Does e-cigarette consumption cause passive vaping?

PubMed

Schripp, T; Markewitz, D; Uhde, E; Salthammer, T

2013-02-01

Electronic cigarette consumption ('vaping') is marketed as an alternative to conventional tobacco smoking. Technically, a mixture of chemicals containing carrier liquids, flavors, and optionally nicotine is vaporized and inhaled. The present study aims at the determination of the release of volatile organic compounds (VOC) and (ultra)fine particles (FP/UFP) from an e-cigarette under near-to-real-use conditions in an 8-m(3) emission test chamber. Furthermore, the inhaled mixture is analyzed in small chambers. An increase in FP/UFP and VOC could be determined after the use of the e-cigarette. Prominent components in the gas-phase are 1,2-propanediol, 1,2,3-propanetriol, diacetin, flavorings, and traces of nicotine. As a consequence, 'passive vaping' must be expected from the consumption of e-cigarettes. Furthermore, the inhaled aerosol undergoes changes in the human lung that is assumed to be attributed to deposition and evaporation. The consumption of e-cigarettes marks a new source for chemical and aerosol exposure in the indoor environment. To evaluate the impact of e-cigarettes on indoor air quality and to estimate the possible effect of passive vaping, information about the chemical characteristics of the released vapor is needed. © 2012 John Wiley & Sons A/S.

Automation of the in vitro micronucleus and chromosome aberration assay for the assessment of the genotoxicity of the particulate and gas-vapor phase of cigarette smoke.

PubMed

Roemer, Ewald; Zenzen, Volker; Conroy, Lynda L; Luedemann, Kathrin; Dempsey, Ruth; Schunck, Christian; Sticken, Edgar Trelles

2015-01-01

Total particulate matter (TPM) and the gas-vapor phase (GVP) of mainstream smoke from the Reference Cigarette 3R4F were assayed in the cytokinesis-block in vitro micronucleus (MN) assay and the in vitro chromosome aberration (CA) assay, both using V79-4 Chinese hamster lung fibroblasts exposed for up to 24 h. The Metafer image analysis platform was adapted resulting in a fully automated evaluation system of the MN assay for the detection, identification and reporting of cells with micronuclei together with the determination of the cytokinesis-block proliferation index (CBPI) to quantify the treatment-related cytotoxicity. In the CA assay, the same platform was used to identify, map and retrieve metaphases for a subsequent CA evaluation by a trained evaluator. In both the assays, TPM and GVP provoked a significant genotoxic effect: up to 6-fold more micronucleated target cells than in the negative control and up to 10-fold increases in aberrant metaphases. Data variability was lower in the automated version of the MN assay than in the non-automated. It can be estimated that two test substances that differ in their genotoxicity by approximately 30% can statistically be distinguished in the automated MN and CA assays. Time savings, based on man hours, due to the automation were approximately 70% in the MN and 25% in the CA assays. The turn-around time of the evaluation phase could be shortened by 35 and 50%, respectively. Although only cigarette smoke-derived test material has been applied, the technical improvements should be of value for other test substances.

Flavoring Chemicals and Aldehydes in E-Cigarette Emissions.

PubMed

Klager, Skylar; Vallarino, Jose; MacNaughton, Piers; Christiani, David C; Lu, Quan; Allen, Joseph G

2017-09-19

Regulations on e-cigarettes in the U.S. do not provide guidelines on the chemical content of e-cigarette liquids. We evaluated emissions of aldehydes and flavoring chemicals in e-cigarette vapor under typical usage conditions. We selected 24 e-cigarette flavors from the top selling disposable e-cigarette brands. E-cigarettes were connected to a pump drawing air for two second puffs with sixty-second intervals between puffs. The vapor was analyzed for the presence of aldehydes using high-performance liquid chromatography-ultraviolet detector and for the presence of flavoring chemicals with gas chromatography and an electron capture detector. All e-cigarette emissions tested contained at least one aldehyde and/or flavoring chemical on either the FEMA "High Priority Chemicals" or FDA Harmful and Potentially Harmful Constituents lists when sampled at typical usage conditions. Diacetyl, a known respiratory hazard, along with acetoin, were the most prevalent of the flavoring chemicals in e-cigarette vapor, being found in more than 60% of samples. The presence of propionaldehyde, acetaldehyde and formaldehyde were correlated, corroborating previous work suggesting thermal degradation as a pathway for aldehyde generation in e-cigarette vapors. Median formaldehyde concentrations of 626 μg/m 3 in e-cigarette vapor exceed the ACGIH maximum concentrations allowable for workers of 370 μg/m 3 .

Numerical simulation of the effects of dilution level, depth of inhalation, and smoke composition on nicotine vapor deposition during cigarette smoking.

PubMed

Ingebrethsen, Bradley J

2006-12-01

A numerical model of an aerosol containing vaporizable nicotine depositing to the walls of a tube was developed and applied to simulate the vapor deposition of nicotine in a denuder tube and under conditions approximating those in the respiratory tract during mainstream cigarette smoke inhalation. The numerical model was validated by comparison to data for denuder tube collection of nicotine from the smoke of three types of cigarette differing in smoke acidity and nicotine volatility. Simulations predict that the absorption of water by aerosol particles inhibits nicotine vapor deposition to tube walls, and that increased temperature, decreased tube diameter, and increased dilution enhance nicotine vapor deposition rate. The combined effect of changing these four parameters to approximate the transition from conducting to gas exchange regions of the respiratory tract was a significant net increase in predicted nicotine vapor deposition rate. Comparisons of nicotine deposition rates between conditions in the conducting airways and those in the gas exchange region were informative with regard to reported nicotine retention measurements during human smoking. Reports that vaporizable nicotine can penetrate past the conducting airways, that nicotine can be retained at near 100% efficiency from mainstream smoke, and that cigarettes with differing acidity and nicotine volatility have similar nicotine uptake rates are all shown to be consistent with the results of the model simulations.

Phase transformations during the growth of paracetamol crystals from the vapor phase

NASA Astrophysics Data System (ADS)

Belyaev, A. P.; Rubets, V. P.; Antipov, V. V.; Bordei, N. S.

2014-07-01

Phase transformations during the growth of paracetamol crystals from the vapor phase are studied by differential scanning calorimetry. It is found that the vapor-crystal phase transition is actually a superposition of two phase transitions: a first-order phase transition with variable density and a second-order phase transition with variable ordering. The latter, being a diffuse phase transition, results in the formation of a new, "pretransition," phase irreversibly spent in the course of the transition, which ends in the appearance of orthorhombic crystals. X-ray diffraction data and micrograph are presented.

Vapor Phase Deposition Using Plasma Spray-PVD™

NASA Astrophysics Data System (ADS)

von Niessen, K.; Gindrat, M.; Refke, A.

2010-01-01

Plasma spray—physical vapor deposition (PS-PVD) is a low pressure plasma spray technology to deposit coatings out of the vapor phase. PS-PVD is a part of the family of new hybrid processes recently developed by Sulzer Metco AG (Switzerland) on the basis of the well-established low pressure plasma spraying (LPPS) technology. Included in this new process family are plasma spray—chemical vapor deposition (PS-CVD) and plasma spray—thin film (PS-TF) processes. In comparison to conventional vacuum plasma spraying and LPPS, these new processes use a high energy plasma gun operated at a work pressure below 2 mbar. This leads to unconventional plasma jet characteristics which can be used to obtain specific and unique coatings. An important new feature of PS-PVD is the possibility to deposit a coating not only by melting the feed stock material which builds up a layer from liquid splats, but also by vaporizing the injected material. Therefore, the PS-PVD process fills the gap between the conventional PVD technologies and standard thermal spray processes. The possibility to vaporize feedstock material and to produce layers out of the vapor phase results in new and unique coating microstructures. The properties of such coatings are superior to those of thermal spray and EB-PVD coatings. This paper reports on the progress made at Sulzer Metco to develop functional coatings build up from vapor phase of oxide ceramics and metals.

Method for the Determination of Ammonia in Mainstream Cigarette Smoke Using Ion Chromatography

PubMed Central

Watson, Christina Vaughan; Feng, June; Valentin-Blasini, Liza; Stanelle, Rayman; Watson, Clifford H.

2016-01-01

Ammonia in mainstream smoke is present in both the particulate and vapor phases. The presence of ammonia in the cigarette filler material and smoke is of significance because of the potential role ammonia could have in raising the “smoke pH.” An increased smoke pH could shift a fraction of total nicotine to free-base nicotine, which is reportedly more rapidly absorbed by the smoker. Methods measuring ammonia in smoke typically employ acid filled impingers to trap the smoke. We developed a fast, reliable method to measure ammonia in mainstream smoke without the use of costly and time consuming impingers to examine differences in ammonia delivery. The method uses both a Cambridge filter pad and a Tedlar bag to capture particulate and vapor phases of the smoke. We quantified ammonia levels in the mainstream smoke of 50 cigarette brands from 5 manufacturers. Ammonia levels ranged from approximately 1μg to 23μg per cigarette for ISO smoking conditions and 38μg to 67μg per cigarette for Canadian intense smoking conditions and statistically significance differences were observed between brands and manufacturers. Our findings suggest that ammonia levels vary by brand and are higher under Canadian intense smoking conditions. PMID:27415766

Simultaneous Analysis of 22 Volatile Organic Compounds in Cigarette Smoke Using Gas Sampling Bags for High-Throughput Solid-Phase Microextraction

PubMed Central

Sampson, Maureen M.; Chambers, David M.; Pazo, Daniel Y.; Moliere, Fallon; Blount, Benjamin C.; Watson, Clifford H.

2015-01-01

Quantifying volatile organic compounds (VOCs) in cigarette smoke is necessary to establish smoke-related exposure estimates and evaluate emerging products and potential reduced-exposure products. In response to this need, we developed an automated, multi-VOC quantification method for machine-generated, mainstream cigarette smoke using solidphase microextraction gas chromatography–mass spectrometry (SPME-GC–MS). This method was developed to simultaneously quantify a broad range of smoke VOCs (i.e., carbonyls and volatiles, which historically have been measured by separate assays) for large exposure assessment studies. Our approach collects and maintains vapor-phase smoke in a gas sampling bag, where it is homogenized with isotopically labeled analogue internal standards and sampled using gas-phase SPME. High throughput is achieved by SPME automation using a CTC Analytics platform and custom bag tray. This method has successfully quantified 22 structurally diverse VOCs (e.g., benzene and associated monoaromatics, aldehydes and ketones, furans, acrylonitrile, 1,3-butadiene, vinyl chloride, and nitromethane) in the microgram range in mainstream smoke from 1R5F and 3R4F research cigarettes smoked under ISO (Cambridge Filter or FTC) and Intense (Health Canada or Canadian Intense) conditions. Our results are comparable to previous studies with few exceptions. Method accuracy was evaluated with third-party reference samples (≤15% error). Short-term diffusion losses from the gas sampling bag were minimal, with a 10% decrease in absolute response after 24 h. For most analytes, research cigarette inter- and intrarun precisions were ≤20% relative standard deviation (RSD). This method provides an accurate and robust means to quantify VOCs in cigarette smoke spanning a range of yields that is sufficient to characterize smoke exposure estimates. PMID:24933649

Are E-cigarettes a safe and good alternative to cigarette smoking?

PubMed

Rom, Oren; Pecorelli, Alessandra; Valacchi, Giuseppe; Reznick, Abraham Z

2015-03-01

Electronic cigarettes (E-cigarettes) are devices that can vaporize a nicotine solution combined with liquid flavors instead of burning tobacco leaves. Since their emergence in 2004, E-cigarettes have become widely available, and their use has increased exponentially worldwide. E-cigarettes are aggressively advertised as a smoking cessation aid; as healthier, cheaper, and more socially acceptable than conventional cigarettes. In recent years, these claims have been evaluated in numerous studies. This review explores the development of the current E-cigarette and its market, prevalence of awareness, and use. The review also explores the beneficial and adverse effects of E-cigarettes in various aspects in accordance with recent research. The discussed aspects include smoking cessation or reduction and the health risks, social impact, and environmental consequences of E-cigarettes. © 2014 New York Academy of Sciences.

E-Cigarettes and "Dripping" Among High-School Youth.

PubMed

Krishnan-Sarin, Suchitra; Morean, Meghan; Kong, Grace; Bold, Krysten W; Camenga, Deepa R; Cavallo, Dana A; Simon, Patricia; Wu, Ran

2017-03-01

Electronic cigarettes (e-cigarettes) electrically heat and vaporize e-liquids to produce inhalable vapors. These devices are being used to inhale vapors produced by dripping e-liquids directly onto heated atomizers. The current study conducts the first evaluation of the prevalence rates and reasons for using e-cigarettes for dripping among high school students. In the spring of 2015, students from 8 Connecticut high schools ( n = 7045) completed anonymous surveys that examined tobacco use behaviors and perceptions. We assessed prevalence rates of ever using e-cigarettes for dripping, reasons for dripping, and predictors of dripping behaviors among those who reported ever use of e-cigarettes. Among 1080 ever e-cigarette users, 26.1% of students reported ever using e-cigarettes for dripping. Reasons for dripping included produced thicker clouds of vapor (63.5%), made flavors taste better (38.7%), produced a stronger throat hit (27.7%), curiosity (21.6%), and other (7.5%). Logistic regression analyses indicated that male adolescents (odds ratio [OR] = 1.64), whites (OR = 1.46), and those who had tried multiple tobacco products (OR = 1.34) and had greater past-month e-cigarette use frequency (OR = 1.07) were more likely to use dripping ( P s < .05). These findings indicate that a substantial portion (∼1 in 4) of high school adolescents who had ever used e-cigarettes also report using the device for dripping. Future efforts must examine the progression and toxicity of the use of e-cigarettes for dripping among youth and educate them about the potential dangers of these behaviors. Copyright © 2017 by the American Academy of Pediatrics.

Flavoring Compounds Dominate Toxic Aldehyde Production during E-Cigarette Vaping.

PubMed

Khlystov, Andrey; Samburova, Vera

2016-12-06

The growing popularity of electronic cigarettes (e-cigarettes) raises concerns about the possibility of adverse health effects to primary users and people exposed to e-cigarette vapors. E-Cigarettes offer a very wide variety of flavors, which is one of the main factors that attract new, especially young, users. How flavoring compounds in e-cigarette liquids affect the chemical composition and toxicity of e-cigarette vapors is practically unknown. Although e-cigarettes are marketed as safer alternatives to traditional cigarettes, several studies have demonstrated formation of toxic aldehydes in e-cigarette vapors during vaping. So far, aldehyde formation has been attributed to thermal decomposition of the main components of e-cigarette e-liquids (propylene glycol and glycerol), while the role of flavoring compounds has been ignored. In this study, we have measured several toxic aldehydes produced by three popular brands of e-cigarettes with flavored and unflavored e-liquids. We show that, within the tested e-cigarette brands, thermal decomposition of flavoring compounds dominates formation of aldehydes during vaping, producing levels that exceed occupational safety standards. Production of aldehydes was found to be exponentially dependent on concentration of flavoring compounds. These findings stress the need for a further, thorough investigation of the effect of flavoring compounds on the toxicity of e-cigarettes.

Carbonyl compounds in electronic cigarette vapors: effects of nicotine solvent and battery output voltage.

PubMed

Kosmider, Leon; Sobczak, Andrzej; Fik, Maciej; Knysak, Jakub; Zaciera, Marzena; Kurek, Jolanta; Goniewicz, Maciej Lukasz

2014-10-01

Glycerin (VG) and propylene glycol (PG) are the most common nicotine solvents used in e-cigarettes (ECs). It has been shown that at high temperatures both VG and PG undergo decomposition to low molecular carbonyl compounds, including the carcinogens formaldehyde and acetaldehyde. The aim of this study was to evaluate how various product characteristics, including nicotine solvent and battery output voltage, affect the levels of carbonyls in EC vapor. Twelve carbonyl compounds were measured in vapors from 10 commercially available nicotine solutions and from 3 control solutions composed of pure glycerin, pure propylene glycol, or a mixture of both solvents (50:50). EC battery output voltage was gradually modified from 3.2 to 4.8V. Carbonyl compounds were determined using the HPLC/DAD method. Formaldehyde and acetaldehyde were found in 8 of 13 samples. The amounts of formaldehyde and acetaldehyde in vapors from lower voltage EC were on average 13- and 807-fold lower than in tobacco smoke, respectively. The highest levels of carbonyls were observed in vapors generated from PG-based solutions. Increasing voltage from 3.2 to 4.8V resulted in a 4 to more than 200 times increase in formaldehyde, acetaldehyde, and acetone levels. The levels of formaldehyde in vapors from high-voltage device were in the range of levels reported in tobacco smoke. Vapors from EC contain toxic and carcinogenic carbonyl compounds. Both solvent and battery output voltage significantly affect levels of carbonyl compounds in EC vapors. High-voltage EC may expose users to high levels of carbonyl compounds. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Knowledge about chemicals in e-cigarette secondhand vapor and perceived harms of exposure among a national sample of U.S. adults

PubMed Central

Tan, Andy SL; Mello, Susan; Sanders-Jackson, Ashley; Bigman, Cabral A.

2017-01-01

Potentially harmful chemicals are detectable in e-cigarette secondhand vapor (hereafter SHV), contrary to advertising and marketing claims that it contains “only water vapor.” We assessed public knowledge about the presence of chemicals in SHV and associations between knowledge and perceived harms of exposure to SHV. We conducted an online survey of a nationally representative sample of 1449 U.S. adults (GfK's KnowledgePanel) from October-December 2013. Respondents were asked whether e-cigarette vapor contains only water vapor, contains tar, or contains formaldehyde (true/ false/ don't know). Responses to these three items were recoded (1=incorrect, 2=don't know, 3=correct) and averaged into a knowledge scale. They were also asked if they perceived breathing SHV to be harmful to one's health (two-item scale) and comparative harm of breathing SHV versus breathing secondhand smoke (SHS). Multiple regression analyses were weighted to the U.S. adult population and adjusted for potential confounders. Most respondents (58-75%) reported not knowing whether SHV contained only water vapor, if SHV contained tar, and if it contained formaldehyde. African-American respondents (versus white) and current smokers (versus non-smokers) had lower levels of knowledge about chemicals in SHV. Adjusting for covariates, correct knowledge about chemicals in SHV was associated with higher perceived harms about SHV for one's health and perceived comparative harm of SHV versus SHS. These findings suggest a need to provide accurate information about the presence of chemicals in SHV (e.g., using product ingredient labels or public education). PMID:27595498

Knowledge about Chemicals in e-Cigarette Secondhand Vapor and Perceived Harms of Exposure among a National Sample of U.S. Adults.

PubMed

Tan, Andy S L; Mello, Susan; Sanders-Jackson, Ashley; Bigman, Cabral A

2017-06-01

Potentially harmful chemicals are detectable in e-cigarette secondhand vapor (hereafter SHV), contrary to advertising and marketing claims that it contains "only water vapor." We assessed public knowledge about the presence of chemicals in SHV and associations between knowledge and perceived harms of exposure to SHV. We conducted an online survey of a nationally representative sample of 1,449 U.S. adults (GfK's KnowledgePanel) from October to December 2013. Respondents were asked whether e-cigarette vapor contains only water vapor, contains tar, or contains formaldehyde (true/ false/ do not know). Responses to these three items were recoded (1 = incorrect, 2 = do not know, and 3 = correct) and averaged into a knowledge scale. They were also asked if they perceived breathing SHV to be harmful to one's health (two-item scale) and comparative harm of breathing SHV versus breathing secondhand smoke (SHS). Multiple regression analyses were weighted to the U.S. adult population and adjusted for potential confounders. Most respondents (58-75%) reported not knowing whether SHV contained only water vapor, if SHV contained tar, and if it contained formaldehyde. African-American respondents (vs. white) and current smokers (vs. nonsmokers) had lower levels of knowledge about chemicals in SHV. Adjusting for covariates, correct knowledge about chemicals in SHV was associated with higher perceived harms about SHV for one's health and perceived comparative harm of SHV versus SHS. These findings suggest a need to provide accurate information about the presence of chemicals in SHV (e.g., using product ingredient labels or public education). © 2016 Society for Risk Analysis.

Vapor-liquid phase separator studies

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Lee, J. M.; Kim, Y. I.; Hepler, W. A.; Frederking, T. H. K.

1983-01-01

Porous plugs serve as both entropy rejection devices and phase separation components separating the vapor phase on the downstream side from liquid Helium 2 upstream. The liquid upstream is the cryo-reservoir fluid needed for equipment cooling by means of Helium 2, i.e Helium-4 below its lambda temperature in near-saturated states. The topics outlined are characteristic lengths, transport equations and plug results.

Electronic cigarette inhalation alters innate immunity and airway cytokines while increasing the virulence of colonizing bacteria.

PubMed

Hwang, John H; Lyes, Matthew; Sladewski, Katherine; Enany, Shymaa; McEachern, Elisa; Mathew, Denzil P; Das, Soumita; Moshensky, Alexander; Bapat, Sagar; Pride, David T; Ongkeko, Weg M; Crotty Alexander, Laura E

2016-06-01

Electronic (e)-cigarette use is rapidly rising, with 20 % of Americans ages 25-44 now using these drug delivery devices. E-cigarette users expose their airways, cells of host defense, and colonizing bacteria to e-cigarette vapor (EV). Here, we report that exposure of human epithelial cells at the air-liquid interface to fresh EV (vaped from an e-cigarette device) resulted in dose-dependent cell death. After exposure to EV, cells of host defense-epithelial cells, alveolar macrophages, and neutrophils-had reduced antimicrobial activity against Staphylococcus aureus (SA). Mouse inhalation of EV for 1 h daily for 4 weeks led to alterations in inflammatory markers within the airways and elevation of an acute phase reactant in serum. Upon exposure to e-cigarette vapor extract (EVE), airway colonizer SA had increased biofilm formation, adherence and invasion of epithelial cells, resistance to human antimicrobial peptide LL-37, and up-regulation of virulence genes. EVE-exposed SA were more virulent in a mouse model of pneumonia. These data suggest that e-cigarettes may be toxic to airway cells, suppress host defenses, and promote inflammation over time, while also promoting virulence of colonizing bacteria. Acute exposure to e-cigarette vapor (EV) is cytotoxic to airway cells in vitro. Acute exposure to EV decreases macrophage and neutrophil antimicrobial function. Inhalation of EV alters immunomodulating cytokines in the airways of mice. Inhalation of EV leads to increased markers of inflammation in BAL and serum. Staphylococcus aureus become more virulent when exposed to EV.

E-cigarettes: methodological and ideological issues and research priorities.

PubMed

Etter, Jean-François

2015-02-16

Cigarette combustion, rather than either tobacco or nicotine, is the cause of a public health disaster. Fortunately, several new technologies that vaporize nicotine or tobacco, and may make cigarettes obsolete, have recently appeared. Research priorities include the effects of vaporizers on smoking cessation and initiation, their safety and toxicity, use by non-smokers, dual use of vaporizers and cigarettes, passive vaping, renormalization of smoking, and the development of messages that effectively communicate the continuum of risk for tobacco and nicotine products. A major difficulty is that we are chasing a moving target. New products constantly appear, and research results are often obsolete by the time they are published. Vaporizers do not need to be safe, only safer than cigarettes. However, harm reduction principles are often misunderstood or rejected. In the context of a fierce ideological debate, and major investments by the tobacco industry, it is crucial that independent researchers provide regulators and the public with evidence-based guidance. The methodological and ideological hurdles on this path are discussed in this commentary.

Thermodynamic considerations of the vapor phase reactions in III-nitride metal organic vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Sekiguchi, Kazuki; Shirakawa, Hiroki; Chokawa, Kenta; Araidai, Masaaki; Kangawa, Yoshihiro; Kakimoto, Koichi; Shiraishi, Kenji

2017-04-01

We analyzed the metal organic vapor phase epitaxial growth mechanism of the III-nitride semiconductors GaN, AlN, and InN by first-principles calculations and thermodynamic analyses. In these analyses, we investigated the decomposition processes of the group III source gases X(CH3)3 (X = Ga, Al, In) at finite temperatures and determined whether the (CH3)2GaNH2 adduct can be formed or not. The results of our calculations show that the (CH3)2GaNH2 adduct cannot be formed in the gas phase in GaN metal organic vapor phase epitaxy (MOVPE), whereas, in AlN MOVPE, the formation of the (CH3)2AlNH2 adduct in the gas phase is exclusive. In the case of GaN MOVPE, trimethylgallium (TMG, [Ga(CH3)3]) decomposition into Ga gas on the growth surface with the assistance of H2 carrier gas, instead of the formation of the (CH3)2GaNH2 adduct, occurs almost exclusively. Moreover, in the case of InN MOVPE, the formation of the (CH3)2InNH2 adduct does not occur and it is relatively easy to produce In gas even without H2 in the carrier gas.

Water vapor radiometry research and development phase

NASA Technical Reports Server (NTRS)

Resch, G. M.; Chavez, M. C.; Yamane, N. L.; Barbier, K. M.; Chandlee, R. C.

1985-01-01

This report describes the research and development phase for eight dual-channel water vapor radiometers constructed for the Crustal Dynamics Project at the Goddard Space Flight Center, Greenbelt, Maryland, and for the NASA Deep Space Network. These instruments were developed to demonstrate that the variable path delay imposed on microwave radio transmissions by atmospheric water vapor can be calibrated, particularly as this phenomenon affects very long baseline interferometry measurement systems. Water vapor radiometry technology can also be used in systems that involve moist air meteorology and propagation studies.

A protocol for detecting and scavenging gas-phase free radicals in mainstream cigarette smoke.

PubMed

Yu, Long-Xi; Dzikovski, Boris G; Freed, Jack H

2012-01-02

Cigarette smoking is associated with human cancers. It has been reported that most of the lung cancer deaths are caused by cigarette smoking (5,6,7,12). Although tobacco tars and related products in the particle phase of cigarette smoke are major causes of carcinogenic and mutagenic related diseases, cigarette smoke contains significant amounts of free radicals that are also considered as an important group of carcinogens(9,10). Free radicals attack cell constituents by damaging protein structure, lipids and DNA sequences and increase the risks of developing various types of cancers. Inhaled radicals produce adducts that contribute to many of the negative health effects of tobacco smoke in the lung(3). Studies have been conducted to reduce free radicals in cigarette smoke to decrease risks of the smoking-induced damage. It has been reported that haemoglobin and heme-containing compounds could partially scavenge nitric oxide, reactive oxidants and carcinogenic volatile nitrosocompounds of cigarette smoke(4). A 'bio-filter' consisted of haemoglobin and activated carbon was used to scavenge the free radicals and to remove up to 90% of the free radicals from cigarette smoke(14). However, due to the cost-ineffectiveness, it has not been successfully commercialized. Another study showed good scavenging efficiency of shikonin, a component of Chinese herbal medicine(8). In the present study, we report a protocol for introducing common natural antioxidant extracts into the cigarette filter for scavenging gas phase free radicals in cigarette smoke and measurement of the scavenge effect on gas phase free radicals in mainstream cigarette smoke (MCS) using spin-trapping Electron Spin Resonance (ESR) Spectroscopy(1,2,14). We showed high scavenging capacity of lycopene and grape seed extract which could point to their future application in cigarette filters. An important advantage of these prospective scavengers is that they can be obtained in large quantities from byproducts of

Melt-Vapor Phase Diagram of the Te-S System

NASA Astrophysics Data System (ADS)

Volodin, V. N.; Trebukhov, S. A.; Kenzhaliyev, B. K.; Nitsenko, A. V.; Burabaeva, N. M.

2018-03-01

The values of partial pressure of saturated vapor of the constituents of the Te-S system are determined from boiling points. The boundaries of the melt-vapor phase transition at atmospheric pressure and in vacuum of 2000 and 100 Pa are calculated on the basis of partial pressures. A phase diagram that includes vapor-liquid equilibrium fields whose boundaries allow us to assess the behavior of elements upon distillation fractioning is plotted. It is established that the separation of elements is possible at the first evaporation-condensation cycle. Complications can be caused by crystallization of a sulfur solid solution in tellurium.

E-cigarettes: Considerations for the otolaryngologist.

PubMed

Biyani, Sneh; Derkay, Craig S

2015-08-01

To review the literature regarding electronic cigarettes and discuss potential implications and need for advocacy for the pediatric otolaryngologist. Electronic cigarettes (e-cigarettes) are battery-operated devices that deliver nicotine-containing vapors via inhalation. Research on the health related consequences of e-cigarettes is ongoing and safety has yet to be established. E-cigarettes are not presently under the regulation of any national governing body with wide accessibility to minors. Use of these products has substantially increased since arrival to the market, particularly within the adolescent population. These products are marketed via various platforms including television, Internet and social media. Hundreds of flavors are offered and e-cigarettes are packaged in various colors. Not only are the ill health effects and addictive quality of nicotine concerning, these products have the potential to serve as a gateway for minors to tobacco use. The relationship between tobacco use, secondhand smoke exposure and otolaryngology specific diseases has well been defined. As use of electronic cigarettes increases, pediatric otolaryngologists should be aware of the ongoing literature regarding these products and to be prepared to counsel families accordingly. The use of e-cigarettes among teenagers, potential implications of secondhand vapor exposure from parents and friends, and concerns this may encourage adolescents to utilize conventional tobacco products needs to be considered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Science and electronic cigarettes: current data, future needs.

PubMed

Breland, Alison B; Spindle, Tory; Weaver, Michael; Eissenberg, Thomas

2014-01-01

Electronic cigarettes (ECIGs), also referred to as electronic nicotine delivery systems or "e-cigarettes," generally consist of a power source (usually a battery) and heating element (commonly referred to as an atomizer) that vaporizes a solution (e-liquid). The user inhales the resulting vapor. Electronic cigarettes have been increasing in popularity since they were introduced into the US market in 2007. Many questions remain about these products, and limited research has been conducted. This review describes the available research on what ECIGs are, effects of use, survey data on awareness and use, and the utility of ECIGs to help smokers quit using tobacco cigarettes. This review also describes arguments for and against ECIGs and concludes with steps to move research on ECIGs forward.

Application of Thioether for Vapor Phase Lubrication

NASA Technical Reports Server (NTRS)

Graham, E. Earl

1997-01-01

The objective of these studies was to identify the optimal conditions for vapor phase lubrication using Thioether for both sliding and rolling wear. The important variable include; (1) The component materials including M50 steel, monel and silicon nitride. (2) The vapor concentration and flow rate. (3) The temperature in the range of 600 F to 1500 F. (4) The loads and rolling and/or sliding speeds.

Inhaled delivery of Δ(9)-tetrahydrocannabinol (THC) to rats by e-cigarette vapor technology.

PubMed

Nguyen, Jacques D; Aarde, Shawn M; Vandewater, Sophia A; Grant, Yanabel; Stouffer, David G; Parsons, Loren H; Cole, Maury; Taffe, Michael A

2016-10-01

Most human Δ(9)-tetrahydrocannabinol (THC) use is via inhalation, and yet few animal studies of inhalation exposure are available. Popularization of non-combusted methods for the inhalation of psychoactive drugs (Volcano(®), e-cigarettes) further stimulates a need for rodent models of this route of administration. This study was designed to develop and validate a rodent chamber suitable for controlled exposure to vaporized THC in a propylene glycol vehicle, using an e-cigarette delivery system adapted to standard size, sealed rat housing chambers. The in vivo efficacy of inhaled THC was validated using radiotelemetry to assess body temperature and locomotor responses, a tail-flick assay for nociception and plasma analysis to verify exposure levels. Hypothermic responses to inhaled THC in male rats depended on the duration of exposure and the concentration of THC in the vehicle. The temperature nadir was reached after ∼40 min of exposure, was of comparable magnitude (∼3 °Celsius) to that produced by 20 mg/kg THC, i.p. and resolved within 3 h (compared with a 6 h time course following i.p. THC). Female rats were more sensitive to hypothermic effects of 30 min of lower-dose THC inhalation. Male rat tail-flick latency was increased by THC vapor inhalation; this effect was blocked by SR141716 pretreatment. The plasma THC concentration after 30 min of inhalation was similar to that produced by 10 mg/kg THC i.p. This approach is flexible, robust and effective for use in laboratory rats and will be of increasing utility as users continue to adopt "vaping" for the administration of cannabis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Smokers' and E-Cigarette Users' Perceptions about E-Cigarette Warning Statements.

PubMed

Wackowski, Olivia A; Hammond, David; O'Connor, Richard J; Strasser, Andrew A; Delnevo, Cristine D

2016-06-30

Cigarette warning labels are important sources of risk information, but warning research for other tobacco products is limited. This study aimed to gauge perceptions about warnings that may be used for e-cigarettes. We conducted six small focus groups in late 2014/early 2015 with adult current e-cigarette users and cigarette-only smokers. Participants rated and discussed their perceptions of six e-cigarette warning statements, and warnings in two existing Vuse and MarkTen e-cigarette ads. Participants were open to e-cigarette warnings and provided the strongest reactions to statements warning that e-liquid/e-vapor or e-cigarettes can be poisonous, contain toxins, or are "not a safe alternative to smoking". However, many also noted that these statements were exaggerated, potentially misleading, and could scare smokers away from reducing their harm by switching to e-cigarettes. Opinions on the Food and Drug Administration's proposed nicotine addiction warning and warnings that e-cigarettes had not been approved for smoking cessation or had unknown health effects were mixed. Participants perceived MarkTen's advertisement warning to be stronger and more noticeable than Vuse's. Care should be taken in developing e-cigarette warnings given their relative recentness and potential for harm reduction compared to other tobacco products. Additional research, including with varied audiences, would be instructive.

Up in Vapor: Exploring the Health Messages of E-Cigarette Advertisements.

PubMed

Willis, Erin; Haught, Matthew J; Morris Ii, David L

2017-03-01

Electronic cigarettes (e-cigarettes) have gained popularity in the United States, and marketers are using advertising to recruit new users to their products. Despite outright bans on traditional cigarette advertisements, e-cigarettes have no specific regulations. This study uses framing theory to explore the themes in e-cigarette advertisements. Also, practical implications are discussed.

Use of electronic cigarettes (e-cigarettes) impairs indoor air quality and increases FeNO levels of e-cigarette consumers.

PubMed

Schober, Wolfgang; Szendrei, Katalin; Matzen, Wolfgang; Osiander-Fuchs, Helga; Heitmann, Dieter; Schettgen, Thomas; Jörres, Rudolf A; Fromme, Hermann

2014-07-01

Despite the recent popularity of e-cigarettes, to date only limited data is available on their safety for both users and secondhand smokers. The present study reports a comprehensive inner and outer exposure assessment of e-cigarette emissions in terms of particulate matter (PM), particle number concentrations (PNC), volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH), carbonyls, and metals. In six vaping sessions nine volunteers consumed e-cigarettes with and without nicotine in a thoroughly ventilated room for two hours. We analyzed the levels of e-cigarette pollutants in indoor air and monitored effects on FeNO release and urinary metabolite profile of the subjects. For comparison, the components of the e-cigarette solutions (liquids) were additionally analyzed. During the vaping sessions substantial amounts of 1,2-propanediol, glycerine and nicotine were found in the gas-phase, as well as high concentrations of PM2.5 (mean 197 μg/m(3)). The concentration of putative carcinogenic PAH in indoor air increased by 20% to 147 ng/m(3), and aluminum showed a 2.4-fold increase. PNC ranged from 48,620 to 88,386 particles/cm(3) (median), with peaks at diameters 24-36 nm. FeNO increased in 7 of 9 individuals. The nicotine content of the liquids varied and was 1.2-fold higher than claimed by the manufacturer. Our data confirm that e-cigarettes are not emission-free and their pollutants could be of health concern for users and secondhand smokers. In particular, ultrafine particles formed from supersaturated 1,2-propanediol vapor can be deposited in the lung, and aerosolized nicotine seems capable of increasing the release of the inflammatory signaling molecule NO upon inhalation. In view of consumer safety, e-cigarettes and nicotine liquids should be officially regulated and labeled with appropriate warnings of potential health effects, particularly of toxicity risk in children. Copyright © 2013 Elsevier GmbH. All rights reserved.

Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines.

PubMed

Yu, Vicky; Rahimy, Mehran; Korrapati, Avinaash; Xuan, Yinan; Zou, Angela E; Krishnan, Aswini R; Tsui, Tzuhan; Aguilera, Joseph A; Advani, Sunil; Crotty Alexander, Laura E; Brumund, Kevin T; Wang-Rodriguez, Jessica; Ongkeko, Weg M

2016-01-01

Evaluate the cytotoxicity and genotoxicity of short- and long-term e-cigarette vapor exposure on a panel of normal epithelial and head and neck squamous cell carcinoma (HNSCC) cell lines. HaCaT, UMSCC10B, and HN30 were treated with nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands for periods ranging from 48 h to 8 weeks. Cytotoxicity was assessed using Annexin V flow cytometric analysis, trypan blue exclusion, and clonogenic assays. Genotoxicity in the form of DNA strand breaks was quantified using the neutral comet assay and γ-H2AX immunostaining. E-cigarette-exposed cells showed significantly reduced cell viability and clonogenic survival, along with increased rates of apoptosis and necrosis, regardless of e-cigarette vapor nicotine content. They also exhibited significantly increased comet tail length and accumulation of γ-H2AX foci, demonstrating increased DNA strand breaks. E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent. Further assessment of the potential carcinogenic effects of e-cigarette vapor is urgently needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines

PubMed Central

Yu, Vicky; Rahimy, Mehran; Korrapati, Avinaash; Xuan, Yinan; Zou, Angela E.; Krishnan, Aswini R.; Tsui, Tzuhan; Aguilera, Joseph A.; Advani, Sunil; Crotty Alexander, Laura E.; Brumund, Kevin T.; Wang-Rodriguez, Jessica

2016-01-01

Objectives Evaluate the cytotoxicity and genotoxicity of short- and long-term e-cigarette vapor exposure on a panel of normal epithelial and head and neck squamous cell carcinoma (HNSCC) cell lines. Materials and Methods HaCaT, UMSCC10B, and HN30 were treated with nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands for periods ranging from 48 hours to 8 weeks. Cytotoxicity was assessed using Annexin V flow cytometric analysis, trypan blue exclusion, and clonogenic assays. Genotoxicity in the form of DNA strand breaks was quantified using the neutral comet assay and γ-H2AX immunostaining. Results E-cigarette-exposed cells showed significantly reduced cell viability and clonogenic survival, along with increased rates of apoptosis and necrosis, regardless of e-cigarette vapor nicotine content. They also exhibited significantly increased comet tail length and accumulation of γ-H2AX foci, demonstrating increased DNA strand breaks. Conclusion E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent. Further assessment of the potential carcinogenic effects of e-cigarette vapor is urgently needed. PMID:26547127

Electronic cigarettes: a review of safety and clinical issues.

PubMed

Weaver, Michael; Breland, Alison; Spindle, Tory; Eissenberg, Thomas

2014-01-01

This clinical case conference discusses 3 cases of patients using electronic cigarettes. Electronic cigarettes, also referred to as electronic nicotine delivery systems or "e-cigarettes," generally consist of a power source (usually a battery) and a heating element (commonly referred to as an atomizer) that vaporize a solution (e-liquid). The user inhales the resulting vapor. E-liquids contain humectants such as propylene glycol and/or vegetable glycerin, flavorings, and usually, but not always, nicotine. Each patient's information is an amalgamation of actual patients and is presented and then followed by a discussion of clinical issues.

Smokers’ and E-Cigarette Users’ Perceptions about E-Cigarette Warning Statements

PubMed Central

Wackowski, Olivia A.; Hammond, David; O’Connor, Richard J.; Strasser, Andrew A.; Delnevo, Cristine D.

2016-01-01

Cigarette warning labels are important sources of risk information, but warning research for other tobacco products is limited. This study aimed to gauge perceptions about warnings that may be used for e-cigarettes. We conducted six small focus groups in late 2014/early 2015 with adult current e-cigarette users and cigarette-only smokers. Participants rated and discussed their perceptions of six e-cigarette warning statements, and warnings in two existing Vuse and MarkTen e-cigarette ads. Participants were open to e-cigarette warnings and provided the strongest reactions to statements warning that e-liquid/e-vapor or e-cigarettes can be poisonous, contain toxins, or are “not a safe alternative to smoking”. However, many also noted that these statements were exaggerated, potentially misleading, and could scare smokers away from reducing their harm by switching to e-cigarettes. Opinions on the Food and Drug Administration’s proposed nicotine addiction warning and warnings that e-cigarettes had not been approved for smoking cessation or had unknown health effects were mixed. Participants perceived MarkTen’s advertisement warning to be stronger and more noticeable than Vuse’s. Care should be taken in developing e-cigarette warnings given their relative recentness and potential for harm reduction compared to other tobacco products. Additional research, including with varied audiences, would be instructive. PMID:27376310

Bacterial chemotaxis along vapor-phase gradients of naphthalene.

PubMed

Hanzel, Joanna; Harms, Hauke; Wick, Lukas Y

2010-12-15

The role of bacterial growth and translocation for the bioremediation of organic contaminants in the vadose zone is poorly understood. Whereas air-filled pores restrict the mobility of bacteria, diffusion of volatile organic compounds in air is more efficient than in water. Past research, however, has focused on chemotactic swimming of bacteria along gradients of water-dissolved chemicals. In this study we tested if and to what extent Pseudomonas putida PpG7 (NAH7) chemotactically reacts to vapor-phase gradients forming above their swimming medium by the volatilization from a spot source of solid naphthalene. The development of an aqueous naphthalene gradient by air-water partitioning was largely suppressed by means of activated carbon in the agar. Surprisingly, strain PpG7 was repelled by vapor-phase naphthalene although the steady state gaseous concentrations were 50-100 times lower than the aqueous concentrations that result in positive chemotaxis of the same strain. It is thus assumed that the efficient gas-phase diffusion resulting in a steady, and possibly toxic, naphthalene flux to the cells controlled the chemotactic reaction rather than the concentration to which the cells were exposed. To our knowledge this is the first demonstration of apparent chemotactic behavior of bacteria in response to vapor-phase effector gradients.

Vapor-phase exchange of perchloroethene between soil and plants

USGS Publications Warehouse

Struckhoff, G.C.; Burken, J.G.; Schumacher, J.G.

2005-01-01

Tree core concentrations of tetrachloroethylene (perchloroethene, PCE) at the Riverfront Superfund Site in New Haven, MO, were found to mimic the profile of soil phase concentrations. The observed soil-tree core relationship was stronger than that of groundwater PCE to tree core concentrations at the same site. Earlier research has shown a direct, linear relationship between tree core and groundwater concentrations of chlorinated solvents and other organics. Laboratory-scale experiments were performed to elucidate this phenomenon, including determining partitioning coefficients of PCE between plant tissues and air and between plant tissues and water, measured to be 8.1 and 49 L/kg, respectively. The direct relationship of soil to tree core PCE concentrations was hypothesized to be caused by diffusion between tree roots and the soil vapor phase in the subsurface. The central findings of this research are discovering the importance of subsurface vapor-phase transfer for VOCs and uncovering a direct relationship between soil vapor-phase chlorinated solvents and uptake rates that impact contaminant translocation from the subsurface and transfer into the atmosphere. ?? 2005 American Chemical Society.

Hierarchical Composites to Reduce N-Nitrosamines in Cigarette Smoke

PubMed Central

Li, Yan Yan; Cao, Yi; Yue, Ming Bo; Yang, Jing; Zhu, Jian Hua

2015-01-01

In order to reduce the harmful constituents in cigarette smoke, two hierarchical composites were synthesized. Based on, zeolites HZSM-5 or NaY fragments were introduced into the synthetic system of mesoporous silica SBA-15 or MCM-41 and assembled with the mesoporous materials. These porous composites combine the advantages of micro- and mesoporous materials, and exhibit higher effects than activated carbon on reducing tobacco specific nitrosamines (TSNA) and some vapor phase compounds in smoke. PMID:28788003

[E-Cigarettes – Friend or Foe?].

PubMed

Russi, Erich W

2015-07-01

Not nicotine, but an abundant amount of toxic chemicals produced by the combustion of tobacco are the cause of well-known health problems. E-cigarette vapor contains no or only minimal quantities of potentially harmful substances. Hence it can be assumed that vaping in adults is much less harmful than smoking of cigarettes. Furthermore, no data exist that e-cigarettes will encourage youngsters to become cigarette smokers. E-cigarette vaping has the potential to reduce the daily number of cigarettes smoked or facilitates cessation of smoking in heavily nicotine-dependent smokers, who keep on smoking despite a structured smoking cessation program. Health professionals should be aware of this type of nicotine substitution, since the controversial discussion is often emotional and not evidence-based.

A public health strategy for e-cigarettes.

PubMed

Schneider, Sven; Diehl, Katharina

2015-07-01

The e-cigarette may present a new and significant Public Health problem: Studies published so far do not seem to indicate that e-cigarette use is just a passing trend. If e-cigarette use is less harmless than it is portrayed in many advertisements, Public Health would do well to start a serious discussion about a suitable prevention policy as soon as possible.The aim of this short paper is to discuss a range of measures designed to prevent e-cigarette consumption.Concretely, we suggest to monitor e-cigarette use, the e-cigarette industry and prevention policies, to implement a vapor-free policy, to develop help to quit e-cigarette use, to inform about the health risks of e-cigarette use, to establish regulations on e-cigarette advertising, promotion and sponsorship, and to introduce taxes on e-cigarettes.

Stand-off detection of vapor phase explosives by resonance enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Ehlerding, Anneli; Johansson, Ida; Wallin, Sara; Östmark, Henric

2010-10-01

Stand-off measurements on nitromethane (NM), 2,4-DNT and 2,4,6-TNT in vapor phase using resonance Raman spectroscopy have been performed. The Raman cross sections for NM, DNT and TNT in vapor phase have been measured in the wavelength range 210-300 nm under laboratory conditions, in order to estimate how large resonance enhancement factors can be achieved for these explosives. The measurements show that the signal is greatly enhanced, up to 250.000 times for 2,4-DNT and 60.000 times for 2,4,6-TNT compared to the non-resonant signal at 532 nm. For NM the resonance enhancement enabled realistic outdoor measurements in vapor phase at 13 m distance. This all indicate a potential for resonance Raman spectroscopy as a stand-off technique for detection of vapor phase explosives.

Nonlinear dynamics of confined thin liquid-vapor bilayer systems with phase change

NASA Astrophysics Data System (ADS)

Kanatani, Kentaro; Oron, Alexander

2011-03-01

We numerically investigate the nonlinear evolution of the interface of a thin liquid-vapor bilayer system confined by rigid horizontal walls from both below and above. The lateral variation of the vapor pressure arising from phase change is taken into account in the present analysis. When the liquid (vapor) is heated (cooled) and gravity acts toward the liquid, the deflection of the interface monotonically grows, leading to a rupture of the vapor layer, whereas nonruptured stationary states are found when the liquid (vapor) is cooled (heated) and gravity acts toward the vapor. In the latter case, vapor-flow-driven convective cells are found in the liquid phase in the stationary state. The average vapor pressure and interface temperature deviate from their equilibrium values once the interface departs from the flat equilibrium state. Thermocapillarity does not have a significant effect near the thermodynamic equilibrium, but becomes important if the system significantly deviates from it.

E-cigarettes: a rapidly growing Internet phenomenon.

PubMed

Yamin, Cyrus K; Bitton, Asaf; Bates, David W

2010-11-02

Electronic cigarettes (e-cigarettes) aerosolize nicotine and produce a vapor that emulates that of cigarettes but purportedly has fewer traditional toxins than secondhand smoke. Although e-cigarettes are widely sold online and by retailers, new research suggests that they may contain unexpected toxins and may provide unreliable nicotine delivery. Many countries have already banned or strictly regulated e-cigarettes. Currently in the United States, e-cigarettes are exempt from regulation as drug-delivery devices. Meanwhile, the presence of e-cigarettes on the Internet, including in Web searches, virtual user communities, and online stores where people sell e-cigarettes on commission, is increasing rapidly. Physicians should be aware of the popularity, questionable efficacy claims, and safety concerns of e-cigarettes so that they may counsel patients against use and advocate for research to inform an evidence-based regulatory approach.

Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil

DOEpatents

Looney, Brian B.; Denham, Miles E.; Jackson, Dennis G.

2014-07-08

The process of treating elemental mercury within the soil is provided by introducing into the soil a heated vapor phase of elemental sulfur. As the vapor phase of elemental sulfur cools, sulfur is precipitated within the soil and then reacts with any elemental mercury thereby producing a reaction product that is less hazardous than elemental mercury.

Vapor Phase Catalytic Ammonia Reduction

NASA Technical Reports Server (NTRS)

Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

1994-01-01

This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

A Simple and Rapid Method for Standard Preparation of Gas Phase Extract of Cigarette Smoke

PubMed Central

Higashi, Tsunehito; Mai, Yosuke; Noya, Yoichi; Horinouchi, Takahiro; Terada, Koji; Hoshi, Akimasa; Nepal, Prabha; Harada, Takuya; Horiguchi, Mika; Hatate, Chizuru; Kuge, Yuji; Miwa, Soichi

2014-01-01

Cigarette smoke consists of tar and gas phase: the latter is toxicologically important because it can pass through lung alveolar epithelium to enter the circulation. Here we attempt to establish a standard method for preparation of gas phase extract of cigarette smoke (CSE). CSE was prepared by continuously sucking cigarette smoke through a Cambridge filter to remove tar, followed by bubbling it into phosphate-buffered saline (PBS). An increase in dry weight of the filter was defined as tar weight. Characteristically, concentrations of CSEs were represented as virtual tar concentrations, assuming that tar on the filter was dissolved in PBS. CSEs prepared from smaller numbers of cigarettes (original tar concentrations ≤15 mg/ml) showed similar concentration-response curves for cytotoxicity versus virtual tar concentrations, but with CSEs from larger numbers (tar ≥20 mg/ml), the curves were shifted rightward. Accordingly, the cytotoxic activity was detected in PBS of the second reservoir downstream of the first one with larger numbers of cigarettes. CSEs prepared from various cigarette brands showed comparable concentration-response curves for cytotoxicity. Two types of CSEs prepared by continuous and puff smoking protocols were similar regarding concentration-response curves for cytotoxicity, pharmacology of their cytotoxicity, and concentrations of cytotoxic compounds. These data show that concentrations of CSEs expressed by virtual tar concentrations can be a reference value to normalize their cytotoxicity, irrespective of numbers of combusted cigarettes, cigarette brands and smoking protocols, if original tar concentrations are ≤15 mg/ml. PMID:25229830

Vapor Store Owner Beliefs and Messages to Customers.

PubMed

Cheney, Marshall K; Gowin, Mary; Wann, Taylor Franklin

2016-05-01

Electronic cigarette (e-cigarette) use is becoming increasingly popular but little is known about the role of the local vapor store in promoting use and influencing customer attitudes and beliefs about vaping. Thirty-three vapor store owners were interviewed about their personal beliefs and attitudes about e-cigarettes and what they told customers about the health impact of using e-cigarettes. Interviews were recorded then transcribed, coded, and analyzed for themes. Vapor store owners used the internet to obtain information about vaping, most often from YouTube and industry sources. Owners often did not have the training to critically evaluate research studies posted on the internet. Owners promoted vaping as a healthier alternative to smoking and often compared it to a medical treatment. Owners considered ingredients in the e-liquid as safe to use if it was safe to eat and discussed other foods vapor ingredients were found in. Owners also discussed the safety of secondhand vapor. Owners described the health impact of nicotine in e-liquid by comparing nicotine to caffeine and promoted the nicotine in e-liquid as coming from vegetables rather than tobacco. Finally, owners talked about vaping as a habit rather than a continued addiction to nicotine. Local store owners are an important source of health information for current and potential e-cigarette users but their messages to customers may be based on incomplete or misinterpreted information. Understanding local store owner messages to customers in addition to internet-based messages is an important area for future public health research. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sporicidal Activity of the KMT reagent in its vapor phase against Geobacillus stearothermophilus Spores.

PubMed

Kida, Nori; Mochizuki, Yasushi; Taguchi, Fumiaki

2007-01-01

In an investigation of the sporicidal activity of the KMT reagent, a vapor phase study was performed using five kinds of carriers contaminated with Geobacillus stearothermophilus spores. When 25 ml of the KMT reagent was vaporized in a chamber (capacity; approximately 95 liters), the 2-step heating method (vaporization by a combination of low temperature and high temperature) showed the most effective sporicidal activity in comparison with the 1-step heating method (rapid vaporization). The 2-step heating method appeared to be related to the sporicidal activity of vaporized KMT reagent, i.e., ethanol and iodine, which vaporized mainly when heated at a low temperature such as 55 C, and acidic water, which vaporized mainly when heated at a high temperature such as 300 C. We proposed that the KMT reagent can be used as a new disinfectant not only in the liquid phase but also in the vapor phase in the same way as peracetic acid and hydrogen peroxide.

Comparison of environmental tobacco smoke (ETS) concentrations generated by an electrically heated cigarette smoking system and a conventional cigarette.

PubMed

Tricker, Anthony R; Schorp, Matthias K; Urban, Hans-Jörg; Leyden, Donald; Hagedorn, Heinz-Werner; Engl, Johannes; Urban, Michael; Riedel, Kirsten; Gilch, Gerhard; Janket, Dinamis; Scherer, Gerhard

2009-01-01

Smoking conventional lit-end cigarettes results in exposure of nonsmokers to potentially harmful cigarette smoke constituents present in environmental tobacco smoke (ETS) generated by sidestream smoke emissions and exhaled mainstream smoke. ETS constituent concentrations generated by a conventional lit-end cigarette and a newly developed electrically heated cigarette smoking system (EHCSS) that produces only mainstream smoke and no sidestream smoke emissions were investigated in simulated "office" and "hospitality" environments with different levels of baseline indoor air quality. Smoking the EHCSS (International Organisation for Standardization yields: 5 mg tar, 0.3 mg nicotine, and 0.6 mg carbon monoxide) in simulated indoor environments resulted in significant reductions in ETS constituent concentrations compared to when smoking a representative lit-end cigarette (Marlboro: 6 mg tar, 0.5 mg nicotine, and 7 mg carbon monoxide). In direct comparisons, 24 of 29 measured smoke constituents (83%) showed mean reductions of greater than 90%, and 5 smoke constituents (17%) showed mean reductions between 80% and 90%. Gas-vapor phase ETS markers (nicotine and 3-ethenylpyridine) were reduced by an average of 97% (range 94-99%). Total respirable suspended particles, determined by online particle measurements and as gravimetric respirable suspended particles, were reduced by 90% (range 82-100%). The mean and standard deviation of the reduction of all constituents was 94 +/- 4%, indicating that smoking the new EHCSS in simulated "office" and "hospitality" indoor environments resulted in substantial reductions of ETS constituents in indoor air.

Investigation of local evaporation flux and vapor-phase pressure at an evaporative droplet interface.

PubMed

Duan, Fei; Ward, C A

2009-07-07

In the steady-state experiments of water droplet evaporation, when the throat was heating at a stainless steel conical funnel, the interfacial liquid temperature was found to increase parabolically from the center line to the rim of the funnel with the global vapor-phase pressure at around 600 Pa. The energy conservation analysis at the interface indicates that the energy required for evaporation is maintained by thermal conduction to the interface from the liquid and vapor phases, thermocapillary convection at interface, and the viscous dissipation globally and locally. The local evaporation flux increases from the center line to the periphery as a result of multiple effects of energy transport at the interface. The local vapor-phase pressure predicted from statistical rate theory (SRT) is also found to increase monotonically toward the interface edge from the center line. However, the average value of the local vapor-phase pressures is in agreement with the measured global vapor-phase pressure within the measured error bar.

Adolescents' understanding and use of nicotine in e-cigarettes.

PubMed

Pepper, Jessica K; Farrelly, Matthew C; Watson, Kimberly A

2018-07-01

Nicotine harms adolescent brain development and contributes to addiction. Some adolescents report using nicotine-free e-cigarettes, but the accuracy of their reporting is unclear. We explored adolescents' use of nicotine-free e-cigarettes and understanding of chemicals in e-cigarettes, including nicotine. Using social media, we recruited 1589 US adolescents (aged 15-17) who reported past 30-day use of e-cigarettes in 2016. We assessed perceptions of the nicotine source in e-liquid and whether e-cigarette aerosol is just "water vapor." We explored differences among adolescents who usually used e-cigarettes with nicotine (n = 473) and without nicotine (n = 452). We used weights to calibrate our sample to the Youth Risk Behavior Survey. Twenty-nine percent usually used e-cigarettes without nicotine, 28% with nicotine, 39% with "both," and 5% were "not sure." Few participants (17% of non-nicotine users vs. 34% of nicotine users, p < .001) understood the nicotine was derived from tobacco. Youth who thought e-cigarette aerosol was just water vapor were more likely to usually use without nicotine. Older adolescents and current tobacco users were less likely to usually use without nicotine. The adolescents who reported usually using e-cigarettes without nicotine had poorer knowledge of e-cigarettes. This lack of understanding could contribute to inaccurate reporting of nicotine use. Most youth thought the nicotine in e-cigarettes was artificial, potentially indicating a belief that this nicotine is "safer." The US Food & Drug Administration will require nicotine warnings on e-cigarettes in 2018; a complementary educational campaign could address youths' misperceptions about nicotine and other chemicals in e-cigarette aerosol. Copyright © 2018 Elsevier Ltd. All rights reserved.

Speciation and quantification of vapor phases in soy biodiesel and waste cooking oil biodiesel.

PubMed

Peng, Chiung-Yu; Lan, Cheng-Hang; Dai, Yu-Tung

2006-12-01

This study characterizes the compositions of two biodiesel vapors, soy biodiesel and waste cooking oil biodiesel, to provide a comprehensive understanding of biodiesels. Vapor phases were sampled by purging oil vapors through thermal desorption tubes which were then analyzed by the thermal desorption/GC/MS system. The results show that the compounds of biodiesel vapors can be divided into four groups. They include methyl esters (the main biodiesel components), oxygenated chemicals, alkanes and alkenes, and aromatics. The first two chemical groups are only found in biodiesel vapors, not in the diesel vapor emissions. The percentages of mean concentrations for methyl esters, oxygenated chemicals, alkanes and alkenes, and aromatics are 66.1%, 22.8%, 4.8% and 6.4%, respectively for soy biodiesel, and 35.8%, 35.9%, 27.9% and 0.3%, respectively for waste cooking oil biodiesel at a temperature of 25+/-2 degrees C. These results show that biodiesels have fewer chemicals and lower concentrations in vapor phase than petroleum diesel, and the total emission rates are between one-sixteenth and one-sixth of that of diesel emission, corresponding to fuel evaporative emissions of loading losses of between 106 microg l(-1) and 283 microg l(-1). Although diesels generate more vapor phase emissions, biodiesels still generate considerable amount of vapor emissions, particularly the emissions from methyl esters and oxygenated chemicals. These two chemical groups are more reactive than alkanes and aromatics. Therefore, speciation and quantification of biodiesel vapor phases are important.

Vapor-liquid phase separator permeability results

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Frederking, T. H. K.

1981-01-01

Continued studies are described in the area of vapor-liquid phase separator work with emphasis on permeabilities of porous sintered plugs (stainless steel, nominal pore size 2 micrometer). The temperature dependence of the permeability has been evaluated in classical fluid using He-4 gas at atmospheric pressure and in He-2 on the basis of a modified, thermosmotic permeability of the normal fluid.

Development of Vapor-Phase Catalytic Ammonia Removal System

NASA Technical Reports Server (NTRS)

Flynn, Michael; Fisher, John; Kiss, Mark; Borchers, Bruce; Tleimat, Badawi; Tleimat, Maher; Quinn, Gregory; Fort, James; Nalette, Tim; Baker, Gale;

Thermal injury patterns associated with electronic cigarettes.

PubMed

Jiwani, Alisha Z; Williams, James F; Rizzo, Julie A; Chung, Kevin K; King, Booker T; Cancio, Leopoldo C

2017-01-01

E-cigarettes are typically lithium-ion battery-operated devices that simulate smoking by heating a nicotine-solution into a vapor that the user inhales. E-cigarette use is becoming rapidly popular as an alternative to traditional cigarette smoking. This report describes an emerging problem associated with e-cigarettes, consisting of 10 thermally injured patients seen at a single burn center over a 2-year period from 2014 to 2016. Our cohort was comprised mainly of young adults who sustained mixed partial and full thickness burns as a result of e-cigarette-related explosions. In many documented scenarios, a malfunctioning or over-heated battery is the cause. Our data support the need for increased awareness among healthcare providers and the general public of the potential harms of e-cigarette use, modification, storage, and charging.

An Indirect Method for Vapor Pressure and Phase Change Enthalpy Determination by Thermogravimetry

NASA Astrophysics Data System (ADS)

Giani, Samuele; Riesen, Rudolf; Schawe, Jürgen E. K.

2018-07-01

Vapor pressure is a fundamental property of a pure substance. This property is the pressure of a compound's vapor in thermodynamic equilibrium with its condensed phase (solid or liquid). When phase equilibrium condition is met, phase coexistence of a pure substance involves a continuum interplay of vaporization or sublimation to gas and condensation back to their liquid or solid form, respectively. Thermogravimetric analysis (TGA) techniques are based on mass loss determination and are well suited for the study of such phenomena. In this work, it is shown that TGA method using a reference substance is a suitable technique for vapor pressure determination. This method is easy and fast because it involves a series of isothermal segments. In contrast to original Knudsen's approach, where the use of high vacuum is mandatory, adopting the proposed method a given experimental setup is calibrated under ambient pressure conditions. The theoretical framework of this method is based on a generalization of Langmuir equation of free evaporation: The real strength of the proposed method is the ability to determine the vapor pressure independently of the molecular mass of the vapor. A demonstration of this method has been performed using the Clausius-Clapeyron equation of state to derive the working equation. This algorithm, however, is adaptive and admits the use of other equations of state. The results of a series of experiments with organic molecules indicate that the average difference of the measured and the literature vapor pressure amounts to about 5 %. Vapor pressure determined in this study spans from few mPa up to several kPa. Once the p versus T diagram is obtained, phase transition enthalpy can additionally be calculated from the data.

FIELD TRAPPING OF SUBSURFACE VAPOR PHASE PETROLEUM HYDROCARBONS

EPA Science Inventory

Soil gas samples from intact soil cores were collected on adsorbents at a field site, then thermally desorbed and analyzed by laboratory gas chromatography (GC). ertical concentration profiles of predominant vapor phase petroleum hydrocarbons under ambient conditions were obtaine...

Perceived Harm of Secondhand Electronic Cigarette Vapors and Policy Support to Restrict Public Vaping: Results From a National Survey of US Adults

PubMed Central

Bigman, Cabral A.; Sanders-Jackson, Ashley; Tan, Andy S. L.

2016-01-01

Abstract Introduction: There is ongoing debate over banning electronic cigarette (e-cigarette) use (vaping) in public places. Many people perceive secondhand e-cigarette vapors (SHV) to be relatively harmless, which may affect their support for policies to restrict vaping in public places. Given that awareness of secondhand cigarette smoke risks predicts public support for clean air policies, we hypothesized that greater perceived harm of SHV to personal health would be associated with stronger support for vaping restrictions. Methods: Data from 1449 US adults in a national online panel was collected from October to December 2013. Using multiple regressions, we predict a three-item scale of support for e-cigarette restricting policies in restaurants, bars/casinos/clubs, and parks using a two-item scale measuring concern and perceptions of harm to personal health from breathing SHV. Analyses adjusted for demographic covariates, smoking status and e-cigarette use, and were weighted to represent the US adult population. Results: Overall, respondents considered SHV exposure to be moderately harmful to their health and tended to favor restricting vaping in public places. Perceived harm of SHV to personal health was associated with support for vaping restrictions in public spaces (unstandardized regression coefficient, B = 0.18, 95% CI = 0.16, 0.20). Current smokers (vs. nonsmokers), those who ever tried e-cigarettes (vs. never), those who directly observed others vaping, and those with some college education (vs. high school or less) demonstrated less support for such policies. Implications: This study shows that support for banning vaping in public spaces in the United States is positively associated with perceived health harms of SHV exposure. The findings suggest that continued monitoring of public perception of SHV harm and the accuracy of e-cigarette marketing claims about reduced harm would be needed to guide clean air policy decisions. With the emergence of new

Smoke composition and predicting relationships for international commercial cigarettes smoked with three machine-smoking conditions.

PubMed

Counts, M E; Morton, M J; Laffoon, S W; Cox, R H; Lipowicz, P J

2005-04-01

The study objectives were to determine the effects of smoking machine puffing parameters on mainstream smoke composition and to express those effects as predicting relationships. Forty-eight commercial Philip Morris USA and Philip Morris International cigarettes from international markets and the 1R4F reference cigarette were machine-smoked using smoking conditions defined by the International Organization of Standardization (ISO), the Massachusetts Department of Public Health (MDPH), and Health Canada (HC). Cigarette tobacco fillers were analyzed for nitrate, nicotine, tobacco-specific nitrosamines (TSNA), and ammonia. Mainstream yields for tar and 44 individual smoke constituents and "smoke pH" were determined. Cigarette constituent yields typically increased in the order ISOcigarettes with higher initial filter ventilation and were also generally greater for vapor-phase constituents than for particulate-phase constituents. Predicting relationships were developed between ISO tar and ISO, MDPH, and HC constituent yields and between MDPH tar and HC tar and respective smoking condition yields. MDPH and HC constituent yields could be predicted with similar reliability using ISO tar or the corresponding smoking-condition tar. The reliability of the relationships varied from strong to weak, depending on particular constituents. Weak predicting relationships for nitrogen oxides and TSNA's, for example, were improved with inclusion of tobacco filler composition factors. "Smoke pH" was similar for all cigarettes at any one smoking condition, and overall marginally lower at HC conditions than at ISO or MDPH conditions.

Vapor-Phase Stoichiometry and Heat Treatment of CdTe Starting Material for Physical Vapor Transport

NASA Technical Reports Server (NTRS)

Su, Ching-Hua; Sha, Yi-Gao; Lehoczky, S. L.; Liu, Hao-Chieh; Fang, Rei; Brebrick, R. F.

1998-01-01

Six batches of CdTe, having total amounts of material from 99 to 203 g and gross mole fraction of Te, X(sub Te), 0.499954-0.500138, were synthesized from pure Cd and Te elements. The vapor-phase stoichiometry of the assynthesized CdTe batches was determined from the partial pressure of Te2, P(sub Te2) using an optical absorption technique. The measured vapor compositions at 870 C were Te-rich for all of the batches with partial pressure ratios of Cd to Te2, P(sub Cd)/P(sub Te2), ranging from 0.00742 to 1.92. After the heat treatment of baking under dynamic vacuum at 870 C for 8 min, the vapor-phase compositions moved toward that of the congruent sublimation, i.e. P(sub Cd)/P(sub Te2) = 2.0, with the measured P(sub Cd)/P(sub Te2) varying from 1.84 to 3.47. The partial pressure measurements on one of the heat-treated samples also showed that the sample remained close to the congruent sublimation condition over the temperature range 800-880 C.

The effect of menthol vapor on nasal sensitivity to chemical irritation.

PubMed

Wise, Paul M; Preti, George; Eades, Jason; Wysocki, Charles J

2011-10-01

Among other effects, menthol added to cigarettes may modulate sensory response to cigarette smoke either by masking "harshness" or contributing to a desirable "impact." However, harshness and impact have been imprecisely defined and assessed using subjective measures. Thus, the current experiments used an objective measure of sensitivity to chemical irritation in the nose to test the hypothesis that menthol vapor modulates sensitivity to chemical irritation in the airways. Nasal irritation thresholds were measured for 2 model compounds (acetic acid and allyl isothiocyanate) using nasal lateralization. In this technique, participants simultaneously sniff clean air in one nostril and chemical vapor in the other and attempt to identify the stimulated nostril. People cannot lateralize based on smell alone but can do so when chemicals are strong enough to feel. In one condition, participants were pretreated by sniffing menthol vapor. In a control condition, participants were pretreated by sniffing an odorless blank (within-subjects design). Pretreatment with menthol vapor decreased sensitivity to nasal irritation from acetic acid (participants required higher concentrations to lateralize) but increased sensitivity to allyl isothiocyanate (lower concentrations were required). The current experiments provide objective evidence that menthol vapor can modulate sensitivity to chemical irritation in the upper airways in humans. Cigarette smoke is a complex mixture of chemicals and particulates, and further work will be needed to determine exactly how menthol modulates smoking sensation. A better understanding could lead to treatments tailored to help menthol smokers quit by replacing the sensation of mentholated cigarettes.

[Summary of the existing knowledge about electronic cigarettes].

PubMed

Cselkó, Zsuzsa; Pénzes, Melinda

2016-06-19

The decreasing proportion of smokers due to smoking restrictions have led producers to invent and disseminate electronic cigarettes (e-cigarettes) worldwide as a new form of nicotine enjoyment. This review summarizes the existing knowledge about e-cigarettes based on publications of PubMed, and on reviews and research data published by national and international scientific institutions. Present knowledge about the composition of e-cigarettes confirms that they are harmful products since their vapor is equally detrimental to the health of users and bystanders. Their benefits in smoking cessation still have not been justified by adequate scientific evidence, however, it has been proven that e-cigarettes uphold nicotine addiction and may increase the risk of starting conventional cigarette use by youth. In order to ensure the results of tobacco control policy and to assist smoking cessation, the same regulations are to be applied to e-cigarettes as to conventional tobacco products.

Phase-field model of vapor-liquid-solid nanowire growth

NASA Astrophysics Data System (ADS)

Wang, Nan; Upmanyu, Moneesh; Karma, Alain

2018-03-01

We present a multiphase-field model to describe quantitatively nanowire growth by the vapor-liquid-solid (VLS) process. The free-energy functional of this model depends on three nonconserved order parameters that distinguish the vapor, liquid, and solid phases and describe the energetic properties of various interfaces, including arbitrary forms of anisotropic γ plots for the solid-vapor and solid-liquid interfaces. The evolution equations for those order parameters describe basic kinetic processes including the rapid (quasi-instantaneous) equilibration of the liquid catalyst to a droplet shape with constant mean curvature, the slow incorporation of growth atoms at the droplet surface, and crystallization within the droplet. The standard constraint that the sum of the phase fields equals unity and the conservation of the number of catalyst atoms, which relates the catalyst volume to the concentration of growth atoms inside the droplet, are handled via separate Lagrange multipliers. An analysis of the model is presented that rigorously maps the phase-field equations to a desired set of sharp-interface equations for the evolution of the phase boundaries under the constraint of force balance at three-phase junctions (triple points) given by the Young-Herring relation that includes torque term related to the anisotropy of the solid-liquid and solid-vapor interface excess free energies. Numerical examples of growth in two dimensions are presented for the simplest case of vanishing crystalline anisotropy and the more realistic case of a solid-liquid γ plot with cusped minima corresponding to two sets of (10 ) and (11 ) facets. The simulations reproduce many of the salient features of nanowire growth observed experimentally, including growth normal to the substrate with tapering of the side walls, transitions between different growth orientations, and crawling growth along the substrate. They also reproduce different observed relationships between the nanowire growth

Electronic Cigarette Use by College Students

PubMed Central

Sutfin, Erin L.; McCoy, Thomas P.; Morrell, Holly E. R.; Hoeppner, Bettina B.; Wolfson, Mark

2013-01-01

Background Electronic cigarettes, or ecigarettes, are battery operated devices that deliver nicotine via inhaled vapor. There is considerable controversy about the disease risk and toxicity of ecigarettes and empirical evidence on short- and long-term health effects is minimal. Limited data on e-cigarette use and correlates exist, and to our knowledge, no prevalence rates among U.S. college students have been reported. This study aimed to estimate the prevalence of ecigarette use and identify correlates of use among a large, multi-institution, random sample of college students. Methods 4,444 students from 8 colleges in North Carolina completed a Webbased survey in fall 2009. Results Ever use of ecigarettes was reported by 4.9% of students, with 1.5% reporting past month use. Correlates of ever use included male gender, Hispanic or “Other race” (compared to non-Hispanic Whites), Greek affiliation, conventional cigarette smoking and e-cigarette harm perceptions. Although e-cigarette use was more common among conventional cigarette smokers, 12% of ever e-cigarette users had never smoked a conventional cigarette. Among current cigarette smokers, e-cigarette use was negatively associated with lack of knowledge about e-cigarette harm, but was not associated with intentions to quit. Conclusions Although e-cigarette use was more common among conventional cigarette smokers, it was not exclusive to them. E-cigarette use was not associated with intentions to quit smoking among a sub-sample of conventional cigarette smokers. Unlike older, more established cigarette smokers, e-cigarette use by college students does not appear to be motivated by the desire to quit cigarette smoking. PMID:23746429

A Preliminary Study on the Vapor/Mist Phase Lubrication of a Spur Gearbox

NASA Technical Reports Server (NTRS)

Morales, Wilfredo; Handschuh, Robert F.

1999-01-01

Organophosphates have been the primary compounds used in vapor/mist phase lubrication studies involving ferrous bearing material. Experimental results have indicated that the initial formation of an iron phosphate film on a rubbing ferrous surface, followed by the growth (by cationic diffusion) of a lubricious pyrophosphate-type coating over the iron phosphate, is the reason organophosphates work well as vapor/mist phase lubricants. Recent work, however, has shown that this mechanism leads to the depletion of surface iron atoms and to eventual lubrication failure. A new organophosphate formulation was developed which circumvents surface iron depletion. This formulation was tested by generating an iron phosphate coating on an aluminum surface. The new formulation was then used to vapor/mist phase lubricate a spur gearbox in a preliminary study.

The mouse lymphoma thymidine kinase assay for the assessment and comparison of the mutagenic activity of cigarette mainstream smoke particulate phase.

PubMed

Schramke, H; Meisgen, T J; Tewes, F J; Gomm, W; Roemer, E

2006-10-29

The mouse lymphoma thymidine kinase assay (MLA) has been optimized to quantitatively determine the in vitro mutagenicity of cigarette mainstream smoke particulate phase. To test whether the MLA is able to discriminate between different cigarette types, specially constructed cigarettes each containing a single tobacco type - Bright, Burley, or Oriental - were investigated. The mutagenic activity of the Burley cigarette was statistically significantly lower, up to approximately 40%, than that of the Bright and Oriental cigarettes. To determine the impact of two different sets of smoking conditions, American-blend cigarettes were smoked under US Federal Trade Commission/International Organisation for Standardisation conditions and under Massachusetts Department of Public Health (MDPH) conditions. Conventional cigarettes - eight from the US commercial market plus the Reference Cigarettes 1R4F and 2R4F - and an electrically heated cigarette smoking system (EHCSS) prototype were tested. There were no statistically significant differences between the two sets of smoking conditions on a per mg total particulate matter basis, although there was a consistent trend towards slightly lower mutagenic activity under MDPH conditions. The mutagenic activity of the EHCSS prototype was distinctly lower than that of the conventional cigarettes under both sets of smoking conditions. These results show that the MLA can be used to assess and compare the mutagenic activity of cigarette mainstream smoke particulate phase in the comprehensive toxicological assessment of cigarette smoke.

Phase-transitional Fe3O4/perfluorohexane Microspheres for Magnetic Droplet Vaporization.

PubMed

Wang, Ronghui; Zhou, Yang; Zhang, Ping; Chen, Yu; Gao, Wei; Xu, Jinshun; Chen, Hangrong; Cai, Xiaojun; Zhang, Kun; Li, Pan; Wang, Zhigang; Hu, Bing; Ying, Tao; Zheng, Yuanyi

2017-01-01

Activating droplets vaporization has become an attractive strategy for ultrasound imaging and physical therapy due to the significant increase in ultrasound backscatter signals and its ability to physically damage the tumor cells. However, the current two types of transitional droplets named after their activation methods have their respective limitations. To circumvent the limitations of these activation methods, here we report the concept of magnetic droplet vaporization (MDV) for stimuli-responsive cancer theranostics by a magnetic-responsive phase-transitional agent. This magnetic-sensitive phase-transitional agent-perfluorohexane (PFH)-loaded porous magnetic microspheres (PFH-PMMs), with high magnetic-thermal energy-transfer capability, could quickly respond to external alternating current (AC) magnetic fields to produce thermal energy and trigger the vaporization of the liquid PFH. We systematically demonstrated MDV both in vitro and in vivo. This novel trigger method with deep penetration can penetrate the air-filled viscera and trigger the vaporization of the phase-transitional agent without the need of pre-focusing lesion. This unique MDV strategy is expected to substantially broaden the biomedical applications of nanotechnology and promote the clinical treatment of tumors that are not responsive to chemical therapies.

Hybrid vapor phase-solution phase growth techniques for improved CZT(S,Se) photovoltaic device performance

DOEpatents

Chang, Liang-Yi; Gershon, Talia S.; Haight, Richard A.; Lee, Yun Seog

2016-12-27

A hybrid vapor phase-solution phase CZT(S,Se) growth technique is provided. In one aspect, a method of forming a kesterite absorber material on a substrate includes the steps of: depositing a layer of a first kesterite material on the substrate using a vapor phase deposition process, wherein the first kesterite material includes Cu, Zn, Sn, and at least one of S and Se; annealing the first kesterite material to crystallize the first kesterite material; and depositing a layer of a second kesterite material on a side of the first kesterite material opposite the substrate using a solution phase deposition process, wherein the second kesterite material includes Cu, Zn, Sn, and at least one of S and Se, wherein the first kesterite material and the second kesterite material form a multi-layer stack of the absorber material on the substrate. A photovoltaic device and method of formation thereof are also provided.

Perceived Harm of Secondhand Electronic Cigarette Vapors and Policy Support to Restrict Public Vaping: Results From a National Survey of US Adults.

PubMed

Mello, Susan; Bigman, Cabral A; Sanders-Jackson, Ashley; Tan, Andy S L

2016-05-01

There is ongoing debate over banning electronic cigarette (e-cigarette) use (vaping) in public places. Many people perceive secondhand e-cigarette vapors (SHV) to be relatively harmless, which may affect their support for policies to restrict vaping in public places. Given that awareness of secondhand cigarette smoke risks predicts public support for clean air policies, we hypothesized that greater perceived harm of SHV to personal health would be associated with stronger support for vaping restrictions. Data from 1449 US adults in a national online panel was collected from October to December 2013. Using multiple regressions, we predict a three-item scale of support for e-cigarette restricting policies in restaurants, bars/casinos/clubs, and parks using a two-item scale measuring concern and perceptions of harm to personal health from breathing SHV. Analyses adjusted for demographic covariates, smoking status and e-cigarette use, and were weighted to represent the US adult population. Overall, respondents considered SHV exposure to be moderately harmful to their health and tended to favor restricting vaping in public places. Perceived harm of SHV to personal health was associated with support for vaping restrictions in public spaces (unstandardized regression coefficient, B = 0.18, 95% CI = 0.16, 0.20). Current smokers (vs. nonsmokers), those who ever tried e-cigarettes (vs. never), those who directly observed others vaping, and those with some college education (vs. high school or less) demonstrated less support for such policies. This study shows that support for banning vaping in public spaces in the United States is positively associated with perceived health harms of SHV exposure. The findings suggest that continued monitoring of public perception of SHV harm and the accuracy of e-cigarette marketing claims about reduced harm would be needed to guide clean air policy decisions. With the emergence of new scientific evidence of the potential effects of SHV

An Examination of Electronic Cigarette Content on Social Media: Analysis of E-Cigarette Flavor Content on Reddit.

PubMed

Wang, Lei; Zhan, Yongcheng; Li, Qiudan; Zeng, Daniel D; Leischow, Scott J; Okamoto, Janet

2015-11-20

In recent years, the emerging electronic cigarette (e-cigarette) marketplace has shown great development prospects all over the world. Reddit, one of the most popular forums in the world, has a very large user group and thus great influence. This study aims to gain a systematic understanding of e-cigarette flavors based on data collected from Reddit. Flavor popularity, mixing, characteristics, trends, and brands are analyzed. Fruit flavors were mentioned the most (n = 15,720) among all the posts and were among the most popular flavors (n = 2902) used in mixed blends. Strawberry and vanilla flavors were the most popular for e-juice mixing. The number of posts discussing e-cigarette flavors has increased sharply since 2014. Mt. Baker Vapor and Hangen were the most popular brands discussed among users. Information posted on Reddit about e-cigarette flavors reflected consumers' interest in a variety of flavors. Our findings suggest that Reddit could be used for data mining and analysis of e-cigarette-related content. Understanding how e-cigarette consumers' view and utilize flavors within their vaping experience and how producers and marketers use social media to promote flavors and sell products could provide valuable information for regulatory decision-makers.

Electrothermal Vaporization-QQQ-ICP-MS for Determination of Chromium in Mainstream Cigarette Smoke Particulate

PubMed Central

Fresquez, Mark R.; Gonzalez-Jimenez, Nathalie; Gray, Naudia; Valentin-Blasini, Liza; Watson, Clifford H.; Pappas, R. Steven

2017-01-01

Chromium is transported in mainstream tobacco smoke at very low concentrations. However, when chromium is deposited too deeply in the lungs for mucociliary clearance, or is in a particle that is too large to pass directly through tissues, it bioaccumulates in the lungs of smokers. It is important to determine the concentrations of chromium that are transported in mainstream smoke. Several reliable studies have resulted in reports of chromium concentrations in smoke particulate that were below limits of detection for the instruments and methods employed. In this study, electrothermal vaporization-triple quad-inductively coupled plasma-mass spectrometry (ETV-QQQ-ICP-MS) was chosen for determination of chromium concentrations in mainstream smoke because of the high sensitivity of ETV combined with QQQ-ICP-MS. The smoke from five reference, quality control, and commercial cigarettes was analyzed using ETV-QQQ-ICP-MS with isotope dilution for quantitative determination of chromium. The method limit of detection (LOD) was sufficiently low that chromium concentrations in mainstream smoke could indeed be determined. The chromium concentrations in the smoke particulate were between 0.60 and 1.03 ng/cigarette. The range of chromium concentrations was at or below previously reported LODs. Determination of the oxidation state of the chromium transported in mainstream smoke would also be important, in consideration of the fact that both chromium(III) and chromium(VI) oxidation states cause inhalation toxicity, but chromium(VI) is also a carcinogen. It was possible to separate the oxidation states using ETV-QQQ-ICP-MS. However, determination of individual species at the levels found in mainstream smoke particulate matter was not possible with the present method. PMID:28164228

A comprehensive evaluation of the toxicology of cigarette ingredients: aliphatic carbonyl compounds.

PubMed

Coggins, Christopher R E; Jerome, Ann M; Edmiston, Jeffery S; Oldham, Michael J

2011-06-01

Aliphatic carbonyl compounds are used as ingredients in cigarette tobacco or cigarette filters. A battery of tests was used to compare toxicity of mainstream smoke from experimental cigarettes containing 15 aliphatic carbonyl compounds that were added individually to experimental cigarettes at three different levels. Smoke from experimental and control cigarettes were evaluated using analytical chemistry, in vitro cytotoxicity (neutral red uptake), and mutagenicity (five bacterial strains) studies. For one compound, glycerol triacetate (GTA), two 90-day inhalation studies were also performed, using different inclusion levels into either tobacco or cigarette filter. Several smoke constituent concentrations were reduced with the highest inclusion level of GTA in tobacco; incorporation of GTA into the filter, and the other compounds into tobacco, produced effectively no changes. Cytotoxicity was reduced by the highest inclusion of GTA into tobacco for both gas-vapor and particulate phases of smoke; incorporation of GTA into the filter, and the other compounds into tobacco, showed no changes. Mutagenicity was reduced by the middle and high inclusion levels of GTA into tobacco (TA1537 strain with S9); incorporation of GTA into the filter, and the other compounds into tobacco, showed no changes. Inclusion of GTA in tobacco at 100,000 ppm reduced the biological effects of the smoke in the various test systems reported in this study, although inclusion into the filter did not appear to have any major effect on the endpoints studied. The other 14 aliphatic carbonyl compounds that were tested lacked a toxicological response.

Effectiveness of cigarette filter tips for reducing cadmium in relation to other mainstream smoke constituents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bache, C.A.; Lisk, D.J.; Shane, B.S.

The effectiveness of filter tips for reducing cadmium, tar, nicotine, carbon monoxide and carbon dioxide in cigarettes was studied. The cigarettes were made from tobacco grown on municipal sewage sludge-amended soil and were therefore high in cadmium. When machine-smoked, filter tips did not result in a significant reduction of cadmium deposited on Cambridge filters. This may indicate that a considerable fraction of cadmium is present in the vapor phase of the smoke and therefore not reduced to the same extent as the tar by certain filters. Nicotine and carbon monoxide were reduced to a lesser extent than tar. This indicatesmore » that the filter tip has influenced the combustion of the tobacco column during smoking.« less

Continuous Determination of High-Vapor Phase Concentrations of Tetrachloroethylene Using On-Line Mass Spectrometry

EPA Science Inventory

A method was developed to determine the vapor concentration of tetrachloroethylene (PCE) at and below its equilibrium vapor phase concentration, 168,000 μg/L (25°C). Vapor samples were drawn by vacuum into a six-port sampling valve and injected through a jet separator into an io...

The Use of Substances Other Than Nicotine in Electronic Cigarettes Among College Students.

PubMed

Kenne, Deric R; Fischbein, Rebecca L; Tan, Andy Sl; Banks, Mark

2017-01-01

Electronic cigarettes (e-cigarettes) have grown in popularity, especially among youth and young adults. Although e-cigarettes were originally intended to vaporize a liquid mixture containing nicotine, there appears to be an increasing trend in other substance use in e-cigarettes (OSUE). Cross-sectional data from 1542 undergraduate college student e-cigarette users from a large Midwestern university were collected via online survey to assess prevalence of e-cigarette use, reasons for use, perceived harm, and prevalence and predictors of OSUE. Nearly 7% (6.94%) reported using an e-cigarette to vaporize and inhale a substance other than nicotine. Current tobacco cigarette smokers were significantly more likely to report OSUE (51.0%) as compared with never (33.7%) and former (15.4%) smokers. Among respondents reporting OSUE, the primary reason for e-cigarette use was "safer than cigarettes" (21.7%), followed by "experimentation" (18.9%) and "friends use" (17.0%). Most (77.9%) reported using cannabis or some derivative of cannabis in an e-cigarette. Binomial logistic regression found that women were less likely to report OSUE by a factor of 0.60, former tobacco cigarette smokers as compared with never smokers were more likely to report OSUE by a factor of 1.87, and e-cigarette users who reported using e-cigarettes for "cool or trendy" reasons were more likely to report OSUE by a factor of 2.89. Little is known regarding the health effects of cannabis and cannabis derivatives delivered through e-cigarettes. Concern may also be warranted regarding the potential dangers of this young population using substances more dangerous than cannabis in e-cigarettes. Knowledge is limited regarding the public health impact of vaping cannabis or other illicit substances among college student populations. This study stresses the need for continued research regarding the vaping of cannabis and other illicit substances among college students.

Evaluation of whole cigarette smoke induced oxidative stress in A549 and BEAS-2B cells.

PubMed

Zhang, Shimin; Li, Xiang; Xie, Fuwei; Liu, Kejian; Liu, Huimin; Xie, Jianping

2017-09-01

Cigarette smoke is a complex and oxidative aerosol. Previous researches on the hazards of cigarette smoke mainly focused on the adverse bioeffects induced by its condensates or gas vapor phase, which ignored the dynamic processes of smoking and the cigarette smoke aging. To overcome these disadvantages, we performed air-liquid interface exposure of whole smoke, which used native and unmodified smoke and ensured the exposure similar to physiological inhalation. Our results indicated that whole cigarette smoke induced lung epithelial cells (A549) and bronchial epithelial cells (BEAS-2B) damages in cytotoxicity assays (methyl thiazoly tetrazolium and neutral red uptake assays). In addition, A549 and BEAS-2B cells showed oxidative damages in whole smoke exposure, with concentration change of several biomarkers (reduced and oxidized glutathione, malondialdehyde, 4-hydroxyhydroxy-2-nonenal, extracellular superoxide dismutase, and 8-hydroxyl deoxyguanosine). These results indicate that whole smoke-induced oxidative stress occurs in two different kinds of cells at air-liquid interface. Copyright © 2017 Elsevier B.V. All rights reserved.

Oral Trauma and Tooth Avulsion Following Explosion of E-Cigarette.

PubMed

Rogér, James M; Abayon, Maricelle; Elad, Sharon; Kolokythas, Antonia

2016-06-01

Electronic cigarettes (E-cigarettes), or personal vaporizers, were introduced in 2003 and have been available in the United States since 2007. In addition to the health and safety concerns of the aerosol delivery of nicotine through E-cigarettes, during the past 8 years, reports of explosions and fires caused by the E-cigarette devices have led the US Fire Administration to evaluate the safety of these devices. These explosions have been observed frequently enough that the US Department of Transportation has recently banned E-cigarette devices in checked baggage aboard airplanes. This report contributes to existing knowledge about the hazards related to E-cigarettes by describing oral hard and soft tissue injuries from an E-cigarette explosion. Copyright © 2016 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Vapor-crystal phase transition in synthesis of paracetamol films by vacuum evaporation and condensation

NASA Astrophysics Data System (ADS)

Belyaev, A. P.; Rubets, V. P.; Antipov, V. V.; Bordei, N. S.; Zarembo, V. I.

2014-03-01

We report on the structural and technological investigations of the vapor-crystal phase transition during synthesis of paracetamol films of the monoclinic system by vacuum evaporation and condensation in the temperature range 220-320 K. The complex nature of the transformation accompanied by the formation of a gel-like phase is revealed. The results are interpreted using a model according to which the vapor-crystal phase transition is not a simple first-order phase transition, but is a nonlinear superposition of two phase transitions: a first-order transition with a change in density and a second-order phase transition with a change in ordering. Micrographs of the surface of the films are obtained at different phases of formation.

Science and Electronic Cigarettes: Current Data, Future Needs

PubMed Central

Breland, Alison; Spindle, Tory; Weaver, Michael; Eissenberg, Thomas

2014-01-01

Electronic cigarettes (ECIGs), also referred to as electronic nicotine delivery systems (ENDS) or ‘e-cigarettes’, generally consist of a power source (usually a battery) and heating element (commonly referred to as an atomizer) that vaporizes a solution (e-liquid). The user inhales the resulting vapor. ECIGs have been increasing in popularity since they were introduced into the US market in 2007. Many questions remain about these products, and limited research has been conducted. This review will describe the available research on what ECIGs are, effects of use, survey data on awareness and use, and the utility of ECIGs to help smokers quit using tobacco cigarettes. This review will also describe arguments for and against ECIGs, and concludes with steps to move research on ECIGs forward. PMID:25089952

An Examination of Electronic Cigarette Content on Social Media: Analysis of E-Cigarette Flavor Content on Reddit

PubMed Central

Wang, Lei; Zhan, Yongcheng; Li, Qiudan; Zeng, Daniel D.; Leischow, Scott J.; Okamoto, Janet

2015-01-01

In recent years, the emerging electronic cigarette (e-cigarette) marketplace has shown great development prospects all over the world. Reddit, one of the most popular forums in the world, has a very large user group and thus great influence. This study aims to gain a systematic understanding of e-cigarette flavors based on data collected from Reddit. Flavor popularity, mixing, characteristics, trends, and brands are analyzed. Fruit flavors were mentioned the most (n = 15,720) among all the posts and were among the most popular flavors (n = 2902) used in mixed blends. Strawberry and vanilla flavors were the most popular for e-juice mixing. The number of posts discussing e-cigarette flavors has increased sharply since 2014. Mt. Baker Vapor and Hangen were the most popular brands discussed among users. Information posted on Reddit about e-cigarette flavors reflected consumers’ interest in a variety of flavors. Our findings suggest that Reddit could be used for data mining and analysis of e-cigarette-related content. Understanding how e-cigarette consumers’ view and utilize flavors within their vaping experience and how producers and marketers use social media to promote flavors and sell products could provide valuable information for regulatory decision-makers. PMID:26610541

Transient-pressure analysis in geothermal steam reservoirs with an immobile vaporizing liquid phase

USGS Publications Warehouse

Moench, A.F.; Atkinson, P.G.

1978-01-01

A finite-difference model for the radial horizontal flow of steam through a porous medium is used to evaluate transient-pressure behavior in the presence of an immobile vaporizing or condensing liquid phase. Graphs of pressure drawdown and buildup in terms of dimensionless pressure and time are obtained for a well discharging steam at a constant mass flow rate for a specified time. The assumptions are made that the steam is in local thermal equilibrium with the reservoir rocks, that temperature changes are due only to phase change, and that effects of vapor-pressure lowering are negligible. Computations show that when a vaporizing liquid phase is present the pressure drawdown exhibits behavior similar to that observed in noncondensable gas reservoirs, but delayed in time. A theoretical analysis allows for the computation of this delay and demonstrates that it is independent of flow geometry. The response that occurs upon pressure buildup is markedly different from that in a noncondensable gas system. This result may provide a diagnostic tool for establishing the existence of phase-change phenomena within a reservoir. ?? 1979.

Electrothermal Vaporization-QQQ-ICP-MS for Determination of Chromium in Mainstream Cigarette Smoke Particulate.

PubMed

Fresquez, Mark R; Gonzalez-Jimenez, Nathalie; Gray, Naudia; Valentin-Blasini, Liza; Watson, Clifford H; Pappas, R Steven

2017-05-01

Chromium is transported in mainstream tobacco smoke at very low concentrations. However, when chromium is deposited too deeply in the lungs for mucociliary clearance, or is in a particle that is too large to pass directly through tissues, it bioaccumulates in the lungs of smokers. It is important to determine the concentrations of chromium that are transported in mainstream smoke. Several reliable studies have resulted in reports of chromium concentrations in smoke particulate that were below limits of detection (LODs) for the instruments and methods employed. In this study, electrothermal vaporization-triple quad-inductively coupled plasma-mass spectrometry (ETV-QQQ-ICP-MS) was chosen for determination of chromium concentrations in mainstream smoke because of the high sensitivity of ETV combined with QQQ-ICP-MS. The smoke from five reference, quality control, and commercial cigarettes was analyzed using ETV-QQQ-ICP-MS with isotope dilution for quantitative determination of chromium. The method LOD was sufficiently low that chromium concentrations in mainstream smoke could indeed be determined. The chromium concentrations in the smoke particulate were between 0.60 and 1.03 ng/cigarette. The range of chromium concentrations was at or below previously reported LODs. Determination of the oxidation state of the chromium transported in mainstream smoke would also be important, in consideration of the fact that both chromium(III) and chromium(VI) oxidation states cause inhalation toxicity, but chromium(VI) is also a carcinogen. It was possible to separate the oxidation states using ETV-QQQ-ICP-MS. However, determination of individual species at the levels found in mainstream smoke particulate matter was not possible with the present method. Published by Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Improved thermal lattice Boltzmann model for simulation of liquid-vapor phase change

NASA Astrophysics Data System (ADS)

Li, Qing; Zhou, P.; Yan, H. J.

2017-12-01

In this paper, an improved thermal lattice Boltzmann (LB) model is proposed for simulating liquid-vapor phase change, which is aimed at improving an existing thermal LB model for liquid-vapor phase change [S. Gong and P. Cheng, Int. J. Heat Mass Transfer 55, 4923 (2012), 10.1016/j.ijheatmasstransfer.2012.04.037]. First, we emphasize that the replacement of ∇ .(λ ∇ T ) /∇.(λ ∇ T ) ρ cV ρ cV with ∇ .(χ ∇ T ) is an inappropriate treatment for diffuse interface modeling of liquid-vapor phase change. Furthermore, the error terms ∂t 0(T v ) +∇ .(T vv ) , which exist in the macroscopic temperature equation recovered from the previous model, are eliminated in the present model through a way that is consistent with the philosophy of the LB method. Moreover, the discrete effect of the source term is also eliminated in the present model. Numerical simulations are performed for droplet evaporation and bubble nucleation to validate the capability of the model for simulating liquid-vapor phase change. It is shown that the numerical results of the improved model agree well with those of a finite-difference scheme. Meanwhile, it is found that the replacement of ∇ .(λ ∇ T ) /∇ .(λ ∇ T ) ρ cV ρ cV with ∇ .(χ ∇ T ) leads to significant numerical errors and the error terms in the recovered macroscopic temperature equation also result in considerable errors.

VapeCons: E-cigarette user conventions

PubMed Central

Williams, Rebecca S.

2015-01-01

Introduction E-cigarette ‘vaping conventions’ provide a venue for user social networking, parties, and ‘try before you buy’ access to a wide range of e-cigarette products. This study identifies and describes vaping conventions, raising awareness of this potentially problematic practice. Methods Conventions were identified via Google searches in April and May 2014 and August 2015. Details captured included location, sponsors, admission cost, event features, and promotions. Results 41 distinct organizations have planned 90 vaping conventions in 37 different locations since 2010. Conventions promoted access to a wide range of product vendors, seminars, social interactions with other users, parties, gifts, vaping contests, and other events. E-cigarette use at conventions was encouraged. Conclusions Vaping conventions promote e-cigarette use and social norms without public health having a voice to educate attendees about negative consequences of use. Future research should focus on the effects of attending these conventions on attendees and on indoor air quality in vapor-filled convention rooms. PMID:26424201

VapeCons: E-cigarette user conventions.

PubMed

Williams, Rebecca S

2015-11-01

E-cigarette 'vaping conventions' provide a venue for user social networking, parties, and 'try before you buy' access to a wide range of e-cigarette products. This study identifies and describes vaping conventions, raising awareness of this potentially problematic practice. Conventions were identified via Google searches in April and May 2014 and August 2015. Details captured included location, sponsors, admission cost, event features, and promotions. 41 distinct organizations have planned 90 vaping conventions in 37 different locations since 2010. Conventions promoted access to a wide range of product vendors, seminars, social interactions with other users, parties, gifts, vaping contests, and other events. E-cigarette use at conventions was encouraged. Vaping conventions promote e-cigarette use and social norms without public health having a voice to educate attendees about negative consequences of use. Future research should focus on the effects of attending these conventions on attendees and on indoor air quality in vapor-filled convention rooms.

Nicotine Vapor Method to Induce Nicotine Dependence in Rodents.

PubMed

Kallupi, Marsida; George, Olivier

2017-07-05

Nicotine, the main addictive component of tobacco, induces potentiation of brain stimulation reward, increases locomotor activity, and induces conditioned place preference. Nicotine cessation produces a withdrawal syndrome that can be relieved by nicotine replacement therapy. In the last decade, the market for electronic cigarettes has flourished, especially among adolescents. The nicotine vaporizer or electronic nicotine delivery system is a battery-operated device that allows the user to simulate the experience of tobacco smoking without inhaling smoke. The device is designed to be an alternative to conventional cigarettes that emits vaporized nicotine inhaled by the user. This report describes a procedure to vaporize nicotine in the air to produce blood nicotine levels in rodents that are clinically relevant to those that are observed in humans and produce dependence. We also describe how to construct the apparatus to deliver nicotine vapor in a stable, reliable, and consistent manner, as well as how to analyze air for nicotine content. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Irradiation of fish fillets: Relation of vapor phase reactions to storage quality

USGS Publications Warehouse

Spinelli, J.; Dollar, A.M.; Wedemeyer, G.A.; Gallagher, E.C.

1969-01-01

Fish fillets irradiated under air, nitrogen, oxygen, or carbon dioxide atmospheres developed rancidlike flavors when they were stored at refrigerated temperatures. Packing and irradiating under vacuum or helium prevented development of off-flavors during storage.Significant quantities of nitrate and oxidizing substances were formed when oxygen, nitrogen, or air were present in the vapor or liquid phases contained in a Pyrex glass model system exposed to ionizing radiation supplied by a 60Co source. It was demonstrated that the delayed flavor changes that occur in stored fish fillets result from the reaction of vapor phase radiolysis products and the fish tissue substrates.

Evidence for extreme partitioning of copper into a magmatic vapor phase.

PubMed

Lowenstern, J B; Mahood, G A; Rivers, M L; Sutton, S R

1991-06-07

The discovery of copper sulfides in carbon dioxide- and chlorine-bearing bubbles in phenocryst-hosted melt inclusions shows that copper resides in a vapor phase in some shallow magma chambers. Copper is several hundred times more concentrated in magmatic vapor than in coexisting pantellerite melt. The volatile behavior of copper should be considered when modeling the volcanogenic contribution of metals to the atmosphere and may be important in the formation of copper porphyry ore deposits.

Predicting vapor-liquid phase equilibria with augmented ab initio interatomic potentials

NASA Astrophysics Data System (ADS)

Vlasiuk, Maryna; Sadus, Richard J.

2017-06-01

The ability of ab initio interatomic potentials to accurately predict vapor-liquid phase equilibria is investigated. Monte Carlo simulations are reported for the vapor-liquid equilibria of argon and krypton using recently developed accurate ab initio interatomic potentials. Seventeen interatomic potentials are studied, formulated from different combinations of two-body plus three-body terms. The simulation results are compared to either experimental or reference data for conditions ranging from the triple point to the critical point. It is demonstrated that the use of ab initio potentials enables systematic improvements to the accuracy of predictions via the addition of theoretically based terms. The contribution of three-body interactions is accounted for using the Axilrod-Teller-Muto plus other multipole contributions and the effective Marcelli-Wang-Sadus potentials. The results indicate that the predictive ability of recent interatomic potentials, obtained from quantum chemical calculations, is comparable to that of accurate empirical models. It is demonstrated that the Marcelli-Wang-Sadus potential can be used in combination with accurate two-body ab initio models for the computationally inexpensive and accurate estimation of vapor-liquid phase equilibria.

Predicting vapor-liquid phase equilibria with augmented ab initio interatomic potentials.

PubMed

Vlasiuk, Maryna; Sadus, Richard J

2017-06-28

The ability of ab initio interatomic potentials to accurately predict vapor-liquid phase equilibria is investigated. Monte Carlo simulations are reported for the vapor-liquid equilibria of argon and krypton using recently developed accurate ab initio interatomic potentials. Seventeen interatomic potentials are studied, formulated from different combinations of two-body plus three-body terms. The simulation results are compared to either experimental or reference data for conditions ranging from the triple point to the critical point. It is demonstrated that the use of ab initio potentials enables systematic improvements to the accuracy of predictions via the addition of theoretically based terms. The contribution of three-body interactions is accounted for using the Axilrod-Teller-Muto plus other multipole contributions and the effective Marcelli-Wang-Sadus potentials. The results indicate that the predictive ability of recent interatomic potentials, obtained from quantum chemical calculations, is comparable to that of accurate empirical models. It is demonstrated that the Marcelli-Wang-Sadus potential can be used in combination with accurate two-body ab initio models for the computationally inexpensive and accurate estimation of vapor-liquid phase equilibria.

Self-catalyzed GaAs nanowires on silicon by hydride vapor phase epitaxy.

PubMed

Dong, Zhenning; André, Yamina; Dubrovskii, Vladimir G; Bougerol, Catherine; Leroux, Christine; Ramdani, Mohammed R; Monier, Guillaume; Trassoudaine, Agnès; Castelluci, Dominique; Gil, Evelyne

2017-03-24

Gold-free GaAs nanowires on silicon substrates can pave the way for monolithic integration of photonic nanodevices with silicon electronic platforms. It is extensively documented that the self-catalyzed approach works well in molecular beam epitaxy but is much more difficult to implement in vapor phase epitaxies. Here, we report the first gallium-catalyzed hydride vapor phase epitaxy growth of long (more than 10 μm) GaAs nanowires on Si(111) substrates with a high integrated growth rate up to 60 μm h -1 and pure zincblende crystal structure. The growth is achieved by combining a low temperature of 600 °C with high gaseous GaCl/As flow ratios to enable dechlorination and formation of gallium droplets. GaAs nanowires exhibit an interesting bottle-like shape with strongly tapered bases, followed by straight tops with radii as small as 5 nm. We present a model that explains the peculiar growth mechanism in which the gallium droplets nucleate and rapidly swell on the silicon surface but then are gradually consumed to reach a stationary size. Our results unravel the necessary conditions for obtaining gallium-catalyzed GaAs nanowires by vapor phase epitaxy techniques.

Comparative Study of Solution Phase and Vapor Phase Deposition of Aminosilanes on Silicon Dioxide Surfaces

PubMed Central

Yadav, Amrita R.; Sriram, Rashmi; Carter, Jared A.; Miller, Benjamin L.

2014-01-01

The uniformity of aminosilane layers typically used for the modification of hydroxyl bearing surfaces such as silicon dioxide is critical for a wide variety of applications, including biosensors. However, in spite of many studies that have been undertaken on surface silanization, there remains a paucity of easy-to-implement deposition methods reproducibly yielding smooth aminosilane monolayers. In this study, solution- and vapor-phase deposition methods for three aminoalkoxysilanes differing in the number of reactive groups (3-aminopropyl triethoxysilane (APTES), 3-aminopropyl methyl diethoxysilane (APMDES) and 3-aminopropyl dimethyl ethoxysilane (APDMES)) were assessed with the aim of identifying methods that yield highly uniform and reproducible silane layers that are resistant to minor procedural variations. Silane film quality was characterized based on measured thickness, hydrophilicity and surface roughness. Additionally, hydrolytic stability of the films was assessed via these thickness and contact angle values following desorption in water. We found that two simple solution-phase methods, an aqueous deposition of APTES and a toluene based deposition of APDMES, yielded high quality silane layers that exhibit comparable characteristics to those deposited via vapor-phase methods. PMID:24411379

E-Cigarettes and Potential Implications for Plastic Surgery.

PubMed

Taub, Peter J; Matarasso, Alan

2016-12-01

The use of tobacco-based products, most notably cigarettes, is related directly to wound healing problems and poorer outcomes in plastic surgery. Current abstracts have highlighted the potential complications from nicotine, specifically following plastic surgery in patients who choose to smoke. Recently, products that use electricity to vaporize liquid nitrogen have been gaining popularity. New rules were recently proposed that would give the federal government authority over electronic cigarettes. However, the health-related issues surrounding e-cigarettes are still largely unknown or misunderstood. These issues also extend to their impact on surgical procedures, notably their effect on plastic surgical procedures that rely heavily on the vascularity of either the host wound bed or the replacement tissue.

The influence of liquid/vapor phase change onto the Nusselt number

NASA Astrophysics Data System (ADS)

Popescu, Elena-Roxana; Colin, Catherine; Tanguy, Sebastien

2017-11-01

In spite of its significant interest in various fields, there is currently a very few information on how an external flow will modify the evaporation or the condensation of a liquid surface. Although most applications involve turbulent flows, the simpler configuration where a laminar superheated or subcooled vapor flow is shearing a saturated liquid interface has still never been solved. Based on a numerical approach, we propose to characterize the interaction between a laminar boundary layer of a superheated or subcooled vapor flow and a static liquid pool at saturation temperature. By performing a full set of simulations sweeping the parameters space, correlations are proposed for the first time on the Nusselt number depending on the dimensionless numbers that characterize both vaporization and condensation. As attended, the Nusselt number decreases or increases in the configurations involving respectively vaporization or condensation. More unexpected is the behaviour of the friction of the vapor flow on the liquid pool, for which we report that it is weakly affected by the phase change, despite the important variation of the local flow structure due to evaporation or condensation.

Vaporous Marketing: Uncovering Pervasive Electronic Cigarette Advertisements on Twitter.

PubMed

Clark, Eric M; Jones, Chris A; Williams, Jake Ryland; Kurti, Allison N; Norotsky, Mitchell Craig; Danforth, Christopher M; Dodds, Peter Sheridan

2016-01-01

Twitter has become the "wild-west" of marketing and promotional strategies for advertisement agencies. Electronic cigarettes have been heavily marketed across Twitter feeds, offering discounts, "kid-friendly" flavors, algorithmically generated false testimonials, and free samples. All electronic cigarette keyword related tweets from a 10% sample of Twitter spanning January 2012 through December 2014 (approximately 850,000 total tweets) were identified and categorized as Automated or Organic by combining a keyword classification and a machine trained Human Detection algorithm. A sentiment analysis using Hedonometrics was performed on Organic tweets to quantify the change in consumer sentiments over time. Commercialized tweets were topically categorized with key phrasal pattern matching. The overwhelming majority (80%) of tweets were classified as automated or promotional in nature. The majority of these tweets were coded as commercialized (83.65% in 2013), up to 33% of which offered discounts or free samples and appeared on over a billion twitter feeds as impressions. The positivity of Organic (human) classified tweets has decreased over time (5.84 in 2013 to 5.77 in 2014) due to a relative increase in the negative words 'ban', 'tobacco', 'doesn't', 'drug', 'against', 'poison', 'tax' and a relative decrease in the positive words like 'haha', 'good', 'cool'. Automated tweets are more positive than organic (6.17 versus 5.84) due to a relative increase in the marketing words like 'best', 'win', 'buy', 'sale', 'health', 'discount' and a relative decrease in negative words like 'bad', 'hate', 'stupid', 'don't'. Due to the youth presence on Twitter and the clinical uncertainty of the long term health complications of electronic cigarette consumption, the protection of public health warrants scrutiny and potential regulation of social media marketing.

E-Cigarettes Use Behavior and Experience of Adults: Qualitative Research Findings to Inform E-Cigarette Use Measure Development.

PubMed

Kim, Hyoshin; Davis, Andrew H; Dohack, Jaime L; Clark, Pamela I

2017-02-01

To gain a better understanding of electronic cigarette (e-cigarette) use behavior and experience among adult e-cigarette users, with the goal of informing development of future e-cigarette use measures. Between August and October 2014 six focus groups were conducted in Seattle. Participants (63% male; 60% >35 years old; 60% White): e-cigarette users who used combustible tobacco products either currently or in the past. E-cigarette discussion topics covered: their daily use pattern (eg, frequency), product-related characteristics (eg, nicotine levels), and perceptions about health risks and benefits. Participants' descriptions of daily use were so varied that no common "unit" of a "session" easily summarized frequency or quantity of typical e-cigarette use. Most users had difficulty in tracking their own use. Participants reported nicotine craving relief when using e-cigarettes, but described e-cigarettes use as less satisfying than combustible cigarettes. Valued characteristics included "ready availability" and the possibility of using indoors. A unique aspect of the e-cigarette use experience is the option of adding flavors and having the ability to exhale "big clouds" of vapor/aerosol. Most perceived e-cigarettes as a better and safer alternative to conventional cigarettes, yet still sought further information about health consequences and safety of e-cigarettes from trusted sources. E-cigarettes users are far from homogeneous in their behavior and motivation for adopting e-cigarettes. A range of use patterns arising from both hedonic and utilitarian factors, along with product characteristics (eg, variable nicotine levels and flavors) extending beyond those of conventional cigarettes, suggest that new, specific e-cigarette use measures must be developed. The current study provides timely information on adult e-cigarette use behavior, which is a crucial step in measuring this new phenomenon and assessing the risks associated with using e-cigarette products. Our

E-Cigarettes Use Behavior and Experience of Adults: Qualitative Research Findings to Inform E-Cigarette Use Measure Development

PubMed Central

Davis, Andrew H.; Dohack, Jaime L.; Clark, Pamela I.

2017-01-01

Objectives: To gain a better understanding of electronic cigarette (e-cigarette) use behavior and experience among adult e-cigarette users, with the goal of informing development of future e-cigarette use measures. Methods: Between August and October 2014 six focus groups were conducted in Seattle. Participants (63% male; 60% >35 years old; 60% White): e-cigarette users who used combustible tobacco products either currently or in the past. E-cigarette discussion topics covered: their daily use pattern (eg, frequency), product-related characteristics (eg, nicotine levels), and perceptions about health risks and benefits. Results: Participants’ descriptions of daily use were so varied that no common “unit” of a “session” easily summarized frequency or quantity of typical e-cigarette use. Most users had difficulty in tracking their own use. Participants reported nicotine craving relief when using e-cigarettes, but described e-cigarettes use as less satisfying than combustible cigarettes. Valued characteristics included “ready availability” and the possibility of using indoors. A unique aspect of the e-cigarette use experience is the option of adding flavors and having the ability to exhale “big clouds” of vapor/aerosol. Most perceived e-cigarettes as a better and safer alternative to conventional cigarettes, yet still sought further information about health consequences and safety of e-cigarettes from trusted sources. Conclusions: E-cigarettes users are far from homogeneous in their behavior and motivation for adopting e-cigarettes. A range of use patterns arising from both hedonic and utilitarian factors, along with product characteristics (eg, variable nicotine levels and flavors) extending beyond those of conventional cigarettes, suggest that new, specific e-cigarette use measures must be developed. Implications: The current study provides timely information on adult e-cigarette use behavior, which is a crucial step in measuring this new

Sensitive and selective determination of polycyclic aromatic hydrocarbons in mainstream cigarette smoke using a graphene-coated solid-phase microextraction fiber prior to GC/MS.

PubMed

Wang, Xiaoyu; Wang, Yuan; Qin, Yaqiong; Ding, Li; Chen, Yi; Xie, Fuwei

2015-08-01

A simple method has been developed for the simultaneous determination of 16 polycyclic aromatic hydrocarbons (PAHs) in mainstream cigarette smoke. The procedure is based on employing a homemade graphene-coated solid-phase microextraction (SPME) fiber for extraction prior to GC/MS. In comparison to commercial 100-μm poly(dimethyl siloxane) (PDMS) fiber, the graphene-coated SPME fiber exhibits advantageous cleanup and preconcentration efficiencies. By collecting the particulate phase 5 cigarettes, the LODs and LOQs of 16 target PAHs were 0.02-0.07 and 0.07-0.22 ng/cigarette, respectively, and all of the linear correlation efficiencies were larger than 0.995. The validation results also indicate that the method has good repeatability (RSD between 4.2% and 9.5%) and accuracy (spiked recoveries between 80% and 110%). The developed method was applied to analyze two Kentucky reference cigarettes (1R5F and 3R4F) and six Chinese brands of cigarettes. In addition, the PAH concentrations in the particulate phase of the smoke from the 1R5F Kentucky cigarettes were in good agreement with recently reported results. Due to easy operation and good validation results, this SPME-GC/MS method may be an excellent alternative for trace analysis of PAHs in cigarette smoke. Copyright © 2015 Elsevier B.V. All rights reserved.

E-cigarette Nicotine Delivery: Data and Learnings from Pharmacokinetic Studies.

PubMed

Fearon, Ian M; Eldridge, Alison; Gale, Nathan; Shepperd, Christopher J; McEwan, Mike; Camacho, Oscar M; Nides, Mitch; McAdam, Kevin; Proctor, Christopher J

2017-01-01

E-cigarettes could potentially play a major role in tobacco harm reduction by delivering nicotine in a vapor containing significantly fewer toxicants than cigarette smoke and may aid smoking behavior changes such as reduction or cessation. We examined blood nicotine levels in smokers who were non-accustomed to e-cigarette use (Study 1) and accustomed e-cigarette users (Study 2). We compared nicotine levels when participants used a closed modular system e-cigarette to those when participants smoked a cigarette. In Study 1, Cmax (geometric mean (CV)) during a 5-minute puffing period (10 puffs, 30 seconds apart) was 13.4 (51.4) ng/ ml for a regular cigarette. The e-cigarette Cmax was significantly lower (p .05) at 2.5 (67.8) ng/ml. In Study 2, during a 5-minute ad libitum puffing period, cigarette Cmax was 7.2 (130.8) ng/mL, and it was 7.8 (108.2) ng/mL for the e-cigarette. Our data demonstrate heterogeneity of nicotine deliveries both between products and also with the same products used by different cohorts, eg, accustomed users versus smokers. Such differences must be taken into account when determining the likely behavioral impact, on smoking reduction and cessation, of nicotine delivery data and when planning e-cigarette nicotine pharmacokinetic studies.

Superfluid helium 2 liquid-vapor phase separation: Technology assessment

NASA Technical Reports Server (NTRS)

Lee, J. M.

1984-01-01

A literature survey of helium 2 liquid vapor phase separation is presented. Currently, two types of He 2 phase separators are being investigated: porous, sintered metal plugs and the active phase separator. The permeability K(P) shows consistency in porous plug geometric characterization. Both the heat and mass fluxes increase with K(P). Downstream pressure regulation to adjust for varying heat loads and both temperatures is possible. For large dynamic heat loads, the active phase separator shows a maximum heat rejection rate of up to 2 W and bath temperature stability of 0.1 mK. Porous plug phase separation performance should be investigated for application to SIRTF and, in particular, that plugs of from 10 to the minus ninth square centimeters to 10 to the minus eighth square centimeters in conjunction with downstream pressure regulation be studied.

Comparative study of solution-phase and vapor-phase deposition of aminosilanes on silicon dioxide surfaces.

PubMed

Yadav, Amrita R; Sriram, Rashmi; Carter, Jared A; Miller, Benjamin L

2014-02-01

The uniformity of aminosilane layers typically used for the modification of hydroxyl bearing surfaces such as silicon dioxide is critical for a wide variety of applications, including biosensors. However, in spite of many studies that have been undertaken on surface silanization, there remains a paucity of easy-to-implement deposition methods reproducibly yielding smooth aminosilane monolayers. In this study, solution- and vapor-phase deposition methods for three aminoalkoxysilanes differing in the number of reactive groups (3-aminopropyl triethoxysilane (APTES), 3-aminopropyl methyl diethoxysilane (APMDES) and 3-aminopropyl dimethyl ethoxysilane (APDMES)) were assessed with the aim of identifying methods that yield highly uniform and reproducible silane layers that are resistant to minor procedural variations. Silane film quality was characterized based on measured thickness, hydrophilicity and surface roughness. Additionally, hydrolytic stability of the films was assessed via these thickness and contact angle values following desorption in water. We found that two simple solution-phase methods, an aqueous deposition of APTES and a toluene based deposition of APDMES, yielded high quality silane layers that exhibit comparable characteristics to those deposited via vapor-phase methods. Copyright © 2013 Elsevier B.V. All rights reserved.

Plasma Spray-PVD: A New Thermal Spray Process to Deposit Out of the Vapor Phase

NASA Astrophysics Data System (ADS)

von Niessen, Konstantin; Gindrat, Malko

2011-06-01

Plasma spray-physical vapor deposition (PS-PVD) is a low pressure plasma spray technology recently developed by Sulzer Metco AG (Switzerland). Even though it is a thermal spray process, it can deposit coatings out of the vapor phase. The basis of PS-PVD is the low pressure plasma spraying (LPPS) technology that has been well established in industry for several years. In comparison to conventional vacuum plasma spraying (VPS) or low pressure plasma spraying (LPPS), the new proposed process uses a high energy plasma gun operated at a reduced work pressure of 0.1 kPa (1 mbar). Owing to the high energy plasma and further reduced work pressure, PS-PVD is able to deposit a coating not only by melting the feed stock material which builds up a layer from liquid splats but also by vaporizing the injected material. Therefore, the PS-PVD process fills the gap between the conventional physical vapor deposition (PVD) technologies and standard thermal spray processes. The possibility to vaporize feedstock material and to produce layers out of the vapor phase results in new and unique coating microstructures. The properties of such coatings are superior to those of thermal spray and electron beam-physical vapor deposition (EB-PVD) coatings. In contrast to EB-PVD, PS-PVD incorporates the vaporized coating material into a supersonic plasma plume. Owing to the forced gas stream of the plasma jet, complex shaped parts such as multi-airfoil turbine vanes can be coated with columnar thermal barrier coatings using PS-PVD. Even shadowed areas and areas which are not in the line of sight of the coating source can be coated homogeneously. This article reports on the progress made by Sulzer Metco in developing a thermal spray process to produce coatings out of the vapor phase. Columnar thermal barrier coatings made of Yttria-stabilized Zircona (YSZ) are optimized to serve in a turbine engine. This process includes not only preferable coating properties such as strain tolerance and erosion

Vaporous Marketing: Uncovering Pervasive Electronic Cigarette Advertisements on Twitter

PubMed Central

Jones, Chris A.; Williams, Jake Ryland; Kurti, Allison N.; Norotsky, Mitchell Craig; Danforth, Christopher M.; Dodds, Peter Sheridan

2016-01-01

Background Twitter has become the “wild-west” of marketing and promotional strategies for advertisement agencies. Electronic cigarettes have been heavily marketed across Twitter feeds, offering discounts, “kid-friendly” flavors, algorithmically generated false testimonials, and free samples. Methods All electronic cigarette keyword related tweets from a 10% sample of Twitter spanning January 2012 through December 2014 (approximately 850,000 total tweets) were identified and categorized as Automated or Organic by combining a keyword classification and a machine trained Human Detection algorithm. A sentiment analysis using Hedonometrics was performed on Organic tweets to quantify the change in consumer sentiments over time. Commercialized tweets were topically categorized with key phrasal pattern matching. Results The overwhelming majority (80%) of tweets were classified as automated or promotional in nature. The majority of these tweets were coded as commercialized (83.65% in 2013), up to 33% of which offered discounts or free samples and appeared on over a billion twitter feeds as impressions. The positivity of Organic (human) classified tweets has decreased over time (5.84 in 2013 to 5.77 in 2014) due to a relative increase in the negative words ‘ban’, ‘tobacco’, ‘doesn’t’, ‘drug’, ‘against’, ‘poison’, ‘tax’ and a relative decrease in the positive words like ‘haha’, ‘good’, ‘cool’. Automated tweets are more positive than organic (6.17 versus 5.84) due to a relative increase in the marketing words like ‘best’, ‘win’, ‘buy’, ‘sale’, ‘health’, ‘discount’ and a relative decrease in negative words like ‘bad’, ‘hate’, ‘stupid’, ‘don’t’. Conclusions Due to the youth presence on Twitter and the clinical uncertainty of the long term health complications of electronic cigarette consumption, the protection of public health warrants scrutiny and potential regulation of social media

Wetting phenomenon in the liquid-vapor phase coexistence of a partially miscible Lennard-Jones binary mixture

NASA Astrophysics Data System (ADS)

Ramírez-Santiago, Guillermo; Díaz-Herrera, Enrique; Moreno Razo, José A.

2004-03-01

We have carried out extensive equilibrium MD simulations to study wetting phenomena in the liquid-vapor phase coexistence of a partially miscible binary LJ mixture. We find that in the temperature range 0.60 ≤ T^* < 0.80, the system separates forming a liquid A-liquid B interface in coexistence with the vapor phase. At higher temperatures, 0.80 ≤ T^* < 1.25 the liquid phases are wet by the vapor phase. By studying the behavior of the surface tension as a function of temperature we estimate the wetting transition temperature (WTT) to be T^*_w≃ 0.80. The adsorption of molecules at the liquid-liquid interface shows a discontinuity at about T^*≃ 0.79 suggesting that the wetting transition is a first order phase transition. These results are in agreement with some experiments carried out in fluid binary mixtures. In addition, we estimated the consolute temperature to be T^* _cons≃ 1.25. The calculated phase diagram of the mixture suggest the existence of a tricritical point.

Preliminary validity of the modified Cigarette Evaluation Questionnaire in predicting the reinforcing effects of cigarettes that vary in nicotine content.

PubMed

Arger, Christopher A; Heil, Sarah H; Sigmon, Stacey C; Tidey, Jennifer W; Stitzer, Maxine L; Gaalema, Diann E; Durand, Hanna J; Bunn, Janice Y; Ruggieri, Elizabeth K; Higgins, Stephen T

2017-12-01

Validity studies evaluating self-report measures in relation to behavioral preference of cigarettes varying in nicotine content are needed. The current study examined the relationship between ratings on the modified Cigarette Evaluation Questionnaire (mCEQ) and the relative reinforcing effects of Spectrum research cigarettes (15.8, 5.2, 2.4, 0.4 mg per gram of tobacco). Data for this secondary analysis were obtained from a double-blind study (Higgins et al., 2017) evaluating the subjective and reinforcing effects of Spectrum cigarettes under acute smoking abstinence. Current smokers (N = 26) were recruited from three vulnerable smoking populations (economically disadvantaged women of reproductive age, opioid-maintained individuals, individuals with affective disorders). In Phase 1 (five sessions), the mCEQ (Satisfaction, Psychological Reward, Enjoyment of Respiratory Tract Sensations, Craving Reduction, Aversion subscales) was administered following ad lib smoking of Spectrum cigarettes and subscale differences scores were calculated by subtracting ratings of the 15.8 mg/g cigarette from ratings of the reduced nicotine content cigarettes. In Phase 2 (six sessions), participants completed six 2-dose concurrent choice tests. The relationship between mCEQ subscale difference scores from Phase 1 and nicotine dose choice from Phase 2 was examined using mixed-model repeated-measures analyses of variance. Higher Satisfaction and lower Aversion subscale difference scores were associated with choosing the 15.8 mg/g cigarette more than the 5.2, 2.4, and 0.4 mg/g cigarettes. Scores on the other mCEQ subscales were not associated with nicotine choice. These results provide support for validity of the mCEQ Satisfaction and Aversion subscales predicting the relative reinforcing effects and abuse liability of varying nicotine content cigarettes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Comparison of cryopreserved human sperm in vapor and liquid phases of liquid nitrogen: effect on motility parameters, morphology, and sperm function.

PubMed

Punyatanasakchai, Piyaphan; Sophonsritsuk, Areephan; Weerakiet, Sawaek; Wansumrit, Surapee; Chompurat, Deonthip

2008-11-01

To compare the effects of cryopreserved sperm in vapor and liquid phases of liquid nitrogen on sperm motility, morphology, and sperm function. Experimental study. Andrology laboratory at Ramathibodi Hospital, Thailand. Thirty-eight semen samples with normal motility and sperm count were collected from 38 men who were either patients of an infertility clinic or had donated sperm for research. Each semen sample was divided into two aliquots. Samples were frozen with static-phase vapor cooling. One aliquot was plunged into liquid nitrogen (-196 degrees C), and the other was stored in vapor-phase nitrogen (-179 degrees C) for 3 days. Thawing was performed at room temperature. Motility was determined by using computer-assisted semen analysis, sperm morphology was determined by using eosin-methylene blue staining, and sperm function was determined by using a hemizona binding test. Most of the motility parameters of sperm stored in the vapor phase were not significantly different from those stored in the liquid phase of liquid nitrogen, except in amplitude of lateral head displacement. The percentages of normal sperm morphology in both vapor and liquid phases also were not significantly different. There was no significant difference in the number of bound sperm in hemizona between sperm cryopreserved in both vapor and liquid phases of liquid nitrogen. Cryopreservation of human sperm in a vapor phase of liquid nitrogen was comparable to cryopreservation in a liquid phase of liquid nitrogen.

Mining social media data for opinion polarities about electronic cigarettes.

PubMed

Dai, Hongying; Hao, Jianqiang

2017-03-01

There is an ongoing debate about harm and benefit of e-cigarettes, usage of which has rapidly increased in recent years. By separating non-commercial (organic) tweets from commercial tweets, we seek to evaluate the general public's attitudes towards e-cigarettes. We collected tweets containing the words 'e-cig', 'e-cigarette', 'e-liquid', 'vape', 'vaping', 'vapor' and 'vaporizer' from 23 July to 14 October 2015 (n=757 167). A multilabel Naïve Bayes model was constructed to classify tweets into 5 polarities (against, support, neutral, commercial, irrelevant). We further analysed the prevalence of e-cigarette tweets, geographic variations in these tweets and the impact of socioeconomic factors on the public attitudes towards e-cigarettes. Opinions from organic tweets about e-cigarettes were mixed (against 17.7%, support 10.8% and neutral 19.4%). The organic-against tweets delivered strong educational information about the risks of e-cigarette use and advocated for the general public, especially youth, to stop vaping. However, the organic-against tweets were outnumbered by commercial tweets and organic-support tweets by a ratio of over 1 to 3. Higher prevalence of organic tweets was associated with states with higher education rates (r=0.60, p<0.0001), higher percentage of black and African-American population (r=0.34, p=0.01), and higher median household income (r=0.33, p=0.02). The support rates for e-cigarettes were associated with states with fewer persons under 18 years old (r=-0.33, p=0.02) and a higher percentage of female population (r=0.3, p=0.02). The organic-against tweets raised public awareness of potential health risks and could aid in preventing non-smokers, adolescents and young adults from using e-cigarettes. Opinion polarities about e-cigarettes from social networks could be highly influential to the general public, especially youth. Further educational campaigns should include measuring their effectiveness. Published by the BMJ Publishing Group

Sol–gel synthesis of MCM-41 silicas and selective vapor-phase modification of their surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roik, N.V., E-mail: roik_nadya@ukr.net; Belyakova, L.A.

2013-11-15

Silica particles with uniform hexagonal mesopore architecture were synthesized by template directed sol–gel condensation of tetraethoxysilane or mixture of tetraethoxysilane and (3-chloropropyl)triethoxysilane in a water–ethanol–ammonia solution. Selective functionalization of exterior surface of parent materials was carried out by postsynthetic treatment of template-filled MCM-41 and Cl-MCM-41 with vapors of (3-chloropropyl)triethoxysilane and 1,2-ethylenediamine in vacuum. The chemical composition of obtained mesoporous silicas was estimated by IR spectroscopy and chemical analysis of surface products of reactions. Characteristics of porous structure of resulting materials were determined from the data of X-ray, low-temperature nitrogen ad-desorption and transmission electron microscopy measurements. Obtained results confirm invariability ofmore » highly ordered mesoporous structure of MCM-41 and Cl-MCM-41 after their selective postsynthetic modification in vapor phase. It was proved that proposed method of vapor-phase functionalization of template-filled starting materials is not accompanied by dissolution of the template and chemical modification of pores surface. This provides preferential localization of grafted functional groups onto the exterior surface of mesoporous silicas. - Graphical abstract: Sol–gel synthesis and postsynthetic chemical modification of template-filled MCM-41 and Cl-MCM-41 with (3-chloropropyl)triethoxysilane and 1,2-ethylenediamine in vapor phase. Display Omitted - Highlights: • Synthesis of MCM-41 silica by template directed sol–gel condensation. • Selective vapor-phase functionalization of template-filled silica particles. • Preferential localization of grafted groups onto the exterior surface of mesoporous silicas.« less

Role of Co-Vapors in Vapor Deposition Polymerization

PubMed Central

Lee, Ji Eun; Lee, Younghee; Ahn, Ki-Jin; Huh, Jinyoung; Shim, Hyeon Woo; Sampath, Gayathri; Im, Won Bin; Huh, Yang–Il; Yoon, Hyeonseok

2015-01-01

Polypyrrole (PPy)/cellulose (PPCL) composite papers were fabricated by vapor phase polymerization. Importantly, the vapor-phase deposition of PPy onto cellulose was assisted by employing different co-vapors namely methanol, ethanol, benzene, water, toluene and hexane, in addition to pyrrole. The resulting PPCL papers possessed high mechanical flexibility, large surface-to-volume ratio, and good redox properties. Their main properties were highly influenced by the nature of the co-vaporized solvent. The morphology and oxidation level of deposited PPy were tuned by employing co-vapors during the polymerization, which in turn led to change in the electrochemical properties of the PPCL papers. When methanol and ethanol were used as co-vapors, the conductivities of PPCL papers were found to have improved five times, which was likely due to the enhanced orientation of PPy chain by the polar co-vapors with high dipole moment. The specific capacitance of PPCL papers obtained using benzene, toluene, water and hexane co-vapors was higher than those of the others, which is attributed to the enlarged effective surface area of the electrode material. The results indicate that the judicious choice and combination of co-vapors in vapor-deposition polymerization (VDP) offers the possibility of tuning the morphological, electrical, and electrochemical properties of deposited conducting polymers. PMID:25673422

Pediatrician Knowledge, Attitudes, and Practice Related to Electronic Cigarettes.

PubMed

Gorzkowski, Julie A; Whitmore, Regina M; Kaseeska, Kristen R; Brishke, Janet K; Klein, Jonathan D

2016-07-01

Electronic cigarettes (e-cigarettes) have grown rapidly in popularity, creating concerns for pediatricians and families. Evaluating pediatricians' understanding of e-cigarettes is an important first step in effectively addressing these products in practice. This qualitative study assesses pediatricians' knowledge, attitudes, and current clinical practices related to e-cigarettes. We conducted six focus groups with 37 pediatric clinicians in 2014. Groups were led by a trained facilitator using a semistructured discussion guide. Responses were recorded, transcribed, and coded to identify relevant themes. Pediatricians know that e-cigarettes generally contain nicotine and that adolescents and young adults are most likely to use them. However, most feel uninformed about the health effects of e-cigarettes and report wanting scientific evidence for safety or harm from credible sources. Pediatricians are skeptical of claims that e-cigarettes are safe, either for users or for those exposed to second-hand e-cigarette vapor or emissions. Participants noted that clinical conversations about e-cigarettes were rare, citing barriers including a lack of systematic screening, competing priorities during clinical visits, and, for some, limited confidence in their ability to address e-cigarettes during clinical encounters. No participants recommended e-cigarettes for cessation. Pediatricians feel poorly informed about e-cigarettes and are concerned about their potential health effects. While clinical discussions about e-cigarettes are rare, recent increases in their use leaves many clinicians wanting guidance about what to say to patients and families. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Electronic cigarettes and thirdhand tobacco smoke: two emerging health care challenges for the primary care provider.

PubMed

Kuschner, Ware G; Reddy, Sunayana; Mehrotra, Nidhi; Paintal, Harman S

2011-02-01

PRIMARY CARE PROVIDERS SHOULD BE AWARE OF TWO NEW DEVELOPMENTS IN NICOTINE ADDICTION AND SMOKING CESSATION: 1) the emergence of a novel nicotine delivery system known as the electronic (e-) cigarette; and 2) new reports of residual environmental nicotine and other biopersistent toxicants found in cigarette smoke, recently described as "thirdhand smoke". The purpose of this article is to provide a clinician-friendly introduction to these two emerging issues so that clinicians are well prepared to counsel smokers about newly recognized health concerns relevant to tobacco use. E-cigarettes are battery powered devices that convert nicotine into a vapor that can be inhaled. The World Health Organization has termed these devices electronic nicotine delivery systems (ENDS). The vapors from ENDS are complex mixtures of chemicals, not pure nicotine. It is unknown whether inhalation of the complex mixture of chemicals found in ENDS vapors is safe. There is no evidence that e-cigarettes are effective treatment for nicotine addiction. ENDS are not approved as smoking cessation devices. Primary care givers should anticipate being questioned by patients about the advisability of using e-cigarettes as a smoking cessation device. The term thirdhand smoke first appeared in the medical literature in 2009 when investigators introduced the term to describe residual tobacco smoke contamination that remains after the cigarette is extinguished. Thirdhand smoke is a hazardous exposure resulting from cigarette smoke residue that accumulates in cars, homes, and other indoor spaces. Tobacco-derived toxicants can react to form potent cancer causing compounds. Exposure to thirdhand smoke can occur through the skin, by breathing, and by ingestion long after smoke has cleared from a room. Counseling patients about the hazards of thirdhand smoke may provide additional motivation to quit smoking.

Overview: Homogeneous nucleation from the vapor phase-The experimental science.

PubMed

Wyslouzil, Barbara E; Wölk, Judith

2016-12-07

Homogeneous nucleation from the vapor phase has been a well-defined area of research for ∼120 yr. In this paper, we present an overview of the key experimental and theoretical developments that have made it possible to address some of the fundamental questions first delineated and investigated in C. T. R. Wilson's pioneering paper of 1897 [C. T. R. Wilson, Philos. Trans. R. Soc., A 189, 265-307 (1897)]. We review the principles behind the standard experimental techniques currently used to measure isothermal nucleation rates, and discuss the molecular level information that can be extracted from these measurements. We then highlight recent approaches that interrogate the vapor and intermediate clusters leading to particle formation, more directly.

The electronic cigarette. Official statement of the Spanish Society of Pneumology and Thoracic Surgery (SEPAR) on the efficacy, safety and regulation of electronic cigarettes.

PubMed

Jimenez Ruiz, Carlos A; Solano Reina, Segismundo; de Granda Orive, Jose Ignacio; Signes-Costa Minaya, Jaime; de Higes Martinez, Eva; Riesco Miranda, Juan Antonio; Altet Gómez, Neus; Lorza Blasco, Jose Javier; Barrueco Ferrero, Miguel; de Lucas Ramos, Pilar

2014-08-01

The electronic cigarette (EC) is a device formed by three basic elements: battery, atomizer and cartridge. When assembled, it looks like a cigarette. The cartridge contains different substances: propylene glycol, glycerine and, sometimes, nicotine. When the user "vapes", the battery is activated, the atomizer is heated and the liquid is drawn in and vaporized. The smoker inhales the mist produced. Various substances have been detected in this mist: formaldehyde, acetaldehyde and acrolein and some heavy metals. Although these are found in lower concentrations than in cigarettes, they may still be harmful for the human body. Several surveys show that 3-10% of smokers regularly use e-cigarettes. A randomized study has shown that the efficacy of e-cigarettes for helping smokers to quit is similar to nicotine patches. Nevertheless, the study has relevant methodological limitations and reliable conclusions cannot be deduced. This report sets down the Position Statement of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) on the efficacy and safety of e-cigarettes. This statement declares that e-cigarettes should be regulated as medicinal products. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

Enhanced Vapor-Phase Diffusion in Porous Media - LDRD Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, C.K.; Webb, S.W.

1999-01-01

As part of the Laboratory-Directed Research and Development (LDRD) Program at Sandia National Laboratories, an investigation into the existence of enhanced vapor-phase diffusion (EVD) in porous media has been conducted. A thorough literature review was initially performed across multiple disciplines (soil science and engineering), and based on this review, the existence of EVD was found to be questionable. As a result, modeling and experiments were initiated to investigate the existence of EVD. In this LDRD, the first mechanistic model of EVD was developed which demonstrated the mechanisms responsible for EVD. The first direct measurements of EVD have also been conductedmore » at multiple scales. Measurements have been made at the pore scale, in a two- dimensional network as represented by a fracture aperture, and in a porous medium. Significant enhancement of vapor-phase transport relative to Fickian diffusion was measured in all cases. The modeling and experimental results provide additional mechanisms for EVD beyond those presented by the generally accepted model of Philip and deVries (1957), which required a thermal gradient for EVD to exist. Modeling and experimental results show significant enhancement under isothermal conditions. Application of EVD to vapor transport in the near-surface vadose zone show a significant variation between no enhancement, the model of Philip and deVries, and the present results. Based on this information, the model of Philip and deVries may need to be modified, and additional studies are recommended.« less

Space cryogenics components based on the thermomechanical effect - Vapor-liquid phase separation

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Frederking, T. H. K.

1989-01-01

Applications of the thermomechanical effect has been qualified including incorporation in large-scale space systems in the area of vapor-liquid phase separation (VLPS). The theory of the porous-plug phase separator is developed for the limit of a high thermal impedance of the solid-state grains. Extensions of the theory of nonlinear turbulent flow are presented based on experimental results.

Vapors-liquid phase separator. [infrared telescope heat sink

NASA Technical Reports Server (NTRS)

Frederking, T. H. K.; Brown, G. S.; Chuang, C.; Kamioka, Y.; Kim, Y. I.; Lee, J. M.; Yuan, S. W. K.

1980-01-01

The use of porous plugs, mostly with in the form of passive devices with constant area were considered as vapor-liquid phase separators for helium 2 storage vessels under reduced gravity. The incorporation of components with variable cross sectional area as a method of flow rate modification was also investigated. A particular device which uses a shutter-type system for area variation was designed and constructed. This system successfully permitted flor rate changes of up to plus or minus 60% from its mean value.

Biodegradation of vapor-phase toluene in unsaturated porous media: Column experiments.

PubMed

Khan, Ali M; Wick, Lukas Y; Harms, Hauke; Thullner, Martin

2016-04-01

Biodegradation of organic chemicals in the vapor phase of soils and vertical flow filters has gained attention as promising approach to clean up volatile organic compounds (VOC). The drivers of VOC biodegradation in unsaturated systems however still remain poorly understood. Here, we analyzed the processes controlling aerobic VOC biodegradation in a laboratory setup mimicking the unsaturated zone above a shallow aquifer. The setup allowed for diffusive vapor-phase transport and biodegradation of three VOC: non-deuterated and deuterated toluene as two compounds of highly differing biodegradability but (nearly) identical physical and chemical properties, and MTBE as (at the applied experimental conditions) non-biodegradable tracer and internal control. Our results showed for toluene an effective microbial degradation within centimeter VOC transport distances despite high gas-phase diffusivity. Degradation rates were controlled by the reactivity of the compounds while oxic conditions were found everywhere in the system. This confirms hypotheses that vadose zone biodegradation rates can be extremely high and are able to prevent the outgassing of VOC to the atmosphere within a centimeter range if compound properties and site conditions allow for sufficiently high degradation rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of heated vapor-phase acidification on organic carbon concentrations and isotopic values in geologic rock samples

NASA Astrophysics Data System (ADS)

Wang, R. Z.; West, A. J.; Yager, J. A.; Rollins, N.; Li, G.; Berelson, W.

2016-12-01

Carbon signatures recorded in the modern and geologic rock record can give insight on the Earth's carbon cycle through time. This is especially true for organic carbon (OC), which can help us understand how the biosphere has evolved over Earth's history. However, carbon recorded in rocks is a combination of OC and inorganic carbon (IC) mostly in the form of carbonate minerals. To measure OC, IC must therefore first be removed through a process called "decarbonation." This is often done through a leaching process with hydrochloric acid (HCl). However, three well known problems exist for the decarbonation process: 1) Incomplete removal of IC, 2) Unintentional removal of OC, and 3) Addition of false carbon blank. Currently, vapor (gas) phase removal of OC is preferred to liquid phase treatment because it has been shown that OC is lost to solubilization during liquid phase acidification. Vapor phase treatment is largely thought to avoid the problem of OC loss, but this has not yet been rigorously investigated. This study investigates that assumption and shows that vapor phase treatment can cause unintentional OC loss. We show that vapor phase treatment must be sensitive to rock type and treatment length to produce robust OC isotopic measurements and concentrations.

Liquid-vapor phase equilibria and the thermodynamic properties of 2-methylpropanol- n-alkyl propanoate solutions

NASA Astrophysics Data System (ADS)

Suntsov, Yu. K.; Goryunov, V. A.; Chuikov, A. M.; Meshcheryakov, A. V.

2016-08-01

The boiling points of solutions of five binary systems are measured via ebulliometry in the pressure range of 2.05-103.3 kPa. Equilibrium vapor phase compositions, the values of the excess Gibbs energies, enthalpies, and entropies of solution of these systems are calculated. Patterns in the changes of phase equilibria and thermodynamic properties of solutions are established, depending on the compositions and temperatures of the systems. Liquid-vapor equilibria in the systems are described using the equations of Wilson and the NRTL (Non-Random Two-Liquid Model).

Vapor-phase infrared laser spectroscopy: from gas sensing to forensic urinalysis.

PubMed

Bartlome, Richard; Rey, Julien M; Sigrist, Markus W

2008-07-15

Numerous gas-sensing devices are based on infrared laser spectroscopy. In this paper, the technique is further developed and, for the first time, applied to forensic urinalysis. For this purpose, a difference frequency generation laser was coupled to an in-house-built, high-temperature multipass cell (HTMC). The continuous tuning range of the laser was extended to 329 cm(-1) in the fingerprint C-H stretching region between 3 and 4 microm. The HTMC is a long-path absorption cell designed to withstand organic samples in the vapor phase (Bartlome, R.; Baer, M.; Sigrist, M. W. Rev. Sci. Instrum. 2007, 78, 013110). Quantitative measurements were taken on pure ephedrine and pseudoephedrine vapors. Despite featuring similarities, the vapor-phase infrared spectra of these diastereoisomers are clearly distinguishable with respect to a vibrational band centered at 2970.5 and 2980.1 cm(-1), respectively. Ephedrine-positive and pseudoephedrine-positive urine samples were prepared by means of liquid-liquid extraction and directly evaporated in the HTMC without any preliminary chromatographic separation. When 10 or 20 mL of ephedrine-positive human urine is prepared, the detection limit of ephedrine, prohibited in sports as of 10 microg/mL, is 50 or 25 microg/mL, respectively. The laser spectrometer has room for much improvement; its potential is discussed with respect to doping agents detection.

External fuel vaporization study, phase 1

NASA Technical Reports Server (NTRS)

Szetela, E. J.; Chiappetta, L.

1980-01-01

A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

Phagocytosis and Inflammation: Exploring the effects of the components of E-cigarette vapor on macrophages.

PubMed

Ween, Miranda P; Whittall, Jonathan J; Hamon, Rhys; Reynolds, Paul N; Hodge, Sandra J

2017-08-01

E-cigarettes are perceived as harmless; however, evidence of their safety is lacking. New data suggests E-cigarettes discharge a range of compounds capable of physiological damage to users. We previously established that cigarette smoke caused defective alveolar macrophage phagocytosis. The present study compared the effect E-cigarette of components; E-liquid flavors, nicotine, vegetable glycerine, and propylene glycol on phagocytosis, proinflammatory cytokine secretion, and phagocytic recognition molecule expression using differentiated THP-1 macrophages. Similar to CSE, phagocytosis of NTHi bacteria was significantly decreased by E-liquid flavoring (11.65-15.75%) versus control (27.01%). Nicotine also decreased phagocytosis (15.26%). E-liquid, nicotine, and E-liquid+ nicotine reduced phagocytic recognition molecules; SR-A1 and TLR-2. IL-8 secretion increased with flavor and nicotine, while TNF α , IL-1 β , IL-6, MIP-1 α , MIP-1 β , and MCP-1 decreased after exposure to most flavors and nicotine. PG, VG, or PG:VG mix also induced a decrease in MIP-1 α and MIP-1 β We conclude that E-cigarettes can cause macrophage phagocytic dysfunction, expression of phagocytic recognition receptors and cytokine secretion pathways. As such, E-cigarettes should be treated with caution by users, especially those who are nonsmokers. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Modeling of Gallium Nitride Hydride Vapor Phase Epitaxy

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

1997-01-01

A reactor model for the hydride vapor phase epitaxy of GaN is presented. The governing flow, energy, and species conservation equations are solved in two dimensions to examine the growth characteristics as a function of process variables and reactor geometry. The growth rate varies with GaCl composition but independent of NH3 and H2 flow rates. A change in carrier gas for Ga source from H2 to N2 affects the growth rate and uniformity for a fixed reactor configuration. The model predictions are in general agreement with observed experimental behavior.

Phase-transition thresholds and vaporization phenomena for ultrasound phase-change nanoemulsions assessed via high speed optical microscopy

PubMed Central

Sheeran, Paul S.; Matsunaga, Terry O.; Dayton, Paul A.

2015-01-01

Ultrasonically activated phase-change contrast agents (PCCAs) based on perfluorocarbon droplets have been proposed for a variety of therapeutic and diagnostic clinical applications. When generated at the nanoscale, droplets may be small enough to exit the vascular space and then be induced to vaporize with high spatial and temporal specificity by externally-applied ultrasound. The use of acoustical techniques for optimizing ultrasound parameters for given applications can be a significant challenge for nanoscale PCCAs due to the contributions of larger outlier droplets. Similarly, optical techniques can be a challenge due to the sub-micron size of nanodroplet agents and resolution limits of optical microscopy. In this study, an optical method for determining activation thresholds of nanoscale emulsions based on the in vitro distribution of bubbles resulting from vaporization of PCCAs after single, short (<10 cycles) ultrasound pulses is evaluated. Through ultra-high-speed microscopy it is shown that the bubbles produced early in the pulse from vaporized droplets are strongly affected by subsequent cycles of the vaporization pulse, and these effects increase with pulse length. Results show that decafluorobutane nanoemulsions with peak diameters on the order of 200 nm can be optimally vaporized with short pulses using pressures amenable to clinical diagnostic ultrasound machines. PMID:23760161

Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations

PubMed Central

Peace, Michelle R.; Baird, Tyson R.; Smith, Nathaniel; Wolf, Carl E.; Poklis, Justin L.; Poklis, Alphonse

2016-01-01

Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography–tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography–mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations. PMID:27165804

Phase Equilibrium of TiO2 Nanocrystals in Flame-Assisted Chemical Vapor Deposition.

PubMed

Liu, Changran; Camacho, Joaquin; Wang, Hai

2018-01-19

Nano-scale titanium oxide (TiO 2 ) is a material useful for a wide range of applications. In a previous study, we showed that TiO 2 nanoparticles of both rutile and anatase crystal phases could be synthesized over the size range of 5 to 20 nm in flame-assisted chemical vapor deposition. Rutile was unexpectedly dominant in oxygen-lean synthesis conditions, whereas anatase is the preferred phase in oxygen-rich gases. The observation is in contrast to the 14 nm rutile-anatase crossover size derived from the existing crystal-phase equilibrium model. In the present work, we made additional measurements over a wider range of synthesis conditions; the results confirm the earlier observations. We propose an improved model for the surface energy that considers the role of oxygen desorption at high temperatures. The model successfully explains the observations made in the current and previous work. The current results provide a useful path to designing flame-assisted chemical vapor deposition of TiO 2 nanocrystals with controllable crystal phases. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Limited mutagenicity of electronic cigarettes in mouse or human cells in vitro.

PubMed

Tommasi, Stella; Bates, Steven E; Behar, Rachel Z; Talbot, Prue; Besaratinia, Ahmad

2017-10-01

Electronic cigarettes (e-cig), which are promoted as safe alternatives to tobacco cigarettes or as aides to smoking cessation, are becoming increasingly popular among adult chronic smokers and adolescents experimenting with tobacco products. Despite the known presence of toxicants and carcinogens in e-cig liquid and vapor, the possible carcinogenic effects of e-cig use in humans are unknown. We have utilized two validated in vitro model systems to investigate whether e-cig vapor induces mutation in mouse or human cells. We have exposed transgenic mouse fibroblasts in vitro to e-cig vapor extracts prepared from three popular brands, and determined the induction of mutagenesis in a reporter gene, the cII transgene. Furthermore, we have treated the pSP189 plasmid with e-cig vapor extract, transfected human fibroblast cells with the e-cig-treated plasmid, and screened for the induced mutations in the supF gene. We observed no statistically significant increases in relative mutant frequency in the cII transgene or supF gene in the e-cig treated mouse or human cells, respectively. Our data indicate that e-cig vapor extracts from the selected brands and at concentrations tested in this study have limited mutagenicity in both mouse and human cells in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

[New tobacco vaporizers: how to react?].

PubMed

Etter, Jean-François

2015-06-10

Cigarette combustion, rather than either tobacco or nicotine, is the cause of a public health disaster. Fortunately, several new technologies that vaporize nicotine or tobacco may make cigarettes obsolete. Some of these new technologies are developed and owned by the tobacco industry, which invests massively for the research and development of these products. Because of its past scientific misconduct, the tobacco industry is ostracized. In the context of a fierce ideological debate on these new products, it is crucial that regulators and the public are provided with evidence-based guidance. Should the scientific production in this field be done with or without the tobacco industry? This thorny issue is discussed in this comment.

Short-term effects of a nicotine-free e-cigarette compared to a traditional cigarette in smokers and non-smokers.

PubMed

Ferrari, Marco; Zanasi, Alessandro; Nardi, Elena; Morselli Labate, Antonio Maria; Ceriana, Piero; Balestrino, Antonella; Pisani, Lara; Corcione, Nadia; Nava, Stefano

2015-10-12

A few studies have assessed the short-term effects of low-dose nicotine e-cigarettes, while data about nicotine-free e-cigarettes (NF e-cigarettes) are scanty. Concerns have been expressed about the use of NF e-cigarettes, because of the high concentrations of propylene glycol and other compounds in the e-cigarette vapor. This laboratory-based study was aimed to compare the effects of ad libitum use of a NF e-cigarette or and a traditional cigarette for 5 min in healthy adult smokers (n = 10) and non-smokers (n = 10). The main outcome measures were pulmonary function tests, fraction of exhaled nitric oxide (FeNO) and fractional concentration of carbon monoxide (FeCO) in exhaled breath. The traditional cigarette induced statistically significant increases in FeCO in both smokers and non-smokers, while no significant changes were observed in FeNO. In non-smokers, the traditional cigarette induced a significant decrease from baseline in FEF75 (81 % ± 35 % vs 70.2 % ± 28.2 %, P = 0.013), while in smokers significant decreases were observed in FEF25 (101.3 % ± 16.4 % vs 93.5 % ± 31.7 %, P = 0.037), FEV1 (102.2 % ± 9.5 % vs 98.3 % ± 10 %, P = 0.037) and PEF (109.5 % ± 14.6 % vs 99.2 % ± 17.5 %, P = 0.009). In contrast, the only statistically significant effects induced by the NF e-cigarette in smokers were reductions in FEV1 (102.2 % ± 9.5 % vs 99.5 ± 7.6 %, P = 0.041) and FEF25 (103.4 % ± 16.4 % vs 94.2 % ± 16.2 %, P =  .014). The present study demonstrated that the specific brand of NF e-cigarette utilized did not induce any majoracute effects. In contrast, several studies have shown that both traditional cigarettes and nicotine-containing e-cigarettes have acute effects on lung function. Our study expands on previous observations on the effects of NF e-cigarettes, but also for the first time describes the changes induced by smoking one traditional cigarette in a group of never smokers. The short-term use of the specific brand of NF e-cigarette assessed

Crystal growth from the vapor phase experiment MA-085

NASA Technical Reports Server (NTRS)

Wiedemeir, H.; Sadeek, H.; Klaessig, F. C.; Norek, M.

1976-01-01

Three vapor transport experiments on multicomponent systems were performed during the Apollo Soyuz mission to determine the effects of microgravity forces on crystal morphology and mass transport rates. The mixed systems used germanium selenide, tellurium, germanium tetraiodide (transport agent), germanium monosulfide, germanium tetrachloride (transport agent), and argon (inert atmosphere). The materials were enclosed in evacuated sealed ampoules of fused silica and were transported in a temperature gradient of the multipurpose electric furnace onboard the Apollo Soyuz spacecraft. Preliminary evaluation of 2 systems shows improved quality of space grown crystals in terms of growth morphology and bulk perfection. This conclusion is based on a direct comparison of space grown and ground based crystals by means of X-ray diffraction, microscopic, and chemical etching techniques. The observation of greater mass transport rates than predicted for a microgravity environment by existing vapor transport models indicates the existence of nongravity caused transport effects in a reactive solid/gas phase system.

Aldehyde Detection in Electronic Cigarette Aerosols

PubMed Central

2017-01-01

Acetaldehyde, acrolein, and formaldehyde are the principal toxic aldehydes present in cigarette smoke and contribute to the risk of cardiovascular disease and noncancerous pulmonary disease. The rapid growth of the use of electronic cigarettes (e-cigarettes) has raised concerns over emissions of these harmful aldehydes. This work determines emissions of these aldehydes in both free and bound (aldehyde–hemiacetal) forms and other carbonyls from the use of e-cigarettes. A novel silicon microreactor with a coating phase of 4-(2-aminooxyethyl)-morpholin-4-ium chloride (AMAH) was used to trap carbonyl compounds in the aerosols of e-cigarettes via oximation reactions. AMAH–aldehyde adducts were measured using gas chromatography–mass spectrometry. 1H nuclear magnetic resonance spectroscopy was used to analyze hemiacetals in the aerosols. These aldehydes were detected in the aerosols of all e-cigarettes. Newer-generation e-cigarette devices generated more aldehydes than the first-generation e-cigarettes because of higher battery power output. Formaldehyde–hemiacetal was detected in the aerosols generated from some e-liquids using the newer e-cigarette devices at a battery power output of 11.7 W and above. The emission of these aldehydes from all e-cigarettes, especially higher levels of aldehydes from the newer-generation e-cigarette devices, indicates the risk of using e-cigarettes. PMID:28393137

Platelet activation, adhesion, inflammation, and aggregation potential are altered in the presence of electronic cigarette extracts of variable nicotine concentrations.

PubMed

Hom, Sarah; Chen, Li; Wang, Tony; Ghebrehiwet, Berhane; Yin, Wei; Rubenstein, David A

2016-11-01

Tobacco smoke extracts prepared from both mainstream and sidestream smoking have been associated with heightened platelet activation, aggregation, adhesion, and inflammation. Conversely, it has been shown that pure nicotine inhibits similar platelet functions. In this work, we 1) evaluated the effects of e-cigarette extracts on platelet activities and 2) elucidated the differences between the nicotine-dependent and non-nicotine dependent (e.g. fine particulate matter or toxic compounds) effects of tobacco and e-cigarette products on platelet activities. To accomplish these goals, platelets from healthy volunteers (n = 50) were exposed to tobacco smoke extracts, e-cigarette vapor extracts, and pure nicotine and changes in platelet activation, adhesion, aggregation, and inflammation were evaluated, using optical aggregation, flow cytometry, and ELISA methods. Interestingly, the exposure of platelets to e-vapor extracts induced a significant up-regulation in the expression of the pro-inflammatory gC1qR and cC1qR and induced a marked increase in the deposition of C3b as compared with traditional tobacco smoke extracts. Similarly, platelet activation, as measured by a prothrombinase based assay, and platelet aggregation were also significantly enhanced after exposure to e-vapor extracts. Finally, platelet adhesion potential toward fibrinogen, von Willebrand factor, and other platelets was also enhanced after exposure to e-cigarette vapor extracts. In the presence of pure nicotine, platelet functions were observed to be inhibited, which further suggests that other constituents of tobacco smoke and electronic vapor can antagonize platelet functions, however, the presence of nicotine in extracts somewhat perpetuated the platelet functional changes in a dose-dependent manner.

Adolescent Males’ Awareness of and Willingness to Try Electronic Cigarettes

PubMed Central

Pepper, Jessica K.; Reiter, Paul L.; McRee, Annie-Laurie; Cameron, Linda D.; Gilkey, Melissa B.; Brewer, Noel T.

2012-01-01

Purpose Electronic cigarettes (e-cigarettes) are a new type of device that delivers vaporized nicotine without the tobacco combustion of regular cigarettes. We sought to understand awareness of and willingness to try e-cigarettes among adolescent males, a group that is at risk for smoking initiation and may use e-cigarettes as a “gateway” to smoking. Methods A national sample of 11–19-year-old males (n =228) completed an online survey in November 2011. We recruited participants through their parents, who were members of a panel of U.S. households constructed using random-digit dialing and addressed-based sampling. Results Only two participants (< 1%) had previously tried e-cigarettes. Among those who had not tried e-cigarettes, most (67%) had heard of them. Awareness was higher among older and non- Hispanic adolescents. Nearly 1 in 5 (18%) participants were willing to try either a plain or flavored e-cigarette, but willingness to try plain versus flavored varieties did not differ. Smokers were more willing to try any e-cigarette than nonsmokers (74% vs. 13%; OR 10.25, 95% CI 2.88, 36.46). Nonsmokers who had more negative beliefs about the typical smoker were less willing to try e-cigarettes (OR .58, 95% CI .43, .79). Conclusions Most adolescent males were aware of e-cigarettes, and a substantial minority were willing to try them. Given that even experimentation with e-cigarettes could lead to nicotine dependence and subsequent use of other tobacco products, regulatory and behavioral interventions are needed to prevent “gateway” use by adolescent nonsmokers. Campaigns promoting negative images of smokers or FDA bans on sales to youth may help deter use. PMID:23332477

Reduction of degradation in vapor phase transported InP/InGaAsP mushroom stripe lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, H.; Burkhardt, E.G.; Pfister, W.

1988-10-03

The rapid degradation rate generally observed in InP/InGaAsP mushroom stripe lasers can be considerably decreased by regrowing the open sidewalls of the active stripe with low-doped InP in a second epitaxial step using the hydride vapor phase transport technique. This technique does not change the fundamental laser parameters like light-current and current-voltage characteristics. Because of this drastic reduction in degradation, the vapor phase epitaxy regrown InP/InGaAsP mushroom laser seems to be an interesting candidate for application in optical communication.

APTS and rGO co-functionalized pyrenated fluorescent nanonets for representative vapor phase nitroaromatic explosive detection

NASA Astrophysics Data System (ADS)

Guo, Linjuan; Zu, Baiyi; Yang, Zheng; Cao, Hongyu; Zheng, Xuefang; Dou, Xincun

2014-01-01

For the first time, flexible PVP/pyrene/APTS/rGO fluorescent nanonets were designed and synthesized via a one-step electrospinning method to detect representative subsaturated nitroaromatic explosive vapor. The functional fluorescent nanonets, which were highly stable in air, showed an 81% quenching efficiency towards TNT vapor (~10 ppb) with an exposure time of 540 s at room temperature. The nice performance of the nanonets was ascribed to the synergistic effects induced by the specific adsorption properties of APTS, the fast charge transfer properties and the effective π-π interaction with pyrene and TNT of rGO. Compared to the analogues of TNT, the PVP/pyrene/APTS/rGO nanonets showed notable selectivity towards TNT and DNT vapors. The explored functionalization method opens up brand new insight into sensitive and selective detection of vapor phase nitroaromatic explosives.For the first time, flexible PVP/pyrene/APTS/rGO fluorescent nanonets were designed and synthesized via a one-step electrospinning method to detect representative subsaturated nitroaromatic explosive vapor. The functional fluorescent nanonets, which were highly stable in air, showed an 81% quenching efficiency towards TNT vapor (~10 ppb) with an exposure time of 540 s at room temperature. The nice performance of the nanonets was ascribed to the synergistic effects induced by the specific adsorption properties of APTS, the fast charge transfer properties and the effective π-π interaction with pyrene and TNT of rGO. Compared to the analogues of TNT, the PVP/pyrene/APTS/rGO nanonets showed notable selectivity towards TNT and DNT vapors. The explored functionalization method opens up brand new insight into sensitive and selective detection of vapor phase nitroaromatic explosives. Electronic supplementary information (ESI) available: Vapor pressure of TNT and its analogues, fluorescence quenching kinetics, fluorescence quenching efficiencies and additional SEM images. See DOI: 10.1039/c3nr04960d

Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations.

PubMed

Peace, Michelle R; Baird, Tyson R; Smith, Nathaniel; Wolf, Carl E; Poklis, Justin L; Poklis, Alphonse

2016-07-01

Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography-tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography-mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Nicotinic receptor involvement in antinociception induced by exposure to cigarette smoke.

PubMed

Simons, Christopher T; Cuellar, Jason M; Moore, Justin A; Pinkerton, Kent E; Uyeminami, Dale; Carstens, Mirela Iodi; Carstens, E

2005-12-02

Direct exposure of rats to tobacco smoke induces antinociception. We presently investigated if this antinociception is mediated via nicotinic and/or mu-opioid receptors. Adult male rats were surgically implanted with Alzet osmotic minipumps that delivered either saline (control), the nicotinic antagonist mecamylamine, or the opiate antagonist naltrexone (3 mg/kg/day i.v. for 21 days). Nocifensive responses were assessed on alternate days using tail-flick reflex latency (TFL) over a 3-week period. During the second week, the rats were exposed to concentrated cigarette smoke in an environmental chamber for 6 h/day for 5 consecutive days; a control group was similarly exposed to filtered cigarette smoke. Rats receiving mecamylamine and naltrexone exhibited a significant weight loss after the first day of infusion. All treatment groups additionally exhibited significant weight loss during exposure to unfiltered or filtered smoke. The saline group exhibited significant antinociception on the first day of smoke exposure with rapid development of tolerance. The mecamylamine and naltrexone groups did not exhibit significant antinociception. Controls exposed to filtered smoke (with approximately 50% lower nicotine concentration) also exhibited significant analgesia on the first exposure day with rapid development of tolerance. Exposure to high levels of cigarette smoke, or to filtered smoke with a lower nicotine concentration in the vapor phase, induces antinociception with rapid development of tolerance. The antinociceptive effect appears to be mediated via nicotinic and mu-opioid receptors.

To Regulate or Not to Regulate? Views on Electronic Cigarette Regulations and Beliefs about the Reasons for and against Regulation.

PubMed

Sanders-Jackson, Ashley; Tan, Andy S L; Bigman, Cabral A; Mello, Susan; Niederdeppe, Jeff

2016-01-01

Policies designed to restrict marketing, access to, and public use of electronic cigarettes (e-cigarettes) are increasingly under debate in various jurisdictions in the US. Little is known about public perceptions of these policies and factors that predict their support or opposition. Using a sample of US adults from Amazon Mechanical Turk in May 2015, this paper identifies beliefs about the benefits and costs of regulating e-cigarettes and identifies which of these beliefs predict support for e-cigarette restricting policies. A higher proportion of respondents agreed with 8 different reasons to regulate e-cigarettes (48.5% to 83.3% agreement) versus 7 reasons not to regulate e-cigarettes (11.5% to 18.9%). The majority of participants agreed with 7 out of 8 reasons for regulation. When all reasons to regulate or not were included in a final multivariable model, beliefs about protecting people from secondhand vapor and protecting youth from trying e-cigarettes significantly predicted stronger support for e-cigarette restricting policies, whereas concern about government intrusion into individual choices was associated with reduced support. This research identifies key beliefs that may underlie public support or opposition to policies designed to regulate the marketing and use of e-cigarettes. Advocates on both sides of the issue may find this research valuable in developing strategic campaigns related to the issue. Specific beliefs of potential benefits and costs of e-cigarette regulation (protecting youth, preventing exposure to secondhand vapor, and government intrusion into individual choices) may be effectively deployed by policy makers or health advocates in communicating with the public.

Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents.

PubMed

Troutt, William D; DiDonato, Matthew D

2017-11-01

Cannabis use has increased in the United States, particularly the use of vaporized cannabis oil, which is often mixed with thinning agents for use in vaporizing devices. E-cigarette research shows that heated thinning agents produce potentially harmful carbonyls; however, similar studies have not been conducted (1) with agents that are commonly used in the cannabis industry and (2) at temperatures that are appropriate for cannabis oil vaporization. The goal of this study was to determine whether thinning agents used in the cannabis industry produce potentially harmful carbonyls when heated to a temperature that is appropriate for cannabis oil vaporization. Four thinning agents (propylene glycol [PG], vegetable glycerin [VG], polyethylene glycol 400 [PEG 400], and medium chain triglycerides [MCT]) were heated to 230°C and the resulting vapors were tested for acetaldehyde, acrolein, and formaldehyde. Each agent was tested three times. Testing was conducted in a smoking laboratory. Carbonyl levels were measured in micrograms per puff block. Analyses showed that PEG 400 produced significantly higher levels of acetaldehyde and formaldehyde than PG, MCT, and VG. Formaldehyde production was also significantly greater in PG compared with MCT and VG. Acrolein production did not differ significantly across the agents. PG and PEG 400 produced high levels of acetaldehyde and formaldehyde when heated to 230°C. Formaldehyde production from PEG 400 isolate was particularly high, with one inhalation accounting for 1.12% of the daily exposure limit, nearly the same exposure as smoking one cigarette. Because PG and PEG 400 are often mixed with cannabis oil, individuals who vaporize cannabis oil products may risk exposure to harmful formaldehyde levels. Although more research is needed, consumers and policy makers should consider these potential health effects before use and when drafting cannabis-related legislation.

Formative research to identify perceptions of e-cigarettes in college students: Implications for future health communication campaigns

PubMed Central

Case, Kathleen; Crook, Brittani; Lazard, Allison; Mackert, Michael

2016-01-01

Objective This formative study examined perceptions of e-cigarettes in college students with the goal of informing future health communication campaigns. Differences between e-cigarette users and nonusers were also examined. Participants: Thirty undergraduate students were recruited from a large southwestern public university (15 users, 15 nonusers). Methods Structured interviews were conducted and transcripts were coded for themes. Results Although users had more favorable attitudes toward e-cigarettes, both users and nonusers believed that e-cigarettes produce water vapor and reported that e-cigarettes were less harmful than conventional cigarettes. Potential health consequences and addiction concerns were the most common perceived threats for both users and nonusers. Both nonusers and users cited social stigma as a perceived disadvantage of e-cigarette use. Conclusions Ultimately, themes with particular relevance to future health communication campaigns included negative perceptions of e-cigarette users and social stigma, as well as harm perceptions and potential health consequences associated with e-cigarette use. PMID:26979833

Formative research to identify perceptions of e-cigarettes in college students: Implications for future health communication campaigns.

PubMed

Case, Kathleen; Crook, Brittani; Lazard, Allison; Mackert, Michael

2016-07-01

This formative study examined perceptions of e-cigarettes in college students with the goal of informing future health communication campaigns. Differences between e-cigarette users and nonusers were also examined. Thirty undergraduate students were recruited from a large southwestern public university (15 users, 15 nonusers). Structured interviews were conducted and transcripts were coded for themes. Although users had more favorable attitudes toward e-cigarettes, both users and nonusers believed that e-cigarettes produce water vapor and reported that e-cigarettes were less harmful than conventional cigarettes. Potential health consequences and addiction concerns were the most common perceived threats for both users and nonusers. Both nonusers and users cited social stigma as a perceived disadvantage of e-cigarette use. Ultimately, themes with particular relevance to future health communication campaigns included negative perceptions of e-cigarette users and social stigma, as well as harm perceptions and potential health consequences associated with e-cigarette use.

Removal of Oxygen from Electronic Materials by Vapor-Phase Processes

NASA Technical Reports Server (NTRS)

Palosz, Witold

1997-01-01

Thermochemical analyses of equilibrium partial pressures over oxides with and without the presence of the respective element condensed phase, and hydrogen, chalcogens, hydrogen chalcogenides, and graphite are presented. Theoretical calculations are supplemented with experimental results on the rate of decomposition and/or sublimation/vaporization of the oxides under dynamic vacuum, and on the rate of reaction with hydrogen, graphite, and chalcogens. Procedures of removal of a number of oxides under different conditions are discussed.

Condensed phase conversion and growth of nanorods and other materials instead of from vapor

DOEpatents

Geohegan, David B.; Seals, Roland D.; Puretzky, Alex A.; Fan, Xudong

2010-10-19

Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed phase matrix material instead of from vapor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

A three-dimensional phase field model for nanowire growth by the vapor-liquid-solid mechanism

NASA Astrophysics Data System (ADS)

Wang, Yanming; Ryu, Seunghwa; McIntyre, Paul C.; Cai, Wei

2014-07-01

We present a three-dimensional multi-phase field model for catalyzed nanowire (NW) growth by the vapor-liquid-solid (VLS) mechanism. The equation of motion contains both a Ginzburg-Landau term for deposition and a diffusion (Cahn-Hilliard) term for interface relaxation without deposition. Direct deposition from vapor to solid, which competes with NW crystal growth through the molten catalyst droplet, is suppressed by assigning a very small kinetic coefficient at the solid-vapor interface. The thermodynamic self-consistency of the model is demonstrated by its ability to reproduce the equilibrium contact angles at the VLS junction. The incorporation of orientation dependent gradient energy leads to faceting of the solid-liquid and solid-vapor interfaces. The model successfully captures the curved shape of the NW base and the Gibbs-Thomson effect on growth velocity.

Graphene oxide bound silica for solid-phase extraction of 14 polycyclic aromatic hydrocarbons in mainstream cigarette smoke.

PubMed

Shi, Rui; Yan, Lihong; Xu, Tongguang; Liu, Dongye; Zhu, Yongfa; Zhou, Jun

2015-01-02

Polycyclic aromatic hydrocarbons (PAHs) were considered as a source of carcinogenicity in mainstream cigarette smoke (MSS). Accurate quantification of these components was necessary for assessing public health risk. In our study, a solid-phase extraction (SPE) method using graphene oxide (GO) bound silica as adsorbent for purification of 14 PAHs in MSS was developed. During SPE process, large matrices interferences of MSS were adsorbed on SPE column. The result of FTIR spectra demonstrated that these matrices interferences were adsorbed on GO mainly through OH and CO groups. The concentrations of PAHs in MSS extract were determined by gas chromatography-mass spectrometry (GC-MS). The limit of detection (LOD) and limit of quantification (LOQ) of the developed method for 14 PAHs ranged from 0.05 to 0.36 ng/cig and 0.17 to 1.19 ng/cig, respectively. The accuracy of the measurement of 14 PAHs was from 73 to 116%. The relative standard deviations of intra- and inter-day analysis were less than 7.8% and 13.9%, respectively. Moreover, the developed method was successfully applied for analysis of real cigarette containing 1R5F reference cigarette and 12 top-selling commercial cigarettes in China. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of Two Commercially Available Cannabidiol Formulations for Use in Electronic Cigarettes.

PubMed

Peace, Michelle R; Butler, Karen E; Wolf, Carl E; Poklis, Justin L; Poklis, Alphonse

2016-01-01

Since 24 states and the District of Columbia have legalized marijuana in some form, suppliers of legal marijuana have developed Cannabis sativa products for use in electronic cigarettes (e-cigarettes). Personal battery powered vaporizers, or e-cigarettes, were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. The liquid formulations used in these devices are comprised of an active ingredient such as nicotine mixed with vegetable glycerin (VG) and/or propylene glycol (PG) and flavorings. A significant active ingredient of C. sativa, cannabidiol (CBD), has been purported to have anti-convulsant, anti-nociceptive, and anti-psychotic properties. These properties have potential medical therapies such as intervention of addictive behaviors, treatments for epilepsy, management of pain for cancer patients, and treatments for schizophrenia. However, CBD extracted from C. sativa remains a DEA Schedule I drug since it has not been approved by the FDA for medical purposes. Two commercially available e-cigarette liquid formulations reported to contain 3.3 mg/mL of CBD as the active ingredient were evaluated. These products are not regulated by the FDA in manufacturing or in labeling of the products and were found to contain 6.5 and 7.6 mg/mL of CBD in VG and PG with a variety of flavoring agents. Presently, while labeled as to content, the quality control of manufacturers and the relative safety of these products is uncertain.

[E-Cigarettes: Assessment of Health Effects and Potential Benefits for Smokers].

PubMed

Schaller, K; Mons, U

2018-06-01

E-cigarettes are electronic devices used to vaporize a flavored liquid resulting in aerosols to be inhaled by the user. The high variety of e-cigarettes and liquids makes it difficult to assess the health effects of e-cigarette use. The ingredients of the liquids - apart from nicotine - are generally recognized as safe for oral and dermal use, however, toxicological data on health effects upon chronic inhalation are missing. Studies have detected several harmful substances in e-cigarette aerosol, including carcinogens, but in lower concentrations than tobacco smoke. Evidence suggests that e-cigarette use entails acute health effects such as inflammatory responses in the lung. In animal and in vitro studies e-cigarette aerosol showed adverse effects like cytotoxicity, increased infiltration of inflammatory cells and pro-inflammatory cytokines, increased oxidative stress and moderate inflammation. Compared to tobacco smoking e-cigarettes are very likely to be less harmful, however, due to scarce data the extent of harm reduction cannot be quantified. Although smokers often use e-cigarettes to quit smoking, currently they are not approved as smoking cessation aids. As e-cigarette aerosol is a new source of air pollution, it is reasonable to assume that it poses an increased health risk to bystanders, in particular to vulnerable persons such as children and people with health conditions. E-cigarettes can have a positive effect on public health, if many smokers completely switch from smoking tobacco to e-cigarettes and, finally, also stop e-cigarette use, and if at the same time adverse consequences (such as increased initiation among youths) remain limited. © Georg Thieme Verlag KG Stuttgart · New York.

Biological responses in rats exposed to mainstream smoke from a heated cigarette compared to a conventional reference cigarette.

PubMed

Fujimoto, Hitoshi; Tsuji, Hiroyuki; Okubo, Chigusa; Fukuda, Ichiro; Nishino, Tomoki; Lee, K Monica; Renne, Roger; Yoshimura, Hiroyuki

2015-03-01

The heated cigarette (HC) generates mainstream smoke by vaporizing the components of the tobacco rod using a carbon heat source at the cigarette tip. Mainstream smoke of HC contains markedly less chemical constituents compared to combusted cigarettes. Mainstream smoke from HC was generated under Health Canada Intense regimen and its biological effects were compared to those of Reference (3R4F) cigarettes, using nose-only 5-week and 13-week inhalation studies. In the 13-week study, SD rats were necropsied following exposure to mainstream smoke from each cigarette at 200, 600 or 1000 µg wet total particulate matter/L for 1 h/day, 7 days/week or following a 13-week recovery period. Histopathological changes in the respiratory tract were significantly lesser in HC groups; e.g. respiratory epithelial hyperplasia in the nasal cavity and accumulation of pigmented macrophages in alveoli. After a 13-week recovery, the lesions were completely or partially regressed, except for accumulation of pigmented macrophages in alveoli, in both HC and 3R4F groups. In the 5-week study, SD rats were necropsied following exposure to mainstream smoke of either cigarette at 600 or 1000 µg/L for 1 h, two times/day (with 30 min interval), 7 days/week or following a 4-week recovery period. Bronchoalveolar lavage fluid (BALF) analysis of neutrophil percentages and enzyme levels like γ-GT, ALP and LDH indicated that pulmonary inflammation was significantly less in HC groups compared to 3R4F groups. In conclusion, HC demonstrated significantly lower biological effects compared to 3R4F, based on the BALF parameters and histopathology.

The e-cigarette psychosocial environment, e-cigarette use, and susceptibility to cigarette smoking

PubMed Central

Barrington-Trimis, Jessica L.; Berhane, Kiros; Unger, Jennifer B.; Cruz, Tess Boley; Urman, Robert; Chou, Chih Ping; Howland, Steve; Wang, Kejia; Pentz, Mary Ann; Gilreath, Tamika D.; Huh, Jimi; Leventhal, Adam M.; Samet, Jonathan M.; McConnell, Rob

2016-01-01

Purpose One concern regarding the recent increase in adolescent e-cigarette use is the possibility that e-cigarettes may be used by those who might not otherwise have used cigarettes, and that dual use, or transition to cigarette use alone, may follow. Methods Questionnaire data were obtained in 2014 from 11th/12th grade students attending schools in 12 communities included in the Southern California Children’s Health Study (CHS). We evaluated the cross-sectional association between e-cigarette use, the psychosocial environment (family and friends’ use and approval of e-cigarettes and cigarettes) and susceptibility to future cigarette use among never cigarette smokers (N=1694), using previously validated measures based on reported absence of a definitive commitment not to smoke. Results Among adolescents who had never used cigarettes, 31.8% of past e-cigarette users and 34.6% of current (past 30 day) e-cigarette users indicated susceptibility to cigarette use, compared to 21.0% of never e-cigarette users. The odds of indicating susceptibility to cigarette use were two times higher for current e-cigarette users compared to never users (OR=1.97; 95%CI: 1.21, 3.22). A social environment favorable to e-cigarettes (friends’ use of and positive attitudes toward use of e-cigarettes) was also associated with greater likelihood of susceptibility to cigarette use, independent of an individual’s e-cigarette use. Conclusions E-cigarette use in adolescence, and a pro-e-cigarette social environment, may put adolescents at risk for future use of cigarettes. E-cigarettes may contribute to subsequent cigarette use via nicotine addiction or social normalization of smoking behaviors. PMID:27161417

Mid-infrared laser-absorption diagnostic for vapor-phase fuel mole fraction and liquid fuel film thickness

NASA Astrophysics Data System (ADS)

Porter, J. M.; Jeffries, J. B.; Hanson, R. K.

2011-02-01

A novel two-wavelength mid-infrared laser-absorption diagnostic has been developed for simultaneous measurements of vapor-phase fuel mole fraction and liquid fuel film thickness. The diagnostic was demonstrated for time-resolved measurements of n-dodecane liquid films in the absence and presence of n-decane vapor at 25°C and 1 atm. Laser wavelengths were selected from FTIR measurements of the C-H stretching band of vapor n-decane and liquid n-dodecane near 3.4 μm (3000 cm-1). n-Dodecane film thicknesses <20 μm were accurately measured in the absence of vapor, and simultaneous measurements of n-dodecane liquid film thickness and n-decane vapor mole fraction (300 ppm) were measured with <10% uncertainty for film thicknesses <10 μm. A potential application of the measurement technique is to provide accurate values of vapor mole fraction in combustion environments where strong absorption by liquid fuel or oil films on windows make conventional direct absorption measurements of the gas problematic.

The E-cigarette Social Environment, E-cigarette Use, and Susceptibility to Cigarette Smoking.

PubMed

Barrington-Trimis, Jessica L; Berhane, Kiros; Unger, Jennifer B; Cruz, Tess Boley; Urman, Robert; Chou, Chih Ping; Howland, Steve; Wang, Kejia; Pentz, Mary Ann; Gilreath, Tamika D; Huh, Jimi; Leventhal, Adam M; Samet, Jonathan M; McConnell, Rob

2016-07-01

One concern regarding the recent increase in adolescent e-cigarette use is the possibility that electronic (e-) cigarettes may be used by those who might not otherwise have used cigarettes, and that dual use, or transition to cigarette use alone, may follow. Questionnaire data were obtained in 2014 from 11th/12th grade students attending schools in 12 communities included in the Southern California Children's Health Study. We evaluated the cross-sectional association between e-cigarette use, the social environment (family and friends' use and approval of e-cigarettes and cigarettes), and susceptibility to future cigarette use among never cigarette smokers (N = 1,694), using previously validated measures based on reported absence of a definitive commitment not to smoke. Among adolescents who had never used cigarettes, 31.8% of past e-cigarette users and 34.6% of current (past 30-day) e-cigarette users indicated susceptibility to cigarette use, compared with 21.0% of never e-cigarette users. The odds of indicating susceptibility to cigarette use were two times higher for current e-cigarette users compared with never users (odds ratio = 1.97; 95% confidence interval: 1.21-3.22). A social environment favorable to e-cigarettes (friends' use of and positive attitudes toward the use of e-cigarettes) was also associated with greater likelihood of susceptibility to cigarette use, independent of an individual's e-cigarette use. E-cigarette use in adolescence, and a pro-e-cigarette social environment, may put adolescents at risk for future use of cigarettes. E-cigarettes may contribute to subsequent cigarette use via nicotine addiction or social normalization of smoking behaviors. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

External fuel vaporization study, phase 2

NASA Technical Reports Server (NTRS)

Szetela, E. J.; Chiappetta, L.

1981-01-01

An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

To Regulate or Not to Regulate? Views on Electronic Cigarette Regulations and Beliefs about the Reasons for and against Regulation

PubMed Central

Sanders-Jackson, Ashley; Tan, Andy S. L.; Bigman, Cabral A.; Mello, Susan; Niederdeppe, Jeff

2016-01-01

Background Policies designed to restrict marketing, access to, and public use of electronic cigarettes (e-cigarettes) are increasingly under debate in various jurisdictions in the US. Little is known about public perceptions of these policies and factors that predict their support or opposition. Methods Using a sample of US adults from Amazon Mechanical Turk in May 2015, this paper identifies beliefs about the benefits and costs of regulating e-cigarettes and identifies which of these beliefs predict support for e-cigarette restricting policies. Results A higher proportion of respondents agreed with 8 different reasons to regulate e-cigarettes (48.5% to 83.3% agreement) versus 7 reasons not to regulate e-cigarettes (11.5% to 18.9%). The majority of participants agreed with 7 out of 8 reasons for regulation. When all reasons to regulate or not were included in a final multivariable model, beliefs about protecting people from secondhand vapor and protecting youth from trying e-cigarettes significantly predicted stronger support for e-cigarette restricting policies, whereas concern about government intrusion into individual choices was associated with reduced support. Discussion This research identifies key beliefs that may underlie public support or opposition to policies designed to regulate the marketing and use of e-cigarettes. Advocates on both sides of the issue may find this research valuable in developing strategic campaigns related to the issue. Implications Specific beliefs of potential benefits and costs of e-cigarette regulation (protecting youth, preventing exposure to secondhand vapor, and government intrusion into individual choices) may be effectively deployed by policy makers or health advocates in communicating with the public. PMID:27517716

Water Sorption and Vapor-Phase Deuterium Exchange Studies on Methemoglobin CC, SC, SS, AS, and AA

PubMed Central

Killion, Philip J.; Cameron, Bruce F.

1972-01-01

Five hemoglobins whose genetic relationship to one another involves one set of alleles, hemoglobins CC, SC, SS, AS, and AA, were studied in the Met form. Two different investigations were conducted at 28°C on these methemoglobins within a McBain gravimetric sorption system: sorption of H2O vapor and vapor-phase deuterium-hydrogen exchange. For each of the five samples there was close agreement between the per cent hydration of polar sites as determined from sorption studies and the maximum per cent of labile hydrogens that were exchanged during the vapor-phase deuterium exchange study. Both studies measured a slight increase in the number of polar sites accessible to H2O or D2O vapor for those samples in which the substituent in the sixth position from the N-terminus of the two β-chains had a positively charged side chain and a slight decrease for those in which the substituent had a negatively charged side chain. The in-exchange of deuterium for hydrogen occurred at a faster observed rate than the out-exchange of hydrogen for deuterium. PMID:5030563

Simplified thermodynamic functions for vapor-liquid phase separation and fountain effect pumps

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Hepler, W. A.; Frederking, T. H. K.

1984-01-01

He-4 fluid handling devices near 2 K require novel components for non-Newtonian fluid transport in He II. Related sizing of devices has to be based on appropriate thermophysical property functions. The present paper presents simplified equilibrium state functions for porous media components which serve as vapor-liquid phase separators and fountain effect pumps.

E-Cigarette Marketing and Communication: How E-Cigarette Companies Market E-Cigarettes and the Public Engages with E-cigarette Information.

PubMed

Collins, Lauren; Glasser, Allison M; Abudayyeh, Haneen; Pearson, Jennifer L; Villanti, Andrea C

2018-01-05

Given the lack of regulation on marketing of electronic cigarettes (e-cigarettes) in the U.S. and the increasing exchange of e-cigarette-related information online, it is critical to understand how e-cigarette companies market e-cigarettes and how the public engages with e-cigarette information. Results are from a systematic review of peer-reviewed literature on e-cigarettes via a PubMed search through June 1, 2017. Search terms included: "e-cigarette*" OR "electronic cigarette" OR "electronic cigarettes" OR "electronic nicotine delivery" OR "vape" OR "vaping." Experimental studies, quasi-experimental studies, observational studies, qualitative studies, and mixed methods studies providing empirical findings on e-cigarette marketing and communication (i.e., non-marketing communication in the public) were included. One hundred twenty-four publications on e-cigarette marketing and communication were identified. They covered topics including e-cigarette advertisement claims/promotions and exposure/receptivity, the effect of e-cigarette advertisements on e-cigarette and cigarette use, public engagement with e-cigarette information, and the public's portrayal of e-cigarettes. Studies show increases in e-cigarette marketing expenditures and online engagement through social media over time, that e-cigarettes are often framed as an alternative to combustible cigarettes, and that e-cigarette advertisement exposure may be associated with e-cigarette trial in adolescents and young adults. Few studies examine the effects of e-cigarette marketing on perceptions and e-cigarette and cigarette use. Evidence suggests that exposure to e-cigarette advertisements affects perceptions and trial of e-cigarettes, but there is no evidence that exposure affects cigarette use. No studies examined how exposure to e-cigarette communication, particularly misleading or inaccurate information, impacts e-cigarette and tobacco use behaviors. The present article provides a comprehensive review of e-cigarette

Differences in vaping topography in relation to adherence to exclusive electronic cigarette use in veterans

PubMed Central

Balestrini, Kira; Holt, Gregory; Mirsaeidi, Mehdi; Calderon-Candelario, Rafael; Whitney, Philip; Salathe, Matthias

2018-01-01

Background Understanding vaping patterns of electronic cigarette (EC) use is important to understand the real-life exposure to EC vapor. Long term information on vaping topography in relation to tobacco cigarette (TC) smoking cessation success has not been explored. Methods Observational non-blinded study where active TC smokers were asked to replace TC with EC over 4 weeks (replacement phase, RP) followed by exclusive EC use for an additional 12 weeks (maintenance phase, MP). TC use and EC compliance was monitored weekly. Subjects were classified as success or failure whether or not they completed the protocol. Vaping information was stored and downloaded directly from the EC device and averaged per calendar day for analysis. Results From 25 subjects that followed the protocol, sixteen succeeded in completing the RP and 8 the MP (32%). No significant differences in baseline characteristics were noted between subjects in the success and failure groups including markers of nicotine addiction, plasma cotinine levels or smoking history. Success subjects showed significantly longer puff duration (seconds per vape) and total overall vapor exposure (number of vapes x average vape duration or vape-seconds) in both study phases. Furthermore, subjects in the success group continued to increase the number of vapes, device voltage and wattage significantly as they transitioned into the MP. After an initial drop, subjects in the success group were able to regain plasma cotinine levels comparable to their TC use while subjects in the failure group could not. Cotinine levels significantly correlated with the average number of daily vapes and vapes-seconds, but not with other vaping parameters. Conclusion The topography of smokers who adhere to exclusive EC use reflects a progressive and dynamic device adaptation over weeks to maintain baseline cotinine levels. The higher inhaled volume over time should be considered when addressing the potential toxic effects of EC and the

Differences in vaping topography in relation to adherence to exclusive electronic cigarette use in veterans.

PubMed

Guerrero-Cignarella, Andrea; Luna Diaz, Landy V; Balestrini, Kira; Holt, Gregory; Mirsaeidi, Mehdi; Calderon-Candelario, Rafael; Whitney, Philip; Salathe, Matthias; Campos, Michael A

2018-01-01

Understanding vaping patterns of electronic cigarette (EC) use is important to understand the real-life exposure to EC vapor. Long term information on vaping topography in relation to tobacco cigarette (TC) smoking cessation success has not been explored. Observational non-blinded study where active TC smokers were asked to replace TC with EC over 4 weeks (replacement phase, RP) followed by exclusive EC use for an additional 12 weeks (maintenance phase, MP). TC use and EC compliance was monitored weekly. Subjects were classified as success or failure whether or not they completed the protocol. Vaping information was stored and downloaded directly from the EC device and averaged per calendar day for analysis. From 25 subjects that followed the protocol, sixteen succeeded in completing the RP and 8 the MP (32%). No significant differences in baseline characteristics were noted between subjects in the success and failure groups including markers of nicotine addiction, plasma cotinine levels or smoking history. Success subjects showed significantly longer puff duration (seconds per vape) and total overall vapor exposure (number of vapes x average vape duration or vape-seconds) in both study phases. Furthermore, subjects in the success group continued to increase the number of vapes, device voltage and wattage significantly as they transitioned into the MP. After an initial drop, subjects in the success group were able to regain plasma cotinine levels comparable to their TC use while subjects in the failure group could not. Cotinine levels significantly correlated with the average number of daily vapes and vapes-seconds, but not with other vaping parameters. The topography of smokers who adhere to exclusive EC use reflects a progressive and dynamic device adaptation over weeks to maintain baseline cotinine levels. The higher inhaled volume over time should be considered when addressing the potential toxic effects of EC and the variable EC adherence when addressing

Influence of phase transition on the instability of a liquid-vapor interface in a gravitational field

NASA Astrophysics Data System (ADS)

Konovalov, V. V.; Lyubimov, D. V.; Lyubimova, T. P.

2017-06-01

This study is concerned with the linear stability of the horizontal interface between thick layers of a viscous heat-conducting liquid and its vapor in a gravitational field subject to phase transition. We consider the case when the hydrostatic base state is consistent with a balanced heat flux at the liquid-vapor interface. The corrections to the growth rate of the most dangerous perturbations and cutoff wave number, characterizing the influence of phase transition on the Rayleigh-Taylor instability, are found to be different from the data in the literature. Most of the previous results were obtained in the framework of a quasiequilibrium approximation, which had been shown to conform to the limit of thin media layers under equality of the interface temperature to a saturation temperature. The main difference from the results obtained with the quasiequilibrium approach is new values of the proportionality coefficients that correlate our corrections with the intensity of weak heating. Moreover, at large values of the heat flux rate, when deviations from the approximate linear law are important, the effect of phase transition is limited and does not exceed the size of the vapor viscosity effect.

The mechanism of vapor phase hydration of calcium oxide: implications for CO2 capture.

PubMed

Kudłacz, Krzysztof; Rodriguez-Navarro, Carlos

2014-10-21

Lime-based sorbents are used for fuel- and flue-gas capture, thereby representing an economic and effective way to reduce CO2 emissions. Their use involves cyclic carbonation/calcination which results in a significant conversion reduction with increasing number of cycles. To reactivate spent CaO, vapor phase hydration is typically performed. However, little is known about the ultimate mechanism of such a hydration process. Here, we show that the vapor phase hydration of CaO formed after calcination of calcite (CaCO3) single crystals is a pseudomorphic, topotactic process, which progresses via an intermediate disordered phase prior to the final formation of oriented Ca(OH)2 nanocrystals. The strong structural control during this solid-state phase transition implies that the microstructural features of the CaO parent phase predetermine the final structural and physicochemical (reactivity and attrition) features of the product hydroxide. The higher molar volume of the product can create an impervious shell around unreacted CaO, thereby limiting the efficiency of the reactivation process. However, in the case of compact, sintered CaO structures, volume expansion cannot be accommodated in the reduced pore volume, and stress generation leads to pervasive cracking. This favors complete hydration but also detrimental attrition. Implications of these results in carbon capture and storage (CCS) are discussed.

E-Cigarettes and Future Cigarette Use.

PubMed

Barrington-Trimis, Jessica L; Urman, Robert; Berhane, Kiros; Unger, Jennifer B; Cruz, Tess Boley; Pentz, Mary Ann; Samet, Jonathan M; Leventhal, Adam M; McConnell, Rob

2016-07-01

There has been little research examining whether e-cigarette use increases the risk of cigarette initiation among adolescents in the transition to adulthood when the sale of cigarettes becomes legal. The Children's Health Study is a prospectively followed cohort in Southern California. Data on e-cigarette use were collected in 11th and 12th grade (mean age = 17.4); follow-up data on tobacco product use were collected an average of 16 months later from never-smoking e-cigarette users at initial evaluation (n = 146) and from a sample of never-smoking, never e-cigarette users (n = 152) frequency matched to e-cigarette users on gender, ethnicity, and grade. Cigarette initiation during follow-up was reported by 40.4% of e-cigarette users (n = 59) and 10.5% of never users (n = 16). E-cigarette users had 6.17 times (95% confidence interval: 3.30-11.6) the odds of initiating cigarettes as never e-cigarette users. Results were robust to adjustment for potential confounders and in analyses restricted to never users of any combustible tobacco product. Associations were stronger in adolescents with no intention of smoking at initial evaluation. E-cigarette users were also more likely to initiate use of any combustible product (odds ratio = 4.98; 95% confidence interval: 2.37-10.4), including hookah, cigars, or pipes. E-cigarette use in never-smoking youth may increase risk of subsequent initiation of cigarettes and other combustible products during the transition to adulthood when the purchase of tobacco products becomes legal. Stronger associations in participants with no intention of smoking suggests that e-cigarette use was not simply a marker for individuals who would have gone on to smoke regardless of e-cigarette use. Copyright © 2016 by the American Academy of Pediatrics.

E-Cigarettes and Future Cigarette Use

PubMed Central

Urman, Robert; Berhane, Kiros; Unger, Jennifer B.; Cruz, Tess Boley; Pentz, Mary Ann; Samet, Jonathan M.; Leventhal, Adam M.; McConnell, Rob

2016-01-01

BACKGROUND: There has been little research examining whether e-cigarette use increases the risk of cigarette initiation among adolescents in the transition to adulthood when the sale of cigarettes becomes legal. METHODS: The Children’s Health Study is a prospectively followed cohort in Southern California. Data on e-cigarette use were collected in 11th and 12th grade (mean age = 17.4); follow-up data on tobacco product use were collected an average of 16 months later from never-smoking e-cigarette users at initial evaluation (n = 146) and from a sample of never-smoking, never e-cigarette users (n = 152) frequency matched to e-cigarette users on gender, ethnicity, and grade. RESULTS: Cigarette initiation during follow-up was reported by 40.4% of e-cigarette users (n = 59) and 10.5% of never users (n = 16). E-cigarette users had 6.17 times (95% confidence interval: 3.30–11.6) the odds of initiating cigarettes as never e-cigarette users. Results were robust to adjustment for potential confounders and in analyses restricted to never users of any combustible tobacco product. Associations were stronger in adolescents with no intention of smoking at initial evaluation. E-cigarette users were also more likely to initiate use of any combustible product (odds ratio = 4.98; 95% confidence interval: 2.37–10.4), including hookah, cigars, or pipes. CONCLUSIONS: E-cigarette use in never-smoking youth may increase risk of subsequent initiation of cigarettes and other combustible products during the transition to adulthood when the purchase of tobacco products becomes legal. Stronger associations in participants with no intention of smoking suggests that e-cigarette use was not simply a marker for individuals who would have gone on to smoke regardless of e-cigarette use. PMID:27296866

Graphical review: The redox dark side of e-cigarettes; exposure to oxidants and public health concerns.

PubMed

Cai, Hua; Wang, Chen

2017-10-01

Since the initial marketing in 2005, the use of e-cigarettes has increased exponentially. Nonetheless, accumulating evidence has demonstrated the ineffectiveness of e-cigarettes in leading to smoking cessation, and decreasing the adverse health impacts of cigarette smoking. The number of adolescents adapted to e-cigarettes has been increasing substantially each year, and this adaptation has promoted openness to tobacco smoking. The present review discusses controversies regarding the smoking cessation effects of e-cigarettes, recent governmental policies and regulations of e-cigarette use, toxic components and vaporization products of e-cigarettes, and the novel molecular mechanisms underlying the adverse health impacts of e-cigarettes leading to oxidative stress in target tissues, and consequent development of cardiopulmonary diseases (i.e. COPD), neurodegenerative disorders (i.e. Alzheimer's' disease), and cancer. Health warning signs on the packaging and professional consultation to avoid adaptation in risk groups might be helpful solutions to control negative impacts of e-cigarettes. It is also recommended to further expand basic and clinical investigations to reveal more detailed oxidative stress mechanisms of e-cigarette induced damages, which would ultimately result in more effective protective strategies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Locomotor Stimulant and Rewarding Effects of Inhaling Methamphetamine, MDPV, and Mephedrone via Electronic Cigarette-Type Technology

PubMed Central

Nguyen, Jacques D; Aarde, Shawn M; Cole, Maury; Vandewater, Sophia A; Grant, Yanabel; Taffe, Michael A

2016-01-01

Although inhaled exposure to drugs is a prevalent route of administration for human substance abusers, preclinical models that incorporate inhaled exposure to psychomotor stimulants are not commonly available. Using a novel method that incorporates electronic cigarette-type technology to facilitate inhalation, male Wistar rats were exposed to vaporized methamphetamine (MA), 3,4-methylenedioxypyrovalerone (MDPV), and mephedrone (4-methylmethcathinone) in propylene glycol vehicle using concentrations ranging from 12.5 to 200 mg/ml. Rats exhibited increases in spontaneous locomotor activity, measured by implanted radiotelemetry, following exposure to methamphetamine (12.5 and 100 mg/ml), MDPV (25, 50, and 100 mg/ml), and mephedrone (200 mg/ml). Locomotor effects were blocked by pretreatment with the dopamine D1-like receptor antagonist SCH23390 (10 μg/kg, intraperitoneal (i.p.)). MA and MDPV vapor inhalation also altered activity on a running wheel in a biphasic manner. An additional group of rats was trained on a discrete trial intracranial self-stimulation (ICSS) procedure interpreted to assess brain reward status. ICSS-trained rats that received vaporized MA, MDPV, or mephedrone exhibited a significant reduction in threshold of ICSS reward compared with vehicle. The effect of vapor inhalation of the stimulants was found comparable to the locomotor and ICSS threshold-reducing effects of i.p. injection of mephedrone (5.0 mg/kg), MA (0.5–1.0 mg/kg), or MDPV (0.5–1.0 mg/kg). These data provide robust validation of e-cigarette-type technology as a model for inhaled delivery of vaporized psychostimulants. Finally, these studies demonstrate the potential for human use of e-cigarettes to facilitate covert use of a range of psychoactive stimulants. Thus, these devices pose health risks beyond their intended application for the delivery of nicotine. PMID:27277119

Adsorptive Water Removal from Dichloromethane and Vapor-Phase Regeneration of a Molecular Sieve 3A Packed Bed

PubMed Central

2017-01-01

The drying of dichloromethane with a molecular sieve 3A packed bed process is modeled and experimentally verified. In the process, the dichloromethane is dried in the liquid phase and the adsorbent is regenerated by water desorption with dried dichloromethane product in the vapor phase. Adsorption equilibrium experiments show that dichloromethane does not compete with water adsorption, because of size exclusion; the pure water vapor isotherm from literature provides an accurate representation of the experiments. The breakthrough curves are adequately described by a mathematical model that includes external mass transfer, pore diffusion, and surface diffusion. During the desorption step, the main heat transfer mechanism is the condensation of the superheated dichloromethane vapor. The regeneration time is shortened significantly by external bed heating. Cyclic steady-state experiments demonstrate the feasibility of this novel, zero-emission drying process. PMID:28539701

"Smoking revolution": a content analysis of electronic cigarette retail websites.

PubMed

Grana, Rachel A; Ling, Pamela M

2014-04-01

Electronic cigarettes (e-cigarettes) have been increasingly available and marketed in the U.S. since 2007. As patterns of product adoption are frequently driven and reinforced by marketing, it is important to understand the marketing claims encountered by consumers. To describe the main advertising claims made on branded e-cigarette retail websites. Websites were retrieved from two major search engines in 2011 using iterative searches with the following terms: electronic cigarette, e-cigarette, e-cig, and personal vaporizer. Fifty-nine websites met inclusion criteria, and 13 marketing claims were coded for main marketing messages in 2012. Ninety-five percent of the websites made explicit or implicit health-related claims, 64% had a smoking cessation-related claim, 22% featured doctors, and 76% claimed that the product does not produce secondhand smoke. Comparisons to cigarettes included claims that e-cigarettes were cleaner (95%) and cheaper (93%). Eighty-eight percent stated that the product could be smoked anywhere and 71% mentioned using the product to circumvent clean air policies. Candy, fruit, and coffee flavors were offered on most sites. Youthful appeals included images or claims of modernity (73%); increased social status (44%); enhanced social activity (32%); romance (31%); and use by celebrities (22%). Health claims and smoking-cessation messages that are unsupported by current scientific evidence are frequently used to sell e-cigarettes. Implied and overt health claims, the presence of doctors on websites, celebrity endorsements, and the use of characterizing flavors should be prohibited. Copyright © 2014 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Preventing kinetic roughening in physical vapor-phase-deposited films.

PubMed

Vasco, E; Polop, C; Sacedón, J L

2008-01-11

The growth kinetics of the mostly used physical vapor-phase deposition techniques -molecular beam epitaxy, sputtering, flash evaporation, and pulsed laser deposition-is investigated by rate equations with the aim of testing their suitability for the preparation of ultraflat ultrathin films. The techniques are studied in regard to the roughness and morphology during early stages of growth. We demonstrate that pulsed laser deposition is the best technique for preparing the flattest films due to two key features [use of (i) a supersaturated pulsed flux of (ii) hyperthermal species] that promote a kinetically limited Ostwald ripening mechanism.

INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: Metal-organic vapor phase epitaxy of (GaAl)As for 0.85-μm laser diodes

NASA Astrophysics Data System (ADS)

Jacobs, K.; Bugge, F.; Butzke, G.; Lehmann, L.; Schimko, R.

1988-11-01

Metal-organic vapor phase epitaxy was used to grow stripe heterolaser diodes that were hitherto fabricated by liquid phase epitaxy. The main relationships between the growth parameters (partial input pressures, temperatures) and the properties of materials (thicknesses, solid-solution compositions, carrier densities) were investigated. The results were in full agreement with the mechanism of growth controlled by a vapor-phase diffusion. The results achieved routinely in the growth of GaAs are reported. It is shown that double heterostructure laser diodes fabricated by metal-organic vapor phase epitaxy compete favorably with those grown so far by liquid phase epitaxy, including their degradation and reliability.

Experimental study of flash boiling spray vaporization through quantitative vapor concentration and liquid temperature measurements

NASA Astrophysics Data System (ADS)

Zhang, Gaoming; Hung, David L. S.; Xu, Min

2014-08-01

Flash boiling sprays of liquid injection under superheated conditions provide the novel solutions of fast vaporization and better air-fuel mixture formation for internal combustion engines. However, the physical mechanisms of flash boiling spray vaporization are more complicated than the droplet surface vaporization due to the unique bubble generation and boiling process inside a superheated bulk liquid, which are not well understood. In this study, the vaporization of flash boiling sprays was investigated experimentally through the quantitative measurements of vapor concentration and liquid temperature. Specifically, the laser-induced exciplex fluorescence technique was applied to distinguish the liquid and vapor distributions. Quantitative vapor concentration was obtained by correlating the intensity of vapor-phase fluorescence with vapor concentration through systematic corrections and calibrations. The intensities of two wavelengths were captured simultaneously from the liquid-phase fluorescence spectra, and their intensity ratios were correlated with liquid temperature. The results show that both liquid and vapor phase of multi-hole sprays collapse toward the centerline of the spray with different mass distributions under the flash boiling conditions. Large amount of vapor aggregates along the centerline of the spray to form a "gas jet" structure, whereas the liquid distributes more uniformly with large vortexes formed in the vicinity of the spray tip. The vaporization process under the flash boiling condition is greatly enhanced due to the intense bubble generation and burst. The liquid temperature measurements show strong temperature variations inside the flash boiling sprays with hot zones present in the "gas jet" structure and vortex region. In addition, high vapor concentration and closed vortex motion seem to have inhibited the heat and mass transfer in these regions. In summary, the vapor concentration and liquid temperature provide detailed information

Mid-infrared laser-absorption diagnostic for vapor-phase measurements in an evaporating n-decane aerosol

NASA Astrophysics Data System (ADS)

Porter, J. M.; Jeffries, J. B.; Hanson, R. K.

2009-09-01

A novel three-wavelength mid-infrared laser-based absorption/extinction diagnostic has been developed for simultaneous measurement of temperature and vapor-phase mole fraction in an evaporating hydrocarbon fuel aerosol (vapor and liquid droplets). The measurement technique was demonstrated for an n-decane aerosol with D 50˜3 μ m in steady and shock-heated flows with a measurement bandwidth of 125 kHz. Laser wavelengths were selected from FTIR measurements of the C-H stretching band of vapor and liquid n-decane near 3.4 μm (3000 cm -1), and from modeled light scattering from droplets. Measurements were made for vapor mole fractions below 2.3 percent with errors less than 10 percent, and simultaneous temperature measurements over the range 300 K< T<900 K were made with errors less than 3 percent. The measurement technique is designed to provide accurate values of temperature and vapor mole fraction in evaporating polydispersed aerosols with small mean diameters ( D 50<10 μ m), where near-infrared laser-based scattering corrections are prone to error.

Substrate-induced phase of a [1]benzothieno[3,2-b]benzothiophene derivative and phase evolution by aging and solvent vapor annealing.

PubMed

Jones, Andrew O F; Geerts, Yves H; Karpinska, Jolanta; Kennedy, Alan R; Resel, Roland; Röthel, Christian; Ruzié, Christian; Werzer, Oliver; Sferrazza, Michele

2015-01-28

Substrate-induced phases (SIPs) are polymorphic phases that are found in thin films of a material and are different from the single crystal or "bulk" structure of a material. In this work, we investigate the presence of a SIP in the family of [1]benzothieno[3,2-b]benzothiophene (BTBT) organic semiconductors and the effect of aging and solvent vapor annealing on the film structure. Through extensive X-ray structural investigations of spin coated films, we find a SIP with a significantly different structure to that found in single crystals of the same material forms; the SIP has a herringbone motif while single crystals display layered π-π stacking. Over time, the structure of the film is found to slowly convert to the single crystal structure. Solvent vapor annealing initiates the same structural evolution process but at a greatly increased rate, and near complete conversion can be achieved in a short period of time. As properties such as charge transport capability are determined by the molecular structure, this work highlights the importance of understanding and controlling the structure of organic semiconductor films and presents a simple method to control the film structure by solvent vapor annealing.

EFFECT OF VAPOR-PHASE BIOREACTOR OPERATION ON BIOMASS ACCUMULATION, DISTRIBUTION, AND ACTIVITY. (R826168)

EPA Science Inventory

Excess biomass accumulation and activity loss in vapor-phase bioreactors (VPBs) can lead to unreliable long-term operation. In this study, temporal and spatial variations in biomass accumulation, distribution and activity in VPBs treating toluene-contaminated air were monitored o...

Rapid determination of six carcinogenic primary aromatic amines in mainstream cigarette smoke by two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry.

PubMed

Bie, Zhenying; Lu, Wei; Zhu, You; Chen, Yusong; Ren, Hubo; Ji, Lishun

2017-01-27

A fully automated, rapid, and reliable method for simultaneous determination of six carcinogenic primary aromatic amines (AAs), including o-toluidine (o-TOL), 2, 6-dimethylaniline (2, 6-DMA), o-anisidine (o-ASD), 1-naphthylamine (1-ANP), 2-naphthylamine (2-ANP), and 4-aminobiphenyl (4-ABP), in mainstream cigarette smoke was established. The proposed method was based on two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry (SPE/LC-MS/MS). The particulate phase of the mainstream cigarette smoke was collected on a Cambridge filter pad and pretreated via ultrasonic extraction with 2% formic acid (FA), while the gas phase was trapped by 2% FA without pretreatment for determination. The two-dimensional online SPE comprised of two cartridges with different absorption characteristics was applied for sample pretreatment. Analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) under multiple reaction monitoring mode. Each sample required about 0.5h for solid phase extraction and analysis. The limit of detections (LODs) for six AAs ranged from 0.04 to 0.58ng/cig and recoveries were within 84.5%-122.9%. The relative standard deviations of intra- and inter-day tests for 3R4F reference cigarette were less than 6% and 7%, respectively, while no more than 7% and 8% separately for a type of Virginia cigarette. The proposed method enabled minimum sample pretreatment, full automation, and high throughput with high selectivity, sensitivity, and accuracy. As a part of the validation procedure, fifteen brands of cigarettes were tested by the designed method. Copyright © 2016 Elsevier B.V. All rights reserved.

Cigarette smoking and electronic cigarette vaping patterns as a function of e-cigarette flavourings

PubMed Central

Litt, Mark D; Duffy, Valerie; Oncken, Cheryl

2017-01-01

Introduction The present study examined the influence of flavouring on the smoking and vaping behaviour of cigarette smokers asked to adopt e-cigarettes for a period of 6 weeks. Methods Participants were 88 current male and female smokers with no intention to stop smoking, but who agreed to substitute e-cigarettes for their current cigarettes. On intake, participants were administered tests of taste and smell for e-cigarettes flavoured with tobacco, menthol, cherry and chocolate, and were given a refillable e-cigarette of their preferred flavour or a control flavour. Participants completed daily logs of cigarette and e-cigarette use and were followed each week. Results Analyses over days indicated that, during the 6-week e-cigarette period, cigarette smoking rates dropped from an average of about 16 to about 7 cigarettes/day. e-Cigarette flavour had a significant effect such that the largest drop in cigarette smoking occurred among those assigned menthol e-cigarettes, and the smallest drop in smoking occurred among those assigned chocolate and cherry flavours. e-Cigarette vaping rates also differed significantly by flavour assigned, with the highest vaping rates for tobacco- and cherry-flavoured e-cigarettes, and the lowest rates for those assigned to chocolate. Conclusions The findings suggest that adoption of e-cigarettes in smokers may influence smoking rates and that e-cigarette flavourings can moderate this effect. e-Cigarette vaping rates are also influenced by flavourings. These findings may have implications for the utility of e-cigarettes as a nicotine replacement device and for the regulation of flavourings in e-cigarettes for harm reduction. PMID:27633766

E-cigarettes: Impact of E-Liquid Components and Device Characteristics on Nicotine Exposure.

PubMed

DeVito, Elise E; Krishnan-Sarin, Suchitra

2018-01-01

Electronic cigarette (e-cigarette) use has increased substantially in recent years. While e-cigarettes have been proposed as a potentially effective smoking cessation tool, dualuse in smokers is common and e-cigarettes are widely used by non-smokers, including youth and young-adult non-smokers. Nicotine, the primary addictive component in cigarettes, is present at varying levels in many e-liquids. E-cigarettes may lead to initiation of nicotine use in adult and youth non-smokers, re-initiation of nicotine dependence in ex-smokers or increased severity of nicotine dependence in dual-users of cigarettes and e-cigarettes. As such, there are important clinical and policy implications to understanding factors impacting nicotine exposure from e-cigarettes. However, the broad and rapidly changing range of e-liquid constituents and e-cigarette hardware which could impact nicotine exposure presents a challenge. Recent changes in regulatory oversight of e-cigarettes underscore the importance of synthesizing current knowledge on common factors which may impact nicotine exposure. This review focuses on factors which may impact nicotine exposure by changing e-cigarette use behavior, puff topography, altering the nicotine yield (amount of nicotine exiting the e-cigarette mouth piece including nicotine exhaled as vapor) or more directly by altering nicotine absorption and bioavailability. Topics reviewed include e-liquid components or characteristics including flavor additives (e.g., menthol), base e-liquid ingredients (propylene glycol, vegetable glycerin), components commonly used to dissolve flavorants (e.g., ethanol), and resulting properties of the e-liquid (e.g., pH), e-cigarette device characteristics (e.g., wattage, temperature, model) and user behavior (e.g., puff topography) which may impact nicotine exposure. E-liquid characteristics and components, e-cigarette hardware and settings, and user behavior can all contribute substantially to nicotine exposure from e-cigarettes

Non-Ballistic Vapor-Driven Ejecta

NASA Technical Reports Server (NTRS)

Wrobel, K. E.; Schultz, P. H.; Heineck, J. T.

2004-01-01

Impact-induced vaporization is a key component of early-time cratering mechanics. Previous experimental [1,2] and computational [e.g., 3] studies focused on the generation and expansion of vapor clouds in an attempt to better understand vaporization in hypervelocity impacts. Presented here is a new experimental approach to the study of impact-induced vaporization. The three-dimensional particle image velocimetry (3D PIV) system captures interactions between expanding vapor phases and fine particulates. Particles ejected early in the cratering process may be entrained in expanding gas phases generated at impact, altering their otherwise ballistic path of flight. 3D PIV allows identifying the presence of such non-ballistic ejecta from very early times in the cratering process.

Exposure to Electronic Cigarettes Impairs Pulmonary Anti-Bacterial and Anti-Viral Defenses in a Mouse Model

PubMed Central

Sussan, Thomas E.; Gajghate, Sachin; Thimmulappa, Rajesh K.; Ma, Jinfang; Kim, Jung-Hyun; Sudini, Kuladeep; Consolini, Nicola; Cormier, Stephania A.; Lomnicki, Slawo; Hasan, Farhana; Pekosz, Andrew; Biswal, Shyam

2015-01-01

Electronic cigarettes (E-cigs) have experienced sharp increases in popularity over the past five years due to many factors, including aggressive marketing, increased restrictions on conventional cigarettes, and a perception that E-cigs are healthy alternatives to cigarettes. Despite this perception, studies on health effects in humans are extremely limited and in vivo animal models have not been generated. Presently, we determined that E-cig vapor contains 7x1011 free radicals per puff. To determine whether E-cig exposure impacts pulmonary responses in mice, we developed an inhalation chamber for E-cig exposure. Mice that were exposed to E-cig vapor contained serum cotinine concentrations that are comparable to human E-cig users. E-cig exposure for 2 weeks produced a significant increase in oxidative stress and moderate macrophage-mediated inflammation. Since, COPD patients are susceptible to bacterial and viral infections, we tested effects of E-cigs on immune response. Mice that were exposed to E-cig vapor showed significantly impaired pulmonary bacterial clearance, compared to air-exposed mice, following an intranasal infection with Streptococcus pneumonia. This defective bacterial clearance was partially due to reduced phagocytosis by alveolar macrophages from E-cig exposed mice. In response to Influenza A virus infection, E-cig exposed mice displayed increased lung viral titers and enhanced virus-induced illness and mortality. In summary, this study reports a murine model of E-cig exposure and demonstrates that E-cig exposure elicits impaired pulmonary anti-microbial defenses. Hence, E-cig exposure as an alternative to cigarette smoking must be rigorously tested in users for their effects on immune response and susceptibility to bacterial and viral infections. PMID:25651083

OM-VPE growth of Mg-doped GaAs. [OrganoMetallic-Vapor Phase Epitaxy

NASA Technical Reports Server (NTRS)

Lewis, C. R.; Dietze, W. T.; Ludowise, M. J.

1982-01-01

The epitaxial growth of Mg-doped GaAs by the organometallic vapor phase epitaxial process (OM-VPE) has been achieved for the first time. The doping is controllable over a wide range of input fluxes of bis (cyclopentadienyl) magnesium, (C5H5)2Mg, the organometallic precursor to Mg.

Higher cigarette prices influence cigarette purchase patterns.

PubMed

Hyland, A; Bauer, J E; Li, Q; Abrams, S M; Higbee, C; Peppone, L; Cummings, K M

2005-04-01

To examine cigarette purchasing patterns of current smokers and to determine the effects of cigarette price on use of cheaper sources, discount/generic cigarettes, and coupons. Higher cigarette prices result in decreased cigarette consumption, but price sensitive smokers may seek lower priced or tax-free cigarette sources, especially if they are readily available. This price avoidance behaviour costs states excise tax money and dampens the health impact of higher cigarette prices. Telephone survey data from 3602 US smokers who were originally in the COMMIT (community intervention trial for smoking cessation) study were analysed to assess cigarette purchase patterns, use of discount/generic cigarettes, and use of coupons. 59% reported engaging in a high price avoidance strategy, including 34% who regularly purchase from a low or untaxed venue, 28% who smoke a discount/generic cigarette brand, and 18% who report using cigarette coupons more frequently that they did five years ago. The report of engaging in a price avoidance strategy was associated with living within 40 miles of a state or Indian reservation with lower cigarette excise taxes, higher average cigarette consumption, white, non-Hispanic race/ethnicity, and female sex. Data from this study indicate that most smokers are price sensitive and seek out measures to purchase less expensive cigarettes, which may decrease future cessation efforts.

Canary in the coal mine-Initial reports of thermal injury secondary to electronic cigarettes.

PubMed

Bauman, Zachary M; Roman, Jordan; Singer, Matthew; Vercruysse, Gary A

2017-05-01

The use of electronic cigarettes has become increasingly popular with claims suggesting healthier alternatives to tobacco cigarettes. However, research regarding the safety of such devices has been limited to an analysis of the inhaled vapor and the short and long-term effects on the body. A lesser recognized risk of electronic cigarette use is that of lithium-ion battery failure causing ignition, leading to severe thermal injury. Such incidents have been reported in the media but with inconsistencies from a lack of focus on the injuries sustained and a cause of ignition. The cases presented here are among the first recognized thermal injuries sustained from electronic cigarette lithium-ion battery failure, the potential rationale for these failures, and a need for increased awareness of the safety hazards of these devices. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Cigarette smoking and electronic cigarette vaping patterns as a function of e-cigarette flavourings.

PubMed

Litt, Mark D; Duffy, Valerie; Oncken, Cheryl

2016-11-01

The present study examined the influence of flavouring on the smoking and vaping behaviour of cigarette smokers asked to adopt e-cigarettes for a period of 6 weeks. Participants were 88 current male and female smokers with no intention to stop smoking, but who agreed to substitute e-cigarettes for their current cigarettes. On intake, participants were administered tests of taste and smell for e-cigarettes flavoured with tobacco, menthol, cherry and chocolate, and were given a refillable e-cigarette of their preferred flavour or a control flavour. Participants completed daily logs of cigarette and e-cigarette use and were followed each week. Analyses over days indicated that, during the 6-week e-cigarette period, cigarette smoking rates dropped from an average of about 16 to about 7 cigarettes/day. e-Cigarette flavour had a significant effect such that the largest drop in cigarette smoking occurred among those assigned menthol e-cigarettes, and the smallest drop in smoking occurred among those assigned chocolate and cherry flavours. e-Cigarette vaping rates also differed significantly by flavour assigned, with the highest vaping rates for tobacco- and cherry-flavoured e-cigarettes, and the lowest rates for those assigned to chocolate. The findings suggest that adoption of e-cigarettes in smokers may influence smoking rates and that e-cigarette flavourings can moderate this effect. e-Cigarette vaping rates are also influenced by flavourings. These findings may have implications for the utility of e-cigarettes as a nicotine replacement device and for the regulation of flavourings in e-cigarettes for harm reduction. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Delivery of Epinephrine in the Vapor Phase for the Treatment of Croup.

PubMed

Leung, Kitty; Newth, Christopher J L; Hotz, Justin C; O'Brien, Kevin C; Fink, James B; Coates, Allan L

2016-04-01

The Vapotherm system delivers high humidity to the airway of patients by using semipermeable tubules where heated liquid water is in contact with air. The humidified air is conducted to the patient via a heated tube. Preliminary clinical observations in infants with croup suggested that epinephrine added to the water supplying the humidity was delivered successfully in the vapor phase. The purpose of this study was to evaluate the efficiency of the delivery of epinephrine in the vapor phase and to develop the feasibility criteria for a clinical pilot study. Thirty milligrams of epinephrine in a 1-L bag of sterile water was used as the humidification source for a Vapotherm 2000i. The output of the heated circuit was condensed and collected into a small Erlenmeyer flask via a metal coil while the whole collection system was submerged in an ice slurry to maintain the outflow temperature from the flask between 0°C and 2°C. The in vitro system was tested at 40°C with flows of 5, 10, and 15 L/min and L-epinephrine concentrations of 15, 30, and 60 mg/L. Each test was duplicated at each of the six conditions. Academic children's hospital research laboratory. None. None. The system recovered more than 90% of the water vapor from the fully saturated air at 40°C. The epinephrine concentration recovery quantified by ultraviolet-visible spectrophotometry was 23.9% (27.5-20.4%) (mean and range) of the initial concentration. At flows of 5, 10, and 15 L/min, the delivery of epinephrine would be 1.8, 3.6, and 4.2 μg/min, respectively, which is in the therapeutic range used for parenteral infusion in young children. The Vapotherm system can be used to deliver epinephrine in pharmacological doses to the respiratory system as a vapor and thus as an alternative to droplets by conventional nebulization.

Synthesis of TiO2 Nanoparticles from Ilmenite Through the Mechanism of Vapor-Phase Reaction Process by Thermal Plasma Technology

NASA Astrophysics Data System (ADS)

Samal, Sneha

2017-11-01

Synthesis of nanoparticles of TiO2 was carried out by non-transferred arc thermal plasma reactor using ilmenite as the precursor material. The powder ilmenite was vaporized at high temperature in plasma flame and converted to a gaseous state of ions in the metastable phase. On cooling, chamber condensation process takes place on recombination of ions for the formation of nanoparticles. The top-to-bottom approach induces the disintegration of complex ilmenite phases into simpler compounds of iron oxide and titanium dioxide phases. The vapor-phase reaction mechanism was carried out in thermal plasma zone for the synthesis of nanoparticles from ilmenite compound in a plasma reactor. The easy separation of iron particles from TiO2 was taken place in the plasma chamber with deposition of light TiO2 particles at the top of the cooling chamber and iron particles at the bottom. The dissociation and combination process of mechanism and synthesis are studied briefly in this article. The product TiO2 nanoparticle shows the purity with a major phase of rutile content. TiO2 nanoparticles produced in vapor-phase reaction process shows more photo-induced capacity.

Feasibility Study of Vapor-Mist Phase Reaction Lubrication Using a Thioether Liquid

NASA Technical Reports Server (NTRS)

Morales, Wilfredo; Handschuh, Robert F.; Krantz, Timothy L.

2007-01-01

A primary technology barrier preventing the operation of gas turbine engines and aircraft gearboxes at higher temperatures is the inability of currently used liquid lubricants to survive at the desired operating conditions over an extended time period. Current state-of-the-art organic liquid lubricants rapidly degrade at temperatures above 300 C; hence, another form of lubrication is necessary. Vapor or mist phase reaction lubrication is a unique, alternative technology for high temperature lubrication. The majority of past studies have employed a liquid phosphate ester that was vaporized or misted, and delivered to bearings or gears where the phosphate ester reacted with the metal surfaces generating a solid lubricious film. This method resulted in acceptable operating temperatures suggesting some good lubrication properties, but the continuous reaction between the phosphate ester and the iron surfaces led to wear rates unacceptable for gas turbine engine or aircraft gearbox applications. In this study, an alternative non-phosphate liquid was used to mist phase lubricate a spur gearbox rig operating at 10,000 rpm under highly loaded conditions. After 21 million shaft revolutions of operation the gears exhibited only minor wear.

What Online Communities Can Tell Us About Electronic Cigarettes and Hookah Use: A Study Using Text Mining and Visualization Techniques.

PubMed

Chen, Annie T; Zhu, Shu-Hong; Conway, Mike

2015-09-29

The rise in popularity of electronic cigarettes (e-cigarettes) and hookah over recent years has been accompanied by some confusion and uncertainty regarding the development of an appropriate regulatory response towards these emerging products. Mining online discussion content can lead to insights into people's experiences, which can in turn further our knowledge of how to address potential health implications. In this work, we take a novel approach to understanding the use and appeal of these emerging products by applying text mining techniques to compare consumer experiences across discussion forums. This study examined content from the websites Vapor Talk, Hookah Forum, and Reddit to understand people's experiences with different tobacco products. Our investigation involves three parts. First, we identified contextual factors that inform our understanding of tobacco use behaviors, such as setting, time, social relationships, and sensory experience, and compared the forums to identify the ones where content on these factors is most common. Second, we compared how the tobacco use experience differs with combustible cigarettes and e-cigarettes. Third, we investigated differences between e-cigarette and hookah use. In the first part of our study, we employed a lexicon-based extraction approach to estimate prevalence of contextual factors, and then we generated a heat map based on these estimates to compare the forums. In the second and third parts of the study, we employed a text mining technique called topic modeling to identify important topics and then developed a visualization, Topic Bars, to compare topic coverage across forums. In the first part of the study, we identified two forums, Vapor Talk Health & Safety and the Stopsmoking subreddit, where discussion concerning contextual factors was particularly common. The second part showed that the discussion in Vapor Talk Health & Safety focused on symptoms and comparisons of combustible cigarettes and e-cigarettes

What Online Communities Can Tell Us About Electronic Cigarettes and Hookah Use: A Study Using Text Mining and Visualization Techniques

PubMed Central

Zhu, Shu-Hong; Conway, Mike

2015-01-01

Background The rise in popularity of electronic cigarettes (e-cigarettes) and hookah over recent years has been accompanied by some confusion and uncertainty regarding the development of an appropriate regulatory response towards these emerging products. Mining online discussion content can lead to insights into people’s experiences, which can in turn further our knowledge of how to address potential health implications. In this work, we take a novel approach to understanding the use and appeal of these emerging products by applying text mining techniques to compare consumer experiences across discussion forums. Objective This study examined content from the websites Vapor Talk, Hookah Forum, and Reddit to understand people’s experiences with different tobacco products. Our investigation involves three parts. First, we identified contextual factors that inform our understanding of tobacco use behaviors, such as setting, time, social relationships, and sensory experience, and compared the forums to identify the ones where content on these factors is most common. Second, we compared how the tobacco use experience differs with combustible cigarettes and e-cigarettes. Third, we investigated differences between e-cigarette and hookah use. Methods In the first part of our study, we employed a lexicon-based extraction approach to estimate prevalence of contextual factors, and then we generated a heat map based on these estimates to compare the forums. In the second and third parts of the study, we employed a text mining technique called topic modeling to identify important topics and then developed a visualization, Topic Bars, to compare topic coverage across forums. Results In the first part of the study, we identified two forums, Vapor Talk Health & Safety and the Stopsmoking subreddit, where discussion concerning contextual factors was particularly common. The second part showed that the discussion in Vapor Talk Health & Safety focused on symptoms and comparisons

Melting and Vaporization of the 1223 Phase in the System (Tl-Pb-Ba-Sr-Ca-Cu-O)

PubMed Central

Cook, L. P.; Wong-Ng, W.; Paranthaman, P.

1996-01-01

The melting and vaporization of the 1223 [(Tl,Pb):(Ba,Sr):Ca:Cu] oxide phase in the system (Tl-Pb-Ba-Sr-Ca-Cu-O) have been investigated using a combination of dynamic methods (differential thermal analysis, thermogravimetry, effusion) and post-quenching characterization techniques (powder x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectrometry). Vaporization rates, thermal events, and melt compositions were followed as a function of thallia loss from a 1223 stoichiometry. Melting and vaporization equilibria of the 1223 phase are complex, with as many as seven phases participating simultaneously. At a total pressure of 0.1 MPa the 1223 phase was found to melt completely at (980 ± 5) °C in oxygen, at a thallia partial pressure (pTl2O) of (4.6 ± 0.5) kPa, where the quoted uncertainties are standard uncertainties, i.e., 1 estimated standard deviation. The melting reaction involves five other solids and a liquid, nominally as follows: 1223→1212+(Ca,Sr)2CuO3+(Sr,Ca)CuO2+BaPbO3+(Ca,Sr)O+Liquid Stoichiometries of the participating phases have been determined from microchemical analysis, and substantial elemental substitution on the 1212 and 1223 crystallographic sites is indicated. The 1223 phase occurs in equilibrium with liquids from its melting point down to at least 935 °C. The composition of the lowest melting liquid detected for the bulk compositions of this study has been measured using microchemical analysis. Applications to the processing of superconducting wires and tapes are discussed. PMID:27805086

Conductive Textiles via Vapor-Phase Polymerization of 3,4-Ethylenedioxythiophene.

PubMed

Ala, Okan; Hu, Bin; Li, Dapeng; Yang, Chen-Lu; Calvert, Paul; Fan, Qinguo

2017-08-30

We fabricated electrically conductive textiles via vapor-phase polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) layers on cotton, cotton/poly(ethylene terephthalate) (PET), cotton/Lycra, and PET fabrics. We then measured the electrical resistivity values of such PEDOT-coated textiles and analyzed the effect of water treatment on the electrical resistivity. Additionally, we tested the change in the electrical resistance of the conductive textiles under cyclic stretching and relaxation. Last, we characterized the uniformity and morphology of the conductive layer formed on the fabrics using scanning electron microscopy and electron-dispersive X-ray spectroscopy.

CRYOCHEM, Thermodynamic Model for Cryogenic Chemical Systems: Solid-Vapor and Solid-Liquid-Vapor Phase Equilibria Toward Applications on Titan and Pluto

NASA Astrophysics Data System (ADS)

Tan, S. P.; Kargel, J. S.; Adidharma, H.; Marion, G. M.

2014-12-01

Until in-situ measurements can be made regularly on extraterrestrial bodies, thermodynamic models are the only tools to investigate the properties and behavior of chemical systems on those bodies. The resulting findings are often critical in describing physicochemical processes in the atmosphere, surface, and subsurface in planetary geochemistry and climate studies. The extremely cold conditions on Triton, Pluto and other Kuiper Belt Objects, and Titan introduce huge non-ideality that prevents conventional models from performing adequately. At such conditions, atmospheres as a whole—not components individually—are subject to phase equilibria with their equilibrium solid phases or liquid phases or both. A molecular-based thermodynamic model for cryogenic chemical systems, referred to as CRYOCHEM, the development of which is still in progress, was shown to reproduce the vertical composition profile of Titan's atmospheric methane measured by the Huygens probe (Tan et al., Icarus 2013, 222, 53). Recently, the model was also used to describe Titan's global circulation where the calculated composition of liquid in Ligeia Mare is consistent with the bathymetry and microwave absorption analysis of T91 Cassini fly-by data (Tan et al., 2014, submitted). Its capability to deal with equilibria involving solid phases has also been demonstrated (Tan et al., Fluid Phase Equilib. 2013, 360, 320). With all those previous works done, our attention is now shifting to the lower temperatures in Titan's tropopause and on Pluto's surface, where much technical development remains for CRYOCHEM to assure adequate performance at low temperatures. In these conditions, solid-vapor equilibrium (SVE) is the dominant phase behavior that determines the composition of the atmosphere and the existing ices. Another potential application is for the subsurface phase equilibrium, which also involves liquid, thus three-phase equilibrium: solid-liquid-vapor (SLV). This presentation will discuss the

Mainstream Smoke Levels of Volatile Organic Compounds in 50 U.S. Domestic Cigarette Brands Smoked With the ISO and Canadian Intense Protocols.

PubMed

Pazo, Daniel Y; Moliere, Fallon; Sampson, Maureen M; Reese, Christopher M; Agnew-Heard, Kimberly A; Walters, Matthew J; Holman, Matthew R; Blount, Benjamin C; Watson, Clifford H; Chambers, David M

2016-09-01

A significant portion of the increased risk of cancer and respiratory disease from exposure to cigarette smoke is attributed to volatile organic compounds (VOCs). In this study, 21 VOCs were quantified in mainstream cigarette smoke from 50U.S. domestic brand varieties that included high market share brands and 2 Kentucky research cigarettes (3R4F and 1R5F). Mainstream smoke was generated under ISO 3308 and Canadian Intense (CI) smoking protocols with linear smoking machines with a gas sampling bag collection followed by solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) analysis. For both protocols, mainstream smoke VOC amounts among the different brand varieties were strongly correlated between the majority of the analytes. Overall, Pearson correlation (r) ranged from 0.68 to 0.99 for ISO and 0.36 to 0.95 for CI. However, monoaromatic compounds were found to increase disproportionately compared to unsaturated, nitro, and carbonyl compounds under the CI smoking protocol where filter ventilation is blocked. Overall, machine generated "vapor phase" amounts (µg/cigarette) are primarily attributed to smoking protocol (e.g., blocking of vent holes, puff volume, and puff duration) and filter ventilation. A possible cause for the disproportionate increase in monoaromatic compounds could be increased pyrolysis under low oxygen conditions associated with the CI protocol. This is the most comprehensive assessment of volatile organic compounds (VOCs) in cigarette smoke to date, encompassing 21 toxic VOCs, 50 different cigarette brand varieties, and 2 different machine smoking protocols (ISO and CI). For most analytes relative proportions remain consistent among U.S. cigarette brand varieties regardless of smoking protocol, however the CI smoking protocol did cause up to a factor of 6 increase in the proportion of monoaromatic compounds. This study serves as a basis to assess VOC exposure as cigarette smoke is a principle source of overall

APTS and rGO co-functionalized pyrenated fluorescent nanonets for representative vapor phase nitroaromatic explosive detection.

PubMed

Guo, Linjuan; Zu, Baiyi; Yang, Zheng; Cao, Hongyu; Zheng, Xuefang; Dou, Xincun

2014-01-01

For the first time, flexible PVP/pyrene/APTS/rGO fluorescent nanonets were designed and synthesized via a one-step electrospinning method to detect representative subsaturated nitroaromatic explosive vapor. The functional fluorescent nanonets, which were highly stable in air, showed an 81% quenching efficiency towards TNT vapor (∼10 ppb) with an exposure time of 540 s at room temperature. The nice performance of the nanonets was ascribed to the synergistic effects induced by the specific adsorption properties of APTS, the fast charge transfer properties and the effective π-π interaction with pyrene and TNT of rGO. Compared to the analogues of TNT, the PVP/pyrene/APTS/rGO nanonets showed notable selectivity towards TNT and DNT vapors. The explored functionalization method opens up brand new insight into sensitive and selective detection of vapor phase nitroaromatic explosives.

Monitoring of vapor phase polycyclic aromatic hydrocarbons

DOEpatents

Vo-Dinh, Tuan; Hajaligol, Mohammad R.

2004-06-01

An apparatus for monitoring vapor phase polycyclic aromatic hydrocarbons in a high-temperature environment has an excitation source producing electromagnetic radiation, an optical path having an optical probe optically communicating the electromagnetic radiation received at a proximal end to a distal end, a spectrometer or polychromator, a detector, and a positioner coupled to the first optical path. The positioner can slidably move the distal end of the optical probe to maintain the distal end position with respect to an area of a material undergoing combustion. The emitted wavelength can be directed to a detector in a single optical probe 180.degree. backscattered configuration, in a dual optical probe 180.degree. backscattered configuration or in a dual optical probe 90.degree. side scattered configuration. The apparatus can be used to monitor an emitted wavelength of energy from a polycyclic aromatic hydrocarbon as it fluoresces in a high temperature environment.

The intractable cigarette 'filter problem'.

PubMed

Harris, Bradford

2011-05-01

When lung cancer fears emerged in the 1950s, cigarette companies initiated a shift in cigarette design from unfiltered to filtered cigarettes. Both the ineffectiveness of cigarette filters and the tobacco industry's misleading marketing of the benefits of filtered cigarettes have been well documented. However, during the 1950s and 1960s, American cigarette companies spent millions of dollars to solve what the industry identified as the 'filter problem'. These extensive filter research and development efforts suggest a phase of genuine optimism among cigarette designers that cigarette filters could be engineered to mitigate the health hazards of smoking. This paper explores the early history of cigarette filter research and development in order to elucidate why and when seemingly sincere filter engineering efforts devolved into manipulations in cigarette design to sustain cigarette marketing and mitigate consumers' concerns about the health consequences of smoking. Relevant word and phrase searches were conducted in the Legacy Tobacco Documents Library online database, Google Patents, and media and medical databases including ProQuest, JSTOR, Medline and PubMed. 13 tobacco industry documents were identified that track prominent developments involved in what the industry referred to as the 'filter problem'. These reveal a period of intense focus on the 'filter problem' that persisted from the mid-1950s to the mid-1960s, featuring collaborations between cigarette producers and large American chemical and textile companies to develop effective filters. In addition, the documents reveal how cigarette filter researchers' growing scientific knowledge of smoke chemistry led to increasing recognition that filters were unlikely to offer significant health protection. One of the primary concerns of cigarette producers was to design cigarette filters that could be economically incorporated into the massive scale of cigarette production. The synthetic plastic cellulose acetate

Effects of chronic inhalation of electronic cigarettes containing nicotine on glial glutamate transporters and α-7 nicotinic acetylcholine receptor in female CD-1 mice.

PubMed

Alasmari, Fawaz; Crotty Alexander, Laura E; Nelson, Jessica A; Schiefer, Isaac T; Breen, Ellen; Drummond, Christopher A; Sari, Youssef

2017-07-03

Alteration in glutamate neurotransmission has been found to mediate the development of drug dependence, including nicotine. We and others, through using western blotting, have reported that exposure to drugs of abuse reduced the expression of glutamate transporter-1 (GLT-1) as well as cystine/glutamate antiporter (xCT), which consequently increased extracellular glutamate concentrations in the mesocorticolimbic area. However, our previous studies did not reveal any changes in glutamate/aspartate transporter (GLAST) following exposure to drugs of abuse. In the present study, for the first time, we investigated the effect of chronic exposure to electronic (e)-cigarette vapor containing nicotine, for one hour daily for six months, on GLT-1, xCT, and GLAST expression in frontal cortex (FC), striatum (STR), and hippocampus (HIP) in outbred female CD1 mice. In this study, we also investigated the expression of alpha-7 nicotinic acetylcholine receptor (α-7 nAChR), a major pre-synaptic nicotinic receptor in the glutamatergic neurons, which regulates glutamate release. We found that inhalation of e-cigarette vapor for six months increased α-7 nAChR expression in both FC and STR, but not in the HIP. In addition, chronic e-cigarette exposure reduced GLT-1 expression only in STR. Moreover, e-cigarette vapor inhalation induced downregulation of xCT in both the STR and HIP. We did not find any significant changes in GLAST expression in any brain region. Finally, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques, we detected high concentrations of nicotine and cotinine, a major metabolite of nicotine, in the FC tissues of e-cigarette exposed mice. These data provide novel evidence about the effects of chronic nicotine inhalation on the expression of key glial glutamate transporters as well as α-7 nAChR. Our work may suggest that nicotine exposure via chronic inhalation of e-cigarette vapor may be mediated in part by alterations in the glutamatergic

Nicotine and Cotinine Exposure from Electronic Cigarettes: A Population Approach

PubMed Central

de Mendizábal, Nieves Vélez; Jones, David R.; Jahn, Andy; Bies, Robert R.; Brown, Joshua W.

2015-01-01

Background and Objectives Electronic cigarettes (e-cigarettes) are a recent technology that has gained rapid acceptance. Still, little is known about them in terms of safety and effectiveness. A basic question is how effectively they deliver nicotine, however the literature is surprisingly unclear on this point. Here, a population pharmacokinetic (PK) model was developed for nicotine and its major metabolite cotinine with the aim to provide a reliable framework for the simulation of nicotine and cotinine concentrations over time, based solely on inhalation airflow recordings and individual covariates (i.e. weight and breath carbon monoxide CO levels). Methods This study included 10 adults self-identified as heavy smokers (at least one pack per day). Plasma nicotine and cotinine concentrations were measured at regular 10-minute intervals for 90 minutes while human subjects inhaled nicotine vapor from a modified e-cigarette. Airflow measurements were recorded every 200 milliseconds throughout the session. A population PK model for nicotine and cotinine was developed based on previously published PK parameters and the airflow recordings. All the analyses were performed with the nonlinear mixed-effect modelling software NONMEM 7.2. Results The results show that e-cigarettes deliver nicotine effectively, although the pharmacokinetic profiles are lower than those achieved with regular cigarettes. Our PK model effectively predicts plasma nicotine and cotinine concentrations from the inhalation volume, and initial breath CO. Conclusion E-cigarettes are effective at delivering nicotine. This new PK model of e-cigarette usage might be used for pharmacodynamic analysis where the PK profiles are not available. PMID:25503588

“Smoking Revolution” A Content Analysis of Electronic Cigarette Retail Websites

PubMed Central

Grana, Rachel A.; Ling, Pamela M.

2014-01-01

Background Electronic cigarettes (e-cigarettes) have been increasingly available and marketed in the U.S. since 2007. As patterns of product adoption are frequently driven and reinforced by marketing, it is important to understand the marketing claims encountered by consumers. Purpose To describe the main advertising claims made on branded e-cigarette retail websites. Methods Websites were retrieved from two major search engines in 2011 using iterative searches with the following terms: electronic cigarette, e-cigarette, e-cig, and personal vaporizer. Fifty-nine websites met inclusion criteria, and 13 marketing claims were coded for main marketing messages in 2012. Results Ninety-five percent of the websites made explicit or implicit health-related claims, 64% had a smoking cessation-related claim, 22% featured doctors, and 76% claimed that the product does not produce secondhand smoke. Comparisons to cigarettes included claims that e-cigarettes were cleaner (95%) and cheaper (93%). Eighty-eight percent stated that the product could be smoked anywhere and 71% mentioned using the product to circumvent clean air policies. Candy, fruit, and coffee flavors were offered on most sites. Youthful appeals included images or claims of modernity (73%), increased social status (44%), enhanced social activity (32%), romance (31%), and use by celebrities (22%). Conclusions Health claims and smoking cessation messages that are unsupported by current scientific evidence are frequently used to sell e-cigarettes. Implied and overt health claims, the presence of doctors on websites, celebrity endorsements, and the use of characterizing flavors should be prohibited. PMID:24650842

Lung deposition analyses of inhaled toxic aerosols in conventional and less harmful cigarette smoke: a review.

PubMed

Kleinstreuer, Clement; Feng, Yu

2013-09-23

Inhaled toxic aerosols of conventional cigarette smoke may impact not only the health of smokers, but also those exposed to second-stream smoke, especially children. Thus, less harmful cigarettes (LHCs), also called potential reduced exposure products (PREPs), or modified risk tobacco products (MRTP) have been designed by tobacco manufacturers to focus on the reduction of the concentration of carcinogenic components and toxicants in tobacco. However, some studies have pointed out that the new cigarette products may be actually more harmful than the conventional ones due to variations in puffing or post-puffing behavior, different physical and chemical characteristics of inhaled toxic aerosols, and longer exposure conditions. In order to understand the toxicological impact of tobacco smoke, it is essential for scientists, engineers and manufacturers to develop experiments, clinical investigations, and predictive numerical models for tracking the intake and deposition of toxicants of both LHCs and conventional cigarettes. Furthermore, to link inhaled toxicants to lung and other diseases, it is necessary to determine the physical mechanisms and parameters that have significant impacts on droplet/vapor transport and deposition. Complex mechanisms include droplet coagulation, hygroscopic growth, condensation and evaporation, vapor formation and changes in composition. Of interest are also different puffing behavior, smoke inlet conditions, subject geometries, and mass transfer of deposited material into systemic regions. This review article is intended to serve as an overview of contributions mainly published between 2009 and 2013, focusing on the potential health risks of toxicants in cigarette smoke, progress made in different approaches of impact analyses for inhaled toxic aerosols, as well as challenges and future directions.

Assessment of the Vapor Phase Catalytic Ammonia Removal (VPCAR) Technology at the MSFC ECLS Test Facility

NASA Technical Reports Server (NTRS)

Tomes, Kristin; Long, David; Carter, Layne; Flynn, Michael

2007-01-01

The Vapor Phase Catalytic Ammonia. Removal (VPCAR) technology has been previously discussed as a viable option for. the Exploration Water Recovery System. This technology integrates a phase change process with catalytic oxidation in the vapor phase to produce potable water from exploration mission wastewaters. A developmental prototype VPCAR was designed, built and tested under funding provided by a National Research. Announcement (NRA) project. The core technology, a Wiped Film Rotating Device (WFRD) was provided by Water Reuse Technologies under the NRA, whereas Hamilton Sundstrand Space Systems International performed the hardware integration and acceptance test. of the system. Personnel at the-Ames Research Center performed initial systems test of the VPCAR using ersatz solutions. To assess the viability of this hardware for Exploration. Life Support (ELS) applications, the hardware has been modified and tested at the MSFC ECLS Test facility. This paper summarizes the hardware modifications and test results and provides an assessment of this technology for the ELS application.

Use of column V alkyls in organometallic vapor phase epitaxy (OMVPE)

NASA Technical Reports Server (NTRS)

Ludowise, M. J.; Cooper, C. B., III

1982-01-01

The use of the column V-trialkyls trimethylarsenic (TMAs) and trimethylantimony (TMSb) for the organometallic vapor phase epitaxy (OM-VPE) of III-V compound semiconductors is reviewed. A general discussion of the interaction chemistry of common Group III and Group V reactants is presented. The practical application of TMSb and TMAs for OM-VPE is demonstrated using the growth of GaSb, GaAs(1-y)Sb(y), Al(x)Ga(1-x)Sb, and Ga(1-x)In(x)As as examples.

Direct calculation of liquid-vapor phase equilibria from transition matrix Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Errington, Jeffrey R.

2003-06-01

An approach for directly determining the liquid-vapor phase equilibrium of a model system at any temperature along the coexistence line is described. The method relies on transition matrix Monte Carlo ideas developed by Fitzgerald, Picard, and Silver [Europhys. Lett. 46, 282 (1999)]. During a Monte Carlo simulation attempted transitions between states along the Markov chain are monitored as opposed to tracking the number of times the chain visits a given state as is done in conventional simulations. Data collection is highly efficient and very precise results are obtained. The method is implemented in both the grand canonical and isothermal-isobaric ensemble. The main result from a simulation conducted at a given temperature is a density probability distribution for a range of densities that includes both liquid and vapor states. Vapor pressures and coexisting densities are calculated in a straightforward manner from the probability distribution. The approach is demonstrated with the Lennard-Jones fluid. Coexistence properties are directly calculated at temperatures spanning from the triple point to the critical point.

Psychosocial Factors Associated With Adolescent Electronic Cigarette and Cigarette Use

PubMed Central

Berhane, Kiros; Unger, Jennifer B.; Cruz, Tess Boley; Huh, Jimi; Leventhal, Adam M.; Urman, Robert; Wang, Kejia; Howland, Steve; Gilreath, Tamika D.; Chou, Chih-Ping; Pentz, Mary Ann; McConnell, Rob

2015-01-01

BACKGROUND: Use of electronic cigarettes (e-cigarettes) among adolescents has increased since their introduction into the US market in 2007. Little is known about the role of e-cigarette psychosocial factors on risk of e-cigarette or cigarette use in adolescence. METHODS: Information on e-cigarette and cigarette psychosocial factors (use and attitudes about use in the home and among friends) was collected from 11th- and 12th-grade participants in the Southern California Children’s Health Study during the spring of 2014. RESULTS: Of 2084 participants, 499 (24.0%) had used an e-cigarette, including 200 (9.6%) current users (past 30 days); 390 participants (18.7%) had smoked a combustible cigarette, and 119 (5.7%) were current cigarette smokers. Cigarette and e-cigarette use were correlated. Nevertheless, 40.5% (n = 81) of current e-cigarette users had never smoked a cigarette. Psychosocial factors (home use of each product, friends’ use of and positive attitudes toward e-cigarettes and cigarettes) and participant perception of the harm of e-cigarettes were strongly positively associated both with e-cigarette and cigarette use. Most youth who reported e-cigarette use had friends who used e-cigarettes, and almost half of current users reported that they did not believe there were health risks associated with e-cigarette use. CONCLUSIONS: Longitudinal studies of adolescents are needed to determine whether the strong association of e-cigarette psychosocial factors with both e-cigarette and cigarette use will lead to increased cigarette use or dual use of cigarettes and e-cigarettes, or whether e-cigarettes will serve as a gateway to cigarette use. PMID:26216326

Electronic cigarettes: patterns of use, health effects, use in smoking cessation and regulatory issues.

PubMed

Rahman, Muhammad Aziz; Hann, Nicholas; Wilson, Andrew; Worrall-Carter, Linda

2014-01-01

Electronic cigarettes (e-cigarettes) are battery-powered devices that vaporize a liquid solution to deliver a dose of inhaled nicotine to the user. There is ongoing debate regarding their regulation. This comprehensive narrative review aimed to discuss key issues including usage patterns, health effects, efficacy in smoking cessation and regulatory concerns with a view to informing future regulation and research agendas. PubMed, Scopus and Web of Science databases were searched using the terms (electronic cigarettes OR e-cigarettes) for articles in English, relevant to humans and published during January 2009-January 2014. The literature search revealed 37 relevant articles. Findings suggest that e-cigarettes are mostly used by middle-aged current smokers, particularly males, to help them for quitting or for recreation. E-cigarettes contain very low levels of multiple toxic substances such as formaldehyde and acrolein, but these levels are many times lower than those found in cigarettes. They were found to have effectiveness in aiding smoking cessation to a limited degree. Debate continues regarding regulating their use for cessation versus heavy restrictions to control recreational use on the basis that it perpetuates nicotine addiction. The cytotoxicity and long term health effects of e-cigarettes are unknown. Nevertheless the e-cigarette market continues to expand, largely driven by middle-aged smokers who claim to be using e-cigarettes in an attempt to reduce or quit smoking. E-cigarettes may have some potential as smoking cessation aids and, in the researchers' view, should therefore be subject to further research and regulation similar to other nicotine replacement therapies.

A systematic review of health effects of electronic cigarettes.

PubMed

Pisinger, Charlotta; Døssing, Martin

2014-12-01

To provide a systematic review of the existing literature on health consequences of vaporing of electronic cigarettes (ECs). Search in: PubMed, EMBASE and CINAHL. Original publications describing a health-related topic, published before 14 August 2014. PRISMA recommendations were followed. We identified 1101 studies; 271 relevant after screening; 94 eligible. We included 76 studies investigating content of fluid/vapor of ECs, reports on adverse events and human and animal experimental studies. Serious methodological problems were identified. In 34% of the articles the authors had a conflict of interest. Studies found fine/ultrafine particles, harmful metals, carcinogenic tobacco-specific nitrosamines, volatile organic compounds, carcinogenic carbonyls (some in high but most in low/trace concentrations), cytotoxicity and changed gene expression. Of special concern are compounds not found in conventional cigarettes, e.g. propylene glycol. Experimental studies found increased airway resistance after short-term exposure. Reports on short-term adverse events were often flawed by selection bias. Due to many methodological problems, severe conflicts of interest, the relatively few and often small studies, the inconsistencies and contradictions in results, and the lack of long-term follow-up no firm conclusions can be drawn on the safety of ECs. However, they can hardly be considered harmless. Copyright © 2014. Published by Elsevier Inc.

A Novel Classification System for Injuries After Electronic Cigarette Explosions.

PubMed

Patterson, Scott B; Beckett, Allison R; Lintner, Alicia; Leahey, Carly; Greer, Ashley; Brevard, Sidney B; Simmons, Jon D; Kahn, Steven A

Electronic cigarettes (e-cigarettes) contain lithium batteries that have been known to explode and/or cause fires that have resulted in burn injury. The purpose of this article is to present a case study, review injuries caused by e-cigarettes, and present a novel classification system from the newly emerging patterns of burns. A case study was presented and online media reports for e-cigarette burns were queried with search terms "e-cigarette burns" and "electronic cigarette burns." The reports and injury patterns were tabulated. Analysis was then performed to create a novel classification system based on the distinct injury patterns seen in the study. Two patients were seen at our regional burn center after e-cigarette burns. One had an injury to his thigh and penis that required operative intervention after ignition of this device in his pocket. The second had a facial burn and corneal abrasions when the device exploded while he was inhaling vapor. The Internet search and case studies resulted in 26 cases for evaluation. The burn patterns were divided in direct injury from the device igniting and indirect injury when the device caused a house or car fire. A numerical classification was created: direct injury: type 1 (hand injury) 7 cases, type 2 (face injury) 8 cases, type 3 (waist/groin injury) 11 cases, and type 5a (inhalation injury from using device) 2 cases; indirect injury: type 4 (house fire injury) 7 cases and type 5b (inhalation injury from fire started by the device) 4 cases. Multiple e-cigarette injuries are occurring in the United States and distinct patterns of burns are emerging. The classification system developed in this article will aid in further study and future regulation of these dangerous devices.

A Kinetic Model for GaAs Growth by Hydride Vapor Phase Epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulte, Kevin L.; Simon, John; Jain, Nikhil

2016-11-21

Precise control of the growth of III-V materials by hydride vapor phase epitaxy (HVPE) is complicated by the fact that the growth rate depends on the concentrations of nearly all inputs to the reactor and also the reaction temperature. This behavior is in contrast to metalorganic vapor phase epitaxy (MOVPE), which in common practice operates in a mass transport limited regime where growth rate and alloy composition are controlled almost exclusively by flow of the Group III precursor. In HVPE, the growth rate and alloy compositions are very sensitive to temperature and reactant concentrations, which are strong functions of themore » reactor geometry. HVPE growth, particularly the growth of large area materials and devices, will benefit from the development of a growth model that can eventually be coupled with a computational fluid dynamics (CFD) model of a specific reactor geometry. In this work, we develop a growth rate law using a Langmuir-Hinshelwood (L-H) analysis, fitting unknown parameters to growth rate data from the literature that captures the relevant kinetic and thermodynamic phenomena of the HVPE process. We compare the L-H rate law to growth rate data from our custom HVPE reactor, and develop quantitative insight into reactor performance, demonstrating the utility of the growth model.« less

Determination of Selected Chemical Levels in Room Air and on Surfaces after the Use of Cartridge- and Tank-Based E-Vapor Products or Conventional Cigarettes.

PubMed

Liu, Jianmin; Liang, Qiwei; Oldham, Michael J; Rostami, Ali A; Wagner, Karl A; Gillman, I Gene; Patel, Piyush; Savioz, Rebecca; Sarkar, Mohamadi

2017-08-28

There is an ongoing debate regarding the potential of secondhand exposure of non-users to various chemicals from use of e-vapor products (EVPs). Room air levels of 34 chemicals (nicotine, propylene glycol (PG), glycerol, 15 carbonyl chemicals, 12 volatile organic chemicals (VOCs), and four selected trace elements) were measured where EVPs and cigarettes were used by n = 37 healthy adult tobacco users in an exposure chamber. The products used were MarkTen ® 2.5% Classic (Group I), a Prototype GreenSmoke ® 2.4% (Group II), Ego-T ® Tank with subjects' own e-liquids (Group III) and subjects' own conventional cigarettes (Group IV). Products were used under controlled conditions and 4-h ad libitum use. Background (without subjects) and baseline levels (with subjects) were measured. Cumulative 4-h. levels of nicotine, PG and glycerol measured were several-fold below the time-weighted average limits used in workplace exposure evaluation. Most the other chemicals (>75%) were at or below the limit of quantification during EVP use. Significant levels of chemicals (17 out of 34) were observed in Group IV. Overall, our results indicate that under the study conditions with the products tested, cumulative room air levels of the selected chemicals measured over 4-h were relatively small and were several-fold below the current occupational regulatory and consensus limits.

An Experimental Visualization and Image Analysis of Electrohydrodynamically Induced Vapor-Phase Silicon Oil Flow under DC Corona Discharge

NASA Astrophysics Data System (ADS)

Ohyama, Ryu-Ichiro; Fukumoto, Masaru

A DC corona discharge induced electrohydrodynamic (EHD) flow phenomenon for a multi-phase fluid containing a vapor-phase dielectric liquid in the fresh air was investigated. The experimental electrode system was a simple arrangement of needle-plate electrodes for the corona discharges and high-resistivity silicon oil was used as the vapor-phase liquid enclosure. The qualitative observation of EHD flow patterns was conducted by an optical processing on computer tomography and the time-series of discharge current pulse generations at corona discharge electrode were measured simultaneously. These experimental results were analyzed in relationship between the EHD flow motions and the current pulse generations in synchronization. The current pulses and the EHD flow motions from the corona discharge electrode presented a continuous mode similar to the ionic wind in the fresh air and an intermittent mode. In the intermittent mode, the observed EHD flow motion was synchronized with the separated discharge pulse generations. From these experimental results, it was expected that the existence of silicon oil vapor trapped charges gave an occasion to the intermittent generations of the discharge pulses and the secondary EHD flow.

Expectancies for Cigarettes, E-Cigarettes, and Nicotine Replacement Therapies Among E-Cigarette Users (aka Vapers)

PubMed Central

Marquinez, Nicole S.; Correa, John B.; Meltzer, Lauren R.; Unrod, Marina; Sutton, Steven K.; Simmons, Vani N.; Brandon, Thomas H.

2015-01-01

Introduction: Use of e-cigarettes has been increasing exponentially, with the primary motivation reported as smoking cessation. To understand why smokers choose e-cigarettes as an alternative to cigarettes, as well as to US Food and Drug Administration (FDA)–approved nicotine replacement therapies (NRT), we compared outcome expectancies (beliefs about the results of drug use) for the three nicotine delivery systems among vapers, i.e., e-cigarette users, who were former smokers. Methods: Vapers (N = 1,434) completed an online survey assessing 14 expectancy domains as well as perceived cost and convenience. We focused on comparisons between e-cigarettes and cigarettes to determine the attraction of e-cigarettes as a smoking alternative and between e-cigarettes and NRT to determine perceived advantages of e-cigarettes over FDA-approved pharmacotherapy. Results: Participants believed that e-cigarettes, in comparison to conventional cigarettes, had fewer health risks; caused less craving, withdrawal, addiction, and negative physical feelings; tasted better; and were more satisfying. In contrast, conventional cigarettes were perceived as better than e-cigarettes for reducing negative affect, controlling weight, providing stimulation, and reducing stress. E-cigarettes, compared to NRT, were perceived to be less risky, cost less, cause fewer negative physical feelings, taste better, provide more satisfaction, and be better at reducing craving, negative affect, and stress. Moderator analyses indicated history with ad libitum forms of NRT was associated with less positive NRT expectancies. Conclusions: The degree to which expectancies for e-cigarettes differed from expectancies for either tobacco cigarettes or NRT offers insight into the motivation of e-cigarette users and provides guidance for public health and clinical interventions to encourage smoking-related behavior change. PMID:25168035

E-cigarettes and weight loss - product design innovation insights from industry patents.

PubMed

Singh, Harkirat; Kennedy, Ryan David; Lagasse, Lisa; Czaplicki, Lauren M; Cohen, Joanna E

2017-05-19

There is emerging evidence that e-cigarettes are being used by some to mitigate weight gain after quitting smoking, and being used to help control weight. This study sought to identify and describe patents related to innovations for e-cigarette devices associated and weight loss. Relevant patents were identified using Google Patents with the core search terms: "electronic cigarette" OR "e-cigarette" OR "vaporizer" OR "vapourizer" AND "nicotine" AND "weight loss" OR "weight control" OR "obesity" OR "hunger". Patents were reviewed to identify and classify the innovation related to weight loss or weight control. Our search identified 23 unique patents that were filed between 2004 and 2015. Patent applications were sponsored by individual inventors (n=7), tobacco companies (n=5), e-cigarette companies (n=8), pharmaceutical companies (n=2) and a cannabis company (n=1). More than half the patents (n=12) were filed in the US; other countries included China, Germany, South Korea and South Africa. Strategies included using e-cigarette devices to deliver constituents to users that support weight loss through altered metabolism, reduced nutrient absorption, suppressed appetite, or supported healthy behavior change. In most cases (n=18), the innovations detailed in the patents were intended to be used with an e-cigarette device that delivered nicotine to the user. Companies from around the world, and from a range of industries are developing and patenting technologies related to e-cigarettes and weight loss. E-cigarettes may be presented to cigarette users as a possible solution to support smoking cessation and address the fear of weight gain. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Hospitalized Smokers’ Expectancies for Electronic Cigarettes versus Tobacco Cigarettes

PubMed Central

Hendricks, Peter S.; Cases, Mallory G.; Thorne, Christopher B.; Cheong, JeeWon; Harrington, Kathleen F.; Kohler, Connie L.; Bailey, William C.

2016-01-01

Introduction To compare hospitalized smokers’ expectancies for electronic cigarettes (e-cigarettes) against their expectancies for tobacco cigarettes and evaluate relationships between e-cigarette expectancies and intention to use e-cigarettes. Methods Analysis of baseline data from a one-year longitudinal observational study. The setting was a tertiary care academic center hospital in the Southeastern U.S. Participants were 958 hospitalized tobacco cigarette smokers. A questionnaire of e-cigarette expectancies based on the Brief Smoking Consequences Questionnaire-Adult (BSCQ-A) was developed and administered along with the original, tobacco-specific, BSCQ-A. Intention to use e-cigarettes was assessed with a single 10-point Likert scale item. Results Participants reported significantly weaker expectancies for e-cigarettes relative to tobacco cigarettes on all 10 BSCQ-A scales. Participants held sizably weaker expectancies for the health risks of e-cigarettes (p < .001, Cohen's d = −2.07) as well as the ability of e-cigarettes to relieve negative affect (p < .001, Cohen's d = −1.01), satisfy the desire for nicotine (p < .001, Cohen's d = −.83), and taste pleasant (p < .001, Cohen's d = −.73). Among the strongest predictors of intention to use e-cigarettes were greater expectancies that e-cigarettes taste pleasant (p < .001, adjusted β = .34), relieve negative affect (p < .001, adjusted β = .32), and satisfy the desire for nicotine (p < .001, adjusted β = .31). Conclusions Hospitalizedtobacco smokers expect fewer negative and positive outcomes from e-cigarettes versus tobacco cigarettes. This suggests that e-cigarettes might be viable though imperfect substitutes for tobacco cigarettes. PMID:25452052

One of several 'toys' for smoking: young adult experiences with electronic cigarettes in New York City.

PubMed

McDonald, Emily Anne; Ling, Pamela M

2015-11-01

This qualitative research explores the use of electronic cigarettes and other similar 'vapor' delivery devices among young adults in New York City. We employed 17 focus groups followed by 12 semistructured interviews to understand the beliefs, opinions and practices related to the use of electronic cigarettes among young adult smokers (N=87). Participants were mainly daily (52%) and non-daily (41%) smokers. While experimentation with electronic cigarette devices was frequently reported, participants related an overall lack of information about the devices and what they did know often reflected messages in e-cigarette marketing campaigns. Participants also used their own bodily sensations as a way to gauge potential risks and benefits of the products. Finally, young adults, steeped in a culture of personal technologies, perceived e-cigarettes as one more 'toy' among other technologies integrated into their everyday lives. E-cigarettes were also frequently used with other tobacco products, including conventional cigarettes. Our research indicates that public health campaigns may be needed to counter current industry marketing and inform the public that electronic cigarettes are currently unregulated, understudied and contain toxicants and carcinogens. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Expectancies for cigarettes, e-cigarettes, and nicotine replacement therapies among e-cigarette users (aka vapers).

PubMed

Harrell, Paul T; Marquinez, Nicole S; Correa, John B; Meltzer, Lauren R; Unrod, Marina; Sutton, Steven K; Simmons, Vani N; Brandon, Thomas H

2015-02-01

Use of e-cigarettes has been increasing exponentially, with the primary motivation reported as smoking cessation. To understand why smokers choose e-cigarettes as an alternative to cigarettes, as well as to US Food and Drug Administration (FDA)--approved nicotine replacement therapies (NRT), we compared outcome expectancies (beliefs about the results of drug use) for the three nicotine delivery systems among vapers, i.e., e-cigarette users, who were former smokers. Vapers (N = 1,434) completed an online survey assessing 14 expectancy domains as well as perceived cost and convenience. We focused on comparisons between e-cigarettes and cigarettes to determine the attraction of e-cigarettes as a smoking alternative and between e-cigarettes and NRT to determine perceived advantages of e-cigarettes over FDA-approved pharmacotherapy. Participants believed that e-cigarettes, in comparison to conventional cigarettes, had fewer health risks; caused less craving, withdrawal, addiction, and negative physical feelings; tasted better; and were more satisfying. In contrast, conventional cigarettes were perceived as better than e-cigarettes for reducing negative affect, controlling weight, providing stimulation, and reducing stress. E-cigarettes, compared to NRT, were perceived to be less risky, cost less, cause fewer negative physical feelings, taste better, provide more satisfaction, and be better at reducing craving, negative affect, and stress. Moderator analyses indicated history with ad libitum forms of NRT was associated with less positive NRT expectancies. The degree to which expectancies for e-cigarettes differed from expectancies for either tobacco cigarettes or NRT offers insight into the motivation of e-cigarette users and provides guidance for public health and clinical interventions to encourage smoking-related behavior change. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved

The pathophysiology of cigarette smoking and cardiovascular disease: an update.

PubMed

Ambrose, John A; Barua, Rajat S

2004-05-19

Cigarette smoking (CS) continues to be a major health hazard, and it contributes significantly to cardiovascular morbidity and mortality. Cigarette smoking impacts all phases of atherosclerosis from endothelial dysfunction to acute clinical events, the latter being largely thrombotic. Both active and passive (environmental) cigarette smoke exposure predispose to cardiovascular events. Whether there is a distinct direct dose-dependent correlation between cigarette smoke exposure and risk is debatable, as some recent experimental clinical studies have shown a non-linear relation to cigarette smoke exposure. The exact toxic components of cigarette smoke and the mechanisms involved in CS-related cardiovascular dysfunction are largely unknown, but CS increases inflammation, thrombosis, and oxidation of low-density lipoprotein cholesterol. Recent experimental and clinical data support the hypothesis that cigarette smoke exposure increases oxidative stress as a potential mechanism for initiating cardiovascular dysfunction.

New mechanism for autocatalytic decomposition of H2CO3 in the vapor phase.

PubMed

Ghoshal, Sourav; Hazra, Montu K

2014-04-03

In this article, we present high level ab initio calculations investigating the energetics of a new autocatalytic decomposition mechanism for carbonic acid (H2CO3) in the vapor phase. The calculation have been performed at the MP2 level of theory in conjunction with aug-cc-pVDZ, aug-cc-pVTZ, and 6-311++G(3df,3pd) basis sets as well as at the CCSD(T)/aug-cc-pVTZ level. The present study suggests that this new decomposition mechanism is effectively a near-barrierless process at room temperature and makes vapor phase of H2CO3 unstable even in the absence of water molecules. Our calculation at the MP2/aug-cc-pVTZ level predicts that the effective barrier, defined as the difference between the zero-point vibrational energy (ZPE) corrected energy of the transition state and the total energy of the isolated starting reactants in terms of bimolecular encounters, is nearly zero for the autocatalytic decomposition mechanism. The results at the CCSD(T)/aug-cc-pVTZ level of calculations suggest that the effective barrier, as defined above, is sensitive to some extent to the levels of calculations used, nevertheless, we find that the effective barrier height predicted at the CCSD(T)/aug-cc-pVTZ level is very small or in other words the autocatalytic decomposition mechanism presented in this work is a near-barrierless process as mentioned above. Thus, we suggest that this new autocatalytic decomposition mechanism has to be considered as the primary mechanism for the decomposition of carbonic acid, especially at its source, where the vapor phase concentration of H2CO3 molecules reaches its highest levels.

The intractable cigarette ‘filter problem’

PubMed Central

2011-01-01

Background When lung cancer fears emerged in the 1950s, cigarette companies initiated a shift in cigarette design from unfiltered to filtered cigarettes. Both the ineffectiveness of cigarette filters and the tobacco industry's misleading marketing of the benefits of filtered cigarettes have been well documented. However, during the 1950s and 1960s, American cigarette companies spent millions of dollars to solve what the industry identified as the ‘filter problem’. These extensive filter research and development efforts suggest a phase of genuine optimism among cigarette designers that cigarette filters could be engineered to mitigate the health hazards of smoking. Objective This paper explores the early history of cigarette filter research and development in order to elucidate why and when seemingly sincere filter engineering efforts devolved into manipulations in cigarette design to sustain cigarette marketing and mitigate consumers' concerns about the health consequences of smoking. Methods Relevant word and phrase searches were conducted in the Legacy Tobacco Documents Library online database, Google Patents, and media and medical databases including ProQuest, JSTOR, Medline and PubMed. Results 13 tobacco industry documents were identified that track prominent developments involved in what the industry referred to as the ‘filter problem’. These reveal a period of intense focus on the ‘filter problem’ that persisted from the mid-1950s to the mid-1960s, featuring collaborations between cigarette producers and large American chemical and textile companies to develop effective filters. In addition, the documents reveal how cigarette filter researchers' growing scientific knowledge of smoke chemistry led to increasing recognition that filters were unlikely to offer significant health protection. One of the primary concerns of cigarette producers was to design cigarette filters that could be economically incorporated into the massive scale of cigarette

Metalorganic vapor phase epitaxy of AlN on sapphire with low etch pit density

NASA Astrophysics Data System (ADS)

Koleske, D. D.; Figiel, J. J.; Alliman, D. L.; Gunning, B. P.; Kempisty, J. M.; Creighton, J. R.; Mishima, A.; Ikenaga, K.

2017-06-01

Using metalorganic vapor phase epitaxy, methods were developed to achieve AlN films on sapphire with low etch pit density (EPD). Key to this achievement was using the same AlN growth recipe and only varying the pre-growth conditioning of the quartz-ware. After AlN growth, the quartz-ware was removed from the growth chamber and either exposed to room air or moved into the N2 purged glove box and exposed to H2O vapor. After the quartz-ware was exposed to room air or H2O, the AlN film growth was found to be more reproducible, resulting in films with (0002) and (10-12) x-ray diffraction (XRD) rocking curve linewidths of 200 and 500 arc sec, respectively, and EPDs < 100 cm-2. The EPD was found to correlate with (0002) linewidths, suggesting that the etch pits are associated with open core screw dislocations similar to GaN films. Once reproducible AlN conditions were established using the H2O pre-treatment, it was found that even small doses of trimethylaluminum (TMAl)/NH3 on the quartz-ware surfaces generated AlN films with higher EPDs. The presence of these residual TMAl/NH3-derived coatings in metalorganic vapor phase epitaxy (MOVPE) systems and their impact on the sapphire surface during heating might explain why reproducible growth of AlN on sapphire is difficult.

Urinary cotinine levels of electronic cigarette (e-cigarette) users.

PubMed

Göney, Gülşen; Çok, İsmet; Tamer, Uğur; Burgaz, Sema; Şengezer, Tijen

2016-07-01

The popularity of electronic cigarettes (e-cigarettes) is rapidly increasing in many countries. These devices are designed to imitate regular cigarettes, delivering nicotine via inhalation without combusting tobacco but currently, there is a lack of scientific evidence on the presence or absence of nicotine exposure. Such research relies on evidence from e-cigarette users urine samples. In this study, we aimed to determine the levels and compare the amount of nicotine to which e-cigarette users, cigarette smokers and passive smokers are exposed. Therefore, urine samples were collected from e-cigarette users, cigarette smokers, passive smokers, and healthy nonsmokers. The urinary cotinine levels of the subjects were determined using gas chromatography-mass spectrometry. The mean (±SD) urinary cotinine levels were determined as 1755 ± 1848 ng/g creatinine for 32 e-cigarette users, 1720 ± 1335 ng/g creatinine for 33 cigarette smokers and 81.42 ± 97.90 ng/g creatinine for 33 passive smokers. A significant difference has been found between cotinine levels of e-cigarette users and passive smokers (p < 0.05). There were no statistically significant differences between e-cigarette users and cigarette smokers (p > 0.05). This is a seminal study to demonstrate the e-cigarette users are exposed to nicotine as much as cigarette smokers.

Vapor-phase fabrication of β-iron oxide nanopyramids for lithium-ion battery anodes.

PubMed

Carraro, Giorgio; Barreca, Davide; Cruz-Yusta, Manuel; Gasparotto, Alberto; Maccato, Chiara; Morales, Julián; Sada, Cinzia; Sánchez, Luis

2012-12-07

The other polymorph: A vapor-phase route for the fabrication of β-Fe(2)O(3) nanomaterials on Ti substrates at 400-500 °C is reported. For the first time, the β polymorph is tested as anode for lithium batteries, exhibiting promising performances in terms of Li storage and rate capability. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lung Deposition Analyses of Inhaled Toxic Aerosols in Conventional and Less Harmful Cigarette Smoke: A Review

PubMed Central

Kleinstreuer, Clement; Feng, Yu

2013-01-01

Inhaled toxic aerosols of conventional cigarette smoke may impact not only the health of smokers, but also those exposed to second-stream smoke, especially children. Thus, less harmful cigarettes (LHCs), also called potential reduced exposure products (PREPs), or modified risk tobacco products (MRTP) have been designed by tobacco manufacturers to focus on the reduction of the concentration of carcinogenic components and toxicants in tobacco. However, some studies have pointed out that the new cigarette products may be actually more harmful than the conventional ones due to variations in puffing or post-puffing behavior, different physical and chemical characteristics of inhaled toxic aerosols, and longer exposure conditions. In order to understand the toxicological impact of tobacco smoke, it is essential for scientists, engineers and manufacturers to develop experiments, clinical investigations, and predictive numerical models for tracking the intake and deposition of toxicants of both LHCs and conventional cigarettes. Furthermore, to link inhaled toxicants to lung and other diseases, it is necessary to determine the physical mechanisms and parameters that have significant impacts on droplet/vapor transport and deposition. Complex mechanisms include droplet coagulation, hygroscopic growth, condensation and evaporation, vapor formation and changes in composition. Of interest are also different puffing behavior, smoke inlet conditions, subject geometries, and mass transfer of deposited material into systemic regions. This review article is intended to serve as an overview of contributions mainly published between 2009 and 2013, focusing on the potential health risks of toxicants in cigarette smoke, progress made in different approaches of impact analyses for inhaled toxic aerosols, as well as challenges and future directions. PMID:24065038

E-cigarettes and National Adolescent Cigarette Use: 2004-2014.

PubMed

Dutra, Lauren M; Glantz, Stanton A

2017-02-01

E-cigarette use is rapidly increasing among adolescents in the United States, with some suggesting that e-cigarettes are the cause of declining youth cigarette smoking. We hypothesized that the decline in youth smoking changed after e-cigarettes arrived on the US market in 2007. Data were collected by using cross-sectional, nationally representative school-based samples of sixth- through 12th-graders from 2004-2014 National Youth Tobacco Surveys (samples ranged from 16 614 in 2013 to 25 324 in 2004). Analyses were conducted by using interrupted time series of ever (≥1 puff) and current (last 30 days) cigarette smoking. Logistic regression was used to identify psychosocial risk factors associated with cigarette smoking in the 2004-2009 samples; this model was then applied to estimate the probability of cigarette smoking among cigarette smokers and e-cigarette users in the 2011-2014 samples. Youth cigarette smoking decreased linearly between 2004 and 2014 (P = .009 for ever smoking and P = .05 for current smoking), with no significant change in this trend after 2009 (P = .57 and .23). Based on the psychosocial model of smoking, including demographic characteristics, willingness to wear clothing with a tobacco logo, living with a smoker, likelihood of smoking in the next year, likelihood of smoking cigarettes from a friend, and use of tobacco products other than cigarettes or e-cigarettes, the model categorized <25% of current e-cigarette-only users (between 11.0% in 2012 and 23.1% in 2013) as current smokers. The introduction of e-cigarettes was not associated with a change in the linear decline in cigarette smoking among youth. E-cigarette-only users would be unlikely to have initiated tobacco product use with cigarettes. Copyright © 2017 by the American Academy of Pediatrics.

Sintering behavior of ultrafine silicon carbide powders obtained by vapor phase reaction

NASA Technical Reports Server (NTRS)

Okabe, Y.; Miyachi, K.; Hojo, J.; Kato, A.

1984-01-01

The sintering behavior of ultrafine SiC powder with average particle size of about 0.01-0.06 microns produced by a vapor phase reaction of the Me4Si-H2 system was studied at the temperature range of 1400-2050 deg. It was found that the homogeneous dispersion of C on SiC particles is important to remove the surface oxide layer effectively. B and C and inhibitive effect on SiC grain growth.

Ultrahigh-yield growth of GaN via halogen-free vapor-phase epitaxy

NASA Astrophysics Data System (ADS)

Nakamura, Daisuke; Kimura, Taishi

2018-06-01

The material yield of Ga during GaN growth via halogen-free vapor-phase epitaxy (HF-VPE) was systematically investigated and found to be much higher than that obtained using conventional hydride VPE. This is attributed to the much lower process pressure and shorter seed-to-source distance, owing to the inherent chemical reactions and corresponding reactor design used for HF-VPE growth. Ultrahigh-yield GaN growth was demonstrated on a 4-in.-diameter sapphire seed substrate.

Columnar jointing in vapor-phase-altered, non-welded Cerro Galán Ignimbrite, Paycuqui, Argentina

USGS Publications Warehouse

Wright, Heather M.; Lesti, Chiara; Cas, Ray A.F.; Porreca, Massimiliano; Viramonte, Jose G.; Folkes, Christopher B.; Giordano, Guido

2011-01-01

Columnar jointing is thought to occur primarily in lavas and welded pyroclastic flow deposits. However, the non-welded Cerro Galán Ignimbrite at Paycuqui, Argentina, contains well-developed columnar joints that are instead due to high-temperature vapor-phase alteration of the deposit, where devitrification and vapor-phase crystallization have increased the density and cohesion of the upper half of the section. Thermal remanent magnetization analyses of entrained lithic clasts indicate high emplacement temperatures, above 630°C, but the lack of welding textures indicates temperatures below the glass transition temperature. In order to remain below the glass transition at 630°C, the minimum cooling rate prior to deposition was 3.0 × 10−3–8.5 × 10−2°C/min (depending on the experimental data used for comparison). Alternatively, if the deposit was emplaced above the glass transition temperature, conductive cooling alone was insufficient to prevent welding. Crack patterns (average, 4.5 sides to each polygon) and column diameters (average, 75 cm) are consistent with relatively rapid cooling, where advective heat loss due to vapor fluxing increases cooling over simple conductive heat transfer. The presence of regularly spaced, complex radiating joint patterns is consistent with fumarolic gas rise, where volatiles originated in the valley-confined drainage system below. Joint spacing is a proxy for cooling rates and is controlled by depositional thickness/valley width. We suggest that the formation of joints in high-temperature, non-welded deposits is aided by the presence of underlying external water, where vapor transfer causes crystallization in pore spaces, densifies the deposit, and helps prevent welding.

E-cigarette use, perceptions, and cigarette smoking intentions in a community sample of young adult nondaily cigarette smokers.

PubMed

Brikmanis, Kristin; Petersen, Angela; Doran, Neal

2017-05-01

E-cigarettes have been suggested as a strategy for reducing harm from cigarettes. Although e-cigarettes could be a less-harmful alternative to cigarettes for those trying to quit, there may also be costs that outweigh any benefits of reduction. The purpose of the present study was to prospectively investigate perceptions of e-cigarettes, cigarette smoking intentions, and their associations with e-cigarette use over time. Community participants (N = 348, 57% male) aged 18 to 24 years were recruited for a longitudinal study of tobacco use. Inclusion criteria included nondaily cigarette smoking for ≥ 6 months with no history of daily smoking. Participants reported e-cigarette use over the past 14 days at baseline, and for the past 9 days at 3, 6, and 9 months. Assessments were completed online or via mobile phone. Across the 4 assessments, 22% to 33% of participants reported recent e-cigarette use. Intent to quit smoking cigarettes and intent to maintain smoking were unrelated to e-cigarette frequency. E-cigarette frequency was positively associated with perceiving e-cigarettes as less harmful than cigarettes and more positive e-cigarette expectancies (ps < .05). E-cigarette use was also more frequent among those who smoked cigarettes frequently and who used e-cigarettes to circumvent cigarette bans more often (ps < .05). The combination of these findings suggests that, at least among nondaily smoking young adults, other factors may influence frequency of e-cigarette use more than harm reduction. Findings instead seem consistent with the hypothesis that e-cigarettes are more often used to complement ongoing cigarette smoking. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Biodegradation of high concentrations of benzene vapors in a two phase partition stirred tank bioreactor.

PubMed

Karimi, Ali; Golbabaei, Farideh; Neghab, Masoud; Pourmand, Mohammad Reza; Nikpey, Ahmad; Mohammad, Kazem; Mehrnia, Momammad Reza

2013-01-15

The present study examined the biodegradation rate of benzene vapors in a two phase stirred tank bioreactor by a bacterial consortium obtained from wastewater of an oil industry refinery house. Initially, the ability of the microbial consortium for degrading benzene was evaluated before running the bioreactor. The gaseous samples from inlet and outlet of bioreactor were directly injected into a gas chromatograph to determine benzene concentrations. Carbone oxide concentration at the inlet and outlet of bioreactor were also measured with a CO2 meter to determine the mineralization rate of benzene. Influence of the second non-aqueous phase (silicon oil) has been emphasized, so at the first stage the removal efficiency (RE) and elimination capacity (EC) of benzene vapors were evaluated without any organic phase and in the second stage, 10% of silicon oil was added to bioreactor media as an organic phase. Addition of silicon oil increased the biodegradation performance up to an inlet loading of 5580 mg/m3, a condition at which, the elimination capacity and removal efficiency were 181 g/m3/h and 95% respectively. The elimination rate of benzene increased by 38% in the presence of 10% of silicone oil. The finding of this study demonstrated that two phase partition bioreactors (TPPBs) are potentially effective tools for the treatment of gas streams contaminated with high concentrations of poorly water soluble organic contaminant, such as benzene.

E-Cigarettes: A Review of New Trends in Cannabis Use.

PubMed

Giroud, Christian; de Cesare, Mariangela; Berthet, Aurélie; Varlet, Vincent; Concha-Lozano, Nicolas; Favrat, Bernard

2015-08-21

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

E-Cigarettes: A Review of New Trends in Cannabis Use

PubMed Central

Giroud, Christian; de Cesare, Mariangela; Berthet, Aurélie; Varlet, Vincent; Concha-Lozano, Nicolas; Favrat, Bernard

2015-01-01

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely “vape” deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination. PMID:26308021

Phase diagram of nanoscale alloy particles used for vapor-liquid-solid growth of semiconductor nanowires.

PubMed

Sutter, Eli; Sutter, Peter

2008-02-01

We use transmission electron microscopy observations to establish the parts of the phase diagram of nanometer sized Au-Ge alloy drops at the tips of Ge nanowires (NWs) that determine their temperature-dependent equilibrium composition and, hence, their exchange of semiconductor material with the NWs. We find that the phase diagram of the nanoscale drop deviates significantly from that of the bulk alloy, which explains discrepancies between actual growth results and predictions on the basis of the bulk-phase equilibria. Our findings provide the basis for tailoring vapor-liquid-solid growth to achieve complex one-dimensional materials geometries.

Electronic cigarettes and indoor air quality: a review of studies using human volunteers.

PubMed

Zainol Abidin, Najihah; Zainal Abidin, Emilia; Zulkifli, Aziemah; Karuppiah, Karmegam; Syed Ismail, Sharifah Norkhadijah; Amer Nordin, Amer Siddiq

2017-09-26

This paper is primarily aimed to review articles on electronic cigarettes (e-cigarettes) focusing on indoor air quality (IAQ) assessment that were conducted using human volunteers under natural settings that mimic actual vaping scenarios. Such studies may give a better representation of the actual potential exposure towards e-cigarettes emissions in indoor settings. A systematic literature search was conducted using PubMed search engine database. Search terms such as "electronic cigarette", "e-cigarette", "electronic nicotine delivery system", and "indoor air quality" were used to identify the relevant articles to be included in this review. Articles that involved human volunteers who were asked to vape in natural settings or settings that mimic the actual vaping scenario were chosen to be reviewed. The search yielded a total of 15 published articles. Eleven articles were excluded due to 1) unavailability of its full-text (n=1), 2) did not involve human volunteers (n=5) and 3) did not involve an IAQ study (n=5). Four articles were critically reviewed in this paper. From the four selected articles, two of the papers focused on the determination of nicotine level released by e-cigarettes whereas the other two covered IAQ parameters namely; particulate matters (PM), propylene glycols, formaldehyde, metals and polycyclic aromatic hydrocarbons (PAHs). Only two of the studies involved determination of biomarkers of exposure. The level of chemical contents released varied between studies. The differences in the brands of e-cigarette used, number of vapers recruited and the sensitivity of the methodologies employed in these studies may be the possible causes for such differences. However, studies using human volunteers conducted in a natural setting are more relevant to portray the actual exposure to vapors among e-cigarettes users and non-users compared to studies using a smoking machine/an exposure chamber. This is because such studies take into account the behavior of

Low temperature vapor phase digestion of graphite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, Robert A.

2017-04-18

A method for digestion and gasification of graphite for removal from an underlying surface is described. The method can be utilized to remove graphite remnants of a formation process from the formed metal piece in a cleaning process. The method can be particularly beneficial in cleaning castings formed with graphite molding materials. The method can utilize vaporous nitric acid (HNO.sub.3) or vaporous HNO.sub.3 with air/oxygen to digest the graphite at conditions that can avoid damage to the underlying surface.

Effects of e-Cigarette Advertisements on Adolescents' Perceptions of Cigarettes.

PubMed

Kim, Minji; Popova, Lucy; Halpern-Felsher, Bonnie; Ling, Pamela M

2017-12-13

This study examined the effect of exposure to "cigalike" (products resembling cigarettes) e-cigarette advertisements on adolescents' perceptions of cigarettes. A nationally representative sample of 802 adolescents (13-17 years old) was randomly assigned to watch three e-cigarette or three control advertisements. Never-smokers who saw the e-cigarette advertisements (n = 352) reported significantly lower perceived risks of smoking than those in the control condition (n = 320). Ever-smokers (n = 130) did not show significant differences across the conditions. In subgroup analyses, current smokers (reported smoking in the past 30 days, n = 31) in the e-cigarette condition reported significantly lower perceived benefits of smoking than those in the control condition. E-cigarette advertisements can affect adolescents' perceptions of cigarettes. Many advertisements, especially the ones promoting "cigalikes," depict e-cigarettes as being similar to cigarettes (e.g., look, flavor) but also as a solution for cigarettes' shortcomings (e.g., bad smell). While the advertisements include messages about problems posed by cigarettes, proposing e-cigarettes as a solution may decrease the perceived risks of smoking among never-smokers. It may also not be clear to adolescents whether advertisements are for cigarettes or e-cigarettes. Regulating e-cigarette advertisements to minimize adolescents' exposure may prevent potential harmful effects on never-smokers' perception of smoking.

E-Cigarette Use, Perceptions, and Cigarette Smoking Intentions in a Community Sample of Young Adult Non-Daily Cigarette Smokers

PubMed Central

Brikmanis, Kristin; Petersen, Angela; Doran, Neal

2017-01-01

E-cigarettes have been suggested as a strategy for reducing harm from cigarettes. While e-cigarettes could be a less-harmful alternative to cigarettes for those trying to quit, there may also be costs that outweigh any benefits of reduction. The purpose of the present study was to prospectively investigate perceptions of e-cigarettes, cigarette smoking intentions and their associations with e-cigarette use over time. Community participants (n = 348, 57% male) aged 18–24 were recruited for a longitudinal study of tobacco use. Inclusion criteria included non-daily cigarette smoking for ≥ 6 months with no history of daily smoking. Participants reported e-cigarette use over the past 14 days at baseline and for the past 9 days at 3, 6, and 9 months. Assessments were completed online or via mobile phone. Across the 4 assessments, 22–33% of participants reported recent e-cigarette use. Intent to quit smoking cigarettes and intent to maintain smoking were unrelated to e-cigarette frequency. E-cigarette frequency was positively associated with perceiving e-cigarettes as less harmful than cigarettes and more positive e-cigarette expectancies (ps < .05). E-cigarette use was also more frequent among those who smoked cigarettes frequently and who used e-cigarettes to circumvent cigarette bans more often (ps < .05). The combination of these findings suggests that, at least among non-daily smoking young adults, other factors may influence frequency of e-cigarette use more than harm reduction. Findings instead seem consistent with the hypothesis that e-cigarettes are more often used to complement ongoing cigarette smoking. PMID:28125242

Simultaneous imaging of fuel vapor mass fraction and gas-phase temperature inside gasoline sprays using two-line excitation tracer planar laser-induced fluorescence.

PubMed

Zigan, Lars; Trost, Johannes; Leipertz, Alfred

2016-02-20

This paper reports for the first time, to the best of our knowledge, on the simultaneous imaging of the gas-phase temperature and fuel vapor mass fraction distribution in a direct-injection spark-ignition (DISI) spray under engine-relevant conditions using tracer planar laser-induced fluorescence (TPLIF). For measurements in the spray, the fluorescence tracer 3-pentanone is added to the nonfluorescent surrogate fuel iso-octane, which is excited quasi-simultaneously by two different excimer lasers for two-line excitation LIF. The gas-phase temperature of the mixture of fuel vapor and surrounding gas and the fuel vapor mass fraction can be calculated from the two LIF signals. The measurements are conducted in a high-temperature, high-pressure injection chamber. The fluorescence calibration of the tracer was executed in a flow cell and extended significantly compared to the existing database. A detailed error analysis for both calibration and measurement is provided. Simultaneous single-shot gas-phase temperature and fuel vapor mass fraction fields are processed for the assessment of cyclic spray fluctuations.

Electronic cigarettes are a source of thirdhand exposure to nicotine.

PubMed

Goniewicz, Maciej L; Lee, Lily

2015-02-01

Substances remaining on the surfaces in areas where people have smoked contribute to thirdhand exposure. Nicotine from tobacco smoke has been shown to react with oxidizing chemicals in the air to form secondary pollutants, such as carcinogenic nitrosamines. While previous studies have demonstrated thirdhand exposure to nicotine from tobacco smoke, none have investigated whether nicotine from electronic cigarettes (e-cigarettes) can also be deposited on various surfaces. Three brands of e-cigarettes were refilled with varying nicotine concentrations. We released 100 puffs from each product directly into an exposure chamber. Surface wipe samples were taken from 5 indoor 100 cm(2) surfaces (window, walls, floor, wood, and metal) pre- and post-release of vapors. Nicotine was extracted from the wipes and was analyzed using gas chromatography. Three of the 4 experiments showed significant increases in the amount of nicotine on all five surfaces. The floor and glass windows had the greatest increases in nicotine, on average by a factor of 47 and 6, respectively (p < .05). The average amount of nicotine deposited on a floor during each experiment was 205 μg/m(2) and varied from limit of quantitation to 550 μg/m(2). This study indicates that there is a risk for thirdhand exposure to nicotine from e-cigarettes. Thirdhand exposure levels differ depending on the surface and the e-cigarette brand. Future research should explore the potential risks of thirdhand exposure to carcinogens formed from the nicotine that is released from e-cigarettes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Self-reported smoking effects and comparative value between cigarettes and high dose e-cigarettes in nicotine-dependent cigarette smokers.

PubMed

McPherson, Sterling; Howell, Donelle; Lewis, Jennifer; Barbosa-Leiker, Celestina; Bertotti Metoyer, Patrick; Roll, John

2016-04-01

The objective of this experiment was to evaluate the comparative value of cigarettes versus high dose e-cigarettes among nicotine-dependent cigarette smokers when compared with money or use of their usual cigarette brand. The experiment used a within-subject design with four sessions. After baseline assessment, participants attended two 15-min unrestricted smoking sessions: one cigarette smoking session and one e-cigarette smoking session. Participants then attended two multiple-choice procedure (MCP) sessions: a session comparing cigarettes and money and a session comparing e-cigarettes and money. Participants (n=27) had used cigarettes regularly, had never used e-cigarettes, and were not currently attempting to quit smoking. The sample consisted primarily of males (72%), with a mean age of 34 years. When given the opportunity to choose between smoking a cigarette or an e-cigarette, participants chose the cigarette 73.9% of the time. Findings from the MCP demonstrated that after the first e-cigarette exposure sessions, the crossover value for cigarettes ($3.45) was significantly higher compared with the crossover value for e-cigarettes ($2.73). The higher participant preference, self-reported smoking effects, and higher MCP crossover points indicate that cigarettes have a higher comparative value than high dose e-cigarettes among e-cigarette naive smokers.

The gas phase emitter effect of lanthanum within ceramic metal halide lamps and its dependence on the La vapor pressure and operating frequency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruhrmann, C.; Hoebing, T.; Bergner, A.

2015-08-07

The gas phase emitter effect increases the lamp lifetime by lowering the work function and, with it, the temperature of the tungsten electrodes of metal halide lamps especially for lamps in ceramic vessels due to their high rare earth pressures. It is generated by a monolayer on the electrode surface of electropositive atoms of certain emitter elements, which are inserted into the lamp bulb by metal iodide salts. They are vaporized, dissociated, ionized, and deposited by an emitter ion current onto the electrode surface within the cathodic phase of lamp operation with a switched-dc or ac-current. The gas phase emittermore » effect of La and the influence of Na on the emitter effect of La are studied by spatially and phase-resolved pyrometric measurements of the electrode tip temperature, La atom, and ion densities by optical emission spectroscopy as well as optical broadband absorption spectroscopy and arc attachment images by short time photography. An addition of Na to the lamp filling increases the La vapor pressure within the lamp considerably, resulting in an improved gas phase emitter effect of La. Furthermore, the La vapor pressure is raised by a heating of the cold spot. In this way, conditions depending on the La vapor pressure and operating frequency are identified, at which the temperature of the electrodes becomes a minimum.« less

A longitudinal study of the relationship between receptivity to e-cigarette advertisements and e-cigarette use among baseline non-users of cigarettes and e-cigarettes, United States.

PubMed

Agaku, Israel T; Davis, Kevin; Patel, Deesha; Shafer, Paul; Cox, Shanna; Ridgeway, William; King, Brian A

2017-01-01

We investigated the relationship between receptivity to electronic cigarette (e-cigarette) advertisements at baseline and e-cigarette use at follow-up among adult baseline non-users of cigarettes and e-cigarettes. A nationally representative online panel was used to survey non-users of cigarettes and e-cigarettes ( n  = 2191) at baseline and 5-month follow-up. At baseline, respondents were shown an e-cigarette advertisement and asked if they were aware of it (exposure). Among those exposed, receptivity was self-rated for each ad using a validated scale of 1 to 5 for agreement with each of six items: "worth remembering," "grabbed my attention," "powerful," "informative," "meaningful," and "convincing." Logistic regression was used to measure the relationship between receptivity at baseline and e-cigarette use at follow-up. Among baseline non-users of cigarettes and e-cigarettes, 16.6% reported exposure to e-cigarette advertisements at baseline; overall mean receptivity score was 2.77. Among baseline non-users who reported exposure to e-cigarette advertisements, incidence of e-cigarette use at follow-up was 2.7%; among baseline non-users who reported not being exposed to e-cigarette advertisements, incidence of e-cigarette use at follow-up was 1.3%. The attributable risk percentage for e-cigarette initiation from e-cigarette advertisement exposure was 59.3%; the population attributable risk percentage from e-cigarette advertisement exposure was 22.6%. Receptivity at baseline was associated with e-cigarette use at follow-up (aOR = 1.57; 95% CI = 1.04-2.37). Receptivity to e-cigarette advertisements at baseline was associated with greater odds of e-cigarette use at follow-up among baseline non-users of cigarettes and e-cigarettes. Understanding the role of advertising in e-cigarette initiation could help inform public health policy.

Receptivity to e-cigarette marketing, harm perceptions, and e-cigarette use.

PubMed

Pokhrel, Pallav; Fagan, Pebbles; Kehl, Lisa; Herzog, Thaddeus A

2015-01-01

To test whether exposure and receptivity to e-cigarette marketing are associated with recent e-cigarette use among young adults through increased beliefs that e-cigarettes are less harmful than cigarettes. Data were collected from 307 multiethnic 4- and 2-year college students; approximately equal proportions of current, never, and former cigarette smokers [mean age = 23.5 (SD = 5.5); 65% female]. Higher receptivity to e-cigarette marketing was associated with perceptions that e-cigarettes are less harmful than cigarettes, which in turn, were associated with higher recent e-cigarette use. The findings provide preliminary support to the proposition that marketing of e-cigarettes as safer alternatives to cigarettes or cessation aids is associated with increased e-cigarette use among young adults. The findings have implications for development of e-cigarette regulations.

Real-Time Measurement of Electronic Cigarette Aerosol Size Distribution and Metals Content Analysis

PubMed Central

Brinkman, Marielle C.; Granville, Courtney A.; Gordon, Sydney M.; Clark, Pamela I.

2016-01-01

Introduction: Electronic cigarette (e-cigarette) use is increasing worldwide and is highest among both daily and nondaily smokers. E-cigarettes are perceived as a healthier alternative to combustible tobacco products, but their health risk factors have not yet been established, and one of them is lack of data on aerosol size generated by e-cigarettes. Methods: We applied a real-time, high-resolution aerosol differential mobility spectrometer to monitor the evolution of aerosol size and concentration during puff development. Particles generated by e-cigarettes were immediately delivered for analysis with minimal dilution and therefore with minimal sample distortion, which is critically important given the highly dynamic aerosol/vapor mixture inherent to e-cigarette emissions. Results: E-cigarette aerosols normally exhibit a bimodal particle size distribution: nanoparticles (11–25nm count median diameter) and submicron particles (96–175nm count median diameter). Each mode has comparable number concentrations (107–108 particles/cm3). “Dry puff” tests conducted with no e-cigarette liquid (e-liquid) present in the e-cigarette tank demonstrated that under these conditions only nanoparticles were generated. Analysis of the bulk aerosol collected on the filter showed that e-cigarette emissions contained a variety of metals. Conclusions: E-cigarette aerosol size distribution is different from that of combustible tobacco smoke. E-cigarettes generate high concentrations of nanoparticles and their chemical content requires further investigation. Despite the small mass of nanoparticles, their toxicological impact could be significant. Toxic chemicals that are attached to the small nanoparticles may have greater adverse health effects than when attached to larger submicron particles. Implications: The e-cigarette aerosol size distribution is different from that of combustible tobacco smoke and typically exhibits a bimodal behavior with comparable number concentrations

Influence of Smoking Puff Parameters and Tobacco Varieties on Free Radicals Yields in Cigarette Mainstream Smoke.

PubMed

Goel, Reema; Bitzer, Zachary T; Reilly, Samantha M; Foulds, Jonathan; Muscat, Joshua; Elias, Ryan J; Richie, John P

2018-05-07

Cigarette smoke is a major exogenous source of free radicals, and the resulting oxidative stress is one of the major causes of smoking-caused diseases. Yet, many of the factors that impact free radical delivery from cigarettes remain unclear. In this study, we machine-smoked cigarettes and measured the levels of gas- and particulate-phase radicals by electron paramagnetic resonance (EPR) spectroscopy using standardized smoking regimens (International Organization of Standardization (ISO) and Canadian Intense (CI)), puffing parameters, and tobacco blends. Radical delivery per cigarette was significantly greater in both gas (4-fold) and particulate (6-fold) phases when cigarettes were smoked under the CI protocol compared to the ISO protocol. Total puff volume per cigarette was the major factor with radical production being proportional to total volume, regardless of whether volume differences were achieved by changes in individual puff volume or puff frequency. Changing puff shape (bell vs sharp vs square) or puff duration (1-5 s), without changing volume, had no effect on radical yields. Tobacco variety did have a significant impact on free radical production, with gas-phase radicals highest in reconstituted > burley > oriental > bright tobacco and particulate-phase radicals highest in burley > bright > oriental > reconstituted tobacco. Our findings show that modifiable cigarette design features and measurable user smoking behaviors are key factors determining free radical exposure in smokers.

Receptivity to E-cigarette Marketing, Harm Perceptions, and E-cigarette Use

PubMed Central

Pokhrel, Pallav; Fagan, Pebbles; Kehl, Lisa; Herzog, Thaddeus A.

2016-01-01

Objective To test whether exposure and receptivity to e-cigarette marketing are associated with recent e-cigarette use among young adults through increased beliefs that e-cigarettes are less harmful than cigarettes. Methods Data were collected from 307 multiethnic 4- and 2-year college students; approximately equal proportions of current, never, and former cigarette smokers [mean age = 23.5 (SD = 5.5); 65% female]. Results Higher receptivity to e-cigarette marketing was associated with perceptions that e-cigarettes are less harmful than cigarettes, which in turn, were associated with higher recent e-cigarette use. Conclusions The findings provide preliminary support to the proposition that marketing of e-cigarettes as safer alternatives to cigarettes or cessation aids is associated with increased e-cigarette use among young adults. The findings have implications for development of e-cigarette regulations. PMID:25290604

E-cigarette Use and Cigarette Smoking Cessation among Texas College Students.

PubMed

Mantey, Dale S; Cooper, Maria R; Loukas, Alexandra; Perry, Cheryl L

2017-11-01

We examined the relationships between e-cigarette use and subsequent cigarette smoking behaviors at 6- and 12-month follow-ups among young adults. Participants were 18-29 year-old current and former cigarette smokers (N = 627) at 24 Texas colleges, participating in a 3-wave study. Multi-level, multivariable logistic regression models, accounting for school clustering, examined the impact of self-reported use of e-cigarettes on cigarette smoking status at 6- and 12-month follow-ups. Two mutually-exclusive groups of e-cigarette users were examined: those that used for cigarette smoking cessation and those that used for reasons other than cessation. Baseline covariates included socio-demographics, past quit attempts, nicotine dependence, cigarettes per day, and other tobacco use. Use of e-cigarettes for cigarette smoking cessation was associated with increased odds of cigarette smoking cessation at 6- and 12-month follow-ups, while using e-cigarettes for other reasons was not, when adjusting for covariates. Use of e-cigarettes for cigarette smoking cessation may reduce cigarette smoking rates in young adult college students. Additional research is needed examining e-cigarettes as a complement to evidence-based cessation resources that are associated with cigarette smoking cessation among young adults.

Infrared spectroscopic studies of the conformation in ethyl alpha-haloacetates in the vapor, liquid and solid phases.

PubMed

Jassem, Naserallah A; El-Bermani, Muhsin F

2010-07-01

Infrared spectra of ethyl alpha-fluoroacetate, ethyl alpha-chloroacetate, ethyl alpha-bromoacetate and ethyl alpha-iodoacetate have been measured in the solid, liquid and vapor phases in the region 4000-200 cm(-1). Vibrational frequency assignment of the observed bands to the appropriate modes of vibration was made. Calculations at DFT B3LYP/6-311+G** level, Job: conformer distribution, using Spartan program '08, release 132 was made to determine which conformers exist in which molecule. The results indicated that the first compound exists as an equilibrium mixture of cis and trans conformers and the other three compounds exist as equilibrium mixtures of cis and gauche conformers. Enthalpy differences between the conformers have been determined experimentally for each compound and for every phase. The values indicated that the trans of the first compound is more stable in the vapor phase, while the cis is the more stable in both the liquid and solid phases. In the other three compounds the gauche is more stable in the vapor and liquid phases, while the cis conformer is the more stable in the solid phase for each of the second and third compound, except for ethyl alpha-iodoacetate, the gauche conformer is the more stable over the three phases. Molar energy of activation Ea and the pseudo-thermodynamic parameters of activation DeltaH(double dagger), DeltaS(double dagger) and DeltaG(double dagger) were determined in the solid phase by applying Arrhenius equation; using bands arising from single conformers. The respective E(a) values of these compounds are 5.1+/-0.4, 6.7+/-0.1, 7.5+/-1.3 and 12.0+/-0.6 kJ mol(-1). Potential energy surface calculations were made at two levels; for ethyl alpha-fluoroacetate and ethyl alpha-chloroacetate; the calculations were established at DFT B3LYP/6-311+G** level and for ethyl alpha-bromoacetate and ethyl alpha-iodoacetate at DFT B3LYP/6-311G* level. The results showed no potential energy minimum exists for the gauche conformer in

E-cigarettes: An update on considerations for the otolaryngologist.

PubMed

Biyani, Sneh; Derkay, Craig S

2017-03-01

We provide an update in the literature and national regulations regarding electronic cigarettes with special attention to the pediatric population. Electronic nicotine delivery systems (ENDS) are handheld battery operated devices that vaporize nicotine-containing liquids for inhalation. Use of these products has dramatically increased over the last several years, particularly among the youth. ENDS are being marketed with advertising techniques and flavors which appeal to the adolescent and young adult population. More reports of accidental pediatric exposures are being documented, as are suicides from abuse of liquid nicotine. Federal regulation has only now become required of these devices. Use of e cigarettes among adolescents increases each year. Government oversight is needed to protect our children from the re-normalization of tobacco. Otolaryngologists should be prepared to counsel their patients and families regarding the latest in ENDS use. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro toxicity testing of cigarette smoke based on the air-liquid interface exposure: A review.

PubMed

Li, Xiang

2016-10-01

Cigarette smoke is a complex aerosol comprising particulate phase and gaseous vapour phase. The air-liquid interface exposure provides a possible technical means to implement whole smoke exposure for the assessment of tobacco products. In this review, the research progress in the in vitro toxicity testing of cigarette smoke based on the air-liquid interface exposure is summarized. The contents presented involve mainly cytotoxicity, genotoxicity, oxidative stress, inflammation, systems toxicology, 3D culture and cigarette smoke dosimetry related to cigarette smoke, as well as the assessment of electronic cigarette aerosol. Prospect of the application of the air-liquid interface exposure method in assessing the biological effects of tobacco smoke is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of eugenol, anethole, and coumarin in the mainstream cigarette smoke of Indonesian clove cigarettes.

PubMed

Polzin, Gregory M; Stanfill, Stephen B; Brown, Candace R; Ashley, David L; Watson, Clifford H

2007-10-01

Indonesian clove cigarettes (kreteks), typically have the appearance of a conventional domestic cigarette. The unique aspects of kreteks are that in addition to tobacco they contain dried clove buds (15-40%, by wt.), and are flavored with a proprietary "sauce". Whereas the clove buds contribute to generating high levels of eugenol in the smoke, the "sauce" may also contribute other potentially harmful constituents in addition to those associated with tobacco use. We measured levels of eugenol, trans-anethole (anethole), and coumarin in smoke from 33 brands of clove-flavored cigarettes (filtered and unfiltered) from five kretek manufacturers. In order to provide information for evaluating the delivery of these compounds under standard smoking conditions, a quantification method was developed for their measurement in mainstream cigarette smoke. The method allowed collection of mainstream cigarette smoke particulate matter on a Cambridge filter pad, extraction with methanol, sampling by automated headspace solid-phase microextraction, and subsequent analysis using gas chromatography/mass spectrometry. The presence of these compounds was confirmed in the smoke of kreteks using mass spectral library matching, high-resolution mass spectrometry (+/-0.0002 amu), and agreement with a relative retention time index, and native standards. We found that when kreteks were smoked according to standardized machine smoke parameters as specified by the International Standards Organization, all 33 clove brands contained levels of eugenol ranging from 2,490 to 37,900 microg/cigarette (microg/cig). Anethole was detected in smoke from 13 brands at levels of 22.8-1,030 microg/cig, and coumarin was detected in 19 brands at levels ranging from 9.2 to 215 microg/cig. These detected levels are significantly higher than the levels found in commercial cigarette brands available in the United States.

In vivo droplet vaporization for occlusion therapy and phase aberration correction.

PubMed

Kripfgans, Oliver D; Fowlkes, J Brian; Woydt, Michael; Eldevik, Odd P; Carson, Paul L

2002-06-01

The objective was to determine whether a transpulmonary droplet emulsion (90%, <6 microm diameter) could be used to form large gas bubbles (>30 microm) temporarily in vivo. Such bubbles could occlude a targeted capillary bed when used in a large number density. Alternatively, for a very sparse population of droplets, the resulting gas bubbles could serve as point beacons for phase aberration corrections in ultrasonic imaging. Gas bubbles can be made in vivo by acoustic droplet vaporization (ADV) of injected, superheated, dodecafluoropentane droplets. Droplets vaporize in an acoustic field whose peak rarefactional pressure exceeds a well-defined threshold. In this new work, it has been found that intraarterial and intravenous injections can be used to introduce the emulsion into the blood stream for subsequent ADV (B- and M-mode on a clinical scanner) in situ. Intravenous administration results in a lower gas bubble yield, possibly because of filtering in the lung, dilution in the blood volume, or other circulatory effects. Results show that for occlusion purposes, a reduction in regional blood flow of 34% can be achieved. Individual point beacons with a +24 dB backscatter amplitude relative to white matter were created by intravenous injection and ADV.

Upright and Inverted Single-Junction GaAs Solar Cells Grown by Hydride Vapor Phase Epitaxy

DOE PAGES

Simon, John; Schulte, Kevin L.; Jain, Nikhil; ...

2016-10-19

Hydride vapor phase epitaxy (HVPE) is a low-cost alternative to conventional metal-organic vapor phase epitaxy (MOVPE) growth of III-V solar cells. In this work, we show continued improvement of the performance of HVPE-grown single-junction GaAs solar cells. We show over an order of magnitude improvement in the interface recombination velocity between GaAs and GaInP layers through the elimination of growth interrupts, leading to increased short-circuit current density and open-circuit voltage compared with cells with interrupts. One-sun conversion efficiencies as high as 20.6% were achieved with this improved growth process. Solar cells grown in an inverted configuration that were removed frommore » the substrate showed nearly identical performance to on-wafer cells, demonstrating the viability of HVPE to be used together with conventional wafer reuse techniques for further cost reduction. As a result, these devices utilized multiple heterointerfaces, showing the potential of HVPE for the growth of complex and high-quality III-V devices.« less

Vapor-phase and particulate-associated pesticides and PCB concentrations in eastern North Dakota air samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawthorne, S.B.; Miller, D.J.; Louie, P.K.K.

1996-05-01

Vapor-phase and suspended particulate (<50 {mu}m) samples were collected on polyurethane foam (PUF) and quartz fiber filters in rural North Dakota to determine the air concentrations of pesticides in an area where agriculture is a primary source of semivolatile pollutants. Samples were collected at two sites from 1992 to 1994 that were at least 0.4 km from the nearest farmed fields and known application of pesticides, and analyzed for 22 different organochlorine, triazine, and acid herbicide pesticides. Fourteen pesticides were found above the detection limits (typically <1 pg/m{sup 3}). Concentrations of polychlorinated biphenyl (PCB) congeners were much lower (<50 pg/m{supmore » 3} in all cases) than many of the pesticides. These results demonstrate that pesticides are among the most prevalent chlorinated semivolatile pollutants present in rural North Dakota, that significant transport of pesticides occurs both in the vapor-phase and on suspended particulate matter, and that blown soil may be a significant mechanism for introducing pesticides into surface and ground waters. 32 refs., 2 figs., 4 tabs.« less

Biofiltration - an innovative approach to vapor phase treatment at the Silvex hazardous waste site in Florida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartsfield, B.

1995-12-31

Biofiltration is an emerging technology that is being used for vapor phase treatment at the Silvex hazardous waste site. Biofiltration works by directing the off-gas from the groundwater treatment system through a bed of soil, compost or other medium that supports the growth of bacteria. Contaminants are absorbed into the water present in the medium, and are subsequently degraded by the microorganisms. The biofiltration system at the Silvex hazardous waste site has been effective in removing contaminants from the off-gas. The biofiltration system has also been effective in minimizing the odor problem resulting from mercaptans in the off-gas. Biofiltration hasmore » been used for many years at wastewater and industrial plants to control odor and remove organic contaminants. This technology has only recently been used for hazardous waste site cleanups. The hazardous waste literature is now listing biofiltration as a vapor phase treatment technology, along with carbon, thermal oxidation and others.« less

Adolescent Sports Participation, E-cigarette Use, and Cigarette Smoking.

PubMed

Veliz, Phil; McCabe, Sean Esteban; McCabe, Vita V; Boyd, Carol J

2017-11-01

Although sport participation among adolescents has been found to lower the risk of traditional cigarette smoking, no studies to date have assessed if this type of physical activity lowers the risk of e-cigarette use among adolescents. National data from the 2014 and 2015 Monitoring the Future study of 12th-grade students were used and analyses were conducted in 2016. Measures for past 30-day e-cigarette use and traditional cigarette smoking were used to assess differences between adolescents who participated in at least one competitive sport during the past year and adolescents who did not. Differences in e-cigarette use and traditional cigarette smoking were assessed between 13 different sports to determine which sports were associated with a greater or lower risk of these behaviors. Adolescents who participated in at least one competitive sport were less likely to engage in past 30-day traditional cigarette smoking (AOR=0.73, 95% CI=0.538, 0.973) and past 30-day dual use of traditional cigarettes and e-cigarettes (AOR=0.66, 95% CI=0.438, 0.982) when compared with their nonparticipating peers. Adolescents who participated in baseball/softball and wrestling were at greatest risk of e-cigarette use. Of the 13 assessed sports, none were found to lower the odds of e-cigarette use. No significant evidence was found that participation in a sport was a protective factor against e-cigarette use. Certain types of athletes are at an elevated risk of e-cigarette use, and prevention efforts targeted at these specific sports should be considered by school administrators. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Vapor-phase cristobalite as a durable indicator of magmatic pore structure and halogen degassing: an example from White Island volcano (New Zealand)

NASA Astrophysics Data System (ADS)

Ian Schipper, C.; Mandon, Céline; Maksimenko, Anton; Castro, Jonathan M.; Conway, Chris E.; Hauer, Peter; Kirilova, Martina; Kilgour, Geoff

2017-10-01

Vesicles in volcanic rocks are physical records of magmatic degassing; however, the interpretation of their textures is complicated by resorption, coalescence, and collapse. We discuss the textural significance of vesicle-hosted vapor-phase cristobalite (high-T, low-P SiO2 polymorph), and its utility as a complement to textural assessments of magmatic degassing, using a representative dacite bomb erupted from White Island volcano (New Zealand) in 1999. Imaging in 2D (SEM) and 3D (CT) shows the bomb to have 56% bulk porosity, almost all of which is connected ( 99%) and devoid of SiO2 phases. The remaining ( 1%) of porosity is in isolated, sub-spherical vesicles that have corroded walls and contain small (< 30 μm across) prismatic vapor-phase cristobalite crystals (98.4 ± 0.4 wt.% SiO2 with diagnostic laser Raman spectra). Halogen degassing models show vapor-phase cristobalite to be indicative of closed-system chlorine and fluorine partitioning into H2O-rich fluid in isolated pores. At White Island, this occurred during shallow (< 100s of meters) ascent and extensive ( 50%) groundmass crystallization associated with slow cooling in a volcanic plug. Pristine textures in this White Island bomb demonstrate the link between pore isolation and vapor-phase cristobalite deposition. We suggest that because these crystals have higher preservation potential than the bubbles in which they form, they can serve as durable, qualitative textural indicators of halogen degassing and pre-quench bubble morphologies in slowly cooled volcanic rocks (e.g., lava flows and domes), even where emplacement mechanisms have overprinted original bubble textures.

Vapor-phase infrared spectroscopy on solid organic compounds with a pulsed resonant photoacoustic detection scheme

NASA Astrophysics Data System (ADS)

Bartlome, Richard; Fischer, Cornelia; Sigrist, Markus W.

2005-08-01

There is a great need for a low cost and sensitive method to measure infrared spectra of solid organic compounds in the gas phase. To record such spectra, we propose an optical parametric generator-based photoacoustic spectrometer, which emits in the mid-infrared fingerprint region between 3 and 4 microns. In this system, the sample is heated in a vessel before entering a home built photoacoustic cell, where the gaseous molecules are excited by a tunable laser source with a frequency repetition rate that matches the first longitudinal resonance frequency of the photocaoustic cell. In a first phase, we have focused on low-melting point stimulants such as Nikethamide, Mephentermine sulfate, Methylephedrine, Ephedrine and Pseudoephedrine. The vapor-phase spectra of these doping substances were measured between 2800 and 3100 cm-1, where fundamental C-H stretching vibrations take place. Our spectra show notable differences with commercially available condensed phase spectra. Our scheme enables to measure very low vapor pressures of low-melting point (<160 °C) solid organic compounds. Furthermore, the optical resolution of 8 cm-1 is good enough to distinguish closely related chemical structures such as the Ephedra alkaloids Ephedrine and Methylephedrine, but doesn't allow to differentiate diastereoisomeric pairs such as Ephedrine and Pseudoephedrine, two important neurotransmitters which reveal different biological activities. Therefore, higher resolution and a system capable of measuring organic compounds with higher melting points are required.

Behavioral economic substitution between conventional cigarettes and e-cigarettes differs as a function of the frequency of e-cigarette use.

PubMed

Snider, Sarah E; Cummings, K Michael; Bickel, Warren K

2017-08-01

Models measuring the interactions between consumption of conventional cigarettes and electronic cigarettes (e-cigarettes) in the marketplace are becoming vital forecast tools as the popularity of e-cigarettes increases and policy on tobacco products changes. Behavioral economics, which involves the integration of psychology and consumer demand, can be used to measure individuals' purchase behavior under different marketplace conditions. Our goal was to measure hypothetical conventional cigarette and e-cigarette purchasing among smokers with varying e-cigarette use patterns. Daily cigarette smokers were recruited using Amazon Mechanical Turk, an online crowdsourcing tool. Participants were asked about their frequency of e-cigarette use and to complete hypothetical single and cross-commodity purchase tasks. Frequency of e-cigarette use differentially affected how individuals consumed both conventional and e- cigarettes in different hypothetical marketplace conditions. The present study demonstrates four main findings: 1) the demand for conventional cigarettes was the lowest in those with greater frequency of e-cigarette use, 2) the demand for e-cigarettes was the highest in those with greater frequency of e-cigarette use, 3) when both products were available together, daily e-cigarette users purchased more e-cigarettes, but e-cigarettes served as a substitute for cigarettes in all groups regardless of frequency of use, and 4) the demand for conventional cigarette demand was lower in frequent e-cigarette users when e-cigarettes were concurrently available. Together, these data suggest that price and marketplace conditions will impact purchasing behavior of conventional and e-cigarettes users heterogeneously. Therefore, frequency of use patterns should be considered when implementing novel policies and/or marketplace changes. Copyright © 2017 Elsevier B.V. All rights reserved.

Electronic cigarette: a possible substitute for cigarette dependence.

PubMed

Caponnetto, P; Russo, C; Bruno, C M; Alamo, A; Amaradio, M D; Polosa, R

2013-03-01

Cigarette smoking is the leading cause of premature mortality in western countries and it is important for smokers to stop as early as possible. Electronic cigarettes are a popular phenomenon of global proportion. Recent uncontrolled studies, reported that a certain number of smokers have quit using electronic cigarettes. This could hint a role for electronic cigarettes to be used for smoking cessation, and therefore merits further evaluation for this purpose. Besides vaporising nicotine to be inhaled, electronic cigarettes may also provide a coping mechanism for conditioned smoking cues by replacing some of the rituals associated with smoking gestures, and for these reasons cigarette could become a tool--if studied more extensively--in the fight against tobacco-related morbidity and mortality.

E-cigarettes and National Adolescent Cigarette Use: 2004–2014

PubMed Central

Dutra, Lauren M.

2017-01-01

BACKGROUND: E-cigarette use is rapidly increasing among adolescents in the United States, with some suggesting that e-cigarettes are the cause of declining youth cigarette smoking. We hypothesized that the decline in youth smoking changed after e-cigarettes arrived on the US market in 2007. METHODS: Data were collected by using cross-sectional, nationally representative school-based samples of sixth- through 12th-graders from 2004–2014 National Youth Tobacco Surveys (samples ranged from 16 614 in 2013 to 25 324 in 2004). Analyses were conducted by using interrupted time series of ever (≥1 puff) and current (last 30 days) cigarette smoking. Logistic regression was used to identify psychosocial risk factors associated with cigarette smoking in the 2004–2009 samples; this model was then applied to estimate the probability of cigarette smoking among cigarette smokers and e-cigarette users in the 2011–2014 samples. RESULTS: Youth cigarette smoking decreased linearly between 2004 and 2014 (P = .009 for ever smoking and P = .05 for current smoking), with no significant change in this trend after 2009 (P = .57 and .23). Based on the psychosocial model of smoking, including demographic characteristics, willingness to wear clothing with a tobacco logo, living with a smoker, likelihood of smoking in the next year, likelihood of smoking cigarettes from a friend, and use of tobacco products other than cigarettes or e-cigarettes, the model categorized <25% of current e-cigarette–only users (between 11.0% in 2012 and 23.1% in 2013) as current smokers. CONCLUSIONS: The introduction of e-cigarettes was not associated with a change in the linear decline in cigarette smoking among youth. E-cigarette–only users would be unlikely to have initiated tobacco product use with cigarettes. PMID:28115540

Analytical solutions for a soil vapor extraction model that incorporates gas phase dispersion and molecular diffusion

NASA Astrophysics Data System (ADS)

Huang, Junqi; Goltz, Mark N.

2017-06-01

To greatly simplify their solution, the equations describing radial advective/dispersive transport to an extraction well in a porous medium typically neglect molecular diffusion. While this simplification is appropriate to simulate transport in the saturated zone, it can result in significant errors when modeling gas phase transport in the vadose zone, as might be applied when simulating a soil vapor extraction (SVE) system to remediate vadose zone contamination. A new analytical solution for the equations describing radial gas phase transport of a sorbing contaminant to an extraction well is presented. The equations model advection, dispersion (including both mechanical dispersion and molecular diffusion), and rate-limited mass transfer of dissolved, separate phase, and sorbed contaminants into the gas phase. The model equations are analytically solved by using the Laplace transform with respect to time. The solutions are represented by confluent hypergeometric functions in the Laplace domain. The Laplace domain solutions are then evaluated using a numerical Laplace inversion algorithm. The solutions can be used to simulate the spatial distribution and the temporal evolution of contaminant concentrations during operation of a soil vapor extraction well. Results of model simulations show that the effect of gas phase molecular diffusion upon concentrations at the extraction well is relatively small, although the effect upon the distribution of concentrations in space is significant. This study provides a tool that can be useful in designing SVE remediation strategies, as well as verifying numerical models used to simulate SVE system performance.

The Inhibition of Vapor-Phase Corrosion. A Review

DTIC Science & Technology

1985-10-01

vaporization of the inhibitor in a nondissociated molecular form, followed by hydrolysis on the surface of the metal. The products of hydrolysis may...Patent No. 600328) was assigned to Shell in 1945 . Some time ago, camphor was used to protect military materials made of ferrous metals. Naphthalene vapor...reduce moisture, they also "reduce corrosion. More importantly, they decompose as they absorb water, and the decomposition products (as illustrated by

Weight Concerns and Use of Cigarettes and E-Cigarettes among Young Adults.

PubMed

Bennett, Brooke L; Pokhrel, Pallav

2018-05-28

Higher weight concerns have been associated with higher cigarette smoking, particularly among women, partly because smoking is perceived to limit appetite for food. E-cigarettes are increasingly used as an alternative to combustible cigarettes and are widely believed to be less harmful than cigarettes. Currently it is not known whether weight concerns are associated with e-cigarette use among young adults. In this study, we tested the association between weight concerns and cigarette and e-cigarette use and use susceptibility among young adults. Cross-sectional data were collected from college students (N = 470; M age = 20.9; SD = 2.1; 65% women). Results indicated that weight concerns were significantly associated with lifetime and current cigarette smoking status, current cigarette smoking frequency and cigarette use susceptibility (among never smokers), adjusting for demographics variables. Weight concerns were not associated with lifetime or current e-cigarette use status or e-cigarette use susceptibility, adjusting for demographics and cigarette use status. However, higher weight concerns were associated with higher frequency of current e-cigarette use, adjusting for demographic variables and current cigarette smoking frequency. These findings imply that even though weight concerns may not motivate e-cigarette use as strongly as cigarette use, weight concerns may influence higher intensity of e-cigarette use among users.

Recall of E-cigarette Advertisements and Adolescent E-cigarette Use.

PubMed

Nicksic, Nicole E; Harrell, Melissa B; Pérez, Adriana; Pasch, Keryn E; Perry, Cheryl L

2017-04-01

We examined the impact of e-cigarette advertising on e-cigarette use behaviors among youth over time. At baseline, 3907 students participated in a youth tobacco surveillance study from 2014-2015 and 2488 students completed a 6-month follow-up. Weighted logistic regression models investigated the recall of e-cigarette advertisements (TV/radio/billboards/retail/Internet) as a risk factor for e-cigarette perceived harm, use, and susceptibility. The odds of ever e-cigarette use was 3 times higher (AOR=2.99; 95% CI, 1.50-5.97) at 6-month follow-up among e-cigarette never-users who recalled e-cigarette advertisements in retail stores at baseline, compared to those who did not. Likewise, the odds of current e-cigarette use and susceptibility to e-cigarette use at 6-month follow-up were 2.03 (95% CI, 1.11-3.72) and 1.77 (95% CI, 1.20-2.61), respectively. Additionally, recall of e-cigarette advertisements on the Internet at baseline was significantly related to current use (AOR=2.17; 95% CI, 1.05-4.48) and susceptibility to use e-cigarettes (AOR=1.72;95% CI, 1.15-2.58) at 6-month follow-up. Recall of e-cigarette advertisements at point-of-sale and on the Internet was significantly associated with adolescent e-cigarette susceptibility and use, which supports the need to minimize adolescent exposure to these advertisements.

Recall of E-cigarette Advertisements and Adolescent E-cigarette Use

PubMed Central

Nicksic, Nicole E.; Harrell, Melissa B.; Pérez, Adriana; Pasch, Keryn E.; Perry, Cheryl L.

2017-01-01

Objective We examined the impact of e-cigarette advertising on e-cigarette use behaviors among youth over time. Methods At baseline, 3907 students participated in a youth tobacco surveillance study from 2014–2015 and 2488 students completed a 6-month follow-up. Weighted logistic regression models investigated the recall of e-cigarette advertisements (TV/radio/billboards/retail/Internet) as a risk factor for e-cigarette perceived harm, use, and susceptibility. Results The odds of ever e-cigarette use was 3 times higher (AOR=2.99; 95% CI, 1.50–5.97) at 6-month follow-up among e-cigarette never-users who recalled e-cigarette advertisements in retail stores at baseline, compared to those who did not. Likewise, the odds of current e-cigarette use and susceptibility to e-cigarette use at 6-month follow-up were 2.03 (95% CI, 1.11–3.72) and 1.77 (95% CI, 1.20–2.61), respectively. Additionally, recall of e-cigarette advertisements on the Internet at baseline was significantly related to current use (AOR=2.17; 95% CI, 1.05–4.48) and susceptibility to use e-cigarettes (AOR=1.72;95% CI, 1.15–2.58) at 6-month follow-up. Conclusions Recall of e-cigarette advertisements at point-of-sale and on the Internet was significantly associated with adolescent e-cigarette susceptibility and use, which supports the need to minimize adolescent exposure to these advertisements. PMID:29104901

Behavioral economic substitutability of e-cigarettes, tobacco cigarettes, and nicotine gum.

PubMed

Johnson, Matthew W; Johnson, Patrick S; Rass, Olga; Pacek, Lauren R

2017-07-01

The public health impact of e-cigarettes may depend on their substitutability for tobacco cigarettes. Dual users of e-cigarettes and tobacco cigarettes completed purchasing tasks in which they specified daily use levels under hypothetical conditions that varied the availability and price of e-cigarettes, tobacco cigarettes, and nicotine gum (for those with nicotine gum experience). When either e-cigarettes or tobacco cigarettes were the only available commodity, as price per puff increased, purchasing decreased, revealing similar reinforcement profiles. When available concurrently, as the price of tobacco puffs increased, purchasing of tobacco puffs decreased while purchasing of fixed-price e-cigarette puffs increased. Among those with nicotine gum experience, when the price of tobacco puffs was closest to the actual market value of tobacco puffs, e-cigarette availability decreased median tobacco puff purchases by 44% compared to when tobacco was available alone. In contrast, nicotine gum availability caused no decrease in tobacco puff purchases. E-cigarettes may serve as a behavioral economic substitute for tobacco cigarettes, and may be a superior substitute compared to nicotine gum in their ability to decrease tobacco use. Although important questions remain regarding the health impacts of e-cigarettes, these data are consistent with the possibility that e-cigarettes may serve as smoking cessation/reduction aids.

THE EFFECT OF WATER (VAPOR-PHASE) AND CARBON ON ELEMENTAL MERCURY REMOVAL IN A FLOW REACTOR

EPA Science Inventory

The paper gives results of studying the effect of vapor-phase moisture on elemental mercury (Hgo) removal by activated carbon (AC) in a flow reactor. tests involved injecting AC into both a dry and a 4% moisture nitrogen (N2) /Hgo gas stream. A bituminous-coal-based AC (Calgon WP...

Growth of NH4Cl Single Crystal from Vapor Phase in Vertical Furnace

NASA Astrophysics Data System (ADS)

Nigara, Yutaka; Yoshizawa, Masahito; Fujimura, Tadao

1983-02-01

A pure and internally stress-free single crystal of NH4Cl was grown successfully from the vapor phase. The crystal measured 1.6 cmφ× 2 cm and had the disordered CsCl structure, which was stable below 184°C. The crystal was grown in an ampoule in a vertical furnace, in which the vapor was efficiently transported both by diffusion and convection. In line with the growth mechanism of a single crystal, the temperature fluctuation (°C/min) on the growth interface was kept smaller than the product of the temperature gradient (°C/cm) and the growth rate (cm/min). The specific heat of the crystal was measured around -31°C (242 K) during cooling and heating cycles by AC calorimetry. The thermal hysteresis (0.4 K) obtained here was smaller than that (0.89 K) of an NH4Cl crystal grown from its aqueous solution with urea added as a habit modifier.

Liquid-phase and vapor-phase dehydration of organic/water solutions

DOEpatents

Huang, Yu [Palo Alto, CA; Ly, Jennifer [San Jose, CA; Aldajani, Tiem [San Jose, CA; Baker, Richard W [Palo Alto, CA

2011-08-23

Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.

E-cigarettes, Cigarettes, and the Prevalence of Adolescent Tobacco Use

PubMed Central

Urman, Robert; Leventhal, Adam M.; Gauderman, W. James; Cruz, Tess Boley; Gilreath, Tamika D.; Howland, Steve; Unger, Jennifer B.; Berhane, Kiros; Samet, Jonathan M.; McConnell, Rob

2016-01-01

BACKGROUND: Adolescent e-cigarette use has increased rapidly in recent years, but it is unclear whether e-cigarettes are merely substituting for cigarettes or whether e-cigarettes are being used by those who would not otherwise have smoked. To understand the role of e-cigarettes in overall tobacco product use, we examine prevalence rates from Southern California adolescents over 2 decades. METHODS: The Children’s Health Study is a longitudinal study of cohorts reaching 12th grade in 1995, 1998, 2001, 2004, and 2014. Cohorts were enrolled from entire classrooms in schools in selected communities and followed prospectively through completion of secondary school. Analyses used data from grades 11 and 12 of each cohort (N = 5490). RESULTS: Among 12th-grade students, the combined adjusted prevalence of current cigarette or e-cigarette use in 2014 was 13.7%. This was substantially greater than the 9.0% adjusted prevalence of current cigarette use in 2004, before e-cigarettes were available (P = .003) and only slightly less than the 14.7% adjusted prevalence of smoking in 2001 (P = .54). Similar patterns were observed for prevalence rates in 11th grade, for rates of ever use, and among both male and female adolescents and both Hispanic and Non-Hispanic White adolescents. CONCLUSIONS: Smoking prevalence among Southern California adolescents has declined over 2 decades, but the high prevalence of combined e-cigarette or cigarette use in 2014, compared with historical Southern California smoking prevalence, suggests that e-cigarettes are not merely substituting for cigarettes and indicates that e-cigarette use is occurring in adolescents who would not otherwise have used tobacco products. PMID:27401102

College Students' Perceptions of Risk and Addictiveness of E-Cigarettes and Cigarettes

ERIC Educational Resources Information Center

Cooper, Maria; Loukas, Alexandra; Harrell, Melissa B.; Perry, Cheryl L.

2017-01-01

Background: As conventional cigarette use is declining, electronic cigarette ("e-cigarette") use is rising and is especially high among college students. Few studies examine dual use of e-cigarettes and cigarettes among this population. This study explores the relationship between dual and exclusive e-cigarette / cigarette use and…

An Evaluation of the Vapor Phase Catalytic Ammonia Removal Process for Use in a Mars Transit Vehicle

NASA Technical Reports Server (NTRS)

Flynn, Michael; Borchers, Bruce

1998-01-01

An experimental program has been developed to evaluate the potential of the Vapor Phase Catalytic Ammonia Reduction (VPCAR) technology for use as a Mars Transit Vehicle water purification system. Design modifications which will be required to ensure proper operation of the VPCAR system in reduced gravity are also evaluated. The VPCAR system is an integrated wastewater treatment technology that combines a distillation process with high temperature catalytic oxidation. The distillation portion of the system utilizes a vapor compression distillation process to provide an energy efficient phase change separation. This portion of the system removes any inorganic salts and large molecular weight, organic contaminates, i.e., non-volatile, from the product water stream and concentrates these contaminates into a byproduct stream. To oxidize the volatile organic compounds and ammonia, a vapor phase, high temperature catalytic oxidizer is used. This catalytic system converts these compounds along with the aqueous product into CO2, H2O, and N2O. A secondary catalytic bed can then be used to reduce the N2O to nitrogen and oxygen (although not evaluated in this study). This paper describes the design specification of the VPCAR process, the relative benefits of its utilization in a Mars Transit Vehicle, and the design modification which will be required to ensure its proper operation in reduced gravity. In addition, the results of an experimental evaluation of the processors is presented. This evaluation presents the processors performance based upon product water purity, water recovery rates, and power.

Vapor Wall Deposition in Chambers: Theoretical Considerations

NASA Astrophysics Data System (ADS)

McVay, R.; Cappa, C. D.; Seinfeld, J.

2014-12-01

In order to constrain the effects of vapor wall deposition on measured secondary organic aerosol (SOA) yields in laboratory chambers, Zhang et al. (2014) varied the seed aerosol surface area in toluene oxidation and observed a clear increase in the SOA yield with increasing seed surface area. Using a coupled vapor-particle dynamics model, we examine the extent to which this increase is the result of vapor wall deposition versus kinetic limitations arising from imperfect accommodation of organic species into the particle phase. We show that a seed surface area dependence of the SOA yield is present only when condensation of vapors onto particles is kinetically limited. The existence of kinetic limitation can be predicted by comparing the characteristic timescales of gas-phase reaction, vapor wall deposition, and gas-particle equilibration. The gas-particle equilibration timescale depends on the gas-particle accommodation coefficient αp. Regardless of the extent of kinetic limitation, vapor wall deposition depresses the SOA yield from that in its absence since vapor molecules that might otherwise condense on particles deposit on the walls. To accurately extrapolate chamber-derived yields to atmospheric conditions, both vapor wall deposition and kinetic limitations must be taken into account.

Pollution level and distribution of PCDD/PCDF congeners between vapor phase and particulate phase in winter air of Dalian, China.

PubMed

Wang, Wei; Qin, Songtao; Song, Yu; Xu, Qian; Ni, Yuwen; Chen, Jiping; Zhang, Xueping; Mu, Jim; Zhu, Xiuhua

2011-06-01

In December 2009, ambient air was sampled with active high-volume air samplers at two sites: on the roof of the No. l building of Dalian Jiaotong University and on the roof of the building of Dalian Meteorological Observatory. The concentrations and the congeners between vapor phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the air were measured. Sample analysis results showed that the concentrations of PCDD/Fs in particulate phase was higher than that in gaseous phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4 in all samples. The total I-TEQ value in gaseous phase and particulate phase was 5.5 and 453.8 fg/m(3) at Dalian Jiaotong University, 16.6 and 462.1 fg/m(3) at Dalian Meteorological Observatory, respectively. The I-TEQ value of Dalian atmosphere was 5.5-462.1 fg/m(3) which was lower than international standard, the atmospheric quality in Dalian is better. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

On the existence of vapor-liquid phase transition in dusty plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kundu, M.; Sen, A.; Ganesh, R.

2014-10-15

The phenomenon of phase transition in a dusty-plasma system (DPS) has attracted some attention in the past. Earlier Farouki and Hamaguchi [J. Chem. Phys. 101, 9876 (1994)] have demonstrated the existence of a liquid to solid transition in DPS where the dust particles interact through a Yukawa potential. However, the question of the existence of a vapor-liquid (VL) transition in such a system remains unanswered and relatively unexplored so far. We have investigated this problem by performing extensive molecular dynamics simulations which show that the VL transition does not have a critical curve in the pressure versus volume diagram formore » a large range of the Yukawa screening parameter κ and the Coulomb coupling parameter Γ. Thus, the VL phase transition is found to be super-critical, meaning that this transition is continuous in the dusty plasma model given by Farouki and Hamaguchi. We provide an approximate analytic explanation of this finding by means of a simple model calculation.« less

Levels of selected carcinogens and toxicants in vapour from electronic cigarettes.

PubMed

Goniewicz, Maciej Lukasz; Knysak, Jakub; Gawron, Michal; Kosmider, Leon; Sobczak, Andrzej; Kurek, Jolanta; Prokopowicz, Adam; Jablonska-Czapla, Magdalena; Rosik-Dulewska, Czeslawa; Havel, Christopher; Jacob, Peyton; Benowitz, Neal

2014-03-01

Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco. They are purported to deliver nicotine without other toxicants and to be a safer alternative to regular cigarettes. However, little toxicity testing has been performed to evaluate the chemical nature of vapour generated from e-cigarettes. The aim of this study was to screen e-cigarette vapours for content of four groups of potentially toxic and carcinogenic compounds: carbonyls, volatile organic compounds, nitrosamines and heavy metals. Vapours were generated from 12 brands of e-cigarettes and the reference product, the medicinal nicotine inhaler, in controlled conditions using a modified smoking machine. The selected toxic compounds were extracted from vapours into a solid or liquid phase and analysed with chromatographic and spectroscopy methods. We found that the e-cigarette vapours contained some toxic substances. The levels of the toxicants were 9-450 times lower than in cigarette smoke and were, in many cases, comparable with trace amounts found in the reference product. Our findings are consistent with the idea that substituting tobacco cigarettes with e-cigarettes may substantially reduce exposure to selected tobacco-specific toxicants. E-cigarettes as a harm reduction strategy among smokers unwilling to quit, warrants further study. (To view this abstract in Polish and German, please see the supplementary files online.).

Ethanol concentration in 56 refillable electronic cigarettes liquid formulations determined by headspace gas chromatography with flame ionization detector (HS-GC-FID).

PubMed

Poklis, Justin L; Wolf, Carl E; Peace, Michelle R

2017-10-01

Personal battery-powered vaporizers or electronic cigarettes were developed as an alternative to traditional cigarettes. The modern electronic cigarettes were patented in 2004 by Hon Lik in China. In May 2016, the US Food and Drug Administration (FDA) imposed regulatory statutes on e-cigarettes and their liquid formulations (e-liquids); prior to that, they were unregulated. E-liquids are typically composed of propylene glycol and/or glycerin, flavouring component(s), and active ingredient(s), such as nicotine. Fifty-six commercially available e-liquids, purchased from various sources, contained a variety of flavours and active ingredients. A headspace gas chromatography with flame ionization detector (HS-GC-FID) method was used to analyze these e-liquids for volatiles content. Only one of the e-liquids listed ethanol as a component. The chromatographic separation of volatiles was performed on a Restek BAC-1 column. A linear calibration was generated for ethanol with limits of detection and quantification (LOD/LOQ) of 0.05 mg/mL. Ethanol concentrations in the 56 e-liquids ranged from none detected to 206 mg/mL. The ethanol determined in these products may have been used in flavourants or a solvent; the reason for inclusion cannot be fully ascertained. The implications of vaporizing ethanol as an e-liquid component are unknown. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Real-Time Optical Monitoring and Simulations of Gas Phase Kinetics in InN Vapor Phase Epitaxy at High Pressure

NASA Technical Reports Server (NTRS)

Dietz, Nikolaus; Woods, Vincent; McCall, Sonya D.; Bachmann, Klaus J.

2003-01-01

Understanding the kinetics of nucleation and coalescence of heteroepitaxial thin films is a crucial step in controlling a chemical vapor deposition process, since it defines the perfection of the heteroepitaxial film both in terms of extended defect formation and chemical integrity of the interface. The initial nucleation process also defines the film quality during the later stages of film growth. The growth of emerging new materials heterostructures such as InN or In-rich Ga(x)In(1-x)N require deposition methods operating at higher vapor densities due to the high thermal decomposition pressure in these materials. High nitrogen pressure has been demonstrated to suppress thermal decomposition of InN, but has not been applied yet in chemical vapor deposition or etching experiments. Because of the difficulty with maintaining stochiometry at elevated temperature, current knowledge regarding thermodynamic data for InN, e.g., its melting point, temperature-dependent heat capacity, heat and entropy of formation are known with far less accuracy than for InP, InAs and InSb. Also, no information exists regarding the partial pressures of nitrogen and phosphorus along the liquidus surfaces of mixed-anion alloys of InN, of which the InN(x)P(1-x) system is the most interesting option. A miscibility gap is expected for InN(x)P(1-x) pseudobinary solidus compositions, but its extent is not established at this point by experimental studies under near equilibrium conditions. The extension of chemical vapor deposition to elevated pressure is also necessary for retaining stoichiometric single phase surface composition for materials that are characterized by large thermal decomposition pressures at optimum processing temperatures.

Effects of exposure to anti-vaping public service announcements among current smokers and dual users of cigarettes and electronic nicotine delivery systems.

PubMed

Tan, Andy S L; Rees, Vaughan W; Rodgers, Justin; Agudile, Emeka; Sokol, Natasha A; Yie, Kyeungyeun; Sanders-Jackson, Ashley

2018-07-01

Anti-vaping public service announcements (PSAs) are intended to discourage vaping or use of electronic nicotine delivery systems (ENDS). However, vaping portrayals in PSAs may have unintended effects if they increase smoking or vaping urges. This study examined benefits and unintended effects of anti-vaping PSAs with vapor portrayals on smoking and vaping-related outcomes. Young adult smokers (N = 171) and dual users (N = 122) aged 21-30 years were randomly assigned to view: 1) anti-vaping PSAs with vapor; 2) anti-vaping PSAs without vapor; 3) physical activity PSAs; or 4) anti-smoking PSAs with smoking cues. Outcomes were changes in vaping and smoking urges before and after viewing PSAs, post-test vaping and smoking intentions in the next hour, and post-test intention to purchase ENDS and traditional cigarettes. Smokers only: Exposure to anti-vaping PSAs with vapor (vs. physical activity) was associated with lower intention to vape and to purchase ENDS (ps < 0.001) and lower intention to smoke and purchase cigarettes (ps < 0.05). Exposure to anti-vaping PSAs with vapor (vs. PSAs without vapor and vs. anti-smoking PSAs with smoking cues) was associated with lower intention to vape in the next hour (ps < 0.05). Exposure to anti-vaping PSAs without vapor (vs. physical activity) was associated with lower change in vaping urge (p < 0.05) and intention to purchase ENDS (p < 0.001). Dual users: Exposure to anti-vaping PSAs without vapor (vs. anti-smoking PSAs) was associated with lower intention to purchase ENDS (p < 0.05). Viewing anti-vaping PSAs with vapor was not associated with unintended effects and may have benefits on reducing smoking and vaping-related outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

Real-Time Measurement of Electronic Cigarette Aerosol Size Distribution and Metals Content Analysis.

PubMed

Mikheev, Vladimir B; Brinkman, Marielle C; Granville, Courtney A; Gordon, Sydney M; Clark, Pamela I

2016-09-01

Electronic cigarette (e-cigarette) use is increasing worldwide and is highest among both daily and nondaily smokers. E-cigarettes are perceived as a healthier alternative to combustible tobacco products, but their health risk factors have not yet been established, and one of them is lack of data on aerosol size generated by e-cigarettes. We applied a real-time, high-resolution aerosol differential mobility spectrometer to monitor the evolution of aerosol size and concentration during puff development. Particles generated by e-cigarettes were immediately delivered for analysis with minimal dilution and therefore with minimal sample distortion, which is critically important given the highly dynamic aerosol/vapor mixture inherent to e-cigarette emissions. E-cigarette aerosols normally exhibit a bimodal particle size distribution: nanoparticles (11-25nm count median diameter) and submicron particles (96-175nm count median diameter). Each mode has comparable number concentrations (10(7)-10(8) particles/cm(3)). "Dry puff" tests conducted with no e-cigarette liquid (e-liquid) present in the e-cigarette tank demonstrated that under these conditions only nanoparticles were generated. Analysis of the bulk aerosol collected on the filter showed that e-cigarette emissions contained a variety of metals. E-cigarette aerosol size distribution is different from that of combustible tobacco smoke. E-cigarettes generate high concentrations of nanoparticles and their chemical content requires further investigation. Despite the small mass of nanoparticles, their toxicological impact could be significant. Toxic chemicals that are attached to the small nanoparticles may have greater adverse health effects than when attached to larger submicron particles. The e-cigarette aerosol size distribution is different from that of combustible tobacco smoke and typically exhibits a bimodal behavior with comparable number concentrations of nanoparticles and submicron particles. While vaping the e-cigarette

E-cigarette aerosols induce lower oxidative stress in vitro when compared to tobacco smoke.

PubMed

Taylor, Mark; Carr, Tony; Oke, Oluwatobiloba; Jaunky, Tomasz; Breheny, Damien; Lowe, Frazer; Gaça, Marianna

2016-07-01

Tobacco smoking is a risk factor for various diseases. The underlying cellular mechanisms are not fully characterized, but include oxidative stress, apoptosis, and necrosis. Electronic-cigarettes (e-cigarettes) have emerged as an alternative to and a possible means to reduce harm from tobacco smoking. E-cigarette vapor contains significantly lower levels of toxicants than cigarette smoke, but standardized methods to assess cellular responses to exposure are not well established. We investigated whether an in vitro model of the airway epithelium (human bronchial epithelial cells) and commercially available assays could differentiate cellular stress responses to aqueous aerosol extracts (AqE) generated from cigarette smoke and e-cigarette aerosols. After exposure to AqE concentrations of 0.063-0.500 puffs/mL, we measured the intracellular glutathione ratio (GSH:GSSG), intracellular generation of oxidant species, and activation of the nuclear factor erythroid-related factor 2 (Nrf2)-controlled antioxidant response elements (ARE) to characterize oxidative stress. Apoptotic and necrotic responses were characterized by increases in caspase 3/7 activity and reductions in viable cell protease activities. Concentration-dependent responses indicative of oxidative stress were obtained for all endpoints following exposure to cigarette smoke AqE: intracellular generation of oxidant species increased by up to 83%, GSH:GSSG reduced by 98.6% and transcriptional activation of ARE increased by up to 335%. Caspase 3/7 activity was increased by up to 37% and the viable cell population declined by up to 76%. No cellular stress responses were detected following exposure to e-cigarette AqE. The methods used were suitably sensitive to be employed for comparative studies of tobacco and nicotine products.

Dependence levels in users of electronic cigarettes, nicotine gums and tobacco cigarettes

PubMed Central

ETTER, Jean-François; EISSENBERG, Thomas

2016-01-01

Objective To assess dependence levels in users of e-cigarettes, and compare them with dependence levels in users of nicotine gums and tobacco cigarettes. Design Self-reports from cross-sectional Internet and mail surveys. Comparisons of: a) 766 daily users of nicotine-containing e-cigarettes with 30 daily users of nicotine-free e-cigarettes; b) 911 former smokers who used the e-cigarette daily with 451 former smokers who used the nicotine gum daily (but no e-cigarette); c) 125 daily e-cigarette users who smoked daily (dual users) with two samples of daily smokers who did not use e-cigarettes (2206 enrolled on the Internet and 292 enrolled by mail from the general population of Geneva). We used the Fagerström Test for Nicotine Dependence, the Nicotine Dependence Syndrome Scale, the Cigarette Dependence Scale and versions of these scales adapted for e-cigarettes and nicotine gums. Results Dependence ratings were slightly higher in users of nicotine-containing e-cigarettes than in users of nicotine-free e-cigarettes. In former smokers, long-term (>3 months) users of e-cigarettes were less dependent on e-cigarettes than long-term users of the nicotine gum were dependent on the gum. There were few differences in dependence ratings between short-term (<=3 months) users of gums or e-cigarettes. Dependence on e-cigarettes was generally lower in dual users than dependence on tobacco cigarettes in the two other samples of daily smokers. Conclusions Some e-cigarette users were dependent on nicotine-containing e-cigarettes, but these products were less addictive than tobacco cigarettes. E-cigarettes may be as or less addictive than nicotine gums, which themselves are not very addictive. PMID:25561385

Dependence levels in users of electronic cigarettes, nicotine gums and tobacco cigarettes.

PubMed

Etter, Jean-François; Eissenberg, Thomas

2015-02-01

To assess dependence levels in users of e-cigarettes, and compare them with dependence levels in users of nicotine gums and tobacco cigarettes. Self-reports from cross-sectional Internet and mail surveys. Comparisons of: (a) 766 daily users of nicotine-containing e-cigarettes with 30 daily users of nicotine-free e-cigarettes; (b) 911 former smokers who used the e-cigarette daily with 451 former smokers who used the nicotine gum daily (but no e-cigarette); (c) 125 daily e-cigarette users who smoked daily (dual users) with two samples of daily smokers who did not use e-cigarettes (2206 enrolled on the Internet and 292 enrolled by mail from the general population of Geneva). We used the Fagerström test for nicotine dependence, the nicotine dependence syndrome scale, the cigarette dependence scale and versions of these scales adapted for e-cigarettes and nicotine gums. Dependence ratings were slightly higher in users of nicotine-containing e-cigarettes than in users of nicotine-free e-cigarettes. In former smokers, long-term (>3 months) users of e-cigarettes were less dependent on e-cigarettes than long-term users of the nicotine gum were dependent on the gum. There were few differences in dependence ratings between short-term (≤3 months) users of gums or e-cigarettes. Dependence on e-cigarettes was generally lower in dual users than dependence on tobacco cigarettes in the two other samples of daily smokers. Some e-cigarette users were dependent on nicotine-containing e-cigarettes, but these products were less addictive than tobacco cigarettes. E-cigarettes may be as or less addictive than nicotine gums, which themselves are not very addictive. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Determination of Methane Hydrate Solubility in the Absence of Vapor Phase by in-situ Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Lu, W.; Chou, I.; Burruss, R.

2006-12-01

Prediction of the occurrence, distribution, and evolution of methane hydrate in porous marine sediments requires information on solubilities of methane hydrate in water. Solubilities of methane hydrate in the presence of a vapor phase are well established, but those in the absence of a vapor phase are not well defined with differences up to 30%. We have measured methane concentrations in pure water in equilibrium with sI methane hydrate, in the absence of vapor phase, by in-situ Raman spectroscopy at temperatures (T) from 2 to 20 (± 0.3) °C and pressures (P) at 10, 20, 30, and 40 (± 0.4%) MPa. Methane hydrate was synthesized in a high-pressure capillary optical cell (Chou et al., 2005; Advances in High-Pressure Technology for Geophysical Applications. Ed. J. Chen et al., Chapter 24, p. 475, Elsevier). A small quantity of methane was first loaded in an evacuated cell and then pressurized by water. Hydrate crystals were formed near the liquid-vapor interface near the enclosed end of the optical tube at room T, and were then placed at the center of a USGS-type heating-cooling stage. By adjusting sample P and T, the crystals went through dissolution-formation cycles three to four times in three days until the vapor phase was completely consumed and several crystals (typically 40 x 40 x 10 μm) were formed. These crystals were located at about 200 μm from the enclosed end and were about 20 to 40 μm from each other. Raman spectra were collected for the liquid phase adjacent to hydrate crystals near the enclosed end of the tube. A volumetric decrease in crystal size was observed away from the sampling spot; however, no such volumetric decrease was observed in or near the sampling spot. Therefore, equilibrium was likely established locally within the sampling area. The results are represented by the following linear isobaric equations: 10 MPa: ln [X(CH4)] = 0.06175 T - 6.79507; r2 = 0.9991 (n = 6) 20 MPa: ln [X(CH4)] = 0.06170 T - 6.82816; r2 = 0.9985 (n = 6) 30 MPa

Reaction mechanisms in the organometallic vapor phase epitaxial growth of GaAs

NASA Technical Reports Server (NTRS)

Larsen, C. A.; Buchan, N. I.; Stringfellow, G. B.

1988-01-01

The decomposition mechanisms of AsH3, trimethylgallium (TMGa), and mixtures of the two have been studied in an atmospheric-pressure flow system with the use of D2 to label the reaction products which are analyzed in a time-of-flight mass spectrometer. AsH3 decomposes entirely heterogeneously to give H2. TMGa decomposes by a series of gas-phase steps, involving methyl radicals and D atoms to produce CH3D, CH4, C2H6, and HD. TMGa decomposition is accelerated by the presence of AsH3. When the two are mixed, as in the organometallic vapor phase epitaxial growth of GaAs, both compounds decompose in concert to produce only CH4. A likely model is that of a Lewis acid-base adduct that forms and subsequently eliminates CH4.

Reaction mechanisms in the organometallic vapor phase epitaxial growth of GaAs

NASA Astrophysics Data System (ADS)

Larsen, C. A.; Buchan, N. I.; Stringfellow, G. B.

1988-02-01

The decomposition mechanisms of AsH3, trimethylgallium (TMGa), and mixtures of the two have been studied in an atmospheric-pressure flow system with the use of D2 to label the reaction products which are analyzed in a time-of-flight mass spectrometer. AsH3 decomposes entirely heterogeneously to give H2. TMGa decomposes by a series of gas-phase steps, involving methyl radicals and D atoms to produce CH3D, CH4, C2H6, and HD. TMGa decomposition is accelerated by the presence of AsH3. When the two are mixed, as in the organometallic vapor phase epitaxial growth of GaAs, both compounds decompose in concert to produce only CH4. A likely model is that of a Lewis acid-base adduct that forms and subsequently eliminates CH4.

Differences in the design and sale of e-cigarettes by cigarette manufacturers and non-cigarette manufacturers in the USA.

PubMed

Seidenberg, Andrew B; Jo, Catherine L; Ribisl, Kurt M

2016-04-01

Three categories of e-cigarette brands have emerged within the US market: e-cigarette brands developed by cigarette manufacturers, brands acquired by cigarette manufacturers and brands with no cigarette manufacturer affiliation. In the absence of federal regulatory oversight of e-cigarettes, we assessed differences in e-cigarette products and sales practices across these categories. Brand websites for top-selling e-cigarette brands from each of these categories were examined in October of 2015 to compare website access restrictions, online sales practices and products sold, including e-cigarette model type (eg, 'cigalike' vs advanced systems) and options available (eg, flavoured, nicotine free). Website access to brands developed by cigarette manufacturers was restricted to users aged 21 years or older, and one website required user registration. In addition, these brands were exclusively reusable/rechargeable 'cigalikes.' Limited flavour options were available for these products, and nicotine-free options were not sold. In contrast, brands acquired by cigarette manufacturers and brands with no cigarette manufacturer affiliation generally required website visitors to be 18, offered a nicotine-free option, and most offered disposable products and an array of flavoured products (eg, fruit/candy flavours). This exploratory study finds differences in e-cigarette products and sales practices across these three e-cigarette brand categories, with brands developed by cigarette manufacturers adopting a particularly distinctive product and sales strategy. Anticipated regulation of e-cigarettes in the USA may be influencing these product and sales decisions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

19 CFR 159.5 - Cigars, cigarettes, and cigarette papers and tubes.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 2 2013-04-01 2013-04-01 false Cigars, cigarettes, and cigarette papers and tubes...; DEPARTMENT OF THE TREASURY (CONTINUED) LIQUIDATION OF DUTIES General Provisions § 159.5 Cigars, cigarettes, and cigarette papers and tubes. The internal revenue taxes imposed on cigars, cigarettes, and...

19 CFR 159.5 - Cigars, cigarettes, and cigarette papers and tubes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 2 2014-04-01 2014-04-01 false Cigars, cigarettes, and cigarette papers and tubes...; DEPARTMENT OF THE TREASURY (CONTINUED) LIQUIDATION OF DUTIES General Provisions § 159.5 Cigars, cigarettes, and cigarette papers and tubes. The internal revenue taxes imposed on cigars, cigarettes, and...

19 CFR 159.5 - Cigars, cigarettes, and cigarette papers and tubes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 2 2011-04-01 2011-04-01 false Cigars, cigarettes, and cigarette papers and tubes...; DEPARTMENT OF THE TREASURY (CONTINUED) LIQUIDATION OF DUTIES General Provisions § 159.5 Cigars, cigarettes, and cigarette papers and tubes. The internal revenue taxes imposed on cigars, cigarettes, and...

19 CFR 159.5 - Cigars, cigarettes, and cigarette papers and tubes.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 2 2012-04-01 2012-04-01 false Cigars, cigarettes, and cigarette papers and tubes...; DEPARTMENT OF THE TREASURY (CONTINUED) LIQUIDATION OF DUTIES General Provisions § 159.5 Cigars, cigarettes, and cigarette papers and tubes. The internal revenue taxes imposed on cigars, cigarettes, and...

19 CFR 159.5 - Cigars, cigarettes, and cigarette papers and tubes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Cigars, cigarettes, and cigarette papers and tubes...; DEPARTMENT OF THE TREASURY (CONTINUED) LIQUIDATION OF DUTIES General Provisions § 159.5 Cigars, cigarettes, and cigarette papers and tubes. The internal revenue taxes imposed on cigars, cigarettes, and...

Adolescent Electronic Cigarette Use: Associations With Conventional Cigarette and Hookah Smoking.

PubMed

Barnett, Tracey E; Soule, Eric K; Forrest, Jamie R; Porter, Lauren; Tomar, Scott L

2015-08-01

The emerging trends and rapid growth of electronic cigarettes (e-cigarettes) among adolescents are being monitored closely. The trends are critical as policy to prevent uptake among adolescents is considered. The purpose of this study is to describe the prevalence of e-cigarette use and potential correlates for use. Associations between e-cigarettes, cigarettes, and hookah are assessed. This study used data from the 2013 Florida Youth Tobacco Survey. Prevalence estimates were calculated in 2014 and differences were determined based on CIs. Adjusted logistic regression models were used to identify correlates of e-cigarette use among participants based on demographic and other tobacco products used. There were no sex differences in middle school, whereas male high school students reported higher use than their female counterparts. Cigarette smoking and hookah use were significantly associated with ever and current e-cigarette use among both middle and high school students. Although e-cigarettes are being assessed as a potential replacement product for traditional tobacco, evidence from this study indicates the possibility of multiple product use among adolescents. E-cigarettes are not only associated with traditional cigarettes, but also with hookahs, a similar emerging product that offer tobacco flavors that may appeal to adolescents. Notably, many e-cigarette users also reported no cigarette or hookah use. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Electronic Cigarettes

MedlinePlus

... used to deliver marijuana and other drugs. Figure: Examples of e-cigarette products What is in e- ... to know what e-cigarette products contain. For example, some e-cigarettes marketed as containing zero percent ...

Investigations on the direct introduction of cigarette smoke for trace elements analysis by inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Chang, Michael J.; Naworal, John D.; Walker, Kathleen; Connell, Chris T.

2003-11-01

Direct introduction of mainstream cigarette smoke into an inductively coupled plasma mass spectrometry (ICP-MS) has been investigated with respect to its feasibility for on-line analysis of trace elements. An automated apparatus was designed and built interfacing a smoking machine with an ICP-MS for smoke generation, collection, injection and analysis. Major and minor elements present in the particulate phase and the gas phase of mainstream cigarette smoke of 2R4F reference cigarettes have been qualitatively identified by examination of their full mass spectra. This method provides a rapid-screening analysis of the transfer of trace elements into mainstream smoke during cigarette combustion. A full suite of elements present in the whole cigarette smoke has been identified, including As, B, Ba, Br, Cd, Cl, Cs, Cu, Hg, I, K, Li, Mn, Na, Pb, Rb, Sb, Sn, Tl and Zn. Of these elements, the major portions of B, Ba, Cs, Cu, K, Li, Mn, Na, Pb, Rb, Sn, Tl and Zn are present in the particulate phase, whereas the major portion of Hg is present in the gas phase. As, Br, Cd, Cl, I and Sb exist in a distribution between the gas phase and the particulate phase. Depending on the element, the precision of measurement ranges from 5 to 25% in terms of relative standard deviation of peak height and peak area, based on the fourth puff of 2R4F mainstream cigarette smoke analyzed in five smoking replicates.

Contexts of cigarette and e-cigarette use among dual users: a qualitative study.

PubMed

Pokhrel, Pallav; Herzog, Thaddeus A; Muranaka, Nicholas; Regmi, Sakshi; Fagan, Pebbles

2015-09-04

Not much is currently understood regarding the contexts of cigarette and e-cigarette use among dual users. Proper application of e-cigarettes to smoking cessation or tobacco harm reduction would require an understanding of when and why dual users use cigarettes versus e-cigarettes. This study sought to elucidate the contexts of cigarette versus e-cigarette use among dual users. Twelve focus group discussions were conducted with 62 young adult current daily e-cigarette users [63% men; mean age = 25.1 (Standard Deviation = 5.5)]. Almost all participants either concurrently smoked cigarettes or had been recent dual users. Data were analyzed following principles of inductive deduction. Results indicated that dual users' use of cigarettes is influenced by particular activities (e.g., before/after eating), strong craving or need for stimulation (e.g., in response to stress), places/situations (e.g., when cigarette smokers are nearby; outdoors), use of other substances (alcohol, coffee), and unavailability of an e-cigarette when needed. In addition to particular activities and places/situations that are conducive to e-cigarette use, use of e-cigarette when cigarette is not available or where cigarette smoking is not permitted emerged as contexts specific to e-cigarette use. For habitual cigarette smokers wanting to quit tobacco smoking, switching over completely to e-cigarettes may require skills of cognitive-behavioral management. Future research needs to ascertain the characteristics of dual users who use e-cigarettes as cessation aids versus as cigarette alternative when cigarette is unavailable or smoking is not permitted.

Acoustically-Enhanced Direct Contact Vapor Bubble Condensation

NASA Astrophysics Data System (ADS)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2017-11-01

Rate-limited, direct contact vapor condensation of vapor bubbles that are formed by direct steam injection through a nozzle in a quiescent subcooled liquid bath is accelerated using ultrasonic (MHz-range) actuation. A submerged, low power actuator produces an acoustic beam whose radiation pressure deforms the liquid-vapor interface, leading to the formation of a liquid spear that penetrates the vapor bubble to form a vapor torus with a significantly larger surface area and condensation rate. Ultrasonic focusing along the spear leads to the ejection of small, subcooled droplets through the vapor volume that impact the vapor-liquid interface and further enhance the condensation. High-speed Schlieren imaging of the formation and collapse of the vapor bubbles in the absence and presence of actuation shows that the impulse associated with the collapse of the toroidal volume leads to the formation of a turbulent vortex ring in the liquid phase. Liquid motions near the condensing vapor volume are investigated in the absence and presence of acoustic actuation using high-magnification PIV and show the evolution of a liquid jet through the center of the condensing toroidal volume and the formation and advection of vortex ring structures whose impulse appear to increase with temperature difference between the liquid and vapor phases. High-speed image processing is used to assess the effect of the actuation on the temporal and spatial variations in the characteristic scales and condensation rates of the vapor bubbles.

Potentiometric detection of chemical vapors using molecularly imprinted polymers as receptors

PubMed Central

Liang, Rongning; Chen, Lusi; Qin, Wei

2015-01-01

Ion-selective electrode (ISE) based potentiometric gas sensors have shown to be promising analytical tools for detection of chemical vapors. However, such sensors are only capable of detecting those vapors which can be converted into ionic species in solution. This paper describes for the first time a polymer membrane ISE based potentiometric sensing system for sensitive and selective determination of neutral vapors in the gas phase. A molecularly imprinted polymer (MIP) is incorporated into the ISE membrane and used as the receptor for selective adsorption of the analyte vapor from the gas phase into the sensing membrane phase. An indicator ion with a structure similar to that of the vapor molecule is employed to indicate the change in the MIP binding sites in the membrane induced by the molecular recognition of the vapor. The toluene vapor is used as a model and benzoic acid is chosen as its indicator. Coupled to an apparatus manifold for preparation of vapor samples, the proposed ISE can be utilized to determine volatile toluene in the gas phase and allows potentiometric detection down to parts per million levels. This work demonstrates the possibility of developing a general sensing principle for detection of neutral vapors using ISEs. PMID:26215887

Detection of vapor-phase organophosphate threats using wearable conformable integrated epidermal and textile wireless biosensor systems.

PubMed

Mishra, Rupesh K; Martín, Aida; Nakagawa, Tatsuo; Barfidokht, Abbas; Lu, Xialong; Sempionatto, Juliane R; Lyu, Kay Mengjia; Karajic, Aleksandar; Musameh, Mustafa M; Kyratzis, Ilias L; Wang, Joseph

2018-03-15

Flexible epidermal tattoo and textile-based electrochemical biosensors have been developed for vapor-phase detection of organophosphorus (OP) nerve agents. These new wearable sensors, based on stretchable organophosphorus hydrolase (OPH) enzyme electrodes, are coupled with a fully integrated conformal flexible electronic interface that offers rapid and selective square-wave voltammetric detection of OP vapor threats and wireless data transmission to a mobile device. The epidermal tattoo and textile sensors display a good reproducibility (with RSD of 2.5% and 4.2%, respectively), along with good discrimination against potential interferences and linearity over the 90-300mg/L range, with a sensitivity of 10.7µA∙cm 3 ∙mg -1 (R 2 = 0.983) and detection limit of 12mg/L in terms of OP air density. Stress-enduring inks, used for printing the electrode transducers, ensure resilience against mechanical deformations associated with textile and skin-based on-body sensing operations. Theoretical simulations are used to estimate the OP air density over the sensor surface. These fully integrated wearable wireless tattoo and textile-based nerve-agent vapor biosensor systems offer considerable promise for rapid warning regarding personal exposure to OP nerve-agent vapors in variety of decentralized security applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance Testing of the Vapor Phase Catalytic Ammonia Removal Engineering Development Unit

NASA Technical Reports Server (NTRS)

Flynn, Michael; Tleimat, Maher; Nalette, Tim; Quinn, Gregory

2005-01-01

This paper describes the results of performance testing of the Vapor Phase Catalytic Ammonia Removal (VPCAR) technology. The VPCAR technology is currently being developed by NASA as a Mars transit vehicle water recycling system. NASA has recently completed-a grant-to develop a next generation VPCAR system. This grant concluded with the shipment of the final deliverable to NASA on 8/31/03. This paper presents the results of mass, power, volume, and acoustic measurements for the delivered system. Product water purity analysis for a Mars transit mission and a simulated planetary base wastewater ersatz are also provided.

Symptoms during Adolescents' First Use of Cigarettes and E-Cigarettes: A Pilot Study.

PubMed

Chen, May S; Hall, Marissa G; Parada, Humberto; Peebles, Kathryn; Brodar, Kaitlyn E; Brewer, Noel T

2017-10-20

Symptoms adolescents experience during their first time using a cigarette predict their current use, but little is known regarding the symptoms experienced during first e-cigarette use. We conducted a pilot study to understand the symptoms adolescents experience when they first tried cigarettes and e-cigarettes and the associations between these symptoms and current use. Participants were 41 adolescents in two U.S. cities who had tried cigarettes or e-cigarettes. We asked adolescents to recall the symptoms they experienced during their first cigarette or e-cigarette and categorized symptoms as negative (felt bad, coughing/chest pain, bad taste, upset stomach, dizzy/lightheaded) or positive (felt relaxed, rush/buzz). Adolescents reported fewer negative symptoms for first e-cigarette than first cigarette use (all p < 0.05). Current cigarette smoking was associated with endorsing fewer negative symptoms (OR = 0.49, 95% CI = [0.25, 0.95]) and more positive symptoms (OR = 7.11, 95% CI = [1.47, 34.33]) at first cigarette use. First e-cigarette use symptoms were not associated with current e-cigarette use. Adolescents reported fewer negative symptoms from first e-cigarette than from first cigarette, and e-cigarette symptoms did not influence use as they do for cigarettes. Additional research is needed to confirm these findings in longitudinal studies.

Improving biomass pyrolysis economics by integrating vapor and liquid phase upgrading

DOE PAGES

Iisa, Kristiina; Robichaud, David J.; Watson, Michael J.; ...

2017-11-24

Partial deoxygenation of bio-oil by catalytic fast pyrolysis with subsequent coupling and hydrotreating can lead to improved economics and will aid commercial deployment of pyrolytic conversion of biomass technologies. Biomass pyrolysis efficiently depolymerizes and deconstructs solid plant matter into carbonaceous molecules that, upon catalytic upgrading, can be used for fuels and chemicals. Upgrading strategies include catalytic deoxygenation of the vapors before they are condensed (in situ and ex situ catalytic fast pyrolysis), or hydrotreating following condensation of the bio-oil. In general, deoxygenation carbon efficiencies, one of the most important cost drivers, are typically higher for hydrotreating when compared to catalyticmore » fast pyrolysis alone. However, using catalytic fast pyrolysis as the primary conversion step can benefit the entire process chain by: (1) reducing the reactivity of the bio-oil, thereby mitigating issues with aging and transport and eliminating need for multi-stage hydroprocessing configurations; (2) producing a bio-oil that can be fractionated through distillation, which could lead to more efficient use of hydrogen during hydrotreating and facilitate integration in existing petroleum refineries; and (3) allowing for the separation of the aqueous phase. In this perspective, we investigate in detail a combination of these approaches, where some oxygen is removed during catalytic fast pyrolysis and the remainder removed by downstream hydrotreating, accompanied by carbon–carbon coupling reactions in either the vapor or liquid phase to maximize carbon efficiency toward value-driven products (e.g. fuels or chemicals). The economic impact of partial deoxygenation by catalytic fast pyrolysis will be explored in the context of an integrated two-stage process. In conclusion, improving the overall pyrolysis-based biorefinery economics by inclusion of production of high-value co-products will be examined.« less

Improving biomass pyrolysis economics by integrating vapor and liquid phase upgrading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iisa, Kristiina; Robichaud, David J.; Watson, Michael J.

Partial deoxygenation of bio-oil by catalytic fast pyrolysis with subsequent coupling and hydrotreating can lead to improved economics and will aid commercial deployment of pyrolytic conversion of biomass technologies. Biomass pyrolysis efficiently depolymerizes and deconstructs solid plant matter into carbonaceous molecules that, upon catalytic upgrading, can be used for fuels and chemicals. Upgrading strategies include catalytic deoxygenation of the vapors before they are condensed (in situ and ex situ catalytic fast pyrolysis), or hydrotreating following condensation of the bio-oil. In general, deoxygenation carbon efficiencies, one of the most important cost drivers, are typically higher for hydrotreating when compared to catalyticmore » fast pyrolysis alone. However, using catalytic fast pyrolysis as the primary conversion step can benefit the entire process chain by: (1) reducing the reactivity of the bio-oil, thereby mitigating issues with aging and transport and eliminating need for multi-stage hydroprocessing configurations; (2) producing a bio-oil that can be fractionated through distillation, which could lead to more efficient use of hydrogen during hydrotreating and facilitate integration in existing petroleum refineries; and (3) allowing for the separation of the aqueous phase. In this perspective, we investigate in detail a combination of these approaches, where some oxygen is removed during catalytic fast pyrolysis and the remainder removed by downstream hydrotreating, accompanied by carbon–carbon coupling reactions in either the vapor or liquid phase to maximize carbon efficiency toward value-driven products (e.g. fuels or chemicals). The economic impact of partial deoxygenation by catalytic fast pyrolysis will be explored in the context of an integrated two-stage process. In conclusion, improving the overall pyrolysis-based biorefinery economics by inclusion of production of high-value co-products will be examined.« less

Passive exposure to electronic cigarette (e-cigarette) use increases desire for combustible and e-cigarettes in young adult smokers

PubMed Central

King, Andrea C; Smith, Lia J; McNamara, Patrick J; Matthews, Alicia K; Fridberg, Daniel J

2016-01-01

Background Passive exposure to combustible cigarette use has been shown to act as a cue to increase smoking urge. Given the resemblance of e-cigarettes and other electronic nicotine delivery systems (ENDS) to combustible cigarettes, we examined whether these devices could also act as a cue to increase smoking desire and urges in those passively exposed. Methods Young adult daily smokers (age 18–35 years; N=60) completed subjective ratings before and after exposure to a study confederate drinking bottled water (control cue) and then smoking either a combustible or e-cigarette (active cue). Smoking desire and urge ratings were measured with visual analogue scale items for desire for a regular and an e-cigarette and the Brief Questionnaire of Smoking Urges. Results Passive exposure to both the e-cigarette and combustible cigarette cue significantly increased observers’ ratings of desire and urge to smoke a regular cigarette (all ps<0.05). Exposure to the e-cigarette cue but not the regular cigarette cue also increased desire to smoke an e-cigarette (p<0.01). Conclusions The results provide the first evidence in a controlled setting that electronic cigarette exposure may evoke smoking urges in young adult daily smokers. With replication, these findings may have relevance for ENDS regulation and policy. PMID:24848637

On the synthesis of AlPO4-21 molecular sieve by vapor phase transport method and its phase transformation to AlPO4-15 molecular sieve

NASA Astrophysics Data System (ADS)

Shao, Hui; Chen, Jingjing; Chen, Xia; Leng, Yixin; Zhong, Jing

2015-04-01

An experimental design was applied to the synthesis of AlPO4-21 molecular sieve (AWO structure) by vapor phase transport (VPT) method, using tetramethylguanidine (TMG) as the template. In this study, the effects of crystallization time, crystallization temperature, phosphor content, template content and water content in the synthesis gel were investigated. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy and fourier transform infrared spectroscopy (FT-IR). Microstructural analysis of the crystal growth in vapor synthetic conditions revealed a revised crystal growth route from zeolite AlPO4-21 to AlPO4-15 in the presence of the TMG. Homogenous hexagonal prism AlPO4-21 crystals with size of 7 × 3 μm were synthesized at a lower temperature (120 °C), which were completely different from the typical tabular parallelogram crystallization microstructure of AlPO4-21 phase. The crystals were transformed into AlPO4-21 phase with higher crystallization temperature, longer crystallization time, higher P2O5/Al2O3 ratio and higher TMG/Al2O3 ratio.

Point-of-Sale Cigarette Marketing, Urge to Buy Cigarettes, and Impulse Purchases of Cigarettes: Results From a Population-Based Survey.

PubMed

Siahpush, Mohammad; Shaikh, Raees A; Hyland, Andrew; Smith, Danielle; Sikora Kessler, Asia; Meza, Jane; Wan, Neng; Wakefield, Melanie

2016-05-01

Our aim was to examine the association of exposure to point-of-sale (POS) cigarette marketing for one's regular brand, as well as any brand of cigarettes, with the urge to buy cigarettes and frequency of impulse purchases of cigarettes. Nine hundred ninety-nine smokers in Omaha, Nebraska were interviewed via telephone. Cigarette marketing was measured by asking respondents questions about noticing pack displays, advertisements, and promotions such as discounts for their regular brand as well as any brand of cigarettes in their neighborhoods stores. We measured urge to buy cigarettes with the question "When you are in a store in your neighborhood that sells tobacco products, how often do you get an urge to buy cigarettes?" We measured frequency of impulse purchases of cigarettes with the question "When you are shopping in a store in your neighborhood for something other than cigarettes, how often do you decide to buy cigarettes?" We estimated ordinary least squares linear regression models to address the study aim. Higher levels of POS marketing for one's regular brand and any brands of cigarettes were associated with more frequent urges to buy (P < .001 and P < .001, respectively) and impulse purchases of cigarettes (P = .01 and P = .013, respectively), after adjusting for covariates. Exposure to POS marketing for one's own brand of cigarette as well as any brand is associated with urges to buy and impulse purchases of cigarettes. Existing studies on the association of POS cigarette marketing with urge to buy and an impulse purchase of cigarettes only focus on cigarette pack displays, not on advertisements and promotions. Also, these studies make no distinction between marketing for the smokers' regular brand and any brand of cigarettes. This study found that Exposure to POS marketing for one's own brand of cigarette as well as any brand is associated with urges to buy and impulse purchases of cigarettes. Our findings can provide part of the evidence-base needed by

Phase degradation in BxGa1-xN films grown at low temperature by metalorganic vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Gunning, Brendan P.; Moseley, Michael W.; Koleske, Daniel D.; Allerman, Andrew A.; Lee, Stephen R.

2017-04-01

Using metalorganic vapor phase epitaxy, a comprehensive study of BxGa1-xN growth on GaN and AlN templates is described. BGaN growth at high-temperature and high-pressure results in rough surfaces and poor boron incorporation efficiency, while growth at low-temperature and low-pressure (750-900 °C and 20 Torr) using nitrogen carrier gas results in improved surface morphology and boron incorporation up to 7.4% as determined by nuclear reaction analysis. However, further structural analysis by transmission electron microscopy and x-ray pole figures points to severe degradation of the high boron composition films, into a twinned cubic structure with a high density of stacking faults and little or no room temperature photoluminescence emission. Films with <1% triethylboron (TEB) flow show more intense, narrower x-ray diffraction peaks, near-band-edge photoluminescence emission at 362 nm, and primarily wurtzite-phase structure in the x-ray pole figures. For films with >1% TEB flow, the crystal structure becomes dominated by the cubic phase. Only when the TEB flow is zero (pure GaN), does the cubic phase entirely disappear from the x-ray pole figure, suggesting that under these growth conditions even very low boron compositions lead to mixed crystalline phases.

The electronic cigarette: the new cigarette of the 21st century?

PubMed

Knorst, Marli Maria; Benedetto, Igor Gorski; Hoffmeister, Mariana Costa; Gazzana, Marcelo Basso

2014-10-01

The electronic nicotine delivery system, also known as the electronic cigarette, is generating considerable controversy, not only in the general population but also among health professionals. Smokers the world over have been increasingly using electronic cigarettes as an aid to smoking cessation and as a substitute for conventional cigarettes. There are few available data regarding the safety of electronic cigarettes. There is as yet no evidence that electronic cigarettes are effective in treating nicotine addiction. Some smokers have reported using electronic cigarettes for over a year, often combined with conventional cigarettes, thus prolonging nicotine addiction. In addition, the increasing use of electronic cigarettes by adolescents is a cause for concern. The objective of this study was to describe electronic cigarettes and their components, as well as to review the literature regarding their safety; their impact on smoking initiation and smoking cessation; and regulatory issues related to their use.

The electronic cigarette: the new cigarette of the 21st century?*

PubMed Central

Knorst, Marli Maria; Benedetto, Igor Gorski; Hoffmeister, Mariana Costa; Gazzana, Marcelo Basso

2014-01-01

The electronic nicotine delivery system, also known as the electronic cigarette, is generating considerable controversy, not only in the general population but also among health professionals. Smokers the world over have been increasingly using electronic cigarettes as an aid to smoking cessation and as a substitute for conventional cigarettes. There are few available data regarding the safety of electronic cigarettes. There is as yet no evidence that electronic cigarettes are effective in treating nicotine addiction. Some smokers have reported using electronic cigarettes for over a year, often combined with conventional cigarettes, thus prolonging nicotine addiction. In addition, the increasing use of electronic cigarettes by adolescents is a cause for concern. The objective of this study was to describe electronic cigarettes and their components, as well as to review the literature regarding their safety; their impact on smoking initiation and smoking cessation; and regulatory issues related to their use. PMID:25410845

A semi-empirical model for the complete orientation dependence of the growth rate for vapor phase epitaxy - Chloride VPE of GaAs

NASA Technical Reports Server (NTRS)

Seidel-Salinas, L. K.; Jones, S. H.; Duva, J. M.

1992-01-01

A semi-empirical model has been developed to determine the complete crystallographic orientation dependence of the growth rate for vapor phase epitaxy (VPE). Previous researchers have been able to determine this dependence for a limited range of orientations; however, our model yields relative growth rate information for any orientation. This model for diamond and zincblende structure materials is based on experimental growth rate data, gas phase diffusion, and surface reactions. Data for GaAs chloride VPE is used to illustrate the model. The resulting growth rate polar diagrams are used in conjunction with Wulff constructions to simulate epitaxial layer shapes as grown on patterned substrates. In general, this model can be applied to a variety of materials and vapor phase epitaxy systems.

Electronic Cigarette Toxicity.

PubMed

Payne, J Drew; Michaels, David; Orellana-Barrios, Menfil; Nugent, Kenneth

2017-04-01

Electronic cigarettes (e-cigarettes) are often advertised as a healthier product when compared with traditional cigarettes. Currently, there are limited data to support this and only a threat of federal regulation from the US Food and Drug Administration. Calls to poison control centers about e-cigarette toxicity, especially in children, and case reports of toxic exposures have increased over the past 3 years. This research letter reports the frequency of hazardous exposures to e-cigarettes and characterizes the reported adverse health effects associated with e-cigarette toxicity.

[E-cigarette use in university students and its relationship to cigarette smoking].

PubMed

Rakotozandry, T; Stenger, N; Burel, C; Penna, L; Ramadour, M; Disdier, P; Charpin, D

2016-03-01

There is concern that e-cigarette use could be a risk factor for subsequent cigarette smoking. This survey included a group of 1220 students at Aix-Marseille University who attended a check-up visit and volunteered to participate to the survey. They answered a standardized questionnaire relating to e-cigarette use, smoking habits and the relationship between both habits. Mean age of participants was 19.9 years and 56% of them were female. All students invited to the check-up examination attended and agreed to participate in the survey. 13.3% of students answered they had already used e-cigarettes, a higher proportion of boys (17.5%) than girls (10.0%), starting at a mean age equal to 19.2 years. Forty-six percent of them had already smoked cigarettes, more girls (55.0%) than boys (45.0%). Among current cigarette smokers, e-cigarette use had induced giving up smoking in 12.6% and a decrease in the number of cigarettes smoked in 30.1%. Twenty percent said they begun to smoke cigarettes after using e-cigarettes. E-cigarette use is much less prevalent than smoking conventional tobacco cigarettes. There is a strong link between both. E-cigarette use had allowed a cessation or reduction in tobacco smoking in half of users. E-cigarette users may go on to start tobacco smoking but prospective surveys are needed to know how this will evolve over time. E-cigarette use could also be a means to prevent or postpone cigarette smoking. Copyright © 2015 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Cigarette Cue Attentional Bias in Cocaine-Smoking and Non-Cocaine-Using Cigarette Smokers.

PubMed

Marks, Katherine R; Alcorn, Joseph L; Stoops, William W; Rush, Craig R

2016-09-01

Cigarette smoking in cocaine users is nearly four times higher than the national prevalence and cocaine use increases cigarette smoking. The mechanisms underlying cigarette smoking in cocaine-using individuals need to be identified to promote cigarette and cocaine abstinence. Previous studies have examined the salience of cigarette and cocaine cues separately. The present aim was to determine whether cigarette attentional bias (AB) is higher in cigarettes smokers who smoke cocaine relative to individuals who only smoke cigarettes. Twenty cigarette smokers who smoke cocaine and 20 non-cocaine-using cigarette smokers completed a visual probe task with eye-tracking technology. During this task, the magnitude of cigarette and cocaine AB was assessed through orienting bias, fixation time, and response time. Cocaine users displayed an orienting bias towards cigarette cues. Cocaine users also endorsed a more urgent desire to smoke to relieve negative affect associated with cigarette craving than non-cocaine users (g = 0.6). Neither group displayed a cigarette AB, as measured by fixation time. Cocaine users, but not non-cocaine users, displayed a cocaine AB as measured by orienting bias (g = 2.0) and fixation time (g = 1.2). There were no significant effects for response time data. Cocaine-smoking cigarettes smokers display an initial orienting bias toward cigarette cues, but not sustained cigarette AB. The incentive motivation underlying cigarette smoking also differs. Cocaine smokers report more urgent desire to smoke to relieve negative affect. Identifying differences in motivation to smoke cigarettes may provide new treatment targets for cigarette and cocaine use disorders. These results suggest that cocaine-smoking cigarette smokers display an initial orienting bias towards cigarette cues, but not sustained attention towards cigarette cues, relative to non-cocaine-using smokers. Smoked cocaine users also report a more urgent desire to smoke to relieve negative affect

Vapor deposition routes to conformal polymer thin films

PubMed Central

Moni, Priya; Al-Obeidi, Ahmed

2017-01-01

Vapor phase syntheses, including parylene chemical vapor deposition (CVD) and initiated CVD, enable the deposition of conformal polymer thin films to benefit a diverse array of applications. This short review for nanotechnologists, including those new to vapor deposition methods, covers the basic theory in designing a conformal polymer film vapor deposition, sample preparation and imaging techniques to assess film conformality, and several applications that have benefited from vapor deposited, conformal polymer thin films. PMID:28487816

Changes in use of cigarettes and non-cigarette alternative products among college students.

PubMed

Loukas, Alexandra; Batanova, Milena; Fernandez, Alejandra; Agarwal, Deepti

2015-10-01

The present study examined change in use of various smoked and smokeless non-cigarette alternative products in a sample of college students, stratified by current, or past 30-day, cigarette smoking status. Participants were 698 students from seven four-year colleges in Texas. Participants completed two waves of online surveys regarding tobacco use, knowledge, and attitudes, with 14 months between each wave. The most prevalent products used by the entire sample at Wave 1 were cigarettes, followed by hookah, cigars/cigarillos/little cigars, and electronic cigarettes (e-cigarettes). At Wave 2, prevalence of e-cigarette use surpassed use of cigars/cigarillos/little cigars. Snus and chew/snuff/dip were relatively uncommon at both waves. Examination of change in use indicated that e-cigarette use increased across time among both current cigarette smokers and non-cigarette smokers. Prevalence of current e-cigarette use doubled across the 14-month period to 25% among current smokers and tripled to 3% among non-cigarette smokers. Hookah use also increased across time, but only among non-cigarette smokers, whereas it decreased among current cigarette smokers. Use of all other non-cigarette alternatives remained unchanged across time. Logistic regression analysis was used to examine the socio-demographic predictors of Wave 2 e-cigarette use, the only product that increased in use among both current cigarette smokers and non-cigarette smokers. Results indicated that Wave 1 current cigarette use and Wave 1 current e-cigarette use, but not gender, age, or race/ethnicity, were significantly associated with Wave 2 e-cigarette use. Findings underscore the need to track changes in the use of non-cigarette alternatives and call for additional research examining the factors contributing to change in use. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemistry of vaporization of refractory materials

NASA Technical Reports Server (NTRS)

Gilles, P. W.

1975-01-01

A discussion is given of the principles of physical chemistry important in vaporization studies, notably the concepts of equilibrium, phase behavior, thermodynamics, solid solution, and kinetics. The important factors influencing equilibrium vaporization phenomena are discussed and illustrated. A proper course of a vaporization study consisting of 9 stages is proposed. The important experimental techniques of Knudsen effusion, Langmuir vaporization and mass spectrometry are discussed. The principles, the factors, the course of a study and the experimental techniques and procedures are illustrated by recent work on the Ti-O system.

Stability limit of liquid water in metastable equilibrium with subsaturated vapors.

PubMed

Wheeler, Tobias D; Stroock, Abraham D

2009-07-07

A pure liquid can reach metastable equilibrium with its subsaturated vapor across an appropriate membrane. This situation is analogous to osmotic equilibrium: the reduced chemical potential of the dilute phase (the subsaturated vapor) is compensated by a difference in pressure between the phases. To equilibrate with subsaturated vapor, the liquid phase assumes a pressure that is lower than its standard vapor pressure, such that the liquid phase is metastable with respect to the vapor phase. For sufficiently subsaturated vapors, the liquid phase can even assume negative pressures. The appropriate membrane for this metastable equilibrium must provide the necessary mechanical support to sustain the difference in pressure between the two phases, limit nonhomogeneous mechanisms of cavitation, and resist the entry of the dilutant (gases) into the pure phase (liquid). In this article, we present a study of the limit of stability of liquid water--the degree of subsaturation at which the liquid cavitates--in this metastable state within microscale voids embedded in hydrogel membranes. We refer to these structures as vapor-coupled voids (VCVs). In these VCVs, we observed that liquid water cavitated when placed in equilibrium with vapors of activity aw,vapairvapor nuclei, and (iv

An Analysis of Electronic Cigarette and Cigarette Advertising in US Women's Magazines.

PubMed

Basch, Corey Hannah; Mongiovi, Jennifer; Hillyer, Grace Clarke; Ethan, Danna; Hammond, Rodney

2016-01-01

Traditional cigarette advertising has existed in the US for over 200 years. Studies suggest that advertising has an impact on the initiation and maintenance of smoking behaviors. In recent years, electronic cigarettes (e-cigarettes) emerged on the market as an alternative to the traditional tobacco cigarette. The purpose of this study was to describe advertisements in popular US magazines marketed to women for cigarettes and e-cigarettes. This study involved analyzing 99 issues of 14 popular US magazines marketed to women. Compared to advertisements for traditional cigarettes, advertisements for e-cigarettes were more often found in magazines geared toward the 31-40-year-old audience (76.5% vs. 53.1%, P = 0.011) whereas traditional cigarette advertisements were nearly equally distributed among women 31-40 and ≥40 years. More than three-quarters of the e-cigarette advertisements presented in magazines aimed at the higher median income households compared to a balanced distribution by income for traditional cigarettes (P = 0.033). Future studies should focus on specific marketing tactics used to promote e-cigarette use as this product increases in popularity, especially among young women smokers.

Perceptions of the Relative Harm of Cigarettes and E-cigarettes Among U.S. Youth

PubMed Central

Ambrose, Bridget K.; Rostron, Brian L.; Johnson, Sarah E.; Portnoy, David B.; Apelberg, Benjamin J.; Kaufman, Annette R.; Choiniere, Conrad J.

2015-01-01

Background Despite progress in reducing youth smoking, adolescents remain highly susceptible to tobacco use. Of concern is whether youth perceive electronic cigarettes (e-cigarettes) as a preferable alternative to conventional cigarettes. Purpose To describe cigarette harm perception patterns among youth based on the frequency and intensity of cigarette smoking, and examine the relative harm perceptions of conventional versus e-cigarettes, using data from a large, nationally representative sample of U.S. youth. Methods Data from the 2012 National Youth Tobacco Survey (N=24,658) were analyzed in 2013 to identify patterns of cigarette harm perceptions. Multinomial logistic regression was conducted to identify associations between demographic and tobacco use characteristics and cigarette harm perception patterns. Logistic regression was conducted to examine the relationship between cigarette harm perceptions and the perception of e-cigarettes as less harmful than cigarettes for current, ever, and never cigarette smokers. Results The majority of youth (64.2%) perceived the harmfulness of cigarettes as dose-dependent. Approximately one in three students perceived e-cigarettes as less harmful than conventional cigarettes. Regardless of cigarette smoking status, ever users of e-cigarettes and those with “dose-dependent” cigarette harm perceptions consistently were more likely to perceive e-cigarettes as less harmful than conventional cigarettes. Conclusions Many youth perceive tobacco use on a continuum of harm. Youth who perceive gradations in harm—both by frequency and intensity of cigarette use and by type of product—may be particularly susceptible to e-cigarette use. PMID:25044196

Liquid chromatographic determination of benzo(a)pyrene in total particulate matter of cigarette smoke

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomkins, B.A.; Jenkins, R.A.; Griest, W.H.

The benzo(a)pyrene (BaP) delivery of reference and commercially available tobacco cigarettes, as well as reference and placebo marijuana cigarettes, is determined using a sequential liquid chromatographic/liquid chromatographic procedure. The total particulate matter of sample cigarette smoke is collected using a Cambridge filter pad, which is ultrasonically extracted with acetone. The resulting extract is filtered, then fractionated using semipreparative-scale normal phase liquid chromatography (LC). Quantitative determination is achieved using analytical-scale reverse phase LC equipped with a fluorescence detector. The method is precise (+/- 10-15% relative standard deviation) and yields 85% or better BaP recovery at the ng/cig. level. A single padmore » may be analyzed in 8 person-hours, while a more typical lot of 12 pads (6 pads each for 2 cigarette brands) may be analyzed in 10 person-days.« less

E-cigarette use and subsequent cigarette and marijuana use among Hispanic young adults.

PubMed

Unger, Jennifer B; Soto, Daniel W; Leventhal, Adam

2016-06-01

Electronic cigarettes (e-cigarettes) could have a multifaceted effect on public health by changing the likelihood that: (a) non-smokers and non-users of marijuana subsequently transition to cigarette and marijuana use, respectively, and/or: (b) cigarette smokers subsequently quit smoking. We analyzed data from a longitudinal study of Hispanic young adults in Los Angeles, California to determine whether e-cigarette use is associated with subsequent cigarette or marijuana use over a one-year period. Survey data were collected from 1332 Hispanic young adults (59% female, mean age=22.7 years, SD=0.39 years) in 2014 and 2015. Logistic regression analyses examined the association between e-cigarette use in 2014 and cigarette/marijuana use in 2015, controlling for age, sex, and other substance use. In 2014, prevalence of past-month use was 9% for e-cigarettes, 21% for cigarettes, and 23% for marijuana. Among past-month cigarette nonsmokers in 2014, those who were past-month e-cigarette users in 2014 were over 3 times more likely to be past-month cigarette smokers in 2015, compared with those who did not report past-month e-cigarette use in 2014 (26% vs. 7%; OR=3.32, 95% CI=1.55, 7.10). Among past-month marijuana non-users in 2014, those who were past-month e-cigarette users in 2014 were nearly 2 times more likely to be past-month marijuana users in 2015 (24% vs. 12%;OR=1.97, 95% CI=1.01, 3.86). Among past-month cigarette and marijuana users in 2014, e-cigarette use in 2014 was not associated with a change cigarette and marijuana use, respectively, in 2015. Among Hispanic young adults, e-cigarettes could increase the likelihood of transitioning from non-user to user of cigarettes or marijuana and was not associated with smoking cessation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Passive exposure to electronic cigarette (e-cigarette) use increases desire for combustible and e-cigarettes in young adult smokers.

PubMed

King, Andrea C; Smith, Lia J; McNamara, Patrick J; Matthews, Alicia K; Fridberg, Daniel J

2015-09-01

Passive exposure to combustible cigarette use has been shown to act as a cue to increase smoking urge. Given the resemblance of e-cigarettes and other electronic nicotine delivery systems (ENDS) to combustible cigarettes, we examined whether these devices could also act as a cue to increase smoking desire and urges in those passively exposed. Young adult daily smokers (age 18-35 years; N=60) completed subjective ratings before and after exposure to a study confederate drinking bottled water (control cue) and then smoking either a combustible or e-cigarette (active cue). Smoking desire and urge ratings were measured with visual analogue scale items for desire for a regular and an e-cigarette and the Brief Questionnaire of Smoking Urges. Passive exposure to both the e-cigarette and combustible cigarette cue significantly increased observers' ratings of desire and urge to smoke a regular cigarette (all ps<0.05). Exposure to the e-cigarette cue but not the regular cigarette cue also increased desire to smoke an e-cigarette (p<0.01). The results provide the first evidence in a controlled setting that electronic cigarette exposure may evoke smoking urges in young adult daily smokers. With replication, these findings may have relevance for ENDS regulation and policy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

An examination of the effect on cigarette prices and promotions of Philip Morris USA penalties to stores that sell cigarettes to minors.

PubMed

Feighery, E C; Schleicher, N C; Ribisl, K M; Rogers, T

2009-12-01

The purpose of this study was to assess the potential impact of public policies to regulate price discounting strategies on retail cigarette prices and advertising. Philip Morris USA (PM USA) has a policy designed to sanction stores violating state laws banning illegal tobacco sales to minors by temporarily suspending price discounting incentives. This study examined the impact of those sanctions on retail cigarette prices and sales promotion advertising. In November 2006, the California Attorney General's Office informed PM USA that 196 stores were found guilty of illegal underage sales. Of these, 109 stores that participated in the PM USA Retail Leaders Program were notified that their merchandising and/or promotional resources would be suspended for the month of April 2007. The remaining 87 stores were not sanctioned and served as a comparison group. Trained raters assessed advertising and prices of selected PM USA brands in these stores pre-penalty and during the penalty phase. There were no significant differences between sanctioned and non-sanctioned stores on median changes in price and sales promotion advertising from the pre-penalty to the penalty phase. The lack of impact on cigarette prices and advertising indicate that the PM USA policy may be flawed in its design or execution. If public policies are developed to restrain cigarette price discounting strategies, they should be crafted to ensure compliance and preclude possible compensatory actions by retailers.

Characteristics of Adults Who Switched From Cigarette Smoking to E-cigarettes.

PubMed

Park, Su Hyun; Duncan, Dustin T; Shahawy, Omar El; Lee, Lily; Shearston, Jenni A; Tamura, Kosuke; Sherman, Scott E; Weitzman, Michael

2017-11-01

Because of the rapidly increasing use of electronic cigarettes (e-cigarettes), this study aimed to investigate the individual characteristics and state-level prevalence of U.S. adults who have switched to e-cigarettes from traditional cigarettes. Data from the 2012-2013 and 2013-2014 National Adult Tobacco Surveys were analyzed in 2016. Relative percent change in switching was estimated, and the state-specific prevalence of adults who switched to e-cigarettes from traditional cigarettes was calculated and mapped. Multivariate logistic regression was conducted to examine how switching varied by sociodemographic subgroups and region. Overall, the number of individuals who switched from traditional cigarettes to e-cigarettes increased by approximately 100% over the 1-year interval. Significant increases were found among a number of sociodemographics and regions. Multivariate logistic regression analyses showed that young adults and those living in the South and West were more likely to switch to e-cigarettes, compared to former smokers who did not switch. Compared with current dual users, those with higher education and those who were not single were more likely to switch to e-cigarettes. The state with the highest prevalence of switching was New Mexico (7.3%), whereas Connecticut had the lowest prevalence (0.8 %) among former smokers. There is an increase in the progression from traditional cigarette use to e-cigarette use. Further research is warranted to determine whether this change continues and facilitates cigarette smoking cessation as a possible public health benefit and opportunity to save lives rather than constitutes a potential threat to public health. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Waterpipes and e-cigarettes: Impact of alternative smoking techniques on indoor air quality and health

NASA Astrophysics Data System (ADS)

Fromme, Hermann; Schober, Wolfgang

2015-04-01

Waterpipe (WP) smoking is growing as an alternative to cigarette smoking, especially in younger age groups. E-cigarette use has also increased in recent years. A majority of smokers mistakenly believe that WP smoking is a social entertainment practice that leads to more social behavior and relaxation and that this type of smoking is safe or less harmful and less addictive than cigarette smoking. In reality, WP smokers are exposed to hundreds of toxic substances that include known carcinogens. High exposures to carbon monoxide and nicotine are major health threats. Persons exposed to secondhand WP smoke are also at risk. There is growing evidence that WP smoke causes adverse effects on the pulmonary and cardiovascular systems and is responsible for cancer. E-cigarettes are marketed as a smokeless and safe way to inhale nicotine without being exposed to the many toxic components of tobacco cigarettes, and as an aid to smoking cessation. In fact, consumers (vapers) and secondhand vapers can be exposed to substantial amounts of VOC, PAH or other potentially harmful substances. Of major health concern is the inhalation of fine and ultrafine particles formed from supersaturated 1,2-propanediol vapor. Such particles can be deposited in the deeper parts of the lung and may harm the respiratory system or increase the risk of acquiring asthma. More research on the safety of e-cigarettes needs to be conducted to ensure a high level of public health protection in the long-term.

Vapor-phase concentrations of PAHs and their derivatives determined in a large city: correlations with their atmospheric aerosol concentrations.

PubMed

Barrado, Ana Isabel; García, Susana; Sevillano, Marisa Luisa; Rodríguez, Jose Antonio; Barrado, Enrique

2013-11-01

Thirteen PAHs, five nitro-PAHs and two hydroxy-PAHs were determined in 55 vapor-phase samples collected in a suburban area of a large city (Madrid, Spain), from January 2008 to February 2009. The data obtained revealed correlations between the concentrations of these compounds and a series of meteorological factors (e.g., temperature, atmospheric pressure) and physical-chemical factors (e.g., nitrogen and sulfur oxides). As a consequence, seasonal trends were observed in the atmospheric pollutants. A "mean sample" for the 14-month period would contain a total PAH concentration of 13835±1625 pg m(-3) and 122±17 pg m(-3) of nitro-PAHs. When the data were stratified by season, it emerged that a representative sample of the coldest months would contain 18900±2140 pg m(-3) of PAHs and 150±97 pg m(-3) of nitro-PAHs, while in an average sample collected in the warmest months, these values drop to 9293±1178 pg m(-3) for the PAHs and to 97±13 pg m(-3) for the nitro-PAHs. Total vapor phase concentrations of PAHs were one order of magnitude higher than concentrations detected in atmospheric aerosol samples collected on the same dates. Total nitro-PAH concentrations were comparable to their aerosol concentrations whereas vapor phase OH-PAHs were below their limits of the detection, indicating these were trapped in airborne particles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Flexible, Low-Power Thin-Film Transistors Made of Vapor-Phase Synthesized High-k, Ultrathin Polymer Gate Dielectrics.

PubMed

Choi, Junhwan; Joo, Munkyu; Seong, Hyejeong; Pak, Kwanyong; Park, Hongkeun; Park, Chan Woo; Im, Sung Gap

2017-06-21

A series of high-k, ultrathin copolymer gate dielectrics were synthesized from 2-cyanoethyl acrylate (CEA) and di(ethylene glycol) divinyl ether (DEGDVE) monomers by a free radical polymerization via a one-step, vapor-phase, initiated chemical vapor deposition (iCVD) method. The chemical composition of the copolymers was systematically optimized by tuning the input ratio of the vaporized CEA and DEGDVE monomers to achieve a high dielectric constant (k) as well as excellent dielectric strength. Interestingly, DEGDVE was nonhomopolymerizable but it was able to form a copolymer with other kinds of monomers. Utilizing this interesting property of the DEGDVE cross-linker, the dielectric constant of the copolymer film could be maximized with minimum incorporation of the cross-linker moiety. To our knowledge, this is the first report on the synthesis of a cyanide-containing polymer in the vapor phase, where a high-purity polymer film with a maximized dielectric constant was achieved. The dielectric film with the optimized composition showed a dielectric constant greater than 6 and extremely low leakage current densities (<3 × 10 -8 A/cm 2 in the range of ±2 MV/cm), with a thickness of only 20 nm, which is an outstanding thickness for down-scalable cyanide polymer dielectrics. With this high-k dielectric layer, organic thin-film transistors (OTFTs) and oxide TFTs were fabricated, which showed hysteresis-free transfer characteristics with an operating voltage of less than 3 V. Furthermore, the flexible OTFTs retained their low gate leakage current and ideal TFT characteristics even under 2% applied tensile strain, which makes them some of the most flexible OTFTs reported to date. We believe that these ultrathin, high-k organic dielectric films with excellent mechanical flexibility will play a crucial role in future soft electronics.

An evaluation of the vapor phase catalytic ammonia removal process for use in a Mars transit vehicle.

PubMed

Flynn, M; Borchers, B

1998-01-01

This article describes the design specification of the Vapor Phase Catalytic Ammonia Removal (VPCAR) process and the relative benefits of its utilization in a Mars Transit Vehicle application. The VPCAR process is a wastewater treatment technology that combines distillation with high-temperature catalytic oxidation of volatile impurities such as ammonia and organic compounds.

How do minimum cigarette price laws affect cigarette prices at the retail level?

PubMed

Feighery, E C; Ribisl, K M; Schleicher, N C; Zellers, L; Wellington, N

2005-04-01

Half of US states have minimum cigarette price laws that were originally passed to protect small independent retailers from unfair price competition with larger retailers. These laws prohibit cigarettes from being sold below a minimum price that is set by a formula. Many of these laws allow cigarette company promotional incentives offered to retailers, such as buydowns and master-type programmes, to be calculated into the formula. Allowing this provision has the potential to lower the allowable minimum price. This study assesses whether stores in states with minimum price laws have higher cigarette prices and lower rates of retailer participation in cigarette company promotional incentive programmes. Retail cigarette prices and retailer participation in cigarette company incentive programmes in 2001 were compared in eight states with minimum price laws and seven states without them. New York State had the most stringent minimum price law at the time of the study because it excluded promotional incentive programmes in its price setting formula; cigarette prices in New York were compared to all other states included in the study. Cigarette prices were not significantly different in our sample of US states with and without cigarette minimum price laws. Cigarette prices were significantly higher in New York stores than in the 14 other states combined. Most existing minimum cigarette price laws appear to have little impact on the retail price of cigarettes. This may be because they allow the use of promotional programmes, which are used by manufacturers to reduce cigarette prices. New York's strategy to disallow these types of incentive programmes may result in higher minimum cigarette prices, and should also be explored as a potential policy strategy to control cigarette company marketing practices in stores. Strict cigarette minimum price laws may have the potential to reduce cigarette consumption by decreasing demand through increased cigarette prices and reduced

Penicillium expansum Inhibition on Bread by Lemongrass Essential Oil in Vapor Phase.

PubMed

Mani López, Emma; Valle Vargas, Georgina P; Palou, Enrique; López Malo, Aurelio

2018-02-23

The antimicrobial activity of lemongrass ( Cymbopogon citratus) essential oil (EO) in the vapor phase on the growth of Penicillium expansum inoculated on bread was evaluated, followed by a sensory evaluation of the bread's attributes after EO exposure. The lemongrass EO was extracted from dry leaves of lemongrass by microwave-assisted steam distillation. The chemical composition of the lemongrass EO was determined using a gas chromatograph coupled to a mass spectrometer. The refractive index and specific gravity of the EO were also determined. Bread was prepared and baked to reach two water activity levels, 0.86 or 0.94, and then 10 μL of P. expansum spore (10 6 spores per mL) suspension was inoculated on the bread surface. Concentrations of lemongrass EO were tested from 125 to 4,000 μL/L air , whereas mold radial growth was measured for 21 days. For sensory evaluation, breads were treated with lemongrass EO vapor at 0, 500, or 1,000 μL/L air for 48 h and tested by 25 untrained panelists. The EO yield was 1.8%, with similar physical properties to those reported previously. Thirteen compounds were the main components in the EO, with citral being the major compound. P. expansum was inhibited for 21 days at 20°C with 750 μL of EO/L air , and its inhibition increased with increasing concentrations of EO. Sensory acceptance of bread exposed to vapor concentrations of 500 or 1,000 μL of EO/L air or without EO was favorable; similar and no significant differences ( P > 0.05) were observed among them.

Vapor phase growth technique of III-V compounds utilizing a preheating step

NASA Technical Reports Server (NTRS)

Olsen, Gregory Hammond (Inventor); Zamerowski, Thomas Joseph (Inventor); Buiocchi, Charles Joseph (Inventor)

1978-01-01

In the vapor phase epitaxy fabrication of semiconductor devices and in particular semiconductor lasers, the deposition body on which a particular layer of the laser is to be grown is preheated to a temperature about 40.degree. to 60.degree. C. lower than the temperature at which deposition occurs. It has been discovered that by preheating at this lower temperature there is reduced thermal decomposition at the deposition surface, especially for semiconductor materials such as indium gallium phosphide and gallium arsenide phosphide. A reduction in thermal decomposition reduces imperfections in the deposition body in the vicinity of the deposition surface, thereby providing a device with higher efficiency and longer lifetime.

Impact of Different e-Cigarette Generation and Models on Cognitive Performances, Craving and Gesture: A Randomized Cross-Over Trial (CogEcig).

PubMed

Caponnetto, Pasquale; Maglia, Marilena; Cannella, Maria Concetta; Inguscio, Lucio; Buonocore, Mariachiara; Scoglio, Claudio; Polosa, Riccardo; Vinci, Valeria

2017-01-01

Introduction: Most electronic-cigarettes (e-cigarette) are designed to look like traditional cigarettes and simulate the visual, sensory, and behavioral aspects of smoking traditional cigarettes. This research aimed to explore whether different e-cigarette models and smokers' usual classic cigarettes can impact on cognitive performances, craving and gesture. Methods: The study is randomized cross-over trial designed to compare cognitive performances, craving, and gesture in subjects who used first generation electronic cigarettes, second generation electronic cigarettes with their usual cigarettes. (Trial registration: ClinicalTrials.gov number NCT01735487). Results: Cognitive performance was not affected by "group condition." Within-group repeated measures analyses showed a significant time effect, indicating an increase of participants' current craving measure in group "usual classic cigarettes (group C)," "disposable cigalike electronic cigarette loaded with cartridges with 24 mg nicotine (group H), second generation electronic cigarette, personal vaporizer model Ego C, loaded with liquid nicotine 24 mg (group E). Measures of gesture not differ over the course of the experiment for all the products under investigation Conclusion: All cognitive measures attention, executive function and working memory are not influenced by the different e-cigarette and gender showing that in general electronics cigarettes could become a strong support also from a cognitive point of view for those who decide to quit smoking. It seems that not only craving and other smoke withdrawal symptoms but also cognitive performance is not only linked to the presence of nicotine; this suggests that the reasons behind the dependence and the related difficulty to quit smoking needs to be looked into also other factors like the gesture. www.ClinicalTrials.gov, identifier NCT01735487.

The effect of e-cigarette warning labels on college students' perception of e-cigarettes and intention to use e-cigarettes.

PubMed

Lee, Hsiao-Yun; Lin, Hsien-Chang; Seo, Dong-Chul; Lohrmann, David K

2018-01-01

This study examined the effect of two e-cigarette warning labels on college students' perceived advantages and risks of e-cigarette use, as well as students' intentions to use e-cigarettes. The company-produced e-cigarette warning label carries abundant information with small font size while the governmental warning label has only two sentences presented in large font size. The effect of both labels have not yet been examined and verified. Data were collected in October 2015 from college students at a Midwestern university. A pretest-posttest design was employed with 338 students exposed to the warning label proposed by the FDA and 328 students exposed to the label created by e-cigarette companies. Structural equation modeling analysis was implemented to examine the effect of warning labels with the analytical model grounded in the Theory of Planned Behavior. Findings showed that college students' perceived advantages of e-cigarette use were positively related to their intentions to use e-cigarettes, while perceived risks were negatively associated with their intentions. When comparing two labels, the governmental label was found to reduce college students' intentions to use e-cigarettes via increasing perceived risks of e-cigarette use (β=0.10, p<0.05), however, not via decreasing perceived advantages of e-cigarette use. The warning label currently used by e-cigarette companies showed no influence on beliefs about or intentions to use e-cigarettes. The warning label proposed by the FDA is more effective than that created by e-cigarette companies, however, has room for improvement to make a greater impact on e-cigarette use intention. Copyright © 2017 Elsevier Ltd. All rights reserved.

E-cigarette advertising exposure in e-cigarette naïve adolescents and subsequent e-cigarette use: A longitudinal cohort study.

PubMed

Camenga, Deepa; Gutierrez, Kevin M; Kong, Grace; Cavallo, Dana; Simon, Patricia; Krishnan-Sarin, Suchitra

2018-06-01

Electronic (E-) cigarettes are one of the most popular tobacco products used by adolescents today. This study examined whether exposure to advertisements in (1) social networking sites (Facebook, Twitter, YouTube, Pinterest/Google Plus), (2) traditional media (television/radio, magazines, billboards), or (3) retail stores (convenience stores, mall kiosks, tobacco shops) was associated with subsequent e-cigarette use in a longitudinal cohort of adolescents. Data were drawn from longitudinal surveys conducted in fall 2013 (wave 1) and spring 2014 (wave 2) of a school-based cohort attending 3 high schools and 2 middle schools in Connecticut. Adolescents were asked about tobacco use behaviors and where they had recently seen e-cigarette advertising at wave 1. We used logistic regression to determine whether advertising exposure at wave 1 increased the odds of e-cigarette use by wave 2, controlling for demographics and cigarette smoking status at wave 1. Among those who have never used e-cigarettes in wave 1 (n = 1742), 9.6% reported e-cigarette use at wave 2. Multivariate logistic regression demonstrated that exposure to e-cigarette advertising on Facebook (OR 2.12 = p < 0.02) at wave 1, but not other venues, significantly increased the odds of subsequent e-cigarette use wave 2. Age, white race, and cigarette smoking at wave 1 also was associated with e-cigarette use at wave 2. This study provides one of the first longitudinal examinations demonstrating that exposure to e-cigarette advertising on social networking sites among youth who had never used e-cigarettes increases the likelihood of subsequent e-cigarette use. Copyright © 2018 Elsevier Ltd. All rights reserved.

Selective detection of vapor phase hydrogen peroxide with phthalocyanine chemiresistors.

PubMed

Bohrer, Forest I; Colesniuc, Corneliu N; Park, Jeongwon; Schuller, Ivan K; Kummel, Andrew C; Trogler, William C

2008-03-26

The use of hydrogen peroxide as a precursor to improvised explosives has made its detection a topic of critical importance. Chemiresistor arrays comprised of 50 nm thick films of metallophthalocyanines (MPcs) are redox selective vapor sensors of hydrogen peroxide. Hydrogen peroxide is shown to decrease currents in cobalt phthalocyanine sensors while it increases currents in nickel, copper, and metal-free phthalocyanine sensors; oxidation and reduction of hydrogen peroxide via catalysis at the phthalocyanine surface are consistent with the pattern of sensor responses. This represents the first example of MPc vapor sensors being oxidized and reduced by the same analyte by varying the metal center. Consequently, differential analysis by redox contrast with catalytic amplification using a small array of sensors may be used to uniquely identify peroxide vapors. Metallophthalocyanine chemiresistors represent an improvement over existing peroxide vapor detection technologies in durability and selectivity in a greatly decreased package size.

E-Cigarette Marketing Exposure Is Associated With E-Cigarette Use Among US Youth.

PubMed

Mantey, Dale S; Cooper, Maria R; Clendennen, Stephanie L; Pasch, Keryn E; Perry, Cheryl L

2016-06-01

E-cigarettes are currently the most commonly used tobacco product among US youth. However, unlike conventional cigarettes, e-cigarettes are not subject to marketing restrictions. This study investigates the association between exposure to e-cigarette marketing and susceptibility and use of e-cigarettes in youth. Data were obtained from the 2014 National Youth Tobacco Survey. Participants were 22,007 US middle and high school students. Multivariate logistic regression models assessed the relationship between e-cigarette marketing (internet, print, retail, and TV/movies) and current and ever use as well as susceptibility to use e-cigarettes among never e-cigarette users. Exposure to each type of e-cigarette marketing was significantly associated with increased likelihood of ever and current use of e-cigarettes among middle and high school students. Exposure was also associated with susceptibility to use of e-cigarettes among current nonusers. In multivariate models, as the number of channels of e-cigarette marketing exposure increased, the likelihood of use and susceptibility also increased. Findings highlight the significant associations between e-cigarette marketing and e-cigarette use among youth and the need for longitudinal research on these relationships. Copyright © 2016 The Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Tobacco and e-cigarette products initiate Kupffer cell inflammatory responses.

PubMed

Rubenstein, David A; Hom, Sarah; Ghebrehiwet, Berhane; Yin, Wei

2015-10-01

Kupffer cells are liver resident macrophages that are responsible for screening and clearing blood of pathogens and foreign particles. It has recently been shown that Kupffer cells interact with platelets, through an adhesion based mechanism, to aid in pathogen clearance and then these platelets re-enter the general systemic circulation. Thus, a mechanism has been identified that relates liver inflammation to possible changes in the systemic circulation. However, the role that Kupffer cells play in cardiovascular disease initiation/progression has not been elucidated. Thus, our objective was to determine whether or not Kupffer cells are responsive to a classical cardiovascular risk factor and if these changes can be transmitted into the general systemic circulation. If Kupffer cells initiate inflammatory responses after exposure to classical cardiovascular risk factors, then this provides a potential alternative/synergistic pathway for cardiovascular disease initiation. We aimed to elucidate the prevalence of this potential pathway. We hypothesized that Kupffer cells would initiate a robust inflammatory response after exposure to tobacco cigarette or e-cigarette products and that the inflammatory response would have the potential to antagonize other salient cells for cardiovascular disease progression. To test this, Kupffer cells were incubated with tobacco smoke extracts, e-cigarette vapor extracts or pure nicotine. Complement deposition onto Kupffer cells, Kupffer cell complement receptor expression, oxidative stress production, cytokine release and viability and density were assessed after the exposure. We observed a robust inflammatory response, oxidative stress production and cytokine release after Kupffer cells were exposed to tobacco or e-cigarette extracts. We also observed a marginal decrease in cell viability coupled with a significant decrease in cell density. In general, this was not a function of the extract formulation (e.g. tobacco vs. e-cigarette

Impact of E-Cigarette Minimum Legal Sale Age Laws on Current Cigarette Smoking.

PubMed

Dutra, Lauren M; Glantz, Stanton A; Arrazola, René A; King, Brian A

2018-05-01

The purpose of this study was to use individual-level data to examine the relationship between e-cigarette minimum legal sale age (MLSA) laws and cigarette smoking among U.S. adolescents, adjusting for e-cigarette use. In 2016 and 2017, we regressed (logistic) current (past 30-day) cigarette smoking (from 2009-2014 National Youth Tobacco Surveys [NYTS]) on lagged (laws enacted each year counted for the following year) and unlagged (laws enacted January-June counted for that year) state e-cigarette MLSA laws prohibiting sales to youth aged <18 or <19 years (depending on the state). Models were adjusted for year and individual- (e-cigarette and other tobacco use, sex, race/ethnicity, and age) and state-level (smoke-free laws, cigarette taxes, medical marijuana legalization, income, and unemployment) covariates. Cigarette smoking was not significantly associated with lagged MLSA laws after adjusting for year (odds ratio [OR] = .87, 95% confidence interval [CI]: .73-1.03; p = .10) and covariates (OR = .85, .69-1.03; p = .10). Unlagged laws were significantly and negatively associated with cigarette smoking (OR = .84, .71-.98, p = .02), but not after adjusting for covariates (OR = .84, .70-1.01, p = .07). E-cigarette and other tobacco use, sex, race/ethnicity, age, and smoke-free laws were associated with cigarette smoking (p <.05). Results unadjusted for e-cigarette use and other tobacco use yielded a significant negative association between e-cigarette MLSA laws and cigarette smoking (lagged: OR = .78, .64-.93, p = .01; unlagged: OR = .80, .68-.95, p = .01). After adjusting for covariates, state e-cigarette MLSA laws did not affect youth cigarette smoking. Unadjusted for e-cigarette and other tobacco use, these laws were associated with lower cigarette smoking. Copyright © 2017 The Society for Adolescent Health and Medicine. All rights reserved.

Acetyl radical generation in cigarette smoke: Quantification and simulations

NASA Astrophysics Data System (ADS)

Hu, Na; Green, Sarah A.

2014-10-01

Free radicals are present in cigarette smoke and can have a negative effect on human health. However, little is known about their formation mechanisms. Acetyl radicals were quantified in tobacco smoke and mechanisms for their generation were investigated by computer simulations. Acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5-tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high-performance liquid chromatography (HPLC), mass spectrometry/tandem mass spectrometry (MS-MS/MS) and liquid chromatography-mass spectrometry (LC-MS). Simulations were performed using the Master Chemical Mechanism (MCM). A range of 10-150 nmol/cigarette of acetyl radical was measured from gas phase tobacco smoke of both commercial and research cigarettes under several different smoking conditions. More radicals were detected from the puff smoking method compared to continuous flow sampling. Approximately twice as many acetyl radicals were trapped when a glass fiber particle filter (GF/F specifications) was placed before the trapping zone. Simulations showed that NO/NO2 reacts with isoprene, initiating chain reactions to produce hydroxyl radical, which abstracts hydrogen from acetaldehyde to generate acetyl radical. These mechanisms can account for the full amount of acetyl radical detected experimentally from cigarette smoke. Similar mechanisms may generate radicals in second hand smoke.

Dual Use of E-Cigarettes and Traditional Cigarettes Among Adolescents in Taiwan, 2014-2016.

PubMed

Chen, Pei-Ching; Chang, Li-Chuan; Hsu, Chieh; Lee, Yue-Chune

2018-02-02

We investigated the use of electronic cigarettes (e-cigarettes) with traditional cigarettes among adolescents during 2014 to 2016 to identify risk factors for using e-cigarettes only, traditional cigarettes only, or both products. We used cross-sectional data from the Taiwan Global Youth Tobacco Survey, (conducted over a 3-year period by the Health Promotion Administration, Ministry of Health and Welfare, Taiwan), which is representative of tobacco use among adolescents aged 12-18 years. The outcome variable was smoking behavior. Dependent variables included gender, grade, monthly income/allowance, parents' educational level, parents' smoking status, close friends' smoking status, use of other tobacco products, contact with cigarette/e-cigarette advertisements, and access to free cigarettes/e-cigarettes. Multinomial regression identify factors influencing the smoking behaviors of adolescents, as manifested in the use of traditional cigarettes only, e-cigarettes only, e-cigarettes with traditional cigarettes, and nonsmoking. When weighted to the population, the sample included 1723150 adolescents in 2014, 1691568 adolescents in 2015, and 1627216 adolescents in 2016. The rates averaged over three years were as follows: nonsmoking (91.6%), traditional cigarettes only (5.4%), e-cigarettes only (1.5%), and dual usage (1.6%). Among adolescents in Taiwan, the following were risk factors for dual use: male, older, high monthly allowance, smoking parents, smoking friends, use of other tobacco products, contact with cigarette advertisements, and access to free cigarettes. Our results revealed an increase in the number of adolescents using e-cigarettes with traditional cigarettes. We recommend that the government continue smoking cessation programs while maintaining control over advertisements and promotions for tobacco products. This is the first study to examine the dual use of e-cigarettes and traditional cigarettes among adolescents in Taiwan. This study identified the

Perceptions of the Harm and Addictiveness of Conventional Cigarette Smoking Among Adolescent E-Cigarette Users.

PubMed

Owotomo, Olusegun; Maslowsky, Julie; Loukas, Alexandra

2018-01-01

Although existing evidence indicates that e-cigarette use is a risk factor for cigarette smoking initiation, mechanisms of this association are not yet known. E-cigarette users perceive e-cigarette use to be less harmful relative to conventional cigarettes, but their absolute perceptions of addictiveness of conventional cigarette smoking are unknown. This study examines how e-cigarette users compare with nonusers (non-e-cigarette users/nonconventional cigarette smokers), conventional cigarette smokers, and dual users on perceptions of harm and the addictiveness of conventional cigarette smoking and on other known predictors of cigarette smoking such as peer smoking, influence of antismoking ads, and risk-taking propensity. National samples of 8th- and 10th-grade students from 2014 and 2015 (N = 14,151) were obtained from the Monitoring the Future Study. Multivariate logistic regression models were used to examine relationships between adolescent smoking status and perceptions of harm and the addictiveness of conventional cigarette smoking while controlling for potential confounders. E-cigarette users had lower perceptions of the addictiveness of conventional cigarette smoking compared with nonusers but higher than cigarette smokers and dual users. E-cigarette users reported lower influence by antismoking ads, more conventional cigarette-smoking peers, and greater risk-taking propensity than nonusers. E-cigarette users and cigarette smokers did not differ in their perceived harm of conventional cigarette smoking or in their risk-taking propensity. E-cigarette users' attitudes and perceptions regarding conventional cigarette smoking may leave them vulnerable to becoming conventional cigarette smokers. Future studies should explore the prospective relationship between smoking-related perceptions of conventional cigarette smoking among e-cigarette users and the onset of cigarette smoking. Copyright © 2017 The Society for Adolescent Health and Medicine. Published

Impact of Exposure to Electronic Cigarette Advertising on Susceptibility and Trial of Electronic Cigarettes and Cigarettes in US Young Adults: A Randomized Controlled Trial.

PubMed

Villanti, Andrea C; Rath, Jessica M; Williams, Valerie F; Pearson, Jennifer L; Richardson, Amanda; Abrams, David B; Niaura, Raymond S; Vallone, Donna M

2016-05-01

This study assessed the impact of brief exposure to four electronic cigarette (e-cigarette) print advertisements (ads) on perceptions, intention, and subsequent use of e-cigarettes and cigarettes in US young adults. A randomized controlled trial was conducted in a national sample of young adults from an online panel survey in 2013. Participants were randomized to ad exposure or control. Curiosity, intentions, and perceptions regarding e-cigarettes were assessed post-exposure and e-cigarette and cigarette use at 6-month follow-up. Analyses were conducted in 2014. Approximately 6% of young adults who had never used an e-cigarette at baseline tried an e-cigarette at 6-month follow-up, half of whom were current cigarette smokers at baseline. Compared to the control group, ad exposure was associated with greater curiosity to try an e-cigarette (18.3% exposed vs. 11.3% unexposed, AOR = 1.63, 95% CI = 1.18, 2.26) among never e-cigarette users and greater likelihood of e-cigarette trial at follow-up (3.6% exposed vs. 1.2% unexposed, AOR = 2.85; 95% CI = 1.07, 7.61) among never users of cigarettes and e-cigarettes. Exploratory analyses did not find an association between ad exposure and cigarette trial or past 30-day use among never users, nor cigarette use among smokers over time. Curiosity mediated the relationship between ad exposure and e-cigarette trial among e-cigarette never users. Exposure to e-cigarette ads may enhance curiosity and limited trial of e-cigarettes in never users. Future studies are needed to examine the net effect of curiosity and trial of e-cigarettes on longer-term patterns of tobacco use. This randomized trial provides the first evidence of the effect of e-cigarette advertising on a behavioral outcome in young adults. Compared to the control group, ad exposure was associated with greater curiosity to try an e-cigarette among never e-cigarette users and greater likelihood of e-cigarette trial at follow-up in a small number of never e-cigarette

How do minimum cigarette price laws affect cigarette prices at the retail level?

PubMed Central

Feighery, E; Ribisl, K; Schleicher, N; Zellers, L; Wellington, N

2005-01-01

Objectives: Half of US states have minimum cigarette price laws that were originally passed to protect small independent retailers from unfair price competition with larger retailers. These laws prohibit cigarettes from being sold below a minimum price that is set by a formula. Many of these laws allow cigarette company promotional incentives offered to retailers, such as buydowns and master-type programmes, to be calculated into the formula. Allowing this provision has the potential to lower the allowable minimum price. This study assesses whether stores in states with minimum price laws have higher cigarette prices and lower rates of retailer participation in cigarette company promotional incentive programmes. Design: Retail cigarette prices and retailer participation in cigarette company incentive programmes in 2001 were compared in eight states with minimum price laws and seven states without them. New York State had the most stringent minimum price law at the time of the study because it excluded promotional incentive programmes in its price setting formula; cigarette prices in New York were compared to all other states included in the study. Results: Cigarette prices were not significantly different in our sample of US states with and without cigarette minimum price laws. Cigarette prices were significantly higher in New York stores than in the 14 other states combined. Conclusions: Most existing minimum cigarette price laws appear to have little impact on the retail price of cigarettes. This may be because they allow the use of promotional programmes, which are used by manufacturers to reduce cigarette prices. New York's strategy to disallow these types of incentive programmes may result in higher minimum cigarette prices, and should also be explored as a potential policy strategy to control cigarette company marketing practices in stores. Strict cigarette minimum price laws may have the potential to reduce cigarette consumption by decreasing demand through

Geographic patterns of cigarette butt waste in the urban environment.

PubMed

Marah, Maacah; Novotny, Thomas E

2011-05-01

This reports the initial phase of a study to quantify the spatial pattern of cigarette butt waste in an urban environment. Geographic Information Systems (GIS) was used to create a weighted overlay analysis model which was then applied to the locations of businesses where cigarettes are sold or are likely to be consumed and venues where higher concentrations of butts may be deposited. The model's utility was tested using a small-scale litter audit in three zip codes of San Diego, California. We found that cigarette butt waste is highly concentrated around businesses where cigarettes are sold or consumed. The mean number of butts for predicted high waste sites was 38.1 (SD 18.87), for predicted low waste sites mean 4.8 (SD 5.9), p<0.001. Cigarette butt waste is not uniformly distributed in the urban environment, its distribution is linked to locations and patterns of sales and consumption. A GIS and weighted overlay model may be a useful tool in predicting urban locations of greater and lesser amounts of cigarette butt waste. These data can in turn be used to develop economic cost studies and plan mitigation strategies in urban communities.

Investigating cigarette affordability in 60 cities using the cigarette price‐daily income ratio

PubMed Central

Kan, Ming‐yue

2007-01-01

Objective To investigate cigarette affordability in 60 cities. Methods Affordability of cigarettes is defined as the ratio of the price of one pack of cigarettes to daily income (cigarette price‐daily income ratio: CPDIR). Daily income data were calculated using the mean of the seven occupations with the lowest daily wage, as listed in the 2006 Union Bank of Switzerland survey; cigarette prices in 2006 were sourced from the Economist Intelligence Unit. Results Cigarette affordability in most of the surveyed cities remains high. There is a tendency for cities with high income economies to have a high level of cigarette affordability. Most of the cities in Western Europe and South and North America have high cigarette affordability, whereas 66.7% of their counterparts in Eastern Europe have medium cigarette affordability. In Asia, all cities with high cigarette affordability belong to the group of upper middle to high income economies, except for the Philippines. In Africa, Johannesburg and Nairobi have high and medium levels of cigarette affordability, respectively. Conclusion Cigarette affordability for most of the sampled cities, especially those in high income economies, is high. There is room for increasing cigarette prices via tax increases. There is a risk that the increase in cigarette prices in newly emerging economies lags behind the high speed of economic growth being experiencing. Tax increases should be given high priority. PMID:18048622

Frequency of E-Cigarette Use and Cigarette Smoking by American Students in 2014.

PubMed

Warner, Kenneth E

2016-08-01

High school students' electronic cigarette (e-cigarette) use rose rapidly in 2014, to levels higher than cigarette smoking, which declined significantly. This study assesses how frequency of e-cigarette use is associated with students' smoking status. Using Monitoring the Future data in 2015, this study evaluated the association between students' smoking and frequency of 30-day e-cigarette use in 2014, focusing on high school seniors. Previous research has considered only whether e-cigarettes were used at all during the past month. Non-smokers were far less likely than smokers to have used an e-cigarette (p<0.001). E-cigarette use frequency rose with the amount of ever smoking (p<0.001). However, among current smokers, there was no difference in e-cigarette use by very light smokers (<1 cigarette/day); light smokers (1-5 cigarettes/day); and heavy smokers (≥1/2 pack/day) (p=0.99). Because most students have never smoked, never smokers constituted 25% of all seniors who used an e-cigarette. Among tenth- and eighth-graders, 43% and 48% of past-month e-cigarette users had never smoked. Non-smoking high school students are highly unlikely to use e-cigarettes; among those who do, most used them only on 1-2 of the past 30 days. By contrast, current smokers are likely to use e-cigarettes and on many more days. It is unclear whether students' e-cigarette use represents short-term experimentation or future sustained use, and whether it will eventually increase or decrease youth smoking and nicotine addiction. More sophisticated research methods, employing better data, will be essential to unravel the mystery that is the e-cigarette phenomenon. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Brand variation in oxidant production in mainstream cigarette smoke: Carbonyls and free radicals.

PubMed

Reilly, Samantha M; Goel, Reema; Trushin, Neil; Elias, Ryan J; Foulds, Jonathan; Muscat, Joshua; Liao, Jason; Richie, John P

2017-08-01

Oxidative stress/damage resulting from exposure to cigarette smoke plays a critical role in the development of tobacco-caused diseases. Carbonyls and free radicals are two major classes of oxidants in tobacco smoke. There is little information on the combined delivery of these oxidants across different cigarette brands; thus, we set out to measure and compare their levels in mainstream smoke from popular US cigarettes. Mainstream smoke from 28 different cigarette brands produced by smoking (FTC protocol) was analyzed for five important, abundant carbonyls, and levels were compared to previously determined free radical for the same brands. Overall, there were large variations (3- to 6-fold) in carbonyl levels across brands with total carbonyl levels ranging from 275 to 804 μg/cigarette, which persisted even after adjusting for ventilation. Individual carbonyl levels were highly correlated with each other (r 2 : 0.40-0.95, P < 0.003) except for formaldehyde. Both gas-phase (r 2 : 0.37, P = 0.006) and particulate-phase (r 2 : 0.27, P = 0.005) free radicals were correlated to total carbonyl content; however, this correlation disappeared after adjusting for ventilation. These data show that overall oxidant production varies widely by cigarette brand and the resulting difference in oxidant burden could potentially lead to differences in disease risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

E-Cigarette Toxicity?

PubMed

Tegin, Gulay; Mekala, Hema Madhuri; Sarai, Simrat Kaur; Lippmann, Steven

2018-01-01

Tobacco smoking is the most preventable cause of morbidity and mortality. In just a few short years, electronic cigarettes (e-cigarettes) have become increasingly popular, especially for younger individuals. Many people believe that e-cigarettes are safe. The inhaled aerosols of e-cigarettes contain numerous potential toxicities, some of which could be dangerous for health with long-term use. The safety of prolonged aerosol exposure is not known. The use of e-cigarettes as a harm-reduction tool at stopping tobacco smoking is not uniformly successful. E-cigarettes may be safer than tobacco products, but repeated prolonged exposure to their aerosols has its own considerable potential risk. The long-term health consequences of their use remain to be established. Physicians should vigorously discourage the use of e-cigarettes and tobacco products, with special emphasis on abstinence for younger people and during pregnancy or lactation.

Other tobacco product and electronic cigarette use among homeless cigarette smokers

PubMed Central

Baggett, Travis P.; Campbell, Eric G.; Chang, Yuchiao; Rigotti, Nancy A.

2016-01-01

Objective We determined the prevalence and correlates of other tobacco product and electronic cigarette (e-cigarette) use in a clinic-based sample of homeless cigarette smokers. Methods In April-July 2014, we used time-location sampling to conduct a cross-sectional, in-person survey of 306 currently homeless adult cigarette smokers recruited from 5 clinical sites at Boston Health Care for the Homeless Program. We assessed past-month use of large cigars, little cigars, smokeless tobacco, and e-cigarettes. Among those who had used e-cigarettes, we assessed the reasons for doing so. We used logistic regression analysis to identify the participant characteristics associated with the use of each product. Results Eighty-six percent of eligible individuals participated in the survey. In the past month, 37% of respondents used large cigars, 44% used little cigars, 8% used smokeless tobacco, 24% used an e-cigarette, and 68% used any of these products. Reasons for e-cigarette use included curiosity (85%) and to help quit conventional cigarettes (69%). In multivariable regression analyses, homeless smokers with greater subsistence difficulties were more likely to use little cigars (p=0.01) and less likely to use e-cigarettes (p=0.001). Non-Hispanic black (p=0.01), Hispanic (p<0.001), and rough-sleeping (p=0.04) participants were more likely to use large cigars. Readiness to quit was not associated with other tobacco product use but was significantly associated with e-cigarette use to help quit smoking (p=0.02). Conclusions Health care providers who serve homeless people should consider routine screening for the use of other tobacco products and e-cigarettes to help guide smoking cessation discussions and tobacco treatment planning. PMID:27128808

Other tobacco product and electronic cigarette use among homeless cigarette smokers.

PubMed

Baggett, Travis P; Campbell, Eric G; Chang, Yuchiao; Rigotti, Nancy A

2016-09-01

We determined the prevalence and correlates of other tobacco product and electronic cigarette (e-cigarette) use in a clinic-based sample of homeless cigarette smokers. In April-July 2014, we used time-location sampling to conduct a cross-sectional, in-person survey of 306 currently homeless adult cigarette smokers recruited from 5 clinical sites at Boston Health Care for the Homeless Program. We assessed past-month use of large cigars, little cigars, smokeless tobacco, and e-cigarettes. Among those who had used e-cigarettes, we assessed the reasons for doing so. We used logistic regression analysis to identify the participant characteristics associated with the use of each product. Eighty-six percent of eligible individuals participated in the survey. In the past month, 37% of respondents used large cigars, 44% used little cigars, 8% used smokeless tobacco, 24% used an e-cigarette, and 68% used any of these products. Reasons for e-cigarette use included curiosity (85%) and to help quit conventional cigarettes (69%). In multivariable regression analyses, homeless smokers with greater subsistence difficulties were more likely to use little cigars (p=0.01) and less likely to use e-cigarettes (p=0.001). Non-Hispanic black (p=0.01), Hispanic (p<0.001), and rough-sleeping (p=0.04) participants were more likely to use large cigars. Readiness to quit was not associated with other tobacco product use but was significantly associated with e-cigarette use to help quit smoking (p=0.02). Health care providers who serve homeless people should consider routine screening for the use of other tobacco products and e-cigarettes to help guide smoking cessation discussions and tobacco treatment planning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combustible cigarettes cost less to use than e-cigarettes: global evidence and tax policy implications.

PubMed

Liber, Alex C; Drope, Jeffrey M; Stoklosa, Michal

2017-03-01

Some scholars suggest that price differences between combustible cigarettes and e-cigarettes could be effective in moving current combustible smokers to e-cigarettes, which could reduce tobacco-related death and disease. Currently, in most jurisdictions, e-cigarettes are not subject to the same excise taxes as combustible cigarettes, potentially providing the category with a price advantage over combustible cigarettes. This paper tests whether e-cigarettes tax advantage has translated into a price advantage. In a sample of 45 countries, the price of combustible cigarettes, disposable e-cigarettes and rechargeable cigarettes were compared. Comparable units of combustible cigarettes cost less than disposable e-cigarettes in almost every country in the sample. While the e-liquids consumed in rechargeable e-cigarettes might cost less per comparable unit than combustible cigarettes, the initial cost to purchase a rechargeable e-cigarette presents a significant cost barrier to switching from smoking to vaping. Existing prices of e-cigarettes are generally much higher than of combustible cigarettes. If policymakers wish to tax e-cigarettes less than combustibles, forceful policy action-almost certainly through excise taxation-must raise the price of combustible cigarettes beyond the price of using e-cigarettes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

E-Cigarette Marketing Exposure is Associated with E-cigarette Use among U.S. Youth