78,768 research outputs found
Solar Total Energy Project (STEP) Performance Analysis of High Temperature Energy Storage Subsystem
The 1982 milestones and lessons learned; performance in 1983; a typical day's operation; collector field performance and thermal losses; and formal testing are highlighted. An initial test that involves characterizing the high temperature storage (hts) subsystem is emphasized. The primary element is on 11,000 gallon storage tank that provides energy to the steam generator during transient solar conditions or extends operating time. Overnight, thermal losses were analyzed. The length of time the system is operated at various levels of cogeneration using stored energy is reviewed
Recommended from our members
Do Menopausal Women Need Estrogen Replacement to Avoid Osteoporosis?
Integrated Project Teams: The MoD's New Hot Potato?
Since the announcement of Smart Procurement, much has been written on the
potential benefits that IPTs will hopefully bring. It is supposed that they will
improve the interface with industry, create a better understanding of
requirements and establish an environment where industry is motivated to perform
and so reduce cost, risk and time into service while improving product quality.
The formation of a team should provide continuity, consistency, flexibility and
~ increased performance due to the integration of a wide-range of functional
activities and decision-making, as well as increased motivation. These may well
be gallant objectives, but how achievable are they? What obstacles does the MoD
face in the implementation of the IPTs? Have they grasped a 'hot potato'
Classical Sphaleron Rate on Fine Lattices
We measure the sphaleron rate for hot, classical Yang-Mills theory on the
lattice, in order to study its dependence on lattice spacing. By using a
topological definition of Chern-Simons number and going to extremely fine
lattices (up to beta=32, or lattice spacing a = 1 / (8 g^2 T)) we demonstrate
nontrivial scaling. The topological susceptibility, converted to physical
units, falls with lattice spacing on fine lattices in a way which is consistent
with linear dependence on (the Arnold-Son-Yaffe scaling relation) and
strongly disfavors a nonzero continuum limit. We also explain some unusual
behavior of the rate in small volumes, reported by Ambjorn and Krasnitz.Comment: 14 pages, includes 5 figure
Effect of casing treatment of overall performance of axial-flow transonic fan stage with pressure ratio of 1.75 and tip solidity of 1.5
The effect of a number of casing treatments on the overall performance of a 1.75-pressure-ratio, 423-m/sec-tip-speed fan stage was evaluated. The skewed slot configuration with short-open slots over the midportion of the rotor had a stall margin of 23.5 percent, while the solid casing had a stall margin of 15.0 percent. The skewed slot configuration with long open slots extending ahead of and over portion of rotor displaced the stall line to the lowest flow at all speeds tested. At design speed, the peak efficiency for the long, forward open slots was 1 point less than that for the short midopen slots and 3 points less than that for the solid casing
Transport properties of the one-dimensional Hubbard model at finite temperature
We study finite-temperature transport properties of the one-dimensional
Hubbard model using the density matrix renormalization group. Our aim is
two-fold: First, we compute both the charge and the spin current correlation
function of the integrable model at half filling. The former decays rapidly,
implying that the corresponding Drude weight is either zero or very small.
Second, we calculate the optical charge conductivity sigma(omega) in presence
of small integrability-breaking next-nearest neighbor interactions (the
extended Hubbard model). The DC conductivity is finite and diverges as the
temperature is decreased below the gap. Our results thus suggest that the
half-filled, gapped Hubbard model is a normal charge conductor at finite
temperatures. As a testbed for our numerics, we compute sigma(omega) for the
integrable XXZ spin chain in its gapped phase
Electroweak Baryogenesis with dimension-6 Higgs interactions
We present the computation of the baryon asymmetry in the SM amplified by
dimension-6 Higgs interactions using the WKB approximation. Analyzing the
one-loop potential it turns out that the phase transition is strongly first
order in a wide range of the parameters. It is ensured not to wash out the net
baryon number gained previously even for Higgs masses up to at least 170 GeV.
In addition dimension-6 operators induce new sources of CP violation. Novel
source terms which enhance the generated baryon asymmetry emerge in the
transport equations. This model predicts a baryon to entropy ratio close to the
observed value for a large part of the parameter space.Comment: 10 pages, 4 figures, Talk given at the 8th International Moscow
School of Physic
- …