Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
Data Brief ; 21: 1337-1346, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30456255

ABSTRACT

Data for six electric vehicle WOT interior sound measurements and eight enhanced sound signatures are presented. The measurement of electric vehicle interior sound signature data and the enhancement of these stimuli are documented in this data article. The procedures and equipment that were used to record the data, as well as the transposition, harmony and order addition, frequency filtering and modulation enhancement techniques that were applied to these stimuli are explained in detail. The transient frequency content of the 12 sound stimuli is presented in acoustic spectrograms along with the audio files in.mp3 format.

2.
Talanta ; 58(1): 189-99, 2002 Aug 16.
Article in English | MEDLINE | ID: mdl-18968745

ABSTRACT

Several techniques based on laser induced fluorescence (LIF) spectrometry and laser enhanced ionization (LEI) spectrometry have been investigated for ultratrace measurements of arsenic. Studies by our group in this area that have been published previously are reviewed here, and are presented along with the results of recent studies that have not yet been published. The techniques presented include LIF detection in the inductively coupled plasma atomizer, the electrothermal atomizer, the tungsten coil atomizer, the flame atomizer and LEI detection in the flame atomizer, and include approaches that utilize hydride generation or laser ablation sample introduction. Recent efforts have been directed towards developing speciation approaches for arsenic that utilize LIF spectrometric detection. The capabilities of each technique are summarized including the sensitivity and limits of detection, which range from sub-pg ml(-1) to ng ml(-1) levels. Selected applications of the techniques are presented to demonstrate their utility for environmental and biological samples, and areas for future investigation and further development are discussed.

3.
Anal Chem ; 71(21): 4951-5, 1999 Nov 01.
Article in English | MEDLINE | ID: mdl-10565284

ABSTRACT

A procedure for the direct determination of arsenic in diluted serum by electrothermal atomization laser-excited atomic fluorescence spectrometry (ETA-LEAFS) is reported. Laser radiation needed to excite As at 193.696 and 197.197 nm is generated as the second anti-Stokes stimulated Raman scattering output of a frequency-doubled dye laser operating near 230.5 and 235.5 nm, respectively. Two different LEAFS schemes have been utilized and provide limits of detection of 200-300 fg for As in aqueous standards. When measurements of serum samples diluted 1:10 with deionized water are performed, a stable background signal is observed that can be accounted for by taking measurements with the laser tuned off-wavelength. No As is detected in any of the bovine or human serum samples analyzed. Measurements of 100 pg/mL standard additions of As to a diluted bovine serum sample utilizing either inorganic or organic As species demonstrate a linear relationship of the fluorescence signal to As spike concentration, but exhibit a sensitivity of approximately half that observed in pure aqueous standards. The limit of detection for As in 1:10 diluted serum samples is 65 pg/mL or 650 fg absolute mass, which corresponds to 0.65 ng/mL As in undiluted serum. To our knowledge, the ETA-LEAFS procedure is currently the only one capable of directly measuring As in diluted serum at these levels.


Subject(s)
Arsenic/blood , Spectrometry, Fluorescence/methods , Animals , Arsenic/chemistry , Calibration , Cattle , Electrochemistry/methods , Humans , Lasers , Sensitivity and Specificity , Spectrometry, Fluorescence/instrumentation
4.
Anal Chem ; 70(7): 1324-30, 1998 Apr 01.
Article in English | MEDLINE | ID: mdl-21644729

ABSTRACT

Trace detection of Se, As, and Sb atoms has been performed by electrothermal atomization laser-induced fluorescence (ETA-LIF) approaches. Production of far-UV radiation necessary for excitation of As atoms at 193.696 nm and Se atoms at 196.026 nm was accomplished by stimulated Raman shifting (SRS) of the output of a frequency-doubled dye laser operating near 230 nm. Both wavelengths were obtained as second-order anti-Stokes shifts of the dye laser radiation and provided up to 10 µJ/pulse, which was shown through power dependence studies to be sufficient for saturation in the ETA. An excited-state direct line fluorescence approach using excitation at 206.279 nm was also investigated for the LIF detection of Se. High-sensitivity LIF of Sb atoms was accomplished using 206.833-nm excitation and detection at 259.805 nm. The accuracy of the ETA-LIF approaches was demonstrated by determining the As and Se content of aqueous reference samples. The limits of detection (absolute mass) were 200 fg by ground-state LIF and 150 fg by excited-state direct line fluorescence for Se, 200 fg for As, and 10 fg for Sb; these LODs compare favorably with results reported previously in the literature for ETA-LIF, GFAAS, and ICP-MS methods.

5.
S Afr Med J ; 64(18): 693-6, 1983 Oct 22.
Article in English | MEDLINE | ID: mdl-6623275

ABSTRACT

The tolerability and efficacy of a 6-month daily regimen of rifampicin (RMP), isoniazid (INH) and pyrazinamide (PZA) were tested in 130 hospitalized patients, mostly Black, with previously untreated pulmonary tuberculosis. PZA was discontinued at the end of the 2nd month. In 6 cases treatment was discontinued because of drug intolerance. The symptoms were severe rash, mild thrombocytopenia, deteriorating haematological and renal condition and in the remaining 3 patients hyperbilirubinaemia. Of the 125 patients who could be assessed bacteriologically, 110 were infected with organisms which were fully susceptible to INH and RMP, and 95% of their cultures and 77% of their smears had converted to negative after 2 months of treatment. Similar results were obtained for all but 2 of the 15 patients with drug-resistant bacilli. Cavitation of the lungs was reduced in 78% of the patients and the extent of other tuberculous lesions diminished in 87%.


Subject(s)
Isoniazid/therapeutic use , Pyrazinamide/therapeutic use , Rifampin/therapeutic use , Tuberculosis, Pulmonary/drug therapy , Adolescent , Adult , Drug Therapy, Combination , Drug Tolerance , Female , Humans , Male , Middle Aged , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...