In recent years, bio-based polymers derived from renewable resources have become increasingly important as sustainable and eco-efficient products which can replace the products based on petrochemical-derived stocks. The objective of our work was to develop novel bio-based reactive systems suitable for high performance composite materials especially epoxy systems. The most commonly used starting monomer to formulate epoxy networks is the diglycidyl ether of bisphenol A, DGEBA, derived from bisphenol A and epichlorohydrin. Bio-based epichlorohydrin is commercially available. So the challenge to obtain a fully bio-based epoxy prepolymer is to replace bisphenol A by a bio-based precursor. Another interest for replacing bisphenol A by a bio-based precursor is that bisphenol A has been known to have estrogenic properties. In this study, we studied different bio-based epoxy systems and compared them to a classical DGEBA based system using, in a first step, isophorone diamine (IPD) as conventional curing agent. Bio-based epoxy prepolymers were derived from natural sugars, sorbitol and isosorbide respectively. Sorbitol polyglycidyl ether is available commercially, while isosorbide diglycidyl ether was synthesized either via conventional epoxidation (i.e. using epichlorohydrin) or via the diallyl isosorbide intermediate. Another bio-based epoxy prepolymer was derived from cardanol and is also a commercial product. Chemical structure of the bio-based epoxy prepolymers were analyzed by different analytical methods, gelation and crosslinking reactions were studied using rheological measurements and differential scanning calorimetry, respectively. Properties of the cured networks were evaluated using dynamic mechanical analysis and thermo gravimetric analysis. Influence of the bio-based epoxy prepolymer structure on the system properties as well as the influence of the crosslinking agent structure (either derived from renewable resources or bio-based ones) was discussed. Water absorption of the bio-based networks was also studied.

Konjunkcija – loginiai prasminiai ryšiai tarp dviejų sakinių, realizuojami formaliomis sakinių siejimo priemonėmis, išreiškiančiomis tam tikrus santykius. Konjunkcijos raiškos priemonių gretinimui pasirinkti dviejų skirtingų funkcinių stilių – meninio ir administracinio – tekstai. Konjunkcija skirstytina į du tipus: tipiškąją ir modalinę. Tipiškąja konjunkcija reiškiami santykiai yra grynieji, jais nenusakomas joks vertinimas ar santykis su tekstu. Pagal tai, kokias funkcijas tekste atlieka loginės semantinės (prasminės) sakinių siejimo priemonės, skiriami keturi tipiškosios konjunkcijos potipiai: sudėjimo, priežasties, priešinamoji ir laiko konjunkcija. Modalinės konjunkcijos siejimo priemonės ne tik susieja sakinius kokiu nors santykiu, bet taip pat nusako ir tam tikrą adresanto požiūrį į sakomą dalyką, turi subjektyvumo atspalvį; ją realizuojančios siejimo priemonės gali išreikšti abejojimą, įsitikinimą, pabrėžimą ar reikšti informacijos šaltinį. Tirtų konjunkcijos atvejų analizė leidžia daryti tokias išvadas: 1) Gausiausia tirtuose tekstuose – sudėjimo konjunkcija (45%). Dažniausias sudėjimo santykis – turinio papildymas – meninio stiliaus tekste reiškiamas sudedamuoju jungtuku ir, administracinio stiliaus tekste – jungtuku tačiau. 2) Pridūrimo konjunkcija būdinga tik meninio stiliaus tekstams, nes atlieka ekspresinę funkciją. 3) Administracinio stiliaus tekste labai dažnas iliustruojamasis santykis, realizuotas įterpiniu pavyzdžiui. Tai lemia analizuoto teksto... [toliau žr. visą tekstą] / A conjunction is a logical semantic link between two sentences, realized with the formal devices for connecting sentences, and expressing certain relations. Two different styles of texts were chosen for the comparison of the devices used to express a conjunction, which are literary texts and administrative texts. Conjunctions are divided into two types: typical and modal. A typical conjunction expressing relation are pure, and with them no judgement or link with the text is defined. There are four sub-types of typical conjunctions according to the functions the logical semantical devices for connecting sentences perform in the text, which are additive, causal, adversative and temporal conjunctions. The linking device for a modal conjuntion do not only link sentences by a relation, but also define a certain point of view by the addresser towards something that is said, and has a hint of subjectivity; the connecting tools realizing it can express doubt, certainty, emphasis or stand for an informational source. The analysis of the cases of the conjuntions studied allow one to make the following conclusions: 1. The most conjunctions found in the texts analysed were additive conjuntions (45 %). The most common building relationship – extension – in an literary text is expressed by using the building conjuntion ir (“and”), and in administrative texts with the conjunction tačiau (“however”). 2. Enhancement conjunctions are characteristic only for literary texts, because they... [to full text]

Magistro darbe pateikiama užimtumo politikos raida, įstojimo į Europos Sąjungą poveikis Lietuvos darbo rinkai, nagrinėjamas užimtumo politikos projektų finansavimas, pateikiama institucijų, atsakingų už užimtumo rėmimo politikos įgyvendinimą, funkcinė analizė. Atliekama Lietuvos Respublikos teisinės bazės, turinčios įtakos užimtumo rėmimo politikos valdymui, analizė. Magistro darbe pateikiama užimtumo politikos įgyvendinimo analizė Radviliškio darbo biržoje 2006-2007 metais: atlikta darbo jėgos paklausos ir pasiūlos suderinamumo, nedarbo, aktyvių darbo rinkos politikos priemonių analizė, pateikta darbo rinkos pokyčių prognozė. Pateikiamos išvados ir rekomendacijos. Patvirtinama autoriaus suformuluota mokslinio tyrimo hipotezė, kad užimtumo rėmimo politikos strategija daro tiesioginę įtaką šalies gyventojų užimtumo efektyvumui. / In this postgraduate work we submit the course of employment policy, the influence of joining the European Union to Lithuanian job market, analyse the financial part of employment policy. We also make the functional analysis of institutions, which are responsible for the employment . In this postgraduate work we study the implementation of the employment policy in Radviliskis Employment Agency in 2006-2007: we analyse the compatibility between demand and supply, unemloyment, the actions and prognosis of changes in the job market. We give the conclusion and recomendations. We prove the hypothesis of the research, that the strategy towards maintenance of emloyment policy influences the effectiveness of emloyment.

Summary The paper analyses the problems that occur in the relationship between families, which raise blind children, and medical (or other) specialists and indicates the possible directions of improving and deepening these relations. The purpose of the paper: to analyse the experience of the relationship between the families, which raise the children with visual disabilities, and medical specialists. The subject of the paper: what is the experience of the relationship between the families, raising blind children, and medical specialists in the process of helping the child. The paper tried to purify the experience of each family, to sense the meanings, which parents endow their empathies with, to ascertain what suspenses and hopes they foster. The qualitative analysis was taken for analysing the experience of the families and the specialists and the instrument for compilation the data was a qualitative interview. 7 women, raising the children with visual disabilities, participated in the research. The problems are researched in three aspects: firstly, the factors are identified, which help or disturb the families, raising the blind children, to overcome the psychological and spiritual discomfort, which is connected with the birth of the disabled child and his/her development, and which can have the influence to the health of the family members; secondly, the efforts are made to reveal the real requirements of these families, which are related to the services of medical and... [to full text]

Natural convective heat transfer from flat plates and short cylinders inclined at an angle to the vertical in laminar and transition flow regions with isothermal or constant heat flux conditions have been numerically and experimentally studied. When the width of the plate is relatively small compared to its height, i.e., the plate is narrow, the heat transfer rate can be considerably greater than that predicted by these two-dimensional flow results. When the narrow plate is inclined to the vertical, pressure changes normal to the plate surface arise and these pressure changes can alter the nature and the magnitude of the edge effects. When two narrow inclined rectangular flat plates of the same size separated vertically or horizontally, the flow interaction between these heated plates can have a significant effect on the heat transfer. When relatively small square and circular cylinders with exposed top surfaces inclined to the vertical are used, the interaction of the flow over the surfaces that make up the cylinder and inclination angle have, in general, a considerable effect on the magnitude of the mean heat transfer rate and on the nature of the flow over the cylinder surfaces. In the present numerical studies it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated using the Boussinesq approach. The numerical solution was obtained by numerically solving the full three-dimensional form of the governing equations, these equations being written in dimensionless form. The solution was obtained using a commercial CFD code, FLUENT. Results were only obtained for a Prandtl number of 0.7; this being approximately the value of air. In the experimental studies, the average heat transfer rates from cylinders were determined by the transient method, which involves heating the model and then measuring its temperature-time variation while it cools. The average heat transfer rates from the flat plates were determined using a steady state method, which basically involved electrically heating the plate. The tests were carried out inside a large enclosure. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2011-06-27 19:27:45.724

Abstract Adding a dc circuit to an existing transmission line is one method of significantly increasing the power transfer capability of a transmission corridor. The resulting hybrid system has significant coupling between the ac and dc circuits, not only because of the proximity of the circuits, but also from the fact that they may share the same sending end or receiving end ac systems. The resultant interaction produces overvoltages on the dc system which can be somewhat higher than for a conventional dc scheme. This thesis investigates the overvoltages on a hybrid ac-dc transmission system and suggests some design considerations which could be taken into account to reduce stresses on certain critical components which result from such an arrangement. Blocking filters consisting of a parallel L-C combination in series with the dc converter were included to limit the flow of fundamental frequency current in the dc line. This thesis also investigates the proper blocking filter configuration to be used as an incorrectly chosen blocking filter can cause resonance overvoltages on the dc line at fundamental frequency. A method of eliminating dc components of the currents in the transformer windings of a dc converter is presented. The method uses the technique of firing angle modulation. It is shown that merely eliminating the fundamental frequency component on the dc side may not remove this dc component. The impact of such control action at one converter on the other converters in the dc transmission system is also presented. It is also shown that the undesirable side effects of such a scheme include increased generation of non-characteristic harmonies on both the ac and dc sides. The study is performed using an electromagnetic transients simulation program and theoretical calculations.

There has been considerable research into the teaching and learning of argumentation (e.g. Andrews, 2009; Sadler, 2004), focusing on strategies designed to help students to structure their written arguments. My study, however, focuses on the process of argumentation because I want to help sixth form students, aged 16-19 years old, improve the written argument in their A level History essays. The methodological approach followed was an adapted form of Design-based research, which incorporated an exploratory study, teacher trials and three case studies as part of the iterative design process. A classroom intervention was devised underpinned by design principles based in persuasive argumentation (Kuhn, 2005) and dialogic talk (Wegerif, 2012), derived from an extensive literature review, and the findings of the exploratory study. The exploratory study involved interviews with History education academics and examiners as well as classroom observations and semi-structured interviews conducted in collaboration with the teachers and students of four secondary History departments. Observations were taken of the teacher trials of the prototype intervention, whereas the data gathered from the case studies included pre and post intervention essays, audio and video recordings of the developed intervention in action, post intervention student interviews and questionnaires as well. In Case study 1 and 2, AS and A2 students’ post-intervention causation essays, when measured for argumentation, showed improvement but those whose written arguments improved the most were those students who had engaged in interactions rich in dialogic talk (Wegerif, 2012). The findings from Case study 3, which involved the integration of documentary evidence into AS History essays, were unexpected. Students found the integration of source-based evidence difficult not only during the course of the spoken argumentation but also in their written responses. Further development of the intervention is necessary to help students handle source material effectively in both the spoken and written forms of argument.

Mokyklos aplinka yra pirmoji institucija, kurioje vaikas išmoksta atlikti pilietines pareigas, perima visuomenines vertybes, įpranta bendrauti ir bendradarbiauti su kitais žmonėmis. Siekiant, kad vyktų sėkmingas vaiko ugdimasis, ypatingai svarbu puoselėti darnius pedagogų ir ugdytinių tarpusavio santykius. Šiandien tarpusavio santykių problema mokymo įstaigose itin aktuali: atkreipiamas dėmesys į prastėjančius pedagogų ir ugdytinių tarpusavio santykius, dažnai peraugančius į konfliktus. Tyrimo objektas: Pedagogų ir ugdytinių tarpusavio santykiai. Tyrimo tikslas. Išsiaiškinti paauglių požiūrį į veiksnius, gerinančius pedagogų ir ugdytinių tarpusavio santykius. Pagrindiniu tyrimo metodu buvo pasirinkta atviro tipo anketinė apklausa, skirta paaugliams. Paauglių apklausos tyrimo tikslui realizuoti pasirinkta kokybinė tyrimo prieiga. Anketos klausimai buvo sudaryti, siekiant išsiaiškinti paauglių požiūrį į veiksnius, gerinančius pedagogų ir ugdytinių tarpusavio santykius. Anoniminės anketos buvo išdalintos 26 paaugliams: 13 anketų – dienos centrą lankantiems vaikams, kitos 13 – gimnazijos moksleiviams. Tyrime dalyvavę respondentai buvo pasirinkti atsitiktine tvarka. Duomenų rezultatai pateikiami paveiksluose ir lentelėse. Tyrimui atlikti buvo naudojamas content analizės anketinės apklausos metodas. Tyrimo rezultatai parodė, kad paauglių ir pedagogų tarpusavio santykius gerintų šie veiksniai: objektyvus pedagogų vertinimas (grįstas sąžiningumu, o ne asmeniniais sumetimais)... [toliau žr. visą tekstą] / The school environment is the first institution in which the child learns to perform civic duties, takes over social values, gets accustomed to communicate and collaborate with other people. In order to run a successful child development, it is essential to foster harmonious teacher-pupil relationships. Today, the problem of the relationships in the educational institutions is particularly urgent: attention is drawn to further deterioration of teachers’ and pupils’ relationships, often growing into conflicts. Object of the study: relationships of teachers and pupils. Aim of the study. To figure out teens’ attitudes on the factors enhancing teachers’ and pupils’ relationships. As the main research method, open-ended questionnaire was chosen, designed for teenagers. To realize teen survey, qualitative research access was selected. Interview questions were made in order to determine adolescent attitudes on factors enhancing teachers’ and pupils’ relationships. An anonymous questionnaire was distributed to 26 adolescents: 13 questionnaires to the children attending day care centre and other 13 to gymnasium students. Respondents in the study were chosen at random. The results are presented in figures and tables. Content analysis questionnaire survey was used as the research method. The results showed that the relationship between adolescents and teachers would improve thanks to these factors: objective evaluation by the teachers (based on fairness rather than personal reasons)... [to full text]

With the entrepreneurial milieu in Linnaeus University (Växjö), students are encouraged to get involved in entrepreneurial activities. The number of student entrepreneurs has been increasing recent years. However, there is a blank in the study of student entrepreneurs. The entrepreneurial education system and the features of student entrepreneurs are the focus of the research about student entrepreneurs. At the same time, no sufficient study has been done about student entrepreneurs’ usage of the business support that could be offered to them. By studying student entrepreneurs’ situation, their relationship with support agencies, their selection of business support and the way they use the support, the research question ”how do student entrepreneurs use support agencies” will be answered by the end of this thesis.

Several mechanisms have been proposed to explain the process of vein pattern formation in plant tissues. The most widely accepted amongst biologists is the canalization hypothesis, derived from pea root and stem experiments. According to this hypothesis, a signal, thought to be the phytohormone auxin, is transported polarly from cell to cell from the shoot to the root and is canalized progressively into narrow channels of high auxin fluxes that later differentiate to become vascular tissue. In this project, we set out to test whether auxin canalization drives vein pattern formation, using Arabidopsis thaliana mutants with increased auxin transport (max4-1, max3-9, max2-1 and max1-1). We predicted that the mutants would have distinct vein patterns and especially different angles between the primary and secondary veins, compared to the wild type. First rosette leaves of 15 plants per genotype were harvested for analysis each day from 7 to 17 days after sowing, giving a total of eight hundred twenty-five leaf samples to analyze. Venation patterns were extracted and analyzed using custom-made software written with Matlab. Overall, compared with the wild type, mutants with the highest auxin transport (max4-1 and max3-9) had different vein patterns at early developmental stages, confirming a role for auxin transport in vein patterning. However, veins of mutants and wild type connected at similar angles, which is not consistent with the auxin canalization hypothesis, as originally formulated.