Antiparasitic bromotyrosine derivatives from the Caribbean marine sponge Aiolochroia crassa

Six bromotyrosine-derived compounds were isolated from the Caribbean marine sponge Aiolochroia crassa: 3-bromo-5-hydroxy-O-methyltyrosine (1), 3-bromo-N,N,N-trimethyltyrosinium (2), 3-bromo-N,N,N,O-tetramethyltyrosinium (3), 3,5-dibromo-N,N,N-trimethyltyrosinium (4), 3,5-dibromo-N,N,N,O-tetramethyltyrosinium (5), and aeroplysinin-1 (6). Structural determination was performed using NMR, MS and comparison with literature data. All isolated compounds were screened for their in vitro activity against Leishmania panamensis, Plasmodium falciparum and Trypanosoma cruzi. Compound 4 showed selective antiparasitic activity against Leishmania and Plasmodium parasites. This is the first report of compounds 1, 4 and 5 in the sponge A. crassa and the first biological activity reports for compounds 2-4. This work shows that bromotyrosines are potential antiparasitic agents.

Produção de biossurfactantes por microrganismos isolados de solo contaminado com óleo diesel

The aim of this work was to produce biosurfactants through submerged fermentation using microorganisms isolated from soil contaminated with diesel. Microorganisms were isolated, characterized by the production of biosurfactants, and used to study the influence of type, induction and concentration of ammonium sulfate as a nitrogen source in the culture medium. The microorganisms that showed best results, in terms of production of biosurfactants, were identified as being of the genus Pseudomonas and Bacillus. The biosurfactants produced proved capable of reducing the surface tension of the media to 39 mN/m and 34 mN/m, respectively. Higher biosurfactant production was obtained in the medium containing 1% soybean oil without ammonium sulfate.

Biomolecules produced in liquid-state fermentation by a marine-derived fungus, Penicillium roqueforti

Screening of biomass of a new marine-derived strain of Penicillium roqueforti, as produced by liquid-state fermentation, led to the identification of several volatile organic compounds active in the fatty acid pathway as well as fragments produced by their catabolism, terpenoids, and metabolites from the shikimic acid pathway. In addition, five non-volatile organic compounds, triolein, ergosterol peroxide, 9(11)-dehydroergosterol peroxide, 4-hydroxybenzaldehyde, and d-mannitol, were isolated and identified by spectroscopy. The results showed that this fungal strain did not produce any mycotoxin in the culture conditions applied, and thus is useful for industrial applications, where high value-added biomolecules are generated.

Análise exploratória aplicada a espectros de reflexão total atenuada no infravermelho com transformada de Fourier (ATR-FTIR) de blendas de biodiesel/diesel

In this study, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to classify blends produced from diesel S500 and different kinds of biodiesel produced by the TDSP methodology. The different kinds of biodiesel studied in this work were produced from three raw materials: soybean oil, waste cooking oil and hydrogenated vegetable oil. Methylic and ethylic routes were employed for the production of biodiesel. HCA and PCA were performed on the data from attenuated total reflectance Fourier transform infrared spectroscopy, showing the separation of the blends into groups according to biodiesel content present in the blends and to the kind of biodiesel used to form the mixtures.

DETERMINAÇÃO DO TEOR DE BIODIESEL EM DIESEL EMPREGANDO O ENSAIO COLORIMÉTRICO DO ÁCIDO HIDROXÂMICO

The aim of this paper was to use colorimetric assays for hydroxamic acid to quantify the biodiesel content in diesel and compare it with the traditional method (infrared spectroscopy, using the EN 14078 method). Samples were prepared from B2 to B10 with two kinds of diesel - S500 (red) and S50 (yellow) - to obtain two calibration curves. Through statistical methods it was shown that the slopes of the straight lines obtained for the different types of diesel were the same. Thus, the type of diesel did not influence the results of the colorimetric assay for hydroxamic acid. Real samples collected from gas stations were analyzed by both methods (colorimetry and EN 14078). By applying Student's t-test it was concluded that the methods could be considered statistically equivalent. Therefore, it was confirmed that the colorimetric assay for hydroxamic acid is suitable for detecting and quantifying the content of biodiesel in biodiesel/diesel blends and can also be easily adapted to field analyses.

DESENVOLVIMENTO DE ENSAIO PARA ANÁLISE QUALITATIVA DE BIODIESEL EM MISTURAS DIESEL-BIODIESEL PARA APLICAÇÃO EM POSTOS REVENDEDORES DE COMBUSTÍVEIS

In this study, we developed a method for the visual detection of biodiesel in petrodiesel-biodiesel (BX) blends through the aminolysis of the methyl or ethyl esters of fatty acids that are found in biodiesel and that are absent from diesel and vegetable oils. This method is based on three reactional stages, which produce a dark red and easily visualized complex in the presence of biodiesel. In the absence of biodiesel, there is no dark red coloring, whereas in the presence of diesel or vegetable oil, there is a light red to yellow coloring. This simple, practical, inexpensive, and effective procedure may be applied by petrol stations to guarantee to consumers and resellers the presence of biodiesel in diesel blends, regardless of the BX blend's initial coloring or of the sulfur found in the diesel. In short, it ensures a safe fuel tank fill-up with BX blend.

Applications and Markets of Linear Motors

A steady increase in practical industrial applications has secured a place for linear motors. They provide high dynamics and high positioning accuracy of the motor, high reliability and durability of all components of the system. Machines with linear motors have very big perspectives in modern industry. This thesis enables to understand what a linear motor is, where they are used and what situation there is on their market nowadays. It can help to understand reasonability of applying linear motors on manufacture and benefits of its application.

Determination of sulfur in diesel using ATR/FTIR and multivariate calibration

The aim of this present work was to provide a more fast, simple and less expensive to analyze sulfur content in diesel samples than by the standard methods currently used. Thus, samples of diesel fuel with sulfur concentrations varying from 400 and 2500 mgkg-1 were analyzed by two methodologies: X-ray fluorescence, according to ASTM D4294 and by Fourier transform infrared spectrometry (FTIR). The spectral data obtained from FTIR were used to build multivariate calibration models by partial least squares (PLS). Four models were built in three different ways: 1) a model using the full spectra (665 to 4000 cm-1), 2) two models using some specific spectrum regions and 3) a model with variable selected by classic method of variable selection stepwise. The model obtained by variable selection stepwise and the model built with region spectra between 665 and 856 cm-1 and 1145 and 2717 cm-1 showed better results in the determination of sulfur content.

Dieselmoottorin analogisen kierrosnopeusmittauksen digitalisointi

Työssä suunnitellaan kierrosnopeusmittauksen toteutus vanhaan Ford -teollisuusdieseliin käyttäen moottorin alkuperäistä kierrosnopeusanturia. Anturi kunnostetaan vaihtamalla vanha, palanut käämi uuteen digitaaliseen järjestelmään soveltuvaan käämiin. Sen toimin-ta halutulla kierrosnopeusalueella varmistetaan mittauksin ja tämän perusteella suunnitel-laan kytkentä sen liittämiseksi kierrosnopeuden laskevaan mikrokontrolleriin. Kytkennän toimivuutta testataan simuloimalla ennen prototyypin rakentamista. Erilaisia vaihtoehtoja analogisen näytön toteuttamiseksi tutkitaan ja niistä valitaan yksi ve-nekäyttöön soveltuva, joka toteutetaan järjestelmän näyttöratkaisuksi. Järjestelmälle suunnitellaan piirilevy, jolle prototyyppi kasataan. Mikrokontrollerille koodataan C -ohjelmointikielellä ohjelma, joka laskee dieselmoottorin kierrosnopeuden anturipulssien perusteella ja ohjaa näyttöä.

Field Weakening, Parameters and Operation Range of the Permanent Magnet Traction Motors

The main focus of this thesis is to define the field weakening point of permanent magnet synchronous machine with embedded magnets in traction applications. Along with the thesis a modelling program is made to help the designer to define the field weakening point in practical applications. The thesis utilizes the equations based on the current angle. These equations can be derived from the vector diagram of permanent magnet synchronous machine. The design parameters of the machine are: The maximum rotational speed, saliency ratio, maximum induced voltage and characteristic current. The main result of the thesis is finding out the rated rotational speed, from which the field weakening starts. The action of the machine is estimated at a wide speed range and the changes of machine parameters are examined.

Dieselmoottorisen kaupunkilinja-auton muuttaminen sarjahybridiajoneuvoksi

Tutkimus on pohjustusta Lappeenrannan teknillisen yliopiston Green Campus–hankkeessa tulevaisuudessa mahdollisesti rakennettavalle Cambus–hybridibussille ja siihen liittyvälle muutostyölle. Tässä tutkimuksessa käsitellään asioita, joita kohdataan kun tavallinen dieselkäyttöinen linja–auto muutetaan hybridiajoneuvoksi. Työ sisältää teoriaosuuden, jossa esitellään peruskomponentteja esimerkiksi moottoreiden ja energianvarastointitekniikoiden osalta sekä uusimpia kehityskohteita polttomoottoreiden osalta. Tutkimuksessa on myös vertailtu erilaisia hybridivaihtoehtoja sekä käsitelty mm. tasauspyörästön välityssuhteen ja vaihteiston vaikutusta bussin teoreettiseen suorituskykyyn. Tehdyn tutkimustyön perusteella on hahmoteltu eräs mahdollinen sarjahybridibussin voimansiirtolinja esimerkkikomponentteineen. Tutkimuksessa esitetään myös laskelmia järjestelmän teoreettisesta polttoaineenkulutuksesta jarrutusenergian talteenotto huomioiden perinteiseen kaupunkilinja-autoon verrattuna.

Comportamento de um motor de ignição por compressão trabalhando com óleo Diesel e gás natural

A previsível escassez de petróleo aliada a uma consciência ecológica está levando pesquisadores a procurar novas fontes de energia e processos de combustão mais eficientes e menos poluentes. Entre os combustíveis menos poluentes está o gás natural, cujo consumo aumenta ano a ano. Os motores de combustão interna são transformadores de energia que têm baixa eficiência de conversão. Este trabalho avaliou um motor Diesel, bicombustível, movido a Diesel e gás natural. Nesse motor, a energia provém, basicamente, da combustão do gás natural. O Diesel tem a função de produzir o início da combustão do gás, que é o combustível principal. Assim, haverá uma substituição parcial de óleo Diesel por gás natural, aumentando o rendimento da combustão. Inicialmente, foi feito um ensaio-testemunha, somente com óleo Diesel e após foram feitos ensaios, com três repetições, para variadas proporções de óleo Diesel, gás natural e ângulos de avanço da injeção. O melhor desempenho foi obtido para 22% de óleo Diesel em relação ao máximo débito da bomba injetora e 13 L min-1 de gás natural com ângulo de avanço de injeção original (21º). Nesse caso, a potência média aumentou 14%, e o consumo específico (medido em valores monetários) diminuiu 46% em relação ao ensaio-testemunha.

Desempenho de motor ciclo Diesel em bancada dinamométrica utilizando misturas diesel/biodiesel

Diante da previsão de escassez do petróleo, o éster etílico (biodiesel) tem-se apresentado como excelente opção de combustível alternativo para motores ciclo Diesel. As características do biodiesel são semelhantes às do diesel em termos de viscosidade e poder calorífico, podendo ser utilizado sem adaptações nos motores. Para a realização deste trabalho, utilizou-se de motor ciclo Diesel, de injeção direta, com quatro cilindros, sem adaptações. O motor foi acoplado a um dinamômetro e sistemas de aquisição de dados auxiliares. Avaliaram-se os desempenhos de torque, de potência e de consumo específico de combustível para as seguintes misturas diesel/éster etílico de soja: B2, B5, B10, B20, B50, B75 e B100. O melhor desempenho registrado deu-se com a mistura B20.

Biodiesel de mamona no diesel interior e metropolitano em trator agrícola

A demanda de recursos energéticos pelos sistemas de produção, aliada à escassez dos combustíveis fósseis, tem motivado a produção do Biodiesel, que é um combustível obtido de fontes renováveis. O objetivo deste trabalho foi realizar dois ensaios: o primeiro dinâmico, para avaliar o desempenho operacional utilizando como parâmetro o consumo de combustível, e o segundo, estático, para mensurar a opacidade da fumaça (material particulado) do motor de um trator agrícola, operando com diesel metropolitano e interior misturados ao Biodiesel de mamona, em sete proporções. O trabalho foi conduzido no Departamento de Engenharia Rural da UNESP/Jaboticabal - SP. Os resultados mostraram que o tipo de diesel influenciou no consumo de combustível e na opacidade da fumaça, sendo o diesel metropolitano de melhor qualidade; observou-se, também, que à medida que a proporção de Biodiesel aumentou, o mesmo ocorreu para o consumo de combustível; entretanto, a opacidade da fumaça reduziu com o acréscimo de Biodiesel até B75.