299 research outputs found
Resonant backward scattering of light by a two-side-open subwavelength metallic slit
The backward scattering of TM-polarized light by a two-side-open
subwavelength slit in a metal film is analyzed. We show that the reflection
coefficient versus wavelength possesses a Fabry-Perot-like dependence that is
similar to the anomalous behavior of transmission reported in the study [Y.
Takakura, Phys. Rev. Lett. \textbf{86}, 5601 (2001)]. The open slit totally
reflects the light at the near-to-resonance wavelengths. In addition, we show
that the interference of incident and resonantly backward-scattered light
produces in the near-field diffraction zone a spatially localized wave whose
intensity is 10-10 times greater than the incident wave, but one order of
magnitude smaller than the intra-cavity intensity. The amplitude and phase of
the resonant wave at the slit entrance and exit are different from that of a
Fabry-Perot cavity.Comment: 5 figure
Enhanced Transmission and Reflection of Femtosecond Pulses by a Single Slit
We show that a physical mechanism responsible for the enhanced transmission
and reflection of femtosecond pulses by a single subwavelength nanoslit in a
thick metallic film is the Fabry-Perot-like resonant excitation of stationary,
quasistationary and nonstationary waves inside the slit, which leads to the
field enhancement inside and around the slit. The mechanism is universal for
any pulse-scatter system, which supports the stationary resonances. We point
out that there is a pulse duration limit below which the slit does not support
the intraslit resonance.Comment: 4 pages, 3 figure
Aerosol Pollution from Small Combustors in a Village
Urban air pollution is widely recognized. Recently, there have been a few projects that examined air quality in rural areas (e.g., AUPHEP project in Austria, WOODUSE project in Denmark). Here we present the results within the International Cooperation Project RER/2/005 targeted at studying the effect of local combustion processes to air quality in the village of Brzezina in the countryside north-west of Wroclaw (south western Poland). We identified the potential emission sources and quantified their contributions. The ambient aerosol monitoring (PM10 and elemental concentrations) was performed during 4 measurement cycles, in summer 2009, 2010 and in winter 2010, 2011. Some receptor modeling techniques, factor analysis-multiple linear regression analysis (FA-MLRA) and potential source localization function (PSLF), have been used. Different types of fuel burning along with domestic refuse resulted in an increased concentration of PM10 particle mass, but also by an increased in various other compounds (As, Pb, Zn). Local combustion sources contributed up to 80% to PM10 mass in winter. The effect of other sources was small, from 6 to 20%, dependently on the season. Both PM10 and elemental concentrations in the rural settlement were comparable to concentrations at urban sites in summer and were much higher in winter, which can pose asignificant health risk to its inhabitants
Enhanced transmission versus localization of a light pulse by a subwavelength metal slit: Can the pulse have both characteristics?
The existence of resonant enhanced transmission and collimation of light
waves by subwavelength slits in metal films [for example, see T.W. Ebbesen et
al., Nature (London) 391, 667 (1998) and H.J. Lezec et al., Science, 297, 820
(2002)] leads to the basic question: Can a light be enhanced and simultaneously
localized in space and time by a subwavelength slit? To address this question,
the spatial distribution of the energy flux of an ultrashort (femtosecond)
wave-packet diffracted by a subwavelength (nanometer-size) slit was analyzed by
using the conventional approach based on the Neerhoff and Mur solution of
Maxwell's equations. The results show that a light can be enhanced by orders of
magnitude and simultaneously localized in the near-field diffraction zone at
the nm- and fs-scales. Possible applications in nanophotonics are discussed.Comment: 5 figure
A Treatise on Diversity in a Dominant Culture University
The authors examine progress in strengthening the Diversity agenda in a school of education within a private Christian university. This agenda is informed by external academic accrediting organizations and principles of social justice congruent with the historical roots of the university. Special emphasis is placed on the unique challenges of confronting how privilege manifests itself in seemingly homogeneous environments. The ultimate goal of the authors is to promote moving beyond cosmetic compliance with accreditation obligations towards a metabolized second order change reflecting internal paradigm shifts in which social justice is a central motivating factor in one’s vocation
Characterisation of solid particles emitted from diesel and petrol engines as a contribution to the determination of the origin of carbonaceous particles in urban aerosol
Solid particles emitted from diesel and petrol engines were studied using a scanning electron microscope fitted with an energy dispersive spectrometer. The soot emitted from different engines under different operating conditions differed in particle size, and the form and size of aggregates. Identification of the soot particles emitted from diesel or petrol engines in urban aerosol based on their size and morphology was found to be impossible
Digital Fluency Initiative and Faculty Development
A faculty-led peer mentoring program integrating education technologies and complementary pedagogies to facilitate student engagement and learning outcomes
From Cosmetic to Metabolized Change: Promoting Paradigm Shifts in a Dominant Culture University
The authors provide three case examples modeling the implementation of the Diversity agenda in a school of education within a private Christian university. The second article in a series, the case studies demonstrate contextual application of confronting privilege as it manifests itself in a seemingly homogeneous environment. As the authors document programmatic, personal, and pedagogical methods informed by principles of social justice and equity, the intent is to move beyond cosmetic compliance with accreditation obligations towards a metabolized second order change within students and faculty
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