Interference of chlorofluorocarbon (CFC)‐containing inhalers with measurements of volatile compounds using selected ion flow tube mass spectrometry

Selected ion flow tube mass spectrometry (SIFT-MS) is a sensitive technique capable of measuring volatile compounds (VCs) in complex gas mixtures in real time; it is now being applied to breath analysis. We investigated the effect of inhalers containing chlorofluorocarbons (CFCs) on the detection and measurement of haloamines in human breath. SIFT-MS mass scans (MS) and selected ion monitoring (SIM) scans were performed on three healthy non-smoking volunteers before and after inhalation of the following medications: Combivent™ metered-dose inhaler (MDI) (CFC-containing); Ventolin™ MDI (CFC-free); Atrovent™ MDI (CFC-free), Beclazone™ MDI (CFC-containing); Duolin™ nebuliser. In addition, the duration of the persistence of the mass/charge ratios was measured for 20 h. Inhalers containing CFCs generated large peaks at m/z 85, 87, 101, 103 and 105 in vitro and in vivo, consistent with the predicted product ions of CFCs 12, 114 and 11. No such peaks were seen with Duolin™ via nebuliser, or CFC-free MDIs. We conclude that measurement of VCs, such as haloamines, with product ions of similar m/z values to the ions found for CFCs would be significantly affected by the presence of CFCs in inhalers. This issue needs to be accounted for prior to the measurement of VCs in breath in people using inhalers containing CFCs. Copyright © 2009 John Wiley & Sons, Ltd.     

Four-photon pressure-induced ionization of Xe by 351-nm radiation

The four-photon ionization of xenon gas at 351 nm is observed to be primarily pressure-induced. These observations indicate that the absorption occurs mainly through interaction with bound Xe₂ molecules. A three-photon near-resonance was found to enhance appreciably the cross-section for multiquantum ionization. The radiative lifetime of the resulting Xe¹₂ was determined to be τ_rad = 51 ns, implying only a partial mixing of the 0⁺_u and 1_u, 0^-_u states.     

Solar magnetic fields measurements with a magneto-optical filter

Summary The presence of a magnetic field at different levels inside the Sun has crucial implications for helioseismology. The solar oscillation observing program carried out since 1983 at Mt. Wilson with Cacciani magneto-optical filter (MOF) has recently been modified to acquire full-disk magnetograms with 2 arcsec spatial resolution. We present here a method for the correct determination of magnetic maps which are free of contamination by velocity signal. We show that no cross-talk exists between the Doppler and Zeeman shifts of the NaD lines, provided that instrumental polarization effects are taken into account. We also used the observed line-ofsight photospheric field to map the vector field in the inner corona, above active regions, in the ?current free? approximation.

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Riassunto La presenza di un campo magnetico a differenti livelli dell'interno solare ha importanti implicazioni nell'eliosismologia. Il programma osservativo a Mt. Wilson, in corso dal 1983 con il filtro magneto-ottico di Cacciani, è stato recentemente arricchito con l'acquisizione anche di mappe magnetiche. Si illustra la procedura di riduzione dei dati per una corretta determinazione dei campi magnetici e di velocità. Viene poi utilizzato il campo longitudinale fotosferico per ricostruire il campo magnetico vettoriale a livello coronale, al di sopra delle regioni attive, nell'approssimazione ?current free?.

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Резюме Налччие магнитного поля на различных уровнях внутри Солнца имеет существенное значение для гелиосейсмологии. Программа наблюдения солнечных осцилляций, проводимая с 1983 года на г. Вильсон с помощью магнитно-оптического фильтра, была недавно модифицирована. В этой работе мы предлагаем метод для определения магнитных карт, которые свободны от погрешностей, обусловленных сигналом скорости. Мы показываем, что при учете инструментальных эффектов поляризации, не существует связи между доплеровским и зеемановским сдвигами линий NaD. Мы также используем наблюдаемое поле фотосферы для отобразения векторного поля во внутренней короне, выше, активных областей.

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Paper presented at the 4th Cosmic Physics National Conference, Capri, September 11–14, 1988.

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To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.     

The influence of reorientational collisions on coherent optical processes

Numerical calculations of pulse transmission in SF₆ are performed to appraise the role of reorientational collisions. No support is found for the recent postutate calling for thermally equilibrated magnetic sublevels in self-induced transparency.     

Muonium addition to DMPO and PBN sorbed in silica-gel

Nitroxyl radicals were formed by adding the light hydrogen isotope, muonium to the spin traps DMPO (5,5-dimethyl-1-pyrroline-N-oxide) and PBN (N-tert-butyl-alpha-phenylnitrone) sorbed as 30 wt% ethanol solutions in silica-gel; evidence is presented for a specific hydrogen-bonded interaction between the DMPO adduct and the silica surface; longitudinal-field muon spin relaxation measurements (LF-MuSRx) were performed which identified two distinct motional regimes in both samples.