5,982 research outputs found
Microbial Air Contamination in an Intensive Care Unit
Unit layout affects every aspect of intensive care services, including patient safety. A previous study has shown that patients admitted to beds adjacent to the sink and to the door of a large bayroom had the highest number of positive blood cultures and the highest blood culture incidence density, respectively. The present study measures microbial air contamination in a medical intensive care unit of a medical center in central Taiwan. Of the 17 rooms, 8 rooms with distinct physical environmental characteristics were selected. Sampling tests were conducted between December 2013 and February 2014 with a microbial air sampler (MAS-100NT). TSA was used for bacteria collection and DG18 for fungi collection. The overall average bacterial and fungal concentrations were 83CFU/m3 and 69CFU/m3, respectively. The ranges were between 8-354 CFU/m3 and 0-1468 CFU/m3, respectively. A significant difference was found in the bacterial concentration (p=.005) between different room locations. The highest concentration was found in the rooms located at the front end of the circulation (99 CFU/m3), while the lowest was found in the rooms located at the rear end of the circulation (55CFU/m3). Differences in fungal concentrations for different room locations did not reach statistical significance. In addition, differences in bacterial and fungal concentrations for rooms with different sink locations did not reach statistical significance. Even though the microbial concentrations generally complied with standards, the results may help designers and hospital administrators develop a healthier environment for patients
Macroscopic Quantum Coherence in Small Antiferromagnetic Particle and the Quantum Interference Effects
Starting from the Hamiltonian operator of the noncompensated two-sublattice
model of a small antiferromagnetic particle, we derive the effective Lagrangian
of a biaxial antiferromagnetic particle in an external magnetic field with the
help of spin-coherent-state path integrals. Two unequal level-shifts induced by
tunneling through two types of barriers are obtained using the instanton
method. The energy spectrum is found from Bloch theory regarding the periodic
potential as a superlattice. The external magnetic field indeed removes
Kramers' degeneracy, however a new quenching of the energy splitting depending
on the applied magnetic field is observed for both integer and half-integer
spins due to the quantum interference between transitions through two types of
barriers.Comment: 9 pages, Latex, 4 Postscript figure
The two-atom energy spectrum in a harmonic trap near a Feshbach resonance at higher partial waves
Two atoms in an optical lattice may be made to interact strongly at higher
partial waves near a Feshbach resonance. These atoms, under appropriate
constraints, could be bosonic or fermionic. The universal energy spectrum
for such a system, with a caveat, is presented in this paper, and checked with
the spectrum obtained by direct numerical integration of the Schr\"odinger
equation. The results reported here extend those of Yip for p-wave resonance
(Phys. Rev. A {\bf 78}, 013612 (2008)), while exploring the limitations of a
universal expression for the spectrum for the higher partial waves.Comment: To be published in Physical Review
Control of photon propagation via electromagnetically induced transparency in lossless media
We study the influence of a lossless material medium on the coherent storage
and quantum state transfer of a quantized probe light in an ensemble of
-type atoms. The medium is modeled as uniformly distributed two-level
atoms with same energy level spacing, coupling to a probe light. This coupled
system can be simplified to a collection of two-mode polaritons which couple to
one transition of the -type atoms. We show that, when the other
transition of -type atoms is controlled by a classical light, the
electromagnetically induced transparency can also occur for the polaritons. In
this case the coherent storage and quantum transfer for photon states are
achievable through the novel dark states with respect to the polaritons. By
calculating the corresponding dispersion relation, we find the ensemble of the
three-level atoms with -type transitions may serve as quantum memory
for it slows or even stops the light propagation through the mechanism of
electromagnetically induced transparency. the corresponding dispersion
relation, we find the ensemble of the three-level atoms with -type
transitions may serve as quantum memory for it slows or even stops the light
propagation through the mechanism of electromagnetically induced transparency.Comment: 10 pages, 5 figure
CP Violation in within the Minimal Supersymmetric Standard Model
The complete analysis of the CP violation in the process in frame of the Minimal Supersymmetric Model(MSSM) is presented. The
CP-odd observables for describing the CP violating effects in polarized and
unpolarized photon collisions, are calculated. We investigate the possible CP
violation sources induced by the complex soft breaking parameters and study the
CP violating effects contributed by gluino, neutralino and chargino sectors
appearing in the loop diagrams. We find that it is possible to observe the CP
violation effects in top quark pair production via polarized and unpolarized
photon fusions by using optimal observables and favorable parameters.Comment: 15 pages, LaTex, including 14 figures in eps file
Degradation of methylene blue with magnetic Co-doped Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e@FeOOH nanocomposites as heterogeneous catalysts of peroxymonosulfate
Magnetic Co-doped Fe3O4@FeOOH nanocomposites were prepared in one step using the hydrothermal synthesis process for catalyzing peroxymonosulfate (PMS) to degrade refractory methylene blue (MB) at a wide pH range (3.0–10.0). The catalysts\u27 physiochemical properties were characterized by different equipment; Fe3+/Fe2+ and Co3+/Co2+ were confirmed to coexist in the nanocomposite by X-ray photoelectron spectroscopy. The nanocomposite effectively catalyzed PMS\u27s decoloration (99.2%) and mineralization (64.7%) of MB. The formation of Co/Fe–OH complexes at the surface of nanoparticles was proposed to facilitate heterogeneous PMS activation. Compared with the observation for Fe3O4@FeOOH, the pseudo-first-order reaction constant was enhanced by 36 times due to Co substitution (0.1620 min–1 vs. 0.0045 min–1), which was assigned to the redox recycle of Fe3+/Fe2+ and Co3+/Co2+ in Co-doped Fe3O4@FeOOH. Besides, the catalyst could be easily reused by magnetic separation and exhibited relatively long-term stability
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