2,198 research outputs found
The goldstone and goldstino of supersymmetric inflation
We construct the minimal effective field theory (EFT) of supersymmetric
inflation, whose field content is a real scalar, the goldstone for
time-translation breaking, and a Weyl fermion, the goldstino for supersymmetry
(SUSY) breaking. The inflating background can be viewed as a single
SUSY-breaking sector, and the degrees of freedom can be efficiently
parameterized using constrained superfields. Our EFT is comprised of a chiral
superfield X_NL containing the goldstino and satisfying X_NL^2 = 0, and a real
superfield B_NL containing both the goldstino and the goldstone, satisfying
X_NL B_NL = B_NL^3 = 0. We match results from our EFT formalism to existing
results for SUSY broken by a fluid background, showing that the goldstino
propagates with subluminal velocities. The same effect can also be derived from
the unitary gauge gravitino action after embedding our EFT in supergravity. If
the gravitino mass is comparable to the Hubble scale during inflation, we
identify a new parameter in the EFT related to a time-dependent phase of the
gravitino mass parameter. We briefly comment on the leading contributions of
goldstino loops to inflationary observables.Comment: 32 pages, 2 figures. v3: clarifications and references added. Matches
JHEP version. v2: typos fixed, footnote and references adde
Allocation of CO2 Emissions Allowances in the Regional Greenhouse Gas Cap-and-Trade Program
Cap-and-trade programs for air emissions have become the widely accepted, preferred approach to cost-effective pollution reduction. One of the important design questions in a trading program is how to initially distribute the emissions allowances. Under the Acid Rain program created by Title IV of the Clean Air Act, most emissions allowances were distributed to current emitters on the basis of a historic measure of electricity generation in an approach known as grandfathering. Recent proposals have suggested two alternative approaches: allocation according to a formula that is updated over time according to some performance metric in a recent year (the share of electricity generation or something else) and auctioning allowances to the highest bidders. Prior research has shown that the manner in which allowances for carbon dioxide (CO2) are initially distributed can have substantial effects on the social cost of the policy as well as on who wins and who loses as a result of the policy. Another concern with a regional cap-and-trade program like the Regional Greenhouse Gas Initiative (RGGI) is the effect that different approaches to allocating emissions allowances will have on the level of CO2 emissions outside the region, commonly called emissions leakage. In this research we model historic, auction, and updating approaches to allowance allocation that we call bookends, then model various variations on these approaches. We consider changes in measures such as electricity price, the mix of generation technologies, and the emissions of conventional pollutants inside and outside the RGGI region. We examine the social cost of the program, measured as the change in economic surplus, which is the type of measure used in benefit–cost analysis. We also examine the effects of different approaches to distributing allowances on the net present value of generation assets inside and outside the RGGI region. We find that how allowances are allocated has an effect on electricity price, consumption, and the mix of technologies used to generate electricity. Electricity price increases the most with a historic or auction approach. Coal-fired generation in the RGGI region decreases under all approaches but decreases the most under updating. Gas-fired generation decreases under historic and auction approaches but increases substantially under updating. Renewable generation increases under historic and auction approaches but decreases slightly under updating as a consequence of the expanded generation from gas. Consistent with the changes in the composition of generation, the decline in emissions of conventional pollutants including sulfur dioxide (SO2), nitrogen oxides (NOx), and mercury that was expected as a result of the Clean Air Interstate Rule is accelerated substantially as a result of the RGGI policy, particularly under updating. The cost of complying with SO2, NOx, and mercury rules declines similarly. We find that the social costs of the bookend auction and historic approaches are comparable and that the social cost of updating is roughly three times that of the other approaches. At the same time, updating yields greater emissions reductions on a national basis (because it produces less emissions leakage) and greater cumulative reductions in emissions at the national level than historic allocation. Varying the design of the updating approach can reduce its social costs but generally would increase leakage at the same time. An updating approach with allocation to all generators, including all nuclear and renewables has the lowest social cost within the RGGI region of any policy analyzed, although this result comes at the expense of costs imposed outside the region. When the approaches to allocation are mixed, we find the changes in electricity price, generation, and emissions are roughly a combination of the performance of each individual approach. In particular, social costs typically are lower under the scenarios that combine an auction with updating than when updating is the exclusive approach to distributing allowances. Who wins and who loses from the policy varies with the approach to allocation. Under a historic approach, producers in the RGGI region gain substantially and generally are better off than without the program; such is not true under an auction or updating. Producers also gain overall from the policy when a historic allocation is combined with an auction, but the gains are substantially less than in the 100% historic case. Producers outside the region tend to benefit considerably from the higher electricity price in the RGGI region but benefit the least under updating because the effect on electricity price is lowest. Consumers both inside and outside the RGGI region are adversely affected under all allocation approaches but much less so under updating because the change in electricity price is lowest. One exception is when eligibility for allowances under an updating allocation is limited to nonemitters only, in which case the electricity price increases substantially. Different types of generators fare differently under the various allocation approaches. Asset values for all types of generators are highest under a historic approach, although the difference between historic and auction approaches is small for nuclear generators. Compared with the baseline, both nuclear and existing gas-fired generators in the RGGI region gain under an auction. Only gas-fired generators gain under the bookend approach to updating, although nuclear generators benefit as well under updating designs that include them among those eligible for allowances. Coal-fired generators lose the most under updating. Moving from 100% updating to auctioning an increasingly larger share of allowances generally has a positive effect on asset values for all fuel types including coal. The one exception is that moving from 50% auction and 50% updating to 100% auction has a negative effect on the asset values for coal. Finally, we conduct sensitivity analyses with higher natural gas prices and constraints on electricity transmission capability. The social cost of the RGGI program does not appear to be sensitive to these constraints. Higher gas prices or transmission constraints alone impose significant costs that are larger than the effect of adding the RGGI policy. For example, their substantial effect on electricity price is greater than the added effect imposed by the RGGI program. The constraints that are modeled do not appear to have a strong impact on RGGI implementation. We also conduct a sensitivity analysis with renewables portfolio standard policies in place throughout the region. The resulting prices of electricity and CO2 emissions allowances are slightly lower than without the renewables policy.emissions trading, allowance allocations, electricity, air pollution, auction, grandfathering, generation performance standard, output-based allocation, cost-effectiveness, greenhouse gases, climate change, global warming, carbon dioxide, sulfur dioxide, nitrogen oxides, mercury
Presumed Guilty until Proven Innocent: The Burden of Proof in Wrongful Conviction Claims under State Compensation Statutes
Despite significant efforts to uncover and prevent wrongful convictions, little attention has been paid to the compensation of wrongfully convicted individuals once they are released from prison. State compensation statutes offer the best path to redress because they do not require the claimant to prove that the state was at fault for the wrongful conviction and because they are not susceptible to the same political influences as other methods of compensation. However, even under compensation statutes, too many meritorious claims are dismissed, settled for far too little, or never brought in the first place. After examining the current statutory framework, this Article analyzes the arguments for and against one potential solution to this problem that so far has not been considered-shifting the burden of proof to the state on the issue of innocence. Currently, the jurisdictions that have enacted statutes require that the claimant prove his or her innocence in order to recover compensation. Shifting the burden to the state to prove that the claimant is guilty would be more efficient because the state has better access to the relevant evidence, it could rely exclusively on the criminal trial transcript, and it is in a better position to bear the costs of litigation and to determine when to settle. Although this solution implicates several concerns, these concerns can be addressed through checks already built into the criminal justice system and by adjustments that can be made to the compensation statutes
FEASIBILITY OF AN OKLAHOMA FRESH GREENS AND COWPEAS PACKING COOPERATIVE
Oklahoma's green producers are not benefiting from a growing fresh market. In order to seize the opportunities offered by the growing fresh market for leafy greens, investment in packing facilities have been evaluated. To make use of these facilities during summer months, the addition of a cowpea shelling enterprise is considered. A business plan for a new generation cooperative is estimated using an updated version of "The Packing Simulation Model" (PACKSIM) The business associates PACKSIM with @RISK®, to incorporate risks in the financial analysis.Agribusiness,
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Electron ionization via dark matter-electron scattering and the Migdal effect
There are currently several existing and proposed experiments designed to probe sub-GeV dark matter (DM) using electron ionization in various materials. The projected signal rates for these experiments assume that this ionization yield arises only from DM scattering directly off electron targets, ignoring secondary ionization contributions from DM scattering off nuclear targets. We investigate the validity of this assumption and show that if sub-GeV DM couples with comparable strength to both protons and electrons, as would be the case for a dark photon mediator, the ionization signal from atomic scattering via the Migdal effect scales with the atomic number and 3-momentum transfer as . The result is that the Migdal effect is always subdominant to electron scattering when the mediator is light, but that Migdal-induced ionization can dominate over electron scattering for heavy mediators and DM masses in the hundreds of MeV range. We put these two ionization processes on identical theoretical footing, address some theoretical uncertainties in the choice of atomic wave functions used to compute rates, and discuss the implications for DM scenarios where the Migdal process dominates, including for XENON10, XENON100, and the recent XENON1T results on light DM scattering
Technological characterization of phosphate ore types from the Salitre Alkaline Complex, MG - Fosfertil Area
São apresentados os resultados de caracterização tecnológica de seis tipos de minério fosfático provenientes do Complexo de Salitre, tendo em vista definir a composição mineralógica das amostras e as caracterÃsticas inerentes à apatita e ao minério relevantes para o beneficiamento mineral. Os teores de P2O5 variam de 9 a 25% e a proporção de finos (-0,020 mm) situa-se entre 20 e 34% em massa com perdas associadas de 17 a 22% do total de P2O5 presente. As amostras são compostas, essencialmente, por apatita, oxi-hidróxidos de ferro, ilmenita, argilominerais, carbonatos, quartzo, piroxênio, perovskita, alumino-fosfatos e outros minerais acessórios, variando apenas suas proporções relativas. Verificou-se que a apatita ocorre, predominantemente, liberada já abaixo de 0,21 mm, com superfÃcie lÃmpida a fracamente impregnada por oxi-hidróxidos de ferro; a parcela altamente impregnada (não flotável) varia de 6 a 9%. Do total de fósforo contido nas amostras, mais de 97% ocorre sob a forma de apatita (acima de 0,020 mm) e a recuperação potencial estimada de P2O5 na etapa de flotação é superior a 90% (recuperação global estimada entre 71-76%).The present study was carried out on six different ore types from the Salitre Alkaline Complex aiming to determine their mineralogical composition and the major features that are relevant in the mineral processing. The P2O5 grades vary from 9 to 25%. The slime content (-0,020 mm) varies between 20 and 34% (w/w) and carries 17-22% of the P2O5 content. The samples essentially consist of apatite, iron oxi-hydroxides, ilmenite, clayminerals, carbonate, quartz, pyroxene, perovskite, secondary phosphates and other minor accessory minerals. Below 0.21 mm, apatite essentially occurs in free particles showing a clean surface or a weak coating of iron oxi-hydroxides; the highly covered apatite (not recoverable by flotation) varies from 6 to 9%. In the deslimed fraction (above 0.020 mm) more than 97% of the total phosphor content occurs as apatite; the estimated P2O5 potential recovery in flotation concentration is over 90% (71-76% overall recovery).FOSFERTIL - Fertilizantes Fosfatados S.A
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Biguanide therapy for diabetes and cancer & a novel methyltransferase that regulates energy expenditure and adiposity and is elevated in many cancers
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