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Dissertations / Theses on the topic 'Freoner'

Author: Grafiati
Published: 4 June 2021
Last updated: 18 February 2022

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1

Nilsson, Sara. "Miljöpåverkan ur ett företagsperspektiv : En studie över ALSTOM Power Sweden AB och dess påverkan på miljö genom åren." Thesis, Linköping University, Department of Thematic Studies, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2626.

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Till att börja med var miljömedvetandet inte särskilt utbrett, varken i Sverige eller i andra delar av världen. Kunskapen om att människans aktiviteter kan ha en negativ påverkan på naturen och att naturen har gränser för hur mycket den tål är något som har växt fram under årens lopp. En hel del började hända på det här området inte minst under 1960- och 70-talen. I takt med att hänsynen till miljön fått en allt större roll i vårt samhälle har det gett ringar på vattnet även hos de svenska företagen och deras produktion.

I den här studien studeras hur ALSTOM Power Sweden AB har utvecklats inom sex olika ämnesområden, med början kring 1950-talet. Områdena är asbest, buller, trikloretylen, kemikaliehantering, freoner och oljor i avloppsvattnet. Studien har genomförts med hjälp av intervjuer med personer som tidigare arbetat på företaget samt olika dokument kopplade till detsamma. Studien visar hur hänsynstagande ur flera olika aspekter blivit allt viktigare i takt med att negativa konsekvenser i samband med användningen av olika ämnen upptäckts, både i Sverige i stort och på företaget.

Studien visar att en del av de studerade områdena har uppmärksammats som problem sedan långt tillbaka i företagets historia, medan andra till att börja med inte hanterades som något problematiskt över huvud taget. Anledningen till detta är att många av de negativa konsekvenserna tidigare inte var uppenbara. Företagets hantering av, i stort sett, vart och ett av de studerade områdena har i stor omfattning påverkats av de krav som kommit från myndigheter och lagar kopplade till miljöpåverkan. Det är dessa krav och lagar som drivit på de förbättringsåtgärder som vidtagits. Studien visar också att företaget har påverkat miljön på många sätt i olika omfattning under årens lopp, åtminstone med utgångspunkt i de sex aktuella områdena.

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2

Frydrych, Tomáš. "Zneškodňování odpadních plynů znečištěných freony." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227868.

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This thesis inquire into experimental decomposition of freon R-22 (CHClF2 - chlorodifluorometan) for different process conditions, by the help of pilot experimental unit in heavy laboratories DEPARTMENT of process and enviromental engineering Brno. This unit can decomposition waste gas, as the case may be combustion gas by the thermic oxidation or catalytic oxidation. Ground was in theoretical research, in which had been executed decomposition of freon R-22 in laboratory. In terms of experimental work were to be execution states for decomposition of freon R-22, next will be decomposition of freon R-22 by catalytic oxidation on catalyst Pt/Al2O3 and consequently this experiment will be analyse. Part of this thesis is exploration of facts basic way to decomposition of freon R-22, accounting of experimental unit and discussion of results.
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3

Knight, Christopher J. K. "Freonts in non-linear wave equations with spatial inhomogeneity." Thesis, University of Surrey, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.549460.

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4

Young, David Larry. "Noise transmission path identification in a reciprocating freon compressor." Thesis, Virginia Tech, 1995. http://hdl.handle.net/10919/40628.

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5

Ijumba, N. M. L. "Non-uniform field breakdown in mixtures of SF6̲ and freon 113." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382321.

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6

Peko, Brian Lynn. "Low energy collisions of molecular ions with hydrogen, methane, and freon." W&M ScholarWorks, 1998. https://scholarworks.wm.edu/etd/1539720307.

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Measurements of total cross sections for collision induced dissociation (CID), proton abstraction, and charge transfer have been made for the reactants H+3+H 2, He, and Ar CH+4+CD 4,H2 , and Ar, and CF+3 F++CF4,H2 and Ar for laboratory collision energies ranging from a few to 400 eV. Isotopic substitutions of the target and projectile have been made where possible to investigate any isotope effects, and in some cases to more clearly identify product ions. The purpose of this investigation is to expand the limited database of collisional processes pertinent to hydrogen, methane, and Freon discharges and their numerical modeling.;Cross sections for CID are observed to be relatively constant and CID is an important process over the energy range studied for the methane and Freon experiments. Cross sections for proton abstraction are, for the most part small ( ≤ 10 A2), and this process is important only at the lowest collision energies. The newly formed ion produced from proton abstraction for all reactants studied often has sufficient internal energy such that it may autodissociate. Charge transfer is observed for higher impact energies and cross sections for this reaction do not exceed 15 A 2. In general, production of secondary ions is observed at or near the energetic thresholds required for ground state reactants. The role of internal energy contained in the primary ion beam and its effects on the measured cross sections presented here will be addressed.;In addition to total cross sections, kinetic energy distributions have been measured for H+, H2+, and H 3+ ions present in a low pressure hydrogen discharge. These measured ion energy distributions are compared to predicted values made by a recently developed Monte Carlo simulation which necessarily incorporates the cross section measurements presented here for the H3 + + H2 system, among others. Complete agreement between theory and experiment is achieved only if measured cross sections for select CID reaction channels are arbitrarily increased by a factor of 2--3. Possible justifications for this modification, in addition to other inadequacies and further improvements that should be made to this numerical model are elaborated on. The importance and implications of all the measurements presented in this work to hydrogen, methane, and Freon discharge modeling and the yet to be realized goal of complete characterization of a molecular discharge will also be discussed.
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7

Rose, John A. "The experimental characterization of the dynamics of a reciprocating freon compressor system." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-12302008-063244/.

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8

Choukroun, Marie-Luce. "A propos d'une méthode non invasive de mesure du débit cardiaque par réinhalation d'un gaz inerte : le fréon 22." Bordeaux 2, 1988. http://www.theses.fr/1988BOR25195.

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9

Shi, Ji Quan. "Numerical modelling and experimental study of rollover in cryogenic liquids and liquid freon." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292431.

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10

Holland, Paul Edward. "Chemical interrogation of low level radioactivity." Thesis, De Montfort University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391330.

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11

Tippmann, Eric M. "Studies of carbene-solvent interactions." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1070405724.

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Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xxviii, 310 p.; also includes graphics (some col.) Includes bibliographical references (p. 181-183). Available online via OhioLINK's ETD Center
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12

Tibell, Jenny. "Hantering av isolering innehållande CFC : En granskning av kommuners tillsyn samt rivningsentreprenörers arbete." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-119833.

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The purpose of this report was to investigate why insulation containing chlorofluorocarbon (CFC) is not always recycled correctly and examine if the supervision carried out by municipalities is enough to discourage erroneous handling. Additionally the purpose was to propose actions leading to that more insulation containing CFC is recycled and that municipalities can improve their supervision. The method used was a qualitative study where one questionnaire survey was sent to Swedish municipalities and one to demolition contractors. The results from the survey shows that 70 % of municipalities rarely carry out inspections on known demolition sites. This is mainly due to lack of resources but also due to not being aware of current demolition objects. Awareness is a primary condition for inspections. Often smaller municipalities are better informed which can be a consequence of better local knowledge. The survey shows that the material inventory, which is to take place before the application for demolition is filed, often is of a poor standard and lacks sampling for CFC. Lack of knowledge is pointed out as the main reason for incorrect handling of the material. Another reason is economy since identifying and taking care of hazardous waste is expensive. The level of knowledge needs to be increased among all affected parts and one way of doing so is to improve the cooperation and communication between different parts of the municipality so that more inspections can be conducted.
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13

Gutarra, Espinoza Abel. "Estudio de Influencia del Freon (CF4) en el Electrocromismo de Películas Delgadas de Dióxido de Titanio (Tio2)." Universidad Nacional de Ingeniería. Programa Cybertesis PERÚ, 1994. http://cybertesis.uni.edu.pe/uni/1994/gutarra_ea/html/index-frames.html.

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14

Ringlander, Evelina. "Freonförbudet – Varför lyckades detta globalt och är detta tillämpbart idag på en liknande gas?" Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-174565.

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Freoner är ett stort problem för människors hälsa och andra levande organismer på grund av freons nedbrytande effekt på ozonlagret. Forskare upptäckte problemen med freon och varningar från forskningssamhället uppmärksammades av huvudproducenter av freoner samt av allmänheten då påverkan på ozonlagret ökar risken för bland annat hudcancer. Montrealprotokollet blev starten på de internationella konventioner som senare implementerades. Dock finns det ett flertal växthusgaser idag som också är ozonnedbrytande som inte ingår under någon konvention. Den globala uppvärmningen är en effekt av ökad mängd växthusgaser i atmosfären och detta kräver ett internationellt samarbete för att kunna lösas. I Montrealprotokollet ingår ODS (Ozonnedbrytande substanser) där freon innefattas. Syftet för denna studie var att belysa vad som gjorde freonförbudet lyckat, och om det är möjligt att tillämpa dessa nyckelaspekter på en av dagens växthusgaser som liknar freon. NO2 valdes för att begränsa urvalet.  Denna litteraturstudie använde sig av databaser för att finna relevanta källor genom nyckelord, därefter valdes källor utefter relevansen till frågeställningen samt att de skulle vara opartiska. Resultatet av denna studie pekar på svårigheterna med att implementera det arbetssätt som ledde till freonförbudet, på gasen NO2, som hade liknande egenskaper som freon. Detta på grund av att dagens växthusgaser är svåra att reglera utsläppet på. Växthusgaser finns globalt och det finns inte en tydlig utsläppskälla som går att reglera samt hitta ett substitut för. Korrelationen till den mänskliga hälsan och miljön, är också en nyckelaspekt till varför förbudet mot freoner var lyckat.
Freons became a large problem for society when scientists proved the ozone depletion effect, which proved to have a negative effect on human health and other living organisms. The ozone layer which was known for its protective qualities against UV-radiation lead to a new field of study, ODS (ozone depleting substances). The warnings from the scientist society and the public were eminent. The research pointed out, among other things, the increasing risk of skin cancer. This forced fast new research and several international conventions to save the ozone layer. But there are several greenhouse gases, which also have the degrading effect on the ozone layer, that are in use today. This require an international cooperation for the environment to be able to solve. The aim of this report was to illustrate why the freon ban was a success and why it would be hard to implement these key concepts on a similar present greenhouse gas. In this literature study, several databases were used to find relevant sources for the main questions and unbiased for the topic. The key aspects in this study is presented in the result section. The result pointed at the difficulties with implementing the same way of work as at the freon ban to the greenhouse gas ban. Different aspects play an important role in this, but one of the greater difficulties for implementing this is to pinpoint it to a specific source for gas emissions and finding a sustainable solution for it. The correlation between human health and environmental issues was a key factor in the freon ban.
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15

Paškauskas, Artūras. "Šilumos atgavimo funkcijos galimybių šalčio mašinose įvertinimas ir pritaikomumas Lietuvos klimatinėmis sąlygomis." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130129_192437-23743.

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Baigiamajame magistro darbe nagrinėjama tiesioginė šilumos atgavimo funkcija iš šilumos siurblio darbo ciklo ir jos pritaikomumas Lietuvos klimatinėmis sąlygomis. Apžvelgiami naudojamų šalčio mašinų tipai, technologiniai tiesioginio šilumos atgavimo inžineriniai sprendmiai. Taip pat detaliai paaiškinamas šilumos siurblio darbo ciklas ir tiesioginio šilumos atgavimo funkcijos veikimo principas. Taip pat šilumos atgavimo founkcija nagrinėjama konkrečiame jau egzistuojančiame administracinės paskirties pastate, kuriame sumontuota vandeninė šalčio mašina. Nustatomas šalčio mašinos darbo režimų grafikas skaičiuojamąjį Liepos mėnesį. Dviejomis nepriklausomomis kompiuterinėmis programomis sumodeliuojami šalčio mašinos freono konturų darbo ciklai. Pagal gautus rezultatus parenkami ir sumodeliuojami šilumos atgavimo šilumokaičiai ir randamos įmanomos atgauti šilumos galios ir šilumos kiekiai, kurie palyginami su pastato karšto vandens poreikiais ir atliekamas ekonominis šilumos atgavimo funkcijos vertinimas. Gauti rezultatai patvirtina, kad tokio tipo šilumos atgavimas didina pastato energijos vartojimo efektyvumą ir padeda taupyti pinigus. Taip pat nustatyta, kad Lietuvos klimatinėmis sąlygomis šilumos atgavimas įmanomas tik šiltuoju metų sezonu, kai pastate yra vėsos poreikis, tačiau nepaisant to, metiniai sutaupymai yra pakankamai dideli, todėl tiesioginis šilumos atgavimas yra efektyvi mikroklimato sistemų optimizavimo priemonė.
In this Master thesis a direct heat recovery option on the air cooled chiller and its availability in Lithuanian climate has been investigated. Also the review of chiller range, direct heat recovery technological issues and direct refrigerant vapor compression cycle has been explained in detail. Also the heat recovery option has been investigated in the specific administrative building with the chiller already installed. Chiller cooling chart has been calculated for the selected time period – a month of July. Chiller refrigerant circuits were modeled by using two independent computer applications. In accordance with the calcultated results, plate heat exchangers were designed. Possible amount of recovered heat was found and compared with building‘s heat demand for hot domectic water supply. The economical evaluation of heat recovery option was carried out. The results confirmed that the heat recovery option discussed in the thesis can increase energy consumption efficiency. Despite the fact that heat recovery in Lithuanina climate is only possible during the warm season, annual savings on energy consumption are sufficiently high to make the heat recovery measure an attractive option.
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16

Mantisi, Frédérick. "Perspectives quant a la penetration du co2 anthropique : utilisation des freons 11 et 12 comme traceurs des masses d'eaux oceaniques dans l'ocean indien sud ouest." Paris 6, 1989. http://www.theses.fr/1989PA066333.

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Cette these presente les premieres mesures de freons 11 et 12 obtenues au cours du programme indigo a 63 stations dans l'ocean indien ouest. La mise au point de la technique de mesure est decrite. Ces composes ont ete utilises comme traceurs de la ventilation oceanique et une analyse qualitative de celle-ci a ete entreprise dans l'ouest de l'ocean indien. Une etude quantitative de la ventilation dans le secteur ouest indien de l'ocean antarctique est egalement decrite, et une application de l'utilisation de ces composes a la comprehension de la penetration du co2 anthropique dans la meme zone est proposee. Ces traceurs se sont reveles tout a fait adaptes a cette etude, en particulier grace a leur fonction d'entree dans l'ocean qui est aisement parametrisable. De plus, ils peuvent etre mesures avec une relative facilite, avec la meme densite d'echantillonnage que l'oxygene ou la salinite, ce qui permet de connaitre leur distribution avec precision
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17

ABDELAOUI, OUAFAE. "Etude en matrice d'argon des reactions du trichlorofluoromethane (freon 11) et du trichlorobromomethane avec l'oxygene atomique genere par irradiation uv de l'ozone." Paris 6, 1993. http://www.theses.fr/1993PA066492.

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La connaissance des mecanismes de la degradation des halocarbures polluants d'origine anthropogenique dans la troposphere est d'un grand interet pour evaluer d'une part leur capacite a atteindre la stratosphere et d'autre part leur contribution a la pollution photooxydante de la basse atmosphere. L'etude des reactions bimoleculaires de cfcl#3 et de cbrcl#3 avec l'oxygene atomique en milieu condense a basse temperature presente dans ce memoire contribue ainsi a cet objectif tout en apportant des donnees essentielles sur la spectroscopie vibrationnelle des produits finaux formes. L'etude prealable des reactions sous irradiation visible et uv du chlore et du brome avec l'ozone a permis d'identifier pour la premiere fois les especes brclo et clbro formees a partir des complexes brcl:o#3 et clbr:o#3. La photodissociation de clbro a des longueurs d'onde superieures a 350 nm montre qu'il y a rupture de la liaison bro et non de la liaison clbr. La photooxydation de cbrcl#3 et de cfcl#3 conduit a un seul produit primaire, respectivement cocl#2 et cofcl. Le dichlorocarbonyl, qui se dissocie sous 280 nm en co et cl#2, est forme tant avec l'oxygene triplet p qu'avec l'oxygene singulet d, alors que la formation du chlorofluorocarbonyl n'est observee qu'avec l'oxygene a l'etat excite. Dans les deux reactions aucun intermediaire n'est mis en evidence. Les spectres vibrationnels des especes naturelles et isotopiques cocl#2, cofcl et cof#2 synthetises au laboratoire ont ete analyses en detail et cette etude a ete etendue a celle de leurs complexes avec le chlore. Des resonances de fermi entre la vibration #c#o et soit une harmonique soit une combinaison ont ete quantitativement mis en evidence, tant pour les especes monomeres que complexees. L'interaction du chlore avec les differents halogenocarbonyles apparait plus importante avec cofcl et cocl#2 qu'avec cof#2. Des calculs ab initio sur la structure des complexes completent ce travail
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18

Sweet, Susanne. "Industrial change towards environmental sustainability : the case of chloroflourocarbons." Doctoral thesis, Stockholm : Economic Research Institute, Stockholm School of Economics, (Ekonomiska forskningsinstitutet vid Handelshögsk.) (EFI), 2000. http://www.hhs.se/efi/summary/530.htm.

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19

Passos, Julio Cesar. "Étude expérimentale de l'ébullition d'un liquide sous-saturé en convection forcée." Paris 6, 1989. http://www.theses.fr/1989PA066390.

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Une étude expérimentale de l'ébullition du freon-113 sous-saturé en convection forcée a été effectuée. Deux sections d'essai ont été employées: l'une de section droite annulaire et l'autre un tube de section circulaire, caractérisées par le rapport entre la longueur et le diamètre chauffé équivalent égal à 6,2. La densité critique de flux thermique a été déterminée pour différentes conditions d'essai, définies par une pression (comprise entre 0,15 et 0,40 MPa), par une vitesse massique et par un degré de sous-saturation. Une corrélation a été déterminée en utilisant les mêmes paramètres de similitude utilisés par katto. L’écoulement a été visualisé dans les différents régimes d'ébullition et, en particulier, avant et durant la crise d'ébullition, moyennant une camera opérant entre 500 et 4000 images par seconde. Il est montré que la crise d'ébullition est une conséquence du passage de grosses inclusions de vapeur, parfois des bouchons. L’utilisation d'un asservissement électronique du courant électrique a permis de semi-stabiliser le régime de transition et, après, de stabiliser l'ébullition en film proche de l'extrémité aval du tube, tandis que dans le reste du tube le régime était celui de l'ébullition nucléée. Des mesures du taux de vide le long du tube ont été effectuées en faisant traverser l'écoulement par un faisceau de rayons gamma.
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20

Bruthans, Jiří. "Využití přirozených stopovačů (18O; 3H; freony; SF6) a dalších metod pro zhodnocení doby zdržení vod a charakteru proudění v krasových oblastech ČR." Doctoral thesis, 2006. http://www.nusl.cz/ntk/nusl-372702.

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5. CONCLUSTON -Springs in 9 se|ected areas Were studied. Areas difÍer in geo|ogy (|itho|ogy, tectonics, intensity of metamorphism), recharge intensity (móuntainous coniřa lowland areas) and intensity of karst development differing by climatic conditions, geology -Concentrated recharge is only minor importance in most of areas compared to diffuse recharge -Most of the springs (90%) show predominant infiltration during last two decades with minor content (0-30%) of water infi|trated in sixties and sevénties of the twentieth century (based on tritium content). Analysis of lBO variations in spring water indicate that contribution of short residence time component (MRT in weekš to months) is about 5-20o/o of the spring yield -These numbers are similar or somewhat lower to results of MRT studies in other karst areas in the world (mostly vast carbonate bodies), which show mean residence time of water in karst aquifers to be from several years to hundreds of years -Volume of water in catchments of particular springs based on mean yield of spring and mean residence time is in orders of units to tens of millions m3 -|n studied karst areas SFo and CFCs can give re|iab|e resu|ts. |f no data from trítium are available the residence time must be considered as a minimum age. -Mean residence time of water percolating...
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21

Richards, Graham. "Study of heat transfer in a 7-element bundle cooled with the upward flow of supercritical Freon-12." Thesis, 2012. http://hdl.handle.net/10155/228.

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Experimental data on SuperCritical-Water (SCW) cooled bundles are very limited. Major problems with performing such experiments are: 1) small number of operating SCW experimental setups and 2) difficulties in testing and experimental costs at very high pressures, temperatures and heat fluxes. However, SuperCritical Water-cooled nuclear Reactor (SCWRs) designs cannot be finalized without such data. Therefore, as a preliminary approach experiments in SCW-cooled bare tubes and in bundles cooled with SC modeling fluids can be used. One of the SC modeling fluids typically used is Freon-12 (R-12) where the critical pressure is 4.136 MPa and the critical temperature is 111.97ºC. These conditions correspond to a critical pressure of 22.064 MPa and critical temperature of 373.95ºC in water. A set of experimental data obtained in a Freon-12 cooled vertical bare bundle at the Institute of Physics and Power Engineering (IPPE, Obninsk, Russia) was analyzed. This set consisted of 20 cases of a vertically oriented 7-element bundle installed in a hexagonal flow channel. To secure the bundle in the flow channel 3 thin spacers were used. The dataset was obtained at equivalent parameters of the proposed SCWR concepts. Data was collected at pressures of about 4.65 MPa for several different combinations of wall and bulk-fluid temperatures that were below, at, or above the pseudocritical temperature. Heat fluxes ranged from 9 kW/m2 to 120 kW/m2 and mass fluxes ranged from 440 kg/m2s to 1320 kg/m2s. Also inlet temperatures ranged from 70ºC – 120ºC. The test section consisted of fuel elements that were 9.5 mm in diameter with the total heated length of 1 m. Bulk-fluid and wall temperature profiles were recorded using a combination of 8 different thermocouples.The data was analyzed with respect to its temperature profile and heat transfer coefficient along the heated length of the test section. In a previous study it was confirmed that there is the existence of three distinct regimes for forced convention with supercritical fluids. (1) Normal heat transfer; (2) Deteriorated heat transfer, characterized by higher than expected temperatures; and (3) Improved heat transfer, characterized by lower than expected temperatures. All three regions were observed for the 7 rod bundle experiments. This work compares the experimental data to predictions based upon current 1-D correlations for heat transfer in supercritical fluids. Results show that no current 1-D correlation was able to accurately predict heat transfer coefficients within ±50%. A parametric analysis of the data was also completed to determine if continuity in the experiment was present. Results of this study show that two distinct regions are present in the data. For cases with a mass flux below 1200 kg/m2s wall temperature profiles appear to be normal while in cases with mass flux above 1200 kg/m2s temperature given by the wall thermocouples were higher than normal. This phenomenon occurred regardless of heat flux-to-mass flux ratios.
UOIT
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22

Colombel, Emilie, Thierry Palermo, Loic Barré, Patrick Gateau, and Frédéric Gruy. "STUDY OF AGGLOMERATION OF ICE PARTICLES AND OF TRICHLOROFLUOROMETHANE HYDRATE PARTICLES SUSPENDED IN A HYDROCARBON PHASE." 2008. http://hdl.handle.net/2429/1196.

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This work deals with the problem of pipeline plugging by gas hydrates during oil production. Gas hydrates are crystals resulting from water and gas molecules association under high pressure and low temperature conditions. Such thermodynamical conditions are generally encountered during oil production and transport, particularly in deep offshore fields or in cold areas. Due to an agglomeration process which is still debated, hydrate occurrence can lead to plug formation. This study aims at improving the understanding in this mechanism process, in the case of water-in-oil emulsions. Therefore, ice or hydrate particle agglomeration is compared. Ice or trichlorofluoromethane (CCl3F) hydrate particles dispersed in xylene with asphaltenes as surfactant is chosen as a model system. As CCl3F hydrates are stable under atmospheric pressure, it allows us to apply different techniques without being limited by high pressure conditions. The Nuclear Magnetic Resonance (NMR) technique is used. The very different relaxation rate for solids or liquids is used to monitor in situ the ratio between solid and total hydrogen or fluorine as a function of time with controlled shearing conditions. Thus, a kinetic study is realized, that enabled to know the amount of ice formed. The apparent viscosity of the system, during crystallization and plugging, is also followed with rheometry in order to characterize agglomeration. This experimental approach allows us to highlight that physico-chemistry of interface water/oil has an important role in agglomeration. It enables us to discuss different mechanisms of agglomeration of ice and hydrate particles in a hydrocarbon phase.
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23

Laurin, Mathieu. "Recherche de la matière sombre à l’aide de détecteurs à liquides surchauffés dans le cadre de l’expérience PICO/Picasso." Thèse, 2016. http://hdl.handle.net/1866/18480.

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La matière sombre compte pour 85% de la matière composant l’univers et nous ne savons toujours pas ce qu’elle est. Depuis plusieurs années, l’expérience Picasso, maintenant devenue l’expérience PICO, tente d’élucider ce mystère. Les fréons de la famille des CXFY sont utilisés comme cibles de choix dans les détecteurs à liquides surchauffés de l’expérience PICO. Situés à SNOLab, en Ontario, ces détecteurs font parties des plus performant de la recherche de la matière sombre. Lors d’interactions de particules avec le liquide en surchauffe, un changement de phase est induit par le dépôt d’énergie engendré par l’interaction. Les bulles créées par l’évènement sont alors détectées par différents capteurs afin de déterminer le type d’interaction qui a eu lieu. Dans ce travail seront présentés les détecteurs à liquides surchauffés dans le cadre de la recherche de la matière sombre. Principalement, nous y verrons trois types de détecteurs utilisés par les expériences PICO et Picasso. Le principe de fonctionnement de chacun des détecteurs sera exposé en premier lieu ainsi que leur fabrication, puis leur mode d’opération et l’analyse des données. Les méthodes de calibration seront par la suite expliquées pour terminer avec une description des résultats obtenus démontrant la performance de ce type de détection.
Dark matter makes up 85% of the matter content of the universe and we still don’t know what it is made of. The Picasso experiment, now named PICO, has been searching for it for several years with the use of superheated liquid detectors. Following the interaction of a particle with a superheated liquid freon of the CXFY family, a bubble is formed through a phase change and is detected with several types of sensors, telling us about the nature of the event. Located at SNOLab, in Ontario, these detectors produce some of the best results in the field. The present work will go through three types of superheated liquid detectors. A full description of the working principles will be presented for each of them. In addition, the fabrication, the operation mode and the data analysis will be shown. Detector calibration techniques will then be presented with different particle sources. Finally, the most recent results will be discussed, demonstrating the performance of the superheated liquid detector technique.
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