Vapor Products Research Articles

Adolescent Risk Behaviors and Use of Electronic Vapor Products and Cigarettes.

Adolescent use of tobacco in any form is unsafe; yet the use of electronic cigarettes and other electronic vapor products (EVPs) has increased in recent years among this age group. We assessed the prevalence and frequency of cigarette smoking and EVP use among high school students, and associations between health-risk behaviors and both cigarette smoking and EVP use. We used 2015 national Youth Risk Behavior Survey data (N = 15 624) to classify students into 4 mutually exclusive categories of smoking and EVP use based on 30-day use: nonuse, cigarette smoking only, EVP use only, and dual use. Prevalence of cigarette smoking and EVP use were assessed overall and by student demographics and frequency of use. Prevalence ratios were calculated to identify associations with health risk-behaviors. In 2015, 73.5% of high school students did not smoke cigarettes or use EVPs, 3.2% smoked cigarettes only, 15.8% used EVPs only, and 7.5% were dual users. Frequency of cigarette smoking and EVP use was greater among dual users than cigarette-only smokers and EVP-only users. Cigarette-only smokers, EVP-only users, and dual users were more likely than nonusers to engage in several injury, violence, and substance use behaviors; have ≥4 lifetime sexual partners; be currently sexually active; and drink soda ≥3 times/day. Only dual users were more likely than nonusers not to use a condom at last sexual intercourse. EVP use, alone and concurrent with cigarette smoking, is associated with health-risk behaviors among high school students.

E-Cigarettes and Adolescents' Risk Status.

The prevalence of e-cigarette use was only in the low single digits a few years ago but currently reaches ≥30% among high school students, and at least half are regular users.1,2 This rapid explosion of e-cigarette use has caught the field by surprise, and researchers are scrambling to understand the implications for public health. In their paper “Adolescent Risk Behaviors and Use of Electronic Vapor Products and Cigarettes,” Demissie et al3 provide a useful new perspective on this phenomenon. The researchers showed that 16% of the adolescent population used e-cigarettes only, 3% only smoked cigarettes, and 8% were dual users (cigarettes and e-cigarettes). The good news is that 73% of the adolescent population did not use any tobacco-related product (nonusers). However, that 27% of adolescents still do is not comforting to public health researchers and advocates. Here I bring out 3 points about how this paper helps us understand how e-cigarette use is related to adolescents’ risk status overall. The pattern of results in Demissie et al3 shows that youth … Address correspondence to Thomas A. Wills, PhD, Cancer Prevention and Control Program, University of Hawaii Cancer Center, 701 Ilalo St, Room 528, Honolulu, HI 96813. E-mail: twills{at}cc.hawaii.edu

Identifying Topics for E-Cigarette User-Generated Contents: A Case Study From Multiple Social Media Platforms

BackgroundElectronic cigarette (e-cigarette) is an emerging product with a rapid-growth market in recent years. Social media has become an important platform for information seeking and sharing. We aim to mine hidden topics from e-cigarette datasets collected from different social media platforms.ObjectiveThis paper aims to gain a systematic understanding of the characteristics of various types of social media, which will provide deep insights into how consumers and policy makers effectively use social media to track e-cigarette-related content and adjust their decisions and policies.MethodsWe collected data from Reddit (27,638 e-cigarette flavor-related posts from January 1, 2011, to June 30, 2015), JuiceDB (14,433 e-juice reviews from June 26, 2013 to November 12, 2015), and Twitter (13,356 “e-cig ban”-related tweets from January, 1, 2010 to June 30, 2015). Latent Dirichlet Allocation, a generative model for topic modeling, was used to analyze the topics from these data.ResultsWe found four types of topics across the platforms: (1) promotions, (2) flavor discussions, (3) experience sharing, and (4) regulation debates. Promotions included sales from vendors to users, as well as trades among users. A total of 10.72% (2,962/27,638) of the posts from Reddit were related to trading. Promotion links were found between social media platforms. Most of the links (87.30%) in JuiceDB were related to Reddit posts. JuiceDB and Reddit identified consistent flavor categories. E-cigarette vaping methods and features such as steeping, throat hit, and vapor production were broadly discussed both on Reddit and on JuiceDB. Reddit provided space for policy discussions and majority of the posts (60.7%) holding a negative attitude toward regulations, whereas Twitter was used to launch campaigns using certain hashtags. Our findings are based on data across different platforms. The topic distribution between Reddit and JuiceDB was significantly different (P<.001), which indicated that the user discussions focused on different perspectives across the platforms.ConclusionsThis study examined Reddit, JuiceDB, and Twitter as social media data sources for e-cigarette research. These mined findings could be further used by other researchers and policy makers. By utilizing the automatic topic-modeling method, the proposed unified feedback model could be a useful tool for policy makers to comprehensively consider how to collect valuable feedback from social media.

Visualization and research of gas-liquid two phase flow structures in cylindrical channel

Two-phase flows are commonly found in many industries, especially in systems, where efficient and correct functioning depend on specific values of flow parameters. In thermal engineering and chemical technology the most popular types of two-phase mixture are gas-liquid or liquid-vapour mixtures. Bubbles can create in flow different structures and determine diverse properties of flow (velocity of phase, void fraction, fluctuations of pressure, pipe vibrations, etc.). That type of flow is difficult to observe, especially in liquid-vapour mixture, where vapour is being made by heating the medium. Production of vapour and nucleation process are very complicated issues, which are important part of two-phase flow phenomenon. Gas-liquid flow structures were observed and described with figures, but type of structure depends on many parameters. Authors of this paper made an attempt to simulate gas-liquid flow with air and water. In the paper there was presented specific test stand built to observe two-phase flow structures, methodology of experiment and conditions which were maintained during observation. The paper presents also the structures which were observed and the analysis of results with reference to theoretical models and diagrams available in literature.

A new method for production of titanium vapor and synthesis of titanium nitride coatings

It is proposed to synthesize on machine parts and cutting tools wear-resistant titanium nitride coatings with the help of the hollow-cathode glow discharge, a molybdenum crucible for titanium evaporation being used as the anode of the discharge and a process vacuum chamber being used as the hollow cathode. The research revealed that at the anode surface area less than a critical value S* = (2 m / M ) 1/2 S , where S is the area of the chamber walls, m is the mass of electrons and M is the mass of ions, the anode fall of potential is positive and grows from ∼50 V at argon pressure p = 0.2 Pa to ∼2 kV at p = 0.02 Pa. At the discharge current I = 0.6 A electrons accelerated by the anode fall of 0.9 kV transport into the crucible with the inner diameter of 12 mm the power of ∼0.54 kW, which allows the titanium evaporation and the coating deposition rate of 5 µm·h −1 on a substrate distanced from the crucible at 100 mm. After the argon is replaced with the nitrogen, titanium nitride coating without titanium droplets is synthesized the deposition rate amounting to about the same value.

COAL MINI CHP PLANTS ON THE BASIS OF A GAS GENERATOR AND ELECTROCHEMICAL GENERATOR

Synthesis gas for electrochemical generator was produced in gas generator with automatic steam gasification of coal Borodino deposits. The paper compiles the thermal balances battery of solid oxide fuel cells (SOFC) and boiler, intended for production of superheated water vapor for a gas generator and heating the cathode air. On the base of these balances, the proportion of hydrogen, oxidized anode SOFC; electrical efficiency; the temperature in the anode; losses with flue gases and to the surroundings through the thermal insulation; fuel cell EMF were calculated. Moreover, it was determined unit cost of coal for the production of electrical and heat energy.

E-Cig Tipping Points vs. FDA Deeming Regulations

E-cigarettes and related vapor products (e-cigs) are here to stay. They have tipped from a fad to a permanent part of the tobacco product scene. They now constitute a ten year old multibillion dollar industry in the United States. More likely than not, they offer personal and public health benefits far exceeding theoretically plausible harms. The current FDA “deeming” regulations threaten to eliminate more than 99% of e-cig products by imposing requirements so costly that few can afford to apply. Federal regulation of all tobacco-related products is needed to best protect the health of the public. Instead, the current regulations protect cigarettes from competition from e-cigs and other lowrisk alternatives and threaten to drive dedicated e-cig users back to cigarettes or to hazardous contraband and home-made products. Alternatives to the current regulations are proposed.

Development of the disruptive technique of pulsed metal vapor production

Development of the disruptive technique of pulsed metal vapor production

Large-Eddy Simulation of convective wall-boiling flow along an idealized PWR rod bundle

A LES analysis of turbulent convective boiling flow along the rods of a PWR sub-channel was performed using the code TransAT. The campaign is an extension of a former attempt in which the flow was predicted by means of DNS (or super resolved LES). The extension refers to accounting for wall-boiling heat transfer using the triple flux decomposition model, employed within the LES approach constructed on the basis of the filtered mixture equations. The results in the wall boiling configuration differ from the single-flow case in many ways, but more particularly: the flow seems to be portioned in three zones, (i) pre-boiling, (ii) transitional boiling, and (iii) post-boiling, where turbulence activity increases with distance from the onset of nucleate boiling location, affecting heavily the dynamic and thermal boundary layers. The boundary layers thin quite substantially in the post-boiling section, and the flow accelerates due to higher volumetric flow rate induced by phase change, notably in the gap region. The vorticity distribution between the single flow and boiling flow cases suggests that boiling causes a higher rate of vorticity generation. These results corroborate with the other finding, that is: the average frictional velocity in the boiling case increases by a factor of 1.5. Scrutinizing the power density spectra reveals that the boiling flow embodies about twice more energy than the single phase flow, with marked large-scale energetic eddies at the upper end of the rods, i.e. z/L>0.8. A clear transitional behavior is observed in the boiling flow PSD, in that the amount of energy embodied in the flow increases with vapor production.

Hydrothermal carbonization (HTC) of loblolly pine using a continuous, reactive twin-screw extruder

Hydrothermal carbonization (HTC) has become an accepted means of converting a wide variety of lignocellulosic feedstocks into solid hydrochars, which have improved physical and chemical properties compared to raw biomass. To date, HTC applications have involved batch or semi-continuous process systems, which has limited their economic viability. The work presented here describes a fully-continuous HTC process, made possible by use of a specially modified twin-screw extruder (TSE). The reaction time within this fast HTC (FHTC) reactor system is very short (20–30sec) as compared to a typical batch reactor. Therefore, the concept of reaction ‘severity factor’ is used when comparing the FHTC products with those produced in other reactor systems. While solid hydrochar produced in the FHTC system has different physical properties than hydrochar from batch reactor systems, these materials exhibit similar energy densification and pelletization behavior, when produced under comparable severity conditions. However, total hydrochar yields are considerably higher from the FHTC reactor compared to batch reactor systems. This is a consequence of the de-pressurization process in the FHTC system, whereby most water-soluble organic products are retained in the hydrochar, rather than exiting the process in a separate aqueous product stream. FHTC treatment of loblolly pine at a severity factor of 5.3 (290°C) produced a hydrochar yield of nearly 85% (based on dry feedstock mass). Condensation of the flashed vapor products provided a relatively clean water stream, containing only 1.2% organics – primarily furfural and acetic acid. Recovery of these organics and recycling of the condensed water would further improve the cost-effectiveness of FHTC operations.

US Adults' Perceptions of the Harmful Effects During Pregnancy of Using Electronic Vapor Products Versus Smoking Cigarettes, Styles Survey, 2015.

IntroductionResearch suggests aerosol from electronic vapor products (EVPs) has fewer harmful constituents than conventional cigarette smoke. Even so, EVPs and other nicotine-containing products are not safe to use during pregnancy. We examined perceptions among US adults regarding harm in using EVPs rather than smoking cigarettes during pregnancy.MethodsData came from the 2015 Styles Survey, an Internet panel survey of a sample of US adults aged 18 years or older (N = 4,127). Perceived harm was assessed by asking respondents whether using EVPs was less, equally, or more harmful for pregnant women than smoking cigarettes. Descriptive statistics were used to estimate perceived harm overall and by sociodemographic characteristics and tobacco-use status. Perceived harm was assessed among all adults, women of reproductive age (18–44 years, n = 820), and women of nonreproductive age (≥45 years, n = 1,398).ResultsAmong all adults, 11.1% believed using EVPs during pregnancy was less harmful than smoking conventional cigarettes, 51.0% believed it was equally harmful, 11.6% believed it was more harmful, and 26.2% did not know. Prevalence of perception of less harm, by demographic category, was greatest among adults aged 18 to 24 years, men, non-Hispanic whites, adults with less than a high school diploma, current EVP users, and current cigarette smokers (P < .05). Prevalence of perception of less harm was greater among women of reproductive age (9.6%) than among those of nonreproductive age (7.9%) (P < .05).ConclusionUS adults have varying levels of perceptions about the harms of EVP use versus cigarette smoking during pregnancy. Efforts are warranted to prevent nicotine exposure during pregnancy and to educate adults on the dangers of using any form of tobacco during pregnancy, including EVPs.

Comparative Study of H-ZSM 5 Zeolite and Graphite Nanofiber (GNF) in Catalytic Pyrolysis of Oil Palm Fronds (OPF)

In keeping an eye on the goal of a sustainable chemical and energy industry, bio-oil produced from biomass fast pyrolysis liquefaction has aroused great interests and attentions among various stakeholders. In present paper, carbon based catalyst, Graphite Nanofiber (GNF) was employed to investigate and evaluate its potential in thermal pyrolysis of Oil Palm Frond (OPF). The pyrolysis was carried out in a semi batch reactor which was externally heated by an electrical vertical split tube furnace. 15g of OFP biomass with 1.5g of catalysts is thermally decomposed at two distinct temperatures of 573K and 773K, producing a solid char residue and a liquefied vapour product after passing through a condenser. Comparative study of both catalyst performances in thermal pyrolysis of OPF was conducted in term of selectivity and conversion. Between Zeolite ZSM-5 and GNF, GNF catalysts achieved a better conversion performance in transforming a total of 66.57 wt% and 72.40 wt% of biomass into vapour and liquid products at 573K and 773K respectively. On the other hand, H-ZSM 5 Zeolite catalyst yields the highest selectivity of 64.33 wt% toward condensable vapour components at 773K with a remarkably high bio-oil yield of 45.71 wt%. Such superior results strengthened the fact of H-ZSM 5 Zeolite catalysts being the more effective catalyst than GNF in catalytic pyrolysis of OPF.&#x0D; Keywords: Catalytic Pyrolysis, Oil Palm Fronds, Bio-Oil, Graphite Nanofiber, H-ZSM 5 Zeolite

Fire behaviour of gypsum plasterboard wall assemblies: CFD simulation of a full-scale residential building

Gypsum “dehydration” phenomena, occurring when gypsum plasterboard wall assemblies are exposed to a high temperature environment, result in water vapour production and subsequent dispersion in the fire compartment; these phenomena are often neglected in relevant Computational Fluid Dynamics (CFD) simulations. Aiming to investigate the impact of gypsum dehydration in full-scale CFD simulations of lightweight drywall buildings, the FDS code is used to simulate a two-storey residential building, exposed to a typical domestic fire scenario. The building employs a structural steel frame combined with gypsum plasterboard wall assemblies. Temperature-dependent thermo-physical properties are used for all construction materials. The effects of gypsum dehydration are assessed by using two alternative modelling approaches, an effective specific heat model and a solid reaction kinetics model; the obtained predictions are compared to a benchmark test case, where no such phenomena are modelled. The obtained results demonstrate that when the highly endothermic gypsum dehydration phenomena are simulated, lower overall heat release rates, gas and wall surface temperatures are predicted. In addition, the developed solid reaction kinetics model allows, for the first time, quantitative predictions of gypsum dehydration induced water vapour production and dispersion phenomena.

A randomised, parallel group study to evaluate the safety profile of an electronic vapour product over 12 weeks

A randomised, parallel group clinical study was performed to evaluate the safety profile of an e-vapour product (EVP; 2.0% nicotine) in smokers of conventional cigarettes (CCs) switching to use the EVP for 12 weeks. During the study, no clinically significant product-related findings were observed in terms of vital signs, electrocardiogram, lung function tests and standard clinical laboratory parameters. Adverse events (AEs) reported by EVP subjects were more frequent during the first week after switching to the EVP. The frequency of AEs reduced thereafter and out of a total of 1515 reported AEs, 495 were judged as being related to nicotine withdrawal symptoms. The most frequently stated AEs were headache, sore throat, desire to smoke and cough reported by 47.4, 27.8, 27.5 and 17.0% of subjects, respectively. Only 6% of AEs were judged as probably or definitely related to the EVP. Additional observations in EVP subjects included a decrease in the level of urine nicotine equivalents by up to 33.8%, and decreases in the level of three biomarkers of exposure to toxicants known to be present in CC smoke (benzene, acrolein and 4-[methylnitrosamino]-1-[3-pyridyl]-1-butanone). The decrease in nicotine equivalents coincided with an increase in nicotine withdrawal symptoms, measured by a questionnaire, which subsided after two weeks. The data presented here shows the potential EVPs may offer smokers looking for an alternative to CCs.

On numerical simulation of cavitating flows under thermal regime

In this work, we investigate closure laws for the description of interfacial mass transfer in cavitating flows under thermal regime. In a first part, we show that, if bubble resident time in the low pressure area of the flow is larger than the inertial/thermal regime transition time, bubble expansion are no longer monitored by Rayleigh equation, but by heat transfer in the liquid phase at bubbles surfaces. The modelling of interfacial heat transfer depends thus on a Nusselt number that is a function of the Jakob number and of the bubble thermal Péclet number. This original approach has the advantage to include the kinetic of phase change in the description of cavitating flow and thus to link interfacial heat flux to interfacial mass flux during vapour production. The behaviour of such a model is evaluated for the case of inviscid cavitating flow in expansion tubes for water and refrigerant R114 using a four equations mixture model. Compared with inertial regime (Rayleigh equation), results obtained considering thermal regime seem to predict lower local gas volume fraction maxima as well as lower gradients of velocity and gas volume fraction. It is observed that global vapour production is closely monitored by volumetric interfacial area (bubble size and gas volume fraction) and mainly by the Jakob number variations. It is found that, in contrast with phase change occurring in common boiling flow, Jakob number variation is influenced by phasic temperature difference but also by density ratio variation with pressure and temperature (Ja∝(ρL/ρG)ΔT).

Surface-Enhanced Separation of Water from Hydrocarbons: Potential Dewatering Membranes for the Catalytic Fast Pyrolysis of Pine Biomass

The impact of surface-selective coatings on water permeation through a membrane when exposed to catalytic fast pyrolysis (CFP) vapor products was studied by tailoring the surface properties of the membrane coating from superhydrophilic to superhydrophobic. Our approach used high-performance architectured surface-selective (HiPAS) membranes that were inserted after a CFP reactor. At this insertion point, the inner wall surface of a tubular membrane was exposed to a mixture of water and upgraded product vapors, including light gases and deoxygenated hydrocarbons. Under proper membrane operating conditions, a high selectivity for water over one-ring upgraded biomass pyrolysis hydrocarbons was observed as a result of a surface-enhanced capillary condensation process. Owing to this surface-enhanced effect, HiPAS membranes have the potential to enable high flux separations, suggesting that water can be selectively removed from the CFP product vapors.

Prevention of Complications of Endovenous Laser Treatment

Treatment of varicose vein disease should provide reliable exclusion of varicose veins from blood circulation, be minimally traumatic, ensure a satisfactory aesthetic effect as well as minimize side effects. The use of endovenous laser treatment allows achieving optimal results. Laser technology, however, may cause a number of complications, in particular segmental thrombophlebitis, ecchymosis, skin hyperpigmentation, neurological disorders, and paravasal burns. There are complications specific to laser treatment as well: during coagulation, multiple gas bubbles can be observed on the screen of the ultrasound machine, which are formed on the light guide face-end and enter the central venous system, pulmonary circulation and blood vessels of the brain through sapheno-femorale fistula. In the early postoperative period, most of the operated patients suffer from headache, dizziness, nausea, feeling of “heaviness” when breathing, and general weakness lasting for 6-7 days and affecting the normal course of the postoperative period. Thus, there has been suggested the method for preventing specific complications of endovenous laser treatment by active removal of laser coagulation products, which are formed at the working end of the light guide, in order to minimize the number of these products entering the central venous system through sapheno-femorale fistula and perforating veins (Application for an invention u201605586). The task can be achieved by draining the coagulation zone and removing the products of vaporization and carbonization from the lumen of the vein through a drainage catheter, connected to the vacuum source. The implementation of the method allows preventing complications caused by the products of vaporization and photocoagulation, which can enter the pulmonary circulation and blood vessels of the brain through the venous system.

Validation and update of OMI Total Column Water Vapor product

Abstract. The collection 3 Ozone Monitoring Instrument (OMI) Total Column Water Vapor (TCWV) data generated by the Smithsonian Astrophysical Observatory's (SAO) algorithm version 1.0 and archived at the Aura Validation Data Center (AVDC) are compared with NCAR's ground-based GPS data, AERONET's sun-photometer data, and Remote Sensing System's (RSS) SSMIS data. Results show that the OMI data track the seasonal and interannual variability of TCWV for a wide range of climate regimes. During the period from 2005 to 2009, the mean OMI−GPS over land is −0.3 mm and the mean OMI−AERONET over land is 0 mm. For July 2005, the mean OMI−SSMIS over the ocean is −4.3 mm. The better agreement over land than over the ocean is corroborated by the smaller fitting residuals over land and suggests that liquid water is a key factor for the fitting quality over the ocean in the version 1.0 retrieval algorithm. We find that the influence of liquid water is reduced using a shorter optimized retrieval window of 427.7–465 nm. As a result, the TCWV retrieved with the new algorithm increases significantly over the ocean and only slightly over land. We have also made several updates to the air mass factor (AMF) calculation. The updated version 2.1 retrieval algorithm improves the land/ocean consistency and the overall quality of the OMI TCWV data set. The version 2.1 OMI data largely eliminate the low bias of the version 1.0 OMI data over the ocean and are 1.5 mm higher than RSS's “clear” sky SSMIS data in July 2005. Over the ocean, the mean of version 2.1 OMI−GlobVapour is 1 mm for July 2005 and 0 mm for January 2005. Over land, the version 2.1 OMI data are about 1 mm higher than GlobVapour when TCWV &lt; 15 mm and about 1 mm lower when TCWV &gt; 15 mm.

WITHDRAWN: Droplet-laden flows and vapour production in large-scale evaporating liquid fuel cascades

WITHDRAWN: Droplet-laden flows and vapour production in large-scale evaporating liquid fuel cascades

Vapor products exposure and risk assessment assumption refinement: Ingredient transfer

Vapor products exposure and risk assessment assumption refinement: Ingredient transfer