Systematic study of the impact of chemistry and radiation on extinction and carbon monoxide formation at low scalar dissipation rates

2020 ◽  
Vol 117 ◽  
pp. 103212 ◽  
Author(s):  
B. Kruljevic ◽  
I. Stankovic ◽  
B. Merci
2013 ◽  
Vol 64 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Nermina Djulančić ◽  
Vesna Radojičić ◽  
Marija Srbinovska

The aim of this study was to examine the impact of three main tobacco types (flue-cured FC, air-cured AC and sun-cured SC) and two tobacco-based materials (reconstituted tobacco - recon RT and expanded stem) on the formation of carbon monoxide (CO) in the gas phase of mainstream cigarette smoke. The results showed that the type of tobacco examined had a significant impact on the amount of carbon monoxide production in the gas phase of cigarette smoke. AC and SC tobaccos had the most evident impact. The amount of tobacco in mixtures M1, M2 and M3 as well as the addition of expanded stems had an impact on the amount of CO formed in the cigarette smoke. There is weak correlation between CO content in the smoke and the chemical composition of the tobacco. Draw resistance had an impact on CO production. The research results are of great importance, since tobacco selection is the first step in the production of cigarettes with reduced emission of harmful elements contained in the smoke.


2017 ◽  
Vol 27 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Eleanor L Leavens ◽  
Leslie M Driskill ◽  
Neil Molina ◽  
Thomas Eissenberg ◽  
Alan Shihadeh ◽  
...  

IntroductionOne possible reason for the rapid proliferation of waterpipe (WP) smoking is the pervasive use of flavoured WP tobacco. To begin to understand the impact of WP tobacco flavours, the current study examined the impact of a preferred WP tobacco flavour compared with a non-preferred tobacco flavoured control on user’s smoking behaviour, toxicant exposure and subjective smoking experience.MethodThirty-six current WP smokers completed two, 45-minute ad libitum smoking sessions (preferred flavour vs non-preferred tobacco flavour control) in a randomised cross-over design. Participants completed survey questionnaires assessing subjective smoking experience, exhaled carbon monoxide (eCO) testing, and provided blood samples for monitoring plasma nicotine. WP smoking topography was measured continuously throughout the smoking session.ResultsWhile participants reported an enhanced subjective smoking experience including greater interest in continued use, greater pleasure derived from smoking, increased liking and enjoyment, and willingness to continue use after smoking their preferred WP tobacco flavour (p values <0.05), no significant differences were observed in nicotine and carbon monoxide boost between flavour preparations. Greater average puff volume (p=0.018) was observed during the non-preferred flavour session. While not significant, measures of flow rate, interpuff interval (IPI), and total number of puffs were trending towards significance (p values <0.10), with decreased IPI and greater total number of puffs during the preferred flavour session.DiscussionThe current study is the first to examine flavours in WP smoking by measuring preferred versus control preparations to understand the impact on subjective experience, smoking behaviour and toxicant exposure. The pattern of results suggests that even this relatively minor manipulation resulted in significant changes in subjective experience. These results indicate a possible need for regulations restricting flavours in WP tobacco as with combustible cigarettes.


Author(s):  
Wirya Sarwana ◽  
Akihiko Anzai ◽  
Daichi Takami ◽  
Akira Yamamoto ◽  
Hisao Yoshida

Photocatalytic steam reforming of methane (PSRM) has been studied as an attractive method to produce hydrogen by utilizing photoenergy like solar energy around room temperature with metal-loaded photocatalysts, where methane...


Author(s):  
Beschasnyi S.P. ◽  
Lysenko E.M. ◽  
Hasiuk O.M. ◽  
Erlish О.О.

Carbon monoxide is a toxic gas that is colourless, odourless, and has the potential to cause momentaryhypoxia by bonding with heme-inspired proteins. Because of these properties, it causes the highest number of toxications. Due to its properties, this gas causes damage to the nervous and cardiovascular system. The development of anoxia is associated with the impact on the system of oxidative phosphorylation in mitochondria and the development of oxidative stress in the body. The body produces a small amount of carbon monoxide as a result of erythrocyte breakdown. Picomolar concentrations of carbon monoxide even have anti-inflammatory, antiapoptotic,cytoprotective and antiproliferative properties. Kidney is one of the first organs,that responds to the occurrence of hypoxia, are responsible for the removal of products of metabolism and toxicants, including ethanol. For the study, the blood and urine samples were taken from patients with acute intoxication. The amount of methemoglobin in the blood was determined by spectrophotometric method. The concentration of ethanol in blood and urine was measured by gas-liquid chromatography method. The correlation analysis showed that carbon monoxide affects the rate of excretion of ethanol from the body. Among individuals under 40 years of age, there was a correlation between the level of carbon monoxide and the amount of ethanol in the blood. Among older adults this correlation was not established. A direct correlation with the level of this gas in the blood and the level of ethanol in the urine among people under 40 years of age was found. Among older individuals, the opposite was observed –a high level of methemoglobin was responsible for the decreased level of ethanol. There were no correlations between methemoglobin level and age. Comparison of the studied indices did not show any sexual differences in ethanol excretion, but there were age specific features: ethanol excretion under the influence of carbon monoxide among people under 40 years old was more accelerated.Key words:hypoxia, CO intoxication, blood, methemoglobin, kidneys. Монооксид карбону являє собою токсичний газ, який не має кольору,без запаху та здатен спричиняти миттєву гіпоксію шляхом зв’язування з гем-вмісними білками. Через такі властивості він спричиняє найбільшу кількість отруєнь. Цей газ,завдяки своїм властивостям,спричиняє ураження нервової та серцево-судинної системи. Розвиток аноксії пов’язаний із впливом на систему окисного фосфорилювання у мітохондріях та розвиткомоксидативного стресу. В організмі продукується невелика кількість ендогенного монооксиду карбону внаслідок розпаду еритроцитів. Пікомолярні концентрації монооксиду карбону навіть володіють протизапальними, антиапоптичними, цитопротекторними та антипроліферативними властивостями. Нирки є одним із перших органів, який реагує на розвитокгіпоксії, вони відповідають за видалення продуктів метаболізму й токсикантів, зокрема етанолу.Зміни у функціонуванні нирок відображаються на загальному стані організму.Для дослідження отримували зразки крові та сечі від осіб із гострою інтоксикацією. У крові спектрофотометричним методом визначали вміст метгемоглобіну, який утворювався внаслідок вдихання монооксиду карбону та відповідного потрапляння до кровоносної системи. Методом газово-рідинної хроматографії вимірювали концентрацію етанолу у крові та сечі. Розрахунок кореляційних зв’язків показав, що монооксид карбону впливає на швидкість екскреції етанолу. У осіб до 40 років спостерігалася кореляція між показником рівня метгемоглобінута вмістом етанолу у крові. У осіб старшого віку цього зв’язку не встановлено. Виявлено прямий зв’язок із рівнем цього газу у крові та рівнем етанолу в сечі у осіб до 40 років. У осіб старшого віку спостерігалася зворотня реакція–високий рівень метгемоглобінуобумовлював зниження рівня етанолу. Кореляційні зв’язки між вмістом метгемоглобіну та віком не було виявлено. Порівняння досліджуваних показників не виявило статевих відмінностей у екскреції етанолу, проте виявлено вікові особливості: екскреція етанолу в умовах впливу монооксиду карбону в осіб до 40 років була більш пришвидшена.Таким чином, можна стверджувати, що монооксид карбону обумовлює зміни у функціональній активності нирок.Ключові слова:гіпоксія, інтоксикація СО, кров, метгемоглобін, нирки.


1954 ◽  
Author(s):  
G.J. Alkire ◽  
R.D. Tillson ◽  
H.J. Anderson ◽  
J.L. Carroll

2014 ◽  
Vol 7 (4) ◽  
pp. 5087-5139 ◽  
Author(s):  
R. Pommrich ◽  
R. Müller ◽  
J.-U. Grooß ◽  
P. Konopka ◽  
F. Ploeger ◽  
...  

Abstract. Variations in the mixing ratio of trace gases of tropospheric origin entering the stratosphere in the tropics are of interest for assessing both troposphere to stratosphere transport fluxes in the tropics and the impact of these transport fluxes on the composition of the tropical lower stratosphere. Anomaly patterns of carbon monoxide (CO) and long-lived tracers in the lower tropical stratosphere allow conclusions about the rate and the variability of tropical upwelling to be drawn. Here, we present a simplified chemistry scheme for the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the simulation, at comparatively low numerical cost, of CO, ozone, and long-lived trace substances (CH4, N2O, CCl3F (CFC-11), CCl2F2 (CFC-12), and CO2) in the lower tropical stratosphere. For the long-lived trace substances, the boundary conditions at the surface are prescribed based on ground-based measurements in the lowest model level. The boundary condition for CO in the free troposphere is deduced from MOPITT measurements (at &amp;approx; 700–200 hPa). Due to the lack of a specific representation of mixing and convective uplift in the troposphere in this model version, enhanced CO values, in particular those resulting from convective outflow are underestimated. However, in the tropical tropopause layer and the lower tropical stratosphere, there is relatively good agreement of simulated CO with in-situ measurements (with the exception of the TROCCINOX campaign, where CO in the simulation is biased low &amp;approx; 10–20 ppbv). Further, the model results are of sufficient quality to describe large scale anomaly patterns of CO in the lower stratosphere. In particular, the zonally averaged tropical CO anomaly patterns (the so called "tape recorder" patterns) simulated by this model version of CLaMS are in good agreement with observations. The simulations show a too rapid upwelling compared to observations as a consequence of the overestimated vertical velocities in the ERA-interim reanalysis data set. Moreover, the simulated tropical anomaly patterns of N2O are in good agreement with observations. In the simulations, anomaly patterns for CH4 and CFC-11 were found to be consistent with those of N2O; for all long-lived tracers, positive anomalies are simulated because of the enhanced tropical upwelling in the easterly phase of the quasi-biennial oscillation.


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