This paper presents the results of a clinical, observational, descriptive study to quantify use patterns electronic cigarette users in their natural environment. Previously published work regarding puff topography has been widely indirect nature, and qualitative rather than quantitative, with exception three studies conducted laboratory environment for limited amounts time. The current quantifies variation puffing behaviors among as well given user throughout course day. Puff characteristics...

Results of an observational, descriptive study quantifying topography characteristics twenty first generation electronic nicotine delivery system users in their natural environment for a one week observation period are presented. The quantifies inter-participant variation puffing between and the intra-participant each user observed during use environment. Puff presented include mean puff duration, flow rate volume participant, along with statistics quantity. Exposure including number vaping...

Understanding exposures and potential health effects of e-cigarettes is complex. Users' puffing behavior, or topography, affects function e-cigarette devices (eg, coil temperature) composition their emissions. Users with different topographies are likely exposed to amounts any harmful potentially constituents (HPHCs). In this study, we compare established cigarette smokers nonestablished smokers. Data measuring topography were collected using a wireless hand-held monitoring device in users'...

From the angular correlation measurements of positron annihilation radiation on cold rolled, polycrystalline Ni purity 99.99% and 99.84% curve-shape parameters S are determined for treating as-deformed annealed samples up to a thickness reduction 90%. The trapping rate positrons can be 15 or 18% dislocations vacancies as well. Using known relations hardening within range 2 specific rates estimated dislocations, μd = 2.9 × 10−15 s−1, vacancies, μv 2.2 s−1. Estimated dislocation densities...

A secondary analysis was conducted using puff topography and salivary cotinine biomarker data from a prior two arm, period cross-over study in the natural environment over 17 days which enrolled 55 Juul electronic cigarette users. The expands upon previously validated behavior-based yield (BBY) quantified aerosol emissions ecig as function of user behavior. Pharmacokinetic Behavior-Based Yield (PkBBY) model is introduced models uptake nicotine into body its subsequent metabolic decay...

This work investigates emissions sampling methods employed for qualitative identification of compounds in e-liquids and their resultant aerosols to assess what capture may be sufficient identify harmful potentially constituents present. Three popular e-liquid flavors (cinnamon, mango, vanilla) were analyzed using gas chromatography-mass spectrometry (GC-MS) the un-puffed state. Each liquid was also machine-puffed under realistic-use flow rate conditions captured two techniques: filter pads...

Electronic Nicotine Delivery Systems (ENDS) offer an alternate means to consume nicotine in a variety of flavored aerosols. Data are needed better understand the impact flavors on use behavior. A natural environment observational study was conducted experienced ENDS users measure effect e-liquid flavor topography and consumption The RIT wPUMTM monitor used record date time puff (flow rate, volume, duration) for every taken by N = 34 participants over course two weeks. All tobacco one week,...

Protocols for testing and reporting emissions of Harmful Potentially Constituents (HPHCs) from electronic cigarettes (e-cigs) are lacking. The premise this study is that multi-path relationships may be developed to describe interactions between product characteristics, use behavior develop appropriate protocols tobacco regulatory compliance testing.This proposes a framework consisting three component terms: HPHC mass concentration, ratio total particulate (TPM) concentration. informs...

Abstract A framework describing the joint effect of user topography behavior and product characteristics one exemplar device on total particulate mass (TPM) aerosol constituent yield delivered to a is presented validated against seven user-specific ‘playback’ emissions observations. pen-style e-cig was used collect across puff flow rates durations spanning range observed in natural environment. Emissions were analyzed with GC-MS construct empirical correlations for TPM concentration nicotine...

Introduction: The extent to which electronic cigarette users will compensate for lower nicotine eliquids has implications on the risk associated with regulating eliquid composition. This article elucidates topography as a compensatory mechanism by investigating impact of strength total particulate matter (TPM) and consumed per puff.Methods: Thirty-three experienced vape pen were assigned an NJOY™ VapePen AVAIL™ brand Tobacco Row their usual (L = 6 mg/mL, M 12 H 18 mg/mL) vaped through RIT's...

Abstract Educational settings tend to provide highly specialized contexts for learning. In contrast, workplaces are increasingly multidisciplinary, presenting challenges often not considered in the technical communication curriculum. Our program is addressing this issue by building partnerships with programs mechanical engineering and industrial engineering. article, we discuss a study of our initial semester matching students teams engineers capstone, client-based design course. We focus on...

Abstract A method for analysis of multidimensional steady-state inverse heat conduction problems is presented. The employs an adjoint formulation to approximate a set sensitivity coefficients that relate temperature and flux observations unknown surface conditions. resulting nonsquare system equations regularized subsequently solved in least-squares sense. technique presented evaluating the accuracy estimated conditions terms resolution variance. applied example two dimensions cases which...

The one-dimensional nonlinear problem of heat conduction is considered. A noniterative space-marching finite-difference algorithm developed to estimate the surface temperature and flux from measurements at subsurface locations. trade-off between resolution variance estimates conditions discussed quantitatively. inverse stabilized through use digital filters applied recursively. effect on quantified. Results are presented which indicate that technique capable handling noisy measurement data.

The one-dimensional linear inverse problem of heat conduction is considered. An initial value technique developed which solves the without need for iteration. Simultaneous estimates surface temperature and flux histories are obtained from measurements taken at a subsurface location. Past future measurement times inherently used in analysis. tradeoff that exists between resolution variance conditions discussed quantitatively. A stabilizing matrix introduced to analysis, its effect on...

Delivery of nicotine and substances from electronic delivery systems, or e-cigarettes, depends in part on how users puff the devices. Little is known about variation puffing behavior to inform testing protocols understand whether behaviors result increased exposure emissions.We analyzed topography data collected using a wireless portable use monitor (wPUM) continuously over 2 weeks among 34 current second-generation e-cigarette their everyday lives. For each puff, wPUM recorded date, time,...

Standardized topography protocols for testing cigarette emissions include the Federal Trade Commission/International Standard Organization (FTC/ISO), Massachusetts Department of Health (MDPH), and Canada (HC). Data are lacking how well these represent actual use behavior. This study aims to compare puff protocol standards measured in natural environments across a range brands. Current smokers between 18 65 years age were recruited. Each participant was provided with wPUM™ monitor instructed...

Background: Natural environment inhalation topography provides useful information for toxicant exposure, risk assessment and cardiopulmonary performance. Commercially available wearable respiratory monitors (WRMs), which are currently used to measure a variety of physiological parameters such as heart rate breathing frequency, can be leveraged obtain topography, yet little work has been done. This paper assesses the feasibility adapting these WRMs measuring topography. Methods: were compiled...

Many Electronic Nicotine Delivery Systems (ENDS) employ integrated sensors to detect user puffing behavior and activate the heating coil initiate aerosol generation. The minimum puff flow rate duration at which ENDS device begins generate are important parameters in quantifying viable operating envelope of essential formulating a design experiments for comprehensive emissions characterization. An accurate unbiased method condition is needed quantify product characteristics across research...

This study introduces and demonstrates a comprehensive, accurate, unbiased approach to robust quantitative comparison of electronic nicotine delivery systems (ENDS) appropriate for establishing substantial equivalence (or lack thereof) between inhaled products. The is demonstrated across family thirteen pen- pod-style ENDS Methods employed consist formulating emissions surface regression model, quantifying the empirical accuracy model as applied each product, evaluating relationships product...

Abstract Current in vitro emissions and exposure systems lack biomimicry, use unrealistic flow conditions, produce dose, provide inaccurate biomechanical cues to cell cultures, limiting ability correlate outcomes with vivo health effects. A biomimetic system capable of puffing aerosol clean air inhalation may empower researchers investigate complex questions related lung injury disease. (BAES), including an electronic cigarette adapter, oral cavity module (OCM), bifurcated chamber (BEC) was...

Abstract High dose oxygen ion implantation into silicon at 30 keV was performed to produce understoichiometric and stoichiometric surface oxide layers of ∼160 nm thickness. The depth profile stoichiometry determined by RBS XPS. SiO compound formation found IR spectroscopy XPS in the unannealed samples as well after target heating, furnace or flash lamp annealing. As implanted consist random bonding like SiO x (O < 2), demixing Si 2 Unannealed are bond strained . activation energies...