In this thesis we design and develop algorithms for predicting the rheological behavior of polymer melts based on the results of detailed atomistic simulations and guided by theories of the Dynamics of Polymers and fundamental Principles of Science of the Non-Equilibrium Thermodynamics. More specifically: 1) We propose a new rheological constitutive model for the time evolution of the tensor conformation tensor C of chains in a polymer melt (and hence the stress tensor τ) using the generalized bracket formalism of Beris and Edwards. The new constitutive model includes terms that describe a whole range of phenomena and are successfully used to describe the rheological properties of commercial polyethylene resins. 2) We developed a new methodology that allows direct connection of the results of atomistic simulations with molecular reptation theory for entangled polymers. The final result of the methodology is the calculation of the function ψ(s,t) which expresses the probability that the segment s along the contour of the primitive path remain in the original tube after time t. 3) We extended the Rouse theory for systems without polymer chain ends, as the polymer rings. While there have been previous theoretical work, a comprehensive analysis of the Rouse model of cyclic polymers was still lacking; here we develop the theory in its entirety. / Στα πλαίσια της παρούσας διατριβής σχεδιάσαμε και αναπτύξαμε αλγορίθμους πρόβλεψης της ρεολογικής συμπεριφοράς πολυμερικών τηγμάτων βασιζόμενοι στα αποτελέσματα λεπτομερών ατομιστικών προσομοιώσεων, καθοδηγούμενοι όμως από Θεωρίες της Δυναμικής των Πολυμερών αλλά και από θεμελιώδεις αρχές της Επιστήμης της Θερμοδυναμικής Εκτός Ισορροπίας. Πιο συγκεκριμένα: 1) Προτείνουμε αρχικά ένα νέο ρεολογικό καταστατικό μοντέλο για τη χρονική εξέλιξη του τανυστή διαμορφώσεων C των αλυσίδων σε ένα πολυμερικό τήγμα (και κατ’ επέκταση για τον τανυστή των τάσεων τ) κάνοντας χρήση του φορμαλισμού των γενικευμένων αγκυλών των Beris και Edwards. Το νέο καταστατικό μοντέλο περιλαμβάνει όρους που περιγράφουν ένα ολόκληρο φάσμα φαινομένων και χρησιμοποιήθηκε με επιτυχία για την περιγραφή των ρεολογικών ιδιοτήτων εμπορικών ρητινών πολυαιθυλενίου. 2) Αναπτύξαμε μια καινούργια μεθοδολογία που επιτρέπει την άμεση σύνδεση των αποτελεσμάτων των ατομιστικών προσομοιώσεων με τη μοριακή θεωρία του ερπυσμού για διαπλεγμένα πολυμερή. Το τελικό αποτέλεσμα της μεθοδολογίας είναι ο υπολογισμός της συνάρτησης ψ(s,t) που εκφράζει την πιθανότητα το σημείο s κατά μήκος του περιγράμματος του πρωτογενούς δρόμου των αλυσίδων να παραμένει στον αρχικό σωλήνα μετά από χρόνο t. Επεκτείναμε τη θεωρία Rouse και για συστήματα πολυμερικών αλυσίδων δίχως άκρα, όπως αυτά των πολυμερικών δακτυλίων. Παρότι στίγματα της θεωρίας είχαν παρουσιαστεί και σε προηγούμενες εργασίες από άλλους ερευνητές, στην παρούσα διατριβή αναπτύξαμε τη θεωρία στην ολότητά της.

Volume overload is a common feature in patients on haemodialysis (HD). This contributes significantly to the cardiovascular disease burden seen in these patients. Clinical assessments of the volume state are often inaccurate. Techniques such as interdialytic blood pressure, relative blood volume monitoring, bioimpedance are available to improve clinical effectives. However all these techniques exhibit significant shortcomings in their accuracy, reliability and applicability at the bed side. We evaluated the usefulness of a dual compartment monitoring technique using Continuous Segmental Bioimpedance Spectroscopy (CSBIS) and Relative Blood Volume (RBV) as a tool to assess hydration status and determine dry weight. We also sought to evaluate the role of Atrial Natriuretic Peptide (ANP) and B-type Natriuretic Peptide (BNP) as a volume marker in dialysis patients. The Retrospective analysis of a historical cohort (n = 376, 55 Diabetic) showed a significant reduction in post-dialysis weights in the first three months of dialysis (72.5 to 70kg, p<0.027) with a non-significant increase in weight between months 6-12. The use of anti-hypertensive agents reduced insignificantly in the first 3 months, increased marginally between months 3-6 and significantly increased over the subsequent 6 months. The residual urea clearance (KRU) fell and dialysis times increased. The cohort was very different to that dialysing at Tassin and showed a dissociation between weight reduction and BP control. This may relate to occult volume overload. CSBIS-RBV monitoring in 9 patients with pulse ultrafiltration (pulse UF) showed distinct reproducible patterns relating to extra cellular fluid (ECF) and RBV rebound. An empirical Refill Ratio was then used to define the patterns of change and this was related to the state of their hydration. A value closer to unity was consistent with the attainment of best achievable target weight. The refill ratio fell significantly between the first (earlier) and third (last) rebound phase (1.97 ± 0.92 vs 1.32 ± 0.2). CSBIS monitoring was then carried out in 31 subjects, whilst varying dialysate composition, temperature and patient posture to analyse the effects of these changes on the ECF trace and to ascertain whether any of these interventions can trigger a change in the slope of the ECF trace distinct to that caused by UF. Only, isovolemic HD caused a change in both RBV and ECF in some patients that was explained by volume re-distribution due to gravitational shifts, poor vascular reactivity, sodium gradient between plasma and dialysate and the use of vasodilating antihypertensive agents. This has not been described previously. These will need to be explored further. The study did demonstrate a significant lack of comparability of absolute values of RECF between dialysis sessions even in the same patient. This too has not been described previously. This is likely to be due to subtle changes in fluid distribution between compartments. Therefore a relative changes must be studied. This sensitivity to subtle changes may increase the usefulness of the technique for ECF tracking through dialysis. The potential of dual compartment monitoring to track volume changes in real time was further explored in 29 patients of whom 21 achieved weight reductions and were able to be restudied. The Refill Ratio decreased significantly in the 21 patients who had their dry weights reduced by 0.95 ± 1.13 kg (1.41 ± 0.25 vs 1.25 ± 0.31). Blood pressure changes did not reach statistical significance. The technique was then used to examine differences in vascular refill between a 36oC and isothermic dialysis session in 20 stable prevalent patients. Pulse UF was carried out in both these sessions. There were no significant differences in Refill Ratios, energy removed and blood pressure response between the two sessions. The core temperature (CT) of these patients was close to 36oC and administering isothermic HD did not confer any additional benefit. Mean BNP levels in 12 patients during isovolemic HD and HD with UF did not relate to volume changes. ANP concentrations fell during a dialysis session in 11 patients from a mean 249 ± 143 pg/ml (mean ± SD) at the start of dialysis to 77 ± 65 pg/ml at the end of the session (p<0.001). During isolated UF levels did not change but fell in the ensuing sham phase indicating a time lag between volume loss and decreased generation. (136±99 pg/ml to 101±77.2 pg/ml; p<0.02) In a subsequent study ANP concentrations were measured throughout dialysis and in the post-HD period for 2 hours. A rebound in ANP concentration was observed occurring at around 90 min post-HD. The degree of this rebound may reflect the prevailing fluid state and merit further study. We have shown the utility of dual compartment monitoring with CSBIS-RBV technique and its potential in assessing volume changes in real time in haemodialysis patients. We have also shown the potential of ANP as an independent marker of volume status in the same setting. Both these techniques merit further study.

Syftet med detta examensarbete är att göra en jämförande studie mellan faktorerna som enligt en teoretisk ram påverkar en miljöinvestering och faktorerna som ingår i ett företags bedömnings-modell. Respondentbolaget begärde i ett tidigt skede att få vara anonymt och benämns därför som Företaget. Det är en multinationell koncern med verksamhet i många skilda branscher, men med fokus på norden och produkter som kan kopplas till lantbruk. Den teoretiska referensramen har sin utgångspunkt i begreppen värde och investering samt hur deras koppling till miljö och miljöinvesteringar för att identifiera de faktorer som påverkar en miljöinvestering. Faktorerna som ingår i den teoretiska referensramen och som jämförs mot respondentbolagets faktorer är:  Investeringens värdetillförsel  Investeringens miljöpåverkan  Hur investeringen påverkar produktionsförutsättningarna  Krav från samhället  Kundkrav Kopplingen däremellan bedöms enligt en femgradig skala. Informationen från Företaget inhäm-tades genom semi-strukturerade intervjuer med representanter från Företaget. Slutsatsen för detta arbete är att Företaget har identifierat samma faktorer som den teoretiska referensramen. De använder dock mätetal som inte fullt ut reflekterar faktorerna. Den största avvikelsen är bedömningen av en investerings värdetillförsel, då Företaget fullt ut införlivar det producerade värdet samt det faktum att en miljöinvestering skall ses som irreversibel. Enkelhet premieras hos Företaget och det är för att prioritera modellens användbarhet, som Företaget väl-jer att acceptera brister i bedömningsmodellen. För att förbättra bedömningsmodellen bör Företaget därför införliva nya mätetal som till större del reflekterar faktorerna som påverkar en miljöinvestering / The purpose of this master thesis is to present a comparison between the factors that affects an environmental investment. This is done through applying a theoretical framework on the factors affecting a company’s existing appraisal model for environmental investments. The company that was a part of this thesis asked at an initial stage for confidentiality, therefore it is called the Company in this thesis. The Company that contributes with the appraisal model is a multination-al group with operations in many different industries, but with a focus on the Nordic countries and products that may be linked to the agricultural sector. The theoretical framework has its base in the concepts of value and investments and their connection to the environment and the envi-ronmental investment. The identified factors in the theoretical framework are:  The investment’s addition to the value creation to the company  The investment’s environmental impact  How the investment affects the production  Demands from society  Customer demands From these, the factors affecting a company’s existing appraisal model were compared and their connection to theoretical framework was judged according to a 5-grade scale. Information from the Company was acquired through semi-structured interviews with representatives from the Company. The largest deviation is how the company considers an investment’s contribution to the produced value. Because of this imperfection does the company's model not fully incorporate the produced value and that an environmental investment is irreversible. The overall conclusion is that the Company has identified the same factors as the theoretical framework. The Company has though chosen to use their existing methods and performance indicators that don’t fully incorporate the factors in the theoretical framework. The largest devia-tions are how the company considers an investment’s contribution to the produced value and that it should be considered as irreversible. The Company must therefore in order to enhance their appraisal model develop new performance measures for the factors.

Within the worldwide business community, many analysis tools and techniques have evolved to assist in the evaluation and encouragement of financial health and fiscal viability. However, in the educational community, such analysis is uncommon. It has long been argued that educational institutions bear little resemblance to, and should not be treated like, businesses. This research identifies an educational environment where educational institutions are, indeed, businesses, and may greatly benefit from the use of business analyses. The worldwide effort of Education for All (EFA) has focused on primary education, particularly in less developed countries (LDCs). In Sub-Saharan Africa, Uganda increased its primary school enrollments from 2.7 million in 1996 to 7.6 million in 2003. This rapid primary school expansion substantially increased the demand for secondary education. Limited government funding for secondary schools created an educational bottleneck. In response to this demand, laws were passed to allow the establishment of private secondary schools, operated and taxed as businesses. Revenue reports, filed by individual private schools with the Uganda Revenue Authority, formed the database for the financial analysis portion of this research. These reports, required of all profitable businesses in Uganda, are similar to audited corporate financial statements. Survey data and national examination (UNEB) scores were also utilized. This research explored standard business financial analysis tools, including financial statement ratio analysis, and evaluated the applicability of each to this LDC educational environment. A model for financial assessment was developed and industry averages were calculated for private secondary schools in the Mukono District of Uganda. Industry averages can be used by individual schools as benchmarks in assessing their own financial health. Substantial deviations from the norms signal areas of potential concern. Schools may take appropriate corrective action, leading to sustainable fiscal viability. An example of such analysis is provided. Finally, school financial health, defined by eight financial measures, was compared with quality of education, defined by UNEB scores. Worldwide, much attention is given to education and its role in development. This research, with its model for financial assessment of private LDC schools, offers a new and pragmatic perspective.

With the proliferation of 21st century educational technologies, science teaching and learning with digitally acclimatized learners in secondary science education can be realized through an online Science-Technology-Society-Environment (STSE)-based issues approach. STSE-based programs can be interpreted as the exploration of socially-embedded initiatives in science (e.g., use of genetically modified foods) to promote the development of critical cognitive processes and to empower learners with responsible decision-making skills. This dissertation presents a case study examining the online environment of a grade 11 physics class in an all-girls’ school, and the outcomes from those online discursive opportunities with STSE materials. The limited in-class discussion opportunities are often perceived as low-quality discussions in traditional classrooms because they originate from an inadequate introduction and facilitation of socially relevant issues in science programs. Hence, this research suggests that the science curriculum should be inclusive of STSE-based issue discussions. This study also examines the nature of students’ online discourse and, their perceived benefits and challenges of learning about STSE-based issues through an online environment. Analysis of interviews, offline classroom events and online threaded discussion transcripts draws from the theoretical foundations of critical reflective thinking delineated in the Practical Inquiry (P.I.) Model. The PI model of Cognitive Presence is situated within the Community of Inquiry framework,encompassing two other core elements, Teacher Presence and Social Presence. In studying Cognitive Presence, the online STSE-based discourses were examined according to the four phases of the P.I. Model. The online discussions were measured at macro-levels to reveal patterns in student STSE-based discussions and content analysis of threaded discussions. These analyses indicated that 87% of the students participated in higher quality STSE-based discussions via an online forum as compared to in-class. The micro-level analysis revealed students to attain higher cognitive interactions with STSE issues. Sixteen percent of the students’ threaded postings were identified in the Resolution Phase 4 when the teacher intervened with a focused teaching strategy. This research provides a significant theoretical and pedagogical contribution to blended approach to STSE-based secondary science education. It presents a framework for teachers to facilitate students’ online discussions and to support learners in exploring STSE-based topics.

With the proliferation of 21st century educational technologies, science teaching and learning with digitally acclimatized learners in secondary science education can be realized through an online Science-Technology-Society-Environment (STSE)-based issues approach. STSE-based programs can be interpreted as the exploration of socially-embedded initiatives in science (e.g., use of genetically modified foods) to promote the development of critical cognitive processes and to empower learners with responsible decision-making skills. This dissertation presents a case study examining the online environment of a grade 11 physics class in an all-girls’ school, and the outcomes from those online discursive opportunities with STSE materials. The limited in-class discussion opportunities are often perceived as low-quality discussions in traditional classrooms because they originate from an inadequate introduction and facilitation of socially relevant issues in science programs. Hence, this research suggests that the science curriculum should be inclusive of STSE-based issue discussions. This study also examines the nature of students’ online discourse and, their perceived benefits and challenges of learning about STSE-based issues through an online environment. Analysis of interviews, offline classroom events and online threaded discussion transcripts draws from the theoretical foundations of critical reflective thinking delineated in the Practical Inquiry (P.I.) Model. The PI model of Cognitive Presence is situated within the Community of Inquiry framework,encompassing two other core elements, Teacher Presence and Social Presence. In studying Cognitive Presence, the online STSE-based discourses were examined according to the four phases of the P.I. Model. The online discussions were measured at macro-levels to reveal patterns in student STSE-based discussions and content analysis of threaded discussions. These analyses indicated that 87% of the students participated in higher quality STSE-based discussions via an online forum as compared to in-class. The micro-level analysis revealed students to attain higher cognitive interactions with STSE issues. Sixteen percent of the students’ threaded postings were identified in the Resolution Phase 4 when the teacher intervened with a focused teaching strategy. This research provides a significant theoretical and pedagogical contribution to blended approach to STSE-based secondary science education. It presents a framework for teachers to facilitate students’ online discussions and to support learners in exploring STSE-based topics.