17,175 research outputs found
One-step dual purpose joining technique
This fastener used in induction heating is a wire screen basically of an eddy current carrying material such as carbon steel. Selected wires in the screen are copper, sheathed in an insulating material. The screen is placed between two sheets of thermoplastics. When inductively heated, the composite softens and flows around the apertures of the screen. After this heating and joining, the copper wires may be used to conduct electricity
Dark Matter Subhalos In the Fermi First Source Catalog
The Milky Way's dark matter halo is thought to contain large numbers of
smaller subhalos. These objects can contain very high densities of dark matter,
and produce potentially observable fluxes of gamma rays. In this article, we
study the gamma ray sources in the Fermi Gamma Ray Space Telescope's recently
published First Source Catalog, and attempt to determine whether this catalog
might contain a population of dark matter subhalos. We find that, while
approximately 20-60 of the catalog's unidentified sources could plausibly be
dark matter subhalos, such a population cannot be clearly identified as such at
this time. From the properties of the sources in the First Source Catalog, we
derive limits on the dark matter's annihilation cross section that are
comparably stringent to those derived from recent observations of dwarf
spheroidal galaxies.Comment: 11 pages, 9 figures V2: Minor errors in Figure 3 correcte
Asymmetric Dark Matter and Effective Operators
In order to annihilate in the early Universe to levels well below the
measured dark matter density, asymmetric dark matter must possess large
couplings to the Standard Model. In this paper, we consider effective operators
which allow asymmetric dark matter to annihilate into quarks. In addition to a
bound from requiring sufficient annihilation, the energy scale of such
operators can be constrained by limits from direct detection and monojet
searches at colliders. We show that the allowed parameter space for these
operators is highly constrained, leading to non-trivial requirements that any
model of asymmetric dark matter must satisfy.Comment: 6 pages, 1 figure. V2 replacement: Citations added. Shading error in
Fig. 1 (L_FV panel) corrected. Addition of direct detection bounds on m_chi
<5 GeV added, minor alterations in text to reflect these change
Baseline-and-Credit Emission Permit Trading: Experimental Evidence Under Variable Output Capacity
Two approaches to emissions trading are cap-and-trade, in which an aggregate cap on emissions is distributed in the form of allowance permits, and baseline-and-credit, in which firms earn emission reduction credits for emissions below their baselines. Theoretical considerations suggest the long-run equilibria of the two plans will differ if baselines are proportional to output, because a variable baseline is equivalent to an output subsidy. As a progressive step towards testing the full long-run model, this paper reports on a laboratory experiment designed to test the prediction under fixed emission rates and variable output capacity. A computerized environment has been created in which sub jects representing firms choose output capacities under fixed emission technology and participate in markets for emission rights and for output. Demand for output is simulated. All decisions are tracked through a double-entry bookkeeping system. Our evidence supports the theoretical prediction that aggregate output and emissions are inefficiently high under a baseline-and-credit trading plan compared to a corresponding cap-and-trade plan.
Long-Run Implications of Alternative Emission Trading Plans: An Experiment with Robot Traders
Two approaches to emissions trading are cap-and-trade, in which an aggregate cap on emissions is distributed in the form of permits, and baseline-and-credit, in which firms earn credits for emissions below their baselines. Theoretical considerations suggest the long-run equilibria of the two plans will differ if baselines are proportional to output, because a variable baseline is equivalent to an output subsidy. This paper reports on a laboratory environment designed to test this prediction. A computerized environment has been created in which subjects representing firms choose capacity and emission rates and participate in markets for permits or credits and for output. Demand for output is simulated. All decisions are tracked through a double-entry bookkeeping system. The timing of decisions was adjusted to avoid short-run instability. The paper reports the parameterization for an experiment with human traders and results of a simulated experiment using robots.
Baseline-and-Credit Style Emission Trading Mechanisms: An Experimental Investigation of Economic Inefficiency
Two approaches to emissions trading are cap-and-trade, in which an aggregate cap on emissions is distributed in the form of allowance permits, and baseline-and-credit, in which firms earn emission reduction credits for emissions below their baselines. Theoretical considerations suggest the long-run equilibria of the two plans will differ if baselines are proportional to output, because a variable baseline is equivalent to an output subsidy. This paper reports on a laboratory experiment designed to test the prediction in a laboratory environ- ment in which sub jects representing firms choose emission technologies and output capacities. A computerized environment has been created in which sub jects participate in markets for emission rights and for output. Demand for output is simulated. All decisions are tracked through a double-entry bookkeeping system. Our evidence supports the theoretical prediction that aggregate output and emissions are in- efficiently high under a baseline-and-credit trading plan compared to a corresponding cap-and-trade plan.
Glean Logan comparisons
Rates and timing of application, 89ME79, 89NO72, 89WH81, 89WH75. Hoegrass tankmixes, Brodal, Glean, 89M58. Grasp efficacy, rates and timing of application to wheat, 89NO71. Grasp tolerance, rates and timing of application to wheat, 89A17, and 89WH62. Silvergrass control in pasture. Simazine, Pursuit, 89KA67, 89LG60, 89NO73. Marshmallow control in crop, 89NO98. Glyphosate formulation comparisons, 89WH78, 89A27. Diclofop-methyl formulation comparisons, 89A28. Pursuit on pasture, rate and additives, 89LG61, 89LG60, 89LG58, 89A26. Selective grass controllers with Simazine on pasture 89M64, 89LG59. Cape tulip control in pasture, 89NA73, 89NA72
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