Winding Modes Research Articles

Solar wind modulation of the Martian ionosphere observed by Mars Global Surveyor

Abstract. Electron density profiles in the Martian ionosphere observed by the radio occultation experiment on board Mars Global Surveyor have been analyzed to determine if the densities are influenced by the solar wind. Evidence is presented that the altitude of the maximum ionospheric electron density shows a positive correlation to the energetic proton flux in the solar wind. The solar wind modulation of the Martian ionosphere can be attributed to heating of the neutral atmosphere by the solar wind energetic proton precipitation. The modulation is observed to be most prominent at high solar zenith angles. It is argued that this is consistent with the proposed modulation mechanism.

Radiative corrections in 5D and 6D expanding in winding modes

We compute radiative corrections in five and six dimensional field theories, using winding modes in mixed momentum-coordinate space. This method provides a simple way of finding UV divergencies, finite corrections and localized terms when the space is compactified on orbifolds. As an application we compute the finite piece of scalar masses, the logarithmic contributions to the couplings and the effect of localized parallel and perpendicular kinetic terms. We apply it to get a two loop effective potential that can stabilize large extra dimensions.

Freedom in electroweak symmetry breaking and mass matrix of fermions in dimensional deconstruction model

There exists a freedom in a class of four-dimensional electroweak theories proposed by Arkani-Hamed et al. relying on deconstruction and Coleman–Weinberg mechanism. The freedom comes from the winding modes of the link variable (Wilson operator) connecting non-nearest neighbours in the discrete fifth dimension. Using this freedom, dynamical breaking of SU(2) gauge symmetry, mass hierarchy patterns of fermions and Cabbibo–Kobayashi–Maskawa matrix may be obtained.

Update on antifibrotic use in glaucoma surgery, including use in trabeculectomy and glaucoma drainage implants and combined cataract and glaucoma surgery.

This paper summarizes the use of antifibrotic agents adjunctive to glaucoma surgery, reviews recently published studies that address current use of these antifibrotics, and reviews new methods of wound modulation. The use of antifibrotic agents, namely, 5-fluorouracil and mitomycin C, in conjunction with glaucoma surgery has resulted in lower postoperative intraocular pressures after trabeculectomy or combined cataract and glaucoma surgery. Mixed results have been seen when these agents are used with glaucoma drainage device surgery. The use of antifibrotic agents has also created and increased complications. Therefore, methods of antifibrotic use have become more refined and modified for specific circumstances. Promising new wound modulation agents, such as CAT-152, are currently under study. Antifibrotics are potent adjuncts to glaucoma surgery, but along with their beneficial use are risks that need to be considered. While we continue to look for more efficacious agents and methods to treat glaucoma, we must continue to modify techniques with the individual patient's best interest in mind.

Global fluctuation spectra in big-crunch–big-bang string vacua

We study big-crunch--big-bang cosmologies that correspond to exact world-sheet superconformal field theories of type II strings. The string theory spacetime contains a big crunch and a big bang cosmology, as well as additional ``whisker'' asymptotic and intermediate regions. Within the context of free string theory, we compute, unambiguously, the scalar fluctuation spectrum in all regions of spacetime. Generically, the big crunch fluctuation spectrum is altered while passing through the bounce singularity. The change in the spectrum is characterized by a function $\ensuremath{\Delta},$ which is momentum and time dependent. We compute $\ensuremath{\Delta}$ explicitly and demonstrate that it arises from the whisker regions. The whiskers are also shown to lead to ``entanglement'' entropy in the big bang region. Finally, in the Milne orbifold limit of our superconformal vacua, we show that $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\Delta}}1$ and, hence, the fluctuation spectrum is unaltered by the big-crunch--big-bang singularity. We comment on, but do not attempt to resolve, subtleties related to gravitational back reaction and light winding modes when interactions are taken into account.

Solar wind modulation of cusp particle signatures and their associated ionospheric flows

This paper presents a multi‐instrument case study of the northern polar cusp at a variety of altitudes in conjunction with solar wind measurements. In the midaltitude cusp the Polar spacecraft observed pulsed particle and magnetic field signatures with periodicities ranging from ∼5 to 40 min for over 3 hours. Simultaneously, the CUTLASS HF radars measured poleward moving radar auroral forms (PMRAFs) with inter‐PMRAF periods similar to the Polar periodicities but several degrees of magnetic latitude poleward of the ionospheric footprint of the spacecraft. Such PMRAFs have previously been identified as ionospheric signatures of transient reconnection and flux transfer events. During this event, both the ACE and Wind spacecraft were making measurements in the solar wind. Oscillations in the time‐shifted solar wind magnetic fields and flows and calculated reconnection electric fields were observed with the same periodicities as those seen by Polar and CUTLASS. We conclude that the solar wind Alfvén waves modulate the dayside interaction, producing periodic flux transfer events resulting in the pulsed cusp particle signatures and PMRAFs. This study is the first observation of solar wind driven pulsed cusp particle signatures and associated PMRAFs, i.e., at both magnetospheric and ionospheric altitudes, at multiple simultaneous discrete periodicities.

Integrable Flows in c = 1 String Theory

In these notes we review the method to construct integrable deformations of the compactified c = 1 bosonic string theory by primary fields (momentum or winding modes), developed recently in collaboration with S. Alexandrov and V. Kazakov. The method is based on the formulation of the string theory as a matrix model. The flows generated by either momentum or winding modes (but not both) are integrable and satisfy the Toda lattice hierarchy.

Application of UF/NF for the treatment of CIP (cleaning in place) rinsing waters: case study in a liquid detergent production plant

In this paper the applicability of ultrafiltration and nanofiltration for the treatment of rinsing water in a liquid detergent plant has been investigated. Suitable membranes have been found in a membrane screening with flat sheet material, pilot experiments with industrial spiral wound modules under realistic conditions have shown the membranes' potential for reducing the COD load in the wastewater by up to 96%. Finally an optimum membrane plant structure has been derived by mixed integer nonlinear programming optimisation based on the experimental results. The membrane plant has been integrated into a model of the water network according to the concept for retrofit optimization of water networks strategy.

Late-time dynamics of brane gas cosmology

Brane gas cosmology is a scenario inspired by string theory which proposes a simple resolution to the initial singularity problem and gives a dynamical explanation for the number of spatial dimensions of our universe. In this work we have studied analytically and numerically the late-time behaviour of these type of cosmologies taking a proper care of the annihilation of winding modes. This has help us to clarify and extend several aspects of their dynamics. We have found that the decay of winding states into non-winding states behaving like a gas of ordinary non-relativistic particles precludes the existence of a late expansion phase of the universe and obstructs the growth of three large spatial dimensions as we observe today. We propose a generic solution to this problem by considering the dynamics of a gas of non-static branes. We have also obtained a simple criterion on the initial conditions to ensure the small string coupling approximation along the whole dynamical evolution, and consequently, the consistency of an effective low-energy description. Finally, we have reexamined the general conditions for a loitering period in the evolution of the universe which could serve as a mechanism to resolve the {\sl brane problem} - a problem equivalent to the {\sl domain wall problem} in standard cosmology - and discussed the scaling properties of a self-interacting network of winding modes taking into account the effects of the dilaton dynamics.

Stabilization of extra dimensions at tree level

By considering the effects of string winding and momentum modes ona time dependent background, we find a method by which six compactdimensions become stabilized naturally at the self-dual radiuswhile three dimensions grow large.

Brane Gases on K3 and Calabi–Yau Manifolds

We initiate the study of Brane Gas Cosmology (BGC) on manifolds with nontrivial holonomy. Such compactifications are required within the context of superstring theory in order to make connections with realistic particle physics. We study the dynamics of brane gases constructed from various string theories on background spaces having a K3 submanifold. The K3 compactifications provide a stepping stone for generalizing the model to the case of a full Calabi–Yau threefold. Duality symmetries are discussed within a cosmological context. Using a duality, we arrive at an N=2 theory in four dimensions compactified on a Calabi–Yau manifold with SU(3) holonomy. We argue that the Brane Gas model compactified on such spaces maintains the successes of the trivial toroidal compactification while greatly enhancing its connection to particle physics. The initial state of the universe is taken to be a small, hot and dense gas of p-branes near thermal equilibrium. The universe has no initial singularity and the dynamics of string winding modes allow three spatial dimensions to grow large, providing a possible solution to the dimensionality problem of string theory.

Soy Protein Concentrates by Ultrafiltration

ABSTRACT: Soybean protein concentrates were produced by ultrafiltration with a commercial 4‐in spiral wound module with a polyvinylidene difluoride membrane. With soy flour suspensions of 2% total solids (TS), protein content could be increased from 50% (dry basis) to 67% by ultrafiltration and/or diafiltration. Soluble sugars could be removed almost completely, but ash content of retentate solids did not decrease significantly. Higher protein contents would require removal of some of the fiber and/or manipulation of the feed environment to reduce solute‐solute interactions. Protein yields were 90%. Flux decreased from 78 L/m2/h (LMH) with 2% TS soy flour suspension to 22 LMH at 17% TS.

Strategic guidelines for street canyon geometry to achieve sustainable street air quality—part II: multiple canopies and canyons

Abstract The flow field and pollutant dispersion characteristics in a three-dimensional urban street canyon are investigated for various building array geometries. The street canyon in consideration is located in a multi-canopy building array that is similar to realistic estate situations. The pollutant dispersion characteristics are studied for various canopy aspect ratios, namely: the canyon height to width ratio, canyon length to height ratio, canyon breadth ratio and crossroad locations are studied. A three-dimensional field-size canyon has been analysed through numerical simulations using k − e turbulence model. As expected, the wind flow and mode of pollutant dispersion is strongly dependent on the various flow geometric configurations and that the results can be different from that of a single canyon system. For example, it is found that the pollutant retention value is minimum when the canyon height-to-width ratio is approximately 0.8, or that the building height ratio is 0.5. Various rules of thumbs on urban canyon geometry have been established for good pollutant dispersion.

Thermal partition function of superstring on compactified pp-wave

We study the thermal partition function of superstring on the pp-wave background with the circle compactification along a transverse direction. We calculate it in the two ways: the operator formalism and the path-integral calculation. The former gives the finite result with no subtlety of the Wick rotation, which only contains the contributions of physical states. On the other hand, the latter yields the manifestly modular invariant expression, even though we only have the winding modes along the transverse circle (no Kaluza–Klein excitations). We also check the equivalence of these two analyses. The DLCQ approach makes the path-integration quite easy. Remarkably, we find that the contributions from the transverse winding sectors disappear in the non-DLCQ limit, while they indeed contribute in the DLCQ model, depending non-trivially on the longitudinal quantum numbers.

Hagedorn inflation: open strings on branes can drive inflation

We demonstrate an inflationary solution to the cosmological horizon problem during the Hagedorn regime in the early universe. Here the observable universe is confined to three spatial dimensions (a three-brane) embedded in higher dimensions. The only ingredients required are open strings on D-branes at temperatures close to the string scale. No potential is required. Winding modes of the strings provide a negative pressure that can drive inflation of our observable universe. Hence the mere existence of open strings on branes in the early hot phase of the universe drives Hagedorn inflation, which can be either power law or exponential. We note the amusing fact that, in the case of stationary extra dimensions, inflationary expansion takes place only for branes of three or less dimensions.

Integrable flows inc 1 string theory

In these notes we review the method to construct integrable deformations of the compactified c=1 bosonic string theory by primary fields (momentum or winding modes), developed recently in collaboration with S. Alexandrov and V. Kazakov. The method is based on the formulation of the string theory as a matrix model. The flows generated by either momentum or winding modes (but not both) are integrable and satisfy the Toda lattice hierarchy.

Satellite observations of modulation of surface winds by typhoon‐induced upper ocean cooling

Two remote sensing data sets, the Tropical Rainfall Measurement Mission Sea Surface Temperature (SST) and the NASA QuikSCAT ocean surface wind vectors, are analysed to study ocean‐atmosphere interactions in cold SST regions formed in the trail of two typhoon events. Anomalously cold SST patches up to 6°C below the surrounding warm tropical ocean SST are found along the trail of typhoon tracks as cold, deep waters are entrained up to the mixed layer due to typhoon forcing. In both typhoon events, significant and systematic weakening of surface wind speed is found over cold SST patches relative to surface wind speed in surrounding regions. The wind speed anomalies disappear as the patches recover to the level of the surrounding SST. The results are consistent with the mechanism proposed by Wallace et al. that surface winds are modulated by SST via stability. As wind within the well‐mixed boundary layer moves over the cold patch, boundary layer stability increases, vertical mixing is suppressed, and the vertical wind shear increases; reduction in surface wind speed is caused. In particular, our result shows that this mechanism can act on relatively small spatial (≈100 km) and short (≈1 day) time scales.

Solar wind modulation of galactic cosmic rays

We have analyzed the annual mean hourly data for the solar wind speed (V), the interplanetary magnetic field (IMF) intensity (B), and the neutron monitor (NM) rates for 1964–1998, covering three sunspot number (SSN) cycles (20, 21, 22). The analysis brings out some of the steady state characteristics of the long‐term changes in the observed galactic cosmic ray (GCR) modulation and the ‘mini’ cycle. We find that BV time series reproduces the observed variations of a variety of phenomena, including the 11‐yr and the 27‐day GCR modulations. We reaffirm that convective removal of GCR by the solar wind accounts for a major part of the observed modulations in the inner heliosphere.

Deconstructing (2,0) and Little String Theories

We argue that two four-dimensional strongly coupled superconformal field theories, on the Higgs branch in certain large N limits, become respectively (2,0) theory and (1,1) little string theory in six dimensions. We identify the spectrum of states responsible for the generation of the two extra dimensions and string winding modes. We establish the equivalence using orbifold realizations of the field theories and exploiting string dualities. We also speculate on deconstructions of M-theory.

The determination of the coronal magnetic field

Measurements of magnetic fields in the solar corona are needed to improve our understanding of structures, dynamics and heating of the corona and of the acceleration of the fast and slow modes of the solar wind expending into the heliosphere. However, those measurements are very difficult and still very scarce. I revue the main methods proposed to access the direction and the strength of the coronal magnetic field and discuss what seem the main avenues to improve its determination in the future.