Construção de eletrodo de grafite retirado de pilha comum: aplicações didáticas

This paper presents a proposal for using recycled graphite electrodes obtained from exhausted commercial 1.5 V batteries and its application in electroanalysis. The electrode could be prepared by the students and applied in the simple didactic experiments suggested, such as determination of active electrode area, cyclic voltammetry and useful potential range (also called "potential window"), demonstration and effect of scan rate on cyclic voltammograms. The possibility of using the graphite electrode in quantitative analysis was also demonstrated using the ferricyanide/ferrocyanide reversible redox couple ([Fe(CN)6]3-/[Fe(CN)6]4-) as an electrochemical probe by the dependence of peak current with the analyte concentration and flow injection analysis with amperometric detection.

Desenvolvimento de um sistema de análise por injeção em fluxo utilizando materiais alternativos de baixo custo para fins didáticos

This work describes a simple and inexpensive flow injection analysis system in which gravity force provides fluid propulsion while needles for insulin administration or metallic wires act as electrodes for amperometric detection. The proposed system was able to demonstrate the influence of several operational parameters on the transient signals. Moreover, this system was successfully used to evaluate both the stoichiometry of Cu2+-EDTA complex and the effect of pH on the kinetics of the reaction between ferricyanide and ascorbic acid. Therefore, the proposed system can be regarded as an efficient and accessible didactic tool for the teaching of FIA principles.

COMUNICAÇÃO CIENTÍFICA NO ENSINO SUPERIOR DE QUÍMICA: UMA REVISÃO

The importance of teaching scientific communication skills in undergraduate chemistry courses is well recognized. This paper provides an overview of didactic activities in which students engage to improve these skills. The study was based on an extensive literature review performed on the Journal of Chemical Education and on the Journal of College Science Teaching, in the years spanning from 1991 to 2010, and on The Chemical Educator, from 1996 to 2010. The findings from the study provided an opportunity to expand the knowledge on the variety of methods and contents used to teach scientific communication skills in undergraduate chemistry education, as well as to deepen our understanding of the effects of different approaches to teaching on performance in practice.

DESENVOLVIMENTO DE EXPERIMENTO DIDÁTICO DE ELETROGRAVIMETRIA DE BAIXO CUSTO UTILIZANDO PRINCÍPIOS DA QUÍMICA VERDE

In this paper, we describe the development of low-cost teaching experiments of electrogravimetry for undergraduate students using principles of green chemistry. Copper was electrochemically deposited on brass under an electrical current density of 50 mA cm−2 from acidic solutions containing nitrate anions. Color changes at the brass electrode and of the solution were observed, indicating that the reduction of copper ions had occurred. The deposition efficiency values were between 92.8% and 93.8%, and the electrochemical efficiency values were between 85.6% and 86.5%. There was no significant contribution from parallel reactions. These experimental conditions facilitated the didactic exploration of gravimetric and electrochemical concepts. Following the principles of green chemistry, the experiments produced no toxic substances, all the materials could be recycled, and the energy consumption was the lowest. For this reason, this experiment was considered to be very interesting for didactical purposes.

PROPOSTA EXPERIMENTAL DIDÁTICA PARA O ENSINO DE ANÁLISE DE COMPONENTES PRINCIPAIS

Principal component analysis (PCA) is a chemometric method that allows for the extraction of chemical information that would otherwise be impossible to determine. Teaching chemometrics to undergraduates can contribute to the overall professional development and training of new teachers, whose profiles have been gaining attention due to the current demand for data interpretation. In this study, a didactic experiment involving PCA is proposed. Spectrophotometry was used in the ultraviolet-visible (UV-Vis) region to assess the behavior of anthocyanins extracted from red cabbage at different pH values. The results suggest the possible separation of anthocyanin structures into three distinct groups, according to their chemical characteristics displayed in acid, neutral, and basic media. The objective is to develop educational materials targeted to undergraduate courses, which encompass a larger number of concepts and introduce instrumental techniques currently being employed in both academic research and the industrial sector. Specifically, the proposed experiment introduces concepts related to spectrophotometry in the UV-Vis range and the PCA chemometric method. The materials used are easily accessible, and UV-Vis spectroscopy equipment is less expensive in comparison with other spectroscopy methods.

Design and Implementation of MUPE Server Context Tool for Eclipse IDE

The development of software tools begun as the first computers were built. The current generation of development environments offers a common interface to access multiple software tools and often also provide a possibility to build custom tools as extensions to the existing development environment. Eclipse is an open source development environment that offers good starting point for developing custom extensions. This thesis presents a software tool to aid the development of context-aware applications on Multi-User Publishing Environment (MUPE) platform. The tool is implemented as an Eclipse plug-in. The tool allows developer to include external server side contexts to their MUPE applications. The tool allows additional context sources to be added through the Eclipse's extension point mechanism. The thesis describes how the tool was designed and implemented. The implementation consists of tool core component part and an additional context source extension part. Tool core component is responsible for the actual context addition and also provides the needed user interface elements to the Eclipse workbench. Context source component provides the needed context source related information to the core component. As part of the work an update site feature was also implemented for distributing the tool through Eclipse update mechanism.

Parallella, dynamiska representationer i gymnasiefysiken : implementering av ett interaktivt datorverktyg i didaktiska situationer och uppfattning av effektivt lärande

The computer is a useful tool in the teaching of upper secondary school physics, and should not have a subordinate role in students' learning process. However, computers and computer-based tools are often not available when they could serve their purpose best in the ongoing teaching. Another problem is the fact that commercially available tools are not usable in the way the teacher wants. The aim of this thesis was to try out a novel teaching scenario in a complicated subject in physics, electrodynamics. The didactic engineering of the thesis consisted of developing a computer-based simulation and training material, implementing the tool in physics teaching and investigating its effectiveness in the learning process. The design-based research method, didactic engineering (Artigue, 1994), which is based on the theoryof didactical situations (Brousseau, 1997), was used as a frame of reference for the design of this type of teaching product. In designing the simulation tool a general spreadsheet program was used. The design was based on parallel, dynamic representations of the physics behind the function of an AC series circuit in both graphical and numerical form. The tool, which was furnished with possibilities to control the representations in an interactive way, was hypothesized to activate the students and promote the effectiveness of their learning. An effect variable was constructed in order to measure the students' and teachers' conceptions of learning effectiveness. The empirical study was twofold. Twelve physics students, who attended a course in electrodynamics in an upper secondary school, participated in a class experiment with the computer-based tool implemented in three modes of didactical situations: practice, concept introduction and assessment. The main goal of the didactical situations was to have students solve problems and study the function of AC series circuits, taking responsibility for theirown learning process. In the teacher study eighteen Swedish speaking physics teachers evaluated the didactic potential of the computer-based tool and the accompanying paper-based material without using them in their physics teaching. Quantitative and qualitative data were collected using questionnaires, observations and interviews. The result of the studies showed that both the group of students and the teachers had generally positive conceptions of learning effectiveness. The students' conceptions were more positive in the practice situation than in the concept introduction situation, a setting that was more explorative. However, it turned out that the students' conceptions were also positive in the more complex assessment situation. This had not been hypothesized. A deeper analysis of data from observations and interviews showed that one of the students in each pair was more active than the other, taking more initiative and more responsibilityfor the student-student and student-computer interaction. These active studentshad strong, positive conceptions of learning effectiveness in each of the threedidactical situations. The group of less active students had a weak but positive conception in the first iv two situations, but a negative conception in the assessment situation, thus corroborating the hypothesis ad hoc. The teacher study revealed that computers were seldom used in physics teaching and that computer programs were in short supply. The use of a computer was considered time-consuming. As long as physics teaching with computer-based tools has to take place in special computer rooms, the use of such tools will remain limited. The affordance is enhanced when the physical dimensions as well as the performance of the computer are optimised. As a consequence, the computer then becomes a real learning tool for each pair of students, smoothly integrated into the ongoing teaching in the same space where teaching normally takes place. With more interactive support from the teacher, the computer-based parallel, dynamic representations will be efficient in promoting the learning process of the students with focus on qualitative reasoning - an often neglected part of the learning process of the students in upper secondary school physics.

Kielikylpydidaktiikkaa kehittämässä : 3-6-vuotiaiden kielikylpylasten kielellinen kehitys ja kielikylpydidaktiikan kehittäminen päiväkodissa

The goal of this study is to determine the naming ability in Finnish and Swedish of nursery school-aged children participating in a language immersion programme, as well as their command of both languages. The study also aims to describe factors reflecting language immersion teaching in nursery schools based on action research and a literature survey. The longitudinal study, conducted in 2003–2005, comprised 133 native Finnish three- to six-year-old children in language immersion programmes. A total of four measurements were carried out over two and a half years. In each measurement, four separate tests were given to each child (totally 1134 measurements). Research material was collected using survey tools that measured the children’s naming ability and command of language. The tools had been translated into both Finnish and Swedish. The material also includes taped responses related to the tool for naming ability. Didactic approaches were developed on the basis of material from action research and the literature survey. The material was examined using methodological triangulation, and a quantitative analysis was made of each survey tool. Furthermore, a content analysis of the children’s taped responses gave further depth to the description of language development. The theoretical framework of the study is mainly based on modern sociocultural theories of second language development and acquisition. Thus, the approach is both linguistic and pedagogic, with emphasis lying on the latter. The socioculturally-oriented framework of this study is mainly influenced by the theorists Vygotski, Spolsky, van Lier and Cummins. According to the results, the language skills of children in language immersion programmes develop as expected from age three to six in the fields studied. In the field of language command, the children acquired excellent skills in listening comprehension. Their naming ability was not as good. In each test, the children showed weaker skills in Swedish than in Finnish. However, based on the assumption that the two languages have a shared cognitive field, the skills in Swedish catch up with the skills in Finnish at an annual rate of 6–7 per cent. The study indicates that children meet a language development threshold one year earlier in their native language than they do in the immersion language. As for the naming ability in Swedish, problems arose from the fact that the deviation in results increases with age. Children showed creativity in their use of naming strategies. Judging by the research results, children begin to use the immersion language as a tool for thought at a very early phase. The research results, action research and literature survey were also used to create a general educational model for language immersion.

Att lära för livet hemma och i skolan : elevers uppfattningar av kost och hälsa, konsumtion och privatekonomi samt hushåll och miljö

The home is an important societal arena for upbringing and learning. A child can experience a feeling of participation in the household he or she belongs to very early in life. In this manner, the home environment constitutes an essential foundation for instruction in the subject of Home Economics. At school, Home Economics pupils should fulfill the intentions that school curriculum has for the subject, that is to say develop the knowledge, skills, and values that allow pupils to be able to take responsibility for their health, finances, comfort, and safety in their close environment. The purpose of this study is twofold. Firstly, the study aims to examine what knowledge and attitudes children and teenagers have acquired from their home environment, close environment, as well as school. Secondly, the study aims to evaluate the effects of instruction in Home Economics, at the 7th grade level, as regards diet and health, consumption and private finances, as well as household and the environment. The study’s methodological foundation focuses on pupils’ understanding of the surrounding world. A phenomenographical approach to the research phenomenon basis itself on the supposition that knowledge is fixed in human beings’ consciousness and experiences. Furthermore, the study stresses individual variations in conjunction with the experienced phenomenon. The empirical portion of the study is based on semistructured interviews of 30 pupils divided into two reference groups. The pupils were interviewed before instruction in the subject of Home Economics started and upon completing instruction. The interview data was analyzed and interpreted in accordance with the “multistage model”. The study results show that upbringing in the home environment is determinative as pertains to understanding of the socio-cultural household environment. Mealtime traditions, for example, are deeply ingrained but nonetheless influenced by lifestyle changes. The study shows that a didactic challenge exists to draw attention to the consequences of poor mealtime habits and stress for everyone raising or educating children and teenagers. Despite good knowledge of what a healthy diet is, the majority of pupils choose fast-food and junk-food when they eat out to save time and money. Studies of pupils’ preparedness for consumption show that a purposeful upbringing in the home in combination with relevant instruction in Home Economics, results in knowledgeable consumers. This study also shows that upbringing in the home environment and instruction in Home Economics requires an intense and conscious focus on the consequences of a household not run in accordance with nature, where the household lifestyle is nonsustainable. Pupils’ understanding is often based on the disregarding of the survival perspective for a comfort perspective. Parents and Home Economics teachers should be able to bring up and teach children and teenagers in a manner that allows children and teenagers to take responsibility for their health, private finances, as well as comfort and safety in the close environment. The method is conscious nurturing and instruction.

Kinetic behavior of nitrification in the post-treatment of poultry wastewater in a sequential batch reactor

A sequential batch reactor with suspended biomass and useful volume of 5 L was used in the removal of nutrients and organic matter in workbench scale under optimal conditions obtained by central composite rotational design (CCRD), with cycle time (CT) of 16 h (10.15 h, aerobic phase, and 4.35 h, anoxic phase) and carbon: nitrogen ratio (COD/NO2--N+NO3--N) equal to 6. Complete cycles (20), nitrification followed by denitrification, were evaluated to investigate the kinetic behavior of degradation of organic (COD) and nitrogenated (NH4+-N, NO2--N and NO3--N) matter present in the effluent from a bird slaughterhouse and industrial processing facility, as well as to evaluate the stability of the reactor using Shewhart control charts of individual measures. The results indicate means total inorganic nitrogen (NH4+-N+NO2- -N+NO3--N) removal of 84.32±1.59% and organic matter (COD) of 53.65±8.48% in the complete process (nitrification-denitrification) with the process under statistical control. The nitrifying activity during the aerobic phase estimated from the determination of the kinetic parameters had mean K1 and K2 values of 0.00381±0.00043 min-1 and 0.00381±0.00043 min-1, respectively. The evaluation of the kinetic behavior of the conversion of nitrogen indicated a possible reduction of CT in the anoxic phase, since removals of NO2--N and NO3--N higher than 90% were obtained with only 1 h of denitrification.

Mellom tradisjon og spel : didaktikk for tekstil folkekunst

Denne avhandlinga er resultatet av eit behov for å forske på og utvikle ein didaktikk for tekstilfaget ved Folkekunststudiet, Institutt for folkekultur, Høgskolen i Telemark, Noreg. Studiet med folkekunst som fagfelt er eit relativt ungt studium på høgskolen, som vart etablert i 1984. Problemstillinga i denne avhandlinga er korleis ein kan utvikle ein forskingsbasert didaktikk der dei grunnleggjande prinsippa som særmerkjer den tradisjonelle folkekunsten, vert tekne vare på. I arbeidet med avhandlinga har eg prøvd på å klårgjere problemstillinga ut frå ulike perspektiv. Forskingsarbeidet har fokus på kommunikasjon og arbeidsmåtar i ljos av ulike teoriar. Det er ei hermeneutisk tilnærming som er vald for den didaktiske forståinga. Det fyrste drøftingstemaet har søkjeljos på kommunikasjon og dialog ved vidareføring av tekstil folkekunst. Både estetiske, teoretiske, praktiske og sosiale aspekt er nedfelte i læreplanen for studiet og skal utgjere grunnlaget for kommunikasjon og arbeidsmåtar. I den skapande og kopierande prosessen er det utvikla språklege reiskapar for både den sosiale og den estetiske sida der den teoretiske og praktiske faktoren er integrert. Møte med døme på tekstile tradisjonar så vel som praktisk forming av tekstilar har ført til refleksjon og dialog som involverer kontemplasjon, korrespondens og imaginasjon. Det andre temaet som er drøfta, er vidareføring av tradisjonelt visuelt formspråk. Her er merksemda retta mot kva som har skjedd formalt med ei gruppe tradisjonelle formelement i tekstilar i den institusjonelle vidareføringa over eit lengre tidsperspektiv. Resultatet syner at mange tradisjonelle formelement er borte frå den institusjonelle produksjonen. Formelementa kan ha fått ei meir naturalistisk utforming, eller dei er overførte til andre tradisjonelle tekstilteknikkar enn dei som var utgangspunktet. Rombeforma i den institusjonelle produksjonen er utført i færre variasjonar og kombinasjonar enn i den tradisjonelle produksjonen. Konklusjonen på drøftingstemaet er at spelereglar og spatialitet i høve til den formale komponenten i utvalet med tradisjonelle tekstilar ikkje er vidareført i alle gruppene av institusjonelle produkt. Resultatet kan få innverknad og fylgjer for utforming av ein framtidig didaktikk for faget. Arbeidsmåte og erfaring frå vidareføring av tekstile tradisjonar er det tredje temaet som er drøfta i avhandlinga. Kopiering og skapande prosessar er arbeidsmåtar som er brukte ved studiet i dag, og dei utgjer grunnlag for drøftingar i relasjon til vidareføring og erfaring. Konklusjonen er at i den skapande prosessen korrigerer tradisjonen utforminga, medan i kopiprosessen er eigen stilvilje og improvisering resultat av prosessane. Personar som deltek i prosessane, har sett seg sjølve og si historiske forankring inn i spelet, der visuelt og verbalt språk er resultat av integrasjon av tradisjonar. Dei tre drøftingstemaa utgjer grunnlaget for at didaktikk for folkekunst og tekstil kan bli intersubjektiv forståing av kva ein didaktikk for vidareføring av folkekunst med vekt på tekstil kan vere i utdanninga i dag. Indre og ytre dialog i skapande og kopierande prosessar femner om estetiske, materielle og tekniske faktorar sett i høve til spelereglar, spelerom, spatialitet og samspel i møte med tekstile tradisjonar. Samla utgjer det ein forskingsbasert didaktikk for faget der den overordna intensjonen er samtykke mellom tradisjon og spel.

Eleven som aktør i dialog med kunst : ungdoms erfaring med kunstundervisningens innhold og metode i faget kunst og håndverk i norsk grunnskole

Avhandlingen har sitt utspring i mitt engasjement for elevers møte med kunst i grunnskolen i faget kunst og håndverk og mitt syn på ungdom som kompetente bidragsytere til forskningen om fenomener som angår deres liv. Elevene er informanter til, eller aktører i, forskning på fenomenet dialog med kunst. Dialog med kunst er her definert som en helhetlig prosess som innlemmer alt fra elevenes møte med visuelle kunstverk til deres eget skapende arbeid. At avhandlingens fagdidaktiske problemområde er elevers praktisk skapende virksomhet, knytter undersøkelsen til slöjdpedagogisk forskning. Avhandlingens overgripende hensikt er å bidra til utvikling av fagdidaktikken i kunst og håndverk med utgangspunkt i elevenes erfaringer med kunstundervisningens innhold og metode på ungdomsskoletrinnet. Studien består av kasusstudier på to ungdomsskoler. Data ble innsamlet igjennom intervjuer, deltakende observasjon, dokumenter, prosessbøker og foto av formingsprodukter. Ungdoms dialog med kunst i skolen blir analysert og fremstilt ut fra et erfart og et operasjonalisert perspektiv. Funnene speiles i ulike fagdidaktiske tendenser, det vil si ulike hovedoppfatninger i debatten om det moderne samfunn, og i et virksomhetsteoretisk perspektiv. Resultatene fra undersøkelsen utfordrer oss til en fagdidaktisk nyorientering når det gjelder ungdoms møte med kunstverk i skolen, i retning av et mer ungdomskulturelt innhold og relasjonelle kunstmøter som er narrative, tolkningsorientert, opplevelsesorientert, dialogiske og flerstemmige. Undersøkelsen viser at elevene liker det praktisk skapende arbeidet, men at undervisningen i sterkere grad bør ta i bruk digital kunnskap og handle om hvordan kunst kan brukes som utgangspunkt for skapende arbeid, og den bør legge til rette for det læringspotensialet som ligger i dialogen elevene imellom. Elevene liker en undervisning som ikke bare handler om estetiske virkemidler, materialer og teknikker, men også om kommunikasjon og ytringsfrihet. Resultatene viser at det frie skapende arbeid består av tre likeverdige aspekter: det individuelle, det kulturelle og det sosiale. Både funnene og avhandlingens virksomhetsteoretiske perspektiv kan bidra til diskursen om kreativitetsbegrepet og identitetskonstruksjon i vårt moderne samfunn. Virksomhetssystemet blir i denne avhandlingen utviklet til en teori for skapende arbeid i faget kunst og håndverk, et overgripende fagdidaktisk rammeverk for bild/bildkonst og slöjdfaget satt inn i et nordisk utdanningsperspektiv.

Litteratur och livskunskap : modersmålslärarens berättelse om undervisningen i årkurs 7-9

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Käsinhitsauksen mekanisointiratkaisujen kehittäminen

Työn tavoitteena on kehittää asiakkaiden käsinhitsausta kartoittamalla heidän hitsaavaa tuotantoa, sekä sen mahdollisia ongelmia. Järjestettävän hitsauskokeen avulla mitataan mekanisoidun hitsauksen tuottavuutta, laatua ja työergonomiaa. Työ sisältää teoreettisen ja käytännöllisen osuuden. Teoreettinen osuus pohjautuu kirjallisuuteen ja käytännöllinen osuus eri yrityksien kyselyihin ja haastatteluihin sekä hitsauskokeeseen. Teoreettinen osuus käsittelee käsinhitsausta ja siihen liittyviä mekanisointiratkaisuja. Käsinhitsauksessa käsitellään yleisimmät käsinhitsausprosessit, käsinhitsattava tuote ja tuotanto sekä sen tuottavuutta. Mekanisointiratkaisuissa käsitellään yleisimmät mekanisointiratkaisut ja laitteet sekä käytännön toteutusta. Käytännöllisessä osuudessa yritykset pitivät nykyisin hitsauksessa tärkeimpänä hitsaajien ammattitaitoa, tuottavuutta, työn mielekkyyttä, laatua sekä työturvallisuutta. Yrityksien tulisi tarkastella tuotannossaan hitsaussolujen sisältöä, sisäistä logistiikkaa ja kappaleiden kiinnitystä. Kappaleenkäsittelijään yrityksiltä tuli paljon kehitysideoita, kuten kiinnitykseen valmiita ratkaisuja sekä pöytälevyyn erilaisia vaihtoehtoja. Hitsauskokeen perusteella kappaleenkäsittelijällä työaika oli 29,4 % pienempi kuin työpöydällä. Laadullisesti koe antoi myös positiivisia tuloksia, käsittelypöydässä hitsattuja rakenteita ei tarvinnut korjata, mutta normaalissa työpöydässä piti, jotta C –luokan vaatimukset täyttyivät. Työturvallisuuden ja ergonomian kannalta suurimmat hyödyt olivat hyvä työasento, huurujen ja kurkottelun vähentyminen, mahdollisten palovammojen vähentyminen sekä vähemmän vaaraa osien putoamisesta.

A Distributed Microservices Framework Integrating Taverna

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014