18,011 research outputs found
Investigation of exit-velocity stratification effects on jets in a crossflow (STRJET)
Program determines flow field about jets with velocity stratification exhausting into crossflow. Jets with three different types of exit-velocity stratification have been considered: (a) jets with relatively high-velocity core, (b) jets with relatively low-velocity core, and (c) jets originating from vaned nozzle
Analysis of stratified and closely spaced jets exhausting into a crossflow
Procedures have been developed for determining the flow field about jets with velocity stratification exhausting into a crossflow. Jets with three different types of exit velocity stratification have been considered: (1) jets with a relatively high velocity core; (2) jets with a relatively low velocity core; and (3) jets originating from a vaned nozzle. The procedure developed for a jet originating from a high velocity core nozzle is to construct an equivalent nozzle having the same mass flow and thrust but having a uniform exit velocity profile. Calculations of the jet centerline and induced surface static pressures have been shown to be in good agreement with test data for a high velocity core nozzle. The equivalent ideal nozzle has also been shown to be a good representation for jets with a relatively low velocity core and for jets originating from a vaned nozzle in evaluating jet-induced flow fields. For the singular case of a low velocity core nozzle, namely a nozzle with a dead air core, and for the vaned nozzle, an alternative procedure has been developed. The internal mixing which takes place in the jet core has been properly accounted for in the equations of motion governing the jet development. Calculations of jet centerlines and induced surface static pressures show good agreement with test data these nozzles
An Algorithm for Computing Screened Coulomb Scattering in Geant4
An algorithm has been developed for the Geant4 Monte-Carlo package for the
efficient computation of screened Coulomb interatomic scattering. It explicitly
integrates the classical equations of motion for scattering events, resulting
in precise tracking of both the projectile and the recoil target nucleus. The
algorithm permits the user to plug in an arbitrary screening function, such as
Lens-Jensen screening, which is good for backscattering calculations, or
Ziegler-Biersack-Littmark screening, which is good for nuclear straggling and
implantation problems. This will allow many of the applications of the TRIM and
SRIM codes to be extended into the much more general Geant4 framework where
nuclear and other effects can be included.Comment: 19 pages, 6 figures; corrected to rerferee comments, typo in equation
5 fixe
Corporate Responses to Climate Change and Financial Performance: The Impact of Climate Policy
This paper examines the relationship between corporate activities to address climate change and stock performance. By separately analyzing the US and European stock markets for different sub-periods, we highlight the impact of the underlying climate policy regime. Methodologically, we compare risk-adjusted returns of stock portfolios comprising corporations that differ in their responses to climate change. In this respect, we apply the flexible Carhart fourfactor model besides the restricted one-factor model based on the Capital Asset Pricing Model (CAPM). While our portfolio analysis shows negative relationships over the entire observation period from 2001 to 2006, we find that a trading strategy, which bought stocks of corporations with a higher level of responses to climate change and sold stocks of corporations with a lower level, led to negative abnormal returns in regions and periods with less ambitious climate policy, but to positive abnormal returns in regions and periods with stringent climate policy.Climate change, Climate policy, Corporate environmental performance, Financial performance, Portfolio analysis, Asset pricing models
Localization of the genes for tumor necrosis factor and lymphotoxin between the HLA classI and III regions by field inversion gel electrophoresis
To clarify the position of the TNFA and TNFB genes on the HLA map, we have assigned TNFA to large DNA restriction fragments separated by field inversion gel electrophoresis, which hybridize with either class III- or class I-specific probes as well. These results prove that the TNFA locus is localized between the HLA class III region and the HLA-B locus
Presence of an expressed 13-tubulin gene (TUBB) in the HLA class I region may provide the genetic basis for HLA-linked microtubule dysfunction
An expressed beta-tubulin gene (TUBB) has previously
been localized to chromosome region 6pter-p21
in man. By using a panel of deletion mutant cell lines and
radiation-reduced hybrids containing fragments of chromosome
6, the TUBB locus could be mapped to the HLA
class I region at 6p21.3. A long range restriction map including
TUBB and several HLA class I genes was then
generated by rotating field gel electrophoresis. The results
show that TUBB maps to a segment 170-370 kb telomeric
of HLA-C. This location suggests that a mutation at the
TUBB locus could be the cause for certain forms of HLAlinked
microtubule dysfunction, including immotile cilia
syndrome
The difference between Machiavellianism and prognosis in mental patients and prison inmates /
Nonlinear system identification
The prediction of a single observable time series has been achieved with reasonable accuracy and duration for the nonlinear systems developed by Rossler and Lorenz. Based on Takens\u27 Delay-vector Space, an artificial system has been generated using a polynomial least squares technique that includes all possible fifth order combinations of the vectors in the delay space. Furthermore, an optimum shift value has been shown to exist, such that any deviation decreases the accuracy and stability of the prediction. Additionally, an augmented form of the autocorrelation function, similar to the delay vector expansion, has been investigated. The first inflection of this correlation, typically in the dimension of the system, tends to coincide with the optimum shift value required for the best prediction. This method has also been utilized in conjunction with the Grassberger-Procaccia Distance correlation function to accurately determine the fractal dimension of the systems being investigated
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