3,555 research outputs found
Elastic and inelastic breakup of deuterons with energy below 100 MeV
We present calculations of deuteron elastic and inelastic breakup cross
sections and angular distributions at deuteron energies below 100 MeV obtained
using the post-form DWBA approximation. The elastic breakup cross section was
extensively studied in the past. Very few calculations of inelastic breakup
have been performed, however. We also analyze the angular momentum - energy
distributions of the cross section for formation of the compound nucleus after
inelastic breakup.Comment: 7 page
A new flux conserving Newton's method scheme for the two-dimensional, steady Navier-Stokes equations
A new numerical method is developed for the solution of the two-dimensional, steady Navier-Stokes equations. The method that is presented differs in significant ways from the established numerical methods for solving the Navier-Stokes equations. The major differences are described. First, the focus of the present method is on satisfying flux conservation in an integral formulation, rather than on simulating conservation laws in their differential form. Second, the present approach provides a unified treatment of the dependent variables and their unknown derivatives. All are treated as unknowns together to be solved for through simulating local and global flux conservation. Third, fluxes are balanced at cell interfaces without the use of interpolation or flux limiters. Fourth, flux conservation is achieved through the use of discrete regions known as conservation elements and solution elements. These elements are not the same as the standard control volumes used in the finite volume method. Fifth, the discrete approximation obtained on each solution element is a functional solution of both the integral and differential form of the Navier-Stokes equations. Finally, the method that is presented is a highly localized approach in which the coupling to nearby cells is only in one direction for each spatial coordinate, and involves only the immediately adjacent cells. A general third-order formulation for the steady, compressible Navier-Stokes equations is presented, and then a Newton's method scheme is developed for the solution of incompressible, low Reynolds number channel flow. It is shown that the Jacobian matrix is nearly block diagonal if the nonlinear system of discrete equations is arranged approximately and a proper pivoting strategy is used. Numerical results are presented for Reynolds numbers of 100, 1000, and 2000. Finally, it is shown that the present scheme can resolve the developing channel flow boundary layer using as few as six to ten cells per channel width, depending on the Reynolds number
Two Higgs Doublets Model in Gauge-Higgs Unification framework
We discuss the realization of two Higgs doublets model in the framework of 6
dimensional Gauge-Higgs Unification model with a simple Lie group G_M. Two
Higgs SU(2)_L doublets can emerge at the low energy effective theory, and the
quartic coupling terms in the scalar potential, essential for the electroweak
symmetry breaking, are now G_M gauge invariant and permissive. A realistic two
Higgs doublets model can possibly be obtained only when two of the root vectors
associated with the would-be Higgs doublets and the root vector for SU(2)_L
form an isosceles triangle with vertex angle either of Pi/3, Pi/2, or 2Pi/3.
Moreover, depending on G_M, the scalar potential of resulting two Higgs
doublets model can admit only a few limited forms. The mass spectrum of the
physical Higgs and the weak mixing angle are briefly discussed.Comment: 5 Pages and 1 figure. Matches published version in PR
Pricing strategy and technology choices: an empirical investigation of ‘Everyday Low Price’ in the domestic US Airline sector
The Conference program's website is located at http://www.krannert.purdue.edu/faculty/kkarthik/wise12/program.aspINTRODUCTION: There is a rich literature in economics on factors that govern airline prices. With approximately 50% of airline tickets sold online, there is now a renewed interest in investigating airline pricing particularly amongst Information Systems (IS) researchers. While market transparency created by online travel agents (OTAs) is a motivation enough to reexamine airline pricing, one missing piece calls for a thorough empirical investigation: In all extant studies (economics, marketing and IS), pricing by two major airli…postprin
Symmetry and Radiatively Generated Leptogenesis
We consider a symmetry in neutrino sectors realized at GUT scale
in the context of a seesaw model. In our scenario, the exact
symmetry realized in the basis where the charged lepton and heavy Majorana
neutrino mass matrices are diagonal leads to vanishing lepton asymmetries. We
find that, in the minimal supersymmetric extension of the seesaw model with
large , the renormalization group (RG) evolution from GUT scale to
seesaw scale can induce a successful leptogenesis even without introducing any
symmetry breaking terms by hand, whereas such RG effects lead to tiny
deviations of and from and zero,
respectively. It is shown that the right amount of the baryon asymmetry
can be achieved via so-called resonant leptogenesis, which can be
realized at rather low seesaw scale with large in our scenario so
that the well-known gravitino problem is safely avoided.Comment: 17 pages, 5 figures. Published in PR
Nb-doped Gd2O3 as charge-trapping layer for nonvolatile memory applications
published_or_final_versio
The epigenetic regulator ATF7ip inhibits Il2 expression, regulating Th17 responses.
T helper 17 cells (Th17) are critical for fighting infections at mucosal surfaces; however, they have also been found to contribute to the pathogenesis of multiple autoimmune diseases and have been targeted therapeutically. Due to the role of Th17 cells in autoimmune pathogenesis, it is important to understand the factors that control Th17 development. Here we identify the activating transcription factor 7 interacting protein (ATF7ip) as a critical regulator of Th17 differentiation. Mice with T cell-specific deletion of Atf7ip have impaired Th17 differentiation secondary to the aberrant overproduction of IL-2 with T cell receptor (TCR) stimulation and are resistant to colitis in vivo. ChIP-seq studies identified ATF7ip as an inhibitor of Il2 gene expression through the deposition of the repressive histone mark H3K9me3 in the Il2-Il21 intergenic region. These results demonstrate a new epigenetic pathway by which IL-2 production is constrained, and this may open up new avenues for modulating its production
The space-time solution element method: A new numerical approach for the Navier-Stokes equations
This paper is one of a series of papers describing the development of a new numerical method for the Navier-Stokes equations. Unlike conventional numerical methods, the current method concentrates on the discrete simulation of both the integral and differential forms of the Navier-Stokes equations. Conservation of mass, momentum, and energy in space-time is explicitly provided for through a rigorous enforcement of both the integral and differential forms of the governing conservation laws. Using local polynomial expansions to represent the discrete primitive variables on each cell, fluxes at cell interfaces are evaluated and balanced using exact functional expressions. No interpolation or flux limiters are required. Because of the generality of the current method, it applies equally to the steady and unsteady Navier-Stokes equations. In this paper, we generalize and extend the authors' 2-D, steady state implicit scheme. A general closure methodology is presented so that all terms up through a given order in the local expansions may be retained. The scheme is also extended to nonorthogonal Cartesian grids. Numerous flow fields are computed and results are compared with known solutions. The high accuracy of the scheme is demonstrated through its ability to accurately resolve developing boundary layers on coarse grids. Finally, we discuss applications of the current method to the unsteady Navier-Stokes equations
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COPe-support - a multi-component digital intervention for family carers for people affected by psychosis: study protocol for a randomized controlled trial.
BACKGROUND: Psychosis often causes significant distress and impacts not only in the individuals, but also those close to them. Many relatives and friends ('carers') provide long-term support and need resources to assist them. We have co-produced a digital mental health intervention called COPe-support (Carers fOr People with Psychosis e-support) to provide carers with flexible access to high quality psychoeducation and interactive support from experts and peers. This study evaluates the effectiveness of COPe-support to promote mental wellbeing and caregiving experiences in carers. METHODS: This study is a single-blind, parallel arm, individually randomized controlled trial (RCT) comparing COPe-support, with attention control. Both groups continue to receive usual care. COPe-support provides interactive web-based psychoeducation on psychosis-related issues, wellbeing-promotion and network support through forums. The attention-control is a non-interactive online information resource pack. Carers living in England are eligible if they provide at least weekly support to a family member or close friend affected by psychosis, and use internet communication (including emails) daily. All trial procedures are run online, including collection of outcome measurements which participants will directly input into our secure platform. Following baseline assessment, a web-based randomization system will be used to allocate 360 carers to either arm. Participants have unlimited access to the allocated condition for 40 weeks. Data collection is at three time points (10, 20, and 40 weeks after randomization). Analyses will be conducted by trial statisticians blinded to allocation. The primary outcome is mental wellbeing measured by Warwick Edinburgh Mental Wellbeing Scale (WEMWBS), at 20 weeks. As well as an intention-to-treat analysis, a complier average causal effect (CACE) analysis will be conducted to estimate the intervention effect in participants who have accessed COPe-support content twice or more. The secondary objectives and analysis will examine other health and caregiving-related outcomes and explore mechanisms. In a process evaluation, we will interview 20% of the intervention arm participants regarding the acceptability of COPe-support. We will explore in detail participants' usage patterns. DISCUSSION: The results of this trial will provide valuable information about the effectiveness of COPe-support in promoting wellbeing and caregiving experiences in carers. TRIAL REGISTRATION: The RCT is registered with the Current Controlled Trials registration (ISRCTN 89563420, registration date: 02/03/2018)
An extension of Wiener integration with the use of operator theory
With the use of tensor product of Hilbert space, and a diagonalization
procedure from operator theory, we derive an approximation formula for a
general class of stochastic integrals. Further we establish a generalized
Fourier expansion for these stochastic integrals. In our extension, we
circumvent some of the limitations of the more widely used stochastic integral
due to Wiener and Ito, i.e., stochastic integration with respect to Brownian
motion. Finally we discuss the connection between the two approaches, as well
as a priori estimates and applications.Comment: 13 page
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