288 research outputs found
The Cooler Koozie, optimizing thermal insulation for beverage consumption
Our work aims to develop a new koozie with insulating properties that improve upon the current available commercial options. The hot climate of South Carolina, especially during football season, can heat a consumer\u27s beverage to an unenjoyable temperature in a very short period of time. To recreate these hot conditions in a lab setting, our team designed a hot air circulation box with a temperature controller. Our baseline for improvement was established by testing plain cola cans without koozies, cans with basic foam koozies, and cans with more expensive, name brand koozies. Based on these results, we set out to design a new koozie that would outperform those on the current market. Our design focuses on separating the can from the environment by maximizing captured air space between the two. Air is exploited in our design due to its low thermal conductivity, or ability to reduce heat transfer. The material of construction for our koozie is thin wall, flexible PVC tubing wound around in a spiral manner, and then glued together. We are also investigating different diameter tubing to determine the effect differing amounts air space. These results show that our new design has improved insulating properties compared to commercially available koozies while also being aesthetically pleasing
Quantum Bound States with Zero Binding Energy
After reviewing the general properties of zero-energy quantum states, we give
the explicit solutions of the \seq with for the class of potentials
, where , these
solutions are normalizable and correspond to bound states, if the angular
momentum quantum number . [These states are normalizable, even for ,
if we increase the space dimension, , beyond 4; i.e. for .] For the above solutions, although unbound, are normalizable. This is true even
though the corresponding potentials are repulsive for all . We discuss the
physics of these unusual effects.Comment: 11 pages, 4 figures which can be generated from Mathematica commands
given at the end of the file. Latex, REVISED--Fig. 4 Mathematica command
improved and correcte
Diffractive Hard Scattering with a Coherent Pomeron
Diffractive scattering involves exchange of a Pomeron to make a rapidity gap.
It is normally assumed that to get a hard scattering in diffraction, one may
treat the Pomeron as an ordinary particle, which has distributions of gluons
and quarks. We show that this is not so: When we use perturbative QCD, there is
a breakdown of the factorization theorem. The whole Pomeron can initiate the
hard scattering, even though it is not point-like. Qualitatively, but not
quantitatively, this gives the same effect as a delta function term in the
gluon density in a Pomeron.Comment: 13 pages (+ 5 figures, not included), LaTeX, PSU/TH/11
Lunar-Mars Life Support Test Project
Phase 2 of the Lunar-Mars Life Support Test Project was conducted in June and July of 1996 at the NASA Johnson Space Center. The primary objective of Phase 2 was to demonstrate and evaluate an integrated physicochemical air revitalization and regenerative water recovery system capable of sustaining a human crew of four for 30 days inside a closed chamber. The crew (3 males and 1 female) was continuously present inside a chamber throughout the 30-day test. The objective of this paper was to describe crew interactions and human factors for the test. Crew preparations for the test included training and familiarization of chamber systems and accommodations, and medical and psychological evaluations. During the test, crew members provided metabolic loads for the life support systems, performed maintenance on chamber systems, and evaluated human factors inside the chamber. Overall, the four crew members found the chamber to be comfortable for the 30-day test. The crew performed well together and this was attributed in part to team dynamics, skill mix (one commander, two system experts, and one logistics lead), and a complementary mix of personalities. Communication with and support by family, friends, and colleagues were identified as important contributors to the high morale of the crew during the test. Lessons learned and recommendations for future testing are presented by the crew in this paper
RPA-Approach to the Excitations of the Nucleon, Part II: Phenomenology
The tensor-RPA approach developed previously in part I is applied to the
Nambu-Jona-Lasinio (NJL) model. As a first step we investigate the structure of
Dirac-Hartree-Fock solutions for a rotationally and isospin invariant
ground-state density. Whereas vacuum properties can be reproduced, no solitonic
configuration for a system with unit baryon number is found. We then solve the
tensor-RPA equation employing simple models of the nucleon ground state. In
general the ph interaction effects a decrease of the excited states to lower
energies. Due to an enhanced level density at low energies the obtained spectra
cannot be matched with the experimental data when a standard MIT-bag
configuration is used. However, when the size of the nucleon quark core is
reduced to approximately 0.3 fm a fair description of the baryon spectrum in
the positive-parity channel is achieved. For this purpose the residual
interaction turns out to be crucial and leads to a significant improvement
compared with the mean-field spectra.Comment: 33 pages, Latex, 9 Postscpript figures, section on the excited states
has been completely rewritten after error was detected, results are now much
more encouragin
Elastic scattering in geometrical model
The experimental data on proton–proton elastic and inelastic scattering emerging from the measurements at the Large Hadron Collider, calls for an efficient model to fit the data. We have examined the optical, geometrical picture and we have found the simplest, linear dependence of this model parameters on the logarithm of the interaction energy with the significant change of the respective slopes at one point corresponding to the energy of about 300 GeV. The logarithmic dependence observed at high energies allows one to extrapolate the proton–proton elastic, total (and inelastic) cross sections to ultra high energies seen in cosmic rays events which makes a solid justification of the extrapolation to very high energy domain of cosmic rays and could help us to interpret the data from an astrophysical and a high energy physics point of view.Funded by SCOAP
Inelastic diffraction and color-singlet gluon-clusters in high-energy hadron-hadron and lepton-hadron collisions
It is proposed, that ``the colorless objects'' which manifest themselves in
large-rapidity-gap events are color-singlet gluon-clusters due to
self-organized criticality (SOC), and that optical-geometrical concepts and
methods are useful in examing the space-time properties of such objects. A
simple analytical expression for the -dependence of the inelastic single
diffractive cross section ( is the four-momentum transfer
squared) is derived. Comparison with the existing data and predictions for
future experiments are presented. The main differences and similarities between
the SOC-approach and the ``Partons in the Pomeron (Pomeron and
Reggeon)''-approach are discussed.Comment: 12 pages, 2 figure
Process pi p -> pi pi N at high energies and moderate momenta transferred to the nucleon and the determination of parameters of the f_0(980) and f_0(1300)
We present the results of simultaneous analysis of the S-wave pi pi-spectra
in the reactions pi^- p -> (pi^0 pi^0)_S n at p_{lab}=38 GeV/c (GAMS) and pi^-
p -> (pi^+ pi^-)_S n at p_{lab}=18 GeV/c (E852 Collaboration) at moderate
momenta transferred to the nucleon, |t| < 1.5 (GeV/c)^2. The t-distributions
are described by the reggeized pi- and a_1-exchanges provided by the leading
and daughter trajectories, while the M_{pi pi}-spectra are determined by a set
of scalar-isoscalar resonances. With M_{pi pi}-distributions averaged over
t-intervals, we have found several solutions given by different t-channel
exchange mechanisms at |t| ~ (0.5-1.5) (GeV/c)^2, with resonance parameters
close to each other. We conclude that despite a poor knowledge of the structure
of the t-exchange, the characteristics of resonances such as masses and widths
can be reliably determined using the processes under discussion. As to pole
positions, we have found (1031 +/- 10) - i(35 +/- 6) MeV for f_0(980) and (1315
+/- 20) - i(150 +/- 30) MeV for f_0(1300).Comment: 17 pages, RevTeX, 10 EPS figures, misprints correcte
Spin Observables in Antilambda-Lambda Production from Antiproton-Proton Annihilation with a Transverse Inital State Polarization
The formalism describing the scattering of two spin-1/2 objects is reviewed
for the case of antilambda-lambda production from antiproton-proton
annihilation. It is shown that an experiment utilizing a transverse target
polarization can, in principle, completely determine the spin structure of the
reaction. Additional measurements, even those using both beam and target
polarizations, would not be sensitive to any additional spin dynamics. Thus,
the transverse target polarization allows access to the complete set of spin
observables, not just the subset upon which the literature has previously
focused. This discussion is especially relevant in light of the data collected
by PS185/3 at LEAR.Comment: 7 pages, no figure
Backward pion-nucleon scattering
A global analysis of the world data on differential cross sections and
polarization asymmetries of backward pion-nucleon scattering for invariant
collision energies above 3 GeV is performed in a Regge model. Including the
, , and trajectories, we
reproduce both angular distributions and polarization data for small values of
the Mandelstam variable , in contrast to previous analyses. The model
amplitude is used to obtain evidence for baryon resonances with mass below 3
GeV. Our analysis suggests a resonance with a mass of 2.83 GeV as
member of the trajectory from the corresponding Chew-Frautschi
plot.Comment: 12 pages, 16 figure
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