Revisionsberättelsen och dess roll att förmedla trovärdig och väsentlig information har länge varit uppe för diskussion. Kritiker menar att revisionsberättelsen har utvecklats till en alltför standardiserad rapport där det råder brist på transparens i revisionen samt att kommunikationen med intressenter är bristfällig. Detta resulterade i att IAASB, parallellt med EU, utvecklade den nya utökade revisionsberättelsen i syfte att höja dess kommunikativa värde, relevans och kvalitet. De nya direktiven trädde i kraft den 15:e december 2016 i form av sex reviderade och en helt ny standard. Den mest signifikanta förändringen är den nya standarden ISA 701 som handlar om Särskilt Betydelsefull Områden (SBO). SBO omfattar de områden som i revisorns professionella bedömning är av särskilt betydande karaktär för det reviderade företaget. Dessa områden ska vidare vara specifika för varje enskilt företag och även behandla vad som har varit mest problematiskt i revisionen. Den ytterligare informationen ska ge användarna mer insyn i revisionsprocessen och öka förståelsen för de områden som krävt betydande bedömningar.  Denna studie syftar därmed att ge en bild av hur den nya standarden gällande SBO fungerar i praktiken, vilken utformning de SBO som rapporterats har och om införandet av SBO har förändrat revisionsberättelsen sett till räkenskapsåren 2015 och 2017. För att få en bredare bild kompletteras detta med att undersöka och jämföra om revisionskvaliteten förändrats i och med den utökade revisionsberättelsen.  Med utgångspunkt i teorierna om informationsgapet och förväntningsgapet samt agentteorin undersöktes studiens syfte genom en kvantitativ innehållsanalys, där revisionsberättelser från svenska börsnoterade bolag kodats och analyserats efter framtagna kategorier. Denna information har sammanställts som deskriptiv statistik för att konkret se förändringarna mellan åren sett till bland annat längd, antal SBO och utvalda nyckelord. För att mäta revisionskvaliteten prövades istället en huvud- och tre delhypoteser genom en multipel regressionsanalys. Den data som användes som grund för både innehållsanalysen och hypotesprövningen kommer från databasen Orbis Europe och är ett register på 394 svenska börsnoterade företag.  Resultatet visar att det skett märkbara förändringar från ett år innan till ett år efter implementeringen av den utökade revisionsberättelsen. Detta i form av en längre rapport, där olika typer av SBO rapporteras i majoriteten av företagen, och där rapporten frångått sin standardiserade mall genom en större spridning på valda nyckelord. Resultatet finner däremot inte stöd för att det finns en negativ, signifikant effekt mellan den utökade revisionsberättelsen och revisionskvalitet som följd av lägre oväntade periodiseringar. Det finns dock ett stöd för att rapporteringen av SBO har en negativ, signifikant effekt på oväntade periodiseringar vilket således betyder en högre revisionskvalitet.

Särskilt Betydelsefulla Områden infördes för att öka informationsvärdet i revisionsberättelsen och bidra till en ökad insikt i revisionsbranschens arbete. Det råder dock delade meningar kring vad SBO faktiskt fyller för funktion och det finns därför ett behov av att undersöka hur SBO påverkar förekomsten av resultatjustering, vilket avgör redovisningskvaliteten. Studien visar att resultatjustering är vanligt förekommande på Stockholmsbörsen, men att den minskar vid högre omfattning av periodiseringsrelaterade SBO i revisionsberättelsen. Större andel periodiseringsrelaterade SBO indikerar alltså bättre redovisningskvalitet. / Key Audit Matters was introduced to increase the informational value of audit reports and contribute to an enhanced insight of the audit process. However, there is a difference of opinion regarding the functionality and efficiency of KAM. Therefore, there is a need to investigate how KAM impacts the extent of earnings management, which decide the accounting quality.

This thesis involves exploring enhancement of estimating the probability of a critical station blackout in nuclear power plant operations by the use of direct numerical evaluation of multidimensional nonrecovery integrals. This requires development of computational methods with data provided from South Texas Project Nuclear Operating Company (STPNOC). Several methods that are currently used in the industry to estimate such probabilities often overestimate the value substantially. The computational integral method developed in the thesis will reduce excess conservatism while maintaining plant safety standards. This computational integral is calculated using a MATLAB research code referred to generally as "STP-TAMIL" which is for South Texas Project --Texas A&M Improved LOOP. The code itself (along with the user manual) was developed in conjunction with this Thesis. STP-TAMIL is successful in reducing the estimated probability of critical station blackout by a significant amount (about 88.47 percent ) with the incorporation of recovery of offsite and onsite power for South Texas Project̕ s nuclear plants, and results were verified. This thesis also describes an asymptotic justification for to the non-recovery integral used. Applications to the industry, or STPNOC, which will use the "TAMIL" code are addressed. Some assumptions used throughout the problem suggest that if more dynamic rates or distributions are used then more recovery can be obtained, which will decrease the probability of critical station blackout. Methodology developed in this thesis will be used in future work to develop this STP-TAMIL research code into a model used industry wide in commercial nuclear power plants.

Bakgrund: ISA 701 och Särskilt Betydelsefulla Områden (SBO) infördes år 2016 med avsikten att öka informationsvärdet i revisionsberättelsen. I den svenska kontexten är SBO ett outforskat område varför denna studie ämnar bidra till en förståelse för hur revisorers användning av SBO har sett ut sedan införandet. Syfte: Syftet med studien är att utforska om det finns ett samband mellan revisionsbyrå och användning av SBO samt ta reda på om användningen har blivit likriktad över tid sedan införandet av ISA 701 år 2016. Metod: Studiens hypoteser härleds utifrån befintlig teori och tidigare kunskaper vilket innebär att en deduktiv ansats används. Hypotesprövningarna genomförs med hjälp av sekundärdata och en longitudinell forskningsdesign. Resultat: Studien finner ett samband mellan revisionsbyrå och användning av SBO. Vad gäller likriktning finns det både indikationer på att revisionsbyråerna har blivit mer lika varandra i sin användning av SBO men också på att skillnaderna har ökat. Därmed finns det en risk för att byråspecifika faktorer påverkar hur många SBO ett företag tilldelas istället för enbart klientspecifika faktorer. Kunskapsbidrag: Studien ger en tidig inblick i hur SBO har tillämpats i en svensk kontext sedan införandet år 2016. För IAASB och övriga standardsättare som varit drivande i framtagandet av SBO bidrar studien till en uppföljning av hur användningen sett ut. Ur ett investerarperspektiv kan studiens resultat bidra till en ökad medvetenhet om vilka faktorer som påverkar varför ett företag tilldelas SBO. / Background: The purpose with Key Audit Matters (KAM) is to increase the information value in the audit report. In the Swedish context, KAM is an unexplored area, which is why this study aims to contribute to an understanding of how auditors’ use of KAM has been since its introduction. Purpose: The purpose of this study is to investigate whether there is a relationship between the audit firm and the use of KAM and to find out if the use has become more uniform over time since the introduction of ISA 701 in 2016. Method: The study hypotheses have been developed through existing knowledge which means that a deductive approach has been used. The hypothesis tests have been conducted using secondary data and a longitudinal research design. Result: The study’s result indicates that there is a relationship between the audit firm and the use of KAM. In terms of uniformity, there are some indications that the differences between the audit firms’ use of KAM have decreased. However, there are also indications that the differences have increased. Thus, there is a risk that firm-specific factors affect how many KAM a company receives instead of only client-specific factors. Contribution: The study gives an early insight of how KAM has been applied in a Swedish context since the introduction 2016. For IAASB and other standard setters that have been a driving force for the development of KAM, the study contributes to a follow up of how the use of KAM has been. From an investor perspective, the results from the study can contribute to an increased awareness of which factors that affect why a company receives KAM.

Rising fuel prices have been inflating the operating costs of the fishing industry. Trawl doors are used to hold the fishing net open during trawling operations, and they have a great influence on the fuel consumption of vessels. Improvements in the design of trawl doors could therefore contribute significantly to increased fuel efficiency. An efficient optimization algorithm using two- and three-dimensional (2D and 3D) computational fluid dynamics (CFD) models is presented. Accurate CFD models, especially 3D, are computationally expensive. The direct use of traditional optimization algorithms, which often require a large number of evaluations, can therefore be prohibitive. The proposed method is iterative and uses low-order local response surface approximation models as surrogates for the expensive CFD model to reduce the number of iterations. The algorithm is applied to the design of two types of geometries: a typical modern trawl door, and a novel airfoil-shaped trawl door. The results from the 2D design optimization show that the hydrodynamic efficiency of the typical modern trawl door could be increased by 32%, and the novel airfoil-shaped trawl door by 13%. When the 2D optimum designs for the two geometries are compared, the novel airfoil-shaped trawl door results to be 320% more efficient than the optimized design of the typical modern trawl door. The 2D optimum designs were used as the initial designs for the 3D design optimization. The results from the 3D optimization show that the hydrodynamic efficiency could be increased by 6% for both the typical modern and novel airfoil-shaped trawl doors. Results from a 3D CFD analysis show that 3D flow effects are significant, where the values for drag are significantly underestimated in 2D CFD models.

Simulation-based optimization methodologies are widely applied in real world optimization problems. In developing these methodologies, beside simulation models, algorithms play a critical role. One example is an evolutionary multi objective optimization algorithm known as Reference point-based Non-dominated Sorting Genetic Algorithm-II (R-NSGA-II), which has shown to have some promising results in this regard. Its successor, R-NSGA-II-adaptive diversity control (hereafter Adaptive Epsilon-R-NSGA-II (AE-R-NSGA-II) algorithm) is one of the latest proposed extensions of the R-NSGA-II algorithm and in the early stages of its development. So far, little research exists on its applicability and usefulness, especially in real world optimization problems. This thesis evaluates behavior and performance of AE-R-NSGA-II, and to the best of our knowledge is one of its kind. To this aim, we have investigated the algorithm in two experiments, using two benchmark functions, 10 performance measures, and a behavioral characteristics analysis method. The experiments are designed to (i) assess behavior and performance of AE-R-NSGA-II, (ii) and facilitate efficient use of the algorithm in real world optimization problems. This is achieved through the algorithm parameter configuration (parametric study) according to the problem characteristics. The behavior and performance of the algorithm in terms of diversity of the solutions obtained, and their convergence to the optimal Pareto front is studied in the first experiment through manipulating a parameter of the algorithm referred to as Adaptive epsilon coefficient value (C), and in the second experiment through manipulating the Reference point (R) according to the distance between the reference point and the global Pareto front. Therefore, as one contribution of this study two new diversity performance measures (called Modified spread, and Population diversity), and the behavioral characteristics analysis method called R-NSGA-II adaptive epsilon value have been introduced and applied. They can be modified and applied for the evaluation of any reference point based algorithm such as the AE-R-NSGA-II. Additionally, this project contributed to improving the Benchmark software, for instance by identifying new features that can facilitate future research in this area. Some of the findings of the study are as follows: (i) systematic changes of C and R parameters influence the diversity and convergence of the obtained solutions (to the optimal Pareto front and to the reference point), (ii) there is a tradeoff between the diversity and convergence speed, according to the systematic changes in the settings, (iii) the proposed diversity measures and the method are applicable and useful in combination with other performance measures. Moreover, we realized that because of the unexpected abnormal behaviors of the algorithm, in some cases the results are conflicting, therefore, impossible to interpret. This shows that still further research is required to verify the applicability and usefulness of AE-R-NSGA-II in practice. The knowledge gained in this study helps improving the algorithm.

Today financial reports make up a core part of the lending process conducted by banks. In order to strengthen the information companies present, the information that the company communicates externally needs to be validated. A widely accepted way to conduct this validation is to hire an auditor that tests the information presented. In the audit report the auditor describes if the company's financial statements have been verified within reasonable certainty. A recent addition to this process is the introduction of Key Audit Matters (KAM) which was included for companies in Sweden that were of public interest.   This essay examines what part the current audit report plays for Swedish loan officers. The study examines how the introduction of KAM has been received by Swedish loan officers and if the development towards a more company specific audit report is wanted. To gain a deeper understanding we also inquired about the auditor's role more generally. We also chose to examine the loan officers' opinions regarding the current audit report and how they would like to see it develop in the future. This was conducted using a qualitative method where twelve Swedish loan officers were interviewed.   The conclusion was that Swedish loan officers currently used the audit report as a validation part in their lending process where the main focus lay in whether it was pure or not. The introduction of KAM was not found to have had any effect on the interviewed loan officers lending process. The loan officers had different opinions regarding if the auditor should be able to make more subjective statements such as KAM. All loan officers agreed that the main role of an auditor is an objective and controlling part. / I dagsläget så utgör de finansiella rapporterna som företag producerar en del av den kreditprocess som banker genomför när de ska lämna kredit. För att kunna styrka de uppgifter företaget presenterar behöver den information som företaget kommunicerar utåt valideras. Ett accepterat sätt att genomföra denna validering är att anlita en revisor som genomför en revision av de påståenden som presenteras. I revisionsberättelsen beskriver revisorn om det reviderade företagets uppgifter med rimlig säkerhet stämmer. Ett tillägg som skett på senare tid är införandet särskilt betydelsefulla områden (SBO) som trädde i kraft för svenska företag av allmänt intresse.    Den här uppsatsen undersöker vilken betydelse dagens revisionsberättelse har för kreditgivare verksamma i Sverige. Studien undersöker även hur införandet av SBO mottagits av svenska kreditgivare samt om de anser att en utveckling mot en mer företagsspecifik revisionsberättelse är något som efterfrågas. För att erhålla en djupare förståelse undersöktes även revisorns roll till banken. Vi valde även att undersöka bankens åsikter gällande revisionsberättelsen och revisorns framtid för att nyansera vår uppsats. Studiens genomfördes med hjälp av en kvalitativ metod där tolv svenska kreditgivare intervjuades.    Studiens slutsats var att svenska kreditgivare för närvarande använder revisionsberättelsen som en kontroll vid kreditgivningsprocessen där det största fokuset är på om den är ren eller oren. Införandet av SBO har än så länge ingen direkt inverkan vid bankens kreditgivningsprocess. Kreditgivarna såg olika på att ge revisorn ett större mandat att göra mer subjektiva uttalanden såsom SBO. Alla respondenter betonade dock att revisorns främsta funktion var att agera som en objektiv kontrollerande part.

The turbulent submerged jets can be found fairly frequently in a great variety of processes, their study is essential in many industrial processes and engineering applications, such as in underwater propulsion, in metallurgical processes, in chemical processes or in the nuclear industry, among others. Within the nuclear world the submerged jets can occur in light water reactors (LWR), in both pressurized water reactors (PWRs) and boiling water reactors (BWR). These submerged jets are usually associated with complex multiphase flows, so that all processes occurring after such injection will be essentially unstable and turbulent. A hypothetical severe accident in a reactor can cause deterioration of the core, so that the fission products can escape from the core and be transported through the primary system and, finally, can be released to the surrounding environment. But if there is a volume of water in the escape pathway of aerosols, a discharge in the shape of submerged jet can occur, whether in a suppression pool (during an accident with loss of power, SBO, in a water reactor boiling BWR) or in the secondary of a steam generator (in an accidental breakage sequence tube / s in U in a steam generator, SGTR, in a pressurized water reactor, PWR). So that there is a capture of aerosols in those volumes, being reduced the amount of them that escape outside. Usually these sequences have been considered only for BWRs and for low discharge velocities, but these may also take place at higher velocities and, as mentioned previously, in PWRs. Throughout this thesis there is a contribution to a better understanding and quantification of natural mitigation processes that occur when a jet is discharged into a volume of water, so that it can be applied to discharges in suppression pools in a SBO sequence (BWRs), and inside of a steam generator during a SGTR event (PWRs). Being the central activity the expansion of SPARC90 code capabilities, so as to be able to quantify the aerosol capture that occurs when the discharge takes place at high velocity (originally the code only was developed to study discharges under globular regime, i.e., injection at low velocity). So the process followed to carry out this work can be divided into several stages. The first one focuses on the literature search for available information, in a specific way on submerged jets and, given the scarce specific information, this has been extended to the literature search of processes with phenomenologies that present analogies with submerged jets. Within this part, it has on the one hand, finding aspects of jet hydrodynamics and on the other, those related to aerosol capture processes. In a second stage, there are aspects of the implementation into the new code subroutines of the expressions found and / or developed in the previous stage. While for the third stage, remains the assessment of the capabilities and behavior of the new models implemented in the code. For this last stage, first, it has been proceeded to conduct a verification process which has been tested the code robustness. And secondly, it has been proceeded to perform a validation process, which has been carried out through the comparison of the results predicted by the code against the limited experimental data that are available under similar conditions to those of the model. Being the comparison against the experimental data satisfactory, showing a marked improvement in the code capabilities. / Los chorros sumergidos turbulentos se pueden encontrar con bastante asiduidad en muy diversos procesos, siendo esencial su estudio en gran cantidad de procesos industriales y aplicaciones ingenieriles, como por ejemplo, en la propulsión submarina, en procesos metalúrgicos, en procesos químicos o en la industria nuclear, entre otros. Dentro del mundo nuclear los chorros sumergidos pueden presentarse en los reactores de agua ligera (LWR), tanto en reactores de agua a presión (PWR), como en reactores de agua en ebullición (BWR). Estos chorros sumergidos llevan asociados complejos flujos multifásicos, de forma que los procesos que tienen lugar tras dicha inyección serán esencialmente inestables y turbulentos. Un hipotético accidente grave en un reactor puede causar el deterioro del núcleo, de forma que los productos de fisión pueden escapar del núcleo y ser transportados a través del sistema primario y, finalmente, pueden ser liberados al medio ambiente circundante. Pero si existe un volumen de agua en la vía de escape de los aerosoles puede tener lugar la descarga en forma de chorro sumergido, ya sea una piscina de supresión (durante un accidente con pérdida del suministro eléctrico, SBO, en un reactor BWR) o el secundario de un generador de vapor (en una secuencia accidental con rotura de tubo/s en U en un generador de vapor, SGTR, en un reactor PWR). De forma que se tiene una captura de los aerosoles en dichos volúmenes, viéndose reducida la cantidad que escapan al exterior. Habitualmente estas secuencias se han considerado solamente para reactores BWR y para descargas a bajas velocidades, pero estas podrían tener lugar también a velocidades mayores y, como se ha dicho con anterioridad, en reactores PWR. A lo largo de esta tesis se ha contribuido a una mejor compresión y cuantificación de los procesos naturales de mitigación que se producen cuando se descarga un chorro en un volumen de agua, de forma que puede ser aplicado para descargas en piscinas de supresión en una secuencia SBO (reactores del tipo BWR), como en el interior de un generador de vapor durante una secuencia SGTR (reactores del tipo PWR). Siendo la actividad central la ampliación de las capacidades del código SPARC90, de forma que sea capaz de cuantificar la captura de aerosoles que tiene lugar cuando la descarga se produce a alta velocidad (originalmente el código solamente fue desarrollado para el estudio de descarga en régimen globular, es decir, inyección a baja velocidad). De modo que el proceso seguido para llevar a cabo el presente trabajo se puede dividir en varias etapas. La primera se centra en la búsqueda bibliográfica de la información disponible, de una forma específica relativa a chorros sumergidos y, dada la escasa información específica existente, esta se ha extendido a la búsqueda bibliográfica de procesos con fenomenologías que presentan analogías con los chorros sumergidos. Dentro de esta parte, se tiene por un lado, la búsqueda de los aspectos relativos a la hidrodinámica del chorro y, por otro, los relativos a los procesos de captura de aerosoles. En una segunda etapa se tienen los aspectos relativos a la implementación dentro de las nuevas subrutinas del código de las expresiones halladas y/o desarrolladas en la anterior etapa. Mientras que para la tercera etapa resta la evaluación de las capacidades y el comportamiento de los nuevos modelos implementados en el código. Para esta última etapa, en primer lugar, se ha procedido a llevar a cabo un proceso de verificación con el que se ha comprobado la robustez del código. Y en segundo lugar, se ha procedido a realizar un proceso de validación, el cual ha sido llevado a cabo a través de la confrontación de los resultados predichos por el código frente a los limitados datos experimentales disponibles en condiciones similares a las introducidas en el modelo. Siendo la comparación frente a los datos experimentales satisfactoria, mostrando una me / Els dolls submergits turbulents es poden trobar amb prou assiduïtat en molt diversos processos, sent essencial el seu estudi en gran quantitat de processos industrials i aplicacions enginyerils, com per exemple, en la propulsió submarina, en processos metal·lúrgics, en processos químics o en la indústria nuclear, entre altres. Dins del món nuclear els dolls submergits poden presentar-se en els reactors d'aigua lleugera (LWR), tant en reactors d'aigua a pressió (PWR), com en reactors d'aigua en ebullició (BWR). Estos dolls submergits solen portar associats complexos fluxos multifàsics, de manera que els processos que tenen lloc després de la dita injecció seran essencialment inestables i turbulents. Un hipotètic accident greu en un reactor pot causar el deteriorament del nucli, de manera que els productes de fissió poden escapar del nucli i ser transportats a través del sistema primari i, finalment, poden ser alliberats al medi ambient circumdant. Però si existeix un volum d'aigua en la via de fuita dels aerosols pot tenir lloc la descàrrega en forma de doll submergit, ja siga una piscina de supressió (durant un accident amb perduda del subministrament elèctric, SBO, en un reactor d'aigua en ebullició, BWR) o el secundari d'un generador de vapor (en una seqüència accidental amb trencament de tub/s en U en un generador de vapor, SGTR, en un reactor d'aigua a pressió, PWR). De manera que es té una captura dels aerosols en els anteriorment dits volums, veient-se reduïda la quantitat d'ells que escapen a l'exterior. Habitualment aquestes seqüències s'han considerat solament per a reactors BWR i per a baixes velocitats de descàrrega, però aquestes podrien tenir lloc també a velocitats majors i, com s'ha dit amb anterioritat, en reactors PWR. Al llarg d'aquesta tesi s'ha contribuït a una millor compressió i quantificació dels processos naturals de mitigació que es produeixen quan es descarrega un doll en un volum d'aigua, de manera que pot ser aplicat per a descàrregues en piscines de supressió en una seqüència SBO (reactors del tipus BWR), com a l'interior d'un generador de vapor durant una seqüència SGTR (reactors del tipus PWR). Sent l'activitat central l'ampliació de les capacitats del codi SPARC90, de manera que siga capaç de quantificar la captura d'aerosols que té lloc quan la descàrrega es produeix a alta velocitat (originalment el codi solament va ser desenvolupat per a l'estudi de descàrrega en règim globular, és a dir, injecció a baixa velocitat). De manera que el procés seguit per dur a terme el present treball es pot dividir en diverses etapes. La primera d'elles se centra en la cerca bibliogràfica de la informació disponible, d'una forma específica relativa a dolls submergits i, donada l'escassa informació específica existent, esta s'ha estés a la cerca bibliogràfica de processos amb fenomenologies que presenten analogies amb els dolls submergits. Dins d'aquesta part, es té d'una banda, la cerca dels aspectes relatius a la hidrodinàmica del doll i, per un altre, els relatius als processos de captura d'aerosols. En una segona etapa es tenen els aspectes relatius a la implementació dins de les noves subrutines del codi de les expressions trobades i/o desenvolupades en l'anterior etapa. Mentre que per a la tercera etapa resta l'avaluació de les capacitats i el comportament dels nous models implementats en el codi. Per a aquesta última etapa, en primer lloc, s'ha procedit a dur a terme un procés de verificació amb el qual s'ha comprovat la robustesa del codi. I en segon lloc, s'ha procedit a realitzar un procés de validació, el qual ha estat dut a terme a través de la confrontació dels resultats predits pel codi enfront de les limitades dades experimentals disponibles en condicions similars a les introduïdes en el model. Sent la comparació enfront de les dades experimentals satisfactòria, mostrant una millora ostensible en les capacitats del codi. / Berna Escriche, C. (2017). Estimation of the radioactive aerosols capture in accidental sequences of nuclear power plants [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90495

A presença de antibióticos no meio ambiente aquático tem causado crescente preocupação mundial. Além dos relatos de resistência de bactérias a antibióticos, essa classe de fármacos também pode causar efeitos tóxicos e atuar como perturbadores endócrinos em diversos organismos vivos e, possivelmente, em humanos. Dentre os antibióticos comumente usados destacam-se as sulfonamidas, detectadas em águas subterrâneas e superficiais. Os processos avançados de oxidação (POA) têm sido apontados como tecnologias eficientes para tratamento de poluentes recalcitrantes em diferentes matrizes aquosas. Dentre os POA, o processo foto-Fenton é uma alternativa para a degradação de compostos não biodegradáveis, incluindo fármacos. Uma vez que a principal limitação do processo é o intervalo de pH (2,5- 4,0), a reação pode ser vantajosamente conduzida empregando-se substâncias bio-orgânicas solúveis (BOS) como agentes complexantes de Fe3+ em condições ligeiramente ácidas (pH 5). Por sua vez, o emprego da energia ultrassônica tem sido menos estudado. Nesse contexto, o objetivo deste trabalho é estudar a degradação do antibiótico sulfadiazina (SDZ) por meio do processo foto-Fenton na presença de substâncias bio-orgânicas solúveis (UVvis/ Fe3+/H2O2/BOS) e do processo de cavitação por meio de ultrassom (US). Os resultados obtidos mostram que a sulfadiazina é eficientemente degradada por ultrassom de alta frequência. As maiores porcentagens e taxas de remoção são obtidas usando menor frequência de operação (580 kHz), maior potência dissipada e em pH ligeiramente ácido (melhor condição: pH 5,5). Além disso, a reação de Fenton, combinada com o tratamento US, melhorou notavelmente a degradação da SDZ, particularmente quando quantidades extras de H2O2 foram adicionadas ao sistema. Por sua vez, o uso de BOS como aditivos no processo foto-Fenton apresenta influência marcante na fotodegradação da SDZ em condições ligeiramente ácidas (pH 5). Os BOS podem estabilizar espécies de ferro em solução aquosa em pH próximos ao neutro, o que constitui uma propriedade de grande interesse. Sob as condições estudadas, o BOS CVT230 foi mais eficiente do que FORSUD, provavelmente devido às diferenças nos grupos funcionais presentes na composição destas substâncias. Finalmente, foram calculados os indicadores de consumo de energia elétrica por ordem de grandeza (EEO) para o processo de ultrassom (1572 kW h m-3 ordem-1) e área do coletor por ordem de grandeza (ACO) para o processo foto-Fenton (8,07 m2 m-3 ordem-1). / The potential impacts of antibiotic residues in the environment have become an emerging concern during recent years due to their relation with the development of resistant bacteria, and in some cases to their ability to cause toxic and endocrine disrupting effects in humans and other living organisms. Highlighted among the commonly used antibiotics are the sulfonamides, detected in groundwater and surface water. Advanced oxidation processes (AOP) might constitute an important alternative to deal with pharmaceuticals degradation. Among them, the photo-Fenton process has been widely used. One of its major drawbacks is the highly acidic pH needed (2,5-4,0) to avoid the formation of photochemically inactive iron oxides and hydroxides. The ability of soluble bio-organic substances (SBO) to complex metal cations such as iron is useful for the development of photo-Fenton at mild acidic conditions (pH 5). In turn, the use of ultrasonic energy has been less studied. In this context, the aim of this work is to study the degradation of the antibiotic sulfadiazine (SDZ) by the photo-Fenton process in the presence of soluble bio-organic substances (UV-vis/Fe3+/H2O2/SBO) and by ultrasonic cavitation (US). The results confirm that SDZ is effectively degraded by highfrequency ultrasound. Higher SDZ percent removals and removal rates were observed for the lowest operating frequency (580 kHz), higher dissipated power, and in slightly acidic solution (pH 5.5). On the other hand, SDZ degradation is highly improved in the case of the US/ Fe(II)/H2O2 system. The use of the SBO as Fenton additives in turn has a remarkable influence in SDZ photodegradation at slightly acid conditions (pH 5). This could be ascertained to the complexation of iron by the SBO, hence maintained in the reaction medium as a photoactive species. Under the studied conditions, the BOS CVT230 was more efficient than FORSUD, probably due to differences in the functional groups present in the composition of these substances. Finally, the figures-of merit electrical energy per order (EEO) and collector area per order (ACO) were calculated for the ultrasound (1572 kW h m-3 ordem-1) and photo-Fenton (8,07 m2 m-3 ordem-1) processes respectively.

The thesis has been performed in cooperation with a Swedish manufacturing company. The manufacturing site of the company is currently implementing a new machine layout in one of its workshops. The new layout will increase the product flow to another workshop on the site. The goal of the thesis was to evaluate the current transportation system and suggest viable alternatives for the future product flow. By means of discrete event simulation these alternative solutions would be modelled and subsequently optimized to determine if their performance is satisfactory. An approximated investment cost of the solutions would also be estimated. By performing a literature review and creating a frame of reference, a set of relevant methodologies were selected to provide a foundation to the project. Following these methodologies, the current state of transportation was identified and mapped using Value Stream Mapping. Necessary data from the current flow was identified and collected from the company computer systems. This data was deemed partly inaccurate and further verification was needed. To this end, a combination of Genchi Genbutsu, assistance from onsite engineers and a time study was used to verify the unreliable data points. The data sets from the time study and the company data which was deemed valid were represented by statistical distributions to provide input for the simulation models. Two possible solutions were picked for evaluation, an automated guided vehicle system and a tow train system. With the help of onsite personnel, a Kaizen Event was performed in which new possible routing for the future flow was evaluated. A set of simulation models portraying the automated guided vehicle system and the tow train system were developed with the aid of simulation software. The results from these models showed a low utilization of both systems. A new set of models were developed, which included all the product flows between the workshops. The new flows were modelled as generic pallets with the arrival distribution based on historical production data. This set of models were then subject for optimization with regard to the work in process and lead time of the system. The results from the optimization indicates the possibility to reduce the overall work in process by reducing certain buffer sizes while still maintaining the required throughput. These solutions were not deemed to be ready for implementation due to the low utilization of the transportation systems. The authors instead recommend expanding the scope of the system and including other product flows to reach a high utilization.