrete ordinates code as an optimized, two-level ('large' array, 'small' array) parallel data storage scheme. Memory Tuning can be described as the process of parallel data memory optimization. Memory Tuning dynamically minimizes the amount of required parallel data in allocated memory on each processor using a statistical sampling algorithm. This algorithm is based on the integral average and standard deviation of the number of fine meshes contained in each coarse mesh in the global problem. Because PENTRAN only stores the locally computed problem phase space, optimal two-level memory assignments can be unique on each node, depending upon the parallel decomposition used (hybrid combinations of angular, energy, or spatial). As demonstrated in the two large discrete ordinates models presented (a storage cask and an OECD MOX Benchmark), Memory Tuning can save a substantial amount of memory per parallel processor, allowing one to accomplish very large scale Sn computations. (authors)

Wafer-Scale Hierarchical Nanopillar Arrays Based on Au Masks and Reactive Ion Etching for Effective 3D SERS Substrate

Directory of Open Access Journals (Sweden)

Dandan Men

2018-02-01

Full Text Available Two-dimensional (2D periodic micro/nanostructured arrays as SERS substrates have attracted intense attention due to their excellent uniformity and good stability. In this work, periodic hierarchical SiO2 nanopillar arrays decorated with Ag nanoparticles (NPs with clean surface were prepared on a wafer-scale using monolayer Au NP arrays as masks, followed by reactive ion etching (RIE, depositing Ag layer and annealing. For the prepared SiO2 nanopillar arrays decorated with Ag NPs, the size of Ag NPs was tuned from ca. 24 to 126 nanometers by controlling the deposition thickness of Ag film. Importantly, the SiO2 nanopillar arrays decorated with Ag NPs could be used as highly sensitive SERS substrate for the detection of 4-aminothiophenol (4-ATP and rhodamine 6G (R6G due to the high loading of Ag NPs and a very uniform morphology. With a deposition thickness of Ag layer of 30 nm, the SiO2 nanopillar arrays decorated with Ag NPs exhibited the best sensitive SERS activity. The excellent SERS performance of this substrate is mainly attributed to high-density “hotspots” derived from nanogaps between Ag NPs. Furthermore, this strategy might be extended to synthesize other nanostructured arrays with a large area, which are difficult to be prepared only via conventional wet-chemical or physical methods.

Wafer-Scale Hierarchical Nanopillar Arrays Based on Au Masks and Reactive Ion Etching for Effective 3D SERS Substrate.

Science.gov (United States)

Men, Dandan; Wu, Yingyi; Wang, Chu; Xiang, Junhuai; Yang, Ganlan; Wan, Changjun; Zhang, Honghua

2018-02-04

Two-dimensional (2D) periodic micro/nanostructured arrays as SERS substrates have attracted intense attention due to their excellent uniformity and good stability. In this work, periodic hierarchical SiO₂ nanopillar arrays decorated with Ag nanoparticles (NPs) with clean surface were prepared on a wafer-scale using monolayer Au NP arrays as masks, followed by reactive ion etching (RIE), depositing Ag layer and annealing. For the prepared SiO₂ nanopillar arrays decorated with Ag NPs, the size of Ag NPs was tuned from ca. 24 to 126 nanometers by controlling the deposition thickness of Ag film. Importantly, the SiO₂ nanopillar arrays decorated with Ag NPs could be used as highly sensitive SERS substrate for the detection of 4-aminothiophenol (4-ATP) and rhodamine 6G (R6G) due to the high loading of Ag NPs and a very uniform morphology. With a deposition thickness of Ag layer of 30 nm, the SiO₂ nanopillar arrays decorated with Ag NPs exhibited the best sensitive SERS activity. The excellent SERS performance of this substrate is mainly attributed to high-density "hotspots" derived from nanogaps between Ag NPs. Furthermore, this strategy might be extended to synthesize other nanostructured arrays with a large area, which are difficult to be prepared only via conventional wet-chemical or physical methods.

Optimal Tuning of Decentralized PI Controller of Nonlinear Multivariable Process Using Archival Based Multiobjective Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

R. Kotteeswaran

2014-01-01

Full Text Available A Multiobjective Particle Swarm Optimization (MOPSO algorithm is proposed to fine-tune the baseline PI controller parameters of Alstom gasifier. The existing baseline PI controller is not able to meet the performance requirements of Alstom gasifier for sinusoidal pressure disturbance at 0% load. This is considered the major drawback of controller design. A best optimal solution for Alstom gasifier is obtained from a set of nondominated solutions using MOPSO algorithm. Performance of gasifier is investigated at all load conditions. The controller with optimized controller parameters meets all the performance requirements at 0%, 50%, and 100% load conditions. The investigations are also extended for variations in coal quality, which shows an improved stability of the gasifier over a wide range of coal quality variations.

Computationally Efficient 2D DOA Estimation for L-Shaped Array with Unknown Mutual Coupling

Directory of Open Access Journals (Sweden)

Yang-Yang Dong

2018-01-01

Full Text Available Although L-shaped array can provide good angle estimation performance and is easy to implement, its two-dimensional (2D direction-of-arrival (DOA performance degrades greatly in the presence of mutual coupling. To deal with the mutual coupling effect, a novel 2D DOA estimation method for L-shaped array with low computational complexity is developed in this paper. First, we generalize the conventional mutual coupling model for L-shaped array and compensate the mutual coupling blindly via sacrificing a few sensors as auxiliary elements. Then we apply the propagator method twice to mitigate the effect of strong source signal correlation effect. Finally, the estimations of azimuth and elevation angles are achieved simultaneously without pair matching via the complex eigenvalue technique. Compared with the existing methods, the proposed method is computationally efficient without spectrum search or polynomial rooting and also has fine angle estimation performance for highly correlated source signals. Theoretical analysis and simulation results have demonstrated the effectiveness of the proposed method.

Distributed Tuning of Boundary Resources

DEFF Research Database (Denmark)

Eaton, Ben; Elaluf-Calderwood, Silvia; Sørensen, Carsten

2015-01-01

in the context of a paradoxical tension between the logic of generative and democratic innovations and the logic of infrastructural control. Boundary resources play a critical role in managing the tension as a firm that owns the infrastructure can secure its control over the service system while independent...... firms can participate in the service system. In this study, we explore the evolution of boundary resources. Drawing on Pickering’s (1993) and Barrett et al.’s (2012) conceptualizations of tuning, the paper seeks to forward our understanding of how heterogeneous actors engage in the tuning of boundary...

Towards automatic parameter tuning of stream processing systems

KAUST Repository

Bilal, Muhammad; Canini, Marco

2017-01-01

for automating parameter tuning for stream-processing systems. Our framework supports standard black-box optimization algorithms as well as a novel gray-box optimization algorithm. We demonstrate the multiple benefits of automated parameter tuning in optimizing

Analyses of fine paste ceramics

International Nuclear Information System (INIS)

Sabloff, J.A.

1980-01-01

Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics

Towards Tuning the Mechanical Properties of Three-Dimensional Collagen Scaffolds Using a Coupled Fiber-Matrix Model

Directory of Open Access Journals (Sweden)

Shengmao Lin

2015-08-01

Full Text Available Scaffold mechanical properties are essential in regulating the microenvironment of three-dimensional cell culture. A coupled fiber-matrix numerical model was developed in this work for predicting the mechanical response of collagen scaffolds subjected to various levels of non-enzymatic glycation and collagen concentrations. The scaffold was simulated by a Voronoi network embedded in a matrix. The computational model was validated using published experimental data. Results indicate that both non-enzymatic glycation-induced matrix stiffening and fiber network density, as regulated by collagen concentration, influence scaffold behavior. The heterogeneous stress patterns of the scaffold were induced by the interfacial mechanics between the collagen fiber network and the matrix. The knowledge obtained in this work could help to fine-tune the mechanical properties of collagen scaffolds for improved tissue regeneration applications.

Rational Diversification of a Promoter Providing Fine-Tuned Expression and Orthogonal Regulation for Synthetic Biology

Science.gov (United States)

Blount, Benjamin A.; Weenink, Tim; Vasylechko, Serge; Ellis, Tom

2012-01-01

Yeast is an ideal organism for the development and application of synthetic biology, yet there remain relatively few well-characterised biological parts suitable for precise engineering of this chassis. In order to address this current need, we present here a strategy that takes a single biological part, a promoter, and re-engineers it to produce a fine-graded output range promoter library and new regulated promoters desirable for orthogonal synthetic biology applications. A highly constitutive Saccharomyces cerevisiae promoter, PFY1p, was identified by bioinformatic approaches, characterised in vivo and diversified at its core sequence to create a 36-member promoter library. TetR regulation was introduced into PFY1p to create a synthetic inducible promoter (iPFY1p) that functions in an inverter device. Orthogonal and scalable regulation of synthetic promoters was then demonstrated for the first time using customisable Transcription Activator-Like Effectors (TALEs) modified and designed to act as orthogonal repressors for specific PFY1-based promoters. The ability to diversify a promoter at its core sequences and then independently target Transcription Activator-Like Orthogonal Repressors (TALORs) to virtually any of these sequences shows great promise toward the design and construction of future synthetic gene networks that encode complex “multi-wire” logic functions. PMID:22442681

Rational diversification of a promoter providing fine-tuned expression and orthogonal regulation for synthetic biology.

Science.gov (United States)

Blount, Benjamin A; Weenink, Tim; Vasylechko, Serge; Ellis, Tom

2012-01-01

Yeast is an ideal organism for the development and application of synthetic biology, yet there remain relatively few well-characterised biological parts suitable for precise engineering of this chassis. In order to address this current need, we present here a strategy that takes a single biological part, a promoter, and re-engineers it to produce a fine-graded output range promoter library and new regulated promoters desirable for orthogonal synthetic biology applications. A highly constitutive Saccharomyces cerevisiae promoter, PFY1p, was identified by bioinformatic approaches, characterised in vivo and diversified at its core sequence to create a 36-member promoter library. TetR regulation was introduced into PFY1p to create a synthetic inducible promoter (iPFY1p) that functions in an inverter device. Orthogonal and scalable regulation of synthetic promoters was then demonstrated for the first time using customisable Transcription Activator-Like Effectors (TALEs) modified and designed to act as orthogonal repressors for specific PFY1-based promoters. The ability to diversify a promoter at its core sequences and then independently target Transcription Activator-Like Orthogonal Repressors (TALORs) to virtually any of these sequences shows great promise toward the design and construction of future synthetic gene networks that encode complex "multi-wire" logic functions.

Tuning and backreaction in F-term axion monodromy inflation

Directory of Open Access Journals (Sweden)

Arthur Hebecker

2015-05-01

Full Text Available We continue the development of axion monodromy inflation, focusing in particular on the backreaction of complex structure moduli. In our setting, the shift symmetry comes from a partial large complex structure limit of the underlying type IIB orientifold or F-theory fourfold. The coefficient of the inflaton term in the superpotential has to be tuned small to avoid conflict with Kähler moduli stabilisation. To allow such a tuning, this coefficient necessarily depends on further complex structure moduli. At large values of the inflaton field, these moduli are then in danger of backreacting too strongly. To avoid this, further tunings are necessary. In weakly coupled type IIB theory at the orientifold point, implementing these tunings appears to be difficult if not impossible. However, fourfolds or models with mobile D7-branes provide enough structural freedom. We calculate the resulting inflaton potential and study the feasibility of the overall tuning given the limited freedom of the flux landscape. Our preliminary investigations suggest that, even imposing all tuning conditions, the remaining choice of flux vacua can still be large enough for such models to provide a promising path to large-field inflation in string theory.

Analyses of fine paste ceramics

Energy Technology Data Exchange (ETDEWEB)

Sabloff, J A [ed.

1980-01-01

Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics. (DLC)

Self tuning fuzzy PID type load and frequency controller

International Nuclear Information System (INIS)

Yesil, E.; Guezelkaya, M.; Eksin, I.

2004-01-01

In this paper, a self tuning fuzzy PID type controller is proposed for solving the load frequency control (LFC) problem. The fuzzy PID type controller is constructed as a set of control rules, and the control signal is directly deduced from the knowledge base and the fuzzy inference. Moreover, there exists a self tuning mechanism that adjusts the input scaling factor corresponding to the derivative coefficient and the output scaling factor corresponding to the integral coefficient of the PID type fuzzy logic controller in an on-line manner. The self tuning mechanism depends on the peak observer idea, and this idea is modified and adapted to the LFC problem. A two area interconnected system is assumed for demonstrations. The proposed self tuning fuzzy PID type controller has been compared with the fuzzy PID type controller without a self tuning mechanism and the conventional integral controller through some performance indices

The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

Science.gov (United States)

Yoo, Hana; Park, Soojin

2010-06-01

We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm × 5 cm.

The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hana; Park, Soojin, E-mail: spark@unist.ac.kr [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology, Banyeon-ri 100, Ulsan 689-798 (Korea, Republic of)

2010-06-18

We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm x 5 cm.

Thermoelectric properties of fine-grained FeVSb half-Heusler alloys tuned to p-type by substituting vanadium with titanium

International Nuclear Information System (INIS)

Zou, Minmin; Li, Jing-Feng; Kita, Takuji

2013-01-01

Fine-grained Ti-doped FeVSb half-Heusler alloys were synthesized by combining mechanical alloying and spark plasma sintering and their thermoelectric properties were investigated with an emphasis on the influences of Ti doping and phase purity. It was found that substituting V with Ti can change the electrical transport behavior from n-type to p-type due to one less valence electron of Ti than V, and the sample with nominal composition FeV 0.8 Ti 0.4 Sb exhibits the largest Seebeck coefficient and the maximum power factor. By optimizing the sintering temperature and applying annealing treatment, the power factor is significantly improved and the thermal conductivity is reduced simultaneously, resulting in a ZT value of 0.43 at 500 °C, which is relatively high as for p-type half-Heusler alloys containing earth-abundant elements. - Graphical abstract: Fine-grained Ti-doped FeVSb alloys were prepared by the MA-SPS method. The maximum ZT value reaches 0.43 at 500 °C, which is relatively high for p-type half-Heusler alloys. Highlights: ► Ti-doped FeVSb half-Heusler alloys were synthesized by combining MA and SPS. ► Substituting V with Ti changes the electrical behavior from n-type to p-type. ► Thermoelectric properties are improved by optimizing sintering temperature. ► Thermoelectric properties are further improved by applying annealing treatment. ► A high ZT value of 0.43 is obtained at 500 °C for p-type Ti-doped FeVSb alloys.

Non-parametric Tuning of PID Controllers A Modified Relay-Feedback-Test Approach

CERN Document Server

Boiko, Igor

2013-01-01

The relay feedback test (RFT) has become a popular and efficient  tool used in process identification and automatic controller tuning. Non-parametric Tuning of PID Controllers couples new modifications of classical RFT with application-specific optimal tuning rules to form a non-parametric method of test-and-tuning. Test and tuning are coordinated through a set of common parameters so that a PID controller can obtain the desired gain or phase margins in a system exactly, even with unknown process dynamics. The concept of process-specific optimal tuning rules in the nonparametric setup, with corresponding tuning rules for flow, level pressure, and temperature control loops is presented in the text.   Common problems of tuning accuracy based on parametric and non-parametric approaches are addressed. In addition, the text treats the parametric approach to tuning based on the modified RFT approach and the exact model of oscillations in the system under test using the locus of a perturbedrelay system (LPRS) meth...

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.; Theodorou, I. G.; Centeno, A.; Petrov, P. K.; Alford, N. M.; Ryan, M. P.; Xie, F.

2016-01-01

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.

2016-12-28

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Comparison of the Efficiency of Tuned Mass and Tuned Liquid Dampers at High-Rise Structures under Near and Far Fault Earthquakes

Directory of Open Access Journals (Sweden)

Hamed Rahman Shokrgozar

2017-02-01

Full Text Available Tuned mass and tuned liquid dampers are most common passive control systems that used for decrease of seismic responses of buildings. In this study, the performance of high-rise buildings with TM and TL dampers are evaluated under seven near-fault and seven far-fault earthquakes. For this purpose, a twenty-four stories steel moment frame building has been considered and the time history dynamic analyses are performed for both of controlled and uncontrolled states. Moreover, this building has been also modelled with five various mass, stiffness and damping ratios.The results have been shown that decreasing the structural responses at tall buildings against near-fault earthquakes are more than far-fault earthquakes due to the effect of higher modes. Furthermore, the tuned mass damper has better performance at decreasing of the responses in comparison of tuned liquid dampers.

Broad electrical tuning of plasmonic nanoantennas at visible frequencies

Energy Technology Data Exchange (ETDEWEB)

Hoang, Thang B. [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708 (United States); Mikkelsen, Maiken H., E-mail: m.mikkelsen@duke.edu [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708 (United States); Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States)

2016-05-02

We report an experimental demonstration of electrical tuning of plasmon resonances of optical nanopatch antennas over a wide wavelength range. The antennas consist of silver nanocubes separated from a gold film by a thin 8 nm polyelectrolyte spacer layer. By using ionic liquid and indium tin oxide coated glass as a top electrode, we demonstrate dynamic and reversible tuning of the plasmon resonance over 100 nm in the visible wavelength range using low applied voltages between −3.0 V and 2.8 V. The electrical potential is applied across the nanoscale gap causing changes in the gap thickness and dielectric environment which, in turn, modifies the plasmon resonance. The observed tuning range is greater than the full-width-at-half-maximum of the plasmon resonance, resulting in a tuning figure of merit of 1.05 and a tuning contrast greater than 50%. Our results provide an avenue to create active and reconfigurable integrated nanophotonic components for applications in optoelectronics and sensing.

Measurement of Beam Tunes in the Tevatron Using the BBQ System

Energy Technology Data Exchange (ETDEWEB)

Edstrom, Dean R.; /Indiana U.

2009-04-01

Measuring the betatron tunes in any synchrotron is of critical importance to ensuring the stability of beam in the synchrotron. The Base Band Tune, or BBQ, measurement system was developed by Marek Gasior of CERN and has been installed at Brookhaven and Fermilab as a part of the LHC Accelerator Research Program, or LARP. The BBQ was installed in the Tevatron to evaluate its effectiveness at reading proton and antiproton tunes at its flattop energy of 980 GeV. The primary objectives of this thesis are to examine the methods used to measure the tune using the BBQ tune measurement system, to incorporate the system into the Fermilab accelerator controls system, ACNET, and to compare the BBQ to existing tune measurement systems in the Tevatron.

Measurement of Beam Tunes in the Tevatron Using the BBQ System

International Nuclear Information System (INIS)

Edstrom, Dean R.

2009-01-01

Measuring the betatron tunes in any synchrotron is of critical importance to ensuring the stability of beam in the synchrotron. The Base Band Tune, or BBQ, measurement system was developed by Marek Gasior of CERN and has been installed at Brookhaven and Fermilab as a part of the LHC Accelerator Research Program, or LARP. The BBQ was installed in the Tevatron to evaluate its effectiveness at reading proton and antiproton tunes at its flattop energy of 980 GeV. The primary objectives of this thesis are to examine the methods used to measure the tune using the BBQ tune measurement system, to incorporate the system into the Fermilab accelerator controls system, ACNET, and to compare the BBQ to existing tune measurement systems in the Tevatron

An efficient automated parameter tuning framework for spiking neural networks.

Science.gov (United States)

Carlson, Kristofor D; Nageswaran, Jayram Moorkanikara; Dutt, Nikil; Krichmar, Jeffrey L

2014-01-01

As the desire for biologically realistic spiking neural networks (SNNs) increases, tuning the enormous number of open parameters in these models becomes a difficult challenge. SNNs have been used to successfully model complex neural circuits that explore various neural phenomena such as neural plasticity, vision systems, auditory systems, neural oscillations, and many other important topics of neural function. Additionally, SNNs are particularly well-adapted to run on neuromorphic hardware that will support biological brain-scale architectures. Although the inclusion of realistic plasticity equations, neural dynamics, and recurrent topologies has increased the descriptive power of SNNs, it has also made the task of tuning these biologically realistic SNNs difficult. To meet this challenge, we present an automated parameter tuning framework capable of tuning SNNs quickly and efficiently using evolutionary algorithms (EA) and inexpensive, readily accessible graphics processing units (GPUs). A sample SNN with 4104 neurons was tuned to give V1 simple cell-like tuning curve responses and produce self-organizing receptive fields (SORFs) when presented with a random sequence of counterphase sinusoidal grating stimuli. A performance analysis comparing the GPU-accelerated implementation to a single-threaded central processing unit (CPU) implementation was carried out and showed a speedup of 65× of the GPU implementation over the CPU implementation, or 0.35 h per generation for GPU vs. 23.5 h per generation for CPU. Additionally, the parameter value solutions found in the tuned SNN were studied and found to be stable and repeatable. The automated parameter tuning framework presented here will be of use to both the computational neuroscience and neuromorphic engineering communities, making the process of constructing and tuning large-scale SNNs much quicker and easier.

Application of Evolutionary Computation in Automotive Powertrain Mount Tuning

Directory of Open Access Journals (Sweden)

Anab Akanda

2006-01-01

Full Text Available Engine mount tuning is a multi-disciplinary exercise since it affects Idle-shake, Road-shake and power-train noise response. Engine inertia is often used as a tuned absorber for controlling suspension resonance related road-shake issues. Last but not least, vehicle ride and handling may also be affected by mount tuning. In this work, Torque-Roll-Axis (TRA decoupling of the rigid powertrain was used as a starting point for mount tuning. Nodal point of flexible powertrain bending was used to define the envelop for transmission mount locations. The frequency corresponding to the decoupled roll mode of the rigid powertrain was then adjusted for idle-shake and road-shake response management.

Sahara Coal: the fine art of collecting fines for profit

Energy Technology Data Exchange (ETDEWEB)

Schreckengost, D.; Arnold, D.

1984-09-01

Because of a change in underground mining methods that caused a considerable increase in the amount of fine sizes in the raw coal, Sahara Coal Co. designed and constructed a unique and simple fine coal system at their Harrisburg, IL prep plant. Before the new system was built, the overload of the fine coal circuit created a cost crunch due to loss of salable coal to slurry ponds, slurry pond cleaning costs, and operating and maintenance costs--each and every one excessive. Motivated by these problems, Sahara designed a prototype system to dewater the minus 28 mesh refuse. The success of the idea permitted fine refuse to be loaded onto the coarse refuse belt. Sahara also realized a large reduction in pond cleaning costs. After a period of testing, an expanded version of the refuse system was installed to dewater and dry the 28 mesh X 0 clean coal. Clean coal output increased about 30 tph. Cost savings justified the expenditures for the refuse and clean coal systems. These benefits, combined with increased coal sales revenue, paid back the project costs in less than a year.

Dancing to a Different Tune: Adaptive Evolution Fine-Tunes Protein Dynamics

Science.gov (United States)

2015-09-01

efficiency at low temperatures when the enzymes from mesophilic bacteria were evolved to have stabilities as high as their thermophilic homologs. The work...wild-type enzyme . This unfolding temperature is relatively high for a non- thermophilic enzyme ,15 as mesophilic enzymes typically unfold below 60 °C...The work described in this thesis provides a case study exploring the molecular changes underlying adaptive evolution in a key allosteric enzyme . It

Improving Convergence of Iterative Feedback Tuning using Optimal External Perturbations

DEFF Research Database (Denmark)

Huusom, Jakob Kjøbsted; Hjalmarsson, Håkon; Poulsen, Niels Kjølstad

2008-01-01

Iterative feedback tuning constitutes an attractive control loop tuning method for processes in the absence of sufficient process insight. It is a purely data driven approach to optimization of the loop performance. The standard formulation ensures an unbiased estimate of the loop performance cost...... function gradient, which is used in a search algorithm. A slow rate of convergence of the tuning method is often experienced when tuning for disturbance rejection. This is due to a poor signal to noise ratio in the process data. A method is proposed for increasing the information content in data...

Evaluation of Controller Tuning Methods Applied to Distillation Column Control

DEFF Research Database (Denmark)

Nielsen, Kim; W. Andersen, Henrik; Kümmel, Professor Mogens

A frequency domain approach is used to compare the nominal performance and robustness of dual composition distillation column control tuned according to Ziegler-Nichols (ZN) and Biggest Log Modulus Tuning (BLT) for three binary distillation columns, WOBE, LUVI and TOFA. The scope of this is to ex......A frequency domain approach is used to compare the nominal performance and robustness of dual composition distillation column control tuned according to Ziegler-Nichols (ZN) and Biggest Log Modulus Tuning (BLT) for three binary distillation columns, WOBE, LUVI and TOFA. The scope...

Topological evolution and photoluminescent properties of a series of divalent zinc-based metal–organic frameworks tuned via ancillary ligating spacers

Energy Technology Data Exchange (ETDEWEB)

Lian, Xiao-Min; Zhao, Wen [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China); Zhao, Xiao-Li, E-mail: xlzhao@chem.ecnu.edu.cn [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China)

2013-04-15

The combination of divalent zinc ions, 4-(4-carboxybenzamido)benzoic acid and exo-bidendate bipyridine ligands gave rise to a series of new MOFs: [ZnL(bipy)]·DMF·H{sub 2}O (1), [ZnL(bpe)]·1.5H{sub 2}O (2), [ZnL(bpa)]·4H{sub 2}O (3) and [ZnL(bpp)]·1.75H{sub 2}O (4) (MOF=metal-organic framework, bipy=4,4′-bipyridine, bpe=trans-1,2-bis(4-pyridyl)ethylene, bpa=1,2-bis(4-pyridinyl)ethane, bpp=1,3-bis(4-pyridinyl)propane, H{sub 2}L=4,4′-(carbonylimino)dibenzoic acid). Fine tune over the topology of the MOFs was achieved via systematically varying the geometric length of the second ligating bipyridine ligands. Single-crystal X-ray analysis reveals that complex 1 has a triply interpenetrated three-dimensional (3D) framework with elongated primitive cubic topology, whereas isostructural complexes 2 and 3 each possesses a 6-fold interpenetrated diamondiod 3D framework. Further expansion of the length of the bipyridine ligand to bpp leads to the formation of 4, which features an interesting entangled architecture of 2D→3D parallel polycatenation. In addition, the thermogravimetric analyses and solid-state photoluminescent properties of the selected complexes are investigated. - Graphical abstract: The incorporation of exo-bidendate bipyridine spacers into the Zn–H{sub 2}L system has yielded a series of new MOFs exhibiting topological evolution from 3-fold interpenetration to 6-fold interpenetration and 2D→3D parallel polycatenation. Highlights: ► The effect of the pyridyl-based spacers on the formation of MOFs was explored. ► Fine tune over the topology of the MOFs was achieved. ► An interesting structure of 2D→3D parallel polycatenation is reported.

Topological evolution and photoluminescent properties of a series of divalent zinc-based metal–organic frameworks tuned via ancillary ligating spacers

International Nuclear Information System (INIS)

Lian, Xiao-Min; Zhao, Wen; Zhao, Xiao-Li

2013-01-01

The combination of divalent zinc ions, 4-(4-carboxybenzamido)benzoic acid and exo-bidendate bipyridine ligands gave rise to a series of new MOFs: [ZnL(bipy)]·DMF·H 2 O (1), [ZnL(bpe)]·1.5H 2 O (2), [ZnL(bpa)]·4H 2 O (3) and [ZnL(bpp)]·1.75H 2 O (4) (MOF=metal-organic framework, bipy=4,4′-bipyridine, bpe=trans-1,2-bis(4-pyridyl)ethylene, bpa=1,2-bis(4-pyridinyl)ethane, bpp=1,3-bis(4-pyridinyl)propane, H 2 L=4,4′-(carbonylimino)dibenzoic acid). Fine tune over the topology of the MOFs was achieved via systematically varying the geometric length of the second ligating bipyridine ligands. Single-crystal X-ray analysis reveals that complex 1 has a triply interpenetrated three-dimensional (3D) framework with elongated primitive cubic topology, whereas isostructural complexes 2 and 3 each possesses a 6-fold interpenetrated diamondiod 3D framework. Further expansion of the length of the bipyridine ligand to bpp leads to the formation of 4, which features an interesting entangled architecture of 2D→3D parallel polycatenation. In addition, the thermogravimetric analyses and solid-state photoluminescent properties of the selected complexes are investigated. - Graphical abstract: The incorporation of exo-bidendate bipyridine spacers into the Zn–H 2 L system has yielded a series of new MOFs exhibiting topological evolution from 3-fold interpenetration to 6-fold interpenetration and 2D→3D parallel polycatenation. Highlights: ► The effect of the pyridyl-based spacers on the formation of MOFs was explored. ► Fine tune over the topology of the MOFs was achieved. ► An interesting structure of 2D→3D parallel polycatenation is reported

Tuning of PID load frequency controller for power systems

International Nuclear Information System (INIS)

Tan Wen

2009-01-01

PID tuning of load frequency controllers for power systems is discussed in this paper. The tuning method is based on a two-degree-of-freedom internal model control (IMC) design method, and the performance of the resulting PID controller is related to two tuning parameters thus detuning is easy when necessary. Then an anti-GRC scheme is proposed to overcome the generation rate constraints. Finally, the method is extended to two-area cases.

Assessment of arrays of in-stream tidal turbines in the Bay of Fundy.

Science.gov (United States)

Karsten, Richard; Swan, Amanda; Culina, Joel

2013-02-28

Theories of in-stream turbines are adapted to analyse the potential electricity generation and impact of turbine arrays deployed in Minas Passage, Bay of Fundy. Linear momentum actuator disc theory (LMADT) is combined with a theory that calculates the flux through the passage to determine both the turbine power and the impact of rows of turbine fences. For realistically small blockage ratios, the theory predicts that extracting 2000-2500 MW of turbine power will result in a reduction in the flow of less than 5 per cent. The theory also suggests that there is little reason to tune the turbines if the blockage ratio remains small. A turbine array model is derived that extends LMADT by using the velocity field from a numerical simulation of the flow through Minas Passage and modelling the turbine wakes. The model calculates the resulting speed of the flow through and around a turbine array, allowing for the sequential positioning of turbines in regions of strongest flow. The model estimates that over 2000 MW of power is possible with only a 2.5 per cent reduction in the flow. If turbines are restricted to depths less than 50 m, the potential power generation is reduced substantially, down to 300 MW. For large turbine arrays, the blockage ratios remain small and the turbines can produce maximum power with a drag coefficient equal to the Betz-limit value.

A Tuned Single Parameter for Representing Conjunction Risk

Science.gov (United States)

Plakaloic, D.; Hejduk, M. D.; Frigm, R. C.; Newman, L. K.

2011-01-01

Satellite conjunction assessment risk analysis is a subjective enterprise that can benefit from quantitative aids and, to this end, NASA/GSFC has developed a fuzzy logic construct - called the F-value - to attempt to provide a statement of conjunction risk that amalgamates multiple indices and yields a more stable intra-event assessment. This construct has now sustained an extended tuning procedure against heuristic analyst assessment of event risk. The tuning effort has resulted in modifications to the calculation procedure and the adjustment of tuning coefficients, producing a construct with both more predictive force and a better statement of its error.

Utilization of Short-Simulations for Tuning High-Resolution Climate Model

Science.gov (United States)

Lin, W.; Xie, S.; Ma, P. L.; Rasch, P. J.; Qian, Y.; Wan, H.; Ma, H. Y.; Klein, S. A.

2016-12-01

Many physical parameterizations in atmospheric models are sensitive to resolution. Tuning the models that involve a multitude of parameters at high resolution is computationally expensive, particularly when relying primarily on multi-year simulations. This work describes a complementary set of strategies for tuning high-resolution atmospheric models, using ensembles of short simulations to reduce the computational cost and elapsed time. Specifically, we utilize the hindcast approach developed through the DOE Cloud Associated Parameterization Testbed (CAPT) project for high-resolution model tuning, which is guided by a combination of short (tests have been found to be effective in numerous previous studies in identifying model biases due to parameterized fast physics, and we demonstrate that it is also useful for tuning. After the most egregious errors are addressed through an initial "rough" tuning phase, longer simulations are performed to "hone in" on model features that evolve over longer timescales. We explore these strategies to tune the DOE ACME (Accelerated Climate Modeling for Energy) model. For the ACME model at 0.25° resolution, it is confirmed that, given the same parameters, major biases in global mean statistics and many spatial features are consistent between Atmospheric Model Intercomparison Project (AMIP)-type simulations and CAPT-type hindcasts, with just a small number of short-term simulations for the latter over the corresponding season. The use of CAPT hindcasts to find parameter choice for the reduction of large model biases dramatically improves the turnaround time for the tuning at high resolution. Improvement seen in CAPT hindcasts generally translates to improved AMIP-type simulations. An iterative CAPT-AMIP tuning approach is therefore adopted during each major tuning cycle, with the former to survey the likely responses and narrow the parameter space, and the latter to verify the results in climate context along with assessment in

Tune space manipulations in jumping depolarizing resonances

International Nuclear Information System (INIS)

Ratner, L.G.; Ahrens, L.A.

1987-01-01

In February 1986, the AGS polarized beam reached a momentum of 22 GeV/c with a 45% polarization and an intensity of 1 to 2 x 10 10 polarized protons per pulse at a repetition rate of 2.1 seconds. In order to achieve this, one had to overcome the effect of some 40 depolarizing resonances. In our first commissioning run in 1984, we had reached 16.5 GeV/c using, with suitable modifications, the conventional techniques first used at the Argonne ZGS. This worked well, but we found that the fast tune shifts required to cross the intrinsic depolarizing resonances were causing an increase in beam emittance which led to the need for stronger corrections later in the cycle and to diminished extraction efficiency. For the 1986 run, we were prepared to minimize this emittance growth by the application of slow quadrupole pulses to change the region in tune space in which we operated the first tune quads. In this paper we give a brief description of the conventional corrections, but our main emphasis is on the descriptions of tune space manipulations

A novel tuning approach for offset-free MPC

DEFF Research Database (Denmark)

Waschl, Harald; Jørgensen, John Bagterp; Huusom, Jakob Kjøbsted

2015-01-01

, if a nominal plant and overall objective are known, the tuning can become straightforward. However, as soon as disturbances have to be taken into account, the tuning effort increases and becomes less intuitive. Against this background, a novel strategy to address the issues with unknown disturbances...

Accurate automatic tuning circuit for bipolar integrated filters

NARCIS (Netherlands)

de Heij, Wim J.A.; de Heij, W.J.A.; Hoen, Klaas; Hoen, Klaas; Seevinck, Evert; Seevinck, E.

1990-01-01

An accurate automatic tuning circuit for tuning the cutoff frequency and Q-factor of high-frequency bipolar filters is presented. The circuit is based on a voltage controlled quadrature oscillator (VCO). The frequency and the RMS (root mean square) amplitude of the oscillator output signal are

Attention to Color Sharpens Neural Population Tuning via Feedback Processing in the Human Visual Cortex Hierarchy.

Science.gov (United States)

Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

2017-10-25

Attention can facilitate the selection of elementary object features such as color, orientation, or motion. This is referred to as feature-based attention and it is commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. Although gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex. We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target. SIGNIFICANCE STATEMENT Whether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life, we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse to fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time by attenuating the

Automatic Tuning of Control Parameters for Single Speed Engines

OpenAIRE

Olsson, Johan

2004-01-01

In Scania’s single speed engines for industrial and marine use, the engine speed is controlled by a PI-controller. This controller is tuned independent of engine type and application. This brings certain disadvantages since the engines are used in a wide range of applications where the dynamics may differ. In this thesis, the possibility to tune the controller automatically for a specific engine installation has been investigated. The work shows that automatic tuning is possible. By performin...

Neural Tuning Functions Underlie Both Generalization and Interference.

Directory of Open Access Journals (Sweden)

Ian S Howard

Full Text Available In sports, the role of backswing is considered critical for generating a good shot, even though it plays no direct role in hitting the ball. We recently demonstrated the scientific basis of this phenomenon by showing that immediate past movement affects the learning and recall of motor memories. This effect occurred regardless of whether the past contextual movement was performed actively, passively, or shown visually. In force field studies, it has been shown that motor memories generalize locally and that the level of compensation decays as a function of movement angle away from the trained movement. Here we examine if the contextual effect of past movement exhibits similar patterns of generalization and whether it can explain behavior seen in interference studies. Using a single force-field learning task, the directional tuning curves of both the prior contextual movement and the subsequent force field adaptive movements were measured. The adaptation movement direction showed strong directional tuning, decaying to zero by 90° relative to the training direction. The contextual movement direction exhibited a similar directional tuning, although the effect was always above 60%. We then investigated the directional tuning of the passive contextual movement using interference tasks, where the contextual movements that uniquely specified the force field direction were separated by ±15° or ±45°. Both groups showed a pronounced tuning effect, which could be well explained by the directional tuning functions for single force fields. Our results show that contextual effect of past movement influences predictive force compensation, even when adaptation does not require contextual information. However, when such past movement contextual information is crucial to the task, such as in an interference study, it plays a strong role in motor memory learning and recall. This work demonstrates that similar tuning responses underlie both generalization of

Required accuracy of tune measurement and parametrization of chromaticity control

International Nuclear Information System (INIS)

Maas, R.

1991-02-01

The betatron tunes v x and v y will be measured by Fourier-analyzing a BPM signal generated by a beam which received a fast ( kick /f rev ) equals the fractional part of the tune, a beam blow-up can be observed. In this note the required accuracy of such a tune measurement is discussed. (author). 6 schemes

Performance-based parameter tuning method of model-driven PID control systems.

Science.gov (United States)

Zhao, Y M; Xie, W F; Tu, X W

2012-05-01

In this paper, performance-based parameter tuning method of model-driven Two-Degree-of-Freedom PID (MD TDOF PID) control system has been proposed to enhance the control performances of a process. Known for its ability of stabilizing the unstable processes, fast tracking to the change of set points and rejecting disturbance, the MD TDOF PID has gained research interest recently. The tuning methods for the reported MD TDOF PID are based on internal model control (IMC) method instead of optimizing the performance indices. In this paper, an Integral of Time Absolute Error (ITAE) zero-position-error optimal tuning and noise effect minimizing method is proposed for tuning two parameters in MD TDOF PID control system to achieve the desired regulating and disturbance rejection performance. The comparison with Two-Degree-of-Freedom control scheme by modified smith predictor (TDOF CS MSP) and the designed MD TDOF PID tuned by the IMC tuning method demonstrates the effectiveness of the proposed tuning method. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

Tune measurements with high intensity ion beams at GSI SIS-18

Energy Technology Data Exchange (ETDEWEB)

Singh, Rahul [GSI, Darmstadt (Germany); TEMF, TU Darmstadt (Germany); Forck, Peter; Kowina, Piotr; Kaufmann, Wolfgang [GSI, Darmstadt (Germany); Weiland, Thomas [TEMF, TU Darmstadt (Germany)

2012-07-01

A precise tune measurement during a full accelerating cycle is required to achieve stable high current operation. A new system has been commissioned at GSI for position, orbit and tune measurements. It consists of three distinct parts; an exciter which provides power to excite coherent betatron oscillations in the bunched beam; Fast ADCs to digitize the BPM signals at 125 MSa/s; the post processing electronics uses digitized BPM signals to acquire one position value per bunch. Subsequently the baseband tune is determined by Fourier transformation of the position data. Experiments were conducted to understand the effects of high beam intensity on tune at injection plateau (11.4 MeV/u) and during acceleration ramp (11.4-600 MeV/u). These experiments were performed with U{sup 73+} and Ar{sup 18+} ion beam at highest achievable intensities of 2.10{sup 9} and 2.5.10{sup 10} respectively. Tune shift with increased intensity was observed. The working principle of the tune measurement system and observed high intensity effects on tune will be reported in this contribution.

Self-Tuning Speed Regulator for CVC Induction Motor Drive

DEFF Research Database (Denmark)

Bidstrup, N.; Rasmussen, Henrik; Knudsen, Torben

1994-01-01

A self-tuning speed regulator for a current vector controlled induction motor drive has been designed.......A self-tuning speed regulator for a current vector controlled induction motor drive has been designed....

Tune modulation due to synchrotron oscillations and chromaticity, and the dynamic aperture

International Nuclear Information System (INIS)

Parzen, G.

1995-01-01

A tracking study was done of the effects of a tune modulations, due to synchrotron oscillations and the tune dependence on momentum (chromaticity), on the dynamic aperture. The studies were done using several RHIC lattices and tracking runs of about 1 x 10 6 turns. The dynamic aperture was found to decrease roughly linearly with the amplitude of the tune modulation. Lower order non-linear resonances, like the 1/3 and 1/4 resonance are not crossed because of the tune modulation. Three different cases were studied, corresponding to RHIC lattices with different β*, and with different synchrotron oscillation amplitudes. In each case, the tune modulation amplitude was varied by changing the chromaticity. In each case, roughly the same result, was found. The result found here for the effect of a tune modulation due to chromaticity may be compared with the result found for the effect of a tune modulation due to a gradient ripple in the quadrupoles. The effect of a tune modulation due to a gradient ripple appears to be about 4 times stronger than the effect of a tune modulation due to chromaticity and synchrotron oscillations

Tuned sources of submillimetre radiation

International Nuclear Information System (INIS)

Berezhnyj, V.L.

1981-01-01

The main present directions of development of sources of frequency coherent tuned radiation of electromagnetic waves in the submillimeter range: nonlinear mixing of different frequencies; semiconductor lasers; molecular lasers with optical pumping; relativistic electron beams in a magnetic field as submillimeter radiation sources; submillimeter radiation sources on the basis of SHF classical electrovacuum devices - are considered. The designs of generator systems and their specifications are presented. The main parameters of electromagnetic radiation of different sources, such as: power, stability, frequency, tuning range - are presented. The methods of improving sources and electromagnetic radiation parameters are proposed. The examples of possible applications of submillimeter radiation in different spheres of science and technology are given [ru

Customized binary and multi-level HfO2-x-based memristors tuned by oxidation conditions.

Science.gov (United States)

He, Weifan; Sun, Huajun; Zhou, Yaxiong; Lu, Ke; Xue, Kanhao; Miao, Xiangshui

2017-08-30

The memristor is a promising candidate for the next generation non-volatile memory, especially based on HfO 2-x , given its compatibility with advanced CMOS technologies. Although various resistive transitions were reported independently, customized binary and multi-level memristors in unified HfO 2-x material have not been studied. Here we report Pt/HfO 2-x /Ti memristors with double memristive modes, forming-free and low operation voltage, which were tuned by oxidation conditions of HfO 2-x films. As O/Hf ratios of HfO 2-x films increase, the forming voltages, SET voltages, and R off /R on windows increase regularly while their resistive transitions undergo from gradually to sharply in I/V sweep. Two memristors with typical resistive transitions were studied to customize binary and multi-level memristive modes, respectively. For binary mode, high-speed switching with 10 3 pulses (10 ns) and retention test at 85 °C (>10 4 s) were achieved. For multi-level mode, the 12-levels stable resistance states were confirmed by ongoing multi-window switching (ranging from 10 ns to 1 μs and completing 10 cycles of each pulse). Our customized binary and multi-level HfO 2-x -based memristors show high-speed switching, multi-level storage and excellent stability, which can be separately applied to logic computing and neuromorphic computing, further suitable for in-memory computing chip when deposition atmosphere may be fine-tuned.

Driving the Power of AIX Performance Tuning on IBM Power

CERN Document Server

Milberg, Ken

2009-01-01

A concise reference for IT professionals, this book goes beyond the rules and contains the best practices and strategies for solid tuning methodology. Tips based on years of experience from an AIX tuning master show specific steps for monitoring and tuning CPU, virtual memory, disk I/O, and network components. Also offering techniques for tuning Oracle and Linux structures that run on an IBM power system-as well as for the new AIX 6.1-this manual discusses what tools are available, how to best use them to collect historical data, and when to analyze trends and results. The only comprehensive,

Historic Learning Approach for Auto-tuning OpenACC Accelerated Scientific Applications

KAUST Repository

Siddiqui, Shahzeb

2015-04-17

The performance optimization of scientific applications usually requires an in-depth knowledge of the hardware and software. A performance tuning mechanism is suggested to automatically tune OpenACC parameters to adapt to the execution environment on a given system. A historic learning based methodology is suggested to prune the parameter search space for a more efficient auto-tuning process. This approach is applied to tune the OpenACC gang and vector clauses for a better mapping of the compute kernels onto the underlying architecture. Our experiments show a significant performance improvement against the default compiler parameters and drastic reduction in tuning time compared to a brute force search-based approach.

Cellular prion protein is required for neuritogenesis: fine-tuning of multiple signaling pathways involved in focal adhesions and actin cytoskeleton dynamics

Directory of Open Access Journals (Sweden)

Alleaume-Butaux A

2013-07-01

Full Text Available Aurélie Alleaume-Butaux,1,2 Caroline Dakowski,1,2 Mathéa Pietri,1,2 Sophie Mouillet-Richard,1,2 Jean-Marie Launay,3,4 Odile Kellermann,1,2 Benoit Schneider1,2 1INSERM, UMR-S 747, 2Paris Descartes University, Sorbonne Paris Cité, UMR-S 747, 3Public Hospital of Paris, Department of Biochemistry, INSERM UMR-S 942, Lariboisière Hospital, Paris, France; 4Pharma Research Department, Hoffmann La Roche Ltd, Basel, Switzerland Abstract: Neuritogenesis is a dynamic phenomenon associated with neuronal differentiation that allows a rather spherical neuronal stem cell to develop dendrites and axon, a prerequisite for the integration and transmission of signals. The acquisition of neuronal polarity occurs in three steps: (1 neurite sprouting, which consists of the formation of buds emerging from the postmitotic neuronal soma; (2 neurite outgrowth, which represents the conversion of buds into neurites, their elongation and evolution into axon or dendrites; and (3 the stability and plasticity of neuronal polarity. In neuronal stem cells, remodeling and activation of focal adhesions (FAs associated with deep modifications of the actin cytoskeleton is a prerequisite for neurite sprouting and subsequent neurite outgrowth. A multiple set of growth factors and interactors located in the extracellular matrix and the plasma membrane orchestrate neuritogenesis by acting on intracellular signaling effectors, notably small G proteins such as RhoA, Rac, and Cdc42, which are involved in actin turnover and the dynamics of FAs. The cellular prion protein (PrPC, a glycosylphosphatidylinositol (GPI-anchored membrane protein mainly known for its role in a group of fatal neurodegenerative diseases, has emerged as a central player in neuritogenesis. Here, we review the contribution of PrPC to neuronal polarization and detail the current knowledge on the signaling pathways fine-tuned by PrPC to promote neurite sprouting, outgrowth, and maintenance. We emphasize that Pr

Acclimation of fine root respiration to soil warming involves starch deposition in very fine and fine roots: a case study in Fagus sylvatica saplings.

Science.gov (United States)

Di Iorio, Antonino; Giacomuzzi, Valentino; Chiatante, Donato

2016-03-01

Root activities in terms of respiration and non-structural carbohydrates (NSC) storage and mobilization have been suggested as major physiological roles in fine root lifespan. As more frequent heat waves and drought periods within the next decades are expected, to what extent does thermal acclimation in fine roots represent a mechanism to cope with such upcoming climatic conditions? In this study, the possible changes in very fine (diameter respiration rate and NSC [soluble sugars (SS) and starch] concentrations, were investigated on 2-year-old Fagus sylvatica saplings subjected to a simulated long-lasting heat wave event and to co-occurring soil drying. For both very fine and fine roots, soil temperature (ST) resulted inversely correlated with specific root length, respiration rates and SSs concentration, but directly correlated with root mass, root tissue density and starch concentration. In particular, starch concentration increased under 28 °C for successively decreasing under 21 °C ST. These findings showed that thermal acclimation in very fine and fine roots due to 24 days exposure to high ST (∼ 28 °C), induced starch accumulation. Such 'carbon-savings strategy' should bear the maintenance costs associated to the recovery process in case of restored favorable environmental conditions, such as those occurring at the end of a heat wave event. Drought condition seems to affect the fine root vitality much more under moderate than high temperature condition, making the temporary exposure to high ST less threatening to root vitality than expected. © 2015 Scandinavian Plant Physiology Society.

Focal plane array based infrared thermography in fine physical experiment

International Nuclear Information System (INIS)

Vainer, Boris G

2008-01-01

By two examples of dissimilar physical phenomena causing thermophysical effects, the unique capabilities of one of the up-to-date methods of experimental physics-focal plane array (FPA) based infrared (IR) thermography (IRT), are demonstrated distinctly. Experimenters inexperienced in IRT can grasp how this method provides a means for combining real-time visualization with quantitative analysis. A narrow-band short-wavelength IR camera was used in the experiments. It is discussed and stated that IRT is best matched and suited to the next two test conditions-when a heated specimen is thin and when heat is generated in the immediate region of a surface of a solid. The first prerequisite is realized in the search for directional patterns of combined low-power radiation sources with the use of the IRT-aided method. The second one is realized in studies of water vapour adsorption on uneven (irregular) surfaces of solid materials. With multiple swatches taken from a set of different fabrics and used as experimental samples, a sharp distinction between adsorptivities of their surfaces is strikingly illustrated by IRT time-domain measurements exhibiting the associated thermal effect ranging within an order of magnitude. It is justified that the described IRT-aided test can find practical implementation at least in the light industry. Emissivities of different fabrics are evaluated experimentally with the described reflection method based on the narrow spectral range of IRT. On the basis of direct IR observations, attention is paid to the need for close control over the surface temperature increase while the adsorption isotherms are being measured. Sensitivity of the FPA-based IRT method, as applied to examine the kinetics of initial stages of adsorption of gaseous molecules on the solid surface, is evaluated analytically and quantitatively. The relationship between the amount of adsorbate and the measurable excess of adsorbent temperature is found. It is discovered that

Focal plane array with modular pixel array components for scalability

Science.gov (United States)

Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

2014-12-09

A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

[Laser Tuning Performance Testing and Optimization in TDLAS Oxygen Measuring Systems].

Science.gov (United States)

He, Jun-feng; Hu, Jun; Kan, Rui-feng; Xu, Zhen-yu; Wang, Tao

2015-03-01

TDLAS (tunable diode laser absorption spectroscopy) technology, with its unmatched advantages such as high selectivity molecular spectra, fast response, high sensitivity, non-contact measuring, become the preferred scheme for combustion process diagnosis, and can be effectively used for oxygen measuring. DFB (distributed feedback) laser diode with its small size, low power consumption, long service life, narrow linewidth, tunable wavelength has become the main choice of the TDLAS system. Performance of laser tuning characteristics is a key factor restricting TDLAS's measuring performance. According to TDLAS oxygen measuring system's working requirements, a simple experimental method was used to test and analyze tuning characteristics such as wavelength current, power current and wavelength temperature of a 764 nm DFB laser diode in the system. Nonlinear distortion of tuning curves was obvious, which affects oxygen measuring accuracy. The laser spectra's characteristics such as narrow linewidth, high side mode suppression ratio and wide wavelength tuning range are obvious, while its wavelength-current tuning curve with a tuning rate of about 0.023 nm x mA(-1) is not strictly linear. The higher the temperature the greater the threshold current, the PI curve is not strictly linear either. Temperature tuning curve is of good linearity, temperature-wave-length tuning rate keeps constant of about 0.056 nm/DEG C. Temperature tuning nonlinearity can be improved by high temperature control accuracy, and current power nonlinearity can be improved by setting the reference light path. In order to solve the wavelength current tuning nonlinear problems, the method of DA controlling injection current was considered to compensate for non-linear wavelength current tuning according to DFB laser diode tuning mechanism and polynomial fitting of test results. In view of different type of lasers, this method needs only one polynomial fitting process before the system's initial work. The

Timed arrays wideband and time varying antenna arrays

CERN Document Server

Haupt, Randy L

2015-01-01

Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

Naturalness Reach of the Large Hadron Collider in Minimal Supergravity

CERN Document Server

Allanach, B.C.; Parker, Michael Andrew; Webber, B.R.

2000-01-01

We re-analyse the prospects of discovering supersymmetry at the LHC, in order to re-express coverage in terms of a fine-tuning parameter and to extend the analysis to scalar masses (m_0) above 2 TeV. We use minimal supergravity (mSUGRA) unification assumptions for the SUSY breaking parameters. Such high values of m_0 have recently been found to have a focus point, leading to relatively low fine-tuning. In addition, improvements in the simulations since the last study mean that this region no longer lacks radiative electroweak symmetry breaking. The best fine tuning reach is found in a mono-leptonic channel, where for mu>0, A_0=0 and tan beta=10 (corresponding to the focus point), all points in mSUGRA with m_0 < 4000 GeV, with a fine tuning measure up to 300 (570) are covered by the search, where the definition of fine-tuning excludes (includes) the contribution from the top Yukawa coupling. Even for arbitrarily high m_0, mSUGRA does not evade detection provided the gaugino mass parameter M_{1/2} < 460 G...

Double-tuned radiofrequency coil for (19)F and (1)H imaging.

Science.gov (United States)

Otake, Yosuke; Soutome, Yoshihisa; Hirata, Koji; Ochi, Hisaaki; Bito, Yoshitaka

2014-01-01

We developed a double-tuned radiofrequency (RF) coil using a novel circuit method to double tune for fluorine-19 (19F) and 1H magnetic resonance imaging, whose frequencies are very close to each other. The RF coil consists of 3 parallel-connected series inductor capacitor circuits. A computer simulation for our double-tuned RF coil with a phantom demonstrated that the coil has tuned resonant frequency and high sensitivity for both 19F and 1H. Drug distribution was visualized at 7 tesla using this RF coil and a rat administered perfluoro 15-crown-5-ether emulsion. The double-tune RF coil we developed may be a powerful tool for 19F and 1H imaging.

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT VII, ENGINE TUNE-UP--DETROIT DIESEL ENGINE.

Science.gov (United States)

Human Engineering Inst., Cleveland, OH.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF TUNE-UP PROCEDURES FOR DIESEL ENGINES. TOPICS ARE SCHEDULING TUNE-UPS, AND TUNE-UP PROCEDURES. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM "ENGINE TUNE-UP--DETROIT DIESEL ENGINE" AND OTHER MATERIALS. SEE VT 005 655 FOR FURTHER INFORMATION.…

High-Q perpendicular-biased ferrite-tuned cavity

International Nuclear Information System (INIS)

Carlini, R.D.; Thiessen, H.A.; Potter, J.M.

1983-01-01

Rapid-cycling proton synchrotrons, such as the proposed LAMPF II accelerator, require approximately 10 MV per turn rf with 17% tuning range near 50 MHz. The traditional approach to ferrite-tuned cavities uses a ferrite which is longitudinally biased (rf magnetic field parallel to bias field). This method leads to unacceptably high losses in the ferrite. At Los Alamos, we are developing a cavity with transverse bias (rf magnetic field perpendicular to the bias field) that makes use of the tensor permeability of the ferrite. Modest power tests of a small (10-cm-dia) quarter-wave singly re-entrant cavity tuned by nickel-zinc ferrites and aluminum-doped garnets indicate that the losses in the ferrite can be made negligible compared with the losses due to the surface resistivity of the copper cavity at power levels from 2 to 200 watts

Tune measurement in the NSLS booster synchrotron

International Nuclear Information System (INIS)

Blum, E.B.; Nawrocky, R.

1993-01-01

The NSLS booster synchrotron can accelerate an electron beam from approximately 80 to 750 MeV in 0.7 sec. The betatron tunes can change during acceleration by as much as 0.1 units, causing beam loss as they cross resonance lines. Precise measurements with a conventional swept spectrum analyzer have always been difficult because of the rapid variation of tune as the magnets are ramped. We are now using a system based on a Tektronix 3052 digital spectrum analyzer that can obtain a complete frequency spectrum over a 10 MHz bandwidth in 200 μsec. Betatron oscillations are stimulated for the measurements by applying white noise to the beam through stripline electrodes. We will describe the instrumentation, our measurements of tune as a function time during the acceleration cycle, and the resulting improvements to the booster operation

Application of digital beam position processor Libera on tune measurement

International Nuclear Information System (INIS)

Zhang Chunhui; Sun Baogen; Cao Yong; Lu Ping; Li Jihao

2006-01-01

Digital signal processing (DSP) is widely used in the field of beam diagnostics. Especially, DSP achieves very good performance in beam position signal analysis and betatron tune measurement. In Hefei light source, when beam was excited by narrow-band Gaussian white nose, Libera, a digital beam position processor, was used to process the signals from beam position monitor (BPM), which contained betatron oscillation. Fast Fourier transform (FFT) was applied to finding out betatron resonance frequency, from which the decimal part of betatron oscillation tune was calculated. By this means, the measure of horizontal tune was 3.5352 and the measure of vertical tune is 2.6299. (authors)

ArrayBridge: Interweaving declarative array processing with high-performance computing

Energy Technology Data Exchange (ETDEWEB)

Xing, Haoyuan [The Ohio State Univ., Columbus, OH (United States); Floratos, Sofoklis [The Ohio State Univ., Columbus, OH (United States); Blanas, Spyros [The Ohio State Univ., Columbus, OH (United States); Byna, Suren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prabhat, Prabhat [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Kesheng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Paul [Paradigm4, Inc., Waltham, MA (United States)

2017-05-04

Scientists are increasingly turning to datacenter-scale computers to produce and analyze massive arrays. Despite decades of database research that extols the virtues of declarative query processing, scientists still write, debug and parallelize imperative HPC kernels even for the most mundane queries. This impedance mismatch has been partly attributed to the cumbersome data loading process; in response, the database community has proposed in situ mechanisms to access data in scientific file formats. Scientists, however, desire more than a passive access method that reads arrays from files. This paper describes ArrayBridge, a bi-directional array view mechanism for scientific file formats, that aims to make declarative array manipulations interoperable with imperative file-centric analyses. Our prototype implementation of ArrayBridge uses HDF5 as the underlying array storage library and seamlessly integrates into the SciDB open-source array database system. In addition to fast querying over external array objects, ArrayBridge produces arrays in the HDF5 file format just as easily as it can read from it. ArrayBridge also supports time travel queries from imperative kernels through the unmodified HDF5 API, and automatically deduplicates between array versions for space efficiency. Our extensive performance evaluation in NERSC, a large-scale scientific computing facility, shows that ArrayBridge exhibits statistically indistinguishable performance and I/O scalability to the native SciDB storage engine.

Minimization of spin tune spread by matching dispersion prime at RHIC

Energy Technology Data Exchange (ETDEWEB)

Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kewisch, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-08-31

At RHIC, the spin polarization is preserved with a pair of Siberian snakes on the oppo- site sides in each ring. The polarized proton beam with finite spin tune spread might cross spin resonances multiple times in two cases, one is when beam going through strong spin intrinsic resonances during acceleration, the other is when sweeping spin flipper’ frequency across the spin tune to flip the direction of spin polarization. The consequence is loss of spin polarization in both cases. Therefore, a scheme of min- imizing the spin tune spread by matching the dispersion primes at the two snakes was introduced based on the fact that the spin tune spread is proportional to the difference of dispersion primes at the two snakes. The scheme was implemented at fixed energies for the spin flipper study and during beam acceleration for better spin polarization transmission efficiency. The effect of minimizing the spin tune spread by matching the dispersion primes was observed and confirmed experimentally. The principle of minimizing the spin tune spread by matching the dispersion primes, the impact on the beam optics, and the effect of a narrower spin tune spread are presented in this report.

Collective Mind: Towards Practical and Collaborative Auto-Tuning

Directory of Open Access Journals (Sweden)

Grigori Fursin

2014-01-01

Full Text Available Empirical auto-tuning and machine learning techniques have been showing high potential to improve execution time, power consumption, code size, reliability and other important metrics of various applications for more than two decades. However, they are still far from widespread production use due to lack of native support for auto-tuning in an ever changing and complex software and hardware stack, large and multi-dimensional optimization spaces, excessively long exploration times, and lack of unified mechanisms for preserving and sharing of optimization knowledge and research material. We present a possible collaborative approach to solve above problems using Collective Mind knowledge management system. In contrast with previous cTuning framework, this modular infrastructure allows to preserve and share through the Internet the whole auto-tuning setups with all related artifacts and their software and hardware dependencies besides just performance data. It also allows to gradually structure, systematize and describe all available research material including tools, benchmarks, data sets, search strategies and machine learning models. Researchers can take advantage of shared components and data with extensible meta-description to quickly and collaboratively validate and improve existing auto-tuning and benchmarking techniques or prototype new ones. The community can now gradually learn and improve complex behavior of all existing computer systems while exposing behavior anomalies or model mispredictions to an interdisciplinary community in a reproducible way for further analysis. We present several practical, collaborative and model-driven auto-tuning scenarios. We also decided to release all material at c-mind.org/repo to set up an example for a collaborative and reproducible research as well as our new publication model in computer engineering where experimental results are continuously shared and validated by the community.

Tuning Properties in Silver Clusters

KAUST Repository

Joshi, Chakra Prasad

2015-07-09

The properties of Ag nanoclusters are not as well understood as those of their more precious Au cousins. However, a recent surge in the exploration of strategies to tune the physicochemical characteristics of Ag clusters addresses this imbalance, leading to new insights into their optical, luminescence, crystal habit, metal-core, ligand-shell and environmental properties. In this Perspective, we provide an overview of the latest strategies along with a brief introduction of the theoretical framework necessary to understand the properties of silver nanoclusters and the basis for their tuning. The advances in cluster research and the future prospects presented in this Perspective will eventually guide the next large systematic study of nanoclusters, resulting in a single collection of data similar to the periodic table of elements.

Computation of undulator tuning curves

International Nuclear Information System (INIS)

Dejus, Roger J.

1997-01-01

Computer codes for fast computation of on-axis brilliance tuning curves and flux tuning curves have been developed. They are valid for an ideal device (regular planar device or a helical device) using the Bessel function formalism. The effects of the particle beam emittance and the beam energy spread on the spectrum are taken into account. The applicability of the codes and the importance of magnetic field errors of real insertion devices are addressed. The validity of the codes has been experimentally verified at the APS and observed discrepancies are in agreement with predicted reduction of intensities due to magnetic field errors. The codes are distributed as part of the graphical user interface XOP (X-ray OPtics utilities), which simplifies execution and viewing of the results

Tuning Properties in Silver Clusters

KAUST Repository

Joshi, Chakra Prasad; Bootharaju, Megalamane Siddaramappa; Bakr, Osman

2015-01-01

The properties of Ag nanoclusters are not as well understood as those of their more precious Au cousins. However, a recent surge in the exploration of strategies to tune the physicochemical characteristics of Ag clusters addresses this imbalance, leading to new insights into their optical, luminescence, crystal habit, metal-core, ligand-shell and environmental properties. In this Perspective, we provide an overview of the latest strategies along with a brief introduction of the theoretical framework necessary to understand the properties of silver nanoclusters and the basis for their tuning. The advances in cluster research and the future prospects presented in this Perspective will eventually guide the next large systematic study of nanoclusters, resulting in a single collection of data similar to the periodic table of elements.

Design of coated standing nanowire array solar cell performing beyond the planar efficiency limits

Energy Technology Data Exchange (ETDEWEB)

Zeng, Yang; Ye, Qinghao; Shen, Wenzhong, E-mail: wzshen@sjtu.edu.cn [Institute of Solar Energy, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)

2016-05-28

The single standing nanowire (SNW) solar cells have been proven to perform beyond the planar efficiency limits in both open-circuit voltage and internal quantum efficiency due to the built-in concentration and the shifting of the absorption front. However, the expandability of these nano-scale units to a macro-scale photovoltaic device remains unsolved. The main difficulty lies in the simultaneous preservation of an effective built-in concentration in each unit cell and a broadband high absorption capability of their array. Here, we have provided a detailed theoretical guideline for realizing a macro-scale solar cell that performs furthest beyond the planar limits. The key lies in a complementary design between the light-trapping of the single SNWs and that of the photonic crystal slab formed by the array. By tuning the hybrid HE modes of the SNWs through the thickness of a coaxial dielectric coating, the optimized coated SNW array can sustain an absorption rate over 97.5% for a period as large as 425 nm, which, together with the inherited carrier extraction advantage, leads to a cell efficiency increment of 30% over the planar limit. This work has demonstrated the viability of a large-size solar cell that performs beyond the planar limits.

Mutual capacitance of liquid conductors in deformable tactile sensing arrays

Energy Technology Data Exchange (ETDEWEB)

Li, Bin [Electrical and Computer Engineering Department, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Fontecchio, Adam K. [Electrical and Computer Engineering and Materials Science and Engineering Departments, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Visell, Yon [Electrical and Computer Engineering Department, Media Arts and Technology, California NanoSystems Institute, University of California, Santa Barbara, California 93106 (United States)

2016-01-04

Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.

Human face processing is tuned to sexual age preferences

DEFF Research Database (Denmark)

Ponseti, J; Granert, O; van Eimeren, T

2014-01-01

Human faces can motivate nurturing behaviour or sexual behaviour when adults see a child or an adult face, respectively. This suggests that face processing is tuned to detecting age cues of sexual maturity to stimulate the appropriate reproductive behaviour: either caretaking or mating....... In paedophilia, sexual attraction is directed to sexually immature children. Therefore, we hypothesized that brain networks that normally are tuned to mature faces of the preferred gender show an abnormal tuning to sexual immature faces in paedophilia. Here, we use functional magnetic resonance imaging (f......MRI) to test directly for the existence of a network which is tuned to face cues of sexual maturity. During fMRI, participants sexually attracted to either adults or children were exposed to various face images. In individuals attracted to adults, adult faces activated several brain regions significantly more...

Recommendations for the tuning of rare event probability estimators

International Nuclear Information System (INIS)

Balesdent, Mathieu; Morio, Jérôme; Marzat, Julien

2015-01-01

Being able to accurately estimate rare event probabilities is a challenging issue in order to improve the reliability of complex systems. Several powerful methods such as importance sampling, importance splitting or extreme value theory have been proposed in order to reduce the computational cost and to improve the accuracy of extreme probability estimation. However, the performance of these methods is highly correlated with the choice of tuning parameters, which are very difficult to determine. In order to highlight recommended tunings for such methods, an empirical campaign of automatic tuning on a set of representative test cases is conducted for splitting methods. It allows to provide a reduced set of tuning parameters that may lead to the reliable estimation of rare event probability for various problems. The relevance of the obtained result is assessed on a series of real-world aerospace problems

Visible Light Photoelectrochemical Properties of N-Doped TiO2 Nanorod Arrays from TiN

Directory of Open Access Journals (Sweden)

Zheng Xie

2013-01-01

Full Text Available N-doped TiO2 nanorod arrays (NRAs were prepared by annealing the TiN nanorod arrays (NRAs which were deposited by using oblique angle deposition (OAD technique. The TiN NRAs were annealed at 330°C for different times (5, 15, 30, 60, and 120 min. The band gaps of annealed TiN NRAs (i.e., N-doped TiO2 NRAs show a significant variance with annealing time, and can be controlled readily by varying annealing time. All of the N-doped TiO2 NRAs exhibit an enhancement in photocurrent intensity in visible light compared with that of pure TiO2 and TiN, and the one annealed for 15 min shows the maximum photocurrent intensity owning to the optimal N dopant concentration. The results show that the N-doped TiO2 NRAs, of which the band gap can be tuned easily, are a very promising material for application in photocatalysis.

Towards automatic parameter tuning of stream processing systems

KAUST Repository

Bilal, Muhammad

2017-09-27

Optimizing the performance of big-data streaming applications has become a daunting and time-consuming task: parameters may be tuned from a space of hundreds or even thousands of possible configurations. In this paper, we present a framework for automating parameter tuning for stream-processing systems. Our framework supports standard black-box optimization algorithms as well as a novel gray-box optimization algorithm. We demonstrate the multiple benefits of automated parameter tuning in optimizing three benchmark applications in Apache Storm. Our results show that a hill-climbing algorithm that uses a new heuristic sampling approach based on Latin Hypercube provides the best results. Our gray-box algorithm provides comparable results while being two to five times faster.

Tuning the DARHT Axis-II linear induction accelerator focusing

Energy Technology Data Exchange (ETDEWEB)

Ekdahl, Carl A. [Los Alamos National Laboratory

2012-04-24

Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an

Heavy vehicle pitch dynamics and suspension tuning

OpenAIRE

Cao, Dongpu; Rakheja, Subhash; Su, Chun-Yi

2008-01-01

The influence of suspension tuning of passenger cars on bounce and pitch ride performance has been explored in a number of studies, while only minimal efforts have been made for establishing similar rules for heavy vehicles. This study aims to explore pitch dynamics and suspension tunings of a two-axle heavy vehicle with unconnected suspension, which could also provide valuable information for heavy vehicles with coupled suspensions. Based on a generalised pitch-plane model of a two-axle heav...

Implementation through Innovation: A Literature-Based Analysis of the Tuning Project

Science.gov (United States)

Pálvölgyi, Krisztián

2017-01-01

Tuning Educational Structures in Europe is perhaps the most important higher education innovation platform nowadays. The main objective of the Tuning Project is to develop a tangible approach to implement the action lines of the Bologna Process; thus, implementation and innovation are closely linked in Tuning. However, during its development,…

Carotid chemoreceptors tune breathing via multipath routing: reticular chain and loop operations supported by parallel spike train correlations.

Science.gov (United States)

Morris, Kendall F; Nuding, Sarah C; Segers, Lauren S; Iceman, Kimberly E; O'Connor, Russell; Dean, Jay B; Ott, Mackenzie M; Alencar, Pierina A; Shuman, Dale; Horton, Kofi-Kermit; Taylor-Clark, Thomas E; Bolser, Donald C; Lindsey, Bruce G

2018-02-01

We tested the hypothesis that carotid chemoreceptors tune breathing through parallel circuit paths that target distinct elements of an inspiratory neuron chain in the ventral respiratory column (VRC). Microelectrode arrays were used to monitor neuronal spike trains simultaneously in the VRC, peri-nucleus tractus solitarius (p-NTS)-medial medulla, the dorsal parafacial region of the lateral tegmental field (FTL-pF), and medullary raphe nuclei together with phrenic nerve activity during selective stimulation of carotid chemoreceptors or transient hypoxia in 19 decerebrate, neuromuscularly blocked, and artificially ventilated cats. Of 994 neurons tested, 56% had a significant change in firing rate. A total of 33,422 cell pairs were evaluated for signs of functional interaction; 63% of chemoresponsive neurons were elements of at least one pair with correlational signatures indicative of paucisynaptic relationships. We detected evidence for postinspiratory neuron inhibition of rostral VRC I-Driver (pre-Bötzinger) neurons, an interaction predicted to modulate breathing frequency, and for reciprocal excitation between chemoresponsive p-NTS neurons and more downstream VRC inspiratory neurons for control of breathing depth. Chemoresponsive pericolumnar tonic expiratory neurons, proposed to amplify inspiratory drive by disinhibition, were correlationally linked to afferent and efferent "chains" of chemoresponsive neurons extending to all monitored regions. The chains included coordinated clusters of chemoresponsive FTL-pF neurons with functional links to widespread medullary sites involved in the control of breathing. The results support long-standing concepts on brain stem network architecture and a circuit model for peripheral chemoreceptor modulation of breathing with multiple circuit loops and chains tuned by tegmental field neurons with quasi-periodic discharge patterns. NEW & NOTEWORTHY We tested the long-standing hypothesis that carotid chemoreceptors tune the