5,064 research outputs found
Meadowbrook Fox Trot
https://digitalcommons.library.umaine.edu/mmb-ps/1758/thumbnail.jp
Evaluating Roads as Investments: A Primer on Benefit-Cost and Economic-Impact Analysis
Kansas and neighboring states spend billions of dollars on roads. Do the huge expenditures represent good investments? The taxpaying public will never know because public decision makers rarely analyze road projects as investments. A disciplined use of benefit-cost analysis can close this knowledge gap. Roadways constitute an economically vital form of transportation infrastructure that have the potential to contribute to the productivity and economic growth of state economiesâif the economic benefits of the roadways exceed their cost. Benefit-cost analysis totals the annual user benefits derived from road projects and compares these benefits with the total costs related to construction. The analysis, therefore, identifies road projects that have an acceptable or unacceptable return on investment. Consistent and appropriate use of benefit-cost analysis could allow states to allocate road spending to only the highest valued projects, thereby helping to assure that taxpayersâ money generates an acceptable return on investment
Star of My Dreams, Shine On!
https://digitalcommons.library.umaine.edu/mmb-vp/6186/thumbnail.jp
Proton Decay Signatures of Orbifold GUTs
In grand unified theories based on orbifold constructions in higher
dimensions, Higgsino-mediated proton decay is absent. However, proton decay
mediated by and gauge bosons is typically enhanced to levels detectable
by current and future experiments. We analyse the phenomenology of proton decay
induced by the minimal coupling of gauge bosons. In particular, we show
that the novel realization of matter in orbifold GUTs can lead to unusual final
state flavour structure, for example, the dominance of the
mode. Furthermore, we discuss proton decay induced by higher-derivative brane
operators, finding potentially observable rates for natural values of the
operator coefficients.Comment: Latex, 10 pages, referencing error correcte
Blood Lead Levels In Nevada Children
The purpose of this study was to assess the prevalence of plumbism in children one to six years of age in Nevada. During a four-year period from 1992 â 1996, 10,700 children were screened for evidence of blood lead intoxication. The capillary specimens were analyzed by atomic absorption spectrometry. All children with a lead level =\u3e 10 ug/L were retested using venous blood. Ninety three percent of the children had blood lead levels \u3c 10 ”g/d
The Flavour Hierarchy and See-Saw Neutrinos from Bulk Masses in 5d Orbifold GUTs
In supersymmetric grand unified theories (GUTs) based on S^1/(Z_2 x Z'_2)
orbifold constructions in 5 dimensions, Standard Model (SM) matter and Higgs
fields can be realized in terms of 5d hypermultiplets. These hypermultiplets
can naturally have large bulk masses, leading to a localization of the zero
modes at one of the two branes or to an exponential suppression of the mass of
the lowest-lying non-zero mode. We demonstrate that these dynamical features
allow for the construction of an elegant 3-generation SU(5) model in 5
dimensions that explains all the hierarchies between fermion masses and CKM
matrix elements in geometrical terms. Moreover, if U(1)_\chi (where SU(5) x
U(1)_\chi \subset SO(10)) is gauged in the bulk, but broken by the orbifold
action at the SM brane, the right-handed neutrino mass scale is naturally
suppressed relative to M_GUT. Together with our construction in the charged
fermion sector this leads, via the usual see-saw mechanism, to a realistic
light neutrino mass scale and large neutrino mixing angles.Comment: 10 pages LaTeX, 1 figure. Minor comments and reference added. Version
to be published in PL
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