Den svenska byggindustrin spelar en betydande roll för landets koldioxidutsläpp och avfallsproduktion. År 2016 stod den för nästan en femtedel av de totala växthusgasutsläppen och genererade upp till 9,8 miljoner ton avfall. För att minska klimatpåverkan från nybyggen har byggbranschen antagit en plan som inkluderar minskad materialanvändning och val av mer hållbara material. I januari 2022 trädde en ny lag i kraft som kräver klimatdeklaration för byggnader. Lagens syfte är att minska klimatpåverkan från nybyggen och projekt med bygglov genom att öka byggherrens medvetenhet. Den nya lagen kräver endast en livscykelanalys från vagga till grind.  I denna studie utförs en livscykelanalys, LCA, i syfte att undersöka klimatpåverkan, försurning och övergödning  per ton rivningsvirke från demontering till och med sluthantering, från grind till grav. Det undersöks även var i kedjan från grind till grav som de tre miljöpåverkanskategorierna är som störst och vilka möjligheter som finns att minska miljöpåverkan vid hantering av rivningsvirke. LCA:n i studien utförs enligt svenska institutets standarder och omfattar fyra faser: mål och omfattning, inventeringsanalys, miljöpåverkananalys och tolkning.  Efter kartläggningen av träavfallets resa från grind till grav konstaterades att allt träavfall från byggarbetsplatser i Karlstad går via ett antal aktörer för att slutligen förbrännas i Kvarnsveden och generera fjärrvärme. Systemets miljöpåverkan beräknades i programvaran SimaPro vilket resulterade i en fossil klimatpåverkan på 111 kg CO2 e, försurning på 0.499 mol + H e och övergödning på 0.00753 kg P e. Transporter visade sig spela en betydande roll i samtliga miljöpåverkanskategorier. Två känslighetsanalyser utfördes i syfte att undersöka alternativa scenarier för träavfallet. Det som visade sig vara mest effektivt för att sänka miljöpåverkan för systemet var att låta förbränning av träavfallet ske på Karlstads Energis värmeanläggning i Heden vilket gav en förbättring på 83% i klimatpåverkan, 39% för försurning samt 86% för övergödning. Anledningen till minskningen berodde på den förkortade transportsträckan. / The Swedish construction industry plays a significant role in the country's carbon dioxide emissions and waste production. In 2016, it accounted for nearly one-fifth of the total greenhouse gas emissions and generated up to 9.8 million tons of waste. To reduce the climate impact of new construction, the construction industry has adopted a plan that includes reduced material usage and the selection of more sustainable materials. In January 2022, a new law came into effect requiring climate declarations for buildings. The purpose of the law is to reduce the climate impact of new constructions and projects with building permits by increasing the awareness of the builder. The new law only requires a life cycle analysis from cradle to grind. In this study, a Life Cycle Assessment, LCA, is conducted to examine the climate impact, acidification, and eutrophication per ton of demolition timber from dismantling to final disposal, from gate to grave. It also investigates where in the gate to grave chain the three enviromental impact categories are most significant and what opportunities exist to reduce the enviromental impact in the handling of demolition timber. The LCA methodology in the study follows the standards of the Swedish Institute and includes four phases: goal and scope, inventory analysis, impact assessment, and interpretation. After mapping the journey of wood waste from gate to grave, it was found that all wood waste from construction sites in Karlstad goes through a number of actors to Kvarnsveden where it is incinerated and generate district heating. The environmental impact of the system was calculated in the software SimaPro, resulting in a fossil climate impact of 111 kg CO2 eq, acidification of 0.499 mol + H eq, and eutrophication of 0.00753 kg P eq. Transport was found to play a significant role in all environmental impact categories. Two sensitivity analyses were performed to explore alternative scenarios for wood waste. The most effective measure to reduce the environmental impact of the system turned out to be allowing the incineration of wood waste to take place at Karlstad Energy's heating plant in Heden, resulting in an 83% improvement in climate impact, 39% reduction in acidification, and 86% decrease in eutrophication. The reduction was attributed to the shortened transportation distance.

Con el fin de relacionar la estructura y la actividad de series de compuestos, es importante usar descriptores moleculares relevantes. Los descriptores GRIND y VolSurf pertenecen a una nueva familia de descriptores llamado libre de alineamiento. Es decir, que no necesitan alinear los compuestos con el fin de comparar sus campos de interacciones molecular. En este estudio se ha aplicado esos descriptores para la selección de reactivos químicos a partir de una amplia base de datos. La selección se ha echo mediante un protocolo que permite maximizar la diversidad de la muestra y así obtener unos compuestos muy informativos. También se ha desarrollado nuevos descriptores de forma que están basado en los cambios de curvatura de la superficie molecular. Los resultados obtenidos indican que los nuevos descriptores de forma se integran muy bien en los descriptores GRIND originales y que permiten identificar los efectos de forma tanto favorable como desfavorable. Además, se ha desarrollado nuevos descriptores libre de alineamiento llamado 'anchor-GRIND' que usan un átomo de cada molécula como punto de referencia para la comparación de los campos de interacciones molecular. Los descriptores 'anchor-GRIND' permiten una descripción mas precisa y mas sencilla que los descriptores GRIND lo que los hace mas relevante para el análisis de ciertas familias de compuestos. / In order to correlate the differences of structure with the differences of activity of series of compounds, it is important to use relevant molecular descriptors. The GRIND and VolSurf descriptors belong to the so-called alignment-free descriptors family. In other words, they do not require to align the compounds in order to compare its molecular interaction fields. In this study, we applied these descriptors to the selection of chemical reagent from a database of compounds. The selection has been done following a protocol which allows to maximize the diversity of the sample and so to obtain some compounds highly informative. In addition we developed new shape descriptors which are based on the changes of curvature of the molecular surface. The results obtained show that the new shape descriptors are well integrated in the original GRIND descriptors. Furthermore, we designed new alignment-free descriptors called 'anchor-GRIND' which use one atom of each molecule as a reference point for the comparison of the molecular interaction fields. The 'anchor-GRIND' descriptors allow a more precise and more simple description than the GRIND descriptors, which makes them more relevant for the analysis of some families of compounds.

Superligas à base de níquel têm uma grande variedade de aplicações, por exemplo, turbinas a gás de aviões, câmaras de combustão, válvulas de motores, etc. As suas principais propriedades são alta resistência mecânica às temperaturas elevadas (> 500 graus Celsius), alta resistência à abrasão, alta resistência à fadiga e boa resistência à corrosão. Por isso, são considerados materiais difíceis de serem retificados (ou Difficult To Grind - DTG). Condições severas de retificação em superligas podem causar altas temperaturas de corte (podendo atingir 1000 graus Celsius) e altas tensões (pressão) na região de contato (podendo chegar a 3450 MPa), o que leva ao desenvolvimento rápido do desgaste do rebolo, dependendo das suas características e da severidade das condições de corte. A melhoria do processo de retificação pode ser atingida com a utilização de grãos superabrasivos mais duros, como o CBN. O CBN apresenta um alto desempenho na usinagem e sua aplicação tem como principais vantagens: a redução dos tempos de ciclo, melhor qualidade e aumento de produtividade. O desgaste da ferramenta de corte nos diversos processos de fabricação é de extrema importância no custo total da produção, portanto, na retificação de superligas, o desgaste do rebolo CBN deve ser mínimo devido ao seu alto custo. O presente trabalho avalia o desempenho de um rebolo de CBN vitrificado na retificação dos materiais Inconel 751, Silcrome 1 e 21-2N. Testes foram realizados variando-se apenas a velocidade de avanço para determinar a influência deste no desgaste do rebolo. Foi possível determinar assim, a relação entre o desgaste da ferramenta e a força tangencial em um grão, obtendo-se uma curva característica do rebolo. / Nickel-based superalloys have a great variety of applications, for example, aircraft gas turbines, combustion chambers, engines valves, etc. Their main properties are high strength at high temperatures (> 500 Celsius degrees), high resistance to the abrasion, high fatigue strength and good resistance to the corrosion. Therefore, they are considered difficult to grind (DTG) materials. Severe grinding conditions of superalloys can cause high cutting temperatures (able to reach 1000 Celsius degrees) and high tensions in the contact zone (able to reach 3450 MPa). This leads to the fast development of the wear of CBN wheels, depending on the tool characteristics and the severity of the cutting conditions. The improvement of the grinding process can be reached with the use of harder superabrasive grains, as the CBN. The CBN presents high performance in machining. The main advantages are: the reduction of the cycles times, better quality and increase of productivity. The wheel wear is extreme important in the total production cost, therefore, in the grinding of superalloys, the wear CBN wheels have to be minimum due to its high cost. The present work evaluates the performance of vitrified CBN wheels in the grinding process of Inconel 751, Silcrome 1 and 21-2N. Tests were carried out varying the feed-rate to establish its influence on the wheel wear. It was possible to determine the relation between tool wear and tangential force per grain, obtaining the wheel characteristic curve.

Superligas à base de níquel têm uma grande variedade de aplicações, por exemplo, turbinas a gás de aviões, câmaras de combustão, válvulas de motores, etc. As suas principais propriedades são alta resistência mecânica às temperaturas elevadas (> 500 graus Celsius), alta resistência à abrasão, alta resistência à fadiga e boa resistência à corrosão. Por isso, são considerados materiais difíceis de serem retificados (ou Difficult To Grind - DTG). Condições severas de retificação em superligas podem causar altas temperaturas de corte (podendo atingir 1000 graus Celsius) e altas tensões (pressão) na região de contato (podendo chegar a 3450 MPa), o que leva ao desenvolvimento rápido do desgaste do rebolo, dependendo das suas características e da severidade das condições de corte. A melhoria do processo de retificação pode ser atingida com a utilização de grãos superabrasivos mais duros, como o CBN. O CBN apresenta um alto desempenho na usinagem e sua aplicação tem como principais vantagens: a redução dos tempos de ciclo, melhor qualidade e aumento de produtividade. O desgaste da ferramenta de corte nos diversos processos de fabricação é de extrema importância no custo total da produção, portanto, na retificação de superligas, o desgaste do rebolo CBN deve ser mínimo devido ao seu alto custo. O presente trabalho avalia o desempenho de um rebolo de CBN vitrificado na retificação dos materiais Inconel 751, Silcrome 1 e 21-2N. Testes foram realizados variando-se apenas a velocidade de avanço para determinar a influência deste no desgaste do rebolo. Foi possível determinar assim, a relação entre o desgaste da ferramenta e a força tangencial em um grão, obtendo-se uma curva característica do rebolo. / Nickel-based superalloys have a great variety of applications, for example, aircraft gas turbines, combustion chambers, engines valves, etc. Their main properties are high strength at high temperatures (> 500 Celsius degrees), high resistance to the abrasion, high fatigue strength and good resistance to the corrosion. Therefore, they are considered difficult to grind (DTG) materials. Severe grinding conditions of superalloys can cause high cutting temperatures (able to reach 1000 Celsius degrees) and high tensions in the contact zone (able to reach 3450 MPa). This leads to the fast development of the wear of CBN wheels, depending on the tool characteristics and the severity of the cutting conditions. The improvement of the grinding process can be reached with the use of harder superabrasive grains, as the CBN. The CBN presents high performance in machining. The main advantages are: the reduction of the cycles times, better quality and increase of productivity. The wheel wear is extreme important in the total production cost, therefore, in the grinding of superalloys, the wear CBN wheels have to be minimum due to its high cost. The present work evaluates the performance of vitrified CBN wheels in the grinding process of Inconel 751, Silcrome 1 and 21-2N. Tests were carried out varying the feed-rate to establish its influence on the wheel wear. It was possible to determine the relation between tool wear and tangential force per grain, obtaining the wheel characteristic curve.

Frequently in MMORPGs, players will encounter something known to players as farming or grinding. Grinding is a controversial matter in the gaming community, as many do not enjoy it and see it as a sign of lazy and poor game design. However, it is a difficult topic to argue as whatever is a grind, differs for each person. To elevate the discussion about grinds in the gaming community, this paper aims to give a definition of grinds and answer how they are perceived by players and designers alike. Grinds are argued to be dull, tedious and monotonous, but they are ever prevalent in games today.  To find what differentiates between a satisfying or waste of time grinding, this paper also aims to discover what makes a grind enjoyable, and when they are appropriate.  The results of this paper are built upon previous works and media on game design and grinds. Interviews were held with players that grind to get a deeper understanding of what drives players to grind. The results define grinds as the act of doing something repeatedly for one's own gain. Seven sub-grinds that are found in different games were defined, each with varying characteristics. Grinds are not inherently bad, despite the negative connotations. They are like any other aspect of a game, they can be executed well or poorly. The developers' responsibility is to design a well-balanced grind that does not hinder players from doing what they like and deliver a satisfying experience.

Introduktion: Potatisfibern utgör ca 1 % av potatisens vikt och är en restprodukt vid tillverkningen av potatisstärkelse. Idag tillsätter flera välkända livsmedelsföretag potatisfiber i sina produkter. Den främsta anledningen till detta är för att fibern kan binda vätska 7–12 gånger sin egen vikt vilket kan ge en ekonomisk fördel. Syfte: Syftet med studien är att jämföra hur grovmalen respektive finmalen potatisfiber påverkar utvalda egenskaper i degen och brödet med särskilt fokus på brödets lagringsstabilitet. Metod: Pilottester Observationer av degegenskaper Mätning av vätskeförlust och brödvolym Instrumentell färgmätning med en kolorimeter Sensorisk bedömning av lagringsstabilitet   Resultat: Pilottester av båda malningsgraderna av potatisfibern visade att vid en jämförelse av olika förbehandlingar så som skållning, blötläggning och tillsats direkt i degen, gav direkt tillsats av potatisfiber i degen flest fördelar, främst gällande mjukheten i degen. Vid observationen fanns en synlig färgskillnad mellan bröden med tillsatts potatisfiber och referensbrödet men detta säkerställdes inte vid den instrumentella färgmätningen. Brödens volym och vattenhållande förmåga påverkades inte av tillsats av potatisfiber. Den sensoriska bedömningen visade en upplevd torrhetskänsla för bröd med tillsatt potatisfiber (båda malningsgraderna) när det testades mot ett referensbröd. Den finmalda fibern påverkade lagringsstabiliteten mer än den grovmalda fibern gjorde.   Slutsats: Malningsgraden gav inga märkbara skillnader på de utvalda deg- och brödegenskaperna. Potatisfiber hade inte tillräckligt stor påverkan på deg eller bröd för att antas vara lönsam att tillsätta vid brödbakning. / Introduction: The potato fiber constitutes about 1 % of the weight of the potato and is a residual product in the manufacture of potato starch. Today, several well-known companies add potato fiber to their products. The main reason for this is because the fiber can bind liquid 7–12 times its own weight, which gives an economic advantage. Aim: The aim of this study is to investigate how the grind of potato fiber affects selected characteristics in dough and bread, with particularly focus on the storage stability of the bread. Method: Pilot tests Observations of dough characteristics Measure of water exchange and bread volume Instrumental color measurement with a colorimeter Sensory evaluation of storage stability   Results: Pilot tests with both grinds of potato fiber showed that when comparing pre-treatments such as scalding, soaking and direct addition into the dough, a direct addition resulted with the most advantages, mainly regarding the softness of the dough. During the observations there was a visible difference in color between the potato fiber loaves and the reference loaf, which was not ensured in the instrumental color measurement. The volume and water retention in the bread was not affected by an addition of potato fiber. The sensory evaluation showed a perceived dryness for bread with added potato fiber (both grinds), when tested against a reference bread. The finely ground fiber affected the storage stability more than the coarse grounded fiber did. Conclusion: The grind gave no notable differences on the selected properties of dough and bread. The impact that grind had on dough characteristics and the finished bread were small.

Το αντικείμενο της παρούσας διατριβής είναι η ανάπτυξη μεθοδολογίας προσδιορισμού της κατανομής της σκληρότητας και του βάθους διείσδυσης της σκλήρυνσης που προκαλείται σε ένα εξάρτημα το οποίο έχει υποστεί Σκλήρυνση μέσω Λείανσης (Grind-Hardening). Η διεργασία Σκλήρυνσης μέσω Λείανσης είναι μία νέα επιφανειακή θερμική κατεργασία η οποία χρησιμοποιεί την θερμότητα που αναπτύσσεται στην ζώνη λείανσης για την θερμική κατεργασία του κομματιού. Η παρούσα διατριβή επικεντρώνεται στην ανάπτυξη μαθηματικών μοντέλων ικανών να προβλέψουν τα διάφορα χαρακτηριστικά της διεργασίας (δηλ. τη τοπογραφία της επιφάνειας του λειαντικού τροχού, τις δυνάμεις κατεργασίας, την παραγωγή και τον επιμερισμό της θερμότητας και την θερμοκρασιακή κατανομή). Τα μοντέλα αυτά συνδυαζόμενα επιτρέπουν τον προσδιορισμό της κατανομής σκληρότητας και του βάθος δι-είσδυσης της σκλήρυνσης συναρτήσει των παραμέτρων της διεργασίας και των χαρακτηριστικών του λειαντικού τροχού που χρησιμοποιείται. Παράλληλα, η εφαρμογή των μοντέλων αυτών οδηγεί σε χρήσιμα συμπεράσματα σχετικά με τα όρια εφαρμογής της διεργασίας. Μετά την επιβεβαίωση των θεωρητικών προβλέψεων, εξάχθηκε βάση δεδομένων υπολογισμού του βάθους διείσδυσης της σκλήρυνσης συναρτήσει της ροής θερμότητας στο κομμάτι και των παραμέτρων της διεργασίας. Η μεθοδολογία που αναπτύχθηκε εφαρμόστηκε για την περίπτωση σκλήρυνσης οδηγών κύλισης (raceway). Το σημαντικότερο συμπέρασμα που προκύπτει από την συγκεκριμένη διατριβή είναι ότι η διεργασία σκλήρυνσης μέσω λείανσης μπορεί να θεωρηθεί αρκετά «ώριμη» ούτως ώστε να μπορεί να εισαχθεί στην βιομηχανική πρακτική για την επιφανειακή σκλήρυνση εξαρτημάτων. Τα διάφορα χαρακτηριστικά της διεργασίας μπορούν να προβλεφθούν ενώ τέθηκαν οι βάσεις δημιουργίας ενός συστήματος παρακολούθησης και προγραμματισμού της διεργασίας. / The objective of the present study is the development of a methodology capable of predicting the hardness distribution and the hardness penetration within a grind-hardened workpiece. Grind-hardening is a novel-alternative surface hardening process that utilizes the heat generated in the grinding zone for the heat treatment of the workpiece material. The present work has employed analytical and numerical modeling techniques for describing the characteristics and output of the process, i.e. the topography of the grinding wheel, the process induced forces, the heat generation and partition and the temperature distribution within the work-piece. These models when coupled allow the estimation of the hardness distribution and the hardness penetration depth as a function of the process parameters and the characteristics of the grinding wheel. Additionally, through the process modeling, the process limitations are identified. After proving the validity of the theoretical predictions, the coupled models were utilized for the extraction of a data base providing the hardness penetration depth as a function of the heat flow entering the workpiece and the process parameters. The developed methodology was used for programming the grind-hardening of raceways. The main conclusion of this work is that grind-hardening process can be nowadays introduced in the industrial practice. The methodology developed, allows the prediction of the process outcome and can be used in the future for setting up an on-line monitoring system and / or develop an off-line process programming system.

Livscykelanalys (LCA) används för att beräkna produktsystemets potentiella miljöpåverkan och identifiera hotspots i livscykeln. Resultatet kan användas för att tilllämpaåtgärder på produktsystemets hotspots för en minskad potentiell miljöpåverkan. SCC AB är specialiserade på tillverkning av härvsatser, som är en delkomponent ielmotorer och generatorer. En härvsats består av lindningstråd gjord av koppar ochisoleringsmaterial. Syftet med denna studie är att redovisa kvalitativa- och kvantitativadata om härvsatsens potentiella miljöpåverkan under tillverkningen genom att– beräkna potentiell miljöpåverkan från vald härvsats– identifiera var det finns störst potential att göra förbättringar i livscykel– redovisa förbättringar för att minska potentiell miljöpåverkan i livscykeln. Den funktionella enheten (FE) är definierad som nytillverkning av generatorlindning tillrenovering av elektrisk utrustning. I jämförelse med andra härvsatser är den av mellanstorlek ochinte den mest producerade härvtypen på SCC. Den har en märkspänning (Un) på 13,8 kV ochbestår av 100 härvor gjorda av 1650 kg koppar och 230 kg isoleringsmaterial. Resultatet erhålls för miljöpåverkanskategorierna Global uppvärmnings-potential(GUP), försurnings-potential (FP) och abiotisk resursutarmnings-potential (ARP). Global uppvärmning beror främst på smältverket och koppargruvan som står för 43%respektive 38% av det totala bidraget på 9106 kg koldioxidekvivalenter (CO2e). Detär främst smältverket som bidrar till försurning på 63% av det totala bidraget på 279kg svaveldioxidekvivalenter (SO2e). Abiotisk resursutarmning beror till största delenpå koppargruvan som står för 82% av det totala bidraget på 3330 kg kopparekvivalenter (CUe). Förbättringsanalysen är baserad på ett materialflödesbaserat cirkularitetsmått (MEM),vilket beräknas genom att jämföra användning av primär- och sekundär kopparråvarai produktionen. Analysen visar att det finns sekundärproducerad lindningstråd påmarknaden som kan användas i tillverkning och kan beställas till en extra kostnad. Slutsatsen är att sekundärproducerad lindningstråd kan ersätta primärproduceradlindningstråd till en extra ekonomisk kostnad för att tillämpa en open loop mellan SCCAB och smältverket. Det kan bidra till en potentiellt minskad miljöpåverkan och enfrämjad CE. / Lifecycle assessment (LCA) is used to calculate the products potential environmentalimpact and identify hotspots in the life cycle. The result can be used to apply measuresto the product system hotspots for a reduced potential environmental impact. SCC AB specializes in the manufacture of coils, which are a sub-component in electricmotors and generators. A coil set consists of winding wire made of copper and insulating material. The purpose of this study is to present qualitative and quantitativedata on the coil set during production by– calculate the potential environmental impact from the selected coil set– identify the greatest potential to make improvements in the life cycle– report improvements to reduce the potential environmental impact in thelife cycle. The functional unit (FU) is defined as the manufacture of generator coil set for the renovation of electrical equipment. In comparison with other coil set, it is of medium size and not themost produced coil set on SCC. It has a rated voltage (Un) of 13.8 kV and consists of 100 coilsmade of 1650 kg of copper and 230 kg of insulation material. The result is obtained for the environmental impact categories global warming potential (GWP), acidification potential (AP) and abiotic resource depletion potential(ADP). Global warming is mainly due to the copper smelter and the copper mine,which account for 43% and 38%, respectively, of the total contribution of 9106 kgcarbon dioxide equivalents (CO2e). It is mainly the copper smelter that contributesto acidification of 63% of the total contribution of 279 kg sulphur dioxide equivalents(SO2e). Abiotic resource depletion is largely due to the copper mine, which accountsfor 82% of the total contribution of 3330 kg of copper equivalents (CUe). The improvement analysis is based on a material flow circularity measure (MEM),which is calculated by comparing the use of primary and secondary copper materialin the production. The analysis shows that there are secondary-produced wires on themarket thar can be used to produce the coil set. The conclusion is that secondary produced winding wire can replace primary windingwire at an extra financial cost to apply an open loop between SCC AB and the smelter.It can contribute to a potentially reduced environmental impact and a promoted CE.

Regeringen har en vision att till 2050 ska Sverige uppnå en fordonsflotta som är fossilfri och för att uppnå den visionen ska el som drivmedel spela en avgörande roll på marknaden. HEM Nät AB är därmed intresserade av hur deras lokalnät i ett valt område kan påverkas när en större andel av hushållen införskaffar elbilar. Längs områdets högspänningsslinga finns nio nätstationer som matar ut effekt till 815 kunder. En känslighetsanalys genomfördes kring det valda lokalnätet med avseende till dess kapacitet idag till framtida belastningar från elbilar. Analysen baserades på fyra olika nätparametrar som möjligen kan riskeras med avseende till elbilars laddsystem: spänningsfall, transformatorbelastning, övertoner och osymmetri. Olika laddeffekter och kopplingssätt har även jämförts bland nätparametrarna för att visa vilken roll de kan ha i framtiden. Spänningsfallet samt transformatorbelastning för de båda effekterna 3,7 kW och 11 kW uppgick mot de satta nätkraven när 40 % respektive 20 % belastning sker i området. Två vetenskapliga metoder användes för att uppskatta övertonerna där ena tog hänsyn till en reduktion av sammanlagrade övertoner och den andra metoden använde en aritmetisk summering av strömövertonerna. Resultatet visade att med varken en inkluderad reduktion eller med den aritmetiska summeringen kommer övertonerna bli ett problem. Med simuleringen av osymmetri nåddes nätkravet när 7 % mer belastning skedde under en och samma fas. Slutligen kom studien fram till att lokalnätet är relativt starkt och kan klara av 322 elbilar vid 3,7 kW och 161 elbilar vid 11 kW. / The Swedish government have a vision that up untill 2050 Sweden’s transport system is going to be free of fossil fuels and to achieve this vision, electricity is going to be the main fuel and will play a decisive role in the future transportional market. As a result of this, HEM Nät AB is now interested in knowing how their local electrical grid will be affected by a larger amount of electric vehicles, EVs, charged through households. Along the local grid’s high voltage line there are nine substations, which provide power to 815 customers. A sensitivity analysis was conducted on the local grid to appreciate the available capacity for the future load of EVs. The analysis was based on four different gridparameters, which possibly can affect the set conditions of an electrical grid when an EV is being charged: voltage drop, transformer load, harmonics and dissymmetry. Different chargepowers and wirings have also been compared to see what roles they will have in the future. After the simulations and hand calculations all of the gridparameters exceeded the set conditions. This happened at different percentages of the households, which were charging their vehicles. The voltage drop and transformer load for both of the powers, 3,7 kW and 11 kW exceeded the limitations when 40 % respectively 20 % of the studied are was being loaded. Two scientific methods were used to appreciate the added current harmonics, where the first one regarded a reduction of the summarized value of the current harmonics, where the second did not. The results showed, that either of the methods would indicate a problem on the grid. The simulation of the dissymmetry, the limitation was met after 7 % more load was done under one and the same of the phases. Finally, the study concluded that the local grid is relatively strong and can hold 332 EVs with 3,7 kW and 161 EVs with 11 kW.

Superligas são materiais utilizados nas indústrias aeronáuticas, nucleares, metal-mecânicas, petroquímicas, automotivas e biomédicas, sendo considerados de difícil retificação (Difficult To Grind - DTG), devido às suas características peculiares. Para a retificação eficiente destes materiais, frequentemente utiliza-se rebolos superabrasivos com grãos de cBN (cubic boron nitride) e ligante vitrificado, devido a seu desempenho superior, quando comparado aos rebolos convencionais. Entretanto, é necessária a utilização de periféricos e sistemas auxiliares eficientes, elevando-se, assim, os custos. Visando a redução dos custos operacionais, os rebolos convencionais com grãos cerâmicos e ligantes com alta capacidade de retenção surgem como uma alternativa promissora. Neste cenário de comparação ferramental, torna-se necessário mensurar o desempenho das mesmas, que incluem requisitos técnicos e indicadores de sustentabilidade do processo. Assim, o objetivo desta dissertação é avaliar um rebolo convencional modificado tecnologicamente (grão cerâmico e ligante de alto desempenho), comparando-o com um rebolo de cBN vitrificado, buscando-se mensurar as diferenças de desempenho e critérios de sustentabilidade (econômicos, ambientais e sociais) do processo, quando da retificação de superligas, com diferentes graus de usinabilidade. A metodologia de análise comparativa do desempenho dos rebolos deu-se pela avaliação da influência de parâmetros de entrada (velocidade de corte, material e taxa específica de remoção utilizada) nas variáveis de saída, a serem monitoradas, relativas ao processo (potência; energia específica; desgaste - relação G e força tangencial por grão-; superfície do rebolo; e cavacos), à qualidade final da peça (rugosidade, circularidade e análise superficial - topografia, microestrutura e microdureza) e custos associados ao processo, além dos indicadores de sustentabilidade. Como resultados, em relação ao impacto da velocidade de corte, demonstrou-se que seu aumento é benéfico ao processo, devido à diminuição da espessura de corte e menores forças por grão, acarretando em menores desgastes do rebolo (maior relação G) e melhor qualidade superficial da peça retificada. Tal resultado é inversamente proporcional à taxa de remoção. No tocante aos materiais, comprovou-se que as superligas analisadas possuem diferentes capacidades de retificação, devido às diferentes microestruturas e propriedades químico-mecânicas, que impactam no desempenho da ferramenta abrasiva. O material Inc.751 apresentou a pior capacidade de retificação dentre os materiais analisados, devido, principalmente, à sua matriz austenítica e presença de Alumínio e Titânio na composição química. Pela análise dos cavacos, comprovou-se que os mesmos possuem formatos alongados, típico de materiais dúcteis e ratificou-se a eficiência da refrigeração na região de contato rebolo/peça. Com a curva característica dos rebolos, verificou-se que as ferramentas possuem comportamentos distintos, com superioridade ao rebolo de cBN, devido à maior capacidade de retenção dos grãos pelo ligante. Pela verificação superficial dos rebolos, não se observou empastamento evidente, constatando a eficiência do sistema de limpeza de alta pressão. Pela análise topográfica das peças, verificou-se que a retificação não induziu danos térmicos às mesmas. A avaliação dos indicadores de sustentabilidade proporcionou uma melhor análise da eficiência do processo, facilitando na tomada de decisão quanto ao desempenho do rebolo e/ou condição ideal. Como conclusão, a aplicabilidade do rebolo convencional em substituição ao rebolo de cBN foi confirmada para a retificação das superligas testadas. / Superalloys are materials used in aeronautical, nuclear, metal-mechanical, petrochemical, automotive, and biomedical industries, and they are considered Difficult To Grind (DTG) due to their peculiar characteristics. For efficient grinding of these materials, superabrasive grinding wheels with cBN (cubic boron nitride) grains and vitrified bond are often used because of their superior performance when compared to conventional grinding wheels. However, it is necessary to use efficient peripheral and auxiliary systems, thus raising costs. Aiming to reduce costs, conventional wheels with ceramic grains and binders with high retention capacity appear as a promising alternative. In this tool comparison scenario, it is necessary to measure their performance, which includes technical requirements and process sustainability indicators. Thus, the objective is to evaluate a engineered conventional grinding wheel, comparing it with a vitrified cBN wheel, aiming to measure performance differences and sustainability criteria (economic, environmental, and social) of the process, when grinding superalloys with different degrees of grindability. The methodology of comparative analysis of the performance of the grinding wheels was based on the evaluation of the influence of input parameters (cutting speed, material, and specific removal rate) in the output variables to be monitored related to the process (power, specific energy, roughness - ratio G and tangential force per grain, Ft1g, grinding wheel surface, and chips), to the final quality of the piece (roughness, roundness, and surface analysis - topography, microstructure, and microhardness) and costs, in addition to the sustainability indicators. As results, in relation to the impact of the cutting speed, it was demonstrated that its increase is beneficial to the process, due to the reduction of the cutting thickness and lower Ft1g, causing less wheel wear and better surface quality of the ground piece. This result is inversely proportional to the removal rate. Regarding the materials, it was verified that the analyzed superalloys have different grinding capacities due to the different microstructures and chemical-mechanical properties that impact the performance of the abrasive tool. The material Inc.751 presented the worst grinding capacity among the analyzed materials, mainly due to its austenitic matrix and the presence of Aluminum-Titanium in its composition. By the analysis of the chips, it was verified that they have elongated formats, typical of ductile materials, and it was ratified the efficiency of the cooling system. With the wheel characteristic curves, it was verified that the tools have different behaviors, superior to the cBN wheel, due to the greater capacity of retention of the grains by the binder. Through the investigation of the grinding wheels, no evident wheel loading was observed, noting the efficiency of the high-pressure cleaning system. By the analysis of the pieces, it was verified that the grinding did not induce thermal damages to them. The evaluation of the sustainability indicators provided a better analysis of the efficiency of the process, making easier the decision-making on the performance of the grinding wheel and/or ideal condition. Concluding, the feasibility of the conventional wheel in substitution of the cBN wheel was confirmed for the grinding of the tested superalloys.