The application of calcined natural dolomitic rock as a solid base catalyst in triglyceride transesterification for biodiesel synthesis

Natural dolomitic rock has been investigated in the transesterification of C and C triglycerides and olive oil with a view to determining its viability as a solid base catalyst for use in biodiesel synthesis. XRD reveals that the dolomitic rock comprised 77% dolomite and 23% magnesian calcite. The generation of basic sites requires calcination at 900 °C, which increases the surface area and transforms the mineral into MgO nanocrystallites dispersed over CaO particles. Calcined dolomitic rock exhibits high activity towards the liquid phase transesterification of glyceryl tributyrate and trioctanoate, and even olive oil, with methanol for biodiesel production. © The Royal Society of Chemistry 2008.

Hierarchical nanoporous solid base catalysts for biofuels

Novel macroporous solid bases have been developed as alternative clean technologies to existing commercial homogeneous catalysts for the production of biodiesel from triglycerides; the latter suffer process disadvantages including complex separation and associated saponification and engine corrosion, and are unsuitable for continuous operation. To this end, tuneable macroporous MgAl hydrotalcites have been prepared by an alkali-free route and characterised by TGA, XRD, SEM and XPS. The macropore architecture improves diffusion of bulky triglyceride molecules to the active base sites, increasing activity. Lamellar and macroporous hydrotalcites will be compared for the transesterification of both model and plant oil feedstocks, and structure-reactivity relations identified.

New solid base catalysts for biodiesel synthesis

The application of heterogeneous catalysts for the manufacture of renewable biodiesel fuels offers an exciting, alternative clean chemical technology to current energy intensive processes employing soluble base catalysts. We recently synthesised tuneable MgO nanocrystals as efficent solid base catalysts for biodiesel synthesis, and have developed a simple X-ray spectroscopic method to quantitatively determine surface basicity, thereby providing a rapid screening tool for predicting the reactivity of new solid base catalysts. Promotion of these MgO nanocrystals through Cs doping dramatically enhances biodiesel production rates due to the formaion of a mixed Cs Mg(CO ) phase. These MgO derived nanocatalysts permit energy efficent, continuous processing of diverse, sustainable oil feedstocks in flow reactors.

Solid base catalysed 5-HMF oxidation to 2,5-FDCA over Au/hydrotalcites:fact or fiction?

Nanoparticulate gold has emerged as a promising catalyst for diverse mild and efficient selective aerobic oxidations. However, the mechanism of such atom-economical transformations, and synergy with functional supports, remains poorly understood. Alkali-free Mg-Al hydrotalcites are excellent solid base catalysts for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furan dicarboxylic acid (FDCA), but only in concert with high concentrations of metallic gold nanoparticles. In the absence of soluble base, competitive adsorption between strongly-bound HMF and reactively-formed oxidation intermediates site-blocks gold. Aqueous NaOH dramatically promotes solution phase HMF activation, liberating free gold sites able to activate the alcohol function within the metastable 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) reactive intermediate. Synergistic effects between moderate strength base sites within alkali-free hydrotalcites and high gold surface concentrations can afford highly selective and entirely heterogeneous catalysts for aqueous phase aldehyde and alcohol cascade oxidations pertinent to biomass transformation.

New solid bases for biodiesel synthesis

Biodiesel is a promising non-toxic and biodegradable renewable fuel, synthesized by the homogeneous base-catalyzed transesterification of vegetable oils or animal fats with methanol or ethanol. Removal of the base, typically Na or K alkoxide, after reaction is a major problem since aqueous quenching results in stable emulsions and saponification. The use of a solid base catalyst offers several process advantages including the elimination of a quenching step (and associated basic water waste) to isolate the products, and the opportunity to operate in a continuous process. The synthesis and characterization of a series of Li-doped CaO and Mg-Al hydrotalcite solid base catalysts were presented and their physicochemical properties were correlated with their activity in biodiesel synthesis. Both catalysts were effective solid bases for the transesterification of triglycerides to the methyl ester, with catalyst activity related to the electronic properties of Li and Mg dopants. This is an abstract of a paper presented at the 230th ACS National Meeting (Washington, DC 8/28/2005-9/1/2005).

Estimating Amino Acid Requirement of Brazilian Freshwater Fish from Muscle Amino Acid Profile

Information on nutritional requirement of some Brazilian farmed fish species, especially essential amino acids (EAA) requirements, is scarce. The estimation of amino acids requirements based on amino acid composition of fish is a fast and reliable alternative. Matrinxa, Brycon amazonicus, and curimbata, Prochilodus lineatus, are two important Brazilian fish with potential for aquaculture. The objective of the present study was to estimate amino acid requirements of these species and analyze similarities among amino acid composition of different fish species by cluster analysis. To estimate amino acid requirement, the following formula was used: amino acid requirement = [(amount of an individual amino acid in fish muscle tissue) x (average totalEAA requirement among channel catfish, Ictalurus punctatus, Nile tilapia, Oreochromis niloticus, and common carp, Cyprinus carpio)]/(average fish muscle totalEAA). Most values found lie within the range of requirements determined for other omnivorous fish species, in exception of leucine requirement estimated for both species, and arginine requirement estimated for matrinxa alone. Rather than writing off the need for regular dose-response assays under the ideal protein concept to determine EAA requirements of curimbata and matrinxa, results set solid base for the study of tropical species dietary amino acids requirements.

Biodiesel production from waste frying oils over lime catalysts

Biodiesel production from semi-refined oils (SRO) and waste frying oils (WFO) was studied using commercial CaO as heterogeneous catalyst. The methanolysis tests were carried out in mild reaction conditions (62 A degrees C, atmospheric pressure). With such conditions, SRO (soybean and rapeseed) allowed to produce a biodiesel containing 97-98 % of methyl esters (FAME), whereas WFO only provided 86-87 % of FAME. The lower FAME yield for WFO oil is ascribable to the partial neutralization of the catalyst by free fatty acids. Also, soaps formation from the WFO oil reduced the weight yield of the oil phase (containing FAME) obtained and increased the MONG content of the glycerin phase. The catalysts stability tests showed high stability even when WFO oil was processed. Catalytic tests performed with blends of WFO/semi-refined oils showed blending as a good strategy to process low value raw oils with minor decay of the catalyst performance. Both WFO and semi-refined oils showed S-shape kinetics curves thus discarding significant differences of the reaction mechanisms.

Fragmentos de um adeus: fado, tango e música popular brasileira em cena

Trabalho de Projecto submetido à Escola Superior de Teatro e Cinema para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Artes Performativas - especialização em Teatro-Música.

Web competitive intelligence methodology

Master’s Degree Dissertation

Adaptive Game Design Study of a fully adaptive framework

Adventure! The Paladin Order foi um projecto ambicioso que começou por ser desenvolvido como um video jogo completo. Tinha como objéctivo implementar uma ferramenta diferente que permitisse tornar o jogo completamente adaptativo às decisões do jogador tanto nas interacções e no diálogo com outras personagens, assim como no combate contra os variados inímigos do jogo. Devido à inexperiência do autor uma grande parte do tempo foi passado a estudar e a pesquisar várias possíveis soluções que permitissem criar um ambiente que fosse adaptativo de uma forma simples e interessante, não só para os programadores mas também para qualquer pessoa que fosse responsável por editar o diálogo e a história do jogo. Os resultados foram bastante interessantes, revelando um sistema que depende simultaneamente dos ficheiros de onde é retirado o diálogo, e de um sistema de personalidades que permite definir qual será o comportamento de qualquer objecto do jogo ou, pelo menos, como as outras personagens irão reagir. O produto final é uma ferramenta de bases sólidas que permite uma implementação relativamente simples de um sistema abrangente e adaptativo, com poucas falhas e apenas algumas questões de simplicidade de código.

What makes a good team? : Following the example of sport teams

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Talent, expert o les dues coses

De vegades és difícil distingir els conceptes d’individu amb talent i individu expert. Sens dubte, això és degut a que els individus que assoleixen l’èxit en l’esport, la música, el teatre, la literatura, etc. mostren ambdues condicions: una si es vol innata, el talent, i una altra adquirida, la de ser expert. També, de vegades, desitjaríem que els talents treballessin per a ser experts, aspecte que els elevaria a un grau superior d’excel·lència. En el present article es realitza una posada al dia d’ambdós conceptes amb l’objectiu d’establir una base adequada sobre la que sostenir amb més solidesa les decisions i actuacions del formador. També es presenten algunes nocions sobre el seguiment i control dels nois que gaudeixen en les canteres esportives sempre amb l’orientació bàsica de formar individus complerts amb un rendiment òptim.

Aplicação e modificação química da sílica gel obtida de areia

The silica gel was obtained from sand and its surface was modified with POCl3 to produce Si-Cl bonds on the silica surface. Ethylenediamine was covalently bonded onto the chlorinated silica surface. The adsorption of the chlorides of divalent cobalt, nickel and copper was qualitatively studied to show that the bonding of ethylenediamine onto the silica gel surface produces a solid base capable of chelating metal ions from solution. The experiments illustrate the extraction of silica gel, its reactivity, the development of modified surfaces and its application in removing metal ions from water and are deigned for undergraduate inorganic chemistry laboratories.

Saako historiasta selvää? Monikulttuuriset yläkoululaiset historian lähteillä historian taidot motiivien, seurauksien, historian tulkintojen ja lähteiden luotettavuuden arvioinneissa

The research assesses the skills of upper comprehensive school pupils in history. The focus is on locating personal motives, assessing wider reasons hidden in historical sources and evaluating source reliability. The research also questions how a wide use of multiple sources affects pupils’ holistic understanding of historical phenomena. The participants were a multicultural group of pupils. The origins of their cultures can be traced to the Balkan, the Middle East, Asia and Europe. The number of native Finnish speakers and pupils speaking Finnish as their second language was almost equal. The multicultural composition provides opportunities to assess how culturally responsive learning history from sources is. The intercultural approach to learning in a multicultural setting emphasizes equality as a precondition for learning. In order to set assignments at least to some extent match with all participants only those answers were taken into account which were produced by pupils who had studied history for a similar period of time in the Finnish comprehensive school system. Due to the small number of participants (41), the study avoids wide generalizations. Nevertheless, possible cultural blueprints in pupils’ way of thinking are noted. The first test examined the skills of pupils to find motives for emigration. The results showed that for 7th graders finding reasons is not a problematic task. However, the number of reasons noticed and justifications varied. In addition, the way the pupils explained their choices was a distinguishing factor. Some pupils interpreted source material making use of previous knowledge on the issue, while other pupils based their analysis solely on the text handed and did not try to add their own knowledge. Answers were divided into three categories: historical, explanatory and stating. Historical answers combined smoothly previously learned historical knowledge to one’s own source analysis; explanatory answers often ignored a wider frame, although they were effective when explaining e.g. historical concepts. The stating answers only noticed motives from the sources and made no attempts to explain them historically. Was the first test culturally responsive? All pupils representing different cultures tackled the first source exam successfully, but there were some signs of how historical concepts are understood in a slightly different way if the pupil’s personal history has no linkage to the concepts under scrutiny. The second test focused on the history of Native Americans. The test first required pupils to recognize whether short source extracts (5) were written by Indians or Caucasians. Based on what they had already learned from North American history, the pupils did not find it hard to distinguish between the sources. The analysis of multiphase causes and consequences of the disputes between Native Americans and white Americans caused dispersion among pupils. Using two historical sources and combining historical knowledge from both of them simultaneously was cumbersome for many. The explanations of consequences can be divided into two groups: the ones emphasizing short term consequences and those placing emphasis on long term consequences. The short term approach was mainly followed by boys in every group. The girls mainly paid attention to long term consequences. The result suggests that historical knowledge in sources is at least to some extent read through role and gender lenses. The third test required pupils to explain in their own words how the three sources given differed in their account of living conditions in Nazi Germany, which turned out to be demanding for many pupils. The pupils’ stronghold was rather the assessment of source reliability and accounts why the sources approached the same events differently. All participants wrote critical and justified comments on reliability and aspects that might have affected the content of the sources. The pupils felt that the main reasons that affected source reliability were the authors’ ethnic background, nationality and profession. The assessment showed that pupils were well aware that position in a historical situation has an impact on historical accounts, but in certain cases the victim’s account was seen as a historical truth. The account of events by a historian was chosen most often as the most reliable source, but it was often justified leniently with an indication to professionalism rather than with clear ideas of how historians conduct accounts based on sources. In brief, the last source test demonstrates that pupils have a strong idea that the ethnicity or nationalism determines how people explained events of the past. It is also an implication that pupils understand how historical knowledge is interpretative. The results also imply that history can be analyzed from a neutral perspective. One’s own membership in an ethnical or religious group does not automatically mean that a person’s cultural identity excludes historical explanations if something in them contradicts with his or her identity. The second method of extracting knowledge of pupils’ historical thinking was an essay analysis. The analysis shows that an analytical account of complicated political issues, which often include a great number of complicated political concepts, leads more likely to an inconsistent structure in the written work of pupils. The material also demonstrates that pupils have a strong tendency to take a critical stance when assessing history. Historical empathy in particular is shown if history somehow has a linkage to young people, children or minorities. Some topics can also awake strong feelings, especially among pupils with emigrant background, if there is a linkage between one’s own personal history and that of the school; and occasionally a student’s historical experience or thoughts replaced school history. Using sources during history lessons at school seems to have many advantages. It enhances the reasoning skills of pupils and their skills to assess the nature of historical knowledge. Thus one of the main aims and a great benefit of source work is to encourage pupils to express their own ideas and opinions. To conclude, when assessing the skills of adolescents in history - their work with sources, comments on history, historical knowledge and finally their historical thinking - one should be cautious and avoid cut off score evaluations. One purpose of pursuing history with sources is to encourage pupils to think independently, which is a useful tool for further identity construction. The idea that pupils have the right to conduct their own interpretations of history can be partially understood as part of a wider learning process, justification to study history comes from extrinsic reasons. The intrinsic reason is history itself; in order to understand history one should have a basic understanding of history as a specific domain of knowledge. Using sources does not mean that knowing history is of secondary importance. Only a balance between knowing the contextual history, understanding basic key concepts and working with sources is a solid base to improve pupils’ historical understanding.

Improvement of Surface Strength of Paper

Offset printing is a popular printing method that is especially suitable for large and fast print jobs. Newspapers, magazines and books are typical examples of products printed with offset method. In high volume printing production high efficiency is essential. Offset printing uses tacky inks that cause serious stress to the paper surface. Dusting and linting are terms that describe how loose and weakly bonded particles are removed from the paper surface in the printing process. The removed particles accumulate in the process causing deteriorating print quality. This forces the printing operators to stop production for washing and cleaning. Time and money are lost. Dusting and linting tendency of paper can be decreased by improving the surface strength of paper. In the present work a method to increase the surface strength of paper was studied. In the literature part offset printing method and challenges related to offset printing are presented. A review of new methods for surface sizing of paper is also presented. The experimental part presents trials where an apparatus for improving paper surface strength was tested and developed in mill scale. Laboratory work supporting the actual mill scale operations is also presented. The acquired results provide a solid base of information to make decisions on how to proceed with research in the present field of study.