Efeito da variação do ph e da temperatura de síntese no desempenho de adesivos à base de creosoto vegetal desmetilado-formaldeído

O objetivo deste trabalho foi a produção de adesivos para madeira a partir de creosoto desmetilado. Para isto, foram sintetizadas diferentes formulações de adesivos para madeira a partir de creosoto desmetilado e paraformaldeído, variando-se o pH inicial da formulação (12,00, 12,25, 12,50, 12,75, 13,00, 13,25 e 13,50) e a temperatura de síntese (60 e 70 °C), para possibilitar a verificação dos melhores pHs e da melhor temperatura para elaboração do adesivo. Foi verificado, por meio da avaliação do gel time, que a melhor temperatura de síntese foi 70 °C. Foram realizadas, então, análises por DSC (calorimetria diferencial exploratória), para obtenção dos parâmetros cinéticos e caracterização das formulações adesivas de creosoto desmetilado sintetizadas a 70 °C. Os adesivos foram utilizados para colagem, a quente (160 °C) e sob pressão (12 kgf/cm²), de lâminas de Araucaria angustifolia. Após a colagem, foram realizados os ensaios de resistência mecânica ao cisalhamento por tração, para condição seca e úmida. Verificou-se que a resistência da linha de cola e a porcentagem de falha na madeira para os adesivos de creosoto desmetilado sintetizados a 70 °C foram inferiores às do adesivo de fenol-formaldeído sintetizado em laboratório, que foi utilizado como padrão.

Predicting Market Crashes: An Examination of the Performance of Macroeconomic Indicators and Technical Analysis

The purpose of this study is to examine macroeconomic indicators‟ and technical analysis‟ ability to signal market crashes. Indicators examined were Yield Spread, The Purchasing Managers Index and the Consumer Confidence Index. Technical Analysis indicators were moving average, Moving Average Convergence-Divergence and Relative Strength Index. We studied if commonly used macroeconomic indicators can be used as a warning system for a stock market crashes as well. The hypothesis is that the signals of recession can be used as signals of stock market crash and that way a basis for a hedging strategy. The data is collected from the U.S. markets from the years 1983-2010. Empirical studies show that macroeconomic indicators have been able to explain the future GDP development in the U.S. in research period and they were statistically significant. A hedging strategy that combined the signals of yield spread and Consumer Confidence Index gave most useful results as a basis of a hedging strategy in selected time period. It was able to outperform buy-and-hold strategy as well as all of the technical indicator based hedging strategies.

Astringent Food Compounds and Their Interactions with Taste Properties

Astringency is traditionally thought to be induced by plant tannins in foods. Because of this current research concerning the mechanism of astringency is focused on tannin‐protein interactions and thus on precipitation, which may be perceived by mechanoreceptors. However, astringency is elicited by a wide range of different phenolic compounds, as well as, some non‐phenolic compounds in various foods. Many ellagitannins or smaller compounds that contribute to astringent properties do not interact with salivary proteins and may be directly perceived through some receptors. Generally, the higher degree of polymerization of proanthocyanidins can be associated with more intense astringency. However, the astringent properties of smaller phenolic compounds may not be directly predicted from the structure of a compound, although glycosylation has a significant role. The astringency of organic acids may be directly linked to the perception of sourness, and this increases along with decreasing pH. Astringency can be divided into different sub‐qualities, including even other qualities than traditional mouth‐drying, puckering or roughing sensations. Astringency is often accompanied by bitter or sour or both taste properties. The different sub‐qualities can be influenced by different astringent compounds. In general, the glycolysation of the phenolic compound results in more velvety and smooth mouthdrying astringency. Flavonol glycosides and other flavonoid compounds and ellagitannins contribute to this velvety mouthdrying astringency. Additionally, they often lack the bitter properties. Proanthocyanidins and phenolic acids elicit more puckering and roughing astringency with some additional bitter properties. Quercetin 3‐O‐rutinoside, along with other quercetin glycosides, is among the key astringent compounds in black tea and red currants. In foods, there are always various other additional attributes that are perceived at the same with astringency. Astringent compounds themselves may have other sensory characteristics, such as bitter or sour properties, or they may enhance or suppress other sensory properties. Components contributing to these other properties, such as sugars, may also have similar effects on astringent sensations. Food components eliciting sweetness or fattiness or some polymeric polysaccharides can be used to mask astringent subqualities. Astringency can generally be referred to as a negative contributor to the liking of various foods. On the other hand, perceptions of astringent properties can vary among individuals. Many genetic factors that influence perceptions of taste properties, such as variations in perceiving a bitter taste or variations in saliva, may also effect the perception of astringency. Individuals who are more sensitive to different sensations may notice the differences between astringent properties more clearly. This may not have effects on the overall perception of astringency. However, in many cases, the liking of astringent foods may need to be learned by repetitive exposure. Astringency is often among the key sensory properties forming the unique overall flavour of certain foods, and therefore it also influences whether or not a food is liked. In many cases, astringency may be an important sub‐property suppressed by other more abundant sensory properties, but it may still have a significant contribution to the overall flavour and thus consumer preferences. The results of the practical work of this thesis show that the astringent phenolic compounds are mostly located in the skin fractions of black currants, crowberries and bilberries (publications I–III). The skin fractions themselves are rather tasteless. However, the astringent phenolic compounds can be efficiently removed from these skin fractions by consecutive ethanol extractions. Berries contain a wide range of different flavonol glycosides, hydroxycinnamic acid derivatives and anthocyanins and some of them strongly contribute to the different astringent and bitterness properties. Sweetness and sourness are located in the juice fractions along with the majority of sugars and fruit acids. The sweet and sour properties of the juice may be used to mask the astringent and bitterness properties of the extracts. Enzymatic treatments increase the astringent properties and fermented flavour of the black currant juice and decrease sweetness and freshness due to the effects on chemical compositions (IV). Sourness and sweetness are positive contributors to the liking of crowberry and bilberry fractions, whereas bitterness is more negative (V). Some astringent properties in berries are clearly negative factors, whereas some may be more positive. The liking of berries is strongly influenced by various consumer background factors, such as motives and health concerns. The liking of berries and berry fractions may also be affected by genetic factors, such as variations in the gene hTAS2R38, which codes bitter taste receptors (V).

Added Value of Combining Value and Momentum Indicators in the Swiss Stock Market

The purpose of the thesis is to examine the added value of combining value and momentum indicators in the Swiss stock exchange. Value indicators employed are P/E, EV/EBITDA, P/CF, P/B ja P/S. Momentum indicators examined are 52-week high, acceleration rate, 12-month past return and 6-month past return. The thesis examines whether the composite value measures based on the above mentioned ratios can add value and whether the inclusion of momentum can further improve the risk return profile of the value portfolios. The data is gathered from the Swiss equity market during the sample period from May 2001 to May 2011. Previous studies have shown that composite value measures can somewhat add value to the value portfolio strategy. Similarly, recent academic literature have found evidence that momentum works well as a timing indicator for time to entry to value stocks. This study indicates that the added value of composite value measures exists. It also shows that momentum combined to acceleration rate can significantly improve the risk adjusted performance of value-only portfolios.

DETERMINACIÓN DE MEDIOS DE CULTIVO Y PH PARA LA MASIFICACIÓN in vitro DE CEPAS DE Suillus luteus Aubl. ASOCIADAS A Pinus radiata D. Don Y Scleroderma citrinum Pers. ASOCIADAS A Eucalyptus globulus Labill. DE LA REGIÓN DEL BIOBÍO, CHILE

El uso de agentes biológicos en la producción en vivero ha aflorado como un elemento que permite no sólo mejorar la calidad morfológica y fisiológica de las plantas, sino que también posibilitar un mayor éxito en el ámbito silvicultural de una plantación. Estos agentes biológicos requieren de un ambiente óptimo para crecer, asociarse y reproducirse. El objetivo de este estudio fue determinar la dependencia del pH y el medio de cultivo en el crecimiento in vitro de distintas cepas de Suillus luteus y Scleroderma citrinum asociadas a Pinus radiata y Eucalyptus globulus, respectivamente. El estudio se realizó en condiciones controladas de temperatura y humedad, disponiendo los inóculos en placas Petri con diferentes medios cultivo, evaluando parámetros de crecimiento y biomasa a los 38 días para S. luteus y 105 días para S. citrinum. Los resultados indican que tanto el medio de cultivo, el pH del medio, así como las cepas de cada especie estudiada, son determinantes en las respuestas de crecimiento de los hongos ectomicorrícicos in vitro evaluados. Las cepas de S. luteus se desarrollaron adecuadamente en un medio de cultivo con abundancia de nutrientes (BAF, MMN) como en baja presencia de ellos (EMA), y con pH más bien ácido (4,8 y 5,8). Por otro lado, las cepas de S. citrinum presentaron, para los mismos ambientes, un desarrollo inferior y lento, no obstante, la cepa Sc8 se reprodujo de forma óptima y rápida bajo un medio de cultivo BAF y con un pH moderadamente ácido de 5,8.

Teor de fósforo e pH no bulbo molhado, com diferentes freqüências de fertirrigação, utilizando ácido fosfórico

A aplicação de fertilizantes fosfatados, tais como superfosfofato simples, superfosfofato triplo e monofosfato de amônio, via gotejamento, pode apresentar incrustações nas canalizações e obstruções de emissores. No presente trabalho, realizado na UNESP/Jaboticabal - SP, estudaram-se a distribuição do fósforo e a sua influência sobre o pH e a umidade em Latossolo Vermelho, fertirrigado durante um mês, com cinco aplicações semanais de ácido fosfórico. Utilizaram-se quatro repetições e oito tratamentos, constituídos da combinação de doses de P2O5 (0 e 50 kg ha-1) e freqüências de aplicação de 1; 3; 5 e 7 dias. Pelos resultados obtidos, observou-se que a freqüência de irrigação ou de fertirrigação não influenciou na distribuição final da umidade no bulbo molhado; aplicando-se o ácido fosfórico, o pH do solo até 30 cm do gotejador e até 40 cm em profundidade foi reduzido, atingindo valor de 3,6, e o teor de fósforo foi maior nessa mesma porção do bulbo, ultrapassando 1.500 mg dm-3. Isso permite indicar que o ácido fosfórico pode ser utilizado em irrigação localizada, com controle do pH do solo, pois sua redução influencia no desenvolvimento das culturas e, conseqüentemente, na produtividade.

Efeito da concentração de coagulantes e do pH da solução na turbidez da água, em recirculação, utilizada no processamento dos frutos do cafeeiro

Com o objetivo de determinar a dose e a faixa de pH dos coagulantes sulfato de alumínio (SA), sulfato ferroso clorado (SFC), cloreto férrico (CF) e extrato de semente de moringa (ESM), que proporcionassem maior eficiência na remoção da turbidez na água residuária da despolpa de frutos do cafeeiro (ARDC), após serem efetuadas cinco recirculações, foram conduzidos ensaios de coagulação/floculação utilizando o aparelho "Jar-test". Todos esses coagulantes foram avaliados nas concentrações de 0; 0,5; 1,0; 1,5; 2,0; 2,5 e 3,0 g L-1. No caso da solução preparada com ESM, as doses utilizadas foram: 0; 10; 20; 30; 40; 50 e 60 mL L-1. O pH da solução em teste foi alterado, utilizando-se do hidróxido de sódio (NaOH), na concentração de 0,3 mol L-1, sendo avaliadas as faixas de 4,0 a 5,0; 5,0 a 6,0; 6,0 a 7,0 e 7,0 a 8,0. No ensaio de coagulação/floculação, o ESM proporcionou maior remoção de SS (sólidos em suspensão) da ARDC com a dose de 10 mL L-1 e pH de 4,27 (natural). Para os coagulantes SA e CF, os melhores resultados foram obtidos com a concentração de 3 g L-1 e pH de 7,27 e, para o coagulante SFC, com a concentração de 3 g L-1 e pH de 4,27.

Material embodiment and energy flows as efficiency indicators of soybean (Glycine max) production in Brazil

As the requirement for agriculture to be environmentally suitable there is a necessity to adopt indicators and methodologies approaching sustainability. In Brazil, biodiesel addition into diesel is mandatory and soybean oil is its main source. The material embodiment determines the convergence of inputs into the crop. Moreover, the material flows are necessary for any environmental analysis. This study evaluated distinct production scenarios, and also conventional versus GMO crops, through the material embodiment and energy analysis. GMO crops demanded less indirectly applied inputs. The energy balance showed linearity with yield, whereas for EROI, the increases in input and yield were not affected.

Setting efficiency indicators for center pivots

In this study, it was discussed the efficiency criteria in each of the elements that compose a central pivot, and this analysis was applied to two sets of systems located in regions of Cruz Alta and Santo Augusto, state of Rio Grande do Sul, Brazil. The methodology used combines water and energy assessment through an indicator called Normalized Specific Consumption in Irrigation (C ENI), allowing thus a comparison between equipment and projects. The C ENI in Cruz Alta region showed 72% of the equipment above the standard (8.68 kWh mm-1 ha-1 100m-1), and in Santo Augusto region 64.28% with consumption above the standard. The mean irrigation efficiency for Cruz Alta region was 29.85%, with standard deviation of 5.41%, and for Santo Augusto region, it was 29.02%, with standard deviation of 5.15%.

Physical, chemical and microbiological properties of a Dystrophic Yellow Latosol using manipueira

The study aimed to evaluate chemical, microbiological and hydro-physical changes of a Dystrophic Yellow Latosol, receiver of different levels of manipueira (cassava wastewater) application, in the cultivation of 'Terra Maranhão' banana. The experimental design was a randomized block with three replications in a factorial scheme 3 x 4, in which it was considered three soil depths and four levels of manipueira. It was evaluated the weighted mean diameter of the aggregate, the percentage of aggregation at different periods, soil density, particle density, porosity and soil saturated hydraulic conductivity, in addition to pH of P (mg dm -3), K (mg dm-3), Ca (cmolc dm-3), Mg (cmolc dm-3), Ca+Mg (cmolc dm-3), Al (cmolc dm-3), Na (cmolc dm -3), H+Al (cmolc dm-3), CEC (cmolc dm-3), V%, OM (g kg-1), soil microbial biomass (Ug Cg-1 dry soil), acid phosphatase (Ug PNP g-1 h-1). The use of manipueira influenced some physical characteristic of the soil, but it was not possible to specify the effect of increasing application dosage. Therefore, the application did not affect the biological indicators assessed in the soil or its pH. The use of manipueira as a fertilizer in the doses used in this study showed low increase of K, P, H+Al and Al in the soil and a good increase of Mg, Ca and Ca+Mg, Na, CEC and V%.

Technical and economic indicators of the yellow passion fruit tree irrigated with underground water supply

The research aimed to quantify technical and economic indicators of yellow passion fruit tree irrigated with fractions of irrigation with underground source of water, to generate information that helps farmers in decision making on the implementation of investment in irrigated fruit growing (yellow passion fruit). For this purpose, we used the passion fruit crop irrigated with Microjet type irrigation system, with conducting system in simple espaliers. The treatments consisted of five hours of application of the depth of water required by the crop with irrigation frequency of two days. The results showed that the highest yield (16660kg ha-1) was obtained with the fractionation of irrigation twice a day (50% to 7h and 50% to 21h30), which provided an increase in productivity of 54%, demonstrating the financial viability and being highly profitable to the interest rate of 2% per year, with low sensitivity of financial risk to real interest rates above the prevailing market.

Cassava starch extraction effluent treatment in a one phase tubular horizontal pilot reactor with support medium

The cassava starch industries generate a large volume of wastewater effluent that, stabilized in ponds, wastes its biogas energy and pollutes the atmosphere. To contribute with the reversion of this reality, this manipueira treatment research was developed in one phase anaerobic horizontal pilot reactor with support medium in bamboo pieces. The reactor was excavated into the ground and sealed with geomembrane in HDPE, having a volume equal to 33.6 m³ and continuous feeding by gravity. The stability indicators were pH, volatile acidity/total alkalinity ratio and biogas production. The statistical analyses were performed by a completely randomized design, with answers submitted to multivariate analysis. The organical loads in COD were 0.556; 0.670; 0.678 and 0.770 g L-1 and in volatile solids (VS) of 0.659; 0.608; 0.570 and 0.761 g L-1 for the hydraulic retention times (HRT) of 13.0; 11.5; 10.0 and 7.0 days, respectively. The reductions in COD were 88; 80; 88 and 67% and for VS of 76; 77; 65 and 61%. The biogas productions relatively to the consumed COD were 0.368; 0.795; 0.891 and 0.907 Lg-1, for the consumed VS of 0.524; 0.930; 1.757 and 0.952 Lg-1 and volumetric of 0.131; 0.330; 0.430 and 0.374 L L-1 d-1. The reactor remained stable and the bamboo pieces, in visual examination at the end of the experiment, showed to be in good physical conditions.

Evaluation of thermorregulatory capacity of dairy buffaloes using infrared thermography

ABSTRACT The objective of this study was to evaluate the thermoregulatory response of dairy buffaloes in pre-milking and post-milking. To identify animal thermoregulatory capacity, skin surface temperatures were taken by an infrared thermometer (SST), a thermographic camera (MTBP) as well as respiratory rate records (RR). Black Globe and Humidity Index (BGHI), radiating thermal load (RTL) and enthalpy (H) were used to characterize the thermal environment. Artificial Neural Networks analyzed those indices as well as animal physiological data, using a single layer trained with the least mean square (LMS) algorithm. The results indicated that pre-milking and post-milking environments reached BGHI, RR, SST and MTBP values above thermal neutrality zone for buffaloes. In addition, limits of surface skin temperatures were mostly influenced by changing ambient conditions to the detriment of respiratory rates. It follows that buffaloes are sensitive to environmental changes and their skin temperatures are the best indicators of thermal comfort in relation to respiratory rate.

Climate driven changes in temperature, pH and food quality : effects on copepod reproduction

Increased emissions of greenhouse gases into the atmosphere are causing an anthropogenic climate change. The resulting global warming challenges the ability of organisms to adapt to the new temperature conditions. However, warming is not the only major threat. In marine environments, dissolution of carbon dioxide from the atmosphere causes a decrease in surface water pH, the so called ocean acidification. The temperature and acidification effects can interact, and create even larger problems for the marine flora and fauna than either of the effects would cause alone. I have used Baltic calanoid copepods (crustacean zooplankton) as my research object and studied their growth and stress responses using climate predictions projected for the next century. I have studied both direct temperature and pH effects on copepods, and indirect effects via their food: the changing phytoplankton spring bloom composition and toxic cyanobacterium. The main aims of my thesis were: 1) to find out how warming and acidification combined with a toxic cyanobacterium affect copepod reproductive success (egg production, egg viability, egg hatching success, offspring development) and oxidative balance (antioxidant capacity, oxidative damage), and 2) to reveal the possible food quality effects of spring phytoplankton bloom composition dominated by diatoms or dinoflagellates on reproducing copepods (egg production, egg hatching, RNA:DNA ratio). The two copepod genera used, Acartia sp. and Eurytemora affinis are the dominating mesozooplankton taxa (0.2 – 2 mm) in my study area the Gulf of Finland. The 20°C temperature seems to be within the tolerance limits of Acartia spp., because copepods can adapt to the temperature phenotypically by adjusting their body size. Copepods are also able to tolerate a pH decrease of 0.4 from present values, but the combination of warm water and decreased pH causes problems for them. In my studies, the copepod oxidative balance was negatively influenced by the interaction of these two environmental factors, and egg and nauplii production were lower at 20°C and lower pH, than at 20°C and ambient pH. However, presence of toxic cyanobacterium Nodularia spumigena improved the copepod oxidative balance and helped to resist the environmental stress, in question. In addition, adaptive maternal effects seem to be an important adaptation mechanism in a changing environment, but it depends on the condition of the female copepod and her diet how much she can invest in her offspring. I did not find systematic food quality difference between diatoms and dinoflagellates. There are both good and bad diatom and dinoflagellate species. Instead, the dominating species in the phytoplankton bloom composition has a central role in determining the food quality, although copepods aim at obtaining as a balanced diet as possible by foraging on several species. If the dominating species is of poor quality it can cause stress when ingested, or lead to non-optimal foraging if rejected. My thesis demonstrates that climate change induced water temperature and pH changes can cause problems to Baltic Sea copepod communities. However, their resilience depends substantially on their diet, and therefore the response of phytoplankton to the environmental changes. As copepods are an important link in pelagic food webs, their future success can have far reaching consequences, for example on fish stocks.