Dissolved and Colloidal substances (DisCo) and metals are released from wood during thermomechanical pulp (TMP) production. The mechanical treatment causes that these components have a tendency to accumulate in process waters, as the water circulation systems in integrated paper mills are being closed. Disturbances such as pitch depositions on the paper machine (pitch problems), specks in the paper, decreased wet and dry strength, interference with cationic process chemicals, and impaired sheet brightness and friction properties appear in the presence of DisCo substances. The presence of transition metal ions such as manganese results in higher consumption of bleaching chemicals (hydrogen peroxide) and lowers the optical quality of the final product, and addition of complexing agents, such as EDTA or DTPA, to prevent this is needed. The never ending trends to decrease water consumption and increase process efficiency in pulp and paper production stress that it is very important both to know the effects of wood substances on pulping and papermaking and to be able to remove them in an efficient way. Carried out investigations presented in this thesis show that the lipophilic extractives can be removed from TMP press water to high extent. A 90% decrease in turbidity and a 91% removal of lipophilic extractives from TMP press water can be obtained by addition of a cationic surfactant as foaming agent during flotation. Additionally, fibres located in TMP press water are not removed with the foam fraction but purified. A retained concentration of hydrophilic extractives in the process water indicates that the flotation is selective. Moreover, by introduction of a new recoverable surface active complexing agent, a chelating surfactant, manganese ions in the form of chelates can be successfully removed from the pulp fibres and separated from the process water in the same flotation process. iii The findings presented above indicate new possibilities for internal water cleaning and decreased emissions to water if flotation technology is applied in an integrated mechanical pulp mill. / ReGain/FORE

In this project, the TMP method was employed to produce “active sites.” These active sites are for influencing and controlling the Co₃O₄ growth. One of the aims was to investigate what effect the grafting of the molecular precursor has on the nature and distribution of active sites on the various support materials. The second aim was to investigate the effect an increase in molecular precursor loading, in various impregnation steps, has on the nature and distribution of the active sites. The third aim was to investigate the effect of the steric constraints of ligand groups, by changing the molecular precursor, on the nature and distribution of active sites. The fourth aim was to use the different aspects discussed above and apply them to investigate what effect the above-mentioned modifications have on Co₃O₄ morphology. While another aim was to investigated what effect varying the quantity of Co(NO₃)₂•6H₂O has on Co₃O₄ morphology. Lastly, we investigated what effect varying the impregnation procedure and calcination temperature have on the Co₃O₄ morphology. The effect the support has on the phase of titanium molecular precursor was investigated using molecular precursor, ⁱPrOTi[OSi(O[superscript(t)]Bu₃)]₃. The supports used were Silica 922, NanoDur, Aerosil 200, Stöber spherical silica, SBA-15, mod MCM-41 and sMCM-41. The molecular precursor ⁱPrOTi[OSi(O[superscript(t)]Bu₃)]₃ was revealed to be in the orthorhombic TiO₂ with space group P(cab), normal brookite lattice, on Silica 922 after calcination but only an isolated area displaying this morphology. Generally we do not observe any TiO₂ on the support, which indicates that we have produce site-isolated sites, suggesting the TMP method has been successful on all of the various supports. The emphasis is placed on the effect of this molecular precursor and the respective support has on the Co₃O₄ morphology in Chapter 3. In this Chapter, a unique morphology was observed on Silica 922 which showed Co₃O₄ nanorods of cubic Co₃O₄ in the space group Fd-3m. Silica 922 was used for the remainder of the thesis to investigate the effect the quantity of molecular precursor has on the nature of active sites and Co₃O₄ morphology in Chapter 4. This support was also used to investigate the effect the amount of Co(NO₃)₂•6H₂O has on Co₃O₄ morphology in Chapter 5. This support was lastly used to investigate the steric constraints of the ligand groups, Ti[OSi(O[superscript(t)]Bu)₃]₄ (TiSi4), ⁱPrOTi[OSi(O[superscript(t)]Bu)₃]₃ (TiSi3), (OtBu)₃TiOSi(O[superscript(t)]Bu)₃ (TiSi) and the least sterically constrained Ti(OⁱPr)₄ has on the loading of precursor and Co₃O₄ morphology in Chapter 6.

<p>During pulp and papermaking process a huge amount of water is used. The wastewater contains a large amount of pollutants and has to be treated before it reaches the recipient. In March 2004 a new bleaching plant was started up at SCA Graphic Sundsvall AB, Ortviken’s paper mill using peroxide. The production of bleached thermo mechanical pulp and thus the load to the wastewater plant increased. During bleaching substances dissolve from the pulp and the amount of COD in the wastewater increase. To keep the efficiency of chemical and biological oxygen demand (COD, BOD) removal, the aerated lagoon is supplied by liquid oxygen. In November the same year a new pre-step including a pre-aeration, carrier and selector step was added to the existing wastewater plant. The COD-loading to the lagoon decreased and the supply of liquid oxygen was reduced.</p><p>This master thesis has been carried out at SCA Graphic Research AB, Sundsvall. The aim was to chemically characterize the wastewater with focus on the composition of carbohydrates, lignin and extractives and its influence on the biodegradability. Measurements have been carried out on total samples, suspended solids, colloidal and dissolved substances using GF/A and ultra filtration. Measurements were performed on process water from the bleaching plant and on water during the wastewater treatment process. The results show that the chemical composition of dissolved substances has a larger impact on the biodegradability than the total amount of COD. A large amount of lignin will make the wastewater harder to degrade. Suspended solids have lower biodegradability compared to the dissolved fraction. Analyzes of suspended material from the bleaching plant show a relative composition of around 41 % lignin. Analyzes done before on the dissolved fraction show a composition of 29 %. It seems that a larger amount of lignin is represented in suspended solids compared to the dissolved fraction. This can explain the low biodegradability, combined with the theory that the suspended solids are less accessible for the microorganisms. To reduce the outgoing COD the incoming flow of dissolved lignin and suspended solids to the active sludge plant has to decrease. COD in the outgoing wastewater to the recipient consists of around 90 % lignin. Extractives as saturated fatty acids, palmitic and stearic acid plus lignans (which is interpreted as a byproduct from lignin degradation) do not degrade remarkable during wastewater treatment. Flocculation of COD is one way to reduce the discharge to the recipient. Addition of 2,6 g/l PAX-18 (a high charged aluminum complex) to the wastewater from the bleaching plant gives a reduction of 40 % COD and 50 % lignin in laboratory scale and it is recommended to study further. Time related studies of BOD show that the microorganisms need five days to degrade organic material and the hydraulic retention time in the aerated lagoon has to be guaranteed.</p> / <p>Vid massa- och pappersframställning åtgår stora mängder vatten. Det processberörda avloppsvattnet innehåller mycket föroreningar varför det måste renas innan det släpps ut till recipienten. I mars 2004 startades ett nytt väteperoxidblekeri vid SCA Graphic Sundsvall AB, Ortvikens pappersbruk varvid produktionen av blekt termomekanisk massa ökade och den biologiska reningen belastades hårdare. Blekning löser ut vedämnen från massan och bidrar således till ökad mängd syreförbrukande ämnen i avloppet. För att upprätthålla reduktionen av syreförbrukande ämnen (COD, BOD) tillförs ren syrgas till den luftade dammen. I november samma år utökades den externa reningsanläggningen med ett biologiskt försteg, en s.k. multibioanläggning bestående av ett frisimmarsteg, ett bärarsteg samt ett selektorsteg. COD-belastningen in till den luftade dammen minskade och tillförseln av ren syrgas kunde reduceras.</p><p>Examensarbetet har utförts vid SCA Graphic Research AB, Sundsvall med syftet att kemiskt karaktärisera avloppsvattnets sammansättning av kolhydrater, lignin och extraktivämnen och dess inverkan på vattnets grad av biologisk nedbrytbarhet. Analyser har gjorts på totalprov, suspenderande ämnen samt kolloidalt och löst material via fraktionering med hjälp av GF/A- och ultrafiltrering. Analyser gjordes dels på processvatten från blekerierna och dels på avloppsvatten under reningsprocessen. Resultaten visar att den kemiska sammansättningen hos löst material har större inverkan på avloppsvattnets grad av nedbrytbarhet än den absoluta halten av syreförbrukande ämnen. En hög andel lignin ger ett mer svårnedbrytbart vatten. Suspenderat material är vidare mer svårnedbrytbart än de lösta fraktionerna. Analys av suspenderande substans hos blekpressat visar att andelen lignin är omkring 41 % medan arkiverade analysresultat på den lösta fasen visar ett innehåll på omkring 29 %. Det tyder alltså på en betydligt högre andel lignin i den partikulära fasen jämfört med den lösta, vilket i kombination med att materialet inte är lika lättillgängligt för mikroorganismerna kan förklara den låga bionedbrytbarheten. Om COD-utsläppet ska minskas bör inkommande flöde av löst lignin och suspenderande substans till den biologiska reningen reduceras. COD-halten i utgående avloppsvatten till recipienten utgörs av omkring 90 % lignin. De extraktivämnen som inte bryts ned är mättade fettsyror, exempelvis palmitin- och stearinsyra samt lignan, vilket antas bildas som restprodukt vid degradering av lignin. Flockning av syreförbrukande ämnen är ett sätt att gå till väga för att minska utsläppet av dessa till recipienten. Genom tillsats av 2,6 g/l PAX-18 (ett högladdat aluminiumkomplex) till blekeriavloppet kunde 40 % COD och 50 % lignin reduceras. Flockningsförsöket är gjort i laboratorieskala vid rumstemperatur och ytterligare utvärdering rekommenderas. Tidsstudier av BOD visar att mikroorganismerna behöver fem dagars uppehållstid för att hinna bryta ned organiskt material i avloppsvattnet, varför omloppstiden i den luftade lagunen inte bör understiga denna tidsrymd.</p>

During pulp and papermaking process a huge amount of water is used. The wastewater contains a large amount of pollutants and has to be treated before it reaches the recipient. In March 2004 a new bleaching plant was started up at SCA Graphic Sundsvall AB, Ortviken’s paper mill using peroxide. The production of bleached thermo mechanical pulp and thus the load to the wastewater plant increased. During bleaching substances dissolve from the pulp and the amount of COD in the wastewater increase. To keep the efficiency of chemical and biological oxygen demand (COD, BOD) removal, the aerated lagoon is supplied by liquid oxygen. In November the same year a new pre-step including a pre-aeration, carrier and selector step was added to the existing wastewater plant. The COD-loading to the lagoon decreased and the supply of liquid oxygen was reduced. This master thesis has been carried out at SCA Graphic Research AB, Sundsvall. The aim was to chemically characterize the wastewater with focus on the composition of carbohydrates, lignin and extractives and its influence on the biodegradability. Measurements have been carried out on total samples, suspended solids, colloidal and dissolved substances using GF/A and ultra filtration. Measurements were performed on process water from the bleaching plant and on water during the wastewater treatment process. The results show that the chemical composition of dissolved substances has a larger impact on the biodegradability than the total amount of COD. A large amount of lignin will make the wastewater harder to degrade. Suspended solids have lower biodegradability compared to the dissolved fraction. Analyzes of suspended material from the bleaching plant show a relative composition of around 41 % lignin. Analyzes done before on the dissolved fraction show a composition of 29 %. It seems that a larger amount of lignin is represented in suspended solids compared to the dissolved fraction. This can explain the low biodegradability, combined with the theory that the suspended solids are less accessible for the microorganisms. To reduce the outgoing COD the incoming flow of dissolved lignin and suspended solids to the active sludge plant has to decrease. COD in the outgoing wastewater to the recipient consists of around 90 % lignin. Extractives as saturated fatty acids, palmitic and stearic acid plus lignans (which is interpreted as a byproduct from lignin degradation) do not degrade remarkable during wastewater treatment. Flocculation of COD is one way to reduce the discharge to the recipient. Addition of 2,6 g/l PAX-18 (a high charged aluminum complex) to the wastewater from the bleaching plant gives a reduction of 40 % COD and 50 % lignin in laboratory scale and it is recommended to study further. Time related studies of BOD show that the microorganisms need five days to degrade organic material and the hydraulic retention time in the aerated lagoon has to be guaranteed. / Vid massa- och pappersframställning åtgår stora mängder vatten. Det processberörda avloppsvattnet innehåller mycket föroreningar varför det måste renas innan det släpps ut till recipienten. I mars 2004 startades ett nytt väteperoxidblekeri vid SCA Graphic Sundsvall AB, Ortvikens pappersbruk varvid produktionen av blekt termomekanisk massa ökade och den biologiska reningen belastades hårdare. Blekning löser ut vedämnen från massan och bidrar således till ökad mängd syreförbrukande ämnen i avloppet. För att upprätthålla reduktionen av syreförbrukande ämnen (COD, BOD) tillförs ren syrgas till den luftade dammen. I november samma år utökades den externa reningsanläggningen med ett biologiskt försteg, en s.k. multibioanläggning bestående av ett frisimmarsteg, ett bärarsteg samt ett selektorsteg. COD-belastningen in till den luftade dammen minskade och tillförseln av ren syrgas kunde reduceras. Examensarbetet har utförts vid SCA Graphic Research AB, Sundsvall med syftet att kemiskt karaktärisera avloppsvattnets sammansättning av kolhydrater, lignin och extraktivämnen och dess inverkan på vattnets grad av biologisk nedbrytbarhet. Analyser har gjorts på totalprov, suspenderande ämnen samt kolloidalt och löst material via fraktionering med hjälp av GF/A- och ultrafiltrering. Analyser gjordes dels på processvatten från blekerierna och dels på avloppsvatten under reningsprocessen. Resultaten visar att den kemiska sammansättningen hos löst material har större inverkan på avloppsvattnets grad av nedbrytbarhet än den absoluta halten av syreförbrukande ämnen. En hög andel lignin ger ett mer svårnedbrytbart vatten. Suspenderat material är vidare mer svårnedbrytbart än de lösta fraktionerna. Analys av suspenderande substans hos blekpressat visar att andelen lignin är omkring 41 % medan arkiverade analysresultat på den lösta fasen visar ett innehåll på omkring 29 %. Det tyder alltså på en betydligt högre andel lignin i den partikulära fasen jämfört med den lösta, vilket i kombination med att materialet inte är lika lättillgängligt för mikroorganismerna kan förklara den låga bionedbrytbarheten. Om COD-utsläppet ska minskas bör inkommande flöde av löst lignin och suspenderande substans till den biologiska reningen reduceras. COD-halten i utgående avloppsvatten till recipienten utgörs av omkring 90 % lignin. De extraktivämnen som inte bryts ned är mättade fettsyror, exempelvis palmitin- och stearinsyra samt lignan, vilket antas bildas som restprodukt vid degradering av lignin. Flockning av syreförbrukande ämnen är ett sätt att gå till väga för att minska utsläppet av dessa till recipienten. Genom tillsats av 2,6 g/l PAX-18 (ett högladdat aluminiumkomplex) till blekeriavloppet kunde 40 % COD och 50 % lignin reduceras. Flockningsförsöket är gjort i laboratorieskala vid rumstemperatur och ytterligare utvärdering rekommenderas. Tidsstudier av BOD visar att mikroorganismerna behöver fem dagars uppehållstid för att hinna bryta ned organiskt material i avloppsvattnet, varför omloppstiden i den luftade lagunen inte bör understiga denna tidsrymd.

The mechanical pulping industry has been developing throughout the years, due to competitive prices in the electricity market and good accessibility of wood. This has made it possible for such and “expensive” process to further develop. Today, with increasing electricity prizes, it is of great interest to reduce electrical consumption in mechanical pulping industry, since the process consumes large amounts of electricity. Braviken paper mill is starting up a new thermomechanical pulping line, scheduled for start-up in August 2008, which aims to reduce electrical consumption. The new line will include chip pre-treatment equipment such as an impregnator, an Andrtiz Impressafiner (Screw press), a high intensity primary stage refines double disc (DD), and a new low consistency refiner (LC), significantly bigger than those earlier available on the market. This master´s thesis is one out of three Master´s thesis made at Braviken paper mill during spring 2008. They all are connected, and are investigating the possibility to reduce electric energy consumption within TMP production. Master´s thesis concerning high consistency refining was done by Dino Muhic, “High consistency refining of mechanical pulps during varying refining conditions”, and low consistency refining written by Fredrik Johansson “Increased energy efficiency in low consistency refining”. Chip pre-treatment is to be used to reduce electrical consumption. Mechanical pre-treatment, such as using an Andrtiz Impressafiner demolishes the chips while also making it possible to impregnate the chips with chemicals, the later giving additional possibilities to reduce electricity consumption. Chemical chip pre-treatment decreases the lignin softening temperature, which benefits the refining process, yielding longer and less damaged fibers that will create a fibrous pulp with reduced electrical energy input.The goal for this study was to investigate the effect of alkaline-peroxide on chip pre-treatment by using a design of experiment method, in terms of electric energy consumption for the process, strength properties, opacity and ISO-brightness within the pulp/sheets. The trials were built up as a factorial experiment, with two factors, alkaline and peroxide, with two levels each (high and low). The high level for alkaline was 15 kg/t and 10 kg/t for the low level, and the high level for peroxide was 10 kg/t and 5 kg/t for the low level. This resulted in four trials with two zero-points, and two reference pulps, one normal TMP, thermomechanical pulp, and the other TMP with pressafiner and water. The trials showed that adding alkaline-peroxide clearly had an impact on pulp properties, such as increased strength properties, fiber length improvements and less shives could be found in the alkaline-peroxide treated pulps. The yield was highest for the normal TMP, about 99% and it decreased with increasing alkaline addition, the lowest value was achieved for the pulps containing the highest dose of alkaline, about 95%. The optical properties were more or less as expected. Opacity had the highest value for the pulps that had been made from chips with the highest total alkaline level. The ISO brightness was highest for pulps containing low level of alkaline. It could not be decided if the electricity demand had been reduced for the chemically treated pulps; it actually had the opposite effect as expected. The chemically treated pulps demanded a higher SEC, specific energy consumption, compared to the reference pulps. This result could have depended on the small pilot plant high consistency refiners at CTP, Centre technique du papier, Grenoble, France, due to the plate size and what kind of plats that were used. To do trials like this and to be able to draw correct conclusions relevant for a full scale plant, bigger refiners might give a more comparable result. It was clear that the fiber properties had improved, which could be the key to reduce electricity when LE- (low-energy) plates are used in the HC-refiner. A higher intensity could be used and electricity energy could be saved.

<p> </p><p><p>The mechanical pulping industry has been developing throughout the years, due to competitive prices in the electricity market and good accessibility of wood. This has made it possible for such and “expensive” process to further develop. Today, with increasing electricity prizes, it is of great interest to reduce electrical consumption in mechanical pulping industry, since the process consumes large amounts of electricity. Braviken paper mill is starting up a new thermomechanical pulping line, scheduled for start-up in August 2008, which aims to reduce electrical consumption. The new line will include chip pre-treatment equipment such as an impregnator, an Andrtiz Impressafiner (Screw press), a high intensity primary stage refines double disc (DD), and a new low consistency refiner (LC), significantly bigger than those earlier available on the market. This master´s thesis is one out of three Master´s thesis made at Braviken paper mill during spring 2008. They all are connected, and are investigating the possibility to reduce electric energy consumption within TMP production. Master´s thesis concerning high consistency refining was done by Dino Muhic, “<em>High consistency refining of mechanical pulps during varying refining conditions</em>”, and low consistency refining written by Fredrik Johansson “I<em>ncreased energy efficiency in low consistency refining</em>”.</p><p><p>Chip pre-treatment is to be used to reduce electrical consumption. Mechanical pre-treatment, such as using an Andrtiz Impressafiner demolishes the chips while also making it possible to impregnate the chips with chemicals, the later giving additional possibilities to reduce electricity consumption. Chemical chip pre-treatment decreases the lignin softening temperature, which benefits the refining process, yielding longer and less damaged fibers that will create a fibrous pulp with reduced electrical energy input.The goal for this study was to investigate the effect of alkaline-peroxide on chip pre-treatment by using a design of experiment method, in terms of electric energy consumption for the process, strength properties, opacity and ISO-brightness within the pulp/sheets. The trials were built up as a factorial experiment, with two factors, alkaline and peroxide, with two levels each (high and low). The high level for alkaline was 15 kg/t and 10 kg/t for the low level, and the high level for peroxide was 10 kg/t and 5 kg/t for the low level. This resulted in four trials with two zero-points, and two reference pulps, one normal TMP, thermomechanical pulp, and the other TMP with pressafiner and water.</p><p>The trials showed that adding alkaline-peroxide clearly had an impact on pulp properties, such as increased strength properties, fiber length improvements and less shives could be found in the alkaline-peroxide treated pulps. The yield was highest for the normal TMP, about 99% and it decreased with increasing alkaline addition, the lowest value was achieved for the pulps containing the highest dose of alkaline, about 95%. The optical properties were more or less as expected. Opacity had the highest value for the pulps that had been made from chips with the highest total alkaline level. The ISO brightness was highest for pulps containing low level of alkaline. It could not be decided if the electricity demand had been reduced for the chemically treated pulps; it actually had the opposite effect as expected. The chemically treated pulps demanded a higher SEC, specific energy consumption, compared to the reference pulps. This result could have depended on the small pilot plant high consistency refiners at CTP, Centre technique du papier, Grenoble, France, due to the plate size and what kind of plats that were used. To do trials like this and to be able to draw correct conclusions relevant for a full scale plant, bigger refiners might give a more comparable result. It was clear that the fiber properties had improved, which could be the key to reduce electricity when LE- (low-energy) plates are used in the HC-refiner. A higher intensity could be used and electricity energy could be saved.</p></p></p>

Dissolved and Colloidal substances (DSC) and metals are released from woodduring thermomechanical pulp (TMP) production. These components have atendency to accumulate in process waters, as the water circulation systems inintegrated paper mills are closed. Disturbances such as pitch depositions in thepaper machine (pitch problems), specks in the paper, decreased wet and drystrength, interference with cationic process chemicals, and impaired sheetbrightness and friction properties appear when DSC are present. Transition metalions such as manganese results in higher consumption of bleaching chemicals(hydrogen peroxide) and lowers the optical quality of the final product, andaddition of complexing agents, such as EDTA or DTPA, to prevent this is needed.The never ending trends to decrease water consumption and increase processefficiency in pulp and paper production emphasizes that it is very important bothto know the effects of wood substances on pulping and papermaking and to beable to remove them in an efficient way. From a biorefinery point of view, DSCcomponents can be promising renewable raw materials for biofuels, bio‐basedchemicals and materials.In this thesis, a new approach using induced air flotation (IAF) without a cationicpolyelectrolyte addition for the removal of pitch and metal ions from mechanicalpulp mill process waters is presented. The induced air flotation of different processwaters is facilitated by the addition of a chelating surfactant and different foamingagents. The influence of the pH value, temperature and foaming agentconcentration on the flotation efficiency has been investigated. The investigations presented show that the disturbing components can be removed from TMP presswater to a high extent. A 90% decrease in turbidity and a 91% removal of lipophilicextractives (i.e. resin and fatty acids, triglycerides, sterols and steryl esters) fromunbleached and bleached TMP process water can be obtained by addition of acationic surfactant as foaming agent during flotation. Lower amount of foamingagent is needed to purify efficiently bleached TMP process water, than unbleached.Additionally, fibres located in TMP press water are not removed with the foamfraction but purified. A retained concentration of hydrophilic extractives (i.e.hemicelluloses and lignans) in the process water indicates that the flotation isselective. Moreover, by introduction of a new recoverable surface activecomplexing agent, a chelating surfactant, manganese ions in the form of chelatescan be successfully removed from the pulp fibres and separated from the processwater in the same flotation process. Furthermore, from the purified unbleachedTMP process water a 90% recovery of dissolved hemicelluloses by anti‐solventprecipitation was obtained.The findings presented above indicate new possibilities for the internal watercleaning stage to decrease DSC emissions to recipient and for recovery of valuableraw materials from purified process water if flotation technology is applied in anintegrated mechanical pulp mill. / FORE

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-06T23:52:19Z No. of bitstreams: 1 GeorgiaCristianeRodrigues_DISSERT.pdf: 1144525 bytes, checksum: 66ce070fef2718c5900fbdb9e7231c3b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-09T19:56:30Z (GMT) No. of bitstreams: 1 GeorgiaCristianeRodrigues_DISSERT.pdf: 1144525 bytes, checksum: 66ce070fef2718c5900fbdb9e7231c3b (MD5) / Made available in DSpace on 2016-05-09T19:56:30Z (GMT). No. of bitstreams: 1 GeorgiaCristianeRodrigues_DISSERT.pdf: 1144525 bytes, checksum: 66ce070fef2718c5900fbdb9e7231c3b (MD5) Previous issue date: 2015-09-11 / O avan?o da tecnologia m?vel, no que diz respeito ? disponibilidade de servi?os 3G/4G e da utiliza??o de Dispositivos como Smartphones e Tablets originou um novo fen?meno de comunica??o: BYOD (Bring Your Own Device), ? uma nova tend?ncia de neg?cios, onde os funcion?rios est?o utilizando seus pr?prios dispositivos para fins de trabalho. A r?pida expans?o de BYOD e as quest?es de seguran?a e privacidade de dados representam desafios significativos para as organiza??es. A resposta mais comum a essas preocupa??es ? a ado??o de pol?ticas corporativas que regem BYOD. Este estudo tem por objetivo analisar a inten??o dos funcion?rios em cumprir com a pol?tica de seguran?a da organiza??o no contexto de BYOD, quando os funcion?rios utilizam seus dispositivos pessoais para acessar recursos organizacionais para realizarem o trabalho, dentro ou fora do ambiente organizacional. Para tanto, foi utilizada a Teoria de Motiva??o a Prote??o (TMP) como embasamento te?rico. Em termos metodol?gicos, a presente pesquisa, ? do tipo descritiva e tamb?m explorat?ria com uma abordagem quantitativa. N?o aleat?ria ? o tipo de amostragem. Para coleta, foi aplicado um question?rio estruturado, tipo survey, com um conjunto de itens de medi??o para cada construto. A etapa de an?lise dos dados foi realizada por meio de utiliza??o de t?cnicas de estat?stica descritiva e an?lise multivariada, tais como a An?lise Fatorial Explorat?ria (AFE) e a Regress?o Linear M?ltipla (RLM). Do ponto de vista te?rico, os resultados demonstram que o modelo PMT fornece uma base te?rica s?lida para a investiga??o nesta ?rea. No entanto, os resultados tamb?m indicam que este modelo ? afetado por fatores contextuais, e que a escolha da amostra pode influenciar a import?ncia dos diferentes componentes do modelo. Portanto, o cuidado deve ser tomado na generaliza??o desses resultados para outros contextos e popula??es / The advancement of mobile technology, with regard to the availability of 3G / 4G and use of devices such as Smartphones and Tablets yielded a new communication phenomenon: BYOD (Bring Your Own Device), is a new business trend, where employees are using their own devices for work purposes. The rapid expansion of BYOD , data security and privacy issues pose significant challenges for organizations. The most common response to these concerns is the adoption of corporate policies governing BYOD. This study aims to analyze the intention of employees to comply with the organization's security policy in the context of BYOD, when employees use their personal devices to access organizational resources to develop work related tasks, inside or outside the organizational environment. Therefore, we will use the Motivation Theory Protection as theoretical basis. In terms of methodology, this research will be a descriptive and exploratory study with a quantitative approach. Nonrandom will be the type of sampling. For collection, a structured questionnaire, survey type, with a set of measurement items for each construct is applied. The data analysis step is performed by means of descriptive statistics, Exploratory Factor Analysis and Multiple Linear Regression. From a theoretical point of view, the results demonstrate that the PMT model provides a solid theoretical basis for research in this area. However, the results also suggest that this model is affected by contextual factors, and the selection of the sample may influence the importance of the different components of the model. Therefore, caution should be taken in generalizing these results to other settings and populations.

Objectif: L'objectif primaire de cette étude était d'évaluer la validité, la fiabilité et la reproductibilité des mesures dentaires obtenues sur les modèles digitaux iTero (Align Technology, San Jose, Californie) et Unitek TMP Digital (3M, Monrovia, Californie) en comparaison avec celles obtenues sur les modèles de plâtre (gold standard). L'objectif secondaire était de comparer les deux différents matériaux à empreinte (l'alginate et le polyvinylsiloxane-PVS) afin de déterminer si le choix du matériau affectait la précision des mesures. Méthodes: Le premier volet de l'étude impliquait les modèles digitaux Unitek et iTero, obtenus à partir de 25 paires de modèles de plâtre choisis de façon randomisée et provenant de la pratique privée d'un des co-auteurs. Des empreintes d'alginate et de PVS ont été prises sur les modèles de plâtre et numérisées par le scanner Unitek. Les modèles ont ensuite été numérisés avec le scanner iTero. Le deuxième volet de l'étude cherchait à comparer les modèles digitaux iTero (numérisation intra-orale) avec les modèles de plâtre (empreintes d'alginate et de PVS) obtenus à partir de 25 patients de la clinique d'orthodontie de l'Université de Montréal ayant besoin d'un traitement orthodontique. Dans les deux volets de l'étude, deux auteurs ont pris les mesures suivantes sur les différents modèles: largeur mésio-distale de chaque dent de la première molaire à l'autre première molaire, le périmètre d'arcade, les distances intermolaire et intercanine, le surplomb vertical et le surplomb horizontal. Les ratios et excès Bolton 6 et 12, l'espace requis et les différentiels d'espace au maxillaire et à la mandibule, ont été calculés. Résultats: La fiabilité (ICC) entre les modèles digitaux (Unitek et iTero) et les modèles de plâtre était bonne à excellente pour toutes les mesures [ICC=0,762–0,998], et la fiabilité entre les deux matériaux à empreinte était excellente [ICC=0,947–0,996]. Dans les deux volets de l'étude, les mesures faites sur les modèles iTero étaient généralement plus grandes que celles faites sur les modèles de plâtre. Les plus grandes différences moyennes pour la comparaison iTero-plâtre étaient trouvées au niveau de l'espace disponible au maxillaire et à la mandibule (systématiquement plus grande pour cette variable), soit 2,24 mm et 2,02 mm respectivement dans le premier volet, et 1,17 mm et 1,39 mm respectivement dans le deuxième volet. Les différences étaient considérées cliniquement non significatives pour toutes les variables. La reproductibilité intra-examinateur était bonne à excellente pour les modèles de plâtre et les modèles digitaux, à l'exception du différentiel d'espace à la mandibule pour les modèles Unitek [ICC=0,690-0,692]. La reproductibilité inter-examinateur était bonne à excellente pour les modèles de plâtre et les modèles digitaux dans les deux volets de l'étude, mais acceptable à modérée pour les modèles Unitek au niveau des analyses Bolton 6 et 12, et des différentiels d'espace au maxillaire et à la mandibule [ICC=0,362-0,548]. Conclusions: La précision et la fiabilité des mesures dentaires faites sur les modèles digitaux Unitek et iTero étaient cliniquement acceptables et reproductibles en comparaison avec les celles faites sur les modèles de plâtre. Le choix de matériel à empreinte entre l'alginate et le PVS n'affectait pas la précision des mesures. Cette étude semble démontrer que les modèles digitaux Unitek et iTero, utilisés avec leur logiciel respectif, sont une alternative fiable et reproductible aux modèles de plâtre pour le diagnostic et l’analyse des modèles orthodontiques. / Objective: The primary objective of this study was to evaluate the validity, reliability and reproducibility of dental measurements obtained on digital models produced by iTero (Align Technology, San Jose, California) and by Unitek TMP Digital (3M, Monrovia, California) in comparison with those obtained on plaster models (gold standard). The secondary objective was to compare two different impression materials (alginate and polyvinylsiloxane-PVS) to determine whether the material used affects accuracy of the measurements. Methods: The first part of the study involved Unitek and iTero digital models, which were all obtained from 25 pairs of plaster models randomly selected from one of the co-author's private practice. Alginate and PVS impressions were taken on plaster models and were scanned by the Unitek scanner. The same models were then scanned with the iTero scanner. The second part of the study sought to compare iTero digital models (intraoral scans) with plaster models (alginate and PVS impressions) taken on 25 patients requiring treatment from the Orthodontic clinic of the University of Montreal. In both parts of the study, two authors took the following measurements on the different models: mesio-distal width of each tooth from first molar to the other first molar, intermolar and intercanine distances, overbite and overjet. Bolton 6 and 12 ratios and excesses, maxillary and mandibular space available and required were also calculated in order to determine space differentials. Results: A good to excellent reliability (ICC) was found for all measurements when comparing digital (Unitek and iTero) and plaster models [ICC=0.762–0.998], and excellent reliability when comparing both impression materials [ICC=0.947–0.996]. In the two parts of the study, measurements on iTero models were generally larger than on plaster models. Highest mean differences for iTero-plaster were found for maxillary space available and mandibular space available (systematically larger for that variable): 2.24 mm and 2.02 mm respectively in the first part of the study, 1.17 mm and 1.39 mm respectively in the second part. Differences were considered clinically insignificant for all variables. Intraexaminer reproducibility was good to excellent for plaster and digital models, except for mandibular space differential on Unitek models [ICC=0.690-0.692]. Interexaminer reproducibility was good to excellent for plaster and digital models in both parts of study, but fair to moderate for Unitek models regarding Bolton 6 and 12, and maxillary and mandibular space differentials [ICC=0.362-0.548]. Conclusions: The accuracy and reliability of dental measurements done on Unitek and iTero digital models were clinically acceptable and reproducible when compared with measurements done on traditional plaster models. The choice of impression material between alginate and PVS did not affect accuracy of the measurements. This study tends to indicate that Unitek and iTero digital models examined with their associated software can be reliably used for orthodontic cast analysis and diagnosis.

This thesis is focused on the novel wood chip refining process called AdvancedThermomechanical Pulp (ATMP) refining. ATMP consists of mechanical pretreatmentof chips in Impressafiner and Fiberizer prior to first stage refining atincreased intensity. Process chemicals (this study was concentrated on hydrogenperoxide and magnesium hydroxide) are introduced into the first stage refiner.It is known that the use of chemicals in TMP process and first stage refining atelevated intensity can reduce the energy demands of refining. The downside is thatthey also alter the character of the produced pulp. Reductions in fibre length andtear index are usually the consequences of refining at elevated intensity. Additionof chemicals usually leads to reduction of the light scattering coefficient. Usingstatistical methods it was shown that it is possible to maintain the TMP character ofthe pulp using the ATMP process. This is explained by a separation of thedefibration and the fibre development phases in refining. This separation allowsdefibration of chips to fibres and fibre bundles without addition of chemicals orincrease in refining intensity. Chemicals are applied in the fibre developmentphase only (first stage refiner). The energy demand in refining to reach tensileindex of 25 Nm/g was reduced by up to 1.1 MWh/odt (42 %) using the ATMPprocess on Loblolly pine. The energy demand in refining of White spruce, requiredto reach tensile index of 30 Nm/g, was reduced by 0.65 MWh/odt (37%).Characterizations of individual fibre properties, properties of sheets made fromlong fibre fractions and model fibre sheets with different fines fractions werecarried out. It was established that both the process equipment configuration (i.e.the mechanical pre‐treatment and the elevated refining intensity) and the additionof process chemicals in the ATMP process influence fibre properties such as external and internal fibrillation as well as the amount of split fibres. Improvementof these properties translated into improved properties of sheets, made from thelong fibre fractions of the studied pulps. The quality of the fines fraction alsoimproved. However, the mechanisms of improvement in the fines quality seem tobe different for fines, generated using improved process configuration andaddition of process chemicals. The first type of fines contributed to better bondingof model long fibre sheets through the densification of the structure. Fines whichhave been influenced by the addition of the process chemicals seemed in additionto improve bonding between long fibres by enhancing the specific bond strength.The improved fibre and fines properties also translated into better airpermeability and surface roughness of paper sheets, properties which areespecially important for supercalendered (SC) printing paper. The magnitude offibre roughening after moistening was mainly influenced by the processequipment configuration while the addition of process chemicals yielded lowestfinal surface roughness due to the lowest initial surface roughness. There was nodifference in how fines fractions from the studied processes influenced the fibreroughening. However, fines with better bonding yielded model fibre sheets withhigher PPS, probably due to their consolidation around fibre joints. Hence, thedecrease in PPS can probably be attributed to the improvements in the long fibrefraction properties while the improvement of fines quality contributed to thereduction of air permeability.The process chemicals, utilized in the ATMP process (Mg(OH)2 and H2O2) alsoproved to be an effective bleaching system. Comparable increases in brightnesscould be reached using the ATMP process and conventional tower bleaching.Maximum brightness of the pulp was reached after approximately 10 minutes ofhigh‐consistency storage after refining or 40 minutes of conventional bleaching.This study was conducted using a pilot scale refiner system operated as a batchprocess. Most of the experiments were performed using White spruce (Piceaglauca). In Paper I, Loblolly pine (Pinus taeda) was used. It is believed that theresults presented in this thesis are valid for other softwood raw materials as well,but this limitation should be considered.