44 research outputs found
High resolution optothermal spectroscopy of pyridine in the S-1 state
The optothermal technique has been utilized to obtain the first high resolution spectrum of pyridine in the region of the S1âS0 electronic transition. Rotational profiles for several vibronic bands (000,6a10,16b206a10,6a20,1210) were measured and found to be severely homogeneously broadened with linewidths of the order of 3â5 GHz, in agreement with previous lifetime measurements. Rotational constants of pyridine in the excited S1 vibronic levels were extracted by a band contour analysis. The values obtained are in good agreement with results from ab initio calculations, also presented here
Measurement of the and Total B Solar Neutrino Fluxes with the Sudbury Neutrino Observatory Phase I Data Set
This article provides the complete description of results from the Phase I
data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is
based on a 0.65 kt-year exposure of heavy water to the solar B neutrino
flux. Included here are details of the SNO physics and detector model,
evaluations of systematic uncertainties, and estimates of backgrounds. Also
discussed are SNO's approach to statistical extraction of the signals from the
three neutrino reactions (charged current, neutral current, and elastic
scattering) and the results of a search for a day-night asymmetry in the
flux. Under the assumption that the B spectrum is undistorted, the
measurements from this phase yield a solar flux of cm s, and a non- component
cm s. The sum of these components provides a
total flux in excellent agreement with the predictions of Standard Solar
Models. The day-night asymmetry in the flux is found to be , when the asymmetry in
the total flux is constrained to be zero.Comment: Complete (archival) version of SNO Phase I results. 78 pages, 46
figures, 34 table
Laser spectroscopy for breath analysis : towards clinical implementation
Detection and analysis of volatile compounds in exhaled breath represents an attractive tool for monitoring the metabolic status of a patient and disease diagnosis, since it is non-invasive and fast. Numerous studies have already demonstrated the benefit of breath analysis in clinical settings/applications and encouraged multidisciplinary research to reveal new insights regarding the origins, pathways, and pathophysiological roles of breath components. Many breath analysis methods are currently available to help explore these directions, ranging from mass spectrometry to laser-based spectroscopy and sensor arrays. This review presents an update of the current status of optical methods, using near and mid-infrared sources, for clinical breath gas analysis over the last decade and describes recent technological developments and their applications. The review includes: tunable diode laser absorption spectroscopy, cavity ring-down spectroscopy, integrated cavity output spectroscopy, cavity-enhanced absorption spectroscopy, photoacoustic spectroscopy, quartz-enhanced photoacoustic spectroscopy, and optical frequency comb spectroscopy. A SWOT analysis (strengths, weaknesses, opportunities, and threats) is presented that describes the laser-based techniques within the clinical framework of breath research and their appealing features for clinical use.Peer reviewe
Innocence and Childhood in Philip Pullmans His Dark Materials
Philip Pullman's young adult fantasy trilogy His Dark Materials combines the
characteristics of the adventure tale with philosophical musings about subjects such as God, sin,
humanity, and death. Among other things, the work engages in a long-standing debate about the
nature of childhood. In this essay, I investigate how the concepts of childhood and innocence are
utilized and discussed in the trilogy. I use historical accounts from various periods, as well as
contemporary research in the field of childhood studies, in order to position the ideas of the trilogy
in the wider context of the history of ideas. The essay shows that His Dark Materials sharply
criticises the Romantic concept of childhood innocence, exposing it as an ideology used to silence
and control children by denying them knowledge and growth. However, as similar Romantic ideas
are employed and expressed in the trilogy by the implied author, His Dark Materials remains
ambiguous as to whether childhood innocence should be completely rejected or not