Article discussing how MATE transporters facilitate vacuolar uptake of epicatechin 3'-O-glucoside for proanthocyanidin biosynthesis in Medicago truncatula and Arabidopsis.

This article discusses non-Markovian nonstationary completely positive open-quantum-system dynamics.

This article discusses complexity and synchronization in decision making and information transmission.

In multi physics computations, where a compressible fluid is coupled with a linearly elastic solid, it is standard to enforce continuity of the normal velocities and of the normal stresses at the interface between the fluid and the solid. In a numerical scheme, there are many ways that the velocity- and stress-continuity can be enforced in the discrete approximation. This paper performs a normal mode analysis to investigate the stability of different numerical interface conditions for a model problem approximated by upwind type of finite difference schemes. The analysis shows that depending on the ratio of densities between the solid and the fluid, some numerical interface conditions are stable up to the maximal CFL-limit, while other numerical interface conditions suffer from a severe reduction of the stable CFL-limit. The paper also presents a new interface condition, obtained as a simplified charcteristic boundary condition, that is proved to not suffer from any reduction of the stable CFL-limit. Numerical experiments in one space dimension show that the new interface condition is stable also for computations with the non-linear Euler equations of compressible fluid flow coupled with a linearly elastic solid.

Electron cooling was proposed to increase luminosity of the RHIC collider for heavy ion beam energies below 10 GeV/nucleon. Providing collisions at such energies, termed RHIC 'low-energy' operation, will help to answer one of the key questions in the field of QCD about existence and location of critical point on the QCD phase diagram. The electron cooling system should deliver electron beam of required good quality over energies of 0.9-5 MeV. Several approaches to provide such cooling were considered. The baseline approach was chosen and design work started. Here we describe the main features of the cooling system and its expected performance. We have started design work on a low-energy RHIC electron cooler which will operate with kinetic electron energy range 0.86-2.8 (4.9) MeV. Several approaches to an electron cooling system in this energy range are being investigated. At present, our preferred scheme is to transfer the Fermilab Pelletron to BNL after Tevatron shutdown, and to use it for DC non-magnetized cooling in RHIC. Such electron cooling system can significantly increase RHIC luminosities at low-energy operation.

Polyphenylcarbosilane as a novel preceramic polymer for SiC was synthesized from thermal rearrangement of polymethylphenylsilane around 350 C {approx} 430 C. Characterization of synthesized polyphenylcarbosilane was performed with {sup 29}Si, {sup 13}C, {sup 1}H NMR, FT-IR, TG, XRD, and GPC analysis. From FT-IR data, the band at 1035 cm{sup -1} was very strong and assigned to CH{sub 2} bending vibration in Si-CH{sub 2}-Si group, indicating the formation of the polyphenylcarbosilane. The average of the molecular weight (M{sub w}) of the polyphenylcarbosilane synthesized was 2,500 and easily dissolves in an organic solvent. TGA data indicates that polyphenylcarbosilane is thermally stable up to 400 C. However, the rapid weight loss occurs above 400 C due to the pyrolysis of polyphenylcarbosilane, and the diffraction peak of pyrolysis residue at 1200 C corresponds to the {beta}-SiC ceramic. The ceramic yield calculated from TGA is approximately 65%.

Engineered microorganisms are currently used for the production of food products, pharmaceuticals, ethanol fuel and more. Even so, the enormous potential of this technology has yet to be fully exploited. The need for sustainable sources of transportation fuels has generated a tremendous interest in technologies that enable biofuel production. Decades of work have produced a considerable knowledge-base for the physiology and pathway engineering of microbes, making microbial engineering an ideal strategy for producing biofuel. Although ethanol currently dominates the biofuel market, some of its inherent physical properties make it a less than ideal product. To highlight additional options, we review advances in microbial engineering for the production of other potential fuel molecules, using a variety of biosynthetic pathways.

We report our simulations on the profile of the electric field in semi insulating CdTe and CdZnTe with Au contacts under radiation flux. The type of the space charge and electric field distribution in the Au/CdTe/Au structure is at high fluxes result of a combined influence of charge formed due to band bending at the electrodes and from photo generated carriers, which are trapped at deep levels. Simultaneous solution of drift-diffusion and Poisson equations is used for the calculation. We show, that the space charge originating from trapped photo-carriers starts to dominate at fluxes 10{sup 15}-10{sup 16}cm{sup -2}s{sup -1}, when the influence of contacts starts to be negligible.

The barrier bucket RF system is successfully used on Recycler storage ring at Fermilab. The special program code ESME was used for numerical simulation of longitudinal phase space manipulations. This program helps optimizing the various regimes of operation in the Recycler and increasing the luminosity in the colliding experiments. Electron and stochastic cooling increases the phase space density in all degrees of freedom. In the case of a small phase space volume the intrabeam scattering introduces coupling between the transverse and longitudinal temperatures of the antiproton beam. For numerical simulations of the cooling processes at the Recycler, a new model of the barrier buckets was implemented in the BETACOOL code. The comparison between ESME and BETACOOL codes for a stationary and moving barrier buckets is presented. This article also includes an application of the barrier bucket numerical model for simulation of the luminosity distribution for RHIC colliding experiments. These simulations take into account the specific longitudinal distribution of the bunch and the vertex size of the detector.

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Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of {sup 208}Pb{sup 82+} ion operation in the LHC, with focus on the alice interaction region, and show that the expected heat load during nominal {sup 208}Pb{sup 82+} operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

We report a 100,000-fold increase in the conductance of individual CdSe nanorods when they are electrically contacted via direct solution phase growth of Au tips on the nanorod ends. Ensemble UV-Vis and X-Ray photoelectron spectroscopy indicate this enhancement does not result from alloying of the nanorod. Rather, low temperature tunneling and high temperature (250-400 K) thermionic emission across the junction at the Au contact reveal a 75percent lower interface barrier to conduction compared to a control sample. We correlate this barrier lowering with the electronic structure at the Au-CdSe interface. Our results emphasize the importance of nanocrystal surface structure for robust device performance and the advantage of this contact method.

We propose undertaking a demonstration experiment on suppressing spontaneous undulator radiation from an electron beam at BNL's Accelerator Test Facility (ATF). We describe the method, the proposed layout, and a possible schedule. There are several advantages in strongly suppressing shot noise in the electron beam, and the corresponding spontaneous radiation. The self-amplified spontaneous (SASE) emission originating from shot noise in the electron beam is the main source of noise in high-gain FEL amplifiers. It may negatively affect several HG FEL applications ranging from single- to multi-stage HGHG FELs. SASE saturation also imposes a fundamental hard limit on the gain of an FEL amplifier in a coherent electron-cooling scheme. A novel active method for suppressing shot noise in relativistic electron beams by many orders-of-magnitude was recently proposed. While theoretically such strong suppression appears feasible, the performance and applicability of this novel method must be evaluated experimentally. Several practical questions about the proposed noise suppressor, such as 3D effects and/or sensitivity to the e-beam parameters also require experimental clarification. To do this, we propose here a proof-of-principle experiment using elements of the VISA FEL at BNL's Accelerator Test Facility.

The on-line models for Relativistic Ion Collider (RHIC) and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What we discuss in this paper is our vision of the future of the on-line model environment for RHIC and the RHIC preinjectors. Although these on-line models are primarily used as Courant-Snyder parameter calculators using live machine settings, we envision expanding these environments to encompass many other problem domains.

High resolution beam position monitors (BPM) are an essential tool to achieve and reproduce a low vertical beam emittance at the KEK Accelerator Test Facility (ATF) damping ring. The ATF damping ring (DR) BPMs are currently upgraded with new high resolution read-out electronics. Based on analog and digital down-conversion techniques, the upgrade includes an automatic gain calibration system to correct for slow drift effects and ensure high reproducible beam position readings. The concept and its technical realization, as well as preliminary results of beam studies are presented.

Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most …

Several recent reports have identified the scientific requirements for a future soft X-ray light source [1, 2, 3, 4, 5], and a high-repetition-rate free-electron laser (FEL) facility responsive to them is being studied at Lawrence Berkeley National Laboratory (LBNL) [6]. The facility is based on a continuous-wave (CW) superconducting linear accelerator with beam supplied by a high-brightness, high-repetition-rate photocathode electron gun operating in CW mode, and on an array of FELs to which the accelerated beam is distributed, each operating at high repetition rate and with even pulse spacing. Dependent on the experimental requirements, the individualFELs may be configured for either self-amplified spontaneous emission (SASE), seeded highgain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG), or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format ranging from sub-femtoseconds to hundreds of femtoseconds. This new light source would serve a broad community of scientists in many areas of research, similar to existing utilization of storage ring based light sources. To reduce technical risks and constructioncosts, accelerator research, development, and design studies at LBNL target the most critical components and systems of the facility. We are developing a high-repetition-rate low-emittance electron gun, high quantum …

The High Voltage Converter Modulators (HVCMs) at the Spallation Neutron Source (SNS) have operated in excess of a combined 250,000 hours. Performance and reliability improvements to the HVCM are ongoing to increase modulator availability as accelerator system demands increase. There is a relatively large amount of energy storage in the HVCMs, {approx}180 kJ. This energy has the potential to dump into unsuppressed faults, cause damage, and increase the time to repair. The 'fusing switch' concept involves isolation of this stored energy from the location of the most common faults. This paper introduces this concept and its application to the HVCMs.

The first stars, forming at redshifts z > 15 in minihalos with M {approx} 10{sup 5-6} M{sub {circle_dot}} may leave behind remnant black holes, which could conceivably have been the 'seeds' for the supermassive black holes observed at z {approx}< 7. We study remnant black hole growth through accretion, including for the first time the radiation emitted due to accretion, with adaptive mesh refinement cosmological radiation-hydrodynamical simulations. The effects of photo-ionization and heating dramatically affect the large-scale inflow, resulting in negligible mass growth. We compare cases with accretion luminosity included and neglected to show that accretion radiation drastically changes the environment within 100 pc of the black hole, increasing gas temperatures by an order of magnitude. Gas densities are reduced and further star formation in the same minihalo is prevented for the two hundred million years we followed. Without radiative feedback included most seed black holes do not gain mass as efficiently as has been hoped for in previous theories, implying that black hole remnants of Pop III stars in minihalos are not likely to be miniquasars. Most importantly, however, our calculations demonstrate that if these black holes are indeed accreting close to the Bondi-Hoyle rate with ten percent radiative …

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An enhanced version of an algorithm to provide anomaly based intrusion detection alerts for cyber security state awareness is detailed. A unique aspect is the training of an error back-propagation neural network with intrusion detection rule features to provide a recognition basis. Network packet details are subsequently provided to the trained network to produce a classification. This leverages rule knowledge sets to produce classifications for anomaly based systems. Several test cases executed on ICMP protocol revealed a 60% identification rate of true positives. This rate matched the previous work, but 70% less memory was used and the run time was reduced to less than 1 second from 37 seconds.

Simulations of the x-ray free-electron laser (FEL) oscillator are presented that include transverse effects and realistic Bragg crystal properties with the two-dimensional code GINGER. In the present cases considered the radiation divergence is much narrower than the crystal acceptance, and the numerical algorithm can be simplified by ignoring the finite angular bandwidth of the crystal. In this regime GINGER shows that the saturated x-ray pulses have 109 photons and are nearly Fourier-limited with peak powers in excess of 1 MW. Wealso include preliminary results for a four-mirror cavity that can be tuned in wavelength over a few percent, with future plans to incorporate the full transverse response of the Bragg crystals into GINGER to more accurately model this tunable source.

We argue that the fermion masses and mixings are organized in a specific pattern. The approximately equal hierarchies between successive generations, the sizes of the mixing angles, the heaviness of just the top quark, and the approximate down-lepton equality can all be accommodated by many flavor models but can appear ad hoc. We present a simple, predictive mechanism to explain these patterns. All generations are treated democratically and the flavor symmetries are broken collectively by only two allowed couplings in flavor-space, a vector and matrix, with arbitrary {Omicron}(1) entries. Repeated use of these flavor symmetry breaking spurions radiatively generates the Yukawa couplings with a natural hierarchy. We demonstrate this idea with two models in a split supersymmetric grand unified framework, with minimal additional particle content at the unification scale. Although flavor is generated at the GUT scale, there are several potentially testable predictions. In our minimal model the usual prediction of exact b-{tau} unification is replaced by the SU(5) breaking relation m{sub {tau}}/m{sub b} = 3/2, in better agreement with observations. Other SU(5) breaking effects in the fermion masses can easily arise directly from the flavor model itself. The symmetry breaking that triggers the generation of flavor necessarily gives rise …

Thermopile pyranometers exhibit IR radiative losses that affect global and diffuse shortwave measurements made with first class thermopile based instruments. Pyrgeometers can be used to measure the sky temperature and are used to calculate the pyranometer?s IR radiative losses.