94,429 research outputs found
Is God’s Benevolence Impartial?
In this paper I consider the intuitive idea that God is fair and does not play favorites. This belief appears to be held by many theists. I will call it the Principle of Impartial Benevolence (PIB) and put it as follows: As much as possible, for all persons, God equally promotes the good and equally prevents the bad. I begin with the conviction that there is a prima facie tension between PIB and the disparity of human suffering. My aim in what follows is to clarify this tension and show that it runs deep. More specifically, I will argue that PIB imposes stringent demands—including a patient-centered theodicy—on the sorts of reasons that would justify God in permitting suffering, and, that the historical disparity of suffering indicates that these demands are not met. I conclude that theists should disavow PIB or at least consider it sub judice
Nuclear shape coexistence in Po isotopes: An interacting boson model study
Background: The lead region, Po, Pb, Hg, and Pt, shows up the presence of
coexisting structures having different deformation and corresponding to
different particle-hole configurations in the Shell Model language.
Purpose: We intend to study the importance of configuration mixing in the
understanding of the nuclear structure of even-even Po isotopes, where the
shape coexistence phenomena are not clear enough.
Method: We study in detail a long chain of polonium isotopes, 190-208Po,
using the interacting boson model with configuration mixing (IBM-CM). We fix
the parameters of the Hamiltonians through a least-squares fit to the known
energies and absolute B(E2) transition rates of states up to 3 MeV.
Results: We obtained the IBM-CM Hamiltonians and we calculate excitation
energies, B(E2)'s, electric quadrupole moments, nuclear radii and isotopic
shifts, quadrupole shape invariants, wave functions, and deformations.
Conclusions: We obtain a good agreement with the experimental data for all
the studied observables and we conclude that shape coexistence phenomenon is
hidden in Po isotopes, very much as in the case of the Pt isotopes.Comment: To be published in Physical Review C. arXiv admin note: text overlap
with arXiv:1312.459
The influence of intruder states in even-even Po isotopes
We study the role of intruder states and shape coexistence in the even-even
Po isotopes, through an interacting boson model with configuration
mixing calculation. We analyzed the results in the light of known systematics
on various observable in the Pb region, paying special attention to the
unperturbed energy systematics and quadrupole deformation. We find that shape
coexistence in the Po isotopes behaves in very much the same way as in the Pt
isotopes, i.e., it is somehow hidden, contrary to the situation in the Pb and
the Hg isotopes.Comment: Contribution to the Nuclear Structure and Dynamics 2015 (Portorose,
Slovenia) proceeding
The use of high altitude remote sensing in determining existing vegetation and monitoring ecological stress
High altitude color and multispectral black and white photography was used to survey existing vegetation and soil conditions on the Empire Ranch where large scale development will soon begin. Utilizing stereo pairs of the high altitude color photography, four vegetation classifications were discernable as a function of topography and foliage characteristics. In contrast to the undeveloped Ranch, the same photography was used to detect environmental changes in the Tucson metropolitan area as a result of rapid urbanization. The most prevalent change related to development is the removal of vegetation in high density areas to allow for housing starts. Erosion then occurs where vegetation has been removed
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