Agonistic-like responses from the torus semicircularis dorsalis elicited by GABA A blockade in the weakly electric fish Gymnotus carapo

Findings by our group have shown that the dorsolateral telencephalon of Gymnotus carapo sends efferents to the mesencephalic torus semicircularis dorsalis (TSd) and that presumably this connection is involved in the changes in electric organ discharge (EOD) and in skeletomotor responses observed following microinjections of GABA A antagonist bicuculline into this telencephalic region. Other studies have implicated the TSd or its mammalian homologue, the inferior colliculus, in defensive responses. In the present study, we explore the possible involvement of the TSd and of the GABA-ergic system in the modulation of the electric and skeletomotor displays. For this purpose, different doses of bicuculline (0.98, 0.49, 0.245, and 0.015 mM) and muscimol (15.35 mM) were microinjected (0.1 µL) in the TSd of the awake G. carapo. Microinjection of bicuculline induced dose-dependent interruptions of EOD and increased skeletomotor activity resembling defense displays. The effects of the two highest doses showed maximum values at 5 min (4.3 ± 2.7 and 3.8 ± 2.0 Hz, P < 0.05) and persisted until 10 min (11 ± 5.7 and 8.7 ± 5.2 Hz, P < 0.05). Microinjections of muscimol were ineffective. During the interruptions of EOD, the novelty response (increased frequency in response to sensory novelties) induced by an electric stimulus delivered by a pair of electrodes placed in the water of the experimental cuvette was reduced or abolished. These data suggest that the GABA-ergic mechanisms of the TSd inhibit the neural substrate of the defense reaction at this midbrain level.

Photocatalysis Studies under Visible Light Irradiation with TiO2 Obtained by Pulsed Electric Field Assisted Sol-Gel Method

The objective of this thesis was to study the effect of pulsed electric field on the preparation of TiO2 nanoparticles via sol-gel method under the visible light irradiation. The literature part introduces properties of different TiO2 crystal forms and principle of photocatalysis. It was expected that pulsed electric field would have an influence on degradation for oxalic acid and formic acid. TiO2 samples were prepared by using three frequencies (50Hz, 294Hz, and 963Hz) and two treatment times (12 minutes and 24 minutes) of pulsed electric field. The photocatalytic activities of TiO2 samples produced with sol-gel method were also compared with the TiO2 particles made by previous study and with the commercial TiO2 powder Aeroxide® (Evonic Degussa GmbH) at the same condition. Results show that pulsed electric field does have an effect on degradation for oxalic acid and formic acid. Generally, higher photocatalytic activities for oxalic acid and formic acid were obtained with lower frequency and longer treatment time of pulsed electric field.

Parâmetros de estrusão para produção de "snacks" de farinha de cará (Dioscorea alata)

Farinha de cará (Dioscorea alata) foi processada em extrusor mono-rosca, para a manufatura de "snacks". Foi empregada a Metodologia de Superfície de Resposta para avaliar os efeitos da umidade (16, 20 e 24%), temperatura (120, 150 e 180ºC) e diâmetro da matriz (3, 4 e 5mm) nas características dos extrusados. A temperatura foi a variável mais importante, influenciando todas as propriedades estudadas. O volume específico e o comprimento específico aumentaram quando a temperatura aumentou e a umidade e o diâmetro da matriz diminuíram, enquanto, ao mesmo tempo, fraturabilidade e dureza diminuíram. A expansão diminuiu, quando a temperatura aumentou de 120 para 180ºC. Foram selecionadas duas condições experimentais que possibilitavam obter "snacks" com propriedades desejáveis (alto volume específico e baixa dureza e fraturabilidade) e os produtos foram avaliados por equipes sensoriais não treinadas. Estas apontaram que o melhor produto foi aquele extrusado com um teor de umidade de 17%, a 170ºC, com uma matriz de 4mm de abertura. Este produto obteve um índice de aceitabilidade de 80%, quando avaliado por 140 consumidores.

Electric paralyzation and reduction of weight loss in the processing of round-cooked spiny lobsters

This study proposes alternatives to the current methods of processing round-cooked lobster. The paralyzation of lobsters with direct electric shock consumes 10.526 x 10-3 kWh, which is significantly less than the 11 kWh required by the traditional thermal-shock method (based on 60 kg of lobsters). A better weight gain was obtained by immersion of paralyzed lobsters in brine before cooking. Systematic trials combining 3, 6, or 9% brine concentrations with immersion periods of 15, 30, or 45 minutes were performed in order to determine the best combinations. A mathematical model was designed to predict the weight gain of lobsters of different sizes in any combination of treatments. For small lobsters, a 45 minutes immersion in 6% brine gave the best response in terms of weight gain (4.7%) and cooking produced a weight loss of only 1.34% in relation to fresh lobster weight. For medium-sized lobsters, a 45 minutes immersion in 9% brine produced a weight gain of 2.64%, and cooking a weight gain of 1.08%. For large lobsters, a 45 minutes immersion in 6% brine produced a weight gain of 3.87%, and cooking a weight gain of 1.62%.

Impacts of increased levels of wind penetration on the Electric Power System of the Åland Islands

The application of VSC-HVDC technology throughout the world has turned out to be an efficient solution regarding a large share of wind power in different power systems. This technology enhances the overall reliability of the grid by utilization of the active and reactive power control schemes which allows to maintain frequency and voltage on busbars of the end-consumers at the required level stated by the network operator. This master’s thesis is focused on the existing and planned wind farms as well as electric power system of the Åland Islands. The goal is to analyze the wind conditions of the islands and appropriately predict a possible production of the existing and planned wind farms with a help of WAsP software program. Further, to investigate the influence of increased wind power it is necessary to develop a simulation model of the electric grid and VSC-HVDC system in PSCAD and examine grid response to different wind power production cases with respect to the grid code requirements and ensure the stability of the power system.

Uncertainty of Efficiency Measurements in Electric Drives

The two central goals of this master's thesis are to serve as a guidebook on the determination of uncertainty in efficiency measurements and to investigate sources of uncertainty in efficiency measurements in the field of electric drives by a literature review, mathematical modeling and experimental means. The influence of individual sources of uncertainty on the total instrumental uncertainty is investigated with the help of mathematical models derived for a balance and a direct air cooled calorimeter. The losses of a frequency converter and an induction motor are measured with the input-output method and a balance calorimeter at 50 and 100 % loads. A software linking features of Matlab and Excel is created to process measurement data, calculate uncertainties and to calculate and visualize results. The uncertainties are combined with both the worst case and the realistic perturbation method and distributions of uncertainty by source are shown based on experimental results. A comparison of the calculated uncertainties suggests that the balance calorimeter determines losses more accurately than the input-output method with a relative RPM uncertainty of 1.46 % compared to 3.78 - 12.74 % respectively with 95 % level of confidence at the 93 % induction motor efficiency or higher. As some principles in uncertainty analysis are open to interpretation the views and decisions of the analyst can have noticeable influence on the uncertainty in the measurement result.

Sähköautojen akkuteknologioiden tilannekatsaus

Tämän kandidaatintyön tavoitteena oli tutkia sähköautoissa käytettäviä akkuteknologioita ja verrata niiden ominaisuuksia keskenään sekä sähköautojen asettamien akkuvaatimusten kanssa. Akkuteknologiakartoituksen ja ominaisuusvertailun avulla tutkimuksessa oli tarkoitus selvittää sähköautojen akkujen kehitystä menneestä nykyhetkeen ja luoda katsaus akkuteknologian tulevaisuuteen. Tutkimuksessa painotettiin akkujen suorituskykynäkökulmaa, mutta tutkimuksessa otettiin kantaa myös eri akkuteknologioiden turvallisuuteen, ympäristötekijöihin ja hintaan. Työ toteutettiin kirjallisuustutkimuksena ja lähteinä käytettiin alan kirjallisuutta, IEEE artikkeleita, tutkimusraportteja ja verkkodokumentteja. Lisäksi tutkimuksessa hyödynnettiin akku- ja sähköautovalmistajilta saatavaa tietoa, johon suhtauduttiin varauksin. Tutkimuksessa kävi ilmi, että erilaisia litiumioniakkuteknologioita käytetään tällä hetkellä eniten sekä täyssähköautoissa että pistokehybrideissä. Huomattiin, että akkujen suorituskyvyn kehittyminen on nopeutunut viime vuosina. Erityisesti akkujen energianvarastointikykyyn vaikuttavat ominaisenergiatasot ovat kasvaneet selkeästi. Nykyisen kehittyneen litiumioniakkuteknologian todettiin täyttävän jo osittain lähivuosien suorituskykytavoitteet. Tutkimuksessa tultiin siihen tulokseen, että litiumrikkiakkuteknologia voi korvata litiumioniakkuteknologian ainakin täyssähköautoissa parempien ominaisenergiatasojen ja halvempien valmistuskustannuksien takia. Myös litiumilma-akkuteknologialla havaittiin olevan mahdollisuuksia haastaa muut litiumakkuteknologiat seuraavalla vuosikymmenellä. Tutkimuksen johtopäätöksenä todetaan, että sähköautot voivat kaupallistua laajemmin lähivuosina akkujen suorituskykyominaisuuksien kehittyessä jatkuvasti. Suorituskykyominaisuuksien parantuminen tulee todennäköisesti johtamaan siihen, että täyssähköautot yleistyvät enemmän ja pistokehybridit tulevat jäämään sähköautojen välivaiheeksi. Uusien akkuteknologioiden käyttöönotto kaupallisiin sähköautoihin voi viedä kuitenkin odotettua kauemmin, sillä akut tarvitsevat huolellista testausta ja käyttöönotto edellyttää, että kaikki ominaisuudet ovat vaaditulla tasolla.

POLITICAL RISK IN FOREIGN DIRECT INVESTMENT IN THE RUSSIAN ELECTRIC POWER SECTOR

Russia approved ambitious reform plan for the electricity sector in 2001 including privatisation of the country’s huge thermal generation assets. So far the sector had suffered from power shortages, aging infrastructure, substantial electricity losses, and weak productivity and profitability numbers. There was obvious need for foreign investments and technologies. The reform was rather successful; the generation assets were privatised in auctions in 2007-2008 and three European energy companies, E.On, Enel and Fortum, invested in and obtained together over 10% of the Russian production assets. The novelty of these foreign investments serves unique object for the study. The political risk is involved in the FDI due to the industry’s social and economic importance. The research’s objective was to identify and analyse the political risk that foreign investors face in the Russian electricity sector. The research had qualitative study method and the empirical data was collected by interviewing. The research’s theoretical framework was based on the existing political risk theories and it focused to understand the Russian government in relation to the country’s stability and define both macro-level and micro-level sources of political risk for the foreign direct investments in the sector. The research concludes that the centralised and obscure political decision-making, economic constriction, high level of governmental control in economy and corruption form the country’s internal macro-level risk sources for the foreign investors in the sector. Additionally the retribution due to the companies’ home country actions, possible violent confrontations at the Russian borders and the currency instability are externally originated risk sources. In the electricity industry there is risk of tightened governmental control and increased regulation and taxation. Similarly the company-level risk sources link to the unreformed heating sector, bargaining with the authorities, diplomatic stress between host and home countries and to companies and government’s divergent perspective for the profit-making. The research stresses the foreign companies’ ability to cope with the characteristics of Russian political environment. In addition to frequent political and market risk assessment, the companies need to focus on currency protection against rouble’s rate fluctuation and actively build good company-citizenship in the country. Good relationship is needed with the Russian political authorities. The political risk identification and the research’s conclusive framework also enable political risk study assessments for other industries in Russia

Taxi side car, Central News, New York : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59415

1000 cm3, Dejon sur [side-car] Harley Davidson [critérium motocycliste de l'A.A.M.M., Association des anciens motocyclistes militaires à Auxerre, le 24 mai 1920] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59361

[Un side-car du critérium motocycliste de l'A.A.M.M., Association des anciens motocyclistes militaires à Auxerre, le 24 mai 1920] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59363

Auto-car Cook : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 60260

PRONOSTICATION || nouuelle Composee par troys ou || quatre. A Nantes sur vne escabelle || En lannee quon dit et appelle || Pour lan Mil cinq cens trente quatre. S. l. n. d. [Paris, 1533], in-8 de 8 f. non chifir. de 26 lignes à la page, car. goth., sign. A.

Daniel (Jehan), dit maistre Mîtou. Pronostication nouvelle (1533)