696 research outputs found
Levi-Civita Effect in the polarizable vacuum (PV) representation of general relativity
The polarizable vacuum (PV) representation of general relativity (GR),
derived from a model by Dicke and related to the "TH-epsilon-mu" formalism used
in comparative studies of gravitational theories, provides for a compact
derivation of the Levi-Civita Effect (both magnetic and electric), herein
demonstrated.Comment: 8 page
Pair production of neutralinos via gluon-gluon collisions
The production of a neutralino pair via gluon-gluon fusion is studied in the
minimal supersymmetric model(MSSM) at proton-proton colliders. The numerical
analysis of their production rates are carried out in the mSUGRA scenario. The
results show that this cross section may reach about 80 femto barn for
pair production and 23 femto barn
for pair production with suitable
input parameters at the future LHC collider. It shows that this loop mediated
process can be competitive with the quark-antiquark annihilation process at the
LHC.Comment: LaTex file, l4 pages, 5 EPS figure
Finite Number and Finite Size Effects in Relativistic Bose-Einstein Condensation
Bose-Einstein condensation of a relativistic ideal Bose gas in a rectangular
cavity is studied. Finite size corrections to the critical temperature are
obtained by the heat kernel method. Using zeta-function regularization of
one-loop effective potential, lower dimensional critical temperatures are
calculated. In the presence of strong anisotropy, the condensation is shown to
occur in multisteps. The criteria of this behavior is that critical
temperatures corresponding to lower dimensional systems are smaller than the
three dimensional critical temperature.Comment: 18 pages, 9 figures, Fig.3 replaced, to appear in Physical Review
Effects of Pore Walls and Randomness on Phase Transitions in Porous Media
We study spin models within the mean field approximation to elucidate the
topology of the phase diagrams of systems modeling the liquid-vapor transition
and the separation of He--He mixtures in periodic porous media. These
topologies are found to be identical to those of the corresponding random field
and random anisotropy spin systems with a bimodal distribution of the
randomness. Our results suggest that the presence of walls (periodic or
otherwise) are a key factor determining the nature of the phase diagram in
porous media.Comment: REVTeX, 11 eps figures, to appear in Phys. Rev.
Targeted delivery of cisplatin to tumor xenografts via the nanoparticle component of nano-diamino-tetrac
Aim: Nano-diamino-tetrac (NDAT) targets a receptor on integrin alpha v beta 3; alpha v beta 3 is generously expressed by cancer cells and dividing endothelial cells and to a small extent by nonmalignant cells. The tetrac (tetraiodothyroacetic acid) of NDAT is covalently bound to a poly(lactic-co-glycolic acid) nanoparticle that encapsulates anticancer drugs. We report NDAT delivery efficiency of cisplatin to agent-susceptible urinary bladder cancer xenografts. Materials & methods: Cisplatin-loaded NDAT (NDAT-cisplatin) was administered to xenograft-bearing nude mice. Tumor size response and drug content were measured. Results: Intratumoral drug concentration was up to fivefold higher (p NDAT without cisplatin > cisplatin alone. Conclusion: NDAT markedly enhances cisplatin delivery to urinary bladder cancer xenografts and increases drug efficacy.NanoPharmaceuticals LLC (NY, USA)NanoPharmaceuticals LL
Precision charging of microparticles in plasma via the Rayleigh instability for evaporating charged liquid droplets
In this paper we describe a novel method for delivering a precise, known amount of electric charge to a micron-sized solid target. Aerosolised microparticles passed through a plasma discharge will acquire significant electric charge. The fluid stability under evaporative stress is a key aspect that is core to the research. Initially stable charged aerosols subject to evaporation (i.e. a continually changing radius) may encounter the Rayleigh stability limit. This limit arises from the electrostatic and surface tension forces and determines the maximum charge a stable droplet can retain, as a function of radius. We demonstrate that even if the droplet charge is initially much less than the Rayleigh limit, the stability limit will be encountered as the droplet evaporates. The instability emission mechanism is strongly linked to the final charge deposited on the target, providing a mechanism that can be used to ensure a predictable charge deposit on a known encapsulated microparticle
Random Convex Hulls and Extreme Value Statistics
In this paper we study the statistical properties of convex hulls of
random points in a plane chosen according to a given distribution. The points
may be chosen independently or they may be correlated. After a non-exhaustive
survey of the somewhat sporadic literature and diverse methods used in the
random convex hull problem, we present a unifying approach, based on the notion
of support function of a closed curve and the associated Cauchy's formulae,
that allows us to compute exactly the mean perimeter and the mean area enclosed
by the convex polygon both in case of independent as well as correlated points.
Our method demonstrates a beautiful link between the random convex hull problem
and the subject of extreme value statistics. As an example of correlated
points, we study here in detail the case when the points represent the vertices
of independent random walks. In the continuum time limit this reduces to
independent planar Brownian trajectories for which we compute exactly, for
all , the mean perimeter and the mean area of their global convex hull. Our
results have relevant applications in ecology in estimating the home range of a
herd of animals. Some of these results were announced recently in a short
communication [Phys. Rev. Lett. {\bf 103}, 140602 (2009)].Comment: 61 pages (pedagogical review); invited contribution to the special
issue of J. Stat. Phys. celebrating the 50 years of Yeshiba/Rutgers meeting
Roles of Nutrient Limitation on Western Lake Erie CyanoHAB Toxin Production
Cyanobacterial harmful algal bloom (CyanoHAB) proliferation is a global problem impacting ecosystem and human health. Western Lake Erie (WLE) typically endures two highly toxic CyanoHABs during summer: a Microcystis spp. bloom in Maumee Bay that extends throughout the western basin, and a Planktothrix spp. bloom in Sandusky Bay. Recently, the USA and Canada agreed to a 40% phosphorus (P) load reduction to lessen the severity of the WLE blooms. To investigate phosphorus and nitrogen (N) limitation of biomass and toxin production in WLE CyanoHABs, we conducted in situ nutrient addition and 40% dilution microcosm bioassays in June and August 2019. During the June Sandusky Bay bloom, biomass production as well as hepatotoxic microcystin and neurotoxic anatoxin production were N and P co-limited with microcystin production becoming nutrient deplete under 40% dilution. During August, the Maumee Bay bloom produced microcystin under nutrient repletion with slight induced P limitation under 40% dilution, and the Sandusky Bay bloom produced anatoxin under N limitation in both dilution treatments. The results demonstrate the importance of nutrient limitation effects on microcystin and anatoxin production. To properly combat cyanotoxin and cyanobacterial biomass production in WLE, both N and P reduction efforts should be implemented in its watershed
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
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