691 research outputs found
Life Cycle Assessment of Food Waste Management Techniques: Loyola University Chicago Lake Shore Campus
Global food waste and loss accounts for about 8% of total anthropogenic greenhouse gas emissions. Targeting and eliminating these man-made emissions will play a critical role in fighting global climate change. At Loyola University Chicago (LUC), climate action and sustainability are key values held by students, faculty, staff, and administrators alike. The goal of this project is to provide a theoretical impact comparison of food waste management techniques proposed for LUC’s Lake Shore Campus. For this study, three processes – commercial composting, anaerobic digestion, and aerobic digestion – were compared based on their global warming potential which was standardized to carbon dioxide
Advanced action in classical electrodynamics
The time evolution of a charged point particle is governed by a second-order
integro-differential equation that exhibits advanced effects, in which the
particle responds to an external force before the force is applied. In this
paper we give a simple physical argument that clarifies the origin and physical
meaning of these advanced effects, and we compare ordinary electrodynamics with
a toy model of electrodynamics in which advanced effects do not occur.Comment: 12 pages, 5 figure
Effective dynamics of an electrically charged string with a current
Equations of motion for an electrically charged string with a current in an
external electromagnetic field with regard to the first correction due to the
self-action are derived. It is shown that the reparametrization invariance of
the free action of the string imposes constraints on the possible form of the
current. The effective equations of motion are obtained for an absolutely
elastic charged string in the form of a ring (circle). Equations for the
external electromagnetic fields that admit stationary states of such a ring are
revealed. Solutions to the effective equations of motion of an absolutely
elastic charged ring in the absence of external fields as well as in an
external uniform magnetic field are obtained. In the latter case, the frequency
at which one can observe radiation emitted by the ring is evaluated. A model of
an absolutely nonstretchable charged string with a current is proposed. The
effective equations of motion are derived within this model, and a class of
solutions to these equations is found.Comment: 14 pages, 3 figures, format changed, minor change
Measurement of Partial-Wave Contributions in pp --> pp pi^0
We report a measurement of the spin-dependent total cross section ratios
delta_sigma_T/sigma_tot and delta_sigma_L/sigma_tot of the pp --> pp pi^0
reaction between 325 MeV and 400 MeV. The experiment was carried out with a
polarized internal target in a storage ring. Non-vertical beam polarization was
obtained by the use of solenoidal spin rotators. Near threshold, the knowledge
of both spin-dependent total cross sections is sufficient to deduce the
strength of certain participating partial waves, free of any model.Comment: 6 pages, 4 figure
Examples of the Zeroth Theorem of the History of Physics
The zeroth theorem of the history of science (enunciated by E. P. Fischer)
and widely known in the mathematics community as Arnol'd's Principle (decreed
by M. V. Berry), states that a discovery (rule, regularity, insight) named
after someone (often) did not originate with that person. I present five
examples from physics: the Lorentz condition defining the Lorentz gauge of the
electromagnetic potentials; the Dirac delta function (x); the Schumann
resonances of the earth-ionosphere cavity; the Weizsacker-Williams method of
virtual quanta; the BMT equation of spin dynamics. I give illustrated thumbnail
sketches of both the true and reputed discoverers and quote from their
"discovery" publications.Comment: 36 pages, 8 figures. Small revisions, added material and references -
Arnol'd's law, Emil Wiechert. Submitted to Am. J. Phy
Nanoscale Smoothing and the Analysis of Interfacial Charge and Dipolar Densities
The interface properties of interest in multilayers include interfacial
charge densities, dipole densities, band offsets, and screening-lengths, among
others. Most such properties are inaccesible to direct measurements, but are
key to understanding the physics of the multilayers. They are contained within
first-principles electronic structure computations but are buried within the
vast amount of quantitative information those computations generate. Thus far,
they have been extracted from the numerical data by heuristic nanosmoothing
procedures which do not necessarily provide results independent of the
smoothing process. In the present paper we develop the theory of nanosmoothing,
establishing procedures for both unpolarized and polarized systems which yield
interfacial charge and dipole densities and band offsets invariant to the
details of the smoothing procedures when the criteria we have established are
met. We show also that dipolar charge densities, i. e. the densities of charge
transferred across the interface, and screening lengths are not invariant. We
illustrate our procedure with a toy model in which real, transversely averaged
charge densities are replaced by sums of Gaussians.Comment: 30 pages, 15 figures, 4 table
Fluorine in AGB Carbon Stars Revisited
A reanalysis of the fluorine abundance in three Galactic AGB carbon stars (TX
Psc, AQ Sgr and R Scl) has been performed from the molecular HF (1-0) R9 line
at 2.3358 m. High-resolution (R) and high signal to noise
spectra obtained with the CRIRES spectrograph and the VLT telescope or from the
NOAO archive (for TX Psc) have been used. Our abundance analysis uses the
latest generation of MARCS model atmospheres for cool carbon rich stars. Using
spectral synthesis in LTE we derive for these stars fluorine abundances that
are systematically lower by dex in average with respect to the sole
previous estimates by Jorissen, Smith & Lambert (1992). The possible reasons of
this discrepancy are explored. We conclude that the difference may rely on the
blending with C-bearing molecules (CN and C) that were not properly taken
into account in the former study. The new F abundances are in better agreement
with the prediction of full network stellar models of low mass AGB stars. These
models also reproduce the -process elements distribution in the sampled
stars. This result, if confirmed in a larger sample of AGB stars, might
alleviate the current difficulty to explain the largest [F/O] ratios found by
Jorissen et al. In particular, it may not be necessary to search for
alternative nuclear chains affecting the production of F in AGB stars.Comment: 25 pages, 3 figures. to be appear in The Astrophysical Journal (Jan
2009 issue
Experimental search for evidence of the three-nucleon force and a new analysis method
A research program with the aim of investigating the spin dependence of the
three-nucleon continuum in pd collisions at intermediate energies was carried
out at IUCF using the Polarized INternal Target EXperiments (PINTEX) facility.
In the elastic scattering experiment at 135 and 200 MeV proton beam energies a
total of 15 independent spin observables were obtained. The breakup experiment
was done with a vector and tensor polarized deuteron beam of 270 MeV and an
internal polarized hydrogen gas target. We developed a novel technique for the
analysis of the breakup observables, the sampling method. The new approach
takes into account acceptance and non-uniformities of detection efficiencies
and is suitable for any kinematically complete experiment with three particles
in the final state.Comment: Contribution to the 19th European Few-Body Conference, Groningen Aug.
23-27, 200
Preliminary Feeding Assessments for Asiatic Garden Beetle, Maladera formosae (Coleoptera: Scarabaeidae), Grubs and Adults
The Asiatic garden beetle, Maladera formosae (Brenske) (syn. M. castanea [Arrow]), is an annual white grub species that was unintentionally introduced from east Asia to North America in 1921 in New Jersey, and has since spread to at least 25 states and two Canadian provinces. Grub populations in the Great Lakes region have recently emerged as significant early-season pests of field crops, particularly field corn, grown in sandy soils. Asiatic garden beetle has also recently become established in other regions including Alabama. Prior research on this species was conducted mainly in the 1930s in horticultural and turfgrass systems of New York and New Jersey. In this study, we document Asiatic garden beetle preference and performance on previously un-investigated food resources, in populations from Ohio and Alabama. The objectives of these experiments were to a) understand if grubs show preference to potential diet choices present in a typical Ohio corn-soybean rotation, and gained mass when provided a single diet, and b) to conduct a preliminary assessment on the development, survival, and fecundity of field-collected beetles on different diets present in suburban Alabama. In general, grubs were more likely to be found at corn and marestail and they significantly increased in body mass when subjected to those diets. However, they were also able to survive and gain mass when provided soybean, crop residues or bare soil. Adults consumed more rose flower petals than floral tissue of white clover and Queen Anne’s lace. In no-choice trials, only females that were fed a diet of rose petals laid eggs, and diet consumption rates were similar among males and females. These findings provide insight into the feeding behaviors of Asiatic garden beetle grubs and adults collected from novel environments
- …