5,321 research outputs found
Thermal barrier pressure seal
An apparatus is described for providing thermal and pressure sealing in an elongated space of varying width between adjacent surface of two members. The apparatus is mounted for at least limited lateral movement between the members and may comprise: an elongated support attached to one of the adjacent surfaces; a second elongated support member attached to the other of the adjacent surfaces, and an elongated seal member sandwiched between the first and second support members. In its non-deformed state, the elongated seal member may be substantially cylindrical but capable of deformation to accommodate limited lateral movement between the adjacent surfaces and varying widths of the space
Improving School Accountability Measures
A growing number of states are using annual school-level test scores as part of their school accountability systems. We highlight an under-appreciated weakness of that approach the imprecision of school-level test score means -- and propose a method for better discerning signal from noise in annual school report cards. For an elementary school of average size in North Carolina, we estimate that 28 percent of the variance in 5th grade reading scores is due to sampling variation and about 10 percent is due to other non-persistent sources. More troubling, we estimate that less than half of the variance in the mean gain in reading performance between 4th and 5th grade is due to persistent differences between schools. We use these estimates of the variance components in an empirical Bayes framework to generate filtered' predictions of school performance, which have much greater predictive value than the mean for a single year. We also identify evidence of within-school heterogeneity in classroom level gains, which suggests the importance of teacher effects.
MILKING THE MOST FROM YOUR PROMOTIONAL DOLLARS: AN ANALYSIS OF AGRIBUSINESS FIRMS SERVING U.S.AGRICULTURAL PRODUCERS
Although the marketing mix has been covered in great detail in many veins of literature, very little information exists regarding the mix of marketing tools within the agriculture industry serving U.S. agricultural producers. Using a survey conducted by AgriMarketing magazine in June 2006, a two-fold analysis is undertaken. This study attempts to determine the differences in the use of marketing tools by industry and simple regression analysis is conducted to determine promotional factors that produce a significant impact on sales. Both mass media and other promotional tools were found to be the most consistently significant factor impacting sales of firms in the study.marketing mix, agribusiness, promotion, agriculture, marketing, mass media. expenditures
Islamism: What is New, What is Not? Lessons from West Africa
In the aftermath of the Islamic Revolution in Iran of 1979, a marked scholarly interest in Islam driven by policy concerns developed in Western countries. Hitherto the monopoly of a few Orientalists, Islamic studies soon became a multidisciplinary field, attracting experts across the spectrum of the social sciences and the humanities, and indeed beyond academia, and many studies were carried out on Islamism. This article, which focuses on West Africa, questions some of the widely held assumptions on Islamism. The authorâs main argument is that Islamism is not a new phenomenon. A second point made here is that âIslamistâ movements are not primarily Salafi. A third point is that âIslamistsâ are not inherently violent. What is new, according to the author, is the perception of Islamism as a threat in the West
Bounds on Scalar Masses in Theories of Moduli Stabilization
In recent years it has been realised that pre-BBN decays of moduli can be a
significant source of dark matter production, giving a `non-thermal WIMP
miracle' and substantially reduced fine-tuning in cosmological axion physics.
We study moduli masses and sharpen the claim that moduli dominated the pre-BBN
Universe. We conjecture that in any string theory with stabilized moduli there
will be at least one modulus field whose mass is of order (or less than) the
gravitino mass. Cosmology then generically requires the gravitino mass not be
less than about 30 TeV and the cosmological history of the Universe is
non-thermal prior to BBN. Stable LSP's produced in these decays can account for
the observed dark matter if they are `wino-like.' We briefly consider
implications for the LHC, rare decays, and dark matter direct detection and
point out that these results could prove challenging for models attempting to
realize gauge mediation in string theory.Comment: 7 pages. v3: published versio
InN dielectric function from the midinfrared to the visible range
The dispersion of the dielectric function for wurtzite InN is analytically
evaluated in the region near the fundamental energy gap. The real part of the
dielectric function has a logarithmic singularity at the absorption edge. This
results in the large contribution into the optical dielectric constant. For
samples with degenerate carriers, the real part of the dielectric function is
divergent at the absorption edge. The divergence is smeared with temperatures
or relaxation rate. The imaginary part of the dielectric function has a plateau
far away from the absorption onset.Comment: 5 pages, 2 figure
Implied Warranty of Habitability in Leases
This paper will discuss (and take issue with) the position of a significant number of American courts which have held that there is no warranty of habitability implied in a lease. It will demonstrate the failure of many courts in this country to improve the common law rule, which has proven unrealistic in light of current legislative housing standards and building codes
Comment on ``Enhancement of the Tunneling Density of States in Tomonaga-Luttinger Liquids''
In a recent Physical Review Letter, Oreg and Finkel'stein (OF) have
calculated the electron density of states (DOS) for tunneling into a repulsive
Luttinger liquid close to the location of an impurity. The result of their
calculation is a DOS which is enhanced with respect to the pure system, and
moreover diverging for not too strong repulsion. In this Comment we intend to
show that OF's calculation suffers from a subtle flaw which, being corrected,
results into a DOS not only vanishing at zero frequency but in fact suppressed
in comparison with the DOS of a pure Luttinger liquid.Comment: 1 page, Revte
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