Coagulação/floculação de suspensões ricas em óxidos de ferro por sulfato de alumínio

The destabilization mechanism of suspensions of positively charged iron oxide particles by aluminum sulphate was investigated, aiming to evaluate the efficiency of the latter as a coagulant for natural surface waters from iron ore mining plants. Synthetic waters that simulate natural suspensions were used. The best coagulant dosage was found to be 100 mg/L at pH 4. The specific adsorption of hydrolysis products of aluminum salts on iron oxide particles and heterocoagulation processes involving differently charged substrates are proposed to explain the turbidity reduction of the suspensions.

Adsorção de As, Cu, Pb e Cr na avaliação da capacidade de fixação de metais por resíduo de mineradoras de ferro

Two samples of residues from iron mining plants have been investigated for their retention capacity of As, Cu, Cr, and Pb. The sample with the higher content of iron oxides showed the highest capacity to retain metals. The adsorption affinity series changes from Pb>Cu>Cr~As to As>Pb>Cu>Cr or As>Cu>Cr>Pb, depending on the material and the concentration of the initial solution. In the competitive environment, the Pb adsorption decreases and the As, Cu and Cr adsorption increases. Sequential extraction procedures, carried out after adsorption batch experiments, showed that the most important adsorption process occurs in the oxide fraction and that the major part of the absorbed metal is remobilized from exchangeable and oxide fractions.

Distribuição, fracionamento e mobilidade de elementos traço em sedimentos superficiais

The gold and iron mining activities in the Velhas River yield considerable amounts of suspended solids as well as metals to the hydrological system of the region. The risks were assessed by sequential extraction procedures. They were carried out in sediment samples, aiming to evaluate the presence of Co, Cr, Cu, Ni, Zn and As. Although being at high levels in some parts of the river (e.g. As 527 mg g-1 and Cr 475 mg g-1) they are associated with the residual fraction. Mobility factors were also calculated and show that these species are enriched along the river, e.g. for As 0.02 at the spring and 0.33 at the high course of the river.

Determinação de benzeno, tolueno, etilbenzeno e xilenos em gasolina comercializada nos postos do estado do Piauí

Automotive gasoline consists of a complex mixture of flammable and volatile hydrocarbons derived from crude oil with carbon numbers within the range of 4-12 and boiling points range of 30-225 ºC. Its composition varies with the kind of crude oil and the type of refinery process that they undergone. Aromatics hydrocarbons, in particular benzene, toluene, ethylbenzene and isomeric xylenes (BTEX) are the toxic group constituents presents. GC-FID was employed to quantify these hydrocarbons in 50 commercial gasoline samples from Piauí state. Statistical analysis techniques, such as PCA and HCA were used to analyze the data. Moreover, several validation parameters were evaluated.

Slutrapport för projektet Varför försvann malarian från Svenskfinland?

Slutrapport

Recension: Catrin Norrby & Gisela Håkansson (2007), Språkinlärning och språkanvändning. Svenska som andraspråk i och utanför Sverige.

Recension.

Niveljalkaiset taistelutantereella

Kirjallisuusarvostelu

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.

Lidandet som kamp och drama

Denna studie syftar till att via utformandet av en teoretisk modell nå ökad förståelse för hur människan erfar lidandet. Studien, som har en hermeneutisk ansats, fokuserar lidandet som drama och kamp, vilka beskrivs som lidandets form och substans. Data insamlades genom samtal med informanter från två kontext. Den ena informantgruppen som utgjordes av nio personer med drogrelaterade problem valdes med utgångspunkt i ett antagande om att missbruket härrör från ett livslidande. De övriga informanterna (nio stycken) söktes inom ett till det yttre kontrasterande kontext, de hjärtopererade patienternas. De texter dessa samtal genererade tolkades sedan med utgångspunkt i en hermeneutisk ansats, som hämtat metodologisk inspiration av Ricoeur och Helenius. Tolkningen ägde rum i flera steg och det meningsbärande söktes genom naiv tolkning, analys av textens struktur samt genom ett sökande efter alternativa tolkningar. Tolkningsprocessen resulterade en uppsättning teser vilka relaterades till undersökningens teoretiska perspektiv samt till en begreppsanalys av ’kamp’. Den teoretiska modellen tar fasta på lidandets kamp som en kamp mellan värdighet och skam, lust och olust. Denna kamp kan gestaltas i lidandets drama där människan på olika sätt söker lindring i lidandet. Detta kan ske genom att man försöker besegra lidandet, avtäcka det eller försonas med det. Ytterligare ett sätt att söka lindring är att ge upp lidandets kamp och resignera. I den teoretiska modellen gestaltas även hur människan kan förhålla sig till kampen på olika sätt beroende på vilket perspektiv hon har inför framtiden. Då människan uppfattar att framtiden präglas av ett hot om avskurenhet och död förhåller hon sig till livet på ett sådant sätt att lidandet dominerar. Om uppfattningen om framtiden präglas av liv och gemenskap kan hon förhålla sig till kampen som hälsa. När lidandet blir outhärdligt förlorar människan sin förankring i tiden. I och med att människan isoleras i nuet kan lidandet bemästras och begränsas till en konkret situation. För att en rörelse i hälsoprocesserna skall äga rum måste människan emellertid relatera till tiden. Relationen till en annan människa och skapandet av en lidandeberättelse innebär en möjlighet till förankring i tiden och därmed också till helande.

Täällä pysytään hengissä luomalla lauluja. Arki ja suomalaisuus Johanna Venhon runoelmassa Yhtä juhlaa

Tutkielma on kulttuurintutkimuksellinen analyysi kansallisista merkityksistä Johanna Venhon (s.1971) runoelmassa Yhtä juhlaa (2006). Runoelman kansallisia aspekteja ei ole juuri huomioitu sen vastaanotossa. Haen tutkimuksessani vastausta siihen, miten Yhtä juhlaa esittää suomalaisuutta ja mihin se tarvitsee tässä esityksessä edeltäjiään kansallisessa traditiossa. Tutkimukseni nationalistisen teorian viitekehyksenä toimii Benedict Andersonin ajatus kansakuntien kuvitellusta luonteesta sekä Michael Billigin käsite arkinen nationalismi. Kulttuurintutkimuksellinen analyysi pitää sisällään kansallisten merkitysten sukupuolittumisen, kulttuuristen merkitysten rakentumisen lyyrisen perinteen ja kielen muodostamina kulttuurikoodauksina sekä ekologisen näkökulman. Suomalaisuuden esittäminen ilmenee ensinnäkin Yhtä juhlaa -runoelman viitekehyksenä toimivasta kansanrunon traditiosta, joka kulkee mukana 2000-luvun runominän arjessa. Runoelma esittää suomalaisuutta myös muina kulttuurikoodauksina sekä arkisina käytäntöinä. Yhtä juhlaa antaa äidille/naiselle aktiivisen toimijan roolin suomalaisuuden kuvastossa, joka näkyy esimerkiksi runojen minän arjesta selviytymisen keinoina, kieltäytymisenä vahvan naisen retoriikkaan liitetystä vaikenemisesta, ekologisena diskurssina ja lyyrisen hiihtokuvauksen uudistumisena. Tutkimuksessani hahmottuu arjen merkitys kansallisen kuvan muuttumiselle. Suomalaisuutta ei kuvata Yhtä juhlaa -runoelmassa ihaillen ja kaukaa juhlakäyttöön vaan suomalaisen äidin arjessa tehtyjen huomioiden pohjalta. Arjesta nähty kuva on retusoimaton esitys siitä, millaisia piirteitä suomalaisuuteen tänä päivänä liitetään. Yhtä juhlaa -runoelman voi nähdä jonkinlaisena muutoksen osoituksena, koska se tuo eksplisiittisesti kansallisen tradition uudelleen arvioitavaksi arjen kautta. Aiemmalle kuvastolle tyypillisen juhlavuuden poissaolo mahdollistaa jaetun kokemuksen, joka on toden tuntuisena kenties helpompi samastumiskohde tämän päivän suomalaiselle kuin kaukaa ja ihaillen toteutetut fantasiat siitä, mitä on olla suomalainen. Koska tutkimukseni koskee vain Yhtä juhlaa -runoelmaa, olisi esimerkiksi Venhon muun tuotannon tai muiden nykylyyrikoiden kansallisten piirteiden kartoittaminen tarpeellista laajempien kansallisten merkitysten analysoinnille.

Tecnologias de Informação e Comunicação: contribuições para o processo interdisciplinar no ensino superior

Esta pesquisa teve por objetivo analisar como as Tecnologias da Informação e da Comunicação são utilizadas como possibilidade pedagógica para criar um ambiente de aprendizado e que contribuições podem trazer para a interdisciplinaridade prevista nas atuais diretrizes curriculares nacionais do ensino médico. A análise de dados enfatizou os seguintes temas: o projeto político- pedagógico no âmbito das diretrizes curriculares do ensino médico; as tecnologias de Informação e Comunicação no enfoque interdisciplinar; seus entraves na práxis pedagógica. As reflexões preliminares apontaram para os seguintes aspectos: a importância do projeto político pedagógico como norteador dos objetivos do ensino; a integração interdisciplinar como um processo para a melhoria da qualidade do ensino; as TIC como um instrumento facilitador da aprendizagem; as dificuldades dos discentes frente à seleção de informações no ambiente virtual; e, finalmente, o desafio para a formação do médico generalista.

AN APOLOGY OF CARNAP

This paper is focused on dismissive metaontological views about ontology. The paper's first section deals with radical dismissivism: a view which I interpret as Carnap's (1956). The second section approaches moderate dismissivism: a view which I interpret as Hirsch's (2011). My first claim is stated in section three: that there are significant differences between the mentioned authors. However, current literature on metaontology, not only does not emphasize such differences, but also insinuates that they do not exist. The authors I have in mind here are Eklund (2007, 2009) and Bennett (2009). In the fourth section, I compare Carnap's radical dismissivism with Hirsch's moderate dismissivism. My second claim is stated in section five: that Carnap's radical dismissivism is more persuasive than Hirsch's moderate one.

Potencial poluidor de resíduo sólido da Samarco Mineração: estudo de caso da barragem de Germano

Foram estudadas amostras de resíduo sólido da Barragem de Germano, da Samarco Mineração S.A. Tal barragem localiza-se no município de Mariana-MG. Sua principal função é coletar os efluentes do tratamento do minério de ferro processado no Complexo de Germano. Este resíduo foi submetido a testes de classificação, de acordo com as Normas ABNT 10004, 10005, 10006 e 10007. Constatou-se que o resíduo é classe III (inerte) e que os testes mostraram a grande capacidade deste material na retenção de metais pesados e de cromo.