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Simulating the release of methyl methacrylate in ALOHAe
No full textV magistrskem delu je bila izvedena simulacija nenadzorovanega izpusta metil
metakrilata, ki se je zgodil ob zaključku transporta, ko je tovornjak s cisterno snov
pripeljal do končne točke. Do nezgode je prišlo na parkirišču podjetja, ki omenjeno snov
uporablja pri svojih nadaljnjih procesih, kjer jo predeluje v končne produkte, kot so
akrilna pleksi stekla. Vzrok nenadzorovanega izhajanja snovi je bila dotrajanost materiala
na dnu rezervoarja, kjer je nastala odprtina, skozi katero je snov iztekala na tla in tam
tvorila lužo. Pri izvedbi eksperimentalnega dela sem si pomagal z uporabo programa
ALOHA, ki je za izvedbo tovrstnih simulacij zelo primeren. Program omogoča vnos vrste
nevarne snovi, ki je bila udeležena v nezgodi, prav tako omogoča izbiro med različnimi
scenariji nezgodnega dogodka, kjer pa je bil za namen magistrskega dela izbran scenarij
iztekanja snovi iz vodoravne cisterne. Poleg tega lahko v program vnesemo tudi poljubne
meteorološke podatke, ki naj bi bili prisotni na dan nezgode. V magistrskem delu je bila
simulacija izvedena za dva ločena dogodka, pri vsakem pa so bili trije možni scenariji.
Prvi dogodek je predstavljal simulacijo pri poletnih meteoroloških razmerah, drugi pa pri
zimskih meteoroloških razmerah. Omenjene razmere so bili tudi edini parameteri, ki so
se med obema simulacijama spreminjali.
Po končani simulaciji se je izkazalo, da je program ALOHA primeren za izvedbo
enostavnejših nezgodnih dogodkov, kjer je udeležena zgolj ena snov, medtem ko ne bi
bil primeren za simulacijo dogodka, kjer je udeleženih več snovi. To je tudi ena večjih
pomanjkljivosti, poleg tega, da pri izrisu območja nevarnih koncentracij in izrisu območja
toplotnega sevanja ne upošteva reliefnih razlik površja, kar tudi lahko ključno vpliva na
obseg širjenja nevarnosti. Pri vsakem nezgodnem dogodku je prišlo do izrisa nevarnih
območij, ta so bila ponazorjena z rdečo, oranžno in rumeno barvo, pri čemer so
koncentracije snovi oz. toplotno sevanje v rdečem območju najvišji, medtem ko so v
rumenem območju najnižji.
Rezultati same simulacije so si v dveh primerih, kjer je šlo za preučevanje toplotnega
sevanja na okolico, precej podobni. Torej pri scenariju BLEVE eksplozije in pri scenariju,
kjer snov izteka iz cisterne na tla, kjer pa nastane luža, ki se vname in gori kot bazenski
požar. Nekaj razlik je bilo prisotnih le pri prvem scenariju, torej ko gre za iztekanje snovi
iz cisterne prav tako na tla, le da se snov nato ne vname, ampak le izhlapeva v ozračje. V
tem primeru so območja nevarnosti, ki jih je program izrisal, nekoliko večja pri poletnih
meteoroloških razmerah, ko je bil prisoten močnejši veter.In the master thesis, an uncontrolled release of methyl methacrylate was simulated, which
occurred at the end of the transport, when the tanker truck brought the substance to its
final destination. The accident occurred in the car park of a company that uses the
substance in its downstream processes, where it is processed into end products such as
acrylic Plexiglas. The uncontrolled release of the substance was caused by deterioration
of the material at the bottom of the tank, where an opening was created through which
the substance leaked out onto the ground and formed a puddle. In carrying out the
experimental work, I used the ALOHA programme, which is very suitable for carrying
out this type of simulation. The programme allows the input of the type of hazardous
substance involved in the accident, and also allows the selection between different
accident scenarios, where for the purpose of the master\u27s thesis the scenario of a substance
leaking from a horizontal tank was chosen. In addition, any meteorological data that is
expected to be present on the day of the accident can be entered into the software. In the
master thesis, the simulation was carried out for two separate events, each with three
possible scenarios. The first event was simulated under summer meteorological
conditions and the second under winter meteorological conditions. These conditions were
also the only parameters that varied between the two simulations.
After the simulation, it turned out that ALOHA is suitable for simpler accident events
where only one substance is involved, while it would not be suitable for simulating an
event where several substances are involved. This is also one of the major drawbacks,
besides the fact that it does not take into account surface relief differences when plotting
the area of hazardous concentrations and the area of thermal radiation, which can also
have a key influence on the extent of hazard propagation. For each incident, the hazard
zones were plotted and represented in red, orange and yellow, with the highest
concentrations of substances or thermal radiation in the red zone and the lowest in the
yellow zone.
The results of the simulation itself are quite similar in the two cases where thermal
radiation to the surroundings was studied. So in the BLEVE explosion scenario and in the
scecear scenario, where the material leaks out of the tank onto the ground, where it forms
a puddle that ignites and burns like a pool fire. There were some differences only in the
first scenario, i.e. when the substance is released from the tanker also onto the ground,
except that the substance does not then ignite, but only evaporates into the atmosphere.
In this case, the hazard areas plotted by the programme are slightly larger for summer
meteorological conditions, when stronger winds were also present
Fire reporting systems and fire safety of sports facilities
No full textPojav požara v športnih objektih, kjer je prisotnih veliko število ljudi, predstavlja zelo resno grožnjo za njihova življenja, povzroča pa tudi veliko materialno škodo. Pred takšnimi situacijami se je potrebno ustrezno obvarovati z uporabo sistemov aktivne požarne zaščite znotraj objekta. Posebej pomembna je ustrezna namestitev požarnih javljalnikov v vseh prostorih, da se karseda hitro prepreči nadaljnje širjenje požara, glede na vrsto zaznavanja je pomembno, da so le-ti ustrezni, ter da so pravilno razporejeni v prostoru. Poleg javljalnikov je potrebno zagotoviti tudi ustrezno število evakuacijskih poti in ročnih gasilnikov požara ter jih označiti s predpisanimi simboli.The occurrence of fire in sports facilities, where large numbers of people are present, poses a very serious threat to their lives and also causes significant material damage. Such situations must be adequately protected by the use of active fire protection systems within the facility. It is of particular importance that fire detectors are installed in all premises in order to prevent the further spread of the fire as quickly as possible, depending on the type of detection, it is important that these are adequate and that they are properly spaced. In addition to the detectors, an adequate number of evacuation routes and manual fire extinguishers must be provided and marked with the prescribed symbols
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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