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Dive into the research topics where Kenneth H. Shafer is active.

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Featured researches published by Kenneth H. Shafer.


Journal of Occupational and Environmental Hygiene | 2016

Insights from two industrial hygiene pilot e-cigarette passive vaping studies

John C. Maloney; Mike Thompson; Michael J. Oldham; Charles L. Stiff; Patrick D. Lilly; George J. Patskan; Kenneth H. Shafer; Mohamadi A. Sarkar

ABSTRACT While several reports have been published using research methods of estimating exposure risk to e-cigarette vapors in nonusers, only two have directly measured indoor air concentrations from vaping using validated industrial hygiene sampling methodology. Our first study was designed to measure indoor air concentrations of nicotine, menthol, propylene glycol, glycerol, and total particulates during the use of multiple e-cigarettes in a well-characterized room over a period of time. Our second study was a repeat of the first study, and it also evaluated levels of formaldehyde. Measurements were collected using active sampling, near real-time and direct measurement techniques. Air sampling incorporated industrial hygiene sampling methodology using analytical methods established by the National Institute of Occupational Safety and Health and the Occupational Safety and Health Administration. Active samples were collected over a 12-hr period, for 4 days. Background measurements were taken in the same room the day before and the day after vaping. Panelists (n = 185 Study 1; n = 145 Study 2) used menthol and non-menthol MarkTen prototype e-cigarettes. Vaping sessions (six, 1-hr) included 3 prototypes, with total number of puffs ranging from 36–216 per session. Results of the active samples were below the limit of quantitation of the analytical methods. Near real-time data were below the lowest concentration on the established calibration curves. Data from this study indicate that the majority of chemical constituents sampled were below quantifiable levels. Formaldehyde was detected at consistent levels during all sampling periods. These two studies found that indoor vaping of MarkTen prototype e-cigarette does not produce chemical constituents at quantifiable levels or background levels using standard industrial hygiene collection techniques and analytical methods.


Contributions to Tobacco Research | 2014

Laboratory Evaluation of the CReSSmicro™ Portable Topography Device: Implications for Clinical Research

Michael J. Oldham; Susan E. Plunkett; Michael T. Fisher; Kenneth H. Shafer; Michael J. Morton

SUMMARY Performance of the CReSSmicro™ v.2.0.0 portable smoking topography device was evaluated in a controlled laboratory environment using a calibrated smoking machine to generate known, reproducible smoking topographies. Device performance was evaluated using unlit and lit cigarettes over a range of puff volumes (25 to 100 mL) at 2 s puff duration using a sine wave profile. The device missed 93% and 100% of the 25 mL/2 s puffs for unlit and lit cigarettes, respectively. The device underreported puff durations for the entire volume range, i.e., from 40 mL (0.9 ± 0.17 s) to 100 mL (1.6 ± 0.11 s) for both unlit and lit cigarettes. Puff volumes were under reported for lower volumes from 40 mL (25.6 ± 5.5 mL) to 70 mL (68.8 ± 3.7 mL) for both unlit and lit cigarettes and slightly over reported for higher volumes from 85 mL (89.4 ± 7.6 mL) to 100 mL (103.4 ± 9.8 mL) for lit cigarettes. Experimental results indicated that a 12.5-20mL/s (750-1,200 mL/min) flow threshold for puff recognition was responsible for the observed results. This study reinforces the importance of fully understanding device performance prior to performing clinical studies of human smoking topography. [Beitr. Tabakforsch. Int. 26 (2014) 19-25] ZUSAMMENFASSUNG Die Leistungsfähigkeit des mobilen Rauchtopographiegerätes CReSSmicro™ v.2.0.0 wurde in einer kontrollierten Laborumgebung untersucht. Dabei wurde eine kalibrierte Abrauchmaschine eingesetzt, um bekannte, reproduzierbare Rauchtopographien zu erzeugen. Die Maschinenleistung wurde mit Hilfe von angezündeten und nicht angezündeten Zigaretten mit unterschiedlichen Zugvolumina (25 bis 100 mL) mit einer Zugdauer von 2 s und einem Sinusprofil untersucht. Bei den nicht angezündeten bzw. angezündeten Zigaretten wurden jeweils 93 % bzw. 100 % der 25 mL/2 s- Züge vom Gerät nicht gezählt. Das Gerät wies in allen gewählten Volumina, d.h. von 40 mL (0,9 ± 0,17 s) bis 100 mL (1,6 ± 0,11 s), für sowohl nicht angezündete als auch angezündete Zigaretten eine zu geringe Zugdauer aus. Die Zugvolumina wurden bei den niedrigeren Volumina von 40 mL (25,6 ± 5,5 mL) bis 70 mL (68,8 ± 3,7 mL) für sowohl nicht angezündete als auch angezündete Zigaretten geringer als tatsächlich angegeben und bei den höheren Volumina von 85 mL (89,4 ± 7,6 mL) bis 100 mL (103,4 ± 9,8 mL) für angezündete Zigaretten etwas zu hoch angegeben. Die Versuchsergebnisse zeigten, dass ein Durchflussschwellenwert von 12,5-20 mL/s (750-1.200 mL/min) bei der Bestimmung der Züge für die beobachteten Ergebnisse verantwortlich war. Diese Studie unterstreicht, wie wichtig es ist, die Leistungsfähigkeit der Maschinen genau zu kennen, bevor klinische Studien zur Rauchtopographie beim Menschen durchgeführt werden können. [Beitr. Tabakforsch. Int. 26 (2014) 19-25] RESUME La performance de l’appareil portable de topographie du fumage CReSSmicro™ v.2.0.0 a été évaluée en milieu contrôlé dans un laboratoire, en utilisant une machine à fumer étalonnée pour générer des topographies du fumage reproductibles connues. La performance de l’appareil a été évaluée au moyen de cigarettes non-allumées et allumées dans une plage de volumes de bouffées (de 25 à 100 mL) pour une durée de bouffée de 2 s en utilisant un profil d’onde sinusoïdale. L’appareil s’est trompé pour 93% et 100% des bouffées de 25 mL/2 s avec les cigarettes nonallumées et allumées respectivement. L’appareil a sousestimé les durées de bouffées sur toute la plage de volumes, c’est-à-dire de 40 mL (0,9 ± 0,17 s) à 100 mL (1,6 ± 0,11 s), tant pour les cigarettes non-allumées que pour les cigarettes allumées. Les volumes de bouffées ont été sousestimés pour les volumes inférieurs de 40 mL (25,6 ± 5,5 mL) à 70 mL (68,8 ± 3,7 mL), à la fois pour les cigarettes non-allumées et allumées et ils ont été légèrement surestimés pour des volumes plus élevés de 85 mL (89,4 ± 7,6 mL) à 100 mL (103,4 ± 9,8 mL) pour les cigarettes allumées. Les résultats expérimentaux ont indiqué qu’un seuil de flux de 12,5-20 mL/s (750-1200 mL/min) pour la reconnaissance des bouffées était responsable des résultats observés. Cette étude confirme l’importance de parfaitement bien comprendre la performance de l’appareil avant d’effectuer des essais cliniques de topographie du fumage humain. [Beitr. Tabakforsch. Int. 26 (2014) 19-25]


Analytical Chemistry | 1983

On-line supercritical fluid chromatography/Fourier transform infrared spectrometry

Kenneth H. Shafer; Peter R. Griffiths


Archive | 2003

Cigarette with smoke constituent attenuator

Kenneth H. Shafer; San Li; Milton E. Parrish; Susan E. Plunkett


Analytical Chemistry | 1986

Supercritical fluid chromatography/Fourier transform infrared spectrometry with an automatic diffuse reflectance interface

Kenneth H. Shafer; Stephen L. Pentoney; Peter R. Griffiths


Journal of Chromatographic Science | 1986

A Solvent Elimination Interface for Capillary Supercritical Fluid Chromatography/Fourier Transform Infrared Spectrometry Using an Infrared Microscope

Stephen L. Pentoney; Kenneth H. Shafer; Peter R. Griffiths


Analytical Chemistry | 2003

Quantum cascade infrared laser spectroscopy for real-time cigarette smoke analysis

Q. Shi; David D. Nelson; J. Barry McManus; Mark S. Zahniser; Milton E. Parrish; Randall E. Baren; Kenneth H. Shafer; Charles N. Harward


Analytical Chemistry | 1986

Sample transfer accessory for thin-layer chromatography/Fourier transform infrared spectrometry

Kenneth H. Shafer; Peter R. Griffiths; Wang Shu-Qin


Analytical Chemistry | 1986

Capillary gas chromatography/Fourier transform infrared microspectrometry at subambient temperature

Roger Fuoco; Kenneth H. Shafer; Peter R. Griffiths


Hrc-journal of High Resolution Chromatography | 1986

Supercritical fluid chromatography/Fourier transform infrared microspectrometry

Stephen L. Pentoney; Kenneth H. Shafer; Peter R. Griffiths; Roger Fuoco

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Aldo Giorgetti

University of California

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