An Investigation of Mixed Cellulose Esters and Acyclic Polyacetates: Effects of Side-Chain Lengths and Degrees of Ring-Opening

Bio-based polymers produced from natural sources are gaining an increased interest as potential replacement for today’s conventional fossil-based plastic polymers. Their use is already wide in many large-scale industrial areas such as healthcare, personal care, and food.To widen the potential of biopolymers in new applications such as plastics, their properties need to be tuned by modification to handle factors like relative humidity, which is especially important for gas barriers in food packaging. This thesis explores the effect of two structural variations of cellulose esters, one where the average side-chain length is increased, going fromcellulose acetate to cellulose acetate propionate and then cellulose acetate butyrate, and another where the polymer backbone of cellulose acetate is ring-opened. These two modifications affect the glass transition temperature, an important structural factor. The effect of the average side-chain length is explored to a greater extent where they are studied for impact on mechanical properties, water content, water sorption at different RH, the kinetics of water sorption at different RH, mechanical properties at different RH and oxygen permeation at different RH. The focus is on how water interacts with the different esters with regard to the average side-chain length and how water affects their properties. An increase of average sidechain length and the ring-opening were shown to decrease the glass transition temperature.Together with the water sorption and Hansen solubility parameter, it was concluded that longer average side-chain length screens out hydrogen bonding between the polymers. The studies on the average side-chain length and water sorption indicated that water entering the cellulose acetate creates clusters. These formed water clusters create cavities in the polymer which makes the polymer hold more water than before introducing of the water clusters. Oxygen permeation studies on prewetted films prove that these cavities created by water clustering are still present after drying the material at 0% RH and thus resulted in a higher oxygen permeation compared to films that had not been exposed to higher than 50% RH

Interactions Between Water and Cellulose Esters

Biopolymers, which are produced from natural sources, are gaining interest as a potential replacement for fossil-based polymers. As such, they are already widely used in several industries, including the food, healthcare, and personal care industries. To harness the full potential of biopolymers as materials in new products designed for specific tasks, an ability to accurately predict their properties and how these properties change in different environments, is desirable. Hansen Solubility Parameters (HSP) combine dispersive, polar, and hydrogen bonding energies to understand interactions between molecules. This thesis explores the potential use of HSP as predictors of glass transition temperatures (Tg) and water interactions. It also focuses on elucidating the effect of an increased side-chain length of cellulose esters on their thermal properties, structural properties, and water interactions, together with how these properties are affected by the absorption of water. The cellulose esters studied here were cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate.The HSP showed that the dispersive energy dominates the total cohesive energy, followed by the hydrogen bonding and then the polar energy. Counter-intuitively, the Tg decreased with an increased total cohesive energy. The HSP explained this phenomenon, namely, that the increased length of the substituents screened the short-range hydrogen bonds. A similar effect was observed for water solubility and penetration into the cellulose esters, which decreased with increasing side-chain lengths despite the approximately constant hydrogen bonding energies. This indicates the importance of focusing on each of the different interaction parameters instead of only the total HSP

RANCANG BANGUN MULTIMEDIA PEMBELAJARAN BERBASIS GAME ADVENTURE MENGGUNAKAN METODE PROBLEM SOLVING UNTUK MENINGKATKAN PEMAHAMAN SISWA PADA MATERI JARINGAN KOMPUTER

Penelitian ini bertujuan untuk merancang-bangun multimedia pembelajaran berbasis game adventure menggunakan metode problem solving pada materi jaringan komputer, mengetahui peningkatan hasil belajar siswa terhadap mata pelajaran jaringan dasar yang dalam pelaksanaannya menerapkan multimedia pembelajaran berbasis game adventure menggunakan metode problem solving, dan mengetahui signifikan besarnya peningkatan hasil belajar siswa setelah menerapkan multimedia pembelajaran berbasis game adventure. Tahapan pengembangan multimedia pembelajaran ini terdiri dari tahap analisis, desain, pengembangan, implementasi, dan tahap penilaian. Multimedia pembelajaran yang telah dikembangkan kemudian diimplementasikan di SMK BPI Bandung dan data yang diolah diperoleh dari tes yang dilakukan oleh siswa setelah menggunakan multimedia pembelajaran. Sementara untuk data penilaian terhadap multimedia menggunakan kuesioner yang dirancang berdasarkan Learning Object Review Instrument (LORI) version 1.5 yang ditujukan kepada ahli materi dan ahli media, juga siswa sebagai pengguna aplikasi multimedia tersebut. Dari penelitian ini didapatkan bahwa (1) penilaian multimedia oleh ahli media terhadap multimedia pembelajaran berbasis game adventure menggunakan metode problem solving sebesar 89,57%, termasuk ke dalam kategori sangat baik, penilaian multimedia oleh ahli materi sebesar 85%, termasuk ke dalam kategori sangat baik, dan penilaian pengguna terhadap multimedia sebesar 97,69% termasuk ke dalam kategori sangat baik; (2) multimedia dapat meningkatkan hasil belajar siswa dilihat dari adanya peningkatan signifikan nilai dengan hasil th (8,81) > tt (2,42), gain sebesar 0,61 yang termasuk kedalam kategori sedang, dan tanggapan siswa terhadap multimedia sebesar 97,74% termasuk ke dalam kategori sangat baik.;--- This research aims to design Multimedia Learning adventure game based uses a problem solving method for materials computer networking, to know improving student learning outcomes of the course base networking that is in the implementation implement multimedia learning adventure game based uses a problem solving method. Moreover, it is to know how significant size the improving of student learning outcomes after applying the multimedia learning adventure game based. Multimedia development stages of this learning phase consists of the analysis, design, development, implementation and assessment phase. Multimedia learning that has been developed and then implemented in SMK BPI Bandung and the processed data obtained from tests performed by the students after using multimedia learning. As for the assessment data of multimedia used the questionnaire that was designed based on the Learning Object Review Instrument (LORI) version 1.5, which is addressed to subject matter experts and media experts, as well as the students as the multimedia application users. From this study, it was found that (1) the assessment of multimedia by media experts to multimedia learning adventure game based uses a problem solving method at 89.57%, included into the excellent category, multimedia votes by subject matter experts of 85%, including into the excellent category, and assessment of users to multimedia by 97,69% included into excellent category; (2) multimedia can improve student learning significant outcomes if it had been seen from any increase in value with a th (8,81) > tt (2,42), gain of 0.61 included into medium category, and reaction of students to multimedia by 97,74% included into excellent category

Etablering av underbestånd i planterade ekskogar

Underbestånd förekommer i olika typer av naturliga ekskogar och lövblandskogar med inslag av ek. De är viktiga för den biologiska mångfalden. I produktionsskog där målet är att producera högkvalitativt ektimmer är underbeståndet också mycket viktig då det har kvalitetsdanande egenskaper. Dessvärre är underbestånden ofta dåligt utvecklade i svenska ekskogar. Ekbestånd som anlagts på före detta jordbruksmark saknar i princip fröbank och rotsystem från de olika underbeståndsarter som naturligt förekommer i ekskogar. Det krävs alltså att dessa arter koloniserar beståndet för att ett underbestånd skall etableras. Den här studien undersöker hur artrik denna kolonisation är, samt vad som begränsar olika arters spridning till de nya bestånden. 22 ekbestånd som anlagts på före detta jordbruksmark i södra Skåne inventerades på arter med vedartad stam i fält-, busk-, och trädskikt. Ekbestånden var fördelade på fem olika kategorier beroende på ålder och grad av isolering i landskapet. Artantalen i de olika beståndskategorierna analyserades statistiskt för att utröna huruvida ålder och isolering påverkade frekvensen av arter. En handfull intressanta arter analyserades vidare för att ta reda på om fröstorlek och spridningstrategi kunde förklara olika arters förmåga att kolonisera ekbestånd. Studien fann att många arter har en god spridningsförmåga och att ett stort antal arter har förmåga att sprida sig till de nya bestånden. Artrikedomen avtar dock med beståndets grad av isolering. Resultatet visar också att en viss minskning av arter sker med stigande ålder hos det anlagda ekbeståndet men också att artsammansättningen förändras i takt med att beståndet åldras. De olika arternas framgång i kolonisering och etablering kan sannolikt till stor del förklaras av arternas fröstorlek och spridningsstrategi. De arter som har lätta frön eller sprids med hjälp av avifaunan har god spridningsförmåga.The understory is vital for biodiversity in various types of natural oak- and mixed deciduous forests. In production forests where the goal is to produce high-quality oak timber the understory is equally important because it promotes quality in the timber. Unfortunately, the understory is often poorly developed in Swedish oak forests. Oak stands planted on former agricultural land do not, in principle, have a seed bank and root systems from the different woody species that naturally occur in oak forests. It is therefore required that these species colonize the stand from an adjacent potential source for a sub-population to be established. This study examines the success of this colonization and discusses what is limiting the dispersal of different species. 22 oak stands planted on former agricultural land in southern Sweden were inventoried on woody species in the field, shrub and tree layer. The oak stands were divided into five categories according to age and degree of isolation in the landscape. The total number of species in the different stand categories was analyzed statistically to investigate whether age and isolation affected the frequency of the species. A handful of interesting species were further analyzed to determine if seed size and distribution strategy could explain the different species' ability to colonize the oak stands. The study found that many species have good dispersal ability and that a large number of species have the ability to spread to new stands. Species diversity declines, however, with the stand's degree of isolation. The results also show that some reduction in the number of species occurs with advancing age of the oak stand, but also that the species composition is changing as the oak stand ages. The different species' success in the colonization and establishment can probably be largely explained by their seed size and spreading strategy. The species that have light seeds or are spread by the avifauna are most successfully established in the new stands

Organizational Hindrances to the Retention of Older Healthcare Workers

The Swedish healthcare sector is currently experiencing recruitment difficulties combined with increasing demand for healthcare services. This study accordingly seeks knowledge of the obstacles to and opportunities for retaining older employees in the Swedish healthcare sector. Results of interviews with line managers and human resource (HR) partners indicate that the informants have positive attitudes toward older healthcare workers in general, particularly acknowledging their contributions based on long experience and skill. However, line managers’ high workload, the absence of age-management strategies, and universal HR policies not conducive to older workers’ individual needs are considered obstacles to retention on an organizational level. To retain older healthcare workers and maintain their ability and motivation, the healthcare sector and especially HR strategies need to be more proactive in addressing these issues, and formalized policies are required in order to benefit from the potential labor reserve that older employees constitute

Mass Transport of Lignin in Confined Pores

A crucial step in the chemical delignification of wood is the transport of lignin fragments into free liquor; this step is believed to be the rate-limiting step. This study has investigated the diffusion of kraft lignin molecules through model cellulose membranes of various pore sizes (1-200 nm) by diffusion cells, where the lignin molecules diffuse from donor to acceptor cells through a membrane, where diffusion rate increases by pore size. UV-vis spectra of the donor solutions showed greater absorbance at higher wavelengths (similar to 450 nm), which was probably induced by scattering due to presence of large molecules/clusters, while acceptor samples passed through small pore membranes did not. The UV-vis spectra of acceptor solutions show a characteristic peak at around 350 nm, which corresponds to ionized conjugated molecules: indicating that a chemical fractionation has occurred. Size exclusion chromatography (SEC) showed a difference in the molecular weight (M-w) distribution between lignin from the donor and acceptor chambers. The results show that small pore sizes enable the diffusion of small individual molecules and hinder the transport of large lignin molecules or possible lignin clusters. This study provides more detail in understanding the mass transfer events of pulping processes

Screening of hydrogen bonds in modified cellulose acetates with alkyl chain substitutions

This study aimed to elucidate how the glass transition temperature and water interactions in cellulose esters are affected by the structures of their side chains. Cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate with three fractions of butyrates, all having the same total degree of substitution, were selected, and hot-melt pressed. The degree of substitution, structural properties, and water interactions were determined. The Hansen solubility parameters were calculated and showed that the dispersive energy dominates the total cohesive energy, followed by hydrogen bonding and polar energy. The glass transition temperature (Tg) decreased, counter-intuitively, with an increased total cohesive energy, which can be explained by the short-range hydrogen bonds being screened by the increased length of the substituents. The solubility and penetration of water in the cellulose esters decreased with increased side chain length, although the hydrogen bonding energies for all the esters were approximately constant

Problematiken kring Easyswitch och spårväxelstandarden 60E

Spårväxeln är en viktig komponent i järnvägsanläggningen som möjliggör byte mellan spår. Att växeln fungerar väl är viktigt ur trafikeringssynpunkt då den största delen av trafiken någon gång måste byta spår under sin färd mellan två destinationer. Problemen kan bli påtagliga med en icke-fungerande växel vilket orsakar försenade/inställda tåg och resenärer som kostar samhället pengar. Att införa nya komponenter i järnvägsanläggningen i Sverige är dyrt och görs inte på en dag. Tester ska utföras och en säkerhetsbevisning ska finnas. Easyswitch och 60E är och har varit omtalade i järnvägsbranschen den senaste tiden. Många negativa åsikter har framkommit efter alla problem som varit med Easyswitch och 60E i samband med dess ibruktagning och drift. Examensarbetet tar upp hur upphandling av nya komponenter och införande i anläggning går till hos Trafikverket. Mot bakgrund av denna beskrivning diskuteras införandet av 60E och Easyswitch. Arbetet behandlar också problemen som varit med Easyswitch och 60E under ibruktagning och drift samt eventuella och slutgiltiga lösningar till dessa. Information och data har inhämtats från bland annat föreskrifter och standarder från Trafikverket och även till stor del från intervjuer. Intervjuerna har gjorts för att få information från inblandade parter där information inte finns tillgänglig i skriftlig form, samt för att få aktuell information

Varumärkesrättsliga fel, kan innebära marknadsrättsliga rätt - Samspelet mellan varumärkes- och marknadsrätten – med fokus på renommésnyltning

It is not uncommon that different judicial areas can be administered at the same time. This is the case regarding trademark law and law of marketing. The main purpose with the law of marketing is to serve as an extended protection when the requirements within trademark law are not fulfilled. Since these two judicial areas run alongside each other important aspects within trademark law and law of marketing are highlighted to investigate uncertain legal questions. The trademark law is one of few fully harmonized areas of law within the European Union. The demands that need to be fulfilled for a trademark to be registered includes the earlier demand of graphical representation combined with the still relevant criteria that a sign can be distinguished from other undertakings. The so-called unconventional trademarks, which must be perceived with one of the five human senses, have had difficulties meeting the requirement of graphical representation compered to common conventional trademarks. However, the demand of graphical representation was rescinded the 1st of October 2017. The new definition in the directive allows tools such as general technology to reproduce a trademark. The effect that this change of requirement will have is uncertain, but since general technology is a more widespread definition compared to graphical representation, it may be argued for that this change will have a positive effect for the part that wishes to register an unconventional trademark. The constantly changing trademark law has resulted in that different questions have surfaced regarding how and when a trademark can be protected. The Court of Justice of the European Union has in important case law, without any motivation in particular, introduced several functions that can be protected in excess of the original function. However, the practical effect has in many aspects proven to be the same as before the functions were introduced. The holders of trademarks with a reputation are often facing the problem that less established companies are trying to free-ride on these well known companies’ trademarks. This phenomenon goes under the term passing-off which is regulated in 5 § Marknadsföringslagen, (2008:486), MFL, (the general clause). Consequently, there is no substantially section of law regarding passing-off as an infringement and the only way to deal with passing-off is through the general clause. The lack of a legal regulation of passing-off as a phenomenon has resulted in an insufficient law of marketing. Regardless if passing-off should have its own legal regulation, passing-off includes far to high prerequisites compared to other infringement within the illegal marketing. A statement that is strengthened due to the fact that passing-off can be used as sole grounds for action and must not be combined with other deceiving marketing. It is possible for business owners to succeed older business owners repute due to intense marketing, resulting in a higher value of attention for the new undertaking compared to the original trademark. Since case law indicates that such succession of repute is possible one may wonder if this should be legally acceptable. Based on all evaluated questions, the thesis ends in the same way as it began, with grounds in the similarities between trademark law and law of marketing. These similarities constitute the core when answering if the legal trial of marketing is done free-standing from the legal trial of trademark, based on the likelihood of confusion, reputation, passing-off within well known concepts and based on the application of the principle of illegality.Det är inte ovanligt att olika rättsområden kan tillämpas samtidigt och omlott. Så är fallet gällande varumärkesrätt och marknadsrätt. Marknadsrätten fungerar ofta som ett utökat skydd när varumärkesrätten inte är tillämplig. Då dessa rättsområden löper parallellt med varandra har viktiga varumärkes- och marknadsrättsliga aspekter lyfts för att utreda oklara juridiska frågor. Varumärkesrätten är ett av få fullständigt europeiserade rättsområde. Grundtanken är att varumärken accepteras för registrering så länge dessa uppnår kravet på särprägel och det tidigare kravet på grafisk återgivning. De så kallade okonventionella varumärkena, vilka kan uppfattas med våra fem sinnen, har många gånger inte uppfyllt kravet på grafisk återgivning jämfört med vanliga konventionella varumärken. Det varumärkesrättsliga registreringskravet gällande grafisk återgivning togs dock bort den 1 oktober 2017. Numera är det tillåtet att med hjälp av allmän teknik återge ett befintligt varumärke. Hur denna förändring kan komma att påverka förekomsten av okonventionella varumärken är öppet för spekulation, men då allmän teknik är ett krav med mer generell karaktär jämfört med kravet på grafisk återgivning, kan utfallet bli positivt för den som vill registrera ett okonventionellt varumärke. Den ständigt föränderliga varumärkesrätten har inneburit frågetecken gällande när och hur ett varumärke kan skyddas. EU-domstolen har i viktiga rättsfall, utan någon egentlig motivering, introducerat diverse skyddsvärda funktioner som ett utökat skydd jämte skyddet för ett varumärkes ursprung. Den praktiska effekten har i många avseenden dock visat sig innebära oförändrade skyddsmöjligheter. Innehavare av notoriska varumärken står ofta inför problemet att mindre företag försöker åka snålskjuts på väletablerade företags varumärke. Ett fenomen som går under beteckningen renommésnyltning vilket regleras i den allmänna generalklausulen, 5 § Marknadsföringslagen (2008:486), MFL. Följaktligen existerar inget uttryckligt lagrum gällande renommésnyltning. Konsekvensen av utevaron av en uttrycklig lagregel för renommésnyltning har resulterat i en otillräcklig marknadsföringslag. Oavsett om en lagreglering av renommésnyltning borde införas eller inte förekommer det rekvisit sammankopplat med renommésnyltning vilka är för högt ställda jämfört med vad som krävs för annan otillbörlig marknadsföring. I synnerhet med hänsyn till att renommésnyltning inte längre behöver sammankopplas med vilseledande marknadsföring utan numera kan förekomma som ensam grund för talan. Det är möjligt för näringsidkare att överta andra företags renommé på grund av intensiv marknadsföring, vilket i sin tur leder till att det nyare företaget erhåller ett högre uppmärksamhetsvärde än den ursprungliga näringsidkaren. Det kan följaktligen ifrågasättas om ett sådant övertagande av renommé är legitimt. Avslutningsvis, med samtliga frågeställningar besvarade avrundas uppsatsen på samma sätt som den började, med beaktande av diverse likheter rättsområdena emellan. Dessa likheter ligger i sin tur till grund för att ta ställning till om den marknadsrättsliga prövningen sker fristående från den varumärkesrättsliga med hänsyn till förväxlingsrisk, anseendeskydd, renommésnyltning vid kända koncept och till lagstridighetsprincipen