Retrieval of kinetic rates in reactions with semi batch liquid phase using ill-posed inverse problem theory

A neural network procedure to solve inverse chemical kinetic problems is discussed in this work. Rate constants are calculated from the product concentration of an irreversible consecutive reaction: the hydrogenation of Citral molecule, a process with industrial interest. Simulated and experimental data are considered. Errors in the simulated data, up to 7% in the concentrations, were assumed to investigate the robustness of the inverse procedure. Also, the proposed method is compared with two common methods in nonlinear analysis; the Simplex and Levenberg-Marquardt approaches. In all situations investigated, the neural network approach was numerically stable and robust with respect to deviations in the initial conditions or experimental noises.

A brief introduction to molecular orbital theory of simple polyatomic molecules for undergraduate chemistry students

A simple, four-step method for better introducing undergraduate students to the fundamentals of molecular orbital (MO) theory of the polyatomic molecules H2O, NH3, BH3 and SiH4 using group theory is reported. These molecules serve to illustrate the concept of ligand group orbitals (LGOs) and subsequent construction of MO energy diagrams on the basis of molecular symmetry requirements.

Evaluation of group electronegativities and hardness (softness) of group 14 elements and containing functional groups through density functional theory and correlation with NMR spectra data

Quantum Chemical calculations for group 14 elements of Periodic Table (C, Si, Ge, Sn, Pb) and their functional groups have been carried out using Density Functional Theory (DFT) based reactivity descriptors such as group electronegativities, hardness and softness. DFT calculations were performed for a large series of tetracoordinated Sn compounds of the CH3SnRR'X type, where X is a halogen and R and R' are alkyl, halogenated alkyl, alkoxy, or alkyl thio groups. The results were interpreted in terms of calculated electronegativity and hardness of the SnRR'X groups, applying a methodology previously developed by Geerlings and coworkers (J. Phys. Chem. 1993, 97, 1826). These calculations allowed to see the regularities concerning the influence of the nature of organic groups RR' and inorganic group X on electronegativities and hardness of the SnRR'X groups; in this case, it was found a very good correlation between the electronegativity of the fragment and experimental 119Sn chemical shifts, a property that sensitively reflects the change in the valence electronic structure of molecules. This work was complemented with the study of some compounds of the EX and ER types, where E= C, Si, Ge, Sn and R= CH3, H, which was performed to study the influence that the central atom has on the electronegativity and hardness of molecules, or whether these properties are mainly affected for the type of ligand bound to the central atom. All these calculations were performed using the B3PW91 functional together with the 6-311++G** basis set level for H, C, Si, Ge, F, Cl and Br atoms and the 3-21G for Sn and I atoms.

Leibniz's theory of bodies: monadic aggregates, phenomena, or both?

Leibniz's conception of bodies seems to be a puzzling theory. Bodies are seen as aggregates of monads and as wellfounded phenomena. This has initiated controversy and unending discussions. The paper attempts to resolve the apparent inconsistencies by a new and formally spirited reconstruction of Leibniz's theory of monads and perception, on the one hand, and a (re-)formulation and precisation of his concept of preestablished harmony, on the other hand. Preestablished harmony is modelled basically as a covariation between the monadic and the ideal realm.

Benjamin's conception of language and Adorno's aesthetic theory

According to the theory of language of the young Benjamin, the primary task of language isn't the communication of contents, but to express itself as a "spiritual essence" in which also men take part. That conception according to which language would be a medium to signification of something outside it leads to a necessary decrease of its original strength and is thus denominated by Benjamin bürgerlich. The names of human language are remainders of an archaic state, in which things weren't yet mute and had their own language. Benjamin suggests also that all the arts remind the original language of things, as they make objects "speak" in form of sounds, colors, shapes etc. That relationship between arts as reminders of the "language of things" and the possible reconciliation of mankind with itself and with nature has been developed by Theodor Adorno in several of his writings, specially in the Aesthetic Theory, where the artwork is ultimately conceived as a construct pervaded by "language" in the widest meaning - not in the "bourgeois" sense.

THE FORMAL AND THE FORMALIZED: THE CASES OF SYLLOGISTIC AND SUPPOSITION THEORY

As a discipline, logic is arguably constituted of two main sub-projects: formal theories of argument validity on the basis of a small number of patterns, and theories of how to reduce the multiplicity of arguments in non-logical, informal contexts to the small number of patterns whose validity is systematically studied (i.e. theories of formalization). Regrettably, we now tend to view logic 'proper' exclusively as what falls under the first sub-project, to the neglect of the second, equally important sub-project. In this paper, I discuss two historical theories of argument formalization: Aristotle's syllogistic theory as presented in the "Prior Analytics", and medieval theories of supposition. They both illustrate this two-fold nature of logic, containing in particular illuminating reflections on how to formalize arguments (i.e. the second sub-project). In both cases, the formal methods employed differ from the usual modern technique of translating an argument in ordinary language into a specially designed symbolism, a formal language. The upshot is thus a plea for a broader conceptualization of what it means to formalize.

Rebuilding Defenses: Explorations in Norman Fairclough’s Theory of Critical Discourse Analysis

Tutkielmassa eritellään Norman Faircloughin kriittisen diskurssianalyysin teoriaa ja siihen kohdistettua kritiikkiä. Pyrkimyksenä on sovittaa näitä erilaisia näkemyksiä keskenään ja tarjota ratkaisuja yhteen kiriittisen diskurssianalyysin keskeiseen ongelmaan eli emansipaation (sosiaalisten epäkohtien tunnistamisen ja ratkaisemisen) puutteellisuuteen. Teoriaosuudesta esiin nousevia mahdollisuuksia sovelletaan tekstianalyysiin. Tutkimuksen kohteena on teksti Rebuilding America’s Defenses: Strategy, Forces and Resources For a New Century ja jossain määrin sen tuottanut järjestö Project for the New American Century. Näitä tarkastellaan ennen kaikkea sosiaalisina ilmiöinä ja suhteessa toisiinsa. Faircloughin mallin suurimmiksi ongelmiksi muodostuvat perinteinen käsitys kielestä, jonka mukaan kielen järjestelmän abstraktit ja sisäiset suhteet ovat tärkeimpiä, sekä ideologinen vastakkainasettelu kritiikin lähtökohtana. Ensimmäinen johtaa kielellisten tutkimustulosten epätyydyttävään kykyyn selittää sosiaalisia havaintoja ja jälkimmäinen poliittiseen tai maailmankatsomukselliseen väittelyyn, joka ei mahdollista uusia näkemyksiä. Tutkielman lopputulema on, että keskittymällä asiasisältöön kielen rakenteen sijasta ja ymmärtämällä tekstin tuottaja yksittäisenä, rajattuna sosiaalisena toimijana voidaan analyysiin saada avoimuutta ja täsmällisyyttä. Kriittiinen diskurssianalyysi kaipaa tällaista näkemystä kielellisten analyysien tueksi ja uudenlaisen relevanssin löytääkseen.

Curriculum innovation in teacher education : exploring conceptions among Tanzanian teacher educators

The focus of the study is to understand curriculum innovation from the perspective of Tanzanian teacher educators. It is argued that the deterioration of quality of education in schools is partly to be attributed to the way in which teachers are educated. Curriculum innovation is considered as an essential strategy for bringing about improvement in teacher education. Therefore, in 2000 a new curriculum was introduced; however, right from the inception the curriculum was criticised by teacher educators. The overall aim of the study is to investigate teacher educators’ conceptions of curriculum innovation. In the theoretical framework the main focus is on discussion about different curriculum approaches for teacher education and innovation. In order to achieve the aim of the study, a phenomenographic approach is employed. This approach is used in order to identify similarities and variation in educators’ conceptions of curriculum innovation. The empirical basis of the study consists of interviews with thirty teacher educators working in eight teachers’ colleges situated in various parts of Tanzania. The findings, in brief, reveal variation in teacher educators’ conceptions of the dominant domains of innovation. Two broad conceptions of teaching with six aspects are identified. Conceptions of educational studies are presented in four broad categories of description with four aspects. Similarly, in methodology subjects two conceptions are described with four aspects. On the integration of subject matter studies and subject methods, two broad conceptions are presented with six aspects. Conceptions of textbook prescription policy are characterised in two broad categories of description with four aspects. With the use of modules two broad conceptions are identified with six aspects. In addition, the study identifies four broad conceptions of future curriculum approaches with eight aspects. Looking across the categories of description, the results indicate that educators cope with innovation individually. Three character types of teacher educators are presented: loyal, creative and critical. Furthermore, four types of phenomena suggesting critical areas about teacher educators’ conceptions of innovation are described: educators’ prior educational background, technical factors, student teachers’ factors and shifting from teaching to learning. On the whole, educators express a number of frame factors in the process of change towards the aim of curriculum innovation. This indicates that the new curriculum (2000) is not implemented as intended by curriculum developers. Constraints to the implementation are presented and discussed in detail. From these findings, two models of educators’ stance towards curriculum innovation are presented and can be used as a framework for planning successful curriculum innovations and analysing practice in teachers’ colleges.

Under ytan, vid ytan och ovanför ytan : analys av tanken bakom tre läromedel i slöjd

This thesis is based on the personal experience gained related to the planning and production of three web-based teaching materials for the teaching subject knownas sloyd at the comprehensive school in Finland. After the teaching materials had been produced and published on the Internet at the Finnish textile teachers' website KässäBoxi, the idea for this thesis emanated from the questions: Why do the three teaching materials look the way they do and why do other textile teachers comment that they are different? In earlier sloyd educational research it has been stated that a scientific paradigm affects the individual ideology of a sloyd teacher. The aimfor my doctoral thesis is to continue on the topic. As the area of interest comprises the thought behind three teaching materials in sloyd, the aim of the thesis is to show how teaching and educational ideologies in sloyd appear in the teaching materials at hand. The research approach has parallels to research about another, tangible phenomena, namely the iceberg. In a similar way as an iceberg, a teaching material has a profound base, but the base is not always completely visible to the user of the teaching material. In this thesis I strive to show what there is under the surface, on the surface and above the surface of three teaching materials in sloyd. The research approach is defined as qualitative and phenomenologic-hermeneutic. The analysis results in knowledge about how the producer of a teaching material affects the character of a teaching material by choices concerning for example the form, structure, language and illustrations of the teaching material. The analysis also shows how the producers' individual educational and teaching ideologies within the teaching subject at hand appear by means of traces concerning the view on the pupil and the teacher, and the view on planning and conducting teaching in sloyd. The thesis also results in knowledge about how sloyd educational scientific theories and demands from society, as they are stated in the national core curriculum, appear in the three teaching materials. The application of the sloyd educational scientific theory of individual sloyd activity as a holistic educative system is also widened in the thesis. This thesis contributes to future research on producing teaching materials by information about what aspects a producer of teaching materials needs to consider and how the aspects become visible in the teaching materials. This kind of knowledge is valuable to teacher students in sloyd, to teachers in sloyd who intend to plan and produce teaching materials and to teachers who tutor the planning and production of teaching materials.