Optoelectronic properties of CuPc thin films deposited at different substrate temperatures

Structural and optical characterization of copper phthalocyanine thin film thermally deposited at different substrate temperatures was the aim of this work. The morphology of the films shows strong dependence on temperature, as can be observed by atomic force microscopy and x-ray diffraction spectroscopy, specifically in the grain size and features of the grains. The increase in the crystal phase with substrate temperature is shown by x-ray diffractometry. Optical absorption coefficient measured by photothermal deflection spectroscopy and optical transmittance reveal a weak dependence on the substrate temperature. Besides, the electro-optical response measured by the external quantum efficiency of Schottky ITO/CuPc/Al diodes shows an optimized response for samples deposited at a substrate temperature of 60 °C, in correspondence to the I-V diode characteristics.

Dynamics of F=1 87Rb condensates at finite temperatures

We investigate the dynamics of a F=1 spinor Bose-Einstein condensate of 87Rb atoms confined in a quasi-one-dimensional trap both at zero and at finite temperature. At zero temperature, we observe coherent oscillations between populations of the various spin components and the formation of multiple domains in the condensate. We study also finite temperature effects in the spin dynamics taking into account the phase fluctuations in the Bogoliubov-de Gennes framework. At finite T, despite complex multidomain formation in the condensate, population equipartition occurs. The length scale of these spin domains seems to be determined intrinsically by nonlinear interactions.

Development of Sclerotium rolfsii sclerotia on soybean, corn, and wheat straw, under different soil temperatures and moisture contents

The objective of this work was to evaluate the effect of moisture and temperature on the development of Sclerotium rolfsii on soybean, corn, and wheat straw. Wheat straw produced the lowest number of sclerotia. Intermediate soil moisture level (70% of field capacity), and temperatures ranging between 25-30ºC favored sclerotia development. No sclerotia were formed at temperatures between 30-35ºC, on any type of straw.

Caracterització del comportament reològic del suc de taronja concentrat a baixes temperatures. Efecte del procés de clarificació

Els sucs de taronja són els de major demanda dins el mercat espanyol i en la majoria de mercats a nivell mundial. Generalment, aquests sucs es comercialitzen amb polpa en suspensió i amb un contingut en sòlids solubles al voltant de 10-12ºBrix. No obstant, per a facilitar el transport i conservació durant l’emmagatzematge, s’obtenen concentrats en forma industrial, i posteriorment es dilueixen afegint aigua fins a la concentració requerida. Les indústries també obtenen sucs clarificats i concentrats que serveixen, entre d’altres, per a preparar mescles. Els sucs concentrats s’obtenen per extracció o premsat del suc i posterior clarificació i concentració mitjançant una etapa d’evaporació, assolint-se finalment productes al voltant dels 65ºBrix. En el procés d’elaboració el suc canvia contínuament de contingut en sòlids solubles i és sotmès a diverses temperatures, motius pels quals variaran les seves propietats, que depenen en gran mesura d’aquests dos paràmetres. Aquest treball d’investigació descrit fins ara, es complementarà amb l’estudi de les alternatives de tecnologia i enginyeria disponibles en la fabricació del suc de taronja concentrat. Aquesta tasca servirà per aprofundir en el coneixement tant del producte objecte de l’estudi com de la seva producció, a més a més d’aplicar sobre un cas concret els coneixements adquirits al llarg dels cinc anys de formació en el camp de l’enginyeria alimentària.

Conservation of Campomanesia adamantium (CAMB.) O. berg seeds in different packaging and at varied temperatures

This article aims at evaluating the effects of different packaging and varied storage temperatures on the germination potential of seeds of Campomanesia adamantium Camb. O. Berg. The seeds were packaged in glass, aluminum foil and plastic containers, or maintained inside intact fruits at 5, 10 and 15 ºC during 0, 7, 14 and 21 days. After these periods the seeds were sown in Germitest® germination paper and maintained in incubation chambers at 25 ºC under constant white light for 42 days. Seed moisture contents were evaluated both before and after storage, as well as germination percentages, germination speed index, root and aerial portion of seedlings lengths, and total dry weights. All possible combinations of packing materials, temperatures and storage times were tested, with four repetitions of 25 seeds for each treatment. C. adamantium seeds showed initial water contents of 31.5%. Glass and aluminum packaging were efficient at maintaining the water content of the seeds, and provided greater germination speed index than the other packaging materials. Germination percentages, seedlings lengths and dry weights did not vary among the different temperatures tested. C. adamantium seeds can be stored for up to 21 days at temperatures between 5 and 15 ºC without altering their physiological quality. In terms of cost-benefit efficiencies, these seeds can be stored without significant damage for 21 days while still inside the fruits at temperatures of 5, 10 or 15 ºC.

Evaluation of winter temperatures on apple budbreak using grafted twigs

Temperature is the main climate factor related to induction, maintenance and dormancy release in apple (Malus domestica Borkh.). The inadequate chilling exposure in apples causes budbreak problems, resulting in decrease in yield potential. Thus, the knowledge of physiological principles and environmental factors determining the dormancy phenomenon, especially winter temperature effects, it is necessary for the efficient selection of cultivars in a productive region. In addition, it is indispensable to adapt the orchard management aiming to decrease the problems caused by lack chilling during winter. The objective of this study was to evaluate the influence of different thermal conditions during the dormancy period on budbreak of apple cultivars. One-year-old twigs of 'Castel Gala' and 'Royal Gala' cultivars, grafted on M7 rootstock, were submitted to temperatures of 5, 10 and 15ºC for different exposure periods (168; 336; 672; 1,008 and 1,344 hours). After treatments execution, the plants were kept in a greenhouse at 25ºC. Budbreak was quantified when accumulated 3,444; 6,888; 10,332; 13,776; 17,220 and 20,664 GDHºC after temperature treatments. The cultivars responded differently to temperature effect during the winter period. The temperature of 15ºC during winter shows a greater effectiveness on 'Castel Gala' apple budbreak while in the 'Royal Gala' apples the temperatures of 5 and 10ºC show better performance. 'Castel Gala' cultivar (low chilling requirement) may supply its physiological necessities, may be capable to budburst, even when subjected to higher temperatures in relation to 'Royal Gala' apples (high chilling requirement).

Increased diversity of egg-associated bacteria on brown trout (Salmo trutta) at elevated temperatures.

The taxonomic composition of egg-associated microbial communities can play a crucial role in the development of fish embryos. In response, hosts increasingly influence the composition of their associated microbial communities during embryogenesis, as concluded from recent field studies and laboratory experiments. However, little is known about the taxonomic composition and the diversity of egg-associated microbial communities within ecosystems; e.g., river networks. We sampled late embryonic stages of naturally spawned brown trout at nine locations within two different river networks and applied 16S rRNA pyrosequencing to describe their bacterial communities. We found no evidence for a significant isolation-by-distance effect on the composition of bacterial communities, and no association between neutral genetic divergence of fish host (based on 11 microsatellites) and phylogenetic distances of the composition of their associated bacterial communities. We characterized core bacterial communities on brown trout eggs and compared them to corresponding water samples with regard to bacterial composition and its presumptive function. Bacterial diversity was positively correlated with water temperature at the spawning locations. We discuss this finding in the context of the increased water temperatures that have been recorded during the last 25 years in the study area.

Factors influencing zooplankton size structure at contrasting temperatures in coastal shallow lakes: Implications for effects of climate change

We assessed the importance of temperature, salinity, and predation for the size structure of zooplankton and provided insight into the future ecological structure and function of shallow lakes in a warmer climate. Artificial plants were introduced in eight comparable coastal shallow brackish lakes located at two contrasting temperatures: cold-temperate and Mediterranean climate region. Zooplankton, fish, and macroinvertebrates were sampled within the plants and at open-water habitats. The fish communities of these brackish lakes were characterized by small-sized individuals, highly associated with submerged plants. Overall, higher densities of small planktivorous fish were recorded in the Mediterranean compared to the cold-temperate region, likely reflecting temperature-related differences as have been observed in freshwater lakes. Our results suggest that fish predation is the major control of zooplankton size structure in brackish lakes, since fish density was related to a decrease in mean body size and density of zooplankton and this was reflected in a unimodal shaped biomass-sizespectrum with dominance of small sizes and low size diversity. Salinity might play a more indirect role by shaping zooplankton communities toward more salt-tolerant species. In a global-warming perspective, these results suggest that changes in the trophic structure of shallow lakes in temperate regions might be expected as a result of the warmer temperatures and the potentially associated increases in salinity. The decrease in the density of largebodied zooplankton might reduce the grazing on phytoplankton and thus the chances of maintaining the clear water state in these ecosystems

Sistema d'adquisició de temperatures de 2 canals via R.F.

Poder mesurar i enregistrar diferents tipus de magnituds com pressió, força, temperatura etc. s’ha convertit en una necessitat per moltes aplicacions actuals. Aquestes magnituds poden tenir procedències molt diverses, tals com l’entorn, o poden ser generades per sistemes mecànics, elèctrics, etc. Per tal de poder adquirir aquestes magnituds, s’utilitzen els sistemes d’adquisició de dades. Aquests sistemes, prenen mostres analògiques del món real, i les transformen en dades digitals que poden ser manipulades per un sistema electrònic. Pràcticament qualsevol magnitud es pot mesurar utilitzant el sensor adient. Una magnitud molt utilitzada en sistemes d’adquisició de dades, és la temperatura. Els sistemes d’adquisició de temperatures estan molt generalitzats, i podem trobar-los com a sistemes, on l’objectiu és mostrar les dades adquirides, o podem trobar-los formant part de sistemes de control, aportant uns inputs necessaris per el seu correcte funcionament, garantir-ne l’estabilitat, seguretat etc. Aquest projecte, promogut per l’empresa Elausa, s’encarregarà d’adquirir, el senyal d’entrada de 2 Termoparells. Aquests mesuraran temperatures de circuits electrònics, que es trobaran dintre la càmera climàtica de Elausa, sotmesos a diferents condicions de temperatura, per tal de rebre l’homologació del circuit. El sistema haurà de poder mostrar les dades adquirides en temps real, i emmagatzemar-les en un PC que estarà ubicat en una oficina, situada a uns 30 m de distància de la sala on es farà el test. El sistema constarà d’un circuit electrònic que adquirirà, i condicionarà el senyal de sortida dels termoparells, per adaptar-lo a la tensió d’entrada d’un convertidor analògic digital, del microcontrolador integrat en aquesta placa. Seguidament aquesta informació, s’enviarà a través d’un mòdul transmissor de radiofreqüència, cap al PC on es visualitzaran les dades adquirides. Els objectius plantejats són els següents: - Dissenyar el circuit electrònic d’adquisició i condicionament del senyal. - Dissenyar, fabricar i muntar el circuit imprès de la placa d’adquisició. - Realitzar el programa de control del microcontrolador. - Realitzar el programa per presentar i desar les dades en un PC. - El sistema ha d’adquirir 2 temperatures, a través de Termoparells amb un rang d’entrada de -40ºC a +240ºC - S’ha de transmetre les dades via R.F. Els resultats del projecte han estat satisfactoris i s’han complert els objectius plantejats.

Germination and vigor of Dimorphandra mollis benth. seeds under different temperatures and substrates

The Dimorphandra mollis Benth. - Caesalpiniaceae is a native forest species coming from the Cerrado and Caatinga due to its economical and ecological use, which justifies the studies on seed germination. In this work, germinative performance of D. mollis seeds were studied in different conditions of temperature regime and substrate. The experimental delineation used was completely randomized in factorial 4 x 4 (4 substrates -sand, coconut fiber, vermiculite and paper towel; and 4 temperatures: 25, 30, 35 and 20-30ºC), with four replications of 25 seeds each. The following parameters were evaluated: seed moisture content, final germination, first germination count, germination speed index, length and dry matter weight. The best germination and vigor is obtained at 30 and 35ºC. The substrates paper towel and vermiculite allow satisfactory germinative performance of seeds, being suitable to evaluate the physiological quality of D. mollis seeds.

Mechanical properties of castor beans subject to different drying temperatures aiming to disrupt the bean coat

In castor oil extraction process, the bean coat is abrasive to the equipment and releases substances that modify the oil color, reducing its quality. A potential solution would be to run the extraction by compressing only the endosperm. Due to lack of information, the objective of this study was to evaluate the influence of forced air drying at 40, 60, 80 and 100 ºC and farmyard drying, in the mechanical properties of the beans, aiming to break the bean coat. Castor beans were subjected to compression tests, in two perpendicular directions, at a strain rate of 0.6 mm.s-1. Average values of force, deformation energy, strain, all at rupture, and stiffness were used to evaluate the effects of dehydration. It was observed that the heat treatments did not alter the mechanical properties of castor beans, the strain and stiffness values discriminate the differences between the directions and had the lowest coefficients of variation. It was concluded that forced air drying, more costly than farmyard drying, does not bring benefits to the decortication. However, regardless the heat treatment used, the mechanical stress lengthwise is the most suitable to promote decortication.

Influence of the bipartite scrotum on the testicular and scrotal temperatures in goats

The influence of the scrotal bipartition and of the year period on the scrotal-testicular thermal regulation was evaluated in male goats raised in Piaui State, Brazil. Eighteen male goats at mating age were accomplished in this study and arranged into three Groups (6 animals each) obeying the classification as goats presenting no scrotal bipartition (Group I), goats showing scrotal bipartition at 50% of the testicular length (Group II), and goats with more than 50% of scrotal bipartition (Group III). The scrotal, testicular and spermatic funiculi temperatures were evaluated invasively with the aid of a digital thermometer and non-invasive with a pyrometer in the proximal, medial and distal portion. The data were acquired during the dry (October-November) and rainy (February-March) period of the year, measured in two shifts: morning (6h00-7h00) and afternoon (14h00-15h00). The results were submitted to variance analysis (ANOVA) following the SNK test for average comparison (p<0.05). The year period interfered on the scrotal-testicular thermal regulation, due to increased temperatures of the scrotal, testicular and spermatic funiculi during the dry period in comparison with the rainy period. The bipartition level was also a factor which contributed to the influence of scrotal-testicular temperature regulation, due to lower average scrotal-testicular temperature rates observed during both periods in the goats with higher levels of scrotal bipartition (>50%). It is possible to conclude that with the experimental conditions applied on this study, the level of scrotal bipartition and the climatic conditions interfere with the scrotal-testicular thermal regulation in goats.

Ultimate capacity of stainless steel rectangular hollow section X- joints at low temperatures

Growing demand for stainless steel construction materials has increased the popularity of substitutive materials for austenitic stainless steels. The lean duplex grades have taken their place in building of structures exposed to corrosive environments. Since the duplex grades are relatively new materials, the current codes and norms do not fully cover the newest duplex grades. The joints tested in this thesis were designed and studied according to Eurocode 3, even though all the materials are not yet accepted to the standards. The main objective in this thesis was to determine the differences of the used materials in behaviour under loading at low temperatures. Tests in which the deformation and strength properties of the joints were determined were done at the temperature of -46°C, which is the requirement of temperature for structures designed according to Norsok standards. Results show that replacing the austenitic grade with the lean duplex grade is acceptable.