Concerning management of smoke following an accidental fire within a building it is desirable to be able to estimate, within some understood, acceptable magnitude of error, the volume of smoke resulting from the combustion process of a predefined design fire scenario. Traditionally a range of first principle-based and empirically derived correlations are used to estimate the mass flow of smoke at a height of interest within the fire plume and are based upon the understanding that the mass flow of smoke at that height is a function only of the gravitational vector within the fire system, that is to say, that induced by the pressure differential between the naturally occurring hot plume gases and the surrounding quiescent bulk fluid. The statement that the fire plume is surrounded by a quiescent bulk fluid is in itself a significant simplification and is a key assumption required to facilitate the relative simplicity of the Froude-based entrainment correlations. It is of course quite intuitive to imagine that in real accidental fire scenarios in the built environment and across an array modern infrastructure, rarely does a fire exist submerged in a passive, quiescent atmosphere. This disconnect between the natural mechanics of the buoyant fire mechanism and the surrounding fluid in which it exists was necessary when the problem of entrainment by the fire plume was first described in the mainstream engineering literature around the middle of the twentieth century. Some 25 years later as ideal entrainment mechanics were beginning to be discussed specifically for application by a field of engineering in its infancy, a few researchers in the field of fire safety engineering published data that suggested that the addition of a relatively weak cross flow to the fire plume could have a significant impact upon the rate of air entrained by the plume, and by extension, the resultant smoke mass flow rate. The data published appeared more as a brief comment on an observation made during testing. It would be easily missed, nuzzled away in the middle of a lengthy doctoral thesis. Said thesis however happens to be one of the primary pieces of work that may be cited in reference to the formulation of perhaps the best known form of the axis-symmetric fire plume entrainment correlation, that of the so-called Zukoski correlation. It is perhaps curious then that the mention of a 3-fold increase in entrainment measurements following “small disturbances” in the atmosphere during the experimental work has seemingly been ignored by researchers, probably never-learned by students, and apparently forgotten by an industry. In a fire situation smoke can limit way-finding ability, severely irritate critical soft tissue like the eyes, trachea and oesophagus, impair cognitive function, contribute to significant property damage, facilitate the transfer of heat and carcinogens to locations remote to the fire source and it is well understood that most deaths due to fire are caused by asphyxiation following smoke inhalation. Significant portions of project budgets may be spent on designing, validating, installing and maintaining smoke management systems including the use of active systems such as extraction and pressurisation, passive curtains/reservoirs and detection such aspirating, video and beam detectors. Turbulent atmospheres may arise in any manner of situations such as modern buildings with large open spaces (airports, museums), hotel foyers and those with atriums spanning many floors, hangars and storage facilities/warehouses. Strong winds are normal on offshore oil platforms, outside the window on most floors of super-tall buildings or quite simply, anywhere on a blustery day. In specific cases the extraction systems designed to remove smoke and even normal HVAC systems can cause substantial air flow over large areas. In fact, a simple compartment with an uneven distribution of ventilation points (windows/doorways) has been shown to result in a directional fire flow that results in a significantly tilted flame, essentially inducing a cross flow scenario using the natural fire alone. With the coming-of-age of computational fluid dynamics models which are now a standard tool in all commercial fire engineering design offices, and probably in every smoke modelling report, it might be argued that there is little need to revisit the hand calculations from the ground up. Accepting, however, that a cross flow may increase the rate of entrainment of a fire plume and that this challenges the fundamental principles that all previous entrainment correlation knowledge is based on, and demonstrating the outcome (in terms of plume mass flow rate) with the use of a computational model, is an entirely different thing to understanding why this happens. Smoke management is one of the core design criteria, or questions at least, in practically all fire engineering design projects. In the literature there appears to be; no work quantitatively investigating cross flow fire plume entrainment rates; no work qualitatively describing the behaviour of the flame / fire plume under the influence of a cross flow (with respect to entrainment); and certainly no work framing this paradigm in the theoretical or practical context of the impact upon modern smoke control systems. This work aims to venture into these areas in the hope of beginning to piece together the overarching story of entrainment in the cross flow fire plume. The fundamental paradigm here is the addition of cross flow inertia (a horizontal pressure differential) to the axis-symmetric case where buoyancy (a zero initial momentum, vertical pressure differential) is the sole driver of the fluid flow system. How these flows then interact in a mixed convection sequence is investigated and described in terms that are useful for practical consideration by fire safety engineers. It is hoped that the concepts postulated and the questions raised will inspire further investigation into this poorly understood, but fundamental fire safety problem.

Bakgrund: Vid de flesta kirurgiska ingrepp används diatermi. Diatermi används dels för att skära i vävnad, dels för att koagulera blodkärl, och en adekvat blodstillning är avgörande för en säkeroperation. Vid användning av diatermi utvecklas en skadlig rök, diatermirök. Trots att evidens finns för att diatermiröken innehåller skadliga ämnen som kan orsaka kroppsliga symptom, förekommer variation i användandet av rökevakueringssystem.   Syfte: Syftet med denna studie var att undersöka i vilken utsträckning rökevakueringssystem, för diatermirök, används. Vi ämnade även undersöka om det förelåg några skillnader mellan avdelningarna samt mellan de två yrkeskategorierna; operatör och operationssjuksköterska.   Metod: Operationssjuksköterskor och operatörer från nio operationsavdelningar, vid fyra sjukhus i Stockholmsregionen undersöktes i en deskriptiv tvärsnittsundersökning, med kvantitativ ansats, med ett intervjustött frågeformulär. 114 personer intervjuades, 83 operationssköterskor och 31 operatörer.   Resultat: Resultatet visade att rökevakueringssystem användes vid de flesta operationer, dock ej vid samtliga. Användningsgraden skilde sig mellan operationsavdelningar. Operationssköterskor ansåg i större utsträckning än operatörer att diatermirök kunde vara skadlig samt var mindre nöjda med åtgärderna för rökevakuering. Samtliga avdelningar saknade riktlinjer, vilket strider mot SOSFS 2011:9.   Slutsats och klinisk betydelse: För att förekomma att rökevakueringssystem och annan skyddsutrustning ej används konsekvent bör riktlinjer och rutiner framtagas. Även utbildning bör ges, till operationspersonal, eftersom okunskap kan vara en bidragande faktor till att rökevakueringssystemen ej används konsekvent. Detta kan bidra till en ökad användning vilket i sin tur leder till en förbättrad operationsmiljö för såväl personalen som för patienten. / Background: In most surgical procedures electro cautery is used. Electro cautery is used both for surgical dissection and hemostasis, and adequate hemostasis is critical for a safe operation. When using the electro cautery, a noxious smoke is developed, surgical smoke. Although evidence shows that surgical smoke contains harmful substances that can cause physical symptoms, the usage of smoke evacuation system varies.   Aim: The aims with the present study were to investigate the extent to which smoke evacuation system, for surgical plum, was used.  We further aimed to study if there were any possible differences between the surgical departments and between the two occupational categories; theatre nurses and surgeons.   Method: Operation theatre nurses and surgeons from nine surgical departments at four hospitals in the Stockholm region were studied in a descriptive cross-sectional study, with quantitative approach, and an interview supported questionnaire.   Results: The results showed that smoke evacuation system was used at most but not all surgical procedures. The use of the smoke evacuation system differed between surgical departments. A larger proportion of the theatre nurses than of the surgeons believed surgical smoke to be harmful and were less satisfied with measures to eliminate them. No surgical department had guidelines for handling surgical smoke which is in violation of SOSFS 2011:9.   Conclusion and clinical implications: To prevent that smoke evacuation systems and other protective equipment is not used consistently, policies and procedures should be derived. Education should be provided to surgical personnel, this because ignorance could be a contributing factor to the inconsistent use of smoke evacuation systems. This may contribute to an increase in usage of the device which in turn leads to an improved environment in the theater room for both the personnel as well as for the patient.

No description available.

Environmental tobacco smoke (ETS) is a serious public health threat. Residual ETS in vehicles unknowingly exposes future occupants to environmental tobacco smoke. Reducing or removing exposure to ETS has been proven to reduce long-term health complications. This quasi-experimental study investigated 5 cleaning methods and their effect on air particulate matter2.5 (PM2.5) along with the correlation between air nicotine levels and PM2.5 levels. Study variables included cleaning methods as the independent variable, and changes in air nicotine and PM2.5 levels as the dependent variables. This study is framed within primary prevention and risk reduction based on the harm reduction theory. The harm reduction theory professes that when a hazard cannot be completely removed, methods to reduce the social and personal costs associated with the hazard should be developed. Fifty vehicles were placed in 5 groups: car wash vacuumed, shop vac vacuumed, air change, hand held vacuumed, and Hepa filtration air cleaned. Nicotine and PM2.5 levels were measured before and after cleaning. A Wilcoxon ranked test analysis of the data showed all methods of cleaning studied had a statistically significant decrease in both air nicotine (Z = -6.154, p < .001) and PM2.5 levels (Z = -5.934, p < .001). Kruskall-Wallis analysis showed no statistical significance between cleaning methods. Correlation analysis determined no correlation between nicotine and PM2.5 (r value = <.3). Results of this study provides public health program professionals with information linking cleaning methods to reduction of exposure to ETS. Positive social change comes when programs are developed to training and education people to reduce their exposure, resulting in an increase in health and a decrease in medical costs.

No description available.

Within the last few decades, the prevalence of cigarette smoking has decreased because of the vast amount of research which indicates that smoking leads to health problems many of which are potentially fatal. Also, smoking harms not only those whom choose to smoke but non-smokers in the area are affected by even low levels of cigarette smoke. Thus, cigarette smoking has become a public health concern. Around the globe, countries are passing smoke-free laws in public areas such as businesses, restaurants, and bars. In the United States, many universities have enacted smoke-free campus policies to ensure the health of all their students in all places on campus. The purpose of this research is to identify the support or opposition for a smoke-free campus policy at the University of Central Florida by UCF students. A survey was distributed to undergraduate students at UCF which asks whether they would support such a policy along with characterizing questions about their smoking habits, lifestyle, history, and opinion. The analysis of the data shows that the majority of UCF student would support a smoke-free campus policy.

While the adverse health risks associated with smoking have been well-documented, few studies have examined the cardiovascular outcomes associated with secondhand smoking. The purpose of the study was to assess the distributions and association of cardiovascular diseases (CVDs) in nonsmokers exposed to secondhand smoke (SHS). Data were extracted from the National Health and Nutrition Examination Survey (NHANES) 2015-2016 cycle. Self-reported smoking status and cotinine levels were used to identify exposure groups (smokers, nonsmokers, and secondhand smokers), and medical history of several cardiovascular diseases such as coronary heart diseases and stroke were also collected via self-report survey. The association between exposure to SHS and seven cardiovascular outcomes were analyzed using chi-square analysis and odd ratios (OR) with 95% confidence intervals (CIs) were calculated using two logistic regression models. The data included 5,709 subjects including 18.5% smokers, 23.6% secondhand smokers, and 57.9% nonsmokers. There was statistically significant association between exposure to SHS and only two out of seven cardiovascular outcomes, hypertension (OR 1.554, 95% CI [1.066, 2.265]) and cholesterol levels (OR 1.213, 95% CI [1.017, 1.446]). This study is one of the first to determine an association between SHS and seven cardiovascular outcomes, thus highlighting the importance of reducing SHS exposure and can be used for further research on SHS and cardiovascular health.

No description available.

No description available.

In recent years, as control systems for boiler emissions have been upgraded, some utility sources have experienced increased plume opacity. Cases of plume opacity exceeding in-stack opacity are due to 1) the aerosol formed by condensation of primary sulfuric acid and water vapor onto polydisperse plume particles and 2) the presence of fine particles which grow into the visual size range by heterogeneous condensation and coagulation processes as the plume is cooled and diluted by mixing with the ambient air. In order to better understand the factors leading up to acid plume formation, a computer simulation model has been developed. This plume opacity model has been utilized to simulate sulfuric acid aerosol formation and growth. These processes result from homogeneous nucleation, condensation and coagulation which substantially increase the concentration of submicrometer sized aerosols. These phenomena bring about significant increases in plume opacity. Theoretical relationships have been derived and transformed into 21 computer model to predict plume opacity at various downwind distances resulting from pulverized coal combustion operations. This model consists of relatively independent components-such as an optics module, a bimodal particle size distribution module, a polydisperse coagulation module, a vapor condensation and nucleation module and a plume dispersion module-which are linked together to relate specific flue gas emissions and meterological conditions to plume opacity. This unique, near-stack, plume-opacity-model approach provides an excellent tool for understanding and dealing with such complex issues as: • increasing plume opacity observed for emissions containing sulfuric acid aerosols, • explaining the correlation between primary particle size distribution and light—scattering effects, • predicting the opacity level resulting from combustion of various coal types, • predicting control equipment effects on plume opacity. / Ph. D.